JP2001081469A - Liquid crystal material and liquid crystal film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a liquid crystal material that can give a liquid crystal film improved in mechanical strengths by mixing a liquid crystal polymer with a non-liquid-crystal polymer having a specified weight-average molecular weight. SOLUTION: The liquid crystal polymers herein used mean liquid crystal polymers that assume a nematic liquid crystal phase or a cholesteric liquid crystal phase and include main-chain-type and/or side-chain-type liquid crystal polymers, liquid crystal oligomers, their copolymers, and their mixtures. The non-liquid-crystal polymer used in combination with the liquid crystal polymer is one having a weight-average molecular weight of at least 10,000, desirably, at least 20,000, more desirably, at least 50,000 and a glass transition temperature of room temperature to 300 deg.C, desirably, 30-250 deg.C, more desirably, 40 to 200 deg.C. An acrylic polymer or copolymer made from methyl acrylate, methyl methacrylate, or the like is desirable as the non-liquid-crystal polymer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal film which is excellent in mechanical strength such as peel strength and does not cause cohesive failure.

[0002]

2. Description of the Related Art Nematic liquid crystal and cholesteric liquid crystal films have been widely used in recent years as optical and design applications because of their optical characteristics such as anisotropy in refractive index and appearance. In particular, cholesteric liquid crystal films are attracting attention because liquid crystal molecules are regularly twisted and oriented to draw a spiral in the film thickness direction, and exhibit characteristic characteristics such as circularly polarized light selective reflection. Utilizing this property, optical use to extract only left or right circularly polarized light from non-polarized light, or reflected / transmitted light colored because this circularly polarized light selective reflectivity is limited to a specific wavelength band. Application to decorative uses such as decorative members utilizing the above has been considered. Reflected / transmitted light has a metallic luster texture unique to cholesteric liquid crystals, and the optical characteristics of cholesteric liquid crystals cannot be duplicated by copiers. I have. In applying a liquid crystal film to these various uses, the mechanical strength of the film itself is often a problem. Nematic alignment, the liquid crystal film that maintains the cholesteric alignment,
Due to the orientation structure, the orientation layer has a plane such as a cleavage plane in the crystal phase between the orientation layers, and the peeling stress on the plane is extremely poor. In addition, when a laminate is obtained using such a liquid crystal film, or when a liquid crystal film is used by laminating the film, the use form is maintained because the film easily causes cohesive failure with respect to external force. There are inconveniences that cannot be done. As a method for compensating this point, for example, a method of sandwiching a liquid crystal film between supporting substrates such as a tough transparent film or glass to increase mechanical strength, a method of increasing the molecular weight of liquid crystal molecules to be a material of the liquid crystal film, and the like have been proposed. ing. However, in the method of sandwiching the liquid crystal film between the supporting substrates, it is difficult to reduce the thickness, and depending on the type of the supporting substrate, it may not be possible to sufficiently obtain the desired optical characteristic effect. On the other hand, in the method of increasing the molecular weight, there is a concern that the increase in the molecular weight lowers the alignment property, making it difficult to obtain a desired liquid crystal phase or alignment structure.

[0003]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and uses a liquid crystal material containing a liquid crystal polymer and a non-liquid crystal polymer having a specific molecular weight. The inventors succeeded in improving the mechanical strength of the obtained liquid crystal film, and reached the present invention.

[0004]

That is, an object of the present invention is to provide a liquid crystal material containing a liquid crystal polymer and a non-liquid crystal polymer having a weight average molecular weight of 10,000 or more.
Another object of the present invention is to provide a liquid crystal film which does not have the drawbacks found in conventional liquid crystal films from this liquid crystal material.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
The liquid crystalline polymer used in the present invention refers to a liquid crystalline polymer exhibiting a nematic liquid crystal phase or a cholesteric liquid crystal phase, and includes a main chain type and / or a side chain type liquid crystalline polymer compound and a liquid crystalline oligomer. -, Their copolymers and their mixtures. Among the liquid crystalline polymers usable in the present invention, examples of the main chain type liquid crystalline polymer exhibiting a nematic liquid crystal phase include polyamide,
Examples thereof include polyamic acid, polyimide, polyester, polyether, polysulfide, and cellulose derivative. Among these main chain type liquid crystalline polymers, liquid crystalline polyesters are preferred in terms of liquid crystallinity and orientation. Preferable examples of the polyester include a main chain polyester comprising an aromatic or aliphatic diol unit, an aromatic or aliphatic dicarboxylic acid unit, or an aromatic or aliphatic hydroxycarboxylic acid unit. The main-chain type polyester as described above is prepared by a melt condensation polymerization method such as deacetic acid polymerization using a dicarboxylic acid unit and a diacetate derivative of an aromatic diol and / or an acetate derivative of hydroxycarboxylic acid, or acid chloride, sulfonic acid or the like. A carboxylic acid unit and a diol unit introduced into a derivative such as an anhydride can be easily obtained by a known polyester synthesis method exemplified by a solution polymerization method of esterifying in a solution,
There is no limitation on the synthesis method.

On the other hand, as a side chain type liquid crystalline polymer exhibiting a nematic liquid crystal phase, polysiloxane, polyacrylate, polymethacrylate, polymalonate, and the like are used as a main chain skeleton. Examples include those having a structure in which a low-molecular liquid crystal compound such as a para-substituted cyclic compound serving as a mesogen is bonded via a spacer formed of a conjugated atomic group. Among these side chain type liquid crystalline polymers, a liquid crystalline polymer having polyacrylate as a main chain skeleton is desirable from the viewpoints of liquid crystallinity and orientation, ease of synthesis and stability of the polymer. As the para-substituted cyclic compound capable of expressing a nematic liquid crystal phase, for example, azomethine type, azo type, azoxy type, ester type,
Para-substituted aromatic units such as substituted or unsubstituted phenylene type, substituted or unsubstituted biphenyl type, terphenyl type, phenylcyclohexane type, substituted or unsubstituted naphthalene type, anthracene type, and 1,4-substituted cyclohexane And compounds having a substituted cyclohexane ring unit such as a bicyclohexane type. Among these, those having a skeleton of a phenylene type, 1,4-cyclohexane type, biphenyl type, or the like having strong liquid crystallinity are preferable, and those mesogens in which a polar group such as a cyano group is introduced at a terminal of a mesogen portion are particularly preferable. It is preferably used. There is no particular limitation on the method for synthesizing the side chain type liquid crystalline polymer as described above, and it can be synthesized using a known method. For example, as a method for synthesizing a side chain type liquid crystal compound having a polyacrylate as a main chain, a polymerization in which a polymerizable group such as an acryl group or a methacryl group is introduced at one end of a mesogen or an end at which a spacer is introduced into a mesogen. Examples include a method of synthesizing a reactive monomer and polymerizing the monomer by a radical reaction or the like.

