Aqueous silane systems for bare corrosion protection and corrosion protection of metals
The present invention relates to a furnace ( 12 ) for melting heated glass using burners ( 13 ), wherein the combustion energy is at least partially produced by oxy-fuel combustion, and wherein at least a portion of the oxygen used in the burners ( 13 ) is produced by separation, on a ceramic separation membrane ( 18 ), from a gaseous mixture including oxygen, the oxygen from the separation being directly channeled into at least one burner ( 13 ).
1. A process for producing an aqueous composition, the process comprising:
(i) hydrolyzing and condensing at least one aminoalkylalkoxysilane selected from the group consisting of a monoaminoalkylalkoxysilane, a bisaminoalkylalkoxysilane and a trisaminoalkylalkoxysilane, and optionally at least one alkoxysilane selected from the group consisting of a fluoroalkylalkoxysilane, an alkylalkoxysilane and a tetraalkoxysilane, within a reaction mixture, in the presence of at least one catalyst and water and optionally at least one solvent/diluent; then
(ii) at least partially removing from the reaction mixture the solvent/diluent and a hydrolysis alcohol, which is formed during the hydrolyzing and condensing (i);
(iii) optionally adding additional water or an aqueous acid to the reaction mixture, such that the pH of the reaction mixture is adjusted to a value in the range from 2 to less than 7; and subsequently
(iv) adding a metal salt selected from the group consisting of an acetate salt or a nitrate salt of aluminum, chromium in oxidation state 3+, and cerium in oxidation state 3+ or 4+.
2. The process of claim 1 , wherein the metal salt is at least one of a nitrate salt of Cr 3+ and an acetate salt of Cr 3+ .
3. The process of claim 1 , wherein a concentration of the metal salt is from 0.01% to 6% by weight, based on the aqueous composition.
4. An aqueous composition obtained by the process of claim 1 .
5. A process for treating a substrate surface, the process comprising contacting the substrate surface with the aqueous composition of claim 4 .
6. The process of claim 5 , wherein the substrate surface is a metal surface and the treated metal surface is protected against corrosion.
7. A corrosion control coating, obtained according to the process of claim 5 .
8. The corrosion control coating of claim 7 , further comprising a foundation layer of a powder paint or a liquid paint.
9. An article, comprising a coating obtained by treatment with the aqueous composition of claim 4 .
10. The process of claim 1 , wherein the metal salt is a Cr 3+ nitrate or acetate or a mixture of metal nitrates and acetates comprising Cr 3+ .
11. The process of claim 1 , wherein the metal acetate or nitrate is comprises a mixture of metal components selected from the group consisting of
a mixture of Cr 3+ and Al 3+ ,
a mixture of Cr 3+ and Ce 3+ ,
a mixture of Cr 3+ and Ce 4+ ,
a mixture of Cr 3+ , Ce 3+ and Ce 4+ ,
a mixture of Cr 3+ , Al 3+ and Ce 3+ and
a mixture of Cr 3+ , Al 3+ , Ce 4+ and Ce 3+ salts.
12. The corrosion control coating of claim 7 , wherein the coated substrate comprises aluminum.