WO2020262516A1 - 偏光フィルム及びその製造方法 - Google Patents

偏光フィルム及びその製造方法 Download PDF

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WO2020262516A1
WO2020262516A1 PCT/JP2020/024960 JP2020024960W WO2020262516A1 WO 2020262516 A1 WO2020262516 A1 WO 2020262516A1 JP 2020024960 W JP2020024960 W JP 2020024960W WO 2020262516 A1 WO2020262516 A1 WO 2020262516A1
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boron
acid
containing compound
polarizing film
mass
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PCT/JP2020/024960
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English (en)
French (fr)
Japanese (ja)
Inventor
亘 大橋
辻　嘉久
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株式会社クラレ
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Priority to CN202080046465.4A priority Critical patent/CN114008497A/zh
Priority to JP2021527719A priority patent/JP7451522B2/ja
Priority to KR1020227001468A priority patent/KR20220027959A/ko
Publication of WO2020262516A1 publication Critical patent/WO2020262516A1/ja

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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
    • C08J7/00—Chemical treatment or coating of shaped articles made of macromolecular substances
    • C08J7/12—Chemical modification
    • 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
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K5/00—Use of organic ingredients
    • C08K5/55—Boron-containing compounds
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L29/00—Compositions of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by an alcohol, ether, aldehydo, ketonic, acetal or ketal radical; Compositions of hydrolysed polymers of esters of unsaturated alcohols with saturated carboxylic acids; Compositions of derivatives of such polymers
    • C08L29/02—Homopolymers or copolymers of unsaturated alcohols
    • C08L29/04—Polyvinyl alcohol; Partially hydrolysed homopolymers or copolymers of esters of unsaturated alcohols with saturated carboxylic acids
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/30—Polarising elements
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/30—Polarising elements
    • G02B5/3025—Polarisers, i.e. arrangements capable of producing a definite output polarisation state from an unpolarised input state
    • G02B5/3033—Polarisers, i.e. arrangements capable of producing a definite output polarisation state from an unpolarised input state in the form of a thin sheet or foil, e.g. Polaroid

Definitions

  • the present invention relates to a polarizing film having a small shrinkage force at high temperature and excellent optical performance and moisture heat resistance, and a method for producing the same.
  • a polarizing plate having a function of transmitting and shielding light is a basic component of a liquid crystal display (LCD) together with a liquid crystal that changes the polarization state of light. Further, in recent years, a circularly polarizing plate combined with a 45 ° phase plate has been used in an organic electroluminescence display (OLED) for preventing external light reflection.
  • OLED organic electroluminescence display
  • Many polarizing plates and circular polarizing plates have a structure in which a protective film such as a cellulose triacetate (TAC) film is bonded to the surface of the polarizing film in order to prevent fading of the polarizing film or shrinkage of the polarizing film.
  • TAC cellulose triacetate
  • polyvinyl alcohol film as a polarizing film (hereinafter, “polyvinyl alcohol” and may be referred to as "PVA") was uniaxially stretched to become matrix iodine dye (I 3 - and I 5 -, etc. ) And dichromatic dyes such as bicolor dyes are adsorbed on the mainstream.
  • PVA polyvinyl alcohol film as a polarizing film
  • LCDs are widely used in small devices such as calculators and watches, smartphones, laptop computers, LCD monitors, LCD color projectors, LCD TVs, in-vehicle navigation systems, and measuring devices used indoors and outdoors.
  • OLEDs are used in smartphones.
  • OLED TVs, smart watches, etc. are widely used. These devices are required to be thin and flexible, and along with this, the LCD panel and the OLED panel are becoming thinner in recent years. As a result, the occurrence of warpage of the LCD panel and the OLED panel and the fading of the polarizing plate and the circular polarizing plate under high temperature and high humidity have become problems.
  • the main cause of warpage of LCD panels and OLED panels is that the polarizing film shrinks at high temperatures, and there is a demand for a polarizing film having a small shrinkage force at high temperatures.
  • the main factor of fading of the polarizing plate and the circular polarizing plate under high temperature and high humidity is the decomposition of the iodine complex by water.
  • Patent Document 1 a method of reducing the amount of boric acid in the PVA film and providing a step of drying the PVA film between the boric acid treatment step and the washing step.
  • Patent Document 2 A method of thinning the polarizing film and controlling the ratio of the film thickness to the draw ratio (Patent Document 2), a method of appropriately controlling the drying temperature according to the moisture content of the PVA film (Patent Document 3), and the like are known. Has been done.
  • Patent Document 3 a polarizing film having a small shrinkage force can be produced if the drying temperature is appropriately controlled according to the moisture content of the PVA film.
  • the method described in Patent Document 3 is difficult to carry out industrially because the film having a high moisture content is dried at a high temperature, so that the optical performance may be deteriorated or the polarizing film may be melted and cut during drying. Met.
  • Patent Document 4 a method of cross-linking the PVA film with polyhydric aldehyde (Patent Document 4), or stretching the PVA film in an aqueous solution in which a diboronic acid-based compound is dissolved.
  • Patent Document 5 a method of treating a PVA film with a boronic acid-based compound (Patent Document 6), a method of treating a PVA film with diboronic acid (Patent Document 7), syndiotacticity.
  • Patent Document 8 A method of obtaining a polarizing film using high PVA
  • Patent Document 9 a method of obtaining a polarizing film using PVA having a high degree of polymerization
  • Patent Document 7 The method of treating with diboronic acid described in Patent Document 7 can obtain a polarizing film having excellent moisture and heat resistance, but it is difficult to control the concentration because diboronic acid is unstable with water and decomposition proceeds, which is industrial. It was difficult to implement.
  • Patent Document 8 when PVA having high syndiotacticity is used, a polarizing film having high moisture and heat resistance can be obtained. However, since the PVA has high crystallinity, stretching at a high temperature is required, and it is industrial. It was difficult to carry out.
  • Patent Document 9 when PVA having a high degree of polymerization is used, a polarizing film having high moisture and heat resistance can be obtained, but it is difficult to achieve both low shrinkage and high moisture and heat resistance due to the high shrinkage. It was.
  • the present invention has been made to solve the above problems, and an object of the present invention is to provide a polarizing film having a small shrinkage force at high temperature and excellent moisture and heat resistance.
  • the above-mentioned problem is at least one boron-containing compound (B) selected from the group consisting of PVA (A), a monoboronic acid represented by the following formula (I), and a compound capable of converting to the monobolonic acid in the presence of water. ), And a polarizing film containing at least one boron-containing compound (C) selected from the group consisting of a diboronic acid represented by the following formula (II) and a compound capable of converting to the diboronic acid in the presence of water.
  • the mass ratio (B / C) of the boron element derived from the boron-containing compound (B) to the boron element derived from the boron-containing compound (C) is 4.0 to 8.0, and is derived from the boron-containing compound (C). This is solved by providing a polarizing film having a boron element content of 0.05 to 0.3 parts by mass with respect to 100 parts by mass of the polyvinyl alcohol (A).
  • R 1 is a monovalent aliphatic group having 1 to 20 carbon atoms, and R 1 and a boronic acid group are connected by a boron-carbon bond.
  • R 2 is a divalent aliphatic group having 1 to 20 carbon atoms, and R 2 and a boronic acid group are connected by a boron-carbon bond.
  • R 1 and R 2 are saturated aliphatic groups. It is also preferable that R 1 and R 2 are aliphatic hydrocarbon groups. It is preferable that R 1 has 2 to 5 carbon atoms, and it is also preferable that R 2 has 3 to 5 carbon atoms.
  • the above problem is to immerse the film in an aqueous solution containing a boron-containing compound (B) in a method for producing a polarizing film, which includes a dyeing treatment for dyeing a PVA film with a dichroic dye and a stretching treatment for uniaxially stretching the film. It is also solved by providing a method for producing the polarizing film, which comprises a treatment and a treatment of immersing in an aqueous solution containing the boron-containing compound (C).
  • the boron element content derived from the boron compound (B) in the PVA film after being immersed in an aqueous solution containing the boron-containing compound (B) is 1 with respect to 100 parts by mass of PVA (A). More preferably, it is 3 parts by mass or less.
  • the polarizing film of the present invention has a small shrinkage force at high temperatures and is also excellent in moisture and heat resistance. Therefore, by using the polarizing film of the present invention, it is possible to obtain an LCD panel or an OLED panel which is hard to warp at a high temperature and has excellent moisture and heat resistance. Further, according to the production method of the present invention, such a polarizing film can be produced.
