JP2000347027A - Transferring element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transferring element comprising a new liquid crystalline film of which the diffracted rays themselves produce specified polarized light such as circularly polarized light or linearly polarized light. SOLUTION: The transferring element is a laminated body at least comprising a supporting substrate, a cholesteric liquid crystal layer and an adhesive layer, of which the cholesteric liquid crystal layer is made of a film material containing a polymer liquid crystal with 1,000-100,000 weight-average molecular weight (Mw) measured with GPC (expressed in terms of polystyrene), <=5 molecular-weight distribution (Mw/Mn; Mn expresses the number-average molecular weight), 0.05-2.0 logarithmic viscosity number (0.5 g/dl concentration in the phenol-tetrachloroethane mixed solvent (60/40 weight ratio) at 30 deg.C), <=200 deg.C glass transition temperature (Tg) and >=40 deg.C transition temperature (Ti) from a liquid crystal phase to an isotropic phase as the indispensable constituent, and at least comprises a cholesteric liquid crystal film having a region exhibiting diffractiveness at least on a part of it.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transfer element capable of transferring a cholesteric liquid crystal film capable of generating diffracted light having a polarization property.

[0002]

2. Description of the Related Art A diffractive element is a general-purpose optical element that is widely used in the field of spectral optics and the like for the purpose of splitting light and splitting a light beam. Diffraction elements are classified into several types based on their shape.Amplitude type diffraction elements, in which light-transmitting and non-light-transmitting parts are periodically arranged, are phase-type, in which periodic grooves are formed in a highly transparent material. It is usually classified as a diffraction element. Further, they may be classified as a transmission type diffraction element or a reflection type diffraction element according to the direction in which diffracted light is generated.

In the above-described conventional diffraction element, only non-polarized light can be obtained as diffracted light obtained when natural light (non-polarized light) is incident. Polarizing optical instruments such as ellipsometers, which are frequently used in the field of spectroscopy, can only obtain non-polarized light as diffracted light. In general, a method of using diffracted light through a polarizer in order to use only the polarized light component is used.
In this method, there is a problem that about 50% or more of the obtained diffracted light is absorbed by the polarizer, so that the amount of light is reduced by half. For that purpose, it is necessary to prepare a detector having a high sensitivity and a light source having a large amount of light, and the development of a diffraction element in which the diffracted light itself becomes a specific polarized light such as a circularly polarized light or a linearly polarized light has been required.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and makes it easy to control the liquid crystal layer structure by using a polymer liquid crystal having specific physical properties as a film material. We succeeded in providing a region showing diffractive power to a part of the liquid crystal layer. In addition, by using the polymer liquid crystal, it is possible to easily transfer a cholesteric liquid crystal film having a new optical property called polarization diffraction to an object to be transferred without causing alignment disorder or cracking in the film after alignment control. The inventors have invented a transfer element capable of performing the above-mentioned.

[0005]

That is, the present invention relates to a laminate comprising at least a support substrate / a cholesteric liquid crystal layer / an adhesive layer, wherein the cholesteric liquid crystal layer has a G layer.
Weight average molecular weight M measured by PC (polystyrene conversion)
w is 1000 to 100,000, molecular weight distribution (Mw / Mn; Mn
Has a number average molecular weight of 5 or less and a logarithmic viscosity of 0.05 to 2.
0 (phenol / tetrachloroethane (weight ratio 60/4)
0) Concentration of 0.5 g / dl (temperature 30
C)), a film material containing a polymer liquid crystal having a glass transition temperature (Tg) of 200 ° C. or less and a transition temperature (Ti) from a liquid crystal phase to an isotropic phase of 40 ° C. or more as an essential component, and at least The present invention relates to a transfer element at least composed of a cholesteric liquid crystal film partially having a region exhibiting a diffraction ability.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be specifically described below. The optical laminate of the present invention comprises at least a support substrate / cholesteric liquid crystal layer / adhesive layer. Here, the term “support substrate / cholesteric liquid crystal layer / adhesive layer” means a configuration in which a support substrate, a cholesteric liquid crystal layer, and an adhesive layer are laminated in this order. Note that an intermediate layer may be provided between the support substrate and the cholesteric liquid crystal layer,
For example, an adhesive layer, a release layer, or the like can be used as the intermediate layer. Hereinafter, components of the present invention will be described in order.

The support substrate, which is a component of the present invention, functions as a support for the cholesteric liquid crystal layer. After the cholesteric liquid crystal layer has been transferred to the object to be transferred,
The support substrate is separated and removed. As a supporting substrate having such a function, 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, polyethylene naphthalate, polyacetal, polycarbonate, polyarylate, acrylic resin, epoxy resin, phenolic resin, polyvinyl alcohol, cellulosic plastics, polyethylene,
Plastic films and sheets formed of a chain or alicyclic polyolefin such as polypropylene, poly (4-methyl-1-pentene), norbornene-based resin, and the like are included. As the support substrate, various alignment support substrates that can be used when forming a cholesteric liquid crystal film described later can be used as they are.

As the supporting substrate, a plastic film or sheet having a surface treated with silicon or the like, or an acrylic resin, a methacrylic resin, an epoxy resin, or a paraffin-based wax may be used as the supporting substrate. it can. Further, a plastic film or sheet serving as a support substrate that has been subjected to physical deformation treatment such as embossing, hydrophilic treatment, hydrophobic treatment, or the like may be used as a support substrate which is a component of the present invention. it can.

The thickness of the supporting substrate is usually 8 to 200 μm,
Preferably from 15 to 150 μm, more preferably from 20 to
100 μm. If the thickness is less than 8 μm, the handling properties of the obtained transfer element may be deteriorated. If the thickness is larger than 200 μm, the peeling transfer operation may not be performed smoothly. Note that the support substrate is removed when the cholesteric liquid crystal layer is transferred to the transfer target, and the separation interface is usually between the interface between the support substrate and the protective layer.

Next, the cholesteric liquid crystal layer which is a component of the present invention has a weight average molecular weight Mw of 1,000 to 100,000 measured by GPC (polystyrene conversion) and a molecular weight distribution (Mw / Mn; Mn is a number average molecular weight) of 5 Hereinafter, the logarithmic viscosity is 0.05 to 2.0 (concentration: 0.5 g in a phenol / tetrachloroethane (weight ratio: 60/40) mixed solvent).
/ Dl (temperature 30 ° C)) and a glass transition temperature (Tg) of 2
100 ° C. or less, and the transition temperature from the liquid crystal phase to the isotropic phase (T
i) is composed of a film material containing, as an essential component, a polymer liquid crystal having a temperature of 40 ° C. or higher, and is at least composed of a cholesteric liquid crystal film having a region exhibiting diffractive ability in a part of the film. Here, the region exhibiting the diffractive power means a region which produces an effect such that the light transmitted through the region or the light reflected by the region wraps around a portion which is geometrically shadow. The presence or absence of a region having a diffractive ability is confirmed by, for example, the presence or absence of light (higher-order light) emitted at a certain angle other than light (0th-order light) that enters a laser beam or the like into the aforementioned region and transmits or reflects linearly. can do. Alternatively, whether or not the region is formed can be confirmed by observing the surface shape or cross-sectional shape of the liquid crystal layer using an atomic force microscope, a transmission electron microscope, or the like.

