2,410,366 - LUBRKC , N. Ya ior to New York No . Application December 5, 1945, 4 Serial No. 633.0%; 8 c as? ===~ . (Cl. 25.2-49.6) This invention relates to liquid phenyl alkyl siloxane mayconsist '- siloxanes and more particularly to their use as . lubricants for metallic bearing surfaces. V one or more di?erent units selected from the class consisting of This- application is a continuation-in-part of ' my co-pending application Serial Number 432,528, ?led February 26, v1942, and assigned to the as signee of the present invention. ~- 7 j > ' ' ' The lubricants in common use are for the most part petroleum oils.‘ While they, have a- wide ' range of use, they have certain inherent defects which make them inapplicable under certain con ditions. The most evident of these defects are their ease of oxidation, their in?ammability, in stability at high temperature as evidenced by where the R's are the same or di?erent organic radicals selected from the class consisting, of phenyl and lower alkyl radicals. The incorpora acid formation and viscosity increase, inability 15 tion of these units into the siloxane polymer may ‘ be e?ected .by hydrolyzing suitable mixtures of change of viscosity with change of temperature. the corresponding silanes, i. e., SiXi, RSiXa. It is known that certain of the liquid organo to lubricate at low temperatures, and their great RzSi& and RaSlX, where X is a hydrolyzable siloxanes are useful as lubricants for . metallic bearing surfaces where the load imposed thereon 20 radical, for example, an ethoxy or a chlorine radi cal and dehydrating the hydrolysis products. is. light. However, their inability to withstand even moderateloads renders them unsuitable for The only requirement of’ such a mixture is the many applications. It would be highly desirable‘ if liquid organo-siloxanes could be found which presence of at least 40 mol. per cent of a silane of the formula (CBH5)R$1X2. lubrication of relatively moving metallic bearing surfaces under moderate or heavy loads. _ I prefer to use those liquid organo-siloxanes within the class specified above which are sub possess improved lubricity with respect to the stantially or completely dehydrated and wherein _ an appreciable amount of the unit The primary object of this invention is to pro . vide such a liquid for lubricating the bearing . (CeHa). <cmm's1o surfaces of relatively moving metallic bodies, said to is present where R’ is either a. methyl or a phenyl liquid being characterized by high resistance to - radical. Such an organo-siloxane would include oxidation, little change of viscosity with tem the following structure: perature and low pour point. Other objects and L advantages of the present invention will be read ilyapparent from the following description and 35 claims. ' I have discovered that liquid polymeric organe siloxanes comprising at least 40 mol. per cent of g the recurring unit I ' 4 R! It is understood, of course, that the (CsHs)RSiO unit'is present to the extent of at least 40 mol. 40 per cent and‘ also that still other structural units‘ may be present such as (CH3) aSiO-, etc. By substantially complete dehydration is meant the within their structure are greatly superior in their . ‘ lubricity under heavy loads to the organo-sllox . change‘ in viscosity due to condensation or elimi K nation _jof water. anes hitherto employed as lubricants. R is ‘a lower alkyl radical having from one to five car‘ bon atoms. Theremainder, it any, of the orsancf , presence of-less than 1 per cent by weight of hy .droxyl groups attached to silicon. _More than this amount results in‘ a tendency of the siloxane to The plienyl sum Susana liquids of this inven tion are characterized by relatively slight changes 50 in visco'lty over a wide range of temperature: . A - 2,410.1;40 ' lowpcur points; high ?ash points; low volatility; , composing effect upon metal or rubber; and lit . 6 , . . ‘ dioxane. ‘ An amount of water slightly in exce'ss . ' For a better understanding otmy invention, reference should be made to the following exam of the calculated quantity was slowly added. 