JP2002500261A - Rust preventing turbine oil containing monobasic amine phosphate salt and dicarboxylic acid - Google Patents

Abstract

(57) [Summary] By adding a small amount of monobasic amine phosphate salts and dicarboxylic acids to a turbine oil base oil, a turbine oil having improved rust prevention properties is provided. The use of the listed combinations results in unexpectedly good rust resistance compared to the use of the individual components. Turbine oils that benefit from additives are preferably oils based on polyol esters.

Description

DETAILED DESCRIPTION OF THE INVENTION

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to turbine oils based on polyol esters, which exhibit rust prevention by the use of additives. More specifically, the present invention relates to a turbine oil containing an ester of pentaerythritol and a fatty acid as a base oil and containing a combination of additives for imparting rust prevention.

2. Description of the Prior Art Corrosion and rust are extremely detrimental conditions for high performance, high precision gas turbine engines. Corrosion and rust are particularly detrimental to engines operated under severe stress, atmospheric, duration and operating conditions. Natural effects, chemicals, large temperature changes,
Exposure to water and corrosive water environments places a strain on the engine, impacts reliability, reduces the time between repairs, and increases the opportunity for major overhauls and replacement of critical components.

[0003] The fundamental weapon in combating corrosion and rust in gas turbine engines is lubricating oil that is as sophisticated as the engine itself. To protect the engine from water, corrosion, rust and other harmful effects of oxidizing atmospheres, harsh temperatures and generally harsh conditions, turbine oils, complex formulations based on synthetic base oils, have been developed. ing.

[0004] US Pat. No. 4,320,018 relates to synthetic turbine oils based on aliphatic ester systems containing phenylnaphthylamine, dialkyldiphenylamine, polyhydroxyanthraquinone, hydrocarbyl phosphates and dialkyl disulfide compounds. This oil is described as useful over a wide range of temperatures and exhibits thermal and oxidative stability.

[0005] WO 94/10270 discloses synthetic ester base stocks, at least one aromatic amine antioxidant, neutral organophosphates, saturated or unsaturated dicarboxylic acids, optionally sulfurized linear or Corrosion inhibiting lubricating oil compositions comprising a branched or saturated monocarboxylic acid or an ester of such an acid, and a triazole compound. Such a formulation is compatible with XAS-L-572 for corrosion protection.
4 (MIL-L-23699E) of the United States Navy's Military S
It is described as meeting the latest version of the specification MIL-L-23699D.

Other references teaching turbine oils based on synthetic esters containing various combinations of additives include US Pat. No. 4,226,732, US Pat. No. 4,216,100, U.S. Pat. No. 4,189,388, U.S. Pat.
No. 188,298, U.S. Pat. No. 4,179,386, U.S. Pat.
No. 971, U.S. Pat. No. 4,157,970, U.S. Pat. No. 4,141,845, U.S. Pat. No. 4,141,844, U.S. Pat. No. 4,124,514, U.S. Pat. No. 513, U.S. Pat. No. 4,119,551, U.S. Pat.
No. 096,078, U.S. Pat. No. 4,064,059, U.S. Pat.
No. 721, U.S. Pat. No. 4,049,563. The improved synthetic ester base stock itself is described and claimed in US Pat. No. 4,826,633.

SUMMARY OF THE INVENTION [0007] The present invention relates to turbine oil compositions that exhibit high resistance to rust and corrosion, and to methods of achieving turbine oil.

[0008] The gas turbine lubricating oil of the present invention comprises a main portion of a base oil mainly composed of a synthetic polyol ester and a sub-portion of a rust / corrosion prevention additive containing an amine phosphate salt and a dicarboxylic acid. Including. Other extreme pressure agents, pour point depressants, antioxidants, defoamers, viscosity index improvers, antiwear agents, hydrolysis stabilizers, corrosion inhibitors and other conventional additives may be used.

Lubricating oil additives are commonly referred to as “Lubri by Dieter Klamann.
cans and Related Products ", Verlag
Chemie, Deerfield Beach, Florida, 198.
4.

