WO2011145495A1 - Plaque de polarisation avec film de retardement - Google Patents

Plaque de polarisation avec film de retardement Download PDF

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Publication number
WO2011145495A1
WO2011145495A1 PCT/JP2011/060831 JP2011060831W WO2011145495A1 WO 2011145495 A1 WO2011145495 A1 WO 2011145495A1 JP 2011060831 W JP2011060831 W JP 2011060831W WO 2011145495 A1 WO2011145495 A1 WO 2011145495A1
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Prior art keywords
acid
film
retardation film
polarizer
polarizing plate
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PCT/JP2011/060831
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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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Publication of WO2011145495A1 publication Critical patent/WO2011145495A1/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
    • G02B5/3025—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
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B1/00—Optical elements characterised by the material of which they are made; Optical coatings for optical elements
    • G02B1/10—Optical coatings produced by application to, or surface treatment of, optical elements
    • G02B1/14—Protective coatings, e.g. hard coatings
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B1/00—Optical elements characterised by the material of which they are made; Optical coatings for optical elements
    • G02B1/10—Optical coatings produced by application to, or surface treatment of, optical elements
    • G02B1/11—Anti-reflection coatings
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
    • G02B27/0006—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00 with means to keep optical surfaces clean, e.g. by preventing or removing dirt, stains, contamination, condensation

Definitions

  • the present invention relates to a polarizing plate with a retardation film. More specifically, the present invention relates to a polarizing plate with a retardation film that is excellent in viewing angle even under high-temperature and high-humidity conditions and has favorable cloud unevenness and corner unevenness.
  • the image display quality may deteriorate due to a decrease in viewing angle, cloud unevenness or corner unevenness. Possible causes of this include changes in retardation of the retardation film, changes in the dimensions of the polarizing plate, and deterioration in the degree of polarization of the polarizing plate due to high temperature and high humidity conditions.
  • a polarizer used for a polarizing plate is made by stretching iodine about 5 times after coordinating iodine to a polyvinyl alcohol film.
  • the polarizer expands due to water absorption under high-temperature and high-humidity conditions, or the strain is released and contracts. Due to the expansion / contraction of the polarizer, the polarizing plate undergoes a dimensional change, the retardation film is stressed to change the retardation, and the orientation of the polarizer is disturbed, so that the polarization degree of the polarizing plate is deteriorated. In addition, since iodine used in the polarizer is decolorized under high temperature and high humidity conditions, the degree of polarization may be deteriorated.
  • a polarizing plate produced by laminating a protective film having a moisture permeability of 10 (g / (m 2 ⁇ d)) uniaxially stretched on both surfaces of a polarizer having a water content of 5% or less has been proposed.
  • this method has a problem that the productivity of the polarizing plate is remarkably lowered because a fragile polarizer having a water content of 5% or less is handled.
  • the moisture content of the polarizer increases to a normal state after a long period of time since the production of the polarizing plate, but it has been found that the degree of polarization is greatly degraded when exposed to high temperatures in this state.
  • the present invention has been made in view of the above problems and situations, and the problem to be solved is a polarizing plate with a retardation film that has a good viewing angle even under high-temperature and high-humidity conditions and does not cause cloud unevenness and corner unevenness. Is to provide.
  • a polarizing plate in which a polarizer protective film having a moisture permeability of 0 to 10 g / (m 2 ⁇ d) stretched in a biaxial direction is bonded to one surface of a polarizer containing a polyvinyl alcohol resin, A polarizing plate with a retardation film, wherein a retardation film having a moisture permeability of 800 to 2000 g / (m 2 ⁇ d) is disposed on the other surface of the polarizer.
  • the difference between the elastic modulus in the longitudinal direction of the polarizer protective film and the elastic modulus in the longitudinal direction of the retardation film at 23 ° C. and 55% RH is 0 to 0.5 GPa, and the width of the polarizer protective film 2.
  • the elastic modulus in the longitudinal direction of the polarizer protective film at 40 ° C. and 90% RH is 0.5 to 1.5 GPa larger than the elastic modulus in the longitudinal direction of the retardation film, and the width of the polarizer protective film 3.
  • the moisture permeability in the present invention is measured under the condition of 40 ° C. and 90% RH according to the method specified in JIS-Z0208. Moisture permeability represents the ease of moisture penetration of the film.
  • the water vapor transmission rate is related to the influence of environmental conditions when using the polarizing plate laminating process and the liquid crystal display device.
  • a polyvinyl alcohol resin used for a polarizer is stretched at a high magnification of about 5 times for orientation, and thus has a problem that it is easily torn in a dry state. For this reason, since the direction which bonded in the polarizing plate bonding process in the state containing some water
  • a water-based adhesive is used for bonding the polarizer and the cellulose ester film. For this reason, immediately after bonding a polarizing plate, a certain amount of moisture exists between a polarizer protective film and a retardation film. The water needs to be quickly dried and evaporated to the outside of the polarizing plate.
  • the orientation of the polarizer may be disturbed and the degree of polarization may deteriorate.
  • productivity since it takes a long time to dry at a low temperature, productivity may deteriorate and moisture may remain.
  • the water vapor transmission rate of a polarizer protective film and a phase difference film is important, and the one where a water vapor transmission rate is higher is advantageous.
  • the moisture permeability of the polarizer protective film in the present invention is 0 to 10 g / (m 2 ⁇ d), preferably 0 to 6 g / (m 2 ⁇ d).
  • the water vapor permeability of the retardation film in the present invention is 800 to 2000 g / (m 2 ⁇ d), preferably 1000 to 1600 g / (m 2 ⁇ d).
