JPH01266159A - Antistatic thermoplastic resin composition - Google Patents

Abstract

PURPOSE:To obtain the title composition which has excellent antistatic properties, good mechanical strength, and good moldability, and is suitable for, e.g., electrical and electronic equipment housings on which duct is apt to be deposited, by incorporating a specified antistatic agent into an aromatic polycarbonate resin/ABS resin composition. CONSTITUTION:100pts.wt. synthetic resin composition (A) consisting of 30-99wt.% aromatic polycarbonate resin and 70-1wt.% ABS resin is mixed with 0.5-5pts.wt. antistatic agent (B) containing both an alkylbenzenesulfonate of formula I (wherein R<1> is an 8-22C straight-chain or branched alkyl; M is an alkali metal) or formula II (wherein R<2> is the as R<1>; M is as defined above) and a polyethylene wax having acidic groups, thereby giving the title composition. The incorporation of component B can give a composition having improved antistatic properties without substantial reduction in the physical properties of composition A. The title composition thus obtained is suitably used for, e.g., electrical and electronic equipment housings and cases on which dust, etc. are apt to be deposited.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention relates to a thermoplastic resin composition that has excellent antistatic properties, good mechanical properties, and moldability, and is free from the risk of dust and the like adhering to it. The material is suitable for housings and cases of certain electronic and electrical devices.

[Prior art and problems to be solved by the invention] As is well known, aromatic polycarbonate resins are tough, have excellent impact resistance and electrical properties, have good dimensional stability, and have excellent transparency. Therefore, it is widely used as a useful engineering plastic. but,
Due to its high melt viscosity, it is difficult to fill molds for large molded products such as housings for electrical and electronic equipment, and molds for thin-walled molded products.
It is difficult to obtain a good molded product due to short mold and crepe pattern.

In order to improve these shortcomings, the Special Publication No. 38-15225
The publication teaches blending ABS resin. However, although this composition has improved impact resistance and moldability, it has a high surface resistivity characteristic of plastics.
It has the disadvantage that dust etc. easily adhere to it.

Various studies have been carried out to solve this drawback, but the improvement in antistatic properties is not always sufficient, and the antistatic agent decomposes the polycarbonate resin, resulting in molded products with good physical properties. The drawback was that it was difficult.

[Means to solve the problem]

The present invention was completed as a result of studies to improve the antistatic properties and processability of polycarbonate resin.In other words, the present invention consists of (A) 30 to 99% by weight of aromatic polycarbonate resin and (B) 70% by weight of ABS resin. -1% by weight of the synthetic resin composition (C) with respect to 100 parts by weight of the synthetic resin composition
) or an alkylbenzenesulfonate represented by formula (n) R1803M CI') (wherein R+ and R2 are linear or branched alkyl groups having 8 to 22 carbon atoms, and M represents an alkali metal.) and 0.5 to 5 parts by weight of an antistatic agent containing polyethylene wax having an acidic group.

The present invention will be explained in detail below.

The aromatic polycarbonate resin (A) of the present invention is an optionally branched thermoplastic polycarbonate polymer produced by reacting aromatic dihydroxy or a small amount of a polyhydroxy compound with phosgene or a diester of carbonic acid. . Examples of aromatic dihydroxy compounds include 2,2-bis(4-hydroxyphenyl)furonozane(-bisphenol A), tetramethylhysphenol A1, tetrabromobisphenol A1, bis(4-hydroxyphenyl)-p-diisopropylbenzene, Examples include hydroquinone, resorcinol, 4,4-dihydroxydiphenyl, and bisphenol A is particularly preferred. In addition, in order to obtain a branched aromatic polycarbonate resin, phloroglucin, 4,6-cymethyl-2.4.6-
tri(4-hydroxyphenyl)hebutene-2,4,
6-dimethyl-2.4.6-tri(4-hydroxyphenyl)hebutane, 2.6-dimethyl-2.4.6-
to! J (4-hydroxyphenyl)hebutene-3,
4,6-dimethyl-2,4,6-tri(4-hydroxyphenyl)hebutane, 1,3,5-toIJ(4-hydroxyphenyl)benzene, 1,1°1-)! J(4-
Polyhydroxy compounds exemplified by hydroxyphenyl)ethane, and 3゜3-bis(4-hydroxyaryl)oxindole (=isatin bisphenol)
, 5-chloroisatin, 5.7-dichloroisatin, 5
- Substituting a part of the dihydroxy compound, such as bromiisatin, for example 0.1 to 2 mol%, with a polyhydroxy compound. Monovalent aromatic hydroxy compounds suitable for further adjusting the molecular weight include m4 and p-methylphenol, m- and p-propylphenol, p-bromophenol, p-tert-butylphenol and p-long-chain alkyl substitutions. Phenol and the like are preferred. Aromatic polycarbonate resins typically include bis(4-hydroxyphenyl)alkane dihydroxy compounds, particularly polycarbonates whose main raw material is bisphenol A, which can be obtained by using two or more aromatic dihydroxy compounds in combination. Branched polycarbonate obtained by using a small amount of a polycarbonate copolymer and a trivalent phenol compound can also be mentioned. Aromatic polycarbonate resins may be used as a mixture of two or more types.

