Patent GB-816580-A (GB)
Title: Lubricant composition
IPC: C10M157/00
Filed: 1955-12-30
Abstract: A lubricating composition suitable for use in internal-combustion engines comprises a major proportion of a lubricating oil and a minor proportion of an oil-soluble mixture of (A) the copolymer of at least one monomer chosen from (1) an aliphatic monocarboxylic acid ester of an unsaturated alcohol, the aliphatic monocarboxylic acid containing up to 30 carbon atoms and the unsaturated alcohol being an a - or b -unsaturated alcohol containing up to 20 carbon atoms; (2) a 1-olefin containing 2-30 carbon atoms; and (3) a vinyl or allyl alkyl or cycloalkyl ether or homologue thereof containing 1-30 carbon atoms in the alkyl or cycloalkyl group, with a monomer chosen from maleic anhydride and an alkyl, cycloalkyl, aryl, alkaryl or aralkyl a ,a 1- or a -substituted maleic anhydride containing up to 20 carbon atoms, the molar ratio of these monomers being from 0.5 : 1.5 to 1.5 : 0.5 and (B) another copolymer of (i) maleic anhydride or an alkyl, cycloalkyl, aryl, alkaryl or aralkyl a ,a 1- or a -substituted maleic anhydride containing up to 20 carbon atoms with (ii) an olefinically unsaturated oil-solubilizing monomer having an aliphatic or cycloaliphatic hydrocarbon group containing 4-30 carbon atoms, and optionally with (iii) an aliphatic monocarboxylic acid ester of an unsaturated alcohol, the aliphatic monocarboxylic acid containing up to 30 carbon atoms and the unsaturated alcohol being an a - or b -unsaturated alcohol containing up to 20 carbon atoms, at least one of copolymers (A) and (B) being partially esterified with a polyalkylene glycol or a mono-alkyl ether thereof, in which each alkylene group contains 2-7 carbon atoms and the alkyl group contains 1-30 carbon atoms, the copolymers (A) and (B) being present in the weight ratio of 0.15-5 parts of (A) for each part of (B).  A portion of the maleic anhydride or substituted maleic anhydride of the (A) and (B) copolymers may be replaced by a derivative thereof, namely (a) the free carboxylic acid, (b) an amide, N-alkyl amide or N-cycloalkyl amide, (c) an N-alkyl or N-cycloalkyl amine salt, or (d) an alkyl or cycloalkyl ester, the alkyl or cycloalkyl group of (b), (c) or (d) containing 1-7 carbon atoms.  Furthermore, this alkyl group may have at least one hydrogen, but not more than half thereof, substituted by a polar group or atom.  Examples of such polar groups and atoms are amino, carboxyl, cyano, amido, imino, isocyano, mercapto, nitramino, nitro, nitroso, sulpho and thiocyano groups, and chlorine and bromine atoms.  The lubricating oil may be mineral oil, a synthetic hydrocarbon oil (e.g. an alkylene polymer, an alkyl benzene or an oil derived from coal or shale), an alkylene oxide polymer or an ether or ester thereof, an ester of a dicarboxylic acid (e.g. di-n-hexyl fumarate polymer or dibutyl adipate), an ester of a phosphorus acid (e.g. tricresyl phosphate or diethyl ester of decane phosphonic acid), a polysiloxane or a silicate ester.  The lubricating composition may also contain oiliness agents, viscosity index improvers, pour-point depressants, blooming agents and peptizing agents.  In the examples, mineral lubricating oil compositions are described containing polymeric materials obtained by reacting (A) copolymers and (B) copolymers with polyethylene glycol or its monomethyl or monolauryl ether, or polypropylene glycol or its monoethyl ether.  The (A) copolymers are chosen from copolymers of maleic anhydride with allyl stearate; vinyl stearate; octadecene-1; vinyl 2-ethyl-hexyl ether; allyl stearate and vinyl 2-ethyl-hexyl ether, or maleic acid, or maleamic acid or maleimide; methallyl stearate and isobutyl maleamide or ethylene glycol monomaleate; or vinyl 2-ethyl-hexoate and octyl maleamate.  