DE2111793A1 - Grease compsn - contng a polysiloxane a polyether and a base - Google Patents

Abstract

Grease compsn. comprises (a) 61 - 98% wt. of a fluid methyl polysiloxane of viscosity 10 - 100,000 cS having formula (CH3)nSiO 4-n/2 where is 2.002 - 2.2, (b) 2 - 35% wt. of a grease thickening Li soap of a fatty acid, (c) 0.01 - 5.0% wt. of a polyether of formular A-O-(CxH2xO)nB or A- O-(CxH2xO)n- y-(Q)z (in which A and B are H, 1 - 12C alkyl, 5 - 7C cycloalkyl, mononuclear and binuclear aryl or binuclear aryl lower alkyl where the alkyl grps. attached to the aromatic nucleus contain a total of is not >5C, Q is a residue of a polyhydric initiator radical contg. >=2 OH gps. selected from ethylene glycol, glycerol, trimethylolpropane and other polyhydric alcohols with 2 - 6 OH, x is 2 - 4, y is 2 - 10, z is 1 - 5) the polyether having mol.wt. 300 - 200,000, (d) a metal base in amount to maintain the grease alkaline.

Description

Polysiloxene-containing fat preparation The invention relates to improved ones Fat preparations that contain a methylpolysiloxane, and a method for Manufacture of these preparations. In particular, the invention relates to organopolysiloxane fat preparations, wherein the organic substituents on the polysiloxane are all ylethyl groups, as well as a process for the production of the preparations, whereby it is prevented that Form soap lumps in the finished fat preparation.

Organopolysiloxene-containing fats and fat preparations are per se known and already became known as lubricants, dielectric agents, sealants and high vacuum used. These organopolysiloxane-containing fats are because of their great stability against heat, their water repellency and the viscosity properties and dielectric properties at low and high temperatures are valuable.

Up to now it has been extremely difficult to obtain fats containing a liquid silicone (polysiloxane) contained, whose substituents were exclusively methyl groups, in hors a-tion To manufacture a soap of a higher fatty acid by means of a melting process. The soap and the liquid; of are incompatible with each other because the side The liquid is not absorbed and lumps of soap form in the fat. I) ies bothers in the mechanical processing of the j'ebts and results in an end product that bad silicone bleeding properties and a bad one has stability at higher temperatures and during storage.

To solve the problem of lump formation in 'silicone fats was found des long-chain alkyl groups and aryl radicals instead of the methyl groups when polysiloxane can be introduced, what better compatibility with Lethal soaps of higher fatty acids result. The proposed theoretical reason for the occurring compatibility lies in the fact that the large organic residues of the polysiloxanes adsorbed by the long alkyl groups of the fatty acid soap or be dissolved in the soap. While the substitution of methyl groups by higher Alkyl groups and aromatic radicals in the polysiloxane used for fat production served the purpose of compatibility, had some of the substituted Residues have a detrimental effect on other desirable properties, in particular on the breaking apart of the organopolysiloxane molecule as part of the fat preparation in case of thermal exposure.

Other residues gave good lubricating properties at high temperatures at the expense of the properties at low temperatures.

The aim of the invention is to create improved organopolysiloxane fat preparations, the most affordable Properties of previously known fat preparations keep them, but are also easy to manufacture and inexpensive.

These and other objects of the invention are provided by improved methylpolysiloxane fat formulations dissolved, which contain a small lung of a polyether. It was found ds.9s the presence of a small amount of a polyether in the case of methylpolysiloxane-containing Fat preparations that contain a higher fatty acid lithium soap, a significantly improved compatibility between the lithium soap and the higher fatty acid and the polysiloxane component. This prevents the formation of large agglomerates the soap during the production of the fat and allows the production of a fat preparation, which has favorable properties. The fat preparation according to the invention is best consisting essentially of (1) 61 to 98% by weight of a liquid polysiloxane, its organic Substituents are methyl groups, (2) 2 to 35% by weight of a lithium soap of a higher one Fatty acid with 10 to 22 carbon atoms, such as a lithium soap made from lauric acid, Myristic acid, palmitic acid or stearic acid, preferably myristic or stearic acid, (3) 0.01 to 5.0% by weight of a polyether and (4) a base such as lithium hydroxide, in an amount sufficient to maintain the alkaline properties of the fat lot.

The methylpolysiloxanes used according to the invention are per se known and generally described in U.S. Patents 2,469,388 and 2,469-390. This type of isethylpolysiloxane can be characterized as having it units has the average formula (CH3) nSi04n (I) 2, where n has a value of 2.002 to 2.2 has. Although, according to the invention, any liquid methylpolysiloxane falling under formula I can be used in the method according to the invention, it is preferred that the liquid has a viscosity of about 10 cSt to about 100,000 cSt as measured at 25 ° C.