Another liquid crystal polymer usable in the present invention is a liquid crystal polymer exhibiting a cholesteric liquid crystal phase (chiral nematic liquid crystal phase). The polymer liquid crystal includes a liquid crystal polymer in which an optically active group is introduced into a main chain skeleton, a spacer, or a mesogen of a main chain type and / or a side chain type liquid crystal polymer exhibiting the above nematic liquid crystal phase. ,
A mixture of an optically active compound and a liquid crystalline polymer exhibiting a nematic liquid crystal phase. That is, the liquid crystalline polymer exhibiting a cholesteric liquid crystal phase referred to in the present invention means, of course, a liquid crystalline polymer exhibiting a cholesteric liquid crystal phase by itself, but does not exhibit a cholesteric liquid crystal phase by itself, but It also means a liquid crystalline polymer that exhibits a cholesteric liquid crystal phase when used in combination with a compound having an active group. As the compound having an optically active group, any compound capable of forming a cholesteric alignment in a liquid crystalline polymer without impairing the effects of the present invention can be used. This compound does not matter whether it is a low molecular weight compound or a high molecular weight compound, and it does not matter whether it is liquid crystalline or not. The compound having an optically active group means a compound having the following monovalent or divalent group containing an optically active carbon atom (asymmetric carbon atom) in a molecule.

Embedded image (In the above formula, * represents an optically active carbon atom, and Me represents a methyl group.) As a raw material monomer for preparing a main chain type and / or side chain type liquid crystalline polymer, By using a compound having an optically active group as exemplified above, a liquid crystalline polymer having an optically active group introduced into a main chain or a side chain can be obtained. As described above, this liquid crystalline polymer can itself form a cholesteric liquid crystal phase without being mixed with a compound having an optically active group. The ratio of the optically active group introduced into the liquid crystalline polymer varies depending on the type of optically active group, the site of introduction, the type (composition ratio, etc.) and structure of the liquid crystalline polymer, but cannot be determined unconditionally. The number of moles of the optically active group contained per unit weight of the liquid crystalline polymer is usually 0.0001 to 0.05 mol / g, preferably 0.0002 to 0.02 mol / g, and more preferably 0.0005 to 0 mol / g. 0.01 mol / g.
If the amount is less than 0.0001 mol / g, sufficient torsion may not be induced. 0.05m
Introduction of an optically active group exceeding ol / g is not practical and not economical. The above-described mole number of the optically active group is also applicable to a case where an optically active compound is blended with a liquid crystalline polymer which does not form a cholesteric liquid crystal phase by itself. Furthermore, as the liquid crystalline polymer of the present invention, a polymer compound having a polymerizable functional group in a polymer main chain skeleton, a spacer or a mesogen can also be used. By using a liquid crystalline polymer having a polymerizable functional group, operations using fluidity due to heating, for example, orientation, thermal deformation, engraving (embossing) of the polymer surface, and the like are performed.
A liquid crystal film having thermal and mechanical stability can be obtained by performing a cross-linking reaction using the polymerizable functional group. As the polymerizable functional group, for example, vinyl group, allyl group, vinyl ether group, acrylic group, methacryl group, vinyl polymer group such as maleic ester,
Examples include an azide group, an isocyanate group, an epoxy group, a methylol group or an alkyl ether of a methylol group. Also, by introducing a functional group having an active hydrogen such as a hydroxy group, a carboxyl group, or a mercapto group into the polymer main chain skeleton, and separately adding a substance having a reactive group such as an isocyanato group, fluidization by heating can be achieved. Crosslinking can also be performed after an operation utilizing the properties. In the present invention, such a functional group having active hydrogen is also included as a polymerizable functional group.

The molecular weight of the main chain type and / or side chain type liquid crystalline polymer exhibiting a nematic liquid crystal phase or a cholesteric liquid crystal phase used in the present invention depends on the kind of the monomer, the synthesis method, or the optical properties and reliability of the final product. Since it depends on the properties, strength, process conditions, etc., it cannot be said unconditionally, but the weight average molecular weight is usually from 300 to 100,000.
0, preferably 500 to 50,000, more preferably 1,000 to 10,000. In addition, the intrinsic viscosity is determined by using phenol / tetrachloroethane (6/4) as a solvent.
(Weight ratio) at 30 ° C., usually 0.01 to 1.0 dl / g, preferably 0.05 to 1.0 dl / g.
It is desirable to be in the range of 0.5 dl / g. When the weight average molecular weight is lower than 300, the strength and thermal stability as a polymer may be extremely low, or the smectic liquid crystal phase or the crystal may be in a temperature range lower than the nematic liquid crystal phase or the cholesteric liquid crystal phase. There is a possibility that a higher-order phase such as a phase is developed and cannot be fixed in the cholesteric liquid crystal phase. If it is higher than 100,000,
An increase in melt viscosity may make it difficult to orient under normal heat treatment conditions. The glass transition temperature (Tg) of the liquid crystalline polymer used in the present invention is preferably room temperature or higher, usually from room temperature to 250 ° C., and preferably from 40 to 250 ° C.
It is desirable in the present invention that the temperature is in the range of 200 ° C, more preferably 50 to 150 ° C. If the Tg is lower than room temperature, it may be difficult to fix the film with a liquid crystal phase, and if it exceeds 250 ° C., it may be difficult to form a liquid crystal alignment by heat treatment.

The non-liquid crystalline polymer of the present invention mixed with the above liquid crystalline polymer has a weight average molecular weight of 10,000.
0 or more, preferably 20,000 or more, more preferably 50,000 or more, and the glass transition temperature (Tg)
However, it is in the range of room temperature to 300 ° C, preferably 30 ° C to 250 ° C, more preferably 40 ° C to 200 ° C.
There is no limitation on the type of the polymer compound that satisfies this condition. For example, ethylene, propylene, butene, styrene, vinyl alcohol, vinyl formal, vinyl acetate, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, benzyl methacrylate, vinyl polymers and the like as raw materials and these Copolymers and block copolymers using two or more of them as raw materials; polyesters such as polyethylene terephthalate, polyethylene naphthalate, and poly (bisphenol A carbonate); cellulose, acetylcellulose, triacetylcellulose, cellulose acetate butyrate, and hydroxypropyl Cellulose-based polymers such as cellulose; polyamides, polyimides, polyurethanes and the like,
Any of them can be used as the non-liquid crystalline polymer of the present invention. Among them, acrylic polymers and their copolymers using methyl acrylate, methyl methacrylate and the like as raw materials, and cellulose polymers such as triacetyl cellulose and cellulose acetate butyrate are suitable as the non-liquid crystalline polymer of the present invention.

