US2189788A - Lubricant - Google Patents

Description

Patented Feb. 13, 1940 um'rso STATES PATENT orrics Serial 1937 4 Claims.

The present invention relates to greatly improved lubricants for various uses and to the process of producing the same.

One of the biggest problems faced in the op- 5 eration and maintenance of machinery or any device including parts movable in contact with one another is that of lubrication. It is generally understood that present day lubricating oils including refined petroleum hydrocarbons,

fish oils, and vegetable oils, do not satisfactorily meet all of the demands put upon them in automobile and other industrial uses.

Broadly speaking, the invention involves the addition of a compound or compounds to an I ordinary lubricant base. The lubricant thereby produced is far superior to the base lubricant treated by the addition of the compound or compounds in that it has a greater spreading power on metal surfaces, adheres more tenaciously to metal surfaces, thereby imparting greater lubrication under pressure, and materially reduces the problem of condensation and its efiEects. Furthermore, the improved lubricant is not affected by the normal temperature changes ordinarily g5 encountered in use to the same extent as the base lubricant and the improvement in this regard is substantial. Also, a lubricant produced in accordance with my invention has effective protracted corrosion preventive properties, counteracts the effects of thin oxide films present prior to the application of the lubricant, has a low surface tension, and is free from graphite, heavy metals and their salts.

Broadly speaking, the invention contemplates the use of or combination of aliphatic amino compounds and those cyclic amines exhibiting aliphatic amine properties, so that it will be understood the expression aliphatic amino compound includes those cyclic amines exhibiting such properties. Forexample, dimethyl amine, mono, di, triamyl amine, hydroxy aliphatic amines such as mono, di, tri, ethanol amine, amylolamine, aliphatic poly amines such as ethylene diamine. The aliphatic amine compound is added either alone or in combination with other ingredients, as will be set forth hereinafter, to an oil which will be referred to as the base lubricant. I have discovered and demonstrated that an ordinary oil can be greatly improved by the addition of one or more of the aliphatic amino compounds either alone or in combination with other ingredients, the ingredients added to the oil being dependent upon the particular use or uses to which the oil or other lubriga cant is to be put. Therefore, lubricants designed Renewed November 5,

for a wide range of uses can be produced in accordance with my discoveries. For example, a very excellent crank case or cylinder oil can be created by adding one or more aliphatic amines to an ordinary lubricating oil intended for this a purpose. Also, automobile spring lubricants, automobile differential and transmission lubricants, mining machinery and equipment, steam engines,

A and in fact practically all kinds of lubricants can be made by incorporating aliphatic amino com- 10 pounds with present day lubricating mediums. With some of the aliphatic amines, it has been found that a very satisfactory lubricant can be made by the addition of only the amine, while in other cases the amine can be treated with a w fatty acid and/or an alcohol, and/or ketones, and/or cyclic esters. In still other cases, the addition of nitro, nitro and nitroso reducing compounds may be used to advantage. In addition to controlling the viscosity or S. A. E. rating 20 of the lubricant produced in accordance with my invention by proper selection of the base lubricant used, the mode of combining the materials can be so handled to produce either a thicker or a thinner body lubricant from the same base as lubricant.

As an example of one particular lubricant that can be produced in accordance with my invention and that has been found to give extremely satisfactory results, the following is set forth. so

Step (A) .Heat about one mole weight of an aliphatic amine, for example about 149.15 lbs. of triethanol amine or approximately 61.06 lbs. of mono ethanol amine and the like about 0.77 mole weight of a fatty acid, for example approximately 5 225 lbs. of oleic acid, or 227 lbs. of stearic acid or the like; then heat this mixture at elevated temperatures within the practical range below the boiling point of the particular amine which is present. It is desirable to stir the mixture during 40 the reaction or 'the ingredients can be heated separately and then run through a colloidal mill.

Step (13) .Mix approximately 0.87 mole weight of an inorganic nitrite, for example lbs. of sodium nitrite, which serves as a reducing agent, 5 and about 14 mole weight of hot, nearly boiling water.