  • Example 6 is a 1 H-NMR chart of the polarizing film obtained in Example 1.
  • the contraction force is plotted on the horizontal axis and the attenuation coefficient of the PVA-iodine complex is plotted on the vertical axis.
  • the polarizing film of the present invention contains at least one boron selected from the group consisting of PVA (A), a monoboronic acid represented by the following formula (I), and a compound capable of converting to the monoboronic acid in the presence of water.
  • the mass ratio (B / C) of the boron element derived from the boron-containing compound (B) to the boron element derived from the boron-containing compound (C) is 4.0 to 8.0, and the boron-containing compound (C).
  • Derived boron element content is 0.05 to 0.3 parts by mass with respect to 100 parts by mass of PVA (A).
  • the polarizing film of the present invention has a small shrinkage force and is also excellent in moisture and heat resistance. Such an effect is that the boron-containing compound (B) required for reducing the shrinkage force is adsorbed on the PVA film, and the PVA (A) has an appropriate ratio of the boron-containing compound (B) and the boron-containing compound (C). It is thought that it is played by being bridged by.
  • Monoboronic acid is a compound represented by the above formula (I) and has one boronic acid group [-B (OH) 2 ] in one molecule.
  • R 1 of the formula (I) is a monovalent aliphatic group having 1 to 20 carbon atoms.
  • the boronic acid group, the boron atom to which two hydroxyl groups are bonded have a structure bonded to a carbon atom in the compound represented by the formula (I), R 1 and boronic acid group and boron - It is connected by a carbon bond.
  • boric acid [B (OH) 3 ] the boron atom is bonded to three hydroxyl groups, whereas the boronic acid group is different in that it has a boron-carbon bond.
  • the boron-carbon bond of the boronic acid group is not hydrolyzed, it is stable even in an environment where water is present.
  • Typical examples of the boron-containing group that can be converted to a boronic acid group in the presence of water include, but are not limited to, a boronic acid ester group described later.
  • Diboronic acid is a compound represented by the above formula (II) and has two boronic acid groups [-B (OH) 2 ] in one molecule.
  • R 2 in the formula (II) is a divalent aliphatic group having 1 to 20 carbon atoms, and R 2 and a boronic acid group are connected by a boron-carbon bond.
  • the hydroxyl groups in the boronic acid group contained in monoboronic acid and diboronic acid can form an ester with alcohol in the same manner as the hydroxyl groups in boric acid.
  • the following formula (III) is an example of a boronic acid monoester group in which one molecule of alcohol (R-OH) is reacted with boronic acid.
  • R in the following formula (III) is a PVA chain, and a carbon-containing group is bonded to the PVA chain via a boron atom.
  • the following structural formula (IV) is an example of a boronic acid diester group in which two molecules of alcohol (R-OH) have reacted with a boronic acid group.
  • R-OH a boronic acid diester group
  • both of the two Rs in the structural formula (IV) are PVA chains.
  • Monobolonic acid has two hydroxyl groups capable of reacting with the hydroxyl groups of PVA to form an ester, and the PVA chain is appropriately crosslinked. Since this cross-linking is heat-stable, the shrinkage force of the polarizing film at high temperature is reduced. As a result, warpage of the LCD panel or OLED panel using the polarizing film under high temperature is suppressed. Further, it is considered that the decrease in the motility of the PVA chain due to the introduction of the ring structure into the PVA chain by the intramolecular cross-linking also contributes to the decrease in the contractile force of the polarizing film.
  • Diboronic acid has four hydroxyl groups capable of reacting with the hydroxyl groups of PVA to form an ester, and the PVA chain is strongly crosslinked. Since this cross-linking is heat-stable, the shrinkage force of the polarizing film at high temperature is reduced. As a result, warpage of the LCD panel or OLED panel using the polarizing film under high temperature is suppressed. Further, it is considered that the strong cross-linking of the PVA chain reduces the motility of the PVA chain under high temperature and high humidity, so that the moisture and heat resistance of the polarizing film is improved.
  • R 1 is a monovalent aliphatic group having 1 to 20 carbon atoms.
  • R 1 has an appropriate length, the solubility of the boron-containing compound (B) in water and the reactivity of PVA (A) with the hydroxyl group can be controlled.
  • the carbon number of R 1 is preferably 10 or less, more preferably 6 or less, and further preferably 5 or less.
  • the carbon number of R 1 is preferably 2 or more, and more preferably 3 or more.
  • R 1 is a monovalent aliphatic group, and it is sufficient that R 1 and a boronic acid group are connected by a boron-carbon bond.
  • R 1 may be a saturated aliphatic group or an unsaturated aliphatic group, but the former is preferable. Since R 1 is a saturated aliphatic group, coloring of the obtained polarizing film is suppressed and durability is improved. Further, since R 1 is a saturated aliphatic group, the orientation of the dichroic dye is improved and the optical performance is further improved.
  • the unsaturated aliphatic group is a carbon-carbon double bond, a carbon-carbon triple bond, a carbon-oxygen double bond, a carbon-nitrogen double bond, a nitrogen-nitrogen double bond, a carbon-sulfur double bond, etc. It is an aliphatic group having a structure including a double bond having a bond order of 2 or more, and a saturated aliphatic group is an aliphatic group having only a single bond structure.
  • the Monoboron acid R 1 is a saturated aliphatic group, methyl boronic acid, ethylboronic acid, propyl acid, butyl boronic acid, Penchiruboron acid, hexyl acid, to Puchiruboron acid, octyl boronic acid, Noniruboron acid, Dekaniruboron acid, undecyl Decanylboronic acid, dodecanylboronic acid, tridecanylboronic acid, tetradecanylboronic acid, pentadecanylboronic acid, hexadecanylboronic acid, heptadecanylboronic acid, octadecanylboronic acid, nonadecanylboronic acid Acids, icosanylboronic acid and their isomers, cyclopropylboronic acid, cyclobutylboronic acid, cyclopentylboronic acid, cyclohexylboronic acid, cyclohept
  • R 1 may be an aliphatic hydrocarbon group or may contain heteroatoms such as oxygen, nitrogen, sulfur and halogen. Considering availability, it is preferable that R 1 is an aliphatic hydrocarbon group containing no heteroatom.
  • the aliphatic hydrocarbon group is preferably a straight chain aliphatic hydrocarbon group having no branch.
  • boronic acid R 1 is an aliphatic hydrocarbon group, methyl boronic acid, ethylboronic acid, propyl acid, butyl boronic acid, Penchiruboron acid, hexyl acid, to Puchiruboron acid, octyl boronic acid, Noniruboron Acids, decanylboronic acid, undecanylboronic acid, dodecanylboronic acid, tridecanylboronic acid, tetradecanylboronic acid, pentadecanylboronic acid, hexadecanylboronic acid, heptadecanylboronic acid, octadecanylboronic acid Acids, nonadecanylboronic acid, icosanylboronic acid and their isomers, cyclopropylboronic acid, cyclobutylboronic acid, cyclopentylboronic acid, cyclohexylboronic acid, cyclo
  • R 1 is preferably an alkyl group, and an alkyl group represented by the following formula (V) is more preferable.
  • n is 1 to 20. n is preferably 10 or less, more preferably 6 or less, and even more preferably 5 or less. On the other hand, n is preferably 2 or more, and more preferably 3 or more.
  • R 1 is a saturated aliphatic hydrocarbon group having 2 to 5 carbon atoms from the viewpoint of obtaining a polarizing film having a smaller shrinkage force at high temperature and excellent optical performance. If the number of carbon atoms is less than 2, the stability of the bond between PVA (A) and the boron-containing compound (B) is lowered, so that the effect of lowering the shrinkage force and the effect of improving the optical performance may be insufficient. is there. If the number of carbon atoms is larger than 5, the boron-containing compound (B) is unevenly distributed on the surface of the polarizing film, so that the effect of reducing the shrinkage force and the effect of improving the optical performance may be insufficient.
  • monoboronic acid represented by the above formula (I) examples include methylboronic acid, ethylboronic acid, propylboronic acid, butylboronic acid, pentylboronic acid, hexylboronic acid, heptylboronic acid, octylboronic acid, and nonylboronic acid.
  • Propylboronic acid, butylboronic acid and pentylboronic acid are particularly preferable because they have good adsorptivity to PVA films and are highly effective in improving optical performance.
  • examples of the compound that can be converted into monoboronic acid represented by the above formula (I) in the presence of water include salts of the monoboronic acid, monoboronic acid esters, and the like.
