# US 5,341,863 A · Tire with tread composition

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- Number: US 5,341,863 A
- Document ID: US5341863A
- Status: Granted
- Kind: A
- Application number: 08/062,263
- Filed: 1993-05-17
- Granted: 1994-08-30
- Earliest claimed: 1993-05-17
- Assignees: The Goodyear Tire & Rubber Company
- Inventors: Paul H. Sandstrom; Raymond B. Roennau
- Web page: https://patentgrep.com/patent/US5341863A

## CPC

- C08L 21/00: Compositions of unspecified rubbers
- Y10S 152/905: Tread composition
- C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06)
- Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS

## Abstract

A pneumatic tire having a sulfur cured tread is provided comprised of at least one diene rubber and a low density polyethylene having a crystalline melt point in a range of about 104.degree. C. to about 115.degree. C., wherein the said LDPE is mixed with the said rubber at a temperature of about 120.degree. C. to about 170.degree. C. prior to sulfur vulcanizing the blend. A process is also provided for producing a tire in which a hot cured tire is removed from its rigid mold where the tread is comprised of at least one diene rubber and a low density polyethylene (LDPE) having a crystalline melt point in a range of about 104.degree. C. to about 115.degree. C.; and wherein the said LDPE is mixed with the said unvulcanized rubber at a temperature of about 120.degree. C. to about 170.degree. C.

## Claims

### Claim 1

A pneumatic rubber tire having a sulfur cured, diene rubber-based thread which is comprised of a blend, based on 100 parts by weight of sulfur curable diene rubber-based elastomers, of (A) 100 parts by weight of at least one sulfur vulcanizable diene based rubber, and (B) about 5 to about 15 parts by weight low density polyethylene (LDPE) having a density of about 0.91 to 0.918 gm/cc, a melt index of about 0.2 to about 20 and a crystalline melt point in a range of about 104.degree. C. to about 115.degree. C. wherein the said LDPE is mixed with the said rubber at a temperature of about 120.degree. C. to about 170.degree. C. prior to sulfur vulcanizing the blend.

### Claim 2 (depends on 1)

The tire of claim 1 where, in the tire tread, the diene rubber is natural cis 1,4-polyisoprene rubber.

### Claim 3 (depends on 1)

The tire of claim 1 where, in the tire thread, the said blend is comprised of, based on 100 parts by weight rubber, (A) about 55 to about 90 phr of natural cis 1,4-polyisoprene rubber and, correspondingly, about 45 to about 10 phr of at least one synthetic rubber selected from polybutadiene rubber and styrene/butadiene copolymer rubber, and (B) about 5 to about 15 phr of said LDPE.

### Claim 4 (depends on 1)

The tire of claim 1 wherein, in the tire tread, the said blend is comprised of, based on 100 parts by weight rubber, (A) about 10 to about 90 phr of cis 1,4-polybutadiene rubber and, correspondingly, about 90 to about 10 phr of styrene/butadiene copolymer rubber, and (B) about 5 to about 15 phr of said LDPE.

### Claim 5 (depends on 1)

The tire of claim 1 where, in the tire tread, the diene rubber-based tread, in its uncured state, is characterized by having an extrudability edge value in a range of about 7 to about 10 and an extrudability surface value in a range of about A to about B according to ASTM Method D-2230, using ASTM die #1 and with results reported according to Rating System B.