US4748168A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rubber compositions for tire treads
Assignee: Yokohama Rubber Co Ltd
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Filing: 1987-04-30
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Granted: 1988-05-31
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Expires: 2007-04-30
Abstract
Abstract Rubber compositions suitable for tire treads are disclosed. Starting rubbers made up of at least one SBR of -20° C. to -40° C. in Tg and at least one SBR of lower than -45° C. in Tg are blended with specified amounts of carbon blacks having a N 2 SA of more than 120 m 2 /g and of softeners having a VGC of 0.90 to 0.98, whereby the compositions are provided with a storage shear modulus of less than 500 MPa at -30° C. The compositions are excellent in friction performance, abrasion resistance and low-temperature resistance.
Inventors
- 👤 Shinji Kawakami
- 👤 Makoto Misawa
- 👤 Takekazu Inoue
- 👤 Yasuhiro Ishikawa
- 👤 Hiroshi Hirakawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 01:36
CPC Classifications
C; C08; C08K; C08K3/00; C08K3/02; C08K3/04; B; B60; B60C; B60C1/00; B60C1/0016; C08L; C08L9/00; C08L9/06; C08K5/00; C08K5/01; C08L2205/00; C08L2205/02
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
169 words
A rubber composition for use in tire treads which comprises: (a) a starting rubber consisting essentially of one or more of a first styrene-butadiene copolymer rubber having a glass-transition temperature between -20° C. and -45° C., said first copolymer rubber being in an amount of 90-40 parts by weight, and one or more of a second styrene-butadiene copolymer rubber having a glass-transition temperature lower than 45° C., said second copolymer rubber being in an amount of 10-60 parts by weight; (b) 80-130 parts by weight of a carbon black having a specific surface area greater than 120 m 2 /g as determined by nitrogen adsorption, the amount being based on 100 parts by weight of said starting rubber; and (c) 20-90 parts by weight of a softener of a petroleum type having a viscosity-gravity constant between 0.90 and 0.98, the amount being based on 100 parts by weight of said starting rubber, whereby the composition is provided with a storage shear modulus smaller than 500 MPa at -30° C.
Claim 2
Dependent Claim
169 words
A rubber composition for use in tire treads which comprises: (a) a starting rubber consisting essentially of one or more of a first styrene-butadiene copolymer rubber having a glass-transition temperature between -20° C. and -45° C., said first copolymer rubber being in an amount of 90-40 parts by weight, and one or more of a second styrene-butadiene copolymer rubber having a glass-transition temperature lower than 45° C., said second copolymer rubber being in an amount of 10-60 parts by weight; (b) 80-130 parts by weight of a carbon black having a specific surface area greater than 120 m 2 /g as determined by nitrogen adsorption, the amount being based on 100 parts by weight of said starting rubber; and (c) 20-90 parts by weight of a softener of a petroleum type having a viscosity-gravity constant between 0.90 and 0.98, the amount being based on 100 parts by weight of said starting rubber, whereby the composition is provided with a storage shear modulus smaller than 500 MPa at -30° C.
Claim 3
Dependent Claim
20 words
The rubber composition of claim 1 wherein said first copolymer rubber has a styrene content of 30-50 percent by weight.
Claim 4
Dependent Claim
19 words
The rubber composition of claim 1 wherein said second copolymer has a styrene content of 20-30 percent by weight.
Claim 5
Dependent Claim
19 words
The rubber composition of claim 1 wherein said carbon black is a super or ultrasuper abrasion furnace carbon back.
Claim 6
Dependent Claim
14 words
The rubber composition of claim 1 wherein said softener is an aromatic process oil.
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) | 1991-05-31 | 1991-11-30 | 1992-05-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-05-31 | 1995-11-30 | 1996-05-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-05-31 | 1999-11-30 | 2000-05-31 | $7700.00 | Window Closed / Lapsed |