JPH09124738A - Styrene-acrylic resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a styrene-acrylic resin compsn. excellent in moldability and light transmission properties. SOLUTION: This compsn. comprises a copolymer obtd. by copolymerizing a free-radical-polymerizable monomer component comprising a styrene compd. and (meth)acrylonitrile and/or a (meth)acrylic ester in the presence of a free- radical-polymn. initiator and a chain transfer agent for free-radical polymn. represented by the formula: Q[(CO)p -O-(CO)q -A-Z]m (wherein Q is a polyvalent org. group; A is a 1-8C alkylene; Z is a chain transfer group; (p) and (q) are each 0 or 1 provided they are not simultaneously 1; and (m) is an integer of 2-100 provided structures in m brackets may be the same or different from each other).

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a styrene-acrylic resin composition. More specifically, the present invention relates to a styrene-acrylic resin composition having a narrow molecular weight distribution, excellent moldability, and excellent light transmittance.

[0002]

2. Description of the Related Art Styrene-acrylic resins obtained by copolymerization of styrene with (meth) acrylonitrile or (meth) acrylic acid ester have a light-transmitting property and are therefore used for transparent plastic moldings and the like. There is.
However, in terms of styrene / acrylonitrile copolymer,
A weight ratio of 75/25 is the azeotropic composition. From this, in the prior art, (meth) acrylonitrile content is low, and since it is difficult to produce a styrene-acrylic resin having a high light transmittance in a high yield, when a high light transmittance is required, The (meth) acrylonitrile content was usually 25 to 35% by weight.

[0003]

However, in recent years, there has been an increasing demand for diversification of light-transmissive resins, and the light-transmissive resins pursue various improvements in various performances and physical properties depending on the purpose of use. Need to let. As the light-transmitting resin, there are polycarbonate resin, SMA resin, MS resin and the like in addition to styrene-acrylic resin, and various requirements are satisfied by compounding these light-transmitting resins or modifying the resin. Consideration is in progress. When compounding different types of resin, the point is not to lower the compatibility and light transmittance, so the light-transmitting resin to be compounded has a high light transmittance and the range of choices to obtain compatibility is high. The wider is preferable. The present invention has been made under such a background. That is, an object of the present invention is to newly obtain a styrene-acrylic resin having a high light transmittance despite a low (meth) acrylonitrile content.

[0004]

The present inventors have arrived at the present invention as a result of extensive studies on a styrene-acrylic resin composition having a narrow molecular weight distribution by radical polymerization.
That is, the present invention provides a radical polymerizable monomer comprising styrenes (A) and (meth) acrylonitrile (B) and / or (meth) acrylic acid esters (C),
A styrene-acrylic resin composition comprising a copolymer (D) obtained by copolymerization in the presence of a radical polymerization initiator and a chain transfer agent for radical polymerization represented by the following general formula (1). General formula {In the formula, Q is a polyvalent organic group, A is an alkylene group having 1 to 8 carbon atoms, Z is a chain transfer group, p and q are 0 or 1 respectively, and p and q are not 1 at the same time, m is 2-10
It represents an integer of 0, and the values in [] may be the same or different. ｝

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, examples of the styrenes (A) include styrene, α-methylstyrene, t-butylstyrene, dimethylstyrene, acetoxystyrene, vinyltoluene and the like. Also,
(Meth) acrylonitrile (B) is acrylonitrile or methacrylonitrile. Examples of the (meth) acrylic acid ester (C) include methyl (meth) acrylate, butyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, undecyl (meth) acrylate, dodecyl (meth) acrylate, Tridecyl (meth) acrylate, tetradecyl (meth) acrylate, pentadecyl (meth) acrylate, hexadecyl (meth) acrylate, octadecyl (meth) acrylate, eicosyl (meth) acrylate, docosyl (meth) acrylate, etc.], hydroxypolyoxyalkylene ether mono (Meth) acrylates and the like can be mentioned.

