Method for preparing acrylate/ silane coupling agent shared modified casein leather finishing agent by adopting soap-free polymerization method

Abstract

Provided is a method for preparing acrylate / silane coupling agent shared modified casein leather finishing agent by adopting a soap-free polymerization method. The method comprises the following steps: firstly, dissolving dry casein with triethanolamine and water, obtaining casein dissolved solution, adding dropwisely caprolactam solution into the casein dissolved solution, obtaining modified casein emulsion of caprolactam, then under the effect of persulfide initiator, adopting a semicontinuous seed emulsifier-free emulsion polymerization method, adding simultaneously methyl methacrylate, butyl acrylate and silane coupling agent to the modified casein emulsion of the caprolactam, and obtaining the acrylate / silane coupling agent shared modified casein leather finishing agent through free radical polymerization. According to the method for preparing the acrylate / silane coupling agent shared modified casein leather finishing agent by adopting the soap-free polymerization method, the casein is adopted to be as raw materials, health performance is good, gloss is natural, hand touch is comfortable and dry, emulgator is not added, adverse impact of the emulgator is eliminated, and the extensibility and a water resisting property of a film of the prepared acrylate / silane coupling agent shared modified casein leather finishing agent are remarkably improved.

Description

technical field [0001] The invention relates to a method for modifying a casein leather finishing agent, in particular to a method for preparing an acrylate / silane coupling agent co-modified casein leather finishing agent by a soap-free polymerization method. Background technique [0002] As one of the most widely used film-forming agents for leather finishing agents, casein has strong adhesion to leather and is not easy to fall off; and the formed film has good temperature resistance, light resistance, iron resistance, good hygienic performance, and water permeability Good steam and other advantages. However, because casein molecules contain a large number of hydrophilic groups and molecular secondary bonds, casein coatings have disadvantages such as poor water resistance, hard and brittle film formation, and poor wet rub resistance. [0003] At present, polyurethane, caprolactam, and vinyl monomers are mainly used for modifying casein, but each modified product has its ow...

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Problems solved by technology

However, due to the large number of hydrophilic groups and molecular secondary bonds in the casein molecule, the casein coating has the disadvantages of poor water resistance, hard and brittle film formation, and poor wet rub resistance.

[0003] At present, polyurethane, caprolactam, and vinyl monomers are mainly used for modifying casein, but each modified product has its own defects. Bring greater pollution; single acrylate monomer modified casein has poor water resistance or poor flex resistance (Zhang Qianling, Ren Xiangzhong, Liu Jianhong. Research status of casein graft modification[J] .China Leather,2006,35(13):47~51; Shen Xiaoqing, Lan Yunjun, Xu Xiaohong. Technical means of casein modification and performance characteristics of modified products[J].Western Leather,2009,31(13) :30~32)

In the previous research, the inventor used caprolactam and acrylate to prepare modified casein emulsion. The obtained emulsion was not easy to mold, and the flexibility of the film was improved, but its water resistance and extensibility still need to be further improved.

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