DE2411580C3 - Process for the production of synthetic lubricating oils - Google Patents

Description

35

According to US-PS 31 13 167 synthetic lubricating oils by a two-stage polymerization of practically pure olefins such as 1-pentene, 1-decene and 1-hexadecene in the presence of conventional catalyst systems made from titanium halide and aluminum alkyl compound. The end product is a solution from high molecular weight solid polymers to lower molecular weight liquid polymers because in the first In the second stage, solid polymers are obtained at normal temperature and in the second stage, liquid polymers are obtained at normal temperature will. A solvent must therefore also be used in order to remove the differences that result from the different approaches to be able to compensate. Subjecting these known lubricating oils to high levels Temperatures or shear stresses, disadvantageous changes in viscosity occur, as they always occur Solutions of a solid polymer in a liquid polymer or in mineral oil can be observed.

It has now been shown that synthetic lubricating oils, which are characterized by a surprising constancy of the viscosity values under heavy use, are obtained if polymers produced in a certain manner with very high kinematic viscosity and boiling points above 175 ° C. are thermally cracked and the resulting polymers Products with a boiling point above 400 ⁰ C are catalytically hydrogenated. These synthetic lubricating oils have a very high viscosity number (viscosity index), very low pour points, a low viscosity at - 18 ° C and are characterized by considerable resistance to depolymerization, high heat resistance, very little carbon residue and high flash points .

These lubricating oils are solvent-free and can be used are made from commercially available, easily available and therefore cheap oil-fin mixtures.

The method according to the invention consists of two successive stages or phases:

The first stage or phase is described in a separate application filed at the same time and relates to the preparation of polymers with a considerably high molecular weight and a wide viscosity range from 250 to 15000 oCSt at 99 ° C. These polymers are obtained in high yields by polymerizing α-olefin mixtures obtained from cracking waxes or individual α-olefins of the general formula R-CH = CH? In which R is an alkyl group having 2 to 16 carbon atoms, in the presence of a catalyst consisting of titanium tetrachloride and polyiminoalane (TiCU / PIA); the polymerization is carried out in an inert atmosphere or an atmosphere which is at least partially substituted with hydrogen and in any case at an excess hydrogen pressure not exceeding 1 kg / cm ² ; the polymerization product obtained is distilled up to a head temperature of 175 ° C.

The second phase of the process, subject of the present invention, in which the synthetic Lubricating oils are obtained, is that the polymers obtained in the first phase with very high Viscosity and with boiling point above 175 ° C at atmospheric pressure are catalytically cracked to the Reduce molecular weight of polymers and maintain oils, due to their viscosity in the range belong to the lubricants or lubricating oils.

The catalytic cracking of the polymers with a very high kinematic viscosity results in lubricating oils obtained with high quality properties, in which in particular the heat resistance is significantly improved is.

By appropriate selection or modification of the catalyst and the working conditions, namely the Temperature and throughput, oils can be obtained that have all the desired viscosities from 4 cSt to to 20 - 30 - 50 cSt at 99 ° C.

A catalyst is preferably used in the catalytic cracking of the high molecular weight polymers used, whose carrier material is a weak Lewis acid (of the clay type), so that the Formation of low-boiling products is limited as possible.

If a defined or specific catalyst is used in the treatment according to the invention, the variable factors or parameters are the temperature and the throughput rate. Useful temperatures are in the range of 250 to 300 ⁰ C. The throughput speed LHSV given in v / v / h, namely volume of liquid per volume of catalyst per hour is in the range of 0.1 to 5, preferably in the range of 0.5 to 2 .

In the catalytic cracking according to the invention, the highly viscous polymer obtained in the first stage or phase is passed at atmospheric pressure through an electrically heated reactor tube which contains the catalyst. The product obtained in this way is fractionated under reduced pressure up to a head temperature of 400 ^° C., based on atmospheric pressure. The residue, the boiling point of which is above 400 ^° C., represents the synthetic lubricating oil; his

Yield is calculated in wt .-%, based on the • fed polymer with a boiling point higher than 175 ^L C. ⁶¹ Ie according to the viscosity of the fed polymer IiPBt the yield of oil at 61 -57% if r , it has a viscosity of 99 ° C from about 18 cSt at ^. ot _r , be and at 72-67%. if oils with a Vr,. ,, sitäi of about 30 cSt are sought (at 99 "C).

