| abstract |
Hydrophobically modified polysaccharide and synthetic polymers with molecular weights of 10,000 to 300,000 serve as associative thickeners in aqueous protective coatings to (-NORTH-)eveling without adversely affecting sag or thickening efficiency. Hydrophobically modified hydroxyethylcellulose, hydroxyethylstarch, hydroxypropylguar, etc. can be degraded with hydrogen peroxide to lower the molecular weight to the desired level. A preferred polysaccharide is hydrophobically modified hydroxyethylcellulose with a weight percent hydrophobe substitution of 0.2 to 2Ø A preferred synthetic polymer is hydrophobically modified poly{vinyl alcohol) with a molecular weight of 10,000 to 50,000. |