[0010] Such improved rust / corrosion protection performance in turbine lubricating oils is attributed to additive packages containing mixtures of amine phosphate salts and dicarboxylic acids in lubricating oils based on synthetic polyol esters. It is realized by adding.

The amine phosphate salt is used in an amount ranging from 25 to 500 ppm, preferably 50 to 250 ppm, most preferably 75 to 150 ppm, and the dicarboxylic acid is
~ 1000 ppm, preferably 50-400 ppm, most preferably 75-20
0 ppm and the combination of amine phosphate salt and dicarboxylic acid is 5 ppm
0-1500 ppm, preferably 100-400 ppm, most preferably 100
Used in total amounts in the range of ~ 300 ppm.

The use of the amine phosphate-dicarboxylic acid additive mixture provides the expected performance compared to the performance exhibited when each additive component is used alone, and simply by combining the individual contributions of each component. As a result, a turbine oil is produced which exhibits remarkably excellent rust prevention and corrosion prevention performance.

DETAILED DESCRIPTION A turbine lubricating oil having unexpectedly superior rust and corrosion inhibiting performance, comprising a major portion which is a synthetic polyol ester base oil, essentially a monobasic amine phosphate salt and a dicarboxylic acid. And a sub-part that is a rust-prevention additive package consisting of a mixture of the following.

[0014] Synthetic polyol ester base oils are formed by the esterification of an aliphatic polyol with a carboxylic acid. The aliphatic polyol reactant contains from 4 to 15 carbon atoms and has from 2 to 8 esterifiable hydroxyl groups. Examples of polyols are trimethylolpropane, pentaerythritol, dipentaerythritol, neopentyl glycol, tripentaerythritol and mixtures thereof.

[0015] The carboxylic reactant used to produce the synthetic polyol ester base oil is selected from aliphatic monocarboxylic acids or mixtures of aliphatic monocarboxylic acids and aliphatic dicarboxylic acids. The carboxylic acids contain 4 to 12 carbon atoms, include straight and branched chain aliphatic acids, and mixtures of monocarboxylic acids may be used.

Preferred polyol ester base oil, technical pentaerythritol and _C 4 ~
It is those prepared from a mixture of C ₁₂ carboxylic acid. Industrial pentaerythritol is a mixture containing about 85-92% monopentaerythritol and 8-15% dipentaerythritol. Typical industrial pentaerythritol has the formula

[0017]

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About 88% of monopentaerythritol having the formula

[0019]

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Contains about 12% of dipentaerythritol having the formula: The technical pentaerythritol may contain some tripentaerythritol and tetrapentaerythritol, which are usually produced as by-products during the production of technical pentaerythritol.

The preparation of esters from alcohols and carboxylic acids is carried out using conventional methods and techniques well known to those skilled in the art. Generally, technical pentaerythritol is heated with the desired carboxylic acid mixture, optionally in the presence of a catalyst. Generally, a slight excess of acid is used to complete the reaction. Water is removed during the reaction, and then excess acid is removed from the reaction mixture. The esters of industrial pentaerythritol may be used without further purification or may be further purified using conventional techniques such as distillation.

As used herein and in the claims, the term “technical pentaerythritol ester” is understood to mean a polyester base oil prepared from technical pentaerythritol and a mixture of C ₄ -C ₁₂ carboxylic acids. You.

As mentioned above, a secondary portion, which is an additive mixture comprising one or more amine phosphate salts and one or more dicarboxylic acids, is added to the polyol ester base stock.

