JP2000258615A - Production of diffusion reflection plate and transfer film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to efficiently produce a diffusion reflection plate used for diffusion reflection of a reflection type LCD, etc., by forming ruggedness on a thin-film layer, photosetting the thin-film layer in apertures by using a photomask to hold a rugged shape, fluidizing the thin-film layer of uncured portions by heating to smooth the layer and forming a reflection film on the surface formed with the thin-film layer. SOLUTION: The thin-film layer 2 is formed on the surface desired to be formed with the ruggedness of a glass substrate 1 and a sandblasted PET film 7 subjected to a processing treatment to a state of the surface having a multiplicity of the fine ruggedness is pressed to the thin-film layer 2. The film is exposed with the photomask 8 formed with the portions desired to hold the ruggedness as the apertures and is heated, by which the smoothed portions are smoothed. As a result, the thin-film layer 2 which has a multiplicity of the fine ruggedness in the desired portions and is smoothed in the required portions is formed at a low cost by the stage simpler than the method of patterning by a photolithography process. If the reflection film 3, such as a metallic thin film, is formed thereon, the diffusion reflection plate is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a reflection type liquid crystal display device which does not require a backlight, a diffused reflection plate used for a solar cell which requires a high efficiency, and the like. Transfer film.

[0002]

2. Description of the Related Art Liquid crystal displays (hereinafter abbreviated as LCDs).
Utilizing features such as thinness, small size, and low power consumption, is currently used for display units such as watches, calculators, TVs, and personal computers. In recent years, color LCDs have been developed and OA / AV
It is beginning to be used for many purposes, such as navigation systems, viewfinders, and personal computer monitors, mainly for equipment, and the market is expected to expand rapidly in the future. In particular, reflective LCDs that perform display by reflecting light incident from the outside are attracting attention as portable terminal equipment because they do not require a backlight, consume less power, and can be made thinner and lighter. ing.

Conventionally, a twisted nematic system and a super twisted nematic system have been adopted for a reflection type LCD, but in these systems, a half of the incident light is not used for display by a linear polarizer, and the display becomes dark. turn into. Therefore, the number of polarizers was reduced to one, and a method combined with a retardation plate or a phase transition type guest
A host display mode has been proposed. Reflective LC
In order to obtain a bright display by efficiently using external light in D, it is necessary to further increase the intensity of light scattered in a direction perpendicular to the display screen with respect to incident light from all angles. Therefore, it is necessary to control the reflection film on the reflection plate so as to obtain appropriate reflection characteristics. A so-called photolithography method (Japanese Patent Laid-Open No. 4-243226) has been proposed in which a photosensitive resin is applied to a substrate and patterned using a photomask to form irregularities, and a metal thin film is formed to form a diffuse reflection plate. Have been.

[0004]

In the above-mentioned method, in order to form irregularities, each substrate is exposed with a photomask,
Since there is a developing step, the step is complicated, and it cannot be said that the cost is low and the productivity is high. In addition, it is difficult to stably produce a diffuse reflection plate having a constant reflection characteristic because the shape of the concavities and convexities easily changes by processes such as development and post-baking.
For the purpose of further improving the reflection characteristics, if it is desired to obtain a diffuse reflection plate having a plurality of uneven heights, the above method requires a plurality of times of application, exposure, and development of a photosensitive resin, so that the process is more complicated. Become. On the other hand, a thin film layer is laminated on a temporary support having an uneven surface on which light can be diffused, and the surface of the thin film layer that is not laminated on the temporary support constitutes an adhesive surface to a transfer substrate. A method was proposed in which a thin film layer was transferred to a substrate using a film, and a reflection film was formed to form a diffuse reflection plate (Japanese Patent Application No. 10-216939). However, in this method, when it is necessary to form a smooth portion in the substrate having the unevenness, it is necessary to remove the thin film layer by development or the like. In particular, when used for a substrate of a reflection type liquid crystal display device, smoothness is required for a peripheral portion of a tab bonding portion. Further, a difference in film thickness occurs between a portion where the thin film layer is removed and an uneven portion formed by the thin film layer, and a defect due to disconnection occurs in a process of laminating a transparent electrode and a process of patterning by etching in a later process. There was a problem.

