US4110526A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for production of casting syrups
Assignee: Sumitomo Chemical Co Ltd
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Filing: 1977-01-31
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Granted: 1978-08-29
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Expires: 1997-01-31
Abstract
Abstract In the production of a casting syrup, useful in a continuous casting process for manufacture of cast plates, by partial polymerization of methyl methacrylate or its mixture with at least one unsaturated vinyl compound copolymerizable therewith in an amount of not more than about 20% by weight based on methyl methacrylate, an improved method wherein the partial polymerization is carried out in the presence of a thiodicarboxylic acid ester of the formula: R.sub.3 OOCR.sub.1 --S--R.sub.2 COOR.sub.4 wherein R 1 and R 2 are each an alkylene group having 1 to 6 carbon atoms and R 3 and R 4 are each an alkyl group having 1 to 24 carbon atoms as a stabilizer using an azo compound as a polymerization initiator, whereby a casting syrup having a suitable viscosity with a good workability on casting and affording a cast plate of high thermal stability on completion of the polymerization is obtainable.
Inventors
- 👤 Takaki Hamada
- 👤 Hiroyuki Kanazawa
- 👤 Masataka Yanase
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 17:35
CPC Classifications
C; C08; C08F; C08F20/00; C08F20/02; C08F20/10; C08F20/12; C08F20/14; C08F2/00; C08F2/02
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
136 words
In the production of a casting syrup, useful in a continuous casting process for the production of cast plates, by partial polymerization of methyl methacrylate or a mixture thereof with at least one unsaturated vinyl compound copolymerizable therewith in an amount of less than 20% by weight based upon methyl methacrylate, the improvement which comprises conducting the partial polymerization in the presence of from about 0.005 to 1% by weight based on the total amount of the monomers of a thiodicarboxylic acid ester of the formula: R.sub.3 OOCR.sub.1 --S--R.sub.2 COOR.sub.4 wherein R 1 and R 2 are each an alkylene group having 1 to 6 carbon atoms and R 3 and R 4 are each an alkyl group having 1 to 24 carbon atoms as a stabilizer and using an azo compound as a polymerization initiator.
Claim 2
Dependent Claim
136 words
In the production of a casting syrup, useful in a continuous casting process for the production of cast plates, by partial polymerization of methyl methacrylate or a mixture thereof with at least one unsaturated vinyl compound copolymerizable therewith in an amount of less than 20% by weight based upon methyl methacrylate, the improvement which comprises conducting the partial polymerization in the presence of from about 0.005 to 1% by weight based on the total amount of the monomers of a thiodicarboxylic acid ester of the formula: R.sub.3 OOCR.sub.1 --S--R.sub.2 COOR.sub.4 wherein R 1 and R 2 are each an alkylene group having 1 to 6 carbon atoms and R 3 and R 4 are each an alkyl group having 1 to 24 carbon atoms as a stabilizer and using an azo compound as a polymerization initiator.
Claim 3
Dependent Claim
32 words
The method according to claim 1, wherein R 1 and R 2 are each methylene, ethylene or propylene and R 3 and R 4 are each decyl, dodecyl, tetradecyl, hexadecyl or octadecyl.
Claim 4
Dependent Claim
20 words
The method according to claim 1, wherein the thiodicarboxylic acid ester is dilauryl thiodipropionate, distearyl thiodipropionate or lauryl stearyl thiodipropionate.
Claim 5
Dependent Claim
22 words
The method according to claim 1, wherein the amount of the thiodicarboxylic acid ester is from about 0.01 to 0.2% by weight.
Claim 6
Dependent Claim
29 words
The method according to claim 1, wherein the amount of the azo compound is from about 0.001 to 1.0% by weight based on the total amount of the monomers.
Claim 7
Dependent Claim
23 words
The method according to claim 1, wherein the partial polymerization is carried out at a temperature of from about 60° to 200° C.
Claim 8
Dependent Claim
23 words
The method according to claim 6, wherein the partial polymerization is carried out at a temperature of from about 80° to 180° C.
Claim 9
Dependent Claim
35 words
A casting syrup produced by the process of claim 1, the polymer content of the syrup being from 10 to 40% by weight and the viscosity of the syrup being from 1 to 100 poise.
Claim 10
Dependent Claim
11 words
A cast plate prepared from the casting syrup of claim 8.
References Cited (Backward Citations)
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US3759881A
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US3957905A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-08-28 | 1982-02-27 | 1982-08-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-08-28 | 1986-02-27 | 1986-08-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-08-28 | 1990-02-27 | 1990-08-29 | $7700.00 | Window Closed / Lapsed |