The monobasic amine phosphate salt (s) used are monobasic hydrocarbylamine salts of acidic phosphoric esters, preferably of the formula:

[0025]

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Wherein R and R ′ may be the same or different, and₂~ C₂₄Straight chain
Alkyl or branched alkyl;₁Is H or C₄~ C₂₀A straight-chain alkyl or branched-chain alkyl,
Or R₄And R₅May be the same or different and H or C₁~ C ₁₆ R which is alkyl₄-Aryl-R₅And R₂Is C₄~ C₂₀A linear or branched alkyl of the formula₄Passing
And R₅May be the same or different and H or C₁~ C₁₆With alkyl
Some R₄-Aryl-R₅And R₃Is C₄~ C₂₀A linear or branched alkyl, or R₄Passing
And R₅May be the same or different and H or C₁~ C₁₆With alkyl
Some R₄-Aryl-R₅).

Preferred monobasic amine phosphate salts are those wherein R is a straight or branched chain C ₆ -C ₁₆ alkyl.

The monobasic amine phosphate salt is 25 to 25% (based on the polyol ester base oil).
500 ppm, preferably 50-250 ppm, most preferably 75-150 p
Used in amounts in the pm range.

The dicarboxylic acid is a dicarboxylic acid having a total number of C _{10 to} C ₄₀ carbon atoms, or a mixture thereof, preferably a C _{24 to} C ₄₀ dicarboxylic acid, or a mixture thereof, most preferably a C ₃₆ dicarboxylic acid, or It is a mixture. The dicarboxylic acids can be any n-alkyl, branched alkyl, aryl, having a total number of carbons within the above ranges,
Alternatively, it may be an alkyl-substituted aryldicarboxylic acid or a mixture thereof.
Preferred dicarboxylic acids are selected from the group consisting of commercially available dioleic acid, sebacic acid, azelaic acid and mixtures thereof, known as "dibasic acids".

The dicarboxylic acid is 25 to 1000 p based on the polyol ester base oil.
pm, preferably between 50 and 400 ppm, most preferably between 75 and 200 ppm.

The mixture of amine phosphate salt and dicarboxylic acid is used in an amount ranging from 50 to 1500 ppm (based on polyol ester base stock), preferably 100 to 400 ppm, most preferably 100 to 300 ppm. .

The amine phosphate salts and dicarboxylic acids are 5: 1 to 1: 5, preferably 2: 1.
Used in ratios ranging from 1: 2.

The synthetic polyol ester-rust additive-containing turbine oil may also comprise one or more of the following classes of additives: antioxidants, antiwear agents, extreme pressure additives,
Defoamers, detergents, hydrolysis stabilizers and metal deactivators. The total amount of such other additives may range from 0.5 to 15% by weight, preferably from 2 to 10% by weight.
, Most preferably in the range of 3 to 8% by weight.

Antioxidants that can be used include arylamines such as phenylnaphthylamines and dialkyldiphenylamines and mixtures thereof, hindered phenols, phenothiazines, and derivatives thereof.

[0035] Antioxidants are generally used in amounts ranging from 1 to 5% by weight.

As antiwear / extreme pressure agents, hydrocarbyl phosphate esters, in particular,
Examples include trihydrocarbyl phosphate esters in which the hydrocarbyl group is an aryl group or an alkaryl group, or a mixture thereof. Specific antiwear / extreme pressure agents include tricresyl phosphate, triaryl phosphate and mixtures thereof. Other or additional antiwear / extreme pressure agents can also be used.

In general, the antiwear / extreme pressure agent is used in an amount ranging from 0 to 4% by weight, preferably 1 to 3% by weight.

[0038] Corrosion inhibitors known in the art may also be included in the turbine oil. Such known corrosion inhibitors include various triazoles.

For example, tolyltriazole, 1,2,4-benzotriazole, 1,2,2
3, benzotriazole, carboxybenzotriazole, alkylated benzotriazole and the like.

Known corrosion inhibitors include 0.02 to 0.5% by weight, preferably 0.05 to 0.2%.
It can be used in amounts ranging from 5% by weight.

As mentioned above, other additives can be used, including hydrolysis stabilizers, pour point depressants, defoamers, viscosity improvers, viscosity index improvers, and the like.

