US2038688A - Solid lubricant - Google Patents

Description

7 heat supplied to melt the Patented Apr. 28, 1936 i SOLID LUBRICANT Gavin R. Taylor, Montreal West, Quebec, and

Richard N.

Smith, Toronto, Ontarl assignors to McCall-Frontenac Montreal, Quebec, Canada 0, Canada, Oil Co. Limited,

No Drawing. Application July 10, 1933, Serial No. 679,710

. 3 Claims.

This invention relates to solid lubricants for the lubrication of locomotive journals and other bearings operating at high speeds and high temperatures and particularly to dehydrated lubricatingv compounds having a water content, less than one percent and a melting point of the order of 400 F. or over.

One object of this invention is to provide an improved dehydrated lubricating compound which, in comparison with the similar compounds now in use, has increased hardness and a dense consistency that enables it to bemore readily formed into blocks or cakes by pressing or molding and to retain its shape during all ordinary handling or shipping.

Another object is to provide a dehydrated lubricating compound having an improved fibrous structure which improves the retention of the lubricating oil by the sodium soap to provide at all times a proper lubricating film over the working parts to which the lubricant is applied.

In the practice of this invention dehydrated lubricating compounds of improved oil retaining and lubricating properties have been successfully produced in accordance with the following formula:

Per cent Heavy distilled naphthenic petroleum lub cating oil 30.8 Residual naphthenic petroleum lubricating oil 13.6 Stearic acid 14.0 Oleostearine 28.0 Caustic soda 6.6 Water 7.0

The above ingredients are compounded in an open-top fire heated kettle according to the following procedurez-The mineral oil and stearic acid are introduced into the kettle and suflicient fat. The caustic soda in solution in the water is then added while stirring the contents of the kettle with a paddle agitator. The heating and agitation is continued until the water content of the mixture is less than one percent. The oleostearine is thenadded and the mixture heated to approximately 400 F. to bring it to the condition of a fibrous paste suitkettle. In the cooled compound produced in accordance with this invention is characterized by a melting point of loss finished product is sub- Per cent Sodium soap 47.7 Free alkali (as NaOH) 0.6 Petroleum oil 48.1 Water 0.5 Glycerine 3,1

The presence of the small amount of glycerine resulting from the saponification of the oleostearine is found to improve the lubricating properties of the compound in some respects. The use of heavy distilled naphthenic petroleum lubricating oil and residual naphthenic petroleum lubricating oil in place of the unfiltered cylinder stock generally used in the manufacture of dehydrated lubricating compounds has been found to give improved grease structure and lubricating properties. The use 01' both distilled heavy naphthenic oil and residual naphthenic oil while not absolutely essential is recommended because of the improved effects obtained.

In the foregoing description the term nap thenic lubricating o is used in the sense in which it is commonly employed in the trade to indicate lubricants produced from naphthenic crude oils. It may also be explained that .the viscosity characteristics of the naphthenic lubricating oil used in accordance with our invention are similar to lubricants manufactured from crude oils produced along the gulf coast of Texas, U. S. A. Such lubricating oils are characterized by a high viscwity at 100 F. for the same viscosity at 210 F. when compared with paraflinic lubricants. It is also important to note that whereas the lubricating oils previously used in the manufacture of dehydrated driving journal lubricants have a viscosity index varying from fifty (50) to one hundred (100), the viscous naphthenic lubricating oils which are preferably used in accordance with our invention have a viscosity index of from zero to thirty (30). The term viscosity inde is widely used by the industry to classify oils from varying crude oil sources by means of their viscosity characteristics and the particular method which we have used for determining the viscosity index of the naphthe method of procedure which fall within the scope and spirit 0'! the invention as defined by the appended claims.

Having thus described our invention, what we claim is:-

1. A solid dehydrated lubricant for locomotive journals and the like containing, as its principal ingredients, highly viscous naphthenic petroleum oil having a viscosity index of less than thirty and a sodium soap made from animal fat and stearic acid saponifled with caustic soda, the oil and soap together constituting approximately 95% of the lubricant and being present in substantially equal proportions together with less than one percent water and from one to four percent glycerine.

2. A solid dehydrated lubricant for locomotive driving journals and the like-containing, as its principal ingredients, highly viscous naphthenie petroleum oil having a viscosity index of less than thirty and a sodium soap 'made from animal fat and stearlc acid saponified with caustic soda imder conditions conducive to retention of glycerine in the finished product, the oil and soap together constituting approximately 95% of the lubricant and being present in substantially equal proportions together with not more than one percent 01 water and from one to four percent glycerine.

3. A solid dehydrated lubricant for locomotive driving journals having substantially the follow- 15 ing analysis:-

Per cent Sodium soap- 47.? Free alkali (as NaOH) 0.6 Highly viscous naphthenic oil 48.1 20 Water m5 Glyceri 3.1

GAVIN R. TAYLOR.