  • the moisture permeability of the polarizer protective film is within this range, the entry and exit of moisture when used as a liquid crystal display device is suppressed, so the viewing angle, cloud unevenness, corner unevenness, etc. at high temperature and high humidity are improved. .
  • the moisture vapor transmission rate of the retardation film is in the above range, the moisture is easily dried at the time of polarizing plate bonding, and thus the productivity and the degree of polarization are good.
  • a film having a moisture permeability of 0 to 10 g / (m 2 ⁇ d) is used as the polarizer protective film, moisture contained in the polarizer evaporates from the end through the retardation film, so that the temperature is high. Symptoms such as viewing angle at high humidity, cloud unevenness, and corner unevenness can be alleviated.
  • the moisture permeability is too high, the amount of moisture contained in the retardation film increases, and conversely, the viewing angle, cloud unevenness, corner unevenness, etc. at high temperature and high humidity deteriorate.
  • polarizer protective film examples include polypropylene resin film, polyethylene terephthalate resin film, polycarbonate resin film, polycycloolefin resin film, etc., but moisture permeability, elastic modulus, cost, corona discharge A polypropylene resin film is preferred from the viewpoint that it can be bonded with the current water paste by treatment.
  • the polypropylene resin can be produced by a method of homopolymerizing propylene using a known polymerization catalyst or a method of copolymerizing propylene and other copolymerization monomers.
  • Examples of known polymerization catalysts include a Ti—Mg catalyst comprising a solid catalyst component containing magnesium, titanium and halogen as essential components, and a catalyst in which an organoaluminum compound and an electron donating compound are combined with a Ti—Mg catalyst.
  • the organoaluminum compound include triethylaluminum, tributylaluminum, a mixture of triethylaluminum and diethylaluminum chloride, and tetraethyldialumoxane.
  • Preferred examples of the electron donating compound include cyclohexylethyldimethoxysilane and tert-butylpropyldimethoxy. Examples thereof include silane, tert-butylethyldimethoxysilane, and dicyclopentyldimethoxysilane.
  • Polypropylene resin can be produced by a solution polymerization method, a bulk polymerization method, a gas phase polymerization method, or the like.
  • the stereoregularity of the polypropylene resin may be any of isotactic, syndiotactic, and atactic.
  • a syndiotactic or isotactic polypropylene resin is preferred from the viewpoint of heat resistance.
  • the polypropylene resin used in the present invention may be a homopolymer of propylene or a copolymer with a monomer copolymerizable with propylene.
  • propylene is preferably 80 to 99% by mass, and more preferably 90 to 97% by mass.
  • copolymer copolymerized with propylene examples include ethylene and ⁇ -olefins having 4 to 20 carbon atoms. From the viewpoint of transparency and processability as a polarizer protective film, copolymerization with ethylene is preferred.
  • the polypropylene resin used in the present invention has a melt flow rate (MFR) measured at a temperature of 230 ° C. and a load of 21.18 N in accordance with JIS K-7210, 0.1 to 200 g / 10 min, particularly 0.5. It is preferably in the range of ⁇ 50 g / 10 minutes. By setting the MFR within this range, a uniform film can be obtained without imposing a large load on the extruder.
  • MFR melt flow rate
  • a known additive may be added to the polypropylene resin as long as the effects of the present invention are not impaired.
  • the additive include an antioxidant, an ultraviolet absorber, an antistatic agent, a lubricant, a nucleating agent, an antifogging agent, and an antiblocking agent.
  • antioxidants examples include phenolic antioxidants, phosphorus antioxidants, sulfur antioxidants, hindered amine light stabilizers (HALS), and the like.
  • UV absorbers examples include benzophenone UV absorbers, benzotriazole UV absorbers, and triazine UV absorbers.
  • the antistatic agent may be either a surfactant type antistatic agent or a polymer type antistatic agent.
  • the lubricant examples include higher fatty acid amides such as erucic acid amide and oleic acid amide, higher fatty acids such as stearic acid, and salts thereof.
  • nucleating agent examples include a sorbitol nucleating agent, an organic phosphate nucleating agent, and a polymer nucleating agent such as polyvinylcycloalkane.
  • matting agents such as inorganic particles and organic particles can be used.
  • Polypropylene resin can be formed into an original film by any method.
  • an extrusion molding method from a molten resin a solvent casting method in which a resin dissolved in an organic solvent is cast on a flat plate, and the solvent is removed to form a film.
  • an extrusion molding method is preferable.
  • the polypropylene resin is melted and kneaded by rotation of a screw in an extruder and extruded from a T die into a sheet.
  • the temperature of the extruded molten sheet is preferably 180 ° C to 300 ° C. If it is 180 ° C. or lower, the thickness of the film becomes nonuniform, and if it is 300 ° C. or higher, the resin may be thermally decomposed.
  • the extruder may be a single screw extruder or a twin screw extruder.
  • L / D which is the ratio of the screw length L to the diameter D
  • the compression ratio is about 1.5 to 4, and a full flight type, barrier type, or other screw can be used.
  • a barrier type screw having an L / D of 28 to 36 and a compression ratio of 2.5 to 3.5 should be used. Is preferred.
  • the T-die used in the extruder preferably has no fine steps or scratches on the surface of the resin flow path, and the lip portion is plated or coated with a material having a low coefficient of friction with the molten polypropylene resin. It is preferable that Furthermore, it is preferable that the lip tip has a sharp edge shape polished to 0.3 mm ⁇ or less. Examples of the material having a small friction coefficient include tungsten carbide type and fluorine type special plating.
  • a gear pump via an adapter between the extruder and the T die from the viewpoint of suppressing the extrusion fluctuation of the polypropylene resin. Further, it is preferable to attach a leaf disk filter to remove foreign substances in the polypropylene resin.
