Method for Obtaining a Cooking Vessel Having a Colored Hard-Anodized Outer Face

Abstract

Provided is a method for obtaining a cooking vessel comprising the following steps: producing a container having an aluminium outer face and an inner face, carrying out hard anodization of at least the outer face of the container. At least one colouring step is carried out on the anodized outer face following hard anodization, said colouring step employing at least one water-soluble anthraquinone organic dye. Also provided is a culinary article or an electric cooking appliance comprising a cooking vessel obtained by the above method.

1 . A process of obtaining a cooking vessel, consisting of the following steps:
 producing a container with an exterior surface made of aluminum and an interior surface,   performing a hard anodization on at least the exterior surface of the container to obtain a hard anodized layer, wherein at least one coloring step is performed on the anodized exterior surface after the hard anodization is performed, said coloring step uses at least one water-soluble anthraquinone organic dye, and said coloring step uses a coloring bath containing anthraquinone organic compounds which will precipitate and be trapped inside pores of the hard anodized layer to obtain coloring on the exterior anodized surface.   
     
     
         2 . The process of obtaining a cooking vessel described in  claim 1 , wherein the coloring step uses an immersion in an aqueous solution of one or more water-soluble anthraquinone organic compound(s). 
     
     
         3 . The process of obtaining a cooking vessel described in  claim 1 , including a step in which a PTFE coating is applied to the interior surface of the container, and wherein the step in which hard anodization is performed on the exterior surface of the container occurs after the step in which a PTFE coating is applied to the interior surface of the container. 
     
     
         4 . The process of obtaining a cooking vessel described in  claim 3 , including a step in which preliminary hard anodization is performed on the exterior surface and on the interior surface of the container prior to the step in which the PTFE coating is applied to the interior surface of the container, and wherein the step in which hard anodization is performed on the exterior surface of the container occurs after an etching step on the exterior surface of the container, following the PTFE coating step on the interior surface of the container. 
     
     
         5 . The process of obtaining a cooking vessel described in  claim 1 , wherein the hard anodization step and the coloring step are performed on the interior surface and the exterior surface of the container. 
     
     
         6 . The process of obtaining a cooking vessel described in  claim 1 , wherein the hard anodization is performed at a temperature of greater than or equal to 0° C. 
     
     
         7 . The process of obtaining a cooking vessel described in  claim 6 , wherein the hard anodization is performed at a temperature of less than or equal to 17° C. 
     
     
         8 . The process of obtaining a cooking vessel described in  claim 1 , wherein the hard anodization is performed at a temperature of between 5° C. and 12° C. 
     
     
         9 . A cooking vessel comprising a container with an exterior surface made of aluminium and an interior surface, wherein at least the exterior surface is anodized, wherein the exterior surface is hard anodized to obtain a hard anodized layer and the hard anodized exterior surface is colored with at least one water-soluble anthraquinone organic dye, using anthraquinone organic compounds trapped inside pores of the hard anodized layer, to obtain coloring on the anodized external surface. 
     
     
         10 . The cooking vessel according to  claim 9 , wherein the anodized layer is at least equal to 25 μm in thickness. 
     
     
         11 . The cooking vessel described in  claim 10 , wherein the container is obtained by stamping a substrate with at least one surface made of aluminum. 
     
     
         12 . The cooking vessel described in  claim 11 , wherein the substrate has two aluminum surfaces. 
     
     
         13 . The cooking vessel described  claim 11 , wherein the substrate is made of solid aluminum. 
     
     
         14 . The cooking vessel described in  claim 11 , wherein the substrate is formed by a laminate with one aluminum surface and one stainless steel surface. 
     
     
         15 . The cooking vessel described in  claim 10 , wherein the container is made of cast aluminum. 
     
     
         16 . The cooking vessel described in  claim 10 , wherein the exterior surface of the container has one of a brushed or microbead-blasted surface. 
     
     
         17 . The cooking vessel described in  claim 10 , wherein the container has at least one insert made of ferromagnetic material. 
     
     
         18 . Culinary item consisting of a cooking vessel and a handling instrument attached to said cooking vessel by at least one rivet or by welding, wherein said cooking vessel conforms to  claim 10 . 
     
     
         19 . Electric cooking appliance, consisting of a cooking vessel combined with a heat source, wherein said cooking vessel conforms to  claim 10 .