JP2013220621A - Display body, transfer display body, method of manufacturing display body, and method for transfer to transferred body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a display body, a transfer display body that is given a pattern not having color tone change partially eliminated, but partially differing in color tone by using cholesteric liquid crystal, and has high security, a method of manufacturing the display body, and a method for transfer to transferred body.SOLUTION: A display body has a layer formed from cholesteric liquid crystal applied onto a base material and having its spiral pitch fixed by an irradiation with light, and a layer formed from the cholesteric liquid crystal is heated in a pattern to change the spiral pitch of the cholesteric liquid crystal to the pattern.

Description

  The present invention relates to a display body for displaying images and characters using a cholesteric liquid crystal, and a method for manufacturing the display body, and more particularly, to a method for manufacturing a display body display having a plurality of color areas using one type of cholesteric liquid crystal. . More specifically, the present invention relates to a display body and a display body manufacturing method in which the hue is changed by shifting the spiral pitch region of the cholesteric liquid crystal partially to the short wavelength side and the long wavelength side to make the contrast clear.

  In general, liquid crystals include nematic liquid crystals (molecules arranged only in the vertical direction), smectic liquid crystals (molecules arranged in both vertical and horizontal directions), and cholesteric liquid crystals (molecules arranged in the plane direction to form a number of thin layers. The liquid crystal used in the present invention is a cholesteric liquid crystal.

  The color of the cholesteric liquid crystal is due to selective reflection due to the helical structure of cholesteric liquid crystal molecules, and the reflected light is circularly polarized light. When a desired image, image, or character is displayed using a cholesteric liquid crystal, it is necessary to control the reflected color of the cholesteric liquid crystal and fix its spiral structure in order to obtain a clear and colored image.

  Cholesteric liquid crystals are often found in cholesterol compounds. In addition, cholesteric liquid crystal states can also be obtained by adding chiral materials or introducing asymmetric carbon into nematic liquid crystals. This type of liquid crystal is sometimes referred to as chiral nematic liquid crystal, and the present invention relates to this type of cholesteric liquid crystal, but is simply referred to as cholesteric liquid crystal.

  As a conventional method for displaying characters and a screen in a desired pattern on a base material using a cholesteric liquid crystal, a cholesteric liquid crystal is placed at a position on the base material corresponding to the desired character or screen. This is a method of forming a film. This method can be achieved without much difficulty when displaying only one color.

  However, multi-color display requires preparing cholesteric liquid crystals having different colors (different spiral pitches) according to the type of color and arranging them at predetermined positions. This is possible when the desired character / image is very simple, but it is a rather difficult task when the character / image is somewhat complex. Moreover, it is necessary to prepare a large-scale apparatus and many materials.

  Since the refractive index of light periodically varies along the spiral axis, cholesteric liquid crystal selectively reflects light having a wavelength corresponding to the pitch of the spiral structure (hereinafter, spiral pitch). Therefore, if the spiral pitch that reflects the desired ultraviolet, visible or infrared light is obtained by controlling the spiral pitch in some way, the desired reflection color can be created if the spiral structure can be fixed. it can.

  There are several known techniques for changing the helical pitch. For example, a method for controlling the helical pitch according to the temperature by utilizing the high temperature dependence of the helical pitch (thermotropic liquid crystal), a solvent cholesteric liquid crystal (lyotropic cholesteric liquid crystal). Liquid crystal) by changing the helical pitch by changing the concentration of the solute, changing the pitch by generating an electric field perpendicular to the helical axis of the cholesteric liquid crystal, and adding an ultraviolet curable substance to the cholesteric liquid crystal. In addition, there is a method of changing the helical pitch by the illuminance of ultraviolet rays when fixing the helical pitch of the cholesteric liquid crystal (Patent Document 1).

  However, in Patent Document 1, when a desired image is somewhat complicated, the amount of ultraviolet light irradiated using a photomask is changed at each location of the image, thereby changing the spiral pitch and changing the color. The operation is complicated.

  Further, in order to form a region having a different spiral pitch in a desired shape using one kind of cholesteric liquid crystal, it is further described in Patent Document 1 in a state where the spiral pitch is controlled to a desired value by the above method. The helical pitch must be fixed by the polymerization curing method.

  Therefore, when two or more kinds of cholesteric liquid crystals having different helical pitches are manufactured using the method of Patent Document 1 and used for displaying two or more colors, a large-scale apparatus such as an ultraviolet pattern exposure apparatus is required, and production The nature is also low.

