Injection molding grade physical foamed polypropylene material and preparation method thereof

Abstract

The invention provides an injection molding grade physical foamed polypropylene material and a preparation thereof. The polypropylene material is prepared by mixing, extruding, foaming and injection-molding 55-93 parts of polypropylene, 5-30 parts of high melt strength polyethylene, 2-15 parts of a compatilizer, 0-1 part of a main antioxidant, 0-1 part of an auxiliary antioxidant, 0-1 part of a light stabilizer and 0.5-1 part of a dispersing agent. By modifying the polypropylene through a certain amount of the high melt strength polyethylene, the polypropylene material disclosed by the invention improves low temperature performance and mobility; moreover, the material is foamed through supercritical nitrogen, so as to protect the melt from being broken and reduce density of a final finished product; requirements of reducing weight and guaranteeing rigidity and beautiful appearance are met.

Description

[0001] technical field [0002] The invention belongs to the technical field of polymer processing, and in particular relates to an injection molding grade physically foamed polypropylene material and a preparation method thereof. [0003] Background technique [0004] Polypropylene (PP) is a crystalline polymer with regular structure, usually white pellets or powder, odorless, non-toxic, light-weight thermoplastic resin; it has easy processing, impact strength, flexibility and electrical insulation It has the advantages of good chemical resistance and good chemical resistance, and has a wide range of applications in the automotive industry, household appliances, electronics, packaging, building materials and furniture. However, PP also has some shortcomings, such as poor cold resistance, low temperature brittleness, large shrinkage, poor creep resistance, poor dimensional stability of products and easy warping deformation, etc. Therefore, polypropylene needs to be modified...

AI Technical Summary

Problems solved by technology

[0007] Chinese patent (CN 101352923A) discloses a preparation method for extruding physically foamed polypropylene beads, which is to set an injection port in the middle of the barrel of the screw extruder, and install a sleeve-type die and die surface pelletizer on the machine head. machine, adding polypropylene foaming material and its additives into the screw extruder, and then injecting alkane foaming agent into the barrel from the injection port, wherein the weight ratio of polypropylene foaming material to alkane is 10-25%, so that the cut The granulated material foams when it enters the atmosphere; this patent adds a certain amount of small molecule alkane foaming agent during the extrusion process, but this molding method is extrusion molding, and the extruded material generally cannot be injection molded. Injection molding is also a very small part; Chinese patent (CN 102372855A) discloses a supercritical method to prepare pre-expanded polypropylene. Strength treatment, and through a special pre-foaming process, the pre-foamed polypropylene material is prepared; the preparation method mainly adopts the crosslinking of PP and PE, and at the same time increases the melting range by adding inorganic fillers and elastomers to increase the melt strength. Purpose, but the added components of this patent are complex, and the compatibility of polar and non-polar components will affect the performance stability of its foamed polypropylene material, so the matrix needs a longer surface treatment before blending