CN108292000A - Optical film - Google Patents

Abstract

The optical film 100 of the present invention has protective film 50 and liquid crystal layer 30.The liquid crystal material of a part of region 30a is identical as the liquid crystal material of other regions 30b in liquid crystal layer 30, and the liquid crystal material of a part of region 30a is different from the orientation state of liquid crystal material 30b in other regions.In the lower surface of liquid crystal layer 30, the relief pattern 60 of performance diffracting power can be also set.The present invention provides a kind of can not be damaged to liquid crystal layer and the excellent optical film of the design that simply manufactures.

Description

optical film

technical field

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

Background technique

As a design-imparting film, an optical film on which a hologram (hologram) is formed is known. Such an optical film is produced, for example, by pressing a heated hologram original plate against a cholesteric liquid crystal film formed on an alignment film to transfer a hologram (diffraction grating, etc.) (for example, refer to Patent Document 1). .

Moreover, a sheet with a counterfeit prevention function is also known as an optical film in which a plurality of regions having different selective reflection wavelengths are provided on a cholesteric liquid crystal layer. Such a sheet is produced, for example, by a method of irradiating a cholesteric liquid crystal layer with ultraviolet rays in a pattern through a mask provided with slits in a pattern.

[Background Art Document]

[Patent Document]

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

Contents of the invention

[Problems to be Solved by the Invention]

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 since pressure is applied to the substrate or the liquid crystal layer itself in the heated state, there is a problem that the substrate is damaged. Deformation or damage to the liquid crystal layer, or deviation from the designed selective reflection wavelength, etc.

This invention is made|formed in view of the subject which the said prior art had, and it aims at providing the optical film which can manufacture easily and provide designability, without damaging a liquid crystal layer. Another object of the present invention is to provide an optical film excellent in designability.

[Technical means to solve the problem]

To achieve the above object, the present invention provides an optical film, which has a liquid crystal layer, the liquid crystal material in a part of the liquid crystal layer is the same as the liquid crystal material in other regions, and the liquid crystal material in the above part region is the same as the liquid crystal material in the other regions. Alignment states are different.

According to the manufacturing method of the optical film invented by the inventors of the present invention, the alignment ability of a part of the alignment film is eliminated or weakened by surface treatment, so that the liquid crystal layer formed thereon has the ability to eliminate or weaken the alignment ability. Areas on the film where the liquid crystal material is not aligned, and areas where the alignment state differs from other areas are formed. As a result, it is possible to obtain an optical film in which a design is provided by forming a pattern in regions with different alignment states of the liquid crystal layer. Furthermore, since the regions having different alignment states of the liquid crystal layer can be formed by surface treatment of the alignment film, an optical film having a desired pattern can be easily produced without damaging the liquid crystal layer. Especially in the case of performing surface treatment on the alignment film, no external force is applied after the formation of the liquid crystal layer, so there is no deformation of the substrate or damage to the liquid crystal layer. In addition, since no reheating is performed after the formation of the liquid crystal layer, shifting of the selective reflection wavelength does not occur. Furthermore, as the surface treatment method of the alignment film, the following methods can be mentioned, that is, applying a solvent to a part of the alignment film; utilizing _CO Laser direct drawing; using excimer UV irradiation with a mask (mask); And electron beam (EB, electron beam) drawing. In addition, a method of imparting alignment ability by rubbing with a mask as described below may also be used.

In the optical film of the present invention, the liquid crystal material in a part of the liquid crystal layer may be "irregularly aligned". In the optical film of the present invention, the liquid crystal layer may be a continuous film formed by coating a liquid crystal material on an alignment film. In the optical film of the present invention, the above-mentioned liquid crystal material may also 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 peelable separator through a paste layer on the surface of the liquid crystal layer. Furthermore, another peelable separator may be provided on the surface of the said liquid crystal layer on the opposite side to the said paste layer via an adhesive layer.

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

The optical film of the present invention may have a region expressing diffractive ability formed in the above-mentioned liquid crystal layer, or may further have a layer expressing diffractive ability. The optical film of the present invention may include a printed layer on the lower layer of the liquid crystal layer.

[Effect of the invention]

According to the present invention, an optical film excellent in designability can be obtained with a simple structure.

Description of drawings

Fig.1 (a) - (f) is explanatory drawing for demonstrating one Embodiment of the manufacturing method of the optical film of this invention.

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

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

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

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

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

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

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

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

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

Fig. 11 is an explanatory diagram showing how authenticity of an optical film is observed using a viewer.

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

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

Fig.14 (a) - (e) is a figure which shows the process of transferring the liquid crystal layer of the optical film of 14th Embodiment of this invention to an article (transferred object).

15( a ) to ( h ), ( h' ) are diagrams showing the process of transferring the liquid crystal layer of the optical film according to the fifteenth embodiment of the present invention to an article (transferred object).

Explanation of main figures and symbols:

10: Substrate

20: Alignment film

22: A part of the area (solvent coating part)

30: Liquid crystal layer

32: pattern

40: adhesive

50: Translucent protective film

60: Embossed pattern

70: friction roller

72: reflective layer

80: impression

82, 84: printing layer

90: light absorbing layer

92: decorative layer

94: middle layer

100, 102～110: Optical film

120: Viewer

130: support body

Detailed ways

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In addition, in the drawing, the same code|symbol is attached|subjected to the same or corresponding part, and the overlapping description is abbreviate|omitted. In addition, the dimensional ratios of the drawings are not limited to the ratios shown in the drawings.

1st embodiment

The first embodiment of the optical film of the present invention will be described using FIGS. 1( a ) to ( f ). 1( a ) to ( f ) are explanatory diagrams for explaining the manufacturing method of the optical film of this embodiment.

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

Next, a surface treatment is performed to eliminate or weaken the alignment ability of a part of the region 22 of the alignment film 20 . For example, as shown in FIG. 1( c), the solvent is attached to the stamp (solvent coating means) 80, and it is pressed against a part of the alignment film 20 (solvent coating part) 22 that has been given alignment capability. In this step, a solvent is applied to the region 22 to make the alignment ability of the region 22 disappear (solvent coating step).

As shown in FIG. 1( d ), a liquid crystal composition containing a liquid crystal material is coated on the alignment film 20, and after the liquid crystal material is aligned by heating, 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 part of the region 22 of the alignment film 20 disappears, the liquid crystal material in the region of the liquid crystal layer 30 located on the region 22 is not regularly aligned, and the alignment state of the liquid crystal material is different from other regions. A pattern 32 is formed on the liquid crystal 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 attached on the liquid crystal layer 30 through 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 to obtain an optical film 100 composed of the liquid crystal layer 30 /adhesive 40 /translucent protective film 50 .

