WO2011114764A1 - Film de retardement et plaque de polarisation le comprenant - Google Patents

Film de retardement et plaque de polarisation le comprenant Download PDF

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Publication number
WO2011114764A1
WO2011114764A1 PCT/JP2011/050706 JP2011050706W WO2011114764A1 WO 2011114764 A1 WO2011114764 A1 WO 2011114764A1 JP 2011050706 W JP2011050706 W JP 2011050706W WO 2011114764 A1 WO2011114764 A1 WO 2011114764A1
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Prior art keywords
acid
film
retardation film
retardation
cellulose ester
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PCT/JP2011/050706
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English (en)
Japanese (ja)
Inventor
浩一 齋藤
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コニカミノルタオプト株式会社
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Priority to JP2012505541A priority Critical patent/JPWO2011114764A1/ja
Publication of WO2011114764A1 publication Critical patent/WO2011114764A1/fr

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    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/30—Polarising elements
    • G02B5/3083—Birefringent or phase retarding 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 retardation film and a polarizing plate provided with the retardation film. More specifically, the present invention relates to a retardation film that can be bonded to a polarizing plate without saponification and has good contrast and corner unevenness.
  • the decrease in contrast is more noticeable as the pH of the saponification solution is higher and the saponification temperature is higher. This is because when the hydrophilicity is imparted to the surface of the retardation film by saponification treatment, the degree of substitution in the vicinity of the film surface changes, causing unevenness in retardation, and additives are eluted in the saponification solution. This is probably because the orientation angle is shifted during the process of swelling and drying with moisture.
  • the adhesive strength with the polarizer may not be sufficient.
  • a method for producing a polarizing plate without saponification a method using an active energy ray-curable adhesive instead of water paste (for example, see Patent Document 1), a method for providing an easy-adhesion layer on a film (for example, Patent Document) 2)), etc., but sufficient adhesive strength cannot be obtained or new equipment is required.
  • JP 2008-040278 A JP 09-218302 A JP 2002-192656 A JP 2009-269944 A
  • the present invention has been made in view of the above-mentioned problems and situations, and the problem to be solved is a retardation film that can be bonded to a polarizing plate without being subjected to saponification treatment, and has good contrast and corner unevenness. Is to provide. Moreover, it is providing the polarizing plate provided with it. In particular, it is to provide a retardation film and the like suitably used for a large liquid crystal display device.
  • a retardation film comprising a cellulose ester resin having a total acyl substitution degree in the range of 2.0 to 2.5, wherein the retardation film is water having a pH of 6 to 8 at a temperature of 25 ° C.
  • the contact angle of the retardation film with respect to water after being soaked for 30 minutes and dried is in the range of 20 to 50 °, and the in-plane retardation value (Ro) of the retardation film at a measurement light wavelength of 590 nm is 30.
  • phase difference has a laminated structure in which a plurality of layers are laminated, and at least one surface layer of the laminated layers contains a polymer having an amide structure or an imide structure. the film.
  • a polarizing plate comprising the retardation film according to any one of items 1 to 4 above.
  • the present invention it is possible to provide a retardation film that can be bonded to a polarizing plate without being subjected to a saponification treatment and has good contrast and corner unevenness. Moreover, the polarizing plate provided with it can be provided. In particular, a retardation film or the like that can be suitably used for a large liquid crystal display device can be provided.
  • the retardation film of the present invention is a retardation film containing a cellulose ester resin having a total acyl substitution degree in the range of 2.0 to 2.5, and the retardation film has a pH of 6 at a temperature of 25 ° C.
  • the contact angle of the retardation film with respect to water after being immersed in water in the range of ⁇ 8 for 30 minutes and dried is in the range of 20 to 50 °, and in the plane of the retardation film at a measurement light wavelength of 590 nm
  • the retardation value (Ro) is in the range of 30 to 100 nm
  • the retardation value (Rt) in the thickness direction is in the range of 100 to 300 nm.
  • the retardation film of the present invention has a laminated structure in which a plurality of layers are laminated, and is formed on at least one surface layer of the laminated layers. It is preferable to contain a polymer having an amide structure or an imide structure.
  • the glass transition temperature (Tgs) of the surface layer and the glass transition temperature (Tgc) of the inner layer preferably satisfy the relational expression (1).
  • the film width after stretching is preferably 1900 mm or more.
  • the retardation film of the present invention can be suitably used for a polarizing plate.
  • the contact angle with water represents the affinity between the film and water, and the smaller the contact angle value, the easier it is to get wet with water.
  • the contact angle can be measured by a general method.
  • the film is immersed in pure water having a pH of 6 to 8 at 25 ° C. for 30 minutes and dried at 120 ° C. for 5 minutes.
  • the measurement was performed using a solid-liquid interface analysis system DropMaster500 manufactured by Kagaku Corporation.
  • the amount of water dripped at the time of measurement was 3 microliters, and the contact angle one minute after the dripping was measured.
  • a polyvinyl alcohol aqueous solution is generally used as an adhesive for bonding the film and the polarizer, but it is known that the adhesive force increases as the contact angle value is smaller. As a result of the examination, it was found that when the contact angle is 50 ° or less, an adhesive force having no practical problem can be obtained, but 40 ° or less is more preferable.
  • the contact angle of a film made of a cellulose ester resin having a total acyl substitution degree in the range of 2.0 to 2.5 is about 60 to 75 °, and sufficient adhesive strength with a polarizer cannot be obtained as it is.
  • the film surface is hydrolyzed to reduce the contact angle to about 20 ° to 40 ° to develop the adhesive force.
  • the alkali saponification treatment reduces the total acyl substitution degree of the cellulose ester resin by hydrolysis, but the total acyl substitution degree correlates with the retardation development property, which causes variation in the retardation.
  • the contact angle measured after soaking the film in pure water at 25 ° C. of pH 6-8 for 30 minutes and drying at 120 ° C. for 5 minutes is 20 ° -50 °
  • the total acyl substitution degree is 2.0. It was found that the cellulose ester resin film in the range of ⁇ 2.5 adheres to the polarizer without the alkali saponification treatment. If the contact angle is 50 ° or more, sufficient adhesion cannot be obtained, and if it is 20 ° or less, blocking or the like when stored in a wound shape deteriorates.
  • the cellulose ester resin according to the present invention has a total acyl substitution degree in the range of 2.0 to 2.5, and the total acyl substitution degree is more preferably 2.2 to 2.5.
  • the total acyl substitution degree referred to here is an average value of the number of esterified hydroxyl groups (hydroxyl groups) among the three hydroxyl groups (hydroxyl groups) of anhydroglucose constituting cellulose, and is from 0 to 3 Indicates the value.
  • the total acyl substitution degree of the cellulose ester resin is less than 2.0, deterioration of the film surface quality due to an increase in dope viscosity, haze-up due to an increase in stretching tension, etc. may occur. Moreover, when the total acyl substitution degree is 2.5 or more, a necessary phase difference cannot be obtained.
  • the acyl group is preferably an aliphatic acyl group.
  • the portion not substituted with an acyl group usually exists as a hydroxyl group (hydroxyl group).
  • the cellulose ester resin according to the present invention is preferably at least one selected from cellulose diacetate, cellulose acetate propionate, and cellulose acetate butyrate.
  • a particularly preferable cellulose ester resin is cellulose diacetate.
  • the degree of substitution of acetyl groups and the degree of substitution of other acyl groups were determined by the methods prescribed in ASTM-D817-96 (test method for cellulose acetate etc.).
  • the number average molecular weight (Mn) of the cellulose ester according to the present invention is preferably in the range of 30,000 to 300,000, since the mechanical strength of the resulting film is strong. Further, 50,000 to 200,000 are preferably used.
  • the ratio Mw / Mn of the weight average molecular weight (Mw) and the number average molecular weight (Mn) of the cellulose ester is preferably 1.4 to 3.0.
  • the weight average molecular weight Mw and number average molecular weight Mn of the cellulose ester were measured using gel permeation chromatography (GPC).
  • the measurement conditions are as follows.
  • the cellulose as a raw material of the cellulose ester according to the present invention is not particularly limited, and examples thereof include cotton linter, wood pulp, and kenaf. Moreover, the cellulose ester obtained from them can be mixed and used in arbitrary ratios, respectively.
  • the cellulose ester according to the present invention can be produced by a known method.
  • cellulose is esterified by mixing cellulose as a raw material, a predetermined organic acid (such as acetic acid or propionic acid), an acid anhydride (such as acetic anhydride or propionic anhydride), and a catalyst (such as sulfuric acid).
  • a predetermined organic acid such as acetic acid or propionic acid
  • an acid anhydride such as acetic anhydride or propionic anhydride
  • a catalyst such as sulfuric acid
  • the reaction proceeds until the triester is formed.
  • three hydroxyl groups (hydroxyl groups) of the glucose unit are substituted with an acyl acid of an organic acid.
  • a mixed ester type cellulose ester such as cellulose acetate propionate or cellulose acetate butyrate can be produced.
  • the cellulose triester is hydrolyzed to synthesize a cellulose ester having a desired degree of acyl substitution.
  • the cellulose ester is completed through steps such as filtration, precipitation, washing with water, dehydration, and drying.
  • Examples of commercially available products include L20, L30, L40, and L50 manufactured by Daicel Chemical Industries, Ltd., and Ca398-3, Ca398-6, Ca398-10, Ca398-30, and Ca394-60S manufactured by Eastman Chemical.
  • the total amount of calcium and magnesium and the amount of acetic acid contained in the cellulose ester film according to the present invention preferably satisfy the following relational expression (a).
  • the total amount of calcium and magnesium contained in the cellulose ester film referred to in the present invention refers to the total amount thereof.
  • acetic anhydride and acetic acid are used as reaction solvents and esterifying agents. Unreacted acetic anhydride is hydrolyzed by a reaction stopper (water, alcohol, acetic acid, etc.) to produce acetic acid.
  • a reaction stopper water, alcohol, acetic acid, etc.
  • the amount of acetic acid contained in the cellulose ester film in the present invention refers to the total amount of residual acetic acid and free acetic acid.
  • the total amount of calcium and magnesium contained in the cellulose ester film is preferably 5 to 130 ppm, more preferably 5 to 80 ppm, and still more preferably 5 to 50 ppm.