  As another method, there is a method in which a desired pattern is formed and polymerized using two or more kinds of cholesteric liquid crystals having different helical pitches. As a method of preparing cholesteric liquid crystals with different spiral pitches in more than the desired number of colors, a method of adding a chiral material to a nematic liquid crystal material to make a cholesteric liquid crystal can be used. Although there is a method to change, it is necessary to prepare many materials, and this method is not easy. Moreover, delicate control of the hue is difficult and often deviates from the target color.

  On the other hand, securities such as banknotes, gift certificates, and passports and authentication media have been pasted with a medium that is difficult to forge as a countermeasure against forgery. In this case, the authenticity determination is performed by visual determination (overt function) or determination using a verifier (covert function).

  As these anti-counterfeiting media, the cholesteric liquid crystal has a color change (overt function) in which the reflected color changes depending on the viewing angle, and a color change (cover function) due to the reflected color being shielded when stacked as a verifier (polarizer). ), A method for determining authenticity using a cholesteric liquid crystal by two determination methods of an overt function and a covert function has been proposed.

  Further, a method has been proposed in which a cholesteric liquid crystal exhibiting a color change is used, and the color change function is destroyed by a laser or a thermal head to form a part that exhibits a color change and a part that is destroyed and does not cause a color change. . However, there is a problem in security as in the case where a printed layer is provided in a pattern on a layer made of cholesteric liquid crystal (Patent Document 2).

JP 2000-226580 A JP 2002-71953 A

  Providing a highly secure display, display transfer body, manufacturing method thereof, and transfer method thereof by using a cholesteric liquid crystal to provide a pattern having a partially different color tone instead of partially eliminating the color change. It is to be.

As a means for solving the above-mentioned problems, the invention according to claim 1 has a layer made of cholesteric liquid crystal, which is applied on a substrate and has a layer made of cholesteric liquid crystal in which a helical pitch is fixed by light irradiation. The display body is characterized in that a region in which the spiral pitch of the cholesteric liquid crystal is changed is formed in a pattern by applying heat in a pattern.

  The invention described in claim 2 is a display body characterized in that an OVD layer is provided on a part or the entire surface of the display body described in claim 1.

  The invention described in claim 3 is characterized in that a retardation layer having a pattern arranged in at least two axial directions is provided on a part or the entire surface of the display body described in claim 1 or claim 2. It is a display body to do.

  In addition, the invention according to claim 4 absorbs a part or all of the ultraviolet, visible, and infrared regions on a part or the entire surface of the display body according to any one of claims 1 to 3. It is a display body characterized by comprising a layer having it.

  Further, the invention according to claim 5 is provided with a release protective layer on a substrate, a layer made of cholesteric liquid crystal in which a helical pitch is fixed by light irradiation, and a layer made of cholesteric liquid crystal. A transfer display body comprising an adhesive layer, and a region in which the spiral pitch of the cholesteric liquid crystal is changed to a pattern by forming heat in a pattern.

  According to a sixth aspect of the present invention, there is provided a transfer display body comprising an OVD layer on a part or the entire surface of the transfer display body according to the fifth aspect.

  The invention described in claim 7 is characterized in that a retardation layer having a pattern arranged in at least two axial directions is provided on a part or the entire surface of the transfer display body described in claim 5 or 6. And a transfer display body.

  Further, the invention according to claim 8 is absorbed in part or all of the ultraviolet, visible, and infrared regions on a part or the entire surface of the transfer display according to any one of claims 5 to 7. It is the transfer display body characterized by comprising the layer which has.

The invention according to claim 9 is a method for manufacturing a display using cholesteric liquid crystal,
Applying the cholesteric liquid crystal on a substrate and providing a cholesteric liquid crystal layer;
Irradiating the cholesteric liquid crystal layer with light to fix the helical pitch; and
Applying a heat to a partial region of the cholesteric liquid crystal layer with a heated metal plate, a laser or a thermal head to form a region in which the helical pitch of the cholesteric liquid crystal is changed,
A display body manufacturing method characterized by comprising the display body.

The invention according to claim 10 is a method for producing a transfer display using cholesteric liquid crystal,
Providing a release protective layer on the substrate;
Applying the cholesteric liquid crystal on the release protective layer and providing a cholesteric liquid crystal layer;
Irradiating the cholesteric liquid crystal layer with light to fix the helical pitch; and
A step of providing an adhesive layer on the layer made of the cholesteric liquid crystal;
Applying a heat to a partial region of the cholesteric liquid crystal layer with a heated metal plate, a laser or a thermal head to form a region in which the helical pitch of the cholesteric liquid crystal is changed,
This is a method for producing a transfer display body characterized in that it is provided.

