Patent US3755234A successfully refreshed from Google Patents.
US3755234A
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Process for preparing graft copolymer emulsions
Assignee: DIACEL Ltd
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Filing: 1971-07-27
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Granted: 1973-08-28
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Expires: 1991-07-27
Abstract
Abstract Vinyl monomers are graft-copolymerized with the aid of a tetravalent cerium salt as a polymerization initiator in an aqueous polyvinyl alcohol solution. Aqueous emulsions of graft copolymers of high concentration are prepared, which emulsions have a high film-forming property and a smooth consistency, but are free of any lumps.
Inventors
- 👤 K Chujo
- 👤 S Tokuhara
- 👤 S Watanabe
- 👤 K Tanaka
- 👤 Z Honda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 14:26
CPC Classifications
C; C08; C08F; C08F293/00; C08F261/00; C08F261/02; C08F261/04
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
170 words
A process according to claim 1, in which the tetravalent cerium salt is selected from the group consisting of cerium sulfate, cerium nitrate, ammonium cerium sulfate, ammonium cerium nitrate, ammonium cerium pyrophosphate and cerium iodide, and the cerium salt is added in an aqueous solution containing 0.3-1 N of an acid selected from the group consisting of nitric acid, hydrochloric acid, sulfuric acid and formic acid, the cerium salt being added in an amount in the range of 0.05 to 2 molar percent based on the moles of vinyl monomer, from 5 to 30 percent by weight of the cerium salt being added during the initial stage of the graft copolymerization, from 5 to 15 percent by weight of the cerium salt being addeD after substantial completion of the reaction of the vinyl monomer with said first portion of the polyvinyl alcohol and prior to addition of the final portion of polyvinyl alcohol, and the balance of the cerium salt being added during the progress of the graft copolymerization reaction.
Claim 2
Dependent Claim
68 words
A process according to claim 1, in which the vinyl monomer is selected from the group consisting of acrylates and methacrylates having an alkyl group of one to 18 carbon atoms, acrylonitrile, methacrylonitrile, styrene, Alpha -methylstyrene, p-chlorostyrene, vinyl esters of fatty acids having one to 18 carbon atoms, crotonic acid esters having an alkyl group of one to 18 carbon atoms, vinyl chloride, vinylidene chloride and mixtures thereof.
Claim 3
Dependent Claim
74 words
A process according to claim 1, in which the reaction mixture also contains up to 5 percent by weight, based on the weight of said vinyl monomer, of an additional monomer selected from the group consisting of polymerizable unsaturated carboxylic acids and esters thereof in which the alkyl group contains one to 18 carbon atoms; acrylamide, methacrylamide, N-methylolacrylamide and ethers thereof; hydroxyethyl methacrylate, hydroxyethyl acrylate, glycidyl methacrylate, glycidyl acrylate, vinyl crotonate and mixtures thereof.
Claim 4
Dependent Claim
51 words
A process according to claim 3 in which the vinyl monomer comprises a mixture of from 5 to 70 percent by weight of vinyl monomer yielding a polymer having glass transition temperature below 10* C. and the balance is vinyl monomer yielding a polymer having glass transition temperature above 30* C.
Claim 5
Dependent Claim
25 words
A process according to claim 1, in which the polyvinyl alcohol is a single polyvinyl alcohol or a blend of two or more polyvinyl alcohols.
Claim 6
Dependent Claim
22 words
A process according to claim 1, in which the pH of the reaction mixture is maintained below 6.0 during the polymerization reaction.
Claim 7
Dependent Claim
32 words
A process according to claim 1, in which the temperature of the reaction mixture is maintained in the range of from about 20* C. to about 80* C. during the polymerization reaction.
References Cited (Backward Citations)
US2922768A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-08-27 | 1977-02-26 | 1977-08-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-27 | 1981-02-26 | 1981-08-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-27 | 1985-02-26 | 1985-08-28 | $7700.00 | Window Closed / Lapsed |