JPH0525233A - High-refractive-index resin composition - Google Patents

Abstract

PURPOSE:To obtain the subject composition which has a low specific gravity and excellent transparency, heat resistance and process-ability and can be easily molded by using a (meth)acrylate (co)polymer as a component. CONSTITUTION:A resin composition comprising a polymer prepared by polymerizing a monomer (a) of formula I (wherein R is H or methyl; and (n) is 2 or 3) or a mixture thereof with another monomer (b) copolymerizable therewith. The monomer (a) can be obtained by reacting alpha,alpha'-dichloroxylenol with mercaptoethyl sulfide or ethylenebis(2-mercaptoethyl sulfide) in an aqueous alkali solution to form a compound of formula II and (meth)acrylating the compound of formula II. It is desirable that monomer (a) is present in an amount of 20wt.% or above based on the mixture. When the amount of monomer (b) used is excessively large, any of the transparency, surface properties, surface hardness heat resistance, processability, impact resistance, etc., of the product are worsened.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-refractive-index resin composition, particularly a high-refractive-index resin composition having excellent transparency, low specific gravity, excellent heat resistance and processability, and easy to mold. .

2. Description of the Related Art Conventionally, various researches have been made and proposed and put into practical use for synthetic resins which replace inorganic glass. For example, diethylene glycol bisallyl carbonate can be mentioned. However, since the refractive index of diethylene glycol bisallyl carbonate is as low as 1.50, various resins have been developed recently, and the refractive index is 1.60.
High refractive index resin close to For example, a resin containing an aromatic ring, a halogen atom or a sulfur atom in the molecule, and a resin containing a thiourethane bond obtained by reacting an isocyanate compound with a polythiol have been proposed and put into practical use. Further, as for a high refractive index resin having a refractive index of 1.60 or more, a compound containing a large number of sulfur atoms has been proposed.

However, conventional resins do not always satisfy all the required physical properties. That is, the resin containing halogen for increasing the refractive index has a specific gravity of 1.40 or more and becomes heavy. Further, a resin utilizing the urethane reaction has a problem in that it is inferior in moldability during cast polymerization. Further, in order to obtain a compound containing a large number of sulfur atoms, a special starting material is often used or a multistep reaction is required. An object of the present invention is to provide a high refractive index resin composition having a low specific gravity, excellent heat resistance and processability, and easy to mold.

The inventors of the present invention have completed the present invention as a result of intensive research to improve the problems of conventional resins.

That is, the present invention has the general formula [1]

[0003]

[Chemical 1]

(In the formula, R represents hydrogen or a methyl group,
n represents 2 or 3. ) A high refractive index composed of a polymer obtained by polymerizing a monomer (a) of acrylate or methacrylate represented by (1) or a mixture of another monomer (b) and a monomer (a) copolymerizable therewith. Resin composition.

The (meth) acrylate monomer (a) represented by the general formula [1] used in the high refractive index resin composition of the present invention can be obtained by the following method.

That is, α, α'-dichloro-xylene,
Mercaptoethyl sulfide or ethylene bis (2-
(Mercaptoethyl sulfide) is reacted in an alkaline aqueous solution to synthesize the compound represented by the general formula [2]. Then, the compound represented by the general formula (2) is subjected to a (meth) acrylate reaction to obtain the (meth) acrylate represented by the general formula [1]. A known method can be used for this reaction. For example, the compound represented by the general formula (2) is reacted with (meth) acrylic acid chloride in toluene in the presence of a polymerization inhibitor and a tertiary amine, or in toluene, the polymerization inhibitor and a tertiary amine are present. Under the following, the compound represented by the general formula (2) is esterified with (meth) acrylic acid. General formula [2]

[0007]

[Chemical 2]

(In the formula, n represents 2 or 3.) In the present invention, only the monomer (a) of the (meth) acrylate may be polymerized, but the physical properties of the monomer and the polymer are improved. Therefore, a mixture of another monomer (b) copolymerizable with the monomer (a) and the monomer (a) may be copolymerized. However, if the amount of monomer (b) is too large, the transparency, surface property, surface hardness, heat resistance, processability, impact resistance, low specific gravity, high refractive index, or moldability of the product will decrease. Therefore, it is desirable that this mixture contains at least 20% or more of the (meth) acrylate represented by the general formula [1], more preferably 40% or more.

As the monomer (b), a compound having at least one radically polymerizable functional group containing a carbon-carbon double bond in the molecule can be used. Specific examples of this monomer (B) are given below.