In the general formula (1), Q is a residue obtained by removing OH from polyhydric alcohol or polyhydric phenol,
Examples thereof include a residue obtained by removing COOH from a polycarboxylic acid. As the polyhydric alcohol, alkylene glycol having 2 to 8 carbon atoms (ethylene glycol, propylene glycol, 1,3- and 1,4-butanediol, 1,6
-Hexanediol, neopentyl glycol, etc.),
Dihydric alcohols such as diols having a cyclic group and having 5 to 10 carbon atoms; 3 carbon atoms such as glycerin, trimethylolpropane, trimethylolethane and hexanetriol
~ 12 trihydric alcohol; 4 to 20 carbon atoms such as pentaerythritol, methylglycoside, diglycerin, etc.
Alcohols having a higher number of functional groups, such as pentitols (adnitol, arabitol, xylitol, etc.), hexitols (sorbitol, mannitol, iditol, taritol, dulcitol, etc.), sugars [sucrose, monosaccharides (glucose, mannose, etc.). , Fructose, sorbose, etc.), oligosaccharides (crehalose, lactose, raffinose, etc.)]; glucosides [eg polyols (glycol,
Glucosides of glycerin, trimethylolpropane, alkanepolyols such as hexanetriol); polyalkanepolyols [eg polyglycerin such as triglycerin, tetraglycerin]; polypentaerythritol (dipentaerythritol, tripentaerythritol, etc.); cycloalkanepolyols [Tetrakis (hydroxymethyl) cyclohexanol etc.] and the like can be mentioned. Further, polyvinyl alcohol having a degree of polymerization of up to 100 can be used.

Further, di- and triethanolamine; alkylamines having 2 to 20 carbon atoms, 2 to 6 carbon atoms
Alkylenediamines such as ethylenediamine, propylenediamine, hexamethylenediamine, polyalkylenepolyamines such as aliphatic amines such as diethylenetriamine, triethylenetetramine, aniline, phenylenediamine, diaminotoluene, xylylenediamine, methylenedianiline, diphenyletherdiamine, etc. Examples thereof include alicyclic amines such as group amines, isophoronediamine, cyclohexylenediamine, and dicyclohexylmethanediamine, and alkylene oxide adducts such as aminoethylpiperazine.

Examples of polyhydric phenols include monocyclic polyhydric phenols such as pyrogallol, hydroquinone and phloroglucin; bisphenols such as bisphenol A and bisphenol sulfone; condensates of phenol and formaldehyde (novolak) and polyphenols.

As the polyvalent carboxylic acid, divalent carboxylic acid [(1) aliphatic dicarboxylic acid having 2 to 20 carbon atoms (maleic acid, fumaric acid, succinic acid, adipic acid, sebacic acid, malonic acid, azelaic acid, Mesaconic acid, citraconic acid, glutaconic acid, etc.); (2) Alicyclic dicarboxylic acid having 8 to 20 carbon atoms (cyclohexanedicarboxylic acid, methylmedic acid, etc.); (3) Aromatic dicarboxylic acid having 8 to 20 carbon atoms (phthalate) Acid, isophthalic acid, terephthalic acid, toluenedicarboxylic acid, naphthalenedicarboxylic acid, etc.);
(4) Alkyl or alkenyl succinic acid having a hydrocarbon group having 4 to 35 carbon atoms in the side chain (isododecenyl succinic acid, n-dodecenyl succinic acid, etc.), trivalent or higher carboxylic acids [(1) carbon number 7 to 20 aliphatic polycarboxylic acids (1,2,4-butanetricarboxylic acid, 1,2,5
-Hexanetricarboxylic acid, 1,3-dicarboxylic acid-
2-methyl-2-methylenecarboxypropane, tetra (methylenecarboxyl) methane, 1,2,7,8-octanetetracarboxylic acid, etc.); (2) carbon number 9-20
Alicyclic polycarboxylic acids (e.g., 1,2,4-cyclohexanetricarboxylic acid); (3) aromatic polycarboxylic acids having 9 to 20 carbon atoms (1,2,4-benzenetricarboxylic acid, 1,2,5 -Benzenetricarboxylic acid, 2,5,7
-Naphthalene tricarboxylic acid and 1,2,4-naphthalene tricarboxylic acid, pyromellitic acid, benzophenone tetracarboxylic acid, etc.)] and the like. Further, an unsaturated polycarboxylic acid polymer having a degree of polymerization of up to 100 can be mentioned.

