HU195675B - Process for producing litium-calcium hybrid-base complex lubricating grease - Google Patents

Abstract

The lubricating grease comprises (%w/w): 5-12 lithium-12-hydroxy stereate, 0.4-1 monolithium borate, 0.1-2 alkaline earth metal soap, max. 7 known grease lubricant additives, gelling agents and inhibitors, made up to 100 with a hydrocarbon based grease oil.

Description

The present invention relates to a lithium-calcium mixed-base complex lubricating grease.

Lithium fats have been known for many years and are widely used. Known lithium-based fats are usually prepared from lubricating oil and lithium soap. Lithium soap is formed from high molecular weight fatty acids with lithium hydroxide. The lithium grease has the advantage of being water resistant, lithium soap is highly dispersible in lubricating oil and can be used at various lubrication points up to a maximum temperature of 120 ° C. Fats made from lithium 12-hydroxystearate are particularly useful because they are mechanically more stable than lithium fats made with appropriate soaps of conventional fatty acids.

However, in more difficult places temperatures higher than 120 ° C persist. Lithium complex greases with higher heat resistance properties have been developed to meet such demands.

U.S. Pat. No. 3,929,651 discloses modified magnesium lithium fat with a high melting point, wherein the soap-component oxic acid is lithium soap, the dithionic salt of dicarboxylic acid and the lithium salt of oxyaromatic carboxylic acid.

. U.S. Patent No. 2,425,161 relates to a lithium soap lubricating grease comprising aliphatic aliphatic esters of Hicns 12-hydroxystearic acid and a lithium salt of boric acid.

The salt component of the lubricating grease disclosed in German Patent 2,157,207 contains 12-hydroxystearic acid, salicylic acid, lactic acid or boric acid. .

The lubricating grease described in U.S. Patent Nos. 2,235,098 and U.S. Pat. No. 3,758,407 contains a soap component consisting of a lithium salt of 12-hydroxystearic acid and a monolithium salt of boric acid, as well as methyl salicylate.

Lithium fat according to U.S. Patent No. 4,376,060 contains polyhydroxy compounds in excess of lithium soap and lithium salt of boric acid, the essential components of which are polyhydroxy compounds,

The patents cited above are calcium soap. pan component.

A disadvantage of both standard lithium fats and the higher droplet lithium fats shown is that it has a gentle tendency to grease fats, i.e., oil extraction. The reason for this is that with conventional lithium greases, due to the free chain attachment of the lithium soap, the lubricating oil easily leaks from the resulting soap structure. In the case of modified lithium fats with two or three acid components, the soap component is poorly dispersed in the lubricating oil and therefore has an inadequate oil holding capacity.

Our invention is based on the discovery that 12-hydroxy-carcinoic acid, or. 12-hydroxystearic acid and linoleic acid vegetable oil are preferably sunflower or soya-bean oil soap oils, particularly preferably calcium soaps, which unexpectedly promote the formation of lithium 42-hydroxy stearate that is, its syneresis decreases. This is explained by the fact that the lithium-12 hydroxystearate VAT-based soap structure consists of straight, spirally twisted, thermoset fibrillary elements, which are built up by small, szincrézisét. / Syneresis refers to the tendency of the liquid in the lubricating grease to precipitate the lubricating oil, which may occur under certain circumstances, for example upon heating. MS 13184 /. *

In the process of the present invention, the lithium-calcium mixed-base complex lubricating grease is dehydrated by saponification of the starting materials, dewatering of the formed lithium calcium soap, complexation, cooling, cold-mixing, doping, hotnogenization.

Approximately 3 / 10ths of the lubricating oil used in the clap saponification process for heating the keto fat is heated to 60 ° C and the starting materials, i.e. at least 50% by weight of lithium hydroxide-lou , 12-hydroxystear-grade tea-grade vegetable oil «Kava or technical grade vegetable oil of the 12-hydroxy / tearic acid and lithioic acid groups, preferably sunflower or soybean oil and technical grade boric acid in aqueous solution. The mixture was warmed to 90'C and saponified for 2 hours.

The amount of lithium hydroxide monohydrate is not negligible in terms of the amount of starting materials used, have we found the lime hydrate to be particularly advantageous? in a small amount of 1,14, preferably 1,6 to 12,6% by weight of lithium hydroxide monol hydrate. The calcium soap formed from the lime hydrate and the saponified fatty acids unexpectedly exhibited the syneresis-lowering effect on the lubricating grease according to the invention only when used in such small amounts. When used in larger amounts, the lubricating grease of the present invention exhibits a rapid increase in syneresis and a decrease in its drop point.