011 dilution with water after completion of the inter condensation the product'was precipitated as an oil. ’ Example 1 - To a solution of (CcHc)(CH3)S1(OC2I-Is)a ‘and within the purview of the invention and meth - , Example 7 e ples wherein are disclosed compositinons falling 10 ods or making them. Example ' of roam) (one) 28101 were mixed and diluted with under the higher or lower temperature condi tions encountered in various types of applica tions. ’ Two-equivalents of (can) (CI-IaiSiCl-a and on low hydroscopiclty; little,v or no corrosion or de tle or no gasi?cation or solidi?cation tendencies - ' (CI-Ia)zSi(OCaHs)e1in equimolar ‘proportions 95% . ethyl alcohol containing a. few drops of concen trated hydrochloric, acid was added slowly with warming to effect hydrolysis and copolymeriza- tion. Water was'lthen added in excess. After Polymeric phenyl ethyl silicone having a vis cosity of 60 centistokes was prepared by drop- ' evaporating the solvents, a-rather viscous liquid ping phenylethylsilicon dichloride into aqueous was obtained which withstood being heated at ethyl alcohol and recovering the organo-silicon liquid. The latter exhibited marked ability to 20 190° C. for 72 hours without gelling.‘ " ‘Example 8' lubricate metallic surfaces. Since many lubri cating applications require a more viscous liquid, A mixture of 31.3 grams (C2‘H5)2S1C12 and 41 the above poly-meric silicone was treated with solid grams of (CeHs) (CzI-Is)SiC1a was hydrolyzed by sodium hydroxide in such amount that the atomic dropping in ‘7.5 cos. of water slowly with stirring ratio of Si/Na was equal to 25/1. The tempera 25 at room temperature over a period of about two ture of the mixture was held at 130-140° C. for hours. There was considerable cooling due to several hours. After washing out the alkali and evaporation of HCl. The product which was a drying by subjecting to vacuum, the viscosity of low viscosity liquid was washed with water to the product was 5023 centistokes. remove all traces of acid. Heating at elevated 30 temperatures for several hours failed to increase Example 2 the viscosity. Polymeric phenyl methyl silicone liquids of two - ‘ Example 9 different viscosities were prepared as follows: A mixture of 29.7 grams of (CH3)zSi(OCaHs)2 Phenylmethylsilicon dichloride was hydrolyzed to yield a ?uid having a viscosity of 332 centistokes. 35 and 41.0 grams of (CeHs) (C2H5)SiC12 was added This ?uid was then treated with solid sodium hydroxide in an amount corresponding to a ratio of 50 silicon atoms to one sodium atom. The temperature of the mixture was held at about 150° C. for several hours until the viscosity appeared 40 to attain a constant value. The alkali was re- . moved by neutralization and washing, leaving a ?uid of 1100 centistokes viscosity. Example 3 A copolymer was prepared from SiCl4 and (CsHs) (CH3) Si(OC2H5) 2 in the molar ratio of 1/3 by adding aqueous ethyl alcohol to the mixture dropwise. The product was a clear viscous liquid which withstood having air blown through it for dropwise over a period of 8 hours to excess water. Another 200 mol. of water was then added and the mixture was stirred about 12 hours. The co polymer and aqueous layer were separated. The copolymer was then washed once with water and was then re?uxed for an hour with an equal volume-of water. After another washing at room temperature no test for acid was obtained with the wash water. The sample was dried and 45 solvents removedzby bubbling‘ air through the sample at room temperature. It was then heated to 150° C. for about an hour under a pressure of 15 to 18 mm. The viscosity of the product at 250° C. 0 was 23.0 centistokes. Example 10 A mixture of 14.8 grams of (CI-IahSKOCaHs): and 41.0 grams of (CsHs) (CaH5)SiC12 was added Example 4 dropwise over a period of six hours to 50 ml. of A copolymer from Si(OC2H5) 4 and 66 95% CzHsOH and 50 ml. of water. The mixture was stirred for an hour after the chloride had (can) (can) SiCl2 all ‘been added with 200 ml. of water. An oily in the molar ratio of one to three was prepared liquid and an aqueous layer formed whichwere ‘ by slowly adding dropwise to the stirred mixture separated. The latter was extracted with diethyl 20 hours at 250-2'70° 10. without gelation. approximately the required amount of water di ether and the ether extract was then added to luted with an equal volume of ethyl alcohol. The 60 the copolymer oil. The ether solution was then product was a liquid which did not gel even when washed repeatedly with water until no test was air was blown through it at 200-250° C. for 18 obtained for acid in the wash water. The co hours. , Example 5 A mixture of equi-molecular parts of C2H5SiC13 and (CeHs) (C2H5)SiCh was diluted with an equal volume of dioxane. Aqueous dioxane was added polymer was then dried under 15 mm. pressure Viscosity at 25.0° C. was 65 by heating to 150° C. 29.6 centistokes. _ The superiority of the liquids of the present in ‘,ention as extreme pressure lubricants over at er organo-siloxanes hitherto used or consid ered as lubricants, was demonstrated by sub nent, turbidity developed. After removing the 70 jecting several liquids. to the following test. A solvent and any excess water by vacuum treat ball bearing was arranged to slide back and forth ment at room temperature an oil of medium on a metal test strip while being completelyim viscosity remained. It was quite ?uid at 200° C. mersed in the oil being tested. The ball bearing and its viscosity was little affected in one to two was also arranged in such a manner that varia 76 I dropwise with vigorous shaking until a perma» hours of heating at that temperature. 