  • the molten sheet extruded from the T-die is cooled and solidified by being sandwiched between a metal cooling roll and a touch roll including an elastic body that rotates in pressure contact with the circumferential direction of the metal cooling roll.
  • the touch roll may use an elastic body such as rubber, or may be one in which the surface of the elastic body roll is covered with an outer cylinder made of a metal sleeve.
  • the surface temperature of both the cooling roll and the touch roll is adjusted to a low temperature of about 0 ° C. to 30 ° C. Need to be cooled quickly. When these temperatures exceed 30 ° C., it takes time to cool and solidify the molten sheet, so that the crystal component in the polypropylene resin grows, and the resulting film is inferior in transparency.
  • the surface temperature of the roll is less than 0 ° C., condensation occurs on the surface of the metallic cooling roll, and water droplets adhere to the surface, which tends to deteriorate the appearance of the film.
  • the molten sheet sandwiched between the metal cooling roll and the touch roll is cooled and solidified by contact with the roll. And after slitting an edge part as needed, it is wound up by a winder and turns into a raw film.
  • the raw film obtained as described above is stretched biaxially.
  • a stretching method a known roll stretching machine, a tenter or the like can be used.
  • Stretching is preferably performed 1.1 to 2.0 times in both the longitudinal (film transport direction) and lateral (width direction) directions.
  • the stretching temperature is preferably Tg to Tg + 50 ° C. of the raw film, more preferably Tg to Tg + 40 ° C.
  • Tg is the glass transition temperature.
  • Stretching is preferably performed under a uniform temperature distribution 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 stretched film may be contracted in the transport direction or the width direction.
  • there is a method of contracting the optical film by temporarily clipping out the width stretching and relaxing in the longitudinal direction, or by gradually narrowing the interval between adjacent clips of the transverse stretching machine. .
  • the latter method can be performed by using a general simultaneous biaxial stretching machine and driving the clip portions in the longitudinal direction by, for example, a pantograph method or a linear drive method to smoothly and gradually narrow the clip portion. I can do it. You may combine with extending
  • Stretching can be performed sequentially or simultaneously, for example, in the longitudinal direction of the optical film and in the direction orthogonal to the longitudinal direction of the optical film, that is, in the width direction.
  • the film thickness variation of the obtained optical film can be reduced by stretching in the biaxial directions perpendicular to each other.
  • the film thickness variation of the film is preferably ⁇ 3%, more preferably ⁇ 1%.
  • a method of stretching in the biaxial directions perpendicular to each other is effective, and the stretching ratio in the biaxial directions perpendicular to each other is finally 1.0 to 2.0 times in the casting direction.
  • the width is in the range of 1.01 to 2.5 times, and the range is 1.01 to 1.5 times in the casting direction and 1.05 to 2.0 times in the width direction. preferable.
  • the retardation film according to the present invention is preferably a cellulose ester resin film.
  • the retardation film according to the present invention may be referred to as a cellulose ester film.
  • the cellulose ester resin according to the present invention preferably has a total acyl substitution degree in the range of 2.0 to 2.5, but 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., 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.
  • ⁇ Hydrolysis inhibitor> You may add a hydrolysis inhibiting agent to the retardation film which concerns on 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 according to 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.
  • the retardation film according to the present invention may contain a plasticizer as necessary.
  • a plasticizer which can be contained,
  • 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.
  • 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 (b).
  • 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 according to the present invention can also contain an ultraviolet absorber.
  • the ultraviolet absorber is intended to improve light resistance by absorbing ultraviolet rays of 400 nm or less, and in particular, the transmittance at a wavelength of 370 nm is preferably 10% or less, more preferably 5% or less, and further 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-5-271471, 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-containing retardation film according to the present invention may be a film produced by a solution casting method or a film produced by a melt casting method.
  • the production of the retardation film according to the present invention includes a step of preparing a dope by dissolving a cellulose ester and an additive in a solvent, a step of casting the dope on an endless metal support, and casting.
  • the step of drying the dope as a web, the step of peeling from the metal support, the step of stretching or maintaining the width, the step of further drying, and the step of winding the finished film are performed.
  • 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.
  • the bright spot foreign matter is arranged in a crossed Nicols state with two polarizing plates, a retardation film or the like is placed between them, light is applied from one polarizing plate side, and observation is performed from the other polarizing plate side. It is a point (foreign matter) where light from the opposite side sometimes leaks, and the number of bright spots having a diameter of 0.01 mm or more is preferably 200 / 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.
  • 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 film obtained as described above is preferably stretched 1.01 to 3.0 times in at least one direction. Stretching can improve surface quality, such as streaking, and adjust retardation.
  • a known roll stretching machine or tenter can be used.
  • 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, and further preferably 150 ° C to 190 ° C.
  • the residual solvent in the film at the time of stretching is preferably 20 to 0%, more preferably 15 to 0%.
  • the residual solvent is stretched at 155 ° C. with 2 to 11%.
  • 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 width direction for the purpose of adjusting the retardation of the retardation film produced by the above method and reducing the dimensional change rate.
  • 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 retardation film can be reduced by shrinking 0.5% to 10% in both the longitudinal direction and the width direction.
  • Stretching can be performed sequentially or simultaneously, for example, in the longitudinal direction of the retardation film and in the direction orthogonal to the longitudinal direction of the retardation film, that is, in the width direction.
  • the film thickness variation of the obtained retardation film can be reduced by stretching in the biaxial directions perpendicular to each other.
  • the film thickness variation of the retardation film is too large, the retardation becomes uneven, and unevenness such as coloring may be a problem when used in a liquid crystal display.
  • the film thickness variation of the retardation film is preferably ⁇ 3%, and more preferably ⁇ 1%.
