WO2012081385A1 - Method for producing polyester film, polyester film for solar cell, and solar cell electric power generation module - Google Patents

Method for producing polyester film, polyester film for solar cell, and solar cell electric power generation module Download PDF

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Publication number
WO2012081385A1
WO2012081385A1 PCT/JP2011/077401 JP2011077401W WO2012081385A1 WO 2012081385 A1 WO2012081385 A1 WO 2012081385A1 JP 2011077401 W JP2011077401 W JP 2011077401W WO 2012081385 A1 WO2012081385 A1 WO 2012081385A1
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polyester
polyester film
amount
solar cell
film
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PCT/JP2011/077401
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French (fr)
Japanese (ja)
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竜太 竹上
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富士フイルム株式会社
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Priority to CN201180059659.9A priority Critical patent/CN103260847B/en
Publication of WO2012081385A1 publication Critical patent/WO2012081385A1/en

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    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G63/00—Macromolecular compounds obtained by reactions forming a carboxylic ester link in the main chain of the macromolecule
    • C08G63/78—Preparation processes
    • C08G63/80—Solid-state polycondensation
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
    • B29C48/001—Combinations of extrusion moulding with other shaping operations
    • B29C48/0018—Combinations of extrusion moulding with other shaping operations combined with shaping by orienting, stretching or shrinking, e.g. film blowing
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
    • B29C48/03—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor characterised by the shape of the extruded material at extrusion
    • B29C48/07—Flat, e.g. panels
    • B29C48/08—Flat, e.g. panels flexible, e.g. films
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
    • B29C48/25—Component parts, details or accessories; Auxiliary operations
    • B29C48/88—Thermal treatment of the stream of extruded material, e.g. cooling
    • B29C48/91—Heating, e.g. for cross linking
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
    • B29C48/25—Component parts, details or accessories; Auxiliary operations
    • B29C48/88—Thermal treatment of the stream of extruded material, e.g. cooling
    • B29C48/911—Cooling
    • B29C48/9135—Cooling of flat articles, e.g. using specially adapted supporting means
    • B29C48/914—Cooling of flat articles, e.g. using specially adapted supporting means cooling drums
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
    • B29C48/25—Component parts, details or accessories; Auxiliary operations
    • B29C48/88—Thermal treatment of the stream of extruded material, e.g. cooling
    • B29C48/911—Cooling
    • B29C48/9135—Cooling of flat articles, e.g. using specially adapted supporting means
    • B29C48/915—Cooling of flat articles, e.g. using specially adapted supporting means with means for improving the adhesion to the supporting means
    • B29C48/9165—Electrostatic pinning
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
    • B29C48/25—Component parts, details or accessories; Auxiliary operations
    • B29C48/88—Thermal treatment of the stream of extruded material, e.g. cooling
    • B29C48/911—Cooling
    • B29C48/9135—Cooling of flat articles, e.g. using specially adapted supporting means
    • B29C48/915—Cooling of flat articles, e.g. using specially adapted supporting means with means for improving the adhesion to the supporting means
    • B29C48/917—Cooling of flat articles, e.g. using specially adapted supporting means with means for improving the adhesion to the supporting means by applying pressurised gas to the surface of the flat article
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
    • B29C48/25—Component parts, details or accessories; Auxiliary operations
    • B29C48/92—Measuring, controlling or regulating
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L31/04—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof adapted as photovoltaic [PV] conversion devices
    • H01L31/042—PV modules or arrays of single PV cells
    • H01L31/048—Encapsulation of modules
    • H01L31/0481—Encapsulation of modules characterised by the composition of the encapsulation material
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C2948/00—Indexing scheme relating to extrusion moulding
    • B29C2948/92—Measuring, controlling or regulating
    • B29C2948/92009—Measured parameter
    • B29C2948/92219—Degree of crosslinking, solidification, crystallinity or homogeneity
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C2948/00—Indexing scheme relating to extrusion moulding
    • B29C2948/92—Measuring, controlling or regulating
    • B29C2948/92504—Controlled parameter
    • B29C2948/92704—Temperature
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C2948/00—Indexing scheme relating to extrusion moulding
    • B29C2948/92—Measuring, controlling or regulating
    • B29C2948/92504—Controlled parameter
    • B29C2948/92723—Content, e.g. percentage of humidity, volatiles, contaminants or degassing
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
    • B29C48/25—Component parts, details or accessories; Auxiliary operations
    • B29C48/36—Means for plasticising or homogenising the moulding material or forcing it through the nozzle or die
    • B29C48/375—Plasticisers, homogenisers or feeders comprising two or more stages
    • B29C48/385—Plasticisers, homogenisers or feeders comprising two or more stages using two or more serially arranged screws in separate barrels
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
    • B29C48/25—Component parts, details or accessories; Auxiliary operations
    • B29C48/36—Means for plasticising or homogenising the moulding material or forcing it through the nozzle or die
    • B29C48/375—Plasticisers, homogenisers or feeders comprising two or more stages
    • B29C48/387—Plasticisers, homogenisers or feeders comprising two or more stages using a screw extruder and a gear pump
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00—Energy generation through renewable energy sources
    • Y02E10/50—Photovoltaic [PV] energy

Definitions

  • the present invention relates to a method for producing a polyester film, a polyester film for solar cells, and a solar cell power generation module.
  • the solar cell power generation module used for this solar power generation has a structure in which (sealant) / solar cell element / sealant / back sheet is laminated in this order on glass on which sunlight is incident. is there.
  • Resin materials such as polyester have been used for the back surface protective film (so-called back sheet) disposed on the side opposite to the sunlight incident side of the solar cell power generation module.
  • Polyesters such as polyethylene terephthalate (PET) usually have a large amount of carboxyl groups and hydroxyl groups on the surface thereof, are prone to hydrolysis in an environment where moisture exists, and tend to deteriorate over time.
  • polyesters used in solar cell power generation modules and the like that are constantly exposed to wind and rain such as outdoors are required to have particularly low hydrolyzability. Further, same applies to the polyester to be applied to outdoor applications other than the solar cell power generation module applications, it is required to hydrolyzable is suppressed.
  • the amount of terminal COOH of the polyester that is, the concentration of terminal COOH, can be evaluated by an acid value (AV; Acid Value). If a polyester having a small acid value is polymerized and applied to a film, a film having hydrolysis resistance can be produced.
  • AV Acid Value
  • polyester film for sealing a back surface of a solar cell which contains a titanium compound and a phosphorus compound in amounts satisfying two predetermined relational expressions, and the terminal COOH concentration of the polyester is 40 equivalents / ton or less
  • environmental resistance such as hydrolysis resistance and weather resistance is improved (see, for example, JP-A-2007-204538).
  • solid phase polymerized polyester that undergoes solid phase polymerization under specific conditions in an inert gas atmosphere with an oxygen concentration of 300 ppm or less Is disclosed (for example, see Japanese Patent Application Laid-Open No. 2009-052041). Furthermore, a method of drying granular PET resin with a high-temperature gas for crystallization of the PET resin has been disclosed (for example, see JP-T-2001-519522). H. Zimmerman, N .; T.A. Kim, Polymer Eng. & Sci. , 20, 680 (1980) shows that the lower the amount of terminal carboxy groups, the faster the hydrolysis reaction rate decreases.
  • the present invention relates to a method for producing a polyester film that obtains a polyester film in which variation in hydrolysis resistance is suppressed as compared with a conventional method for producing a polyester film, and a polyester film for solar cells in which variation in hydrolysis resistance is suppressed. And it aims at providing the solar cell power generation module which can obtain the stable power generation performance over a long period of time, and makes it a subject to achieve the object.
  • a solid-phase polymerization step in which a polyester having a crystallinity distribution ⁇ of 3% ⁇ ⁇ 15% is supplied to a reaction vessel and solid-phase polymerized; An extrusion process for extruding the solid-phase polymerized polyester into a film; and It is a manufacturing method of the polyester film which has this.
  • ⁇ 2> The method for producing a polyester film according to ⁇ 1>, wherein the crystallinity distribution ⁇ of the polyester is 5% ⁇ ⁇ ⁇ 13%.
  • the polyester is a method for producing a polyester film according to ⁇ 1> or ⁇ 2>, wherein the crystallite size distribution ⁇ D is 10% or less.
  • ⁇ 4> The method for producing a polyester film according to any one of ⁇ 1> to ⁇ 3>, wherein the polyester has a crystallite size distribution ⁇ D of 3% to 9%.
  • ⁇ 5> Any one of the above ⁇ 1> to ⁇ 4>, wherein a hot gas is supplied to the polyester before the solid phase polymerization step, and the polyester is heated and crystallized by the supplied hot gas. It is a manufacturing method of the polyester film as described in one.
  • ⁇ 6> supply amount of the thermal gas [Nm 3 / Kg] is, relative to the polyester 1 kg, is a method for producing a polyester film according to the a 0.1Nm 3 ⁇ 1.5Nm 3 ⁇ 5> .
  • ⁇ 7> The method for producing a polyester film according to any one of ⁇ 1> to ⁇ 6>, wherein the temperature of the polyester when entering the reaction vessel is 180 ° C. to 220 ° C.
  • ⁇ 8> The method for producing a polyester film according to any one of ⁇ 1> to ⁇ 7>, wherein the solid phase polymerization time is 5 hours to 100 hours.
  • ⁇ 9> The method for producing a polyester film according to any one of ⁇ 1> to ⁇ 8>, wherein the crystallite diameter D of the polyester before solid phase polymerization is 80 to 120 mm.
  • ⁇ 10> The method for producing a polyester film according to any one of ⁇ 1> to ⁇ 9>, wherein the crystallinity ⁇ of the polyester before the solid phase polymerization is 47% to 58%.
  • the solar cell polyester film according to ⁇ 11> which has a long shape and includes at least terminal COOH, and variation in the amount of the terminal COOH in the longitudinal direction is less than 2 eq / ton.
  • ADVANTAGE OF THE INVENTION compared with the manufacturing method of the conventional polyester film, the manufacturing method of the polyester film which obtains the polyester film in which the variation in hydrolysis resistance was suppressed can be provided. Also, ADVANTAGE OF THE INVENTION According to this invention, the polyester film for solar cells by which the variation in hydrolysis resistance was suppressed compared with the conventional polyester film can be provided. Furthermore, ADVANTAGE OF THE INVENTION According to this invention, the solar cell power generation module from which stable power generation performance is obtained over a long term can be provided.
  • polyester film production method of the present invention and the solar cell polyester film and solar cell power generation module using the same will be described in detail.
  • the method for producing a polyester film according to the present invention includes a solid phase polymerization step in which a polyester having a crystallinity distribution ⁇ of 3% ⁇ ⁇ 15% is supplied to a reaction vessel and subjected to solid phase polymerization, and the solid phase polymerization is performed. And an extrusion process for extruding polyester into a film.
  • the manufacturing method of the polyester film of this invention may have another process as needed, and may be comprised.
  • polyester has a terminal carboxy group (terminal COOH), the terminal carboxy group (terminal COOH) serves as a catalyst and is easily hydrolyzed.
  • the amount of terminal COOH contained in the polyester can be confirmed by the size of the terminal COOH amount (AV) of the polyester, and it can be said that the smaller the terminal COOH amount, the better the hydrolysis resistance.
  • the amount of terminal COOH of the polyester tends to increase when the polyester is heated and melted during extrusion molding or the like. This is considered to be because thermal decomposition occurs due to the polyester being overheated, and terminal COOH is generated. It is considered that polyester overheating is likely to occur due to fluctuations in pressure for extruding polyester in the extruder (pressure fluctuations).
  • the terminal COOH amount (acid value), crystallinity ⁇ , intrinsic viscosity (IV), moisture content, and the like of the polyester can be controlled.
  • the manufacturing method of the polyester film of this invention is demonstrated in detail.
  • Solid-state polymerization process In the solid phase polymerization step, a polyester having a crystallinity distribution ⁇ of 3% ⁇ ⁇ 15% is supplied to the reaction vessel and subjected to solid phase polymerization.
  • polyester First, polyester will be described.
  • the kind of polyester is not particularly limited. It may be synthesized using a dicarboxylic acid component and a diol component, or a commercially available polyester may be used.
  • the polyester when synthesized, for example, it can be obtained by subjecting (A) a dicarboxylic acid component and (B) a diol component to an esterification reaction and / or a transesterification reaction by a well-known method.
  • dicarboxylic acid component examples include malonic acid, succinic acid, glutaric acid, adipic acid, suberic acid, sebacic acid, dodecanedioic acid, dimer acid, eicosandioic acid, pimelic acid, azelaic acid, methylmalonic acid Aliphatic dicarboxylic acids such as ethylmalonic acid, adamantane dicarboxylic acid, norbornene dicarboxylic acid, isosorbide, cyclohexanedicarboxylic acid, decalin dicarboxylic acid, and the like, terephthalic acid, isophthalic acid, phthalic acid, 1,4- Naphthalene dicarboxylic acid, 1,5-naphthalene dicarboxylic acid, 2,6-naphthalene dicarboxylic acid, 1,8-naphthalene dicarboxylic acid, 4,4′-diphenyl dicarboxylic acid, 4,4
  • diol component examples include fats such as ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,2-butanediol, and 1,3-butanediol.
  • Diols cycloaliphatic dimethanol, spiroglycol, isosorbide and other alicyclic diols, bisphenol A, 1,3-benzenedimethanol, 1,4-benzenedimethanol, 9,9'-bis (4-hydroxyphenyl)
  • Diol compounds such as aromatic diols such as fluorene.
  • the dicarboxylic acid component contains an aromatic dicarboxylic acid as a main component.
  • the "main component” refers to the proportion of the aromatic dicarboxylic acid in the dicarboxylic acid component is 80% or more.
  • a dicarboxylic acid component other than the aromatic dicarboxylic acid may be included. Examples of such a dicarboxylic acid component include ester derivatives such as aromatic dicarboxylic acids.
  • at least one aliphatic diol is used as the (B) diol component.
  • the aliphatic diol can contain ethylene glycol, and preferably contains ethylene glycol as a main component.
  • the main component means that the proportion of ethylene glycol in the diol component is 80% or more.
  • the amount of the aliphatic diol (eg, ethylene glycol) used is in the range of 1.015 mol to 1.50 mol with respect to 1 mol of the aromatic dicarboxylic acid (eg, terephthalic acid) and, if necessary, its ester derivative. Is preferred.
  • the amount used is more preferably in the range of 1.02 mol to 1.30 mol, and still more preferably in the range of 1.025 mol to 1.10 mol.
  • the esterification reaction proceeds favorably, and if it is in the range of 1.50 mol or less, for example, by-production of diethylene glycol due to dimerization of ethylene glycol is suppressed, Many characteristics such as melting point, glass transition temperature, crystallinity, heat resistance, hydrolysis resistance, and weather resistance can be kept good.
  • a conventionally known reaction catalyst can be used for the esterification reaction and / or the transesterification reaction.
  • the reaction catalyst include alkali metal compounds, alkaline earth metal compounds, zinc compounds, lead compounds, manganese compounds, cobalt compounds, aluminum compounds, antimony compounds, titanium compounds, and phosphorus compounds.
  • an antimony compound, a germanium compound, or a titanium compound as a polymerization catalyst at an arbitrary stage before the polyester production method is completed.
  • a germanium compound is taken as an example, it is preferable to add the germanium compound powder as it is.
  • an aromatic dicarboxylic acid and an aliphatic diol are polymerized in the presence of a catalyst containing a titanium compound.
  • an organic chelate titanium complex having an organic acid as a ligand is used as a catalyst titanium compound, and at least an organic chelate titanium complex, a magnesium compound, and an aromatic ring as a substituent in the step.
  • a process of adding a pentavalent phosphate ester having no sulfite in this order is
  • an aromatic dicarboxylic acid and an aliphatic diol are mixed with a catalyst containing an organic chelate titanium complex, which is a titanium compound, prior to addition of a magnesium compound and a phosphorus compound.
  • Titanium compounds such as organic chelate titanium complexes have high catalytic activity for esterification reactions, so that esterification reactions can be performed satisfactorily.
  • the titanium compound may be added to the mixture of the dicarboxylic acid component and the diol component, or after mixing the dicarboxylic acid component (or diol component) and the titanium compound, the diol component (or dicarboxylic acid component) is mixed. May be. Further, the dicarboxylic acid component, the diol component, and the titanium compound may be mixed at the same time.
  • the mixing is not particularly limited, and can be performed by a conventionally known method.
  • PET polyethylene terephthalate
  • PEN polyethylene-2,6-naphthalate
  • PET has a germanium (Ge) compound (Ge-based catalyst), an antimony (Sb) compound (Sb-based catalyst), an aluminum (Al) compound (Al-based catalyst), and a titanium (Ti) compound (Ti-based catalyst) as catalyst components.
  • germanium (Ge) compound Ge-based catalyst
  • Sb antimony
  • Al aluminum
  • Ti titanium
  • titanium compounds excluding titanium oxide
  • the titanium compound has high reaction activity and can lower the polymerization temperature. Therefore, it is possible to suppress the polyester from being thermally decomposed during the polymerization reaction and generating COOH. That is, by using a titanium compound, the amount of terminal carboxylic acid of polyester that causes thermal decomposition can be reduced, and foreign matter formation can be suppressed. By reducing the amount of the terminal carboxylic acid of the polyester, it is possible to suppress thermal decomposition of the polyester film after the production of the polyester film. Of the titanium compounds, titanium oxide used as a whitening agent cannot provide such an effect.
  • the titanium compound used as the catalyst is preferably at least one of organic chelate titanium complexes having an organic acid as a ligand.
  • organic acid include citric acid, lactic acid, trimellitic acid, malic acid and the like.
  • an organic chelate complex having citric acid or citrate as a ligand is preferable.
  • the titanium-based catalyst also has a catalytic effect on the esterification reaction. By adding it at the esterification stage, the oligomer acid value at the end of the esterification reaction is lowered, and the subsequent polycondensation reaction is performed more efficiently.
  • complexes with citric acid as a ligand are more resistant to hydrolysis than titanium alkoxides, etc., and do not hydrolyze in the esterification reaction process, while maintaining the original activity and catalyzing esterification and polycondensation reactions. It is estimated to function effectively as In general, it is known that hydrolysis resistance deteriorates as the amount of terminal carboxyl groups increases, and the hydrolysis resistance is expected to be improved by decreasing the amount of terminal carboxyl groups by the above addition method. .
  • citrate chelate titanium complex for example, VERTEC® AC-420 manufactured by Johnson Matthey can be easily obtained as a commercial product.
  • the aromatic dicarboxylic acid and the aliphatic diol can be introduced by preparing a slurry containing them and continuously supplying it to the esterification reaction step.
  • titanium compounds In addition to the organic chelate titanium complex, titanium compounds generally include oxides, hydroxides, alkoxides, carboxylates, carbonates, oxalates, and halides. Other titanium compounds may be used in combination with the organic chelate titanium complex as long as the effects of the present invention are not impaired.
  • titanium compounds examples include tetra-n-propyl titanate, tetra-i-propyl titanate, tetra-n-butyl titanate, tetra-n-butyl titanate tetramer, tetra-t-butyl titanate, tetracyclohexyl titanate, Titanium alkoxide such as tetraphenyl titanate, tetrabenzyl titanate, titanium oxide obtained by hydrolysis of titanium alkoxide, titanium-silicon or zirconium composite oxide obtained by hydrolysis of a mixture of titanium alkoxide and silicon alkoxide or zirconium alkoxide, Titanium acetate, titanium oxalate, potassium potassium oxalate, sodium titanium oxalate, potassium titanate, sodium titanate, titanium titanate-aluminum hydroxide mixture, titanium chloride, titanium chloride Down - aluminum chloride mixture, and titanium acetylacetonate.
  • Titanium alkoxide such
  • the polyester When the polyester is polymerized, it is preferable to use a titanium compound (including a titanium-based catalyst) in a range of 1 ppm to 50 ppm, more preferably 2 ppm to 30 ppm, and still more preferably 3 ppm to 15 ppm in terms of titanium element.
  • the raw material polyester contains 1 ppm to 50 ppm of titanium element. If the amount of the titanium compound (including the titanium-based catalyst) contained in the raw material polyester is less than 1 ppm in terms of titanium element, the weight average molecular weight (Mw) of the polyester cannot be increased, and it is easy to thermally decompose. Foreign matter tends to increase in the machine, which is not preferable.
  • the amount of the titanium compound (including the titanium-based catalyst) contained in the raw material polyester exceeds 50 ppmm in terms of titanium element, the titanium compound (including the titanium-based catalyst) becomes a foreign substance, and uneven stretching occurs when the polyester sheet is stretched. Because it causes, it is not preferable.
  • an aromatic dicarboxylic acid and an aliphatic diol are polymerized in the presence of a catalyst containing a titanium compound, and at least one of the titanium compounds is an organic chelate titanium complex having an organic acid as a ligand.
  • An esterification reaction step including at least a step of adding an organic chelate titanium complex, a magnesium compound, and a pentavalent phosphate ester having no aromatic ring as a substituent in this order, and an ester formed in the esterification reaction step
  • a polycondensation step in which a polycondensation product is produced by a polycondensation reaction of the chemical reaction product, and is preferably produced by a polyester production method.
  • polyesters that have a color tone and transparency that are inferior to those of other polyesters and that have excellent heat resistance. Moreover, polyester which has high transparency and few yellowishness is obtained, without using color tone adjusting materials, such as a cobalt compound and a pigment
  • This polyester can be used for applications requiring high transparency (for example, optical film, industrial squirrel, etc.), and it is not necessary to use an expensive germanium-based catalyst, so that the cost can be greatly reduced.
  • the foreign material-prone catalyst caused by Sb catalyst systems are avoided, it is generated and quality defects reduce failure at the film formation process, it is possible to achieve even lower cost by yield ratio improvement.
  • esterification reaction a process of adding an organic chelate titanium complex which is a titanium compound and a magnesium compound and a pentavalent phosphorus compound as additives in this order is provided. At this time, the esterification reaction proceeds in the presence of the organic chelate titanium complex, and thereafter, the addition of the magnesium compound is started before the addition of the phosphorus compound.
  • pentavalent phosphorus compound at least one pentavalent phosphate having no aromatic ring as a substituent is used.
  • pentavalent phosphate having no aromatic ring as a substituent
  • phosphoric acid esters having a lower alkyl group having 2 or less carbon atoms as a substituent [(OR) 3 —P ⁇ O; R an alkyl group having 1 or 2 carbon atoms]
  • phosphoric acid Trimethyl and triethyl phosphate are particularly preferable.
  • the addition amount of the phosphorus compound is preferably an amount such that the P element conversion value is in the range of 50 ppm to 90 ppm, more preferably 60 ppm to 80 ppm, and still more preferably 60 ppm to 75 ppm.
  • magnesium compound By including a magnesium compound in the polyester, the electrostatic applicability of the polyester is improved. In this case, although it is easy to color, in this invention, coloring is suppressed and the outstanding color tone and heat resistance are obtained.
  • the magnesium compound include magnesium salts such as magnesium oxide, magnesium hydroxide, magnesium alkoxide, magnesium acetate, and magnesium carbonate. Among these, magnesium acetate is most preferable from the viewpoint of solubility in ethylene glycol.
  • the amount of magnesium compound added is preferably such that the Mg element conversion value is 50 ppm or more, more preferably in the range of 50 ppm to 100 ppm, in order to impart high electrostatic applicability.
  • the addition amount of the magnesium compound is preferably an amount in the range of 60 ppm to 90 ppm, more preferably an amount in the range of 70 ppm to 80 ppm, from the viewpoint of imparting electrostatic applicability.
  • the value Z calculated from the following formula (i) for the titanium compound as the catalyst component and the magnesium compound and phosphorus compound as the additive satisfies the following relational expression (ii).
  • the P content is the amount of phosphorus derived from the entire phosphorus compound including the pentavalent phosphate ester having no aromatic ring
  • the Ti content is the amount of titanium derived from the entire Ti compound including the organic chelate titanium complex. It is.
  • (I) Z 5 ⁇ (P content [ppm] / P atomic weight) ⁇ 2 ⁇ (Mg content [ppm] / Mg atomic weight) ⁇ 4 ⁇ (Ti content [ppm] / Ti atomic weight) (Ii) 0 ⁇ Z ⁇ 5.0
  • the formula (i) expresses the amount of phosphorus that can act on titanium by excluding the phosphorus content that acts on magnesium from the total amount of phosphorus that can be reacted.
  • the titanium compound, phosphorus compound, and magnesium compound which are inexpensive and easily available, are used for color tone and heat while having the reaction activity required for the reaction.
  • a polyester excellent in coloring resistance can be obtained.
  • a chelate titanium complex having 1 ppm to 30 ppm of citric acid or citrate as a ligand to the aromatic dicarboxylic acid and the aliphatic diol
  • 60 ppm to 90 ppm (more preferably 70 ppm to 80 ppm) of a weak acid magnesium salt is added, and after the addition, 50 ppm to 90 ppm (more preferably 60 ppm to 75 ppm) of the aromatic ring is replaced.
  • the aspect which adds the pentavalent phosphate which does not have as a group is mentioned.
  • the esterification reaction may be carried out using a multistage apparatus in which at least two reactors are connected in series under conditions where ethylene glycol is refluxed while removing water or alcohol produced by the reaction from the system. it can.
  • the esterification reaction described above may be performed in one stage or may be performed in multiple stages.
  • the esterification reaction temperature is preferably 230 ° C to 260 ° C, more preferably 240 ° C to 250 ° C.
  • the temperature of the esterification reaction in the first reaction tank is preferably 230 ° C. to 260 ° C., more preferably 240 ° C. to 250 ° C.
  • the pressure is 1.0 kg / cm 2. It is preferably ⁇ 5.0 kg / cm 2 , more preferably 2.0 kg / cm 2 to 3.0 kg / cm 2 .
  • the temperature of the esterification reaction in the second reaction tank is preferably 230 ° C. to 260 ° C., more preferably 245 ° C. to 255 ° C., and the pressure is 0.5 kg / cm 2 to 5.0 kg / cm 2 , more preferably 1 0.0 kg / cm 2 to 3.0 kg / cm 2 . Furthermore, when carrying out by dividing into three or more stages, it is preferable to set the conditions for the esterification reaction in the intermediate stage to the conditions between the first reaction tank and the final reaction tank.
  • a polycondensation product is produced by subjecting an esterification reaction product produced by the esterification reaction to a polycondensation reaction.
  • the polycondensation reaction may be performed in one stage or may be performed in multiple stages.
  • the esterification reaction product such as an oligomer generated by the esterification reaction is subsequently subjected to a polycondensation reaction.
  • This polycondensation reaction can be suitably performed by supplying it to a multistage polycondensation reaction tank.
  • the polycondensation reaction conditions in the case of performing in a three-stage reaction tank are as follows: the first reaction tank has a reaction temperature of 255 ° C. to 280 ° C., more preferably 265 ° C. to 275 ° C., and a pressure of 100 to 10 torr (13 3 ⁇ 10 ⁇ 3 MPa to 1.3 ⁇ 10 ⁇ 3 MPa), more preferably 50 to 20 torr (6.67 ⁇ 10 ⁇ 3 MPa to 2.67 ⁇ 10 ⁇ 3 MPa), and the second reaction The tank has a reaction temperature of 265 ° C. to 285 ° C., more preferably 270 ° C.
  • a 10 torr ⁇ 3 torr is (1.33 ⁇ 10 -3 MPa ⁇ 4.0 ⁇ 10 -4 MPa)
  • a third reaction vessel in the final reaction tank the reaction temperature is 270 ° C. ⁇ 290 , More preferably from 275 ° C. ⁇ 285 ° C.
  • the pressure is 10torr ⁇ 0.1torr (1.33 ⁇ 10 -3 MPa ⁇ 1.33 ⁇ 10 -5 MPa), more preferably 5torr ⁇ 0.5torr (6.
  • An aspect of 67 ⁇ 10 ⁇ 4 MPa to 6.67 ⁇ 10 ⁇ 5 MPa) is preferable.
  • Additives such as light stabilizers, antioxidants, UV absorbers, flame retardants, lubricants (fine particles), nucleating agents (crystallization agents), crystallization inhibitors, etc. to the polyester synthesized as described above May further be included.
  • Crystallinity distribution ⁇ can be calculated as follows. 1) 100 grains of polyester immediately before being supplied to the reaction tank are randomly taken out. 2) The specific gravity of each polyester taken out is measured by the density gradient method, and the crystallinity of each polyester is calculated by the following formula (a).
  • Crystallinity (%) ⁇ (d ⁇ dA) / (dC ⁇ dA) ⁇ ⁇ 100
  • dA is the density when the polyester is completely amorphous
  • dC is the density when the polyester is completely crystallized
  • d is the density of the polyester
  • the average value of the degree of crystallinity ⁇ calculated for the 100 polyesters taken out is calculated. Further, from the difference between the maximum value ⁇ max and the minimum value ⁇ min of the crystallinity ⁇ calculated for 100 polyester grains, a crystallinity distribution ⁇ , which is a variation in crystallinity, is obtained by the following equation (b).
  • the crystallization of the polyester can be performed by heating the polyester.
  • the heating method include bringing the polyester into contact with a metal or supplying a hot gas to the polyester to exchange heat.
  • the method of contacting the metal is a method in which polyester particles are administered to a heated screw-shaped metal plate and the polyester is heated by rotating the screw (torus disk method).
  • the polyester in the above heating method in which the polyester is brought into contact with the metal, friction may occur due to contact between the metal and the polyester or contact between the polyesters, and polyester dust may be generated.
  • the crystallinity ⁇ of the polyester falls within, for example, a range of 39% to 42% (crystallinity distribution ⁇ is 3%), and the distribution tends to be narrow.
  • polyesters having various crystallinities may be prepared by the torus disk method and mixed to prepare a polyester of 3% ⁇ ⁇ 15%.
  • the heating method in which the polyester is heated by the hot gas the temperature unevenness is likely to occur due to indirect heating, and it is easy to obtain a polyester having a wide crystallinity distribution ⁇ .
  • the crystallinity ⁇ of the ester is in the range of 33% to 44% (the crystallinity distribution ⁇ is 11%), and the distribution becomes wide.
  • FIG. 1 is a schematic cross-sectional view showing a configuration example of a crystallization apparatus for heating polyester.
  • FIG. 1 shows a crystallization apparatus 100.
  • the crystallization apparatus 100 has hot gas supply ports 4 and 6 and hot gas discharge ports 12 and 14 that can supply hot gas (for example, nitrogen gas) to the wall.
  • hot gas for example, nitrogen gas
  • FIG. 1 two hot gas supply ports are shown, but there may be only one or three or more.
  • the crystallization apparatus 100 has an opening 8 for feeding polyester at the upper part and an opening 10 for discharging heated polyester at the lower part.
  • a plurality of rods are attached to the inner wall surface of the crystallization apparatus 100. At least a part of the bar is installed above the hot gas supply port 6.
  • the rod is a triangular prism having a triangular cross section, and is attached so that the axial direction is substantially perpendicular to the direction of gravity. Adjacent bars are arranged with an interval sufficient to allow the polyester to pass through. The polyester introduced from the opening 8 at the top of the crystallization apparatus 100 is scattered by hitting the rod, and the hot gas supplied from the hot gas supply port easily hits the polyester.
  • polyester is easily heated because the contact with the hot gas is prolonged due to slowing down by hitting with a stick and falling apart.
  • polyester is preferably a pellet of such particulate (polyester particles).
  • the rod 2 is only one means for facilitating the supply of hot gas heat to the polyester. Therefore, in FIG. 1, the cross section is a triangular prism, but the cross-sectional shape may be a circle, a polygon such as a quadrangle, a hexagon, etc., a plate having a net like a sieve, or a slit like a grid You may use the board which has 2 layers in piles. For example, five slit plates having triangular prism slits may be used. At this time, it is preferable to adjust the position of the slit so that the lower triangular prism is located below the space between the upper triangular prisms so that the positions of the spaces between the triangular prisms do not overlap in adjacent plates.
  • a polyester crystallization apparatus using a hot gas can be obtained as a roof type dryer manufactured by Buehler, and the apparatus may be used to crystallize the polyester.
  • the polyester heated by the hot gas is returned to the upper part of the opening 8 at the upper part of the crystallization apparatus 100 by a circulation device (not shown), and is heated again by being charged again from the opening 8. After the heating in the crystallization apparatus 100 is completed, it is discharged from the opening 10 at the lower part of the crystallization apparatus 100.
  • a crystallinity distribution ⁇ of 3% ⁇ ⁇ 15% indicates that the crystallinity ⁇ of the polyester varies widely, and the crystallinity ⁇ of the polyester varies due to heating of the polyester. It is thought to mean that there is a variation in time. That is, it is considered that heating with warm gas is more difficult to heat uniformly than heating with metal contact.
  • the variation in crystallite diameter D (crystallite diameter distribution ⁇ D) of the polyester obtained by heating (crystallization) is preferably smaller, and ⁇ D is preferably 10% or less.
  • the crystallite diameter is the size (maximum diameter) of the minimum crystal unit constituting the crystal, and can generally be measured using an X-ray diffractometer.
  • the crystallite diameter D of the polyester is considered to be likely to vary due to variations in the heating temperature of the polyester. Therefore, it is preferable to keep the temperature of the hot gas constant.
  • the temperature of the thermal gas is preferably set to 175 ° C. ⁇ 215 ° C., and more preferably set to 185 °C ⁇ 205 °C.
  • the hot gas is preferably an inert gas, and examples thereof include nitrogen (N 2 ) gas, argon (Ar) gas, carbon dioxide (CO 2 ) gas, and the like.
  • the heating time for the polyester is preferably 3 hours to 10 hours, more preferably 3 hours to 8 hours. When it is 3 hours or more, the heating time varies, and the crystallinity distribution ⁇ is easily increased. When it is 10 hours or less, thermal decomposition due to overheating or overheating of the polyester can be suppressed.
  • the degree of crystallinity ⁇ of the polyester can be varied by controlling the ratio between the supply amount of the hot gas and the input amount of the polyester.
  • the supply amount of heat gas [Nm 3 / Kg] is the polyester 1 kg, it is preferable to 0.1Nm 3 ⁇ 1.5Nm 3.
  • the supply amount of the hot gas is more preferably 0.3 Nm 3 to 1.0 Nm 3 with respect to 1 kg of polyester.
  • the ratio to the supply amount of the hot gas can be adjusted by the wind speed (superficial velocity) of the hot gas passing through the reaction vessel.
  • the hot gas wind speed (superficial velocity) is 0.3 m / sec to 10 m / sec (preferably, 0.5m / sec ⁇ 5.0m / sec ) in a range of from, it is possible to supply the amount of heat gas to polyester 1kg and 0.1Nm 3 ⁇ 1.5Nm 3.
  • the crystallinity distribution ⁇ of polyester obtained by heating (crystallization) is preferably 5% to 13%, particularly preferably 8% to 9%.
  • the crystallite diameter D of the polyester obtained by heating (crystallization) is preferably from 80 to 120 mm, and more preferably from 90 to 100 mm.
  • the crystallite diameter D and the crystallite diameter distribution ⁇ D of the polyester can be obtained as follows.
  • the crystallite diameter D is measured for 100 polyester grains, and from these values, the average value of the crystallite diameter D of the polyester supplied to the reaction vessel is obtained, and the difference between the maximum value and the minimum value of the crystallite diameter D is calculated. Dividing the crystallite diameter D by the average value of the crystallite diameter D (crystallite diameter distribution ⁇ D) is obtained.
  • the crystallite size distribution ⁇ D is preferably 3% to 9%.
  • Solid phase polymerization In the solid phase polymerization step, a polyester having a crystallinity distribution ⁇ of 3% ⁇ ⁇ 15% is supplied to the reaction vessel and subjected to solid phase polymerization.
  • the solid phase polymerization of polyester may be a continuous method (a method in which a tower is filled with a resin, and this is slowly heated for a predetermined period of time while being heated and then sequentially fed out), or a batch method (a resin is placed in a container). Or a method of heating for a predetermined time).
  • the temperature of solid phase polymerization is preferably 170 ° C. to 240 ° C., more preferably 180 ° C. to 230 ° C., and further preferably 190 ° C. to 220 ° C.
  • the amount of terminal COOH (AV) of the polyester is preferably reduced.
  • the solid phase polymerization time is preferably 5 hours to 100 hours, more preferably 10 hours to 75 hours, and further preferably 15 hours to 50 hours. When the time is within the above range, it is preferable in that the terminal COOH amount (AV) and intrinsic viscosity (IV) of the polyester can be easily controlled within the preferable ranges of the present invention.
  • the solid phase polymerization is preferably performed in a vacuum or in a nitrogen atmosphere.
  • the temperature of the polyester when it is put into the reaction vessel is preferably 180 ° C. to 220 ° C. Prior to solid phase polymerization, the temperature of the pellets in the reaction vessel can be set to 180 ° C. to 220 ° C. by preheating the polyester to the above temperature range.
