US3711410A

US3711410A - Low water-sensitive hydraulic fluids containing borate esters

Info

Publication number: US3711410A
Application number: US00133452A
Authority: US
Inventors: A Sawyer; D Csejka
Original assignee: Olin Corp
Current assignee: Olin Corp
Priority date: 1967-04-13
Filing date: 1971-04-12
Publication date: 1973-01-16
Anticipated expiration: 1990-01-16
Also published as: DE1768133B2; GB1384251A; US3729497A; DE2141441B2; FR2307970A1; DE1768933C3; US3711412A; GB1384685A; DE1768133A1; FR2132617A2; DE2147416C2; GB1531096A; DE1768933B2; CA980756A; FR2113788B1; DE2141441C3; GB1232369A; US3625899A; DE2610934A1; FR2132617B2

Abstract

A low water-sensitive hydraulic fluid composition which contains from about 20 to about 96 percent by weight of at least one borate ester as the base fluid. Such low-water sensitive hydraulic fluids are high boiling compositions particularly useful as brake fluids.

Description

United States Patent 1 Sawyer et al. [4 1 Jan. 16, 1973' [54] LOW WATER-SENSITIVE HYDRAULIC [56] References Cited FLUIDS CONTAINING BORATE ESTERS UNITED STATES PATENTS 5 Inventors: Arthur w Sawyer, Hamden; David 3,625,899 l2/l97l Sawyer et al. ..252/75 A. Csejka, Orange, both of Conn. Primary Examiner-Leon D. Rosdol [73] Ass'gnee' Comm-anon Assistant Examiner-D. Silverstein [22] Filed: April 12, 1971 Attorney-Eugene Zagarella, Jr., Gordon D. Byrl cit, [211 pp 133,452 35151:? F. Clements, F. A. lskander and Thomas- P.

Related US. Application Data [57] ABSTRACT [63] Continuation-m-part of Ser. No. 717,996, April 1,

1968, Pat. No. 3,625,899, which isacontinuation-in- A low water-sensitive hydraulic fluid composition P of y 1967, abandonedwhich contains from about 20 to about 96 percent by weight of at least one borate ester as the base fluid. [52] US. Cl ..252/78, 252/49. 6 s |ow water Sensitive hydraulic fluids are high 1 [51] Int. Cl. ..C09k 3/00, ClOm 3/48 ing compositions particularly useful as brake fluids [58] Field of Search ..252/74, 75, 77, 78, 49.6

25 Claims, No Drawings LOW WATER-SENSITIVE HYDRAULIC FLUIDS CONTAINING BORATE ESTERS This application is a continuation-in-part of co-pending application Ser. No. 717,996 filed Apr. 1, 1968 and now U.S. Pat. No. 3,625,899, which in turn was a continuation-in-part of application Ser. No. 653,338 filed July 14, 1967 and now abandoned.

This invention relates to new and improved, low water-sensitive hydraulic pressure transmission fluids for use in fluid pressure operating devices such as hydraulic brake systems, hydraulic steering mechanisms, hydraulic transmissions, hydraulic jacks, hydraulic lifts, etc. More particularly, this invention relates to hydraulic fluids having a low sensitivity to water which employ as the base fluid one or more borate esters of glycol monoethers. The term base fluid as used throughout the specification and claims means the major active ingredient (not necessarily present in the major or largest proportion) of the hydraulic fluid, i.e. that ingredient which is most active in maintaining the desired properties of the hydraulic fluid especially in the face of aqueous contamination.

A great number of hydraulic fluid compositions have been suggested in the art. Commonly, the hydraulic pressure transmission fluids, such as brake fluids are made up of three principal units. The first is a base or lubricant for the system which may include heavy bodied fluids such as polyglycols, castor oil, mixtures of these materials, etc. Diluents, which are employed for the purpose of controlling the viscosity of the fluid as represented by glycol ethers, glycols, alcohols, etc., form the second basic unit. Finally, the third basic unit is represented by an additive or inhibitor package comprising small quantities of materials which are added to control or modify various chemical and physical properties of the fluid, e.g. to reduce oxidation, to improve wetting and flow and to maintain the pH of the hydraulic system above 7 in order to minimize corrosion. By varying the composition, particularly desired properties can generally be attained. However, hydraulic fluids have been subject to increasingly stringent requirements with regard to many properties, e.g. boiling point, viscosity, corrosiveness, lubricity, pour point and rubber swell. This has made it extremely difficult to I produce a desirable fluid since very often a change in composition which improves one or more of these or other essential properties will detrimentally effect some other property. This problem is magnified when water gets into the hydraulic fluid since many of the properties are effected, some to a substantial extent.

Hydraulic fluids, as exemplified by the commercial motor vehicle brake fluids, are hydroscopic by nature and therefore, absorb moisture from ambient atmospheres with resulting degradation of their boiling point. This effect that water has on the boiling point of hydraulic fluids has been studied extensively and a great deal of public interest has been generated concerning the safety qualities of hydraulic fluids especially brake fluids as is pointed out, for example by C. F. Pickett in an article entitled Automotive Hydraulic Brake Fluids published as part of the 51st Mid-Year Meeting Proceedings of the Chemical Specialties Manufacturing Association, Inc., NY. (1965). As indicated in the above-noted article, when a small amount of water, e.g. 3.5 percent by weight was added to various commercial brakefluids, some'having initial available commercial fluids is more readily understood when the following facts are considered. First of all, it is known that hydraulic brake fluid temperatures can reach rather high levels and often approach and even exceed the 300F. level. This is substantiated by the results of field studies in 1966 by the Society of Automotive Engineers (See SP-338, Automotive Brake Evaluation Under Customer Usage Conditions, pp.l and 2, 1968) wherein it was shown that brake fluid temperatures approached 270F. under typical driving conditions of vehicles which were loaded only to their manufacturers recommended limit. it could reasonably be assumed from these results, that when abnormal conditions are encountered temperatures would exceed 270F. and approach and even pass It is also known that so-called conventional type motor vehicles often accumulate small amounts of moisture in their hydraulic fluids during usage. This is substantiated by results disclosed in a meeting of the SAE Hydraulic Brake Systems Actuating Committee in 1966 (See minutes of meeting of October 26-27, 1966) and further by the report of Charles B. Jordan, Effect of Water on Hydraulic Brake Fluid, U.S. Army Coating and Chemical Laboratory, May, 1966. These articles clearly show that amounts of water have been accumulated in hydraulic brake fluids under use conditions in varying proportions and have often reached levels of up to 3.5 percent and even have been as high as 5 percent by weight. The fact that hydraulic fluids do accumulate some water during usage is further supported by the SAE Standard J-l703 which requires certain water'tolerance tests to be passed after the addition of 3.5 percent by weight water and also, requires a corrosion test to be passed after the addition of 5 percent by weight water to the brake fluid.

From the above discussion, it can readily be understood that hydraulic fluids can under certain conditions approach temperatures of the magnitude of 300F. and higher and furthermore such fluids can accumulate small amounts of moisture during usage. Thus, hydraulic fluids which have low dry boiling points and are sensitive to water to a large degree can encounter problems such as vapor lock which can result in the failure of a hydraulic brake system and consequently cause an accident. This clearly illustratesthe advantage of the hydraulic fluids of this invention which possess a high degree of water tolerance and are able to maintain their boiling points at higher and safer levels.

The seriousness of the problem of water accumulation and its effects on the hydraulic fluid system is further signified by the fact that the U.S. Department of Transportation presently is considering acceptance of standards for motor vehicle brake fluids which would for the first time include a minimum wet reflux boiling point (equivalent to approximately 3.5 percent by weight of water added). The proposed standards include one for a fluid having a minimum dry reflux boiling point of 401F. and a minimum wet reflux boiling point of 284F. and another for a fluid having a minimum dry reflux boiling point of 446F. and a minimum wet reflux boiling point of 320F. The term dry reflux boiling point as used herein is defined as the boiling point of the hydraulic fluid as delivered to the consumer or distributors (Le. fluid ready for use). Wet reflux boiling point is the boiling point of the hydraulic fluid after a discrete amount of water has been added thereto.

The above considerations clearly point out the need for a hydraulic fluid which has a low sensitivity to water and can maintain certain properties and characteristics when amounts of water commonly encountered during use are present.

There are various hydraulic fluids known in the art as shown for example in Introduction to Hydraulic Fluids by Roger E. Hatton, Reinhold Publishing Corp. (1962); U.S. Pat. No. 2,998,389 issued to Chester M. White on August 29, 1961 and U.S. Pat. No. 3,377,288 issued to Arthur W. Sawyer on Apr. 9, 1968. Generally, these fluids do not have the low water sensitivity that is required to maintain their original properties after there is an accumulation of moisture.

One of the basic-objects of this invention is to prov vide hydraulic pressure .transmission fluids for use in hydraulic systems which retain to a high degree, their original properties when water is accumulated, i.e. they have a low sensitivity to water.

Another object of this invention is to provide hydraulic pressure transmission fluids which are extremely high boiling compositions and which maintain relatively high boiling points even when water is accumulated in the hydraulic fluid composition.

Another object of this invention is to provide a hydraulic pressure transmission fluid having an initial dry reflux boiling point of at least about 450F. and a wet reflux boiling point of at least about 320F. when about 3.5 percent by volume of water (equivalent to about 3 .4 percent by weight) is present.

A further object of this invention is to provide a hydraulic pressure transmission fluid having a high degree of lubricity while maintaining desired viscosities within a predetermined range under a wide variation of temperature conditions.

These and other objects of this invention are accomplished .with the hydraulic fluids of this invention which generally comprise from about to about 96 percent by weight, based on the total hydraulic fluid weight, of at least one borate ester of a glycol monoether as the base fluid. Generally the remainder of the fluid is comprised of diluent and one or more additives.

The hydraulic fluids of this invention are especially desirable because they have a low water sensitivity and are particularly useful as brake fluids since they can retain to a high degree the original properties of the fluid after water is accumulated. Additionally, the hydraulic fluids of this invention are of low cost, possess a high boiling point, are essentially odorless and colorless, possess a high degree of compatibility with other fluids and exhibit a very low rate of corrosivity.

