CA1190540A - Method for reducing brake noise in oil-immersed disc brakes - Google Patents
Method for reducing brake noise in oil-immersed disc brakesInfo
- Publication number
- CA1190540A CA1190540A CA000409208A CA409208A CA1190540A CA 1190540 A CA1190540 A CA 1190540A CA 000409208 A CA000409208 A CA 000409208A CA 409208 A CA409208 A CA 409208A CA 1190540 A CA1190540 A CA 1190540A
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- CA
- Canada
- Prior art keywords
- glycerol
- borated
- fatty acid
- oil
- acid ester
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Classifications
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
- C10M139/00—Lubricating compositions characterised by the additive being an organic non-macromolecular compound containing atoms of elements not provided for in groups C10M127/00 - C10M137/00
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
- C10M2227/00—Organic non-macromolecular compounds containing atoms of elements not provided for in groups C10M2203/00, C10M2207/00, C10M2211/00, C10M2215/00, C10M2219/00 or C10M2223/00 as ingredients in lubricant compositions
- C10M2227/06—Organic compounds derived from inorganic acids or metal salts
- C10M2227/061—Esters derived from boron
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- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Organic Chemistry (AREA)
- Lubricants (AREA)
- Braking Arrangements (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
METHOD FOR REDUCING BRAKE NOISE
IN OIL-IMMERSED DISC BRAKES
Lubricating oils containing borated fatty acid esters of glycerol have been found to reduce brake noise for oil-immersed disc brakes.
METHOD FOR REDUCING BRAKE NOISE
IN OIL-IMMERSED DISC BRAKES
Lubricating oils containing borated fatty acid esters of glycerol have been found to reduce brake noise for oil-immersed disc brakes.
Description
METHOD FOR REDUCING BRAKE NOISE
IN OIL-IMMERSED DISC BRAKES
FIELD OF THE INVENTION
This invention relates to lubricating oll com-positions, particularly to lubricating oil compositions useful as functional fluids in systems requiring coupling, hydraulic fluids and/or lubrication of relatively moving parts. ~ore particularly, it is concerned with functional fluids for use in the lubrication of heavy machinery, particularly high-power-output tractors r and to the reduc-tion of brake chatter therein.
DESCRIPTION OF THE PRIOR ART
The use of heavy machinery, such as a tractor, has increased the demand for high-performance lubricating compositions. Modern tractors have many power-assisted components, such as power steering and power brakes.
Power brakes are preferably of the disc type since they have greater braking capacityO The preferred disc brakes are the wet-type brake, which are immersed in a lubricant and are therefore isolated from dirt and grime~
Such brakes suffer from at least one problem, namely, brake chatter or brake squawk. This phenomenon is a very unpleasant noise that occurs upon application of the brake. In the past, friction-modifying agents, such - as dioleylhydrogen phosphite, have been added to the brake lubricating composition to reduce the chatter. Lubricat-ing compositions containing this additive tend to suffer from very high wear rates, particularly at high tempera-ture.
A further complication in eliminatlng brake chatter is the desire to use the same functional fluid, not only for the brake lubrication, but also for lubrica tion of other tractor parts, such as the hydraulic and mechanical power take-offs, the tractor transmission, gears and bearings, and the like. The functional fluid must act as a lubricant, a power transfer means, and as a heat transfer medium. Obtaining a compoundéd Eluid to ~ "~
meet all of th~ese needs without brake chatter is diff1-05 cUlt.
U.S. Patent No. 3,151/077 teaches the use of borated monoacylated trimethylol alkanes as motor fuel and lubricating oil additives1 The additives are taught to reduce the incidence of surface ignition in an internal 1~ combustion engine and to inhibit the build-up of car-buretor deposits.
U.S. Patent No. 2,795,548 discloses the ùse of lubricating oils compositions containing bora-ted glycerol monooleate. The oil compositions are used in the crank-case of an internal combustion engine in order to reduceoxidation of the oil and corrosion of the metal parts of the engine.
SUMMARY OF THE INVENTION
... . . _ _ It has now been found that oil soluble borated fatty acid esters of glycerol act as appropria~e friction- , modifying ayents, which, when added to a lubricating oil, exhibit good anti-chatter characteristics.
More speci~ically, this invention relates to a method for reducing brake chatter between oil-immersed disc brakes by lubricating the contacting surfaces of said brakes with a composition comprising a major amount of a lubricating oil containing an effective amount to reduce chatter of a-borated fatty acid ester of glycerol.
The borated fatty acid esters of glycerol are prepared by borating a fatty acid ester of glycerol with boric acid with removal of the water of reaction. Prefer-ably, there is sufficient boron present such that each boron will react with from 1O5 to 2.5 hyd~oxyl groups present in the reaction mixture.
The reaction may be carried out at a temperature in the range of 60C to 135C, in the absence or presence of any suitable organic solvent such as methanol, benzene, xylenes, toluene, neutral oil and the like.
Fatty acid esters of glycerol can be prepared by a variety of methods well known in the art. Many oE these esters, such as glycerol monooleate and glycerol tallow-.
ol ~ -ate, are manufactured on a commercial scale. The esters useful for this invention are oil-soluble and are prefer-05 ably prepared from C~ to C22 fatty acids or mixtures thereof such as are foun~ in natural products. The fatty acid may be saturated or unsaturated. Certain compounds found in acids from natural sources may include licanic acid which contains one keto group. Most preferred C~ to C22 fatty acids are those of the formula R-COOH wherein R
is alkyl or alkenyl.
The fatty acid monoester of glycerol is pre-ferred~ however, mixtures of mono- and diesters may be used. Preferably any mixture of mono- and diester con-tains at least 4~% o~ the monoester. Most preferably, mixtures of mono- and diesters of glycerol contain from 40 to 60 percent by weight of the monoester. For example, commercial glycerol monooleate contains a mixture of from 45~ to 55% by weight monoester and from 55% to 45% di-ester.
Preferred fatty acids are oleic, stearic, palmitic, myristic, palmitoleic, linoleic, lauric, linolenic, and eleostearic, and the acids from the natural products tallow, palm oil, olive oil, peanut oil, corn oil, neat's foot oil and the like.
A particularly preferred acid is oleic acid.
Th~ lubricating compositions used in the process of this invention contain a major amount of a lubricating oil and from about 0.1% to 5.0% by weight of the bora~ed fatty acid ester of glycerol preferably from 0.5% to 2% by weight based on the weight of the total composition. The optimum amount of a borated fatty acid ester of glycerol within these ranges will vary slightly depending on the base oil and other additives present in the oil.
Additive concentrates are also included within the scope of this invention. In the concentrate additive form, the borated fatty acid ester of glycerol is present in a concentration ranging from 5% to 50% by weight.
The lubricating compositions are prepared by admixing, using conventional techniques, the appropriate 5fla~
01 ~_ amount of the desired bora~ed fatty acid ester of glycerol with the lubricating oil. When concentrates-are being 05 prepared, the amount of lubricating oil is limited, but is sufficient to dissolve the required amount of borated fatty acid ester of glycerolO Generally, the concentrate will have sufficient borated fatty acid ester of glycerol to permit subsequent dilution with l- to l0 fold more lubricating oil.
The lubricating oil, which may be employed in the practice of this invention, includes a wide variety of hydrocarbon oils derived from synthetic or natural sour-ces, such as naphthenic base, paraffin base, and mixed base oils as are obtained from the refining of crude oil~
Other lubricating oils derived from shale oil, tar sands or coal are also usefulr The lubricating oils may be used individually or in combinations wherever miscible. The lubricating oils generally have a viscosity which ranges from 50 to 5,000 5US (Saybolt Universal Seconds), and usually from l00 to l,500 SUS at 100F. The pre~erredoils have an SAE rating in the range of l0 to 40 and are paraffinic in structure.
