JP2005089720A - Random polypropylene rigid resin having both transparency and high impact resistance - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance impact resistance while transparency of a random polyolefin-based rigid resin is maintained. <P>SOLUTION: The transparency possessed by an SEBS itself is ensured by saturating to a degree of 60% or more double bonds of conjugated diene portions of the SEBS as a rubber post-added to the random polyolefin-based rigid resin. The impact strength of the material into which the SEBS is blended is enhanced by blending the SEBS which acts as a compatibilizer to improve its compatibility with a PP in the random polyolefin-based rigid resin and is allowed to be microdispersed into the random polyolefin. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  TECHNICAL FIELD The present invention relates to injection molded parts for automobile interior and exterior and motorcycle exterior, and more particularly, automotive dashboards, door trims, switch panels, pillar trims that require transparency or high appearance with improved pigment sharpness due to the transparency. , Bumpers, grills, motorcycle cowls, etc.

  In recent years, in order to achieve both improvement in product quality and cost reduction for automobile and motorcycle parts, there is an increasing demand for transparent resin materials having high design properties or highly sharp raw material colored resin materials added with metallic pigments and the like. . As for transparent materials, polycarbonate and acrylic resin are used for automobile applications, but the former has a problem of material price and the latter has a problem of impact resistance. On the other hand, the most commonly used polypropylene resin for automobile and motorcycle parts is a random polypropylene hard resin having transparency, but it is not adopted because of its low impact resistance. For this reason, attempts have been made to knead various rubbers such as ethylene propylene with random polypropylene hard resin. However, conventional rubber materials impair the transparency that is a characteristic of random polypropylene hard resin, leading to practical application. Not.

  The problem to be solved is to provide a blended material of random polypropylene and a rubber component having impact resistance suitable for applications such as automobile parts while maintaining transparency.

Means for solving the problem

  In the present invention, the saturation of the double bond of the conjugated diene part of SEBS or SEBC added to the random polypropylene hard resin (hereinafter referred to as saturation) is saturated by 60% or more, thereby increasing its own transparency. Even when kneaded into a random polypropylene hard resin, the transparency is not impaired. Furthermore, compatibility with the random polypropylene hard resin can also be improved, and the impact resistance of the random polypropylene hard resin is improved by being finely dispersed inside the random polypropylene hard resin during kneading or injection molding.

By adding and blending at least 1% or more of these SEBS or SEBC into the random polypropylene hard resin, the impact resistance characteristics of the random polypropylene hard resin can be improved. About transparency, the characteristic which can be satisfied with respect to a required value is maintained, without depending on a compounding ratio.
The kneading compounding agent may contain dyes or pigments and various additives as necessary, for example, an anti-aging agent, an antioxidant, a light stabilizer, a nucleating agent, an ultraviolet absorber, a release agent, and the like. .

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated further more concretely, this invention is not restrict | limited at all by these Examples, unless the summary is exceeded.

Evaluation results

FIG.

as well as

FIG.

As shown in the above, test pieces were prepared with an injection molding machine using pellets obtained by kneading and blending a random polypropylene hard resin with 60% saturated SEBS rubber, and the transparency was evaluated with an Izod impact strength and a haze meter.
As a result, it was confirmed that the Randa-Polypropylene hard resin blended with SEBS had improved impact resistance and maintained transparency.

Figure of Izod impact strength evaluation results Figure of transparency evaluation result by haze meter

Claims (1)

A transparent hard polypropylene resin having high impact resistance is obtained by kneading 1% or more of the following (A) with a random polypropylene hard resin having transparency.
The composition may contain dyes or pigments and various additives as necessary, for example, anti-aging agents, antioxidants, light stabilizers, nucleating agents, ultraviolet absorbers, release agents and the like.
(A) A hydrogenated diene copolymer having a number average molecular weight of 50,000 to 700,000, wherein the double bond of the conjugated diene moiety of the conjugated diene copolymer is saturated by 60% or more. For example, styrene ethylene butadiene styrene block copolymer (hereinafter referred to as SEBS) or styrene ethylene butadiene olefin crystal block copolymer (hereinafter referred to as SEBC).

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