US2245649A - Lubricant and method of making same - Google Patents

Description

Patented June 17, 1941 LUBRICANT AND METHOD OF MAKING SAME Amerigo F. Caprio, Newark, N. 1., assignor to Celluloid Corporation, a corporation of New Jersey No Drawing. Application October 2, 1934, Serial No. 746,507

2 Claims. (Cl. 252-54) This invention relates to lubricants in the form of liquids or greases that contain a wetting,

, film forming material such asthe trior di-alkyl or. aryl or mixed esters of phosphoric acid an to the method of making same.

An object of this invention is the economic and expeditious production of a lubricant that may contain an oily or greasy material and a lubricating aid that is wetting, non-volatile, noninfiammable and of low congealing properties. Other objects of the invention will appear from the following detailed description.

It has long been known that the lubricants, whether oils or greases, having a petroleum oilbase or other oily base that are used today fall short of being the desired lubricants for two major reasons. The first reason is that the lubricants fail to maintain a lubricant film on bearing surfaces and especially on vertical bearing surfaces wherein a part of the bearing surface is always exposed, when such bearings are intermittently used or when such bearings are not used for a period of hours as when the machines are stopped during the night, etc. The second reason is that the lubricant film after being formed is not capable of withstanding great pressure which limits the use of small gears or bearing surfaces that could otherwise be employed. The speed with which the film is formed Y when applied to a new bearing surface is also important as well as other properties such as corrosiveness, penetrating power, oxidation or decomposition on exposure and/or high temperatures, catalytic action toward oxidation of the other ingredients of the lubricant, flash point, boiling point and freezing point and like factors.

I have found that all these properties, desired in a lubricant, may be attained or enhanced by incorporating in the lubricant, as a lubricant aid, a material of the class of .trl-esters of phosphoric acid. If desired and in some cases preferred, this ester may replace all or a large proportion of the petroleum or other oily material normally employed.

By employing this invention, liquid lubricants such as sewing machine oils on through toheavy automobile differential oils may be formed that have excellent penetrating power and that form films on metal surfaces that strongly adhere to same and which will withstand considerable bearing surface pressures.

By employing this invention greases such as cup greases, pressure cup greases, locomotive rod greases, etc., may be produced that not only stand up under pressures above 2,500 lbs. per square inch and that form films that adhere to metal surfaces for long periods of time but that have the further desired advantage of being homogeneous throughout and through a large range of temperature changes without a separation of the ingredients of such compounded greases.

By employing this invention other types of lubricants or materials of a lubricating nature may be formed that are of longer than normal life and that are more emclent due to the quickness of film formation and to the penetrating or wetting properties. rials are those that contain animal and vegetable oils such as driving journal grease, thread grease, cordage grease, wool lubricant, metal drawing lubricant, mill grease, boring oil, cuttingv oil, rust removing penetrating oil, textile oils, transformer oil, froth or flotation oils for concentrating ores and like miscellaneous ofls for special purposes. Whether these materials be used solely as a lubricant or as a lubricant with other predominating qualities they are nevertheless improved by employing this invention. ,Thus penetrating oil for loosening nuts on bolts, for use between the leaves of springs and the like are made more penetrating and a faster cutting of the binding material is had as well as a longer period of usefulness. Further oils or oily emulsions containing animal and vegetable oils are preserved against bacterial action and the aid acts also as an anti-oxidant preventing the materials from becoming rancid. In compounded materials containing waxes, oil and/or soaps the aid is of great advantage in holding the materials in homogeneous admixture through cold or hot temperature ranges. Further, the exceedingly high flash point, above 200 0., of most of the phosphoric acid esters recommended render them suitable for lubricating parts of machinery subject to high temperatures, such as in turbines. For example, a steam turbine lubricant may be formed from a mixture of chlorinated diphenyl and triaryl phosphate that will withstand very high temperatures and pressures.

