JPWO2017110225A1 - Optical film - Google Patents

Abstract

The optical film 100 has a protective film 50 and a liquid crystal layer 30. The liquid crystal material of the partial region 30a of the liquid crystal layer 30 and the liquid crystal material of the other region 30b are the same, and the liquid crystal material of the partial region 30a and the liquid crystal material 30b of the other region have different alignment states. A concavo-convex pattern 60 exhibiting diffractive power may be provided on the lower surface of the liquid crystal layer 30. Provided is an optical film excellent in design that can be easily manufactured without damaging the liquid crystal layer.

Description

  The present invention relates to an optical film including a cholesteric liquid crystal layer.

  An optical film on which a hologram is formed is known as a film imparted with design properties. Such an optical film is manufactured, for example, by a method of transferring a hologram (diffraction grating or the like) by pressing a heated hologram master on a cholesteric liquid crystal film formed on an alignment film (see, for example, Patent Document 1).

  A sheet with a forgery prevention function is also known as an optical film in which a plurality of regions having different selective reflection wavelengths are provided in a cholesteric liquid crystal layer. Such a sheet is manufactured, for example, by a method of irradiating the cholesteric liquid crystal layer with ultraviolet rays in a pattern form through a photomask provided with slits in a pattern form.

JP 2000-347016 A

  However, in the method described in Patent Document 1, it is necessary to press the heated hologram original plate against the liquid crystal film, and pressure is applied to the substrate and the liquid crystal layer itself under heating, so that deformation of the substrate and damage to the liquid crystal layer are caused. There is a problem that it occurs or a deviation occurs from the designed selective reflection wavelength.

  This invention is made | formed in view of the subject which the said prior art has, and provides the optical film which can manufacture easily the optical film which provided the designability, without damaging a liquid crystal layer. Objective. Another object of the present invention is to provide an optical film excellent in design.

  In order to achieve the above object, the present invention provides an optical film having a liquid crystal layer, wherein a liquid crystal material in a partial region of the liquid crystal layer is the same as a liquid crystal material in another region, and the partial region There is provided an optical film characterized in that the liquid crystal material of the above and the liquid crystal material of the other region have different alignment states.

According to the method for producing an optical film invented by the inventors of the present invention, the liquid crystal layer formed on the alignment film is erased or weakened by a surface treatment so that the alignment layer is partially aligned. The liquid crystal material is not aligned in the region on the alignment film where the light is erased or weakened, and a region having a different alignment state from other regions is formed. As a result, an optical film in which a pattern is formed by regions having different alignment states of the liquid crystal layer and design properties are imparted is obtained. And since the region where the alignment state of the liquid crystal layer is different can be formed by surface treatment of the alignment film, an optical film on which a desired pattern is formed is easily manufactured without damaging the liquid crystal layer. be able to. In particular, when the alignment film is subjected to surface treatment, no external force is applied after the liquid crystal layer is formed, so that deformation of the substrate, damage to the liquid crystal layer, and the like do not occur. Further, since reheating is not performed after the liquid crystal layer is formed, the selective reflection wavelength is not shifted. As the surface treatment method of the alignment film, methods such as solvent application to a partial region of the alignment film, direct drawing with CO ₂ laser light, excimer UV irradiation using a mask, and electron beam (EB) drawing are used. Is mentioned. Moreover, the method of providing orientation ability by rubbing using the mask mentioned later can also be used.

  In the optical film of the present invention, the liquid crystal material in a partial region of the liquid crystal layer may not be regularly aligned. In the optical film of the present invention, the liquid crystal layer may be a continuous film formed by applying a liquid crystal material on an alignment film. In the optical film of the present invention, the liquid crystal material may be a cholesteric liquid crystal. The optical film of the present invention may further include a protective film.

  The optical film of the present invention may include a separator that can be peeled off via a paste layer on the surface of the liquid crystal layer. Furthermore, another separator that can be peeled off via an adhesive layer may be provided on the surface of the liquid crystal layer opposite to the adhesive layer.

  The optical film of the present invention may further comprise a microlens array or a lenticular lens array.

  The optical film of the present invention may have a region exhibiting diffractive power in the liquid crystal layer, or may further include a layer exhibiting diffractive power. The optical film of the present invention may have a printing layer under the liquid crystal layer.

  According to the present invention, an optical film having a simple structure and excellent design can be obtained.

1A to 1F are explanatory views for explaining an embodiment of a method for producing an optical film of the present invention. It is a schematic sectional drawing of the optical film of 2nd Embodiment of this invention. It is a schematic sectional drawing of the optical film of 3rd Embodiment of this invention. It is a schematic sectional drawing of the optical film of 4th Embodiment of this invention. It is a schematic sectional drawing of the optical film of 5th Embodiment of this invention. It is a schematic sectional drawing of the optical film of 6th Embodiment of this invention. It is a schematic sectional drawing of the optical film of 7th Embodiment of this invention. It is a schematic sectional drawing of the optical film of 8th Embodiment of this invention. It is a schematic sectional drawing of the optical film of 9th Embodiment of this invention. It is a schematic sectional drawing of the optical film of 10th Embodiment of this invention. It is explanatory drawing which shows a mode that it is observed using a viewer whether an optical film is authentic. It is a schematic sectional drawing of the optical film of 11th Embodiment of this invention which provided the micro lens array on the liquid crystal layer. It is a schematic sectional drawing of the optical film of 12th Embodiment of this invention which provided the lenticular lens array on the liquid crystal layer. FIGS. 14A to 14E are diagrams showing a process of transferring the liquid crystal layer of the optical film to an article (transfer object) in the fourteenth embodiment of the present invention. FIGS. 15A to 15H and 15H are diagrams illustrating a process of transferring the liquid crystal layer of the optical film to an article (transfer object) in the fifteenth embodiment of the present invention.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and redundant description is omitted. Further, the dimensional ratios in the drawings are not limited to the illustrated ratios.

1st Embodiment 1st Embodiment of the optical film of this invention is described using Fig.1 (a)-(f). Drawing 1 (a)-(f) is an explanatory view for explaining a manufacturing method of an optical film concerning this embodiment.

  First, as shown in FIG. 1A, an alignment film 20 is formed on the substrate 10. As shown in FIG. 1B, the surface of the alignment film 20 is rubbed using a rubbing roll 70 to impart alignment ability to the alignment film 20.

  Next, a surface treatment for eliminating or weakening the alignment ability of a part of the region 22 of the alignment film 20 is performed. For example, as shown in FIG. 1C, a solvent is attached to a stamp (solvent application unit) 80, and this is pressed against a part of the region (solvent application unit) 22 on the alignment film 20 provided with alignment ability. Thus, a solvent is applied to the region 22 and the orientation ability of the region 22 is lost (solvent application step).

  As shown in FIG. 1 (d), a liquid crystal composition containing a liquid crystal material is applied on the alignment film 20, and the liquid crystal material is aligned by heating, and then the alignment is fixed to form the liquid crystal layer 30 (liquid crystal Layer forming step). At this time, since the alignment ability of some of the regions 22 of the alignment film 20 has disappeared, the liquid crystal material is not regularly aligned in the region of the liquid crystal layer 30 located on the region 22. Since the alignment state of the liquid crystal material is different, the pattern 32 is formed in the liquid crystal layer 30. The symbol 32 corresponds to the symbol formed on the stamp 80.

  As shown in FIG. 1 (e), a translucent protective film 50 is stuck on the liquid crystal layer 30 via an adhesive 40. As shown in FIG. 1 (f), the alignment film 20 and the substrate 10 are peeled off from the liquid crystal layer 30 to obtain an optical film 100 composed of the liquid crystal layer 30 / the adhesive 40 / the translucent protective film 50.

