Additive for lubricants and hydrocarbon fuels comprising reaction products of olefins, sulfur, hydrogen sulfide and nitrogen containing polymeric compounds

Abstract

 Disclosed is an additive composition for lubricants and hydrocarbon fuel compositions formed by reacting an olefin, elemental sulfur, hydrogen sulfide, and a polymeric nitrogen-containing compound in the presence of a catalytic amount of an amine. The reaction product is effective when mixed in desired proportions with lubricants and with hydrocarbon fuels.

Description

[0001] This application is directed to extreme pressure and antiwear additive for lubricants and fuels.

[0002] U.S. Patent 3,390,086 discloses the reaction of polyalkylene succinimides with elemental sulfur to provide lube oil dispersants.

[0003] U.S. Patent 3,401,118 discloses the preparation of alkenyl succinimides by reacting high molecular weight polyisobutenyl succinic anhydride with tetraethylene pentamine and subsequently reacting this product with low molecular weight polyisobutenyl succinic anhydride.

[0004] U.S. Patent 3,676,346 discloses a mixture of sulfurized pour point depressants and condensation products of polyalkylene polyamines with alkenyl succinic anhydride.

[0005] U.S. Patent 3,703,504 discloses a process which comprises sulfohalogenating an olefin with a sulfur halide in the presence of a catalytic quantity of a lower aliphatic alcohol to form a sulfohalogenated organic intermediate, and thereafter sulfurizing and dehalogenating the intermediate in the presence of a substantial quantity of a lower aliphatic alcohol by treatment with an aqueous alkali metal monosulfide solution derived from a spent aqueous alkali metal hydroxide effluent from hydrocarbon purification and having a substantial combined sulfur content in producing an organic sulfide of high combined sulfur content.

[0006] This invention provides a process for making extreme pressure (EP) and antiwear additives for lubricants and fuels. The process comprises reacting an olefin, elemental sulfur, hydrogen sulfide, and a polymeric nitrogen-containing compound. Optionally a small amount or catalytic amount of an amine is added to the reaction mixture. In another aspect this invention comprises the additive compositions produced by this process. In still another aspect this invention comprises the process for making lubricant and fuel compositions by adding to said lubricant or fuel an effective amount of the additive material. In still another aspect this invention comprises the lubricant and fuel compositions so made.

[0007] According to this invention, the additive material of improved performance and improved odor is formed by reacting an olefin, elemental sulfur, hydrogen sulfide, and a polymeric nitrogen-containing compound. Optionally, a catalytically effective amount of an amine is included in the reaction.

[0008] The olefin reactant preferably is a monoolefin and preferably is isobutylene but can also comprise other butenes, propylenes, pentenes and mixtures of the foregoing.

[0009] The sulfur reactant is supplied to the reaction mixture preferably in a powdered or a ground elemental form and should have a commercial grade of purity.

[0010] The hydrogen sulfide is added to the reaction mixture in the form of a gas preferably but may be admitted to the reaction mixture, if the reactor pressure is sufficient, in a liquid form.

[0011] The nitrogen-containing polymeric material preferably is selected from succinimides, amides, imides, esters containing nitrogen atoms, polyoxazoline and imidazoline compounds. Other preferred nitrogen-containing polymeric materials include the reaction products of polyisobutenyl succinic anhydrides, and carboxylic acids, or dicarboxylic acids or their corresponding anhydrides with:

(a) polyethylene amines such as diethylenetriamine, triethylenetetramine, or tetraethylenepentamine;

(b) polyols such as pentaerythritol, trimethylol propane in conjunction with (a) preceding or (c) following; and

(c) hydroxyl-containing amines such as tris(hydroxymethyl)aminomethane.

[0012] The molecular weight of the polymeric material should be at least 500-50,000, and preferably 1,000 to 5,000.

[0013] The polyoxazoline polymers are well known materials. Poly (2-substituted-2-oxazoline) polymers are available from Dow Chemical Company, Midland, Michigan. Poly(2-ethyl-2-oxazoline) designated PEOX 425 (Dow) is used in the examples which follow and has been found particularly useful.

