JPH02242895A - Synthetic lubricant composition - Google Patents

Abstract

PURPOSE: To provide a lubricant compsn. which contains an arom. tricarboxylic acid triester as the main ingredient, an antiwear agent contg. a phosphate, and a small amt. of an org. additive package, does not leave behind residues in a combustion chamber, and does not generate ash.

CONSTITUTION: This compsn. contains 75-99 wt.% arom. tricarboxylic acid triester, 0.25-5 wt.% antiwear agent contg. a phosphate, and 0.1-5 wt.% org. additive package which does not contain a metallic group or component and does not leave behind residues in an engine when burned during operating the engine.

COPYRIGHT: (C)1990,JPO

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is for use in high temperature rotary engines using internally lubricated fuel, in which the lubricant is consumed and burned during operation. The present invention relates to synthetic lubricant compositions.

BACKGROUND OF THE INVENTION A variety of synthetic lubricants have been described in the patent and scientific literature.

Alkyl trimellitate compositions suitable for use as lubricants and hydraulic fluids are described in German patent application no.
No. 140.683 and abstracted in Chemical Abstracts Vol. 76 (1972) No. 115812c. A similar matter is described in Soviet Patent No. 525,663, Chemical Abstracts Vol. 86 (1977).
Abstracted in 92985b. A blend of pentaerythritol and trimellitic acid ester as the main component of a synthetic lubricating oil for jet engines is disclosed in British Patent Box 1.
No. 481,270.

U.S. Pat. No. 3,637,501 describes a complex ester made by the reaction of a neopentyl-type polyol, an aromatic polycarboxylic acid, and a mixture of aliphatic monocarboxylic acids. This is suitable for lubricating gas turbine engines.

Dialkyl diesters of the type consisting of mixtures of isophthalic and terephthalic acids are characterized in US Pat. No. 2,936,320 as superior synthetic oils.

U.S. Pat. No. 3,021,357 describes new dialkyl esters of 5t-alkylisophthalic acids suitable as plasticizers for synthetic liquid lubricants and synthetic polymeric resins. A gas turbine lubricant based on a blend of carboxylic acid esters (e.g. esters of phthalic acid and/or isophthalic acid) and low viscosity mineral oil comprises:
No. 3,912,640.

An example of a synthetic lubricant that has been tried in gas-fired rotary engines is, for example, the product sold under the trademark AIIFFER5DL-1. It contains 88% formulation of the reaction products of trimethylolpropane and various C7 to C18 carboxylic acids. This, however, creates wear and deposit problems in such engines.

British Patent Box 1,440.129 describes a lubricant containing 85-96% triisodecyl trimellitate as the main fluid. Tricresyl phosphate is used in the lubricant of Example 2. Inorganic metal-containing additives are also used in the two illustrated lubricants. The use of such metal-containing additives
When used under high temperature conditions above the decomposition temperature of the lubricant, such as temperatures in gas-fired rotary engines, undesirable ash residues will result. Such residues lead to wear, deposits and other problems. Furthermore, the lubricant shown in Example 2 of British Patent Box 1.44.0.129 contains triisodecyl trimellitate (85%) and tricresyl phosphate (1.5%), but also contains an alkyl methacrylate copolymer. Contains as a viscosity improver. The use of such copolymers in lubricants that are consumed with fuel in the engine combustion cycle will also result in undesirable carbon deposits. Accordingly, the lubricant compositions shown in British Patent Box 1,440,129 are used in gas-fired rotary engines in which the lubricant is sprayed into the combustion chamber for ultimate consumption along with the fuel. If so, it will result in residue problems (eg, ash deposition, or ash and carbon deposition).

SUMMARY OF THE INVENTION The lubricant compositions of the present invention provide improved lubricants for such engines, such as lubricants that are combusted with the fuel and leave essentially no residue within the combustion chamber. It is. This product is comprised of metal-free components and therefore does not produce ash when exposed to high temperature conditions above the decomposition temperature of the lubricant. It does not contain polymeric additives in its additive package that would also cause carbon deposits upon combustion.

