EP0839073A1 - Multi-coat painting process - Google Patents

Multi-coat painting process

Info

Publication number
EP0839073A1
EP0839073A1 EP96919803A EP96919803A EP0839073A1 EP 0839073 A1 EP0839073 A1 EP 0839073A1 EP 96919803 A EP96919803 A EP 96919803A EP 96919803 A EP96919803 A EP 96919803A EP 0839073 A1 EP0839073 A1 EP 0839073A1
Authority
EP
European Patent Office
Prior art keywords
coating
layer
coating layer
coating agent
layers
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP96919803A
Other languages
German (de)
French (fr)
Other versions
EP0839073B1 (en
Inventor
Joachim Blum
Dieter STRANGHÖNER
Dieter Engel
Klausjörg Klein
Walter KÜHHIRT
Matthias Kimpel
Friedrich-Ludwig Siever
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
EIDP Inc
Original Assignee
Herberts GmbH
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Family has litigation
First worldwide family litigation filed litigation Critical https://patents.darts-ip.com/?family=7763138&utm_source=google_patent&utm_medium=platform_link&utm_campaign=public_patent_search&patent=EP0839073(A1) "Global patent litigation dataset” by Darts-ip is licensed under a Creative Commons Attribution 4.0 International License.
Application filed by Herberts GmbH filed Critical Herberts GmbH
Publication of EP0839073A1 publication Critical patent/EP0839073A1/en
Application granted granted Critical
Publication of EP0839073B1 publication Critical patent/EP0839073B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D7/00—Processes, other than flocking, specially adapted for applying liquids or other fluent materials to particular surfaces or for applying particular liquids or other fluent materials
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D7/00—Processes, other than flocking, specially adapted for applying liquids or other fluent materials to particular surfaces or for applying particular liquids or other fluent materials
    • B05D7/50—Multilayers
    • B05D7/56—Three layers or more
    • B05D7/57—Three layers or more the last layer being a clear coat
    • B05D7/576—Three layers or more the last layer being a clear coat each layer being cured, at least partially, separately
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D7/00—Processes, other than flocking, specially adapted for applying liquids or other fluent materials to particular surfaces or for applying particular liquids or other fluent materials
    • B05D7/50—Multilayers
    • B05D7/56—Three layers or more
    • B05D7/57—Three layers or more the last layer being a clear coat
    • B05D7/577—Three layers or more the last layer being a clear coat some layers being coated "wet-on-wet", the others not

Definitions

  • the invention relates to a method for producing a multilayer coating of conductive, in particular metallic substrates, which is particularly suitable for automotive coating.
  • Today's high-quality automotive OEM coatings generally consist of an electrophoretically applied primer that protects against corrosion and subsequently spray-applied subsequent layers consisting of a filler layer and a subsequently applied decorative coating of coloring and / or effect basecoat and a protective clearcoat layer that seals the surface.
  • the total layer thickness of such automotive coatings is in practice between 90 and 130 ⁇ m, which is the sum of 15 to 25 ⁇ m layer thickness for the primer, 30 to 40 ⁇ m for the filler layer, 10 to 25 ⁇ m for the basecoat layer and 30 to 40 ⁇ m for the Clear coat results.
  • layer thicknesses are considerably exceeded if paintwork with a particularly good visual appearance, i.e. with outstanding gloss and top coat level, for example, in the painting of motor vehicles of the luxury and luxury class.
  • DE-A-42 15070 and DE-A-3839905 describe the application of several layers of clear lacquer to one basecoat. This then results in layer thicknesses of over 110 ⁇ m, e.g. up to 170 ⁇ m, which is undesirable for reasons of material savings and weight savings on the finished vehicle.
  • the object of the invention is to provide multi-layer coatings, in particular automotive coatings, which meet the requirements of an outstanding gloss and topcoat level, without the normal measure of the total layer thicknesses of automotive to exceed paintwork and without having to accept disadvantages in the overall property level.
  • Multi-layer coating in which a first coating layer of an electrophoretically depositable aqueous coating agent (I) is applied electrophoretically and then baked on an electrically conductive substrate, whereupon further coating layers are applied, which is characterized in that as
  • Coating agent (I) uses one which leads to an electrically conductive coating layer in the baked state, whereupon after baking the first coating layer, an electrically insulating second coating layer is electrophoretically deposited and baked from an aqueous coating agent (II) that can be separated from (I) , whereupon a basecoat layer composed of a coloring and / or effect-imparting coating agent is applied as the third coating layer and overpainted and baked with a fourth, transparent coating layer made of a clear lacquer coating agent, whereupon one or more further transparent coating layers are applied, where appropriate, the total dry layer thickness of the lacquer structure is between 90 and 130 ⁇ m, preferably less than 110 ⁇ m, and the dry layer thickness of the transparent coating layer or the total layer thickness of the transparent coating layers is between en is 40 and 80 ⁇ m, preferably between 50 and 60 ⁇ m. If several layers of clear lacquer are applied, they can be created from the same or different clear lacquer coating agents.
  • ETL electrophoretically depositable, but different, coating agents (I) and (II), in order to produce the first and second coating layers, it being true that the electrophoretically depositable coating agent (I ) Contains constituents which, in the baked state, of the first coating layer are used for the electrophoretic deposition of a further coating layer from one of (I) give various electrophoretically depositable coating agents (II) sufficiently low resistivity.
  • the coating compositions (I) and (II) are aqueous coating compositions with a solids content of, for example, 10 to 20% by weight.
  • This consists of conventional binders, at least some of the binders bearing ionic and / or substituents which can be converted into ionic groups, and, if appropriate, groups capable of chemical crosslinking, and any crosslinking agents, electrically conductive constituents, fillers, pigments and additives customary in lacquers.
