US3105818A - Lubricating compositions - Google Patents

Description

. 3,105,818 Patented Oct. 1,19 3

3,105,818 LUBRICATING COMPOSITIONS William A. Hewett, Oakland, Calif., assignor to Shell Oil.

Company, a corporation of Delaware No Drawing. Filed June 2, 1959, Ser. No. 817,462 4 Claims. (Cl. 252-475) This invention relates to lubricants and particularly to highly detergent lubricants useful under severe operating conditions, such as under extreme high speed and at high temperatures, and to a new and novel class of polymeric additives therefor.

It is well known that the high pressure occurring in certain types of gears and bearings may cause rupture of lubricant films with consequent damage to the machinery. It is known that various base lubricants can be improved in their protective properties of rubbing surfaces by the addition of certain substances, so-called extreme pressure agents, so that excessive wear, scufling and seizure are minimized or prevented. a

It is known that certain compounds of metal-reactive elements, such as certain compounds of chlorine, sulfur and phosphorus, as well as certain other compounds, such as some compounds of lead, impart extreme pressure properties to various lubricants. Notable among the substances heretofore used are the lead soaps, phosphoric acid esters, free or bound sulfur and certain chlorinated organic compounds. A principal objection to many of these extreme pressure agents is their lack of detergency and their high reactivity with the metallic surface, causing etching, corrosion and discoloration of the metal'surface. Another objection to chemically reactive extreme pressure agents is that they alter the original chemical nature of the contacting surface, which under certain conditions is undesirable. Additionally, because of the activity of agents of this type, they usually are depleted rapidly resulting in only a temporary solution to the problem of extreme pressure lubrication.

It has now been discovered that improved detergent and extreme pressure lubricants are provided by a suit-.

able lubricating oil containing oil-soluble high molecular weight non-ash halo-mercapto-containing polymeric compounds having essentially a long linear hydrocarbon backbone chain and attached thereto in a uniform or random fashion two kinds of essential groups, one an oil-solubilizing hydrocarbyl radical, preferably an alkyl radical having an average of bet-ween 8 and 20 carbon atoms (preferably 10-16) bonded directly to the hydrocarbon backbone chain or indirectly thereto through a polar group and the other an alkyl radical containing a halogen and an aryl mercapto group on adjacent carbons of the alkyl radical, which groups are at least two carbon atoms removed from the main hydrocarbon polymer chain alkyl carbons. This polar substituted radical is represented by the formula Halo S-Q where Q is an 'aryl radical, X is a polar radical such as halogen, amino, nitro, sulfo or the like, x and y are integers of at least 1, preferably 4-20, and z is a number from zero to 2. The number of units (I) in the final polymer can vary from 10 to 1000 or more, preferably from to 800, inclusive. Polymers of this invention contain a plurality of units represented by HO x ANV where x, y, z, Q and X are as defined, m is a whole number, and Y is an oil-solnbilizing radical containing a C alkyl radical attached directly or indirectly to the main backbone chain through a polar group such as where Z is hydrogen or an alkyl radical. The molecular weight of the polymer varies from about a thousand to about amillion, preferably from 10,000 to 500,000.

The oil-soluble halo-mercapto aryl containing polymers of the above type are prepared by reacting aryl sulfenyl halides with an cil-soluble'uns'aturated linear hydrocarbon polymer which, in turn, is prepared by polymerizing a polyene hydrocarbon with a monoolefinically polymerizable monomer having a 1ong-chain alkyl radical such as long-chain alpha-olefins, long chain alkyl esters of alpha,beta-unsaturated acids, such as esters of acrylic and m'ethacrylic acids, esters of lower unsaturated alcohols, such as vinyl and allyl alcohol estersof long chain fatty acids and long chain N-alkyl unsaturated fatty acid amides such as N-alkyl acrylamides.

