JPH1180531A - Thermoplastic resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve impact resistance and weld strength in a PC/ABS alloy. SOLUTION: This composition comprises 20-80 wt.% of a polycarbonate resin (A) and 80-20 wt.% a rubber-reinforced styrene-based resin (B) obtained by polymerizing 90-10 wt.% of a monomer (b-2) composed of 50-90 wt.% of an aromatic vinyl-based monomer and 50-10 wt.% of a vinyl cyanide-based monomer in 10-90 wt.% of an enlarged diene-based rubber (b-1) which is enlarged by adding 0.1-15 pts.wt. of a watersoluble acidic substance to 100 pts.wt. of a small particle dienebased rubber latex (b-i) having 0.05-0.15 μm weight-average particle diameter and has 0.20-2.0 μm weight-average particle diameter. The composition has 8-20 wt.% of the ratio of the enlarged diene-based rubber (b-1) in the composition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an enlarged diene rubber obtained by enlarging a diene rubber latex having a small particle diameter, to an aromatic vinyl represented by styrene and a vinyl cyanide represented by acrylonitrile. The present invention relates to a thermoplastic resin composition comprising a rubber-reinforced styrene-based resin and a polycarbonate resin obtained by graft polymerization of a thermoplastic resin composition having excellent impact resistance and weld strength.

[0002]

2. Description of the Related Art Conventionally, polycarbonate resins have been widely used as engineering resins having excellent impact resistance and heat resistance, but have high molding temperatures, poor fluidity, and have a large thickness dependence of impact strength. There is a disadvantage of saying. For this reason, alloying with a rubber-reinforced styrene resin such as an ABS resin has been proposed, and has already been used for vehicles, OA equipment, and electrical components. Many attempts have been made to improve the impact resistance and reduce the thickness dependency of such an alloy of a polycarbonate resin and a rubber-reinforced styrene resin represented by an ABS resin.
8-15225, JP-B-39-71, JP-B-42-
No. 11,496, and a method of improving the properties using an ABS resin by a specific production method has also been proposed (Japanese Patent Publication No. 51-11142). However, in any of the proposals, the moldability and impact strength are improved, but the weld strength generated in the most common injection molding as a molding method is not sufficient, and it is difficult to say that it is a practically excellent material. is there.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a thermoplastic resin composition comprising a polycarbonate resin and a rubber-reinforced styrene resin, which has excellent impact resistance and weld strength.

[0004]

Means for Solving the Problems The present inventors have conducted intensive studies on the solution of the above-mentioned problems, and as a result, have found that diene rubber obtained by enlarging a diene rubber latex having a small particle diameter using a water-soluble acidic substance is used. It has been found that a resin composition having excellent impact resistance and weld strength can be obtained by using the rubber-reinforced styrene resin, and the present invention has been achieved.

That is, the present invention provides a polycarbonate resin (A) of 20 to 80% by weight and a weight average particle size of 0.05
0.15 μm small particle diene rubber latex (b-
i) An enlarged diene rubber having a weight-average particle diameter of 0.20 to 2.0 μm obtained by adding 0.1 to 15 parts by weight of a water-soluble acidic substance to 100 parts by weight (solid content), and b
-1) 10 to 90% by weight of aromatic vinyl monomer 50 to
90% by weight, vinyl cyanide monomer 50 to 10% by weight
80 to 20% by weight of a rubber-reinforced styrene-based resin (B) obtained by polymerizing 90 to 10% by weight of a monomer (b-2) consisting of
And a ratio of the enlarged diene rubber (b-1) in the composition is 8 to 20% by weight.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The polycarbonate resin (A) used in the present invention is obtained by reacting various dihydroxydiaryl compounds with phosgene, or by reacting a dihydroxydiaryl compound with a carbonate such as diphenyl carbonate. A polymer obtained by a transesterification method.
2,2-bis (4-hydroxyphenyl) propane; "
And polycarbonate resins produced from bisphenol A ".