  • the temperature of the polyester when entering the reaction vessel is more preferably 190 ° C. to 210 ° C.
  • the water content of the polyester, the crystallinity, the acid value of the polyester, that is, the concentration of terminal COOH (AV) and the intrinsic viscosity (IV) of the polyester are further increased by solid phase polymerization.
  • the intrinsic viscosity (IV) [unit dl / g] of the polyester is preferably 0.7 to 0.9. When the intrinsic viscosity is 0.7 or more, the molecular motion of the polyester is hindered and it is difficult to crystallize.
  • IV is more preferably 0.70 to 0.85, and particularly preferably 0.73 to 0.80.
  • a titanium (Ti) -based catalyst is used, and further solid-phase polymerization is performed, whereby the intrinsic viscosity (IV) of the polyester is set to 0.7 to 0.9, which will be described later.
  • IV intrinsic viscosity
  • the amount of terminal COOH (AV) can be measured by a titration method according to the method described in H. A. Pohl, Anal. Chem. 26 (1954) 2145. Specifically, polyester is dissolved in benzyl alcohol at 205 ° C., a phenol red indicator is added, titrated with a water / methanol / benzyl alcohol solution of sodium hydroxide, and calculated from the appropriate amount.
  • the polyester used for the solid phase polymerization of the polyester may be a polyester obtained by polymerizing and crystallizing by the above-described esterification reaction or a commercially available polyester in the form of pellets or the like as a starting material.
  • the solid-phase polymerized polyester is extruded into a film.
  • the polyester film is formed by melt-kneading the solid-phase polymerized polyester using an extruder and extruding it from a die (extrusion die).
  • the thickness of the polyester film is preferably 250 ⁇ m to 500 ⁇ m.
  • the extrusion process is further divided into a melt-kneading and extrusion process in which solid-phase polymerized polyester is melted and extruded from a die, a cooling and solidification process in which an unstretched polyester film is cooled and solidified, and an unstretched state after cooling and solidification. And a stretching process for stretching the film.
  • polyester was dried, after the residual moisture 100ppm or less, can be melted by using an extruder.
  • the melting temperature is preferably 250 ° C to 320 ° C, more preferably 260 ° C to 310 ° C, and further preferably 270 ° C to 300 ° C.
  • the extruder may be uniaxial or multi-axial. It is more preferable that the inside of the extruder is replaced with nitrogen from the viewpoint that generation of terminal COOH due to thermal decomposition can be further suppressed.
  • the melted molten resin (melt) is extruded from an extrusion die through a gear pump, a filter or the like. At this time, it may be extruded as a single layer or may be extruded as a multilayer.
  • the melt extruded from the extrusion die can be solidified using a chill roll (cooling roll).
  • the temperature of the chill roll is preferably 10 ° C. to 80 ° C., more preferably 15 ° C. to 70 ° C., and still more preferably 20 ° C. to 60 ° C.
  • the thickness after stretching is 250 ⁇ m or more films
  • thick film be effectively cooling can be performed.
  • the cooling is insufficient, spherulites are likely to be generated, which may cause uneven stretching and uneven thickness.
  • the polyester film of the present invention can be suitably produced by biaxially stretching the produced extruded film (unstretched film).
  • an unstretched polyester film is led to a group of rolls heated to a temperature of 70 ° C. to 140 ° C., and stretched at a stretch ratio of 3 to 5 times in the longitudinal direction (longitudinal direction, that is, the traveling direction of the film).
  • the film is preferably stretched and cooled by a roll group having a temperature of 20 ° C. to 50 ° C.
  • the film is guided to a tenter while holding both ends of the film with clips, and stretched in a direction perpendicular to the longitudinal direction (width direction) by 3 to 5 times in an atmosphere heated to a temperature of 80 ° C. to 150 ° C. Stretch with.
  • the stretching ratio is preferably 3 to 5 times in each of the longitudinal direction and the width direction.
  • the area ratio (longitudinal draw ratio ⁇ lateral draw ratio) is preferably 9 to 15 times.
  • the area magnification is 9 times or more, the reflectivity, concealability and film strength of the obtained biaxially stretched laminated film are good, and when the area magnification is 15 times or less, tearing during stretching should be avoided. Can do.
  • the simultaneous biaxial stretching method in addition to the sequential biaxial stretching method in which the longitudinal direction and the width direction are separated separately, the simultaneous biaxial stretching method in which the longitudinal direction and the width direction are simultaneously stretched. Either may be sufficient.
  • the melting point (Tm) above the glass transition temperature (Tg) of the resin, which is preferably the raw material, is preferably continued in the tenter.
  • Heat treatment is performed at a temperature less than 1 second to 30 seconds, and after uniform cooling, cool to room temperature.
  • the heat treatment temperature is preferably higher.
  • the heat treatment temperature is too high, the orientation crystallinity is lowered, and as a result, the formed film may be inferior in hydrolysis resistance.
  • the heat treatment temperature (Ts) of the polyester film of the present invention is preferably 40 ° C. ⁇ (Tm ⁇ Ts) ⁇ 90 ° C. More preferably, the heat treatment temperature (Ts) is 50 ° C. ⁇ (Tm ⁇ Ts) ⁇ 80 ° C., more preferably 55 ° C. ⁇ (Tm ⁇ Ts) ⁇ 75 ° C.
  • the polyester film of the present invention can be used as a back sheet constituting a solar cell power generation module
  • the atmospheric temperature may rise to about 100 ° C. when the module is used, so the heat treatment temperature (Ts) is It is preferably 160 ° C. or higher and Tm ⁇ 40 ° C. (where Tm ⁇ 40 ° C.> 160 ° C.) or lower. More preferably Tm-50 °C 170 °C or higher (provided that, Tm-50 °C> 170 °C) or less, more preferably Ts is Tm-55 °C 180 °C or higher (provided that, Tm-55 °C> 180 °C) or less.
  • relaxation treatment of 3% to 12% may be performed in the width direction or the longitudinal direction.
  • the relaxation ratio “3% to 12%” in the relaxation treatment is calculated by the following formula (c), where La is the length of the polyester film before relaxation and Lb is the length of the polyester film after relaxation.
  • Formula (c) 100 ⁇ (La ⁇ Lb) / La
  • the width direction of La and Lb of the polyester film, as well as the longitudinal direction of La and Lb of the polyester film is defined as follows. [Width direction]
  • the maximum width of the polyester film at the time of stretching when the polyester film is stretched with a tenter is defined as the length La of the polyester film before relaxation.
  • tensile_strength (relaxing) and taking out a polyester film from a tenter be length Lb of the polyester film after relaxation
  • Longitudinal direction When the polyester film is stretched by applying tension to the polyester film with a tenter, two points are marked in the longitudinal direction, and the distance between the two points is the length La of the polyester film before relaxation. Further, the distance between the two points after the tension is released (relaxed) and taken out from the tenter is defined as the length Lb of the relaxed polyester film.
  • the intrinsic viscosity (IV) and terminal COOH amount (AV) of the polyester film produced by the method for producing a polyester film of the present invention are controlled through the solid phase polymerization.
  • the intrinsic viscosity (IV) [unit dl / g] of the polyester film is preferably in the range of 0.7 to 0.9, more preferably 0.7 to 0.85, and particularly preferably 0.73 to 0. .80.
  • IV is 0.7 or more, the molecular weight of the polyester is maintained in a desired range, and when the polyester film has a multilayer structure, good adhesion without cohesive failure can be obtained at the adhesion interface with other layers.
  • IV is 0.9 or less, the melt viscosity during film formation is good, thermal decomposition of the polyester due to shearing heat generation is suppressed, and the amount of terminal COOH (AV) can be suppressed low.
  • the polyester film produced by the method for producing a polyester film of the present invention can make the terminal COOH amount (AV) in the longitudinal direction difficult to vary.
  • AV terminal COOH amount
  • a film or sheet in order to obtain a constant film thickness, it is desired to melt and extrude with a constant discharge amount.
  • uniaxial tandem extrusion or gear pump assist is desired.
  • a twin screw extruder of the type is preferred and used.
  • a film having a constant thickness can be obtained with the above apparatus, but in that case, the screw rotation speed of the extruder fluctuates, and as a result, thermal decomposition of PET in the extruder (increase in terminal COOH) ) Occurs in response to fluctuations in the screw speed.
  • the terminal COOH varies in the longitudinal direction of the film, resulting in non-uniform hydrolysis resistance in the longitudinal direction.
  • the fluctuation of the discharge amount when the polyester is melt-extruded with a constant screw rotation is reduced, and as a result, a constant film thickness can be obtained while the terminal COOH due to the fluctuation of thermal decomposition is obtained. Fluctuations can be suppressed. This is considered to be a phenomenon similar to the effect of reducing the extrusion load by the lubricant.
  • FIG. 2 is a schematic view of a polyester film having a long shape for explaining a method for evaluating the variation in the amount of terminal COOH of the polyester film.
  • FIG. 2 shows a polyester film 20, and arbitrary points P 1 , P 2 , P 3, P n + 1 , P n (these are collectively referred to as “point P”) are shown on the polyester film 20.
  • the points P are lined up at 100 m intervals in the longitudinal direction (MD; Machine Direction) of the polyester film 20. Between the point P3 and the point P n + 1, may have a point which is not further shown, may not have. Further, the point P is located at the center of the polyester film 20 in the width direction (TD; Transverse Direction).
  • MD Machine Direction
  • the point P is a position where the terminal COOH amount of the polyester film is measured, and the variation in the terminal COOH amount of the polyester film is calculated by measuring the terminal COOH amount at n points P.
  • a rectangular (a broken line frame shown in FIG. 2) sample piece is cut so that the point P is the center, and the terminal COOH amount is measured for the obtained n sample pieces, and the terminal COOH amount is measured.
  • the average value of the terminal COOH, the maximum value of the terminal COOH amount, and the minimum value of the terminal COOH amount are examined.
  • the variation of the terminal COOH amount is evaluated from the average value, the maximum value, and the minimum value of the measured terminal COOH amount.
  • the number (n) of positions for measuring the terminal COOH amount of the polyester film is 20 points.
  • the terminal COOH amount of the polyester film is preferably such that the variation in the amount of terminal COOH in the longitudinal direction of the film is less than 2 (eq / ton) with respect to the terminal COOH of the polyester. “The variation in the amount of terminal COOH is less than 2 (eq / ton)” means that the difference between the maximum value and the minimum value of the terminal COOH amount is in the range of less than 2 (eq / ton).
  • the variation in the amount of the terminal COOH in the longitudinal direction of the polyester film is more preferably 1 (eq / ton) or less. In the present specification, “eq / ton” represents a molar equivalent per ton.
  • the breaking elongation after storage is higher than the breaking elongation before storage. Therefore, the storage time (breaking elongation half-life) of 50% is preferably 70 hours or more.
  • the elongation at break half time is more preferably 100 hours or more, and still more preferably 120 hours or more.
  • the hydrolysis resistance of the polyester film can be evaluated by the half elongation time at break. This is calculated
  • the elongation at break [%] is a value obtained by cutting a sample piece having a size of 1 cm ⁇ 20 cm from a polyester film and pulling the sample piece at a rate of 5 cm between chucks and 20% / min.
  • Polyester films generally have poor hydrolysis resistance with increasing thickness, and tend not to withstand long-term use in harsh use environments such as exposure to wind and rain or direct sunlight.
  • the polyester film obtained by the method for producing a polyester film of the present invention has excellent hydrolysis resistance, and further, there is little variation in the amount of terminal COOH in the longitudinal direction of the polyester film. Because the variation in the amount of terminal COOH in the longitudinal direction of the polyester film is small, the variation in the half elongation time of the polyester film can be reduced, and the variation in the half elongation time of the polyester film is less likely to occur. Over time, the film functionality is less likely to vary. Therefore, when the polyester film obtained by the method for producing a polyester film of the present invention is configured as a solar cell power generation module, for example, desired power generation performance can be stably obtained over a long period of time.
  • the polyester film produced by the method for producing a polyester film of the present invention preferably has a thickness after stretching of 250 ⁇ m to 500 ⁇ m.
  • the polyester film obtained by the method for producing a polyester film of the present invention can be constituted by providing at least one functional layer such as an easy-adhesive layer, a UV absorbing layer, and a white layer.
  • the following functional layer may be applied to a polyester film after uniaxial stretching and / or biaxial stretching.
  • a known coating technique such as a roll coating method, a knife edge coating method, a gravure coating method, or a curtain coating method can be used.
  • surface treatment flame treatment, corona treatment, plasma treatment, ultraviolet treatment, etc.
  • the polyester film may have an easy-adhesive layer on the side facing the sealing material of the battery side substrate in which the solar cell element is sealed with a sealing agent.
  • the easy-adhesive layer By providing the easy-adhesive layer, the back sheet and the sealing material can be firmly bonded.
  • the easily adhesive layer has an adhesive force of 10 N / cm or more, preferably 20 N / cm or more, particularly with EVA (ethylene-vinyl acetate copolymer) used as a sealing material.
  • EVA ethylene-vinyl acetate copolymer
  • the easy-adhesion layer needs to prevent the back sheet from peeling off during use of the solar cell power generation module, and therefore, the easy-adhesion layer desirably has high moisture and heat resistance.
  • Binder The easy-adhesion layer can contain at least one binder.
  • the binder for example, polyester, polyurethane, acrylic resin, polyolefin, or the like can be used. Among these, acrylic resins and polyolefins are preferable as the binder from the viewpoint of durability.
  • acrylic resin a composite resin of acrylic and silicone is also preferable. The following can be mentioned as an example of a preferable binder.
  • polyolefins include Chemipearl S-120 and S-75N (both trade names, manufactured by Mitsui Chemicals, Inc.).
  • Examples of the acrylic resin include Julimer ET-410 and SEK-301 (both trade names, manufactured by Nippon Pure Chemical Industries, Ltd.).
  • Examples of the composite resin of acrylic and silicone include Ceranate WSA 1060, WSA 1070 (both manufactured by DIC Corporation), and H7620, H7630, H7650 (both trade names, manufactured by Asahi Kasei Chemicals Corporation).
  • the amount of the binder in the easy adhesion layer is preferably in the range of 0.05g / m 2 ⁇ 5g / m 2, the range of 0.08g / m 2 ⁇ 3g / m 2 is particularly preferred.
  • the binder amount is more good adhesion is obtained by at 0.05 g / m 2 or more, a better surface is obtained by at 5 g / m 2 or less.
  • the easy-adhesion layer can contain at least one kind of fine particles.
  • the easy-adhesive layer preferably contains 5% or more of fine particles with respect to the mass of the entire layer.
  • fine particles inorganic fine particles such as silica, calcium carbonate, magnesium oxide, magnesium carbonate, tin oxide and the like are preferably exemplified. In particular in this, in that reduction of adhesiveness is small when exposed to wet heat atmosphere, tin oxide, silica fine particles are preferred.
  • the particle size of the fine particles can be measured by observing the cross section of the coated film with a scanning electron microscope, preferably about 10 nm to 700 nm, more preferably about 20 nm to 300 nm.
  • the shape of the fine particles is not particularly limited, and those having a spherical shape, an indefinite shape, a needle shape, or the like can be used.
  • the addition amount of the fine particles in the easy-adhesive layer is preferably 5 to 400% by mass, more preferably 50 to 300% by mass, based on the binder in the easy-adhesive layer. When the addition amount of the fine particles is 5% by mass or more, the adhesiveness when exposed to a wet heat atmosphere is excellent, and when it is 400% by mass or less, the surface state of the easily adhesive layer is better.
  • the easy-adhesion layer can contain at least one crosslinking agent.
  • the crosslinking agent include epoxy-based, isocyanate-based, melamine-based, carbodiimide-based, and oxazoline-based crosslinking agents.
  • an oxazoline-based cross-linking agent is particularly preferable from the viewpoint of securing adhesiveness after wet heat aging.
  • oxazoline-based crosslinking agent examples include 2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, 2-isopropenyl-2-oxazoline, 2-isopropenyl-4-methyl-2-oxazoline, 2-isopropenyl-5-ethyl-2-oxazoline, 2,2′-bis- (2-oxazoline), 2,2′-methylene-bis- (2 -Oxazoline), 2,2'-ethylene-bis- (2-oxazoline), 2,2'-trimethylene-bis- (2-oxazoline), 2,2'-tetramethylene-bis- (2-oxazoline), 2,2'-hexamethylene-bis- (2-oxazoline), 2,2'-octamethylene-bis- (2-oxazoline), 2,2'-ethylene-bis- (4,4'-dimethyl) 2-oxazoline), 2,2'-p-pheny
  • (co) polymers of these compounds can also be preferably used.
  • a compound having an oxazoline group Epocros K2010E, K2020E, K2030E, WS500, WS700 (all trade names, manufactured by Nippon Shokubai Chemical Co., Ltd.) and the like can be used.
  • a preferable addition amount of the crosslinking agent in the easy-adhesive layer is preferably 5 to 50% by mass, more preferably 20 to 40% by mass, based on the binder of the easy-adhesive layer.
  • the addition amount of the crosslinking agent is 5% by mass or more, a good crosslinking effect is obtained, and the strength of the reflective layer is not reduced and adhesion failure hardly occurs, and when it is 50% by mass or less, the pot life of the coating liquid is further increased. I can keep it long.
  • a known matting agent such as polystyrene, polymethylmethacrylate or silica, or a known surfactant such as anionic or nonionic is added to the easily adhesive layer. May be.
  • Formation method of an easily-adhesive layer As a formation method of an easily-adhesive layer, there exist the method of pasting the polymer sheet which has easy-adhesiveness to a polyester film, and the method by application
  • the method by coating is preferable in that it can be formed with a simple and highly uniform thin film.
  • a coating method for example, a known method such as a gravure coater or a bar coater can be used.
  • the solvent of the coating solution used for coating may be water or an organic solvent such as toluene or methyl ethyl ketone.
  • a solvent may be used individually by 1 type and may be used in mixture of 2 or more types.
  • the thickness of the easy-adhesion layer is not particularly limited, but is usually preferably 0.05 ⁇ m to 8 ⁇ m, more preferably 0.1 ⁇ m to 5 ⁇ m.
  • the thickness of the easy-adhesive layer is 0.05 ⁇ m or more, the required easy adhesion can be easily obtained, and when the thickness is 8 ⁇ m or less, the planar shape can be maintained better.
  • an easily bonding layer has transparency from a viewpoint which does not impair the effect of this colored layer when a colored layer (especially reflective layer) is arrange
  • the polyester film may be provided with an ultraviolet absorbing layer containing an ultraviolet absorber.
  • An ultraviolet absorption layer can be arrange
  • the ultraviolet absorber is preferably dissolved and dispersed together with an ionomer resin, polyester resin, urethane resin, acrylic resin, polyethylene resin, polypropylene resin, polyamide resin, vinyl acetate resin, cellulose ester resin, and the like.
  • the transmittance is preferably 20% or less.
  • a colored layer can be provided on the polyester film.
  • the colored layer is a layer arranged in contact with the surface of the polyester film or through another layer, and can be constituted using a pigment or a binder.
  • the first function of the colored layer is to increase the power generation efficiency of the solar power generation module by reflecting the incident light that reaches the back sheet without being used for power generation in the solar cells and returning it to the solar cells. It is in.
  • the second function is to improve the decorativeness of the appearance when the solar cell power generation module is viewed from the front side. In general, when the solar battery power generation module is viewed from the front side, a back sheet can be seen around the solar battery cell, and the decorativeness can be improved by providing a colored layer on the back sheet.
  • the colored layer can contain at least one pigment.
  • the pigment is preferably contained in the range of 2.5 g / m 2 to 8.5 g / m 2 .
  • a more preferable pigment content is in the range of 4.5 g / m 2 to 7.5 g / m 2 .
  • the pigment content is 2.5 g / m 2 or more, necessary coloring can be easily obtained, and the light reflectance and decorativeness can be adjusted to be more excellent.
  • the pigment content is 8.5 g / m 2 or less, the planar shape of the colored layer can be maintained better.
  • the pigment examples include inorganic pigments such as titanium oxide, barium sulfate, silicon oxide, aluminum oxide, magnesium oxide, calcium carbonate, kaolin, talc, ultramarine blue, bitumen, and carbon black, and organic pigments such as phthalocyanine blue and phthalocyanine green. It is done.
  • a white pigment is preferable from the viewpoint of constituting a colored layer as a reflective layer that reflects incident sunlight.
  • titanium oxide, barium sulfate, silicon oxide, aluminum oxide, magnesium oxide, calcium carbonate, kaolin, talc and the like are preferable.
  • the average particle size of the pigment is preferably 0.03 ⁇ m to 0.8 ⁇ m, more preferably about 0.15 ⁇ m to 0.5 ⁇ m. When the average particle size is within the above range, the light reflection efficiency is good.
  • the preferred addition amount of pigment in the reflective layer varies depending on the type of pigment used and the average particle diameter, but cannot be generally stated, but 1.5 g / m 2 ⁇ is preferably 15 g / m 2, more preferably from 3g / m 2 ⁇ 10g / m 2 approximately. When the addition amount is 1.5 g / m 2 or more, the required reflectance is easily obtained, and when the addition amount is 15 g / m 2 or less, the strength of the reflection layer can be kept higher.
  • the colored layer can contain at least one binder.
  • the binder is included, the amount is preferably in the range of 15% by mass to 200% by mass and more preferably in the range of 17% by mass to 100% by mass with respect to the pigment.
  • the amount of the binder is 15% by mass or more, the strength of the colored layer can be more favorably maintained, and when it is 200% by mass or less, the reflectance and decorativeness are prevented from being lowered.
  • a binder suitable for the colored layer for example, polyester, polyurethane, acrylic resin, polyolefin, or the like can be used. From the viewpoint of durability, the binder is preferably an acrylic resin or a polyolefin.
  • the acrylic resin a composite resin of acrylic and silicone is also preferable.
  • Examples of preferred binders include the following.
  • Examples of the polyolefin include Chemipearl S-120 and S-75N (both trade names, manufactured by Mitsui Chemicals, Inc.).
  • Examples of the acrylic resin include Julimer ET-410 and SEK-301 (both trade names, manufactured by Nippon Pure Chemical Industries, Ltd.).
  • Examples of the composite resin of acrylic and silicone include Ceranate WSA1060, WSA1070 (both trade names, manufactured by DIC Corporation), H7620, H7630, H7650 (both trade names, manufactured by Asahi Kasei Chemicals Corporation), and the like. Can do.
  • ком ⁇ онент In addition to the binder and the pigment, a crosslinking agent, a surfactant, a filler, and the like may be further added to the colored layer as necessary.
  • crosslinking agent examples include epoxy-based, isocyanate-based, melamine-based, carbodiimide-based, and oxazoline-based crosslinking agents.
  • the addition amount of the crosslinking agent in the colorant is preferably 5% by mass to 50% by mass and more preferably 10% by mass to 40% by mass with respect to the binder of the colored layer.
  • the addition amount of the crosslinking agent is 5% by mass or more, a good crosslinking effect can be obtained, the strength and adhesiveness of the colored layer can be maintained high, and when it is 50% by mass or less, the coating solution The pot life can be maintained longer.
  • the surfactant a known surfactant such as an anionic or nonionic surfactant can be used.
  • the addition amount of the surfactant is preferably 0.1 mg / m 2 to 15 mg / m 2 , more preferably 0.5 mg / m 2 to 5 mg / m 2 .
  • the amount of the surfactant added is 0.1 mg / m 2 or more to effectively suppress the occurrence of repelling, and the amount added is 15 mg / m 2 or less to provide excellent adhesion.
  • a filler such as silica may be added to the colored layer in addition to the above pigment.
  • the addition amount of the filler is preferably 20% by mass or less, more preferably 15% by mass or less per binder of the colored layer.
  • the strength of the colored layer can be increased.
  • the ratio of a pigment can be maintained because the addition amount of a filler is 20 mass% or less, favorable light reflectivity (reflectance) and decorativeness are obtained.
  • a forming method of the colored layer there are a method of pasting a polymer sheet containing a pigment on a polyester film, a method of co-extruding a colored layer at the time of forming a polyester film, a method by coating, and the like.
  • the method by coating is preferable in that it can be formed with a simple and highly uniform thin film.
  • a coating method for example, a known method such as a gravure coater or a bar coater can be used.
  • the solvent of the coating solution used for coating may be water or an organic solvent such as toluene or methyl ethyl ketone. However, from the viewpoint of environmental burden, it is preferable to use water as a solvent.
  • a solvent may be used individually by 1 type and may be used in mixture of 2 or more types.
  • the colored layer preferably contains a white pigment and is configured as a reflective layer.
  • the light reflectance at 550 nm in the case of the reflective layer is preferably 75% or more. When the reflectance is 75% or more, sunlight that has passed through the solar battery cell and has not been used for power generation can be returned to the cell, and the effect of increasing power generation efficiency is high.
  • the thickness of the reflective layer is preferably 1 ⁇ m to 20 ⁇ m, more preferably about 1.5 ⁇ m to 10 ⁇ m.
  • the film thickness is 1 ⁇ m or more, necessary decoration and reflectance are easily obtained, and when it is 20 ⁇ m or less, the surface shape may be deteriorated.
  • An undercoat layer can be provided on the polyester film.
  • the undercoat layer may be provided between the colored layer and the polyester film.
  • the undercoat layer can be formed using a binder, a crosslinking agent, a surfactant, and the like.
  • binder contained in the undercoat layer examples include polyester, polyurethane, acrylic resin, and polyolefin.
  • an epoxy, isocyanate, melamine, carbodiimide, oxazoline, or other crosslinking agent, anionic or nonionic surfactant, silica or other filler may be added to the undercoat layer.
  • the solvent may be water or an organic solvent such as toluene or methyl ethyl ketone.
  • a solvent may be used individually by 1 type and may be used in mixture of 2 or more types.
  • Coating may be applied to a polyester film after biaxial stretching, it may be applied to a polyester film after uniaxial stretching. In this case, the film may be further stretched in a direction different from the initial stretching after coating. Furthermore, you may extend
  • the thickness of the undercoat layer is preferably 0.05 ⁇ m to 2 ⁇ m, more preferably about 0.1 ⁇ m to 1.5 ⁇ m. When the film thickness is 0.05 ⁇ m or more, the necessary adhesiveness is easily obtained, and when it is 2 ⁇ m or less, the surface shape can be favorably maintained.
  • -Fluorine resin layer / Si resin layer- It is preferable to provide at least one of a fluorine-type resin layer and a Si-type resin layer in a polyester film.
  • a fluorine-based resin layer or the Si-based resin layer it is possible to prevent contamination of the polyester surface and improve weather resistance.
  • it is also preferable to stick together fluorine resin films such as Tedlar (trade name, manufactured by DuPont).
  • each of the fluorine-based resin layer and the Si-based resin layer is preferably in the range of 1 ⁇ m to 50 ⁇ m, more preferably in the range of 3 ⁇ m to 40 ⁇ m.
  • the polyester film is provided with an inorganic layer.
  • the inorganic layer By providing the inorganic layer to prevent ingress of water or gas into the polyester, it is possible to provide a function as a vapor barrier and gas barrier layer.
  • the inorganic layer may be provided on either the front or back side of the polyester film, but from the viewpoint of waterproofing, moisture proofing, etc., the side opposite to the battery side substrate of the polyester film (the side on which the colored layer or easy adhesion layer is formed) Are preferably provided.
  • the water vapor transmission rate (moisture permeability) of the inorganic layer is preferably 10 0 g / m 2 ⁇ d to 10 -6 g / m 2 ⁇ d, more preferably 10 -1 g / m 2 ⁇ d to 10 -5 g. / M 2 ⁇ d, and more preferably 10 -2 g / m 2 ⁇ d to 10 -4 g / m 2 ⁇ d.
  • the following dry method is preferably used.
  • a gas barrier inorganic layer (hereinafter also referred to as a gas barrier layer) by a dry method, resistance heating vapor deposition, electron beam vapor deposition, induction heat vapor deposition, and vacuum vapor deposition such as an assist method using plasma or ion beam for these.
  • Examples include chemical vapor deposition (CVD).
  • CVD chemical vapor deposition
  • a vacuum vapor deposition method in which a film is formed by a vapor deposition method under vacuum is preferable.
  • the material forming the gas barrier layer is mainly composed of inorganic oxide, inorganic nitride, inorganic oxynitride, inorganic halide, inorganic sulfide, etc.
  • the same material as the composition of the gas barrier layer to be formed It is possible to directly volatilize and deposit it on a substrate or the like.
  • this method when this method is used, the composition changes during volatilization, and as a result, the formed film may not exhibit uniform characteristics. is there.
  • a material having the same composition as the barrier layer formed as a volatilization source is used, oxygen gas in the case of inorganic oxide, nitrogen gas in the case of inorganic nitride, oxygen gas and nitrogen in the case of inorganic oxynitride
  • An inorganic group is used as a volatile source. And this After forming an inorganic group layer, it is an oxygen gas atmosphere in the case of an inorganic oxide, a nitrogen gas atmosphere in the case of an inorganic nitride, and an oxygen gas and a nitrogen gas in the case of an inorganic oxynitride.
  • Examples of the method include a method of reacting an introduced gas with an inorganic layer by holding in a mixed gas atmosphere, a halogen-based gas atmosphere in the case of an inorganic halide, and a sulfur-based gas atmosphere in the case of an inorganic sulfide.
  • 2) or 3) is more preferably used because it is easy to volatilize from a volatile source.
  • the method 2) is more preferably used because the film quality can be easily controlled.
  • the barrier layer is an inorganic oxide
  • the inorganic group is used as a volatilization source, volatilized to form an inorganic group layer, and then left in the air to naturally oxidize the inorganic group.
  • the method is also preferable because it is easy to form.
  • the thickness is preferably 1 ⁇ m to 30 ⁇ m.
  • the thickness is 1 ⁇ m or more, water hardly penetrates into the polyester film during the lapse of time (thermo) and hardly causes hydrolysis, and when it is 30 ⁇ m or less, the thickness of the barrier layer does not become too thick, and the barrier layer The stress does not cause the film to bend.
  • the polyester resin composition of the present invention is particularly suitably used as a polyester film or a polyester sheet for outdoor use that requires weather resistance.
  • a polyester film or polyester sheet for outdoor use for example, a back sheet provided in a solar cell power generation module (a sheet for protecting the back surface that is disposed on the side opposite to the side on which sunlight is incident to protect the solar cell element), lighting Film, agricultural sheet, and the like, and particularly suitable as a back sheet provided in a solar cell power generation module.
  • the solar cell power generation module of the present invention includes a polyester film (including a back sheet) obtained by the above-described method for producing a polyester film of the present invention.
  • a transparent substrate on which sunlight is incident eg, a glass substrate
  • a solar cell element that converts light energy of sunlight into electric energy e.g., a sealing agent that seals the solar cell element, and the like Constructed using.
  • the polyester film obtained by the method for producing a polyester film of the present invention is applied to a back sheet, the back sheet is provided on the side of the solar cell element opposite to the side on which the transparent substrate is disposed. .
  • Solar cell elements include silicon-based materials such as single crystal silicon, polycrystalline silicon, and amorphous silicon, III-V groups such as copper-indium-gallium-selenium, copper-indium-selenium, cadmium-tellurium, gallium-arsenic, and II Various known solar cell elements such as a group VI compound semiconductor can be applied.
  • Example 1 Production of polyester (solid phase polymerization process) -Polymerization (esterification reaction)- [Step (A)]
  • 4.7 tons of high-purity terephthalic acid and 1.8 tons of ethylene glycol are mixed for 90 minutes to form a slurry, and continuously at a flow rate of 3800 kg / h. Supplied to.
  • an ethylene glycol solution of a citric acid chelate titanium complex (VERTEC AC-420, trade name, manufactured by Johnson Matthey) in which citric acid is coordinated to Ti metal is continuously supplied, and the temperature in the reaction vessel is 250 ° C. with stirring.
  • the reaction was carried out with an average residence time of about 4.3 hours.
  • the citric acid chelate titanium complex was continuously added so that the amount of Ti added was 9 ppm in terms of element.
  • the acid value of the obtained oligomer was 600 eq / ton.
  • This reaction product was transferred to a second esterification reaction vessel, and reacted with stirring at a temperature in the reaction vessel of 250 ° C. and an average residence time of 1.2 hours to obtain an oligomer having an acid value of 200 eq / ton.
  • the inside of the second esterification reaction tank is partitioned into three zones, and an ethylene glycol solution of magnesium acetate is continuously supplied from the second zone so that the amount of Mg added is 75 ppm in terms of element, From the third zone, an ethylene glycol solution of trimethyl phosphate was continuously supplied so that the added amount of P was 65 ppm in terms of element. As a result, an esterification reaction product was obtained.
  • Ti / P (element content ratio of Ti and P) was 0.14.
  • the ethylene glycol solution of trimethyl phosphate was prepared by adding a 25 ° C. trimethyl phosphate solution to a 25 ° C. ethylene glycol solution and stirring at 25 ° C. for 2 hours (phosphorus compound content in the solution: 3 .8%).
  • Step (B) The esterification reaction product obtained in the step (A) is continuously supplied to the first polycondensation reaction tank, and with stirring, the reaction temperature is 270 ° C. and the reaction tank pressure is 20 torr (2.67 ⁇ 10 ⁇ 3 MPa). The polycondensation (transesterification reaction) was carried out with an average residence time of about 1.8 hours.
  • reaction from the first condensation polymerization reactor tank was transferred to a second condensation polymerization reactor tank, stirring in the reaction vessel, the reaction vessel temperature 276 ° C., the reaction vessel pressure 5torr (6.67 ⁇ 10 - 4 MPa), and the reaction (transesterification reaction) was carried out under the condition that the residence time was about 1.2 hours.
  • this reaction product was further transferred from the second double condensation reaction tank to the third triple condensation reaction tank.
  • the reaction vessel internal temperature was 278 ° C. and the reaction vessel internal pressure was 1.5 torr (2.0 ⁇ 10 6 -4 MPa) at a residence time of 1.5 hours (transesterification reaction) to obtain a polycondensate (polyethylene terephthalate (PET)).
  • PET polyethylene terephthalate
  • PET polycondensate
  • the amount of terminal COOH (AV) [eq / ton] and the intrinsic viscosity (IV) [dl / g] were measured.
  • the amount of terminal COOH was determined by titration according to the method described in H. A. Pohl, Anal. Chem. 26 (1954) 2145. Specifically, PET pellet 1 was dissolved in benzyl alcohol at 205 ° C., phenol red indicator was added, titrated with a water / methanol / benzyl alcohol solution of sodium hydroxide, and the amount of terminal COOH was calculated from the appropriate amount.
  • the intrinsic viscosity and the amount of terminal COOH of the PET pellet 1 before solid phase polymerization are shown in “Before solid phase polymerization”, “Resin”, “IV” column and “AV” column of Table 1.
  • a crystallization apparatus having the structure shown in FIG. 1 is prepared, and PET pellets 1 are charged at an input amount of 300 kg / hr from an opening (opening 8) at the top of the crystallization apparatus, and nitrogen at 180 ° C. is supplied to the crystallization apparatus.
  • the gas was supplied at a supply rate of 200 Nm 3 / hr.
  • the wind speed (superficial velocity) of nitrogen gas was 1.0 m / sec.
  • the PET pellet 1 dropped on the lower part of the crystallizer was heated (crystallized) for 4 hours by repeatedly lifting it up to the opening (opening 8) and dropping it with a circulation device built in the crystallizer.
  • crystallinity ⁇ ⁇ (d ⁇ dA) / (dC ⁇ dA) ⁇ ⁇ 100. ] was calculated.
  • the average value of the obtained crystallinity ⁇ is shown in the “resin after crystallization” and “ ⁇ ” columns in Table 1. Further, the distribution ⁇ of the obtained crystallinity ⁇ is shown in the “ ⁇ ” column.
  • the crystallite diameter D of 100 crystallized PET pellets was measured by X-ray diffraction analysis using Cu—K ⁇ 1 line, using the Scherrer equation described above.
  • ULTIMA IV manufactured by Rigaku Corporation was used as the X-ray diffraction analyzer.
  • the average value of the obtained crystallite diameters D is shown in the “resin after crystallization” and “D” columns in Table 1. Further, the distribution ⁇ D of the obtained crystallite diameter D is shown in the “ ⁇ D” column.
  • the crystallized PET pellet 1 was subjected to a heat treatment at 180 ° C. for 60 hours under a reduced pressure of 50 Pa using a rotary vacuum polymerization apparatus. At this time, the amount of decrease in the terminal COOH concentration when the intrinsic viscosity increased by 0.1 was 1.5 eq / ton. The measurement was performed by the following method. Thereafter, nitrogen gas at 25 ° C. was flowed into the vacuum polymerization apparatus, and the PET pellet 1 was cooled to 25 ° C. to obtain a solid-state polymerized PET pellet 1.
  • the melt (melt) of the PET pellet 1 was passed through a gear pump and a filter (pore diameter 20 ⁇ m), and then extruded from a die onto a 20 ° C. cooling roll to obtain an amorphous sheet having a thickness of 3500 ⁇ m.
