JPH0442439B2 - - Google Patents

Description

[Detailed description of the invention]

Sulfurized olefins are well-known additives in lubricating oils, cutting oils, and the like. A product of this type is described in US Pat. No. 2,249,312 to Kimball. U.S. Pat. No. 2,708,199 to Eby discloses a similar product, in which a sulfur halide is reacted with an olefin using a lower alkanol cocatalyst to obtain an intermediate product, which can be converted into an alkali or alkaline earth It states that it is caused to react with polysulfides of similar metals. U.S. Patent No. by Myers
No. 3,471,404 discloses a product in which sulfur monochloride is reacted with an olefin to obtain an intermediate product, in a critical ratio of 1.8 to 2.2 gram moles of metal sulfide to 1 gram mole of sulfur.
A comparison is made with reacting the intermediate products with sulfur and alkali metal sulfides. This material is then refluxed with an aqueous alkali metal hydroxide solution for 1 to 24 hours. According to the invention, sulfur monochloride is reacted with an aliphatic molar olefin to form an adduct, which is reacted with sulfur and sodium sulfide, and then without further treatment with an aqueous solution of caustic alkali. It has been discovered that improved sulfurized olefinic additives for lubricating oils can be obtained by recovery using conventional methods. That _is , _the present invention provides a method for producing a sulfurized _lubricating oil additive that improves extreme pressure properties. (b) in an aqueous alkanol medium at 50°C.
~ At reflux temperature, the adduct is 0.45 ~
reacting with sulfur and Na ₂ S using 0.7 gram moles of Na ₂ S and 0.15 to 0.2 gram atoms of sulfur per gram mole of Na ₂ S, and (c) adding the additives described above without heating with an aqueous caustic solution. Provided is a method characterized by various steps for recovering. Useful olefins are monoethylenically unsaturated aliphatic hydrocarbons containing 3 to about 6 carbon atoms, referred to as aliphatic monoolefins. These include 1-butene, 2-butene, isobutene, 1-pentene, 2-pentene, 2-methyl-1-butene, 3-methyl-1-butene, 2-
Methyl-2-butene, 1-hexene, 2-hexene, 3-hexene, 2-methyl-1-pentene,
Included are 2-methyl-2-pentene, 2-ethyl-2-butene, etc. and mixtures thereof. Olefins include isobutene, 2-methyl-1
Branched chain olefins such as -butene, 2-methyl-2-butene, 2-methyl-2-pentene and the like are preferred. More preferably, the ethylene double bond is adjacent to a tertiary carbon atom, as in isobutylene, the most preferred olefin. Preferably, the first step (ie, step (a)) is carried out by adding the olefin to sulfur monochloride. Olefins can be added as gases or liquids. Preferably, the olefin is added below the surface of the sulfur monochloride as a liquid. As a practical matter, the olefin is added until the reaction with sulfur monochloride ceases, which is indicated by a decrease in exotherm. Olefin in an amount of about 0.75 to 2.0 g mole for each 0.3 to 0.75 g mole of sulfur monochloride (about 1 to 2.0 g mole for each gram mole of sulfur monochloride).
6.6 gmol of olefin) is usually sufficient.
A preferred amount is about 18 to 2.2 gram moles of olefin per gram mole of sulfur monochloride. Although the reaction between sulfur monochloride and olefin will proceed without the addition of an alkanol cocatalyst, the use of an alkanol cocatalyst is highly preferred. In the method of the present invention, by using such a cocatalyst, a marked improvement was achieved.
A product with EP (extreme pressure) properties is obtained. The lower alkanol promoter used in the first stage is, for example, methanol, ethanol, n-propanol, isopropanol, isobutanol, t
-containing about 1 to about 4 carbon atoms, such as butanol. The most preferred cocatalyst is methanol. The lower alkanol cocatalyst can be added to the sulfur monochloride from the beginning, can be added to the reaction mixture periodically or continuously during the course of the olefin addition, can be mixed with the olefin, and can be added along with the olefin. can. The preferred type of addition is either to add the entire amount first and then add the olefin, or to add both the alkanol and olefin at the same time. The amount of alkanol cocatalyst is
Preferably from about 0.001 to about 0.3 gram mole to 0.3 to 0.75 gram mole. The first-order reaction can be carried out at any temperature high enough to allow the reaction to proceed, but not so high as to cause decomposition of the reactants or products. A range of about 30 to 100°C is a useful range. A more preferred range is about 40 to 75°C, and a most preferred range is about 50 to 60°C. The first stage reaction should be carried out for a sufficient time to complete the reaction between the sulfur monochloride and the olefin. This is usually limited by heat removal. Preferably, the olefin feed rate is controlled to maintain the temperature within the desired range. The temperature should drop as the sulfur monochloride is consumed. External heat can be applied to continue the reaction further, but this does not appear to be necessary. The total time required to complete the reaction depends on the scale of the process and can vary from a few minutes to 12 hours or more. Time is non-critical. Since HCl gas is generated during the first stage reaction, means should be provided to scrub the exhaust gas from the reactor to remove HCl before it is released to the atmosphere. In the second stage (ie step (b)) reaction, the adduct from the first stage is reacted with sodium sulfide and sulfur in an aqueous alkanol reaction medium. The second stage is preferably carried out by charging an aqueous sodium sulfide solution, water, alkanol and elemental sulfur into a reactor and then adding the adduct thereto at the reaction temperature. Sodium sulfide may be obtained from any of a number of source materials. For example, it can be prepared by mixing approximately equimolar amounts of sodium hydrogen sulfide and sodium hydroxide. If hydrogen sulfide is available, it is adsorbed in an aqueous NaOH solution to form a solution of sodium sulfide and/or sodium hydrogen sulfide, depending on the amount of hydrogen sulfide adsorbed. Regardless of the source material, the resulting solution consists primarily of sodium sulfide;
