JPH04114097A - Lubricating oil not containing metal - Google Patents

Abstract

PURPOSE: To provide a biodegradable lubricant compsn. containing no heavy metal and having improved environmental toterance prepared by compounding an anti-wear additive containing S, etc., but not containing metal and a corrosion inhibitor of a specific aminosuccinic ester form.

CONSTITUTION: The objective compsn. contains an abrasion-resistant or load- carrying additive containing sulfur and/or phosphorus but not containing metal (e.g; diphenyl thiophosphate) (A) and a corrosion inhibitor of an aminosuccinic ester form represented by the formula (wherein R₁ and R₂ are each a 1-30C alkyl, R₃ to R₅ are each H or a 1-4C alkyl, R₆ and R₇ are each H, a 1-30C alkyl or acyl derived from 1-30C carboxylic acid and at least one of R₆ and R₇ is an acyl).

COPYRIGHT: (C)1992,JPO

Description

[Detailed description of the invention]

[0001] The present invention relates to lubricating oil compositions, and more particularly to lubricating oil compositions that can be used as hydraulic fluids. [0002] Lubricating oil compositions typically include various additives that are incorporated to improve the performance of the lubricating oil in the environments in which it is used. Such additives often contain transition metals. For environmental reasons, as is well known, there is a current legal requirement to reduce the use of often toxic transition metals. For example, lubricating oil used as hydraulic fluid is
Contains zinc dialkyldithiophosphate (so-called 'ZDDP') as an anti-wear additive.It would be desirable to be able to provide a zinc-free hydraulic oil. This is an acute problem when hydraulic oils are used in agriculture or arboriculture where there is a possibility of spillage and contamination of the ground and drainage or connected river systems.[0003] ] There is also a practical desire to be able to provide an additive system that is suitable for use in all types of hydraulic fluids, regardless of the particular equipment in which it is used. Universal anti-wear (UAW) additive systems for use in hydraulic fluids such as
n) It must be able to provide a hydraulic oil that can pass HFO standards and Vickers vane pump standards. It is further required that such hydraulic fluids must pass a load rating of greater than 10 in the FZG test, which is described in more detail below. [0004] Pressure fluids that are not mixed with ZDDP do not necessarily have the performance required in the FZG test. [0005] A metal-free universal antiwear additive suitable for use in lubricating oil compositions to be used, for example, in piston and screw compressors, industrial gear equipment, and more particularly in hydraulic oils. There is a need for drug systems. [0006] In accordance with the present invention, a lubricating oil composition comprises (a) a sulfur- and/or phosphorus-containing, metal-free anti-wear or load-bearing additive;
and (b) formula % formula %]