  • the extruded melt was brought into close contact with the cooling roll using an electrostatic application method.
  • both ends were trimmed by 10 cm. Then, after extruding (knurling) with a width of 10 mm at both ends, it was wound up with a tension of 25 kg / m. The width was 1.5 m and the winding length was 2000 m.
  • the polyester film 1 was produced as described above.
  • the amount of terminal COOH was measured by a titration method according to the method described in H. A. Pohl, Anal. Chem. 26 (1954) 2145. Specifically, 20 measurement positions (points P) are marked in the longitudinal direction of the obtained polyester film 1 as shown in FIG. 2 (the interval between the points P is 100 m), and the point P is the center. The polyester film 1 was cut so that 20 pieces of 1 cm ⁇ 20 cm sample pieces were obtained.
  • the average value of the calculated amount of terminal COOH is shown in the “film”, “AV”, and “average” columns of Table 1. Further, the variation in the amount of terminal COOH was calculated from the calculated average value, maximum value, and minimum value of the terminal COOH amount, and indicated in the “AV” and “variation” columns.
  • Example 2 Example 3
  • Example 1 Example 1
  • Example 2 Example 3
  • Example 3 Example 1
  • the temperature of nitrogen gas in the crystallization of the PET pellet 1 was changed from 180 ° C. to the temperature shown in Table 1
  • the solid phase polymerization conditions of the PET pellet were changed as shown in Table 1.
  • polyester films 2 and 3 were prepared, and physical properties were evaluated. The results of evaluation are shown in Table 1 below.
  • Example 4 In Example 2, instead of PET pellet 1, PET pellet 2 having different IV and AV before solid-phase polymerization was used, and the pressure fluctuation of the extruder in the extrusion molding process was changed as shown in Table 1, and the same manner was performed. A polyester film 4 was produced and evaluated for physical properties. The results of evaluation are shown in Table 1 below. PET pellet 2 was obtained as follows.
  • PET pellet 2 In the production of the PET pellet 1, each temperature of the first polycondensation reaction tank, the second double condensation reaction tank, and the third triple condensation reaction tank in “1. Production of polyester” and “Step (B)” in Example 1 is set. PET pellet 2 was prepared in the same manner except that the temperature was lowered by 5 ° C. The intrinsic viscosity (IV) and terminal COOH amount (AV) before solid phase polymerization of the obtained PET pellet 2 were measured in the same manner as the IV and AV measurements of the PET pellet 1 before solid phase polymerization.
  • IV intrinsic viscosity
  • AV terminal COOH amount
  • Example 5 Example 5 (Examples 5 to 7 and Comparative Example 5)
  • Example 2 except that the superficial velocity of nitrogen gas in the heating (crystallization) of the PET pellet 1 was changed to the velocity shown in Table 1, and the pressure fluctuation of the extruder in the extrusion molding process was changed as shown in Table 1.
  • polyester films 5 to 7 Examples 5 to 7
  • a polyester film 105 Comparative Example 5 were prepared and evaluated for physical properties. The results of evaluation are shown in Table 1 below.
  • Example 8 In Example 3, the PET pellet 1 was heated (crystallized) by a metal contact method using a torus disk preheater manufactured by Hosokawa Micron Corporation, and the solid phase polymerization conditions of the PET pellet were changed as shown in Table 1. Produced a polyester film 8 of Example 8 in the same manner. The heating temperature and heating time by metal contact are shown in Table 1. The obtained polyester film 8 was measured and evaluated in the same manner as the polyester film 1 of Example 1. The results of measurement and evaluation are shown in Table 1 below.
  • Comparative Examples 1 to 4 In Examples 1 to 4, the PET pellets were heated (crystallized) by a metal contact method using a torus disk preheater manufactured by Hosokawa Micron Corporation, and the solid phase polymerization conditions for the PET pellets and the extruder used in the extrusion process
  • the polyester films 101 to 104 of Comparative Examples 1 to 4 were produced in the same manner except that the pressure fluctuation was changed as shown in Table 1.
  • the heating temperature and heating time by metal contact are shown in Table 1.
  • the obtained polyester films 101 to 104 were measured and evaluated in the same manner as the polyester film 1 of Example 1. The results of measurement and evaluation are shown in Table 1 below.
  • Example 9 In Example 2, the polyester film 9 of Example 9 was produced in the same manner except that polybutylene terephthalate (PBT) pellets were used instead of the PET pellets 1, and physical properties were evaluated. The results of evaluation are shown in Table 1 below. PBT pellets were obtained as follows.
  • PET1 shown in “solid phase polymerization”
  • resin and “seed” indicates that PET pellet 1 is used as a pellet
  • PET2 uses PET pellet 2 as a pellet
  • PBT indicates that PBT pellets are used as pellets.
  • the crystallinity distribution ⁇ of the polyester after crystallization is large and the pressure fluctuation in the extruder is small compared to the comparative example, and the terminal COOH amount of the obtained polyester film is small. And variations in half elongation time at break are small. Therefore, when the crystallinity distribution ⁇ of the polyester after crystallization is larger in the range of 15% or less, pressure fluctuation in the extruder is suppressed, the amount of terminal COOH of the polyester is reduced, and variation in the amount of terminal COOH is reduced. It was found that variations in the half elongation time at break were suppressed.
  • Example 10 4 Production of polyester film for solar cell (back sheet for solar cell) Using the polyester films 1 to 9 of Examples 1 to 9 and the polyester films 101 to 105 of Comparative Examples 1 to 5 produced above, Back sheets 1 to 9 and 101 to 105 included in the battery were produced. Specifically, it is as follows.
  • the reflective layer-forming coating solution obtained above is applied to a sample film with a bar coater and dried at 180 ° C. for 1 minute to form a reflective layer (white layer) with a titanium dioxide coating amount of 6.5 g / m 2. did.
  • the polyester film is provided with the following (iii) undercoat layer, (iv) barrier layer, and (v) antifouling layer on the side opposite to the side where the reflective layer and the easy-adhesion layer of the polyester film are formed. Coated sequentially from the side.
  • Undercoat layer Various components having the following composition are mixed to prepare a coating solution for an undercoat layer, this coating solution is applied to a polyester film, dried at 180 ° C. for 1 minute, and an undercoat layer (dry coating amount: about 0.1 g / m 2 ) was formed.
  • (V) Antifouling Layer As shown below, a coating solution for forming the first and second antifouling layers is prepared, and the first antifouling layer coating solution and the second antifouling layer are formed on the barrier layer. The coating solution was applied in the order, and a two-layer antifouling layer was applied.
  • ⁇ First antifouling layer> Preparation of coating solution for first antifouling layer- Components in the following composition were mixed to prepare a first antifouling layer coating solution.
  • ⁇ Composition of coating solution> ⁇ Ceranate WSA1070 (trade name, manufactured by DIC Corporation) ⁇ ⁇ ⁇ 45.9 parts ⁇ Oxazoline compound (crosslinking agent) ⁇ ⁇ ⁇ ⁇ ⁇ 7.7 parts (Epocross WS-700, trade name, manufactured by Nippon Shokubai Co., Ltd.) , Solid content: 25%) ⁇ Polyoxyalkylene alkyl ether ... 2.0 parts (Naroacty CL95, trade name, manufactured by Sanyo Chemical Industries, solid content: 1%) ⁇ Pigment dispersion used in the reflective layer: 33.0 parts ⁇ Distilled water: 11.4 parts
  • the obtained coating solution was coated on the barrier layer so that the binder coating amount was 3.0 g / m 2 and dried at 180 ° C. for 1 minute to form a first antifouling layer.
  • Second antifouling layer The prepared coating solution for the second antifouling layer was applied on the first antifouling layer formed on the barrier layer so that the binder coating amount was 2.0 g / m 2 , and the mixture was applied at 180 ° C. for 1 minute. A second antifouling layer was formed by drying.
  • a back sheet having a reflective layer and an easy adhesion layer on one side of the polyester film and having an undercoat layer, a barrier layer, and an antifouling layer on the other side was produced.
  • the solar cell backsheets 1 to 9 of the examples are configured using the polyester films 1 to 9 of the examples with small variations in the half elongation time at break, the backsheets 101 to 105 for the solar cells of the comparative examples are used. In comparison, it showed uniform hydrolysis resistance.
  • Example 11 5 Production of Solar Cell Power Generation Module Using the backsheets 1 to 9 and the backsheets 101 to 105 produced as described above, they are bonded to a transparent filler so as to have the structure shown in FIG. 1 of JP-A-2009-158952. Solar cell power generation modules 1 to 9 and 101 to 105 were produced. At this time, it stuck so that the easily-adhesive layer of a backsheet might contact the transparent filler which embeds a solar cell element.
  • the solar cell power generation modules 1 to 9 of the examples are configured using the polyester films 1 to 9 of the examples with small variations in the half elongation time at break, compared with the solar cell power generation modules 101 to 105 of the comparative examples, The power generation performance can be obtained stably over a long period of time.

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Abstract

A method for producing a polyester film comprises: a solid state polymerization step for performing solid state polymerization by supplying polyester having a crystallinity distribution (Δρ) satisfying 3%<Δρ≤15%, in a reaction vessel; and an extrusion molding step for extrusion molding the polyester subjected to the solid state polymerization into a film shape.

Description

ポリエステルフィルムの製造方法、太陽電池用ポリエステルフィルム、及び、太陽電池発電モジュールPolyester film manufacturing method, polyester film for solar cell, and solar cell power generation module
　本発明は、ポリエステルフィルムの製造方法、太陽電池用ポリエステルフィルム、及び、太陽電池発電モジュールに関する。 The present invention relates to a method for producing a polyester film, a polyester film for solar cells, and a solar cell power generation module.
　地球環境の保護の観点から、太陽光を電気に変換する太陽光発電が注目されている。この太陽光発電に用いられる太陽電池発電モジュールは、太陽光が入射するガラスの上に、（封止剤）／太陽電池素子／封止剤／バックシートがこの順に積層された構造を有するものである。
　太陽電池発電モジュールの太陽光入射側とは反対側に配される裏面保護フィルム（いわゆるバックシート）には、ポリエステルなどの樹脂材料が使用されるに至っている。ポリエチレンテレフタラート（ＰＥＴ）等のポリエステルには、通常はその表面にカルボキシル基や水酸基が多く存在しており、水分が存在する環境では加水分解を起こしやすく、経時で劣化する傾向がある。そのため、屋外等の常に風雨に曝されるような環境におかれる太陽電池発電モジュール等に用いられるポリエステルは、特に、その加水分解性が抑えられていることが求められる。
　また、太陽電池発電モジュール用途以外の屋外用途に適用されるポリエステルについても同様、加水分解性が抑えられていることが求められる。 From the viewpoint of protecting the global environment, photovoltaic power generation that converts sunlight into electricity has attracted attention. The solar cell power generation module used for this solar power generation has a structure in which (sealant) / solar cell element / sealant / back sheet is laminated in this order on glass on which sunlight is incident. is there.
Resin materials such as polyester have been used for the back surface protective film (so-called back sheet) disposed on the side opposite to the sunlight incident side of the solar cell power generation module. Polyesters such as polyethylene terephthalate (PET) usually have a large amount of carboxyl groups and hydroxyl groups on the surface thereof, are prone to hydrolysis in an environment where moisture exists, and tend to deteriorate over time. For this reason, polyesters used in solar cell power generation modules and the like that are constantly exposed to wind and rain such as outdoors are required to have particularly low hydrolyzability.
Further, same applies to the polyester to be applied to outdoor applications other than the solar cell power generation module applications, it is required to hydrolyzable is suppressed.
　ポリエステルに耐加水分解性を付与するには、加水分解反応の原因となる末端ＣＯＯＨを低減することが考えられる。ポリエステルの末端ＣＯＯＨの量、すなわち、末端ＣＯＯＨ濃度は、酸価（ＡＶ；Ａｃｉｄ　Ｖａｌｕｅ）により評価することができる。酸価の小さいポリエステルを重合し、フィルムに適用すれば、耐加水分解性を有するフィルムを製造し得る。
　ポリエステルの重合方法に関係して、例えば、所定の２つの関係式を満たす量のチタン化合物とリン化合物を含み、ポリエステルの末端ＣＯＯＨ濃度が４０当量／トン以下である太陽電池裏面封止用ポリエステルフィルムが開示されており、耐加水分解性や耐候性等の耐環境性が改良されるとされている（例えば、特開２００７－２０４５３８号公報参照）。 In order to impart hydrolysis resistance to the polyester, it is conceivable to reduce terminal COOH that causes hydrolysis reaction. The amount of terminal COOH of the polyester, that is, the concentration of terminal COOH, can be evaluated by an acid value (AV; Acid Value). If a polyester having a small acid value is polymerized and applied to a film, a film having hydrolysis resistance can be produced.
In relation to the polymerization method of polyester, for example, a polyester film for sealing a back surface of a solar cell, which contains a titanium compound and a phosphorus compound in amounts satisfying two predetermined relational expressions, and the terminal COOH concentration of the polyester is 40 equivalents / ton or less And environmental resistance such as hydrolysis resistance and weather resistance is improved (see, for example, JP-A-2007-204538).
　また、固相重合反応時のアセトアルデヒドやホルムアルデヒド等の副生成物の発生を抑制させるために、酸素濃度が３００ｐｐｍ以下の不活性ガス雰囲気下において、特定条件の下、固相重合する固相重合ポリエステルの製造方法が開示されている（例えば、特開２００９－０５２０４１号公報参照）。
　さらに、ＰＥＴ樹脂の結晶化のために、顆粒状のＰＥＴ樹脂を、高温ガスによって乾燥する方法が開示されている（例えば、特表２００１－５１９５２２号公報参照）。また、Ｈ．Ｚｉｍｍｅｒｍａｎ，Ｎ．Ｔ．　Ｋｉｍ，Ｐｏｌｙｍｅｒ　Ｅｎｇ．＆　Ｓｃｉ．，２０，６８０（１９８０）では、末端カルボキシ基量が低いほど、加水分解の反応速度が加速度的に減少することが、反応速度論を用いて示されている。 In addition, in order to suppress the generation of by-products such as acetaldehyde and formaldehyde during the solid phase polymerization reaction, solid phase polymerized polyester that undergoes solid phase polymerization under specific conditions in an inert gas atmosphere with an oxygen concentration of 300 ppm or less Is disclosed (for example, see Japanese Patent Application Laid-Open No. 2009-052041).
Furthermore, a method of drying granular PET resin with a high-temperature gas for crystallization of the PET resin has been disclosed (for example, see JP-T-2001-519522). H. Zimmerman, N .; T.A. Kim, Polymer Eng. & Sci. , 20, 680 (1980) shows that the lower the amount of terminal carboxy groups, the faster the hydrolysis reaction rate decreases.
　しかしながら、固相重合を用いて、低末端カルボキシ基量のポリエステル樹脂を合成することができても、特にポリエステルフィルムを製膜する際に、ポリエステルの分解が進行してしまい、結果的に、フィルムの末端カルボキシ基は、原料樹脂よりも高いことが、一般的である。また、製膜時の分解反応は、一様に起こるわけではないため、フィルムの長手方向で、末端カルボキシ基量が変動し、結果として、フィルムの耐候性にムラが生じてしまう。
　特に、特許文献１にあるような、末端カルボキシ基量が２０当量／トン以下のフィルムでは、カルボキシ基量のわずかな変動でも、耐候性が大きく変化してしまうことが問題であった。この問題は、末端カルボキシ基量の低下と共に、耐候性が加速度的に向上することに付随した、新たな問題である。 However, even if it is possible to synthesize a polyester resin having a low terminal carboxyl group amount using solid phase polymerization, degradation of the polyester proceeds particularly when a polyester film is formed. The terminal carboxy group is generally higher than the starting resin. In addition, since the decomposition reaction during film formation does not occur uniformly, the amount of terminal carboxy groups varies in the longitudinal direction of the film, resulting in unevenness in the weather resistance of the film.
In particular, a film having a terminal carboxy group amount of 20 equivalent / ton or less as disclosed in Patent Document 1 has a problem in that the weather resistance greatly changes even if the carboxy group amount slightly varies. This problem, together with the lowering of the terminal carboxy group amount, the weather resistance is associated with that acceleration improved, a new problem.
　本発明は、従来のポリエステルフィルムの製造方法に比べて、耐加水分解性のバラツキが抑制されたポリエステルフィルムを得るポリエステルフィルムの製造方法、耐加水分解性のバラツキが抑制された太陽電池用ポリエステルフィルム、及び、長期に亘り安定的な発電性能が得られる太陽電池発電モジュールを提供することを目的とし、該目的を達成することを課題とする。 The present invention relates to a method for producing a polyester film that obtains a polyester film in which variation in hydrolysis resistance is suppressed as compared with a conventional method for producing a polyester film, and a polyester film for solar cells in which variation in hydrolysis resistance is suppressed. And it aims at providing the solar cell power generation module which can obtain the stable power generation performance over a long period of time, and makes it a subject to achieve the object.
　前記課題を達成するための具体的手段は以下の通りである。
＜１＞　結晶化度分布Δρが３％＜Δρ≦１５％にあるポリエステルを、反応槽に供給して固相重合する固相重合工程と、
　前記固相重合されたポリエステルを、フィルム状に押出成形する押出成形工程と、
を有するポリエステルフィルムの製造方法である。 Specific means for achieving the above object are as follows.
<1> A solid-phase polymerization step in which a polyester having a crystallinity distribution Δρ of 3% <Δρ ≦ 15% is supplied to a reaction vessel and solid-phase polymerized;
An extrusion process for extruding the solid-phase polymerized polyester into a film; and
It is a manufacturing method of the polyester film which has this.
＜２＞　前記ポリエステルの結晶化度分布Δρが５％≦Δρ≦１３％にある前記＜１＞に記載のポリエステルフィルムの製造方法である。 <2> The method for producing a polyester film according to <1>, wherein the crystallinity distribution Δρ of the polyester is 5% ≦ Δρ ≦ 13%.
＜３＞　前記ポリエステルは、結晶子径分布ΔＤが１０％以下である前記＜１＞または前記＜２＞に記載のポリエステルフィルムの製造方法である。 <3> The polyester is a method for producing a polyester film according to <1> or <2>, wherein the crystallite size distribution ΔD is 10% or less.
＜４＞　前記ポリエステルは、結晶子径分布ΔＤが３％～９％である前記＜１＞～前記＜３＞のいずれか１つに記載のポリエステルフィルムの製造方法である。
＜５＞　前記固相重合工程の前に、前記ポリエステルに温熱ガスを供給し、供給された前記温熱ガスによって前記ポリエステルを加熱して結晶化する前記＜１＞～前記＜４＞のいずれか１つに記載のポリエステルフィルムの製造方法である。
＜６＞　前記温熱ガスの供給量〔Ｎｍ３／Ｋｇ〕が、前記ポリエステル１ｋｇに対して、０．１Ｎｍ３～１．５Ｎｍ３である前記＜５＞に記載のポリエステルフィルムの製造方法である。 <4> The method for producing a polyester film according to any one of <1> to <3>, wherein the polyester has a crystallite size distribution ΔD of 3% to 9%.
<5> Any one of the above <1> to <4>, wherein a hot gas is supplied to the polyester before the solid phase polymerization step, and the polyester is heated and crystallized by the supplied hot gas. It is a manufacturing method of the polyester film as described in one.
<6> supply amount of the thermal gas [Nm 3 / Kg] is, relative to the polyester 1 kg, is a method for producing a polyester film according to the a 0.1Nm 3 ~ 1.5Nm 3 <5> .
＜７＞　前記反応槽に入れるときの前記ポリエステルの温度が、１８０℃～２２０℃である前記＜１＞～前記＜６＞のいずれか１つに記載のポリエステルフィルムの製造方法である。
＜８＞　前記固相重合の時間が、５時間～１００時間である前記＜１＞～前記＜７＞のいずれか１つに記載のポリエステルフィルムの製造方法である。
＜９＞　前記固相重合前のポリエステルの結晶子径Ｄが８０Å～１２０Åである前記＜１＞～前記＜８＞のいずれか１つに記載のポリエステルフィルムの製造方法である。
＜１０＞　前記固相重合前のポリエステルの結晶化度ρが４７％～５８％である前記＜１＞～前記＜９＞のいずれか１つに記載のポリエステルフィルムの製造方法である。 <7> The method for producing a polyester film according to any one of <1> to <6>, wherein the temperature of the polyester when entering the reaction vessel is 180 ° C. to 220 ° C.
<8> The method for producing a polyester film according to any one of <1> to <7>, wherein the solid phase polymerization time is 5 hours to 100 hours.
<9> The method for producing a polyester film according to any one of <1> to <8>, wherein the crystallite diameter D of the polyester before solid phase polymerization is 80 to 120 mm.
<10> The method for producing a polyester film according to any one of <1> to <9>, wherein the crystallinity ρ of the polyester before the solid phase polymerization is 47% to 58%.
＜１１＞　前記＜１＞～前記＜１０＞のいずれか１つに記載のポリエステルフィルムの製造方法により製造された太陽電池用ポリエステルフィルムである。 <11> A solar cell polyester film produced by the method for producing a polyester film according to any one of <1> to <10>.
＜１２＞　長尺状の形状を有すると共に、末端ＣＯＯＨを少なくとも含み、長手方向における前記末端ＣＯＯＨの量のバラツキが２ｅｑ／ｔｏｎ未満である前記＜１１＞に記載の太陽電池用ポリエステルフィルムである。 <12> The solar cell polyester film according to <11>, which has a long shape and includes at least terminal COOH, and variation in the amount of the terminal COOH in the longitudinal direction is less than 2 eq / ton.
＜１３＞　太陽光が入射する透明性の基板と、太陽電池素子と、該太陽電池素子の前記基板が配される側と反対側に設けられた前記＜１１＞または前記＜１２＞に記載の太陽電池用ポリエステルフィルムを備えた太陽電池発電モジュールである。 <13> The transparent substrate on which sunlight is incident, the solar cell element, and the solar cell element according to <11> or <12> provided on the side opposite to the side on which the substrate is disposed. It is a solar cell power generation module provided with the polyester film for solar cells.
　本発明によれば、従来のポリエステルフィルムの製造方法に比べて、耐加水分解性のバラツキが抑制されたポリエステルフィルムを得るポリエステルフィルムの製造方法を提供することができる。また、
　本発明によれば、従来のポリエステルフィルムに比べて耐加水分解性のバラツキが抑制された太陽電池用ポリエステルフィルムを提供することができる。更に、
　本発明によれば、長期に亘り安定的な発電性能が得られる太陽電池発電モジュールを提供することができる。 ADVANTAGE OF THE INVENTION According to this invention, compared with the manufacturing method of the conventional polyester film, the manufacturing method of the polyester film which obtains the polyester film in which the variation in hydrolysis resistance was suppressed can be provided. Also,
ADVANTAGE OF THE INVENTION According to this invention, the polyester film for solar cells by which the variation in hydrolysis resistance was suppressed compared with the conventional polyester film can be provided. Furthermore,
ADVANTAGE OF THE INVENTION According to this invention, the solar cell power generation module from which stable power generation performance is obtained over a long term can be provided.
ポリエステルを温熱ガスにより加熱する結晶化装置の構成例を示す概略断面図である。It is a schematic sectional drawing which shows the structural example of the crystallization apparatus which heats polyester with warm gas. ポリエステルフィルムの末端ＣＯＯＨ量のバラツキの評価方法を説明するためのポリエステルフィルムの模式図である。It is a schematic diagram of the polyester film for demonstrating the evaluation method of the variation in the amount of terminal COOH of a polyester film.
　以下、本発明のポリエステルフィルムの製造方法、並びにこれを用いた太陽電池用ポリエステルフィルム及び太陽電池発電モジュールについて詳細に説明する。 Hereinafter, the polyester film production method of the present invention, and the solar cell polyester film and solar cell power generation module using the same will be described in detail.
＜ポリエステルフィルムの製造方法＞
　本発明のポリエステルフィルムの製造方法は、結晶化度分布Δρが３％＜Δρ≦１５％にあるポリエステルを、反応槽に供給して固相重合する固相重合工程と、前記固相重合されたポリエステルを、フィルム状に押出成形する押出成形工程と、を有するように構成されたものである。本発明のポリエステルフィルムの製造方法は、必要に応じて、さらに他の工程を有して構成されてもよい。 <Production method of polyester film>
The method for producing a polyester film according to the present invention includes a solid phase polymerization step in which a polyester having a crystallinity distribution Δρ of 3% <Δρ ≦ 15% is supplied to a reaction vessel and subjected to solid phase polymerization, and the solid phase polymerization is performed. And an extrusion process for extruding polyester into a film. The manufacturing method of the polyester film of this invention may have another process as needed, and may be comprised.
　ポリエステルフィルムの製造方法を上記構成とすることで、耐加水分解性のバラツキが抑制されたポリエステルフィルムを得ることができる。
　ポリエステルは、ポリエステルが末端カルボキシ基（末端ＣＯＯＨ）を有していることで、末端カルボキシ基（末端ＣＯＯＨ）が触媒となって、加水分解を生じ易い。ポリエステルが有する末端ＣＯＯＨの量は、ポリエステルの末端ＣＯＯＨ量（ＡＶ）の大きさにより確認することができ、末端ＣＯＯＨ量が小さいポリエステルほど、耐加水分解性に優れるといえる。 The method for producing a polyester film by the above-described construction, it is possible to obtain a polyester film hydrolysis resistance variation is suppressed.
Since polyester has a terminal carboxy group (terminal COOH), the terminal carboxy group (terminal COOH) serves as a catalyst and is easily hydrolyzed. The amount of terminal COOH contained in the polyester can be confirmed by the size of the terminal COOH amount (AV) of the polyester, and it can be said that the smaller the terminal COOH amount, the better the hydrolysis resistance.
　ポリエステルの末端ＣＯＯＨ量は、押出成形時等において、ポリエステルを加熱し、溶融するときに大きくなり易い。これは、ポリエステルが過熱状態におかれることで熱分解を起こし、末端ＣＯＯＨが生成するためと考えられる。ポリエステルの過熱は、押出機内でポリエステルを押出す圧力が変動すること（圧力変動）により生じ易いと考えられる。 The amount of terminal COOH of the polyester tends to increase when the polyester is heated and melted during extrusion molding or the like. This is considered to be because thermal decomposition occurs due to the polyester being overheated, and terminal COOH is generated. It is considered that polyester overheating is likely to occur due to fluctuations in pressure for extruding polyester in the extruder (pressure fluctuations).
　ここで、このような押出機内での圧力変動は、押出機に投入するポリエステルの結晶化度ρ〔％〕の分布（Δρ）が狭いときに発生し易く、結晶化度分布Δρが大きいときに、圧力変動を抑制し得ることを見出した。これは、滑剤による押出し負荷の低減効果と類似した現象と考えている。
　具体的には、結晶化度分布Δρが３％＜Δρ≦１５％にあるポリエステルを用いて押出成形をすることで、押出機内での圧力変動が抑制され、ポリエステルの末端ＣＯＯＨ量（ＡＶ）が小さくなると共に、ポリエステルをフィルム状に成形したときに、フィルムの位置によって末端ＣＯＯＨ量がばらつくことが抑制される。
　さらに、押出成形するポリエステルを固相重合することで、ポリエステルの末端ＣＯＯＨ量（酸価）、結晶化度ρ、固有粘度（Ｉｎｔｅｒｉｓｉｃ　Ｖｉｓｃｏｓｉｔｙ；ＩＶ）、含水率等を制御することができる。
　以下、本発明のポリエステルフィルムの製造方法について、詳細に説明する。 Here, such pressure fluctuations in the extruder are likely to occur when the distribution (Δρ) of the crystallinity ρ [%] of the polyester charged into the extruder is narrow, and when the crystallinity distribution Δρ is large. The inventors have found that pressure fluctuation can be suppressed. This is considered to be a phenomenon similar to the effect of reducing the extrusion load by the lubricant.
Specifically, by performing extrusion molding using a polyester having a crystallinity distribution Δρ of 3% <Δρ ≦ 15%, pressure fluctuation in the extruder is suppressed, and the terminal COOH amount (AV) of the polyester is reduced. with smaller, when molding the polyester into a film, the amount of terminal COOH can vary it is suppressed by the position of the film.
Furthermore, by subjecting the polyester to be extruded to solid phase polymerization, the terminal COOH amount (acid value), crystallinity ρ, intrinsic viscosity (IV), moisture content, and the like of the polyester can be controlled.
Hereinafter, the manufacturing method of the polyester film of this invention is demonstrated in detail.
〔固相重合工程〕
　固相重合工程では、結晶化度分布Δρが３％＜Δρ≦１５％にあるポリエステルを、反応槽に供給して固相重合する。 [Solid-state polymerization process]
In the solid phase polymerization step, a polyester having a crystallinity distribution Δρ of 3% <Δρ ≦ 15% is supplied to the reaction vessel and subjected to solid phase polymerization.
（ポリエステル）
　まず、ポリエステルについて説明する。
　ポリエステルの種類は特に制限されない。
　ジカルボン酸成分と、ジオール成分とを用いて合成してもよいし、市販のポリエステルを用いてもよい。 (polyester)
First, polyester will be described.
The kind of polyester is not particularly limited.
It may be synthesized using a dicarboxylic acid component and a diol component, or a commercially available polyester may be used.
　ポリエステルを合成する場合は、例えば、（Ａ）ジカルボン酸成分と、（Ｂ）ジオール成分とを、周知の方法でエステル化反応及び／又はエステル交換反応させることによって得ることができる。
　（Ａ）ジカルボン酸成分としては、例えば、マロン酸、コハク酸、グルタル酸、アジピン酸、スベリン酸、セバシン酸、ドデカンジオン酸、ダイマー酸、エイコサンジオン酸、ピメリン酸、アゼライン酸、メチルマロン酸、エチルマロン酸等の脂肪族ジカルボン酸類、アダマンタンジカルボン酸、ノルボルネンジカルボン酸、イソソルビド、シクロヘキサンジカルボン酸、デカリンジカルボン酸、などの脂環族ジカルボン酸、テレフタル酸、イソフタル酸、フタル酸、１，４－ナフタレンジカルボン酸、１，５－ナフタレンジカルボン酸、２，６－ナフタレンジカルボン酸、１，８－ナフタレンジカルボン酸、４，４’－ジフェニルジカルボン酸、４，４’－ジフェニルエーテルジカルボン酸、５－ナトリウムスルホイソフタル酸、フェニルエンダンジカルボン酸、アントラセンジカルボン酸、フェナントレンジカルボン、９，９’－ビス（４－カルボキシフェニル）フルオレン酸等の芳香族ジカルボン酸などのジカルボン酸もしくはそのエステル誘導体が挙げられる。 When the polyester is synthesized, for example, it can be obtained by subjecting (A) a dicarboxylic acid component and (B) a diol component to an esterification reaction and / or a transesterification reaction by a well-known method.
(A) Examples of the dicarboxylic acid component include malonic acid, succinic acid, glutaric acid, adipic acid, suberic acid, sebacic acid, dodecanedioic acid, dimer acid, eicosandioic acid, pimelic acid, azelaic acid, methylmalonic acid Aliphatic dicarboxylic acids such as ethylmalonic acid, adamantane dicarboxylic acid, norbornene dicarboxylic acid, isosorbide, cyclohexanedicarboxylic acid, decalin dicarboxylic acid, and the like, terephthalic acid, isophthalic acid, phthalic acid, 1,4- Naphthalene dicarboxylic acid, 1,5-naphthalene dicarboxylic acid, 2,6-naphthalene dicarboxylic acid, 1,8-naphthalene dicarboxylic acid, 4,4′-diphenyl dicarboxylic acid, 4,4′-diphenyl ether dicarboxylic acid, 5-sodium sulfo Isophthalic acid, phenyl ether Boy carboxylic acid, anthracene dicarboxylic acid, phenanthrene carboxylic, 9,9'-bis (4-carboxyphenyl) a dicarboxylic acid or its ester derivatives such as aromatic dicarboxylic acids such as fluorene acid.
（Ｂ）ジオール成分としては、例えば、エチレングリコール、１，２－プロパンジオール、１，３－プロパンジオール、１，４－ブタンジオール、１，２－ブタンジオール、１，３－ブタンジオール等の脂肪族ジオール類、シクロヘキサンジメタノール、スピログリコール、イソソルビドなどの脂環式ジオール類、ビスフェノールＡ、１，３―ベンゼンジメタノール，１，４－ベンセンジメタノール、９，９’－ビス（４－ヒドロキシフェニル）フルオレン、などの芳香族ジオール類等のジオール化合物が挙げられる。 (B) Examples of the diol component include fats such as ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,2-butanediol, and 1,3-butanediol. Diols, cycloaliphatic dimethanol, spiroglycol, isosorbide and other alicyclic diols, bisphenol A, 1,3-benzenedimethanol, 1,4-benzenedimethanol, 9,9'-bis (4-hydroxyphenyl) ) Diol compounds such as aromatic diols such as fluorene.
　（Ａ）ジカルボン酸成分として、芳香族ジカルボン酸の少なくとも１種が用いられる場合が好ましい。より好ましくは、ジカルボン酸成分のうち、芳香族ジカルボン酸を主成分として含有する。なお、「主成分」とは、ジカルボン酸成分に占める芳香族ジカルボン酸の割合が８０％以上であることをいう。芳香族ジカルボン酸以外のジカルボン酸成分を含んでもよい。このようなジカルボン酸成分としては、芳香族ジカルボン酸などのエステル誘導体等である。
　また、（Ｂ）ジオール成分として、脂肪族ジオールの少なくとも１種が用いられる場合が好ましい。脂肪族ジオールとして、エチレングリコールを含むことができ、好ましくはエチレングリコールを主成分として含有する。なお、主成分とは、ジオール成分に占めるエチレングリコールの割合が８０％以上であることをいう。 (A) As a dicarboxylic acid component, the case where at least 1 sort of aromatic dicarboxylic acid is used is preferable. More preferably, the dicarboxylic acid component contains an aromatic dicarboxylic acid as a main component. Here, the "main component" refers to the proportion of the aromatic dicarboxylic acid in the dicarboxylic acid component is 80% or more. A dicarboxylic acid component other than the aromatic dicarboxylic acid may be included. Examples of such a dicarboxylic acid component include ester derivatives such as aromatic dicarboxylic acids.
Moreover, it is preferable that at least one aliphatic diol is used as the (B) diol component. The aliphatic diol can contain ethylene glycol, and preferably contains ethylene glycol as a main component. The main component means that the proportion of ethylene glycol in the diol component is 80% or more.
　脂肪族ジオール（例えばエチレングリコール）の使用量は、前記芳香族ジカルボン酸（例えばテレフタル酸）及び必要に応じそのエステル誘導体の１モルに対して、１．０１５モル～１．５０モルの範囲であるのが好ましい。該使用量は、より好ましくは１．０２モル～１．３０モルの範囲であり、更に好ましくは１．０２５モル～１．１０モルの範囲である。該使用量は、１．０１５以上の範囲であると、エステル化反応が良好に進行し、１．５０モル以下の範囲であると、例えばエチレングリコールの２量化によるジエチレングリコールの副生が抑えられ、融点やガラス転移温度、結晶性、耐熱性、耐加水分解性、耐候性など多くの特性を良好に保つことができる。 The amount of the aliphatic diol (eg, ethylene glycol) used is in the range of 1.015 mol to 1.50 mol with respect to 1 mol of the aromatic dicarboxylic acid (eg, terephthalic acid) and, if necessary, its ester derivative. Is preferred. The amount used is more preferably in the range of 1.02 mol to 1.30 mol, and still more preferably in the range of 1.025 mol to 1.10 mol. If the amount used is in the range of 1.015 or more, the esterification reaction proceeds favorably, and if it is in the range of 1.50 mol or less, for example, by-production of diethylene glycol due to dimerization of ethylene glycol is suppressed, Many characteristics such as melting point, glass transition temperature, crystallinity, heat resistance, hydrolysis resistance, and weather resistance can be kept good.
　エステル化反応及び／又はエステル交換反応には、従来から公知の反応触媒を用いることができる。該反応触媒としては、アルカリ金属化合物、アルカリ土類金属化合物、亜鉛化合物、鉛化合物、マンガン化合物、コバルト化合物、アルミニウム化合物、アンチモン化合物、チタン化合物、リン化合物などを挙げることができる。通常、ポリエステルの製造方法が完結する以前の任意の段階において、重合触媒としてアンチモン化合物、ゲルマニウム化合物、又はチタン化合物を添加することが好ましい。このような方法としては、例えば、ゲルマニウム化合物を例に取ると、ゲルマニウム化合物粉体をそのまま添加することが好ましい。 A conventionally known reaction catalyst can be used for the esterification reaction and / or the transesterification reaction. Examples of the reaction catalyst include alkali metal compounds, alkaline earth metal compounds, zinc compounds, lead compounds, manganese compounds, cobalt compounds, aluminum compounds, antimony compounds, titanium compounds, and phosphorus compounds. Usually, it is preferable to add an antimony compound, a germanium compound, or a titanium compound as a polymerization catalyst at an arbitrary stage before the polyester production method is completed. As such a method, for example, when a germanium compound is taken as an example, it is preferable to add the germanium compound powder as it is.