The sulfenyl halides useful in the preparation of the novel polymers of this invention include aryl sulfenyl halides, such as benzene sulfeny-l chloride, bromide, iodide or fluoride, e.-g., benzene sul-fenyl chloride, p-toluene sulfenyl chloride, butyl benzene sulfenyl chloride, etc.; halogen-substituted benzene sul-feny-l halides, e.g., chloroben zene sulfenyl chloride, 2,3-, 3,4- or 2,4-dibromobenzene 'sulfenyl chloride, 2,4,6-trichlorobenzenesulfenyl chloride, 'pentachlorobenzene sul-fenyl chloride, 2-chloro-3-bromobenzenesulfenyl chloride, p-fluorobenzenesulfenyl chloride, etc; and nine-substituted benzenesulfenylhalides such as p-nitrobenzene sulfenyl chloride or 2,4-dinitrobenzenesulfenyl'chloride or bromide, etc. Theremay also be used benzene sulfenyl halides such as 4-chloro-2- 'nitrobenzene sulfeny-l chloride, '2-chloro-4-nitrobenzenesulfenyl chloride, or Z-chloro-S-methylbenzenesulfenyl chloride, i.e., benzenesulfenyl halides having a diversity of substituents in the benzene ring. Especially preferred in the present process are the chloroand/or nitro-substituted benzene sulfenyl halides. V

' Suitable polyene hydrocarbons for forming the copolymers are C dienes, for example, 1,3- and 1,4-pentadiene, isoprene, 1,3-hex-adiene, 1,3,5-heptatriene, 1,3-cyclopentadiene, methylcyclopentadiene, 1,3- and 1,4,-c'yclohexadiene, methylcyclohexadiene, and mixtures thereof.

Other d-ienes are obtained by dehydration ofunsaturated I tridecyl ether, vinyl tetracosyl prene, Compound A I: A V 3 fatty alcohols such as lauroleyl, myristoleyl, palmitoleyl, gadoleyl, linoleyl, iicinoleyl alcohols. A diene of this type which is particularly suitable is obtained by dehydrating oleyl alcohol which results in a 50-50 mixture of monoenes and dienes of C to C carbon atoms having the following properties:

Iodine value 183. Hydroxyl value 0.4. Boiling range Over 100 C. at 1 Hg. Appearance Colorless-pale yellow liquid. Melting range 55 to 70 C. (approx). Flash point (Cleveland open 152 C.

P) Viscosity 2.47 centistokes at 100 F.,

1.29 centistokes at 210 F. Specific gravity, 25/25 C 0.7965.

This material will be identified as Compound A.

Representative oil-solubilizing monomer compounds which are used to form the copolymers with the polyene (C H A1 -TiCl at room temperature for about 24 hours. The catalyst was destroyed by addition of methanol and polymer thereafter purified by benzene washing and pre cipitating from alcohol and vacuum drying. The',polymer had an average molecular weight of 300,000 and an average of 750 double bonds per polymer molecule as shown by bromine number.

Example Tl About 0.5 mole of Compound A, 0.17 mole of l-tetradecene and 0.34 mole of l-dodecene in benzene were reacted in the presence of the Ziegler catalyst and under the conditions of Example I. .The polymer formed had a molecular weight between'350,000-400,000 and abrohydrocarbons include alpha-unsaturated long chain hydrocarbons, unsaturated esters, unsaturated amides, e.g., such as decene-l, dodecene-l, tridecene-l, tetradecene-l, hexadecene-l, lreptadecene-l, octadecene-l, tritriacontene-l, tetratriacontene-l, heptacontene-l, 4-rnethyl-decene-1, 4,

4-dimethyl-decene-l, 5,5-dimethylhexene-l, 5,5,7,7-tetramethyl-decene-l, 4,4,6,6-tetrametl1ylheptene-1, etc., vinyl decanoate, vinyl laurate, vinyl tridecanoate, vinyl myristate, vinyl pentadecanoate, vinyl palmitate, vinyl marga- Iate, vinyl stearate, vinyl nonadecanoate, vinyl arachidate, vinyl behenate, vinyl 4,5,6-trimethyldodecanoate, vinyl 6,8,9-triethyl tridecanoate, vinyl l2-hydroxystearate, vinyl 9,l0-dihydroxystear-ate, vinyl chlorostearate, vinyl cyanostearate, vinyl acetylstearate,

from US to 5/1, respectively. The polymer (prior to. treatment with an aryl sulfenyl halide compound) should have a substantial amount of unsaturation.