2,410,846 v i , ‘ 6 - ble loads could be applied thereto in order to through carbon-silicon linkages, said siloxane determine the effect of increasingload. The lubricating property of the oil was based upon containing at least 40' mol. per cent of the re curring structural unit corresponding to the for the wear or weight loss of the test strip after hav'mula (Cal-I5) RSiO where R is a lower alkyl radi- ' ing been subjected to the sliding action of the 5 cal. ' ball bearing for a period of two hours. The fol3. The method according to claim 2 wherein lowing table tabulates the results obtained in R is a methyl radical. the case of certain liquids of the present inven— 4. The method. according to claim -2 wherein tion as contrasted with other organo-siioxanes R is'an ethyl radical, as well as a conventional hydrocarbon petroleum 1o 5. The method of lubricating relatively moving oil. In this table the wear is expressed in 0.0001 metallic bodies which comprises maintaining be gram. > tween their bearing surfaces a lubricant ?lm Metals in contact wear oi test strip 25° 0. Fluid MW ' Load in grams » Bearing Test strip too 'uoo aooo 4.000 Univis No. 48 ............................ .- 61 Hard ened steeL. Bolt steel...'. Dimethyl silicone .......... __ 100 n Dieihyl silicone ............ .. 60 In 63 0 r n ..... o 160- I n Cyclic trimer oi‘ phenylethyl silicon Cylie trimer of diethyl silicone ...... .an ....................................... -. I A liquid organosilleon oxide pol 5 ...._r o ........... -4 0.-..-. \ 8 840 740 830 440 _________ -4. ____ _. .. . l .___ .1 n 588 _____do --_-. ll 4 6 872 ........... -_ er conslstin essentially of 40 mol. er cent oi C‘H OHgSiO . units- 40 mol. cent of (CHahSiOm units, and 11 mo . per cent of (éHrhSiOu units.‘ p ‘ 9 to ' per It will be observed that the liquids falling with- ' comprising a polymeric liquid phenyl methyl in the purview of the present invention exhibited silicone. wearing properties corresponding to that of the 30 6. The. method of lubricating relatively mov Standard hydrocarbon petroleum 0115. While the ing metallic bodies which comprises maintaining orsano-siloxanes. dimethyl silicone. 'diethyl 5111between their bearing surfaces a lubricant ?lm cone, and diethyl silicone trimer werede?nitely comprising a polymeric liquid phenyl ethyl sili inferior to both the hydrocarbon oil and the phenyl alkyl siloxanes. I'claim: . ‘ cone, 35 , - 'l. The method of lubricating relatively moving metallic bodies which comprises maintaining Y 1. The method of lubricating relatively moving between their bearing surfaces a lubricant ?lm metallic bodies which comprises maintaining be» comprising a substantially completely dehydrat tween their bearing surfaces a lubricant ?lm ed liquid polymeric organo-siloxane whose or comprislng a liquid polymeric cream-5110mm 40 ganic substituents consist essentially 01 lower whose organic substituents consist essentially of alkyl and phenyl radicals attached to, silicon lower alkyl and phenyl radicals attached to silicon through carbon-silicon linkages, said silox- through carbon-silicon linkages, said ' siloxane . contaimn at least 40 mol. per cent of the recur ane containing at least 40 mol. per cent of the ring structural ,unit. corresponding to the' for recurring structural unit corresponding to the 45 mula (CcHs)RSiO where R is a lower alkyl radi iormula (CsH5)RSlO where R. is a lower alkyl cal and said siloxane also containing structur radical. ' ' 1 2. The method of lubricating relat vely moving metallic bodies which comprises maintaining units corresponding to the formula _ > ‘ ' ‘ ' , “mm (0393 810m between their‘ bearing surfaces a lubricant ?lm 50 where R’ is selected from the class consisting 01' comprising a substantially completely dehydratphenyl and methyl radicals. . ed liquid polymeric organo-siloxane whose or8. The method according to claim 7 wherein ganic substituents consist essentially 01 lower ' R and R’ are methyl radicals. alkyl and phenyl radicals attached to silicon JAMES FRANKHN HiZDE.