Study On Preparation And Application Of Waterborne Polyurethane For Denim Printing Paste

This paper is about the application and exploration of waterborne polyurethane adhesives in denim.Denim as a special printing product,need to meet the good Enzyme Stone Wash fastness,high gloss,comfortable and other properties.The adhesive for denim printing paste has to face the challenges.To overcome the shortcoming of poor Enzyme Stone Wash fastness of general pigment printing products.The adhesive should satisfy both the characteristics of good water resistance,high mechanical strength.Most of the traditional pigment printing adhesive is acrylic(PA),which has the advantages of softness,good water resistance and low price.However,the mechanical strength is not so high,and the stone washing process is likely to cause the printing film to be scratched.One of the general pigment printing adhesives is Waterborne polyurethane(WPU),which has excellent mechanical strength and wear resistance,but poor water resistance of the film.In order to solve the above problems,this paper blends polyester glycol,internal crosslinking agent,acrylate for modifying the waterborne polyurethane adhesive,which has good water resistance,high mechanical properties and excellent gloss.4,4 '-di cyclohexyl methane diisocyanate(HMDI),polyethylene tetrahydrofuran ether glycol(PTMG-2000),poly(adipic acid glycol ester diol(PEA-1000)as raw material,dihydroxy methyl propionic acid(DMPA)as hydrophilic chain extender,ethylenediamine(EDA)as chain extender,and triethylamine(TEA)as neutralizing agent in the paper.We obtain the polyether/polyester mixed copolymerized waterborne polyurethane emulsion through Polymerization and emulsification.We explore the effect of polyester/polyether ratio,R value,DMPA dosage,ethylenediamine chain extension on emulsion properties,film properties and various properties for denim printing.The results show that when the ratio of polyether/polyester is 3:1,R value is 1.5,DMPA dosage is 9%,and ethylene diamine chain extension is 75%,the comprehensive performance of the adhesive is best.Control the optimum values of polyether/polyester ratio,R value,DMPA dosage and chain extension.Trihydroxy methylpropane(TMP)was used as the internal crosslinking agent for internal crosslinking modification of polyether/polyester hybrid WPU.Try to find the best value for TMP.The results show that When the TMP dosage is 1.5%,the overall performance of the adhesive is optimal.In addition,a polyether/polyester blended internal crosslinked WPU modified internally crosslinked polyether/polyester blended acrylic-waterborne polyurethane(WPUA)emulsion was obtained by using hydroxyl ethyl methacrylate(HEA)as the coupling agent,butyl acrylate(BA)as the modified monomers.We explore the effect of the proportion of BA in the total amount of polyurethane monomer on the performance of adhesives.The results show that when the amount of BA is 20%,the overall performance of the adhesive is best.At last,this paper also optimizes the coating formulation of denim printing paste.We used PU thickener 406,when the paste viscosity is 20000 m Pa.s,the amount of aziridine is 1.5%,the amount of silicone feel agent is 2%,the printing effect is the best.15 images,31 tables,54 references.