DK142994B - Fully Synthetic Lubricant - Google Patents

Description

(11) PUBLICATION WRITING 142994 DENMARK, 5 ”ln, cl '0 10 H 3/20 • (21) Application No. 2580/70 (22) Filing on 20« mSj 1970 (24) Running day 20 May 1970 (44) The application presented and "the petition published on 9 · DIST · 1 9" 1

DIRECTORATE OF

PATENT AND TRADEMARKET SYSTEM (30) Priority requested from it

May 21, 1969, 1925817, DE

(7i) VEBA-CHEMISTRY AKTIENGESELLSCHAFT, Geleenkirchen-Buer, Dorstener Str.

"527, DE.

^ Inventor: Karl Schmitt, 469 Herne, Klopstockstr. 4, DE: Josef Distel = village, 468 Warmé ^ Eickel, Holsterhauser Str. 127, DE: Werner Flalcus, 469 Herne, Eickeler Str. 7, DE.

(74) Plenipotentiary in the proceedings:

International Patent Office. ____ (54) Fully synthetic lubricant,

The preparation and use of monomeric esteries as useful lubricants are described in the literature. The predicates on such oils are e.g. excellent viscosity-temperature ratio, low viscosity in the cold region, good oxidation and thermostability, poor coke and lacquer formation, excellent load capacity and good refrigerant properties. In some very important applications, such as however, in the manufacture of multi-range engine oils for diesel and ottomot engines or when used as gear exchange and rear axle oils, monomeric ester oils, due to their viscosity location, volatility or flash point, generally have a limited use as useful lubricants.

The invention relates to a lubricant prepared by transesterification with a diol of a dicarboxylic acid ester or a mixture of several such esters of one or more unbranched dicarboxylic acids having 3-12 C atoms with branched primary alcohols having 4-14 C atoms, and which lubricant in addition to the above mentioned properties also meets the viscosity, volatility and flash point requirements. The lubricant of the invention is characterized in that the diol component is a mixture of 2,2,4- and 2,4,4-trimethylhexane-1,6-diol. The molar ratio of dicarboxylic acid ester component to diol is preferably from 10: 1 to 1: 1, and most preferably from 2: 1 to 4: 3. The structure of the complex sterols obtained by this transesterification according to the invention is based on the following structure:

Monoalcoholic dicarboxylic acid trimethylhexanediol dicarboxylic acid monoalcohol m (branched) (straight chain) (branched) (straight chain) (branched) Γ LH3 fH3 Ί R1 ---- 00C- (GH_) -C00-CH-C-CH "-CH-CH" -CH _-------- 00C- (CHo) -C00-R1 Z n ZIZ ZZ Zn L ^>

Herein: branched chain alkyl groups of chain length C4 "C14 • n = 1-10 m = 1-25

Furthermore, by mixing monomeric esteries with complex esters, it is possible to mutually vary the physical properties of the two ester types. The surprisingly great utility of the complex sterols thus formed or their mixtures with monomeric esters allows an even universal use of these substances as lubricants of all kinds.

By varying the molar supply amounts of the components, it is possible in principle to produce complex esters with molecular weights of more than 5000. However, optimum properties are obtained from complex esters or their mixtures with monomeric esteryls at intermediate molecular weights of 500-1500. Surprisingly, it has now been found that esterols with molecular weights up to 1500, which corresponds to a viscosity according to the structure of the oils of up to approx. 50 cSt at 99 ° C, is fully miscible with e.g. mineral oils of all kinds. Complex esters with molecular weights greater than 1500, on the other hand, are only limited in mineral oil compatibility, even when diluted significantly with monomeric esters. Analogue complexes based on polyether glycols instead of trimethylhexanediol are only very limited mineral oil compatible.

Given the economic conditions given and for the purposes of the present specifications, the unlimited miscibility of ester oils with mineral oils is a desirable prerequisite for their use as lubricants. The complex ester oils of the invention fulfill this condition. The preparation of particularly useful low molecular weight complex esters is dependent in several respects on the structure U2994 3 of the individual reaction components as shown in the table below:

Table 1.

Properties of complex esters with intermediate molecular weights of from 700 to 800 depending on the structure of the individual reaction components. The "stock point" is the temperature at which an oily substance, upon cooling under the conditions defined in DIN No. 51.583, just stops flowing.

