This method is a preparation method of a cationic polymer emulsifier for AKD. According to the physical and chemical properties of the bonding components, suitable vinyl monomers such as long-chain acrylic acid esters and cationic monomers are selected, and in the presence of modified polyvinyl alcohol , Using the seed polymerization method to carry out free radical soap-free emulsion copolymerization in aqueous solution, the cationic polymer emulsifier for AKD can be obtained. The invention can replace the small molecular emulsifier added in the traditional AKD emulsion, solve the problems of easy foaming, poor stability and sizing effect of the emulsion, and at the same time, its retention performance and anti-anionic garbage interference performance are greatly improved, not only can improve the paper Waterproof performance can also improve the physical strength of the paper; and there is no need to add cationic starch as a colloid protective agent during the preparation of the emulsion, which avoids the defect that the AKD emulsion is easily deteriorated during high temperature and long-term storage, resulting in poor sizing effect and stability of the AKD emulsion.
Preparation method of cationic polymer emulsifier for AKD
The preparation method of cationic polymer emulsifier for AKD is characterized by:
1) adding polyvinyl alcohol and deionized water in a mass ratio of 1-3:10 into a drying reactor, heating to 80-100°C, and keeping the temperature for 1- After 3 hours to completely dissolve the polyvinyl alcohol in the reactor, cool down to room temperature to obtain a polyvinyl alcohol aqueous solution A, or mix the solution A and the cationic etherifying agent uniformly at a mass ratio of 100:1-40, and adjust with alkali. The pH value of the system reaches 8-10, and the cation-modified polyvinyl alcohol solution B is prepared by reacting at 50-70 °C for 1-3 hours;
2) Mix the hard oil-soluble vinyl monomer, soft oil-soluble vinyl monomer, cationic Monomers and hydrophilic vinyl monomers are mixed in a mass ratio of 1:0.2-10:0.1-0.5:0.1-0.3, hard oil-soluble vinyl monomers and soft vinyl monomers Mix oil-soluble vinyl monomers to obtain solution C, and mix cationic monomers and hydrophilic vinyl monomers to obtain solution D;
3) Mix deionized water and water-soluble initiator in a mass ratio of 1:0.002-1
4) Take less than half of solution C, solution D and initiator aqueous solution E and add dropwise to solution A or solution B, and react at 60-85°C for 0.5-2h to obtain cationic soap-free solution Styrene-acrylic polymer seed emulsion F, the remaining solutions C, D and initiator aqueous solution E were added dropwise to the seed emulsion F within 1-4 h, and the cationic polymer emulsifier for AKD was obtained by continuing to keep the temperature for 2-4 h after the dropwise addition. Wherein, the mass ratio of pure polyvinyl alcohol in solution A or solution B: solution C: solution D: water-soluble initiator in the initiator aqueous solution E is 1:3-10:5-10:0.2-1
