JP2008225281A - Optical film, and polarizing plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical film and a polarizing plate excellent in durability,. <P>SOLUTION: The optical film has a support, an alignment layer and an optical anisotropic layer formed by hardening a polymerizable liquid crystal composition and is characterized in that the alignment film contains at least one kind of a macromolecule whose average degree of polymerization is 800-5,000 and having a hydroxyl group. The polarizing plate has the optical film and a polarizing film. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an optical film and a polarizing plate used for a liquid crystal display device and the like.

  Various optical films prepared by utilizing the orientation of a liquid crystal composition have been proposed as optical compensation films and the like used for liquid crystal display devices. This optical film is produced, for example, by applying a polymerizable liquid crystal composition to the alignment film surface to obtain a desired alignment state, and then fixing the state by polymerization. However, some of these optical films have insufficient adhesion between the optically anisotropic layer and the alignment film, and peeling occurs when used for a long period of time. Yes.

For example, in Patent Document 1, as an optical compensation sheet having excellent durability, an optical compensation sheet in which a transparent support, an alignment film made of a polymer, and an optical anisotropic layer made of a liquid crystal compound are provided in this order, There has been proposed an optical compensation sheet characterized in that the polymer of the alignment film and the liquid crystal compound of the optically anisotropic layer are chemically bonded through the interface between these layers.
Patent Documents 2 and 3 propose that a boronic acid compound is added to a liquid crystal composition as a retardation film in which rod-like liquid crystal compounds and discotic liquid crystal molecules are vertically aligned uniformly without defects. In the examples, it is shown that the adhesion between the alignment film and the optically anisotropic layer was good.
However, further improvements in durability are required for optical films and the like used in liquid crystal display devices.
JP 09-152509 A JP 2006-215093 A JP 2006-215092 A

  This invention makes it a subject to provide the optical film and polarizing plate excellent in durability.

[1] An optical film having an optically anisotropic layer formed by curing a support, an alignment film, and a polymerizable liquid crystal composition, wherein the alignment film has an average degree of polymerization of 800 to 5000 and a hydroxyl group. An optical film comprising at least one kind of a polymer having the same.
[2] The optical film according to [1], wherein the optically anisotropic layer contains at least one boronic acid compound having a group capable of bonding to a (meth) acryl group.
[3] The optical film of [1] or [2], wherein the polymer is polyvinyl alcohol having no modifying group.
[4] The optical film according to any one of [1] to [3], wherein the average degree of polymerization of the polymer is 1200 to 5000.
[5] The optical film according to any one of [1] to [4], wherein the saponification degree of the polymer is 85% or more.
[6] The optical film according to any one of [1] to [4], wherein the saponification degree of the polymer is 95% or more.

[7] The optical film according to any one of [1] to [6], wherein the polymerizable liquid crystal composition contains at least one discotic liquid crystal compound.
[8] The optical film according to any one of [1] to [6], wherein the polymerizable liquid crystal composition contains at least one rod-like liquid crystal compound.
[9] The optical film according to any one of [1] to [8], wherein the surface of the support that is in contact with the alignment film is hydrophilized.
[10] The optical film according to [9], wherein the optical film is hydrophilized by applying a liquid containing at least an organic solvent, a metal hydroxide salt, water, a compatibilizer, and a surfactant to the surface.
[11] The optical film according to any one of [1] to [10], wherein the support includes a cellulosic polymer.
[12] A polarizing plate comprising the optical film according to any one of [1] to [11], a polarizing film, and a protective film.
[13] The polarizing plate according to [12], wherein the protective film contains a polyolefin.
[14] The polarizing plate according to [12], wherein the protective film contains polynorbornene.

  ADVANTAGE OF THE INVENTION According to this invention, the optical film and polarizing plate excellent in durability useful as members, such as a liquid crystal display device, can be provided.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the present invention will be described in detail. In the present specification, a numerical range represented by using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value.
[Optical film]
The present invention relates to an optical film having a support, an alignment film containing at least one polymer, and an optically anisotropic layer formed by curing a polymerizable liquid crystal composition.

(Alignment film)
The alignment film used in the optical film of the present invention has an average degree of polymerization of 800 to 5000 and contains at least one polymer having a hydroxyl group (hereinafter sometimes referred to as “alignment film polymer”). In the present invention, durability (especially abrasion resistance in a wet state) is improved by using the predetermined polymer for the alignment film. The alignment film polymer is preferably polyvinyl alcohol. The hydroxyl group in polyvinyl alcohol may be partially modified, but it is preferable to use unmodified polyvinyl alcohol that does not contain a modifying group. In addition, the polyvinyl alcohol used as the alignment film polymer has a saponification degree of preferably 85% or more, more preferably 95% or more, from the viewpoint of further improving durability.

  In the present invention, it is preferable to use unmodified polyvinyl alcohol having an average degree of polymerization of 800 to 5000 as the alignment film polymer. It is more preferable to use unmodified polyvinyl alcohol having an average degree of polymerization of 1200 to 5000, and it is more preferable to use unmodified polyvinyl alcohol having an average degree of polymerization of 1700 to 5000.

  Commercially available polyvinyl alcohol may be used as the alignment film polymer. Examples of unmodified polyvinyl alcohol having a polymerization degree in the above range include PVA117, PVA124, PVA135, PVA217 manufactured by Kuraray Co., Ltd., JF17, JP25, JP18 manufactured by Nihon Vinegar Bipoval, etc. Can be used.

  Further, the alignment film may contain a polymer having a polymerization degree outside the above range within a range not impairing the effects of the present invention, or may contain a polymer having no hydroxyl group. Good. However, it is preferable to contain a polymer having a hydroxyl group with a polymerization degree in the above range (preferably unmodified polyvinyl alcohol) as a main component, specifically, the total height contained in the composition for forming an alignment film. The content of the polymer having a hydroxyl group having a polymerization degree in the above-mentioned range with respect to the total mass of the molecule is preferably 50% by mass or more, more preferably 70% by mass or more, and 80% by mass or more. More preferably.

  Examples of polymers other than polyvinyl alcohol that can be optionally added to the alignment film include, for example, methacrylate polymers, styrene polymers, polyolefins described in paragraph No. [0022] of JP-A-8-338913. Poly (N-methylolacrylamide), polyester, polyimide, vinyl acetate polymer, carboxymethylcellulose, polycarbonate, gelatin, silane coupling agent and the like are included.

  Further, modified polyvinyl alcohol may be added to the alignment film as desired. The modifying group of the modified polyvinyl alcohol can be introduced by copolymerization modification, chain transfer modification or block polymerization modification. Examples of modifying groups include hydrophilic groups (carboxylic acid groups, sulfonic acid groups, phosphonic acid groups, amino groups, ammonium groups, amide groups, thiol groups, etc.), hydrocarbon groups having 10 to 100 carbon atoms, fluorine atoms Substituted hydrocarbon groups, thioether groups, polymerizable groups (unsaturated polymerizable groups, epoxy groups, azirinidyl groups, etc.), alkoxysilyl groups (trialkoxy, dialkoxy, monoalkoxy) and the like can be mentioned. Specific examples of these modified polyvinyl alcohol compounds include those described in paragraph numbers [0022] to [0145] of JP-A No. 2000-155216 and paragraph numbers [0018] to [0022] of JP-A No. 2002-62426, for example. Etc.

  Further, a polymer having a crosslinkable functional group may be added to the alignment film as desired. The crosslinkable functional group preferably contains a polymerizable group in the same manner as the polyfunctional monomer. Specific examples include those described in paragraphs [0080] to [0100] of JP-A No. 2000-155216.