  According to the manufacturing method, the pattern 32 can be formed on the liquid crystal layer 30 very simply by simply applying a solvent to the alignment film 20 by a solvent application means such as the stamp 80. Further, after the liquid crystal layer 30 is formed, it is not necessary to apply an extra external force for pattern formation such as pressing a heated hologram original plate, so that the liquid crystal layer 30 is not damaged. Therefore, the optical film which provided the designability with the said manufacturing method can be manufactured easily, without giving a damage to a liquid-crystal layer. Hereinafter, each material and each process used for the said manufacturing method are demonstrated in detail.

  The substrate 10 functions as a support for the alignment film 20 and the liquid crystal layer 30. After the translucent protective film 50 is formed on the liquid crystal layer 30, the substrate 10 is peeled off together with the alignment film 20. Examples of the supporting substrate having such a function include polyimide, polyamideimide, polyamide, polyetherimide, polyetheretherketone, polyetherketone, polyketone sulfide, polyethersulfone, polysulfone, polyphenylene sulfide, polyphenylene oxide, and polyethylene terephthalate. , Polybutylene terephthalate, polyethylene naphthalate, polyacetal, polycarbonate, polyarylate, acrylic resin, epoxy resin, phenol resin, polyvinyl alcohol, cellulosic plastics, polyethylene, polypropylene, poly (4-methyl-1-pentene), norbornene Plastic films and sheets formed from chain-type or alicyclic polyolefins, etc. And the like.

  Further, as the substrate 10, a plastic film or sheet whose surface has been subjected to a surface treatment such as a silicon treatment, or an acrylic resin, a methacrylic resin, an epoxy resin, or a paraffin wax coated thereon can be used. . Furthermore, as the substrate 10, a plastic film or sheet that has been subjected to physical deformation treatment such as embossing, hydrophilization treatment, hydrophobization treatment, or the like can be used.

  The thickness of the substrate 10 is usually 8 to 200 μm, preferably 15 to 150 μm, and more preferably 20 to 100 μm. When the thickness is thinner than 8 μm, the handling property at the time of producing the optical film tends to be lowered. When the thickness is greater than 200 μm, the workability when the substrate 10 is peeled from the liquid crystal layer 30 together with the alignment film 20 tends to be reduced.

  The alignment film 20 is a layer having a function of aligning the liquid crystal material. The substrate 10 may also serve as the alignment film 20. Examples of the material constituting the alignment film 20 include polyvinyl alcohol, polyimide, polymethyl methacrylate, polystyrene, polycarbonate, and polyethylene terephthalate.

  The alignment film 20 can be formed, for example, by applying a solution obtained by dissolving the constituent materials in a solvent on the substrate 10 and drying the film to form a film, and then performing a rubbing process to impart alignment ability.

  The solvent used when forming the alignment film 20 is appropriately selected according to the material to be used, and examples thereof include acetone, cyclohexanone, toluene, methyl ethyl ketone, ethyl acetate, water, ethanol, isopropyl alcohol, and the like. The solvent used when forming the alignment film 20 is preferably a solvent that does not dissolve the substrate 10. Therefore, it is preferable to select materials with different solvents that dissolve in the alignment film 20 and the substrate 10.

  Drying is performed by heat-treating under conditions according to the solvent used. The drying conditions may be appropriately adjusted depending on the type of solvent used, the film thickness, and the like, but are usually 30 to 200 ° C. and 20 to 60 seconds.

  The thickness of the alignment film 20 is usually 0.3 to 6 μm, preferably 0.6 to 2 μm, and more preferably 0.8 to 1.4 μm. When the thickness is less than 0.3 μm, it tends to be easily affected by defects such as fine scratches on the substrate 10, and when it is thicker than 3 μm, uneven drying tends to occur.

  The alignment treatment of the alignment film 20 can be performed using a known method, but can be broadly classified into a rubbing treatment and another method. As the rubbing process, there is a method of using a rubbing roll 70 as shown in FIG. As other alignment treatment methods, there are a stretching method, an imprinting method, an ultraviolet light aligning device, a soft X-ray aligning device and the like.

  The solvent used in the solvent coating step is not particularly limited as long as the alignment ability of the alignment film 20 can be lost. Usually, a solvent that can dissolve the constituent material of the alignment film 20 is used. As the solvent used in the solvent coating step, the same solvent as that used when forming the alignment film 20 described above may be used, a different solvent may be used, or a plurality of solvents may be used in combination. .

  The solvent coating method is not particularly limited as long as the solvent can be applied to the alignment film 20, and in addition to the method using the stamp 80 as shown in FIG. 1 (c), spraying with a spray, printing with an inkjet printer , Gravure printing, letterpress printing and the like.

  The application amount of the solvent may be an amount that can eliminate the alignment ability of the partial region 22 of the alignment film 20 and is appropriately adjusted.

  After applying a solvent to a partial region 22 of the alignment film 20, the solvent is dried. The drying conditions may be appropriately adjusted depending on the type of solvent used, but are usually 10 to 30 seconds at room temperature.

  The liquid crystal layer 30 can be formed by applying a liquid crystalline composition containing a liquid crystal material on the alignment film 20, aligning the liquid crystal material by heating, and then fixing the alignment. Examples of the liquid crystal material include cholesteric liquid crystal, nematic liquid crystal, and smectic liquid crystal. Among them, cholesteric liquid crystal is preferable from the viewpoint of the visibility of the pattern 32. Hereinafter, the case where the liquid crystal layer 30 is a cholesteric liquid crystal layer will be described in detail.

  The cholesteric liquid crystal layer can be formed using a liquid crystal composition mainly composed of a polymer liquid crystal, a crosslinked low-molecular liquid crystal, or a mixture thereof.

  The polymer liquid crystal is not particularly limited as long as the cholesteric alignment can be fixed, and any of main chain type and side chain type polymer liquid crystals can be used. 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 these, liquid crystalline polyesters are preferred because they have good orientation in forming cholesteric orientation and are relatively easy to synthesize. Preferred examples of the structural unit of the polymer include aromatic or aliphatic diol units, aromatic or aliphatic dicarboxylic acid units, and aromatic or aliphatic hydroxycarboxylic acid units.

  Examples of the crosslinked low-molecular liquid crystal include those having a basic skeleton of a biphenyl derivative, a phenylbenzoate derivative, a stilbene derivative or the like into which a functional group such as an acryloyl group, a vinyl group, or an epoxy group is introduced. In addition, as the cross-linked low-molecular liquid crystal, any of those exhibiting lyotropic properties and those exhibiting thermotropic properties can be used, but those exhibiting thermotropic properties are more preferable from the viewpoint of workability and the like.

  As a method for fixing the cholesteric orientation, a known method can be used. For example, when a polymer liquid crystal is used as the liquid crystal material, a method of fixing the cholesteric alignment by applying a polymer liquid crystal on the alignment film 20 and then developing a cholesteric liquid crystal phase by heat treatment or the like and rapidly cooling from the state. Can be used. In the case of using a crosslinked low-molecular liquid crystal as a liquid crystal material, after applying the crosslinked low-molecular liquid crystal on the alignment film 20, a cholesteric liquid crystal phase is developed by heat treatment or the like, and light, heat, and the like are maintained while maintaining the state. Alternatively, a method of fixing the cholesteric orientation by crosslinking with an electron beam or the like can be appropriately employed.