Within the total soap content, the molar ratio of 12-hydroxystearic acid to boric acid is 1: 0.2 0.2 / preferably 1: 0.25. Boric acid has been reported in the literature as having "Organic compounds of hydroxyl tartrate containing hydroxylchlorothorphol / inannite on adjacent carbon atoms, invert sugar / easily formed complexes / Lengycl · Prostate deer: General and inorganic chemistry. Textbook publisher Budapest, 1954, /.

It has been found that boric acid also complexes with organic compounds containing a hydroxyl group on the secondary carbon atom (hydroxy stearic acids). For a boron atom, four hydroxystearic acids can be directly attached and one hydroxystearic acid is chain linked.

The oil and the lithium and calcium soap formed are dehydrated under two continuous heating, and approximately 4/10 of the lubricating oil is added in portions while the temperature of the mixture is increased to 205 ° C, then the heating is stopped and the remaining lubricating oil is added. While stirring, the whole was cooled to 180 ° C, then the stirring was stopped and the mixture was left at 180 ° C for 20 minutes. These operations are used to form the gel structure of the lithium-calcium mixed-base complex lubricating grease. The resulting lubricating grease is then mixed cold, the lubricating oil refining is added to a known amount of up to 7% by weight of known lubricating grease, homogenized and vented.

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As a lubricating oil component, all known ^- lubricating oil, preferably mineral oil-based, solvent-refined and paraffin-refined lubricating oil fines - can be used.

The lithium calcium light base complex lubricating grease is a waterproof lubricant with a high mechanical stability and can be used in central lubrication systems over a wide temperature range from -30 ° C to 140 ° C. With the addition of calcium soap, the fat structure of the complex of lithium-12-hydroxystearate and boric acid is well dispersed, thus significantly improving the oil-holding capacity of the lubricating grease. Improved oil storage capacity ensures that the lubricating oil does not escape from the lubricating grease during storage, so that a uniform lubricating grease is deposited on the lubrication point; , the lubricating grease provides a smooth lubrication, no hardening resulting from oil separation during use. In addition, the calcium soap addition advantageously improves the mechanical stability of the lubricating grease, which is advantageous because the grease soap's frame structure is not broken during use and thus the lubricating grease has a long life.

The following examples illustrate the preparation of lithium-calcium mixed base lubricating grease according to the present invention.

Example 1. Weigh 1560 kg of lubricating oil in the grease fryer. Heat to 60 ° C. 49.7 kg of lithium hydroxide monohydrate dissolved in 250 kg of water and 0.8 kg of lime hydrate suspended in 2.0 kg of water are added. Subsequently, 253.5 kg of technical grade 12-hydroxystearic acid and 18.0 kg of boric acid were dissolved in 100 kg of water. Then it is. the mixture was heated to 90 ° C and saponified for 2 hours. Upon completion of the saponification, the free alkali content of the mixture was adjusted to 0.01-0.25 NaOH by addition of 12-hydroxy stearic acid or lithium hydroxide (NaOH% expressed as free alkali according to MSZ 13181) and the system was dewatered. Subsequently, 2291 kg of lubricating oil refined petrol was added in portions. During the addition, the temperature of the mixture was raised to 20 ° C. When the temperature reaches 205 ° C, the heating is stopped and 874.0 kg of fine lubricating oil are added. The lubricating grease is then cooled to 180 [deg.] C. with stirring and allowed to stand at this temperature for 20 minutes without stirring. After resting, the lubricating grease obtained is mixed with cold, added as usual, homogenized, vented and removed.

The most important technical characteristics of the lithium-calcite mixed base lubricating grease prepared as described in the example are given in Table 1, while the test data of a conventional NLGI grade lithium-based grease are presented for comparison purposes.

Example 2

1560.0 kg of fine lubricating oil are weighed into the greasing apparatus and heated to 60 ° C. 49.7 kg of lithium hydroxide monohydrate dissolved in 250 kg of water and 0.8 kg of lime hydrate suspended in 2.0 kg of water are added. Next, 50.7 kg of sunflower oil, 202.8 kg of technical grade 12 hydroxyslear acid and 18.0 kg of boric acid are dissolved in 100 kg of water. Subsequently, the lubricating grease is prepared as described in Example 1, and its products are added, homogenized, vented and packaged in the usual manner. The major technical characteristics of the lithium calcium mixed base lubricating grease prepared as described in the example are given in Table 1.

