JPH03220205A - Resin composition for light controlling plate and light intensity-regulating plate - Google Patents

Abstract

PURPOSE:To obtain the title composition which can give a light controlling film of a reduced thickness and therefore of improved economy by adding a filler of a specified particle diameter to three specified photopolymerizable compositions. CONSTITUTION:A resin composition for a light intensity-regulating plate is formed by adding 0.01-5 pts.wt. filler of a mean particle diameter of 0.05-20mum to 100 pts.wt. at least one photopolymerizable resin composition selected from among a composition containing at least two monomers or oligomers which have a polymerizable C-C double bonds and are capable of forming polymers of different refractive indices, a composition containing a compound free of any polymerizable C-C double bond and at least one monomer or oligomer having a polymerizable C-C double bond and being capable of forming a polymer of a refractive index different from those of the above polymers, and a composition containing at least one monomer or oligomer having a plurality of polymerizable C-C double bonds in the molecule and differing in the refractive indices before and after being polymerized.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a resin composition for a light control board and a light control board obtained from the same.

<Prior Art> It has been proposed to obtain a light control plate by irradiating a photopolymerizable composition containing at least two types of compounds with different refractive indexes with ultraviolet rays. (Japanese Unexamined Patent Publication No. 1-147405) Compositions using urethane yarn threads, oligomers, bromine-containing monomers, etc. exhibit high optical properties when used as light control plates.

<Problems to be Solved by the Invention> However, although these compositions exhibit excellent light control properties, further improvements have been desired. Specifically, in order to have a high haze value in the opaque region (the region where incident light is scattered) and to obtain a straight light transmittance of 95% or more in the transparent region (the region where the incident light is transmitted), the composition is The film thickness upon curing was required to be 200 to 300 μm, but even thinner film thickness was desired.

Thinner light control plates are desired from two viewpoints. 1st
Another problem is due to the heat of polymerization in industrial scale manufacturing of light control plates. In other words, the film thickness of the photopolymer is 2
00 to 300 μm is a relatively thick film, and it is formed in the cured product due to deformation of the substrate coated with the composition and curing distortion of the cured product (light control film) itself due to the instantaneous large amount of heat generated during polymerization. This also caused disturbances in the structure that exhibits the optical properties. It is expected that suppression of large amounts of heat generation and curing distortion in the manufacturing process will be greatly improved by reducing the thickness of the composition to be applied.

Second, by making the film thinner, the amount of the composition used can be reduced, resulting in improved economic efficiency.

Means for Solving the Problems The present invention provides a composition containing at least two types of monomers or oligomers each having a polymerizable carbon-carbon double bond and capable of producing a polymer having a different refractive index, A compound having no polymerizable carbon-carbon double bond and at least one polymer capable of producing a polymer having a polymerizable carbon-carbon double bond and having a refractive index different from the refractive index of the compound.
At least one of the compositions containing at least one kind of monomer or oligomer having multiple polymerizable carbon-carbon double bonds in the molecule and having different refractive indexes before and after polymerization. A light control plate layer resin composition, characterized in that 0.01 to 5 parts by weight of a filler having an average particle size of 0.05 to 20 μm is blended to 100 parts by weight of a photopolymerizable resin composition of selected species; And a light control board obtained by irradiating the light control board layer resin composition with light is provided.

The present invention will be explained in detail below.