Another feature of this invention is the highly satisfactory rubber compatibility of the novel fluids as shown in tests carried out according to SAE Standard Jc (see Table l). Fluids previously employed have utilized more expensive materials such as 2-ethylhexanol, heptanols, butyl ethers of glycols, or diethers of glycols in an amount from about 10 to about 30 percent by weight of the total composition to achieve the desiredrubber swelling characteristics whereas the hydraulic fluids of this invention provide satisfactory rubber swelling properties without the addition of a component for this purpose. The importance of the rubber swelling properties of the fluid cannot be overlooked since too little swelling will result in leakage of the fluid passed the rubber cup sealing means and passed the piston in hydraulic cylinders with corresponding loss of power. On the other hand fluids which cause too much rubber swelling are not desirable in that they destroy the structural properties of the rubber sealing cups in hydraulic cylinders, which in turn results in malfunction or inoperativeness of the unit.

The hydraulic fluids of this invention generally comprise three principal units: (l) base fluid, (2) diluents and (3) additives. The components of these units and the proportions thereof are described in detail below.

BASE FLUID The base fluid employed in the novel hydraulic fluids of this invention generally comprises at least one borate ester of a glycol monoether. More particularly, the hydraulic fluids of this invention will comprise from about 20 to about 96 percent by weight, based on the total hydraulic fluid weight, of at least one borate ester of a glycol monoether. Preferably, the amount of borate ester will vary from about 30 to about 92 percent and more preferably from about 54.5 to about 92 percent by weight, based on the total hydraulic fluid weight. When using hydraulic fluids which can safely operate under somewhat lower temperature conditions, the range of borate ester used may vary from about 20 to about 55.4 percent and preferably from about 30 to about 54.4 percent by weight, based on the total weight of the hydraulic fluid. Generally, when 54.5 percent borate ester is used, the hydraulic fluid can maintain a wet boiling point (-35 percent by volume water added equivalent to about 3.4 percent by weight) of at least about 350F. When 20 and'30 percent borate ester is used, a wet boiling point of at least about 320F. and 330F. respectively can vbe maintained.

Although a wide variety of borate esters can be employed as the base fluid in the novel hydraulic fluids of this invention, an especially useful class of borate esters are the so-called tri borate esters of glycol monoethers having the general formula l l( a)u ]3 l wherein R, is a lower alkyl radical containing from one to four carbon atoms, preferably one to two, R, is al kylene of from two to four carbon atoms, preferably two to three, and y is an integer from two to four inclusive. The R and R, groups may be either straight or branched chain structures. Borates of the above-mentioned type include, for example: [CH (OCH CH O] mixture is maintained between about 0C. and about 3 190C. and desirably at the distillation temperature of the water-solvent azeotrope. After essentially complete removal of the water formed during esterification, the excess solvent is conveniently removed from the reaction mixture by distillation. The borate ester product, which is left in a residue, may then be recovered by distilling under reduced pressure or by extraction with a suitable solvent followed by evaporation of the solvent. For example, the compound [C H (OCH CH O] --B can be prepared by reacting two moles of C l-1 (OCHCH Ol-l, 0.67 mole of orthoboric acid and 700 ml. of ethylbenzene with heating and mixing to yield 198 grams of the ester, a water-white liquid boiling at 222223 C. (5 mm. Hg). It is noted that in the preparation of these esters, a small proportion of concomitant reaction products may be formed and other minor impurities may also be present. Generally, the predominant portion of such other reaction products formed is a boroxine type compound having the following general structure:

wherein R, is derived from the particular glycol ether being used, e.g. CH;,(OCH CH O-, C H (OCH cH O, etc. The amount of such concomitant reaction products formed and other impurities present may be up to about 10 percent by weight if the reacted mixture is not distilled. Distillation will reduce the amount of other reaction products and impurities to about 1 percent or less, however, either the distilled or undistilled product can be used provided the reaction medium or solvent is stripped off. The term borate ester as used in the specification and claims is intended to include relatively pure borate ester as well as crude borate ester which contains impurities and other by-products formed during preparation as described above. The preparation of the tri-borate esters per se is more completely described in US. Pat. No. 3,080,412 issued to D. M. Young on Mar. 5, 1963. It is of interest to note that this patent (US. Pat. No. 3,080,412) discloses the use of tri-borate esters, such as tris [2-(2- ethoxyethoxy)ethyl] borate, as stabilizers and corrosion inhibitors for lubricants and non-aqueous hydraulic fluids. However, use of these esters for such purposes, i.e. as a stabilizer or corrosion inhibitor, would not impart satisfactory low water sensitivity to the hydraulic fluid since such usage would generally be in very small or minor proportions (eg from 0.5 to 2 percent) in accordance with the generally accepted practice in the art (e.g. see US. Pat. No. 3,403,104 issued to P. B. Sullivan on Sept. 24, 1968).

A second highly useful class of borate esters includes compounds of the general formula: [R (OCH CHR (OCH2CH 3)nO]3 B (ll) wherein R and R are independently selected from the group consisting of hydrogen and methyl, m and n are positive integers whose sum is from 2 to 20 and R is alkyl of from one to four carbon atoms and with proviso that one of R and R is methyl and one of R and R is hydrogen. R may be straight chain or branched alkyl. Borate esters of Type ll can be prepared in the general way as those esters previously described (Type 1) above, utilizing the so-called block type glycol monoethers. The preparation of esters of Type ll is described in detail in US. Pat. No. 3,316,287 issued to L. G. Nunn, Jr. et al. on Apr. 25, 1967. Type II borate esters useful in preparing the novel fluids of this invention include, for example:

Another class of borate esters useful in the fluid compositions of this invention include esters having heteric oxyalkylene chains, that is, oxyalkylene chains in which oxyethylene and oxypropylene units are distributed randomly throughout the chain. These Type III esters have the general formula:

1[ gl )a (m) Rg represents a heteric oxyalkylene chain having the formula:

[ Z UT z QS where the sum of r and s is not more than 20 and wherein the weight percent of oxyethylene units in the said chain is not less than 20 based on the total weight of all the oxyalkylene units in the chain and R, is alkyl of from one to four carbon atoms and may be straight or branched chain. The preparation of Type 111 esters can be accomplished in the same general manner as the preparationof Types 1 and 11 described above by reacting orthoboric acid in the presence of toluene with a heteric glycol monoether of the formula:

R,[Rg]Ol-l where R, and Rg have the same meaning as previously set forth. Glycol monoethers of this class can be conveniently prepared by methods well known in the art such as the process described in U.S. Pat. No. 2,425,845 issued to W. J. Toussaint et al. on Aug. 19, 1947.

A fourth type of borate esters suitable for use in the fluid compositions of this invention have the general formula:

preferably one to two, R' is hydrogen or alkyl of from one to four carbon atoms, preferably one to two, R" is alkylene of two to four carbon atoms, preferably two to three, and y is two to four. The R, R and R groups may be straight chained Qrbranched. It is also intended that the alkylene oxide group (O-R") in the above formula (V) include mixtures of said alkylene oxides.

Illustrative of the diluents of this type (V) are the following compounds: diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monoisopropyl ether, diethylene glycol monoisobutyl ether, triethylene glycol monomethyl ether, triethylene glycol monoether ether, triethylene glycol mono-n'butyl ether, tetraethylene glycol monomethyl ether, tetraethylene glycol monoethyl ether, dipropylene glycol monomethyl ether,

wherein T T and T are each an independently selected alkyl group having from one to four carbon atoms, R.,, R R R R and R are independently selected from the group consisting of hydrogen and methyl, n and m are positive integers independently selected in each chain and whose sum in each chain is from 2 to 20, and with the proviso that in no more than two of the chains is the sum of n and m the same. It is also noted that T T and T may be a straight or branched chain alkyl group.

Borate esters of this type can be prepared in the same way as the process described for Type I esters previously mentioned.

Type IV borate esters suitable for use in the fluids of this invention include, for example:

dipropylene glycol monoethyl ether, tripropylene glycol monomethyl ether, tripropylene glycol monoethyl ether, tripropylene glycol mono-n-butyl ether, tetrapropylene glycol monomethyl ether,

It gramme ted Embers esters or T es I], lit and IV may include concomitant reaction products and other impurities of the type as described above for Type I esters. Reference to these types of borate esters in the specification and claims is intended to include relatively pure borate ester as well as crude borate ester which contains impurities and other by-products formed during preparation as described above for Type I.

DILUENTS This diluent portion of the hydraulic fluid composition of this invention generally will comprise one or more compounds selected from the group consisting of (a) glycol monoethers or diethers (b) glycols and polyglycols and (c) aliphatic saturated alcohols.

More particularly, the glycol monoethers or diethers have the formula:

l "l., 0 wherein R is alkyl of from one to four carbon atoms,

mula (V) may be used, the following glycol ethers are particularly useful: diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, tetraethylene glycol monoethyl ether and tetraethylene glycol monobutyl ether.

The glycol ethers are the most preferred diluent since their use will result in a fluid having a desirably high boiling point with good viscosity and water solubility properties. Most preferred of the glycol ethers are the ethylene glycols.

The second group of useful diluents are the glycols and polyglycols, including alkylene, polyalkylene and polyoxyalkylene glycols, having a molecular weight of from about 60 to about 450 and preferably from about to about 300. Illustrative of such type diluents are the following compound: ethylene glycol, propylene glycol, hexylene glycol, diethylene glycol, dipropylene "@861, I triethylene glycol, tripropylene glycol,

polyethylene glycol and polypropylene glycol.

The use of the glycols and polyglycols as diluents is not as desirable as the glycol ethers since their use may result in some loss of fluidity at very low temperatures, however, they may be used in conditions where the requirements are not as demanding.

The third type of useful diluents are aliphatic, saturated, monohydric alcohols containing from six to 13 carbon atoms, preferably from eight to 10. Illustrative of such diluents arc the following alcohols: hexanol, octanol, isooctanol, decanol, isodecanol, dodecanol, and tridecanol.

Since the use of the aliphatic alcohols in a high boiling hydraulic fluid may result in some loss of water solubility, they are not as desirable as the glycol ethers. However, they may be used in conditions where the requirements are not as stringent.

The diluent portion of the hydraulic fluids of this invention generally will comprise from to about 80 percent by weight, preferably from about 3 to about 70 and more preferably from about 3 to about 45 percent by weight, based on the total weight of the hydraulic fluid composition.

While the above diluents, especially the glycol ethers, are particularly preferred, other diluents may be used if the desired properties and characteristics of the hydraulic fluid can be attained. For example, certain diesters derived from organic aliphatic acids and aliphatic alcohols might be usefully employed. Examples of diesters which might be used include dibutyl adipate, bis(methoxyethyl) azelate, diisopropyl succinate, dipropylene glycol diproprionate and triethylene glycol dibutyrate.

