Colored aluminum pigments, process for producing them and their use
AssigneeEckart-Werke Standard
InventorsWolfgang Reisser, Denise Mebarek
Life of this patent
Estimating the term…
Abstract
The invention concerns colored aluminum pigments comprising flake-form aluminum substrates which are coated with a metal oxide layer. The pigments are produced by a process which involves the steps of mixing a ground color pigment with a flake-form aluminum in the presence of a solvent. A metal acid ester is then added to the mixture and is then hydrolyzed to form a metal oxide layer on the aluminum substrate, followed by removal of the solvent and drying of the pigment. The pigments are useful as special-effect pigments in paints, lacquers, coatings, plastic materials, printing inks and cosmetic preparation.
Claims28
A colored aluminum pigment comprising a flake-form aluminum substrate coated with a single layer of metal oxide derived from a metal acid ester wherein the layer of the metal oxide contains at least one color pigment, not including carbon, metal and/or metal oxide, said color pigment selected from the group consisting of an organic color pigment, an inorganic color pigment, and a mixture of more than one color pigment present in the oxide layer in an amount of from 15 to 40% by weight with respect to the aluminum substrate.
A colored aluminum pigment prepared according to the process comprising the steps of:
- a) grinding at least one color pigment, selected from the group consisting of an organic color pigment, an inorganic color pigment and a mixture of more than one of said color pigments, but not including carbon, metal and/or metal oxide,
- b) forming a mix of the ground color pigment with an aluminum pigment in the presence of a water miscible organic solvent,
- c) adding at least one metal acid ester to the mix,
- d) hydrolyzing the metal acid ester by addition to the mix of from 1 to 5 times the amount of water which is stoichiometrically necessary for complete hydrolysis of the metal acid ester,
- e) at the end of the hydrolysis reaction, removing the organic solvent and other volatile constituents from the reaction mixture, and
- f) drying the resultant aluminum pigment.
A process for preparing a colored aluminum pigment comprising the steps of:
- a) grinding at least one color pigment selected from the group consisting of an organic color pigment, an inorganic color pigment, and a mixture of more than one of said color pigments, but not including carbon, metal and/or metal oxides,
- b) forming a mix of the ground color pigment with an aluminum pigment in the presence of a water miscible organic solvent,
- c) adding a metal acid ester to the mix,
- d) hydrolyzing the metal acid ester by addition to the mix of from 1 to 5 times the amount of water which is stoichiometrically necessary for complete hydrolysis of the metal acid ester,
- e) at the end of the hydrolysis reaction, removing the organic solvent and the other volatile constituents from the reaction mixture, and
- f) drying the resultant aluminum pigment.
Dependencies are inferred from the claim text.