  In order to improve the heat resistance and the like of the cholesteric liquid crystal layer, a crosslinking agent such as a bisazide compound or glycidyl methacrylate can be added to the liquid crystalline composition in addition to the polymer liquid crystal and the crosslinked low-molecular liquid crystal. By adding these crosslinking agents, crosslinking can be performed in a state where a cholesteric liquid crystal phase is expressed. Furthermore, various additives such as a dichroic dye, a dye, and a pigment can be appropriately added to the liquid crystalline composition.

  The configuration of the liquid crystal layer 30 is usually composed of one liquid crystal layer such as the above-described cholesteric liquid crystal layer, but may be configured by laminating a plurality of liquid crystal layers as necessary.

  The thickness of the liquid crystal layer 30 is usually 0.3 to 20 μm, preferably 0.5 to 10 μm, and more preferably 0.7 to 3 μm. If the thickness is less than 0.3 μm, there is a possibility that a specific optical characteristic effect cannot be effectively expressed, and if it exceeds 20 μm, drying unevenness tends to occur. In addition, when the liquid crystal layer 30 is a laminate of a plurality of liquid crystal layers, it is desirable that the total thickness of all the liquid crystal layers falls within the above range.

  As described above, in the liquid crystal layer 30, a portion where the alignment state of the liquid crystal material is different from the other regions is formed in a region on the partial region 22 where the alignment ability of the alignment film 20 has disappeared. When the liquid crystal layer 30 is composed of cholesteric liquid crystal, the alignment structure of the liquid crystal molecules has a regular twist so as to draw a spiral in the film thickness direction, and the directions of the liquid crystal molecules are aligned in the same plane. On the other hand, the directions of the liquid crystal molecules on the region where the alignment ability is lost are not aligned in the same plane and are random, and a pattern 32 is formed due to the difference in the appearance of the reflected light.

  A translucent protective film 50 is affixed on the liquid crystal layer 30 via an adhesive 40. As the adhesive 40, the liquid crystal layer 30 and the translucent protective film 50 can be bonded, and the adhesive 40 is transparent to the extent that the pattern 32 formed on the liquid crystal layer 30 can be visually recognized through the adhesive 40. If it is not specifically limited, conventionally well-known various adhesives and adhesives can be used. Specifically, a hot melt adhesive, a light or electron beam curable reactive adhesive, or the like can be used as appropriate. Among these, a reactive adhesive is preferable from the viewpoint of workability and the like.

  Although there is no restriction | limiting in particular as a hot-melt-type adhesive agent, From a viewpoint of workability | operativity etc., the working temperature of hot melt is 250 degrees C or less, Preferably it is about 80-200 degreeC, More preferably, about 100-160 degreeC is preferable. Specific examples of hot melt adhesives include ethylene / vinyl acetate copolymer resins, polyester resins, polyurethane resins, polyamide resins, thermoplastic rubber resins, polyacrylic resins, polyvinyl alcohol resins, polyvinyl butyral. A hot melt adhesive having a base resin such as a polyvinyl acetal resin, petroleum resin, terpene resin, rosin resin or the like can be used.

  Examples of reactive adhesives include prepolymers and / or monomers having light or electron beam polymerizability, and other monofunctional or polyfunctional monomers, various polymers, stabilizers, photopolymerization initiators, and sensitization as necessary. An agent or the like can be blended and used.

  Specific examples of the prepolymer having light or electron beam polymerizability include polyester acrylate, polyester methacrylate, polyurethane acrylate, polyurethane methacrylate, epoxy acrylate, epoxy methacrylate, polyol acrylate, and polyol methacrylate. Moreover, as a monomer which has light or electron beam polymerizability, a monofunctional acrylate, a monofunctional methacrylate, a bifunctional acrylate, a bifunctional methacrylate, a trifunctional or more polyfunctional acrylate, a polyfunctional methacrylate, etc. can be illustrated. Moreover, these can also use a commercial item, for example, Aronix (acrylic-type special monomer, oligomer; Toagosei Co., Ltd. product), light ester (manufactured by Kyoeisha Chemical Co., Ltd.), Biscote (Osaka organic chemical industry Co., Ltd.). Etc.) can also be used in the present invention.

  As the photopolymerization initiator, for example, benzophenone derivatives, acetophenone derivatives, benzoin derivatives, thioxanthones, Michler 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 that can be used in the present invention is appropriately selected depending on the processing temperature of the adhesive, etc., and cannot be generally specified, but is usually 10 to 2000 mPa · s at 25 ° C. s, preferably 50 to 1000 mPa · s, more preferably 100 to 500 mPa · s. When the viscosity is lower than 10 mPa · s, it is difficult to obtain a desired thickness. Moreover, when higher than 2000 mPa * s, workability | operativity may fall and it is not desirable. When the viscosity is out of the above range, it is preferable to adjust the solvent and monomer ratio to a desired viscosity as appropriate.

When a photo-curable reactive adhesive is used, a known curing means such as a low-pressure mercury lamp, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a metal halide lamp, or a xenon lamp may be used as a method for curing the adhesive. it can. Further, the exposure amount varies depending on the type of the reactive adhesive to be used and cannot be generally specified, but is usually 50 to 2000 mJ / cm ² , preferably 100 to 1000 mJ / cm ² .

  In addition, when an electron beam curable reactive adhesive is used, the curing method of the adhesive is appropriately selected according to the transmission power and curing power of the electron beam, but it cannot be generally stated, It can be cured by irradiation under an acceleration voltage of 50 to 1000 kV, preferably 100 to 500 kV.

  Although the thickness of the adhesive agent 40 is not specifically limited, Usually, 0.5-50 micrometers, Preferably it is 1-10 micrometers. The adhesive 40 may be formed by a known method such as a roll coating method, a die coating method, a bar coating method, a curtain coating method, an extrusion coating method, a gravure roll coating method, a spray coating method, or a spin coating method. Can be used.

  The translucent protective film 50 is not particularly limited as long as it is transparent to the extent that the pattern 32 formed on the liquid crystal layer 30 through the translucent protective film 50 is visible. For example, triacetyl cellulose (TAC) ), Polymethyl methacrylate, polystyrene, polycarbonate, polyether sulfone, polyphenylene sulfide, amorphous polyolefin, polyethylene terephthalate, polyethylene naphthalate, cycloolefin polymer (COP), polyvinyl alcohol, and the like. The translucent protective film 50 may contain an ultraviolet absorber. The translucent protective film 50 may be a hard coat layer. Moreover, when using as a hard-coat layer, in order to improve the designability, you may contain a bead and metal powder (glitter). Moreover, in order to add the objective of antireflection, you may use an antireflection film as a protective film, or you may form an antireflection layer on a protective film.

  Although the thickness of the translucent protective film 50 is not specifically limited, Usually, 8-200 micrometers, Preferably it is 20-100 micrometers.

  The method of peeling the alignment film 20 and the substrate 10 from the liquid crystal layer 30 is not particularly limited. For example, a method of artificially peeling the alignment film 20 or the substrate 10 by attaching an adhesive tape to the corners or edges of the alignment film 20 or the roll, etc. A method of mechanically peeling using, a method of peeling mechanically after being immersed in a poor solvent for all structural materials, a method of peeling by applying ultrasonic waves in a poor solvent, the alignment film 20 or the substrate 10 and the liquid crystal layer 30 It is possible to use a method of peeling by applying a temperature change utilizing the difference in thermal expansion coefficient.

