WO2014189021A1 - Polylactide sheet and manufacturing method therefor - Google Patents

Polylactide sheet and manufacturing method therefor Download PDF

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Publication number
WO2014189021A1
WO2014189021A1 PCT/JP2014/063272 JP2014063272W WO2014189021A1 WO 2014189021 A1 WO2014189021 A1 WO 2014189021A1 JP 2014063272 W JP2014063272 W JP 2014063272W WO 2014189021 A1 WO2014189021 A1 WO 2014189021A1
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WIPO (PCT)
Prior art keywords
polylactic acid
sheet
poly
lactic acid
acid
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PCT/JP2014/063272
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French (fr)
Japanese (ja)
Inventor
山内英幸
新崎盛昭
坂本純
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東レ株式会社
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Priority to JP2014525649A priority Critical patent/JPWO2014189021A1/en
Publication of WO2014189021A1 publication Critical patent/WO2014189021A1/en

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    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J5/00—Manufacture of articles or shaped materials containing macromolecular substances
    • C08J5/18—Manufacture of films or sheets
    • 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
    • B29C48/36—Means for plasticising or homogenising the moulding material or forcing it through the nozzle or die
    • B29C48/50—Details of extruders
    • B29C48/69—Filters or screens for the moulding 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
    • 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
    • B29C48/50—Details of extruders
    • B29C48/76—Venting, drying means; Degassing means
    • 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
    • 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
    • B29C2948/92714—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
    • 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
    • B29C48/395—Means for plasticising or homogenising the moulding material or forcing it through the nozzle or die using screws surrounded by a cooperating barrel, e.g. single screw extruders
    • B29C48/40—Means for plasticising or homogenising the moulding material or forcing it through the nozzle or die using screws surrounded by a cooperating barrel, e.g. single screw extruders using two or more parallel screws or at least two parallel non-intermeshing screws, e.g. twin screw extruders
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
    • B29K2067/00—Use of polyesters or derivatives thereof, as moulding material
    • B29K2067/04—Polyesters derived from hydroxycarboxylic acids
    • B29K2067/046—PLA, i.e. polylactic acid or polylactide
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J2367/00—Characterised by the use of polyesters obtained by reactions forming a carboxylic ester link in the main chain; Derivatives of such polymers
    • C08J2367/04—Polyesters derived from hydroxy carboxylic acids, e.g. lactones
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L101/00—Compositions of unspecified macromolecular compounds
    • C08L101/16—Compositions of unspecified macromolecular compounds the macromolecular compounds being biodegradable

