KR870002054B1 - Fluid composition transmitting the heat water-based - Google Patents

Abstract

Fluid compounds, containing water and having a viscosity of over 10X10-6 m2/S cSt at 40≰C, are mixed with 20-80wt.% water, 0.1-10wt.% acidic lubricity agent and an effective amount of a hydroxy- substituted aromatic acid and a nitroaromatic compound. Thus, the hydraulic fluid had greatly superior wear resistance than a similar compound without the antiwear additives that are hydroxy-subtituted aromatic and a nitroaromatic compound.

Description

Heat Transfer Fluid Compositions Based on Water

The present invention relates to a fluid composition particularly useful for delivering energy in a mechanical system, and more particularly to a fluid composition based on water that is useful for delivering hydraulic energy and has a high lubricity and good wear resistance.

Water-based hydraulic fluids are well known and have been commonly used for many years, especially where fire resistance is required. For example, water soluble glycols or glycol ethers for low temperature protection and water soluble polyalkylene oxides for viscosity control, as described in US Pat. No. 2,602,780 (Zisman et al.) And US Pat. No. 2,768,141 (Langer et al.). Water based fluids containing polymeric thickeners of polymers, such as polymers, have conventionally been used. Such compositions also contain various additives in the packaging that are added to enhance lubricity, prevent corrosion, and increase other properties required for hydraulic devices and lubricants.

Water-based hydraulic fluids are generally non-combustible, thermally stable and relatively inexpensive, but are less wear resistant than petroleum-based fluids. Fluids used in energy delivery systems must have good lubricity and mechanical stability for use in automatic lubrication pumps and valves used in conventional hydraulic systems. Good lubricity and film strength are particularly important in that they reduce wear of the flow components of hydraulic systems where the gaps between the friction surfaces are very small and the pressures can be very high.

Conventionally, in order to improve the lubricity and / or poor wear resistance of these fluids, various attempts have been made to improve polyalkylene oxide polymers, which are generally added as viscosity modifiers, or conventional oil modifiers, EP agents, corrosion inhibitors, metal ions. Methods such as mixing additives such as blocking agents or special water soluble additives such as oxyalkylene adducts of polyamides, as described in US Pat. No. 3,992,312 (Genjida et al.) Have been performed. However, none of these methods are complete, and none have a full effect, especially when wear resistance is required under high pressure conditions. Therefore, the development of a fluid based on water that meets these requirements is urgently required. Furthermore, it is also desirable to develop energy transfer fluids containing at least 50% by weight of water, which until now have been generally limited in practical use.

Therefore, the present invention is to produce an energy transfer lubricant based on water with improved wear resistance, such a fluid contains up to about 80% by weight of water, at least 0.1% by weight of an acidic lubricant, It also contains an anti-wear additive comprising a mixture of hydroxyl substituted aromatic and nitro aromatic components in an amount effective to enhance the wear resistance of the fluid composition and has a viscosity of at least about 10 microtisoke at 40 ° C. Consists of a composition. The composition of the present invention also contains from 0 to about 50% by weight of a water-soluble glycol or glycol ether of 2 to about 14 carbon atoms used as a freezing point depressant, and contains about 5 to about 50% by weight of the viscosity modifier of the water-soluble polymer.

In addition, the present invention is characterized by adding an antiwear additive which contains a mixture of a hydroxy substituted aromatic acid component and a nitroaromatic compound component to an energy transfer fluid based on water in an amount effective to improve wear resistance of the fluid composition. A method of enhancing the wear resistance of an energy transfer fluid based on water containing a lubricant.

The unique mixture of wear resistant additives described herein contains up to 80% by weight of water, which contains conventional acidic lubricants, and is much higher than the amount of water that can be used in compositions based on water that has been used as an energy transfer fluid to date. It has been found to be effective in enhancing the abrasion resistance and lubricity of energy transfer compositions based on water containing.

According to the present invention, the water-based energy transfer fluid is a water-soluble composition having a viscosity of at least 10 centistokes at 40 ° C., containing up to 80% by weight of water, and having a hydroxyl substituted aromatic acid component and a nitroaromatic compound component. It contains a conventional acidic lubricant with addition of abrasion resistant and lubricity additives.

Acidic lubricants suitable for use in the compositions of the present invention are well known materials commonly used as lubricity enhancers in hydraulic and similar fluids based on water. Such materials include, for example, saturated and unsaturated aliphatic carboxylic acids and polycarboxylic acids having 6 or more carbon atoms, such as caproic acid, caprylic acid, pelargonic acid, caproic 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, glutamic acid, butene tricarboxylic acid, and the like. Phthalic acid, terephthalic acid, isophthalic acid and trimellitic acid; also morpholine as alkali metal or organic amine salt of aliphatic and aromatic carboxylic acids, polymerized fatty acids such as dimer acid and oxycarboxylic acids and acetone such as malic acid and tartaric acid There are lecto-dicarboxylic acids such as dicarboxylic acids.

