JPS6043396B2 - Water-based energy transfer fluid compositions - Google Patents

Abstract

Aqueous composition having a viscosity of at least 10.10<-><6> m<2>/s centistokes at 40 DEG C which contain up to about 80 percent by weight of water, at least 0.1 percent by weight of an acidic lubricity agent and an effective amount of an anti-wear additive which is the combination of a nitroaromatic compound component and a hydroxyl substituted aromatic acid component exhibit enhanced anti-wear and lubricity properties.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to fluid compositions particularly useful for transferring energy in mechanical systems, and more particularly! relates to water-based compositions that have enhanced lubricity and anti-wear properties and are useful for transmitting hydraulic energy.

Water-based working fluids are well known and have been used industrially for many years, particularly in applications where fire resistance is desired. See, for example, U.S. Pat. No. 2,602,780 to Zlsman et al. and Rangel (
Lan? One of the commonly used classes of water-based fluids mentioned above, such as disclosed in U.S. Pat. No. 2,768,141 to R) et al. of a glycol or glycol ether and a high molecular weight polymeric thickener, such as a water-soluble poly(alkylene oxide) polymer, for viscosity control. Such compositions also contain various additives added to hydraulic systems and to enhance the lubrication, corrosion protection and other performance properties necessary for lubricants. do.

Water-based working fluids are typically highly nonflammable,
Although they have good temperature stability and relatively low cost, they generally have inferior anti-wear properties than petroleum-based fluids. The fluids used in the energy transfer system are ■
They must have sufficient lubricity and mechanical stability so that they can be used in self-lubricating pumps and valves, etc. used in commercial hydraulic systems.
Good lubricity, especially good slipperiness and oil film strength, for reducing wear on moving elements of hydraulic systems where the gaps between friction surfaces are very small and the pressures can be very high. is particularly important. Traditionally, to improve the lubricity and/or poor anti-wear properties of these fluids, for example, modification of poly(alkylene oxide) polymers, which are commonly added as viscosity modifiers; conventional oil improvers (0i11mpr0ver), extreme pressure agent (E.P.a?N
t), incorporating additives such as corrosion inhibitors and sequestering agents; and as disclosed in US Pat. No. 3,992,312 to Genjida et al. Various attempts have been made including the incorporation of certain water soluble additives such as oxyalkylene adducts of polyamides. However, none of these methods has been found to be completely effective, especially when anti-wear properties are desired under high pressure conditions; Therefore, there is a strong desire to develop a water-based fluid that meets these requirements. Additionally, for industrial applications, it would also be desirable to provide energy transfer fluids that contain more than 50% water, a value that is generally limited to known fluids such as those described above. The present invention provides a water-based energy-transferring and lubricating fluid with increased wear protection. The fluid includes an aqueous composition having a viscosity of at least about 10 centistokes at 40°C and containing up to about 8% water, and at least 0.1% by weight of an acidic lubricant and the aqueous composition. An antiwear additive is incorporated into the composition in an amount effective to increase the antiwear properties of the composition, the antiwear additive comprising a hydroxyl-substituted aromatic acid component and a nitroaromatic component. Consists of a combination of The compositions of the present invention also contain from 0 to about (4)% by weight of water-soluble glycols or glycol ethers having from 2 to about 14 carbon atoms to be used as freezing point depressants.
and about 5 to about 5 weight percent of a water-soluble polymeric viscosity modifier. The present invention also provides a method for increasing the anti-wear properties of a water-based energy transfer fluid containing an acidic lubricant.

The method comprises applying an antiwear additive comprising a combination of a hydroxyl-substituted aromatic carboxylic acid component and a nitro-substituted mononuclear aromatic component in an amount effective to increase the antiwear properties of the fluid composition. , including incorporating the water into a water-based energy transfer fluid. The inventors have demonstrated that the particular combination of antiwear additive components disclosed herein improves the antiwear and lubricity properties of water-based energy transfer compositions, including also conventional acidic lubricants. 8% by volume, which in combination is effective to increase the amount of water that can be used in water-based compositions conventionally employed as energy transfer fluids. It has now been discovered that it is possible to produce compositions such as those described above that contain large amounts of water.