The invention according to claim 11 is a method for transferring a transfer display body using a cholesteric liquid crystal to a transfer target,
Providing a release protective layer on the substrate;
Applying the cholesteric liquid crystal on the release protective layer and providing a cholesteric liquid crystal layer;
Irradiating the cholesteric liquid crystal layer with light to fix the helical pitch; and
Furthermore, it has a step of providing an adhesive layer on the layer made of the cholesteric liquid crystal,
Heat is applied to a partial area of the cholesteric liquid crystal layer from the substrate surface with a heated metal plate, a laser or a thermal head to change the helical pitch of the cholesteric liquid crystal, and to the transferred material, a peeling protective layer, a cholesteric liquid crystal layer And transferring the adhesive layer to the transfer target.

  According to the present invention, without using a large-scale device or a plurality of cholesteric liquid crystals, a single cholesteric liquid crystal can be used to easily change a plurality of cholesteric liquid crystals by changing the spiral pitch of the cholesteric liquid crystal for a desired region. It is possible to provide a display body and a method for manufacturing the display body, which can obtain the same effect as the case of using the display body.

FIG. 3 is a conceptual cross-sectional view of a display body in which the spiral pitch of cholesteric liquid crystal is changed into a pattern according to the present invention. It is the cross-sectional conceptual diagram which showed the state which affixed the display body of this invention on the to-be-transferred base material. It is the conceptual diagram which showed the manufacturing process of the display body which changed the helical pitch of the cholesteric liquid crystal of this invention into the pattern form. It is the conceptual diagram which showed the transfer mechanism of the transfer display body which changed the helical pitch of the cholesteric liquid crystal of the present invention into the pattern form. It is the conceptual diagram which showed the plane of the display body which changed the spiral pitch of the cholesteric liquid crystal of this invention in the pattern form.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. FIG. 1 shows a cross section of a display body in which the spiral pitch of the cholesteric liquid crystal of the present invention is changed into a pattern. After the cholesteric liquid crystal 1 on the substrate 3 is provided and fixed, the first heating portion 21 and The 2nd heating part 22 is crimped | bonded and the 1st area | region 11 and the 2nd area | region 12 from which a helical pitch differs are formed.

  The display body shown in FIG. 2 shows a state in which the cholesteric liquid crystal 1 and the adhesive layer 4 are sequentially provided on the base material 3 and bonded to the transfer base material 5. By the heating process, the cholesteric liquid crystal layer 1 includes regions having different spiral pitches of the first region 11 and the second region 12. Heating is performed by bringing the first heating portion 21 and the second heating portion 22 having different temperatures into contact with each other, and regions having different helical pitches are obtained.

  FIG. 3 shows a manufacturing process of the display body in which the spiral pitch of the cholesteric liquid crystal is changed into a pattern. The uncured cholesteric liquid crystal layer 8 is irradiated with light from the light source 10 to generate a semi-cured lesteric liquid crystal layer 9. And The uncured cholesteric liquid crystal before light irradiation has fluidity because it is not cured in the liquid crystal state. By bringing the first heating portion 21 and the second heating portion 22 having different temperatures into contact with the semi-cured lesteric liquid crystal layer 9, the helical pitch of the cholesteric liquid crystal is changed.

  FIG. 4 shows a transfer mechanism of the transfer display body in which the spiral pitch of the cholesteric liquid crystal is changed into a pattern, and a peeling protective layer 6 is provided on the base material 3, and the cholesteric liquid crystal is laminated thereon. After being semi-cured by light irradiation, the heat-melting type adhesive layer 4 is provided, and the first heating portion 21 and the second heating portion 22 are brought into contact with each other, thereby simultaneously adjusting the helical pitch of the cholesteric liquid crystal. .

  FIG. 5 is a plan view of FIG. 1 and FIG. 2 as viewed from above, and includes a first region 11 and a second region 12 having different color tones. By changing the heating temperature, FIG. It is also possible to provide the region 13.

  The cholesteric liquid crystal display having regions with different spiral pitches according to the present invention is, for example, a region in which the color of the first region 11 changes from red to green when the display is viewed by gradually tilting from the front. The second region 12 is a display body provided with a region that changes from green to blue.

