JPH09268246A - Styrene-based resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject composition containing a specified amount of a specific graft copolymer, excellent in impact strength, low in luster unevenness, having good platability, and useful for motor vehicle parts, etc.

SOLUTION: This composition comprises (A) 5-90wt.% of a graft copolymer produced by bulk copolymerization or solution copolymerization of (iii) 100 pts.wt. of a monomer mixture composed of 80-40wt.% of styrene monomer, 15-50wt.% of an acrylonitrile-based monomer and 0-40wt.% of a monomer copolymerizable therewith in the presence of (i) 0.1-10 pts.wt. of a rubbery graft copolymer 0.05-0.8μm in weight-average particle size and (ii) 0.1-10 pts.wt. of an acrylic copolymer (B) 95-10wt.% a graft compolymer produced by emulsion graft copolymerization of 50-15 pts.wt. of the component (iii) in the presence of 50-85 pts.wt. of a butadiene-based rubber 0.05-0.8μm in weight-average particle size, and (C) 0-80wt.% of a copolymer produced by copolymerization of the component (iii).

COPYRIGHT: (C)1997,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a styrene resin composition. More specifically, the present invention relates to a styrenic resin composition having excellent impact strength, less uneven gloss, and good plating properties.

[0002]

2. Description of the Related Art Conventionally, styrene resins (eg, ABS resin) have been widely evaluated for molding processability, physical properties, and mechanical properties, and are therefore widely used in electric and electronic products and vehicle parts. . However, general ABS resin still has some points to be improved in impact strength and glossiness. Especially, when the molding process is performed, the gloss unevenness is remarkable in the product, or the gloss changes when the angle is changed even in the same place. This is not desirable for the appearance of the product because it causes a large difference in gloss.

On the other hand, ABS resin has good moldability, is lightweight, and has the property of being plated.
It is replacing metal materials, and is widely developed as vehicle parts and other parts requiring decorativeness and corrosion resistance.
Regarding the plating of the ABS resin, first, the butadiene-based rubber on the surface of the resin is melted by chemical etching to form a concave mark to form a rough surface, and then the ABS is put in a chemical solution to perform chemical plating. When a rough surface is formed, the metal layer to be plated enters into the concave marks and is fixed by the anchoring effect, so that the plated metal layer can be firmly fixed to the ABS resin surface.

According to the above-mentioned conventional technique, the plating layer is A
Although it can be adhered to the BS resin, after the ABS resin is plated, the plated metal layer is vulnerable to thermal cycling and has a drawback that the adhesion strength is low and the appearance is not good. In order to improve it, it has been attempted to change the injection conditions of the ABS resin to increase the injection temperature and decrease the injection speed and the injection pressure. However, although it was possible to improve the adhesion strength for the time being, it was not yet satisfactory.
In addition, when the injection temperature is high, the resin is deteriorated, and when the injection speed and the injection pressure are decreased, the production speed is decreased, which is not economically viable. Therefore, it has been found that the plating characteristics of the styrene resin cannot be effectively improved simply by changing the injection conditions.

As described above, how to give the styrene-based resin an excellent impact value, further reduce the difference in gloss of the product, and improve the heat-resistant circulation property and the adhesion strength of the plating layer is in this field. It is an issue that needs to be resolved in.

[0006]

SUMMARY OF THE INVENTION In view of the above, an object of the present invention is to provide a styrene resin composition having excellent impact strength, little difference in gloss, and good plating property.

[0007]

The present invention provides (1) a rubber-like graft copolymer (A) having a weight average particle diameter of 0.05 to 0.8 μm.
In the presence of 0.1 to 10 parts by weight (amount based on 100 parts by weight of the monomer mixture described below) and 0.1 to 10 parts by weight (amount based on 100 parts by weight of the monomer mixture described below) of the acrylic copolymer (B), 100 parts by weight of a monomer mixture consisting of 80 to 45% by weight of a styrene-based monomer, 15 to 50% by weight of an acrylonitrile-based monomer, and 0 to 40% by weight of a monomer copolymerizable therewith is subjected to bulk copolymerization or Graft copolymer (C) obtained by solution copolymerization (C) 5 to 90% by weight, (2) weight average particle diameter 0.05 to 0.8 μ
m butadiene rubber in the presence of 50 to 85 parts by weight,
Styrene-based monomer 45 to 80% by weight, acrylonitrile-based monomer 15 to 50% by weight and monomer 0 to
95 to 10% by weight of a graft copolymer (D) obtained by emulsion-copolymerizing 50 to 15 parts by weight of a monomer mixture consisting of 40% by weight, and (3) 80 to 50 parts by weight of a styrene monomer, A styrene resin containing 20 to 50 parts by weight of an acrylonitrile-based monomer and 0 to 80 parts by weight of a copolymer (E) obtained by copolymerizing 0 to 40 parts by weight of a monomer copolymerizable therewith. A composition is provided.

The rubber-like graft copolymer (A) in the present invention is 45 to 80% by weight of styrene monomer in the presence of 50 to 85 parts by weight (solid content) of butadiene rubber latex.
And acrylonitrile monomer 15 to 50% by weight and other copolymerizable monomer 0 to 40% by weight
Graft-polymerized 50 to 15 parts by weight to give a weight average particle size of 0.05
The latex of the rubber-like graft copolymer (A) having a particle size of 0.8 μm is obtained, and the latex is further obtained as powder or particles through a procedure such as coagulation, dehydration and drying.