Step (CL-Mix approximately 0.017 mole weight of an orgaric nitro redu ing compound such as the nitruso naphthols, nitro phenols, amino-nitroso-phenyl-hydroxylamine, hydroxy nitro compounds, nitro phenols, and the like, in a suitable solvent. One specific example consists in dissolving about 2.8 lbs. of alpha-nitrosobeta-naphthol in about 63 lbs. of denatured al- '5 cohol or about 25 lbs. of an ester of phthalic acid such as dibutyl or diethyl phthalate. Th nitrocompound is more readily dissolved at slightly elevated temperatures, although excessively high temperatures should not be resorted to as this promotes decomposition of the nitro compounds.

Step (D) .Combine the mixture formed by Step (B) with the mixture formed by Step (C), and then add this combination to the mixture formed by Step (A), mixing thoroughly. This then gives what I term the base material which may, for the purposes of this application and for the sake of convenience, be referred to as the transmuting material. The resulting transmuting or base material'is then added to a suitable grade lubricating oil.

In the production of a spring lubricant, excellent results can and have been obtained by adding the base material to a steam refined, Bright stock, or other suitable grade of oil, although obviously the invention is not in any way limited to the addition of the base material to any particular oil. However, it may be mentioned that the base material above described has been added to about 40,000 gallons of a steam refined sulphur free oil having a viscosity at 100 of 3390 and at 210 of 200-205, and extraordinarily satisfactory commercial results have been obtained. Large manufacturers of automobiles have purchased and are using substantial quantities of this particular mixture for spring lubricating purposes.

As stated above, the viscosity of the lubricant can be controlled in the manner of combining the base material and the oil so that either a high, medium, or low viscosity lubricant can be obtained. Very excellent results are obtained when about 65 parts of the transmuting or base material are added to about 400 parts of the lubricating oil, although obviously widely different proportions can be used.

Specimens covered with the above oil and base material mixture were exposed on the roof of one of the largest automobile manufacturer's research laboratories for about five months and'at the end of this time there was absolutely no evidenceof corrosion. Other tests showed that the oil and base material mixture maintained its lubricating qualities approximately ten times as long as the oil not including my transmuting material. Many other severe tests were made and in all cases the oil and base material mixture gave results far superior to the oil proper without the base material.

To produce a thinner lubricant, the oil is heated first and the base material then added. On the other hand,if a thicker lubricant is preferred, the base is heated first and the oil is added gradually during agitation, while to get a medium bodied lubricant the base is heated first and the oil is added a little faster than in the case when a thick lubricant is made. Practically the same method of control is employed when a colloidal mill is used instead of a mixer. With the use of the colloidal mill, the base and oil are heated separately to the desired temperatures. or may be premixed and heated depending upon the viscosity desired.

Since lubrication problems vary greatly, it is necessary for best results to produce different types of lubricants; that is, lubricants having somewhat different characteristics to meet diiferent problems. Where the need for a particular property or properties is pronounced, I have found that my improved lubricant can be modified to emphasize the desired property, so that by proper control of ingredients any specific lubricating problem can be coped with. In all cases, however, the use of an aliphatic amino compound is resorted to and the method of processing and specific materials added are controlled for the purposes Just stated.

In the case of producing a lubricant for automobile springs, in addition to the properties already mentioned, more friction is desirable, and this can be obtained by increasing the relative amount of water and amino fatty acid compound and/or by adding suitable resins and/or gums. On the other hand, where it is necessary or desirable to impregnate porous metal with a lubricant at elevated temperatures, glycerin or some high boiling point solvent, such as ethylene glycol, may be utilized in lieu of the water. Where dry lubrication, so to speak, is desired, waxes and gums can be incorporated with the base material instead of oil by selecting the proper solvent and amino fatty acid with which it may be peptized, although some gums and waxes are soluble in amino compounds themselves. Alcohol may be replaced by esters of phthalic acid, ketones, or other equivalent solvent materials. In those cases where it is necessary to avoid emulsification with water such as in steam motors, mining machinery, and the like, I have found it advisable to use some solvents other than water, glycerin, or alcohol, and an amino fatty acid compound capable of emulsifying the solvent with the oil and which will not emulsiiy water, for example, triamyl amine, oleate, or stearate.

Many present day lubricants contain either free fatty acids or other chemicals capable of reacting with some bearing materials forming either soaps or chemical compounds, thereby ruining the bearing; for example, in case of copper lead bearings when in contact with lubricating oils containing free oleic acid which forms a soap with the lead and causes material damage. My base material can be modified for this particular use by changing the amount of the fatty acid.