[4] In the above formula, R1 and R2 are each 1 to 30, preferably 1
alkyl of 1 to 12 carbon atoms, R3, R4, and R5 are each hydrogen or alkyl of 1 to 4 carbon atoms, and R6 and R7 are each hydrogen, alkyl of 1 to 30 carbon atoms, or the highest carbon It contains a corrosion inhibitor in the form of an aminosuccinic ester of an acyl group derived from a saturated or unsaturated carboxylic acid of 30 atoms, at least one of R6 and R7 being the acyl group. Preferably R1 and R2 are each alkyl of 3 to 6 carbon atoms, such as isobutyl, and R3, R4 and R5
are each hydrogen, and R6 and R7 are each an alkyl group of 15 to 20 carbon atoms or an acyl group derived from a saturated or unsaturated dicarboxylic acid containing 4 to 10 carbon atoms, such as octadecyl, octadecenyl or 3-carboxy- 1-oxo-2-propenyl. Particularly preferred component (b) is aspartic acid, N(3-hydroxy-
1-oxo-2-propenyl)-N-octadecyl-bis(2-medelpropyl) ester. [0008] Can be any one of the phosphorus-containing additives. [0009] If the alkyl group contains up to 12 carbon atoms, alkylphenyl, arylalkyl, or aliphatic, e.g.
such as alkyl and di-hydrocarbyl thiophosphates, which can be alkyl containing up to 2 carbon atoms;
It is a sulfurized hydrocarbyl phosphite. Examples of such sulfurized hydrocarbyl phosphites include diphenylthiophosphate, dinonylphenylthiophosphate, di-n-butylthiophosphate-isobutylthiophosphate and di-2[00101], isobutyl, n-pentyl, n. -hexyl, 2-ethylhexyl or n-do. Hydrocarbyl groups can also be alkenyl or cycloalkyl groups. [0011] Other metal-free anti-wear or load-bearing additives that can be used in the present invention also include sulfurized alkenes, such as sulfurized isophthenes containing 42 to 48 weight percent sulfur, or oleic acids. or sulfurized carboxylic acids or esters thereof, such as fatty acids such as lyluic acid, eg sulfurized vegetable oils such as rapeseed or lard oil, or animal fats. [0012] A suitable commercially available sulfurized fatty acid ester material of this type is Sulperm 10
S (Keil Chemical
]) and EP oil GEIO (Hornett
] )including. These are generally 9.5% and about 8% respectively.
．． Contains 5-9.5% sulfur. [0013] Dialkyl polysulfides such as t-nonyl trisulfide or t-dodecylpentasulfide can also be used as anti-wear or load-bearing additives. [0014] Sulfur- or phosphorus-containing anti-wear or load-bearing additives are disclosed in our UK Patent Application No. 8829597.7 (Patent Application No. 8
Advantageously, it is produced by the method described in British Patent No. GB-A No. 2226028, ongoing and published as No. 928565.4). These sulfur- or phosphorus-containing anti-wear or load-bearing additives are

