|Publication number||US3669884 A|
|Publication date||Jun 13, 1972|
|Filing date||Jun 29, 1970|
|Priority date||Jun 29, 1970|
|Also published as||DE2132058A1, DE2132058C2|
|Publication number||US 3669884 A, US 3669884A, US-A-3669884, US3669884 A, US3669884A|
|Inventors||John H Wright|
|Original Assignee||Gen Electric|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (4), Referenced by (17), Classifications (58)|
|External Links: USPTO, USPTO Assignment, Espacenet|
United States Patent Wright 1 June 13, 1972  METHYL ALKYL SILICONE GREASE 3,158,574 11/1964 Greenwood et al ..252/36 CONTAINING ZINC NAPHTHENATE 3,355,384 11/1967 Scott  Inventor: John H. Wright, Elnora, NY.
 Assignee: General Electric Company  Filed: June 29, 1970 ] Appl. No.: $0,890
Related U.S. Application Data  Continuation-impart of Ser. No. 26,l53, April 6, 1970, which is a continuation-in-part of Ser. No. 762,322, Sept. 16, 1968.
 US. Cl ..252/36, 252/372, 252/389 [5 1] Int. Cl. ..Cl0m 7/50, ClOm 7/20  Field otSearch ..252/36, 10, 37.2, 389
 References Cited UNITED STATES PATENTS 3,349,034 10/1967 Butcosk et al. ..252/36 2,998,384 8/l96l McGrath et a1 ..252/28 Primary Examiner-Daniel E. Wyman Assistant Examinerl. Vaughn Attorney-Donald J. Voss, Donavon L. Favre, Frank L. Neuhauser, Oscar B. Waddell and Joseph B. Forman ABSTRACT A grease composition containing a polysiloxane, the organic substituents of which are primarily methyl radicals and C to C alkyl radicals, a thickener, and zinc naphthenate. The presence of the zinc naphthenate in the grease provides corrosion resistance to iron and iron alloy metal surfaces to which the grease is applied. The composition may be prepared by heating the polysiloxane and the thickener together at a temperature of about 240 C with mixing, cooling the mixture partially, adding the zinc naphthenate during the remainder of the cooling period, and then milling the resulting material. The grease composition was used to lubricate door hinges on houses and automobiles.
12 Claims, No Drawings METHYL ALKYL SILICONE GREASE CONTAINING ZINC NAPHTHENATE CROSS REFERENCE TO RELATED APPLICATIONS BACKGROUND OF THE INVENTION This invention relates to improved polymethyl-alkylsiloxane grease compositions. More particularly, the present invention is concerned with zinc naphthenate containing polyorganosiloxane grease compositions, 25 per cent to 50 per cent of the organic substituents of which are alkyl radicals having six to 20 carbon atoms.
Organopolysiloxane greases and grease compositions are well known in the art and have been used as lubricants, dielectric compounds, sealing compounds and high vacuum greases. These organopolysiloxane greases have been particularly valuable because of their high degree of heat stability, their water repellency, their low temperature viscosity characteristics and dielectric properties.
While the polysiloxane components in the grease are not broken down by oscillatory or fluttering motion, it has been found that where the greases have been employed to lubricate iron or iron alloy wearing surfaces subject to oscillatory or fluttering motion, the film formed by the greases ruptured and allowed metal to metal contact. This has resulted in both severe wear and severe corrosion of the surfaces. Even when the greases have been used on iron containing surfaces which have not been subjected to contact with other surfaces, the surface has been subjected to a degree of corrosion.
SUMMARY OF THE INVENTION To solve this problem of film breakdown and corrosion on iron or iron alloy surfaces lubricated or coated with silicone greases, the present invention is based upon the discovery that when from 25 to 50 percent of the organic groups present on the polysiloxane component of the grease contained from six to 20 carbon atoms and zinc naphthenate is present in the grease composition, that the problem of grease film rupture and corrosion of iron containing surfaces is alleviated.
DESCRIPTION OF THE PREFERRED EMBODIMENTS The grease compositions of the present invention comprise on a weight basis:
1. from 50 to 98 percent of a polymethylalkyi-siloxane fluid containing from 25 to 50 percent, based upon the total number of organic substituents of alkyl groups containing from six to 20 carbon atoms, preferably l carbon atoms;
2. from 2 to 35 percent of a thickener, preferably a lithium soap of a higher fatty acid having from l2 to 22 carbon atoms such as a lithium soap of lauric, myristic, palmitic or stearic acid, preferably myristic or stearic acid;
3. from about 0.0l to about 2 percent of zinc as zinc naphthenate. The following ingredients may also op tionally be present; from 0.01 to 5.0 percent of a polyether and preferably from 0.01 to 2.0 percent of polyether;
5. a base such as lithium hydroxide in an amount sufficient to maintain the grease on the alkaline side.
As many of the thickeners which are fatty acid soaps which are employed in the manufacture of greases of the present invention are alkaline, the addition of additional alkaline material such as lithium hydroxide is often not recommended.
