Low-shrinkage polypropylene composite material without filling materials and preparation method thereof

Abstract

The invention discloses a low-shrinkage polypropylene composite material without filling materials and a preparation method thereof. The low-shrinkage polypropylene composite material is prepared from, by weight, 64 to 80 parts of co-polypropylene, 12 to 22 parts of metallocene polyethylene, 8 to 14 parts of a flexibilizer and 0.1 to 1 part of an anti-oxidant through mixing, extrusion and granulation. According to the invention, interaction among metallocene linear low-density polyethylene, the flexibilizer and polypropylene is employed to improve the crystallization process of polypropylene,so the problem of great shrinkage of polypropylene under the condition of no filling materials is overcome; the preparation method is simple in process, easy to operate and low in cost; and the low-shrinkage polypropylene composite material can be extensively applied to direct injection molding production of high-grade parts with high requirements on shrinkage and to re-modified basic resin.

Description

technical field [0001] The invention relates to the technical field of modified materials, in particular to a non-filled low-shrinkage polypropylene composite material and a preparation method thereof. Background technique [0002] Polypropylene has the advantages of good mechanical properties, non-toxicity, low relative density, heat resistance, chemical resistance, easy processing and molding, and low price. Through processing and modification, it can endow the resin with outstanding physical and mechanical properties, and thus replace some engineering plastics. In recent years, great progress has been made in the engineering of general-purpose plastics, and it is the fastest growing among the five general-purpose synthetic resins. The most active variety in the development of new varieties. Although polypropylene and polypropylene alloy materials are widely used in many fields, the molding shrinkage of such materials is usually between 1.0-2.0%, compared with the shrinka...

AI Technical Summary

Problems solved by technology

Although polypropylene and polypropylene alloy materials are widely used in many fields, the molding shrinkage of such materials is usually between 1.0-2.0%, compared with the shrinkage of some engineering plastics, such as ABS, which is 0.4-0.7% It is much larger, and it is greatly restricted when processing relatively precise parts. Only when the original performance is maintained or improved, and the shrinkage rate is effectively reduced, can polypropylene really replace engineering plastics

[0003] At present, there are two main methods to improve the shrinkage of polypropylene materials: one is to add inorganic fillers: this method has a certain effect, but it will lead to a decrease in the toughness of the material; the other is to add glass fibers: this method has obvious effects, but it is difficult to process Improve, and will significantly affect the appearance of the product

In addition, the density of the material is increased by adding fillers (mineral powder or glass fiber), which is not conducive to reducing the weight of automobiles, home appliances, motorcycles, etc.

[0004] The patent application number is 201010605303, which provides a low-shrinkage composite material and its preparation method. Calcium carbonate is used as a filler. Although the shrinkage rate is low, the density is relatively high, even reaching 1.2g / cm 3

Patent Publication No. CN103044781A provides a high-modulus and low-shrinkage filled polypropylene composite material, using modified nano-filler masterbatches as fillers. Although the effect of low filling and low shrinkage can be achieved, the nano-modification method is relatively Complex, not easy to mass produce

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