JPH069714A - Photopolymerizable composition and production of light control board - Google Patents

Abstract

PURPOSE:To obtain a photopolymerizable composition for use in producing a light control board which selectively scatters light rays incident thereon at angles in a specific range by using a combination of a radical-polymerizable compound and a cationically polymerizable compound having a vinyl ether structure as a functional group. CONSTITUTION:The composition comprises a combination of at least two polymerizable compounds having different refractive indexes, the compounds being a radical-polymerizable compound (a) and a cationically polymerizable compound (b) having a vinyl ether structure as a functional group. Examples of the compound (a) include tetrahydrofurfuryl acrylate, ethyl carbitol acrylate, and N-vinylpyrrolidone. Examples of the compound (b) include methyl vinyl ether, propyl vinyl ether, and vinyl cyclohexyl ether.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photopolymerizable composition for a light control plate which selectively scatters only incident light from a specific angle range and a method for producing the light control plate.

[0002]

2. Description of the Related Art Conventionally, transparent bodies made of plastic or glass have been transparent to light from any angle. Therefore, to transmit only light from a specific angle, an alignment film cut out from a plastic block obtained by alternately laminating transparent sheets and opaque sheets of plastic, or a grid or a grid on a transparent substrate using a photosensitive resin. A so-called "light-shielding plate" is generally used in which a relief having a pattern such as stripes is provided and a transparent substrate or the like is further combined thereon. As this shading plate, for example, Japanese Patent Laid-Open No. 57-57
There is one disclosed in Japanese Patent Publication No. 189439. Further, in JP-A-63-309902, a radically polymerizable compound having a difference in refractive index is cured under a specific ultraviolet curing condition, so that only incident light from a specific angle is scattered very easily. A manufacturing method for obtaining a light control plate having a uniform film quality has been proposed.

[0003]

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. Further, it has been desired to widen the opaque angle width in the light control plate.

[0004]

That is, the present invention is a photopolymerizable composition containing two or more polymerizable compounds having different refractive indexes, wherein the radically polymerizable compound and vinyl ether are used as the polymerizable compounds. The present invention relates to a photopolymerizable composition for a light control plate, which is characterized in that a cationically polymerizable compound having a functional group is used in combination. Further, the present invention, the photopolymerizable resin composition containing two or more polymerizable compounds having different refractive index is irradiated with ultraviolet rays from a specific direction to be cured to selectively scatter only incident light in a specific angle range. In the method for producing a light control plate, the radical polymerization mechanism and the cationic polymerization mechanism are used together by using a composition containing a radical polymerizable compound and a cationic polymerizable compound having a vinyl ether as a functional group as the photopolymerizable composition. And a method of manufacturing a light control plate.

The present invention will be described in detail below. The photopolymerizable composition used in the present invention includes a monomer (A) having two or more kinds of polymerizable double bonds having different refractive indexes and /
Or the combination of (B) oligomers can be mentioned. In these combinations, one or more kinds of radically polymerizable compounds and another one or more kinds of cationically polymerizable compounds having vinyl ether as a functional group are prepared to prepare a photopolymerizable composition in which both are mixed to prepare a photoradical polymerization initiator. And photocationic polymerization initiator are used together to perform photopolymerization.

Of the monomers (A), specific examples of radically polymerizable compounds include tetrahydrofurfuryl acrylate, ethyl carbitol acrylate, dicyclopentenyl oxyethyl acrylate, phenyl carbitol acrylate, nonylphenoxyethyl acrylate, and 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, triethylene glycol diacrylate, bisphenol A diethoxydiacrylate and the methacrylates corresponding to these acrylates, and N-vinylpyrrolidone, N- Acryloyl morpholine etc. are mentioned. These monomers can be used alone or in a mixture.

Specific examples of the cationic polymerizable compound having vinyl ether as a functional group among the monomers (A) include methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether, isobutyl vinyl ether, octadecyl vinyl ether, vinyl cyclohexyl ether, butanediol divinyl ether. , Triethylene glycol divinyl ether, bisphenol A diethoxydivinyl ether, bisphenol S diethoxydivinyl ether, hydroquinone diethoxydivinyl ether, resorcin diethoxydivinyl ether and the like. These monomers can be used alone or in a mixture.

Among the oligomer (B), examples of the radically polymerizable compound include polyol polyacrylate, modified polyol polyacrylate, polyacrylate having isocyanuric acid skeleton, melamine acrylate, polyacrylate having hydantoin skeleton, polybutadiene acrylate, epoxy acrylate, urethane. Examples thereof include acrylates and polyester acrylates such as caprolactone-modified polyacrylates. These oligomers can be used alone or as a mixture, like the monomer (A).

