JPS63280713A - Production of high nitrile resin composition - Google Patents

Abstract

PURPOSE:To obtain the titled composition of high heat distortion temperature with no discoloration, easy to process, suitable as a packaging material, by polymerization of a monomer mixture of specified composition containing an unsaturated nitrile monomer in the presence of a conjugated diene rubbery polymer. CONSTITUTION:The objective composition can be obtained by polymerization, in the presence of (A) 1-30pts.wt. of a conjugated diene rubbery polymer, of 100pts.wt. of a monomer mixture made up of (B) 60-90wt.% of an unsaturated nitrile monomer [pref., (meth)acrylonitrile], (C) 20-5wt.% of an acrylic alkyl ester (pref., methyl acrylate) and (D) 10-0wt.% of a 1-4C methacrylic alkyl ester (pref., methyl methacrylate) in an aqueous medium. The conjugated diene monomer constituting the component A is pref. 1,3-butadiene.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for producing a high nitrile resin composition.

More specifically, the present invention relates to a method of polymerizing a mixture of an unsaturated nitrile monomer and an acrylic acid alkyl ester and a methacrylic acid alkyl ester monomer in the presence of a conjugated diene rubber-like polymer in an aqueous medium.

[Conventional technology]

Rubber-modified high nitrile polymers are thermoplastic polymers that have not only the high gas and vapor barrier properties and excellent solvent resistance that nitrile resins inherently have, but also have Ji impact resistance. It is attracting attention as a container and packaging material for cosmetics and other fields.

A typical method for producing such a rubber-modified high nitrile polymer is to add acrylonitrile 7 to a conjugated diene rubber.
0wt$ or more and unsaturated carboxylic acid ester 30-tχ
A method of producing the monomer by graft polymerization (Japanese Patent Publication No. 46-25005) is mentioned. The polymer obtained by this method has excellent gas barrier properties and impact resistance, and can be used as any container or packaging material by known molding methods, but its use is limited due to its low heat distortion temperature. There was a problem.

Various methods have been proposed to improve this problem.For example, a method of grafting acrylonitrile and α-methylstyrene onto rubber (USP 2908661);
α-methylstyrene/methylmethacrylate/acrylonitrile copolymer and rubber with methylmethacrylate,
There are compositions with graft polymers obtained by graft polymerizing styrene and acrylonitrile (Japanese Patent Publication No. 37415/1982). Although heat resistance has been improved to some extent by replacing α-methylstyrene and methyl methacrylate with conventional resin components, it is still insufficient and its applications are limited. Improvements in the resin system have been desired.

Previously, the present inventors disclosed a method for polymerizing an unsaturated nitrile, methyl acrylate, and a maleimide monomer in the presence of a conjugated diene rubber-like polymer, and a composition thereof (Japanese Patent Application No. 1983-1982).
No. 183037). However, although the heat resistance was improved, there were limitations in terms of application due to the coloring of the resin.

[Problem that the invention seeks to solve]

An object of the present invention is to provide a method for producing a high nitrile resin composition that has a high heat distortion temperature and is free from coloration.

[Means for solving problems]

That is, the present invention provides monomers of unsaturated nitrile monomers, acrylic acid alkyl esters, and other monomers copolymerizable therewith in the presence of 1 to 30 parts by weight of a conjugated diene rubber-like polymer. When 100 parts by weight of the monomer composition is polymerized in an aqueous medium, a methacrylic acid alkyl ester having 1 to 4 carbon atoms is used as the other copolymerizable monomer, and the monomer composition is 1, unsaturated. Nitrile JIL polymer 60-90 parts by weight2, acrylic acid alkyl ester 20-5 parts by weight3
, methacrylic acid alkyl ester having 1 to 4 carbon atoms
This is a method for producing a high nitrile resin composition characterized in that the content is 20 to 5 parts by weight.

The unsaturated nitrile monomer used in the present invention includes:
Examples include acrylonitrile, methacrylonitrile, α-chloroacrylonitrile, α-fluoroacrylonitrile, and the like. Preferred are acrylonitrile and methacrylonitrile.

The amount of unsaturated nitrile monomer used is 60-90%
, the production amount is 65 to 85% by weight. If the amount of the unsaturated nitrile monomer used is more than the above range, heat resistance will deteriorate, and if it is less than the above range, gas barrier properties will deteriorate. Among them, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, ethylhexyl acrylate and the like are used, with methyl acrylate and ethyl acrylate being preferred. The amount of acrylic acid alkyl ester used is 20 to 5
If the amount used in terms of weight percent is more than the above range, heat resistance will be poor, and if it is less than the above range, processability will be poor.

