Synthesis And Application Of Containing Zirconium Salt Waterborne Polyurethane Adhesive For Shoes

In this period of rapid economic development,the environmental problem get people’s attention increasingly,development of non-toxic pollution-free,excellent property waterborne polyurethane adhesives for shoes has become the need of the development of this times.Solvent-based polyurethane adhesives because of its use organic compounds as solvent,and the solvent in using process will directly to pollution environmental and harm to human health.so,instead of solvent-based polyurethane adhesives for waterborne polyurethane adhesives is non-toxic good flexibility and the advantages of easy cleaning residues after used and has been widely studied by researchers.At present,the domestic preparation of waterborne polyurethane adhesive because its structure containing hydrophilic groups,although the system stability is good,but in the film-forming process the coating of poor water resistance and solvent resistance.In order to solve this problem,currently use more is to using multifunctional of crosslinking agent.However,the introduction of this kind of crosslinking agent into the internal crosslinking method can not make the polyurethane molecular chain segment excessive crosslinking,because when the crosslinking is too large,it will directly affect the viscosity of the prophase synthesized polyurethane prepolymer,which will cause some difficulties in the water emulsification and dispersion.So in this paper,a new type of crosslinking agent ammonium zirconium carbonate(AZC)was successfully introduced in this paper,which was based on the introduction of the conventional multifunctional crosslinking agent trimethylolpropane(TMP),which is connected with the hydroxyl groups on the zirconium atom of carbonyl occurs bridging.Meanwhile,the zirconium ion contained in the AZC structure can react strongly with the carboxyl ions contained in the anionic polyurethane structure and form a associative key with larger bond energy,the very weak interaction becomes very strong.Furthermore,the compound can be used as a bonding agent between the bonding material and the adhesive coating.Therefore,the introduction ofcontaining zirconium compounds in the polyurethane structure can effectively improve the adhesive splice properties,heat resistance and water resistance of the adhesive.This paper firstly synthesis waterborne polyurethane emulsions containing carboxylic acid groups and zirconium salt with solid content(≥50%)by acetone method,effect of R value,hydrophilic chain extender dihydroxy methyl butyric acid(DMBA),crosslinking agent TMP,silane coupling agent KH-550,metal type crosslinking agent AZC,neutralization degree and neutralization way on properties of waterborne polyurethane were investigated.Finally the optimum technological conditions were determined,and then waterborne polyurethane emulsions containing carboxylic acid/sulfonic acid groups and zirconium salt with solid content(≥50%)were synthesized.At the same time,and the waterborne polyurethane adhesives were made into of the different types of waterborne polyurethane emulsions with just the right amount of additives and curing agents which for rubber-leather and leather-leather have carried on the research of sizing process,respectively.And with the optimal bonding performance adhesives to obtained through the contrast.Experimental data showed that in the preparation of waterborne polyurethane emulsions containing carboxylic acid groups and zirconium salt,when the R value was 1.15,DMBA was 6.02%(mass fraction of the total reaction monomer,similarly hereinafter),TMP was 1.99%,KH-550 was 0.74%,AZC was 0.76%,neutralization degree of 100% and adopt the method of after neutralization to reaction that will be the optimal performance.Set the content of AZC is 0.06 times of the carboxyl content,and the other parameters are the same as described above,effect of DMBA and sulfonate type chain extension agent diamine sulfonate(PPS),3-chloro-2 hydroxy propyl sulfonic acid sodium(CHPS),1,4-dihydroxybutane-2-sodium sulfonate(DDBS),aliphtic diamine sulphonate(AAS)different proportion on properties of waterborne polyurethane were investigated,respectively.The results showed that when the DMBA and PPS ratio of 7∶3,DMBA and CHPS ratio of 9∶1,DMBA and DDBS ratio of 9∶1,DMBA and AAS ratio of 7∶3,in the same series of the optimal performance.Lastly,two different types two-component of waterborne polyurethane adhesives for rubber-leather and leather-leather thesizing process were studied,respectively.Results showed that in the rubberleather and leather-leather adhesive strength test,carboxylic acid/sulfonic acid type containing zirconium salt waterborne polyurethane adhesives showed excellent bonding performance.For rubber-leather peel strength,the carboxylic acid/sulfonic acid type containing zirconium salt waterborne polyurethane adhesives compared to carboxylic acid type containing zirconium salt waterborne polyurethane adhesives higher(≥0.98N/cm)and at the same time for leather-leather peel strength,the carboxylic acid/sulfonic acid type containing zirconium salt waterborne polyurethane adhesives compared to carboxylic acid type containing zirconium salt waterborne polyurethane adhesives higher(≥0.67N/cm).