JPH0651763B2 - Method for producing resin having excellent optical properties - Google Patents

Description

The present invention relates to a method for producing a resin having excellent optical properties. More specifically, it relates to a method for producing a transparent resin having a high refractive index and excellent optical properties by polymerizing a certain unsaturated monomer containing chlorine or bromine extremely rapidly.

[Conventional technology]

The high-refractive-index resin is conventionally obtained by polymerizing a monomer containing a group having a large atomic refraction, such as a monomer containing an aromatic ring or a monomer containing a halogen atom. JPA
59-136309, JP-A-59-136310, JP-A-59
In JP-A-136311 and JP-A-60-28412, peroxide-based compounds commonly used are tribromophenyl methacrylate, polyethylene glycol dimethacrylate, methyl methacrylate, styrene, and other vinyl monomers. Alternatively, a method for producing a high-refractive-index resin by liquid-pouring polymerization in the presence of an azo-based radical polymerization initiator is described.

JP-A-60-23408 describes a method in which a polymerization initiator is added to benzyl methacrylate and divinylbenzene and polymerization is performed by thermal polymerization, photopolymerization, radiation polymerization or the like.

[Problems to be solved by the invention]

A polymer containing a halogen atom has a high refractive index and excellent optical properties, but has poor heat resistance, and when melt-molded such as injection molding, problems such as silver streak and thermal decomposition such as coloring tend to occur. is there.

Casting may be considered to avoid thermal decomposition, but in the case of a conventional monomer containing a halogen atom, it is extremely difficult to complete the polymerization rapidly and complete the polymerization. The monomer is likely to remain, and the resulting polymer has a strong odor and poor mechanical and thermal properties.

An object of the present invention is to provide a method for polymerizing a certain chlorine- or bromine-containing unsaturated monomer very rapidly to produce a transparent resin having a high refractive index and excellent optical properties. is there.

According to the method of the present invention, the polymerization is carried out rapidly and the polymerization is completed within 3 hours, so that it can be applied to cast molding.

[Means for solving problems]

The present invention relates to a styrene derivative containing chlorine or bromine in the molecule, a methacrylic acid ester containing chlorine or bromine in the molecule, and an acrylic acid ester containing chlorine or bromine in the molecule. (1) a radical polymerization initiator, (2) a reducing substance containing sulfur in the molecule, wherein the monomer contains at least one monomer selected from the group consisting of (3) A method for producing a resin having excellent optical properties, which comprises polymerizing in the presence of a hydrogen halide salt of amine or quaternary ammonium halide and (4) a copper-containing compound.

Styrene derivatives containing chlorine or bromine in the molecule used in the present invention, those whose aromatic ring is chlorinated or brominated are used, for example, monochlorostyrene, dichlorostyrene, trichlorostyrene, monobromostyrene, dibromostyrene, Tribromostyrene, monochloro α-methylstyrene, dichloro α-methylstyrene,
Examples include trichloro α-methylstyrene and the like.

Further, (meth) acrylic acid ester [(meth) containing chlorine or bromine in the molecule indicates both the case with and without meta. The same shall apply hereinafter) is a (meth) acrylic acid ester of an aliphatic, alicyclic or aromatic alcohol or phenol containing chlorine or bromine. Particularly preferred (meth) acrylic acid esters include, for example, those represented by the formulas (I) to (VI).

