US2114836A - Grease - Google Patents

Description

tente pr. 19, 1938 STATES.

PATENT OFFICE amass No Drawing. Application August 9, 1934,

' Serial No. 739,107

2 Claim.

This invention relates to the preparation of greases, and more particularly to greases containing a grease base of saponified oxidized pariit wax.

g I is well recognized that oxidized paraflin wax contains acids and saponifiable esters. It has heretofore been proposed to separate the acid content of the oxidized wax, and to utilize the separated acids for the preparation of soaps in the manufacture of lubricants. It has also been proposed to incorporate in a lubricating oil a small proportion of oxidized paraffin wax to increase the adhesiveness of the liquid oil.

We have discovered that by saponifying oxiis olized paramn wax, which contains a sufiicient proportion of saponifiable matter, a suitable base material for the preparation of greases is obtained. This base material constitutes a substitute for the fats and fatty acids ordinarily employed in greases, and efiects material economy by thus replacing in whole or part the more expensive fats and fatty acids. This also obviates the additional processing steps inherent in the former practice where the acids are separated from oxidized paramn wax, as well as enabling the bulk of the oxidized wax to be employed. The invention is distinguished from-the former practice of adding a small quantity of oxiwax to a lubricating oil, in that the oxidized m) wax is saponified, and then is employed as a base material for the preparation of a grease as distinguished from an oil.

In accordance with the present invention, parw wax is air blown at elevated temperatures, 35 generally in excess of 250 F., for a period of time until a substantial content of saponiflable matter is formed in the wax by oxidation. A predetermined quantity of the oxidized wax is then introduced into a conventional grease mak- M ing kettle, and a proportionate quantity of an alkaline saponifying agent, such as lime, caustic soda or mixtures thereof, is added. The mass is agitated at elevated temperatures until the added alkali has neutralized and saponifled the oxidized M wax to form soaps in admixture with the unsaponiflable content of the oxidized wax. The agitation may be accomplished by mechanical stirring, air blowing, or both, during the saponiflcation treatment. As the batch begins to o thicken, a lubricating oil is added from time to time to keep the contents of the vessel sufliciently fluid to prevent stalling of the stirring device and aflord proper agitation. Additional quantities of lubricating oil are ,ilnally added to bring the batch to the desired consistency.

The following is a specific example of the method of producing the grease base of the present invention. A charge of parafiin wax was maintained at a temperature of about 295 to 330 F., while air was introduced in fine streams at the bottom of the vessel. The oxidation was allowed to proceed for a period of approximately nine hours, although a somewhat shorter or longer oxidation time can be employed. The properties of the material throughout the latter From the above oxidized wax, blown for nine hours and having a saponification value of 204, lime, soda, and mixed lime and soda grease bases were prepared'by adding substantially the chemical equivalent amounts of alkaline saponifying material to batches o; the oxidized wax in'a grease kettle, and agitating while heating by the introduction of steam to the steam jacket of the kettle for approximately an hour. The resulting grease bases were employed in the manufacture of greases by mixing a lubricating oil with the bases in the grease making kettle, while heating and agitating, the grease base being substituted in whole or in part for-the customary tallow or other fat or fatty oil as conventionally employed.

By way of example, a lime base grease was prepared by adding a predetermined amount of the oxidized paraflin wax prepared as outlined above to a previously cleaned grease kettle. To the kettle was then added a suspension of lime and water, and the contents of the kettle were stirred while heat was applied from the steam jacket oi. the kettle. After the batch began to thicken, suflicient pale lubricating oil was added to keep the contents of the kettle sufficiently fluid for proper agitation. Additional quantities of oil were added from time to time until the desired consistency was attained. The proportion of water added in the lime suspension, or in addition thereto, was considerably in excess of that ordinarily employed in the manufacture of ordinary cup grease, and was suflicient to provide at least 10% by weight of water in theflnished product, which enabled a grease of smooth texture.to be obtained. A soda base greeserlas prepared in a similar manner, except that in this case the water content of the finished prodnot was around 4% by weight or above. The proportions of soap to lubricating oil may vary within wide limits according to the type and characteristics of the grease desired, and may approximate the proportions customarily employed where tallow or other usual fats or fatty oils are used.

While satisfactory greases may be prepared by substituting the saponifled oxidized parafiln wax in whole for the fats and fatty acids customarily employed, it is to be understood that various proportions of fats or fatty oils of animal or vegetable origin can be included. Other metallic base greases, such for example as a lead base grease by the employment of litharge, can be prepared from the oxidized parafiln wax in the manner of the lime and soda base greases described above. The hardness and consistency of the greases can be controlled by variations in the proportions of lubricating oil and soap, as is well understood in the grease making art.

' atlases Obviously many modifications and variations of the invention, as hereinbefore set forth, may be made without departing from the spirit and scope thereof, and therefore only such limitations should be imposed as are indicated in the appended claims.

We claim:

1. A lubricating grease comprising essentially a mineral lubricating oil, and saponifled crude oxidized parafiin wax consisting of soaps of caponiflable constituents of the oxidized paraffin wax admixed with non-saponifiable constituents remaining therein.

2. A lubricating grease composition consisting essentially of mineral lubricating oil and saponified crude oxidized paraffin wax, said saponifled crude oxidized paraffin wax containing a mixture of unsaponifiable constituents present in the oxidized wax and one or more soaps, oi the class oi. lime and soda, of the saponiflable constituents.

BENJAMIN GALLSWORTl-IY. JOSEPH R. SCANLIN.