Patent US3957737A successfully refreshed from Google Patents.
US3957737A
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Method for the preparation of rubbers with low molecular weights through degradation of macromolecular polyenes, and the products thus obtained
Assignee: L'INSTITUT DE RECHERCHE APPLIQUEE SUR LES POLYMERES (IRA/P)
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Filing: 1975-01-24
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Granted: 1976-05-18
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Expires: 1995-01-24
Abstract
Abstract An unsaturated hydrocarbon elastomer with a high molecular weight is reacted upon an oxidizer and a reducer forming a redox couple, in an organic solvent medium in the absence of air or in an aqueous medium, the oxidizer being selected from the group consisting of hydrogen peroxide and organic peroxides, and the reducer being selected from the group consisting of sulphinic acids and their derivatives and of hydrazine and its derivatives. The pasty to liquid materials obtained give, after having been vulcanized and possibly reinforced, elastomeric products.
Inventors
- 👤 Rene Pautrat
- 👤 Jacques Marteau
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 15:20
CPC Classifications
C; C08; C08C; C08C19/00; C08C19/08; Y; Y10; Y10S; Y10S526/00; Y10S526/914; Y10S526/915
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
153 words
A method of preparing low molecular weight rubbers with pasty to semi-liquid or liquid consistencies through degradation of macromolecular polyenes, comprising reacting an unsaturated hydrocarbon elastomer with a high molecular weight upon an oxidizer and a reducer forming a redox couple, the molar ratio between the oxidizer and the reducer lying between 0.5 and 6, in a organic solvent medium containing 1% to 10% by weight of the said elastomer and in the absence of air, or in an aqueous medium containing 10% to 60% by weight of the said elastomer, the oxidizer being selected from the group consisting of hydrogen peroxide and organic peroxides, and the reducer being selected from the group consisting of sulphinic acids and their derivatives and of hydrazine and its derivatives, at a temperature lying between room temperature and 250°C, the proportion of the reducer being of 100 millimoles to 1 millimole per 100 g of said elastomer.
Claim 2
Independent Claim
153 words
A method of preparing low molecular weight rubbers with pasty to semi-liquid or liquid consistencies through degradation of macromolecular polyenes, comprising reacting an unsaturated hydrocarbon elastomer with a high molecular weight upon an oxidizer and a reducer forming a redox couple, the molar ratio between the oxidizer and the reducer lying between 0.5 and 6, in a organic solvent medium containing 1% to 10% by weight of the said elastomer and in the absence of air, or in an aqueous medium containing 10% to 60% by weight of the said elastomer, the oxidizer being selected from the group consisting of hydrogen peroxide and organic peroxides, and the reducer being selected from the group consisting of sulphinic acids and their derivatives and of hydrazine and its derivatives, at a temperature lying between room temperature and 250°C, the proportion of the reducer being of 100 millimoles to 1 millimole per 100 g of said elastomer.
Claim 3
Dependent Claim
15 words
A method according to claim 1, wherein the reaction temperature lies between 60° and 150°C.
Claim 4
Dependent Claim
25 words
A method according to claim 1 wherein the reaction is effected under atmospheric pressure, at a temperature below the boiling point of the said medium.
Claim 5
Dependent Claim
34 words
A method according to claim 1 wherein a metal salt of ethylenediaminetetraacetic acid is used as an oxidation catalyst, in the proportion of 0.5 to 3% by weight on the basis of said elastomer.
Claim 6
Dependent Claim
26 words
A method according to claim 1 wherein the depolymerized rubber obtained is purified by a series of dissolutions and reprecipitations by means of a solvent/nonsolvent couple.
Claim 7
Dependent Claim
13 words
A method according to claim 1 wherein the produced depolymerized rubber is vulcanized.
Claim 8
Dependent Claim
15 words
A method according to claim 1 wherein the produced depolymerized rubber is reinforced and vulcanized.
Claim 9
Dependent Claim
28 words
A method according to claim 1 wherein said elastomer used as the starting material is selected from the group consisting of natural and synthetic polyisoprenes, polybutadienes and polychloroprenes.
Claim 10
Dependent Claim
15 words
A method according to claim 8 wherein the reaction temperature lies between 60°C and 150°C.
Claim 11
Dependent Claim
34 words
A method according to claim 9 wherein a metal salt of ethylenediaminetetraacetic acid is used as an oxidation catalyst, in the proportion of 0.5 to 3% by weight on the basis of said elastomer.
Claim 12
Dependent Claim
26 words
A method according to claim 9 wherein the depolymerized rubber obtained is purified by a series of dissolutions and reprecipitations by means of a solvent/non-solvent couple.
Claim 13
Dependent Claim
13 words
A method according to claim 11 wherein the depolymerized rubber produced is vulcanized.
Claim 14
Dependent Claim
15 words
A method according to claim 11 wherein the depolymerized rubber produced is reinforced and vulcanized.
Claim 15
Dependent Claim
46 words
A method according to claim 1 wherein the molar ratio between the oxidizer and the reducer is in the range of 2 to 5 and the proportion of the reducer is in the range of 80 millimoles to 5 millimoles per 100 g of said elastomer.
Claim 16
Dependent Claim
26 words
Rubbers with low numerical molecular weights, lying between 5,000 and 100,000, with pasty to semi-liquid or liquid consistencies, produced by the method according to claim 1.
Claim 17
Dependent Claim
20 words
Rubbers with low numerical molecular weights, lying between 5,000 and 100,000, vulcanized, produced by the method according to claim 6.
Claim 18
Dependent Claim
22 words
Rubbers with low numerical molecular weights, lying between 5,000 and 100,000 reinforced and vulcanized, produced by the method according to claim 7.
Claim 19
Independent Claim
140 words
A method of preparing low molecular weight rubbers with pasty to semi-liquid or liquid consistencies through degradation of macromolecular polyenes, comprising reacting an unsaturated hydrocarbon elastomer with a high molecular weight upon an oxidizer and a reducer forming a redox couple, the molar ratio between the oxidizer and the reducer lying between 0.5 and 6, in an organic solvent medium containing 1% to 10% by weight of the said elastomer and in the absence of air, or in an aqueous medium containing 10% to 60% by weight of the said elastomer, the oxidizer being selected from the group consisting of hydrogen peroxide and organic peroxides, and the reducer being a sulphinic acid compound, at a temperature lying between room temperature and 250°C, the proportion of the reducer being of 100 millimoles to 1 millimoles per 100 g of said elastomer.
Claim 20
Independent Claim
140 words
A method of preparing low molecular weight rubbers with pasty to semi-liquid or liquid consistencies through degradation of macromolecular polyenes, comprising reacting an unsaturated hydrocarbon elastomer with a high molecular weight upon an oxidizer and a reducer forming a redox couple, the molar ratio between the oxidizer and the reducer lying between 0.5 and 6, in an organic solvent medium containing 1% to 10% by weight of the said elastomer and in the absence of air, or in an aqueous medium containing 10% to 60% by weight of the said elastomer, the oxidizer being selected from the group consisting of hydrogen peroxide and organic peroxides, and the reducer being a sulphinic acid compound, at a temperature lying between room temperature and 250°C, the proportion of the reducer being of 100 millimoles to 1 millimoles per 100 g of said elastomer.
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) | 1979-05-18 | 1979-11-17 | 1980-05-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-05-18 | 1983-11-17 | 1984-05-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-05-18 | 1987-11-17 | 1988-05-18 | $7700.00 | Window Closed / Lapsed |