The engine lubricant of the present invention is a formulation of an amount of at least one aromatic tricarboxylic acid triester, a small amount of a lubricant comprising a phosphate ester, and a substantially residue-free additive package.

The first component of the lubricants of the invention, which is present in a major or predominant amount and acts as the main component of the lubricating fluid, is at least one aromatic tricarboxylic acid triester. The ester component is a trimellitic acid ester component.These esters have the following formula:
Aromatic or benzenetricarboxylic triester.

AI'[:C(0)OR)3 (where A' is a phenyl ring and R is an aryl or alkyl group, e.g. having less than about 18 carbon atoms) Preferred alkyl groups in such esters has from about 4 to about 18 carbon atoms. This component is present in the lubricants of the present invention in an amount of from about 15 to about 99% by weight.

The table listed below lists the possible "R" groups (i.e., R', R" and R
This is a representative list of ``''').

・−・−to ・−person H jin q q sa・−・−to ・−＼ H mouth jin α mouth ＼・−・−(g)・−x
)-i q r\ α \ A preferred triester is triisodecyl trimellitate and tris-(2-ethylhexyl) trimellitate or a mixture thereof in a ratio that provides the desired viscosity.

Optional components of the invention, which may also be present in small amounts, e.g., up to about 1% by weight of the lubricant, include at least one thermally and oxidatively stable It is a phthalate ester component. This component is used to adjust the viscosity of the lubricant. This is because tricarboxylic triesters tend to be viscous and, if used without the additional inclusion of this optional phthalate, would not have the desired viscosity properties. Such a component is a benzene carboxylic acid diester of the formula:

Ar (C(0>0R)2 where Ar is a phenyl ring and R is an aryl or alkyl group having less than about 18 carbon atoms, e.g. from about 4 to about 10 carbon atoms, as defined above) The esters forming this component can be derivatives of benzene dicarboxylic acids such as phthalic acid, isophthalic acid and terephthalic acid. Phthalic esters in which the substituent is in the ortho position are , thermally and oxidatively unstable.

Both tricarboxylic triesters and phthalate esters of the type described above must be substantially completely esterified so that no unreacted acid functionality is found in the ester component.

Preferably, both are branched aliphatic esters of the benzene carboxylic acid type with suitable branched groups including 2-ethylhexyl, 2-ethylbutyl, isooctyl, isopropyl and isodecyl. U.S. Patent No. 2.7
As described in No. 60.934, 'oxo'°
Branched groups derived from alcohols are also useful.

The second component of the present invention is about 0.5 to about 10 weight percent phosphate ester component. This component is present as an antifriction and extreme pressure additive. Preferably, the phosphoric ester contains three aryl groups in the form of aryl and/or alkaryl groups.

Examples of useful phosphate esters are tert-butylphenyl/phenyl phosphate, 5eC-butylphenyl/
phenyl phosphate, and isopropylphenyl/phenyl phosphate. These phosphoric acid esters may be prepared according to known alkylation and phosphorylation procedures, such as those described in US Reissue Patent No. 29,540. Mixed tert-butyl/phenyl phosphates (primarily di-(tert-butylphenyl) monophenyl phosphate and mono-(tert-butyl) phenyl diphenyl phosphate) are highly preferred because of their ready availability and thermal stability.

The second anti-friction component of the lubricant composition also includes an additional extreme pressure anti-friction agent. Preferred extreme pressure lubricants are oil-soluble organic sulfur compounds, especially sulfurized hydrocarbons of the desired molecular weight. These sulfur compounds may also contain other useful groups containing phosphorus atoms. A preferred class of organic sulfur compounds are sulfurized olefins prepared by the reaction of C3-C6 olefins or polyolefins derived therefrom with sulfur-containing compounds such as sulfur, sulfur chloride, and phosphorous pentasulfide. Such extreme pressure additives are commercially available and are often included in additive packages designed for gear lubricants. Such commercially available additives can be used directly in the present invention, provided they are free of metal-containing components.