[0014] The alkyl imidazoline compounds, also well known, can be prepared by reacting one mole of hydroxyethyl-ethylene diamine with an appropriate organic acid, such as naphthenic or decanoic acid. Such a preparation is described in U.S. Patent 4,440,658.

[0015] A typical succinimide useful in this invention is the reaction product of a polyisobutenyl succinic anhydride (made by the co-reaction of polyisobutylene of 900 molecular weight with maleic anhydride) with tetraethylene pentamine. In addition to the materials described above other polymeric materials can also be used such as polymeric esters, amides, imides and/or combinations thereof with succinimides.

[0016] The nitrogen-containing polymeric material can also be selected from polymeric esters, polymer ester/amides and/or borated derivatives as the fourth co-reactant to form improved and novel products. Included are: "carboxylic dispersants" such as those described in U.S. 3,163,603, 3,184,374, 3,215,707, 3,316,177, 3,340,281, 3,341,547, 3,632,510, 3,632,511, 3,697,428, 3,725,441, or amine dispersants such as those described in U.S. 3,413,347, 3,697,574, 3,725,277, 3,725,480, 3,726,882 or any of above post-treated with boron compounds, epoxides, urea, etc., such as those in U.S. 3,702,757, 3,703,536, 3,704,308, and 3,708,522. Omission of the above polymeric amines forms a product with higher objectionable odor level.

[0017] The reaction, preferably, is carried out by the direct reaction of the olefin, sulfur, hydrogen sulfide and nitrogen-containing polymer at temperatures from 130°C to 200°C for periods of between 2 and 24 hours at pressures from atmospheric up to about 6205 kPa.g (900 psig). The preferred ratios between the reactants is between 3 and 0.5 moles of olefin, .001 and 0.4 moles of nitrogen-containing polymer, and 0.5 to 0.7 (preferably 0.6) moles of hydrogen sulfide, each to 1 mole of sulfur. The optional amount of catalytic amines present should be that amount required to catalyze the reaction. The amine can be chosen from the aliphatic amines such as propyl amine or butyl amine. After reaction is complete the product is vacuum topped, or nitrogen sparged and is then filtered to yield the desired reaction product composition. The reaction product thus obtained is believed to be a mixture of compounds, the mixture working to provide improved thermal and oxidative stability and improved lubricity properties when added in effective amounts to a lubricant composition or hydrocarbon fuel. Ordinarily effective amounts will be in the range of 5.7 to 1430 kg per 1000m³ (2 to 500 pounds per 1000 barrels) of hydrocarbon material. It will also be understood that the resulting fuel and lubricant compositions will contain other additive materials for other purposes in the compositions. Other additives can include detergents, antioxidants, pour depressants, auxiliary EP/antiwear additives, color stabilizers, antifoam agents and the like.

[0018] It will be noted that in the process of reacting the above listed materials there should be a certain amount of free polymer amine in the nitrogen-containing polymer material used as a co-reactant. This amine is required to function as a reactant. Ordinarily there will be some free amine present in the products commercially available. A concentration of between 0.5 and 10 percent of the total weight of reactants of amine will be desirable. Suitable amines include, but not exclusively, reaction products of polyisobutenylsuccinic anhydride with polyethylene amines such as diethylenetriamine, triethylenetetramine, tetraethylenepentamine and hydroxyl containing amines such as tris(hydroxymethyl)aminomethane.

EXAMPLE 1

[0019] Approximately 408 grams of sulfur, 4 grams of polyisobutenyl succinimide containing free amine, 601 grams of isobutylene, and 142 grams of hydrogen sulfide were charged to a stainless steel reactor purged with nitrogen and equipped with a heater, cooler and agitator. The reactants were heated at approximately 160 to 165°C until the pressure, which reached a maximum of about 4830 kPa.g (about 700 psig) during the early stages of the reaction, dropped to well below 276 kPa.g (40 psig) indicating completion of the reaction. The reaction time was approximately 10 hours. The crude product was then sparged at about 100°C with nitrogen for about 10 hours to remove small amounts of volatiles. The crude product was an amber colored, low viscosity fluid with low odor, which was then filtered through a bed of diatomaceous earth. The product when analyzed contained approximately 45.5 percent sulfur.

