US2372588A - Compounded mineral oil - Google Patents

Description

reeeeiea 2?, recs 2 352.5553

aa'zasss comrormnnn MINERAL on.

Robert G. Larsen, Berkeley, and Ernest W. Zublin, San Francisco, Ealift, assignors to Shell Development Company, San Francisco, Calif a corporation of Delaware No Drawing. Application June 19, 1940,

Serial No. 341,308

13 Claims. (Cl. 25239) This invention relates to compounded minamides. In the salt a metal and an acid derivaeral oils, and more particularly deals with relative of a pyridine or its homolgues or analogues tively high-boiling oils, such as lubricating oils, are combined, while in the amide the metal subelectrical oils, insect spray oils containing oilstitutes one or several hydrogen atoms in an soluble compounds of derivatives of pyridine, its amino radical of an amino pyridine or its homohomologues and analogues. Oils to which this logues or analogues.

invention is particularly applicable, though not For the purpose of this invention, we define necessarily limited, are those which, during their homologues of pyridine, quinoline, etc., as those useful lives, are not, or not completely, vaporized derivatives in which one or several replaceable or burned. hydrogen atoms of the aromatic nucleus are sub- It is known that the addition of certain salts stituted with radi cals, such as hydrocarbon, hyof carboxylic acids, sulfonic acids, etc.,to mindrcxy, carboxy, ether, hydrosulfide, sulfide, eral lubricating oils has beneficial effects in amino, imino, halogen, nitro, nitroso, nltrile, sulmany respects. Thus, it is known that the ringionic, etc., radicals. Analogues, on the other sticking tendencies of Diesel enginesor aviation 15 hand, are those compounds which contain difengines may be retarded or prevented by the ferent numbers of nitrogen in the nucleus, or addition of such salts to oils with which they whose nuclei contain different numbers of conare lubricated. Moreover, lubricating 0115 may densed aromatic rings, or the same number difbe improved with regard to sludge-forming tendferently arranged. Thus, chlorpyridine is a encies, viscosity index, pour point, oillness, etc., homologue of pyridine, while qulnoline or pyrimiby the addition of such salts. dine are analogues of pyridine.

It is a purpose of this invention to produce The metal amides of our invention are in genmineral oils having their properties improved in eral good sludge suppressors, many of them actcne r several respects y ing thereto metal ing as anti-oxidants while others function priderivatives of heterocyclic aromatic compounds marily as sludge dispersers. If they contain hycontaining nitrogen in the aromatic nucleus. It drocarbon radicals of relatively high molecular is another purpose to provide anti-ringsticking weights, they may be effective as pour point delubricants. Another purpose is to prevent or repressors, viscosity index improvers, anti-corrosion tard sludging of lubricants,electricaloils,etc.,duragents, etc. ing their use. Still another purpose is to provide The salts are useful as sludge dispersers, antia new class of fungicidal and insecticidal spray ringsticking compounds, oxidation retarders, oils. A futher purpose is to provide a class of anti-lacquering agents, pour point depressor-s, oil-soluble addition compounds for mineral oils viscosity index improvers, etc. All these propwhich are more effective in many respects, and erties will, of course, vary with the configurain some ways have entirely new properties as tion of the organic radicals, the types of substicompared withsimilar compounds heretofore tution radicals and the metal employed, one or suggested. more effects being predominant, while one or more We have discovered that a new class of metal of those enumerated above may be completely compounds wherein a metal is linked through a absent. metal-active radical containing metal and re- Most useful in lubricating oils are in general placeable hydrogen to an aromatic heterocyclic salts, the organic portions of which contain at nucleus consisting of nitrogen and carbon, at least one relatively long carbon chain having least one nuclear nitrogen being trivalent, have 10 or more carbon atoms. These salts are e!- especially useful properties when blended with fective detergents for anti-ringsticking propermineral lubricating O in relatively small q a ties. If their molecular weights are relatively I titles. One of the most outstanding properties high, e. g., above about 800, they also improve of these compounds is their ability to dissolve the V, I.

and finely disperse sludge, which thereby is mm It is known that the addition of various oildered harmless due to its being prevented from soluble metal compounds, such as salts of fatty settling or accumulating on surfaces in need of acids, naphthenic acids, aromatic fatty acids, lubrication. In this property our compounds are alkyl benzoic acids, petroleum sulfonic acids, etc.,

far more eflicient than the corresponding comrender lubricating oils corrosive. Thus the p ds a e on c ccyc rings. Moreover. the presence in lubricating oils of salts which combasic reacti nuclear nitrogen effects a conbine certain metals with certain of the acids siderable reduction in the harmful effect of corcauses'corrosiveness of the freshly blendedoil. rosive free acids which are often formed by which corrosiveness is aggravated as the oil is oxidation during the useful life of many of the used in internal combustion engines. Salts of oils. other metals, particularly when combined with The compounds of our invention may be divided acids of very high molecular weights, may result into two general classes, namely, salts and in oils which, when fresh and unused, are noncorrosive 01 may even be anti-corrosive toward the same bearing metals. However, upon use as crank case oils in internal combustion engines, these originally non-corrosive oils also become corro- SlVe.

