US2225367A - Lubricant - Google Patents

Description

Patented Dec. 17, 1940 UNITED STATES PATENT OFFICE ,or to Union Oil Company of Calif Angeles, Calif., a corporation of California ornia, Los

No Drawing. Original application January 18,

1937, Serial No. 121,167.

Divided and this application April 29, 1940, Serial No. 332,288

20 Claims.

This invention relates primarily to modified mineral lubricating oils,,,the general object of the invention being to supply to lubricating oils 5 oiliness and stabilizing constituents, capable of imparting extreme pressure characteristics and also of overcoming the deposition of gums, resins and varnish-like materials uponand about the valves and rings of internal combustion engines,

10 and preventing the sticking of rings and valves especially in engines of the Diesel ,type where operating conditions are in general rather severe. This is a division of my copending application Serial No. 121,167 filed January 18, 1937.

In the case of many lubricating oils there has in the past been a strong tendency-toward the development of resinous and similar deposits about valves and rings of internal combustion engines due principally .to the lubricating oil used, although in part to the fuel in some instances. These objectionable deposits, which often result in such sticking of valves and rings as to interfere materially with engine operation, are perhaps more often found in the case of 25 Diesel engines and engines operating under' similar severe conditions.

I have found that the tendency of mineral lubricating oils to deposit gums, resins and varnish-like materials can be largely overcome by the addition of comparatively small quantities 80 I of certain types of oil-soluble-metal soaps, particularly soaps of halogenated fatty acids, halogenated naphthenic acids, and halogenated synthetic petroleum acids such as those produced by 35 oxidation of petroleum fractions to yield oil-soluble synthetic acids of fairly high molecular weight. Such oil-soluble soaps preferably are those of the alkali earth metals and heavy metals in general, for example calcium, magnesium, alu- 40 minum, lead, ironand zinc soaps. Other possibilities for soaps of such acids are found in sodium, potassium, copper, cobalt and nickel soaps 1 when oil-soluble.

Broadly stated, the inven ion resides in a lubricating oil otherwise possessing the properties of 5 forming gummy, resinous and varnish-like deposits upon and about valves and piston rings of internal combustion engines, containing a small quantity, but sufiicient however to avoid substantial'deposit of such objectionable mate- 50 rials, of a metal soap of acids of the type of halogenated fatty acids and halogenated synthetic petroleum acids of relatively high molecular weight, 1. e., having not less than about ten carbon atoms. For these purposes the soaps are 55 to be employed ordinarily to the extent of about 1%, for the reason that substantially greater amounts of soaps tend ordinarily to thicken the oils undesirably and without benefit, whereas small quantities, for example about /g% or less, ordinarily do not impart sumcient stabilizing alcohols such as ethyl and amyl alcohol and from capacity .to avoid or overcome deposition of gums. resins and the like. These oils also possess improved film strength or load-carrying capacity. The invention resides furtherin oil containing 5 such soaps as above indicated for the indicated purpose wherein the oil itself is especially adapt-' ed to the severe uses encountered in Diesel engin'e's andthe like. Such an oil preferably is a naialithenic base oil which in itself afiords some 10 solvent characteristics for gums, resins, and varnishes. On the other hand, highly refined, highly parafflnic oils may be employed at least for some uses, as may less heavily refined highly paraffinic oil, such as ordinary grades of Pennsylvania oils.

I have also discovered that oil-soluble metal or organic base soaps of non-halogenated acids of the types above described may be combined as one component of a double-component addi- 0 tion material with any type of oiliness agent as a second component. Such a second constltuent may be methyl ma. dichloro-stearate, other oiliness agents of the type produced from other other acids such as oleic, palmitlc and similar acids, chlorinated paraflin, sulfurized lard oil,

chlorinated diphenyl oxide, sulfurized or halogenated fatty acids of the types herein indicated, halogenated or sulfurized synthetic petroleum acids such as have been described, tricresyl phosphate, and in general all other types of oiliness agents. I