(In the formula, R ₁ is hydrogen or a methyl group, and A is —CH ₂ CH ₂ O—.
Or X represents chlorine or bromine, m represents an integer of 1 to 5, and n represents an integer of 0 to 5. ) (In the formula, R ₁ and R ₂ are hydrogen or a methyl group, and A is —CH ₂ CH ₂
O- or X represents chlorine or bromine, n and p represent an integer of 0 to 5, and q and l represent an integer of 1 to 4. ) (In the formula, R ₁ is hydrogen or a methyl group, and A is —CH ₂ CH ₂ O—.
Or X represents chlorine or bromine, m represents an integer of 1 to 5, r represents an integer of 1 to 5, and s represents an integer of 1 to 2. ) (In the formula, R ₁ is hydrogen or a methyl group, and A is —CH ₂ CH ₂ O—.
Or X represents chlorine or bromine, m represents an integer of 1 to 5, and n represents an integer of 0 to 5. ) (In the formula, R ₁ is hydrogen or a methyl group, and A is —CH ₂ CH ₂ O—.
Or X represents chlorine or bromine, n represents an integer of 1 to 5, t represents an integer of 0 to 3, and u represents an integer of 1 to 18. ) (In the formula, R ₁ is hydrogen or a methyl group, and A is —CH ₂ CH ₂ O—.
Or X represents chlorine or bromine, n represents an integer of 1 to 5, u represents an integer of 1 to 18, and v represents an integer of 1 to 3. ) More specific compounds include monobromophenyl (meth) acrylate, dibromophenyl (meth) acrylate, tribromophenyl (meth) acrylate, monochlorophenyl (meth) acrylate, dichlorophenyl (meth) acrylate, trichlorophenyl (meth).
Acrylates and those in which the alcohol part of these esters contains an ethyleneoxy, diethyleneoxy, triethyleneoxy, propyleneoxy, dipropyleneoxy or tripropyleneoxy group as An of formula (I);
Dibromobisphenol-A di (meth) acrylate,
Tetrabromobisphenol A di (meth) acrylate and bisphenol moiety of these esters containing ethyleneoxy, diethyleneoxy, triethyleneoxy, propyleneoxy, dipropyleneoxy, tripropyleneoxy bond as An or Ap of formula (II) Dibromodi [2- (meth) acryloxyethyl] phthalate, tetrabromodi [2- (meth) acryloxyethyl] phthalate, bromocyclohexyl (meth) acrylate, dibromocyclohexyl (meth) acrylate, tribromocyclohexyl (meth) acrylate , Tetrabromocyclohexyl (meth) acrylate, and the alcohol portion of these esters with the formula (II
Am containing I) or An of formula (IV) containing ethyleneoxy, diethyleneoxy, triethyleneoxy, propyleneoxy, dipropyleneoxy or tripropyleneoxy groups; bromonorbornyl (meth) acrylate, dibromonorborn Nyl (meth) acrylate, dibromodicyclopentanyl (meth) acrylate, dibromotricyclopentanyl (meth) acrylate, difuromotetracyclopentanyl (meth) acrylate and their ester alcohol moieties have the formula (V) or (VI )of
Examples of An include those containing an ethyleneoxy, diethyleneoxy, triethyleneoxy, propyleneoxy, dipropyleneoxy or tripropyleneoxy group.

These monomers can be used alone,
Other main polymerizable monomers may be used in combination for improving the strength and adjusting the refractive index. The solid monomer can be used by dissolving it in another liquid copolymerizable monomer for easy handling during polymerization. Examples of the copolymerizable monomer include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, cyclohexyl (meth) acrylate, and dicyclopentanyl (meth) acrylate. (Meth) acrylic acid esters of aliphatic, alicyclic or aromatic alcohols or phenols having 1 to 25 carbon atoms, styrene, p-methylstyrene, α-methylstyrene, (meth) acrylic acid, maleic anhydride, acrylonitrile ,
Ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetradeca ethylene glycol di (meth) acrylate, tetraethylene di (meth) acrylate, nonaethylene di (meth) acrylate, 1, Examples thereof include 3-butanediol di (meth) acrylate, 1,4-butanediol di (meth) acrylate and neopentyl glycol di (meth) acrylate. The copolymerizable monomer is used in an amount of less than 70% by weight, preferably less than 50% by weight, based on the whole monomers used. If it is more than this, it becomes difficult to obtain a high refractive index.

The monomer can be used only as a monomer, but it is usually used as a monomer containing a part of the polymer, which is usually called a syrup because of improvement in polymerization activity and ease of handling. Is preferred.

The syrup is obtained by dissolving 1 to 40% by weight of a polymer in a monomer or partially polymerizing the monomer.