One of the photopolymerizable compositions used in the present invention contains at least two types of monomers or oligomers that have polymerizable carbon-carbon double bonds and are capable of producing polymers each having a different refractive index. compositions. The monomer or oligomer used here is a compound having at least one carbon-carbon double bond in the molecule,
For example, acryloyl group, methacryloyl group,
A monomer or oligomer containing one or more polymerizable groups such as a vinyl group or an allyl group. Any combination can be used as long as it can be polymerized by light, such as ultraviolet light, can produce polymers with different refractive indexes, has a suitable reactivity ratio, and has appropriate compatibility. can also be used, but it is determined as necessary by taking into account the chemical and physical properties of the resin. Suitable examples include polyester acrylate, polyol polyacrylate, modified polyol polyacrylate, isocyanuric acid skeleton polyacrylate, melamine acrylate, hydantoin skeleton polyacrylate, polybutadiene acrylate, epoxy acrylate, polyfunctional acrylate such as urethane acrylate. and methacrylates corresponding to these acrylates, or tetrahydrofurfuryl acrylate, ethylcarpitol acrylate, dicyclopentenyloxoethyl acrylate,
Phenylcarpitol acrylate, nonylphenoquine ethyl acrylate, 2-hydroxy-3-phenoxypropyl acrylate, ω-hydroxyhexanoyloxyethyl acrylate, acryloinoleoxyethyl succinate, acryloyloxyethyl phthalate, phenyl acrylate, tribromophenyl acrylate, Phenoxyethyl acrylate, tribromophenoxyethyl acrylate, benzyl acrylate, p-bromobenzyl acrylate, bisphenol A diacrylate, 2,2-bis(4-methacryloxyethoxy-
3,5-dibromophenyl)propane, isobornyl acrylate, 2-ethylhexyl acrylate, lauryl acrylate, 2,2.3.3-tetrafluoropropyl acrylate, and methacrylates corresponding to these monofunctional acrylates, and styrene, ρ-chlorostyrene, divinylhenzene, vinyl acetate,
Examples include vinyl compounds such as acrylonitrile, N-vinylpyrrolidone, and vinylnaphthalene, and allyl compounds such as diethylene glycol bis(allyl carbonate), triallylisocyanurate, diallylidenepentaerythritol, diallylphthalate, and diallylisophthalate.

The photopolymerizable composition used in the present invention uses at least two types selected from these photopolymerizable monomers or oligomers as a mixture, but the refractive index of the two types of homopolymers must not differ from each other. No. At least two monomers or oligomers are at least 0
．． When using three or more types of photopolymerizable polymers or oligomers, it is desirable to have a refractive index difference (in the homopolymer) of 0.01, more preferably at least 0.05, their It is sufficient that the difference in refractive index between any two of the homopolymers satisfies the above conditions. The mixing ratio of two types of photopolymerizable polymers or oligomers having a refractive index difference of at least 0.01 is from 10:90 to 10:90 by weight.
It is preferably in the range of 9o:to.

A preferred example of a composition containing at least two monomers or oligomers that have polymerizable carbon-carbon double bonds and can produce polymers with different refractive indexes is polyether urethane acrylate and ethylene oxide modified A homogeneous mixture in combination with tribromophenol acrylate (difference in refractive index of polymers of about 0.14) can be mentioned. These monomers or oligomers not only differ in refractive index from each other (but also in reactivity (reaction rate) in order to form phase-separated structures that exhibit light control functions.
must also be different from each other.

Other photopolymerizable compositions used in the present invention include a compound that does not have a polymerizable carbon-carbon double bond and a compound that has a polymerizable carbon-carbon double bond and has a refractive index different from the refractive index of the compound. Examples include compositions containing at least one monomer or oligomer capable of forming a polymer. This compound that does not have an intramolecular G-polymerizable carbon-carbon double bond is a compound that does not contain a polymerizable group such as an acryloyl group, a methacryloyl group, a hinyl group, or an allyl group in the molecule. For example, polymers such as polystyrene, polymethyl methacrylate, polyethylene oxide, polyvinylpyrrolidone, polyvinyl alcohol, nylon, polyalkylene glycols such as polyethylene glycol and polypropylene glycol, toluene, n-hexane,
Examples include organic compounds such as cyclohexane, methyl alcohol, ethyl alcohol, acetone, methyl ethyl ketone, tetrahydrofuran, ethyl acetate, dimethyl formamide, dimethyl acetamide, acetonitrile, and plastic additives such as halogen compounds, plasticizers, and stabilizers of these organic compounds. It will be done.