  • the ionic groups or groups of the binders which can be converted into ionic groups can be anionic or groups which can be converted into anionic groups, acidic groups such as -C00H, -S0 3 H and / or -P0 3 H 2 and the corresponding anionic groups neutralized with bases. They can also be cationic or convertible into cationic groups, for example basic groups, preferably nitrogen-containing basic groups; these groups can be present in quaternized form or they are converted into ionic groups using a conventional neutralizing agent, for example an organic monocarboxylic acid, such as, for example, formic acid or acetic acid. Examples are amino, ammonium, for example quaternary ammonium, phosphonium and / or sulfonium groups.
  • the usual anionic group-containing anodically depositable electrocoat binders and paints can be used to produce the first and / or second coating layer.
  • ATL anionic group-containing anodically depositable electrocoat binders and paints
  • Epoxy resin esters (meth) acrylic copolymer resins, maleate oils or polybutadiene oils with a weight average molecular weight (Mw) of, for example, 300-10000 and an acid number of 35-300 mg KOH / g.
  • the binders carry -C00H, -S0 3 H and / or -P0 3 H 2 groups. After neutralization of at least some of the acidic groups, the resins can be converted into the water phase.
  • the binders can be self-crosslinking or externally crosslinking.
  • the paints can therefore also Usual crosslinkers contain, for example triazine resins, crosslinkers which contain groups capable of transesterification or blocked polyisocyanates.
  • the usual cathodic electrocoat materials (KTL) based on cationic or basic binders can also be used in the process according to the invention for producing the first and / or second coating layer.
  • Such basic resins are, for example, primary, secondary and / or tertiary amino groups-containing resins whose amine numbers are e.g. are 20 to 250 mg KOH / g.
  • the weight average molar mass (Mw) of the base resins is preferably 300 to 10,000.
  • base resins are amino (meth) acrylate resins, aminoepoxide resins, aminoepoxy resins with terminal double bonds, amino epoxy resins with primary OH groups, aminopolyurethane resins, amino group-containing polybutadiene resins Carbon dioxide-amine reaction products. These base resins can be self-crosslinking or they are used in a mixture with known crosslinking agents. Examples of such crosslinkers are aminoplast resins, blocked polyisocyanates, crosslinkers with terminal double bonds, polyepoxide compounds or crosslinkers which contain groups capable of transesterification.
  • Examples of base resins and crosslinking agents which can be used in cathodic immersion baths are in EP-A-0082 291, EP-A-0 234395, EP-A-0227 975, EP-A-0 178531, EP-A-0 333 327, EP-A-0 310 971, EP-A-0 455 270, US 3922 253, EP-A-0261 385, EP-A-0 245 786, DE-A-33 24 211, EP-A- 0414 199, EP-A-0476514. These resins can be used alone or in a mixture.
  • non-yellowing CTL systems are preferably used, which prevent yellowing or discoloration of the multi-layer coatings produced by the process according to the invention during stoving.
  • KTL systems that crosslink using specially selected blocked polyisocyanates, as described, for example, in EP-A-0 265 363.
  • the electrocoat (ETL) coating agent (I) contains components that impart electrical conductivity. They should be one of the first coating layer in the baked state for electrophoretic Deposition of a further coating layer from the electrophoretically depositable coating agent (II) impart a sufficiently low specific resistance, for example between 10 3 and 10 s Ohm.cm.
  • Such constituents are particulate inorganic 5 or organic electrical conductors or semiconductors, such as, for example, iron oxide black, graphite, carbon black, metal powder, for example made of aluminum, copper or stainless steel, molybdenum disulfide or polymers with electrical conductivity, such as preferably polyaniline.
  • Examples of electrodeposition paints containing such constituents can be found in US 3,674,671, GB 2,129,807, EP-A-0409821 and EP-A-0426 327.
  • the constituents imparting electrical conductivity are in the ETL coating agent (I) contained in an amount such that the desired specific resistance of the coating layer deposited therefrom is achieved in the baked state.
  • the proportion of the constituent (s) which confer electrical conductivity is, for example, between 1 and 30% by weight.
  • the proportion can easily be determined by a specialist; it depends, for example, on the specific weight, the specific electrical conductivity and the particle size of the constituents imparting electrical conductivity.
  • One or more of these components can be present in combination.
  • Coating layer in the baked state components imparting electrical conductivity can contain the ETL coating compositions (I) and (II) pigments, fillers and / or additives customary in lacquers.
  • Suitable pigments are, for example, the customary inorganic and / or organic colored pigments and / or fillers. Examples are titanium dioxide, iron oxide pigments, phthalocyanine pigments, quinacridone pigments, kaolin, talc, silicon dioxide or coarse coal as black pigments, finely divided soot produced by incomplete combustion, coarse soot obtained by catalytic or thermal decomposition of liquid or gaseous hydrocarbons.
  • the pigments can be dispersed into pigment pastes, for example using known paste resins. Resins of this type are familiar to the person skilled in the art. Examples of paste resins that can be used in KTL baths are described in EP-A-0 183025 and in EP-A-0469 497.
  • additives as are known in particular for ETL coating agents, are possible as additives.
  • these are wetting agents, neutralizing agents, leveling agents, catalysts, corrosion inhibitors, antifoams, solvents, but in particular light stabilizers, if appropriate in combination with antioxidants.
  • the basecoats which can be used according to the invention for the production of the third coating layer can be physically drying or can be crosslinked to form covalent bonds.
  • Formation of covalent crosslinking basecoats can be self- or externally crosslinking systems.
  • the color and / or effect basecoats which can be used in the process according to the invention are liquid coating compositions. It can be a one- or multi-component coating agent, single-component are preferred. It can be systems based on organic solvents or it is preferably water-based paints, the binder systems of which are suitable, e.g. anionic, cationic or non-ionic, are stabilized.
