Solutions of acrylamidoalkanesulfonic acid salts in organic liquids and method for their preparation
US4176081A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 15, 1978 |
| Grant date | Nov 27, 1979 |
| Priority date | — |
| Expiry date | Feb 15, 1998 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08F20/54
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
Solutions of salts, especially sodium salts, of acrylamidoalkanesulfonic acids in organic liquids such as dimethylformamide are prepared by reacting the acid with a metal salt of a weak acid (preferably a metal carbonate or bicarbonate), or a cation exchange resin in the metal salt form, in the organic liquid in the presence of a free radical polymerization inhibitor (preferably an oxygen-containing gas such as air with which the mixture is blown) until the neutralization number of the mixture to phenolphthalein is a base number or, if an acid number, is no higher than about 1.0. In a preferred embodiment of the process, the mixture is blown with air and such blowing is continued until the acid number of the system is no greater than about 1.0, after which a strongly alkaline reagent is added until the neutralization number is a base number or an acid number no higher than about 0.1.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.