The turbine oil of the present invention meets the requirements set forth by the United States Navy in MIL-L-23699E for corrosion control type 5cSt turbine oil,
Transcend this requirement. A fully blended turbine oil based on a polyol ester to which the rust / corrosion inhibitor of the present invention comprising a mixture of an amine phosphate salt (s) and a dicarboxylic acid (s) is added is MIL-L-23699E. Pass the ball corrosion performance test (75% = pass test).

The present invention is further described by reference to the following non-limiting examples.

EXPERIMENTAL EXAMPLES Example 1 In the following examples, a series of fully formulated aviation turbine oils meeting all the specifications of MIL-L-23699 were used. The polyol ester base oil prepared by the reaction of a mixture of pentaerythritol and _C 5 _{-C 1 0} acid, 1.7
Contains 2.5% by weight arylamine antioxidant, 1.5-2% triaryl phosphate, 0.1% benzotriazole or alkyl-benzotriazole, and 0-0.04% ditridecylamine. Used with standard additive package. To this was added various corrosion protective package consisting of: 1) Phosphate only: The alkyl substituents of the phosphate is primarily ethylhexyl or octyl C ₆ -C ₁₆ the length of the chain Monobasic amine phosphate salt containing several (
Ortholeum 535) 2) Only dicarboxylic acid: industrial dimerized oleic acid or sebacic acid. Dimerized oleic acid contains many specific chemicals that contain cyclic and aromatic structures and have small amounts (<3%) of non-dimerized acids and small amounts of 2-10% of trimerized acids. 3) Combination (invention): a combination of the two materials described in (1) and (2) above.

These oils were tested in the MIL-L-23699E standard ball corrosion performance test for rust prevention performance. This test simulates the ability of oil to prevent corrosion of stainless steel balls due to the action of seawater, and MIL-L
All are described in the -23699E standard. In general, but not always, 10 balls were used in each experiment with the test oil, 4 balls were used to test the failed reference oil, and 4 balls were used to test the passing reference oil. use. At the end of the test, the test oil showed that at least 75% of the balls had no rust pits, the passing reference oil also showed at least 75% of the passing balls (at least 3 or 4), and the failing reference oil was 75% Less than passing balls (at most 2 out of 4
) Indicates that the ball corrosion test was passed.

A series of test results for the three concentration ranges are shown in FIG. In all cases, the concentrations refer to the total corrosion inhibitor concentration used. For combinations, ratios between 1 part phosphate to 2 parts dicarboxylic acid to 2 parts phosphate to 1 part dicarboxylic acid were used.

FIG. 1 shows the total percentage of balls that passed all the experiments for the three corrosion inhibitor systems over the indicated concentration range. In all three cases, there was no statistically significant trend at the 95% confidence level in the three ranges shown. Neither the phosphate component nor the dicarboxylic acid component used alone provides reliable rust protection and has a minimum of 7
Less than half of the tests passed the 5% specification. However, the combination of the two components used at the same total additive compounding ratio showed a synergistic effect, greatly increasing the possibility of passing results. The results are shown in Table 1 below.

[0048]

[Table 1]

From this table, it can be seen that consistent performance in ball corrosion tests was demonstrated only for the combination of both components across the range of turbine oil formulations. Concentrations that, when used alone, will cause other performance problems in turbine oils (excessive initial acid number and poor hydrolytic stability for dicarboxylic acids, excessive silicone seal degradation for phosphate amine salts). 300pp
Even when the concentration was increased to above m, a pass result was not always obtained from any of the components.

Example 2 In this example, a series of turbine oils similar to those in Example 1 were used, with the following differences. Here, the use of mixed monobasic and dibasic amine phosphates as corrosion inhibitors was investigated. The amine phosphate salts used are mixed methyl monobasic and dibasic phosphoric acids and butyl monobasic and dibasic phosphoric acids, the industrial products Vanlube-692 and Van
lube-672. Vanlube-692 is primarily butyl, with Vanlube-672 having more methyl groups.

These materials were used at 100-200 ppm with 150 ppm of technical dioleic acid Empol 1022. In two experiments, 12 of the 27 balls passed (44%), and one of the two tests had at least 75% of the passing balls (50% test passed).