The liquid crystal material of the present invention contains the above-mentioned liquid crystalline polymer and non-liquid crystalline polymer, and from this liquid crystal material, it is possible to obtain a liquid crystal film having excellent mechanical strength, especially excellent peeling resistance and breaking resistance. it can. And, when the liquid crystal film made from the liquid crystal material of the present invention is a laminate,
For example, when a liquid crystal film is bonded to another laminated member via a viscous adhesive, the adhesion between the liquid crystal film and the other laminated member can be improved, and as a result, the mechanical strength of the laminated product can be improved. Can be improved. Some liquid crystal materials of the present invention cause a phase separation phenomenon depending on the types, compositions, molecular structures, and the like of liquid crystal polymers and non-liquid crystal polymers contained therein. When a liquid crystal film is obtained using a liquid crystal material that causes this phase separation phenomenon, optical effects such as light diffusing ability and light scattering ability can be obtained. Note that the phase separation phenomenon mentioned here may occur in a liquid state or a solution state of the liquid crystal material of the present invention containing a liquid crystalline polymer and a non-liquid crystalline polymer. Also, in the solution, even if the liquid crystalline polymer and the non-liquid crystalline polymer are compatible, cast the solution,
Phase separation may occur gradually at the stage of heating orientation,
Even in such a case, the liquid crystal film of the present invention having an intended optical effect can be obtained. The proportion of the non-liquid crystalline polymer in the liquid crystal material depends on the type and composition of the liquid crystalline polymer, the type and the molecular structure of the non-liquid crystalline polymer, and cannot be unconditionally determined. 0.1 to 95 parts by weight, preferably 0.5 to 95 parts by weight, per 100 parts by weight
90 parts by weight, more preferably 1 to 80 parts by weight, most preferably 5 to 60 parts by weight. 0.
If the amount is less than 1 part by weight, sufficient mechanical strength may not be obtained. On the other hand, when the amount exceeds 95 parts by weight, the liquid crystal material does not exhibit liquid crystallinity, and there is a possibility that the alignment may be deteriorated or the alignment may be broken.

When a liquid crystal film is manufactured using the liquid crystal material of the present invention, the nematic liquid crystal phase or the cholesteric liquid crystal phase formed by the liquid crystal material is hindered or broken.
In addition, various additions of a photopolymerization initiator, a sensitizer, a dichroic dye, a dye, a pigment, an ultraviolet absorber, a hard coat agent, an antioxidant, and the like to the liquid crystal material within a range that does not impair the effects of the present invention. One or more agents can be blended. Any method can be used to form the liquid crystal film. As a typical example, a liquid crystal material in a solution state is spread on a single support film to form a film, and a desired liquid crystal is formed by heat treatment or the like. A method for fixing the orientation after obtaining the orientation will be described below. Solvent for solution preparation Solvents for dissolving or dispersing the liquid crystal material include, for example, hydrocarbons such as benzene, toluene, xylene, n-butylbenzene, diethylbenzene and tetralin, methoxybenzene, 1,2-dimethoxybenzene, diethylene glycol dimethyl ether and the like. Ethers, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, ketones such as 2,4-pentanedione, ethyl acetate, ethylene glycol monomethyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, γ-butyrolactone Esters, such as 2-pyrrolidone, N-methyl-2-pyrrolidone, dimethylformamide,
Amide solvents such as dimethylacetamide, halogen solvents such as chloroform, dichloromethane, carbon tetrachloride, dichloroethane, tetrachloroethane, tritrichloroethylene, tetrachloroethylene, chlorobenzene, orthodichlorobenzene, tert-butyl alcohol, diacetone alcohol, glycerin, monoacetin, ethylene Alcohols such as glycol, triethylene glycol, hexylene glycol, ethylene glycol monomethyl ether, ethyl cellosolve, butyl cellosolve,
One or more phenols such as phenol and parachlorophenol can be used. Even if only a single type of solvent is used, the solubility of the liquid crystal material is insufficient, or even if there is a possibility that the support film described below may be eroded, by mixing and using two or more types of solvents, This disadvantage can be avoided. Among the above solvents, preferred as a single solvent are 2-pyrrolidone, amide solvents such as N-methyl-2-pyrrolidone,
Halogen-based solvents such as dichloroethane, tetrachloroethane, chlorobenzene, and orthodichlorobenzene, and the mixed solvent medium is preferably phenol, p-
A mixture of a phenol such as chlorophenol and a halogen-based solvent such as tetrachloroethane can be exemplified. The concentration of the solution cannot be specified unconditionally because it depends on the solubility of the liquid crystal material, the thickness of the finally obtained liquid crystal film, and the like, but is usually 1 to 60% by weight, preferably 3 to 40% by weight.
Is adjusted within the range. A surfactant or the like can be added to the solution of the liquid crystal material to facilitate application. Examples of surfactants that can be added include cationic surfactants such as imidazoline, quaternary ammonium salts, alkylamine oxides and polyamine derivatives, polyoxyethylene-polyoxypropylene condensates, primary and secondary surfactants. Alcohol ethoxylate, alkylphenol ethoxylate, polyethylene glycol and its ester, sodium lauryl sulfate, ammonium lauryl sulfate, amine lauryl sulfate, alkyl-substituted aromatic sulfonate, alkyl phosphate, aliphatic or aromatic sulfonate formalin condensate, etc. Anionic surfactants, amphoteric surfactants such as laurylamidopropyl betaine and laurylaminoacetate betaine, and nonionic surfactants such as polyethylene glycol fatty acid esters and polyoxyethylene alkylamine Surfactant, perfluoroalkyl sulfonate, perfluoroalkylcarboxylate, perfluoroalkylethylene oxide adduct, perfluoroalkyltrimethylammonium salt, oligomer containing perfluoroalkyl group / hydrophilic group, perfluoroalkyl group / lipophilic group Oligomers Containing Fluorinated surfactants such as perfluoroalkyl group-containing urethanes. The amount of the surfactant to be added depends on the type of the surfactant, the type of the liquid crystal material, the type of the solvent, and the type of the support film to which the solution is applied.
0 wt ppm to 10 wt%, preferably 100 wt pp
m to 5% by weight, more preferably 0.1 to 1% by weight.

[0012] Support film, support substrate and arrangement thereon
The solution of the liquid crystal material for imparting function is applied on a support film or a substrate. As the support film, for example, polyimide, polyamide imide, polyamide, polyether imide, polyether ether ketone, polyether ketone, polyketone sulfide, polyether sulfone, polysulfone, polyphenylene sulfide, polyphenylene oxide, polyethylene terephthalate, polybutylene terephthalate, Plastic films such as polyethylene naphthalate, polyacetal, polycarbonate, polyarylate, acrylic resin, polyvinyl alcohol, polypropylene, cellulose, triacetyl cellulose and partially saponified products thereof, epoxy resin and phenol resin can be used. These plastic films may be laminated films obtained by laminating two or more kinds of films, or may be uniaxially stretched or biaxially stretched films. Further, the support film can be subjected to a surface treatment such as a hydrophilic treatment or a hydrophobic treatment in advance. Depending on the composition of the liquid crystal material contained in the solution, it is not necessary to separately impart alignment ability to the support film, but in the present invention, it is desirable to impart alignment ability to the support film prior to application of the solution. The orientation ability can be imparted by laminating an orientation film on the support film or by rubbing the support film or the orientation film laminated thereon. Alternatively, silicon oxide may be obliquely vapor-deposited on the support film to impart orientation ability. As the alignment film, a film formed of polyimide, polyamide, polyvinyl alcohol, or the like is usually used, and the rubbing treatment is performed by winding a rubbing cloth selected from materials such as rayon, cotton, and polyamide on a metal roll, and applying this to a film. A method in which the film surface or the alignment film surface is rubbed with a rubbing cloth is usually adopted by rotating the film in a contact state or by transporting the film while fixing the roll. Instead of the above-described support film, a metal substrate such as aluminum, iron, or copper having a slit-shaped groove on the surface, or a glass substrate such as an alkali glass, a borosilicate glass, or a flint glass, whose surface is etched into a slit shape. It can also be used.

