Patent GB-924332-A (GB)
Title: Polynuclear phenolic antioxidants and their applications
IPC: C07C37/16
Filed: 1961-07-10
Abstract: As anti-oxidants for gasoline, kerosene, furnace oils, mineral lubricating oils and greases, use is made of polynuclear phenols in which an aromatic hydrocarbon group having condensed benzene nuclei is linked to one or more 3, 5-dialkyl-4-hydroxybenzyl substituents attached directly to the ring system.  The specified products include 9, 10-bis (3, 5-di-tert.-butyl-4-hydroxybenzyl) anthracene, 1, 4-bis(3, 5-diisopropyl-4-hydroxybenzyl) naphthalene, alpha-3, 5-diisopropyl-4-hydroxybenzyl-naphthalene, 1-methyl-3 (3-methyl-5-tert.-butyl-4-hydroxybenzyl)naphthalene, 1,4,5,8- tetra(3,5-di-tert. butyl-4-hydroxybenzyl) naphthalene, 9,10-bis(3-methyl-5-tert.-hexyl-4-hydroxybenzyl) phenanthrene, 1,4,5,8,9,10-hexa (3,5-diisopropyl-4-hydroxybenzyl) anthracene, and 5, 6, 11, 12-tetra (3,5-di-tert.-butyl-4-hydroxybenzyl) naphthacene. Products derived from chrysene, pyrene, benzanthracene, pentacene, dibenzanthracene and coronene are also specified.  A synergistic effort is produced if the antioxidants described above are used in association with sulphur compounds of the following types.  (1) Compounds of the type R1-Sx-R2, where X is a whole number and R1 and R2 are similar or dissimilar organic groups bound to Sx by means of carbon atoms, e.g. compounds of the foumula <FORM:0924332/III/1> where R and R1 are similar or dissimilar hydrocarbon groups of 6-20 carbon atoms and n is 1-6, e.g. dilaurylthio-dipropionate, or sulphides of the types R1-CH2-CH2-Sx-R2 or R1-CH2-CH2- Sx-CH2-CH2 -R2, where X is a whole number and R1 and R2 are similar or dissimilar aliphatic or aromatic groups.  (2) Compounds of the general formula <FORM:0924332/III/2> where M is a metal of Group II of the Periodic System and R1 and R2 are hydrocarbon groups of 1-6 carbon atoms.  (3) Trialkyl trithiophosphites having 6-20 carbon atoms in the alkyl groups.  (4) Polymeric products su:h as polyalkoxyalkyl sulphides (-R1-O-R1-S-)x,polyalkoxy=alkoxyalkyl sulphides (-R1-O-R2-O-R1-S-)x and polyhydroxyalkyl sulphides (-R1 (OH)-S-)x, such products being obtainable by reacting an unsaturated ether, e.g. diallyl ether, with hydrogen sulphide.ALSO:As anti-oxidants for polyolefines, synthetic rubbers and liquid ethylenically unsaturated monomers, use is made of polynuclear phenols in which an aromatic hydrocarbon group having condensed benzene nuclei is linked to a 3,5-dialkyl-4-hydroxybenzyl substituent attached directly to the ring system.  The aromatic hydrocarbon group preferably contains 2-6 benzene nuclei and may be substituted with alkyl groups preferably having not more than 4 carbon atoms.  The alkyl groups in the 3,5-dialkyl-4-hydroxybenzyl residue preferably contain not more than 8 carbon atoms.  The specified products includes 9,10-bis(3,5-di-tert.-butyl-4-hydroxybenzyl) anthracene, 1,4-bis(3,5-diisopropyl-4-hydroxybenzyl) naphthalene, alpha - 3,5 - diisopropyl - 4 - hydroxybenzyl - naphthalene, 1-methyl-3(3-methyl-5-tert.-butyl-4-hydroxybenzyl) naphthalene, 1,4,5,8-tetra(3,5-ditert.-butyl-4-hydroxybenzyl) naphthalene, 9,10-bis(3-methyl-5-tert.-hexyl-4-hydroxybenzyl) phenanthrene, 1,4,5,8,9,10-hexa(3,5-diisopropyl-4-hydroxybenzyl) anthracene, and 5,6,11,12-tetra-(3,5-di-tert.-butyl-4-hydroxybenzyl) naphthacene. Products derived from chrysene, pyrene, benzanthracene, pentacene, dibenzanthracene and coronene are also specified.  A number of materials to which the phenols may be applied are specified.  The proportion of antioxidant may be 0,0001-10% by weight.  