The reason for the corrosiveness of the oils containing these salts is not clear, especially when the salts are substantially neutral or basic. Moreover, the rapid increase in the corrosiveness upon use of the oil is difficult to explain.

Whatever the reason for the observed corrosiveness may be, we have discovered that the salts of our acids are considerably less corrosive than the salts of the corresponding acids based on carbocyclic compounds, and if they are corrosive, the corrosiveness of the former is much more completely and more lastingly inhibited than that of the latter by the addition of oxidation inhibitors. I

As previously stated, the metal may be bound to the pyridine or its homologues or analogues, through a metal-active amino or acid radical or both. If an amino radical provides the only bond for the metal, then this radical must in its free state possess at least one replaceable hydrogen atom. Thus primary and secondary amino radicals may be suitable. Suitable acid radicals are, for instance, OH, --SH, COOH, CSOH, -SO2OH. These metal-active radicals may be attached directly to the aromatic nuclei or may be linked thereto through a bridge of one or several carbon atoms, which bridge may contain ether, thioether, imino ether, etc., linkages.

Particularly valuable metal compounds are obtained if the non-metallic portion contains two or more metal-active radicals, i. e., amino or acid radicals or both. Thus a, combination of an amino and an acid radical, or of an OH or SH and a carboxyl radical are particularly desirable, especially if the metal-active radicals happen to be separated from each other by a, bridge of 3 to 4 carbon atoms. This bridge may, if desired, contain ether, thioether or imino ether links. The metal-active radicals may be attached to the same or to different aromatic nuclei, at least one of which contains a nuclear nitrogen, and which are in close proximity to each other.

The position of the metal-active radical relative to the nuclear nitrogen atom may also be of some importance. In general, more stable metal compounds are obtained if this radical is separated from the ring nitrogen by two or three carbon atoms.

In order to exert their beneficial effect, the metal compounds must be soluble in hydrocarbon oils in eflfective quantities, and this may in most 4 instances require the presence of oil-solubilizing groups, such as one or several alkyl, naphthenyl, aryl or arallwl, etc., radicals. Such radicals may be introduced into the aromatic nucleus, for example, by reacting suitable chlorinated hydrocarbons, such as chlorinated kerosene, gas oils, lubricating oils, extracts or raflinates thereof, wax, or of pure hydrocarbons, such as butanes, pentanes, hexanes, octanes, dodecanes, cetanes, etc., or corresponding alcohols or oleflnes, with the pyridine compounds, its homologues or analogues, in the presence of a suitable condensing catalyst such as a Friedel-Crafts catalyst, sulfuric acid, phosphoric acid, P205, etc. The products of this reaction comprise derivatives of pyridine, or its analogues, wherein at least one hydrogen of the nucleus has been replaced by the hydrocarbon radical. The solubilizing radicals may themselves, if desired, contain substitution radicals, such as halogen, hydroxy, ether, hydrosulflde, thioether, amino, imino, etc., radicals. Moreover, they may be connected to the pyridine or homologous nucleus through an ether, thioether or imino ether linkage.

Further, the pyridine or analogous nucleus may, in addition to the acid 'or amino radical, contain other substitution radicals, such as halogen, nitro, nitroso, nitrile groups. 1

The active radical or radicals which links the metal to the pyridine compound or its analogue may be introduced by various known reactions. For example, SOaH radicals may be introduced by simple sulfonation. Sulfonated compounds so produced may in turn be treated with alkalis at high temperatures to convert them to the corresponding hydroxy compounds. Amino derivatives may be obtained by treating chlorinated pyridine or analogue with ammonia. Likewise, thiopyridines may be produced by treating chlorinated pyridines with KSH. Pyridine carboxylic acids may be made by oxidation of alkyl pyridines with KMnO4, etc.

In producing our compounds, we may start out with substantially pure pyridines, quinolines, etc., I

or we may use mixtures of different analogues, such as mixtures of quinoline and isoquinoline, or pyridine and quinoline, or alkylated pyridines, quinolines, isoquinolines, etc. A suitable source for the production of such mixtures are cracked hydrocarbon oils, such as cracked naphthas, kerosenes, gas oils, etc.

In the table below, a, series of formulae of pyridine derivatives and analogues of pyridine are listed which are suitable for producing our oil-soluble salts. In these formulae, R represents a hydrocarbon radical which may contain substitution groups; n and m are integers, the sum of which is not greater than the number of replaceable hydrogens in the pyridine or analogous nuclei; X is an acidic or amino radical.

Pyridines Quinolines and isoquinolines ethers, thioethers, imino ethers, etc., equivalent to those of the pyridines.

Acridines, anthrapyridines, phenanthridines R. I X- Derivatives equivalent to those shown above.

Carboxylic acids N N N N \N coon a. x. R, -x.. Rn Rn 5 V N coon Pyrlduine Pyrlmldine Pyrazin N N x... coon \N N OR a. --x.. R.

