JPH11140295A - Vibration-damping thermoplastic resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a vibration-damping thermoplastic resin composition having little whitening by bending, excellent vibration-damping property and excellent in shock resistance and weld strength. SOLUTION: This composition comprises 20-80 wt.% polycarbonate resin (A) and 80-20 wt.% MBS-based resin (B) obtained by polymerizing 10-80 wt.% expanded diene-based rubber (b-1) having 0.15-2.0 μm weight-average particle diameter which is expanded by adding 0.1-20 pts.wt. water-soluble acidic substance to 100 pts.wt. (on a solid basis) small particles of diene-based rubber latex having 0.05-0.15 μm weight-average particle diameter with 90-20 wt.% monomer (b-2) consisting of 30-80 wt.% unsaturated carboxylic alkyl ester monomer and 70-20 wt.% aromatic vinyl monomer and/or vinyl cyanide monomer. The proportion of the expanded diene-based rubber (b-1) in the composition is 8-20 wt.%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an enlarged diene rubber obtained by enlarging a diene rubber latex having a small particle diameter, and to an unsaturated carboxylic acid alkyl ester represented by methyl methacrylate and styrene. Damping Thermoplastic Resin Composition Made of MBS-Based Resin Obtained by Polymerizing Vinyl Cyanide Represented by Aromatic Vinyl and / or Acrylonitrile and Polycarbonate Resin with Low Bending Whitening, Excellent Impact Resistance and Weld Strength It is about things.

[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 37-71, JP-B 42
No. 11496, and a method of improving using an ABS resin by a specific production method has also been proposed (Japanese Patent Publication No. 51-11142). However, in recent years, in the direction of weight reduction and miniaturization of vehicles, OA equipment, and electric components, in particular, performance of absorbing vibration has been demanded for vibration of rotating equipment and the like. However, cases where so-called vibration damping properties are required are increasing. ABS
Rubber-reinforced styrene resins and polycarbonate resins represented by resins have a problem in terms of such vibration damping properties,
Alloys that are a mixture of these two have similar problems, and in particular, are likely to resonate with rotating peripheral devices in recent OA devices, and thus improvements are desired. further,
These materials are required to have not only impact resistance but also weld strength and less bending whitening.

[0003]

SUMMARY OF THE INVENTION The present invention provides a vibration-damping thermoplastic resin composition comprising a polycarbonate resin and a specific MBS-based resin, which has low bending whitening, and has excellent impact resistance and weld strength. The purpose is to do so.

[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 latex having a small particle diameter is enlarged using a water-soluble acidic substance. By using an MBS-based resin obtained by polymerizing an unsaturated carboxylic acid alkyl ester as an essential component, a vibration-damping thermoplastic resin composition having less bending whitening, and having excellent impact resistance and weld strength can be obtained. That is, the present invention has been achieved.

[0005] The present invention relates to a polycarbonate resin (A) 2
0 to 80% by weight and a weight average particle size of 0.05 to 0.1.
5 μm small particle diene rubber latex (bi) 10
0.1 to 20 parts by weight of a water-soluble acidic substance is added to 0 parts by weight (solid content) to give an enlarged diene rubber having a weight average particle diameter of 0.15 to 2.0 μm (b- 1)
10 to 80% by weight, 30 to 80% by weight of unsaturated carboxylic acid alkyl ester monomer and 70 to 20% by weight of aromatic vinyl monomer and / or vinyl cyanide monomer
Consisting of 80 to 20% by weight of an MBS resin (A) obtained by polymerizing 90 to 20% by weight of a monomer (b-2) consisting of
And an enlarged diene rubber (b-1) occupying in the composition
Is in the range of 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 MBS resin (B) in the present invention is:
0.1 to 20 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 average particle diameter of 0.05 to 0.15 μm to enlarge. 10 to 80% by weight of an enlarged diene rubber (b-1) having a weight average particle diameter of 0.15 to 2.0 μm and 30 to 80% by weight of an unsaturated carboxylic acid alkyl ester monomer
And 70 to 20% by weight of an aromatic vinyl monomer and / or a vinyl cyanide monomer (b-
2) A graft obtained by polymerizing 90 to 20% by weight of a monomer (b-2) in the presence of the enlarged diene rubber (b-1). Polymer (b
-G) or a mixture of the graft polymer (bg) 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 0.15 to 2.0 μm obtained by adding ２０20 parts by weight of a water-soluble acidic substance. The average particle diameter of the small particle diameter diene rubber latex is 0.05
If it is less than μm, agglomerates at the time of production increase, and the productivity is extremely poor. If it exceeds 0.15 μm, 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 20 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 it exceeds 20 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 unsaturated carboxylic acid alkyl ester monomer constituting the MBS resin (B) in the present invention includes methyl acrylate, ethyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, hydroxyethyl methacrylate and the like. Particularly, methyl methacrylate is preferred.

