Optimized composition for engine deposits and seals

Abstract

The present disclosure is directed to an additive composition for engine oils comprising; (a) an alkenyl-substituted succinic anhydride and (b) a polyamine compound and (C) Co-additives, wherein the reaction product has a ratio of the amide to imide infrared absorption peak areas of about 1:1.2 to about 1.6. The said reaction product is effective to prevent engine deposits along with protecting elastomeric seal material of an internal combustion engine and also improves piston cleanliness and ring sticking performance of an internal combustion engine.

Claims

1. A composition, which is characterized in that said composition comprising a compound derived from a reaction of (A) an alkenyl-substituted succinic anhydride and (B) a polyamine compound, and said composition further comprises (C) co-additives; wherein said compound has a ratio of the amide to imide infrared absorption peak areas of about 1:1.2 to about 1.6:1.

2. The composition as claimed in claim 1, wherein the molar ratio of the alkenyl-substituted succinic anhydride to the primary amino Nitrogen of the polyamine is less than 1.

3. The composition as claimed in claim 1, wherein the alkenyl-substituted succinic anhydride is a polyisobutylene succinic anhydride, which is present in a dispersant of polyisobutylene succinic imide or a dispersant blend comprising polyisobutylene succinic imide.

4. The composition as claimed in claim 3, wherein the said dispersant is a dispersant blend comprising polyisobutylene succinic imide.

5. The composition as claimed in claim 4, wherein said dispersant blend comprising polyisobutylene succinic imide further comprises a bisimide, with or without boration.

6. The composition as claimed in claim 5, wherein said bisimide is having a ratio of succinic to primary amine between 0.9 and 1.2.

7. The composition as claimed in claim 5, wherein the molar amount of boron in the bisimide dispersant is in the range of 0.01-250% moles of Nitrogen in the bisimide dispersant.

8. The composition as claimed in claim 3, wherein the alkenyl of the alkenyl-substituted succinic anhydride is a polyisobutylene group having a number average molecular weight of about 1400 to about 2500.

9. The composition as claimed in claim 1, wherein the moles of anhydride in the alkenyl-substituted succinic anhydride and the primary amino Nitrogen in the polyamine are present in the reaction in a molar ratio of about 0.4 to about 0.9.

10. The composition as claimed in claim 1, wherein the polyamine is selected from the group comprising of ethylenediamine, diethylenetriamine, triethylenetetramine, trimethyl amine, n-propylamine, isopropyl amine, tetraethylenepentamine, pentaethylenehexamine, polyethylene polyamine, and mixtures of two or more thereof.

11. The composition as claimed in claim 1, wherein the polyamine is a polyethylenepolyamine.

12. A process for making the compositions as claimed in claim 1, comprising (1) reacting an alkenyl-substituted succinic anhydride with an amine at 130-160 C. forming an imide and (2) the product formed is aged at a temperature ranging from 6080 C. for a period ranging from 0.5-4 weeks.

13. An additive package, comprising the composition as claimed in claim 1 in an amount ranging from 1-12 wt %.

14. The composition as claimed in claim 1, wherein the co-additives include from the group comprising of detergents, dispersants, ZDDP, antioxidants, friction reducers and antifoament.

15. The composition as claimed in claim 14, wherein the said detergent is an overbased metal compound present in a range of 1.45-2% w/w.

16. The composition as claimed in claim 15, wherein the overbased metal compound is an overbased calcium sulphonate.

17. The composition as claimed in claim 14, wherein the said ZDDP is present in a range of 0.25-1.5% w/w.

18. The composition as claimed in claim 17, wherein the alkyl group present in ZDDP has same or different hydrocarbyl radicals containing from 2-8 carbon atoms.

19. The composition as claimed in claim 14, wherein said Friction modifier is present in a range of 0.25-0.5% w/w.

20. The composition as claimed in claim 19, wherein said friction modifier is molybdenum based friction modifier.

21. The composition as claimed in claim 14, wherein said antioxidant is present in a range of 0.5-1.5 w/w.

22. The composition as claimed in claim 21, wherein said antioxidant is selected from the group consisting of diphenyl amines and alkyl derivatives having from about 4 to 20 carbon atoms in the alkyl group.