The above-mentioned butadiene rubber latex is a homopolymer consisting of 100 to 60% by weight of a butadiene monomer and 0 to 40% by weight of a copolymerizable unsaturated monomer, or a copolymer thereof. Is. The copolymerizable unsaturated monomer is a styrene-based monomer, an acrylonitrile-based monomer, a (meth) acrylic acid ester-based monomer, or the like.

Typical examples of the butadiene rubber latex used in the present invention include polybutadiene, butadiene-styrene copolymer, butadiene-acrylonitrile copolymer, butadiene-methyl methacrylate copolymer and the like. The butadiene-based rubber latex has an average particle size of 0.05-
Set to 0.8 μm or 0.05-0.18 μm by polymerization
It is also possible to make the rubber latex having a small particle size, and then to make the rubber latex enlarged to 0.2 to 0.8 μm by a known rubber enlargement method. Examples of the rubber enlargement method include a chemical enlargement method in which an organic acid, a metal salt or a polymer flocculant having a carboxylic acid group is added, a mechanical enlargement method by mechanical stirring, or a frozen enlargement method. Examples of the polymer flocculant used in the chemical enlargement method include butyl acrylate-methacrylic acid copolymer.

The reaction of the graft polymerization for preparing the rubber-like graft copolymer (A) of the present invention is carried out in a weight average particle size of 0.05 to
For obtaining a rubber-like graft copolymer having a thickness of 0.8 μm.
A mixture of a styrene-based monomer and an acrylonitrile-based monomer and, if necessary, a monomer copolymerizable therewith, is subjected to a graft polymerization reaction. That is, the rubber-like polymer and at least one styrene-acrylonitrile-based copolymer are bonded by a grafting reaction. Usually, the ratio of the monomer to the rubber-like polymer, the polymerization conditions, the chemical structure of the rubber polymer, the rubber particle size, the addition rate of the monomer, the amount of the chain transfer agent, the amount of the emulsifier used, and their various types. A predetermined graft ratio can be obtained depending on the combination of factors.

The initiator or catalyst added to the graft polymerization reaction is usually 0.01 to 5.0 with respect to the polymerizable monomer.
In the range of wt%, preferably 0.1 to 3.0 wt%,
The addition amount is determined by the monomer and the degree of the desired polymerization reaction, and by gradually increasing the amount of the initiator, it is possible to contribute to the progress of the graft polymerization reaction.

The molecular weight of the graft copolymer can be adjusted by controlling the temperature of the graft copolymerization reaction and / or adding a very small proportion of a general molecular weight modifier. Examples of the molecular weight regulator include mercaptans, halogen compounds, terpenes and the like, and specific examples thereof include n-dodecyl mercaptan and te.
Examples include rt-dodecyl mercaptan, carbon tetrabromide, terpinolene, and 2,4-diphenyl-4-methyl-1-pentene.

Further, the graft polymerization reaction can be controlled by changing the amount of the copolymer grafted on the rubber-like polymer. Usually, this control effect is achieved by charging the monomer mixture into the polymerization reaction vessel while continuously or successively increasing the amount thereof, and more preferably by simultaneously and continuously increasing the amount of the initiator. As the initiator, it is possible to use a conventional reaction initiator for various emulsion polymerization, for example, peroxy (peroxy) and azo compounds, those addition methods, a predetermined amount all at once or continuously or You may add in steps. Suitable peroxy initiators include, for example, alkali metal peroxides, sulfate peroxides,
Examples thereof include borate peroxide, acetate peroxide, carbonate peroxide, hydrogen peroxide, etc., and also used as an oil-soluble initiator, for example, dicumyl peroxide (dic
umyl peroxide), tert-butyric peroxide (tert-buty
l-peroxide), cumene hydroperoxide
peroxide) etc.

The copolymerization reaction between the rubber latex and the monomer mixture may be carried out under stirring in an inert gas atmosphere at 20 to 100 ° C., or at a pressure of 0 to 100 psig. In order to polymerize 90% of the monomers by the reaction, a polymerization time of 2 to 10 hours is usually required, and most of them are polymerized in 4 to 8 hours.

Typical examples of the styrene-based monomer used for grafting the butadiene-based rubber in the present invention include styrene, α-methylstyrene, α-styrene chloride, p-
t-butylstyrene, p-methylstyrene, o-chlorostyrene, p-chlorostyrene, 2,5-dichlorostyrene, 3,4-dichlorostyrene, 2,4,6-tribromostyrene, 2,5-dibromo Examples thereof include styrene and divinylbenzene, and among them, styrene or α-methylstyrene is preferable.

Specific examples of the acrylonitrile monomer used for grafting the butadiene rubber include acrylonitrile and methacrylonitrile, and acrylonitrile is preferable.