[0011] The region exhibiting diffraction ability may be any region on the film surface and / or inside the film,
For example, it may be provided on a part of the film surface (film surface region) or on a part of the inside of the film (film inner region). In addition, the region may be provided in a plurality of regions of the cholesteric liquid crystal film, for example, a film front and back surface region and a plurality of film internal regions. Further, the region exhibiting diffractive power is not necessarily required to be formed as a layer having a uniform thickness on the film surface or inside, for example, and the region is formed on at least a part of the film surface or inside the film. It should just be. For example, the region having the diffraction power may have a shape such as a desired figure, pictogram, or numeral. Further, when there are a plurality of regions exhibiting diffractive power, it is not necessary that all the regions exhibit the same diffractive power, and each region may exhibit a different diffractive power. The orientation state of the region exhibiting diffractive power is such that the helical axis orientation is not uniformly parallel to the film thickness direction, preferably the helical axis orientation is not uniformly parallel to the film thickness direction, and the helical pitch is the film pitch. It is desirable to form a cholesteric alignment that is not uniformly spaced in the thickness direction. In other regions, a helical structure in which the helical axis orientation is uniformly parallel to the film thickness direction and the helical pitch is uniformly spaced uniformly in the film thickness direction is the same as the normal cholesteric orientation. It is desirable to form. In the present invention, the film surface means a portion of the cholesteric liquid crystal film alone which comes into contact with the outside, and the inside of the film means a portion other than the portion which comes into contact with the outside.

In the present invention, any of the above-mentioned cholesteric liquid crystal films can be used, but from the viewpoint of the film production method, the method of imparting diffractive power, etc., at least a part of the film surface region, preferably the entire surface of the film surface region. A cholesteric liquid crystal film having a region exhibiting a diffractive power is suitably used. Also, when having a region exhibiting diffractive power in one film surface region, the front and back of the film, that is, a film surface having a region exhibiting diffractive power and a slightly different optical effect from the opposite film surface,
Since it shows a coloration effect and the like, it is possible to select which film surface is to be on the protective layer side constituting the optical laminate of the present invention in accordance with the use and the intended function. Further, when the region showing the diffraction ability is formed in a layer state,
The thickness of the layer (region) exhibiting the diffractive ability is usually 50% or less, preferably 30% or less, more preferably 10% or less with respect to the thickness of the cholesteric liquid crystal film. It is desirable. When the thickness of the layer (region) exhibiting the diffractive ability exceeds 50%, the effects of the present invention such as selective reflection characteristics and circular polarization characteristics due to the cholesteric liquid crystal phase are reduced, and the effect of the present invention may not be obtained. .

The cholesteric liquid crystal film as described above has a weight average molecular weight Mw of 1,000 to 100,000 measured by GPC (polystyrene conversion) and a molecular weight distribution (Mw / M
n; Mn is 5 or less, and the logarithmic viscosity is 0.0
5 to 2.0 (concentration 0.5 g / dl (temperature 30 ° C) in a phenol / tetrachloroethane (weight ratio 60/40) mixed solvent), a glass transition temperature (Tg) of 200 ° C or less, and isotropic from the liquid crystal phase. Phase transition temperature (Ti) of 40
It can be formed by transferring a diffraction pattern of a diffraction element substrate to a cholesteric alignment film made of a film material containing a high-molecular liquid crystal having a temperature of not less than ° C as an essential component. If the weight average molecular weight (Mw) of the polymer liquid crystal measured by GPC (in terms of polystyrene) is less than 1,000, the resulting cholesteric alignment film has low mechanical strength, which is not desirable in various post-treatment steps and practical performance.
Further, when transferring a diffraction pattern described later, there is a possibility that a diffraction pattern that can withstand practicality may not be transferred. On the other hand, if it exceeds 100,000, the flowability of the liquid crystal deteriorates, which may adversely affect the orientation, and the film may be broken or cracked when a diffraction pattern is transferred. On the other hand, if the molecular weight distribution exceeds 5, the meltability in producing a cholesteric alignment film and the solubility in a solution become poor, and uniform orientation to a cholesteric phase is difficult to obtain, which may pose a practical problem. In addition, when the diffraction pattern is transferred, the film may be cracked or cracked.

If the logarithmic viscosity is less than 0.05, the mechanical strength of the cholesteric alignment film may be low, which is not desirable in various post-processes and practical performance. Further, when transferring the diffraction pattern, there is a possibility that the transfer cannot be performed to a degree that can withstand practicality. On the other hand, if it exceeds 2.0, the flowability of the liquid crystal deteriorates, and it may be difficult to obtain a uniform orientation to the cholesteric phase. Further, when a diffraction pattern is transferred, the film may be cracked or cracked. Further, when the glass transition temperature (Tg) is higher than 200 ° C., the fluidity in the liquid crystal state is poor, and it may be difficult to obtain uniform alignment,
Further, if necessary, there is a possibility that a problem that it is difficult to select an alignment support substrate used at the time of alignment may also occur. Further, when the transition temperature (Ti) from the liquid crystal phase to the isotropic phase is lower than 40 ° C., the alignment stability of the cholesteric alignment film near room temperature may be deteriorated. This is undesirable because the pattern may be damaged.

The polymer liquid crystal used in the present invention is not particularly limited as long as it satisfies the above-mentioned various physical properties, and any of a main chain type and a side chain type polymer liquid crystal may be used. Can be. Specific examples include main-chain liquid crystal polymers such as polyester, polyamide, polycarbonate, and polyesterimide, and side-chain liquid crystal polymers such as polyacrylate, polymethacrylate, polymalonate, and polysiloxane. Among them, a liquid crystalline polyester which has good orientation in forming cholesteric orientation and is relatively easy to synthesize is desirable. Preferred examples of the constituent unit of the polymer include an aromatic or aliphatic diol unit, an aromatic or aliphatic dicarboxylic acid unit, and an aromatic or aliphatic hydroxycarboxylic acid unit.

In order to improve the heat resistance and the like of the obtained cholesteric liquid crystal film, a crosslinking agent such as a bisazide compound or glycidyl methacrylate may be added to the film material as long as the cholesteric phase is not impaired. By adding these cross-linking agents, cross-linking can be performed while a cholesteric phase is developed. Further, in the film material, dichroic dye,
Various additives such as dyes and pigments may be appropriately added as long as the effects of the present invention are not impaired.

The cholesteric liquid crystal film constituting the cholesteric liquid crystal layer, which is a component of the present invention, is obtained by developing the above-mentioned film material on an alignment support substrate,
After fixing the orientation to obtain a cholesteric orientation film,
It can be obtained by transferring the diffraction pattern of the diffraction element substrate.

The alignment support substrate used for obtaining the cholesteric alignment film before transferring the diffraction pattern includes, for example, a glass substrate or a plastic film,
A plastic substrate such as a plastic sheet can be exemplified. As a glass substrate, for example, soda glass,
A silica-coated soda glass, a borosilicate glass substrate, or the like can be used. Also, as a plastic substrate,
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, polyethylene naphthalate, polyacetal, Polycarbonate,
Cellulose plastics such as polyarylate, acrylic resin, epoxy resin, phenol resin, polyvinyl alcohol, and triacetyl cellulose; and chain or alicyclic resins such as polypropylene, poly (4-methyl-1-pentene), norbornene-based resin Polyolefin and the like can be used. A uniaxial or biaxial stretching operation can be appropriately applied to these alignment support substrates as needed. Further, the substrate may be subjected to a surface treatment such as a hydrophilization treatment, a hydrophobization treatment, and an easy peeling treatment. In addition, as the alignment support substrate, one type alone or a laminate of two or more types of substrates can be used as the alignment support substrate.

In the present invention, an alignment film formed on each of the above-mentioned alignment support substrates is also included in the alignment support substrate. As the alignment film, a rubbed polyimide film is suitably used, but other alignment films known in the art can also be used as appropriate. Also, a plastic substrate or the like obtained by directly imparting an orientation ability by a rubbing treatment without applying polyimide or the like can be used as an orientation support substrate when obtaining a cholesteric orientation film. The method of the alignment treatment is not particularly limited, but any method may be used as long as the liquid crystal molecules are uniformly aligned in parallel with the alignment treatment interface.

Next, as a method of spreading the film material on the alignment supporting substrate, there are a melt coating and a solution coating.