  The liquid crystal material of a part of the liquid crystal layer and the liquid crystal material of the other part are the same, and the liquid crystal material of the part of the part and the liquid crystal material of the other part are different in the alignment state. However, the optical film of the present invention can be manufactured by another manufacturing method. For example, as shown in FIG. 1A, an alignment film 20 is formed on a substrate 10, and then a mask having an opening in a predetermined region is used to provide alignment ability only to the predetermined region. Install on top. Next, as in the above embodiment, rubbing treatment is performed using a rubbing roll on the mask. By doing so, alignment ability can be imparted only to the alignment film in a predetermined region exposed at the opening of the mask. Next, a liquid crystal composition containing a liquid crystal material is applied onto the alignment film in the same manner as in the above embodiment, the liquid crystal material is aligned by heating, and then the alignment is fixed to form a liquid crystal layer. At this time, since the region other than the predetermined region of the alignment film has no alignment ability, the liquid crystal material is not regularly aligned in the region of the liquid crystal layer located on the region, and the predetermined region is the alignment of the liquid crystal material. Since the states are different, a pattern is formed in the liquid crystal layer. Finally, in the same manner as in the above embodiment, a translucent protective film is attached to the liquid crystal layer via an adhesive, and the alignment film and the substrate are peeled off from the liquid crystal layer to obtain a liquid crystal layer / adhesive / translucency. An optical film made of a protective film can be obtained.

In addition, the surface of the alignment layer can be similarly treated by performing surface treatment of the alignment film using a method such as direct drawing with CO ₂ laser light, excimer UV irradiation using a mask, or electron beam (EB) drawing. Regions with different orientation states can be formed.

  The optical film 100 composed of the liquid crystal layer 30 / adhesive 40 / translucent protective film 50 can be used for anti-counterfeiting, decoration and the like. The optical film 100 can be used by applying an adhesive or the like on the liquid crystal layer 30 side and affixing it to a label, tag, decorative box, packing material, packaging material, or the like. These may have a design. In addition, as will be described in detail in an embodiment described later, the optical film 100 is applied with an adhesive layer such as a hot melt agent or an electromagnetic wave curable resin on the liquid crystal layer 30 side, and then the adhesive layer side is in contact with an article such as a label. Then, it can be adhered to an article such as a label by irradiating it with a hot stamp or electromagnetic wave from the translucent protective film 50 side. Moreover, the reuse by peeling a film using a solvent can be prevented by using a low solvent-resistant member, such as a COP film, for the translucent protective film 50. Water-soluble films can be used for the same purpose. Furthermore, the adhesive 40 and the translucent protective film 50 can be peeled off and used as a transfer foil.

  Note that different members (hereinafter referred to as back surface members) can be formed or attached for various purposes on the outermost surface of the optical film 100 on the liquid crystal layer 30 side, that is, on the back side of the liquid crystal layer 30. Specific examples of the back member are illustrated below.

(1) Colored back member “Back member” (label, tag, etc.) to be bonded to the liquid crystal layer 30 side or the design color provided on them is black (green), white (red), blue (blue), etc. The visual color is also different by changing to the color. For example, it is assumed that the liquid crystal layer 30 is made of a liquid crystal material that reflects green right circularly polarized light. In this case, when the color of the back member is black, the color when viewed from the front side of the liquid crystal layer (strictly, the color viewed by peeling off the adhesive and the translucent protective film) is green. When the member is white, it looks a complementary red color. When the back member is blue, it looks blue. Therefore, by changing the color of the back surface member, it is possible to represent RGB colors while being a monochromatic optical film. When an optical film having such a back member is observed through a left circular polarizing filter of a viewer described later, the design of the liquid crystal layer disappears, and only the design and color of the back member can be seen.

(2) Back member having a concavo-convex structure with a slope The back member may have a concavo-convex structure having a slope on its surface. The concavo-convex structure has a size of nano to millimeter units and can be formed by a known method such as a nanoimprint method or embossing. When the incident light has an incident angle θ, light having a wavelength λ that satisfies the Bragg reflection condition (p is the thickness of the back member and n is the refractive index of the back member) of p · cos θ = λ / n. Reflected selectively by diffraction. Therefore, a shorter wavelength color is observed than when observing at an angle. The light of wavelength λ diffracted in the front direction by the inclined irregularities on the back surface passes through the spiral structure of the liquid crystal, so that even when viewed from the front, the same effect as that observed at an angle can be obtained, and multicolor Can be expressed. By adjusting the tilt angle, colorization is possible, which has the effect of improving the design.

(3) Back member as retardation member A retardation film formed by a liquid crystal layer (nematic liquid crystal) or an uneven structure may be laminated as a back member, and a reflective layer may be provided thereon. By providing the reflective layer, the reversely twisted circularly polarized light that has been transmitted returns, so that the design of the cholesteric layer does not disappear with the circularly polarizing plate (and the linearly polarizing plate). On the other hand, the retardation film is transparent to the naked eye, but can be colored and recognized when viewed through a linear polarizing plate. Moreover, when a retardation film is arrange | positioned under a cholesteric liquid crystal, the non-orientation part of a cholesteric liquid crystal can recognize a retardation film part in the state without a polarizing plate.

(4) Back member as a mirror member A back member composed of a transparent member (glass, film) / reflecting portion may be used. The reflection portion may be the entire surface or may be partially formed. If there is a reflection part, the design will not disappear with a viewer using a circular polarizing filter. You may write patterns and letters on the backboard with high reflectivity such as aluminum foil. Alternatively, a pattern may be written on the aluminum foil with, for example, black ink. When the right circular polarizing filter of the viewer is used, only the letters written on the aluminum foil disappear. When the transparent member is thick, when observed at an angle, the reflection image on the surface of the transparent member and the reflection image on the reflection portion are misaligned, and the pattern of the cholesteric liquid crystal layer appears to be lifted up visually (pseudo). 3D pattern). Thereby, the designability improves. The various back members as described above can be formed from materials such as PET, COP, and TAC.

  The optical film of the present invention has a very wide application and can be used as various optical elements, optoelectronic elements, decorative members, anti-counterfeiting elements, and the like. In particular, it can be used as a new film, a seal, a label or the like having both the effects of the diffraction element and the cholesteric liquid crystal. For example, it can be attached to or embedded in a support substrate such as a car driver's license, identification card, passport, credit card, prepaid card, various types of cash vouchers, gift cards, securities, etc. Further, it can be affixed to products such as a battery, a camera, a calculator, and a watch as a seal. As a label, for example, it can be used as a fiber label sewn on clothes such as a tie or shirt.

  In particular, when used as an anti-counterfeiting element, a viewer 120 as shown in FIG. 11 is usually used to confirm that the optical film or the transferred product transferred from the optical film is authentic. At the two openings of the viewer 120, a right circular polarization filter 120a that passes only right circular polarization and a left circular polarization filter 120b that passes only left circular polarization are attached. Here, it is assumed that the liquid crystal layer of the optical film 100 of the embodiment mounted on the support 130 such as a card is made of a liquid crystal material that reflects only right circularly polarized light. When natural light is irradiated on the optical film 100 with a polarization component in a random direction, only right circularly polarized light is reflected from the liquid crystal layer of the optical film 100, and the reflected light passes through the right circular polarizing filter 120a of the viewer 120. Therefore, the design and design attached to the liquid crystal layer can be seen through the right circular polarization filter 120a. On the other hand, the right circularly polarized light reflected from the liquid crystal layer cannot pass through the left circular polarizing filter 120b, so that the design and design attached to the liquid crystal layer cannot be seen. For the purpose of discrimination only, only a circularly polarizing filter in the rotation direction in which the design cannot be seen may be used.

  Hereinafter, examples of the optical film of the first embodiment will be described more specifically, but the present invention is not limited to the following examples.

Example 1
A PET (polyethylene terephthalate) film was used as the substrate. The PET film has orientation ability and also serves as an orientation film. A stamp with toluene attached to a PET film was pressed for 0.2 seconds at a pressure of 10 kPa, and then dried at room temperature for 15 seconds.