In some tractor systems in which the brake fluid is kept in a separate sump, the hydrocarbon oil/borated fatty acid es~er of glycerol composition of this invention is a sufficient lubricant and can be used as such. How-ever, in the more usual tractor systems in which there is a common sump for all functional fluids, e.g., transmis-sion lubricant, hydraulic fluid, and the like, the lubri-cating oil is compounded with a variety of additives.These additives include anti-oxidants, detergents, disper-sants, rust inhibitors, foam inhibitors, corrosion inhibi-tors, anti-wear agents, viscosity index (VI) improvers, friction control agents, elastomer swell agents, extreme pressure (EP) agents, pour point depressants, and metal deactivators. All of these additives are well known in the lubrica~ing oil art.
The preferred additives which may be added to ~ the lubricating oils to which the borated fatty acid 5 ~`~
esters of glycerol are added, are the oil soluble deter-gents, such as the alkali or alkaline earth metal hydro-05 carbyl sulfonates, or alkali or alkaline earth metalphenates, or mixtures thereof, extreme pressure additives, such as the Group II metal salt dihydrocarbyl dithiophos-phates and dispersants such as the alkenyl succinimides, or succinates or mixtures thereof. - -The alkali or alkaline earth metal hydrocarbyl sulfonates may be either petroleum sulfonate, synthetic-ally alkylated aromatic sulfonates, or aliphatic sul-fonates such as those derived from polyisobutylene. One of the more important functions of the sulfonates is to act as a detergent and dispersant. These sulfonates are well known in the art. The hydrocarbyl group must have a sufficient number of carbon atoms to render the sulfonate molecule oil soluble~ Preferably, the hydrocarbyl portion has at least 20 carbon atoms and may be aromatic or ali-phatic, but is usually alkylaromatic. Most preferred foruse are calcium, magnesium or barium sulfonates which are aromatic in character.
Certain sulfonates are typically prepared by sulfonating a petroleum fraction having aromatic groups, usually mono- or dialkylbenzene groups, and then forming the metal salt of the sulfonic acid material. Other feed-stocks used for preparing these sulfonates include syn thetically alkylated benzenes and aliphatic hydrocarbons prepared by polymerizing a mono- or diolefin, for example, - 30 a polyisobutenyl group prepared by polymeriæing isobutene.
The metallic salts are formed directly or by metathesis using well-known procedures.
The sulfonates may be neutral or overbased having base numbers up to about 400 or more. Carbon di-oxide is the most commonly used material to produce thebasic or overbased sulfonates. Mixtures of neutral and overbased sulfonates may be used. The neutral sulfonates are ordinarily used so as to provide from ~ to ~5 milli-moles of sulfonate per kilogram of the total composi-tion. Preferably, the neutral sulfonates are present from 10 to 20 mil~imoles per kilogram of the total composition an~d the overbased sulfonates are present from 50 to 200 OS millimoles per kilogram of the total composition.
The phenates for use in this invention are those conventional products which are the alkali or alkaline earth metal salts of alkylated phenols. One of the func-tions of ~he phenates is to act as a detergent and disper-1~ sant. The phenols may be mono- or polyalkylated.
The alkyl portion of the alkyl phenate is pres-ent to lend oil solubility to the phenate. The alkyl portion can be obtained from naturally occurring or syn-thetic sources. ~aturally occurring sources include petroleum hydrocarbons such as white oil and wax.- Being derived from petroleum, the hydrocarbon moiety is a mix-ture of different hydrocarbyl groups, the specific compo-sition of which depends upon the particular oil stock which was used as a starting material. Suitable synthetic sources include various commercially available alkenes and alkane derivatives which, when reacted with the phenol, yield an alky~phenol. Suitable radicals obtained include butyll hexyl, octyl, decyl, dodecyl, hexadecyl, eicosyl, tricontyl, and the like. Other suitable synthetic sources of the alkyl radical include olefin polymers such as poly-propylene, polybutylene, polyisobutylene and the like.
The alkyl group can be straight-chained or branch-chained, saturated or unsaturated (if unsaturated, preferably containing not more than 2 and generally not more than 1 site of olefinic unsaturation). The alkyl radicals will generally contain from 4 to 30 carbon atomsO
Generally when the phenol is monoalkyl-substituted, the alkyl radical should contain at least 8 carbon atoms. The phenate may be sulfuriæed if desired. It may be either neutral or overbased and if overbased will have a base number of up to 200 to 300 or more. Mixtures of neutral and overbased phenates may be used.
The phenates are ordinarily present in the oil to provide from 10 to 60 millimoles of phenate per kilo-gram of the total composition. Preferably, the neutral 01 _7_ phenates are present from 20 to 50 millimoles per kilogram of the total composition and the overbased phenates are 05 present from S0 to ~00 millimoles per kilogram of the total composition. Preferred metals are calcium, magne-sium, strontium or barium.
The sulfurized alkaline earth metal alkyl phenates may also be used. These salts are ob~ained by a variety of processes such as treating the neutralization product of an alkaline earth metal base and an alkylphenol with sulfur. Conveniently the sulfur, in elemental formt is added to the neutralization product and reacted at elevated temperatures to produce the sulfurized alkaline earth metal alkyl phenate.
If more alkaline earth metal base were added ; during the neutralization reaction than was necessary to neutralize the phenol, a basic sulfurized alkaline earth metal alkyl phenate is obtained. See, for example, the process of Walker et al, U.S. Patent No. 2,680,096. Addi-tional basicity can be obtained by adding carbon dioxide to the basic sulfurized alkaline earth metal alkyl phenate. The excess alkaline earth metal base can be ; added subsequent to the sulfurization step but is conven-iently added at the same time as the alkaline earth metal base is added to neutralize the phenol.
Carbon dioxide is the most commonly used mate-rial to produce the basic or "overbased" phenates. A pro-cess wherein basic sulfurized alkaline earth metal alkyl-phenates are produced by adding carbon dioxide is shown in Hanneman, UlS. Patent No. 3,178,368.
The Group II metal salts of dihydrocarbyl di-thiophosphoric acids exhibi~ wear, antioxidant and thermal stability properties.- Group II metal salts of phospho~o-dithioic acids have been described previously. See, forexample, U.S. Patent No. 3,390,080, columns 6 and 7, wherein these compounds and their preparatlon are described generally. Suitably, the Group II metal salts of the dihydrocarbyl dithiophosphoric acids useful in the lubricating oil composition of this invention contain from 01 ~8- .
about 4 to about 12 carbon atoms in each of the hydro-carbyl radicals and may be the same or different and may 05 be aromatic, alkyl or cycloalkyl. Preferred hydrocarbyl groups are alkyl groups containing from 4 to 8 carbon atoms and are represented by butyl, isobutyl, sec.-butyl, hexyl, isohexyl, octyl, 2-ethylhexyl and the like. The metals suitable for forming these salts include barium, calcium/ strontium, zinc and cadmium, of which zinc is preferred.
Preferably, the Group II metal salt of a dihydrocarbyl dithiophosphoric acid has the following formula:
' 1~
~\ ,.
R30 S_ 2 M
wherein:
e. R2 and R3 each independently represent hydrocarbyl radicals as described above, and f. Ml represents a Group II metal cation as described above.
The dithiophosphoric salts are present in the lubricating oil composition in an amount effective to inhibit wear and oxidation of the lubricating oil. The preferred amount ranges from about 3 to 30 millimoles of dithiophosphoric salt per kilogram of the total composi-tion. Most preferably the salt is present in an amount ranging from about 15 to 20 millimoles per kilogram of the total lubricating oil composition.
The alkenyl succinimide or succlnate or mixtures - J
thereof are present to, among other things~ act as a dis-persant and prevent formation of deposits. The alkenyl succinimides and succinates are well known in the art.
The alkenyl succinimides are the reaction product of a polyolefin polyrner-substituted succinic anhydride with an amine, preferably a polyalkylene polyamine, and the 4~
alkenyl succinates are the reaction product of a polyolefin polymer-substituted succinic anhydride with monohydric and polyhydric alcohols, phenols and naphthols, preferably a polyhydric alcohol containing at least three hydroxy radicals.
