AU621123B2

AU621123B2 - Additives for functional fluids

Info

Publication number: AU621123B2
Application number: AU36303/89A
Authority: AU
Inventors: Hans-Helmut Friedrich; Klaus Muller; Hermann O. Wirth
Original assignee: Ciba Geigy AG
Current assignee: Novartis AG
Priority date: 1988-06-13
Filing date: 1989-06-13
Publication date: 1992-03-05
Anticipated expiration: 2009-06-13
Also published as: EP0349483A3; JP2791495B2; BR8902776A; JPH0232052A; DE58906927D1; CA1340293C; AU3630389A; KR910001009A; EP0349483B1; EP0349483A2; ES2062090T3

Description

5010 Our Ref: 277160

AUSTRALIA

Patents Act FORM COMPLETE SPECIFIIft (ORIGINAL) 1123 Application Number: Lodged: Complete Specification Lodged: Accepted: Published: Priority: Related Art: Applicant(s): Address for Service: Ciba-Geigy AG Klybeckstrasse 141 4002 BASLE

SWITZERLAND

ARTHUR S. CAVE CO.

Patent Trade Mark Attornerys Level 10, 10 Barrack Street SYDNEY NSW 2000 the invention entitled "Additives for functional cc r c C C C C C C CC

CCCC

CI Ct C. C 'C L CtU C I IC C

SCO

l C

CC

Complete specification for fluids".

The following statement is a full description of this invention, including the best method of performing it known to me:- 1 5020 DECLARED at Basle, Switzerland on 19th May, 1989 CIBA-GEIGY AG W ner Wa degg Single Signature, by s ecial power 2.88 521 To: The Commissioner of Patents lA Additives for functional fluids The present invention relates to novel compounds containing thioether groups, to functional fluids of the series of lubricants, such as lubricating oils and greases, hydraulic fluids and metalworking fluids comprising compounds containing thioether groups, and to the use of these compounds as additives.

Various additives are generally added to functional fluids to improve their performance properties. Since, for example, lubricating oils must possess a high load-bearing capacity for the transference of more powerful forces, they are treated by the so-called extreme-pressure and antiwear additives, which treatment markedly reduces the wear phenomena which would otherwise occur. On the other hand, when oxygen and moir'.ure, for example, jointly act on a metal surface, corrosion may take place, for which reason corrosion inhibitors are added. The oxidation reactions, for example, which occur under the action of atmospheric oxygen and do so to a much greater degree at elevated temperatures, can be inhibited by the addition of antioxidants. It is known that some substances used as additives for lubricating oils can combine several such characteristics; they are referred to as multipurpose additives. Such substances are naturally much sought after on economic and practical grounds.

US-PS 4,246,127, for example, discloses disulfides and polysulfides and their use as lubricant additives. EP-A 0,166,696 furthermore discloses compounds containing thioether groups and compositions thereof with lubricants and hydraulic fluids.

*o C

C

Oqb 0

CO

C~

C. C o1 I t c fc .Ce CC CCr 4 4 c I'c* c -2- Compounds containing thioether groups have now been found which in compositions with lubricants, hydraulic fluids or metalworking fluids possess quite outstanding properties and which in combination, for example, with lubricating oils distinctly enhance the performance of th e latter compared with compounds described earlier.

The present invention relates to compounds of the formula

R'-S-CH

2

H-CH

2

-Q-CH

2

H-CH

2

-S-R

2

(I)

in which R' and R 2 are identical or different and are tert-Ci, to tert-

C

7 alkyl, C! to Ciocycloalkyl or pinane-1O-yl, and Q is

-S--CH

2 or -S-CH 2

-CH

2 In the formula I RI and R 2 are expediently ~'tert-C 4 to tert-C 7 alkyl or C 5 or Cscycloalkyl.

The compounds are expediently of the formula I, where R' and R 2 are identical. In the formula I, R' and R 2 are preferably tert-butyl or cyclohexyl.

Particularly preferred compounds are tet-uy--H-HC2SC2 -H--et-uy

(III),

0)00H *e t u yl S C 2 H -S C 2 0- H e t u I 04 4 -H -H C 2 S C 2 -H S .(VI) -S-CH2-

H-CH

2

-S-S-CH

2

H-CH

2

(II

(IX),

-3-

/-S-CH

2

H-CH

2 -S-CI1 2

-CH

2

-S-CH

2

H-CH

2

H

2 S-CH2 HC 2

-S-CH

2 Ji-CH 2

-S-CH

2

X)

CH H--C

H

3 C 013 (I) V ~CH 2 -S--CH 2 li-CH 2

-S--S-CH

2

H-CH

2

-S-CH

2 6H IH\

H

3 C CH 3

(XIII)

H3C CH 3 AH H3 and

I.,CH

2 -S-CH2 H-H--H-H--C2

H

3 C CH 3 (i) The present invention also relates to compositions which comprise a) a functional fluid of the series of lubricants, hydraulic fluids and metalworking fluids, and b) at least one compound of the formula

R

1 -S-CHz-- H-CH 2

-Q-CH

2

H-CH

2 -S-R 2 (1) in which R' and R 2 are identical or different and are tert-Ci 4 alkyl to tert-C 7 alkyl, Cs to Clocycloalkyl or pinane-1O-yl, and Q is -SS-, -S-CB2-S- or -S-CH 2

-CH

2 -4 The present invention relates especially to compositions which comprise a) a lubricating oil of the series of mineral oils, synthetic oils or mixtures thereof, and b) at least one compound of the formula I.