[5] In the above formula, the residues R are the same or different and each is a substituted or unsubstituted hydrocarbyl group of up to 20 carbon atoms, and R1, R2 and R3 are each hydrogen or up to Amine salts of phosphorus thio acids which are substituted or unsubstituted hydrocarbyl groups of up to 22 carbon atoms, in which no more than one of R1, R2 and R3 is hydrogen. When prepared by the method of the above-mentioned patent application, such salts have a purity of at least 95% and have little reactivity towards copper and are of the formula (
Phosphite esters of RO)2POH or their amine salts are less than 3%. Suitable such amine salts are R
is alkyl or phenyl of 3 to 8 carbon atoms,
each of R1, R2 and R3 is hydrogen or an alkyl, cycloalkyl or alkenyl residue of 4 to 22 carbon atoms, and no more than one of RR and R is hydrogen;
It is an amine salt. Preferably 1'23 is R is phenyl, R and R are hydrogen, and R
is mixed C12-C14 tertiary alkyl. [0016] Such amine salts form a mixture of sulfur and amine in the liquid state, and the sulfur reacts with the ester, but at a reaction temperature of 13
At least an equivalent amount of phosphite of formula (RO)2POH is added to the mixture to the amount of sulfur under conditions that the temperature does not rise above 0°C, and the reaction is subsequently continued until solid sulfur is virtually eliminated from the reaction mixture. Manufactured by If necessary, the amount of amine is adjusted so that the total amount of amine is at least equivalent to the amount of phosphite. [0017] Compatible mixtures of such anti-wear or load-bearing additives can of course also be used. [0018] The proportion of components (a) and (b) in the lubricating oil composition of the present invention is from 0.05% to 3% of the anti-wear or load-bearing additive.
, preferably from 0.1% to 1.5%, and the corrosion inhibitor from 0.002% to 0.5%, preferably from 0.05 to 0.25%, and the above percentages is the weight percent relative to the total weight of the lubricating oil composition. [0019] The lubricating oil composition can include any mineral or non-mineral oil suitable as a lubricating oil as a base oil, or more particularly as a hydraulic oil. These stocks include paraffinic lubricating oil stocks of mineral origin, polyalphaolefins, synthetic lubricating esters such as hydrogenated polydecenes, dialkyl adipates and azelates (generally one alkyl group in each
from 20 carbon atoms (e.g. dioctyl adipate, dinonyl adipate or di-2-ethyl-hexyl azelate) and particularly lubricating vegetable oils such as rapeseed oil, jojoba oil, cottonseed oil, bean oil or palm pond oil. Contains biogenic oils. Ingredients as above (a
It is a particular advantage of the invention that the combination of ) and (b) is compatible with a variety of natural, especially vegetable-based oils suitable as hydraulic oils. Such natural oils are biodegradable, and therefore, the present invention provides an effective hydraulic fluid that uses biodegradable raw materials such as rapeseed oil or jojoba oil as a base oil and incorporates additives that do not contain heavy metals. It is possible to provide the following. [0020] When used in an acidic environment, the lubricating oil composition of the present invention contains a third component, namely (C) alkylbenzene sulfonic acid, alkylnaphthalene sulfonic acid, petroleum sulfonic acid (
It may be desirable to incorporate alkaline earth metal salts of petroleum 5ulphonate), alkyl sulfur carbonates, or alkyl salicylic acids. This material is usually overbased and can also be sulfided. Sulfurized overbased calcium alkyl phenate whose alkyl group is paranonyl, (a
lkylphenate) or calcium dinonylnaphthalene sulfonate can be suitably used. The proportion of such additives incorporated is usually in the range 0.005 to 0.50% based on the total weight of the composition. Although such compositions are not ashless, they are free of heavy metals and thus accomplish one of the important objectives of the present invention. [0021] The lubricating oil compositions of the present invention may contain other additives conventionally used in lubricating oils, such as: (i) additional corrosion inhibitors, such as amine salts of carboxylic acids, such as octylamine octanoate; , condensation products of fatty acids and polyamines such as dodecenylsuccinic acid or anhydride and oleic acid, e.g. triethylenetetramine, and alkenylsuccinic acids and polyglycols in which the alkenyl residue contains 8 to 24 carbon atoms. half-esters with alcohols, (ii) ashless dispersants, especially reaction products such as those produced by the reaction of polyolefin maleic anhydrides with polyalkylene polyamines such as triethylenetetramine or tetraethylenepentamine; In such dispersants, the polyolefin generally has a molecular weight of 900 to 120
It is a polyisobutyne with a number average molecular weight of 0. [0022] Under certain circumstances, it may be advantageous to boron-treat such ashless dispersants. Boron is not preferred for use in the compositions of the present invention since it forms ash, which is a non-metal. [0023] (i ii) For example, 2,6-tert,-butylphenol tert. -butyl-4-methylphenol, and 4,4'-methylenebis(2.6-G ter
t. -butylphenol), sulfurized phenolic antioxidants such as 4,4'-thiobis(6-tert.-butyl-O-cresol), and di(nonylphenyl)amines and octylated Antioxidants including aromatic amines such as phenyl-alpha naphthylamine. Mixtures of phenolic antioxidants and aromatic amine antioxidants (e.g. ethyl [Eth
yl] R antioxidant 728 and/or 733 and Naugalube 4 3 8 L)
is suitable. [0024] (iv) Copper deactivators, such as benzotriazole and its derivatives, thiadiazole and its derivatives, or tricresyl phosphite. [0025] (V) Demulsifiers, more particularly surfactants that are preferably ashless, such as nonionic surfactants such as polyglycols. [0026] (vi) Viscosity index improvers, such as poly(alkyl-
methacrylate) and olefin copolymers such as ethylene/propylene and styrene/isoprene copolymers,
and dispersible viscosity index improvers such as copolymers of alkyl methacrylate and N-vinylpyrrolidone and olefin copolymers grafted with nitrogen-containing monomers such as diallylformamide. [0027] (vii) Pour point depressants such as poly(alkyl methacrylates). [0028] (viii) Antifoam agents, such as silicone and poly(alkyl acrylate) based products, can be conveniently incorporated. [0029] These additional components must, of course, be compatible with components (a) and (b), provided that they are used in conventional proportions. [00301 The compositions of the present invention may contain components (a) and (b) as described above, alone or preferably with a relatively small amount of a suitable base oil to facilitate handling, and optionally one or more. Conveniently, it is supplied to the formulator of the final lubricating oil composition in the form of an additive concentrate containing it together with the additional ingredients mentioned above. Components (a) and (b) in such concentrates are such that when the concentrate is incorporated into the base oil, the concentration of component (a) is between 0.02 and 3% by weight relative to the total weight of the lubricating oil composition. % by weight and preferably 0.1
and the concentration of (b) is between 0.002 and 0.5% and preferably between 0.05 and 0.25% by weight relative to the total weight of the lubricating oil composition. It is a ratio that provides something. The ratio of (a) and (b) in such a concentrate is preferably from 30:1 to 0.4:1. Components in the concentrate (b
) is preferably 0.1 to 5%, especially 0.1 to 10%, and most usually 1 to 5% by weight of the concentrate. [003] The following examples illustrate and explain the invention. [0032]

