Compositions: coating or plastic – Materials or ingredients – Pigment – filler – or aggregate compositions – e.g. – stone,...
Patent
1994-06-27
1995-11-28
Klemanski, Helene
Compositions: coating or plastic
Materials or ingredients
Pigment, filler, or aggregate compositions, e.g., stone,...
106419, 106429, 106499, 106503, 10628717, 10628723, 10628725, 10628729, 1062873, C09C 162, C09C 164
Patent
active
054703859
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
The present invention is related to paste compositions containing metal pigments suitable for forming coating compositions, particularly aqueous coating systems. Increasingly stringent environmental regulations have required that coating systems dramatically reduce volatile organic solvent levels. One way to comply with such regulations is to use water in place of the volatile organic solvents previously used.
However, in the area of coating systems utilizing metal pigment particles, aqueous systems present rather formidable difficulties. This is particularly true with respect to aluminum and zinc pigments. Thus, the metal pigment can readily react with water to generate hydrogen gas. The amount of gas generated can produce a safety hazard, creating high pressures within the composition containers. Also, the water reaction substantially diminishes the aesthetic value of metal pigments. The reaction of aluminum pigments with water can be depicted as follows:
Due to the increasing demand for aqueous systems, a number of techniques have been proposed for inhibiting the attack on the pigment particles by water. Unfortunately, most of these techniques have not provided sufficient protection.
One technique that provides inhibiting properties is the passivation of the metal pigment particles with an ionic organic phosphate as disclosed by Williams et al., U.S. Pat. No. 4,565,716. Other techniques involve the use of compounds containing pentavalent vanadium compounds as disclosed in Kondis U.S. Pat. No. 4,693,754, or the use of organic phosphites as disclosed in Kondis et al. U.S. Pat. No. 4,808,231. Another composition of matter utilized to produce an aluminum paste for use in aqueous systems uses nitroparaffin solvents to inhibit the evolution of hydrogen gas. However, through the addition of nitro-containing solvents we have improved upon the passivation of metal pigment particles utilizing organic phosphates, phosphites, or vanadium compounds.
SUMMARY OF THE INVENTION
The present invention provides a composition of matter which comprises metal particles treated with either (a) an ionic organic phosphate compound, for example as taught in Williams et al., U.S. Pat. No. 4,565,716, or (b) a pentavalent vanadium compound, for example as taught in Kondis, U.S. Pat. No. 4,693,754, or (c) an organic phosphite compound as taught in Kondis et al. U.S. Pat. No. 4,808,231, and a nitro-containing solvent such as a nitroparaffin. The treated metal pigment particles can be used to form a pigment paste. The metal particles, e.g. aluminum flakes, which have been treated with the phosphate, phosphite, or vanadate and nitro-containing compound are stabilized to a degree suitable for use in aqueous coating systems. The combination of the treatment with both the phosphate, phosphite, or vanadium compounds and the nitro-containing solvents produces a metal pigment paste which has improved gassing stability over the separately treated products. The nitro-containing solvent can be added to the pigment paste along with the phosphate, phosphite or vanadate, or it can be added to the paint vehicle either prior to or along with the pigment paste which has been treated with the phosphate, phosphite or vanadate.
DESCRIPTION OF THE PREFERRED EMBODIMENT
As indicated above, the present invention is based on the discovery that a combination of certain types of organic phosphate compounds, organic phosphite compounds or pentavalent vanadium compounds and a nitro-containing solvent effectively stabilizes metal pigments from reacting with water, rendering the pigment suitable for use in water-based coatings without significant degradation of optical properties. Either the phosphate compound, the phosphite compound, the vanadium compound or the nitro-containing solvent, used individually, provides some measure of stability for metal pigments in water-based coatings, but the combination of the nitro-containing solvent with either the phosphate, the phosphite or the vanadate provides greatly enhanced stability. Th
REFERENCES:
patent: 2848344 (1958-08-01), Brown
patent: 3890166 (1975-06-01), Kondis
patent: 4522655 (1985-06-01), Classen et al.
patent: 4565716 (1986-01-01), Williams, Jr.
patent: 4693754 (1987-09-01), Kondis
patent: 4808231 (1989-02-01), Kondis et al.
patent: 4885032 (1989-12-01), Okai et al.
patent: 5011533 (1991-04-01), Kuwajima et al.
patent: 5057156 (1991-10-01), Kuwajima et al.
patent: 5156677 (1992-10-01), Carpenter et al.
Jenkins William G.
Keemer Craig B.
Lamborn H. Taylor
Scheller Joseph B.
Klemanski Helene
Silberline Manufacturing Co., Ltd.
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