GB711375A - Improvements in or relating to polycarboxylates and to hydrocarbon oil compositions - Google Patents

Abstract

A polycarboxylate of formula <FORM:0711375/IV (a)/1> wherein Z is H or an alkyl group of 1-3 C atoms, R is H or Me, Y is an alkyl or alkoxyalkyl group of 2-8 C atoms, X and X1 are H, Me or Et the total number of C atoms in X and X1 being not above 2, and n is 10-50 is made by treating a mono- or dialkylbenzene in which each alkyl group has 1-3 C atoms with an ester of formula CH2=CR COOY in the presence of a polymerization catalyst which liberates free radicles under the conditions of the reaction. Representative of many specified alkylbenzenes are toluene, m-xylene, odiethylbenzene, p-ethyltoluene, cumene, pdipropylbenzene and o-ethylcumene. Representative of many specified alkyl and alkoxyalkyl esters are methyl, tert-butyl, isoamyl, octyl, 2- ethoxyethyl, 4-butoxybutyl and 2- hexyloxyethyl acrylates and methacrylates. Mixed acrylates or methacrylates may be used. Ordinary or elevated temperatures, e.g. up to 125 DEG C., may be used. Reaction times vary from several hours to several days. Up to 10 per cent. of catalyst based on ester may be used 0.1-5 per cent. generally being preferred although quantities of 0.001-1 per cent. are also quoted. Equimolar quantities of alkylbenzene and ester may be used although an excess of the former is preferred, e.g. to yield products, intended as anti-foaming agents for hydrocarbon oils (see Group III), with a 10 per cent. cyclohexanone specific viscosity of 0.5-4.0. Inert diluents, e.g. hexane, may be present. Catalysts specified are peroxygen-type compounds, e.g. benzoyl and stearoyl peroxide, tert-butyl and cumene hydroperoxide, hydrogen peroxide, alkali percarbonates, hydrazine derivatives such as the hydrochloride and dibenzoyl hydrazine and organometallic compounds such as tetraethyl lead. In examples esters are made by reacting toluene with butyl acrylate in the presence of of (1), (2) and (4) benzoyl peroxide and (3) cumene hydroperoxide and with (1), (4) and (8) amyl acrylate in the presence of benzoyl peroxide. Adducts of toluene with propyl acrylate and mixed ethyl and 2- ethylhexyl acrylates are also mentioned. ALSO: A polycarboxylate of formula <FORM:0711375/IV (b)/1> wherein Z is H or an alkyl group of 1-3 C atoms, R is H or Me, Y is an alkyl or alkoxy-alkyl group of 2 to 8 C atoms, X and X1 are H, Me or Et, the total number of C atoms in X and X1 being not above 2, and n is 10-50, is made by treating a mono- or di-alkylbenzene in which each alkyl group has 1-3 C atoms with an ester of formula CH2=CR.COOY in the presence of a polymerization catalyst which liberates free radicles under the conditions of the reaction. Representative of many specified alkylbenzenes are toluene, m-xylene, o-diethylbenzene, p-ethyltoluene, cumene, p-dipropylbenzene and o-ethylcumene. Representative of many specified alkyl and alkoxyalkyl esters are methyl, tert.-butyl, isoamyl, octyl, 2-ethoxyethyl, 4-butoxybutyl and 2-hexyloxyethyl acrylates and methacrylates. Mixed acrylates or methacrylates may be used. Ordinary or elevated temperatures, e.g. up to 125 DEG C., may be used. The reaction time varies from several hours to several days. Up to 10 per cent of catalyst based on ester may be used, 0.1-5 per cent generally being preferred. Quantities of 0.001 -1 per cent may be used. Equimolar quantities of alkylbenzene and ester may be used although an excess of the former is preferred, e.g., to yield products intended as anti-foaming agents for hydrocarbon oils (see Group III), with a 10 per cent cyclohexanone specific viscosity of 0.5-40. An inert diluent, e.g. hexane, may be used. Specified catalysts are peroxygentype compounds, e.g. benzoyl and stearoyl peroxide, tert.