According to the present invention, the water-based energy transfer fluid contains up to 8% water, a conventional acidic lubricant, and a hydroxyl-substituted aromatic carboxylic acid component and a nitro-substituted monomer. An aqueous composition having a viscosity of at least 10 centistokes at 40'C with added antiwear and lubricity additives in combination with a nuclear aromatic component.

Acidic lubricants suitable for use in the compositions of the present invention are well-known materials commonly used as lubricity enhancers in water-based working fluids and similar fluids. Such suitable acidic substances include, for example, fuluric acid, fuluric acid, pelargonic acid, fulric acid, lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, undecanoic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, maleic acid, fumaric acid,
Saturated and unsaturated aliphatic carboxylic acids such as glutaconic acid, butenetricarboxylic acid and at least 6 carbon atoms
Aromatic carboxylic acids such as benzoic acid, dimethylbenzoic acid, phthalic acid, terephthalic acid, isophthalic acid and trimellitic acid; alkali metal salts of said aliphatic carboxylic acids and aromatized carboxylic acids; −
These include organic amine salts such as morpholine; polymerized fatty acids (dimer acids); oxycarboxylic acids such as malic acid and alcoholic acid; and lect(1ect0)-dicarboxylic acids such as acetone dicarboxylic acid. In principle, the acidic lubricant may be present in an amount between about 0.1% and 10% by weight of the water-based composition, inertly about 0.5% by weight. and 2% by weight, although higher amounts of the acidic lubricant can be used if desired for a particular application.

The essential components of the composition of the present invention are four anti-wear additives which are a combination of a hydroxyl-substituted aromatic carboxylic acid component and a nitro-substituted mononuclear aromatic compound component.

Nitro-substituted mononuclear aromatic compounds suitable for use as antiwear additive components in the compositions of the present invention are mononuclear aromatic compounds having at least one substituted nitro group.

Suitable nitroaromatic compounds as described above are compounds such as nitro-substituted aromatic acids and nitroaromatic salts and esters which provide in situ generation of acid anions. Representative examples of suitable nitro-substituted mononuclear aromatic compounds include 3-nitrobenzoic acid, 4-nitrophthalic acid, 4-nitrobenzoic acid, and 4-nitrobenzoic acid.
-Nitroisophthalic acid, 3,5-dinitrobenzoic acid, p
- nitrocinnamic acids etc. and their alkali metal salts,
Hydroxyl-substituted aromatic carboxylic acids suitable for use in combination with the nitro-substituted mononuclear aromatic compounds include mononuclear salts such as salicylic acid, dihydroxyl-substituted benzoic acid, etc. a nuclear hydroxyl-substituted aromatic acid and the general formula or It is a cross-linked dimer of a hydroxyl-substituted aromatic carboxylic acid having hydrogen atoms, hydroxyl groups, amino groups, alkyl groups, or sulfonyl groups, which may be the same or different.

Typical and suitable cross-linked dimer acids include 5,5'-methylenedisalicylic acid, pamonic acid
) and methylene- or sulfur-bridged, hydroxyl-substituted aromatic carboxylic acids such as thiodisalicylic acid.

The compound can be present in the composition as a salt, such as an alkali metal, amine or ammonium salt. In the compositions of the present invention, nitro-substituted mononuclear aromatic compounds and hydroxyl-substituted aromatic carboxylic acids are used to produce water-based compositions exhibiting increased anti-wear properties and lubricity. It is an essential requirement that both exist.