Example 1 Hydraulic oil formulations range from 41.4 to 50.6 c at 40°C
It was manufactured using 15O46 mineral oil having a kinematic viscosity of St as the base oil. The incorporated additives are listed in Tables II and II below. Each formulation is for clarity and IP135
B Corrosion test, evaluated by test method. The latter test method is 30
It involves immersing a steel cylinder into a mixture of 0 ml of hydraulic oil and 30 ml of artificial seawater at a temperature of 60° C. while stirring. Tests were conducted on two samples for 24 hours using each formulation, and the immersed steel samples were then inspected for signs of rust. In order to pass, there must be no rust visible on the sample. [0033] The formulation was also tested by FZG test (IP334/79). In this test, two spur gears are
During each test phase of 5 minutes, they were rotated together under oil lubrication. The relative torque between the gears was increased by a fixed amount after each step and the gears were rotated for a given period of time and then inspected for fatigue or damage. The test results were evaluated by a final passing stage and an initial failing stage. To be satisfactory, the passing grade must be higher than 10. [00341 Tables II and II below show the compositions of the hydraulic fluids tested and the results obtained for each. Formulation 4.5.6
．． 7 and 10 are according to the invention. Other formulations are for comparison. [0035]

Table 1 Weight percent formulation of 1 condensation in l5O46 hydraulic base oil 1 Component Al 0.07 Component A2 0.19 Component B Corrosion inhibitor, D 0.065 Corrosion inhibitor, E Corrosion inhibitor, E 0.07 0.07 0.07 0.07 0.10.
19 0.19 0.19 0.19 0.120.0
2 0.02 0.015 0.04 0.03 0.025 0.025 0,02 0.075 FZG load stage pass/1 fail P135B Test, test result 2 pass 9 pass/ test, no test 10 Fail 12 Pass 12 Pass 12 Pass Fail Fail No test Pass Pass
Pass Medium Severe No rust No rust No rust Rust Transparency of rust-blended oil Transparent Transparent Cloudy Transparent
Transparent Clear component A1 was Primene 81R salt of diphenylthiophosphate. [0036] Component A2 was a blend of 36% di-t-nonyl polysulfide and 64% sulfurized fatty ester. [0037] Component B is aspartic acid, N-(3-carboxy-2-
oxo-2-propenyl)-N-octadecyl-bis(
2-methylpropyl) ester. [0038] The corrosion inhibitor was a condensation product of dodecenylsuccinic acid and oleic acid with polyethylene polyamine. [0039] Corrosion inhibitor E was octylamine octanoate. [0040] Corrosion inhibitor F is modified imidacillin (Monamarus [Mon
amulse] CI). [0041] Formulations 1-6 contained the same concentrations of conventional antioxidants, copper quenchers, and demulse aids. [0042] Formulations 2 and 5 further included a conventional amount of a boronated polyisobutenyl succinimide ashless dispersant. In formulation 6, component A1 is described in British Patent GB-A No. 222602.
It was manufactured by the method described in No. 8. [0043]

