US2237682A

US2237682A - Grease containing asphalt

Info

Publication number: US2237682A
Application number: US37755A
Authority: US
Inventors: Lester W Mclennan
Original assignee: Union Oil Company of California
Current assignee: Union Oil Company of California
Priority date: 1935-08-24
Filing date: 1935-08-24
Publication date: 1941-04-08
Anticipated expiration: 1958-04-08

Description

imalzenizd a GEASE CUNTM Lester W. ll/iclilennan, ichmond, habit, assignor to Union Oil homnany oi Walii'ornia, llos 1ngeles, @allii... a corporation oi haliiornia No Drawing. application august a l, 1005, serial No. 071,055. Renewed .lianuary 10, 1030 5 lDlaiins.

This invention relates to greases oi the cup grease type, particularly to cup greases in which asphaltic materials are included.

For certain uses, such as in saw mills and the lilre, it has been found that ordinary cup greases, such as calcium soap grease, are not entirely satisiactory, whereas if a refined asphalt is included an additional stickiness and body is imparted to the grease, and where an oxidized or airblown asphalt is added in suitable proportions, it produces a firmer grease of much better body which has a more plastic structure, as well as an unusually blaclr luster, both oi which features render the grease highly preferable. For example, about oi an airblown asphalt added to a calcium soap grease results in a grease of such suitable torture and consistency.

e invention may therefore be said to reside in a cup grease, that is, a calcium soap grease,

containing a quantity oi oxidized asphalt, and

particularly an airblown asphalt in quantity sumcient to provide a iirmer more plastic structure than that imparted by steam blown or ordinary residual asphalts. The invention applies also to other greases or oils thickened with soaps and containing oxidized asphalts for the purposes stated.

asphaltic cup creases and the like of the stated character possess their improved consistency apparently by reason oi improved adhesive characteristics.

in preparation of an asphaltic cup grease according to the present invention, the calcium soap grease is made up according to approved conventional practices, the soap stocks being preferably a mixture of about 85% prime tallow and oleic acid, although other soap stocks may be used as obvious to the skilled grease malrer. Saponification is efiected in an open kettle with hydrated lime, together with a small quantity of mineral oil if desirable to improve worlring consistencies. Following saponification, the required amount of mineral oil for the desired grease is introduced and worked into the soap, and water is added to attain the necessary hydration as required in calcium soap greases, whereupon airblown asphalt is added with agitation until the asphalt has been completely assimilated by the hot grease. The amount of asphalt so introduced is preferably such as to constitute about 15% of the product. The temperature is then adjusted and the grease is drawn into containers.

A desirable alrblown asphalt is an asphalt which has been produced by airblowing, as dis Mitt-155 13. by the standard ball and ring method a. S. '1'. M. D-30-26, a penetration of 30-40 at 77 F. by the standard a. S. '1. M. method 13-5-25.

Harder or softer specimens however, may be used.

The mineral oil used may be any appropriate oil for grease-making purposes such as one having a Saybolt Universal viscosity at 100 F. of 200 seconds. The amount of oil in the final product will depend of course upon the consistency of the grease desired. Thus, in a typical sample of light grease there may be about 72% oil and 12% calcium. soap and reaction products together with about 1% water, whereas for a medium grease the oil content may be about 68% and for a heavy grease about the soap and water contents being correspondingly increased.

a finished light cup grease according to this invention possesses the following typical composition:

Per cent by weight Calcium soap 11.2 Glycerin 1.0 Mineral lubricating oil (Say. Vis. 200 sec.

at 100 F.) 71. Free fat 0.3 Free alkali 0.01 Airblown asphalt as above described 15. 0 Water 0.0

Heavier greases are made merely by decreasing the proportion of oil with a corresponding increase in the proportion of soap and water to about 58% oil and 2% water for a heavy grease.