  • R 2 is a divalent aliphatic group having 1 to 20 carbon atoms.
  • R 2 has an appropriate length, the solubility of the boron-containing compound (C) in water and the reactivity of PVA (A) with the hydroxyl group can be controlled.
  • the number of carbon atoms in R 2 is preferably 10 or less, more preferably 8 or less, still more preferably 6 or less, and particularly preferably 5 or less.
  • the carbon number of R 2 is preferably 3 or more, and more preferably 4 or more.
  • R 2 is a divalent aliphatic group, and it is sufficient that R 2 and a boronic acid group are connected by a boron-carbon bond.
  • R 2 may be a saturated aliphatic group or an unsaturated aliphatic group, but the former is preferable. Since R 2 is a saturated aliphatic group, coloring of the obtained polarizing film is suppressed. Further, it is considered that since R 2 is a saturated aliphatic group, the diffusibility of the boron-containing compound (C) into the polarizing film is improved, and the effect of improving the moist heat resistance and the effect of reducing the shrinkage force are further enhanced. Be done.
  • R 2 may be an aliphatic hydrocarbon group or may contain heteroatoms such as oxygen, nitrogen, sulfur and halogen. Considering availability, it is preferable that R 2 is an aliphatic hydrocarbon group containing no heteroatom.
  • the aliphatic hydrocarbon group is preferably a straight chain aliphatic hydrocarbon group having no branch.
  • R 2 is preferably an alkylene group, and more preferably an alkylene group represented by the following formula (VI).
  • n is 1 to 20. n is preferably 10 or less, more preferably 8 or less, further preferably 6 or less, and particularly preferably 5 or less. On the other hand, n is preferably 3 or more, and more preferably 4 or more.
  • R 2 is a saturated aliphatic hydrocarbon group having 3 to 5 carbon atoms.
  • the number of carbon atoms is less than 3, the cross-linking efficiency between the PVA chains by the boron-containing compound (C) is lowered, so that the effect of improving the moist heat resistance may be insufficient.
  • the number of carbon atoms is larger than 5, the effect of improving the moist heat resistance may be insufficient because the boron-containing compound (C) is unevenly distributed on the surface of the polarizing film. Further, since the water solubility of the boron-containing compound (C) is also lowered, the boron-containing compound (C) is likely to be precipitated on the surface of the polarizing film.
  • diboronic acid represented by the above formula (II) examples include methanediboronic acid, ethanediboronic acid, propandiboronic acid, butanediboronic acid, pentandiboronic acid, hexanediboronic acid, heptandiboronic acid, and octanediboronic acid.
  • Propaneboronic acid, butandiboronic acid, and pentaneboronic acid are particularly preferable because they have good adsorptivity to the polarizing film and are highly effective in improving moist heat resistance.
  • examples of the compound that can be converted to diboronic acid represented by the above formula (II) in the presence of water include salts of the diboronic acid and diboronic acid esters.
  • the mass ratio (B / C) of the boron element derived from the boron-containing compound (B) to the boron element derived from the boron-containing compound (C) in the polarizing film of the present invention needs to be 4.0 to 8.0. ..
  • a polarizing film having excellent shrinkage force and moisture heat resistance can be obtained.
  • the mass ratio (B / C) is out of the above range and either the boron-containing compound (B) or the boron-containing compound (C) is excessively adsorbed on the PVA film, the excessively adsorbed boron-containing compound is the other.
  • the mass ratio (B / C) is preferably 5 or more. On the other hand, the mass ratio (B / C) is preferably 7 or less, more preferably 6.5 or less.
  • the content of the boron element derived from the boron-containing compound (C) in the polarizing film is 0.05 to 0.3 parts by mass or less with respect to 100 parts by mass of PVA (A).
  • the boron element content is preferably 0.07 parts by mass or more, more preferably 0.08 parts by mass or more.
  • productivity may decrease due to the need for long processing time and high temperature processing.
  • the boron element content is preferably 0.2 parts by mass or less.
  • the boron element content derived from the boron-containing compound (B) and the boron-containing compound (C) in the polarizing film can be obtained by 1 H-NMR measurement.
  • the boron element content derived from the boron-containing compound (B) in the polarizing film is appropriately determined by the mass ratio (B / C) and the boron element content derived from the boron-containing compound (C) described above, and is not particularly limited. It is preferably 0.1 to 2.0 parts by mass with respect to 100 parts by mass of PVA (A). If the boron element content is less than 0.1 parts by mass, the reduction in shrinkage force may be insufficient. The boron element content is more preferably 0.4 parts by mass or more. On the other hand, when the boron element content exceeds 2.0 parts by mass, the effect of the boron-containing compound (C) may be hindered and the moist heat resistance may be insufficient. The boron element content is more preferably 1.6 parts by mass or less, and further preferably 1.4 parts by mass or less.
  • the polarizing film of the present invention may further contain boric acid. This may improve the optical performance.
  • the total boron element content in the polarizing film is preferably 0.2% by mass or more.
  • the total boron element content refers to the boron element derived from the boron-containing compound (B) and the boron-containing compound (C), the boron element derived from boric acid, and the boron-containing compound (B) contained in the polarizing film. It is the total amount of the boron element derived from the boron-containing compound (C) and the boron-containing compound other than boric acid.
  • the total boron element content in the polarizing film is usually 5.5% by mass or less, preferably 5.0% by mass or less, more preferably 4.5% by mass or less, and even more preferably. It is 4.0% by mass or less.
  • the total boron element content in the polarizing film can be determined by ICP emission spectrometry or the like.
  • the degree of polymerization of PVA (A) contained in the polarizing film of the present invention is preferably in the range of 1,500 to 6,000, more preferably in the range of 1,800 to 5,000. It is more preferably in the range of 2,000 to 4,000.
  • the degree of polymerization of PVA (A) in the present specification means the average degree of polymerization measured according to the description of JIS K6726-1994.
  • the degree of saponification of PVA (A) contained in the polarizing film of the present invention is preferably 95 mol% or more, preferably 96 mol% or more, from the viewpoint of water resistance of the polarizing film obtained by uniaxially stretching the film. More preferably, it is more preferably 98 mol% or more.
  • a degree of saponification of PVA herein, PVA having a vinyl alcohol unit by saponification (-CH 2 -CH (OH) -) vinyl the converted may structural units (typically vinyl ester units) and The ratio (mol%) of the number of moles of the vinyl alcohol unit to the total number of moles with the alcohol unit.
  • the saponification degree can be measured according to the description of JIS K6726-1994.
  • the method for producing PVA (A) used in the present invention is not particularly limited.
  • a method of converting the vinyl ester unit of the polyvinyl ester obtained by polymerizing the vinyl ester monomer into the vinyl alcohol unit can be mentioned.
  • the vinyl ester monomer used in the production of PVA (A) is not particularly limited, and for example, vinyl formate, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl isobutyrate, vinyl pivalate, vinyl versatic acid, vinyl caproate, etc. , Vinyl caprylate, vinyl caproate, vinyl laurate, vinyl palmitate, vinyl stearate, vinyl oleate, vinyl benzoate and the like. Vinyl acetate is preferable from an economic point of view.
  • the vinyl ester unit of the vinyl ester copolymer obtained by copolymerizing the vinyl ester monomer and another monomer copolymerizable therewith is a vinyl alcohol unit. It may be converted to.
  • ⁇ -olefins having 2 to 30 carbon atoms such as ethylene, propylene, 1-butene, and isobutene; (meth) acrylic acid or a salt thereof; Methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, i-propyl (meth) acrylate, n-butyl (meth) acrylate, i-butyl (meth) acrylate, (Meta) acrylates such as t-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, dodecyl (meth) acrylate, octadecyl (meth) acrylate; (meth) acrylamide, N-methyl (Meta) acrylamide, N-ethyl (meth) acrylamide, N
  • the vinyl ester copolymer described above can have a structural unit derived from one or more of the other monomers described above.
  • the other monomer may be present in the reaction vessel in advance when the vinyl ester monomer is subjected to the polymerization reaction, or it may be added to the reaction vessel during the polymerization reaction. It can be used by doing so.
  • the content of units derived from other monomers is preferably 10 mol% or less, preferably 5 mol% or less, based on the number of moles of all structural units constituting PVA (A). It is more preferably% or less, and further preferably 2 mol% or less.
  • the film can be stretched at a higher temperature, the occurrence of troubles such as stretch breakage is reduced, and the productivity of the polarizing film is further improved, the copolymerization with the above vinyl ester monomer is carried out.