According to the above-mentioned manufacturing method, the pattern 32 can be formed on the liquid crystal layer 30 very simply only by applying a solvent on the alignment film 20 through a solvent coating means such as the stamp 80 . In addition, after the liquid crystal layer 30 is formed, there is no need to apply extra external force to form a pattern by pressing against a heated hologram original plate, so the liquid crystal layer 30 will not be damaged. Thereby, by the said manufacturing method, the optical film which provided design property can be manufactured simply, without damaging a liquid crystal layer. Hereinafter, each material and each step used in the above-mentioned 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 , and 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. As a supporting substrate having such a function, for example, polyimide, polyamideimide, polyamide, polyetherimide, polyether ether ketone, polyether ketone, polyketone sulfide (polyketonesulfide) can be mentioned. ), polyethersulfone, polysulfone, polyphenylene sulfide, polyphenylene ether, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyacetal, poly Carbonate, polyarylate, acrylic resin, epoxy resin, phenolic resin, polyvinyl alcohol, cellulosic plastic, or polyethylene, polypropylene, poly(4-methyl-1-pentene), norcamphene Plastic films or sheets formed of chain or alicyclic polyolefins such as resins, etc.

Also, as the substrate 10, a plastic film or sheet that has been subjected to surface treatment such as silicon treatment, or a plastic film or sheet coated with acrylic resin, methacrylic resin, epoxy resin, or a paraffin-based substrate can also be used. Waxed plastic film or sheet, etc. Furthermore, as the substrate 10 , a plastic film or sheet subjected to physical deformation treatment such as embossing, hydrophilization treatment, hydrophobization treatment, or the like may be used.

The thickness of the substrate 10 is usually 8-200 μm, preferably 15-150 μm, more preferably 20-100 μm. When the thickness is thinner than 8 μm, there is a tendency for workability at the time of optical film production to decrease. In addition, when the thickness is thicker than 200 μm, workability tends to decrease when the substrate 10 is peeled off from the liquid crystal layer 30 together with the alignment film 20 .

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

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

The solvent used when forming the alignment film 20 can be appropriately selected according to the material used, and examples thereof include acetone, cyclohexanone, toluene, methyl ethyl ketone, ethyl acetate, water, ethanol, and isopropanol. Furthermore, the solvent used when forming the alignment film 20 is preferably one that does not dissolve the substrate 10 . Therefore, the constituent materials of the alignment film 20 and the constituent materials of the substrate 10 are preferably materials that are selectively dissolved in different solvents.

Drying is performed by performing heat treatment under conditions corresponding to the solvent used. Drying conditions may be appropriately adjusted depending on the type of 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 0.3-6 μm, preferably 0.6-2 μm, more preferably 0.8-1.4 μm. When the thickness is thinner than 0.3 μm, it tends to be easily affected by defects such as fine scratches on the substrate 10 , and when the thickness is thicker than 3 μm, uneven drying tends to easily occur.

The alignment treatment of the alignment film 20 can be performed using a known method, roughly classified into alignment by rubbing treatment and alignment by other methods. As the rubbing treatment, there is a method of using a rubbing roller 70 as shown in FIG. 1( b ). Alignment methods other than this include a method of aligning by stretching, a method of aligning by imprinting, and a method of aligning using an ultraviolet alignment device, a soft X-ray alignment device, or the like.

The solvent used in the solvent coating step is not particularly limited as long as it can eliminate the alignment ability of the alignment film 20 , and a solvent that can dissolve the constituent materials of the alignment film 20 is usually used. As the solvent used in the solvent coating step, the same solvent as that used for forming the alignment film 20 may be used, or a different solvent may be used, or a combination of multiple solvents may be used.

The solvent coating method is not particularly limited as long as it is a method that can apply a solvent to the alignment film 20. In addition to the method of using the stamp 80 shown in FIG. Spraying, printing with inkjet printers, gravure printing, letterpress printing, etc.

The coating amount of the solvent may be appropriately adjusted as long as it is an amount capable of disabling the alignment ability of the partial region 22 of the alignment film 20 .

After the solvent is applied to the partial region 22 of the alignment film 20, the solvent is dried. Drying conditions may be appropriately adjusted depending on the type of solvent used, etc., and are usually at room temperature for 10 to 30 seconds.

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

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

The polymer liquid crystal is not particularly limited as long as it is a polymer liquid crystal whose cholesteric alignment can be immobilized, and either a main chain type or a side chain type polymer liquid crystal can be used. Specifically, main-chain liquid crystal polymers such as polyester, polyamide, polycarbonate, and polyesterimide; polyacrylate, polymethacrylate, polymalonate, polysiloxane, etc.; and other side chain liquid crystal polymers. Among these, liquid crystalline polyesters that form a cholesteric alignment, have better orientation, and are easier to synthesize are preferable. As a structural unit of a polymer, an aromatic or aliphatic diol unit, an aromatic or aliphatic dicarboxylic acid unit, and an aromatic or aliphatic hydroxycarboxylic acid unit are mentioned as preferable examples, for example.

Furthermore, examples of cross-linked low-molecular liquid crystals include biphenyl derivatives, phenyl benzoate derivatives, and stilbene derivatives based on, for example, introduced functional groups such as acryloyl groups, vinyl groups, and epoxy groups. Skeleton cross-linked low-molecular liquid crystal. Also, as the cross-linked low-molecular liquid crystal, any one of a cross-linked low-molecular liquid crystal showing lyotropic properties and a cross-linked low-molecular liquid crystal showing thermotropic properties can be used, but A cross-linked low-molecular liquid crystal showing thermotropism is more preferable from the standpoint of workability and the like.

As a method for immobilizing the cholesteric alignment, known methods can be used. For example, when polymer liquid crystal is used as the liquid crystal material, the following method can be used, that is, after the polymer liquid crystal is coated on the alignment film 20, it is made to develop a cholesteric liquid crystal phase by heat treatment or the like, and from the state Rapid cooling immobilizes the cholesteric alignment. In addition, when the cross-linked low-molecular liquid crystal is used as the liquid crystal material, the following method can be suitably adopted, that is, after the cross-linked low-molecular liquid crystal is coated on the alignment film 20, it is developed by heat treatment or the like. The cholesteric liquid crystal phase is maintained, and the liquid crystal is cross-linked by light, heat, or electron beams to fix the cholesteric alignment.

In addition, in order to improve the heat resistance of the cholesteric liquid crystal layer, in addition to adding high-molecular liquid crystals or cross-linked low-molecular liquid crystals, it is also possible to add, for example, diazide (bisazid) compounds or methyl Glycidyl acrylate and other cross-linking agents. By adding these crosslinking agents, it becomes possible to crosslink in the state which developed the cholesteric liquid crystal phase. Furthermore, various additives such as dichroic dyes, dyes, and pigments may 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-mentioned cholesteric liquid crystal layer, but may be a configuration in which a plurality of liquid crystal layers are laminated as needed.

The thickness of the liquid crystal layer 30 is usually 0.3-20 μm, preferably 0.5-10 μm, more preferably 0.7-3 μm. When the thickness is less than 0.3 μm, there is a possibility that the effect of specific optical characteristics cannot be effectively expressed, and when the thickness exceeds 20 μm, uneven drying tends to easily occur. Furthermore, when 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 within the above-mentioned range.