Furthermore, the above-mentioned monomers or oligomers capable of producing a polymer having a polymerizable carbon-carbon double bond and having a refractive index different from that of the compound can be used. The refractive index of the compound and the polymer refractive index of the monomer or oligomer must be different. The difference in refractive index is small (both 0.
01, more preferably at least 0.05. The mixing ratio of the compound and the monomer or oligomer is preferably in the range of 10:90 to 90:10 by weight.

Compositions containing the compound and at least one monomer or oligomer capable of forming a polymer having a refractive index different from that of the compound are preferred. For example, a homogeneous mixture of polystyrene (refractive index: 1.59) and polyether urethane acrylate (polymer refractive index: 1.49) may be used.

Other photopolymerizable compositions used in the present invention include compositions containing at least one monomer or oligomer having multiple polymerizable carbon-carbon double bonds in the molecule and having different refractive indexes before and after polymerization. Can be mentioned. This monomer or oligomer contains an acryloyl group,
A monomer or oligomer containing at least two polymerizable groups such as a methacryloyl group, a vinyl group, or an allyl group, with different refractive indexes before and after polymerization, preferably at least 0. It is a compound having a refractive index difference of Of. Specifically, for example, triethylene glycol acrylate, polyethylene glycol diacrylate, neopentyl glycol diacrylate, 1,6-hexanediol diacrylate, hydrogenated dicyclopentagenyl diacrylate, ethylene oxide modified bisphenol A diacrylate, Methylolpropane triacrylate, pentaerythritol hexaacrylate, tris(acryloxy)in cyanurate, polyfunctional urethane epoxy acrylate, polyfunctional urethane acrylate, polyfunctional modified polyol polyacrylate, and methacrylates corresponding to these acrylates. Examples include divinylhensen, triallyl isocyanurate, diethylene glycol bis(allyl carbonate), and the like.

As an example, trimethylolpropane triacrylate (
The refractive index before and after polymerization is 1.477 and 1.520, respectively.
).

In order to improve curability, it is preferable to add a photopolymerization initiator.

The photopolymerization initiator is not particularly limited, and includes those used in ordinary photopolymerization.

For example, benzophenone, penzyl Michler's ketone, 2-chlorothioxanthone, 2.4-diethylthioxanthone, benzoin ethyl ether, jetoxyacetophenone, benzyl dimethyl ketal, 2-hydroxy-2-methylpropiophenone, ■-hydroxycyclo Examples include xylphenyl ketone.

In the present invention, inorganic fillers, organic fillers, and even pigments can be used as fillers.

Examples of the inorganic filler include silica, calcium carbonate, alumina, mixtures thereof, and those whose surfaces are hydrophobically modified.

Examples of the organic filler include polyolefins such as polyethylene and polypropylene, various ethylene copolymers, polyester, polyamide, polystyrene, polyvinyl chloride, polycarbonate, polysulfone, and poly(meth)acrylate.

It is also possible to use mixtures of these polymers. As the polyacrylate, homopolymers or copolymers of aliphatic acrylates, aromatic acrylates, and metal-containing acrylates (ionomers) can be used. Further, homopolymers and multi-component copolymers of monomers having the following monosubstituent group or structure can also be used as the filler of the present invention.

-X, -OH, -No□, CN, N Hz
.

-NHR,, -NR,R2, -R:l, -OR,,
-COOI(0000 NHCNH, NHC-QC 0 OS 0 where, X: halogen R1, Rt: alkyl group R3: alkyl group, aryl group, or hydrogen R,,R,
: Alkyl group or aryl group Furthermore, when a pigment is used as the filler used in the present invention, a coloring effect can be achieved in addition to the filler effect.

Examples of pigments include titanium white, lead white, Co compounds, F
Examples include inorganic pigments such as e-compounds, Cr compounds, and Cd compounds, and organic pigments such as phthalocyanine-based, dioxazine-based, and anthraquinone-based pigments.

to 20 μm, preferably 0.1 to 10 μm.