  • Ethylene is preferred as a possible monomer.
  • PVA (A) contains ethylene units
  • the content of ethylene units is based on the number of moles of all structural units constituting PVA (A) from the viewpoint of stretchability and stretchable temperature as described above. 1 to 10 mol% is preferable, and 2 to 6 mol% is more preferable.
  • the PVA film used for producing the polarizing film of the present invention may contain a plasticizer in addition to the above PVA (A).
  • Preferred plasticizers include polyhydric alcohols, and specific examples include ethylene glycol, glycerin, propylene glycol, diethylene glycol, diglycerin, triethylene glycol, tetraethylene glycol, trimethylolpropane and the like. Furthermore, one or more of these plasticizers can be included. Among these, glycerin is preferable from the viewpoint of improving stretchability.
  • the content of the plasticizer in the PVA film used for producing the polarizing film of the present invention is preferably in the range of 1 to 20 parts by mass with respect to 100 parts by mass of PVA (A), and is preferably 3 to 17 parts by mass. It is more preferably in the range of 5 to 15 parts by mass, and further preferably in the range of 5 to 15 parts by mass.
  • the content is 1 part by mass or more, the stretchability of the film is improved.
  • the content is 20 parts by mass or less, it is possible to prevent the film from becoming too flexible and the handleability from being lowered.
  • the PVA film used in the production of the polarizing film of the present invention further includes a filler, a processing stabilizer such as a copper compound, a weather resistance stabilizer, a colorant, an ultraviolet absorber, a light stabilizer, an antioxidant, and an antistatic agent.
  • a processing stabilizer such as a copper compound, a weather resistance stabilizer, a colorant, an ultraviolet absorber, a light stabilizer, an antioxidant, and an antistatic agent.
  • Additives other than PVA (A) and the plasticizer, such as a retarder can be added as needed.
  • the content of the other additive in the PVA film is usually 10% by mass or less, preferably 5% by mass or less.
  • the degree of swelling of the PVA film used in the production of the polarizing film of the present invention is preferably in the range of 160 to 240%, more preferably in the range of 170 to 230%, and in the range of 180 to 220%. It is particularly preferable to be inside.
  • the degree of swelling is 160% or more, it is possible to suppress the extremely progress of crystallization, and it is possible to stably stretch to a high magnification.
  • the degree of swelling is 240% or less, dissolution during stretching is suppressed, and stretching can be performed even under higher temperature conditions.
  • the thickness of the PVA film used for producing the polarizing film of the present invention is not particularly limited, but is generally 1 to 100 ⁇ m, preferably 5 to 60 ⁇ m, and particularly preferably 10 to 45 ⁇ m. If the PVA film is too thin, stretch breakage tends to occur easily during the uniaxial stretching process for producing a polarizing film. Further, if the PVA film is too thick, stretching spots tend to occur during the uniaxial stretching process for producing the polarizing film, and the shrinkage force of the produced polarizing film tends to increase.
  • the width of the PVA film used for producing the polarizing film of the present invention is not particularly limited, and can be determined according to the intended use of the polarizing film to be produced. In recent years, since the screen size of liquid crystal televisions and liquid crystal monitors has been increasing, it is suitable for these applications if the width of the PVA film used for manufacturing the polarizing film is 3 m or more. On the other hand, if the width of the PVA film used for producing the polarizing film is too large, it tends to be difficult to uniformly perform uniaxial stretching when producing the polarizing film with a practical device, so that the polarizing film is produced.
  • the width of the PVA film used in the above is preferably 10 m or less.
  • the production method of the PVA film used for producing the polarizing film of the present invention is not particularly limited, and a production method in which the thickness and width of the film after film formation are uniform is preferably adopted.
  • a film-forming stock solution in which one or more of PVA (A) and, if necessary, the plasticizer, the other additive, and a surfactant described later are dissolved in a liquid medium.
  • PVA (A) and if necessary, one or more of plasticizers, other additives, surfactants, liquid media, etc., and PVA (A) melts. It can be manufactured using the existing film-forming stock solution.
  • the film-forming stock solution contains at least one of a plasticizer, other additives, and a surfactant, it is preferable that these components are uniformly mixed.
  • liquid medium used for preparing the film-forming stock solution examples include water, dimethyl sulfoxide, dimethylformamide, dimethylacetamide, N-methylpyrrolidone, ethylene glycol, glycerin, propylene glycol, diethylene glycol, triethylene glycol, and tetraethylene glycol. , Trimethylolpropane, ethylenediamine, diethylenetriamine and the like, and one or more of these can be used. Of these, water is preferable from the viewpoint of environmental load and recoverability.
  • the volatile content of the membrane-forming stock solution (the content ratio of volatile components such as liquid media removed by volatilization or evaporation during membrane-forming in the membrane-forming stock solution) varies depending on the membrane-forming method, membrane-forming conditions, etc., but is generally used. Specifically, it is preferably in the range of 50 to 95% by mass, and more preferably in the range of 55 to 90% by mass.
  • the volatile content of the membrane-forming stock solution is 50% by mass or more, the viscosity of the membrane-forming stock solution does not become too high, filtration and defoaming during preparation of the membrane-forming stock solution are smoothly performed, and a film with few foreign substances and defects. Is easy to manufacture.
  • the volatile fraction of the film-forming stock solution is 95% by mass or less, the concentration of the film-forming stock solution does not become too low, and industrial film production becomes easy.
  • the membrane-forming stock solution preferably contains a surfactant.
  • a surfactant By containing the surfactant, the film-forming property is improved, the occurrence of thickness unevenness of the film is suppressed, and the film can be easily peeled off from the metal roll or belt used for the film-forming.
  • the film When a PVA film is produced from a film-forming stock solution containing a surfactant, the film may contain a surfactant.
  • the type of the above-mentioned surfactant is not particularly limited, but an anionic surfactant or a nonionic surfactant is preferable from the viewpoint of peelability from a metal roll or a belt.
  • anionic surfactant examples include carboxylic acid types such as potassium laurate; polyoxyethylene lauryl ether sulfate, sodium alkyl sulfate, potassium alkyl sulfate, ammonium alkyl sulfate, triethanolamine alkyl sulfate, and polyoxyethylene alkyl ether sulfate.
  • carboxylic acid types such as potassium laurate; polyoxyethylene lauryl ether sulfate, sodium alkyl sulfate, potassium alkyl sulfate, ammonium alkyl sulfate, triethanolamine alkyl sulfate, and polyoxyethylene alkyl ether sulfate.
  • Sulfate types such as sodium, polyoxypropylene alkyl ether sulfate sodium, polyoxyethylene alkylphenyl ether sulfate sodium, octyl sulfate, etc .
  • sodium alkyl sulfonate, potassium alkyl sulfonate, ammonium alkyl sulfonate, triethanolamine alkyl sulfonate, alkyl benzene Sulfonic acid types such as sodium sulfonate, disodium dodecyldiphenyl ether disulfonate, sodium alkylnaphthalene sulfonate, disodium alkylsulfosuccinate, disodium polyoxyethylene alkylsulfosuccinate, dodecylbenzenesulfonate, etc .
  • nonionic surfactant examples include an alkyl ether type such as polyoxyethylene oleyl ether; an alkylphenyl ether type such as polyoxyethylene octylphenyl ether; an alkyl ester type such as polyoxyethylene laurate; and polyoxyethylene laurylamino.
  • Alkylamine type such as ether
  • Alkylamide type such as polyoxyethylene lauric acid amide
  • Polypropylene glycol ether type such as polyoxyethylene polyoxypropylene ether
  • Alkanolamide type such as lauric acid diethanolamide and oleic acid diethanolamide
  • Polyoxy An allylphenyl ether type such as alkylene allylphenyl ether is suitable.
  • surfactants can be used alone or in combination of two or more.
  • the content thereof is preferably in the range of 0.01 to 0.5 parts by mass with respect to 100 parts by mass of PVA (A) contained in the membrane-forming stock solution. It is more preferably in the range of 0.02 to 0.3 parts by mass, and particularly preferably in the range of 0.05 to 0.2 parts by mass.
  • the content is 0.01 parts by mass or more, the film-forming property and the peelability are further improved.
  • the content is 0.5 parts by mass or less, it is possible to prevent the surfactant from bleeding out to the surface of the PVA film and causing blocking, resulting in deterioration of handleability.