The alignment film polymer having a hydroxyl group can be cross-linked using a cross-linking agent separately from the cross-linkable functional group.
Examples of the crosslinking agent include aldehydes, N-methylol compounds, dioxane derivatives, compounds that act by activating carboxyl groups, active vinyl compounds, active halogen compounds, isoxazole and dialdehyde starch. Two or more kinds of crosslinking agents may be used in combination. Specific examples include compounds described in paragraphs [0023] to [0024] in JP-A-2002-62426. Aldehydes having high reaction activity, particularly glutaraldehyde are preferred.

  0.1-20 mass% is preferable with respect to the said alignment film polymer, and, as for the addition amount of the said crosslinking agent, 0.5-15 mass% is further more preferable. The amount of the unreacted crosslinking agent remaining in the alignment film is preferably 1.0% by mass or less, and more preferably 0.5% by mass or less. By adjusting in this way, even if the alignment film is used in a liquid crystal display device for a long period of time or left in a high temperature and high humidity atmosphere for a long period of time, sufficient durability without occurrence of reticulation can be obtained.

Method for forming alignment film The alignment film is basically formed from a composition containing a polymer having a predetermined degree of polymerization having a hydroxyl group as a material for forming an alignment film, a crosslinking agent added if desired, and the like. it can. The composition is preferably prepared as a coating solution. The composition prepared as a coating solution can be formed by coating the surface of a support and then drying by heating (crosslinking). As described above, the crosslinking reaction can be carried out at any time after coating on the transparent support. When a water-soluble polymer such as polyvinyl alcohol is used as the alignment film forming material, the coating solution is preferably a mixed solvent of an organic solvent (eg, methanol) having a defoaming action and water. The ratio by mass is water: methanol greater than 0 and 99 or less: less than 100, preferably 1 or more, and more preferably greater than 0 and 91 or less: less than 100, 9 or more. Thereby, generation | occurrence | production of a bubble is suppressed and the defect of the layer surface of an orientation film and also an optically anisotropic layer reduces remarkably.

  The alignment film forming composition is preferably applied by spin coating, dip coating, curtain coating, extrusion coating, rod coating, roll coating, or the like. In particular, the rod coating method or the extrusion coating method is preferable. Although there is no restriction | limiting in particular about an application quantity, It is preferable to set it as the application quantity from which the film thickness after drying of alignment film becomes about 0.1-10 micrometers.

  After coating, the coating is dried to remove the solvent in the coating solution to form a film. You may heat as needed at the time of drying. Drying is preferably performed at 20 ° C to 110 ° C. In order to form sufficient cross-linking, 60 ° C to 100 ° C is preferable, and 80 ° C to 100 ° C is particularly preferable. The drying time is preferably 1 minute to 36 hours, more preferably 1 minute to 30 minutes. The pH is also preferably set to an optimum value for the cross-linking agent to be used, and when glutaraldehyde is used, the pH is preferably 2.5 to 5.5.

  The surface of the formed film may be rubbed if desired. For the rubbing treatment, a treatment method widely adopted as a liquid crystal alignment treatment process of LCD can be applied. That is, a method of obtaining the orientation by rubbing the surface of the orientation film in a certain direction using paper, gauze, felt, rubber, nylon, polyester fiber or the like can be used. Generally, it is carried out by rubbing using a cloth in which fibers having a uniform length and thickness are flocked on average.

(Optically anisotropic layer)
The optically anisotropic layer is formed from a polymerizable liquid crystal composition. The composition preferably contains at least one compound capable of bonding to a (meth) acrylic group (used to include both a methacrylic group and an acrylic group). It is preferable that the optically anisotropic layer contains the compound because adhesion in a dry state is improved and durability is further improved.
-Compound capable of binding to (meth) acrylic group The compound capable of binding to the (meth) acrylic group used in the present invention has a functional group capable of binding to the (meth) acrylic group. Examples of the functional group include polymerizable groups such as vinyl group, acrylate group, methacrylate group, acrylamide group, styryl group, vinyl ketone group, butadiene group, vinyl ether group, oxiranyl group, aziridinyl group, oxetane group and the like. Among these, a vinyl group, an acrylate group, a methacrylate group, a styryl group, an oxiranyl group, or an oxetane group is preferable, and a vinyl group, an acrylate group, an acrylamide group, or a styryl group is more preferable.

The compound may be any compound as long as it has the functional group described above. Above all, when a boric acid compound having the functional group is used, the adhesion between the alignment film and the optically anisotropic layer is improved. This is preferable because the orientation of the liquid crystal molecules at the alignment film interface can be controlled more. In the present specification, the term “boric acid compound” is used to mean not only a compound having at least one boronic acid group but also a compound having a boronic acid ester group. In this specification, a metal complex using these as a ligand and a boronium ion having a tetracoordinate boron atom are also included.
The boronic acid compound is preferably selected from compounds represented by the following general formula (I).

In general formula (I), R ¹ and R ² each independently represents a hydrogen atom, a substituted or unsubstituted aliphatic hydrocarbon group, an aryl group, or a heterocyclic group. Examples of the aliphatic hydrocarbon group include a substituted or unsubstituted linear or branched alkyl group having 1 to 20 carbon atoms (for example, a methyl group, an ethyl group, an iso-propyl group, etc.), Examples thereof include an unsubstituted cyclic alkyl group (for example, cyclohexyl group) and an alkenyl group having 2 to 20 carbon atoms (for example, a vinyl group). As the aryl group, substituted or unsubstituted phenyl having 6 to 20 carbon atoms. A group (for example, phenyl group, tolyl group, etc.), a substituted or unsubstituted naphthyl group having 10 to 20 carbon atoms, and the like. Examples of the heterocyclic group include at least one hetero atom (for example, nitrogen atom, oxygen atom). A substituted or unsubstituted 5- or 6-membered ring group containing, for example, a pyridyl group, an imidazolyl group, a furyl group, a piperidyl group, Ruhorino group, and the like. These may be connected to each other to form a ring. For example, the isopropyl groups of R ¹ and R ² are connected to form a 4,4,5,5-tetramethyl-1,3,2-dioxaborolane ring. You may do it.

In general formula (I), R ¹ and R ² are preferably a hydrogen atom or a linear or branched alkyl group having 1 to 3 carbon atoms, and a case where they are linked to form a ring, Most preferably, it is a hydrogen atom.

In general formula (I), R ³ represents a substituent containing a functional group that can be bonded to a (meth) acryl group. Examples of the functional group that can be bonded to the (meth) acryl group are as described above, and the preferred range is also the same. R ³ is preferably a substituted or unsubstituted aliphatic hydrocarbon group, aryl group or heterocyclic group having a functional group capable of bonding to a (meth) acryl group. Examples of the aliphatic hydrocarbon group include substituted or unsubstituted linear or branched alkyl groups having 1 to 30 carbon atoms (for example, methyl group, ethyl group, iso-propyl group, n-propyl group, butyl group, pentyl group). Group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, hexadecyl group, octadecyl group, eicosyl group, isopropyl group, isobutyl group, sec-butyl group, tert-butyl group , Isopentyl group, neopentyl group, 1-methylbutyl group, isohexyl group, 2-methylhexyl group, etc.), substituted or unsubstituted cyclic alkyl group having 3 to 20 carbon atoms (for example, cyclopentyl group, cyclohexyl group, 1-adamantyl group) , 2-norbornyl group, etc.), alkenyl groups having 2 to 20 carbon atoms (for example, Group, bi-propenyl group, 1-butenyl group, 1-methyl-1-propenyl group and the like. As the aryl group, a substituted or unsubstituted phenyl group having 6 to 50 carbon atoms (for example, phenyl Group, tolyl group, styryl group, 4-benzoyloxyphenyl group, 4-phenoxycarbonylphenyl group, 4-biphenyl group, 4- (4-octyloxybenzoyloxy) phenoxycarbonylphenyl group, etc.), having 10 to 50 carbon atoms Examples thereof include substituted or unsubstituted naphthyl groups (for example, unsubstituted naphthyl groups), and examples of the heterocyclic group include substitutions containing at least one hetero atom (for example, nitrogen atom, oxygen atom, sulfur atom, etc.). Or an unsubstituted 5- or 6-membered ring group such as pyrrole, furan, thiophene, pyrazole, imidazole , Triazole, oxazole, isoxazole, oxadiazole, thiazole, thiadiazole, indole, carbazole, benzofuran, dibenzofuran, thianaphthene, dibenzothiophene, indazolebenzimidazole, anthranyl, benzisoxazole, benzoxazole, benzothiazole, purine, pyridine, pyridazine , Pyrimidine, pyrazine, triazine, quinoline, acridine, isoquinoline, phthalazine, quinazoline, quinoxaline, naphthyridine, phenanthroline, pteridine, morpholine, piperidine and the like.