ADDITIVES When desired, various additives may be added to the hydraulic fluids of this invention to control or modify various chemical and physical properties of the fluids. Among the various types of additives which can be added to the hydraulic fluids of this invention are included: inhibitors for pH and corrosion control, antioxidants, rust inhibitors, viscosity index improvers, pour point depressants, lubricity agents, antifoamants, stabilizers, demulsifiers dyes and odor suppressants. Generally, the total amount of additives which may be incorporated into the fluid composition will vary depending on the particular composition and the desire properties. More particularly, the total amount of additives .will comprise from 0 to about percent and preferably from about 0.1 to about 8.0 percent by weight based on the total weight of the hydraulic fluid composition.

For example, inhibitors for pH and corrosion control, such as alkaline inhibitors as exemplified by the alkali metal borates, can be employed in an amount sufficient to maintain alkaline conditions in the fluid compositions, e.g. a pH value of from about 7.0 to about 11.5. These inhibitors are generally added in an amount of from 0 to about 8.0 percent by weight based on the total weight of the hydraulic fluid composition and preferably from about 0.2 to about 6.0 percent by weight on the same basis. Useful inhibitors include alkali metal borates, such as sodium borate, potassium tetraborate, etc.; sodium meta arsenite; alkali metal salts of fatty acids, such as potassium oleate, the potassium soap of rosin or tall oil; alkylene glycol condensates with alkali metal borates, such as the ethylene glycol condensate of potassium tetraborate; amines, for example, ethanolamine, methyl diethanolamine, diethanolamine, isopropanolamines( mono, di and tri), di(2-ethylhexyl) amine, di-N-butyl amine, monoamyl amine, diamylamine, dioctylamine, salicylal monoethanolamine, di-B-naphthyl-p-phenylene diamine, N,N '-disalicylidene LZ-pmpanediamine,

N,N-disalicylal ethylene diamine, dicyclohexylamine, and amine salts such as mono or dibutyl ammonium borate; phosphites, such as triphenyl phosphite, tri(tertamylphenyl) phosphite, diisopropyl phosphite, etc.; mercaptobenzotriazole; morpholine compounds including alkyl morpholines having from one to four carbon atoms in the alkyl group such as N-ethyl morpholine, N-isopropyl morpholine, N-butyl morpholine; N-phenyl morpholine, N-(Z-aminoethyl) morpholine, N-(Z-hydroxyethyl) morpholine, etc.; phosphates, including the alkali metal phosphates, dibutyl amine phosphates, the dialkyl acid 0- phosphates and amine salts thereof; triazoles including benzotriazole, 1,2-naphthotriazole, 4- nitrobenzotriazole, tolutriazole, aminobenzotriazoles such as S-acylaminobenzotriazole, and alkyl triazoles having one to 10 carbon atoms in the alkyl group as exemplified by methyl triazole, ethyl triazole, n-propyl triazole, tertiary butyl triazole, hexyl triazole, isodecyl triazole, etc. Other useful corrosion inhibitors include adenine, 4-methylimidazole, 3,5-dimethyl pyrazole, 6- nitroidazole, imidazole, benzimidazole, quaninie, in-

dazole, ammonium dinonylnaphthaline sulfonate, dioleyl thiodipropionate, ethylbenzoate, ethyl-paminobenzoate, cyclohexyl ammonium nitrite,

diisopropyl ammonium nitrite, butynediol, glycerin, l,3,5-trimethyl-2,4,6-tris (3,5-di-tert. butyl-4-hydroxybenzoyl), 4,4'-methylene bis(2,6-di tert. butylphenol), 4-hydroxy methyl-2,6-di-tert. butylphenol, 4,4'-methylene bis (4methyl-6-tert. butylphenol), salicylal-o-aminophenol, 2,6-di-tert. butyl-2- dimethylamino-p-cresol, 4,4-thio bis-(6-tert. butyl-ocresol). Mixtures of the above-mentioned inhibitors can be employed if desired.

An antioxidant may be used as an additive in the hydraulic fluid compositions of this invention if desired. Generally the amount of antioxidant used will vary from 0 to about 2 percent and preferably will be from about 0.001 to about 1.0 percent by weight'based on the total weight of the fluid composition. Typical antioxidants include phenolic compounds, such as 2,2-di- (i-hydroxyphenyl) propane, phenothiazine, phenothiazine carboxylic acid esters, N-alkyl or N arylphenothiazines, such as N-ethyl phenothiazine, N- phenyl phenothiazine, etc.; polymerized trimethyldihydroquinoline; amines, such as phenyl-alphanaphthylamine, phenyl-beta-naphthylamine, dioctyl diphenylamine, N,N-di-B-naphthyl-p-phenylene diamine, p-isopropoxy diphenylamine, N,N-dibutyl-pphenylene diamine, diphenyl-p-phenylene diamine, N,N-bis( l ,4-dimethylpentyl)-p-phenylene diamine, N,N'-diisopropyl-p-phenylene diamine, p-hydroxydiphenylamine, etc.; hindered phenols such as dibutyl cresol, 2,6-dimethyl-p-cresol, butylated 2,2-di-(4- hydroxyphenyl propane, n-butylated aminophenol, butylated hydroxyanisoles, such as 2,6dibutyl-p-hydroxyanisole; anthraquinone, dihydroxyanthraquinone, hydroquinone, 2,5-di-tertiarybutylhydroquinone, 2-tertiary butylhydroquinone, quinoline, p-hydroxydiphenylamine, phenyl benzoate, 2,6-dimethyl p-cresol, p-

hydroxyanisole, nordihydroquaiaretic acid, pyrocatechol, styrenated phenol, polyalkyl polyphenols, sodium nitrite, etc. Mixtures of the abovementioned antioxidants can be employed, if desired it should be emphasized that with a variety of the fluids of this invention, which are suitable for a wide range of industrial application, a separate antioxidant is not required.

The above-noted inhibitors and additives are merely exemplary and are not intended as an exclusive listing of the many well-know materials which can be added to hydraulic fluid compositions to obtain various desired properties. Numerous additives useful in hydraulic fluids are disclosed in Introduction to Hydraulic Fluids by Roger E. Hatton, Reinhold Publishing Corp., (1962).

Formulation of the novel fluid of this invention is accomplished by blending the components to a homogeneous stage in a mixing vessel. The preferable blending temperature is from about 50l25F. It is preferable to warm the solution during preparation to facilitate dissolution. The blending of the compounds is conveniently conducted at atmospheric pressure in the absence of moisture.

In general, any suitable method can be used in preparing the liquid compositions of this invention. The

components can be added together or one at a time, in"

any desired sequence. It is preferable, however, to add the glycol ether component. All components are mixed until a single phase composition is obtained.

The following examples which illustrate various embodiments of this invention are to be considered not limitative.

EXAMPLE 1 A hydraulic fluid having the following composition was prepared:

Percent by Weight [CH,(OCH,CH O] -B 67.39 Triethylene glycol monomethyl ether 23.20 Diethanolamine 1.78 Polyethylene glycol (Moi. wt. 300) 7.62 Sodium Nitrite 0.01

Total 100.00

The fluid composition of this example was tested according to the procedures set forth in Hydraulic Brake Fluid SAE Standard J70c for heavy duty types 70R] and 70R3 hydraulic brake fluid. Pertinent data relating to these tests, which illustrates the outstanding properties of this novel fluid, is shown in Table l. The fluid of Example 1 was found to satisfy completely the requirements for SAE heavy duty type 70R3 hydraulic brake fluid. Table 2 illustrates the effect of added water on the hydraulic fluid of Example l and compares it with the effect of water on a conventional or commercially the antioxidant and alkaline inhibitor as a solution in available fluid.

TABLE 1.-PROPERTIES OF WATER I NSE NSITIVE BRAKE FLUID ()F EXAMPLE 1 (Tests conducted according to procedures set forth in Society of Automotive Engineers Standard .1700) Test results water insensitive SAE R3 fluid of Test specification Example 1 Boiling point (min. 374 F 407 F. Flash point (min.) 179.6 F 330 F. Viscosity:

40 F. (max.) 1,800 cs 1,790 es. 122 F. (m n.).. 4.2 cs 7.34 cs. 212 F. (mm.) 1.5 cs 2.71 cs. pH 71l.5 7.70. Stability at high temperature:

Boiling point (min) 495 F. Boiling point change (max.) 2 F. Corrosion test (wt. change mgJsq. cm

te Tinned iron Sedimentation, percent by vol. (max.)

Gelling fluid/water mixture on Crystalline deposit jar walls or strips. 0. pH fluid/water mixture 7.50. Rubber cups:

Swelling (max.) Softening (max.) Fluidity and appeeranc (1 test) 40 F. six days: Black contrast lines, HP chart Stratification-scdimentatlon. Air bubble travel time (max.) 10 sec Z sic 68 l six hours:

Black contrast lines, HP chart Clearly discernible" Clear. StratificaMon-sedimentation. None None. Air bubble travel time (max.) 86 see 5 see.

Patent No. 4,114,514 li-Fol. N0. 070

' Evaporation test:

Percent loss (max.) percent 60 percent. Gritty or abrasive reside. N one None. Pour point (max.) 23 F 23 F. Water tolerance:

40 F., 24 hours:

Black contrast lines, HP chart (Jlcarly discernible. Clear. Stratification-sedimentation.. None..." None. Air bubble travel time (max.) 10 sec 3 sec. F., 24 hours:

Stratification None......... None. Sedimentation, percent by vol. (max.). 0.05 percent... 0.0l percent.

n a. M- Iablc l.. Continued Test results water insensitive SAE 70R3 fluid of Test specification Example 1 Compatibility: 7 WE, ,7 V N 40 F., 24 hours:

Black contrast lines, HP chart. Clearly dlsccrniblo Clear. Stratiiication-sedimentation. None Nono. 140 F., 24 hours:

Stratification None Do. Sedimentation, percent by vol. (max) 0.05 percent 0.01 percent. Resistance to oxidation (peroxide test):

Fitting of metal strips:

Aluminum None None. Cast iron .do Do. Weight loss in mg./sq. cin.:

Aluminum alloy (max.) 0.05 0.00. Cast iron (main) 0.30 +0.01. Effect on rubber -158 F.:

Hardness decrease:

Natural (max.) 10 2. SBR (man).-.- 10 3. Base diameter increase: 7

Natural 0.006"0.055 0.013. SBR- 0.006"-0.056 0.019.

