Published Year: 1964

This invention is for improvements in or relating to the stabilisation of natural rubber and is concerned with the treatment of rubber latex to produce a rubber which has improved storage properties. Research has indicated that + the hardening of unvulcanised NR during storage results from crosslinking via oxygenated functional groups, such as carbonyl or carboxyl. By adding a reactive derivative of ammonia, of the general formula XNH2, where X is a hydroxy or hydroxyalkyl group,+ or aromatic nucleus free from any basic group or basic substituent. The above mentioned ammonia derivative added to the latex is preferably between 0.1% and 5% by weight of the rubber solids in the latex. In examples, hydroxylamine, naphthylamine, and + ethanolamine were used.