  • a known method can be used. For example, after the dried cellulose ester is completely burned, the ash is dissolved in hydrochloric acid and pretreated. It can be measured by atomic absorption method. The measured value is obtained in units of ppm as the calcium and magnesium contents in 1 g of the completely dry cellulose ester.
  • the amount of acetic acid contained in the cellulose ester film is preferably 20 to 500 ppm, more preferably 25 to 250 ppm, and still more preferably 30 to 150 ppm.
  • acetic acid contained in the cellulose ester film For quantification of acetic acid contained in the cellulose ester film, a known method can be used. For example, the following method can be used. The film is dissolved in methylene chloride, and methanol is added to perform reprecipitation. The amount of acetic acid can be obtained by filtering the supernatant and measuring the supernatant with gas chromatography.
  • the surface layer of the retardation film of the present invention preferably contains a polymer having an amide structure or an imide structure (hereinafter sometimes referred to as amide or imide polymer).
  • amide or imide polymer By containing an amide or imide polymer, affinity with water can be imparted. Further, since it has excellent compatibility with the cellulose ester resin having a total acyl substitution degree in the range of 2.0 to 2.5, transparency such as haze is also good.
  • polymer having an amide structure examples include N-vinylpyrrolidone (VP), N-vinyl-2-methylpyrrolidone, acryloylmorpholine (ACMO), acryloyl-2-methylmorpholine, dimethylacrylamide (DMAA), vinylacetamide and the like. It refers to a polymer having as a copolymerization component. In particular, N-vinylpyrrolidone, acryloylmorpholine, and dimethylacrylamide are preferable.
  • the polymer having an imide structure refers to a polymer having methylmaleimide (MMI), glutarimide or the like as a copolymerization component.
  • MMI methylmaleimide
  • glutarimide glutarimide
  • methylmaleimide is preferred.
  • Examples of monomers copolymerizable with these amide or imide polymers include alkyl methacrylates having 2 to 18 alkyl carbon atoms, alkyl acrylates having 1 to 18 carbon atoms, acrylic acid, methacrylic acid, and the like.
  • ⁇ , ⁇ -unsaturated acids maleic acids, fumaric acids, dicarboxylic acids containing unsaturated groups such as itaconic acid, aromatic vinyl compounds such as styrene and ⁇ -methylstyrene, ⁇ , ⁇ such as acrylonitrile and methacrylonitrile -Unsaturated nitrile, maleic anhydride, glutaric anhydride and the like can be mentioned, and these can be used alone or in combination of two or more monomers.
  • styrene vinyl acetate, acrylic acid, methyl acrylate (MA), ethyl acrylate, propyl acrylate, butyl acrylate, methacrylic acid, methyl methacrylate (MMA), ethyl methacrylate, propyl methacrylate, methacryl Acid butyl, 2-hydroxyethyl methacrylate (HEMA), and the like.
  • MMA methyl methacrylate
  • MMA methyl methacrylate
  • HEMA 2-hydroxyethyl methacrylate
  • methyl methacrylate, methyl acrylate, vinyl acetate, and 2-hydroxyethyl methacrylate are preferable.
  • the copolymerization ratio of these copolymer components having an amide structure or an imide structure is preferably 10 to 100 mol%, more preferably 20 to 80 mol% of the total copolymer components constituting the polymer.
  • the number average molecular weight (Mn) of the amide or imide polymer is preferably about 1,000 to 100,000, more preferably about 5,000 to 50,000.
  • the molecular weight can be measured by the same method as the cellulose ester.
  • the production method of the amide or imide polymer in the present invention is not particularly limited, and any known method such as suspension polymerization, emulsion polymerization, bulk polymerization, or solution polymerization may be used.
  • a polymerization initiator a normal peroxide type, azo type, or redox type can be used.
  • the polymerization temperature may be 30 to 100 ° C. for suspension or emulsion polymerization, and 80 to 160 ° C. for bulk or solution polymerization.
  • polymerization can be carried out using alkyl mercaptan or the like as a chain transfer agent.
  • the amide or imide polymer is preferably used in an amount of 2 to 70% by mass in the cellulose ester resin, and more preferably 5 to 50% by mass. If the addition amount is too small, the effect of the amide or imide polymer cannot be exhibited, and if the addition amount is too large, the water absorption is deteriorated.
  • the retardation film of the present invention may be a single layer film or a laminated structure film in which a plurality of layers are laminated.
  • the two outermost layers may be referred to as a surface layer or a skin layer.
  • the layer inside the surface layer may be called a core layer.
  • the total number of laminated structures is not particularly limited, but is preferably three layers.
  • the effect of the present invention is not sufficient with two layers, and the manufacturing apparatus becomes complicated with four or more layers.
  • the cellulose ester solution to be cast preferably contains the above-mentioned amide or imide polymer in at least one layer in the case of a two-layer structure and in at least one surface layer in the case of three or more layers.
  • the most preferred form is to have an amide or imide polymer in both surface layers in a three-layer laminate structure.
  • the thickness of the surface layer and the inner layer is not particularly limited. However, in the case of a laminate of three or more layers, the surface layer is preferably 1 to 50% of the total thickness, more preferably 2 to 30 in total. % Thickness.
  • ⁇ Hydrolysis inhibitor> You may add a hydrolysis inhibiting agent to the retardation film of this invention as needed.
  • the hydrolysis inhibitor is not particularly limited, but the octanol-water partition coefficient (hereinafter sometimes referred to as logP) is preferably 7 or more and less than 11 from the viewpoint of hydrolysis prevention effect, compatibility with cellulose ester, and the like.
  • logP value can be measured by a flask soaking method described in JIS Z-7260-107 (2000).
  • logP can be estimated by a computational chemical method or an empirical method instead of actual measurement.
  • Crippen's fragmentation method J. Chem. Inf. Comput. Sci.”, 27, p21 (1987)
  • Viswanadhan's fragmentation method J. Chem. Inf. Comput. Sci.”
  • Broto's fragmentation method Eur. J. Med. Chem.-Chim. Theor. ", 19, p71 (1984)
  • CLogP method references
  • Leo, A., Jow, PYC, Silipo, C., Hansch, C., J. Med. Chem., 18, 865, 1975 are preferably used, but the Crippen's fragmentation method ( “JC em.Inf.Comput.Sci.”, 27 volumes, p21 (1987 years)) is more preferable.
  • an ester compound having at least one pyranose structure or at least one furanose structure and 12 or less OH groups in the structure can be preferably used.
  • the proportion of esterification is preferably 70% or more.
  • ester compounds are collectively referred to as sugar ester compounds.
  • ester compounds used in the present invention include the following saccharide ester compounds, but the present invention is not limited to these.
  • Glucose galactose, mannose, fructose, xylose, arabinose, lactose, sucrose, nystose, 1F-fructosyl nystose, stachyose, maltitol, lactitol, lactulose, cellobiose, maltose, cellotriose, maltotriose, raffinose or kestose.
  • gentiobiose gentiotriose
  • gentiotetraose gentiotetraose
  • xylotriose galactosyl sucrose
  • compounds having both a pyranose structure and a furanose structure are particularly preferable.
  • Preferred examples include sucrose, kestose, nystose, 1F-fructosyl nystose, stachyose, and more preferably sucrose.
  • the monocarboxylic acid used for esterifying all or part of the OH group in the pyranose structure or furanose structure is not particularly limited, and is a known aliphatic monocarboxylic acid, alicyclic monocarboxylic acid, aromatic A monocarboxylic acid or the like can be used.
  • the carboxylic acid used may be one kind or a mixture of two or more kinds.
  • Preferred aliphatic monocarboxylic acids include acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, 2-ethyl-hexanecarboxylic acid, undecylic acid, lauric acid , Saturated fatty acids such as tridecylic acid, myristic acid, pentadecylic acid, palmitic acid, heptadecylic acid, stearic acid, nonadecanoic acid, arachidic acid, behenic acid, lignoceric acid, serotic acid, heptacosanoic acid, montanic acid, melicic acid, and laccelic acid, Examples include unsaturated fatty acids such as undecylenic acid, oleic acid, sorbic acid, linoleic acid, linolenic acid, arachidonic acid and oc
  • Examples of preferred alicyclic monocarboxylic acids include cyclopentane carboxylic acid, cyclohexane carboxylic acid, cyclooctane carboxylic acid, and derivatives thereof.
  • aromatic monocarboxylic acids examples include aromatic monocarboxylic acids having an alkyl group or alkoxy group introduced into the benzene ring of benzoic acid such as benzoic acid and toluic acid, cinnamic acid, benzylic acid, biphenylcarboxylic acid, and naphthalene.
  • aromatic monocarboxylic acids having two or more benzene rings such as carboxylic acid and tetralincarboxylic acid, or derivatives thereof.
  • Oligosaccharide ester compounds can be applied as compounds having 1 to 12 of at least one of the pyranose structure or furanose structure according to the present invention.
  • Oligosaccharides are produced by allowing an enzyme such as amylase to act on starch, sucrose, etc.
  • examples of oligosaccharides that can be applied to the present invention include maltooligosaccharides, isomaltoligosaccharides, fructooligosaccharides, galactooligosaccharides, xylooligos. Sugar.
  • the said ester compound is a compound which condensed 1 or more and 12 or less of at least 1 type of the pyranose structure or furanose structure represented with the following general formula (A).
  • R 11 to R 15 and R 21 to R 25 each represents an acyl group having 2 to 22 carbon atoms or a hydrogen atom, m and n each represents an integer of 0 to 12, and m + n represents an integer of 1 to 12.
  • R 11 to R 15 and R 21 to R 25 are preferably a benzoyl group or a hydrogen atom.
  • the benzoyl group may further have a substituent R 26 , and examples thereof include an alkyl group, an alkenyl group, an alkoxyl group, and a phenyl group, and these alkyl group, alkenyl group, and phenyl group have a substituent. May be. Oligosaccharides can also be produced in the same manner as the ester compound according to the present invention.
  • ester compound according to the present invention will be given below, but the present invention is not limited thereto.
  • the cellulose ester film according to the present invention preferably contains a hydrolysis inhibitor in an amount of 0.5 to 30% by mass, particularly 2 to 15% by mass of the cellulose ester film.
  • a retardation adjusting agent (also referred to as “retardation adjusting agent”) may be added to the retardation film of the present invention.
