JP2018005119A - Optical film and production method of optical film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a production method for easily producing an optical film imparted with a designing property without damaging a liquid crystal layer.SOLUTION: A production method of an optical film 100 having a liquid crystal layer 30 is provided, and the method includes: an alignment treatment step of imparting a liquid crystal aligning ability to a film; a first liquid crystalline composition application step of applying a first liquid crystalline composition comprising a first liquid material having a rotational property in a first direction on a first region 34 on a film 20 subjected to the alignment treatment; a second liquid crystalline composition application step of applying a second liquid crystalline composition comprising a second liquid crystal material having a rotational property in a second direction different from the first direction in a second region 43 of the film 20 subjected to the alignment treatment, not overlapping the first region 34; and a liquid crystal alignment step of aligning the first liquid crystal material and the second liquid crystal material by heating and then fixing the alignment to form the liquid crystal layer 30.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an optical film having a cholesteric liquid crystal layer and a method for producing the same.

  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 by, for example, a method of irradiating the cholesteric liquid crystal layer with ultraviolet rays in a pattern through a photomask having slits in a pattern (see, for example, Patent Document 2).

JP 2000-347016 A JP 2006-142699 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.

  In addition, the method described in Patent Document 2 requires a facility for irradiating ultraviolet rays in a pattern, so that there is a problem that an excessive cost is required for capital investment and that it takes time to manufacture a sheet.

  This invention is made | formed in view of the subject which the said prior art has, and provides the manufacturing method which can manufacture simply 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 a method for producing an optical film having a liquid crystal layer, the alignment treatment step for imparting liquid crystal alignment ability to the film, and the first on the film subjected to the alignment treatment. A first liquid crystalline composition applying step of applying a first liquid crystalline composition containing a first liquid crystal material having a turning property in a first direction to the region; and the first region of the film subjected to the alignment treatment A second liquid crystal composition applying step for applying a second liquid crystal composition containing a second liquid crystal material having a turning property in a second direction different from the first direction in a second region that does not overlap with the first direction; And a liquid crystal alignment step of forming the liquid crystal layer by fixing the alignment after aligning the first liquid crystal material and the second liquid crystal material.

  In the manufacturing method of the present invention, the liquid crystal material may be a cholesteric liquid crystal. In addition, the helical pitch of the aligned first liquid crystal material and the second liquid crystal material may be equal.

  In the first liquid crystal composition application step and / or the second liquid crystal composition application step of the production method of the present invention, the first liquid crystal composition application step and / or the second liquid crystal composition application step. In the above, the first liquid crystal composition and / or the second liquid crystal composition may be applied in the form of dots. In the first liquid crystal composition application step and / or the second liquid crystal composition application step, the first opening and / or the second region corresponding to the first region and / or the second region may be formed in the film. A mask having two openings is stacked, and the first liquid crystal composition and / or the second liquid crystal composition is applied to a region corresponding to the first opening and / or the second opening of the film. May be.

  The present invention is also an optical film having a liquid crystal layer, wherein the liquid crystal material in a partial region of the liquid crystal layer is the same as the liquid crystal material in another region and the liquid crystal in the partial region in the same plane. Provided is an optical film characterized in that the twist direction of the material is different from the twist direction of the liquid crystal material in the other region.

  In the method for producing an optical film invented by the inventors of the present invention, liquid crystal layers having different rotation directions of the liquid crystal material are formed in some regions and other regions using liquid crystal materials having different twisting (turning) directions. As a result, an optical film in which a pattern is formed by regions having different twist directions of the liquid crystal layer and design properties are imparted is obtained. In particular, by using a liquid crystal material having the same helical pitch but having a different twist (turning) direction, a pattern that cannot be recognized visually but can be recognized through a circularly polarizing plate (hereinafter, such a pattern is referred to as a “latent image” as appropriate). An optical film having the following structure is obtained. And since the area | region from which the twist direction of a liquid crystal layer differs can be formed with arbitrary coating methods, the optical film in which the desired design was formed can be manufactured easily, without damaging a liquid crystal layer. In particular, in this manufacturing method, since no external force is applied after the liquid crystal layer is formed, the substrate is not deformed or the liquid crystal layer is not damaged. Further, since reheating is not performed after the liquid crystal layer is formed, the selective reflection wavelength is not shifted. Furthermore, it is possible to easily carry out at a low cost as compared with the prior art that requires the production of a hologram master or a photomask as described above.