As the radical polymerization initiator, peroxides are preferable, and peroxyesters and hydroperoxides are particularly preferable because of high polymerization activity. Examples of peroxyesters include t-butylperoxy-3,5,5-trimethylhexanoate and t-butylperoxy-3,5,5-trimethylhexanoate.
Butyl peroxyacetate, t-butyl peroxybenzoate and the like are used. Hydroperoxides include t-butyl hydroperoxide, cumene hydroperoxide, diisopropylbenzene hydroperoxide, p-menthane hydroperoxide, 2,5-dimethylhexane-2,5-dihydroperoxide, 1,1, 3,3-Tetramethylbutyl hydroperoxide or the like is used. The amount used is monomer or syrup
0.05 to 5 parts by weight is used with respect to 100 parts by weight. If it is less than 0.05 parts by weight, the polymerization is not sufficiently carried out and a large amount of the monomer remains in the produced polymer, which is not preferable. On the other hand, if the amount is more than 5 parts by weight, the polymerization is difficult to control, and the weather resistance and heat resistance of the obtained polymer are lowered, which is not preferable.

The reducing substance containing sulfur in the molecule used in the present invention forms a redox system with a radical polymerization initiator, and is composed of at least one selected from sulfinic acid esters, thioureas and mercaptans. A divalent or tetravalent sulfur compound, specifically, methyl p-toluenesulfinate, methyl p-toluenesulfinate, tetramethylthiourea, dibutylthiourea, lauryl mercaptan, t-dodecyl mercaptan, octyl mercaptan, butyl mercaptan, Examples include 2-ethylhexyl thioglycolate, pentaerythritol tetrathioglycolate, glycol dimethylcaptoacetate, 2-mercaptoethanol and its esters, β-mercaptopropionic acid and its esters. Reducing substances containing sulfur in the molecule are monomer or syrup 100
It is used in an amount of 0.1 to 5 parts by weight, and if it is less than 0.1 parts by weight, the polymerization will be slow, and if it is more than 5 parts by weight, the resulting polymer will be colored and the strength will be decreased, such being undesirable.

Examples of the hydrogen halide salt of amine or quaternary ammonium halide used in the present invention include n-amylamine, n-hexylamine, n-octylamine, n-decylamine, laurylamine, palmitylamine, dibutylamine, Tributylamine, N, N-dimethylbenzylamine, N, N-dimethyl-p-toluidine, phenethyldibutylamine, N, N, N ', N'-tetramethylhexamethylenediamine, N, N, N', N ' -Amine hydrochloride or hydrobromide such as tetramethylpropylenediamine, N, N-diethylbenzylamine, N, N-dibutylbenzylamine, phenethyldiethylamine, tetramethylammonium chloride, benzyltrimethylammonium chloride, benzyltriethylammonium chloride, benzyl Tributylammoni Mukuroraido,
Examples include trioctylmethylammonium chloride, β-phenethyldibutylethoxycarbonylmethylammonium chloride and the like.

The amount of these compounds used is 0.005 to 1 part by weight, preferably 0.01 to 0.5 part by weight, based on 100 parts by weight of the monomer or syrup. If the amount used is less than 0.005 parts by weight or more than 1 part by weight, the polymerization rate becomes slow, which is not preferable.

When these compounds are soluble in the monomer to be used, they are used as they are, and when they are insoluble, they are dissolved in a solvent such as isopropanol, dimethyl phthalate or diethylene glycol before use.

The copper-containing compound used in the present invention acts as a decomposition catalyst for the polymerization initiator, and is a copper salt of an organic acid soluble in the monomer used, a copper-containing complex, etc., such as copper naphthenate and copper acetylacetonate. Etc. The amount used is 0.0005 to 10 ppm, preferably 0.01 to 5 ppm, in terms of copper, based on the weight of the monomer or syrup. If the amount used is less than 0.0005ppm, the polymerization rate will be slow, and the polymerization time will be unstable.
If it is more than 10 ppm, the polymerization initiator is inactivated and the polymerization is inhibited, which is not preferable.