Depending on the monomers used the polymers can y be prepared thermally or in the presence of a suitable catalyst. 'Thus, with monomerssuch as butadiene, isoand long chain alpha-olefins such as alpha-dodecene or alpha-octadecene, the so-called Ziegler catalysts are preferred, such as combinations of aluminum trialkyls and a variable valence metal compound, e.g., titanium tetrachloride. In the formation of other types of oil-soluble polymers such as copolymers of the polyene (e.g., butadiene, isoprene, or Compound A) with lauryl rrnethacrylate or with vinyl stearate or with N- lauryl methacrylamide, oxygen-yielding catalysts are preterred such as, for example, various organic peroxides, including aliphatic, aromatic, heterocyclic and acyl peroxides, such as *diethyl peroxide, tertiary butyl hydroperoxide, dibenzoyl peroxide, dimethyl-thienyl peroxide, dicyclohexyl peroxide, dilau-royl peroxide and urea peroxide. These are mentioned by way of non-limiting. examples of suitable organic peroxides. Other catalysts include sodium bisulfite, diethyl sultoxide, ammonium persulfate, alkali metal perborates, azo alpha-alpha-azodiisobutyronitrile, etc.

The following Examples I-X are given as representative preparations of the inter-mediate copolymers for reaction with sulfenyl halide compoundsto form the desired end product. T i I Examplel V About 0.66 mole of 1-octadecene,.l.33 moles of 1- dodecene and 0.5 mole of Compound 'A in cyclohexane were reacted in the presence of a Ziegler catalyst compounds, such as nitrogen atmosphere withstirring. To the mixture was mine number of 50.

Example III About 2 moles of acrylate and 1% C. for about 24-hours. The polymer was purified by alcohol washing, filtered and dried. The resulting copolymer had a molecular Weight of 3000-5000 and substantial unsaturation as shown by a bromine number of 80 to 100.

Following essentially the procedures of Examples 1411,

other polymers were prepared in accordance with the following tabulation:

Example Catalyst Temperature, PoIyene/oil-soluble mono- C. olefius ratio Ziegler Oat.--

Benzoyl peroxide. do

isoprene(2)loctadecenel ry VII butadlene {2){014-15 diene of dehydrator Orr-r4 unsatvinyl stearate (l pentadlene (3)/N-laurylmethacrylarnide (1).

VIII

Ditert-butyl peroxide. r. do

(3)]lauryl methacrylato nllyl stearate (1) The final oil-soluble polymeric additive is prepared by reacting the unsaturated copolyrner, such as those of Ex amples I-X, with one or more of the sulfenyl halide compounds by any suitable means, such as described in J our. Am. Chem. Soc., 75, 6030 Specifically, in carrying out the final reaction the sulfenyl halide is simply contacted with the unsaturated polymer at ordinary, increased or decreased temperatures, until formation of the halo-sulfur containing product has occurred. Depending upon the individual reactants cut-- ployed, as well as on the quantities used, heating-or cool ing of the reactant mixture may be required. In many cases, formation of the products takes place spontaneously, although the reaction may, if desired, be expedited by heating the reaction temperature and in dissipating the heat of reaction. Useful inert solvents and diluents are, e.g., benzene, toluene, hexane, ether, etc. An excess of either reactant and gradual introduction of by pressure variation or acceleration thereof by catalytic I means.

