Compositions – Electrolytes for electrical devices
Patent
1989-10-10
1991-07-16
Willis, Prince E.
Compositions
Electrolytes for electrical devices
72 42, C10M12926, C10M12952
Patent
active
050323032
DESCRIPTION:
BRIEF SUMMARY
The present invention relates to a method in the processing of aluminium and the use of certain compounds as flocculants in an oil for the processing of aluminium.
In the processing of aluminium, e.g. rolling, wire drawing and cutting processes, an oil is often used, which is sprayed onto the aluminium which is processed and which oil is then collected, passed through a filter and recirculated. During the processing great amounts of small aluminium particles are formed which give the oil a dark colour. As a result of oxidation of the oil acid products are formed, which can react with the aluminium particles to form soaps. The acids and the soaps can be adsorbed to the aluminium particles with the polar parts facing the metal surface and the oil like parts facing the oil. The result of the adsorption is a sterical stabilization of the particles so that they do not settle but are kept suspended in the oil. The protective oil film around the particles also has the effect that the particles do not get caught in the filter but pass therethrough without the oil being decoloured.
The brown-coloured particle-containing oil often results in a brown staining of the foil which is prepared. Another disadvantage is that particles in the oil on milling of aluminium to a thin foil can cause perforations to be formed in the foil.
An object of the present invention is therefore to find additives to the oil, which break the sterical stabilization of the particles and enables the particles to be filtered off to give a clear colourless oil.
According to the present invention it has now been found that the above object is achieved by adding as a flocculant to the oil a compound from the group consisting of dicarboxylic acids having the general formula phenylene.
In accordance with the above the invention relates to a method in the processing of aluminium, wherein oil from a supply is sprayed onto the aluminium which is processed whereafter it is collected and passed through a filter and then back to the supply, which method is characterized in that an oil is used which contains a flocculant selected from the group consisting of dicarboxylic acids having the general formula
When A is a branched alkylene group, each branch preferably contains at most two carbon atoms Examples of such branched acids are 3-methyladipic acid and diethylmalonic acid.
Particularly preferred are such acids of the above formula wherein A is an alkylene group of 7 or 8 carbon atoms in a straight chain (azelaic acid and sebacic acid, respectively), especially the first-mentioned acid.
Examples of acids, wherein A in the above formula is phenylene, is phthalic acid.
The amount of the flooculant in the oil should be sufficient to make the user of the oil consider the additive effective. Preferably the concentration amounts to at least 50 ppm calculated on the total weight of the oil. On account of the limited solubility of the flocculant in the oil the concentration of the flocculant is suitably lower than that corresponding to the limit of the solubility of the flocculant in the oil. When the oil is supposed to be subjected to varying temperature conditions consideration should be paid to the variation of the solubility with temperature in order to prevent the separation of dicarboxylic acid from the oil.
On delivery to the consumer the oil suitably should have a high content of the flocculant, preferably about 500 ppm, the oil thus delivered being mixed at the place of use with used oil which has become impoverished of flocculant.
The basic oil of the oil used according to the invention is of a conventional type for the respective field of use, usually a naphthenic or paraffinic oil of low viscosity, and contains additives which are conventional in connection with the use, such as for instance, antioxidants and lubricity additives in conventional amounts.
An example of common antioxidants in this connection is butylated hydroxytoluene (BHT; 2,6-di-tert.butyl-p-cresole).
Usually lauryl alcohol, butyl stearate or lauric acid is used as the lubricity additi
REFERENCES:
patent: 2990943 (1961-07-01), Turnisky
patent: 3050466 (1962-08-01), Heisig
patent: 3923671 (1975-12-01), Knepp
patent: 4132662 (1979-01-01), Sturwold
patent: 4390438 (1983-06-01), Kennedy et al.
patent: 4452711 (1984-06-01), Laemmle
patent: 4800034 (1989-01-01), Akao
McAvoy Ellen M.
Nynas Industri AB
Willis Prince E.
LandOfFree
Method in the processing of aluminum and the use of certain acid does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method in the processing of aluminum and the use of certain acid, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method in the processing of aluminum and the use of certain acid will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-129607