In the production of a lubricant to be applied with a pressure gun, for example, chassis lubrication, it is of course necessary to have a high viscosity lubricant, so-called solid lubricant. Pressure gun lubricants, shipping compounds, and drawing compounds, can all be made by proper control and/or by incorporating suitable soaps and the like.

As specific examples of some of the different types of lubricants and the manner of producing the same in accordance with my invention, the following outline is given:

Example (1).-To produce a crank case oil, an aliphatic amine or a mixture of aliphatic amines can be added to the base lubricant. Triamyl amine or trihexyl amine, or triheptyl amine are examples of the aliphatic amines that can be added to an ordinary oil such as a steam refined oil to give very satisfactory results for crank case or equivalent purposes.

Example (2).To produce a spring lubricant where a lower surface tension is desired than in the case of the crank case oil and where greater adhesion to the metal serves to advantage to keep the springs well lubricated, a mixture of an aliphatic amine or mixture of aliphatic amines and a fatty acid can be added to the oil base. The oleic, acid is an example of a fatty acid which will work satisfactorily in this mixture.

Example (3).-To produce another mixture that is also useful as a crank case lubricant or as a differential and transmission lubricant, a mixture of Examples (1) and (2) plus an alcohol can be used. Butyl alcohol is mentioned as one form of alcohol that has given satisfactory results. This mixture, when added to the base oil, offers advantages in solving condensation problems and in decreasing surface tension. This mixture also lessens condensation troubles and the addition of the alcohol assists to reduce the solidification point. As a modification of this example, Example (2) plus alcohol results in an excellent rear end lubricant free from condensation troubles.

Example (4) .-Contemp1ates the use of nitro, nitroso, hydroxy-nitro, and nitroso compounds. A nitro reducing compound such as nitroso naphthol added to Example (1) appears to act with the aliphatic amines as do the nitroso phenols. The use of butyl alcohol or dibutyl phthalate apparently serves to promote a reaction between the nitro compound and the aliphatic amino compound. This mixture can be used as a crank case oil, and it has been found that the nitroso compounds aid in reducing or removing iron oxide films from the metal to be lubricated. Experiments indicate that the addition of the nitronitroso compounds increases the life of the lubricant in crank case, difierenti al, and rear end uses.

Broadly speaking, the mixture of Example (4) possesses advantages. over Examples (1), (2), and (3) in that among other properties it not only neutralizes acids and other corrosive agents, but it removes oxide films that may be present on the metal, thus always insuring practically oxide free and well lubricated surfaces.

To illustrate the number of considerations that must be borne in mind in the production of a truly satisfactory lubricant, I will discuss a lubricant designed particularly for spring lubrication purposes, although of course it is to be clearly understood that my invention is in no way limited to any one type of lubricant or lubricants for any one particular field of use.

Spring lubricants should contain a substance or substances capable of acting as a rust preventative which will act or be efiective over a considerable period of time. Some attempts have been made to incorporate inorganic inhibiting compounds in oils but, so far as I have been able to ascertain, the use of inorganic inhibitors in lubricating oils has not proven satisfactory. Oxidizing agents, such as potassium dichromate, have been added to oils as inorganic inhibiting compounds. However, when applied to metal, iron oxides are formed which tend to prevent further corrosion provided the film of iron oxide is not broken at any point, but should, as is usually the case, the film become broken, the result is that the underlying metal is exposed and consequently the rate of corrosion will be greatly increased due to localization of the action of absorbing acidic gases giving to the lubricant the property of protecting metal from the action of carbon dioxide and other acidic gases and also neutralizing any free acid that might possibly be present. It also has a property of acting on mild iron oxide. The alpha-nitroso-beta-naphthol mentioned as one example is capable of forming complex salts. This aids in maintaining the metal free from corrosion.