  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.

  ADVANTAGE OF THE INVENTION According to this invention, the optical film excellent in the designability with the simple structure and its manufacturing method are 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 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 10th 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 11th Embodiment of this invention which provided the lenticular lens array on the liquid crystal layer. It is a figure which shows the process which transfers the liquid crystal layer of the optical film in 13th Embodiment of this invention to articles | goods (to-be-transferred object). It is a figure which shows the process of transcribe | transferring the liquid crystal layer of the optical film in 14th Embodiment of this invention to articles | goods (to-be-transferred object).

  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 liquid crystal alignment ability to the alignment film 20 (alignment processing step).

  As shown in FIG. 1C, a first liquid crystal composition containing a first liquid crystal material (for example, right-twisted liquid crystal material) having a turning property in the first direction in the first region 34 on the alignment film 20. Is applied (first liquid crystal composition application step). Next, as shown in FIG. 1D, the second liquid crystal material containing a second liquid crystal material (for example, a left-twisted liquid crystal material) having a turning property in the second direction in the second region 32 on the alignment film 20. A composition is applied (second liquid crystal composition application step). The second region 32 is a region that does not overlap the first region 34, and the second direction is a direction different from the first direction.

  After the first and second liquid crystal materials are aligned by heating, the alignment is fixed and the liquid crystal layer 30 is formed (liquid crystal alignment step). In the obtained liquid crystal layer 30, the turning directions of the liquid crystal material of the liquid crystal layer 30 are different between the first region 34 and the second region 32. Thus, the pattern is formed in the liquid crystal layer 30 by forming the regions 32 and 34 having different twist directions of the liquid crystal material.

  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 above manufacturing method, a pattern can be formed on the liquid crystal layer 30 very easily by applying liquid crystal materials having different twist directions to predetermined regions on the alignment film 20. 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 provided with the anti-counterfeit function and designability can be easily manufactured by the above manufacturing method without damaging the 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, and polycarbonate.

  The alignment film 20 can be formed, for example, by applying an alignment ability to a film obtained by applying a solution obtained by dissolving the constituent materials in a solvent on the substrate 10 and drying it.

  The solvent used when forming the alignment film 20 is appropriately selected according to the material to be used, and examples thereof include 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.

  In the alignment treatment step, the alignment treatment of the alignment film 20 can be performed using a known method, but 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 processing methods, there are methods using an ultraviolet light alignment device, a soft X-ray alignment device, or the like.

  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.

  In the liquid crystal layer 30, a first liquid crystal composition containing a first liquid crystal material is applied to the first region 34 on the alignment film 20, and then a second liquid crystal composition containing a second liquid crystal material is applied to the second region 32. It can be formed by applying and orienting the first and second liquid crystal materials by heating and then fixing the orientation. Examples of the first and second liquid crystal materials include cholesteric liquid crystals, nematic liquid crystals, smectic liquid crystals, and the like, and among these, cholesteric liquid crystals are preferable from the viewpoint of design visibility and latent image formation. 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 crystalline composition mainly composed of a high molecular liquid crystal, a 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 low-molecular liquid crystal include those having a basic skeleton such as a biphenyl derivative, a phenylbenzoate derivative, or a stilbene derivative into which a functional group such as an acryloyl group, a vinyl group, or an epoxy group is introduced. In addition, as the 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.

