Preparation method of double self cross-linking elastic emulsion

Abstract

The invention discloses a preparation method of a double self cross-linking elastic emulsion. The method combines two post cross-linking modes: (1) adding multivalent metal ion compounds to carry out cross-linking reactions; (2) adding diacetone acrylamide into emulsion so as to make diacetone acrylamide participate in the emulsion copolymerization reactions during the emulsion polymerization process so as to introduce keto-carbonyl groups into the chains of copolymer, and then adding binary caprylic hydrazide such as adipic dihydrazide into the emulsion so as to obtain the self cross-linking elastic emulsion. A diacetone-acrylamide and binary caprylic hydrazide cross-linking system and a carboxylic acid and multivalent metal salt cross-linking system are both simultaneously induced into an acrylate emulsion polymerization system to replace an elastic emulsion system formed trough a single reactive cross-linking agent; thus the polymerization property and storage stability of emulsion are improved, the waterproof property, contamination resistant property, after-tack property, and elastic elongation rate of the surface of a coating coated by the elastic emulsion are all improved; and the coating product which adopts the two room temperature self cross-linking systems, has a good adhesive force and elasticity, and has a very good surface waterproof property.

Description

technical field [0001] The invention belongs to the field of fine chemicals, and in particular relates to a preparation method of double self-crosslinking elastic emulsion. Background technique [0002] Elastic emulsion is a general term for a type of acrylic emulsion with a long stretch rate, and has a wide range of uses in adhesives, textiles, leather, paper, latex paint and other industries. Due to the limitations of the acrylate raw material itself, the elastic emulsion has the problem of poor pressure resistance and viscosity due to its thermoplastic properties, and also has disadvantages such as poor water resistance, poor gloss, and poor stain resistance. [0003] In order to solve such problems, the commonly used method is to increase the molecular weight of the polymer through various cross-linking methods to improve its elasticity and eliminate side effects at the same time. There are two commonly used cross-linking methods: one is pre-crosslinking, one is The sec...

AI Technical Summary

Problems solved by technology

Due to the limitations of the acrylate raw material itself, the elastic emulsion has the problem of poor pressure resistance and viscosity due to its thermoplastic properties, and has disadvantages such as poor water resistance, poor gloss, and poor stain resistance.

[0003] In order to solve such problems, the commonly used method is to increase the molecular weight of the polymer through various cross-linking methods to improve its elasticity and eliminate side effects at the same time. There are two commonly used cross-linking methods: one is pre-crosslinking, one is The second is post-crosslinking. Pre-crosslinking is to add crosslinkable dibasic or polyunsaturated monomers to acrylate raw materials to directly participate in the reaction to increase molecular weight during polymerization. The disadvantage is that the increase in molecular weight reduces the adhesion to the substrate. At the same time, the addition of cross-linking monomers destroys the stability of polymerization and increases the production of gels; post-crosslinking is to add some additives after the polymerization is completed to achieve improvement by reacting with some special functional groups on the polymer chain. For the purpose of molecular weight, the general post-crosslinking is completed after the polymer is coated and before the film is completely formed, so that it does not affect the adhesion of the polymer and avoids some of its common shortcomings. The disadvantage of post-crosslinking is If the process is wrong or the raw material is not selected properly, the storage of the product will be unstable, and in severe cases, all products will be scrapped