The fluid methylalkylpolysiloxanes employed in the practice of the present invention can be characterized as having the average unit formula:
The sum (m n +p+q) has a value offrom 2.002 to 3.0; n has a value offmm 0.50 to 1.95; in has a value offrom 0.50 to l.00;phas a value offrom 0 to0.5;qhasa value offrorn 0 to one-fourth (m n p); R is an alkyl radical containing from six to 20 carbon atoms, e.g., hexyl, octyl, decyl, dodecyl, tetradecyl, octadecyl radicals; R is a t-butyl-substituted hydroxyaryl radical and has the formula:
where Y is a member selected from the class consisting of hydrogen, monovalent hydrocarbon radicals, hydroxyaryl radicals, hydroxyaryl-substituted monovalent hydrocarbon radicals, hydroxyaryl ethers joined to the t-butyl-substituted hydroxyaryl radical through the ether linkage, hydroxyarylthioethers joined to the t-butyl-substituted hydroxyaryl radical through the thioether linkage and hydroxyaryl-methylene ethers joined to the t-butyl-substituted hydroxyaryl radical through the methylene ether linkage; R" is selected from the class consisting of lower alkyl radicals having one to five carbon atoms, e.g., methyl, ethyl, propyl, butyl, pentyl, etc. radicals; cycloalkyl radicals having five to seven carbon atoms in the ring, e.g., cyclopentyl, cyclohexyl, cycloheptyl, etc. radicals; mono-nuclear and binuclear aryl radicals, e.g., phenyl, naphthyl, biphenyl, etc. radicals; mononuclear aryl lower alkyl radicals, e.g., benzyl, tolyl, xylyl, phenylethyl, etc. radicals and halogenated derivatives of the above radicals.
Although any methylalkylpolysiloxane fluid within the scope of formula l is applicable in the process of the present invention, it is preferred that the fluid have a viscosity of from about 10 centistokes to about 100,000 centistokes when measured at 25 C.
it should be understood that the methylalkylpolysiloxane fluids of formula l can include siloxane units of varied types and formulation such as trimethylsiloxane units and methylalkylsiloxane units alone or in combination with units such as monomethylsiloxane units, monoalkyl-siloxane units, dialkylsiloxane units, trialkylsiloxane units, etc. The only requirement is that the ratio of the various siloxane units employed be selected so that the average composition of the copolyrneric fluid is within the scope of formula l One component of the grease compositions of the present invention are the grease thickening agents which are well known in the art. This invention contemplates the use of any of these well known thickening agents to form a grease composition of the desired consistency. The term grease as employed in the present application is intended to refer to greaselike materials which may have consistencies varying from readily flowable materials to materials which exhibit almost no flow. The consistence of the greases of the present invention depend on the amount of thickening agent employed, the type of thickening agent employed and the particular polysiloxane fluids in the grease. Examples of suitable thickening agents include the metallic soaps of fatty acids of at least eight carbon atoms where the metals in such soaps include aluminum, lead, zinc, manganese, lithium, sodium, potassium, calcium, barium, strontium, copper, mercury, bismuth, chromium, iron, cobalt, nickel, etc. The use of many of such metal soaps are disclosed in US. Pats. Nos. 2,456,642 and 2,599,984. Metallic soaps of shorter chain length fatty acids such as acids containing from two to six carbon atoms as well as hydroxy-substituted fatty acids and hydroxy-substituted fatty acid glycerides such as are disclosed in 0.8. Pat. Nos. 2,551,93l and 2,508,741 may also be employed as thickening agents.
Other specific metallic soaps which can be used as thickening agents in the practice of the present invention include lithium-2-ethylhexoate, lithium hydroxy stearate, lithium myristate and lithium caprate.
The metal soap usually used as a thickener in the composition of the present invention is basic and maintains the grease on the alkaline side, so that no additional base is necessary.
In addition to metal soaps, the compositions of the present invention may employ as grease thickening agents finely divided inert oxides of metallic and quasi-metallic materials such as silica, alumina, iron oxide, titania, zinc oxides, glass fibers and clays. Silica, when used as a thickening agent, is preferably employed as an aerogel, but may also be employed as fumed silica, precipitated silica, or silica derived from natural deposits such as diatomaceous earth.
in addition to the relatively simple thickening agents described above, the invention of the present application contemplates the use of complex metal soaps such as aluminum benzoate stearate as described in US. Pat. No. 2,599,553, acyl ureas such as octadecanoyl urea as described in US. Pat. No. 2,698,300 and the phenylenediamides such as N,N-acetylstearoyl-p-phenylenediamides as described in U.S. Pat. No. 2,709,157. In addition, a particularly useful group of thickening agents are the aromatic substituted ureas which are commonly referred to as ASU thickeners. The most useful thickeners are the lithium soaps of any of the higher fatty acids having from l2 to 22 nomcarboxyl carbon atoms. Another suitable thickening agent is phthalocyanine, finely divided inert oxides of metallic and quasi-metallic materials, carbon black, graphite, polyethylene, and phthalocyanine acyl ureas.
The term grease as employed in the present application is intended to refer to grease-like materials which may have consistencies varying from readily flowable materials to materials which exhibit essentially no flow. The consistency of the greases of the present invention depend on the amount of thickening agent employed, the particular thickening agent employed and the particular polysiloxane fluids in the grease. The most useful thickening agents are the lithium soaps of higher fatty acids of l2 to 22 non-carboxyl carbon atoms such as lauric, palmitic, and most preferably the lithium soaps of myristic and stearic acids.
While, as explained above, the amounts of thickening agent employed in the grease compositions of the present invention are not critical and may vary within wide limits depending on the particular consistency desired in the final product, it has been found that the amount of thickening agent usually varies from about 2 per cent to 35 per cent and preferably from about 5 per cent to 25 per cent by weight based on the weight of the polysiloxane in the grease composition.
In order to protect against corrosion when the grease is used on an iron or iron alloy surface, zinc naphthanate is added as a corrosion inhibitor. Generally, from about 0.01 to about 2 percent of zinc as zinc naphthanate based upon the weight of the grease composition is added. The preferred range is from about 0.02 to about 1 percent zinc as zinc naphthanate.