The third essential component of the present invention is an essentially residue-free additive package that can contain the following types of ingredients:

11j1 mass] 2.0% by weight or less, preferably 0.1 to 1.0% by weight m/0.015 to 2.0% by weight, preferably o, io to 0.0% by weight
3% by weight Suke J 0.05-2.0% by weight, preferably 0.25-1.0
Weight% Metal immobile growth wound 0.002-0.50% by weight, preferably 0.01-o
, o4% by weight 汲-'[-katana0, not more than 20% by weight, preferably not more than 0.1% by weight, in accordance with the present invention, so that the lubricant produces essentially no residue when burned. , if ash residue is to be avoided, the ingredients used in the additive package should be
zeolite which is essentially free of metallic groups or components.
There is a point. In other words, they are organic rather than metal-organic or inorganic. Also, the organic additive chosen should not be a polymer that produces carbon deposits when incinerated. With these conditions in mind, typical additives are described in British Patent Nos.
440,129, page 3, line 35 et seq., as additives, metal-free and non-polymerized organic PfIJ whistles can be selected.

The additive package used in this lubricant provides stability against oxidation, increases load characteristics, prevents corrosion from chemical attack on ferrous surfaces, and passivates non-ferrous metals such as copper-containing alloys. is intended.

Useful loading additives include amine salts of phosphoric and phosphonic acid derivatives. Furthermore, certain phosphorus amine compounds also function as non-ashing lubricants in the synthetic base of the present invention. Such phosphorus amine products would also provide rust protection. Lubricant compositions containing the optional extreme pressure lubricant do not require the addition of loading additives.

When the present lubricating composition is used in its preferred embodiment in a natural gas-fired rotary engine, there will be essentially no need to use detergent and dispersant type additives. This is because the lubricant in this type of rotary engine is not circulated and is consumed along with the fuel. Similarly, there is no need to add viscosity index improvers to these lubricants.

In particular, the type of polymeric viscosity improvers used in GB Patent Section 1.440.129 should be avoided.

Aromatic amines have been used for many years to improve the oxidative stability of various synthetic lubricant bases. For polyol esters of the type used in aircraft gas turbine engines, aromatic amines such as octylphenylnaphthylamine, fetchazene, and phenyl-alpha-naphthylamine are used to increase the oxidative stability of such fluids. There is a long history of

Phosphate triaryl esters are good anti-friction additives under normal loading conditions in both mineral oil-based and synthetic lubricants. For example, tert-butylphenyl/diphenyl phosphate also has additional properties that provide extreme pressure protection even under more severe loading conditions.

The following examples illustrate some preferred embodiments of the invention.

EXAMPLES Example 1 A lubricant composition according to the invention is made from a blend of the following ingredients.

Ingredients Trimellitic Acid Mixed Trialkyl Lubricant 1 (Trademark: HATCOL 2920) Trimellitic Acid Mixed Trialkyl Lubricant 2 (Trademark: HATCOL 2932) Diisophthalate (2% by weight 43,79 43,79 Ethylhexyl) Plasticizer ( Trademark: FLEXOL 380) 39.73 Tert-Butylphenyl/Diphenyl Phosphate (Trademark: 5YN-0-A[) 847B) 4 Phosphorus-Sulfur Extreme Pressure Reducing Composition (Trademark: HITECE-320) Alkylthiodi as a corrosion inhibitor Azole (trademark: AHOCO153) 1.0 1.0 0.15 Phenyl-α-naphthylamine as antioxidant 0.50 Benzotriazole as metal passivator 0.021 This product is 4568 US (Saybolt Universal Second: 5aybo+tunivers)
al 5eCOndS) (98mm2/s) (
7) It has viscosity.

2 This product is 69O8 at 100”F (37.8℃)
It has a viscosity of US (149 mm2/s).

3 Alternatives used include 5tauHer Ba5
eStock 610 or) Iorflex 112
1 is mentioned.

4 This product is 15O3 at 100”F (37.8℃)
It is a lubricant of U5 (32 strokes 2/s).

The resulting composition has a 0.6% oily odor.
It was a yellowish brown liquid with an acid value of 8 KOH/g.

