JPH0433304B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a thermoplastic resin composition that has excellent antistatic properties, good mechanical properties, and moldability, and is used for housings of electronic and electrical equipment where dust and the like may adhere. The material is suitable for materials such as steel and cases. [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. However, 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 exhibits a short mold and crepe pattern, making it difficult to obtain a good molded product. In order to improve these shortcomings, the special public
Publication No. 15225 teaches blending ABS resin. However, although this composition has improved impact resistance and moldability, it has the drawback of having a high surface resistivity characteristic of plastics and being susceptible to dust etc. Various studies have been conducted 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 to obtain. [Means for Solving the Problems] The present invention was completed as a result of studies aimed at improving the antistatic properties and processability of polycarbonate resin. That is, the present invention provides (C) an alkyl compound represented by formula () to 100 parts by weight of a synthetic resin composition of (A) 30 to 99% by weight of an aromatic polycarbonate resin and (B) 70 to 1% by weight of an ABS resin. Sulfonate or alkylbenzene sulfonate represented by formula () R ¹ SO ₃ M ……() (In the formula, R ¹ and R ² are linear or branched alkyl groups having 8 to 22 carbon atoms, and M represents an alkali metal.)
The object of the present invention is to provide an antistatic thermoplastic resin composition comprising 0.5 to 5 parts by weight of an antistatic agent containing a polyethylene wax having an acidic group and a 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 made by reacting an 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 (=bisphenol A), tetramethylbisphenol A, tetrabromobisphenol A, bis(4-hydroxyphenyl)-p-diisopropylbenzene, hydroquinone, resorcinol, 4,4-dihydroxydiphenyl, etc. and bisphenol A is particularly preferred. In addition, to obtain a branched aromatic polycarbonate resin, phloroglucin, 4,6
-dimethyl-2,4,6-tri(4-hydroxyphenyl)heptene-2,4,6-dimethyl-
2,4,6-tri(4-hydroxyphenyl)heptane, 2,6-dimethyl-2,4,6-tri(4-hydroxyphenyl)heptene-3,4,
6-dimethyl-2,4,6-tri(4-hydroxyphenyl)heptane, 1,3,5-tri(4-
Polyhydroxy compounds such as hydroxyphenyl)benzene, 1,1,1-tri(4-hydroxyphenyl)ethane, and 3,3-bis(4-hydroxyaryl)oxindole (=isatin bisphenol) ), 5-chloroisatin, 5,7-dichloroisatin, 5-bromiisatin, etc., a part of the dihydroxy compound, for example 0.1 to 2 mol %, is replaced with a polyhydro compound.
Monovalent aromatic hydroxy compounds suitable for further adjusting the molecular weight include m- and p-methylphenol, m- and p-propylphenol, p-
Bromophenol, p-tert-butylphenol and p-long chain alkyl substituted phenol are preferred. The aromatic polycarbonate resin is typically a bis(4-hydroxyphenyl)alkane dihydroxy compound, especially bisphenol A.
Examples include polycarbonate whose main raw material is 2.
Also included are polycarbonate copolymers obtained by using a combination of more than one type of aromatic dihydroxy compound, and branched polycarbonates obtained by using a small amount of a trivalent phenol compound. 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 to this 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. There is no particular restriction on the composition ratio of the conjugated diene rubber and the graft polymerization compound in the graft polymer, but 5 to 70% by weight of the conjugated diene rubber and the graft polymerization compound 95
Preferably it is ~30% by weight. 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% by weight of aromatic vinyl and 50 to 20% by weight of vinyl cyanide. 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. It is preferable that the viscosity is 30% in dimethylformamide.
A range of 0.60 to 1.50 at °C 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. 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-halogenated Examples include acrylonitrile, and acrylonitrile is particularly good. In addition,
Aromatic vinyl and vinyl cyanide may be partially combined with other vinyl compounds, such as (meth)acrylates, vinyl acetate, vinyl chloride, etc., especially (meth)
Those substituted with acrylic esters are also preferred. Component (C) used in the present invention is an alkyl sulfonate represented by the formula () or an alkylbenzenesulfonate represented by the formula () R ¹ SO ₃ M ... () (In the formula, R ¹ and R ² are linear or branched alkyl groups having 8 to 22 carbon atoms, and M represents an alkali metal.)