Various polymerization methods can be used for the polymerization of the present invention, and among them, bulk polymerization, particularly cast polymerization, can be preferably used.
Cast polymerization is a radical polymerization initiator in a monomer or a monomer containing the polymer, a reducing substance containing sulfur in the molecule, a copper-containing compound and a hydrogen halide salt of a specific tertiary amine or A liquid composition in which a quaternary ammonium halide is dissolved is poured into a mold to polymerize and mold. At this time, each component may be added individually to be polymerized, but in this case, since the polymerization reactivity is extremely high, uniform mixing and uniform reaction are difficult. For this reason, the radical polymerization initiator, the reducing substance containing sulfur in the molecule and the copper-containing compound are dissolved in advance by separately dissolving a part of the monomer including the monomer or the polymer thereof in advance. It is preferable that a predetermined amount of each of them be mixed and polymerized.

Although the method of the present invention can be carried out at room temperature, it is preferably carried out at a temperature of 50 ° C. or higher in order to promote polymerization. A monomer containing a monomer or a polymer thereof and a polymerization initiator may be put in a mold to heat the mold to a temperature of 50 ° C. or higher for polymerization, and the temperature of the mold may be adjusted in advance. At a predetermined temperature of 50 ° C. or higher, a monomer or the like and a polymerization initiator or the like may be put in a mold and polymerized.

The mold used in the method of the present invention is preferably made of metal from the viewpoint of strength, ease of heat removal and the like.

The method of the present invention can be applied to molding any optical material.

That is, in the method of carrying out the polymerization in the mold of the present invention, molded products of various shapes can be obtained by changing the mold.

Examples of the optical material include a general-purpose lens, a Fresnel lens, an optical disc, a prism, and a mirror.

〔The invention's effect〕

According to the method of the present invention, by using a specific redox polymerization initiator system, it is possible to extremely rapidly complete the polymerization of a certain unsaturated monomer containing chlorine or bromine in the molecule, and transparent, A resin having a high refractive index, excellent mechanical and thermal properties, and a small amount of residual monomer can be efficiently produced.

〔Example〕

 Hereinafter, the present invention will be described in more detail with reference to Examples.

The refractive index in the examples was measured with an Abebe refractometer at 25 ° C.
The haze value was measured according to ASTM D 1003. In addition, the yellowness is measured by Japan Precision Optics SEP-H-2D type Poic integrating sphere HTR.
It measured using the meter. The total light transmittance was measured using each of A, G, and B filters, and the yellowness was calculated from the following formula.

Yellowness = 100 × (A−B) / G In the formula, A, B, and G represent the total light transmittance of each filter.

The residual monomer of the polymer was quantified by gas chromatography after extraction with acetone.

Example 1 36 g of methyl methacrylate in a 200 ml glass container, 10 g
Tetradecaethylene glycol dimethacrylate was added and 54 g of tribromophenyl methacrylate was dissolved. After tribromophenyl methacrylate was dissolved, 0.96 g of t-butyl peroxybenzoate and phenethyldibutylamine hydrochloride were added to dimethyl phthalate at 8% by weight.
1g, glycol dimercaptoacetate 0.6g, and copper naphthenate (Cu content 10%) 0.01g dissolved in methylmethacrylate in 1% by weight were added and mixed, then 160 × 160 × 3 mm It was poured into a mold and polymerized in a water bath at 85 ° C. Polymerization and curing were completed in 2.4 minutes, and a colorless and transparent cured product was obtained.

The polymer had a refractive index of 1.56, a haze value of 0.5, and a yellowness of 2.0.

Comparative Example 1 10 350 g of methyl methacrylate in an autoclave,
1500 g of tribromophenyl methacrylate, 150 g of methyl acrylate, and 6 g of azobisisobutyronitrile were added and mixed and dissolved at room temperature for 30 minutes.

