DE1010521B - Process for the preparation of an oil solution of a practically odorless sulfurized terpene - Google Patents

Description

The invention relates to the preparation of an oil solution of a virtually odorless sulfurized monocyclic Terpenes.

It is known that the properties of mineral lubricating oils are improved by the addition of sulphurized terpenes can be. Sulfuration of terpenes can be done by heating the terpenes with elemental sulfur. All classes of terpenes have been proposed for this purpose, but only are of practical importance the monocyclic terpenes, the main representative of which is dipentene (dl-limonene). Usually one uses Commercial dipentene of indeterminate composition and vegetable origin. The mechanism apart from the fact that some p-cymene is formed, this reaction is still unexplained. Below is gives the analytical composition of two dipentenes commercially available in the United States.

component

Low-boiling parts
(not identified) ..

a-pinene

/ 5-pinene

p-menthane

a-terpineol

p-cymene

Dipents

Terpinoles

Fenchon

J2,4 (8) .p.] Y [enthadien ...

High-boiling fractions
(not identified) ..

Sample A,
Weight percent

2.6 - 2.4 - 13.7 - 5.2 7th 17.4 10 50.5 31 5.2 39 1.0 - 2.0 5

Sample B,
Weight percent

From this information it can be seen that the commercial product is dipentene mixtures of very different compositions. In general, these mixtures contain 65 to 30% dipentene, 25 to 6% terpinolene, while the remainder consists mainly of p-cymene and p-menthane. Simonsen also quotes in the book "The Terpenes", Vol. I, 1947, on p. 151 a remark by Escourron that dipentene is always a mixture of isomeric monocyclic terpenes and a sample he examined is 80% dl-limonene, 12% terpinolene and contained 8 ⁰ I ₀ a-terpinene.

Sulfuration is usually carried out by adding sulfur to the monocyclic terpene Quantities of 1.5 to 2 atoms of sulfur per terpene molecule heated to 135 to 200 °. The reaction is easy Process for the preparation of an oil solution

a practically odorless one

sulfurized terpene

Applicant:

Esso Research and Engineering Company _r Elizabeth, NJ (V. St. A.)

Representative: E. Maemecke, Berlin-Lichterfelde West,

and Dr. W. Kühl, Hamburg 36, Esplanade 36 a,

Patent attorneys

Claimed priority:
Great Britain May 15, 1953

take place and is exothermic. The product is an oily material that is usually reddish brown in color. Large amounts of hydrogen sulfide are evolved in the course of the reaction, especially when used a catalyst. It is advisable to use a catalyst at this stage. Suitable as such the accelerators known for the vulcanization of rubber, e.g. B. tetramethylthiuram disulfide, mercaptobenzothiazole and diphenylguanidine.

Even after removing the hydrogen sulfide, e.g. B. by blowing an inert gas, contains the Product still loosely bound and corrosive sulfur, as can be seen by dipping one A strip of bare copper, which is quickly blackened as a result of the formation of copper sulfide. from the different methods that can be used to remove this

709 549/427

loosely bound sulfur have been suggested, the most popular is leaching with strong caustic alkali. After sulfurization, the product still contains sulfur-free components. These are partly more or more less saturated constituents of the terpene charge, and some p-cymene is also contained, which apparently formed during sulfurization.

Those contained in the sulfurized monocyclic terpenes Unsulfurized compounds contribute to those properties of the product, which it as Making additive for lubricating oils valuable, not essential at. In fact, the unsulfurized ingredients increase sometimes even the deposits on the pistons of engines that are lubricated with oils containing this additive become, quite considerably. . - ■ The predominantly low-boiling non-sulphurized Fractions can be removed from the sulfurized product by distillation with steam, as described in British Patent 688,293. The product thus obtained is used as a lubricating oil additive better suited than the raw unsulfurized starting material.

Although by steam distillation up to 30 percent by weight of the crude sulfurized product can remove, result in the unsulfurized or only weakly sulfurized mono- 'remaining in the product cyclic terpenes have a remarkable and undesirable odor, which is also inherent in lubricating oils, which contain these additives. Up until now it has been thought impossible to do a greater proportion of the light ones To remove constituents of the sulfurized product by steam distillation, because the viscosity of the Sulphurized product increases rapidly if you use the steam distillation above that achieved so far Point beyond; in addition, the product is becoming increasingly oil-soluble.

According to the invention it is now possible to use considerably more low-boiling fractions of the sulfurized product to remove without the hitherto inevitable difficulties of an increase in viscosity or a decrease in Having to accept oil solubility when using the steam distillation in an oil solution of the sulfurized Terpenes performs. In this way a practically odorless product is obtained. It is necessary that more than 40 percent by weight of the distillate is removed to produce a relatively odorless product to get. The dissolving in oil can either before or immediately after the sulphuration of the concerned monocyclic terpenes. If the dissolving is done before sulfurization, one has the advantage of to be able to direct the sulfurization easily. On the other hand, when dissolving immediately after sulfurization has ended the terpenes takes place, the temperature of the sulfurized material can immediately be raised to that for the steam distillation necessary value can be lowered by adding cold oil to the reaction mixture.

