US4046834A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Treatment of vulcanized rubber
Assignee: NRI Pennsylvania Inc
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Filing: 1974-01-08
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Granted: 1977-09-06
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Expires: 1994-01-08
Abstract
Abstract The invention provides finely divided vulcanized rubber having a particle size of generally less than 20 microns for re-use in the rubber industry. Vulcanizates produced from compositions containing the finely divided vulcanized rubber, either as the sole rubber component or in admixture with unvulcanized rubber, have properties significantly better than those of vulcanizates of similar compositions containing conventional reclaimed rubbers. Vulcanized rubber is converted into the finely divided rubber by the steps of (1) contacting vulcanized rubber with a fatty acid, (2) contacting the product of step (1) with a solid alkali and (3) forming a dispersion of the product of step (2) with a liquid which dissolves the alkali but does not affect the rubber. Alternatively, the finely divided vulcanized rubber results from the steps of (1) contacting the vulcanized rubber with a liquid effective to swell the rubber and thereby weaken it e.g. tetrahydrofuran, (2) comminuting the weakened material and (3) removing the liquid from the comminuted material.
Inventors
- 👤 Timothy Charles Philip Lee
- 👤 William Millns
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 08:45
CPC Classifications
C; C08; C08J; C08J11/00; C08J11/04; C08J11/06; C08J3/00; C08J3/12; C08L; C08L19/00; C08L19/003; C08J2321/00; Y; Y02; Y02W; Y02W30/00; Y02W30/50; Y02W30/62
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
33 words
A finely-divided, vulcanized, recycled rubber comprised predominently of particles having a particle size less than 20 microns, said particles being further characterized by the property of separating out from an admixture with water.
Claim 2
Dependent Claim
33 words
A finely-divided, vulcanized, recycled rubber comprised predominently of particles having a particle size less than 20 microns, said particles being further characterized by the property of separating out from an admixture with water.
Claim 3
Dependent Claim
25 words
A finely-divided, vulcanized, recycled rubber as claimed in claim 1 wherein at least 90% of said particles have a particle size less than 20 microns.
Claim 4
Dependent Claim
25 words
A cured rubber composition, said rubber composition, before curing, comprising a finely-divided, vulcanized, recycled rubber as claimed in claim 1 and an unvulcanized, non-recycled rubber.
Claim 5
Dependent Claim
57 words
A finely-divided, vulcanized, recycled rubber comprised predominently of particles having a particle size less than 20 microns, said finely-divided rubber being further characterized by yielding a vulcanizate having a tensile strength of above 9 MN/m 2 and a tear strength above 55 N/Std. when a rubber composition containing said particles as the sole rubber component is vulcanized.
Claim 6
Dependent Claim
57 words
A finely-divided, vulcanized, recycled rubber comprised predominently of particles having a particle size less than 20 microns, said finely-divided rubber being further characterized by yielding a vulcanizate having a tensile strength of above 9 MN/m 2 and a tear strength above 55 N/Std. when a rubber composition containing said particles as the sole rubber component is vulcanized.
Claim 7
Dependent Claim
25 words
A finely-divided, vulcanized, recycled rubber as claimed in claim 4 wherein at least 90% of said particles have a particle size less than 20 microns.
Claim 8
Dependent Claim
25 words
A cured rubber composition, said rubber composition, before curing, comprising a finely-divided, vulcanized, recycled rubber as claimed in claim 4 and an unvulcanized, non-recycled rubber.
Claim 9
Dependent Claim
105 words
A finely-divided, vulcanized, recycled rubber comprised predominently of particles having a particle size less than 20 microns, said finely-divided rubber being further characterized by yielding a vulcanizate having a tensile strength of above 9 MN/m 2 and a tear strength above 55 N/Std. when a rubber composition containing said particles as the sole rubber component is vulcanized by compounding 100 parts by weight of said particles with 2 parts of zinc oxide, 1 part of stearic acid, 1 part of polymerized 1,2-dihydro 2,2,4-trimethylquinoline, 0.27 parts of cyclohexyl-benzthiazyl-sulphenanide, 0.24 parts of diphenylguanidine and 0.53 parts of sulfur, and press molded to optimum cure at 150° C.
Claim 10
Dependent Claim
105 words
A finely-divided, vulcanized, recycled rubber comprised predominently of particles having a particle size less than 20 microns, said finely-divided rubber being further characterized by yielding a vulcanizate having a tensile strength of above 9 MN/m 2 and a tear strength above 55 N/Std. when a rubber composition containing said particles as the sole rubber component is vulcanized by compounding 100 parts by weight of said particles with 2 parts of zinc oxide, 1 part of stearic acid, 1 part of polymerized 1,2-dihydro 2,2,4-trimethylquinoline, 0.27 parts of cyclohexyl-benzthiazyl-sulphenanide, 0.24 parts of diphenylguanidine and 0.53 parts of sulfur, and press molded to optimum cure at 150° C.
Claim 11
Dependent Claim
25 words
A finely-divided, vulcanized, recycled rubber as claimed in claim 7 wherein at least 90% of said particles have a particle size less than 20 microns.
Claim 12
Dependent Claim
25 words
A cured rubber composition, said rubber composition, before curing, comprising a finely-divided, vulcanized, recycled rubber as claimed in claim 7 and an unvulcanized, non-recycled rubber.
Claim 13
Dependent Claim
15 words
The finely-divided rubber of claim 2 wherein said rubber, before recycling, comprises whole tyre crumb.
Claim 14
Dependent Claim
15 words
The finely-divided rubber of claim 5 wherein said rubber, before recycling, comprises whole tyre crumb.
Claim 15
Dependent Claim
15 words
The finely-divided rubber of claim 8 wherein said rubber, before recycling, comprises whole tyre crumb.
Claim 16
Dependent Claim
25 words
A cured rubber composition, said rubber composition, before curing, comprising a finely-divided, vulcanized, recycled rubber as claimed in claim 2 and an unvulcanized, nonrecycled rubber.
Claim 17
Dependent Claim
26 words
A finely-divided, recycled rubber as claimed in claim 8, said recycled rubber particles being further characterized by the property of separating out from admixtures with water.
Claim 18
Dependent Claim
25 words
A cured rubber composition, said rubber composition, before curing, comprising a finely-divided, vulcanized, recycled rubber as claimed in claim 14 and an unvulcanized, nonrecycled rubber.
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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) | 1980-09-05 | 1981-03-07 | 1981-09-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-09-05 | 1985-03-07 | 1985-09-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-09-05 | 1989-03-07 | 1989-09-06 | $7700.00 | Window Closed / Lapsed |