  • phase difference adjusting agent is not particularly limited, a compound having a log P of 0 or more and less than 7 is preferable.
  • the phase difference adjusting agent needs to have an appropriate solubility corresponding to the resin.
  • the log P is smaller than 0, the compound is highly water-soluble, causing orientation disorder.
  • it is 7 or more, the desired phase difference cannot be obtained because the orientation of the compound is low, which is not preferable.
  • phase difference adjusting agent for example, an ester compound represented by the following general formula (B) can be preferably used.
  • A represents an alkylene dicarboxylic acid residue having 4 to 12 carbon atoms or an aryl dicarboxylic acid residue having 6 to 12 carbon atoms, and n represents an integer of 1 or more.
  • a hydroxyl group or a carboxylic acid residue represented by B an alkylene glycol residue, an oxyalkylene glycol residue or an aryl glycol residue represented by G, an alkylene dicarboxylic acid residue represented by A or It is composed of an aryl dicarboxylic acid residue and can be obtained by the same reaction as that of a normal ester compound.
  • the carboxylic acid component represented by B for example, acetic acid, propionic acid, butyric acid, benzoic acid, p-tert-butylbenzoic acid, orthotoluic acid, metatoluic acid, p-toluic acid, dimethylbenzoic acid,
  • acetic acid, propionic acid, butyric acid, benzoic acid, p-tert-butylbenzoic acid, orthotoluic acid, metatoluic acid, p-toluic acid, dimethylbenzoic acid There are ethyl benzoic acid, normal propyl benzoic acid, aminobenzoic acid, acetoxybenzoic acid, aliphatic acid, and the like, and these can be used as one kind or a mixture of two or more kinds, respectively.
  • the alkylene glycol component having 2 to 12 carbon atoms represented by G includes ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butanediol, 1, 3-butanediol, 1,2-propanediol, 2-methyl-1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 2,2-dimethyl-1,3-propanediol (neo Pentyl glycol), 2,2-diethyl-1,3-propanediol (3,3-dimethylolpentane), 2-n-butyl-2-ethyl-1,3-propanediol (3,3-dimethylolheptane) 3-methyl-1,5-pentanediol 1,6-hexanediol, 2,2,4-trimethyl 1,3-pentanediol, 1,3
  • examples of the alkylene dicarboxylic acid component having 4 to 12 carbon atoms represented by A include succinic acid, maleic acid, fumaric acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, and dodecanedicarboxylic acid.
  • acids and the like are used as one kind or a mixture of two or more kinds, respectively.
  • examples of the arylene dicarboxylic acid component having 6 to 12 carbon atoms include phthalic acid, terephthalic acid, isophthalic acid, 1,5 naphthalene dicarboxylic acid, and 1,4 naphthalene dicarboxylic acid.
  • the ester compound represented by the general formula (B) has a number average molecular weight of preferably 300 to 2000, more preferably 400 to 1500.
  • the acid value is 0.5 mgKOH / g or less
  • the hydroxyl group (hydroxyl group) value is 25 mgKOH / g or less, more preferably the acid value is 0.3 mgKOH / g or less
  • the hydroxyl group (hydroxyl group) value is 15 mgKOH / g or less. It is.
  • the retardation film according to the present invention preferably contains a retardation adjusting agent in an amount of 0.1 to 30% by mass of the cellulose ester film, and particularly preferably 0.5 to 10% by mass.
  • ⁇ Plasticizer> You may make the retardation film of this invention contain a plasticizer as needed. Although it does not specifically limit as a plasticizer which can be contained, for example, a polyhydric alcohol ester plasticizer, a polyhydric carboxylic ester plasticizer, a glycolate plasticizer, a phosphate ester plasticizer, a phthalate ester A plasticizer, a fatty acid ester plasticizer, an acrylic polymer, or the like can be used. Moreover, it is preferable that the addition amount of a phosphoric ester plasticizer shall be 6 mass% or less from a durable viewpoint of a polarization degree.
  • the plasticizer preferably has a 1% weight loss temperature (Td1) of 250 ° C. or higher, more preferably 280 ° C. or higher, and particularly preferably 300 ° C. or higher.
  • Td1 1% weight loss temperature
  • the polyhydric alcohol ester plasticizer is a plasticizer composed of an ester of a divalent or higher aliphatic polyhydric alcohol and a monocarboxylic acid, and preferably has an aromatic ring or a cycloalkyl ring in the molecule.
  • a divalent to 20-valent aliphatic polyhydric alcohol ester is preferred.
  • the polyhydric alcohol preferably used in the present invention is represented by the following general formula (a).
  • R 1 represents an n-valent organic group
  • n represents a positive integer of 2 or more
  • the OH group represents an alcoholic hydroxyl group (hydroxyl group) or a phenolic hydroxyl group (hydroxyl group).
  • preferable polyhydric alcohols include the following, but the present invention is not limited to these.
  • triethylene glycol triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, sorbitol, glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, and xylitol are preferable.
  • monocarboxylic acid used for polyhydric alcohol ester there is no restriction
  • Examples of preferred monocarboxylic acids include the following, but the present invention is not limited thereto.
  • aliphatic monocarboxylic acid a fatty acid having a straight chain or a side chain having 1 to 32 carbon atoms can be preferably used. More preferably, it has 1 to 20 carbon atoms, and particularly preferably 1 to 10 carbon atoms.
  • acetic acid is preferred because the compatibility with the cellulose ester increases, and it is also preferred to use a mixture of acetic acid and another monocarboxylic acid.
  • Preferred aliphatic monocarboxylic acids include acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, 2-ethyl-hexanoic acid, undecylic acid, lauric acid, tridecylic acid, Saturated fatty acids such as myristic acid, pentadecylic acid, palmitic acid, heptadecylic acid, stearic acid, nonadecanoic acid, arachidic acid, behenic acid, lignoceric acid, serotic acid, heptacosanoic acid, montanic acid, melicic acid, and laccelic acid, undecylenic acid, olein Examples thereof include unsaturated fatty acids such as acid, sorbic acid, linoleic acid, linolenic acid, and arachidonic acid.
  • Preferred alicyclic monocarboxylic acids are preferably cycloalkyl groups having 3 to 8 carbon atoms, and specific examples include cyclopentanecarboxylic acid, cyclohexanecarboxylic acid, cyclooctanecarboxylic acid, and derivatives thereof.
  • aromatic monocarboxylic acids examples include those in which 1 to 3 alkoxy groups such as an alkyl group, a methoxy group or an ethoxy group are introduced into the benzene ring of benzoic acid such as benzoic acid and toluic acid, biphenylcarboxylic acid, Examples thereof include aromatic monocarboxylic acids having two or more benzene rings such as naphthalenecarboxylic acid and tetralincarboxylic acid, or derivatives thereof. In particular, benzoic acid is preferred.
  • the molecular weight of the polyhydric alcohol ester is not particularly limited, but is preferably in the range of 300 to 1500, and more preferably in the range of 400 to 1000. A higher molecular weight is preferred because it is less likely to volatilize, and a smaller one is preferred in terms of moisture permeability and compatibility with cellulose ester.
  • the monocarboxylic acid used in the polyhydric alcohol ester may be one kind or a mixture of two or more kinds. Moreover, all the OH groups in the polyhydric alcohol may be esterified, or a part of the OH groups may be left as they are.
  • the polyhydric alcohol ester can be synthesized by a known method. For example, a method of condensing and esterifying the monocarboxylic acid and the polyhydric alcohol in the presence of an acid, a method of previously reacting an organic acid with an acid chloride or acid anhydride and reacting with the polyhydric alcohol, There is a method of reacting a phenyl ester and a polyhydric alcohol, and it is preferable to select a method with a good yield appropriately depending on the target ester compound.
  • the polyvalent carboxylic acid ester compound is composed of an ester of a divalent or higher, preferably a divalent to 20valent polyvalent carboxylic acid and an alcohol.
  • the aliphatic polyvalent carboxylic acid is preferably divalent to 20-valent, and in the case of an aromatic polyvalent carboxylic acid or alicyclic polyvalent carboxylic acid, it is preferably trivalent to 20-valent.
  • the polyvalent carboxylic acid is represented by the following general formula (c).
  • R 2 (COOH) m (OH) n
  • R 2 is an (m + n) -valent organic group
  • m is a positive integer of 2 or more
  • n is an integer of 0 or more
  • COOH group is a carboxyl group
  • OH group is an alcoholic or phenolic hydroxyl group (hydroxyl group).
  • Examples of preferred polyvalent carboxylic acids include the following, but the present invention is not limited to these.
  • Trivalent or higher aromatic polyvalent carboxylic acids such as trimellitic acid, trimesic acid, pyromellitic acid or derivatives thereof, succinic acid, adipic acid, azelaic acid, sebacic acid, oxalic acid, fumaric acid, maleic acid, tetrahydrophthal
  • An aliphatic polyvalent carboxylic acid such as an acid, an oxypolyvalent carboxylic acid such as tartaric acid, tartronic acid, malic acid and citric acid can be preferably used.
  • the alcohol used in the polyvalent carboxylic acid ester compound that can be used in the present invention is not particularly limited, and known alcohols and phenols can be used.
  • an aliphatic saturated alcohol or aliphatic unsaturated alcohol having a straight chain or a side chain having 1 to 32 carbon atoms can be preferably used. More preferably, it has 1 to 20 carbon atoms, and particularly preferably 1 to 10 carbon atoms.
  • alicyclic alcohols such as cyclopentanol and cyclohexanol or derivatives thereof
  • aromatic alcohols such as benzyl alcohol and cinnamyl alcohol, or derivatives thereof can be preferably used.
  • the alcoholic or phenolic hydroxyl group (hydroxyl group) of the oxypolycarboxylic acid may be esterified with a monocarboxylic acid.
  • monocarboxylic acids include the following, but the present invention is not limited thereto.
  • aliphatic monocarboxylic acid a straight-chain or side-chain fatty acid having 1 to 32 carbon atoms can be preferably used. More preferably, it has 1 to 20 carbon atoms, and particularly preferably 1 to 10 carbon atoms.
