Patent GB-719241-A (GB)
Title: Manufacture of natural and synthetic rubber articles
Inventor: LAMBERT ARTHUR
IPC: C08L21/00
Filed: 1952-03-11
Abstract: Synthetic rubbers and their latices are stabilized by the addition of a 2:21-dihydroxy-5:51-dimethyl-diphenyl methane, to the 3 position of which is attached the tertiary carbon atom of a tertiary alkyl group of 4-8 carbon atoms, and the 31 position a cyclohexyl-bornyl, iso-bornyl or non-tertiary alkyl group of 1-5 carbon atoms; or a normal or basic aluminium, barium, calcium, magnesium strontium or zinc salt of the above compounds.  The synthetic rubbers may be polymers of butadiene 1:3 and 2-chloro-butadiene 1:3, and copolymers of such monomers with acrylonitrile, styrene or methyl methacrylate. In Examples, specified antixoidants are :-2:21 - dihydroxy - 3 - tert - butyl - 31:5:51 - trimethyl diphenyl methane, and its magnesium salt, 2:21 - dihydroxy - 3 - tert. - butyl - 31 - sec - butyl - 5:51 - dimethyl methane, 2:21 - dihydroxy - 3 - (1:1:3:3 - tetramethylbutyl) - 31:5: 51-trimethyl diphenylmethane, 2:21-dihydroxy-3-tert-butyl - 31 - isobornyl - 5:51 - dimethyl phenylmethane, and 2:21-dihydroxy-3-tert-butyl 31 - cyclo - hexyl - 5:51 - dimethyl diphenyl methane.  The antioxidant may be used in sponge rubber mixes made from a mixture of pale crepe, butadiene-styrene (75:25) and butadiene-styrene (25:75).  Other substances which may be added to the mixes are zinc oxide, blanc fixe, stearic acid, sulphur, diphenylguanidine, titanium dioxide, zinc diethyldithiocarbamate, lithopone, light magnesium carbonate, petroleum jelly, tetramethyl thiuram monosulphide, dinitroso-pentamethylene tetramine, calcium silicate, china clay and oleic acid.  Specification 719,101, [Group IV (b)], is referred to.ALSO:Natural and synthetic rubber are stabilized by the addition of a 2 : 21-dihydroxy-5 : 51-dimethyl-diphenyl methane, to the 3 position of which is attached the tertiary carbon atom of a tertiary alkyl group of 4-8 carbon atoms, and to the 31 position a cyclo hexyl bornyl, iso bornyl or non-tertiary alkyl group of 1-5 carbon atoms; or a normal or basic aluminium, barium, calcium, magnesium, strontium or zinc salt of the above compounds. The synthetic rubbers may be polymers of butadiene 1 : 3 and 2-chlorobutadiene 1-3, and copolymers of such monomers with acrylonitrile, styrene or methyl methacrylate mers of butadiene 1 : 3 and 2-chlorobutadiene In examples, specified antioxidants are:-2 : 21 dihydroxy-3-tert. butyl 31 : 5 : 51 trimethyl diphenyl methane, and its magnesium salt, 2 : 21 dihydroxy 3-tert. butyl 31 sec butyl 5 : 51 dimethyl methane 2 : 21-dihydroxy-3-(1 : 1 : 3 : 3-tetramethylbutyl 31 : 5 : 51-trimethyl diphenyl-methane, 2 : 21 dihydroxy-3-tert.-butyl 31 isobornyl-5 : 51 dimethylphenylmethane, and 2 : 21-dihydroxy 3-tert. butyl 31 cyclo hexyl 5 : 51 dimethyl diphenylmethane.  The antioxidant may be used in sponge rubber mixes made from pale crepe natural rubber and from a mixture of pale crepe, butadiene-styrene (72 : 25) and butadiene-styrene (25 : 75). Other substances which may be added to the mixes are zinc oxide, blanc fixe, stearic acid, sulphur, diphenyl guanidine, titanium, dioxide, zinc diethyldithiocarbonate, lithopone, light magnesium carbamate, petroleum jelly, tetramethyl thiuram monosulphide, dinitrosopentamethylene tetramine, calcium silicate, china clay and oleic acid.  Specification 719,101, [Group IV (b)], is referred to.