In the solution application, a film material is dissolved at a predetermined ratio in a solvent to prepare a solution having a predetermined concentration. As the solvent, although it varies depending on the type of film material to be used, usually, hydrocarbons such as toluene, xylene, butylbenzene, tetrahydronaphthalene, and decahydronaphthalene, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, propylene glycol dimethyl ether, ether such as tetrahydrofuran, Ketones such as methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, ethyl acetate, butyl acetate, ethylene glycol monomethyl ether acetate, propylene glycol monomethyl ether acetate, ethyl lactate, γ
-Esters such as butyrolactone, amides such as N-methyl-2-pyrrolidone, dimethylformamide and dimethylacetamide, halogenated hydrocarbons such as dichloromethane, carbon tetrachloride, tetrachloroethane and chlorobenzene, butyl alcohol, triethylene glycol, Alcohols such as diacetone alcohol and hexylene glycol can be used. If necessary, two or more of these solvents can be used as a mixture. The concentration of the solution depends on the molecular weight and solubility of the polymer liquid crystal used,
Further, since it depends on the final film thickness of the target film and the like, it cannot be said unconditionally, but it is usually 1 to 60% by weight, preferably 3 to 40% by weight.

Further, a surfactant or the like may be added to the solution to facilitate application. Examples of the surfactant include cationic surfactants such as imidazoline, quaternary ammonium salts, alkylamine oxides, and polyamine derivatives, polyoxyethylene-polyoxypropylene condensates, primary and secondary alcohol ethoxylates. , Alkylphenol ethoxylates, polyethylene glycols and esters thereof, sodium lauryl sulfate, ammonium lauryl sulfate, lauryl sulfate amines, alkyl-substituted aromatic sulfonates, alkyl phosphates, aliphatic or aromatic sulfonic acid formalin condensates, etc. Surfactants, amphoteric surfactants such as lauryl amide propyl betaine and lauryl amino acetate betaine, and nonionic surfactants such as polyethylene glycol fatty acid esters and polyoxyethylene alkylamine , Perfluoroalkyl sulfonate, perfluoroalkyl carboxylate, perfluoroalkyl ethylene oxide adduct, perfluoroalkyl trimethyl ammonium salt, perfluoroalkyl / hydrophilic group-containing oligomer, perfluoroalkyl / lipophilic group-containing oligomer Fluorinated surfactants such as fluoroalkyl group-containing urethanes and the like are included. The amount of the surfactant to be added depends on the type of the surfactant, the solvent, and the supporting substrate to be coated.
The range is 0 ppm to 10%, preferably 50 ppm to 5%, and more preferably 0.01% to 1%.

The film material solution prepared as described above is applied on an alignment support substrate. Examples of the application method include a roll coating method, a die coating method, a bar coating method, a gravure roll coating method, a spray coating method, a dip coating method, and a spin coating method.

After the application, the solvent is removed by drying, and a heat treatment is performed at a predetermined temperature for a predetermined time to give a cholesteric liquid crystal phase, thereby completing cholesteric alignment. Next, the cholesteric alignment film formed in the liquid crystal state is rapidly cooled to a temperature equal to or lower than the glass transition point of the polymer liquid crystal, whereby a cholesteric alignment film in which the cholesteric alignment is fixed can be obtained.

The thickness of the cholesteric alignment film is not particularly limited, but is usually 0.3 to 20 μm, preferably 0.5 to 1 in view of mass productivity and the production process.
0 μm, and more preferably 0.7 to 3 μm. The number of spiral windings in the cholesteric orientation is usually 2 or more and 10 or less, preferably 2 or more and 6 or less. If the number of spiral windings is less than 2 or more than 10, the effect as a polarization diffraction element may not be exhibited.

The cholesteric alignment film obtained as described above was bonded to the diffraction pattern surface of the diffraction element substrate, and at least part of the film was provided with a region exhibiting diffractive ability by applying heat and / or pressure. A cholesteric liquid crystal film can be obtained.

The material of the diffraction element substrate used for transferring the diffraction pattern may be a material such as a metal or a resin, a material having a diffraction function on the film surface, or a thin film having a diffraction function on the film. Any material may be used as long as it has a diffractive function, such as a material obtained by transferring the same. Above all, in view of ease of handling and mass productivity, a film or a film laminate having a diffraction function is more desirable.

The term "diffraction element" used herein includes, as its definition, all diffraction elements that generate diffracted light, such as an original flat hologram. The type may be a diffraction element derived from the surface shape, a so-called film thickness modulation hologram type, or a phase element independent of the surface shape or a surface shape converted into a refractive index distribution, a so-called refraction. A rate modulation hologram type may be used. In the present invention, the type of the film thickness modulation hologram is more preferably used because the diffraction pattern information of the diffraction element can be more easily given to the liquid crystal. In addition, any type of refractive index modulation can be suitably used in the present invention as long as it has undulations that cause diffraction in the surface shape.

As a method for transferring a diffraction pattern, for example, generally used heat rollers, laminators,
Using a hot stamp, an electric heating plate, a thermal head, or the like, the heating can be performed under heating and / or pressure conditions. The heating and pressurizing conditions differ depending on various physical properties of the polymer liquid crystal used, the type of the diffraction element substrate, and the like, and cannot be unconditionally determined. 0.1 to 100 MPa, preferably 0.0
It is appropriately selected depending on the type of liquid crystal, substrate, and the like used in the range of 5 to 80 MPa.

The structure of the cholesteric liquid crystal layer, which is a component of the present invention, usually comprises one layer of the cholesteric liquid crystal film obtained by the above method. In addition, a configuration in which a plurality of cholesteric liquid crystal films are laminated in accordance with the application and required optical characteristics, etc., or a cholesteric liquid crystal film having one layer or a plurality of layers and a cholesteric alignment film having no diffractive region or one layer. A configuration in which a plurality of layers are stacked may be employed. When two or more cholesteric liquid crystal films and cholesteric alignment films having no diffractive area are laminated, two or more cholesteric liquid crystal films and cholesteric alignment films may be alternately laminated.

The thickness of the cholesteric liquid crystal layer is usually 0.1.
It is 3 to 20 μm, preferably 0.5 to 10 μm, and more preferably 0.7 to 3 μm. If the ratio is out of this range, the effects of the present invention may not be effectively exhibited. When the film is composed of a plurality of layers, it is desirable that the total thickness of all the films falls within the above range.

The adhesive layer, which is a component of the present invention, is formed for the purpose of bonding between the object to be transferred and the cholesteric liquid crystal layer. The adhesive layer is not particularly limited, and various conventionally known adhesives and adhesives, specifically, a hot-melt adhesive, a light or electron beam-curable reactive adhesive, or the like may be appropriately used. Can be. Among them, a hot-melt adhesive is preferably used in the present invention from the viewpoint of workability during transfer.

The hot melt type adhesive is not particularly limited, but the working temperature of the hot melt is 250 ° C. or lower, preferably 80 to 200 ° C., more preferably 100 to 16 ° C.
Those having a temperature of about 0 ° 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 A hot melt adhesive having a base resin of petroleum resin, terpene resin, rosin resin or the like can be used.

As the reactive adhesive, a prepolymer and / or monomer having photo- or electron-beam polymerizability, if necessary, other monofunctional monomers, polyfunctional monomers, various polymers, stabilizers, photopolymerizable Those containing an initiator, a sensitizer and the like can be used.

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. . Examples of the monomer having photo- or electron beam polymerizability include monofunctional acrylate, monofunctional methacrylate, difunctional acrylate, difunctional methacrylate, trifunctional or higher polyfunctional acrylate, and polyfunctional methacrylate. These can also use a commercial item, for example, Aronix (acrylic special monomer, oligomer;
Toagosei Co., Ltd.), Light Ester (Kyoeisha Chemical Co., Ltd.),
Viscote (manufactured by Osaka Organic Chemical Industry) or the like can be used.

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 which can be used in the present invention is appropriately selected depending on the processing temperature of the adhesive and cannot be unconditionally determined. ~ 2000 mPa · s, preferably 50
１０００1000 mPa · s, more preferably 100 to 50
0 mPa · s. When the viscosity is lower than 10 mPa · s, it becomes difficult to obtain a desired thickness. 2000mP
If it is higher than a · 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 photo-curing 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, a xenon lamp, or the like is used as a method for curing the adhesive. be able to. Although the exposure amount cannot be determined unconditionally because it differs depending on the type of the reactive adhesive used, it is usually 50 to 2000 mJ.
/ Cm ² , preferably 100 to 1000 mJ / cm ² .