If the average particle diameter is less than 0.05 μm, the optical properties will not be much different from those without the filler and will not be effective. In addition, when the average particle size exceeds 20 μm, transparency decreases,
Undesirable.

In the composition of the present invention, the amount of filler added has a large effect on the optical properties of the light control plate. The more the filler is added, the more it is seen that the formation of microstructures that exhibit light control properties is promoted, but on the other hand, if the filler is added too much, scattering phenomena will occur even in areas that are originally transparent, which is undesirable.

Therefore, the amount added varies depending on the type of filler, but is 0.0 parts by weight per 100 parts by weight of the photopolymerizable resin composition.
The amount is selected in the range of 1 to 5 parts by weight, preferably 0.03 to 3 parts by weight, and more preferably 0.05 to 1 part by weight.

The production of the light control plate layer resin composition of the present invention is not particularly limited, and can be carried out by commonly used blending and mixing methods.

A so-called mask-hatch method may also be used to improve the dispersion of the filler.

The method for producing a light control board from the resin composition of the present invention is also not particularly limited. For example, in addition to forming a thin film of a resin composition on a base material and performing light irradiation using a punch method or a continuous process, there are also methods in which a resin composition is interposed between two substrates with a spacer in between, and then light irradiation is performed. You can use different methods depending on the purpose.

As the light source for irradiation, visible light, ultraviolet light, or other light source that causes a polymerization reaction is used, and ultraviolet light is particularly preferably used.For example, a mercury lamp, a metal halide lamp, etc. are used.

<Effects of the Invention> By photopolymerizing using the composition of the present invention, a light control film that conventionally required a thickness of 200 to 300 μm to obtain good light control properties can be made into a thin film of 100 μm or less. I was able to do that. As a result, it is possible to suppress heat generation during curing and prevent curing distortion. Furthermore, the amount of composition used was reduced, and the economical efficiency was also significantly improved.

<Examples> Hereinafter, the present invention will be further explained with reference to Example S, but the present invention is not limited to these Examples.

Example 1 Polyether urethane acrylate (refractive index 1.488) consisting of polytetramethylene ether glycol, toluene diisocyanate, and hydroxyethyl acrylate
), 100 parts by weight of tribromophenyl methacrylate (refractive index 1.620), and 6 parts by weight of henzyl dimethyl ketal, and polyfunctional acrylate (DPCA) manufactured by Nippon Kayaku ■.
Photopolymerizable resin composition 10 is prepared by adding microbeads having an average particle size of 1 to 2 μm of aliphatic polyacrylate obtained by suspension polymerization of
0.05 parts by weight was blended with respect to 0 parts by weight. The obtained composition was applied to a predetermined film thickness (75 μm) on a substrate, placed 1 m below a rod-shaped UV lamp (80w/cta x 70c+i length), and UV irradiated for about 1 minute to form a cured film. Obtained. The scattering property of the incident light of this cured film was evaluated by the haze value (haze rate) and is shown in Table 1.

The haze value was determined by measuring the total light transmittance and scattered transmittance using an integrating sphere light transmittance device according to JIS K 6714.

Example 2 A cured film was obtained in the same manner as in Example 1, except that 1.0 parts by weight of the microbeads used in Example 1 were added.

The haze value of the cured film was measured and recorded in Table 1.

Example 3 A block polymer prepared using the same monomer as the micropieces synthesized in Example 1 was finely pulverized to an average particle size of 5 μm.
An irregularly shaped polyacrylate powder of m was obtained. A cured film was prepared in the same manner as in Example 1, except that 0.05 parts by weight of the obtained powder was used.

The haze value of the cured film was measured and recorded in Table 1.

Example 4 Amorphous silica with an average particle diameter of 10 μm was used as a filler at 0.00 μm.
A cured film was obtained in the same manner as in Example 1 except that 0.05 parts by weight was used.

