US2025517A - Penetrating lubricant - Google Patents

Description

7 Patented Dec. 24, 1935 UNITED STATES PENETRATING LUBRICANT Roy D. King, Jackson Heights, N. Y., assi'gnor to Socony-Vacuum Oil Company, Incorporated, New York, N. Y.,.a corporation of New York No Drawing. Application July 3, i934,

Serial No. 733,

9 Claims.

This invention has to do with lubricant oil compositions of the class known as penetrating oils, and has for a particular object the preparation of mobile and highly-penetrative oils of this class. Penetrating oils are most usually used where the moving parts to be lubricated are subject to intermittent movement, between which there are periods of rest, and in general where the unit loading is quite light. As an excellent example of a typical use, thelubricat-ion of all types of leaf'springs, such as are usedon automobiles,

maybecited- -In-these, the unit load is slight,

the periods of motion between adjoining leaves are intermittent, the clearances are quite close, there are no mechanical means for the retention of lubricant upon the lubricated surfaces, and the equipment to be lubricated is so exposed to atmospheric conditions that it is quite frequently heavily rusted. A proper penetrating oil should have balanced properties of low viscosity and high creeping power, so that it can penetrate between the leaves of the spring, even if they are rusted, it must-be sufliciently non-volatile that after reaching the point of use it will not evapcrate, and it must still have sufficient body-to lubricate when motion occurs. Combined with these, it must have a high enough preferential wetting power for the surface to be lubricated that it will displace rust, or penetrate between flakes of rust, and adhere to the underlying surface. Coupled with this last property is another .wide andtypical field of use of penetrant oils.

.This use isthe application of penetrating oils etc.

' is oil.

,to assembled parts rusted together, to make disassembly easier,such as nuts rusted on "bolts, Other typical and important uses. are for the lubrication of light fabricated metal equipment, such as the metal sliding sash on subway cars, and the like.

Penetrating oils may be broadly divided into two classesthose compounded without graphite, and those using graphite. In those not using graphite, some one of the liquid ingredients fulfills the lubricant function. In those using graphite, part or all of the lubricant function is assigned to graphite suspended in the oil. In the extreme case of this type, the penetrating oil is composed of graphite suspended in a carrier of penetrating nature, non-lubricating in properties. Any form of graphite which will stay in suspension may be used, the most popular graphite ingredient being the product known as Acheson oildag which is composed of deflocculated graphite suspended in oil, the whole being a paste-like product, only a minor amount of which This product is prepared in accordance with U. S. Patent 964,478, E. G. Acheson, and is hereinafter referred to as Acheson oildag.

This invention is based upon the discovery that pine fatty acids can be employed in the production of penetrating oils, and that when this is done, in the manner described below, penetrating oils can be produced which have notably superior properties of penetration between closely adj acent surfaces, of penetration through rust films, of adherence to lubricated surfaces, and the like. These pine fatty acids, which I have discovered to be useful for the purposes discussed herein, are apparently true fatty acids, obtained by fractional distillation of fatty matter separated from 10 pine wood in the course of" cooking by the alkaline process for the manufacture of wood pulp. As an ,indication of the nature of these compounds, I

may give the following test data.

Specific gravity 60/60 F 0.90-1.00 Moisture .(A.S.T.M. xylol) 0.'l0%-0.30% Saponification value (A.S.T.M.) 150-170 Mg KOH Iodine value (Hanus) 40-150 Titer of separated fatty acids (A.S.T.M.) 50-90- Color (A.S.T.M. colorimeter) Dark 8 or lighter Saybolt universal viscosity 100 F 100-600 g Flash (A.S.T.M. open cup) 250 F. Min.

Free fatty acids (A.S.T.M.) 90% Min.

Ash .content (ignition) "Trace-0.1%

From theabove data it may be seen that these pine fatty acids do not partake of the character of other commonlyused pine derivatives, but are true fatty acids. They are for instance quite distinct from the fpine oils which are essentially terpene-like in character, and from rosin, which is essentially abietic acid of varying degrees of a purity, abietic acid being of diiferent properties from those indicated above.

I have found that pine fatty acids may be advantageously used as an ingredient in superior penetrating'oils of either type. As examples of preferred formulae, the following may be cited:

Formula 1 g Percent Pine fatty acids 2 Kerosene 38 Light paraffin oil 60 Formula 2 5o Percent Pine fatty acids; 2 34 A.P.I. gas oil 96 Acheson oildag 2 Depending upon the nature of the use to be made of the oils, either ,of these formulae may be varied between wide limits. The pine fatty acids are chiefly concerned with those properties of the oil which enable it to penetrate, and to adhere. The minimum, amount of this ingredient seems to be approximately one per cent, with desirable properties increasing with per cent added quite rapidly up to about 3 per cent of pine fatty acids, and more slowly thereafter.

The point where increased benefit is oliset by increasing cost of ingredient appears to be about five percent, so the range of pine fatty acid ingredient in both types of formula would seem to be from one to five per cent. In the nongraphited oils, the respective proportions of kerosene and light parafiin oil may be varied widely from say per cent kerosene to 20 per cent kerosene, the mixture increasing in penetrating ability and decreasing in lubricating power with increases in kerosene percentages. The light paraffin oil indicated is a light lubricant of say seconds Saybolt viscosity at 100 F. Lubricants either lighter or heavier may be used, so long as the viscosity of the mixed product is not sufficiently great to defeat the penetrating object. A portion of this mineral lubricant oil might be replaced with an animal or vegetable lubricant oil, but these are not generally desirable due to their tendency to oxidize or polymerize and form gums and the like. Similarly in the graphited oils, the proportion of Acheson oildag may be varied between say one and ten per cent, although optimum results appear to be obtained at about the concentration noted, namely two per cent. In place of the 34 A.P.I. gas oil forming the bulk of the graphited penetrating oil, any non-viscous petroleum distillate, such as kerosene, might be used, and a portion of this ingredient might be replaced by a light lubricant. For instance I might add Acheson oildag to Formula 1 in amounts of from one to five per cent and produce a penetrating oil highly suitable ior many purposes.

Various laboratory tests may be applied to penetrating oils, such as tests aiming to measure surface tension, ability to spread upon metal surfaces, ability to enter capillary spaces, and the like, but these have been found to be singularly barren of results which may be used to predict performance in actual commercial use. To date, the only conclusive test of penetrant oils has been the ability to perform a given job better than competitive oils supplied for the same purpose at competitive price levels. Penetrating oils compounded with pine fatty acids according to this invention have successfully met this test of competitive field use. 1

The manner of compounding these oils is merely one of mixing the several liquid ingredients, no special equipment or precautions being necessary.

I claim:

1. A penetrative lubricant composition comprising pine fatty acids and a deflocculated graphite, and a preponderant proportion of a non-viscous petroleum distillate.

2. A penetrating lubricant composition comprising substantially equal proportions of pine fatty acids and defiocculated graphite paste, and a substantially preponderant proportion of a nonviscous petroleum distillate.

3. A penetrating lubricant composition comprising a non-viscous petroleum distil'ate to which has been added a proportion of pine fatty acids and a proportion of deflocculated graphite paste, the sum of the latter ingredients amounting to less than 10 per cent of the total.

4. A lubricant composition comprising Per cent Gas oil i 96 Pine fatty acids 2 Deflocculated graphite paste 2 5. A lubricant composition comprising a nonviscous petroleum distillate, a light paraffin oil and a small proportion of pine fatty acids.

6. A lubricant composition comprising Per cent Pine fatty acids 2 Kerosene 38 Light parafiin oil 60