The compositions expediently comprise at least one compound of the formula I, in which R 1 and R 2 are tert-C4 to tert-C 7 alkyl or C 5 or C~cycloalkyl. These compositions expediently comprise at least one compound of the formula I in which R1 and R 2 are identical.

The compositions preferably comprise at least one compound of the formula I in which R1 and R 2 are both tert-butyl or cyclohexyl.

Compositions which are particularly preferred comprise at least one of the compounds of the formulae 0S 00 0

U

0 S 0

U

4 4,

S

6.

C

0 4 0400 04 00 0 4 0 4 40 4* 0 00

C

0 04 0 44444 044 00 0 4 0 0 0 4 tert.-Butyl-S-CH 2

H-CH

2

-S-CH

2

H-CH

2 -S-tert.-Butyl tet.BuylS- HliC-S-C- HCH-te.Bu tert.-Butyl-S-CH 2

-CH-CH

2 -S--S-CH2--CH2-S-tert.-Butyl tert.-ButYl-S-CB 2

-CH-CH

2

-SC-CH

2

-S-CH

2 CH2-Stert.-Butyl tet-u*-S-CH 2 -CH H-CH 2

-S-CH

2

-QH--CH

2 -Str-uy

*-S-CH

2

H-CH

2 -S-S-CH2- H-CH 2 7 CH 2

H-CH

2

-S-CH

2

-S-CH

2

H-CH

2 -S

H~H

(III)I

(IV),

(VI),

(VII),

(viii),

(IX),

Mx)I

F.-

5 CH 2 -S-CH 2 H-Cli 2 -S-CH 2 H-CH 2

-SCH

2 11 3 c\C (XI),

H

3 C ~V~CH 3

/CH

2 -S-GH 2 H-CH 2 -S-S-CH2 2 H-CH 2

-S-CH

2

H

3 C CH 3

(XII),

H

3 C V CH 3

/CH

2

-SCH

2

HCH

2 -S-CH2- C2-HC2--H

H

3 C CH 3

(XIII)

I H CH 3

(XIV).

H

3 C

H

R' and R 2 in the formula I independently of one another are a cycloalkyl rgroup having 5 to 10 carbon atoms and can be, for example, a cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl or cyclodecyl group.

Preferred is a cyclohexyl group. R1 and R 2 in the formula I independently of one another are for example pinane-10-yl having the formula 4 YH2

H

3 C V The preparation of the compounds according to the present inventioni is carried out in a manner known per se.

6 The preparation of the alkyl thiaglycidyl ethers employed as intermediate for the compounds of the formula I, is performed in the following manner: +NaOH R-SH Cl-CH 2 -C CH2 -NaCl/-Hz0 R-S-CH2-C-CH2 (II), 0 in which the substituent R is as defined above for R' or R 2 The use of a phase transfer catalyst, for example tetrabutylammonium chloride, is particularly advantageous for this reaction. The preparation of alkyl thiaglycidyl ether is also described in US-A-2,965,652, US-A-2,731,437 and BE-A-609,375.

The alkyl thiaglycidyl ethers of the formula II may then be reacted, for S example, with sodium hydrogen sulfide to form compounds of the type of S the formula III, VII or XI. The mercaptans which are formed by the addition of H 2 S to compounds of the formula II, may be converted to S compounds of the type of the formula IV, VIII or XII using, for example, dimethylsulfoxide. These mercaptans furnish with formaldehyde compounds of the type of the formula V, IX or XIII while the addition of compounds of the type of the formula II to 1,2-dimercaptoethane gives rise to Scompounds of the type of the formula VI, X or XIV.

The compounds of the formula I function already in very low amounts as Sadditives in functional fluids, such as lubricating oils, hydraulic fluids and metalworking fluids. They are preferably added to the functional fluids in an amount of 0.01 to 5 by weight, more preferably in an amount of 0.05 to 3% by weight, based on the functional fluid.

The lubricating oils in question are familiar to the person skilled in the art and are described, for example, in "Schmierstoffe und verwandte Produkte" ["Lubricants and Related Products"] by Dieter Klamann, (Verlag Chemie, Weinheim, 1982) or in "Das Schmiermittel-Taschenbuch" ["Lubricants Handbook"] by Schewe-Kobek, (Dr. Alfred Huthig-Verlag, Heidelberg, 1974). In addition to mineral oils, poly-a-olefins, ester-based lubricants, phosphates, glycols, polyglycols and polyalkylene glycols, are I particularly suitable.