A satisfactory operating procedure comprises charging to a kettle about 740 lbs. of a soap stock consisting of about prime tallow and 15% olelc acid, together with a little over lbs. of hydrated lime, about 25lbs. of water, and if desired, a small proportion of the mineral oil, for example about 200 lbs. This batch is heated with agitation until saponification is complete. This may be a matter oi. two or three hours. The temperature will be run up to about 230 F. The presence of the oil enables the soap to be kept in a soft condition without the formation of lumps. Having obtained proper saponification, part of the oil is added rapidly and worked into the soap until the temperature is reduced to about 200 F.

and the soap content is reduced to perhaps 25% or 30%. Thereupon the small quantity oi. [water required in a calcium grease is added for proper hydration of the grease and in the case of lighter greases the rest or the lubricating oil is then worked in. The above described airblown asphalt is then added to the grease in small lumps and the grease is paddled until the asphalt has been completely taken up. The temperature of the grease is then adjusted to a proper drawing temperature, as determined by factors well known in the art of cup grease manufacture, and drawn oil into containers.

In addition to producing calcium soap greases containing airblown asphalt above described, other metal soaps may be employed to produce corresponding cup greases, such variations being made in water content and certain steps of procedure as would be well understood by the skilled grease maker.

Grease as produced according to this invention 7 has imparted thereto by the asphalt an unusually black luster that cannot be obtained with other asphalts, and at the same time a firmer, more plastic, and generally more desirable grease structure is obtained than with other asphalts. Also such oxidized asphalts produce greases more suitable for various heavy uses than non-asphaltic or other asphaltic greases. Not only may the ordinary solid greases be produced, but the socalled liquid greases may also be produced by increasing the quantities of lubricating oil, and for some uses the quantity of lubricating oil may be further increased to yield an oil only slightly thickened by relatively small amounts of soap and asphalt. Except as the quantity of lubricating oil varies the consistency, the charactertistics imparted by the asphalt are substantially the same throughout the mentioned range of lubricants;

The addition of asphalt as above described is particularly effective in the case of greases which are resistant to water, such as calcium soap greases. As to the quantity of oxidized asphalt to be employed in the various greases, the invention is by no means limited to the given in the example, although this has been found to be a very desirable proportion. Greases may be prepared which contain more or less asphalt, for example as high as or and as low as 10% or even 2%. Probably in general, for commercial uses, practical limits would be between about 10% and 20%. Of course in the cases of liquid or semi-liquid greases and in the more fluid oils above mentioned, the asphalt percentages would necessarily run correspondingly lower.

It is therefore to be understood that the disclosures here made are to be considered as illustrative and not as limiting except as required by the state of the prior art.

I claim:

1. A grease comprising a major proportion of mineral oil thickened with a calcium soap in amount suflicient to impartcup grease consistency, and between about 10% and 25% of an air blown asphalt having a melting point according to the A. S. T. M. ball and ring method between about F. and about F. and a penetration at 77 F. of 30 to 40 according to the A. S. T. M. method.

2. A cup grease comprising a major proportion of mineral oil thickened to cup grease consistency with a water-insoluble soap imparting water resistant characteristics to the grease, and between about 10% and 25% of air blown asphalt having a melting point according to the A. S. T. M. ball and ring method between about 140 F. and about 155 F. and a penetration at 77 F. of 30 to 40 according to the A. S. T. M. method.

3. A grease comprising in excess of about 58% of mineral oil thickened with at least about 11% of calcium soap and containing approximately 15% of air blown asphalt having a melting point according to the A. S. T. M. ball and ring method between about 140 F. and 155 F. and a penetration at 77 F. of'30 to 40 according to the A, S, T. M. method.

4. A grease comprising a major proportion of mineral oil thickened to cup grease consistency with a water-insoluble soap imparting water resistant characteristics to the grease, and between about 10% and 25% of a normally solid air blown asphalt.

5. A grease comprising a major proportion of mineral oil thickened with a calcium soap in amount suflicient to impart cup grease consistency, and between about 10% and 25% of an air blown asphalt 'solid under normal conditions.

LESTER W. McLENNAN.