US2234915A - Lubricating oil - Google Patents

Description

Patented Mar. 11, 1941 UNITED STATES PATENT osrlce or to Sun Oil Company, poration oi New Jersey Philadelphia, Pa., a cor- No Drawing. Application October 11, 1939, Serial No. 298,979

4 Claims.

My invention relates to lubricating oils and greases and comprises such an oil or grease to which has been added a halogenated nitrile or a halogenated nitrile-hydrocarbon mixture; I have succeeded in producing such halogenated. products from petroleum acids and paraffln wax and my invention also comprises such products, which are useful for purposes other than as addition agents to lubricating oils and greases. Such products are viscous oils, soluble in hydrocarbons in all proportions, having particularvalue as addition agents to lubricating oils intended for use under severe operating conditions, such as in hypoid gears. The difliculty with which such nitriles are hydroliz'ed makes them especially valuable as lubricants, as they do not readily form corrosive products as do the esters of the fatty acids. Owing to their stability against hydrolysis they may be added to greases without substantially altering the alkalinity of the grease.

, The process of producing these products and the lubricating oil to which they are added will first be described as applied to a mixture of petroleum acids and petroleum hydrocarbon as a starting material. By petroleum acids I intend to be understood as including such acids as usually occur in petroleum and particularly naphthenic acids which are formed or isolated during the refining process according to a number or patents of the prior art, such as the patents to Hughes et al. No. 2,056,913, Angstadt No. 2,013,619 and No. 1,931,880, or Alieman No. 1,931,855, No. 1,694,461 and No. 1,694,463.

A mixture of such petroleum acids with petroleum hydrocarbons is delivered to a reaction vessel made oi. glass, stainless steel, enameled lined metal or any other material that will not be at" tacked by the products to be reacted. Preferably the vessel is provided with a long narrow neck or cylinder in order to provide for expansion and particularly to aiford a longer period of contact between'the gas and the liquid,

After the reaction vessel is loaded with the above mixture, it is heated until a temperature of from 200 C. to 400 0. (preferably about 350 C.) is attained. Ammonia is introduced at the bottom of the reaction chamber, preferably in a finely divided state, as, for example, through a tube provided with a diffusion plate; or a rotating stirrer, such as a turbo mixer, may be used.

At the top of the neck or cylinder provision is made for condensing and collecting any water that is split olT, as well as any other material which is volatile or is carried over by entrainment. A convenient arrangement includes a condenser provided with a water jacket. The water is separated and the organic material returned to the reaction chamber.

The reaction may be carried on at atmospheric pressure, but if the boiling point of the starting material is below the desired reaction temperature, a higher pressure is desirable. A pressure of about 75 lbs. per square inch is suificient in most cases. The reaction may be carried out in the presence of dehydrating catalysts such as silica gel, alumina, thorium oxide, or like substances.

The reactions which take place between the petroleum acids and ammonia in forming nitriles involve three stages: firstthe formation of the ammonium salt of the petroleum acids; second, splitting oil. water from this ammonium salt and forming the amide; and third, splittin off water from the amide to form the nitrile. These stages may be represented as follows:

(1) RLOOH NH: RCOONHi Petroleum acid Ammonia Ammonia salt of petroleum acids Water Amide of petroleum acids R.CO.NH2 heat H20 R.CN

Nitrilc of petroleum acids When water is no longer split oiT the reaction is complete.

Instead oi utilizing as a starting material a mixture oi petroleum acids and petroleum hydrocarbons, oil-free petroleum acids may be used. These may be separated from a mixture oi hydrocarbons and acids by any desired method, such as by known methods of extraction with solvents. Or the hydrocarbons may be separated from the original mixture of hydrocarbons and alkali metal soaps, as by known solvent extraction, and the soaps then acidified. Purified petroleum acids having a saponification number oi about 182.5 are produced by known methods and these may be used as the starting material. Other petroleum acids having smaller saponification numbers and containing varying percentages oi hydrocarbons are also produced by known methods and these also may be used as starting materials. For example, petroleum acids are known that have a saponification number oi 130 and contain about 40% of hydrocarbons. Any starting mixture of petroleum acids containing hydrocarbons should not contain over of hydrocarbons.

If purified petroleum acids are used as a starting material the ammonia treatment above described is applied and the same reactions occur. The resultant product is the same except that with one starting material nitriles are formed and with the other starting material a mixture of nitriles and petroleum hydrocarbons are formed.