The polyolefin polymer-substituted succinic anhydrides are obtained by reaction of a polyolefin polymer or a derivative thereof with maleic anhydride. The succinic anhydride thus obtained is reacted with the amine or hydroxy compound. The preparation of the alkenyl succinimides has been described many times in the art. See, for example United Stat:es Patent Nos. 3r390,082, 3,219,666 and 3,172,892. The preparation of the alkenyl succinates has also been described in the art.
See, for example, United States Patent Nos. 3,381,022 and 3,522,179.
Particularly good results may be obtained with the lubricating oil compositions of this invention when the alkenyl succinimide or succinate is a polyisobutene-substituted succinic anhydride of a polyalkylene polyamine or polyhydric alcohol, respectively.
The polyisobutene from which the polyisobutene-substituted succinic anhydride is obtained by polymerizing isobutene and can vary widely in its compositions. The average number of carbon atoms can range from 30 or less to 250 or more,with aresulting number average molecular weight of about 400 or less to 3,000 or more. Preferably, the average number of carbon atoms per polyisobutene molecule will range from about 50 to about 100 with the polyisobutenes having a number average molecular weight of about 600 to about 1,500. More pre ferably, the average number of carbon atoms per polyisobu-.~
-9a-tene molecule ranges from about 60 to about 90, and the number average molecular weight ranges from about 800 to 1,300. The polyisobutene is reacted with maleic anhydride according to well-known procedures to yield ~he polyisobutene-substituted succinic anhydride.
,.~ ..
In preparing the alkenyl succinimide, the sub-stituted succinic anhydride is reacted with a polyalkylene 05 polyamine to yield the corresponding succinimide. Each alkylene radical of the polyalkylene polyamine usually has up-to about 8 carbon atoms. The number of alkylene radi-cals can range up to about 8. The alkylene radical is exemplified by ethylene, propylene~ butylene, trimethyl-1~ ene, tetramethylene, pentamethylene, he~amethylene, octa-methylene, etc. The number of amino groups generallyl but not necessarily~ is one greater than the number of alkylene radicals present in the amine, i.e., if a poly-alkylene polyamine contains 3 alkylene radicals, it will usually contain 4 amino radicals. The number of amino radicals can range up to about 9. Preferably, the alkyl-ene radical contains from about 2 to about 4 carbon atoms and all amine groups are primary or secondary. In this case, the number of amine groups exceeds the number of alkylene groups by l. Preferably the polyalkylene poly-amine contains from 3 to 5 amine groupsn Specific exam-ples of the polyalkylene polyamines include ethylenedi-amine, diethylenetriamine, triethylenetetramine, propyl-enediamine, tripropylenetetramine, tetraethylenepentamine, trimethylenediamine, pentaethylenehexamine, di-(tri-methylene)triamine, tri(hexamethylene)tetramine, etc.
Other amines suitable for preparing the alkenyl succinimide useful in this invention include the cyclic amines such as pi~erizine, morpholine and dipiperizines.
Preferably the alkenyl succinimides which may be used in the compositions of this invention have thefollowing formulao Rl-CH--C 9~
¦ \ NtAlkylene-NtnH
CH2-C~
wherein:
aO Rl represents an alkenyl group, preferably a sub-05 stantially saturated hydrocarbon prepared by polymerizingalipha~ic monoolefins. Preferably Rl is prepared from isobutene and has an average number of carbon atoms and a number average molecular weight as described above;
b. the 'IAlkylene" radical represents a substantially hydrocarbyl group containing up to about 8 carbon atoms and preferably containing from about 2-4 carbon atoms as described hereinabove;
cO A represents a hydrocarbyl group, an amine-sub-stituted hydrocarbyl group, or hydrogen. The hydrocarbyl group and the amine-substituted hydrocarbyl groups are generally the alkyl and amino-substituted alkyl analogs of the alkylene radicals described above. Preferably A
represents hydrogen;
d. n represents an integer of from about 1 to 10, and preferably from about 3-5.
The alkenyl succinimide can be reacted with boric acid or a similar boron-containing compound to form borated dispersants having utility in this invention. The borated succinimides are intended to be included within the scope of the term "alkenyl succinimide".
The alkenyl succinates are those of the above-described succinic anhydride with ilydroxy compounds which may be aliphatic compounds such as monohydric and poly-hydric alcohols or aromatic compounds such as phenols and naphthols. The aromatic hydroxy compounds from which the esters may be derived are illustrated by the following specific examples: phenol, beta-naphthol, alpha-naphthol, cresol, resorcinol, catehol, p,p'-dihydroxybiphenyl,
IN OIL-IMMERSED DISC BRAKES
FIELD OF THE INVENTION
This invention relates to lubricating oll com-positions, particularly to lubricating oil compositions useful as functional fluids in systems requiring coupling, hydraulic fluids and/or lubrication of relatively moving parts. ~ore particularly, it is concerned with functional fluids for use in the lubrication of heavy machinery, particularly high-power-output tractors r and to the reduc-tion of brake chatter therein.
DESCRIPTION OF THE PRIOR ART
The use of heavy machinery, such as a tractor, has increased the demand for high-performance lubricating compositions. Modern tractors have many power-assisted components, such as power steering and power brakes.
Power brakes are preferably of the disc type since they have greater braking capacityO The preferred disc brakes are the wet-type brake, which are immersed in a lubricant and are therefore isolated from dirt and grime~
Such brakes suffer from at least one problem, namely, brake chatter or brake squawk. This phenomenon is a very unpleasant noise that occurs upon application of the brake. In the past, friction-modifying agents, such - as dioleylhydrogen phosphite, have been added to the brake lubricating composition to reduce the chatter. Lubricat-ing compositions containing this additive tend to suffer from very high wear rates, particularly at high tempera-ture.
A further complication in eliminatlng brake chatter is the desire to use the same functional fluid, not only for the brake lubrication, but also for lubrica tion of other tractor parts, such as the hydraulic and mechanical power take-offs, the tractor transmission, gears and bearings, and the like. The functional fluid must act as a lubricant, a power transfer means, and as a heat transfer medium. Obtaining a compoundéd Eluid to ~ "~
meet all of th~ese needs without brake chatter is diff1-05 cUlt.
U.S. Patent No. 3,151/077 teaches the use of borated monoacylated trimethylol alkanes as motor fuel and lubricating oil additives1 The additives are taught to reduce the incidence of surface ignition in an internal 1~ combustion engine and to inhibit the build-up of car-buretor deposits.
U.S. Patent No. 2,795,548 discloses the ùse of lubricating oils compositions containing bora-ted glycerol monooleate. The oil compositions are used in the crank-case of an internal combustion engine in order to reduceoxidation of the oil and corrosion of the metal parts of the engine.
SUMMARY OF THE INVENTION
... . . _ _ It has now been found that oil soluble borated fatty acid esters of glycerol act as appropria~e friction- , modifying ayents, which, when added to a lubricating oil, exhibit good anti-chatter characteristics.
More speci~ically, this invention relates to a method for reducing brake chatter between oil-immersed disc brakes by lubricating the contacting surfaces of said brakes with a composition comprising a major amount of a lubricating oil containing an effective amount to reduce chatter of a-borated fatty acid ester of glycerol.
The borated fatty acid esters of glycerol are prepared by borating a fatty acid ester of glycerol with boric acid with removal of the water of reaction. Prefer-ably, there is sufficient boron present such that each boron will react with from 1O5 to 2.5 hyd~oxyl groups present in the reaction mixture.
The reaction may be carried out at a temperature in the range of 60C to 135C, in the absence or presence of any suitable organic solvent such as methanol, benzene, xylenes, toluene, neutral oil and the like.
Fatty acid esters of glycerol can be prepared by a variety of methods well known in the art. Many oE these esters, such as glycerol monooleate and glycerol tallow-.
ol ~ -ate, are manufactured on a commercial scale. The esters useful for this invention are oil-soluble and are prefer-05 ably prepared from C~ to C22 fatty acids or mixtures thereof such as are foun~ in natural products. The fatty acid may be saturated or unsaturated. Certain compounds found in acids from natural sources may include licanic acid which contains one keto group. Most preferred C~ to C22 fatty acids are those of the formula R-COOH wherein R
is alkyl or alkenyl.