Maleimides such as N-phenylmaleimide, N- (2-chlorophenylmaleimide) and N- (2,6-diethylphenylmaleimide). Styrene, divinylbenzene,
Vinyl compounds such as 4-chlorostyrene. A methacrylate with one functional group such as phenyl methacrylate, phenoxyethyl acrylate, benzyl methacrylate, dicyclopentenyl acrylate. 2,2'-bis (4-acryloxyethoxyphenyl) propane, 2,2'-bis (4-
Methacryloxyethoxyphenyl) propane, 2,2'-bis (4-methacryloxydiethoxyphenyl) propane,
Dimethacrylic acid ester in which a + b is 10 (for example, NK ester BPE-500 manufactured by Shin-Nakamura Chemical Co., Ltd.) 2,2 '
-Bis (4-methacryloxy-3,5-dibromophenyl) propane, 2,2'-bis (4-methacryloxyethoxy-3,5-
Dibromophenyl) propane, 2,2'-bis (4-acryloxyphenyl) sulfone, 2,2'-bis (4-acryloxyethoxyphenyl) sulfone, 2,2'-bis (4-acryloxyethoxy-3 Has an aromatic ring such as 2,5-dibromophenyl) sulfone, bis (4-acryloxyphenyl) sulfide, bis (4-methacryloxyphenyl) sulfide, bis (4-methacryloxyethoxy-3,5-dibromophenyl) sulfide Methacrylates having two functional groups. Ethylene glycol diacrylate, tetraethylene glycol diacrylate, nano ethylene glycol diacrylate, tetraethylene glycol dimethacrylate, 1,6-hexanediol diacrylate, 1,9-nonanediol diacrylate, neopentyl glycol dimethacrylate, trimethylolpropane Methacrylates as aliphatic alcohol derivatives such as trimethacrylate. Monomers having an allyl group such as allyl benzoate, terephthalic acid bisallyl ester, isophthalic acid bisallyl ester, trimellitic acid triallyl ester, pyromellitic acid tetraallyl ester and diallyl diphenate.

The method for polymerizing the resin composition of the present invention is not particularly limited, and a known polymerization method can be adopted. For example, the monomer or mixed solution is cured by heating it in the presence of a polymerization initiator between the molds held by gaskets or spacers, but resin molding can also be performed by photopolymerization or radiation polymerization instead of heating. The thing can be manufactured. The polymerization initiator used here is not particularly limited, and known ones can be used. Examples of the polymerization initiator used for heat curing include, for example, 2,2′-azobis (2-cyclopropylpropionitrile), 2,2′-azobis (2,4-dimethylvaleronitrile), dimethyl 2, 2'-
Azo compounds such as azobis (2-methylpropionate), or t-butylperoxyisobutyrate, t-butylperoxypivalate, t-butylperoxy (2-ethylhexanoate), t- Peroxyesters such as butylperoxyisopropyl carbonate, peroxydicarbonates such as diisopropylperoxydicarbonate, diacyl peroxides such as benzoyl peroxide, dialkyl peroxides such as dicumyl peroxide, 1,1, Examples include peroxyketals such as bis (t-butylperoxy) cyclohexane, and other peroxides. Further, when it is cured with ultraviolet rays, benzoin isopropyl ether, benzophenone, benzoin isobutyl ether and the like can be mentioned as the initiator, but the initiator is not limited to these. The amount of the polymerization initiator is usually 0.001 to 10% by weight, preferably 0.
It is from 01 to 5% by weight. The type and concentration of the polymerization initiator to be used are determined in consideration of the composition, reactivity, reaction rate control, etc. of the monomer mixture solution.

Further, the resin composition of the present invention preferably contains 0.01 to 3.0% by weight of an ultraviolet absorber in order to improve its light resistance and weather resistance, if necessary. If the concentration of the ultraviolet absorber is less than 0.01% by weight, there is almost no effect of improving the light resistance and weather resistance, and if it exceeds 3.0% by weight, unfavorable yellow coloring is conspicuous and the commercial value is apt to decrease. . The ultraviolet absorber used in the present invention includes benzotriazole-based, benzophenone-based,
In addition to salicylic acid-based and cyanoacrylate-based compounds, hindered amine-based UV stabilizers, Ni complex-based compounds, and benzoate-based compounds can be widely used.

Upon polymerization, if necessary, a release agent,
Additives such as antioxidants, antistatic agents, various stabilizers, and bluing agents may be contained. Further, the resin molded product of the present invention may be coated on the surface of the molded product in order to improve optical and mechanical stability.

The resin composition of the present invention has transparency, surface property,
It has excellent surface hardness, heat resistance, workability and impact resistance, has a low specific gravity of 1.39 or less, and has a refractive index higher than that of diethylene glycol bisallyl carbonate resin (CR-39, refractive index about 1.50). It is higher than 1.60,
It is extremely excellent as a material for optical materials. Furthermore, the polymerization method is simple and the moldability is good.