Pat. No. 4, 114, 514 671 Disintegration rubber cups None None.

Effect on SBR rubber --248 F.:

Hardness decrease (max.) 4. Base diameter increase 0.006"-0.055 0.033. Disintegration rubber cups-.- None None.

Color Straw.

Simulated Service Performance Procedure No. 2 (85,000 strokes; 248 F./1,000 p.s.i.)

Corrosion of metal parts as evidenced by discernible pitting None None. Change in initial diameter of any cylinder or piston (max.) 0.005 Do. Lip diameter interference set of rubber cups:

Wheel cylinder cups (max.) 65 percent ,7.2 percent. Master cylinder cups:

Primary (max.) do 15.4 percent. Secondary (ma-x.) .do 0.0 percent. Hardness decrease of rubber cups:

Wheel cylinder cups (max.) 15 4. Master cylinder cups:

Primary (max.) 15 6. Secondary (rnax.) 15 5. Operating condition of rubber cups as evidence by excessive tackiness, scoring, scuifing, blistering, cracking, Satisfactory Satisfactory.

chipping, or change in shape.

Fluid loss during any 24,000 stroke period (max.)

Freezing or malfunction of cylinder pistons Gum deposited on metal parts of cylinder walls that a e or cannot be removed with ethanol. Do.

Deposits formed or adhering to cylinder walls that are abrasive or cannot be removed with ethanoL. Do.

Fluid loss during 100 strokes at end of test (max.) 36 m1 coondition of fluid and brake cylinders by evidence of sludg elling or grlttiness likely to cause improper None None.

ra e act on.

Percent sediment in fluid drained from wheel cylinders 72 hours equilibrium (max.) 1.5 percent 0.05 percent.

Percent sediment in fluid drained from master cylinder 72 hours equilibrium (max.) d Do.

Decrease in base diam. of rubber cups:

Wheel cylinder cups (max.) 0.020 percent, Master cylinder cups:

Primary (man) 0.025 percent. Secondary (max.) 0.035 percent.

TABLE 2.EFFECT OF ADDED WATER 0N BOILING POINT EXAMPLE 2 OF HYDRAULIC FLUID OF EXAMPLE 1 Percent by 1: Retlu boiling point, 11 weight LOW water :i( z 2)3 ]3 Cogveni seisitiivt Triethylene glycol monomethyl ether 6.68 u 0 Polyethylene glycol (Mol. wt. 300) 1.83

water fluid A Example 1 Methyldiethanolamine 1.99

0.0 ercent b vol. (dry) 484 497 sod'um Nm'lte 1.0. 380 450 5 Total 100.00

3.38 294 are 5 V V k *3.5 ml. H O/IOO ml. fluid. The reflux boiling point (dry) of the above fluid was measured and found to be 552F. at atmospheric presf 1 icomposltlon of Conventlonal Flmd A was as sure. To test the low water sensitivity of the fluid com- 0 o weight position of Example 2 a composition consisting of I00 percent A 50-50 weight percent ethylene oxide-propylene oxide random parts by volume of the flu ld plus 35 parts by volume of 31% 3230 ea p od with butyl alcohol cwt. 20 0 water was prepared and it was found to have a reflux latens nab}man gii n'gitajj"31331332313313:1:33;: 1g boiling point (wet) at atmospheric pressure of 402F.

riethylenegyco monoe y at er Triethylene glycol monobutyl ether 10.0 g p that the fluid has an exceptional} low water Ethylene glycol sensitivity. For example, when a conventional brake Dlphenylol propane... -1 n h b o Condensate oi7 moles of hylenc glycol with 1 mole of potns- 0 2 U1 W 16 0115 above 550 F. 18 tested in the same slum L; manner, the reflux boiling point drop is about 250F or Total 100.0 more The fluid composition of this example was also tested according to the procedures of SAE Standard J70c for water tolerance and evaporation and was found to pass both of these tests. 1 All reflux boiling point measurements in this example and in the other examples of this specification were conducted in accordance with the procedure of SAE Standard 1700.

EXAMPLE 3 Percent by Weight [CH,(OCH,CH,) O],- B 66.0 Triethylene glycol monomethyl ether 21.9 N-ethyl morpholine 4.4 Polyethylene glycol (M01. wt. 300) 7.7 Total 100.0

The reflux boiling point (dry) of this fluid was measured and found to be 440F. at atmospheric pressure. On addition of 3.5 parts by volume of water to 100 parts by volume of the fluid there was obtained a fluid having a reflux boiling point (wet) at atmospheric pressure of 353F. When tested according to theprocedure of SAE Standard .l70c, this fluid passed the evaporation requirement for SAEheavy duty type 7OR3 brake fluid.

EXAMPLE 4 Percent by Weight l a(OCH: 1)a0]:-B 67.04 Triethylene glycol monomethyl ether 21.72 N-phenyl morpholine 1.89 Diethanolamine 0.85 Polyethylene glycol (M01. wt. 300) 8.50

Total 100.00

Properties:

Reflux boiling point (dry) at atmospheric pressure Reflux boiling point wet) at atmospheric pressure of 3.5 parts by volume of water and 100 parts by volume of fluid of Example 4 367F.

Reflux boiling point (wet) at atmospheric pressure of 3.5 parts by volume of water and 100 parts by volume of fluid of Example 5 372F.

Viscosity 40F. 1620 cs.

212F. 2.74 cs.

Water Tolerance Test Passed water tolerance test at -40F. and 140F. ac-

cording to procedure of SAE J70c.

EXAMPLE 6 Percent by 7 Weight [C,H,(OCH,CH,) O],-B 82.78 Triethylene glycol monoethyl ether 10.00 Methyldiethanolamine 2.20 Polyethylene glycol (Mol. wt. 300) 5.00 Sodium. nitrite 0.02 Total 100.00

16 Properties:

Reflux boiling point (dry) at atmospheric pressure Reflux boiling point (wet) at atmospheric pressure of 3.5 parts by volume of water and 100 parts by volume of fluid of Example 6 383F.

Viscosity 40F. 1910 cs.

212F. 2.82 cs. Water Tolerance Test Passed 40F. and 140F. water tolerance test according to procedure of SAE J c.

EXAMPLE 7 Percent by Weight [CH,(OCH,CH,),O],-B 70.13 Triethylene glycol monomethyl ether 20.00 Diethanolamine 1.86 Triethylene glycol (Mol. wt. 150) 8.00 Sodium nitrite 0.01 Total 100.00

Properties:

Reflux boiling point (dry) at atmospheric pressure Reflux boiling point (wet) atmospheric pressure of 3.5 parts by volume of water and parts by volume of fluid of Example 7 381F.

Viscosity 40F. 2050 cs. 212F. 2.80 cs. Corrosion Test Passed corrosion test according to procedure of SAE J70c.

Water Tolerance Test Passed water tolerance test at 40F. and F. ac-

cording to procedure of SAE J70c.

EXAM PLE 8 Percent by Weight [C H (OCH,CH,),0];,-B 28.29 [CH;,(OCH,CH,) .,O],-B 55.58 Triethylene glycol monomethyl ether 8.05 Polyethylene glycol (Mol. wt. 300) 6.1 l Methyldiethanolamine I 1.94 Sodium nitrite 0.03

Total 100.00

Properties:

Reflux boiling point (dry) at, atmospheric pressure Reflux boiling point (wet) at atmospheric pressure of 3.5 parts by volume of water and 100 parts by volume of fluid of Example 8 400F.

Viscosity 40F. 2540 cs.

212F. 3.27 cs. Water Tolerance Test Passed water tolerance test at -40F. and 140F. ac-

cording to procedure of SAE .l7Oc.

EXAM PLE 9 Percent by Weight Boratc Ester D (Described below) 8046 Triethylene glycol monobutyl ether 1 1.40 Diethanolamine 2.04 Polyethylene glycol (M01. wt. 300) 6.08 Sodium nitrite 0.02 Total 100.00

Properties:

Reflux boiling point (dry) at atmospheric pressure Reflux boiling point (wet) at atmospheric pressure of 3.5 parts by volume of water and 100 parts by volume of fluid of Example 9 385F.

Viscosity 40F. 1470 cs.

212F. 2.64 cs. Water Tolerance Test Passed water tolerance test at 40F. and 140F. according to procedure of SAE J70c.

Borate Ester D employed in the above fluid, which is an example of a Type IV ester, was prepared in the following manner: One mole (61.8 grams) of orthoboric acid was added to a solution of one mole- (164 grams) of triethylene glycol monomethyl ether and 50 ml. of toluene. The mixture was heated to the boiling point and one mole (18 ml.) of water was removed as the azeotrope with toluene. The solution was cooled slightly below the boiling point and one mole (134 grams) of diethylene glycol monoethyl ether was added. Heating was resumed until another mole (18 ml.) of water was removed from the reaction mixture. Again the solution was cooled below the boiling point and one mole (120 grams) of diethylene glycol monomethyl ether was added. The solution was heated to boiling and a third mole (18 ml.) of water was removed following which the toluene remaining in the reaction mixture was removed to yield a tri borate ester of the fonnula:

The reflux boiling pint (dry) of the ester was 610F. at atmospheric pressure and it exhibited a viscosity of 775 cs. at 40F.

Percent B Analysis:

Calculated: 2.58 Found: 2.83

EXAMPLE 10 Percent by Weight Borate Ester E (Described below) 29.18 [CH,,(OCH,CH,),O] -,-B 55.48 Triethylene glycol monomethyl ethe 1 l .90 Diethanolamine 0.91 Polyethylene glycol (Mol. wt. 300 2.52 Sodium nitrite 0.01 Total 100.00

Properties:

Reflux boiling point (dry) at atmospheric pressure Reflux boiling point (wet) at atmospheric pressure of 3.5 parts by volume of water and 100 parts by volume of fluid of Example 383F.

Viscosity 40F. 2380 cs.

212F. 3.38 cs. Water Tolerance Test Passed water tolerance test at 40F. and 140F. ac-

cording to procedure of SAE .l70c.

Borate Ester E employed in the above fluid composition, which is a Type 111 borate ester, was prepared as follows: One mole (354 grams) of a random addition product of ethylene oxide and propylene oxide with butyl alcohol, prepared by reaction a mixture containing weight percent ethylene oxide and 50 weight percent propylene oxide with the alcohol, and ml. of toluene were mixed with one-third mole (20 grams) of orthoboric acid. The mixture was heated to its boiling point and one mole (18 ml.) of water was removed as the azeotrope with toluene after which the toluene remaining in the reaction mixture was removed under vacuum. The resulting tris borate ester (Borate Ester E) was clear, water-white liquid having a reflux boiling point (dry) of approximately 625 30F.

