US1945543A - Hydraulic fluid - Google Patents

Description

Patented Feb. 6, 1934 1,945,543 v HYDRAULIC FLUID Arthur G. Weber and Richard B. Schneider, Wilmington, Del., assignors to E. I. du Pont do Nemours & Company, poration of Delaware Wilmington, l )el., a cor- No Drawing. Application March 29, 1932 Serial No. so1,ss1

14 Claims.

This invention relates to compositions of matter and more particularly to fluids especially desirable for use in hydraulically operated apparatus, such, for example, as hydraulic brake sys- 5 tems, hydraulic jacks, door checks, and shock absorbers, and the like. It has been previously proposed to use solutions of ethyl alcohol and castor oil, and the like, for actuating the pressure-operated elements of hydraulic brake systems and similarly operated apparatus. Up to the present time, however, the different solutions and mixtures proposed for these purposes have been characterized by numerous disadvantages, such, for example, as asiflcation, giving rise to highly dangerous possibilities in connection with braking systems. Another undesirable characteristic has been the tendency toward solidification of such a mixture at the lower temperatures, making dangerous and at times impossible the utilization of saidpreviously proposed liquids in localities such as are subject to low temperatures. Accompanying these disadvantageous features there has existed an undesirably wide change in viscosity of previously suggested hydraulic fluids under varying temperatures. I

We have discovered, however, that a highly desirable fluid for use in hydraulically operated systems such as hydraulic brake systems, hydraulic aojacks, door checks, shock absorbers or the, like,

free from the disadvantages above outlined, is obtained by mixing with varying proportions of an oil the product obtained as a by-product in the catalytic hydrogenation of the oxides of carbon to methanol. These by-products comprise, for the most part, mixtures of alcohols of high molecular weight together with small amounts of other unidentified organic compounds containing oxygen.

40- Other oils may be used instead of castor oil altho we have found it to possess those characmixture of such higher molecular weight alcohols is suitable for use, in admixture with castoroil or the like, for hydraulically operated systems,

m we have found that certain fractions of said complete lay-product are preferable, especially that fraction boiling between the range of from 133 C. to 250 C'.-

Compared with hydraulic fluids hitherto suggested the mixtures prepared according to our in- 6h vention possess highly improved characteristics for utilization in hydraulic apparatus generally. Thus, for example, the viscosity of the fluid of our invention is highly uniform throughout a wide temperature range. Furthermore, our fluid has considerably less expansion than those previously used, does not precipitate under low temperatures, and in addition to the castor oil or the like the mixture of higher molecular weight alcohols contained therein has of itself a desirable lubricating value. Moreover, our fluid is free from the objectionable gasiflcation phenomena found in other fluids, and exerts no disadvantageous corrosive action upon the metallic parts with which it, comes in contact.

Although the invention is in no way limited thereby and the proportions of constituents may be varied over a wide range, below are given certain specific fractions, of indicated boiling point range, of the by-product obtained in the catalytic hydrogenation of the oxides of carbon to methanol, together with the specific proportions in which they, mixed with castor oil, blown rape seed oil and liquid petrolatum, may be utilized for a desirable hydraulic fluid possessing the requisite viscosity characteristics at the extremes of the temperature encountered in hydraulically operated apparatus.

Although the invention will be understood as I not limited thereto below are also indicated specific uses to which hydraulic fluids of our invention may be put.

Hydraulic brake fluid Parts by weight l y paoguct gbg lgz o olbllyE 9 Y 08 alytic hydrogenaa- 6 P not fraction tion of oxides of I carbon I g 5 g; 5 C. and above. as 15' v boo-1W0, v g? }l64-169 0. m5 50 50 147-151" 0.

t z? 93, 7 lac-154 0. 95 5 Shock absorber fluid Blown rape seed 011 41.6 68.5 195 C.and above. 31.5 68.5 157-195 C.

Castor oil 94. 6 5. 5 195 0. and above.

Door check fluid 62 38 160 C. and above Hydraulic :iaclc fluid I Liquid j petrolatum 25 160 C. and above Various changes may be made in the method described without departing from the invention or sacrificing any of the advantages thereof.