A further use of this invention is in the preparation of upper cylinder lubricant or a lubricant to be added to gasoline for lubricating the upper section of a combustion cylinder. The aid may be used in direct admixture with the gasoline or first mixed with a light high flash test petroleum oil.

In accordance with my invention then I incorporate with oils or oily materials, as an aid to film formation, film strength and/or peneorganic esters of phosphoric acid may be employed. Thus broadly any of the organic esters of the phosphoric acids may be employed and Examples of such mateespecially those that are non-volatile at normal temperatures, water insoluble and chemically stable or inactive; Examples of the phosphoric esters that are applicable are the homogeneo aryl phosphoric acid ester as g phenols; the mixed aryl phosphoric acid esters 0 R1 P 0 0 R2 o as d where R1, R2 and R3 represent different radicals of the phenols; the homogeneous alkyl phosphoric acid esters as- 0R4 P040 R4 where R4 represents any alkyl radical; the mixed alkyl esters of phosphoric acid as 0R5 PO -O R6 D 0R1 where R5, R6 and R7 represent difierent radicals 1934), monocresyldiphenyl phosphate, trixylenyl phosphate, trinaphthyl phosphate, tribenzyl phosphate, triorthodiphenyl phosphate, phosphate esters of glycol ethers and the corresponding thio phosphates of some of the above compounds.

The tricresyl phosphate need not be necessarily pure, that is, it does not have to stand up with the tests and specifications described in U. S. applications Nos. 717,954 filed March 29, 1934 and 708,475 filed January 26, 1934. The tricresyl phosphate may contain up to 1% of free cresols. All that is necessary, for general lubricating purposes, is to wash the crude product with dilute caustic soda, or its equivalent after the reaction of the hydroxy or mixture of hydroxy compounds with the phosphorus compound -to remove objectionable impurities that might cause corrosion or else directly distill the where R refers to a radical of any one of the.

product and collect a suitable fraction. Further purification as described in said applications is optional. In forming or compounding a lubricant such as those used in automobiles a trace of oresol left in the phosphate ester is beneficial and still further increases the speed of film formation.

Any of the phosphate esters referred to above may be used alone or in mixtures of two or more of same or in combination with other well-known lead,

- ingredients of lubricating oils, greases, finishes and/or emulsions. Such ingredients may be:" paramn distillates such as kerosene, petroleum oil, paraflin, etc.; fats and oils, vegetable or animal such as caston'lard, pine oil, tallow, cocoanut, olive, neats-foot, sperm, rapeseed, palm, lanoline, glycerine, etc.; waxes, such as ozokerite, ceresine, carnauba, and including the artificial waxes such as halowaxes, etc.; resinous substances, used to harden greases, such as rosin, rosin oil, etc.; soaps with calcium and alkali bases functioning as solidifying or gelling agents; mineralsubstances, such as metallic soaps of aluminum stearates, aluminum oleate, mica, talc, graphite, stearic acid, etc., possessing unctuous properties; cellulose ester and ether derivatives as disclosed in U. S. Patent No. 1,931,485 and such materials as water, wood pulp, gypsum, asbestos, ground cork, etc.

Suitable emulsions may also be made according to the well-known methods, using sulphonated oils, trlethanolamine, etc. Thus compositions may be made which not only lubricate, but also cool, such as high speed cutting tool lubricant. In this embodiment, as well as in compounded greases, tricresyl phosphate or other esters of phosphoric acid are particularly useful, in addition to their lubricating properties, in binding into a compatible state substances, such as rosin soaps with waxes and/or oils. Thus tricresyl phosphate may make the ingredients of a compounded grease compatible with each other and prevent separation and consequent destruction of proper functions of the lubricant under performance. 7

As illustrations and not as limitations the following examples of formulae are given.

ExAMPLr: I

Cup grease Parts Fat 150 Quicklime 20 Petroleum Pale Oil viscosity at 100 F. 780 Tricresyl phosphate 40 EXAMPLE II Heavy graphite oil I Parts Cup grease of Example I 86.3 Steam refined cylinder stock 6.8 Ground graphite 5 Talc 2.5

To this material an additional amount of, say up to 10 parts of tricresyl phosphate may or may not be added.

