Patent GB-728291-A (GB)
Title: Manufacture of natural and synthetic rubbers and rubber articles
Inventor: LAMBERT ARTHUR
IPC: C07C37/20
Filed: 1951-12-19
Abstract: Synthetic rubber is stabilized by incorporating therein a bis-(2-hydroxy-3-alpha-alkyl-cycloalkyl - 5 - methylphenyl) - methane in which the cyclo-alkyl group is a cyclo-pentyl, methyl-cyclo-pentyl, cyclo-hexyl or methyl-cyclo-hexyl group and the alkyl substituent has not more than 4 carbon atoms and is attached to the alpha-carbon of the cyclo-alkyl group.  These compounds may be made by the methods described in Specification 728,290, [Group IV (b)].  The normal and basic aluminium, barium, calcium, magnesium, strontium, and zinc salts may also be used. The synthetic rubbers may be polymers of butadiene-1,3, isobutene, or 2-chloro-butadiene-1,3, or copolymers of these substances with acrylonitrile, styrene, or methyl methacrylate.ALSO:Bis - (2 - hydroxy - 3 - alpha - alkyl - cycloalkyl - 5 - methylphenyl) - methanes in which the cyclo alkyl group is a cyclo-pentyl, methyl cyclo pentyl, cyclo hexyl or methyl cyclo hexyl group and the alkyl substituent has not more than 4 carbon atoms and is attached to the alpha-carbon of the cyclo alkyl group, may be made by the methods described in Specification 728,290. These compounds may be used as stabilisers for natural and synthetic rubber (see Groups IV (a) and V).  The normal and basic aluminium, barium, calcium, magnesium strontium and zinc salts may also be used. Specified compounds are:-bis - (2 - hydroxy - 3 - alphamethylcyclohexyl 5 - methylphenyl) - methane, bis - (2 - hydroxy - 3 - alpha - ethyl cyclohexyl-5 - methyl - phenyl) methane, bis - (2 - hydroxy-3 - alpha gamma - dimethyl cyclohexyl - 5-methylphenyl) - methane, bis - (2 - hydroxy 3-alpha - n - butyl cyclohexyl - 5 - methylphenyl)-methane, bis - (2 - hydroxy - 3 - alpha gamma-dimethyl cyclohexyl - 5 - methylphenyl - methane, and the magnesium salt of bis-(2-hydroxy-3 alpha methyl cyclohexyl-5 methylphenyl) methane.ALSO:Natural or synthetic rubber is stabilized by incorporating therein a bis - (2-hydroxy-3-alpha-alkyl-cycloalkyl-5-methylphenyl) - methane in which the cyclo alkyl group is a cyclo-pentyl, methyl cyclo pentyl, cyclo hexyl or methyl cyclo hexyl group and the alkyl substituent has not more than 4 carbon atoms and is attached to the alpha-carbon of the cyclo alkyl group.  These compounds may be made by the methods described in Specification 728,290, [Group IV (b)].  The normal and basic aluminium, barium, calcium, magnesium, strontium, and zinc salts may also be used.  In examples a mix is made up from pale crepe natural rubber, zinc oxide, blanc fixe, stearic acid, sulphur and either diphenylguanidine or titanium dioxide and zinc diethyldithiocarbamate and then as antioxident one of the following is added:-bis - (2-hydroxy-3-alpha-methylcyclohexyl 5-methylphenyl) - methane, bis - (2. - hydroxy-3-alpha-ethyl cyclohexyl-5-methyl-phenyl) methane, bis - (2 - hydroxy - 3 - alpha gamma - dimethyl cyclohexyl - 5 - methylphenyl) - methane, bis - (2 - hydroxy 3 - alpha - m. - butyl cyclohexyl - 5 methylphenyl) - methane, bis - (2 - hydroxy - 3 - alpha gamma - dimethyl cyclohexyl - 5 - methylphenyl) - methane, and the magnesium salt of bis - (2 - hydroxy - 3 alpha methyl cyclohexyl - 5 methylphenyl) methane.