EXAMPLE 2

[0020] Approximately 408 grams of sulfur, 58 grams of polyisobutenyl succinimide containing free amine, 601 grams of isobutylene, and 142 grams of hydrogen sulfide were charged to a stainless steel reactor equipped as generally described in Example 1. The reactants were heated at approximately 160 to 165°C and a pressure maximum was noted similar to that described in Example 1. During the latter stages of the approximate 12-hour reaction period, the pressure dropped to well below 276 kPa.g (40 psig) and leveled off, indicating completion of the reaction. The crude product was then sparged at about 100°C with nitrogen for approximately two hours to remove small amounts of volatiles. The crude product was an amber colored, low viscosity fluid with low odor which was filtered through a bed of diatomaceous earth. The product when analyzed contained approximately 46.9 percent sulfur.

[0021] The products of Examples 1 and 2 were blended into fully formulated automotive gear oil packages and evaluated for copper strip corrosivity. Results of the tests are shown in Table 1.

[0022] The products of Examples 1 and 2 were blended into fully formulated automotive gear oil formulations containing inhibitors, antirust and anticorrosion/antistaining additives and evaluated for EP/antiwear properties using the CRC-L-42 gear test. As can be seen from Table 2, formulations containing 3.0 percent of the products of Examples 1 and 2 passed the scoring test. Equivalent 3.0 percent concentrations and even higher concentrations of 3.2 and 3.4 percent of the product of U.S. Patent 3,703,504 (sulfurized isobutylenes) failed the identical scoring test with as much as 30-35 percent scoring compared to Examples 1 and 2 which show only 3 to 5 percent scoring.

[0023] The products of the examples were evaluated for odor and were found to be significantly improved when compared to the product of Example 1 of U.S. Patent 4,344,854, made in a manner analogous to the examples of this application but without the use of the above-described polymeric amine as a co-reactant.

Claims

1. A process for making an additive for lubricants and liquid hydrocarbon fuels comprising co-reacting:

a) an olefin;

b) sulfur;

c) hydrogen sulfide; and

d) a polymeric nitrogen-containing compound; and

e) optionally, a catalytic amount of an amine.

2. The process of claim 1 wherein the reactants are reacted at a temperature of about 130°C to about 200°C and a pressure of from atmospheric to 6200 kPa (gauge).

3. The process of claim 1 or 2 wherein the reactants are reacted in a molar ratio of olefin, nitrogen-containing polymer, and hydrogen sulfide to sulfur of 2 to 0.5, 0.001 to 0.4, and 0.5 to 0.7 respectively.

4. The process of claim 1, 2 or 3 wherein the olefin is a monoolefin selected from the group consisting of butylenes, propylenes, pentenes and mixtures thereof.

5. The process of claim 1 wherein said polymeric nitrogen-containing compound is selected from succinimides, amides, imides, esters containing nitrogen atoms, polyoxyazoline and imidazoline compounds.

6. The process of any one of claims 1 to 5 wherein the polymeric nitrogen-containing compound is selected from the reaction products of polyisobutenyl succinic anhydride, carboxylic acids, dicarboxylic acids, their corresponding anhydrides with

(a) polyethylene amines selected from diethylene triamine, triethylenetetramine; tetraethylenepentamine;

(b) hydroxyl containing amines, and;

(c) polyols in conjunction with (a) or (b) selected from pentaerythritol, and trimethylol propane.

7. The process of any one of the preceding claims wherein the amine is selected from polyethylene amines and hydroxyl-containing amines.

8. The process of claim 7 wherein the concentration of amine is from 0.5 to 10 per cent of the total weight of reactants.

9. The product produced by the process of any one of claims 1-8.

10. A process for making a hydrocarbon lubricant comprising adding to the hydrocarbon lubricant the product produced by the process of any one of claims 1 to 9 in a ratio of 5.7 to 1430 kg per 1000m³ of hydrocarbon lubricant.

11. A hydrocarbon lubricant produced by adding to a hydrocarbon lubricant the product produced by the process of any one of claims 1 to 10 in a ratio of 5.7 to 1430 kg per 100m³ of hydrocarbon lubricant.