DE1091687B - Grease - Google Patents

Description

GERMAN

The invention relates to lubricating greases made with the aid of an ester of a saccharide and a monocafboxylic acid of high molecular weight and an alkaline earth salt of a lower fatty acid are thickened.

It is known from US Pat. No. 2,700,022 to crankcase lubricating oils which are for use in Petrol engines are intended to use esters of mono-, di- or trisaccharides with aliphatic carboxylic acids, the 10 or contain more carbon atoms in the molecule to suppress the formation of varnish-like deposits clog in the engine. These known lubricating oils must of course be liquid, since they are called crankcase lubricating oils are to be used, and can be used as additives such. B. esters of sugars such as erythrose, threose, xylose, Arabinose, rhamnose, mannose, galactose, glucoheptose, fructose, sorbose, glucodecose, lactose, sucrose, Maltose, cellobiose, raffinose, rhamninose or melicitose, with aliphatic carboxylic acids such as capric acid, Undecylic acid, lauric acid, oleic acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, Naphthenic acid or higher carboxylic acids obtained from vegetable oils, in amounts of about Contain 3 to 20 percent by weight.

The German patent specification 955 890 describes liquid lubricating oils based on mineral oil, which are used as corrosion protection agents an addition of 0.1 to 10 percent by weight of higher fatty acid esters of polyoxyalkylene ethers of hexites of the general formula

Grease

R- (OC ₂ H ₄ ) ";

(OR '),

contain, where R is the hydrocarbon chain of hexitol, preferably sorbitol, R 'is the acid residue of a fatty acid with 12 to 18 carbon atoms, preferably lauric or oleic acid, η a number from 6 to 12, χ a number from 4 to 6 and where the number of carbon atoms in (OR ') is greater than 6 ».

It has now been found that greases with excellent resistance to phase separation can be obtained which, in view of their non-toxicity, are suitable for all those applications where a non-toxic Lubricant is required when using lubricating oils with esters of disaccharides and high molecular weight fatty acids and thickened with alkaline earth salts of fatty acids with 2 to 6 carbon atoms.

The lubricating greases according to the invention based on a predominant portion of a lubricating oil are characterized by a content of an ester of 1 mol of a disaccharide and 1 to 3 mol of a C ₁₂ - to C ₃₂ fatty acid in amounts of 5 to 30 percent by weight and an alkaline earth salt of a C ₂ - to C ₆ fatty acid in amounts of 5 to 40 percent by weight.

Applicant:

Esso Research and Engineering Company, Elizabeth, N.J. (V. St. A.)

Representative: E. Maemecke, Berlin-Lichterfelde West,

and Dr. W. Kühl, Hamburg 36, Esplanade 36 a,

Patent attorneys

Claimed priority:
V. St. v. America March 28, 1958

Arnold J. Morway, Clark, N.J.,

and Walter E. Waddey, Westfield, N. J. (V. St. A.),

have been named as inventors

The new lubricating greases can be used in food processing plants such as dough mixers, Conveyors, filling, packaging and canning plants.

The disaccharide of the ester can be sucrose, maltose, lactose or cellobiose. The monocarboxylic acid residue can differ from fatty acids with 12 to 32, z. B. derive 16 to 24 carbon atoms in the molecule. Here include naturally occurring or synthetic, substituted and unsubstituted, saturated and unsaturated Fatty acids. Examples of such acids are palmitic acid, stearic acid, dioxystearic acid, behenic acid, Montanic acid, linolenic acid, linoleic acid, arachidic acid, ricinoleic acid, oleic acid, hydrogenated fish oleic acids, Sebum acids, etc.

The esters that can be used as thickeners include mono-, di- and tri-esters. Special examples are Sucrose monostearate, sucrose distearate, sucrose tristearate, maltose dipalmitate, maltose monolaurate, corn-tosedimelissate, Cellobiose monooleate, sucrose monotalgic acid ester, etc. are particularly preferred because of them readily available in large quantities of sucrose mono- and distearate.

