Patent GB-898028-A (GB)
Title: Phenolic compounds
IPC: C10M135/30
Filed: 1959-03-05
Abstract: Thio-bis-phenols of formula <FORM:0898028/III/1> wherein R is an alkyl group branched on the alpha carbon atom and having 3 or 4 carbon atoms, and R1 is an alkoxy or alkyl group having 1 to 4 carbon atoms, and x is 1, 2, or 3, are used as anti-oxidants and incorporated in organic substances normally tending to deteriorate in presence of air, oxygen, or ozone, such as gasoline, kerosene, fuel oil, lubricating oils, turbine-, hydraulic-, and transformer-oils, waxes, soaps, greases, organometallic compositions such as tetraethyl-lead antiknock fluids; petroleum wax, paraffin wax, microcrystalline wax; edible fats and oils, e.g. linseed, codliver, castor, soybean, rapeseed, coconut, olive, palm, corn, sesame, peanut, and babassu oil, and butter, lard, and beef tallow. Proportions of up to about 5% of the thio-bis-phenol may be incorporated in the oxygen sensitive material.  In examples, 4,41-thio-bis(2-methyl-6-tert.-butyl phenol) is incorporated in gasoline; the corresponding 2,6-di-tert.-butyl compound is incorporated in diesel fuel; the 2,6-di-isopropyl compound is incorporated in an antiknock fluid composition which is to be used as an additive to gasoline and which contains tetraethyl lead, ethylene dibromide, and ethylene dichloride; 4,41-thio-bis(2-methyl-6-tert.-butylphenol) is added to a crankcase lubricating oil; the corresponding p  2,6-di-tert.-butyl compound is added to a solvent refined neutral oil; 4,41-thio-bis(2-methyl-6-tert.-butylphenol) is incorporated in lard; the corresponding 2-iso-propyl-6-tert.-butyl compound is incorporated in olive oil; and the 2-methyl-6-tert.-butyl compound is incorporated in dioctyl sebacate.  Reference has been directed by the Comptroller to Specification 845,608.ALSO:Compounds of formula <FORM:0898028/IV (a)/14> wherein R is an alkyl group branched on the alpha carbon atom and having 3 or 4 carbon atoms, and R1 is an alkoxy or alkyl group having 1-4 carbon atoms, land x is 1, 2, or 3, are used as anti-oxidants for organic substances normally tending to deteriorate in presence of air, oxygen, or ozone, such as natural and synthetic rubbers, and polymerized monoolefines.  Specified substances which may be stabilized include homopolymers and copolymers of ethylene, propylene, butylene, and isobutylene; polybutadiene, methyl rubber, polybutene rubber, natural rubber, butyl rubber, GR-S and GR-N rubbers, piperylene rubber, and dimethyl butadiene rubber.  In examples, polyethylene and polyisobutylene are stabilized by incorporating 0,01 to 5% of 4,41-thio-bis(2-methyl-6-tert.-butyl phenol) or the corresponding 2,6-di-tert.-butyl, 2-n-propyl-6-tert.-butyl, 2-isopropyl-6-sec.-butyl, or similar compounds.  The polyalkylene compounds may contain further additives such as carbon black or other pigments, elastomers, polyvinyl compounds, carboxylic esters, urea-aldehyde condensation products, flame retarding agents such as antimony trioxide and chlorinated hydrocarbons. Other examples describe the addition of the thio-bis-phenolic compounds to a composition comprising GR-S rubber, zinc propionatestearate, carbon black, road tar, sulphur, and mercaptobenzothiazole; to raw butyl rubber prepared by copolymerization of isobutylene with 10% of isoprene; and to natural rubber.  Reference has been directed by the Comptroller to Specification 845,608.ALSO:The invention comprises thio-bis-phenols of formula <FORM:0898028/IV (b)/1> wherein R is an alkyl group branched on the alpha carbon atom and having 3 or 4 carbon atoms, and R1 is an alkoxy group having 1 to 4 carbon atoms or an alkyl group having 1 to 4 carbon atoms, and X is 1, 2, or 3.  These compounds may be obtained by reacting a phenol of the formula <FORM:0898028/IV (b)/2> with sulphur mono- or di-chloride.  When a compound having 2 or 3 sulphur atoms bridging the phenolic rings is desired, the product of the sulphur chloride/phenol reaction may be further reacted with free sulphur.  In the case of 4,41-thio-bis(2,6-di-tert-butyphenol), and alkali metal salt (e.g. the sodium salt) of the parent phenol may be reacted with sulphur dichloride.  Specified compounds of the general formula include 4, 41 - thio - bis (2 - methyl - 6 - isopropylphenol), 4, 41 - thio - bis (2 - n - butoxy - 6 - tert - butylphenol) 4, 41 - thio - bis (2 - ethyl - 6 - sec - butylphenol), and 4,41-trithio-bis(2-methyl-6-tert-butylphenol).  In an example, a solution of sulphur dichloride in petroleum ether is added slowly in two portions to a solution of 2,6-di-tert-butylphenol in pet. ether at 20 DEG C.-25 DEG C., the mixture being heated to reflux and then cooled between completion of addition of the first portion and addition of the second portion. The mixture is again heated to reflux and subsequently 4,41-thio-bis(2,6-di-tert-butylphenol) is isolated by fractional crystallisation from methanol solution, and the trithio compound is obtained as a further fraction.  The compounds may be used as antioxidants and incorporated in organic compounds normally tending to deteriorate in the presence of air, oxygen or ozone.  Thus they may be incorporated in liquid hydrocarbon fuels, lubricating oils, waxes, soaps, greases, plastics, organometallic anti-knock compositions, natural rubber, synthetic hydrocatbon polymers, edible oils and fats, and dioctyl sebacate.  Reference has been directed by the Comptroller to Specification 845,608.ALSO:Butter and other edible fats are protected against oxidative deterioration leading to rancidity by incorporating in them a small proportion e.g. 0,01-0,1% of a thio-bisphenolic compound of formula <FORM:0898028/I/1> wherein R is an alkyl group branched on the alpha carbon atom and having 3 or 4 carbon atoms, R1 is an alkoxy or alkyl group of 1 to 4 carbon atoms, and X is 1, 2, or 3.  Examples of specified compounds having the stated general formula are 4, 41-thio-bis (2, 6-di-tert-butyl phenol), 4, 41-thio-bis (2-n-butoxy-6-tert butyl phenol), and 4, 41-trithio-bis (2-methyl-6-tert-butyl phenol).  Reference has been directed by the Comptroller to Specification 845,608.ALSO:Cod-liver oil is protected against oxidative deterioration leading to rancidity by incorporating a small proportion e.g. p  0.01-0.1% of a thio-bis-phenolic compound of formula <FORM:0898028/VI/1> wherein R is an alkyl group branched on the alpha carbon atom and having 3 or 4 carbon atoms, R1 is an alkyl or alkoxy group of 1 to 4 carbon atoms, and X is 1, 2, or 3.  Examples of specified compounds of the stated general formula are 4,41-thio-bis (2,6-di-tert-butyl phenol), 4,41 - dithio - bis (2 - n - propyl - 6 - tert-butyl phenol), and 4,41-thiobis (2-methoxy-6-sec.-butyl phenol).  Reference has been directed by the Comptroller to Specification 845,608.