Binder for injection molding and composition containing same for manufacturing molding objects

Abstract

The present invention proposes a binder for injection molding, which comprises a polyolefin with maleic anhydride groups accounting for about 3 to about 20% by weight, a polyolefin compound accounting for about 30 to about 40% by weight, The polyoxymethylene accounts for about 5 to about 20% by weight, the stearic acid accounts for about 1 to about 5% by weight, and the wax accounts for about 35 to about 60% by weight. The bonding agent for injection molding of the present invention is characterized in that polyolefins with maleic anhydride groups are bonded with polyolefin compounds and polyoxymethylene to improve the compatibility between the components of the bonding agent and prolong its thermal cracking time. Achieve the effect of reducing the defect of the object and improving the accuracy and consistency of its size.

Description

technical field [0001] The invention relates to a bonding agent for injection molding, especially a bonding agent for metal powder or ceramic powder injection molding. Background technique [0002] Powder injection molding is a part manufacturing technology that combines plastic injection molding and powder technology, which can be divided into metal powder injection molding (Metal Injection Molding, MIM) and ceramic powder injection molding (Ceramic Injection Molding, CIM) Two major application areas, this technology has the advantages of good surface condition, fast molding cycle, high precision and uniform quality, suitable for mass production of complex shapes and can reduce subsequent processing, etc., so it has been widely valued by the industry. The basic steps of powder injection molding are to add metal powder or ceramic powder to the binder, use the binder as the carrier, mix (blending) at an appropriate temperature to form the material to be shaped, and then injec...

AI Technical Summary

Problems solved by technology

However, the polymers used in multi-component binders usually have the characteristics of crystalline (such as polyoxymethylene (POM)) and amorphous (polyethylene (polyethylene, PE)), because of the difference in properties and structure The difference affects the compatibility between each other, resulting in uneven composition of the binder

Such inhomogeneity will cause (1) lack of good fluidity of the material to be molded, increase the time required for the manufacturing process, and in the case of complex injection molded parts, even cause incomplete mold filling; and (2) In the subsequent degreasing process, the injection-molded green embryo will have defects (such as deformation) due to the inconsistent rate of thermal decomposition

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