The product obtained after steam distillation is a practically odorless oil solution Sulfurized monocyclic terpene which is lightly mixed with lubricating oil bases in amounts from 0.1 to 2, preferably 0.3 to 1 percent by weight of the amount of sulfurized terpenes can be mixed.

The steam distillation is carried out at a temperature below 150 °. Generally it recommends at a bulb temperature below 130 °, z. B. at 100 or 115 to 130 ° to destiUieren.

As an example of the value of the invention, Table I shows the effect of removing larger amounts of distillate according to the invention for the smell of sulfurized dipentenes.

Table I.

ent Tertien cies Smell of mineral oil distant pure Z / USo / tzes with 1 percent by weight sample Distillate, Additives *) Weight very similar to that percent by n. s. D. **) clear A. 33.5 very similar to that perceive by n. s. D. hardly different than B. 37.0 slightly less n. s. D. as n. s. D. hardly different than C. 39.5 very less n. s. D. odor faint odor D. 41.5 very less odor just E. 42.5 very less perceptible odor just F. 43.5 perceptible

*) The mineral oil mixture - is made with the same mineral oil compared which contains 0.5 weight percent normal sulfurized pipent.

**) n. s. D. = normal sulfurized dipentene, which after known method is steam distilled.

From Table I it can be seen that more than 40% of the distillate must be removed in order to be practically odorless Winning product.

Sulfurized monocyclic terpenes which are treated according to the invention not only have the advantage to be practically odorless but they also have a lower viscosity and a higher flash point than it could be achieved by the previously customary methods of steam distillation. If you z. B. from a sulfurized dipentene by steam distillation 43 percent by weight low-boiling components removed and this product is mixed with the same volume of a mineral lubricating oil, the flash point is this mixture 160 °, while the normal sulfurized product, from which only 30% by weight low-boiling components are removed by steam distillation, such as 66 to 93 ° owns.

The invention thus consists in a method for the preparation of oil solutions of a practically odorless one sulfurized terpene, which is made by sulfurizing a monocyclic terpene with elemental sulfur was, which is characterized in that from a concentrated oil solution of the sulfurized monocyclic Terpene in a mineral oil below the decomposition temperature of the sulphurized terpene in known Way, more than 40 percent by weight of low-boiling components removed by steam distillation.

example

A portion of raw sulfurized dipentene of the type described above is made in the same amount by weight Mineral oil mixed carefully. This mixture is the steam distillation at 110 ° subjected until practically no more volatile constituents pass over. The amount of distillate amounts to 43 percent by weight of the original amount of the mixture.

The residue contains 13.5 percent by weight sulfur. Taking into account the initial dilution with the the same amount by weight of mineral oil, it results for the purified sulfurized dipentene in the residue · εΐη Sulfur content of 27 percent by weight. In comparison to this, a previously customary

posed sulfurized dipentene, are removed from the low-boiling components, only 29%, 28.4 ° / ₀ sulfur and not purified by means of steam sulfurized dipentene 21.5 ⁰ ₀ Z p

Engine tests are carried out on lubricating oil mixtures based on mineral oil and the following Additives contain: A product produced according to the present invention (sample G), a product according to the known Process manufactured product (sample H) and the product not purified by means of steam (sample J). All of these mixtures also contain 1.5 percent by weight of an organic metal-containing detergent. The test is also performed with the base oil alone and the base oil + 1.5 percent by weight detergent carried out. The results are given in Table II below.

Table II 36 Hour Test (Chevrolet L-4 Engine)

Oil mixture, consisting of
Mineral oil base + sample S content of
sulphurized
Dipents,
7o Quality assessment
regarding
of education
of oil coal
in the engine
the CRC standard Weight loss
a Pb-Cu bearing,
G Viscosity
increase in
37.8 °,
7th 0.62% sample G.
0.3% sample H
0.4% sample J.
Mineral oil alone
Mineral oil + 1.5% detergent 27
28.4
21.5 9.4
9.4
9.3
9.5
9.4 0.08
0.11
0.29
1.44
0.70 20th
26th
35
47
30th

From Table II it can be seen that the product made according to the invention proves to be very beneficial in the engine proves compared to the mixtures prepared in the known manner. The viscosity increase after The 36-hour test was considerably lower than with the previously known products of this type, and the The odor of this mixture, corresponding to sample F in table I, is quite satisfactory.

35

Claims (4)

Patent claims: 1. A process for the preparation of an oil solution of a practically odorless sulfurized terpene which by reacting a monocyclic terpene with elemental sulfur, thereby characterized in that one consists of a concentrated solution of the sulfurized terpene in a mineral oil in a manner known per se by steam distillation below the decomposition temperature of the sulfurized terpene distilled off more than 40 percent by weight of low-boiling components. 2. The method according to claim 1, characterized in that the oil solution of the sulfurized monocyclic Terpene by adding an oil to the sulfurization mixture before or after sulfurization was produced. 3. The method according to claim 1 and 2, characterized in that the monocyclic terpene Dipentene, preferably technical dipentene, was used. 4. The method according to claim 1 to 3, characterized in that the steam distillation below 150 °, preferably between 100 and 130 °. Considered publications:
German patent application S 19 738 IVb / 23c;
U.S. Patent No. 2,594,279;
British Patent No. 688 293. © 709 549/427 6.57