  • the basecoat coating compositions which can be used are conventional lacquer systems which contain one or more conventional base resins as film-forming binders. If the base resins are not self-crosslinking or self-drying, they can optionally also contain crosslinking agents. Both the base resin component and the crosslinker component are not subject to any limitation. Polyester, polyurethane and / or (meth) acrylic copolymer resins, for example, can be used as film-forming binders (base resins). In the case of the preferred waterborne basecoats, polyurethane resins are preferably present, particularly preferably at least in a proportion of 15% by weight, based on the solid resin content of the waterborne basecoat.
  • crosslinking agents which may be present is not critical, it depends on the functionality of the base resins, ie the crosslinking agents are selected such that they have a reactive functionality which is complementary to the functionality of the base resins.
  • Examples of such complementary functionalities between base resin and crosslinker are: hydroxyl / methylol ether, hydroxyl / free isocyanate, hydroxyl / blocked isocyanate, carboxyl / epoxide. If compatible with one another, several such complementary functionalities can also be present side by side in a basecoat.
  • the crosslinking agents optionally used in the basecoats can be present individually or in a mixture.
  • the basecoats used in the process according to the invention contain inorganic and / or organic colored pigments and / or effect pigments, such as, for example, titanium dioxide, iron oxide pigments, carbon black, azo pigments, phthalocyanine pigments, quinacridone pigments, and metal pigments, for example from aluminum pigments or copper, interference pigments, such as, for example, titanium dioxide-coated aluminum, coated mica, graphite effect pigments, platelet-shaped / iron oxide, platelet-shaped copper pthalocyanine pigments and effect pigments which develop a strong color flop, in particular on dark substrates.
  • inorganic and / or organic colored pigments and / or effect pigments such as, for example, titanium dioxide, iron oxide pigments, carbon black, azo pigments, phthalocyanine pigments, quinacridone pigments, and metal pigments, for example from aluminum pigments or copper, interference pigments, such as, for example, titanium dioxide-coated aluminum, coated mica, graphite effect pigments, platelet-shaped
  • effect pigments are described in EP-A-0358 208, EP-A-0 383 376, EP-A-0 601 483, EP-A-0 686 674, EP-A-0688833, US 4,434,010, WO 95 17 480, WO 95 32 247, WO 95 32 248.
  • Basecoat materials containing such effect pigments are preferably applied to dark, particularly preferably to black, two-layered coatings multi-layer coatings produced by electrocoating.
  • the basecoats may also contain customary paint additives, e.g. Fillers, catalysts, leveling agents, anti-cratering agents or, in particular, light stabilizers, optionally in combination with antioxidants.
  • customary paint additives e.g. Fillers, catalysts, leveling agents, anti-cratering agents or, in particular, light stabilizers, optionally in combination with antioxidants.
  • solvent-based basecoat systems which can be used in the process according to the invention can be found in DE-A-37 15254, DE-A-39 13001, DE-A-41 15948, DE-A-42 18 106, EP-A- 0289 997 and W0-91 00895.
  • waterborne basecoat systems which can preferably be used in the process according to the invention can be found in DE-A-29 26 584, DE-A-36 28 124,
  • the electrocoating lacquer used to produce the second coating layer has a color tone which is close to or identical to that of the basecoat used to produce the third coating layer.
  • the closest color tones are to be understood to mean that the difference in color, comprising the difference in brightness, hue and difference in color, between the hues of the second and third coating layers determined in each case with opaque coating and a measurement geometry of (45/0 °) n-fold ⁇ E * (CIELAB) value does not exceed, the ⁇ E * (CIELAB) reference value being that which is shown in the CIE x, y diagram (chromaticity diagram) familiar to the person skilled in the art based on DIN 6175 for the The color of the third coating layer results and the following relationship applies:
  • all customary clear lacquers or transparent colored or colorless pigmented coating compositions are suitable as clear coating compositions for the production of the fourth and possibly further coating layers.
  • These can be single-component or multi-component clear lacquer coating compositions. They can be solvent-free (liquid or as a powder clearcoat), or they can be systems based on solvents, or they can be water-dilutable clearcoats, the binder systems of which are suitable, e.g. anionic, cationic or non-ionic, are stabilized.
  • the water-dilutable clear lacquer systems can be water-soluble or water-dispersed systems, for example emulsion systems or powder slurry systems.
  • the clear lacquer coating agents harden when stoved to form covalent bonds as a result of chemical crosslinking.
  • the clearcoats which can be used in the process according to the invention are customary clearcoat coating compositions which contain one or more customary base resins as film-forming binders. If the base resins are not self-crosslinking, they may also contain crosslinking agents. Both the base resin component and the crosslinker component are not subject to any limitation. Polyester, polyurethane and / or (meth) acrylic copolymer resins, for example, can be used as film-forming binders (base resins).
  • base resins polyester, polyurethane and / or (meth) acrylic copolymer resins, for example, can be used as film-forming binders (base resins).
  • the selection of the crosslinking agents that may be present is not critical; it depends on the functionality of the base resins, i.e. the crosslinkers are selected so that they have a reactive functionality which is complementary to the functionality of the base resins. Examples of such complementary functionalities between base resin and crosslinker are: carboxyl / epoxy, something directly bound to carbon or
  • hydroxyl groups bonded directly to silicon also include latent silanol groups, such as, for example Alkoxysilane groups to understand. If compatible with one another, several such complementary functionalities can also be present side by side in a clear lacquer.