  The twist direction of the first and second liquid crystal materials can be controlled by the kind of chiral polymer added to the liquid crystalline composition. For example, a right-twisted liquid crystal material can be obtained by adding a polymer containing S-2-methane-1.3-butanediol or isosorbide to the liquid crystalline composition, and R-2-methane-1.3 -A left-twisted liquid crystal material can be obtained by adding a polymer or the like containing butanediol to the liquid crystalline composition. Further, the helical pitch of the first liquid crystal material and the second liquid crystal material may be the same or different.

  In the first and second liquid crystalline composition application steps, the first region 34 and the second region 32 on which the first liquid crystalline composition and the second liquid crystalline composition are applied have no overlapping portion and are separated from each other. preferable. Thereby, mixing of the first liquid crystal composition and the second liquid crystal composition on the alignment film 20 can be prevented. As a method of applying the first liquid crystal composition and the second liquid crystal composition to the first region 34 and the second region 32, any coating method can be used. For example, dots made of the first liquid crystalline composition may be formed in the first region 34 and dots made of the second liquid crystalline composition may be formed in the second region 32 by the ink jet method. Alternatively, a film made of the first liquid crystalline composition may be formed in the first region 34 and a film made of the second liquid crystalline composition may be formed in the second region 32 by screen printing or offset printing. Good. A mask having an opening corresponding to the first region 34 or the second region 32 may be used. As a mask, a film, a sheet, or the like made of any material can be used. For example, a film, a sheet, or the like formed from plastic such as PET, PPS, or OPP, paper, or the like can be used.

  As a method for fixing the cholesteric orientation, a known method can be used. For example, when polymer liquid crystal is used as the first and second liquid crystal materials, after applying the polymer liquid crystal on the alignment film 20, a cholesteric liquid crystal phase is developed by heat treatment or the like, and the cholesteric alignment is rapidly cooled from that state. A method of immobilization can be used. In the case where low molecular liquid crystal is used as the first and second liquid crystal materials, after applying the low molecular liquid crystal on the alignment film 20, a cholesteric liquid crystal phase is expressed by heat treatment or the like, and light is maintained while maintaining the state. A method of immobilizing the cholesteric orientation by crosslinking with heat or an electron beam 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 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, the liquid crystal layer 30 is formed with the regions 32 and 34 having different twist directions of the liquid crystal material. When the liquid crystal layer 30 is composed of cholesteric liquid crystal, the alignment structure of the liquid crystal molecules in each of the regions 32 and 34 has a regular twist so as to draw a spiral in the film thickness direction, and the orientation of the liquid crystal molecules is in-plane It is aligned with. Since the direction of twist of liquid crystal molecules is different between the region 32 and the region 34, the pattern is visually recognized by the difference in the polarization of the reflected light due to the difference in the twist direction when observed through the circularly polarizing plate. When the spiral pitches of the first liquid crystal material and the second liquid crystal material are the same, the pattern becomes a latent image that cannot be seen unless it passes through a circularly polarizing plate. Therefore, the manufactured optical film 100 is used as an anti-counterfeiting element. It can be used suitably. On the other hand, when the spiral pitches of the first liquid crystal material and the second liquid crystal material are different, the wavelengths of light reflected by the first region 34 and the second region 32 are different, so that the design can be visually recognized without passing through the circularly polarizing plate. . Therefore, the manufactured optical film 100 is excellent in design.

  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 formed on the liquid crystal layer 30 can be visually recognized through the adhesive 40. It does not specifically limit and 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 the pattern formed on the liquid crystal layer 30 through the translucent protective film 50 is transparent enough to be visually recognized. 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, the translucent protective film 50 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 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 off the optical film 100 using a solvent can be prevented by using a member having low solvent resistance such as a COP film as 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.

