Effect Of Double Reactive Emulsifier System On Acrylic Emulsion And Its Ink Properties

With increasingly stringent environmental regulations in the world,it is a trend to develop water-based environment-friendly products in high pollution industries such as coatings and inks.Polyacrylate latex is one of the most widely used film forming resins（or adhesives）in water-based products because of its good color retention,good light retention and low cost.Polyacrylate emulsions are usually synthesized with traditional non-reactive small molecule emulsifiers.Emulsifier plays an important role in emulsion polymerization and the improvement of latex properties.Small molecule emulsifiers exist on the surface of emulsion particles in the form of physical adsorption,and are desorbed from the surface during the storage process of emulsion,resulting in low resistance and stability of calcium ions,thus affecting the stability of coatings,ink and other products and other practical performance.In addition,the small molecule emulsifier is easy to migrate to the surface of the emulsion film in the process of emulsion film forming,resulting in slow film forming speed,poor water resistance,poor adhesion and many other problems.In addition,emulsion in ethanol environment,emulsifier is easy to be dissolved by ethanol,resulting in emulsion particles coalescence,resulting in latex flocculation or demulsification.In this thesis,in order to improve the ethanol resistant stability of acrylic emulsion and of its corresponding water-based ink,the matching of emulsion and color paste,and the adhesion on non-polar plastic substrates such as PE and PP,this thesis aims to study the effect of anion/non-ionic reactive emulsifier compounding system on the ethanol-resistant stability of emulsion and the performance of the prepared water-based ink（adhesion on non-polar plastic substrates such as BOPP and PE,drying speed of inks,matching of emulsion and color paste）,etc.,At the same time,the effect of metal ion crosslinking agent on the stability of ethanol-resistant stability of emulsion and on the crosslinking density of the emulsion film formation were also studied.The main work of this thesis is as follows.1)The effects of reactive nonionic emulsifiers on the performance of acrylic core-shell emulsions were investigated with reactive anionic/nonionic emulsifier compounding systems.It was found that reactive nonionic emulsifiers could effectively improve the calcium ion stability of the latexes relative to traditional nonionic small molecule emulsifiers.Among them,the higher the amount of reactive nonionic emulsifier,the better the calcium ion stabilization,but the use of too much nonionic emulsifier can significantly increase the particle size of the emulsion and the gel volume of the polymerization reaction.For several emulsification systems studied here,when the mass ratio of reactive anionic emulsifier and reactive nonionic emulsifier was 1.5:1,the prepared latexes have small particle size and low latex gelation rate,the latex Ca Cl₂ resistance stability was increased from 5%of the reference sample to 25%,water absorption of the latex film was reduced from 10.6%to 7.76%,the ethanol resistance stability reached 30%.The compatibility of the latex with various commercially available color pastes was significantly improved.The adhesion of the formulated ink on plastic substrates BOPP and PE is excellent,with the adhesion of yellow ink on BOPP film increasing from 92%to 99%and blue ink from 93%to 99%;the adhesion of yellow ink on PE film increasing from 99%to 100%and blue ink from 99%to 100%.2)SR-10 was used as the anionic emulsifier and compounded with reactive nonionic emulsifier A,B,C and D,respectively,to study the effects of their ratios and dosages on the polymerization reaction and latex properties.It was found that among the above emulsifier systems,when the mass ratio of anionic/nonionic emulsifier was 1.5:1,the prepared latexes have smaller particle size and the lowest gelation rate.Compared with the control latex,the latexes were all improved in ethanol resistance stability,and the adhesion of the ink on the plastic substrates BOPP and PE films was significantly improved,while the crosslinking density of the emulsion films was large.The spatial site resistance provided by reactive nonionic emulsifiers can effectively improve the ethanol resistance stability of the emulsions.When the reactive nonionic emulsifier B and reactive anionic emulsifier SR-10 compound,the best ethanol resistance stability of the latex can be achieved.3)The performance of the water-based ink prepared using the homemade latex was compared with that of the ink formulated by the commercially available emulsion Neo Cryl A-1091,and it was found that the ink prepared by the homemade latex has better or comparable performance in terms of adhesion on plastic substrates,wet friction resistance of the printed products,and resistance to dioxygen than the commercially available samples.The fastness to hydrogen peroxide of the X-10/Y-10 system exceeded 100 times,while the ink film made by the commercially available emulsion Neo Cryl A-1091 was only 62 times;in the wet friction resistance test,the wet friction resistance of the SR-10/A system and the X-10/Y-10 system both exceeded100 times,while the commercially available emulsion Neo Cryl A-1091 The sample made by Neo Cryl A-1091 was only 62 times.4)The effect of the addition of zinc oxide metal ion cross-linking agent on the ethanol resistance stability of the latex and its ink performance was investigated.It was found that the Pickering emulsion formed using zinc oxide when using a metal ion with a ketone hydrazine double cross-linking system resulted in a significant improvement in the ethanol resistance stability of the emulsion,thereby increasing the ethanol resistance stability of its corresponding aqueous ink to over 40%.