  • the crosslinking agents optionally used in the clear lacquers can be present individually or in a mixture. 5
  • Examples of one (1K) and two-component (2K) non-aqueous clearcoat systems which can be used as clearcoat in the process according to the invention can be found in DE-A-38 26 693, DE-A-40 17 075, DE-A -41 24 167, DE-A-41 33704, DE-A-42 04 518, DE-A-42 04 611, EP-A-0 257 513, EP-A-0408858, EP-A-0 523 267, EP-A-0 557 822, W0-92 11 327.
  • Water clearcoat systems which can be used as clearcoat in the process according to the invention can be found in DE-A-39 10829, DE-A-4009 931, DE-A-4009932, DE-A-41 01 696, DE-A-41 32 430 , DE-A-41 34 290, DE-A-42 03510, EP-A-0365098, EP-A-0365775, EP-A-0496079, EP-A-0546640.
  • Examples of the powder clearcoat systems preferably used in the process according to the invention for producing the transparent coating layer can be found in EP-A-0 509 392, EP-A-0 509 393, EP-A-0 522648, EP-A-0 544 206, EP- A-0 555 705, DE-A-42 22 194, DE-A-42 27 0 580.
  • the transparent coating can be applied in a single layer or in the form of several layers from the same or from several different transparent coating agents.
  • the 5 transparent coating layer is expediently applied as a fourth layer comprising only one clear lacquer coating agent.
  • Clear coating compositions which are as low as possible are preferably used Have a tendency to run off, for example, high-solids clear lacquers with a correspondingly adjusted rheological behavior. Powder clearcoats are particularly preferred.
  • Electrically conductive materials such as metals are suitable as the substrate for the method according to the invention.
  • automobile bodies or parts thereof are particularly suitable; they can be made of pretreated or untreated metal or electrically conductive or provided with an electrically conductive layer.
  • the first coating layer of the aqueous coating agent (I) is deposited electrophoretically on these substrates in a customary manner in a dry layer thickness of, for example, 5 to 15 ⁇ m and, for example, baked at temperatures between 130 and 180 ° C.
  • the second coating layer made of a second coating agent (II) different from (I) different from (I) and having a dry layer thickness of, for example, from 5 to 10 ⁇ m is coated on the substrate thus obtained, which has a specific resistance of 10 3 to 10 s ohm.cm. 35 ⁇ m, preferably between 10 to 25 ⁇ m, applied and likewise baked, for example, at temperatures between 130 and 180 ° C.
  • the second coating layer generally has practically no electrical conductivity, ie it has a specific resistance of more than 10 9 ohm.cm in the baked state.
  • the coating obtained by electrodeposition from the coating agent (I) serves in particular to protect against chemical and corrosive attack, so that it is advantageous to coat the entire surface of a three-dimensional substrate, for example a body, if possible.
  • the coating obtained by electrodeposition from the coating agent (II) and electrically insulating in the baked state can, but does not have to cover the entire three-dimensional area
  • a possible double coating is, for example, a full-surface first coating
  • the third coating layer is then sprayed from the color and / or effect basecoat in a dry layer thickness of 10 to 25 ⁇ m, depending on the color, for example by 10 compressed air sprayers, airless sprayers or ESTA high-speed rotary sprayers.
  • the fourth coating layer is applied from a customary liquid or powder clearcoat (in this case it is a dry-in-wet application) and baked together with the third coating layer, for example at temperatures from 80 to 160 ° C. If necessary, further layers of clear lacquer from the
  • the layer thickness of the transparent coating layer or the total layer thickness of the transparent coating layers is between 40 and 80 ⁇ m, preferably between 50 and 60 ⁇ m.
  • the powder topcoat is based on a powder clearcoat binder / crosslinking system known per se, as described above, for example, in connection with the powder clearcoats.
  • the powder topcoat contains coloring and / or effect pigments, such as those described above for the basecoats.
  • the method according to the invention allows the production of multi-layer coatings, in particular automotive coatings with an overall level of properties comparable to that of the prior art and an improved gloss and topcoat level. It has been shown that excellent properties are achieved by the procedure according to the invention, although this makes it possible to dispense with conventional spray filler layers. Despite the high layer thickness when applying the clear lacquer, the total layer thicknesses of the multi-layer lacquers produced by the process according to the invention are very small. They are in particular 90 to 130 ⁇ m.

Landscapes

  • Life Sciences & Earth Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Wood Science & Technology (AREA)
  • Application Of Or Painting With Fluid Materials (AREA)
  • Processing And Handling Of Plastics And Other Materials For Molding In General (AREA)
  • Laminated Bodies (AREA)
  • Production Of Multi-Layered Print Wiring Board (AREA)
  • Reinforced Plastic Materials (AREA)

Abstract

PCT No. PCT/EP96/02234 Sec. 371 Date Nov. 25, 1997 Sec. 102(e) Date Nov. 25, 1997 PCT Filed May 24, 1996 PCT Pub. No. WO96/38235 PCT Pub. Date Dec. 5, 1996In a process for producing a multilayer lacquer coating, eg for motor vehicles, a first coating layer of an aqueous coating agent (1) is electrophoretically applied on to an electrically conductive substrate and is then stoved. As the coating agent (I), a coating agent which, in the stoved state, will produce an electrically conductive coating layer is used. An electrically insulating second coating layer of an aqueous coating agent (II), which differs from (I), is electrophoretically deposited and stoved. A third basic lacquer coating layer 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. One or more further transparent coating layers may be applied.

Description

Verfahren zur HehrschichtlackierunqProcess for multi-layer painting
Die Erfindung betrifft ein Verfahren zur Herstellung einer mehrschichtigen Lackierung leitfähiger, insbesondere metallischer Substrate, das besonders zur Kraftfahrzeuglackierung geeignet ist.The invention relates to a method for producing a multilayer coating of conductive, in particular metallic substrates, which is particularly suitable for automotive coating.