A polyether may also be optionally present as a stabilin'ng agent. When the polyether is present, it is preferably that it be present in an amount equal to from about 0.0l to about 5 per cent by weight based upon the weight of the polysiloxane fluid in the composition and preferably from about 0.] to about 2 percent by weight. When the amount of polyether in the grease composition is in excess of 5.0 percent by weight, it is found that the weight loss of the grease at temperatures in excess of 300 F is so excessive that the grease is unsuitable for use in many high temperature applications.
The polyether is not a necesary stabilizing agent, however, as any number of other known stabilizing agents may be used or the stabilizing agent may be omitted entirely. Trimethoxyboroxine is an excellent stabilizing agent. In some of the fol lowing examples, polyethers are added to the oxidation inhibited higher alkyl containing grease compositions to impart a royal purple or brown color to the grease. This is its primary function. Without the polyether in the oxidation inhibited higher alkyl containing greases, they have a lack-luster pinkish tinge.
The polyethers which are used herein in combination with the polysiloxane oils according to this invention are polymeric alkylene oxides and/or polymeric alkylene glycols and may be represented by the following formulas:
wherein A and B represent radicals selected from the class comprising hydrogen, alkyl radicals containing from one to 12 carbon atoms, cycloalkyl radicals containing five to seven carbon atoms in the ring, mononuclear and binuclear aryl radicals and mononuciear aryl lower alkyl radicals wherein the alkyl groups attached to the aromatic nucleus contain a total of no more than five carbon atoms; A and 8 also represent ester forming groups containing from two to 12 carbon atoms; A and B may or may not be alike. When there is more than one A radical per molecule, the A radicals may or may not be the same. 0 is a residue of a polyhydn'c initiator radical containing at least two hydroxyl radicals such as ethylene glycol, glycerol, trimethylolpropane, and other polyhydric alcohols having from 2 to 6 hydroxyl groups; x is a number having a value of2 to 4; n is a number having a value offrom 4 to 2,000 andyhasavalue offrom2to6andzhasa value ofone to S.
More specifically, A and B represent radicals selected from the clas comprising hydrogen; alkyl radicals having from one to l2 carbon atoms, e.g., mefllyl, ethyl, propyl, butyl, octyl, etc. radicals; cycloalkyl radicals having five to seven carbon atoms in the ring, e.g., cyclopentyl, cyclohexyl, cycloheptyl, etc. radicals; mononuclear and binuclear aryl radicals, e.g., phenyl, naphthyl, biphenyl, etc. radicals; mononuclear aryl lower alkyl radicals wherein the alkyl groups attached to the aromatic nucleus contain a total of no more than five carbon atoms, e.g., benzyl, phenylethyl, phenylpropyl, etc.; and ester groups having from one to 12 non-carboxyl carbon atoms such as the residues formed by the removal of a carboxy hydrogen from a fatty acid, e.g., an acetate, propionate, octoate, etc.; hydroxy-ether groups derived from glycols such as butylene glycol, octylene glycol, etc.; and groups formed by esterification with a hydroxyl group of a non-fatty acid, e.g., propyl phosphate, octyl sulfonate, butyl sulfate, etc.
The polyethers may be prepared from the various alkylene oxides (e.g., ethylene oxide), the higher l,2-epoxides (such as l,2-propylene oxide), the alkylene glycols (e.g., ethylene glycol) and mixtures of these. The resulting products may be polyoxyalkylene diols or polyalkylene glycol derivatives; that is, the terminal hydroxyl groups can remain as such, or one or both of the terminal hydroxyl groups can be removed during the polymerization reaction or subsequent thereto, as by ethenfication or esterification to yield monoor di-ether or monoor di-ester groups or a combination of such terminal groups whereby certain desirable properties are imparted to the final polymeric mistures. For example, in the above formula A and/or B may be: alkyl radicals, forming a di-alkyl polyether (e.g., dibutylheptaoxypropylene di-ether); ester forming radicals, forming alkyl oxyalkylene esters (e.g., butylpentaoxypropylene acetate); hydrogen, forming polyglycols (e.g., polyethylene glycol), etc.
To further exemplify the polyethers which can be used, the polyether oil, that is, the (C,H, ,O),, section of the above formula can be derived from such basic units as the following oxides:
CH: tert-butylene oxlde(CH:( 3O), etc.
or basic units obtained by the dehydration of alkylene glycols, resulting in the formation of the following:
ethylene oxide (CH,CH,-O),
propylene oxide (CH,CH,--CH,O),
butylene oxide (CH,CH,-CH,CH,-O etc.
Polyethers containing combinations of the above described basic units have been found to be quite useful in the practice of the present invention. A composition containing two different alkylene oxide groups can be prepared, for example, by reacting a polypropylene glycol with ethylene oxide in the presence of boron trit'luoride. This mixed polyalkylene glycol, if desired, can then be reacted with an alkanol such as butanol to form the monobutoxy-ether of the mixed polyalkylene glycol. A number of these polyalkylene oxide materials are commercially available including the materials sold under the tradename Ucon by Union Carbide Corporation, and the materials sold under the name of "Pluracol" by the Wyandotte Chemicals Corporation.
The molecular weight of the polyether oils used according to this invention can range from 300 to 200,000, from 400 to 20,000 being preferred.
