Water absorbent resins prepared by polymerization in the presence of styrene-maleic anhydride copolymers
US4820773A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 25, 1987 |
| Grant date | Apr 11, 1989 |
| Priority date | — |
| Expiry date | Jun 25, 2007 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08F2810/20
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
Improved water-absorbing, crosslinked acrylate resins are prepared by aqueous polymerization of (A) acrylic acid neutralized 70 to 100 mole percent for example with ammonia and/or caustic alkali and/or an amine; with (B) acrylamide in a mole ratio of 70 to 100 mole percent (A) to 30:0 mole percent (B); and (C) a water miscible or a water soluble polyvinyl monomer in the presence of (D) a styrene-maleic anhydride copolymer, neutralized 70 to 100 mole percent for example with ammonia, and/or caustic alkali and/or an amine, in an amount of 1% to 25% based on the weight of acrylic acid or acrylate, such that the amount of (C) is 0.001 to 0.6 weight percent based on the total weight of (A), (B), (C) and (D). In addition, surface treating the water-absorbing crosslinked acrylate resins with a polyquaternary amine substantially further increases both the rate of water absorption and the quantity of water absorbed and retained by the resin. The untreated and the surface-treated resins also maintain the necessary "dry feel" required for most applications.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.