[0005]

SUMMARY OF THE INVENTION The present invention relates to a method for efficiently producing a diffuse reflector used as a reflective reflector for a reflective LCD having good reflective characteristics, and a transfer film used for the production. To provide.

[0006]

A first method of manufacturing a diffuse reflection plate according to the present invention comprises a step of forming a photocurable resin composition as a thin film layer on the surface of a substrate, and a step of forming an uneven shape capable of diffusing light on the surface. Pressing the prototype on which the surface is formed against the thin film layer to form irregularities on the thin film layer, using a photomask to light cure the thin film layer in the opening to maintain the irregular shape, The method includes a step of flowing and smoothing the thin film layer, and a step of forming a reflective film on the surface on which the thin film layer is formed.

A second method of manufacturing a diffuse reflection plate according to the present invention comprises the steps of laminating a thin film layer on a temporary support having an uneven surface capable of diffusing light on the surface, Laminating the surface that is not laminated to the temporary support, photocuring the thin film layer in the opening using a photomask to maintain the uneven shape, and heating to flow the uncured portion of the thin film layer to smooth it. And forming a reflective film on the surface on which the thin film layer is formed.

The step of smoothing the uncured portion of the thin film layer by heating in the first and second manufacturing methods includes a step of smoothing via a pressurizable plate-like or roll-like pressing body. Is preferred.

In the method for producing a diffuse reflection plate of the present invention, a base film having an uneven surface capable of diffusing light on the surface and a transfer film in which thin film layers are sequentially laminated are used. For the thin film layer, a photocurable resin composition is used, which has a function of flowing and smoothing when heated to a softening temperature or higher before curing. A cover film can be laminated on the thin film layer. Further, a base film, an undercoat layer having a large number of fine irregularities on the surface, and a transfer film in which a thin film layer is sequentially laminated are used. A cover film can be laminated on the thin film layer.

[0010]

According to the method of the present invention for manufacturing a reflection-type LCD diffuser reflector, a thin film layer is formed on a surface of a substrate on which unevenness is to be formed, and a large number of surfaces are formed on the thin film layer. The step of pressing a prototype processed into a state having fine irregularities, the step of exposing with a photomask having an opening at a portion where the irregularities are to be retained, and the step of smoothing a portion smoothed by heating, It is possible to form a thin film layer having a large number of fine irregularities in a desired portion and smoothing a necessary portion in a simpler and lower cost process than in a method of patterning by a lithography method. . If a reflective film such as a metal thin film is further formed thereon, a desired diffuse reflector can be obtained.

A step of laminating a thin film layer on a temporary support which has been processed to have a large number of fine irregularities on the surface;
A step of transferring the thin film layer onto the uneven surface of the substrate, a step of exposing with a photomask having an opening at a portion where the unevenness is desired to be held, and a step of smoothing the portion smoothed by heating. In this method, a thin film layer having a large number of fine irregularities in a desired portion and having a required portion smoothed can be formed with a simpler process at a lower cost than a method of patterning by using the method described above. If a reflective film such as a metal thin film is further formed thereon, a desired diffuse reflector can be obtained.

The temporary support having the uneven surface capable of diffusing light formed on the surface of the transfer film is manufactured by pressing a prototype having the uneven surface capable of diffusing light on the surface. It can also be used. In addition, a base film is provided with a deformable undercoat layer, a step of pressing a prototype having an uneven surface capable of diffusing light on this layer, and a step of curing the undercoat layer instead of the base film. May be used. Further, a base film having a surface subjected to sandblasting can also be used.