In the preferred embodiment of my invention, an antioxidant which is built into the polysiloxane molecule is used. This antioxidant is represented by the R' radical of formula (I) which is a t-butyl-substituted hydroxy-aryl radical and has the formula:
( l Hi):
where Y is a member selected from the class consisting of hydrogen, monovalent hydrocarbon radicals, hydroxyaryl radicals, hydroxyaryl-substituted monovalent hydrocarbon radicals, hydroxyaryl ethers joined to the t-butyl-substituted hydroxyaryl radical through the ether linkage, hydroxyarylthioethers joined to the t-butyl-substituted hydroxyaryl radical through the thioether linkage and hydroxarylmethylene ethers joined to the t-butyl-substituted hydroxyaryl radical through the methylene ether linkage. As is seen from formulas (l) and (2), the R radical has a valence bond attached to the aromatic nucleus and to a divalent propylene radical which, in turn, is attached to a silicon atom of the polysiloxane. In the ortho position with respect to this valence bond is a hydroxy radical and in the meta position is a tertiary butyl radical. in the other meta position is the Y radical previously described. The t-butyl group is adjacent to the hydroxyl group and hinders its reactivity. Thus, the hydroxyaryl radical is a hindered hydroxyaryl radical.
Among the monovalent hydrocarbon radicals free of aliphatic unsaturation represented by Y in formula (2) are, for example, alkyl radicals, e.g., methyl, ethyl, propyl, butyl, octyl, etc. radicals; aryl radicals, e.g., phenyl, naphthyl, etc. radicals; aryl lower alkyl radicals, e.g., benzyl, phenylethyl, etc. radicals. Among the hydroxyaryl radicals represented by Y of formula (2) are, for example p-hydroxyphenyl, o,o-di(t-butyl )-p-hydroxy-phenyl, o-( t-butyl )-o-allyl-p-hydroxyphenyl, etc. radicals. Illustrative of the hydroxyaryl-substituted monovalent hydrocarbon radicals within the definition of Y of formula (2) are, for example, p-hydroxyphenylmethyl radicals, o,o-di(t-butyl)-p-hydroxyphenylethyl radicals. illustrative of the hydroxyarylether radicals are o,o-di(t-butyl)-phydroxyphenylether radicals and o,o-di(t-butyl)-p-hydroxyphenylmethylene ether radicals. Illustrative of the hydroxyarylthioether radicals is the o,o-di(t-butyl)-phydroxyphenylether radical, etcv Illustrative of specific radicals represented by R" of formula (l)are, for example:
$(CHr): IH OI The nature of the compositions within the scope of the present invention is best understood by reference to the preparation of the compositions which contain the siliconbonded t-butyl-substituted hydroxyarylpropyl radical. The general method of preparation involves a starting material which contains a phenyl nucleus containing a nuclear carbonbonded hydroxyl group and tertiary butyl radical in both of the meta positions of such phenolic compound. One or more of the nuclear-bonded t-butyl radicals is replaced by an allyl radical to produce an allyl-substituted material having the formula:
R'CH,Cl-l CH,, where R is as previously defined. The allyl radical of this material is then reacted with an organopolysiloxane containing silicon-hydrogen linkages so as to attach the phenyl nucleus to the silicon atom through the propylene radical.
As a general illustration of this method, a commercial phenolic compound having the formula:
C(CHa): i t)! H0 0H 0H (Cl-Is): I)!
CH CH=CH The allylated product is then reacted with the silicon hydrogen-containing polysiloxane in the presence of a platinum compound catalyst to produce the desired product.
in addition to the above-described components, additives normally present in silicone greases can be present in the composition of the present invention. Examples of additives include antioxidants such as the amines, e.g., N-phenyl-alphanaphthylamine; extreme pressure additives such as selenium disulfide, molybdenum disulfide, etc.; acids or bases to control pH; and antioxidants is within the scope of this invention. The addition of many of such materials is described in the art.
The preparation of the polysiloitanes within the scope of formula l) involves an SiH-olefin addition reaction. This reaction simply involves the addition ofan alpha-olefin having 2 where n, m, p, q and R" are as above defined, and an alphaolefin. The reaction of the alpha-olefin and the polysiloxane of formula (3) can take place in the presence of one of the elemental platinum or platinum compound catalysts. The platinum compound catalyst can be selected from that group of platinum compound catalysts which are operative to catalyze the addition of silicon-hydrogen bonds across olefinie bonds.
Among the many useful catalysts for this addition reaction are chloroplatinic acid as described in US. Pat. No. 2,823,2 l 8 Speier et al.; the reaction product of chloroplatinic acid with either an alcohol, an ether or an aldehyde as described in U.S. Pat. No. 3,220,972 Lamoreaux; trimethyl platinum iodide and hexamethyldiplatinum as described in U.S. Pat. No. 3,313,773 Lamoreaux; the platinum olefin complex catalysts as described in U.S. Pat. No. 3,159,601 of Ashby and the platinum cyclopropane complex catalyst as described in U.S. Pat. No. 3,l59,622 of Ashby.
The SiH-olefin addition reaction may be run at room temperature or at temperatures up to 200 C, depending upon catalyst concentration. The catalyst concentration can vary from 10" to l" and preferably to 10 moles of platinum as metal per mole of olefin containing molecules present. Generally, the methylhydrogenpoly-siloxane is mixed with a portion of the alpha-olefin, all of the catalyst is added, and then the remaining alpha-olefin is added at a rate sufficient to maintain the reaction temperature in the neighborhood of from about 50 to I C and, at the end of the addition of the alpha-olefin, the reaction is completed.
