Patent GB-730875-A (GB)
Title: Grease compositions
IPC: C10M169/00
Filed: 1952-05-30
Abstract: A grease composition comprises a base oil consisting essentially of a polyether oil as defined below and a polysiloxane oil as defined below, the ratio by weight of the polyether oil to the polysiloxane oil ranging from 1 to 10, together with 5-30 per cent by weight of a grease-thickening agent.  The polyether oil has the formula A-O-(R11O)n-B, where A and B represent hydrogen, alkyl radicles containing 1-12 carbon atoms, aromatic radicles, aralkyl radicles or alkaryl radicles wherein the aliphatic groups attached to the aromatic nucleus contain a total of no more than 5 carbon atoms, or ester groups R111CO (derived from the acid R111COOH where R111 is an organic radicle) containing 2-12 carbon atoms, A and B being the same or different; R11 is an alkylene radicle containing 2-4 carbon atoms; and n is a number having a value 4-20.  The polysiloxane oil has the formula <FORM:0730875/IV (a)/1> wherein R and R1 are aliphatic hydrocarbon radicles containing no more than 5 carbon atoms, aromatic radicles, alkaryl radicles or aralkyl radicles wherein the alkyl groups attached to the aromatic nucleus contain no more than 3 carbon atoms, R and R1 being the same or different; and n has a value of at least 10.  In the molecule of the polysiloxane, all of the monomeric units may not have the same formula, i.e. R and R1 may represent different radicles in different monomeric units of the same molecule. The thickening agent may be silica, bentonite, an amide (for example an aliphatic amide, an acylated phenylene diamine or an acylated urea or thiourea) or a substance of the formula (R1X)n-M, wherein R1 is a saturated or unsaturated aliphatic hydrocarbon group or an aralkyl group and contains 10-30 carbon atoms; X is a carboxy group <FORM:0730875/IV (a)/2> , a phosphonyl group <FORM:0730875/IV (a)/3> , a sulphate group <FORM:0730875/IV (a)/4> or a sulphonyl group <FORM:0730875/IV (a)/5> ; M is a metal of Group I or II of the Periodic Table; and n is the valency of M.  Thickening agents of this formula may be metal salts of fatty acids, hydroxy-stearic acid, cetylbenzoic acid, cetane sulphonic acid, dodecyl benzene sulphonic acid, dodecane phosphonic acid or lauryl sulphuric acid.  The polyether-polysiloxane base oil may contain as much as 15 per cent of a petroleum hydrocarbon oil or of lubricating oil derived from coal. The grease composition may contain additional ingredients such as stringiness agents, oxidation inhibitors, anti-wear agents, extreme pressure agents, peptizing agents and anti-thixotropic agents.  In the preparation of the thickening agents of the above-mentioned formula, acids of lower molecular weight, such as acetic acid, may be admixed with the acids forming the thickening agents before conversion to the metal salt.  In the examples, grease compositions are described which consist of a -butyl o -methyl hepta- or penta-oxypropylene diether, polymethyl siloxane, lithium and calcium stearates, and secondary additives chosen from phenyl alpha-naphthylamine, zinc dibutyl dithiocarbamate, dilauryl selenide and alizarin.  Specification 675,301, [Group III], is referred to.ALSO:A grease composition which is plastic at high temperatures as well as low temperatures, so that it is suitable for lubrication where severe variations of weather conditions are encountered, comprises a base oil consisting essentially of a polyether oil as defined below and a polysiloxane oil as defined below, the ratio by weight of the polyether oil to the poly-siloxane oil ranging from 1 to 10, together with 5-30 per cent by weight of a grease-thickening agent.  The polyether oil has the formula A-O-(R11O)n-B, where A and B represent hydrogen, alkyl radicles containing 1-12 carbon atoms, aromatic radicles, aralkyl radicles or alkaryl radicles wherein the aliphatic groups attached to the aromatic nucleus contain a total of no more than 5 carbon atoms, or ester groups R111CO (derived from the acid R111COOH where R111 is an organic radicle) containing 2-12 carbon atoms, A and B being the same or different; R11 is an alkylene radicle containing 2-4 carbon atoms; and n is a number having a value 4-20.  The polysiloxane oil has the formula <FORM:0730875/III/1> wherein R and R1 are aliphatic hydrocarbon radicles containing no more than 5 carbon atoms, aromatic radicles, alkaryl radicles or aralkyl radicles wherein the alkyl groups attached to the aromatic nucleus contain no more than 3 carbon atoms, R and R1 being the same or different; and n has a value of at least 10.  In the molecule of the polysiloxane, all of the monomeric units may not have the same formula, i.e. R and R1 may represent different radicles in different monomeric units of the same molecule.  The thickening agent may be silica, bentonite, an amide (for example an aliphatic amide, an acylated phenylene diamine or an acylated urea or thiourea) or a substance of the formula (R1X)n-M wherein R1 is a saturated or unsaturated aliphatic hydrocarbon group or an aralkyl group and contains 10-30 carbon atoms; X is a carboxy group <FORM:0730875/III/2> a phosphonyl group <FORM:0730875/III/3> a sulphate group <FORM:0730875/III/4> or a sulphonyl group <FORM:0730875/III/5> M is a metal of Group I or II of the Periodic Table; and n is the valency of M.  Thickening agents of this formula may be metal salts of fatty acids, hydroxystearic acid, cetylbenzoic acid, cetane sulphonic acid, dodecyl benzene sulphonic acid, dodecane phosphonic acid or lauryl sulphuric acid.  The polyether-poly-siloxane base oil may contain as much as 15 per cent of a petroleum hydrocarbon oil or of lubricating oil derived from coal.  The grease composition may contain additional ingredients such as stringiness agents, oxidation inhibitors, anti-wear agents, extreme pressure agents, peptizing agents, fillers and anti-thixotropic agents.  In the preparation of the thickening agents of the abovementioned formula, acids of lower molecular weight, such as acetic acid, may be admixed with the acids forming the thickening agents before conversion to the metal salt.  In the examples grease compositions are described which consist of a -butyl o -methyl hepta- or penta-oxypropylene diether, poly-methyl siloxane, lithium and calcium stearates, and secondary additives chosen from phenyl alpha - naphthylamine, zinc dibutyl dithiocarbamate, dilauryl selenide and alizarin. Specification 675,301 is referred to.