An example of a method of manufacturing a prototype or a temporary support having a concave-convex surface capable of diffusing light is disclosed in the document “Optical Disks, Optronics, published in 1990”. That is, after applying a photoresist on a glass plate, exposing and developing using a photomask having a predetermined mask pattern, or after laser cutting, silver or nickel is formed on the pattern forming surface by a vacuum evaporation method, a sputtering method, or the like. A father model can be manufactured by a process of forming a film (conductivity treatment), laminating nickel by electroforming, and separating from a glass plate. The father prototype is subjected to a peeling treatment, nickel electroforming is performed again, and the mother prototype is peeled off from the father prototype to form a mother prototype, and a large number of fine irregularities can be formed using the mother prototype.

A prototype or a temporary support having an irregular surface capable of diffusing light is capable of diffusing light over the entire surface of a substrate, such as a sheet, a flat plate, a roll, or a part of a curved surface, or a necessary portion. It is possible to use a material having a surface having irregularities that can be formed thereon, and it may be used by sticking it to a pressing device or sandwiching it between the surface on which unevenness is formed and the pressing device. Heat, light, or the like may be given in the pressing step.

It is usually necessary to design the degree of unevenness of a prototype or a temporary support on which an uneven surface capable of diffusing light is formed, in consideration of deformation due to curing of a thin film layer.
Assuming that the deformation rate due to the curing of the thin film layer is a, the difference between the height of the concave portion and the height of the convex portion is 0.1 μm or less as the cured shape of the thin film layer.
15 μm, more preferably 0.1 μm to 5 μm, and the pitch of the projections is preferably 0.7 μm or more and 150 μm or the smaller of the pixel pitch, and more preferably 2 μm or more and 150 μm or the smaller of the pixel pitch. . FIG. 5 shows an apparatus for measuring the reflection characteristics of the diffuse reflection plate of the present invention. Assuming that the angle between the reflected light beam 21 and the incident light beam 22 is θ, a diffuse reflector having excellent reflection characteristics can be obtained by increasing the luminance observed in the normal direction of the diffuse reflector, that is, the reflection intensity within the required θ range. can get. When the required range of θ is −60 ° to 60 °, the diffuse reflection plate in which the concave and convex portions are formed with the concave curved surface as shown in FIG.
As shown in the figure, the height H of the concave portion and the convex portion, and the pitch P of the convex portion
Is near the straight line represented by the relational expression of P = 7 × H, a diffuse reflection plate having excellent reflection characteristics can be obtained. Also, θ
Is −15 ° to 15 °, a diffuse reflector having excellent reflection characteristics can be obtained near a straight line represented by the relational expression of P = 30 × H. This means that if one wishes to obtain diffuse reflection with respect to the normal using a light source within a range of 60 degrees and further obtain a strong reflection within a range of 15 degrees, the relational expression of P = 7 × H and P = 30
It indicates that it is only necessary to form a composite shape of the area near two straight lines represented by the relational expression of × H. Of course, it is not limited that all the irregularities are included in the range near the above-mentioned two straight lines. This is because a plurality of shapes are naturally formed in the uneven shape forming process. In addition, it is necessary to consider the uniformity of the gap of the liquid crystal layer and the influence of light interference. Therefore, the degree of unevenness of the temporary support is such that the difference in height between the concave portion and the convex portion on the convex curved surface is 0.1 × a μm to 15 × a μm.
m, further, 0.1 × a μm to 5 × a μm, the pitch of the projections is 0.7 μm or more and 150 μm or the pixel pitch, whichever is smaller, and further 2 μm or more and 150 μm
Alternatively, the pixel pitch is preferably smaller than the smaller one. The value of a differs depending on the material of the thin film layer, and may be, for example, 2 or 1 or 0.7. The above is an example of the case where the unevenness of the diffuse reflection plate is formed by the concave curved surface as shown in FIG. 11. On the other hand, as for the diffuse reflection from the light source within 60 degrees, the relationship between the height H of the concave portion and the convex portion and the pitch P of the convex portion as shown in FIG.
The reflection characteristics are excellent near the straight line represented by the relational expression of = 3.5 × H. The uneven shape does not need to be periodically arranged in the plane, and may be irregular. Also reflective LCD
In the case of, moire occurs when the periodicity different from the pixel pitch is in the uneven shape, the unevenness is the same as the pixel pitch, a period divided by an integer, or an irregular arrangement of irregularities Is preferred. In addition, the surface shape of the unevenness is not particularly limited, but is not only a complex plane but also a concave or convex curved surface, a curved surface of a complex unevenness, and further a concave or convex curved surface approximating a spherical surface or a paraboloid, a curved surface of a complex unevenness. Is preferred. This is because, by making the surface curved, diffuse reflection light from a wider range of light source positions can be expected.