  That is, a display body including a region in which the color shifts from red having a reflection wavelength of 610 to 750 nm to a green color having 500 to 560 nm and a region in which the color shifts from green having a reflection wavelength of 500 to 560 nm to blue having a wavelength of 435 to 480 nm. It is.

  As described above, the liquid crystal used in the present invention is a cholesteric liquid crystal. A cholesteric liquid crystal has a helical periodic structure in a direction perpendicular to the molecular axis, and the pitch of the helical structure establishes a correlation with light. As a result, the cholesteric liquid crystal selectively reflects light having a wavelength corresponding to the helical pitch. Therefore, if the spiral pitch that reflects the desired light is obtained by controlling the spiral pitch by some method, the desired reflection color can be created if the spiral structure can be fixed.

  As the cholesteric liquid crystal 1 used in the present invention, a cholesteric liquid crystal-forming compound having a cholesteric structure or having a cholesteric structure under a temperature condition or the like added with an energy ray curable compound is used.

  Examples of the cholesteric liquid crystal forming compound include conventionally known hydroxyalkyl cellulose acyl derivatives, cholesteric liquid crystal forming polypeptides, cholesteric liquid crystal forming aromatic polyesters, polycarbonates, aromatic polyester imides, and aromatic polyamides. Main chain type polymer liquid crystal forming compounds such as poly (meth) acrylate type, polymalonate type, polysiloxane type and the like are used.

  Examples of the hydroxyalkyl cellulose used for the acyl derivative of hydroxyalkyl cellulose include hydroxypropyl cellulose, hydroxybutylated hydroxypropyl cellulose, and the like.

  It is necessary to introduce a flexible molecular chain to the side chain of the rigid cellulose molecule main chain, and various acyl derivatives are used to control the length, flexibility, rigidity, etc. of the side chain. .

For example, esters of aliphatic, alicyclic and aromatic carboxylic acids having about 1 to 30 carbon atoms are preferred. For example, acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, isovaleric acid, 2-methylbutyric acid, trimethylacetic acid, caproic acid, heptanoic acid, caprylic acid, nonanoic acid, capric acid, lauric acid, palmitic acid , Esters of saturated carboxylic acids such as stearic acid and isostearic acid, esters of alicyclic carboxylic acids such as cyclohexanecarboxylic acid, cyclohexylacetic acid, cyclohexanepropionic acid and cyclohexanebutyric acid, benzoic acid, phenylacetic acid, 3-phenylpropionic acid Preference is given to esters of aromatic carboxylic acids such as 5-phenylvaleric acid, 4-phenylbutyric acid and esters of unsaturated carboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, itaconic acid.

  In addition, the properties and behavior differ depending on the degree of esterification. Therefore, fully esterified products and partially esterified products are used as the design of the compounds. In addition, unsaturated carboxylic acid esters can cause a curing (polymerization) reaction with an energy ray-curable compound used in combination with a liquid crystal compound. Therefore, it is also an effective method to use a part of the saturated carboxylic acid, for example, 0.1 to 20%, for the purpose of crosslinking, with the unsaturated carboxylic acid.

  Preferred are hydroxypropylcellulose acetate, hydroxypropylcellulose propionate, hydroxybutylated hydroxypropylcellulose acetate, hydroxybutylated hydroxypropylcellulose propionate, hydroxybutylcellulose acetate, hydroxybutyl Propionic acid ester of cellulose, etc. Hydroxypropyl cellulose acrylic ester, Hydroxypropyl cellulose methacrylic ester, Hydroxybutylated hydroxypropyl cellulose acrylic ester, Hydroxybutylated hydroxypropyl cellulose methacrylate, Hydroxybutyl cellulose acrylic Acid ester, hydroxybutyl cellulose Fully and partially esterified products such as oxalic acid ester, hydroxypropylcellulose acetate-methacrylic acid ester, hydroxypropylcellulose propionate-methacrylic acid ester, hydroxybutylated hydroxypropylcellulose propionate-methacrylic acid ester And propionic acid ester-methacrylic acid ester of hydroxybutyl cellulose.

  As the cholesteric liquid crystal forming compound, conventionally known low molecular weight and medium molecular weight cholesteric liquid crystal forming compounds may be used alone or in combination with the above high molecular weight cholesteric liquid crystal forming compound.

  The energy ray curable compound added to the liquid crystal forming compound is not particularly limited, and conventionally known energy ray curable compounds are used, and in particular, two or more energy ray curable compounds in the molecule. It is preferable to contain a monomer having a group, an oligomer, a polymer, an oligomer and a polymer.