  • Examples of the method for forming a PVA film using the above-mentioned undiluted film-forming solution include a cast film-forming method, an extrusion film-forming method, a wet film-forming method, and a gel film-forming method. These film forming methods may adopt only one kind or a combination of two or more kinds. Among these film-forming methods, the cast film-forming method and the extrusion film-forming method are preferable because a PVA film having a uniform thickness and width and good physical characteristics can be obtained. The formed PVA film can be dried or heat-treated as needed.
  • a T-type slit die, a hopper plate, an I-die, a lip coater die, or the like is used to prepare the above-mentioned film-forming stock solution.
  • the volatile components are evaporated from one surface to dry and then further dried on the peripheral surface of one or more rotating heated rolls placed downstream thereof, or in a hot air drying device.
  • a multilayer PVA film may be formed by forming a layer made of PVA (A) on one surface of a base film made of a single resin layer.
  • a suitable production method is a method for producing a polarizing film including a dyeing treatment for dyeing a PVA film with a dichroic dye and a stretching treatment for uniaxially stretching the film, in which the film is made into an aqueous solution containing a boron-containing compound (B).
  • This is a method for producing a polarizing film, which comprises a treatment of immersing and a treatment of immersing in an aqueous solution containing a boron-containing compound (C).
  • a method of subjecting the PVA film to a dyeing treatment, a uniaxial stretching treatment, and, if necessary, a swelling treatment, a boric acid cross-linking treatment, a fixing treatment, a washing treatment, a drying treatment, a heat treatment, and the like can be mentioned.
  • the order of each treatment such as swelling treatment, dyeing treatment, boric acid cross-linking treatment, uniaxial stretching treatment, and fixing treatment is not particularly limited, and one or more treatments can be performed at the same time. It is also possible to perform one or more of each process twice or more.
  • the swelling treatment can be performed by immersing the PVA film in water.
  • the temperature of the water for immersing the film is preferably in the range of 20 to 40 ° C, more preferably in the range of 22 to 38 ° C, and further preferably in the range of 25 to 35 ° C. ..
  • the time for immersion in water is, for example, preferably in the range of 0.1 to 5 minutes, and more preferably in the range of 0.2 to 3 minutes.
  • the water in which the film is immersed is not limited to pure water, and may be an aqueous solution in which various components are dissolved, or a mixture of water and a hydrophilic medium.
  • the dyeing process can be performed by bringing the dichroic dye into contact with the PVA film.
  • the dichroic dye an iodine dye or a dichroic dye is generally used.
  • the timing of the dyeing treatment may be any stage before the uniaxial stretching treatment, during the uniaxial stretching treatment, and after the uniaxial stretching treatment.
  • the dyeing treatment is generally performed by immersing the PVA film in a solution containing iodine-potassium iodide (particularly an aqueous solution) or a solution containing a plurality of bicolor dyes (particularly an aqueous solution) using a PVA film as a dyeing bath. is there.
  • the concentration of iodine in the dyeing bath is preferably in the range of 0.01 to 0.5% by mass, and the concentration of potassium iodide is preferably in the range of 0.01 to 10% by mass.
  • the temperature of the dyeing bath is preferably 20 to 50 ° C, particularly preferably 25 to 40 ° C.
  • a suitable staining time is 0.2-5 minutes.
  • the dichroic dye is preferably an aqueous dye.
  • the dye concentration in the dyeing bath is preferably 0.001 to 10% by mass.
  • a dyeing aid may be used, or an inorganic salt such as sodium sulfate or a surfactant may be used.
  • the dyeing temperature is preferably 30 to 80 ° C.
  • Specific dichroic dyes include C.I. Ai. Direct Yellow 28, Sea. Ai. Direct Orange 39, Sea. Ai. Direct Yellow 12, Sea. Ai. Direct Yellow 44, Sea. Ai. Direct Orange 26, Sea. Ai. Direct Orange 71, Sea. Ai. direct. Orange 107, Sea. Ai. Direct Red 2, Sea. Ai. Direct Red 31, Sea. Ai. direct. Red 79, Sea. Ai. Direct Red 81, Sea. Ai. Direct Red 247, Sea. Ai. Direct Green 80, Sea. Ai. Examples thereof include Direct Green 59, and a dichroic dye developed for manufacturing a polarizing plate is preferable.
  • the PVA film can also be subjected to boric acid cross-linking treatment.
  • the boric acid cross-linking treatment is preferably performed before the uniaxial stretching treatment.
  • the boric acid cross-linking treatment can be performed by immersing the PVA film in an aqueous solution containing a boric acid cross-linking agent.
  • the boric acid cross-linking agent one or more kinds of boron-containing inorganic compounds such as borate such as boric acid and borax can be used.
  • the concentration of the boric acid cross-linking agent in the aqueous solution containing the boric acid cross-linking agent is preferably in the range of 0.1 to 6.0% by mass.
  • the concentration of the boric acid cross-linking agent is more preferably 0.2% by mass or more. Further, it is more preferably 4.0% by mass or less.
  • the stretchability may be improved. If the concentration of the boric acid cross-linking agent is too high, it may be difficult to contain the boron-containing compound (B) or the boron-containing compound (C) in a later step, so the concentration should not be too high. Is good.
  • the aqueous solution containing the boric acid cross-linking agent may contain an auxiliary agent such as potassium iodide.
  • the temperature of the aqueous solution containing the boric acid cross-linking agent is preferably in the range of 20 to 50 ° C., particularly preferably in the range of 25 to 40 ° C.
  • the PVA film may be stretched (pre-stretched) during or between the above-mentioned treatments.
  • the total stretching ratio of the pre-stretching performed before the uniaxial stretching treatment is the raw material before stretching from the viewpoint of the optical performance of the obtained polarizing film.
  • the total draw ratio is preferably 4.0 times or less, more preferably 3.5 times or less.
  • the draw ratio in the swelling treatment is preferably 1.05 to 2.5 times.
  • the draw ratio in the dyeing treatment is preferably 1.1 to 2.5 times.
  • the draw ratio in the boric acid cross-linking treatment is preferably 1.1 to 2.5.
  • the uniaxial stretching treatment may be performed by either a wet stretching method or a dry stretching method.
  • stretching is performed in an aqueous solution. It can also be stretched in the above-mentioned dyeing bath or in an aqueous boric acid solution.
  • the uniaxial stretching treatment may be performed at room temperature, the uniaxial stretching treatment may be performed while heating, or the uniaxial stretching treatment may be performed in the air using a PVA film after water absorption. You can also do it.
  • the wet stretching method is preferable, and the uniaxial stretching treatment is more preferable in an aqueous solution containing boric acid.
  • the boric acid concentration in the boric acid aqueous solution is preferably in the range of 0.5 to 6% by mass, and more preferably in the range of 1 to 5% by mass. Further, the boric acid aqueous solution may contain potassium iodide, and the concentration thereof is preferably in the range of 0.01 to 10% by mass.
  • the stretching temperature in the uniaxial stretching treatment is preferably 30 ° C. or higher, more preferably 40 ° C. or higher, and even more preferably 50 ° C. or higher. On the other hand, the stretching temperature is preferably 90 ° C. or lower, more preferably 80 ° C. or lower, and even more preferably 70 ° C. or lower.
  • the stretching ratio in the uniaxial stretching treatment is preferably 2.0 to 4.0 times.
  • the draw ratio is more preferably 2.2 times or more.
  • the draw ratio is more preferably 3.5 times or less.
  • the total draw ratio up to the fixing treatment described later is preferably 5 times or more based on the original length of the raw material PVA film before stretching from the viewpoint of the optical performance of the obtained polarizing film. More preferably, it is 5 times or more.
  • the upper limit of the draw ratio is not particularly limited, but the draw ratio is preferably 8 times or less.
  • the direction of the uniaxial stretching treatment when the long PVA film is subjected to the uniaxial stretching treatment there is no particular limitation on the direction of the uniaxial stretching treatment when the long PVA film is subjected to the uniaxial stretching treatment, and the uniaxial stretching treatment in the long direction, the lateral uniaxial stretching treatment, the so-called diagonal stretching treatment can be adopted. Since a polarizing film having excellent optical performance can be obtained, uniaxial stretching treatment in the long direction is preferable.
  • the uniaxial stretching process in the long direction can be performed by using a stretching device including a plurality of rolls parallel to each other and changing the peripheral speed between the rolls.
  • the horizontal uniaxial stretching treatment can be performed using a tenter type stretching machine.