The solution should be adjusted with NaOH, NaSH or _H2S to contain no or very little free sodium hydroxide. The amount of sodium sulfide can vary somewhat. For example, about 0.45 to 0.7 gram mol (about 0.6 to 2.3 gram mol per gram mol of sulfur monochloride) relative to the adduct formed in the first step (step (a)). Preferably, the amount of sodium sulfide is about 0.7 to 2 gmol per mole of sulfur monochloride;
Most preferably 0.8 to 1 gram mole. The amount of water can be varied over a wide range without adverse effects. Good results can be obtained using about 10 to 20 gmol of water to 1 gmole of sodium sulfide. In this case, water is used as water itself, as water contained in the aqueous reactant solution, and also as water to be formed by reaction with sodium hydroxide hydrogen sulfide or sodium hydrogen sulfide in forming the sodium sulfide solution. This includes adding as. Alcohol is required for the second stage reaction.
These include, for example, methanol, ethanol, n-
1 to 4 carbon atoms such as propanol, n-butanol, isobutanol, t-butanol, etc.
lower alkanols and mixtures thereof. A preferred alkanol is isopropanol alone or in mixtures with other alkanols such as t-butanol. The amount of alkanol can likewise be varied within a wide range. Approximately 0.1 to 0.5 per part by weight of water
A range of parts by weight is a useful range. A more preferred range is about 0.2 to 0.4 parts by weight of alkanol to 1 part by weight of water. The preferred amount of sulfur added is 0.45 each of sodium sulfide.
0.05 to 0.18 gram atoms for 0.7 to 0.7 gram moles. More preferably, about 0.15 to 0.2 gram atoms of sulfur are used per gram mole of sodium sulfide. In a preferred type of operation, a mixture of sodium sulfide, sulfur and aqueous alkanol is stirred and heated to reaction temperature, and then the adduct is added thereto. However, it is also possible to carry out the reaction in other ways, for example by adding a mixture of sodium sulfide, sulfur and aqueous alkanol to the adduct, or by mixing everything together and heating the mixture. The preferred second stage reaction temperature is from about 50°C to reflux temperature. A more preferred reaction temperature is about 60 to 80°C. After the addition of the adduct to the sodium sulfide/sulfur/aqueous alkanol mixture is complete, the mixture is heated to reflux for about 2 to 8 hours to ensure completion of the reaction, which is usually complete in about 1 to 8 hours. is preferred. The products obtained according to the invention generally contain a maximum of about 0.7-0.75% by weight of chlorine, such as about 0.5% by weight, and a minimum of 47-48% by weight, such as about 49-50% by weight of sulfur. An essential feature of this new sulfurized product is that, when prepared according to the above description, no separate caustic treatment is required to obtain a useful EP additive. Therefore, the present invention does not contemplate a product that is subsequently heated with an aqueous caustic solution, such as is shown in US Pat. No. 3,471,404 to Myers. After reacting the adduct with sodium sulfide and sulfur, the product is recovered by conventional methods such as alkanol removal, water washing and filtration. The method for producing sulfurized olefins will be explained using the following example. Example 77.7 g of sulfur monochloride and 0.31 g of methanol are placed in a reaction vessel. While stirring, begin adding liquid isobutylene below its surface and bring the temperature to 55
Raise to ℃. Continue adding isobutylene at this temperature until the exothermic reaction stops. Requires 28-32 g of isobutylene. In a second reaction vessel, 90 g of a 32.1% by weight aqueous solution of sodium hydrogen sulfide and sodium hydroxide were added.
Mix with 41.3 g of 50% by weight aqueous solution. To this is added 44.4 g of isopropanol and 2.9 g of sulfur.
Stir for 5 minutes, then add 55.1g of water and stir the mixture.
Heat to 75°C. While stirring at approximately 75°C,
Add the first stage adduct to this mixture over a period of 2 hours. After this time, the mixture is heated to reflux for 4 hours to complete the reaction. The isopropanol is distilled off at a temperature below 90°C and then reduced pressure is applied to complete the removal of alcohol and most of the water. Wash the product with 68 g of water, remove the salt,
Separate and remove the aqueous layer. A second wash of the organic layer is carried out with a mixture of 68 g water and 34 g hexane.
The mixture is heated to reflux with stirring, then cooled and separated. Discard the aqueous layer and distill off the hexane from the organic layer. The remaining material is passed through to obtain sulfurized olefins (48% sulfur by weight), which are highly effective in lubricating oils.
It is an EP additive. The sulfurized olefins are particularly useful in lubricating oil formulations for use in gears. The base oil can be mineral or synthetic. Useful synthetic oils include olefin oligomers such as decene trimers, tetramers, and pentamers made by oligomerizing 1-decene using a _BF3 catalyst. Other catalysts, such as aluminum alkyl Ziegler catalysts, can be used to make useful olefin oligomers. Similarly, other olefins can be used, such as _C6-14 1-olefins. It is also possible to use synthetic alkylbenzenes such as di-dodecylbenzene and the like. Also, alkyl esters of dicarboxylic acids (e.g. di-2-ethyl-hexyl sebacate), fatty acid esters of polyols (e.g. trimethylolpropane, tripelargonate) or complexes of alkanols, alkanes, polyols and carboxylic or polycarboxylic acids. Synthetic ester based lubricants such as esters can also be used. In this application, a sufficient amount of sulfurized olefin is added to improve the EP properties of the lubricating oil.
Amounts of 0.1 to 10.0% by weight are usually sufficient. Fully formulated gear lubricants include other conventional additives that serve a variety of functions. Examples of other additives of this type are, for example, tetrapropenylsuccinic acid and bis-(2,5-alkyldithia)-1,3,4-
Corrosion inhibitors for ferrous and non-ferrous metals such as thiadiazole, and antiwear additives such as alkyl or aryl phosphonates, phosphites, thiophosphates, dithiophosphates and phosphoric acids. Also used are zinc dialkyl or diaryldithiophosphates, chlorinated hydrocarbons, sulfurized fatty esters and amines. A test was conducted to demonstrate the EP effect of sulfurized olefin. In these tests, the products of the invention, prepared essentially as described in this example, were compared to the compositions of Myers, US Pat. No. 3,471,404, prepared accordingly. The analysis results of both products were as follows.

