KR940011156B1 - Method of producing a heat resistant copolymer - Google Patents

Abstract

The heat resistant copolymer having a good latex stability is produced by emulsion-polymerizing a mixt. of 50-80 wt.pts. alpha-methylstyrene, 1-5 wt.pts. styrene, 10-30 wt.pts. vinyl cyane cpd., 0.1-7 wt.pts. alpha,beta-unsatd. carboxylic acid, 0.1-1 wt.pt. ethylenic unsatd. amide, 0.1-10 wt.pts. (meth)acrylic acid alkyl ester, 0.2-0.4 wt.pt. polymerization initiator, and 1-4 wt.pts. emulsifier. The initiator is pref. an oxidizing-reducing agent. The heat resistant acrylonitrile- butadiene-styrene (ABS) resin having a good a impact resistance and moldability, and a good heat stability at a high temp. is produced by blending the copolymer with the ABS polymer.

Description

Method of producing a heat resistant copolymer

The present invention relates to a method for producing a heat-resistant copolymer having excellent latex stability and heat resistance, and to kneading the heat-resistant copolymer with an ABS polymer, to producing a heat-resistant ABS resin having excellent heat resistance, impact resistance and moldability, and excellent thermal stability at high temperature. will be.

Acrylonitrile-butadiene-styrene (hereinafter referred to as ABS) resin has impact resistance, chemical resistance, processability, and surface gloss but lacks heat resistance, so that the use in the electric, electronic, or automotive fields is extremely limited. Therefore, various methods have been used to improve the heat resistance of the ABS resin, but present many problems.

For example, Japanese Patent Laid-Open Nos. 58-206657, 59-135210, and 59-184243 describe a method of adding N-phenylmaleide to an ABS resin to improve heat resistance, which processability of the resin This has a disadvantage in that the poor and the impact strength is reduced.

U.S. Patent Nos. 3010936 and 465790 disclose a method of improving the heat resistance by copolymerizing ABS resin with α-methyl styrene, but this method also improves the heat resistance of the resin, but polymerization conversion, latex stability, formability, and thermal stability at high temperatures. This shows a problem of deterioration.

In addition, there is a method of blending the ABS resin with the polycarbonate, but in order to increase the heat deformation temperature to about 120 ℃ has the disadvantage that the workability is lowered because the content of the polycarbonate must be maintained at 40 to 60% by weight of the total resin, In addition, the method of filling the inorganic material is used, but this method can also increase the heat deformation temperature to 99 to 116 ℃ by filling the inorganic filler with 20 to 40 parts by weight of the total resin, but the heat effect is less than the filling amount and the impact resistance is lowered There is a disadvantage.

The present inventors have diligently studied to solve such problems and use α, β-unsaturated carboxylic acids, ethylenically unsaturated amides, acrylic acid alkyl esters or methacrylic acid alkyl esters for α-methylstyrene, styrene and vinylcyanide compounds. When the emulsion polymerization was carried out to produce a heat-resistant copolymer having a polymerization conversion of 97% or more, a solid coagulation content of 35% or more, and a glass transition temperature of 140 ° C or more, and the heat-resistant copolymer prepared above was made of ABS having a high molecular weight. The present invention has been completed by kneading with a graft polymer to produce a heat resistant thermoplastic resin having a heat deformation temperature of 110 ° C. or more and an Izod impact strength of 15 or more.

Therefore, the present invention is 50 to 80 parts by weight of α-methyl styrene, 1 to 5 parts by weight of styrene, 10 to 30 parts by weight of a vinyl cyan compound, 0.1 to 7 parts by weight of α, β-unsaturated carboxylic acid, 0.1 ethylenically unsaturated amide To 1 part by weight, 0.1 to 10 parts by weight of an acrylic acid alkyl ester or methacrylic acid alkyl ester, 0.2 to 0.4 parts by weight of an oxidizing agent and 1 to 4 parts by weight of an emulsifier in the oxidation-reducing agent initiator It relates to a method for producing a copolymer and to kneading the heat resistant copolymer with an ABS resin to produce a heat resistant ABS resin having excellent moldability and impact resistance.

Hereinafter, the present invention will be described in detail.