The haze value of the cured film was measured and recorded in Table 1.

Example 5 Use 8 as a filler with an average particle size of 5 μm! A cured film with a thickness of 100 μm FJ was obtained by straining in the same manner as in Example 1 except that 0.4 parts (1 part) of the pigment phthalocyanine (irregular shape) was used.

The haze value of the cured film was measured and recorded in Table 1.

Comparative Example 1.2 Cured films with thicknesses of 75 μm and 200 μm were obtained in the same manner as in Example 1, except that no filler was used.

Their haze values were measured and reported in Table 1.

Comparative Example 3 A cured film was obtained in the same manner as in Example 1, except that 7.5 parts by weight of the aliphatic polyacrylate microbeads used in Example 1 were added.

The haze value of the cured film was measured and recorded in Table 1.

Comparative Example 4 A cured film was obtained in the same manner as in Example 1, except that 0.005 parts by weight of the aliphatic polyacrylate microbeads used in Example 1 were added.

The haze value of the cured film was measured and recorded in Table 1.

Comparative Example 5 Same as Example 1 except that 0.05 coated portions were mixed with the aliphatic polyacrylate microbeads used in Example I and had an average particle size of 75 μm. A cured film was obtained.

The haze value of the cured film was measured and recorded in Table 1.

Example 6 Polyfunctional acrylate (DPCA) manufactured by Nippon Kayaku ■ (refractive index before and after polymerization is 1.486 and 1.518, respectively) 1
Microbeads of polymethyl methacrylate (PMMA) with an average particle size of 0.1 μm were added to a photopolymerizable resin composition consisting of 0.00 parts by weight and 3 parts by weight of 2-hydroxy-2-methylpropiophenone. 0.1 part by weight was added to 100 parts by weight.

The obtained composition was subjected to UV irradiation in the same manner as in Example 1,
A cured film was obtained.

The haze value of the cured film was measured and recorded in Table 1.

Example 7 A cured film was obtained in the same manner as in Example 6, except that 0.5 parts by weight of the polymethyl methacrylate microbeads used in Example 6 were added.

The haze value of the cured film was measured and recorded in Table 1.

Comparative Example 6 A cured film was obtained in the same manner as in Example 6 except that polymethyl methacrylate microbeads were not used.

The haze value of the cured film was measured and recorded in Table 1.

Example 8 60 parts by weight of 2-hydroxy-3-phenoxypropylacrylate (refractive index 1.524), polypropylene glycol/phenylisocyanate adduct (refractive index 1.524).
468) Polymethyl methacrylate (PMMA) with an average particle size of 0.1 is added to a photopolymerizable resin composition consisting of 40 parts by weight and 3 parts by weight of 2-hydroxy-2-methylpropiophenone.
0.1 part by weight of μm microbeads was blended with 100 parts by weight of the photopolymerizable resin composition.

The obtained composition was subjected to UV irradiation in the same manner as in Example 1,
A cured film was obtained.

The haze value of the cured film was measured and recorded in Table 1.

Comparative Example 7 A cured film was obtained in the same manner as in Example 6 except that polymethyl methacrylate microbeads were not used.

The haze value of the cured film was measured and recorded in Table 1.

Claims (2)

[Claims] (1) A composition containing at least two types of monomers or oligomers having polymerizable carbon-carbon double bonds and capable of producing polymers each having a different refractive index; at least one compound having a polymerizable carbon-carbon double bond and capable of producing a polymer having a refractive index different from that of the compound.
At least one of the compositions containing at least one kind of monomer or oligomer having multiple polymerizable carbon-carbon double bonds in the molecule and having different refractive indexes before and after polymerization. A resin composition for a light control board, characterized in that 0.01 to 5 parts by weight of a filler having an average particle size of 0.05 to 20 μm is blended to 100 parts by weight of a photopolymerizable resin composition of a selected type. (2) A light control board obtained by irradiating the resin composition for a light control board obtained in claim 1 with light.