Solvent system and method for removing polymer scale from vinyl polymer polymerization reactors
US5782989A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 19, 1997 |
| Grant date | Jul 21, 1998 |
| Priority date | — |
| Expiry date | Nov 19, 2017 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC11D2111/20
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
Polymer scale removal from vinyl polymerization reactors is effected without the use of polar aprotic solvents or aromatic solvents, by adding to the reactor, a scale removal composition comprising acetone, a most minor amount of a strong base, and a minor amount of a hydroxyl- or amino-functional polar organic solvent. The composition may contain surfactants, chelating or sequestering agents, detergent builders, and the like, and water in amounts of up to about 3 weight percent. Scale removal is efficient and rapid when the scale removing composition is agitated in the reactor at temperatures ranging from about 50.degree. C. to 120.degree. C.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.