The aromatic vinyl monomers include styrene, α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, t-butylstyrene, α-methylvinyltoluene, dimethylstyrene, chlorostyrene. Styrene, dichlorostyrene, bromostyrene, dibromostyrene, vinyl naphthalene and the like,
Particularly, styrene and α-methylstyrene are preferred. Examples of the vinyl cyanide monomer include acrylonitrile, methacrylonitrile, fumaronitrile and the like, and acrylonitrile is particularly preferable.

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,
It is also possible to use maleimide compounds such as methylmaleimide, ethylmaleimide and N-phenylmaleimide.

The composition ratio of the monomer (b-2) is 30 to 80% by weight of the unsaturated carboxylic acid alkyl ester monomer and 70 to 80% of the aromatic vinyl monomer and / or the vinyl cyanide monomer. When the content is outside the above range, vibration damping properties are inferior. 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 80% by weight and 90 to 2 of the monomer (b-2)
0% by weight. When (b-1) is less than 10% by weight [the monomer (b-2) exceeds 90% by weight], the impact resistance and weld strength are poor, and (b-1) exceeds 80% by weight [ When the amount of the monomer (a-2) is less than 20% by weight], the fluidity is poor.

The composition ratio of the polycarbonate resin (A) to the MBS resin (B) in the present invention is 20 to 80% by weight of the polycarbonate resin (A) and 80 to 20% by weight of the MBS resin (B). When the content of the polycarbonate resin (A) is less than 20% by weight (the content of the MBS-based resin (B) exceeds 80% by weight), the impact resistance and weld strength are poor.
In addition, since the dispersibility is reduced, the appearance of the molded product is poor. When the content of the polycarbonate resin (A) exceeds 80% by weight (the content of the MBS-based resin (B) is less than 20% by weight), the fluidity is poor and the vibration damping property 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 MBS resin (B) is important, and the proportion is 8%. -20% by weight. When the proportion of the enlarged diene rubber (b-1) is less than 8% by weight, not only impact resistance but also weld strength is remarkably deteriorated, and furthermore, vibration damping properties are deteriorated. On the other hand, if the content exceeds 20% by weight, the weld strength and the bending whitening property and the appearance of the molded product are inferior. From the viewpoints of impact resistance and weld strength, the ratio of the enlarged diene rubber (b-1) is particularly preferably from 10 to 18%.
Preferably it is in the range of 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. Further, a coloring agent, a dispersant, an antioxidant, an ultraviolet absorber, a flame retardant, a filler, or 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 Copolymer]
The enlarged diene-based rubber (b-1-1 to b-1-7) and the unexpanded diene-based rubber (bX), 1.5 parts of sodium dodecylbenzenesulfonate, potassium persulfate, 0.1%
After charging 3 parts and raising the temperature to 70 ° C., a monomer mixture comprising methyl methacrylate, styrene and acrylonitrile shown in Table 2 was continuously added over 5 hours, and each of the graft polymer latex (bg-g) was added. 1-8) were obtained.
After adding 1 part of phenolic antioxidant (Sumitomo Chemical Co., Ltd .: Sumilizer BBM) and 2 parts of trisnonylphenyl phosphite as antioxidants per 100 parts by weight (solid content) of each obtained latex, magnesium sulfate was added. Was used for salting out, dehydration and drying to obtain a graft polymer (bg-1 to 8).

[Production of copolymer] By a known bulk polymerization method, methyl methacrylate 70% and styrene 30%
(Br-1) and a copolymer (br-2) consisting of 65% methyl methacrylate, 20% styrene and 15% acrylonitrile.

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-1 to 2) were mixed at the compounding ratio shown in Table 3 and melt-mixed at 230 ° C. using a 40 mm twin-screw extruder to form pellets. Various test pieces were prepared using an injection molding machine, and the 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 Vibration control : tan δ at a frequency of 10 Hz was measured using DVE Rheospectral manufactured by Rheology. o Folding whitening property : A 0.5 mm sheet was bent at 90 °, and the whitening of the sheet was visually determined. 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 has little bending whitening and is excellent in impact resistance, weld strength, and vibration damping properties, and is particularly useful in applications requiring vibration damping properties. It is.

Continuation of the front page (72) Inventor Bunzo Mori 2- 10-1 Tsukahara, Takatsuki-shi, Osaka Sumika EBS Latex Co., Ltd.

Claims (2)

[Claims] 1. Polycarbonate resin (A) 20 to 80
0.1 to 20 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 diameter 0.15
2.0 μm enlarged diene rubber (b-1) 10 to 80
% By weight and unsaturated carboxylic acid alkyl ester monomer 30
MB obtained by polymerizing 90 to 20% by weight of a monomer (b-2) composed of 70 to 20% by weight and 70 to 20% by weight of an aromatic vinyl monomer and / or a vinyl cyanide monomer.
80 to 20% by weight of the S-based resin (A), and the ratio of the enlarged diene-based rubber (b-1) in the composition is 8%.
A vibration damping thermoplastic resin composition characterized in that the content is from 20 to 20% by weight. 2. The vibration-damping thermoplastic resin composition according to claim 1, wherein the pH of the water-soluble acidic substance is 4.5 or less.