TW201723601A - Optical film - Google Patents

Abstract

This optical film 100 has a protective film 50 and a liquid crystal layer 30. A region 30a that is a part of the liquid crystal layer 30 has the same liquid crystal material as another region 30b, but the region 30a has a different alignment state from the other region 30b. An uneven pattern 60 having diffractive properties may be provided on the lower surface of the liquid crystal layer 30. Thus, it is possible to easily manufacture an optical film having an excellent design without causing damage to the liquid crystal layer.

Description

Optical film

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

As the film imparting design properties, an optical film in which a hologram is formed is known. Such an optical film is produced, for example, by transferring a heated hologram original to a cholesteric liquid crystal film formed on an alignment film, and transferring a hologram (a diffraction grating or the like) (for example, refer to Patent Document 1) ).

Further, as an optical film in which a plurality of regions having different reflection wavelengths are provided on the cholesteric liquid crystal layer, a sheet having an anti-counterfeiting function is also known. Such a sheet is produced, for example, by a method of irradiating ultraviolet rays to the cholesteric liquid crystal layer in a pattern by a mask provided with a slit in a pattern.

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2000-347016

However, in the method described in Patent Document 1, it is necessary to press the heated hologram master to the liquid crystal film, and since the pressure is applied to the substrate or the liquid crystal layer itself in a heated state, there is a problem that the substrate is generated. Deformation or damage to the liquid crystal layer, or from the choice of design Selecting the reflection wavelength produces an offset or the like.

The present invention has been made in view of the problems of the prior art described above, and an object of the invention is to provide an optical film which can easily produce a design-imparting optical film without causing damage to the liquid crystal layer. Further, 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 in which a liquid crystal material of a portion of the liquid crystal layer is the same as a liquid crystal material of other regions, and a liquid crystal material of the partial region and a liquid crystal material of the other regions. The alignment status is different.

According to the method for producing an optical film invented by the inventors of the present invention, the alignment ability of a portion of the alignment film is eliminated or attenuated by surface treatment, whereby the liquid crystal layer formed thereon is capable of eliminating or weakening the alignment ability. The liquid crystal material on the alignment film is not aligned, but forms an area in which the alignment state is different from other regions. As a result, it is possible to obtain an optical film in which a pattern is formed by a region in which the alignment state of the liquid crystal layer is different, thereby imparting design properties. Further, since the region in which the alignment state of the liquid crystal layer is different can be formed by the surface treatment of the alignment film, the optical film having the desired pattern can be easily produced without causing damage to the liquid crystal layer. In particular, in the case of surface treatment of the alignment film, no external force is applied after the liquid crystal layer is formed, so that deformation of the substrate or damage to the liquid crystal layer does not occur. Further, since the reheating is not performed after the liquid crystal layer is formed, the shift of the selective reflection wavelength does not occur. Further, as a surface treatment method of the alignment film, a method of applying a solvent to a partial region of the alignment film, directly drawing with CO ₂ laser light, using a masked excimer UV irradiation, and an electron may be mentioned. Bundle (EB, electron beam) depiction. Further, a method of imparting an alignment ability by the friction of the mask described below 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 be "irregularly aligned". In the optical film of the present invention, the liquid crystal layer may also be obtained by using a liquid crystal material A continuous film formed by coating 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 comprise a protective film.

The optical film of the present invention may be provided with a release sheet which can be peeled off on the surface of the liquid crystal layer via a paste layer. Further, on the surface of the liquid crystal layer opposite to the paste layer, another spacer which can be peeled off may be provided via 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 be formed with a region exhibiting a diffraction ability in the liquid crystal layer, or may further have a layer exhibiting a diffraction ability. The optical film of the present invention may further comprise a printed layer on the lower layer of the liquid crystal layer.

According to the present invention, an optical film excellent in design can be obtained by a simple configuration.

10‧‧‧Substrate

20‧‧‧Alignment film

22‧‧‧Part of the area (solvent coating department)

30‧‧‧Liquid layer

32‧‧‧ patterns

40‧‧‧Binder

50‧‧‧Transparent protective film

60‧‧‧ concave pattern

70‧‧‧ friction roller

72‧‧‧reflective layer

80‧‧‧ impression

82, 84‧‧‧Printing layer

90‧‧‧Light absorbing layer

92‧‧‧Decorative layer

94‧‧‧Intermediate

100, 102~110‧‧‧ optical film

120‧‧‧Viewer

120a‧‧‧Right circular polarizing filter

120b‧‧‧left circular polarizing filter

130‧‧‧Support

150‧‧‧Microlens array

160‧‧‧ convex mirror lens array

1(a) to 1(f) are explanatory views for explaining an embodiment of a method for producing an optical film of the present invention.

Fig. 2 is a schematic cross-sectional view showing an optical film according to a second embodiment of the present invention.

Fig. 3 is a schematic cross-sectional view showing an optical film according to a third embodiment of the present invention.

Fig. 4 is a schematic cross-sectional view showing an optical film according to a fourth embodiment of the present invention.

Fig. 5 is a schematic cross-sectional view showing an optical film according to a fifth embodiment of the present invention.

Fig. 6 is a schematic cross-sectional view showing an optical film according to a sixth embodiment of the present invention.

Fig. 7 is a schematic cross-sectional view showing an optical film according to a seventh embodiment of the present invention.

Fig. 8 is a schematic cross-sectional view showing an optical film according to an eighth embodiment of the present invention.

Fig. 9 is a schematic cross-sectional view showing an optical film according to a ninth embodiment of the present invention.

Fig. 10 is a schematic cross-sectional view showing an optical film according to a tenth embodiment of the present invention.

Fig. 11 is an explanatory view showing a state in which the optical film is observed to be authentic using a viewer.

Fig. 12 is a schematic cross-sectional view showing an optical film according to an eleventh embodiment of the present invention in which a microlens array is provided on a liquid crystal layer.

Fig. 13 is a schematic cross-sectional view showing an optical film according to a twelfth embodiment of the present invention in which a convex lens-shaped lens array is provided on a liquid crystal layer.

Figs. 14(a) to 14(e) are views showing a process of transferring a liquid crystal layer of an optical film according to a fourteenth embodiment of the present invention to an article (a material to be transferred).

Figs. 15(a) to 15(h) and (h') are views showing a process of transferring a liquid crystal layer of an optical film according to a fifteenth embodiment of the present invention to an article (a material to be transferred).

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

First embodiment

A first embodiment of the optical film of the present invention will be described with reference to Figs. 1(a) to 1(f). 1(a) to 1(f) are explanatory views for explaining a method of manufacturing an optical film of the embodiment.

First, as shown in FIG. 1(a), an alignment film 20 is formed on the substrate 10. As shown in FIG. 1(b), the surface of the alignment film 20 is rubbed with a rubbing roller 70 to impart an alignment ability to the alignment film 20.

Then, a surface treatment for eliminating or weakening the alignment ability of a partial region 22 of the alignment film 20 is performed. For example, as shown in Fig. 1(c), a solvent is attached to an impression (solvent application means) 80, and is pressed against a partial region (solvent coating portion) 22 on the alignment film 20 to which the alignment ability has been imparted. This applies a solvent to the region 22 to eliminate the alignment ability of the region 22 (solvent coating step).