Definitions

  • the present invention relates to a polylactic acid-based sheet having excellent transparency, heat resistance, and high-temperature formability.
  • Polylactic acid is a polymer that can be practically melt-molded and has biodegradable characteristics. Therefore, after use, development as a biodegradable polymer that is decomposed in the natural environment and released as carbon dioxide or water has been promoted.
  • the properties of carbon neutral have attracted attention and are expected to be used as environmentally friendly materials.
  • the nature of carbon neutral is that polylactic acid itself is made from renewable resources (biomass) originating from carbon dioxide and water, so even if polylactic acid is used and carbon dioxide is released, Carbon dioxide does not increase or decrease.
  • lactic acid which is a monomer of polylactic acid, is being produced at a low cost by fermentation using microorganisms. Therefore, polylactic acid has been studied as an alternative material for general-purpose petroleum plastics.
  • polylactic acid has been tried for practical use in a wide range as a melt-molded product.
  • heat resistance and durability are low compared with petroleum plastics, and the range of practical use is greatly limited.
  • a crystallization treatment such as heat treatment is performed in order to improve the heat resistance of the polylactic acid molded article, there is a problem that it becomes white turbid and transparency is lowered. Therefore, a polylactic acid molded article having excellent heat resistance and transparency even in a crystallized state is desired.
  • the polylactic acid stereocomplex is formed by mixing optically active poly-L-lactic acid (hereinafter referred to as PLLA) and poly-D-lactic acid (hereinafter referred to as PDLA).
  • PLLA optically active poly-L-lactic acid
  • PDLA poly-D-lactic acid
  • Patent Document 1 a resin sheet containing stereocomplex polylactic acid that defines the breaking elongation and stress during heating is studied.
  • a sheet made of polylactic acid stereocomplex exhibits excellent heat resistance.
  • it since it has a rigid structure and has high rigidity, there has been a problem that in molding applications, it is necessary to mold in a high temperature region.
  • draw down a draw down phenomenon in which the sheet hangs down in a heating process before forming has been a problem.
  • Patent Document 1 Although the polylactic acid-based sheet described in Patent Document 1 is excellent in moldability, the drawdown is large in the heating process before molding because of high elongation at the time of heating. Therefore, there is a problem that the sheet breaks at the time of molding or the sheet becomes defective in molding.
  • an object of the present invention is to provide a polylactic acid-based sheet that is excellent in transparency and heat resistance, and further excellent in moldability at high temperatures.
  • the polylactic acid-based sheet of the present invention employs the following means in order to solve the above problems.
  • the polylactic acid includes a polylactic acid block copolymer composed of a segment composed of poly-L-lactic acid and a segment composed of poly-D-lactic acid, (1) to (3) The polylactic acid-based sheet according to any one of the above.
  • the polylactic acid-based sheet of the present invention is a sheet mainly composed of polylactic acid, and has a heat shrinkage rate at 160 ° C. of 0% to 30% and a crystallinity of 1% to 30%. To do.
  • a heat shrinkage rate at 160 ° C. of 0% to 30%
  • a crystallinity of 1% to 30% To do.
  • Polylactic acid means that the lactic acid component is 70 mol% or more and 100 mol% or less in 100 mol% of all monomer components constituting polylactic acid.
  • the polylactic acid in the present invention is not particularly limited, but is preferably polylactic acid selected from the group consisting of poly-L-lactic acid, poly-D-lactic acid, and a polylactic acid block copolymer described later.
  • poly-L-lactic acid means that when the lactic acid component in polylactic acid is 100 mol%, the L-lactic acid component is contained in an amount of 70 mol% to 100 mol%.
  • poly-D-lactic acid means that when the lactic acid component in the polylactic acid is 100 mol%, the D-lactic acid component is contained in an amount of 70 mol% to 100 mol%.
  • the poly-L-lactic acid preferably contains 90 to 100 mol% of the L-lactic acid component when the lactic acid component in the polylactic acid is 100 mol%. More preferably, the content is 95 mol% or more and 100 mol% or less. The content is particularly preferably 98 mol% or more and 100 mol% or less.
  • the poly-D-lactic acid preferably contains 90 to 100 mol% of the D-lactic acid component when the lactic acid component in the polylactic acid is 100 mol%. Moreover, it is more preferable to contain 95 mol% or more and 100 mol% or less. The content is particularly preferably 98 mol% or more and 100 mol% or less.
  • the polylactic acid may contain components other than the lactic acid component (L-lactic acid component or D-lactic acid component) as long as the performance of the present invention is not impaired.
  • other components include polycarboxylic acids, polyhydric alcohols, hydroxycarboxylic acids, and lactones.
  • polysuccinic acids such as succinic acid, adipic acid, sebacic acid, fumaric acid, terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, 5-sodium sulfoisophthalic acid, and 5-tetrabutylphosphonium sulfoisophthalic acid.
  • Carboxylic acids or their derivatives ethylene glycol, propylene glycol, butanediol, pentanediol, hexanediol, octanediol, neopentylglycol, glycerin, trimethylolpropane, pentaerythritol, trimethylolpropane or pentaerythritol with ethylene oxide or propylene oxide
  • Added polyhydric alcohol aromatic polyhydric alcohol obtained by addition reaction of bisphenol with ethylene oxide, diethylene glycol, triethylene glycol
  • Polyhydric alcohols such as liethylene glycol and polypropylene glycol or derivatives thereof, hydroxycarboxylic acids such as glycolic acid, 3-hydroxybutyric acid, 4-hydroxybutyric acid, 4-hydroxyvaleric acid, 6-hydroxycaproic acid, and glycolide, ⁇ -Caprolactone glycolide, ⁇ -caprolactone, ⁇ -propiolactone,
  • the polylactic acid-based sheet is mainly composed of polylactic acid means that when all the components in the polylactic acid-based sheet are 100% by mass, the polylactic acid is contained in an amount of 50% by mass to 100% by mass.
  • the polylactic acid-based sheet preferably contains 80% by mass or more and 100% by mass or less of polylactic acid when all components in the polylactic acid-based sheet are 100% by mass.
  • polylactic acid-based sheet of the present invention can contain various additives as long as the performance of the present invention is not impaired.
  • the polylactic acid-based sheet of the present invention can contain one or more crystal nucleating agents as long as the performance of the present invention is not impaired as required.
  • the crystal nucleating agent suitably contained in the polylactic acid-based sheet of the present invention include inorganic nucleating agents such as talc, ethylene bislauric acid amide, ethylene bis-12-dihydroxystearic acid amide, and trimesic acid tricyclohexyl amide.
  • Organic amide compounds such as copper phthalocyanine and pigment yellow 110, organic carboxylic acid metal salts, zinc phenylphosphonate and the like.
  • the polylactic acid-based sheet of the present invention can contain a moldability improving agent as long as it does not impair the performance of the present invention.
  • a moldability improver a multilayer structure polymer composed of a core layer and one or more shell layers covering it, a polyether block copolymer composed of a segment composed of polyether and a segment composed of polylactic acid And at least one selected from the group consisting of polyester-based block copolymers composed of polyester segments and polylactic acid segments, aliphatic polyesters (excluding polylactic acid), and aliphatic aromatic polyesters. Can be used.
  • the weight average molecular weight of polylactic acid is not particularly limited, but is preferably in the range of 100,000 to 300,000 in terms of moldability and mechanical properties. More preferably, the polylactic acid has a weight average molecular weight of 120,000 to 280,000. More preferably, it is 130,000 to 270,000. It is especially preferable that they are 140,000 or more and 260,000 or less.
  • the polylactic acid-based sheet of the present invention is mainly composed of polylactic acid.
  • polylactic acid for example, the following method A) or B) is preferable.
  • A) As polylactic acid a mixture of poly-L-lactic acid and poly-D-lactic acid is used.
  • B) As the polylactic acid a polylactic acid block copolymer (hereinafter referred to as a polylactic acid block copolymer) composed of a segment composed of poly-L-lactic acid and a segment composed of poly-D-lactic acid is used.
  • the method A) is that the polylactic acid contains poly-L-lactic acid and poly-D-lactic acid.
  • the polylactic acid contains a polylactic acid block copolymer composed of a segment composed of poly-L-lactic acid and a segment composed of poly-D-lactic acid.
  • the heat shrinkage rate of the polylactic acid-based sheet at 160 ° C. can be set to 0% to 30%, and the crystallinity can be further set to 1% to 30%. From the viewpoint that excellent transparency and heat resistance can be obtained when the sheet is formed, it is preferable to use a polylactic acid block copolymer as the method B), that is, polylactic acid.
  • melt kneading is not particularly limited. For example, there is a method of melt-kneading at a melting end temperature or higher of a component having a higher melting point among poly-L-lactic acid and poly-D-lactic acid. There is also a method of removing the solvent after mixing in the solvent.
  • At least one of molten poly-L-lactic acid and poly-D-lactic acid is allowed to stay in the melting machine in advance within the temperature range of melting point ⁇ 50 ° C. to melting point + 20 ° C. while being sheared, and then poly- There is a method of mixing so that crystals of a mixture of L-lactic acid and poly-D-lactic acid remain.
  • the method of melt-kneading at a temperature higher than the melting end temperature of the component having the higher melting point is poly-L-lactic acid and poly-D-lactic acid batchwise or continuously.
  • the method of mixing by a method is mentioned. You may mix by any method.
  • the kneading apparatus include a single screw extruder, a twin screw extruder, a plast mill, a kneader, and a stirred tank reactor equipped with a pressure reducing device. In view of uniform and sufficient kneading, it is preferable to use a twin screw extruder.
  • the mass ratio of poly-L-lactic acid to poly-D-lactic acid is 80:20 to 20:80. Is preferred. More preferably, it is 75:25 to 25:75. Further, it is preferably 70:30 to 30:70. In particular, it is most preferably 60:40 to 40:60.
  • the method for producing a polylactic acid block copolymer is particularly limited when a polylactic acid block copolymer composed of a segment composed of poly-L-lactic acid and a segment composed of poly-D-lactic acid is used as the polylactic acid.
  • a general method for producing polylactic acid can be used.
  • the polylactic acid block copolymer is prepared by mixing poly-L-lactic acid and poly-D-lactic acid in a twin screw extruder, and subsequently solid-phase polymerizing the mixture. This is preferable in that the resulting sheet has excellent heat resistance and transparency.
  • either of the cyclic dimer L-lactide or D-lactide generated from the raw lactic acid component is subjected to ring-opening polymerization in the presence of a catalyst, and lactide which is an optical isomer of the polylactic acid is added.
  • lactide method for producing a polylactic acid block copolymer by ring-opening polymerization is a lactide method for producing a polylactic acid block copolymer by ring-opening polymerization.
  • poly-L-lactic acid and poly-D-lactic acid are melt-kneaded for a long time at a temperature equal to or higher than the melting end temperature of the component having a higher melting point, whereby the L-lactic acid component segment and the D-lactic acid component segment are esterified.
  • poly-L-lactic acid and poly-D-lactic acid are covalently bonded with polyfunctional compound by mixing polyfunctional compound with poly-L-lactic acid and poly-D-lactic acid and reacting them.
  • polyfunctional compound by mixing polyfunctional compound with poly-L-lactic acid and poly-D-lactic acid and reacting them.
  • block copolymer There is a method for producing a block copolymer.
  • a segment composed of poly-L-lactic acid and a segment composed of poly-D-lactic acid is used as polylactic acid
  • the mass ratio of the segments made of lactic acid is preferably 80:20 to 20:80. More preferably, it is 75:25 to 25:75. Further, it is preferably 70:30 to 30:70. In particular, it is most preferably 60:40 to 40:60.
  • the heat shrinkage rate of the polylactic acid sheet of the present invention at 160 ° C. is 0% to 30%.
  • the heat shrinkage rate at 160 ° C. of the polylactic acid-based sheet is more preferably 5% to 30%, which has a great effect on suppressing drawdown. More preferably, it is 5% to 20%. If the heat shrinkage rate at 160 ° C. is less than 0%, the drawdown may increase because the sheet stretches. On the other hand, if the heat shrinkage rate at 160 ° C. exceeds 30%, the moldability may deteriorate in the subsequent molding step.
  • the heat shrinkage rate of the polylactic acid-based sheet of the present invention at 160 ° C. is 0.
  • a polylactic acid-based sheet is produced by a production method having a step of forming a sheet-like material mainly composed of polylactic acid, a step of heat treatment at 90 ° C. to 200 ° C., and a step of stretching. The method of doing can be mentioned.
  • the step of heat treatment and the step of stretching can be preferably employed either by a continuous method or by a step of winding and then stretching the sheet after the step of heat treatment.
  • the crystallinity of the polylactic acid sheet of the present invention is 1% to 30%.
  • the degree of crystallinity of the polylactic acid-based sheet is more preferably 5% to 25%. If the crystallinity is less than 1%, drawdown may increase, and if it exceeds 30%, moldability may be poor.
  • the polylactic acid-based sheet of the present invention is preferably produced by a production method having a step of forming a sheet-like material mainly composed of polylactic acid, a step of heat treatment at 90 ° C. to 200 ° C., and a step of stretching.
  • the step of forming a sheet-like material mainly composed of polylactic acid is not particularly limited.
  • the polymer is filtered.
  • a method is preferably employed in which the material is filtered, extruded from a mouthpiece having a tip-shaped shape, and wound onto the cast drum after closely contacting the cast drum.
  • the method of heating in the heat treatment step is not particularly limited, but heating in a heating oven or a tenter heating oven or heating with a heating roll is preferable.
  • non-adhesive such as a silicon rubber coated roll, a silicone-treated roll, a fluorine-treated roll, and a roll whose surface is roughened by sandblasting
  • the roll is preferably used as a heating roll.
  • a method of heating with a heating oven or a tenter type heating oven a method using hot air, a method using a far infrared heater, a method using a combination of these, or the like can be preferably employed.
  • a guide roll or the like when a guide roll or the like is installed in the oven, it is preferable to employ a non-adhesive roll as the guide roll. From the concern of sticking to the guide roll in the oven, it is particularly preferable to use a floating dryer in which no guide roll is installed in the oven.
  • the heat treatment temperature in the heat treatment step is preferably 90 ° C. to 200 ° C., more preferably 100 ° C. to 180 ° C. in order to suppress drawdown. If the heat treatment temperature is lower than 90 ° C., a sufficient crystallinity cannot be obtained, that is, the crystallinity cannot be made 1% to 30%, so that drawdown may be increased. Further, if the heat treatment temperature exceeds 200 ° C., the sheet is softened, so that sufficient crystallinity cannot be obtained, that is, the crystallinity cannot be made 1% to 30%, and the drawdown becomes large. There is.
  • the heat treatment time in the heat treatment step is preferably 5 seconds to 5 minutes, and more preferably 5 seconds to 3 minutes in order to control the crystallinity of the polylactic acid sheet to 1% to 30%. If the heat treatment time is less than 5 seconds, sufficient crystallinity may not be obtained, and if it exceeds 5 minutes, productivity may be inferior.
  • the stretching method in the stretching step after the heat treatment is not particularly limited, but stretching with a heating roll or a tenter type stretching machine is preferable. Among these, it is preferable to carry out with a tenter type stretching machine.
  • a heating roll it is performed in the length direction due to the peripheral speed difference of the heating roll.
  • stretching machine the width
  • the stretching temperature in the stretching step is preferably 70 ° C. to 200 ° C., more preferably 70 ° C. to 180 ° C., and further preferably 70 ° C. to 160 ° C. in order to suppress drawdown. If the stretching temperature is lower than 70 ° C., the stretching stress may be increased, and the sheet exceeding 200 ° C. may be softened to increase the drawdown.
  • the stretching ratio in the stretching step is preferably 1.1 to 3.0 times in order to suppress drawdown. More preferably, it is 1.1 times to 2.0 times. More preferably, it is 1.1 times to 1.5 times. If the draw ratio is less than 1.1 times, the drawdown may increase. If it exceeds 3.0 times, the shrinkage amount becomes too large, and the subsequent formability may deteriorate.
  • the preheating step in the stretching step is understood as a heat treatment step if it is heated to 90 ° C to 200 ° C. Further, if the draw ratio is slight and the film is heated to 90 ° C. to 200 ° C., it is understood as a heat treatment step.
  • the plane orientation coefficient fn of the polylactic acid based sheet is preferably 0.1 ⁇ 10 ⁇ 2 to 5 ⁇ 10 ⁇ 2 . More preferably, it is 0.5 ⁇ 10 ⁇ 2 to 3 ⁇ 10 ⁇ 2 . When the plane orientation coefficient is less than 0.1 ⁇ 10 ⁇ 2 , drawdown may increase. If it exceeds 5 ⁇ 10 ⁇ 2 , moldability may be poor.
  • the stereoification rate of the polylactic acid sheet is preferably 80% to 100%. More preferably, it is 90% to 100%. If the stereo ratio is less than 80%, the drawdown may increase.
  • the method of setting the stereo ratio to 80% to 100% can be achieved by providing a drawing step after the step of heat-treating a sheet mainly composed of polylactic acid at 90 ° C. to 200 ° C.
  • Thermal shrinkage at 160 ° C. (%) A strip-like sample having a width of 4 mm is cut out from the sheet in the longitudinal direction of the sheet, and using a thermomechanical analyzer (TMA6100 manufactured by SII), a load is set to 29.6 mN / mm 2 , a temperature rising rate is 10 K / min, and a sample length is set to 20 mm. Was measured to determine the amount of shrinkage at 160 ° C. And the thermal contraction rate in 160 degreeC was calculated
  • Thermal shrinkage rate (%) Shrinkage amount at 160 ° C./Sample length at 25 ° C. ⁇ 100 Expression (1) (2) Crystallinity (%) With respect to a diffraction peak obtained by a wide-angle X-ray diffraction method (2 ⁇ - ⁇ scan method) with an X-ray diffractometer (D8 ADVANCE manufactured by Bruker AXS), 2 ⁇ is 10 based on the diffraction curve associated with the amorphous portion. The total area (Stotal) of ⁇ 30 degrees was determined, the area of the diffraction curve associated with the amorphous part was determined, and the crystallinity was determined from the following formula.
  • Crystallinity (%) Total / (Stotal + area of diffraction curve associated with amorphous part) ⁇ 100
  • X-ray source CuK ⁇ ray output: 40 kV, 40 mA
  • RS 0.6 mm
  • RSm 1 mm
  • Plane orientation coefficient (fn) Refractive indexes (Nx, Ny, and Nz) in the sheet longitudinal direction, width direction, and thickness direction were measured with an Abbe refractometer, and calculated by the following equations.
  • the melting point of polylactic acid was measured with a differential scanning calorimeter (DSC) manufactured by PerkinElmer. The measurement conditions are 5 mg of the sample, a nitrogen atmosphere, and a heating rate of 20 ° C./min.
  • the melting point refers to the temperature of the peak top in the crystal melting peak.
  • the melting point shown here is the first measurement (1stRUN), the temperature is increased from 30 ° C. to 250 ° C. at a temperature increase rate of 20 ° C./min, and then cooled to 30 ° C. at a temperature decrease rate of 999 ° C./min.
  • the melting point was measured when the temperature was increased from 30 ° C. to 250 ° C. at a temperature increase rate of 20 ° C./min.
  • the sheet stereoization rate is determined by the melting enthalpy ( ⁇ Hsc) of the endothermic curve having a peak at 190 ° C. or higher and lower than 230 ° C. measured by the method for measuring the melting point of the sheet under the same conditions as the above-described melting point measurement method. It refers to the value obtained from the equation (2) using the melting enthalpy ( ⁇ Homo) of an endothermic curve having a peak at a temperature of from °C to 185 ° C.
  • Sheet moldability S (very good): The sheet is molded so as to sufficiently follow the bottom surface of the tray-shaped molded body.
  • B Molding failure: The sheet is not sufficiently track-formed to the bottom surface of the tray, or even if the sheet is track-formed, breakage of the sheet at the bottom surface is confirmed.
  • the weight average molecular weight of polylactic acid is a standard polymethyl methacrylate conversion value measured by gel permeation chromatography (GPC).
  • GPC gel permeation chromatography
  • a differential refractometer WATERS410 manufactured by WATERS is used as a detector
  • a MODEL510 manufactured by WATERS is used as a pump
  • Shodex (registered trademark) GPC HFIP-806M and Shodex (registered trademark) manufactured by Showa Denko KK are used as a column.
  • GPC HFIP-LG was used in series.
  • the measurement conditions were a flow rate of 0.5 mL / min, and in the measurement, hexafluoroisopropanol was used as a solvent, and 0.1 mL of a solution having a sample concentration of 1 mg / mL was injected.
  • A1 Production Example 1 (mixture of poly-L-lactic acid and poly-D-lactic acid)
  • A2 Production Example 2 (polylactic acid block copolymer composed of a segment composed of poly-L-lactic acid and a segment composed of poly-D-lactic acid)
  • [Production Example 1] (Production Example of A1)
  • a reaction vessel equipped with a stirrer and a reflux device 50 parts by mass of a 90% by mass L-lactic acid aqueous solution was added, the temperature was raised to 150 ° C., and the reaction was continued for 3.5 hours while gradually reducing the pressure to distill off water.
  • PLLA1 had a weight average molecular weight of 18,000 and a melting point of 149 ° C.
  • PLLA1 was subjected to crystallization treatment at 110 ° C. for 1 hour in a nitrogen atmosphere, followed by solid phase polymerization under a pressure of 60 Pa for 3 hours at 140 ° C., 3 hours at 150 ° C., and 18 hours at 160 ° C.
  • Poly-L-lactic acid (PLLA2) was obtained.
  • PLLA2 had a weight average molecular weight of 203,000 and a melting point of 170 ° C.
  • a 90% by mass D-lactic acid aqueous solution is placed in a reaction vessel equipped with a stirrer and a reflux apparatus, and the temperature is set to 150 ° C. Then, the pressure is gradually reduced and water is distilled off. Reacted for 5 hours. Thereafter, the pressure is brought to normal pressure in a nitrogen atmosphere, 0.02 part by mass of tin (II) acetate is added, and then a polymerization reaction is carried out for 7 hours while gradually reducing the pressure to 170 Pa at 13 ° C. to obtain poly-D-lactic acid. (PDLA1) was obtained. PDLA1 had a weight average molecular weight of 17,000 and a melting point of 148 ° C.
  • the obtained PDLA1 was subjected to a heat treatment for crystallization in a nitrogen atmosphere at 110 ° C. for 1 hour, followed by solid state polymerization under a pressure of 60 Pa for 3 hours at 140 ° C., 3 hours at 150 ° C., and 14 hours at 160 ° C.
  • PDLA2 poly-L-lactic acid
  • PDLA2 had a weight average molecular weight of 1580,000 and a melting point of 168 ° C.
  • PLLA2 and PDLA2 are preliminarily subjected to heat treatment for crystallization at a temperature of 110 ° C. for 2 hours in a nitrogen atmosphere, and PLLA2 / PDLA2 is blended to a mass ratio of 70/30 to deactivate the catalyst.
  • 0.5 parts by mass of an agent manufactured by Adeka, “Adeka Stub” AX-71
  • Adeka “Adeka Stub” AX-71
  • the cylinder temperature was set to 240 ° C. and the screw rotation speed was set to 100 rpm.
  • the strand discharged from the die is cooled in a cooling bath, and then pelletized with a strand cutter, so that the pellet-shaped polylactic acid A1 is obtained. Obtained.
  • the weight average molecular weight and melting point of polylactic acid A1 were as shown in Table 1. The obtained A1 was subjected to crystallization treatment at a pressure of 13.3 Pa, 110 ° C. for 2 hours, and 140 ° C. for 6 hours.
  • A2 was a step of producing a mixture by mixing poly-L-lactic acid and poly-D-lactic acid in a twin screw extruder, and the polylactic acid block copolymer was produced by solid-phase polymerization of the mixture.
  • PDLA1 obtained in Production Example 1 was subjected to a heat treatment for crystallization in a nitrogen atmosphere at 110 ° C. for 1 hour, and then at a pressure of 60 Pa, 140 ° C. for 3 hours, 150 ° C. for 3 hours, Solid phase polymerization was performed at 160 ° C. for 6 hours to obtain poly-D-lactic acid (PDLA3).
  • PDLA3 had a weight average molecular weight of 42,000 and a melting point of 158 ° C.
  • the twin screw extruder is provided with a plasticizing part set at a temperature of 180 ° C.
  • the structure can be mixed under shearing, and PLLA2 and PDLA3 were mixed at a mixing temperature of 200 ° C. under shearing.
  • the strand discharged from the die was cooled in a cooling bath, and then pelletized by a strand cutter to obtain pellet-shaped melt-kneaded polylactic acid.
  • the obtained melt-kneaded polylactic acid was dried in a vacuum dryer at 110 ° C. and a pressure of 13.3 Pa for 2 hours, then subjected to solid state polymerization at 140 ° C. and a pressure of 13.3 Pa for 4 hours, and then heated to 150 ° C. Then, the temperature was further raised to 160 ° C. for 4 hours and solid phase polymerization was performed for 10 hours to obtain a polylactic acid block copolymer. Next, 0.5 parts by mass of 100 parts by mass of the polylactic acid block copolymer obtained from the catalyst deactivator (manufactured by ADEKA, “ADEKA STAB” AX-71) was dry-blended, and the cylinder temperature was 240 ° C.
  • pellet-shaped polylactic acid A2 was obtained.
  • the weight average molecular weight and melting point of polylactic acid A2 were as shown in Table 1.
  • the crystallization treatment was performed at a pressure of 13.3 Pa, 110 ° C. for 2 hours, and 140 ° C. for 6 hours.
  • Examples 1-21 and Comparative Examples 1-3 Process for forming a sheet-like material mainly composed of polylactic acid After melt melting and kneading polylactic acid at 230 ° C. while degassing the vacuum vent part, the polymer is filtered with a 200 mesh wire mesh filter. The sheet was wound up after extruding from a mouthpiece with a tip set at a temperature of 0 ° C. and brought into close contact with a cast drum having a diameter of 30 cm heated to 40 ° C. using an air chamber. At this time, the thickness of the sheet was 250 ⁇ m.
  • Step of heat treatment The sheet thus obtained was heated by a heating roll comprising four silicon rubber coated rolls having a diameter of 20 cm under the conditions shown in Table 2 for heat treatment.
  • the heat-treated sheet is subjected to the conditions shown in Table 2 with a preheating portion comprising a ceramic coating roll having a diameter of 20 cm, a stretching roll comprising a nip roll comprising a ceramic coating roll having a diameter of 12 cm and a silicon coating roll having a diameter of 12 cm, and a diameter of 12 cm. It extended
  • the characteristics of the obtained sheet are as shown in Table 5.
  • the amount of drawdown was small and the moldability was good.
  • the drawdown amount was large and the moldability was poor.
  • Example 22-29 The sheet before heat treatment obtained by the same procedure as in Example 1 was subjected to heat treatment in a floating dryer consisting of a first (heating) zone having a length of 5 m and a second (cooling) zone having a length of 3 m under the conditions shown in Table 3. It was. The heat treatment was performed in the first zone, the heat treatment temperature was the temperature of the first zone, and the heat treatment time was the time from when the sheet was supplied to the first zone until it was discharged.
  • the heat-treated sheet was subjected to a preheating portion composed of a ceramic coating roll having a diameter of 20 cm, a stretching roll composed of a nip roll composed of a ceramic coating roll having a diameter of 12 cm and a silicon coating roll having a diameter of 12 cm, and Hcr plating having a diameter of 12 cm. Then, the film was drawn into a drawing machine composed of a cooling part made of a roll. The properties of the obtained sheet are as shown in Table 6. The drawdown amount was small and the moldability was good.
  • Examples 30-35 The heat-treated sheets obtained in Examples 3 and 5 were subjected to the conditions shown in Table 4 with a first (preheating) zone having a length of 1.5 m, a second (stretching) zone having 3 m, and a third (cooling) zone having 1.5 m. Stretching was performed in a tenter oven. The properties of the obtained sheet are as shown in Table 6. The drawdown amount was small and the moldability was good.