In a second set of experiments, 150 ppm of an industrial amine phosphate salt, Ortholeum
To a formulation containing 535 and 150 ppm of industrial dioleic acid Empol 1022, 100 ppm of Vanlube-692 was added. From FIG. 1, V
It can be seen that in the absence of anlube-692, 85% of the balls using a combination of monobasic phosphoric acid and dicarboxylic acid at a total of 300 ppm are expected to pass, and from Table 1 it can be seen that this combination shows that It turns out that it passes 84%. However, four times at the U.S. Navy Labs where the mixed monobasic and dibasic amine phosphate salts were added to the formulation containing the monobasic amine phosphate salts, four out of fifty balls Only 15 (30%) passed and none of the tests resulted in a 50% passing ball (0 out of 4).

The use of monobasic phosphoric acid is not possible because dibasic amine phosphate salts are not effective in combination with dicarboxylic acids and reduce the performance of monobasic amine salt-dicarboxylic acid synergistic combinations. The necessity can be seen from this embodiment.

[Brief description of the drawings]

FIG. 1 shows the MIL-L-2 of a turbine oil containing amine phosphate salts and dicarboxylic acids, alone and in combination, in three different total additive concentration ranges.
It is a figure which shows comparison of 3699E ball corrosion test performance. In all cases, the combinations exceeded expectations from the combined individual performance of each component, as well as the individual contribution of each component.

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Belltour, Morton Norman Place, 724, Westfield, New Jersey 07090 United States of America 724 (72) Inventor Ashcraft, Thomas El. Junior. Booth Circle 15771, Leander, Texas, USA 78641 (72) Inventors Berlovitz, Paul Jay. United States, New Jersey 08520, East Windsaw, Jamestown Road 939 F-term (reference) 4H013 CH02

Claims (7)

[Claims] Claims: 1. Addition of a secondary part additive containing a mixture of an amine phosphate salt and a dicarboxylic acid to turbine oil to enhance the resistance of turbine oil based on synthetic polyol esters to rust and corrosion. Wherein the dicarboxylic acid is a C ₉ -C ₄₀ total carbon number dicarboxylic acid or a mixture thereof,
The phosphate amine salt is composed of a monobasic phosphate amine salt, and the dicarboxylic acid is
The amine phosphate salt is present in an amount in the range of 25-1000 ppm;
0 ppm and the ratio of amine phosphate to dicarboxylic acid is 5 ppm.
: A method ranging from 1 to 1: 5. 2. The base oil containing the synthetic polyol ester as a main component is from 4 to
Claims 1. An esterification product of an aliphatic polyol containing 4 to 15 carbon atoms and 2 to 8 esterifiable hydroxyl groups which has been reacted with a carboxylic acid containing 12 carbon atoms. Item 1. The method according to Item 1. 3. The base oil comprising a polyol ester as a main component is an esterification product of industrial pentaerythritol and a mixture of C _{4 to} C ₁₂ carboxylic acids. the method of. 4. The method according to claim 1, wherein the amine phosphate is a monobasic hydrocarbylamine salt of an acid phosphate. 5. The amine phosphate salt of the formula:(Wherein R and R ′ may be the same or different and₂~ C₂₄Directly
A chain alkyl or branched alkyl;₁Is H or C₄~ C₂₀Directly
Chain alkyl or branched alkyl, or R₄And R₅Are the same but different
May be H and C₁~ C₁₆R which is alkyl₄-Aryl-R₅ And R₂And R₃Is C₄~ C₂₀Linear or branched alkyl of
Or R₄And R₅May be the same or different and H or C₁~ C ₁₆ R which is alkyl₄-Aryl-R₅The method according to claim 4, characterized in that: 6. The method according to claim 5, wherein R is a linear or branched C ₆ -C ₁₆ alkyl. 7. The method according to claim 4, wherein the dicarboxylic acid is dioleic acid, sebacic acid, azelaic acid and a mixture thereof.