Vinyl ester copolymer dispersions, their preparation and use

摘要

A description is given of an aqueous vinyl ester copolymer dispersion stabilized with a combination of at least one protective colloid and of at least one emulsifier, said dispersion having a viscosity of less than 8000 mPa*s, a weight average dw of the particle sizes of 0.5 to 10 μm, and a ratio of weight average to number average of the particle sizes, dw/dn, of at least 2.5, and the polymer possessing a glass transition temperature of between −30 and +15° C.;The dispersion can be used as an adhesive for nozzle application processes.

主权项

1. An aqueous vinyl ester copolymer dispersion stabilized with at least two polyvinyl alcohols having different molecular weights combined with from 0.05% to 5% by weight, based on the total amount of monomers employed, of at least one emulsifier, said dispersion having a viscosity of less than 8000 mPa*s, a weight average dw of the particle sizes of 0.5 to 10 and a ratio of weight average to number average of the particle sizes, dw/dn, in the range of from 2.5 to 20.0, wherein said copolymer possesses a glass transition temperature of from −20 to +5° C., wherein said at least one emulsifier is selected from the group consisting of ethoxylated, non-ionic emulsifiers, ethoxylated, anionic emulsifiers, or combinations thereof and wherein an aqueous solution of at least one of said at least two polyvinyl alcohols possesses a viscosity at 20° C. of from 18 to 60 mPa*s and an aqueous solution of at least one of said at least two polyvinyl alcohols possesses a viscosity at 20° C. of from 2 to 18 mPa*s.