JP2717304B2 - Manufacturing method of light control plate - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light control plate that selectively scatters incident light in various angle ranges and a method for manufacturing the same.

<Prior Art> Conventionally, only a transparent body made of plastic or glass was transparent to light from any angle. Therefore, as a material that transmits only light from a specific angle, an alignment film cut out from a plastic block in which a transparent sheet of plastic and an opaque sheet are alternately laminated, or a lattice or stripe on a transparent substrate using a photosensitive resin In general, a so-called "light-shielding plate" in which a relief having a pattern of "1" is provided and a transparent substrate or the like is further combined thereon is used. As this light shielding plate, for example, there is one disclosed in Japanese Patent Application Laid-Open No. 57-189439.

<Problems to be Solved by the Invention> The above-mentioned conventional alignment films and light-shielding plates have a problem that they are expensive due to the complicated manufacturing method thereof and that the film quality is not uniform.

<Means for Solving the Problems> The present invention relates to a method for manufacturing a light control plate which is a plastic sheet and selectively scatters incident light in a specific angle range with respect to the sheet. A resin composition comprising a plurality of compounds having one or more polymerizable carbon-carbon double bonds in a certain molecule was maintained in the form of a film, and the surface of the film was tightly coated with a transparent film or sheet. Thereafter, the present invention provides a method for manufacturing a light control plate, wherein the resin composition is cured by irradiating ultraviolet rays from above the covering sheet or film.

Here, the polymerizable carbon used in the method of the present invention-
The compound having a carbon double bond is a monomer or oligomer having one or more polymerizable groups such as an acryloyl group, a methacryloyl group, a vinyl group and an allyl group in a molecule. For example, polyester acrylate, polyol polyacrylate, modified polyol polyacrylate, polyacrylate with isocyanuric acid skeleton, melamine acrylate, polyacrylate with hydantoin skeleton,
Polybutadiene acrylate, epoxy acrylate,
Multifunctional acrylates such as urethane acrylate,
Methacrylates corresponding to these acrylates, tetrahydrofurfuryl acrylate, ethyl carbitol acrylate, dicyclopentenyloxyethyl acrylate, phenyl carbitol acrylate, nonylphenoxyethyl acrylate, 2-hydroxy-
3-phenoxypropyl acrylate, ω-hydroxyhexanoyloxyethyl acrylate, acryloyloxyethyl succinate, acryloyloxyethyl phthalate, tribromophenoxyethyl acrylate, isobornyl acrylate, 2-ethylhexyl acrylate, lauryl acrylate, 2,2,3 , 3-tetrafluoropropyl acrylate and the methacrylates corresponding to these monofunctional acrylates, and N
-Vinylpyrrolidone, triallyl isocyanurate, diethylene glycol bisallyl carbonate, dialylidene pentaerythritol and the like.

 These compounds are used as a mixture.

The resin composition used in the present invention is characterized by the mutual solubility of a plurality of compounds constituting the resin and the difference in the refractive index between the compounds. The degree of scattering is increased, and the angle range of the scattered incident light is widened.

In the resin composition of the present invention, a photopolymerization initiator is used as necessary.

Examples of the photopolymerization initiator used as required include benzophenone, benzyl, Michler's ketone,
-Chlorothioxanthone, 2,4-diethylthioxanthone, benzoin ethyl ether, diethoxyacetophenone, benzyldimethyl ketal, 2-hydroxy-2
-Methylpropiophenone, 1-hydroxycyclohexylphenyl ketone and the like.

The present invention is to produce a light control plate by curing the resin composition with ultraviolet light, at the time of the production, the resin composition is formed into a film by, for example, coating on a substrate, and the surface of the film is formed. The present invention relates to a method for manufacturing a light control plate, which comprises applying a UV light from above the coated sheet or film to harden the resin composition after tightly coating with a transparent film or sheet.

The cured product obtained by applying the resin composition used in the present invention on a substrate, forming a film, and irradiating the surface with ultraviolet light without tightly coating the surface with a transparent film or sheet is entirely light. Although it has a control function, a thin layer is formed on its surface where the light control function does not appear, or even if it expresses it very little. Therefore, when trying to obtain a high-performance light control plate, its thickness is limited and cannot be arbitrarily reduced. The thickness of the region where the light control function is not expressed varies depending on conditions and is not necessarily constant, but for example, the depth from the surface is about 50%.
It is up to about μm.

By using the method for manufacturing a light control plate of the present invention, a light control function can be developed from the vicinity of the surface. Therefore, for example, a cured product having a light control function even if the cured product is thinner than about 50 μm can be obtained. Can be.

The transparent film or sheet used in the method of the present invention is a transparent film or sheet that does not hinder curing by irradiation with ultraviolet light, and can be produced by a known method using a known raw material.

For example, polyethylene, polypropylene, ethylene-
Propylene copolymer, ethylene-butene copolymer, ethylene-α olefin copolymer, propylene-butene copolymer, polystyrene, polymethyl methacrylate, methyl methacrylate-styrene copolymer, various styrene copolymers, various methyl Transparent films or sheets of methacrylate copolymer, polyvinyl chloride, various vinyl chloride copolymers, polyvinylidene chloride, polyethylene terephthalate, various polyester polymers, polycarbonate, polyamide and the like can be used.