Example 3

Weigh 1537 kg of lubricating oil in the grease fryer. Heated to 60 ° C

59.5 kg of lithium hydroxide monohydrate dissolved in 260 kg of water and 7.5 kg of lime hydrate suspended in 16.0 kg of water. Subsequently, 371.5 kg of technical grade 12 hydroxystearic acid and 19.0 kg of boric acid were dissolved in 40 kg of water. The mixture was heated to 90 ° C and saponified for 2 hours. After saponification, the mixture was checked and adjusted to 0.01 0.25% NaOH are then drain the system and then added portionwise 2237 kg of refined lubricating oil, while the system temperature was raised to 2O5 ^u C. When the temperature reaches 205C, the heating is stopped and 768 kg of lubricating oil is added. Subsequently, the mixture was stirred at I80 ° C with stirring and allowed to stand at this temperature for 20 minutes without stirring. After resting, the lubricating grease obtained is stirred cold, added in the usual way, homogenized, vented and removed. The most important technical characteristics of the lithium-calcium mixed-base complex lubricating grease prepared as described in the example are given in Table 2, comparing simultaneously. As an example, we present test data for a conventional NLGI grade 2 lithium-based grease.

Example 4

Weigh 537 kg of lubricating oil in a grease fryer. Heat to 60 ° C. added

59.5 kg of lithium hydroxide monohydrate dissolved in 260 kg of water and 7.5 kg of lime hydrate suspended in 16.0 kg of water. Subsequently, 297.3 kg of technical grade 12 hydroxystearic acid and 75.0 kg of sunflower oil and 19.0 kg of boric acid are dissolved in 60 kg of water. The lubricating grease is then prepared as described in Example 3, the products are added, homogenized, and remove it. The most important technical characteristics of the lithium carbine mixed base lubricating grease prepared as described in the example are given in Table 2.

Example 5

15 Weigh 1525.0 kg of cooking oil in a grease fryer. Heat to 60 ° C. added

120.6 kg of lithium hydroxide monohydrate dissolved in 400 kg of water and 8.8 kg of lime hydrate suspended in 16 kg of water. Thereafter, 692.5 kg of technical grade 12-hydroxystearic acid and 45.5 kg of boric acid were dissolved in 150 kg of water. The mixture was heated to 90 ^u C, saponified for 2 hours. After saponification, the pH of the mixture was checked and adjusted to 0.01 to 0.25 NaOH, and the system was dewatered and then 1900 kg of lubricating oil was added portionwise while the system was heated to 205 ° C. When the temperature reaches 205 ° C, the heating is stopped and 825 kg of fine lubricating oil are added. The mixture was then cooled to 180 ° C with stirring and allowed to stand at this temperature for 20 minutes without stirring. After resting, the prepared lubricating grease is stirred cold, and is added as usual.

-3195 675 is homogenized, vented and removed.

The most important technical characteristics of the lithium-calcium mixed-base complex lubricating grease prepared as described in the example are given in Table 3, while comparing the data of a conventional NLGI grade 3, 5-lithium-based grease.

Example 6

1525.0 kg of lubricating oil fin is weighed into the greasing apparatus and heated to 60 ° C.

120.6 kg of lithium hydroxide inonohydrate dissolved in 400 kg of water and 8.8 kg of lime hydrate suspended in 16.0 kg of water. Then 138.5 kg of sunflower oil and 554.0 kg of technical grade 12-hydroxystearic acid are added,

45.5 kg boric acid dissolved in 150 kg water. Subsequently, the

The lubricating grease was prepared as described in Example 5, and the product was added, homogenized, vented and disassembled in the usual triode. The major technical characteristics of the lithium calcium mixed base lubricating grease prepared as described in the example are given in Table 3.

Table 1

Features Conventional lithium fat  Example 1 Example 2 Cseppcncspont C 182 220 220 above above Penetration at 25 ° C, 0.1 mm before breaking 315 312 320 After 60 fractures 320 315 324 10 «after fracture 339 318 328 Penetration has become. 0.1 mm 19 3 4 NLGI grade 1 1 1 Holds free alkali. f.aOH% 0.09 0.14 0.16 Micro penetration, 25 ° C, 0.1 mm after 60 fractures '318 312 319 2 after Shell Roll rolling 336 3) 6 322 Micropcnetration has become. 0.1 mm 18 4 · 3 Colloidal stability, load% 9.81 N, 30 min. 22.7 14.3 15.6 Synthesis, t%, at 80 ° C 5 3.4 3.9 140 ° C 1 1.6 6.9 7.6 Contact load on four-ball device, N 1570 1962 1962 Graduate degree 0 1 0 1 0 1 Lubrication is lower back O / 1 ra, ( 30 30 30 Tendency to tear, 16.3 “C After 6 hours, t% 12.7 5.2 4.9