The invention is further illustrated, but not limited, by the following examplesf Example A In a suitable vessel 40 grams of the copolymer of Example II was dissolved in 200 ml. of benzene under a pentadiene and 1 mole of lauryl rrieth- V diter-tbutyl peroxide were reactedyat 75-' bu(liadiene(2)/octadecene-l isoprene(3)/lauryl methac- Diana 01 ricinoleyl alcohol (i) stearylmethacrylate' the other may i also result in smoother operation. The present reaction.

added 30 grams of 2,4-dinitr'obenzene sulfenyl chloride and the mixture was stirred at room temperature for about 72 hours. The chlorine-sulfur-containing polymer was then precipitated from solution with methanol and then dissolved in benzene, filtered, precipitated with methanol and the procedure repeated. The polymer was then vacuum oven dried at 0.1 mm., 120 C. to give a polymer product having a plurality of beta-chloroalkyl 2,4-dinitrophenyl sulfide units having the following analysis:

Percent wt. carb n 74.9 Percent wt. hydrogen 11.6 Percent wt. nitro en 2.35 Percent wt. chlorine 3.01 Percent wt. sulfur 2.71

Example B The procedure of Example A was followed using the polymer of Example 11 and benzene sulfenyl chloride as the sulfenyl halide compound. The final polymer molecule contained over 500 units of groups distributed in the molecule Example C The procedure of Example A was followed using the polymer of Example I and 2,4-dinitrobenzene sul fenyl chloride. The final product contained over 500 units of groups distributed in the molecule.

Following essentially the above procedures other polymers containing a plurality of halogen-sulfur-containing groups in the molecule were prepared in accordance with the following tabulation.

are used in amounts of from about 0.5% to about 20%, preferably from about 1% to about 5% by weight. However, under certain storage and use conditions, it is desirable to incorporate into oil compositions containing these polymers a small amount (01-10%) of an oilsoluble branched-chain aliphatic monohydric alcohol. These alcohols can effectively stabilize such compositions without destroying the extreme pressure properties of such oil compositions.

The lubricating oil base is suitably selected from various synthetic oils or natural hydrocarbon oils having a viscosity range of from SUS at 100 F. to 250 SUS at 210 F. (SAE viscosity number ranging from SAE 5W to SAE 90). The natural hydrocarbon oilsare obtainable from parafiinic, naphthenic, asphalti-c or mixed base crudes, and/ or mixtures thereof. Useful synthetic oils include polymerized olefins, alkylated aromatics, isomerized waxes, copolymers of alkylene glycols and alkylene oxide (Ucon fluid, US. 2,425,755, 2,425,845 and 2,774,- 733) organic polyesters such as esters of an aliphatic dibasic acid and a monohydric alcohol, such as di-Z-ethyl hexyl sebacate or di-2-ethylhexy1 adipate esters of polyhydric alcohols and monocarboxylic acids, such as pentaerythritol tetracaproate, and the like. Useful Ucon fluids are Ucon 50HB170, Ucon 50HB6'60 or Ucon LB550X, which are copolymers of ethylene and 1,2-propylene oxides; the diols as well as their monoand dialkyl ethers are useful. The hydrocarbon oils may be blended with fixed oils such as castor oil, lard oil and the like and/ or synthetic oils as mentioned or silicone polymers and the like. Typical oils of this type are petroleum motor oils (A) and (B), characterized below, (A) being parafiinic in character and (B) naphthenic in character:

Properties (A) (B) (SAE 10W) (SAE 30) Pour point, F 10 5 Flash, F 390 415 Viscosity, SUS at 210 44 58 Viscosity Index..- 90 60 The halo-sulfur-containing polymers are oil-soluble and Other suitable oils are specification gas turbine lube oils having the following properties:

Grade 1010 1065 Flash, 000, F ,300 465 Pour, F 10 0 Viscosity, SUS at 100 F 59. 4 530 Neutral Number 0.02 0. 01

A h None None The following compositions are illustrative of the invention, the percentages being by weight.