As shown in Fig. 1(d), a liquid crystal composition containing a liquid crystal material is applied onto the alignment film 20, and the liquid crystal material is aligned by heating, and then the alignment is fixed to form a liquid crystal layer 30 (liquid crystal layer forming step). At this time, since the alignment ability of a partial region 22 of the alignment film 20 disappears, the liquid crystal material is not regularly aligned in the region of the liquid crystal layer 30 located on the region 22, and the alignment state of the liquid crystal material is different from other regions, so the liquid crystal is A pattern 32 is formed on layer 30. The pattern 32 corresponds to the pattern formed on the stamp 80.

As shown in FIG. 1(e), the light-transmitting protective film 50 is adhered to the liquid crystal layer 30 via the 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, and the optical film 100 composed of the liquid crystal layer 30/adhesive 40/translucent protective film 50 is obtained.

According to the above production method, the pattern 32 can be formed extremely easily on the liquid crystal layer 30 by applying the solvent to the alignment film 20 only by a solvent coating means such as the stamper 80. Further, after the formation of the liquid crystal layer 30, it is not necessary to apply an excessive force to "press the heated hologram master or the like to form a pattern", so that the liquid crystal layer 30 is not damaged. Thus, according to the above-described production method, the optical film imparting design properties can be easily produced without causing damage to the liquid crystal layer. Hereinafter, each material and each step used in the above production method will be described in more detail.

The substrate 10 functions as a support for the alignment film 20 and the liquid crystal layer 30 After the light-transmitting protective film 50 is formed on the liquid crystal layer 30, the substrate 10 and the alignment film 20 are peeled off together. Examples of the support substrate having such a function include polyimine, polyamidimide, polyamine, polyether oxime, polyether ether ketone, polyether ketone, and polyketide ( Polyketone sulfide), polyether oxime, polyfluorene, polyphenylene sulfide, polyphenylene ether, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyacetal , polycarbonate, polyarylate, acrylic resin, epoxy resin, phenol resin, polyvinyl alcohol, cellulose-based plastic, or polyethylene, polypropylene, poly(4-methyl-1-pentene), hail A plastic film or sheet formed of a chain or alicyclic polyolefin such as an olefin resin.

Further, as the substrate 10, a surface treatment such as a ruthenium treatment on the surface of a plastic film or a sheet, or a wax coated with an acrylic resin, a methacrylic resin, an epoxy resin or a paraffin wax may be used. Further, as the substrate 10, a plastic film or a sheet may be subjected to physical deformation treatment such as embossing, hydrophilization treatment, or hydrophobizing treatment.

The thickness of the substrate 10 is usually 8 to 200 μm, preferably 15 to 150 μm, more preferably 20 to 100 μm. When the thickness is thinner than 8 μm, there is a tendency that the workability is lowered at the time of production of the optical film. Moreover, when the thickness is 200 μm thick, the workability is lowered when the substrate 10 and the alignment film 20 are peeled off from the liquid crystal layer 30.

The alignment film 20 is a layer having a function of aligning a liquid crystal material. Further, 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 a constituent material of the alignment film in a solvent onto the substrate 10, and drying the film to form a film. Thereafter, a rubbing treatment is performed to impart an alignment ability.

The solvent to be used in forming the alignment film 20 can be appropriately selected depending on the material to be used, and examples thereof include acetone, cyclohexanone, toluene, methyl ethyl ketone, ethyl acetate, water, ethanol, and isopropyl alcohol. Further, it is preferred that the solvent used in forming the alignment film 20 does not dissolve the substrate 10. Therefore, it is preferable that the constituent material of the alignment film 20 and the constituent material of the substrate 10 are materials in which the solvents to be dissolved are different from each other.

Drying is carried out by performing heat treatment under the conditions corresponding to the solvent to be used. The drying conditions may be appropriately adjusted depending on the type of the solvent to be used, the film thickness, and the like, and are usually 30 to 200 ° C for 20 to 60 seconds.

The thickness of the alignment film 20 is usually 0.3 to 6 μm, preferably 0.6 to 2 μm, more preferably 0.8 to 1.4 μm. When the thickness is thinner than 0.3 μm, there is a tendency that it is easily affected by defects such as fine flaws of the substrate 10, and when the thickness is 3 μm thick, drying unevenness tends to occur.

The alignment treatment of the alignment film 20 can be carried out by a known method, and if it is roughly classified, the alignment is performed by a rubbing treatment, and the alignment is performed by a method other than the above. As the rubbing treatment, there is a method of using the rubbing roller 70 as shown in Fig. 1(b). As the other alignment treatment method, there are a method of performing alignment by stretching, a method of aligning by imprint, a method of aligning using an ultraviolet alignment device, a soft X-ray alignment device, or the like.

The solvent to be used in the solvent application step is not particularly limited as long as the alignment ability of the alignment film 20 can be eliminated, and a solvent capable of dissolving the constituent material of the alignment film 20 is usually used. The solvent used in the solvent coating step may be the same as the solvent used in forming the alignment film 20, or may be used differently, or a plurality of solvents may be used in combination.

The solvent coating method is not particularly limited as long as it can apply a solvent to the alignment film 20, and in addition to the method of using the stamp 80 shown in Fig. 1(c), a sprayer can be used. Spray, printing by inkjet printer, gravure printing, letterpress printing, and the like.

The amount of the solvent to be applied may be any amount as long as the alignment ability of the partial region 22 of the alignment film 20 is eliminated, and can be 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 the solvent to be used and the like, and are usually room temperature and 10 to 30 seconds.

The liquid crystal layer 30 can be formed by applying a liquid crystal composition containing a liquid crystal material to the alignment film 20, and after aligning the liquid crystal material by heating, the alignment is fixed. Examples of the liquid crystal material include a cholesteric liquid crystal, a nematic liquid crystal, and a smectic liquid crystal. Among them, the cholesteric liquid crystal is preferable from the viewpoint of 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 by using a liquid crystalline composition containing a polymer liquid crystal, a crosslinked low molecular liquid crystal, or a mixture thereof as a main component.

The polymer liquid crystal is not particularly limited as long as it can be immobilized by cholesteric alignment, and any of a main chain type and a side chain type polymer liquid crystal can be used. Specific examples thereof include main chain type liquid crystal polymers such as polyester, polyamide, polycarbonate, and polyester phthalimide; and polyacrylate, polymethacrylate, polymalonate, and polyoxyl A side chain type liquid crystal polymer such as an alkane. Among these, a liquid crystalline polyester which forms a cholesteric alignment and has an excellent alignment property and is easy to synthesize is preferable. Examples of the constituent unit of the polymer include aromatic or aliphatic diol units. A preferred example of the aromatic or aliphatic dicarboxylic acid unit, aromatic or aliphatic hydroxycarboxylic acid unit.

In addition, examples of the cross-linking type low molecular liquid crystal include a biphenyl derivative having a functional group such as an acryl fluorenyl group, a vinyl group or an epoxy group, a phenyl benzoate derivative, and a stilbene derivative. Basic skeleton. Further, as the cross-linking type low molecular liquid crystal, any of a cross-linking type low molecular liquid crystal exhibiting lyotropic and a cross-linking type low molecular liquid crystal exhibiting thermotropic can be used, but the display is thermally induced. The cross-linking type low molecular liquid crystal is more preferable from the viewpoint of workability and the like.