23. A method for preventing the deposits, comprising the addition of the composition as claimed in claim 1 to the engine oil.

24. A method for protecting elastomeric seal material in the engine, comprising the addition of the composition as claimed in claim 1 to the engine oil.

25. A method for improving piston cleanliness and ring sticking performance of engine oil, comprising the addition of the composition as claimed in claim 1 to the engine oil.

Description

DETAILED DESCRIPTION OF THE PRESENT INVENTION

(1) The present invention provides a new additive which is effective to prevent engine deposits along with protecting elastomeric seal material of an internal combustion engine and also improves piston cleanliness and ring sticking performance of an internal combustion engine, comprising; (A) an alkenyl-substituted succinic anhydride, (B) a polyamine compound and (C) Co-additives.

(2) Component A (Succinimide Dispersants)

(3) The succinimides, for example, include alkenyl succinimides comprising the reaction products obtained by reacting an alkenyl succinic anhydride, acid, acid-ester or lower alkyl ester with an amine containing at least one primary amine group. The alkenyl succinic anhydride may be prepared readily by heating a mixture of olefin and maleic anhydride to about 180-220 C. The olefin is, in an embodiment, a polymer or copolymer of a lower monoolefin such as ethylene, propylene, isobutene and the like. In another embodiment the source of alkenyl group is from polyisobutene having a molecular weight up to 5,000 or higher. In another embodiment the alkenyl is a polyisobutene group having a molecular weight of about 500-5,000 and most preferably about 1300-2,500.

(4) Component B (Polyamines)

(5) The preferred polyamines used in the practice of this invention are the alkylene polyamines represented by the formula H.sub.2N(CH.sub.2)n(NH(CH.sub.2)n)mNH.sub.2, wherein n is 2 to 10 (preferably 2 to 4, more preferably 2 to 3, and most preferably 2) and m is 0 to 10, (preferably 1 to 6). Illustrative are ethylene diamine, diethylene triamine, triethylenetetramine, tetraethylenepentamine, spermine, pentaethylene hexamine, propylene diamine (1,3-propanediamine), butylene diamine (1,4-butanediamine), hexamethylene diamine (1,6-hexanediamine), decamethylene diamine (1,10-decanediamine), and the like. In some embodiments, the polyamine is a fatty diamine. In some embodiments, the fatty diamine is at least one selected from the group consisting of N-octyldiaminoalkanes, N-decyldiaminoalkanes, N-dodecyl diaminoalkanes, N-tetradecyldiaminoalkanes, N-hexadecyldiaminoalkanes, N-octadecyldiaminoalkanes, N-stearyldiaminoalkanes, N-oleyldiaminoalkanes, N-tallow diaminoalkanes, N-cocoyldiaminoalkanes, and N-soya diaminoalkanes.

(6) Component C (Co-Additive)

(7) The composition may include one or more co-additives to provide certain performance characteristics. Examples of such co-additives are dispersants, detergents, metal rust inhibitors, viscosity index improvers, corrosion inhibitors, oxidation inhibitors, friction modifiers, anti-foaming agents, anti-wear agents, base oils and pour point depressants. Some are discussed in further detail below.

(8) Base Oils

(9) The term Group I base oil as used herein refers to a petroleum derived lubricating base oil having a saturates content of less than 90 wt. % (as determined by ASTM D 2007) and/or a total sulfur content of greater than 300 ppm (as determined by ASTM D 2622, ASTM D 4294, ASTM D 4297 or ASTM D 3120) and has a viscosity index (VI) of greater than or equal to 80 and less than 120 (as determined by ASTM D 2270).