l - weight

Table 2

Features conventional lithium fat Example 3 Example 4 Melting point, ° C 2Ό0 220 220 above above Penetration at 25 ° C 0.1 mm before breaking 262 267 272 After 60 fractures 265 268 273 IO ⁴ after fracture 289 27S 280 Penetration has become. 0.1 mm 24 7 7 NLGI grade • 2 2 2 Holds free alkali. NaOH ', / 0 0.1 0.18 0.19 M i k rope 1 le t warm>, 25 ° C- on, 0.1 mm 60 fracture after 262 268 275 2h Shell Roll Cylinder- after staying 288 265 .278 Micropenetration has changed- 0.1 mm 26th -3 3 Colloidal stability, t% 9.81 N load, 30 min . 19.7 10.8 E, 12.8 Synthesis at 100 ° C t% , 5 1.4 1.9 140 ° C, wt% 10.7 5.1 5.4 Safety load four- ball device, N .1962 2452 2452 Graduate degree 0 1 0-1 0-1 Kcnablescg lower limit- Ra, C 30 30 -30 Tendency to swell, 163 ° C on, after 6 hours, t% 9.9 3.03 3.5

t = mass .4

-4 195 (.75

Table 3

Features Conventional lithium fat Example 5 Example 6 5 Drop point, ° C 202 220 220 above above 10 Penetration at 25 ° C 0.1 mm before breaking 213 220 228 After 60 fractures * 227 223 233 10 * after fracture 239 229 238 Penetration has become. 15 0.1 mm 12 6 5 NLGI grade 3 3 3 Holds free alkali. NaOH,%. 0.18 0.20 0.21 Micropenetration, 25 ° 20 At C 0.1 mm 60 fracture after 231 214 218

watch Shell — Roll spiral

after the relay Micropenetration has become. 245 220 225 1 25 0.1 mm 14 6 7 Colloidal Stability,% by weight 9.81 N load, 30 min 14.9 8.2 9.3 Syncrisis at 100 ^c C, t% 0.9 0.0 0.3 140 ° C, wt% 7.5 1.6 • 1,9 30 Violence load four- ball device, N 1962 2452 2452 Grade EMK.0R 0-1 0-1 0-1 Lubricity lower limit- mp, ° C -30 -30 -30 35 Tendency to expand, 163 ° At C after 6 hours, t% 4.8 1.9 2.1

t = mass

Oil holding capacity was determined by two methods. One method concerns colloid stability according to GOSZT 7142-74. This method measures the amount of oil precipitated at 9.81 N for 30 minutes at room temperature. Its value is indicative of the tendency of the oil to precipitate during storage. The lower the value of colloidal stability, the better the oil holding ability of the lubricant during storage.

The other method relates to the synthesis according to MSZ 13 184. According to this method, standard MSZ 11710 / 4-77 for lithium grease, NLGI 1 grade grease at 80 ° C requires NLG 2 cs 3 grade grease at 100 ° C to determine the degree of oil separation. It measures the tendency for oil to separate due to temperature. The smaller the size of the syneresis, the better the oil-holding capacity of the lubricating grease due to temperature increase.

The numbers shown in Tables 1,2 and 3, which indicate the oil holding capacity of the exemplary lubricating greases, do not clearly prove that the oil found by our mother has a significantly better oil holding capacity than conventional lithium greases. Further, the table shows that the lubricating greases of the present invention can be used at higher temperatures than conventional lithium based lubricating greases, especially at 140 ° C and at 163 ° C.

Claims (2)

Claims 1. A method of producing mineral oil-based multi-purpose lithium complex grease with saponification, dewatering, gel construction, cooling, cold mixing, addition, homogenization, and slurry removal, characterized in that 152S-- '560 4 - .., .. part lubricating oil 60 Heating to ° C and adding 49, i 120.6 parts by weight of lithium hydroxide monohydrate containing 50% by weight of lithium hydroxide in aqueous solution, 0.8-8.8 parts by weight of at least 52% by weight of calcium oxide in aqueous suspension, 253.5-692.5 parts by weight of technical grade 12-hydroxystearic acid . or 202.8-554.0% by weight of technical grade plant-grade vegetable oil of hydroxy stearic acid and 50.7-4 38.5 parts by weight of linoleic acid, and 18.0 to 45.5 parts by weight of technical grade boric acid in aqueous solution, the mixture being 90 ° C The mixture was heated to reflux for 2 hours, the oil was dissolved in a mixture of lithium and calcium soaps, heated continuously, and then 1900 to 2291 parts by weight of lubricating oil were added while the temperature of the mixture was raised to 205 ° C, and the heat was removed and added. 768-874 parts by weight of lubricating oil are mixed and the mixture is stirred at about 18 ° C, then the mixing is stopped and the mixture is allowed to stand at 180 ° C for 20 minutes, the resulting grease is known to be cold-mixed in a known manner, up to 7% of the crude oil refinery. % admixed with known grease additive, homogenized and vented in uk. 2. The l. A method according to claim 1, wherein the linoleic acid plant oil is industrial grade sunflower oil or soybean oil. Without drawing