Generally, acidic lubricants are used in amounts of about 0.1 to 10% by weight, and typically about 0.5 to 2% by weight of water based compositions, although in particular cases higher amounts may be used as needed.

An essential component of the composition of the present invention is a wear resistant additive that is a mixture of a hydroxyl substituted aromatic acid component and a nitro aromatic compound component.

Nitroaromatic compounds suitable for use as wear resistant additives in the compositions of the present invention are mononuclear aromatic compounds having at least one substituent nitro group. Such nitro compounds include nitro-substituted aromatic acids and compounds such as nitro aromatic salts, esters and the like, which themselves form acid anions. Typically suitable nitroaromatic compounds include 3-nitrobenzoic acid, 4-nitrophthalic acid, 4-nitroisophthalic acid, 3,5-dinitrobenzoic acid, p-nitrocinnamic acid, and the like, and alkali metal, amine or ammonium salts thereof. have.

Suitable hydroxyl substituted aromatic acids for use in combination with the above nitro aromatic compounds include salicylic acid, dihydroxy substituted benzoic acid, and crosslinking of hydroxyl-substituted aromatic carboxylic acids of the general formulas 1) or 2) Combined dimers and the like.

In the above formula

X is a chemically stable group selected from sulfur atoms or lower alkylene, sulfonyl, amino groups,

Y and Y 'are the same or different and are a hydrogen atom, a hydroxyl group, an amino group, an alkyl group or a sulfonyl group.

Suitable crosslinked dimer acids are 5,5'-methylene disalicylic acid. Methylene or sulfur cross-linked hydroxyl substituted aromatic carboxylic acids such as pamoic acid and thiodisalicylic acid. These compounds may be present in the composition as salts, such as alkali metal, amine or ammonium salts.

Nitroaromatic compounds and hydroxyl substituted acids must be used together to prepare water-based compositions with improved abrasion resistance and improved lubricity in the compositions of the present invention. In general, the mixture of the wear resistant additive components described above should be present in an amount sufficient to provide the required wear resistance and lubricity to the composition, depending on the operating conditions and equipment requirements at the time of use. The mixing amount of the antiwear additive component that must be present is referred to herein as an "effective amount" and is defined as the minimum amount necessary to achieve the wear resistance and lubricity required in actual use.

The amount of each component of the wear resistant additive and the “effective amount” of the mixture may vary slightly depending on the use, but the amount of each component of the additive should preferably be at least about 0.0025 gram-mol (generally about 0.003% by weight) per liter of the water soluble composition. Is about 0.01 to about 0.05 or more gram-moles per liter (typically about 0.01 to about 10% by weight) of the relative proportions and the maximum amount of each component of the additive that should be present in general to be used in much excess than is actually required. The economic factors that determine are not strictly limiting.

Compositions based on water of the present invention should have a viscosity of at least 10 centistokes or greater at 40 ° C. and may contain up to about 80% water. In general, the viscosity of the water soluble composition of the present invention may vary depending on the temperature range used and the intended energy transfer application. For example, energy transfer fluids, such as hydraulic fluids, have a viscosity of about 25 to 150 centistokes, preferably 30 to 85 centistokes, at 40 ° C., and lubricating fluids may be used with similar viscosities. In order to provide fire resistance, it is desirable to produce an energy transfer fluid containing a maximum amount of water, but such a fluid must not only have a viscosity range that can operate in existing devices, but also have adequate lubricity and boundaries for mechanical configurations. It is important to be able to give lubricity. Accordingly, the water content of the compositions of the present invention is about 20 to about 80% by weight, preferably about 30 to about 70% by weight.

