Copolymer blend compositions for use to increase paper filler content
US8163134B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Sep 18, 2009 |
| Grant date | Apr 24, 2012 |
| Priority date | — |
| Expiry date | Jul 30, 2030 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08L33/26
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
Methods for making a heterogeneous polymer blend comprising one or more anionic polymers, one or more cationic polymers, and one or more non-ionic polymers, which method comprises (a) adding to a non-neutral solution a first amount of polymerization initiator and one or more anionic or cationic monomers, wherein each monomer has the same charge; (b) adding a second amount of the polymerization initiator and one or more non-ionic monomers; (c) adding a third amount of the polymerization initiator and one or more ionic monomers that are oppositely charged from the monomers of (a); adding stepwise, a fourth amount of the polymerization initiator to react any residual monomer, and (e) neutralizing the resulting polymer blend. Also claimed are heterogeneous polymer blends containing polymers formed from one or more anionic, cationic, and non-ionic monomers, either polymerized in situ or separately and then combined. Also claimed are methods for increasing the filler content of paper or paperboard, which methods comprises (a) combining the heterogeneous polymer blend with a precipitated calcium carbonate filler; (b) combining the resulting mixture with a pulp slurry; and (c) processing t…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.