MICROPARTICLES OF COPOLYMER CONTAINING VINYLAMINE AS ADDITIVES IN PAPERMAKING Russian patent published in 2017 - IPC C08F226/02 C08F212/08 D21H17/35 D21H17/55 

FIELD: textile, paper.

SUBSTANCE: additive producing method is that the reaction vinylformamide with styrene or substituted styrene is carried out under the conditions of free radical emulsion polymerization. The first polymeric product is obtained, it comprises randomly distributed repeating units of formula (I) and (II), in which Ar is an aromatic moiety selected from the group consisting of phenyl and phenyl substituted by alkyl; R1 is hydrogen or alkyl; x and y are numbers that are greater than 0 moll. %, and the sum of x and y is 100 moll. %, the x:y ratio ranges from 99:1 to 50:50. Further hydrolysis of the first polymeric product is carried out by treatment with an acid or base. The second polymer product is obtained, it represents a terpolymer comprising randomly distributed repeating monomer units described by at least two formulas (III), (IV), (V) and (VI), wherein R₂ and R₃ are H; R₄ is H or alkyl; m₁ and m₂ independently stand for a positive number of moll. %, and m₃ and m₄ independently can be from 0 to 99 moll. %, and the sum of m₁, m₂, m₃ and m₄ is equal or less than the x moll. % of the formula (I). The first polymeric product is in the form of microparticles which have size in the range from 50 to 200 nm. The second polymeric product is in the form of microparticles in an aqueous dispersion, and its viscosity measured at ambient temperature of 20 to 25°C at a content of active solids, lying in the range from 13.0 to 18.0%, is in the range of 100 to 500 cps. A paper product comprises an additive of vinyl amine - vinyl formamide terpolymer.

EFFECT: increased paper strength in wet and dry conditions.

18 cl, 5 tbl, 5 ex