and a polyethylene wax having acidic groups. The ratio of the polyethylene wax having acidic groups to the sulfonate compound in this antistatic agent is preferably 0.5 to 50% by weight, more preferably 2 to 25% by weight. The polyethylene wax having acidic groups in the present invention has a molecular weight (MW) 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 a monomer 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 as follows: (A) the aromatic polycarbonate resin is 30 to 30%;
99% by weight, preferably 40 to 95% by weight, and (B) 100 to 10% by weight of conjugated diene rubber-aromatic vinyl-vinyl cyanide graft copolymer and aromatic vinyl-vinyl cyanide graft copolymer. 0-90% by weight
The amount of the mixture with is in the range of 1 to 70% by weight, preferably 5 to 60% by weight. The amount of the antistatic agent (C), based on 100 parts by weight of this composition, is in the range of 0.5 to 5 parts by weight, preferably 1 to 3 parts by weight. 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. If the amount of component (B) is less than 1% by weight, the effect of improving moldability will be insufficient, and if the amount of component (C) blended is less than 0.5 parts by weight with respect to 100 parts by weight of the composition, the improvement in antistatic properties will be insufficient. enough is enough;
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 materials, and glass. Various fillers such as beads 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.
Heat resistant polyesters such as polyester carbonate and polyarylate (for example, trade name: U Polymer, manufactured by Unitika Co., Ltd.) may be blended to improve heat resistance. In preparing the thermoplastic resin composition of the present invention, conventionally known methods may be employed, and methods of kneading with an extruder, Banbury mixer, rolls, etc. are appropriately selected. [Example] Hereinafter, it will be explained using Examples and Comparative Examples.
"Parts" are by weight unless otherwise specified. Examples 1, 2 and Comparative Examples 1, 2, 3, 4 Aromatic polycarbonate resin made from bisphenol A (Teijin Kasei Ltd., Panlite L-
1250), ABS resin (Toray Industries, Inc.), Toyolax
100) and antistatic agent in the proportions shown in Table 1 were added to a blender and mixed for 30 minutes. The resulting mixture was fed into a 40 mm vented extruder and melt-kneaded at a cylinder temperature of 230 to 250°C to form pellets. This pellet is dried in a hot air dryer for 110~
After drying at 120° C. for 5 hours or more, test pieces for measuring physical properties were prepared by injection molding, and the physical properties were measured. The coloring of the resin composition when an antistatic agent was added was also investigated. In other words, using an SM color computer (Model SM-3) manufactured by Suga Test Instruments Co., Ltd., the color difference (ΔE ) was measured. The larger the value, the greater the coloring property, making it unsuitable as an antistatic agent. The test results are shown in Table 1. For comparison, polycarbonate resin alone (Comparative Example 1), a composition of polycarbonate resin and ABS resin (Comparative Example 2), and polycarbonate resin and ABS
Pellets and test pieces were prepared in the same manner as in the examples for a composition containing only oxidized low molecular weight polyethylene wax (Comparative Example 3) and a composition containing only sulfonate (Comparative Example 4), and their physical properties were determined. Measurement and resin coloring properties were investigated. 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/cm ² ,
The amount of resin flowing out from a 1 mmφ x 100 mm L nozzle at a temperature of 240°C. However, in Comparative Example 1, the temperature
The temperature is 280℃. (Unit: ×10 ^-2 cc/sec) IZ: Izot impact value, thickness 3.2mm, with notch (Unit: Kg・cm/cm) HDT: Heat distortion temperature, load 18.6Kg/cm ²

[Operation and effect of the invention]

As is clear from the above detailed description, Examples, and Comparative Examples, the composition of the present invention provides a composition with improved antistatic properties without significantly reducing the physical properties of the polycarbonate resin-ABS resin composition. The present invention provides a material suitable for housings and cases of electronic and electrical equipment where dust and the like may adhere.

Claims (1)

[Claims] 1. (C) represented by formula () based on 100 parts by weight of a synthetic resin composition of (A) 30 to 99% by weight of aromatic polycarbonate resin and (B) 70 to 1% by weight of ABS resin. or alkylbenzenesulfonate represented by the formula () R ¹ SO ₃ M ……() (In the formula, R ¹ and R ² 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 a polyethylene wax having acidic groups in an amount of 0.5 to 50% by weight based on the sulfonate compound.