(10) In general, a Group II base oil and Group III base oil can be any petroleum derived base oil of lubricating viscosity as defined in API Publication 1509, 14th Edition, Addendum 1, December 1998. API guidelines define a base stock as a lubricant component that may be manufactured using a variety of different processes. Group II base oils generally refer to a petroleum derived lubricating base oil having a total sulfur content equal to or less than 300 parts per million (ppm) (as determined by ASTM D 2622, ASTM D 4294, ASTM D 4927 or ASTM D 3120), a saturates content equal to or greater than 90 weight percent (as determined by ASTM D 2007), and a viscosity index (VI) of between 80 and 120 (as determined by ASTM D 2270).

(11) Group III base oils generally have less than 300 ppm sulfur, saturates content greater than 90 weight percent, and a VI of 120 or greater. In one embodiment, the Group III base stock contains at least about 95% by weight saturated hydrocarbons. In another embodiment, the Group III base stock contains at least about 99% by weight saturated hydrocarbons.

(12) Metal Sulphonate Detergent

(13) Overbased detergents are known in the art. Overbased materials otherwise referred to as overbased or superbased salts are generally single phase, homogeneous systems characterized by a metal content in excess of that which would be present for neutralization according to the stoichiometry of the metal and the particular acidic organic compound reacted with the metal. The overbased materials are prepared by reacting an acidic material (typically an inorganic acid or lower carboxylic acid, typically carbon dioxide) with a mixture comprising an acidic organic compound, a reaction medium comprising at least one inert, organic solvent (mineral oil, naphtha, toluene, xylene, etc.) for said acidic organic material, a stoichiometric excess of a metal base, and a promoter such as a calcium chloride, acetic acid, phenol or alcohol.

(14) Overbased sulphonates typically have a TBN of 250 to 600 mg KOH/gm, or 300 to 500. The metal sulphonate detergent may be an alkaline earth metal or alkali metal sulphonate. For example the metal may be sodium, calcium, barium, or magnesium. Typically other detergent may be sodium, calcium, or magnesium containing detergent (typically, calcium, or magnesium containing detergent). In one embodiment the metal may be calcium.

(15) Friction Modifier

(16) Friction modifiers and fuel economy agents that are compatible with the other ingredients of the final oil may also be included. Examples of such materials include oil-soluble organo-molybdenum compounds, such oil soluble organo-molybdenum compounds include dithiocarbamates, dithiophosphates, dithiophosphinates, xanthates, thioxanthates, sulfides, and the like, and mixtures thereof.

(17) Particularly preferred are molybdenum dithiocarbamates. Additionally, the molybdenum compound may be an acidic molybdenum compound. These compounds will react with a basic nitrogen compound as measured by ASTM test D-664 or D-2896 titration procedure and are typically hexavalent. Included are molybdic acid, ammonium molybdate, sodium molybdate, potassium molybdate, and other alkaline metal molybdates and other molybdenum salts, e.g., hydrogen sodium molybdate, MoOCl4, MoO2Br2, Mo2O3Cl6, molybdenum trioxide or similar acidic molybdenum compounds.

(18) Antiwear

(19) ZDDP is conventionally added to lubricating oil compositions in amounts of 0.1 to 10, preferably 0.2 to 2 wt. %, based upon the total weight of the lubricating oil composition. They may be prepared in accordance with known techniques. The preferred zinc dihydrocarbyl dithiophosphates are oil soluble salts of dihydrocarbyl dithiophosphoric acids and may be represented by the following formula:

(20) ##STR00001##

(21) wherein R and R may be the same or different hydrocarbyl radicals containing from 1 to 18, preferably 2 to 12, carbon atoms and including radicals such as alkyl, alkenyl, aryl, arylalkyl, alkaryl and cycloaliphatic radicals. Particularly preferred as R and R groups are alkyl groups of 2 to 8 carbon atoms. Thus, the radicals may, for example, be ethyl, n-propyl, i-propyl, n-butyl, i-butyl, sec-butyl, amyl, n-hexyl, thexyl, n-octyl, decyl, dodecyl, octadecyl, 2-ethylhexyl, phenyl, butylphenyl, cyclohexyl, methylcyclopentyl, propenyl, butenyl. In order to obtain oil solubility, the total number of carbon atoms (i.e. R and R) in the dithiophosphoric acid will generally be about 5 or greater. The zinc dihydrocarbyl dithiophosphate can therefore comprise zinc dialkyl dithiophosphates.