  Different members (hereinafter referred to as back 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 in the first region 34 is composed of a liquid crystal material that reflects green right circularly polarized light, and the liquid crystal layer 30 in the second region 32 is composed of a liquid crystal material that reflects green left 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 30 (strictly, the color viewed by peeling off the adhesive and the translucent protective film) is green, When the back 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 and color of the back member can be seen in the first region 34, and the design and color of the back member can be seen in the second region 32. Absent. On the other hand, when viewed through the right circular polarizing filter, the design and color of the back member cannot be seen in the first region 34, and the design and color of the back member can be seen in the second region 32.

(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 of p · cos θ = λ / n (p is the thickness of the back member and n is the refractive index of the back member). Reflected selectively by diffraction. Therefore, when observing at an angle, a shorter wavelength color is observed. 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 a concavo-convex structure may be laminated as a back member, and a reflective layer may be provided thereon.

(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. 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, new films, seals, labels, and the like having both the effects of the diffractive element and the cholesteric liquid crystal may be mentioned. 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 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. Examples of the label include a fiber label sewn on clothes such as a tie and a 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, the liquid crystal layer in the first region 34 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, and the liquid crystal layer in the second region 32 is left. It is assumed that it is composed of a liquid crystal material that reflects only circularly polarized light. When the optical film 100 is irradiated with natural light having a polarization component in a random direction, only the right circularly polarized light is reflected from the liquid crystal layer in the first region 34 of the optical film 100, and the reflected light is the right circular polarizing filter of the viewer 120. Pass 120a. On the other hand, only the left circularly polarized light is reflected from the liquid crystal layer in the second region 32, and the reflected light cannot pass through the right circularly polarized filter 120 a of the viewer 120. Therefore, the shape of the first region 34, that is, 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 first region 34 liquid crystal layer cannot pass through the left circular polarizing filter 120b, and the left circularly polarized light reflected from the second region 32 liquid crystal layer passes through the left circular polarizing filter 120b. Therefore, when the optical film 100 is viewed through the left circular polarizing filter 120b, a pattern visually recognized through the right circular polarizing filter 120a and a pattern in which brightness and darkness are reversed can be viewed. For the purpose of discrimination only, only a circularly polarizing filter in one of the rotation directions may be used.

  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 twist direction 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 by the difference in the twist direction of the liquid crystal material of the liquid crystal layer. However, in order to further increase the design of the pattern, the liquid crystal layer 30 as in the optical film 102 shown in FIG. A concave / convex pattern 60 for generating a hologram may be provided on the lower surface of the substrate. The concavo-convex pattern 60 is provided so as to cover both the parts (regions) 30a and 30b of the liquid crystal layer 30 in which the liquid crystal material is twisted in different directions. 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 regions 30a and 30b of the liquid crystal layer are composed of cholesteric liquid crystals that reflect right circularly polarized light and left circularly polarized light, respectively, the diffracted light that passes through the region 30a becomes right circularly polarized light, and is diffracted through the region 30b. The light becomes left circularly polarized light. Therefore, when the optical film 102 is observed with the right circular polarizing 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 in the region 30a. I can't observe. Moreover, the pattern formed by the part 30a and the part 30b can be observed thereby. On the other hand, when the optical film 102 is observed with the left circular polarizing filter 120b, a hologram having a color corresponding to a diffraction pattern such as a rainbow color can be observed in the region 30b, but the hologram cannot be observed in the region 30a. The pattern formed by 30a and the part 30b can be observed.

