DE1111758B - Method of making clay-gelled waterproof lubricating grease - Google Patents

Description

The known, by means of a clay gelled lubricating greases against the harmful effect of water through the simultaneous incorporation of cationic surfactants, such as amines, amides, aminoamides and ammonium salts.

According to the so-called "direct transfer method", the aqueous clay dispersion is combined with the lubricating oil in the presence of the waterproofing agent concerned, preferably mixed under such conditions that the mixture is divided into an aqueous and an oily phase separates. After removing the aqueous component, the oily component is removed by evaporation of the residual water Made practically completely anhydrous, whereupon the dehydrated product for the purpose of homogenizing the Expediently subjected to a shearing treatment for lubricating grease and to improve its consistency will.

When using clays that exchange bases as a gelling agent, one can also initially through Reaction with an ammonium salt to produce a so-called "onium tone" and this after the Drying and grinding are incorporated directly into a lubricating grease.

According to one proposal, particularly oil-soluble agents are suitable as water-proofing agents Aminoamides, which are obtained by heating fatty acids with 16 to 20 carbon atoms to 200 to 225 ° C for 1 to 1 hour per molecule, of which at least 50 percent by weight has at least 1 double bond per Contain molecule, and a mixture of PoIyäthylenpolyaminen with a content of 20 to 80 percent by weight diethylenetriamine and a remaining proportion of an average molecular weight from 250 to 400 in the ratio of 0.4 to 0.5 equivalents of fatty acids per equivalent of polyamine mixture have been received.

It has been found that lubricating greases of the type described above, which have a waterproofing, contain cationic surfactant when stored in moisture or water vapor containing atmosphere tend to harden, especially in the parts that form the surface of a Closest to the container. This hardening can be of considerable disadvantage for the consumer, who needs a grease with a certain consistency, if the grease at the time of Due to prolonged storage, it no longer has the same consistency as it was at the time of use Buy it.

According to the invention, these disadvantages can be addressed. Method for producing one with clay
gelled waterproof grease

Applicant:

Shell International
Research Maatschappij NV, The Hague

Representative:

Dr. K. Schwarzhans and Dr. E. Jung, Patent Attorneys, Munich 19, Romanplatz 9

Claimed priority:
V. St. v. America October 27, 1958

Gerard Paul Caruso, New Orleans, La. (V. St. A.),
has been named as the inventor

side by going to the preformed one containing the clay and the surfactant Lubricating grease mixture which contains no more than 5 percent by weight of water, nor 0.25 to 1 percent by weight Oil-soluble amino amides are added by the reaction of fatty acids with 14 to 22 carbon atoms per molecule with a polyethylene polyamine mixture of 20 to 80 percent by weight of polyamines with 2 to 3 nitrogen atoms per molecule and the remaining proportion of polyethylene polyamines with an average molecular weight of 200 to 500 in the ratio of 0.3 to 0.6 equivalents of fatty acids per equivalent of said polyamine mixture have been received.

The aminoamides are preferably used in amounts of 0.5 to 0.8 percent by weight, calculated on the Grease added. It is particularly important for achieving the desired technical effect Meaning that the amino amides are added to the mixture of the components forming the lubricating grease at a point in time be added when the water content thereof is less than 5% by weight as that

109 649/363

explain the examples given below in more detail. The usual, for the purpose of increasing the On the other hand, cationic surface-active compounds applied to water resistance are generally used incorporated directly into the aqueous clay dispersion together with the lubricating oil, even if one used for this purpose aminoamides of the same type as are suitable according to the invention. on however, hardening of the finished lubricating greases cannot be prevented in this way.

Further improvements in resistance to setting can be achieved by after the addition of the oil-soluble amino amides, the lubricating greases are subjected to a heat treatment 0.5 to 8 hours at 50 to 100 ° C, preferably for 1 to 4 hours at 65 to 90 ° C, subjected. An even further improvement in the hardening resistance can be achieved by the dehydrated grease is not only given the oil-soluble aminoamides in the above-described manner Manner incorporated, but also added 0.05 and 0.25 percent by weight of water.

Any hydrophobic lubricating oil can be used for the lubricating greases according to the invention, although Mineral oils are preferred. However, you can also use synthetic lubricating oils, such as silicones, diesters, Use phosphates or polyethers or mixtures of such substances, if desired in a mixture with a mineral oil.