As the base film of the present invention, a film which is chemically and thermally stable and can be formed into a sheet or plate can be used. Specifically, polyethylene, polyolefins such as polypropylene, polyvinyl chloride, polyvinyl halides such as polyvinylidene chloride,
Examples thereof include cellulose derivatives such as cellulose acetate, nitrocellulose, and cellophane, polyamide, polystyrene, polycarbonate, polyimide, polyester, and metals such as aluminum and copper. Among them, particularly preferred is biaxially stretched polyethylene terephthalate having excellent dimensional stability.

As the thin film layer, a resin composition which can be applied on a support and wound up into a film is used. If necessary, dyes, organic pigments, inorganic pigments, powders, and composites thereof may be used alone or in combination. An optical resin composition is used for the thin film layer. The softening temperature of the thin film layer is not particularly limited, but is desirably 200 ° C. or lower. In order to obtain fluidity by heating, a molecular weight of 10
000 or less low melting substances can be added.

Among these, it is preferable to use one having good adhesion to the substrate and good releasability from the base film. For example, as the organic polymer contained in the photocurable resin composition, acrylic resin, polyethylene, polyolefins such as polypropylene, polyvinyl chloride, polyvinyl halides such as polyvinylidene chloride,
Cellulose derivatives such as cellulose acetate, nitrocellulose and cellophane, polyamide, polystyrene, polycarbonate, polyester and the like can be used.
When used for a TFT liquid crystal display device, the T
In order to form a contact hole with the FT, a photosensitive resin that can be developed with an alkali or the like can be used so that the thin film layer at that portion can be removed. Further, in order to improve heat resistance, solvent resistance and shape stability, a resin composition curable by heat can be used. Further, by adding a coupling agent and an adhesion-imparting agent, the adhesion to the substrate can be improved. This includes applying an adhesion-imparting agent to the adhesion surface of the substrate or the thin film layer for the purpose of improving the adhesion.

A low-melting substance having a molecular weight of 10,000 or less is added in order to obtain fluidity by heating the thin film layer. For example, "Plastics Compounding Agent" (Akinori Endo, Makoto Sudo,
The plasticizer described in Taiseisha, issued on November 30, 1996) and a monomer having at least one ethylenic double bond in the molecule are added. The use amount of this component is preferably 1 to 70% by weight of the total solid content in the photosensitive composition.

For example, trimethylolpropane triacrylate, trimethylolpropane diacrylate, triethylene glycol diacrylate, diethylene glycol diacrylate, tetraethylene glycol diacrylate, hexamethylene glycol diacrylate, neopentyl glycol diacrylate, furfuryl acrylate, tetrafuryl acrylate Methylol methane tetraacrylate, resorcinol diacrylate, p, p'-dihydroxydiphenyl diacrylate, spiro glycol diacrylate, cyclohexane dimethylol diacrylate, bisphenol A diacrylate, polypropylene glycol diacrylate, pentaerythritol tetraacrylate, ethylene glycolated pentaerythritol Tetraa Examples thereof include polyfunctional monomers such as acrylate, dipentaerythritol hexaacrylate, and compounds having the same structure as the above methacrylate, methylene bisacrylamide, and urethane diacrylate. Also, ECH-modified phthalic acid diacrylate, tris (acryloxyethyl) isocyanurate, tris (methacryloxyethyl) isocyanurate, tris (2-hydroxyethyl) isocyanurate, polyethylene glycol dimethacrylate, tribromophenyl acrylate, EO-modified triacrylate Bromophenol acrylate, EO
Monomers and oligomers having a solid or viscosity of 100,000 cps or more at 25 ° C. such as modified tetrabromobisphenol dimethacrylate may be used. Further, it is preferably selected from those described in "List of photosensitive materials" (edited by Photopolymer Society, published by Bunshin Publishing, issued on March 31, 1996).

