JP2547418B2 - Method of manufacturing light control plate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention is a method for manufacturing a light control plate that selectively scatters only incident light from a predetermined angle range and transmits incident light at other angles. It is about.

<Prior Art> Conventionally, as a light control plate that selectively blocks only incident light from a predetermined angle range and transmits incident light at other angles, a plastic transparent sheet and an opaque sheet are alternately laminated. A so-called light-shielding plate has been used in which an alignment film cut out from a block or a photosensitive resin is used to provide reliefs in a lattice or stripes on a transparent substrate, and a transparent substrate or the like is further combined thereon.

An example of this light-shielding plate is disclosed in Japanese Patent Laid-Open No. 189439/1982. However, these conventional alignment films and light-shielding plates have the problems that they are expensive because the manufacturing method is complicated and the film quality is not uniform.

A patent application for a method of manufacturing a light control plate that overcomes the above problems, has a uniform film quality, selectively scatters only incident light from a predetermined angle range, and transmits incident light of other angles , Japanese Patent Application No. 61-302500 (filed on December 18, 1986, "Light control plate and its manufacturing method") and patent application, 1987
It is described in "Light control board and its manufacturing method", filed on June 11, 2012.

That is, a resin composition composed of a photopolymerizable monomer and an oligomer or a photopolymerizable monomer mixture having different refractive indexes is held in a film form, and then the surface is irradiated with ultraviolet rays from a specific direction to be cured. By doing so, it is possible to obtain a light control plate which selectively scatters only incident light from a predetermined angle range with respect to the film and transmits incident light of other angles.

The resulting film-shaped cured product exhibits anisotropy with respect to the major axis and minor axis directions of the ultraviolet light source, and scatters light in a predetermined angle range only when rotated about the major axis direction of the light source.

That is, the film-shaped cured product generated has regions with different refractive indices, which are oriented in a certain direction, and light incident from a predetermined angle range is totally reflected at the boundary of regions with different refractive indices and scattered. It is supposed to do.

The degree of scattering and the angle range of the incident light that is selectively scattered can be adjusted in a wide range by changing the structure of the resin composition used, but even when the same resin composition is used, the ultraviolet light to the cured surface during curing is By varying the angle of incidence, the angular range of incident light that is selectively scattered by the cured film can be varied.

<Problems to be Solved by the Invention> However, in the above-mentioned light control plate, deterioration and yellowing due to ultraviolet rays of a film made of the above resin composition become a problem particularly when used outdoors, during actual use. .

In order to prevent deterioration and yellowing due to ultraviolet rays, it is common to add an ultraviolet absorber or the like to the resin composition, but in the present invention, since it is necessary to cure with ultraviolet rays, an ultraviolet absorber or the like is added. Then, there arises a problem that the curing is hindered.

<Means for Solving Problems> In order to solve the above conventional problems, the present invention is a resin composition comprising a photopolymerizable monomer and an oligomer or a photopolymerizable monomer mixture having different refractive indexes. To
It is held on a colorless or colored UV-resistant transparent layer or substrate, or after being applied to form a film, the UV-resistant transparent layer or substrate is further exposed to UV rays on the opposite side to the surface on which it is installed, By curing the photopolymerizable resin composition, a light control plate that selectively scatters only incident light from a predetermined angle range with respect to the film and transmits incident light at other angles is obtained.

The UV-resistant transparent layer or substrate is a glass plate or a plastic plate or film having a UV-cutting property, which is usually used, and its material depends on the application and the wavelength of the UV light source used for curing. Stipulated.

The photopolymerizable monomer or oligomer used in the present invention is a compound having one or more carbon-carbon double bonds in the molecule, and examples thereof include an acryloyl group, a methacryloyl group, a vinyl group and an allyl group. Is a monomer or oligomer containing at least one polymerizable group.
Any combination may be used as long as it can be polymerized by ultraviolet rays and has a different refractive index and an appropriate compatibility.