  Examples of the radical photopolymerizable monomer include known trimethylolpropane tri (meth) acrylate, 1,6-hexanediol di (meth) acrylate, pentaerythritol tetra (meth) acrylate, and pentaerythritol tri (meta). ) Acrylates, polyfunctional monomers such as dipentaerythritol hexa (meth) acrylate, polyurethane poly (meth) acrylate, polyether poly (meth) acrylate, epoxy resin poly (meth) acrylate, acrylic polyol poly (meth) acrylate Polyfunctional oligomers such as are preferred.

  Monofunctional monomers include alkyl (C1 to C18) (meth) acrylate, benzyl (meth) acrylate, cyclohexyl (meth) acrylate, alkylene (C2 to C4) glycol (meth) acrylate, alkoxy (C1 to C10). ) Alkyl (C2-C4) (meth) acrylate, polyalkylene (C2-C4) glycol (meth) acrylate, alkoxy (C1-C10) polyalkylene (C2-C4) glycol (meth) acrylate, and the like. As the cationic photopolymerizable monomer, conventionally known aromatic epoxy compounds, alicyclic epoxy compounds, and glycidyl ester compounds can be exemplified.

  In addition, as the polymerization initiator for causing energy beam curing used in the present invention, a known polymerization initiator having appropriate characteristics can be used as necessary depending on the energy beam to be irradiated. For example, conventionally known photopolymerization initiators can be used.

  Known radical photopolymerization initiators such as α-hydroxyacetophenone and α-aminoacetophenone acetophenones, benzoin ethers, benzyl ketals, α-dicarbonyls, α-acyl oxime esters, etc. are used. Specifically, α-aminoacetophenone, acetophenone diethyl ketal, benzyldimethyl ketal, α-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methylphenylpropanone, benzophenone, Michler's ketone, isopropylthioxanthone, benzophenone and N-methyldiethanolamine Can be used. As the cationic photopolymerization initiator, conventionally known ones may be used alone or in combination with a sensitizer or a peroxide.

  For example, allyl iodonium salt-α-hydroxyacetophenone, triallylsulfonium salt, metallocene compound-peroxide combination, metallocene compound-thioxanthone combination, metallocene compound-ant helical combination.

  In the preparation of the composition of the cholesteric liquid crystal forming compound and the energy ray polymerizable compound, the blending amount is not particularly limited. For example, the cholesteric liquid crystal forming compound is 40 to 98 parts by weight, and the energy ray polymerizable compound is 60 to 2 parts by weight. , 0 to 10 parts by weight of the polymerization initiator, preferably 55 to 95 parts by weight of the cholesteric liquid crystal forming compound, 45 to 5 parts by weight of the energy ray polymerizable compound, and 0 to 5 parts by weight of the polymerization initiator. Is the ratio. If necessary, both good solvents can be used as dissolution aids. Further, various conventionally known additives can be included as required.

  Furthermore, the energy ray curable compound is polymerized and fixed by irradiation with energy rays. The energy ray curable compound and the photopolymerization initiator added to the cholesteric liquid crystal forming compound to be immobilized are not particularly limited, and known materials can be used. Moreover, there is no limitation in particular also about the compounding ratio.

  In the bond polymerization reaction on the surface of the cholesteric liquid crystal layer, it is preferable to leave an unreacted double bond. As the ratio of unreacted double bonds, the residual double bond ratio of C = C can be used.

The residual double bond ratio is (spectrum intensity of absorption based on C = C bond (wave number: 810 cm ⁻¹ ) / spectrum intensity of absorption based on aromatic ring in liquid crystal molecule (wave number: around 1500 cm ⁻¹ )). Defined by

  When polymerizing in a nitrogen atmosphere, if the oxygen concentration is too low, the reaction will be excessive, so the oxygen concentration in the nitrogen atmosphere is preferably 0.5% or more. The residual double bond ratio after curing in the liquid crystal molecules is preferably 50% or more and 95% or less. Desirably, it is 70 to 90%. In the state where the residual double bond ratio is low and curing has progressed too much, it becomes difficult to change the helical pitch of the cholesteric liquid crystal in the heating step as described later, while in the extremely uncured state where the residual double bond ratio is high and This is because surface inconvenience or the like causes inconvenience in handling, and the structure of the cholesteric liquid crystal may be destroyed during the heating process.

  As conditions for polymerizing liquid crystal molecules, ultraviolet rays may be irradiated in the air, or ultraviolet rays may be irradiated in a nitrogen atmosphere. Depending on the liquid crystal material, the residual double bond ratio may be adjusted by the amount of ultraviolet irradiation.