As a general rule, the combination of antiwear additive components described above:
Operating conditions and usability required for individual applications. should be present in a total amount sufficient to provide the desired degree of antiwear and lubricity to the composition. The amount of this combination of antiwear additive components to be present is referred to herein as an effective amount and is necessary to achieve the antiwear properties and lubricity required for a particular application. It is defined as the minimum amount. Although the amount of each antiwear additive component and the effective amount of combinations thereof will vary to some extent depending on the application, the amount of each additive component present per liter of aqueous composition should be at least about 0.0025 y-mol (generally about 0.0025 y-mol)
00 weight%), preferably about 0.01 to about 0.50
y-mol or even more (generally about 0.01
% by weight to about 1% by weight). The relative proportions and maximum amounts of each of the additive components and combinations thereof to be present are not critical, and economic factors will generally dictate the use of large excesses of the amounts practically required. be done. The water-based composition of the present invention has a
It should have a viscosity of at least 10 centistokes at °C and can contain up to about 8% water by volume.

Generally, the viscosity of the aqueous compositions of the present invention can vary depending on the energy transfer application for which the composition is intended and the temperature range in which the composition is used. For example, an energy transfer fluid such as a working fluid may have a
It can have a viscosity in the range of about 25 to 150 centistokes, preferably in the range of about 30 to 85 centistokes at °C, and lubricating fluids can be used with similar viscosity requirements. It is desirable to be able to provide an energy transfer fluid that contains the maximum amount of water to provide fire-resistant properties, but that is operable in existing equipment while still providing adequate boundary lubrication and lubrication to mechanical elements. It is also important to have a viscosity range that allows for Accordingly, the water content of the compositions of the present invention can vary over a range of from about 2% by weight to about 8% by weight, preferably from about 3% by weight to about 7% by weight. In order to achieve the viscosity range that may be desired for a particular application, and in which case the water content of the composition can vary over a wide range, generally A water-soluble polymeric viscosity modifier and/or thickener is added to about 50% of the composition.
It is used in amounts ranging from about 10 to 5% by weight, preferably from about 10 to 2% by weight.

Water-soluble polymers suitable for use as viscosity modifiers in the compositions of the present invention are poly(alkylene oxide) polymers. Such polymers are known compounds that are water-soluble despite having a high molecular weight. Generally, these polymers contain either oxyethylene groups or both oxyethylene groups and higher oxyalkylene groups, such as oxypropylene and oxybutylene groups, which are randomly distributed in the molecules of these polymers. or block distribution, and has an average molecular weight of 400
from about 40,000 or even more. The amount of oxyethylene groups in the molecule is such that the poly(alkylene oxide) polymer is soluble in water at room temperature, and the amount of oxypropylene groups or higher oxyalkylene groups is based on the average molecular weight. 4000
0 or above, the poly(alkylene oxide) remains liquid at room temperature, or about 60
The amount is such that it may melt at a temperature below 0.degree. The oxypropylene/oxyethylene ratio can vary from zero to about one. These poly(alkylene oxide) polymers may be ethylene oxide, or mixtures of ethylene oxide and propylene oxide or higher alkylene oxides, and may contain at least one active hydrogen atom up to six active hydrogen atoms. It can be produced by a method well known in the art by reacting a compound having the following. Said compounds include, for example, water; monohydric alcohols such as ethanol and propanol; dihydric alcohols such as ethylene glycol; trihydric alcohols such as glycerin and trimethylolpropane; tetrahydric alcohols such as pentaerythritol; sorbitol. hexahydric alcohols such as; and monofunctional or polyfunctional amines such as butylamine and ethylenediamine. The poly(alkylene oxide) product of the above reaction will have linear or branched oxyethylene chains or oxyalkylene chains higher than oxyethylene, and the chains will be hydroxyl terminated. Some or all of these hydroxyl groups can be etherified by reaction with a dialkyl sulfate such as diethyl sulfate. Another known class of water-soluble polymers suitable as thickeners or viscosity modifiers are the ethylene oxide/propylene oxide adducts of alkylphenols and the ethylene oxide/propylene oxide adducts of alkylphenols disclosed, for example, in U.S. Pat. No. 2,768,141 to Langer et al. Katsuenshiyutain (Kat)
U.S. Patent No. 3,379,644 for
Polymeric adducts of alkylphenols and alkylene oxides, such as ethoxylated dinonylphenols disclosed in the US Pat. For example, McC code (McC)
U.S. Pat. Alkyl methacrylates are also suitable as viscosity modifiers. Urethane polymers, such as those disclosed in US Pat. No. 3,352,783, are other water-soluble polymers suitable for use as viscosity modifiers. Other suitable water-soluble polymers include, for example, Shilbe
These include polyamide esters, such as those disclosed in U.S. Pat. No. 3,341,573 to Genjida et al., and polyamide alkoxylates, such as those disclosed in U.S. Pat.