As the above dihydroxydiaryl compounds, bis (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) ethane, and 2,2-bis (4-hydroxyphenyl) are used in addition to bisphenol A.
Butane, 2,2-bis (4-hydroxyphenyl) octane, bis (4-hydroxyphenyl) phenylmethane, 2,2-bis (4-hydroxyphenyl-3-methylphenyl) propane, 1,1-bis (4 -Hydroxy-3-tert-butylphenyl) propane, 2,2-bis (4-hydroxy-3-bromophenyl) propane,
2,2-bis (4-hydroxy-3,5-dibromophenyl) propane, 2,2-bis (4-hydroxy-3,
Bis (hydroxyaryl) alkanes such as 5-dichlorophenyl) propane, bis (hydroxyaryl) such as 1,1-bis (4-hydroxyphenyl) cyclopentane and 1,1-bis (4-hydroxyphenyl) cyclohexane Cycloalkanes, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxy-
Dihydroxydiaryl ethers such as 3,3'-dimethyldiphenylether, 4,4'-dihydroxydiphenylsulfide, 4,4'-dihydroxy-3,
Dihydroxydiaryl sulfides such as 3'-dimethyldiphenyl sulfide, 4,4'-dihydroxydiphenyl sulphoxide, 4,4'-dihydroxy-
Dihydroxydiarylsulfoxides such as 3,3'-dimethyldiphenylsulfoxide; dihydroxydiarylsulfones such as 4,4'-dihydroxydiphenylsulfone; and 4,4'-dihydroxy-3,3'-dimethyldiphenylsulfone. Can be

These may be used alone or as a mixture of two or more kinds. In addition, piperazine, dipiperidyl hydroquinone, resorcin, 4,4'-dihydroxydiphenyl and the like may be used in combination.

Further, the above-mentioned dihydroxydiaryl compound and a phenol compound having three or more valences as shown below may be mixed and used. Phloroglucin, 4,6-dimethyl-2,4,6-tri-
(4-hydroxyphenyl) -heptene-2,4,6-
Dimethyl-2,4,6-tri- (4-hydroxyphenyl) -heptane, 1,3,5-tri- (4-hydroxyphenyl) -benzol, 1,1,1-tri- (4-hydroxyphenyl) -Ethane and 2,2-bis-
[4,4- (4,4′-dihydroxydiphenyl) -cyclohexyl] -propane and the like. In producing these polycarbonate resins, a molecular weight regulator, a catalyst and the like can be used as needed.

The viscosity-average molecular weight of the polycarbonate resin used is not particularly limited, but is preferably 10,000 to 10,000.
Preferably it is 50,000, especially 15,000 to 30,000.

The rubber-reinforced styrene resin (B) is defined as 0.1 to 100 parts by weight (solid content) of a small particle diene rubber latex (bi) having a weight average particle diameter of 0.05 to 0.15 μm. 10 to 90% by weight of an enlarged diene rubber (b-1) having a weight average particle diameter of 0.20 to 2.0 μm, which is obtained by adding to 15 to 15 parts by weight of a water-soluble acidic substance; (B-2) 90-1 consisting of 50-90% by weight of a monomer and 50-10% by weight of a vinyl cyanide monomer
0% by weight, specifically, a graft polymer (b) obtained by polymerizing the monomer (b-2) in the presence of the enlarged diene rubber (b-1). -G) or a mixture of the graft polymer and a copolymer (br) obtained by polymerizing the monomer (b-2).

The diene rubber used above includes polybutadiene, butadiene-styrene copolymer,
Butadiene-acrylonitrile copolymer can be mentioned. The enlarged diene rubber (b-1) is used in an amount of 0.1 to 100 parts by weight (solid content) of the diene rubber latex (bi) having an average particle diameter of 0.05 to 0.15 μm.
It is a diene rubber having an average particle diameter of 0.2 to 2 μm obtained by adding 〜15 parts by weight of a water-soluble acidic substance. When the average particle diameter of the small particle diameter diene rubber latex is 0.05 μm or less, agglomerates at the time of production increase and productivity is extremely poor. On the other hand, if it is 0.15 μm or more, a sufficiently enlarged rubber latex cannot be obtained even when a water-soluble acidic substance is added.

The water-soluble acidic substances to be added include mineral acids,
Acid salts and organic acids, specifically, sulfuric acid, hydrochloric acid, phosphoric acid, sodium hydrogen sulfate, sodium dihydrogen phosphate, oxalic acid, citric acid, acetic acid, formic acid and the like. Particularly, phosphoric acid, sulfuric acid, and oxalic acid are preferable from the viewpoint of coagulation and enlargement. The amount of the water-soluble acidic substance to be added is small particle size diene rubber latex 10
0.1 to 15 parts by weight with respect to 0 parts by weight (solids). If the amount is less than 0.1 part by weight, the aggregation of the rubber particles is not sufficient, and the desired enlarged diene rubber latex cannot be obtained. If the amount is less than 15 parts by weight, agglomeration becomes remarkable, leading to solidification. Further, the pH of the water-soluble acidic substance is preferably 4.5 or less. If the pH is 4.5 or more, the aggregation of the rubber particles is not sufficient, and the average particle diameter is 0.0
A large number of rubber particles having a small particle diameter of 5 to 0.15 μm tend to be present, which is not preferred.

