Claims
- 1. A method of lowering the viscosity of an aqueous dispersion of fine particle size calcium carbonate 20 to 30% solids, having a mean surface area of at least 60 m2/g for use in a paper coating composition comprising adding to said aqueous dispersion poly(vinyl alcohol) in an amount of from 0.1 to 50 parts by weight poly(vinyl alcohol) per 100 parts calcium carbonate, the poly(vinyl alcohol) having a degree of polymerization of 150 to 300 and beinig 87 to 89 mole % hydrolyzed, and the poly(vinyl alcohol) particles having an average particle size of 180 μm or less.
- 2. The method of claim 1 wherein poly(vinyl alcohol) is added in an amount of from 3 to 25 parts poly(vinyl alcohol)/100 parts calcium carbonate.
- 3. The method of claim 1 wherein poly(vinyl alcohol) is added in an amount of from 5 to 15 parts poly(vinyl alcohol/100 parts calcium carbonate.
Parent Case Info
This application is a division of application Ser. No. 09/435,177, filed Nov. 5, 1999.
US Referenced Citations (2)
Number |
Name |
Date |
Kind |
5057570 |
Miller et al. |
Oct 1991 |
A |
5643631 |
Donigian et al. |
Jul 1997 |
A |