When an electron beam-curable reactive adhesive is used, the method of curing the adhesive is appropriately selected depending on the penetrating power and the curing power of the electron beam, and cannot be determined unconditionally. Usually, curing can be carried out by irradiating under an acceleration voltage of 50 to 1000 kV, preferably 100 to 500 kV.

Further, the use of a pressure-sensitive adhesive as the adhesive layer in the present invention is not particularly limited. For example, a rubber-based, acrylic, silicone-, or polyvinyl ether-based pressure-sensitive adhesive can be used. The thickness of the adhesive layer varies depending on the application to be used and its workability and cannot be unconditionally determined, but is usually 0.5 to 50 μm, preferably 1 to 10 μm.

The method of forming the adhesive layer varies depending on the method of manufacturing a transfer element to be described later. 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, and the like. It can be formed on a cholesteric liquid crystal layer or the like by using a known method such as a coating method, a spray coating method, and a spin coating method. The formation of the adhesive layer may be performed immediately before the transfer, or the adhesive layer is formed in advance before the transfer, and is stored by a method such as laminating release paper or the like on the adhesive layer. It is also possible to keep.

An intermediate layer can be provided between the cholesteric liquid crystal layer and the support substrate constituting the transfer element of the present invention. Examples of the intermediate layer include an adhesive layer, a release layer, and a protective layer.

The adhesive layer is not particularly limited. For example, the above-described light or electron beam-curable reactive adhesive can be used as appropriate. The release layer can be formed of, for example, wax, silicone, a fluorine-based release agent, or the like, which exhibits fluidity by heat.

By providing a protective layer as an intermediate layer, effects such as surface protection, strength increase and environmental reliability of the cholesteric liquid crystal film after transfer can be obtained. The purpose of the protective layer is to protect the cholesteric liquid crystal layer after the cholesteric liquid crystal layer has been transferred to the transfer object. The protective layer is not particularly limited as long as it has an ultraviolet absorbing property and / or 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. Further, a protective layer having an ultraviolet absorbing property made of a protective layer forming material containing an ultraviolet absorbent (hereinafter, referred to as an ultraviolet absorbing layer) and a protective layer having a hard coating property made of a protective layer forming material containing a hard coat agent (Hereinafter, a hard coat layer) may be used as a protective layer. 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, those having high light transmittance are desirable. For example, polyethylene, polypropylene, poly (4-methyl-pentene-1), polystyrene, ionomer, polyvinyl chloride, polymethyl methacrylate, polyethylene terephthalate, polyamide,
A material obtained by adding an ultraviolet absorber and / or a hard coat agent to polysulfone, a cellulose resin, or the like 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.

Between the support substrate and the cholesteric liquid crystal layer constituting the transfer element of the present invention, two layers of an adhesive layer and a release layer, and three layers of an adhesive layer, a release layer and a protective layer are provided. It can also be configured as an intermediate layer. In the case where an intermediate layer is provided, a peeling interface between the transfer element and the supporting substrate when the transfer element is transferred is an interface with the intermediate layer. Further, without providing a protective layer as an intermediate layer, the protective layer can be formed directly on the surface of the cholesteric liquid crystal film after transfer. The protective layer is not particularly limited as long as it has an ultraviolet absorbing property and / or a hard coating property as described above.

The method for manufacturing the transfer element of the present invention includes:
(1) Laminate sequentially on a support substrate to have the configuration of the present invention. (2) Press, heat, and cure the remaining laminate separately manufactured on a support substrate having an adhesive layer formed on the surface in advance. (3)
Prepare the remaining laminated body separately prepared on the support substrate on the peelable substrate, remove the peelable substrate by transferring to the support substrate side by means of pressure, heating, curing, etc. alone or in combination. A method of forming an adhesive layer on a cholesteric liquid crystal layer serving as an outer layer.

As a more specific example of the production method, (1) forming an adhesive layer on a cholesteric liquid crystal film layer formed on an alignment support substrate and a support substrate or a cholesteric liquid crystal film having an adhesive layer formed on the surface thereof in advance. And transferred to a support substrate, and the alignment support substrate is peeled off. Next, a method of forming an adhesive layer on the cholesteric liquid crystal film layer, (2) transferring the cholesteric liquid crystal film formed on the alignment support substrate onto a second substrate different from the alignment support substrate via the adhesive layer Then, the alignment support substrate is peeled off. Next, an adhesive layer is formed on a support substrate or a cholesteric liquid crystal film on which an adhesive layer has been formed in advance, and the cholesteric liquid crystal film is transferred to the support substrate.
A method of forming an adhesive layer on the cholesteric liquid crystal film after peeling and removing only the second substrate from the cholesteric liquid crystal film, and (3) a method of forming the cholesteric liquid crystal film formed on the alignment support substrate on the second substrate different from the alignment support substrate. It is transferred to a substrate via an adhesive layer, and the alignment support substrate is peeled off. Next, the cholesteric liquid crystal film is transferred onto the third substrate via the adhesive layer, and the second substrate is peeled off. Next, a method of transferring the cholesteric liquid crystal film to a support substrate on which an adhesive layer has been formed in advance, peeling and removing the third substrate, and then forming an adhesive layer on the cholesteric liquid crystal film can be used.

Here, the second and third substrates (hereinafter, referred to as “substrate”)
It is called a removable substrate. ) Is not particularly limited as long as it is a substrate having removability and self-supporting property, and a plastic film having releasability is usually desirably used as the substrate. The term "removability" as used herein means that, when the cholesteric liquid crystal film and the removable substrate are bonded via an adhesive, the releasability can be removed at the interface between the adhesive layer and the removable substrate. Specific examples of the material for such a removable substrate include olefin-based resins such as polyethylene, polypropylene, and 4-methylpentene-1 resin, polyamide, polyimide, polyamideimide, polyetherimide, polyetherimide, and polyether. Ketone, polyether ether ketone, polyether sulfone, polyketone sulfide, polysulfone,
Examples include polystyrene, polyphenylene sulfide, polyphenylene oxide, polyethylene terephthalate, polybutylene terephthalate, polyarylate, polyacetal, polycarbonate, polyvinyl alcohol, and cellulose-based plastic. A plastic film formed from these materials may use the plastic film itself as a removable substrate, or on a plastic film surface in order to have an appropriate removability,
Those coated with silicone or a fluorine-based resin, those formed with an organic thin film or inorganic thin film, those subjected to chemical treatment, and those subjected to physical treatment such as surface polishing for vapor deposition can also be used.

The adhesive used for transferring the cholesteric liquid crystal film to the removable substrate is not particularly limited, but is preferably a heat, light or electron beam-curable reaction described above. A suitable adhesive or the like can be used as appropriate.

Further, examples of the peeling and removing method in the above-mentioned manufacturing method include, for example, a method of applying an adhesive tape to a corner end of an alignment supporting substrate or a removable substrate and peeling it artificially.
A method of mechanically peeling using a roll or the like, a method of mechanically peeling after dipping in a poor solvent for all structural materials,
A method of exfoliating by applying ultrasonic waves in a poor solvent, an orientation substrate, a method of exfoliating by giving a temperature change using a difference in thermal expansion coefficient between a removable substrate and a cholesteric liquid crystal film, or the like may be appropriately adopted. it can. The above manufacturing method is merely an example, and the transfer element of the present invention is not limited thereto.

The transfer element of the present invention depends on the kind of the adhesive layer constituting the element. For example, polyimide, polyamideimide, polyamide, polyetherimide, polyetheretherketone, polyetherketone, polyketonesulfide , 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 plastic Sheet, film or various molded products of paper, epoxy resin, phenolic resin, etc., paper such as paper and synthetic paper, metal Easily from the supporting substrate without causing alignment disturbance or cracking the cholesteric liquid crystal layer for different transfer target such as glass, also it can be transcribed in a desired shape. When a hot-melt adhesive is used as the adhesive which is a component of the present invention, heating, pressing,
When a so-called hot stamping device capable of instantaneously applying an impact is used, a series of operations of transfer, peeling and removal can be performed simultaneously and instantaneously.

