Useful rubbery elastomers include natural rubber, synthetic polyisoprene, polybutadiene, polyisobutylene-co-isoprene, neoprene, poly(ethylene-co-propylene), poly(styrene-co-butadiene), poly(styrene-co-isoprene), and poly(styrene-co-isoprene-co-butadiene), poly(isoprene-co-butadiene), poly(ethylene-co-propylene-co-diene), polysulfide rubber, acrylic rubber, urethane rubber, silicone rubber, epichlorohydrin rubber, and mixtures thereof. Other rubbery elastomers may derive from the polymerization of ethylene together with one or more α-olefins and optionally one or more diene monomers. These conjugated diene monomers may be copolymerized with other monomers such as vinyl aromatic monomers. The synthetic elastomers typically derive from the polymerization of conjugated diene monomers. Rubbery elastomers include natural and synthetic elastomers. Aqueous lattices include suspensions of at least one rubbery elastomer. The cement may also be oil extended, which refers to a rubber cement that includes one or more oils, such as aromatic and naphthenic oils, which are typically employed in the rubber industry. The rubbery elastomers may be dissolved or suspended in the organic solvent. Polymer cements include a solution of at least one rubbery elastomer in an organic solvent. The premix is prepared by adding at least one processing aid to a polymer cement or aqueous latex, and subsequently removing the solvent. The vulcanizable rubber compositions, which are useful in preparing tire components and other rubber articles, are prepared by mixing a rubber/processing aid premix with carbon black. DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS Among other advantages, this increased carbon black dispersion allows for the production of tire treads that exhibit improved wear. This invention advantageously improves the dispersion of carbon black within vulcanizable compositions that are compounded in large volumes within large-scale mixing equipment. The present invention also provides a method for increasing the dispersion of carbon black within a carbon-black filled tire component, the method comprising providing a rubber cement or latex comprising at least one rubber, adding at least one processing aid to the rubber cement or latex to form a modified rubber cement or latex, isolating the rubber and at least one processing aid from the solvent to form a premix, and mixing the premix with carbon black.
The present invention further provides a tire tread prepared by a method comprising preparing a vulcanizable composition of matter by providing a rubber cement or latex comprising at least one rubber, adding at least one processing aid to the rubber cement or latex to form a modified rubber cement or latex, isolating the rubber and at least one processing aid to form a premix, mixing the premix with carbon black, shaping the vulcanizable composition of matter into a green tire tread, and curing the tire tread. In general the present invention provides a method for forming a vulcanizable composition of matter, the method comprising providing a polymer cement or latex comprising at least one rubber, adding at least one processing aid to the cement or latex to form a modified rubber cement or latex, isolating the rubber and at least one processing aid to form a premix, and mixing the premix with carbon black. This is especially true where a large volume of rubber is compounded within a large-scale mixing apparatus. During mixing, processing aids have been added to improve the degree of carbon black dispersion.ĭespite the use of these conventional processing aides, further improvement in carbon black dispersion is desired. For example, higher dispersion results in increased abrasion resistance.Ĭarbon black is typically added to these rubber compositions during compounding, which is a process that includes mixing of rubber, filler, and other compound components. The degree of carbon black dispersion within these compositions ultimately impacts the properties of the tire or other rubber articles. BACKGROUND OF THE INVENTIONĬarbon black is used as a filler within vulcanizable rubber compositions of matter that are used to make tire components and other rubber articles. This invention relates to a process for improving carbon black dispersion within carbon black-filled rubber compositions. 13, 2001, now abandoned which is incorporated herein by reference. This application is a continuation of U.S.
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