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Abstract

The purpose of the present invention is to obtain a polylactide sheet of excellent transparency and heat resistance and with excellent high temperature moldability. This polylactide sheet has polylactide as the main component and is characterized in that heat shrinkage at 160°C is 0% - 30% and the degree of crystallinity is 1% - 30%.

Description

ポリ乳酸系シート及びその製造方法Polylactic acid-based sheet and method for producing the same
　本発明は、透明性、耐熱性優れ、高温成形性に優れたポリ乳酸系シートに関する。 The present invention relates to a polylactic acid-based sheet having excellent transparency, heat resistance, and high-temperature formability.
　ポリ乳酸は実用上溶融成形可能な高分子であり、生分解性の特徴を有する。よって、使用した後は自然環境中で分解して炭酸ガスや水として放出される生分解性高分子としての開発が進められてきた。一方、近年では、カーボンニュートラルの性質が注目され、環境低負荷材料としての利用が期待されている。カーボンニュートラルの性質とは、ポリ乳酸自身が二酸化炭素や水を起源とする再生可能資源（バイオマス）を原料としているため、ポリ乳酸が使用されて二酸化炭素が放出されたとしても、地球環境中における二酸化炭素は増減しないという性質である。さらに、ポリ乳酸のモノマーである乳酸は微生物を利用した発酵法により安価に製造されつつある。それ故、ポリ乳酸は汎用石油系プラスチックの代替素材としても検討されるようになってきた。 Polylactic acid is a polymer that can be practically melt-molded and has biodegradable characteristics. Therefore, after use, development as a biodegradable polymer that is decomposed in the natural environment and released as carbon dioxide or water has been promoted. On the other hand, in recent years, the properties of carbon neutral have attracted attention and are expected to be used as environmentally friendly materials. The nature of carbon neutral is that polylactic acid itself is made from renewable resources (biomass) originating from carbon dioxide and water, so even if polylactic acid is used and carbon dioxide is released, Carbon dioxide does not increase or decrease. Furthermore, lactic acid, which is a monomer of polylactic acid, is being produced at a low cost by fermentation using microorganisms. Therefore, polylactic acid has been studied as an alternative material for general-purpose petroleum plastics.
　このような性質から、ポリ乳酸は溶融成形体として幅広い実用化が試みられている。しかし、石油系プラスチックに比較すると耐熱性や耐久性が低く、実用化の範囲は大幅に限定されているのが現状である。また、ポリ乳酸成形体の耐熱性を向上させるため、熱処理等の結晶化処理を行うと、白濁化して透明性が低下する問題がある。そのため、耐熱性に優れ、結晶化状態においても透明性を有するポリ乳酸成形体が望まれている。 Because of these properties, polylactic acid has been tried for practical use in a wide range as a melt-molded product. However, heat resistance and durability are low compared with petroleum plastics, and the range of practical use is greatly limited. Further, when a crystallization treatment such as heat treatment is performed in order to improve the heat resistance of the polylactic acid molded article, there is a problem that it becomes white turbid and transparency is lowered. Therefore, a polylactic acid molded article having excellent heat resistance and transparency even in a crystallized state is desired.
　このような問題点を解決する手段の一つとして、ポリ乳酸ステレオコンプレックスの利用が注目されている。ポリ乳酸ステレオコンプレックスは、光学活性なポリ－Ｌ－乳酸（以下、ＰＬＬＡと称する）とポリ－Ｄ－乳酸（以下、ＰＤＬＡと称する）を混合することにより形成される。この融点はポリ乳酸ホモポリマーの融点１７０℃に比較して５０℃高い２２０℃に達する。そこで、この性質を利用して高融点および高結晶性の繊維や樹脂成型品、透明性を有するシートとしての適用が試みられている。 As one of the means for solving such problems, the use of polylactic acid stereocomplex is attracting attention. The polylactic acid stereocomplex is formed by mixing optically active poly-L-lactic acid (hereinafter referred to as PLLA) and poly-D-lactic acid (hereinafter referred to as PDLA). This melting point reaches 220 ° C., 50 ° C. higher than the melting point 170 ° C. of the polylactic acid homopolymer. Therefore, application as a sheet having a high melting point and a high crystalline fiber, a resin molded product, or transparency using this property has been attempted.
　特許文献１では、加熱時の破断伸度、応力を規定したステレオコンプレックスポリ乳酸を含む樹脂シートが検討されている。 In Patent Document 1, a resin sheet containing stereocomplex polylactic acid that defines the breaking elongation and stress during heating is studied.
特開２０１１－２３１２４０号公報JP 2011-231240 A
　ポリ乳酸ステレオコンプレックスからなるシートは、優れた耐熱性を発現する。しかし、剛直な構造を有し、剛性が高くなるため、成形用途においては、高温領域で成形する必要があるという問題があった。また、高温領域で成形を行うために成形前の加熱工程でシートが垂れ下がるドローダウン現象（以下ドローダウンと称する）が問題であった。 A sheet made of polylactic acid stereocomplex exhibits excellent heat resistance. However, since it has a rigid structure and has high rigidity, there has been a problem that in molding applications, it is necessary to mold in a high temperature region. In addition, since the sheet is formed in a high temperature region, a draw down phenomenon (hereinafter referred to as “draw down”) in which the sheet hangs down in a heating process before forming has been a problem.
　特許文献１に記載のポリ乳酸系シートは、成形性は優れているものの、加熱時の伸度が大きいために、成形前の加熱工程でドローダウンが大きい。それ故、成形時にシートが破断したり、シートが成形不良となる問題がある。 Although the polylactic acid-based sheet described in Patent Document 1 is excellent in moldability, the drawdown is large in the heating process before molding because of high elongation at the time of heating. Therefore, there is a problem that the sheet breaks at the time of molding or the sheet becomes defective in molding.
　そこで本発明は、透明性、耐熱性に優れ、さらに高温での成形性に優れたポリ乳酸系シートを提供することを目的とする。 Accordingly, an object of the present invention is to provide a polylactic acid-based sheet that is excellent in transparency and heat resistance, and further excellent in moldability at high temperatures.
　本発明のポリ乳酸系シートは、上記課題を解決するために、次のような手段を採用するものである。
（１）ポリ乳酸を主体とするシートであって、１６０℃における熱収縮率が０％～３０％であり、結晶化度が１％～３０％であることを特徴とする、ポリ乳酸系シート。
（２）面配向係数ｆｎが０．１×１０－２～５×１０－２であることを特徴とする、（１）に記載のポリ乳酸系シート。
（３）ステレオ化率が８０％～１００％であることを特徴とする、（１）または（２）に記載のポリ乳酸系シート。
（４）前記ポリ乳酸が、ポリ－Ｌ－乳酸からなるセグメント及びポリ－Ｄ－乳酸からなるセグメントから構成されるポリ乳酸ブロック共重合体を含むことを特徴とする、（１）～（３）のいずれかに記載のポリ乳酸系シート。
（５）１６０℃における熱収縮率が５％～３０％であることを特徴とする、（１）～（４）のいずれかに記載のポリ乳酸系シート。
（６）（１）～（５）のいずれかに記載のポリ乳酸系シートの製造方法であって、
　ポリ乳酸を主体とするシート状物を形成する工程、９０℃～２００℃で熱処理する工程、延伸する工程をこの順に有することを特徴とする、ポリ乳酸系シートの製造方法。
（７）前記熱処理する工程における加熱を、加熱ロールで行うことを特徴とする（６）に記載のポリ乳酸系シートの製造方法。
（８）前記加熱ロールが、非粘着性ロールであることを特徴とする（７）に記載のポリ乳酸系シートの製造方法。
（９）前記熱処理する工程における加熱を、フローティング乾燥機で行うことを特徴とする（６）に記載のポリ乳酸系シートの製造方法。
（１０）前記延伸する工程における延伸を、テンター式延伸機で行うことを特徴とする（６）に記載のポリ乳酸系シートの製造方法。 The polylactic acid-based sheet of the present invention employs the following means in order to solve the above problems.
(1) A sheet mainly composed of polylactic acid, having a heat shrinkage rate at 160 ° C. of 0% to 30% and a crystallinity of 1% to 30%, .
(2) The polylactic acid-based sheet according to (1), wherein the plane orientation coefficient fn is 0.1 × 10 −2 to 5 × 10 −2 .
(3) The polylactic acid-based sheet according to (1) or (2), characterized in that a stereogenic rate is 80% to 100%.
(4) The polylactic acid includes a polylactic acid block copolymer composed of a segment composed of poly-L-lactic acid and a segment composed of poly-D-lactic acid, (1) to (3) The polylactic acid-based sheet according to any one of the above.
(5) The polylactic acid sheet according to any one of (1) to (4), wherein a heat shrinkage rate at 160 ° C. is 5% to 30%.
(6) A method for producing a polylactic acid sheet according to any one of (1) to (5),
A method for producing a polylactic acid-based sheet, comprising a step of forming a sheet-like material mainly composed of polylactic acid, a step of heat treatment at 90 to 200 ° C, and a step of stretching.
(7) The method for producing a polylactic acid-based sheet according to (6), wherein the heating in the heat treatment step is performed with a heating roll.
(8) The method for producing a polylactic acid sheet according to (7), wherein the heating roll is a non-adhesive roll.
(9) The method for producing a polylactic acid-based sheet according to (6), wherein the heating in the heat treatment step is performed with a floating dryer.
(10) The method for producing a polylactic acid-based sheet according to (6), wherein the stretching in the stretching step is performed with a tenter type stretching machine.
　本発明によれば、透明性、耐熱性に優れ、高温での成形性に優れたポリ乳酸系シートを提供することが可能である。 According to the present invention, it is possible to provide a polylactic acid-based sheet having excellent transparency and heat resistance and excellent moldability at high temperatures.
　本発明のポリ乳酸系シートは、ポリ乳酸を主体とするシートであって、１６０℃における熱収縮率が０％～３０％であり、結晶化度が１％～３０％であることを特徴とする。以下、本発明の各要件などについて説明する。 The polylactic acid-based sheet of the present invention is a sheet mainly composed of polylactic acid, and has a heat shrinkage rate at 160 ° C. of 0% to 30% and a crystallinity of 1% to 30%. To do. Hereinafter, each requirement of the present invention will be described.
　ポリ乳酸とは、ポリ乳酸を構成する全ての単量体成分１００モル％において、乳酸成分が７０モル％以上１００モル％以下のものを意味する。 Polylactic acid means that the lactic acid component is 70 mol% or more and 100 mol% or less in 100 mol% of all monomer components constituting polylactic acid.
　本発明におけるポリ乳酸は、特に限定されないが、ポリ－Ｌ－乳酸、ポリ－Ｄ－乳酸、及び後述するポリ乳酸ブロック共重合体からなる群より選ばれるポリ乳酸であることが好ましい。ここでポリ－Ｌ－乳酸とは、ポリ乳酸中の乳酸成分を１００モル％とした際に、Ｌ－乳酸成分を７０モル％以上１００モル％以下含有していることを意味する。また、ポリ－Ｄ－乳酸とは、ポリ乳酸中の乳酸成分を１００モル％とした際に、Ｄ－乳酸成分を７０モル％以上１００モル％以下含有していることを意味する。 The polylactic acid in the present invention is not particularly limited, but is preferably polylactic acid selected from the group consisting of poly-L-lactic acid, poly-D-lactic acid, and a polylactic acid block copolymer described later. Here, poly-L-lactic acid means that when the lactic acid component in polylactic acid is 100 mol%, the L-lactic acid component is contained in an amount of 70 mol% to 100 mol%. The term “poly-D-lactic acid” means that when the lactic acid component in the polylactic acid is 100 mol%, the D-lactic acid component is contained in an amount of 70 mol% to 100 mol%.
　ポリ－Ｌ－乳酸としては、ポリ乳酸中の乳酸成分を１００モル％とした際に、Ｌ－乳酸成分を９０モル％以上１００モル％以下含有していることがより好ましい。９５モル％以上１００モル％以下含有していることがさらに好ましい。９８モル％以上１００モル％以下含有していることが特に好ましい。ポリ－Ｄ－乳酸としては、ポリ乳酸中の乳酸成分を１００モル％とした際に、Ｄ－乳酸成分を９０モル％以上１００モル％以下含有していることがより好ましい。また、９５モル％以上１００モル％以下含有していることがさらに好ましい。９８モル％以上１００モル％以下含有していることが特に好ましい。 The poly-L-lactic acid preferably contains 90 to 100 mol% of the L-lactic acid component when the lactic acid component in the polylactic acid is 100 mol%. More preferably, the content is 95 mol% or more and 100 mol% or less. The content is particularly preferably 98 mol% or more and 100 mol% or less. The poly-D-lactic acid preferably contains 90 to 100 mol% of the D-lactic acid component when the lactic acid component in the polylactic acid is 100 mol%. Moreover, it is more preferable to contain 95 mol% or more and 100 mol% or less. The content is particularly preferably 98 mol% or more and 100 mol% or less.
　ポリ乳酸は、本発明の性能を損なわない範囲で、乳酸成分（Ｌ－乳酸成分またはＤ－乳酸成分）以外の他の成分を含んでいてもよい。他の成分としては、多価カルボン酸、多価アルコール、ヒドロキシカルボン酸、ラクトンなどが挙げられる。具体的には、コハク酸、アジピン酸、セバシン酸、フマル酸、テレフタル酸、イソフタル酸、２，６－ナフタレンジカルボン酸、５－ナトリウムスルホイソフタル酸、５－テトラブチルホスホニウムスルホイソフタル酸などの多価カルボン酸類またはそれらの誘導体、エチレングリコール、プロピレングリコール、ブタンジオール、ペンタンジオール、ヘキサンジオール、オクタンジオール、ネオペンチルグリコール、グリセリン、トリメチロールプロパン、ペンタエリスリトール、トリメチロールプロパンまたはペンタエリスリトールにエチレンオキシドまたはプロピレンオキシドを付加した多価アルコール、ビスフェノールにエチレンオキシドを付加反応させた芳香族多価アルコール、ジエチレングリコール、トリエチレングリコール、ポリエチレングリコール、ポリプロピレングリコールなどの多価アルコール類またはそれらの誘導体、グリコール酸、３－ヒドロキシ酪酸、４－ヒドロキシ酪酸、４－ヒドロキシ吉草酸、６－ヒドロキシカプロン酸などのヒドロキシカルボン酸類、およびグリコリド、ε－カプロラクトングリコリド、ε－カプロラクトン、β－プロピオラクトン、δ－ブチロラクトン、β－またはγ－ブチロラクトン、ピバロラクトン、δ－バレロラクトンなどのラクトン類などが挙げられる
　本発明のポリ乳酸系シートは、ポリ乳酸を主体とする。ここでポリ乳酸系シートがポリ乳酸を主体とするとは、ポリ乳酸系シート中の全成分を１００質量％とした際に、ポリ乳酸を５０質量％以上１００質量％以下含むことを意味する。ポリ乳酸系シートは、ポリ乳酸系シート中の全成分を１００質量％とした際に、ポリ乳酸を８０質量％以上１００質量％以下含むことが好ましい。 The polylactic acid may contain components other than the lactic acid component (L-lactic acid component or D-lactic acid component) as long as the performance of the present invention is not impaired. Examples of other components include polycarboxylic acids, polyhydric alcohols, hydroxycarboxylic acids, and lactones. Specific examples include polysuccinic acids such as succinic acid, adipic acid, sebacic acid, fumaric acid, terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, 5-sodium sulfoisophthalic acid, and 5-tetrabutylphosphonium sulfoisophthalic acid. Carboxylic acids or their derivatives, ethylene glycol, propylene glycol, butanediol, pentanediol, hexanediol, octanediol, neopentylglycol, glycerin, trimethylolpropane, pentaerythritol, trimethylolpropane or pentaerythritol with ethylene oxide or propylene oxide Added polyhydric alcohol, aromatic polyhydric alcohol obtained by addition reaction of bisphenol with ethylene oxide, diethylene glycol, triethylene glycol, Polyhydric alcohols such as liethylene glycol and polypropylene glycol or derivatives thereof, hydroxycarboxylic acids such as glycolic acid, 3-hydroxybutyric acid, 4-hydroxybutyric acid, 4-hydroxyvaleric acid, 6-hydroxycaproic acid, and glycolide, ε -Caprolactone glycolide, ε-caprolactone, β-propiolactone, δ-butyrolactone, lactones such as β- or γ-butyrolactone, pivalolactone, δ-valerolactone and the like. Mainly. Here, that the polylactic acid-based sheet is mainly composed of polylactic acid means that when all the components in the polylactic acid-based sheet are 100% by mass, the polylactic acid is contained in an amount of 50% by mass to 100% by mass. The polylactic acid-based sheet preferably contains 80% by mass or more and 100% by mass or less of polylactic acid when all components in the polylactic acid-based sheet are 100% by mass.
　また、本発明のポリ乳酸系シートは、本発明の性能を損なわない範囲で、各種の添加剤を含有することができる。 Moreover, the polylactic acid-based sheet of the present invention can contain various additives as long as the performance of the present invention is not impaired.