Therefore the invention may be also stated as extending to the use in mineral lubricating oils of an oil-soluble soap constituent combined with an oiliness or film-strength-improving element or constituent, such as one or more sulfur or chlorine atoms or phosphorus groups and the like, contained either in the soap itself, or contained in a second additive component when the soap itself does not contain such an oiliness or film-improving element or constituent. In this respect, the invention also includes soaps made with organic bases such as triethanolamine, quinoline, nitrogen bases from petroleum and the like. Such organic base soaps are to be used as substitutes for said oil-soluble metal soap when that soap is not chlorinated (or similarly modified) and is required to be used in a two-component additive material. When such an organic base soap is chlorinated it may be used as a single component additive as a substitute for the oil-soluble metal chlorinated soaps (or similar soaps) described. Soaps appropriate for this purpose are represented by triethanolamine naphthenate, triethanolamine chloro-naphthenate, trieth-anolamine chlorinated or sulfurized fatty acid soaps and other similar soaps of acids herein mentioned. I

In practicing the present invention, any otherwise satisfactory mineral lubricating oil is selected. As above indicated, this is preferably a naphthenic bas or Western type oil, especially where such an oil is to be used for Diesel engine lubrication. On the other hand, where con- 'ditions are less severe, parafllnic oils may be employed.

According to one form of the invention, I add to such an oil approximately 1% of a soap capable of preventing the formation and/or accumulation of gums, resins and varnishes upon and about rings and valves of internal combustion en. gines. While the amount of such soaps may be varied between about 0.5% or 0.6% and about 2%, I prefer to us approximately 1% or between about 0.8% and 1.25%, inasmuch as such proportions have so far proved to be most beneficial.

The soaps which I have found to be highly satisfactory for these purposes are especially the alkali earth metal soaps of halogenated fatty acids and of halogenated high molecular weight synthetic petroleum acids. For example the calcium soap of chlorinated stearic acid has been found highly efficient. Similarly, the calcium soap of chlorinated oleic acid is very desirable. Both the calcium dichlorostearate and the calcium dichloro-oleate function adquately in the proportions above indicated to yield a highly satisfactory oil for Diesel engine or similar uses, the performance of the two oils being much the same, although the two chlorine atoms are attached to the 9th and 10th carbon by direct addition in the case of the chlorinated oleic acid, whereas they are attached to the alpha carbon by substitution in the case of the saturated stearic acid. The chlorine content of these two materials is about 20% based on the acid, although it may be in the case of the chlorinated stearic acid that part of the chlorine is attached to the beta carbon or the gamma carbon or elsewhere. Such chlorine contents lower the melting points of the acids and render both the acids and their indicated soaps readily compatible with the lubrieatin oil, yielding the freely oil-soluble soaps indicated. In addition to the calcium soaps, other alkali earth metal soaps such as magnesium soaps may be employed, as may other metal soaps like aluminum dichloro-oleate and stearate.

Again, soaps of other chlorinated fatty acids having aminimum of about ten carbons to insure a sufiiciently high molecular weight and boiling point may be employed. Corresponding soaps of chlorinated synthetic petroleum acids likewise may be employed. These acids themselves are well known on the market, and are frequently produced by oxidation. catalytically and otherwise, of petroleum products, particularly fractions in the light and intermediate lubricating oil ranges, oxidation being a convenient means for the formation of the acids. These acids are recovered by precipitation as soaps with subsequent cracking out by the use of strong mineral acids to yield the purified acids. These procedures are generally well understood and need not be here described. These acids may be more or less readily chlorinated or otherwise halogenated merely by passage of the halogen gas through the acids to effect the desired substitution and/or addition, followed by adequate neutralization and washing. The soaps of such halogenated acids are then readily formed by saponification with suitable metal salts, hydroxides or oxides in the sam way that fatty acid soaps are formed, as

} well understood in the industry.

