DE2437842A1 - LUBRICANT ADDITIVES - Google Patents

Description

PATENT ANWXLTE

DR. K WIEGAND DiPL-ING. W. NIEMANN O / Q 7 Q / O

DR. M. KÖHLER DIPL-ING. C. GERNHARDT LHO IO ^ £

MÖNCHEN HAMBURG

TELEPHONE: 55547 «8000 M ö N C H E N 2,

TELEGRAMS: KARPATENT MATH I LDENSTRASSE 12

TE L E X: 529 008 CARPD

August 6, 1974

W 42 οδό / 74 7 / az

Mobil Oil Corporation New York, N.Y. (V. St. A.)

Lubricant additives

The invention relates to lubricant additives and to lubricating oils and greases having improved properties against wear and friction.

It is known that certain types of lubricant compositions, in particular oil of lubricating viscosities and »greases usually have poor properties against wear show and improve during the course of their duration of action to codify friction, and in this regard it has previously been suggested that certain Phosphoric acids to improve the properties of lubricants should be used. For example, tricresyl phosphate is a well-known anti-wear agent, especially in synthetic ones Ester fluids for aircraft. The usage

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of certain acid phosphates in lubricants is in the U.S. Patent 3,116,284; 3,116,249; 2,728,728; 2 8ol 963 and 2 285 853. The use of different phosphites or phosphonates, as they are variously referred to, is disclosed in U.S. Patents 3,115,466; 2 824 131 and GB-PS 899 lol.

The use of amine salts of mixed phosphoric acids is also earlier in the US patents 2,674,616; 2,874 12o; 2,838,332 and 3,634,239 have been proposed. In Canadian patent 668 7 35 is the Use of Iirddazoline phosphate salts described.

It has now been found that the alkylamine and Imidazoline salts of certain acidic long chain alkyl phosphonates Improvements in the anti-wear properties and the frictional properties of lubricating oils and -delivery of greases.

These salts are (a) an amino or an imidazoline containing a straight chain aliphatic group having 12 to 22 carbon atoms and (b) an acidic phosphonate with an alkyl group and a long chain alkyl group C, ₂ to C derived _22nd

The phosphonates that are reacted with the amines and imidazolines are acidic phosphonates of the general type formula

r:

R P = O,

OH

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in which R is a long-chain alkyl group having 12 to 22, preferably 18 carbon atoms, and R ^{1 is} a lower alkyl group (C ₁ -C 1), preferably methyl. The preferred acidic phosphonate is a kethyloctadecyl acidic phosphonate of the formula

^C l8 ~ ^H 37 '

OMe

P = O ι OH

Acid phosphonates of this type are also called alkyl alkyl phosphonic acids see "Phosphorus and its Compounds", van Wazer, Interscience, N.Y., Vol. I, page 35o.

The salts can be prepared by reacting the phosphonate with the desired alkylamine or imidazoline in stoichiometric proportions. The reaction is usually carried out at ambient temperature, although elevated temperatures can also be used _to accelerate the reaction.

The alkylamine or imidazoline contains at least one straight-chain aliphatic group with 12 to 22 carbon atoms, which can be saturated or unsaturated. The amine can be a primary, secondary or tertiary amine. Specific Amines that can be used are, for example, oleylamine, dimethyloleylamine, n-dodecylamine, n-hexadecylamine, n-octadecylamine, dioleylamine, dioctadecylamine, n-dodecyldimethylamine, n-tetradecyldimethylamine, n-hexadecyldimethylamine or n-octadecyldimethylamine.

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The imidazolines that can be used also contain a long-chain aliphatic (C, ^ Cp group), which can be saturated or unsaturated. Such imidazolines can be prepared by reacting a carboxylic acid with a polyamine, which for the present purposes is preferably a diamine, in particular ethylenediamine. The carboxylic acid provides the desired long chain group, and so acids with C ₂ -C ₂₂ aliphatic groups on the carboxyl groups can be used to make the imidazoline.

A particularly preferred material is 1-hydroxyethyl-2-alkylimidazoline, in which the alkyl group is derived from oleic acid. This material can be obtained by implementing Ethylenediamine with oleic acid to form the imidazoline ring structure and subsequent enrichment of the product with ethylene oxide to generate the hydroxyethyl substituent will.

