Process for producing water-absorbing resins
US5380808A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 11, 1991 |
| Grant date | Jan 10, 1995 |
| Priority date | — |
| Expiry date | Jul 11, 2011 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08F222/385
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
The invention concerns a process for producing water-insoluble water-absorbing resins, which comprises the steps of initiating polymerization of an aqueous solution containing 30 to 80% by weight of (a) a hydrophilic vinyl monomer having a functional group and (b) a crosslinking agent by supplying the aqueous solution together with (c) a polymerization initiator to a polymerizing apparatus capable of heating and/or cooling surfaces in contact with the aqueous solution, subsequently causing constant temperature polymerization of the solution without agitating the same by controlling the temperature of the system being polymerized to 20.degree. to 70.degree. C., and elevating, if necessary, the temperature ok the system to be in excess of 70.degree. C. in a stage with a polymerization percentage of 70% or above before completion of polymerization. Obtainable water-insoluble water-absorbing resins have excellent water-absorbing property and have less water-soluble components. Thus, the water-absorbing resins according to the invention are useful for physiological commodities, paper diapers or like sanitary materials, drip absorbing materials, cold water retainers, dew condensation pre…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.