In the general formula (1), Z is SH,
SR, SSR, CX ₃ (R is an alkyl, aryl, aralkyl, alkoxy, aryloxy or cycloalkyl group having 1 to 20 carbon atoms, which may be substituted with a halogen atom, an alkyl group, a cyano group or a nitro group. Is a chlorine atom, a bromine atom.) And the like. Of these, SH is preferred.

In the general formula (1), p is 0 when Q is a polyhydric alcohol or polyhydric phenol residue, and p is 1 when it is a polyhydric carboxylic acid residue. In the general formula (1), m is preferably 2-8. It is also preferable that p and q are 0 at the same time.

The chain transfer agent represented by the general formula (1) is Z
When is SH, it can be manufactured by the following method, for example. Chain Transfer Agent 1 (when p is 0 and q is 0) The alkylene glycol ether of a polyhydric alcohol is chlorinated at its terminal with thionyl chloride or the like, and then reacted with alkali hydrosulfide. Further, the ω-mercapto-alkyl alcohol and the polyhydric alcohol are etherified. Specific chain transfer agents include ethylene glycol-di-2-mercaptoethyl ether, trimethylolpropane-tri-2-mercaptoethyl ether, pentaerythritol-tetra-2-mercaptoethyl ether and the like.

Chain Transfer Agent 2 (when p is 1 and q is 0) ω-mercapto-alkyl alcohol and polyvalent carboxylic acid are esterified. Specific chain transfer agents include maleic acid-di-2-mercaptoethyl ester, fumaric acid-di-2-mercaptoethyl ester, adipic acid-di-2-mercaptoethyl ester, terephthalic acid-di-
2-mercaptoethyl ester and the like can be mentioned.

In the production of the above compound, it is possible to co-add a cyclic ether and a cyclic lactone,
When co-adding, either random co-adding or block co-adding may be used. Examples of cyclic ethers include ethylene oxide, propylene oxide, butylene oxide, epichlorohydrin, and styrene oxide, examples of cyclic thioethers include episulfide, and examples of cyclic imines include ethyleneimine. These may be co-added, and when co-added, either random co-addition or block co-addition may be performed. Of these, preferred are cyclic ethers, and more preferred are ethylene oxide, propylene oxide and mixtures thereof. Examples of the cyclic lactone include ε-caprolactone and δ-valerolactone, and examples of the cyclic lactam include ε-caprolactam. These may be co-added, and when co-added, either random co-addition or block co-addition may be performed.

As long as the above conditions are satisfied, the structure of the polymer can be arbitrarily selected depending on the properties of the polymer to be obtained. For example, in terms of the compound 1, the cyclic ether to be added is preferably propylene oxide in order to obtain a styrene resin.

The amount of the chain transfer agent used in the present invention is usually 0.01 to 20% by weight, preferably 0.1 to 10%, particularly preferably 0.1 to 5%, based on the monomers. is there.

Known initiators can be used for the polymerization, and examples thereof include water-soluble azo initiators (azobisamidinopropane (salt), azobiscyanovaleric acid (salt), etc.) and oil-soluble azo. Initiators (azobiscyanovaleronitrile, azobisisobutyronitrile, azobiscyclohexanecarbonitrile, etc.), water-soluble peroxides (hydrogen peroxide, peracetic acid, etc.), oil-soluble peroxides (benzoyl peroxide, cumene) Hydroxy peroxide, etc.), inorganic peroxides (ammonium persulfate, sodium persulfate, etc.) and the like. A redox initiator system may be formed with a peroxide and a reducing agent as described above, and examples of the reducing agent include bisulfite (sodium bisulfite, potassium bisulfite,
Ammonium bisulfite, etc.), tertiary amines (dimethylaminobenzoic acid (salt), dimethylaminoethanol, etc.), amine complexes of transition metal salts (pentamethylenehexamine complex of cobalt (III) chloride, diethylenetriamine complex of copper (II) chloride) Etc.) etc. Further, an azo initiator, a peroxide initiator, or a redox initiator may be appropriately used in combination. The amount of the polymerization initiator is usually 0.01 to 10% by weight, preferably 0.05 to 5% by weight, based on the radically polymerizable monomer.