  As described above, the unreacted double bond remains, so that the cholesteric liquid crystal layer is not sufficiently cured. A cholesteric liquid crystal layer that is insufficiently cured has reduced heat resistance and the like, and when heated, the molecular structure of the cholesteric liquid crystal changes, and as a result, the cholesteric liquid crystal layer is fixed in a state where the helical pitch is changed.

  As a heating step, heating may be performed while applying pressure with an embossed mold having unevenness that has been heated in advance, or the heating portion may be heated to different temperatures such as the heating portions shown in FIG. 1, FIG. 3, and FIG. 4. A metal plate or the like having a region may be pressed. Moreover, you may heat partially with a laser or a thermal head layer.

  In addition, since the heating process can provide a difference in the change in the helical pitch depending on the difference in temperature, pressure, and contact time, adjustment is performed so that the desired color tone is obtained depending on the temperature, pressure, and contact time in the heating process. Good. Further, when heating the cholesteric liquid crystal, the cholesteric liquid crystal may be heated by bringing a heated mold or plate into contact with the cholesteric liquid crystal, or may be performed over the substrate.

  The substrate that can be used in the present invention may be opaque or transparent. For example, a plastic film produced by stretching can be used. There are uniaxially stretched and biaxially stretched films depending on how to stretch. These include cellophane, polycarbonate (PC), polyethylene (PE), polypropylene (PP), polyolefin (PO), ethylene vinyl alcohol (EVOH), polyvinyl alcohol (PVA), polyvinyl chloride, polyethylene naphthalate (PEN). Polyethylene terephthalate (PET), nylon, acrylic resin, triacetyl cellulose (TAC) film, and the like. Above all, a base material containing a dye that absorbs light can more effectively display cholesteric liquid crystals. Moreover, when a transparent base material is selected, an absorbent layer may be provided on the base material.

  The material used for the adhesive layer 4 can be formed using a general adhesive material as long as it does not affect the contact layer. For example, vinyl chloride-vinyl acetate copolymer, polyester polyamide, acrylic, butyl rubber, natural rubber, silicone, polyisobutyl adhesive alone or alkyl methacrylate, vinyl ester, acrylonitrile, styrene, vinyl monomer Necessary additives such as coagulation components such as unsaturated carboxylic acids, hydroxy group-containing monomers, acryl nitriles, and other reforming components, polymerization initiators, plasticizers, curing agents, curing accelerators, and antioxidants What was added according to it can be used. For the formation of the adhesive layer, a known gravure printing method, offset printing method, screen printing method or other printing method or bar coating method, gravure method, roll coating method or the like can be used.

  The OVD (Optical Variable Device) layer in the present invention is an image that uses light interference, and is a display body that causes a color shift in which the color changes depending on the representation of the stereoscopic image and the viewing angle. Is a possible medium. Among them, examples of the OVD such as a hologram and a diffraction grating include a relief type that records light interference fringes on a plane as a fine uneven pattern and a volume type that records interference fringes in a volume direction.

Also, although the method is different from that of holograms and diffraction gratings, there are multilayer film systems in which thin films of ceramics and metal materials with different optical properties are laminated, and materials that cause color changes (color shift) depending on the viewing angle due to liquid crystal materials, etc. This is an example. These OVDs can be said to be effective means for preventing forgery because they give a unique impression such as stereoscopic images and color shifts and require advanced manufacturing techniques.

  Among these OVDs, in consideration of mass productivity and cost, a relief hologram (or a relief diffraction grating) or a multilayer thin film type is preferable, and these OVDs are generally widely used.

  First, a relief hologram will be described. This relief type hologram or relief type diffraction grating is mass-produced using a relief type press plate having a fine uneven pattern forming a hologram or a diffraction grating, respectively. That is, this press plate heats and pressurizes the OVD forming layer to replicate a fine uneven pattern.

The OVD forming layer is for increasing the diffraction efficiency, and is made of a material having a refractive index different from that of the polymer material constituting the relief surface. As a material to be used, high refractive index materials such as TiO ₂ , Si ₂ O ₃ , SiO, Fe ₂ O ₃ , and ZnS having different refractive indexes, Al, Sn, Cr, Ni, Cu, Au, and the like having a higher reflection effect are used. The metal material can be raised. These materials are used alone or laminated. As described above, these materials are formed by a known thin film forming technique such as vacuum vapor deposition or sputtering.