.4 -7- The compounds of the formula I are readily soluble in lubricants, are accordingly particularly suitable as additives, for example, to lubricating oils and greases and enhance the extreme-pressure and antiwear properties. The oxidation-preventive and corrosion-preventive action of these compounds even toward copper should be also pointed out. Furthermore, common sealant materials are not attacked. Finally and surprisingly, the preparation of so-called masterbatches is possible.

The presence of compounds of the formula I in lubricants allows at least a partial replacement of ash-producing additives, i.e. especially zinc compounds or phosphorus-containing additives, principally zinc dithiophosphates. It is desirable to limit the amounts of zinc and its compounds and especially of phosphorus and its compounds, or avoid their use altogether, as a component of an additive for a gasoline engine motor oil in view of the possibility that the catalyst attached nowadays to the exhaust of a gasoline engine may be deactivated by the zinc and phosphorus compounds discharged in the exhaust gases.

In contrast to the possible impairment of the catalyst of a gasoline S +engine by the additives used hitherto, the compounds of the formula I C c according to the present invention allow a continued reduction in phosphorus and thereby enhance the operational reliability of the S catalyst.

L

Novel compounds and novel functional fluid compositions and especially lubricating oil compositions containing these compounds having properties further improved compared with products known hitherto, have also been C'C, found. The products are distinguished by high resistance to oxidative C t degradation and to solvolytic cleavability, and they impart, for example, to lubricating oil compositions a surprisingly high wear resistance which Sis particularly effective on the valve train, i.e. on the cams of the trtC camshafts and on the tappets of diesel engines and spark-ignition engines. Furthermore, the compounds of the formula I and the compositions comprising these compounds have a good seal compatibility and they do not corrode copper.

C C

+A

-8 The compositions according to the invention are suitable for use as lubricating cil compositions for internal combustion engines in general, they are particularly suitable for diesel engines and are very particularly suitable for spark-ignition engines. The term "spark-ignition engines" refers to internal combustion engines operating on the piston stroke principle. Internal combustion engines may be used for a variety of purposes, for example in stationary engines or as drives in means of transport such as ships, aircraft and especially in motor vehicles.

The invention can relate to compositions, for example, in which the lubricating oil is an oil for diesel engines or spark-ignition engines.

The present invention accordingly also relates to the use of compounds of the formula I as multipurpose additives for lubricants, hydraulic fluids and metalworking fluids. Compounds of the formula I are expediently employed in lubricating oils as multipurpose additives. Compounds of the formula I are preferably used as extreme-pressure and antiwear additives in lubricants and especially in lubricating oils.

S The compositions according to the invention also relate expediently to low-ash or ashless and phosphorus-free compositions which comprise a mineral oil or a synthetic oil or a mixture thereof or a hydraulic fluid or a metalworking fluid, and at least one compound of the formula The present invention accordingly also relates to the use of compounds of the formula I as phosphorus-free extreme-pressure and antiwear additives for lubricants, hydraulic fluids or metalworking fluids.

The invention refers particularly to compositions of the specified type Saccording to API classification SF, SG, CD and!or CE or according to CCMC categories G 1, G 2, G 3, D 1, D 2, D 3 and/or PDl.

C

Accordingly, the compositions expediently represent motor oils for motor vehicles, and essentially for passenger car engines and light commercial c 4 vehicle engines, which correspond to at least one of the categories SF, i SG, CD or CE of the API (American Petroleum Institute) classification and ~~4 L 9 to at least one of the categories G 1, G 2, G 3, D 1, D 2, D 3 or PD 1 of the OCMC (Committee of Common Market Automobile Constructors) classification.

The invention also comprises a method for reducing wear in diesel engines and spark-ignition engines, and in particular on the cams of the camshafts and on the tappets of the valve train, wherein the lubricating system of the internal combustion engine is run on a composition of the type described above.

The invention also comprises a method for avoiding the deactivation of the catalyst attached to the exhaust of a gasoline engine, wherein the lubricating system of the internal combustion engine is run on a composition of the type described above.

The lubricants may additionally contain other additives, added for the purpose of further improving the basic properties of the lubricants; these include: antioxidants, metal passivators, corrosion inhibitors, viscosity index improvers, pour point depressants, dispersants, S«t detergents as well as further extreme-pressure additives and antiwear t C S additives. The above reservations concerning ash-producing compounds, especially zinc compounds, and phosphorus compounds are accordingly also valid for the additional additives, a certain content of zinc-containing S phosphorus/sulfur compounds being tolerated.

Examples of phenolic antioxidants tI 1. Alkylated monophenols et 2,6-di-tert-butyl-4-methylphenol, 2,6-di-tert-butylphenol, 2-tert-butyl- 4 ,6-dimethylphenol, 2,6-di-tert-butyl-4-ethylphenol, 2,6-di-tert-butyl- 4-n-butylphenol, 2,6-di-tert-butyl-4-isobutylphenol, 2,6-dicyclopentyl- 4-methylphenol, 2-(a-methylcyclohexyl)-4,6-dimethylphenol, 2,6-dioctadecyl-4-methylphenol, 2,4,6-tricyclohexylphenol, 2,6-di-tert-butyl-4methoxymethylphenol, o-tert-butylphenol.