The fatty acid monoester of glycerol is pre-ferred~ however, mixtures of mono- and diesters may be used. Preferably any mixture of mono- and diester con-tains at least 4~% o~ the monoester. Most preferably, mixtures of mono- and diesters of glycerol contain from 40 to 60 percent by weight of the monoester. For example, commercial glycerol monooleate contains a mixture of from 45~ to 55% by weight monoester and from 55% to 45% di-ester.
Preferred fatty acids are oleic, stearic, palmitic, myristic, palmitoleic, linoleic, lauric, linolenic, and eleostearic, and the acids from the natural products tallow, palm oil, olive oil, peanut oil, corn oil, neat's foot oil and the like.
A particularly preferred acid is oleic acid.
Th~ lubricating compositions used in the process of this invention contain a major amount of a lubricating oil and from about 0.1% to 5.0% by weight of the bora~ed fatty acid ester of glycerol preferably from 0.5% to 2% by weight based on the weight of the total composition. The optimum amount of a borated fatty acid ester of glycerol within these ranges will vary slightly depending on the base oil and other additives present in the oil.
Additive concentrates are also included within the scope of this invention. In the concentrate additive form, the borated fatty acid ester of glycerol is present in a concentration ranging from 5% to 50% by weight.
The lubricating compositions are prepared by admixing, using conventional techniques, the appropriate 5fla~
01 ~_ amount of the desired bora~ed fatty acid ester of glycerol with the lubricating oil. When concentrates-are being 05 prepared, the amount of lubricating oil is limited, but is sufficient to dissolve the required amount of borated fatty acid ester of glycerolO Generally, the concentrate will have sufficient borated fatty acid ester of glycerol to permit subsequent dilution with l- to l0 fold more lubricating oil.
The lubricating oil, which may be employed in the practice of this invention, includes a wide variety of hydrocarbon oils derived from synthetic or natural sour-ces, such as naphthenic base, paraffin base, and mixed base oils as are obtained from the refining of crude oil~
Other lubricating oils derived from shale oil, tar sands or coal are also usefulr The lubricating oils may be used individually or in combinations wherever miscible. The lubricating oils generally have a viscosity which ranges from 50 to 5,000 5US (Saybolt Universal Seconds), and usually from l00 to l,500 SUS at 100F. The pre~erredoils have an SAE rating in the range of l0 to 40 and are paraffinic in structure.
In some tractor systems in which the brake fluid is kept in a separate sump, the hydrocarbon oil/borated fatty acid es~er of glycerol composition of this invention is a sufficient lubricant and can be used as such. How-ever, in the more usual tractor systems in which there is a common sump for all functional fluids, e.g., transmis-sion lubricant, hydraulic fluid, and the like, the lubri-cating oil is compounded with a variety of additives.These additives include anti-oxidants, detergents, disper-sants, rust inhibitors, foam inhibitors, corrosion inhibi-tors, anti-wear agents, viscosity index (VI) improvers, friction control agents, elastomer swell agents, extreme pressure (EP) agents, pour point depressants, and metal deactivators. All of these additives are well known in the lubrica~ing oil art.
The preferred additives which may be added to ~ the lubricating oils to which the borated fatty acid 5 ~`~
esters of glycerol are added, are the oil soluble deter-gents, such as the alkali or alkaline earth metal hydro-05 carbyl sulfonates, or alkali or alkaline earth metalphenates, or mixtures thereof, extreme pressure additives, such as the Group II metal salt dihydrocarbyl dithiophos-phates and dispersants such as the alkenyl succinimides, or succinates or mixtures thereof. - -The alkali or alkaline earth metal hydrocarbyl sulfonates may be either petroleum sulfonate, synthetic-ally alkylated aromatic sulfonates, or aliphatic sul-fonates such as those derived from polyisobutylene. One of the more important functions of the sulfonates is to act as a detergent and dispersant. These sulfonates are well known in the art. The hydrocarbyl group must have a sufficient number of carbon atoms to render the sulfonate molecule oil soluble~ Preferably, the hydrocarbyl portion has at least 20 carbon atoms and may be aromatic or ali-phatic, but is usually alkylaromatic. Most preferred foruse are calcium, magnesium or barium sulfonates which are aromatic in character.
Certain sulfonates are typically prepared by sulfonating a petroleum fraction having aromatic groups, usually mono- or dialkylbenzene groups, and then forming the metal salt of the sulfonic acid material. Other feed-stocks used for preparing these sulfonates include syn thetically alkylated benzenes and aliphatic hydrocarbons prepared by polymerizing a mono- or diolefin, for example, - 30 a polyisobutenyl group prepared by polymeriæing isobutene.
The metallic salts are formed directly or by metathesis using well-known procedures.
The sulfonates may be neutral or overbased having base numbers up to about 400 or more. Carbon di-oxide is the most commonly used material to produce thebasic or overbased sulfonates. Mixtures of neutral and overbased sulfonates may be used. The neutral sulfonates are ordinarily used so as to provide from ~ to ~5 milli-moles of sulfonate per kilogram of the total composi-tion. Preferably, the neutral sulfonates are present from 10 to 20 mil~imoles per kilogram of the total composition an~d the overbased sulfonates are present from 50 to 200 OS millimoles per kilogram of the total composition.
The phenates for use in this invention are those conventional products which are the alkali or alkaline earth metal salts of alkylated phenols. One of the func-tions of ~he phenates is to act as a detergent and disper-1~ sant. The phenols may be mono- or polyalkylated.
The alkyl portion of the alkyl phenate is pres-ent to lend oil solubility to the phenate. The alkyl portion can be obtained from naturally occurring or syn-thetic sources. ~aturally occurring sources include petroleum hydrocarbons such as white oil and wax.- Being derived from petroleum, the hydrocarbon moiety is a mix-ture of different hydrocarbyl groups, the specific compo-sition of which depends upon the particular oil stock which was used as a starting material. Suitable synthetic sources include various commercially available alkenes and alkane derivatives which, when reacted with the phenol, yield an alky~phenol. Suitable radicals obtained include butyll hexyl, octyl, decyl, dodecyl, hexadecyl, eicosyl, tricontyl, and the like. Other suitable synthetic sources of the alkyl radical include olefin polymers such as poly-propylene, polybutylene, polyisobutylene and the like.
The alkyl group can be straight-chained or branch-chained, saturated or unsaturated (if unsaturated, preferably containing not more than 2 and generally not more than 1 site of olefinic unsaturation). The alkyl radicals will generally contain from 4 to 30 carbon atomsO
Generally when the phenol is monoalkyl-substituted, the alkyl radical should contain at least 8 carbon atoms. The phenate may be sulfuriæed if desired. It may be either neutral or overbased and if overbased will have a base number of up to 200 to 300 or more. Mixtures of neutral and overbased phenates may be used.
The phenates are ordinarily present in the oil to provide from 10 to 60 millimoles of phenate per kilo-gram of the total composition. Preferably, the neutral 01 _7_ phenates are present from 20 to 50 millimoles per kilogram of the total composition and the overbased phenates are 05 present from S0 to ~00 millimoles per kilogram of the total composition. Preferred metals are calcium, magne-sium, strontium or barium.
The sulfurized alkaline earth metal alkyl phenates may also be used. These salts are ob~ained by a variety of processes such as treating the neutralization product of an alkaline earth metal base and an alkylphenol with sulfur. Conveniently the sulfur, in elemental formt is added to the neutralization product and reacted at elevated temperatures to produce the sulfurized alkaline earth metal alkyl phenate.
If more alkaline earth metal base were added ; during the neutralization reaction than was necessary to neutralize the phenol, a basic sulfurized alkaline earth metal alkyl phenate is obtained. See, for example, the process of Walker et al, U.S. Patent No. 2,680,096. Addi-tional basicity can be obtained by adding carbon dioxide to the basic sulfurized alkaline earth metal alkyl phenate. The excess alkaline earth metal base can be ; added subsequent to the sulfurization step but is conven-iently added at the same time as the alkaline earth metal base is added to neutralize the phenol.