Add 12 g of disodium phosphate to 6,000 g of 0.1% sodium polymethacrylate aqueous solution, and further add to the aqueous phase, and react with vigorous stirring at 85 ° C for 2 hours, then at 100 ° C for another 1
The reaction was carried out at 120 ° C. for 1 hour, and the polymer was obtained after cooling, dehydration and drying. This polymer was heated at 260 ° C using a 40 mmφ extruder.
After pelletizing, the mixture was injection molded at 260 ° C.

The obtained molded product had a very poor transparency with a haze value of 20 and a yellowness of 25, and was colored yellow. The tribromophenyl methacrylate-based polymer obtained by injection molding was not usable as an optical material.

Example 2 Polymerization was carried out in the same manner as in Example 1 except that 28 g, 5 g and 67 g were used instead of 36 g of methyl methacrylate, 10 g of tetradecaethylene glycol dimethacrylate and 54 g of tribromophenyl methacrylate, respectively. The polymer had a refractive index of 1.57, a haze value of 0.6, and a residual monomer content of 1.8%.

Comparative Example 2 Tribromophenyl methacrylate 67g Methyl methacrylate 28g Tetradecaethylene glycol dimethacrylate 5g N, N'-azobisisobutyronitrile 0.12g After the above composition was mixed and dissolved, it was placed in a mold of 160 x 160 x 3 mm. The mixture was placed therein, polymerized at 80 ° C for 1 hour, and then left at 120 ° C for 1 hour.

The obtained polymer had 9.1% residual monomer and had a strong odor and could not be used.

Example 3 To 1,000 g of p-bromophenyl methacrylate, 0.07 g of N, N'-azobisisobutyronitrile was placed in a reactor, and polymerization was carried out at 80 ° C with gentle stirring. Immediately after the liquid in the reactor became about 1 poise, it was immediately cooled with ice water to obtain a syrup having a viscosity of 1 poise.

0.92 g of cumene hydroperoxide in 95 g of the above p-bromophenyl methacrylate syrup and 5 g of tetraethylene glycol dimethacrylate, 1 g of phenethyldibutylamine hydrochloride dissolved in 8% by weight of dimethylphthalate, 0.4 g of glycol dimercaptoacetate,
Copper naphthenate (C _U content 10%) in methyl methacrylate 1
Dissolved in weight% 0.04g After mixing and mixing 160 × 16
It was poured into a 0 × 3 mm mold and polymerized in a water bath at 85 ° C.
Polymerization and curing were completed in 2 minutes, and a transparent polymer was obtained.

The polymer had a refractive index of 1.59 and a haze value of 0.4.

Example 4 100 g of dibromostyrene, 0.96 g of t-butylperoxybenzoate, 1 g of phenethyldibutylamine hydrochloride dissolved in 8% by weight of dimethylphthalate, 0.7 g of glycol dimercaptoacetate, copper naphthenate (C _U content
0.2% of 0.1% by weight dissolved in 0.1% by weight of methyl methacrylate was added and mixed, and then poured into a mold of 150 × 150 × 3 mm and polymerized in a water bath at 65 ° C. Polymerization was completed in about 3 minutes to obtain a polymer.

The refractive index of the polymer was 1.66, and the haze value was 1.0.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yukio Koushiro 5-1 Sokai-cho, Niihama-shi, Ehime Sumitomo Chemical Co., Ltd. (56) Reference JP-A-59-136309 (JP, A) JP-A-SHO 59-136310 (JP, A) JP-A-59-136311 (JP, A)

Claims (1)

[Claims] 1. At least one selected from the group consisting of a styrene derivative containing chlorine or bromine in the molecule, a methacrylic acid ester containing chlorine or bromine in the molecule, and an acrylate ester containing chlorine or bromine in the molecule. (1) Radical polymerization initiator, (2) Reducing substance containing sulfur in the molecule, (3) Amine hydrogen halide salt Alternatively, a method for producing a resin having excellent optical properties, which comprises polymerizing in the presence of a quaternary ammonium halide and a (4) copper-containing compound.