As described above, in the liquid crystal layer 30 , in the region above the partial region 22 where the alignment ability of the alignment film 20 is lost, a portion where the alignment state of the liquid crystal material is different from other regions is formed. When the liquid crystal layer 30 is made of cholesteric liquid crystal, the alignment structure of the liquid crystal molecules is regularly twisted so as to draw a spiral in the film thickness direction, and the orientation of the liquid crystal molecules is consistent in the same plane. On the other hand, the orientation of the liquid crystal molecules in the region where the alignment ability is lost is inconsistent and random in the same plane, forming a different pattern 32 depending on how the reflected light is viewed visually.

On the liquid crystal layer 30 , a translucent protective film 50 is attached via an adhesive 40 . As the adhesive agent 40, as long as it is an adhesive agent that can bond the liquid crystal layer 30 and the translucent protective film 50, and is transparent to the extent that the pattern 32 formed on the liquid crystal layer 30 can be visually recognized through the adhesive agent 40, The adhesive is not particularly limited, and various conventionally known adhesives and adhesives 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, reactive adhesives are preferred from the viewpoint of workability and the like.

The hot-melt adhesive is not particularly limited, but from the standpoint of workability, the working temperature of the hot-melt is preferably 250°C or lower, preferably 80-200°C, more preferably about 100-160°C. As the hot-melt adhesive, for example, ethylene-vinyl acetate copolymer resins, polyester resins, polyurethane resins, polyamide resins, thermoplastic rubber resins, polyacrylic resins, Polyvinyl alcohol-based resins, polyvinyl acetal-based resins such as polyvinyl butyral, petroleum-based resins, terpene-based resins, rosin-based resins, and the like are used as hot-melt adhesives for the matrix resin.

As a reactive adhesive, other monofunctional or polyfunctional monomers, various polymers, stabilizers, photopolymerization initiators, sensitizers, etc. can be blended to have photopolymerization or electron beam polymerization used in prepolymers and/or monomers.

Specific examples of photopolymerizable or electron beam polymerizable prepolymers include polyester acrylate, polyester methacrylate, polyurethane acrylate, polyurethane methacrylate, epoxy acrylate, epoxy methyl Acrylate, polyol acrylate, polyol methacrylate, etc. In addition, examples of photopolymerizable or electron beam polymerizable monomers include monofunctional acrylates, monofunctional methacrylates, bifunctional acrylates, bifunctional methacrylates, and trifunctional or higher polyfunctional acrylates. , Multifunctional methacrylate, etc. In addition, these can also use commercially available products, such as Aronix (acrylic acid-based special monomer, oligomer; manufactured by Toagosei Co., Ltd.), Lightester (manufactured by Kyoeisha Chemical Co., Ltd.), Viscoat (manufactured by Osaka Organic Chemical Industry Co., Ltd. Shares) manufacturing) etc. can also be used in the present invention.

In addition, as photopolymerization initiators, for example, benzophenone derivatives, acetophenone derivatives, benzoin derivatives, thioxanthones, Michler's ketone, benzil derivatives, Triazine derivatives, acylphosphine oxides, azo compounds, etc.

The viscosity of the photocurable or electron beam curable reactive adhesive that can be used in the present invention is appropriately selected according to the processing temperature of the adhesive, etc. Although it cannot be generalized, it is usually 10 to 2000 mPa·s at 25°C, which is relatively low. It is 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 the desired thickness. Moreover, when it exceeds 2000 mPa·s, there exists a possibility that workability|operativity may fall, and it is not preferable. When the viscosity deviates from the above-mentioned range, it is preferable to adjust the ratio of the solvent or the monomer appropriately so as to obtain the desired viscosity.

In addition, in the case of using a photocurable reactive adhesive, known curing methods such as low-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, metal halide lamps, and xenon lamps can be used as the curing method of the adhesive. Wait. Also, since the amount of exposure varies depending on the type of reactive adhesive used, it cannot be generalized, but it is usually 50 to 2000 mJ/cm ² , preferably 100 to 1000 mJ/cm ² .

Also, when using an electron beam hardening type reactive adhesive, as the curing method of the adhesive, it is appropriately selected according to the transmission power or hardening power of the electron beam. It is hardened by irradiation under the condition of a voltage of 50-1000kV, preferably 100-500kV.

The thickness of the adhesive 40 is not particularly limited, but is usually 0.5-50 μm, preferably 1-10 μm. In addition, as a method for 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, and a gravure roll coating method can be used. , spray coating method, spin coating method and other known methods.

The translucent protective film 50 is not particularly limited as long as it is transparent to the extent that the pattern 32 formed on the liquid crystal layer 30 can be visually recognized through the translucent protective film 50, and examples thereof include Triacetylcellulose (TAC), polymethylmethacrylate, polystyrene, polycarbonate, polyethersulfone, polyphenylene sulfide, amorphous polyolefin, polyethylene terephthalate, polyethylene naphthalate Films formed of ethylene glycol, cycloolefin polymer (COP, cycloolefin polymer), polyvinyl alcohol, etc. The translucent protective film 50 may contain an ultraviolet absorber. In addition, the translucent protective film 50 may be a hard coat layer. Moreover, when using as a hard-coat layer, you may contain beads or metal powder (glitter) in order to improve design property. Also, for the purpose of adding antireflection, an antireflection film may be used as a protective film, or an antireflective layer may be formed on the protective film.

The thickness of the translucent 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, for example, it can be carried out by the following method: attaching an adhesive tape to the corner or end of the alignment film 20 or the substrate 10 and manually peeling off; A method of mechanical peeling using a roller or the like; a method of mechanical peeling after immersion in a poor solvent for all structural materials; a method of peeling by applying ultrasonic waves in a poor solvent; and using the alignment film 20 or the substrate 10 and the liquid crystal layer The method of exfoliating by giving a temperature change due to a difference in thermal expansion coefficient of 30, etc.

The method for producing the optical film of the present invention has been described. In the optical film of the present invention, the liquid crystal material in a part of the liquid crystal layer is the same as the liquid crystal material in other regions, and the alignment of the liquid crystal material in the part region and the liquid crystal material in the other region is the same. The state is different, but the optical film of the present invention can also be produced by other production methods. For example, as shown in FIG. 1( a ), an alignment film 20 is formed on a substrate 10 . Next, a mask having an opening in a predetermined region is placed on the alignment film in order to impart alignment capability only to a predetermined region. Next, rubbing treatment is performed using a rubbing roll from above the mask, similarly to the above-mentioned embodiment. Thereby, alignment capability can be imparted only to the alignment film exposed in a predetermined area of the opening of the mask. Next, a liquid crystal composition containing a liquid crystal material can be applied on the alignment film in the same manner as in the above embodiment, and the liquid crystal material can be aligned by heating, and then the alignment can be fixed to form a liquid crystal layer. At this time, because there is no alignment ability in the area other than the specified area of the alignment film, the liquid crystal material is not regularly aligned in the area of the liquid crystal layer located on the area, and the alignment state of the liquid crystal material is different from the specified area. The liquid crystal layer is patterned. Finally, in the same way as the above-mentioned embodiment, the light-transmitting protective film is attached to the liquid crystal layer through the adhesive, and the alignment film and the substrate are peeled and removed from the liquid crystal layer, so that the liquid crystal layer/adhesive/light-transmitting layer can be obtained. An optical film composed of a protective film.