Monoalcohol Dicarboxylic acid piol Stock point ° C Viscosity index straight chain straight chain +30 to +50 missing branched straight chain 0 to +20 140 - 160 branched branched straight chain -40 to -30 115 - 130 branched branched branched -30 to -20 100 - straight chain branched - 5 to +10 140 - 160 straight chain branched branch -55 to -45 125 - 130 straight chain branched straight chain -60 to -50 140 - 150 branched straight chain branched -60 to -50 140 - 150

In the production of complex esters with comparable intermediate molecular weights, it has been found that the chain length of the individual components has a less pronounced influence on the most important lubricating properties of the ester. An exception, though, is the oil-dissolving similarity of such products. In principle, complexes of short-chain monoalcohols, dicarboxylic acids and diols tend to decrease the oil solubility. For this reason alone, it is advantageous to choose the chain length of the individual reactants, especially of alcohols and diols, in the region of Cj, preferably of C ^.

The particular advantages of using 2,2,4- / 2,4,4-trimethylhexane-1,6-diol, one sterically hindered diol, for the production of complex esters are in detail: 1. The diol slows down slowly, thereby preventing the formation of appreciable amounts of high molecular weight condensation products that are limited to oil compatible.

2. Oil-soluble complex esters can be distilled if necessary. The hydrolysis tendency is very poor.

3. At excessive thermal load, optionally cleaved trimethylhexanediol does not form sludge or varnish, but by virtue of intraraolecular water cleavage, an oil-soluble, easily volatile cyclic ether, namely trimethylcyclooxaheptane.

4 U2994 fH3 H3 \ / ~ TCH3 HO-CH2 - ^ - CH2- ^ H-CH2-GH2OH -> J \

™ 3 CH3 - »2 ° SJ CP20: 60 ° C

4. Unlike many other diols, trimethylhexanediol is poorly water soluble and therefore forms complex sterols which are very well oil compatible.

The remarkable quality width of the lubricants of trimethylhexanediol based on lubrication technology not only enables their use for lubrication of drives for aircraft engines, but above all their use as universal engine oil for both otto and diesel engines under Arctic and tropical conditions, but also their application as gear oil and ATF (automatic transmission fluid).

In particular, the complex sterols produced by the viscosity range of from 4.2 to 9.6 cSt at 99 ° C meet, e.g. SAE 5 W 20 oil, the lubrication requirements of the previously mentioned lubricants. The addition of additives to the complex sterols is done in order to ensure compatibility with mineral trade products essentially by means of classical inhibitors and additives and according to the requirements of the lubricant at all times.

In general, complex sterols need a significantly less additive content than mineral oil products. Certain additives such as VI enhancers, stock-point reducing agents and foam inhibitors are hereby abolished completely. Ester oils' low tendency to coke, varnish and resin formation, as well as their excellent ability to dissolve dirt or disperse combustion products and stripped material, allow for a significant reduction in residual additives compared to commercially available HD oils. With 0.1-5% total additive according to the purpose of the use of ester, highly usable lubricants that exhibit low rubbing and corrosion wear, enable low operating temperatures and also ensure clean machine parts. Thus, e.g. a 5 ff 20 oil with 5% additive (additive gasket) oil is advantageously used as a summer and winter oil for otto and diesel engines, thereby providing the compatibility of this oil with the commercially available HD single and HD multi-range oils. A single such oil thus replaces the 4 normally needed special oils: Summer oil and winter oil for otto engines, summer oil and winter oil for diesel engines.

In order to achieve a practically desirable compatibility of complex ester products with both mineral base oils and also additives adapted thereto, the commercially available various additive packages were examined for their compatibility and suitability for complex esters. Although additives specifically designed for cotaplex esters are more effective and even lower in terms of additive content, they do not ensure universal activity in all the practically possible mixtures with the numerous commercial products available on the market. For this reason, the additive package (4-5% in total) to be used for complex esters consists of additives that are analogous to the additives needed for mineral oil additives.

Specifically, it consists of: 1. of oxidation and corrosion inhibitors, 2. of high-pressure additives and metal activators, 3. of detergents and dispersants.

The diminished additive addition is held by all inhibitors whose total proportion is at most 5%. Furthermore, it is permissible to further reduce the detergent and dispersant proportion in favor of additions 1) and 2).

Addition of Vt'-enhancers, stock-point depressants and foam inhibitors completely abolishes.

General process for preparing the complex esters of the invention, m + 1 mole of dicarboxylic acid dialkyl ester and m mole of trimethylhexanediol, and 0.05 - 0.1% (based on the total amount of added substances) transesterification catalyst, e.g. tetraalkyl titanate, heated with stirring to 150-180 ° G. The reaction is completed after removing 2m moles of monoalcohol, first under normal pressure, then under vacuum down to 0.1 Torr. Depending on molecular weight and boiling point location, the complex ester formed is purified by edge, pathway s distillation in vacuo or by activated charcoal bleaching after 1 hour at 200 ° C and subsequent filtration. Yield 92-95% of theory.

