Disperant system for making polyvinyl chloride which produces low color chlorinated polyvinyl chloride
US6277922A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 15, 1990 |
| Grant date | Aug 21, 2001 |
| Priority date | — |
| Expiry date | Oct 15, 2010 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08F8/22
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
Chlorinated polyvinyl chloride (CPVC) is prepared from polyvinyl chloride (PVC). When PVC is made utilizing polyvinyl alcohol, the low molecular weight CPVC compound so prepared is colored. A low molecular weight CPVC compound prepared from PVC that was made in the presence of a cellulose ether instead of polyvinyl alcohol resulted in a very low color compound having a DE of O by definition. However, a CPVC compound prepared from PVC made in the presence of polyvinyl alcohol resulted in a relatively high color (DE 18.51). During the polymerization of vinyl chloride, polyvinyl alcohol is replaced with the hydroxypropylmethyl cellulose ether having a methoxyl substitution of 15-35 percent and a hydroxypropoxyl substitution of from 4-35 percent.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.