US3925414A

US3925414A - Reaction product of isobutylene, sulfur monohalide and alkali metal mercaptide

Info

Publication number: US3925414A
Application number: US453610A
Authority: US
Inventors: Phillip S Landis; Abraham O M Okorodudu
Original assignee: Mobil Oil AS
Current assignee: Mobil Oil AS
Priority date: 1974-03-22
Filing date: 1974-03-22
Publication date: 1975-12-09
Anticipated expiration: 1992-12-09

Abstract

A compound obtained by reacting isobutylene and a sulfur halide to produce an adduct; reacting the adduct thus produced with an alkali metal mercaptide in a nonreactive liquid medium to obtain a product comprising a compound having the structure:

AND SEPARATING THIS COMPOUND FROM SAID PRODUCT. This compound is particularly useful as an extreme pressure additive in lubricant compositions.

Description

United States Patent [1 1 Landis et al.

[73] Assignee: Mobil Oil Corporation, New York,

22 Filed: Mar. 22, 1974 21] Appl. No; 453,610

[52] US. Cl 260/327 R; 260/139; 252/45 [51] Int. Cl. t. C07D 341/00 [58] Field of Search 260/327 R, 608, 139

[56] References Cited UNITED STATES PATENTS 7/1947 Kimball et al. 1. 260/139 1 1/1972 Horodysky et al .4 260/139 Primary Examiner-Sherman D. Winters Attorney, Agent, or FirmCharles A. Huggett; Raymond W. Barclay; Benjamin 1. Kaufman [57] ABSTRACT A compound obtained by reacting isobutylene and a Dec. 9, 1975 sulfur halide to produce an adduct; reacting the adduct thus produced with an alkali metal mercaptide in a nonreactive liquid medium to obtain a product comprising a compound having the structure:

CH3 U";

and separating this compound from said product. This compound is particularly useful as an extreme pressure additive in lubricant compositions 12 Claims, N0 Drawings REACTION PRODUCT OF ISOBUTYLENE, .SULFUR MONOI'IALIDE AND ALKALI METAL MERCAP'IIDE BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to new compositions of matter and, more particularly, to new compositions of matter, especially useful as extreme pressure additives in lubricating compositions, such as lubricating oils and greases.

2. Description of the Prior Art It is known that extreme pressure properties can be incorporated in lubricant compositions, such as liquid hydrocarbons and greases, by incorporating therein sulfurized olefins as extreme pressure additives. In this respect, such additives have heretofore been found to be deficient in lacking a relatively high non-corrosive sulfur content which is found to be particularly desirable in imparting good extreme pressure and anti-wear properties. In additives of this type it is also highly desirable that they be odorless and colorless, from a commercial standpoint. These latter characteristics have also been found lacking in present commercial sulfurized extreme pressure additives.

SUMMARY OF THE INVENTION It has now been found that improved extreme pressure properties can be imparted to lubricant compositions by incorporating therein minor amounts of a relatively high sulfurcontent additive which, in addition, does not impart odor to the lubricant and is also colorless. As more fully hereinafter described, this novel extreme pressure additive is obtained by reacting isobutylene and a sulfur halide to produce the corresponding adduct; reacting the adduct thus produced with an alkali metal mercaptide in a non-reactive liquid medium to obtain a product comprising a compound having the structure:

and separating the compound thus produced from the aforesaid reaction mixture. The compound thus produced is found to have a melting point of approximately 254C.

In general, the aforementioned reactions are conducted at ambient temperature. In most operations the reactions are conducted at a temperature from about C. to about 150C. and preferably at a temperature from about C. to about 60C. Insofar as the production of the adduct is concerned, sufficient sulfur halide is employed to react with all of the isobutylene. In general, for most operations, isobutylene and the sulfur halide are reacted in a mole ratio of from about 0.511 to about 2.521 and preferably in a mole ratio of from about 1:1 to about 2:1 by weight. Insofar as the reaction between the adduct and the alkali metal mercaptide is concerned, sufficient alkali metal mercaptide is employed to react with all of the adduct. In general, for most operations, the adduct and the alkali metal mercaptide are reacted in a mole ratio of from about 1:1 to about 1:5 and preferably in a mole ratio of from about 1:1 to about 1:2.5 by weight. Any alkali metal mercaptide may be employed for reaction with the adduct, as hereinbefore described, and may include sodium mercaptide, potassium mercaptide, lithium mercaptide, or calcium mercaptide. Any sulfur monohalide may be used for reaction with isobutylene and may include sulfur monochloride, or a combination of a sulfur dihalide and elemental sulfur to produce the corresponding sulfur monohalide which may also be employed as an equivalent reagent. Any non-reactive liquid medium may be employed for carrying out the reaction between the adduct and the alkali metal mercaptide and may include lower alcohols such as methanol, ethanol, propanol, butanol. The resulting extreme pressure compound, suitable for use as an extreme pressure lubricant additive is found to have a sulfur content of about 50%, by weight, and is odorless and colorless. This compound represents about 45%, by weight, of the product resulting from the reaction of the aforementioned adduct and the alkali metal mercaptide. The remaining portion of the aforementioned product comprises about 55%, by weight, a mixture of unsaturated sulfides and polysulfides.

The following data and examples will serve to illustrate the marked degree in extreme pressure improvement imparted by the novel additives of the present invention to lubricant compositions. It will be understood, however, that it is not intended the invention be limited to the particular lubricant compositions disclosed nor the particular additive for imparting extreme pressure properties. Various modifications thereof can be employed and will be readily apparent to those skilled in the art.