The ABS resin as component (B) of the present invention usually refers to a conjugated diene rubber-aromatic vinyl-vinyl cyanide graft copolymer alone, or an aromatic vinyl-vinyl cyanide copolymer added thereto in an amount of 90% by weight or less. It is made by blending in the amount of

The conjugated diene rubber-aromatic vinyl-vinyl cyanide graft copolymer is a graft polymer obtained by graft polymerizing an aromatic vinyl compound and vinyl cyanide as essential components to a rubbery polymer containing a conjugated diene as an essential component. It is a polymer.

The composition ratio of the conjugated diene rubber and the graft polymerization compound in the graft polymer is not particularly limited, but the conjugated diene rubber 5 to 70% by weight and the graft polymerization compound 95 to 3% by weight.
Preferably it is 0% by weight. Furthermore, there is no particular restriction on the composition ratio of monovalent vinyl to vinyl cyanide in the graft polymerization compound, but aromatic vinyl may be 50 to 80% by weight.
and vinyl cyanide in an amount of preferably 50 to 20% by weight.

In addition, there is no particular restriction on the composition ratio of aromatic vinyl and vinyl cyanide in the aromatic vinyl-vinyl cyanide copolymer, but 55 to 85% by weight of aromatic vinyl and 45 to 15% by weight of vinyl cyanide may be used. The viscosity is preferably 0.60 to 1 at 30°C in dimethylformamide.
．． A range of 50 is preferred.

The conjugated diene rubber in the above graft copolymer or copolymer includes butadiene rubber-like polymers such as polybutadiene, butadiene-styrene copolymer, butadiene-acrylonitrile copolymer, and butadiene-acrylic acid ester copolymer. One example is merging. Further, examples of aromatic vinyl include styrene, halogenated styrene, vinyltoluene, α-methylstyrene, vinylnaphthalene, etc., with styrene being particularly good, and examples of vinyl cyanide include acrylonitrile, methacrylonitrinove α-
Examples include 10genated acrylonitrile, and especially acrylonitrile is preferable. It is also preferable to substitute a part of the aromatic vinyl or vinyl cyanide with another vinyl compound, such as (meth)acrylic esters, vinyl acetate, vinyl chloride, and especially (meth)acrylic esters.

Component (C) used in the present invention is an alkyl sulfonate represented by formula (I) or an alkylbenzenesulfonate represented by formula (I[) R'SO3M
(1) (In the formula, R1 and R2 have 8 to 8 carbon atoms.
22 straight chain or branched alkyl group, M represents an alkali metal. ) and a polyethylene wax having an acidic group.

The ratio of polyethylene wax having an acidic group to the sulfonate compound in this antistatic agent is 0.5 to 50.
It is preferably 2 to 25% by weight, more preferably 2 to 25% by weight.

The polyethylene wax having an acidic group in the present invention has a molecular weight (Ml!i) of 500 to 10.000,
Those having an acid value (AV, mg/g) of 10 to 300 are desirable, and examples of acidic groups include carboxyl groups and sulfonic acid groups. Such polyethylene wax having acidic groups can be obtained, for example, by introducing acidic groups into polyethylene wax through an oxidation reaction, or by copolymerizing monomers having acidic groups during polymerization of polyethylene wax.