C C 2. Alkylated hydroquinones 2, 6-di-tert-butyl-4-methoxyphenol, 2, 5-di-tert-amylhydroqui-none, 2,6-diphenyl-4-octadecyloxyphenol.

3. Hydroxylated thiodiphenyi ethers 2,2'-thio-bis(6-tert-butyl-4-methylphenol), 2,2'-thio--bis(4--octylphenol), 4,4'-thio-bis(6-tert-butyl-3-methylphenol), 4,4'-thio-bis(6-tert-butyl- 2-me thyipheno 1).

4. Alkylidene bisphenols 2,2'-methylene-bis(6-tert-butyl-4-methylphenol), 2,2'-methylene-bis- (6-tert-butyl-4-ethylphenol), 2,2 '-methylene-bis[4-methyl-6-(ca-methylcyclohexyl)phenol), 2,2'-metbylene-bis(4-methyl-6-cyclohexylphenol), 2,2 '-methylene-bis(6-nonyl-4-methylphenol), 2,2 '-methylene-bis(4,6-ditert-butyiphenol), 2,2'.-ethylidene-bis(4,6-di-tert -butylphenol), 2,2'ethylidene-bis(6-tert-butyl-4- or -5-iso-butyiphenol), 2,2'-methylenebis[6-(ca-methylbenzy1)-4-nonylphenol), 2,2'-methylene-bis[6-(a,c-dimethylbenzyl)-4-nonylphenoll, 4,4'-methylene-bis(2,6-di-tert-butylphenol), 4, 4 '-methylene-bis(6-tert-butyl--2-methylphenol), I

C

tert-butyl-4-hydroxy--2-methylphenyl)buitane, 2 ,6-di( methyl-2-hydroxybenzyl)-4-methylpbenol, 1,1 ,3-tris(5-tert-butyl-4hydroxy-2-methylphenyl)-3-n-dodecylmec:-aptobutane, ethylene glycol bis[3,3-bis(3'-tert-butyl-4'-hydroxyphenyl)butyratel, bis(3-tert- C C butyl- 4 -hydroxy-5-methylphenyl)dicyclopentadiene, bisli2-(3'-tertbutyJ-2'-hydroxy-5'-metbylbenzyl)-6-tert-butyl-4-methylphenyllterephthalate.

Benzyl compounds l, 3 ,S-tri(3,5-di-tert-butyl--4-hydroxybenzyl)-2,4,6-trimethylbenzene, S bis(3,5-di--tert-butyl-4-hydroxybenzyl)sulfide, isooctyl butyl- 4 -hydroxybenzylmercaptoacetate, bis( 4-tert-butyl-3-hydroxy-2 .6dimethylbenzyl)dithiolterephthalate, 1,3,5-tris(3,5-di-tert-butyl-4hydroxybenzyl)isocyanurate, 1, 3,5-tris(4-tert-butyl-3-hydroxy-2 ,6-dimethylbeniwyl)isocyanurate, dioctadecyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate, calcium salt of monoethyl 3,5-di-tert-b~utyl-4hydroxybenzylpbosphonate.

6. Acylaminophenols 4-hydroxylauranilide, 4-hydroxystearanilide, 2, 4-bisoctylmercapto-6- (3,5-di-tert--butyl-4-hydroxyanilino)-s-triazine, octyl butyl-4-hydroxyphenyl)carbamate.

j 7. Esters of B-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid with monohydric or polyhydric alcohols, for example with methanol, diethylene glycol, octadecanol, triethylene glycol, 1,6-hexanediol, pentaerythritol, neopentyl glycol, trishydroxyethyl isocyanurate, thiodiethylene glycol, bishydroxyethyloxaldiamide.

8. Esters of B-(5-tert-butyl-4-bydroxy-3-methylphenyl)propionic acid with monohydric or polyhydric alcohols, for example with methanol, diethylene glycol, octadecanol, triethylene glycol, 1,6-hexanediol, pentaerythritol, neopentyl glycol, trishydroxyethyl isocyanurate, thiodiethylene glycol, dihydroxyethyloxaldiamide.

9. Amides of Q-(3,5-di--tert-butyl-4-hydroxyphenyl)propionic acid for example N,N'-bis( 3,5-di-tert-butyl-4-hydroxyphenylpropionyl)hexamethylenediamine, N,N'-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)trimethylenediamine, N,N'-bis(3, 5-di-tert-butyl--4-hydroxyphenylpropionyl)hydrazine.

