Preparation And Characterization Of High Solid Low Chlorine Coating Versus Aqueous Polyamide Polyurea Epichlorohydrin Resin

The urea modified polyaminamide epihalohydrin resin(PAPU) is a late-model environmental-protecting water-resistance agent without free formaldehyde.It has excellent application value in paper making. Although it has quite a few merits in paper making industry,including high whiteness,solidified in neutral environment and high filler retention rate,it has several shortcomings,such as low solid-content and contenting organochlorine and so an.With the sanitation standard is more and more strict,the concentration of organochlorine has to be reduced.At abroad a few articles and patents were presented,but most methods which introduced belong to aftertreating ones.Besides increasing new equipments expense,the methods would reduce production and demand strict technology parameters.PAPU was prepared by three step reactions and adipic acid, diethylenetriamine,epichlorohydrin and urea as materials.Based on the low solid-content,this study was designed to add auxiliary in the amidation reaction to improve the solid-content of product and it showed that the solid-content of product increased from 60%to 72%,but the apparent viscosity had no changes.The influence of reaction temperature, reaction time and material ratio on the solid-content and apparent viscosity of product was also studied and the optimum reaction conditions were obtained.The optimum reaction conditions were as follows:the molar ratio of adipic acid to diethylenetriamine was 1:1,reaction temperature was 190～200℃and reaction time was 150min in the amidation reaction;the quantity of urea was 12g,reaction temperature was 125℃and reaction time was 10h in the deamination reaction;the quantity of epichlorohydrin was 7g,reaction temperature was 70～80℃and reaction time was 70min in the crosslinking reaction;water was twelve times of adipic acid.The solid-content of product was 72%and the apparent viscosity was 765 mPa.s in the optimum reaction conditions.Based on the organachlorine in the product,the analytical method was built in this paper.The cause of producing organochlorine was analyzed in theory,so as to produce less organochlorine in the new process.So the crosslinking reaction was at low temperature,as a result the amount of organochlorine was reduced heavily reaching sanitary standard without aftertreating.Factors affecting organochlorine content and advisable conditions were found through orthogonal experiment.The organochlorine content was less than 0.1%in the product which was treated by ethanolamine after the crosslinking reaction.