  • the fixing treatment bath used for the fixing treatment an aqueous solution containing a boron-containing compound (B) or a boron-containing compound (C) can be preferably used. Further, if necessary, boric acid, an iodine compound, a metal compound and the like may be further added to the fixing treatment bath.
  • the temperature of the fixing treatment bath is preferably 10 to 80 ° C.
  • the draw ratio in the fixing treatment is preferably 1.3 times or less, more preferably 1.2 times or less, and further preferably less than 1.1 times.
  • the PVA film is immersed in an aqueous solution containing a boron-containing compound (B) and an aqueous solution containing a boron-containing compound (C), whereby the boron-containing compound (B) and the boron-containing compound (B) are immersed in the film.
  • the boron-containing compound (C) is adsorbed.
  • the boron-containing compound (B) and the boron-containing compound (C) can be obtained in one step.
  • the boron-containing compound (B) and the boron-containing compound (C) can be adsorbed on the film without competing with each other, and the effect of reducing the shrinkage force and the effect of improving the heat resistance to moisture and heat are compatible. It is preferable that the treatment of immersing the film in the aqueous solution containing the boron-containing compound (B) and the treatment of immersing the film in the aqueous solution containing the boron-containing compound (C) are performed separately.
  • the content of the boron element derived from the boron-containing compound (B) in the PVA film after being immersed in the aqueous solution containing the boron-containing compound (B) and before being immersed in the aqueous solution containing the boric acid-containing compound (C) is It is preferably 1.3 parts by mass or less, and particularly preferably 1.0 part by mass or less. If the content exceeds 1.3 parts by mass, the adsorption of the boron-containing compound (C) is inhibited, and the moist heat resistance may be insufficient. On the other hand, if the content of the boron-containing compound (B) is too small, the reduction in shrinkage force becomes insufficient.
  • the boric acid-containing compound (C) The content of the boron element derived from the boron-containing compound (B) in the PVA film before being immersed in the aqueous solution containing the above is preferably 0.1 part by mass or more.
  • the concentration of the boron-containing compound (B) in the aqueous solution containing the boron-containing compound (B) is preferably 15% by mass or less.
  • concentration is higher than 15% by mass, a high-density adsorption layer of the boron-containing compound (B) is formed on the surface of the polarizing film in a short time, so that the boron-containing compound (C) is adsorbed on the polarizing film. May be hindered. Further, the boron-containing compound (B) may be unevenly distributed near the surface of the polarizing film, and as a result, the optical performance may be deteriorated.
  • the concentration is more preferably 10% by mass or less, further preferably 5.0% by mass or less, particularly preferably 3.5% by mass or less, and preferably 1.5% by mass or less. It is even more preferable, and most preferably 0.8% by mass or less.
  • the concentration of the boron-containing compound (B) is preferably 0.1% by mass or more.
  • the aqueous solution containing the boron-containing compound (B) may contain the boron-containing compound (C) as long as the effect of the present invention is not impaired, but the boron-containing compound (B) in the aqueous solution
  • the ratio (C / B) of the concentration [mass%] of the boron-containing compound (C) to the concentration [mass%] of is preferably 0.1 or less, more preferably 0.01 or less, and the boron-containing compound (C) is It is more preferable that it is not substantially contained.
  • the concentration of the boron-containing compound (C) in the aqueous solution containing the boron-containing compound (C) is preferably less than 2.0% by mass, more preferably less than 1.5% by mass, and 0.8% by mass. The following is more preferable.
  • concentration of the aqueous solution of the boron-containing compound (C) is high, the reason is unknown, but the reduction in shrinkage force may be insufficient.
  • concentration of the boron-containing compound (C) is too low, the improvement of moist heat resistance may be insufficient. Therefore, the concentration is preferably 0.1% by mass or more, preferably 0.3% by mass. % Or more is particularly preferable.
  • the aqueous solution containing the boron-containing compound (C) may contain the boron-containing compound (B) as long as the effect of the present invention is not impaired, but the boron-containing compound (C) in the aqueous solution
  • the ratio (B / C) of the concentration [mass%] of the boron-containing compound (B) to the concentration [mass%] of is preferably less than 1, more preferably 0.5 or less, further preferably 0.1 or less, and containing boron. It is more preferable that the compound (B) is substantially not contained.
  • the concentration [mass%] ratio (B / C) is 1 or more, the boron-containing compound (B) inhibits the adsorption of the boron-containing compound (C), and the effect of improving the moist heat resistance becomes insufficient. There is a risk.
  • the aqueous solution containing the boron-containing compound (B) or the boron-containing compound (C) preferably contains an iodide auxiliary such as potassium iodide from the viewpoint of optical performance, and the concentration of the iodide is 0.5 to 15. It is preferably mass%.
  • the temperature of these aqueous solutions is preferably 10 to 80 ° C. If the temperature is too low, the boron-containing compound (B) and the boron-containing compound (C) may precipitate in the treatment bath.
  • the temperature of the aqueous solution is more preferably 15 ° C. or higher, and even more preferably 20 ° C. or higher.
  • the temperature of the aqueous solution is more preferably 70 ° C. or lower, further preferably 60 ° C. or lower, and particularly preferably 50 ° C. or lower.
  • the time of immersion in the aqueous solution is preferably 5 to 400 seconds.
  • the boron-containing compound (B) and the boron-containing compound (C) may be adsorbed on the PVA film in any of the steps of dyeing treatment, boric acid cross-linking treatment, uniaxial stretching treatment, and fixing treatment, but the PVA film during the uniaxial stretching treatment. It is preferable to carry out after the uniaxial stretching treatment, and particularly preferably during the fixing treatment after the uniaxial stretching treatment, from the viewpoint of suppressing the cutting of the uniaxially stretched film and obtaining a polarizing film having particularly excellent optical performance.
  • suitable production methods include a swelling treatment, a uniaxial stretching treatment, a fixing treatment with the boron-containing compound (B), and a boron-containing compound.
  • Fixation treatment by (C) is performed in this order, swelling treatment, boric acid cross-linking treatment, uniaxial stretching treatment, fixation treatment by boron-containing compound (B), and fixation treatment by boron-containing compound (C) in this order.
  • one or more treatments selected from a cleaning treatment, a drying treatment, and a heat treatment may be further performed, if necessary.
  • the immobilization treatment is performed in such an order, the boron-containing compound (C) is firmly bonded to the hydroxyl group of the PVA film, thereby inhibiting the adsorption of the boron-containing compound (B) to the polarizing film, and as a result.
  • the optical performance may be reduced, or the contraction force may be insufficiently reduced.
  • the cleaning treatment is generally performed by immersing the film in distilled water, pure water, an aqueous solution, or the like.
  • an aqueous solution containing an iodide such as potassium iodide as an auxiliary agent, and the concentration of the iodide is preferably 0.5 to 10% by mass.
  • the temperature of the aqueous solution in the cleaning treatment is generally 5 to 50 ° C, preferably 10 to 45 ° C, and even more preferably 15 to 40 ° C. From an economic point of view, it is not preferable that the temperature of the aqueous solution is too low, and if the temperature of the aqueous solution is too high, the optical performance may deteriorate.
  • the conditions of the drying treatment are not particularly limited, but it is preferable to perform drying at a temperature within the range of 30 to 150 ° C., particularly within the range of 50 to 130 ° C. By drying at a temperature in the range of 30 to 150 ° C., a polarizing film having excellent dimensional stability can be easily obtained.
  • the heat treatment is a treatment for further heating a polarizing film having a moisture content of 5% or less after the drying treatment.
  • the conditions of the heat treatment are not particularly limited, but the heat treatment is preferably performed in the range of 60 ° C. to 150 ° C., particularly in the range of 70 ° C. to 150 ° C. If the heat treatment temperature is less than 60 ° C., the dimensional stabilization effect may be insufficient, and if it exceeds 150 ° C., the polarizing film may be severely reddish.
  • the polarizing film of the present invention thus obtained has a small shrinkage force at high temperatures and is also excellent in moisture and heat resistance.
  • the shrinkage force of the polarizing film is preferably less than 5N, more preferably 4N or less.
  • the attenuation coefficient of the PVA-iodine complex in the polarizing film is preferably ⁇ 0.5 or higher, and more preferably ⁇ 0.4 or higher.
  • the shrinkage force of the polarizing film and the attenuation coefficient of the PVA-iodine complex are measured by the methods described in Examples described later.
  • the polarizing film of the present invention is usually used as a polarizing plate by laminating a protective film that is optically transparent and has mechanical strength on both sides or one side thereof.