The aromatic vinyl monomer constituting the rubber-reinforced styrene resin (B) includes styrene, α-methylstyrene, o-methylstyrene, m-methylstyrene,
p-methylstyrene, t-butylstyrene, α-methylvinyltoluene, dimethylstyrene, chlorostyrene,
Examples thereof include dichlorostyrene, bromostyrene, dibromostyrene, and vinylnaphthalene, and styrene and α-methylstyrene are particularly preferable.

Examples of the vinyl cyanide monomer include acrylonitrile, methacrylonitrile, fumaronitrile and the like, and acrylonitrile is particularly preferred.

In the present invention, other copolymerizable monomers such as acrylic acid, methacrylic acid, maleic acid, and maleic anhydride may be used together with the above-mentioned monomers. Anhydride, maleimide,
Maleimide compounds such as methylmaleimide, ethylmaleimide, N-phenylmaleimide, methyl acrylate,
It is also possible to use unsaturated carboxylic acid alkyl ester monomers such as ethyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, and hydroxyethyl methacrylate.

In the monomer (b-2), the composition ratio of the aromatic vinyl monomer and the vinyl cyanide monomer is 50 to 90% by weight of the aromatic vinyl monomer and the vinyl cyanide monomer. 50 to 10% by weight, and outside such a range,
Heat resistance, workability, and weld strength are also poor, which is not preferable. Other copolymerizable monomers can be used in the range of 0 to 20% by weight.

The composition ratio of the enlarged diene rubber (b-1) and the monomer (b-2) is determined by the following formula.
1) 10 to 90% by weight and monomer (b-2) 90 to 1
0% by weight. If (b-1) is less than 10% by weight (the monomer (b-2) exceeds 90% by weight), the alloy with polycarbonate has significantly poor impact resistance and weld strength. When (b-1) exceeds 90% by weight [monomer (b-2) is less than 10% by weight], heat resistance and fluidity are poor.

In the present invention, the composition ratio of the polycarbonate resin (A) and the rubber-reinforced styrene resin (B) is 20 to 80% by weight of the polycarbonate resin (A) and 80 to 20% by weight of the rubber-reinforced styrene resin (B). . When the content of the polycarbonate resin (A) is less than 20% by weight (the content of the rubber-reinforced styrene-based resin (B) exceeds 80% by weight), the impact resistance and heat resistance are poor, and the weld strength is also poor. When the content of the polycarbonate resin (A) exceeds 80% by weight and the content of the rubber-reinforced styrene-based resin (B) is less than 20% by weight, the fluidity is poor.

In the present invention, the proportion of the enlarged diene rubber (b-1) in the composition comprising the polycarbonate resin (A) and the rubber-reinforced styrene resin (B) is important. Is 8 to 20% by weight. When the proportion of the enlarged diene rubber (b-1) is less than 8% by weight, not only the impact resistance but also the weld strength is remarkably poor, and when it exceeds 20% by weight, the impact resistance and the weld strength are similarly poor. Therefore, it is not preferable. From the viewpoints of impact resistance and weld strength, the proportion of the enlarged diene rubber (b-1) is particularly preferably in the range of 10 to 18% by weight.

The mixing of the thermoplastic resin composition of the present invention can be carried out by a known method such as an ordinary extruder or kneader. In addition, a coloring agent, a dispersant antioxidant, an ultraviolet absorber, a flame retardant, a filler, and the like can be added to the thermoplastic resin composition of the present invention as needed.

[Examples] The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. In the examples, parts and percentages are based on weight.

{Polycarbonate Resin (A)} An aromatic polycarbonate having a viscosity average molecular weight of 23,000 and comprising 2,2-bis (4-hydroxyphenyl) propane and phosgene.