In the method for producing the polymer of the present invention, the polymerization method may be any of solution polymerization, emulsion polymerization, suspension polymerization and bulk polymerization. As the solvent in the case of solution polymerization, water,
Alcohols (methanol, ethanol, isopropanol, etc.), ketones (acetone, methyl isobutyl ketone, etc.), ethers (tetrahydrofuran, etc.), aliphatic hydrocarbons (hexane, heptane, etc.), aromatic hydrocarbons (toluene, xylene) Etc.), halogenated solvents (ethylene dichloride, etc.) and mixtures thereof.

The polymerization temperature is usually 50 to 300 ° C.,
Preferably it is 100-250 degreeC. For solution polymerization,
Examples of the temperature include a temperature lower than the boiling point of the polymerization solution under normal pressure, a boiling point of the polymerization solution under normal pressure, and a temperature higher than the boiling point of the polymerization solution under pressure. Further, when a dispersion medium, an emulsifier, a dispersant, etc. are used, there is no particular limitation and known ones can be used.

The number average molecular weight of the copolymer obtained by the production method of the present invention is usually 1,000 to 500,000, preferably 3,000 to 500,000. The molecular weight distribution is usually 1.20 to 3.00, preferably 1.20.
2.50. The molecular weight distribution depends on the polymerization system,
Compared with the case where the chain transfer agent of the present invention is not used, it becomes much narrower. Here, the molecular weight distribution is (weight average molecular weight /
Number average molecular weight).

The light transmittance of the styrene-acrylic resin of the present invention is usually 85% or more, preferably 90% or more.

Since the styrene-acrylic resin of the present invention has a high light-transmitting property, it can be used for eyeglass lenses, contact lenses, image-reading lenses for copying machines and fax machines, and CDs.
-It is useful as an optical material such as a pickup lens and an optical fiber optical disk substrate.

[0023]

EXAMPLES The present invention will be further described with reference to the following examples, but the present invention is not limited to these examples. Parts in the examples are parts by weight. The method for measuring the number average molecular weight and the molecular weight distribution by GPC is as follows. Machine type: HLC-8120 (manufactured by Tosoh) Column: TSK gel Super H4000 + TSK gel Super H3000 + TSK gel Super H2000 (both manufactured by Tosoh) Column temperature: 40 ° C Detector: RI solvent: Tetrahydrofuran sample concentration: 0.25 weight % Injection volume: 10 μl Standard: Polystyrene

(Production of Chain Transfer Agent) Production Example 1 150 parts of triethylene glycol was charged into a reaction vessel,
With stirring, 262 parts of thionyl chloride was added dropwise at 80 ° C. over 2 hours. After maintaining the same temperature for 1 hour, 500 parts of a 30% sodium hydrosulfide aqueous solution was added dropwise over 3 hours.
After holding at the same temperature for 1 hour, the temperature was returned to room temperature, liquid separation was performed, and ethylene glycol-di-2-mercaptoethyl ether 18
0 parts were obtained. This is designated as chain transfer agent A.

Example 1 A flask equipped with a stirrer, a reflux condenser, two dropping funnels, a thermometer and a gas inlet was charged with 250 parts of styrene, 50 parts of acrylonitrile, 800 parts of DMF and 1 part of a chain transfer agent A, and stirred under nitrogen. After replacement, the temperature was raised to 80 ° C. A mixture of 700 parts of styrene, 1 part of chain transfer agent A and 100 parts of tetrahydrofuran was added dropwise from one dropping funnel at the same temperature over 6 hours, and 5 parts of azobisisobutyronitrile was simultaneously added from the other dropping funnel. And 200 parts of tetrahydrofuran were added dropwise over 7 hours. After holding at the same temperature for 3 hours, the solvent and unreacted monomers were distilled off to obtain 980 parts of a styrene-acrylonitrile resin (hereinafter abbreviated as AS resin-1). The acrylonitrile content in this resin was 5.0%, the number average molecular weight was 23,500, and the molecular weight distribution was 1.7.

Comparative Example 1 A styrene-acrylonitrile resin (hereinafter referred to as AS resin-2) was prepared in the same manner as in Example 1 except that the chain transfer agent A was not used.
Abbreviated). The acrylonitrile content in this resin was 4.2%, the number average molecular weight was 23,000, and the molecular weight distribution was 2.9.