Although the thickness of these transparent films or sheets is not particularly limited, for example, those having a thickness of 5 to 50 μm can be used.

In the method of the present invention, the transparent film or sheet coated with the cured product can be put to practical use without exfoliation after curing of the resin composition, or can be used after exfoliation. When exfoliation is eliminated, it is desirable that the transparent film or sheet to be coated is made of a material that is easily exfoliated from the light control plate obtained in the present invention, and for example, various kinds of polyethylene or polytetrafluoroethylene can be used.

Ultraviolet rays are irradiated using a mercury lamp or metal halide lamp.When a rod-shaped lamp is used, by adjusting the irradiation conditions, the resulting sheet-shaped cured product can be irradiated in the long axis and short axis directions of the light source. It shows anisotropy, and scatters light at a specific angle only when rotated about the long axis direction of the light source.

That is, the formed sheet-shaped cured product has regions with different refractive indices oriented in a certain direction, and light incident from a specific angle is totally reflected and scattered at the boundary between the regions with different refractive indices. It is considered something.

The degree of scattering and the angle of the incident light that is selectively scattered can be adjusted depending on the resin composition used and the irradiation conditions, and in particular, by changing the angle of incidence of ultraviolet light on the cured sample surface during curing, the cured sheet can be adjusted. The angle of the incident light that is selectively scattered can be changed.

<Effects of the Invention> The method for manufacturing a light control plate of the present invention can relatively easily realize selective scattering by a transparent member angle and transmission only at a specific angle, which were not possible conventionally, and a thin film can be formed. This has the effect of reducing weight and reducing raw material costs.

Although the light control plate of the present invention is a plastic sheet, it can be used in combination with a glass plate or the like. Using these materials, applications to various fields such as window materials, vehicles, displays, mirrors, display panels, and greenhouses can be expected.

<Examples> Hereinafter, the present invention will be described in more detail with reference to Examples,
The present invention is not limited to these examples.

Example 1 Polypropylene glycol having an average molecular weight of 2000 and toluene
Diisocyanate and 2-hydroxyethyl acryle
Polyether urethane acryle obtained by the reaction of
To 50 parts by weight (refractive index: 1.481)
50 parts by weight of the compound represented by (I) (refractive index 1.567)And 2-hydroxy-2-methyl-propiophenone
A resin composition mixed with 3 parts by weight of the resin composition
m, and coat the surface with 25 μm thick transparent polyethylene.
Renfilm (Sumikasen F221: Sumitomo Chemical Co., Ltd.
).

Next, using a mercury lamp of 80 W / cm and a lamp length of 40 cm (lamp: HO45-L31, device: UBO452-3B, manufactured by Eye Graphics Co., Ltd.), irradiate with ultraviolet light for 1 minute at a lamp distance of 40 cm and cure. I got a sheet.

Example 2 The same resin composition as in Example 1 was applied on a glass plate so as to have a thickness of 60 μm, and the surface thereof was adhered with a 10 μm-thick transparent polyvinylidene chloride film (manufactured by Kureha Chemical Industry Co., Ltd.). In the same manner as in Example 1, UV irradiation was performed to obtain a cured sheet.

Comparative Example A cured sheet was obtained by applying the same resin composition as in Example 1 on a glass plate so as to have a thickness of 60 μm and irradiating with ultraviolet light under the same conditions as in Example 1 except that a transparent film was not used. Was.

(Measurement of haze value) The angle dependency of the haze value of the cured sheets obtained in Examples and Comparative Examples was evaluated by the following method.

The total light transmittance and the scattered light transmittance of the cured sheets obtained in Examples 1 and 2 were measured by an integrating sphere light transmittance measuring device according to JISK-6714, and the haze value was obtained.

The test piece was tilted as shown in FIG. 2 and the above value was calculated for each angle.

The angle dependence of the haze values of the cured sheets of Examples 1 and 2 and Comparative Example are represented by and in FIG. 1, respectively.

In addition, in Example 1, the coating film was peeled off, and in Example 2, the measured value was in a state where the coating film was adhered without peeling.

[Brief description of the drawings]

FIG. 1 shows the angle dependence of the haze of the cured sheets obtained in Examples and Comparative Examples. Example 1 Example 2 Comparative Example FIG. 2 shows a method of measuring haze. ...... Light control board

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Noboru Shiragami 6th Kitahara, Tsukuba, Ibaraki Prefecture Within Sumitomo Chemical Co., Ltd. (72) Inventor Masahiro Ueda 2-10-1 Tsukahara, Takatsuki-shi, Osaka Sumitomo Chemical Co., Ltd. (72) Inventor Tetsuro Ohno 2-10-1, Tsukahara, Takatsuki-shi, Osaka Sumitomo Chemical Industries, Ltd. (72) Inventor Kazumitsu Kawamura 2-1-1, Tsukahara, Takatsuki-shi, Osaka Sumitomo Chemical Industries, Ltd.

Claims (1)

(57) [Claims] 1. A method for producing a light control plate which selectively scatters incident light in a specific angle range with respect to the sheet, wherein at least one of the molecules has a difference in refractive index between molecules. A resin composition comprising a plurality of compounds having a polymerizable carbon-carbon double bond is maintained in the form of a film, and the surface of the film is tightly coated with a transparent film or sheet. And vulcanizing the resin composition by irradiating the resin composition with ultraviolet rays.