In addition to the indicated metal soaps of various halogenated fatty acids such as oleic, linoleic, stearic, palrnitic, the coconut fatty acids and the-like, and the indicated soaps of halogenated naphthenic acids and halogenated synthetic petroleum acid, I may also use corresponding oil-soluble sulfurized or phosphorus-bearing soaps of such acids of sufliciently high molecular weight as herein indicated. Also, I contemplate the us of special soaps, such as a lead soap of highly chlorinated organic acids, particularly naphthenic acids, as components in extreme pressure gear oils and the like. Thus, the oil soluble metal soaps of the chlorinated or otherwise halogenated naphthenic acids, corresponding sulfurized acids, and halogenated and sulfurized lard oils and fatty acids, and the like are included.

According to another form of the invention, I have found it practicable to use a two-component additive material, one of which is a nonhalogenated or sulfurized soap for the purpose of prevention of deposition of gums and resins and the like, and the other of which is an oiliness constituent which imparts high load carrying capacity. Whereas, in the case of a single component, calcium dichloro-stearate for example, both of the oiliness element and the element for overcoming deposition of gums and resins are contained in one compound, in this modification of the invention the soap which largely overcomes deposition of gums and resins does not contain combined therein an agent for improving oiliness and film strength, such as sulfur, a halogen, phosphorus, or the like, but the soap is employed in conjunction with a second component of which methyl dichloro-stearate is a good example, such second agent imparting the desired oiliness and increased load carrying capacity. For example, I may employ approximately 1% of a calcium soap of palm oil, or. coconut oil, or oleic acid, stearic acid or the like, or other disclosed acid, together with about 0.5% to 1.0% of methyl dichloro-stearate as the oiliness agent to increase film strength and load carrying capacity. Other oiliness agents of this general typ may be substituted such as those produced from ethyl, amyl or other alcohols and from oleic, palmitic and other acids, the agent containing one of the halogens such as chlorine, bromine. fluorine or iodine. In addition to halogenated ester types, other types of oiliness agents, such as chlorinated paraflin, sulfurized lard oil, sulfurized fatty acids, sulfurized acids of the other types herein disclosed, chlorinated diphenyl oxide, tricresyl phosphate and kindred phosphorous compounds, and the like may be employed. In this manner the oiliness element such as chlorine, sulfur, phosphorus, or the like, is obtained through the medium of an agent other than the soap.

Similarly, I may use organic bases in preparing soaps for the use of the present invention. Such bases are represented by triethanolamine, quinoline bases, nitrogen bases from petroleum and the like. Where the triethanolamine soap is to be used as one of the components of a twocomponent additive material, the acids would not generally contain an oiliness element such as chlorine, sulfur or the like. Such acids may be naphthenic acids, fatty acids containing a minimum of about 10 carbon atoms, synthetic petroleum acids as from oxidation of paraflin waxes and refined petroleum oils and all other types of acids herein mentioned. When the organic base soap, such as a triethanolamine soap, is to be used as a single component additive, then the acid radical will contain the oiliness agent-such as chlorine, sulfur, phosphorus, a phenyl group or other suitable substituent'. Soaps of this character will be used in percentages similar to those employed with othersoap's.

In all aspects of the present invention, it will of course be obvious that in the case of chlorinated or sulfurized or similar materials that either the acids employed may first be chlorinated or otherwise treated, or the soaps after their formation may be so chlorinated, sulfurized, or otherwise modified, and the materials produced I by both methods are intended to be included from naphthenic acids .and present a. vastly when acids and soaps are mentioned herein.

With respect to the synthetic petroleum acids,

paraifin acids and the like such as produced by oxidation as herein mentioned, as distinguished from naphthenic acids, attention is called to the j fact that these acids are of differentcharacter greater degreeof ,oiliness properties than do the naphthenic acids and are inmost instances to be preferred to naphthenic acids or any other naturally occurring petroleum acid such as obtained from petroleum distillates. The synthetic petroleum and paraiiin .acids mentioned may be produced by oxidationas well understood in the art-or otherwise. V

Soaps of the indicated nature when added to lubricating oils-are stable in use. and when emis that quantity necessary to effectively avoid subployed in the'indicatedproportions donot appreciably afiect the fluidity of the oils for lubrication purposes. The amount of soap tobe added to the oil, as is evident from the above disclosure,

stantial deposit of gummy, resinous and varnishlike materials whereby to overcome ring and valve sticking in internal combustion engines including engines of the Diesel type. At the same time 4o tendencies in fuel used with the engines to de- 50, or amounts extending up to possibly as high as 5% posit similar or other gummy, resinous, var-' nish-like constituents which tend to cause ring f and valve sticking, are likewise overcome by the use of such amount of the indicated type of soap.

