CA1039293A

CA1039293A - Lubricant compositions

Info

Publication number: CA1039293A
Application number: CA210,260A
Authority: CA
Inventors: Robert H. Davis; John W. Schick
Original assignee: Mobil Oil Corp
Current assignee: ExxonMobil Oil Corp
Priority date: 1973-10-04
Filing date: 1974-09-27
Publication date: 1978-09-26
Also published as: FR2246551B1; DE2447550A1; AU7404474A; NL7413095A; FR2246551A1; US3897351A; NL175431C; GB1465981A; NL175431B; IT1033101B; JPS5065509A; ZA746217B

Abstract

ABSTRACT OF THE DISCLOSURE
Corrosion inhibitors for lubricants are prepared by reacting a benzotriazole with an alkenyl or alkyl succinic anhydride and then forming the amine salt of the reaction product. The alkanol-amines are preferred for the amines, especially for the preparation of additives for aqueous metalworking lubricants.

Description

1~139~g3 This invention relates to lubricant additlves w-ith ;~
corrosion and oxi.dation inhlbiting properties. It also relates to improved lubricant compositions containing these additives. Such compositions may be lubric:atlng oils, greases, or aqueous-base lubricants.

Certain types of lubricants, including lubricating oils, greases and aqueous-base cutting fluids tend to c~use deterioration by oxidation or corrosion when they come into contact with various metal surfaces. In addition, such lubricants may also undergo deterioration in their intended ~unctlons, for example, :ln load~carrying character:Lstics.
This indicates the necessity for incorporating effective anti-oxidative and corrosion inhibiting a~iditives in such lubricants.

In the machining of metals, for example, cutting, ~rind-ing, turning and milling, it is customary to flood the tool - and the work with a coolant for the purpose of carrying off heat which is produced during the machining. It i~ also customary to employ these coolants in combination with various agents having lubricating and extreme-pressure properties for reducing friction between the tool and work-piece, particularly in operations such as tapping and broaching. In this respect, it has previously been the practice to employ aqueous compo-sitions containing such lubricating agents as emulsified petroleum or non-petroleum àdditives. In order for such aqueous cutting fluids to perform satisfactorily, it is . ~
necessary that residual deposits on the tool and the work following the machining should be avoided. These fluids should ' .~, , j',.` ~., , 'f ~

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also have a tolerance to hard water solutions so that partici-pation oflubrican~ components will not occur and so that tacky residues which interfere with the operat:ion of the machine, as well as excessive foam formation, are avoided.
It has now been found that corrosio~ and o~idation-inhibiting properties can be improved by incorporating, in minor amounts, an amine salt of the reaction product of an alkyl or alkenyl succinic anhydride and a benzotriazole or a substituted benzotriazole. For most applications, these amine salts are employed in an amount of from .001 to 40~, and preferably, in an amount from 0.5 to 10%, by weight, of the total lubricant composition, The present invention, in one aspect, resides in an ; amine salt of a reaction product of an alkyl or alkenyl succinic anhydride and a benzotriazole or alkyl-substituted benzotria-zole, the amine being a long chain amine having from 8 to 30 ~-carbon atoms, an alkanolamine or a tertiary alkyl primary mono-amine with the amino group attached to the tertiary carbon `
atom, the alkyl group having 12 to 24 carbon atoms.
In another aspect, this invention resides in a lubricant composition which comprises a minor proportion of an amine salt of a reaction product of an alkyl or alkenyl succinic anhydride and a benzotriazole or alkyl-substituted benzotria-zole, the amine being a long chain amine having from 8 to 30 carbon atoms, an alknolamine or a tertiary alkyl primary mono-amine with the amino group attached to the tertiary carbon atom, the alkyl group having 12 to 24 carbon atoms, and a major proportion of a lubricant.
In addition to imparting corrosion-inhibiting properties to lubricant compositions, these amine salts are ~` ~ - 2 -.
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~3~Z93 also effective in imparting anti-wear, anti-rust and bactericidal properties. The salts are particularly useful in lubricants which contain a major proportion (at least 50%
by weight) of water.
The additive is an amine salt of a benzotriazole/
succinic anhydride reaction product. The benzotriazole normally used is 1,2,3-benzotriazole but other isomers may also be used. Substituted benzotriazoles, especially alkyl-substituted benzotriazoles such as tolyl triazole may also be employed. -The benzotriazole is reacted with an alkyl or alkenyl succinic anhydride. The alkyl or alkenyl group on these anhydrides preferably contains at least 6 carbon atoms, normally 6 to 50 carbon atoms, with 12 to 30 being preEerred. ;~

