US2419144A - Antiseize and sealing compound - Google Patents

Description

Patented Apr. 15, 1947 UNITED STATES PATENT OFFICE ANTISEIZE AND SEALlNG COMPOUND John P. Kelly, Toledo, Ohio, assignor to Champion Spark Plug Company, Toledo, Ohio, a corporation of Delaware No Drawing. Application December 18,, 1944, Serial No. 568,788

This invention relates to a compound for use between close fitting metal surfaces to effect a gas tight sealing of the joint therebetween and which internal engines in which mounted.

In the use of aviation engines, considerable difiiculty is encountered by reason of the sealing or. lubricating compounds, commonly used between the cylinder head and spark plug threads, becoming thinned and thus releasing and flowing from the threads under the high temperature conditions to which subjected. This thinning action not only destroys or lessens the joint sealing characteristics of the compound but permits the contacting metal surfaces to seize and prevent relative movements of the surfaces without injury thereto. 7

The primary object of the invention is the provision of a new and useful compound of the character described, particularly adapted for use in high temperatures between threaded surfaces to prevent seizing of the surfaces so that a comparatively easy separation or relative moving of the surfaces may be effected without injury thereto, and also being of a character to prevent thinning and flowing of the lubricant or sealing agent from between the surfaces under high temperature conditions.

Other objects and advantages thereof will be apparent from the following detailed description of the invention.

A compound embodying the invention that has given highly efficient results in connection with spark plugs used in connection with the mounting of spark plugs in aviation engines comprises the following ingredients mixed in substantially the proportions noted:

Per cent Aviation lubricating oil 38 Stearate (lithium or barium) 12 Talc (magnesium silicate) 21 Graphite (preferably flake) 23 Corrosive preventive concentrate 6 The oil component is preferably a refined oil 3 Claims. (Cl. 252-23)- 2: having the following specifications: gravity, A. P. I, 215*; flash point, 495 F; to- 500 F; Saybolt v viscosity 9'? to 102 seconds at 210 F.; viscosity index, 104. Oil-s having substantially these constantshave been found satisfactory in the present composition.

The corrosive preventive concentrate may be made from the following specifications:

Parts (a) Petroleum lubricating oil of Saybolt viscosity 750 seconds at 109 F (b) 7 Oil solution of sodium salts of oil soluble sulphonic acids, formed on treating petroleumoils with concentrated sulphuric acid (c) Degras (a fatty oil that has been extracted from sheep wool, and neutralized with calcium oxide) 5 This ingredient may be omitted in compounds used on surfaces that will not corrode.

The lithium or barium stcarate is used in powder form and is preferably of a fineness to pass through a U. S. standard 140 mesh sieve. The lithium stearate which has been used with good results in the composition has a melting point of 215 to 221 C.

The tale or magnesium silicate is used in powder form and is preferably white and of a fineness to pass through a U. S. standard 325 mesh sieve and should be free of gritty matter.

The graphite, which is preferably flaked, should be free of gritty matter and in the finished compound be preferably of a fineness to pass through a U. S. standard -170 mesh sieve.

It is found in practice that while the preferred compound is mixed in the proportions abovenoted, any of these may be varied within the following limits:

Per cent Aviation lubricating oil 34-44 Stearate (lithium or barium) 9-15 Talc (magnesium silicate) 17-25 Graphite 19-27 Corrosive preventive concentrate 0-10 In preparing the mixture in small quantities, the following procedure has been followed: The oil compound and the corrosive preventive concentra-te are first mixed together and during slow mixing of these the stearate is added and the mixing continued long enough to completely disperse the stearate in the mix. The slow mixing eliminates throwing-out of the stearate. The talc and graphite ingredients are added while 3 the oil, corrosive preventive concentrate and the stearate are being stirred and the stirring should continue until a smooth homogeneous mass is obtained. Thorough mixing is essential. The ingredients should be in a cold or unheated state while mixing.

An important advantage of this compound'is that the ingredients will remain in suspension for a much longer time than other compounds for similar purposes, of which I am aware. Further, the compound, due to a jelling action under high temperatures, does not flow as freely as other compounds for the purpose and, therefore, effects a more efiicient seal and also has a greater tendency to cling and remain on the threads or other surfaces to which applied.

The oil, stearate, graphite and talc eachhas a particular lubricating quality, and when these ingredients are combined they have such a cooperative action as to form a highly efiicient seal ,and an anti-seize for threaded connections of metal parts, such for instance as spark plugs in aviation engines, subject to use under'high tem- .perature conditions, and wherein it may be desirable to disconnect the parts after. use for inspection or replacement.

Having thus described my invention, what I claim as new, and desire to secure by United States Letters Patent, is:

1. A composition of matter for use between metal joint surfaces to prevent seizing of the metal joint surfaces to prevent seizing of the surfaces comprising 34 to 44% petroleum lubricating oil, 9 to lithium stearate, 11 to 25% talc, and 19 to 27% flaked graphite.

3. A composition of matter for use between metal joint surfaces to prevent seizing of the surfaces comprising 34 to'44% aviationjlubricating on; 9' to 15% lithium stearate, '17 to 25% talc, and 19 to 27% flaked graphite thoroughly mixed, the stearate being capable of passing through a substantially 140 mesh sieve, the tale being capable of passing through a substantially 325 mesh sieve and the graphite in the finished surfaces after heating and cooling cycles .com-

compound being capable of passing through a -170 mesh sieve. JOHN P. KELLY.

REFERENCES CITED The following references are of record in the file of this patent:

-' UNITED STATES PA'I'ENTS OTHER REFERENCES Klemgard (Lubricating Greases), 1937. in Div. 64, page 722.)

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