Aqueous concentrated cooling lubricant for the mechanical working of aluminum and process
AssigneeBerol Suisse S.A.
InventorsElina Sandberg, Rolf Skold
Life of this patent
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Abstract
Aqueous concentrated cooling lubricants are provided in the form of a stable solution ready to use after dilution with water in processes for the mechanical working of aluminum and aluminum alloys, and containing as lubricating and corrosion inhibiting agents a combination of (a) a carboxylic acid R.sub.1 COOH, R.sub.1 having from about seven to about twenty-two carbon atoms, (b) a tertiary alkylalkanolamine having a molecular weight of less than 300 and (c) a water-soluble organic solubilizer having a molecular weight of less than 400, and a hydrocarbon group of at most 6 carbon atoms, the amounts of the carboxylic acid and the alkanolamine being selected to provide a base/acid equivalent ratio of less than 0.9.
Claims20
An aqueous stable cooling lubricant solution that does not separate into two phases at a temperature within the range from 20 to 70.degree. C., over a period of at least one month for use in the mechanical working of aluminum and aluminum alloys, that gives satisfactory lubrication and low corrosion without unacceptable staining of the aluminum surface during subsequent heat treatment, and consisting essentially of
- (a) a carboxylic acid having the formula R.sub.1 COOH, in which R.sub.1 is a hydrophobic group having from about seven to about sixteen carbon atoms selected from the group consisting of aliphatic hydrocarbon and aliphatic hydrocarbon including a group selected from ether, thioether, ester, hydroxyl, carboxyl, and amide and
- (b) a tertiary alkylalkanolamine having a molecular weight of less than 300 and the formula ##STR5## in which:
- R.sub.2 is selected from the group consisting of alkanol having from one to about four carbon atoms and at least one hydroxyl group up to about three hydroxyl groups;
- and (A) n H, wherein A is an oxyalkylene group having from two to about four carbon atoms;
- n is a number (which can be an average number) from 1 to 3;
- R.sub.3 is an alkyl group having from one to about six carbon atoms;
- and
- R.sub.4 is selected from the group consisting of R.sub.2 and R.sub.3 ;
- and
- (c) a water-soluble aliphatic alcohol, ether or mixed alcohol ether having a molecular weight of less than 400 and a hydrocarbon group having from one to about six carbon atoms, in an amount to form a stable aqueous solution of (a), (b) and (c);
- the carboxylic acid and tertiary alkylalkanolamine being in amounts selected to give a base/acid equivalent ratio of less than 1 and a pH of less than 9, on the acid side of the isoelectric point;
- and
- (d) water;
- the carboxylic acid (a), the tertiary alkyl alkanolamine (b), and the water soluble aliphatic alcohol, ether or mixed alcohol-ether (c) and their amounts being so selected as to give a stable aqueous solution when water is present in a selected working concentration of water within the range from about 25 to about 99.4%.
Dependencies are inferred from the claim text.