Coating processes – With post-treatment of coating or coating material – Heating or drying
Reexamination Certificate
2000-01-27
2002-01-01
Cameron, Erma (Department: 1762)
Coating processes
With post-treatment of coating or coating material
Heating or drying
C427S381000
Reexamination Certificate
active
06335057
ABSTRACT:
TECHNICAL FIELD
The present invention relates to a novel process to form metallic multilayer coating films by using a non-leafing aluminum flake pigment.
BACKGROUND ART
It is already known to form metallic coating films by coating a metallic paint containing aluminum flake and then coating a clear paint and the process is being widely used for top coating of automobile outer panels etc. This metallic coating film has a glittering brilliance and is excellent in design ability. Said metallic coating film, however, consists mainly of resin component, non-leafing aluminum flake and color pigment, and aluminum flake often orientates irregularly in fact, contrary to an ideal orientation within the coating film which is uniform and parallel to the coating surface, and, therefore, it is difficult to form a metallic coating film, which is white, excellent in metallic luster impression and has a high flip-flop effect, which aluminum flake intrinsically possesses.
The purpose of the present invention is to provide a novel process to form a metallic coating film, which is white, excellent in metallic luster impression and has a high flip-flop effect, which aluminum flake intrinsically possesses by orientating the flake parallel to the coating surface, when forming a metallic coating film by using a non-leafing aluminum flake pigment.
This time it was found that the above-mentioned purpose could be achieved by using a coating composition which contains non-leafing aluminum flake and organic solvent but not substantially contains a resin component or contains low amount of it, even if it is contained.
DISCLOSURE OF THE INVENTION
Thus, according to the present invention it is provided a process to form metallic multilayer coating films characterized by coating on the uncured coating surface of a paint formed on a substrate with a composition (B), which contains non-leafing aluminum flake and organic solvent and less than 300 parts by weight (as solid content) of resin component per 100 parts by weight of non-leafing aluminum flake, and by coating, optionally after coating with a topcoat paint (C), with a clear paint (D) (hereinafter referred to as the process of the present invention).
Then the process of the present invention is described in more detail.
BEST MODE FOR CARRYING OUT THE INVENTION
Substrate
The substrate on which metallic multilayer coating films can be formed according to the process of the present invention is not particularly limited and there can be mentioned, for example, outer panels of bodies of motorcars such as passenger car, truck, motorcycle, bus etc. or outer panels of electric appliances, made of metal or plastics. Among them, metallic substrate is preferably chemically treated previously with phosphates, chromates etc. Moreover, such a substrates is preferably coated previously with an undercoat paint such as cationic electrodeposition paint and optionally further coated with an intermediate paint. As undercoat paint and intermediate paint there is no particular limitation and various kinds of per se known paints can be used.
Uncured Coating Surface
In the process of the present invention an uncured coating surface of a paint is formed first on a substrate. The basecoat paint used to form the uncured coating surface may be a substantially non-crosslinking, organic solvent type paint dryable at normal temperature. Generally, however, an organic solvent type thermocurable basecoat paint (A) is preferable.
The organic solvent type thermocurable basecoat paint (A) consists fundamentally of base resin, crosslinking agent and organic solvent. As a base resin there can be mentioned, for example, resins such as polyester resin, alkyd resin, acrylic resin, vinyl resin etc. having crosslinking functional group such as hydroxyl group etc. As a crosslinking agent there can be mentioned, for example, melamine resin, polyisocyanate compounds which may be blocked, etc., which crosslink with such a functional group. Further, as an organic solvent usual solvents for paint use such as hydrocarbons, esters, ethers, alcohols, ketones etc. can be used. The compounding ratio of base resin and crosslinking agent in the basecoat paint (A) is suitable in the range of 50-90%, particularly 60-80%, of base resin and 50-10%, particularly 40-20%, of crosslinking agent based upon the total weight of solid content of both components.
It is preferable to compound a resin composition containing phosphoric acid group in the basecoat paint (A) in order to improve the adhesivity with the coating film formed by coating of the composition (B) to be described later.
As a resin composition containing phosphoric acid group there can be mentioned, for example, substances shown below.
(P-1) A polymer containing in the molecule phosphoric acid group and hydroxyl group which contains an unsaturated monomer unit containing phosphoric acid group and an unsaturated monomer unit containing hydroxyl group as constitutional components.
(P-2) A non-aqueous dispersion containing phosphoric acid group consisting of dispersed polymer particles, which are polymer particles containing an unsaturated monomer unit containing phosphoric acid group as a constitutional component, in a solution of a high molecular dispersion stabilizer in an organic solvent.
The unsaturated monomer containing phosphoric acid group used in the preparation of the polymer (P-1) is a compound containing at least each one of a polymerizable unsaturated bond and a phosphoric acid group represented by the following formula (I) in the molecule.
—OPO(OH)(R
1
) (I)
wherein R
1
is hydroxyl group, phenyl group or alkyl group of carbon number 1-20.
As such unsaturated monomer containing phosphoric acid group there can be mentioned, for example, (meth)acryloyloxy-C
2-20
-alkyl acid phosphates such as (2-acryloyloxyethyl) acid phosphate, (2-methacryloyloxyethyl) acid phosphate, (2-acryloyloxypropyl) acid phosphate, (2-methacryloyloxypropyl) acid phosphate, 10-acryloyloxydecyl acid phosphate, 10-methacryloyloxydecyl acid phosphate etc. Furthermore an equimolar adduct of glycidyl (meth)acrylate and mono-C
1-20
alkylphosphoric acid can be used as an unsaturated monomer containing phosphoric acid group.
An unsaturated monomer containing hydroxyl group used in the preparation of the polymer (P-1) is a compound having hydroxyl group and polymerizable unsaturated bond in the molecule and there can be mentioned, for example, monoesters of a C
2-20
-alkylene glycol and (meth)acrylic acid such as hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate etc.
The polymer (P-1) can be prepared by copolymerizing the above-mentioned unsaturated monomer containing phosphoric acid group and unsaturated monomer containing hydroxyl group as essential components and, as necessary, other monomer and/or monomer containing N-alkoxymethylamide group etc.
The other monomers used in the preparation of the polymer (P-1) as necessary are other polymerizable unsaturated compounds than the above-mentioned unsaturated monomer containing phosphoric acid group, unsaturated monomer containing hydroxyl group and the monomer containing N-alkoxymethylamide group mentioned below and there can be mentioned, for example, a monoesterified compound of (meth)acrylic acid and a monohydric alcohol of carbon number 1-22, an olefin, styrene, acrylonitrile, vinyl acetate, vinyl chloride, (meth)acrylic acid, maleic acid, maleic anhydride etc.
The above-mentioned monomer containing N-alkoxymethylamide group is a compound having N-alkoxymethylamide group and polymerizable unsaturated bond in the molecule and there can be mentioned, for example, N-methoxymethyl (meth)acrylamide, N-ethoxymethyl (meth)acrylamide, N-butoxymethyl (meth)acrylamide, N-propoxymethyl (meth)acrylamide etc.
The polymer (P-1) can be prepared by copolymerizing the above-mentioned monomers according to per se known processes, for example, solution polymerization. The application ratio of the monomer containing phosphoric acid group and the monomer containing hydroxyl group in that case is prefer
Noura Kohsuke
Okumura Yasumasa
Sugai Hideo
Cameron Erma
Kansai Paint Co. Ltd.
Wenderoth , Lind & Ponack, L.L.P.
LandOfFree
Metallic multilayer coating films formation process does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Metallic multilayer coating films formation process, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Metallic multilayer coating films formation process will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2869844