The application of the solution and the application of the solution to the dried support film or the support substrate can be arbitrarily adopted by a spin coating method, a roll coating method, a printing method, a dipping pulling method, a curtain coating method (die coating method), or the like. is there. The coating layer is then dried to evaporate the solvent in the coating layer. To dry the coating layer, air drying at room temperature, drying on a hot plate, drying in a drying oven, blowing of hot air or hot air, etc. are used, and the degree of drying is such that the coating layer flows, It does not need to run off. Depending on the composition of the liquid crystal material contained in the coating layer, the desired liquid crystal alignment may be formed at this stage at the temperature at which the solvent is removed, or thermotropically at the process of removing the solvent. May be completed, and no further alignment treatment may be required. However, it is necessary to perform a heat treatment on the dried coating film layer after the drying step in order to make the alignment of the liquid crystal more complete and, if necessary, to carry out a crosslinking reaction or the like. The orientation of the dried coating layer is formed by heating the liquid crystal material forming the coating layer above the liquid crystal transition point to a liquid crystal state, maintaining this state for a predetermined time, and heating the liquid crystal material to a higher temperature than the liquid crystal transition point. After the composition is brought into an isotropic liquid state, the temperature is lowered to a liquid crystal state, and a method of maintaining this state for a predetermined time can be used for the heat treatment of the dried coating layer. The heat treatment temperature required for forming the orientation of the dried coating layer depends on the type and composition of the liquid crystalline polymer and cannot be unconditionally determined, but is usually in the temperature range of 30 ° C to 220 ° C and 50 ° C to 50 ° C. 1
A range of 80 ° C is preferable, and a range of 60 ° C to 160 ° C is more preferable. The heat treatment time depends on the heat treatment temperature and the type of liquid crystalline polymer or non-liquid crystalline polymer contained in the coating layer, but is usually 5 seconds to 2 hours, preferably 10 seconds to 4 hours.
0 minutes, particularly preferably 20 seconds to 20 minutes. If the heat treatment time is less than 5 seconds, the orientation may not be formed sufficiently. If the time exceeds 2 hours, the productivity becomes extremely low, which is not desirable. Note that this heat treatment is an operation performed for the purpose of forming a liquid crystal material into a monodominous liquid crystal alignment state. However, since the liquid crystal material of the present invention contains a non-liquid crystalline polymer, A phase separation phenomenon occurs without being compatible with the hydrophilic polymer, and a polydomain state composed of two regions of a liquid crystal region and a non-liquid crystal region (isotropic region) can also be obtained. This polydomain state depends on the types of liquid crystalline polymer and non-liquid crystalline polymer, their mixing ratio,
Also, since it depends on the film thickness, heat treatment temperature, time, etc., it cannot be said unconditionally, but in general, an isotropic phase in a liquid crystal phase, or a liquid crystal phase in an isotropic phase is spherical, pseudo-spherical or pseudo-cylindrical. (A shape when the film is observed from above) can be formed in a polydomain state. In the present invention, a liquid crystal film obtained by forming the above-mentioned polydomain state by heat treatment and fixing the state is also included in the present invention. After the heat treatment, it is cooled if necessary.
The cooling operation is not particularly limited. For example, the cooling operation may be performed by transferring from a heat treatment atmosphere required for forming an orientation to room temperature and allowing it to cool. If necessary, the cooling operation may be performed using water cooling or other forced cooling means. By this cooling operation, the liquid crystal alignment state formed by the liquid crystal material is fixed, and the liquid crystal film of the present invention can be obtained. The actual thickness of the liquid crystal film (the layer made of a liquid crystal material) is not particularly limited, but is usually 0.1 to 20 in terms of mass productivity and a manufacturing process.
μm, preferably 0.2 to 10 μm, more preferably 0.4 to 6 μm. If the actual thickness of the liquid crystal film is less than 0.1 μm, the optical characteristics of the liquid crystal layer may not be sufficiently obtained. If it exceeds 20 μm, it cannot be said that it is desirable from the viewpoint of orientation and mass productivity.

Transfer of Liquid Crystal Film to Another Substrate The liquid crystal film of the present invention obtained as described above can be transferred to another substrate (hereinafter referred to as “second substrate”) as necessary. In addition, a surface treatment or the like for improving various resistances can be appropriately applied to the liquid crystal film. The transfer to the second substrate is performed when the support film or the support substrate used in obtaining the liquid crystal film or the alignment film or the like has optical performance that impairs the effects of the present invention. This is effective when it is desired to transfer the liquid crystal film to a thinner supporting substrate due to restrictions on the thickness and the like. Usually, the liquid crystal film can be transferred to the second substrate via a viscous / adhesive agent. As the second substrate, a sheet shape, a film shape,
It is not particularly limited as long as it has a shape such as a plate shape, for example, polyimide, polyamide imide, polyamide, polyether imide, polyether ether ketone, polyether ketone, polyketone sulfide,
Polyether sulfone, polysulfone, polyphenylene sulfide, polyphenylene oxide, polyvinyl chloride, polystyrene, polypropylene, polymethyl methacrylate, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polycarbonate, polyvinyl alcohol, polyacetal, polyarylate, cellulose-based plastics And a sheet, film or substrate of epoxy resin, phenol resin or the like, or paper such as paper or synthetic paper, metal foil, glass plate, or the like. Further, the substrate may contain a pigment such as a colored pigment or a dye, or the substrate may have an uneven surface. Adhesives / adhesives used for transfer are not particularly limited, and various conventionally known adhesives / adhesives, for example, light or electron beam-curable reactive adhesives, hot melt adhesives and the like can be used. It can be used as appropriate. As the reactive adhesive, a prepolymer and / or a monomer having photo- or electron beam polymerizability, if necessary, other monofunctional or polyfunctional monomers, various polymers, a stabilizer, a photopolymerization initiator,
What mixed a sensitizer etc. can be used. Specific examples of the prepolymer having photo- or electron-beam polymerizability include polyester acrylate, polyester methacrylate, polyurethane acrylate, polyurethane methacrylate, epoxy acrylate, epoxy methacrylate, polyol acrylate, and polyol methacrylate. Monomers having photo- or electron beam polymerizability include monofunctional acrylates, monofunctional methacrylates, difunctional acrylates, difunctional methacrylates, trifunctional or higher polyfunctional acrylates,
Examples thereof include polyfunctional methacrylates. In addition, commercially available products can also be used, for example, Aronix (acrylic special monomer or oligomer; manufactured by Toagosei Co., Ltd.), light ester (manufactured by Kyoeisha Chemical Co., Ltd.), biscoat (manufactured by Osaka Organic Chemical Industry), or the like. it can. As the photopolymerization initiator, for example, benzophenone derivatives, acetophenone derivatives, benzoin derivatives, thioxanthones, Michler's ketone, benzyl derivatives, triazine derivatives, acylphosphine oxides, azo compounds and the like can be used. The viscosity of the light- or electron-beam-curable reactive adhesive is appropriately selected depending on the processing temperature of the adhesive and cannot be unconditionally determined.
2000 mPa · s, preferably 50 to 1000 mPa · s
s, more preferably 100 to 500 mPa · s. When the viscosity is lower than 10 mPa · s, it becomes difficult to obtain a desired thickness. On the other hand, if it is higher than 2000 mPa · s, the workability may decrease, which is not desirable. When the viscosity is out of the above range, it is preferable to appropriately adjust the solvent and the monomer ratio to obtain a desired viscosity.
When a photocurable reactive adhesive is used, a known curing method such as a low-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a metal halide lamp, or a xenon lamp can be used as a method for curing the adhesive. . Further, the exposure amount cannot be determined unconditionally because it differs depending on the type of the reactive adhesive to be used, but is usually 50 to 2000 mJ / cm ² ,
Preferably it is 100 to 1000 mJ / cm ² . When an electron beam-curable reactive adhesive is used, the method for curing the adhesive is appropriately selected depending on the penetrating power and the curing power of the electron beam, and cannot be specified unconditionally. Voltage is 50-1000 kV, preferably 100-50
It can be cured by irradiation under the condition of 0 kV. When a hot-melt adhesive is used as the adhesive, the adhesive is not particularly limited.
Those having a temperature of 0 to 200 ° C, preferably about 100 to 160 ° C, are desirably used from the viewpoint of workability and the like. Specifically, for example, polyvinyl acetal resins such as ethylene-vinyl acetate copolymer resins, polyester resins, polyurethane resins, polyamide resins, thermoplastic rubbers, polyacrylic resins, polyvinyl alcohol resins, and polyvinyl butyral And those manufactured using petroleum-based resins, terpene-based resins, rosin-based resins, and the like as base resins. Further, the use of an adhesive as an adhesive is not particularly limited. For example, a rubber-based, acrylic, silicone-based, or polyvinyl ether-based adhesive can be used. The thickness of the viscous / adhesive varies depending on the intended use, its workability, and the like, and cannot be unconditionally determined. The method for forming the tacky / adhesive is not particularly limited. For example, a roll coating method, a die coating method, a bar coating method, a curtain coating method, an extrusion coating method, a gravure roll coating method, a spray coating method , Using a known method such as spin coating.
On the substrate and / or the liquid crystal film surface. The method of laminating the liquid crystal film of the present invention and the second substrate via a viscous / adhesive layer is not particularly limited. For example, an alignment support substrate / liquid crystal film / adhesive layer / second substrate Can be obtained. Next, the alignment support substrate is removed from the liquid crystal film, and a laminate composed of a liquid crystal film / adhesive layer / second substrate in this order can be obtained.

