Synthesis And Properties Of Polyacrylate Emulsion By Macromolecular Emulsifier

For the past few years,with the rapid economic and social development and in the background of "green mountains and green mountains are Jinshan Yinshan",people are paying more and more attention to environmental protection while pursuing economic development.High energy consumption,high pollution and high Emissions companies will find it increasingly difficult to survive.The printing industry has been greatly impacted by excessive VOCs emissions,so it is necessary to make targeted changes.Flexographic printing water-based inks will soon become the main products in the next-generation printing ink industry due to the almost no emission of VOCs.However,there are currently not many products for flexographic printing water-based inks on the domestic market,and most of the water-based inks use acrylic emulsions prepared by small molecule emulsifiers.It has poor printing adaptability,poor resolubility,gloss and adhesion on plastic substrates,and has a large gap with solvent-based inks,which seriously restricts the large-scale popularization and application of water-based inks.In this paper,a macromolecular emulsifier is used to replace the conventional small molecule emulsifier,and a polyacrylate emulsion with small particle size,narrow distribution,high solidity,low viscosity and good stability can be synthesized.The prepared flexographic printing ink has a fast drying speed.It has high gloss,good transferability and adaptability,and has good adhesion on various plastic film substrates.The invention solves the problems of poor resolubility of the product and poor printing transferability.The main work of the paper is as follows:1.Using a variety of macromolecular emulsifiers to synthesize polyacrylate emulsion,systematically studied the influence of polymerization process,reaction monomer and solid content on the performance of emulsion.The experimental results show that a macromolecular emulsifier with a molecular weight of 7000-10000 and an acid value of about l80-250 can be prepared by a conventional semi-continuous seed emulsion polymerization process at a reaction temperature of 80-8.5℃.A poly aery late emulsion having a solid content of 50%,a rotational viscosity of 220 mPa.s,a particle diameter of 93 nm,and it has good stability than other product,and has excellent adhesion on plastic substrates such as PE,PP,and PET.It can meet the basic performance requirements of water-based ink for flexographic printing.2.In cooperation with the user,the ink formulation research and the actual running printing performance test of the ink were carried out.According to the problems of the emulsion fineness,the water resistance still need to be improved,and the residual monomer concentration are high,the targeted research is further carried out.It was found that the fineness of the emulsion can be reduced from 50μm to less than 10 μm by controlling the process conditions such as the amount of input of the seed,the dropping time of the monomer,and the stirring speed;By using 3 parts of diacetone acrylamide(DAAM)The ratio of diacid dihydrazide(ADH)is controlled at DAAM:ADH=5:2,and the use of ammonia(4 parts)/NaOH(4 parts)/amp-95(2 parts)composite neutralizer system,It can effectively improve the water resistance without reducing the resolubility of ink,and greatly reduce the pungent smell of ammonia in the emulsion;controlling the pH of the emulsion to be 7 can be carried out without affecting the initial drying speed.The thoroughly drying speed is increased by 30%,which satisfies the performance requirements of the ideal dry-set ink for slow initial drying speed and fast thoroughly drying speed;the post-redox elimination system using 0.3%t-butyl hydroperoxide and 0.15%FF6 is more effective in eliminating residual monomers in the product.3.The 20L and 500L scale emulsion polymerization pilot scale production process research was completed,which laid the foundation for future industrial production.