A well-known method can be used for the method of immobilizing a cholesteric type alignment. For example, when a polymer liquid crystal is used as a liquid crystal material, a method in which a polymer liquid crystal is applied onto the alignment film 20 and then a cholesteric liquid crystal phase is formed by heat treatment or the like, from this state Quenching causes the cholesteric alignment to be immobilized. In the case where a crosslinked low molecular liquid crystal is used as the liquid crystal material, the following method or the like can be suitably employed, that is, after the crosslinked low molecular liquid crystal is applied onto the alignment film 20, it is subjected to heat treatment or the like. The cholesteric liquid crystal phase is visualized, and the cholesteric alignment is fixed by crosslinking the liquid crystal by light, heat, electron beam or the like while maintaining the state.

In addition, in order to improve the heat resistance of the cholesteric liquid crystal layer, a liquid crystal composition may be added with, for example, a bisazide compound or methacrylic acid in addition to a polymer liquid crystal or a crosslinked low molecular liquid crystal. A crosslinking agent such as glycidyl ester. By adding these crosslinking agents, it is possible to crosslink in a state in which a cholesteric liquid crystal phase is visualized. Further, various additives such as a dichroic dye, a dye, and a pigment may be appropriately added to the liquid crystal composition.

The liquid crystal layer 30 is usually composed of a single liquid crystal layer such as the above-described cholesteric liquid crystal layer, but may be formed 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. More preferably 0.7 to 3 μm. When the thickness is less than 0.3 μm, there is a concern that the effect of the specific optical characteristics cannot be effectively exhibited. When the thickness exceeds 20 μm, drying unevenness tends to occur. In the case where the liquid crystal layer 30 is formed by laminating a plurality of liquid crystal layers, it is preferable that the total thickness of all the liquid crystal layers is in the above range.

As described above, in the liquid crystal layer 30, in the region on the portion 22 where the alignment ability of the alignment film 20 disappears, a portion in which the alignment state of the liquid crystal material is different from the other regions is formed. When the liquid crystal layer 30 is composed of a cholesteric liquid crystal, the alignment structure of the liquid crystal molecules has a regular twist in such a manner that the spiral is drawn in the film thickness direction, and the liquid crystal molecules are aligned in the same plane. On the other hand, the liquid crystal molecules on the region where the alignment ability disappears are inconsistent and random in the same plane, and the pattern 32 differs depending on the manner in which the reflected light is visually reflected.

The light-transmitting protective film 50 is adhered to the liquid crystal layer 30 via the adhesive 40. The adhesive 40 is not transparent to the liquid crystal layer 30 and the light-transmitting protective film 50, and is transparent to the pattern 32 of the liquid crystal layer 30 by the adhesive 40. Particularly, various adhesives and adhesives previously known can be used. Specifically, a hot melt adhesive, a photocurable or electron beam curable reactive adhesive, or the like can be suitably used. Among these, a reactive adhesive is preferred from the viewpoint of workability and the like.

The hot-melt type adhesive is not particularly limited, but from the viewpoint of workability and the like, the hot-melt working temperature is preferably 250 ° C or lower, preferably 80 to 200 ° C, more preferably about 100 to 160 ° C. Specific examples of the hot-melt type adhesive include an ethylene-vinyl acetate copolymer resin, a polyester resin, a polyurethane resin, a polyamide resin, a thermoplastic rubber, and a polyacryl resin. Polyvinyl acetal resin such as polyvinyl alcohol resin or polyvinyl butyral, petroleum resin, terpene resin, rosin resin, etc. as matrix resin Hot melt adhesive.

As the reactive adhesive, other monofunctional or polyfunctional monomers, various polymers, stabilizers, photopolymerization initiators, sensitizers, and the like may be blended to have photopolymerization or electron beam polymerizability as needed. Used as a prepolymer and/or a monomer.

Specific examples of the prepolymer having photopolymerization or electron beam polymerizability include polyester acrylate, polyester methacrylate, polyurethane acrylate, polyurethane methacrylate, epoxy acrylate, and epoxy resin. A acrylate, a polyol acrylate, a polyol methacrylate or the like. Further, examples of the monomer having photopolymerization or electron beam polymerizability include a monofunctional acrylate, a monofunctional methacrylate, a bifunctional acrylate, a bifunctional methacrylate, and a trifunctional or higher polyfunctional acrylate. , polyfunctional methacrylate, and the like. In addition, commercially available products such as Aronix (acrylic special monomer, oligomer; East Asia Synthetic (stock)), Lightester (manufactured by Kyoeisha Chemical Co., Ltd.), and Viscoat (Osaka Organic Chemical Industry) can also be used. (Shares) manufacturing, etc. may also be used in the present invention.

Further, as the photopolymerization initiator, for example, benzophenone derivatives, acetophenone derivatives, benzoin derivatives, and 9-oxosulfuric acid can be used. Class, Michelin, benzoin derivatives, three Derivatives, fluorenylphosphine oxides, and azo compounds.

The viscosity of the photocurable or electron beam curing type reactive adhesive which can be used in the present invention is appropriately selected depending on the processing temperature of the adhesive, etc., although it is not generalized, but it is usually 10 to 2000 mPa at 25 ° C. s, preferably 50~1000mPa. s, more preferably 100~500mPa. s. The viscosity is below 10mPa. In the case of s, it is difficult to obtain the desired thickness. Also, above 2000mPa. In the case of s, there is a decrease in workability, which is less desirable. In the case where the viscosity deviates from the above range, it is preferred to appropriately adjust the solvent or monomer ratio to have a desired viscosity.

Further, in the case of using a photocurable reactive adhesive, as a curing method of the adhesive, a known hardening means such as a low pressure mercury lamp, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a metal halide lamp, a xenon lamp, or the like can be used. . Further, the amount of exposure varies depending on the type of the reactive adhesive to be used, and therefore it is not uniform, but is usually 50 to 2000 mJ/cm ² , preferably 100 to 1000 mJ/cm ² .

Further, in the case of using an electron beam-curing type reactive adhesive, the curing method of the adhesive is appropriately selected depending on the transmission force or the curing force of the electron beam, and it is not generally possible, but generally it is possible to accelerate the voltage. It is hardened by irradiation under conditions of 50 to 1000 kV, preferably 100 to 500 kV.

The thickness of the adhesive 40 is not particularly limited, but is usually 0.5 to 50 μm, preferably 1 to 10 μm. Further, as a method of forming the adhesive 40, for example, a roll coating method, a die coating method, a bar coating method, a curtain coating method, an extrusion coating method, or a gravure roll coating method can be used. A known method such as a spray coating method or a spin coating method.

The translucent protective film 50 is not particularly limited as long as it is transparent to the pattern 32 formed on the liquid crystal layer 30 by the translucent protective film 50, and examples thereof include triethyl hydrazine. Cellulose (TAC), polymethyl methacrylate, polystyrene, polycarbonate, polyether oxime, polyphenylene sulfide, amorphous polyolefin, polyethylene terephthalate, polyethylene naphthalate A film formed of an ester, a cycloolefin polymer (COP), polyvinyl alcohol or the like. The light transmissive protective film 50 may also contain an ultraviolet absorber. Further, the light transmissive protective film 50 may be a hard coat layer. Further, in the case of being used as a hard coat layer, beads or metal powder (flashing agent) may be contained in order to improve design. Further, for the purpose of adding anti-reflection, an anti-reflection film may be used as the protective film, or an anti-reflection layer may be formed on the protective film.

The thickness of the light-transmitting protective film 50 is not particularly limited, but is usually 8 to 200 μm, preferably 20 to 100 μm.