Carbon dioxide is the most commonly used mate-rial to produce the basic or "overbased" phenates. A pro-cess wherein basic sulfurized alkaline earth metal alkyl-phenates are produced by adding carbon dioxide is shown in Hanneman, UlS. Patent No. 3,178,368.
The Group II metal salts of dihydrocarbyl di-thiophosphoric acids exhibi~ wear, antioxidant and thermal stability properties.- Group II metal salts of phospho~o-dithioic acids have been described previously. See, forexample, U.S. Patent No. 3,390,080, columns 6 and 7, wherein these compounds and their preparatlon are described generally. Suitably, the Group II metal salts of the dihydrocarbyl dithiophosphoric acids useful in the lubricating oil composition of this invention contain from 01 ~8- .
about 4 to about 12 carbon atoms in each of the hydro-carbyl radicals and may be the same or different and may 05 be aromatic, alkyl or cycloalkyl. Preferred hydrocarbyl groups are alkyl groups containing from 4 to 8 carbon atoms and are represented by butyl, isobutyl, sec.-butyl, hexyl, isohexyl, octyl, 2-ethylhexyl and the like. The metals suitable for forming these salts include barium, calcium/ strontium, zinc and cadmium, of which zinc is preferred.
Preferably, the Group II metal salt of a dihydrocarbyl dithiophosphoric acid has the following formula:
' 1~
~\ ,.
R30 S_ 2 M
wherein:
e. R2 and R3 each independently represent hydrocarbyl radicals as described above, and f. Ml represents a Group II metal cation as described above.
The dithiophosphoric salts are present in the lubricating oil composition in an amount effective to inhibit wear and oxidation of the lubricating oil. The preferred amount ranges from about 3 to 30 millimoles of dithiophosphoric salt per kilogram of the total composi-tion. Most preferably the salt is present in an amount ranging from about 15 to 20 millimoles per kilogram of the total lubricating oil composition.
The alkenyl succinimide or succlnate or mixtures - J
thereof are present to, among other things~ act as a dis-persant and prevent formation of deposits. The alkenyl succinimides and succinates are well known in the art.
The alkenyl succinimides are the reaction product of a polyolefin polyrner-substituted succinic anhydride with an amine, preferably a polyalkylene polyamine, and the 4~
alkenyl succinates are the reaction product of a polyolefin polymer-substituted succinic anhydride with monohydric and polyhydric alcohols, phenols and naphthols, preferably a polyhydric alcohol containing at least three hydroxy radicals.
The polyolefin polymer-substituted succinic anhydrides are obtained by reaction of a polyolefin polymer or a derivative thereof with maleic anhydride. The succinic anhydride thus obtained is reacted with the amine or hydroxy compound. The preparation of the alkenyl succinimides has been described many times in the art. See, for example United Stat:es Patent Nos. 3r390,082, 3,219,666 and 3,172,892. The preparation of the alkenyl succinates has also been described in the art.
See, for example, United States Patent Nos. 3,381,022 and 3,522,179.
Particularly good results may be obtained with the lubricating oil compositions of this invention when the alkenyl succinimide or succinate is a polyisobutene-substituted succinic anhydride of a polyalkylene polyamine or polyhydric alcohol, respectively.
The polyisobutene from which the polyisobutene-substituted succinic anhydride is obtained by polymerizing isobutene and can vary widely in its compositions. The average number of carbon atoms can range from 30 or less to 250 or more,with aresulting number average molecular weight of about 400 or less to 3,000 or more. Preferably, the average number of carbon atoms per polyisobutene molecule will range from about 50 to about 100 with the polyisobutenes having a number average molecular weight of about 600 to about 1,500. More pre ferably, the average number of carbon atoms per polyisobu-.~
-9a-tene molecule ranges from about 60 to about 90, and the number average molecular weight ranges from about 800 to 1,300. The polyisobutene is reacted with maleic anhydride according to well-known procedures to yield ~he polyisobutene-substituted succinic anhydride.
,.~ ..
In preparing the alkenyl succinimide, the sub-stituted succinic anhydride is reacted with a polyalkylene 05 polyamine to yield the corresponding succinimide. Each alkylene radical of the polyalkylene polyamine usually has up-to about 8 carbon atoms. The number of alkylene radi-cals can range up to about 8. The alkylene radical is exemplified by ethylene, propylene~ butylene, trimethyl-1~ ene, tetramethylene, pentamethylene, he~amethylene, octa-methylene, etc. The number of amino groups generallyl but not necessarily~ is one greater than the number of alkylene radicals present in the amine, i.e., if a poly-alkylene polyamine contains 3 alkylene radicals, it will usually contain 4 amino radicals. The number of amino radicals can range up to about 9. Preferably, the alkyl-ene radical contains from about 2 to about 4 carbon atoms and all amine groups are primary or secondary. In this case, the number of amine groups exceeds the number of alkylene groups by l. Preferably the polyalkylene poly-amine contains from 3 to 5 amine groupsn Specific exam-ples of the polyalkylene polyamines include ethylenedi-amine, diethylenetriamine, triethylenetetramine, propyl-enediamine, tripropylenetetramine, tetraethylenepentamine, trimethylenediamine, pentaethylenehexamine, di-(tri-methylene)triamine, tri(hexamethylene)tetramine, etc.
Other amines suitable for preparing the alkenyl succinimide useful in this invention include the cyclic amines such as pi~erizine, morpholine and dipiperizines.
Preferably the alkenyl succinimides which may be used in the compositions of this invention have thefollowing formulao Rl-CH--C 9~
¦ \ NtAlkylene-NtnH
CH2-C~
wherein:
aO Rl represents an alkenyl group, preferably a sub-05 stantially saturated hydrocarbon prepared by polymerizingalipha~ic monoolefins. Preferably Rl is prepared from isobutene and has an average number of carbon atoms and a number average molecular weight as described above;
b. the 'IAlkylene" radical represents a substantially hydrocarbyl group containing up to about 8 carbon atoms and preferably containing from about 2-4 carbon atoms as described hereinabove;
cO A represents a hydrocarbyl group, an amine-sub-stituted hydrocarbyl group, or hydrogen. The hydrocarbyl group and the amine-substituted hydrocarbyl groups are generally the alkyl and amino-substituted alkyl analogs of the alkylene radicals described above. Preferably A
represents hydrogen;
d. n represents an integer of from about 1 to 10, and preferably from about 3-5.
The alkenyl succinimide can be reacted with boric acid or a similar boron-containing compound to form borated dispersants having utility in this invention. The borated succinimides are intended to be included within the scope of the term "alkenyl succinimide".
The alkenyl succinates are those of the above-described succinic anhydride with ilydroxy compounds which may be aliphatic compounds such as monohydric and poly-hydric alcohols or aromatic compounds such as phenols and naphthols. The aromatic hydroxy compounds from which the esters may be derived are illustrated by the following specific examples: phenol, beta-naphthol, alpha-naphthol, cresol, resorcinol, catehol, p,p'-dihydroxybiphenyl,
2-chlorophenol, 2,4-dibutylphenol, propene tetramer-sub~
stituted phenol, didodecylphenol, 4,4'~methylene-bis-phenol, alpha-decyl-beta naphthol, polyisobutenetmolecular weight of 1000)-substituted phenol, the condensation prod-uct of heptylphenol with 0.5 mole of formaldehyde, the condensation product of octylphenol with acetone, di(hydroxyphenyl)oxide, di(hydroxyphenyl)sulfide, 5 ~
.
di(hydroxyphenyl)disulfide, and 4-cyclohexylphenol.
