Effect pigments coated with reactive orientation aids
View Patent ↗The subject of the invention is an effect pigment which is coated with surface-modifying agents, wherein the initial pigment has a layer with at least one reactive surface-modifying agent, wherein the surface-modifying agent is a compound which has at least two functional groups which are different from each other and which are spaced by a spacer, chemically bound to the initial pigment. Also described is a process for the production of an effect pigment of that kind.
1. A surface modified flake-form metal pigment for use in a paint or lacquer containing a binding agent, comprising an initial flake-form pigment having on its surface a layer with at least one reactive organic solvent based surface-modifying agent,
wherein the surface-modifying agent is a compound having at least two terminal functional groups which are different from each other and which are spaced by a spacer,
wherein at least one terminal functional group is chemically bound to the surface of the initial pigment and at least one other terminal functional group is chemically reactive with the binding agent, and
wherein the metal pigment is of a particle size between about 1 and about 200 μm, is easily wetted by a binding agent or solvent of a paint or lacquer, is capable of being oriented in a liquid film of the paint or lacquer and is capable of forming an intimate chemical bond with the binding agent of said paint or lacquer upon baking or hardening of said paint or lacquer.
2. A metal pigment according to claim 1 wherein the surface modifying agent is in monomeric or polymeric form.
3. A metal pigment according to claim 1 wherein the surface modifying agent is chemically bound to the initial pigment by way of a reaction of at least one functional group selected from the group consisting of (RO) 3 Si—, (RO) 2 RSi—, R (3-z) X z Si—, and O═P(OR) x (OH) y —O w —, wherein within a functional group R can be the same or different and respectively represents C n H m , wherein n=1–30, m=3–61, z=1–3, X═Cl or Br and x=0–2, y=0–2, x+y=2 and w=0 or 1.
4. A metal pigment according to claim 1 , wherein the spacer is selected from the group consisting of alkyl chains, silanes, siloxanes, polyethers, thioethers, urethanes and combinations of those groupings having the general formula (C,Si) n H m (N,O,S) x with n=0–50, m=0–100 and x=0–50.
5. A metal pigment according to claim 1 , further comprising at least one functional group selected from the group consisting of an acrylate, methacrylate, isocyanate, a vinyl compound, amino group, cyano group, epoxy group and hydroxy group.
6. A metal pigment according to claim 1 , wherein the metal pigment is selected from the group consisting of aluminum, copper, zinc, gold-bronze, titanium, zirconium, tin, iron, steel and/or alloys thereof, multi-layer pigments and mixtures thereof.
7. A metal pigment according to claim 1 , wherein the initial pigment is coated with a layer comprising one or more metal oxides selected from the group consisting of silicon dioxide, titanium dioxide, aluminum dioxide, tin oxide, zinc oxide and iron oxide, or an organic polymer.
8. A metal pigment according to claim 1 , wherein an alkyl silane is present in said layer with the at least one reactive surface-modifying agent.
9. A metal pigment according to claim 1 wherein the reactive surface-modifying agent is contained in the layer in a proportion of between 10 and 100%.
10. A metal pigment according to claim 1 wherein said metal pigment will become a chemical constituent of said binding agent upon baking or hardening of said paint or lacquer.