  • a protective film a cellulose triacetate (TAC) film, a cellulose acetate / butyrate (CAB) film, an acrylic film, a polyester film, or the like is used.
  • TAC cellulose triacetate
  • CAB cellulose acetate / butyrate
  • acrylic film a polyester film, or the like
  • examples of the adhesive for bonding include a PVA-based adhesive and a UV-curable adhesive.
  • the polarizing plate obtained as described above may be bonded to a retardation film, a viewing angle improving film, a brightness improving film, or the like. Further, after coating a polarizing plate with an adhesive such as acrylic, it can be bonded to a glass substrate and used as an LCD component.
  • the hydrogen peaks 5 of the hydrocarbon groups derived from the boron-containing compound (B) and the boron-containing compound (C), which overlap in the range of 1.0 to 1.2 ppm, are integrated, and the peak area (area B) thereof is integrated. )
  • the total area (area C) of hydrogen peaks in the range of 1.6 to 2.3 ppm was determined by regarding it as the total of hydrogen peaks 4 of the hydrocarbon group derived from (C).
  • the area (area A) of the hydrogen peak 6 of the methyl group derived from the boron-containing compound (B), which does not overlap with the hydrogen peak derived from PVA or the hydrogen peak derived from the boron-containing compound (C), is used as the reference for the peak area.
  • the number of hydrogens in the methyl group was set to 3, which is the same as the number of hydrogens.
  • the area D obtained by subtracting the area U of the hydrogen peak 4 of the boron-containing compound (B) and the hydrocarbon group derived from the boron-containing compound (C) overlapping the hydrogen peak of the methylene group derived from PVA from the area C was calculated. ..
  • the boron element content (parts by mass) derived from the boron-containing compound (B) with respect to 100 parts by mass of PVA (A) was calculated.
  • W in the following formula (1) is the number of borons per molecule of the boron-containing compound (B).
  • the following formula (1) is a formula used when unmodified PVA is used, and when the modified PVA is used as a raw material, the following formula (1) needs to be appropriately modified.
  • Boron element content (parts by mass) derived from boron-containing compound (B) with respect to 100 parts by mass of PVA (A) ⁇ (Area A / 3) / (Area D / 2) ⁇ ⁇ (10.811 ⁇ W / 44.0526) ⁇ 100 (1)
  • X of the following formula (2) overlaps with the hydrogen peak of the hydrocarbon group derived from the boron-containing compound (C) in the range of 1.0 to 1.2 ppm, and hydrogen of the hydrocarbon group derived from the boron-containing compound (B). It is a number, and Y is the number of hydrogens per molecule of the hydrocarbon group derived from the boron-containing compound (C) in the range of 1.0 ppm to 1.2 ppm. Further, Z is the number of borons per molecule of the boron-containing compound (C).
  • the following formula (2) is a formula used when unmodified PVA is used, and when the modified PVA is used as a raw material, the following formula (2) needs to be appropriately modified.
  • Boron element content (parts by mass) derived from boron-containing compound (C) with respect to 100 parts by mass of PVA (A) ⁇ (Area A / 3) / (Area D / 2) ⁇ ⁇ ⁇ (Area B) -X ⁇ / Y ⁇ (10.811 ⁇ Z / 44.0526) ⁇ 100 (2)
  • 10.811 is the atomic weight of boron
  • 44.0526 is the molecular weight per mole of unmodified PVA repeating unit.
  • the 1 H-NMR chart in FIG. 1 is a measurement of the polarizing film of Example 1.
  • the sum of the hydrogen peak areas of the boron-containing compound (B) that does not overlap with the hydrogen peak derived from PVA or the hydrocarbon group derived from the boron-containing compound (C) (area F) is used as the reference for the peak area.
  • the value of the hydrogen number and the area F of the corresponding hydrocarbon group of the boron-containing compound (B) or the boron-containing compound (C) were set to be the same.
  • the hydrogen peak in the range of 1.6 ppm to 2.3 ppm is overlapped with the hydrogen peak derived from the methylene group of PVA and the hydrogen peak derived from the methylene group of PVA.
  • the boron-containing compound (B) or the boron-containing compound (C) The peak area (area G) was determined by regarding the total hydrogen peaks of the hydrocarbon groups contained in C). Then, the area H was calculated by subtracting the number of hydrogens of the boron-containing compound (B) or the hydrocarbon group derived from the boron-containing compound (C) overlapping with the hydrogen peak of the methylene group derived from PVA from the area G. Substituting the values obtained by these methods into the following formula (3), the boron element content (parts by mass) derived from the boron-containing compound (B) or the boron-containing compound (C) with respect to 100 parts by mass of PVA (A) can be obtained. Calculated.
  • S is the number of hydrogens of the hydrocarbon group contained in the boron-containing compound (B) or the boron-containing compound (C) that does not overlap with the peak of PVA
  • T is the boron-containing compound (B).
  • it is the number of borons per molecule of the boron-containing compound (C).
  • the formula (3) is a formula used when unmodified PVA is used, and when the modified PVA is used as a raw material, it is necessary to appropriately modify the formula (3).
  • 10.811 is the atomic weight of boron
  • 44.0526 is the molecular weight per mole of unmodified PVA repeating unit.
  • Optical performance of polarizing film (1) Measurement of Luminosity-Corrected Single Transmittance Ts
  • the visual sensitivity-corrected single-transmittance Ts of the polarizing film obtained in the following Example or Comparative Example (hereinafter, “luminosity-corrected single-transmittance Ts” is referred to as “transmittance Ts” (Sometimes referred to as) is an automatic polarizing film measuring device VAP-7070S (manufactured by Nihon Kogaku Co., Ltd.) equipped with a spectrophotometer with an integrating sphere (“V-7100” manufactured by Nippon Spectral Co., Ltd.) and a Grantera polarizer. Measured using.
  • the "MD transmittance” indicates the transmittance (%) when the direction of polarized light emitted from the Grantera polarizer and the transmission axis of the polarizing film sample are parallel to each other.
  • the "TD transmittance" indicates the transmittance (%) when the direction of polarized light emitted from the Grantera polarizer and the transmission axis of the polarizing film sample are orthogonal to each other.
  • the transmittance Ts is calculated from the MD transmittance and the TD transmittance by applying a sensitivity correction called luminosity factor correction.
  • the polarizing film was pulled at a speed of 1 mm / min, the tension was stopped when the tension reached 2N, and the tension was measured up to 4 hours later in that state.
  • a marked line sticker is attached to the chuck, and the distance between the chucks is increased by the amount of movement of the marked line sticker attached to the chuck using the video type extensometer "TR ViewX120S".
  • the measurement was performed while correcting so that was constant.
  • the minimum value of tension occurs at the initial stage of measurement (within 10 minutes from the start of measurement)
  • the minimum value of tension is subtracted from the measured value of tension after 4 hours, and the difference is taken as the shrinkage force of the polarizing film.
  • the minimum value obtained by subtracting 2N which is the tension when the tension was stopped, from the measured value of the tension after 4 hours was taken as the shrinkage force of the polarizing film.
  • the orthogonal transmittance (%) at 610 nm in time) was measured.
  • the orthogonal transmittance (%) is a value calculated from the following formula (5).
  • the orthogonal absorbance A 0 of 610 nm at the initial stage (0 hours) was calculated.
  • the evaluation sample was allowed to stand for 1 hour in an atmosphere of 60 ° C./90% RH, left for 2 hours, and then for 4 hours.
  • each standing is performed.
  • Orthogonal absorbance A over time was calculated.
  • the orthogonal transmittance was measured using the same evaluation sample until 8 hours later.
  • the relationship between the test time and Ln (A / A 0 ) was illustrated using Microsoft Excel, and the slope was obtained by approximating it as a linear equation passing through the origin. This slope was used as the attenuation coefficient of the PVA-iodine complex, and was used as an index of fading (an index of moisture and heat resistance) in the present invention.
  • Orthogonal transmittance (%) of 610 nm at each standing time (MD transmittance at 610 nm at each standing time ⁇ TD transmittance at 610 nm at each standing time) / 100 (5)
  • Absorbance A at each standing time 2-Log (Orthogonal transmittance at 610 nm at each standing time) (6)
  • Example 1 Contains 100 parts by mass of PVA (saponification degree 99.9 mol%, polymerization degree 2400), 10 parts by mass of glycerin as a plasticizer, and 0.1 parts by mass of polyoxyethylene lauryl ether sodium sulfate as a surfactant, and the content of PVA.
