Flameproofing agents
US4311855A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 25, 1980 |
| Grant date | Jan 19, 1982 |
| Priority date | — |
| Expiry date | Jan 25, 2000 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD06M15/431
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
An improved process for manufacturing tetrakis (hydroxymethyl) phosphonium amide condensation product without the formation of a precipitate. Urea or thiourea is added to the tetrakis (hydroxymethyl) phosphonium salt having an anion formed from a dibasic or tribasic or polybasic acid. The said salt is in aqueous solution. The pH of the aqueous solution of said salt is adjusted to the range of 4-6.5 when the urea or thiourea is added to the salt. The proportion of said salt to said urea or thiourea is 1:0.05-0.5 (molar). The sulphuric acid salt is preferred. The process produces an improved aqueous product substantially free of insolubles.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.