The copolymerizable monomer used in the production of the rubber graft copolymer (A) in the present invention is, for example, (meth) acrylic acid ester, maleimide-based monomer, acrylic acid, maleic anhydride. and so on. here,
Examples of the (meth) acrylic acid ester-based monomer include methyl (meth) acrylate, ethyl (meth) acrylate,
Propyl (meth) acrylate, butyl (meth) acrylate, benzyl (meth) acrylate, hexyl (meth) acrylate, cyclohexyl (meth) acrylate, dodecyl (meth) acrylate, 2-hydroxy (meth) acrylate Ethyl, glycidyl (meth) acrylate, γ-
Examples thereof include (meth) acrylic dipropyltrimethoxysilane, dimethylaminoethyl (meth) acrylate, and ethylene glycol methacrylate, with methyl methacrylate being preferred.
Examples of the maleimide-based monomer include maleimide, N-methylmaleimide, N-isopropylmaleimide, N-butylmaleimide, N-hexylmaleimide,
N-octyl maleimide, N-dodecyl maleimide, N
-Cyclohexylmaleimide, N-phenylmaleimide, N-2,3-dimethylphenylmaleimide, N-
2,4-dimethylphenylmaleimide, N-2,3-diethylphenylmaleimide, N-2,4-diethylphenylmaleimide, N-2,3-dibutylphenylmaleimide, N-2,4-dibutylphenylmaleimide, N-
2,6-dimethylphenylmaleimide, N-2,3-dichlorophenylmaleimide, N-2,4-dichlorophenylmaleimide, N-2,3-dibromophenylmaleimide, N-2,4,6-tribromophenylmaleimide, etc. And preferably N-phenylmaleimide.

When the above graft copolymerization is carried out, a rubber-like graft copolymer latex having a weight average particle diameter of 0.05 to 0.8 μm is obtained. The preferred particle size is 0.06 to 0.4 μm. When the weight average particle size is less than 0.05 μm, the effect of improving the impact strength and plating adhesion strength of the resin cannot be obtained, and the tensile strength and uneven gloss also deteriorate.

An appropriate coagulant is added to the above rubber-like graft copolymer latex to coagulate it. Examples of commonly used flocculants include sulfuric acid, acetic acid, alkaline earth metal salts such as calcium chloride calcium salt, magnesium chloride, magnesium sulfate and other magnesium salts, aluminum sulfate aluminum salt, and preferably alkaline earth metal salts. Use metal salts. Water is removed by a dehydration process from the copolymer obtained after completion of coagulation,
Further, if it is dried using a dryer or an extruder, a powdery or granular rubber-like graft copolymer (A) can be obtained.

In the present invention, the graft ratio means the ratio of the copolymer of the hard portion obtained by grafting the styrene-based monomer and the acrylonitrile-based monomer to the rubber and the weight% of the rubber. If the rubber hard graft copolymer has a molecular weight of 40,000 to 120,000 and a graft ratio of 10 to 40
Within the range of%, a plated product excellent in impact strength, plating adhesion strength and appearance can be obtained.

The acrylic copolymer (B) used for producing the graft copolymer (C) is at least one selected from (meth) acrylic acid ester monomers and acrylonitrile monomers. Seed monomer 10-100
Examples thereof include copolymers composed by weight, 0-80% by weight of styrenic monomer, and 0-30% by weight of other copolymerizable monomer. Specific examples thereof include a styrene-acrylonitrile copolymer, a methyl methacrylate-styrene-acrylonitrile copolymer, a methyl polymethacrylate and a copolymer with styrene-methyl methacrylate. Examples of the polymerization method include a solution method, a block method, an emulsion method, or a suspension method.

The styrene-based monomer, the acrylonitrile-based monomer, and the (meth) acrylic acid ester-based monomer used in the above-mentioned acrylic polymer (B) are respectively the above-mentioned rubber-like graft copolymer. The same one as described in (A) can be used.

The graft copolymer (C) of the present invention comprises 0.1 to 10 parts by weight of the above rubber-like graft copolymer (A) (amount based on 100 parts by weight of the monomer mixture described below), and an acrylic copolymer. (B) 0.1 to 10 parts by weight (monomer mixture 100 described below)
(Amount relative to parts by weight) and 100 parts by weight of the following monomer mixture are copolymerized by a bulk copolymerization method or a solution copolymerization method. Here, the monomer mixture is 80 to 45% by weight of a styrene-based monomer and 15 to 15 acrylonitrile-based monomers.
50% by weight and 0 to 40% by weight of a copolymerizable monomer. After the conversion rate of the polymerization reaction reaches 40 to 90% by weight, a graft copolymer is produced by devolatilizing unreacted monomers and volatile components from the copolymer solution.

The graft copolymer (C) of the present invention can be carried out by a reactor used for continuous bulk or solution polymerization reaction. Examples of the reactor include a plug flow reactor (FPR), a complete mixing type reactor (CSTR), a static mixing type plug reactor and the like, and a complete mixing type (CSTR) reactor is preferable. Also, one reactor may be used alone, or two or more reactors may be used at the same time. When producing the graft copolymer of the present invention, a polymerization initiator can be added to the reaction, and as the polymerization initiator, acyl peroxide, ester peroxide, ketal peroxide, carbonate ester peroxide, and nitrile group and cyclohexyl can be used. Examples thereof include azo compounds. The amount of the polymerization initiator added is usually 0.01 to 1.0% by weight based on 100% by weight of the monomer.

The reaction temperature in the above reactor is 80 to 200 ° C.
The temperature is controlled to be within the range of 90 to 160 ° C. Further, the pressure of the reactor is controlled to be 1 to 5 kg / cm ² , and the time for which the raw material solution stays in the reactor is 1 to 5 hours. To control the molecular weight of the polymer, for example, t-
Chain transfer agents such as dodecyl mercaptan, n-dodecyl mercaptan and terpinolene may be used.