Furthermore, these aliphatic hydrocarbon groups, aryl groups, and hydrocarbon groups included in the heterocyclic group may have one or more other substitutions together with a functional group that can be bonded to the (meth) acryl group. Good. Examples of other substituents include monovalent non-metallic atomic groups excluding hydrogen, halogen atoms (—F, —Br, —Cl, —I), hydroxyl groups, alkoxy groups, aryloxy groups, mercapto groups. , Alkylthio group, arylthio group, alkyldithio group, aryldithio group, amino group, N-alkylamino group, N, N-dialkylamino group, N-arylamino group, N, N-diarylamino group, N-alkyl- N-arylamino group, acyloxy group, carbamoyloxy group, N-alkylcarbamoyloxy group, N-arylcarbamoyloxy group, N, N-dialkylcarbamoyloxy group, N, N-diarylcarbamoyloxy group, N-alkyl-N -Arylcarbamoyloxy group, alkylsulfoxy group, arylsulfoxy group, Ruthio group, acylamino group, N-alkylacylamino group, N-arylacylamino group, ureido group, N′-alkylureido group, N ′, N′-dialkylureido group, N′-arylureido group, N ′, N′-diarylureido group, N′-alkyl-N′-arylureido group, N-alkylureido group, N-arylureido group, N′-alkyl-N-alkylureido group, N′-alkyl-N-aryl Ureido group, N ′, N′-dialkyl-N-alkylureido group, N ′, N′-dialkyl-N-arylureido group, N′-aryl-N-alkylureido group, N′-aryl-N-aryl Ureido group, N ′, N′-diaryl-N-alkylureido group, N ′, N′-diaryl-N-arylureido group, N′-alkyl-N′-aryl-N-a Kilureido group, N′-alkyl-N′-aryl-N-arylureido group, alkoxycarbonylamino group, aryloxycarbonylamino group, N-alkyl-N-alkoxycarbonylamino group, N-alkyl-N-aryloxycarbonyl Amino group, N-aryl-N-alkoxycarbonylamino group, N-aryl-N-aryloxycarbonylamino group, formyl group, acyl group, carboxyl group and its conjugate base group, alkoxycarbonyl group, aryloxycarbonyl group, carbamoyl Group, N-alkylcarbamoyl group, N, N-dialkylcarbamoyl group, N-arylcarbamoyl group, N, N-diarylcarbamoyl group, N-alkyl-N-arylcarbamoyl group, alkylsulfinyl group, arylsulfinyl group, a Alkylsulfonyl group, arylsulfonyl group, sulfo group (—SO ₃ H) and its conjugate base group, alkoxysulfonyl group, aryloxysulfonyl group, sulfinamoyl group, N-alkylsulfinamoyl group, N, N-dialkylsulfinamoyl Group, N-arylsulfinamoyl group, N, N-diarylsulfinamoyl group, N-alkyl-N-arylsulfinamoyl group, sulfamoyl group, N-alkylsulfamoyl group, N, N-dialkylsulfa Moyl group, N-arylsulfamoyl group, N, N-diarylsulfamoyl group, N-alkyl-N-arylsulfamoyl group, N-acylsulfamoyl group and its conjugate base group, N-alkylsulfonyl a sulfamoyl group _{(-SO 2 NHSO 2 (alkyl)} ) and its conjugate Originally, N- aryl sulfonylsulfamoyl group _{(-SO 2 NHSO 2 (aryl)} ) and its conjugated base group, N- alkylsulfonylcarbamoyl group (-CONHSO ₂ (alkyl)) and its conjugated base group, N- aryl Sulfonylcarbamoyl group (—CONHSO ₂ (aryl)) and its conjugate base group, alkoxysilyl group (—Si (Oalkyl) ₃ ), aryloxysilyl group (—Si (Oaryl) ₃ ), hydroxysilyl group (—Si (OH) ₃ ) and its conjugate base group, phosphono group (—PO ₃ H ₂ ) and its conjugate base group, dialkylphosphono group (—PO ₃ (alkyl) ₂ ), diarylphosphono group (—PO ₃ (aryl) ₂ ), alkyl aryl phosphono group (-PO ₃ (alkyl) (aryl)), monoalkyl phosphono group ( PO ₃ H (alkyl)) and its conjugated base group, monoaryl phosphono group (-PO ₃ H (aryl)) and its conjugated base group, a phosphonooxy group (-OPO ₃ H ₂₎ and its conjugated base group, a dialkyl phosphonate Nooxy group (—OPO ₃ (alkyl) ₂ ), diarylphosphonooxy group (—OPO ₃ (aryl) ₂ ), alkylarylphosphonooxy group (—OPO ₃ (alkyl) (aryl)), monoalkylphosphono An oxy group (—OPO ₃ H (alkyl)) and its conjugate base group, a monoarylphosphonooxy group (—OPO ₃ H (aryl)) and its conjugate base group, a cyano group, a nitro group, an aryl group, an alkenyl group, An alkynyl group is mentioned. Further, these substituents may combine with each other or with a substituted hydrocarbon group to form a ring, if possible.

R ³ in the general formula (I) preferably contains an aryl group having 6 to 40 carbon atoms, more preferably a phenyl group, depending on the functional group that can be bonded to the (meth) acryl group. Even more preferably, it contains a substituted phenyl group.

  Although the specific example of a compound represented by general formula (I) below is shown, the compound used for this invention is not limited to these. In the following specific examples, boronic acid compounds that do not contain a functional group capable of binding to a (meth) acryl group, such as I-12, I-27, and I-30, are also exemplified. These are specific examples of boronic acid compounds that can be used in combination as desired.

  The boronic acid compound represented by the general formula (1) is generally a general synthesis such as esterification, amidation, alkylation using a commercially available boronic acid compound as it is or using a boronic acid compound having a substituent as a raw material. It can be easily synthesized by reaction. When a commercially available boronic acid compound is not used, for example, it is synthesized from a halide (for example, aryl bromide) by n-butyllithium and trialkoxyborane (for example, trimethoxyborane), or metal magnesium is used. It can be synthesized by applying a Wittig reaction.

  The preferred range of the content of the compound (preferably boronic acid compound) capable of reacting with the (meth) acryl group in the polymerizable liquid crystal composition is the composition (solid content excluding the solvent in the case of a coating solution). Among these, 0.005 to 8% by mass is preferable, 0.01 to 5% by mass is more preferable, and 0.05 to 1% by mass is even more preferable.

