Patent GB-667179-A (GB)
Title: A method of lubricating moving metallic parts and a composition therefor
Filed: 1949-02-07
Abstract: A liquid copolymeric siloxane having a degree of substitution of greater than 2 and less than 3 organic radicles per silicon atom is employed as a lubricant (see Group III).  The liquid polymeric siloxane is characterized in that (i) at least 5 per cent of the silicon atoms therein have at least one halogenated phenyl radicle attached thereto; (ii) the halogenated phenyl radicle of (i) is mono- or di-bromophenyl, mono- or di-chlorophenyl or chlorobromophenyl; (iii) apart from the halogenated phenyl radicles mentioned in (i), all the remaining organic radicles therein are methyl and/or phenyl radicles and (iv) at least 37 per cent of the total number of organic radicles therein are methyl radicles.  The lubricant may be thickened to grease structure with the aid of a thickening agent.  Thickening agents mentioned are alkali metal salts and alkaline earth metal salts of fatty acids having at least 8 carbon atoms in the molecule, or of alicyclic substituted fatty acids wherein the fatty acid has a chain length of from 1 to 6 carbon atoms. Alicyclic substituted fatty acids mentioned are cyclohexylacetic, cyclohexylpropionic, cyclohexylbutyric, cyclohexylvaleric, cyclohexylcaproic, alpha butylcyclohexylacetic, gamma ethylcyclohexylbutyric, alpha 4 - diterbutylcyclohexylbutyric, alpha 4 - disecbutylcyclohexylbutyric, 2-cyclohexene caproic, pentalaneacetic (see Group IV (b)) and cyclopentylvaleric acids. Specified thickeners mentioned are lithium stearate and lithium cyclohexylcaproate.  The lubricant may contain corrosion inhibitors and other conventional additives.  When the lubricant is in the form of a grease, it may be acid, neutral or alkaline, and the thickening agent may be added as such or prepared in situ. In examples, lubricants are prepared (a) by the co-hydrolysis of 270 gms. of chlorophenylmethyldichlorosilane, 1238 gms. of dimethyldichlorosilane and 204.6 gms. of phenyldimethylchlorosilane, and (b) by refluxing a mixture of 51.2 gms. of liquid chlorophenylmethyl siloxane, 198.5 gms. of mixed cyclic dimethylsiloxanes (prepared according of the Specification 571,725) and 2.3 gms. of <FORM:0667179/IV (a)/1> in presence of KOH till no more water is evolved and heating the product first alone and then in presence of trimethyl chlorosilane.  Lubricants are also described having the following mol. per cent composition:-10ClC6H4(CH3)SiO, 89.5(CH3)2SiO, 0.5(CH3)3 SiO 1/2 ; 35C6H5(CH3)2 SiO 1/2 , 65ClC 1/2 H4(CH3)SiO; 25(CH3)3SiO 1/2 , 75 ClC6H4(CH3)SiO; 20C6H5 (CH3)2SiO 1/2 , 40(CH3)2SiO, 40ClC6H4(CH3)SiO; 15C6H5(CH3)2SiO 1/2 , p  75(CH3)2SiO, 10ClC6H4(CH3) SiO; 10(CH3)3SiO 1/2 , 85(CH3)2SiO, 5ClC6H4 (CH3)SiO; 1(CH3)3SiO 1/2 , 89(CH3)2SiO, 10ClC6H4 (CH3)SiO; 10(C6H5)2CH3 SiO 1/2 , 80(CH3)2SiO, 10ClC6H4(CH3)SiO; 10ClC6H4(CH3)2SiO 1/2 , 80 (CH3)2SiO, 1.25ClC6H4(CH3)SiO, 8.75CH3(C6H5) SiO; 20(CH3)3SiO 1/2 , 30(CH3)2SiO, 40C6H5(CH3) SiO, 10ClC6H4(CH3)SiO; 10(CH3)3SiO 1/2 , 80 (CH3)2SiO, 10BrC6H4(CH3)SiO; 5(ClC6H4)2 SiO, 85(CH3)2SiO, 10(CH3)3 SiO 1/2 ; 10Cl2C6H3 (CH3)SiO, 80(CH3)2SiO, 10(CH3)3SiO 1/2 ; and 10(CH3)3SiO 1/2 , 65(CH3)2SiO, 25ClC6H4(CH3)SiO.  