Synthesis method and application method of medium and low temperature heat-expandable microspheres

Abstract

The present invention discloses a synthesis method of low-medium temperature thermal expansion microspheres. The synthesis method comprises: adding a foaming agent to a water system dispersion medium containing a dispersion stabilizer, carrying out suspension polymerization on a monomer mixture adopting an acetonitrile monomer and an olefin monomer as main materials to prepare a shell of a thermoplastic copolymer with a low glass transition temperature, and encapsulating the foaming agent into the shell to obtain the surface-functionalized thermally-foamable expansion microspheres, wherein the initial particle size of the expansion microspheres is 6-11 mum, the initial foaming temperature is low than 110 DEG C, and the concentrated foaming temperature is 110-135 DEG C. According to the present invention, the low-medium temperature thermal expansion microspheres can be adopted as the filler or the foaming agent so as to be well combined with the base resin; and after being heated, the coated acrylic resin polymer shell is softened, the liquid state alkane compound in the internal becomes the gas so as to expand, and the volume is expanded to 30-40 times the original volume so as to effectively achieve effects of filling, part difference reduction and density reduction, such that the lightweight on the leather and the synthetic leather is particularly and easily achieved, and good effects are provided for leather filling and mending.

Description

technical field [0001] The present invention relates to a thermally expandable microsphere, specifically a method for synthesizing a medium-low temperature expandable microsphere with a surface modification group, and the use of the microsphere as a filling and foaming agent. Compositions, and methods of application in the leather industry and beyond. Background technique [0002] Heat-expandable microspheres are tiny spherical plastic particles composed of a polymer shell and the gas wrapped in it. When heated to a certain temperature, the thermoplastic shell softens, the gas inside the shell expands, and the volume of the microsphere is Dozens of times the increase. Heat-expandable microspheres having a thermoplastic resin outer shell and a foaming agent sealed inside are generally called heat-expandable microcapsules. As the thermoplastic resin, generally, vinylidene chloride-based copolymers, acrylonitrile-based copolymers, and acrylate-based copolymers can be used. A...

AI Technical Summary

Problems solved by technology

Although isobutane as a foaming agent can meet the current requirements of low-boiling foaming agents for expanded microspheres in the leather industry, isobutane as a foaming agent needs to be encapsulated into thermoplastic resins at lower temperatures or high pressures In the middle, the equipment requirements are relatively high, and the input cost is large

At the same time, since leather is composed of natural protein fibers tightly woven in three-dimensional space, the damaged part is usually the damage of the fiber. The surface of ordinary commercial expansion microspheres has no modification groups. After the repair, the microspheres, leather fibers and repair resin There is no force between them, after repeated use, the disabled parts are easy to break, exposing the original defects

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