  Nematic liquid crystal (PALIOCOLOR LC242 manufactured by BASF Corp.) 19.0% by weight, chiral agent (manufactured by PALIOCOLOR LC756 BASF Corp.) 1.0% by weight, acylphosphine oxide photopolymerization initiator (IRGACURE TPO BASF Corp.) (Manufactured) A solution consisting of 0.8% by weight and 79.2% by weight of cyclohexanone was applied on a PET film so that the thickness after drying was 1.6 μm, and dried by heating in a drying furnace at 55 ° C. for 15 minutes. I let you. Next, the liquid crystal is aligned by leaving it in a heat treatment furnace heated to 100 ° C. for 10 minutes and in a heat treatment furnace heated to 80 ° C. for 10 minutes, and light is irradiated by an LED-UV lamp to fix the alignment, and a cholesteric liquid crystal layer is formed. Formed.

  A PC (polycarbonate) film is pasted on the liquid crystal layer via an ultraviolet curable adhesive (trade name: Aronix UV-3630, manufactured by Toagosei Co., Ltd.), and the adhesive is applied by light irradiation with a high-pressure mercury lamp. Cured. Thereafter, the PET film was peeled from the liquid crystal layer to obtain an optical film composed of a liquid crystal layer / adhesive / PC film.

(Example 2)
On a PEN (polyethylene naphthalate) film, a solution composed of 4% by mass of PVA (polyvinyl alcohol), 76.8% by mass of pure water, and 19.2% by mass of IPA (isopropyl alcohol) was 1.2 μm in thickness after drying. And then dried for 36 seconds in a drying furnace that gradually increases in temperature from 40 ° C. to 130 ° C. to form a PVA film. A low-density polyethylene film having a thickness of 30 μm cut out in a letter shape was attached to the PVA film, and a rubbing treatment was applied using a rubbing roll to which a rubbing cloth was attached to form an alignment film.

  In the same manner as in Example 1, a cholesteric liquid crystal layer was formed on the alignment film. Further, a TAC film was attached on the liquid crystal layer in the same manner as in Example 1 except that a TAC (triacetylcellulose) film was used instead of the PC film. Thereafter, the alignment film and the PEN film were peeled from the liquid crystal layer to obtain an optical film composed of a liquid crystal layer / adhesive / TAC film.

(Example 3)
An alignment film was formed in the same manner as in Example 2 except that the entire PVA film was rubbed without using a polyethylene film cut out in a letter shape.

  The solvent was applied to the alignment film by pressing a stamp with a mixed solvent of water and ethanol (water: ethanol = 2: 1 (mass ratio)) on the alignment film at a pressure of 1 kPa for 0.2 seconds. . Thereafter, the portion coated with the solvent was dried at room temperature for 15 seconds.

  In the same manner as in Example 1, a cholesteric liquid crystal layer was formed on the alignment film. Further, in the same manner as in Example 2, a TAC film was stuck on the liquid crystal layer. Thereafter, the alignment film and the PEN film were peeled from the liquid crystal layer to obtain an optical film composed of a liquid crystal layer / adhesive / TAC film.

  It was confirmed that the pattern of the stamp was formed in the liquid crystal layer of the optical film obtained in Examples 1-3. The pattern formed on the optical film was clear and easily visible. Moreover, the occurrence of damage to the liquid crystal layer was not confirmed.

  The optical film 100 according to the first embodiment includes the liquid crystal layer 30 / the adhesive 40 / the translucent protective film 50, and the liquid crystal layer 30 is formed with a portion in which the alignment state of the liquid crystal material is different from other regions. A design that brings about designability was formed. However, the optical film of the present invention is not limited to the structure and usage method of the optical film 100 of the first embodiment, and can take various forms as listed below.

Second Embodiment In the first embodiment, the pattern is formed according to the orientation state of the liquid crystal material of the liquid crystal layer. However, in order to further increase the design of the pattern, the lower surface of the liquid crystal layer 30 as in the optical film 102 shown in FIG. An uneven pattern 60 for generating a hologram may be provided. The concavo-convex pattern 60 is provided so as to cover both the portion 30a where the orientation of the liquid crystal material of the liquid crystal layer 30 has disappeared and the portion 30b where the orientation is maintained. The light passing through the liquid crystal layer 30 and reaching the concave / convex pattern 60 generates diffracted light according to the pitch and incident angle of the concave / convex pattern 60. Since this diffracted light passes through the liquid crystal layer 30, it has optical rotation characteristic of the liquid crystal layer. That is, when the liquid crystal layer is a cholesteric liquid crystal that reflects right circularly polarized light, the diffracted light also becomes right circularly polarized light. Therefore, when the optical film 102 is observed with the right circular polarization filter 120a as shown in FIG. 11, a hologram having a color corresponding to a diffraction pattern such as a rainbow color can be observed. Furthermore, the pattern formed by the part 30a and the part 30b can also be observed. On the other hand, even if the optical film 102 is observed with the left circular polarizing filter 120b, it becomes a dark field and neither diffracted light nor a pattern can be observed.

  By configuring in this way, not only the presence / absence of the orientation of the liquid crystal layer 30 but also the design can be increased by diffracted light such as a hologram generated from the concavo-convex pattern 60. The uneven pattern can be formed by any method such as embossing or nanoimprinting. An adhesive layer such as an adhesive seal, a release paper, a protective film, a base material, and the like may be further provided on the lower surface of the uneven pattern 60.

3rd Embodiment In 2nd Embodiment, although the uneven | corrugated pattern 60 was formed in the lower surface of the liquid crystal layer 30, the reflective layer 72 which has the uneven | corrugated pattern 60 in the lower surface was provided in the liquid crystal layer 30 like the optical film 103 shown in FIG. May be. The reflective layer 72 may be made of a cholesteric liquid crystal material that reflects right circularly polarized light. Similar to the second embodiment, when the optical film 103 is observed with the right circular polarizing filter, in addition to the diffracted light of the color corresponding to the diffraction pattern such as rainbow, the pattern formed by the portions 30a and 30b is also observed. However, even if the optical film 103 is observed with the left circular polarizing filter, it becomes a dark field, and neither the diffracted light nor the pattern can be observed. By configuring in this way, not only the presence / absence of the orientation of the liquid crystal layer 30 but also the design can be increased by diffracted light such as a hologram generated from the concavo-convex pattern 60. A protective film or a base material may be further provided on the lower surface of the reflective layer 72.

Fourth Embodiment In the first embodiment, one liquid crystal layer is provided, but a second liquid crystal layer 32 may be provided on the lower surface of the liquid crystal layer 30 as in the optical film 104 shown in FIG. In this case, the portion 32a where the orientation of the liquid crystal material of the second liquid crystal layer 32 disappears and the portion 32b where the orientation is maintained maintain the orientation with the portion 30a where the orientation of the liquid crystal material of the liquid crystal layer 30 disappears. The position in the in-layer direction may be shifted with respect to the portion 30b. The liquid crystal layer 30 and the second liquid crystal layer 32 may have different colors of reflected light by changing the pitch and refractive index of the layered structure of the liquid crystal material. For example, the liquid crystal layer 30 is made of a liquid crystal material that reflects red in front reflection and the second liquid crystal layer 32 reflects blue in front reflection. In this case, the optical film 104 looks purple when observed from the front with the naked eye. On the other hand, when the optical film 104 is observed with a right circular polarizing filter composed of the same liquid crystal material as the liquid crystal layer 30, red appears, and when the optical film is observed with a right circular polarizing filter composed of the same liquid crystal material as the liquid crystal layer 32, it appears blue. . By doing so, the designability can be increased.

