Preparation Of Hydroxyl Acrylate Latex And Its Properties In Wood Finishing Coatings

With the continuous popularization of the concept of green sustainable development and the continuous introduction and standardization of paint-related regulations,waterborne two-component hydroxyl acrylic coating has gradually become the focus of engineers'research.Waterborne two-component hydroxyl acrylic coating film has the advantages of high gloss,good water resistance,excellent solvent resistance,excellent adhesion and excellent flexibility of polyurethane resin,as well as excellent light and color retention and outdoor weather resistance of acrylic resin.So it is widely used in wood,automobile,plastic,floor and protection fields,etc.Waterborne two-component hydroxyl acrylic coatings include waterborne hydroxyl polyol and waterborne isocyanate curing agent.Waterborne hydroxyl polyol mainly includes hydroxyl acrylic acid dispersion,hydroxyl acrylate latex and water-soluble hydroxyl acrylate.Hydroxyl acrylate latex has low production cost,low solvent content even no solvent,excellent weather resistance and chemical resistance of the film,etc.But because of its molecular weight is too big,so that the film gloss poor fullness,and the poor stability in the preparation of latex,etc.,which greatly limits the promotion of application.In this paper,stable high gloss hydroxyl acrylate latex modified by ethyl acetoacetate methacrylate(AAEM)was prepared by emulsion polymerization,and mixed with hydrophilic isocyanate curing agent to prepare waterborne two-component hydroxyl acrylate coating,and its characterization and analysis.Finally,it was applied to the two-component acrylic wood white finish.Through performance characterization of hydroxyl acrylate latex,the effects of the variety of emulsion polymerization process,amount of emulsifier,reaction temperature(T)and monomer dripping time(t)influence on hydroxyl acrylate latex were investigated.Finally,the preparation process was optimized.It was found that the latex polymerization stability,storage stability,freeze-thaw stability and mechanical stability were prepared by pre-emulsified semi-continuous seed emulsion polymerization process,reactive anionic emulsifier,reaction temperature85?and monomer dripping time 4.0 h,and the prepared latex has small particle size and low gel rate.Next,using the optimized preparation process,through the design and optimization of the synthetic formula,the high gloss hydroxyl acrylate latex was prepared.The experimental results showed that when the dosage of molecular weight regulator was 0.3%(accounting for the total amount of monomer),the amount of carboxyl group was 1.5%,the ratio of carboxyl group methacrylic acid(MAA)/acrylic acid(AA)was 1:1,the theoretical T_g was 65?,the amount of initiator was 0.4%,the amount of functional monomer AAEM was 4%,the hydroxyl monomer was hydroxyethyl methacrylate(HEMA)and the hydroxyl content was2.5%,the waterborne two-component hydroxyl acrylate coating has good film fullness,high gloss and excellent resistance.Finally,waterborne two-component acrylic wood white top paint was prepared by using self-made high gloss hydroxyl acrylate latex as film-forming binder.The effects of the type and amount of curing agent,pigment-to-base ratio,dispersant and dispersant on the white top paint were systematically studied,and the application period of the white top paint was also discussed.The results showed that when the curing agent was Bayhydur XP 2655,(-NCO)/(-OH)was 1.5,the pigment-to-base ratio was 0.8,the dispersant was BYK-190 and the dosage was 0.50%,the film has high gloss,high hardness and excellent resistance.And the construction period of paint can be up to 5 hours.