A synergistic effect is produced if the antioxidants described above are used in association with sulphur compounds of the following types.  (1) Compounds of the type R1-Sx-R2, where X is a whole number and R1 and R2 are similar or dissimilar organic groups bound to Sx by means of carbon atoms, e.g. compounds of the formula <FORM:0924332/IV(a)/1> where R and R1 are similar or dissimilar hydro-carbon groups of 6-20 carbon atoms and n is 1-6, e.g. dilaurylthiodipropionate, or sulphides of the types R1-CH2-CH2-Sx-R2 or R1-CH2-CH2-Sx-CH2-CH2 -R2, where X is a whole number and R1 and R2 are similar or dissimilar aliphatic or aromatic groups.  (2) Compounds of the general formula <FORM:0924332/IV(a)/2> where M is a metal of Group II of the periodic system and R1 and R2 are hydrocarbon groups of 1-6 carbon atoms.  (3) Trialkyl trithiophosphites having 6-20 carbon atoms in the alkyl groups.  (4) Polymeric products such as polyalkoxyalkyl sulphides (-R1-O-R1-S-)x, polyalkoxyalkoxyalkyl sulphides (-R1-O-R2-O-R1-S-)x and polyhydroxyalkyl sulphides (-R1(OH)-S-)x, such products being obtainable by reacting an unsaturated ether, e.g. diallyl ether, with hydrogen sulphide.  Rubber and plastic compositions treated according to the invention may contain pigments, fillers, antiozonants and curing agents.ALSO:The invention comprises polynuclear phenols in which an aromatic hydrocarbon group having condensed benzene nuclei is linked to a 3,5-dialkyl-4-hydroxybenzyl substituent attached directly to the ring system.  The aromatic hydrocarbon group preferably contains 2-6 benzene nuclei and may be substituted with alkyl groups preferably having not more than 4 carbon atmos.  The alkyl groups in the 3,5-dialkyl-4-hydroxybenzyl residue preferably contain not more than 8 carbon atoms.  The products may be prepared by condensing an aromatic hydrocarbon having condensed benzene nuclei with a 3,5-dialkyl-4-hydroxybenzyl alcohol in the presence of a Friedel-Crafts catalyst or sulphuric acid, preferably in the presence of a dehydrating agent, e.g. phosphorus pentoxide, and optionally in the presence of an inert solvent, a number of which are specified. The reaction may be effected at -15-100 DEG  C., preferably at atmospheric pressure.  The specified Friedel-Crafts catalysts include zirconium tetrachloride, tantalum pentachloride, beryllium chloride, titanium tetrachloride and tin tetrachloride.  The specified products include 9,10-bis(3,5-di-tert.-butyl-4-hydroxybenzyl)anthracene, 1,4-bis(3,5- diisoprophyl-4- hydroxybenzyl-naphthalene, alpha-3,5-diisopropyl- 4-hydroxybenzyl-naphthalene, 1-methyl- 3(3-methyl- 5-tert.-butyl- 4-hydroxybenzyl)-naphthalene, 1,4,58- tetra(3,5-di-tert.-butyl- 4-hydroxybenzyl)naphthalene, 9,10-bis(3-methyl- 5-tert.-hexyl- 4-hydroxybenzyl) phenanthrene, 1,4,5,8,9,10- hexa(3,5-diisopropyl-4-hydroxybenzyl)anthracene, and 5,6,11, 12-tetra(3,5- di-tert.- butyl-4- hydroxybenzyl) naphthacene. Products derived from chrysene, pyrene, benzanthracene, pentacene, dibenzanthracene and coronene are also specified.  The products are useful as antioxidants and for protecting materials against thermal and ultra-violet degradation. Materials to which the products may be applied include polyolefines, synthetic rubbers and liquid ethylenically unsaturated monomers, a number of each of which are specified, and also natural rubber, gasoline, kerosine, furnace oils, lubricating oils and greases.  A synergistic effect is produced if the antioxidants described above are used in association with certain sulphur compounds (see Groups III and IV(a)).