After the polymerization is completed, the obtained copolymer solution is usually heated by a preheater to the upper limit temperature and subjected to a devolatilization treatment to remove unreacted monomers and volatile components. As the devolatilization treatment, a degassing device such as a vacuum devolatilization tank or an extruder is usually used, and the removed volatile components are collected by a condenser to obtain a recovered liquid, and then the water content of the recovered liquid is removed. It can be used again as a raw material solution. Then, the polymerized hot melt from which the volatile matter has been removed is extruded and granulated to obtain graft copolymer pellets.

The rubber-like graft copolymer (A) used for producing the graft copolymer (C) is used in an amount of 0.1 to 10 parts by weight based on 100 parts by weight of the monomer mixture as described above.
Above all, it is preferably 0.15 to 8 parts by weight. When the amount used is less than 0.1 part by weight, the effect of improving the impact strength cannot be exhibited with respect to the resin composition, the gloss unevenness is large, and the plating adhesion strength and the heat resistance cycle are poor.
On the other hand, when the amount used is more than 10 parts by weight, a part of the dispersibility in the resin composition is not good, and defects such as fisheyes occur in the appearance of the product and the plated product.

The acrylic copolymer (B) used in the graft copolymer (C) of the present invention is added in an amount of 0.1 to 10 parts by weight per 100 parts by weight of the monomer mixture, as described above. It is preferably 0.15 to 8 parts by weight. If the amount added is less than 0.1 parts by weight, the copolymer (A) is likely to coagulate excessively, which makes it difficult to completely disperse and dissolve the copolymer in the solution, which makes it difficult to carry out the work with a pump and obtain it after the reaction. Coarse particles are also included inside the graft copolymer (C), and defects such as fish eyes occur on the surface of the resin composition and the plated product, and the effect of improving gloss unevenness and adhesion of plating is improved. Will be insufficient. Further, when the amount of the acrylic polymer (B) added is more than 10 parts by weight, the acrylic polymer (B) is excessively polymerized and reprocessed, which is economically unprofitable. The graft copolymer (C) is incorporated in the resin composition of the present invention in an amount of 5 to 90% by weight.

The styrene-based monomer, the acrylonitrile-based monomer and the copolymerizable monomer used in the production of the graft copolymer (D) of the present invention are respectively the above-mentioned rubber-like graft copolymers. The same thing as what was explained in combination (A) can be used. When the added copolymerizable monomer is a maleimide-based monomer, a resin composition having good heat resistance can be obtained. Examples of the maleimide-based monomer include N
There is phenylmaleimide.

The method for producing the above graft copolymer (D) is the same as that for the rubber-like graft copolymer (A). Both components may or may not be the same, but in order to obtain better impact strength and plating adhesion strength, the graft ratio of the graft copolymer is 18-80%, the molecular weight of the grafted hard copolymer is Is preferably 40,000 to 200,000.

The rubber particles of the graft copolymer (D) of the present invention have a weight average particle diameter of 0.05 to 0.8 μm, preferably 0.15 to.
0.5 μm. If the weight average particle size is less than 0.05 μm, a resin product having high impact resistance and good adhesion strength cannot be obtained, and if the weight average particle size is more than 0.8 μm, the tensile strength and impact strength decrease. Graft copolymer (D)
Is mixed in the resin composition of the present invention in an amount of 95 to 10% by weight.

The copolymer (E) of the present invention comprises 80 to 50 parts by weight of a styrene-based monomer, 20 to 50 parts by weight of an acrylonitrile-based monomer, and optionally 0 to 40 parts of a copolymerizable monomer. It is a copolymer of parts by weight. As the styrene-based monomer, acrylonitrile-based monomer and copolymerizable monomer, the same ones as those described above for the rubber-like graft copolymer (A) monomer can be used. The copolymer (E) is a lump,
It can be produced by solution, suspension or emulsion polymerization, preferably by bulk or solution polymerization method. As for its molecular weight
It is 60,000 to 400,000, preferably 80,000 to 300,000. The content of the copolymer (E) in the resin composition of the present invention is 0 to 80% by weight.

[0034]

BEST MODE FOR CARRYING OUT THE INVENTION In the resin composition obtained by extruding the graft copolymer (C), the graft copolymer (D) and the copolymer (E) of the present invention, the graft copolymer is added to the total amount of the resin. The content of the polymer (C) is 5 to 90% by weight,
It is preferably 10 to 80% by weight, and its content is 5% by weight
When it is lower, the effect of improving impact strength and uneven gloss is not exhibited, and the adhesion strength of the plated product is poor. On the other hand, when the content is higher than 90% by weight, the impact strength is lowered because the rubber content is insufficient. Further, the content of the graft copolymer (D) is 95 to 10% by weight, preferably the total amount of the resin.
60 to 15% by weight, and if the content exceeds 95% by weight, the rubber content is too high, resulting in poor processability of the resin and poor appearance of the plated product. On the other hand, the impact strength of the resin composition whose content is less than 10% by weight and the adhesion strength of the plated product are poor.

Further, in the present invention, the resin composition is provided with desired properties by adding an antioxidant such as phenol or mercaptopropionate, a light stabilizer and a light absorber, if necessary. You can The present invention is also a plasticizer for improving the moldability of styrene resin,
Fillers, colorants, lubricants, antistatic agents and the like can be added as appropriate.