The clays used as gelling agents expediently have a relatively large base exchange capacity and the ability to swell relatively strongly in water. Bentonite clays, like Hectorite, are preferred.

The amount of clay contained in the greases can vary depending on the consistency of the desired lubricating grease vary within wide limits. But it is generally between 2 and 20 percent by weight, calculated on the total mixture.

The amount of the waterproofing agent contained in the grease can also be wide Limits vary and is generally between 40 and 100 percent by weight, calculated on the tone.

A preferred group includes the same amino amides as are used to avoid hardening the greases are used. Another preferred group of waterproofing agents comprises that Aminoamides described in U.S. Patent 2,623,852 are described and are generally referred to as aminoamides of polyaminooxy compounds, which contain at least 3 amino nitrogen atoms or oxy groups per molecule (added together). It must be emphasized, however, that these types of aminoamides, albeit in terms of improvement the water resistance of the clay greases works satisfactorily, but no protection against it Provides hardening of the finished grease mixture as a result of absorption of water. The in the invention Process of adding oil-soluble aminoamides to preformed grease blends are derived from polyethylene polyamine mixtures, preferably 20 to 80 percent by weight of ethylene diamine and / or contain diethylenetriamine, while the high molecular weight polyethylene polyamines from tetraethylene pentamine and its higher homologues exist.

The mixture of high molecular weight polyethylene polyamines is normally used as a bottom product the production of ethylenediamine obtained. A typical mixture of high molecular weight polyethylene polyamines, diluted with 25% diethylenetriamine, has the composition given in Table I.

Table I.
ίο

Carbon 51.5 percent by weight

Nitrogen 34.3 weight percent

Hydrogen 11.6 percent by weight

¹ S oxygen 2.5 percent by weight

Total basicity 1.98 equivalents

to 100 g, corresponding to 27.7 weight

percent nitrogen

Active nitrogen 81%

Primary amines 1.20 equivalents

_a5 on 100 g

Tertiary amines 0.30 equivalents

per 100 g

specific weight
at 25 ° C 0.995 to 1.020

Viscosity 75 to 250 cP

Equivalent weight 42.5 to 47.5

The fatty acids to be used to produce the aminoamides should be 14 to 22 carbon atoms contain per molecule, preferably 16 to 20, and very particularly advantageously 17 to 19 carbon atoms. The aminoamides can be either liquid or solid, depending on the degree of saturation of the used Acids. Mixtures of fatty acids are preferably used which have an essential Have proportion of unsaturated acids, but it is also possible to use saturated acids, such as stearic acid use. A mixture of fatty acids in which at least 50 percent by weight of the mixture is made up Acids with at least one double bond per molecule, provides aminoamides, which in the normal production temperature of the lubricating greases are liquid. It is even cheaper if at least 85 percent by weight of the fatty acids contain double bonds; they can have either one or two double bonds have per molecule. Linoleic acid and oleic acid as well as linolenic acids are preferably used. The acids found in tall oil are particularly suitable for the formation of the aminoamides. The fatty acids and the polyamines are used in a ratio of 0.3 to 0.6 equivalents, preferably 0.4 to 0.5 equivalents of the fatty acids converted for each equivalent of the polyethylene polyamine. The fatty acids and the polyamines can be used at any temperature that is sufficient for amide formation, be made to react. At the higher temperatures one conversion can at least some of the amido groups in imidazoline or glyoxylidine compounds. As part of the present invention include all of these products

summarized under the name aminoamides. The reaction temperature generally varies from 125 to 250 ° C for ₃ preferably 190-225 ° C. The reaction times are generally between 0.5 and 16 hours and preferably between 1 and 4 hours.

The preferred method of making grease blends in accordance with the present invention is the direct transfer process, the essential characteristics and bases of which have already been mentioned above have been explained.

The addition of 0.25 to 1 percent by weight of the aminoamides described above is not done before the water content of the grease components is less than 5 percent by weight and preferably less than 0.5 percent by weight. This can be done in a simple manner by taking the aminoamides stirred into the grease either before or after the shear treatment.

