DE927889C - Water-resistant greases - Google Patents

Description

The invention relates to a further improvement in the composition of water-resistant lubricating greases according to German patent 821 989, which have a corrosion-preventing effect through further additives.
It has been found that the water resistance of lubricating greases according to German patent 821 989 can be significantly improved by adding a further component consisting of an aliphatic dicarboxylic acid substituted by alkyl or alkenyl groups with at least 2 carbon atoms between the carboxyl groups, or an anhydride Amide or an ester of such a compound with an aliphatic alcohol, the dicarboxylic acid, the anhydride, the amide or the ester having at least one hydrocarbon group having 5 to 36 carbon atoms. These dicarboxylic acid derivatives not only increase the water resistance of the lubricating greases under consideration here in a hitherto unexplained manner, but they also give the lubricating greases improved corrosion properties without adversely affecting the lubricating grease structure.

The dicarboxylic acids preferred according to the invention are succinic acids, which are represented by alkyl and Alkenyl groups with 10 to 24 carbon atoms are substituted.

Alkylated succinic acids can be easily prepared by reacting condensed maleic anhydride with various olefins or olefin mixtures, in particular mono-olefins, preferably at 150 to 250 ^0th The

Standing alkenyl succinic anhydrides can then be hydrated to obtain the free alkenyl succinic acids which are used as such for admixture with the lubricating oil. or can be hydrogenated first to form the saturated alkyl succinic acids. One method of making these substituted dicarboxylic acids is described in U.S. Patent 2,055,456. With regard to the boiling limits of the suitable olefins, there do not seem to be any critical limits which impair the corrosion-preventing properties of the alkyl succinic acids produced with them. In general, the normal boiling range of the distillate fraction between 250 and 400 ⁰ should lie.

Suitable olefins for the condensation reaction

with maleic anhydride can be prepared by cleaving a specific heavy oil, or lower-boiling olefins can also be polymerized to form higher-boiling olefins. Particularly useful are the normal olefins which are obtained in the vapor phase cracking of paraffin at temperatures of about ⁰ 560, although branched olefins may be used. "The olefins may be of either the primary or the secondary or the tertiary type. Other suitable condensation products may can be obtained by using maleic acid or fumaric acid, citraconic acid, itaconic acid, mesaconic acid, glutaconic acid, methylitaconic acid or their anhydrides as starting materials instead of maleic anhydride ... ....

The possible alkyl and alkenyl di carboxylic acids can be in the form of their .Anhydrides, as free acids, aliphatic mono-, di- or polyamides or aliphatic esters are used, and for the preparation of the amides also Hydroxyl derivatives of the amines can be used.

The succinic acid derivatives used with preference include, in particular, the alkenylsuccinic acids, in which the alkenyl groups contain 10 to 24 carbon atoms, such as dodecenyl, Hexadecenyl, octadecenyl succinic acid or mixtures thereof, as they are by condensation from maleic acid with mixed olefinic hydrocarbons.

These alkenyl succinic acids can be hydrogenated can be converted into alkyl succinic acids, giving the corresponding series of Alkylsuccinic acids obtained in which the alkyl group Contains 10 to 24 carbon atoms. This series therefore includes such typical representatives as Tridecyl, pentadecyl, and heptadecyl succinic acids.

Suitable alkylsuccinic acid derivatives are, for example, octadecy / succinic anhydride and octadecenylsuccinamic acid and dodecenyl succinamic acid anhydride.

If esters are used, they are preferably derived from aliphatic alcohols with 1 up to 24 carbon atoms. Examples of suitable esters are the methyl esters of octadecenyl succinic acid, the 2-ethylhexyl ester of hexadecyl succinamic acid and the dodecenyl esters of decenyl succinic acid.

The aliphatic hydroxyl or aliphatic to be used in the compositions according to the invention Mercapto compounds are those described in German Patent 821,989.

The amount of the hydroxyl or mercapto compounds and the succinic acid derivatives should be preferred between about 1 and 70 percent by weight of the gel and suitably between 20 and 50 percent by weight. The quantities of additives are calculated on the basis of the total lubricating grease between 0.2 and 10 percent by weight, preferably ι to 5 percent by weight.

When summarizing the compositions described above, they contain the lubricating greases have the following quantity ranges of their components:

Lubricating oil

Inorganic gelling agent ... hydroxyl or mercapto

link

Dicarboxylic acid derivative

Weight percent of the composition

60 to 98 ι to 20

0.2 to 10 o, 2 to 10

"" It has been found that, albeit the above Listed levels of ingredients in most Cases deliver satisfactory results, but a sharper limitation is possible when calculating the addition of hydroxyl compound and succinic acid derivative according to the amount of inorganic Gels instead of the entire grease composition. Accordingly, they are preferred Compositions calculated up to 20% by weight of the inorganic gel on the total grease, and 1 to 70 percent by weight and more, especially 20 to 50 percent by weight, of the inorganic gel contain hydroxyl compound and dicarboxylic acid derivative.

The following examples illustrate those achievable by the present compositions Advantages.