Further, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, 2-ethylhexyl methacrylate, alkyl methacrylate, cyclohexyl methacrylate, tetrahydrofurfuryl methacrylate, benzyl methacrylate, mono (2-methacryloyloxyethyl) acid phosphate, dimethyl methacrylate Monofunctional monomers such as quaternary aminoethyl methacrylate are exemplified.
These components can be used alone or in combination of two or more.

As the photoinitiator of the photocurable resin composition,
For example, benzophenone, N, N'-tetraethyl-
4,4'-diaminobenzophenone, 4-methoxy-
4'-dimethylaminobenzophenone, benzyl, 2,
2-diethoxyacetophenone, benzoin, benzoin methyl ether, benzoin isobutyl ether, benzyldimethyl ketal, α-hydroxyisobutylphenone, thioxanthone, 2-chlorothioxanthone,
1-hydroxycyclohexylphenyl ketone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-1-propane, t-butylanthraquinone,
-Chloroanthraquinone, 2,3-dichloroanthraquinone, 3-chloro-2-methylanthraquinone, 2-ethylanthraquinone, 1,4-naphthoquinone, 9,10
-Phenanthraquinone, 1,2-benzoanthraquinone rati 1,4-dimethylanthraquinone, 2-phenylanthraquinone, 2- (o-chlorophenyl) -4,5-
And diphenylimidazole dimer. These photoinitiators are used alone or in combination of two or more. The amount of this component to be used is preferably 0.01 to 25% by weight, more preferably 1 to 20% by weight, based on the total solid content in the photosensitive composition of the present invention.

The undercoat layer of the present invention is preferably harder than the thin film layer after the formation of the irregularities. For example, polyolefins such as polyethylene and polypropylene, ethylene and vinyl acetate, ethylene and acrylate, ethylene copolymers such as ethylene and vinyl alcohol, polyvinyl chloride, copolymers of vinyl chloride and vinyl acetate, vinyl chloride and vinyl alcohol Copolymers, polyvinylidene chloride, polystyrene, styrene copolymers such as styrene and (meth) acrylate, polyvinyl toluene,
Vinyl toluene copolymer such as vinyl toluene and (meth) acrylate, poly (meth) acrylate, copolymer of butyl (meth) acrylate and (meth) acrylate such as vinyl acetate, synthesis At least one or more organic polymers selected from rubber, cellulose derivatives, and the like can be used. A photoinitiator, a monomer having an ethylenic double bond, or the like can be added, if necessary, for curing after forming the unevenness. Although the photosensitive type is shown using a negative type material, there is no problem even if it is a positive type.

The coating method of the thin film layer and the undercoat layer of the present invention includes roll coater coating, spin coater coating, spray coating, dip coater coating, curtain flow coater coating, wire bar coater coating, gravure coater coating, air knife coater coating and the like. is there. The thin film layer or the undercoat layer composition is applied on a temporary support or the like by the above method.

The material for the reflection film may be appropriately selected according to the wavelength region to be reflected.
In the display device, the visible light wavelength range from 300 nm to 8 nm
A metal having a high reflectance at 00 nm, such as aluminum, gold, or silver, is formed by a vacuum evaporation method, a sputtering method, or the like. Further, a reflection increasing film (Optical Overview 2, Junpei Tsujiuchi, Asakura Shoten, issued in 1976) may be laminated by the above method. The thickness of the reflective film is 0.01 μm to 50 μm.
m is preferred. The reflection film may be formed in a pattern only by a photolithography method, a mask evaporation method, or the like at a necessary portion.

