Corrosion inhibitor
US5017306A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 9, 1988 |
| Grant date | May 21, 1991 |
| Priority date | — |
| Expiry date | Nov 9, 2008 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07F9/3808
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A method of preparing phosphonate compositions comprising di-(phosphonomethyl) formal is disclosed which comprises (a) forming an intimate mixture of hydroxymethylphosphonic acid and formaldehyde or its condensates, said mixture having a least about 0.5 equivalents of formaldehyde per equivalent of hydroxymethylphosphonic acid; and (b) subjecting said intimate mixture to a temperature of between about 100.degree. C. and 180.degree. C. for a time sufficient to allow the components to react to form a reacted mixture comprising di-(phosphonomethyl) formal. Di-(phosphonomethyl) formal, phosphonate compositions wherein at least about 20 more % of the phosphonate groups are present as di-(phosphonomethyl) formal, and phosphonate compositions which comprise hydroxymethylphosphonic acid and di-(phosphonomethyl) formal such that the mole ratio of phosphonate groups present as di-(phosphonomethyl) formal to phosphonate groups present as hydroxymethylphosphonate is at least about 1:3, as disclosed, may be used for corrosion inhibition in aqueous systems.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.