CA1037939A

CA1037939A - Combination of naphthols sulfonates and non-metallic detergents as rust inhibitors

Info

Publication number: CA1037939A
Application number: CA220,838A
Authority: CA
Inventors: Albert L. Williams; El-Ahmadi I. Heiba
Original assignee: Mobil Oil Corp
Current assignee: ExxonMobil Oil Corp
Priority date: 1974-05-30
Filing date: 1975-02-26
Publication date: 1978-09-05
Also published as: AU498950B2; GB1472142A; ZA751282B; JPS50159432A; NL7506184A; US3897350A; BE829011A; IT1038401B; DE2523774A1; AU8172975A; FR2275548A1

Abstract

RUST INHIBITORS

ABSTRACT OF THE DISCLOSURE

Lubricating and hydraulic oils are provided rust inhibition by the presence of a mixture of (1) 1-naphthol or 2-naphthol or nitroso derivatives thereof and (2) an alkaline earth metal or Group IIB metal sulfonate. The effect of this mixture is further enhanced by the presence in the oil of a non-ash forming nitrogenous or ester dis-persant such as alkenylsuccinimides, alkenylsuccinic esters, including esters of polyhydric alcohols, alkyllactam amides and the like, each having a long-chain hydrocarbyl group of from 20 to 300 carbon atoms.

Description

BACKGROUND OF T~E INYENTICN

FieId of the In~ention , This invention relates to lubrica-ting and hydraulic oil compositions having improved rust inhibition and in particu- -lar to oil compositions containing a mixture of oil additives.
Prior Art of the Invention A desirable function of lubricating oils used in auto- ;`
`~` motive, marine, railroad or other engines is the ability to ``
prevent rust of the metal parts. Often moisture, usually -condensed from the atmosphere, is present in engines and other machinery, causing rust. Certain oi1 additives have been used as rust preventors or inhibitoxs, particularly the metal ;~
- sulfonates, both neutral and overbased complex sulfonates.
Reference to U. S. Patents 2,616,911, 2,721,843, 2,739,124,

2,856,360, 2,861,951, 3,658,703, and 3,155,616, and other patents of that classification indicate typical preparation of ~ `
the overbased metal sulfonates. `
U. S. Patent 3,634,241 discloses sulfonate salts of alkenylsuccinimides. U. S. Patent 3,219,666 discloses ~ ~
20 preparation of dispersants from alkenylsuccinic anhydrides -~ -and amines and the use thereof in oils along with basic sulfon- ~`
ates promoted by alcohols or phenols. As indicated in U. S. Patent

3,488,284, preferred promoters are alcohols which do not contain `- ~;
a benzenoid ring. -~ ~
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U. S. Patent 2,691,634, U. S. Patent 3,492,234 and -~
U. S. Patent 3,554,945 disclose oil compositions containing naphthols or polyhydroxy naphthalenes as either flow additives or antioxidants.