In addition, the surface treatment of the alignment film can be performed by using methods such as direct drawing with a _CO2 laser, UV irradiation with a mask, or electron beam (EB) drawing to form a liquid crystal layer in the same way. Regions with different alignment states.

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 to one side of the liquid crystal layer 30 and affixing it to a signboard, a label, a vanity case, a packaging material, or a packaging material. There may also be patterns on these. Also, as described in detail in the following embodiments, the optical film 100 can be automatically formed by applying an adhesive layer such as hot melt or electromagnetic wave-curable resin on the side of the liquid crystal layer 30, and then bringing the adhesive layer side into contact with an item such as a signboard. One side of the light-transmitting protective film 50 is bonded to items such as a signboard by hot stamping or electromagnetic wave irradiation. Moreover, by using a member with low solvent resistance, such as a COP film, for the translucent protective film 50, reuse by peeling off a film using a solvent can be prevented. Water-soluble films and the like can also be used for the same purpose. Furthermore, the adhesive agent 40 and the translucent protective film 50 can be peeled and used as a transfer foil.

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

(1) Colored rear member

By changing the color of the "back member" (sign, label, etc.) attached to the liquid crystal layer 30 side or the pattern arranged on it to black (green), white (red), blue (blue), etc. And the visual color is also different. For example, the liquid crystal layer 30 is formed of a liquid crystal material that reflects green right circularly polarized light. In the above case, when the color of the back member is black, the color when viewed from the front side of the liquid crystal layer (strictly speaking, the color when the adhesive and the translucent protective film are peeled off and viewed) is green, but When the back component is set to white, it appears to be its complementary color, red. Also, when the back member is blue, it looks blue. Therefore, although it is a monochromatic optical film, RGB colors can be expressed by changing the color of a back surface member. When an optical film having such a rear member is observed through a left circular polarizing filter of a viewer described below, the pattern of the liquid crystal layer disappears, and only the pattern and color of the rear member can be seen.

(2) Rear member having an inclined concave-convex structure

The back member may also have a concave-convex structure with an inclination on its surface. The concavo-convex structure has a size in nanometer to millimeter units, and can be formed by a known method such as nanoimprinting or embossing. When the incident light has an incident angle θ, light of wavelength λ that satisfies Bragg's reflection condition of p·cosθ=λ/n (p is the thickness of the back member, and n is the refractive index of the back member) is selected by diffraction reflexively. Therefore, shorter wavelength colors are observed when viewed at an angle. The light of wavelength λ diffracted in the front direction passes through the helical structure of the liquid crystal through the inclined concavities and convexities on the back. Therefore, even when viewed from the front, the same effect as that observed with an angle can be obtained, and multiple colors can be displayed. Since colorization can be realized by adjusting the inclination angle, there is an effect of improving designability.

(3) Rear member as 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 rear surface member, and a reflective layer may be provided thereon. By setting the reflective layer, the transmitted reverse twisted circular polarized light is returned, so the pattern of the cholesteric layer will not disappear due to the circular polarizer (and the linear polarizer). On the other hand, although the retardation film is transparent when observed with the naked eye, it is in a state of being colored and recognizable when observed through a linear polarizing plate. In addition, when the retardation film is arranged under the cholesteric liquid crystal, the non-aligned portion of the cholesteric liquid crystal can be seen without the polarizing plate.

(4) As the rear member of the mirror member

A rear surface member composed of a transparent member (glass, film)/reflecting portion can also be used. The reflective portion may be formed entirely or partially. If there is a reflective part, the pattern will not disappear in a viewer using a circular polarizing filter. It is possible to use reflective materials such as aluminum foil to draw patterns or characters on the backing paper supported on the back. Or it is also possible to draw a pattern 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 reflection image on the surface of the transparent member and the reflection image on the reflection part will deviate, and the pattern protrusion of the cholesteric liquid crystal layer can be seen visually (Suspected 3D pattern). Thereby, design property improves. The various rear members as described above can be formed of materials such as PET, COP, and TAC, for example.

The optical film of the present invention is extremely versatile and can be used as various optical components or optoelectronic device components, decorative members, anti-counterfeiting components, and the like. In particular, it can be used as a new film, sealing member, signboard, etc. that have both the effects of the diffraction element and the cholesteric liquid crystal. For example, it can be attached or embedded to support substrates such as card-type substrates such as driver's licenses, ID cards, passports, credit cards, prepaid cards, various vouchers, gift cards, securities, etc., and backing paper. Also, as a seal, it can be attached to products such as batteries, cameras, calculators, and watches. As an identification tag, for example, it can be used as a fiber identification tag sewn on clothes such as a tie or a shirt.

Especially when used as an anti-counterfeiting component, in order to confirm the authenticity of the optical film or the transfer material transferred therefrom, a viewer 120 as shown in FIG. 11 is generally used. At the two openings of the viewer 120, a right circular polarization filter 120a passing only right circularly polarized light and a left circular polarization filter 120b passing only left circularly polarized light are attached. Here, the liquid crystal layer of the optical film 100 of the embodiment mounted on a support 130 such as a card is made of a liquid crystal material that reflects only right circularly polarized light. If the optical film 100 is irradiated with natural light having a polarized component in a random direction, only the right circularly polarized light is reflected from the liquid crystal layer of the optical film 100, and the reflected light passes through the right circularly polarized filter 120a of the viewer 120, so it can be The pattern or design attached to the liquid crystal layer is seen through the right circular polarizing filter 120a. On the other hand, the right circularly polarized light reflected from the liquid crystal layer cannot pass through the left circularly polarized filter 120b, so the pattern or design attached to the liquid crystal layer cannot be seen. For the purpose of identification only, it is also possible to design a circular polarizing filter that cannot see the direction of rotation.

[Example]

Hereinafter, although the example of the optical film which concerns on 1st Embodiment is demonstrated more concretely, this invention is not limited to a following example.

(Example 1)

A PET (polyethylene terephthalate) film was used as the substrate. The PET film has the ability to align and doubles as an alignment film. The toluene-attached stamp was pressed against the PET film at a pressure of 10 kPa for 0.2 seconds, and then dried at room temperature for 15 seconds.

Nematic liquid crystal (manufactured by PALIOCOLOR LC242BASF (KK)) 19.0% by weight, chiral agent (manufactured by PALIOCOLOR LC756BASF (KK)) 1.0% by weight, acyl phosphine oxide photopolymerization initiator (manufactured by IRGACURETPO BASF (KK)) 0.8 % by weight and a solution consisting of 79.2% by mass of cyclohexanone was applied on a PET film so that the thickness after drying would be 1.6 μm, and dried by heating in a drying oven at 55° C. for 15 minutes. Then, place it in a heat treatment furnace heated to 100°C for 10 minutes, and place it in a heat treatment furnace heated to 80°C for 10 minutes to align the liquid crystal, and then irradiate with light from an LED-UV lamp to fix the alignment and form a cholesteric liquid crystal. Floor.