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1`hese compounds may be prepared, as i.s corlventiorlal, by reacting an olefin or olefin polyrner with maleic anhydride. The reaction takes place by addltion, ~ith shifting of the double bond in the unsaturated starting . ~;
material. The unsaturated alkenyl substi.tuent may be hydrogenated to produce an alkyl substituent, when desired.

Examples of various anhydrides may be found ln U.S.
Patent 3,256,187 of Robert H. Davis, issued June 14, 1966.

.. . .
Typical of such` alkyl and alkenylsuccinic anhydrides are octenylsuccinic anhydride, dodecenylsuccinic anhydrideg ~.
polybutenylsuccinic anhydride, polyiso butenyl succinic ;. .
anhydride, hexadecenylsuccinic anhydride, eicosenylsuccinic : anhydride, triacontenylsuccin:ic anhydride and i.saoctadecyl-l succinic anhydride.
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~ 15 The benzotriazole is generally reacted with the anhydride 1 .
;. is a molar ratio of 1:1 to 2:1 (benzotriazole: anhydride), . ..
:. preferably in an equimolecular ratio.
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: The reaction between the benzotriazole and the anhydride . can be conducted at a temperature of from 100 to 150 C, : 20 preferably from 100 to 125 C.
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~i The reaction product of the benzotriazole and the . ~, .. ~ anhydride is then reacted with an amine or a mixture of amines. When the fin~1 amine salt is to be used in an oleophilic composition,the amine is preferably a long c~ain :..... .
25 (Cg-C30, preferably C12-C24) amine such as _-octylamine, . tert.-octylamine, nonylamine, decylamine, dodecylamine, ;
: ~ - hexadecylamine, octadecylamine, octadecenylamine or :~ octaaecadienylamine. Amines o~ this type are avai:Lable : .... ~' , .
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~Q3~3 - commercially as ~he "Arrneell's(trade ~lark~ am:Lnes.
Particularly pre~ferred amines are the tertiary-alkyl primary mono amines in which a prirnary amino group (-NH2) is attached -to a tertiary carbon atorn of a C4-C30, pre--ferably C12-C30, alkyl group. Examp:Les of such amines are tert,.-dodecyl primary amine, tert -tetradecyl primary amine, tert. -pentadecyl primary amine, tert. -hexaclecyl primary amine, tert. -oc~adecyl primary amine, tert.
-eicosyl primary amine, tert. -tetracosyl primary amine, .
tert. -triacontyl primary amine and mixtures of such amines. Amines of this type are conveniently available as "Primene 81R" and "Primene JMT" (Trade marks). Primene 81R is a mixture of primary amines having a carbon atom of a tertiary alkyl group attached to the amino (-NH2) group and containing 12 to 15 carbon atoms per amine molecule.
This mixture contains, by wei~ht, about 85 percent tertiary-dodecyl primary amine, about 10 percent tertiary-pentadecyl - primary amine, and relatively small amounts, i.e , less than "I "
5 percent of amines having less than 12 or more than.l5 carbon atoms. Primene JMT is a mixture of tertiary-alkyl primary amines containing 18 to 24 carbons, having a tertiary carbon atom attached to the -NH2 group, and con-taining, by weight, about 40 percent tertiary-octadecyl primary amine, about 30 percent tertiary-eicosyl primary amine, about 15 percent tertiary-docosyl primary amine, about 10 percent tertiary-tetracosyl primary amine, and a ' small amount, less than 5 percent, other amines as high as ; tertiary-triacontyl primary amine.
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llhe amine ~-actants can be prepared in several ~ays well known to those skilled in t;he art. Speclfic methods ` of preparing the t-alk~l primary amines are disclosed in the Journal of Organic Chemistry, vol.20, page 295 et seq. (1955). Mixtures of such arnines can be made from a polyolefin fraction (e.g.,polypropylene and polybutylene ClltS) by first hydrating with sulfuric acid and water to the corresponding alcohol, convertine the alcohol to alkyl chloride with ammonia, under pressure, to produce the t-alkyl primary amine mixture.