Examples of the methacrylic acid alkyl ester monomer having 1 to 4 carbon atoms used in the present invention include methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, and preferably methyl methacrylate. The amount of the methacrylic acid alkyl ester monomer having 1 to 4 carbon atoms used is 20 to 5% by weight; if the amount added is greater than this range, processability will be poor, and if it is less than this range, heat resistance will be poor.

The conjugated diene monomer used in the present invention is 1.3
Examples include butadiene, isoprene, chloroprene, bromoprene, etc., and 1.3-butadiene and isoprene are preferred. Monomers that can be copolymerized with conjugated diene monomers include unsaturated nitrites, aromatic vinyls, and unsaturated carboxylic acid esters. Examples of aromatic vinyls include styrene, α-methylstyrene, and vinyltoluenes. , vinylxylenes, etc., preferably styrene and α-methylstyrene, and unsaturated carboxylic acid esters include:
Methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, amyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, amyl methacrylate, α-methyl acrylate, α-chloro Ethyl acrylate is preferred, and ethyl acrylate, methyl acrylate, ethyl methacrylate, and methyl methacrylate are preferred.

The amount of conjugated diene monomer used is 50% by weight or more,
When the amount is less than this, impact resistance deteriorates.

The amount of the conjugated diene-based rubbery polymer used in the present invention is determined by adjusting the physical properties depending on the purpose of production, as the impact strength increases as the relative proportion of the rubber component in the composition increases, but the gas barrier properties decrease. The amount of rubber obtained may be sufficient, but in terms of -FC, it is 1 to 30 parts by weight per 100 parts by weight of the monomer mixture,
Preferably it is 5 to 25 parts.

The conjugated diene rubber-like polymer used in the present invention is prepared by removing oxygen in an aqueous medium in the presence of an emulsifier or dispersant, a polymerization initiator, a molecular weight regulator, a pH regulator, and other additives. Obtained by polymerizing at a desired temperature. The monomer and other auxiliary raw materials may be added in a batch manner, a continuous manner, or a divided manner. The particle size of the obtained rubber is 50~
It is 250μ. When polymerizing monomers in the presence of a conjugated diene-based rubbery polymer, polymerization initiators (or catalysts) that can be used include peracid catalysts such as persulfuric acid, peracetic acid, and perphthalic acid, and potassium persulfate. There are persalt catalysts such as hydrogen peroxide, benzoyl peroxide, chlorobenzoyl peroxide, peroxide catalysts such as acetyl peroxide, lauryl peroxide, dicumyl peroxide, and azo catalysts such as azobisisobutyronitrile. , these can be used alone or in a mixture of two or more.

A preferred polymerization method in the present invention is an aqueous emulsion polymerization method,
Emulsifiers that can be used include sodium and potassium salts such as myristic acid, lauric acid, palmitic acid, oleic acid and stearic acid; sodium, potassium and ammonium salts such as lauryl sulfate, cetyl sulfate, oleyl sulfonic acid and stearyl sulfonic acid; These include higher amine salts such as laurylamine hydrochloride and stearylamine hydropromide, and polymeric substances such as polyvinylpyrrolidone, sodium polyacrylate, and methylcellulose.

The polymer product is obtained in the form of a latex, and the polymer is coagulated by a conventionally known method, such as a coagulation method using an electrolyte or a solvent, or a freezing method, and then washed with water and dried to obtain a polymer.

It is also possible to add plasticizers, stabilizers, lubricants, dyes and pigments, fillers, etc. during or after the polymerization, if necessary.

〔Example〕

The present invention will be explained below with reference to Examples.

In the examples, "parts" and "%" are based on weight.

Production side of conjugated diene rubber-like polymer A mixture consisting of the following components was heated in a stainless steel polymerization reactor to remove oxygen, and the conversion rate of monomers was 90% at 45°C above and below INN.
Polymerization was carried out until

The solid content concentration of the chemically converted latex was 30.3%.

Acrylonitrile 30 parts 1,3-butadiene 70 parts Fatty acid soap
2.4 parts Azobisisobutyronitrile 0.3 parts t-dodecyl mercaptan 0.5 parts Water 200 parts Example 1 Production example of graft polymer Using the conjugated diene-based rubbery polymer obtained in Production Example Aqueous emulsion polymerization was carried out using raw materials consisting of the following components.

