Patented Mar. 27, 1951 2,546,421 UNITED STATES PATENT OFFICE 1. 2,546,421 WEAR INHIBITORs FOR IRON CARBONYL Earl Bartholomew, Birmingham, Mich., and How ard Clinton Cross, Columbus, Ohio, assignors, by direct and mesne assignments, to Ethyl Cor poration, New York, N. Y., a corporation of Delaware No Drawing. Application August 5, 1949, Serial No. 108,852 6 Claims. (C. 252-386) 2 This invention relates to antiknock mixtures Our preferred inhibitors are gasoline soluble and particularly to a mixture of iron carbonyl organic metallic compounds containing either and an inhibitor which reduces the engine wear 'Sulphur or oxygen through which the metallic caused by the use of the iron carbonyl. component is attached to the organic radical. Iron pentacarbonyl is a good antiknock agent 5 Among such inhibitors are the metal enolates and as such compares favorably with tetraethyl including acylacetonates, such as acetylacetonate lead. It has the economic advantage of being and propionylacetonates, alkylaminomethylene cheap. However, when a fuel-containing it is acetonates, such as methylaminomethylene ace 'burned in internal combustion engines, it has the tonates and ethylaminomethylene acetonates; disadvantage of causing wear in engine parts, O the "metal salts of carboxylic acids-including -particularly wear of the piston rings. The abra naphthenates, alkylphthalates, such as butyl Sive properties of iron carbonyl decomposition phthalate, and 2-ethylhexyl phthalate, and al products have effectively prevented its use com kenyl succinimates; and metal salts of alkyl mercially. . . . carbamic acids and their sulfur analogs, Such as It is, therefore, an object of this invention to 5 dibutylcarbamate, dibutylidithiocarbamate, di provide a wear inhibitor which substantially re- . amyldithiocarbarnate and di-(2-ethylhexyl)-di duces such engine wear. We have found that thiocarbamate. However, organic derivatives of certain gasoline-soluble organic metallic com certain of the metalloids, such as triphenyl arsine pounds - Substantially reduce the engine wear and triphenyl antimony also substantially reduce caused by the use of iron carbonyl. These com 20 the wear. Among the metals which can be used pounds contain a metal characterized by its . . in derivatives of the above organic compounds oxide having a “scratch hardness' of not more are copper, barium, strontium, cobalt, calcium, than 6, as determined by Mohs scale of hard zinc, antimony, silver, cerium, arsenic, indium, ness test. - Further, werprefer that the molecular nickel, titanium, manganese, thorium, thallium, weight of the organic radical contained in these 25 cadmium, tin, mercury, tellurium and Sodium. gasoline-Soluble organic metallic compounds be Preferably the metal in our organic metalic Wear between about 75 and 250. inhibitors is in the bivalent to tetraValent state. Although it is to be understood that we are Our invention can be further understood by not bound by any theory, it is our belief that referring to the following example: complex compounds are formed between the de 3. A quantity of fuel was prepared by blending Composition products of iron carbonyl and our in a commercial motor gasoline - a mixture of organic-metallic compounds. Such complex 0.312 gram of copper as copper methylamino Compounds are largely removed through the ex methyleneacetonate, 3 cubic centimeters of iron haust of the engine and there is a minimum of pentacarbonyl, and 21 cubic centimeters of a exposure to the vital engine parts such as the light saturated machine. oil, all quantities of piston rings. To the extent that these com added materials based on 1 gallon of fuel. This pounds are deposited in the engine, they are less fuel mixture Was burned in a four-cycle single abrasive than the iron oxide Which Would be cylinder internal combustion engine. for 150 formed in their absence. However, regardless of hours. The internal diameter of the cylinder any theory we have found that the organic me 40 and the weight of the piston rings of the engine tallic compounds having the above properties de were measured before and after this operation. crease the engine wear obtained with iron car The increase in diameter of the cylinder and the bonyl alone. Furthermore, in addition to such loss in weight of the piston rings are a measure properties, a good wear inhibitor should be stable of the wear obtained. In a similar operation in the presence of water and insoluble therein, keeping all quantities of materials used and en it should be stable to air at ordinary tempera gine conditions the same except that no wear tures and it should have “engine inductibility.' inhibitor was used, the same measurements for The term “engine inductibility' refers to the abil indicating wear were made. Comparing these ity of the inhibitor to be transported from the two operations as to amount of wear obtained carburetor into the combustion chamber and de 50 with and without an inhibitor and taking the pends simultaneously on Several physical proper wear resulting from the use of iron carbonyl ties, namely state of aggregation, volatility, solu alone as 100%, the operation using the copper bility, and Stability. The use of a small amount inhibitor resulted in only 39% of the wear ob of an inert hydrocarbon carrier such as one-half tained for iron carbonyl alone. Thus the addi to one per cent of Saturated machine oil in the 55 tion of a Small quantity of the copper inhibitor fuel enhances "engine inductibility.' to a fuel containing iron pentacarbonyl reduced 2,546,421. 