When the sodium nitrite is added in the manner suggested (potassium or other alkali and alkaline earth nitrites), the lubricant has the property of gradual absorption of active oxygen and therefore there is little, if any, opportunity for metal oxidation. Furthermore, the compounds activity in this regard is practically coexistent with the life of the lubricant itself. It is my opinion that the nitro (nitroso, etc.) compound, in addition to forming complex salts with the iron salts, has the property of improving the lubricating value of the base oil. It will of course be appreciated that there may be some reactions that take place when all of the ingredients are mixed togther that we are not entirely familiar with or do not thoroughly understand, although the above expressions have been made to give my opinion as to what takes place based on the practical results which have been obtained. It may also be added that the lubricant has the further advantage in that the possible chance for the formation of electrolytic couples is practically absent. The above lubricant not only functions as a lubricant, but also serves as a corrosive preventive in addition to being able to counteract the effect of thin oxide films which may be present on the parts to be lubricated before the application of the lubricating material. These properties are so pronounced that the material may even be used to coat battery ground cables, brake cables, and similar devices where the prevention of corrosion is of outstanding importance.

,In my opinion, a desirable lubricant must be free from graphite, and it will be noted that no graphite is included in my improved lubricant consisting of the base lubricant and transmuting or base material. When a graphite lubricant is applied to spring leaves, for example, the lubricent is squeezed out under the pressure applied to the spring leaves and the residual graphite is forced into the minute pores of the metal, with the result that an electrolytic couple is then es-' tablished. This results in the liberation of hydrogen which partially escapes, and no doubt part of it becomes deposited in the pores of the spring leaves. The pressure normally present accelerates the well known effect of embrittling of the iron and, in addition, the iron is corroded and pitted by the electrolytic action just mentioned.

It is clear that in those cases where inorganic inhibitors are added to lubricants, the formation of protective films of iron oxides is depended upon which are readily broken thus permitting excessive and accelerated corrosion of the exposed areas.

organic materials included in my lubricant do not depend upon the formation of oxide films, and furthermore substances which are normally capable of causing corrosion are counteracted before the metal surface itself is reacted with those substances.

In view of the ability to compound my oil mixture to readily emulsify water, if so desired, the

In contradistinction to the em-] ployment of inorganic inhibiting. agents, the

acid compounds in the manner above suggested,

a lubricant is formed which will give utmost of protection to metal surfaces and actual use has shown it to be very satisfactory as an engine lubricant such as in the crank case of the ordinary automobile as a spring lubricant, spring grease, spring cover grease, transmission and differential uses, cup grease, and general chassis lubrication of automobiles, as drawing and shipping compounds, and in fact in all cases where a good lubricant is desired. In making the cup grease or a lubricant of similar characteristics, soap may be added to the mixture, while the drawing and/ or shipping compound can be produced by simply diluting the oil and transmuting material mixture with water. Over three hundred thousand pounds of my improved lubricant have been sold and used in different forms.

It will of course be understood that the viscosity of the lubricant is controlled not only by the ingredients added, but also by the manner of mixing, depending upon the particular use to which the lubricant is to be put.

I claim:

1. A non-corrosive lubricant comprising a lubricating oil having incorporated therein a small amount of a free aliphatic amine base having a boiling point of not less than 45.3" i for coun teracting corrosion, absorbing acidic gases, and neutralizing acids, and a. small amount of an organic nitro reducing compound for maintaining the functioning of the amine.

2. A non-corrosive lubricant comprising a lubricatlng oil having incorporated therein a small amount of a free aliphatic amine base having a boiling point or not less than 453 F. for counteracting corrosion, absorbing acidic gases, and neutralizing acids, and a small amount of a nitroso compound for maintaining the functioning of the amine.

3. A non-corrosive lubricant comprising a lubricating oil having incorporated therein a small amount of a tree aliphatic amine base having a boiling point of not less than 45.3" F. for counteracting corrosion, absorbing acidic gases, and neutralizing acids, and a small amount of a nitroso compound and an inorganic nitrite for maintaining the functioning of the amine.

4. A non-corrosive lubricant comprising a lubricating oil having incorporated therein a high molecular weight fatty acid and an aliphatic amine bash having a boiling point of not less than 45.3" F., the molecular proportion of said base being in substantial excess of the molecular proportion of the fatty acid whereby there is present a small amount of free aliphatic amine base for counteracting corrosion, absorbing acidic gases, and neutralizing acids, and a small amount of an organic nitro reducing compound for maintaining the functioning of the free amine.