The amines themselves may be either oil soluble or water soluble. If the final amine salt is to be used in an aqueous lubricat,ing composition, the amine is preferably an alkanolamine or a mixture of alkanolamines. Examples of such amines include the mono-, di- and triethanol amines, the iso-propanolamines (mono-, di- and tri-), dimethyl ethanolamine, diethylethanolamine, arninoethyl ethanolamine, " .
N-acetyl ethanolamine, phenyl ethanolamine, phenyl, diethanolamine and mixtures of these materials. Particularly preferred is triethanolamine.

Salt formation occurs readily by reaction between the amine and the benzotriazole/anhydride reaction product at room temperature.

Where the lubricant comprises an oil of lubricating viscosity, the lubricant may comprise many mineral or synthetic oils of lubricating viscosity. In instances where high temperature stability is not a prime requirement, mineral oil at a viscosity of at least llo SSU at lQ0 F.
- (ll.2 cS at 38C) and particularly those falling within the ,.
~ - 5 -11)3~2~3 ~ range from 60 SSU ~o 6000 SSU at 100F. '10 to 1300 cS
at 3~C) is preferabIy employed. In some instances, the lubrican~ may comprise a synthetic hydrocarbon oil either alone or in combina~ion with a mineral oil. Typical synthetic vehicles include: polypropylene glycol, tri-methylol propane esters, neopentyl and pentaerythritol -esters, di-(2-ethyl hexyl) sebacate, di-(2-ethyl hexyl) adipate, dibutyl phthalate, silicate esters, esters of phosphorus -containing a~ids, chain-type polyphenyls, siloxanes, or alkyl-substituted diphenyl ethers.
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The liquid lubricants may also be employed in com-bination with a grease-forming quantity of a thickening agent to f~rm greases. These thickening or gelling agents include salts or soaps, non-soap thickeners, such as surface-modified clays and silicas,--aryljureas- and-calcium salt complexes. - ;
, The amine salts of the present invention are particularly useful in aqueous metal working lubricants.
Oils of this type may contain an emulsified mineral oil ("soluble oils") or they may be based on water or water-based mixtures, e.g. polyglycol/water mixtures.

The soluble oils typically contain a mineral oil, water, one or more emulsifiers and additives such as lubricity ~-~mprovers, corrosion inhibitors, extreme pressure agents ;~
and so forth. Fatty acids are Irequently used as lubricity improvers, petroleum sulfonates as emulsifiers and phos-phorus esters such as tri-cresyl phosphate as e.p. agents.

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These compositiolls are ~t~eque~lt~y pre~a~ed con~ler~ially in the form of concentrates which can be diluted with water when they are required ror use. Soluble oils of this type are described, ~or example~ in U.S. Patents Nos. 3723313, 3723314; 3432434 and 3365397.

Another type of metalworking lubricant to which the amine salt additives of the present invention may be added is the polyoxyalkylene glycol based type. Lubricants of this type contain a polyoxyalkylene glycol or glycol ester. Polyoxyethylene and polyoxypropylene glycols and their esters are the most common materials. The glycol or ester rnay comprise the entire base fluid of the lubricant or it may be present with water, in a major or minor amount. The lubricants based on polyoxyalkylene glycol (or glycol ester) mixtures with water normally contain ~ - l to 50; more generally 2 to 20, percent of the glycol or ;l glycol ester, with water making up the balance of the base ' fluid. Other additives such as lubricity improvers (e.g.
fatty aclds), emulsifiers (e.g. petroleum sulfonatés, ethanolamides), stabilisers, corrosion inhibitors (e.g.
sodium intrite) and extreme pressure agents (e.g. tri-cresyl phosphate) may also be present. Examples of metalworking lubricants based on a glycol or glycol ester are described in U.S. Patent 3,652,411. Water/glycol lubricants are described, ~or example, in DT-OS 1444903 and U.S. Patent 3,374,171.
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Another type Or metalworking lubricant is based entirely ~pon water as the liquid medium. In addition to the water, these lubricants may also contain lubricity improvers, `'' '' ' .
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~L~39Z93 corrosion inh:L~-itors, bactericides, sequ~stering agents (e.g. sodium ED~'A salt), and othcr aclditivcs. Lubricants of this type are descrlbed, for example, in U.S. Patents No. 3256187; 3769214 and 3310ll89.
~' .The corrosion inhibiting properties of the amine salts of the present invention are illustrated in Examples 1 to 4 below, and typical compositions including the salts in subsequent Examples. These Examples are given by way of illustration only.