In order to obtain the desired viscosity for a particular application and to be able to vary the water content of such compositions over a wide range, the viscosity modifiers and / or thickeners of water-soluble polymers are generally used in the range of about 5-50% by weight of the composition Preferably 10 to 20% by weight is used. Suitable water soluble polymers for use as viscosity modifiers in the compositions of the present invention are polyalkylene oxide polymers. Such polymers are known to be water soluble compounds even though their molecular weight is large. In general, these polymers have oxyethylene groups or together with oxyethylene groups and more oxyalkylene groups (oxypropylene groups and oxybutylene groups), and these groups are irregularly distributed or collectively in the molecule. It is distributed in the average molecular weight is 400 to about 40,000 or more. The amount of oxyethylene groups in the molecule is such that the polyalkylene oxide polymer can be dissolved in water at room temperature, and the amount of oxypropylene or higher carbonoxy oxyalkylene groups is equivalent to the average molecular weight of 40,000 and It is the amount which can be existed as a liquid at normal temperature to the above, or can melt | dissolve at the temperature below about 60 degreeC. The oxypropylene / oxyethylene ratio can vary from zero to one. These polyalkylene oxide polymers can be prepared by methods known in the art by reacting ethylene oxide or a mixture of ethylene oxide with propylene oxide or a higher carbon number alkylene oxide with a compound having from 1 to 6 active hydrogen atoms. There is a number. The active hydrogen atom-containing compounds include water: monohydric alcohols such as ethanol and propanol; dihydric alcohols such as ethylene glycol; trihydric alcohols such as glycerin and trimethyllopropane; tetrahydric alcohols such as pentaerythritol; sorbitol; Same hexavalent alcohols; and monovalent or polyvalent amines such as butylamine and ethylene diamine. The product of the polyalkylene oxide in this reaction has a straight or branched oxyethylene or oxyethylene-or higher oxyalkylene chain, the end of which chain is a hydroxyl group. Some or all of these hydroxyl groups may be esterified by reaction with dialkyl sulfates such as diethyl sulfate.

Other known water soluble polymers suitable as thickeners or viscosity modifiers are, for example, ethylene oxide / propylene oxide adducts of alkylphenols described in US Pat. No. 2,768,141 (Langer et al.), And US Pat. No. 3,379,644 (katzenstein). Polymer adducts of alkylene oxides with alkylphenols, such as the ethoxylated dinonylphenols described in.

Also suitable as viscosity modifiers are water-soluble polyalkyl methacrylates, which are polymerized, for example, by polymerization of alkyl methacrylates having generally about 3 to 10 carbon atoms in the alkyl group, as specified in US Patent No. 3,352,783 (McCord). To obtain. And urethane polymers as described in US Pat. No. 3,352,783 are another water soluble polymer suitable for use as a viscosity modifier.

Other suitable water soluble polymers include polyamide esters as described in US Pat. No. 3,341,573 (shibe) and polyamide alkoxylates as specified in US Pat. No. 3,992,312 (Genjida et. Al.). .

According to the present invention, a preferred embodiment of the composition of the present invention may contain a water-soluble freezing point depressant. Commonly used water-soluble freezing point depressants are glycols or glycol ethers having 2 to 14 carbon atoms, such as ethylene glycol, diethylene glycol, triethylene glycol and their ethylene glycol ethers such as ethyl, methyl, propyl and butyl ether. Can be mentioned. In general, it is preferable to use simpler polyols such as ethylene glycol, propylene glycol, butylene glycol, glycerin and diethylene glycol. As the main component of the energy transfer fluid of the present invention, it is preferable to use a portion of glycol or glycol ether which gives a desired low temperature flow rate in combination with water.

The energy transfer fluid of the present invention comprises about 0.01 to about 5 to 010 weights of other components such as corrosion inhibitors, antioxidants, antifoams, pH regulators, dyes, metal ion barriers, and the like commonly used in water-based fluids. Small amounts up to% can be used. Such materials that may typically be used include monoethanolamine, monoisopropanolamine, diethanolamine, triethanolamine, ethylenediamine, dimethylethanolamine diethylenetriamine, cyclohexylamine, morpholine, 1,4-bis as corrosion inhibitors. (2-aminoethyl) piperidine, 2-heptadecyl-1 (2-hydroxyethyl) imidazoline, and alkali metal salts of the alkaline oxide adduct carboxylic acid which is a derivative thereof, and the like. The above-mentioned organic amines and alkali metal hydroxides mentioned as corrosion inhibitors, and the like, and antioxidants include benzotriazole, mercaptobenzoimidazole and mercaptobenzothiazole, and the like. Examples of the metal ion blockers include ethylenediaminetetraacetic acid and diethylenetriamine pen, which are amino carboxylic acids and derivatives thereof. Tatric acid, sodium and copper salts thereof, oxycarboxylic acid and derivatives thereof, tartaric acid and sodium gluconate.

The components used in the preparation of the water-based composition of the present invention may be added in any order, and some components may be mixed in advance before mixing with the composition. In general, each component used must be water soluble or previously made into a water soluble form such as an alkali metal salt or an ammonium salt or solubilizable in situ.

According to the present invention, the abrasion resistance and lubricity properties of water-based energy transfer fluids contain up to about 80% by weight of water, acidic lubricants as described above, and the nitro aromatics and hydroxyl substituted aromatic acids. A method is provided in which a wear resistant additive consisting of a mixture is contained in an amount effective to enhance wear resistance and lubricity and can be enhanced by adding an aqueous composition having a viscosity at 40 ° C. of at least 10 centistokes. Such additive components may be present in alkali metal or ammonium salt solubilized form or in solubilized form in situ.

If the fluid composition based on water does not contain an acidic lubricant as described above, these components may be added to the fluid when the wear resistant additive component is added.