　例えば、エステル化反応工程は、芳香族ジカルボン酸と脂肪族ジオールとを、チタン化合物を含有する触媒の存在下で重合する。このエステル化反応工程では、触媒であるチタン化合物として、有機酸を配位子とする有機キレートチタン錯体を用いると共に、工程中に少なくとも、有機キレートチタン錯体と、マグネシウム化合物と、置換基として芳香環を有しない５価のリン酸エステルとをこの順序で添加する過程を設けて構成される。 For example, in the esterification reaction step, an aromatic dicarboxylic acid and an aliphatic diol are polymerized in the presence of a catalyst containing a titanium compound. In this esterification reaction step, an organic chelate titanium complex having an organic acid as a ligand is used as a catalyst titanium compound, and at least an organic chelate titanium complex, a magnesium compound, and an aromatic ring as a substituent in the step. And a process of adding a pentavalent phosphate ester having no sulfite in this order.
　まず初めに、芳香族ジカルボン酸及び脂肪族ジオールを、マグネシウム化合物及びリン化合物の添加に先立って、チタン化合物である有機キレートチタン錯体を含有する触媒と混合する。有機キレートチタン錯体等のチタン化合物は、エステル化反応に対しても高い触媒活性を持つので、エステル化反応を良好に行なわせることができる。このとき、ジカルボン酸成分及びジオール成分を混合した中にチタン化合物を加えてもよいし、ジカルボン酸成分（又はジオール成分）とチタン化合物を混合してからジオール成分（又はジカルボン酸成分）を混合してもよい。また、ジカルボン酸成分とジオール成分とチタン化合物とを同時に混合するようにしてもよい。混合は、その方法に特に制限はなく、従来公知の方法により行なうことが可能である。 First, an aromatic dicarboxylic acid and an aliphatic diol are mixed with a catalyst containing an organic chelate titanium complex, which is a titanium compound, prior to addition of a magnesium compound and a phosphorus compound. Titanium compounds such as organic chelate titanium complexes have high catalytic activity for esterification reactions, so that esterification reactions can be performed satisfactorily. At this time, the titanium compound may be added to the mixture of the dicarboxylic acid component and the diol component, or after mixing the dicarboxylic acid component (or diol component) and the titanium compound, the diol component (or dicarboxylic acid component) is mixed. May be. Further, the dicarboxylic acid component, the diol component, and the titanium compound may be mixed at the same time. The mixing is not particularly limited, and can be performed by a conventionally known method.
　より好ましいポリエステルは、ポリエチレンテレフタレート（ＰＥＴ）、ポリエチレン－２，６－ナフタレート（ＰＥＮ）であり、さらに好ましいのはＰＥＴである。さらに、ＰＥＴは、触媒成分としてゲルマニウム（Ｇｅ）化合物（Ｇｅ系触媒）、アンチモン（Ｓｂ）化合物（Ｓｂ系触媒）、アルミニウム（Ａｌ）化合物（Ａｌ系触媒）、及びチタン（Ｔｉ）化合物（Ｔｉ系触媒）から選ばれる１種又は２種以上を用いて重合されるものが好ましく、より好ましくはチタン化合物（但し、酸化チタンを除く）である。 More preferred polyesters are polyethylene terephthalate (PET) and polyethylene-2,6-naphthalate (PEN), and more preferred is PET. Further, PET has a germanium (Ge) compound (Ge-based catalyst), an antimony (Sb) compound (Sb-based catalyst), an aluminum (Al) compound (Al-based catalyst), and a titanium (Ti) compound (Ti-based catalyst) as catalyst components. Those which are polymerized using one or more selected from (catalyst) are preferred, and titanium compounds (excluding titanium oxide) are more preferred.
　前記チタン化合物は、反応活性が高く、重合温度を低くすることができる。そのため、特に重合反応中にポリエステルが熱分解し、ＣＯＯＨが発生するのを抑制することが可能である。すなわち、チタン化合物を用いることで、熱分解の原因となるポリエステルの末端カルボン酸の量を低減することができ、異物形成を抑制することができる。ポリエステルの末端カルボン酸の量を低減しておくことで、ポリエステルフィルムを製造した後に、ポリエステルフィルムが熱分解することを抑制することもできる。
　なお、チタン化合物の中でも、白色化剤として使用する酸化チタンではこのような効果は得られない。 The titanium compound has high reaction activity and can lower the polymerization temperature. Therefore, it is possible to suppress the polyester from being thermally decomposed during the polymerization reaction and generating COOH. That is, by using a titanium compound, the amount of terminal carboxylic acid of polyester that causes thermal decomposition can be reduced, and foreign matter formation can be suppressed. By reducing the amount of the terminal carboxylic acid of the polyester, it is possible to suppress thermal decomposition of the polyester film after the production of the polyester film.
Of the titanium compounds, titanium oxide used as a whitening agent cannot provide such an effect.
［チタン系触媒］
　触媒として用いられるチタン化合物、すなわち、チタン系触媒は、有機酸を配位子とする有機キレートチタン錯体の少なくとも１種であることが好ましい。有機酸としては、例えば、クエン酸、乳酸、トリメリット酸、リンゴ酸等を挙げることができる。中でも、クエン酸又はクエン酸塩を配位子とする有機キレート錯体が好ましい。 [Titanium catalyst]
The titanium compound used as the catalyst, that is, the titanium-based catalyst is preferably at least one of organic chelate titanium complexes having an organic acid as a ligand. Examples of the organic acid include citric acid, lactic acid, trimellitic acid, malic acid and the like. Among them, an organic chelate complex having citric acid or citrate as a ligand is preferable.
　例えばクエン酸を配位子とするキレートチタン錯体を用いた場合、微細粒子等の異物の発生が少なく、他のチタン化合物に比べ、重合活性と色調の良好なポリエステルが得られる。更に、クエン酸キレートチタン錯体を用いる場合でも、エステル化反応の段階で添加する方法により、エステル化反応後に添加する場合に比べ、重合活性と色調が良好で、末端カルボキシル基の少ないポリエステルが得られる。この点については、チタン系触媒はエステル化反応の触媒効果もあり、エステル化段階で添加することでエステル化反応終了時におけるオリゴマー酸価が低くなり、以降の重縮合反応がより効率的に行なわれ、またクエン酸を配位子とする錯体はチタンアルコキシド等に比べて加水分解耐性が高く、エステル化反応過程において加水分解せず、本来の活性を維持したままエステル化及び重縮合反応の触媒として効果的に機能するものと推定される。
　また、一般に、末端カルボキシル基量が多いほど耐加水分解性が悪化することが知られており、上記の添加方法によって末端カルボキシル基量が少なくなることで、耐加水分解性の向上が期待される。 For example, when a chelate titanium complex having citric acid as a ligand is used, there is little generation of foreign matters such as fine particles, and a polyester having good polymerization activity and color tone can be obtained as compared with other titanium compounds. Furthermore, even when a citric acid chelate titanium complex is used, a method of adding at the stage of esterification reaction gives a polyester having better polymerization activity and color tone and less terminal carboxyl groups than when added after the esterification reaction. . In this regard, the titanium-based catalyst also has a catalytic effect on the esterification reaction. By adding it at the esterification stage, the oligomer acid value at the end of the esterification reaction is lowered, and the subsequent polycondensation reaction is performed more efficiently. In addition, complexes with citric acid as a ligand are more resistant to hydrolysis than titanium alkoxides, etc., and do not hydrolyze in the esterification reaction process, while maintaining the original activity and catalyzing esterification and polycondensation reactions. It is estimated to function effectively as
In general, it is known that hydrolysis resistance deteriorates as the amount of terminal carboxyl groups increases, and the hydrolysis resistance is expected to be improved by decreasing the amount of terminal carboxyl groups by the above addition method. .
　前記クエン酸キレートチタン錯体としては、例えば、ジョンソン・マッセイ社製のＶＥＲＴＥＣ ＡＣ－４２０など市販品として容易に入手可能である。 As the citrate chelate titanium complex, for example, VERTEC® AC-420 manufactured by Johnson Matthey can be easily obtained as a commercial product.
　芳香族ジカルボン酸と脂肪族ジオールは、これらが含まれたスラリーを調製し、これをエステル化反応工程に連続的に供給することにより導入することができる。 The aromatic dicarboxylic acid and the aliphatic diol can be introduced by preparing a slurry containing them and continuously supplying it to the esterification reaction step.
　また、チタン化合物としては、有機キレートチタン錯体以外には一般に、酸化物、水酸化物、アルコキシド、カルボン酸塩、炭酸塩、蓚酸塩、及びハロゲン化物等が挙げられる。本発明の効果を損なわない範囲であれば、有機キレートチタン錯体に加えて、他のチタン化合物を併用してもよい。
　このようなチタン化合物の例としては、テトラ－ｎ－プロピルチタネート、テトラ－ｉ－プロピルチタネート、テトラ－ｎ－ブチルチタネート、テトラ－ｎ－ブチルチタネートテトラマー、テトラ－ｔ－ブチルチタネート、テトラシクロヘキシルチタネート、テトラフェニルチタネート、テトラベンジルチタネート等のチタンアルコキシド、チタンアルコキシドの加水分解により得られるチタン酸化物、チタンアルコキシドと珪素アルコキシドもしくはジルコニウムアルコキシドとの混合物の加水分解により得られるチタン－珪素もしくはジルコニウム複合酸化物、酢酸チタン、蓚酸チタン、蓚酸チタンカリウム、蓚酸チタンナトリウム、チタン酸カリウム、チタン酸ナトリウム、チタン酸－水酸化アルミニウム混合物、塩化チタン、塩化チタン－塩化アルミニウム混合物、チタンアセチルアセトナート等が挙げられる。 In addition to the organic chelate titanium complex, titanium compounds generally include oxides, hydroxides, alkoxides, carboxylates, carbonates, oxalates, and halides. Other titanium compounds may be used in combination with the organic chelate titanium complex as long as the effects of the present invention are not impaired.
Examples of such titanium compounds include tetra-n-propyl titanate, tetra-i-propyl titanate, tetra-n-butyl titanate, tetra-n-butyl titanate tetramer, tetra-t-butyl titanate, tetracyclohexyl titanate, Titanium alkoxide such as tetraphenyl titanate, tetrabenzyl titanate, titanium oxide obtained by hydrolysis of titanium alkoxide, titanium-silicon or zirconium composite oxide obtained by hydrolysis of a mixture of titanium alkoxide and silicon alkoxide or zirconium alkoxide, Titanium acetate, titanium oxalate, potassium potassium oxalate, sodium titanium oxalate, potassium titanate, sodium titanate, titanium titanate-aluminum hydroxide mixture, titanium chloride, titanium chloride Down - aluminum chloride mixture, and titanium acetylacetonate.
　ポリエステルの重合する際には、チタン化合物（チタン系触媒を含む）を、チタン元素換算で、１ｐｐｍ～５０ｐｐｍ、より好ましくは２ｐｐｍ～３０ｐｐｍ、さらに好ましくは３ｐｐｍ～１５ｐｐｍの範囲で用いることが好ましい。この場合、原料ポリエステルには、１ｐｐｍ～５０ｐｐｍのチタン元素が含まれる。
　原料ポリエステルに含まれるチタン化合物（チタン系触媒を含む）の量が、チタン元素換算で１ｐｐｍよりも少ないと、ポリエステルの重量平均分子量（Ｍｗ）を上げることができず、熱分解し易いため、押出機内で異物が増加し易く、好ましくない。原料ポリエステルに含まれるチタン化合物（チタン系触媒を含む）の量がチタン元素換算で５０ｐｐｍｍを超えると、チタン化合物（チタン系触媒を含む）が異物となり、ポリエステルシートの延伸の際に、延伸むらを引き起こすため、好ましくない。 When the polyester is polymerized, it is preferable to use a titanium compound (including a titanium-based catalyst) in a range of 1 ppm to 50 ppm, more preferably 2 ppm to 30 ppm, and still more preferably 3 ppm to 15 ppm in terms of titanium element. In this case, the raw material polyester contains 1 ppm to 50 ppm of titanium element.
If the amount of the titanium compound (including the titanium-based catalyst) contained in the raw material polyester is less than 1 ppm in terms of titanium element, the weight average molecular weight (Mw) of the polyester cannot be increased, and it is easy to thermally decompose. Foreign matter tends to increase in the machine, which is not preferable. If the amount of the titanium compound (including the titanium-based catalyst) contained in the raw material polyester exceeds 50 ppmm in terms of titanium element, the titanium compound (including the titanium-based catalyst) becomes a foreign substance, and uneven stretching occurs when the polyester sheet is stretched. Because it causes, it is not preferable.
　本発明においては、芳香族ジカルボン酸と脂肪族ジオールとを、チタン化合物を含有する触媒の存在下で重合するとともに、チタン化合物の少なくとも一種が有機酸を配位子とする有機キレートチタン錯体であって、有機キレートチタン錯体とマグネシウム化合物と置換基として芳香環を有しない５価のリン酸エステルとをこの順序で添加する過程を少なくとも含むエステル化反応工程と、エステル化反応工程で生成されたエステル化反応生成物を重縮合反応させて重縮合物を生成する重縮合工程と、を設けて構成されているポリエステルの製造方法により作製されるのが好ましい。 In the present invention, an aromatic dicarboxylic acid and an aliphatic diol are polymerized in the presence of a catalyst containing a titanium compound, and at least one of the titanium compounds is an organic chelate titanium complex having an organic acid as a ligand. An esterification reaction step including at least a step of adding an organic chelate titanium complex, a magnesium compound, and a pentavalent phosphate ester having no aromatic ring as a substituent in this order, and an ester formed in the esterification reaction step And a polycondensation step in which a polycondensation product is produced by a polycondensation reaction of the chemical reaction product, and is preferably produced by a polyester production method.
　この場合、エステル化反応の過程において、チタン化合物として有機キレートチタン錯体を存在させた中に、マグネシウム化合物を添加し、次いで特定の５価のリン化合物を添加する添加順とすることで、チタン系触媒の反応活性を適度に高く保ち、マグネシウムによる静電印加特性を付与しつつ、かつ重縮合における分解反応を効果的に抑制することができるため、結果として着色が少なく、高い静電印加特性を有するとともに高温下に曝された際の黄変色が改善されたポリエステルが得られる。
　これにより、重合時の着色及びその後の溶融製膜時における着色が少なくなり、従来のアンチモン（Ｓｂ）触媒系のポリエステルに比べて黄色味が軽減され、また、透明性の比較的高いゲルマニウム触媒系のポリエステルに比べて遜色のない色調、透明性を持ち、しかも耐熱性に優れたポリエステルを提供できる。また、コバルト化合物や色素などの色調調整材を用いずに高い透明性を有し、黄色味の少ないポリエステルが得られる。 In this case, in the course of the esterification reaction, the addition of a magnesium compound to the presence of an organic chelate titanium complex as a titanium compound, followed by the addition order of adding a specific pentavalent phosphorus compound, thereby adding a titanium series. Since the reaction activity of the catalyst is kept moderately high, the electrostatic application characteristics due to magnesium can be imparted, and the decomposition reaction in the polycondensation can be effectively suppressed, resulting in less coloring and high electrostatic application characteristics. A polyester with improved yellowing when exposed to high temperatures is obtained.
As a result, coloring during polymerization and subsequent coloring during melt film formation are reduced, yellowness is reduced as compared with conventional antimony (Sb) catalyst-based polyester, and germanium catalyst system with relatively high transparency. Compared with other polyesters, it is possible to provide polyesters that have a color tone and transparency that are inferior to those of other polyesters and that have excellent heat resistance. Moreover, polyester which has high transparency and few yellowishness is obtained, without using color tone adjusting materials, such as a cobalt compound and a pigment | dye.
　このポリエステルは、透明性に関する要求の高い用途（例えば、光学用フィルム、工業用リス等）に利用が可能であり、高価なゲルマニウム系触媒を用いる必要がないため、大幅なコスト低減が図れる。加えて、Ｓｂ触媒系で生じやすい触媒起因の異物の混入も回避されるため、製膜過程での故障の発生や品質不良が軽減され、得率向上による低コスト化も図ることができる。 This polyester can be used for applications requiring high transparency (for example, optical film, industrial squirrel, etc.), and it is not necessary to use an expensive germanium-based catalyst, so that the cost can be greatly reduced. In addition, since the foreign material-prone catalyst caused by Sb catalyst systems are avoided, it is generated and quality defects reduce failure at the film formation process, it is possible to achieve even lower cost by yield ratio improvement.
　エステル化反応させるにあたり、チタン化合物である有機キレートチタン錯体と添加剤としてマグネシウム化合物と５価のリン化合物とをこの順に添加する過程を設ける。このとき、有機キレートチタン錯体の存在下、エステル化反応を進め、その後はマグネシウム化合物の添加を、リン化合物の添加前に開始する。 In the esterification reaction, a process of adding an organic chelate titanium complex which is a titanium compound and a magnesium compound and a pentavalent phosphorus compound as additives in this order is provided. At this time, the esterification reaction proceeds in the presence of the organic chelate titanium complex, and thereafter, the addition of the magnesium compound is started before the addition of the phosphorus compound.
［リン化合物］
　５価のリン化合物として、置換基として芳香環を有しない５価のリン酸エステルの少なくとも一種が用いられる。例えば、炭素数２以下の低級アルキル基を置換基として有するリン酸エステル〔（ＯＲ）３－Ｐ＝Ｏ；Ｒ＝炭素数１又は２のアルキル基〕が挙げられ、具体的には、リン酸トリメチル、リン酸トリエチルが特に好ましい。 [Phosphorus compounds]
As the pentavalent phosphorus compound, at least one pentavalent phosphate having no aromatic ring as a substituent is used. For example, phosphoric acid esters having a lower alkyl group having 2 or less carbon atoms as a substituent [(OR) 3 —P═O; R = an alkyl group having 1 or 2 carbon atoms], specifically, phosphoric acid Trimethyl and triethyl phosphate are particularly preferable.
　リン化合物の添加量としては、Ｐ元素換算値が５０ｐｐｍ～９０ｐｐｍの範囲となる量が好ましく、より好ましくは６０ｐｐｍ～８０ｐｐｍとなる量であり、さらに好ましくは６０ｐｐｍ～７５ｐｐｍとなる量である。 The addition amount of the phosphorus compound is preferably an amount such that the P element conversion value is in the range of 50 ppm to 90 ppm, more preferably 60 ppm to 80 ppm, and still more preferably 60 ppm to 75 ppm.
［マグネシウム化合物］
　ポリエステルにマグネシウム化合物を含めることにより、ポリエステルの静電印加性が向上する。この場合に着色がおきやすいが、本発明においては、着色を抑え、優れた色調、耐熱性が得られる。
　マグネシウム化合物としては、例えば、酸化マグネシウム、水酸化マグネシウム、マグネシウムアルコキシド、酢酸マグネシウム、炭酸マグネシウム等のマグネシウム塩が挙げられる。中でも、エチレングリコールへの溶解性の観点から、酢酸マグネシウムが最も好ましい。 [Magnesium compound]
By including a magnesium compound in the polyester, the electrostatic applicability of the polyester is improved. In this case, although it is easy to color, in this invention, coloring is suppressed and the outstanding color tone and heat resistance are obtained.
Examples of the magnesium compound include magnesium salts such as magnesium oxide, magnesium hydroxide, magnesium alkoxide, magnesium acetate, and magnesium carbonate. Among these, magnesium acetate is most preferable from the viewpoint of solubility in ethylene glycol.
　マグネシウム化合物の添加量としては、高い静電印加性を付与するためには、Ｍｇ元素換算値が５０ｐｐｍ以上となる量が好ましく、５０ｐｐｍ～１００ｐｐｍの範囲となる量がより好ましい。マグネシウム化合物の添加量は、静電印加性の付与の点で、好ましくは６０ｐｐｍ～９０ｐｐｍの範囲となる量であり、さらに好ましくは７０ｐｐｍ～８０ｐｐｍの範囲となる量である。 The amount of magnesium compound added is preferably such that the Mg element conversion value is 50 ppm or more, more preferably in the range of 50 ppm to 100 ppm, in order to impart high electrostatic applicability. The addition amount of the magnesium compound is preferably an amount in the range of 60 ppm to 90 ppm, more preferably an amount in the range of 70 ppm to 80 ppm, from the viewpoint of imparting electrostatic applicability.
　エステル化反応工程においては、触媒成分である前記チタン化合物と、添加剤である前記マグネシウム化合物及びリン化合物とを、下記式（ｉ）から算出される値Ｚが下記の関係式（ii）を満たすように、添加して溶融重合させる場合が特に好ましい。ここで、Ｐ含有量は芳香環を有しない５価のリン酸エステルを含むリン化合物全体に由来するリン量であり、Ｔｉ含有量は、有機キレートチタン錯体を含むＴｉ化合物全体に由来するチタン量である。このように、チタン化合物を含む触媒系でのマグネシウム化合物及びリン化合物の併用を選択し、その添加タイミング及び添加割合を制御することによって、チタン化合物の触媒活性を適度に高く維持しつつも、黄色味の少ない色調が得られ、重合反応時やその後の製膜時（溶融時）などで高温下に曝されても黄着色を生じ難い耐熱性を付与することができる。
　（ｉ）Ｚ＝５×（Ｐ含有量［ｐｐｍ］／Ｐ原子量）－２×（Ｍｇ含有量［ｐｐｍ］／Ｍｇ原子量）－４×（Ｔｉ含有量［ｐｐｍ］／Ｔｉ原子量）
　（ii）０≦Ｚ≦５．０
　これは、リン化合物はチタンに作用のみならずマグネシウム化合物とも相互作用することから、３者のバランスを定量的に表現する指標となるものである。
　前記式（ｉ）は、反応可能な全リン量から、マグネシウムに作用するリン分を除き、チタンに作用可能なリンの量を表現したものである。値Ｚが正の場合は、チタンを阻害するリンが余剰な状況にあり、逆に負の場合はチタンを阻害するために必要なリンが不足する状況にあるといえる。また、値Ｚが５．０を超える、つまりチタンに作用するリン量が多過ぎると、得られるポリエステルの耐熱性及び色調は良好なものの、触媒活性が低下しすぎ、生成性に劣る。反応においては、Ｔｉ、Ｍｇ、Ｐの各原子１個は等価ではないことから、式中の各々のモル数に価数を乗じて重み付けを施してある。 In the esterification reaction step, the value Z calculated from the following formula (i) for the titanium compound as the catalyst component and the magnesium compound and phosphorus compound as the additive satisfies the following relational expression (ii). Thus, the case where it is added and melt polymerized is particularly preferred. Here, the P content is the amount of phosphorus derived from the entire phosphorus compound including the pentavalent phosphate ester having no aromatic ring, and the Ti content is the amount of titanium derived from the entire Ti compound including the organic chelate titanium complex. It is. As described above, by selecting the combined use of the magnesium compound and the phosphorus compound in the catalyst system containing the titanium compound and controlling the addition timing and the addition ratio, while maintaining the catalyst activity of the titanium compound moderately high, yellow A color tone with less taste can be obtained, and heat resistance that hardly causes yellowing can be imparted even when exposed to high temperatures during polymerization reaction or subsequent film formation (during melting).
(I) Z = 5 × (P content [ppm] / P atomic weight) −2 × (Mg content [ppm] / Mg atomic weight) −4 × (Ti content [ppm] / Ti atomic weight)
(Ii) 0 ≦ Z ≦ 5.0
This is an index for quantitatively expressing the balance between the three because the phosphorus compound interacts not only with titanium but also with the magnesium compound.
The formula (i) expresses the amount of phosphorus that can act on titanium by excluding the phosphorus content that acts on magnesium from the total amount of phosphorus that can be reacted. When the value Z is positive, it can be said that there is an excess of phosphorus that inhibits titanium, and conversely, when it is negative, there is a shortage of phosphorus necessary to inhibit titanium. On the other hand, if the value Z exceeds 5.0, that is, the amount of phosphorus acting on titanium is too large, the resulting polyester has good heat resistance and color tone, but the catalytic activity is too low and the productivity is poor. In the reaction, since each atom of Ti, Mg, and P is not equivalent, each mole number in the formula is weighted by multiplying by a valence.
　本発明においては、特殊な合成等が不要であり、安価でかつ容易に入手可能なチタン化合物、リン化合物、マグネシウム化合物を用いて、反応に必要とされる反応活性を持ちながら、色調及び熱に対する着色耐性に優れたポリエステルを得ることができる。 In the present invention, no special synthesis or the like is required, and the titanium compound, phosphorus compound, and magnesium compound, which are inexpensive and easily available, are used for color tone and heat while having the reaction activity required for the reaction. A polyester excellent in coloring resistance can be obtained.
　前記式（ii）において、重合反応性を保った状態で、色調及び熱に対する着色耐性をより高める観点から、１．０≦Ｚ≦４．０を満たす場合が好ましく、１．５≦Ｚ≦３．０を満たす場合がより好ましい。 In the formula (ii), it is preferable that 1.0 ≦ Z ≦ 4.0 is satisfied and 1.5 ≦ Z ≦ 3 from the viewpoint of further increasing the color tone and the coloration resistance to heat while maintaining the polymerization reactivity. Is more preferable.
　本発明における好ましい態様として、エステル化反応が終了する前に、芳香族ジカルボン酸及び脂肪族ジオールに、１ｐｐｍ～３０ｐｐｍのクエン酸又はクエン酸塩を配位子とするキレートチタン錯体を添加後、該キレートチタン錯体の存在下に、６０ｐｐｍ～９０ｐｐｍ（より好ましくは７０ｐｐｍ～８０ｐｐｍ）の弱酸のマグネシウム塩を添加し、該添加後にさらに、５０ｐｐｍ～９０ｐｐｍ（より好ましくは６０ｐｐｍ～７５ｐｐｍ）の、芳香環を置換基として有しない５価のリン酸エステルを添加する態様が挙げられる。 As a preferred embodiment of the present invention, before the esterification reaction is completed, after adding a chelate titanium complex having 1 ppm to 30 ppm of citric acid or citrate as a ligand to the aromatic dicarboxylic acid and the aliphatic diol, In the presence of the chelate titanium complex, 60 ppm to 90 ppm (more preferably 70 ppm to 80 ppm) of a weak acid magnesium salt is added, and after the addition, 50 ppm to 90 ppm (more preferably 60 ppm to 75 ppm) of the aromatic ring is replaced. The aspect which adds the pentavalent phosphate which does not have as a group is mentioned.
　エステル化反応は、少なくとも２個の反応器を直列に連結した多段式装置を用いて、エチレングリコールが還流する条件下で、反応によって生成した水又はアルコールを系外に除去しながら実施することができる。 The esterification reaction may be carried out using a multistage apparatus in which at least two reactors are connected in series under conditions where ethylene glycol is refluxed while removing water or alcohol produced by the reaction from the system. it can.
　また、上記したエステル化反応は、一段階で行なってもよいし、多段階に分けて行なうようにしてもよい。
　エステル化反応を一段階で行なう場合、エステル化反応温度は２３０℃～２６０℃が好ましく、２４０℃～２５０℃がより好ましい。
　エステル化反応を多段階に分けて行なう場合、第一反応槽のエステル化反応の温度は２３０℃～２６０℃が好ましく、より好ましくは２４０℃～２５０℃であり、圧力は１．０ｋｇ／ｃｍ２～５．０ｋｇ／ｃｍ２が好ましく、より好ましくは２．０ｋｇ／ｃｍ２～３．０ｋｇ／ｃｍ２である。第二反応槽のエステル化反応の温度は２３０℃～２６０℃が好ましく、より好ましくは２４５℃～２５５℃であり、圧力は０．５ｋｇ／ｃｍ２～５．０ｋｇ／ｃｍ２、より好ましくは１．０ｋｇ／ｃｍ２～３．０ｋｇ／ｃｍ２である。さらに３段階以上に分けて実施する場合は、中間段階のエステル化反応の条件は、前記第一反応槽と最終反応槽の間の条件に設定するのが好ましい。 The esterification reaction described above may be performed in one stage or may be performed in multiple stages.
When the esterification reaction is carried out in one step, the esterification reaction temperature is preferably 230 ° C to 260 ° C, more preferably 240 ° C to 250 ° C.
When the esterification reaction is performed in multiple stages, the temperature of the esterification reaction in the first reaction tank is preferably 230 ° C. to 260 ° C., more preferably 240 ° C. to 250 ° C., and the pressure is 1.0 kg / cm 2. It is preferably ˜5.0 kg / cm 2 , more preferably 2.0 kg / cm 2 to 3.0 kg / cm 2 . The temperature of the esterification reaction in the second reaction tank is preferably 230 ° C. to 260 ° C., more preferably 245 ° C. to 255 ° C., and the pressure is 0.5 kg / cm 2 to 5.0 kg / cm 2 , more preferably 1 0.0 kg / cm 2 to 3.0 kg / cm 2 . Furthermore, when carrying out by dividing into three or more stages, it is preferable to set the conditions for the esterification reaction in the intermediate stage to the conditions between the first reaction tank and the final reaction tank.
－重縮合－
　重縮合は、エステル化反応で生成されたエステル化反応生成物を重縮合反応させて重縮合物を生成する。重縮合反応は、１段階で行なってもよいし、多段階に分けて行なうようにしてもよい。 -Polycondensation-
In polycondensation, a polycondensation product is produced by subjecting an esterification reaction product produced by the esterification reaction to a polycondensation reaction. The polycondensation reaction may be performed in one stage or may be performed in multiple stages.
　エステル化反応で生成したオリゴマー等のエステル化反応生成物は、引き続いて重縮合反応に供される。この重縮合反応は、多段階の重縮合反応槽に供給することにより好適に行なうことが可能である。 The esterification reaction product such as an oligomer generated by the esterification reaction is subsequently subjected to a polycondensation reaction. This polycondensation reaction can be suitably performed by supplying it to a multistage polycondensation reaction tank.
　例えば、３段階の反応槽で行なう場合の重縮合反応条件は、第一反応槽は、反応温度が２５５℃～２８０℃、より好ましくは２６５℃～２７５℃であり、圧力が１００ｔｏｒｒ～１０ｔｏｒｒ（１３．３×１０－３ＭＰａ～１．３×１０－３ＭＰａ）、より好ましくは５０ｔｏｒｒ～２０ｔｏｒｒ（６．６７×１０－３ＭＰａ～２．６７×１０－３ＭＰａ）であって、第二反応槽は、反応温度が２６５℃～２８５℃、より好ましくは２７０℃～２８０℃であり、圧力が２０ｔｏｒｒ～１ｔｏｒｒ（２．６７×１０－３ＭＰａ～１．３３×１０－４ＭＰａ）、より好ましくは１０ｔｏｒｒ～３ｔｏｒｒ（１．３３×１０－３ＭＰａ～４．０×１０－４ＭＰａ）であって、最終反応槽内における第三反応槽は、反応温度が２７０℃～２９０℃、より好ましくは２７５℃～２８５℃であり、圧力が１０ｔｏｒｒ～０．１ｔｏｒｒ（１．３３×１０－３ＭＰａ～１．３３×１０－５ＭＰａ）、より好ましくは５ｔｏｒｒ～０．５ｔｏｒｒ（６．６７×１０－４ＭＰａ～６．６７×１０－５ＭＰａ）である態様が好ましい。 For example, the polycondensation reaction conditions in the case of performing in a three-stage reaction tank are as follows: the first reaction tank has a reaction temperature of 255 ° C. to 280 ° C., more preferably 265 ° C. to 275 ° C., and a pressure of 100 to 10 torr (13 3 × 10 −3 MPa to 1.3 × 10 −3 MPa), more preferably 50 to 20 torr (6.67 × 10 −3 MPa to 2.67 × 10 −3 MPa), and the second reaction The tank has a reaction temperature of 265 ° C. to 285 ° C., more preferably 270 ° C. to 280 ° C., and a pressure of 20 to 1 torr (2.67 × 10 −3 MPa to 1.33 × 10 −4 MPa), more preferably. a 10 torr ~ 3 torr is (1.33 × 10 -3 MPa ~ 4.0 × 10 -4 MPa), a third reaction vessel in the final reaction tank, the reaction temperature is 270 ° C. ~ 290 , More preferably from 275 ° C. ~ 285 ° C., the pressure is 10torr ~ 0.1torr (1.33 × 10 -3 MPa ~ 1.33 × 10 -5 MPa), more preferably 5torr ~ 0.5torr (6. An aspect of 67 × 10 −4 MPa to 6.67 × 10 −5 MPa) is preferable.
　上記のようにして合成されたポリエステルには、光安定化剤、酸化防止剤、紫外線吸収剤、難燃剤、易滑剤（微粒子）、核剤（結晶化剤）、結晶化阻害剤などの添加剤を更に含有させてもよい。 Additives such as light stabilizers, antioxidants, UV absorbers, flame retardants, lubricants (fine particles), nucleating agents (crystallization agents), crystallization inhibitors, etc. to the polyester synthesized as described above May further be included.
（結晶化）
　固相重合工程では、上記のようにして合成されたポリエステル、または市販のポリエステルのうち、結晶化度分布Δρが３％＜Δρ≦１５％であるポリエステルを用いる。
　結晶化度分布Δρは、以下のようにして算出することができる。
１）反応槽に供給する直前のポリエステルを１００粒、無造作に取り出す。
２）取り出したポリエステル１粒ずつの比重を密度勾配法にて測定し、下記式（ａ）により各ポリエステルの結晶化度を算出する。
　式（ａ）　　　　結晶化度（％）＝｛（ｄ－ｄＡ）／（ｄＣ－ｄＡ）｝×１００
　前記式（ａ）中、ｄＡはポリエステルの完全非晶時の密度、ｄＣは完全結晶時の密度、ｄはポリエステルの密度であり、ｄＡ＝１．３３５、ｄＣ＝１．５０１として算出すればよい。
３）取り出したポリエステル１００粒について算出した結晶化度ρの平均値を算出する。
　また、ポリエステル１００粒について算出した結晶化度ρの最大値ρｍａｘと最小値ρｍｉｎとの差から、下記（ｂ）式によって結晶化度のバラツキである結晶化度分布Δρを求める。
　式（ｂ）　　　　Δρ（％）＝［（｜ρｍａｘ－ρｍｉｎ｜）／ρの平均値］×１００
　ポリエステルの結晶化は、一般に、ポリエステルを加熱することにより行うことができる。加熱方法としては、例えば、ポリエステルを金属に接触させたり、ポリエステルに温熱ガスを供給し熱交換すること等が挙げられる。 (Crystallization)
In the solid phase polymerization step, a polyester having a crystallinity distribution Δρ of 3% <Δρ ≦ 15% among the polyester synthesized as described above or a commercially available polyester is used.
The crystallinity distribution Δρ can be calculated as follows.
1) 100 grains of polyester immediately before being supplied to the reaction tank are randomly taken out.
2) The specific gravity of each polyester taken out is measured by the density gradient method, and the crystallinity of each polyester is calculated by the following formula (a).
Formula (a) Crystallinity (%) = {(d−dA) / (dC−dA)} × 100
In the above formula (a), dA is the density when the polyester is completely amorphous, dC is the density when the polyester is completely crystallized, d is the density of the polyester, and dA = 1.335 and dC = 1.501. .
3) The average value of the degree of crystallinity ρ calculated for the 100 polyesters taken out is calculated.
Further, from the difference between the maximum value ρmax and the minimum value ρmin of the crystallinity ρ calculated for 100 polyester grains, a crystallinity distribution Δρ, which is a variation in crystallinity, is obtained by the following equation (b).
Formula (b) Δρ (%) = [(| ρmax−ρmin |) / average value of ρ] × 100
In general, the crystallization of the polyester can be performed by heating the polyester. Examples of the heating method include bringing the polyester into contact with a metal or supplying a hot gas to the polyester to exchange heat.
　金属に接触させる方法は、具体的には、加熱したスクリュー状の金属板にポリエステルの粒子を投与し、スクリューを回転させることでポリエステルを加熱する方法（トーラスディスク法）である。
　しかしながら、ポリエステルを金属に接触させる上記の加熱方法では、金属とポリエステルとの接触、またはポリエステル同士の接触により、摩擦が生じ、ポリエステルの粉くずが発生することがあった。また、かかる金属に接触させる方法による結晶化では、ポリエステルの結晶化度ρが、例えば、３９％～４２％（結晶化度分布Δρが３％）の範囲に収まり、分布が狭くなり易い。
　もっとも、結晶化度分布Δρが広いポリエステルを得るために、トーラスディスク法により種々の結晶化度のポリエステルを用意し、混合して３％＜Δρ≦１５％のポリエステルを用意してもよい。 Specifically, the method of contacting the metal is a method in which polyester particles are administered to a heated screw-shaped metal plate and the polyester is heated by rotating the screw (torus disk method).