EXAMPLE 1 1 Percent by Weight IQ A C z Ofih- Triethylene glycol monoethyl ether l2.78 Methyldiethanolamine 2.20 Polyethylene glycol (Mol. wt. 300) 5.00 Diisopropyl ammonium nitrite 0.02 Total 100.00

EXAMPLE 12 Percent by Weight [C H,(OCH,CH,),O],-B 70.30 Trlethylene glycol monomethyl ether 19.95 'Diethanolamine 1.85 Polyethylene glycol (Mol. wt. 300) 7.85 Di(2-ethylhexyl) ammonium nitrite 0.05 Total 100.00

EXAMPLE 13 Percent by Weight [C H,(OCH,CH9)1O],-B 66.00 Tnethylene glycol monomethyl ether 25.90 Diethanolamine 1.85 Polyethylene glycol (Mol. wt. 300) 6.00 Benzotriazole 0.25 Total 100.00

EXAMPLE 14 Percent by Weight [C ,H (0CH CH,),O] -B 80.00 Tnethylene glycol monoethyl ether 15.0 Polyethylene glycol (Mol. wt. 300) 5.0 Total 100.00

EXAMPLE 15 Percent by Wei ht [C H,(OCH,CH,) O] -,-B g 67.40 Tr iethylene glycol monomethyl ether 25.81 Diethanolamine 1.711 Polyethylene glycol (Mol. wt. 300) 5.00 Sodium Nitrite 0.01 Total 100.00

E X A M PL E 1 6 Percent by Wei ht CH (0CH,CHz)a0];-B g 75.00 Trlethylene glycol monomethyl ether 6.20 Tetraethylene glycol monoethyl ether 17.00 Diethanolamine 1.68 Sodium Nitrite 0.02 Tolutriazole 0.10 Total 100.00

is shown below:

Properties of Water lnsensitive Brake Fluid of Example LE 21 Percent by Weight a( 2)a ]s- 75.00 rttethylletie glytiol nltonomethyg1 etherI l 1.25 e rae y ene g yco monome et er 12.00 Test Diethyl amino ethoxyethanol 1.75 Test SAEJ I702 Results 100110 EXAMPLE 22 Reflux boiling point (dry) 374F. min. 532F. 1O 513th point 2 2 7 9.61 min. 320%. mfg: by

iscosity at 1 F. cs. min. 2.5 cs. [CH (OCH CH Q] .B 7090 Viscosity at 40F. 1800 cs. max. 1530 cs. Trietfhylene glyol monomethyl ether 13.25 7.0 to l 1.5 7.5 Tetraethylene glycol monomethyl ether 15.00 Evaporatton loss 80 percent max., 62 percent biejhyl gghgnglamine 1 .75 M Total 100.00 EXAMPLE 17 EXAMPLE 23 Percent by Weight Percent by [Cl-l,(OCH,Cl-l,),O],-B 70.00 Weight Tetraethylene glycol monoethyl ether 21 .00 '[CH,(OCH,CH,),O],-B 72.00 Triethylene glycol monomethyl ether 7.20 Triethylene glycol monoethyl ether 16.25 Diethanolamine 1.68 Tetraethylene glycol monoethyl ether 10.00 Tolutriazole 0. l 0 Hydroxyethyl hydrazine 1 ,75 Sodium Nitrite 1 Total 100.00

Total EXAMPLE 24 Reflux boilin oint dr at atmos heric ressure o g p y) p p 25. Percent by 528 F. weigh! V|scos1ty at 40F. 1447 cs. a( :)a l J'B 66. p 7 3 :lr etgylene glycol monoethyl elthel: 5.00 net yenegyco monomet y et er 17.00 EXAMPLE 8 'lgetraethylene gllylgcol monomethyl ether 10.00 let y aminoe anol 2.00 Total 100.00 Percent by Weight EXAMPLE 25 ICH,(OCH,CHi),OI]=,-B m i u Tetraethylene g yco monoe y e er Triethylene glycol monomethyl ether 522m by Diethanolamine l. CH B 73 0O Dietl tylene glycttl mo noethyl ether 5.00 Sodmm f m1 loo-00 Triethylene glycol monomethyl ether 10.00 0 Tetraethylene glycol monomethyl ether 10.00 I Dtmethyl amino ethoxyethanol 2.00 Reflux boiling point (dry) at atmospheric pressure 528F.

EXAMPLE 26- viscosity at 40F. 1552 cs. pH 7,35 Percent by [CH (OCH CH )0] B weight 73.20 EXAMPLE Trieihylenglyol monomethyl ether 10.00 Percent y Eetrgethylene glycol monomethyl ether 15.00 let ano amine v v 1.78 Weight cH, 0cH,cH, ,01,-B 66.00 f 885 Tetraethylenel glyfol monoettgtygl etter Triethylenegyco monome y et er Diethanolarnine 1.68 EXAMPLE 27 Tolutriazole 0. l 0 Sodium Nitrite 0.02 Percent by Total 100.00 Weight [CH,(OCH,CH2)=O] -B 75.00 Triethylene glycol monomethyl ether 6.00 Reflux botlmg pomt (dry) at atmospheric pressure Triethylene glycol monoethyl ether 7.00 o Tetraethylene glycol monoethyl ether 10.00 526 o Hydroxyethyl hydrazine 1.90 VlSCOSlty at F. CS. Tohn iazole 0 |0 pH 7.5 Total 100.00

EXAMPLE 20 EXAMPLE 28 Percent by Percent by Weight Weight ICH,(OCH,CH,),OI J 75.00 ICHAQCHICHQIOII'B Tetraethylene glycol monoethyl ether 23.20 Tnethylene glycol monomflhyl ether Diethanoamine L68 gtiatt'zethyilcne glycol monomethyl ether 1' 1 t .01 0.10 1 s d i u lit l lit rite 0.02 8'8;

T t l .00

a Total 100.00 Reflux boiling point (dry) at atmospheric pressure EXAMPLE 29 535F.

Viscosity at -40F. 1663 Pe F by Weight 1 1(OCH;C )a ]r Triethylene glycol monomethyl ether Triethylene glycol monoethyl ether Tetraethylene glycol monoethyl ether Hydroxyethyl hydrazine Tolutriazole Total EXAMPLE 30 2 5( z z): ]3' Triethylene glycol monomethyl ether Triethylene glycol monoethyl ether Tetraethylene glycol monoethyl ether Hydroxyethyl hydrazine Tolutriazole Total EXAMPLE 31 Tripropylene glycol dimethyl ether Nethyl morpholine Polyethylene glycol (Mol. wt. 250) Total EXAMPLE 32 Triethylene glycol monoethyl ether Triethylene glycol monomethyl ether Mixed isopropanolamines (-1 5% mono,

40-50% di, 4050% tri) Glycerin Butynediol Dioctyl diphenylamine Sodium nitrite Total Properties:

Reflux boiling point (dry) Reflux boiling point (wet) (3.5 ml. water 100 ml. fluid) Viscosity at 40F.

EXAMPLE 33 2 5( z z):i ]a' z s( 2)4 ]a' Triethylene glycol monoethyl ether Diethylene glycol monomethyl ether Mixed isopropanolamines (IO-% mono, 40-50% di, 40-50% tri) Glycerin Butynediol Dioctyl diphenylamine Sodium nitrite Total Properties:

Reflux boiling point (dry) Reflux boiling point (wet) (3.5 ml. water +100 ml. fluid) Viscosity at 40F.

EXAMPLE 34 Triethylene glycol monoethyl ether Diethylene glycol monoethyl ether Mixed isopropanolamines (IO-15% mono,

40-60% tri) Glycerin Butynediol Dioctyl diphenylamine Sodium nitrite Percent by Weight Percent by Weight Percent by Weight Percent by Weight Percent by Weight 343F. 1961 cs.

342F. 1542 cs.

Properties:

Reflux boiling point (dry) Reflux boiling point (wet) (3.5 ml. water +100 ml. fluid) Viscosity at -40F.

EXAMPLE 3 5 Properties: 0

25 EXAMPLE 36 [CH3(OCH2CH!)30]3'B Tetraethylene glycol monoethyl ether Triethylene glycol monomethyl ether Monoethanolamine Benzotriazole Diisopropanolamine nitrite Total Properties:

Reflux boiling point (dry) Reflux boiling point (wet) (3.5 ml. water 100 ml. fluid) Viscosity at F.

40 EXAMPLE 37 1 2 2):1 ]a' Tetraethylene glycol monoethyl ether Triethylene glycol monomethyl ether Monoethanolamine Benzotriazole Diisopropanolamine nitrite Total Properties:

Reflux boiling point (dry) Reflux boiling point (wet) (3.5 ml. water+100 ml. fluid) Viscosity at -40F.

EXAMPLE 38 a( z z):| ]:r Tetraethylene glycol monoethyl ether Triethylene glycol monomethyl ether Monoethanolamine Benzotriazole Diisopropanolamine nitrite Total 5 Properties:

Reflux boiling point (dry) Reflux boiling point (wet) (3.5 ml. water+ ml. fluid) Viscosity at 40F.

Percent by Weight Percent by Weight Percent by Weight Percent by Weight 323F. 373 cs.

334F. 1585 cs.

340F. 584 cs.

332F. 456 cs.

EXAMPLE 39 Mixed isopropanolamine (lo-45% mono,

40-50% di. 40-50% tri) Glycerin Butynediol Dioctyl diphenylamine( Van Lube 81 produced by R.T.Vanderbilt Co.) Sodium nitrite Total Properties:

EXAMPLE 40 Triethylene Glycol monomethyl ether Diethanolamine Polyethylene glycol (M.W. 300) Sodium nitrite Total Properties:

Reflux boiling point (dry) Reflux boiling point (wet) (3.5 ml. water 100ml. fluid) EXAMPLE 41 Triethylene glycol monomethyl ether Diethanolamine Polyethylene glycol (M.W. 300) Sodium nitrite Total Properties:

Reflux boiling point (dry) Reflux boiling point (wet) (3.5 ml; water +100 ml. fluid) EXAMPLE 42 Triethylene glycol monomethyl ether Diethanolamine Polyethylene glycol (M.W. 300) Sodium nitrite Total Properties:

Reflux boiling point (dry) Reflux boiling poin t(wet) (3.5 ml. water+ 100 ml. fluid) EXAMPLE 43 Percent by Weight Percent by Weight Percent by Weight Percent by Weight 373F. 2453 cs.

