KR19980056790A - Method for producing acrylonitrile-butadiene-styrene (ABS) resin having excellent thermal stability and impact resistance - Google Patents

Abstract

In the present invention, in preparing ABS resin by mixing SAN and lubricant with ABS graft polymer, 20 to 50 parts by weight of styrene monomer, 30 to 50 parts by weight of acrylonitrile monomer, 30 to 60 parts by weight of polybutadiene, and oxidation-reduction It is prepared by a semi-continuous emulsion radical polymerization method using 0.2 to 1.0 parts by weight of an initiator, 0.4-2 parts by weight of an emulsifier, and 0.1 to 0.5 parts by weight of a molecular weight modifier, and 0.1 to dibenzoyl peroxide, which is a polymerization initiator, by a combination of redox initiators. The present invention provides a method for producing acrylonitrile-butadiene-styrene resin having excellent thermal stability and impact resistance, comprising 0.5 parts by weight of ferrous sulfate, 4-sodium pyrophosphate, and dextrose. ABS thermoplastic resin produced by the method has excellent thermal stability and high impact resistance at high temperature, and is suitable for engineering of industrial goods such as electrical and electronic products. Application development is possible with plastic.

Description

Method for preparing acrylonitrile-butadiene-styrene (ABS) resin having excellent thermal stability and impact resistance

The present invention relates to a method for producing an acrylonitrile-butadiene-styrene (ABS) resin having excellent thermal stability and impact resistance, and more specifically, an ABS resin is kneaded by mixing an ABS graft polymer and styrene-acrylonitrile (SAN). In preparing the present invention, the present invention relates to a method for producing an ABS resin having excellent impact resistance and thermal stability at high temperature, using a combination of specific acid reduction initiators.

ABS resin is acrylonitrile-butadiene-styren copolymer, which has excellent mechanical and thermal properties including impact resistance, chemical resistance, heat deformation, etc. It is widely used in the field of rigid molded products from daily necessities such as electric and electronic products and automobile parts to industrial goods.

ABS resin is generally produced by an emulsion polymerization process, and is prepared by graft copolymerization of styrene and acrylonitrile on polybutadiene. In relation to such ABS resins, research is being actively conducted to improve functionality through simplification of the product through loss reduction and process time, as well as control of the component ratio, graft ratio, and molecular weight of Samsung. On the other hand, in order to further improve the heat resistance and impact resistance of the ABS resin, improvements have been attempted such as replacing one or two components of the existing ABS monomer with a new monomer or improving the graft polymerization method. Problems such as poor workability, prolongation of polymerization time, lower impact resistance, and the like have been demanded.

The present inventors polymerize by conventional emulsion radical polymerization method in order to enhance the thermal stability and impact strength of ABS resin, and control the selection of the appropriate polymerization initiator among the oxidation-reduction initiator, its content and the timing of introduction, Emulsion stabilizers are prepared for the type and content of stabilizers and complete dispersion in the latex of the stabilizers to maximize the effectiveness, improve productivity, and improve impact strength and thermal stability with uniform dispersion of antioxidants. It was found that the present invention was completed.

That is, in the present invention, in preparing an ABS resin by adding SAN and a lubricant to a graft ABS graft polymer, 20 to 50 parts by weight of styrene monomer, 30 to 50 parts by weight of acrylonitrile monomer, and 30 to 60 parts by weight of polybutadiene , Prepared by the semi-continuous emulsion radical polymerization method using 0.2-1.0 parts by weight of redox initiator, 0.4-2 parts by weight of emulsifier, and 0.1-0.5 parts by weight of molecular weight regulator, and is a combination of oxidation and reduction initiators. Dibenzoyl peroxide 0.1 to 0.5 parts by weight of ferrous sulfate, 4-sodium pyrophosphate, using a thing consisting of mextrose, and excellent thermal stability and impact resistance, characterized in that the dibenzoyl peroxide is added twice. It is to provide a method for producing a ronitrile-butadiene-styrene (ABS) resin.

Hereinafter, the present invention will be described in more detail.

In the present invention, the polymerization proceeds in two stages by dividing the polymerization initiator into two, but when the polymerization initiator of the total amount of the total amount is used in a batch-type polymerization, the coagulation in latex increases and the production yield decreases, so it is added twice. However, it is necessary to put the primary at the beginning of polymerization and the secondary at 60 to 80 ° C.

Typical polymerization initiators include water-soluble initiators such as potassium persulfate and ammonium persulfate or cumene hydroperoxide, t-butylhydroperoxide, isocumyl hydroperoxide, t-butyl perbenzoate, t-butylperacetate, and lauryl hydride. Fat-soluble initiators, such as a loperoxide, are used. However, the fat-soluble initiator has a long half-life and has a disadvantage of slowing down the polymerization rate and has a chromophore that may have a color during polymerization, thereby increasing the yellowness of the ABS graft polymer.