The addition reaction is effected by adding to the methylhydrogen polysiloxane a platinum catalyst of one of the types previously described and then one of the allylated materials previously described is slowly added to the reaction mixture at a rate sufficient to maintain the reaction mixture at the desired reaction temperature, which is usually of the order of 50 to 120 C. The amount of the allylated material added to the reaction mixture is the amount which it is desired to react with the SiH-containing polysiloxane. The allylated aromatic compound is sdded in the ratio of from 0 to 0.5 molecule for every silicon-bonded hydrogen atom of the methylhydrogenpolysiloxane. This results in the conversion of each siloxane unit reacted from a methylhydrogen siloxane unit to a siloxane unit containing one silicon-bonded methyl radial and one siliconbonded t-butyl-substituted hydroxyaryl-propyl radical. The appropriate amount of alpha-olefin is then added and reacted via the afore-described SiH-olefin addition reaction.
When preparing a linear copolymer of the type described in formula l the general procedure as described earlier is followed. The polymethylhydrogensiloxane is first reacted with the appropriate amount of the allylated material and then the appropriate amount of alpha-olefin is added. For example, when it is desired to produce a product within the scope of formula (l in which n is l. l, m is 0.925, p is 0.025 and q is 0, the starting material can be a trimethylsilyl chain-stopped polymethyl-hydrogensiloxane containing an average of 38 methylhydrogen-siloxane units per molecule. One mole of this polymethyl-hydrogensiloxane is reacted with 1 mole of an allylated t-butyl-substituted phenol, such as the product shown in the formula:
to produce a trimethylsilyl chain-stopped oopolymer in which the average molecule contains 37 methylhydrogensiloxane units and 1 unit in which the R is the radical shown in the formula:
Ha): HIJ: H0@CHOH (CHI):
Then one mole of the resulting copolymer is reacted with 37 moles of an appropriate alpha-olefin, such as decene-l, ac cording to the method previously described to produce a copolymer within the scope of formula l in which n is l. l m is 0.925, p is 0.025 andq is 0.
The grease of the present invention is quite adaptable to aerosol type packaging. This involves dissolving the grease in a volatile solvent, adding an organic aerosol propellant and packaging the mixture in a pressurized type dispenser, such as the usual low pressure aerosol can. if desired, the organic aerosol propellant can also be employed as the solvent.
Propellants which can be employed come from three classes; compressed inert gasses, hydrocarbons and halogenated hydrocarbons. An additional requirement for the halogenated hydrocarbon or hydrocarbon used as the propellant is that it have a vapor pressure greater than atmospheric pressure at a temperature of l05 F and that it be a liquified as. g The compressed gasses which may be employed include the non-liquifiable gasses, such as air, nitrogen, carbon dioxide, nitrous oxide and other materials which were used in the gaseone state or which are dissolved in the aerosol mixture instead of being added as liquified gasses.
Examples of halogenated hydrocarbons which may be employed as propellants, include monofluorotrichloromethane, dichlorodifluoromethane, dichlorofluoromethane,
difluorochloromethane, dichloromethane, l-chloro-l, l-difluoro-Z-chloro-Z, Z-difluoroethane, l-fluoro-l, l-dichloro- 2,2,2-trifluoroethane, l-chloro-l, l-difluoroethane, l,ldifluoroethane, monochloroethane, l,l-difluoro-2, 2-difluoro-3,3-difluoro-4,4-difluorocyclobutane, l, l l -tri-fluoro- 2, 2-difluoro-3, 3-difluoro-4,4,4-trifluorobutane.
Examples of hydrocarbon propellants which may be employed are propane, isobutane, and butane.
Mixtures of the above-described propellants may also be used. When a gas is used as the aerosol propellant, the gas must be inert to the other components of the mixture and is preferably present in a quantity to provide a pressure of l5 to I00 pounds per square inch at I00 F in the interior of the aerosol container.
In addition to the propellant, it is preferred that a solvent also be present. Solvents which may be employed include hydrocarbons, aromatic hydrocarbons, aliphatic hydrocarbons and halogenated derivatives of aromatic and aliphatic hydrocarbons. The solvents are preferably volatile to the extent that they will evaporate from the grease upon prolonged exposure, i.e., 24 hours when exposed to the atmosphere. It is also preferable that the solvents have melting points below 0 Examples of solvents which may be employed include benzene, toluene, xylene, l,l,l-trichloroethane, carbon tetrachloride, chlorofonn and a host of other aromatic hydrocarbon, aliphatic hydrocarbon and halogenated aliphatic or aromatic hydrocarbons which are well known in the art as solvents. It is not necessary that the volatile solvent be present, as the aerosol propellant acts as a solvent in the present composition. When a solvent other than the aerosol propellant is present, it may be present in an amount up to about 98,95 parts of volatile solvent per part of grease. In this situation, from about 0.05 to about 99 parts of an organic aerosol propellant may also be present per part of grease. The preferred range of organic aerosol propellant per part of grease is from 0.l to 0.8 parts of the propellant. It is also preferred to have from about 0.22 to about L0 percent zinc by weight based upon the weight of the grease of due naphthenate present in the aerosol mixture.
Grease compositions of the present invention have been found to be useful for lubricating zippers, nuts and bolts, water closet linkages, hinges on automobiles, homes and other buildings, clothes pulleys, sticking valves on brass instruments, automobile engine exhaust pipe bypass valves, garage door tracks, body jacks, ball connector hitches used in pulling trailers, steel bearings in bench type gliders, roller chains on machinery and trunk locks.
The following examples are illustrative of the practice of my invention and are not intended for purposes of limitation. All parts are by weight unless otherwise indicated.