A hydraulic fluid having the following composition was prepared:

Percent by Weight lsoctanol 2 Monoethanolamine Total cos Properties:

Reflux boiling point (dry) 463F. Reflux boiling point (wet) (3.5 ml. water ml. fluid) Viscosity at -40F.

310F. 816 cs.

EXAMPLE 44 A hydraulic fluid having the following composition was prepared:

Percent by Weight [CH,(OCH,CH,);,O],,-B 79.0 Hexylene glycol 20.0 Monoethanolamine 1.0 Total 100.0

Properties:

Reflux boiling point (dry) 489F. Reflux boiling point (wet) (3.5 ml. water +100 ml. fluid) 343F. Viscosity at 40F.

EXAMPLE 45 A hydraulic fluid having the following composition was prepared:

What is claimed is:

l. A hydraulic fluid composition consisting essentially of (A) from about 20 to about 54.4 percent by weight, based on the total weight of the hydraulic fluid composition of at least one base fluid or lubricant selected from the group consisting of (a) a borate ester of the formula:

wherein R, is alkyl of from one to four carbon atoms, R, is alkylene of from two to four carbon atoms and y is an integer of from two to four; (b) a borate ester of the formula:

wherein R, is alkyl of from one to four carbon atoms, R and R are independently selected from the group consisting of hydrogen and methyl, m and n are positive integers whose sum is from 2 to 20, and with the proviso that one of R and R is methyl and one of R, and R is hydrogen; (0) a borate ester of the formula:

wherein R, is alkyl of from one to four carbon atoms, Rg is a heteric oxyalkylene chain of the formula:

25 Z UQ 2 3),'I

wherein the sum of r and s is not more than 20 and wherein the weight percent of the oxyethylene units is not less than 20 based on the total weight of all the oxyalkylene units; and (d) a borate ester of the formula:

wherein T,, T, and T are each an independently selected alkyl group having from one to four carbon atoms; R R R R R and R are independently selected from the group consisting of hydrogen and methyl, n and m are positive integers independently selected in each chain and whose sum in each chain is from 2 to 20, and with the proviso that in no more than two of the chains is the sum of n and m the same; and the remainder of the hydraulic fluid composition comprising: (B) from 0 to about 80 percent by weight, based on the total weight'of the fluid composition, of at least one diluent selected from the group consisting of: (i) glycol ethers having the formula:

wherein R is alkyl of from one to four carbon atoms, R is selected from the group consisting of hydrogen and alkyl of from one to four carbon atoms, R" is alkylene of from two to four'carbon atoms and y is an integer of from 2 to 4; (ii) glycols and polyglycols having a molecular weight of from about 60 to about 450 and (iii) aliphatic saturated, monohydric alcohols having from six to 13 carbon atoms.

'2. A hydraulic fluid composition consisting essentially of (A) from about 20 to about 54.4. percent by weight, based on the total weight of the hydraulic fluid composition of at least one base fluid or lubricant selected from the group consisting of (a) a borate ester of the formula:

wherein R, is alkyl of from one to four carbon atoms, R,, is alkylene of from two to four carbon atoms and y is an integer of from 2to 4; (b) a borate ester of the formula:

wherein R, is alkyl of from one to four carbon atoms, R and R are independently selected from the group consisting of hydrogen and methyl, m and'n are positive integers whose sum is from 2 to 20, and with the proviso that one of R and R is methyl and one of R and R is hydrogen; (0) a borate ester of the formula:

wherein T,, T and T are each an independently selected alkyl group having from one to four carbon atoms; R R R R-,, R and R are independently selected from the group consisting of hydrogen and methyl, n andm are positive integers independently selectedin each chain and whose sum in each chain is from 2 to 20, and with the proviso that in no more than two of the chains is the sum of n and m the same; and the remainder of the hydraulic fluid composition comprising: (B) from 0 to about percent by weight, based on the total weight of the fluid composition, of at least one diluent selected from the group consisting of: (i) glycol ethers having the formula:

wherein R is alkyl of from one to four carbon atoms, R' is selected from the group consisting of hydrogen and alkyl of from one to four carbon atoms, R is alkylene of from two to four carbon atoms and y is an integer of from 2 to 4; (ii) glycols and polyglycols having a molecular weight of from about 60 to about 450 and (iii) aliphatic saturated, monohydric alcohols having from six to 13 carbon atoms and (C) from 0 to about 10.0 percent by weight, based on the total weight of the hydraulic fluid, of at least one inhibitor for pH and corrosion control.

3'. A hydraulic fluid composition consisting essentially of (A) from about 20 to about 54.4 percent by weight, based on the total weight of the hydraulic fluid composition of at least one base fluid or lubricant selected from the group consisting of (a) a borate ester of the formula:

wherein R, is alkyl of from one to four carbon atoms, R,, is alkylene of from two to four carbon atoms and y is an integer of from 2 to 4; (b) a borate ester of the formula:

wherein R, is alkyl of from one to four carbon atoms, R and R are independently selected from the group consisting of hydrogen and methyl, m and n are positive integers whose sum is from 2 to 20, and with the proviso that one of R and R is methyl and one of R and R is hydrogen; (c) a borate ester of the formula: 1[ g] )rwherein R, is alkyl of from one to four carbon atoms, Rg is a heteric oxyalkylene chain of the formula:

wherein the sum of r and s is not more than 20 and wherein the weight percent of the oxyethylenc units in not less than 20 based on the total weight of all the oxyalkylene units; and (d) a borate ester of the for-mula:

/O(RtCHCHa0) (R CHCHgO) T B-O(RQCHCHQO)n(R1CHCHzO)mT2 \O(RQCHCILO),,(R OHCH2O)mTs wherein T,, T and T are each an independently selected alkyl group having from one to four carbon atoms; R,, R R R R and R are independently selected from the group consisting of hydrogen and methyl, n and m are positive integers independently selected in each chain and whose sum in each chain is from 2 to 20, and with the proviso that in no more than two of the chains is the sum of n and m the same; and

the remainder of the hydraulic fluid composition comprising: (B) from to about 80 percent by weight, based on the total weight of the fluid composition, of at least one diluent selected from the group consisting of: (i) glycol ethers having the formula:

' "Rio-R"1,oR',

wherein R is alkyl of from one to four carbon atoms, R is selected from the group consisting of hydrogen and alkyl of from one to four carbon atoms, R" is alkylene of from 2 to 4 carbon atoms and y is an integer of from 2 to 4; (ii) glycols and polyglycols having a molecular weight of from about 60 to about 450 and (iii) aliphatic saturated, monohydric alcohols having from six to 13 carbon atoms and (C) from 0 to about 10.0 percent by weight, based on the total weight of the hydraulic fluid, of at least one antioxidant.

4. A hydraulic fluid composition consisting essentially of (A) from about 20 to about 54.4 percent by weight, based on the total weight of the hydraulic fluid composition of at least one base fluid or lubricant selected from the group consisting of (a) a borate ester of the formula wherein R is alkyl of from one to four carbon atoms, R, is alkylene of from two to four carbon atoms and y is an integer of from 2 to 4; (b) a borate ester of the fortm laa [R (OCH' CHR ),,,--(OCH CHR ),,O] B

wherein R is alkyl of from one to four carbon atoms, R and R are independently selected from the group consisting of hydrogen and methyl, m and n are positive integers whose sum is from 2 to 20, and with the proviso that one of R and R is methyl and one of R and R is hydrogen; (c) a borate ester of the formula:

( 1l gl )3' wherein R is alkyl of from one to four carbon atoms, Rg is a heteric oxyalkylene chain of the formula:

the remainder of the hydraulic fluid composition comprising: (B) from 0 to about 80 percent by weight, based on the total weight of the fluid composition, of at least one diluent selected from the group consisting of: (i) glycol ethers having the formula:

1 wherein R is alkyl of from one to four carbon atoms, R is selected from the group consisting of hydrogen and alkyl of from one to four carbon atoms, R" is alkylene of from two to four carbon atoms and y is an integer of from 2 to 4; (ii) glycols and polyglycols having a molecular weight of from about 60 to about 450 and (iii) aliphatic saturated, monohydric alcohols having from six to 13 carbon atoms and (C) from 0 to about 10.0 percent by weight, based on the total weight of the hydraulic fluid, of at least one rust inhibitor.

5. A hydraulic fluid composition consisting essentially of (A) from about 20 to about 54.4 percent by weight, based on the total weight of the hydraulic fluid composition of at least one base fluid or lubricant selected from the group consisting of (a) a borate ester of the formula:

wherein R is alkyl of from one to four carbon atoms, R, is alkylene of from two to four carbon atoms and y is an integer of from 2 to 4; (b) a borate ester of the formula:

"""(RllR ioia ia wherein R is alkyl of from one to four carbon atoms.

Rg is a heteric oxyalkylene chain of the formula:

wherein T T and T are each in independently selected alkyl group having from one to four carbon atoms; R R R R R and R are independently selected from the group consisting of hydrogen and wherein R is alkyl of from one to four carbon atoms, R is selected from the group consisting of hydrogen and alkyl of from one tofour carbon atoms, R is alkylene of from two to four carbon atoms and y is an integer of from 2 to 4; (ii) glycols and polyglycols having a molecular weight of from about 60 to about 450 and (iii) aliphatic saturated, monohydric alcohols having methyl, n and m are positive integers independently,

from six to 13 carbon atoms and (C) from O to about l0.0 percent by weight, based on the total weight of the hydraulic fluid, of at least one viscosity index improver.

6. A hydraulic fluid composition consisting essentially of (A) from about 20 to about 54.4 percent by weight, based on the total weight of the hydraulic fluid composition of at least one base fluid or lubricant selected from the group consisting of (a) a borate ester ofthe formula:

wherein R, is alkyl of from one to four carbon atoms, R and R are independently selected from the group consisting of hydrogen and methyl, m and n are positive integers whose sum is from 2 to 20, and with the proviso that one of R and R is methyl and one of R and R is hydrogen; a borate ester of the formula:

wherein the sum of r and s is not more than and wherein the weight percent of the oxyethylene units is not less than 20 based on the total weight of all the oxyalkylene units; and (d) a borate ester of the formula:

Omassage)ma mas, B-O(RQGHCH2O) (R1CHCH2O)mT2 \O(RsCHCHzOM-(R CHCHQOMT;

wherein T,, T and T are each an independently selected alkyl group having from one to four carbon atoms; R,, R R R R and R are independently selected from the group consisting of hydrogen and wherein R is alkyl of from one to four carbon atoms, R is selected from the group consisting of hydrogen and alkyl of from one to four carbon atoms, R" is alkylene of from two to four carbon atoms and y is an integer of from 2 to 4; (ii) glycols and polyglycols having a molecular weight of from about 60 to about 450 and (iii) aliphatic saturated, monohydric alcohols having from six to 13 carbon atoms and (C) from 0 to about 10.0 percent by weight, based on the total weight of the hydraulic fluid, of at least one pour point depressant.

