Solid homogenous mixtures of polyvinylacetate and vinylacetate-vinyl laurate copolymer prepared by sequential solution polymerization
View Patent ↗The invention provides homogeneous compositions in solid form comprising a) from 50 to 90% by weight of polyvinyl acetate and b) from 10 to 50% by weight of vinyl acetate-vinyl laurate copolymer, the weight percentages based on the total weight of the composition.
1. A process for producing a homogeneous composition, comprising solution polymerizing comonomers including vinyl acetate and vinyl laurate in a targeted quantitative ratio to form a vinyl acetate-vinyl laurate copolymer b), following which vinyl acetate monomer is added and polymerized after a monomer conversion of from 60 to 100% by weight of the comonomers used to form copolymer b), and isolating the product as a solid,
wherein the homogenous composition is in solid form, and comprises
from 50-90% by weight, based on the total weight of the homogenous composition, of a) a polyvinyl acetate polymer containing more than 90% by weight of vinyl acetate derived moieties based on the weight of the polyvinyl acetate polymer, and
from 10 to 50% by weight based on the total weight of the homogenous composition, of b) as vinyl acetate-vinyl laurate copolymer containing 10-50% of vinyl laurate derived moieties based on the weight of the vinyl acetate-vinyl laurate copolymer.
2. The process of claim 1 wherein the polyvinyl acetate polymer a) is present in an amount of from 60-80% by weight based on the weight of the homogenous composition and the vinyl acetate-vinyl laurate copolymer b) is present in an amount of 40-20% by weight based on the total weight of the homogenous composition.
3. The process of claim 1 wherein the weight-average molecular weight Mw of the polyvinyl acetate polymer a) is from 10,000 to 100,000 and the weight-average molecular weight Mw of the vinyl acetate-vinyl laurate copolymer b) is from 100,000 to 600,000.
4. The process of claim 1 wherein the vinyl acetate-vinyl laurate copolymer contains 60-80% of vinyl acetate derived moieties and 20-40% of vinyl laurate-derived moieties based on the weight of the vinyl acetate-vinyl laurate copolymer.