The catalyst which was used in the following examples was prepared by dissolving one part by weight of chloroplatinic acid hexahydrate in ten parts of octyl alcohol and heating the solution at 70 to 75 C at 25 millimeters for 16 hours during which time all water and hydrogen chloride was removed. The pressure was then reduced to millimeters to remove all unreacted octyl alcohol. At the end of this time a product was obtained which was a dark, reddish-brown liquid soluble in alcohols, acetone, benzene, hexane, xylene, toluene and other common solvents. Chemical analysis of this mixture showed it to contain 3.5 atoms of chlorine per atom of platinum and 0.035 gram platinum per gram of the mixture.
EXAMPLE 1 An allylated product of the formula:
I)J N 3):
H() CH OH I): H cH=GHg V was prepared by dissolving 424 g. l mole) of 4,4'-methylenebis-2,6-ditertiarybutylphenol in an equal weight of toluene and an equal weight of ethyl alcohol. One thousand grams of a solution containing l l2 g. of potassium hydroxide in ethyl alcohol was made and slowly added to the phenol to provide the stoichiometric equivalent of the phenolic hydroxyl groups. A brilliant purple solution resulted which, when dried, showed no evidence of phenol and tested completely for complete conversion to the potassium phenylate. An additional equivalent amount of ethyl alcohol was added and 1.5 moles of allyl chloride was slowly introduced to the reaction mixture, which was refluxed for 2 hours at 70 C. All solids were filtered from the reaction mixture and the product was washed and stripped. Infrared analysis showed that the phenolate had been converted to phenol and that the allyl group was in place. Nuclear magnetic resonance evidence pointed to a replacement of one tertiary butyl group on one of the two aryl reaicals by an allyl radical.
To a reaction vessel was added 44.2 parts of a liquid trimethylsilyl chain-stopped methylhydrogenpoly-siloxane of the formula:
To this mixture was added 0.032 part of catalyst and 6.25 arts of a 50 percent toluene solution of the allylated product. The reaction system was set at reflux at 75 C at a vacuum of 100 mm Hg. taking any water present in the overhead ofi' to an azeolrope trap. The reflux was maintained for l hour. The system was then converted to atmospheric pressure reflux and 7 l .4 parts of decene-l was charged to a decene feed facility. The reaction mixture was then heated to 95 C and 0.016 parts of catalyst was added. Air addition into the reaction mixture was then started at a rate of 0.040 cubic feet per hour, per 100 pounds of the reaction mixture. The decene-l feed was ad justed at such a rate so as to feed the entire 7 l .4 parts over a 2- hour period. A 5 C rise in batch temperature was noted after 10 minutes and the air flow was reduced to lll0th of the initial rate. The reaction mixture was cooled so as to maintain a batch temperature of I05 C. Reduced air flow was maintained for I00 minutes and then stopped. At this point, an additional 0.008 parts of catalyst was added. At the end of the 2- hour decene-l addition, an additional 0.008 parts of catalyst was added and agitation was continued for an additional 2 hours. The system pressure ww then reduced to mm Hg. and light ends were stripped from the system, while the temperature was being'increased to l$0 C. When C was reached, the pressure was further reduced to 20 mm Hg. and this pressure was held for l hour with the nitrogen sparge. The product was then filtered through a diatomaceous earth filter. The product is again stripped at 280C at l0 mm Hg. with a nitrogen sparge for an additional hour and then refiltered through diatomaceous earth. The base oil produced had the average unit formula:
H0 CH CH ahsflCw uhJ Q Q sio."
To 705 parts of the base oil and 353 parts of lithium myristate in a grease kettle were added 25 parts of a polyether of the formula,
and 0.9 parts of finely ground lithium hydroxide. The mixture was stirred and heated to 240C and maintained at that temperature for 10 minutes with stirring. The mixture was then cooled at the rate of 1 C per minute to C and 14.4 parts of N-phenyl-alpha-naphthylamine were added and the slow cooling was continued to I50 C. At this temperature, an additional L962 parts of the base oil, 529 parts of lithium myristate and 2 parts of finely ground lithium hydroxide were added. Mixing was continued and the batch was cooled to room temperature. The composition was then milled twice through a Morehouse mill with a 5 mil gap to make a base grease. Using the base grease, a series of greases were prepared containing 0, is, l, 2, 3 and 5 percent zinc naphthanate by the following procedure. The base grease was stirred and heated and the zinc naphthanate was added at 70 C. The zinc naphthenate was then melted and dispersed in the base grease. The grease was cooled and milled through an homogenizer.
To show the protection afforded by the above greases, a 1 percent sodium chloride solution in water was allowed to slowly run (3 mil per minute) over a steel panel l X 4 inches) at a l5 angle and the time required for the first occurrence of rust to appear is taken as the end point.
The following are the results of the tests (run at room temperature). The zinc naphthenate used contained 14.5 percent Zll'lC.
% Zinc as Time to Zinc Naphthenate Rust in Grease (in seconds) EXAMPLE 2 into a grease kettle was put 13.6 parts of lithium myristate. To the grease kettle was then added 27.2 parts of the base oil, described in Example 1, together with 0.75 parts of a polyether of the formula,
HO(CQIIL(O)IID(CSHQO)JIH and 0.03 parts of finely divided lithium hydroxide. The ingredients were mixed well and heated to 240 C keeping the mixture under nitrogen. The mixture was maintained at 240 C with mixing for 30 minutes then slowly cooled to 170 C at which time 0.42 pans of N-phenyl-alpha-naphthylamine were added. The slow cooling was continued to 150 C at which point 0.06 parts of finely divided lithium hydroxide and 30.3 parts of the base oil were added. The composition was milled well in a Morehouse mill, returned to the grease kettle and 0.75 parts of lithium myristate, 6.4 parts of the base oil, 0.24 parts of lithium hydroxide and 1 part of zinc naphthanate were added. The composition was stirred and heated to 70 C to insure that the zinc naphthenate was melted and dispersed. The composition was then cooled and milled through a homogenizer mill. The product will be referred to in the remainder of this example as the bme grease.