However, in the above heating method in which the polyester is brought into contact with the metal, friction may occur due to contact between the metal and the polyester or contact between the polyesters, and polyester dust may be generated. Further, in the crystallization by the method of contacting with a metal, the crystallinity ρ of the polyester falls within, for example, a range of 39% to 42% (crystallinity distribution Δρ is 3%), and the distribution tends to be narrow.
However, in order to obtain a polyester having a wide crystallinity distribution Δρ, polyesters having various crystallinities may be prepared by the torus disk method and mixed to prepare a polyester of 3% <Δρ ≦ 15%.
　一方、温熱ガスによってポリエステルを加熱する熱方法によれば、間接加熱による加熱のため，温度ムラが起こり易く、結晶化度分布Δρが広いポリエステルを得易い。かかる温熱ガスによる加熱方法によれば、例えば、エステルの結晶化度ρが３３％～４４％（結晶化度分布Δρが１１％）の範囲におよび、分布が広くなる。 On the other hand, according to the heating method in which the polyester is heated by the hot gas, the temperature unevenness is likely to occur due to indirect heating, and it is easy to obtain a polyester having a wide crystallinity distribution Δρ. According to this heating method using a hot gas, for example, the crystallinity ρ of the ester is in the range of 33% to 44% (the crystallinity distribution Δρ is 11%), and the distribution becomes wide.
　温熱ガスを用いたポリエステルの加熱方法（結晶化方法）について、図１を用いて、具体的に説明する。
　図１は、ポリエステルを加熱する結晶化装置の構成例を示す概略断面図である。
　図１には、結晶化装置１００が示されている。
　結晶化装置１００は、壁面に温熱ガス（例えば、窒素ガス）を内部に供給可能な温熱ガス供給口４、６、及び温熱ガス排出口１２、１４を有する。図１では、温熱ガス供給口が２つ示されているが、１つのみであってもよいし、３つ以上であってもよい。さらに、結晶化装置１００は、上部にポリエステルを投入するための開口部８を有し、下部に、加熱したポリエステルを排出可能な開口部１０を有している。 A polyester heating method (crystallization method) using a hot gas will be specifically described with reference to FIG.
FIG. 1 is a schematic cross-sectional view showing a configuration example of a crystallization apparatus for heating polyester.
FIG. 1 shows a crystallization apparatus 100.
The crystallization apparatus 100 has hot gas supply ports 4 and 6 and hot gas discharge ports 12 and 14 that can supply hot gas (for example, nitrogen gas) to the wall. In FIG. 1, two hot gas supply ports are shown, but there may be only one or three or more. Furthermore, the crystallization apparatus 100 has an opening 8 for feeding polyester at the upper part and an opening 10 for discharging heated polyester at the lower part.
　また、結晶化装置１００の内部壁面には、複数の棒が（その１つが棒２）が取り付けられている。棒の少なくとも一部は、温熱ガス供給口６よりも上側に設置される。棒は、図１では、断面が三角形の三角柱であり、軸方向が重力方向とほぼ垂直になるように取り付けられている。隣接する棒は、ポリエステルが通過可能な程度の間隔を空けて、配置されている。結晶化装置１００の上部の開口部８から投入されたポリエステルは、棒に当たることにより飛散し、温熱ガス供給口より供給された温熱ガスがポリエステルに当たり易い。すなわち、複数の棒が結晶化装置１００の空間に配置されていることにより、結晶化装置１００の上部の開口部８より投入されるポリエステルが、一塊となって結晶化装置１００内に入っても、棒により当たって減速すると共にバラバラに分けられ、温熱ガスとの接触時間が長くなるため、ポリエステルが加熱され易くなる。
　また、温熱ガスの熱を受け易いように、ポリエステルは、ペレットのような粒子状（ポリエステル粒子）であることが好ましい。 A plurality of rods (one of which is a rod 2) are attached to the inner wall surface of the crystallization apparatus 100. At least a part of the bar is installed above the hot gas supply port 6. In FIG. 1, the rod is a triangular prism having a triangular cross section, and is attached so that the axial direction is substantially perpendicular to the direction of gravity. Adjacent bars are arranged with an interval sufficient to allow the polyester to pass through. The polyester introduced from the opening 8 at the top of the crystallization apparatus 100 is scattered by hitting the rod, and the hot gas supplied from the hot gas supply port easily hits the polyester. That is, since a plurality of rods are arranged in the space of the crystallization apparatus 100, even if the polyester charged through the opening 8 at the top of the crystallization apparatus 100 enters the crystallization apparatus 100 as a lump. The polyester is easily heated because the contact with the hot gas is prolonged due to slowing down by hitting with a stick and falling apart.
Also, as susceptible to heat thermal gas, polyester is preferably a pellet of such particulate (polyester particles).
　なお、棒２は、温熱ガスの熱をポリエステルに供給し易くするための手段の一つにすぎない。従って、図１では、断面が三角形の三角柱であるが、断面形状は円形でも、四角形、六角形等の多角形でもよいし、また、篩のような網を有する板や、格子のようなスリットを有する板を、数段重ねて用いてもよい。例えば、三角柱のスリットを有するスリット板を５段重ねて用いてもよい。この際、隣接する板において、三角柱間の空間の位置が重ならないように、上側の三角柱間の空間の下に、下側の三角柱が位置するように、スリットの位置を調整することが好ましい。
　温熱ガスを用いたポリエステルの結晶化装置としては、ビューラー社製のルーフ型乾燥機として入手することもでき、かかる装置を用いてポリエステルを結晶化してもよい。 The rod 2 is only one means for facilitating the supply of hot gas heat to the polyester. Therefore, in FIG. 1, the cross section is a triangular prism, but the cross-sectional shape may be a circle, a polygon such as a quadrangle, a hexagon, etc., a plate having a net like a sieve, or a slit like a grid You may use the board which has 2 layers in piles. For example, five slit plates having triangular prism slits may be used. At this time, it is preferable to adjust the position of the slit so that the lower triangular prism is located below the space between the upper triangular prisms so that the positions of the spaces between the triangular prisms do not overlap in adjacent plates.
A polyester crystallization apparatus using a hot gas can be obtained as a roof type dryer manufactured by Buehler, and the apparatus may be used to crystallize the polyester.
　また、温熱ガスにより加熱されたポリエステルは、図示しない循環装置により、結晶化装置１００の上部の開口部８の上部まで戻し、開口部８から再度投入することにより加熱を繰り返すことが好ましい。
　結晶化装置１００での加熱完了後は、結晶化装置１００の下部の開口部１０から排出される。 In addition, it is preferable that the polyester heated by the hot gas is returned to the upper part of the opening 8 at the upper part of the crystallization apparatus 100 by a circulation device (not shown), and is heated again by being charged again from the opening 8.
After the heating in the crystallization apparatus 100 is completed, it is discharged from the opening 10 at the lower part of the crystallization apparatus 100.
　上記の温熱ガスによる加熱により、結晶化度分布Δρが、３％＜Δρ≦１５％のポリエステルを、容易に得ることができる。結晶化度分布Δρが、３％＜Δρ≦１５％であるということは、ポリエステルの結晶化度ρが広範囲にばらついていることを示し、ポリエステルの結晶化度ρがばらつくのは、ポリエステルの加熱時間にバラツキがあることを意味すると考えられる。すなわち、温熱ガスによる加熱は、金属接触による加熱よりも均一に加熱し難いと考えられる。 By heating with the above-mentioned hot gas, a polyester having a crystallinity distribution Δρ of 3% <Δρ ≦ 15% can be easily obtained. A crystallinity distribution Δρ of 3% <Δρ ≦ 15% indicates that the crystallinity ρ of the polyester varies widely, and the crystallinity ρ of the polyester varies due to heating of the polyester. It is thought to mean that there is a variation in time. That is, it is considered that heating with warm gas is more difficult to heat uniformly than heating with metal contact.
　一方、加熱（結晶化）により得られるポリエステルの結晶子径Ｄのバラツキ（結晶子径分布ΔＤ）は、小さい方が好ましく、ΔＤは１０％以下であることが好ましい。
　なお、結晶子径とは、結晶を構成する最小結晶単位の大きさ（最大径）であり、一般に、Ｘ線回折装置を用いて測定することができる。
　ポリエステルの結晶子径Ｄは、ポリエステルの加熱温度がばらつくことで、ばらつき易いと考えられることから、温熱ガスの温度は、一定に保つことが好ましい。 On the other hand, the variation in crystallite diameter D (crystallite diameter distribution ΔD) of the polyester obtained by heating (crystallization) is preferably smaller, and ΔD is preferably 10% or less.
The crystallite diameter is the size (maximum diameter) of the minimum crystal unit constituting the crystal, and can generally be measured using an X-ray diffractometer.
The crystallite diameter D of the polyester is considered to be likely to vary due to variations in the heating temperature of the polyester. Therefore, it is preferable to keep the temperature of the hot gas constant.
　ここで、温熱ガスの温度は、１７５℃～２１５℃とすることが好ましく、１８５℃～２０５℃とすることがより好ましい。
　温熱ガスは、不活性ガスであることが好ましく、例えば、窒素（Ｎ２）ガス、アルゴン（Ａｒ）ガス，二酸化炭素（ＣＯ２）ガス等が挙げられる。 Here, the temperature of the thermal gas is preferably set to 175 ° C. ~ 215 ° C., and more preferably set to 185 ℃ ~ 205 ℃.
The hot gas is preferably an inert gas, and examples thereof include nitrogen (N 2 ) gas, argon (Ar) gas, carbon dioxide (CO 2 ) gas, and the like.
　また、ポリエステルの加熱時間は、３時間～１０時間であることが好ましく、３時間～８時間であることがより好ましい。
　３時間以上であると、加熱時間にバラツキが生じ、結晶化度分布Δρを大きくし易い。１０時間以下であると、ポリエステルの過熱や過熱による熱分解を抑制することができる。 The heating time for the polyester is preferably 3 hours to 10 hours, more preferably 3 hours to 8 hours.
When it is 3 hours or more, the heating time varies, and the crystallinity distribution Δρ is easily increased. When it is 10 hours or less, thermal decomposition due to overheating or overheating of the polyester can be suppressed.
　また、温熱ガスの供給量と、ポリエステルの投入量との割合を制御することでも、ポリエステルの結晶化度ρをばらつかせることができる。
　具体的には、温熱ガスの供給量〔Ｎｍ３／Ｋｇ〕は、ポリエステル１ｋｇに対して、０．１Ｎｍ３～１．５Ｎｍ３とすることが好ましい。ポリエステルの結晶化装置１００への投入量と、温熱ガスの供給量とを、上記割合とすることで、結晶化度分布Δρが３％＜Δρ≦１５％のポリエステルを得易い。
　温熱ガスの供給量は、ポリエステル１ｋｇに対して、０．３Ｎｍ３～１．０Ｎｍ３とすることがより好ましい。
　ポリエステルの供給量が一定であるときは、上記温熱ガスの供給量との比は、反応槽内を通過する温熱ガスの風速（空塔速度）にて調整することができる。
　例えば、ポリエステルの投入量を、３００ｋｇ／ｈｒで一定にして装置に投入し、温熱ガスを２００Ｎｍ３／ｈｒで供給する場合は、温熱ガスの風速（空塔速度）を、０．３ｍ／ｓｅｃ～１０ｍ／ｓｅｃ（好ましくは、０．５ｍ／ｓｅｃ～５．０ｍ／ｓｅｃ）の範囲とすることで、ポリエステル１ｋｇに対する温熱ガスの供給量を０．１Ｎｍ３～１．５Ｎｍ３とすることができる。 Also, the degree of crystallinity ρ of the polyester can be varied by controlling the ratio between the supply amount of the hot gas and the input amount of the polyester.
Specifically, the supply amount of heat gas [Nm 3 / Kg] is the polyester 1 kg, it is preferable to 0.1Nm 3 ~ 1.5Nm 3. By setting the amount of polyester charged into the crystallization apparatus 100 and the amount of hot gas supplied to the above ratio, it is easy to obtain a polyester having a crystallinity distribution Δρ of 3% <Δρ ≦ 15%.
The supply amount of the hot gas is more preferably 0.3 Nm 3 to 1.0 Nm 3 with respect to 1 kg of polyester.
When the supply amount of polyester is constant, the ratio to the supply amount of the hot gas can be adjusted by the wind speed (superficial velocity) of the hot gas passing through the reaction vessel.
For example, in the case where polyester is charged at a constant rate of 300 kg / hr, and the hot gas is supplied at 200 Nm 3 / hr, the hot gas wind speed (superficial velocity) is 0.3 m / sec to 10 m / sec (preferably, 0.5m / sec ~ 5.0m / sec ) in a range of from, it is possible to supply the amount of heat gas to polyester 1kg and 0.1Nm 3 ~ 1.5Nm 3.
　加熱（結晶化）により得るポリエステルの結晶化度分布Δρは、５％～１３％であることが好ましく、８％～９％であることが特に好ましい。 The crystallinity distribution Δρ of polyester obtained by heating (crystallization) is preferably 5% to 13%, particularly preferably 8% to 9%.
　また、加熱（結晶化）により得るポリエステルの結晶子径Ｄは、８０Å～１２０Åであることが好ましく、９０Å～１００Åであることがより好ましい。
　ポリエステルの結晶子径Ｄと結晶子径分布ΔＤは次のようにして求めることができる。 The crystallite diameter D of the polyester obtained by heating (crystallization) is preferably from 80 to 120 mm, and more preferably from 90 to 100 mm.
The crystallite diameter D and the crystallite diameter distribution ΔD of the polyester can be obtained as follows.
１）反応槽に供給する直前のポリエステルを１００粒、無造作に取り出す。
２）そのポリエステル１粒を乳鉢にて紛体とし、下記方法にて結晶子径Ｄを求める。
　Ｃｕ－Ｋα１線を用いたＸ線回折解析を行う。その後、２θ＝４ｄｅｇ～７０ｄｅｇの範囲において、最大強度を示すピークか、あるいは近接するピークと分離可能な十分に大きな強度を示すピークの半値幅を測定し、下記のＳｈｅｒｒｅｒの式により、結晶子径を算出する：
　　Ｄ＝Ｋ×λ／（β×ｃｏｓθ）・・・Ｓｃｈｅｒｒｅｒの式
〔Ｄ：結晶子径（Å、結晶子の大きさ）、λ：測定Ｘ線波長（Å）、β：結晶の大きさによる回折線の広がり（ラジアン）、θ：回折線のブラッグ角（ラジアン）、Ｋ：定数（βとＤの定数で異なる）〕 1) 100 grains of polyester immediately before being supplied to the reaction tank are randomly taken out.
2) One polyester grain is made into a powder in a mortar, and the crystallite diameter D is determined by the following method.
X-ray diffraction analysis using Cu-Kα1 line is performed. Thereafter, in the range of 2θ = 4 deg to 70 deg, the half-value width of the peak showing the maximum intensity or the peak showing a sufficiently large intensity that can be separated from the adjacent peak is measured, and the crystallite diameter is calculated by the following Sherler's formula. Calculate:
D = K × λ / (β × cos θ)... Scherrer equation [D: crystallite diameter (Å, crystallite size), λ: measured X-ray wavelength (、), β: crystal size Diffraction line broadening (radian), θ: Bragg angle of diffraction line (radian), K: Constant (different depending on β and D constants)]
３）ポリエステル１００粒について結晶子径Ｄを測定し，それらの値から，反応槽に供給するポリエステルの結晶子径Ｄの平均値を求め，また結晶子径Ｄの最大値と最小値の差を結晶子径Ｄの平均値で除すことによって，結晶子径Ｄのバラツキ（結晶子径分布ΔＤ）を求める。
　結晶子径分布ΔＤは、好ましくは３％～９％である。 3) The crystallite diameter D is measured for 100 polyester grains, and from these values, the average value of the crystallite diameter D of the polyester supplied to the reaction vessel is obtained, and the difference between the maximum value and the minimum value of the crystallite diameter D is calculated. Dividing the crystallite diameter D by the average value of the crystallite diameter D (crystallite diameter distribution ΔD) is obtained.
The crystallite size distribution ΔD is preferably 3% to 9%.
（固相重合）
　固相重合工程では、結晶化度分布Δρが、３％＜Δρ≦１５％のポリエステルを、反応槽に供給して固相重合する。
　ポリエステルの固相重合は、連続法（タワーの中に樹脂を充満させ、これを加熱しながらゆっくり所定の時間滞流させた後、順次送り出す方法）でもよく、バッチ法（容器の中に樹脂を投入し、所定の時間加熱する方法）でもよい。 (Solid phase polymerization)
In the solid phase polymerization step, a polyester having a crystallinity distribution Δρ of 3% <Δρ ≦ 15% is supplied to the reaction vessel and subjected to solid phase polymerization.
The solid phase polymerization of polyester may be a continuous method (a method in which a tower is filled with a resin, and this is slowly heated for a predetermined period of time while being heated and then sequentially fed out), or a batch method (a resin is placed in a container). Or a method of heating for a predetermined time).
　固相重合の温度は、１７０℃～２４０℃が好ましく、より好ましくは１８０℃～２３０℃であり、さらに好ましくは１９０℃～２２０℃である。温度が上記範囲内であると、ポリエステルの末端ＣＯＯＨ量（ＡＶ）がより大きく低減することの点で好ましい。また、固相重合時間は、５時間～１００時間が好ましく、より好ましくは１０時間～７５時間であり、さらに好ましくは１５時間～５０時間である。時間が上記範囲内であると、ポリエステルの末端ＣＯＯＨ量（ＡＶ）と固有粘度（ＩＶ）の本発明の好ましい範囲に容易に制御できる点で好ましい。固相重合は、真空中あるいは窒素雰囲気下で行なうことが好ましい。 The temperature of solid phase polymerization is preferably 170 ° C. to 240 ° C., more preferably 180 ° C. to 230 ° C., and further preferably 190 ° C. to 220 ° C. When the temperature is within the above range, the amount of terminal COOH (AV) of the polyester is preferably reduced. The solid phase polymerization time is preferably 5 hours to 100 hours, more preferably 10 hours to 75 hours, and further preferably 15 hours to 50 hours. When the time is within the above range, it is preferable in that the terminal COOH amount (AV) and intrinsic viscosity (IV) of the polyester can be easily controlled within the preferable ranges of the present invention. The solid phase polymerization is preferably performed in a vacuum or in a nitrogen atmosphere.
　また、反応槽に入れるときのポリエステルの温度は、１８０℃～２２０℃であることが好ましい。固相重合前に、予めポリエステルを上記温度範囲に加熱しておくことで、反応槽でのペレット温度を１８０℃～２２０℃にすることができる。
　反応槽に入れるときのポリエステルの温度は、１９０℃～２１０℃であることがより好ましい。 The temperature of the polyester when it is put into the reaction vessel is preferably 180 ° C. to 220 ° C. Prior to solid phase polymerization, the temperature of the pellets in the reaction vessel can be set to 180 ° C. to 220 ° C. by preheating the polyester to the above temperature range.
The temperature of the polyester when entering the reaction vessel is more preferably 190 ° C. to 210 ° C.
　エステル化反応によりポリエステルを重合した後に、さらに固相重合することにより、ポリエステルの含水率、結晶化度、ポリエステルの酸価、すなわち、ポリエステルの末端ＣＯＯＨの濃度（ＡＶ）、固有粘度（ＩＶ）を制御することができる。
　ポリエステルの固有粘度（ＩＶ）［単位ｄｌ／ｇ］は、０．７～０．９であることが好ましい。
　固有粘度が０．７以上であると、ポリエステルの分子運動が阻害されて結晶化しにくくすることができ、０．９以下であると、押出機内の剪断発熱によるポリエステルの熱分解が起こり過ぎず、結晶化を抑制し、また、末端ＣＯＯＨ量（ＡＶ）を低く抑えることができる。
　ＩＶは、０．７０～０．８５であることがより好ましく、０．７３～０．８０であることが特に好ましい。 After the polyester is polymerized by the esterification reaction, the water content of the polyester, the crystallinity, the acid value of the polyester, that is, the concentration of terminal COOH (AV) and the intrinsic viscosity (IV) of the polyester are further increased by solid phase polymerization. Can be controlled.
The intrinsic viscosity (IV) [unit dl / g] of the polyester is preferably 0.7 to 0.9.
When the intrinsic viscosity is 0.7 or more, the molecular motion of the polyester is hindered and it is difficult to crystallize. When the intrinsic viscosity is 0.9 or less, thermal decomposition of the polyester due to shear heat generation in the extruder does not occur too much, Crystallization can be suppressed, and the amount of terminal COOH (AV) can be kept low.
IV is more preferably 0.70 to 0.85, and particularly preferably 0.73 to 0.80.
　特に、エステル化反応において、チタン（Ｔｉ）系触媒を使用し、さらに固相重合して、ポリエステルの固有粘度（ＩＶ）を、０．７～０．９とすることで、後述する押出成形工程における溶融樹脂の冷却において、ポリエステルが結晶化することを抑制し易い。 In particular, in the esterification reaction, a titanium (Ti) -based catalyst is used, and further solid-phase polymerization is performed, whereby the intrinsic viscosity (IV) of the polyester is set to 0.7 to 0.9, which will be described later. In cooling the molten resin, it is easy to suppress the crystallization of the polyester.
　なお、固有粘度（ＩＶ）は、溶液粘度（η）と溶媒粘度（η0）の比ηr（＝η/η0；相対粘度）から１を引いた比粘度（ηsp＝ηr－１）を濃度で割った値を濃度がゼロの状態に外挿した値である。ＩＶは、ウベローデ型粘度計を用い、ポリエステルを１，１，２，２－テトラクロルエタン／フェノール（＝２／３[質量比]）混合溶媒に溶解させ、２５℃の溶液粘度から求められる。
　また、末端ＣＯＯＨ量（ＡＶ）は、H. A. Pohl, Anal. Chem. 26 (1954) 2145に記載の方法にしたがって、滴定法にて測定することができる。具体的には、ポリエステルを、ベンジルアルコールに２０５℃で溶解し、フェノールレッド指示薬を加え、水酸化ナトリウムの水／メタノール／ベンジルアルコール溶液で滴定し、その適定量から算出する。 The intrinsic viscosity (IV) is a specific viscosity (η sp = η r −1) obtained by subtracting 1 from the ratio η r (= η / η 0 ; relative viscosity) of the solution viscosity (η) and the solvent viscosity (η 0 ). ) Divided by the density is extrapolated to a density zero state. IV is obtained from a solution viscosity at 25 ° C. by dissolving the polyester in a 1,1,2,2-tetrachloroethane / phenol (= 2/3 [mass ratio]) mixed solvent using an Ubbelohde viscometer.
The amount of terminal COOH (AV) can be measured by a titration method according to the method described in H. A. Pohl, Anal. Chem. 26 (1954) 2145. Specifically, polyester is dissolved in benzyl alcohol at 205 ° C., a phenol red indicator is added, titrated with a water / methanol / benzyl alcohol solution of sodium hydroxide, and calculated from the appropriate amount.
　ポリエステルの固相重合に用いるポリエステルは、既述のエステル化反応により重合し、結晶化したポリエステル又は市販のポリエステルを、ペレット状などの小片形状にしたものを、出発物質として用いればよい。 The polyester used for the solid phase polymerization of the polyester may be a polyester obtained by polymerizing and crystallizing by the above-described esterification reaction or a commercially available polyester in the form of pellets or the like as a starting material.
〔押出成形工程〕
　押出成形工程では、固相重合されたポリエステルを、フィルム状に押出成形する。
　具体的には、固相重合されたポリエステルを、押出機を用いて溶融混練し、口金（押出ダイ）から押出すことにより、ポリエステルフィルムを成形する。ポリエステルフィルムの厚みは２５０μｍ～５００μｍとすることが好ましい。 [Extrusion process]
In the extrusion process, the solid-phase polymerized polyester is extruded into a film.
Specifically, the polyester film is formed by melt-kneading the solid-phase polymerized polyester using an extruder and extruding it from a die (extrusion die). The thickness of the polyester film is preferably 250 μm to 500 μm.
　押出成形工程をより細かく分けると、固相重合されたポリエステルを溶融混練し、口金から押出す溶融混練・押出工程と、未延伸ポリエステルフィルムを冷却固化する冷却固化工程と、冷却固化後の未延伸フィルムを延伸する延伸工程と、により構成される。 The extrusion process is further divided into a melt-kneading and extrusion process in which solid-phase polymerized polyester is melted and extruded from a die, a cooling and solidification process in which an unstretched polyester film is cooled and solidified, and an unstretched state after cooling and solidification. And a stretching process for stretching the film.
～溶融混練・押出工程～
　ポリエステルの溶融は、ポリエステルを乾燥し、残留水分を１００ｐｐｍ以下にした後、押出機を用いて溶融することができる。溶融温度は、２５０℃～３２０℃が好ましく、２６０℃～３１０℃がより好ましく、２７０℃～３００℃がさらに好ましい。押出機は、１軸でも多軸でもよい。熱分解による末端ＣＯＯＨの発生をより抑制できる点で、押出機内を窒素置換して行なうのがより好ましい。
　溶融された溶融樹脂（メルト）は、ギアポンプ、濾過器等を通して、押出ダイから押出す。このとき、単層で押出してもよいし、多層で押出してもよい。 -Melt kneading and extrusion process-
Melting of the polyester, polyester was dried, after the residual moisture 100ppm or less, can be melted by using an extruder. The melting temperature is preferably 250 ° C to 320 ° C, more preferably 260 ° C to 310 ° C, and further preferably 270 ° C to 300 ° C. The extruder may be uniaxial or multi-axial. It is more preferable that the inside of the extruder is replaced with nitrogen from the viewpoint that generation of terminal COOH due to thermal decomposition can be further suppressed.
The melted molten resin (melt) is extruded from an extrusion die through a gear pump, a filter or the like. At this time, it may be extruded as a single layer or may be extruded as a multilayer.
～冷却固化工程～
　押出ダイから押出されたメルトは、チルロール（冷却ロール）を用いて固化することができる。このとき、チルロールの温度は、１０℃～８０℃が好ましく、より好ましくは１５℃～７０℃、さらに好ましくは２０℃～６０℃である。さらに、メルトとチルロールとの間で密着性を高め、冷却効率を上げる観点からは、チルロールにメルトが接触する前に静電気を印加しておくことが好ましい。さらに、チルロール反対面から冷風を当てたり、冷却ロールを接触させ、冷却を促すことも好ましい。これにより、厚手フィルム（具体的には、延伸後の厚みが２５０μｍ以上のフィルム）であっても、効果的に冷却が行なえる。
　なお、冷却が不充分な場合には、球晶が発生しやすく、これが延伸ムラを引き起こし、厚みムラを発生させることがある。 -Cooling and solidification process-
The melt extruded from the extrusion die can be solidified using a chill roll (cooling roll). At this time, the temperature of the chill roll is preferably 10 ° C. to 80 ° C., more preferably 15 ° C. to 70 ° C., and still more preferably 20 ° C. to 60 ° C. Furthermore, from the viewpoint of improving the adhesion between the melt and the chill roll and increasing the cooling efficiency, it is preferable to apply static electricity before the melt contacts the chill roll. Furthermore, it is also preferable to apply cooling air from the opposite surface of the chill roll or to contact a cooling roll to promote cooling. Thus, (specifically, the thickness after stretching is 250μm or more films) thick film be effectively cooling can be performed.
In addition, when the cooling is insufficient, spherulites are likely to be generated, which may cause uneven stretching and uneven thickness.
～延伸工程～
　上記工程の後には、作製された押出フィルム（未延伸フィルム）を２軸延伸することにより本発明のポリエステルフィルムを好適に作製することができる。 -Stretching process-
After the above step, the polyester film of the present invention can be suitably produced by biaxially stretching the produced extruded film (unstretched film).
　具体的には、未延伸のポリエステルフィルムを、７０℃～１４０℃の温度に加熱されたロール群に導き、長手方向（縦方向、すなわちフィルムの進行方向）に３倍～５倍の延伸率で延伸し、２０℃～５０℃の温度のロール群で冷却することが好ましい。続いて、フィルムの両端をクリップで把持しながらテンターに導き、８０℃～１５０℃の温度に加熱された雰囲気中で、長手方向に直角な方向（幅方向）に３倍～５倍の延伸率で延伸する。 Specifically, an unstretched polyester film is led to a group of rolls heated to a temperature of 70 ° C. to 140 ° C., and stretched at a stretch ratio of 3 to 5 times in the longitudinal direction (longitudinal direction, that is, the traveling direction of the film). The film is preferably stretched and cooled by a roll group having a temperature of 20 ° C. to 50 ° C. Subsequently, the film is guided to a tenter while holding both ends of the film with clips, and stretched in a direction perpendicular to the longitudinal direction (width direction) by 3 to 5 times in an atmosphere heated to a temperature of 80 ° C. to 150 ° C. Stretch with.
　延伸率は、長手方向と幅方向それぞれ３倍～５倍とするのが好ましい。また、その面積倍率（縦延伸倍率×横延伸倍率）は、９倍～１５倍であることが好ましい。面積倍率が９倍以上であると、得られる二軸延伸積層フィルムの反射率や隠蔽性、フィルム強度が良好であり、また面積倍率が１５倍以下であると、延伸時の破れを回避することができる。 The stretching ratio is preferably 3 to 5 times in each of the longitudinal direction and the width direction. The area ratio (longitudinal draw ratio × lateral draw ratio) is preferably 9 to 15 times. When the area magnification is 9 times or more, the reflectivity, concealability and film strength of the obtained biaxially stretched laminated film are good, and when the area magnification is 15 times or less, tearing during stretching should be avoided. Can do.
　二軸延伸する方法としては、上述のように、長手方向と幅方向の延伸とを分離して行なう逐次二軸延伸方法のほか、長手方向と幅方向の延伸を同時に行なう同時二軸延伸方法のいずれであってもよい。 As the biaxial stretching method, as described above, in addition to the sequential biaxial stretching method in which the longitudinal direction and the width direction are separated separately, the simultaneous biaxial stretching method in which the longitudinal direction and the width direction are simultaneously stretched. Either may be sufficient.
　得られた二軸延伸フィルムの結晶配向を完了させて、平面性と寸法安定性を付与するために、引き続きテンター内にて、好ましくは原料となる樹脂のガラス転移温度（Ｔｇ）以上融点（Ｔｍ）未満の温度で１秒～３０秒の熱処理を行ない、均一に徐冷後、室温まで冷却する。一般に、熱処理温度（Ｔｓ）が低いとフィルムの熱収縮が大きいため、高い熱寸法安定性を付与するためには、熱処理温度は高い方が好ましい。しかしながら、熱処理温度を高くし過ぎると配向結晶性が低下し、その結果形成されたフィルムが耐加水分解性に劣ることがある。そのため、本発明のポリエステルフィルムの熱処理温度（Ｔｓ）としては、４０℃≦（Ｔｍ－Ｔｓ）≦９０℃であるのが好ましい。より好ましくは、熱処理温度（Ｔｓ）を５０℃≦（Ｔｍ－Ｔｓ）≦８０℃、更に好ましくは５５℃≦（Ｔｍ－Ｔｓ）≦７５℃とすることが好ましい。 In order to complete the crystal orientation of the obtained biaxially stretched film and to impart flatness and dimensional stability, the melting point (Tm) above the glass transition temperature (Tg) of the resin, which is preferably the raw material, is preferably continued in the tenter. ) Heat treatment is performed at a temperature less than 1 second to 30 seconds, and after uniform cooling, cool to room temperature. In general, when the heat treatment temperature (Ts) is low, the thermal contraction of the film is large. Therefore, in order to impart high thermal dimensional stability, the heat treatment temperature is preferably higher. However, if the heat treatment temperature is too high, the orientation crystallinity is lowered, and as a result, the formed film may be inferior in hydrolysis resistance. Therefore, the heat treatment temperature (Ts) of the polyester film of the present invention is preferably 40 ° C. ≦ (Tm−Ts) ≦ 90 ° C. More preferably, the heat treatment temperature (Ts) is 50 ° C. ≦ (Tm−Ts) ≦ 80 ° C., more preferably 55 ° C. ≦ (Tm−Ts) ≦ 75 ° C.
　更には、本発明のポリエステルフィルムは、太陽電池発電モジュールを構成するバックシートとして用いることができるが、モジュール使用時には雰囲気温度が１００℃程度まで上昇することがあるため、熱処理温度（Ｔｓ）としては、１６０℃以上Ｔｍ－４０℃（但し、Ｔｍ－４０℃＞１６０℃）以下であるのが好ましい。より好ましくは１７０℃以上Ｔｍ－５０℃（但し、Ｔｍ－５０℃＞１７０℃）以下、更に好ましくはＴｓが１８０℃以上Ｔｍ－５５℃（但し、Ｔｍ－５５℃＞１８０℃）以下である。 Furthermore, although the polyester film of the present invention can be used as a back sheet constituting a solar cell power generation module, the atmospheric temperature may rise to about 100 ° C. when the module is used, so the heat treatment temperature (Ts) is It is preferably 160 ° C. or higher and Tm−40 ° C. (where Tm−40 ° C.> 160 ° C.) or lower. More preferably Tm-50 ℃ 170 ℃ or higher (provided that, Tm-50 ℃> 170 ℃) or less, more preferably Ts is Tm-55 ℃ 180 ℃ or higher (provided that, Tm-55 ℃> 180 ℃) or less.
　また必要に応じて、幅方向あるいは長手方向に３％～１２％の弛緩処理を施してもよい。
　弛緩処理における弛緩の割合「３％～１２％」は、弛緩前のポリエステルフィルムの長さをＬａ、弛緩後のポリエステルフィルムの長さをＬｂとしたとき、下記式（ｃ）により算出される。
　式（ｃ）　　　１００×（Ｌａ－Ｌｂ）／Ｌａ
　なお、ポリエステルフィルムの幅方向のＬａおよびＬｂ、並びに、ポリエステルフィルムの長手方向のＬａおよびＬｂは、次のように定義する。
［幅方向］
　テンターでポリエステルフィルムに緊張を与えて延伸したときの、延伸時におけるポリエステルフィルムの最大の幅を、弛緩前のポリエステルフィルムの長さＬａとする。また、緊張を解いて（弛緩して）ポリエステルフィルムをテンターから取り出すときのポリエステルフィルムの幅の長さを、弛緩後のポリエステルフィルムの長さＬｂとする。
［長手方向］
　テンターでポリエステルフィルムに緊張を与えて延伸したときの、延伸時におけるポリエステルフィルムに、長手方向に２点の印をつけ、その２点間の距離を弛緩前のポリエステルフィルムの長さＬａとする。また、緊張を解いて（弛緩して）テンターから取り出した後の前記２点間の距離を弛緩後のポリエステルフィルムの長さＬｂとする。 If necessary, relaxation treatment of 3% to 12% may be performed in the width direction or the longitudinal direction.
The relaxation ratio “3% to 12%” in the relaxation treatment is calculated by the following formula (c), where La is the length of the polyester film before relaxation and Lb is the length of the polyester film after relaxation.
Formula (c) 100 × (La−Lb) / La
The width direction of La and Lb of the polyester film, as well as the longitudinal direction of La and Lb of the polyester film is defined as follows.
[Width direction]
The maximum width of the polyester film at the time of stretching when the polyester film is stretched with a tenter is defined as the length La of the polyester film before relaxation. Moreover, let the length of the width | variety of the polyester film when releasing tension | tensile_strength (relaxing) and taking out a polyester film from a tenter be length Lb of the polyester film after relaxation | loosening.
[Longitudinal direction]
When the polyester film is stretched by applying tension to the polyester film with a tenter, two points are marked in the longitudinal direction, and the distance between the two points is the length La of the polyester film before relaxation. Further, the distance between the two points after the tension is released (relaxed) and taken out from the tenter is defined as the length Lb of the relaxed polyester film.
（ポリエステルフィルムの物性）
　本発明のポリエステルフィルムの製造方法により製造されたポリエステルフィルムは、上記固相重合を経ることにより、固有粘度（ＩＶ）と末端ＣＯＯＨ量（ＡＶ）が制御される。
　ポリエステルフィルムの固有粘度（ＩＶ）〔単位ｄｌ／ｇ〕は、０．７～０．９の範囲であるのが好ましく、より好ましくは０．７～０．８５、特に好ましくは０．７３～０．８０である。ＩＶが０．７以上であると、ポリエステルの分子量を所望範囲に保て、ポリエステルフィルムを多層構成とした際において、他層との密着界面で凝集破壊なく良好な密着を得ることができる。また、ＩＶが０．９以下であると、製膜中における溶融粘度が良好であり、剪断発熱によるポリエステルの熱分解が抑制され、末端ＣＯＯＨ量（ＡＶ）を低く抑えることができる。 (Physical properties of polyester film)
The intrinsic viscosity (IV) and terminal COOH amount (AV) of the polyester film produced by the method for producing a polyester film of the present invention are controlled through the solid phase polymerization.