N - CHp ^C 17 ^H 33 ' ^{COOH 4}

- ⁰ V

_(/ CH ₂ + OH ₂ OH ₂ ^ N - OH ₂

V. , ^ϋ 17 ^Η 33 ° v / HN

Other substituted imidazolines can be made in the same manner using other amines and acids will. For example, diethylenetriamine, triethylene-

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tetraamine and tetraethylene pentamine as amines and stearin-dodecane, Hexadecanoic, linoleic and linolenic acids are used as acids. Because the purpose of the acid is to create the Long-chain alkyl group, which makes the product oil-soluble, can be straight-chain acids with 12 to 22 carbon atoms be used in the chain »The chain can be saturated, as with stearic acid, or unsaturated, as with oleic acid. If the imidazoline is produced from ethyl diamine and therefore contains active hydrogen, it can be Alkylene oxide, preferably ethylene oxide, reacted v / ground, though Propylene oxide can also be used to create a hydroxyalkyl group as a substituent on the imidazoline ring, as shown above.

It has now been found that when the long chain group of the alkylamine or imidazoline is less than 12 carbon contains atoms, little or no improvement in the friction-modifying properties is achieved will. On the other hand, if the alkyl group contains more than 22 carbon atoms, the resulting alkylanine salt is as was found to be less soluble in this lubricant,

The lubricant additives contain a small one Amount of the salt, preferably in an amount of 0.2 to 1.5% by weight and for most applications from 0.4 to 1% by weight, based on the total weight of the composition.

The lubricant compositions can comprise any substances which usually have inadequate properties show against wear or the friction-modified properties require. A specific field of application is the improvement of liquid hydrocarbon oils, which are used in the

509808/1167

Boil range from 23.9 Ms 538 ⁰ C (75 to looo ° F). Mineral lubricating oils improved in accordance with the invention can have a suitable lubricating viscosity range of 45 to 600 SSU at 38 ° C (100 ° F) (5.3 to 1300 OS "at 38 ° C), and preferably from 50 to 25o SSU at 99 ° C C (21o ° F) (7.4 to 5 3 cS at 99 ° C). These oils can have viscosity indices that vary from below 0 to 100 or higher. Viscosity indices from 70 to 95 are preferred. The average molecular weights of these oils can be in be in the range of 25o to about 800. In general, the lubricant can comprise any mineral oil or synthetic oil of lubricating viscosity.

The salts according to the invention can be used as friction modifiers or anti-wear agents including lubricating grease compositions be incorporated. Such greases can be a combination of a wide variety of lubricant carriers and thickening or gelling agents. So can lubricating greases in which the so-called salts are special effective include any of the so-called hydrocarbon oils of lubricating viscosity as oil carriers and may include mineral oils or synthetic lubricating oils, and particularly oils of the types mentioned above. if high temperature stability is not a requirement of the finished grease, mineral oils with a viscosity of at least 4o SSU at 66 ° C (15o ° F) (4.2 cS at 66 ° C) and especially those that are in the range of 66 SSU to 600o SSU at 38 ° C (loo ° F) (Io to 13oo cS at 38 ° C) are used. The lubricant carriers come with a Grease-forming amount of a thickener combined. A wide variety of materials can be used for this purpose. These thickening or gelling agents include

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Metal salts and soaps, soap-like thickeners such as Surface modification concretes and silicas, aryl ureas, Calcium complexes or similar materials. In general v / ground grease thickeners that do not melt and do not dissolve when required Temperature used within a particular environment is preferred.

The following examples illustrate the effect of the new Λlky! Amine salts according to the invention as Lubricant improver with regard to anti-wear and friction modification properties in organic Lubricant masses,

example 1

In the comparative tests of this example, the additive package component comprised by weight zinc dithiophosphate 1%, polymethyl methacrylate 3.3%, aromatic oil swelling agent 2%, kerosene 0.1%, calcium sulfonate 8.6%, synthetic sulfurized sperm oil 3%. In this example and the other examples the base oil comprised a solvent refined, paraffinic base oil was dewaxed to a pour point of- 17.8 ⁰ C (O ⁰ F).

formulation Material,% by weight Trial A Trial B

Base oil '81.75 81.5o

Additive pack 18, oo 18, oo

acidic methyl ^ pctadecyl-

phosphonate o, 25 o, 25 ^

l-hydroxyethyl-2-alkylimida- V +)

zolin of oleic acid ο, οο ο, 25 J

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implemented before meddling

Exam result

SAE wear test 68oGo7, 76 rpm test Λ 68kg (15o lbs.) 1/2 hour

Attempt B

Weight loss, reg

judgement
IHC water tolerance test

14 days with 1% water separation of the additive, l%

failure
in Io min

failure

o, 2

passed

no

The comparative values of the above example illustrate the improved anti-wear and water tolerance properties, given by the alkylamine salts according to the invention.