Phenol and alkylated phenols having up to three alkyl sub-05 stituents are preferred. Each of the alkyl substituents may contain 100 or more carbon atomsc The alcohols from which the esters may be derived preferably contain up to about 40 aliphatic carbon atoms. They may be monohydric alcohols such as methanol, ethanol, isooctanol, dodecanol, cyclohexanol, cyclo~
pentanol, behenyl alcohol, hexatriacontanol, neopentyl alcohol, isobutyl alcohol, benzyl alcohol, betaphenylethyl alcohol, 2-methylcyclohexanol, beta-chloroethanol, mono-methyl ether of ethylene glycol, monobutyl ether of ethylene glycol, monopropyl ether of diethylene glycol, monododecyl ether of triethylene glycol, monooleate ofethylene ~lycol, monostearate of diethylene glycol, sec-pentyl alcohol, tert-butyl alcohol, 5-bromo-dodecanol, nitro-octadecanol and dioleate of glycerol. The poly-hydric alcohols preferably contain from 2 to about 10 hydroxy radicals. They are illustrated by, for example, ethylene glysol, diethylene glycol, triethylene glycol, tetraethylene glycol; dipropylene glycol, tripropylene glycol, dibutylene glycol, tributylene glycol, and other alkylene glycols in which the alkylene radical contaïns from 2 to about 8 carbon atoms. Other useful polyhydric alcohols incLude glycerol, monooleate of glycerol, mono-methyl ether of glycerol, pentraerythritol, 9,10-dihydroxy stearic acid, methyl ester of 9,10-dihydroxy stearic acid, 1,2-butanediol, 2,3-hexanediol, 2,4-hexanediol, pinacol, erythritol, arabitol, sorbitol, mannitol, 1,2-cyclohexane-diol, and xylene glycolO Carbohydrates such as sugars, starches, celluloses, etc., likewise may yield esters.
The carbohydrates may be exemplified by a glucose, fruc-tose, sucrose, rhamnose, mannose, glyceraldehyde, and galactose.
An especially preferred class of polyhydric alcohols are those having at least three hydroxy radicals, some of which have been esterified with a monocarboxylic acid having from about 8 to about 30 carbon atoms such as 5~0 octanoic acid, oleic acid, stearic acid, linoleic acid, dodecanoic acid, or tall oil acid. Examples of such par-05 tially esterified polyhydric alcohols are the monooleateof sorbitol, distearate of sorbitol, monooleate of gly-cerol, monostearate of glycerol, di-dodecanoate of erythritol.
The esters may also be derived from unsaturated alcohols such as allyl alcohol, cinnamyl alcohol, prop-argyl alcohol, l-cyclohexene-3-ol, an oleyl alcohol.
Still other classes of the alcohols capable of yielding the esters of this inventlon comprises the ether-alcohols and amino-alcohols including, for example, the oxy-alkylene-, oxy-arylene-, amino-alkylene-, and amino-arylene-substituted alcohols having one or more oxy-alkylene, amlno-alkylene or amino-arylene oxy-arylene radicals. They are exemplified by Cellosolvet carbitol, phenoxy-ethanol, heptylphenyl-(oxypropylene)6-H, octyl-(oxyethylene)30-HI phenyl(oxyoctylene)2-EI, mono(heptyl-phenyl-oxypropylene)-substituted glycerol, poly(styrene oxide), amino-ethanol, 3-amino ethyl-pentanol, di(hydroxy-ethyl)amine, p-aminophenol, tri(hydroxypropyl)amine, N-hydroxyethyl ethylene diamine, N,N,N',N'-tetrahydroxy-trimethylene diamine, and the like~ For the most part,the ether~alcohols having up to about 150 oxy-alkylene radicals in which the alkylene radical contains from 1 to about 8 carbon atoms are preferred.
The esters may be di-esters of succinic acids or acidlc esters, i.e., partially esterified succinic acids, as well as partially esterified polyhydric alcohols or phenols, i.e., esters having free alcoholic or phenolic hydroxyl radicals. Mixtures of the above-illustrated esters likewise are contemplated within the scope of the invention.
The alkenyl succinates can be reacted ~ith boric acid or a similar boron-containing compound to form borated dispersants having utility in this invention.
Such borated succinates are described in U.S. Patent No.
40 3,533,945. The borated succinates are intended to be . , .
i4~
included within the scope of the term 'lalkenyl succinate."
05 The alkenyl succinimide and succinates are pres-ent in the lubricating oil compositions in an amount effective to act as a dispersant and prevent the deposit of contaminants formed in the oil. The amount of alkenyl succinimide and succinates can range from about 0.5 per-cent to about 20 percent weight of the total lubricating oil composition. Preferably the amount of alkenyl succinimide or succinate which may be present in the lubricating oil composition ranges from about 2 to about 5 percent by weight of the total composition.
The finished lubricating oil may be single or multigrade. Multigrade lubricating oils are prepared by adding viscosity index (VI) improvers. Typical viscosity index improvers are polyalkyl methacrylates, ethylene propylene copolymers, styrene diene copolymers and the like. So-called decorated VI improvers having both visco-sity index and dispersant properties are also suitable for use in the formula~ions of this invention.
The following e~amples are offered to specific-ally illustrate the invention. These examples and illus-trations are not to be construed in any way as limitingthe scope of the invention.
Example 1 Preparation of Borated Glycerol ~onooleate To a mixture containing 125.23 grams of glycerol monooleate (45% to 55~ by weight) and glycerol dioleate (55~ to 45~ by weight) were added 30.92 grams boric acid and 250 mls. of xylene. The reaction mixture was heated at 99 to 141C for about nine and one-haif hours under nitrogen at azeotropic conditions. 17.6 mls. of water were collected by a Dean Stark trap. ~he reaction product was filtered and stripped on a roto evaporator under vacuum to 135C to yield 128.35 grams. Analysis: boron 2.42~ and 2.52% hydroxyl number 32 mg KOH/gmO Infrared spectroscopy analysis of the product shows no free , glycerol-type hydroxyl stretching but does have strong BO-H bond and virtually no B-O~B-type absorption.
oS Example 2 The compositions of this invention were tested in a laboratory test~ The test was carried out on an SAE
No. 2 friction machine modified by adding a moderate-speed hydraulic motor drive. The test specimen was a sandwich of one General Metals Powder Co. 1500 mix sintered bronze plate between two steel spacer plates mounted in the above apparatus, The test fluidj about 300 grams in quantity, was then charged to the t~st-oil sump~ The hydraulic drive rotated the test specimens at 100 rpm~ A piston-like brake was applied at an apply pressure of 75 psig.The SAE No. 2 load cell measured the braking torque and an electric tachometer measured rpm. An x-y plotter was used to produce a trace of torque versus rpm as the hydraulic drive was slowly adjusted to decrease the speed to 0 rpm.
The brake chatter performance of a fluid is related to the slope of the friction VSr velocity curve- The slope of the curve is found by measuring the slope of a line drawn through the 50 rpm point on the trace and the highest point on the trace below 50 rpmO As the slope of this curve becomes increasingly negative, the brake chatter noise becomes progressively louder. This tendency correlates with full scale tractor brake noise tests.
The above described test was run on three mineral oil based tractor hydraulic fluids. The results or these three fluids are shown in Table I. Composition A was a base without a friction modifier and composition contains in addition 1~ borated glycerol monooleate of Example 1. Composition C is a commercial~tractor hydraulic fluid. As shown in Table I, the addition of borated glycerol monooleate (Fluid B) to the base fluid (Fluid A) increased the slope indicating it is effective in reducing brake chatter. Also shown in Table 1 is the slope obtained with a commercial tractor hyraulic fluid.
~0 5~
. TABLE I
Effect of Borated Fatty Acid Ester 05upon Laboratory Brake Chatter Simulation .Slope of Friction Formulation Velocity Curve ... .. . .. . .. . . _ _ A - base oil -.0131 B - base oi7 ~ 1% by . -.0092 weight Borated glycerol oleate of Example 1 C - Commercial Formulation-.0143 .