Example 1 A series of addltlve systems were evaluated, as shown in the follow-i.ng table, in accordance with a well-known galvanic corrosion test (the North American Rockwell test) ~ which employs a bimetallic magnesium/steel couple separated ; 15 by a glass cloth strip and shorted with a three inch wire.
This couple is immersed in a 40/1 test lubricant-coolant solution. After 24 hours, the shorted wire is replaced with microammeter leads and current is measured. ~alues ln excess of 120 microamps are indicative of severe corrosion and cause for lubricant re~ection.

As will be seen from the comparative data of the table typical formulations considered unsatisfactory for non-ferrous metal machining are represented by Examples 1, 2 and 3. ~n Example 1 there is employed a 43%, by weight,aqueous triethanolamine solutlon, which is found to stain magnesium and results in a 295 microamp current reading. If the amine is either reacted with the tetrapropenylsuccinic anhydride or combined with the benzotriazole, as in Examples .. ..
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2 and 3 respectively, the eurrent values still exceed 120 mi.croamps. However, if the triethanolamine is.combined with a tetrapropenylsuccinic acid/benzotriazole reaction product, the junction corrosion test results dropped to 62 microamps, as shown in Example 4, thi.s indicates that . .
this additive system is considered satisfactory for machining a non-ferrous metal such as magnesium without corrosion problems associated with steel contact on the machine tool.

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~ : ~ n Example 5 lQ39Z93 Tetraproperlyl s~ccinic anhydride (26 g., 0.1 mol) ;
is reacted w:Lth benzotriazole (12 g.,0.1 rnol) in butyl cellosolve solvent at a temperature of 100-]20 C. The reaction product is then reached with tri-ethanolarnine ~12 g., 0.1 mol), after which the amine salt separates out on cooling and is filtered off. In an alternative procedureg the intermediate reaction product is separated by cooling and filtration, after which it is dissolved in the liquid tri-ethanolamine.

Example 6 ; .
Example 5 is repeated, except that iso-octadecyl succlnic anhydride is used (35 g., 0.1 mol).
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` Example 7 . ~, .
;, Example 5 is repeated, except that the amount of the ~ 15 . benzotriazole is doubled to 24 g., 0.2 mol.
.~ . , ~ Example 8 ; Tetrapropenyl succinic anhydride (52 g., 0.2 mol) is ; dissolved in butyl "Cellosolve"* at 120C and benzotriazole (25 g., 0.21 mol) added in portions over 30 minutes. After cooling, Primene JMT (60 g., approx 0.2 mol) the Primene ' ' 'i ~
--i JMT salt separates on cooling.
: ' ExamDle 9 :. .
Example 9 is repeated, except that Primene 81R (.35 g~, approx 0.2 mol) is added to form the Primene 81R salt ~i` 25 which separates on cooling.

Example 10 A soluble cutting oil is prepared from the following .. ..
constltuents:

~ ~ ~ * Registered Trademark. Butyl "Cellosolve" is ethylene ; ~` glyc~l m~no'~uty ether.

~39;i~13 (1) Wt.percent ~ Mineral oi` r~ . 60 Mineral oil Bt2) 5.40 Lauroyl diethanolamide 2.00 Fatty acids, mixed, C14 - C18 9.00 Petroleum sulfonate, sodlum salt 2.00 Amine salt of Example 8 2.00 Tri-cresyl phosphate 2.00 Wat$r balance 10 Notes (1) Naphthenic oil, viscosity 20cS at 38C
(2) Solvent refined paraffinic oil, viscosity 20cS at 38C
All ingredients are co~bined with about one third of the water and mixed for one hourg after which it may be passed through a Manton-Gaulin homogenizer for a further hour.
After cooling, the remainder of the water may be added.