The method of removing the alignment support substrate from the liquid crystal film is not particularly limited, and examples thereof include a method of peeling and removing the alignment support substrate and a method of dissolving the alignment support substrate. As the peeling removal method, for example, a method of applying an adhesive tape to the corner end of the orientation support substrate to artificially peel it off, a method of mechanically peeling using a roll or the like, and a method of immersing in a poor solvent for all structural materials Mechanical peeling method, method of peeling by applying ultrasonic wave in poor solvent, method of peeling by giving temperature change using difference in thermal expansion coefficient between alignment support substrate and liquid crystal layer, alignment support substrate itself Or a method of dissolving and removing the alignment film on the alignment support substrate. The releasability differs depending on the physical properties of the liquid crystal material forming the liquid crystal film and the adhesion to the alignment support substrate, and thus a method most suitable for the system may be employed. In the present invention, a protective layer may be formed on the surface of the obtained liquid crystal film for the purpose of protecting the surface, increasing the strength, and improving environmental reliability. As the protective layer, ultraviolet absorption and / or
The material is not particularly limited as long as it has a hard coat property. For example, a material in which a protective layer-forming material containing an ultraviolet absorber and a hard coat agent is formed into a film, a sheet, a thin film, or a plate. In addition, a protective layer having an ultraviolet absorbing property made of a protective layer forming material containing an ultraviolet absorbing agent (hereinafter referred to as an ultraviolet absorbing layer)
A laminate of a protective layer having a hard coat property and a protective layer formed of a protective layer forming material containing a hard coat agent (hereinafter, a hard coat layer) may be used as the protective layer in the present invention. In addition, a laminate of a commercially available ultraviolet cut film and a hard coat film can be used as the protective layer. A laminate formed by applying various hard coat agents to the ultraviolet absorbing layer to form a film can also be used as the protective layer. Here, each of the ultraviolet absorbing layer and the hard coat layer may be formed of two or more layers, and each layer can be laminated via an adhesive layer or the like. As the material for forming the protective layer, a material having high light transmittance is desirable. For example, polyethylene, polypropylene, poly (4-
Methyl-pentene-1), polystyrene, ionomer, polyvinyl chloride, polymethyl methacrylate, polyethylene terephthalate, polyamide, polysulfone, cellulose resin, and the like, to which an ultraviolet absorber and / or a hard coat agent is added can be used. .
Further, as the protective layer, an adhesive composition obtained by adding an ultraviolet absorber and / or a hard coat agent to a heat, light or electron beam curing type reactive adhesive can be used, and a cured product of the adhesive composition can be used. Can be used as a protective layer. The ultraviolet absorber is not particularly limited as long as it is compatible or dispersible in the protective layer forming material, and examples thereof include a benzophenone compound, a salicylate compound, a benzotriazole compound, an oxalic anilide compound, and a cyanoacrylate compound. Organic UV absorbers, cesium oxide,
An inorganic ultraviolet absorber such as titanium oxide or zinc oxide can be used. Among them, a benzophenone-based compound having high ultraviolet absorption efficiency is preferably used. In addition, one or more ultraviolet absorbers can be added. The blending ratio of the ultraviolet absorber in the protective layer varies depending on the protective layer forming material used, but is usually 0.1 to 20% by weight, preferably 0.5 to 10% by weight. The hard coating agent is not particularly limited as long as it is compatible or dispersible in the protective layer forming material.
An inorganic compound such as a photo-curable resin-based acrylic oligomer, a urethane acrylate-based, an epoxy acrylate-based, a polyester acrylate-based, or a thermosetting resin-based acryl-silicon-based or ceramics can be used. Above all, an organopolysiloxane-based or photo-curable resin-based acrylic oligomer-based hard coat agent is preferably used from the viewpoint of film-forming properties and the like. These hard coat agents can be used either in a solventless type or a solvent type. In the protective layer forming material, in addition to an ultraviolet absorber and a hard coat agent, if necessary, a light stabilizer such as a hindered amine or a quencher, an antistatic agent, a slipperiness improver, a dye, a pigment, a surfactant, a fine Various additives such as fillers such as silica and zirconia can also be blended. The mixing ratio of these various additives is not particularly limited as long as the effects of the present invention are not impaired.
It is from 0.01 to 10% by weight, preferably from 0.05 to 5% by weight. Further, the ultraviolet absorbing layer constituting the protective layer can be formed by using a material obtained by appropriately blending an ultraviolet absorbing agent and, if necessary, a light stabilizer or the like into the protective layer forming material described above. Further, a commercially available ultraviolet cut film or the like can be used as the ultraviolet absorbing layer in the present invention.
The hard coat layer constituting the protective layer can be formed by using the above-described protective layer forming material and a hard coat agent, and optionally various additives. The hard coat layer may be formed by applying the above hard coat agent on a transparent support film. Examples of the transparent support film include films formed from polymethyl methacrylate, polystyrene, polycarbonate, polyether sulfone, polyphenylene sulfide, amorphous polyolefin, triacetyl cellulose, polyethylene terephthalate, polyethylene naphthalate, and the like. The ultraviolet absorbing layer and the hard coat layer are laminated via an adhesive or the like, and can be used as the protective layer in the present invention. As the adhesive, a heat, light or electron beam curable reactive adhesive or the like can be used. The protective layer can also be formed by using an adhesive containing an ultraviolet absorber and laminating a separately prepared hard coat layer on the liquid crystal film. Further, a dye, a pigment, a surfactant and the like may be appropriately added to the adhesive as needed. Further, as the hard coat layer, a vehicle resin for gravure ink or the like can be suitably used. Examples of the gravure ink vehicle resin include nitrocellulose, ethyl cellulose, polyamide resin, vinyl chloride, chlorinated polyolefin, acrylic resin, polyurethane, polyester, and the like. In addition, hard resins such as ester gum, dammar gum, maleic resin, alkyd resin, phenol resin, ketone resin, xylene resin, terpene resin, petroleum resin, etc. are used in the gravure ink vehicle resin in order to improve adhesion and film strength. May be blended. The configuration of the hard coat layer can be a single hard coat layer or a composite layer according to the required weather resistance and the like. As the composite layer, for example, a hard coat layer containing an organopolysiloxane, a hard coat layer containing a photocurable resin, a hard coat layer containing a thermosetting resin, a hard coat layer containing an inorganic compound, and the like are combined to form two layers. The composite layer composed of the above can be used as a hard coat layer. Further, the degree of the hard coat property, that is, the hardness cannot be unconditionally determined by the material constituting the liquid crystal film.
When the evaluation is carried out according to the test method described in IS L0849, it is desirable that the criterion for discoloration is at least 3 or more, preferably 4 or more. The protective layer formed on the liquid crystal film, the method of forming the ultraviolet absorbing layer and the hard coat layer constituting the protective layer is usually a roll coating method,
Known methods such as a dipping method, a gravure coating method, a bar code method, a spin coating method, a spray coating method, and a printing method can be employed. After forming a film on the liquid crystal surface of the liquid crystal film or the support film by these methods, a protective layer can be formed by performing a post-treatment according to the protective layer forming material used. Examples of a method for forming a protective layer composed of a composite layer of an ultraviolet absorbing layer and a hard coat layer include a method of directly applying and forming a hard coating agent on the ultraviolet absorbing layer, a method of laminating via an adhesive or the like, and the like. . The thickness of the protective layer cannot be determined unconditionally because it differs depending on the performance required for each of the ultraviolet absorbing property and the hard coat property, but is usually 0.1 to 100 μm,
Preferably it is 1 to 50 μm. Also, when the protective layer is formed of a composite layer with an ultraviolet absorbing layer and a hard coat layer, the total thickness of each layer is preferably within the above range.