The transfer element of the present invention can transfer a cholesteric liquid crystal layer having a unique effect that a diffracted light has a circular polarization property, which is not possible with a conventional optical member, to an object to be transferred. Due to this unique effect, for example, by transferring the cholesteric liquid crystal layer to a spectroscopic optical device such as an ellipsometer that requires polarized light, the light use efficiency can be extremely increased. Conventional spectroscopic optical devices that require polarized light use a diffraction element such as a diffraction grating or prism to separate the light emitted from the light source for each wavelength and then transmit the light through the polarizer, or transmit the light through the polarizer and then separate the light. It was necessary to have a polarizer. This polarizer has a problem that it absorbs about 50% of the incident light and the reflection at the interface occurs, resulting in extremely low light utilization efficiency. By transferring the cholesteric liquid crystal layer to a desired portion, the light use efficiency is extremely high, and it is theoretically possible to use about 100%.

In the cholesteric liquid crystal layer constituting the transfer element of the present invention, transmission and blocking of diffracted light can be easily controlled by using an ordinary polarizing plate. Normally, diffracted light having no polarization cannot be completely blocked by any combination of polarizing plates. That is, in the cholesteric liquid crystal layer that is a component of the transfer element of the present invention, for example, diffracted light having right polarization can be completely blocked only when a left circular polarizer is used, and other polarizers can be used. Even if used, complete interruption cannot be realized. Due to such a unique effect, for example, in an environment where an observer observes a diffraction image through a polarizing plate, by changing the state of the polarizing plate, the diffraction image suddenly emerges from the dark field, or It can be eliminated.

As described above, the transfer element of the present invention can easily transfer a cholesteric liquid crystal layer to an object to be transferred, and the transferred cholesteric liquid crystal layer has a very wide application range as a new diffraction function element. Can be used as various optical elements, optoelectronic elements, decorative members, forgery prevention elements, and the like.

Specific examples of the optical element and the optoelectronic element include a transparent and isotropic film as a support substrate, for example, Fujitac (manufactured by Fuji Photo Film Co., Ltd.),
Triacetylcellulose films such as Konikatac (manufactured by Konica), TPX films (manufactured by Mitsui Chemicals, Inc.), Arton films (manufactured by Nippon Synthetic Rubber Co., Ltd.), Zeonex films (manufactured by Nippon Zeon), acrylene films (manufactured by Mitsubishi Rayon) The cholesteric liquid crystal layer is transferred by using the transfer element of the present invention to the above-mentioned method to obtain an optical laminate, which can be applied to various optical applications. For example, the optical laminated body is formed by TN (twisted nema).
tic) -LCD (Liquid Crystal D)
display), STN (Super Twisted)
Nematic) -LCD, ECB (Electri)
cally Controlled Birefrin
gence) -LCD, OMI (Optical Mo)
de Interference)-LCD, OCB
(Optically Compensated Bi
(refringence) -LCD, HAN (Hybr)
id Aligned Nematic) -LCD, I
PS (In Plane Switching) -LC
By providing a liquid crystal display such as D, various LCDs with improved color compensation and / or improved viewing angle can be obtained. Further, the optical laminate can be used as a spectroscopic optical device that requires polarized light separated as described above, a polarizing optical element that obtains a specific wavelength by a diffraction phenomenon, an optical filter, a circularly polarizing plate, a light diffusing plate, and the like. In addition, it is possible to provide various optical members that can exhibit an optical effect that has not existed conventionally as an optical element or an optoelectronic element, such as obtaining a linear polarizing plate by combining with a quarter-wave plate. .

As a decorative member, a cholesteric liquid crystal layer can be transferred to various products and the like as a new member having a combination of iridescent coloring effect by diffractive ability and colorful coloring effect by cholesteric liquid crystal. In addition, since the cholesteric liquid crystal layer can be easily transferred, it can be expected to greatly contribute to differentiation from other similar products by methods such as attachment to existing products and integration. For example, when the cholesteric liquid crystal layer of the present invention incorporating a diffractive pattern having a design is transferred to a glass window or the like, the selective reflection specific to the cholesteric liquid crystal with the diffraction pattern looks different from the outside depending on the viewing angle, It will be excellent in fashionability. 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.

The anti-counterfeit element can be used as a new anti-counterfeit film, seal, label, etc. having both the anti-counterfeit effect of the diffraction element and the cholesteric liquid crystal. Specifically, using the transfer element of the present invention, for example, a car driver's license, identification card, passport, credit card, prepaid card, various cash vouchers,
The cholesteric liquid crystal layer is integrated with or partially provided on the card substrate, the mount, etc. by transferring it to a card substrate, a mount, etc. of gift cards, securities, etc., specifically, attached, embedded, or woven into paper. be able to. Further, the cholesteric liquid crystal layer constituting the transfer element of the present invention has a region exhibiting diffractive power in a part of the cholesteric liquid crystal layer, and also has a wavelength-selective reflectivity, a circularly-polarized light selective reflectivity, and color It has both viewing angle dependence and the effect of exhibiting a beautiful cholesteric color. Therefore, when the cholesteric liquid crystal layer which is a component of the transfer element of the present invention is used as a forgery prevention element, it is extremely difficult to forge the cholesteric liquid crystal layer. In addition to the anti-counterfeiting effect, it also has an iridescent color effect of the diffraction element and a vivid color effect of the cholesteric liquid crystal, and thus has excellent design properties. From these facts, the cholesteric liquid crystal layer constituting the transfer element of the present invention is very useful as a forgery prevention element.

These applications are only examples, and the transfer element of the present invention can be used for various applications in which a single diffractive element or a single cholesteric liquid crystal film has been used, or can exhibit a new optical effect. Because it is possible, the cholesteric liquid crystal layer exhibiting its unique optical effect can be easily transferred to various applications other than the above-mentioned applications, and the liquid crystal layer can be transferred without disordered alignment, cracks, etc. Application development is possible in various applications.

[0060]

EXAMPLES Examples will be described below, but the present invention is not limited to these examples. Various measurement methods used in the present invention will be described.

(GPC Measurement Method) Tosoh GPC (CP8
000, CO8000, UV8000), TSKG3
A column having a configuration of 000HXL, G2000HXL, and G1000HXL was connected, and measurement was performed at 25 ° C. with a tetrahydrofuran (THF) solvent at a flow rate of 0.7 ml / min.
A calibration curve was separately prepared using standard polystyrene under the same conditions, and the weight average molecular weight Mw, number average molecular weight Mn, and molecular weight distribution Mw / Mn in terms of polystyrene were determined. (Measurement of glass transition temperature (Tg)) D manufactured by Du Pont
It was measured by SC990. (Measurement of transition temperature (Ti) from liquid crystal phase to isotropic phase) Polarizing microscope B manufactured by Olympus Corporation equipped with a hot stage
The measurement was performed at X50.

(Example 1) Mw is 3000, Mw / Mn
A film was formed by a spin coating method on a rubbed polyphenylene sulfide film of a liquid crystalline polyester (containing an R-form optically active compound) having a 2.0, logarithmic viscosity of 0.124, Tg of 80 ° C, and Ti of 230 ° C. Then 180 ° C
After heat treatment for 5 minutes, a film having a golden specular reflection was obtained.

When the transmission spectrum of the obtained film was measured with an ultraviolet-visible-near-infrared spectrophotometer V-570 manufactured by JASCO Corporation, a center wavelength of about 600 nm and a selective reflection wavelength bandwidth of about 100 nm were selected. It was confirmed that a cholesteric alignment film having a fixed cholesteric alignment exhibiting reflection was obtained.