The oil obtained in the invention with a boiling point "her 400 ⁰ C is then hydrogenated to the existing unsaturated components to be removed. The, o Hvdrierung according to a generally known method is performed. In the special case was in the presence of a catalyst comprising 0.3% palladium contained on alumina, at a temperature of 200C,

'm Ani'angs hydrogen pressure of joo kg / cm- wah- κ

rend hydrogenated for a total of 5 h.

The hydrogenated oil with a boiling point above 400 ^° C. is the high-quality synthetic lubricating oil sought after.

A hydrogenated oil which is characteristic of the invention and has a viscosity of approx , a pour point of -5O ' ^J C, thermal depolymerization resistance, high heat or heat resistance, very little carbon residue and a flash point of 245' C.

The following examples serve to explain the invention in more detail and do not constitute any Restriction.

In the examples, the kinematic viscosity was determined in accordance with ASTM D 445. For the Two values are given for the viscosity number; one was made according to ASTM D 2270 / A and the other according to ASTM D 2270 / B, the more correct method for viscosity indices over 100. The pour point was determined according to the D 97 method and the iodine number according to the IP 84 method.

example

A polymer having a boiling point above 175 ° C, obtained by polymerizing the Cs obtained in the cracking of waxes Cio "olefins, having a viscosity at 99 ⁰ C of 66OcSt was catalytically cracked in a series of experiments, in order to reduce its viscosity and lubricating oils to obtain. The treatment was carried out by passing the polymer through an electrically heated reaction tube made of steel at a controlled rate at atmospheric pressure

Table 1

Oil with KP> 400 ° C

Diameter 40 mm was guided, which contained a catalyst bed which contained 200 cm ^{3 of} activated alumina with a content of 99% Al ₂ O ₃ (3.2 mm platelets).

The products obtained in the various experiments were vacuum distilled up to one Head temperature of 400 ° C, based on atmospheric

pressure. The residue had a boiling point above 400 ° C the synthetic lubricating oil.

attempt

Throughput temperature yield cSt 99 ⁰ C v / v / h

cST 38 ⁰ C viscosity index pour point iodine number

(l / l / h)

Wt%

250 78 270 60 290 51

37.4 16.9 8.04 324
125
47.9

129-173
132-157
136-151

-49

42

The examples show that by means of catalytic cracking of a polymer with a viscosity of 66OcSt at 99 ° C lubricating oils can be obtained at relatively low temperatures.

From the corresponding diagram it was deduced that an oil with a viscosity of about 18 cSt at 99 ° C can be obtained in a yield of about 61% by weight when at a temperature of about 268 ° C and with a throughput rate of.

example

catalvtical treatment was carried out with and with the same amount of 200 cn ^ activated alumina containing 99% Al ₂ O ₃ 3.2 mm plates).

Polymers that were used in: / cracking of waxes were also used in the device such as the obtained SC ₁₀ olefins and ₅₅ Example 1. The results of the experiments are in which the viscosity at 99 ° C. was 1160 cSt. Worked in Table 2 below, the same catalyst as in Example 1 was used

Table 2

oil with bp> 400 ° C

Experiment throughput temperature yield v / v / h
(l / l / h) ⁰ C wt%

cSt 99 ⁰ C cSt 38 ° C viscosity index pour point iodine number

250 81 270 57 290 48

50.1

18.2

8.5 443
139
52.4

129-184
131-156
134-149

-50

40

The results show that when working with a polymer with a viscosity of 1160 cSt at 99 ° C, lubricating oils can be obtained by cracking at relatively low temperatures.

From the corresponding diagram that an oil having a viscosity of about 18cSt at 99 ^'J C in a yield of about 57 wt .-% is obtained when operating at a throughput speed of 1 and a temperature of about 270 "C is obtained.

example

The synthetic oil obtained in Example 2 with a boiling point above 400 ^° C. (see Table 2) was hydrogenated until the olefinic double bonds were completely saturated. The hydrogenation was carried out in an autoclave in the presence of a catalyst containing 0.3% palladium on alumina, at a temperature of 200 ^° C. under a hydrogen pressure of 100 kg / cm ² , total time 5 h.

The properties of the oil before and after hydrogenation are summarized in Table 3.

Table 3

Properties of the oil from Experiment 2, Example 2 before and after hydrogenation

method

Not hydrogenated

hydrogenated oil

oil

Specific weight I. ASTM D. 1481 0.840 0.839 Kinematic viscosity at 99 ° C / cSt Viscosity index \ ASTM D. 445 18.2 19.2 Kinematic viscosity at 38 ° C / cSt Absolute viscosity at -18 ° C, cP ASTM D. 445 139 152 Pour point, ⁰ C ASTM D. 2270 / A 131 130 Ramsbottom, C residue,% by weight ASTM D. 2270 / B 156 154 Flash point, ⁰ C ASTM D. 2602 5700 5900 Molecular weight ASTM D. 97 -52 -50 Iodine number g / 100 g ASTM D. 524 - 0.008 ASTM D. 92 - 245 osmom - 650 IP 84 40 2

The results show that the hydrogenation does not noticeably change the properties of the oil and stay very well.