The (B) copolymers are chosen from copolymers of maleic anhydride with lauryl methacrylate (with or without allyl stearate or diisobutylene); allyl stearate and vinyl 2-ethyl-hexoate or lauryl acrylate; vinyl stearate and cetyl acrylate; methallyl stearate and lauryl acrylate; vinyl trimethyl-nonyl ether and dilauryl maleate; cetyl phenoxyethyl methacrylate; or vinyl stearyl ketone (with or without dinonyl phenoxyethyl acrylate).  The examples specify preparations and compositions of oil-soluble copolymers as follows:-(1) (A) maleic anhydride and allyl stearate were polymerized in the presence of benzene and benzoyl peroxide, tertiary butyl hydroperoxide being added later; (B) lauryl methacrylate and maleic anhydride were polymerized in the presence of tertiary butyl peroxide.  A mixture of (A) and (B) was then esterified with polyethylene glycol monomethyl ether of M.W. 550. (2) (A) as (1) (A); (B) lauryl methacrylate and maleic anhydride were polymerized in the presence of benzoyl and tertiary butyl peroxides.  A mixture of (A) and (B) was then esterified with polyethylene glycol of M.W. 300.  (3) (A) as (1) (A); (B) as (2) (B) but different proportions.  A mixture of (A) and (B) was esterfied as in (1).  (4) (A) as (1) (A); (B) the copolymer (A) was further polymerized in the presence of benzoyl and tertiary butyl peroxides with lauryl methacrylate; the resultant mixture of copolymer and terpolymer was then esterified as in (1).  The esterified mixture which contains 10 per cent free unreacted polyethylene glycol monomethyl ether may be used as an oil additive; alternatively it may be further purified by being dissolved in benzene, the polymers being precipitated with methanol.  (5) (A) as (1) (A); (B) maleic anhydride, lauryl methacrylate and allyl stearate were copolymerized in the presence of benzoyl peroxide.  A mixture of (A) and (B) was then esterified as in (1).  (6) (A) as (1) (A); (B) as (5) (B) but with tertiary butyl peroxide as a second catalyst.  A mixture of (A) and (B) was then esterified with polyethylene glycol of M.W. 400.  (7) (A) as (1) (A); (B) as (4) (B).  A mixture of (A) and (B) was then esterified with polyethylene glycol monolauryl ether.  (8) as (4). (9) as (6) but esterified as in (1).  (10) (A) as in (1) (A) was esterified as in (1) but in the presence of Pearl Oil kerosene distillate, and was purified by chromatography on silica gel; (B) as in (5) (B), esterified as in (5) (B) and purified as in (A). (11) (A) Octadecene-1 and maleic anhydride were copolymerized in the presence of benzoyl peroxide and benzene, tertiary butyl peroxide being added later; (B) as (5) (B); a mixture of (A) and (B) was esterified as in (1) and purified as in (10).  (12) (A) Maleic anhydride and vinyl 2-ethylhexyl ether were copolymerized in the presence of benzene and benzoyl peroxide; (B) as (5) (B); a mixture of (A) and (B) was esterified as in (1) and purified as in (11). (13) (A) Maleic anhydride, vinyl 2-ethylhexyl ether and allyl stearate were polymerized in the presence of benzoyl peroxide and benzene; (B) as (5) (B); mixture of (A) and (B) esterified and purified as in (11).  (14) (A) Methallyl stearate and maleic anhydride were polymerized as in (1) (A); (B) as in (5) (B); the mixture as in (1).  (15) (A) vinyl stearate and maleic anhydride as in (1) (A); (B) as in (5) (B); the mixture esterified as in (1).  In Examples (16)-(24) and (31)-(34) the following polar groups are introduced into the esterified copolymer mixtures prepared as above:-octadecyl amido, octadecyl ammonium, hydroxyethyl amido, tetraethylene pentammonium, 2,2,2 - trihydroxyl methyl propanoxy, 2-mercapto propoxy, triethanol ammonium, 2,2-hydroxy methyl 3-oleoxy propanoxy, N-(2-amino ethyl)-amido, 2-ethyl hexyl amido, octyl thio, di-hydroxy ethyl ethylene di-ammonium, and 2-nitro ethoxy.  In Examples (25)-(30) the polar groups are already present in the original copolymer (A) in the form of maleamic acid, maleimide, isobutyl maleimide, ethylene glycol monomaleate, octyl maleamate, and maleic acid. Long lists of possible alternative components are given.