　本発明のポリ乳酸系シートに含有可能な添加剤の例としては、充填剤（ガラス繊維、炭素繊維、金属繊維、天然繊維、有機繊維、ガラスフレーク、ガラスビーズ、セラミックスファイバー、セラミックビーズ、アスベスト、ワラステナイト、タルク、クレー、マイカ、セリサイト、ゼオライト、ベントナイト、モンモリロナイト、合成マイカ、ドロマイト、カオリン、微粉ケイ酸、長石粉、チタン酸カリウム、シラスバルーン、炭酸カルシウム、炭酸マグネシウム、硫酸バリウム、酸化カルシウム、酸化アルミニウム、酸化チタン、ケイ酸アルミニウム、酸化ケイ素、石膏、ノバキュライト、ドーソナイト、白土など）、紫外線吸収剤、熱安定剤、滑剤、離形剤、染料および顔料を含む着色剤、着色防止剤、難燃剤、導電剤あるいは着色剤、摺動性改良剤、帯電防止剤などが挙げられ、１種または２種以上を含有することができる。 Examples of additives that can be contained in the polylactic acid-based sheet of the present invention include fillers (glass fibers, carbon fibers, metal fibers, natural fibers, organic fibers, glass flakes, glass beads, ceramic fibers, ceramic beads, asbestos, Wollastonite, talc, clay, mica, sericite, zeolite, bentonite, montmorillonite, synthetic mica, dolomite, kaolin, finely divided silicic acid, feldspar powder, potassium titanate, shirasu balloon, calcium carbonate, magnesium carbonate, barium sulfate, calcium oxide , Aluminum oxide, titanium oxide, aluminum silicate, silicon oxide, gypsum, novaculite, dosonite, clay, etc.), UV absorbers, heat stabilizers, lubricants, mold release agents, coloring agents including dyes and pigments, anti-coloring agents, Flame retardant, conductive agent or colorant Sliding property improving agent, there may be mentioned, such as antistatic agent, it may contain one or two or more.
　また、本発明のポリ乳酸系シートは、必要に応じて本発明の性能を損なわない範囲で結晶核剤を１種または２種以上を含有することができる。本発明のポリ乳酸系シートに好適に含有される結晶核剤の例としては、タルクなどの無機系核剤、エチレンビスラウリン酸アミド、エチレンビス－１２－ジヒドロキシステアリン酸アミドおよびトリメシン酸トリシクロヘキシルアミドなどの有機アミド系化合物、銅フタロシアニンおよびピグメントイエロー１１０などの顔料系核剤、有機カルボン酸金属塩、フェニルホスホン酸亜鉛などが挙げられる。 Further, the polylactic acid-based sheet of the present invention can contain one or more crystal nucleating agents as long as the performance of the present invention is not impaired as required. Examples of the crystal nucleating agent suitably contained in the polylactic acid-based sheet of the present invention include inorganic nucleating agents such as talc, ethylene bislauric acid amide, ethylene bis-12-dihydroxystearic acid amide, and trimesic acid tricyclohexyl amide. Organic amide compounds such as copper phthalocyanine and pigment yellow 110, organic carboxylic acid metal salts, zinc phenylphosphonate and the like.
　本発明のポリ乳酸系シートは、必要に応じて本発明の性能を損なわない範囲で成形性改良剤を含有することができる。成形性改良剤としては、コア層とそれを覆う１層以上のシェル層から構成される多層構造重合体、ポリエーテルからなるセグメント及びポリ乳酸からなるセグメントから構成されるポリエーテル系ブロック共重合体、ポリエステルからなるセグメント及びポリ乳酸からなるセグメントから構成されるポリエステル系ブロック共重合体、脂肪族ポリエステル（ポリ乳酸を除く）、並びに脂肪族芳香族ポリエステルからなる群より選ばれる少なくとも１つを好適に用いることができる。 The polylactic acid-based sheet of the present invention can contain a moldability improving agent as long as it does not impair the performance of the present invention. As a moldability improver, a multilayer structure polymer composed of a core layer and one or more shell layers covering it, a polyether block copolymer composed of a segment composed of polyether and a segment composed of polylactic acid And at least one selected from the group consisting of polyester-based block copolymers composed of polyester segments and polylactic acid segments, aliphatic polyesters (excluding polylactic acid), and aliphatic aromatic polyesters. Can be used.
　ポリ乳酸の重量平均分子量は、特に限定されるものではないが、１０万以上３０万以下の範囲であることが、成形性および機械物性の点で好ましい。より好ましくは、ポリ乳酸の重量平均分子量は１２万以上２８万以下である。さらに好ましくは１３万以上２７万以下である。１４万以上２６万以下であることが特に好ましい。 The weight average molecular weight of polylactic acid is not particularly limited, but is preferably in the range of 100,000 to 300,000 in terms of moldability and mechanical properties. More preferably, the polylactic acid has a weight average molecular weight of 120,000 to 280,000. More preferably, it is 130,000 to 270,000. It is especially preferable that they are 140,000 or more and 260,000 or less.
　本発明のポリ乳酸系シートは、ポリ乳酸を主体とするが、ポリ乳酸としては、例えば、以下のＡ）又はＢ）の方法が好ましい。Ａ）ポリ乳酸として、ポリ－Ｌ－乳酸とポリ－Ｄ－乳酸の混合物を用いる。
Ｂ）ポリ乳酸として、ポリ－Ｌ－乳酸からなるセグメント及びポリ－Ｄ－乳酸からなるセグメントから構成されるポリ乳酸ブロック共重合体（以下、ポリ乳酸ブロック共重合体と称する。）を用いる。 The polylactic acid-based sheet of the present invention is mainly composed of polylactic acid. As polylactic acid, for example, the following method A) or B) is preferable. A) As polylactic acid, a mixture of poly-L-lactic acid and poly-D-lactic acid is used.
B) As the polylactic acid, a polylactic acid block copolymer (hereinafter referred to as a polylactic acid block copolymer) composed of a segment composed of poly-L-lactic acid and a segment composed of poly-D-lactic acid is used.
　Ａ）の方法は、ポリ乳酸が、ポリ－Ｌ－乳酸とポリ－Ｄ－乳酸を含むことである。Ｂ）の方法はポリ乳酸が、ポリ－Ｌ－乳酸からなるセグメント及びポリ－Ｄ－乳酸からなるセグメントから構成されるポリ乳酸ブロック共重合体を含むことである。 The method A) is that the polylactic acid contains poly-L-lactic acid and poly-D-lactic acid. In the method B), the polylactic acid contains a polylactic acid block copolymer composed of a segment composed of poly-L-lactic acid and a segment composed of poly-D-lactic acid.
　Ａ）又はＢ）の方法を用いることで、ポリ乳酸系シートの１６０℃における熱収縮率を０％～３０％として、さらに結晶化度を１％～３０％とすることができる。シートとした際により優れた透明性、耐熱性が得られるという点から、Ｂ）の方法、つまりポリ乳酸としてポリ乳酸ブロック共重合体を用いることが好ましい。 By using the method A) or B), the heat shrinkage rate of the polylactic acid-based sheet at 160 ° C. can be set to 0% to 30%, and the crystallinity can be further set to 1% to 30%. From the viewpoint that excellent transparency and heat resistance can be obtained when the sheet is formed, it is preferable to use a polylactic acid block copolymer as the method B), that is, polylactic acid.
　ポリ乳酸としてポリ－Ｌ－乳酸とポリ－Ｄ－乳酸の混合物を用いる場合の、ポリ乳酸の製造方法としては、ポリ－Ｌ－乳酸とポリ－Ｄ－乳酸とを溶融混練してなる混合物を製造することで可能であるが、この溶融混錬する方法は特に限定されるものではない。例えばポリ－Ｌ－乳酸とポリ－Ｄ－乳酸のうち、融点の高い方の成分の融解終了温度以上で溶融混練する方法がある。また、溶媒中で混合した後に溶媒を除く方法がある。あるいは溶融状態のポリ－Ｌ－乳酸とポリ－Ｄ－乳酸の少なくとも一方を、あらかじめ融点－５０℃～融点＋２０℃の温度範囲内で溶融機内にてせん断を付与しながら滞留させた後、ポリ－Ｌ－乳酸とポリ－Ｄ－乳酸とからなる混合物の結晶が残存するように混合する方法などがある。 In the case of using a mixture of poly-L-lactic acid and poly-D-lactic acid as polylactic acid, as a method for producing polylactic acid, a mixture obtained by melt-kneading poly-L-lactic acid and poly-D-lactic acid is produced. This is possible, but the method of melt kneading is not particularly limited. For example, there is a method of melt-kneading at a melting end temperature or higher of a component having a higher melting point among poly-L-lactic acid and poly-D-lactic acid. There is also a method of removing the solvent after mixing in the solvent. Alternatively, at least one of molten poly-L-lactic acid and poly-D-lactic acid is allowed to stay in the melting machine in advance within the temperature range of melting point −50 ° C. to melting point + 20 ° C. while being sheared, and then poly- There is a method of mixing so that crystals of a mixture of L-lactic acid and poly-D-lactic acid remain.
　ポリ－Ｌ－乳酸とポリ－Ｄ－乳酸のうち、融点の高い方の成分の融解終了温度以上で溶融混練する方法としては、ポリ－Ｌ－乳酸とポリ－Ｄ－乳酸とを回分法もしくは連続法で混合する方法が挙げられる。いずれの方法で混合してもよい。混練装置としては例えば、一軸押出機、二軸押出機、プラストミル、ニーダー、および減圧装置付き撹拌槽型反応機が挙げられる。均一かつ十分に混練できる観点においては二軸押出機を用いることが好ましい。 Among poly-L-lactic acid and poly-D-lactic acid, the method of melt-kneading at a temperature higher than the melting end temperature of the component having the higher melting point is poly-L-lactic acid and poly-D-lactic acid batchwise or continuously. The method of mixing by a method is mentioned. You may mix by any method. Examples of the kneading apparatus include a single screw extruder, a twin screw extruder, a plast mill, a kneader, and a stirred tank reactor equipped with a pressure reducing device. In view of uniform and sufficient kneading, it is preferable to use a twin screw extruder.
　また、ポリ乳酸としてポリ－Ｌ－乳酸とポリ－Ｄ－乳酸の混合物を用いる場合には、ポリ－Ｌ－乳酸とポリ－Ｄ－乳酸の質量比は、８０：２０～２０：８０であることが好ましい。７５：２５～２５：７５であることがより好ましい。さらには７０：３０～３０：７０であることが好ましい。特に６０：４０～４０：６０であることが最も好ましい。 When a mixture of poly-L-lactic acid and poly-D-lactic acid is used as polylactic acid, the mass ratio of poly-L-lactic acid to poly-D-lactic acid is 80:20 to 20:80. Is preferred. More preferably, it is 75:25 to 25:75. Further, it is preferably 70:30 to 30:70. In particular, it is most preferably 60:40 to 40:60.
　ポリ乳酸としてポリ－Ｌ－乳酸からなるセグメント及びポリ－Ｄ－乳酸からなるセグメントから構成されるポリ乳酸ブロック共重合体を用いる場合のポリ乳酸ブロック共重合体の製造方法は、特に限定されるものではなく、一般のポリ乳酸の製造方法を利用することができる。具体的には、ポリ－Ｌ－乳酸とポリ－Ｄ－乳酸を二軸押出機中で混合することで混合物を製造し、続いて該混合物を固相重合することによって前記ポリ乳酸ブロック共重合体を製造する方法があり、得られるシートの耐熱性や透明性が優れたものになる点で好ましい。また、原料の乳酸成分から生成した環状２量体のＬ－ラクチドまたはＤ－ラクチドのいずれか一方を触媒存在下で開環重合させ、さらに該ポリ乳酸の光学異性体であるラクチドを添加して開環重合させることで、ポリ乳酸ブロック共重合体を製造するラクチド法がある。また、ポリ－Ｌ－乳酸とポリ－Ｄ－乳酸を融点の高い方の成分の融解終了温度以上で長時間溶融混練を行うことで、Ｌ－乳酸成分のセグメントとＤ－乳酸成分のセグメントをエステル交換反応させてポリ乳酸ブロック共重合体を製造する方法がある。また、多官能性化合物をポリ－Ｌ－乳酸およびポリ－Ｄ－乳酸に混合して反応させることで、ポリ－Ｌ－乳酸とポリ－Ｄ－乳酸を多官能性化合物で共有結合させ、ポリ乳酸ブロック共重合体を製造する方法などがある。 The method for producing a polylactic acid block copolymer is particularly limited when a polylactic acid block copolymer composed of a segment composed of poly-L-lactic acid and a segment composed of poly-D-lactic acid is used as the polylactic acid. Instead, a general method for producing polylactic acid can be used. Specifically, the polylactic acid block copolymer is prepared by mixing poly-L-lactic acid and poly-D-lactic acid in a twin screw extruder, and subsequently solid-phase polymerizing the mixture. This is preferable in that the resulting sheet has excellent heat resistance and transparency. In addition, either of the cyclic dimer L-lactide or D-lactide generated from the raw lactic acid component is subjected to ring-opening polymerization in the presence of a catalyst, and lactide which is an optical isomer of the polylactic acid is added. There is a lactide method for producing a polylactic acid block copolymer by ring-opening polymerization. Also, poly-L-lactic acid and poly-D-lactic acid are melt-kneaded for a long time at a temperature equal to or higher than the melting end temperature of the component having a higher melting point, whereby the L-lactic acid component segment and the D-lactic acid component segment are esterified. There is a method for producing a polylactic acid block copolymer by an exchange reaction. In addition, poly-L-lactic acid and poly-D-lactic acid are covalently bonded with polyfunctional compound by mixing polyfunctional compound with poly-L-lactic acid and poly-D-lactic acid and reacting them. There is a method for producing a block copolymer.
　ポリ乳酸として、ポリ－Ｌ－乳酸からなるセグメントとポリ－Ｄ－乳酸からなるセグメントから構成されるポリ乳酸ブロック共重合体を用いる場合には、ポリ－Ｌ－乳酸からなるセグメントとポリ－Ｄ－乳酸からなるセグメントの質量比は、８０：２０～２０：８０であることが好ましい。７５：２５～２５：７５であることがより好ましい。さらには７０：３０～３０：７０であることが好ましい。特に６０：４０～４０：６０であることが最も好ましい。 When a polylactic acid block copolymer composed of a segment composed of poly-L-lactic acid and a segment composed of poly-D-lactic acid is used as polylactic acid, a segment composed of poly-L-lactic acid and poly-D- The mass ratio of the segments made of lactic acid is preferably 80:20 to 20:80. More preferably, it is 75:25 to 25:75. Further, it is preferably 70:30 to 30:70. In particular, it is most preferably 60:40 to 40:60.
　本発明のポリ乳酸系シートの１６０℃における熱収縮率は０％～３０％である。ポリ乳酸系シートの１６０℃における熱収縮率は、より好ましくはドローダウン抑制に大きな効果のある５％～３０％である。さらに好ましくは５％～２０％である。１６０℃における熱収縮率が０％より小さいと、シートが伸びるためにドローダウンが大きくなることがある。また、１６０℃における熱収縮率が３０％を越えると、後の成形工程で成形性が低下することがある。 The heat shrinkage rate of the polylactic acid sheet of the present invention at 160 ° C. is 0% to 30%. The heat shrinkage rate at 160 ° C. of the polylactic acid-based sheet is more preferably 5% to 30%, which has a great effect on suppressing drawdown. More preferably, it is 5% to 20%. If the heat shrinkage rate at 160 ° C. is less than 0%, the drawdown may increase because the sheet stretches. On the other hand, if the heat shrinkage rate at 160 ° C. exceeds 30%, the moldability may deteriorate in the subsequent molding step.
　前述のポリ乳酸ブロック共重合体を用いる方法、前述のポリ－Ｌ－乳酸とポリ－Ｄ－乳酸の混合物を用いる方法の他に、本発明のポリ乳酸系シートの１６０℃における熱収縮率を０％～３０％にする方法としては、ポリ乳酸を主体とするシート状物を形成する工程、９０℃～２００℃で熱処理する工程、延伸する工程をこの順に有する製造方法によってポリ乳酸系シートを製造する方法を挙げることができる。熱処理する工程と延伸する工程は、連続的に行う方法でも、熱処理する工程の後にシートを一旦巻き取ってから延伸する工程を行うでも、いずれも好ましく採用できる。 In addition to the method using the polylactic acid block copolymer described above and the method using the mixture of poly-L-lactic acid and poly-D-lactic acid described above, the heat shrinkage rate of the polylactic acid-based sheet of the present invention at 160 ° C. is 0. As a method for making the content 30% to 30%, a polylactic acid-based sheet is produced by a production method having a step of forming a sheet-like material mainly composed of polylactic acid, a step of heat treatment at 90 ° C. to 200 ° C., and a step of stretching. The method of doing can be mentioned. The step of heat treatment and the step of stretching can be preferably employed either by a continuous method or by a step of winding and then stretching the sheet after the step of heat treatment.
　本発明のポリ乳酸系シートの結晶化度は１％～３０％である。ポリ乳酸系シートの結晶化度は、より好ましくは５％～２５％である。結晶化度が１％未満だとドローダウンが大きくなることがあり、３０％を越えると成形性が不良となることがある。 The crystallinity of the polylactic acid sheet of the present invention is 1% to 30%. The degree of crystallinity of the polylactic acid-based sheet is more preferably 5% to 25%. If the crystallinity is less than 1%, drawdown may increase, and if it exceeds 30%, moldability may be poor.
　前述のポリ乳酸ブロック共重合体、前述のポリ－Ｌ－乳酸とポリ－Ｄ－乳酸の混合物を用いる方法の他に、ポリ乳酸系シートの結晶化度を１％～３０％に制御するためには、熱処理する工程を９０℃～２００℃で行う方法や、熱処理時間を後述するように調整する方法で可能である。 In addition to the method using the polylactic acid block copolymer described above and the mixture of poly-L-lactic acid and poly-D-lactic acid described above, in order to control the crystallinity of the polylactic acid-based sheet to 1% to 30%. Is possible by a method of performing the heat treatment at 90 ° C. to 200 ° C. or a method of adjusting the heat treatment time as described later.
　本発明のポリ乳酸系シートは、ポリ乳酸を主体とするシート状物を形成する工程、９０℃～２００℃で熱処理する工程、延伸する工程をこの順に有する製造方法によって製造することが好ましい。 The polylactic acid-based sheet of the present invention is preferably produced by a production method having a step of forming a sheet-like material mainly composed of polylactic acid, a step of heat treatment at 90 ° C. to 200 ° C., and a step of stretching.