Example i

A mineral lubricating oil was ground with 5 weight percent of a silica alcogel, which was prepared by displacing the water from a silica hydrogel. During milling, 2.4 weight percent of the triglyceride of 12-oxystearic acid was added to the mixture and the ingredients were milled to form a grease. A similar grease with no added glyceride was also made. After grinding, the greases were heated for about 1 hour at a temperature of about 150 to 210 ^0th The grease, which only contained silica and lubricating oil, was in the presence of

rapidly decomposed in boiling water. ' A sample of the Lubricating grease made with silicon dioxide and lubricating oil was made by adding ι percent by weight Octadecenylsuccinic acid, calculated on the grease, modified. This too Similarly, grease decomposed rapidly in the presence of boiling water. That Silica grease containing the glyceride additive showed satisfactory toughness opposite to boiling water. A fourth grease that has the same amounts of both Glyceride addition as well as octadecenylsuccinic acid also showed satisfactory stability in the presence of boiling water. The four greases described above were then subjected to a rolling stability test under the following conditions: 74g of the grease and 14 grams of water was rolled in a Shell Roll Tester and examined at periodic intervals until the grease has a micro-penetration of Had reached 230 tenths of a millimeter. It has been found that the silica grease, which contained no additives, failed almost immediately. The silica grease that only contains octadecenyl succinic acid contained failed in about 1 hour. The grease that contains the glyceride additive failed in 12 hours, while the grease with both additives failed the sample ■ Lasted 52 hours before failing.

Example 2

Silica hydrogel was used to form a silica-alumina hydrogel treated with aluminum sulfate. A grease was made containing 5 percent by weight silica-alumina hydrogel by dehydrating the hydrogel with ethyl alcohol, incorporating the gel into a mineral oil and incorporating the alcohol evaporated. Three greases have been made: Grease A did not contain any additives. Grease B contained 2 percent by weight of the triglyceride of 12-oxystearic acid. Grease C contained ι percent by weight of octadecenylsuccinic acid and 2 percent by weight of the triglyceride of 12-oxystearic acid. Each of the three greases contained 5 percent by weight of the silica-alumina gel. For comparison, two of the lubricating greases from Example 1 were also tested. Pattern D was the grease from Example 1, which contained the glyceride of 12-oxystearic acid, and Sample E was the grease from Example 1 which contained both the glyceride and the octadecenyl succinic acid contained. The lubricating greases described were tested using a Layer of the fat spread on a steel strip, which is then located in a test glass Water has been immersed. The tasting glass was placed in a steam room and on a regular basis Checked for oil separation at intervals. The numbers in the table below show the heating time in hours required to cause oil separation.

template composition hours
heated A- Silica-aluminum oxide I. B. Silica-aluminum oxyd -f glyceride 16 C. Sih'cmmdioxyd-Aluminum- oxide + glyceride + Bern stinic acid derivative longer than 31 D. Silicon dioxide -f- glyceride .. I. E. Silicon dioxide -f- glyceride + Succinic acid derivative .. 5

Example 3

template Gelling agent Dicarboxylic acid derivative Hydroxyl
link I. Aluminum oxide Methyl ester of octa 12-oxystearin decenyl succinic acid acid 2 Silicon dioxide Hexadecenyl succinic i, 2-decamethylene amic acid glycol 3 Silicon dioxide Dodecenyl amber Stearyl alcohol acid anhydride 4th Aluminum oxide Octadecenylitaconic acid Aluminum. 12-oxystearate

When greases are made by adding 5 percent by weight of the listed gelling agents, ι percent by weight of the succinic acid derivative and 2 percent by weight of a hydroxyl compound dispersed of the type described above in 92% by weight of the mineral lubricating oil, the compositions obtained were found to be excellent in resistance against exposure to hot water. If the hydroxyl compound is from any of the compositions is omitted, the result is that the grease which is mixed with the remaining three components have been prepared, against exposure to cold water is extremely sensitive and breaks down immediately on contact with hot water. Lubricating greases, which contain the gelling agent, mineral oil and hydroxyl compound, if they are also have some resistance to the action of cold water, however rapidly decomposed in the presence of hot water.

Example4

A mineral oil-based lubricating grease was produced which contains 6 percent by weight silica alcogel, ι percent by weight glycerol monostearate and ι percent by weight octadecenyl succinic acid contained. A similar grease was made with the omission of the octadecenyl succinic acid. The first grease was found to have three times more resistance to hot ίο featured water as the second-named grease.

Claims (5)

Patent claims: i. Water-resistant lubricating grease according to German patent 821 989, characterized by a further content of 0.2 to 10 percent by weight, calculated on the total lubricating grease, an aliphatic dicarboxylic acid substituted by alkyl or alkenyl groups with at least 2 carbon atoms between the carboxyl groups or an anhydride, an amide or an ester of such a compound with an aliphatic alcohol, whereby the dicarboxylic acid, the anhydride, the amide or the ester has at least one hydrocarbon group having 5 to 36 carbon atoms contains. 2. Lubricating grease according to claim i, characterized in that that the aliphatic dicarboxylic acid substituted by alkyl or alkenyl groups with at least 2 carbon atoms between the carboxyl groups or the derivative such an acid in an amount of ι to 5 percent by weight, calculated on the all grease is present. 3. Lubricating grease according to claim 1 and 2, characterized in that the by alkyl or Alkenyl group-substituted aliphatic dicarboxylic acid an alkyl or alkenyl succinic acid is, in particular one which has at least one alkyl or alkenyl group Has 10 to 24 carbon atoms, such as octadecenyl succinic acid. 4. Lubricating grease according to claim 1 to 3, characterized in that the inorganic Gelling agent in an amount of 2 to 10 percent by weight, calculated on the total Grease is present. 5. Lubricating grease according to claim 1 to 4, characterized in that the hydroxyl or Mercapto compound in an amount of ι to 5 percent by weight, calculated on the total Grease is present. 1 509 504 5.55