,
stituted phenol, didodecylphenol, 4,4'~methylene-bis-phenol, alpha-decyl-beta naphthol, polyisobutenetmolecular weight of 1000)-substituted phenol, the condensation prod-uct of heptylphenol with 0.5 mole of formaldehyde, the condensation product of octylphenol with acetone, di(hydroxyphenyl)oxide, di(hydroxyphenyl)sulfide, 5 ~
.
di(hydroxyphenyl)disulfide, and 4-cyclohexylphenol.
Phenol and alkylated phenols having up to three alkyl sub-05 stituents are preferred. Each of the alkyl substituents may contain 100 or more carbon atomsc The alcohols from which the esters may be derived preferably contain up to about 40 aliphatic carbon atoms. They may be monohydric alcohols such as methanol, ethanol, isooctanol, dodecanol, cyclohexanol, cyclo~
pentanol, behenyl alcohol, hexatriacontanol, neopentyl alcohol, isobutyl alcohol, benzyl alcohol, betaphenylethyl alcohol, 2-methylcyclohexanol, beta-chloroethanol, mono-methyl ether of ethylene glycol, monobutyl ether of ethylene glycol, monopropyl ether of diethylene glycol, monododecyl ether of triethylene glycol, monooleate ofethylene ~lycol, monostearate of diethylene glycol, sec-pentyl alcohol, tert-butyl alcohol, 5-bromo-dodecanol, nitro-octadecanol and dioleate of glycerol. The poly-hydric alcohols preferably contain from 2 to about 10 hydroxy radicals. They are illustrated by, for example, ethylene glysol, diethylene glycol, triethylene glycol, tetraethylene glycol; dipropylene glycol, tripropylene glycol, dibutylene glycol, tributylene glycol, and other alkylene glycols in which the alkylene radical contaïns from 2 to about 8 carbon atoms. Other useful polyhydric alcohols incLude glycerol, monooleate of glycerol, mono-methyl ether of glycerol, pentraerythritol, 9,10-dihydroxy stearic acid, methyl ester of 9,10-dihydroxy stearic acid, 1,2-butanediol, 2,3-hexanediol, 2,4-hexanediol, pinacol, erythritol, arabitol, sorbitol, mannitol, 1,2-cyclohexane-diol, and xylene glycolO Carbohydrates such as sugars, starches, celluloses, etc., likewise may yield esters.
The carbohydrates may be exemplified by a glucose, fruc-tose, sucrose, rhamnose, mannose, glyceraldehyde, and galactose.
An especially preferred class of polyhydric alcohols are those having at least three hydroxy radicals, some of which have been esterified with a monocarboxylic acid having from about 8 to about 30 carbon atoms such as 5~0 octanoic acid, oleic acid, stearic acid, linoleic acid, dodecanoic acid, or tall oil acid. Examples of such par-05 tially esterified polyhydric alcohols are the monooleateof sorbitol, distearate of sorbitol, monooleate of gly-cerol, monostearate of glycerol, di-dodecanoate of erythritol.
The esters may also be derived from unsaturated alcohols such as allyl alcohol, cinnamyl alcohol, prop-argyl alcohol, l-cyclohexene-3-ol, an oleyl alcohol.
Still other classes of the alcohols capable of yielding the esters of this inventlon comprises the ether-alcohols and amino-alcohols including, for example, the oxy-alkylene-, oxy-arylene-, amino-alkylene-, and amino-arylene-substituted alcohols having one or more oxy-alkylene, amlno-alkylene or amino-arylene oxy-arylene radicals. They are exemplified by Cellosolvet carbitol, phenoxy-ethanol, heptylphenyl-(oxypropylene)6-H, octyl-(oxyethylene)30-HI phenyl(oxyoctylene)2-EI, mono(heptyl-phenyl-oxypropylene)-substituted glycerol, poly(styrene oxide), amino-ethanol, 3-amino ethyl-pentanol, di(hydroxy-ethyl)amine, p-aminophenol, tri(hydroxypropyl)amine, N-hydroxyethyl ethylene diamine, N,N,N',N'-tetrahydroxy-trimethylene diamine, and the like~ For the most part,the ether~alcohols having up to about 150 oxy-alkylene radicals in which the alkylene radical contains from 1 to about 8 carbon atoms are preferred.
The esters may be di-esters of succinic acids or acidlc esters, i.e., partially esterified succinic acids, as well as partially esterified polyhydric alcohols or phenols, i.e., esters having free alcoholic or phenolic hydroxyl radicals. Mixtures of the above-illustrated esters likewise are contemplated within the scope of the invention.
The alkenyl succinates can be reacted ~ith boric acid or a similar boron-containing compound to form borated dispersants having utility in this invention.
Such borated succinates are described in U.S. Patent No.
40 3,533,945. The borated succinates are intended to be . , .
i4~
included within the scope of the term 'lalkenyl succinate."
05 The alkenyl succinimide and succinates are pres-ent in the lubricating oil compositions in an amount effective to act as a dispersant and prevent the deposit of contaminants formed in the oil. The amount of alkenyl succinimide and succinates can range from about 0.5 per-cent to about 20 percent weight of the total lubricating oil composition. Preferably the amount of alkenyl succinimide or succinate which may be present in the lubricating oil composition ranges from about 2 to about 5 percent by weight of the total composition.
The finished lubricating oil may be single or multigrade. Multigrade lubricating oils are prepared by adding viscosity index (VI) improvers. Typical viscosity index improvers are polyalkyl methacrylates, ethylene propylene copolymers, styrene diene copolymers and the like. So-called decorated VI improvers having both visco-sity index and dispersant properties are also suitable for use in the formula~ions of this invention.
The following e~amples are offered to specific-ally illustrate the invention. These examples and illus-trations are not to be construed in any way as limitingthe scope of the invention.
Example 1 Preparation of Borated Glycerol ~onooleate To a mixture containing 125.23 grams of glycerol monooleate (45% to 55~ by weight) and glycerol dioleate (55~ to 45~ by weight) were added 30.92 grams boric acid and 250 mls. of xylene. The reaction mixture was heated at 99 to 141C for about nine and one-haif hours under nitrogen at azeotropic conditions. 17.6 mls. of water were collected by a Dean Stark trap. ~he reaction product was filtered and stripped on a roto evaporator under vacuum to 135C to yield 128.35 grams. Analysis: boron 2.42~ and 2.52% hydroxyl number 32 mg KOH/gmO Infrared spectroscopy analysis of the product shows no free , glycerol-type hydroxyl stretching but does have strong BO-H bond and virtually no B-O~B-type absorption.
oS Example 2 The compositions of this invention were tested in a laboratory test~ The test was carried out on an SAE
No. 2 friction machine modified by adding a moderate-speed hydraulic motor drive. The test specimen was a sandwich of one General Metals Powder Co. 1500 mix sintered bronze plate between two steel spacer plates mounted in the above apparatus, The test fluidj about 300 grams in quantity, was then charged to the t~st-oil sump~ The hydraulic drive rotated the test specimens at 100 rpm~ A piston-like brake was applied at an apply pressure of 75 psig.The SAE No. 2 load cell measured the braking torque and an electric tachometer measured rpm. An x-y plotter was used to produce a trace of torque versus rpm as the hydraulic drive was slowly adjusted to decrease the speed to 0 rpm.
The brake chatter performance of a fluid is related to the slope of the friction VSr velocity curve- The slope of the curve is found by measuring the slope of a line drawn through the 50 rpm point on the trace and the highest point on the trace below 50 rpmO As the slope of this curve becomes increasingly negative, the brake chatter noise becomes progressively louder. This tendency correlates with full scale tractor brake noise tests.
The above described test was run on three mineral oil based tractor hydraulic fluids. The results or these three fluids are shown in Table I. Composition A was a base without a friction modifier and composition contains in addition 1~ borated glycerol monooleate of Example 1. Composition C is a commercial~tractor hydraulic fluid. As shown in Table I, the addition of borated glycerol monooleate (Fluid B) to the base fluid (Fluid A) increased the slope indicating it is effective in reducing brake chatter. Also shown in Table 1 is the slope obtained with a commercial tractor hyraulic fluid.
