This disclosure relates to a process for preparing long-chain hydrocarbon substituted ureas by reacting a long chain fatty acid N-chloramide in isopropanol and/or tertiary butanol with an aliphatic or araliphatic primary or secondary amine in the presence of an alkali or alkaline earth hydroxide at a temperature of from 20.degree. to 100.degree. C. The process of this disclosure is particularly useful in preparing long-chain hydrocarbon substituted ureas wherein one of the aliphatic hydrocarbon substituents contains one or more hydroxyl and/or carboxyl groups, as well as the salts of such substituted ureas.
The present invention relates to silica-filled rubber compositions containing dialkyleneamide polysulfides of the formula
where R1 is independently selected from alkylene groups having 1 to 18 carbon atoms and x is an integer of from 2 to 7.