JPS6172054A - Thermoplastic resin composition - Google Patents

Abstract

PURPOSE:To provide a composition composed of an aromatic polycarbonate resin, an ABS resin, and an acrylic acid ester graft copolymer, and having improved moldability, low-temperature impact resistance and the thickness- dependency of the impact resistance, and balanced heat-resistance, etc. CONSTITUTION:The objective composition can be prepared by compounding (A) 40-80(wt)% aromatic polycarbonate resin with (B) 20-60% mixture of (i) 100-10% conjugated diene rubber-aromatic vinyl compound-vinyl cyanide graft copolymer and (ii) 0-90% aromatic vinyl compound-vinyl cyanide copoly mer (preferably having an aromatic vinyl content of 55-85%)s, and (C) 1-15% acrylic acid ester graft copolymer. The graft copolymer in the component B is preferably the one composed of 5-70% conjugated diene rubber and 95-30% graft-polymerization compound (having an aromatic vinyl content of 50-80%).

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention provides a thermoplastic resin composition that exhibits various mechanical properties, particularly excellent impact resistance at low temperatures, and exhibits good appearance and moldability. The purpose is to provide molding materials suitable for automobile parts and the like.

[Conventional technology and its problems]

As is well known, aromatic polycarbonate resins are tough, have excellent impact resistance, electrical properties, and good dimensional stability, and are therefore widely used as useful engineering plastics. However, the range of its application is currently limited due to drawbacks such as high melt viscosity, poor moldability, and thickness dependence of impact resistance. For example, in the automobile industry, there is a strong demand for resins that have impact resistance at low temperatures due to safety needs, and aromatic polycarbonate resins are attracting attention for this reason. Due to its high viscosity, it is difficult to fill molds for large molded products such as automobile parts, resulting in short molds and crepe patterns, making it difficult to obtain good molded products.

Therefore, if the molding temperature is raised to a level that makes filling easy, problems such as thermal decomposition occur, making it difficult to obtain a molded product with good appearance and stable physical properties. On the other hand, there is a method of improving the moldability by lowering the average molecular weight of the polycarbonate resin, but this method has drawbacks such as a decrease in impact resistance and difficulty in releasing the resin from the mold.

In order to improve these drawbacks, proposals have been made to blend various resins into aromatic polycarbonate resins. For example, Japanese Patent Publication No. 38-15225 uses ABS resin, Japanese Patent Publication No. 39-71 uses MBS resin, Japanese Patent Publication No. 42-1
Publication No. 1496 teaches incorporating MABS resin. However, polycarbonate resin has A
Although the thickness dependence of impact resistance and moldability are somewhat improved when BS resin or MABS resin is blended, the impact resistance at low temperatures is low, and the improvement is not necessarily sufficient to meet recent market demands. I can't say that. Furthermore, when MBS resin is blended with polycarbonate resin, the improvement in moldability is insufficient and it is difficult to mold large-sized molded products.

[Means for solving problems]

The present invention improves the moldability of the polycarbonate resin and its impact resistance and impact resistance at low temperatures by further blending a specific acrylic acid ester graft copolymer into the composition of polycarbonate resin and ABS resin. The present inventors have discovered a thermoplastic resin composition that has improved thickness dependence and has a well-balanced variety of properties such as mechanical strength, heat resistance, and appearance, and has completed the present invention.

That is, the present invention comprises A, aromatic polycarbonate resin 40 to 80 wt%, B, conjugated diene rubber-aromatic vinyl-vinyl cyanide graft copolymer 100 to 10 wt%.
t% and aromatic vinyl-vinyl cyanide copolymer O~90
20 to 60 wt%, and C.

Acrylic acid ester graft copolymer 1 to 15 wt%
A thermoplastic resin composition comprising:

The present invention will be explained in detail below.