EXAMPLE 1 Sulfur monochloride (l013g, 7.5 moles) was charged into a 3-L. 4-necked reaction flask equipped with a mechanical stirrer, condenser (drying tube attached) a thermometer, and a sub-surface gas sparger. While keeping the temperature between 4550C., isobutylene was passed over 60g of methanol into the reaction flask over an 8-hour period, during which 716g(l2.8 moles) of isobutylene was consumed. The reaction mixture was then purged at 40C. with a stream of nitrogen for 30 minutes and then filtered to yield l579g of a light amber liquid.

Sodium mercaptide, 1200g) and 1250 ml of ethanol were charged into a 5-L. reaction flask fitted with a stirrer, condenser (drying tube attached) thermometer and an addition funnel. After stirring to get a good dispersion of the solids, 620g of the above, isobutylenesulfur monochloride adduct was added rapidly and carefully at first to attain a temperature of 45C. and then dropwise from the addition funnel. The addition took about 2 hours. By carefully regulating the addition, the temperature was kept at close to 40C. and excessive foaming (H 8 evolution) was avoided.

Following the aforementioned addition, the reaction mixture was heated, while stirring at 45-50C. for an additional 3 hours. After cooling to room temperature, it was filtered, the solids washed with hexane, and the filtrate allowed to stay overnight under house vacuum.

The solids were washed with water and ether and a water insoluble white solid product was collected. The solid product which precipitated from the filtrate was collected and washed several times with water and ether and dried. The combined solids were further purified by stirring vigorously in water and a little ether, collected and dried to yield 250g of white solid product, having a sulfur content of 53%. This product was found to have the structure hereinbefore described.

An S.A.E. 90 solvent-refined Mid-Continent oil having a pour point of 25F. was next subjected to the standard Four-Ball Wear Test for determining improvement in anti-wear properties. This test is described in U.S. pat. No. 3,423,316. In general, in this test, three steel balls of 52-100 steel are held in a ball cup. A fourth ball positioned on a rotatable vertical axis is brought into contact with the three balls and is rotated against them. The force which the fourth ball is held against the three stationary balls may be varied according to a desired load. The test lubricant is added to the ball cup and acts as a lubricant for the rotation. At the end of the test, the steel balls are investigated for wearscar; the extent of scarring represents the effectiveness of the lubricant as an antiwear agent. In the data of the following Table l, are shown the results obtained in which the aforementioned base stock oil was subjected to the Four-Ball Wear Test.

TABLE 1 4Ball Wear Test-Scar Diameter (mm) V2" Balls. 52-100 Steel. 60 Kg. hr.

Speed Tern Ex. F 500 RPM 1000 RPM 1500 RPM 2000 RPM 2 Room 0.50 0.60 0.88 2.34 3 200 0.60 1.06 1.86 2.23

The above-described product of Example l was next incorporated into the base stock lubricating oil of Table l in a concentration of 0.5%, by weight, and then subjected to the aforementioned Four-Ball Wear Test. The results obtained are shown in the following Table 11.

TAB LE 11 4-Ball Wear Test-Scar Daimeter (mm) 1%" Balls. 52-l00 Steel. 60 Kg, ll: hr.

It will be apparent from the comparative data of Table l and 11 that the novel compounds of the present invention are markedly effective as anti-wear additives. While compositions and components therefore it will be understood, by those skilled in the art, that departure from the preferred embodiments can be effectively made and are within the scope of specification.

We claim:

1. A compound having the structure:

2. A process for preparing a compound having the structure recited in claim 1, consisting essentially of reacting isobutylene and a sulfur monohalide to produce an adduct; reacting the adduct thus produced with an alkali metal mercaptide in a non-reactive liquid medium to obtain a product comprising the compound described in claim 1; and separating said compound from said product.

3. A process as defined in claim 2 wherein said reactions are conducted at a temperature from about 0C. to about C.

4. A process as defined in claim 2 wherein said reactions are conducted at a temperature from about 20C to about 60C.

5. A process as defined in claim 2 wherein isobutylene and the sulfur monohalide are reacted in a mole ratio of from about 0.521 to about 2.521.

6. A process as defined in claim 2 wherein isobutylene and the sulfur monohalide are reacted in a mole ratio of from about 1:1 to about 2:1.

7. A process as defined in claim 2 wherein the adduct and the alkali metal mercaptide are reacted in a mole ratio of from about 1:1 to about 1:5.

8. A process as defined in claim 2 wherein the adduct and the alkali metal mercaptide are reacted in a mole ratio of from about 1:1 to about 1:25.

9. A process as defined in claim 2 wherein the sulfur monohalide is sulfur monochloride.

10. A process as defined in claim 2 wherein the alkali metal mercaptide is sodium mercaptide.

11. A process as defined in claim 2 wherein the liquid medium is a lower alcohol.

12. A process as defined in claim 2 wherein the liquid medium is ethyl alcohol.

Claims

1. A COMPOUND HAVING THE STRUCTURE:

3. A process as defined in claim 2 wherein said reactions are conducted at a temperature from about 0*C. to about 150*C.

4. A process as defined in claim 2 wherein said reactions are conducted at a temperature from about 20*C to about 60*C.

5. A process as defined in claim 2 wherein isobutylene and the sulfur monohalide are reacted in a mole ratio of from about 0.5:1 to about 2.5:1.

8. A process as defined in claim 2 wherein the adduct and the alkali metal mercaptide are reacted in a mole ratio of from about 1:1 to about 1:2.5.

12. A process as defined in claim 2 wherein the liquid medium is ethyl alcohol.