Process for production of an ethanol solution of the ethyl or butyl half-ester of a copolymer of maleic anhydride and methyl vinyl ether
US5223567A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 16, 1992 |
| Grant date | Jun 29, 1993 |
| Priority date | — |
| Expiry date | Mar 16, 2012 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08F8/14
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
There is described a process for the production of an ethanol solution of an ethyl or butyl half-ester copolymer of maleic anhydride and a methyl vinyl ether which comprises: (a) copolymerizing the monomers in acetone as solvent by simultaneously feeding molten maleic anhydride, a molar excess of methyl vinyl ether, and a solution of a free radical initiator in acetone, into a reactor precharged with acetone, at about 68.degree.-85.degree. C., preferably 70.degree.-80.degree. C.; (b) esterifying the acetone solution of said copolymer with ethanol or butanol; and then (c) solvent exchanging ethanol for acetone by continuously injecting vapors of ethanol at about 85.degree.-95.degree. C. into said copolymer solution while simultaneously distilling out acetone therefrom at atmospheric pressure.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.