Coating processes – Applying superposed diverse coating or coating a coated base – Synthetic resin coating
Patent
1997-11-25
1999-03-16
Dudash, Diana
Coating processes
Applying superposed diverse coating or coating a coated base
Synthetic resin coating
427195, 427379, 427409, 427458, B05D 138, B05D 302, B05D 726
Patent
active
058827340
DESCRIPTION:
BRIEF SUMMARY
This is the national phase of international application PCT/EP96/02234, filed 24 May 1996 which designated the U.S.
The invention relates to a process for preparing a multilayer lacquer coating for conductive, in particular metallic, substrates which is particularly well suited for the lacquer-coating of motor vehicles.
Present-day high-grade lacquers for the assembly-line lacquering of motor vehicles generally comprise an electrophoretically applied anticorrosive primer and subsequent coats which are then applied by spraying and comprise a filler layer and a subsequent layer which is applied for decorative purposes and consists of a colour-giving and/or effect-producing base coat, and a protective clear lacquer coat which seals the surface.
The overall thickness of such motor vehicle lacquers is, in practice, between 90 and 130 .mu.m which is the total produced by a layer thickness of 15 to 25 .mu.m for the primer, 30 to 40 .mu.m for the filler layer, 10 to 25 .mu.m for the base lacquer coat and 30 to 40 .mu.m for the clear lacquer coat. These layer thicknesses are far greater when it is intended to produce lacquer coatings which have a particularly good optical appearance, i.e. with a prominent lustre and coating lacquer condition, for example, when lacquer-coating motor vehicles in the upper and luxury classes. The application of a plurality of clear lacquer coats on to a base lacquer coat is described, for example, in DE-A-42 15 070 and DE-A-38 39 905. In such cases, layer thicknesses exceeding 110 .mu.m, for example up to 170 .mu.m, are produced, but this is undesirable for reasons relating to savings in the materials used and to reduction of the mass of the finished vehicle.
The object of the invention is to provide multilayer lacquer coatings, in particular motor vehicle lacquers, which meet the requirements with regard to a prominent lustre and coating lacquer condition, without exceeding the standard measure for overall layer thicknesses for motor vehicle lacquer coatings, and without any concomitant disadvantages in the overall level of properties.
It has been found that it was possible to meet this object in a novel manner according to the invention by a process for producing a multilayer lacquer coating, whereby a first coating layer of an electrophoretically depositable aqueous coating agent (1) is electrophoretically applied on to an electrically conductive substrate and is then stoved, whereupon further coating layers are applied, according to which process, as the coating agent (I), a coating agent which, in the stoved state, will produce an electrically conductive coating layer is used, whereupon, after stoving of the first coating layer, an electrically insulating second coating layer of an electrophoretically depositable aqueous coating agent (II), which differs from (I), is electrophoretically deposited and stoved, whereupon, as a third coating layer, a base lacquer coat of a colour-giving and/or effect-producing coating agent is applied, and a fourth transparent coating layer of a clear lacquer coating agent is applied, the last-mentioned two coats being stoved together, whereupon one or more further transparent coating layers are optionally applied, the overall dry layer thickness of the lacquer structure being between 90 and 130 .mu.m, preferably less than 110 .mu.m, and the dry layer thickness of the transparent coating layer or the overall layer thickness of the transparent coating layers being between 40 and 80 .mu.m, preferably between 50 and 60 .mu.m. When a plurality of clear lacquer coats is applied, these coats may be provided by the same or by different clear lacquer coating agents.
In the process according to the invention, it is possible to use, as the electrophoretically depositable but different coating agents (I) and (II), anodically or cathodically depositable electro-dipcoats (ETL), which are known per se, to produce the first and the second coating layer, it being imperative that the electrophoretically depositable coating agent (I) contain components which give an a
REFERENCES:
patent: 3674671 (1972-07-01), Stromberg
patent: 4755418 (1988-07-01), DebRoy et al.
patent: 4882090 (1989-11-01), Batzill et al.
patent: 4911811 (1990-03-01), Mullaney, Jr.
patent: 4933214 (1990-06-01), Sugiura et al.
patent: 5114756 (1992-05-01), Mirabeau et al.
patent: 5203975 (1993-04-01), Richardson
patent: 5389406 (1995-02-01), Doebler et al.
patent: 5395659 (1995-03-01), Graf et al.
patent: 5425970 (1995-06-01), Lahrmann et al.
patent: 5507928 (1996-04-01), Bohmert et al.
patent: 5721018 (1998-02-01), Goldner et al.
Blum Joachim
Engel Dieter
Kimpel Matthias
Klein Klausjorg
Kuhhirt Walter
Dudash Diana
Herberts Gesellschaft mit beschrankter Haftung
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