  Furthermore, a multilayer thin film method will be described. When the multilayer thin film method is used, as described above, the OVD forming layer is formed of a multilayer thin film layer having different optical aptitudes, and is formed by laminating as a metal thin film, a ceramic thin film, or a composite thin film including them together. For example, when thin films having different refractive indexes are stacked, a high refractive index thin film and a low refractive index thin film may be combined, or a specific combination may be stacked alternately. By combining them, a desired multilayer thin film can be obtained.

This multilayer thin film layer is made of a material such as ceramics or metal, and is formed by laminating approximately two or more high refractive index materials and a low refractive index material having a refractive index of about 1.5 with a predetermined film thickness. Below, the example of the material used is described. As ceramics, Sb ₂ O ₃ (3.0 = refractive index n: the same applies hereinafter), Fe ₂ O ₃ (2.7), TiO ₂ (2.6), CdS (2.6), CeO ₂ (2 .3), ZnS (2.3), PbCl ₂ (2.3), CdO (2.2), Sb ₂ O ₃ (2.0), WO ₃ (2.0), SiO (2.0) , Si ₂ O ₃ (2.5), In ₂ O ₃ (2.0), PbO (2.6), Ta ₂ O ₃ (2.4), ZnO (2.1), ZrO ₂ (2. 0), MgO (1.6), SiO ₂ (1.5), MgF ₂ (1.4), CeF ₃ (1.6), CaF ₂ (1.3 to 1.4), AlF ₃ (1 .6), Al ₂ O ₃ (1.6), GaO (1.7) and the like.

  And as a metal simple substance or an alloy thin film, Al, Fe, Mg, Zn, Au, Ag, Cr, Ni, Cu, Si etc. can be mention | raise | lifted, for example. Examples of the low refractive index organic polymer include polyethylene (1.51), polypropylene (1.49), polytetrafluoroethylene (1.35), polymethyl methacrylate (1.49), polystyrene (1 .60) and the like.

  By selecting at least one kind from these high refractive index materials or 30% to 60% transparent metal thin film, selecting at least one kind from low refractive index materials, and alternately laminating them at a predetermined thickness, It shows absorption or reflection for visible light.

Each of the above materials is appropriately selected based on optical properties such as refractive index, reflectance, and transmittance, weather resistance, interlayer adhesion, and the like, and is laminated as a thin film to form a multilayer thin film layer. A known method can be used as the formation method, and the film thickness, film formation speed, number of layers, or optical film thickness (= n · d, n: refractive index, d: film thickness) can be controlled. The vacuum evaporation method and the sputtering method are used.

  As the retardation layer in the present invention, liquid crystal molecules can be used. As a method of aligning liquid crystal molecules biaxially, it can be formed by applying a liquid crystal material on an alignment film in which the alignment treatment direction is partially changed. For the alignment treatment of the alignment film for aligning the liquid crystal material, for example, a photo alignment method or a rubbing alignment method can be used.

  The photo-alignment method is a method in which the alignment film is irradiated with light having anisotropy such as polarized light or non-polarized light from an oblique direction to induce rearrangement of molecules in the alignment film or anisotropic chemical reaction, This utilizes the fact that liquid crystal molecules are aligned by giving anisotropy to the alignment film. Examples of the photo-alignment mechanism include photo-anisotropy of azobenzene derivatives, photo-dimerization and crosslinking of derivatives such as cinnamic acid ester, coumarin, chalcone and benzophenone, and photo-decomposition of polyimide and the like.

  Specifically, it is performed by pattern exposure with polarized light in an appropriate wavelength band or non-polarized light from an oblique direction. Also, when aligning in the biaxial direction, such as a polarized latent image portion and a polarized background portion, pattern exposure is performed by covering the portion whose orientation direction is to be changed with a photomask, and further, the unexposed portion covered with the photomask. In order to process, exposure may be performed while changing the direction. Alternatively, once the entire surface is once exposed to pattern, it may be partially covered with a photomask and changed in direction to be exposed again.

  The rubbing alignment method is a method of rubbing an alignment film created by applying a polymer solution on a substrate with a cloth. The property of the alignment film surface changes in the rubbing direction and liquid crystal molecules are aligned in this direction. It is a thing. For the alignment film, polyimide, PVA, or the like is used.