Next, a ruled line diffraction grating film (900 / m) manufactured by Edmund Scientific Japan
m), so that the diffraction surface and the liquid crystal surface of the cholesteric alignment film face each other, and using a laminator DX-350 manufactured by Tokyo Laminex Co., Ltd., heat-presses at 120 ° C., 0.3 MPa and a roll contact time of 0.5 second. went. After cooling to room temperature, the diffraction grating film was removed.

When the cholesteric alignment film surface on which the diffraction grating film was superimposed was observed, the rainbow color caused by the diffraction pattern and the selective reflection characteristic of the cholesteric liquid crystal were clearly recognized. In addition, when the orientation state of the film surface from which the diffraction grating film was removed was observed by a polarizing microscope and a transmission electron microscope of the liquid crystal layer cross section, the helical axis orientation in the cholesteric phase was not uniformly parallel to the film thickness direction, and It was confirmed that cholesteric alignment in which the helical pitch was not uniformly spaced in the film thickness direction was formed in the surface region of the liquid crystal layer. In other regions, it was confirmed that a cholesteric orientation in which the helical axis orientation was uniformly parallel to the film thickness direction and the helical pitch was uniformly uniform in the film thickness direction was formed. The number of spiral turns of cholesteric orientation in this region was 4. Also, a He-Ne laser (wavelength 632.
8 nm), a laser beam was observed at an emission angle of 0 ° and about ± 35 °. In order to further confirm the polarization characteristics, the obtained laminate was placed under normal room illumination and observed through a right circularly polarizing plate (transmitting only right circularly polarized light). And the brightness when observed without a polarizing plate was almost the same. On the other hand, observation through a left circularly polarizing plate (transmitting only left circularly polarized light) revealed a dark field, and no iridescent reflected and diffracted light was observed.

From the above observation results, it was found that a cholesteric liquid crystal film having a region exhibiting diffractive ability could be formed on a polyphenylene sulfide film by transferring the diffraction surface of the diffraction grating film to a cholesteric alignment film. Next, a hot melt adhesive layer was formed on the cholesteric liquid crystal layer from which the diffraction grating film had been removed to obtain a transfer element. The obtained transfer element was
140 ° C. on a 0 cm square, 1 mm thick plastic sheet made of polyvinyl chloride using a hot stamping device.
Transcribed.

As a result, a 1 cm square cholesteric liquid crystal layer could be transferred to the right corner of the polyvinyl chloride sheet. The polyphenylene sulfide film used as the support substrate was separated from the cholesteric liquid crystal layer during hot stamping. The adhesive layer was firmly bonded to the polyvinyl chloride sheet. When light was applied to the cholesteric liquid crystal layer after transfer, bright selective reflection light and diffracted light were observed as in the case before transfer.

(Example 2) Mw is 7000, Mw / Mn
A film was formed by spin coating on polyphenylene sulfide rubbed with a liquid crystalline polyester (containing an R-form optically active compound) having a 2.0, logarithmic viscosity of 0.144, Tg of 85 ° C and Ti of 230 ° C. Then, when the film was heat-treated at 200 ° C. for 5 minutes, a film having a golden specular reflection was obtained.

When the transmission spectrum of the film was measured with an ultraviolet-visible-near-infrared spectrophotometer V-570 manufactured by JASCO Corporation, the selective reflection having a center wavelength of about 600 nm and a selective reflection wavelength bandwidth of about 100 nm was observed. It was confirmed that a film in which the cholesteric orientation shown was fixed was formed.

A laminator manufactured by Tokyo Laminex Co., Ltd. was overlapped so that the diffraction surface of the ruled line diffraction grating film (900 lines / mm) manufactured by Edmund Scientific Japan and the liquid crystal surface of the cholesteric alignment film obtained above faced each other. Using DX-350, 120 ° C, 0.3MP
a, Heating and pressurization was performed under the condition of a roll contact time of 0.5 seconds. After cooling to room temperature, the ruled line diffraction grating film was removed.

When the surface of the cholesteric liquid crystal film on which the diffraction grating film was superimposed was observed, rainbow colors caused by the diffraction pattern and selective reflection peculiar to the cholesteric liquid crystal were clearly recognized. In addition, when the orientation state of the film surface from which the diffraction grating film was removed was observed by a polarizing microscope and a transmission electron microscope of the liquid crystal layer cross section, the helical axis orientation in the cholesteric phase was not uniformly parallel to the film thickness direction, and It was confirmed that cholesteric alignment in which the helical pitch was not uniformly spaced in the film thickness direction was formed in the surface region of the liquid crystal layer. In other regions, it was confirmed that a cholesteric orientation in which the helical axis orientation was uniformly parallel to the film thickness direction and the helical pitch was uniformly uniform in the film thickness direction was formed. Also, a He-Ne laser (wavelength 632.8 n
m), laser light was observed at an emission angle of 0 ° and about ± 35 °. In order to further confirm the polarization characteristics, the obtained laminate was placed under normal room illumination and observed through a right circularly polarizing plate (transmitting only right circularly polarized light). And the brightness when observed without a polarizing plate was almost the same. On the other hand, observation through a left circularly polarizing plate (transmitting only left circularly polarized light) revealed a dark field, and no iridescent reflected and diffracted light was observed.

From the above observation results, it was found that a cholesteric liquid crystal film having a region exhibiting a diffractive ability could be formed on a polyphenylene sulfide film by transferring the diffraction surface of the diffraction grating film to a cholesteric alignment film.

A cholesteric liquid crystal surface of the obtained cholesteric liquid crystal film was coated with an adhesive made of a commercially available photocurable acrylic oligomer containing a hard coat agent to a thickness of 5 μm using a bar coater. Next, a polyethylene terephthalate film (support substrate) is attached to the application surface using a desktop laminator,
The adhesive was cured by irradiation with ultraviolet rays. After the adhesive was cured, the end of the polyphenylene sulfide film used as the alignment substrate was held by hand, and the polyphenylene sulfide film was peeled in the 180 ° direction at the interface with the cholesteric liquid crystal layer.

Next, a hot-melt adhesive layer was formed on the cholesteric liquid crystal surface from which the polyphenylene sulfide film had been removed, to produce a transfer element.

The transfer element was 10 cm square and 1 m thick.
m was transferred onto a polyvinyl chloride plastic sheet at 140 ° C. using a hot stamping device. As a result, a 1 cm square cholesteric liquid crystal layer could be transferred to the right corner of the polyvinyl chloride plastic sheet. The polyethylene terephthalate film used as the support substrate of the transfer element was peeled off from the cholesteric liquid crystal layer during hot stamping. The adhesive layer was firmly bonded to the polyvinyl chloride sheet.

After the transfer, when light was applied to the cholesteric liquid crystal layer, bright selective reflected light and diffracted light were observed as before the transfer. When the transfer element was used to transfer the cholesteric liquid crystal layer onto A4 size paper, the alignment of the cholesteric liquid crystal layer was disturbed or cracked in the same way as when the polyvinyl chloride sheet was used as the transfer object. The transfer was able to be performed without occurrence of blemishes. In the transferred cholesteric liquid crystal layer, bright selective reflected light and diffracted light were observed as in the case before the transfer.

Example 3 Mw is 7000, Mw / Mn
A film was formed by spin coating on polyphenylene sulfide rubbed with a liquid crystalline polyester (containing an R-form optically active compound) having a 2.0, logarithmic viscosity of 0.144, Tg of 85 ° C and Ti of 230 ° C. Then, when the film was heat-treated at 200 ° C. for 5 minutes, a film having a golden specular reflection was obtained.

When the transmission spectrum of this film was measured with an ultraviolet-visible-near-infrared spectrophotometer V-570 manufactured by JASCO Corporation, the selective reflection having a center wavelength of about 600 nm and a selective reflection wavelength bandwidth of about 100 nm was observed. It was confirmed that a film in which the cholesteric orientation shown was fixed was formed.