  • the slow axis or the fast axis exists in the film plane, and ⁇ 1 is preferably ⁇ 1 ° or more and + 1 ° or less, assuming that the angle formed with the film forming direction is ⁇ 1. It is more preferably 0.5 ° or more and + 0.5 ° or less, and further preferably ⁇ 0.1 ° or more and + 0.1 ° or less.
  • 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 retardation value (Rt) in the thickness direction of the retardation film according to the present invention when used as a polarizer protective film, the in-plane retardation value (Ro) is 30 to The retardation value (Rt) in the thickness direction needs to be in the range of 100 to 300 nm, and the in-plane retardation value (Ro) is in the range of 35 to 65 nm.
  • 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 + 10% to ⁇ 10%, more preferably + 5% to ⁇ 5%, and particularly preferably + 1% to ⁇ 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 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 film After stretching, after slitting the edge of the retardation film to the product width with a slitter, the film is subjected to knurling (embossing) on both ends of the film by a knurling device consisting of an embossing ring and a back roll. Take up by.
  • the knurling prevents sticking in the wound state of the retardation film and generation of scratches.
  • the knurling method can process a metal ring having an uneven pattern on its side surface by heating or pressing.
  • the retardation film is turned into a winding roll while keeping the shortest distance between the outer peripheral surface of the cylindrical winding and the outer peripheral surface of the mobile transport roll immediately before this constant. It is to be wound up. Further, before the winding roll, means such as a static elimination blower for removing or reducing the surface potential of the retardation film is provided.
  • the winding machine relating to the production of the retardation film according to the present invention may be a commonly used winding machine such as a constant tension method, a constant torque method, a taper tension method, a program tension control method with a constant internal stress. It can be wound up by the method.
  • the initial winding tension when winding the retardation film is preferably 90 to 300 N / m.
  • the 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 wrinkles and there will be no deterioration of the retardation film winding quality. In addition, when the humidity in the winding process is 20 to 60% RH, the retardation film winding quality deterioration due to moisture absorption is reduced, the winding quality is excellent, there is no sticking failure, and there is no deterioration in transportability.
  • the winding core for winding the retardation film in a roll shape 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 retardation film at this time can be selected from the width of the polarizer and the width suitable for the production line, but the roll is 0.5 to 4.0 m, preferably 1.0 to 3.0 m. It is preferable to wind in the shape.
  • Haze value is used as an index for judging the transparency of the retardation film in the present invention.
  • liquid crystal display devices used outdoors are required to have sufficient brightness and high contrast even in a bright place. Therefore, the haze value is required to be 0.5% or less, and 0.35% or less. More preferably.
  • the retardation film according to 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 thickness of the retardation film according to the present invention is not particularly limited, but is preferably 20 to 200 ⁇ m, more preferably 25 to 100 ⁇ m, and particularly preferably 30 to 80 ⁇ m.
  • 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 with a retardation film of the present invention can be produced by a general method.
  • the retardation film and the polarizer protective film according to the present invention are preferably bonded to both sides of a polarizer produced by immersing and stretching in an iodine solution using an adhesive.
  • 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 thickness of the polarizer is preferably 2 to 30 ⁇ m, particularly preferably 5 to 20 ⁇ m.
  • ethylene-modified polyvinyl alcohol having an ethylene unit content of 1 to 4 mol%, a polymerization degree of 2000 to 4000, and a saponification degree of 99.0 to 99.99 mol% 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.
  • an ethylene-modified polyvinyl alcohol (ethylene-modified PVA) used in the present invention an ethylene-vinyl ester polymer obtained by copolymerizing ethylene and a vinyl ester monomer is saponified to convert the vinyl ester unit into a vinyl alcohol unit.
  • the vinyl ester monomers include vinyl formate, vinyl acetate, vinyl propionate, vinyl valelate, vinyl laurate, vinyl stearate, vinyl benzoate, vinyl pivalate, vinyl versatate, and the like. Of these, vinyl acetate is preferably used.
  • the ethylene unit content (ethylene copolymerization amount) in the ethylene-modified PVA is 1 to 4 mol%, preferably 1.5 to 3 mol%, more preferably 2 to 3 mol%.
  • the content of the ethylene unit is within this range, the polarization performance and durability performance are improved, and color spots are reduced, which is preferable.
  • the following monomers can be copolymerized with the vinyl ester monomer in the ethylene-modified polyvinyl alcohol.
  • the preferred range is 15 mol% or less, more preferably 5 mol% or less.
  • Examples of monomers copolymerizable with such vinyl ester monomers include olefins having 3 to 30 carbon atoms such as propylene, 1-butene and isobutene; acrylic acid and salts thereof; methyl acrylate, ethyl acrylate, Acrylic esters such as n-propyl acrylate, i-propyl acrylate, n-butyl acrylate, i-butyl acrylate, t-butyl acrylate, 2-ethylhexyl acrylate, dodecyl acrylate, octadecyl acrylate; Methacrylic acid and its salts; methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, i-propyl methacrylate, n-butyl methacrylate, i-butyl methacrylate, t-butyl methacrylate, 2-ethylhexyl meth
  • Nitriles such as vinyl chloride, vinylidene chloride, vinyl fluoride and vinylidene fluoride; allyl compounds such as allyl acetate and allyl chloride; maleic acid and its salts or esters; itaconic acid and its salts or its Esters; Vinylsilyl compounds such as vinyltrimethoxysilane; N-vinyls such as isopropenyl acetate, N-vinylformamide, N-vinylacetamide, and N-vinylpyrrolidone Amides can be mentioned.
  • the degree of polymerization of the ethylene-modified PVA constituting the polarizer is 2000 to 4000, preferably 2200 to 3500, particularly preferably 2500 to 3000, from the viewpoint of polarization performance and durability.