-Liquid crystal compound The polymerizable liquid crystal composition used for forming the optically anisotropic layer contains at least one liquid crystal compound. The liquid crystal compound is preferably a polymerizable liquid crystal compound having a polymerizable group. Liquid crystal compounds are generally classified into rod-like liquid crystal compounds and discotic liquid crystal compounds based on their molecular shapes. In the present invention, any liquid crystal compound may be used.
-Rod-like liquid crystal compounds As rod-like liquid crystal compounds, azomethines, azoxys, cyanobiphenyls, cyanophenyl esters, benzoic acid esters, cyclohexanecarboxylic acid phenyl esters, cyanophenylcyclohexanes, cyano-substituted phenylpyrimidines, alkoxy-substituted compounds Phenylpyrimidines, phenyldioxanes, tolanes and alkenylcyclohexylbenzonitriles are preferably used. In addition to the low-molecular liquid crystals as described above, polymer liquid crystals can also be used. As the rod-like liquid crystal compound, those having a partial structure capable of causing polymerization or crosslinking reaction by actinic rays, electron beams, heat, or the like are suitably used. The number of the partial structures is 1 to 6, preferably 1 to 3. As described above, the rod-like liquid crystalline molecules that can be used in the present invention preferably have a polymerizable group in order to fix the alignment state. The polymerizable group is preferably a radically polymerizable unsaturated group, and specific examples thereof include a polymerizable group and a polymerizable liquid crystal compound described in JP-T-2000-514202 or JP-A-2002-62427. There is no restriction | limiting in particular about the orientation form of the rod-shaped liquid crystalline molecule in the said optically anisotropic layer. The orientation may be any of vertical, horizontal, and hybrid with respect to the layer surface.

  As described above, it is more preferable to fix the alignment of the rod-like liquid crystalline molecules by polymerization. Chem. 190, 2255 (1989), Advanced Materials 5, 107 (1993), U.S. Pat. Nos. 4,683,327, 5,622,648, 5,770,107, WO 95/22586, 95/24455, 97/97. No. 0600, No. 98/23580, No. 98/52905, JP-A-1-272551, JP-A-6-16616, JP-A-7-110469, JP-A-11-80081, and Japanese Patent Application No. 2001-64627 These compounds can be used. More preferably, it is a compound represented by the following general formula (II).

^{(IV) Q 1 -L 1 -Cy} 1 -L 2 - (Cy 2 -L 3) n -Cy 3 -L 4 -Q 2
In the formula, Q ¹ and Q ² are each independently a polymerizable group, L ¹ and L ⁴ are each independently a divalent linking group, and L ² and L ³ are each independently a single bond or a divalent group. It is a linking group, Cy ¹ , Cy ² and Cy ³ are divalent cyclic groups, and n is 0, 1 or 2.

The polymerizable rod-like liquid crystal compound will be further described below.
^{(IV) Q 1 -L 1 -Cy} 1 -L 2 - (Cy 2 -L 3) n -Cy 3 -L 4 -Q 2
In the formula, Q ¹ and Q ² are each independently a polymerizable group. The polymerization reaction of the polymerizable group is preferably addition polymerization (including ring-opening polymerization) or condensation polymerization. In other words, the polymerizable group is preferably a functional group capable of addition polymerization reaction or condensation polymerization reaction. Examples of polymerizable groups are shown below.

L ¹ and L ⁴ are each independently a divalent linking group. L ¹ and L ⁴ are each independently selected from the group consisting of —O—, —S—, —CO—, —NR ² —, a divalent chain group, a divalent cyclic group, and combinations thereof. A valent linking group is preferred. R ² is an alkyl group having 1 to 7 carbon atoms or a hydrogen atom. R ² is preferably an alkyl group having 1 to 4 carbon atoms or a hydrogen atom, more preferably a methyl group, an ethyl group or a hydrogen atom, and most preferably a hydrogen atom. The example of the bivalent coupling group which consists of a combination is shown below. Here, the left side is coupled to Q (Q ¹ or Q ² ), and the right side is coupled to Cy (Cy ¹ or Cy ³ ).

L-1: —CO—O—divalent chain group—O—
L-2: —CO—O—divalent chain group —O—CO—
L-3: —CO—O—divalent chain group —O—CO—O—
L-4: -CO-O-divalent chain group -O-divalent cyclic group-
L-5: —CO—O—divalent chain group—O—divalent cyclic group—CO—O—
L-6: -CO-O-divalent chain group -O-divalent cyclic group -O-CO-
L-7: -CO-O-divalent chain group-O-divalent cyclic group-divalent chain group-
L-8: -CO-O-divalent chain group-O-divalent cyclic group-divalent chain group-CO-O-
L-9: -CO-O-divalent chain group-O-divalent cyclic group-divalent chain group-O-CO-
L-10: —CO—O—divalent chain group—O—CO—divalent cyclic group—
L-11: -CO-O-divalent chain group-O-CO-divalent cyclic group-CO-O-
L-12: -CO-O-divalent chain group -O-CO-divalent cyclic group -O-CO-
L-13: —CO—O—Divalent chain group—O—CO—Divalent cyclic group—Divalent chain group—L-14: —CO—O—Divalent chain group—O -CO-divalent cyclic group-divalent chain group-CO-O-
L-15: -CO-O-divalent chain group-O-CO-divalent cyclic group-divalent chain group-O-CO-
L-16: —CO—O—divalent chain group—O—CO—O—divalent cyclic group—
L-17: -CO-O-divalent chain group -O-CO-O-divalent cyclic group -CO-O-
L-18: -CO-O-divalent chain group -O-CO-O-divalent cyclic group -O-CO-
L-19: —CO—O—divalent chain group—O—CO—O—divalent cyclic group—divalent chain group—
L-20: -CO-O-divalent chain group-O-CO-O-divalent cyclic group-divalent chain group-CO-O-
L-21: -CO-O-divalent chain group-O-CO-O-divalent cyclic group-divalent chain group-O-CO-

  The divalent chain group means an alkylene group, a substituted alkylene group, an alkenylene group, a substituted alkenylene group, an alkynylene group, or a substituted alkynylene group. An alkylene group, a substituted alkylene group, an alkenylene group and a substituted alkenylene group are preferred, and an alkylene group and an alkenylene group are more preferred. The alkylene group may have a branch. The alkylene group preferably has 1 to 12 carbon atoms, more preferably 2 to 10 carbon atoms, and still more preferably 2 to 8 carbon atoms. The alkylene part of the substituted alkylene group is the same as the above alkylene group. Examples of the substituent include a halogen atom. The alkenylene group may have a branch. The alkenylene group preferably has 2 to 12 carbon atoms, more preferably 2 to 10 carbon atoms, and still more preferably 2 to 8 carbon atoms. The alkenylene part of the substituted alkenylene group is the same as the alkenylene group. Examples of the substituent include a halogen atom. The alkynylene group may have a branch. The alkynylene group preferably has 2 to 12 carbon atoms, more preferably 2 to 10 carbon atoms, and still more preferably 2 to 8 carbon atoms. The alkynylene part of the substituted alkynylene group is the same as the above alkynylene group. Examples of the substituent include a halogen atom.

  Specific examples of the divalent chain group include ethylene, propylene, tetramethylene, 2-methyl-1,4-butylene, pentamethylene, hexamethylene, octamethylene, 2-butenylene, 2-butynylene and the like.

The definition and examples of the divalent cyclic group are the same as those of Cy ¹ , Cy ² and Cy ³ described later.

L ^{2 and} L ³ are each independently a single bond or a divalent linking group. L ² and L ³ are each independently two selected from the group consisting of —O—, —S—, —CO—, —NR ² —, a divalent chain group, a divalent cyclic group, and combinations thereof. A valent linking group or a single bond is preferred. R ² is an alkyl group having 1 to 7 carbon atoms or a hydrogen atom, preferably an alkyl group having 1 to 4 carbon atoms or a hydrogen atom, and is a methyl group, an ethyl group or a hydrogen atom. Is more preferable, and a hydrogen atom is most preferable. The divalent chain group and the divalent cyclic group have the same definitions as L ¹ and L ⁴ .

In the formula (IV), n is 0, 1 or 2. When n is 2, two L ³ may be the same or different, and two Cy ² may be the same or different. n is preferably 1 or 2, and more preferably 1.

