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US3830274A
Expired / Lapsed
US
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Elastomer blends and tire sidewalls prepared therefrom
Assignee: Goodyear Tire and Rubber Co
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Filing: 1972-05-11
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Granted: 1974-08-20
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Expires: 1992-05-11
Abstract
Abstract An elastomer blend and pneumatic tire sidewall prepared therefrom where said elastomeric blend comprises specific amounts of cis 1,4-isoprene selected from natural and snythetic rubber, an ethylene-propylene-conjugated diene terpolymer, bromobutyl rubber and a cis 1,4-polybutadiene having a gel content of less than 3 percent, a number average molecular weight in the range of about 80,000 to about 300,000 and a heterogeneity index of about 3.5 to about 4.2, wherein said elastomeric blend cured with sulfur has a 300 percent modulus in the range of about 3 to 4 meganewtons per square meter. The elastomeric blend has particular utility as an outer sidewall layer and a cover strip layer adhered to the rubber sidewall portion of a pneumatic rubber tire. The elastomeric blend exhibits a substantially improved break resistance to flexing at elevated temperatures and a substantially improved ability to adhere to a pneumatic rubber tire carcass.
Inventors
- 👤 H Waser
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 22:55
CPC Classifications
B; B60; B60C; B60C13/00; B60C13/04; Y; Y10; Y10S; Y10S152/00; Y10S152/12
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
77 words
A pneumatic rubber tire according to claim 1 where a sample of said elastomeric blend, when cured with sulfur, 4.44 inches long by 0.9 inch wide with a thickness of 0.075 inch and a 0.3 inch diameter perforation in its center requires at least about 26 minutes to break when clamped on both ends and flexed in a 93* C. atmosphere at the rate of 360 cycles per minute between elongations of 10 percent and 61 percent.
Claim 2
Dependent Claim
149 words
A pneumatic tire according to claim 1 where the said carcass comprises a sulfur cured elastomer selected from at least one of natural rubber, cis 1,4-polyisoprene, cis 1,4-polybutadiene and 1,3-butadiene-styrene copolymers and where, in said elastomeric blend of said outer sidewall layer and cover strip layer, the terpolymer is an ethylene-propylene-dicyclopentadiene terpolymer, the cis 1,4-polybutadiene has a heterogeneity index of about 3.5 to about 5 and a number average molecular weight in the range of about 80,000 to about 170,000, where the bromobutyl rubber is a copolymer of isobutylene and isoprene containing about 85 to about 95 weight percent isobutylene and further containing about 1.8 to about 2.4 weight percent bromine and about 1 to about 1.5 mole percent unsaturation and where said elastomeric blend, when sulfur cured, is characterized by having a 300 percent modulus at 25* C. in the range of about 3.3 to about 3.7 (MN/M2).
Claim 3
Dependent Claim
65 words
A pneumatic tire according to claim 3, wherein said outer sidewall layer is colored white with titanium dioxide pigment and is comprised of about 40 to about 60 weight percent of the polyisoprene, about 20 to about 30 weight percent of the terpolymer, about 20 to about 40 weight percent of the bromobutyl rubber and about 20 to about 30 weight percent of the polybutadiene.
Claim 4
Dependent Claim
143 words
An elastomeric blend suitable for said outer sidewall layer and cover strip layer of claim 1 which comprises an elastomeric blend of from about 20 to about 60 weight percent cis 1,4-polyisoprene selected from natural and synthetic natural rubber, from about 20 to about 35 weight percent ethylene, propylene, nonconjugated diene terpolymer, from about 20 to about 45 weight percent bromobutyl rubber and from about 20 to about 30 weight percent polybutadiene rubber having a cis 1,4-content of at least about 95 percent, a gel content of less than about 3 weight percent, a number average molecular weight in the range of about 80,000 to about 300,000 and a heterogeneity index of about 3.5 to about 4.2, wherein said elastomeric blend cured with sulfur has a 300 percent modulus in the range of about 3 to about 4 meganewtons per square meter (MN/M2).
Claim 5
Dependent Claim
132 words
The elastomeric blend of claim 5 where said cis 1,4-polyisoprene is selected from natural rubber of at least No. 1 pale crepe quality and from polyisoprene having a cis 1,4-content of at least about 95 percent, the said rubbery ethylene, propylene, nonconjugated diene terpolymer comprises an ethylene to propylene weight ratio of about 50:50 to about 75:25 and contains about 2 to about 10 weight percent units derived from a diene selected from dicyclopentadiene, 1,4-hexadiene and ethylidene bicycloheptene, the said bromobutyl rubber is prepared by solution brominating an isobutylene/isoprene copolymer to form the bromobutyl rubber containing about 1.7 to about 2.5 weight percent bromine and about 1 to about 1.5 weight percent unsaturation where the said polybutadiene has a number average molecular weight in the range of about 80,000 to about 300,000.
Claim 6
Dependent Claim
76 words
The elastomeric blend of claim 6 where a sample of said elastomer blend, when cured with suLfur, 4.44 inches long by 0.9 inch wide with a thickness of 0.075 inch inch and a 0.3 inch diameter perforation in its center requires at least about 26 minutes to break when clamped on both ends and flexed in a 93* C. atmosphere at the rate of 360 cycles per minute between elongations of 10 percent and 61 percent.
Claim 7
Dependent Claim
111 words
The elastomeric blend of claim 6 where said terpolymer is an ethylene-propylene-dicyclopentadiene terpolymer, the cis 1,4-polybutadiene has a heterogeneity index of about 3.5 to about 5 and a number average molecular weight in the range of about 80, 000 to about 170,000, where the bromobutyl rubber is a copolymer of isobutylene and isoprene containing about 85 to about 95 weight percent isobutylene and further containing about 1.8 to about 2.4 weight percent bromine and about 1 to about 1.5 mole percent unsaturation and where said elastomeric blend, when sulfur cured, is characterized by having a 300 percent modulus at 25* C. in the range of about 3.3 to about 3.7 (MN/M2).
Claim 8
Dependent Claim
57 words
The elastomeric blend of claim 8 colored white with titanium dioxide and is comprised of about 40 to about 60 weight percent of the polyisoprene, about 20 to about 30 weight percent of the terpolymer, about 20 to about 40 weight percent of the bromobutyl rubber and about 20 to about 30 weight percent of the polybutadiene.
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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) | 1977-08-19 | 1978-02-18 | 1978-08-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-08-19 | 1982-02-18 | 1982-08-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-08-19 | 1986-02-18 | 1986-08-20 | $7700.00 | Window Closed / Lapsed |