The liquid crystal film of the present invention thus obtained is a laminate or a bonded body more stable against external force than the conventional liquid crystal film, and therefore has a very wide range of applications, and various optical elements and optoelectronics. It can be used as an element, a decorative member, an element for preventing forgery, and the like. Specific examples of optical elements and optoelectronic elements include transparent and isotropic films, for example, triacetylcellulose films such as Fujitac (manufactured by Fuji Photo Film Co., Ltd.) and Konikatac (manufactured by Konica Corporation), and TPX films (Mitsui Chemicals). Various optical applications by obtaining liquid crystal films using, as a second substrate, Arton film (manufactured by Nippon Synthetic Rubber Co., Ltd.), ZEONEX film (manufactured by Nippon Zeon), acrylene film (manufactured by Mitsubishi Rayon), etc. It is possible to expand to Specifically, the liquid crystal film having a fixed cholesteric orientation obtained by the present invention can provide various liquid crystal displays in which the film is provided in a liquid crystal display to improve the brightness of a backlight and prevent reflection on the display surface. Can be. A liquid crystal film having a fixed cholesteric orientation can be used as an optical filter or a circularly polarizing plate, or a linear polarizing plate can be obtained by combining with a quarter-wave plate. Further, by using a liquid crystal film having a phase separation structure of a cholesteric liquid crystal phase and an isotropic phase, the optical element can be used as an optical element having the above-described optical element further provided with light diffusing ability and light scattering ability. As the decorative member, various design molding materials including a new design film by vivid coloration effect by cholesteric liquid crystal can be obtained. Further, the liquid crystal film of the present invention has remarkably improved polymer cohesion as compared with the conventional cholesteric liquid crystal film. Therefore, even if it is a thin film, it can greatly contribute to the differentiation from other similar products by a method such as sticking it to an existing product or integrating it.
For example, the liquid crystal film of the present invention in which the cholesteric orientation is fixed is attached to a glass window or the like, or a glass window or the like is used as a second substrate at the time of transfer, so that the selective reflection characteristic of the cholesteric liquid crystal from the outside depends on the viewing angle. Will look different colors and will be excellent in fashion. In addition, it is possible to provide a window in which the inside is hardly seen from the bright outside, and the outside is excellent in the interior from the inside. Further, the liquid crystal film of the present invention, in particular, a liquid crystal film in which cholesteric orientation is fixed is suitable as a forgery prevention element such as a forgery prevention film, a seal, or a label. Anti-counterfeiting elements are often used when external force is applied during use, so they are applications where the mechanical strength of the liquid crystal film itself is required.However, the liquid crystal film of the present invention has cohesive failure, peel resistance, etc. Because of its excellent mechanical strength, it is possible to eliminate problems such as peeling and falling off from the bonding target. Here, examples of the bonding target include a card substrate such as a car driver's license, an identification card, a passport, a credit card, a prepaid card, various cash vouchers, a gift card, and securities, and a mount.
These card substrates and mounts, and the liquid crystal film of the present invention in which the cholesteric orientation is fixed are integrally or partially provided, specifically, affixed, embedded, or woven into paper to obtain a forgery prevention element. it can. In addition, the optical characteristics of cholesteric liquid crystals cannot be duplicated by a color copying machine, and are therefore very suitable for forgery prevention. These uses are only examples, and the liquid crystal film obtained by the present invention can increase the cohesive force of the liquid crystal layer while maintaining the unique optical characteristics inherent to the liquid crystal.
Its industrial value is extremely high, for example, it can be applied to various uses other than the above-mentioned uses.