(22) Antioxidants

(23) Antioxidants or oxidation inhibitors are used to minimize the effect of oil deterioration that occurs when hot oil is contacted with air. The degree and rate of oxidation will depend on temperature, air and oil flow rates and, of particular importance, on the presence of metals that may catalytically promote oxidation. Antioxidants generally function by prevention of peroxide chain reaction and/or metal catalyst deactivation. They prevent the formation of acid sludges, darkening of the oil and increases in viscosity due to the formation of polymeric materials.

(24) Non-limiting examples of suitable oxidation resistance (antioxidant) and thermal stability improvers are diphenly-, dinaphtyl-, and phenyl-naphthyl-amines, in which the phenyl and naphthyl groups can be substituted, for example, N,N-diphenyl phenylenediamine, p-octyldiphenylamine, p-dioctyldiphenylamine, alkylated diphenylamine, alkylated phenyl alpha naphthylamine, N-phenyl-1-naphthyl amine, N-phenyl-2-naphthyl amine, N-(p-dodecyl)-phenyl-2-naphthyl amine, di-1-naphthylamine, and di-2-naphthylamine; phenothazines such as N-alkylphenothiazines; imino(-bisbenzyl); hindered phenols such as 6-(t-butyl)phenol, 2,6-di-(t-butyl)phenol, 4-methyl-2,6-di-(t-butyl)phenol, 4,4-methylenebis(2,6-di-{t-butyl}-phenol), esters of 3,5-di-tert-butyl-4-hydroxyhydrocinnamic acid, thiodiethylene bis-(3,5-di-tert-butyl-4-hydroxy) hydrocinnamate, esters of [[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl]thio]acetic acid and the like.

(25) TABLE-US-00001 TABLE 1 Finished Oil Formulation More Most Preferred Preferred Preferred COMPONENTS, Wt % Range Range Range 2300M. Wt. Borated Dispersant .sup.3-6 2-4 1.5-2.5 2300M. Wt. Monosuccinimide .sup.3-6 2-4 1.5-2.5 C2/6 1 ZDDP 1.5-3 .sup.1-1.5 0.25-1 C6/4 2 ZDDP 2.5-5 1.5-2.5 0.5-1.5 Organo metallic Friction 1-2.5 .5-1 0.25-.5 modifier Diphenylamine Antioxidant 2.5-5 1.5-2.5 0.5-1.5 Phenolic ester Antioxidant 2.5-5 1.5-2.5 0.45-1.5 Si Defoamer .5-1 .25-.5 .05-.1 Base Oil 1.5-3 .sup.1-1.5 0.20-1 300BN Ca Sulfonate .sup.3-6 2-4 1.20-2

(26) In forming the formulation of this invention, the finished oil will usually contain above described components.

EXAMPLES

Example1

(27) The reaction of the polyisobutylene and the polyamine was carried out in a solvent in which the reactants and the intermediates were readily dissolved; the reaction was maintained at a temperature of 130-160 C. to result an amide.

(28) The product formed was then aged at a temperature ranging from 60-80 C. for a period ranging from 0.5-4 weeks.

(29) The reaction product is characterized by an FTIR spectrum having peak intensity in a region of from about 1549 cm-1 to about 1703 cm-1, wherein said reaction product has a ratio of the amide to imide infrared absorption peak areas of about 1:1.2 to about 1.6.

Example2

(30) MHT-4 TEOST Bench Test

(31) The TEOST MHT approach was designed to simulate the deposit-forming tendencies of engine oil in the piston-ring belt and upper piston crown area. The MHT-4 TEOST (ASTM D7097) is a bench test used to evaluate oil performance relative to forming Moderately High Temperature Piston Deposits when subjected to high power and temperature operating conditions. The performance parameter is the weight of deposits on a heated metal rod.