  With this configuration, the design can be increased not only by the difference in the twist direction of the liquid crystal layer 30 but also 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 concavo-convex 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. As in the second embodiment, when the optical film 103 is observed with a right circular polarizing filter, diffracted light having a color corresponding to a rainbow-like diffraction pattern can be observed in the region 30a, but diffracted light is observed in the region 30b. Therefore, the pattern formed by the part 30a and the part 30b can be observed. When the optical film 103 is observed with the left circular polarizing filter, the pattern formed by the portions 30a and 30b can be observed. With this configuration, the design can be increased not only by the twist direction of the liquid crystal layer 30 but also 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 36 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 portions 36a and 36b in which the twist direction of the liquid crystal material of the second liquid crystal layer 36 are different from each other are shifted in the in-layer direction relative to the portions 30a and 30b in which the twist direction of the liquid crystal material of the liquid crystal layer 30 is different from each other. Good. The liquid crystal layer 30 and the second liquid crystal layer 36 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 material that reflects red right circularly polarized light by the front reflection on the portion 30a of the liquid crystal layer 30, the liquid crystal material that reflects red left circularly polarized light by the front reflection on the portion 30b, and the portion 36a of the second liquid crystal layer 36 on the front surface. The liquid crystal material that reflects blue right circularly polarized light by reflection and the portion 36b are made of liquid crystal material that reflects left circularly polarized blue by 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 portions 30a and 30b of the liquid crystal layer 30, the portion 36a looks blue, and only the pattern formed by the portions 36a and 36b of the liquid crystal layer 36 is present. It appears to be raised. On the other hand, when the optical film is observed with a right circular polarizing filter made of the same liquid crystal material as the portions 36a and 36b of the liquid crystal layer 36, the portion 30a looks red, and only the pattern formed by the portions 30a and 30b of the liquid crystal layer 30 is raised. Looks. 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 36, 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 by the difference in the twist direction of the liquid crystal material of the liquid crystal layer. However, in order to further increase the design of the pattern, the liquid crystal layer 30 as in the optical film 105 shown in FIG. A printing layer 82 may be provided on the lower surface of 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 is not polarized or optically rotatory so that it can be visually recognized, so that the portion 30a of the liquid crystal layer 30 of the optical film 105 is formed of a liquid crystal material that reflects right circularly polarized light, If the portion 30b is formed of a liquid crystal material that reflects left circularly polarized light, the logo or design of the printed layer 82 can be observed through the portion 30b when the optical film 105 is observed with the left circularly polarizing filter, and the liquid crystal layer 30 is twisted. The patterns (30a, 30b) formed by the difference are also visible. When the optical film 105 is observed with the right circular polarizing filter, the logo or design of the printed layer 82 can be observed through the portion 30a, and the patterns (30a, 30b) formed on the liquid crystal layer 30 due to the difference in twist direction can also be visually recognized.

  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 due to the difference in the twist direction 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 90 is generated. 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. When the decorative layer 92 is observed with the viewer 120 as shown in FIG. 11, the circularly polarized reflected light from the liquid crystal layer 30 is transmitted and the pattern due to the difference in the twist direction of the liquid crystal material of the liquid crystal layer can be recognized. It is desirable to maintain thickness and 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 concave / convex pattern 60 is provided only on the lower surface of the liquid crystal layer 30 of 108a, and the region 30a having a twist direction different from the surroundings is provided only on the liquid crystal layer 30 of the right half region 108b. Thus, when the liquid crystal layer 30 in the region 30a is composed of a liquid crystal material that reflects right circularly polarized light, and the liquid crystal layer 30 in the other region 30b is composed of a liquid crystal material that reflects left circularly polarized light, as shown in FIG. When the optical film 108 is observed through the left circular polarizing filter 120b as described above, a hologram pattern due to the diffracted light generated from the concavo-convex pattern 60 can be observed from the region 108a, and a pattern generated due to a difference in twist direction from the region 108b. Visible. 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 twist direction different from that of the surroundings is provided only in a part of the liquid crystal layer 30. For example, the region 30a of the liquid crystal layer 30 may be composed of a liquid crystal material that reflects right circularly polarized light, and the region 30b may be composed of a liquid crystal material that reflects left circularly polarized light at the same twist pitch as the region 30a. In this case, when the optical film 109 is viewed from the front, the printed pattern 84a of the printed layer 84 can be seen from the region 109a, but the pattern due to the difference in the twist direction of the liquid crystal cannot be seen from the region 109b. Further, when the optical film 109 is observed through the right circular polarizing filter, a printed pattern is seen from the region 109a, as in the case of viewing, the region 30b is a bright field, the region 30b is a dark field, and the region 30a, You can see the 30b symbol. When the optical film 109 is observed through the left circular polarizing filter, a printed pattern is seen from the region 109a, the region 30b is a dark field, the region 30b is a bright field, and the pattern by the regions 30a and 30b is seen. Note that the print layer 30 and the liquid crystal layer 30 may be the same color, so that the difference between when visually observed and when observed through a right or left circularly polarizing filter is further clarified.