[Table] Tests were conducted in SAE90 mineral oil. The first was a four-ball weld test (ASTM D2783), in which one steel ball was placed in loaded contact with three fixed balls.
contact) rotate downward. Record the maximum load that does not cause welding as the passing load. The second test performed was the SAE load test, in which two steel rings were rotated in loaded contact such that there was a metal slide at the point of contact. Measures the maximum load before metal seizure. The results of these tests were as follows.

Table: These test results demonstrate that the additives of the present invention are highly effective.

Claims (1)

[Claims] 1. A method for producing a sulfurized lubricating oil additive that improves extreme pressure properties, comprising: (a) 0.3 to 0.75 gmol at 30 to 100°C;
S ₂ Cl ₂ is reacted with 0.75 to 2 gram moles of C _3-6 aliphatic monoolefin to form the adduct, (b) produced in step (a) above in an aqueous alkanol medium at 50° C. to reflux temperature. Additives, 0.45~
With 0.7 gram moles of Na ₂ S and 0.15 to 0.2 gram atoms of sulfur for 1 gram mole of Na ₂ S,
The process is characterized by the steps of: reacting with sulfur and Na ₂ S; and (c) recovering the additive without heating with an aqueous caustic solution. 2. The method described in item 1 above, wherein the monoolefin has a branched chain. 3 Process in the presence of a promoter amount of lower alkanol
The method according to item 1 above, characterized in that (a) is carried out. 4. The method described in the above item 1, 2 or 3, wherein the monoolefin is isobutene.