Abstract In the process for treating the surface of aluminum or an aluminum alloy which comprises subjecting said surface to an anodic oxidation and subsequently sealing with hot water or steam, the improvement which consists essentially of sealing said surface by applying an aqueous solution containing calcium ions and from 0.001 to 0.05 gm per liter of at least one acid selected from the group consisting of (A) a water-soluble phosphonic acid which forms a complex with a divalent metal, (B) a water soluble salt of said acid of (A), and (C) the mixtures thereof at a temperature ranging from 90*C to the solution boiling point temperature and at a pH of from 5 to 6.5, to the anodic oxidized surface, the molar ratio of calcium ions to phosphonic acid being at least 2:1.
IN THE PROCESS FOR TREATING THE SURFACE OF ALUMINUM OR AN ALUMINUM ALLOY WHICH COMPRISES SUBJECTING SAID SURFACE TO AN ANODIC OXIDATION AND SUBSEQUENTLY SEALING WITH HOT WATER OR STEAM, THE IMPROVEMENT WHICH CONSISTS ESSENTIALLY OF SEALING SAID SURFACE BY APPLYING AN AQUEOUS SOLUTION CONSISTING ESSENTIALLY OF WATER, CALCIUM IONS AND FROM 0.001 TO 0.05 GM PER LITER OF AT LEAST ONE ACID SELECTED FROM THE GROUP CONSISTING OF (A) A WATER-SOLUBLE PHOSPHONIC ACID WHICH FORMS A COMPLEX WITH A DIVALENT METAL, SAID ACID HAVING THE FORMULA
Claim 2
Dependent Claim
87 words
IN THE PROCESS FOR TREATING THE SURFACE OF ALUMINUM OR AN ALUMINUM ALLOY WHICH COMPRISES SUBJECTING SAID SURFACE TO AN ANODIC OXIDATION AND SUBSEQUENTLY SEALING WITH HOT WATER OR STEAM, THE IMPROVEMENT WHICH CONSISTS ESSENTIALLY OF SEALING SAID SURFACE BY APPLYING AN AQUEOUS SOLUTION CONSISTING ESSENTIALLY OF WATER, CALCIUM IONS AND FROM 0.001 TO 0.05 GM PER LITER OF AT LEAST ONE ACID SELECTED FROM THE GROUP CONSISTING OF (A) A WATER-SOLUBLE PHOSPHONIC ACID WHICH FORMS A COMPLEX WITH A DIVALENT METAL, SAID ACID HAVING THE FORMULA
Claim 3
Dependent Claim
22 words
The process as claimed in claim 1 in which the ratio of calcium ions to phosphonic acid is from 5:1 to 500:1.
Claim 4
Dependent Claim
29 words
THE PROCESS AS CLAIMED IN CLAIM 1 IN WHICH SAID SALT OF (B) IS SELECTED FROM THE GROUP CONSISTING OF ALKALI METAL SALTS, AMMONIUM SALTS, AND LOWER ALKANOLAMINE SALTS.
Claim 5
Dependent Claim
22 words
The process as claimed in claim 1 in which said solution additionally contains from 0.1 to 5 gm per liter of dextrin.
Claim 6
Dependent Claim
21 words
The process as claimed in claim 4 in which said solution contains from 0.01 to 2 gm per liter of dextrin.