The method of peeling the alignment film 20 and the substrate 10 from the liquid crystal layer 30 is not particularly limited, and for example, it can be carried out by attaching an adhesive tape to the corner or end of the alignment film 20 or the substrate 10 and manually peeling it off. a method of mechanically peeling off using a roll or the like; a method of mechanically peeling after being immersed in a poor solvent with respect to all the structural materials; a method of applying ultrasonic waves in a poor solvent; and using the alignment film 20 or the substrate 10 and the liquid crystal A method in which a temperature change is caused by a difference in thermal expansion coefficient of the layer 30 to cause peeling.

The method for producing an optical film of the present invention has been described. The optical film of the present invention is such that the liquid crystal material of a portion of the liquid crystal layer is the same as the liquid crystal material of other regions, and the liquid crystal material of the partial region is aligned with the liquid crystal material of the other regions. The state is different, but the optical film of the present invention can also be produced by other manufacturing methods. For example, as shown in FIG. 1(a), the alignment film 20 is formed on the substrate 10. Next, in order to impart an alignment capability to only a predetermined region, a mask having an opening in a predetermined region is provided on the alignment film. Then, similarly to the above embodiment, the rubbing treatment was performed using a rubbing roller from above the mask. Thereby, the alignment ability can be imparted only to the alignment film exposed in a predetermined region of the opening of the mask. Then, in the same manner as in the above embodiment, the liquid crystal composition containing the liquid crystal material is applied onto the alignment film, and the liquid crystal material is aligned by heating, and then the alignment is fixed to form a liquid crystal layer. At this time, since there is no alignment ability in a region other than the predetermined region of the alignment film, the liquid crystal material is not regularly aligned in the region of the liquid crystal layer located in the region, and the alignment state of the liquid crystal material is different from the predetermined region, so the liquid crystal is The layers form a pattern. Finally, the light-transmitting protective film is adhered to the liquid crystal layer via an adhesive in the same manner as in the above embodiment, and the alignment film and the substrate are peeled off from the liquid crystal layer, whereby a liquid crystal layer/adhesive/transparent can be obtained. Sex An optical film composed of a protective film.

Further, the liquid crystal can be formed in the same manner by direct drawing using CO ₂ laser light, or by using a masked excimer UV irradiation or electron beam (EB) drawing method for the surface treatment of the alignment film. The area of the layer with different alignment states.

The optical film 100 composed of the liquid crystal layer 30 / the adhesive 40 / the light-transmitting protective film 50 can be used for anti-counterfeiting, decoration, and the like. The optical film 100 can be applied by applying an adhesive or the like to the side of the liquid crystal layer 30 and attaching it to an identification plate, a label, a cosmetic case, a packaging material, a packaging material, or the like. There may also be patterns on these. Further, as described in detail in the following embodiments, the optical film 100 can be applied to an adhesive layer such as a hot melt or an electromagnetic wave curable resin on the side of the liquid crystal layer 30, and then the back layer side is brought into contact with an article such as a sign, and is self-transparent. The side of the protective film 50 is subjected to hot stamping or electromagnetic wave irradiation to be followed by an article such as a sign. In addition, by using a member having a low solvent resistance such as a COP film for the light-transmitting protective film 50, it is possible to prevent reuse of the film by using a solvent. A water-soluble film or the like can also be used for the same purpose. Further, the adhesive 40 and the light-transmitting protective film 50 may be peeled off and used as a transfer foil.

Further, different members (hereinafter referred to as back members) may be formed or adhered to various surfaces on the liquid crystal layer 30 side of the optical film 100, that is, on the back side of the liquid crystal layer 30. Specific examples of the back member will be exemplified below.

(1) colored back member

Change the color of the "back surface member" (label, label, etc.) attached to the side of the liquid crystal layer 30 or the pattern provided on the side to black (green), white (red), blue (blue), etc. The color makes the visual color different. For example, the liquid crystal layer 30 is constituted by a liquid crystal material that reflects the right circular polarization of green light. In this case, when the color of the back member is black, it is visually viewed from the front side of the liquid crystal layer. The color of the time (strictly, the color of the adhesive and the light-transmitting protective film is peeled off and visually observed) is green, but when the back member is white, it appears to be a complementary color red. Moreover, when the back member is set to blue, it looks blue. Therefore, although it is a monochromatic optical film, the color of RGB can be expressed by changing the color of the back member. When the optical film having such a back surface member was observed by the left circular polarization filter of the viewer described below, the pattern of the liquid crystal layer disappeared, and only the pattern and color of the back surface member were visible.

(2) a back member having a sloping concave and convex structure

The back member may also have an inclined concavo-convex structure on its surface. The concavo-convex structure is a size of nanometers to millimeters, and can be formed by a known method such as nanoimprinting or embossing. When the incident light has an incident angle θ, it satisfies p. The light of the wavelength λ of the Bragg reflection condition (p is the thickness of the back member, n is the refractive index of the back member) of cos θ = λ / n is selectively reflected by diffraction. Therefore, a shorter wavelength color can be observed when viewed from an angle. The light of the wavelength λ diffracted in the front direction penetrates the spiral structure of the liquid crystal by the unevenness of the slope of the back surface. Therefore, even when viewed from the front side, the same effect as the observation of the angle can be obtained, and multicolor can be expressed. The coloring can be achieved by adjusting the tilt angle, so that the design is improved.

(3) as a back member of the phase difference member

A retardation film formed of a liquid crystal layer (nematic liquid crystal) or a concavo-convex structure may be laminated as a back surface member, and a reflective layer may be provided thereon. By providing the reflective layer and returning the circularly polarized light of the reverse twist of the transmission, the pattern of the cholesteric layer does not disappear due to the circular polarizing plate (and the linear polarizing plate). On the other hand, the retardation film is transparent when observed by the naked eye, but is colored and recognizable by observation by a linear polarizing plate. Moreover, the lower side of the cholesteric liquid crystal is disposed In the case of the retardation film, the unaligned portion of the cholesteric liquid crystal can recognize the retardation film portion in the state without the polarizing plate.

(4) as a back member of the mirror member

A back member composed of a transparent member (glass, film)/reflecting portion can also be used. The reflecting portion may be formed over the entire surface or may be partially formed. If the reflection portion is provided, the pattern does not disappear in the viewer using the circular polarization filter. Patterns or characters can be drawn on the backing paper by using a higher reflectivity such as aluminum foil. Alternatively, the pattern may be drawn on the aluminum foil, for example with black ink. If the right circular polarizing filter of the viewer is used, only the characters drawn on the aluminum foil disappear. When the transparent member is thick, when viewed from an angle, the reflected image on the surface of the transparent member and the reflected image on the reflective portion are offset. If visually, the pattern protrusion of the cholesteric liquid crystal layer can be seen ( Suspected 3D pattern). Thereby, the design is improved. The various back members described above may be formed of, for example, a material such as PET, COP, or TAC.

The optical film of the present invention is extremely versatile and can be used as various optical elements, optoelectronic device elements, decorative members, anti-counterfeiting elements, and the like. In particular, it can be used as a new film, a seal, a sign, etc., which have the effects of each of a diffractive element and a cholesteric liquid crystal. For example, it can be attached to or embedded in a support substrate such as a car driver's license, an identity card, a passport, a credit card, a prepaid card, various exchange vouchers, a gift card, a securities such as a card substrate, and a liner. Further, as a sealing member, it can be attached to a battery, a camera, a computer, a clock, or the like. As the identification plate, for example, it can be used as a fiber identification plate sewn on clothes such as a tie or a shirt.

