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US 5,558,325 AGranted
Play balls or pressureless tennis balls
AssigneeGenCorp Inc.
InventorsI. Glen Hargis, Richard A. Miranda, John A. Wilson, Oon H. Yeoh
Life of this patent
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AssigneeGenCorp Inc.
InventorsI. Glen Hargis, Richard A. Miranda, John A. Wilson, Oon H. Yeoh
Estimating the term…
A hollow rubber play ball is disclosed that uses a combination two or more fillers to produce desirable playing properties in a tennis ball as specified by the International Lawn Tennis Federation (ITF). The preferred play ball is a pressureless tennis ball. The specific fillers disclosed are mineral type particulate reinforcing fillers such as silicas and carbon black, polymeric fillers such as cellulose, a reaction product of grafting polyethylene with cellulose, and ethylene-vinyl acetate copolymers. These fillers can also have surface treatments to enhance the elastomer-filler interaction. Another reinforcing filler that can be introduced with the rubber components is the non-rubber constituents in skim rubber that serve to increase the modulus of a compounded rubber.
A play ball comprising:
In a tennis ball comprising a hollow sphere which is comprised of a crosslinked blend of one or more rubbers and reinforcing filler, the improvement comprising the inclusion of a grafted product of the reaction of low density polyethylene with cellulose in the presence of a free-radical source and wherein said grafted reaction product is present in amounts from 10 to 50 phr.
In a tennis ball comprising a hollow sphere of a blend of one or more crosslinked rubbers and reinforcing fillers, the improvement wherein said fillers comprise in combination, an ethylene-vinyl acetate copolymer, having from about 1 to 10 weight percent vinyl acetate and from 90 to 99 weight percent ethylene, and a particulate reinforcing filler selected from carbon black or silica or combinations thereof which are blended into said one or more rubbers before they are crosslinked.
In rubber ball halves including one or more rubbers, fillers, and curatives wherein the improvement comprises having from 5 to 50 phr 6f a filler, said filler being a reaction product of low density polyethylene, cellulose fiber, and a free radical initiator reacted at from about 90.degree. to about 190.degree. C. which forms cellulose grafted with said polyethylene.
A play ball comprising:
Dependencies are inferred from the claim text.