-butyl and cumene hydroperoxide, hydrogen peroxide, alkali percarbonates; hydrazine derivatives such as the hydrochloride and dibenzoyl hydrazine and organometallic compounds such as tetraethyl lead. In examples esters are made by reacting toluene with (1) and (4) butyl or amyl acrylate in the presence of benzoyl peroxide; (2) butyl; and (8) amyl acrylate in the presence of benzoyl peroxide; and (3) butyl acrylate in the presence of cumene hydroperoxide. Adducts of toluene with propyl acrylate and mixed ethyl and 2-ethylhexyl acrylates are also mentioned. ALSO: The foam-susceptibility of hydrocarbon oils is decreased by incorporating therewith up to 0.1 per cent. by weight of a polycarboxylate of formula <FORM:0711375/III/1> wherein Z is H or an alkyl group of 1-3 C atoms, R is H or Me, Y is an alkyl or alkoxyalkyl group of 2-8 C atoms, X and X1 are H, Me or Et the total number of C atoms in X and X1 being not above 2, and n is 10-50. The polycarboxylate is made by reacting a mono- or di-alkylbenzene in which each alkyl group has 1-3 C atoms with an ester of formula CH2=CRCOOY in the presence of a polymerization catalyst which liberates free radicles under the conditions of the reaction. Representative of many specified alkylbenzenes are toluene, m-xylene, o-diethylbenzene, p-ethyltoluene, cumene, p-dipropylbenzene and o-ethylcumene. Representative of many specified esters are methyl, tert-butyl, isoamyl, octyl, 2-ethoxyethyl, 4-butoxybutyl and 2-hexyloxyethyl acrylates and methacrylates. Mixed acrylates and methocrylates may be used, e.g. a mixture of ethyl and 2-ethylhexyl acrylates may be reacted with toluene. Catalysts specified are per-oxygen type compounds, hydrazine derivatives and organo-metallic compounds. Inert diluents may be present. For reaction details (see Group IV(b)). Hydrocarbon oil concentrates containing up to 50 per cent. of polycarboxylate may be prepared. Oils mentioned are lubricating oils, Diesel fuels and lubricants and pressure transfer media, e.g. hydraulic oils. Other adjuvants may be present in the oil, e.g. form inducing additives. Additional additives mentioned are metal salts of a cycloaliphatic, aromatic or aromatic-aliphatic compound containing as substituents a salt-forming radicle and a hydrocarbon chain of at least 4 C atoms. The salt-forming group may be OH, COOH, PO4H, PO3H, SH, or SO3H and many metals are specified representative being Ba, Al, Cu, Na, Cd and Mn. Preferred are aluminium and alkaline earth metals. Other additives mentioned are aluminium, calcium or lithium hexadecyl phenate, barium or magnesium salts of sulphated dodecyl phenol, magnesium or strontium salts of an alkyl substituted naphthol the alkyl substituent being derived from wax, the barium salt of oleyl carbonate, barium cetyl phthalate, the calcium salt of wax-substituted phenoxy-phenol, the barium salt of wax-substituted and sulphated hydroxy-diphenyl sulphide, aromatic and alkylaromatic compounds of 5-30 C atoms containing a thiocarbonate group, e.g. of formula <FORM:0711375/III/2> wherein R11 is a chlorine-containing alkyl. aryl or aralkyl radicle of 5-30 C atoms, R1 is an organic ester-forming group and Y1 is S or O at least one Y being S. Many of the latter compounds are specified representative being chlorododecyl ethyl and chlorobenzyl methyl xanthates, trichlorobenzyl ethyl and chloronaphthyl methyl sulphocarbonates, (dichlorophenyl)-ethyl propyl and chlorooctadecyl amyl trithiocarbonates, tetrachlorohexyl p-tolyl and chlorononocosyl ethyl dithiocarbonate and chlorobenzyl dodecyl and chloroamyl benzyl thiocarbonate. Xanthates are generally advantageous especially those of formula <FORM:0711375/III/3> where the alkyl group is of 1-4 C atoms and R11 is as above. Examples 4-8 provide anti-foaming and stability tests on base oils containing 2-50 p.p.m. of amyl or butyl acrylate-toluene adducts with and without 4 per cent. of a barium salt of an alkyl aromatic sulphonic acid containing 22-30 C atoms in the alkyl group. Propyl acrylate adducts are also mentioned in 4.