Example 2

In the comparative tests of this example, the additive package weight comprised same additive package as in example 1, with the exception, that the sulphurized spern oil was omitted.

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■ - 9 -

formulation Material, wt .-%

Grundö1

Additive pack

Acid MethyLiLctadecyI ^ phosphonate

l-hydroxyethyl-2-alkylimidazoline of oleic acid

Experiment A Experiment B 84.5ο

ο, 5ο

ο, οο ο, 25

implemented before meddling

Test results

SAE wear test, 68o6o7, 76 rpm 68 kg (156 lbs.) 1/2 hour

Weight loss, mg
judgement

19th

passed

passed

IHC water tolerance test 1% water

Additive separation after 14 days,

Additive separation after 21 days,

Additive separation after 28 days,

O O o, 6 O o, 8 O

The comparative values of the above example illustrate the improved anti-wear and water tolerance properties imparted by the alkylamine salts according to the invention.

50 9 80 8/1167

- Io -

Example 3

In the comparative tests of this example, the additive packing component, based on weight, comprised zinc dithiophosphate 0.7%, polymethyl methacrylate 3%, aromatic oil swelling agent 2%, kerosene 0.1%, calcium sulfonate 7% *
The John Deere Tractor Chatter Index Test is fully described in U.S. Patent 3,652,410.

formulation Material / Gev /, -%

Base oil

Additive pack

acid methyl oetadecylphosphonate

l-hydroxyethyl-2-alkylimidazoline of oleic acid

Attempt Λ

86.7o

12.8o

o, 5o o, oo

Attempt B

o, 25

implemented before meddling

Experimental results

John Deere Tractor Chatter Index

4-ball wear scar (40 kg, 2 hours, 93.3 ° C 6oo rpm)

, ran (2oo ° F)

184
o, 5o

186 o, 45

The comparative values of the above example illustrate the improved antiwear performance and the equivalent chatter control given by the alkylamine salts according to the invention.

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- li -

Example 4

In the comparative tests of this example, the additive comprised a pack component. based on weight: Polymethyl methacrylate 2.4%, sulfurized isobutylene 1.8%, Polybutylene succinimide of tetraethylpentamine 1%, kerosene o, 75%, Alkyl ester of alkyldithiaphosphoric acid 0.2%, alkyl derivative of 2,5-dimercapto-1,3,4-thiadiazole 0.1%.

Formulation Attempt a Attempt B Material, wt .-% 93.25 93.25 Base oil 6.25 6.25 ADDITIONAL SUBSTANCE FOR PACKAGE o, 5o o, 25] methyloctadecyl acid phosphonate \ ⁺⁾ 1-hydroxyethyl-2-alkylimidazoline from O, OO o, 25y Oleic acid

implemented before meddling

Test results

Precipitation after storage for 30 days at room temperature

strong

none

The comparative values of the above example illustrate the ineffectiveness of the acidic methyloctadecylphosphonate in the form of a free acid with the formation of a precipitate after 30 days.

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Example 5

In the comparative tests of this example, the additive pack component comprised, by weight: Polymethyl methacrylate 2.4%, sulfurized isobutylene 1.8%, Polybutenyl succinimide of tetraethylpentamine 1.0%, alkyl ester of alkyldithiaphosphoric acid 0.2%, dibutylphosphonate 0.4%, Kerosene ο, 75%, alkyl derivative of 2,5-dimercapto-l, 3,4-thiadiazole oil%.

formulation Material, wt .-%

Attempt a

Attempt B

Base oil

Additive pack

acid methyl octadecyl phosphonate

l-hydroxyethyl-2-alkylimidazoline of oleic acid

93.35 6.65

O, OO O, OO

ο, 25

implemented before meddling

Test results

John Deere oxidation test (loo hours at 149 ° C (3oo F

° C (

% Viscosity change at 98.9 ° C (21o ° F)% viscosity change at 38 ° C (loo ° F)

Humidity _{Chamber 48>} 9 ° C (12o ° F) hours to rust

4.30 12.44

2.74 7.41

48

The comparative values of the previous example illustrate the improved performance in terms of oxidative stability and anti-rust properties, which is achieved by the Alkylamiηsalze are granted according to the invention.