  Instead of making the reflection colors of the liquid crystal layer 30 and the second liquid crystal layer 32 different as described above, the optical rotation of the circularly polarized light reflected by the liquid crystal layer 30 and the second liquid crystal layer 32 may be reversed. For example, the respective liquid crystal materials are adjusted so that the liquid crystal layer 30 reflects right circularly polarized light and the second liquid crystal layer 32 reflects left circularly polarized light. Then, when the optical film 104 is observed with the right circular polarizing filter, only the patterns (30a, 30b) formed with or without orientation appear to appear on the liquid crystal layer 30, and when the optical film 104 is observed with the left circular polarizing filter, the liquid crystal Only the patterns (32a, 32b) formed by the presence or absence of orientation in the layer 32 appear to be raised. In this case, when a single combination or a superposed pattern is generated between the pattern of the liquid crystal layer 30 and the pattern of the second liquid crystal layer 32, the visual design is improved.

  The liquid crystal layer is not limited to two layers, and may be a plurality of three or more layers. Further, a plurality of liquid crystal layers as in the present embodiment may be introduced into the optical film having the uneven pattern of the second or third embodiment.

Fifth Embodiment In the first embodiment, the pattern is formed according to the alignment state of the liquid crystal material of the liquid crystal layer. However, in order to further increase the design of the pattern, the lower surface of the liquid crystal layer 30 is used like the optical film 105 shown in FIG. A printing layer 82 may be provided on the substrate. The printed layer 82 can be provided with a logo or design of a manufacturer or a trader of an article to which the optical film 105 is attached. Further, a photograph may be attached to the print layer 82 instead of or in addition to the logo or the design. The print layer 82 may be made of a material that does not have polarization or optical rotation so that it can be visually recognized. If the liquid crystal layer 30 of the optical film 105 is made of a liquid crystal material that reflects right circularly polarized light, When the optical film 105 is observed with the left circular polarizing filter, the logo and design of the printed layer 82 can be observed, but the pattern (30a, 30b) formed by the presence or absence of orientation on the liquid crystal layer 30 is not visible, and the optical film is displayed with the right circular polarizing filter. When 105 is observed, a pattern (30a, 30b) formed on the liquid crystal layer 30 with or without orientation can be seen, but the logo and design of the print layer 82 are hidden behind the liquid crystal layer 30 (by reflected light from the liquid crystal layer 30). Become invisible.

  The print layer 82 can also be configured using thermochromic ink or photochromic ink. By doing so, a color change can be caused in the print layer 82 by heating or light irradiation, and the distinguishability can be increased.

  By providing such a printed layer 82 in the lowermost layer of the optical film of the first to fourth embodiments, the decorativeness can be further increased. For example, a printed layer having a pattern can be provided on the lower surface of the concave / convex pattern of the optical film of the second or third embodiment. In that case, the pattern and the concave / convex pattern of the hologram may be formed to coincide with each other. By doing so, the design and the design are improved by making the design and the hologram pattern appear to overlap each other when observing through the viewer.

Sixth Embodiment Instead of the printing layer 80 provided in the fifth embodiment, a light absorption layer 90 may be provided in the lowermost layer as in the optical film 106 shown in FIG. By providing the light absorption layer 90, the reflected light from the article below the liquid crystal layer 30 can be prevented, and the pattern depending on the alignment state of the liquid crystal material of the liquid crystal layer can be seen more easily and vividly. The light absorption layer 90 can be a black printing layer made of, for example, a pigment or a dye. The light absorption layer 90 may cover the entire surface of the liquid crystal layer 30 or may be provided on the lower surface of the liquid crystal layer 30 so as to partially cover. By partially providing the light absorption layer 90 on the lower surface of the liquid crystal layer 30 in a specific pattern, a design by the light absorption layer 30 occurs. As the light absorption layer 90, not only a material that absorbs visible light but also a material that absorbs ultraviolet light may be used as the ultraviolet absorption layer. In addition, you may provide the light absorption layer 90 in the lowest layer of the optical film of 1st Embodiment-5th Embodiment.

7th Embodiment Although the optical film 100 of 1st Embodiment had the laminated structure of the liquid crystal layer 30 / adhesive 40 / protective film 50, like the optical film 107 shown in FIG. A light transmissive decorative layer 92 may be provided between the liquid crystal layers 30. The decoration layer 92 may be a colored light-transmitting layer or a film with a logo or design in plan view. The decorative layer 92 has such a thickness that the circularly polarized reflected light from the liquid crystal layer 30 is transmitted through the viewer 120 as shown in FIG. 11 and the pattern depending on the alignment state of the liquid crystal material of the liquid crystal layer can be recognized. It is desirable to maintain transmittance. By doing so, the design properties can be enhanced by the optical film 100. The decoration layer 92 can be formed of any material such as a light-transmitting polymer, and is fixed between the liquid crystal layer 30 and the protective film 50 via the adhesive 40.

  Instead of providing the decorative layer 92, the design and color may be applied directly to the protective film 50 of the optical film 100 of the first embodiment. In this case, printing may be performed on the surface of the protective film, or the protective film 50 may be formed of another material by adding a pigment or a glossy powder.

Eighth Embodiment In the second embodiment, the concave / convex pattern 60 is provided on the lower surface of the liquid crystal layer 30, but the optical film 108 of this embodiment has a partial area as shown in FIG. 8, for example, the left half area. The uneven pattern 60 is provided only on the lower surface of the liquid crystal layer 30 of 108a, and the region 30a having a different alignment state is provided only on the liquid crystal layer 30 of the right half region 108b. Thus, when the liquid crystal layer 30 is made of a liquid crystal material that reflects right circularly polarized light, the optical film 108 is observed through the right circularly polarizing filter 120a as shown in FIG. A hologram pattern due to the generated diffracted light can be observed, and a pattern generated by the region 30a having a different alignment state can be visually recognized from the region 108b. Therefore, the design can be further enhanced when both of these patterns and the hologram pattern can be observed from the respective regions.

Ninth Embodiment In the fifth embodiment, the printing layer is provided on the lower surface of the liquid crystal layer. However, the optical film 109 shown in FIG. 9 has a partial area, for example, the left half area 109a in place of the liquid crystal layer 30. Is provided with a printed layer 84 having a printed pattern 84a, and the liquid crystal layer 30 is provided only in the right half region 109b. A region 30 a having a different alignment state is provided only in a part of the liquid crystal layer 30. The liquid crystal layer 30 is made of a liquid crystal material that reflects right circularly polarized light. When the optical film 109 is viewed from the front, the printed pattern 84a of the printing layer 84 can be seen from the region 109a, and the pattern of the region 30a having a different liquid crystal alignment state can be seen from the region 109b. Further, when the optical film 109 is observed through the right circular polarizing filter, a printed pattern can be seen from the region 109a, and a pattern by the region 30a having a different orientation state can be seen from the region 109b. When the optical film 109 is observed through the left circular polarizing filter, a printed pattern is seen from the region 109a, and the region 109b is a dark field. Note that the print layer 30 and the liquid crystal layer 30 may be the same color, and by doing so, the difference between the observation through the visual and right circular polarizing filters and the observation through the left circular polarizing filter becomes more apparent.

Tenth Embodiment FIG. 10 shows a modification of the second embodiment. In the second embodiment, the concave / convex pattern 60 is formed on the lower surface of the liquid crystal layer 30, but in the optical film 110 shown in FIG. 10, the concave / convex pattern 60 that generates a hologram pattern between the liquid crystal layer 30 and the protective film 50 is formed. An intermediate layer 94 is provided. The uneven pattern 60 is provided on the surface where the intermediate layer 94 faces the liquid crystal layer 30. The intermediate layer 94 can be made of, for example, a cholesteric liquid crystal material that reflects the same right circularly polarized light as the liquid crystal layer 30. In this case, when the optical film 110 is viewed from the front, the hologram pattern formed by the concavo-convex pattern 60 can be observed. On the other hand, due to the color shift of the liquid crystal layer 30 observed from an oblique direction, the pattern due to the alignment state of the liquid crystal material appears colored.