The resin composition of the present invention is used for optical materials such as eyeglass materials, so-called lenses such as camera lenses, prisms, disks such as video disks, concave mirrors, mirrors such as polygons, optical fibers and the like. It is preferably used as a refractive index coating agent.

EXAMPLES Examples of the present invention will now be described, but the present invention is not limited to these. The test method for each property was as follows.

Moldability: During casting polymerization, those that were mold-molded were good (○), those with slight peeling were slightly good (△), and those with severe peeling were poor (×). did.

Heat resistance: A sample lens left in a hot air dryer at 120 ° C. for 1 hour was taken out, and the distortion of the reflected image on the surface was not visually observed (○), and the distortion was slightly observed ( Δ), and those in which a considerable strain can be observed were designated as (x).

Workability: A sample lens is ground by a ball-shaving machine for processing spectacle lenses, and the one having a good polished surface is good (○), the one having a good polishing is a little good (△), and the one having a bad surface is poor (×). And

Appearance: Colorless and transparent (o), slightly yellow colored (Δ), and fairly yellow colored (x).

Refractive Index and Abbe Number: Measured with an Abbe refractometer. Example 1 17.5 g (0.1 mol) of α, α'-dichloro-m-xylene and 32.4 g (0.2 mol) of mercaptoethyl sulfide
1 mol) was reacted in an alkaline aqueous solution to obtain 28.7 g of compound (A). Then, the compound (A) 20.5
g (0.05 mol) was reacted with 200 mg of toluene and 10.9 g (0.12 mol) of acrylic acid chloride in the presence of 100 mg of a polymerization inhibitor and 8.4 g (0.11 mol) of pyridine to give compound (B). 18.2 g was obtained.

A solution prepared by adding 2 parts of t-butylperoxy (2-ethylhexanoate), a polymerization initiator, to 100 parts of compound (B) was poured into a mold composed of a glass mold and a plastic gasket, and 50 2 ° C to 110 ° C
Polymerization was performed by increasing the temperature over 0 hours. The obtained lens was colorless and transparent and had a refractive index of 1.66.
The results of moldability, heat resistance, workability, appearance, Abbe number, specific gravity, etc. are shown in Table 1.

Compound (A)

[0022]

[Chemical 3]

Compound (B)

[0024]

[Chemical 4]

[0025]

[Table 1]

Example 2 Compound (B-2) was obtained by the same synthesis as in Example 1 except that acrylic acid chloride was changed to methacrylic acid chloride. In the general formula [1], this is R
= Hydrogen, n = 3. Using this, polymerization was carried out in the same manner as in Example 1 to obtain a colorless and transparent lens. The results are shown in Table 1. Example 3 A compound (B-3) was obtained in exactly the same manner as in Example 1 except that α, α′-dichloro-m-xylene was replaced by α, α′-dichloro-P-xylene. This is represented by R = hydrogen and n = 3 in the general formula [1]. Using this, polymerization was carried out in the same manner as in Example 1 to obtain a colorless and transparent lens. The results are shown in Table 1. Example 4 A solution obtained by adding 2 parts of a polymerization initiator t-butylperoxy (2-ethylhexanoate) to 50 parts of compound (B) and 50 parts of benzyl methacrylate was polymerized in the same manner as in Example 1 to give a colorless solution. I got a transparent lens. The results are shown in Table 1. Examples 5 to 7 Compound (B), compound (B-2), compound (B-3) and various polymerizable compounds, that is, divinylbenzene, diallyl diphenate, and N- (2,6-diethylphenylmaleimide). Was used to obtain a colorless and transparent lens. The results are shown in Table 1.

Claims (4)

[Claims] 1. A general formula [1]: (In the formula, R represents hydrogen or a methyl group, and n represents 2 or 3.) A monomer (a) or another monomer (b) copolymerizable therewith and a monomer A high refractive index resin composition comprising a polymer obtained by polymerizing a mixture with the body (a). 2. The high refractive index resin composition according to claim 1, wherein the monomer (a) is contained in the mixture in an amount of at least 20% by weight. 3. The high refractive index resin composition according to claim 2, wherein the monomer (b) is a compound having at least one radically polymerizable functional group containing a carbon-carbon double bond in the molecule. 4. The monomer (b) is a maleimide, a vinyl compound, a methacrylate having one functional group, a methacrylate having two functional groups having an aromatic ring, and a methacrylate as an aliphatic alcohol derivative. The high refractive index resin composition according to claim 2, which is a monomer having a class or an allyl group.