The Goodyear & Tire Rubber Company

Stanley M Mezynski

Michael B Rodgers

Adel Farhan Halasa

Wen-Liang Hsu

Barry A Matrana

Joel L Cox

Jennifer Lyn Ryba

The invention relates to a truck or bus tire with a rubber tread of cap/base construction where the tread cap is composed of an emulsion polymerization prepared styrene/butadiene copolymer elastomer with a relatively random styrene content (E-SBR-A). Such E-SBR-A, in its uncured state, also has a relatively low Tg. In one aspect, the tire tread's tread cap may also be a blend of elastomers such as cis 1,4-polybutadiene and/or natural rubber together with said E-SBR-A and wherein the tread base elastomer is composed primarily of natural cis 1,4-polyisoprene rubber. In another aspect of the invention, said tread cap has a tread design composed of at least three circumferential continuous ribs designed to be road contacting, said ribs independently separated by continuous, circumferential grooves.

Truck tire with cap/base construction tread

The subject invention discloses a styrene-isoprene-butadiene rubber which is particularly valuable for use in making truck tire treads, said rubber being comprised of repeat units which are derived from about 5 weight percent to about 20 weight percent styrene, from about 7 weight percent to about 35 weight percent isoprene, and from about 55 weight percent to about 88 weight percent 1,3-butadiene, wherein the repeat units derived from styrene, isoprene and 1,3-butadiene are in essentially random order, wherein from about 25% to about 40% of the repeat units derived from the 1,3-butadiene are of the cis-microstructure, wherein from about 40% to about 60% of the repeat units derived from the 1,3-butadiene are of the trans-microstructure, wherein from about 5% to about 25% of the repeat units derived from the 1,3-butadiene are of the vinyl-microstructure, wherein from about 75% to about 90% of the repeat units derived from the isoprene are of the 1,4-microstructure, wherein from about 10% to about 25% of the repeat units derived from the isoprene are of the 3,4-microstructure, wherein the rubber has a glass transition temperature which is within the range of about -90.degree. C. to about -70.degree. C., wherein the rubber has a number average molecular weight which is within the range of about 150,000 to about 400,000, wherein the rubber has a weight average molecular weight of about 300,000 to about 800,000, and wherein the rubber has an inhomogeneity which is within the range of about 0.5 to about 1.5.

Styrene-isoprene-butadiene rubber

Process for preparing styrene-isoprene-butadiene rubber

The subject invention discloses a styrene-butadiene rubber (SBR) which is particularly valuable for use in making truck tire treads, said rubber being comprised of repeat units which are derived from about 10 weight percent to about 20 weight percent styrene and from about 80 weight percent to about 90 weight percent 1,3-butadiene, wherein the repeat units derived from styrene and 1,3-butadiene have a sequence distribution wherein at least about 55% of the styrene repeat units are in blocks of only one styrene repeat unit, wherein at least about 75% of the styrene repeat units are in blocks of 1 or 2 repeat units, and wherein at least about 5% of the styrene repeat units are in blocks of more than 8 repeat units, wherein from about 32% to about 40% of the repeat units derived from the 1,3-butadiene are of the cis-microstructure, wherein from about 50% to about 60% of the repeat units derived from the 1,3-butadiene are of the trans-microstructure, wherein from about 6% to about 15% of the repeat units derived from the 1,3-butadiene are of the vinyl-microstructure, wherein the rubber has a glass transition temperature which is within the range of about -85.degree. C. to about -70.degree. C., wherein the rubber has a number average molecular weight which is within the range of about 150,000 to about 400,000, wherein the rubber has a weight average molecular weight of about 300,000 to about 800,000, and wherein the rubber has an inhomogeneity which is within the range of about 0.5 to about 1.5.

Styrene-butadiene rubber for truck tires

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Mogadore, OH, United States of America

Stanley M Mezynski