~0 5~
. TABLE I
Effect of Borated Fatty Acid Ester 05upon Laboratory Brake Chatter Simulation .Slope of Friction Formulation Velocity Curve ... .. . .. . .. . . _ _ A - base oil -.0131 B - base oi7 ~ 1% by . -.0092 weight Borated glycerol oleate of Example 1 C - Commercial Formulation-.0143 .
,
Claims (12)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. In a lubricating oil formulated for use in a tractor and contacting the surfaces of oil-immersed disc brakes, the improvement which comprises including in said formulated oil about 0.1% to about 5% by weight of a borated fatty acid ester of glycerol.
2. The lubricating oil formulation according to Claim 1 wherein the borated fatty acid ester of glycerol is borated glycerol oleated.
3. The lubricating oil formulation according to Claim 2 wherein the borated fatty acid ester of glycerol is a mixture containing from 45% to 55% by weight of borated glycerol monooleate and 55% to 45% borated glycerol dioleate.
4. The lubricating oil formulation according to Claim 2 wherein the borated fatty acid ester of glycerol is borated glycerol monooleate.
5. A method for reducing oil-immersed disc brake chatter by lubricating the contacting surfaces of oil-immersed disc brakes with a composition comprising a lubricating oil containing from about 0.1% to about 5% by weight of a borated fatty acid ester of glycerol.
6. The method of Claim 5 wherein the borated fatty acid ester of glycerol is a borated glycerol oleate.
7. The method of Claim 6 wherein the borated fatty acid ester of glycerol is a mixture containing from 45% to 55%
by weight of borated glycerol monooleate and 55% to 45%
borated glycerol dioleate.
by weight of borated glycerol monooleate and 55% to 45%
borated glycerol dioleate.
8. The method of Claim 6 wherein the borated fatty acid ester of glycerol is borated glycerol monooleate.
9. A lubricating oil formulation for use in contacting the surfaces of oil-immersed disc brakes including from about 0.1% to about 5% by weight of a borated fatty acid ester of glycerol.
10. A lubricating oil formulation according to Claim 9 wherein the borated fatty acid ester of glycerol is a borated glycerol oleate.
11. A lubricating oil formulation according to Claim 10 wherein the borated fatty acid ester of glycerol is a mixture containing 45% to 55% by weight of borated glycerol monooleate, and from 55% to 45% by weight of borated glycerol dioleate.
12. A lubricating oil formulation according to Claim 10 wherein the borated fatty acid ester of glycerol is borated glycerol monooleate.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US30453481A | 1981-09-22 | 1981-09-22 | |
| US304,534 | 1989-02-01 |
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|---|---|
| CA1190540A true CA1190540A (en) | 1985-07-16 |
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ID=23176934
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000409208A Expired CA1190540A (en) | 1981-09-22 | 1982-08-11 | Method for reducing brake noise in oil-immersed disc brakes |
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|---|---|
| JP (1) | JPS5865791A (en) |
| AU (1) | AU548965B2 (en) |
| BE (1) | BE894454A (en) |
| BR (1) | BR8205361A (en) |
| CA (1) | CA1190540A (en) |
| DE (1) | DE3233347A1 (en) |
| DK (1) | DK162656C (en) |
| FR (1) | FR2513260B1 (en) |
| GB (1) | GB2106133B (en) |
| GR (1) | GR70367B (en) |
| IT (1) | IT1153734B (en) |
| MX (1) | MX7570E (en) |
| NL (1) | NL8203590A (en) |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4961868A (en) * | 1983-01-10 | 1990-10-09 | Mobil Oil Corporation | Grease composition |
| EP0135932B1 (en) * | 1983-09-28 | 1990-05-02 | Hitachi, Ltd. | Lubricant for metal forming and process for metal forming |
| DE3485789T2 (en) * | 1984-02-06 | 1992-12-24 | Mobil Oil Corp | FAT COMPOSITION. |
| US5084194A (en) * | 1984-03-07 | 1992-01-28 | Mobil Oil Corporation | Grease composition |
| CA1280738C (en) * | 1984-03-07 | 1991-02-26 | Andrew Gene Horodysky | Grease composition containing boron compound and hydroxy containing soap thickener |
| US4780227A (en) * | 1984-08-22 | 1988-10-25 | Mobil Oil Corporation | Grease composition containing borated alkoxylated alcohols |
| JPH0631381B2 (en) * | 1985-06-13 | 1994-04-27 | 石川島播磨重工業株式会社 | Anti-rust oil |
| US4828734A (en) * | 1985-08-27 | 1989-05-09 | Mobil Oil Corporation | Grease compositions containing borated oxazoline compounds and hydroxy-containing soap thickeners |
| JP4898504B2 (en) * | 2007-03-19 | 2012-03-14 | 香港塔祈巴那電器有限公司 | Fever code |
| GB201502002D0 (en) | 2015-02-06 | 2015-03-25 | Castrol Ltd | Uses and compositions |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3117089A (en) * | 1961-02-10 | 1964-01-07 | Standard Oil Co | Compositions of matter having anti-rust properties |
| CA1164008A (en) * | 1980-03-24 | 1984-03-20 | Andrew G. Horodysky | Borated glycerol and thioglycerol hydroxyester friction reducing additives and lubricant compositions containing same |
-
1982
- 1982-05-15 GB GB08226296A patent/GB2106133B/en not_active Expired
- 1982-08-11 CA CA000409208A patent/CA1190540A/en not_active Expired
- 1982-08-11 ZA ZA825816A patent/ZA825816B/en unknown
- 1982-08-12 AU AU87115/82A patent/AU548965B2/en not_active Ceased
- 1982-09-08 DE DE19823233347 patent/DE3233347A1/en active Granted
- 1982-09-13 GR GR69259A patent/GR70367B/el unknown
- 1982-09-14 BR BR8205361A patent/BR8205361A/en unknown
- 1982-09-15 FR FR8215586A patent/FR2513260B1/en not_active Expired
- 1982-09-16 NL NL8203590A patent/NL8203590A/en not_active Application Discontinuation
- 1982-09-20 SE SE8205370A patent/SE456743B/en not_active IP Right Cessation
- 1982-09-21 JP JP57164791A patent/JPS5865791A/en active Granted
- 1982-09-21 NO NO823187A patent/NO154844C/en unknown
- 1982-09-21 DK DK419382A patent/DK162656C/en not_active IP Right Cessation
- 1982-09-21 MX MX8210289U patent/MX7570E/en unknown
- 1982-09-21 BE BE0/209063A patent/BE894454A/en not_active IP Right Cessation
- 1982-09-21 IT IT23347/82A patent/IT1153734B/en active
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0412319B2 (en) | 1992-03-04 |
| ZA825816B (en) | 1983-06-29 |
| DE3233347A1 (en) | 1983-04-07 |
| NL8203590A (en) | 1983-04-18 |
| DK419382A (en) | 1983-03-23 |
| SE8205370D0 (en) | 1982-09-20 |
| SE8205370L (en) | 1983-03-23 |
| BR8205361A (en) | 1983-08-23 |
| DE3233347C2 (en) | 1992-05-21 |
| NO823187L (en) | 1983-03-23 |
| AU8711582A (en) | 1983-03-31 |
| GB2106133A (en) | 1983-04-07 |
| DK162656B (en) | 1991-11-25 |
| FR2513260B1 (en) | 1986-04-04 |
| GB2106133B (en) | 1985-01-09 |
| NO154844C (en) | 1987-01-07 |
| DK162656C (en) | 1992-04-13 |
| SE456743B (en) | 1988-10-31 |
| JPS5865791A (en) | 1983-04-19 |
| AU548965B2 (en) | 1986-01-09 |
| BE894454A (en) | 1983-01-17 |
| IT1153734B (en) | 1987-01-14 |
| NO154844B (en) | 1986-09-22 |
| IT8223347A0 (en) | 1982-09-21 |
| MX7570E (en) | 1989-11-09 |
| FR2513260A1 (en) | 1983-03-25 |
| GR70367B (en) | 1982-09-29 |
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