　ポリ乳酸を主体とするシート状物を形成する工程は特に限定されず、例えば、ベント式押出機に、ポリ乳酸を供給し、真空ベント部を脱気しながら溶融混練した後、フィルターにてポリマーを濾過させ、先端が烏口の形状をした口金から押出し、キャストドラムに密着させた後に巻き取る方法などが好ましく採用される。 The step of forming a sheet-like material mainly composed of polylactic acid is not particularly limited. For example, after supplying polylactic acid to a vent type extruder and melt-kneading while degassing the vacuum vent part, the polymer is filtered. For example, a method is preferably employed in which the material is filtered, extruded from a mouthpiece having a tip-shaped shape, and wound onto the cast drum after closely contacting the cast drum.
　熱処理する工程における加熱する方法は特に限定しないが、加熱オーブン、テンター式加熱オーブンで行う加熱や加熱ロールで行う加熱が好ましい。 The method of heating in the heat treatment step is not particularly limited, but heating in a heating oven or a tenter heating oven or heating with a heating roll is preferable.
　加熱ロールにより加熱する方法では、シートと加熱ロールの粘着を防止するために、シリコンゴム被覆ロール、シリコーン処理したロール、フッ素処理したロール、サンドブラスト処理によりロール表面を粗面化したロールなどの非粘着ロールを、加熱ロールとして使用することが好ましい。 In the method of heating with a heating roll, in order to prevent adhesion between the sheet and the heating roll, non-adhesive such as a silicon rubber coated roll, a silicone-treated roll, a fluorine-treated roll, and a roll whose surface is roughened by sandblasting The roll is preferably used as a heating roll.
　また、加熱オーブンやテンター式加熱オーブンにより加熱する方法では、熱風による方法や遠赤外ヒータによる方法、これらの組み合わせによる方法等が好ましく採用できる。 In addition, as a method of heating with a heating oven or a tenter type heating oven, a method using hot air, a method using a far infrared heater, a method using a combination of these, or the like can be preferably employed.
　加熱オーブンにより加熱する方法においても、オーブン内にガイドロール等が設置されている場合は、ガイドロールとして非粘着ロールを採用することが好ましい。オーブン内のガイドロールへの粘着の懸念から、オーブン内にガイドロールが設置されていないフローティング乾燥機で加熱を行うことが特に好ましく採用できる。 Also in the method of heating with a heating oven, when a guide roll or the like is installed in the oven, it is preferable to employ a non-adhesive roll as the guide roll. From the concern of sticking to the guide roll in the oven, it is particularly preferable to use a floating dryer in which no guide roll is installed in the oven.
　熱処理する工程における熱処理温度は、ドローダウンを抑制するために９０℃～２００℃が好ましく、より好ましくは１００℃～１８０℃である。熱処理温度が９０℃より小さいと十分な結晶化度が得られないため、すなわち結晶化度を１％～３０％にすることができないために、ドローダウンが大きくなることがある。また、熱処理温度が２００℃を越えるとシートが軟化するために十分な結晶化度が得られず、すなわち、結晶化度を１％～３０％にすることができず、ドローダウンが大きくなることがある。 The heat treatment temperature in the heat treatment step is preferably 90 ° C. to 200 ° C., more preferably 100 ° C. to 180 ° C. in order to suppress drawdown. If the heat treatment temperature is lower than 90 ° C., a sufficient crystallinity cannot be obtained, that is, the crystallinity cannot be made 1% to 30%, so that drawdown may be increased. Further, if the heat treatment temperature exceeds 200 ° C., the sheet is softened, so that sufficient crystallinity cannot be obtained, that is, the crystallinity cannot be made 1% to 30%, and the drawdown becomes large. There is.
　熱処理する工程における熱処理時間は、ポリ乳酸系シートの結晶化度を１％～３０％に制御するために、５秒～５分間が好ましく、５秒～３分間がより好ましい。熱処理時間が５秒より小さいと十分な結晶化度が得られないことがあり、５分を越えると生産性が劣ることがある。 The heat treatment time in the heat treatment step is preferably 5 seconds to 5 minutes, and more preferably 5 seconds to 3 minutes in order to control the crystallinity of the polylactic acid sheet to 1% to 30%. If the heat treatment time is less than 5 seconds, sufficient crystallinity may not be obtained, and if it exceeds 5 minutes, productivity may be inferior.
　熱処理後の延伸する工程における延伸する方法は特に限定しないが、加熱ロールやテンター式延伸機で延伸することが好ましい。中でもテンター式延伸機で行うことが好ましい。加熱ロールにより行う場合は、加熱ロールの周速差により長さ方向に行う。また、テンター式延伸機によって熱処理後の延伸を行う場合は、把持されたシートを横方向に幅を拡大変更して行う。 The stretching method in the stretching step after the heat treatment is not particularly limited, but stretching with a heating roll or a tenter type stretching machine is preferable. Among these, it is preferable to carry out with a tenter type stretching machine. When performing with a heating roll, it is performed in the length direction due to the peripheral speed difference of the heating roll. Moreover, when extending | stretching after heat processing with a tenter-type extending | stretching machine, the width | variety is expanded and changed to the hold | gripped sheet | seat.
　延伸する工程における延伸温度は、ドローダウンを抑制するために７０℃～２００℃が好ましく、より好ましくは７０℃～１８０℃、更に好ましくは７０℃～１６０℃である。延伸温度が７０℃より小さいと延伸応力が高くなることがあり、２００℃を越えるシートが軟化してドローダウンが大きくなることがある。 The stretching temperature in the stretching step is preferably 70 ° C. to 200 ° C., more preferably 70 ° C. to 180 ° C., and further preferably 70 ° C. to 160 ° C. in order to suppress drawdown. If the stretching temperature is lower than 70 ° C., the stretching stress may be increased, and the sheet exceeding 200 ° C. may be softened to increase the drawdown.
　延伸する工程における延伸倍率は、ドローダウンを抑制するために１．１倍～３．０倍が好ましい。より好ましくは１．１倍～２．０倍である。更に好ましくは１．１倍～１．５倍である。延伸倍率が１．１倍より小さいとドローダウンが大きくなることがある。３．０倍を越えると収縮量が大きくなりすぎて後の成形性が低下することがある。 The stretching ratio in the stretching step is preferably 1.1 to 3.0 times in order to suppress drawdown. More preferably, it is 1.1 times to 2.0 times. More preferably, it is 1.1 times to 1.5 times. If the draw ratio is less than 1.1 times, the drawdown may increase. If it exceeds 3.0 times, the shrinkage amount becomes too large, and the subsequent formability may deteriorate.
　延伸する工程における予熱工程は、９０℃～２００℃に加熱されていれば、熱処理する工程と解される。また、延伸倍率がわずかであり、９０℃～２００℃に加熱されていれば、熱処理工程と解される。 The preheating step in the stretching step is understood as a heat treatment step if it is heated to 90 ° C to 200 ° C. Further, if the draw ratio is slight and the film is heated to 90 ° C. to 200 ° C., it is understood as a heat treatment step.
　ポリ乳酸系シートの面配向係数ｆｎは０．１×１０－２～５×１０－２が好ましい。より好ましくは０．５×１０－２～３×１０－２である。面配向係数が０．１×１０－２未満であるとドローダウンが大きくなることがある。５×１０－２を越えると成形性が不良となることがある。面配向係数ｆｎを０．１×１０－２～５×１０－２にする方法としては、ポリ乳酸を主体とするシート状物を形成する工程の後に、９０℃～２００℃で熱処理する工程を設け、該熱処理する工程の後に延伸する工程を設けることにより、達成可能である。 The plane orientation coefficient fn of the polylactic acid based sheet is preferably 0.1 × 10 −2 to 5 × 10 −2 . More preferably, it is 0.5 × 10 −2 to 3 × 10 −2 . When the plane orientation coefficient is less than 0.1 × 10 −2 , drawdown may increase. If it exceeds 5 × 10 −2 , moldability may be poor. As a method for setting the plane orientation coefficient fn to 0.1 × 10 −2 to 5 × 10 −2 , a step of performing a heat treatment at 90 ° C. to 200 ° C. after the step of forming a sheet-like material mainly composed of polylactic acid. This can be achieved by providing a step of stretching after the step of providing and heat-treating.
　ポリ乳酸系シートのステレオ化率は８０％～１００％が好ましい。より好ましくは９０％～１００％である。ステレオ化率が８０％未満であるとドローダウンが大きくなることがある。ステレオ化率を８０％～１００％にする方法は、ポリ乳酸を主体とするシートを９０℃～２００℃で熱処理する工程の後に延伸する工程を設けることにより、達成することが可能である。 The stereoification rate of the polylactic acid sheet is preferably 80% to 100%. More preferably, it is 90% to 100%. If the stereo ratio is less than 80%, the drawdown may increase. The method of setting the stereo ratio to 80% to 100% can be achieved by providing a drawing step after the step of heat-treating a sheet mainly composed of polylactic acid at 90 ° C. to 200 ° C.
　［特性の測定方法および効果の評価方法］
本発明における特性の測定方法及び効果の評価方法は次のとおりである。 [Characteristic measurement method and effect evaluation method]
The characteristic measuring method and the effect evaluating method in the present invention are as follows.
　（１）１６０℃における熱収縮率（％）
シートからシート長手方向に幅４ｍｍの短冊状サンプルを切り出し、熱機械分析装置（ＳＩＩ社製　ＴＭＡ６１００）を用いて、荷重２９．６ｍＮ／ｍｍ２、昇温速度１０Ｋ／ｍｉｎ、サンプル長２０ｍｍ設定の条件で測定を行って１６０℃での収縮量を求めた。そして、式（１）により１６０℃における熱収縮率を求めた。 (1) Thermal shrinkage at 160 ° C. (%)
A strip-like sample having a width of 4 mm is cut out from the sheet in the longitudinal direction of the sheet, and using a thermomechanical analyzer (TMA6100 manufactured by SII), a load is set to 29.6 mN / mm 2 , a temperature rising rate is 10 K / min, and a sample length is set to 20 mm. Was measured to determine the amount of shrinkage at 160 ° C. And the thermal contraction rate in 160 degreeC was calculated | required by Formula (1).
　熱収縮率（％）＝　１６０℃での収縮量／２５℃でのサンプル長　×　１００　・・・式（１）
　（２）結晶化度（％）
Ｘ線回折装置（Ｂｒｕｋｅｒ　ＡＸＳ社製 Ｄ８　ＡＤＶＡＮＣＥ）にて、広角Ｘ線回折法（２θ－θスキャン法）により得られた回折ピークについて、非晶部分に伴う回折曲線をベースラインとして、２θが１０～３０度の総面積（Ｓtotal）を求めるとともに、非晶部分に伴う回折曲線の面積を求め、下記式より結晶化度を求めた。 Thermal shrinkage rate (%) = Shrinkage amount at 160 ° C./Sample length at 25 ° C. × 100 Expression (1)
(2) Crystallinity (%)
With respect to a diffraction peak obtained by a wide-angle X-ray diffraction method (2θ-θ scan method) with an X-ray diffractometer (D8 ADVANCE manufactured by Bruker AXS), 2θ is 10 based on the diffraction curve associated with the amorphous portion. The total area (Stotal) of ˜30 degrees was determined, the area of the diffraction curve associated with the amorphous part was determined, and the crystallinity was determined from the following formula.
　結晶化度（％）　＝　Ｓｔｏｔａｌ／（Ｓtotal＋非晶部分に伴う回折曲線の面積）×１００
　なお測定条件の詳細は以下の通りである。
Ｘ線源：ＣｕＫα線
出力：４０ｋＶ、４０ｍＡ
スリット径：ＤＳ＝ＳＳ＝１度、ＲＳ＝０．６ｍｍ、ＲＳｍ＝１ｍｍ
検出器：シンチレーションカウンター
測定範囲：５～８０度
ステップ幅（２θ）：０．０５度
　（３）面配向係数（ｆｎ）
アッベ屈折計によってシート長手方向、幅方向、厚み方向の屈折率（それぞれＮｘ、Ｎｙ、Ｎｚ）を測定し、次式で算出した。
ｆｎ＝（Ｎｘ＋Ｎｙ）／２－Ｎｚ　
　（４）融点、ステレオ化率（％）
ポリ乳酸の融点は、パーキンエルマー社示差走査型熱量計（ＤＳＣ）により測定した。測定条件は、試料５ｍｇ、窒素雰囲気下、昇温速度が２０℃／分である。ここで、融点とは、結晶融解ピークにおけるピークトップの温度のことを指す。 Crystallinity (%) = Total / (Stotal + area of diffraction curve associated with amorphous part) × 100
The details of the measurement conditions are as follows.
X-ray source: CuKα ray output: 40 kV, 40 mA
Slit diameter: DS = SS = 1 degree, RS = 0.6 mm, RSm = 1 mm
Detector: Scintillation counter Measurement range: 5 to 80 degrees Step width (2θ): 0.05 degrees (3) Plane orientation coefficient (fn)
Refractive indexes (Nx, Ny, and Nz) in the sheet longitudinal direction, width direction, and thickness direction were measured with an Abbe refractometer, and calculated by the following equations.
fn = (Nx + Ny) / 2−Nz
(4) Melting point, stereo ratio (%)
The melting point of polylactic acid was measured with a differential scanning calorimeter (DSC) manufactured by PerkinElmer. The measurement conditions are 5 mg of the sample, a nitrogen atmosphere, and a heating rate of 20 ° C./min. Here, the melting point refers to the temperature of the peak top in the crystal melting peak.
　またここで示す融点は、１回目の測定（１ｓｔＲＵＮ）で昇温速度２０℃／分で３０℃から２５０℃まで昇温した後、降温速度９９９℃／分で３０℃まで冷却し、さらに２回目の測定（２ｎｄＲＵＮ）で昇温速度２０℃／分で３０℃から２５０℃まで昇温したときに測定される融点とした。 In addition, the melting point shown here is the first measurement (1stRUN), the temperature is increased from 30 ° C. to 250 ° C. at a temperature increase rate of 20 ° C./min, and then cooled to 30 ° C. at a temperature decrease rate of 999 ° C./min. In this measurement (2ndRUN), the melting point was measured when the temperature was increased from 30 ° C. to 250 ° C. at a temperature increase rate of 20 ° C./min.
　また、シートのステレオ化率は、上記融点の測定方法と同条件でのシートの融点の測定方法において測定される１９０℃以上２３０℃未満にピークを有する吸熱曲線の融解エンタルピー（△Ｈｓｃ）および１５０℃以上１８５℃未満にピークを有する吸熱曲線の融解エンタルピー（△Ｈｈｏｍｏ）を用いて、式（２）よりされる値を指す。 Further, the sheet stereoization rate is determined by the melting enthalpy (ΔHsc) of the endothermic curve having a peak at 190 ° C. or higher and lower than 230 ° C. measured by the method for measuring the melting point of the sheet under the same conditions as the above-described melting point measurement method. It refers to the value obtained from the equation (2) using the melting enthalpy (ΔHomo) of an endothermic curve having a peak at a temperature of from ℃ to 185 ° C.
　Ｓｃ　＝　１００ ×　△Ｈｓｃ／（△Ｈｓｃ＋△Ｈｈｏｍｏ）　・・・・・式（２）
　（５）ドローダウン量（ｃｍ）、シートの成形性
　ドローダウン量（ｃｍ）
幅３２０ｍｍ、長さ４６０ｍｍの枚葉シートサンプルを、開口部１５０ｍｍ×２１０ｍｍ、底面部１０５ｍｍ×１９６ｍｍ、高さ５０ｍｍのトレー状金型を備えた成光産業（株）製小型真空成形機フォーミング３００Ｘ型を用いて、成形時のシート温度が２００℃になるように予熱を行った。その時のシートの垂下がりの最大部分を定規で測定してドローダウン量とした。
次にこの予熱されたシートを成形して下記のように評価した。 Sc = 100 × ΔHsc / (ΔHsc + ΔHomo) (2)
(5) Drawdown amount (cm), sheet formability Drawdown amount (cm)
Forming 300X type small vacuum forming machine manufactured by Seiko Sangyo Co., Ltd. equipped with a tray-like mold having a width of 320 mm and a length of 460 mm, an opening of 150 mm × 210 mm, a bottom of 105 mm × 196 mm, and a height of 50 mm Was used to preheat the sheet at the time of molding to 200 ° C. The maximum portion of the sheet hanging at that time was measured with a ruler to obtain the drawdown amount.
The preheated sheet was then molded and evaluated as follows.
　シートの成形性
Ｓ（非常に良好）：シートがトレー状の成形体の底面部まで十分に追従するよう成形されている。
Ａ（良好）：シートがトレー状の底面部まで十分に追従するよう成形されているが、厚みムラが大きい。
Ｂ（成形不良）：シートがトレー状の底面部まで十分に追従成形されない、あるいは、追従成形されていても該底面部でのシート破断が確認される。 Sheet moldability S (very good): The sheet is molded so as to sufficiently follow the bottom surface of the tray-shaped molded body.
A (good): The sheet is formed so as to sufficiently follow the bottom surface of the tray, but the thickness unevenness is large.
B (Molding failure): The sheet is not sufficiently track-formed to the bottom surface of the tray, or even if the sheet is track-formed, breakage of the sheet at the bottom surface is confirmed.
　（６）重量平均分子量
ポリ乳酸の重量平均分子量は、ゲルパーミエーションクロマトグラフィー（ＧＰＣ）により測定した標準ポリメチルメタクリレート換算の値である。ＧＰＣ測定は、検出器にＷＡＴＥＲＳ社製の示差屈折計ＷＡＴＥＲＳ４１０を用い、ポンプにＷＡＴＥＲＳ社製のＭＯＤＥＬ５１０を用い、カラムに昭和電工株式会社製のＳｈｏｄｅｘ（登録商標）　ＧＰＣ　ＨＦＩＰ－８０６ＭとＳｈｏｄｅｘ（登録商標）　ＧＰＣ　ＨＦＩＰ－ＬＧとを直列に接続したものを用いて行った。測定条件は、流速０．５ｍＬ／ｍｉｎとし、測定では溶媒にヘキサフルオロイソプロパノールを用い、試料濃度１ｍｇ／ｍＬの溶液を０．１ｍＬ注入した。 (6) Weight average molecular weight The weight average molecular weight of polylactic acid is a standard polymethyl methacrylate conversion value measured by gel permeation chromatography (GPC). For GPC measurement, a differential refractometer WATERS410 manufactured by WATERS is used as a detector, a MODEL510 manufactured by WATERS is used as a pump, and Shodex (registered trademark) GPC HFIP-806M and Shodex (registered trademark) manufactured by Showa Denko KK are used as a column. ) GPC HFIP-LG was used in series. The measurement conditions were a flow rate of 0.5 mL / min, and in the measurement, hexafluoroisopropanol was used as a solvent, and 0.1 mL of a solution having a sample concentration of 1 mg / mL was injected.