In formula (IV), Cy ¹ , Cy ² and Cy ³ are each independently a divalent cyclic group. The ring contained in the cyclic group is preferably a 5-membered ring, a 6-membered ring, or a 7-membered ring, more preferably a 5-membered ring or a 6-membered ring, and most preferably a 6-membered ring. The ring contained in the cyclic group may be a condensed ring. However, it is more preferably a monocycle than a condensed ring. The ring contained in the cyclic group may be any of an aromatic ring, an aliphatic ring, and a heterocyclic ring. Examples of the aromatic ring include a benzene ring and a naphthalene ring. Examples of the aliphatic ring include a cyclohexane ring. Examples of the heterocyclic ring include a pyridine ring and a pyrimidine ring. As the cyclic group having a benzene ring, 1,4-phenylene is preferable. As the cyclic group having a naphthalene ring, naphthalene-1,5-diyl and naphthalene-2,6-diyl are preferable. The cyclic group having a cyclohexane ring is preferably 1,4-cyclohexylene. As the cyclic group having a pyridine ring, pyridine-2,5-diyl is preferable. The cyclic group having a pyrimidine ring is preferably pyrimidine-2,5-diyl.

  The cyclic group may have a substituent. Examples of the substituent include a halogen atom, a cyano group, a nitro group, an alkyl group having 1 to 5 carbon atoms, a halogen-substituted alkyl group having 1 to 5 carbon atoms, and an alkoxy group having 1 to 5 carbon atoms. , An alkylthio group having 1 to 5 carbon atoms, an acyloxy group having 2 to 6 carbon atoms, an alkoxycarbonyl group having 2 to 6 carbon atoms, a carbamoyl group, and an alkyl-substituted carbamoyl group having 2 to 6 carbon atoms And an acylamino group having 2 to 6 carbon atoms.

  Examples of the polymerizable rod-like liquid crystal compound represented by the formula (IV) are shown below, but are not limited thereto.

-Discotic liquid crystal compounds Discotic liquid crystal compounds can be obtained from various documents (C. Destrade et al., Mol. Crysr. Liq. Cryst., Vol. 71, page 111 (1981); edited by the Chemical Society of Japan). , Quarterly Chemical Review, No. 22, Liquid Crystal Chemistry, Chapter 5, Chapter 10 Section 2 (1994); B. Kohne et al., Angew. Chem. Soc. Chem. Comm., Page 1794 (1985). J. Zhang et al., J. Am.Chem.Soc., Vol.116, page 2655 (1994)). Either can be used in the present invention. Moreover, about superposition | polymerization of a discotic liquid crystalline compound, Unexamined-Japanese-Patent No. 8-27284 has description.

The discotic liquid crystalline compound preferably has a polymerizable group so that it can be fixed by polymerization. For example, a structure in which a polymerizable group is bonded as a substituent to a discotic core of a discotic liquid crystalline compound is conceivable. However, when a polymerizable group is directly connected to the discotic core, the alignment state is maintained in the polymerization reaction. It becomes difficult. Therefore, a structure having a linking group between the discotic core and the polymerizable group is preferable. That is, the discotic liquid crystalline compound having a polymerizable group is preferably a compound represented by the following formula.
D (-LP) _n
In the formula, D is a discotic core, L is a divalent linking group, P is a polymerizable group, and n is an integer of 4 to 12. Preferred specific examples of the discotic core (D), the divalent linking group (L) and the polymerizable group (P) in the above formula are (D1) to (D15) described in JP-A No. 2001-4837, respectively. ), (L1) to (L25), and (P1) to (P18), and the contents described in the publication can be preferably used.

  The above discotic (discotic) compounds generally have a structure in which these are used as a mother nucleus at the center of a molecule, and a linear alkyl group, an alkoxy group, a substituted benzoyloxy group, etc. are radially substituted as the linear chain. , Which shows liquid crystallinity and is generally called a discotic liquid crystal. However, the molecule itself is not limited to the above description as long as the molecule itself has negative uniaxiality and can give a certain orientation. Further, in the present invention, it is not necessary that the final product is formed from a discotic compound, for example, the low molecular discotic liquid crystal has a group that reacts with heat, light, or the like. As a result, it may be polymerized or cross-linked by reaction with heat, light or the like, resulting in high molecular weight and loss of liquid crystallinity.

Preferred examples of the discotic compound are shown below.

Other components The polymerizable liquid crystal composition may contain components other than the compound capable of bonding to the (meth) acryl group and the liquid crystal compound. For example, if desired, it may contain a polymerizable initiator, an alignment control agent, a surfactant and the like.
-Polymerization initiator As the polymerization initiator, any of a thermal polymerization initiator used in a thermal polymerization reaction and a photopolymerization initiator used in a photopolymerization reaction may be used, and a photopolymerization initiator is preferable. Examples of photopolymerization initiators include α-carbonyl compounds (described in US Pat. Nos. 2,367,661 and 2,367,670), acyloin ether (US Pat. No. 2,448,828). ), Α-hydrocarbon substituted aromatic acyloin compounds (described in US Pat. No. 2,722,512), polynuclear quinone compounds (US Pat. Nos. 3,046,127 and 2,951,758) Description), combinations of triarylimidazole dimers and p-aminophenyl ketone (described in US Pat. No. 3,549,367), acridine and phenazine compounds (Japanese Patent Laid-Open No. 60-105667, US Pat. No. 4,239) And oxadiazole compounds (described in U.S. Pat. No. 4,212,970).
The amount of the photopolymerization initiator used is preferably 0.01 to 20% by mass and more preferably 0.5 to 5% by mass of the polymerizable liquid crystal composition (solid content in the case of a coating liquid). preferable.

-Alignment controller The polymerizable liquid crystal composition may contain an alignment controller that controls the alignment of the liquid crystal. The alignment control agent can be selected according to the type of liquid crystal, the desired alignment state, and the like.
For example, when the composition contains a rod-like liquid crystal and the rod-like liquid crystal is to be oriented perpendicular to the layer surface (the long axis is perpendicular to the layer surface), it is preferable to contain an onium salt or the like in the composition. . Specific examples are described in JP-A-2006-301605 (Table 1, second phase difference regions 1 to 3) and the like, and any of them can be used.
Further, when the composition contains a rod-like liquid crystal and the rod-like liquid crystal is oriented horizontally with respect to the layer surface (the long axis is parallel to the layer surface), it is preferable to contain a triazine compound or the like in the composition. . Specific examples are described in JP-A-2006-293275 (Example 2) and the like, and any of them can be used.
Further, when the composition contains a discotic liquid crystal and the discotic liquid crystal is oriented perpendicularly to the layer surface (the disk surface is perpendicular to the layer surface), a pyridinium salt (Example 1) in the composition Etc. are preferably contained. Specific examples are described in JP-A-2006-285187 and the like, and any of them can be used.
When the composition contains a discotic liquid crystal and it is desired to align the discotic liquid crystal horizontally to the layer surface (the disk surface is horizontal to the layer surface), a specific fluorine-based polymer or the like is added to the composition. It is preferable to contain. Specific examples are described in JP-A-2006-267183 (Reference Example 2), and any of them can be used.

-Surfactant The polymerizable liquid crystal composition may contain a surfactant in order to improve applicability and the like. As the surfactant, a fluorine-based surfactant is preferable. Specifically, for example, compounds described in paragraph numbers [0028] to [0056] of JP-A No. 2001-330725 are exemplified.

-Formation method of optically anisotropic layer The optically anisotropic layer is prepared by applying the polymerizable composition as a coating liquid, coating the surface of the alignment film, drying to remove the solvent, and a desired alignment. It is preferable to obtain the state and fix the orientation state by polymerization.
As the solvent used for preparing the coating solution, an organic solvent is preferably used. Examples of the organic solvent include amide (eg, N, N-dimethylformamide), sulfoxide (eg, dimethyl sulfoxide), heterocyclic compound (eg, pyridine), hydrocarbon (eg, benzene, hexane), alkyl halide ( Examples, chloroform, dichloromethane), esters (eg, methyl acetate, butyl acetate), ketones (eg, acetone, methyl ethyl ketone), ethers (eg, tetrahydrofuran, 1,2-dimethoxyethane) are included. Alkyl halides and ketones are preferred. Two or more organic solvents may be used in combination. The coating liquid can be applied by a known method (eg, extrusion coating method, direct gravure coating method, reverse gravure coating method, die coating method).