  • the degree of polymerization is less than 2000, the polarizing performance and durability performance of the polarizer are lowered, which is not preferable.
  • the polymerization degree is 4000 or less because color spots of the polarizer hardly occur.
  • the degree of polymerization of ethylene-modified PVA is the weight average degree of polymerization determined from GPC measurement.
  • This weight average degree of polymerization is a value obtained by performing GPC measurement at 40 ° C. using hexafluoroisopropanol (HFIP) in which 20 mmol / liter sodium trifluoroacetate is added to the mobile phase using monodispersed PMMA as a standard. is there.
  • HFIP hexafluoroisopropanol
  • the saponification degree of the ethylene-modified PVA constituting the polarizer is 99.0 to 99.99 mol%, more preferably 99.9 to 99.99 mol%, from the viewpoint of the polarization performance and durability of the polarizer. Particularly preferred is .95 to 99.99 mol%.
  • the method for producing the ethylene-modified PVA film is not particularly limited, but the casting film forming method and the melt extrusion film forming method are preferable from the viewpoint of obtaining a good ethylene-modified PVA film.
  • the obtained ethylene-modified PVA film is subjected to drying and heat treatment as necessary.
  • Examples of the solvent for dissolving ethylene-modified PVA used for producing an ethylene-modified PVA film include dimethyl sulfoxide, dimethylformamide, dimethylacetamide, N-methylpyrrolidone, ethylene glycol, glycerin, propylene glycol, diethylene glycol, and triethylene.
  • Glycol, tetraethylene glycol, trimethylolpropane, ethylenediamine, diethylenetriamine, glycerin, water and the like can be mentioned, and one or more of these can be used.
  • dimethyl sulfoxide, water, or a mixed solvent of glycerin and water is preferably used.
  • this ethylene-modified PVA solution or ethylene-modified PVA containing water may contain a plasticizer, a surfactant, a dichroic dye, or the like, if necessary.
  • a polyhydric alcohol as a plasticizer when producing an ethylene-modified PVA film.
  • the polyhydric alcohol include ethylene glycol, glycerin, propylene glycol, diethylene glycol, diglycerin, triethylene glycol, tetraethylene glycol, trimethylolpropane, etc., and one or more of these are used. can do.
  • diglycerin, ethylene glycol, and glycerin are preferably used because of the effect of improving stretchability.
  • the amount of polyhydric alcohol added is preferably 1 to 30 parts by mass, more preferably 3 to 25 parts by mass, and most preferably 5 to 20 parts by mass with respect to 100 parts by mass of ethylene-modified PVA.
  • the amount is less than 1 part by mass, the dyeability and stretchability may be lowered.
  • the amount is more than 30 parts by mass, the ethylene-modified PVA film becomes too flexible and the handleability may be lowered.
  • a surfactant When producing an ethylene-modified PVA film, it is preferable to add a surfactant.
  • the type of the surfactant is not particularly limited, but an anionic or nonionic surfactant is preferable.
  • an anionic surfactant for example, a carboxylic acid type such as potassium laurate, a sulfate type such as octyl sulfate, and a sulfonic acid type anionic surfactant such as dodecylbenzenesulfonate are preferable.
  • Nonionic surfactants include, for example, alkyl ether types such as polyoxyethylene oleyl ether, alkylphenyl ether types such as polyoxyethylene octylphenyl ether, alkyl ester types 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 oleic acid diethanolamide
  • polyoxyalkylene allyl phenyl ether etc.
  • Nonionic surfactants such as allyl phenyl ether type are preferred. These surfactants can be used alone or in combination of two or more.
  • the addition amount of the surfactant is preferably 0.01 to 1 part by mass and more preferably 0.02 to 0.5 part by mass with respect to 100 parts by mass of the ethylene-modified PVA. If the amount is less than 0.01 parts by mass, the effect of improving the film forming property and the peelability is hardly exhibited, and if the amount is more than 1 part by mass, the surfactant elutes on the surface of the ethylene-modified PVA film and causes blocking. May decrease.
  • the ethylene-modified PVA film may be dyed, uniaxially stretched, fixed, dried, and further heat-treated as necessary.
  • the order of operations of uniaxial stretching and fixing treatment There is no particular limitation on the order of operations of uniaxial stretching and fixing treatment. Moreover, you may perform uniaxial stretching twice or more.
  • Dyeing can be performed before uniaxial stretching, during uniaxial stretching, or after uniaxial stretching.
  • dyes used for dyeing iodine-potassium iodide, dichroic dyes and the like can be used alone or in a mixture of two or more.
  • Ordinary dyeing is generally performed by immersing the PVA film in a solution containing the above-mentioned dye, but the processing conditions and processing method are particularly limited, such as mixing with the PVA film to form a film. is not.
  • uniaxial stretching wet stretching or dry heat stretching can be used, using warm water such as an aqueous boric acid solution (in a solution containing the dye or in a fixing treatment bath described later) or an ethylene-modified PVA film after water absorption. Can be done in air.
  • the stretching temperature is not particularly limited, and is preferably 30 to 90 ° C. when the ethylene-modified PVA film is stretched in warm water (wet stretching), and preferably 50 to 180 ° C. when it is dry-heat stretched.
  • the stretching ratio of uniaxial stretching (the total stretching ratio in the case of multi-stage uniaxial stretching) is preferably 4 times or more, and most preferably 5 times or more from the viewpoint of the polarization performance of the polarizer.
  • the upper limit of the stretching ratio is not particularly limited, but it is preferably 8 times or less because uniform stretching is easily obtained.
  • the thickness of the stretched film is preferably 5 to 20 ⁇ m, more preferably 10 to 15 ⁇ m.
  • Fixing treatment is often performed for the purpose of strengthening the adsorption of the dye to the ethylene-modified PVA film.