Among the oligomers (B), specific examples of the cationically polymerizable compound having vinyl ether as a functional group include urethane vinyl ether (vinyl ether urethane) and ester vinyl ether. These oligomers can be used alone or as a mixture.

In the photopolymerizable composition of the present invention, a radical polymerizable compound as the monomer (A), a vinyl ether oligomer as the oligomer (B), or a vinyl ether monomer as the monomer (A) and a radical polymerizable compound as the oligomer (B). It is preferred to use a combination of compounds.

A photopolymerization initiator is used in the composition of the present invention. A radical polymerization type and a cationic polymerization type are used together as the photopolymerization initiator. As a photo radical polymerization initiator, for example, benzophenone, benzyl, Michler's ketone, 2-chlorothioxanthone, 2,4-diethylthioxanthone, benzoin ethyl ether, diethoxyacetophenone, benzyl dimethyl ketal, 2-hydroxy-2-methylpropiophenone, 1- Examples thereof include hydroxycyclohexyl phenyl ketone. Furthermore, examples of the cationic photopolymerization initiator include aromatic diazonium salts, aromatic sulfonium salts, aromatic iodonium salts, metallocene compounds, silicon compounds / aluminum complexes, and the like. The mixing ratio of the radical polymerization initiator and the cationic polymerization initiator is in the range of 1: 9 to 9: 1 (weight ratio), preferably in the range of 3: 7 to 7: 3 (weight ratio). The total amount of the photopolymerization initiator used is usually 0.1 to 20 parts by weight, preferably 1 to 5 parts by weight, based on 100 parts by weight of the photopolymerizable composition. It is also possible to use two or more kinds of photo radicals and photo cation polymerization initiators in combination.

By curing the photopolymerizable composition of the present invention with a photocuring device as shown in FIG. 1, it is possible to prepare a light control plate which selectively scatters only incident light in a specific angle range. Further, it is possible to use a thermosetting mechanism together within a range that does not hinder performance expression. It is preferable to apply the composition to a substrate during curing, or to enclose the composition in a cell to form a film, and then to irradiate ultraviolet rays from a specific direction to cure the composition. By this method, a light control plate that selectively scatters only incident light having a desired angle can be manufactured.

The light source used in the photopolymerization emits ultraviolet rays that contribute to the photopolymerization, and the light source has a linear shape when viewed from the irradiated position (the film surface of the film of the photopolymerizable composition). The rod-shaped lamp is one of the preferable linear irradiation light sources. When a linear light source is used and the irradiation conditions are adjusted, the resulting film-shaped or sheet-shaped cured product exhibits anisotropy with respect to the long-axis and short-axis directions of the light source and rotates around the long-axis direction of the light source. Only when it is made, the incident light of a specific angle is scattered.

That is, the produced sheet-like (film-like) polymerized and cured product has layered microstructures in which regions having different refractive indexes are periodically present in a state of being oriented in a certain direction, and a specific angle It is considered that more incident light is scattered in regions having different refractive indexes. It is considered that the larger the difference in refractive index between the regions having different refractive indexes, the higher the light scattering ability of the generated light control plate. In order to exhibit a sufficient light scattering ability, it is preferable that the difference in refractive index is 0.01 or more.

[0015]

By the composition and the manufacturing method of the present invention, a light control plate having a maximum haze value of 50% or more and an opaque angle width (width of an angle range of 40% or more haze value) of 20 degrees or more can be easily manufactured. Can be obtained in a process. Further, according to the present invention, a radically polymerizable compound and a cationically polymerizable compound having a vinyl ether as a functional group are used in combination to produce a light control plate having a wider opacity angle than in the case of the combination of radically polymerizable compounds. You can For example, monomer (A)
In the combination of the polymerizable compounds of the oligomer (B) and the oligomer (B), when a certain radical polymerizable compound is selected as one common monomer (A) and the other oligomer (B) is changed, the functional group of the oligomer (B) is an acrylate. The radical opaque compound having the same basic structure as that of the radical polymerizable compound and having only the functional group a cationically polymerizable compound such as vinyl ether has a wider opacity angle range. be able to. That is, the present invention provides a composition and a manufacturing method for expanding the opaque angular width of a light control plate. The light control plate manufactured by the method of the present invention is a film-shaped or sheet-shaped member, but it can be used by laminating it on a glass plate or another plastic plate. Further, by using these, application to various fields such as window materials for buildings and vehicles, displays, mirrors, greenhouses, office equipment members, etc. can be expected.

[0016]

EXAMPLES The present invention will be described in more detail with reference to examples below, but the present invention is not limited to these examples. In addition, "part" in an Example means a weight part.