　次に実施例および比較例に基づいて本発明を説明するが、本発明はこれらに限定されるものではない。 Next, the present invention will be described based on Examples and Comparative Examples, but the present invention is not limited to these.
　本発明の製造例、実施例、比較例で用いた原料は下記の通りである。なお、製造例、実施例、比較例では下記の略称で表記することがある。
Ａ１：製造例１（ポリ－Ｌ－乳酸とポリ－Ｄ－乳酸の混合物）
Ａ２：製造例２（ポリ－Ｌ－乳酸からなるセグメント及びポリ－Ｄ－乳酸からなるセグメントから構成されるポリ乳酸ブロック共重合体）
　［製造例１］（Ａ１の製造例）
　撹拌装置と還流装置を備えた反応容器中に、９０質量％Ｌ－乳酸水溶液を５０質量部入れ、温度を１５０℃にした後、徐々に減圧して水を留去しながら３．５時間反応した。その後、窒素雰囲気下で常圧にし、酢酸スズ（ＩＩ）０．０２質量部を添加した後、１７０℃にて１３Ｐａになるまで徐々に減圧しながら７時間重合反応を行い、ポリ－Ｌ－乳酸（ＰＬＬＡ１）を得た。ＰＬLＡ１の重量平均分子量は１．８万、融点は１４９℃であった。 The raw materials used in the production examples, examples, and comparative examples of the present invention are as follows. In the production examples, examples, and comparative examples, the following abbreviations may be used.
A1: Production Example 1 (mixture of poly-L-lactic acid and poly-D-lactic acid)
A2: Production Example 2 (polylactic acid block copolymer composed of a segment composed of poly-L-lactic acid and a segment composed of poly-D-lactic acid)
[Production Example 1] (Production Example of A1)
In a reaction vessel equipped with a stirrer and a reflux device, 50 parts by mass of a 90% by mass L-lactic acid aqueous solution was added, the temperature was raised to 150 ° C., and the reaction was continued for 3.5 hours while gradually reducing the pressure to distill off water. did. Thereafter, the pressure is changed to normal pressure in a nitrogen atmosphere, 0.02 part by mass of tin (II) acetate is added, and a polymerization reaction is performed for 7 hours while gradually reducing the pressure to 170 Pa at 170 ° C. to obtain poly-L-lactic acid. (PLLA1) was obtained. PLLA1 had a weight average molecular weight of 18,000 and a melting point of 149 ° C.
　得られたＰＬＬＡ１を、窒素雰囲気下１１０℃で１時間結晶化処理を行った後、６０Ｐａの圧力下、１４０℃で３時間、１５０℃で３時間、１６０℃で１８時間固相重合を行い、ポリ－Ｌ－乳酸（ＰＬＬＡ２）を得た。ＰＬＬＡ２の重量平均分子量は２０．３万、融点は１７０℃であった。 The obtained PLLA1 was subjected to crystallization treatment at 110 ° C. for 1 hour in a nitrogen atmosphere, followed by solid phase polymerization under a pressure of 60 Pa for 3 hours at 140 ° C., 3 hours at 150 ° C., and 18 hours at 160 ° C., Poly-L-lactic acid (PLLA2) was obtained. PLLA2 had a weight average molecular weight of 203,000 and a melting point of 170 ° C.
　次に、撹拌装置と還流装置を備えた反応容器中に、９０質量％Ｄ－乳酸水溶液を５０質量部入れ、温度を１５０℃にした後、徐々に減圧して水を留去しながら３．５時間反応した。その後、窒素雰囲気下で常圧にし、酢酸スズ（ＩＩ）０．０２質量部を添加した後、１７０℃にて１３Ｐａになるまで徐々に減圧しながら７時間重合反応を行い、ポリ－Ｄ－乳酸（ＰＤＬＡ１）を得た。ＰＤＬＡ１の重量平均分子量は１．７万、融点は１４８℃であった。 Next, 50 parts by mass of a 90% by mass D-lactic acid aqueous solution is placed in a reaction vessel equipped with a stirrer and a reflux apparatus, and the temperature is set to 150 ° C. Then, the pressure is gradually reduced and water is distilled off. Reacted for 5 hours. Thereafter, the pressure is brought to normal pressure in a nitrogen atmosphere, 0.02 part by mass of tin (II) acetate is added, and then a polymerization reaction is carried out for 7 hours while gradually reducing the pressure to 170 Pa at 13 ° C. to obtain poly-D-lactic acid. (PDLA1) was obtained. PDLA1 had a weight average molecular weight of 17,000 and a melting point of 148 ° C.
　得られたＰＤＬＡ１を、窒素雰囲気下１１０℃で１時間結晶化のための熱処理を行った後、６０Ｐａの圧力下、１４０℃で３時間、１５０℃で３時間、１６０℃で１４時間固相重合を行い、ポリ－Ｌ－乳酸（ＰＤＬＡ２）を得た。ＰＤＬＡ２の重量平均分子量は１５．８万、融点は１６８℃であった。 The obtained PDLA1 was subjected to a heat treatment for crystallization in a nitrogen atmosphere at 110 ° C. for 1 hour, followed by solid state polymerization under a pressure of 60 Pa for 3 hours at 140 ° C., 3 hours at 150 ° C., and 14 hours at 160 ° C. To obtain poly-L-lactic acid (PDLA2). PDLA2 had a weight average molecular weight of 1580,000 and a melting point of 168 ° C.
　次に、ＰＬＬＡ２とＰＤＬＡ２を、あらかじめ窒素雰囲気下で温度１１０℃、２時間結晶化のための熱処理を行っておき、ＰＬＬＡ２／ＰＤＬＡ２を７０／３０の質量比になるように配合し、触媒失活剤（アデカ製、“アデカスタブ”ＡＸ－７１）をＰＬＬＡ２とＰＤＬＡ２の合計１００質量部に対し０．５質量部をドライブレンドした後、シリンダー温度を２４０℃、スクリュー回転数を１００ｒｐｍに設定した、２ヶ所のニーディングブロック部を有するＰＣＭ３０二軸押出機で溶融混練し、ダイスから吐出されたストランドを冷却バス内で冷却した後、ストランドカッターにてペレット化することで、ペレット状のポリ乳酸Ａ１を得た。ポリ乳酸Ａ１の重量平均分子量、融点は表１に示す通りであった。なお、得られたＡ１は圧力１３．３Ｐａ、１１０℃で２時間、１４０℃で６時間結晶化処理を行った。 Next, PLLA2 and PDLA2 are preliminarily subjected to heat treatment for crystallization at a temperature of 110 ° C. for 2 hours in a nitrogen atmosphere, and PLLA2 / PDLA2 is blended to a mass ratio of 70/30 to deactivate the catalyst. 0.5 parts by mass of an agent (manufactured by Adeka, “Adeka Stub” AX-71) was dry blended with respect to a total of 100 parts by mass of PLLA2 and PDLA2, and then the cylinder temperature was set to 240 ° C. and the screw rotation speed was set to 100 rpm. After melt-kneading with a PCM30 twin-screw extruder having a kneading block part, the strand discharged from the die is cooled in a cooling bath, and then pelletized with a strand cutter, so that the pellet-shaped polylactic acid A1 is obtained. Obtained. The weight average molecular weight and melting point of polylactic acid A1 were as shown in Table 1. The obtained A1 was subjected to crystallization treatment at a pressure of 13.3 Pa, 110 ° C. for 2 hours, and 140 ° C. for 6 hours.
　［製造例２］（Ａ２の製造例）
　Ａ２はポリ－Ｌ－乳酸とポリ－Ｄ－乳酸を二軸押出機中で混合することで混合物を製造する工程、該混合物を固相重合することによって前記ポリ乳酸ブロック共重合体を製造した。具体的には製造例１で得られたＰＤＬＡ１を、窒素雰囲気下１１０℃で１時間結晶化のための熱処理を行った後、６０Ｐａの圧力下、１４０℃で３時間、１５０℃で３時間、１６０℃で６時間固相重合を行い、ポリ－Ｄ－乳酸（ＰＤＬＡ３）を得た。ＰＤＬＡ３の重量平均分子量は４．２万、融点は１５８℃であった。 [Production Example 2] (Production Example of A2)
A2 was a step of producing a mixture by mixing poly-L-lactic acid and poly-D-lactic acid in a twin screw extruder, and the polylactic acid block copolymer was produced by solid-phase polymerization of the mixture. Specifically, PDLA1 obtained in Production Example 1 was subjected to a heat treatment for crystallization in a nitrogen atmosphere at 110 ° C. for 1 hour, and then at a pressure of 60 Pa, 140 ° C. for 3 hours, 150 ° C. for 3 hours, Solid phase polymerization was performed at 160 ° C. for 6 hours to obtain poly-D-lactic acid (PDLA3). PDLA3 had a weight average molecular weight of 42,000 and a melting point of 158 ° C.
　製造例１で得られたＰＬＬＡ２とＰＤＬＡ３とを、あらかじめ窒素雰囲気下で温度１１０℃、２時間結晶化のための熱処理を行っておき、ＰＬＬＡ２をＴＥＸ３０α二軸押出機（日本製鋼所製）の樹脂供給口より添加し、ＰＤＬＡ３をＬ／Ｄ＝３０の部分に設けたサイド供給口より添加し溶融混練を行った。ＰＬＬＡ２とＰＤＬＡ３の質量比率は、７０／３０である。二軸押出機は、樹脂供給口よりＬ／Ｄ＝１０の部分に温度１８０℃に設定した可塑化部分を設け、Ｌ／Ｄ＝３０の部分にはニーディングディスクを備えてせん断付与できるスクリューとしてせん断付与下で混合できる構造をしており、ＰＬＬＡ２とＰＤＬＡ３の混合はせん断付与下、混合温度２００℃で行った。ダイスから吐出されたストランドを冷却バス内で冷却した後、ストランドカッターにてペレット化することで、ペレット状の溶融混練ポリ乳酸を得た。 The PLLA2 and PDLA3 obtained in Production Example 1 were preliminarily heat-treated for crystallization at a temperature of 110 ° C. for 2 hours in a nitrogen atmosphere, and the PLLA2 was a resin of a TEX30α twin screw extruder (manufactured by Nippon Steel Works). It added from the supply port, PDLA3 was added from the side supply port provided in the part of L / D = 30, and melt-kneading was performed. The mass ratio of PLLA2 and PDLA3 is 70/30. The twin screw extruder is provided with a plasticizing part set at a temperature of 180 ° C. at a part where L / D = 10 from the resin supply port, and a kneading disk is provided at a part where L / D = 30 as a screw capable of applying shear. The structure can be mixed under shearing, and PLLA2 and PDLA3 were mixed at a mixing temperature of 200 ° C. under shearing. The strand discharged from the die was cooled in a cooling bath, and then pelletized by a strand cutter to obtain pellet-shaped melt-kneaded polylactic acid.
　得られた溶融混練ポリ乳酸を真空乾燥機中、１１０℃にて圧力１３．３Ｐａで２時間乾燥後、１４０℃にて圧力１３．３Ｐａで４時間固相重合を行い、次いで１５０℃に昇温して４時間、さらに１６０℃に昇温して１０時間固相重合を行い、ポリ乳酸ブロック共重合体を得た。次いで、触媒失活剤（アデカ製、“アデカスタブ”ＡＸ－７１）を得られたポリ乳酸ブロック共重合体１００質量部に対し０．５質量部をドライブレンドした後、シリンダー温度を２４０℃、スクリュー回転数を１００ｒｐｍに設定した、２ヶ所のニーディングブロック部を有するＰＣＭ３０二軸押出機で溶融混練し、ダイスから吐出されたストランドを冷却バス内で冷却した後、ストランドカッターにてペレット化することで、ペレット状のポリ乳酸Ａ２を得た。ポリ乳酸Ａ２の重量平均分子量、融点は表1に示す通りであった。なお、圧力１３．３Ｐａ、１１０℃で２時間、１４０℃で６時間結晶化処理を行った。 The obtained melt-kneaded polylactic acid was dried in a vacuum dryer at 110 ° C. and a pressure of 13.3 Pa for 2 hours, then subjected to solid state polymerization at 140 ° C. and a pressure of 13.3 Pa for 4 hours, and then heated to 150 ° C. Then, the temperature was further raised to 160 ° C. for 4 hours and solid phase polymerization was performed for 10 hours to obtain a polylactic acid block copolymer. Next, 0.5 parts by mass of 100 parts by mass of the polylactic acid block copolymer obtained from the catalyst deactivator (manufactured by ADEKA, “ADEKA STAB” AX-71) was dry-blended, and the cylinder temperature was 240 ° C. Melting and kneading with a PCM30 twin-screw extruder with two kneading block parts set at a rotation speed of 100 rpm, cooling the strand discharged from the die in a cooling bath, and then pelletizing with a strand cutter Thus, pellet-shaped polylactic acid A2 was obtained. The weight average molecular weight and melting point of polylactic acid A2 were as shown in Table 1. The crystallization treatment was performed at a pressure of 13.3 Pa, 110 ° C. for 2 hours, and 140 ° C. for 6 hours.
　本発明を、実施例に基づいて説明する。 The present invention will be described based on examples.
　実施例１～２１、比較例１～３
　ポリ乳酸を主体とするシート状物を形成する工程
ベント式押出機に、ポリ乳酸を２３０℃で真空ベント部を脱気しながら溶融混練した後、２００meshの金網フィルターにてポリマーを濾過させ、２３０℃に設定した先端が烏口の形状をした口金から押出し、４０℃に加熱された直径３０ｃｍのキャストドラムにエアーチャンバーを用いて密着させた後にシートを巻き取った。この時のシートの厚みは２５０μｍであった。 Examples 1-21 and Comparative Examples 1-3
Process for forming a sheet-like material mainly composed of polylactic acid After melt melting and kneading polylactic acid at 230 ° C. while degassing the vacuum vent part, the polymer is filtered with a 200 mesh wire mesh filter. The sheet was wound up after extruding from a mouthpiece with a tip set at a temperature of 0 ° C. and brought into close contact with a cast drum having a diameter of 30 cm heated to 40 ° C. using an air chamber. At this time, the thickness of the sheet was 250 μm.
　熱処理する工程
こうして得られたシートを、表２の条件で直径２０ｃｍのシリコンゴム被膜ロール４本からなる加熱ロールで加熱し、熱処理を行った。 Step of heat treatment The sheet thus obtained was heated by a heating roll comprising four silicon rubber coated rolls having a diameter of 20 cm under the conditions shown in Table 2 for heat treatment.
　延伸する工程
続いて熱処理されたシートを表２の条件で直径２０ｃｍのセラミック被膜ロールからなる予熱部と直径１２ｃｍのセラミック被膜ロールと直径１２ｃｍのシリコン被膜ロールからなるニップロールからなる延伸ロール、直径１２ｃｍのＨｃｒメッキされたロールからなる冷却部からなる延伸機に導き、延伸を行った。 Step of Stretching Subsequently, the heat-treated sheet is subjected to the conditions shown in Table 2 with a preheating portion comprising a ceramic coating roll having a diameter of 20 cm, a stretching roll comprising a nip roll comprising a ceramic coating roll having a diameter of 12 cm and a silicon coating roll having a diameter of 12 cm, and a diameter of 12 cm. It extended | stretched by guide | inducing to the drawing machine which consists of a cooling part which consists of a roll by which Hcr plating was carried out.
　得られたシートの特性は表５の通りであり、実施例においてはドローダウン量が小さく、成形性が良好であった。しかし比較例においてはドローダウン量が大きく、成形性が不良であった。 The characteristics of the obtained sheet are as shown in Table 5. In the examples, the amount of drawdown was small and the moldability was good. However, in the comparative example, the drawdown amount was large and the moldability was poor.
　実施例２２～２９
　実施例１と同様の手順により得られた熱処理前のシートを、表３の条件で長さ５ｍの第１（加熱）ゾーンと３ｍの第２（冷却）ゾーンからなるフローティング乾燥機で熱処理を行った。熱処理は第１ゾーンで行い、熱処理温度は第１ゾーンの温度であり、熱処理時間は、シートが第１ゾーンに供給されてから、排出されるまでの時間とした。続いて熱処理されたシートを表３の条件で直径２０ｃｍのセラミック被膜ロールからなる予熱部と直径１２ｃｍのセラミック被膜ロールと直径１２ｃｍのシリコン被膜ロールからなるニップロールからなる延伸ロール、直径１２ｃｍのＨｃｒメッキされたロールからなる冷却部からなる延伸機に導き、延伸を行った。得られたシートの特性は表６の通りであり、ドローダウン量が小さく、成形性が良好であった。 Examples 22-29
The sheet before heat treatment obtained by the same procedure as in Example 1 was subjected to heat treatment in a floating dryer consisting of a first (heating) zone having a length of 5 m and a second (cooling) zone having a length of 3 m under the conditions shown in Table 3. It was. The heat treatment was performed in the first zone, the heat treatment temperature was the temperature of the first zone, and the heat treatment time was the time from when the sheet was supplied to the first zone until it was discharged. Subsequently, the heat-treated sheet was subjected to a preheating portion composed of a ceramic coating roll having a diameter of 20 cm, a stretching roll composed of a nip roll composed of a ceramic coating roll having a diameter of 12 cm and a silicon coating roll having a diameter of 12 cm, and Hcr plating having a diameter of 12 cm. Then, the film was drawn into a drawing machine composed of a cooling part made of a roll. The properties of the obtained sheet are as shown in Table 6. The drawdown amount was small and the moldability was good.
　実施例３０～３５
　実施例３、５で得られた熱処理シートを、表４の条件で長さ１．５ｍの第１（予熱）ゾーンと３ｍの第２（延伸）ゾーンと１．５ｍの第３（冷却）ゾーンからなるテンター式オーブンで延伸を行った。得られたシートの特性は表６の通りであり、ドローダウン量が小さく、成形性が良好であった。 Examples 30-35
The heat-treated sheets obtained in Examples 3 and 5 were subjected to the conditions shown in Table 4 with a first (preheating) zone having a length of 1.5 m, a second (stretching) zone having 3 m, and a third (cooling) zone having 1.5 m. Stretching was performed in a tenter oven. The properties of the obtained sheet are as shown in Table 6. The drawdown amount was small and the moldability was good.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000004
Figure JPOXMLDOC01-appb-T000004
Figure JPOXMLDOC01-appb-T000005
Figure JPOXMLDOC01-appb-T000005
Figure JPOXMLDOC01-appb-T000006
Figure JPOXMLDOC01-appb-T000006