After applying the polymerizable liquid crystal composition, it is dried to obtain a desired alignment state, and then cured by polymerization to form an optically anisotropic layer. Polymerization is preferably initiated by light irradiation, and ultraviolet light is preferably used for light irradiation. The irradiation energy is preferably 20 mJ / cm ^{2 to} 50 J / cm ² , and more preferably 100 mJ / cm ^{2 to} 800 mJ / cm ² . Furthermore, in order to accelerate the photopolymerization reaction, light irradiation may be performed under heating conditions.

  The thickness of the optically anisotropic layer is preferably 0.1 to 10 μm, more preferably 0.5 to 5 μm, and still more preferably 1 to 5 μm.

(Support)
The support that the optical film of the present invention has is preferably transparent, and specifically, is preferably a transparent support having a light transmittance of 80% or more. Among these, a polymer film is preferable. Examples of polymer films that can be used as supports include cellulose ester, polycarbonate, polysulfone, polyethersulfone, polyacrylate and polymethacrylate films. Among these, a cellulose ester film is preferable, an acetyl cellulose film is more preferable, and a triacetyl cellulose film is most preferable. The polymer film is preferably formed by a solvent cast method.

  In general, the thickness of the support is preferably 20 to 500 μm, and more preferably 40 to 200 μm. In addition, in order to improve the adhesion between the transparent support and the alignment film provided thereon, the support is subjected to surface treatment (eg, glow discharge treatment, corona discharge treatment, ultraviolet (UV) treatment, flame treatment). Also good. Furthermore, an adhesive layer (undercoat layer) may be provided on the support. Moreover, in order to give the slip property in a conveyance process or to prevent sticking with the back surface and the surface after winding up, the inorganic particle whose average particle diameter is about 10-100 nm is 5% by solid content mass ratio. You may form the polymer layer which mixed -40% on the back surface (surface on the opposite side to the surface which forms an optical anisotropic layer) of a support body. The polymer layer can be formed by a coating method or a co-casting method.

It is preferable from the viewpoint of durability that the surface of the support that is in contact with the alignment film is hydrophilized. Hydrophilization can also be achieved by the above-exemplified surface treatment, but among these, it is preferable to make hydrophilic by applying a liquid containing at least an organic solvent, a metal hydroxide salt, water, a compatibilizing agent, and a surfactant to the surface. . This hydrophilization method is particularly effective for a polymer film containing a cellulose-based polymer such as cellulose acylate. The liquid used for the hydrophilization is preferably an alkaline liquid. When the surface of a polymer film containing a cellulosic polymer such as cellulose acylate is treated with an alkaline solution, saponification proceeds, thereby making it hydrophilic.
The organic solvent preferably dissolves the metal hydroxide salt and does not dissolve the cellulose acylate film, and specific examples thereof include methanol, ethanol, isopropanol, isobutanol and the like.
Specific examples of the metal hydroxide salt are preferably alkali metal hydroxides, and include sodium hydroxide, potassium hydroxide and the like.
The compatibilizing agent is preferably a compound that forms a uniform solution by adding the agent when water, an organic solvent, and a metal hydroxide salt are mixed. Specific examples thereof include diethylene glycol, Propylene glycol, polyhydric alcohol and the like are included.
The surfactant is preferably a nonionic surfactant, and specific examples thereof include polyoxyethylene lauryl ether, polyoxyethylene nonyl ether, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether, polyoxyethylene stearyl ether, Oxyethylene oleyl ether, polyoxyethylene behenyl ether, and the like.

  The hydrophilization treatment can be carried out by applying the liquid onto the surface of a polymer film or the like used as a support, leaving it under heating as desired for 10 to 120 seconds, and then washing with water. Before the hydrophilization treatment, the film may be heated to about 30 to 80 ° C. if desired. Further, after coating, the film may be heated to about 30 to 80 ° C. as desired when the film is allowed to stand. Washing with water may be performed a plurality of times, and draining with an air knife or the like is preferable because the number of times of washing with water can be reduced. From the viewpoint of handleability and the like, the surface tension of the liquid is preferably 15 to 65 mN / m, and the viscosity is preferably 0.6 to 20 mPa · s.

Further, when the optical film of the present invention is used as an optical compensation film of a liquid crystal display device, the support preferably has a small optical anisotropy so as not to impair the optical compensation ability of the optical anisotropic layer. Furthermore, the wavelength dispersion of the retardation is preferably small. Specifically, the in-plane retardation of the support is preferably 10 nm or less, and more preferably 5 nm or less. Further, the wavelength dispersibility is specifically the ratio Re (400) / Re (700) between the in-plane retardation Re (400) at a wavelength of 400 nm and the in-plane retardation Re (700) at a wavelength of 700 nm. It is preferable that it is less than 1.2.
However, this is not the case in an aspect in which the optical characteristics necessary for the optical compensation capability are obtained by actively utilizing the optical characteristics of the support.

[Polarizer]
The present invention also relates to a polarizing plate having the optical film of the present invention, a polarizing film, and a protective film. The optical film of the present invention may be bonded as a protective film to one surface of the polarizing film. Hereinafter, the polarizing plate of the present invention will be described.
-Polarizing film The polarizing film includes an iodine polarizing film, a dye polarizing film using a dichroic dye, and a polyene polarizing film, and any of them may be used in the present invention. The iodine polarizing film and the dye polarizing film are generally produced using a polyvinyl alcohol film.

-Protective film It is preferable that a transparent polymer film is used for the protective film bonded to the other surface. “Transparent” means that the light transmittance is 80% or more. As the protective film, a cellulose acylate film and a polyolefin film containing polyolefin are preferable. Among the cellulose acylate films, a cellulose triacetate film is preferable. Of the polyolefin films, a polynorbornene film containing a cyclic polyolefin is preferable.
The thickness of the protective film is preferably 20 to 500 μm, and more preferably 50 to 200 μm.

  The optical film and the polarizing plate of the present invention are liquid crystal display devices of various modes, TN (Twisted Nematic), IPS (In-Plane Switching), OCB (Optically Compensated Bend), VA (Vertically Aligned), ECB (Electrically Bending). And the like can be used for liquid crystal display devices in any display mode. In addition, the liquid crystal display device can be any of a transmissive type, a reflective type, and a transflective type.

Hereinafter, the features of the present invention will be described more specifically with reference to Examples and Comparative Examples. The materials, amounts used, ratios, processing details, processing procedures, and the like shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the specific examples shown below.
[Example 1]
(Production of support)
The following composition was put into a mixing tank and stirred while heating at 30 ° C. to dissolve each component to prepare a cellulose acylate solution (SA-1) (inner layer dope and outer layer dope).
Regarding the silica fine particles of the cellulose acylate solution for the outer layer, 20 parts by mass of the following silica fine particles and 80 parts by mass of methanol were mixed well for 30 minutes to obtain a mixed silica molecular dispersion.

Cellulose acylate (SA-1) solution composition:
Cellulose acylate solution composition (parts by mass) For inner layer For outer layer Cellulose acetate with an acyl substitution degree of 2.87 100 100
Triphenyl phosphate (plasticizer) 7.8 7.8
Biphenyl diphenyl phosphate (plasticizer) 3.9 3.9
Methylene chloride (first solvent) 293 314
Methanol (second solvent) 71 76
1-butanol (third solvent) 1.5 1.6
Silica fine particles (AEROSIL R972, manufactured by Nippon Aerosil Co., Ltd.)
0 0.8
Retardation adjuster A 1.50

  When the particle size distribution of the silica fine particle dispersion was measured for the obtained outer layer dope, the particle size of 500 nm or more was 0%.