7. A hydraulic fluid composition consisting essen tially of (A) from about 20 to about 54.4 percent by weight, based on the total weight of the hydraulic fluid composition of at least one base fluid or lubricant selected from the group consisting of (a) a borate ester of the formula:

wherein R, is alkyl of from one to four carbon atoms, R and R are independently selected from the group consisting of hydrogen and methyl, m and n are positive integers whose sum is from 2 to 20, and with the proviso that one of R and R is methyl and one of R and R is hydrogen; (c) a borate ester of the formula:

o(aiottcmo)wmtcaoalo r, B-0(R0011oHi0)n(R1oHoH10)mT, \0(R8CHCH20)n(R9CHCH20)mT3 wherein T,, T and T are each an independently selected alkyl group having from one to four carbon atoms; R.,, R R R R and R are independently selected from the group consisting of hydrogen and methyl, n and m are positive integers independently selected in each chain and whose sum in each chain is from 2 to 20, and with the proviso that in no more than two of the chains is the sum of n and m the same; and the remainder of the hydraulic fluid composition comprising: (B) from 0 to about percent by weight, based on the total weight of the fluid composition, of at least one diluent selected from the group consisting of: (i) glycol ethers having the formula:

wherein R is alkyl of from one to four carbon atoms, R is selected from the group consisting of hydrogen and alkyl of from one to four carbon atoms, R" is alkylene of from two to four carbon atoms and y is an integer of from 2 to 4; (ii) glycols and polyglycols having a molecular weight of from about 60 to about 450 and (iii) aliphatic. saturated, monohydric alcohols having from six to 13 carbon atoms and (C) from 0 to about 10.0 percent by weight, based on the total weight of the hydraulic fluid, of at least one lubricity agent.

8. A hydraulic fluid composition consisting essentially of (A) from about 20 to about 54.4 percent by weight, based on the total weight of the hydraulic fluid composition of at least one base fluid or lubricant selected from the group consisting of (a) a borate ester of the formula:

- [R,(O-R,, ),,O],-B wherein R, is alkyl of from one to four carbon atoms, R, is alkylene of from two to four carbon atoms and y is an integer offrom 2 to 4; (b) a borate ester of the formula:

(OCH CH (OCH CHCHQ, wherein the sum ofr and s is not more than 20 and wherein the weight percent of the oxyethylene units is not less than 20 based on the total weight of all the oxyalkylene units; and (d) a borate ester of the formula:

wherein T,, T and T are each an independently selected alkyl group having from one to four carbon atoms; R,, R R R R and R are independently selected from the group consisting of hydrogen and methyl, n and m are positive integers independently selected in each chain and whose sum in each chain is from 2 to 20, and with the proviso that in no more than two of the chains is the sum of n and m the same; and the remainder of the hydraulic fluid composition comprising: (B) from 0 to about 80 percent by weight, based on the totalweight of the fluid composition, of at least one diluent selected from the group consisting of: (i) glycol ethers having the formula:

wherein R is alkyl of from one to four carbon atoms, R is selected from the group consisting of hydrogen and alkyl of from one to four carbon atoms, R" is alkylene of from two to four carbon atoms and y is an integer of from 2 to 4; (ii) glycols and polyglycols having a molecular weight of from about 60 to about 450 and (iii) aliphatic saturated, monohydric alcohols having from six to 13 carbon atoms and (C) from 0 to about 10.0 percent by weight, based on the total weight of the hydraulic fluid, of at least one dye.

9. The hydraulic fluid composition of claim 2 which contains from 0 to about 8.0 percent by weight of at least one said inhibitor for pH and corrosion control and from 0 to about 2.0 percent by weight of at least one antioxidant.

10. The hydraulic fluid composition of claim 2 wherein said base fluid or lubricant is at least one borate ester of type (a). I

11. The hydraulic fluid composition of claim wherein said diluentis of type (i).

12. The hydraulic fluid composition of claim 11 which contains from about 0.2 to about 6.0 percent by weight, based on the total weight of the hydraulic fluid, of at least one said inhibitor for pH and corrosion control.

13. The hydraulic fluid composition of claim 12 which contains from about 0.001 to about 1.0 percent by weight, based on the total weight of the hydraulic fluid, of at least one said antioxidant.

14. The hydraulic fluid composition of claim 2 wherein said base fluid or lubricant consists essentially of from about 30 to about 54.4 percent by weight, based on the total weight of the hydraulic fluid com position.

15. The hydraulic fluid composition of claim 14 wherein said base fluid or lubricant is at least one borate ester of type (a).

16. The hydraulic fluid composition of claim 15 wherein said borate ester of type (a) has an R, alkyl group of one to two carbon atoms and an R, alkylene group of2 to 3.

17. The hydraulic fluid composition of claim 15 wherein said borate ester of type (a) is selected from the group consisting of ICH,,(OCH CH O] -B, [C H,, CH O] -B, [C H (OCH CH O] B, 2 nr "2 2)4 ]3' 3 1( 2 2)3 ]3 4 a.l 2 2)2 ]3 v and 4 9( 2 2)s 01 -8.

18. The hydraulic fluid composition of claim 15 wherein said diluent is at least one glycol ether of type (i).

19. The hydraulic fluid composition of claim 18 wherein said glycol ether of type (i) has an alkyl R group of one to two carbon atoms, an R selected from the group consisting of hydrogen and alkyl of one to two carbon atoms and an alkylene R" group of from two to three carbon atoms.

20. The hydraulic fluid composition of claim 18 wherein said glycol ether is selected from the group consisting of diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether and tetraethylene glycol monobutyl ether.

21. The hydraulic fluid composition of claim 18 which contains from about 0.2 to about 6.0 percent by weight, based on the total weight of the hydraulic fluid of at least one inhibitor for pH and corrosion control.

22. The hydraulic fluid composition of claim 21 which contains from about 0.001 to about 1.0 percent by weight, based on the total weight of the hydraulic fluid, of at least one antioxidant.

23. In the operation of a fluid pressure operating device which uses hydraulic pressure transmission fluid, the improvement comprising using as said hydraulic pressure transmission fluid a composition consisting essentially of from about 20 to about 54.4 percent by weight, based on-the total weight of the hydraulic fluid composition, of at least one borate ester base fluid or lubricant selected from the group consisting of (a) a borate ester of the formula:

l( a) ]8 wherein R, is alkyl of from one to four carbon atoms, R, is alkylene of from two to four carbon atoms and y is an integer of from 2 to 4; (b) a borate ester of the formula:

[ z UT 2 3)s wherein the sum of r and s is not more than 20 and wherein the weight percent of the oxyethylene units is not less than 20 based on the total weight of all the oxyalkylene units; and (d) a borate ester of the formula:

/0(1ucuc1r2 ).,(luclrcmom' i 13-0(mencm0).,-(R10Hcm0)m'li \O(RBCIiC 20)n"'(RDCIICII20)mTS wherein T T and T are each an independently selected alkyl group having from one to four carbon atoms; R.,, R R R-,, R and R are independently selected from the group consisting of hydrogen and methyl, n and m are positive integers independently selected in each chain and whose sum in each chain is from 2 to 20, and with the proviso that in no more than two of the chains is the sum of n and m the same.

24. The process of claim 23 wherein there is from about 30 to about 54.4 percent by weight, based on the total weight of the hydraulic fluid composition, of said base fluid or lubricant.