Claims (10)

  1. 　ポリ乳酸を主体とするシートであって、１６０℃における熱収縮率が０％～３０％であり、結晶化度が１％～３０％であることを特徴とする、ポリ乳酸系シート。 A polylactic acid-based sheet comprising a polylactic acid as a main component, having a heat shrinkage rate at 160 ° C. of 0% to 30% and a crystallinity of 1% to 30%.
  2. 　面配向係数ｆｎが０．１×１０－２～５×１０－２であることを特徴とする、請求項１に記載のポリ乳酸系シート。 2. The polylactic acid based sheet according to claim 1, wherein the plane orientation coefficient fn is 0.1 × 10 −2 to 5 × 10 −2 .
  3. 　ステレオ化率が８０％～１００％であることを特徴とする、請求項１または２に記載のポリ乳酸系シート。 3. The polylactic acid-based sheet according to claim 1, wherein the stereoification rate is 80% to 100%.
  4. 　前記ポリ乳酸が、ポリ－Ｌ－乳酸からなるセグメント及びポリ－Ｄ－乳酸からなるセグメントから構成されるポリ乳酸ブロック共重合体を含むことを特徴とする、請求項１～３のいずれかに記載のポリ乳酸系シート。 The polylactic acid includes a polylactic acid block copolymer composed of a segment composed of poly-L-lactic acid and a segment composed of poly-D-lactic acid. Polylactic acid based sheet.
  5. 　１６０℃における熱収縮率が５％～３０％であることを特徴とする、請求項１～４のいずれかに記載のポリ乳酸系シート。 The polylactic acid sheet according to any one of claims 1 to 4, wherein the heat shrinkage rate at 160 ° C is 5% to 30%.
  6. 　請求項１～５のいずれかに記載のポリ乳酸系シートの製造方法であって、
    　ポリ乳酸を主体とするシート状物を形成する工程、９０℃～２００℃で熱処理する工程、延伸する工程をこの順に有することを特徴とする、ポリ乳酸系シートの製造方法。     A method for producing a polylactic acid-based sheet according to any one of claims 1 to 5,
    A method for producing a polylactic acid-based sheet, comprising a step of forming a sheet-like material mainly composed of polylactic acid, a step of heat treatment at 90 to 200 ° C, and a step of stretching.
  7. 　前記熱処理する工程における加熱を、加熱ロールで行うことを特徴とする請求項６に記載のポリ乳酸系シートの製造方法。 The method for producing a polylactic acid-based sheet according to claim 6, wherein heating in the heat treatment step is performed with a heating roll.
  8. 　前記加熱ロールが、非粘着性ロールであることを特徴とする請求項７に記載のポリ乳酸系シートの製造方法。 The method for producing a polylactic acid sheet according to claim 7, wherein the heating roll is a non-adhesive roll.
  9. 　前記熱処理する工程における加熱を、フローティング乾燥機で行うことを特徴とする請求項６に記載のポリ乳酸系シートの製造方法。 The method for producing a polylactic acid-based sheet according to claim 6, wherein the heating in the heat treatment step is performed with a floating dryer.
  10. 　前記延伸する工程における延伸を、テンター式延伸機で行うことを特徴とする請求項６に記載のポリ乳酸系シートの製造方法。 The method for producing a polylactic acid sheet according to claim 6, wherein the stretching in the stretching step is performed with a tenter-type stretching machine.
PCT/JP2014/063272 2013-05-24 2014-05-20 Polylactide sheet and manufacturing method therefor WO2014189021A1 (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPWO2016186075A1 (en) * 2015-05-21 2018-03-01 三井化学東セロ株式会社 Method for producing gas barrier laminate