As a mixing method for obtaining the resin composition of the present invention, after mixing by a Henschel mixer or the like which is generally used in each synthetic resin field, an extrusion mixer, a kneader, a Banbury mixer or the like is further used. It can be melt-mixed by a mixer.

Means for molding the resin composition of the present invention generally include an injection molding method, an extrusion molding method and a compression molding method.

The resin composition of the present invention can be used as an injection-molded product, a blow-molded product, an extrusion-molded product such as a sheet, a film, a pipe, etc. for plating, but can also be used for non-plating. .

The resin composition of the present invention can also be used as a polymer alloy with other resins. As other resins in this case, those shown in Table 1 are typical.
The mixing ratio of the resin composition of the present invention and these resins is usually 90.
/ 10 to 20/80.

[0040]

[Table 1]

[0041]

EXAMPLES Next, the composition of the present invention will be described in more detail based on examples and measurement of physical properties, but the present invention is not limited to these examples. In the examples, unless otherwise indicated,% means% by weight and part means part by weight.

[0042] Production Example I-1 <rubber graft copolymer (A-1) of Production> Component Parts by weight of 1,3-butadiene 150.00 potassium persulfate solution (1%) 15.00 Oleic acid Potassium 2.00 distilled water 190.00 Ethylene glycol Dimethacrylate 0.13 The above compound was reacted for 12 hours at a reaction temperature of 65 ° C, conversion rate 94%, solid content about 40%, weight average particle size.
0.1 μm synthetic rubber latex is obtained.

Further, a polymer flocculant having a carboxyl group is produced by the following components. Ingredients in parts by weight ethyl acrylate 92.0 methacrylic acid 8.0 potassium persulfate solution (1%) reacted 0.5 5 hours sodium dodecyl sulfate 0.5 n-dodecyl mercaptan 1.0 distilled water 200.0 The above set components at the reaction temperature of 75 ° C., the conversion A polymer flocculant having a carboxyl group with a rate of 95% and a pH of 6.2 is obtained.

Next, 100 parts by weight of synthetic rubber latex (solid content) was enlarged using 3.5 parts by weight of a polymer flocculant having a carboxyl group (solid content), pH was 8.7, and weight average particle diameter was about 0.18. A μm bloated rubber latex was produced.

Finally, the enlarged rubber latex was subjected to a graft polymerization reaction by the following formulation to produce a rubber graft copolymer (A-1). Component Weight part Enlarged rubber latex (solid content) 100.0 Styrene 25.0 Acrylonitrile 8.3 Potassium oleate 1.2 Tertiary dodecyl mercaptan 2.0 Isopropylbenzene hydroperoxide 3.0 Ferrous sulfate aqueous solution (0.2%) 3.0 Formaldehyde sodium hyposulfate solution (10% ) 0.9 Ethylenediaminetetraacetic acid solution (0.25%) 3.0 Distilled water 200.0 By coagulating the rubber-like graft latex produced by the above formulation with calcium chloride (CaCl ₂ ),
A rubber-like graft copolymer (A-1) (having a rubber content of 75% by weight) in which the graft ratio required for the present invention is 24% and the molecular weight of the grafted styrene-acrylonitrile copolymer is 78,000 is obtained.

Production Example I-2 <Production of Rubber-like Graft Copolymer (A-2)> The synthetic rubber latex (rubber weight average particle diameter: 0.1 μm) produced in Production Example I-1 is as follows. The composition is directly graft-polymerized to give a rubber content of 71.4% by weight,
A rubber graft copolymer (A-2) in which the rubber weight average particle diameter is 0.1 μm, the graft ratio is 26%, and the molecular weight of the styrene-acrylonitrile copolymer grafted on the rubber is 65,000.
Get. Component Parts by weight synthetic rubber latex (0.1 [mu] m) (solids) 100.0 styrene 30.0 acrylonitrile 10.0 potassium oleate 1.5 tert-dodecyl mercaptan 2.0 di - isopropylbenzene hydroperoxide 3.0 an aqueous ferrous sulfate solution (0.2%) 3.0 Formaldehyde reduction follows sulfate Sodium solution (10%) 0.9 Sodium ethylenediaminetetraacetate solution (0.25%) 3.0 Distilled water 200.0.

Production Example II-1 <Acrylic Copolymer (B-
Production of 1)> 15% by weight of styrene, 70% by weight of methacrylic acid, and 15% by weight of acrylonitrile were mixed as a raw material at a rate of 12 kg / hr, and further 3.0 g / hr of ethylene distearylamide.
, Benzoyl peroxide, tertiary dodecyl mercaptan, and a circulating liquid described later are combined as a feed liquid, and the internal temperature with a stirrer is maintained at 108 ° C and the volume is fed to a continuous kettle reactor with a volume of 45 liters. In addition, the proportion of toluene in the reaction solution is maintained at 15% and the polymerization rate is maintained at 55%.

By removing the volatile matter from the reaction solution by using a devolatilizer, the acrylic copolymer pellets required by the present invention can be obtained. On the other hand, the removed volatile matter becomes a circulating liquid by the condensing action of the condenser, and can be continuously mixed and reused with the raw material. By this method, the reaction rate was controlled while controlling the amount of benzoyl peroxide, and the amount of tertiary dodecyl mercaptan was adjusted to about 12%.
Styrene-acrylonitrile-methyl methacrylate polymer with a melt index of 1.2 at a rate of kg / hr (B
-1) is manufactured.

