US2015867A - New process for lubricating - Google Patents

Description

I Patented Oct. 1, 1935 UNITED STATES PATENT OFFICE No Drawing. Application October 14, 1933, Serial No. 693,680. In Germany February 7, 1931 I 4 Claims. The lubrication of certain parts of valves, stopcocks, compressors, welding burners, bearing parts and the like with oils, fats, or similar organic substances which may be brought into 5 contact with oxygen under pressure, is not permissible on account of the danger of explosion. Since lubrication cannot be effected under, these conditions, one must avoid wear caused by friction between the metal parts, which when worn at all are no longer capable of effecting a gastight joint and make it necessary at times to replace many parts which have been in, use for a relatively short period.

To avoid these difliculties certain lubricants of another nature than that of the above mentioned substances have been recommended e. g. highly concentrated aqueous solutions of inorganic salts which cannot be oxidized. These, however, have the disadvantage that they give ofi the water, the salt separates out, and the lubricating action thereby falls off. Moreover, such lubricants cause corrosion.

A process has been triedfor making a new and useful product which consists in subjecting glycerine to temperatures of 250-260 C. in presence of a condensing agent while a stream of an inert gas is led through the reaction mixture; According tothis process a new and useful product is obtained: a mixture of highly polymerized'glycerines being free from diand tripolymerized products, showing a brown-yellow colour, being transparent, soluble in water and alcohol, insoluble in ether, having a flash point of more than 270 C. and a refractive index of 35 about 1,5. Preferably heating is continued until the product is highly viscous.

According to the present invention it has been paste by search apparatus these lubricants, heated to over 200 'C., are stable when subjected to sudden conglycerines.

found that such products may be used advantageously for the purpose of lubrication.

As these products are sometimes too viscous for the purpose of lubrication they are mixed with about -30% water; in order to avoid evaporation, of the water, hygroscopic products (e. g. magnesium chloride, salts of lactic acid) are added in an amount of about '1-20%, preferably 5%. The explosive-proof lubricants obtained can be brought to the consistency of suitable additions, for example tragacanth, talcum and the like.

As shown by experiments with suitable retact with oxygen having a temperature of 60 C. and under a pressure of 150 at., whereas oils and fats of animal, vegetable and mineral origin, and further graphite, glycerine and the like, under the same conditions explode at very much lower pressures and temperatures.

What I claim is: 1. A lubricant comprising a mixture of highl polymerized 'glycerines free from diand triglycerines. r

2. A lubricant according to claim 1 containing 10-30% of water.

3. A lubricant according to claim 1 containing 10-30% of water and 1-20% of a hygroscopic substance.

4. A lubricant for contacting surfaces exposed to the action of oxygen under elevated temperature and pressure comprising a mixture of highly polymerized glycerines free from diand tri- KARL NOACK.