As alkaline earth salts of C ₂ - to C ₆ fatty acids, for. B. the calcium, barium or strontium salts of acetic acid, propionic acid, butyric acid, valeric acid or caproic acid can be used. Calcium acetate is particularly preferred for this purpose because it produces a solid, high dropping point lubricating grease with anti-wear properties and extreme pressure properties.

009 629/394

The production of the lubricating greases according to the invention can, for. B. be done by initially adding 5 to 30 percent by weight Disaccharide esters dispersed in a lubricating oil. For this purpose the mixture of ester and oil is used heated with stirring until the ester goes into solution in the oil. This generally occurs at around 138 to 160 ° C. The alkaline earth metal salt can then be added in the form of an aqueous solution and the mixture can then be dehydrated. However, it is more expedient to produce the alkaline earth salt itself in the mixture of ester and oil. This is easily possible by using an alkaline earth base, e.g. B. lime, with the desired acid, e.g. B. acetic acid or acetic anhydride. The mixture can also be heated from the outside as required, what depends on which salt is to be produced and whether the salt is to be in the form of a hydrate or not. When the salt ζ. B. Calcium acetate is and when there is a small amount of water and the The reaction temperature is kept below about 82 to 93 ° C, then the dihydrate is formed. Will however If the same reaction mixture is heated to more than 82 to 93 ° C, the monohydrate is formed while one receives anhydrous calcium acetate at temperatures of about 149 ° C. Depending on the intended use, you can Hydrates or the anhydrous form may be desirable. When used at low temperatures, the hydrates provide the strongest thickening effect, while the anhydrous form has a lesser thickening effect, however is more favorable for higher temperatures. According to the invention, the oil thickened with the ester can be about 5 to 40, e.g. B. add 10 to 35 weight percent alkaline earth salt.

The lubricating oil used in the lubricant of the present invention can be a mineral lubricating oil, a synthetic lubricating oil, or a mixture of such lubricating oils. The synthetic lubricating oils which can be used according to the invention include dicarboxylic acid esters (e.g. di-2-ethylhexyl sebacate), esters of glycols (e.g. the C ₁₃ oxo acid diester of tetraethylene glycol), complex esters (e.g. those obtained by reacting 1 mole of sebacic acid complex esters formed with 2 moles of tetraethylene glycol and 2 moles of 2-ethylcaproic acid), formals, silicones, carbonic acid esters, polyglycols and other synthetic lubricating oils known per se.

Various other lubricating oil additives can also be made in amounts from about 0.1 to 10.0 percent by weight on the total weight of the lubricant. Examples of such additives are sludge inhibitors, such as calcium petroleum sulfonate, corrosion inhibitors such as sorbitan monooleate, pour point depressants, Colorants, other grease thickeners and the like.

example 1

10.0 parts by weight of sucrose distearate in 55.6 parts by weight of a mineral lubricating oil of a at 98.9 ° C measured viscosity of 8.76 cSt by heating to 149 ° C with stirring. This The base material is left to cool. 13.4 parts by weight of hydrated lime are added to the mass, which has cooled to 38 to 49 ° C added and dispersed thoroughly in the ester dispersion until a smooth slurry is formed Has. Then 20.0 parts by weight of glacial acetic acid are added with stirring. A solid fat structure forms almost immediately. The reaction temperature rises to 82 ° C, and the mass is stirred until the temperature is too high begins to sink. Then the temperature is increased to 104 ° C by external heating. At this point of the In the process, a part is deducted from the product for investigation. The rest of the grease will be on Heated to 160 ° C and then allowed to cool while stirring. As soon as the mass has cooled to 93 ° C., 1.0 part by weight of phenyl-a-naphthylamine is used as an oxidation retarder added, whereupon the fat is allowed to cool further to room temperature.

Example 2

A fat according to Example 1 is produced at 160 ° C, However, the ingredients are used in other proportions and the distearate is used Monostearate is replaced.