  • Preferred aliphatic monocarboxylic acids include acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, 2-ethyl-hexanecarboxylic acid, undecylic acid, lauric acid, tridecylic acid, Saturated fatty acids such as myristic acid, pentadecylic acid, palmitic acid, heptadecylic acid, stearic acid, nonadecanoic acid, arachidic acid, behenic acid, lignoceric acid, serotic acid, heptacosanoic acid, montanic acid, melicic acid, and laccelic acid, undecylenic acid, olein Examples thereof include unsaturated fatty acids such as acid, sorbic acid, linoleic acid, linolenic acid, and arachidonic acid.
  • Examples of preferred alicyclic monocarboxylic acids include cyclopentane carboxylic acid, cyclohexane carboxylic acid, cyclooctane carboxylic acid, and derivatives thereof.
  • aromatic monocarboxylic acids examples include those in which an alkyl group is introduced into the benzene ring of benzoic acid such as benzoic acid and toluic acid, and two or more benzene rings such as biphenylcarboxylic acid, naphthalenecarboxylic acid, and tetralincarboxylic acid.
  • benzoic acid and toluic acid examples include biphenylcarboxylic acid, naphthalenecarboxylic acid, and tetralincarboxylic acid.
  • the aromatic monocarboxylic acid which has, or derivatives thereof can be mentioned. Particularly preferred are acetic acid, propionic acid, and benzoic acid.
  • the molecular weight of the polyvalent carboxylic acid ester compound is not particularly limited, but is preferably in the range of 300 to 1000, and more preferably in the range of 350 to 750.
  • the larger one is preferable in terms of improvement in retention, and the smaller one is preferable in terms of moisture permeability and compatibility with cellulose ester.
  • the alcohol used for the polyvalent carboxylic acid ester that can be used in the present invention may be one kind or a mixture of two or more kinds.
  • dibutyl tartrate diacetyl dibutyl tartrate, triethyl citrate, tributyl citrate, acetyl triethyl citrate (ATEC), acetyl tributyl citrate (ATBC), benzoyl tributyl citrate, acetyl triphenyl citrate, acetyl tribenzyl citrate, Tributyl trimesate, trihexyl trimesate, tri-2-ethyl-hexyl trimesate, tricyclohexyl trimesate, tributyl trimellitic acid, trihexyl trimellitic acid, tri-2-ethyl-hexyl trimellitic acid, tricyclohexyl trimellitic acid, pyromellitic Examples include tetrabutyl acid, pyromellitic acid tetrahexyl, pyromellitic acid tetra-2-ethylhexylhe
  • the glycolate plasticizer is not particularly limited, but alkylphthalylalkyl glycolates can be preferably used.
  • alkyl phthalyl alkyl glycolates include methyl phthalyl methyl glycolate, ethyl phthalyl ethyl glycolate, propyl phthalyl propyl glycolate, butyl phthalyl butyl glycolate, octyl phthalyl octyl glycolate, methyl phthalyl ethyl Glycolate, ethyl phthalyl methyl glycolate, ethyl phthalyl propyl glycolate, methyl phthalyl butyl glycolate, ethyl phthalyl butyl glycolate, butyl phthalyl methyl glycolate, butyl phthalyl ethyl glycolate, propyl phthalyl butyl glycol Butyl phthalyl propyl glycolate, methyl phthalyl octyl glycolate, ethyl phthalyl octyl glycolate, octyl phthalyl
  • Phosphate ester plasticizers include triphenyl phosphate, tricresyl phosphate, cresyl diphenyl phosphate, octyl diphenyl phosphate, diphenyl biphenyl phosphate, trioctyl phosphate, tributyl phosphate, 1,3-phenylenebis (dixylenyl phosphate), 1,3-phenylenebis (diphenyl phosphate) and the like.
  • phthalate ester plasticizer diethyl phthalate, dimethoxyethyl phthalate, dimethyl phthalate, dioctyl phthalate, dibutyl phthalate, butyl benzyl phthalate, di-2-ethylhexyl phthalate, dicyclohexyl phthalate, dicyclohexyl terephthalate and the like can be used.
  • fatty acid ester plasticizers examples include butyl oleate, methylacetyl ricinoleate, and dibutyl sebacate.
  • epoxidized oil plasticizers can also be used.
  • the retardation film of the present invention can also contain an ultraviolet absorber.
  • the ultraviolet absorber is intended to improve durability by absorbing ultraviolet light having a wavelength of 400 nm or less, and the transmittance at a wavelength of 370 nm is particularly preferably 10% or less, more preferably 5% or less. Preferably it is 2% or less.
  • the ultraviolet absorber used in the present invention is not particularly limited, for example, oxybenzophenone compounds, benzotriazole compounds, salicylic acid ester compounds, benzophenone compounds, cyanoacrylate compounds, triazine compounds, nickel complex compounds, inorganic powders Examples include the body. It is good also as a polymer type ultraviolet absorber.
  • ultraviolet absorbers include, for example, 5-chloro-2- (3,5-di-sec-butyl-2-hydroxylphenyl) -2H-benzotriazole, (2-2H-benzotriazol-2-yl) -6- (straight and side chain dodecyl) -4-methylphenol, 2-hydroxy-4-benzyloxybenzophenone, 2,4-benzyloxybenzophenone, discoidal compounds such as compounds having 1,3,5 triazine ring.
  • commercially available ultraviolet absorbers such as TINUVIN109, TINUVIN171, TINUVIN326, TINUVIN327, TINUVIN328, TINUVIN900, and TINUVIN928 manufactured by BASF Japan Ltd., and LA-31 manufactured by ADEKA can also be preferably used.
  • UV absorbers preferably used in the present invention are benzotriazole-based UV absorbers, benzophenone-based UV absorbers, and triazine-based UV absorbers.
  • a polymeric ultraviolet absorber can be preferably used, and in particular, a polymer type ultraviolet absorber described in JP-A-6-148430 is preferably used.
  • the ultraviolet absorber may be used alone or as a mixture of two or more.
  • the amount of UV absorber used is not uniform depending on the type of UV absorber, usage conditions, etc., but when the dry film thickness of the film is 30 to 200 ⁇ m, it is preferably 0.5 to 10% by mass relative to the film. 0.6 to 4% by mass is more preferable.
  • Antioxidants, thermal degradation inhibitors When a liquid crystal image display device or the like is placed in a high humidity and high temperature state, the cellulose ester film may be deteriorated. Antioxidants and thermal degradation inhibitors have a role of delaying or preventing the cellulose ester film from being decomposed by, for example, the residual solvent amount of halogen in the cellulose ester film or phosphoric acid of a phosphoric acid plasticizer. Therefore, it is preferable to make it contain in the said cellulose-ester film.
  • an antioxidant and a thermal degradation inhibitor generally known degradation inhibitors (antioxidants, peroxide decomposition agents, radical inhibitors, metal deactivators, acid scavengers, amines, etc.) ) Can be used.
  • degradation inhibitors antioxidants, peroxide decomposition agents, radical inhibitors, metal deactivators, acid scavengers, amines, etc.
  • lactone, sulfur, phenol, double bond, hindered amine, and phosphorus compounds can be preferably used.
  • the deterioration preventing agents are described in JP-A-3-199201, JP-A-5-194789, JP-A-5-194789, JP-A-5-271471, and JP-A-6-107854.
  • phenolic compound those having a 2,6-dialkylphenol structure are preferable, for example, those commercially available from BASF Japan under the trade names Irganox 1076 and Irganox 1010 are preferable.
  • Examples of the phosphorus compounds include Sumitizer Chemical Co., Ltd., Sumilizer-GP, ADEKA Co., Ltd., ADK STAB PEP-24G, ADK STAB PEP-36 and ADK STAB 3010, and BASF Japan Co., Ltd. IRGAFOS P-EPQ.
  • a product commercially available from Sakai Chemical Co., Ltd. under the trade name GSY-P101 is preferred.
  • the hindered amine compound is preferably commercially available from BASF Japan, Inc. under the trade names of Tinuvin 144 and Tinuvin 770, and ADEKA, Inc., ADK STAB LA-52.
  • the above sulfur compounds are preferably those commercially available from Sumitomo Chemical Co., Ltd. under the trade names Sumilizer TPL-R and Sumilizer TP-D.
  • the above-mentioned double bond compounds are preferably those commercially available from Sumitomo Chemical Co., Ltd. under the trade names Sumilizer-GM and Sumilizer-GS.
  • the amount of these antioxidants and the like to be added is appropriately determined in accordance with the process at the time of recycling. Generally, the range of 0.05 to 5% by mass with respect to the resin as the main raw material of the film. Is added.
  • antioxidants and thermal deterioration inhibitors can obtain a synergistic effect by using several different types of compounds in combination rather than using only one kind.
  • the combined use of lactone, phosphorus, phenol and double bond compounds is preferred.
  • a colorant may be used.
  • the colorant means a dye or a pigment, but in the present invention, it means a material having an effect of adjusting the yellow index (yellowness) of the film and reducing haze.
  • dyes and pigments can be used as the colorant, but anthraquinone dyes, azo dyes, phthalocyanine pigments and the like are effective.
  • inorganic fine particles may be added as a matting agent in order to impart slipperiness to the film.
  • inorganic compounds include silicon dioxide (silica), titanium dioxide, aluminum oxide, zirconium oxide, calcium carbonate, calcium carbonate, talc, clay, calcined kaolin, calcined calcium silicate, hydrated calcium silicate, aluminum silicate, silica Mention may be made of magnesium and calcium phosphates. Among these, silicon dioxide is preferable in terms of reducing haze.
  • the matting agent fine particles are surface-treated with an organic substance because the haze of the film can be reduced.
  • organic materials for the surface treatment include halosilanes, alkoxysilanes, silazanes, siloxanes, and the like.
  • the average particle diameter of the primary particles of the fine particles is preferably 5 to 20 nm, and more preferably 5 to 12 nm.
  • These fine particles preferably form secondary particles having a particle diameter of 0.1 to 5 ⁇ m and are contained in the retardation film, and a preferable average particle diameter is 0.1 to 2 ⁇ m, more preferably 0.2. ⁇ 0.6 ⁇ m. Thereby, irregularities having a height of about 0.1 to 1.0 ⁇ m can be formed on the film surface, and appropriate slipperiness can be given to the film surface.
  • the primary average particle diameter of the fine particles used in the present invention is measured by observing the particles with a transmission electron microscope (magnification of 500,000 to 2,000,000 times), observing 100 particles, measuring the particle diameter, and measuring the average. The value was taken as the primary average particle size.