A laminator manufactured by Tokyo Laminex Co., Ltd. was overlapped so that the diffraction surface of the ruled line diffractive element film (900 lines / mm) manufactured by Edmund Scientific Japan and the liquid crystal surface of the cholesteric alignment film obtained above faced each other. Using DX-350, 120 ° C, 0.3MP
a, Heating and pressurization was performed under the condition of a roll contact time of 0.5 seconds. After cooling to room temperature, the ruled line diffraction grating film was removed.

When the surface of the cholesteric alignment film on which the diffraction grating film was superimposed was observed, iridescence caused by the diffraction pattern and selective reflection peculiar to the cholesteric liquid crystal were clearly recognized. In addition, when the orientation state of the film surface from which the diffraction grating film was removed was observed by a polarizing microscope and a transmission electron microscope of the liquid crystal layer cross section, the helical axis orientation in the cholesteric phase was not uniformly parallel to the film thickness direction, and It was confirmed that cholesteric alignment in which the helical pitch was not uniformly spaced in the film thickness direction was formed in the surface region of the liquid crystal layer. In other regions, it was confirmed that a cholesteric orientation in which the helical axis orientation was uniformly parallel to the film thickness direction and the helical pitch was uniformly uniform in the film thickness direction was formed. Also, a He-Ne laser (wavelength 632.8 n
m), laser light was observed at an emission angle of 0 ° and about ± 35 °. In order to further confirm the polarization characteristics, the obtained laminate was placed under normal room illumination and observed through a right circularly polarizing plate (transmitting only right circularly polarized light). And the brightness when observed without a polarizing plate was almost the same. On the other hand, observation through a left circularly polarizing plate (transmitting only left circularly polarized light) revealed a dark field, and no iridescent reflected and diffracted light was observed.

From the above observation results, it was found that a cholesteric liquid crystal film having a region exhibiting a diffractive ability could be formed on a polyphenylene sulfide film by transferring the diffraction surface of the diffraction grating film to a cholesteric alignment film.

Next, an adhesive layer made of an acrylic resin is formed on the film surface from which the diffraction grating film has been removed,
A transfer element was prepared. The obtained transfer element is 1 cm
It was cut into a corner size and bonded to a glass plate via an adhesive layer. Next, a cellophane tape was adhered to a polyphenylene sulfide film as a support substrate of the transfer element, and the polyphenylene sulfide film was peeled off. When light was applied to the cholesteric liquid crystal layer after transfer, diffracted light was observed simultaneously with the selectively reflected light. This also confirmed that the cholesteric liquid crystal layer had a diffractive ability. In addition, it was confirmed that the obtained transfer element could be similarly applied to transfer to a polyvinyl chloride sheet or paper.

Example 4 Using a cholesteric liquid crystal film having a region exhibiting diffractive ability on the polyphenylene sulfide film obtained in Example 3, an acrylic oligomer-based lipoxy SP-1509 was formed on the liquid crystal film surface.
5% by weight of Aerosil R812 (manufactured by Nippon Aerosil Co., Ltd.) and Irgacure 907 (trade name of Ciba Geigy) 3 as a photopolymerization initiator
A prototype UV-curable hard coat agent (isopropyl alcohol solution (solid content: 20% by weight)) to which a% by weight was added was applied by a bar coater to a thickness of 5 μm. Next, the surface is covered with a silicon-treated polyethylene terephthalate film, and the polyethylene terephthalate film is irradiated with ultraviolet light from a high-pressure mercury lamp to cure the hard coat agent (protective layer) and peel off the polyphenylene sulfide film. Removed. Further form a polyvinyl alcohol-based hot melt adhesive layer on this,
The transfer element was completed.

This transfer element was 10 cm square and 1 m thick.
Using a hot stamping device, a 1 cm square protective layer / cholesteric liquid crystal film / adhesive layer laminate was attempted to be transferred at 140 ° C. onto a polyvinyl chloride m plastic sheet. As a result, a 1 cm square laminate of the protective layer / cholesteric liquid crystal film / adhesive layer could be transferred to a polyvinyl chloride plastic sheet. The polyethylene terephthalate film as a support substrate of the transfer element was peeled off from the protective layer during hot stamping.
Further, the adhesive layer was firmly adhered to the polyvinyl chloride sheet. The cholesteric liquid crystal film after the transfer did not show any disorder in alignment or cracks.

Next, a friction resistance test of the laminate on the polyvinyl chloride sheet was performed by using a friction tester FR-I manufactured by Suga Test Instruments Co., Ltd.
Performed using a mold. As a test piece, the laminated body was fixed so that the protective layer was on the upper surface, a dry white cotton cloth was attached to the friction element, and a friction operation of 50 reciprocations was performed between 10 cm on the test piece for 50 seconds, and the film after the test was performed. When the protective layer was visually observed, almost no damage was found on the protective layer. The evaluation based on the criterion for discoloration was 4-5. Using this transfer element, an attempt was made to transfer the image onto A4 size paper. As in the case where a polyvinyl chloride sheet was used as the transfer object, good transfer was performed.

Comparative Example 1 Mw is 950, Mw / Mn
2, logarithmic viscosity 0.06, Tg 60 ° C, Ti 220
° C liquid crystalline polyester (contains R-form optically active compound)
Was formed on a rubbed polyphenylene sulfide by spin coating. Subsequently, when heat-treated at 180 ° C. for 5 minutes, a film exhibiting a golden specular reflection was obtained. When the transmission spectrum of the film was measured with an ultraviolet-visible-near-infrared spectrophotometer V-570 manufactured by JASCO Corporation, a cholesteric orientation showing a selective reflection having a center wavelength of about 600 nm and a selective reflection wavelength bandwidth of about 100 nm was obtained. It was confirmed that a film in which was fixed was formed.

The laminator manufactured by Tokyo Laminex Co., Ltd. was overlapped so that the diffraction surface of the ruled-type diffraction grating film (900 lines / mm) manufactured by Edmund Scientific Japan and the liquid crystal surface of the cholesteric alignment film obtained above faced each other. Using DX-350, 120 ° C, 0.3MP
a, Heating and pressurization was performed under the condition of a roll contact time of 0.5 seconds. Next, after cooling to room temperature, the ruled line diffraction grating film was removed. In the obtained film, cracks occurred in a part of the film, and the cholesteric orientation was disturbed and uneven alignment occurred. Neither did iridescence caused by the diffraction pattern.

Comparative Example 2 Mw (weight average molecular weight) was about 120,000, Mw / Mn was 4.0, logarithmic viscosity was 2.0, Tg
Is 150 ° C and Ti is 240 ° C.
(Containing an optically active compound) on a rubbed polyphenylene sulfide by spin coating.
After heat treatment at 20 ° C. for 20 minutes, a light yellowish film exhibiting weak selective reflection was obtained. When the transmission spectrum of this film was measured with an ultraviolet-visible-near-infrared spectrophotometer V-570 manufactured by JASCO Corporation, the center wavelength was about 550-6.
It could not be clearly identified at 00 nm, and the selective reflection wavelength band showed a weak broad selective reflection. When observed with a microscope BX50 manufactured by Olympus Corporation, a number of alignment defects were observed in the liquid crystal layer.

Next, a ruled line diffraction grating film manufactured by Edmund Scientific Japan (900 / m)
m) and the liquid crystal surface of the film obtained above are overlapped with each other, and a laminator D manufactured by Tokyo Laminex Co., Ltd.
Using X-350, heating and pressing were performed under the conditions of 120 ° C., 3 MPa, and a roll contact time of 0.5 seconds. Next, after cooling to room temperature, the ruled line diffraction grating film was removed. On the liquid crystal surface from which the diffraction grating film was removed, more alignment defects occurred, and no iridescent color due to the diffraction pattern was exhibited.