  • boric acid and / or boron compounds are added to the treatment bath used for the fixing treatment.
  • the drying treatment of the obtained polarizer is preferably performed at 30 to 150 ° C., more preferably 50 to 150 ° C.
  • an adhesive used when laminating a polarizer, a retardation film, and a polarizer protective film polyvinyl alcohol resins, epoxy resins, urethane resins, cyanoacrylate resins, acrylamide resins, and the like can be used.
  • the adhesive is preferably a water-based adhesive. That is, it is preferable that the adhesive component is dissolved in water or dispersed in water. It is also preferable to use an adhesive of a type in which a solventless monomer or oligomer is reactively cured by heating or irradiation with active energy rays.
  • preferable adhesives include, for example, partially saponified polyvinyl alcohol resin and fully saponified polyvinyl alcohol resin as polyvinyl alcohol resin, and urethane resins such as Sumirez Resin 650 (30) and 675 (manufactured by Sumika Chemtex Co., Ltd.).
  • urethane resins such as Sumirez Resin 650 (30) and 675 (manufactured by Sumika Chemtex Co., Ltd.).
  • the resin include Hydran AP-20 and APX-101H (manufactured by DIC Corporation).
  • the primer layer is preferably a transparent resin layer formed from a composition containing a modified polyvinyl alcohol resin and a crosslinking agent.
  • the modified polyvinyl alcohol resin refers to a polyvinyl alcohol resin to which ionic modification such as cation modification or anion modification is added, and specifically, KL-506 (produced by Kuraray Co., Ltd.) which is a carboxyl-modified polyvinyl alcohol resin.
  • KL-506 produced by Kuraray Co., Ltd.
  • GOSEFIMER Z200 manufactured by Nippon Synthetic Chemical Industry Co., Ltd.
  • crosslinking agent used in the primer layer examples include polyamide epoxy resins, diketones such as glutaraldehyde and glyoxal, methylolated melamine resins, water-soluble metal complexes such as zirconyl nitrate and titanium chelate, and the like.
  • a polyamide epoxy resin is preferable.
  • polyamide epoxy resin for example, a polyamide polyamine obtained by reacting a polyalkylene polyamine such as diethylenetriamine or triethylenetetramine with a dicarboxylic acid such as adipic acid can be obtained by reacting with epichlorohydrin, Specific examples include Sumirez Resin 650 (30) (manufactured by Sumika Chemtex Co., Ltd.).
  • the polarizing plate is preferably provided with an adhesive layer for adhering to the glass cell.
  • an adhesive used for the adhesive layer an 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 adhesive layer is used.
  • 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 is suitably used.
  • 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 By incorporating the polarizing plate with the retardation film according to the present invention into a liquid crystal display device, various liquid crystal display devices with excellent visibility can be produced. Particularly, large liquid crystal display devices, digital signage, etc. It is preferably used for a liquid crystal display device for outdoor use.
  • 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, it is preferably used in a large-screen display device having a screen size of 30 or more, especially 30 to 54.
  • Example 1 ⁇ Preparation of polarizer protective film PF-1> Propylene-ethylene random copolymer (Sumitomo Nobrene W151, manufactured by Sumitomo Chemical Co., Ltd.) containing about 5% by mass of ethylene units is a raw film having a film thickness of 160 ⁇ m under the conditions of a melting temperature of 200 ° C. and a cooling roll temperature of 50 ° C. Single layer melt extrusion film formation was performed with a T-die.
  • the original film was provided with a primer layer by the following method.
  • the surface of the raw film was subjected to corona discharge treatment under the condition of an integrated irradiation amount of 280 W ⁇ min / m 2 .
  • the primer PVA aqueous solution prepared above was applied to the surface of the original film by a reduced pressure extrusion method to obtain an original film with a primer layer.
  • the thickness of the primer layer was 0.3 ⁇ m.
  • the obtained primer film with a primer layer is stretched twice in the film forming direction (MD direction) with a roll stretching machine, and further stretched twice in the width direction (TD direction) to form a polarizer protective film having a thickness of 40 ⁇ m.
  • PF-1 was obtained.
  • the moisture permeability of the polarizer protective film PF-1 was 4 g / (m 2 ⁇ d).
  • a polarizer protective film PF-2 was obtained in the same manner as the polarizer protective film PF-1, except that the film thickness of the original film was 120 ⁇ m, and the finished film thickness was 30 ⁇ m.
  • the water vapor transmission rate was 8 g / (m 2 ⁇ d).
  • a polarizer protective film PF-3 was obtained in the same manner as the polarizer protective film PF-1, except that the film thickness of the original film was 80 ⁇ m, and the finished film thickness was 20 ⁇ m.
  • the water vapor transmission rate was 12 g / (m 2 ⁇ d).
  • a commercially available triacetyl cellulose film (film thickness: 80 ⁇ m, manufactured by KC8UX Konica Minolta Opto Co., Ltd.) was used as the polarizer protective film PF-4.
  • the water vapor transmission rate was 380 g / (m 2 ⁇ d).
  • ⁇ 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.
  • ⁇ Fine particle additive solution Cellulose ester CE-1 was added to the dissolution tank containing methylene chloride and heated with stirring until completely dissolved, 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.
  • the dope solution A was cast on a stainless steel band support having a width of 2 m using a belt casting apparatus. At this time, casting was performed while setting the thickness of the dope solution A to 235 ⁇ 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 RF-1 according to the present invention having a film thickness of 40 ⁇ m having a width of 1.5 m, a knurling having a width of 1 cm at the end and a height of 8 ⁇ m was produced.
  • Retardation films RF-2 to RF-6 were prepared in the same manner as described above except that the addition amount of the hydrolysis inhibitor A-5 was changed so that the moisture permeability of the retardation film was as shown in Table 1. .