Table 2: 15O46 Pressure Weight percent concentration in base oil 0.07 0.07 0.19 0.04 0,04 (C1) 0.04 (C1) Formulation Component A1 Component A2 Component B Activator C (C2) Corrosion inhibitor F Corrosion inhibitor G Transparency of corrosion inhibitor compounded oil IP135B test, test results FZG load stage passed / 11 passed / 11 passed / 11
Pass/Fail 12 Fail 12 Fail
12 Fail 0.07 0.19 0.03 0, O5 0, 04 (C1) Pass Cloudy 0.19 0.04 Pass 0.05 Transparent 0.05 Transparent Pass 0, 07 0.19 0.02 0. 0075 0,025 Transparent Pass 11 Pass/12 Fail Components A1, A2, B, D, and F were as shown in Table 3. [0044] Surfactant C1 was a high base calcium sulfide nonylphenate. [0045] Surfactant C2 was calcium dinonylnaphthalene sulfonate. [0046] Corrosion inhibitor G was butanedionic acid, sulfo-1,4-)lysosyl ester, sodium salt. [0047] Formulations 7.8 and 9 contained the same concentrations of conventional antioxidants, articulation activators, viscosity index improvers, and demulsification aids. [0048] Formulation 10 was similar to Formulation 7-9 but contained conventional amounts of boronated polyisobutenyl succinimide ashless dispersant and did not contain a viscosity index improver. [0049]

Example 2 Formulation 11 was prepared having the same composition as Formulation 6 described in Example 1, except that the base oil was rapeseed oil. FZG
The results obtained in the test, IP135B test, test and clarity test of the formulation were identical to those obtained with Formulation 6. [0050]

Example 3 Component A1 was used at a concentration of 0.11% by weight and component A2
Formulation 12 was prepared having the same composition as Formulation 6 described in Example 1, except that it consisted entirely of sulfurized fatty ester (Salperm 10S). Formulation 12 has the same F
ZG, IP135B, and clarity results were produced. In performance testing, Formulation 12 was tested with Haglans-Denison H
FO standard, Cincinnati Miracle
Passed the requirements of the P68, P69 and P70 standards and the picker vane pump standard.

Example 4 Formulation 13 was prepared by incorporating the additive components of Formulation 12 described in Example 3 at the same concentrations as Formulation 12 using rapeseed oil. Formulation 13 exhibited the same FZG, IP135B, and clarity results as Formulation 11 described in Example 2. Further testing showed that Formulation 13 complied with the Haglan-Z-Denison HF○ standard pump test requirements as well as the Cincinnati Milacron Thermal Stability Test Method 11A.
It was found that I+ was satisfied. In this latter test method, a copper rod and an iron rod are held in contact with each other under the surface of 200 ml of test oil in a beaker for 7 days at a constant temperature of 135°C. At the end of the test, it was found that passing scores were obtained for sludge formation, iron rod performance, and copper rod weight change. [0052] Main features and aspects of the present invention are as follows. [0053] 1, (a) a wear-resistant or load-bearing additive that does not contain metals containing sulfur and/or phosphorus, and (b) formula %]