In addition, loryl hydroperoxide is not preferable because the half-life is short, but the production of the copolymer is superior to the graft polymerization during polymerization. Therefore, in this invention, 0.1-0.5 weight part dibenzoyl peroxide is used as a polymerization initiator.

In the present invention, as the oxidation-reduction initiator, in addition to the polymerization initiator, ferrous sulfate, 4-sodium pyrophosphate, dextrose and the like can be used. Such a combination of redox initiators can significantly improve the impact strength and thermal stability of the final product.

In the present invention, when the amount of the dibenzoyl peroxide polymerization initiator is less than 0.1 part by weight, the polymerization rate is slow and the amount of the residual monomer is increased. On the contrary, when the amount of the dibenzoyl peroxide polymerization initiator is less than 0.5 part by weight, the effect is less than the amount used, and yellowing may occur due to the initiator.

In preparing acrylonitrile-butadiene-styrene ABS resins according to the present invention, a mixture of an aromatic vinyl monomer and an unsaturated nitrile monomer in the presence of 30 to 60 parts by weight (based on solids) of butadiene rubber latex having an average particle diameter of 0.25 to 0.30 microns 70 It is preferable to graft-polymerize -40 weight part.

In the present invention, when the average particle diameter of the diene rubber is less than 0.25 micron, the impact resistance is lowered. When the average particle diameter is more than 0.30 micron, the impact resistance is improved, but the coagulation is increased due to the decrease in the polymerization stability.

In the present invention, when the amount of butadiene rubber latex is less than 30 parts by weight, the efficiency of graft polymerization production of rubber latex is lowered. On the contrary, when the amount of butadiene rubber latex exceeds 60 parts by weight, it is difficult to recover the fine powder during solidification drying of the graft latex. The problem that the appearance and gloss of the deterioration occurs.

Monomers usable in the present invention include aromatic vinyl monomers such as styrene, alphamethylstyrene, alphaglostyrene, vinyltoluene, divinylbenzene, pt-butylstyrene, 2,4-dimethylstyrene, acrylonitrile, methacryl Unsaturated monomers, such as ronitrile, etc. are mentioned. Among these, 1 type, or 2 or more types chosen from styrene, acrylonitrile, and methacrylonitrile are preferable. The amount of the monomer used is 0 to 15 parts by weight in the one step reaction and 35 to 20 parts by weight in the two step reaction. When the first and second graft monomers are used in a smaller amount than the above range, the impact resistance and hardness of the resin are reduced.

As the emulsifier usable in the present invention, those used in conventional emulsion polymerization may be used, for example, potassium dihydroavitate, sodium laurate, sodium oleate, potassium oleate, sodium lauryl sulfate, potassium preliminary Steel sulfate, sodium naphthalene sulfonate, sodium isopropyl naphthalene sulfonate, and the like. Among them, one or two or more emulsifiers selected from potassium dihydroavitate, potassium oleate, sodium oleate and sodium lauryl sulfate are preferable. In the present invention, the amount of emulsifier used is 0.4 to 2 parts by weight, when the amount of emulsifier used is less than 0.4 part by weight, the coagulum in the latex is excessively generated during polymerization, and when the amount is more than 2 parts by weight, impact resistance is caused by excessive generation of non-graft polymer. This is lowered and an increase in the amount of residual emulsifier results in discoloration of the final graft ABS.

In this invention, it is preferable to use molecular weight modifiers, such as a C8-18 mercaptan or an organic halogen compound, as a molecular weight modifier. The amount of the molecular weight modifier used is 0.1 to 0.5 parts by weight. If the amount is less than 0.1 parts by weight, the thermal stability of the graft ABS powder is drastically decreased. When the amount is more than 0.5 parts by weight, the yellowness of the ABS is increased and the molecular weight is rapidly increased. Lowers the tensile strength.

After the polymerization is completed, an emulsion solution of antioxidant, which is a stabilizer, is added to stabilize the residual peroxide and the ABS in the subsequent process. In the present invention, as the antioxidant, a combination solution of a phenolic antioxidant excellent in radical elimination effect and a thioester-based combination solution having excellent storage stability in low temperature processing conditions and in the presence of oxygen is used. 4'-thiobis (3-methyl-6-t-butylphenol) is 0.05 to 1.5 parts by weight based on 100 parts by weight of ABS graft polymer latex, ditridecyl 3,3'-thiodipropionate which is a thioester Emulsion mixture prepared by mixing 0.5 to 2.5 parts by weight is used as an antioxidant. If the antioxidant is used at less than 0.05 parts by weight, the thermal stability is lowered, and when used in excess of 2.5 parts by weight, the thermal stability of the graft ABS is increased, but there is a disadvantage that the discoloration is severe during injection stay. The latex into which the antioxidant is added is cooled to room temperature, and then poured into a coagulation bath containing 0.5% to 1.5% sulfuric acid aqueous solution to prepare an ABS graft polymer.

ABS thermoplastic resin having excellent thermal stability may be manufactured by adding a predetermined amount of SAN and a lubricant to the graft ABS powder thus prepared.