Suitable examples include polyester acrylate, polyol polyacrylate, modified polyol polyacrylate, isocyanuric acid skeleton polyacrylate, melamine acrylate, hydantoin skeleton polyacrylate, polybutadiene acrylate, epoxy acrylate, urethane acrylate or bisphenol A diacrylate, 2 Polyfunctional acrylates such as 2,2-bis (4-methacryloxyethoxy-3,5-dibromophenyl) propane and methacrylates corresponding to these acrylates. Alternatively, tetrohydrofurfuryl acrylate, ethyl carbitol acrylate, dicyclopentenyl oxyethyl acrylate, phenyl carbitol acrylate, nonylphenoxyethyl acrylate, 2-hydroxy-3-phenoxypropyl acrylate, ω-hydroxyhexanoyloxyethyl acrylate, acryloyl Oxyethyl succinate, acryloyl oxyethyl succinate, acryloyl oxyethyl phthalate, phenyl acrylate, tribromophenyl acrylate, phenoxyethyl acrylate,
Tribromophenoxyethyl acrylate, benzyl acrylate, p-bromobenzyl acrylate, isobornyl acrylate, 2-ethylhexyl acrylate,
Lauryl acrylate, 2,2,3,3-tetrafluoropropyl acrylate and methacrylates corresponding to these monofunctional acrylates, and styrene, p-chlorostyrene, divinylbenzene, vinyl acetate, acrylonitrile, N-vinylpyrrolidone, vinyl Vinyl compounds such as naphthalene, or diethylene glycol bisallyl carbonate, triallyl isocyanurate,
Examples thereof include allyl compounds such as diallylidene pentaerythritol, diallyl phthalate, and diallyl isophthalate. At least two or more selected from these monomers or oligomers are used as a mixture,
The refractive indexes of those homopolymers must be different from each other, and the larger the difference in the refractive indexes, the higher the haze ratio of the obtained resin. Preferably, the at least two monomers or oligomers have a refractive index difference of at least 0.01, more preferably at least 0.05. The mixing ratio of two kinds of monomers or oligomers having a refractive index difference of at least 0.01 is preferably in the range of 10:90 to 90:10 by weight. The compatibility of these resins is
Somewhat bad is preferable. If the compatibility is good, the resulting resin will be completely uniform and no haze will occur. Also, if the compatibility becomes extremely poor,
Since phase separation occurs before photo-curing, the haze ratio of the obtained resin is excessively reduced, resulting in haze over the entire surface.

Further, as the photopolymerizable initiator, for example, benzophenone, benzyl Michler's ketone, 2-chlorothioxanthone, 2,4-diethylthioxanthone, benzoin ethyl ether, diethoxyacetophenone, benzyl dimethyl ketal, 2-hydroxy-2-methyl. Examples include propiophenone and 1-hydroxycyclohexyl phenyl ketone.

Furthermore, examples of the ultraviolet light source include a rod-shaped mercury lamp and a metal halide lamp.

<Effects of the Invention> According to the present invention, an ultraviolet absorber or the like is not added to the resin composition, and the ultraviolet resistant transparent layer or substrate is placed on the surface opposite to the surface irradiated with ultraviolet rays. Therefore, the light control plate can be manufactured without hindering the curing of the resin composition.

In the light control plate manufactured according to the present invention, deterioration of the film and yellowing of the film can be prevented by using the surface on which the ultraviolet resistant transparent layer or the substrate is installed on the outdoor side.

Furthermore, since the resin composition can be directly held or applied on the ultraviolet resistant transparent layer or the substrate, no special process is required when manufacturing the light control plate, and the resin composition can be manufactured by the conventional process.

<Examples> Hereinafter, the present invention will be described in more detail with reference to Examples.
In addition, the measuring method about each characteristic of the light control plate obtained in the example was performed as follows.

<Measurement of parallel light transmittance haze value> According to JIS K-6714, total light transmittance and scattered light transmittance were measured by an integrating sphere light transmittance measuring device to determine parallel light transmittance and haze value (haze ratio).

<Light resistance> After 500 hours of the sunshine weather meter, the yellowness was measured with a color difference meter, and the difference ΔYI from the initial yellowness was obtained.

