Aqueous polymer composition for paper coating

摘要

The present invention concerns aqueous polymer compositions comprising a water soluble hydrophilic polymer with poly(ethylene oxide) content higher than 50% by weight and a polyacrylic thickener containing sulfonic groups. The aqueous polymer compositions of the invention are useful as deflocculants, rheology modifiers and water retention agents for paper coating compositions.

主权项

1. An aqueous polymer composition comprising:
A) a water soluble hydrophilic polymer with a poly(ethylene oxide) content higher than about 50% by weight; and B) a polyacrylic thickener obtained by polymerization of:
a) from about 0.1 to about 20% by weight of a monoethylenically unsaturated monomer containing a sulfonic acid group or a salt thereof;b) from about 20 to about 70% by weight of a (meth)acrylic acid ester;c) from about 20 to about 50% by weight of a monoethylenically unsaturated monomer containing one or more carboxylic groups;d) from about 0 to about 3% by weight of a polyethylenically unsaturated monomer; ande) from about 0 to about 15% by weight of a nonionic acrylic associative monomer, wherein:
a weight ratio between the water soluble hydrophilic polymer and the polyacrylic thickener is from about 60/40 to about 90/10; anda sum of the percentages of A) and B) is from about 10 to about 40% by weight of the composition itself.