JP2977081B2 - Impact resistant resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a thermoplastic resin composition having excellent impact resistance and heat resistance.

[0002]

2. Description of the Related Art A thermoplastic resin composition comprising a styrene-based resin and an aromatic polyether-based resin has excellent physical properties and particularly excellent moldability, so that it can be used for automobiles, electronic / electrical, mechanical or household parts. Widely used as. 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, impact-resistant and heat-resistant material without the use of special additives such as conventional flame-retardants such as phosphate esters and halides, which have such disadvantages. The purpose of the present invention is to provide a thermoplastic resin composition having an excellent balance with the above.

[0006]

The inventor of the present invention has conducted various studies to develop a thermoplastic resin composition having the above-mentioned preferable characteristics, and as a result, it has been determined that a styrenic polymer having a specific stereoregularity can be obtained. It has been found that the object can be achieved by blending the aromatic polyether-based polymer in a specific ratio, and the present invention has been accomplished based on this finding.

That is, the present invention relates to a styrenic polymer having a syndiotactic structure and a general formula

Embedded image (Wherein, R ₁ and R ₂ are alkyl groups, and they may be the same or different from each other). An object of the present invention is to provide an impact-resistant resin composition formulated in a ratio of 1:10 to 1: 2.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the composition of the present invention, a styrene polymer having a syndiotactic structure is used as one of its components, because a phenyl group present in the molecular chain has a main chain. those which are mainly composed of styrene polymers or substituted styrene polymers having a structure in which three-dimensionally alternately arranged in which 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, the aromatic polyether polymer used as the other component of the composition of the present invention is a polymer comprising a structural unit represented by the above general formula (I),
One of these may be used, or two or more may be used in combination.

In the composition of the present invention, it is necessary to mix a styrene polymer having a syndiotactic structure and an aromatic polyether polymer in a weight ratio of 1:10 to 1: 2. . If the amount of the styrene-based polymer having a syndiotactic structure is larger than this, the heat resistance is improved, but the impact resistance is reduced. If the amount of the styrene-based polymer having a syndiotactic structure is smaller than this, the heat resistance will be significantly reduced. A suitable ratio of both is from 1: 4 to 1: 2.

The composition of the present invention is produced by blending the required components. The blending method is a generally used method such as melt kneading using an extruder, kneading using a Banbury mixer, a roll, or the like. Can be used.

[0012]

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 which was 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.

Example 1 100 parts by weight of polystyrene having a syndiotactic structure obtained in Reference Example and poly (2,6) having η _{sp / c} = 0.64
-Dimethylphenylene-1,4-ether) 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 The poly (2,6-dimethylphenylene-1,4) of Example 1
-Ether) was obtained in the same manner as in Example 1 except that the amount was 400 parts by weight. Table 1 shows the physical properties measured for the samples obtained by injection molding.

Comparative Examples 1-3 Polystyrene having a syndiotactic structure obtained in Reference Examples and the above-mentioned poly (2,6-dimethylphenylene-1,4)
-Ether) with a weight ratio of 2: 1, 4: 1,
Various resin compositions were obtained in the same manner as in Example 1 except that the mixture mixed at a ratio of 8: 1 was used instead of the mixture of Example 1. Table 1 shows the physical properties measured for the samples obtained by injection molding.

[0017]

[Table 1]

[0018]

The thermoplastic resin composition of the present invention provides a resin having not only improved impact resistance than conventional thermoplastic resins, but also characteristics excellent in balance with heat resistance. It is suitable for use as a material for automobiles, electronics / electricity, machines or household parts.

Claims (1)

(57) [Claims] 1. A styrenic polymer having a syndiotactic structure and a general formula: (Wherein, R ₁ and R ₂ are alkyl groups, and they may be the same or different from each other). An impact-resistant resin composition formulated in a ratio of 1:10 to 1: 2.