High-gloss PTFE (polytetrafluoroethylene) anti-drop agent and preparation method thereof

Abstract

The invention relates to a high-gloss PTFE (polytetrafluoroethylene) anti-drop agent and a preparation method thereof. The preparation method includes: 1), adding a small amount of an emulsified monomer A solution to a PTFE emulsion and performing irradiation treatment on the PTFE emulsion in high energy ray, and grafting a small number of monomers on the surface of PTFE particles; 2), in the absence of oxygen, initiating monomer B to perform polymerization reaction in the treated PTFE emulsion by the aid of an initiator and adding a cross-linking agent at a later stage to form nuclear-shell nano PTFE composite particles with PTFE particles as nuclears and a polymer as a shell; 3), filtering the modified PTFE emulsion and subjecting a filtrate to spray drying to obtain the high-gloss PTFE anti-drop agent. With the method, under the condition that no dispersants or compatibility agents are added, the anti-drop agent can be well-dispersed in thermoplastic resin with good compatibility, and light transmission, glossiness and the like of matrix resin are unaffected by the anti-drop agent dispersed in engineering plastics of PA, PC and the like.

Description

technical field [0001] The invention relates to a high-gloss PTFE anti-dripping agent and a preparation method thereof. Background technique [0002] Anti-dripping agent products are developed from the continuous improvement of plastic flame retardancy and modification requirements. In the early days, products such as chlorinated polyethylene and silicone rubber were used, but there were problems such as environmental protection, operability and migration, and were gradually replaced by high molecular weight PTFE. Instead, become the mainstream of the market. It uses the fiber-forming principle of high-molecular-weight amorphous PTFE to form a network structure during the extrusion process to enhance the melt elastic strength of the polymer to achieve the effect of anti-dripping. In theory, various forms of high-molecular-weight amorphous Both PTFE can play a role. Crystalline PTFE and high-temperature sintered PTFE cannot be used for anti-dripping due to their insolubility...

AI Technical Summary

Problems solved by technology

[0008] (4) polytetrafluoroethylene aqueous dispersion: CN98106922 discloses adding the method of adding a vacuum vent to the extruder to add polytetrafluoroethylene aqueous dispersion to obtain long-diameter relatively large fine fibers and local cross-network structures, which partially solves the problem Addition and surface defects, but the fiber-forming effect is unstable, and moisture has adverse effects on the mechanical properties of resins such as PET, PC, and PA.

[0009] The existing domestic technology is immature, the process is complicated and the product quality is not good, the transparency is reduced and there are scratches on the surface

Foreign countries mainly use 3M in the United States, Daikin in Japan, and Hanna in South Korea. They mainly use suspension polymerization to make nano-scale PTFE anti-dripping agents. The product quality is good, but the process is complicated.

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