US4434266A
Expired / Lapsed
US
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Method for rubber treatment and the rubber thus treated
Assignee: Flexsys America LP
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Filing: 1982-09-23
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Granted: 1984-02-28
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Expires: 2002-09-23
Abstract
Abstract Diene rubber is treated with a maleic acid half ester, optionally in the presence of sulfur or an organic sulfur compound capable of generating a thiyl radical at an appropriate temperature (above 130 DEG C.) for a time sufficient to increase the green strength or tack of the diene rubber, but insufficient to decrease its tack. The treated diene rubber exhibits improved fabricability in the production of rubber products.
Inventors
- 👤 Chester D. Trivette, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 17:59
CPC Classifications
C; C08; C08C; C08C19/00; C08C19/28
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
138 words
The method of improving the properties of diene rubber comprising treating diene rubber by mastication with from 0.1 to 20 parts by weight per 100 parts diene rubber by weight of (B) a maleic acid half ester which is the product of the reaction of one mole of a mono- or poly-hydric alcohol of the formula R(OH) n with n moles or less of maleic acid or anhydride, where R is alkyl of 1-20 carbon atoms, cycloalkyl of 3-20 carbon atoms, aryl of 6-20 carbon atoms or aralkyl or alkaryl of 7-20 carbon atoms, optionally substituted with one or more non-reactive substituents selected from halogen, nitro and alkoxy or carboxy of 1-5 carbon atoms, and n is an integer of from 1-4 at an appropriate temperature above 130° C. for a time of from 0.1 to 20 minutes.
Claim 2
Independent Claim
138 words
The method of improving the properties of diene rubber comprising treating diene rubber by mastication with from 0.1 to 20 parts by weight per 100 parts diene rubber by weight of (B) a maleic acid half ester which is the product of the reaction of one mole of a mono- or poly-hydric alcohol of the formula R(OH) n with n moles or less of maleic acid or anhydride, where R is alkyl of 1-20 carbon atoms, cycloalkyl of 3-20 carbon atoms, aryl of 6-20 carbon atoms or aralkyl or alkaryl of 7-20 carbon atoms, optionally substituted with one or more non-reactive substituents selected from halogen, nitro and alkoxy or carboxy of 1-5 carbon atoms, and n is an integer of from 1-4 at an appropriate temperature above 130° C. for a time of from 0.1 to 20 minutes.
Claim 3
Dependent Claim
24 words
The method of claim 1 wherein the diene rubber is treated for a time sufficient to increase both its green strength and its tack.
Claim 4
Dependent Claim
14 words
The method of claim 1 wherein the treatment temperature is at least 150° C.
Claim 5
Dependent Claim
22 words
The method of claim 1 wherein R is selected from alkylphenyl and aliphatic hydrocarbon radicals of no more than eight carbon atoms.
Claim 6
Dependent Claim
36 words
The method of claim 3 wherein (A) sulfur or an organic sulfur compound capable of generating thiyl radicals is present in an amount of from 0.01-15 parts by weight per 100 parts diene rubber by weight.
Claim 7
Dependent Claim
9 words
The method of claim 5 wherein (A) comprises 2,2'-dithiobisbenzothiazole.
Claim 8
Dependent Claim
46 words
The method of claim 5 wherein the treatment time is from 0.5 to 15 minutes, the temperature is at least 160° C. and (A) and (B) are present in amounts of from 0.02-4 and 0.2-8 parts by weight, respectively, per 100 parts diene rubber by weight.
Claim 9
Dependent Claim
11 words
The method of claim 5 wherein the diene rubber comprises polyisoprene.
Claim 10
Dependent Claim
9 words
The method of claim 5 wherein (A) is 2,2'-dithiobisbenzothiazole.
Claim 11
Dependent Claim
45 words
The method of claim 5 wherein the time is from 1-10 minutes, the treatment temperature is from 160° to 210° C., and (A) and (B) are present in amounts of from 0.05-0.25 and 0.25-5 parts by weight, respectively, per 100 parts diene rubber by weight.
Claim 12
Dependent Claim
11 words
The method of claim 10 wherein the diene rubber comprises polyisoprene.
Claim 13
Dependent Claim
9 words
The method of claim 10 wherein (A) is sulfur.
Claim 14
Dependent Claim
17 words
The method of claim 10 wherein (A) is an organic sulfur compound capable of generating thiyl radicals.
Claim 15
Dependent Claim
130 words
The method of claim 13 wherein (A) is selected from polymeric polysulfides and compounds of the formula (R 1 S x )yR 2 , wherein x is an integer of 1-5, y is an integer of from 1-4, R 2 is a radical selected from aliphatic hydrocarbon radicals of 3-18 carbon atoms optionally containing one or more ether or ester linkages and optionally substituted by one or more nitro, amino or carboxyl groups; cycloalkyl of 3-10 carbon atoms; benzyl or phenyl optionally ring-substituted by one or more nitro, amino, carboxyl, or 1-5 carbon-atom alkyl groups; or benzothiazyl; dialkylthiocarbamoyl; alkylamino of 4-12 carbon atoms; morpholino; or dialkylthiophosphoroyl; R 2 having a valence of y; and R 1 is hydrogen or a radical selected from the same group as R 2 .
Claim 16
Dependent Claim
10 words
The method of claim 14 wherein (A) is 2,2' dithiobisbenzothiazole.
Claim 17
Dependent Claim
11 words
The method of claim 15 wherein the diene rubber comprises polyisoprene.
Claim 18
Dependent Claim
10 words
The method of claim 15 wherein carbon black is present.
Claim 19
Dependent Claim
11 words
The method of claim 15 wherein a non-black filler is present.
Claim 20
Dependent Claim
18 words
The method of claim 18 wherein the non-black filler is selected from clay, talc, calcium carbonate and silica.
Claim 21
Dependent Claim
12 words
The method of claim 15 wherein the diene rubber comprises natural rubber.
Claim 22
Dependent Claim
14 words
The method of claim 15 wherein the diene rubber includes polybutadiene or styrene/butadiene rubber.
Claim 23
Dependent Claim
26 words
The method of claim 16 and the additional step of incorporating from 10 to 100 parts by weight of diene rubber not present during the treatment.
Claim 24
Dependent Claim
8 words
The product of the method of claim 1.
Claim 25
Dependent Claim
8 words
The product of the method of claim 9.
Claim 26
Dependent Claim
8 words
The product of the method of claim 16.
References Cited (Backward Citations)
US2388905A
Cited
US4254013A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-02-27 | 1987-08-29 | 1988-02-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-02-27 | 1991-08-29 | 1992-02-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-02-27 | 1995-08-29 | 1996-02-28 | $7700.00 | Window Closed / Lapsed |