To 3 parts of the base grease was added 47 parts of 1,1,1- trichloroethane and 50 parts of propellant. The propellant consisted of 22 percent of vinylchloride, 39 percent of monofluorotrichlorornethane, and 39 percent of difluorodichloromethane. The composition was then packaged in a typical aerosol can. An aerosol can filled with the composition was then given to each employee of the General Electric Silicone Products Department that requested one, with a suggestion that the employee report any significant usefulness which he found for the product. Uses which were reported by the employees included miter box corrosion inhibition, lubrication of rifles and shot guns, lubrication of electric clocks, lubrication of zippers, lubrication of nuts and bolts, lubrication of water closet linkages, lubrication of automobile door and home door hinges, lubrication of clothes pulleys, lubrication of springs on baby carriages, lubrication of automobile exhaust pipe bypass valves, lubrication of tracks on garage doors, lubrication of body jacks, lubrication of ball connector hitches for trailers, lubrication of steel bearings in glider lounges, lubrication of roller chains on machinery, lubrication of trunk locks, and the lubrication of extruder bolts.
EXAMPLE 3 To a reaction vessel was added 300 parts of a liquid trimethylsilyl chain-stopped polymethylhydrogen-siloxane of the formula,
To this mixture was added 0.00125 parts of chloroplatinic acid hexahydrate and 28.8 parts of an allylated product of the formula,
Ds I)J 110- -CH--- OH (CHI): CHrCI-I CH;
The addition took place over a 0.5 hour period and during the addition the temperature of the reaction mixture was maintained at 100 C. Heating was then discontinued and 683 parts of decene-l was added alowly to the reaction mixture over a l-hour period, during which time the temperature was maintained at C by the exothermic reaction resulting from the addition. After complete addition of the decene-l, heat was applied to the flask to maintain the temperature at l00' C for an additional thirty minutes to insure that all Sil'l was totally reacted and then the reaction product was vacuum stripped at 282 C and 10 mm Hg. using a nitrogen purge. This resulted in a base oil of the average unit formula:
Since 0.0148, the ratio of the t-butyl hydroxy aryl radicals to silicon atoms, is less than 1 in 62 and there are 62 silicon atoms per polysiloxane molecule, it is apparent that the composition described by the above average unit formula comprises a blend of products within the scope of formula 1, in which the majority of the polysiloxane molecules contain one R radical and a minor amount of the polysiloxane molecules do not contain an R radical.
To 705 parts of the base oil and 353 parts of lithium myristate in a grease kettle were added 25 parts of a polyether of the formula:
and 0.9 parts of finely divided lithium hydroxide. The mixture was stirred and heated to 240C and then slowly cooled at a rate of 1 C per minute to 170 C. To the mixture was added 14.4 parts of N-phenyl-alpha-naphthylamine and the cooling was continued to C. At this temperature, 1.962 parts of the base oil, 529 parts oflithium myristate and 2 parts of finely divided lithium hydroxide were added. Mixing was continued and the batch was cooled to room temperature. The product was then milled twice through a Morehouse mill with a 5 mil gap to make a base grease. To one fraction of this base grease was added 0.145 percent zinc as zinc naphthanate. The zinc naphthanate containing grease was prepared by stirring and heating the base grease to 70 C at which temperature the zinc naphthanate was added, melted and dispersed in the grease. The grease was then cooled and milled through a homogenizer. The corrosion resistance imparted by the grease was then measured using the test described in Example 1. For the steel panel with no grease at all applied, 125 seconds elapsed before rust appeared; when the grease without the zinc naphthanate was applied to the steel panel, it required 630 seconds for rust to appear and when the grease containing 0.145 percent zinc as zinc naphthanate was applied to the steel panel, 1,200 seconds elapsed before rust began to appear on the steel panel.
EXAMPLE 4 To a base oil of the average formula,
i i (CHI)ISlO (Sic SiO Sl(CHi)| uHn to H:
CH I H was added 353 parts of lithium myristate. The mixture was stirred and heated to 240 C and then cooled slowly at a rate of 1 C per minute to C. To the mixture was then added an additional 1.938 parts of the base oil and 529 parts of lithium myristate. Mixing was continued and the batch was cooled to 70 C. At this temperature, 30 parts of zinc naphthenate were added and melted and dispersed in the grease. The grease was then cooled and milled through a homogenizer. The corrosion resistance of the grease measured according to the test outlined in Example 1 was 675 seconds.
EXAMPLE 5 To L000 parts of a base oil the average formula:
(EH1 (CHihSiO S[i sworn i n so was added 196 parts of lithium myristate. The mixture was stirred and heated to 240 C and then slowly cooled at the rate of 1 C per minute to 150 C. At this temperature, 984.8 parts of base oil and 284 parts oflithium myristate were added. Mixing was continued and the batch was cooled to room temperature. The grease was then milled twice through a Morehouse mill with a 5 mil gap to make a base grease. To the base grease was added 20 parts of zinc naphthanate and the grease was heated to 70 C with stirring to melt and disperse the zinc naphthenate. The grease was then cooled and milled through a homogenizer. The corrosion resistance of the grease measured according to the test outlined in Example I was 600 seconds.