Complex ester I:

Prepared by reaction of: 2 moles of adipic acid di- (2-ethylhexyl) ester and 1 mole of trimethylhexanediol- (1,6) according to the general specification.

Physical data.

of the addition of the formed monomeric ester complex ester -18 ° C, cSt 108 2242 38 ° C, cSt 8.17 54.25 99 ° C, cSt 2.35 9.42 VI 116 142 VI £ - 170

Stock point ° C -58 -57

Flash point ° C 182 244

Evaporation losses according to Noack,% (DIN No. 51.581) 36.15 11.0 14299Λ 6

Kp20 ° c 208 Kp001 230-250

Complexester II:

Prepared by reaction of α: 2 moles of adipic acid di- (iso-decyl) ester and 1 mole of trimethylhexanediol- (1,6) according to the general specification.

Physical data: of the addition of the formed monomeric ester complex ester

-18 ° C, cSt 306 3000 cP

38 ° C, cSt 15.05 79.76 99 ° C, cSt 3.68 12.33 VI 152 137 VI_ 148 162

E

Stock Point ° C -73 -55

Flash point ° C 221 258

Noack loss according to Noack,% 7.5 4.7

Kp0 2 ° C 196 Kp0 01 250 - 270

Complexester III:

Prepared by reaction of: 2 moles of azelaic acid di- (2-ethylhexyl) ester and 1 mole of trimethylhexanediol- (1,6) according to the general specification.

Physical data: of the added monomeric ester complex ester complex -18 ° C, cSt 184 2838 38 ° C, cSt 11.0 75.73 99 ° C, cSt 2.96 12.80 VI 140 143 VI_ 138 181

E

Stock Point ° C -73 -61

Flash point ° G 217 268

Noack evaporation loss,% 13.0 4.8

Kp0j4 ° c 180 Kp001 240 - 270

Complexester IV:

Prepared by reaction of: 2 moles of azelaic acid di- (iso-decyl) ester and 1 mole of trimethylhexanedione- (1,6) according to the general specification.

7 14299Λ

Physical data; of the added monomeric ester complex ester compound -18 ° C, (CCS) cP 421 3500 38 ° C, cSt 20.50 88.70 99 ° C, cSt 4.68 14.16 - VI 163 140 VIE 165 176

Stock point ° C 254 282

Noack evaporation loss,%. 5} 32 ΚΡθ, 4 ° C 217 KpQj01 260-290

Complex ester V;

Prepared by reaction of: 2 moles of sebacic acid di (2-ethylhexyl) ester and 1 mole of trimethylhexanediol- (1,6) according to the general specification.

Physical data: of the addition of the formed monomeric ester complex ester -18 ° C, cSt 183 2880 38 ° C, cSt 12.46 79.70 99 ° C, cSt 3.29 13.52 VI 154 144

Vig 152 185

Stock Point ° C -62 -61

Flash point ° C 221 274

Noack evaporation loss,% 10.7 4.0

Kp0_2 ° C 185 Kp0; 01 250 - 280

Complexester VI:

Prepared by reaction of: 2 moles of decandicarboxylic acid di- (2-ethylhexyl) ester and 1 mole of trimethylhexanediol- (1,6) according to the general specification.

Physical data: of the addition of the monomeric ester complex ester complex -18 ° C, cSt 262 3582 38 ° C, cSt 15.22 98.21 99 ° C, cSt 3.86 16.16 VI 168 142 VI_ 170 187

L

8 142994

Stock Point ° G -66 -36

Flash point ° C 249 280

Noack evaporation loss,% 8.8 2.5

KpQjl ° C 198 Kp0j01 260 - 280

Complex ester VIII;

Prepared by reaction of: 2 moles of decandicarboxylic acid di- (iso-decyl) ester and 1 mole of trimethylhexanediol- (1,6) according to the general specifications.

Physical data: of the addition of the monomeric ester complex ester formed -? Ί8 C, (CCS) cP 540 4350 38 ° C, cSt 25.69 118.92 99 ° C, cSt 5.58 18.37 VI 159 140 VI ^ 178 183

Stock Point ° C -46 -30

Flash point ° C 266 290

Noack evaporation loss,% 3.5 1.9

Kp0j4 ° C 242 Kp0j01 300 - 340

Complexester IX:

Prepared by reaction of: 3 moles of adipic acid di- (2-ethylhexyl) ester and 2 moles of trimethylhexanediol- (1,6) according to the general specification.

Physical data: of the added monomer ester complex ester complex -18 ° C, cSt 108 25000 38 ° C, cst 8.17 402 99 ° C, cSt 2.35 42.25 VI 116 127 VI. - £ 164

Stock point ° C + -58 -34

Flash point ° C 182 297

Noack evaporation loss,% 36.2 4.9

Kp2> 0 208