V

Examples of aminic antioxidants: N,N'-di-isopropyl-p-phenylenediamine, N,N'-di-sec-butyl-p-phenylenediamine, N,IN'-bis(lV,4-dimethylpentyl)-p-phenylenediamine, N,N'-bis(1ethyl-3-methylpentyl)-p-phenylenedi,. nine, N,N'-bis(1-methylheptyl)-p- S phenylenediamine, N,N'-dicyclohexyl--p-phenylenediamine, N,N'-diphenyl- S p-phenylenediamine, N,N'-di(napbthyl--2)-p-phenylenediamine, N-isopropyl- N'-phenyl--p-phenylenedja-iine, N-(1 ,3-dimethylbutyl)-N'-phenyl-p- S phenylenediamine, N-(l-methylheptyl)-N'-phenyl-p-phenylenediamine, eamnpheno,'-nonaroyliophenolmne 4 -dodeca ylaminophenol, 4 -btyr l -12 decanoylaminophenol, di(4-methoxyphenyl)amine, 2,6-di-tert-butyl-4-dimethylaminomet'hyiphenol, 2,4 '-di-aminodiphenylmethane, 4,4'-diaminodiphenylmethane, N,N,N' ,N'-tetrarnethyl-4,4'-diaminodiphenylmethane, I ,2-dij(2-methylphenyl)aminolethane, I ,2-di(phenylamino)propane, (o-tolyl)biguanide, diJI4-(1' ,3'-dimethylbutyl)phenyllamine, tertoctylated N-phenyl-1-naphthylamine, mixture of mono- and dialkylated tert-butyl-/tert-octyldiphenylamines, 2, 3-dihydro-3, 3-dimethyl-4H-1 ,4benzothiazin phenothiiazine, N-allylphenothiazine.

Examples of other antioxidants: aliphatic or aromatic phosphites, esters of thiodipropionic acid or of thiodiacetic acid, or salts of dithiocarbamic or dithiophosphoric acid.

Examples of metal deactivators, for example for copper: Ii triazoles, benzotriazoles and their derivatives, tolutriazoles and their derivatives, 2-mercaptobenzothiazole, 2-mercaptobenzotriazole, wercaptobenzotriazole, 2,5-dimercaptobenzothiadiazole, benzotriazole, 4,5,6,7-tetrahydrobenzotriazole, salicylidenepropylenediamine, salicylaminoguanidine and their salts.

tt Examples of rust inhibitors: a) Organic acids, their esters, metal salts and anhydrides, for example: U::N-oleoylsarcosine, sorbitol monooleate, lead naphthenate, alkenylsuccinic hemiester and hemiamide, 4-nonylphenoxyacetic acid.

b) Compounds containing nitrogen, for example: I. Primary, secondary or tertiary aliphatic or cycloaliphatic amines and amine salts of organic and inorganic acids, for example oil-soluble alkylammonium carboxylates.

II.cC Heterocyclic compounds, for example: substituted imidazolines and oxazolines.

c) Compounds containing phosphorus, for example: Samine salts of phosphoric acid partial esters or phosphonic acid partial esters, zinc dialkyldithiophosphates.

13 d) Compounds containing sulfur, for example: barium dinonylnaphthalene sulfonates, calcium petroleum sulfonates.

Examples of viscosity index improvers: polyacrylates, polymethacrylates, viuylpyrrolidone/methacrylate co ;olymers, polyvinylpyrrolidones, polybutenes, olefin copolymers, styrene/ acrylate copolymer, polyethers.

Examples of pour point depre: :rs: polymethacrylate, alkylated naphthalene derivatives.

Examples of dispersants/surfactants: polybutenylsuccinamide or polybutenrylsuccinimide, polybutenylphosphonic acid derivatives, basic magnesium, calcium and barium sulfonates and phenolates.

Examples of antiwear additives: compounds containing sulfur and/or phosphorus and/or halogens, such as sulfurized vegetable oils, zinc dialkyldithiophosphates, tritolyl phosphate, chlorinated paraffins, alkyl and aryl disulfides, alkyl and aryl trisulfides, triphenylphosphorothionates, diethanolaminomethyltolyl- Striazole, di(2-ethylhexyl)aminomethyltolyltriazole.

The examples below elucidate the invention in greater detail. The parts and percentages are parts and percentages by weight, unless stated otherwise.

c Example 1: preparation of S t t C C C4H 9

-S-CH

2

-CH--CH

2

-S-CH

2

-CH-CH

2

C

4

H

9

(III)

ccc 6H H

I,

r L E iN .i 14 Reaction scheme 2tC4H9-S-CH 2 -C CH2 NaSH (30 in H 2 0) H 2 0 60 0 C t 40 2 60C C4H 9

-S-CH

2

H-CH

2 2 S NaOH H 2 0

H

73.1 g (0.5 mol) of tert-butyl glycidyl thioether are added dropwise with stirring to 50 ml (0.268 mol) of technical 30 sodium hydrogen sulfide solution, contained in a four-necked flask and diluted with 25 ml of water (duration about 1 hour). The temperature of the reaction mixture which heats up in the reaction, is kept to 40-50 0 C by cooling. Stirring is then continued at 50-60°C for 1 hour and the endpoint of the reaction is checked by the disappearance of the glycidyl thioether spot in the thin-layer chromatogram.

Working up is carried out via phase separation.

The organic phase is the reaction product. It is washed with about 20 ml of dilute sodium bicarbonate solution and is filtered, after clear phase tt c c V separation, through CELITE and is dried.