  • PVA response degree 99.9 mol%, polymerization degree 2400
  • glycerin as a plasticizer
  • polyoxyethylene lauryl ether sodium sulfate as a surfactant
  • a sample having a width of 5 cm and a length of 9 cm was cut from the central portion of the PVA film thus obtained in the width direction so that a range of 5 cm in width ⁇ 5 cm in length could be uniaxially stretched.
  • This sample was uniaxially stretched 1.1 times in the length direction while being immersed in pure water at 30 ° C. for 30 seconds for swelling treatment. Subsequently, it was immersed in an aqueous solution (dyeing treatment bath) (temperature 30 ° C.) containing 0.043% by mass of iodine and 4.3% by mass of potassium iodide (KI) for 60 seconds while being immersed 2.2 times (2.4 in total). Iodine was adsorbed by uniaxially stretching in the length direction.
  • first fixation treatment bath temperature 30 ° C.
  • second fixing treatment bath temperature 50 ° C.
  • the hydrogen peak 3 of the methylene group of PVA overlapped with the hydrogen peak 4 of the hydrocarbon group derived from n-propylboronic acid and 1,4-butanjiboronic acid, so that the hydrogen peak in the range of 1.6 to 2.3 ppm was generated.
  • the content of the boron element derived from the boron-containing compound (C) was 0.08 parts by mass with respect to 100 parts by mass of PVA (A).
  • the total boron element content in the polarizing film was measured and found to be 1.9% by mass.
  • the boron element content derived from the boron-containing compound (B) of the stretched film obtained by drying the PVA film at 60 ° C. for 4 minutes after the completion of the first fixing treatment was measured and found to be 0.81 parts by mass. This result is also shown in Table 1.
  • Example 2 The same as in Example 1 except that an aqueous solution (temperature 30 ° C.) containing 0.5% by mass of 1,4-butandiboronic acid and 5.5% by mass of potassium iodide was used in the second fixing treatment bath. A polarizing film was prepared, and each measurement and each evaluation were performed by the above method. The results are shown in Table 1 and FIG.
  • Example 1 A polarizing film was produced in the same manner as in Example 1 except that the second fixing treatment was not performed, and each measurement and each evaluation were performed by the above method. The results are shown in Table 1 and FIG.
  • Example 2 A polarizing film was prepared in the same manner as in Example 1 except that the time of immersion in the first fixing treatment bath was set to 100 seconds and the second fixing treatment was not performed, and each measurement and each evaluation were performed by the above method. It was. The results are shown in Table 1 and FIG.
  • Example 4 A polarizing film was prepared in the same manner as in Example 2 except that the time of immersion in the first fixing treatment bath was set to 100 seconds, and each measurement and each evaluation were performed by the above method. The results are shown in Table 1. However, since the boron-containing compound (C) was not adsorbed on the polarizing film, the shrinkage force, optical performance, and moisture heat resistance were not evaluated.
  • Example 6 The same as in Example 1 except that an aqueous solution (temperature 50 ° C.) containing 1.0% by mass of 1,4-butandiboronic acid and 5.5% by mass of potassium iodide was used in the second fixing treatment bath. A polarizing film was prepared, and each measurement and each evaluation were performed by the above method. The results are shown in Table 1 and FIG.
  • Example 10 A polarizing film was produced in the same manner as in Example 1 except that the first fixing treatment and the second fixing treatment were not performed, and each measurement and each evaluation were performed by the above method. The results are shown in Table 1 and FIG.
  • Comparative Example 12 A polarizing film was prepared in the same manner as in Comparative Example 11 except that the time of immersion in the first fixing treatment bath was set to 20 seconds, and each measurement and each evaluation were carried out by the above method. The results are shown in Table 1 and FIG.
  • Example 2 an aqueous solution (temperature 30 ° C.) containing iodine and potassium iodide at a mass ratio of 1: 100 was used for the dyeing treatment bath. At this time, the iodine and potassium iodide concentrations in the dyeing bath were adjusted so that the transmittance of the polarizing film after drying was 43.8% to 44.2%.
  • FIG. 2 is a diagram in which the shrinkage force is plotted on the horizontal axis and the attenuation coefficient of the PVA-iodine complex is plotted on the vertical axis for the polarizing films of Examples 1 and 2 and Comparative Examples 1 to 12.
  • the polarizing films of Examples 1 and 2 satisfying the provisions of the present invention have a shrinkage force of less than 5N, an attenuation coefficient of the PVA-iodine complex of -0.5 or more, and a low shrinkage force. It can be seen that it is also excellent in moisture and heat resistance.
  • the polarizing films of Comparative Examples 1 to 3 in which only the former was adsorbed had insufficient either a decrease in shrinkage force or moisture heat resistance. ..
  • the polarizing film of Comparative Example 5 in which only the latter is adsorbed, and the boron-containing compound (C) having a high concentration of the boron-containing compound (C) during the second fixing treatment The polarizing film of Comparative Example 6 in which C) was excessively adsorbed had sufficient moisture and heat resistance, but insufficient reduction in shrinkage force.
  • Hydrogen peak derived from heavy water as a measurement solvent Hydrogen peak derived from the methine group of PVA 3 Hydrogen peak derived from the methylene group of PVA 4 Hydrogen-containing compound (B) and boron-containing compound (C) that overlap with the hydrogen peak derived from PVA Hydrogen peak derived from hydrocarbon group contained in 5 Hydrogen peak derived from hydrocarbon group that does not overlap with hydrogen peak derived from PVA but overlaps with boron-containing compound (B) and boron-containing compound (C) 6 Hydrogen peak derived from PVA Does not overlap with the hydrogen peak derived from or boron-containing compound (C), Hydrogen peak derived from methyl group of boron-containing compound (B)

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Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20140075154A (ko) * 2012-12-11 2014-06-19 동우 화인켐 주식회사 편광자 제조용 가교제 및 이를 이용한 편광자의 제조방법
KR20150001276A (ko) * 2013-06-27 2015-01-06 동우 화인켐 주식회사 편광자의 제조방법 및 편광자
KR20150052777A (ko) * 2013-11-06 2015-05-14 동우 화인켐 주식회사 편광자의 제조방법
KR20160054229A (ko) * 2014-11-06 2016-05-16 동우 화인켐 주식회사 편광자의 제조방법
JP2018180022A (ja) * 2017-04-03 2018-11-15 日東電工株式会社 偏光子の製造方法
JP2019015926A (ja) * 2017-07-10 2019-01-31 株式会社クラレ 偏光フィルム及びその製造方法

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6484203A (en) 1987-09-26 1989-03-29 Nippon Synthetic Chem Ind Polarizing film having superior durability and its production
JP3357109B2 (ja) 1993-02-09 2002-12-16 株式会社クラレ 偏光膜の製造法
JPH06265727A (ja) 1993-03-16 1994-09-22 Kuraray Co Ltd 偏光膜の製造方法
JP2001343522A (ja) 2000-05-31 2001-12-14 Sumitomo Chem Co Ltd 偏光フィルム及びその製造方法
JP5831249B2 (ja) 2012-01-23 2015-12-09 住友化学株式会社 偏光フィルムとその製造方法及び偏光板
WO2015104966A1 (ja) * 2014-01-08 2015-07-16 株式会社クラレ 光学フィルム製造用原反フィルム
JP6649068B2 (ja) * 2015-12-07 2020-02-19 住友化学株式会社 偏光フィルムの製造方法
JP6858499B2 (ja) 2016-06-27 2021-04-14 株式会社クラレ 光学フィルムの製造方法
KR102327242B1 (ko) 2016-07-26 2021-11-16 주식회사 쿠라레 편광 필름 및 그 제조 방법

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20140075154A (ko) * 2012-12-11 2014-06-19 동우 화인켐 주식회사 편광자 제조용 가교제 및 이를 이용한 편광자의 제조방법
KR20150001276A (ko) * 2013-06-27 2015-01-06 동우 화인켐 주식회사 편광자의 제조방법 및 편광자
KR20150052777A (ko) * 2013-11-06 2015-05-14 동우 화인켐 주식회사 편광자의 제조방법
KR20160054229A (ko) * 2014-11-06 2016-05-16 동우 화인켐 주식회사 편광자의 제조방법
JP2018180022A (ja) * 2017-04-03 2018-11-15 日東電工株式会社 偏光子の製造方法
JP2019015926A (ja) * 2017-07-10 2019-01-31 株式会社クラレ 偏光フィルム及びその製造方法

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