JP2983924B2 - Thermoplastic resin molding - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermoplastic resin molded article having excellent heat resistance and impact resistance.

[0002]

2. Description of the Related Art A thermoplastic resin composition comprising a styrene resin and an aromatic polyether resin has excellent physical properties,
Particularly, because of its excellent moldability, it is widely used as a material for automobiles, electronic / electrical, mechanical or household parts. In recent years, along with the expansion of applications, demands for higher performance, especially for improvement in heat resistance and impact resistance, have been increasing.

Hitherto, as a thermoplastic resin composition having improved heat resistance, for example, a composition containing an aromatic phosphate ester has been known (Japanese Patent Publication No. 53-418, Japanese Patent Application Laid-Open No. Sho 51-418). No. 73248), it is necessary to incorporate a larger amount of a phosphoric acid ester as the content of the aromatic polyether-based resin decreases, and as a result, the plasticizing action of the aromatic polyether-based resin by the phosphate ester increases. There is a drawback that it is unavoidable to do.

[0004] In addition, there has been known a compound in which an organic halide and antimony trioxide are used in combination (Japanese Patent Laid-Open No.
JP-A-8-7945, JP-A-51-74038,
JP-A-52-128946) has the problems of lowering the impact resistance of the resin and corroding the molding die due to generation of hydrogen halide.

[0005]

DISCLOSURE OF THE INVENTION The present invention provides an inexpensive, heat-resistant and impact-resistant material that does not use special additives such as conventional flame retardants such as phosphoric acid esters and halides that have such disadvantages. The purpose of the present invention is to provide an excellent thermoplastic resin molded product.

[0006]

The present inventor has conducted various studies to develop a thermoplastic resin molded product having the above-mentioned preferable characteristics. As a result, the present inventors have found that a styrene-based polymer having a specific stereoregularity has been identified. It has been found that the purpose can be achieved by molding a resin composition comprising the aromatic polyether-based polymer and a specific impact strength improver in a specific ratio, and based on this finding, Invented the invention.

That is, the present invention provides a styrene polymer having a syndiotactic structure and poly (2,6-dimethylphenylene-1,4-ether) in a weight ratio of 1:10.
To a ratio of 10: 1 to 10: 1, and a styrene-butadiene block copolymer or a hydrogenated styrene-butadiene block copolymer in a proportion of 50% by weight or less and 100/11% by weight or more based on the total amount of the composition. An object of the present invention is to provide a thermoplastic resin molded article having an Izod impact strength (notched) of 10 kg · cm / cm or more and a Vicat softening point of 200 ° C. or more obtained by molding a resin composition containing an impact strength improver.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION In a resin composition used as a raw material for molding a thermoplastic resin molded article of the present invention, a styrene polymer having a syndiotactic structure is used as one of its components. is intended a phenyl group in the molecular chain it is mainly composed of a styrene polymer or a substituted styrene polymer having a structure in which three-dimensionally alternately arranged along the main chain, which is ¹³ C-NMR
It can be easily known by analysis. Examples of the styrene-based polymer having such a structure include polystyrene, poly (alkylstyrene), poly (halogenated styrene), poly (alkoxystyrene), poly (benzoylstyrene) polymerized using a Ziegler catalyst, and the like. Copolymers containing styrene, alkylstyrene, and halogenated styrene as main components can be exemplified. These may be used alone or in combination of two or more.

Next, poly (2,6-dimethylphenylene) used as the other component of the resin composition
1,4-ether) has the formula

Embedded image (Wherein R is a methyl group).

In this resin composition, a styrenic polymer having a syndiotactic structure and a poly (2,6-
Dimethylphenylene-1,4-ether) in a weight ratio of 1:10 to 10: 1. If the amount of the styrene-based polymer having a syndiotactic structure is smaller or larger than this, the improvement in heat resistance becomes insufficient. The preferred ratio of both is in the range of 1: 4 to 4: 1.