Composition A: Percent Example A additive 2 1010 mineral oil Balance Composition B:

Example B additive 2 1010 mineral oil Balance Composition C:

Example C additive 2 1010 mineral oil Balance Composition D:

Example A' additive 5 Mineral oil (SAE Balance Composition E:

Example D additive 1 1010 mineral oil Balance Composition G:

Example E additive 3 SAE 90 mineral oil Balance Composition H:

Example F additive 2 SAE 90 mineral oil Balance 7 Composition 1:

Example A additive 5 Ucon 50H-B660 (polyethylene propylene glycol having a SUS viscosity at 100 F.

Compositions of this invention and other compositions were evaluated for their ability to impart to mineral oil (1) detergency as determined by the Carbon Black Dispersency Test described in the Journal of Colloid Science, vol. 12, October 1957, No. 5, pages 500-522; at 100 C. and 5 r.p.m.; and (2) extreme pressure properties as determined in the spur gear machine. The results are shown in Table I.

The spur gear machine consists essentially of two geometrically similar pairs of gears connected by two parallel shafts. The gear pairs are placed in separate gear boxes, which also contain the supporting ball bearings. One of the shafts consists of two sections connected by a coupling. Loading isaccomplished by locking one side of the coupling and applying torque to the other. The conditions of the test were:

The polymers of this invention are useful also for providing superior load-carrying properties in lubricating oils which contain minor amounts of other agents which are non-reactive with the polymer, such as silicone anti-foaming agents, alkylphenol anti-oxidants, polyacrylate ester viscosity-index improvers, and the like.

I claim as my invention:

-1. A lubricating oil composition comprising a major amount of mineral oil and from about 0.5% to 20% of an oil-soluble linear hydrocarbon polymer containing units of C alkyl groups and C-C(CH2CH j, a Halo S-Q-X, groups attached to different carbons of the linear hydrocarbon chain where Q is benzene, X is a polar group selected from the group consisting of halogen, amino, nitro i and sulfo groups, the number of halo and SQ-X units in the polymer varying from 10 to 1000, and x and y are integers of at least 1, and z is a number from 0 to 2, the molecular weight of the polymer ranging from 10,000 to 500,000. a i a 2. A mineral lubricating oil composition comprising a.

major amount of mineral lubricating oil and from about 1% to about 5%, of an oil-soluble linear hydrocarbon polymer containing C alkyl groups and Cl,

groups on different carbon atoms of the linear hydrocarbon chain with the latter two groups, the number of such groups in the polymer ranging from to 800 units and being attached to adjacent carbon atoms of an alkyl side chain and X is selected from the group consisting of chlorine and nitro group, the molecular weight of the polymer being from 10,000 to 500,000.

3. A mineral lubricating oil composition comprising a major amount of mineral lubricating oil and from about 1% to about 5%, of an oil-soluble linear hydrocarbon polymer containing on ditlerent carbon atoms of the linear hydrocarbon chain C alkyl groups and alkyl group containing on adjacent carbon atoms chlorine and the number of such units ranging from r100 to 800 and the j molecular weight of the polymer being fromabout 10,000 i to about 500,000.

References Cited in the file of this patent UNITED STATES PA'lEblTS 2,236,168 Dietrich Mar. 25, 1941 2,317,751 Frolich et al. Apr. 27, 1943 2,479,450 Young et al Aug.'16, 1949 2,719,827 Lowe Oct. 4, 1955 2,744,099 Mitchell et al. May 1, 1956 2,781,318 Cyphers Feb. 12, 1957 2,800,450 Bondi et al. July 23,v 1957

Claims (1)

1. A LUBRICATING OIL COMPOSITION COMPRISING A MAJOR AMOUNT OF MINERAL OIL AND FROM ABOUT 0.5% TO 20% OF AN OIL-SOLUBLE LINEAR HYDROCARBON POLYMER CONTAINING UNITS OF C8-20ALKYL GROUPS AND