It is desirable that the cover film of the transfer film of the present invention is chemically and thermally stable and easily peelable from the thin film layer. Specifically, polyethylene,
It is preferable to use a thin sheet made of polypropylene, polyethylene terephthalate, polyvinyl alcohol or the like and having a high surface smoothness. It also includes those whose surface has been subjected to release treatment to impart releasability.

As a method of transferring the thin film layer on the temporary support (base film, base film provided with an undercoat layer) to the substrate, there is a method in which the cover film is peeled off, and the substrate is heated and pressed on the substrate. When further adhesiveness is required, a method of cleaning the substrate with a necessary chemical solution, applying an adhesion-imparting agent to the substrate, or irradiating the substrate with ultraviolet rays or the like may be used. As a device for laminating the transfer film of the present invention, a roll laminator that sandwiches a substrate between a rubber roll that can be heated and pressurized and a base film, rotates the roll, and feeds the substrate while pressing the transfer film against the substrate is used. Is preferred. The thickness of the thin film layer formed on the substrate surface in this manner is 0.1 μm to 50 μm.
Is preferable. At this time, when the thickness of the thin film layer is thicker than the maximum height difference of the uneven shape, the uneven shape is easily reproduced. If the film thicknesses are equal or thin, the thin film layer is pierced by the protruding portions of the prototype, and unnecessary flat portions are generated, making it difficult to efficiently obtain diffuse reflection.

In order to maintain a shape capable of diffusing light,
The thin film layer is exposed through a mask to cure the photosensitive portion. Exposure machines applicable to the present invention include a carbon arc lamp, an ultra-high pressure mercury lamp, a high pressure mercury lamp, a xenon lamp,
Examples include a metal halide lamp, a fluorescent lamp, and a tungsten lamp. The exposure is performed before or after the temporary support is peeled off.

After the exposure, in order to smooth the unexposed portion, heating is performed in a hot air heating furnace, an infrared heating furnace, a hot plate or the like. In addition, in order to achieve smoothing more efficiently, a roll-shaped or plate-shaped press device capable of heating and pressing can be used. It is preferable to use a roll laminator that rotates the roll and feeds the substrate while pressing the roll directly or via a smooth sheet on the substrate.

The reflection type LCD display device has been described above.
The diffuse reflection plate of the present invention can be used for a device that needs to diffusely reflect an external light beam. For example, there is a diffuse reflector for improving the efficiency of a solar cell.

[0031]

EXAMPLE 1 As shown in FIG. 1, the following thin film layer forming solution was spin-coated on a glass substrate 1 and then dried to form a 3 μm thin film layer 2. Next, a polyethylene terephthalate film sandblasted on the surface (manufactured by Teijin Limited, 50 μm thick, the difference in height between the concave and convex portions is 0.8 μm, and the pitch between the convex portions is 20 μm).
m) so as to be in contact with the thin film layer 2 (roll laminator HLM1500, manufactured by Hitachi Chemical Technoplant)
Is laminated at a substrate temperature of 100 ° C., a roll temperature of 100 ° C., a roll pressure of 6 kg / square cm, and a speed of 0.5 m / min to form a glass substrate, a thin film layer, and a substrate on which a polyethylene terephthalate film (PET film) is laminated. Obtained. When the PET film was peeled off from this substrate, the sandblasted irregularities were transferred onto the thin film layer,
The uneven shape was excellent in light diffusivity. Light beam that cures a thin film layer on a substrate through a photomask (high-pressure mercury lamp)
Was exposed to 100 mJ / cm using a parallel light exposure machine MAP1200L (manufactured by Dainippon Screen). This board is
40 ° C, 20 minutes oven (clean oven CSO-
402, manufactured by Kusumoto Kasei Co., Ltd.) and cooled to room temperature, the light diffusivity of the exposed portion was maintained and the unexposed portion became smooth. The average height difference of the unevenness of the exposed portion was 1.2 μm, and the average height difference of the unevenness after smoothing the unexposed portion was 0.1 μm or less. An Al thin film was laminated thereon to a thickness of 0.1 μm by a sputtering method to form a reflection film 3. The resulting diffuse reflector was excellent in reflection characteristics and could be used as a diffuse reflector for a reflective LCD. FIG. 2 shows that the present diffuse reflector is a single polarizer type STN.
This shows an example used for a reflective LCD. Thin film layer forming solution: Styrene, methyl methacrylate, ethyl acrylate, acrylic acid, glycidyl methacrylate copolymer resin was used as a polymer (polymer A). The molecular weight is about 35,000 and the acid value is 110. Parts are parts by weight (the same applies hereinafter). (Polymer) Polymer A 50 parts (Monomer) Pentaerythritol tetraacrylate 50 parts (Photoinitiator) Irgacure 369 (Chiba Specialty Chemicals) 2.2 parts N, N-tetraethyl-4,4'-diaminobenzophenone 2.2 Parts (solvent) Propylene glycol monomethyl ether 492 parts (polymerization inhibitor) p-methoxyphenol 0.1 part (surfactant) Perfluoroalkyl alkoxylate 0.01 part