[0017]

The following examples are provided to specifically illustrate the invention.
The present invention is not limited to this. When measuring the weight average molecular weight Mw of the polymer, the retention time was measured using a GPC measuring device, and the polymer was compared with a calibration curve of retention time vs. Mw using a previously prepared polystyrene standard sample, whereby the polystyrene of the polymer was measured. The converted Mw was calculated. The GPC measurement uses tetrahydrofuran as an elution solvent, and a Tosoh GPC analyzer CCP & 8000 (CP-800) equipped with a packed column for high-speed GPC (TSKgel G-1000HXL).
0, CO-8000, UV-8000). Example 1 4,4'-biphenyldicarbonyl chloride 0.45
mol, terephthaloyl chloride 0.055 mol,
0.25 mol of methylhydroquinone, 0.1 catechol
0 mol and 0.15 mol of hexamethylene glycol were reacted in o-dichlorobenzene at 80 ° C. for 3 hours, and the reaction solution was poured into methanol with stirring to perform a reprecipitation operation to obtain a white polymer. The obtained polymer was separated by filtration, washed with methanol, and dried under vacuum to obtain a liquid crystal polyester (liquid crystal polymer 1, Mw = 7500). PerkinElmer D
The glass transition temperature of the liquid crystal polymer 1 measured by SC-7 was 46 ° C. 10 g of liquid crystal polymer 1
It was weighed and dissolved in 90 g of tetrachloroethane to prepare a liquid crystal polymer solution (solution 1). 5 g of cellulose triacetate (Aldrich reagent) pellets
g of tetrachloroethane under heating with stirring to obtain a highly viscous solution (solution 2). 40 g of the solution 1 was weighed into a screw tube, 20 g of the solution 2 was added thereto, and the mixture was stirred at room temperature for about 1 hour until the mixture became uniform to obtain a solution 3.
The weight composition ratio of liquid crystal / non-liquid crystal in the solution 3 is 4/1. A polyimide solution (SE-5291 manufactured by Nissan Chemical Industries, Ltd.) is applied to a 1.1 mm-thick soda lime glass by a roll coater, and the solvent is dried.
A μm polyimide layer was formed. The polyimide surface of the glass plate with the polyimide layer was subjected to a rubbing treatment with a rayon rubbing cloth, and a solution 3 was applied on the surface by spin coating. Then, after sufficiently drying in an oven at 65 ° C., it was placed in an oven at 120 ° C. and heat-treated for 10 minutes. Thereafter, the glass plate was taken out of the oven and put into water to be rapidly cooled. When the obtained sample was observed with a polarizing microscope, a sea-island domain in which a liquid crystal phase and an isotropic phase were separated was observed, and a liquid crystal phase having a diameter of several μm was seen in the isotropic phase. When attention is paid to the liquid crystal phase, a uniform nematic liquid crystal phase is fixed in almost domains uniaxially oriented in the rubbing direction, and the average in-plane retardation measured by a Berek compensator is 135 nm.
When the film thickness of the liquid crystal phase portion of the sample was measured with a stylus type film thickness meter, it was 1.2 μm (Sample 1). Example 2 Liquid crystal polymer A represented by the following formula obtained by a melt polymerization method
(Mw = 6500), 7.8 g of a liquid crystal polymer B (Mw
= 4700) and 0.6 g of a benzoguanamine derivative SB-303 manufactured by Sanwa Chemical Co., Ltd.
Dissolved in 61.4 g of N-methyl-2-pyrrolidone. To the solution was added 0.5 mg of a fluorine-based surfactant S-383 (manufactured by Asahi Glass) to prepare Solution 4. Polymethyl methacrylate (Aldrich reagent, weight average molecular weight about 35
5.6 g of the compound (1) was weighed, 74.4 g of N-methyl-2-pyrrolidone was added thereto, and the mixture was stirred under heating to obtain a polymer solution 5. Solution 4 and solution 5 were mixed 1: 1 by weight to obtain solution 6. The weight composition ratio of liquid crystal / non-liquid crystal in the solution 6 is 2/1. The surface was coated on a polyethylene naphthalate (PEN) film rubbed with a rayon cloth using a bar coater. After the application, the film is put into a clean oven set at 80 ° C., dried for 15 minutes, and then heat-treated in an oven set at 180 ° C. for 15 minutes, so that the cholesteric orientation of the liquid crystal layer, liquid crystal / non-liquid crystal And the thermal crosslinking reaction of benzoguanamine were simultaneously completed (Sample 2). Liquid crystal polymer A

Embedded image Liquid crystal polymer B

Embedded image The cholesteric liquid crystal portion and the polymethyl methacrylate portion in the liquid crystal layer after the alignment treatment are both glass-fixed, and a small amount of the liquid crystal layer was scraped off from the PEN film and subjected to DSC measurement. And 95 ° C. Sample 2 clearly shows green selectively reflected light even from the front with the naked eye.
In addition, due to the phase separation, it did not have a perfect metallic luster, but had a slightly glossy matte luster. Observation with a polarizing microscope revealed that, like Sample 1 of Example 1,
Non-liquid crystal phase separation was confirmed, and the liquid crystal portion had a uniform cholesteric alignment. In the measurement of the sample 2 with a spectroscope (V-570 manufactured by JASCO Corporation), a well-type transmission spectrum characteristic of cholesteric selective reflection centering on 560 nm was obtained. When the cross section of the liquid crystal layer was observed with a transmission electron microscope, a sea-island structure was confirmed in the liquid crystal portion and the isotropic phase portion. In the liquid crystal portion, the helical axis direction was uniformly parallel to the film thickness direction, and the helical pitch was It was confirmed that cholesteric orientations were formed at regular intervals in the thickness direction, and that a resin having a uniform composition different from the liquid crystal was confirmed in the isotropic phase portion. A UV curable adhesive UV-3400 (manufactured by Toagosei Co., Ltd.) was applied to the liquid crystal layer surface of Sample 2 with a bar coater to a thickness of about 6 μm, and then an 80 μm-thick triacetyl cellulose film KC-80 (manufactured by Konica). Is laminated on the surface, and then the substrate PEN of the film laminate is laminated.
Light irradiation of 810 mJ was performed from the side by an ultraviolet irradiation device equipped with a metal halide lamp. By this operation, U
The V-curable adhesive was almost completely cured. After that, the liquid crystal layer was transferred to the triacetyl cellulose film by disposing the triacetyl cellulose film side of the film laminate along the tabletop and gently peeling only the PEN film 180 degrees from the laminate (sample 3). ).
Sample 3 was not different from Sample 2 in optical properties at all, and it was confirmed by visual observation and measurement by a spectroscope that the cholesteric alignment structure and the phase separation structure were almost unchanged. Example 3 On the liquid crystal layer surface after peeling off the PEN film of Sample 3 prepared in Example 2, the UV-curable adhesive UV-
3400 was applied again, a triacetyl cellulose film (KC-80) was laminated in the same manner as in Example 2, and the adhesive was cured by irradiation with ultraviolet rays. A liquid crystal film sample (sample 4) supported by two triacetyl cellulose films was obtained. Sample 4 was 3 cm wide,
When cut into strips of 15 cm length and tearing the film by holding the upper and lower triacetyl cellulose films, cohesive failure occurs inside the liquid crystal layer, and the liquid crystal fragments are left on the upper and lower triacetyl cellulose films respectively. Was presented. In order to measure the peel strength of the film as it was, the peel strength was measured with a tensile tester (Strograph EL, manufactured by Toyo Seiki Seisaku-sho, Ltd.) using the already peeled portions of the upper and lower triacetyl cellulose films as a handle. A load cell with a maximum load of 5 kgf was used for the measurement, and one triacetyl cellulose film handle was fixed to the lower part, and the other end was pulled upward at a peeling speed of 300 mm / min. The tensile strength was measured while supporting the support. The average of the obtained values was calculated, and the film width (3c
The peel strength of sample 4 was 62 when the peel strength of m) was calculated by converting the peel strength per inch (about 2.54 cm).
gf / inch. Comparative Example 1 A liquid crystal thin film was formed and heat-treated in the same manner as in Example 2 except that only the liquid crystal polymer solution 4 was used instead of the solution 6 in which the liquid crystal polymer solution 4 was mixed with the non-liquid crystal polymer solution 5. Then, a transfer operation was performed to obtain a sample 5. Sample 5 was a monodomain cholesteric liquid crystal film, and did not have a phase-separated structure as in Sample 3 of Example 2 and exhibited a metallic-like luster. Further, similarly to Sample 3, a well-type transmittance spectrum centered on 560 nm and unique to the cholesteric alignment structure was obtained by the spectroscope. Sample 5 was sandwiched between triacetyl cellulose films in the same manner as in Example 3 to prepare Sample 6, and the peel strength of Sample 6 was measured in the same manner as in Example 3. The peel strength of Sample 6 was 12 gf / inch. Was. Example 4 The following three types of acrylate monomers M1 to M3 were synthesized.