ExAMPLr: III

Locomotive rod'cup grease I Parts Tallow 35 Sodium hydroxid 6.5 Steam refined cylinder oil 45 T ricresyl phosphate 5 Water. 10

The reaction is conducted in a. similar manher as in Example I or the tricresyl phosphate may be added in the cold after the other ingredients have been caused to react in a conventional manner as is well known to those skilled in the art.

EXAMPLE IV Lubricant for drawing and forming stainless steel Parts Heavy drawing compound 8 Hot water 8 Lithopone v 2 Flowers of sulphur 1 Cresylic acid J 0.2 Tricresyl phosphate 1 EXAMPLE V Crankcase lubricant Parts Mineral oil desired viscosity 100 Tricresyl phosphate 0.2-10

The tricresyl phosphate may be unrefined and contain traces (up to 1%) of free cresols. As tricresyl phosphate is itself 'non-hydroscopic, of substantial body, of high boiling point and film forming, it is a lubricant and may be used alone or in any percentage mixture with oil. On cost and solubility bases, however, from .2 to 10% of tricresyl phosphate is preferred.

The oleic acid and caustic soda reaction product may be replaced by any suitable soap. The final result is mixed with water or a water emul sion formed.

EXAMPLE VIH Artificial thread (regenerated cellulose) lubricant Parts Water white mineral oil 100 Heat's-root .0-10 Tricresyl phos'phate.-----.-. 10

Exsmm IX Cutting oils Parts Mineral oil 50 Rosin i 25 Lard oil 20 Tricresyi phosp 5 This may be formed into an emulsion with 3 to times as much water. This gives a quick EXAMPLE X Penetrating oil used for freeing rusted connectzons, bolts, etc. Parts Light mineral oi1 60 Kerosene 20 Secondary butyl alcohol 10 Tricresyl phosphate 10 Cresylio ac .5

EXAMPLE XI Transformer oz'l cent Tricresyl phosphate 1 to 100 Petroleum oil remaining EXAMPLE XII Non-greasy hard lubricant Parts Ethyl cellosolve Nitrocellulose (lacquer grade viscosity) 90 Aluminum stearate 15 Dimethyl phthalate 100 Tributyl phosphate 10D Monocresyl diphenyl phosphate 50- Ethoxyethyl acetate (cellosolve acetate) 50 or more The amount of the last named constituent may be varied to suit needs. I

EXAMPLE XIII Leather stufiiny Parts Ozokerite 6 Paraflin wax 8 Rosin n 40 Tricresyl phosphate l0 Mineral oil 40 EXAMPLE XIV Solid lubricant Parts Rosin 9 Machine 011 82 Caustic soda (40 B.) 9

The rosin and oil are heated to 100 C. and the caustic soda is slowly run into it with stirring, raising. temperature to 110-120 C. About 20 parts of 'triphenyl phosphate are then incorporated into the mixture.

I EXAMPLE XV Steam turbine lubricant 7 Parts Chlorinated diphenyl 50 Tricresyl phosphate 50 wetting and heat conveying lubricant for high speed tool cutting work.

The percentages may be varieddesired to obtain a lubricant of the desired consistency.

There are numerous formulae for lubricants for each purpose but for general purposes this invention relates to the replacing of a. part or all the petroleum or other oily material with an ester of phosphoric acid.

It is to be understood that the foregoing detailed description is merely given by way of illustration and many alterations may be made therein without departing from the spirit oi. my invention.

Having described my invention, what I desire to secure by Letters Patent is:

1. A steam turbine lubricant consisting 01' 50 parts of chlorinated diphenyl and 50 parts of a trlaryl phosphate.

2. A steam turbine lubricant consisting or 50 parts of chlorinated diphenyl and 50 parts of a trlcresyl phosphate. AMERIGO F. CAPRIO.