Further, for the purpose of improving the caking resistance of the composition of the present invention, a small amount of silicon dioxide may be used in combination.

The ratio of the resin components in the thermoplastic resin composition of the present invention is (A) aromatic polycarbonate resin is 30 to 99% by weight, preferably 40 to 95% by weight, and (B) conjugated diene rubber-aromatic vinyl - A mixture of 100 to 10% by weight of vinyl cyanide graft copolymer and 0 to 90% by weight of aromatic vinyl-vinyl cyanide graft copolymer is 1 to 10% by weight of vinyl cyanide graft copolymer.
70% by weight, preferably in the range of 5-60% by weight.

Further, the amount of the antistatic agent (C) component is in the range of 0.5 to 5 parts by weight, preferably 1 to 3 parts by weight, based on 100 parts by weight of this composition. If component (A) is less than 30% by weight, the heat resistance will not reach the level required for engineering plastics, and the dimensional stability will also be poor. (B) component is 1
If the amount of component (C) is less than 0.5 parts by weight based on 100 parts by weight of the composition, the improvement in antistatic properties is insufficient. If it exceeds 5 parts by weight, heat resistance will decrease, which is not preferable.

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 further, other resin components may be blended within a range that does not impair the characteristics of the present invention. For example, polycarbonate oligomers from bisphenol A or tetrabromobisphenol A can be used to improve moldability, flame retardancy, and surface properties, such as polyester carbonates and polyarylates (e.g., trade names:
In order to improve heat resistance, it is possible to incorporate heat-resistant polyesters such as U-polymer and Unitika@).

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

〔Example〕

The following description will be made using Examples and Comparative Examples, where "parts" are based on weight unless otherwise specified.

Example 1.2 and Comparative Example 1.2 Aromatic polycarbonate resin made from bisphenol A (Ondai Kasei, Panlite L-1250), ABS
A resin (east side, TOYOLAC 100) and an antistatic agent were placed in a blender in the proportions shown in Table 1, and mixed for 30 minutes.

The resulting mixture was fed into a 4Qmm vented extruder,
The mixture was melt-kneaded at a cylinder temperature of 230 to 260°C to form pellets. These pellets are heated to 110~120 in a hot air dryer.
After drying at ℃ for 5 hours or more, test pieces for measuring physical properties were molded by injection molding.

The test results are shown in Table 1.

For comparison, pellets and test pieces were prepared in the same manner as in Examples for polycarbonate resin alone (Comparative Example 1) and a composition of polycarbonate resin and ABS resin (Comparative Example 2), and physical properties were measured. The test results are shown in Table 1.

In addition, the description in the table is as follows.

Q value: High-grade flow tester, load 160kg/cm2
, the amount of resin flowing out from a nozzle of 1 mmφ x 100 mmL at a temperature of 240°C. However, in Comparative Example 1, the temperature was 280°C.
It is ℃. (Unit:
Unit; kg-cm/cm) HDT: heat distortion temperature,
Load: 18.6 kg/cm2 Table 1 [Operations and effects of the invention] As is clear from the above detailed description, examples, and comparative examples, the composition of the present invention significantly improves the physical properties of the polycarbonate resin-ABS resin composition. It is possible to obtain a composition with improved antistatic properties without degrading the antistatic property, and it provides a material suitable for housings and cases of electronic and electrical equipment where dust and the like may adhere.

Applicant's agent Kaoru Furutani

Claims (1)

[Scope of Claims] (C) is represented by formula (I) based on 100 parts by weight of a synthetic resin composition of (A) 30-99% by weight of aromatic polycarbonate resin and (B) 70-1% by weight of ABS resin. or alkylbenzenesulfonate represented by formula (II) R^1SO_3M...(I) ▲There are numerical formulas, chemical formulas, tables, etc.▼...(II) (In the formula, R^1 and R^2 are An antistatic agent containing 0.5 to 5 parts by weight of an antistatic agent containing a linear or branched alkyl group having 8 to 22 carbon atoms (M represents an alkali metal) and a polyethylene wax having an acidic group. preventive thermoplastic resin composition.