In a further example a lubricant having the mol. per cent composition 10(CH3)3SiO 1/2 , 90 ClC6H4(CH3)SiO is thickened to grease structure by the preparation in situ of lithium cyclohexylcaproate, the preparation method employed being the neutralization of the corresponding acid with LiOH, H2O. Tests are described in which the performance of the lubricants of the invention is compared with that of lubricants having the following mol. per cent composition:-25(CH3)3SiO 1/2 , 75CH3 (C6H5)SiO; 10(CH3)3SiO 1/2 , 80(CH3)2SiO, 10CH3 (C6H5)SiO; and 10(CH3)3SiO 1/2 , 90(CH3)2SiO.ALSO:A substance referred to as pentalane-acetic acid may be employed, in the form of its alkali metal or alkaline earth metal salt, as an ingredient in a lubricating composition (see Group III). The substance has the formula <FORM:0667179/IV (b)/1> and is prepared by heating hydroxy-tetrahydronordicyclopentadiene with a fused alkali metal hydroxide at a temperature of 275 DEG  to 375 DEG  C.ALSO:A lubricant, especially suitable for the lubrication of metallic bearing surfaces operating under load and at extremes of temperature, comprises a liquid copolymeric siloxane having a degree of substitution of greater than 2 and less than 3 organic radicles per silicon atom.  The liquid copolymeric siloxane is characterized in that (i) at least 5 per cent of the silicon atoms therein have at least one halogenated phenyl radicle attached thereto; (ii) the halogenated phenyl radicle of (i) is mono- or di-bromophenyl, mono- or di-chlorophenyl or chlorobromophenyl; (iii) apart from the halogenated phenyl radicles mentioned in (i), all the remaining radicles therein are methyl and/or phenyl radicles; and (iv) at least 37 per cent of the total number of organic radicles therein are methyl radicles. The lubricant may be thickened to grease structure with the aid of a thickening agent.  Thickening agents mentioned are alkali metal salts and alkaline earth metal salts of fatty acids having at least 8 carbon atoms in the molecule, or of alicyclic substituted fatty acids wherein the fatty acid has a chain length of from 1 to 6 carbon atoms.  Alicyclic substituted fatty acids mentioned are cyclohexylacetic, cyclohexylpropionic, cyclohexylbutyric, cyclohexylvaleric, cyclohexylcaproic, alpha butylcyclohexylacetic, gamma ethylcyclohexylbutyric, alpha 4-diterbutylcyclohexylbutyric, alpha 4-disecbutylcyclohexylbutyric, 2-cyclohexenecaproic, pentalane-acetic (see Group IV(b)) and cyclopentylvaleric acids. Specific thickeners mentioned are lithium stearate and lithium cyclohexylcaproate.  The lubricant may contain corrosion inhibitors and other conventional additives.  When the lubricant is in the form of a grease, it may be acid, neutral or alkaline, and the thickening agent may be added as such or prepared in situ. In an example, a lubricant is prepared by the co-hydrolysis of 270 gms. of chlorophenylmethyldichlorosilane, 1238 gms. of dimethyldichlorosilane and 204.6 gms. of phenyldimethylchlorosilane. Lubricants are also described having the following mol per cent composition: 10ClC6H4(CH3)SiO, 89.5(CH3)2SiO, 0.5(CH3)3SiO 1/2 ; 35C6H5(CH3) 2SiO 1/2 , 65ClC6H4 (CH3)SiO; 25(CH3)3SiO 1/2 , 75ClC6H4(CH3)SiO; 20C6H5(CH3)2SiOe, 40(CH3)2SiO, 40ClC6H4 (CH3)SiO; 15C6H5(CH3)2SiO 1/2 , 75(CH3)2SiO, 10ClC6H4(CH3)SiO; 10(CH3)3SiO 1/2 , 85(CH3)2 SiO, 5ClC6H4(CH3)SiO; 1(CH3)3SiO 1/2 , 89 (CH3)2SiO, 10ClC6H4(CH3SiO; 10(C6H5)2 CH3SiO 1/2 , 80 (CH3)2SiO, 10ClC6H4(CH3)SiO; 10ClC6H4(CH3)2SiO 1/2 , 80(CH3)2SiO, 1.25 ClC6H4(CH3)SiO, 8.75CH3(C6H5) SiO; 20 (CH3)3SiO 1/2 , 30(CH3)2SiO, 40C6H5(CH3)SiO, 10ClC6H4(CH3)SiO; 10(CH3)3SiO 1/2 , 80(CH3)2 SiO, 10BrC6H4(CH3)SiO; 5(ClC6H4)2SiO, 85(CH3)2SiO, 10(CH3)3SiO 1/2 ; 10Cl2C6H3(CH3) SiO, 80(CH3)2SiO, 10(CH3)3SiO 1/2 ; and 10(CH3)3SiO 1/2 , 65(CH3)2SiO, 25ClC6H4(CH3) SiO.  In a further example a lubricant having the mol per cent composition 10(CH3)3SiO 1/2 , 90ClC6H4(CH3) SiO is thickened to grease structure by the preparation in situ of lithium cyclohexylcaproate, the preparation method employed being the neutralization of the corresponding acid with LiOH, H2O.  Tests are described in which the performance of lubricants of the invention is compared with that of lubricants having the following mol per cent composition: 25(CH3)3SiO 1/2 , 75CH3(C6H5) SiO; 10(CH3)3SiO 1/2 , 80(CH3)2SiO, 10CH3 (C6H5)SiO; and 10(CH3)3SiO 1/2 , 90(CH3)2SiO.