A kind of stress whitening resistant polypropylene composition and its preparation method

Abstract

The invention discloses a stress whitening resistant polypropylene composition and a preparation method thereof. The stress-whitening-resistant polypropylene composition comprises the following components calculated by weight percentage: 35%-82% polypropylene resin; 2%-12% compatibilizer; 5%-15% stress-whitening-resistant agent; 10%-40% filler; 0.2%-1.0% antioxidant; 0.2%-1.0% processing aid; the polypropylene resin is a mixture of homopolymerized polypropylene and random copolymerized polypropylene; The whitening agent is a mixture of polyethylene and thermoplastic elastomer; the compatibilizer is a graft polymer of polypropylene and unsaturated carboxylic acid or its anhydride. The stress-whitening-resistant polypropylene composition of the present invention has both good comprehensive mechanical properties and good stress-whitening resistance, and can be applied to the fields of household appliances, toys, auto parts, electric tools and the like.

Description

technical field [0001] The invention relates to the technical field of polypropylene modification, in particular to a stress-whitening-resistant polypropylene composition and a preparation method thereof. Background technique [0002] Polypropylene (PP) is widely used due to its low price, easy processing, low density, chemical corrosion resistance and excellent physical and mechanical properties, and it has become the fastest growing general-purpose plastic. However, due to its own structural characteristics, PP has low notched impact strength. At the same time, PP is susceptible to stress whitening due to external forces such as stretching, bending, and impact during use. In severe cases, it will also affect the performance and quality of the product. Therefore, in some application fields such as household appliances, toys, auto parts and electric tools, PP is required to have good impact strength and excellent stress whitening resistance. Therefore, many patents solve th...

AI Technical Summary

Problems solved by technology

However, due to its own structural characteristics, PP has low notched impact strength. At the same time, PP is susceptible to stress whitening due to external forces such as stretching, bending, and impact during use. In severe cases, it will also affect the performance and quality of the product. Quality, so in some applications such as household appliances, toys, auto parts and electric tools, PP is required to have good impact strength and excellent stress whitening resistance

Therefore, many patents solve the problems of low notched impact strength and stress whitening of polypropylene in various ways.

For example, the patent CN101709124A discloses a folding-resistant and anti-stress-whitening polypropylene material, which improves the toughness and stress-whitening resistance of the material by adding elastomers and self-made anti-stress-whitening masterbatches to the high-impact polypropylene substrate , although the material described shows very high impact resistance, the amount of copolymerized polypropylene is too much, resulting in a serious decrease in the rigidity of the material, and the resistance to stress whitening is not as high as expected

Patent CN101058655A discloses a filled polypropylene material with resistance to stress whitening and stress cracking. Polyethylene is used to improve stress whitening, but it uses block copolymerized polypropylene, and the amount of copolymerized polypropylene is too much, resulting in the material's resistance to Stress whitening is not great