Patent US2312761A successfully refreshed from Google Patents.
US4501871A
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Process for the production of anhydride-group- or carboxyl-group-containing graft copolymers of polysaccharide esters
Assignee: Bayer AG
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Filing: 1983-12-20
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Granted: 1985-02-26
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Expires: 2003-12-20
Abstract
Abstract Anhydride-group- or carboxyl-group-containing graft copolymers of vinyl esters and other suitable monomers on polysaccharide esters of (A) a polysaccharide ester of aliphatic C 1 -C 5 -mono-carboxylic acids as the graft substrate and (B) a grafted-on monomer mixture of (a) a vinyl ester of a C 1 -C 18 -monocarboxylic acid and (b) maleic acid anhydride and/or semiesters of maleic acid and/or fumaric acid with aliphatic C 1 -C 14 -monoalcohols, the ratio by weight of (A) to (B) being from 1:0.1 to 1:2 and the molar ratio of (a) to (b) being from 1:0.5 to 1:3, and a process for producing these graft copolymers.
Inventors
- 👤 Herbert Bartl
- 👤 Heinrich Alberts
- 👤 Klaus Schuster
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 21:59
CPC Classifications
C; C08; C08F; C08F251/00
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
116 words
A process for producing a graft copolymer which comprises radically polymerizing in homogeneous solution 0.1 to 2 parts by weight of a monomer mixture of (a) 1 mole of a vinyl ester of a C 1 -C 18 -monocarboxylic acid and (b) from 0.5 to 3 moles of maleic acid anhydride and/or a semiester of maleic acid and/or fumaric acid with aliphatic C 1 -C 24 -monoalcohols in the presence of one part by weight of a polysaccharide ester of an aliphatic C 1 -C 5 -monocarboxylic acid and in the presence of a catalytic amount of a radical initiator selected from the group consisting of organic peroxides, peroxydicarbonates, readily decomposable azo compounds and short-wave radiation.
Claim 2
Dependent Claim
116 words
A process for producing a graft copolymer which comprises radically polymerizing in homogeneous solution 0.1 to 2 parts by weight of a monomer mixture of (a) 1 mole of a vinyl ester of a C 1 -C 18 -monocarboxylic acid and (b) from 0.5 to 3 moles of maleic acid anhydride and/or a semiester of maleic acid and/or fumaric acid with aliphatic C 1 -C 24 -monoalcohols in the presence of one part by weight of a polysaccharide ester of an aliphatic C 1 -C 5 -monocarboxylic acid and in the presence of a catalytic amount of a radical initiator selected from the group consisting of organic peroxides, peroxydicarbonates, readily decomposable azo compounds and short-wave radiation.
Claim 3
Dependent Claim
30 words
The process of claim 1 wherein the solvent for said homogeneous solution is at least one member selected from the group consisting of tert.-butanol, methylene chloride and glacial acetic acid.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-02-26 | 1988-08-27 | 1989-02-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-02-26 | 1992-08-27 | 1993-02-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-02-26 | 1996-08-27 | 1997-02-26 | $7700.00 | Window Closed / Lapsed |