US2258309A - Lubricant - Google Patents

Description

Patented Oct. 7, 1941 LUBRICANT John C. Zimmer, Hillside, .N. J., assignor to Standard 011 Development Company, a corporation of Delaware No Drawing. Application April 7, 1938, Serial No. 200,681

10 Claims.

The present invention relates to the art of lubrication and more particularly to lubricants containing fillers, which lubricants are used particularly for metal working operations such as stamping, drawing, forging and the like. The invention will be fully understood from the following description.

Lubricants for metal working processes such as forging, stamping, drawing and the like are generally of the type containing inert fillers. These fillers are of the type of talc, chalk, calcium carbonate and the like and serve the purpose of preventing metal-to-metal contact under high pressures which are encountered in the said processes.

It has been found that much better results can be obtained by'us ing as fillers certain inof the fatty. material to soap. Where 20 to 35 parts by weight of the fat are employed, 30 to 50 parts of mineral oil would be used with from 10 to 40 parts'of water.

organic salts which possess extreme pressure or anti-weld properties. The particular salts contemplated herein are particularly the phosphates, sulfides and borates of polyvalent metals, especially those of the second group of the Periodic System, especially calcium, zinc and lead salts, and also similar salts of tin. Whilev any of the above salts which are substantially insoluble both in water and oil may be used, it is preferred to use the salts of zinc, calcium and lead.

It has been found that the particular salts mentioned hereinabove perform the various functions which were perform'edby the previous inert fillers, but at the same time they are found to endow the lubricating compound with the ability to withstand considerably higher pressures without metal failure, seizure or scoring. Inaddition they appreciably reduce the friction. facilitate the flow of metal into the die recesses and thus reduce the power requirements for the fabricating operations. They likewise give the work an attractive, burnished appearance which is not obtained with the well known inert fillers, and reduce the frequency of splits, cracks, or other blemishes in the drawing or stamplngs.

In making up the present compounds, the ordinary procedures can be used. For example, a fat such as tallow, palm oil, degras, or fatty oil or fatty acids of vegetable, animal or mineral origin is first saponifled with an alkaline solution such as caustic soda or potash or with lime, and thereafter additional water and oil are worked into the compound so as to make up an emulsion of a thick, pasty type. It is found desirable not" to completely esterify the fatty substances and the amount of alkali added is preferably only sumcient to convert '75 to 80% The oil used is a lubricating oil and distillates or residuals may be used, depending on the particular use. The compound made up as before is a thick, white to dark brown paste having a consistency ranging from mayonnaise to heavy greases. ually stirred in while heating gently. The amount of the filler may vary from about 2 to 40% of the mixture, depending to some extent on the type of the particular filler added and the use for which it is employed. Generally speaking, however, from 5 to 10% is suihcient for most purposes.

The above mentioned compounds may be used as such in the case of heavy drawing or stamping. The paste is spread on the work in a thin layer and after the operation contemplated has been performed, the compound may be scraped off and recovered for'reuse. It is also possible,

- in the case of light drawing and stamping, to

use a fluid mixture which is obtained by diluting the compound as made above with a relatively large amount of water. In this condition the material is'a free flowing emulsion.

While the borates and sulfides may be used as indicated above, it is preferred to use phosphate compounds and zinc and calcium. acid phosphates are the most useful.

The following example is given to illustrate the method by which the compound is made and to demonstrate its superiority over drawing compounds of the present type.

Example I mixture are then added 2, 5 and 10% by weight of zinc phosphate, 5 and 10% by weight of calcium acid phosphate and 10 and 20% by. weight of calcium carbonate. The primary compound without the addition of filler and the same to which the various fillers had been added were then tested for their film strength on an Almen The filler is now added and is gradmachine, under strictly comparable conditions.

In the table below, the composition 01' the compound is given together with the number of weights it was able to carry on the Almen machine:

Almen data on drawing compounds Almen test, No. of wts.

Percent filling material added carried HM HHHHH u-wmmGcuano-MA In the above test it will be noted that the compound without fillers carries only 4 weights. The improved compounds, however, containing zinc and calcium acid phosphates respectively were very efiective. 2% oizinc phosphate,-for example, were able to carry 13 weights whereas the compound containing 5% of ordinary calcium carbonate could only carry 6 weights, and doubling or quadrupling the amount of the filler only raised the load carried to 11 weights. It also should be noted thatthe compounds containing 5 and of the said phosphates did not fail in the Almen test. These compounds carried the full 15 weights for which the machine is designed and the test does not indicate pressures at which such compounds actually would fail.

The present invention is not to be limited to any theory of the action of the improved filling materials nor to any particular filling compound or ratio of ingredients, but only to the following claims in which it is desired to claim all novelty inherent in the invention.

I claim:

1. An improved lubricant for metal working processes comprising an aqueous emulsion of a mineral lubricating oil to which has been added a filler consisting of a polyvalent metal salt 01' an 2 azuaaoe acid selected from the class consisting of phosphoric, boric and hydrosulfuric acids, which salt is substantially insoluble both in oil and water.

2. A lubricant according to claim 1 in which the inorganic salt is a salt of a metal of the second group of th Periodic Table.

3. A lubricant according to claim 1 in which I the salt is calcium acid phosphate.

4. A lubricant according to claim 1 in which the acid is boric acid.

5; An improved lubricant for metal working processes comprising a thick, pasty, aqueous emulsion of a mineral lubricating oil to which is added a solid filler consisting of a divalent 7. An improved lubricant for metal working processes comprising an emulsion of 20 to parts of partially saponified fat, 35 to 50 parts of mineral oil, 45 to 15 parts of water, and 2 to.

20 parts of a polyvalent metal phosphate.

8. An improved lubricant for metal working processes comprising an emulsion of 20 to 35 parts of partially saponified fat, 35 to 50 parts of mineral oil, 45 to 15 parts of water, and 2 to 20 parts of a salt of lead selected from the group consisting of phosphates, borates and sulfides.

9. An improved lubricant for metal working processes comprising an emulsion of 20 to 35 parts of partially saponified fat, 35 to 50 parts of mineral oil, to 15 parts of water, and 2 to 20 parts of tin phosphate.

10. An improved lubricant for metal working processes, comprising an aqueous emulsion of a mineral lubricating oil to which has been added as a filler a polyvalent metal salt of phosphoric acid, which salt is substantially insoluble both JOHN C. ZIMMER.

- in oil and water.