The viscosity values at 99 ° C and at -18 ⁰ C and 40 Flash point, the values for the yield point show that the oil shows both the heat and the cold in a very good behavior. Also noteworthy are the very low levels of carbon residue and the high level

example

The hydrogenated oil according to Example 3 was 45 to 38 ⁰ C (ASTM D 2603-70). The results are summarized in the shear strength test with the Raytheon sound oscillator in Table 4 below, subject to test duration 15 min, test temperature Table 4
Hydrogenated oil from Example 3

Before the attempt After the
attempt

Kinematic viscosity at 19.2 19.1 99 ° C / cSt Kinematic viscosity at 152 151 38 ° C / cSt

The results show that the hydrogenated oil obtained according to the present invention is resistant to the Sonic depolymerization tesi.

Example 5

The hydrogenated oil according to Example 3 was tested for heat resistance in accordance with the Federal Standard method No. 2508 "Thermal Stability of Lubricating and Hydraulic Fluids"; Here 2OcRi- 'deaerated oil to be kept in a sealed glass tube for 24 h at 260 ⁰ C and observed. The results are summarized in Table 5 below.

Table 5

Hydrogenated oil from Example 3

Federal Standard Method No. 2508. The following results were obtained:

Before the After A) Shear Strength at Before the After attempt attempt Kinematic viscosity attempt attempt Kinematic viscosity at 19.2 19.1 99 ° C / cSt at 99 ° C / cSt ίο Kinematic viscosity
38 ° C / cSt 21.43 18.82 Kinematic viscosity at 152 149 B) heat resistance at 38 ° C / cSt Kinematic viscosity 140.2 122.8 99 ° C / cSt at The results show that > that according to the invention '5 Kinematic viscosity 21.43 17.78 produced oil is thermally stable. 38 ° C / cSt 140.2 115.1 L.

It was according to US-PS 31 13 167 a solution of 10 wt .-% hydrogenated solid polymer from a Cio α-olefin (l-decene) and from 90% by weight liquid hydrogenated synthetic oil made from the same olefin. The viscosity of the liquid polymer was 5.41 cSt at 99 ° C. The viscosity of the obtained Solution was 21.43 cSt at 99 ° C and 140.2 cSt at 38 ° C.

The synthetic lubricating oil thus obtained became those described in Examples 4 and 5 Subjected to tests, namely the heavy-duty test with the sound oscillator Ray ton and the Heat resistance test according to the method The comparison with the results of Examples 4 and Fig. 5 shows that in the synthetic oils obtained by the known methods, the viscosity in both Resistance tests is adversely changed. In the case of the synthetic oils produced according to the invention on the other hand, there is practically no change in viscosity with the same load.

The observed with the known synthetic oils Viscosity change always occurs when a solution of solid polymers in liquid polymers or in Mineral oil is subjected to high temperatures or heavy loads.

Claims (2)

Patent claims: 1. A process for the production of synthetic lubricating oils with a high viscosity number, very low pour point, low viscosity at -18 ° C, high heat resistance, high resistance to depolymerization, high flash point and very low carbon residue, characterized in that highly viscous poly, ₀ mers with a boiling point above 175 ⁰ C, which by polymerizing na-olefins of the general formula R-CH = CH ₂ , in which R stands for an alkyl group with 2 to 16 carbon atoms, in the presence of a titanium tetrachloride / polyiminoalane catalyst, 5 System in an inert atmosphere or an atmosphere at least partially substituted by hydrogen at a pressure of up to 1 kg / cm ² overpressure, catalytically cracking at atmospheric pressure and a temperature in the range from 250 to 300 ⁰ C and a throughput rate of 0, 1 to 5, preferably 0.5 to 2, adheres to, whereupon the product obtained is distilled in vacuo up to one Head temperature based on atmospheric pressure of 400 ⁰ C and finally the residue with boiling point above 400 ⁰ C catalytically hydrogenated. 2. The method according to claim 1, characterized in that one is in the presence of a catalyst crackt, the oxides or sulfides of metals in groups VI to VIII of the periodic table in Contains combination with a carrier that is a weak Lewis acid.