As mentioned earlier, further improvement can be achieved by incorporating from 0.05 to 0.25 percent by weight of water after the grease constituents have dehydrated. This mode of operation has proven to be particularly advantageous because in a normal atmosphere of about At 30Vo moisture, most grease mixtures according to the invention absorb up to about 0.15% water and thereby change their consistency significantly, d. H. get harder. Hence it will be in the In practice, this amount of water is added to the grease and the penetration with the help of the Adjust the clay content to the desired value so that the grease retains its consistency, even if it is subsequently exposed to a humid atmosphere.

Yet another improvement in resistance to hardening under the action of a humid atmosphere is achieved by using known corrosion inhibitors, such as sodium nitrite, or antioxidants such as phenyla-naphthylamine, in minor amounts (generally 0.25 to 1 percent by weight of the finished Grease mixture). The following examples illustrate the practical implementation of the invention.

example 1

A grease blend was prepared from hectorite clay, 60 percent by weight of the clay of amino amides as a waterproofing agent, and a mineral lubricating oil of medium viscosity. The preparation was carried out by dispersing the clay in water to form a dilute suspension and mixing the aminoamides and the oil with the suspension mentioned. The deposited water layer was separated. The remaining sludge was then dewatered in a kettle equipped with a stirrer to obtain a grease mixture containing about 0.1% by weight of water. The mixture was then divided into three portions. A portion was poured into a jug and immediately sealed. This sample is referred to as Part A. 0.75 percent by weight of the same amino amides (calculated on the grease) were added to the two remaining portions B and C. Sample C of the mixture was heated in a sealed jug in an oven at 200 ° C for 2 hours. The remaining portion B was allowed to cool in the container. Corresponding amounts of water were added to the three samples. As can be seen from Fig. I, the addition of water to Part A leads to excessive hardening of the grease. The addition of water to sample B showed that the presence of aminoamides, which had been added after the dehydration, almost completely prevented hardening during the subsequent addition of water. Finally, the relative insensitivity to water in the case of sample C shows that the combination of the additional addition of aminoamides with a heat treatment protects the lubricating grease substantially against a change in consistency due to the presence of water.

Example 2

In order to show that the stabilization in terms of consistency when water is added is not caused by the amides added in large amounts per se, samples were also prepared in which the amino amides were added to the grease components while the originally large amounts of water were still present before the drainage was carried out. Fig. II shows the results obtained by this procedure. The solid curve shows roughly the same numerical values as the curve for portion A in FIG. II. Excessive hardening occurred when water was added. However, all samples examined in this series showed the same degree of hardening, even if the original aminoamide content was increased in the manner indicated (dashed curve). A comparison of the numerical values given in FIG. II with those according to FIG. I shows without a doubt that the aminoamides must be added in two successive stages, the last stage being added in smaller amounts (0.25 to 1%) to one The point in time comes after the water has already been largely removed from the grease.

Example 3

Table II contains the numerical values showing the effect of the water content at the time of the second Show the addition of the amino amides to the grease-forming components. The changing crowd the water content depends on the point in time at which the second addition takes place. If the entire Amount of water in which the clay is initially dispersed, even at the time of the second addition is present, the grease hardens during subsequent dehydration and subsequent minor dehydration Excessively strong water additions. If the second addition of the aminoamides is made after the water that separates out after the sludge is formed is finally removed formed lubricating grease is not as sensitive to moisture absorption as in the first case, but still not satisfactory. However, if the grease before the second addition of the aminoamides was practically completely dried, occurred when small amounts of water were subsequently added practically no increase in penetration. The decisive one clearly emerges from these experiments Importance of the time of the second addition of the waterproofing agent.

Table II

The condition of the grease at the second addition of aminoamides

Water content of the grease g / 100 g ASTM Walk penetration

at 0.1% added water

at 1.0% added water

modification
of penetration

Immediately after the sludge has formed

Mud freed from water

Sludge, dried at 115.6 ° C

5 minutes later

10 minutes later

15 minutes later

20 minutes later

After 10 minutes at 115.6 to 137.8 ° C, addition of NaNO ₂

0.75% aminoamides added 0.5 minutes later

0.75% aminoamides added 15 minutes later

180

27

0.108 0.093 0.072 0.063 0.076

0.11 0.06 312

342

320
321
313
324
347

365
336

198

257

275
273
271
290
312

325
316

114
85

45
44
42
34
35

40 20th

Example 4

The data contained in Table III illustrate the effect of a first addition of amino amides to the grease and the effect of a second addition of the amino amides on water sensitivity and penetration, respectively. It can be seen from the results that a significant benefit is achieved by a subsequent second addition of amino amides to the essentially dry grease components.