The intrinsic viscosity (IV) [unit dl / g] of the polyester film is preferably in the range of 0.7 to 0.9, more preferably 0.7 to 0.85, and particularly preferably 0.73 to 0. .80. When IV is 0.7 or more, the molecular weight of the polyester is maintained in a desired range, and when the polyester film has a multilayer structure, good adhesion without cohesive failure can be obtained at the adhesion interface with other layers. When IV is 0.9 or less, the melt viscosity during film formation is good, thermal decomposition of the polyester due to shearing heat generation is suppressed, and the amount of terminal COOH (AV) can be suppressed low.
　さらに、本発明のポリエステルフィルムの製造方法により製造されたポリエステルフィルムは、特に長手方向での末端ＣＯＯＨ量（ＡＶ）がバラツキ難くすることができる。
一般に、フィルムまたはシートの製膜時には、一定のフィルム厚みを得るために、一定の吐出量で、溶融押出しすることが望まれ、特にＰＥＴの製膜時では、単軸のタンデム押出しや、ギアポンプアシスト型の二軸押出機が好まれて使用される。しかし、上記装置で、一定厚みのフィルムを得ることは出来るが、その際には、押出機のスクリュー回転数が変動してしまい、その結果、押出機内でのＰＥＴの熱分解（末端ＣＯＯＨの増加）が、スクリュー回転数の変動に対応して、起こってしまう。よって、フィルムの長手方向における、末端ＣＯＯＨの変動が起き、長手方向での耐加水分解性の不均一が生じてしまうと推察される。
　一方、本発明を用いると、一定のスクリュー回転で、ポリエステルの溶融押出しをした時の、吐出量の変動が小さくなり、その結果、一定のフィルム厚みが得られながら、熱分解の変動による末端ＣＯＯＨの変動を抑えることができる。これは、滑剤による押出し負荷の低減効果と類似した現象と考えている。 Furthermore, the polyester film produced by the method for producing a polyester film of the present invention can make the terminal COOH amount (AV) in the longitudinal direction difficult to vary.
In general, when a film or sheet is formed, in order to obtain a constant film thickness, it is desired to melt and extrude with a constant discharge amount. Particularly, when a PET film is formed, uniaxial tandem extrusion or gear pump assist is desired. A twin screw extruder of the type is preferred and used. However, a film having a constant thickness can be obtained with the above apparatus, but in that case, the screw rotation speed of the extruder fluctuates, and as a result, thermal decomposition of PET in the extruder (increase in terminal COOH) ) Occurs in response to fluctuations in the screw speed. Therefore, it is speculated that the terminal COOH varies in the longitudinal direction of the film, resulting in non-uniform hydrolysis resistance in the longitudinal direction.
On the other hand, when the present invention is used, the fluctuation of the discharge amount when the polyester is melt-extruded with a constant screw rotation is reduced, and as a result, a constant film thickness can be obtained while the terminal COOH due to the fluctuation of thermal decomposition is obtained. Fluctuations can be suppressed. This is considered to be a phenomenon similar to the effect of reducing the extrusion load by the lubricant.
　本発明のポリエステルフィルムの製造方法により製造されたポリエステルフィルムの末端ＣＯＯＨ量のバラツキを評価する方法の一例を、図２を用いて説明する。
　図２は、ポリエステルフィルムの末端ＣＯＯＨ量のバラツキの評価方法を説明するための長尺状の形状を有するポリエステルフィルムの模式図である。図２には、ポリエステルフィルム２０が示され、ポリエステルフィルム２０には、任意の点Ｐ１、Ｐ２、Ｐ３、Ｐｎ＋１、Ｐｎ（これらを「点Ｐ」と総称する）が示されている。点Ｐは、ポリエステルフィルム２０の長手方向（ＭＤ；Ｍａｃｈｉｎｅ　Ｄｉｒｅｃｔｉｏｎ）に１００ｍ間隔に並んでいる。点Ｐ３と点Ｐｎ＋１との間には、更に図示しない点を有していてもよいし、有していなくてもよい。また、点Ｐは、ポリエステルフィルム２０の幅方向（ＴＤ；Ｔｒａｎｓｖｅｒｓｅ　Ｄｉｒｅｃｔｉｏｎ）の中心に位置する。 An example of a method for evaluating the variation in the amount of terminal COOH of the polyester film produced by the method for producing a polyester film of the present invention will be described with reference to FIG.
FIG. 2 is a schematic view of a polyester film having a long shape for explaining a method for evaluating the variation in the amount of terminal COOH of the polyester film. FIG. 2 shows a polyester film 20, and arbitrary points P 1 , P 2 , P 3, P n + 1 , P n (these are collectively referred to as “point P”) are shown on the polyester film 20. The points P are lined up at 100 m intervals in the longitudinal direction (MD; Machine Direction) of the polyester film 20. Between the point P3 and the point P n + 1, may have a point which is not further shown, may not have. Further, the point P is located at the center of the polyester film 20 in the width direction (TD; Transverse Direction).
　点Ｐは、ポリエステルフィルムの末端ＣＯＯＨ量を測定する位置であり、ポリエステルフィルムの末端ＣＯＯＨ量のバラツキは、ｎ個の点Ｐにおける末端ＣＯＯＨ量を測定して算出する。具体的には、点Ｐが中心となるように、例えば長方形（図２に示す破線枠）の試料片を裁断し、得られたｎ個の試料片について末端ＣＯＯＨ量を測定し、末端ＣＯＯＨ量の平均値、末端ＣＯＯＨ量の最大値、及び末端ＣＯＯＨ量の最小値を調べる。
　測定された末端ＣＯＯＨ量の平均値、最大値、及び最小値から末端ＣＯＯＨ量のバラツキを評価する。
　なお、ポリエステルフィルムの末端ＣＯＯＨ量を測定する位置の数（ｎ）は、２０点である。 The point P is a position where the terminal COOH amount of the polyester film is measured, and the variation in the terminal COOH amount of the polyester film is calculated by measuring the terminal COOH amount at n points P. Specifically, for example, a rectangular (a broken line frame shown in FIG. 2) sample piece is cut so that the point P is the center, and the terminal COOH amount is measured for the obtained n sample pieces, and the terminal COOH amount is measured. The average value of the terminal COOH, the maximum value of the terminal COOH amount, and the minimum value of the terminal COOH amount are examined.
The variation of the terminal COOH amount is evaluated from the average value, the maximum value, and the minimum value of the measured terminal COOH amount.
The number (n) of positions for measuring the terminal COOH amount of the polyester film is 20 points.
　ポリエステルフィルムの末端ＣＯＯＨ量は、ポリエステルが有する末端ＣＯＯＨについて、フィルムの長手方向における前記末端ＣＯＯＨの量のバラツキが２（ｅｑ／ｔｏｎ）未満であることが好ましい。「末端ＣＯＯＨの量のバラツキが２（ｅｑ／ｔｏｎ）未満」とは、末端ＣＯＯＨ量の最大値と最小値の差が、２（ｅｑ／ｔｏｎ）未満の範囲内にあることを意味する。
　ポリエステルフィルムの長手方向における前記末端ＣＯＯＨの量のバラツキは１（ｅｑ／ｔｏｎ）以下であることがより好ましい。
　なお、本明細書中において、「ｅｑ／ｔｏｎ」は１トンあたりのモル当量を表す。 The terminal COOH amount of the polyester film is preferably such that the variation in the amount of terminal COOH in the longitudinal direction of the film is less than 2 (eq / ton) with respect to the terminal COOH of the polyester. “The variation in the amount of terminal COOH is less than 2 (eq / ton)” means that the difference between the maximum value and the minimum value of the terminal COOH amount is in the range of less than 2 (eq / ton).
The variation in the amount of the terminal COOH in the longitudinal direction of the polyester film is more preferably 1 (eq / ton) or less.
In the present specification, “eq / ton” represents a molar equivalent per ton.
　また、本発明のポリエステルフィルムの製造方法により得られたポリエステルフィルムは、温度１２０℃、相対湿度１００％の雰囲気下で保存した場合において、保存後の破断伸度が保存前の破断伸度に対して５０％となる保存時間（破断伸度半減時間）が、７０時間以上であることが好ましい。破断伸度半減時間は、より好ましくは１００時間以上、更に好ましくは、１２０時間以上である。 In addition, when the polyester film obtained by the method for producing a polyester film of the present invention is stored in an atmosphere at a temperature of 120 ° C. and a relative humidity of 100%, the breaking elongation after storage is higher than the breaking elongation before storage. Therefore, the storage time (breaking elongation half-life) of 50% is preferably 70 hours or more. The elongation at break half time is more preferably 100 hours or more, and still more preferably 120 hours or more.
　ポリエステルフィルムの耐加水分解性は、前記破断伸度半減時間により評価することが可能である。これは、強制的に加熱処理（サーモ処理）することで加水分解を促進させた際の破断伸度の低下から求められる。具体的な測定方法を以下に示す。 The hydrolysis resistance of the polyester film can be evaluated by the half elongation time at break. This is calculated | required from the fall of the breaking elongation at the time of promoting hydrolysis by heat-processing (thermo process) forcibly. A specific measurement method is shown below.
　破断伸度〔％〕は、ポリエステルフィルムから、１ｃｍ×２０ｃｍの大きさのサンプル片を切り出し、このサンプル片をチャック間５ｃｍ、２０％／分にて引っ張って求められる値である。 The elongation at break [%] is a value obtained by cutting a sample piece having a size of 1 cm × 20 cm from a polyester film and pulling the sample piece at a rate of 5 cm between chucks and 20% / min.
　ポリエステルフィルムは、一般に、厚みが増すに伴なって耐加水分解性が悪化し、例えば、風雨や直射日光に曝されるような過酷な使用環境下おける長期使用に耐えない傾向にある。
　一方、本発明のポリエステルフィルムの製造方法により得られたポリエステルフィルムは、優れた耐加水分解性を有し、さらに、ポリエステルフィルムの長手方向における末端ＣＯＯＨの量のバラツキが小さい。
　ポリエステルフィルムの長手方向における末端ＣＯＯＨの量のバラツキが小さいことで、ポリエステルフィルムの破断伸度半減時間のバラツキも小さくすることができ、ポリエステルフィルムの破断伸度半減時間にバラツキが生じ難い結果、長期経時で、フィルムの機能性にバラツキが生じ難い。
　したがって、本発明のポリエステルフィルムの製造方法により得られたポリエステルフィルムは、例えば、太陽電池発電モジュールとして構成した場合において、所望の発電性能を長期に亘って安定的に得ることができる。 Polyester films generally have poor hydrolysis resistance with increasing thickness, and tend not to withstand long-term use in harsh use environments such as exposure to wind and rain or direct sunlight.
On the other hand, the polyester film obtained by the method for producing a polyester film of the present invention has excellent hydrolysis resistance, and further, there is little variation in the amount of terminal COOH in the longitudinal direction of the polyester film.
Because the variation in the amount of terminal COOH in the longitudinal direction of the polyester film is small, the variation in the half elongation time of the polyester film can be reduced, and the variation in the half elongation time of the polyester film is less likely to occur. Over time, the film functionality is less likely to vary.
Therefore, when the polyester film obtained by the method for producing a polyester film of the present invention is configured as a solar cell power generation module, for example, desired power generation performance can be stably obtained over a long period of time.
　なお、本発明のポリエステルフィルムの製造方法により製造されるポリエステルフィルムは、延伸完了後の厚みが２５０μｍ～５００μｍであることが好ましい。 The polyester film produced by the method for producing a polyester film of the present invention preferably has a thickness after stretching of 250 μm to 500 μm.
（機能性層）
　本発明のポリエステルフィルムの製造方法により得られるポリエステルフィルムは、易接着性層、ＵＶ吸収層、白色層などの機能性層を少なくとも１層設けて構成することができる。例えば、１軸延伸後及び／又は２軸延伸後のポリエステルフィルムに下記の機能性層を塗設してもよい。塗設には、ロールコート法、ナイフエッジコート法、グラビアコート法、カーテンコート法等の公知の塗布技術を用いることができる。
　また、これらの塗設前に表面処理（火炎処理、コロナ処理、プラズマ処理、紫外線処理等）を実施してもよい。さらに、粘着剤を用いて貼り合わせることも好ましい。 (Functional layer)
The polyester film obtained by the method for producing a polyester film of the present invention can be constituted by providing at least one functional layer such as an easy-adhesive layer, a UV absorbing layer, and a white layer. For example, the following functional layer may be applied to a polyester film after uniaxial stretching and / or biaxial stretching. For coating, a known coating technique such as a roll coating method, a knife edge coating method, a gravure coating method, or a curtain coating method can be used.
Further, surface treatment (flame treatment, corona treatment, plasma treatment, ultraviolet treatment, etc.) may be performed before the coating. Furthermore, it is also preferable to bond together using an adhesive.
－易接着性層－
　ポリエステルフィルムは、太陽電池発電モジュールを構成する場合に、太陽電池素子が封止剤で封止された電池側基板の該封止材と向き合う側に、易接着性層を有していることが好ましい。易接着性層を設けることにより、バックシートと封止材との間を強固に接着することができる。具体的には、易接着性層は、特に封止材として用いられるＥＶＡ（エチレン－酢酸ビニル共重合体）との接着力が１０Ｎ／ｃｍ以上、好ましくは２０Ｎ／ｃｍ以上であることが好ましい。
　さらに、易接着性層は、太陽電池発電モジュールの使用中にバックシートの剥離が起こらないことが必要であり、そのために易接着性層は高い耐湿熱性を有することが望ましい。 -Easy adhesion layer-
When the polyester film constitutes a solar cell power generation module, the polyester film may have an easy-adhesive layer on the side facing the sealing material of the battery side substrate in which the solar cell element is sealed with a sealing agent. preferable. By providing the easy-adhesive layer, the back sheet and the sealing material can be firmly bonded. Specifically, it is preferable that the easily adhesive layer has an adhesive force of 10 N / cm or more, preferably 20 N / cm or more, particularly with EVA (ethylene-vinyl acetate copolymer) used as a sealing material.
Further, the easy-adhesion layer needs to prevent the back sheet from peeling off during use of the solar cell power generation module, and therefore, the easy-adhesion layer desirably has high moisture and heat resistance.
（１）バインダー
　易接着性層はバインダーの少なくとも１種を含有することができる。
　バインダーとしては、例えば、ポリエステル、ポリウレタン、アクリル樹脂、ポリオレフィン等を用いることができる。中でも、耐久性の観点から、アクリル樹脂、ポリオレフィンが、バインダーとして好ましい。また、アクリル樹脂として、アクリルとシリコーンとの複合樹脂も好ましい。好ましいバインダーの例として、以下のものを挙げることができる。
　ポリオレフィンの例として、ケミパールＳ－１２０、同Ｓ－７５Ｎ（ともに商品名、三井化学（株）製）が挙げられる。前記アクリル樹脂の例として、ジュリマーＥＴ－４１０、同ＳＥＫ－３０１（ともに商品名、日本純薬工業（株）製）が挙げられる。また、アクリルとシリコーンとの複合樹脂の例として、セラネートＷＳＡ１０６０、同ＷＳＡ１０７０（ともにＤＩＣ（株）製）、及びＨ７６２０、Ｈ７６３０、Ｈ７６５０（ともに商品名、旭化成ケミカルズ（株）製）が挙げられる。
　易接着性層中のバインダーの量は、０．０５ｇ／ｍ２～５ｇ／ｍ２の範囲が好ましく、０．０８ｇ／ｍ２～３ｇ／ｍ２の範囲が特に好ましい。バインダー量は、０．０５ｇ／ｍ２以上であることでより良好な接着力が得られ、５ｇ／ｍ２以下であることでより良好な面状が得られる。 (1) Binder The easy-adhesion layer can contain at least one binder.
As the binder, for example, polyester, polyurethane, acrylic resin, polyolefin, or the like can be used. Among these, acrylic resins and polyolefins are preferable as the binder from the viewpoint of durability. As the acrylic resin, a composite resin of acrylic and silicone is also preferable. The following can be mentioned as an example of a preferable binder.
Examples of polyolefins include Chemipearl S-120 and S-75N (both trade names, manufactured by Mitsui Chemicals, Inc.). Examples of the acrylic resin include Julimer ET-410 and SEK-301 (both trade names, manufactured by Nippon Pure Chemical Industries, Ltd.). Examples of the composite resin of acrylic and silicone include Ceranate WSA 1060, WSA 1070 (both manufactured by DIC Corporation), and H7620, H7630, H7650 (both trade names, manufactured by Asahi Kasei Chemicals Corporation).
The amount of the binder in the easy adhesion layer is preferably in the range of 0.05g / m 2 ~ 5g / m 2, the range of 0.08g / m 2 ~ 3g / m 2 is particularly preferred. The binder amount is more good adhesion is obtained by at 0.05 g / m 2 or more, a better surface is obtained by at 5 g / m 2 or less.
（２）微粒子
　易接着性層は、微粒子の少なくとも１種を含有することができる。易接着性層は、微粒子を層全体の質量に対して５％以上含有することが好ましい。
　微粒子としては、シリカ、炭酸カルシウム、酸化マグネシウム、炭酸マグネシウム、酸化錫等の無機微粒子が好適に挙げられる。特にこの中でも、湿熱雰囲気に曝されたときの接着性の低下が小さい点で、酸化錫、シリカの微粒子が好ましい。
　微粒子の粒径は、塗設後のフィルムの断面を走査型電子顕微鏡で観察することで測定することができ、１０ｎｍ～７００ｎｍ程度が好ましく、より好ましくは２０ｎｍ～３００ｎｍ程度である。粒径が前記範囲の微粒子を用いることにより、良好な易接着性を得ることができる。微粒子の形状には特に制限はなく、球形、不定形、針状形等のものを用いることができる。
　微粒子の易接着性層中における添加量としては、易接着性層中のバインダー当たり５～４００質量％が好ましく、より好ましくは５０～３００質量％である。微粒子の添加量は、５質量％以上であると、湿熱雰囲気に曝されたときの接着性に優れており、４００質量％以下であると、易接着性層の面状がより良好である。 (2) Fine particles The easy-adhesion layer can contain at least one kind of fine particles. The easy-adhesive layer preferably contains 5% or more of fine particles with respect to the mass of the entire layer.
As the fine particles, inorganic fine particles such as silica, calcium carbonate, magnesium oxide, magnesium carbonate, tin oxide and the like are preferably exemplified. In particular in this, in that reduction of adhesiveness is small when exposed to wet heat atmosphere, tin oxide, silica fine particles are preferred.
The particle size of the fine particles can be measured by observing the cross section of the coated film with a scanning electron microscope, preferably about 10 nm to 700 nm, more preferably about 20 nm to 300 nm. By using fine particles having a particle diameter in the above range, good easy adhesion can be obtained. The shape of the fine particles is not particularly limited, and those having a spherical shape, an indefinite shape, a needle shape, or the like can be used.
The addition amount of the fine particles in the easy-adhesive layer is preferably 5 to 400% by mass, more preferably 50 to 300% by mass, based on the binder in the easy-adhesive layer. When the addition amount of the fine particles is 5% by mass or more, the adhesiveness when exposed to a wet heat atmosphere is excellent, and when it is 400% by mass or less, the surface state of the easily adhesive layer is better.
（３）架橋剤
　易接着性層は、架橋剤の少なくとも１種を含有することができる。
　架橋剤の例としては、エポキシ系、イソシアネート系、メラミン系、カルボジイミド系、オキサゾリン系等の架橋剤を挙げることができる。湿熱経時後の接着性を確保する観点から、これらの中でも特にオキサゾリン系架橋剤が好ましい。
　オキサゾリン系架橋剤の具体例として、２－ビニル－２－オキサゾリン、２－ビニル－４－メチル－２－オキサゾリン、２－ビニル－５－メチル－２－オキサゾリン、２－イソプロペニル－２－オキサゾリン、２－イソプロペニル－４－メチル－２－オキサゾリン、２－イソプロペニル－５－エチル－２－オキサゾリン、２，２’－ビス－（２－オキサゾリン）、２，２’－メチレン－ビス－（２－オキサゾリン）、２，２’－エチレン－ビス－（２－オキサゾリン）、２，２’－トリメチレン－ビス－（２－オキサゾリン）、２，２’－テトラメチレン－ビス－（２－オキサゾリン）、２、２’－ヘキサメチレン－ビス－（２－オキサゾリン）、２，２’－オクタメチレン－ビス－（２－オキサゾリン）、２，２’－エチレン－ビス－（４，４’－ジメチル－２－オキサゾリン）、２，２’－ｐ－フェニレン－ビス－（２－オキサゾリン）、２，２’－ｍ－フェニレン－ビス－（２－オキサゾリン）、２，２’－ｍ－フェニレン－ビス－（４，４’－ジメチル－２－オキサゾリン）、ビス－（２－オキサゾリニルシクロヘキサン）スルフィド、ビス－（２－オキサゾリニルノルボルナン）スルフィド等が挙げられる。さらに、これらの化合物の（共）重合体も好ましく利用することができる。
　また、オキサゾリン基を有する化合物として、エポクロスＫ２０１０Ｅ、同Ｋ２０２０Ｅ、同Ｋ２０３０Ｅ、同ＷＳ５００、同ＷＳ７００（いずれも商品名、日本触媒化学工業（株）製）等も用いることができる。
　易接着性層中における架橋剤の好ましい添加量は、易接着性層のバインダー当たり５～５０質量％が好ましく、より好ましくは２０～４０質量％である。架橋剤の添加量は、５質量％以上であることで良好な架橋効果が得られ、反射層の強度低下や接着不良が起こりにくく、５０質量％以下であることで塗布液のポットライフをより長く保てる。 (3) Crosslinking agent The easy-adhesion layer can contain at least one crosslinking agent.
Examples of the crosslinking agent include epoxy-based, isocyanate-based, melamine-based, carbodiimide-based, and oxazoline-based crosslinking agents. Among these, an oxazoline-based cross-linking agent is particularly preferable from the viewpoint of securing adhesiveness after wet heat aging.
Specific examples of the oxazoline-based crosslinking agent include 2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, 2-isopropenyl-2-oxazoline, 2-isopropenyl-4-methyl-2-oxazoline, 2-isopropenyl-5-ethyl-2-oxazoline, 2,2′-bis- (2-oxazoline), 2,2′-methylene-bis- (2 -Oxazoline), 2,2'-ethylene-bis- (2-oxazoline), 2,2'-trimethylene-bis- (2-oxazoline), 2,2'-tetramethylene-bis- (2-oxazoline), 2,2'-hexamethylene-bis- (2-oxazoline), 2,2'-octamethylene-bis- (2-oxazoline), 2,2'-ethylene-bis- (4,4'-dimethyl) 2-oxazoline), 2,2'-p-phenylene-bis- (2-oxazoline), 2,2'-m-phenylene-bis- (2-oxazoline), 2,2'-m-phenylene- Examples thereof include bis- (4,4′-dimethyl-2-oxazoline), bis- (2-oxazolinylcyclohexane) sulfide, and bis- (2-oxazolinyl norbornane) sulfide. Furthermore, (co) polymers of these compounds can also be preferably used.
Further, as a compound having an oxazoline group, Epocros K2010E, K2020E, K2030E, WS500, WS700 (all trade names, manufactured by Nippon Shokubai Chemical Co., Ltd.) and the like can be used.
A preferable addition amount of the crosslinking agent in the easy-adhesive layer is preferably 5 to 50% by mass, more preferably 20 to 40% by mass, based on the binder of the easy-adhesive layer. When the addition amount of the crosslinking agent is 5% by mass or more, a good crosslinking effect is obtained, and the strength of the reflective layer is not reduced and adhesion failure hardly occurs, and when it is 50% by mass or less, the pot life of the coating liquid is further increased. I can keep it long.
（４）その他の添加剤
　易接着性層には、必要に応じて、更にポリスチレン、ポリメチルメタクリレート、シリカ等の公知のマット剤、アニオン系やノニオン系などの公知の界面活性剤などを添加してもよい。 (4) Other additives If necessary, a known matting agent such as polystyrene, polymethylmethacrylate or silica, or a known surfactant such as anionic or nonionic is added to the easily adhesive layer. May be.
（５）易接着性層の形成方法
　易接着性層の形成方法としては、易接着性を有するポリマーシートをポリエステルフィルムに貼合する方法や塗布による方法がある。塗布による方法は、簡便でかつ均一性の高い薄膜での形成が可能である点で好ましい。塗布方法としては、例えば、グラビアコーターやバーコーターなどの公知の方法を利用することができる。塗布に用いる塗布液の溶媒としては、水でもよいし、トルエンやメチルエチルケトンのような有機溶媒でもよい。溶媒は、１種類を単独で用いてもよいし、２種類以上を混合して用いてもよい。 (5) Formation method of an easily-adhesive layer As a formation method of an easily-adhesive layer, there exist the method of pasting the polymer sheet which has easy-adhesiveness to a polyester film, and the method by application | coating. The method by coating is preferable in that it can be formed with a simple and highly uniform thin film. As a coating method, for example, a known method such as a gravure coater or a bar coater can be used. The solvent of the coating solution used for coating may be water or an organic solvent such as toluene or methyl ethyl ketone. A solvent may be used individually by 1 type and may be used in mixture of 2 or more types.
（６）物性
　易接着性層の厚みには特に制限はないが、通常は０．０５μｍ～８μｍが好ましく、より好ましくは０．１μｍ～５μｍの範囲である。易接着性層の厚みは、０．０５μｍ以上であることで必要とする易接着性が得られやすく、８μｍ以下であることで面状をより良好に維持することができる。
　また、易接着性層は、ポリエステルフィルムとの間に着色層（特に反射層）が配置された場合の該着色層の効果を損なわない観点から、透明性を有していることが好ましい。 (6) Physical Properties The thickness of the easy-adhesion layer is not particularly limited, but is usually preferably 0.05 μm to 8 μm, more preferably 0.1 μm to 5 μm. When the thickness of the easy-adhesive layer is 0.05 μm or more, the required easy adhesion can be easily obtained, and when the thickness is 8 μm or less, the planar shape can be maintained better.
Moreover, it is preferable that an easily bonding layer has transparency from a viewpoint which does not impair the effect of this colored layer when a colored layer (especially reflective layer) is arrange | positioned between polyester films.
－紫外線吸収層－
　ポリエステルフィルムには、紫外線吸収剤を含む紫外線吸収層が設けられてもよい。紫外線吸収層は、ポリエステルフィルム上の任意の位置に配置することができる。
　紫外線吸収剤は、アイオノマー樹脂、ポリエステル樹脂、ウレタン樹脂、アクリル樹脂、ポリエチレン樹脂、ポリプロピレン樹脂、ポリアミド樹脂、酢酸ビニル樹脂、セルロースエステル樹脂等とともに、溶解、分散させて用いることが好ましく、４００ｎｍ以下の光の透過率を２０％以下にするのが好ましい。 -UV absorbing layer-
The polyester film may be provided with an ultraviolet absorbing layer containing an ultraviolet absorber. An ultraviolet absorption layer can be arrange | positioned in the arbitrary positions on a polyester film.
The ultraviolet absorber is preferably dissolved and dispersed together with an ionomer resin, polyester resin, urethane resin, acrylic resin, polyethylene resin, polypropylene resin, polyamide resin, vinyl acetate resin, cellulose ester resin, and the like. The transmittance is preferably 20% or less.
－着色層－
　ポリエステルフィルムには、着色層を設けることができる。着色層は、ポリエステルフィルムの表面に接触させて、あるいは他の層を介して配置される層であり、顔料やバインダーを用いて構成することができる。 -Colored layer-
A colored layer can be provided on the polyester film. The colored layer is a layer arranged in contact with the surface of the polyester film or through another layer, and can be constituted using a pigment or a binder.
　着色層の第一の機能は、入射光のうち太陽電池セルで発電に使われずにバックシートに到達した光を反射させて太陽電池セルに戻すことにより、太陽電池発電モジュールの発電効率を上げることにある。第二の機能は、太陽電池発電モジュールをオモテ面側から見た場合の外観の装飾性を向上することにある。一般に太陽電池発電モジュールをオモテ面側から見ると、太陽電池セルの周囲にバックシートが見えており、バックシートに着色層を設けることにより装飾性を向上させることができる。 The first function of the colored layer is to increase the power generation efficiency of the solar power generation module by reflecting the incident light that reaches the back sheet without being used for power generation in the solar cells and returning it to the solar cells. It is in. The second function is to improve the decorativeness of the appearance when the solar cell power generation module is viewed from the front side. In general, when the solar battery power generation module is viewed from the front side, a back sheet can be seen around the solar battery cell, and the decorativeness can be improved by providing a colored layer on the back sheet.
（１）顔料
　着色層は、顔料の少なくとも１種を含有することができる。顔料は、２．５ｇ／ｍ２～８．５ｇ／ｍ２の範囲で含有されるのが好ましい。より好ましい顔料含有量は、４．５ｇ／ｍ２～７．５ｇ／ｍ２の範囲である。顔料の含有量が２．５ｇ／ｍ２以上であることで、必要な着色が得られやすく、光の反射率や装飾性をより優れたものに調整することができる。顔料の含有量が８．５ｇ／ｍ２以下であることで、着色層の面状をより良好に維持することができる。 (1) Pigment The colored layer can contain at least one pigment. The pigment is preferably contained in the range of 2.5 g / m 2 to 8.5 g / m 2 . A more preferable pigment content is in the range of 4.5 g / m 2 to 7.5 g / m 2 . When the pigment content is 2.5 g / m 2 or more, necessary coloring can be easily obtained, and the light reflectance and decorativeness can be adjusted to be more excellent. When the pigment content is 8.5 g / m 2 or less, the planar shape of the colored layer can be maintained better.
　顔料としては、例えば、酸化チタン、硫酸バリウム、酸化珪素、酸化アルミニウム、酸化マグネシウム、炭酸カルシウム、カオリン、タルク、群青、紺青、カーボンブラック等の無機顔料、フタロシアニンブルー、フタロシアニングリーン等の有機顔料が挙げられる。これら顔料のうち、入射する太陽光を反射する反射層として着色層を構成する観点からは、白色顔料が好ましい。白色顔料としては、例えば、酸化チタン、硫酸バリウム、酸化珪素、酸化アルミニウム、酸化マグネシウム、炭酸カルシウム、カオリン、タルクなどが好ましい。 Examples of the pigment include inorganic pigments such as titanium oxide, barium sulfate, silicon oxide, aluminum oxide, magnesium oxide, calcium carbonate, kaolin, talc, ultramarine blue, bitumen, and carbon black, and organic pigments such as phthalocyanine blue and phthalocyanine green. It is done. Among these pigments, a white pigment is preferable from the viewpoint of constituting a colored layer as a reflective layer that reflects incident sunlight. As the white pigment, for example, titanium oxide, barium sulfate, silicon oxide, aluminum oxide, magnesium oxide, calcium carbonate, kaolin, talc and the like are preferable.
　顔料の平均粒径としては、０．０３μｍ～０．８μｍが好ましく、より好ましくは０．１５μｍ～０．５μｍ程度が好ましい。平均粒径が前記範囲内であると、光の反射効率が良好である。
　入射した太陽光を反射する反射層として着色層を構成する場合、顔料の反射層中における好ましい添加量は、用いる顔料の種類や平均粒径により変化するため一概には言えないが、１．５ｇ／ｍ２～１５ｇ／ｍ２が好ましく、より好ましくは３ｇ／ｍ２～１０ｇ／ｍ２程度である。添加量は、１．５ｇ／ｍ２以上であることで必要な反射率が得られやすく、１５ｇ／ｍ２以下であることで反射層の強度をより一層高く維持することができる。 The average particle size of the pigment is preferably 0.03 μm to 0.8 μm, more preferably about 0.15 μm to 0.5 μm. When the average particle size is within the above range, the light reflection efficiency is good.
When a colored layer is formed as a reflective layer that reflects incident sunlight, the preferred addition amount of pigment in the reflective layer varies depending on the type of pigment used and the average particle diameter, but cannot be generally stated, but 1.5 g / m 2 ~ is preferably 15 g / m 2, more preferably from 3g / m 2 ~ 10g / m 2 approximately. When the addition amount is 1.5 g / m 2 or more, the required reflectance is easily obtained, and when the addition amount is 15 g / m 2 or less, the strength of the reflection layer can be kept higher.
（２）バインダー
　着色層は、少なくとも１種のバインダーを含有することができる。バインダーを含む場合の量としては、前記顔料に対して、１５質量％～２００質量％の範囲が好ましく、１７質量％～１００質量％の範囲がより好ましい。バインダーの量は、１５質量％以上であることで着色層の強度を一層良好に維持することができ、２００質量％以下であることで反射率や装飾性が低下するのを防止する。
　着色層に好適なバインダーとしては、例えば、ポリエステル、ポリウレタン、アクリル樹脂、ポリオレフィン等を用いることができる。バインダーは、耐久性の観点から、アクリル樹脂、ポリオレフィンが好ましい。また、アクリル樹脂として、アクリルとシリコーンとの複合樹脂も好ましい。好ましいバインダーの例として、以下のものが挙げられる。
　前記ポリオレフィンの例としては、ケミパールＳ－１２０、同Ｓ－７５Ｎ（ともに商品名、三井化学（株）製)などが挙げられる。前記アクリル樹脂の例としては、ジュリマーＥＴ－４１０、ＳＥＫ－３０１（ともに商品名、日本純薬工業（株）製）などが挙げられる。前記アクリルとシリコーンとの複合樹脂の例としては、セラネートＷＳＡ１０６０、ＷＳＡ１０７０（ともに商品名、ＤＩＣ（株）製）、Ｈ７６２０、Ｈ７６３０、Ｈ７６５０（ともに商品名、旭化成ケミカルズ（株）製）等を挙げることができる。 (2) Binder The colored layer can contain at least one binder. When the binder is included, the amount is preferably in the range of 15% by mass to 200% by mass and more preferably in the range of 17% by mass to 100% by mass with respect to the pigment. When the amount of the binder is 15% by mass or more, the strength of the colored layer can be more favorably maintained, and when it is 200% by mass or less, the reflectance and decorativeness are prevented from being lowered.
As a binder suitable for the colored layer, for example, polyester, polyurethane, acrylic resin, polyolefin, or the like can be used. From the viewpoint of durability, the binder is preferably an acrylic resin or a polyolefin. As the acrylic resin, a composite resin of acrylic and silicone is also preferable. Examples of preferred binders include the following.
Examples of the polyolefin include Chemipearl S-120 and S-75N (both trade names, manufactured by Mitsui Chemicals, Inc.). Examples of the acrylic resin include Julimer ET-410 and SEK-301 (both trade names, manufactured by Nippon Pure Chemical Industries, Ltd.). Examples of the composite resin of acrylic and silicone include Ceranate WSA1060, WSA1070 (both trade names, manufactured by DIC Corporation), H7620, H7630, H7650 (both trade names, manufactured by Asahi Kasei Chemicals Corporation), and the like. Can do.
（３）添加剤
　着色層には、バインダー及び顔料以外に、必要に応じて、さらに架橋剤、界面活性剤、フィラー等を添加してもよい。 (3) Additive In addition to the binder and the pigment, a crosslinking agent, a surfactant, a filler, and the like may be further added to the colored layer as necessary.
　架橋剤としては、エポキシ系、イソシアネート系、メラミン系、カルボジイミド系、オキサゾリン系等の架橋剤を挙げることができる。架橋剤の着色剤中における添加量は、着色層のバインダーあたり５質量％～５０質量％が好ましく、より好ましくは１０質量％～４０質量％である。架橋剤の添加量は、５質量％以上であることで良好な架橋効果が得られ、着色層の強度や接着性を高く維持することができ、また５０質量％以下であることで、塗布液のポットライフをより長く維持することができる。 Examples of the crosslinking agent include epoxy-based, isocyanate-based, melamine-based, carbodiimide-based, and oxazoline-based crosslinking agents. The addition amount of the crosslinking agent in the colorant is preferably 5% by mass to 50% by mass and more preferably 10% by mass to 40% by mass with respect to the binder of the colored layer. When the addition amount of the crosslinking agent is 5% by mass or more, a good crosslinking effect can be obtained, the strength and adhesiveness of the colored layer can be maintained high, and when it is 50% by mass or less, the coating solution The pot life can be maintained longer.
　界面活性剤としては、アニオン系やノニオン系等の公知の界面活性剤を利用することができる。界面活性剤の添加量は、０．１ｍｇ／ｍ２～１５ｍｇ／ｍ２が好ましく、より好ましくは０．５ｍｇ／ｍ２～５ｍｇ／ｍ２が好ましい。界面活性剤の添加量は、０．１ｍｇ／ｍ２以上であることでハジキの発生が効果的に抑制され、また、１５ｍｇ／ｍ２以下であることで接着性に優れる。 As the surfactant, a known surfactant such as an anionic or nonionic surfactant can be used. The addition amount of the surfactant is preferably 0.1 mg / m 2 to 15 mg / m 2 , more preferably 0.5 mg / m 2 to 5 mg / m 2 . The amount of the surfactant added is 0.1 mg / m 2 or more to effectively suppress the occurrence of repelling, and the amount added is 15 mg / m 2 or less to provide excellent adhesion.