In this resin composition, it is necessary to further blend an impact strength improver comprising a styrene-butadiene block copolymer or a hydrogenated styrene-butadiene block copolymer with the polymer component. By doing so, impact resistance as well as heat resistance can be improved. It is necessary that the compounding ratio of the impact resistance improver be 50% by weight or less and 100/11% by weight or more based on the total amount of the composition. If this proportion exceeds 50% by weight, the heat resistance decreases.

If necessary, the above resin composition may contain additives usually used in general thermoplastic resins, ie, lubricants, plasticizers, various stabilizers, dyes, pigments, as long as the effects of the present invention are not impaired. Organic or inorganic fillers and the like can be added.

The above-mentioned resin composition is obtained by blending necessary components. The method of blending is a generally used method such as melt kneading using an extruder, kneading using a Banbury mixer or a roll. Can be used.

The thermoplastic resin molded product of the present invention is formed by molding such a resin composition by injection molding, etc.
It is obtained as having an Izod impact strength (notched) of not less than g · cm / cm and a Vicat softening point of not less than 200 ° C.

[0015]

Next, the present invention will be described in more detail by way of examples.

REFERENCE EXAMPLE 4 l of toluene and 1 l of trimethylaluminum were placed in an autoclave having an inner volume of 10 l replaced with an inert gas.
Mol, 1 mol of methylalumoxane and 0.5 mmol of bis (cyclopentadienyl) titanium dichloride were added. Next, 1 liter of styrene was added and a polymerization reaction was carried out at 50 ° C. for 6 hours. After completion of the reaction, the reaction was stopped by pouring the reaction product into hydrochloric acid / methanol, and the produced polymer was separated by filtration and dried. 72 g of polystyrene obtained as a result
Met. The insoluble portion of this polystyrene was 90% by weight of methyl ethyl ketone, and the stereoregularity of the insoluble portion was ¹³ C.
-As a result of NMR spectrum analysis, it was found to have a syndiotactic structure of 99% or more.

[0017] 100 parts by weight of polystyrene having a syndiotactic structure obtained in Example 1 Reference Example, poly η _sp / c = 0.64 (2,6-
A mixture consisting of 100 parts by weight of dimethylphenylene-1,4-ether) and 30 parts by weight of a styrene-butadiene block copolymer was melt-kneaded at 250 to 310 ° C. using a twin-screw extruder to obtain a resin composition. Table 1 shows the physical properties measured for the samples obtained by injection molding.

Example 2 In place of 30 parts by weight of the polystyrene and styrene-butadiene block copolymer of Example 1, 20 parts by weight of a polymethylstyrene having a syndiotactic structure and 20 parts by weight of a hydrogenated styrene-butadiene block copolymer (based on the total amount of the composition) 100/11% by weight) to obtain a resin composition in the same manner as in Example 1. Table 1 shows the physical properties measured for the samples obtained by injection molding.

Comparative Example 1 A resin composition was obtained in the same manner as in Example 1 except that the styrene-butadiene block copolymer was not used.
Table 1 shows the physical properties measured for the samples obtained by injection molding.

Comparative Example 2 A resin composition was obtained in the same manner as in Example 2 except that no hydrogenated styrene-butadiene block copolymer was used. Table 1 shows the physical properties measured for the samples obtained by injection molding.

[0021]

[Table 1]

[0022]

The thermoplastic resin molded article of the present invention has remarkably improved heat resistance and impact resistance as compared with the conventional thermoplastic resin molded article, and has excellent properties such as flame retardancy. It is suitable for automobiles, electronics / electricity, machines or household parts.

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) C08L 25/00-25/18 C08L 71/12 C08L 53/02

Claims (1)

(57) [Claims] 1. A styrenic polymer having a syndiotactic structure and poly (2,6-dimethylphenylene-1,
4-ether) in a weight ratio of 1:10 to 10: 1, and a styrene-butadiene block copolymer or hydrogen in an amount of 50% by weight or less and 100/11% by weight or more based on the total amount of the composition. Impact strength (notched) formed by molding a resin composition containing an impact resistance improver comprising a functionalized styrene-butadiene block copolymer of 10 kg · cm / cm or more and a Vicat softening point of 200 ° C. or more Plastic molded article.