JP2565689B2 - Thermoplastic resin composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to a novel thermoplastic resin composition having excellent moldability.

(Prior art and its problems) Conventionally, it has been proposed to add an ABS resin to a polycarbonate resin to reduce the price of the polycarbonate resin and improve the thickness dependency of the moldability and the impact strength (for example, Japanese Patent Publication No. 38-
15225, Japanese Examined Patent Publication No. 39-71, Japanese Examined Patent Publication No. 42-11496, etc.), and some effects have been obtained.

However, it is hard to say that it is inevitably sufficient to mold a large-sized thin-walled molded product, etc. although it is certainly improved when compared to the polycarbonate resin alone when limited to the moldability, Further improvement in moldability is required.

(Structure of the Invention) In view of such a situation, the present inventors have made earnest studies on the improvement of the moldability of the composition of the polycarbonate resin and the ABS resin, and as a result, the polycarbonate resin and the ABS resin have a certain amount as a third component. Of caprolactone-modified styrene
The inventors have found that the addition of the allyl alcohol copolymer resin can remarkably improve the moldability without substantially impairing the heat resistance and impact resistance, which are the characteristics of the above resin composition, and have reached the present invention.

That is, the present invention provides (A) a polycarbonate resin of 40 to 85 wt% (B) in the presence of a conjugated diene rubber, two or more kinds selected from aromatic vinyl compounds, vinyl cyanide compounds and unsaturated carboxylic acid alkyl ester compounds. Graft polymer obtained by polymerizing a compound 10 to 50 wt% (C) Caprolactone-modified styrene / allyl alcohol copolymer resin having a caprolactone content of 60 wt% or less
It is a thermoplastic resin composition comprising 1 to 15 wt% and having excellent moldability.

The polycarbonate resin used in the present invention is an aromatic polycarbonate resin having an aromatic residue in the main chain. Generally, polymers or copolymers of bisphenols such as 2.2-bis (4-oxyphenyl) alkane type, bis (4-oxyphenyl) ether type, bis (4-oxyphenyl) sulfone type, sulfide type or sulfoxide type Although a polymer is used, halo-substituted bisphenols may be used depending on the purpose. It may also be a mixture of these polymers.

Regarding the manufacturing method and type of polycarbonate resin, "Polycarbonate resin" issued by Nikkan Kogyo Shimbun (Showa 44)
(Published September 30, 2013).

The graft polymer used in the present invention is an emulsion polymerization method in which two or more compounds selected from aromatic vinyl compounds, vinyl cyanide compounds and unsaturated carboxylic acid alkyl ester compounds are present in the presence of a conjugated diene rubber. It is a graft polymer obtained by polymerization by a known polymerization method such as a bulk polymerization method, a bulk-suspension polymerization method and an emulsion-suspension polymerization method. still,
Such a graft polymer may be an ungrafted copolymer produced at the time of graft polymerization or the above-mentioned compound 2 produced separately.
Copolymers of more than one species can be included.

There is no limitation on the composition ratio of the graft polymer, but from the viewpoint of the physical properties of the final composition, the conjugated diene rubber 5
˜70 wt%, aromatic vinyl compound 20 to 70 wt%, vinyl cyanide compound and / or unsaturated carboxylic acid alkyl ester compound 0 to 50 wt%.

The conjugated diene rubber constituting the graft polymer is polybutadiene, butadiene / styrene copolymer, butadiene / acrylonitrile copolymer and the like, and any combination thereof may be used.

The aromatic vinyl compound is styrene, α-methylstyrene, dimethylstyrene, vinyltoluene, etc., and the vinyl cyanide compound is acrylonitrile, methacrylonitrile, etc., and the unsaturated carboxylic acid alkyl ester compound is Examples thereof include methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, hydroxyethyl acrylate and hydroxyethyl methacrylate.

The caprolactone-modified styrene / allyl alcohol copolymer resin used in the present invention is a product obtained by addition-polymerizing ε-caprolactone in the presence of a styrene / allyl alcohol copolymer, and has a caprolactone content of 60 wt%.
It is as follows. An example of such a resin is disclosed in
It can be synthesized by the method described in 57-155231.