Particularly in the case of use as an element for anti-counterfeiting, in order to confirm that the optical film or the transfer material transferred therefrom is authentic, the viewer 120 as shown in Fig. 11 is generally used. In the two opening portions of the viewer 120, a right circular polarizing filter 120a that only passes the right circularly polarized light is attached, and only the left is left. The circularly polarized light passes through the left circular polarizing filter 120b. Here, the liquid crystal layer of the optical film 100 of the embodiment mounted on the support 130 such as a card is formed of a liquid crystal material that reflects only the right circularly polarized light. When the optical film 100 is irradiated with natural light having a polarization component in a random direction, only the right circular polarization is reflected from the liquid crystal layer of the optical film 100, and the reflected light passes through the right circular polarization filter 120a of the viewer 120, so that The right circular polarizing filter 120a sees the pattern or design attached to the liquid crystal layer. 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 pattern or design attached to the liquid crystal layer cannot be seen. For the purpose of discriminating only, a circularly polarizing filter that cannot see the direction of rotation of the design can be used.

[Examples]

Hereinafter, the examples of the optical film of the first embodiment will be more specifically described, 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 an alignment ability and doubles as an alignment film. The stamp to which toluene was attached was pressed against the PET film at a pressure of 10 kPa for 0.2 second, and then dried at room temperature for 15 seconds.

19.0% by weight of a nematic liquid crystal (manufactured by PALIOCOLOR LC242 BASF), a chiral agent (manufactured by PALIOCOLOR LC756 BASF), 1.0% by weight of a fluorenylphosphine oxide-based photopolymerization initiator (IRGACURE TPO BASF) a solution of 0.8% by weight and 79.2% by mass of cyclohexanone was applied to a PET film so as to have a thickness of 1.6 μm after drying, and dried in a drying oven at 55 ° C for 15 minutes to dry it. . Then, it was placed in a heat treatment furnace heated to 100 ° C for 10 minutes, and placed in a heat treatment furnace heated to 80 ° C for 10 minutes to align the liquid crystal, and the alignment was fixed by light irradiation by an LED-UV lamp. A cholesteric liquid crystal layer.

On the liquid crystal layer, a PC (polycarbonate) film is attached via an ultraviolet curable adhesive (manufactured by Toagosei Co., Ltd., trade name: ARONIXUV-3630), and a light is irradiated by a high pressure mercury lamp to form an adhesive. hardening. Thereafter, the PET film was peeled off from the liquid crystal layer to obtain an optical film composed of a liquid crystal layer/adhesive/PC film.

(Example 2)

A solution composed of 4% by mass of PVA (polyvinyl alcohol), 76.8 mass% of pure water, and 19.2% by mass of IPA (isopropyl alcohol) was applied to PEN (polynaphthalene) so that the thickness after drying became 1.2 μm. The ethylene glycol formate film was dried from 40 ° C to 130 ° C in a drying oven at a high temperature for 36 seconds to form a PVA film. A low-density polyethylene film having a thickness of 30 μm cut into a character shape was attached to the PVA film, and rubbing treatment was performed using a rubbing roll to which a rubbing cloth was attached to form an alignment film.

A cholesteric liquid crystal layer was formed on the alignment film in the same manner as in Example 1. Further, a TAC film was attached to the liquid crystal layer in the same manner as in Example 1 except that a TAC (triethyl fluorene cellulose) film was used instead of the PC film. Thereafter, the alignment film and the PEN film were peeled off 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 subjected to rubbing treatment without using a polyethylene film cut into a character shape.

A solvent to which a mixed solvent of water and ethanol (water: ethanol = 2:1 (mass ratio)) was attached was pressed against the above alignment film at a pressure of 1 kPa for 0.2 seconds to apply a solvent to the alignment film. Thereafter, the solvent-coated portion was dried at room temperature for 15 seconds.

Formation of cholesteric liquid crystal on the alignment film in the same manner as in Example 1. Floor. Further, a TAC film was attached to the liquid crystal layer in the same manner as in Example 2. Thereafter, the alignment film and the PEN film were peeled off 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 on the liquid crystal layer of the optical film obtained in Examples 1 to 3. The pattern formed on the optical film is clear and can be easily visually recognized. Further, it was not confirmed that damage to the liquid crystal layer occurred.

The optical film 100 of the first embodiment is composed of a liquid crystal layer 30/adhesive 40/translucent protective film 50, and a liquid crystal layer 30 is formed with a portion in which the alignment state of the liquid crystal material is different from other regions, thereby forming a belt design. Sexual pattern. However, the optical film of the present invention is not limited to the structure or use method of the optical film 100 of the first embodiment, and various forms disclosed below can be employed.

Second embodiment

In the first embodiment, the pattern is formed by 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 optical film 102 as shown in FIG. 2 may be disposed on the lower surface of the liquid crystal layer 30. A embossed pattern 60 of the hologram is generated. The concavo-convex pattern 60 is provided so as to cover either the portion 30a in which the alignment property disappears in the liquid crystal material of the liquid crystal layer 30 and the portion 30b in which the alignment is maintained. The light that has passed through the liquid crystal layer 30 and reaches the concave-convex pattern 60 generates diffracted light according to the distance between the concave-convex patterns 60 and the incident angle. This diffracted light passes through the liquid crystal layer 30 and thus has optical rotation characteristics peculiar to the liquid crystal layer. In other words, when the liquid crystal layer is a cholesteric liquid crystal that reflects light in the right circle, the diffracted light is again a right circularly polarized light. Therefore, if the optical film 102 is observed by the right circular polarizing filter 120a as shown in FIG. 11, an hologram of a color corresponding to the diffraction pattern such as iridescence can be observed. Further, a pattern formed by the portion 30a and the portion 30b can also be observed. On the other hand, ie It is convenient to observe that the optical film 102 also becomes a dark field by the left circular polarization filter 120b, and neither the diffracted light nor the pattern can be observed.

According to this configuration, the designability can be improved not only by the presence or absence of the alignment of the liquid crystal layer 30 but also by the diffracted light such as the hologram pattern generated from the concave-convex pattern 60. Further, the concavo-convex pattern may be formed by any method such as embossing or nanoimprinting. Further, an adhesive layer such as a sealing material, a release paper, a protective film, a substrate, or the like may be further provided on the lower surface of the concave-convex pattern 60.

Third embodiment

In the second embodiment, the concave-convex pattern 60 is formed on the lower surface of the liquid crystal layer 30. However, the reflective layer 72 having the uneven pattern 60 may be provided on the lower surface of the liquid crystal layer 30 as in the optical film 103 shown in FIG. The reflective layer 72 may also be composed of a cholesteric liquid crystal material that reflects the right circularly polarized light. Similarly to the second embodiment, when the optical film 103 is observed by the right circular polarization filter, the diffracted light of the color corresponding to the diffraction pattern such as iridescence can be observed, and the portion 30a and the portion can be observed. The pattern formed by 30b is a dark field of view even when the optical film 103 is observed by the left circular polarizing filter, and neither the diffracted light nor the pattern can be observed. According to this configuration, the designability can be improved not only by the presence or absence of the alignment of the liquid crystal layer 30 but also by the diffracted light such as the hologram pattern generated from the concave-convex pattern 60. A protective film or a substrate may be further provided on the lower surface of the reflective layer 72.