  • the content of these fine particles in the cellulose ester film is preferably 0.05 to 1% by mass, particularly preferably 0.1 to 0.8% by mass.
  • the surface layer contains fine particles of this addition amount.
  • the fine particles of silicon dioxide are, for example, trade names Aerosil R972, R972V, R974, R812, 200, 200V, 300, R202, R812V, OX50, TT600, NAX50 (manufactured by Nippon Aerosil Co., Ltd.), Seahoster KE-P10, KE-P30, KE-P50, KE-P100 (manufactured by Nippon Shokubai Co., Ltd.) and the like can be used.
  • Zirconium oxide fine particles are commercially available under the trade names of Aerosil R976 and R811 (manufactured by Nippon Aerosil Co., Ltd.) and can be used.
  • Examples of the polymer include silicone resin, fluororesin and acrylic resin. Silicone resins are preferable, and those having a three-dimensional network structure are particularly preferable. For example, Tospearl 103, 105, 108, 120, 145, 3120, and 240 (manufactured by Toshiba Silicone Co., Ltd.) It is marketed by name and can be used.
  • Aerosil 200V, R812V, R972V, NAX50, and Seahoster KE-P30 are particularly preferably used because they have a large effect of reducing the friction coefficient while keeping the turbidity of the cellulose ester film low.
  • the apparent specific gravity of the fine particles is preferably 70 g / liter or more, more preferably 90 to 200 g / liter, and particularly preferably 100 to 200 g / liter.
  • a larger apparent specific gravity makes it possible to make a high-concentration dispersion, which improves haze and agglomerates, and is preferable when preparing a dope having a high solid content concentration as in the present invention.
  • the dispersion of the matting agent can be prepared by putting the matting agent in a solvent and then applying it to a dispersing machine.
  • the disperser is preferably a medialess disperser in order to prevent foreign matter from entering.
  • the medialess disperser there are an ultrasonic type, a centrifugal type, a high pressure type, and the like.
  • a high pressure disperser is preferable.
  • the high pressure dispersion device is a device that creates special conditions such as high shear and high pressure by passing a composition in which fine particles and a solvent are mixed at high speed through a narrow tube.
  • the maximum pressure condition inside the apparatus is preferably 9.807 MPa or more in a thin tube having a tube diameter of 1 to 2000 ⁇ m.
  • high-pressure dispersing apparatus examples include an ultra-high pressure homogenizer (trade name: Microfluidizer) manufactured by Microfluidics Corporation or a nanomizer manufactured by Nanomizer, and other manton gorin type high-pressure dispersing apparatuses such as homogenizer manufactured by Izumi Food Machinery. And UHN-01 manufactured by Sanwa Machinery Co., Ltd.
  • ultra-high pressure homogenizer trade name: Microfluidizer
  • nanomizer manufactured by Nanomizer
  • UHN-01 manufactured by Sanwa Machinery Co., Ltd.
  • the cellulose ester film according to the present invention can be preferably used regardless of whether it is a film produced by a solution casting method or a film produced by a melt casting method.
  • the retardation film of the present invention is produced by dissolving a cellulose ester and an additive in a solvent to prepare a dope, casting a dope onto an endless metal support that moves infinitely It is performed by a step of drying the cast dope as a web, a step of peeling from the metal support, a step of stretching or maintaining the width, a step of further drying, and a step of winding up the finished film.
  • the concentration of cellulose ester in the dope is preferably higher because the drying load after casting on the metal support can be reduced. However, if the concentration of cellulose ester is too high, the load during filtration increases and the filtration accuracy is poor. Become.
  • the concentration that achieves both of these is preferably 10 to 35% by mass, and more preferably 15 to 25% by mass.
  • the solvent used in the dope may be used alone or in combination of two or more, but it is preferable to use a mixture of a good solvent and a poor solvent of cellulose ester in terms of production efficiency, and there are many good solvents. This is preferable from the viewpoint of the solubility of the cellulose ester.
  • a preferable range of the mixing ratio of the good solvent and the poor solvent is 70 to 98% by mass for the good solvent and 2 to 30% by mass for the poor solvent.
  • the good solvent used in the present invention is not particularly limited, and examples thereof include organic halogen compounds such as methylene chloride, dioxolanes, acetone, methyl acetate, and methyl acetoacetate. Particularly preferred is methylene chloride or methyl acetate.
  • the poor solvent used in the present invention is not particularly limited, but for example, methanol, ethanol, n-butanol, cyclohexane, cyclohexanone and the like are preferably used.
  • the dope preferably contains 0.01 to 2% by mass of water.
  • the solvent used for dissolving the cellulose ester is used by collecting the solvent removed from the film by drying in the film-forming process and reusing it.
  • the recovery solvent may contain trace amounts of additives added to the cellulose ester, such as plasticizers, UV absorbers, polymers, monomer components, etc., but even if these are included, they are preferably reused. Can be purified and reused if necessary.
  • additives added to the cellulose ester such as plasticizers, UV absorbers, polymers, monomer components, etc., but even if these are included, they are preferably reused. Can be purified and reused if necessary.
  • a general method can be used. When heating and pressurization are combined, it is possible to heat above the boiling point at normal pressure.
  • a method in which a cellulose ester is mixed with a poor solvent and wetted or swollen, and then a good solvent is added and dissolved is also preferably used.
  • Pressurization may be performed by a method of injecting an inert gas such as nitrogen gas or a method of increasing the vapor pressure of the solvent by heating. Heating is preferably performed from the outside.
  • a jacket type is preferable because temperature control is easy.
  • the heating temperature with the addition of the solvent is preferably higher from the viewpoint of the solubility of the cellulose ester, but if the heating temperature is too high, the required pressure increases and the productivity deteriorates.
  • the preferred heating temperature is 45 to 120 ° C, more preferably 60 to 110 ° C, and still more preferably 70 ° C to 105 ° C.
  • the pressure is adjusted so that the solvent does not boil at the set temperature.
  • a cooling dissolution method is also preferably used, whereby the cellulose ester can be dissolved in a solvent such as methyl acetate.
  • the cellulose ester solution is filtered using an appropriate filter medium such as filter paper.
  • an appropriate filter medium such as filter paper.
  • the filter medium it is preferable that the absolute filtration accuracy is small in order to remove insoluble matters and the like, but there is a problem that the filter medium is likely to be clogged if the absolute filtration accuracy is too small.
  • a filter medium with an absolute filtration accuracy of 0.008 mm or less is preferable, a filter medium with 0.001 to 0.008 mm is more preferable, and a filter medium with 0.003 to 0.006 mm is still more preferable.
  • the material of the filter medium there are no particular restrictions on the material of the filter medium, and ordinary filter media can be used. However, plastic filter media such as polypropylene and Teflon (registered trademark), and metal filter media such as stainless steel do not drop off fibers. preferable.
  • a bright spot foreign material is an arrangement in which two polarizing plates are placed in a crossed Nicol state, an optical film (retardation film) or the like is placed between them, and light is applied from the side of one polarizing plate. It is a point (foreign matter) that light from the opposite side appears to leak when observed from the side, and the number of bright spots having a diameter of 0.01 mm or more is preferably 200 pieces / cm 2 or less.
  • it is 100 pieces / cm 2 or less, still more preferably 50 pieces / m 2 or less, still more preferably 0 to 10 pieces / cm 2 . Further, it is preferable that the number of bright spots of 0.01 mm or less is small.
  • the dope can be filtered by a normal method, but the method of filtering while heating at a temperature not lower than the boiling point of the solvent at normal pressure and in a range where the solvent does not boil under pressure is the filtration pressure before and after filtration.
  • the increase in the difference (referred to as differential pressure) is small and preferable.
  • the preferred temperature is 45 to 120 ° C, more preferably 45 to 70 ° C, and still more preferably 45 to 55 ° C.
  • the filtration pressure is preferably 1.6 MPa or less, more preferably 1.2 MPa or less, and further preferably 1.0 MPa or less.
  • the metal support in the casting (casting) step preferably has a mirror-finished surface.
  • a stainless steel belt or a drum whose surface is plated with a casting is preferably used.
  • the cast width can be 1 ⁇ 4m.
  • the surface temperature of the metal support in the casting step is ⁇ 50 ° C. to less than the boiling point of the solvent, and a higher temperature is preferable because the web drying speed can be increased. May deteriorate.
  • the preferred support temperature is 0 to 55 ° C, more preferably 25 to 50 ° C.
  • the method for controlling the temperature of the metal support is not particularly limited, but there are a method of blowing hot air or cold air, and a method of contacting hot water with the back side of the metal support. It is preferable to use warm water because heat transfer is performed efficiently, so that the time until the temperature of the metal support becomes constant is short. When warm air is used, wind at a temperature higher than the target temperature may be used.
  • the peeling tension when peeling the film from the support is preferably 300 N / m or less.
  • the amount of residual solvent when peeling the web from the metal support is preferably 10 to 150% by mass, more preferably 20 to 40% by mass or 60 to 130% by mass. Particularly preferred is 20 to 30% by mass or 70 to 120% by mass.
  • the amount of residual solvent is defined by the following formula.
  • Residual solvent amount (% by mass) ⁇ (MN) / N ⁇ ⁇ 100 M is the mass of a sample collected during or after the production of the web or film, and N is the mass after heating M at 115 ° C. for 1 hour.
  • the web is peeled off from the metal support, and further dried, and the residual solvent amount is preferably 1% by mass or less, more preferably 0.1% by mass or less, Particularly preferred is 0 to 0.01% by mass or less.
  • a roll drying method (a method in which webs are alternately passed through a plurality of rolls arranged above and below) and a method in which the web is dried while being conveyed by a tenter method are employed.
  • the means for drying the web is not particularly limited, and can be generally performed with hot air, infrared rays, a heating roll, microwave, or the like, but is preferably performed with hot air in terms of simplicity.
  • drying temperature in the web drying process is increased stepwise from 40 to 200 ° C.
  • a film may be produced while casting and laminating the cellulose ester solutions from a plurality of casting openings provided at intervals in the traveling direction of the metal support ( (Sequential multi-layering)
  • two or more casting ports may be provided in one die, and the cellulose ester solution may be simultaneously cast to produce a multilayer structure film (simultaneous multi-layering).