Production Example II-2 <Acrylic Copolymer (B-
Production of 2)> The composition of the monomers is 78% by weight of styrene and 22 of acrylonitrile.
A styrene-acrylonitrile copolymer (B-2) having a melt index of 1.1 is obtained by the same production method as in Production Example II-1 except that the content is changed to% by weight.

Production Example III <Production of Graft Copolymer (C)> The rubber-like graft copolymer (A-1) obtained in Production Example I-1.
6 parts by weight and 2 parts by weight of styrene-acrylonitrile-methyl methacrylate (B-1) obtained in Production Example II-1
72.0 parts by weight of styrene, 28 parts by weight of acrylonitrile,
7 parts by weight of ethylbenzene and tertiary dodecyl mercaptan
0.09 parts by weight and benzoyl peroxide (initiator) 0.05
The raw material solution consisting of 10 parts by weight is continuously charged at a rate of 22 liters / hr into a propeller type stirring device having a volume of 44 liters and a cooling circulation pipe, and a stirring speed of 100 rp.
m, the reaction temperature is 120 ° C., the pressure in the reactor is 4 kgs, the reaction time is 2 hours, and the mixture is taken out from the first reactor and continuously charged into the second reactor. This second reactor is the same model as the first reactor, and when the monomer conversion rate of the mixture reaches 60%, the mixture is taken out,
The mixture was put in a devolatilization device to remove unreacted monomers and volatile substances, and extruded pellets were obtained to obtain a graft copolymer (C-1). According to the above-mentioned production method, various components were used in the amounts shown in Table 2, and the graft copolymers (C-2) and (C-
3), (C-4), (C-5), (C-6), (C-
7) is manufactured.

[0051]

[Table 2]

[0052] Production Example IV <graft copolymer (D) of Production> Component Parts by weight of 1,3-butadiene 150.00 potassium persulfate solution (1%) 15.00 potassium oleate 2.00 distilled water 190.00 ethylene glycol dimethacrylate 0.13 above The mixture was used and the reaction was carried out at a reaction temperature of 65 ° C for 12 hours to obtain a conversion of 94%, a solid content of about 40%, and a weight average particle size.
0.1 μm synthetic rubber latex is obtained.

Further, a polymer flocculant having a carboxyl group is prepared by the following components. Component parts by weight Ethyl acrylate 90.00 Methacrylic acid 10.00 Potassium persulfate solution (1%) 0.5 Sodium dodecyl sulfate solution (10%) 0.5 n-Dodecyl mercaptan 1.0 Distilled water 200.00 Using the above composition , the reaction temperature is 75 The reaction is carried out at ℃ for 5 hours to obtain a polymer flocculant having a carboxyl group with a conversion of about 95% and a pH of 6.0.

Next, 3 parts by weight of the polymer flocculant having a carboxyl group (solid content) obtained above was used to enlarge 100 parts by weight of synthetic rubber latex (solid content), and the pH was
8.5, a bloated rubber latex having a weight average particle size of about 0.31 μm was produced.

Finally, the enlarged rubber latex was subjected to a graft polymerization reaction based on the following composition to prepare a graft copolymer (D). Component Weight part Enlarged rubber latex (solid content) 100.0 Styrene 38.8 Acrylonitrile 15.0 Potassium oleate 1.6 Tertiary dodecyl mercaptan 2.0 Isopropylbenzene hydroperoxide 3.0 Ferrous sulfate aqueous solution (0.2%) 3.0 Formaldehyde sodium bisulfate solution (10% ) 0.9 Sodium ethylenediaminetetraacetate solution (0.25%) 3.0 Distilled water 200.0 After coagulating and dehydrating the rubber-like graft latex produced by the above formulation with calcium chloride (CaCl ₂ ),
Further, the water content was reduced to 2% or less by drying to obtain a graft copolymer (D) having a graft ratio of 38%, which is the target of the present invention, and a molecular weight of the grafted styrene-acrylonitrile copolymer was 82,000 (rubber). 65% by weight).

Production Example V-1 <Production of styrene-acrylonitrile copolymer (E-1)> 76% by weight of styrene and 24% by weight of acrylonitrile were mixed as raw materials at a rate of 12 kg / hr, and further ethylene distearylamide was added. 3.0 g / hr, benzoyl peroxide,
A third dodecyl mercaptan and a circulating liquid obtained by removing volatile components by the reaction described later and condensing to form a feed liquid,
The internal temperature was maintained at 108 ° C, the volume was 45 liters, and it was fed to a continuous kettle reactor equipped with a stirrer, and the ratio of toluene in the reaction solution was 15% and the polymerization rate was 55%. To maintain.

A styrene-acrylonitrile copolymer pellet is obtained by removing a volatile component from the reaction solution obtained above through a devolatilization device. On the other hand, the removed volatile matter becomes a circulating liquid due to the condensing action of the condenser, and can be continuously mixed with the raw material and reused. By controlling the reaction rate while controlling the amount of benzoyl peroxide and the amount of tertiary dodecyl mercaptan by this method, the melt index of 3.
0 styrene-acrylonitrile polymer (E-1) was produced.