2 Yield: 77.6 g^95 of theory; yellow viscous liquid; refractive C index; n 2 0 1.5261; boiling point: 180°C/0.5 mbar C t Example 2: preparation of C t Herstellung von (tC4H-S-CH2-H-CH2-S-CH2-)2 VI c t Reaction scheme t NaOCH3 t 2 C4H-S-CH2-C-CH2 HS-CH2-CH2-SH CH 9

-S-CH

2 2

S-CH-)

2 Procedure 1 8.8 g (0.2 mol) of 1,2-dimercaptoethane and 0.5 ml of sodium Smethylate solution (30 in methanol), contained in a two-necked flask, Sare warmed to 60'C, the heating bath is removed and 61.4 g (0.42 mol) of tert-butyl glycidyl thioether are added dropwise in the course of I .2 minutes at 60-70 0 C with stirring (exothermic reaction). When the addition is completed, the mixture is further stirred for 30 minutes at about 60 0 C and volatile substances are removed in vacuo in a rotary evaporator. Working up is carried out as in Example 1.

Yield: 100 of theory; colourless liquid; refractive index: n 2 0 1.5391 Example 3: preparation of 9H (tC4H9-S-CH-CH-CH2-S-)2

IV

Reaction scheme: 2tCuH-S-CH- H-CH 2 -SH (CH 3 )zS 0

QH

-H

20 (tCH-S-CHz-H-CHz-S-) 2 -(CH3)2S

IH

36 g (0.5 mol) of the compound tert-C 4 Hg-S-CH2-CH-CH 2 -SH, 31.2 g (0.4 mol) of dimethyl sulfoxide and 150 ml of toluene are combined in a e: t reaction vessel and 1.7 ml of the water of reaction is removed with stirring by reflux. About 100 ml of toluene/dimethyl sulfoxide are then S distilled off at normal pressure, the organic k..ase is treated with 50 ml c. of toluene, washed with aqueous sodium bicarbonate solution and then with S water, dried and concentrated.

c Yield: 34.7 g^96.7 of theory, yellow liquid; refractive index n 2 0 1.5450 C t C ro, Example 4: Wear test: c c Each of the compounds III, IV and VI, prepared as in Examples 1 to 3, is mixed with an SAE 10 W-30 motor oil free from zinc dithiophosphates (the base oil being an ISO VG 32 mineral oil), designated AARG 45, at a concentration of 1 by weight, and the samples are subjected to the 1 C so-called cam and tappet (C T) test.

St ii- r 16 Brief description of the C T test: In an enclosed housing, a cam made of cast iron induction-hardened to 550-580 HV (Vickers hardness) rotates against a spri.g-loaded tappet made of casehardened steel of 800-850 HV hardness. The housing is filled with the test oil up to the middle of the cam axle. The oil is heated to 100°C by means of built-in heating rods. When the required temperature is reached, the force acting on the cam head is set to 1,000 N by adjusting the spring pressure and the test is commenced at a speed of rotation of the cam of 1,500 rpm. The wear is measured after one hour's running. If the total wear of cam head and tappet is less than 0.25 mm, the force acting on the cam head is increased by 100 N and the test is continued for a further hour at the increased cam force until either the wear is greater than 0.25 mm or a cam head force of 2,000 N is reached.

The result is reported as damage stage or, in the absence of any wear, is recorded as greater than 2,000.

Table 1 lists the measured values, a higher numerical value (in N) representing an improved antiwear performance.

:ii r *r C f C t I L C I C

ICC

C E C CC I t 44..

I LI C T

N

Base oil AARG 45 1000 1 compound of the formula III (Example 1) 1700 1 compound of the formula IV (Example 2) 1800 1 compound of the formula VI (Example 3) 1900 Example Oxidation stability test The compounds prepared in Examples 1 and 2 (additives III and VI) are subjected to the TFOU test.

U j 1 l I Y* 1 Table 1 il ~i 17 (TFOU test: Thin-Film Oxygen Uptake Test, National Bureau of Standards (NBS), Washington DC, USA) This test is a modified version of the "Rotary Bomb Oxidation Test for Mineral Oils" (RBOT) (ASTM D 2272). It is described in full in the paper by C.S. Ku and S.M. Hsu, A Thin-Film Oxygen Uptake Test for the Evaluation of Automotive Crankcase Lubricants, Lubrication Engineering, Vol. 75-83 (1984). In the TFOU test, the oil under test (1.5 contained in a glass tube placed inside a steel pressure container (bomb), in the presence of 2 of water, a liquid oxidized and nitrated fraction of a motor gasoline as catalyst (4 initial concentration) and a liquid metal naphthenate as a further catalyst (4 initial concentration) (the water and the two liquid catalysts are available from the National Bureau of Standards (NBS) under the Standard Reference Material No. 1817 with certificate of analysis), is subjected to oxygen pressure of 6.3 bar psi) (oxygen volume 65 ml). The bomb rotates in a sloping position at 100 rpm in a liquid bath at 160 0 The sloping position and the rotary movement cause the oil to be distributed as a film on the surface of the glass container.