Nitriles may also be produced, by the method above described, from a mixture 01' unoxidized parafiin wax and oxidation products, preferably I from a crude oxidation product of paraflin wax containing esters, acids, alcohols, other intermediate oxidation products and unoxidized hydrocarbons, as set forth in an application filed by me October 11, 1939, Serial No. 298,980. The nitriles thus formed may be separated from the hydrocarbons with solvents inwhich the nitriles are soluble and in which the hydrocarbons are nearly or quite insoluble. However, the removal of the hydrocarbons is usually unnecessary. When nitriles are produced from the crude oxidation product of paraffin wax they usually contain about 30% of unoxidized hydrocarbon.

Nitriles may also be formed from paraffin wax by simultaneously passing air, or other oxygencontaining gas, and ammonia through molten paraffin wax, as described in the application hereinbefore mentioned.

Preparatory to the next step the nitriles may or may not be purified by known methods. Whether they are purified or not, and whether or not they are in admixture with petroleum hydrocarbons, they are dissolved in a suitable inert solvent such as carbon tetrachloride and chlorine passed through the material until the desired amount of chlorine is taken up. The reaction vessel may be of essentially the same type as that used for the preparation of the nitriles. The chlorine is introduced at the bottom of the reaction vessel in a fine state of subdivision, so that the reaction takes place rapidly. This may be done by a difiusor or a stirring device such as a turbo mixer. The

temperature of the reaction mixture is kept below about 60 C. The use of a solvent is desirable because the chlorinated nitriles are very viscous, and it is diificult to get intimate contact between the partially chlorinated nitrile and the chlorine. Any excess chlorine and hydrochloric acid may be removed by blowing the product with air, by heating under a vacuum, by washing with water, or by treating with a neutralizing agent such as quick-lime or sodium carbonate. Use of one of the latter two reagents removes some of the loosely bound halogen, and such treatment may be preferred when the product is to be subjected to high temperature conditions. If desired, the product may be treated with decolorizing materials, such as filter clay, to improve the color. Usually it will sufiice, after the desired amount of chlorine is introduced into the mixture, to remove the reaction product from the reaction vessel and wash it with water until neutral. The carbon tetrachloride or other solvent is recovered by distillation. The distillation may be conducted under reduced pressure.

In the unsaturated nitriles the chlorine is largely taken up by addition, whereas in the substantially saturated nitriles, such as the nitriles from the oxidation products of parafiln wax, the chlorine is largely taken up by substitution, hydrogen being split out of the molecule to form hydrogen chloride.

Where an exceptionally high chlorine content is desired, catalysts, such as iodine or iron, should be used.

While it is uneconomical to utilize halogens other than chlorine, it will be understood that nitriles embodying my invention may contain any halogen, namely, fluorine, bromine or iodine.

The amount of chlorine that may be introduced into the nitriles may vary from 5 to 50%, although it is rarely that it is desirable, for any purpose, for the nitrile to contain less than or more than 45%.

The chlorinated nitrile may be added to lubricating oils in amounts varying from .1% to 25%, the amount introduced depending upon the chlorine content of the nitrile and the purpose for which the lubricant is to be used. If the lubricant is to be used under severe operating conditions, it is desirable to use a greater quantity of a chlorinated nitrile which contains a comparatively small amount of chlorine, such as 10-20%. These compounds are more stable than the chlorinated nitriles containing the maximum amount of chlorine.

In claiming the addition of the chlorinated nitrile to lubricating oil I intend that lubricating oil should have its broader signification and thereby include grease.

I do not herein specifically claim a halogenated nitrile or nitrile-hydrocarbon mixture derived from parafiin wax or from a mixture of parafiin wax and its oxidation products, nor specifically the lubricating oil containing any of such products as an addition agent, nor the specific process of producing such lubricating oil, nor the process of producing such halogenated nitrile or halogenated nitrile-hydrocarbon mixture from paraffin wax; the same forming the subject matter of another application for patent hereinbefore mentioned.

What I claim and desire to protect by Letters Patent is:

1. A lubricating oil to which has been added a minor percentage of a nitrile, derived from petroleum and halogenated, containing over 5% and less than 50% of the halogen.

2. A lubricating oil to which has been added a minor percentage of a nitrile, derived from petroleum acids and halogenated, containing over 5% and less than 50% of the halogen.

.3. A lubricating oil to which has been added a minor percentage of a halogenated nitrilepetroleum hydrocarbon mixture derived from petroleum and containing over 5% and less than 50% of the halogen.

4. A lubricating oil to which has been added a minor percentage of a halogenated nitrilepetroleum hydrocarbon mixture derived from a mixture of petroleum acids and petroleum hydrocarbons and containing over 5% and less than 50% of the halogen.

SAMUEL EDWARD JOLLY;