Corrosion-stable aluminum pigments and process for the production thereof

Abstract

In aluminum-based metal pigments produced by physical vapor deposition of a metal film and subsequent crushing of the metal film metal surfaces which are exposed after the operation of crushing the metal film and in particular fracture surfaces thereof are covered with a passivting protective layer to afford corrosion stability of those metal pigments.

What is claimed is:  
     
         1 . A process for producing a corrosion-stable aluminum-based metal pigment comprising: 
 producing an aluminum or aluminum-based alloy metal film by means of physical vapor deposition (PVD) and    subsequent crushing of the metal film by ultrasound or agitator wherein the pigment obtained by the crushing operation is treated during said crushing of the metal film with at least one substance selected from the group consisting of phosphonic acids, phosphoric acids, phosphoric acid esters, organophosphites and derivatives of said substances in the absence of a nitro-containing solvent to produce a passivating protective layer on the free metal surfaces of the pigment.    
     
     
         2 . A process as set forth in  claim 1   wherein the pigment is treated with a derivative having between 8 and 20 C-atoms of said substances.    
     
     
         3 . A process as set forth in  claim 1   wherein the pigment is treated in a solution of at least one salt-like compound of said substances.    
     
     
         4 . A process as set forth in  claim 1   wherein the pigment is treated in a solution of at least one salt-like compound of said derivatives.    
     
     
         5 . A process as set forth in  claim 1   wherein the operation of applying the passivating protective layer to the free metal surfaces of the pigment particles is effected during the operation of crushing the metal film produced by PVD.    
     
     
         6 . A process as set forth in  claim 1   wherein a substance forming at least a component of the passivating protective layer forms a release layer in production of the aluminum pigment by means of PVD and wherein during the operation of crushing the metal film the release layer is detached and applied as a protective layer to the free metal surfaces of the metal particles.    
     
     
         7 . A process as set forth in  claim 1   wherein a substance forming at least a component of the passivating protective layer forms a release layer in production of the aluminum pigment by means of PVD and wherein during the operation of crushing the metal film the release layer is detached and by the addition of a suitable protective layer component reacted with same and the resulting reaction product is applied as the protective layer.    
     
     
         8 . A process as set forth in  claim 1   wherein the phosphoric acid ester is in the form of a monobasic or polybasic acid.    
     
     
         9 . A process as set forth in  claim 1   wherein the phosphoric acid esters are based on higher fatty alcohols.    
     
     
         10 . A process as set forth in  claim 1   wherein the phosphoric acid ester is triethyl phosphate.    
     
     
         11 . A process as set forth in  claim 1   wherein the phosphonic acid is 2-carboxyethane phosphonic acid.    
     
     
         12 . A process as set forth in  claim 1   wherein the organophosphate is dioctylphosphite.    
     
     
         13 . A process for producing a corrosion-stable aluminum-based metal pigment comprising: 
 producing an aluminum or aluminum based alloy metal film by means of physical vapor deposition (pvd) and    subsequent crushing of the metal film by ultrasound or agitator    wherein the pigment obtained by the crushing operation is treated during said crushing of the metal film with at least one substance selected from the group consisting of phosphonic acids, phosphoric acids, phosphoric acid esters, organophosphites and derivatives of said substances in the absence of a solvent or in the presence of a solvent selected from the group consisting of water, alcohol, ketones, alkanes, ethers, tetrahydrofuran, propylacetate, toluene or mixtures thereof to produce a passivating protective layer on the free metal surfaces of the pigment.    
     
     
         14 . A process as set forth in  claim 13   wherein the pigment is treated with a derivative having between 8 and 20 C-atoms of said substances.    
     
     
         15 . A process as set forth in  claim 13   wherein the pigment is treated in a solution of at least one salt-like compound of said substances.    
     
     
         16 . A process as set forth in  claim 13   wherein the pigment is treated in a solution of at least one salt-like compound of said derivatives.    
     
     
         17 . A process as set forth in  claim 13   wherein the operation of applying the passivating protective layer to the free metal surfaces of the pigment particles is effected during the operation of crushing the metal film produced by PVD.    
     
     
         18 . A process as set forth in  claim 13   wherein a substance forming at least a component of the passivating protective layer forms a release layer in production of the aluminum pigment by means of PVD and wherein during the operation of crushing the metal film the release layer is detached and applied as a protective layer to the free metal surfaces of the metal particles.    
     
     
         19 . A process as set forth in  claim 13   wherein a substance forming at least a component of the passivating protective layer forms a release layer in production of the aluminum pigment by means of PVD and wherein during the operation of crushing the metal film the release layer is detached and by the addition of a suitable protective layer component reacted with same and the resulting reaction product is applied as the protective layer.    
     
     
         20 . A process as set forth in  claim 13   wherein the phosphoric acid ester is in the form of a monobasic or polybasic acid.    
     
     
         21 . A process as set forth in  claim 13   wherein the phosphoric acid esters are based on higher fatty alcohols.    
     
     
         22 . A process as set forth in  claim 13   wherein the phosphoric acid ester is triethyl phosphate.    
     
     
         23 . A process as set forth in  claim 13   wherein the phosphonic acid is  2 -carboxyethane phosphonic acid.    
     
     
         24 . A process as set forth in  claim 13   wherein the organophosphate is dioctylphosphite.    
     
     
         25 . A process for producing a corrosion-stable aluminum-based metal pigment comprising: 
 producing an aluminum or aluminum based alloy metal film by means of physical vapor deposition (pvd) and    subsequent crushing of the metal film by ultrasound or agitator    wherein the pigment obtained by the crushing operation is treated during said crushing of the metal film with at least one substance selected from the group consisting of phosphonic acids, phosphoric acids, phosphoric acid esters, organophosphites and derivatives of said substances in the absence of a required solvent to produce a passivating protective layer on the free metal surfaces of the pigment.    
     
     
         26 . A process as set forth in  claim 25   wherein the pigment is treated with a derivative having between 8 and 20 C-atoms of said substances.    
     
     
         27 . A process as set forth in  claim 25   wherein the pigment is treated in a solution of at least one salt-like compound of said substances.    
     
     
         28 . A process as set forth in  claim 25   wherein the pigment is treated in a solution of at least one salt-like compound of said derivatives.    
     
     
         29 . A process as set forth in  claim 25   wherein the operation of applying the passivating protective layer to the free metal surfaces of the pigment particles is effected during the operation of crushing the metal film produced by PVD.    
     
     
         30 . A process as set forth in  claim 25   wherein a substance forming at least a component of the passivating protective layer forms a release layer in production of the aluminum pigment by means of PVD and wherein during the operation of crushing the metal film the release layer is detached and applied as a protective layer to the free metal surfaces of the metal particles.    
     
     
         31 . A process as set forth in  claim 25   wherein a substance forming at least a component of the passivating protective layer forms a release layer in production of the aluminum pigment by means of PVD and wherein during the operation of crushing the metal film the release layer is detached and by the addition of a suitable protective layer component reacted with same and the resulting reaction product is applied as the protective layer.    
     
     
         32 . A process as set forth in  claim 25   wherein the phosphoric acid ester is in the form of a monobasic or polybasic acid.    
     
     
         33 . A process as set forth in  claim 25   wherein the phosphoric acid esters are based on higher fatty alcohols.    
     
     
         34 . A process as set forth in  claim 25   wherein the phosphoric acid ester is triethyl phosphate.    
     
     
         35 . A process as set forth in  claim 25   wherein the phosphonic acid is  2 -carboxyethane phosphonic acid.    
     
     
         36 . A process as set forth in  claim 25   wherein the organophosphate is dioctylphosphite.