Heutige, hochwertige Kraftfahrzeugserienlackierungen bestehen im allgemeinen aus einer elektrophoretisch aufgebrachten vor Korrosion schützenden Grundierung und nachfolgend durch Spritzlackierung aufgebrachten Folgeschichten bestehend aus einer Füllerschicht und einer anschließend aufgebrachten dekorativen Zwecken dienenden Lackierung aus färb- und/oder effektgebender Basislackschicht und einer die Oberfläche versiegelnden schützenden Klarlackschicht.Today's high-quality automotive OEM coatings generally consist of an electrophoretically applied primer that protects against corrosion and subsequently spray-applied subsequent layers consisting of a filler layer and a subsequently applied decorative coating of coloring and / or effect basecoat and a protective clearcoat layer that seals the surface.
Die Gesamtschichtdicke derartiger Kraftfahrzeuglackierungen liegt in der Praxis zwischen 90 und 130 μm, die sich als Summe aus 15 bis 25 μm Schichtdicke für die Grundierung, 30 bis 40 μm für die Füllerschicht, 10 bis 25 μm für die Basislackschicht und 30 bis 40 μm für die Klarlackschicht ergibt. Diese Schichtdicken werden erheblich überschritten wenn Lackierungen mit besonders gutem optischem Erscheinungsbild, d.h. mit herausragendem Glanz und Decklackstand beispielsweise bei der Lackierung von Kraftfahrzeugen der Ober- und Luxusklasse erzielt werden sollen. In der DE-A-42 15070 und in der DE- A-3839905 wird beispielsweise der Auftrag mehrerer Klarlackschichten auf eine Basislackschicht beschrieben. Es ergeben sich dann Schichtdicken von über 110 μm, z.B. bis zu 170 μm, was aus Gründen der Materialersparnis und Gewichtsersparnis am fertigen Fahrzeug unerwünscht ist.The total layer thickness of such automotive coatings is in practice between 90 and 130 μm, which is the sum of 15 to 25 μm layer thickness for the primer, 30 to 40 μm for the filler layer, 10 to 25 μm for the basecoat layer and 30 to 40 μm for the Clear coat results. These layer thicknesses are considerably exceeded if paintwork with a particularly good visual appearance, i.e. with outstanding gloss and top coat level, for example, in the painting of motor vehicles of the luxury and luxury class. DE-A-42 15070 and DE-A-3839905, for example, describe the application of several layers of clear lacquer to one basecoat. This then results in layer thicknesses of over 110 μm, e.g. up to 170 μm, which is undesirable for reasons of material savings and weight savings on the finished vehicle.
Aufgabe der Erfindung ist die Bereitstellung von Mehrschicht- lackierungen, insbesondere Kraftfahrzeuglackierungen, die den Anforderungen eines herausragenden Glanzes und Decklackstandes genügen, ohne das normale Maß der Gesamtschichtdicken von Kraftfahrzeug- lackierungen zu überschreiten und ohne dabei Nachteile im Gesamteigenschaftsniveau hinnehmen zu müssen.The object of the invention is to provide multi-layer coatings, in particular automotive coatings, which meet the requirements of an outstanding gloss and topcoat level, without the normal measure of the total layer thicknesses of automotive to exceed paintwork and without having to accept disadvantages in the overall property level.
Es hat sich gezeigt, daß diese Aufgabe überraschenderweise gelöst werden kann durch ein Verfahren zur Herstellung einerIt has been shown that this object can surprisingly be achieved by a method for producing a
Mehrschichtlackierung, bei dem auf einem elektrisch leitfähigen Substrat eine erste Überzugsschicht aus einem elektrophoretisch abscheidbaren wäßrigen Uberzugsmittel (I) elektrophoretisch aufgetragen und anschließend eingebrannt wird, worauf weitere Überzugsshichten aufgebracht werden, das dadurch gekennzeichnet ist, daß man alsMulti-layer coating, in which a first coating layer of an electrophoretically depositable aqueous coating agent (I) is applied electrophoretically and then baked on an electrically conductive substrate, whereupon further coating layers are applied, which is characterized in that as
Uberzugsmittel (I) ein solches verwendet, das zu einer im eingebrannten Zustand elektrisch leitfähigen Überzugsschicht führt, worauf nach dem Einbrennen der ersten Überzugsschicht eine elektrisch isolierende zweite Überzugsschicht aus einem von (I) verschiedenen elektrophoretisch abscheidbaren wäßrigen Uberzugsmittel (II) elektrophoretisch abgeschieden und eingebrannt wird, worauf als dritte Überzugsschicht eine Basislackschicht aus einem färb- und/oder effektgebenden Uberzugsmittel aufgetragen wird und mit einer vierten, transparenten Überzugsschicht aus einem Klarlacküberzugsmittel überlackiert und mit diesem gemeinsam eingebrannt wird, worauf gegebenenfalls eine oder mehrere weitere transparente Überzugsschichten aufgetragen werden, wobei die Gesamttrockenschichtdicke des Lackaufbaus zwischen 90 und 130 μm, bevorzugt unter 110 μm liegt und die Trockenschichtdicke der transparenten Überzugsschicht oder die Gesamtschichtdicke der transparenten Überzugsschichten zwischen 40 und 80 μm, bevorzugt zwischen 50 und 60 μm beträgt. Werden mehrere Klarlackschichten aufgetragen, so können diese aus dem gleichen oder verschiedenen Klarlacküberzugsmitteln erstellt werden.Coating agent (I) uses one which leads to an electrically conductive coating layer in the baked state, whereupon after baking the first coating layer, an electrically insulating second coating layer is electrophoretically deposited and baked from an aqueous coating agent (II) that can be separated from (I) , whereupon a basecoat layer composed of a coloring and / or effect-imparting coating agent is applied as the third coating layer and overpainted and baked with a fourth, transparent coating layer made of a clear lacquer coating agent, whereupon one or more further transparent coating layers are applied, where appropriate, the total dry layer thickness of the lacquer structure is between 90 and 130 μm, preferably less than 110 μm, and the dry layer thickness of the transparent coating layer or the total layer thickness of the transparent coating layers is between en is 40 and 80 μm, preferably between 50 and 60 μm. If several layers of clear lacquer are applied, they can be created from the same or different clear lacquer coating agents.