Eleventh Embodiment FIG. 12 shows an optical film 112 provided with a microlens array 150 instead of the protective film on the liquid crystal layer 30 of the optical film of the first embodiment. The microlens array 150 is formed by arranging a plurality of microlenses 150a on the liquid crystal layer 30 like a grid, and each lens has a diameter of, for example, several μm. The pattern formed by the regions 30a and 30b having different alignment states of the liquid crystal layer 30 is a pattern formed by forming a predetermined three-dimensional image through the microlens array 150 in advance. By observing the pattern formed in this way through the microlens array 150, it can be seen as a three-dimensional stereoscopic image. By forming the microlens array 150 using acrylic or the like so that birefringence does not occur, an image that can be seen only through the right circular polarization filter through the viewer viewer can be seen three-dimensionally. Can do.

Twelfth Embodiment FIG. 13 shows an optical film 114 provided with a lenticular lens array 160 instead of the protective film on the liquid crystal layer 30 of the optical film 100 of the first embodiment. The lenticular lens array 160 is formed by arranging a plurality of semi-cylindrical lenticular lenses 160a in a predetermined direction on the liquid crystal layer 30, and each lenticular lens has a lateral width of several μm to several mm, for example. The region of the liquid crystal layer 30 below each lenticular lens 160a is divided into, for example, regions α, β, and γ as shown in FIG. 13, and the liquid crystal layer 30 is formed in each of the regions α, β, and γ. The pattern which becomes a unit is formed by the regions 30a and 30b having different orientation states. One symbol is formed by combining a group of symbols in the region α. The same applies to the symbols of the region β and the region γ. By doing this, when the lenticular lens array 160 is viewed from a specific direction (a specific angle with respect to the optical axis of the lenticular lens array 160), only the pattern by the region α can be observed. In addition, when the lens array 160 is viewed from the front, only the pattern by the region β can be observed. In addition, when the lenticular lens array 160 is viewed from the direction opposite to the normal line when the pattern of the area α is seen, the pattern of the area γ can be observed. That is, different symbols can be observed depending on the viewing direction. Therefore, by forming the lenticular lens array 160 so that birefringence does not occur, an image viewed through the right circular polarization filter through the viewer looks different depending on the viewing direction, so that the design of the design can be increased. The symbols recorded in the regions α, β, and γ may be symbols such as moving images that are continuously connected depending on the viewing direction, or symbols that appear three-dimensionally.

Thirteenth Embodiment A pattern may be formed on the upper or lower layer of the translucent protective film 50 of the optical film 100 of the first embodiment using IR ink, UV ink, or the like. The pattern formed with these inks absorbs infrared rays or ultraviolet rays and develops color, and thus cannot be visually observed, but can be detected using infrared rays or ultraviolet rays. By doing this, the design of the liquid crystal layer can be detected by visible light with a viewer, and further, the design of IR ink or UV ink can be detected by irradiating with infrared rays or ultraviolet rays, so a detection method can be applied in two stages. it can. In this case, it is desirable to form the pattern made of IR ink or UV ink from a material that transmits visible light. Such a form for forming a pattern using IR ink, UV ink, or the like may be used not only in the first embodiment but also in combination with any of the optical films of the above-described embodiments.

The fourteenth embodiment The optical film of the present invention is suitable for various applications as described above, but the act of peeling off the optical film once attached to an article such as a product and attaching it to another article, It is desirable to be able to prevent reuse. FIGS. 14A to 14E show an example of a process for manufacturing an optical film that can prevent such reuse and transferring the liquid crystal layer of the optical film to an article (transfer object).

  The laminated body shown in FIG. 14A is a laminated body obtained in the liquid crystal forming step (FIG. 1D) of the process shown in FIG. 1, and the alignment of the liquid crystal layer is fixed by the alignment film on the substrate. And the design is formed. In the first embodiment, a translucent protective film is attached to this laminate through an adhesive, but in this example, a separator is attached through an adhesive layer to form a laminate as shown in FIG. Get the body. Next, the alignment film of the laminate is peeled off and removed together with the substrate to obtain a laminate comprising a liquid crystal layer / glue layer / separator as shown in FIG. Since this laminated body can be attached to various useful articles by peeling the separator later, it becomes a product form as a transfer sealing material. Note that a protective film may be provided on the surface of the liquid crystal layer (on the opposite side of the adhesive layer) in order to protect the exposed surface of the liquid crystal layer of the laminate shown in FIG. Next, as shown in FIG. 14 (d), the separator is peeled off from this laminated body and attached to the article. Thus, as shown in FIG. 14E, the liquid crystal layer could be transferred to the article via the separator. In addition, when a protective film is provided on the surface of the liquid crystal layer of the laminate as shown in FIG. 14C, the laminate can be peeled off after being attached to an article. Here, since the liquid crystal layer 30 can be manufactured as an extremely thin film such as 0.3 to 9.0 [mu] m, particularly 0.3 to 6.0 [mu] m as described above, the liquid crystal layer is more than the peeling force of the adhesive layer. The breaking strength is low, the adhesive layer is elastically deformed, and the liquid crystal layer is destroyed. Therefore, it is impossible to reuse the optical film having the liquid crystal layer.

  In the process shown in FIGS. 14A to 14E, as a separator, an olefin resin such as polyethylene, polypropylene, 4-methylpentene-1 resin, polyamide, polyimide, polyamideimide, polyetherimide, polyetherketone, Polyether ether ketone, polyether sulfone, polyketone sulfide, polysulfone, polystyrene, polyphenylene sulfide, polyphenylene oxide, polyethylene terephthalate (PET), polybutylene terephthalate, polyarylate, polyacetal, uniaxially stretched polyester, polycarbonate, polyvinyl alcohol, polymethyl methacrylate, Polyarylate, amorphous polyolefin, norbornene resin, uniaxially oriented polypropylene film (OP ) Any material films such as such as triacetyl cellulose (TAC) or epoxy resin. As triacetyl cellulose (TAC), saponified triacetyl cellulose (TAC) as disclosed in JP-A No. 2004-138697 can also be used.

  The adhesive may be any pressure-sensitive adhesive or adhesive as long as it adheres to the liquid crystal layer and allows the separator to be peeled off, and may be a material that requires post-processing such as curing by hot stamping or UV irradiation. Absent. In addition, you may use the transfer tape with a double-sided separator to which the adhesive agent has already adhered as a separator, for example, 467MP, 9458, 9626, etc. by 3M company.

Fifteenth Embodiment FIGS. 15 (a) to (h) and (h ′) show a modification of the process described in the fourteenth embodiment. The laminate shown in FIG. 15A is a laminate obtained in the liquid crystal forming step (FIG. 1D) of the process shown in FIG. 1, and the orientation of the liquid crystal layer is fixed by the orientation film on the substrate. And the design is formed. An adhesive layer is formed on the surface of the liquid crystal layer of such a laminate as shown in FIG. As the adhesive layer, a hot melt adhesive or a light or electron beam curable reactive adhesive is suitable. As will be described later, the adhesive layer can be selected depending on whether it is left or not left on the liquid crystal layer after the laminate is finally attached to the article. Next, as shown in FIG. 15C, the separator 1 is attached on the adhesive layer. As the separator 1, the same material as the separator used in the fourteenth embodiment can be used. Next, the light distribution layer of this laminate is peeled off and removed together with the substrate to obtain a laminate comprising liquid crystal layer / adhesive layer / separator 1 as shown in FIG. On the exposed liquid crystal layer of this laminate, as shown in FIG. 15 (e), a separator 2 is attached via a glue layer to form a laminate of separator 2 / glue layer / liquid crystal layer / adhesive layer / separator 1. Get the body.