Example 2 Ethylene chloride 4 was placed in a flask equipped with a stirrer, a reflux condenser, two dropping funnels, a thermometer and a gas inlet.
00 parts and 5 parts of the chain transfer agent A were charged, the atmosphere was replaced with nitrogen with stirring, and the temperature was raised to 80 ° C. 500 parts of styrene and 50 acrylonitrile from one dropping funnel at the same temperature under a nitrogen stream.
Parts, 150 parts of methyl methacrylate and chain transfer agent A
1.5 parts of the mixture was added dropwise over 5 hours, and simultaneously, a mixture of 6 parts of di-tert-butyl peroxide and 200 parts of xylene was added over 6 hours from the other dropping funnel. After being kept at the same temperature for 3 hours, the solvent and unreacted monomers were distilled off, and styrene-acrylonitrile-methyl methacrylate resin (hereinafter abbreviated as AMS resin-1) 690
Got a part. The number average molecular weight in this resin is 13,500,
The molecular weight distribution was 1.8.

Comparative Example 2 A styrene-acrylonitrile-methyl methacrylate resin (hereinafter referred to as AMS resin-2) was prepared in the same manner as in Example 1 except that the chain transfer agent A was not used and 10 parts of di-tert-butyl peroxide was used. (Abbreviated as) 690 parts were obtained. The number average molecular weight in this resin was 12,000 and the molecular weight distribution was 3.1.

Test Examples 1-2, Comparative Test Examples 1-2 AS resin-1, AS resin-2, AMS resin-1 and A
MS resin-2 is molded to a thickness of 3 mm, according to JIS
According to the test method of K7105, the light transmittance and haze of the resin were measured using an integrating sphere light transmittance measuring device. Table 1 shows the evaluation results.

[0030]

[Table 1]

[0031]

INDUSTRIAL APPLICABILITY The present invention is a copolymer of styrenes and (meth) acrylonitrile, which has a high light transmittance even though the content of (meth) acrylonitrile is low.
This is to newly provide an acrylic resin. Since the styrene-acrylic resin of the present invention has high light transmittance, it is useful as an optical material for eyeglass lenses, contact lenses, image reading lenses for copying machines and fax machines, CD-pickup lenses, optical fiber optical disk substrates and the like. is there. Further, the styrene-acrylic resin of the present invention is blended with other transparent resins such as polycarbonate resin, SMA resin, MS resin, etc., without impairing the light transmittance thereof by changing the (meth) acrylonitrile content. It is possible to use low birefringence optical materials, etc.
It can also be used as a material for new composite materials.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Yoshimi Iida, 1-11, Hitotsubashi-honcho, Higashiyama-ku, Kyoto City, Sanyo Chemical Industry Co., Ltd. Within the corporation

Claims (7)

[Claims] 1. A radical polymerizable monomer comprising a styrene (A) and a (meth) acrylonitrile (B) and / or a (meth) acrylic acid ester (C), a radical polymerization initiator and the following general compound. A styrene-acrylic resin composition comprising a copolymer (D) obtained by copolymerization in the presence of a chain transfer agent for radical polymerization represented by the formula (1). General formula {In the formula, Q is a polyvalent organic group, A is an alkylene group having 1 to 8 carbon atoms, Z is a chain transfer group, p and q are 0 or 1 respectively, and p and q are not 1 at the same time, m is 2-10
It represents an integer of 0, and the values in [] may be the same or different. ｝ 2. The resin composition according to claim 1, wherein Z in the general formula (1) is SH. 3. The resin composition according to claim 1, wherein p and q are 0 in the general formula (1). 4. The resin composition according to claim 1, wherein styrene is 70% by weight or more as a constitutional unit in the copolymer (D), and light transmittance is 85% or more. . 5. The copolymer (D) has a number average molecular weight of 1,0.
0 to 500,000 and the molecular weight distribution is 1.2 to
It is 3.0, The resin composition in any one of Claims 1-4. 6. The resin composition according to claim 1, wherein the amount of the chain transfer agent is 0.01 to 20% by weight based on the radically polymerizable monomer. 7. The resin composition according to claim 1, which is for an optical material selected from the group consisting of eyeglass lenses, contact lenses, copying machines, fax machines, CD-pickup lenses and optical fiber optical disk substrates.