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Microwave devulcanization of rubber

Assignee: Goodyear Tire and Rubber Co
•
Filing: 1976-01-06
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Granted: 1978-08-01
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Expires: 1996-01-06
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Abstract

Abstract Elastomer waste may be devulcanized without depolymerization to a material capable of recompounding and revulcanization into a product having physical properties essentially equivalent to the original vulcanizate. Devulcanization is accomplished by application of a controlled dose of microwave energy to sized material, preferably in a continuous process.

Inventors

  • 👤 Donald S. Novotny
  • 👤 Richard L. Marsh
  • 👤 Frank C. Masters
  • 👤 David N. Tally

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-01 12:45
CPC Classifications
C; C08; C08J; C08J11/00; C08J11/04; C08J11/10; C08J11/12; C08J3/00; C08J3/28; H; H05; H05B; H05B6/00; H05B6/64; C08J2321/00; Y; Y02; Y02W; Y02W30/00; Y02W30/50; Y02W30/62; Y10; Y10S; Y10S264/00; Y10S264/46

Claims Analysis

Total Claims: 11
Claim 1
Independent Claim 53 words
The method of devulcanizing sulfur-vulcanized elastomer containing polar groups which comprises applying a controlled dose of microwave energy of between 915 and 2450 MHz and between 41 and 177 watt-hours per pound in an amount sufficient to sever substantially all carbon-sulfur and sulfur-sulfur bonds and insufficient to sever significant amount of carbon-carbon bonds.
Claim 2
Independent Claim 53 words
The method of devulcanizing sulfur-vulcanized elastomer containing polar groups which comprises applying a controlled dose of microwave energy of between 915 and 2450 MHz and between 41 and 177 watt-hours per pound in an amount sufficient to sever substantially all carbon-sulfur and sulfur-sulfur bonds and insufficient to sever significant amount of carbon-carbon bonds.
Claim 3
Dependent Claim 18 words
The method of claim 1 wherein the elastomer is in continuous motion while present in the microwave field.
Claim 4
Dependent Claim 19 words
The method of claim 2 wherein the elastomer is maintained in continuous motion by means of a steel auger.
Claim 5
Dependent Claim 35 words
The method of claim 1 wherein the microwave frequency is between 915 and 2450 MHz; the dose is between 75 and 100 watt-hours per pound; and the elastomer temperature is between 450° and 800° F.
Claim 6
Dependent Claim 54 words
The method of claim 1 wherein the elastomer is maintained in continuous motion by means of a steel auger while present in the microwave field; the microwave frequency is between 915 and 2450 MHz; the dose is between 41 and 177 watt-hours per pound; and the elastomer temperature is between 450° and 800° F.
Claim 7
Dependent Claim 11 words
The method of claim 1 wherein the elastomer is ethylene-propylene-diene rubber.
Claim 8
Dependent Claim 11 words
The method of claim 2 wherein the elastomer is ethylene-propylene-diene rubber.
Claim 9
Dependent Claim 11 words
The devulcanized elastomeric product made by the process of claim 1.
Claim 10
Dependent Claim 11 words
The devulcanized elastomeric product made by the process of claim 2.
Claim 11
Dependent Claim 11 words
The method of claim 5 wherein the elastomer is ethylene-propylene-diene rubber.

References Cited (Backward Citations)

US3773638A Cited
US3725314A Cited
US3766031A Cited
US3937774A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1981-07-31 1982-01-30 1982-08-01 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1985-07-31 1986-01-30 1986-08-01 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1989-07-31 1990-01-30 1990-08-01 $7700.00 Window Closed / Lapsed

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