[6] In the above formula, R and R are each alkyl of 1 to 30 carbon atoms, R3, R and R are each hydrogen or alkyl of 1 to 4 carbon atoms, and R6 and R7 are each hydrogen, an alkyl group of 1 to 30 carbon atoms, or an acyl group derived from a saturated or unsaturated carboxylic acid of up to 30 carbon atoms, and at least one of R and R is the acyl group; A lubricating oil composition comprising a corrosion inhibitor of the form. [0055] 2. In the aminosuccinic acid ester, R and R2 are each alkyl of 3 to 6 carbon atoms, and RR and R
are each hydrogen, and R6 and R7 are each 3 and 4
5 alkyl of 15 to 20 carbon atoms, or 4 to 10
The lubricating oil composition as described in 1 above, wherein the acyl group is derived from a saturated or unsaturated dicarboxylic acid of a carbon atom. [0056] 3. The lubricating oil composition according to 1 above, wherein the corrosion inhibitor is aspartic acid, N-(3-carboxy-1-oxo-2-propenyl)-N-octadecyl-bis(2-methylpropyl) ester. thing. [0057] 4. The metal-free anti-wear or load-bearing additive is a mono- and/or di-hydrocarbyl phosphate or phosphite in which the hydrocarbyl group is an alkyl of up to 12 carbon atoms; 4. The lubricating oil composition according to any one of items 1 to 3 above, which is an amine salt of phytophyte or a mixture thereof. [0058] 5. The metal-free anti-wear or load-bearing additive is a mono- or di-hydrocarbyl thiophosphate, or an amine salt thereof, in which the hydrocarbyl group is aryl, alkylaryl, arylalkyl or alkyl; The lubricating oil composition according to any one of items 1 to 3 above. [0059] 6. The thiophosphate is diphenylthiophosphate, dinonylphenylthiophosphate, di-n-butylthiophosphate, di-isobutylthiophosphate,
5. The lubricating oil composition according to 5 above, which is di-2-ethylhexylthiophosphate or a mixture thereof. [00601 7. Any one of 1 to 3 above, wherein the metal-free anti-wear or load-bearing additive is a trihydrocarbyl dithiophosphate in which the hydrocarbyl group is an aromatic, alkyl aromatic or aliphatic residue. The lubricating oil composition described in section. [0061] 8. The wear-resistant or load-bearing additive has the formula % formula %]

[7] In the above formula, the residues R are the same or different and each is a substituted or unsubstituted hydrocarbyl group of up to 20 carbon atoms, and RR and R3 are each 1' 2 hydrogen or 1 above, comprising an amine salt of 1.2 phosphorothioic acid, which is a substituted or unsubstituted hydrocarbyl group of up to 22 carbon atoms, and in which not more than one of RR and R3 is hydrogen. or 3
The lubricating oil composition according to any one of the above. [0063] 9. R is alkyl or phenyl of 3 to 8 carbon atoms, RR and R31'2 are each hydrogen or alkyl each of 4 to 20 carbon atoms,
Cycloalkyl or alkenyl residues, RR and R
The lubricating oil composition according to 1.28 above, wherein no two or more of 3 are hydrogen. [0064] 10. The wear-resistant or load-bearing additive is (i) a wear-resistant or load-bearing additive that does not contain at least one metal that contains phosphorus; and (ii) a wear-resistant or load-bearing additive that does not contain at least one metal that contains sulfur. 4. A lubricating oil composition according to any one of clauses 1 to 3, comprising a combination of wear or load-bearing additives. [0065] 11. The wear-resistant or load-bearing additive is (i) Formula % Formula %]

[8] In the above formula, the residues R are the same or different and each is a substituted or unsubstituted hydrocarbyl group of up to 20 carbon atoms, and RR and R3 are each hydrogen or amine salts of phosphorothioic acids, substituted or unsubstituted hydrocarbyl groups of up to 22 carbon atoms, in which no more than one of RR and R3 is hydrogen; and (ii) sulfurized The lubricating oil composition according to any one of items 1 to 3 above, ν), comprising a combination of fatty acid esters. [0067-12, the wear-resistant or load-bearing additive is of formula (i) [0068
]