Example 1 100 parts of polyether urethane acrylate (refractive index 1.481) obtained by the reaction of polypropylene glycol having an average molecular weight of 2000, toluene diisocyanate and 2-hydroxyethyl acrylate, and 100 parts of tribromophenoxyethyl acrylate (refractive index 1.567); A resin composition containing 6 parts of benzyl dimethyl ketal added and mixed,
As shown in Fig. 1, it is coated on an ultraviolet cut film (manufactured by Nippon Carbite Co., Ltd.) that absorbs ultraviolet rays having a wavelength of 390 nm or less so that the film thickness is 200 μ, and a distance of 50 cm is applied to the film surface. A rod-shaped high-pressure mercury lamp (80w / cm, 2kw, issue diameter 2cm, issue length 50cm, made by Ushio Denki) at an angle of inclination of 50 degrees from the right angle direction is parallel to the UV cut film surface and virtual on the film surface. Was arranged so as to be parallel to the x-axis, and ultraviolet rays were irradiated from the lamp for 1 minute from the coated surface side to obtain a cured sheet. FIG. 5 shows the relationship between the incident angle of light and the haze ratio when the obtained cured sheet was rotated left and right around the x axis and the haze ratio was measured from the z axis direction. However, the angle when the light is perpendicularly incident on the surface is 0 degree.
As can be seen from the measurement results, the obtained cured sheet had a light control function.

Example 2 The same resin composition as in Example 1 was injected into a cell composed of a normal plate glass and an ultraviolet cut glass plate containing 5% by weight of TiO ₂ and a 1 mm thick spacer as shown in FIG. An ordinary glass plate was irradiated toward the irradiation side and cured in the same manner as in Example 1.

Example 3 The same resin composition as in Example 1 was used as shown in FIG.
Acrylic resin plate containing no ultraviolet absorber in the same manner as in Example 1 by injecting into a cell composed of an m-thick spacer, an acrylic resin plate containing no ultraviolet absorber and an acrylic resin plate containing an ultraviolet absorber Was irradiated so as to be on the irradiation side and cured.

Comparative Example 1 The same resin composition as in Example 1 was used as shown in FIG.
Injected into a cell composed of an m-thick spacer and two ordinary glass plates, the same as in Example 1. And cured.

Table 1 shows the results of the light transmittance and the light resistance test of each of the above Examples and Comparative Examples.

[Brief description of drawings]

1 to 3 are side views showing examples of the present invention, and FIG. 4 is a side view showing a comparative example. 1 ... UV lamp, 2 ... UV cut film 3 ... Resin composition, 4 ... UV absorbing glass 5 ... Glass plate 6 ... Acrylic resin plate containing UV absorber 7 ... Acrylic without UV absorber Resin plate 8 ... Spacer

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Satoshi Shiiki 4-chome, Doshomachi, Higashi-ku, Osaka, Osaka Prefecture Japan Sheet Glass Co., Ltd. (72) Inventor Hisato Kabuki 4-chome, Doshomachi, Higashi-ku, Osaka, Japan Japan Ita Glass Co., Ltd. (72) Inventor Motoaki Yoshida 4-8 Doshomachi, Higashi-ku, Osaka City, Osaka Prefecture Japan Ita Glass Co., Ltd. (72) Inventor Shinichiro Kitayama 3-1, 98 Kasuga, Konohana-ku, Osaka City, Osaka Prefecture Sumitomo Chemical Co., Ltd. (72) Inventor Teruho Adachi 3-1,98 Kasugade, Konohana-ku, Osaka City, Osaka Prefecture Sumitomo Chemical Co., Ltd. (72) Inventor, Masahiro Ueda Kasuga, Konohana-ku, Osaka City, Osaka Prefecture 3-1-98 Sumitomo Chemical Co., Ltd. (56) Reference JP 62-70407 (JP, A) JP 60-247515 (JP, A) JP 51 74425 (JP, A)

Claims (1)

(57) [Claims] 1. A resin composition containing at least two kinds of photopolymerizable monomers or oligomers having different refractive indexes is held in a film form, and then the surface of the film is irradiated with ultraviolet rays from a predetermined direction. By curing, selectively scattering only incident light from a predetermined angle range with respect to the film, incident light of other angles are transmitted in the method of manufacturing a light control plate, when irradiating ultraviolet rays A method for producing a light control plate, wherein a colorless or colored UV-resistant transparent layer is provided on the film surface opposite to the irradiation surface.