Example 11 _ A soluble cutting oil is prepared as follows:' Wt.percent Mineral oil A 9-00 Mineral oil B 6.oo Lauroyl diethanolamide 2.00 Fatty acids, mixed, C14-C18 9.00 Petroleum sulfonate,sodium salt 2.00 Amine salt of Example 9 2.00 Tri-cresyl phosphate 2.50 Water balance This lubricant may be made up as described in Example 10.

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'l A polyglyco:l base lubrlcant is made up as follows:

(1) Wt.pe cent '~
. Polyglyccl 93 Phenyl-1-naphthylamine 3.00 ' Tri-cresyl phosphate 2.00 Amine salt of Example 5 2.00 :
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Note (l)-Reaction product of propylene oxide and trl-methylol , 10 propane MW.approx 3,000.

' Example 13 A water/glycol metal working lubricant is f'ormulated as follows:
Wt. percent Polyglycol Amine salt of Example 5 6 ~' Water 86 Note (1) Propylene oxide/ethylene oxide copolymer, hydroxyl 20 numbe,r 22-38.
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Example 14 A water/glycol metalworking lubricant is ~ormulated as . follows.
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:: ' Wt percent : 25 Polyglycol 12 Amine salt of Rxample 5 5 , Parachloro-meta-cresol(biocide) Water 82 . ~ ,.
: . .

Claims

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. An amine salt of a reaction product of an alkyl or alkenyl succinic anhydride and a benzotriazole or alkyl-substituted benzotriazole, the amine being a long chain amine having from 8 to 30 carbon atoms, an alkanolamine or a tertiary alkyl primary mono-amine with the amino group attached to the tertiary carbon atom, the alkyl group having 12 to 24 carbon.
atoms.

2. A salt according to claim 1, in which the reac-tion product is produced by reacting the anhydride with the benzotriazole in a mole ratio of from 1:1 to 1:2.

3. A salt according to claim 2, in which the anhydride and the triazole are reacted in a mole ratio of 1:1.

4. A salt according to any of claims 1 to 3, in which the alkenyl succinic anhydride is octenyl succinic anhydride, tetrapropenyl succinic anhydride, polybutenyl succinic anhydride, iso-octadecyl succinic anhydride or triacontenyl succinic anhydride.

5. A salt according to any of claims 1 to 3, in which the amine is a tertiary alkyl primary mono-amine with the amino group attached to the tertiary carbon atom, the alkyl group having 12 to 24 carbon atoms.

6. A salt according to claim 1, in which the amine is an alkanolamine.

7. A salt according to claim 6, in which the alkanolamine is triethanolamine.

8. A salt according to claim 1, in which the anhydride/benzotriazole reaction product is produced by react-ing the anhydride with the benzotriazole at a temperature of from 100° to 150°C.

9. A salt according to claim 8, in which the temperature is from 100° to 125°C.

10. The triethanolamine salt of a reaction product of benzotriazole and tetrapropenyl succinic anhydride, the reaction product being produced by reacting the benzotriazole with the anhydride at a temperature of from 100° to 125°C.

11. A lubricant composition which comprises a minor proportion of an amine salt of a reaction product of an alkyl or alkenyl succinic anhydride and a benzotriazole or alkyl-substituted benzotriazole, the amine being a long chain amine having from 8 to 30 carbon atoms, an alkanolamine or a tertiary alkyl primary mono-amine with the amino group attached to the tertiary carbon atom, the alkyl group having 12 to 24 carbon atoms, and a major proportion of a lubricant.

12. A composition according to claim 11, in which the amine salt is present in an amount from 0.5 to 10% by weight.

13. A composition according to claim 11, which includes water.

14. A composition according to claim 13, which is a soluble oil metalworking lubricant.

15. A composition according to claim 13, which is a metalworking lubricant which includes water and a polyoxy-alkylene glycol.