(32) Results

(33) TABLE-US-00002 Result Upper Limit (Instant Sl. no Test Sample (SN/GF-5) Formulation) 1 Instant Composition 35 16

Example3

(34) KHT Bench Test

(35) The Hot Tube Test evaluates the high temperature stability of a lubricant. Oil droplets are pushed up by air inside a heated narrow glass capillary tube and the thin film oxidative stability of the lubricant is measured by the degree of lacquer formation on the glass tube, the resulting colour of the tube being rated on a scale of 0-10. A rating of 0 refers to heavy deposit formation and a rating of 10 means a clean glass tube at the end of the test. The method is described in SAE paper 840262. The level of lacquer formation in the tube reflects the high temperature stability of the oil and its tendency during service to form deposits in high temperature areas of the engine.

(36) Results

(37) TABLE-US-00003 Result Rating (Instant Sl. no Test Sample @280 Formulation) 1 Instant Composition 0-10 6

Example4

(38) Sequence IV A (ASTM D 6891)

(39) This test method measures the ability of crankcase oil to control camshaft lobe wear for spark-ignition engines equipped with an overhead valve-train and sliding cam followers. This test method is designed to simulate extended engine idling vehicle operation. The primary result is camshaft lobe wear. Secondary results include cam lobe nose wear and measurement of iron wear metal concentration in the used engine oil. This test method was developed to evaluate automotive lubricant's effect on controlling cam lobe wear for overhead valve-train equipped engines with sliding cam followers.

(40) TABLE-US-00004 RESULTS S. (Instant No PARAMETERS REQUIREMENT Formulation) STATUS 1 Cam Wear Avg, m Max. 120 15.73 PASS

Example5

(41) Sequence III H

(42) This test method evaluates automotive engine oils for certain high-temperature performance characteristics, including oil thickening, varnish deposition, oil consumption, as well as engine wear. Such oils include both single viscosity grade and multi viscosity grade oils that are used in both spark-ignition, gasoline-fueled engines, as well as in diesel engines. This test method was developed to evaluate automotive engine oils for protection against oil thickening and engine wear during moderately high-speed, high-temperature service.

(43) TABLE-US-00005 SEQUENCE IIIH RESULTS S. PROPOSED (Instant No. PARAMETERS LIMIT Formulation) STATUS 1 K.V. Increase 150 max. 34.50 PASS @40 deg C., % 2 Avg. Weighted 3.7 min. 5.09 PASS Piston Deposit, merit SEQUENCE IIIH-A RESULTS S. (Instant No. PARAMETERS REQUIREMENT Composition) STATUS 1 MRV, cP 60,000 max. 19,720 PASS 2 Yield Stress, Pa Y <= 35 Y <= 35 PASS SEQUENCE IIIH-B RESULTS S. PROPOSED (Instant No. PARAMETERS LIMIT Composition) STATUS 1 Phosphorous 80.5 min. 80.49 PASS Retention, %

Example6

(44) Sequence VG Test Engine (ASTM D 6593)

(45) This test method correlated with vehicles used in stop-and-go service prior to 1996, particularly with regards to sludge and varnish formation. This test method is used to evaluate an automotive engine oil's control of engine deposits under operating conditions deliberately selected to accelerate deposit formation. It is one of the test methods required to evaluate oils intended to satisfy the API SL performance category. The test stand is equipped to control speed, torque, AFR, and various other operating parameters. The test is run for a total of 216 h, consisting of 54 cycles of 4 h each. Each cycle consists of three stages. While the operating conditions are varied within each cycle, overall, they can be characterized as a mixture of low-temperature and moderate-temperature, light and medium duty operating conditions.