25. The process of claim 24, wherein said base fluid or lubricant includes at least one borate ester of type (a).

Claims

2. A hydraulic fluid composition consisting essentially of (A) from about 20 to about 54.4 percent by weight, based on the total weight of the hydraulic fluid composition of at least one base fluid or lubricant selected from the group consisting of (a) a borate ester of the formula: (R1(O-Ra)y-O)3-B , wherein R1 is alkyl of from one to four carbon atoms, Ra is alkylene of from two to four carbon atoms and y is an integer of from 2 to 4; (b) a borate ester of the formula: (R1-(OCH2CHR2)m-(OCH2CHR3)nO)3-B , wherein R1 is alkyl of from one to four carbon atoms, R2 and R3 are independently selected from the group consisting of hydrogen and methyl, m and n are positive integers whose sum is from 2 to 20, and with the proviso that one of R2 and R3 is methyl and one of R2 and R3 is hydrogen; (c) a borate ester of the formula: (R1(Rg)O)3-B, wherein R1 is alkyl of from one to four carbon atoms, Rg is a heteric oxyalkylene chain of the formula: (- (OCH2CH2)r , (OCH2CHCH3)s -) , wherein the sum of r and s is not more than 20 and wherein the weight percent of the oxyethylene units is not less than 20 based on the total weight of all the oxyalkylene units; and (d) a borate ester of the formula:
3. A hydraulic fluid composition consisting essentially of (A) from about 20 to about 54.4 percent by weight, based on the total weight of the hydraulic fluid composition of at least one base fluid or lubricant selected from the group consisting of (a) a borate ester of the formula: (R1)O-Ra)y-O)3-B , wherein R1 is alkyl of from one to four carbon atoms, Ra is alkylene of from two to four carbon atoms and y is an integer of from 2 to 4; (b) a borate ester of the formula: (R1-(OCH2CHR2)m-(OCH2CHR3)nO)3-B , wherein R1 is alkyl of from one to four carbon atoms, R2 and R3 are independently selected from the group consisting of hydrogen and methyl, m and n are positive integers whose sum is from 2 to 20, and with the proviso that one of R2 and R3 is methyl and one of R2 and R3 is hydrogen; (c) a borate ester of the formula: (R1(Rg)O)3-B, wherein R1 is alkyl of from one to four carbon atoms, Rg is a heteric oxyalkylene chain of the formula:(- (OCH2CH2)r , (OCH2CHCH3)s -) , wherein the sum of r and s is not more than 20 and wherein the weight percent of the oxyethylene units in not less than 20 based on the total weight of all the oxyalkylene units; and (d) a borate ester of the formula:
4. A hydraulic fluid composition consisting essentially of (A) from about 20 to about 54.4 percent by weight, based on the total weight of the hydraulic fluid composition of at least one base fluid or lubricant selected from the group consisting of (a) a borate ester of the formula: (R1(O-Ra)y-O)3-B , wherein R1 is alkyl of from one to four carbon atoms, Ra is alkylene of from two to four carbon atoms and y is an integer of from 2 to 4; (b) a borate ester of the formula: (R1-(OCH2CHR2)m-(OCH2CHR3)nO)3-B , wherein R1 is alkyl of from one to four carbon atoms, R2 and R3 are independently selected from the group consisting of hydrogen and methyl, m and n are positive integers whose sum is from 2 to 20, and with the proviso that one of R2 and R3 is methyl and one of R2 and R3 is hydrogen; (c) a borate ester of the formula: (R1(Rg)O)3-B, wherein R1 is alkyl of from one to four carbon atoms, Rg is a heteric oxyalkylene chain of the formula:(- (OCH2CH2)r , (OCH2CHCH3)s -) , wherein the sum of r and s is not more than 20 and wherein the weight percent of the oxyethylene units is not less than 20 based on the total weight of all the oxyalkylene units; and (d) a borate ester of the formula:
5. A hydraulic fluid composition consisting essentially of (A) from about 20 to about 54.4 percent by weight, based on the total weight of the hydraulic fluid composition of at least one base fluid or lubricant selected from the group consisting of (a) a borate ester of the formula:(R1(O-Ra)y-O)3-B , wherein R1 is alkyl of from one to four carbon atoms, Ra is alkylene of from two to four carbon atoms and y is an integer of from 2 to 4; (b) a borate ester of the formula: (R1-(OCH2CHR2)m-(OCH2CHR3)nO)3-B , wherein R1 is alkyl of from one to four carbon atoms, R2 and R3 are independently selected from the group consisting of hydrogen and methyl, m and n are positive integers whose sum is from 2 to 20, and with the proviso that one of R2 and R3 is methyl and one of R2 and R3 is hydrogen; (c) a borate ester of the formula: (R1(Rg)O)3-B, wherein R1 is alkyl of from one to four carbon atoms, Rg is a heteric oxyalkylene chain of the formula:(-(OCH2CH2)r , (OCH2CHCH3)s -) , wherein the sum of r and s is not more than 20 and wherein the weight percent of the oxyethylene units is not less than 20 based on the total weight of all the oxyalkylene units; and (d) a borate ester of the formula:
6. A hydraulic fluid composition consisting essentially of (A) from about 20 to about 54.4 percent by weight, based on the total weight of the hydraulic fluid composition of at least one base fluid or lubricant selected from the group consisting of (a) a borate ester of the formula: (R1(O-Ra)y-O)3-B , wherein R1 is alkyl of from one to four carbon atoms, Ra is alkylene of from two to four carbon atoms and y is an integer of from 2 to 4; (b) a borate ester of the formula: (R1-(OCH2CHR2)m-(OCH2CHR3)nO)3-B , wherein R1 is alkyl of from one to four carbon atoms, R2 and R3 are independently selected from the group consisting of hydrogen and methyl, m and n are positive integers whose sum is from 2 to 20, and with the proviso that one of R2 and R3 is methyl and one of R2 and R3 is hydrogen; (c) a borate ester of the formula: (R1(Rg)O)3-B, wherein R1 is alkyl of from one to four carbon atoms, Rg is a heteric oxyalkylene chain of the formula: (- (OCH2CH2)r , (OCH2CHCH3)s -) , wherein the sum of r and s is not more than 20 and wherein the weight percent of the oxyethylene units is not less than 20 based on the total weight of all the oxyalkylene units; and (d) a borate ester of the formula:
7. A hydraulic fluid composition consisting essentially of (A) from about 20 to about 54.4 percent by weight, based on the total weight of the hydraulic fluid composition of at least one base fluid or lubricant selected from the group consisting of (a) a borate ester of the formula: (R1(O-Ra)y-O)3-B , wherein R1 is alkyl of from one to four carbon atoms, Ra is alkylene of from two to four carbon atoms and y is an integer of from 2 to 4; (b) a borate ester of the formula: (R1-(OCH2CHR2)m-(OCH2CHR3)nO)3-B , wherein R1 is alkyl of from one to four carbon atoms, R2 and R3 are independently selected from the group consisting of hydrogen and methyl, m and n are positive integers whose sum is from 2 to 20, and with the proviso that one of R2 and R3 is methyl and one of R2 and R3 is hydrogen; (c) a borate ester of the formula: (R1(Rg)O)3-B, wherein R1 is alkyl of from one to four carbon atoms, Rg is a heteric oxyalkylene chain of the formula: (- (OCH2CH2)r , (OCH2CHCH3)s -) , wherein the sum of r and s is not more than 20 and wherein the weight percent of the oxyethylene units is not less than 20 based on the total weight of all the oxyalkylene units; and (d) a borate ester of the formula:
8. A hydraulic fluid composition consisting essentially of (A) from about 20 to about 54.4 percent by weight, based on the total weight of the hydraulic fluid composition of at least one base fluid or lubricant selected from the group consisting of (a) a borate ester of the formula: (R1(O-Ra)y-O)3-B , wherein R1 is alkyl of from one to four carbon atoms, Ra is alkylene of from two to four carbon atoms and y is an integer of from 2 to 4; (b) a borate ester of the formula: (R1-(OCH2CHR2)m-(OCH2CHR3)nO)3-B , wherein R1 is alkyl of from one to four carbon atoms, R2 and R3 are independently selected from the group consisting of hydrogen and methyl, m and n are positive integers whose sum is from 2 to 20, and with the proviso that one of R2 and R3 is methyl and one of R2 and R3 is hydrogen; (c) a borate ester of the formula: (R1(Rg)O)3-B, wherein R1 is alkyl of from one to four carbon atoms, Rg is a heteric oxyalkylene chain of the formula: (- (OCH2CH2)r , (OCH2CHCH3)s -) , wherein the sum of r and s is not more than 20 and wherein the weight percent of the oxyethylene units is not less than 20 based on the total weight of all the oxyalkylene units; and (d) a borate ester of the formula:
9. The hydraulic fluid composition of claim 2 which contains from 0 to about 8.0 percent by weight of at least one said inhibitor for pH and corrosion control and from 0 to about 2.0 percent by weight of at least one antioxidant.
10. The hydraulic fluid composition of claim 2 wherein said base fluid or lubricant is at least one borate ester of type (a).
11. The hydraulic fluid composition of claim 10 wherein said diluent is of type (i).
12. The hydraulic fluid composition of claim 11 which contains from about 0.2 to about 6.0 percent by weight, based on the total weight of the hydraulic fluid, of at least one said inhibitor for pH and corrosion control.
13. The hydraulic fluid composition of claim 12 which contains from about 0.001 to about 1.0 percent by weight, based on the total weight of the hydraulic fluid, of at least one said antioxidant.
14. The hydraulic fluid composition of claim 2 wherein said base fluid or lubricant consists essentially of from about 30 to about 54.4 percent by weight, based on the total weight of the hydraulic fluid composition.
15. The hydraulic fluid composition of claim 14 wherein said base fluid or lubricant is at least one borate ester of type (a).
16. The hydraulic fluid composition of claim 15 wherein said borate ester of type (a) has an R1 alkyl group of one to two carbon atoms and an Ra alkylene group of 2 to 3.
17. The hydraulic fluid composition of claim 15 wherein said borate ester of type (a) is selected from the group consisting of (CH3(OCH2CH2)3O)3-B, (C2H5(OCH2CH2)2O)3-B, (C2H5(OCH2CH2)3O)3-B, (C2H5(OCH2CH2)4O)3-B, (C3H7(OCH2CH2)3O)3-B, (C4H9(OCH2CH2)2O)3-B, and (C4H9(OCH2CH2)3O)3-B.
18. The hydraulic fluid composition of claim 15 wherein said diluent is at least one glycol ether of type (i).
19. The hydraulic fluid composition of claim 18 wherein said glycol ether of type (i) has an alkyl R group of one to two carbon atoms, an R'' selected from the group consisting of hydrogen and alkyl of one to two carbon atoms and an alkylene R'''' group of from two to three carbon atoms.
20. The hydraulic fluid composition of claim 18 wherein said glycol ether is selected from the group consisting of diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether and tetraethylene glycol monobutyl ether.
21. The hydraulic fluid composition of claim 18 which contains from about 0.2 to about 6.0 percent by weight, based on the total weight of the hydraulic fluid of at least one inhibitor for pH and corrosion control.
22. The hydraulic fluid composition of claim 21 which contains from about 0.001 to about 1.0 percent by weight, based on the total weight of the hydraulic fluid, of at least one antioxidant.
23. In the operation of a fluid pressure operating device which uses hydraulic pressure transmission fluid, the improvement comprising using as said hydraulic pressure transmission fluid a composition consisting essentially of from about 20 to about 54.4 percent by weight, based on the total weight of the hydraulic fluid composition, of at least one borate ester base fluid or lubricant selected from the group consisting of (a) a borate ester of the formula: (R1(O-Ra)y-O)3-B , wherein R1 is alkyl of from one to four carbon atoms, Ra is alkylene of from two to four carbon atoms and y is an integer of from 2 to 4; (b) a borate ester of the formula: (R1-(OCH2CHR2)m-(OCH2CHR3)nO)3-B , wherein R1 is alkyl of from one to four carbon atoms, R2 and R3 are independently selected from the group consisting of hydrogen and methyl, m and n are positive integers whose sum is from 2 to 20, and with the proviso that one of R2 and R3 is methyl and one of R2 and R3 is hydrogen; (c) a borate ester of the formula: (R1(Rg)O)3-B , wherein R1 is alkyl of from one to four carbon atoms, Rg is a heteric oxyalkylene chain of the formula: (- (OCH2CH2)r , (OCH2CHCH3)s -) wherein the sum of r and s is not more than 20 and wherein the weight percent of the oxyethylene units is not less than 20 based on the total weight of all the oxyalkylene units; and (d) a borate ester of the formula:
24. The process of claim 23 wherein there is from about 30 to about 54.4 percent by weight, based on the total weight of the hydraulic fluid composition, of said base fluid or lubricant.
25. The process of claim 24, wherein said base fluid or lubricant includes at least one borate ester of type (a).