Fourth embodiment

In the first embodiment, a liquid crystal layer is provided. However, the 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 in which the alignment of the liquid crystal material of the second liquid crystal layer 32 disappears, the portion 32a which maintains the alignment property, and the portion 30a in which the alignment property of the liquid crystal material of the liquid crystal layer 30 disappears is deviated from the maintenance. The position of the in-layer direction of the portion 30b of the alignment. Moreover, the liquid crystal layer 30 and the second liquid crystal layer 32 can also be made The manner in which the layered structures of the liquid crystal materials are different in distance or refractive index causes the colors of the reflected light to be different. For example, the liquid crystal layer 30 is composed of a liquid crystal material which is reflected by the front surface and reflects red, and the second liquid crystal layer 32 is reflected by the front surface and reflects blue. In this case, if the optical film 104 is observed from the front with the naked eye, it looks purple. On the other hand, if the optical film 104 is observed by the right circular polarization filter composed of the liquid crystal material similar to the liquid crystal layer 30, red color can be seen, and if the right circular polarization filter composed of the same liquid crystal material as the liquid crystal layer 32 is used, The viewing optical film looks blue. Thereby, design can be increased.

Instead of changing the reflection color of the liquid crystal layer 30 and the second liquid crystal layer 32 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 right circular light is reflected by the liquid crystal layer 30, and the liquid crystal material of each is adjusted so that the second liquid crystal layer 32 reflects the left circularly polarized light. Therefore, when the optical film 104 is observed by the right circular polarization filter, only the pattern (30a, 30b) formed by the presence or absence of the alignment on the liquid crystal layer 30 is convexly visible, and the optical film is observed by the left circular polarization filter. 104, only the pattern (32a, 32b) formed on the liquid crystal layer 32 by the presence or absence of alignment is visible. In this case, if a combination pattern or a superimposed pattern is produced by 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 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 according to the second or third embodiment.

Fifth embodiment

In the first embodiment, the pattern is formed by 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 optical film 105 as shown in FIG. 5 may be used in the liquid crystal layer. A printed layer 82 is provided on the lower surface of 30. The printed layer 82 may be provided with a logo or design of the manufacturer or operator of the article to which the optical film 105 is attached. Further, the photo may be attached to the printed layer 82 instead of or in addition to the logo or design. The printed layer 82 can be formed by a material having no polarization or optical rotation in a visible manner. Thus, if the liquid crystal layer 30 of the optical film 105 is formed of a liquid crystal material that reflects light in a right circular direction, the left circular polarization filter is used. When the optical film 105 is observed, the mark or design of the printed layer 82 can be observed, but the pattern (30a, 30b) formed by the presence or absence of the alignment in the liquid crystal layer 30 cannot be seen, and the optical film is observed by using the right circular polarizing filter. At 105 hours, the pattern (30a, 30b) formed by the presence or absence of the alignment in the liquid crystal layer 30 can be seen, but the mark or design of the printed layer 82 is hidden by the liquid crystal layer 30 (reflected light from the liquid crystal layer 30) and cannot be seen.

As the printing layer 82, a thermochromic ink or a photochromic ink can also be used. Thereby, the printing layer 82 can be caused to change color by heating or light irradiation, so that the recognition property 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 decorative property can be further increased. For example, a printed layer having a pattern may be provided on the lower surface of the concave-convex pattern of the optical film of the second or third embodiment. In this case, the pattern may be formed to match the concave-convex pattern of the hologram. Thereby, the pattern is superimposed on the hologram pattern when viewed by the viewer, thereby improving the design.

Sixth embodiment

Instead of the printing layer 80 provided in the fifth embodiment, the light absorbing layer 90 may be provided in the lowermost layer as in the optical film 106 shown in FIG. By providing the light absorbing layer 90, the reflected light from the article below the liquid crystal layer 30 can be prevented, so that the pattern formed by the alignment state of the liquid crystal material of the liquid crystal layer can be more easily seen and vivid. The light absorbing layer 90 can be formed, for example, by a pigment or a dye. Into the black printed layer. The light absorbing layer 90 may be disposed on the lower surface of the liquid crystal layer 30 so as to cover the entire surface of the liquid crystal layer 30 or partially cover the liquid crystal layer 30. The design using the light absorbing layer 90 is produced by partially arranging the light absorbing layer 90 on the lower surface of the liquid crystal layer 30 in a specific pattern. As the light absorbing layer 90, not only a material that absorbs visible light but also a material that absorbs ultraviolet rays can be used to form an ultraviolet absorbing layer. Further, the light absorbing layer 90 may be provided in the lowermost layer of the optical film of the first embodiment to the fifth embodiment.

Seventh embodiment

The optical film 100 of the first embodiment has a laminated structure of the liquid crystal layer 30 / the adhesive 40 / the protective film 50. However, the optical film 107 as shown in FIG. 7 may be provided with light transmission between the protective film 50 and the liquid crystal layer 30. Decorative layer 92. The decorative layer 92 can also be a colored light transmissive layer, or a film with a planar logo or design. When the decorative layer 92 is observed by the viewer 120 as shown in FIG. 11, it is preferable to maintain the pattern formed by the alignment state of the liquid crystal material of the liquid crystal layer by transmitting the circularly polarized light reflected from the liquid crystal layer 30. Degree of thickness and transmittance. Thereby, the design can be improved by the optical film 100. The decorative layer 92 may 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 protective film 50 of the optical film 100 of the first embodiment may be directly designed or colored. In this case, the surface of the protective film may be printed, or the protective film 50 may be formed of other materials to which a pigment or a gloss-producing powder is added.

Eighth embodiment

In the second embodiment, the concave-convex pattern 60 is provided on the lower surface of the liquid crystal layer 30. However, in the optical film 108 of the present embodiment, as shown in Fig. 8, a portion thereof, for example, only the left half portion 108a The lower surface of the liquid crystal layer 30 is provided with a concave-convex pattern 60, and only in the right half of the area A region 30a having a different alignment state is disposed in the liquid crystal layer 30 of 108b. Therefore, when the liquid crystal layer 30 is formed of a liquid crystal material which is reflected by the right circularly polarized light, if the optical film 108 is observed through the right circular polarization filter 120a as shown in FIG. 11, the unevenness can be observed from the region 108a. The hologram pattern of the diffracted light generated by the pattern 60 can be visually recognized from the region 108b by the pattern generated by the region 30a having a different alignment state. Therefore, the design can be further improved when both the pattern and the hologram pattern can be observed from various regions.

Ninth embodiment

In the fifth embodiment, a printed layer is provided on the lower surface of the liquid crystal layer. However, in the optical film 109 shown in FIG. 9, a portion of the region, for example, the left half portion 109a may be provided with printing instead of the liquid crystal layer 30. The printed layer 84 of the pattern 84a is provided with the liquid crystal layer 30 only in the region 109b of the right half. Further, only a portion 30a of the liquid crystal layer 30 is provided with a region 30a having a different alignment state. The liquid crystal layer 30 is composed of a liquid crystal material that reflects light in a right circular direction. When the optical film 109 is visually viewed from the front, the printed pattern 84a of the printed layer 84 is visible from the region 109a, and the pattern formed by the region 30a having a different alignment state of the liquid crystal is visible from the region 109b. Further, when the optical film 109 is observed by the right circular polarization filter, the printed pattern can be seen from the region 109a as in the case of visual observation, and the pattern formed by the region 30a having the different alignment state can be seen from the region 109b. When the optical film 109 is observed through the left circular polarization filter, the printed pattern is visible from the region 109a, and the region 109b becomes a dark field. Further, the printed layer 84 and the liquid crystal layer 30 can be made to have the same color, whereby the difference between the observation by the right circular polarizing filter and the observation by the left circular polarizing filter is more remarkable.