{Rubber Reinforced Styrene Resin (B)} [Production of Small Particle Diene Rubber] 100 parts of 1,3-butadiene was placed in a pressure vessel, and 0.2 parts of potassium persulfate was used as an initiator.
5 parts, t-dodecylmercaptan 0.3 part as molecular weight regulator, potassium persulfate 0.25 part, sodium rosinate 2.5 parts, sodium hydroxide 0.1 part, pure water 170
After the temperature was raised to 80 ° C., polymerization was started. By making each polymerization time variable, 0.03μ
(Bi-1), 0.08 [mu] (bi-2), 0.10
μ (bi-3), 0.12μ (bi-4), 0.1
8 μ (bi-5) small particle diene rubber and 0.1 μm (bi-5).
3 μ (bX) of the unexpanded diene rubber was polymerized.

[Production of Enlarged Diene Rubber] Into a pressure vessel, the above small particle diene rubber [0.03 μ (bi)
-1), 0.08μ (bi-2), 0.10μ (b-
i-3), 0.12 μ (bi-4), 0.18 μ (b
-I-5)] A water-soluble acidic substance shown in Table 1 was added to 100 parts (solid content), and the enlarged diene rubbers (b-1-1 to b-1-7) shown in Table 1 were respectively added. I got

[Production of Graft Polymer] In the pressure vessel, the above-mentioned enlarged diene rubber (b-1-1 to b-1-7) and unexpanded diene rubber (bX), sodium dodecylbenzenesulfonate 1.5 parts, potassium persulfate, 0.3
After the temperature was raised to 70 ° C., a monomer mixture composed of styrene and acrylonitrile shown in Table 2 was continuously added over 5 hours, and each of the graft polymer latexes (bg-1 to 8) was used. I got A phenolic antioxidant (Sumitomo Chemical Co., Ltd .: Sumilizer B) is used as an antioxidant per 100 parts by weight (solid content) of each obtained latex.
BM) 1 part and trisnonylphenyl phosphite 2
After the addition of part, salting out, dehydration and drying were performed using magnesium sulfate to obtain graft polymers (bg-1 to 8).

[Production of copolymer] A copolymer (br) composed of 30% of acrylonitrile and 70% of styrene was polymerized by a known bulk polymerization method.

Examples 1 to 4 and Comparative Examples 1 to 7 The polycarbonate resin (A) and the above graft copolymer (b)
-G-1 to 7) and the copolymer (br) were mixed at the compounding ratio shown in Table 3, and the mixture was added to a mixture using a 40 mm twin-screw extruder.
After melt mixing at ℃ and forming pellets, various test pieces were prepared with an injection molding machine and physical properties were evaluated. Table 3 shows the results.

O Impact resistance: according to ASTM D-256. 1/4 inch, 23 ° C. o Weld strength: A molten resin (260 ° C.) is injected from two gates (2.5 × 2.5 mm each) with a gate interval of 100 mm to prepare a test piece 150 × 150 × 3 mm thick. The test piece is placed on a jig (height: 80 mm, inner diameter: 120 mm, outer diameter: 126 mm). A 1 kg steel ball is dropped on the center of the test piece in a low temperature chamber adjusted to -30 ° C., and the maximum energy value (kg · cm) at which the test piece is not broken is determined. o Moldability: based on ASTM D-1238. Condition 250
C, 10 kg. o Heat resistance: Conforms to ASTM D-648. Condition 1.82
MPa, 6.4 mm thick. o Appearance: A flat plate having a thickness of 50 × 50 × 3 mm was formed, and the presence or absence of a flow mark was visually determined.

[0030]

[Table 1]

[0031]

[Table 2]

[0032]

[Table 3]

[0033]

As described above, the resin composition of the present invention is excellent in impact resistance and weld strength, and is also excellent in various physical properties, and is useful as various molding materials.

Claims (2)

[Claims] 1. Polycarbonate resin (A) 20 to 80
0.1 to 15 parts by weight of a water-soluble acidic substance is added to 100 parts by weight (solid content) of a small particle diene rubber latex (bi) having a weight% and a weight average particle diameter of 0.05 to 0.15 μm. Weight average particle size 0.20
2.0 μm enlarged diene rubber (b-1) 10 to 90
A rubber obtained by polymerizing 90 to 10% by weight of a monomer (b-2) consisting of 50 to 90% by weight of an aromatic vinyl monomer and 50 to 10% by weight of a vinyl cyanide monomer. A thermoplastic resin comprising 80 to 20% by weight of the reinforced styrene-based resin (B), and wherein the proportion of the enlarged diene-based rubber (b-1) in the composition is 8 to 20% by weight. Composition. 2. The thermoplastic resin composition according to claim 1, wherein the pH of the water-soluble acidic substance is 4.5 or less.