Beim erfindungsgemäßen Verfahren können als elektrophoretisch abscheidbare, jedoch voneinander verschiedene Uberzugsmittel (I) und (II) an sich bekannte anodisch oder kathodisch abscheidbare Elektrotauchlacke (ETL) verwendet werden zur Erzeugung der ersten und zweiten Überzugsschicht, wobei gilt, daß das elektrophoretisch abscheidbare Uberzugsmittel (I) Bestandteile enthält, die der ersten Überzugsschicht im eingebrannten Zustand einen zur elektrophoretischen Abscheidung einer weiteren Überzugsschicht aus einem von (I) verschiedenen elektrophoretisch abscheidbaren Uberzugsmittel (II) ausreichend niedrigen spezifischen Widerstand verleihen.In the process according to the invention, known electrodeposition lacquers (ETL), which are known per se and can be deposited differently from one another, can be used as the electrophoretically depositable, but different, coating agents (I) and (II), in order to produce the first and second coating layers, it being true that the electrophoretically depositable coating agent (I ) Contains constituents which, in the baked state, of the first coating layer are used for the electrophoretic deposition of a further coating layer from one of (I) give various electrophoretically depositable coating agents (II) sufficiently low resistivity.
Bei den Überzugsmitteln (I) und (II) handelt es sich um wäßrige Uberzugsmittel mit einem Festkörper von beispielsweise 10 bis 20 Gew.- %. Dieser besteht aus üblichen Bindemitteln, wobei zumindest ein Teil der Bindemittel ionische und/oder in ionische Gruppen überführbare Substituenten sowie gegebenenfalls zur chemischen Vernetzung fähige Gruppen trägt, sowie gegebenenfalls vorhandenen Vernetzern, elektrisch leitfähigen Bestandteilen, Füllstoffen, Pigmenten und lacküblichen Additiven.The coating compositions (I) and (II) are aqueous coating compositions with a solids content of, for example, 10 to 20% by weight. This consists of conventional binders, at least some of the binders bearing ionic and / or substituents which can be converted into ionic groups, and, if appropriate, groups capable of chemical crosslinking, and any crosslinking agents, electrically conductive constituents, fillers, pigments and additives customary in lacquers.
Die ionischen Gruppen oder in ionische Gruppen überführbaren Gruppen der Bindemittel können anionische oder in anionische Gruppen überführbare Gruppen, sauren Gruppen, wie -C00H, -S03H und/oder -P03H2 und die entsprechenden, mit Basen neutralisierten anionischen Gruppen sein. Sie können auch kationische oder in kationische Gruppen überführbare, z.B. basische Gruppen, bevorzugt stickstoffhaltige basische Gruppen sein; diese Gruppen können quarternisiert vorliegen oder sie werden mit einem üblichen Neutralisationsmittel, z.B. einer organischen Monocarbonsäure, wie z.B. Ameisensäure oder Essigsäure in ionische Gruppen überführt. Beispiele sind Amino-, Ammonium-, z.B. quartäre Ammonium-, Phosponium-, und/oder Sulfonium-Gruppen.The ionic groups or groups of the binders which can be converted into ionic groups can be anionic or groups which can be converted into anionic groups, acidic groups such as -C00H, -S0 3 H and / or -P0 3 H 2 and the corresponding anionic groups neutralized with bases. They can also be cationic or convertible into cationic groups, for example basic groups, preferably nitrogen-containing basic groups; these groups can be present in quaternized form or they are converted into ionic groups using a conventional neutralizing agent, for example an organic monocarboxylic acid, such as, for example, formic acid or acetic acid. Examples are amino, ammonium, for example quaternary ammonium, phosphonium and / or sulfonium groups.
Im erfindungsgemäßen Verfahren können zur Herstellung der ersten und/oder zweiten Überzugsschicht beispielsweise die üblichen anionische Gruppen enthaltenden anodisch abscheidbaren Elektrotauchlack- Bindemittel und Lacke (ATL) verwendet werden. Beispiele sind solche, wie sie in der DE-A-2824418 beschrieben werden. Es handelt sich beispielsweise um Bindemittel auf Basis von Polyestern,In the process according to the invention, for example, the usual anionic group-containing anodically depositable electrocoat binders and paints (ATL) can be used to produce the first and / or second coating layer. Examples are those as described in DE-A-2824418. These are, for example, binders based on polyesters,
Epoxidharzestern, (Meth)acrylcopolymerharzen, Maleinatölen oder Polybutadienölen mit einem Gewichtsmittel der Molmasse (Mw) von beispielsweise 300- 10000 und einer Säurezahl von 35 - 300 mg KOH/g. Die Bindemittel tragen -C00H, -S03H und/oder -P03H2-Gruppen. Die Harze können nach Neutralisation von mindestens einem Teil der sauren Gruppen in die Wasserphase überführt werden. Die Bindemittel können selbstvernetzend oder fremdvernetzend sein. Die Lacke können daher auch übliche Vernetzer enthalten, z.B. Triazinharze, Vernetzer, die umesterungsfähige Gruppen enthalten oder blockierte Polyisocyanate.Epoxy resin esters, (meth) acrylic copolymer resins, maleate oils or polybutadiene oils with a weight average molecular weight (Mw) of, for example, 300-10000 and an acid number of 35-300 mg KOH / g. The binders carry -C00H, -S0 3 H and / or -P0 3 H 2 groups. After neutralization of at least some of the acidic groups, the resins can be converted into the water phase. The binders can be self-crosslinking or externally crosslinking. The paints can therefore also Usual crosslinkers contain, for example triazine resins, crosslinkers which contain groups capable of transesterification or blocked polyisocyanates.