A, aromatic polycarbonate resin of the present invention is an optionally branched thermoplastic polycarbonate polymer made by reacting aromatic dihydroxy or a small amount of a polyhydroxy compound with a diester of phosgene or carbonic acid. An example of an aromatic dihydroxy compound is
2.2-bis(4-hydroxyphenyl)propane (7-bisphenol A), tetramethylbisphenol A,
Examples include tetrabromobisphenol A, bis(4-hydroxyphenyl>-p-diisopropylbenzene,)1-hydroquinone, resorcinol, and 4,4-dihydroxydiphenyl, with bisphenol A being particularly preferred.

In addition, to obtain a branched aromatic polycarbonate resin, phloroglucin, 4.6-cymethyl-2.4.6-
) li (4-hydroxyphenyl)hebutene-2,4
, 6-dimethyl-2.4.6-)li(4-hydroxyphenyl)hebutane, 2.6-dimethyl-2.4.
6-tri(4-hydroxyphenyl)hebutene-3
,4,6-dimethyl-2.4.6-)li(4-hydroxyphenyl)hebutane,1,3.5-)li(
4-hydroxyphenyl)benzene, 1. Ll-)li
Polyhydroxy compounds exemplified by (4-hydroxyphenyl)ethane, 3,3-bis(4-hydroxyaryl)oxindole (= isatin bisphenol), 5-chloroisatin, 5,7-dichloroisatin, 5-bromiisatin A part of the dihydroxy compound, for example 0.1 to 2 mol %, is replaced with a polyhydroxy compound. Furthermore, the m aromatic hydroxy compounds passed to adjust the molecular weight include m- and p-methylphenol, m- and p-propylphenol, p-bromophenol, pwtert-butylphenol, and p-
-Long chain alkyl substituted phenols and the like are preferred. A typical aromatic polycarbonate resin is bis(4-
hydroxyphenyl)alkane dihydroxy compound,
Particular examples include polycarbonates whose main raw material is bisphenol A, as well as polycarbonate copolymers obtained by using two or more types of aromatic dihydroxy compounds in combination, and branched polycarbonates obtained by using a small amount of trivalent phenol compounds in combination. I can do it. Aromatic polycarbonate resins may be used as a mixture of two or more.

The conjugated diene rubber-aromatic vinyl-vinyl cyanide graft copolymer, which is one of the B components of the present invention, is a rubbery polymer containing a conjugated diene as an essential component, and an aromatic vinyl compound and vinyl cyanide. This is a graft polymer obtained by graft polymerization using the following as an essential component. There is no particular restriction on the composition ratio of the conjugated diene rubber and the graft polymerization compound in the graft polymer, but the conjugated diene rubber and the graft polymerization compound should be 5 to 70 wt% and 95 to 30 wt%, respectively. preferable. Further, the composition ratio of aromatic vinyl to vinyl cyanide in the graft polymerization compound is not particularly limited, but it is preferably 50 to 80 wt% of aromatic vinyl and 50 to 20 wt% of vinyl cyanide.

There is no particular restriction on the composition ratio of aromatic vinyl and vinyl cyanide in the aromatic vinyl-vinyl cyanide copolymer, but it is preferably 55 to 85 wt% of aromatic vinyl and 45 to 15 wt% of vinyl cyanide. , the viscosity is also 0.60 to 1.5 at 30'C in dimethylformamide.
A range of 0 is preferred.

The conjugated diene rubber in the above graft copolymer or copolymer includes polybutadiene, butadiene-styrene copolymer, butadiene-acrylonitrile copolymer,
Examples include butadiene-based rubbery polymers such as butadiene-acrylic acid ester copolymers. Examples of aromatic vinyl include styrene, halogenated styrene, vinyltoluene, α-methylstyrene, vinylnaphthalene, etc., with styrene being particularly good; examples of vinyl cyanide include acrylonitrile, methacrylonitrile, α-methylstyrene, and α-methylstyrene.
- Examples include halogenated acrylonitrile, and acrylonitrile is particularly good. In addition, aromatic vinyl or vinyl cyanide partially substituted with other vinyl compounds, such as (meth)acrylic esters, vinyl acetate, vinyl chloride, etc., particularly (meth)acrylic esters, are also preferable. .