　さらに、着色層には、上記の顔料とは別に、シリカ等のフィラーなどを添加してもよい。フィラーの添加量は、着色層のバインダーあたり２０質量％以下が好ましく、より好ましくは１５質量％以下である。フィラーを含むことにより、着色層の強度を高めることができる。また、フィラーの添加量が２０質量％以下であることで、顔料の比率が保てるため、良好な光反射性（反射率）や装飾性が得られる。 Furthermore, a filler such as silica may be added to the colored layer in addition to the above pigment. The addition amount of the filler is preferably 20% by mass or less, more preferably 15% by mass or less per binder of the colored layer. By including the filler, the strength of the colored layer can be increased. Moreover, since the ratio of a pigment can be maintained because the addition amount of a filler is 20 mass% or less, favorable light reflectivity (reflectance) and decorativeness are obtained.
（４）着色層の形成方法
　着色層の形成方法としては、顔料を含有するポリマーシートをポリエステルフィルムに貼合する方法、ポリエステルフィルム成形時に着色層を共押出しする方法、塗布による方法等がある。このうち、塗布による方法は、簡便でかつ均一性の高い薄膜での形成が可能である点で好ましい。塗布方法としては、例えば、グラビアコーターやバーコーターなどの公知の方法を利用することができる。塗布に用いられる塗布液の溶媒としては、水でもよいし、トルエンやメチルエチルケトンのような有機溶媒でもよい。しかし、環境負荷の観点から、水を溶媒とすることが好ましい。
　溶媒は、１種類を単独で用いてもよいし、２種類以上を混合して用いてもよい。 (4) Forming method of colored layer As a forming method of the colored layer, there are a method of pasting a polymer sheet containing a pigment on a polyester film, a method of co-extruding a colored layer at the time of forming a polyester film, a method by coating, and the like. Among these, the method by coating is preferable in that it can be formed with a simple and highly uniform thin film. As a coating method, for example, a known method such as a gravure coater or a bar coater can be used. The solvent of the coating solution used for coating may be water or an organic solvent such as toluene or methyl ethyl ketone. However, from the viewpoint of environmental burden, it is preferable to use water as a solvent.
A solvent may be used individually by 1 type and may be used in mixture of 2 or more types.
（５）物性
　着色層は、白色顔料を含有して反射層として構成されることが好ましい。反射層である場合の５５０ｎｍの光反射率としては、７５％以上であるのが好ましい。反射率が７５％以上であると、太陽電池セルを素通りして発電に使用されなかった太陽光をセルに戻すことができ、発電効率を上げる効果が高い。 (5) Physical properties The colored layer preferably contains a white pigment and is configured as a reflective layer. The light reflectance at 550 nm in the case of the reflective layer is preferably 75% or more. When the reflectance is 75% or more, sunlight that has passed through the solar battery cell and has not been used for power generation can be returned to the cell, and the effect of increasing power generation efficiency is high.
　反射層の厚みは、１μｍ～２０μｍが好ましく、より好ましくは１．５μｍ～１０μｍ程度である。膜厚が１μｍ以上である場合、必要な装飾性や反射率が得られやすく、２０μｍ以下であると面状が悪化する場合がある。 The thickness of the reflective layer is preferably 1 μm to 20 μm, more preferably about 1.5 μm to 10 μm. When the film thickness is 1 μm or more, necessary decoration and reflectance are easily obtained, and when it is 20 μm or less, the surface shape may be deteriorated.
－下塗り層－
　ポリエステルフィルムには、下塗り層を設けることができる。下塗り層は、例えば、着色層が設けられるときには、着色層とポリエステルフィルムとの間に下塗り層を設けてもよい。下塗り層は、バインダー、架橋剤、界面活性剤等を用いて構成することができる。 -Undercoat layer-
An undercoat layer can be provided on the polyester film. For example, when a colored layer is provided, the undercoat layer may be provided between the colored layer and the polyester film. The undercoat layer can be formed using a binder, a crosslinking agent, a surfactant, and the like.
　下塗り層中に含有するバインダーとしては、ポリエステル、ポリウレタン、アクリル樹脂、ポリオレフィン等が挙げられる。下塗り層には、バインダー以外にエポキシ系、イソシアネート系、メラミン系、カルボジイミド系、オキサゾリン系等の架橋剤、アニオン系やノニオン系等の界面活性剤、シリカ等のフィラーなどを添加してもよい。 Examples of the binder contained in the undercoat layer include polyester, polyurethane, acrylic resin, and polyolefin. In addition to the binder, an epoxy, isocyanate, melamine, carbodiimide, oxazoline, or other crosslinking agent, anionic or nonionic surfactant, silica or other filler may be added to the undercoat layer.
　下塗り層を塗布形成するための方法や用いる塗布液の溶媒には、特に制限はない。
　塗布方法としては、例えば、グラビアコーターやバーコーターを利用することができる。前記溶媒は、水でもよいし、トルエンやメチルエチルケトンのような有機溶媒でもよい。溶媒は、１種類を単独で用いてもよいし、２種類以上を混合して用いてもよい。 There are no particular restrictions on the method for coating the undercoat layer and the solvent of the coating solution used.
As a coating method, for example, a gravure coater or a bar coater can be used. The solvent may be water or an organic solvent such as toluene or methyl ethyl ketone. A solvent may be used individually by 1 type and may be used in mixture of 2 or more types.
　塗布は、２軸延伸した後のポリエステルフィルムに塗布してもよいし、１軸延伸後のポリエステルフィルムに塗布してもよい。この場合、塗布後に初めの延伸と異なる方向に更に延伸してフィルムとしてもよい。さらに、延伸前のポリエステルフィルムに塗布した後に、２方向に延伸してもよい。
　下塗り層の厚みは、０．０５μｍ～２μｍが好ましく、より好ましくは０．１μｍ～１．５μｍ程度の範囲が好ましい。膜厚が０．０５μｍ以上であることで必要な接着性が得られやすく、２μｍ以下であることで、面状を良好に維持することができる。 Coating may be applied to a polyester film after biaxial stretching, it may be applied to a polyester film after uniaxial stretching. In this case, the film may be further stretched in a direction different from the initial stretching after coating. Furthermore, you may extend | stretch in 2 directions, after apply | coating to the polyester film before extending | stretching.
The thickness of the undercoat layer is preferably 0.05 μm to 2 μm, more preferably about 0.1 μm to 1.5 μm. When the film thickness is 0.05 μm or more, the necessary adhesiveness is easily obtained, and when it is 2 μm or less, the surface shape can be favorably maintained.
－フッ素系樹脂層・Ｓｉ系樹脂層－
　ポリエステルフィルムには、フッ素系樹脂層及びＳｉ系樹脂層の少なくとも一方を設けることが好ましい。フッ素系樹脂層やＳｉ系樹脂層を設けることで、ポリエステル表面の汚れ防止、耐候性向上が図れる。具体的には、特開２００７－３５６９４号公報、特開２００８－２８２９４号公報、ＷＯ２００７／０６３６９８号明細書に記載のフッ素樹脂系塗布層を有していることが好ましい。
　また、テドラー（商品名、ＤｕＰｏｎｔ社製）等のフッ素系樹脂フィルムを張り合わせることも好ましい。 -Fluorine resin layer / Si resin layer-
It is preferable to provide at least one of a fluorine-type resin layer and a Si-type resin layer in a polyester film. By providing the fluorine-based resin layer or the Si-based resin layer, it is possible to prevent contamination of the polyester surface and improve weather resistance. Specifically, it is preferable to have a fluororesin-based coating layer described in JP-A-2007-35694, JP-A-2008-28294, and WO2007 / 063698.
Moreover, it is also preferable to stick together fluorine resin films such as Tedlar (trade name, manufactured by DuPont).
　フッ素系樹脂層及びＳｉ系樹脂層の厚みは、各々、１μｍ～５０μｍの範囲が好ましく、より好ましくは３μｍ～４０μｍの範囲である。 The thickness of each of the fluorine-based resin layer and the Si-based resin layer is preferably in the range of 1 μm to 50 μm, more preferably in the range of 3 μm to 40 μm.
－無機層－
　ポリエステルフィルムには、無機層が設けられることも好ましい。
　無機層を設けることで、ポリエステルへの水やガスの浸入を防止する、防湿層やガスバリア層として機能を与えることができる。無機層は、ポリエステルフィルムの表裏いずれに設けてもよいが、防水、防湿等の観点から、ポリエステルフィルムの電池側基板と対向する側（着色層や易接着層の形成面側）とは反対側に好適に設けられる。 -Inorganic layer-
It is also preferable that the polyester film is provided with an inorganic layer.
By providing the inorganic layer to prevent ingress of water or gas into the polyester, it is possible to provide a function as a vapor barrier and gas barrier layer. The inorganic layer may be provided on either the front or back side of the polyester film, but from the viewpoint of waterproofing, moisture proofing, etc., the side opposite to the battery side substrate of the polyester film (the side on which the colored layer or easy adhesion layer is formed) Are preferably provided.
　無機層の水蒸気透過量（透湿度）は、１００ｇ／ｍ２・ｄ～１０－６ｇ／ｍ２・ｄが好ましく、より好ましくは１０-１ｇ／ｍ２・ｄ～１０－５ｇ／ｍ２・ｄであり、さらに好ましくは１０-２ｇ／ｍ２・ｄ～１０－４ｇ／ｍ２・ｄである。
　このような透湿度を有する無機層を形成するには、以下のような乾式法が好ましく用いられる。 The water vapor transmission rate (moisture permeability) of the inorganic layer is preferably 10 0 g / m 2 · d to 10 -6 g / m 2 · d, more preferably 10 -1 g / m 2 · d to 10 -5 g. / M 2 · d, and more preferably 10 -2 g / m 2 · d to 10 -4 g / m 2 · d.
In order to form an inorganic layer having such moisture permeability, the following dry method is preferably used.
　乾式法によりガスバリア性の無機層（以下、ガスバリア層ともいう。）を形成する方法としては、抵抗加熱蒸着、電子ビーム蒸着、誘導加熱蒸着、及びこれらにプラズマやイオンビームによるアシスト法などの真空蒸着法、反応性スパッタリング法、イオンビームスパッタリング法、ＥＣＲ（電子サイクロトロン）スパッタリング法などのスパッタリング法、イオンプレーティング法などの物理的気相成長法（ＰＶＤ法）、熱や光、プラズマなどを利用した化学的気相成長法（ＣＶＤ法）などが挙げられる。中でも、真空下で蒸着法により膜形成する真空蒸着法が好ましい。 As a method of forming a gas barrier inorganic layer (hereinafter also referred to as a gas barrier layer) by a dry method, resistance heating vapor deposition, electron beam vapor deposition, induction heat vapor deposition, and vacuum vapor deposition such as an assist method using plasma or ion beam for these. , Reactive sputtering method, ion beam sputtering method, sputtering method such as ECR (electron cyclotron) sputtering method, physical vapor deposition method such as ion plating method (PVD method), heat, light, plasma, etc. Examples include chemical vapor deposition (CVD). Among these, a vacuum vapor deposition method in which a film is formed by a vapor deposition method under vacuum is preferable.
　ここで、ガスバリア層を形成する材料が無機酸化物、無機窒化物、無機酸窒化物、無機ハロゲン化物、無機硫化物などを主たる構成成分とする場合は、形成するガスバリア層の組成と同一の材料を直接揮発させて基材などに堆積させることも可能であるが、この方法で行なう場合には、揮発中に組成が変化し、その結果、形成された膜が均一な特性を呈さない場合がある。そのため、１）揮発源として形成するバリア層と同一組成の材料を用い、無機酸化物の場合は酸素ガスを、無機窒化物の場合は窒素ガスを、無機酸窒化物の場合は酸素ガスと窒素ガスの混合ガスを、無機ハロゲン化物の場合はハロゲン系ガスを、無機硫化物の場合は硫黄系ガスを、それぞれ系内に補助的に導入しながら揮発させる方法、２）揮発源として無機物群を用い、これを揮発させながら、無機酸化物の場合は酸素ガスを、無機窒化物の場合は窒素ガスを、無機酸窒化物の場合は酸素ガスと窒素ガスの混合ガスを、無機ハロゲン化物の場合はハロゲン系ガスを、無機硫化物の場合は硫黄系ガスを、それぞれ系内に導入し、無機物と導入したガスを反応させながら基材表面に堆積させる方法、３）揮発源として無機物群を用い、これを揮発させて、無機物群の層を形成させた後、それを無機酸化物の場合は酸素ガス雰囲気下、無機窒化物の場合は窒素ガス雰囲気下、無機酸窒化物の場合は酸素ガスと窒素ガスの混合ガス雰囲気下、無機ハロゲン化物の場合はハロゲン系ガス雰囲気下、無機硫化物の場合は硫黄系ガス雰囲気下で保持することにより無機物層と導入したガスを反応させる方法、等が挙げられる。
　これらのうち、揮発源から揮発させることが容易であるという点で、２）又は３）がより好ましく用いられる。さらには、膜質の制御が容易である点で２）の方法が更に好ましく用いられる。また、バリア層が無機酸化物の場合は、揮発源として無機物群を用い、これを揮発させて、無機物群の層を形成させた後、空気中で放置することで、無機物群を自然酸化させる方法も、形成が容易であるという点で好ましい。 Here, when the material forming the gas barrier layer is mainly composed of inorganic oxide, inorganic nitride, inorganic oxynitride, inorganic halide, inorganic sulfide, etc., the same material as the composition of the gas barrier layer to be formed It is possible to directly volatilize and deposit it on a substrate or the like. However, when this method is used, the composition changes during volatilization, and as a result, the formed film may not exhibit uniform characteristics. is there. Therefore, 1) a material having the same composition as the barrier layer formed as a volatilization source is used, oxygen gas in the case of inorganic oxide, nitrogen gas in the case of inorganic nitride, oxygen gas and nitrogen in the case of inorganic oxynitride A method of volatilizing a mixed gas of gases by introducing a halogen-based gas in the case of an inorganic halide, and a sulfur-based gas in the case of an inorganic sulfide, while supplementarily introducing them into the system, and 2) selecting an inorganic group as a volatile source Volatilizes and vaporizes this, in the case of inorganic oxide, oxygen gas, in the case of inorganic nitride, nitrogen gas, in the case of inorganic oxynitride, mixed gas of oxygen gas and nitrogen gas, in the case of inorganic halide Is a method in which halogen gas is introduced into the system, and in the case of inorganic sulfides, sulfur gas is introduced into the system, and the inorganic material and the introduced gas are reacted and deposited on the substrate surface. 3) An inorganic group is used as a volatile source. And this After forming an inorganic group layer, it is an oxygen gas atmosphere in the case of an inorganic oxide, a nitrogen gas atmosphere in the case of an inorganic nitride, and an oxygen gas and a nitrogen gas in the case of an inorganic oxynitride. Examples of the method include a method of reacting an introduced gas with an inorganic layer by holding in a mixed gas atmosphere, a halogen-based gas atmosphere in the case of an inorganic halide, and a sulfur-based gas atmosphere in the case of an inorganic sulfide.
Among these, 2) or 3) is more preferably used because it is easy to volatilize from a volatile source. Furthermore, the method 2) is more preferably used because the film quality can be easily controlled. When the barrier layer is an inorganic oxide, the inorganic group is used as a volatilization source, volatilized to form an inorganic group layer, and then left in the air to naturally oxidize the inorganic group. The method is also preferable because it is easy to form.
　また、アルミ箔を貼り合わせてバリア層として使用することも好ましい。厚みは、１μｍ～３０μｍが好ましい。厚みは、１μｍ以上であると、経時（サーモ）中にポリエステルフィルム中に水が浸透し難くなって加水分解を生じ難く、３０μｍ以下であると、バリア層の厚みが厚くなり過ぎず、バリア層の応力でフィルムにベコが発生することもない。 It is also preferable to use aluminum foil as a barrier layer by bonding. The thickness is preferably 1 μm to 30 μm. When the thickness is 1 μm or more, water hardly penetrates into the polyester film during the lapse of time (thermo) and hardly causes hydrolysis, and when it is 30 μm or less, the thickness of the barrier layer does not become too thick, and the barrier layer The stress does not cause the film to bend.
　上記において、本発明のポリエステル樹脂組成物は、特に、耐候性が求められる屋外用途のポリエステルフィルム又はポリエステルシートとして好適に用いられる。屋外用途のポリエステルフィルム又はポリエステルシートとしては、例えば、太陽電池発電モジュールに備えられるバックシート（太陽光が入射する側と反対側に配されて太陽電池素子を保護する裏面保護用のシート）、照明用フィルム、農業用シートなどが挙げられ、特に太陽電池発電モジュールに備えられるバックシートとして好適である。 In the above, the polyester resin composition of the present invention is particularly suitably used as a polyester film or a polyester sheet for outdoor use that requires weather resistance. As a polyester film or polyester sheet for outdoor use, for example, a back sheet provided in a solar cell power generation module (a sheet for protecting the back surface that is disposed on the side opposite to the side on which sunlight is incident to protect the solar cell element), lighting Film, agricultural sheet, and the like, and particularly suitable as a back sheet provided in a solar cell power generation module.
＜太陽電池発電モジュール＞
　本発明の太陽電池発電モジュールは、既述の本発明のポリエステルフィルムの製造方法により得られたポリエステルフィルム（バックシートを含む）を備えたものである。好ましくは更に、太陽光が入射する側の透明性の基板（例：ガラス基板など）、太陽光の光エネルギーを電気エネルギーに変換する太陽電池素子、太陽電池素子を封止する封止剤などを用いて構成される。
　本発明のポリエステルフィルムの製造方法により得られたポリエステルフィルムをバックシートに適用するときは、バックシートは、太陽電池素子の表面のうち、透明性の基板が配される側と反対側に設けられる。 <Solar cell power generation module>
The solar cell power generation module of the present invention includes a polyester film (including a back sheet) obtained by the above-described method for producing a polyester film of the present invention. Preferably, further, a transparent substrate on which sunlight is incident (eg, a glass substrate), a solar cell element that converts light energy of sunlight into electric energy, a sealing agent that seals the solar cell element, and the like Constructed using.
When the polyester film obtained by the method for producing a polyester film of the present invention is applied to a back sheet, the back sheet is provided on the side of the solar cell element opposite to the side on which the transparent substrate is disposed. .
　太陽電池素子としては、単結晶シリコン、多結晶シリコン、アモルファスシリコンなどのシリコン系、銅－インジウム－ガリウム－セレン、銅－インジウム－セレン、カドミウム－テルル、ガリウム－砒素などのIII－V族やII－VI族化合物半導体系など、各種公知の太陽電池素子を適用することができる。 Solar cell elements include silicon-based materials such as single crystal silicon, polycrystalline silicon, and amorphous silicon, III-V groups such as copper-indium-gallium-selenium, copper-indium-selenium, cadmium-tellurium, gallium-arsenic, and II Various known solar cell elements such as a group VI compound semiconductor can be applied.
　以下、本発明を実施例により更に具体的に説明するが、本発明はその主旨を越えない限り、以下の実施例に限定されるものではない。なお、特に断りのない限り、「部」および「％」は質量基準である。 Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples as long as the gist thereof is not exceeded. Unless otherwise specified, “part” and “%” are based on mass.
（実施例１）
１．ポリエステルの製造（固相重合工程）
－重合（エステル化反応）－
［工程（Ａ）］
　第一エステル化反応槽に、高純度テレフタル酸４．７トンとエチレングリコール１．８トンを９０分かけて混合してスラリー形成させ、３８００ｋｇ／ｈの流量で連続的に第一エステル化反応槽に供給した。更にクエン酸がＴｉ金属に配位したクエン酸キレートチタン錯体（ＶＥＲＴＥＣ ＡＣ－４２０、商品名、ジョンソン・マッセイ社製）のエチレングリコール溶液を連続的に供給し、反応槽内温度２５０℃、攪拌下で平均滞留時間を約４．３時間として反応を行なった。このとき、クエン酸キレートチタン錯体は、Ｔｉ添加量が元素換算値で９ｐｐｍとなるように連続的に添加した。このとき、得られたオリゴマーの酸価は６００ｅｑ／トンであった。 Example 1
1. Production of polyester (solid phase polymerization process)
-Polymerization (esterification reaction)-
[Step (A)]
In the first esterification reactor, 4.7 tons of high-purity terephthalic acid and 1.8 tons of ethylene glycol are mixed for 90 minutes to form a slurry, and continuously at a flow rate of 3800 kg / h. Supplied to. Further, an ethylene glycol solution of a citric acid chelate titanium complex (VERTEC AC-420, trade name, manufactured by Johnson Matthey) in which citric acid is coordinated to Ti metal is continuously supplied, and the temperature in the reaction vessel is 250 ° C. with stirring. The reaction was carried out with an average residence time of about 4.3 hours. At this time, the citric acid chelate titanium complex was continuously added so that the amount of Ti added was 9 ppm in terms of element. At this time, the acid value of the obtained oligomer was 600 eq / ton.
　この反応物を第二エステル化反応槽に移送し、攪拌下、反応槽内温度２５０℃で、平均滞留時間で１．２時間反応させ、酸価が２００ｅｑ／ｔｏｎのオリゴマーを得た。第二エステル化反応槽は内部が３ゾーンに仕切られており、第２ゾーンから酢酸マグネシウムのエチレングリコール溶液を、Ｍｇ添加量が元素換算値で７５ｐｐｍになるように連続的に供給し、続いて第３ゾーンから、リン酸トリメチルのエチレングリコール溶液を、Ｐ添加量が元素換算値で６５ｐｐｍになるように連続的に供給した。
　以上により、エステル化反応生成物を得た。このとき、Ｔｉ／Ｐ（Ｔｉ及びＰの元素含有量比）は、０．１４であった。 This reaction product was transferred to a second esterification reaction vessel, and reacted with stirring at a temperature in the reaction vessel of 250 ° C. and an average residence time of 1.2 hours to obtain an oligomer having an acid value of 200 eq / ton. The inside of the second esterification reaction tank is partitioned into three zones, and an ethylene glycol solution of magnesium acetate is continuously supplied from the second zone so that the amount of Mg added is 75 ppm in terms of element, From the third zone, an ethylene glycol solution of trimethyl phosphate was continuously supplied so that the added amount of P was 65 ppm in terms of element.
As a result, an esterification reaction product was obtained. At this time, Ti / P (element content ratio of Ti and P) was 0.14.
　なお、リン酸トリメチルのエチレングリコール溶液は、２５℃のエチレングリコール液に、２５℃のリン酸トリメチル液を加え、２５℃で２時間攪拌することにより調製した（溶液中のリン化合物含有量：３．８％）。 The ethylene glycol solution of trimethyl phosphate was prepared by adding a 25 ° C. trimethyl phosphate solution to a 25 ° C. ethylene glycol solution and stirring at 25 ° C. for 2 hours (phosphorus compound content in the solution: 3 .8%).
［工程（Ｂ）］
　工程（Ａ）で得られたエステル化反応生成物を連続的に第一重縮合反応槽に供給し、攪拌下、反応温度２７０℃、反応槽内圧力２０ｔｏｒｒ（２．６７×１０－３ＭＰａ）で、平均滞留時間を約１．８時間として重縮合（エステル交換反応）させた。 [Step (B)]
The esterification reaction product obtained in the step (A) is continuously supplied to the first polycondensation reaction tank, and with stirring, the reaction temperature is 270 ° C. and the reaction tank pressure is 20 torr (2.67 × 10 −3 MPa). The polycondensation (transesterification reaction) was carried out with an average residence time of about 1.8 hours.
　更に、この反応物を、第一重縮合反応槽から第二重縮合反応槽に移送し、この反応槽において攪拌下、反応槽内温度２７６℃、反応槽内圧力５ｔｏｒｒ（６．６７×１０－４ＭＰａ）で滞留時間を約１．２時間の条件として反応（エステル交換反応）させた。 Further, the reaction, from the first condensation polymerization reactor tank was transferred to a second condensation polymerization reactor tank, stirring in the reaction vessel, the reaction vessel temperature 276 ° C., the reaction vessel pressure 5torr (6.67 × 10 - 4 MPa), and the reaction (transesterification reaction) was carried out under the condition that the residence time was about 1.2 hours.
　次いで、この反応物を、第二重縮合反応槽から更に第三重縮合反応槽に移送し、この反応槽では、反応槽内温度２７８℃、反応槽内圧力１．５ｔｏｒｒ（２．０×１０－４ＭＰａ）で、滞留時間１．５時間の条件で反応（エステル交換反応）させ、重縮合物（ポリエチレンテレフタレート（ＰＥＴ））を得た。 Next, this reaction product was further transferred from the second double condensation reaction tank to the third triple condensation reaction tank. In this reaction tank, the reaction vessel internal temperature was 278 ° C. and the reaction vessel internal pressure was 1.5 torr (2.0 × 10 6 -4 MPa) at a residence time of 1.5 hours (transesterification reaction) to obtain a polycondensate (polyethylene terephthalate (PET)).
　次に、得られた重縮合物（ＰＥＴ）を冷水にストランド状に吐出し、直ちにカッティングしてＰＥＴペレット１（断面：長径約４ｍｍ、短径約２．４ｍｍ、長さ：約３ｍｍ）とした。 Next, the obtained polycondensate (PET) was discharged into cold water in a strand shape, and immediately cut into PET pellets 1 (cross section: major axis: about 4 mm, minor axis: about 2.4 mm, length: about 3 mm). .
　ＰＥＴペレット１について、末端ＣＯＯＨ量（ＡＶ）〔ｅｑ／ｔｏｎ〕と、固有粘度（ＩＶ）〔ｄｌ/ｇ〕を測定した。
　末端ＣＯＯＨ量は、H. A. Pohl, Anal. Chem. 26 (1954) 2145に記載の方法にしたがって、滴定法にて末端ＣＯＯＨ量を測定した。具体的には、ＰＥＴペレット１をベンジルアルコールに２０５℃で溶解し、フェノールレッド指示薬を加え、水酸化ナトリウムの水／メタノール／ベンジルアルコール溶液で滴定し、その適定量から末端ＣＯＯＨ量を算出した。
　ＰＥＴペレット１の〔ｄｌ／ｇ〕は、ＰＥＴペレット１を、１，１，２，２－テトラクロルエタン／フェノール（＝２／３[質量比]）混合溶媒に溶解し、混合溶媒中の３０℃での溶液粘度から求めた。
　固相重合前のＰＥＴペレット１の固有粘度と末端ＣＯＯＨ量を表１の「固相重合前」「樹脂」「ＩＶ」欄及び「ＡＶ」欄に示す。 About the PET pellet 1, the amount of terminal COOH (AV) [eq / ton] and the intrinsic viscosity (IV) [dl / g] were measured.
The amount of terminal COOH was determined by titration according to the method described in H. A. Pohl, Anal. Chem. 26 (1954) 2145. Specifically, PET pellet 1 was dissolved in benzyl alcohol at 205 ° C., phenol red indicator was added, titrated with a water / methanol / benzyl alcohol solution of sodium hydroxide, and the amount of terminal COOH was calculated from the appropriate amount.
[Dl / g] of the PET pellet 1 is obtained by dissolving the PET pellet 1 in a mixed solvent of 1,1,2,2-tetrachloroethane / phenol (= 2/3 [mass ratio]). It calculated | required from the solution viscosity in ° C.
The intrinsic viscosity and the amount of terminal COOH of the PET pellet 1 before solid phase polymerization are shown in “Before solid phase polymerization”, “Resin”, “IV” column and “AV” column of Table 1.
－加熱（結晶化）－
　図１に示す構成の結晶化装置を用意し、結晶化装置上部の開口部（開口部８）から、ＰＥＴペレット１を、投入量３００ｋｇ／ｈｒで投入すると共に、結晶化装置に１８０℃の窒素ガスを、供給量２００Ｎｍ３／ｈｒで供給した。また、窒素ガスの風速（空塔速度）は、１．０ｍ／ｓｅｃとした。結晶化装置の下部に落下したＰＥＴペレット１は、結晶化装置が内蔵する循環装置によって、繰り返し開口部（開口部８）まで持ち上げ、落下させることで、４時間かけて加熱（結晶化）した。
　結晶化されたＰＥＴペレット１を１００粒用意し、それぞれについて、結晶化度ρを既述の計算式〔結晶化度ρ（％）＝｛（ｄ－ｄＡ）／（ｄＣ－ｄＡ）｝×１００〕により算出した。得られた結晶化度ρの平均値を、表１の「結晶化後の樹脂」「ρ」欄に示す。また、得られた結晶化度ρの分布Δρを「Δρ」欄に示した。 -Heating (crystallization)-
A crystallization apparatus having the structure shown in FIG. 1 is prepared, and PET pellets 1 are charged at an input amount of 300 kg / hr from an opening (opening 8) at the top of the crystallization apparatus, and nitrogen at 180 ° C. is supplied to the crystallization apparatus. The gas was supplied at a supply rate of 200 Nm 3 / hr. Moreover, the wind speed (superficial velocity) of nitrogen gas was 1.0 m / sec. The PET pellet 1 dropped on the lower part of the crystallizer was heated (crystallized) for 4 hours by repeatedly lifting it up to the opening (opening 8) and dropping it with a circulation device built in the crystallizer.
100 grains of crystallized PET pellets 1 were prepared, and for each, the crystallinity ρ was calculated as described above [crystallinity ρ (%) = {(d−dA) / (dC−dA)} × 100. ] Was calculated. The average value of the obtained crystallinity ρ is shown in the “resin after crystallization” and “ρ” columns in Table 1. Further, the distribution Δρ of the obtained crystallinity ρ is shown in the “Δρ” column.
　また、結晶化されたＰＥＴペレット１、１００粒について、Ｃｕ－Ｋα１線を用いたＸ線回折解析により、既述のＳｃｈｅｒｒｅｒの式を用いて、結晶子径Ｄを測定した。Ｘ線回折解析装置は、リガク社製ＵＬＴＩＭＡ ＩＶを用いた。
　得られた結晶子径Ｄの平均値を、表１の「結晶化後の樹脂」「Ｄ」欄に示した。また、得られた結晶子径Ｄの分布ΔＤを「ΔＤ」欄に示した。 The crystallite diameter D of 100 crystallized PET pellets was measured by X-ray diffraction analysis using Cu—Kα1 line, using the Scherrer equation described above. As the X-ray diffraction analyzer, ULTIMA IV manufactured by Rigaku Corporation was used.
The average value of the obtained crystallite diameters D is shown in the “resin after crystallization” and “D” columns in Table 1. Further, the distribution ΔD of the obtained crystallite diameter D is shown in the “ΔD” column.
－固相重合－
　結晶化されたＰＥＴペレット１を用いて、回転型真空重合装置を用いて、５０Ｐａの減圧下、１８０℃で６０時間の加熱処理を行なった。このとき、固有粘度が０．１上昇した際の末端ＣＯＯＨ濃度の減少量は、１．５ｅｑ／ｔｏｎであった。なお、測定は、以下に示す方法により行なった。
　その後、真空重合装置内に２５℃の窒素ガスを流し、ＰＥＴペレット１を２５℃まで冷却し、固相重合されたＰＥＴペレット１を得た。 -Solid state polymerization-
The crystallized PET pellet 1 was subjected to a heat treatment at 180 ° C. for 60 hours under a reduced pressure of 50 Pa using a rotary vacuum polymerization apparatus. At this time, the amount of decrease in the terminal COOH concentration when the intrinsic viscosity increased by 0.1 was 1.5 eq / ton. The measurement was performed by the following method.
Thereafter, nitrogen gas at 25 ° C. was flowed into the vacuum polymerization apparatus, and the PET pellet 1 was cooled to 25 ° C. to obtain a solid-state polymerized PET pellet 1.
２．ポリエステルフィルムの製造（押出成形工程）
－押出成形－
　上記のように固相重合を終えたＰＥＴペレット１を、含水率２０ｐｐｍ以下に乾燥させた後、直径５０ｍｍの１軸混練押出し基のホッパーに投入し、２７０℃で溶融して押出した。
　押出機内の圧力変動を観察したところ、０．８％であった。結果を表１の「押出成形」「押出機の圧力変動」欄に示した。 2. Production of polyester film (extrusion process)
-Extrusion molding-
The PET pellet 1 after the solid phase polymerization as described above was dried to a moisture content of 20 ppm or less, and then poured into a hopper of a uniaxial kneading extrusion base having a diameter of 50 mm, and melted and extruded at 270 ° C.
When the pressure fluctuation in the extruder was observed, it was 0.8%. The results are shown in the column of “Extrusion molding” and “Extruder pressure fluctuation” in Table 1.
　ＰＥＴペレット１の溶融体（メルト）をギアポンプ、濾過器（孔径２０μｍ）を通した後、ダイから２０℃の冷却ロールに押出し、厚み３５００μｍの非晶性シートを得た。なお、押出されたメルトは、静電印加法を用い冷却ロールに密着させた。 The melt (melt) of the PET pellet 1 was passed through a gear pump and a filter (pore diameter 20 μm), and then extruded from a die onto a 20 ° C. cooling roll to obtain an amorphous sheet having a thickness of 3500 μm. The extruded melt was brought into close contact with the cooling roll using an electrostatic application method.
－延伸－
　上記方法で冷却ロール上に押出し、固化した未延伸フィルムに対し、以下の方法で逐次２軸延伸を施し、厚み２５０μｍのポリエステルフィルムを得た。
　<延伸方法>
（ａ）縦延伸
　未延伸フィルムを周速の異なる２対のニップロールの間に通し、縦方向（搬送方向）に延伸した。なお、予熱温度を９５℃、延伸温度を９５℃、延伸倍率を３．５倍、延伸速度を３０００％／秒として実施した。
（ｂ）横延伸
　縦延伸した前記フィルムに対し、テンターを用いて下記条件にて横延伸した。
　<条件>
・予熱温度：１１０℃
・延伸温度：１２０℃
・延伸倍率：３．９倍
・延伸速度：７０％／秒 -Stretching-
The unstretched film extruded and solidified by the above method was successively biaxially stretched by the following method to obtain a polyester film having a thickness of 250 μm.
<Stretching method>
(A) Longitudinal stretching The unstretched film was passed between two pairs of nip rolls having different peripheral speeds and stretched in the longitudinal direction (conveying direction). The preheating temperature was 95 ° C., the stretching temperature was 95 ° C., the stretching ratio was 3.5 times, and the stretching speed was 3000% / second.
(B) Transverse stretching The longitudinally stretched film was stretched laterally under the following conditions using a tenter.
<Condition>
-Preheating temperature: 110 ° C
-Stretching temperature: 120 ° C
-Stretch ratio: 3.9 times-Stretch speed: 70% / second
－熱固定・熱緩和－
　続いて、縦延伸及び横延伸を終えた後の延伸フィルムを下記条件で熱固定した。さらに、熱固定した後、テンター幅を縮め下記条件で熱緩和した。
　<熱工程条件>
　・熱固定温度：２１５℃
　・熱固定時間：２秒
　<熱緩和条件>
　・熱緩和温度：２１０℃
　・熱緩和率：２％ -Heat fixation / thermal relaxation-
Then, the stretched film after finishing longitudinal stretching and lateral stretching was heat-set under the following conditions. Further, after heat setting, the tenter width was reduced and heat relaxation was performed under the following conditions.
<Thermal process conditions>
・ Heat setting temperature: 215 ℃
・ Heat setting time: 2 seconds <thermal relaxation conditions>
-Thermal relaxation temperature: 210 ° C
-Thermal relaxation rate: 2%
－巻き取り－
　熱固定及び熱緩和の後、両端を１０ｃｍずつトリミングした。その後、両端に幅１０ｍｍで押出し加工（ナーリング）を行なった後、張力２５ｋｇ／ｍで巻き取った。なお、幅は１．５ｍ、巻長は２０００ｍであった。
　以上のようにして、ポリエステルフィルム１を作製した。 -Winding-
After heat setting and heat relaxation, both ends were trimmed by 10 cm. Then, after extruding (knurling) with a width of 10 mm at both ends, it was wound up with a tension of 25 kg / m. The width was 1.5 m and the winding length was 2000 m.
The polyester film 1 was produced as described above.
３．ポリエステルフィルム評価
　上記のように得られたポリエステルフィルム１について、固有粘度（ＩＶ）、末端ＣＯＯＨ量（酸価、ＡＶ）、及び破断伸度半減時間（ｈｒ）を以下に示す方法により測定した。測定結果を下記表１に示す。 3. Evaluation of Polyester Film About the polyester film 1 obtained as described above, the intrinsic viscosity (IV), the terminal COOH amount (acid value, AV), and the elongation at break half time (hr) were measured by the following methods. The measurement results are shown in Table 1 below.