The liquid ethylpolysiloxanes of the formula I can contain siloxane units of various types and compositions, such as trimethylsiloxane units and dimethylsiloxane units as such or in combination with monomethylsiloxane units. The only requirement is that the ratio of the various Siloxane units is selected so that the average composition of the liquid Copolymers in the context of formula I is.

One component of the fat preparation according to the invention is the thickener for fats that are known per se. The invention contemplates the use of lithium soaps of the higher fatty acids with 10 to 22 carbon atoms in addition to the carboxyl carbon atoms to form a fat preparation with the desired consistency. The expression In the context of the invention, “fat” is intended to encompass fat-like substances that have consistencies that range from easily flowable fabrics to fabrics that are practical show no flow. The consistency of the fats according to the invention depends on the Amount of thickener used, the particular thickener used and the particular liquid polysiloxane that is used. Examples more suitable Thickeners are the lithium soaps of higher fatty acids with 10 to 22 carbon atoms in addition to the carboxyl group, such as tauric acid, myristic acid, palmitic acid, stearic acid and preferably myristic and stearic acid soaps of lithium.

While those used in the fat preparation according to the invention Amounts of thickener are not critical and vary within wide limits the particular consistency desired in the end product can vary, it has been found that the amount of thickener is usually from about 2 to 35% by weight, preferably from about 5 to about 25% by weight, based on the total weight of the fat preparation, fluctuates.

A critical feature of the fat preparations according to the invention is however, the amount of polyether present. For a satisfactory dispersion of the thickener In the polysiloxane, as has been found, the polyether must be present in an amount the approximately 0.01 to 5.0% by weight, based on the weight of the fat preparation, and is preferably Q, 1 to 2.0 wt .-%. If less than Q.01 wt. Polyether are present, it has been found to be very difficult to remove the thickener in the To disperse fat and there is also a tendency that the polysiloxane fluid. bleed more from the fat preparation. When the amount of polyether in the fat preparation is above 5.0% by weight, the weight loss of the fat is at temperatures above 150 ° C (3000P) so large that, as has been found, the fat is suitable for many purposes is no longer suitable.

the polyethers used according to the invention in combination with the polysiloxane oils are polymeric alkylene oxides and / or polymeric alkylene glycols and can be given by the formulas AO (x °) n B (11) and are represented, where A and B are hydrogen atoms, alkyl radicals with f to 12 carbon atoms, cycloalkyl radicals with 5 to 7 carbon atoms in the ring, mono- and binuclear aryl radicals or mononuclear alkyl-substituted aryl radicals, the alkyl groups bonded to the aromatic nucleus not more than 5 carbon atoms in total contain. A and B also represent ester-forming groups which contain 2 to 12 carbon atoms. A and B can be the same or different. If there is more than one radical A per molecule, the radicals A can be identical or different. Q denotes a residue of a polyvalent initiator residue which contains at least 2 hydroxyl residues, such as ethylene glycol, glycerine, methylolpropane and other polyhydric alcohols with 2 to 6 hydroxyl groups, x is a number with the value 2 to 4, n is a number with the value 4 to 2000, y has a value from 2 to 10, and z has a value from 1 to 5.

In particular, ask. the residues A and B residues from the following group represents: hydrogen, alkyl radicals with 1 to 12 carbon atoms, z..B. Methyl, ethyl, Proyl, butyl or octyl radicals; Cycloalkyl radicals with 5 to 7 carbon atoms in Ring, e.g., cyelopentyl, cyclohexyl or cycloheptyl radicals; single and double core Aryl radicals, e.g., ihenyl, naphthyl or biphenyl radicals; mononuclear aryl radicals with lower alkyl substituents, the alkyl groups on the aromatic nucleus as a whole contain no more than 5 carbon atoms, e.g. benzyl, phenylethyl or phenylpropyl radicals and Ester groups with 1 to 12 carbon atoms, such as the residues of fatty acids, their Hydrogen carboxyl is removed, e.g., an acetate, propionate or octoate group; Hydroxyether groups derived from glycols such as butylene glycol or octylene glycol and formed by esterification with a hydroxyl group of a non-fatty acid Groups, e.g. propylphosphate, octylsulphonate or butylsulphate groups.

The polyethers can be made from the various alkylene oxides, e.g. ethylene oxide, higher 1,2-epoxides (such as 1,2-propylene oxide), alkylene glycols (e.g. ethylene glycol) and mixtures thereof. The products obtained can be polyoxyalkylene diols or polyalkylene glycol derivatives, i.e. the terminal hydroxyl groups may be remain or during or after the polymerization reaction e.g. by etherification or esterification with the formation of mono- or diether groups or eliminated by mono- or diester groups or a combination of such end groups be, with certain favorable properties of the polymer mixture obtained as the end product be awarded.