On the above liquid crystal layer, a PC (polycarbonate) film is attached through an ultraviolet curable adhesive (manufactured by Toagosei Co., Ltd., trade name: ARONIXUV-3630), and the adhesive is cured by light irradiation with a high-pressure mercury lamp . Then, the PET film was peeled from the liquid crystal layer, and the optical film which consists of a liquid crystal layer/adhesive agent/PC film was obtained.

(Example 2)

A solution composed of 4% by mass of PVA (polyvinyl alcohol), 76.8% by mass of pure water, and 19.2% by mass of IPA (isopropyl alcohol) was applied to PEN (polynaphthalene) so that the thickness after drying became 1.2 μm. Ethylene formate) film, make it dry from 40 ℃ to 130 ℃ in a high-temperature drying oven for 36 seconds to form a PVA film. A low-density polyethylene film cut into characters and having a thickness of 30 μm was attached to the PVA film, and a rubbing treatment was performed using a rubbing roll attached with a rubbing cloth to form an alignment film.

A cholesteric liquid crystal layer was formed on the alignment film in the same manner as in Example 1. Furthermore, except having used the TAC (triacetyl cellulose) film instead of the PC film, it carried out similarly to Example 1, and stuck the TAC film on the liquid crystal layer. 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 agent/TAC film.

(Example 3)

An alignment film was formed in the same manner as in Example 2 except that the entire PVA film was rubbed without using a polyethylene film cut into characters.

A stamp attached with a mixed solvent of water and ethanol (water:ethanol=2:1 (mass ratio)) was pressed against the alignment film at a pressure of 1 kPa for 0.2 seconds, thereby coating the solvent on the alignment film. Thereafter, the portion coated with the solvent was dried at room temperature for 15 seconds.

A cholesteric liquid crystal layer was formed on the alignment film in the same manner as in Example 1. Furthermore, in the same manner as in Example 2, the TAC film was attached on the liquid crystal layer. 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 agent/TAC film.

It was confirmed that the pattern of the stamper was formed on the liquid crystal layer of the optical film obtained in Examples 1-3. The pattern formed on the optical film is clear and can be recognized easily. Also, no damage to the liquid crystal layer was confirmed.

The optical film 100 of the first embodiment is composed of a liquid crystal layer 30/adhesive 40/translucent protective film 50, and a part where the alignment state of the liquid crystal material is different from other regions is formed on the liquid crystal layer 30, thereby forming an optical film with a design. sexual pattern. However, the optical film of the present invention is not limited to the structure or usage method of the optical film 100 of the first embodiment, and may take various forms disclosed below.

Second Embodiment

In the first embodiment, the pattern is formed by the alignment state of the liquid crystal material of the liquid crystal layer, but in order to further increase the design of the pattern, it can also be arranged on the lower surface of the liquid crystal layer 30 like the optical film 102 shown in FIG. The relief pattern 60 of the hologram. The concavo-convex pattern 60 is provided so as to cover either the portion 30 a where the alignment is lost or the portion 30 b where the alignment is maintained in the liquid crystal material of the liquid crystal layer 30 . 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 . The diffracted light passes through the liquid crystal layer 30 and thus has optical activity specific to the liquid crystal layer. That is, when the liquid crystal layer is a cholesteric liquid crystal that reflects right circularly polarized light, the diffracted light becomes right circularly polarized light again. Therefore, when the optical film 102 is observed using the right circular polarizing filter 120 a as shown in FIG. 11 , a hologram of a color corresponding to the diffraction pattern like an iridescent color can be observed. Furthermore, the pattern formed by the portion 30a and the portion 30b can also be observed. On the other hand, even if the optical film 102 is observed with the left circular polarizing filter 120b, it becomes a dark field, and neither the diffracted light nor the pattern can be observed.

According to such a configuration, not only the presence or absence of alignment of the liquid crystal layer 30 but also the diffracted light like a hologram generated from the concave-convex pattern 60 can increase designability. In addition, the concave-convex pattern can be formed by any method such as embossing or nanoimprinting. Adhesive layers such as adhesive seals, release paper, protective films, substrates, etc. can also be further provided on the lower surface of the concave-convex pattern 60 .

3rd embodiment

In the second embodiment, the concavo-convex pattern 60 is formed on the lower surface of the liquid crystal layer 30 , but a reflective layer 72 having the concavo-convex pattern 60 may be provided on the lower surface of the liquid crystal layer 30 like the optical film 103 shown in FIG. 3 . The reflective layer 72 can also be made of a cholesteric liquid crystal material that reflects right circularly polarized light. Similar to the second embodiment, if the optical film 103 is observed with a right circular polarizing filter, in addition to observing the diffracted light of a color corresponding to the diffraction pattern such as iridescent, it is also possible to observe the difference between the portion 30a and the portion 30a. 30b, even if the optical film 103 is observed with a left circular polarizing filter, it becomes a dark field, and neither the diffracted light nor the pattern can be observed. According to such a configuration, not only the presence or absence of alignment of the liquid crystal layer 30 but also diffracted light such as a hologram generated from the concave-convex pattern 60 can increase designability. 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, one liquid crystal layer is provided, but a second liquid crystal layer 32 may be provided on the lower surface of the liquid crystal layer 30 like the optical film 104 shown in FIG. 4 . In this case, the portion 32a where the alignment of the liquid crystal material of the second liquid crystal layer 32 is lost and the portion 32b that maintains the alignment, and the portion 30a that loses the alignment of the liquid crystal material of the liquid crystal layer 30 and the portion 30a that maintains the alignment can be separated. The position of the portion 30b in the layer direction deviates. In addition, the liquid crystal layer 30 and the second liquid crystal layer 32 may have different colors of reflected light so that the pitch or refractive index of the layered structure of the liquid crystal material is different. For example, the liquid crystal layer 30 is made of a liquid crystal material that reflects red by front reflection, and the second liquid crystal layer 32 is made of a liquid crystal material that reflects blue by front reflection. In this case, when the optical film 104 is observed from the front with the naked eye, it appears purple. On the other hand, if the optical film 104 is observed with a right circular polarizing filter made of the same liquid crystal material as the liquid crystal layer 30, red can be seen. The optical film looks blue when viewed with an instrument. Thereby, designability can be increased.