(Comparative Example 3) Mw is 95,000, Mw / M
n = 6.0, logarithmic viscosity = 1.5, Tg = 145 ° C., Ti
Is formed on a polyphenylene sulfide rubbed with a liquid crystalline polyester (containing an R-form optically active compound) at 240 ° C. by spin coating and then heat-treated at 220 ° C. for 20 minutes. was gotten. When the transmission spectrum of this film was measured with an ultraviolet-visible-near-infrared spectrophotometer V-570 manufactured by JASCO Corporation, the center wavelength was not clearly specified at about 550 to 600 nm, and the selective reflection wavelength band was broad. It showed weak selective reflection. When observed with a microscope BX50 manufactured by Olympus Corporation, a number of alignment defects were observed in the liquid crystal layer.

Next, a ruled line diffraction grating film manufactured by Edmund Scientific Japan (900 / m)
m) and the liquid crystal surface of the film obtained above are overlapped with each other, and a laminator D manufactured by Tokyo Laminex Co., Ltd.
Using X-350, heating and pressing were performed under the conditions of 120 ° C., 3 MPa, and a roll contact time of 0.5 seconds. Next, after cooling to room temperature, the ruled line diffraction grating film was removed. On the liquid crystal surface from which the diffraction grating film was removed, more alignment defects occurred, and no iridescent color due to the diffraction pattern was exhibited.

(Comparative Example 4) Mw is 98,000, Mw / M
n is 3.0, logarithmic viscosity is 1.8, Tg is 205 ° C, Ti
Is formed on a rubbed polyphenylene sulfide by rubbing a liquid crystalline polyester (containing an R-form optically active compound) at 250 ° C. by a spin coating method and then heat-treated at 230 ° C. for 20 minutes to give a pale yellow weak selective reflection film was gotten.

When the transmission spectrum of this film was measured with an ultraviolet-visible-near-infrared spectrophotometer V-570 manufactured by JASCO Corporation, the center wavelength was not clearly specified at about 550 to 600 nm. Showed a broad weak selective reflection. When observed with a microscope BX50 manufactured by Olympus Corporation, a number of alignment defects were observed in the liquid crystal layer.

Next, a scored diffraction grating film (900 / m) manufactured by Edmund Scientific Japan
m) and the liquid crystal surface of the film obtained above are overlapped with each other, and a laminator D manufactured by Tokyo Laminex Co., Ltd.
Using X-350, heating and pressing were performed under the conditions of 120 ° C., 3 MPa, and a roll contact time of 0.5 seconds. Next, after cooling to room temperature, the ruled line diffraction grating film was removed. On the liquid crystal surface from which the diffraction grating film was removed, more alignment defects occurred, and no iridescent color due to the diffraction pattern was exhibited.

(Comparative Example 5) Mw (weight average molecular weight) of 1
040, Mw / Mn 2.1, logarithmic viscosity 0.06, T
A film was formed by spin coating on polyphenylene sulfide rubbed with a liquid crystalline polyester (containing an R-form optically active compound) having a g of 15 ° C and a Ti of 36 ° C.
After heat treatment for 5 minutes, a film exhibiting a golden specular reflection was obtained. When the transmission spectrum of the film was measured with an ultraviolet-visible-near-infrared spectrophotometer V-570 manufactured by JASCO Corporation, a cholesteric liquid crystal exhibiting selective reflection having a center wavelength of about 600 nm and a selective reflection wavelength bandwidth of about 100 nm was obtained. It was confirmed that a layer was formed.

A laminator manufactured by Tokyo Laminex Co., Ltd. is overlapped so that the diffraction surface of the ruled line diffractive element film (900 lines / mm) manufactured by Edmund Scientific Japan and the liquid crystal surface of the cholesteric alignment film obtained above face each other. 40 ° C, 0.3MP using DX-350
a, Heating and pressurization was performed under the condition of a roll contact time of 0.5 seconds. Next, after cooling to room temperature, the ruled-type diffraction element film was removed. In the obtained film, a part of the cholesteric liquid crystal phase was changed to an isotropic phase, the cholesteric alignment was disturbed, and uneven alignment occurred. Neither did iridescence caused by the diffraction pattern.

(Comparative Example 6) Mw (weight average molecular weight) of 1
030, Mw / Mn of 2.2, logarithmic viscosity of 0.046,
A film was formed by spin coating on polyphenylene sulfide rubbed with a liquid crystalline polyester (containing an R-form optically active compound) having a Tg of 20 ° C. and a Ti of 115 ° C.
After heat treatment at 00 ° C. for 5 minutes, a film having a golden specular reflection was obtained. When the transmission spectrum of the film was measured with an ultraviolet-visible-near-infrared spectrophotometer V-570 manufactured by JASCO Corporation, a cholesteric orientation showing a selective reflection having a center wavelength of about 600 nm and a selective reflection wavelength bandwidth of about 100 nm was obtained. It was confirmed that a film in which was fixed was formed.

[0098] A laminator manufactured by Tokyo Laminex Co., Ltd. is overlapped so that the diffraction surface of the ruled line diffractive element film (900 lines / mm) manufactured by Edmund Scientific Japan and the liquid crystal surface of the cholesteric alignment film obtained above face each other. Using DX-350, 50 ° C, 0.3MP
a, Heating and pressurization was performed under the condition of a roll contact time of 0.5 seconds. Next, after cooling to room temperature, the ruled-type diffraction element film was removed. In the obtained film, cracks occurred in a part of the film, and the cholesteric orientation was disturbed and uneven alignment occurred. Neither did iridescence caused by the diffraction pattern.

(Comparative Example 7) Mw is 98900, Mw / M
n = 4.0, logarithmic viscosity = 2.5, Tg = 148 ° C., Ti
Is formed on a rubbed polyphenylene sulfide by rubbing a liquid crystalline polyester (containing an R-form optically active compound) at 250 ° C. by spin coating, and then heat-treated at 220 ° C. for 20 minutes to give a pale yellow weak selective reflection film was gotten. When the transmission spectrum of this film was measured with an ultraviolet-visible-near-infrared spectrophotometer V-570 manufactured by JASCO Corporation, the center wavelength was not clearly specified at about 550 to 600 nm, and the selective reflection wavelength band was broad. It showed weak selective reflection. When observed with a microscope BX50 manufactured by Olympus Corporation, a number of alignment defects were observed in the liquid crystal layer, and uniform cholesteric alignment was not obtained. Next, a laminator DX-350 manufactured by Tokyo Laminex Co., Ltd. was overlapped so that the diffraction surface of the scored type diffraction grating film (900 lines / mm) manufactured by Edmund Scientific Japan and the liquid crystal surface of the film obtained above faced each other. Used, 12
The heating and pressurization were performed under the conditions of 0 ° C., 3 MPa, and a roll contact time of 0.5 seconds. Next, after cooling to room temperature, the ruled line diffraction grating film was removed. On the liquid crystal surface from which the diffraction grating film was removed, more alignment defects occurred, and no iridescent color due to the diffraction pattern was exhibited.

[0100]

According to the present invention, a cholesteric liquid crystal film having a unique feature that diffracted light exhibits circular polarization can be easily transferred to an object to be transferred without impairing its optical characteristics. Further, by forming from a film material having specific physical properties, the film after transfer does not suffer from disorder in orientation or cracks, and is excellent in film strength, environmental reliability, and the like, and has extremely high industrial value.

Claims (1)

[Claims] 1. A laminate comprising at least a support substrate / cholesteric liquid crystal layer / adhesive layer, wherein the cholesteric liquid crystal layer has a cholesteric liquid crystal layer having a weight average molecular weight Mw of 10 measured by GPC (polystyrene conversion).
00-100,000, molecular weight distribution (Mw / Mn; Mn is number average molecular weight) of 5 or less, logarithmic viscosity of 0.05-2.0 (concentration of 0.1 in a phenol / tetrachloroethane (weight ratio 60/40) mixed solvent). 5 g / dl (temperature 30 ° C.), a film having a glass transition temperature (Tg) of 200 ° C. or less and a polymer liquid crystal having a transition temperature (Ti) from a liquid crystal phase to an isotropic phase of 40 ° C. or more as an essential component. A transfer element composed of a material and at least partially composed of a cholesteric liquid crystal film having a region exhibiting diffractive power.