  • a polarizing plate was produced by laminating the polarizer protective film PF-1 on one side of the polarizer and the retardation film RF-1 on the other side.
  • Step 1 RF-1 was immersed in a 1 mol / l aqueous sodium hydroxide solution at 50 ° C. for 30 seconds, then washed with water and dried to saponify the surface.
  • Step 2 The polarizer was immersed for 2 seconds in a polyvinyl alcohol adhesive tank having a solid content of 2% by mass.
  • Step 3 Gently wipe off excess adhesive adhering to the polarizer in Step 2, and RF-1 saponified in Step 1, and PF-1 on the other side with a primer layer on the polarizer side Laminated so that
  • Step 4 RF-1, the polarizer and PF-1 laminated in Step 3 were bonded at a pressure of 20 to 30 N / cm 2 and a conveying speed of about 2 m / min to obtain a bonded film.
  • Step 5 The laminated film produced in Step 4 was dried for 1 minute in a dryer at 60 ° C. to produce Polarizing Plate 1-1.
  • polarizing plates 1-2 to 1-9 were prepared in such a manner that the polarizer protective film and the retardation film had the combinations shown in Table 1.
  • liquid crystal display devices 1-01 to 1-09 were respectively produced by making the absorption axis in the same direction as the polarizing plate bonded in advance.
  • the viewing angle of the liquid crystal display device was measured using EZ-Contrast 160D (manufactured by ELDIM). Subsequently, the liquid crystal display device was treated at 60 ° C. and 90% RH for 1000 hours, then left in an environment of 35 ° C. and 80% RH for 24 hours, and the viewing angle was measured.
  • EZ-Contrast 160D manufactured by ELDIM was used to measure the luminance in a direction tilted 60 degrees from the normal direction of the display screen of white display and black display on a liquid crystal display device, and the ratio (60 ° contrast) was observed in the field of view. It was a corner.
  • the results were evaluated according to the following criteria in four stages.
  • the viewing angle variation represents heat resistance and moisture resistance as a polarizing plate protective film and is preferably at or above the ⁇ level.
  • 60 ° contrast is 100 or more ⁇ : 60 ° contrast is 90 or more and less than 100 ⁇ : 60 ° contrast is 80 or more and less than 90 ⁇ : 60 ° contrast is less than 80
  • the polarizing plate with a retardation film of the present invention has a better viewing angle variation at high humidity than the comparative example. That is, according to the means of the present invention, it is possible to provide a liquid crystal display device that does not deteriorate in visibility even under poor high temperature and high humidity conditions that occur outdoors in summer.
  • Example 2 A liquid crystal display device 2-01 was produced in the same manner as in Example 1.
  • the polarizer protective film used was PF-1, and the retardation film was RF-1.
  • Table 2 shows the measurement results of the Dry elastic modulus and Wet elastic modulus.
  • Dry elastic modulus and Wet elastic modulus of the polarizer protective film and the retardation film were adjusted to the numerical values shown in Table 2 to prepare liquid crystal display devices 2-02 to 2-08. Adjustment of the Dry elastic modulus and Wet elastic modulus was performed by changing the stretching temperature.
  • ⁇ Dry elastic modulus> In the measurement of the Dry elastic modulus, the sample was conditioned for 24 hours in an environment of 23 ° C. and 55% RH, and the elastic modulus was measured in an environment of 23 ° C. and 55% RH according to the method described in JIS K7127. Tensilon manufactured by ORIENTEC Co., Ltd. was used as the tensile tester, the test piece was 100 mm ⁇ 10 mm, the distance between chucks was 50 mm, and the test speed was 100 mm / min. The unit is GPa.
  • ⁇ Wet elastic modulus> For measuring the wet elastic modulus, the sample was conditioned for 24 hours in an environment of 40 ° C. and 90% RH, and the elastic modulus was measured in an environment of 40 ° C. and 90% RH according to the method described in JIS K7127. Tensilon manufactured by ORIENTEC Co., Ltd. was used as the tensile tester, the test piece was 100 mm ⁇ 10 mm, the distance between chucks was 50 mm, and the test speed was 100 mm / min. The unit is GPa.
  • Cloud unevenness is uneven light leakage under high temperature and high humidity conditions of a liquid crystal display device.
  • the liquid crystal display device is left in an environment of 60 ° C. and 90% RH for 100 hours, and then the liquid crystal display device is turned on in an environment of 40 ° C. and 90%. Evaluation was made according to criteria. If it is more than ⁇ level, there is no practical problem.
  • cloud unevenness refers to light leakage that is cloudy when the liquid crystal display device is turned on under high temperature and high humidity conditions.
  • Corner unevenness refers to light leakage at the corner of a liquid crystal display device.
  • the liquid crystal display device is left in an environment of 40 ° C. and 90% RH for 24 hours, and then the liquid crystal display device is turned on in an environment of 23 ° C. and 55%. Evaluation was made according to criteria. If it is more than ⁇ level, there is no practical problem.
  • corner unevenness refers to light leakage seen at the four corners of the screen when the liquid crystal display device is turned on.
  • the polarizing plate with a retardation film of the present invention can suppress the occurrence of cloud unevenness and corner unevenness by appropriately adjusting the elastic modulus.
  • Example 3 A polarizing plate 3-01 was produced in the same manner as the polarizing plate 1-1 described in Example 1. Further, polarizing plates 3-02 to 3-07 were produced in the same manner as the polarizing plate 1-1 except that the type and film thickness of the polarizer were changed as shown in Table 3.
  • PVA in the table is a polarizer produced using a completely saponified polyvinyl alcohol resin
  • ethylene-modified PVA is a polarizer produced by the method described below.