  • the method for producing the successive layers include the methods described in JP-B-60-27562, JP-A-61-104413, JP-A-61-158414, JP-A-1-122419, and the like. It is done.
  • Examples of the method for producing the simultaneous multilayer include the methods described in JP-A-61-94724, JP-A-61-158413, JP-A-6-134933, and the like.
  • the film thickness of the cellulose ester film is not particularly limited, but 10 to 200 ⁇ m is used.
  • the film thickness is particularly preferably 10 to 100 ⁇ m. More preferably, it is 20 to 60 ⁇ m.
  • the cellulose ester film according to the present invention is formed with a width of 1 to 4 m, particularly preferably with a width of 1.4 to 4 m, particularly preferably 1.9 to 3 m. If it exceeds 4 m, conveyance becomes difficult.
  • the cellulose ester film has the configuration of the present invention, and the refractive index is controlled by controlling the transport tension and stretching.
  • the retardation value can be changed by lowering or increasing the tension in the longitudinal direction.
  • biaxial stretching or uniaxial stretching sequentially or simultaneously with respect to the longitudinal direction (film forming direction) of the film and the direction orthogonal to the longitudinal direction of the film, that is, the width direction.
  • the film obtained as described above is stretched 1.01 to 3.0 times in at least one direction after passing through the step of contacting the cooling roll. Stretching can improve surface quality, such as streaking, and adjust retardation.
  • a known roll stretching machine or tenter can be used.
  • a method of stretching in the vertical direction a method of stretching in the horizontal direction and stretching in the horizontal direction, a method of stretching in the vertical and horizontal directions and stretching in both the vertical and horizontal directions, and the like.
  • these methods may be used in combination.
  • a tenter it may be a pin tenter or a clip tenter.
  • the draw ratios in the biaxial directions perpendicular to each other are preferably in the range of 0.8 to 1.5 times in the casting direction and 1.1 to 2.5 times in the width direction, respectively. It is preferable to carry out in the range of 0.8 to 1.0 times in the direction and 1.2 to 2.0 times in the width direction.
  • the stretching temperature is preferably 120 ° C. to 200 ° C., more preferably 150 ° C. to 200 ° C., more preferably more than 150 ° C. and 190 ° C. or less.
  • the residual solvent in the film is preferably 20 to 0%, more preferably 15 to 0%.
  • the residual solvent is stretched by 11% at 155 ° C., or the residual solvent is stretched by 2% at 155 ° C. Alternatively, it is preferable that the residual solvent is stretched at 11% at 160 ° C, or the residual solvent is stretched at less than 1% at 160 ° C.
  • the stretching is preferably performed under a uniform temperature distribution controlled in the width direction.
  • the temperature is preferably within ⁇ 2 ° C, more preferably within ⁇ 1 ° C, and particularly preferably within ⁇ 0.5 ° C.
  • known heat setting conditions, cooling, and relaxation treatment may be performed, and adjustment can be made as appropriate so as to have characteristics required for the target film.
  • the film may be contracted in the longitudinal direction or the lateral direction.
  • the latter method can be performed by using a general simultaneous biaxial stretching machine, and by gradually and gradually narrowing the interval between adjacent clips in the longitudinal direction by driving the clip portion by, for example, a pantograph method or a linear drive method. it can. You may combine with extending
  • the dimensional change rate of the optical film (retardation film) can be reduced by shrinking 0.5% to 10% in both the longitudinal direction and the lateral direction.
  • Stretching can be performed, for example, sequentially or simultaneously in the longitudinal direction of the optical film (retardation film) and the direction orthogonal to the longitudinal direction of the optical film (retardation film), that is, the width direction.
  • the film thickness variation of the obtained optical film (retardation film) can be reduced by stretching in biaxial directions perpendicular to each other. If the film thickness variation of the optical film (retardation film) is too large, the retardation will become uneven, and unevenness such as coloring may be a problem when used in a liquid crystal display.
  • the film thickness variation of the optical film is preferably ⁇ 3%, and more preferably ⁇ 1%.
  • ⁇ 1 is preferably ⁇ 1 ° or more and + 1 ° or less, ⁇ 0 It is more preferably from 5 ° to + 0.5 °, and further preferably from ⁇ 0.1 ° to + 0.1 °.
  • This ⁇ 1 can be defined as an orientation angle, and ⁇ 1 can be measured using an automatic birefringence meter KOBRA-21ADH (Oji Scientific Instruments).
  • KOBRA-21ADH Oji Scientific Instruments
  • the in-plane retardation value (Ro) and the retardation value (Rt) in the thickness direction of the retardation film of the present invention are 30 to 100 nm when used as a polarizer protective film. And the retardation value (Rt) in the thickness direction needs to be in the range of 100 to 300 nm, but the in-plane retardation value (Ro) is in the range of 35 to 65 nm, and The retardation value (Rt) in the thickness direction is preferably in the range of 100 to 180 nm.
  • variation of Rt and the width of distribution are preferably less than ⁇ 50%, preferably less than ⁇ 30%, and preferably less than ⁇ 20%. Further, it is preferably less than ⁇ 15%, preferably less than ⁇ 10%, preferably less than ⁇ 5%, particularly preferably less than ⁇ 1%. Most preferably, there is no variation in Rt.
  • the retardation values Ro and Rt can be obtained by the following equations.
  • d is the thickness (nm) of the film
  • nx is the maximum refractive index in the plane of the film (also referred to as the refractive index in the slow axis direction)
  • ny is the refraction in the direction perpendicular to the slow axis in the film plane.
  • the rate, nz is the refractive index of the film in the thickness direction.
  • Retardation values Ro and Rt can be measured using an automatic birefringence meter. For example, it can be obtained at a wavelength of 590 nm under an environment of 23 ° C. and 55% RH using KOBRA-21ADH (Oji Scientific Instruments).
  • Tg glass transition temperature
  • the adhesiveness between the retardation film and the polarizer was the best when the stretching temperature was Tg to Tg + 20 (° C.) of the resin.
  • Tg the stretching temperature
  • Tg + 20 (° C.) of the resin the stretching temperature
  • the film was stretched at a temperature higher than Tg, the expression of retardation (retardation) was insufficient. It is better to stretch the phase difference at a temperature lower than Tg.
  • the stretching temperature is too low, it becomes difficult to stretch, so that the film becomes cloudy or breaks during stretching.
  • the film is preferably stretched at Tg-20 to Tg (° C.).
  • the retardation film has a three-layer structure, the glass transition temperature (Tgs) of the surface layer (hereinafter sometimes referred to as skin layer), and the inner layer (hereinafter referred to as core).
  • Tgs glass transition temperature
  • core inner layer
  • the draw ratio is preferably 30 to 60 (%), and more preferably 35 to 50 (%). Increasing the value improves the adhesion of the polarizer and the phase difference is good, but if the stretch ratio is too large, the film becomes cloudy or breaks during stretching.
  • the method of changing the glass transition temperature includes a method of changing the substitution degree of the cellulose ester and a method of adding additives such as a plasticizer and a resin.
  • a method of changing the substitution degree of the cellulose ester light scattering at the interface of the laminated layers, generation of bright spot foreign matters when recycled, and the like are preferable.
  • the glass transition temperature was measured at a rate of temperature increase of 20 ° C./min using a differential scanning calorimeter (DSC-7 manufactured by Perkin Elmer) and determined according to JIS K7121 (1987).
  • the end of the optical film (retardation film) is slit to a product width by a slitter and cut off, and then the knurling (embossing processing) is performed by a knurling apparatus comprising an embossing ring and a back roll.
  • Retardation film It is applied to both ends and taken up by a winder, thereby preventing sticking and scratching in the optical film (retardation film) (original winding).
  • the knurling method can process a metal ring having an uneven pattern on its side surface by heating or pressing.
  • the shortest distance between the outer peripheral surface of the cylindrically wound optical film (retardation film) and the outer peripheral surface of the mobile transport roll immediately before this is constant.
  • the optical film (retardation film) is wound on a winding roll while being held.
  • means such as a static elimination blower for removing or reducing the surface potential of the optical film (retardation film) is provided.
  • the winder related to the production of the optical film (retardation film) of the present invention may be generally used, such as a constant tension method, a constant torque method, a taper tension method, a program tension control method with a constant internal stress, etc. It can be wound up by the winding method.
  • the initial winding tension when winding the optical film (retardation film) is preferably 90.2 to 300.8 N / m.
  • the optical film (retardation film) is preferably wound under environmental conditions of a temperature of 20 to 30 ° C. and a humidity of 20 to 60% RH. If the temperature in the winding process is in the range of 20 to 30 ° C., there will be no wrinkling, and there will be no deterioration in the winding quality of the optical film (retardation film). Also, if the humidity in the winding process of the optical film (retardation film) is 20 to 60% RH, the deterioration of the optical film (retardation film) winding quality due to moisture absorption is reduced, the winding quality is excellent, and there is also a sticking failure. There is no deterioration in transportability.
  • the winding core for winding the optical film (retardation film) into a roll may be any material as long as it is a cylindrical core, but is preferably a hollow plastic core.
  • the plastic material may be any heat-resistant plastic that can withstand the heat treatment temperature, and examples thereof include phenol resins, xylene resins, melamine resins, polyester resins, and epoxy resins.
  • thermosetting resin reinforced with a filler such as glass fiber is preferable.
  • a hollow plastic core a wound core made of FRP having an outer diameter of 6 inches (hereinafter, 1 inch is 2.54 cm) and an inner diameter of 5 inches is used.
  • the roll length is preferably 10 to 5000 m, more preferably 50 to 4500 m in consideration of productivity and transportability.
  • the width of the optical film (retardation film) at this time can be selected from the width of the polarizer and the width suitable for the production line, but it is 0.5 to 4.0 m, preferably 1.0 to 3.0 m. It is preferable to produce an optical film (retardation film) with a width of 5 mm and wind it into a roll.
  • Haze value is used as an index for judging the transparency of the optical film (retardation film) in the present invention.
  • the haze value is required to be 0.5% or less, and 0.35% or less. More preferably.
