Water absorbent resins
US4954562A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 30, 1989 |
| Grant date | Sep 4, 1990 |
| Priority date | — |
| Expiry date | Jan 30, 2009 |
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); (C) styrene, in an amount of 0% to 25% based on the weight of acrylic acid or acrylate; and (D) a water miscible or a water soluble polyvinyl monomer in the presence of (E) a metal oxide, such as titanium dioxide, in an amount of 0.001% to 5% based on the total weight of (A), (B), (C), (D) and (E), such that the amount of (D) is 0.001 to 0.6 weight percent based on the total weight of (A), (B), (C), (D) and (E). 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 metal oxide-containing 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.