Tenth embodiment

Fig. 10 shows a modification of the second embodiment. In the second embodiment, in the liquid crystal layer 30 A concave-convex pattern 60 is formed on the lower surface. However, in the optical film 110 shown in FIG. 10, an intermediate layer 94 having a concave-convex pattern 60 for generating an hologram pattern is provided between the liquid crystal layer 30 and the protective film 50. The concavo-convex pattern 60 is provided on the surface of the intermediate layer 94 opposite to the liquid crystal layer 30. The intermediate layer 94 can be composed of, for example, a cholesteric liquid crystal material that reflects light in a right circular direction, similarly to the liquid crystal layer 30. In this case, if the optical film 110 is visually observed from the front, the hologram pattern formed by the concave-convex pattern 60 can be observed. On the other hand, the pattern formed by the alignment state of the liquid crystal material is colored and visible due to the color shift of the liquid crystal layer 30 as viewed from the oblique direction.

Eleventh embodiment

Fig. 12 shows an optical film 112 in which a microlens array 150 is provided 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 as a grid, and each lens has, for example, a diameter of several μm. The pattern formed by the regions 30a and 30b in which the alignment state of the liquid crystal layer 30 is different is formed by patterning a predetermined stereoscopic image by the microlens array 150 in advance. A three-dimensional stereoscopic image can be regarded by observing the pattern thus formed by the microlens array 150. The microlens array 150 is formed by using acrylic or the like and not generating birefringence, whereby the image that is visible through the viewer and only through the right circular polarizing filter looks solid, so that the image can be given to the visible image. Sex.

Twelfth embodiment

Fig. 13 shows an optical film 114 in which a convex lens-shaped lens array 160 is provided instead of the protective film on the liquid crystal layer 30 of the optical film 100 of the first embodiment. The convex mirror lens array 160 is formed by arranging a plurality of semi-cylindrical convex mirror lenses 160a on a liquid crystal layer 30 in a predetermined direction, and each convex mirror lens has a lateral width of several μm to several mm, for example. The region of the liquid crystal layer 30 below each of the convex mirror lenses 160a is divided into three regions as the regions α, β, and γ, for example, as shown in FIG. Each of α, β, and γ forms a pattern of “units” by constituting regions 30a and 30b in which the alignment state of the liquid crystal layer 30 is different. A pattern is formed by a collection of patterns of the collection regions α. The pattern for the region β and the region γ is also the same. Thereby, when the convex lens-shaped lens array 160 is viewed from a specific direction (specific angle with respect to the optical axis of the convex mirror lens array 160), only the pattern of the area α can be observed. Also, only the pattern of the region β can be observed when the lens array 160 is viewed from the front. Further, when the convex mirror lens array 160 is viewed from the opposite direction to the normal when the pattern of the region α is seen, the pattern of the region γ can be observed. That is, a pattern different depending on the direction of viewing can be observed. Therefore, by forming the convex lens-like lens array 160 in such a manner that birefringence is not generated, the image that is visible through the viewer and passed through the right circular polarization filter looks like a pattern different depending on the direction of observation, so that it can be increased. The design of the pattern. The pattern recorded in the areas α, β, γ may also be an animated pattern or a three-dimensional pattern that is continuously connected according to the direction of viewing.

Thirteenth embodiment

It is also possible to form a pattern by using an IR ink, a UV ink or the like on the upper layer or the lower layer of the light-transmitting protective film 50 of the optical film 100 of the first embodiment. The pattern formed by the ink absorbs infrared light or ultraviolet light and develops color, so it cannot be visually observed, but it can be detected by using infrared rays or ultraviolet rays. Thereby, the pattern of the liquid crystal layer can be detected by the viewer and using visible light, and the pattern formed by the IR ink or the UV ink can be detected by irradiating infrared rays or ultraviolet rays, so that the detection method can be implemented in two stages. Further, in this case, the pattern formed of the IR ink or the UV ink is desirably formed of a material that transmits visible light. A form in which a pattern such as an IR ink or a UV ink is used can be used in combination with the light film of the first embodiment, and can be used in combination with the light film of any of the above embodiments.

Fourteenth embodiment

The optical film of the present invention is preferably used for various purposes as described above, but it is preferable to prevent the optical film temporarily attached to an article such as a product from being peeled off and attached to other articles, that is, to prevent reuse. One of the processes for producing such an optical film which can be prevented from being reused and transferring the liquid crystal layer of the optical film to an article (transferred material) is exemplified in Figs. 14(a) to 14(e).

The laminate system shown in Fig. 14(a) is obtained by the liquid crystal forming step (Fig. 1 (d)) of the process shown in Fig. 1, and the alignment of the liquid crystal layer is fixed by the alignment film on the substrate. Form a pattern. In the first embodiment, the light-transmitting protective film is adhered to the laminated body via an adhesive. However, in this example, the separator is adhered via the paste layer, and as shown in FIG. 14(b), as shown in FIG. 14(b). The layered body. Then, the alignment film of the laminate is peeled off from the substrate and removed to obtain a laminate comprising a liquid crystal layer/paste layer/spacer as shown in Fig. 14(c). Since the laminated body can be attached to various useful articles by peeling off the separator later, it is in the form of a product as a transfer sealing material. Further, in order to protect the surface of the exposed liquid crystal layer of the laminate shown in Fig. 14 (c), a protective film may be provided on the surface of the liquid crystal layer (opposite side of the paste layer). Then, the separator is peeled off from the laminate as shown in Fig. 14 (d) and attached to the article. Thereby, as shown in FIG. 14(e), the liquid crystal layer can be transferred to the article via the separator. Further, when a protective film is provided on the surface of the liquid crystal layer of the laminated body as shown in Fig. 14 (c), the laminated body can be peeled off after being attached to the article. Here, the liquid crystal layer 30 can be produced as a film as thin as 0.3 to 9.0 μm, particularly 0.3 to 6.0 μm as described above, so that the breaking strength of the liquid crystal layer is lower than that of the paste layer, and the paste layer is produced. Elastic deformation and damage to the liquid crystal layer. Therefore, an optical film having a liquid crystal layer cannot be reused.

In the process shown in Figures 14(a) to (e), as a spacer, poly can be used. An olefin resin such as ethylene, polypropylene or 4-methylpentene-1 resin, polyamine, polyamidiamine, polyamidimide, polyetherimine, polyetherketone, polyetheretherketone, Polyether oxime, polyketone sulfide, polyfluorene, polystyrene, polyphenylene sulfide, polyphenylene ether, polyethylene terephthalate (PET), polybutylene terephthalate, polyarylate , polyacetal, uniaxially stretched polyester, polycarbonate, polyvinyl alcohol, polymethyl methacrylate, polyarylate, amorphous polyolefin, norbornene resin, uniaxially stretched polypropylene film (OPP) A film of any material such as triacetyl cellulose (TAC) or epoxy resin. As the triacetyl cellulose (TAC), saponified triethyl cellulose (TAC) as disclosed in JP-A-2004-138697 can also be used.

As long as the paste adheres to the liquid crystal layer and the separator can be attached to the separator, any adhesive or adhesive can be used, and it is also possible to carry out the treatment after the heat treatment such as hot stamping or UV irradiation. Further, as the separator, a transfer belt to which a paste is attached and a separator on both sides thereof, for example, 467MP, 9458, 9626 manufactured by 3M Company, or the like can be used.