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~, SU~MARY ~F THE INV~NTION
It has now been discovered that a lubricating or hydraulic oil composition containin~ in admixture'a l-naphthbl ' - or 2-naphthol or their nitroso-subsl:ituted counterparts and a ;~
Group II metal sulfonate possesses exceIlent anti-r~st proper-ties. In addition, the presence in the said oil composition of a long-chain hydrocarbyl-substit~lted condensation product, - useful as a detergent, of either an alkyl substituted lactam - or lactone amide or an aIkenylsuccinimide or alkenylsuccinic - 10 ester of an alkyl-sUbstituted Mannich base further improves the rust inhibiting characteristic. -~
The present invention provides an oil composition ;~
- comprising a lubricating oil medium and (1) from about 0.3% ~ ;
to about'5% by weight of a naphthol selected from the group '~' consisting of l-naphthol, 2-naphthol and 1-nitroso-2-naphthol; (~) from about 0.5% to about 10% by weight of a sulfonate of a metal selected from the metals of Group II of the Periodic Classification; and (33 from about 0.5% to about 10% by weight of a long-chain hydrocarbyl-substituted organic condensation product having 20 to 300 carbon atoms in the '~
hydrocarbyl group, said product being an ester of an alkenyl-succinic anhydride and an alcohol having 1 to 4 hydroxy groups. ~`
DESCRIPTION OF SPECIFIC EMBODIMENTS
This invention contemplates the use of lubricating oil or hydraulic oil compositions having excellent rust rating.
The oil compositionS are useful for purposes as gear oils, l~ ;
turbine oils, hydraulic oils and greases and the like. Any !
; hydrocarbon oil, either synthetic hydrocarbon or petroleum-based oil and ester oils, may be usea. : -~
One'component of the composition is a l-naphthol or 2-naphthol or the nitroso derivative'thereo'f. Alkyl-substituted ~
naphthols or phe`nols do not exhibit the performance'provided by ~`-~ -3-r:. . . ~ , ' ' '"' ` ' ' ~ , 7~ 9 th~ aforesaid compounds.
The second component is the metal-sulfonate. These organosulfonate additives are weIl known in the art. Generally they are Group I~ metal salts, such as barium, strontium, calcium, magnesium and z nc. Neutral sulfonates are`readily prepared by reacting a metal oxide or hydroxide with the sulfonic acid. Methoas of increasing the metal content to .... . , :
3~

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produ~ overb~sed ~ulfonates include treating the reactlon mixture (containlng excess metal oxide or hydroxide) wlth carbon dioxide. Carbonate-sulfonste metal complexe~ ~re formed. (U.S. Patents 2,956,-018, 3,027,325, 3,03.6,971 and 3,158,572 show these and other methods of preparing these sulfonate complexes). The preferred sulfonic acid has the formula R ~ 53 or alkylbenzene sulfonates, wherein R representæ one or more alkyl groups. R may contain from 8 to 50 carbon atoms, preferably 8 to 30 carbon atoms. ~ax benzene sulfonic acids, :~
octadecyl sulfonic acid, and mixed cl4 to C24 alkylbenzene sulfonic acids are preferred. The metal content of the resulting salts may contain over 200% excess metal (as in U.S. Patent 3,436,347).
The specific manner of preparing the neutr~l or overbssed metal sulfonates used herein is not within the scope of this inventlon.
The naphthol and sulfonate may be present in the oil composition at concentrations ranging from sbout 0.3%
to 5% by weight of~naphthoi and from about 0.5% to sbout 10%
by weight of sulf~nate. This admixture of these additives provide a synergistic response ~n the rust rating tests for oils.
The additional component wh~ch may also be present if desired may be st least one of the following:

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-- (i) alkenyl~ucClnlmldes (2) alkenyl6ucclnic ester~
(3) alkyll~ctone or alkyllact~m ~mldes

(4) reaction product of alkylphenol~ an aldehyde and an amine, termed "Mannich bas~
These products have known detergent propertie~ Their utility in this invention is desirable, ln part, becsuse o~ the long~
chain alkyl or alkenyl groups attached to the molecule~
These hydrocarbyl groups contain from 15 to 300 carbon atoms. `~
Preparation of such products is known ~n the art. ~-~
U.S. Patent 3,172,892 describes a procedure for preparing alkenylsuccinicimides from the alkenylsuccinic anhydride ~nd ethylene polyamines. Mono-~mides and bis-imides may be prepared by providing sufficient anhydride to foxm either a `~
single imido group at one H2N- group or two imido groups at both H2N- groups of the polyamine. Tetraethylenepentamine ;
i8 the preferred amine, althoughother amines of the formula H2N(C2H4NH)n-C2H4NH2~ wherein.n i8 0 or an integer of 1 to ~
lO, may be used. ~-Alkenylsuccinic esters are prepared by reacting - the acid or anhydride with mono or polyhydric alcohols, of 1 to 4 hydroxy groups such as methanol, ethanol, butanol~ --octanol, decanol, dimethylpropanol, dlmethylpropanediol, trimethylolprop~ne, trimethylolbutane, pentaerythritol and ~ipentaerythritol. Typical preparation of these esters ls -disclosed in U.S. Patent 3,381,022. The polyesters are the pre-ferred class of additi~es.