(46) TABLE-US-00006 RESULTS S. (Instant No PARAMETERS REQUIREMENT Formulation) STATUS 1 Avg. Engine sludge, Min. 8 9.33 PASS merit 2 Rocker arm cover Min. 8.3 9.48 PASS sludge, merit 3 Avg. Piston Skirt Min. 7.5 8.97 PASS Varnish, merit 4 Avg. Engine Min. 8.9 9.59 PASS Varnish, merit 5 Oil Screen Max. 15.sup. 2.00 PASS clogging, % 6 Number of hot 0 0 PASS stuck rings

Example7

(47) Sequence VIII Test Engine (ASTM D 6709)

(48) This test method covers the evaluation of automotive engine oils both single viscosity grade and multi viscosity grades intended for use in spark-ignition gasoline engines. The test procedure is conducted using a carburetted, spark-ignition Cooperative Lubrication Research (CLR) Oil Test Engine (also referred to as the Sequence VIII test engine in this test method) run on unleaded fuel. An oil is evaluated for its ability to protect the engine and the oil from deterioration under high-temperature and severe service conditions. The test method can also be used to evaluate the viscosity stability of multi viscosity-graded oils. This test method is used to evaluate automotive engine oils for protection of engines against bearing weight loss and used to evaluate the SIG capabilities of multi viscosity-graded oils.

(49) TABLE-US-00007 Results S. (Instant No Parameters Requirement Formulation) Status 1 Bearing weight loss, mg Max. 26 4.2 PASS 2 Stripped viscosity cSt at Stay in grade - 10.44 PASS 100 deg C. 9.3 - 12.5 cSt

Example8

(50) GF 5 Test (ASTM D 7216)

(51) Standard Test Method for Determining Automotive Engine Oil Compatibility with Typical Seal Elastomers

(52) Some engine oil formulations have been shown to lack compatibility with certain elastomers used for seals in automotive engines. These deleterious effects on the elastomer are greatest with new engine oils (that is, oils that have not been exposed to an engine's operating environment) and when the exposure is at elevated temperatures. This test method covers quantitative procedures for the evaluation of the compatibility of automotive engine oils with several reference elastomers typical of those used in the sealing materials in contact with these oils. Compatibility is evaluated by determining the changes in volume, Durometer A hardness and tensile properties when the elastomer specimens are immersed in the oil for a specified time and temperature. Effective sealing action requires that the physical properties of elastomers used for any seal have a high level of resistance to the liquid or oil in which they are immersed. When such a high level of resistance exists, the elastomer is said to be compatible with the liquid or oil. This test method provides a preliminary or first order evaluation of oil/elastomer compatibility only.

(53) TABLE-US-00008 Results Sl. Instant No. Parameters Requirements Formulation Status SAE J2643 ACM-1 1 Tensile Strength 40 to 40 6.4 Pass [Mpa], % 2 Elongation Rupture, % To report 7.7 3 Hardness Shore A, Points 10 to 10 6.0 Pass 4 Volume Variation, % 5 to 9 1.27 Pass SAE J2643 HNBR-1 1 Tensile Strength 20 to 15 2.5 Pass [Mpa], % 2 Elongation Rupture, % To report 17.5 3 Hardness Shore A, Points 10 to 5 0.0 Pass 4 Volume Variation, % 5 to 10 0.08 Pass SAE J2643 VMQ-1 1 Tensile Strength 50 to 5 28.7 Pass [Mpa], % 2 Elongation Rupture, % To report 17.7 3 Hardness Shore A, Points 30 to 10 17.0 Pass 4 Volume Variation, % 5 to 40 23.12 Pass SAE J2643 FKM-1 1 Tensile Strength 65 to 10 22.1 Pass [Mpa], % 2 Elongation Rupture, % To report 26.4 3 Hardness Shore A, Points 6 to 6 0.0 Pass 4 Volume Variation, % 2 to 3 0.93 Pass SAE J2643 AEM-1 1 Tensile Strength 30 to 30 6.5 Pass [Mpa], % 2 Elongation Rupture, % To report 28.8 3 Hardness Shore A, Points 20 to 10 8.0 Pass 4 Volume Variation, % 5 to 30 17.01 Pass