Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Processes of preparing a desired or intentional composition...
Patent
1996-08-23
1998-06-02
Cain, Edward J.
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Processes of preparing a desired or intentional composition...
524158, 524159, 524160, 524161, 524162, 524495, 524496, 524501, C08K 542
Patent
active
057601127
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
This invention relates to a water-borne autodepositing coating composition that has an excellent storage stability and that, when brought into contact with an electrochemically active metal surface, e.g., a surface of iron, zinc, iron alloy, or zinc alloy, efficiently coats the metal surface with a high-quality resin coating. This water-borne autodepositing coating composition is an acidic aqueous coating composition that contains water-dispersible or water-soluble organic coating-forming resin, pigment, acid, and oxidizing agent as essential components and may contain metal ions as an optional component.
BACKGROUND ART
Autodepositing coating compositions are acidic compositions containing organic coating-forming resin that are able to form a resin coating on the surface of an active metal brought into contact with the coating composition. Autodepositing coating compositions are disclosed, inter
When a clean active metal surface is immersed in an autodepositing coating composition, a resin coating is formed thereon in such a manner that the coating increases in thickness or weight with increasing immersion time. Coating formation by this type of composition is achieved through the chemical activity of the coating composition on the metal surface: Metal ions are eluted from the metal surface by etching, and these metal ions interact with the resin particles to cause their deposition on the metal surface. Thus, unlike electrodeposition processes, autodepositing coating compositions are able to efficiently form a resin coating on metal surfaces without the use of an external source of electricity.
When coloring is desired, pigment can be added to autodepositing coating compositions in order, for example, to increase the corrosion resistance or impart the desired tinctorial strength or degree of color. Japanese used based on the specific type of pigment used and the desired coating discloses the formation of colored coatings by immersion of the substrate in autodepositing coating compositions containing various types of pigments.
With respect to the selection of pigment type, Japanese Patent Publication Number Sho 53-44949 teaches that there are no specific restrictions on type as long as the pigment is stable in the bath. Japanese Patent Application Laid Open Number Sho 60-58474 discloses a dispersant for maintaining the pigment particles in a dispersed state and teaches that the pigment dispersion should be selected in such a manner that the dispersant concentration in the aqueous phase of the autodepositing coating composition does not exceed the critical micelle concentration ("CMC").
U.S. Pat. No. 4,177,180 discloses autodepositing coating compositions in which the pigment particles are dispersed and stabilized by non-ionic dispersant and also discloses a method for the preparation of such compositions. However, U.S. Pat. No. 4,177,180 also states that a uniform coating appearance cannot be obtained when a colored coating is produced using pigment dispersed in the form of an autodepositing coating composition.
Otherwise, no examples are believed to have heretofore been reported with regard to the dispersion stability of pigmented autodepositing coating compositions as a function of the type of dispersant used to disperse and stabilize the pigment particles or with regard to the properties of coatings formed by substrate immersion in autodepositing coating compositions containing specific pigments.
DISCLOSURE OF THE INVENTION
Problems to Be Solved by the Invention
The invention takes as its object the introduction of a black pigment-containing autodepositing coating composition that is able to generate a black coating of uniform appearance, that exhibits a very good storage stability, and that forms a strongly adherent and highly corrosion-resistant coating.
Summary of the Invention
As a result of extensive investigations directed at solving the problems described above, the inventors discovered for the first time that very significant results are obtained by the use in otherwi
REFERENCES:
patent: 3709743 (1973-01-01), Dalton et al.
patent: 3795546 (1974-03-01), Hall et al.
patent: 3829371 (1974-08-01), Miki et al.
patent: 4103049 (1978-07-01), Nishida et al.
patent: 4177180 (1979-12-01), Hall
patent: 4297259 (1981-10-01), Papalos et al.
patent: 4411937 (1983-10-01), Nishida et al.
patent: 4578419 (1986-03-01), Hall
patent: 4874673 (1989-10-01), Donovan et al.
Hatano Norifumi
Hirota Mutsumi
Honda Takumi
Saiki Shunjiro
Sangenya Shoichi
Cain Edward J.
Henkel Corporation
Jaeschke Wayne C.
Robbins Frank E.
Wisdom, Jr. Norvell E.
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