  • the optical film (retardation film) of the present invention preferably has a total light transmittance of 90% or more, more preferably 92% or more. In order to achieve excellent transparency expressed by such total light transmittance, it is necessary not to introduce additives and copolymerization components that absorb visible light, or to remove foreign substances in the polymer by high-precision filtration. It is effective to reduce the diffusion and absorption of light inside the film.
  • the optical film (retardation film) of the present invention has an elongation at break in at least one direction of 30% or more, more preferably 50% or more, in the measurement based on JIS-K7127-1999.
  • the elongation at break is used as a measure of brittleness. Other measures of brittleness are known, such as tear strength and ease of cracking by bending, but the tear strength is better as the film thickness is larger, and the ease of cracking by bending is better as the film thickness is smaller.
  • the elongation at break which is not affected by the film thickness is used as an index.
  • the upper limit of the elongation at break is not particularly limited, but is practically about 250%. In order to increase the elongation at break, it is effective to suppress defects in the film caused by foreign matter and foaming.
  • the film thickness of the optical film (retardation film) of the present invention is not particularly limited, but when used for a polarizing plate protective film described later, it is preferably 20 to 200 ⁇ m, more preferably 25 to 100 ⁇ m, A thickness of 30 to 80 ⁇ m is particularly preferable.
  • stretching of the optical film (retardation film) of this invention is 1900 mm or more.
  • a functional thin film such as a hard coat layer or an antireflection layer may be provided.
  • packaging is usually performed in order to protect the product from dirt, static electricity, and the like.
  • the packaging material is not particularly limited as long as the above purpose can be achieved, but preferably does not hinder volatilization of the residual solvent from the film.
  • Specific examples include polyethylene, polyester, polypropylene, nylon, polystyrene, paper, various non-woven fabrics, and the like. Those in which the fibers are mesh cloth are more preferably used.
  • the polarizing plate using the retardation film of the present invention can be produced by a general method.
  • An adhesive layer is provided on the back side of the retardation film of the present invention, and it is preferably bonded to at least one surface of a polarizer produced by immersion and stretching in an iodine solution using a completely saponified polyvinyl alcohol aqueous solution. It is preferable.
  • the retardation film of the present invention may be used, or another polarizing plate protective film may be used.
  • cellulose ester films for example, Konica Minoltack KC8UX, KC5UX, KC8UCR3, KC8UCR4, KC8UCR5, KC8UY, KC4UY, KC4UE, KC8UE, KC8UY-HA, KC8UX-RHA, KC8UX-RHA, KC8UX KC4UXW-RHA-NC, manufactured by Konica Minolta Opto Co., Ltd.
  • cellulose ester films for example, Konica Minoltack KC8UX, KC5UX, KC8UCR3, KC8UCR4, KC8UCR5, KC8UY, KC4UY, KC4UE, KC8UE, KC8UY-HA, KC8UX-RHA, KC8UX-RHA, KC8UX KC4UXW-RHA-NC, manufactured by Konica Minolta Opto Co., Ltd.
  • the polarizing plate protective film used on the surface side of the liquid crystal display device preferably has an antireflection layer, an antistatic layer, an antifouling layer, and a backcoat layer.
  • a polarizer which is a main component of a polarizing plate, is an element that transmits only light having a plane of polarization in a certain direction.
  • a typical polarizing film known at present is a polyvinyl alcohol polarizing film, which is a polyvinyl alcohol. There are one in which iodine is dyed on a system film and one in which dichroic dye is dyed.
  • the polarizer is formed by forming a polyvinyl alcohol aqueous solution into a film and dyeing the film by uniaxial stretching or dyeing or uniaxially stretching, and then performing a durability treatment with a boron compound.
  • the film thickness of the polarizer is preferably 5 to 30 ⁇ m, particularly preferably 10 to 20 ⁇ m.
  • the ethylene unit content described in JP-A-2003-248123, JP-A-2003-342322, etc. is 1 to 4 mol%
  • the degree of polymerization is 2000 to 4000
  • the degree of saponification is 99.0 to 99.99 mol%.
  • Ethylene-modified polyvinyl alcohol is also preferably used.
  • an ethylene-modified polyvinyl alcohol film having a hot water cutting temperature of 66 to 73 ° C. is preferably used.
  • a polarizer using this ethylene-modified polyvinyl alcohol film is excellent in polarization performance and durability performance and has few color spots, and is particularly preferably used for a large liquid crystal display device.
  • a pressure-sensitive adhesive having a storage elastic modulus at 25 ° C. in the range of 1.0 ⁇ 10 4 to 1.0 ⁇ 10 9 Pa in at least a part of the pressure-sensitive adhesive layer is used. It is preferable to use a curable pressure-sensitive adhesive that forms a high molecular weight body or a crosslinked structure by various chemical reactions after the pressure-sensitive adhesive is applied and bonded.
  • urethane adhesives examples include, for example, urethane adhesives, epoxy adhesives, aqueous polymer-isocyanate adhesives, curable adhesives such as thermosetting acrylic adhesives, moisture-curing urethane adhesives, polyether methacrylate types
  • curable adhesives such as thermosetting acrylic adhesives, moisture-curing urethane adhesives, polyether methacrylate types
  • anaerobic pressure-sensitive adhesives such as ester-based methacrylate type and oxidized polyether methacrylate, cyanoacrylate-based instantaneous pressure-sensitive adhesives, and acrylate-peroxide-based two-component instantaneous pressure-sensitive adhesives.
  • the above-mentioned pressure-sensitive adhesive may be a one-component type or a type in which two or more components are mixed before use.
  • the pressure-sensitive adhesive may be a solvent system using an organic solvent as a medium, or an aqueous system such as an emulsion type, a colloidal dispersion type, or an aqueous solution type that is a medium containing water as a main component. It may be a solvent type.
  • concentration of the pressure-sensitive adhesive liquid may be appropriately determined depending on the film thickness after adhesion, the coating method, the coating conditions, and the like, and is usually 0.1 to 50% by mass.
  • polarizing plate bonded with the optical film (retardation film) of the present invention into a liquid crystal display device
  • various liquid crystal display devices with excellent visibility can be produced. It is preferably used for a liquid crystal display device for outdoor use such as digital signage.
  • the polarizing plate according to the present invention is bonded to a liquid crystal cell via the adhesive layer or the like.
  • the polarizing plate according to the present invention is a reflective type, transmissive type, transflective LCD or TN type, STN type, OCB type, HAN type, VA type (PVA type, MVA type), IPS type (including FFS type), etc. It is preferably used in LCDs of various driving methods. In particular, in a large-screen display device having a screen of 30 or more, especially 30 to 54, there is no white spot at the periphery of the screen and the effect is maintained for a long time.
  • the retardation film of the present invention has an advantage that it can be attached to a polarizer without a saponification step. Accordingly, since simple pasting can be performed, a roll of a polarizing plate can be easily manufactured. From the roll of this polarizing plate, it can be pasted on the glass cell continuously, and the productivity is improved. That is, the polarizing plate shown in claim 5, which is bonded to a glass cell that has been cut into a predetermined size on a long roll-shaped polarizing plate using an adhesive, and then cut into each glass cell.
  • the liquid crystal display device can be manufactured with high productivity by the glass panel manufacturing method characterized by the above.
  • the long roll referred to herein is one having a length of 1000 m or more, more preferably 3000 m or more.
  • Example 1 Preparation of cellulose ester CE-1> To 100 parts by mass of cellulose, 16 parts by mass of sulfuric acid, 260 parts by mass of acetic anhydride and 420 parts by mass of acetic acid were added, and the temperature was raised from room temperature to 60 ° C. over 60 minutes while stirring, and the temperature was maintained for 15 minutes. An acetylation reaction was performed. Next, a mixed solution of magnesium acetate and calcium acetate in acetic acid-water was added to neutralize the sulfuric acid, and then steam was introduced into the reaction system and maintained at 60 ° C. for 120 minutes for saponification aging treatment. Thereafter, it was washed with a large amount of water and further dried to obtain cellulose ester CE-1.
  • the total acyl substitution degree and molecular weight were determined according to the methods described above.
  • ⁇ Preparation of cellulose esters CE-2 to CE-6> Cellulose ester was similarly modified except that the production conditions of cellulose ester CE-1 were appropriately changed so that the total acyl substitution degree and propionyl substitution degree (Pr substitution degree) of the cellulose ester were changed as shown in Tables 1 to 4. Esters CE-2 to CE-6 were made. In addition, when introducing a propionyl group as a substituent, the acetylation reaction was performed using acetic acid and propionic acid.
  • ⁇ Fine particle additive solution Cellulose ester CE-1 was added to a dissolution tank containing methylene chloride and heated to completely dissolve, and this was then added to Azumi filter paper No. 3 manufactured by Azumi Filter Paper Co., Ltd. Filtered using 244. The fine particle dispersion was slowly added thereto while sufficiently stirring the filtered cellulose ester solution. Further, the particles were dispersed by an attritor so that the secondary particles had a predetermined particle size. This was filtered through Finemet NF manufactured by Nippon Seisen Co., Ltd. to prepare a fine particle additive solution.
  • ⁇ Dope liquid B> A main dope solution having the following composition was prepared.
  • the dope liquid A and the dope liquid B are arranged using a three-layer co-casting die, the dope liquid A is arranged on the surface side so that the dope liquid B is inside thereof, a belt casting apparatus is used, and a stainless steel having a width of 2 m is used. Co-cast to band support. Casting was carried out by setting the thickness of the dope liquid A to 30 ⁇ m and the thickness of the dope liquid B to 175 ⁇ m.
  • the solvent was evaporated until the residual solvent amount became 110%, and the stainless steel band support was peeled off.
  • the film was stretched so that the longitudinal (MD) stretch ratio was 1.02 by applying tension.
  • a retardation film 1-01 of the present invention having a film thickness of 40 ⁇ m having a width of 1.5 m, a knurling of 1 cm wide at the end and a height of 8 ⁇ m was produced.
  • the additive R-1 used for 1-13 and 16 is the following compound a.
  • the retardation films 1-01 to 1-18 obtained as described above were evaluated for contact angle after water treatment, polarizer adhesion, and corner unevenness as follows.
  • the contact angle after water treatment is 20 to 50 °, it can be bonded to the polarizer without performing alkali saponification treatment.
  • the angle is preferably 20 to 40 °, more preferably 20 to 30 °.