According to the invention, a water-soluble freezing point depressant can also be included in a preferred embodiment of the composition of the invention.

The commonly used water-soluble freezing point depressants include ethylene glycol, diethylene glycol, triethylene glycol and their ethylene glycol ethers such as ethyl, methyl, propyl and butyl ethers;
2 to about 1 carbon atom, such as similar ethers of
These are glycols or glycol ethers having 4 glycols. It is generally preferred to use simple polyols typified by ethylene glycol, propylene glycol, butylene glycol, glycerin, and diethylene glycol. As a base for the energy transfer fluid of the present invention, the glycols or glycol ethers are used when they are combined with water to achieve the desired low temperature utility (
10wtemperatureservice11
ty). The energy transfer fluids of the present invention contain other ingredients commonly used in water-based fluids such as corrosion inhibitors, antioxidants, antifoaming agents, PH modifiers, dyes, sequestering agents, etc. You can also do that.

These range from about 0.01% to about 5 to 1% by weight of the composition.
It can be used in small amounts up to 0% by weight. Representative examples of the above substances that can be used are monoethanolamine, monoisopropanolamine, diethanolamine, triethanolamine, ethylenediamine, dimethylethanolamine, diethylenetriamine, cyclohexylamine, morpholine, 1,4-bis(2-aminoethylamine). ) Corrosion inhibitors including piperazine, 2-heptadecyl-1-(2-hydroxyethyl)imidazoline, derivatives such as their alkaline oxide adducts, alkali metal salts of carboxylic acids, etc.; PH regulators, including organic amines and alkali metal hydroxides; antioxidants, including benzotriazoles, mercaptobenzimidazoles and mercaptobenzothiazoles; antifoam agents, including emulsion-type silicones; basic dyes and Dyes, including acid dyes; and aminocarboxylic acids and the like, including ethylene diamotetraacetic acid, diethylenetriaminepentaacetic acid, their sodium or copper salts, and oxycarboxylic acids and their derivatives, such as tartaric acid and sodium gluconate. In preparing the water-based compositions of the present invention, the components used can be added in any order of addition or Certain combinations of the ingredients can be prepared prior to incorporation into products.

Generally, each component to be used should be water-soluble or previously in water-soluble form, such as their alkali metal or ammonium salts, or can be solubilized in situ. It should be something. The present invention also provides an antiwear additive comprising a combination of a nitroaromatic component and a hydroxyl-substituted aromatic acid in an effective amount for increasing the antiwear properties and lubricity of the fluid. water-based energy by addition to an aqueous composition having a viscosity of at least 10 centistokes at 40°C, containing up to 8% by weight and incorporating therein an acidic lubricant as described above. A method is also provided by which the anti-wear and lubricity properties of a transmission fluid can be increased. Such additive components can be in their solubilized form, alkali metal or ammonium salts, or in situ solubilized form. In another embodiment, when the water-based fluid composition to be treated does not contain an acidic lubricant as described herein, when adding the antiwear additive component, such components can be added to the fluid.

The following examples will further clarify the invention; however,
These examples are merely for illustrating the invention and are not intended to limit the invention in any way.

Unless otherwise specified, all parts and powder ratios are by weight. EXAMPLE 1 Wear and lubricity measurements of water-based energy transfer compositions of the present invention, as well as compositions for comparative purposes, were conducted using the ASTM D-2882-74 1 Petroleum Working Fluid Bum Pump Test (AmPOmpTe
stingOfPetrOleumHydral]11
cF1uid) J.