For example, A and / or B can be selected from the following in formula II or III Radicals can be selected: alkyl radicals which form a dialkyl polyether (z -13. Iibutylheptaoxypropylene diether); ester-forming groups which form alkyloxyalkylene esters (e.g.

ButylpentaoxÜnrolenacetat) and hydrogen, which forms polyglycols (e.g. polyethylene glycol).

Further examples of polyethers which can be used are those whose "oil part", ie the section - (CxO) ñ of the formulas II or III, is derived from basic units such as the following oxides: sec-propylene oxide sec-butylene oxide tert-butylene oxide or is derived from those basic units which are derived by dehydration of alkylene glycols to form the following units: Ethylene oxide - (CH2 - CH2-- O) -propylene oxide - (CH2-CH2-CH2-O) -butylene oxide - (CH2-CH2-CH2 -CH2-O) polyethers which contain combinations of the basic units mentioned are, as has been found, very useful in accordance with the invention. A preparation which contains two different alkylene oxide groups can be produced, for example, by reacting a polypropylene glycol with ethylene oxide in the presence of boron trifluoride. This mixed polyalkylene glycol can optionally be reacted with an alkanol such as butanol to form the monobutoxy ether of the mixed polyalkylene glycol. A number of these Polyslkyenoxides are commercially available, for example under the. Trade names "Ucon" (Union Carbide Corporation) and "Pluracol" (Wyandotte Chemicals Corporation).

The molecular weight of the polyether oils used according to the invention can range from 300 to 200,000 with molecular weights from 400 to 20,000 preferred are.

Ä1; tc2ser the compounds or components mentioned can be found in the conventional additives for silicone greases are present according to the fat preparations according to the invention be. Examples of such additives are antioxidants such as amines, e.g., N-phenyl-α-naphthylamine; Corrosion inhibitors, e.g. zinc naphthenate and extreme pressure additives such as selenium disulfide and molybdenum disulfide.

There are a number of methods for making the present invention Preparations. According to the preferred method, the liquid polysiloxane, the iiithiumseife 31s thickener, the polyether as a dispersant and a small amount of a finely ground base, such as lithium hydroxide, to a temperature Heated from 204 to 26000 (400-5000F), after which the fat preparation is brought to room temperature allowed to cool and then ground. Fat preparations according to the invention are especially for use as a lubricant in axle bearings of analog motors with high Current consumption suitable, which overheat, but exposed to extremely low temperatures are when they are not running.

The invention is illustrated in more detail by the following examples.

Example 1 A fat preparation was produced using a polydimethylsiloxane which had 2-trimethylsilyl end groups and a viscosity of 350 cSt, measured at 25 ° C., as the base liquid. To 540 g of lithium myristate and 30 g of a polyoxyalkylene polyol of the formula 1080 g of base liquid and C. 9 g of finely divided lithium hydroxide were added. The components were mixed thoroughly and heated to 24300 (4700F). The mixture was slowly cooled (0.8 ° C / min.) To 174 ° C (345 ° F) at which point 15 pounds of N-phenyl-α-naphthylamine and 1,36 grams of base oil were added with constant stirring. The slow cooling was continued and at 990C (2100Y) 1.5 grams of finely divided lithium hydroxide was added. The fat was still cooled to lisurnt temperature with constant stirring. The fat formed was ground three times in a Morehouse mill. Processing went very smoothly and very few clumps of lithium myristate conglomerates were formed upon mixing.

For comparison purposes, a fat was prepared in order to test the effect of the Polyether additive to determine the ease of processing. The fat was made in exactly the same way, but no polyether was added.

The processing brought about great difficulties because of the Formation of lithium myristate lumps during mixing. The lumps didn't go together with the remaining ingredients through the mill. in comparison of both fats showed that the polyether fat was a thicker, smoother fat and that the silicone oil showed much less tendency to separate from the fat.

EXAMPLE 2 To 540 g of a mixture containing 60% lithium stearate and 4% lithium palmitate, 1080 g of the base oil according to Example 1 and 0.9 g of lithium hydroxide, which had been pre-ground on a mash roll calender with a small amount of lithium stearate / lithium palmitate base oil mixture, were mixed and with continued stirring with 30 g of a polyoxyalkylene glycol of the formula offset.

The mixture was heated to 24600 (475 ° F) with constant stirring. The mixture was slowly cooled (0.8 ° C / min) to 1717400 (345 °) at which Place 15 g of N-phenyl-α-naphthylamine and 1365 g of base oil still under constant Stir was added. The slow cool down continued and at 10000 (212 ° F) a further 1.5 g of lithium hydroxide, which was pre-ground as above, was added and the fat preparation formed at room temperature still with constant stirring cooled down.

The fat formed was very smooth and few lumps came through Lithium soap conglomerates.