Instead of making the reflection colors of the liquid crystal layer 30 and the second liquid crystal layer 32 different as described above, the optical rotations of the circularly polarized light reflected by the liquid crystal layer 30 and the second liquid crystal layer 32 may be reversed. For example, the respective liquid crystal materials are adjusted so that the liquid crystal layer 30 reflects right circularly polarized light and the second liquid crystal layer 32 reflects left circularly polarized light. Thereby, if the optical film 104 is observed with a right circular polarizing filter, only the patterns (30a, 30b) formed by the presence or absence of alignment on the liquid crystal layer 30 are visible, and if the optical film 104 is observed with a left circular polarizing filter As for the film 104, only the patterns (32a, 32b) formed on the liquid crystal layer 32 by the presence or absence of alignment are projected and visible. In this case, if a combined pattern or overlapping pattern is generated from the pattern of the liquid crystal layer 30 and the pattern of the second liquid crystal layer 32, the visual design property will be improved.

The liquid crystal layer is not limited to two layers, and may be multilayered with three or more layers. Moreover, it is also possible to introduce a some liquid crystal layer like this embodiment into the optical film which has a concavo-convex pattern of 2nd or 3rd embodiment.

Fifth Embodiment

In the first embodiment, a pattern is formed by the alignment state of the liquid crystal material of the liquid crystal layer, but in order to further increase the designability of the pattern, an optical film 105 as shown in FIG. 5 can also be provided on the lower surface of the liquid crystal layer 30. Print layer 82 . A mark or a design of a manufacturer, an operator, or the like of the article to which the optical film 105 is attached may be given to the printed layer 82 . In addition, a photograph may be attached to the printed layer 82 instead of a logo or a design, or in addition thereto. The printed layer 82 can be made of a non-polarized optically active or optically active material in a visible manner. By this, if the liquid crystal layer 30 of the optical film 105 is formed of a liquid crystal material that reflects right circularly polarized light, it can be used in left When the circular polarizing filter observes the optical film 105, the logo or design of the printing layer 82 can be observed, but the pattern (30a, 30b) formed by the presence or absence of alignment in the liquid crystal layer 30 cannot be seen, and when using the right circular polarizing filter When the optical film 105 is observed with an optical device, the patterns (30a, 30b) formed by the presence or absence of alignment in the liquid crystal layer 30 can be seen, but the logo 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, it can also be comprised using thermochromic ink or photochromic ink. Thereby, the color change of the printed layer 82 can be caused by heating or light irradiation, and visibility can be improved.

Decorative properties can be further increased by providing such a printed layer 82 on the lowermost layer of the optical films of the first to fourth embodiments. For example, a printed layer having a pattern may be provided on the lower surface of the concave-convex pattern of the optical film according to the second or third embodiment, and in this case, the pattern may be formed so as to match the concave-convex pattern of the hologram. Thereby, when viewed through a viewer, the pattern and the pattern of the hologram are superimposed and visible, thereby improving designability.

Embodiment 6

Instead of the printed layer 80 provided in the fifth embodiment, the light absorbing layer 90 may be provided as the lowermost layer like the optical film 106 shown in FIG. 6 . Reflected light from objects under the liquid crystal layer 30 can be prevented by providing the light absorbing layer 90 , so that the pattern formed by the alignment state of the liquid crystal material of the liquid crystal layer can be seen more easily and clearly. The light-absorbing layer 90 can be used as a black printing layer formed of pigment or dye, for example. The light absorbing layer 90 may be provided 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 . A design using the light absorbing layer 90 is produced by partially disposing the light absorbing layer 90 in a specific pattern on the lower surface of the liquid crystal layer 30 . 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-ray absorbing layer. In addition, the light absorption layer 90 may be provided in the lowermost layer of the optical film of 1st Embodiment - 5th Embodiment.

Seventh Embodiment

The optical film 100 of the first embodiment has a laminated structure of liquid crystal layer 30/adhesive 40/protective film 50, but a transparent layer may be provided between the protective film 50 and the liquid crystal layer 30 like the optical film 107 shown in FIG. Optical decorative layer 92 . The decorative layer 92 may also be a colored translucent layer, or a film on which a flat logo or design is applied. When the decorative layer 92 is observed with a viewer 120 as shown in FIG. 11 , it is desirable to maintain the pattern formed by the alignment state of the liquid crystal material of the liquid crystal layer so that the circularly polarized reflected light from the liquid crystal layer 30 can be transmitted. degree of thickness and transmittance. Thereby, the designability of the optical film 100 can be improved. The decoration 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 through the adhesive 40 .

Instead of providing the decorative layer 92, it is also possible to directly give a design or color to the protective film 50 of the optical film 100 of the first embodiment. In such a case, printing may be performed on the surface of the protective film, or the protective film 50 may be formed from other materials to which pigments or glossy powders are added.

Eighth embodiment

In the second embodiment, the concavo-convex pattern 60 is provided on the lower surface of the liquid crystal layer 30, but in the optical film 108 of this embodiment, as shown in FIG. The lower surface of the liquid crystal layer 30 is provided with a concavo-convex pattern 60 , and only the right half region 108 b of the liquid crystal layer 30 is provided with regions 30 a with different alignment states. Thus, when the liquid crystal layer 30 is made of a liquid crystal material that reflects right circularly polarized light, if the optical film 108 is observed through the right circularly polarized light filter 120a shown in FIG. The pattern of the hologram of the diffracted light generated by 60, and the pattern generated by the region 30a with different alignment states can be seen from the region 108b. Therefore, when both the isopattern and the hologram pattern can be observed from each area, the design property can be further improved.

Embodiment 9

In the fifth embodiment, a printed layer is provided on the lower surface of the liquid crystal layer, but in the optical film 109 shown in FIG. The printing layer 84 of the pattern 84a, and the liquid crystal layer 30 is only provided in the region 109b of the right half. Furthermore, only a part of the liquid crystal layer 30 is provided with a region 30 a having a different alignment state. The liquid crystal layer 30 is made of a liquid crystal material that reflects right circularly polarized light. When the optical film 109 is viewed from the front, the printed pattern 84a of the printed layer 84 can be seen from the region 109a, and the pattern formed by the regions 30a having different alignment states of the liquid crystal can be seen from the region 109b. Also, when the optical film 109 is observed through a right circular polarizing filter, a printed pattern can be seen from the region 109a, and a pattern formed by the regions 30a having different alignment states can be seen from the region 109b, similarly to visual observation. When the optical film 109 is observed through a left circular polarizing filter, the printed pattern can be seen from the region 109a, and the region 109b becomes a dark field. Furthermore, the printing layer 84 and the liquid crystal layer 30 can be made to have the same color, whereby the difference between visual observation and observation through a right circular polarizing filter and observation through a left circular polarizing filter is more obvious.

Tenth Embodiment

Fig. 10 shows a modified example of the second embodiment. In the second embodiment, the concave-convex pattern 60 is formed on the lower surface of the liquid crystal layer 30, but in the optical film 110 shown in FIG. The intermediate layer 94 of the concave-convex pattern 60. The concavo-convex pattern 60 is provided on the surface of the intermediate layer 94 facing the liquid crystal layer 30 . The intermediate layer 94 may be made of a cholesteric liquid crystal material that reflects right circularly polarized light, for example, like the liquid crystal layer 30 . In this case, when the optical film 110 is seen from the front, the hologram pattern formed by the uneven|corrugated pattern 60 can be observed. On the other hand, due to the color shift of the liquid crystal layer 30 viewed from an oblique direction, the pattern formed by the alignment state of the liquid crystal material is colored and visible.