3 4. the Wear by 61% compared with that obtained and the inhibitor employed. In all cases the With the same fuel without the inhibitor. amount of inhibitor used is Small and carries Using the same procedure and the Same between approximately 0.05 to 0.25 gram of amount of metal in the form of the organic de metal in the form of a metallic organic com rivative, a number of operations on other or pound to One cubic centimeter of iron Carbonyl. ganic metallic compounds were made. A Sum Our Wear inhibitors can be used in mixtures mary of these results is given in the following containing iron carbonyl and other antiknock table: materials such as lead antiknock compounds. Also a mixture of iron carbonyl and one of our 0. Wear inhibitors can be used as an auxiliary anti Per cent yar Scratch hard knock fluid in an engine operating on a leaded Namepentacarbonyl of inhibitor usedin the with fuel iron y:ElEE nestetERS I gasoline. Such an auxiliary fluid is introduced alone into the engine only at the times needed to meet its antiknock requirements. Beryllium acetylacetonate------540 9.0 15 Aluminun isopropoxide----- 336 9.0 We claim: Chronium acetylacetonate 130 8.0 1. An antiknock mixture consisting essentially Zirconium naphthenate--- 121 7.0 of iron pentacarbonyl and a Wear inhibitor in Uranium dibutyldithiocarbamate 129 6.5 Triethylborate.------125 7.0 an amount Sufficient to reduce wear in engine parts due to iron penta, carbonyl, Said wear in Iron carbonyl alone.------. 100 1 6.5 20 hibitor consisting essentially of at least one gaso Titanium naphthenate------72 6.0 line Soluble organic metallic compound having Triphenyl arsine------70 3.0 Nickel dibutyldithiocarbamate 66 5.5 the formula RxM where R is an organic radical Zinc naphthenate------63 4.0 Triphenyl antimony------61 ; 4.0 having a molecular weight between about 75 and Zinc dibutyldithiocarbamate 55 4.0 250, ac is a numeral from 2 to 4 inclusive, and M Copper naphthenate------54 3.5 is a metal whose oxide has a Scratch hardness of CopperCalcium naphthenate------methylaminomethyleneace - - - 47 3.5 not more than 6. tonate------39 3.5 Copper ethylaminomethyleneaceton- - 2. The mixture of claim 1 further defined in ate------37 3.5 that the organic metallic compound is a metal enolate. 1 Scratch hardness of iron oxide. 3) 3. The mixture of claim 1 further defined in Further, a visual inspection of other engine that the organic metallic compound is a metal parts such as journals, bearings and timing Salt of a carboxylic acid. chains, in the above operations showed a simi 4. The mixture of claim 1 further defined in lar reduction in wear when one of our inhibi that the organic metallic compound is a metal tors was used With iron carbonyl. s Salt of a carbamic acid. The Mohs “scratch hardness' test, data from 5. The mixture as defined by claim 1 in which which are given in the above table for the metal the organic radical has a molecular weight of oxide, is a standard one which can be made read from about 75 to about 250, and the inhibiting ily on the oxide of the metal desired for use. ingredient and the iron pentacarbonyl are in The hardness of the oxides varies between the 40 Such proportion that between about 0.05 and 0.25 limits of 0 to 10. This test is described in Dana's gram of Said metal is present for each cubic “Textbook of Mineralogy' 4th edition, by W. E. centimeter of iron pentacarbonyl. Ford, 1932. 6. The mixture as defined by claim 1 in which The above table shows the definite relation the inhibiting ingredient and the iron penta ship existing between the amount of engine Wear carbonyl are in such proportion that between and the scratch hardness of the oxide of the about 0.05 and 0.25 gram of said metal is present metal, which is by and large independent of the for each cubic centimeter of iron pentacarbonyl. organic radical attached to the metal. Although EARL, BARTHOLOMEW. the type of organic radical does have Some effect HOWARD CLINTON CROSS. on the engine wear, it is believed that it serves primarily as a means of getting the metal into REFERENCEs CITED solution in the gasoline, and transporting it into The following references are of record in the the combustion chamber of the engine. There file of this patent: fore, our invention is not limited to the specific, organic radicals given herein. From the above 55 UNITED STATES PATENTS table it is readily Seen that if metals are used Nunoer Name Date whose oxides have a Scratch hardness above 6, 1,903,624 Hurley ------Apr. 11, 1933 the amount of wear is increased over iron car 2,140,627 Hocking ------Dec. 20, 1938 bonyl alone. On the other hand, by using metals 2,160,880 Loane et al. ------June 6, 1939 the scratch hardness of the oxides of which is 2,177,561 Cook ------Oct. 24, 1939 below 6, a substantial reduction in the engine 2,266,325 Lazar et al. ------Dec. 16, 1941 wear caused by the iron carbonyl is obtained. 2,282,707 Cook ------May 12, 1942 Generally, the amount of iron carbonyl to be 2,305,627 Lincoln et al. ------Dec. 22, 1942 used as an antiknock in fuels for engines is be 2,324,770 Donlan ------July 20, 1943 tween about 1 and 3 cubic centimeters per gal 65 2,342,027 Waugh ------Feb. 15, 1944 lon of fuel. The amount of wear inhibitor used 2,343,756 DOWning et al. --- Mar. 7, 1944 depends on the amount of iron carbony used 2,398,282 . Bartholomew ------Apr. 9, 1946