Embedded image These M1, M2, M3 and acrylic acid were mixed at a ratio of 50: 20: 30: 0.5 (weight ratio) to form a chlorobenzene solution, and oxygen gas was deaerated by bubbling nitrogen gas. Thereafter, azobisisobutyronitrile (AIBN) is weighed out at 2 wt% of the monomer weight,
After the chlorobenzene solution was added, the solution was added to the monomer solution. Thereafter, the reactor was heated to 80 ° C. and reacted for 3 hours. Then, 1 wt% of AIBN was again added as a solution and reacted at 80 ° C. for 6 hours. The obtained reaction solution was poured into a 9-fold amount of diethyl ether, a reprecipitation operation was performed, and the obtained precipitate was dissolved again in chloroform and then precipitated again in diethyl ether. After the obtained precipitate was thoroughly washed with diethyl ether, it was dried for 24 hours with a vacuum drier. GPC analysis of the obtained polymer was performed. The GPC analysis was performed using tetrahydrofuran as an elution solvent and using a TSKgel G-1 packed column for high-speed GPC.
GPC Analyzer CCP equipped with 000HXL
& 8000 (CP-8000, CO-8000, UV-
8000). The resulting polymer has Mw = 7
000 polymers. When the obtained polymer was analyzed by DSC (DSC7, manufactured by PerkinElmer), the glass transition temperature Tg was 70 ° C. The obtained polymer was examined for liquid crystal phase behavior using a Mettler hot stage and an Olympus polarizing microscope.
A nematic phase flowing around 0 ° C. was collected, and an oily streak characteristic of a cholesteric liquid crystal phase was partially observed. The isotropic transition temperature of this polymer was around 240 to 250 ° C. By the same procedure, a benzyl methacrylate monomer (manufactured by Tokyo Chemical Industry) was polymerized to obtain a poly (benzyl methacrylate) polymer. Mw of the obtained poly (benzyl methacrylate) =
It was 900,000. The poly (benzyl methacrylate) did not show liquid crystallinity in a temperature range from room temperature to 300 ° C. An aqueous solution of polyvinyl alcohol (MP-203, manufactured by Kuraray Co., Ltd.) is applied onto a commercially available triacetyl cellulose film (UVD-80, manufactured by Fuji Photo Film Co., Ltd.), and dried to form a thin film. The polyvinyl alcohol surface of the film is rubbed with a rayon cloth. An oriented substrate was prepared. A 12 wt% tetrachloroethane solution of a mixture of 10 g of the liquid crystal polymer synthesized above and 0.5 g of poly (benzyl methacrylate) is applied onto the alignment substrate by spin coating, and dried on a hot plate at 65 ° C. for 30 minutes. 2.2 μm
Was formed. The thickness of the liquid crystal layer was measured by a stylus type thickness gauge. This film was subjected to a heat treatment in an oven set at 120 ° C. for 10 minutes to obtain a liquid crystal film sample 7. When sample 7 was observed with a polarizing microscope, it was found that the cholesteric orientation of a clean monodomain was clear, and selective reflection derived from the cholesteric orientation was observed in the vicinity of green in the visible light region even to the naked eye, and poly (benzyl methacrylate) was compatible with the liquid crystal. Was confirmed. When the transmittance spectrum of Sample 7 was measured with a spectroscope (V-570, manufactured by JASCO Corporation), 510 nm to 580 n
In the vicinity of m, a well-type transmittance reduction region derived from selective reflection was confirmed. Example 5 Sample 7 prepared in Example 4 was laminated again with a triacetylcellulose film via an adhesive in the same manner as in Examples 2 and 3, and then irradiated with ultraviolet rays to laminate the film with the triacetylcellulose film. Sample 8 was obtained. When a peel test was performed on Sample 8 in the same manner as in Example 3, interfacial peeling occurred between the liquid crystal layer and the polyvinyl alcohol layer of the alignment film applied to the triacetyl cellulose film used as the alignment support substrate, The cohesion of the liquid crystal layer could not be measured. Therefore, the triacetyl cellulose film used as the support substrate of Sample 8 and the alignment film layer were peeled off and removed, and the remaining liquid crystal surface was again coated with an ultraviolet curable adhesive (UV-3400). Sample 9 was laminated with a cellulose film and irradiated with ultraviolet light to prepare Sample 9 supported by a triacetyl cellulose film. When the peel strength of Sample 9 was measured in the same manner as in Example 3, cohesive failure occurred inside the liquid crystal layer, and the peel strength at that time was 56 g.
f / inch. Comparative Example 2 A liquid crystal film sample 10 was obtained in the same manner as in Example 4 except that poly (benzyl methacrylate) was not added. Sample 10 showed the property of a cholesteric liquid crystal film similarly to Sample 7 of Example 4, and the selective reflection wavelength was 500 to 560 nm as measured by a spectroscope. Using Sample 10, a sample 11 supported by a triacetyl cellulose film whose peel strength can be measured in the same manner as in Example 5 was prepared,
The peel strength was measured in the same manner as in Example 5. As a result, the sample 11 was found to undergo cohesive failure inside the liquid crystal layer by the measurement, and the peel strength at that time was 19 gf / inch.

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Ryo Nishimura 8 Chidori-cho, Naka-ku, Yokohama-shi, Kanagawa Prefecture Nishiishi Mitsui Co., Ltd. Central Research Laboratory F-term (reference) 4F071 AA09 AA33 AA44 AA51 AA54 AA60 AA63 AF12 BC01 4H027 BA01 BA02 BA11 BA12 BB11 BD24 BE06 4J002 AB011 AB012 BB032 BB122 BC032 BE022 BE062 BG032 BG062 CF031 CF062 CF082 CH001 CK002 CL001 CL002 CM041 CM042 CN021 CP031

Claims (5)

[Claims] 1. A liquid crystalline polymer having a weight average molecular weight of 100
A liquid crystal material containing at least 00 non-liquid crystalline polymer. 2. The liquid crystal material according to claim 1, wherein the non-liquid crystalline polymer is a methyl methacrylate polymer and / or a copolymer thereof. 3. The liquid crystal material according to claim 1, wherein the liquid crystalline polymer exhibits nematic or cholesteric liquid crystal properties. 4. A liquid crystalline polymer having a weight average molecular weight of 100
A liquid crystal film formed from a liquid crystal material containing at least 00 non-liquid crystalline polymer. 5. The liquid crystal film according to claim 4, wherein the liquid crystal film maintains cholesteric alignment.