Monoesters of rosin acid
AssigneeThe Goodyear Tire & Rubber Company
InventorsLawson G. Wideman, Paul H. Sandstrom
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Abstract
The present invention relates to monoesters of rosin acids which are useful as a total or partial replacement for extender or processing oil in rubber formulations. Addition of these monoesters of rosin acid improve the modulus and tear of the vulcanizate. The monoesters are of the formula: ##STR1## wherein R.sup.1 and R.sup.2 are the same or different hydrocarbon radicals selected from the group consisting of saturated alkyl and cycloalkyl radicals containing 3 to 20 carbon atoms, aryl radicals containing 6 carbon atoms and aralkyl radicals containing 7 to 20 carbon atoms.
Claims12
A process for improving the physical properties of rubber compositions which comprises (i) admixing a rubber selected from the group consisting of natural rubber, homopolymers of conjugated diolefins, copolymers of conjugated diolefins and ethylenically unsaturated monomers or mixtures thereof with (a) a monoester of rosin acid of the formula:
- ##STR7## wherein R.sup.1 and R.sup.2 are the same or different hydrocarbon radicals selected from the group consisting of saturated alkyl and cycloalkyl radicals containing 3 to 20 carbon atoms, aryl radicals containing 6 carbon atoms and aralkyl radicals containing 7 to 20 carbon atoms and (b) from 0.5 to 10 phr of a methylene donor;
- and (ii) vulcanizing the rubber composition.
Dependencies are inferred from the claim text.