Tire with white sidewall
AssigneeThe Goodyear Tire & Rubber Company
InventorsPaul Harry Sandstrom, George Philemon Patitsas, Thomas Joseph Segatta
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Abstract
This invention relates to a pneumatic rubber tire having a rubber sidewall with at least a portion of its outer surface being composed of white rubber devoid of carbon black reinforcement and composed of an elastomer composition prepared as a combination of EPDM, chlorobutyl rubber, diene-based elastomers and liquid EPDM. The liquid EPDM component replaces at least a portion of a traditionally used naphthenic/paraffinic processing oil.
Claims20
A pneumatic rubber tire having a rubber sidewall composed of a carbon black reinforced rubber composition wherein said sidewall also has, as at least a portion of its outer surface, a white rubber composition essentially devoid of carbon black reinforcement, wherein said white sidewall composition is comprised of, based on 100 parts by weight rubber (phr):
- about 20 to about 45 phr of at least one diene rubber;
- about 45 to about 75 phr of at least one butyl rubber;
- about 2 to about 10 phr of at least one first EPDM rubber wherein said EPDM rubber further comprises,
- a ratio of ethylene units to propylene units of from about 10/90 to 90/10,
- about 1 to about 15% of a non-conjugated diene on a percentage weight basis,
- said first EPDM rubber having a molecular weight of greater than about 75,000 to about 1 million;
- about 2 to about 25 phr of at least one second EPDM rubber wherein said second EPDM rubber further comprises,
- a ratio of ethylene units to propylene units of from about 20/80 to 80/20,
- about 1 to about 15% of a non-conjugated diene on a percentage weight basis,
- said second EPDM rubber having a molecular weight of about 10,000 to about 50,000;
- and
- about 10 to about 55 phr of a titanium dioxide pigment.
A process for improving the ozone resistance of a pneumatic rubber tire having a rubber sidewall composed of a carbon black reinforced rubber composition wherein said sidewall also has, as at least a portion of its outer surface, a white rubber composition devoid of carbon black reinforcement, wherein said white sidewall composition is comprising a diene rubber, a butyl rubber, and a titanium dioxide, said process comprising the step of
- blending at least one first EPDM rubber
- wherein said first EPDM rubber further comprises,
- a ratio of ethylene units to propylene units of from about 10/90 to 90/10,
- from about 1 to about 15% of a non-conjugated diene on a percentage weight basis,
- said first EPDM rubber having a molecular weight of greater than about 75,000 to about 1 million;
- with
- at least one second EPDM rubber
- wherein said second EPDM rubber further comprises,
- a ratio of ethylene units to propylene units of from about 20/80 to 80/20,
- from about 1 to about 15% of a non-conjugated diene on a percentage weight basis,
- said second EPDM rubber having a molecular weight of about 10,000 to about 50,000.
Dependencies are inferred from the claim text.