Tenth Embodiment FIG. 11 shows an optical film 112 provided with a microlens array 150 in place 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 to several hundred μm. The pattern formed by the regions 30a and 30b having different twist directions of the liquid crystal layer 30 is a pattern formed by forming a predetermined stereoscopic 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. The microlens array 150 is formed by using acrylic or the like so that birefringence does not occur, so that an image that can be seen only through the right circular polarizing filter or the left circular polarizing filter can be viewed stereoscopically through the viewer. Design can be given to the image.

Eleventh Embodiment FIG. 12 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 area of the liquid crystal layer 30 below each lenticular lens 160a is divided into, for example, areas α, β, and γ as shown in FIG. 12, and the liquid crystal layer 30 is formed in each of the areas α, β, and γ. The pattern which becomes a unit is formed by the regions 30a and 30b having different twist directions of the liquid crystal material to be formed. 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) through the right circularly polarized light or the left circularly polarized light filter, only the pattern by the region α can be observed. . In addition, when the lens array 160 is viewed from the front through the right circularly polarized light or the left circularly polarized filter, only the pattern by the region β can be observed. In addition, when the lenticular lens array 160 is viewed through the right circularly polarized light or the left circularly polarized light filter when the pattern of the region α is viewed from the opposite direction to the normal, the pattern of the region 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 as not to cause birefringence, an image viewed through the right circular polarizing filter or the left circular polarizing filter of the viewer looks different depending on the viewing direction. Can be increased. The symbols recorded in the areas α, β, and γ may be symbols such as a moving image that is continuously connected depending on the viewing direction or a symbol that looks three-dimensional.

Twelfth Embodiment A pattern may be formed on the upper or lower layer of the light-transmissive 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 thirteenth 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. An example of a process for producing an optical film capable of preventing such reuse and transferring the liquid crystal layer of the optical film to an article (transfer object) is shown in FIG.

  The laminate shown in FIG. 13A is a laminate obtained in the liquid crystal alignment 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 a glue 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 composed of 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 (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, the separator is peeled off from the laminate as shown in FIG. Thus, as shown in FIG. 13E, 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. 13C, the laminate can be peeled off after being attached to an object. Here, as described above, the liquid crystal layer can be manufactured as an extremely thin film such as 0.3 to 9 μm, particularly 0.3 to 6.0 μm, so that the breaking strength of the liquid crystal layer is larger than the peeling force of the adhesive layer. 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 FIG. 13, as a separator, olefin resin such as polyethylene, polypropylene, 4-methylpentene-1 resin, polyamide, polyimide, polyamideimide, polyetherimide, polyetherketone, polyetheretherketone, 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 (OPP) triaceti Any material films such as such as 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.

14th Embodiment FIG. 14 shows a modification of the process described in the 13th embodiment. The laminated body shown in FIG. 14A is a laminated body obtained in the liquid crystal alignment 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. 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. 14C, the separator 1 is attached on the adhesive layer. As the separator 1, the same material as the separator used in the thirteenth 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, a separator 2 / glue layer / liquid crystal layer / adhesive layer / separator 1 is formed by attaching a separator 2 via a glue layer as shown in FIG. 14 (e). 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. 14 (g) and attached to the article via the paste of the laminate. Finally, the separator 1 is peeled off with the adhesive remaining, and the form shown in FIG. 14 (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. 14 (h ′), the separator 1 can be peeled together with the adhesive so that only the liquid crystal layer remains on the article through 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. 14 (h)) or not (FIG. 14 (h ′)) is a 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 the separator 1, separator 2, glue, and adhesive used in the optical films of the thirteenth and fourteenth 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.