Water 235 parts Acrylonitrile 75 parts Methyl acrylate 10 parts Methyl methacrylate 15 parts Conjugated diene rubber polymer 10 parts Polyvinylpyrrolidone 0.5 parts Sodium hexametaphosphate 0.2 parts Potassium persulfate 0.05 parts t-dodecyl mercaptan 1.6 parts First, 10 parts by weight of a conjugated diene-based rubbery polymer was charged into a stainless steel polymerization reaction system, then one-fifth of the other components except dodecyl mercaptan were added, and after oxygen was removed, the temperature was raised to 58°C. Polymerization was started.

Thirty minutes after the start of polymerization, the remaining components were continuously added over a period of 9 hours. After the continuous addition was completed, polymerization was continued for an additional hour until the final monomer conversion was 92%.

The obtained latex was mixed with an aluminum sulfate aqueous solution (concentration 4
5%) was added to solidify the mixture, which was further washed with water and dried to obtain a white powdery polymer. This polymer was heated at 170℃ and weighed at 140 kg.
/- to obtain a transparent pale yellow sheet. Yel lowness In of the test piece made from this sheet
dex (according to JIS K-7130) was measured. In addition, in order to examine the processability of the polymer, the melt index (according to AST?101238) was measured. moreover,
The heat distortion temperature (IIDT) was measured according to ASTM D64B. The results are shown in Table 1.

Examples 2-3 In Example 1, 65 parts of acrylonitrile bond, 8
The reaction was carried out in the same manner as in Example 1 except that the amount was changed to 5 parts.

The results are shown in Table 1.

Comparative Example 1 Polymerization was carried out in the same manner as in Example 1, except that all methyl methacrylate in Example 1 was changed to methyl acrylate. The results are shown in Table 1.

Comparative Example 2 Polymerization was carried out in the same manner as in Example 1, except that all methyl acrylate in Example 1 was changed to methyl methacrylate. The results are shown in Table 1.

Examples 4 to 5 In the production examples, the amount of conjugated diene rubbery polymer was 7 parts,
Polymerization was carried out in the same manner as in Example 1, except that the amount was changed to 15 parts. The results are shown in Table 1.

Example 6 Polymerization was carried out in the same manner as in Example 1, except that methyl methacrylate was changed to ethyl methacrylate.

The results are shown in Table 1.

Comparative Example 3 In the production example, the amount of conjugated diene rubber-like polymer was 40
Polymerization was carried out in the same manner as in Example 1, except that the parts by weight were changed. The results are shown in Table 1.

From Table 1, the polymer obtained by the method of the present invention has a high heat distortion temperature and excellent processability.

<Effects of the Invention> The polymers produced by the method of the present invention can be molded into a wide variety of useful articles by any of the known molding methods used for thermoplastics, such as extrusion molding, injection molding, blow molding, etc. The polymer composition of the present invention, which is a thermoformable and easily processable thermoplastic, has excellent solvent resistance, impact resistance and low permeability to gases and vapors, as well as excellent heat resistance, and is suitable for use in bottles. It is useful as a packaging container material, such as films, sheets, pipes, and other types of containers for liquids and solids. Furthermore, when used as a packaging material, heat filling and heat sterilization are possible, expanding the range of applications and making a great contribution to industry.

Claims (3)

[Claims] (1) Monomer composition of an unsaturated nitrile monomer, an acrylic acid alkyl ester, and other monomers copolymerizable with these in the presence of 1 to 30 parts by weight of a conjugated diene rubber polymer. When polymerizing 100 parts by weight of the compound in an aqueous medium, a methacrylic acid alkyl ester having 1 to 4 carbon atoms was used as the other copolymerizable monomer, and the monomer composition was 1, unsaturated nitrile monomer. A method for producing a high nitrile resin composition characterized by comprising: 60 to 90% by weight of acrylic acid alkyl ester, 20 to 5% by weight of acrylic acid alkyl ester, and 10 to 0% by weight of methacrylic acid alkyl ester having 1 to 4 carbon atoms. . (2) The high nitrile resin composition according to claim 1, which comprises adding part or all of the monomer composition and part or all of the aqueous medium and water, either continuously or in portions. How things are manufactured. (3) The conjugated diene rubber-like polymer contains 50% by weight or more of a conjugated diene monomer and 50% by weight of other monomers copolymerizable therewith.
% or less by weight, the method for producing a high nitrile resin composition according to claim 1.