The boiling point of this substance is over 600"F (315°C), the specific gravity is 0.98 at 60"F (15.6°C), and the flash point is 460°F.
(240℃) or higher, and the vapor pressure is 1 at 25℃,
It was less than 0 mmHg.

All of the above components are metal-free, thus making the overall composition an ash-free high temperature lubricant.

Example 2 Ingredients Weight % Trialkyl trimellitate lubricant 587/58 Dioctyl terephthalate plasticizer 9.13 tert
-Butylphenyl/Diphenyl Phosphate 1.0 (Trademark: 5YN-0-An 8478) Phosphorus-Sulfur Extreme Pressure Antifriction Composition (Trademark: Formerly TECE-320) 1.0 Alkylthiodiazole Preservative (Trademark = ^MOCO153) 0.15 phenyl-α-naphthylamine antioxidant 0°50 benzosoriazole metal passivator 0°025 Viscosity is 1
At 00'F (,37,8°C) m=n2/s>.

Example 3 Ingredients Trimellitic acid mixed trialkyl lubricant 6 Trimellitic acid mixed trialkyl lubricant Di(2-ethylhexyl diisophthalate) plasticizer (trademark: FLEXOL 380) tert-butylphenyl/diphenyl phosphate (trademark: 5YN-0) -AD 8478) Phosphorus-sulfur extreme pressure anti-friction composition (trademark: l1ECE-320) Alkylthiodiazole preservative (trademark: A) IOcO153) Phenyl-α-naphthylamine antioxidant 780S US (170% by weight 64.82 22,27 1.0 1.0 0.15 0.50 Benzotriazole metal passivator 0.026100
The viscosity at °F (37,8 °C) is 4563 U S (98
=2/s>.

Viscosity at 7100°F (37,8°C) is 11223U
S (242mm2/s >.

Example 4 Ingredients Weight % Trimellitic acid mixed trialkyl lubricant 898.33 tert-butylphenyl diphenyl phosphate 1. OO (Trademark: 5YN-0-8D 8478) Phosphorus-Amine Loading Additive (Trademark: VANLUBE 672) 0.
15 Phenyl-α-naphthylamine 0.50 Benzotriazole 0.028 This is 69O3U S (14
It had a viscosity of 9 mm2/s).

Example 5 Ingredients Weight % Trimellitic acid mixed trialkyl lubricant 944.16 Trimellitic acid mixed trialkyl lubricant 1044.16 Di(2-ethylhexyl) isophthalate 9.81 (Trademark:
FLEXOL 380) tert~butylphenyl diphenyl phosphate 1. OO (Trademark: 5
YN-0-AD 8478) Phosphorus-amine loading additive (commercial product: VANLUBE 672)
O-2゜Alkylthiodiazole corrosion inhibitor (trademark: A)tOco 153) 0.
15 Phenyl-α-naphthylamine antioxidant 0°50 Benzotriazole metal passivator 0.029 This one is 100
458S IJ S (98mm
2/s).

10 This thing is 18 at 100'F (37,8°C)
US (242mm”/s) (1) Has viscosity.

Example 6 Ingredients Weight % Trimellitic acid mixed trialkyl lubricant 1197°23 tert-butylphenyl diphenyl phosphate lubricant 1.00 (trademark: 5
YN-0-AD 8478) Phosphorus-amine loaded additive
0610 Phosphorus-sulfur extreme pressure anti-friction additive (trademark: HITECE-320) '・0
0 Alkylthiodiazol corrosion inhibitor (trademark: AHOCO153) 0.15 Phenyl-α-naphthylamine antioxidant 0.50 Benzotriazole metal passivator 0.0411 This one is 1
At 00'F (37,8℃) (148,6wan2/
! It has a viscosity of 9).