embedded image (R○) P S OHN RIR2R3 In the above formula, the residue R is phenyl, R and R are hydrogen, and R
3 is a mixed C12-C14 tertiary alkyl, any of the above 1 to 3, comprising a combination of: (ii) a sulfurized fatty acid ester and (iii) a dialkyl polysulfide; The lubricating oil composition according to item 1. [0069] 13. The lubricant base oil raw material is a paraffinic lubricating oil raw material of mineral origin, a synthetic lubricating ester, or an oil of biological origin.
A lubricating oil composition according to any of the above items. [00701 14. The lubricating oil composition according to 13 above, wherein the base oil raw material is a biodegradable vegetable oil. 007/15. The lubricating oil composition according to 14 above, wherein the vegetable oil is rapeseed oil. [0072] 16, alkaline earth metal alkylbenzene sulfonate, alkaline earth metal alkylnaphthalene sulfonate,
Also including alkaline earth metal petroleum sulfonates, alkaline earth metal alkyl phenates, alkaline earth metal sulfurized phenates or alkaline earth metal alkyl salicylates,
A lubricating oil composition according to any of the above items. [0073] 17. The lubricating oil composition according to 16 above, wherein the ratio of the alkaline earth metal salt is within the range of 0.005 to 50% by weight based on the total weight of the lubricating oil composition. [0074] 18. The lubricant of any of the preceding paragraphs, comprising from 0.05 to 3% by weight of said anti-wear or load-bearing additive and from 0.002 to 0.5% by weight of said corrosion inhibitor. oil composition. [0075] 19. The lubricating oil composition of 18 above, comprising 0.1 to 1.5% by weight of an anti-wear or load-bearing additive and 0.05 to 0.25% by weight of a corrosion inhibitor. [0076] 20. The above, further comprising one or more additional corrosion inhibitors, ashless dispersants, antioxidants, articulation activators, demulsifiers, viscosity index improvers, pour point depressants, and/or antifoaming agents. The lubricating oil composition according to any of the above. [0077] 21. The lubricating oil composition according to any one of 1 to 20 above for use as a hydraulic oil. [0078] 22, (a) a metal-free wear-resistant or load-bearing additive containing at least one sulfur and/or phosphorus, and (b) formula %] [101 In the above formula, R and R are An additive concentrate comprising a corrosion inhibitor in the form of an aminosuccinic acid ester, each alkyl of 1 to 30 carbon atoms, selected from R3, an acyl group derived from a saturated or unsaturated carboxylic acid of up to 30 atoms. . [0080] 23. 22 above, wherein the wear-resistant or load-bearing additive is as specified in any of paragraphs 4 to 12 above.
Additive concentrates as described in . [0081] 24. The corrosion inhibitor is aspartic acid, N-(3-carboxy-1-oxo-2-propenyl)-N-octadecylrubis(2-methylpropyl) ester.

Claims (3)

[Claims] [Claim 1] (a) A wear-resistant or load-bearing additive that contains sulfur and/or phosphorus and does not contain metals, and (b) Formula [Claim 1] ▲There are mathematical formulas, chemical formulas, tables, etc.▼ In the above formula , R_1 and R_2 are each alkyl of 1 to 30 carbon atoms, R_3, R_4 and R_5 are each hydrogen or alkyl of 1 to 4 carbon atoms, and R
_6 and R_7 are each hydrogen, alkyl of 1 to 30 carbon atoms, or an acyl group derived from a saturated or unsaturated carboxylic acid of up to 30 carbon atoms, and at least one of R_6 and R_7 is the acyl group. A lubricating oil composition comprising a corrosion inhibitor in the form of an aminosuccinate ester. 2. The wear-resistant or load-bearing additive has the formula: (RO)_2PSO^-. HN^+R_1R_2R_3
In the above formula, the residues R are the same or different and each is a substituted or unsubstituted hydrocarbyl group of up to 20 carbon atoms, and R_1, R_2 and R_3 are each hydrogen or up to 22 carbon atoms. The lubricating oil according to claim 1, comprising an amine salt of a phosphorothioic acid, which is a substituted or unsubstituted hydrocarbyl group, and in which no more than one of R_1, R_2 and R_3 is hydrogen. Composition. [Claim 3] (a) A wear-resistant or load-bearing additive containing at least one kind of sulfur and/or phosphorus and containing no metal, and (b) Formula [Claim 3] ▲ Includes mathematical formulas, chemical formulas, tables, etc. ▼ In the above formula, R_1 and R_2 are each alkyl of 1 to 30 carbon atoms, R_3, R_4 and R_5 are each hydrogen or alkyl of 1 to 4 carbon atoms, and R
Each of _6 and R_7 is selected from hydrogen, alkyl of 1 to 30 carbon atoms, and acyl group derived from a saturated or unsaturated carboxylic acid of up to 30 carbon atoms, and at least one of R_6 and R_7 is An additive concentrate comprising a corrosion inhibitor in the form of an aminosuccinate ester of the acyl group.