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The ~yllactone or alkyllactam amldes are prepared by reactin~ ~n Rl~en~lsuccinic anhydride, pre~erably obtained by reactin~ a po~ybutene or polyisobutylene with maleic an-hydride, wit~ ~n ~lcohol or by sub~ectin~ the anhydrlde to acid hydrol~Si~, lllustrated as follows:

~
R'-CH=CH-CH2 ~ CH - C
~ ~0 + (HO)x-R" cat.
CH2--C~
lC
R~-~H~ - CH - CH2 0 "
O CH-CH2-C-OR~ ~
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wherein R~ 1~ the r~t of the alkenyl group and either R " is hydrogen an~ x i~ 1 or R" is alkyl or aralkyl or alkylene or arylalkylene ~n~ x ls from 1 to about 4. The catalyst i~ an acid such aB h~rochloric acid when R" is hydrogen~ or a sul~onic acld l~n exch~nge resin. The resulting lactone acld or lactone ester :i~ reacted with the ethylene polyamine to produce the la~one am~de. I~ the reaction ijs carried out ~t sufficient temperature to replace the oxygen in the lactone ring? the la~tam amide forms. Bis-lactam amides and even polymers may ~ so produced. Such compounds may have the formula `' ' . ' ' ' ' .

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.~_ Rl-CH~-fH_fH2 o~ ,~CH-CH2- -NH( c2H4NH)nc2H4 and ~ . . '` ' ' Rl-CH2-CH--C~ 2 CH-CH2-d-NH(~H4NH) ~N-C2H4(HN~C2H4)n j~

the dangling valences being hydrogen or a repeating segment.
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The Mannich bases also use~ul in this inven~ion are prepared by the procedure disclosed in U.S. Patent 3,368,972.
The preferred bases are those of polypropylphenol h&v~ng 20 to 300 carbon atoms in the alkyl chain, formaldehyde (or paraformaldehyde) a~d tetraethylene pentamine. Other mono or polyamines are ~uitable but TEPA provides desirable basicity `
for neutralization, and is readily available.
These non-ash-forming detergent~ are-pre~en~ in the oil composltions in concentrations of from about 0.5~ to - . .. .
about 10% by weightc Other additives may be present in the lubricating oil compositions o~ this invention to provide antioxidant properties, viscosity index lmprovement and the like.
Examnles ~
The ~ollowing examples are lubricant compositions ~ ~i -sub~ected to rust rati~g tests and utilize dl~ferent ~nown addlt~ves. -- . , - :
In each example, the oil i~ a Mid-continent sweet base oil of 5.38 c~ viæcosity at~210F. The ldentity o~ the additlves is as follows~

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(1) Neutral_Sulfonate - a commercl~l neutral c~ m alkylbenzene sulfonate, cont~lning 1.45~ by weight of c~lcium flnd 2% by weight of sul~ur; molecular weight of the RS03 group, about 700; total b~se number (TBN), 7 mg KOH
per gram Or materi~l (product is designated as "Lubrizol OS
No. 16938"*, a product of The Lubrizol Corporation).

(2~ SucciniC Ester - a reaction product of polyi8 butenylsuccinic anhydride of about 2300 molecular weight and pentaerythritol.

(3) Bis-imide - a reaction product of about 2 moles of the polybutenylsuccinic anhydride of about 1000 molecul~r weight and one mole of tetraethylenepentamine.

(4) Overbased Sulfonate - a commercial overbased calcium alkylbenzene sulfonate, containing about 12~ by weight of calcium and 1.6% by weight of sulfur; molecular weight o~ the RS03 group is 385; TBN, 300 (product is design-fl,ted as ~Lubrizol 690"**, a product of The Lubrizol Corporation).