88SUS Example 7 Ingredients Weight % Trimellitic acid mixed trialkyl lubricant Di(2-ethylhexyl isophthalate) (Trademark: FLEXOL 380) tert-Butylphenyl diphenyl phosphate (Trademark: 5YN-[)-AI) 8479) Phosphorus- Sulfur Extreme Pressure Antifriction Compound (Trademark: RO3CAN 480) Alkylthiodiazole Corrosion Inhibitor (Trademark: AHOCO153) Benzotriazole 0.50 0.15 6.00 0,02 88.00 Table ■ As shown in the previous examples The viscosity properties of various lubricants containing trimellitic acid esters are summarized in the table below.

Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Viscosity, SUS (-2/5) 128, 7) 125.4 104.8 139.7 127.8 145.7 131 .0 63.5 59.4 68.4 64.0 G8,1 63.7 11.45) 11.32) 10,0) 12.5) 11.33) 12.55) 11,37) Table ■ Lubricity test conditions of synthetic lubricant mainly composed of trialkyl trimellitate measured by four-ball wear test: load 4 hg, speed 1200 rpm, temperature 60°C, time 1.0 hour Fluid trialkyl trimellitate Example 1 Implementation Example 2 Example 3 Example 4 Trialkyl trimellitate (90% by weight) +FLEXOL 380 (trademark) (1
0% by weight) Example 5 Example 6 Example 7 STAUFER5DL-1 Lubricant wear flaw (mm) 0.83 0.35 0.34 0.35 0.36 0.87 0.36 0.33 0. 39 0.38 The above examples, while illustrating certain preferred embodiments of the invention, are not to be construed in a limiting sense.

Out wish Man Akzo・ naam rose Fennote Jatsubu

Claims (1)

[Claims] 1. A predominant amount of at least one aromatic tricarboxylic acid triester, a minor amount of an anti-friction agent comprising a phosphate ester, and essentially free of metallic groups or components, and an engine additive. An engine lubricated composition containing a small amount of organic additive package that leaves substantially no residue in the engine when the lubricant is burned off during operation. 2. Tricarboxylic acid triester is 1% by weight of lubricant.
The composition according to claim 1, containing from 5 to 99% by weight. 3. The composition according to claim 1 or 2, wherein the tricarboxylic acid triester is a trimellitic acid ester having an alkyl group of 4 to 18 carbon atoms. 4. The composition according to any one of claims 1 to 3, wherein the lubricant is contained in an amount of 0.5 to 10% by weight based on the weight of the lubricant. 5. The composition according to any one of claims 1 to 4, wherein the phosphoric acid ester contains three aryl groups. 6. A composition according to any one of claims 1 to 5, wherein the lubricant further comprises an additional extreme pressure lubricant. 7. The composition according to any one of claims 1 to 6, wherein the extreme pressure lubricant is contained in an amount of 0.25 to 5.0% by weight based on the weight of the lubricant. 8. The composition according to claim 6 or 7, wherein the extreme pressure lubricant is a sulfurized synthetic product. 9.Organic additive package is 0.1 to lubricant weight
9. A composition according to any one of claims 1 to 8, comprising 5% by weight. 10.Organic additive package is 2% by weight of lubricant.
．． Load additives up to 0% by weight; Corrosion inhibitors from 0.015 to 2.0% by weight; Antioxidants from 0.05 to 20% by weight; Metal passivators from 0.002 to 0.50% by weight. , and 0
．． 10. A composition according to any one of claims 1 to 9, comprising up to 20% by weight of wetting agent. 11. The composition according to any one of claims 1 to 10, further comprising a small amount of thermally and oxidatively stable phthalate ester. 12. Phthalate ester is 15% by weight based on the weight of the lubricant.
12. The composition according to claim 11, comprising: 13. The composition according to claim 11 or 12, wherein the phthalate is selected from the group consisting of isophthalate and terephthalate. 14. For lubricating a high-temperature rotary engine by supplying engine lubricant together with fuel into the combustion chamber of the engine and consuming the lubricant during operation of the engine, the method according to any one of claims 1 to 13 A method using the engine lubricant composition described in .