Fifteenth embodiment

15(a) to (h) and (h') show modifications of the process described in the fourteenth embodiment. Fig. 15(a) is a laminated body obtained in the liquid crystal forming step (Fig. 1 (d)) in the process shown in Fig. 1. The alignment of the liquid crystal layer is fixed and formed by the alignment film on the substrate. pattern. On the surface of the liquid crystal layer of such a laminate, an adhesive layer is formed as shown in Fig. 15 (b). As the adhesive layer, a hot melt adhesive or a photocurable or electron beam curable reactive adhesive is preferred. The subsequent layer may be selected from any of the specifications that remain or do not remain on the liquid crystal layer after the laminate is finally attached to the article as described below. Next, the separator 1 is attached to the adhesive layer as shown in Fig. 15 (c). As the separator 1, the same material as that of the separator used in the fourteenth embodiment can be used. Then, the alignment film of the laminate is peeled off from the substrate and removed to obtain as shown in FIG. 15(d). A laminate comprising a liquid crystal layer/adhesive layer/spacer 1 is shown. As shown in Fig. 15(e), a spacer layer 2 is interposed between the exposed liquid crystal layer of the laminate and the spacer 2 is obtained, whereby the spacer 2/paste layer/liquid crystal layer/adhesive layer/ The laminate body composed of the separator 1 is formed.

This laminated body can be attached to various useful articles by peeling off the separator 1 and the separator 2, and can be formed into a product form as a sealing material. When the laminate is attached to the article, the separator 2 is peeled off as shown in Fig. 15(g), and the paste of the laminate is interposed and attached to the article. Finally, the adhesive remains and the separator 1 is peeled off to have a form as shown in Fig. 15 (h). By allowing the adhesive to remain on the outermost surface, it can function as a protective film for the liquid crystal layer and can impart heat resistance or light resistance, and can be peeled off after being attached to the article by the thickness or strength of the adhesive layer. .

Alternatively, as shown in FIG. 15 (h'), the separator 1 and the adhesive may be peeled off together to form a form in which only the liquid crystal layer remains on the article via the paste layer, instead of peeling off the separator 1 from the adhesive layer. The form. In this case, the liquid crystal layer 30 can form an extremely thin film of about 1 to 3 μm as described above, so that the film cannot be easily peeled off from the article, and if it is to be peeled off remarkably, the liquid crystal layer itself is broken. Therefore, the light film cannot be reused. Remaining the adhesive layer (Fig. 15 (h)) or not remaining (Fig. 15 (h')) can be considered by considering the adhesion of the adhesive layer to the spacer 1 and the adhesion of the adhesive layer to the liquid crystal layer. The size relationship is determined by selecting the material of the adhesive layer.

The separator 1 , the separator 2, the paste, and the adhesive used in the film of the 14th and 15th embodiments are disclosed in JP-A-2003-121643, JP-A-2004-117522, and JP-A-2004. In No. 138,697, various substances are disclosed as a re-peelable substrate or a separator, or an adhesive or an adhesive for adhering them to a liquid crystalline substance.

Furthermore, Figures 14(a) to (e) and Figs. 15(a) to (h) and (h') indicate An example in which an alignment film is used is used in the same manner as in the first embodiment, but a substrate having an alignment property of the substrate itself may be used. In this case, the alignment film can be omitted.

Although the optical film of the present invention has been described above in various embodiments, the characteristic structure or arrangement described in each embodiment may be incorporated in other embodiments.

For example, the intermediate layer 94 described in the tenth embodiment may be provided so as to cover the upper surface of the printed layer 84 and the liquid crystal layer 30 of the ninth embodiment. In this case, a region having a different alignment state may be provided in only a part of the intermediate layer 94, and a region 30a having a different alignment state may not be disposed in the liquid crystal layer 30 adjacent to the printed layer 84. When the liquid crystal layer 30 is not provided with the region 30a having a different alignment state, the liquid crystal layer 30 may be formed by using a liquid crystal ink in which a small-sized cholesteric liquid crystal is dispersed in an ink medium, without being manufactured by the above method.

Further, the printed layer 82 described in the fifth embodiment or the light absorbing layer 90 described in the sixth embodiment may be provided on the lowermost surface of the optical film of the other embodiment.

In the description of the second embodiment, the adhesive layer such as a sealing material, a release paper, a protective film, a substrate, and the like may be further provided on the lowermost surface (concavo-convex pattern 60) of the optical film 102. However, other embodiments are possible. The optical film may be similarly provided with an adhesive layer such as a sealing member, a release paper, a protective film, a substrate, and the like. The support is not limited to a plastic film such as TAC or PET, and may be a fabric such as a fiber-branded woven fabric or a non-woven fabric attached to a shirt or the like.

Any of the optical films of the above-described embodiments is formed into a pattern or design 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 region 30a or the region 30b may be formed into a dot pattern. , bar code pattern, QR code (registered trademark) and impart information to its pattern or code. Thereby, information such as the product number or the date of manufacture of the optical film itself or the article with the optical film may be attached.

The shape, size, and thickness of the optical film may be arbitrary, and a slit (gap) for preventing the replacement of the optical film may be provided in one portion of the optical film, or an opening may be formed on the optical film such as a donut shape.

The material constituting each layer of the optical film described in the embodiment may be any material as long as it functions as the layer. For example, an additive such as a pigment or a light reflector which causes decoration or coloring may be added to the liquid crystal layer or the protective film. The liquid crystal material can be composed not only of a material that reflects visible light but also a liquid crystal material that reflects only infrared rays. In this case, the liquid crystal layer of the optical film becomes transparent when visually observed. 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 by using an infrared sensor. At this time, after the reflected light is converted into linearly polarized light by the λ/4 plate, it is also received by the polarizing filter that passes through the linearly polarized light.

The embodiments described above are merely illustrative, and modifications may be made by those skilled in the art in the embodiments.

30‧‧‧Liquid layer

30a‧‧‧Part of the disappearance of orientation

30b‧‧‧Part of the maintenance of orientation

40‧‧‧Binder

50‧‧‧Transparent protective film

60‧‧‧ concave pattern

102‧‧‧Optical film

Claims (15)

An optical film having a liquid crystal layer, wherein a liquid crystal material of a part of the liquid crystal layer is the same as a liquid crystal material of another region, and a liquid crystal material of the partial region is different from a liquid crystal material of the other region. The optical film of claim 1, wherein the liquid crystal material in a portion of the liquid crystal layer is not regularly aligned. The optical film of claim 1, wherein the liquid crystal layer is a continuous film formed by applying a liquid crystal material to an alignment film. The optical film of claim 1, wherein the liquid crystal material is a cholesteric liquid crystal. An optical film according to claim 1 further comprising a protective film. An optical film according to claim 1, wherein the surface of the liquid crystal layer is provided with a release sheet which is detachable via a paste layer. The optical film of claim 6, wherein the surface of the liquid crystal layer opposite to the paste layer is provided with another separator which can be peeled off via an adhesive layer. An optical film according to claim 6 is a transfer foil, and the separator is peeled off from the paste layer, and the liquid crystal layer is adhered to the article via the paste layer. The optical film of claim 1, further comprising a microlens array. The optical film of claim 1, further comprising a lenticular lens array. The optical film of claim 1, wherein the liquid crystal layer is formed to have a winding effect The area of shooting ability. An optical film according to claim 1 further comprising a layer exhibiting a diffraction ability. The optical film of claim 1, wherein the lower layer of the liquid crystal layer is provided with a printing layer. An optical film according to claim 1 further comprising a back member. An article provided with the optical film of any one of claims 1 to 14.