Table III

To the sound total quantity
of the sound in Change in penetration 0.75%
Aminoamides mud
added VIVlJ 4- VAi ¹ J 1111
Grease with the water content of
0.1 to 1.0 »/ 0 added Amount of
Aminoamides to dry Weight Weight initially Grease * percent percent 23 of the sound 5.0 20th 60 5.2 59 14th 70 5.6 64 80 42

35

40

45

^:: All samples were after the second Aminoamidzu- _"0 would be 2 hours at 93.3 'C heated.

Example 5

Lubricating greases have been made to reduce the effects of antioxidants such as phenyl-a-naphthylamine, and anti-corrosion agents such as sodium nitrite (both in the presence and absence of an addition of Aminoamides). The values obtained are given in FIG. III. A test of this figure shows that both phenyl-a-naphthylamine (in the Drawing abbreviated as PAN) as well as sodium nitrite to the consistency of a lubricating grease without the second addition of aminoamides has little effect. The presence of phenyl-a-naphthylamine or sodium nitrite improves the hardening of the lubricating grease with subsequent addition of water in Quantities of parts of a percent do not. The same greases were made for comparison with a second addition of 0.75 weight percent of aminoamides to the virtually anhydrous made grease-forming ingredients. From the figure it can be seen that the so produced Lubricating greases were essentially insensitive to subsequent water addition.

The aminoamides used in the previous examples were prepared as follows:

The mixture of polyamines as listed in Table I was 2 hours with a sufficient Amount of tall oil acids sufficient to form amides with 42% amino groups Heated to 210 ° C.

Claims (10)

PATENT CLAIMS: 1. A process for the preparation of a clay gelled and with a cationic surface-active agent, in particular based on oil-soluble, water-insoluble aminoamides made waterproof lubricating grease, characterized in that one to the preformed, the clay and the surface-active agent containing lubricating grease mixture, which is not contains more than 5 percent by weight of water, 0.25 to 1 percent by weight of oil-soluble aminoamides are added, which are obtained by reacting fatty acids with 14 to 22 carbon atoms per molecule with a polyethylene polyamine mixture of 20 to 80 percent by weight of polyamines with 2 to 3 nitrogen atoms per molecule and the remaining proportion Polyethylene polyamines having an average molecular weight of 200 to 500 in a ratio of 0.3 to 0.6 equivalents of fatty acids per equivalent of the polyamide mixtures mentioned have been obtained. 2. The method according to claim 1, characterized in that the preformed lubricating grease mixture contains no more than 0.5 percent by weight of water. 3. The method according to claim 1 or 2, characterized in that the oil-soluble aminoamides be added in an amount of 0.5 to 0.8 percent by weight. 4. The method according to claim 1 to 3, characterized in that at least 50 percent by weight of the fatty acids in the oil-soluble amino amides contain at least one double bond per molecule. 5. The method according to claim 4, characterized in that the fatty acids are tall oil acids are. 6. The method according to claim 1 to 5, characterized in that the lubricating grease according to Addition of the oil-soluble amino amides to a heat treatment for 0.5 to 8 hours and at 50 to 100 ° C is subjected. 7. The method according to claim 1 to 6, characterized in that the lubricating grease according to the Add the oil-soluble amino amides for 1 to 4 hours which is subjected to a heat treatment at 65 to 90 ° C. 8. The method according to claim 1 to 7, characterized in that the dehydrated lubricating grease 0.05 to 0.25 percent by weight of water can be added. 9. The method according to claim 1 to 8, characterized in that the clay is a bentonite Sound is. 10. The method according to claim 1 to 9, characterized in that the lubricating grease is subordinate Quantities, preferably 0.25 to 1 percent by weight, of a known corrosion inhibitor, z. B. sodium nitrite, and a known antioxidant, e.g. B. Phenyl-a-naphthylamine, can be added. 1 sheet of drawings © 109 649/363 7.61