  • ethylene-modified PVA 100 parts by mass of ethylene-modified polyvinyl alcohol having an ethylene unit content of 2.1 mol%, a saponification degree of 99.92 mol% and a polymerization degree of 3000 is impregnated with 10 parts by mass of glycerin and 200 parts by mass of water, and this is melt-kneaded. After defoaming, it was melt extruded from a T die onto a metal roll and dried to obtain an ethylene-modified polyvinyl alcohol film.
  • the thus obtained ethylene-modified polyvinyl alcohol film was successively treated in the order of pre-swelling, dyeing, uniaxial stretching, fixing treatment, drying, and heat treatment to produce a polarizer. That is, the ethylene-modified polyvinyl alcohol film is immersed in water at 30 ° C. for 60 seconds to be pre-swelled, and in a 35 ° C. aqueous solution having a boric acid concentration of 40 g / liter, an iodine concentration of 0.4 g / liter, and a potassium iodide concentration of 60 g / liter. Soaked for 2 minutes. Subsequently, it was uniaxially stretched 6 times in an aqueous solution at 55 ° C.
  • the polarizing plate obtained by the above method was cut into a square of 500 mm, stored for 120 hours in a high-temperature and high-humidity atmosphere at 60 ° C. and 90% RH, then crossed Nicol on a light box, and the polarization degree unevenness was visually evaluated.
  • the evaluation is ranked according to the following criteria and is preferably at or above the ⁇ level.
  • the polarizing plate with the retardation film of the present invention can suppress the deterioration of the polarization degree under high temperature and high humidity conditions by appropriately selecting the polarizer.

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  • Polarising Elements (AREA)

Abstract

L'invention porte sur une plaque de polarisation avec un film de retardement, laquelle plaque a un bon angle de vision sous des conditions de haute température et d'humidité élevée, tout en étant exempte de l'apparition d'une irrégularité de buée et d'une irrégularité de coin. Il est décrit de façon spécifique une plaque de polarisation avec un film de retardement, laquelle plaque est obtenue par collage d'un film protecteur polarisant étiré de façon biaxiale qui a une perméabilité à la vapeur d'eau de 0 à 10 g/(m2∙d) à une surface d'un polariseur qui contient une résine de poly(alcool vinylique). La plaque de polarisation avec un film de retardement est caractérisée en ce qu'un film de retardement, qui a une perméabilité à la vapeur d'eau de 800 à 2000 g/(m2∙d), est disposée sur l'autre surface du polariseur.
PCT/JP2011/060831 2010-05-20 2011-05-11 Plaque de polarisation avec film de retardement WO2011145495A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2010116037 2010-05-20
JP2010-116037 2010-05-20

Publications (1)

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WO2011145495A1 true WO2011145495A1 (fr) 2011-11-24

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WO (1) WO2011145495A1 (fr)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2012133880A1 (fr) * 2011-03-31 2012-10-04 住友化学株式会社 Plaque de polarisation
WO2013111735A1 (fr) * 2012-01-25 2013-08-01 コニカミノルタアドバンストレイヤー株式会社 Film optique
CN104508521A (zh) * 2012-07-27 2015-04-08 富士胶片株式会社 偏光板及液晶显示装置
JPWO2014057949A1 (ja) * 2012-10-12 2016-09-05 富士フイルム株式会社 液晶表示装置

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JP2005128520A (ja) * 2003-09-29 2005-05-19 Fuji Photo Film Co Ltd 偏光板およびそれを用いた液晶表示装置
JP2005309394A (ja) * 2004-03-25 2005-11-04 Nitto Denko Corp 偏光板の製造方法、偏光板およびそれを用いた画像表示装置
JP2006267272A (ja) * 2005-03-22 2006-10-05 Fuji Photo Film Co Ltd 画像表示装置
JP2008216416A (ja) * 2007-03-01 2008-09-18 Sumitomo Chemical Co Ltd 位相差フィルム、複合偏光板及びそれを用いた液晶表示装置

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2005128520A (ja) * 2003-09-29 2005-05-19 Fuji Photo Film Co Ltd 偏光板およびそれを用いた液晶表示装置
JP2005309394A (ja) * 2004-03-25 2005-11-04 Nitto Denko Corp 偏光板の製造方法、偏光板およびそれを用いた画像表示装置
JP2006267272A (ja) * 2005-03-22 2006-10-05 Fuji Photo Film Co Ltd 画像表示装置
JP2008216416A (ja) * 2007-03-01 2008-09-18 Sumitomo Chemical Co Ltd 位相差フィルム、複合偏光板及びそれを用いた液晶表示装置

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2012133880A1 (fr) * 2011-03-31 2012-10-04 住友化学株式会社 Plaque de polarisation
JP2012212080A (ja) * 2011-03-31 2012-11-01 Sumitomo Chemical Co Ltd 偏光板
WO2013111735A1 (fr) * 2012-01-25 2013-08-01 コニカミノルタアドバンストレイヤー株式会社 Film optique
CN104185802A (zh) * 2012-01-25 2014-12-03 柯尼卡美能达株式会社 光学膜
JPWO2013111735A1 (ja) * 2012-01-25 2015-05-11 コニカミノルタ株式会社 光学フィルム
CN104508521A (zh) * 2012-07-27 2015-04-08 富士胶片株式会社 偏光板及液晶显示装置
JPWO2014057949A1 (ja) * 2012-10-12 2016-09-05 富士フイルム株式会社 液晶表示装置
JP2017083858A (ja) * 2012-10-12 2017-05-18 富士フイルム株式会社 液晶表示装置
US9946110B2 (en) 2012-10-12 2018-04-17 Fujifilm Corporation Liquid crystal display

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