Example 2 A 50 μm thick sand blasted polyethylene terephthalate was used for the base film 4 using the same thin film layer forming solution as in Example 1, and a 6 μm film thickness was formed on this film by a comma coater. Then, a thin film layer 2 was formed, and a polyethylene film was coated as a cover film 5 to obtain a transfer film as shown in FIG.
Next, while peeling off the cover film of the transfer film, a laminator (roll laminator HLM 1500, manufactured by Hitachi Chemical Technoplant Co., Ltd.) was used so that the thin film layer was in contact with the glass substrate.
Lamination was performed at 0 ° C., a roll pressure of 6 kg / square cm, and a speed of 0.5 m / min to obtain a substrate on which a glass substrate, a thin film layer, and a polyethylene terephthalate film (PET film) were laminated. After irradiating the thin film layer with a light beam that reacts at 500 mJ / square cm by an exposure device (large manual exposure device, MAP1200, manufactured by Dainippon Screen Co., Ltd.) through a photomask, and peeling off the PET film from this substrate,
Sandblasted irregularities were transferred onto the thin film layer, and the irregularities were excellent in light diffusivity. Oven at 240 ° C for 20 minutes (Clean Oven CS
(O-402, manufactured by Kusumoto Kasei Co., Ltd.), and when cooled to room temperature, the light diffusivity of the exposed portion was maintained and the unexposed portion became smooth. The average height difference of the unevenness of the exposed portion of this substrate was 1.2 μm, and the average height difference of the unevenness after smoothing the unexposed portion was 0.1 μm or less. An Al thin film was laminated thereon to a thickness of 0.1 μm by a sputtering method to form a reflection film 3. FIG. 4 shows the incident angle dependence of the reflection intensity (relative intensity to the standard white plate) of the diffuse reflection plate manufactured in Example 2 (when the azimuth angle (φ) is fixed). Sufficient reflection intensity was obtained in the range of the incident angle of −60 ° to 60 °, and a diffuse reflection plate having excellent reflection characteristics was obtained.

Example 3 A transfer film was laminated on a glass substrate under the same conditions as in Example 2, and after exposing, the sandblasted PET was peeled off to obtain a thin film layer in which unevenness subjected to sandblasting was transferred over the entire surface. Next, a laminator (roll laminator H) is used so that the smooth PET film faces the thin film layer of the glass substrate.
Using LM 1500 (manufactured by Hitachi Chemical Technoplant), lamination was performed at a substrate temperature of 100 ° C., a roll temperature of 100 ° C., a roll pressure of 6 kg / cm 2, and a speed of 0.5 m / min. When the PET film was peeled off after cooling to room temperature, the light diffusivity of the exposed portion was maintained and the unexposed portion became smooth. The average height difference of the unevenness of the exposed portion of this substrate is 1.2 μm.
m, and the average height difference of the unevenness after smoothing the unexposed portion was 0.1 μm. An Al thin film was laminated thereon to a thickness of 0.1 μm by a sputtering method to form a reflection film 3.