The obtained inner layer dope and outer layer dope were cast on a drum cooled to −5 ° C. using a three-layer co-casting die.
The drum had an arithmetic average roughness (Ra) of 0.006 μm, a maximum height (Ry) of 0.06 μm, and a ten-point average roughness (Rz) of 0.009 μm. The arithmetic average roughness (Ra), maximum height (Ry), and ten-point average roughness (Rz) were measured according to JIS B 0601.
The film having a residual solvent amount of 70% by mass was peeled off from the drum, and dried at 80 ° C. while being transported with the draw ratio in the transport direction being 110% while holding both ends with a pin tenter, and the residual solvent amount was 10%. By the way, it was dried at 110 ° C. Thereafter, it was dried at a temperature of 140 ° C. for 30 minutes to prepare a cellulose acylate film (CAF-1, outer layer: 3 μm, inner layer: 74 μm, outer layer: 3 μm) having a residual solvent of 0.3% by mass. The obtained CAF-1 had a width of 1340 mm and a thickness of 80 μm.
The obtained film CAF-1 had an in-plane slow axis in the longitudinal direction, Re (630) was 8 nm, and | Rth (630) | was 80 nm. Further, | Re (400) -Re (700) | was 8 nm, and | Rth (400) -Rth (700) | was 15 nm.

(Various properties of cellulose acylate film CAF-1)
The obtained cellulose acylate film CAF-1 was measured for the following properties, and the results are summarized in Table 1 below.
<Uneven shape on film surface>
The surface shape of the band side surface of the obtained cellulose acylate film CAF-1, specifically, arithmetic average roughness (Ra), maximum height (Ry), and ten-point average roughness (Rz) were measured. . Each measurement was based on JIS B 0601.
<Retardation value>
Using an ellipsometer (M-150, manufactured by JASCO Corporation), Re retardation value Re (550) and Rth retardation value Rth (550) at a wavelength of 550 nm were measured.
《Slow axis misalignment》
The off-axis angle was measured with an automatic birefringence meter (KOBRA-21ADH, Oji Scientific Instruments). Each measurement was performed at 10 points in the width direction, and an average value was obtained.
《Haze》
Haze was measured using a haze meter (1001DP type, manufactured by Nippon Denshoku Industries Co., Ltd.). Five points were measured per film sample, and the average value was adopted.

"curl"
The curl value was measured according to a measurement method (ANSI / ASCPH1.29-1985, Method-A) defined by the American National Standards Institute. The polymer film is cut to a size of 35 mm in the width direction and 2 mm in the longitudinal direction, and then placed on the curl plate. The curl value is read after conditioning for 1 hour in an environment of temperature 25 ° C. and relative humidity 65%. Similarly, the polymer film is cut to a size of 2 mm in the width direction and 35 mm in the longitudinal direction, and then placed on the curl plate. The curl value is read after conditioning for 1 hour in an environment of temperature 25 ° C. and relative humidity 65%. Measurement was made in two directions, the width direction and the longitudinal direction, and the larger value of both values was taken as the curl value. The curl value is represented by the reciprocal of the radius of curvature (m).
<< Tear Strength >>
A film is cut into 65 mm × length 50 mm to prepare a sample. This sample was conditioned for 2 hours or more in a room at a temperature of 30 ° C. and a relative humidity of 85%, and in accordance with the ISO 6383 / 2-1983 standard, a load (g )

  As shown in Table 1 above, the cellulose acylate film (CAF-1) had a good surface shape, and the surface shape was uniform in unevenness with the values shown in Table 1. Further, the optical properties of retardation value, slow axis angle deviation and haze value and the mechanical properties of curl and tear strength were also good.

Alkali saponification treatment One side of the film CAF-1 was subjected to the following alkali saponification treatment.
The film (CAF-1) is passed through a dielectric heating roll having a temperature of 60 ° C. and heated to a film surface temperature of 40 ° C., and then an alkali solution (S-1) having the composition shown below is used with a rod coater. It apply | coated with the application quantity of 17 mL / m < ² >, and it was made to retain for 10 second under the steam type far-infrared heater by Noritake Co., Ltd. which was heated to 110 degreeC. Then, using a rod coater as well, “applying 2.8 mL / m ^{2 of} distilled water, then washing with a fountain coater and draining with an air knife three times to wash off the alkali, The film was allowed to stay for 2 seconds and dried to produce a saponified film KF-1.

Alkaline solution (S-1) composition:
Potassium hydroxide 8.6 parts by weight Water 24.1 parts by weight Isopropanol 56.3 parts by weight Surfactant (K-1: C ₁₆ H ₃₃ O (CH ₂ CH ₂ O) ₁₀ H) 1.0 part by weight Propylene glycol 10.0 parts by mass

Alkaline solution (S-1) properties:
Surface tension 20mN / m
Viscosity 5.2 mPa · s

  When the surface of the saponified film KF-1 was measured for the contact angle with water, the result of measurement at 10 points was in the range of 36 to 38 °.

(Preparation of coating solution for alignment film)
Using the PVA shown in Table 2, various coating solutions for alignment films having the following compositions were prepared. In the composition, the numbers are parts by weight.
Composition of alignment film coating solution:
PVA (described in Table 2) 1.244
Glutaraldehyde (50% aqueous solution) 0.12
A mixture of citric acid, 1 ethyl citrate, 2 ethyl citrate, and 3 ethyl citrate
0.022
Methanol 9.02
Water 28.794

In Table 2, PVA110, PVA117, PVA124, PVA135, PVA203, PVA103, and PVA105 are trade names of unmodified PVA manufactured by Kuraray Co., Ltd. The average degree of polymerization and degree of saponification are shown in Table 2. Indicated.
In Table 2, modified PVA is in accordance with Synthesis Example 1 described in the [0101] column of JP-A-9-152509, except that PVA203 (Kuraray Co., Ltd.) is used instead of MP203 (Kuraray Co., Ltd.). Is a modified PVA manufactured using Although the average degree of polymerization of PVA203 is shown in Table 2, there is no change in average polymerization after modification.
In Table 2, mixed PVA1 is a mixture of PVA124 and modified PVA at a mass ratio of 8: 2, mixed PVA2 is a mixture of PVA124 and modified PVA at a mass ratio of 5: 5, and mixed PVA3. Is a mixture of PVA217 and modified PVA in a mass ratio of 8: 2, and mixed PVA5 is a mixture of PVA203 and modified PVA in a mass ratio of 8: 2. The mixed PVA 4 is a 7: 3 mixture by mass ratio of PVA 124 and unmodified PVA having an average degree of polymerization of 100 and a saponification degree of 99%.
Regarding the mixture, Table 2 shows the average polymerization and saponification degree of the higher average polymerization degree of the two types of PVA.

(Formation of alignment layer)
Each of the alignment film coating solutions prepared above was applied to the saponified surface of the saponified film (KF-1) at a coating amount of 31 mL / m ² and dried at a temperature of 100 ° C. for 2 minutes. Each of the substrates with alignment films was prepared.