EXAMPLE 6 To 708 parts ofa base oil of the average unit formula:
I (CIimHiO sio SMCIh);
U it a:
was added 353 parts of lithium myristate. The mixture was stirred and heated to 240 C and then slowly cooled at a rate of lC per minute to 150 C. At this temperature, 1,938 parts of the base oil and 529 part os lithium myristate were added. Mixing was continued and the batch was cooled to room temperature. The grease was then milled twice through a Morehouse mill with a 5 mil gap to make a base grease. The base grease was heated to 70 C and with the stirring 30 parts of zinc naphthenate were added, melted and dispersed in the grease. The grease was then cooled and milled through a homogenizer. The corrosion resistance of the grease measured according to the test outlined in Example l was 400 seconds.
EXAMPLE 7 To 708 parts ofa base oil of the average unit formula,
C Ila C H; $11: C H; (CH;);SiO SiO SiO SiO SiO Si(CH3):
l l CuHza l0 ni- 3i v CHHIT a 20 M 1 Morehouse mill with a 5 mil gap to make a base grease. To the base grease heated to C was added 30 parts of zinc naphthenate. The zinc naphthenate was dispersed in the grease by continued heating and stirring. The grease was then cooled and milled through a homogenizer. The corrosion resistance of the grease measured according to the test outlined in Exam le 1 was 4,200 seconds.
What l cIaim is:
l. A silicone grease comprising on a weight basis:
1. from about 59 to about 98 percent of a polysiloxane fluid having a viscosity of about 10 centistokes to about l00,000 centistokes of the formula:
where the sum of(m n +p+ q) has a value offrom 2.002 to 3.0, n has a value of from 0.50 to 1.95, in has a value of from 0.5 to L0, p has a value of from 0 to 0.5, q has a value of from 0 to V4 (m n +P). R is an alkyl radical containing from six to 20 carbon atoms; R'is a t-butyl-substituted hindered hydroxyaryl radical; R is selected from the class consisting of lower alkyl radicals, cycle-alkyl radicals having live to seven carbon atoms in the ring, mononuclear and binuclear aryl radicals, mononuclear aryl lower alkyl radicals, and halogenated derivatives of the above radicals;
2. from about 2 to about 35 percent of a thickener;
3. from about 0.01 to about 2 percent of zinc as zinc naphthenate.
2. The composition of claim I further characterized by from about 0.02 to about I percent of zinc being present as zinc naphthenate.
3. The composition of claim 2 further characterized by the R radical of the polysiloxane fluid containing from about eight to about l2 carbon atoms.
4. The composition of claim 3 further characterized by the thickener being selected from the class consisting of lithium myristate and lithium stearate.
5. The composition of claim 1 further characterized by the grease being aerosol dispensable and containing an aerosol propellant.
6. The composition of claim 1 further characterized by the grease being aerosol dispensable and being dissolved in a volatile solvent and containing an organic aerosol propellant.
7. The composition of claim 1 further characterized by the grease being aerosol dispensable and being dissolved in from about 0 to about 98.95 parts of volatile solvent and containing from about 0.05 to about 99 parts of an organic aerosol propellant per part of grease.
8. The composition of claim 7 further characterized by the grease containing from 0.1 to 0.8 parts of an organic aerosol propellant per part of grease.
9. The composition of claim 8 further characterized by the grease containing from about 0.02 to about l.0 percent, by weight based upon the weight of the grease of zinc as zinc naphthenate.
10. The composition of claim 1 further characterized by the grease being aerosol dispensable and being dissolved in from about l to 99 parts ofa volatile solvent, placed in a container and pressurized to l5 to lOO pounds per square inch gauge pressure with an inert gas.
11. The composition of claim 7 further characterized by the grease constituting from i to 10 percent of the total mixture of grease, solvent and organic aerosol propellant.
12. The composition of claim 7 further characterized by the grease constituting from 2 to 5 percent of the total mixture of grease, solvent and organic aerosol propellant.
Dedication 3,669,884.-J0/m H. Wright, Elnora, N.Y. METHYL ALKYL SILICONE GREASE CONTAINING ZINC NAPHTHENATE. Patent dated June 13, 1972. Dedication filed J an. 26, 1972, by the assignee, General Electric Company, consenting. Hereby dedicates to the Public the portion of the term of the patent subsequent to Nov. 3, 1987.
[Oficz'al Gazette J anuary 16', 1973.]
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|U.S. Classification||508/213, 252/389.52|
|International Classification||C08L83/04, C10M169/00, C10M171/00, G04B31/08|
|Cooperative Classification||G04B31/08, C10M2207/121, C10M2227/061, C10N2210/01, C10N2270/00, C10N2220/02, C10N2240/02, C10M2229/053, C10M2209/104, C10M2201/12, C10N2210/03, C10M2201/042, C10M2205/14, C10N2250/08, C10N2240/06, C10M2209/105, C10N2250/10, C10M2229/048, C10N2250/121, C10M2229/047, C10M2290/10, C10M2229/046, C10N2210/00, C10M2215/066, C10M2207/128, C10M2207/129, C10M2201/103, C10N2210/04, C10M2215/102, C10M2201/105, C10M2207/141, C10M2207/16, C10M171/005, C10M2229/045, C10M2201/041, C10M2209/106, C10M2201/063, C10M2201/062, C10M2207/125, C10N2210/02, C10M2209/107, C10M2207/122, C10M7/00, C10M2201/065, C10M2205/022, C10M2215/227, C10M2201/05, C10M2201/066, C10M2215/065|
|European Classification||G04B31/08, C10M7/00, C10M171/00E|