. a /N I N Clnnollne Phthslazin R T R I I /N\ coon RF 1? D j on OK 4 4 N /N Qulnazoline Qulnoxaline N C 0 011 N coon Rn X'" NH: W u k NHZ N-N N v N Phenazone Phenazine Rn W /\/N -COOH Below are listed some compounds, the'salts of COOH Rn which are preferred for our purpose: y OH N N N I 0H l coon h R, R R T -coou U l/ n. w

H OH Allwl 3- and 4-hydroxy pyridines N coon N N\ R 40 H B. n I etc.

on OK Suljomc acids N N AlkylB-h droxy Alkyl 3-hydroxy A1kyl 4-hydroxy 4o N Quinn e qulnollne qulnolme t/l I N SH soul so H I N V 3 N SE n. Mixtures of metal derivatives of the above compounds may be used if desired. Furthermore, in

SH addition to our compounds, we may also incor- A l2-thio Alkyli-thio A1k yl8- thio porate in lubricating or other mineral oils con- 1 Home qlmwme qumome ventional anti-oxidants, pour point depressors, corrosion inhibitors, extreme pressure agents, blooming agents, dyes, etc.

N N R De pending upon the particular type of im- R provement which is to be achieved by the metal A compounds of our invention, different metals may H H 0 be combined with the amino or acid radicals of N N our compounds. Thus we may incorporate in the O mineral oils salts of the alkali metals, i. e., lithium, sodium, potassium; alkali earth metals, 1. e., 5 H Mg, Ca, Sr, Ba; earth metals, i. e., Al, Ti; heavy N N metals, 1. e., Cu, Ag, Zn, Cd, Hg, Sn, Pb, As, Sb, Bi, Cr, Mo, w, Mn, Fe, Ni, Co, etc. In lubricating oils we usually prefer the compounds of the poly- O 0 valent light metals, i. e., Mg, Ca, Sr, Ba, Al. Com- H H pounds'of metal which are toxic to the lower forms of life, e. g., of Pb, Ag, As, Sb, Tl, etc., and

particularly Cu, are very valuable in insecticidal and fungicidal oils.

, In many instances, we also may employ salts of relatively strongly basic amines such as quaternary ammonium bases, i. e., tetramethyl, tetramethyl ethyl, dimethyl diethyl, trimethyl benzyl, dlmethyl ethyl benzyl, methyl triisopropyl, triisopropyl benzyl ammonium bases; or piperidine, guanidine. etc. Very useful are salts of these strong basic amino compounds with sulfonic acids of pyridine, its analogues and homologues.

atom being separated from each other by 3 or 3 carbon atoms.

8. A sludge retarding mineral oil composition 7 containing dissolved a small mum of an oil- The amounts of our compounds to be incorpoheterocyclic aromatic compound, the aromatic six-membered nucleus of which consists of carbon and nitrogen, at least one nitrogen being trivalent.

2. The composition of claim 1 wherein the amount of the metal derivative is from .1%-10%.-

3. A sludge retarding mineral oil composition containing dissolved a small amount of an oilsoluble metal salt of a monocarboxylic acid of a heterocyclic aromatic compound, the aromatic six-membered nucleus of which consists of carbon and nitrogen, at least one nitrogen being trivalent, saidaromatic compound having at least one replaceable nuclear hydrogen substituted by an oil-solubilizing radical.

4. The composition of claim 3 wherein said solubilizing radical is an aliphatic radical of at least 10 carbon atoms.

5. A sludge retarding mineral oil composition containing dissolved a small amount of an oilsoluble metal salt of a monocarboxylic acid of pyridine.

soluble metal salt of a monocarboxylic acid of an aromatic compound comprising not less than one heterocyclic aromatic six-membered nucleus which consists of carbon and nitrogen, at least one nitrogen being trivalent, said compound containing at least two metal-active radicals separated from each other by a bridge of 3 to 4 carbon atoms.

9..'1'he composition of claim 8 wherein said bridge contains a linkage selected from the group consisting oi ethers, thioethers and imino ether linkages.

10. A sludge retarding mineral oil composition containing a small amount of an oil-soluble heterocyclic aromatic metal compound having .6. A sludge retarding mineral oil composition containing dissolved a small amount of an oilsoluble metal salt of a monocarboxylic acid of quinoline.

7. A sludge retarding mineral oil composition containing dissolved a small amount of an oilsoluble salt of a monocarboxylic acid of a, heterocyclic aromatic compound, the aromatic sixmembered nucleus of which consists of carbon and nitrogen, at least one nitrogen being trivalent, said metal being linked to the aromatic compound through an active radical, which in its free state contains metal-replaceable hydrogen, said active radical and nuclear nitrogen the formula wherein R is an oil-solubilizing radical, Me is a -metal equivalent of hydrogen and 1|, is an integerwhich is not greater than the number of replaceable hydrogens ot the aromatic nucleus.

11. An improved mineral oil composition containingdissolved an oxidation-inhibiting amount of an oil-soluble metal carboxylate having the formula Rn (300L112