Compositions – Electrolytes for electrical devices
Patent
1994-05-26
1995-11-21
Howard, Jacqueline V.
Compositions
Electrolytes for electrical devices
252 79, C10M12976
Patent
active
054684056
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
This invention relates to the use of partly dehydrated castor oils as lubricants.
STATEMENT OF RELATED ART
It has long been known that synthetic ester oils can be used both as a base oil and also as an additive to lubricants. By comparison with the less expensive, but ecologically less sale mineral oils, synthetic ester oils are generally used as a base oil when better viscosity/temperature behavior and a lower pour point are required. Thus, in civil and military aviation for example, turbine oils based on synthetic ester oils of adipic acid, azelaic acid and/or sebacic acid with alkanols have long played a significant role (see Ullmann's Enzyclopadie der technischen Chemie [Title in English: Ulmann's Encyclopedia of Technological Chemistry], Vol. 20, pages 457-671, 1984). However, not only synthetic ester oils, but also natural esters, such as technical castor oil with hydroxyl values of 160 to 170 mg KOH/g, have already been used as a base oil for high-performance engines, such as racing engines, by virtue of their extremely good lubricating properties. However, with continual increases in engine performance, lubricants and, more particularly, the base oils of lubricants are having to meet steadily increasing requirements. Thus, the lubricants are not only supposed to reduce wear, for example of metal parts, they are also supposed to enable the metal parts to be exposed to higher pressures without seizing. However, this particular property, which is also known as the extreme-pressure property, is hardly pronounced in the case of technical castor oil.
DESCRIPTION OF THE INVENTION
Object of the Invention
For reasons of cost, however, synthetic and even natural esters are not only used as a base oil, but often as an additive to minimize wear (anti-wear) or the risk of seizing (extreme pressure). In cases such as these, only small quantities of ester are added to known lubricants, such as mineral oils. Although the synthetic or natural esters known from the prior art have good lubricating properties which reduce wear, there is still a considerable demand for new esters which minimize seizing more effectively than known esters. In addition, the esters should be of natural origin and should be readily available and biodegradable. The esters should also show excellent low-temperature behavior where they are used as a base oil.
The problem addressed by the present invention was to provide esters which would satisfy this requirement.
SUMMARY OF THE INVENTION
The present invention relates to the use of partly dehydrated castor oils with hydroxyl values of 90 to 150 mg KOH/g as lubricants.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The partly dehydrated castor oils used in accordance with the invention may be produced in known manner by dehydration of castor oil with hydroxyl values of 160 to 170 mg KOH/g in the presence of acidic catalysts, such as sulfuric acid, phosphoric acid, acid anhydrides, metal oxides showing an acidic reaction or hydrogen-containing salts showing an acidic reaction, such as sodium hydrogen sulfate, at temperatures of 200.degree. to 300.degree. C., with removal of water. Overviews on the dehydration of castor oil can be found in Farbe und Lack 57, 149 (1951) and in Fette und Seifen, No. 9, 425 (1943). For the purposes of the present invention, the partly dehydrated castor oils are preferably obtained from castor oil using phosphorous acid in accordance with GB 671,368, preferably in the presence of 0.1 to 1% by weight, and more preferably in the presence of about 0.25 to 0.75% by weight, based on castor oil, of phosphorous acid, and at temperatures in the range from 230.degree. to 260.degree. C. The required hydroxyl value of 90.degree. to 150 mg KOH/g of the partly dehydrated castor oils can be adjusted on the one hand through the quantities of phosphorous acid used and, above all, through the reaction time. In principle, it may be said that, the longer the reaction time, the lower the hydroxyl value obtained, the reaction time being reducible by addit
REFERENCES:
patent: 1782501 (1930-11-01), Clough
patent: 1892258 (1932-12-01), Ufer
patent: 2225552 (1940-12-01), Colberth
patent: 2361022 (1944-10-01), Gilbert
patent: 2371656 (1945-03-01), Smith
patent: 2484328 (1949-10-01), Agster et al.
Ullmann's Enzyclopadie der technischen Chemie, vol. 20, pp. 457-671, 1984 month unavailable.
"Fette und Seifen", No. 9, 425 (1943) Sep.
Bongardt Frank
Klein Johann
Schmid Karl-Heinz
Henkel Kommanditgesellschaft auf Aktien
Howard Jacqueline V.
Jaeschke Wayne C.
Millson Jr. Henry E.
Wisdom, Jr. Norvell E.
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