Process for decorating an aluminum substrate with a colored design

Claim 2

A PROCESS FOR FORMING ON AN ALUMINUM OR ALUMINUM ALLOY SURFACE A COLORED DESIGN OR PATTERN WHICH COMPRISES: DEGREASING, CLEANING AND AFTER-RINSING THE SURFACE, ETCHING THE WATERRINSED URFACE WITH AN ALKALINE SOLUTION, NEUTRALIZING AND WATER WASHING THE ETCHED SURFACE, PRINTING OR COATING A MASKING AGENT ON A LIMITED AREA OF THE SURFACE, SUBJECTING THE SURFACE WHILE THE MASKING AGENT IS THEREON TO A FIRST FILM FORMING STEP, REMOVING THE MASKING AGENT FROM THE SURFACE, AND SUBJECTING THE SURFACE TO A SECOND FILM FORMING STEP, WHEREBY THE SECOND FILM COVERS AREAS OF THE SURFACE SUBJECTED TO THE FIRST FILM FORMING STEP AND AREAS OF THE SURFACE COVERED BY THE MASKING AGENT.

Claim 3

A process for forming on an aluminum or aluminum alloy surface a colored design or pattern which comprises degreasing, cleaning and water-rinsing the surface, etching the water-rinsed surface with an alkaline solution, neutralizing and water-washing the etched surface, printing or coating a masking agent on the surface, subjecting the surface to a first film forming step, removing the printed masking agent, immersing the surface at least 5 minutes in a transparent coating composition comprising 20-50% of one or more of water-soluble thermosetting resins selected from the group consisting of acrylic, alkyd, melamine, phenolic, urea and aminoalkyd resins and 0.1-10% of one or more of organic amines selected from the group consisting of dimethyl ethanol amine, monoethanol amine, triethanol amine, mono-normalpropyl amine, tetraethylene pentamine and ehtylene diamine and heated at 40*-90* C and allowing the thus coated surface to set, dry and harden at 150*-200* C over a period of 15-30 minutes.

Claim 4

A process for forming on an aluminum or aluminum alloy surface a colored design or pattern which comprises degreasing, cleaning and water-rinsing the surface, etching the water-rinsed surface with an alkaline solution, neutralizing and water-washing the etched surface, printing or coating a masking agent on the surface, subjecting the surface to a first film forming step, removing the printed masking agent, immersing the surface at least 5 minutes in a transparent coating composition comprising 20-50% of one or more of water-soluble thermosetting resins selected from the group consisting of acrylic, alkyd, melamine, phenolic, urea and aminoalkyd resins and 0.1-10% of one or more of organic amines selected from the group consisting of dimethyl ethanol amine, monoethanol amine, triethanol amine, mono-normalpropyl amine, tetraethylene pentamine and ehtylene diamine and heated at 40*-90* C and allowing the thus coated surface to set, dry and harden at 150*-200* C over a period of 15-30 minutes.

Claim 5

A process as claimed in claim 1 wherein the first film forming step comprises subjecting the surface to a treatment effecting a chemical conversion thereof.

Claim 6

A process as claimed in claim 3 wherein, in the first film forming step, the surface is subjected to anodizing whereby a barrier film is formed on the surface.

Claim 7

A process as claimed in claim 3 wherein, in the first film forming step, the surface is subjected to immersion in boiling water whereby a boehmite film is formed on the surface.

Claim 8

A process as claimed in claim 3 wherein said surface is subjected to a treatment that applies a chemical conversion coating on the surface.

Claim 9

A process as claimed in claim 1 including subjecting the surface, after coating the masking agent thereon to a chemical conversion film forming step, removing the coated masking agent, immersing the surface for at least five minutes in a transparent coating composition containing 20 to 50% of water-soluble thermosetting resin selected from the group consisting of acrylic, alkyd, melamine, phenolic, urea, aminoalkyd resins and mixtures thereof and 0.1 to 10% of organic amine selected from the group consisting of dimenthyl ethanol amine, monoethanol amine, triethanol amine, mono-normal-propyl amine, tetraethylene pentamine, ethylene diamine, and mixtures thereof and heated at 40* to 90* C and allowing the thus coated surface to set, dry and harden at 150* to 200* C over a period of 15 to 30 minutes.

Claim 10

A process for forming on an aluminum or aluminum alloy surface a colored design or pattern which comprises: degreasing, cleaning and water-rinsing the surface, etching the water-rinsed surface with an alkaline solution, neutralizing and water-rinsing the etched surface, printing or coating a masking agent on a limited area of the surface, subjecting the surface while the masking agent is thereon to a first film forming step by immersion for at least five minutes in an aqueous solution containing 0.1 - 10% of one or more of organic amines selected from the group consisting of dimethyl ethanol amine, monoethanol amine, triethanol amine, mono-normal-propyl amine, tetraethylene pentamine and ethylene diamine heated to a temperature of 40* -90* C, removing the masking agent from said limited area of the surface, and subjecting the surface to a second film forming step.

Claim 11

A process for forming on an aluminum or aluminum alloy surface a colored design or pattern which comprises: degreasing, cleaning and water-rinsing the surface, etching the water-rinsed surface with an alkaline solution, neutralizing and water-rinsing the etched surface, printing or coating a masking agent on a limited area of the surface, subjecting the surface while the masking agent is thereon to a first film forming step by immersion for at least five minutes in an aqueous solution containing 0.1 - 10% of one or more of organic amines selected from the group consisting of dimethyl ethanol amine, monoethanol amine, triethanol amine, mono-normal-propyl amine, tetraethylene pentamine and ethylene diamine heated to a temperature of 40* -90* C, removing the masking agent from said limited area of the surface, and subjecting the surface to a second film forming step.