Other ~dditives used herein are designated b~ j their chemical names.
The test procedure is a modification of ASTM D1748.
In the present test, Oldsmobile steel push rod sections 4 3/4 inches long (half a rod) are dipped into the test oil~ allowed to drain and suspended in a humidity cablnet at 60C. for 22 ~
hour~, with redipping every 40 minutes. This procedure ~;
measures the relative ability of the various oil compositions to prevent rusting of steel under high humidity acidic con-ditions.
The operating conditions and specific procedure of the humidity cabinet te~t are Bs follows:

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~ " Duratlon of test 22 hours Air temperature 60C.
; Volume of cabinet 52 liters Rate of air to cabinet 12.5 liters/hr.
Rate of nitric oxide to cabinet 25 ml./hr Water level in cabinet ~ in.
Frequency of dipping in oil 1.5 per hr.
10 The push rods are held inside the cabinet in an air-plus-nitric oxide stream with complete immersion in test oil every 40 minutes for 10 seconds. At the end of the test the rods are removed from the cabinet, washed in CRC solvent (40%
ethylacetate, 30~ methanol, 5% butylalcohol, 25~ orthodichlo~
15 benzene) to remove any oil and examined for rust. The rating is similar to that o~ the Coordinating Research Councills rust rating on the scale of 1.0 to 10.0, as given ln CRC Manual No. 7, 1.0 corresponding to heavy ruBt all over the specimen, 10.0 corre6ponding to a completely unblemished rod. A rating 20 in this pre~ent test of 5.Q`is a pass, above 5.0 is good to excellent, below 5.0 is failure.
: Conc. Rust Test No. Oil Composition Wt.% Ratin~
. , 1 Oil Alone - 1.0 2 Neutral Sulfonate 2.5 1.0 - Succinic Ester 4.0 .- ~ . .
3 2-Naphthol 2.0 1.0 4 l-Naphthol 2.0 1.0 2-Naphthol 0.5 4.5 30 - Succ~nic Ester 5.5

6 2-Naphthol 0.5 5 0 Neutral Sulfonate 5.5 .. ~ . ' ' '.

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~U~ 39 Conc. Ruat Test No. Oil Composition Wt.

7 2-Naphthol o 5 Neutral Sulfonate 2.0 7.9 Succinic Ester 3.5

8 l-Naphthol oO5 Neutral Sulfonate 2.0 5.5 - Succinic Ester 3.5 - These results show that at a total concentration o~ 6.5, the neutral sulfonate and the ester together provide almost no rust protection, as does either naphthol alone or with ester.
The naphthol with the sulfonate has a passing rating. However~
the same three components at indivldual concentrations below that prevlously used do provide unexpectedly higher ratings, The same sulfonate and ester used in Tests Nos. 7 and 8 were tested at the same respective concentrations in . . .
formulations with other hydroxyaromatic compounds, such as alkylated naphthols~ phenols,dihydroxyphenolsand the like.
All fsiled to meet the CRC standard rust rating o~ 5,0, Conc Rust Test No. Oil Compositions Wt.~ Ratin~
Neutral Sulfonate 2.0 Succinic Ester ~.5 Hydroxyaromatic:

9 Dihexyl-2-naphthol- l.l l.O
Didodecyl-2-naphthol 1.67 l.O
ll 2,5-Di-t-butyl-hydro-quinone l.O l.O
12 3,5-Di-t-butyl-catechol l.O 3 6 .
.

