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US3997706A
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Process for the chloromethylation of styrene-divinylbenzene copolymers
Assignee: Dow Italia SRL
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Filing: 1974-11-27
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Granted: 1976-12-14
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Expires: 1994-11-27
Abstract
Abstract There is disclosed a process for chloromethylating styrene-divinylbenzene copolymers by treating the copolymers with methylal and thionyl chloride in a molar ratio not exceeding 2:1 and in the presence of a catalyst of the Friedel-Crafts type or which consists of an acid. As is known, the chloromethylation of cross-linked aromatic polymers of the styrene-divinylbenzene type is an important stage in the preparation of anionic exchange resins.
Inventors
- 👤 Lucio Galeazzi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 14:49
CPC Classifications
C; C08; C08F; C08F8/00; C08F8/18; C08F8/24
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
76 words
A process for the chloromethylation of styrene-divinylbenzene copolymers by using a methylating agent, a chlorine donor and a catalyst, characterized in that the copolymer to be chloromethylated is treated in either the presence or absence of swelling agents, and of inert dispersants, with a mixture of methylal and thionyl chloride in the presence of a Friedel-Crafts type catalyst or of a catalyst consisting of an acid, the methylal/thionyl chloride ratio being comprised between 0.5:1 and 2:1.
Claim 2
Dependent Claim
76 words
A process for the chloromethylation of styrene-divinylbenzene copolymers by using a methylating agent, a chlorine donor and a catalyst, characterized in that the copolymer to be chloromethylated is treated in either the presence or absence of swelling agents, and of inert dispersants, with a mixture of methylal and thionyl chloride in the presence of a Friedel-Crafts type catalyst or of a catalyst consisting of an acid, the methylal/thionyl chloride ratio being comprised between 0.5:1 and 2:1.
Claim 3
Dependent Claim
17 words
The process according to claim 1, characterized in that the catalyst is stannic chloride or zinc chloride.
Claim 4
Dependent Claim
14 words
The process according to claim 1, characterized in that the catalyst is chlorosulphonic 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) | 1979-12-14 | 1980-06-14 | 1980-12-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-12-14 | 1984-06-14 | 1984-12-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-12-14 | 1988-06-14 | 1988-12-14 | $7700.00 | Window Closed / Lapsed |