As has been indicated, thisiamount is ordinarily in the order of about 1%. Besides an ordinary range between about 0.5% and 2% as previously indicated, there may be instances where as little as 0.1% may be used, and on theother hand largmay be desirable under some conditions, for example'where high temperatures are encountered. In other words, varying conditions can require wider ranges.

,While the'invention has been indicated as particularly applicable to mineral lubricating .oils, .it may also be extended to fatty lubricating oils I and the like.

It is to be understood that the above disclosures are furnished'as being illustrative of the present invention, and that they are not to be taken as limiting beyond the requirements 01 the prior art and as indicated by the appended claims.

I claim: i V

1. A freely liquid-lubricating oil containing a small quantity of an oil-soluble soap of a synthetic petroleum acid in quantity between about /2% and about 2% and suificient approximately I only to overcome ring and valve sticking tendencies in internal combustion engines, and including a co'nstituentiof the class consisting of halogens, sulfur and phosphorus.

2. An oil according to claim 1 wherein the oilsoluble soap is a metal soap.

3. An oil according to claim 1 wherein the synthetic acid contains at least about ten carbon atoms.

4. A freely liquid lubricating oil comprising mineral lubricating oil and a small quantity of an oil-soluble metal soap of a synthetic petroleum acid in quantity between about /z% and about 2%, the soap being such as not to impart grease like characteristics or appreciable increase in the I viscosity ,of the original oil and suffi'cient .approximately to control ring sticking tendencies anddeposition of resinous and varnish-like materials in internal combustion engines, and in-' cluding a constituent of the class consisting of halogens, sulfur, and phosphorus.

5. An oil according to claim 4 wherein mineral lubricating oil isanon-waxy'oil.

1 6. An oil according to'claim 1 wherein the in- 4 whereinthein- 1 wherein thein 1 v 11. An oil according toclaim 4 w rmth. in-

cluded constituent is phosphorus. I

' 12. A lubricating oil containing a small quantity between about /2% vandabout 2% and sumcient' to prevent '-ringand' valve sticking in internal combustion engines .of a metal soap of a chlorinated synthetic petroleum acid.

13. A lubricating oil according to claim 12 wherein the soap employed is such. as notto impart grease-like characteristicsor appreciable in-- crease in the'viscosity of the original oil and the oil is a non-waxy oil. v

14. A freely liquid lubricating oil comprising mineral lubricating-oil and a; small quantity of an oil-soluble soap of synthetic petroleum acid containing at least about ten carbon atoms per molecule, the soap being present in amount sum- .cientto overcome substantial deposit of gummy and varnish-like materials in internalacombustion engines, the soap being such as not to-impart' grease-like characteristics or appreciableincrease in the viscosity of the original oil, and including I a constituent of the class consisting of halogens, sulfur, and phosphorus.

15. An oil according to claim 14 wherein the includedconstituent is chlorine.

16. An oil according'to claim 14 wherein the included constituentissulfur- 17. An oil according to claim 14 wherein the included constituent is phosphorus.

18. An oil according to claim "14 wherein-the soap is formed from synthetic oxidation acid from refined mineral'oiland is present-in. quantity be-- tween about /2% v and about 2% and contains a halogen.

19. An oil accordingto claim 14 wherein the; soap is formed from synthetic oxidation acidirom refined mineral oil and is present in quantit'ybetween about /2%' and 2% and contains phosphorus. 1

20. An oil a'ccording'to claim 14 wherein the soap is formed from synthetic oxidation acid from refined mineral oil and is present in amount between about /2%. and about 2% and contains.

sulfur.

ULRIC B. BRAY.v