DE645939C - Brake or pressure fluids - Google Patents

Description

Brake or pressure fluids To generate hydraulic pressure, as required, for example, to operate brakes or pressure rams various liquids have been proposed, one of which is fat Oils, in particular castor oil, mineral oils, glycerine alone or as a mixture with other substances, such as ethyl, butyl or amyl alcohol, which are the most common. However, all of these commercial products have disadvantages in that they either at elevated temperatures, such as those in the automobile engine and especially during use occur frequently in the tropics, are too volatile or at low temperatures are difficult to move due to too high toughness or the necessary sliding ability dispense at all, so that it is not possible in a branched system, As is the case with automobile brakes, for example, one at all points to generate even pressure. Still other liquids leave the necessary resistance especially since miss at elevated temperatures and then tend to be chemically aggressive to work by, for example, rubber, leather, plastics or metals, in particular Copper, attack and cause destruction.

It has now been found,: that the cyclic ethers, which at least Contains 2 oxygen atoms in the ring and also substituted by hydroxyl groups are excellent as brake and pressure fluids. The products of the claimed Type can be easily removed by condensation of carbonyl compounds such as formaldehyde, Acetaldehyde, acetone, benzaldehyde, furfural, camphor, cyclohexanone, methylcyclohexanone, Decahydro-ß-naphthyl ketone, etc., with polyhydric, aliphatic alcohols such as glycerine, Erythritol, arabitol, dulcitol, mannitol and the like win. By esterification or etherification the cyclic ethers still containing free hydroxyl groups are as desired Brake or pressure fluids with lower or higher viscosity can be produced. As particularly suitable for use as a brake and pressure fluid or for the preparation of such liquids have, for example, 2,2-dimethyl-q.-oxymethyldihydrodioxole (Acetone glycerine), acetone glycerine butyl ether, acetone arabitol, mannitol triformal, diacetonerythritol, Benzylidene glycerine and the 2,2-pentamethylene-q.-oxymethyldihydrodioxole obtainable from cyclohexanone and glycerine (Cyclohexanone glycerine) and the cyclohexanone glycerine phthalate.

The claimed products are characterized by a neutral reaction, high temperature resistance, good blending ability with other known means and good sliding properties at all possible temperatures. she can be used both individually and in combination with one another as well as together with other known, for the same Verdüngszwecken-already proposed means to be needed.

Suitable brake fluids are, for example, mixtures of 8o weight steles of castor oil and 50 weight parts of cyclohexanone glycerine or 50 weight parts Glycerin and 50 parts by weight of diacetonerythritol called.

Liquids suitable for pressure stamps can, for example, consist of The following mixtures exist: for one part glycerine and 35 parts acetone mannitol or 45 parts of acetone glycerol cetyl ether and 55 parts of castor oil or 3o parts of ethylene glycol monoethyl ether and; o parts of cyclopentanone glycerol phthalate.

Claims (3)

PATENT CLAIMS: i. Brake or pressure fluids, consisting of cyclic ethers, which at least Contains 2 oxygen atoms in the ring and also are still hydroxyl-substituted. z. Brake or pressure fluid, consisting of ethers or esters of the hydroxyl-substituted cyclic ethers protected in claim i. 3. Brake or pressure fluid, consisting of those protected in claims i and 2 cyclic ethers mixed with one another or with other known ones in the same way Wise acting means.