If the content of caprolactone exceeds 60% by weight, the heat resistance is greatly reduced, which is not preferable.

A thermoplastic resin composition of the present invention comprises the above-mentioned polycarbonate resin (A), a graft polymer (B) and a caprolactone-modified styrene / allyl alcohol copolymer resin (C) having a caprolactone content of 60 wt% or less,
And the composition ratio is (A) 40-85wt%, (B) 10-50wt%
%, (C) 1 to 15 wt%.

If the polycarbonate resin (A) is less than 40 wt%, heat resistance is poor, and if it exceeds 85 wt%, workability is poor, which is not preferable.

When the graft polymer (B) is less than 10 wt%, impact resistance,
Workability is poor, and if it exceeds 50 wt%, heat resistance is poor, which is not preferable.

Caprolactone-modified styrene / allyl alcohol copolymer resin (C) having a caprolactone content of 60 wt% or less
If it is less than 1 wt%, there is no effect of improving the formability, and 15 wt%
If it exceeds, the heat resistance is greatly reduced, which is not preferable.

In producing the thermoplastic resin composition of the present invention, a mixing method used for ordinary polymer blending, for example, a general mixer such as an extruder or a Banbury mixer may be used.

Further, the thermoplastic resin composition of the present invention may contain various additives such as dyes and pigments, flame retardants, antioxidants, ultraviolet absorbers, release agents and fillers.

Example Polycarbonate resin, ABS resin and caprolactone-modified styrene / allyl alcohol resin synthesized by the following method were thoroughly mixed using a mixer at a ratio shown in Table 1, and then a single-screw extruder (cylinder set temperature 260
Various pellets were obtained by melt-kneading at (° C).

Using the pellets obtained, injection molding (cylinder setting) a test piece for measuring heat distortion temperature (1/4 inch thickness) and a test piece for measuring Izod impact strength (1/4 inch thickness cutting notch) by the usual method. The temperature was 240 ° C. to 260 ° C.) and the evaluation was performed. Extruded pellets were used for measuring the melt flow rate (moldability). The results are shown in Table 1.

* Resin used (A) Polycarbonate resin Mitsubishi Gas Chemical Co., Ltd., trade name Iupilon S-3000 (bisphenol A type polycarbonate) (B) ABS resin Nippon Synthetic Rubber Co., Ltd. trade name DP-10 (styrene / acrylonitrile = 75/25) , Butadiene rubber content, 25%) (C) Caprolactone modified styrene / allyl alcohol resin Monsanto's styrene / allyl alcohol resin, trade name RJ-101 is melted in a flask, dehydrated and dried under reduced pressure, and then ε- Add caprolactone and tetrabutyl titanate as a catalyst to 10ppm, and at 150 ℃ for 8hr
Three kinds of resins were obtained by variously changing the reaction ratio of RJ101 and ε-caprolactone, which were reacted by heating. RJ-101 ε-caprolactone ASO 20 80wt% 20wt% ASO 50 50 50 ASO 80 20 80 * Test method (A) Melt index 240 ° C, 5kg load under melt flow rate ASTM-D
It was measured according to -1238.

(B) Heat distortion temperature It was measured according to ASTM-D-648. Test piece thickness 1/4 inch, no annealing, measurement load 18.56 kg / cm ² (C) Izod impact strength Measured according to ASTM-D-256 in an air-conditioned room adjusted to 23 ° C. and 65% RH.

(Effects of the Invention) As is clear from the examples, the composition of the present invention has a higher viscosity than conventional polycarbonate resin and ABS resin compositions.
Due to its excellent moldability, large-sized molded products and thin-walled molded products, which are impossible or limited by conventional compositions, such as various types
It can be applied to OA machine housings.

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Claims (1)

(57) [Claims] 1. Polycarbonate resin (A) 40 to 85 wt% (B) In the presence of a conjugated diene rubber, two or more kinds selected from aromatic vinyl compounds, vinyl cyanide compounds and unsaturated carboxylic acid alkyl ester compounds. Graft polymer obtained by polymerizing a compound 10 to 50 wt% (C) Caprolactone-modified styrene-allyl alcohol copolymer resin having a caprolactone content of 60 wt% or less 1
~ 15wt% thermoplastic resin composition