Ebenfalls im erfindungsgemäßen Verfahren einsetzbar zur Herstellung der ersten und/oder zweiten Überzugsschicht sind die üblichen kathodischen Elektrotauchlacke (KTL) auf Basis kationischer bzw. basischer Bindemittel. Solche basischen Harze sind beispielsweise primäre, sekundäre und/oder tertiäre A inogruppen enthaltende Harze, deren Aminzahlen z.B. bei 20 bis 250 mg KOH/g liegen. Das Gewichtsmittel der Molmasse (Mw) der Basisharze liegt bevorzugt bei 300 bis 10000. Beispiele für solche Basisharze sind Amino(meth)acrylatharze, Aminoepoxidharze, Aminoepoxidharze mit endständigen Doppelbindungen, A inoepoxidharze mit primären OH-Gruppen, Aminopolyurethanharze, aminogruppenhaltige Polybutadienharze oder modifizierte Epoxidharz- Kohlendioxid-Amin-Umsetzungsprodukte. Diese Basisharze können selbstvernetzend sein oder sie werden mit bekannten Vernetzern im Gemisch eingesetzt. Beispiele für solche Vernetzer sind Aminoplastharze, blockierte Polyisocyanate, Vernetzer mit endständigen Doppelbindungen, Polyepoxidverbindungen oder Vernetzer, die umesterungsfähige Gruppen enthalten.The usual cathodic electrocoat materials (KTL) based on cationic or basic binders can also be used in the process according to the invention for producing the first and / or second coating layer. Such basic resins are, for example, primary, secondary and / or tertiary amino groups-containing resins whose amine numbers are e.g. are 20 to 250 mg KOH / g. The weight average molar mass (Mw) of the base resins is preferably 300 to 10,000. Examples of such base resins are amino (meth) acrylate resins, aminoepoxide resins, aminoepoxy resins with terminal double bonds, amino epoxy resins with primary OH groups, aminopolyurethane resins, amino group-containing polybutadiene resins Carbon dioxide-amine reaction products. These base resins can be self-crosslinking or they are used in a mixture with known crosslinking agents. Examples of such crosslinkers are aminoplast resins, blocked polyisocyanates, crosslinkers with terminal double bonds, polyepoxide compounds or crosslinkers which contain groups capable of transesterification.
Beispiele für in kathodischen Tauchlack (KTL)-Bädern einsetzbare Basisharze und Vernetzer sind in der EP-A-0082 291, EP-A-0 234395, EP-A-0227 975, EP-A-0 178531, EP-A-0 333 327, EP-A-0 310 971, EP-A-0 455 270, US 3922 253, EP-A-0261 385, EP-A-0 245 786, DE-A-33 24 211, EP-A-0414 199, EP-A-0476514 beschrieben. Diese Harze können allein oder im Gemisch eingesetzt werden. Bevorzugt werden sogenannte "non- yellowing"-KTL-Systeme eingesetzt, die eine Vergilbung oder Verfärbung der nach dem erfindungsgemäßen Verfahren hergestellten Mehrschichtlackierungen beim Einbrennen vermeiden. Beispielsweise handelt es sich dabei um mittels speziell ausgewählter blockierter Polyisocyanate vernetzende KTL-Systeme, wie beispielsweise in EP-A-0 265 363 beschrieben.Examples of base resins and crosslinking agents which can be used in cathodic immersion baths are in EP-A-0082 291, EP-A-0 234395, EP-A-0227 975, EP-A-0 178531, EP-A-0 333 327, EP-A-0 310 971, EP-A-0 455 270, US 3922 253, EP-A-0261 385, EP-A-0 245 786, DE-A-33 24 211, EP-A- 0414 199, EP-A-0476514. These resins can be used alone or in a mixture. So-called “non-yellowing” CTL systems are preferably used, which prevent yellowing or discoloration of the multi-layer coatings produced by the process according to the invention during stoving. For example, these are KTL systems that crosslink using specially selected blocked polyisocyanates, as described, for example, in EP-A-0 265 363.
