Patent GB-927179-A (GB)
Title: Asymmetric methylene-bis-phenols and their use as anti-oxidants
IPC: C08K5/13
Filed: 1960-04-01
Abstract: Lubricating oils, liquid fuels, vegetable oils and fats and waxes are stabilized against oxidation by the addition of a compound of formula <FORM:0927179/III/1> <FORM:0927179/III/2> wherein A and B are hydrogen atoms or alkyl groups having up to 9 carbon atoms and at least one of A or B is a tertiary alkyl group having 4-9 carbon atoms and is positioned ortho to one of the hydroxyl groups and when the hydroxyl groups are both para to the methylene bridge A and B are such that the molecule is not symmetrical (see Group IV(b)).  The compounds are used in admixture with the corresponding symmetrical bis-phenols. Specified lubricating oils include mineral lubricating oils and synthetic di-ester oils, examples being given.  Specified liquid fuels are gasoline, jet fuel, kerosine and fuel oil.  The lubricants and fuels may contain the usual additives.  Specified vegetable oils and fats include lard, beef tallow, fish oils, castor oil, soybean oil, rapeseed oil, coconut oil, olive oil, palm oil, corn oil, sesame oil, peanut oil, babassu oil, citrus oils and cotton seed oil.ALSO:Natural and synthetic rubbers and synthetic polymers are stabilized against oxidation by the addition of a compound of formulae <FORM:0927179/IV(a)/1> <FORM:0927179/IV(a)/2> wherein A and B are hydrogen atoms or alkyl groups having up to 9 carbon atoms and at least one of A or B is a tertiary alkyl group having 4-9 carbon atoms and is in o-position to one of the hydroxyl groups and when the hydroxyl groups are both para to the methylene bridge A and B are such that the molecule is not symmetrical (see Group IV(b)).  The compounds are used in admixture with corresponding symmetrical bis-phenols.  Specified synthetic rubbers include polybutadiene, methyl and butyl rubbers, GR-S and GR-N, piperylene rubber and dimethylbutadiene rubber.  Preferred polymers are those obtained by polymerization of mono-ethylenically unsaturated monomers such as ethylene, propylene, butylene and isobutylene.  In examples: (1) polyethylene is admixed with (3,5-di-tert-butyl-4-hydroxyphenyl)-(31, 51-dimethyl- or -diisopropyl- or -di-tert-butyl- or 31-methyl-51-tert-butyl-41-hy droxyphenyl)-methane; (2) polypropylene is mixed with a mixture of bis-phenols containing (3,5-di-tert-butyl-4-hydroxyphenyl) - (31-tert-butyl-21- or -4-hydroxyphenyl)-methane as major components; (3) polyisobutylene is mixed with a mixture of bis-phenols containing (3,5-di-tert-butyl-4-hydroxyphenyl) - (31-methyl-51-tert-butyl-41-hydroxyphenyl) -methane; (4) (3-methyl-5-tert-octyl-4-hydroxyphenyl)- (31, 51-di-tert-butyl-4-hydroxyphenyl)-methane is mixed with a rubber batch containing GR-S rubber, zinc propionate stearate, carbon black, road tar, sulphur and mercaptobenzothiazole and the mixture is cured; (5) a mixture of bis-phenols containing (3,5-di-tert-butyl-4-hydroxyphenyl)-(31 - methyl - 51 - tert - butyl - 41 - hydroxyphenyl)-methane is mixed with crepe, natural rubber, wax, ultramarine dye, zinc oxide, titanium dioxide, sulphur, stearic acid, benzothiazolyl disulphide and an amine activator and the mixture vulcanized.ALSO:The invention comprises methylene-bisphenols of formula <FORM:0927179/IV(a)/1> <FORM:0927179/IV(a)/2> wherein A and B are hydrogen atoms or alkyl groups having up to 9 carbon atoms and wherein at least one A or B is a tertiary alkyl group having 4-9 carbon atoms and is positioned ortho to one of the hydroxyl groups and when the hydroxyl groups are both para to the methylene bridge A and B are such that the molecule is not symmetrical; and the compounds (3,5-di-tertbutyl- 4-hydroxyphenyl) - (31-tert-butyl-41-hydroxyphenyl)-methane and (3,5-di-tert-butyl-4-hydroxyphenyl) - (31-methyl- 51-tertbutyl-41-hydroxyphenyl) -methane.  The compounds are prepared, in admixture with symmetrical methylene-bis-phenols, by reacting a mixture of suitably substituted phenols with formaldehyde and an aliphatic alcohol under basic conditions.  The bis-phenols are used as anti-oxidants in oils and fats (see Group III), rubbers and synthetic polymers (see Group IV(a)).  In an example a solution in p ethanol of 2-methyl-6-tert.-butyl-phenol and 2,6-di-tert-butyl-phenol is mixed with formaldehyde and aqueous sodium hydroxide and refluxed under nitrogen to give (3,5-di-tert.-butyl-4-hydroxyphenyl) - (31-methyl- 51-tertbutyl-41-hydroxyphenyl) -methane in admixture with symmetrical bis-phenols, benzyl ethers and benzyl alcohols.  In further examples mixtures of (a) 2,6-di-tert-butylphenol and 2-tert.-butylphenol or 2-methyl- 6-tert-butyl-phenol and (b) 6-tert-amyl-p-cresol and 2-methyl-6-tert.- butylphenol are similarly reacted.ALSO:Oxidative deterioration of animal and vegetable oils and fats, e.g. butter, lard, beef tallow and cod liver oil, and of the fat in foods such as potato chips, fried fish, doughnuts, crackers, pastries and cakes, is prevented by asymmetrical bisphenols: <FORM:0927179/VI/1> <FORM:0927179/VI/2> wherein A and B are hydrogen atoms or alkyl groups having up to 9 carbon atoms and at least one of A or B is a tertiary alkyl group having 4-9 carbon atoms and is positioned ortho to one of the hydroxyl groups and, when the hydroxyl groups are both para to the methylene bridge A and B are such that the molecule is not symmetrical (see Group IV (b)).  The compounds are used in admixture with the corresponding symmetrical bis-phenols.