（ａ）末端ＣＯＯＨ量（ＡＶ）〔ｅｑ／ｔｏｎ〕
　得られたポリエステルフィルム１について、H. A. Pohl, Anal. Chem. 26 (1954) 2145に記載の方法にしたがって、滴定法にて末端ＣＯＯＨ量を測定した。
　具体的には、図２に示す要領で、得られたポリエステルフィルム１の長手方向に、２０個の測定位置（点Ｐ）をマークし（点Ｐ同士の間隔は、１００ｍ）、点Ｐが中心となるようにポリエステルフィルム１を裁断して、１ｃｍ×２０ｃｍの試料片を２０枚得た。次いで、　得られた試料片それぞれについて、試料片をベンジルアルコールに２０５℃で溶解し、フェノールレッド指示薬を加え、水酸化ナトリウムの水／メタノール／ベンジルアルコール溶液で滴定し、その適定量から末端ＣＯＯＨ量（ｅｑ／ｔｏｎ；＝ＡＶ）を算出した。
　算出された末端ＣＯＯＨ量の平均値を、表１の「フィルム」「ＡＶ」「平均」欄に示す。また、算出された末端ＣＯＯＨ量の平均値、最大値、及び最小値から、末端ＣＯＯＨ量のバラツキを算出し、「ＡＶ」「バラツキ」欄に示した。 (A) Amount of terminal COOH (AV) [eq / ton]
For the obtained polyester film 1, the amount of terminal COOH was measured by a titration method according to the method described in H. A. Pohl, Anal. Chem. 26 (1954) 2145.
Specifically, 20 measurement positions (points P) are marked in the longitudinal direction of the obtained polyester film 1 as shown in FIG. 2 (the interval between the points P is 100 m), and the point P is the center. The polyester film 1 was cut so that 20 pieces of 1 cm × 20 cm sample pieces were obtained. Next, for each of the obtained sample pieces, the sample piece was dissolved in benzyl alcohol at 205 ° C., phenol red indicator was added, and titrated with a water / methanol / benzyl alcohol solution of sodium hydroxide. (Eq / ton; = AV) was calculated.
The average value of the calculated amount of terminal COOH is shown in the “film”, “AV”, and “average” columns of Table 1. Further, the variation in the amount of terminal COOH was calculated from the calculated average value, maximum value, and minimum value of the terminal COOH amount, and indicated in the “AV” and “variation” columns.
（ｂ）ＩＶ〔ｄｌ/ｇ〕
　得られたポリエステルフィルム１について、１，１，２，２－テトラクロルエタン／フェノール（＝２／３[質量比]）混合溶媒中の３０℃での溶液粘度から求めた。 (B) IV [dl / g]
The obtained polyester film 1 was determined from the solution viscosity at 30 ° C. in a 1,1,2,2-tetrachloroethane / phenol (= 2/3 [mass ratio]) mixed solvent.
（ｃ）破断伸度半減時間［ｈｒ］
　末端ＣＯＯＨ量（ＡＶ）の測定と同様にして、２０枚の１ｃｍ×２０ｃｍの試料片を用意した。
　破断伸度半減時間は、用意した２０枚の試料片それぞれに対して、１２０℃、相対湿度１００％の条件で保存処理（加熱処理）を行ない、保存後の試料片が示す破断伸度［％］が、保存前の試料片が示す破断伸度［％］に対して５０％となる保存時間（破断伸度保持時間）を測定することにより評価した。
　破断伸度（％）は、試料片をチャック間５ｃｍ、２０％／分にて引っ張って求めた。
　破断伸度半減時間が長い程、ポリエステルフィルムの耐加水分解性に優れていることを示す。
　２０枚の試料片について測定した破断伸度半減時間の平均値を、表１の「フィルム」「破断伸度半減時間」「平均」欄に示す。また、２０枚の試料片について測定した破断伸度半減時間の最大値、及び最小値から、２０枚の試料片の破断伸度半減時間のバラツキを算出し、「破断伸度半減時間」「バラツキ」欄に示した。 (C) Half elongation at break [hr]
In the same manner as the measurement of the terminal COOH amount (AV), 20 1 cm × 20 cm sample pieces were prepared.
The breaking elongation half-time was determined by subjecting each of the 20 prepared sample pieces to a storage treatment (heating treatment) at 120 ° C. and a relative humidity of 100%. ] Was evaluated by measuring a storage time (breaking elongation retention time) of 50% with respect to the breaking elongation [%] exhibited by the sample piece before storage.
The elongation at break (%) was determined by pulling the sample piece at 5 cm between chucks at 20% / min.
It shows that it is excellent in the hydrolysis resistance of a polyester film, so that breaking elongation half time is long.
The average values of the breaking elongation half times measured for 20 sample pieces are shown in the “film”, “breaking elongation half time” and “average” columns of Table 1. Also, the variation in the half elongation at break of the 20 sample pieces was calculated from the maximum and minimum values of the half elongation at break measured for the 20 sample pieces, and the “half elongation at break” and “variation” were calculated. "Column.
（実施例２、実施例３）
　実施例１において、ＰＥＴペレット１の結晶化における窒素ガスの温度を１８０℃から表１に示す温度に変更し、ＰＥＴペレットの固相重合条件を表１に示すように変更したこと以外は、実施例１と同様にして、ポリエステルフィルム２、３を作製し、物性の評価を行なった。評価の結果は、下記表１に示す。 (Example 2, Example 3)
In Example 1, except that the temperature of nitrogen gas in the crystallization of the PET pellet 1 was changed from 180 ° C. to the temperature shown in Table 1, and the solid phase polymerization conditions of the PET pellet were changed as shown in Table 1. In the same manner as in Example 1, polyester films 2 and 3 were prepared, and physical properties were evaluated. The results of evaluation are shown in Table 1 below.
（実施例４）
　実施例２において、ＰＥＴペレット１に代えて固相重合前におけるＩＶ及びＡＶが異なるＰＥＴペレット２を用い、押出成形工程の押出機の圧力変動を表１に示すように変更した他は同様にして、ポリエステルフィルム４を作製し、物性の評価を行なった。評価の結果は、下記表１に示す。
　ＰＥＴペレット２は、次のようにして得た。 (Example 4)
In Example 2, instead of PET pellet 1, PET pellet 2 having different IV and AV before solid-phase polymerization was used, and the pressure fluctuation of the extruder in the extrusion molding process was changed as shown in Table 1, and the same manner was performed. A polyester film 4 was produced and evaluated for physical properties. The results of evaluation are shown in Table 1 below.
PET pellet 2 was obtained as follows.
－ＰＥＴペレット２の製造－
ＰＥＴペレット１の製造において、実施例１の「１．ポリエステルの製造」「工程（Ｂ）」における第一重縮合反応槽、第二重縮合反応槽、及び第三重縮合反応槽の各温度を５℃下げたこと以外は同様にして、ＰＥＴペレット２を作成した。
　得られたＰＥＴペレット２の固相重合前における固有粘度（ＩＶ）と末端ＣＯＯＨ量（ＡＶ）は、固相重合前のＰＥＴペレット１のＩＶ、ＡＶ測定と同様にして行なった。 -Production of PET pellet 2-
In the production of the PET pellet 1, each temperature of the first polycondensation reaction tank, the second double condensation reaction tank, and the third triple condensation reaction tank in “1. Production of polyester” and “Step (B)” in Example 1 is set. PET pellet 2 was prepared in the same manner except that the temperature was lowered by 5 ° C.
The intrinsic viscosity (IV) and terminal COOH amount (AV) before solid phase polymerization of the obtained PET pellet 2 were measured in the same manner as the IV and AV measurements of the PET pellet 1 before solid phase polymerization.
（実施例５～実施例７、及び比較例５）
　実施例２において、ＰＥＴペレット１の加熱（結晶化）における窒素ガスの空塔速度を表１に示す速度に代え、押出成形工程における押出機の圧力変動を表１に示すように変更した他は同様にして、ポリエステルフィルム５～７（実施例５～実施例７）、及びポリエステルフィルム１０５（比較例５）を作製し、物性を評価した。評価の結果は、下記表１に示す。 (Examples 5 to 7 and Comparative Example 5)
In Example 2, except that the superficial velocity of nitrogen gas in the heating (crystallization) of the PET pellet 1 was changed to the velocity shown in Table 1, and the pressure fluctuation of the extruder in the extrusion molding process was changed as shown in Table 1. Similarly, polyester films 5 to 7 (Examples 5 to 7) and a polyester film 105 (Comparative Example 5) were prepared and evaluated for physical properties. The results of evaluation are shown in Table 1 below.
（実施例８）
　実施例３において、ＰＥＴペレット１の加熱（結晶化）をホソカワミクロン社製、トーラスディスクプレヒーターを用いた金属接触による方法で行ない、ＰＥＴペレットの固相重合条件を表１に示すように変更した他は、同様にして、実施例８のポリエステルフィルム８を製造した。なお、金属接触による加熱温度及び加熱時間は、表１に示した。
　得られたポリエステルフィルム８について、実施例１のポリエステルフィルム１と同様にして測定、評価を行なった。測定、評価の結果は、下記表１に示す。 (Example 8)
In Example 3, the PET pellet 1 was heated (crystallized) by a metal contact method using a torus disk preheater manufactured by Hosokawa Micron Corporation, and the solid phase polymerization conditions of the PET pellet were changed as shown in Table 1. Produced a polyester film 8 of Example 8 in the same manner. The heating temperature and heating time by metal contact are shown in Table 1.
The obtained polyester film 8 was measured and evaluated in the same manner as the polyester film 1 of Example 1. The results of measurement and evaluation are shown in Table 1 below.
（比較例１～比較例４）
　実施例１～実施例４において、ＰＥＴペレットの加熱（結晶化）をホソカワミクロン社製、トーラスディスクプレヒーターを用いた金属接触による方法で行ない、ＰＥＴペレットの固相重合条件および押出成形工程における押出機の圧力変動を表１に示すように変更した他は、同様にして、それぞれ、比較例１～比較例４のポリエステルフィルム１０１～１０４を製造した。なお、金属接触による加熱温度及び加熱時間は、表１に示した。
　得られたポリエステルフィルム１０１～１０４について、実施例１のポリエステルフィルム１と同様にして測定、評価を行なった。測定、評価の結果は、下記表１に示す。 (Comparative Examples 1 to 4)
In Examples 1 to 4, the PET pellets were heated (crystallized) by a metal contact method using a torus disk preheater manufactured by Hosokawa Micron Corporation, and the solid phase polymerization conditions for the PET pellets and the extruder used in the extrusion process The polyester films 101 to 104 of Comparative Examples 1 to 4 were produced in the same manner except that the pressure fluctuation was changed as shown in Table 1. The heating temperature and heating time by metal contact are shown in Table 1.
The obtained polyester films 101 to 104 were measured and evaluated in the same manner as the polyester film 1 of Example 1. The results of measurement and evaluation are shown in Table 1 below.
（実施例９）
　実施例２において、ＰＥＴペレット１に代えて、ポリブチレンテレフタレート（ＰＢＴ）ペレットを用いた他は同様にして、実施例９のポリエステルフィルム９を作製し、物性の評価を行なった。評価の結果は、下記表１に示す。
　ＰＢＴペレットは、次のようにして得た。 Example 9
In Example 2, the polyester film 9 of Example 9 was produced in the same manner except that polybutylene terephthalate (PBT) pellets were used instead of the PET pellets 1, and physical properties were evaluated. The results of evaluation are shown in Table 1 below.
PBT pellets were obtained as follows.
－ＰＢＴペレットの製造－
　ＰＥＴペレット１の製造において、実施例１の「１．ポリエステルの製造」「工程（Ａ）」で用いた原料のうち、ジオール成分を、エチレングリコールから、１，４－ブタンジオールに変更したこと以外は同様にして、エステル化反応を進め、ＰＢＴ（ポリブチレンテレフタレート）ペレットを得た。
　得られたＰＢＴペレットの固相重合前における固有粘度（ＩＶ）と末端ＣＯＯＨ量（ＡＶ）は、固相重合前のＰＥＴペレット１のＩＶ、ＡＶ測定と同様にして行なった。 -Production of PBT pellets-
In the production of PET pellets 1, the diol component of the raw materials used in “1. Production of polyester” and “Step (A)” in Example 1 was changed from ethylene glycol to 1,4-butanediol. In the same manner, the esterification reaction was advanced to obtain PBT (polybutylene terephthalate) pellets.
The intrinsic viscosity (IV) and terminal COOH amount (AV) of the obtained PBT pellet before solid phase polymerization were measured in the same manner as the IV and AV measurements of the PET pellet 1 before solid phase polymerization.
　表１中、「固相重合」「樹脂」「種」に示す「ＰＥＴ１」は、ペレットとしてＰＥＴペレット１を用いていることを示し、「ＰＥＴ２」は、ペレットとしてＰＥＴペレット２を用いていることを示し、「ＰＢＴ」は、ペレットとしてＰＢＴペレットを用いていることを示す。 In Table 1, “PET1” shown in “solid phase polymerization”, “resin” and “seed” indicates that PET pellet 1 is used as a pellet, and “PET2” uses PET pellet 2 as a pellet. “PBT” indicates that PBT pellets are used as pellets.
Figure JPOXMLDOC01-appb-T000001
 
Figure JPOXMLDOC01-appb-T000001
 
　前記表１に示すように、実施例では、比較例に比べて、結晶化後のポリエステルの結晶化度分布Δρが大きく、押出機内での圧力変動が小さく、得られたポリエステルフィルムの末端ＣＯＯＨ量のバラツキや破断伸度半減時間のバラツキが小さくなっている。従って、結晶化後のポリエステルの結晶化度分布Δρが１５％以下の範囲で大きい方が、押出機内での圧力変動を抑制し、ポリエステルの末端ＣＯＯＨ量を小さくすると共に、末端ＣＯＯＨ量のバラツキや破断伸度半減時間のバラツキを抑制していることがわかった。 As shown in Table 1, in the examples, the crystallinity distribution Δρ of the polyester after crystallization is large and the pressure fluctuation in the extruder is small compared to the comparative example, and the terminal COOH amount of the obtained polyester film is small. And variations in half elongation time at break are small. Therefore, when the crystallinity distribution Δρ of the polyester after crystallization is larger in the range of 15% or less, pressure fluctuation in the extruder is suppressed, the amount of terminal COOH of the polyester is reduced, and variation in the amount of terminal COOH is reduced. It was found that variations in the half elongation time at break were suppressed.
〔実施例１０〕
４．太陽電池用ポリエステルフィルム（太陽電池用バックシート）の作製
　上記で作製した実施例１～実施例９のポリエステルフィルム１～９、および比較例１～比較例５のポリエステルフィルム１０１～１０５を用い、太陽電池に備えられるバックシート１～９、及び１０１～１０５を作製した。具体的には、以下の通りである。 Example 10
4). Production of polyester film for solar cell (back sheet for solar cell) Using the polyester films 1 to 9 of Examples 1 to 9 and the polyester films 101 to 105 of Comparative Examples 1 to 5 produced above, Back sheets 1 to 9 and 101 to 105 included in the battery were produced. Specifically, it is as follows.
　上記で作製したポリエステルフィルムの片面に、下記の（ｉ）反射層と（ii）易接着性層とをこの順で塗設した。 The following (i) reflective layer and (ii) easy-adhesion layer were coated in this order on one side of the polyester film produced above.
（ｉ）反射層（着色層）
　まず初めに、下記組成の諸成分を混合し、ダイノミル型分散機により１時間分散処理して顔料分散物を調製した。
　<顔料分散物の処方>
・二酸化チタン　　　　　　　　　　　　　　・・・３９．９部　　　　　　　　　　　（タイペークＲ－７８０－２、商品名、石原産業（株）製、固形分１００％）
・ポリビニルアルコール　　　　　　　　　　・・・・８．０部
（ＰＶＡ－１０５、商品名、（株）クラレ製、固形分１０％）
・界面活性剤　　　　　　　　　　　　　　　・・・・０．５部
（デモールＥＰ、商品名、花王（株）製、固形分：２５％）　　
・蒸留水　　　　　　　　　　　　　　　　　・・・５１．６部 (I) Reflective layer (colored layer)
First, by mixing the ingredients of the following composition, dispersion treatment for 1 hour to prepare a pigment dispersion by Dyno mill type disperser.
<Prescription of pigment dispersion>
・ Titanium dioxide 39.9 parts (Taipaque R-780-2, trade name, manufactured by Ishihara Sangyo Co., Ltd., 100% solid content)
・ Polyvinyl alcohol ・ ・ ・ ・ 8.0 parts (PVA-105, trade name, manufactured by Kuraray Co., Ltd., solid content 10%)
・ Surfactant ・ ・ ・ ・ 0.5 part (Demol EP, trade name, manufactured by Kao Corporation, solid content: 25%)
・ Distilled water: 51.6 parts
　次いで、得られた顔料分散物を用い、下記組成の諸成分を混合することにより反射層形成用塗布液を調製した。
　<反射層形成用塗布液の処方>
・上記の顔料分散物　　　　　　　　　　　・・・７１．４部
・ポリアクリル樹脂水分散液　　　　　　　・・・１７．１部
　（バインダー：ジュリマーＥＴ４１０、商品名、日本純薬工業（株）製、固形分：３０％）
・ポリオキシアルキレンアルキルエーテル　・・・・２．７部
　（ナロアクティーＣＬ９５、商品名、三洋化成工業（株）製、固形分：１％）
・オキサゾリン化合物（架橋剤）　　　　　・・・・１．８部
　（エポクロスＷＳ－７００、商品名、日本触媒（株）製、固形分：２５％）
・蒸留水　　　　　　　　　　　　　　　　・・・・７．０部 Next, using the obtained pigment dispersion, various components having the following composition were mixed to prepare a coating solution for forming a reflective layer.
<Prescription of reflection layer forming coating solution>
-The above pigment dispersion: 71.4 parts-Polyacrylic resin aqueous dispersion: 17.1 parts (Binder: Jurimer ET410, trade name, manufactured by Nippon Pure Chemical Industries, Ltd., solid content: 30% )
Polyoxyalkylene alkyl ether 2.7 parts (Naroacty CL95, trade name, manufactured by Sanyo Chemical Industries, solid content: 1%)
・ Oxazoline compound (crosslinking agent) ・ ・ ・ ・ 1.8 parts (Epocross WS-700, trade name, manufactured by Nippon Shokubai Co., Ltd., solid content: 25%)
・ Distilled water ・ ・ ・ ・ 7.0 parts
　上記より得られた反射層形成用塗布液をサンプルフィルムにバーコーターにより塗布し、１８０℃で１分間乾燥して、二酸化チタン塗布量が６．５ｇ／ｍ２の反射層（白色層）を形成した。 The reflective layer-forming coating solution obtained above is applied to a sample film with a bar coater and dried at 180 ° C. for 1 minute to form a reflective layer (white layer) with a titanium dioxide coating amount of 6.5 g / m 2. did.
（ii）易接着性層
　下記組成の諸成分を混合して易接着性層用塗布液を調製し、これをバインダー塗布量が０．０９ｇ／ｍ２になるように反射層の上に塗布した。その後、１８０℃で１分間乾燥させ、易接着性層を形成した。
　<易接着性層用塗布液の組成>
・ポリオレフィン樹脂水分散液　　　　　　・・・・５．２部
　（バインダー：ケミパールＳ７５Ｎ、商品名、三井化学（株）製、固形分：２４％）
・ポリオキシアルキレンアルキルエーテル　・・・・７．８部
　（ナロアクティーＣＬ９５、商品名、三洋化成工業（株）製、固形分：１％）
・オキサゾリン化合物　　　　　　　　　　・・・・０．８部
　（エポクロスＷＳ－７００、商品名、日本触媒（株）製、固形分２５％）
・シリカ微粒子水分散物　　　　　　　　　・・・・２．９部
　（アエロジルＯＸ－５０、商品名、日本アエロジル（株）製、固形分：１０％）
・蒸留水　　　　　　　　　　　　　　　　・・・８３．３部 (Ii) Easy-adhesive layer Various components having the following composition were mixed to prepare an easy-adhesive layer coating solution, which was applied onto the reflective layer so that the binder coating amount was 0.09 g / m 2 . . Then, it was made to dry at 180 degreeC for 1 minute, and the easily bonding layer was formed.
<Composition of coating solution for easy adhesion layer>
・ Polyolefin resin aqueous dispersion ・ ・ ・ ・ 5.2 parts (Binder: Chemipearl S75N, trade name, manufactured by Mitsui Chemicals, solid content: 24%)
Polyoxyalkylene alkyl ether: 7.8 parts (Naroacty CL95, trade name, manufactured by Sanyo Chemical Industries, solid content: 1%)
・ Oxazoline compound ・ ・ ・ ・ 0.8 parts (Epocross WS-700, trade name, manufactured by Nippon Shokubai Co., Ltd., solid content 25%)
-Silica fine particle aqueous dispersion-2.9 parts (Aerosil OX-50, trade name, manufactured by Nippon Aerosil Co., Ltd., solid content: 10%)
・ Distilled water ... 83.3 parts
　次に、ポリエステルフィルムの反射層及び易接着性層が形成されている側と反対側の面に、下記の（iii）下塗り層、（iv）バリア層、及び（ｖ）防汚層をポリエステルフィルム側から順次、塗設した。 Next, the polyester film is provided with the following (iii) undercoat layer, (iv) barrier layer, and (v) antifouling layer on the side opposite to the side where the reflective layer and the easy-adhesion layer of the polyester film are formed. Coated sequentially from the side.
（iii）下塗り層
　下記組成の諸成分を混合して下塗り層用塗布液を調製し、この塗布液をポリエステルフィルムに塗布し、１８０℃で１分間乾燥させ、下塗り層（乾燥塗設量：約０．１ｇ／ｍ２）を形成した。
　<下塗り層用塗布液の組成>
・ポリエステル樹脂　　　　　　　　　　　・・・・１．７部
　（バイロナールＭＤ－１２００、商品名、東洋紡（株）製、固形分：１７％）
・ポリエステル樹脂　　　　　　　　　　　・・・・３．８部
　（ペスレジンＡ-５２０、商品名、高松油脂（株）製、固形分：３０％）
・ポリオキシアルキレンアルキルエーテル　・・・・１．５部
　（ナロアクティーＣＬ９５、商品名、三洋化成工業（株）製、固形分：１％）
・カルボジイミド化合物　　　　　　　　　・・・・１．３部
　（カルボジライトＶ－０２－Ｌ２、商品名、日清紡（株）製、固形分：１０％）
・蒸留水　　　　　　　　　　　　　　　　・・・９１．７部 (Iii) Undercoat layer Various components having the following composition are mixed to prepare a coating solution for an undercoat layer, this coating solution is applied to a polyester film, dried at 180 ° C. for 1 minute, and an undercoat layer (dry coating amount: about 0.1 g / m 2 ) was formed.
<Composition of coating solution for undercoat layer>
・ Polyester resin ・ ・ ・ ・ 1.7 parts (Vylonal MD-1200, trade name, manufactured by Toyobo Co., Ltd., solid content: 17%)
・ Polyester resin ・ ・ ・ ・ 3.8 parts (Pesresin A-520, trade name, manufactured by Takamatsu Yushi Co., Ltd., solid content: 30%)
・ Polyoxyalkylene alkyl ether ... 1.5 parts (Naroacty CL95, trade name, manufactured by Sanyo Chemical Industries, Ltd., solid content: 1%)
Carbodiimide compound 1.3 parts (Carbodilite V-02-L2, trade name, manufactured by Nisshinbo Co., Ltd., solid content: 10%)
・ Distilled water ... 91.7 parts
（iv）バリア層
　続いて、形成された下塗り層の表面に下記の蒸着条件にて厚み８００Åの酸化珪素の蒸着膜を形成し、バリア層とした。
　<蒸着条件>
　・反応ガス混合比（単位：ｓｌｍ）：ヘキサメチルジシロキサン／酸素ガス／ヘリウム＝１／１０／１０
　・真空チャンバー内の真空度：５．０×１０－６ｍｂａｒ
　・蒸着チャンバー内の真空度：６．０×１０－２ｍｂａｒ
　・冷却・電極ドラム供給電力：２０ｋＷ
　・フィルムの搬送速度　　　：８０ｍ／分 (Iv) Barrier layer Subsequently, a vapor deposition film of silicon oxide having a thickness of 800 mm was formed on the surface of the formed undercoat layer under the following vapor deposition conditions to obtain a barrier layer.
<Deposition conditions>
Reaction gas mixture ratio (unit: slm): hexamethyldisiloxane / oxygen gas / helium = 1/10/10
・ Vacuum degree in the vacuum chamber: 5.0 × 10 −6 mbar
・ Vacuum degree in the deposition chamber: 6.0 × 10 −2 mbar
・ Cooling ・ Electrode drum power supply: 20kW
-Film transport speed: 80 m / min
（ｖ）防汚層
　以下に示すように、第１及び第２防汚層を形成するための塗布液を調製し、バリア層の上に第１防汚層用塗布液、第２防汚層用塗布液の順に塗布し、２層構造の防汚層を塗設した。 (V) Antifouling Layer As shown below, a coating solution for forming the first and second antifouling layers is prepared, and the first antifouling layer coating solution and the second antifouling layer are formed on the barrier layer. The coating solution was applied in the order, and a two-layer antifouling layer was applied.
　＜第１防汚層＞
－第１防汚層用塗布液の調製－
　下記組成中の成分を混合し、第１防汚層用塗布液を調製した。
　<塗布液の組成>
・セラネートＷＳＡ１０７０（商品名、ＤＩＣ（株）製）・・・４５．９部
・オキサゾリン化合物（架橋剤）　　　　　　　・・・・７．７部
　（エポクロスＷＳ－７００、商品名、日本触媒（株）製、固形分：２５％）
・ポリオキシアルキレンアルキルエーテル　　　・・・・２．０部
　（ナロアクティーＣＬ９５、商品名、三洋化成工業（株）製、固形分：１％）
・反射層で用いた顔料分散物　　　　　　　　　・・・３３．０部
・蒸留水　　　　　　　　　　　　　　　　　　・・・１１．４部 <First antifouling layer>
-Preparation of coating solution for first antifouling layer-
Components in the following composition were mixed to prepare a first antifouling layer coating solution.
<Composition of coating solution>
・ Ceranate WSA1070 (trade name, manufactured by DIC Corporation) ・ ・ ・ 45.9 parts ・ Oxazoline compound (crosslinking agent) ・ ・ ・ ・ 7.7 parts (Epocross WS-700, trade name, manufactured by Nippon Shokubai Co., Ltd.) , Solid content: 25%)
・ Polyoxyalkylene alkyl ether ... 2.0 parts (Naroacty CL95, trade name, manufactured by Sanyo Chemical Industries, solid content: 1%)
・ Pigment dispersion used in the reflective layer: 33.0 parts ・ Distilled water: 11.4 parts
－第１防汚層の形成－
　得られた塗布液を、バインダー塗布量が３．０ｇ／ｍ２になるように、バリア層の上に塗布し、１８０℃で１分間乾燥させて第１防汚層を形成した。 -Formation of the first antifouling layer-
The obtained coating solution was coated on the barrier layer so that the binder coating amount was 3.0 g / m 2 and dried at 180 ° C. for 1 minute to form a first antifouling layer.
－第２防汚層用塗布液の調製－
　下記組成中の成分を混合し、第２防汚層用塗布液を調製した。
　<塗布液の組成>
・フッ素系バインダー　　　　　　　　　　　　・・・４５．９部
（オブリガード、商品名、ＡＧＣコーテック（株）製）
・オキサゾリン化合物　　　　　　　　　　　　・・・・７．７部
（エポクロスＷＳ－７００、商品名、日本触媒（株）製、固形分：２５％；架橋剤）
・ポリオキシアルキレンアルキルエーテル　　　・・・・２．０部
（ナロアクティーＣＬ９５、商品名、三洋化成工業（株）製、固形分：１％）
・前記反射層用に調製した前記顔料分散物　　　・・・３３．０部
・蒸留水　　　　　　　　　　　　　　　　　　・・・１１．４部 -Preparation of coating solution for second antifouling layer-
Components in the following composition were mixed to prepare a second antifouling layer coating solution.
<Composition of coating solution>
・ Fluorine binder: 45.9 parts (Obligard, trade name, manufactured by AGC Co-Tech Co., Ltd.)
· Oxazoline compound ··· 7.7 parts (Epocross WS-700, trade name, manufactured by Nippon Shokubai Co., Ltd., solid content: 25%; crosslinking agent)
-Polyoxyalkylene alkyl ether-2.0 parts (Naroacty CL95, trade name, manufactured by Sanyo Chemical Industries, solid content: 1%)
-The pigment dispersion prepared for the reflective layer ... 33.0 parts-Distilled water ... 11.4 parts
－第２防汚層の形成－
　調製した第２防汚層用塗布液を、バインダー塗布量が２．０ｇ／ｍ２になるように、バリア層上に形成された第１防汚層の上に塗布し、１８０℃で１分間乾燥させて第２防汚層を形成した。 -Formation of second antifouling layer-
The prepared coating solution for the second antifouling layer was applied on the first antifouling layer formed on the barrier layer so that the binder coating amount was 2.0 g / m 2 , and the mixture was applied at 180 ° C. for 1 minute. A second antifouling layer was formed by drying.
　以上のようにして、ポリエステルフィルムの一方の側に反射層及び易接着層を有し、他方の側に下塗り層、バリア層、及び防汚層を有するバックシートを作製した。 As described above, a back sheet having a reflective layer and an easy adhesion layer on one side of the polyester film and having an undercoat layer, a barrier layer, and an antifouling layer on the other side was produced.
　実施例の太陽電池用バックシート１～９は、破断伸度半減時間のバラツキが小さい実施例のポリエステルフィルム１～９を用いて構成されるため、比較例の太陽電池用バックシート１０１～１０５に比べ、均一な耐加水分解性を示した。 Since the solar cell backsheets 1 to 9 of the examples are configured using the polyester films 1 to 9 of the examples with small variations in the half elongation time at break, the backsheets 101 to 105 for the solar cells of the comparative examples are used. In comparison, it showed uniform hydrolysis resistance.
〔実施例１１〕
５．太陽電池発電モジュールの作製
　上記のようにして作製したバックシート１～９及びバックシート１０１～１０５を用い、特開２００９－１５８９５２号公報の図１に示す構造になるように透明充填剤に貼り合わせ、太陽電池発電モジュール１～９及び１０１～１０５を作製した。このとき、バックシートの易接着性層が、太陽電池素子を包埋する透明充填剤に接するように貼り付けた。 Example 11
5). Production of Solar Cell Power Generation Module Using the backsheets 1 to 9 and the backsheets 101 to 105 produced as described above, they are bonded to a transparent filler so as to have the structure shown in FIG. 1 of JP-A-2009-158952. Solar cell power generation modules 1 to 9 and 101 to 105 were produced. At this time, it stuck so that the easily-adhesive layer of a backsheet might contact the transparent filler which embeds a solar cell element.
　実施例の太陽電池発電モジュール１～９は、破断伸度半減時間のバラツキが小さい実施例のポリエステルフィルム１～９を用いて構成されるため、比較例の太陽電池発電モジュール１０１～１０５に比べ、発電性能を長期に亘って安定的に得ることができた。 Since the solar cell power generation modules 1 to 9 of the examples are configured using the polyester films 1 to 9 of the examples with small variations in the half elongation time at break, compared with the solar cell power generation modules 101 to 105 of the comparative examples, The power generation performance can be obtained stably over a long period of time.
　２０１０年１２月１５日に出願された日本国特許出願第２０１０－２７９６０５号の開示は、その全体が参照により本明細書に取り込まれる。
　本明細書に記載された全ての文献、特許出願、および技術規格は、個々の文献、特許出願、および技術規格が参照により取り込まれることが具体的かつ個々に記された場合と同程度に、本明細書中に援用されて取り込まれる。 The disclosure of Japanese Patent Application No. 2010-279605 filed on December 15, 2010 is incorporated herein by reference in its entirety.
All documents, patent applications, and technical standards mentioned in this specification are to the same extent as if each individual document, patent application, and technical standard were specifically and individually described to be incorporated by reference, Incorporated herein by reference.

Claims (13)

  1. 　結晶化度分布Δρが３％＜Δρ≦１５％にあるポリエステルを、反応槽に供給して固相重合する固相重合工程と、
    　前記固相重合されたポリエステルを、フィルム状に押出成形する押出成形工程と、
    を有するポリエステルフィルムの製造方法。     The polyester crystallinity distribution [Delta] [rho] is in the 3% <Δρ ≦ 15%, solid phase polymerization step of solid phase polymerization is supplied to the reaction vessel,
    An extrusion process for extruding the solid-phase polymerized polyester into a film; and
    The manufacturing method of the polyester film which has this.
  2. 　前記ポリエステルの結晶化度分布Δρが５％≦Δρ≦１３％にある請求項１に記載のポリエステルフィルムの製造方法。 The method for producing a polyester film according to claim 1, wherein the crystallinity distribution Δρ of the polyester is 5% ≦ Δρ ≦ 13%.
  3. 　前記ポリエステルは、結晶子径分布ΔＤが１０％以下である請求項１または請求項２に記載のポリエステルフィルムの製造方法。 3. The method for producing a polyester film according to claim 1, wherein the polyester has a crystallite size distribution ΔD of 10% or less.
  4. 　前記ポリエステルは、結晶子径分布ΔＤが３％～９％である請求項１～請求項３のいずれか１項に記載のポリエステルフィルムの製造方法。 The method for producing a polyester film according to any one of claims 1 to 3, wherein the polyester has a crystallite size distribution ΔD of 3% to 9%.
  5. 　前記固相重合工程の前に、前記ポリエステルに温熱ガスを供給し、供給された前記温熱ガスによって前記ポリエステルを加熱して結晶化する請求項１～請求項４のいずれか１項に記載のポリエステルフィルムの製造方法。 The polyester according to any one of claims 1 to 4, wherein a hot gas is supplied to the polyester before the solid-phase polymerization step, and the polyester is heated and crystallized by the supplied hot gas. A method for producing a film.
  6. 　前記温熱ガスの供給量〔Ｎｍ３／Ｋｇ〕が、前記ポリエステル１ｋｇに対して、０．１Ｎｍ３～１．５Ｎｍ３である請求項５に記載のポリエステルフィルムの製造方法。 The supply amount of heat gas [Nm 3 / Kg] is, relative to the polyester 1 kg, method for producing a polyester film according to claim 5 which is 0.1Nm 3 ~ 1.5Nm 3.
  7. 　前記反応槽に入れるときの前記ポリエステルの温度が、１８０℃～２２０℃である請求項１～請求項６のいずれか１項に記載のポリエステルフィルムの製造方法。 The method for producing a polyester film according to any one of claims 1 to 6, wherein the temperature of the polyester when put into the reaction vessel is 180 ° C to 220 ° C.
  8. 　前記固相重合の時間が、５時間～１００時間である請求項１～請求項７のいずれか１項に記載のポリエステルフィルムの製造方法。 The method for producing a polyester film according to any one of claims 1 to 7, wherein a time for the solid phase polymerization is 5 hours to 100 hours.
  9. 　前記固相重合前のポリエステルの結晶子径Ｄが８０Å～１２０Åである請求項１～請求項８のいずれか１項に記載のポリエステルフィルムの製造方法。 The method for producing a polyester film according to any one of claims 1 to 8, wherein a crystallite diameter D of the polyester before the solid phase polymerization is 80 to 120 mm.
  10. 　前記固相重合前のポリエステルの結晶化度ρが４７％～５８％である請求項１～請求項９のいずれか１項に記載のポリエステルフィルムの製造方法。 The method for producing a polyester film according to any one of claims 1 to 9, wherein a crystallinity ρ of the polyester before the solid phase polymerization is 47% to 58%.
  11. 　請求項１～請求項１０のいずれか１項に記載のポリエステルフィルムの製造方法により製造された太陽電池用ポリエステルフィルム。 A solar cell polyester film produced by the method for producing a polyester film according to any one of claims 1 to 10.
  12. 　長尺状の形状を有すると共に、末端ＣＯＯＨを少なくとも含み、長手方向における前記末端ＣＯＯＨの量のバラツキが２ｅｑ／ｔｏｎ未満である請求項１１に記載の太陽電池用ポリエステルフィルム。 The polyester film for a solar cell according to claim 11, which has a long shape and includes at least terminal COOH, and variation in the amount of the terminal COOH in the longitudinal direction is less than 2 eq / ton.
  13. 　太陽光が入射する透明性の基板と、太陽電池素子と、該太陽電池素子の前記基板が配される側と反対側に設けられた請求項１１または請求項１２に記載の太陽電池用ポリエステルフィルムを備えた太陽電池発電モジュール。 The polyester film for solar cells of Claim 11 or Claim 12 provided in the opposite side to the side by which the board | substrate with which the board | substrate with which the board | substrate of the transparent substrate into which sunlight injects, and the said solar cell element is arranged. Solar cell power generation module with
PCT/JP2011/077401 2010-12-15 2011-11-28 Method for producing polyester film, polyester film for solar cell, and solar cell electric power generation module WO2012081385A1 (en)

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