The present invention can be seen more clearly from the following examples, but the examples are only intended to illustrate the invention and are not intended to limit the invention. Unless stated otherwise, all parts and percentages are by weight.

Example 1

Measurement of the abrasion and lubricity of the water-based heat transfer compositions of the present invention and the compositions used as controls are described in the hydraulic fluids described in ASTM D-2882-74 “Vam Pump Testing of Petroleum Hydraulic Fluids”. Perform as a test.

The operational conditions for this test are:

Abrasion to metal pump cam rings and vanes of various compositions according to the invention based on water using the above mentioned devices and methods were produced without using the wear resistant additives of the present invention. The wearability of the composition is evaluated.

The proportions of the components used to prepare the compositions measured in this example are summarized below.

The polymerizable thickener used in the composition of this example is a water soluble product sold under the trademark UCON 75-H-380,000 of Union Carbide Corporation. Bronze additive is marketed under the trademark registration REOMET 41 of Ciba-Geigy Corporation products.

The results of the abrasion test are summarized in Table 1 below.

TABLE 1

Composition

It can be clearly seen from the data that the lubricity (wear resistance) in high pressure compositions B to D is much better than the lubricity of composition A which does not contain the wear resistant additive of the present invention.

Example 2

The lubricity (wear resistance) of a water based composition containing the wear resistant additives of the present invention using the apparatus and method described in Example 1 was prepared as one or other wear resistant additive components (but not mixtures thereof). To a comparative composition. The proportions of components used and the results of the lubricity test are summarized in Table II below. The polymerizable thickener of Example 1 is used in the composition of this example.

The data in Table II above show that compositions A and B containing the wear resistant additives of the present invention exhibit very good wear resistance compared to compositions D and E containing no mixture of the composition C and the wear resistant additive component containing no wear resistant additive component. It can be clearly seen from.

TABLE II

Composition

Example 3

The apparatus and method described in Example 1 are used to evaluate the lubrication (wear resistance) of a series of fluid compositions containing various amounts of water. The component ratios and wear data of each composition obtained in each composition are summarized in Table III below.

TABLE III

Example 4

The apparatus and method of Example 1 are used to evaluate the lubricity of a fluid composition based on a series of water using various types of acidic lubricants and wear resistant additive components. The proportion of components used in each composition and the results of the pump-wear test are summarized in Table IV below. The polymerizable thickener of Example 1 is used in the composition of this example.

Composition E prepared using lauric acid as an acidic lubricant shows somewhat higher wear, but it is evident from the following results that each composition has enhanced wear resistance properties.

Table IV

Claims (9)

Abrasion resistant additive consisting of a mixture of 20 to 80 weight percent water, 0.1 to 10 weight percent acidic lubricant, and 0.0025 to 10 gram-mol / l hydroxyl substituted aromatic acid component and 0.0025 to 10 gram-mol / l nitro aromatic compound component A heat transfer fluid composition based on water having enhanced abrasion resistance, comprising an aqueous composition, wherein the composition comprises an aqueous composition having a viscosity at 40 ° C. of at least 10 centistokes. The heat transfer fluid composition according to claim 1, wherein the heat transfer fluid composition is based on water containing 30 to 70% by weight of water. The water based heat transfer fluid composition of claim 1, wherein the wear resistant additive is a mixture of 0.01 to 0.50 gram-mol / l hydroxyl substituted aromatic acid component and 0.01 to 0.50 gram-mol / l nitro aromatic compound component. . The heat transfer fluid composition of claim 1, wherein the nitro aromatic compound component is a mononuclear aromatic acid substituted with nitro. The heat transfer fluid composition of claim 1, wherein the hydroxyl substituted aromatic acid component is a crosslinked dimer of mononuclear hydroxyl substituted aromatic acid or hydroxyl substituted aromatic carboxylic acid. The heat transfer fluid composition of claim 1, wherein the acidic lubricant is water selected from the group consisting of saturated and unsaturated aliphatic carboxylic acids and polycarboxylic acids having 6 or more carbon atoms, aromatic carboxylic acids and alkali metal salts or organic amine salts of the aliphatic and aromatic acids. The heat transfer fluid composition of claim 1, wherein the water-soluble composition contains water containing up to 50% by weight of a glycol or glycol ether having 2 to 14 carbon atoms. The heat transfer fluid composition of claim 1, wherein the water-soluble composition contains water in an amount of 5% to 50% by weight of water-soluble polymer viscosity modifier. Characterized by mixing a wear resistant additive consisting of a mixture of hydroxyl substituted 0.0025-10 gram-mol / l and nitro aromatic compound component 0.0025-10 gram-mol / l in a water-based heat transfer fluid, A method of increasing the wear resistance and lubricity of a heat transfer fluid based on water containing an acidic lubricant.