The C, acrylic acid ester-based graft copolymer used in the present invention is mainly composed of an alkyl ester of acrylic acid with an alkyl group having 2 to 12 carbon atoms, and a conjugated diene type double bond represented by butadiene. A conjugated diene-modified acrylic ester-based rubbery copolymer obtained by copolymerizing polyfunctional polymerizable monomers with polyfunctional polymerizable monomers as essential components, and graft polymerization with one or more vinyl compounds as essential components. Refers to the resulting graft copolymer. As a polyfunctional polymerizable monomer with a conjugated diene double bond,
In addition to the above butadiene, 1-methyl-2-vinyl-4
, 6-hebutadien-1-ol, 7-methyl-3-methylene-1,6-octadiene, 1,3.7-octatriene and the like. In addition, when copolymerizing an alkyl ester of acrylic acid with a polyfunctional polymerizable monomer having a conjugated diene type double bond, an aromatic vinyl compound such as styrene or methyl methacrylate may be used as desired. methacrylic acid ester, vinyl cyanide compound represented by acrylonitrile, vinyl ether compound represented by methyl vinyl ether, vinyl halide compound represented by vinyl chloride, and vinyl ester compound represented by vinyl acetate. A crosslinking agent typified by monofunctional polymerizable monomers, ethylene dimethacrylate, and divinylbenzene is appropriately selected and used. Vinyl compounds used in graft polymerization include methacrylic acid esters represented by methyl methacrylate, aromatic vinyl compounds represented by styrene,
Examples include polymerizable monomers selected from the group consisting of vinyl cyanide compounds represented by acrylonitrile and halogenated vinyl compounds represented by vinyl chloride,
These may be used in combination of two or more types. Furthermore, the above-mentioned crosslinking agent may be used in combination during graft polymerization. In producing the acrylic acid ester-based graft copolymer, the polyfunctional polymerizable carmer having the conjugated diene double bond is present in the copolymer with the alkyl ester of acrylic acid.
．． It is used in an amount accounting for 1 to 10% by weight.

A typical example is acrylic ester (e.g. n
- butyl acrylate, 2-ethylhexyl acrylate) and butadiene with a small amount of crosslinking agent (e.g. ethylene dimethacrylate, divinylbenzene) and optionally a methacrylic acid ester (e.g. methyl methacrylate).
and are copolymerized by emulsion polymerization according to a conventional method, and styrene,
Graft copolymer obtained by adding a vinyl compound appropriately selected from methyl methacrylate, acrylonitrile, vinyl chloride, etc. and graft polymerizing according to a conventional method; acrylic ester (e.g., n-butyl acrylate, 2-
ethylhexyl acrylate) and compounds that have a non-conjugated double bond in addition to a conjugated diene type double bond in one molecule (e.g. 1-vinyl-2-vinyl-4,6-hebutadiene-
1-ol) and an ester of methacrylic acid as desired by a conventional method, a graft component monomer is added to the obtained latex, and graft polymerization is carried out according to a conventional method to obtain a graft copolymer, etc. It is.

These graft polymerizations may be carried out in one stage, or may be carried out in multiple stages by changing the components of the graft component monomer in multiple stages. Although a typical production example is shown using the emulsion polymerization method, the desired acrylic ester graft copolymer can also be produced by other known polymerization methods. Such acrylic ester-based graft copolymers are manufactured by Kureha Chemical Industry Co., Ltd. under the trade names rHIA-15J and rHIA-28.
Alternatively, a resin commercially available as rHIA-30J is preferably used.

In the thermoplastic resin composition of the present invention, A, the aromatic polycarbonate resin is 40 to 80 wt%, and B, the conjugated diene rubber-aromatic vinyl-vinyl cyanide graft copolymer is 100-lowt% and the aromatic vinyl-cyanide. Vinyl graft copolymer O~90 wt% Tono mixture 20
~60 wt%, and 1~15 wt% of C, acrylic acid ester graft copolymer.