(Preparation of coating liquid D-1 for optical anisotropy)
A coating liquid D-1 for an optically anisotropic layer containing a discotic liquid crystal having the following composition was prepared.
Composition of coating liquid D-1:
The following discotic liquid crystal DLC-A 9.1 parts by mass Ethylene oxide-modified trimethylolpropane acrylate (V # 360, trade name, Osaka Organic Chemical Co., Ltd.) 0.9 parts by mass Cellulose acetate butyrate (CAB551-0.2, 0.2 parts by weight Cellulose acetate butyrate (CAB531-1, trade name, manufactured by Eastman Chemical) 0.05 parts by weight The following fluorine compound (F-1) 1.3 parts by weight Iruga Cure 907 (trade name, manufactured by Ciba Geigy) 3.0 parts by mass Kaya Cure DETX (trade name, manufactured by Nippon Kayaku Co., Ltd.) 0.1 parts by mass 4-vinylphenylboronic acid (manufactured by ARDRICH) 0.0455 parts by mass Methyl ethyl ketone 29.6 parts by mass

(Preparation of coating liquid D-2 for optically anisotropic layer)
A coating liquid D-2 for an optically anisotropic layer containing a discotic liquid crystal having the following composition was prepared.
Composition of coating liquid D-2 for optically anisotropic layer:
The following discotic liquid crystal 1 20.3 parts by mass The following discotic liquid crystal 2 235.1 parts by mass The fluorine compound (F-1) 2.558 parts by mass Irgacure-907 7.556 parts by mass Kayacure DEXT 2.519 parts by mass 4- Vinyl phenylboronic acid (made by ARDRICH) 1.277 parts by mass Methyl ethyl ketone 1438.6 parts by mass

(Preparation of coating liquid D-3 for optically anisotropic layer)
A coating liquid for optically anisotropic layer (D-3) was prepared in the same manner except that 4-vinylphenylboronic acid was not used in the preparation of coating liquid D-1.

(Preparation of optical films F-1 to F-17)
After rubbing the alignment film surface of the support with the alignment film, any one of the coating liquids D-1 to D-3 for the optically anisotropic layer is applied to each rubbing surface at 5.2 mL / m ^2. The liquid crystal layer was aged at 115 ° C. for 90 seconds to align the liquid crystal layer. Subsequently, UV irradiation was performed after the entire coated product reached 80 ° C., and the liquid crystal layer was fixed in an aligned state. Thus, optically anisotropic films F1-1 to F1-17 were produced.
The combinations of the support with an alignment film and the coating liquids D-1 to D-3 for the optically anisotropic layer are shown in Table 2 below.

(Durability evaluation of optical film)
The produced optical films F1-1 to F1-17 were immersed in warm water at 40 ° C. for 30 minutes, and then the film was rubbed strongly to evaluate the adhesion of the film. The evaluation criteria are as follows.
1: Does not peel off.
2: Peel off when rubbed strongly.
3: Lightly rubs off.
4: Peel off without touching. It is.
The evaluation results are shown in Table 2.

(Preparation of polarizing plate)
About the optical films F1-1 to F1-17 produced above, the back surface of the support (the surface on which the alignment film and the optically anisotropic layer are not formed) was saponified. Specifically, it was immersed in a 1.5N sodium hydroxide aqueous solution (55 ° C., 2 minutes) and then washed with water (room temperature, 15 seconds). Further, it was immersed in 0.1N sulfuric acid (30 ° C., 20 seconds) and then washed with water (room temperature, 15 seconds).
Using a polyvinyl alcohol-based adhesive, the back surface of each optical film subjected to saponification treatment was attached to one surface of the polarizing film.
Next, a cellulose triacetate film (TD-80UF: manufactured by Fuji Film Co., Ltd.) having a thickness of 80 μm is subjected to the above saponification treatment, and the surface on the opposite side of the polarizing film is coated with a polyvinyl alcohol adhesive. Pasted on.
The transmission axis of the polarizing film and the slow axis of the cellulose acylate film (CAF-01) were arranged in parallel. The transmission axis of the polarizing film and the slow axis of the cellulose triacetate film were arranged so as to be orthogonal. In this way, polarizing plates H1-1 to H1-17 were produced.

(Durability evaluation of polarizing plate)
A pressure-sensitive adhesive was applied to the optically anisotropic layer side of each produced polarizing plate, and a sample attached to a glass plate was produced. The sample was allowed to stand in an atmosphere of 65 ° C. and 95% for 6 hours, and then each sample was observed by five persons and evaluated according to the following criteria.
1: No particular change is observed.
2: One out of five people recognized that the optically anisotropic layer had cracks.
3: Two out of five people recognized that the optically anisotropic layer had cracks.
4: Three or more people out of five recognized that the optically anisotropic layer had cracks.
The evaluation results are shown in Table 2 below.

[Example 2]
(Production and evaluation of optical film)
A coating liquid containing a rod-like liquid crystal compound described in JP-A-2006-215092 [0198] to [0200], that is, a coating liquid N-1 having the following composition was prepared.
Composition of coating liquid N-1:
The following rod-shaped liquid crystal compound A 3.8 g
Photopolymerization initiator (Irgacure 907, manufactured by Ciba Geigy) 0.06 g
Sensitizer (Kayacure DETX, manufactured by Nippon Kayaku Co., Ltd.) 0.02g
Boronic acid compound (specific example (I-28) described above) 0.076 g
The following air interface side vertical alignment agent 0.002g
9.2 g of methyl ethyl ketone

This coating solution N-1 was applied to the support with an alignment film shown in Table 3 below prepared in Example 1 with a # 4.5 wire bar. This was affixed to a metal frame and heated in a constant temperature bath at 100 ° C. for 2 minutes to align the rod-like liquid crystal compound. Next, UV irradiation was performed at 80 ° C. with a 120 W / cm high-pressure mercury lamp for 20 seconds to crosslink the rod-like liquid crystal compound, and then the mixture was allowed to cool to room temperature to form an optically anisotropic layer. F2-4 was prepared respectively.
The durability of optical films F2-1 to F2-4 produced in the same manner as in Example 1 was evaluated. The results are shown in Table 3 below.

(Production and evaluation of polarizing plate)
In the same manner as in Example 1, polarizing plates H2-1 to H2-4 each having optical films F2-1 to F2-4 attached as protective films were prepared, and in the same manner as in Example 1, polarizing plates were prepared. The durability was evaluated. The evaluation results are shown in Table 3 below.

[Example 3]
A polarizing plate was prepared in the same manner as in Example 1 except that the optical film F1-6 produced above was used and that an ARTON film (manufactured by JSR) was used instead of the cellulose triacetate film having a thickness of 80 μm. Produced. The surface on the side in contact with the polarizing film was subjected to corona treatment (120 mW / min). The contact angle of the treated surface with water was 65 °. The durability of the produced polarizing plate was 1 based on the above evaluation criteria, which was a satisfactory performance.

Claims (14)

An optical film having an optically anisotropic layer formed by curing a support, an alignment film, and a polymerizable liquid crystal composition, wherein the alignment film has an average polymerization degree of 800 to 5000 and a polymer having a hydroxyl group An optical film comprising at least one of the above. The optical film according to claim 1, wherein the optically anisotropic layer contains at least one boronic acid compound having a group capable of bonding to a (meth) acryl group. The optical film according to claim 1, wherein the polymer is polyvinyl alcohol having no modifying group. The optical film according to any one of claims 1 to 3, wherein the average degree of polymerization of the polymer is 1200 to 5000. The optical film according to any one of claims 1 to 4, wherein the saponification degree of the polymer is 85% or more. The optical film according to any one of claims 1 to 4, wherein the saponification degree of the polymer is 95% or more. The optical film according to claim 1, wherein the polymerizable liquid crystal composition contains at least one discotic liquid crystal compound. The optical film according to claim 1, wherein the polymerizable liquid crystal composition contains at least one rod-like liquid crystal compound. The optical film according to claim 1, wherein the surface of the support that is in contact with the alignment film is hydrophilized. The optical film according to claim 9, wherein the optical film is hydrophilized by applying a liquid containing at least an organic solvent, a metal hydroxide salt, water, a compatibilizing agent, and a surfactant to the surface. The optical film according to claim 1, wherein the support includes a cellulosic polymer. A polarizing plate comprising the optical film according to claim 1, a polarizing film, and a protective film. The polarizing plate according to claim 12, wherein the protective film contains polyolefin. The polarizing plate according to claim 12, wherein the protective film contains polynorbornene.