Bumper material with low linear expansion coefficient and preparation method of bumper material

Abstract

The invention provides a preparation method of a bumper material with a low linear expansion coefficient. By means of the method, the modified bumper material has the low linear expansion coefficient and simultaneously keeps an excellent mechanical property. The bumper material comprises components in parts by mass as follows: 40-90 parts of polypropylene resin, 5-30 parts of inorganic filler, 5-30 parts of styrene elastomer without double bonds and 0.2-0.4 parts of an antioxidant. The bumper material prepared through blending and extrusion of the components has the low linear expansion coefficient and the excellent mechanical property, the size stability of the bumper can be effectively improved, the assembly accuracy of the bumper is improved, and the regional limitation to production and assembly of the bumper is overcome.

Description

1. Technical field: [0001] The invention relates to a preparation method of modified polypropylene, in particular to a low linear expansion coefficient bumper material and a preparation method thereof. 2. Background technology: [0002] Polypropylene (PP) has the advantages of low density, excellent mechanical properties, good stress crack resistance, fatigue yield resistance and chemical resistance, and has the advantages of cheap price, easy processing and molding, recycled and recyclable, etc. It has been widely used, especially in the automotive industry, household appliances and machinery fields. However, due to the poor low temperature resistance and low rigidity of polypropylene materials, it cannot meet the requirements for use in interior and exterior parts of automobiles, so it must be modified. The main modification methods of polypropylene include elastomer-toughened polypropylene modification; inorganic filler-filled reinforced polypropylene modification; and t...

AI Technical Summary

Problems solved by technology

Since the size of the automobile bumper made of polypropylene composite material is affected by the temperature and the shrinkage rate of the material itself, the size change (linear expansion) of the ordinary bumper material with the temperature change is relatively large, which is not stable enough.

[0004] The current method to reduce the linear expansion coefficient of bumper materials is to add a large amount of inorganic rigid particle fillers. However, although the linear expansion coefficient of inorganic rigid particles is very low, adding them to the bumper material can only effectively reduce the shrinkage of the bumper material. , the linear expansion coefficient of the bumper material is reduced by a small amount, and the size of the bumper made by injection molding of this material still changes greatly with the temperature, which cannot meet the requirements of use; on the other hand, adding a large amount of inorganic fillers will cause the impact toughness of the bumper decline, reduced mobility

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