II

1 After a given induction time, the oil begins to oxidize under these C ~r conditions. The oxidation induces oxygen uptake, manifested by a distinct Sc pressure drop. The period to the onset of oxidation, the so-called 1 induction time, is taken as a measure of oxidation stability.

r C I Ct ,c The test oil used is a motor oil based on an ISO VG 32 mineral oil, c cc comprising an additive package Oloa 4140 C (Orogil) and a viscosity index improver (an olefin copolymer). The viscosity corresponds to 15W-50 and the zinc dithiophosphate content of the additive gives rise to an 6 age analytical value of 0.067 of Zn and 0.06 of P in the oil.

I The results given in Table 2 below represent the time (in minutes) to the break in the pressure/time diagram.

Long periods correspond to effective stabilizing action. Concentration of the additives III and VI: 0.75 by weight based on the oil.

C I ~LiLi1--L-i~ 18 i I

C

I I I @4IIC 0r *D 0 4r 4 0 444e 4. 4 :3

C*

cc-.

Table 2 TFOUT min Base oil 68 0,75 by weight of the compound III from Example 1 275 0,75 by weight of the compound VI from Example 2 272 Example 6: Test for compatibility with sealant materials The test employed is the Volkswagen method VW-Seal test, P-VW 3334 at 150°C over a test period of 96 hours. The evaluated parameters are the change in the modulus 1/l (at 1/3 elongation), the change in ultimate tensile strength and the change in elongation.

The test of a test material of the type FKM (fluorine rubber) in a motor oil containing either the compound of the formula III or a compound of the formula VI brings about no significant changes in the condition of the seals in respect of elongation and changes in tensile stress compared with the motor oil without the additives of the formulae III and VI.

Example 7: Test of corrosion behaviour towards copper The Petter CEC L-02-A-78 test is used. The weight loss of copper hearings is determined after 36 hours, both in a phosphorus-free oil and in an oil containing phosphorus (P 0.06 using a compound of the formula III and a compound of the formula VI. The weight losses are less than 25 mg, thus complying with the requirements of the CCMC categories G 1, G 2 and G 3.

To illustrate the efficacy of the present invention, and do so by comparison with the acknowledged prior art (EP-A O 166,696).we now refer to the following Test Report wherein a compound of the present invention and a closely related (from the structural point of view) prior art compound are compared. The superior antiwear performance of the compound of the present invention is ,clearly evident.

I

i, r -UI 1 I 1 18a fr TEST REPORT Compounds Tested Compound A) according to EP-A 0 166 696, page 12, line 6

_H

(sec-CH 9

S-CH

2

-H-CH

2 prepared analogously to Compound B) according to the present invention (Example 1): (tert-C 4

H

9

-S-CH

2

-H-CH

2

-S

OH

t ttt

I

-f fC -f V Compositions Used From a mineral oil, "solvent neutral 150", C-content (determined by IR): Caromatic 6,5 Cparaffinic 72,0 Cnaphthenic 21,5 0,54 Sulphur, -12 -1 viscosity 26.2 *10 ms the following compositions were prepared: SOne composition consisting of the minieral oil and 1 by weight of compound and a second composition consisting of the mineral oil and 1 by tt weight of compound B).

These compositions were tested as follows: S Shell Four Ball-Test It was the object of the test to compare the antiwear performance of a compound according to the instant application on the one hand with that of the prior art compound according to EP-A 0 166 696 on the other hand.

Test Procedure With the Shell Four-ball Machine (standard test method ASTM D-2783, extreme assgressure and wear lubricant test for oils and greases, four-ball machine) the 18b weld load i.e. the minimum load under which: welding of the balls occurs (measured in was determined.

Test Conditions: 18-33 0 C, 1770 rpm, 10 seconds at different loads metal: steel on steel; report: weld load The following results were obtained: Compound Weld Load [N] SA 1400 B 1600 E'j Conclusion These results are indicative of the superior performance of compound B of this invention relative to the structurally close compound A disclosed in EP-A 0 166 696, when the antiwear-effect on steel is measured in a reproi ducible way.

With 1600 N, the value measured for the instant compound B is significantly higher than the weld load determined for the prior art compound A.

In view of the fact that the instant compound B may be considered structurally similar to compound A disclosed in EP-A 0 166 696 it was to be expected r 1 that both possess the same antiwear properties. It is surprising that this is not so and that there is a considerably higher antiwear performance to be observed using the instant compound B.

This superior performance is important because compositions having improved anti-wear properties are highly wanted in the industry because of their potential of energy savings, of reduced wear, of durability of machinery.

M

Claims

1. A compound of the formula R' -S-CH 2 H-CH 2 -Q-CH 2 H-CH 2 -S-R' in which RI and RI are identical or different and are tert--C4alkyl to tert-C 7 alkyl, C 5 to Clocycloalkyl or pinane-1O--yl, and Q is -S-CH 2 or -S-CH 2 -CH 2

2. A compound of the formula I according to claim 1, in which R, and R 2 are tert-C4 to tert-C 7 alkyl or C5 or C6cycloalkyl..