For the purpose of comparison, a fat was prepared that completely contained this fat but did not contain polyoxyalkylene polyol. Processing the comparison fat was very difficult and the fat was very lumpy from conglomerating Particles of lithium stearate and palmitate. Lots of the bigger hard lumps remained in the elective container and a thinner fat was obtained.

The fat produced containing the polyoxylalkylene polyol was much less prone to bleeding than the comparative fat, especially with higher temperatures.

Example 3 A fat preparation was made using of a trimethylsilyl-terminated polydimethylsiloxane and a viscosity of 100 cSt at 2500 as the base fluid.

To 540 g of lithium marristate and 30 g of a polyoxyalkylene polyol of the formula 1080 g of the base liquid and 0.9 g of finely divided lithium hydroxide were added. The components were mixed thoroughly and heated to 24300 (4700F). The mixture was slowly cooled (0.800 / min) to 17400 (3450F )7 at which point 15 g of N-henyl-a-naphthylamine and 1365 g of base oil were added with constant stirring.

The slow cool down continued and were at 9900 (2100F) 1.5 g of finely divided lithium hydroxide was added and the fat was under constant Stir cooled to room temperature.

The fat formed was milled three times with a Morehouse mill. The processing went very smoothly and there were few lumps on the ground the conglomerate formation of lithium myristate when mixed. A comparison fat was used to determine the effect of the polyether addition on the ease of the Processing made. The yett was made in exactly the same way, however no polyether was added. The processing was very difficult because of the education of lithium myristate lumps when mixing.

A comparison of the two fats showed that the polyather-containing fat was thick and smooth, while the comparative fat was thinner and the grinding jar was small Contained round balls like deer posts formed from lithium myristate.

The bullets did not go through the mill. You were so tough on that more severe than usual treatment would have been necessary to break it open.

Example 4 A fat preparation was produced using a poly-dimethyl silo with triniethylsilyl end groups and a viscosity of 350 cSt at 2500 as the base liquid. To 560 g of lithium myristate and 31.2 g of a polyether of the formula 1200 g of the base liquid and 1.0 g of finely divided lithium hydroxide were added. The components were mixed thoroughly and heated to 2430G (4700F). The mixture was slowly cooled (0.80C / min) to 17400 (345QF) at which point 20 g of N-phenyl-a-naphthylamine and 1740 g of base oil were added with constant stirring. The slow cooling was continued and at 9900 2100F) 1.0 g of finely divided lithium hydroxide and 440 g of lithium myristate were added and the fat was cooled to room temperature with constant stirring. The cured fat was ground three times in a Morehouse mill. Processing was very smooth and very little lump was formed due to the conglomerate formation of lithium myristate when mixed.

A comparison grease was used to determine the effect of the polyether additive Manufactured on the ease of processing. The fat was in exactly the same Wise, but made with omission of the polyether. Grinding was very difficult because of the presence of lumps of bíthium myristate that had previously formed and clogged the grinder inlet. A comparison of both fats showed Xass the polyether-containing Fe-tt was thicker and smoother and much less prone to separation of the silicone oil from the lithium myristate showed, especially at high temperatures. The comparison fat showed a lack of soap due to the lack of soap the impossibility getting a lot of the bigger lumps of soap through the grinder. That the polyether containing fat had the following properties: penetration (processed 60 times) 245 Bleeding in 24 h at 15,000 1.68 io evaporation in 24 h at 15,000 1.62.

The invention is broadly applicable to fat preparations, the polysiloxanes with methyl groups as substituents in combination with a lithium soap one higher fatty acid and 0.01 to 5.0% of a polyether and one for maintenance alkaline properties of the preparation contain the required amount of a base.

Claims (4)

P a t e n t a n s p r ü c h e 1. Am polysiloxane and a lithium soap of a higher fatty acid containing fat preparation that does not indicate that they are a.us (1) 61 to 9.3% by weight of a liquid methylpolysiloxane of the average formula (CH3) nSiO4-n 2 in which n has a value of 2.002 to 2.2, (2) 2 to 35% by weight of one Lithium soap of a fatty acid with 10 to 22 carbon atoms other than the carboxyl group, (3) 0.01 to 5.0% by weight of a polyether and (4) a base in one for maintenance alkaline properties of the preparation 2. Fat fry after Claim 1, d u r c h g e e n n e i c h n e t that (1) the liquid polysiloxane has a viscosity of 10 to about 100,000 cSt at 25 ° C, (2) the lithium soap, lithium myristate and / or lithium stearate, (3) the polyether in an amount of 0.1 to 2.0% by weight, based on the fat preparation, and (4) the base used is lithium hydroxide is. 3. Fat preparation according to claim 1 to 2, d a d u r c h g e K e n n 3 e i c h n e t that the lithium soap is lithium myristate. 4. fat preparation according to claim 1 to 3, d a d u r-c h g e k e n It should be noted that the polyether is in an amount of 0.1 to 2.0% by weight on the preparation.