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~f~7 ~ 3 9 Conc. Ru~t ~~est No. 011 Composition Wt.%
-13 4~6-Di-t-butylresorcinol 1.0 1.0 14 p-Octylphenol 1.0 1.0 4~4'-Methylenebi~(2,6-di~
t-butylphenol) 1.0 1.0 Several of the above hydroxyaromatic compoundsa particularly the bisphenol of ~est No. 15~are known anti-oxidants for oil compositions, yet they fail in this rust tes,t.
Oil compositions containing the bis-imide also - indicate synergism:

, Conc, Rust Test No. Oil Composition Wt.%
1 . Oil Alone - - l.Q
15 ~ ' Neutral Sulfonate 2.5 1~0 , Bis-imide 4.0 ' 3 2-Naphthol 2.0 1.0 17 '2-Naphthol o.5 Neutral Sul~onate 2.0 6,8 , Bis-imide 3.5 Use of an overbased calcium sulfonate does not significantly improve the rust rating with the succinic~
alone. Again, the naphthol must be present: ' Conc. Rust Test No. Oil Composition Wt.% Ratin~
- 1 Oil Alone , - 1.0 18- O~erbased Sulfonate ' 1.5 2 2 ' Succinic Ester 4.0 3 2-Naphthol , 2.0 1.0 19 2-Naphthol 5'' 5 8 Overbased Sulfonate 1.0 , 20 2-Naphthol 0.5 ' Overbased Sulfonate 1.0 9.7 ` Succinic Ester 3.~
, . . .
. . .
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` _ ~ ~7 ~ ~ 9 ConcO Rust TLsT ~~o. Oil Compositions Wt.~ Ratin~
21 1-Nitroso-2-naphthol 0 5 Overbased Sulfonate 1 0 7.2 Succinic Ester 3.5 4 l-Naphthol 2.0 1.0 22 l-Naphthol 1.0 Overbased Sulfon~te 1.0 7.8 Succinic Ester 3.5 The aboue series of tests show that naphthol and over-based sulfonate together provide acceptable rust protel:tion~
- Test No. 19 resulted in a rust rating of 5.8 at a tot~l concentration of only 1.5~. Although the succinlc estl~r pro-vided little additional rust protection to the sulfonote in Test No. 18, the rating of this combination increased 1;o 9-7 with the presence of 2-naphthol in Test No. 20. The 1~nitr~-.. . : .
2-naphthol in Test No. 21 is not suf~lcien~ly soluble ln oil to use alone as a rust preventive agent. However, wittl the sulfonate-eQter combination, a very good rating was Ob~ained.
The formulations of this invention are of p~rticu1ar interest in hydraulic oils. The likelihood of moistur~ in th~
oil system is ever present and, thus, the danger of rU~5 of metal parts is significant. The presence of naphth~l and sulfonate in the formulation could provide the necessu~Y pro-tection. I~ the imide or ester detergent is also pre~
such results as achieved in -Test No. 20 could be impar~
to a hydraulic oil formulation.

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Claims

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

1. An oil composition comprising a lubricating oil medium and (1) from about 0.3% to about 5% by weight of a naphthol selected from the group consisting of 1-naphthol, 2-naphthol and 1-nitroso-2-naphthol; (2) from about 0.5% to about 10% by weight of a sulfonate of a metal selected from metals of Group II of the Periodic Classification; and (3) from about 0.5 to about 10% by weight of a long-chain hydrocarbyl-substituted organic condensation product having from 20 to 300 carbon atoms in the hydrocarbyl group, said product being an ester of an alkenylsuccinic anhydride and an alcohol having 1 to 4 hydroxy groups.

2. The composition of claim 1 wherein the metal sulfonate is a neutral sulfonate.

3. The composition of claim 1 wherein the metal sulfonate is an overbased sulfonate.

4. The composition of claim 1 wherein the metal is calcium.

5. The composition of claim 1 wherein the ester is a polyester of a polybutenylsuccinic anhydride and pentaery-thritol.

6. The composition of claim 1 wherein there is present at least 1% by weight of an overbased calcium sulfonate and at least 3.5% by weight of a polybutenylsuccinic ester of pentaerythritol.

7. The composition of claim 1 wherein the naphthol is 1-nitroso-2-naphthol and the sulfonate is an overbased calcium sulfonate.

8. The composition of claim 1 wherein the lubricating oil medium is a hydraulic oil or turbine oil.