In the present invention, the method of emulsion polymerization is a method of adding each component as a method of collectively administering a total amount of each component, or a method of continuously administering a total amount or a part of the present invention. Take the complex form you use.

That is, in the present invention, 75 to 90% by weight of the total weight of the monomers are initiated in a batch and then reacted at a temperature of 55 to 65 ° C for 1 to 2 hours, and then 8 to 22% by weight of the total weight of the monomers is 65 to 80 ° C. After continuous administration at 2 ° C. for 2 to 5 hours, the remaining monomer and the initiator are administered to prepare an heat resistant copolymer by emulsion polymerization for 1 to 2 hours.

Menacrylic acid, acrylic acid or itaconic acid is used as alpha, beta -unsaturated carboxylic acid, and methyl methacrylate is used as methacrylic acid alkyl ester. In addition, methacrylamide is used as ethylenic unsaturated amide.

As an emulsifier, sodium salts or potassium salts of rosin acid and higher fatty acids, sodium salts and potassium salts of alkyl benzene sulfonic acid, etc. are used alone or in combination thereof.

Polymerization catalysts include peroxides such as persulfate, disopropyl benzene hydroperoxide, cumene hydroperoxide, sodium formaldehyde sulfoxylate, sodium ethylene diamine tetraacetate, ferrous sulfate, dextrose, sodium pyrrolate, An oxidation-reduction catalyst in a mixture with a reducing agent such as sodium sulfate is used. When using an oxidation-reducing agent catalyst, the amount of the oxidizing agent therein is 0.2 to 0.4 parts by weight based on 100 parts by weight of the total monomers.

As the molecular weight regulator, tertiary dodecyl mercaptan is used, and is used in an amount of 0.6 parts by weight or less per 100 parts by weight of the total monomers.

After completion of the polymerization, the polymerization conversion was 95% or more, and the latex obtained was dried by solidifying with an aqueous calcium chloride solution at 120 ° C.

30 to 50 parts by weight of the heat-resistant copolymer prepared above and the ABS graft polymer latex are kneaded, and the latex is solidified with an aqueous calcium chloride solution at 100 to 120 ° C., dehydrated and dried to prepare a heat-resistant ABS resin in powder form, or Coagulated latex alone, coagulated, dehydrated and dried to form a powder, kneaded with 30 to 60 parts by weight of this powder and a general ABS resin and a general SAN (styrene-acrylonitrile copolymer) to 16 to 23% by weight of total rubber And an antioxidant and other light stabilizers are administered as necessary to prepare a heat resistant ABS resin.

Examples are described to illustrate the invention, but the invention is not so limited.

In the examples, the solids content and the product coagulant weight may be obtained from the following formulas.

When the resultant coagulant weight was 0.5% or more, the stability of the prepared latex was extremely poor, which was not suitable for the purpose of the present invention.

Example A1

In Table 1, one-step components of the composition ratio A1, that is, 100 parts by weight of ion-exchanged water, 2.0 parts by weight of sodium alkylbenzenesulfonate (emulsifier A) as an emulsifier, 0.8 parts by weight of sodium rosinate (emulsifier B), α-methylstyrene Oxidation composed of 72 parts by weight, 1 part by weight of styrene, 11 parts by weight of acrylonitrile, 0.4 part by weight of tertiary dodecyl mercaptan (T-DDM) as a molecular weight regulator, 0.2 part by weight of potassium persulfate and 0.15 part by weight of sodium sulfite The reducing agent catalyst was batch administered at 45 ° C. and reacted for 1 hour and 30 minutes while raising the reaction temperature to 65 ° C. Thereafter, the two-stage components of the composition ratio A1, i.e., 60 parts by weight of ion-exchanged water, 0.4 part by weight of emulsifier A, 10 parts by weight of acrylonitrile, methacrylic acid, methacrylamide and methyl methacrylate, respectively, and 1 part by weight of T-DDM 0.2 parts by weight of the emulsion mixture and 0.1 parts by weight of persulfate as an initiator were mixed and continuously administered at 70 ° C. for about 2 hours. After raising the polymerization temperature to 75 ° C., as an emulsified mixture and initiator with three components of composition ratio A1, that is, 10 parts by weight of ion-exchanged water, 0.1 part by weight of emulsifier A, 2 parts by weight of acrylonitrile, and 1 part by weight of methyl methacrylate. 0.05 parts by weight of high sulfate was mixed and administered in a batch and then reacted for 1 hour and 30 minutes, and then aged for 1 hour. After the reaction was completed, the solid content (%) of the latex prepared by using an infrared lamp was measured, and the weight of product coagulant (%) was measured to determine the polymerization conversion rate and stability. In addition, the prepared latex was coagulated with an aqueous calcium chloride solution at around 120 ° C., washed and dried, and then the glass transition temperature was measured by DSC (differential scanning heat analyzer). The results are shown in Table 1.