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example

In the comparative tests of this example, the additive pack component comprised, by weight: Polymethyl methacrylate 2.4%, polybutenyl succininide of tetraethylpentamine 1.0%, barium sulfonate 1.0%, alkyl esters of aryldithiophosphoric acid 2%, kerosene o.1%.

Formulation material,% by weight

Base oil

Additive pack acid ilethyl octadecyl phosphonate

l-hydroxyethyl-2-alkylimidazoline of oleic acid

Attempt Λ Attempt B 93.5o 93, oo 6.5o 6.5o O, OO o, 25?
V
I +)

O, OO

implemented before meddling

Test results

Humidity Chamber 48.9 ° 0 (12o ° F)

Evaluation after 96 hours of failure

SAE wear test

76 rpm, 68 kg (15o lbs.) Weight loss, mg

Failure at

68kg (15o lbs.)

156 rpm, 4oo lbs. (181 kg) weight loss, rag.

Failure at 81.6kg ■ (18o lbs.)

passed

74

877

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The comparative values of the above example illustrate the improvement in terms of anti-wear and anti-rust performance achieved by the alkylamine salts according to the invention granted.

Example 7

In the comparative tests of this example, the included Additive pack components based on weight: o.7o% of a zinc dialkyldithiophosphate, 3.3o% of a methacrylate polymer viscosity index improver, 2, oo% of a high-boiling aromatic swelling agent, o, lo% of a silicone defoamer solution (in kerosene), 8.6% of an overbased calcium petroleum sulfonate.

The compositions shown below were tested and the results were as follows: (the amine reagent and acidic phosphonate were converted beforehand)

Formulation,% by weight test no »

Base oil 85.3o

Additional material pack 14.7o

acid methyloctadecyl

phosphonate -

Oleyl imidazoline

Oleylamine - - o »20 ~

Dimethylsoyaamine - - - o, 21

84, 8o 84 t 85 84, 84 14, 7o 14th I. 7o 14, 7o O, 25th O I. 25th 25th O, 25th mm around -

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Test results

Experiment no.

Catalytic OxydayLon 40 hours at 163 C (325 ° F), 10 air / hour increase in viscosity at 98.9 ⁰ O

(21o ° F)

6.8 5.8

4/1

6.7

IHC water tolerance 1% water

Additive separation after 21 days

Humidity chamber 48.9 C (12o ° F) evaluation after 96 hours none none none none

passed passed passed passed

SAE wear test

76 RPM 150 lbs (68 kg) passed passed passed passed

LVFA-Borg-Warner

SD 715 paper on steel coefficient of static friction at 93.3 (2oo ° F)

o, 136 o, 12o

o, 125

o, 13o

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Claims (6)

Claims 1. A salt of an amine or an irnidazoline and a phosphonic acid derivative, characterized in that the amine or the imidazoline has a long chain aliphatic group of 12 to 22 carbon atoms, and that 'Phosphonic acid, an acidic alkyl - fc- straight chain alkyl, C 2 -C ₂₂₎ * is hosphonat ^p. 2, a salt according to claim 1, characterized in, that the acid phosphonate has the formula OM ι ^e R p == 0 OH in which R is an alkyl group of 12 to 22 carbon atoms, is preferably octadecyl. 3. Salt according to claim 1 or 2, characterized in that the amine is a straight-chain alkylamine. 4. Salt according to claim 1 or 2, characterized in that that the imidazoline is derived from ethylenediamine and an aliphatic carboxylic acid, optionally with ethylene oxide. 5. Salt according to claim 4, characterized in that the carboxylic acid consists of oleic acid. 6. Use of an amine or imidazoline salt of a phosphonic acid derivative according to any one of claims 1 to 5 as an additive in lubricants. 509808/1167