[0034]

According to the method of the present invention for producing a diffuse reflection plate for a reflection type liquid crystal display device or the like, a diffuse reflection plate having good reflection characteristics can be efficiently produced, and the irregularities of the prototype are appropriately set in advance. By doing so, it is possible to freely control the reflection characteristics of the diffuse reflection plate, and to be able to pattern a smooth portion on the uneven formation substrate without a step of removing the thin film layer by development or the like, and to obtain a smooth portion. Since the thin film layer is not removed, a diffuse reflector having a small difference in film thickness between the uneven portion and the smooth portion can be manufactured.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a production example of a diffuse reflection plate of the present invention.

FIG. 2 is a cross-sectional view of a reflective LCD.

FIG. 3 is a cross-sectional view illustrating an example of the transfer film of the present invention.

FIG. 4 is a diagram illustrating the incident angle dependence of the reflection characteristics of the diffuse reflection plate according to the second embodiment of the present invention.

FIG. 5 is an apparatus diagram for measuring the reflected light characteristics of the diffuse reflection plate of the present invention.

FIG. 6 is a cross-sectional view illustrating an example of a diffuse reflection plate manufactured using the transfer film of the present invention.

FIG. 7 is a diagram showing the relationship between the angle formed by the light source and the front of the diffuse reflection plate shown in FIG. 6 of the present invention, the difference between the heights of the uneven portions, and the pitch of the convex portions.

FIG. 8 is a sectional view showing an example of a diffuse reflection plate manufactured using the transfer film of the present invention.

9 is a graph showing the relationship between the angle formed by the light source and the front of the diffuse reflection plate shown in FIG. 8 of the present invention, the difference between the heights of the uneven portions, and the pitch of the convex portions.

[Explanation of symbols]

 1. Glass substrate 2. 2. Thin film layer Reflective film 4. Base film 5. Cover film 6. Undercoat layer 11. Color filter 12. Black matrix 13. Transparent electrode 14. Flattening film 15. Alignment film 16. Liquid crystal layer 17. Spacer 18. Retardation film 19. Polarizing plate 20. Sample 21. Reflected light 22. Incident light ray 23. Luminance meter

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01L 31/04 H01L 31/04 M (72) Inventor Yasuo Tsuruoka 48 Wadai, Tsukuba-shi, Ibaraki Pref. Hitachi Chemical Co., Ltd. Inside the Tsukuba Development Laboratories (72) Inventor Keiko Kizawa 48 Wadai, Tsukuba, Ibaraki Pref.Hitachi Chemical Co., Ltd. FA08Z FA11X FA14Y FA16Y FA31Z FA35Y FB02 FB04 FC01 FC02 FC10 FC22 FD06 GA12 5F051 BA13 BA16 HA20 JA14

Claims (4)

[Claims] 1. A step of forming a thin film layer of a photocurable resin composition on a substrate, a step of pressing a mold having an uneven surface capable of diffusing light on the thin film layer, and masking the thin film layer. A method of manufacturing a diffuse reflection plate, comprising: exposing; heat-treating the substrate to smooth the unevenness of the unexposed thin film layer; and forming a reflective film on the thin film layer. 2. A thin film layer is laminated on a temporary support having an uneven surface capable of diffusing light, and the surface of the thin film layer which is not laminated on the temporary support is bonded to a substrate to be transferred. A transfer film constituting a surface, wherein the thin film layer is a photocurable resin composition, and has a function of flowing and smoothing when heated at a softening temperature or higher. 3. A step of bonding the surface of the substrate to which the thin film layer of the transfer film according to claim 2 is adhered to a substrate to be transferred, a step of subjecting the thin film layer to mask exposure, and a step of subjecting the substrate to heat treatment. A method for manufacturing a diffuse reflector, comprising: a step of smoothing an uneven shape of a thin film layer in an exposed portion; 4. The method according to claim 1, wherein the step of smoothing the unexposed portion of the thin film layer includes a pressing step.