  • d is the film thickness (nm), the refractive index nx (the refractive index in the slow axis direction), ny (the refractive index in the direction perpendicular to the slow axis in the film plane), nz (the film thickness in the thickness direction). Refractive index).
  • Retardation values (Ro) and (Rt) were determined using an automatic birefringence meter KOBRA-21ADH (Oji Scientific Instruments) at 23 ° C. and 55% RH at a wavelength of 590 nm.
  • the polarizer, the retardation films 1-01 to 1-18, and Konica Minolta Op KC8UY (hereinafter referred to as 8UY) manufactured by Konica Minolta Opto Co., Ltd. are used to protect the polarizing plate according to the following steps 1 to 5. After sticking as a film and producing a polarizing plate, polarizer adhesiveness was measured.
  • Step 1 8 UY was immersed in a 2 mol / l potassium hydroxide solution at 50 ° C. for 30 seconds, then washed with water and dried to obtain a saponified cellulose ester film.
  • Step 2 The polarizer was immersed in a polyvinyl alcohol adhesive tank having a solid content of 2% by mass for 1 to 2 seconds.
  • Step 3 Gently wipe off the excess adhesive adhering to the polarizer in Step 2, and place it on the retardation film 1-01 to 1-18 and further on the back surface of 8UY processed in Step 1 did.
  • Step 4 The retardation films 1-01 to 1-18 laminated in Step 3 were bonded to the polarizer and the back side cellulose ester film at a pressure of 20 to 30 N / cm 2 and a conveying speed of about 2 m / min.
  • Step 5 A sample prepared by bonding the polarizer prepared in Step 4 with the retardation film 1-01 to 1-18 and the back side cellulose ester film in a dryer at 80 ° C. is dried for 2 minutes to prepare a polarizing plate. did.
  • the size of the polarizing plate is 5 cm ⁇ 5 cm.
  • the evaluation was performed at n 4 using four corners per sample.
  • the evaluation criteria are as follows. If it is more than ⁇ level, it is a level that is not a problem in practice. ⁇ : Not peeled off at all ⁇ ⁇ : One to two of the four corners are slightly missing (within 1 mm) ⁇ : All four corners are slightly missing (within 1 mm) ⁇ ⁇ : At least one of the four corners is peeled by about 1 cm.
  • X The retardation film is completely peeled off.
  • a liquid crystal panel for corner unevenness evaluation was produced as follows, and the characteristics as a liquid crystal display device were evaluated.
  • a polarizing plate produced by peeling off the previously bonded polarizing plates of a VA mode type liquid crystal display device (BRAVIAV1, SONY 40-inch type) in the same manner as the above-mentioned polarizer adhesion is used as a retardation film 1-. Lamination was performed on both sides so that the 01 to 1-18 side would be the glass surface of the liquid crystal cell.
  • each of the liquid crystal display devices was manufactured by performing the absorption axis in the same direction as the polarizing plate bonded in advance.
  • This liquid crystal display device is left in an environment of 40 ° C. and 90% RH for 24 hours, then the liquid crystal display device is turned on in an environment of 23 ° C. and 55%, and corner unevenness after 2 hours from lighting is observed. Evaluation was performed according to the criteria. If it is more than ⁇ level, there is no practical problem.
  • the retardation film of the present invention has an appropriate post-water treatment contact angle and retardation value as compared with the comparative example, and has excellent polarizer adhesion. It can also be seen that there is no or little corner unevenness. That is, according to the means of the present invention, it is possible to provide a retardation film that can be bonded to a polarizing plate without being subjected to a saponification treatment and has excellent corner unevenness. Moreover, the polarizing plate provided with it can be provided.
  • Example 2 Retardation films 2-01 to 2-16 were produced in the same manner as in Example 1 except that the type of cellulose ester, the amount of polymer added, and the stretching conditions were changed as shown in Tables 3 and 4.
  • the contact angle after water treatment, Ro, Rt, and polarizer adhesion were measured in the same manner as in Example 1. Further, the contrast was measured by the following method.
  • a liquid crystal display device was produced using the retardation films 2-01 to 2-16 in the same manner as the corner unevenness.
  • Contrast is 1500 or more.
  • O Contrast is 1300 or more and less than 1500.
  • ⁇ Contrast is 1000 or more and less than 1300.
  • X Contrast is less than 1000.
  • the retardation film of the present invention has an appropriate post-water treatment contact angle and retardation value relative to the comparative example, and also has polarizer adhesion and contrast. It turns out that it is excellent in. That is, according to the means of the present invention, it is possible to provide a retardation film having good contrast, which can be bonded to a polarizing plate without being subjected to saponification treatment. Moreover, the polarizing plate provided with it can be provided.
  • Example 3 Retardation films 3-01 to 3-03 were obtained in the same manner as in Example 1 except that the presence or absence of the surface layer polymer and the number of layers were changed as shown in Table 5 and the width of the retardation film was changed to 1900 mm. The film width was changed by adjusting the casting width and slit width. Further, polarizing plates 3-01 to 3-03 having a width of 1900 mm were prepared in the same manner as described in Example 1.
  • the polarizing plates 3-01 to 3-03 are cut into squares each having a size of 950 mm ⁇ 950 mm and bonded to a glass substrate using an acrylic adhesive.
  • the bonded polarizing plate is peeled off from the glass with a strength of 5 N from the corner. This operation was performed with 100 polarizing plates for one type of sample, and the number of polarizing plates that were not peeled completely due to tears in the polarizing plate was counted. Reworkability was evaluated by ranking according to the following criteria.
  • the number of polarizing plates that were not completely peeled was 0 to 10
  • the number of polarizing plates that were not completely peeled was 11 to 15
  • the reworkability of the polarizing plate is practically not problematic as long as it is at or above the level of ⁇ , but is preferably at or above the level of ⁇ .
  • the retardation film is a roll film having a width of 1900 mm and a length of 3900 m.
  • An adhesive is applied online to the long retardation film roll, and is attached to a polarizer to form a long roll of polarizing plate.
  • Manufactured It was also possible to continuously produce the polarizing plate long roll by sticking it to a glass cell previously cut to a predetermined size using an adhesive and then cutting the glass cell for each of the glass cells.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Polarising Elements (AREA)

Abstract

L'invention concerne un film de retardement qui peut être appliqué sur une plaque de polarisation sans effectuer de traitement de saponification, et qui possède un meilleur contraste et un meilleur ressuage en coin. L'invention concerne également une plaque de polarisation comprenant ce film. L'invention concerne plus précisément un film de retardement, et analogue, qui peuvent être utilisés de façon optimale dans des dispositifs d'affichage à cristaux liquides de grande taille. Le film de retardement comprend une résine d'ester de cellulose dans laquelle le niveau total de substitution acyle se situe dans une plage de 2,0 à 2,5, et se caractérise en ce qu'il est immergé dans de l'eau à un pH de 6 à 8 pendant 30 minutes à une température de 25° C, l'angle de contact entre ledit film de retardement et l'eau après séchage se situant dans une plage de 20° à 50°, la valeur de retardement en plan (Ro) dudit film de retardement à une longueur d'onde de lumière mesurée de 590 nm se situant dans une plage de 30 à 100 nm, et la valeur de retardement dans le sens de l'épaisseur (Rt) se situant dans une plage de 100 à 300 nm.
PCT/JP2011/050706 2010-03-16 2011-01-18 Film de retardement et plaque de polarisation le comprenant WO2011114764A1 (fr)

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Cited By (4)

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JP2013075401A (ja) * 2011-09-30 2013-04-25 Fujifilm Corp セルロースアシレート積層フィルムとその製造方法、偏光板および液晶表示装置
JP2013127571A (ja) * 2011-12-19 2013-06-27 Konica Minolta Advanced Layers Inc 偏光板保護フィルムおよびこれを用いた偏光板
WO2014109299A1 (fr) * 2013-01-08 2014-07-17 コニカミノルタ株式会社 Film d'acylate de cellulose, procédé de fabrication de celui-ci, plaque polarisante, et dispositif d'affichage à cristaux liquides
JP2019215472A (ja) * 2018-06-14 2019-12-19 住友化学株式会社 接着層付き積層体、積層体、液晶層積層体、液晶フィルムの製造方法、及び、光学積層体の製造方法

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JP2008015307A (ja) * 2006-07-07 2008-01-24 Nitto Denko Corp 液晶パネル及び液晶表示装置
JP2008282028A (ja) * 2004-11-16 2008-11-20 Dainippon Printing Co Ltd 位相差フィルム及びその製造方法、光学機能フィルム、偏光フィルム、並びに表示装置

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JP2006257204A (ja) * 2005-03-16 2006-09-28 Fuji Photo Film Co Ltd セルロースエステルフィルム、その製造方法、偏光板、位相差板および光学用表示装置
JP2006290929A (ja) * 2005-04-06 2006-10-26 Konica Minolta Opto Inc セルロースエステルフィルム、セルロースエステルフィルムの製造方法、偏光板及び液晶表示装置
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Publication number Priority date Publication date Assignee Title
JP2013075401A (ja) * 2011-09-30 2013-04-25 Fujifilm Corp セルロースアシレート積層フィルムとその製造方法、偏光板および液晶表示装置
JP2013127571A (ja) * 2011-12-19 2013-06-27 Konica Minolta Advanced Layers Inc 偏光板保護フィルムおよびこれを用いた偏光板
WO2014109299A1 (fr) * 2013-01-08 2014-07-17 コニカミノルタ株式会社 Film d'acylate de cellulose, procédé de fabrication de celui-ci, plaque polarisante, et dispositif d'affichage à cristaux liquides
JPWO2014109299A1 (ja) * 2013-01-08 2017-01-19 コニカミノルタ株式会社 セルロースアシレートフィルム、その製造方法、偏光板及び液晶表示装置
JP2017219863A (ja) * 2013-01-08 2017-12-14 コニカミノルタ株式会社 セルロースアシレートフィルムの製造方法
JP2019215472A (ja) * 2018-06-14 2019-12-19 住友化学株式会社 接着層付き積層体、積層体、液晶層積層体、液晶フィルムの製造方法、及び、光学積層体の製造方法
JP7122168B2 (ja) 2018-06-14 2022-08-19 住友化学株式会社 接着層付き積層体、積層体、液晶層積層体、液晶フィルムの製造方法、及び、光学積層体の製造方法

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