(Meth)acrylic acid/itaconic acid copolymers, their preparation and use as antiscalants
US5032646A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 28, 1984 |
| Grant date | Jul 16, 1991 |
| Priority date | — |
| Expiry date | Sep 28, 2004 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC02F5/10
- WIPO fieldEnvironmental technology
- WIPO sectorChemistry
Abstract
Substantially homogeneous (meth)acrylic acid/itaconic acid copolymers of number average molecular weight of 500 to 7000 are prepared by copolymerizing in aqueous solution 5 to 90 mole percent acrylic or methacrylic acid monomer with 95 to 10 mole percent itaconic acid monomer at 80.degree. to 120.degree. C. in the presence of a polymerization initiator, the acrylic or methacrylic acid monomer and at least half of the initiator being added separately and continuously to the itaconic acid monomer throughout the polymerization period. The copolymers are employed at a level of from about 0.1 to 100 ppm for prevention of alkaline calcium and magnesium scale formation, such as during seawater evaporative desalination.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.