Example 1 Bisphenol A diethoxy was added to 50 parts of vinyl ether urethane (refractive index 1.497) having an average molecular weight of 700 obtained by the reaction of polypropylene glycol, 2,4-toluene diisocyanate and 4-hydroxybutyl vinyl ether. Diacrylate (refractive index 1.54
0) 50 parts, ADEKA OPTOMER SP as a photopolymerization initiator
-150 (trade name: manufactured by Asahi Denka Co., Ltd.), and a photopolymerizable composition obtained by adding and mixing 1.0 part of 2-hydroxy-2-methylpropiophenone on a glass plate to a thickness of 200 μm. Is applied to form a film, and the lamp length is 25 cm and is 30 w /
cm UV lamp is used, and the slit distance is set to 4 cm. The irradiation distance is 40 cm.
Was irradiated with ultraviolet rays for 2 minutes to perform photopolymerization to obtain a cured film. The haze value of the obtained cured film was measured and the results are shown in Table 1.

Example 2 To 50 parts of vinyl ether urethane (refractive index 1.496) having an average molecular weight of 1000 obtained by the reaction of polypropylene glycol, 2,4-toluene diisocyanate and 4-hydroxybutyl vinyl ether,
50 parts of hydroxy-3-phenoxypropyl acrylate (refractive index 1.526), 1.5 parts of adekaoptomer SP-150 as a photopolymerization initiator, 2-hydroxy-2-
A photopolymerizable composition to which 1.0 part of methylpropiophenone was added and mixed was cured under the same conditions as in Example 1 and the haze value was measured. The results are shown in Table 1.

Comparative Example 1 50 parts of vinyl ether urethane (refractive index 1.496) having an average molecular weight of 1000 obtained by the reaction of polypropylene glycol, 2,4-toluene diisocyanate and 4-hydroxybutyl vinyl ether, and adecapoto as a photopolymerization initiator. Instead of using 1.5 parts of mer SP-150, 1.0 part of 2-hydroxy-2-methylpropiophenone, an average obtained by reacting polypropylene glycol with 2,4-toluene diisocyanate and 4-hydroxyethyl acrylate. A cured film was obtained in the same manner as in Example 2 except that 50 parts of a urethane acrylate having a molecular weight of 1000 (refractive index 1.498) and 1.5 parts of 2-hydroxy-2-methylpropiophenone were used as a photoinitiator. The haze value was measured under the same conditions as in Example 2, and the results are shown in Table 1.

[0020]

[Table 1]

Example 3 50 parts of caprolactone-modified hydroxypivalic acid neopentyl glycol diacrylate (refractive index 1.468), 50 parts of triethylene glycol divinyl ether (refractive index of 1.469), and ADEKA as a photopolymerization initiator Optomer SP-150 1.5 parts, 2-hydroxy-
A photopolymerizable composition to which 1.0 part of 2-methylpropiophenone was added and mixed was cured under the same conditions as in Example 1, the haze value was measured, and the results are shown in Table 2.

Comparative Example 2 Triethylene glycol divinyl ether (refractive index 1.
469) 50 parts, Adekaoptomer SP-1501.5 parts as a photoinitiator, and 1.0 part of 2-hydroxy-2-methylpropiophenone as an alternative to triethylene glycol diacrylate (refractive index 1. 463) 5
0 part, the same resin as in Example 3 except that 1.5 parts of 2-hydroxy-2-methylpropiophenone was used as the photopolymerization initiator, and a cured film was obtained under the same curing conditions, as in Example 3. The haze value was measured under the above conditions and the results are shown in Table 2.

[0023]

[Table 2]

[Brief description of drawings]

FIG. 1 is a side view of an example of an ultraviolet irradiation device used for manufacturing of the present invention.

[Explanation of symbols]

 1. Stick-shaped UV lamp 2. Slit (spacing 4 cm) 3. 3. Film-like body of photopolymerizable composition (on glass plate) 4. Radiation reflector 5. Lamp box

Claims (2)

[Claims] 1. A photopolymerizable composition comprising two or more polymerizable compounds having different refractive indexes, wherein the polymerizable compound is a cationically polymerizable compound having a radical polymerizable compound and vinyl ether as functional groups. A photopolymerizable composition for a light control plate, which is used in combination. 2. A film-like body of a photopolymerizable composition containing two or more polymerizable compounds having different refractive indexes is irradiated with ultraviolet rays from a specific direction to cure the photopolymerizable composition and cure at a specific angle. In a method for producing a light control plate that selectively scatters only incident light in a range, a composition containing a radically polymerizable compound and a cationically polymerizable compound having a vinyl ether as a functional group is used as the photopolymerizable composition. A method for producing a light control plate, characterized in that a radical polymerization mechanism and a cationic polymerization mechanism are used together.