Production Example V-2 <Production of styrene-acrylonitrile-N-phenylmaleimide copolymer (E-2)> 68% by weight of styrene, 22% by weight of acrylonitrile, and N
-Mixing with phenylmaleimide as a raw material at a speed of 12 kg / hr, and further adding ethylene distearylamide 3.0 g / hr,
Benzoyl peroxide, tertiary dodecyl mercaptan, and a circulating liquid obtained by removing volatile components by the reaction described later and condensing to form a feed liquid, the internal temperature was maintained at 108 ° C, and the volume was equipped with a stirrer of 45 liters. It is supplied to a continuous kettle-type reactor and the proportion of toluene in the reaction solution is 15
%, The polymerization rate is maintained at 55%.

The reaction solution obtained above was subjected to a devolatilization apparatus to remove volatile components, and thus styrene-acrylonitrile-
A pellet of N-phenylmaleimide copolymer is obtained. On the other hand, the removed volatile matter becomes a circulating liquid due to the condensing action of the condenser, and can be continuously mixed and reused with the raw material. By this method, the reaction rate was controlled while controlling the amount of benzoyl peroxide, and the amount of tertiary dodecyl mercaptan was adjusted, and a styrene-acrylonitrile-N-phenylmaleimide copolymer (melt index 1.5 was obtained at a rate of about 12 kg / hr. E-2) was produced.

[Characteristic Evaluation] Measuring methods for specific evaluation of the resin compositions obtained in Examples and Comparative Examples described later are as follows. The contents of physical properties measurement in the following Examples and Comparative Examples are divided into two sets, one of which is a physical property including uneven gloss and Izod impact strength as an unplated test piece, and the other is a plated test piece. The physical properties including the appearance of the product, the heat resistance cycle and the adhesion strength were measured. The measurement standard is as follows.

* Glossiness: Gardner 60 ° In
cidence angle) Measured according to ASTM D-523. The unit is%, and the test piece is 300 mm long, 25 mm wide, and 3 mm thick.
Injection molded product whose gate is at a distance of 15 mm from the edge. (a) Uneven gloss at different points: 5 cm from the gate of the test piece
Measure two points of 25 cm from the vertical direction. The smaller the difference between the measured values, the smaller the uneven gloss. (b) Gloss unevenness from the same position in different directions: The glossiness at a position 25 cm from the gate is measured in the direction parallel to the test piece, and the smaller the difference between the measured values, the smaller the gloss unevenness. * Izod impact strength (IZOD): Measured according to ASTM D-256. (Unit: kg / cm / cm) * Appearance of plated molded product: Resin raw material is 101.6 by injection machine
Make a test piece of mm × 76.5 mm × 3.2 mm and plate it. Then, looking at the appearance of the plated test piece, when there is a pinhole or fisheye, it is indicated by "X", and when there is no such hole, it is indicated by "○". * Heat-resistant cycle (passed / tested): 10 pieces of plated test pieces are left at room temperature for 15 minutes, then at -40 ° C for 1 hour, again at room temperature for 15 minutes, and then at 80 ° C for 1 hour. The heating operation is 1 sille, and 1, 3 and 5 respectively.
After repeating the cycle, inspect each plated specimen for cracks or protrusions. If so, it was determined that the heat cycle test did not pass. vice versa,
If not, it is considered to pass the heat resistance cycle test. * Plating layer adhesion strength: Measured according to ASTM D-533 (unit: kg / cm). The plating procedure of the above-mentioned plating test piece is as follows. 1. Degreasing: 5 minutes in a mixed solution of sodium hydroxide, sodium phosphate and sodium carbonate at 50 ° C. 2. Etching: 7 in a mixture of chromic acid and sulfuric acid at 68 ℃
Minutes. 3. Neutralization: 2 minutes in hydrochloric acid solution at 25 ° C. 4. Sensitizing & activating: 4 minutes in a mixture of palladium chloride, tin chloride and hydrochloric acid at 30 ° C. 5. Accelerator: 1 minute in 40 ° C. sulfuric acid solution. 6. Chemical nickel plating: 12 minutes in a mixed solution of nickel sulfate, oxalic acid, sodium dihydrogen phosphate and boric acid at 35 ° C. 7. Copper plating: Immersed in a copper sulfate solution at 25 ° C. for 30 minutes to give a film thickness of 10 μm. 8. Nickel plating: Immersed in a nickel sulfate solution at 55 ° C. for 30 minutes to give a film thickness of 10 μm. 9. Chromium plating: Immersed in a chromium sulfate solution at 50 ° C. for 2 minutes to give a film thickness of 0.15 μm.

Example 1 50% by weight of graft copolymer (C-1) (produced in Production Example III-1) and graft copolymer (D) (Production Example)
(Produced in IV)) and styrene-acrylonitrile copolymer (E-1) (produced in Production Example V-1) were mixed, and 2.0 parts by weight of lubricant and 0.05 part by weight of silicone oil were further mixed. The mixture is added and mixed and extruded into pellets at 220 ° C. by a Werner & Pfleiderer ZSK 35 extruder to obtain a styrene resin composition having a rubber content of 17% by weight. Then, it is injection-molded at 220 ° C (the injection machine used is the SM-90 manufactured by Seio Co., Ltd.) and its physical properties are measured. The conditions for the above injection are as follows.・ Injection temperature: 220 ℃ ・ Injection pressure: 1050kg / cm ² (75%) ・ Injection speed: 72cm ³ / sec (80%) ・ Test piece size: 101.6mm × 76.5mm × 3.2mm Depending on the plating procedure Appearance evaluation, heat resistance cycle and adhesion strength are measured for plated test pieces,
Furthermore, Izod and glossiness were measured. Table 3 shows the obtained results.