  FIGS. 13 and 14 show an example using an alignment film as in the first embodiment, but the alignment film is omitted when a substrate capable of providing orientation to the substrate itself is used. can do.

  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.

  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 embodiment, the pattern or design is formed by the regions 30a and 30b in which the twist directions of the liquid crystal material of the liquid crystal layer are different from each other, but the dot pattern, barcode pattern, QR code (registered) is used for 30a or the 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 ... Substrate, 20 ... Alignment film, 30 ... Liquid crystal layer, 40 ... Adhesive, 50 ... Translucent protective film, 60 ... Uneven pattern, 70 ... Rubbing roll, 72 ... Reflective layer, 82, 84 ... Print layer, 90 ... Light absorbing layer, 92 ... Decorative layer, 100, 102 to 109 ... Optical film, 120 ... Viewer, 130 ... Support

Claims (18)

A method for producing an optical film having a liquid crystal layer,
An alignment treatment step for imparting liquid crystal alignment ability to the film;
A first liquid crystal composition application step of applying a first liquid crystal composition containing a first liquid crystal material having a turning property in a first direction to the first region on the film subjected to the alignment treatment;
A second liquid crystalline composition containing a second liquid crystal material having a second liquid crystal material having a turning property in a second direction different from the first direction is applied to a second region that does not overlap the first region of the film subjected to the alignment treatment. A second liquid crystalline composition coating step,
A method for producing an optical film, comprising: aligning the first liquid crystal material and the second liquid crystal material by heating and then fixing the alignment to form the liquid crystal layer.   The method for producing an optical film according to claim 1, wherein the helical pitches of the aligned first liquid crystal material and the second liquid crystal material are equal.   The first liquid crystal composition and / or the second liquid crystal composition are applied in the form of dots in the first liquid crystal composition application step and / or the second liquid crystal composition application step. The manufacturing method of the optical film of 2.   In the first liquid crystal composition application step and / or the second liquid crystal composition application step, a first opening and / or a second opening corresponding to the first region and / or the second region in the film. A mask having a portion is overlapped, and the first liquid crystalline composition and / or the second liquid crystalline composition is applied to a region corresponding to the first opening and / or the second opening of the film. The manufacturing method of the optical film of 1 or 2.   The method for producing an optical film according to claim 1, wherein the liquid crystal material is cholesteric liquid crystal. An optical film having a liquid crystal layer,
An optical film, wherein the liquid crystal material in a part of the liquid crystal layer has a different turning direction from the liquid crystal material in another area.   The optical film according to claim 6, wherein the helical pitch of the liquid crystal material in a part of the liquid crystal layer is equal to that of the liquid crystal material in the other area.   8. The optical film according to claim 6, 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 6-8 characterized by the above-mentioned.   The optical film according to any one of claims 6 to 8, 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 10, 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 10 or 11, wherein the separator is peeled off from the adhesive layer, and the liquid crystal layer is attached to an article via the adhesive layer.   Furthermore, a back surface member is provided, The optical film as described in any one of Claims 6-12 characterized by the above-mentioned.   Furthermore, a microlens array is provided, The optical film as described in any one of Claims 6-13 characterized by the above-mentioned.   Furthermore, a lenticular lens array is provided, The optical film as described in any one of Claims 6-13 characterized by the above-mentioned.   The optical film according to any one of claims 6 to 15, wherein a region exhibiting diffractive power is formed in the liquid crystal layer.   Furthermore, the layer which shows a diffraction ability is provided, The optical film as described in any one of Claims 6-16 characterized by the above-mentioned. An article provided with the optical film according to any one of claims 6 to 17.

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