The ABS thermoplastic resin produced by the method of the present invention is excellent in thermal stability at high temperatures and excellent in impact resistance, and thus can be used as an engineering plastic for industrial goods such as electrical and electronic products.

Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited by the following Examples.

Example 1

100 parts by weight of pure water, 0.8 parts by weight of potassium salt of dihydroabitic acid (solid content of 25%), 50 parts by weight of polybutadiene latex (52% of solid content), 10 parts by weight of styrene monomer, and 5 parts of acrylonitrile in the reactor Parts, 0.2 parts by weight of tertiary dodecyl mercaptan, which is a molecular weight regulator, 0.3 parts by weight of dextrose, and 0.12 parts by weight of dibenzoyl peroxide, a polymerization initiator, increase the temperature to 60 ° C. while stirring, and then add 4-sodium pyrophosphate to 3 parts by weight of pure water. 0.1 parts by weight of ferrous sulfate and 0.003 parts by weight of a mixed solution were added to the reactor, and then heated to 70 ° C., 25 parts by weight of styrene monomer, 10 parts by weight of acrylonitrile, 0.1 parts by weight of tertiary dodecyl mercaptan, and dibenzoyl peroxide. 0.21 part by weight was continuously added. The prepared g-ABS latex was composed of antioxidant 2,2'-methyllinbis (4-methyl-6-t-butylphenol) and ditridecyl 3.3'-thiodipropionate based on 100 parts by weight of g-ABS latex. 0.1 parts by weight of the mixed emulsion solution was introduced and cooled to room temperature.

ABS graft latex was continuously added to a reactor loaded with a 1% sulfuric acid solution and coagulated with stirring at 200 rpm. The mixture was cooled to room temperature, washed, and dried for 1 hour in a hot air dryer, followed by extrusion into a pellet form by adding 30 parts by weight of ABS graft polymer, 70 parts by weight of SAN, and 0.4 parts by weight of a metal lubricant to prepare an ABS resin. Subsequently, the specimens were injected with physical properties and the physical properties were measured. The results are shown in Table 1 below.

Example 2

Except that the content of the polymerization initiator dibenzoyl peroxide was changed to 0.135 parts by weight of the primary, 0.21 parts by weight of the secondary and in the same manner as in Example 1 and measured the physical properties and the results are shown in Table 1 together.

Comparative Example 1

In Example 1, except that Cumanhadirroperoxide was used as the polymerization initiator, and the content was 0.1 parts by weight and 0.21 parts by weight, the same procedure as in Example 1 was carried out, and the physical properties were measured. It is shown together in Table 1 below.

Comparative Example 2

Except for using t-butyl hydroperoxide as a polymerization initiator was carried out in the same manner as in Example 1 and measured the physical properties and the results are shown in Table 1 together.

Comparative Example 3

Except for using t-butyl peroxy acetate as a polymerization initiator was carried out in the same manner as in Example 1 and measured the physical properties and the results are shown in Table 1 together.

[Measurement Method]

Izod impact strength (Kgcm / cm): ASTM D256 (1/4)

R-HD (Rockwell Strength): ASTM D785

VST (bicket softening temperature; ℃): ASTM D1925

ΔE (color difference): ASTM D1925

YI (yellow) and WI (white): ASTM D1925

Through Table 1, in the case of the ABS resin produced by the present invention it can be seen that the impact resistance is much superior to the conventional ABS resin and also excellent in whiteness.

Claims (3)

In preparing ABS resin by mixing SAN and lubricant with ABS graft polymer, 20 to 50 parts by weight of styrene monomer, 30 to 50 parts by weight of acrylonitrile monomer, 30 to 60 parts by weight of polybutadiene, and 0.2 to 0 redox initiators 1.0 part by weight, emulsifier 0.4-2 part by weight, and 0.1 to 0.5 part by weight of a molecular weight regulator are prepared by the semi-continuous emulsion radical polymerization method, but 0.1 to 0.5 part by weight of dibenzoyl peroxide, a polymerization initiator, by a combination of redox initiators. And ferrous sulfate, 4-narcium pyrophosphate, and dextrose, the method for producing acrylonitrile-butadiene-styrene resin having excellent thermal stability and impact resistance. According to claim 1, wherein dibenzoyl peroxide, the polymerization initiator, divided into two times, the first is put into the initial polymerization, the second is 60 to 80 ℃ excellent acrylic and excellent thermal stability and impact resistance Process for the preparation of nitrile-butadiene-styrene (ABS) resins. The method according to claim 1, wherein 0.05 to 1.5 parts by weight and 3,3 'of ditridecyl are added based on 100 parts by weight of 4,4'-thiobis (3-methyl-6-t-butylphenol) ABS graft polymer latex after polymerization. -0.05 to 2.5 parts by weight of an emulsion solution prepared by mixing 0.5 to 2.5 parts by weight of thiodipropionate, wherein the acrylonitrile-butadiene-styrene resin is excellent in thermal stability and impact resistance.