DE1230159B - Hydraulic fluids - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

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German class: 23 c-5

1 230159
J22228IVc / 23c
November 6, 1959
December 8, 1966

The use of mono- or diricinoleates of aliphatic glycols or of polyethylene ricinoleates and of reaction products of low molecular weight alkylene oxides with castor oil as components of hydraulic fluids is already known. However, these hydraulic fluids have the disadvantage that their viscosity changes greatly with changes in temperature.

Hydraulic fluids based on at least one alcohol, polyalcohols, ίο such as glycol or polyglycols, ether alcohols, keto alcohols and esters and ethers of these compounds as solvents do not have these disadvantages if they are used according to the invention. Polyoxyalkylene glycol esters of castor oil, treated at 100 to 200 ⁰ C, if appropriate in the presence of a phenol, alkyl phenol or aminophenol with oxygen or air, are added.

The starting materials do not need to be specially cleaned, but can also be removed from commercial products that contain impurities. However, the use of impure results The starting material is sometimes too strongly colored and therefore difficult to sell in the trade. This The disadvantage is eliminated in that the reaction is carried out in the presence of an antioxidant thereby reducing the coloration.

Phenols, in particular trialkylphenols, such as 2,4,6-trialkylphenols, especially 2,4-dimethyl-6-cyclohexylphenol and 2-tert-butyl-4-methyl-6-cyclohexylphenol, or aminophenols. These connections are used in very low concentrations, e.g. in the order of 0.1 to 0.001% added.

A finely divided stream of air or gas which contains oxygen is introduced into the starting materials, if appropriate in the presence of antioxidants. The temperature should be between 100 and 200 ^° C. and the reaction time between several hours and 200 hours. The products thus obtained are generally too viscous to be used directly as hydraulic fluids; it is preferable in most cases to mix them with a solvent. The following solvents are preferably used: alcohols, polyalcohols, such as glycols and polyglycols, ether alcohols, keto alcohols and esters and ethers of these compounds.

The proportion of polymerized polyoxyalkylene ester of castor oil in the hydraulic fluid depends on the degree of conversion, the solvent used and the desired properties. at the higher the ester content, the higher the viscosity and the hydraulic choke.

Applicant:

Institut Francais du Petrole,

des Carburants et Lubrifiants,

Rueil-Malmaison, Seine-et-Oise (France)

Representative:

Dr. F. Zumstein, Dr. E. Assmann

and Dr. R. Koenigsberger, patent attorneys,

Munich 2, Bräuhausstr. 4th

Named as inventor:

Jean Larbre, Colombes, Seine;

Pierre Quaire, Caen, Seine (France)

Claimed priority:

France of November 6, 1958 (778 462) - -

the freezing point. On the other hand, the higher the viscosity and the higher the freezing point lower, the greater the degree of implementation. For extracting a hydraulic fluid with a very deep The freezing point is therefore, for example, a dilute polyoxyalkylene ester solution with a high degree of conversion use while maintaining sufficient viscosity. A content of 5 to 50% of polymerization product is sufficient for most cases.

The manufacture of the products used as components for hydraulic fluids is not claimed.

example

Bis-ricinoleic acid esters of polyoxyethylene glycol with a molecular weight of 400 and 2-tert-butyl-4-methyl-cyclohexylphenol in a ratio of 1 part by weight: 1/10 000 parts by weight are placed in a steel apparatus lined with glass, whereupon this mixture is carried out for 80 hours long, an air stream is passed at a temperature of 15O ⁰ C.

In the table below are the properties of the product obtained according to the previous example compared with those of a product not treated with air.

609 730/362

Tabel

properties Prodi
A. lked B. viscosity at 37.8 ° C 17.5 6.8 at 50 ⁰ C 12.5 4.95 at 98.9 ° C .-: .... . - 4.7 2.05 Viscosity number ... 194 105 Cloud point .... -30 ° C -30 ⁰ C Freezing point .. -60 ⁰ C -50 ⁰ C

35% solution of the according to the invention Example of product obtained in ethyl diglycol;

35% solution of the same, not with air treated product in ethyl diglycol.

Claims (1)

Claim: Using Polyoxyalkylenglykolestem of castor oil, treated at 100 to 200 ⁰ C, if appropriate in the presence of a phenol, alkyl phenol or aminophenol with Sauerstoif or air as a component of hydraulic fluids based on at least an alcohol, polyalcohols such as glycol or polyglycols, ether alcohols, Keto alcohols and esters and ethers of their compounds as solvents. Considered publications: German Patent Nos. 850 053, 960 921;
German interpretative document No. 1 031 921. 609 730/362 11.66 © Bundesdruckerei Berlin