Examples A2 to A10

The same method as in Example 1 was carried out, but the composition ratio of A2 to A10 was used instead of A1 in Table 1, respectively. The results are shown in Table 1.

[Comparative Examples 1 and 2]

The same method as in Example 1 was carried out, but the composition ratio was used as the composition ratio of Comparative 1 and 2 in Table 1. The results are shown in Table 1.

TABLE 1

[Example B1]

The heat-resistant copolymer latex prepared in Example A1 or the powder prepared by coagulating the latex was kneaded with the powder prepared by coagulating ABS graft polymer latex to prepare a heat resistant ABS resin. 60 parts by weight of heat-resistant copolymer latex A1 and 40 parts by weight of ABS graft polymer (Lucky Co., Ltd. DP210) were kneaded, coagulated, washed and dried to prepare a powder form. 0.4 parts by weight of lubricant and 100 parts by weight of antioxidant 0.4 parts by weight and 0.2 parts by weight of the UV stabilizer was administered and extruded using a twin screw kneader at a cylinder temperature of 250 to 260 ° C. to prepare pellets. Specimens were prepared using this pellet and measured for physical properties.

[Examples B2 to B10]

Using the composition ratio B2-B10 of Table 2, the method similar to the said use example B1 was implemented. The results are shown in Table 2.

TABLE 2

Claims (9)

In preparing a heat resistant copolymer by emulsion-polymerizing a monomer composition composed of α-methylstyrene, styrene, vinyl cyanide compound, α, β-unsaturated carboxylic acid, ethylenically unsaturated amide and acrylic acid alkyl ester or methacrylic acid alkyl ester, ) 75-90% by weight of the total weight of the monomers are reacted by batch administration with an initiator and an emulsifier; 2) continuously administering 8 to 22% by weight of the total weight of the monomers; 3) A method for producing a heat resistant copolymer characterized in that the residual monomers are emulsion polymerized by administering an initiator. The method of claim 1, wherein the α, β-unsaturated carboxylic acid monomer is methacrylic acid, acrylic acid or itaconic acid. The method of claim 1, wherein the menacrylic acid alkyl ester monomer is methyl methacrylate. The method of claim 1, wherein the ethylenically unsaturated amide monomer is a methacryl amide. The method of claim 1 wherein the emulsifier is an alkyl sulfonate or a mixture thereof with a rosin acid salt. The method of claim 1, wherein the initiator is an oxidation-reducing catalyst. According to claim 1, α-methylstyrene 50 to 80 parts by weight, styrene 1 to 5 parts by weight, vinyl cyan compound 10 to 30 parts by weight, α, β-unsaturated carboxylic acid 0.1 to 7 parts by weight, ethylenically unsaturated amide 0.1 to 1 part by weight, 0.1 to 10 parts by weight of an acrylic acid alkyl ester or methacrylic acid alkyl ester, 0.2 to 0.4 parts by weight of an initiator and 1 to 4 parts by weight of an emulsifier. According to claim 1, the reaction of 1) is carried out for 1 to 2 hours at a temperature of 55 to 65 ℃, the administration process of 2) is carried out over 2 to 5 hours at a temperature of 65 to 80 ℃, 3) Emulsification polymerization of the method characterized in that carried out for 1 to 2 hours. A method for improving the heat resistance of an ABS resin, wherein the heat resistant copolymer prepared according to the method of claims 1 to 8 and a known ABS resin are kneaded.