Example 2 After uniformly mixing the raw materials having the compositions shown in Table 3, a test piece was molded by the same treatment method as in Example 1 and the physical properties were measured in the same manner as in Example 1. Table 3 shows the measured physical properties and plating characteristics.

Example 3 After the raw materials having the compositions shown in Table 3 were uniformly mixed, a test piece was molded by the same treatment method as in Example 1 and the physical properties were measured in the same manner as in Example 1. Table 3 shows the measured physical properties and plating characteristics.

Example 4 After raw materials having the compositions shown in Table 3 were uniformly mixed, a test piece was molded by the same treatment method as in Example 1 and the physical properties were measured in the same manner as in Example 1. Table 3 shows the measured physical properties and plating characteristics.

Example 5 After uniformly mixing the raw materials having the compositions shown in Table 3, a test piece was molded by the same treatment method as in Example 1 and the physical properties were measured in the same manner as in Example 1. Table 3 shows the measured physical properties and plating characteristics.

Example 6 After uniformly mixing the raw materials having the compositions shown in Table 3, a test piece was molded by the same treatment method as in Example 1 and the physical properties were measured in the same manner as in Example 1. Table 3 shows the measured physical properties and plating characteristics.

Comparative Example 1 A test piece was molded under the same operating conditions as in Example 1 except that the resin composition did not contain the graft copolymer (C), and various physical properties and plating characteristics were measured. Table 3 shows the obtained results.

Comparative Example 2 In Example 1, the graft copolymer (C) was changed to (C-5) in Table 2 (that is, the graft copolymer (C) contained the acrylic copolymer (B). No.), the amounts of other compounding ingredients were changed as shown in Table 3, and test pieces were molded in the same manner as in Example 1, and various physical properties and plating characteristics were measured. Table 3 shows the obtained results.

Comparative Example 3 In Example 1, the graft copolymer (C) was changed to (C-6) in Table 2 (that is, the graft copolymer (C) was replaced by the rubber-like graft copolymer (A). (Not included) and other compounding ingredients were changed as shown in Table 3, a test piece was molded in the same manner as in Example 1, and each physical property and plating characteristic were measured. Table 3 shows the obtained results.

Comparative Example 4 A test piece was prepared in the same manner as in Example 1, except that the content of the graft copolymer (C) in Example 1 was 2% by weight and the amounts of other components were changed as shown in Table 3. Was molded, and its physical properties and plating characteristics were measured. Table 3 shows the obtained results.

Comparative Example 5 In Example 1, the graft copolymer (C) was changed to (A-7) in Table 2 (that is, the amount of the rubber-like graft copolymer (A) used in the graft copolymer). Is 16% by weight),
The amount of other compounding ingredients was changed as shown in Table 3, a test piece was molded in the same manner as in Example 1, and each physical property and plating property were measured.
Table 3 shows the obtained results.

Comparative Example 6 Under the same conditions and composition as in Comparative Example 1, the injection pressure of the resin composition was 420 kg / cm ² (30%) and the injection speed was 31.5 cm ³ / s.
Change to ec (35%). When the injection speed and the injection pressure are reduced as in this Comparative Example 6, the plating characteristics of the composition of Comparative Example 1 can be slightly improved, but the production efficiency decreases due to such changes in the injection conditions, so profitability is obtained. Disappear.

[0074]

[Table 3]

Claims (3)

[Claims] (1) 0.1 to 10 parts by weight of a rubber-like graft copolymer (A) having a weight average particle diameter of 0.05 to 0.8 μm (amount based on 100 parts by weight of a monomer mixture described below) and an acrylic copolymer. (B) In the presence of 0.1 to 10 parts by weight (amount based on 100 parts by weight of the below-mentioned monomer mixture), the styrenic monomer 80
~ 45 wt%, acrylonitrile-based monomer 15-50 wt%, and 100 wt parts of a monomer mixture consisting of 0-40 wt% copolymerizable with these monomers are bulk or solution copolymerized. Graft copolymer (C) 5 to 90% by weight, (2) styrene-based monomer 45 to 80% by weight, acrylonitrile in the presence of 50 to 85 parts by weight of butadiene rubber having a weight average particle diameter of 0.05 to 0.8 μm. Graft copolymer (D) obtained by emulsion-grafting copolymerization of 50 to 15 parts by weight of a monomer mixture consisting of 15 to 50% by weight of a base monomer and 0 to 40% by weight of a monomer copolymerizable therewith. 95 to 10% by weight and (3) 80 to 50 parts by weight of styrene monomer, 20 to 50 of acrylonitrile monomer
A styrene resin composition containing 0 to 80% by weight of a copolymer (E) obtained by copolymerizing 0 to 40 parts by weight of a monomer and 0 to 40 parts by weight of a monomer copolymerizable therewith. 2. The styrene resin composition according to claim 1, wherein the rubber-like graft copolymer (A) is produced by an emulsion polymerization method. 3. The graft ratio of the rubber-like graft copolymer (A) is 10 to 40%, and the molecular weight of the copolymer of the hard portion grafted to the rubber is in the range of 40,000 to 120,000. Item 3. The styrene resin composition according to Item 1 or 2.