For comparison purposes, a grease with calcium acetate as the only thickener, i.e. H. without the ester, made as follows: 13.4 percent by weight hydrated lime and 65.6 percent by weight mineral lubricating oil (Viscosity 8.76 cSt at 98.9 ° C.) are intimately mixed with one another to form a slurry. Then 20.0 percent by weight of glacial acetic acid are slowly added with stirring, the temperature rising to 82 ° C rises. The mass is then heated until the temperature has risen to 104 ° C, whereupon a sample is taken will. The rest of the mass is heated to 160 ° C to completely dehydrate the calcium acetate. When it cools down, phenyl-a-naphthylamine is added at 93 ° C., whereupon the mass rises Room temperature is allowed to cool.

The various compositions and their physical properties are as follows Table compiled.

Composition and properties of lubricants

04 ° C 16O ⁰ C example j 104 ° C 16O ⁰ C 2 1 10.0 10.0 160 ° C - - 20.0 20.0 5.0 20.0 20.0 13.4 13.4 13.4 13.4 1.0 1.0 10.0 1.0 1.0 55.6 55.6 6.7 65.6 65.6 excellent chnetes, 1.0 soft, no smooth, equal 77.3 half Fat- moderate fat excellent, fluid structure smooth, equal moderate fat

Composition, percent by weight

Sucrose monostearate

Sucrose distearate

Glacial acetic acid

Hydrated lime

Phenyl-a-naphthylamine

Mineral lubricating oil

(Viscosity 8.76 cSt at 98.9 ° C)

properties

Appearance

1 091 ÖÖ7

Table (continued)

104 ° C 160 ° C

example

2 160 ⁰ C

104 ° C

Drop point, ⁰ C

ASTM penetration at 25 ° C, mm / 10

Resting penetration,

Walk penetration after 60 thrusts
Walk penetration after 100,000 hits

Water solubility

Oxidation according to Norma Hoffmann * ...

Lubrication duration, hours ***

(121 ° C - 10,000 rpm)

> 260> 260

225! 250 275 I 275 280 290

Insoluble j Insoluble 320

Alpine pasture test, weights

Wear test in the four-ball device
(1 800 rpm - 10 kg load - 75 °
1 hour) Scratch diameter, mm.

1300

Hours**
15th

> 260

275

300

330

Insoluble

414

1300
Hours**

0.26

* Hours until the oxygen pressure drops by 0.35 kg / cm ² . ** Acts as a lubricant when the test is finished.

*** Testing machine from the Anti-friction Bearing Manufacturer - National Lubricating Grease Institute.

As can be seen from the table above, Example 1 (104 ° C) shows that from the with sucrose distearate and Calcium acetate monohydrate thickened oil is a high-melting fat with good pressure absorption capacity and low values for oxidation and wear arise. Example 1 (160 ° C) shows that anhydrous Calcium acetate has practically the same effect and that these lubricating greases at higher temperatures have a long lubrication time. Example 2 (160 ° C) illustrates the use of anhydrous calcium acetate together with sucrose monostearate. The comparative samples A (104 ° C) and A (160 ° C) show the Effect of calcium acetate monohydrate and anhydrous calcium acetate as the only thickening agent.

For the production of lubricants within the meaning of the invention, the others mentioned above can also be used Esters, e.g. B. Cellobiosetrioleate can be used in place of sucrose monostearate.

Claims (3)

Patent claims: 1. Lubricating grease based on a predominant portion of a lubricating oil, characterized by a content of an ester of 1 mol of a disaccharide and 1 to 3 mol of a C ₁₂ - to C ₃₂ fatty acid in amounts of 5 to 30 percent by weight and an alkaline earth salt of a fatty acid with 2 to 6 carbon atoms in amounts of 5 to 40 percent by weight. 2. Lubricating grease according to claim 1, characterized in that the ester is a sucrose mono- or diester of a C ₁₆ - to C ₂₄ fatty acid, preferably sucrose mono- or distearate. 3. Lubricating grease according to claim 1 or 2, characterized in that the salt is calcium acetate, preferably anhydrous calcium acetate. Documents considered: German Patent No. 955 890; U.S. Patent No. 2,700,022. 1 009 629/39 + 10.60