Eleventh Embodiment

FIG. 12 shows an optical film 112 provided with a microlens array 150 instead of the protective film on the liquid crystal layer 30 of the optical film of the first embodiment. The microlens array 150 is formed by arranging a plurality of microlenses 150 a in a grid on the liquid crystal layer 30 , and each lens has a diameter of several μm, for example. The pattern formed by the regions 30 a and 30 b having different alignment states of the liquid crystal layer 30 is formed by imaging a predetermined three-dimensional image with the microlens array 150 in advance. The thus-formed pattern can be seen as a three-dimensional stereoscopic image by observing it through the microlens array 150 . The microlens array 150 is formed using acrylic or the like so as not to cause birefringence, so that the image visible only through the right circular polarizing filter through the viewer appears three-dimensional, so that the visible image can be given a design. sex.

Twelfth Embodiment

FIG. 13 shows an optical film 114 provided with a lenticular lens array 160 instead of the protective film on the liquid crystal layer 30 of the optical film 100 according to the first embodiment. The lenticular lens array 160 is formed by arranging a plurality of semicylindrical lenticular lenses 160 a in a predetermined direction on the liquid crystal layer 30 , and each lenticular lens has a lateral width of, for example, several μm to several mm. The region of the liquid crystal layer 30 below each lenticular lens 160a is divided into, for example, three regions α, β, and γ as shown in FIG. Regions 30a and 30b in different states form a "unit" pattern. One pattern is constituted by an aggregate of patterns in the region α. The same applies to the patterns of the region β and the region γ. Thus, when the lenticular lens array 160 is observed from a specific direction (a specific angle with respect to the optical axis of the lenticular lens array 160 ), only the pattern of the region α can be observed. Also, when the lens array 160 is viewed from the front, only the pattern of the region β can be observed. Also, when the lenticular lens array 160 is viewed from a direction opposite to the normal when the pattern of the region α is seen, the pattern of the region γ can be observed. That is, different patterns can be observed depending on the viewing direction. Therefore, by forming the lenticular lens array 160 in a manner that does not cause birefringence, the image visible through the viewer and through the right circular polarizing filter looks like a different pattern depending on the direction of observation, so the pattern can be increased. of design. The patterns recorded in the areas α, β, and γ may be continuous animation-like patterns or patterns that appear to be three-dimensional depending on the viewing direction.

Thirteenth Embodiment

You may form a pattern using IR ink, UV ink, etc. on the upper layer or the lower layer of the translucent protective film 50 of the optical film 100 of 1st Embodiment. The patterns formed by these inks absorb infrared or ultraviolet rays to develop color, so they cannot be seen visually, but can be detected using infrared or ultraviolet rays. Thereby, the pattern of the liquid crystal layer can be detected by the viewer using visible light, and then infrared or ultraviolet rays can be irradiated to detect the pattern formed by IR ink or UV ink, so the detection method can be implemented in two stages. Furthermore, in such a case, the pattern formed by IR ink or UV ink is preferably formed of a material that transmits visible light. A mode in which a pattern using such an IR ink, UV ink, etc. is used can be used in combination not only with the optical film of the first embodiment but also with the optical film of any of the above-mentioned embodiments.

14th Embodiment

The optical film of the present invention is preferable in various applications as described above, but it is preferable to prevent the act of peeling off the optical film once attached to articles such as products and attaching it to other articles, that is, to prevent reuse. An example of the process of manufacturing such a reuse-preventable optical film and transferring the liquid crystal layer of the optical film to an article (transferred object) is shown in FIGS. 14( a ) to ( e ).

The laminate shown in Fig. 14(a) is a laminate obtained in the liquid crystal formation step (Fig. 1(d)) of the process shown in Fig. 1, and the alignment of the liquid crystal layer is made by the alignment film on the substrate. Fixed and patterned. In the first embodiment, the translucent protective film was attached to the laminated body through the adhesive agent, but in the above example, the separator was attached through the paste layer to obtain the ) shows the laminated body. Next, the alignment film attached to the substrate of the laminate was peeled off and removed to obtain a laminate composed of a liquid crystal layer/paste layer/separator as shown in FIG. 14(c). The laminate can be adhered to various useful articles after peeling off the separator sheet, and thus becomes a product form as a transfer sealant. In addition, 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 (the side opposite to the paste layer). Next, the separator sheet is peeled off from the laminated body as shown in FIG. 14( d ), and attached to an article. Thereby, as shown in FIG. 14( e ), the liquid crystal layer can be transferred to the article via the spacer. Furthermore, when a protective film is provided on the surface of the liquid crystal layer of the laminate as shown in FIG. 14( c ), it can be peeled off after the laminate is attached to an article. Here, the liquid crystal layer 30 can be manufactured as an extremely thin film such as 0.3 to 9.0 μm, especially 0.3 to 6.0 μm as described above, so the breaking strength of the liquid crystal layer is lower than the peeling force of the paste layer, and the paste layer is formed. Elastic deformation occurs 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. 14 (a) to (e), as a separator, olefin-based resins such as polyethylene, polypropylene, and 4-methylpentene-1 resin, polyamide, polyimide, Polyamideimide, polyetherimide, polyetherketone, polyetheretherketone, polyethersulfone, polyketonesulfide, polysulfone, polystyrene, polyphenylene sulfide, polyphenylene ether, polyparaphenylene Ethylene dicarboxylate (PET), polybutylene terephthalate, polyarylate, polyacetal, uniaxially stretched polyester, polycarbonate, polyvinyl alcohol, polymethyl methacrylate, polyarylate , amorphous polyolefin, norbornene-based resin, uniaxially stretched polypropylene film (OPP), triacetyl cellulose (TAC), or epoxy resin. As the triacetyl cellulose (TAC), saponified triacetyl 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 adheres to the separator in a detachable manner, any adhesive or bonding agent can be used, and any material requiring post-treatment such as hardening by hot stamping or UV irradiation may be used. In addition, as a separator, the transfer tape to which the paste was adhered and the separator was attached to both sides, for example, 467MP, 9458, 9626 by 3M company etc. can also be used.

15th Embodiment

Modifications of the procedure described in the fourteenth embodiment are shown in Figs. 15(a) to (h) and (h'). The laminate shown in Figure 15(a) is the laminate obtained in the liquid crystal formation step (Figure 1(d)) in the process shown in Figure 1, and the alignment of the liquid crystal layer is fixed by the alignment film on the substrate And form a pattern. On the surface of the liquid crystal layer of such a laminate, an adhesive layer is formed as shown in FIG. 15(b). The adhesive layer is preferably a hot-melt adhesive, or a photocurable or electron beam curable reactive adhesive. For the adhesive layer, any specification that remains or does not remain on the liquid crystal layer after the laminate is finally attached to an article as described below can be selected. Next, as shown in Fig. 15(c), the separator 1 is attached on the adhesive layer. As the separator 1, the same material as the separator used in the fourteenth embodiment can be used. Then, the alignment film attached to the substrate of the laminate was peeled off and removed to obtain a laminate composed of a liquid crystal layer/adhesive layer/separator 1 as shown in FIG. 15( d ). As shown in Figure 15(e), a spacer 2 is attached on the exposed liquid crystal layer of the laminate through a paste layer, thereby obtaining a structure consisting of spacer 2/paste layer/liquid crystal layer/adhesive Laminated body composed of layer/separator sheet 1.