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2005089002A (en) * 1995-09-22 2005-04-07 Jsp Corp Container
WO2008126581A1 (en) * 2007-03-16 2008-10-23 Toray Industries, Inc. Aliphatic polyester sheet and molded body composed of the same
JP2009179773A (en) * 2008-02-01 2009-08-13 Toray Ind Inc Aliphatic polyester-based molded article
JP2011231240A (en) * 2010-04-28 2011-11-17 Teijin Ltd Resin film, decoration film consisting of it, and decorative molding
WO2012029393A1 (en) * 2010-08-31 2012-03-08 東レ株式会社 Polylactic acid block copolymer

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2005089002A (en) * 1995-09-22 2005-04-07 Jsp Corp Container
WO2008126581A1 (en) * 2007-03-16 2008-10-23 Toray Industries, Inc. Aliphatic polyester sheet and molded body composed of the same
JP2009179773A (en) * 2008-02-01 2009-08-13 Toray Ind Inc Aliphatic polyester-based molded article
JP2011231240A (en) * 2010-04-28 2011-11-17 Teijin Ltd Resin film, decoration film consisting of it, and decorative molding
WO2012029393A1 (en) * 2010-08-31 2012-03-08 東レ株式会社 Polylactic acid block copolymer

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPWO2016186075A1 (en) * 2015-05-21 2018-03-01 三井化学東セロ株式会社 Method for producing gas barrier laminate
JP7002935B2 (en) 2015-05-21 2022-01-20 三井化学東セロ株式会社 Manufacturing method of gas barrier laminate

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