The operating conditions for this test are as follows. compared to compositions made without the anti-wear additives of the present invention, using various water-based compositions of the present invention and using the equipment and procedures described above. The wear of the pump cam ring and vanes was evaluated.

The proportions of ingredients used in the preparation of the compositions evaluated in this example are summarized below: H-380000
There are water-soluble products available under

The copper wear additive is from Ciba Geigy under the trademark REOMET4.
It is available under l. The results of the wear test are summarized in Table 1.

From the data shown above, it can be seen that the lubricity (antiwear properties) under high pressure of composition BD is significantly superior to that of composition A which does not contain the antiwear additive of the present invention. is clear.

Example 2 The apparatus and procedures described in Example 1 above were used to evaluate the lubricity (antiwear properties) of water-based compositions containing antiwear additives of the present invention; Comparisons were made of compositions made using one or the other of the antiwear additives, but not combinations thereof.

The proportions of the ingredients used and the results of the lubricity test are summarized in Table ■. In the composition of this example, the polymeric thickener of Example 1 was used. From the data in Table 1, it can be seen that compositions A and B containing the antiwear additive of the present invention, composition C that does not contain any antiwear additive component, and composition that does not contain any combination of antiwear additive components. It is clear that the wear resistance is significantly superior to that of materials D and E.

Example 3 Lubricity (anti-wear properties) of a series of fluid compositions containing varying amounts of water using the apparatus and procedure described in Example 1 above.
was evaluated.

The component proportions in each composition and the wear data obtained for each composition are summarized in Table 3. Example 4 The lubricity of a series of water-based fluid compositions was evaluated using the apparatus and procedure of Example 1 above, but using various types of acidic lubricant and antiwear additive components. .

The proportions of various ingredients used in each composition and the results of the pump wear test are summarized in Table 3. In the composition of this example, the polymeric thickener of Example 1 was used. From the data presented, it is clear that each composition evaluated exhibits increased wear protection, but that Composition E, prepared using lauric acid as the acid lubricant, exhibits somewhat higher wear. It is.

Claims (1)

[Scope of Claims] 1. A viscosity of at least 10 centistokes at 40° C. and up to about 80% by weight of water; at least about 0.1% by weight of an acidic lubricant; and a hydroxyl-substituted aromatic carboxylic acid component. and a nitro-substituted mononuclear aromatic compound component; Energy transfer fluid. 2. The water-based fluid of claim 1 containing at least about 20% water by weight. 3. The antiwear additive contains at least 0.0025 g-mol/l of a hydroxyl-substituted aromatic carboxylic acid component and at least 0.002 g-mol/l of a nitro-substituted mononuclear aromatic compound component.
Claim 1 consisting of a combination of 5 g-mol/l
Water-based fluids as described in Section. 4. Hydroxyl-substituted aromatic carboxylic acid component is a mononuclear hydroxyl-substituted aromatic carboxylic acid or a water-based fluid of hydroxyl-substituted aromatic carboxylic acid. 5. The acidic lubricant comprises saturated and unsaturated aliphatic carboxylic and polycarboxylic acids having at least 6 carbon atoms, aromatic carboxylic acids, and alkalis of the aliphatic and aromatic carboxylic acids. A water-based fluid according to claim 1, wherein the water-based fluid is selected from the group consisting of metal salts or organic amine salts. 6. The water-based fluid of claim 1, wherein the aqueous composition contains up to about 50% by weight of a glycol or glycol ether having from 2 to about 14 carbon atoms. 7. Claim 1, wherein the aqueous composition contains a water-soluble polymeric viscosity modifier in an amount of about 5 to 50% by weight.
Water-based fluids as described in Section. 8 Acidic lubrication characterized by incorporating into a water-based fluid an effective amount of an antiwear additive comprising a combination of a hydroxyl-substituted aromatic carboxylic acid component and a nitro-substituted mononuclear aromatic compound component. A method of increasing the anti-wear properties and lubricity of a water-based energy transfer fluid containing a sexing agent.