We claim:

1. A fluid for use in fluid pressure apparatus comprising an oil characterized by low solidifying point, and stability at high temperature, and a mixture of higher boiling oxygenated organic liquid products obtainable as a by-product in the catalytic hydrogenation of oxides of carbon to methanol.

2. A fluid for use in fluid pressure apparatus comprising on oil characterized by low solidifying point, stability at high temperatures, and a mixture of higher boiling oxygenated organic liquid products boiling above 133 C. obtainable as a by-product by the catalytic hydrogenation of oxides of carbon to methanol.

3. A fluid for use in fluid pressure apparatus comprising an oil characterized by low solidifying point, stability at high temperatures, and a mixture of the higher boiling oxygenated organic liquid products obtainable as a by-product in the catalytic hydrogenation of oxides of carbon to methanol, in the proportions of from 5-195 parts of said product to 95-5 parts of said o1 4. A fluid for use in fluid pressure apparatus comprising an oil characterized by low solidifying point, stability at high temperatures, and a mixtureof the higher boiling oxygenated organic liquid products boiling above 133 C. obtainable as a by-product by the catalytic hydrogenation of oxides of carbon to methanol, in the proportions of from 5-95 parts of said products to from 95-5 parts of said oil.

5. A fluid for use in fluid pressure apparatus comprising an oil characterized by low solidifying point, stability at high temperatures, and a mixture of the higher boiling oxygenated organic liquid products boiling from 133 C. to 250 C. obtainable as a by-product by the catalytic hydrogenation of oxides of carbon to methanol, and consisting principally of a mixture of alcohols of high molecular weight in the proportion of 5-95 parts of said product to 95-5 parts'of said 011.!

6. A fluid for use in fluid pressure apparatus comprising castor oil and a mixture of higher boiling oxygenated organic liquid products obtainable as a by-product in the catalytic hydrogenation of oxides of carbon to methanol.

7. A fluid for use in fluid pressure apparatus comprising castor oil and a mixture of higher boiling oxygenated organic liquid products boiling above 133 C. obtainable as a by-product by the catalytic hydrogenation of oxides of carbon to methanol and consisting principally of a mixture of alcohols of high molecular weight, in the proportions of from 5-95 parts of said products to from 95-5 parts of castor oil.

8. A fluid for use in fluid pressure apparatus comprising castor oil and a mixture of the higher boiling oxygenated organic liquid products boiling from 147 C. to 157 C. obtainable as a. byproduct by the catalytic hydrogenation of oxides of carbon .to methanol and consisting principally of a mixture of alcohols of high molecular weight, in the proportion of 50 parts of said product to 50 parts of castor oil.

9. A fluid for use in fluid pressure apparatus comprising rape seed oil and a mixture of higher boiling oxygenated organic liquid products obtainable as a by-product in the catalytic hydrogenation of oxides of carbon to methanol.

10. A fluid for use in fluid pressure apparatus I comprising rape seed oil and a mixture of higher proportions of from 5-95 parts of said products to from-95-5 parts of rape seed oil.

11. A fluid for use in fluid pressure apparatus comprising rape seed oil and a mixture of the higher boiling oxygenated organic liquid products boiling from 157 C. to 195 C. obtainable as a by-product by the catalytic hydrogenation of oxides of carbon to methanol and consisting principally of a mixture of alcohols of high molecular weight, in the proportion of 31.5 parts of said product to 68.5 parts of rape seed oil.

12. A fluid for use in fluid pressure apparatus comprising liquid petrolatum and a mixture of higher boiling oxygenated organic liquid products obtainable as a by-product in the catalytic hydrogenation of oxides of carbon to methanol.

13. A fluid for use in fluid pressure apparatus comprising liquid petrolatum and a mixture of higher boiling oxygenatedo'rganic liquid products boiling above 133 C. obtainable as a byproduct by the catalytic hydrogenation of oxides of carbon to methanol and consisting principally of a mixture of alcohols of high molecular weight, in the proportions of from 5-95 parts of said products to from 95-5 parts of liquid petrolatum.

14. A fluid for use in fluid pressure apparatus comprising liquid petrolatum and a mixture of the higher boiling oxygenated organic liquid products boiling from C. to 250 C. obtainable as a by-product by the catalytic hydrogenation of oxides of carbon to methanol and consisting principally of a mixture of alcohols of high molecular weight, in the proportion of 25 parts of said