  Since this laminated body can be attached to various useful articles by peeling the separator 1 and the separator 2 later, it can be made into a product form as a sealing material. When this laminate is attached to the article, the separator 2 is peeled off as shown in FIG. 15 (g) and attached to the article via the paste of the laminate. Finally, the separator 1 is peeled off leaving the adhesive, and the form shown in FIG. 15 (h) is obtained. By leaving the adhesive on the outermost surface, it can function as a protective film for the liquid crystal layer to give heat resistance and light resistance, and it can be re-peeled after being attached to the article using the thickness and strength of the adhesive layer. It may be possible.

  Instead of peeling the separator 1 from the adhesive layer, as shown in FIG. 15 (h ′), the separator 1 can be peeled together with the adhesive so that only the liquid crystal layer remains on the article via the adhesive layer. . In this case, since the liquid crystal layer 30 can be an extremely thin film of about 1 to 3 μm as described above, such a thin film cannot be easily peeled off from the article, and the liquid crystal layer 30 is forcibly peeled off. In this case, the liquid crystal layer itself is broken. Therefore, it is impossible to reuse the optical film. Whether the adhesive layer is left (FIG. 15 (h)) or not (FIG. 15 (h ′)) depends on the relationship between the adhesive force of the adhesive layer to the separator 1 and the adhesive force of the adhesive layer to the liquid crystal layer. This can be determined by selecting the material of the adhesive layer in consideration of the above.

  Regarding separator 1, separator 2, glue, and adhesive used in the optical films of the fourteenth and fifteenth embodiments, re-peeling in JP-A Nos. 2003-121634, 2004-117522, and 2004-138597 Various materials have been disclosed as adhesive substrates or separate films, and adhesives or pressure-sensitive adhesives for adhering them to liquid crystalline materials, and these can also be used.

  14A to 14E and FIGS. 15A to 15H and 15H 'show examples using alignment films as in the first embodiment, but the substrate itself is A substrate having orientation may be used. In this case, the alignment film can be omitted.

  As mentioned above, although the optical film of this invention was demonstrated by various embodiment, the characteristic structure and arrangement | positioning demonstrated by each embodiment can also be integrated in another embodiment.

  For example, the intermediate layer 94 described in the tenth embodiment may be provided so as to cover the upper surfaces of the printing layer 84 and the liquid crystal layer 30 of the ninth embodiment. In this case, it is not necessary to provide the intermediate layer 94 with a region having a different alignment state only in part, and not to provide the region 30a with a different alignment state in the liquid crystal layer 30 adjacent to the printing layer 84. When the liquid crystal layer 30 is not provided with the regions 30a having different alignment states, the liquid crystal layer 30 does not need to be manufactured by the above-described method, and uses liquid crystal ink in which small pieces of cholesteric liquid crystal are dispersed in an ink vehicle. May be configured.

  Moreover, you may provide the printing layer 82 demonstrated in 5th Embodiment, or the light absorption layer 90 demonstrated in 6th Embodiment in the lowermost surface of the optical film of another embodiment.

  In the description of the second embodiment, it has been described that an adhesive layer such as an adhesive seal, a release paper, a protective film, a base material, and the like can be further provided on the lowermost surface (uneven pattern 60) of the optical film 102. Similarly, an adhesive layer such as an adhesive seal, a release paper, a protective film, a base material, and the like may be provided for the optical film in the form. The support is not limited to a plastic film such as TAC or PET, but may be a woven or non-woven fabric such as a fiber label attached to clothes such as a shirt.

  In the optical film of the above-described embodiment, the pattern or design is formed by the regions 30a and 30b in which the alignment state of the liquid crystal material of the liquid crystal layer is different from each other, but the dot pattern, barcode pattern, QR code (registration) 30a or region 30b. By using the trademark, it is possible to impart information to those patterns and codes. By doing so, information such as the product number and the date of manufacture of the optical film itself or the article to which the optical film is attached can be attached.

  The shape, size, and thickness of the optical film are arbitrary, and slits (cuts) for preventing replacement of the optical film may be provided in a part of the optical film, and the optical film is opened like a donut shape. A part may be formed.

  As a material constituting each layer of the optical film described in the embodiment, any material can be used as long as it functions as the layer. For example, an additive such as a pigment or a light reflector that brings decoration or coloring to the liquid crystal layer or the protective film can be added. The liquid crystal material can be composed of not only a material that reflects visible light but also a liquid crystal material that reflects only infrared light. In this case, the liquid crystal layer of the optical film is visually transparent. In order to observe that such an optical film is authentic, it is only necessary to irradiate the optical film with infrared rays and detect the reflected infrared rays with an infrared sensor. At this time, the reflected light may be converted into linearly polarized light by the λ / 4 plate and then received through a polarizing filter that passes the linearly polarized light.

  The above-described embodiments are merely examples, and modifications that those skilled in the art can conceive may be added to these embodiments.

  DESCRIPTION OF SYMBOLS 10 ... Board | substrate, 20 ... Orientation film, 22 ... Some area | regions (solvent application part), 30 ... Liquid crystal layer, 32 ... Design, 40 ... Adhesive, 50 ... Translucent protective film, 60 ... Concave / convex pattern, 70 ... Rubbing roll, 72 ... reflective layer, 80 ... stamp, 82, 84 ... printed layer, 90 ... light absorbing layer 92 ... decorative layer, 94 ... intermediate layer, 100, 102-110 ... optical film, 120 ... viewer, 130 ... support body

Claims (15)

An optical film having a liquid crystal layer,
A liquid crystal material in a partial region of the liquid crystal layer is the same as a liquid crystal material in another region, and the liquid crystal material in the partial region and the liquid crystal material in the other region are different in alignment state. Optical film.   The optical film according to claim 1, wherein the liquid crystal material in a partial region of the liquid crystal layer is not regularly aligned.   The optical film according to claim 1, wherein the liquid crystal layer is a continuous film formed by applying a liquid crystal material on an alignment film.   The optical film according to claim 1, wherein the liquid crystal material is a cholesteric liquid crystal.   Furthermore, a protective film is provided, The optical film as described in any one of Claims 1-4 characterized by the above-mentioned.   The optical film according to any one of claims 1 to 4, further comprising a separator that can be peeled off via a glue layer on a surface of the liquid crystal layer.   The optical film according to claim 6, further comprising another separator that can be peeled off via an adhesive layer on a surface of the liquid crystal layer opposite to the adhesive layer.   The optical film according to claim 6 or 7, wherein the separator is peeled off from the adhesive layer, and the liquid crystal layer is attached to an article via the adhesive layer.   The optical film according to any one of claims 1 to 8, further comprising a microlens array.   Furthermore, a lenticular lens array is provided, The optical film as described in any one of Claims 1-8 characterized by the above-mentioned.   The optical film according to claim 1, wherein a region exhibiting diffractive power is formed in the liquid crystal layer.   Furthermore, the optical film as described in any one of Claims 1-11 provided with the layer which shows diffraction power.   The optical film according to claim 1, further comprising a printed layer under the liquid crystal layer.   Furthermore, a back surface member is provided, The optical film as described in any one of Claims 1-13 characterized by the above-mentioned.   An article provided with the optical film according to any one of claims 1 to 14.

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