  When aligning the optical axis in the biaxial direction, cover the part whose orientation direction is to be changed with a mask, rub it with a cloth, remove the mask, then cover the rubbed part with the mask and turn the direction again. After changing and rubbing with a cloth, the mask is removed. Alternatively, after the entire surface is rubbed with a cloth, the mask may be partially covered with a mask, the direction is changed, and the mask is removed after being rubbed with a cloth.

  As a method for forming these alignment films, known methods such as a gravure coating method and a micro gravure coating method can be used.

  Liquid crystal materials include photocurable liquid crystal monomers with acrylates at both ends of the mesogenic group, polymer liquid crystals cured with EB or UV, polymer liquid crystals with mesogenic groups in the polymer main chain, and the molecular main chain itself. A liquid crystalline polymer can be used. The orientation of these liquid crystals can be promoted by heat treatment at a temperature slightly below the NI point at which phase transition occurs after coating.

DESCRIPTION OF SYMBOLS 1 ... Cholesteric liquid crystal layer 2 ... Heating component 3 ... Base material 4 ... Adhesive layer 5 ... Transfer target substrate 6 ... Peeling protection layer 7 ... Transfer display body 8 ... Uncured cholesteric liquid crystal layer 9 ... Semi-cured cholesteric liquid crystal layer 10 ... Light source 11 ... First region 12 ... Second region 13 ... Third region 21 ... First heating portion 22 ... Second heating part 23 ... Non-heating part

Claims (11)

  A layer made of cholesteric liquid crystal coated on a substrate and having a helical pitch fixed by light irradiation was applied, and the spiral pitch of the cholesteric liquid crystal was changed by applying heat to the layer made of cholesteric liquid crystal in a pattern. A display body characterized in that a region is formed in a pattern.   A display body comprising an OVD layer on a part or the entire surface of the display body according to claim 1.   A display body comprising a retardation layer having a pattern arranged in at least two axial directions on a part or the entire surface of the display body according to claim 1.   A display comprising a layer having absorption in a part or all of the ultraviolet, visible, and infrared regions on a part or the entire surface of the display body according to any one of claims 1 to 3. body.   A peeling protective layer on the substrate, a layer made of cholesteric liquid crystal with a helical pitch fixed by light irradiation on the substrate, and an adhesive layer on the layer made of cholesteric liquid crystal, and heat is applied in a pattern. A transfer display body, wherein a region in which the spiral pitch of the cholesteric liquid crystal is changed in a pattern is formed.   A transfer display body comprising an OVD layer on a part or the entire surface of the transfer display body according to claim 5.   A transfer display body comprising a retardation layer having a pattern arranged in at least two axial directions on a part or the entire surface of the transfer display body according to claim 5.   A layer having absorption in part or all of the ultraviolet, visible, and infrared regions is provided on a part or the entire surface of the transfer display according to any one of claims 5 to 7. Transcription display. A method for producing a display using cholesteric liquid crystal,
Applying the cholesteric liquid crystal on a substrate and providing a cholesteric liquid crystal layer;
Irradiating the cholesteric liquid crystal layer with light to fix the helical pitch; and
Applying a heat to a partial region of the cholesteric liquid crystal layer with a heated metal plate, a laser or a thermal head to form a region in which the helical pitch of the cholesteric liquid crystal is changed,
A method for manufacturing a display body, comprising: A method for producing a transfer display using cholesteric liquid crystal,
Providing a release protective layer on the substrate;
Applying the cholesteric liquid crystal on the release protective layer and providing a cholesteric liquid crystal layer;
Irradiating the cholesteric liquid crystal layer with light to fix the helical pitch; and
A step of providing an adhesive layer on the layer made of the cholesteric liquid crystal;
Applying a heat to a partial region of the cholesteric liquid crystal layer with a heated metal plate, a laser or a thermal head to form a region in which the helical pitch of the cholesteric liquid crystal is changed,
A method for producing a transfer display, comprising: A method for transferring a transfer display using cholesteric liquid crystal to a transfer target,
Providing a release protective layer on the substrate;
Applying the cholesteric liquid crystal on the release protective layer and providing a cholesteric liquid crystal layer;
Irradiating the cholesteric liquid crystal layer with light to fix the helical pitch; and
Furthermore, it has a step of providing an adhesive layer on the layer made of the cholesteric liquid crystal,
Heat is applied to a partial area of the cholesteric liquid crystal layer from the substrate surface with a heated metal plate, a laser or a thermal head to change the helical pitch of the cholesteric liquid crystal, and to the transferred material, a peeling protective layer, a cholesteric liquid crystal layer A method for transferring to an object to be transferred, wherein the adhesive layer is transferred.