3. A compound of the formula I according to are identical.

4. A compound of the formula I according to are tert-butyl or cyclohexyl. claim 1, in which R' and R 2 claim 1, in which R 1 and R 2 A C' t CU~ t IL A compound according to claim 1 selected of the groups of fo-,mulae tCi4H 9 -S-CH 2 H-CH 2 -S-CH 2 H-CH 2 tCi 4 H9 II) C49SCH HCH--2 (IV), tert.-Butyl-S--CH 2 -C -CH 2 -S-CH 2 -S-CH 2 -C -CH 2 -S-tert.-Butyl. MV, (C4H 9 -S-CH 2 -cH-CHZ-S-CH 2 2 (VI) /-S-CH2---H-CH 2 -S-CH 2 H-Ci 2 /VI) H-CH 2 -S-S-CH 2 H--CH 2 (VIII), S-CH 2 H-CH2-S-CH2-S-CH z H-CH 2 S (Ix), dH H -S-CH 2 -HCH 2 -S-CH 2 CH 2 -SCH 2 -H1HCH2 /S 6H HH CH2-S-CH 2 -H-CH 2 -S-CH 2 -HCH 2 -CH 2 /H H H 3 C* I CH 3 (XI), V//1 H 3 C /V\CH 3 CH 2 -S-CH2- H-CH2-S-S-CH2- H-CH2-S-CH H HH H 3 C\i \CH 3 (XII), H 3 G CH 3 /CH2-S-CH2-H-CH 2 -S-CH 2 -S-CH 2 H-CH 2 -S-CH 2 H3 CH 3 (XIII) H3C\ V/ CH 3 0 r O;(./CH2-S-CH2-H-CH2-S-CH2-CH2-S-CH2- H-CH2-CH 6H HH H 3 C" 1/c i;i/H3 (XIV) H3 CH 3

6. A .,,position which comprises a) a functional fluid selected of the groups of lubricants, hydraulic fluids and metalworking fluids, and b) at least one compound of the formula I. S t,

7. A composition according to claim 6 which comprises a) a lubricating oil selected of the groups of mineral oils, synthetic oils or mixtures thereof, and b) at least one compound of the formula I. I1l*//C 3 (i -21

8. A composition according to claim 6 which comprises at least one compound of the formula I in which R1 and R 2 are tert-C. to tert-Cialkyl or Cs or C 6 cycloalkyl. A composition according to claim 6 which comprises at least one compound of the formula I in which RI and R 2 are identical. A composition according to claim 9 which comprises at least one compound of the formula I in which R 1 and R 2 are tert-butyl or cyclo- hexyl.

11. A composition according to claim 9 which comprises at least one compound selected of the groups of formulae fH H 11 t tert.-Butyl-S-CH 2 H-CH 2 -S--S-CH 2 CH 2 -S-tert.-Butyl (IV), C C tet-Butyl-S-CH2- H-CH 2 -S-CH 2 -CH 2 -S-CH H-GH 2 -S-tert.-Butyl (VI), *H H H H S.-CH 2 H-CH 2 -S-S-H 2 (VII), H H£ *-S-CH 2 -CH-GH 2 -S-CH 2 -S-CH 2 -CH-CH 2 (IX), H cH 6 C- -H -H C 2 S C 2 C 2 S C 2 -H C C -22- ,CH2--S-CH 2 -CH-CH 2 -S-CH 2 -CH-CH 2 -S-CH 2 H 3 C\ CH3 (XI), H3C CH3 CH2-S-CH2- H-CH2-S-S-CH2-CH-CH2-S-CH2. S* 6H H H 3 C CH (XII), I /V H3C CH3 CH2-S-CH2-H-CH2-S-CH2-S-C-H2-CH-CH 2-S-CH2 bH H H3C\\ I i/CH 3 X I I I H3C CH3 or CH2-S-CH2-H-CH-S-CH-CH2-S--CH2-S-CH22-H-CH2 -C2 C OH 6H C H3C i\ H3 (XIV). CtV \C C H3C CH3 SC ct Sc 12. A composition according to claim 7, in which the lubricating oil is J C an oil for diesel or spark-ignition engines. t c 13. A composition according to claim 7 which conforms to API classifi- cation SF, SG, CD and/or CE or to CCMC categories G 1, G 2, G 3, D 1, D 2, D 3 and/or PD 1.

14. A process for reducing wear in diesel and spark-ignition engines, especially on the cams of the camshafts and on the tappets of the valve train, in which the lubrication system of the internal combustion engine >c is run on a lubricating oil having a composition according to claim 7. C CT C C CI c 15. A process for preventing the deactivation of the catalyst attached to the exhaust of a gasoline engine, in which the lubrication system of the internal combustion engine is run on a lubricating oil having a composi- tion according to claim 7. m a 23

16. A process of making lubricants having improved multipurpose properties, comprising the step of adding to said lubricant a compound of the formula I according to claim 1. ii r C i" I tZt: 4 Ii

17. A process of making lubricants, hydraulic fluids or metalworking fluids having improved extreme-pressure and antiwear properties, comprising the step of adding to said lubricant a compound of the formula I according to claim 1.

18. A compound of formula as described herein, substantially as herein described with reference to anyone of the Examples. DATED this 25th day of November, 1991. Ciba Geigy A.G. By Its Patent Attorneys DAVIES COLLISON CAVE i