If the amount of aromatic polycarbonate resin is less than 40 wt%, the heat resistance will not reach the level required for engineering plastics, and the dimensional stability will also be poor.

B. If the amount of the graft copolymer or a mixture thereof is less than 20 wt %, the improvement effect on moldability, impact resistance, etc. will be insufficient, and if it exceeds 60 wt %, the heat resistance will be insufficient. Furthermore, if the amount of the C0 acrylic ester graft copolymer is less than 1 wt%, no improvement in impact resistance will be achieved, and if it exceeds 15 wt%, it will cause poor heat resistance.

The thermoplastic resin composition of the present invention as described above may contain various additives such as stabilizers, pigments, dyes, flame retardants, and lubricants, reinforcing materials such as inorganic or organic fiber substances, glass beads, etc., as desired. Various fillers may be blended, and other resin components may also be blended within a range that does not impair the characteristics of the present invention. For example, polycarbonate oligomers made from bisphenol A or tetrabromobisphenol A can be used to improve moldability, flame retardancy, and surface properties, and heat-resistant polyesters such as polyester carbonates and polyarylates (e.g., trade names: U Polymer, Unitika ■) For improving heat resistance, it is possible to incorporate

In preparing the thermoplastic resin composition of the present invention,
Any conventionally known method may be used, and methods of kneading using an extruder, Banbury mixer, rolls, etc. may be selected as appropriate.

〔Example〕

Hereinafter, it will be explained by examples and comparative examples, but "%"
and "molecular weight" are based on weight unless otherwise specified.

Examples 1 to 4 and Comparative Examples 1 to 5 Aromatic polycarbonate resin made from bisphenol A (manufactured by Mitsubishi Gas Chemical Co., Ltd., trade name Newpiron S-2000, molecular weight 2
5,000), ABS resin (Japan Synthetic Rubber 01
Manufacturer, product name: JSRABS 35 and JSRABS
42) & acrylic acid ester graft copolymer (
Manufactured by Kureha Chemical ■, product name: HIA-15 and Kyu-23
) was added to a blender at the ratio shown in Table 1 and mixed for 30 minutes.

The resulting mixture was fed to a 40-meter vented extruder.
The mixture was then melted and kneaded at a cylinder temperature of 250°C to form pellets. The pellets were dried at 120°C15 in a hot air dryer.
After drying for more than an hour, a test piece for measuring physical properties was molded by injection molding. The test results are shown in Table 1.

For comparison, aromatic polycarbonate resin alone (comparative example -
1), Composition of aromatic polycarbonate resin and AB, S resin (Comparative Example-2), Aromatic polycarbonate resin and MBS resin (Japan Synthetic Rubber @Masusei, trade name, JSRM
BS 67) composition (Comparative Example-3), aromatic polycarbonate resin and acrylic acid ester graft copolymer (Comparative Example-4), and aromatic polycarbonate resin, A
BS resin and MAS resin (manufactured by Mitsubishi Rayon ■, product name;
Regarding the composition of Metablen W 529) (Comparative Example-5), pellets and test pieces were prepared in the same manner as in the examples, and physical properties were measured. The test results are shown in Table 1.

[Operation and effects of the invention]

As is clear from the above detailed description, Examples, and Comparative Examples, the composition of the present invention is made of polycarbonate resin-ABS
It can be seen that the impact resistance is significantly superior to that of the composition, and the moldability is equal to or better than that of the composition, making it extremely well-balanced and practical.

Furthermore, among each item in the table, lhe (had a chestnut appearance.

Claims (1)

[Scope of Claims] A, 40 to 80 wt% of aromatic polycarbonate resin, B, 100 to 10 wt% of conjugated diene rubber-aromatic vinyl-vinyl cyanide graft copolymer and aromatic vinyl-
Mixture 20 with vinyl cyanide copolymer 0 to 90 wt%
~60wt%, and C, acrylic acid ester graft copolymer 1~15w
A thermoplastic resin composition characterized in that it contains t%.