Since the laminate can be attached to various useful articles by peeling off the separator sheet 1 and the separator sheet 2 thereafter, it can be formed into a product form as a sealing material. When attaching the above-mentioned laminate to an article, the separator 2 is peeled off as shown in FIG. 15( g ), and attached to the article through the paste of the laminate. Finally, the separator 1 is peeled off with the adhesive remaining and the form shown in FIG. 15( h ) is obtained. By leaving the adhesive on the outermost surface, it can function as a protective film for the liquid crystal layer and can impart heat resistance or light resistance. In addition, the thickness and strength of the adhesive layer can also be used to peel off after being attached to an article. .

Instead of peeling the separator 1 from the adhesive layer, it is also possible to peel off the separator 1 and the adhesive together so that only the liquid crystal layer remains on the article via the paste layer as shown in FIG. Shape. In this case, the liquid crystal layer 30 can be formed as an extremely thin film of about 1 to 3 μm as described above, so such a thin film cannot be easily peeled off from the article, and the liquid crystal layer itself will be broken if it is forced to peel off. Therefore, the optical film cannot be reused. Make the adhesive layer remain (Figure 15(h)) or make it not remain (Figure 15(h')) by considering the adhesive force of the adhesive layer to the spacer 1 and the adhesive force of the adhesive layer to the liquid crystal layer The relationship is determined by selecting the material of the adhesive layer.

Regarding the spacer 1, spacer 2, paste, and adhesive used in the optical films of the fourteenth and fifteenth embodiments, Japanese Patent Laid-Open No. 2003-121643, Japanese Patent Laid-Open No. 2004-117522, and Japanese Patent Laid-Open No. 2004 -138697 discloses various substances as adhesives or adhesives for releasable substrates and separators, or for adhering them to liquid crystal substances.

Furthermore, Fig. 14(a)-(e) and Fig. 15(a)-(h) and (h') show an example in which an alignment film is used in the same manner as in the first embodiment, but it is also possible to use the substrate itself. Alignment substrate. In such cases, the alignment film may be omitted.

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

For example, the intermediate layer 94 described in the tenth embodiment may be provided so as to cover the printed layer 84 and the upper surface of the liquid crystal layer 30 in the ninth embodiment. In this case, the regions with different alignment states may be provided only in a part of the intermediate layer 94 , and the regions 30 a with different alignment states may not be provided in the liquid crystal layer 30 adjacent to the printed layer 84 . When the regions 30a with different alignment states are not provided in the liquid crystal layer 30, the liquid crystal layer 30 can also be formed using a liquid crystal ink in which small pieces of cholesteric liquid crystal are dispersed in an ink medium, instead of being manufactured by the above-mentioned method.

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

In the description of the second embodiment, it has been described that the lowermost surface (concave-convex pattern 60) of the optical film 102 can further be provided with an adhesive layer such as an adhesive sealant, a release paper, a protective film, a substrate, etc., but for other embodiments In the same way, the optical film can also be provided with an adhesive layer such as a sealant, a release paper, a protective film, a base material, and the like. The support is not limited to plastic films such as TAC or PET, and may be a woven or non-woven fabric such as a fiber label attached to clothes such as shirts.

In any of the optical films of the above embodiments, patterns or designs are formed by the regions 30a and 30b in which the alignment states of the liquid crystal material of the liquid crystal layer are different from each other, but it is also possible to form the regions 30a or 30b as dot patterns or barcodes Patterns, QR codes (registered trademarks) and other patterns or codes are given informational properties. In this way, information such as the product number or the date of manufacture of the optical film itself or the article with the optical film can also be attached.

The shape, size, and thickness of the optical film are arbitrary, and a slit (slit) for preventing replacement of the optical film may be provided in a part of the optical film, and an opening in a donut shape may be formed in the optical film.

As a material constituting each layer of the optical film described in the embodiment, any material can be used as long as the functions of these layers can be exhibited. For example, additives such as pigments or light reflectors for decoration or coloring can be added to the liquid crystal layer or protective film. The liquid crystal material may be composed of not only 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 visually. In order to observe the authenticity of this optical film, it is only necessary to irradiate the optical film with infrared rays and use an infrared sensor to detect the reflected infrared rays. At this time, after the reflected light is converted into linearly polarized light by the λ/4 plate, it can also be received through a polarizing filter that passes the linearly polarized light.

The above-described embodiments are merely examples, and modifications conceived by those skilled in the art can also be added to these embodiments.

Claims (15)

1. a kind of optical film, with liquid crystal layer,

It is the liquid crystal material in a part of region in above-mentioned liquid crystal layer, identical as the liquid crystal material in other regions, and above-mentioned a part of area The liquid crystal material in domain is different from the orientation state of the liquid crystal material in other above-mentioned regions.

2. optical film as described in claim 1, wherein the liquid crystal material in a part of region of above-mentioned liquid crystal layer is not regularly Orientation.

3. optical film as claimed in claim 1 or 2, wherein above-mentioned liquid crystal layer is by the way that liquid crystal material is coated on alignment film Upper and formation continuous film.

4. optical film as claimed any one in claims 1 to 3, wherein above-mentioned liquid crystal material is cholesterol liquid crystal.

5. optical film according to any one of claims 1 to 4, and then have protective film.

6. optical film according to any one of claims 1 to 4, wherein in the surface of above-mentioned liquid crystal layer across paste layer and Has the spacer that can be removed.

7. optical film as claimed in claim 6, wherein in the surface of above-mentioned liquid crystal layer and paste layer opposite side across then Oxidant layer and have other spacers that can be removed.

8. optical film as claimed in claims 6 or 7 is used as transfer foil, and above-mentioned spacer is peeled from aforesaid paste layer And above-mentioned liquid crystal layer is situated between and is attached at article every aforesaid paste layer.

9. such as optical film described in any item of the claim 1 to 8, and then having microlens array.

10. such as optical film described in any item of the claim 1 to 8, and then having convex lens shape lens array.

11. the optical film as described in any one of claims 1 to 10, wherein be formed with performance diffraction energy in above-mentioned liquid crystal layer The region of power.

12. the optical film as described in any one of claim 1 to 11, and then have the layer of performance diffracting power.

13. the optical film as described in any one of claim 1 to 12, wherein have printing layer in the lower layer of above-mentioned liquid crystal layer.

14. the optical film as described in any one of claim 1 to 13, and then have back side component.

15. a kind of article is provided with the optical film described in any one of claim 1 to 14.