Das Elektrotauchlack(ETL)-Überzugsmittel (I) enthält elektrische Leitfähigkeit vermittelnde Bestandteile. Sie sollen der ersten Überzugsschicht im eingebrannten Zustand einen zur elektrophoretischen Abscheidung einer weiteren Überzugsschicht aus dem elektrophoretisch abscheidbaren Uberzugsmittel (II) ausreichend niedrigen spezifischen Widerstand, beispielsweise zwischen 103 und 10s Ohm.cm verleihen. Beispiele für derartige Bestandteile sind teilchenförmige anorganische 5 oder organische elektrische Leiter oder Halbleiter, wie beispielsweise Eisenoxidschwarz, Graphit, Leitfähigkeitsruß, Metallpulver, z.B. aus Aluminium, Kupfer oder Edelstahl, Molybdändisulfid oder auch Polymere mit elektrischer Leitfähigkeit, wie z.B. bevorzugt Polyanilin. Beispiele für derartige Bestandteile enthaltende Elektrotauchlacke, die 0 erfindungsgemäß eingesetzt werden können, findet man in US 3 674 671, GB 2 129807, EP-A-0409821 und EP-A-0426 327. Die elektrische Leitfähigkeit verleihenden Bestandteile sind in dem ETL-Überzugsmittel (I) in einer derartigen Menge enthalten, daß der gewünschte spezifische Widerstand der daraus abgeschiedenen Überzugsschicht im eingebrannten 5 Zustand erreicht wird. Bezogen auf den Festkörpergehalt des ETL- Überzugsmittels (I) beträgt der Anteil des oder der elektrische Leitfähigkeit verleihenden Bestandteile beispielsweise zwischen 1 und 30 Gew.-%. Der Anteil kann vom Fachmann leicht ermittelt werden; er ist beispielsweise abhängig vom spezifischen Gewicht, der spezifischen 0 elektrischen Leitfähigkeit und der Teilchengröße der eingesetzten elektrische Leitfähigkeit verleihenden Bestandteile. Es können ein oder mehrere dieser Bestandteile in Kombination vorliegen.The electrocoat (ETL) coating agent (I) contains components that impart electrical conductivity. They should be one of the first coating layer in the baked state for electrophoretic Deposition of a further coating layer from the electrophoretically depositable coating agent (II) impart a sufficiently low specific resistance, for example between 10 3 and 10 s Ohm.cm. Examples of such constituents are particulate inorganic 5 or organic electrical conductors or semiconductors, such as, for example, iron oxide black, graphite, carbon black, metal powder, for example made of aluminum, copper or stainless steel, molybdenum disulfide or polymers with electrical conductivity, such as preferably polyaniline. Examples of electrodeposition paints containing such constituents, which can be used according to the invention, can be found in US 3,674,671, GB 2,129,807, EP-A-0409821 and EP-A-0426 327. The constituents imparting electrical conductivity are in the ETL coating agent (I) contained in an amount such that the desired specific resistance of the coating layer deposited therefrom is achieved in the baked state. Based on the solids content of the ETL coating agent (I), the proportion of the constituent (s) which confer electrical conductivity is, for example, between 1 and 30% by weight. The proportion can easily be determined by a specialist; it depends, for example, on the specific weight, the specific electrical conductivity and the particle size of the constituents imparting electrical conductivity. One or more of these components can be present in combination.
Zusätzlich zu den Basisharzen und gegebenenfalls vorhandenem Vernetzer '5 sowie den im ETL-Überzugsmittel (I) enthaltenen, der erstenIn addition to the base resins and any existing crosslinking agent '5 as well as the first ones contained in the ETL coating agent (I)
Überzugsschicht im eingebrannten Zustand elektrische Leitfähigkeit verleihenden Bestandteilen können die ETL-Überzugsmittel (I) und (II) Pigmente, Füllstoffe und/oder lackübliche Additive enthalten. Als Pigmente kommen beispielsweise die üblichen anorganischen und/oder 0 organischen Buntpigmente und/oder Füllstoffe in Frage. Beispiele sind Titandioxid, Eisenoxidpigmente, Phthalocyaninpigmente, Chinacridonpigmente, Kaolin, Talkum, Siliciumdioxid oder als Schwarzpigmente grobteilige Kohle, durch unvollständige Verbrennung erzeugter feinteiliger Ruß, durch katalytische oder thermische 5 Zersetzung von flüssigen oder gasförmigen Kohlenwasserstoffen gewonnener grobteiliger Ruß. Die Pigmente können zu Pigmentpasten dispergiert werden, z.B. unter Verwendung von bekannten Pastenharzen. Solche Harze sind dem Fachmann geläufig. Beispiele für in KTL-Bädern verwendbare Pastenharze sind in der EP-A-0 183025 und in der EP-A-0469 497 beschrieben.Coating layer in the baked state, components imparting electrical conductivity can contain the ETL coating compositions (I) and (II) pigments, fillers and / or additives customary in lacquers. Suitable pigments are, for example, the customary inorganic and / or organic colored pigments and / or fillers. Examples are titanium dioxide, iron oxide pigments, phthalocyanine pigments, quinacridone pigments, kaolin, talc, silicon dioxide or coarse coal as black pigments, finely divided soot produced by incomplete combustion, coarse soot obtained by catalytic or thermal decomposition of liquid or gaseous hydrocarbons. The pigments can be dispersed into pigment pastes, for example using known paste resins. Resins of this type are familiar to the person skilled in the art. Examples of paste resins that can be used in KTL baths are described in EP-A-0 183025 and in EP-A-0469 497.
Als Additive sind die üblichen Additive möglich, wie sie insbesondere für ETL-Überzugsmittel bekannt sind. Beispiele dafür sind Netzmittel, Neutralisationsmittel, Verlaufsmittel, Katalysatoren, Korrosionsinhibitoren, Antischaummittel, Lösemittel, insbesondere jedoch Lichtschutzmittel gegebenenfalls in Kombination mit Antioxidantien.The usual additives, as are known in particular for ETL coating agents, are possible as additives. Examples of these are wetting agents, neutralizing agents, leveling agents, catalysts, corrosion inhibitors, antifoams, solvents, but in particular light stabilizers, if appropriate in combination with antioxidants.
Es ist im erfindungsgemäßen Verfahren bevorzugt, als ETL-Überzugsmittel (I) ein KTL-Überzugs ittel und als ETL-Überzugsmittel (II) ein ATL- Uberzugsmittel zu verwenden.In the process according to the invention, it is preferred to use a cathodic acid coating agent as the ETL coating agent (I) and an ATL coating agent as the ETL coating agent (II).
Im erfindungsgemäßen Verfahren werden für die Erzeugung der dritten Überzugsschicht an sich bekannte färb- und/oder effektgebende Basislacküberzugsmittel verwendet, wie sie zur Herstellung von Basislack/Klarlack-Zweischichtlackierungen eingesetzt werden und in großer Zahl beispielsweise aus der Patentliteratur bekannt sind.In the process according to the invention, known coloring and / or effect-imparting basecoat coating compositions are used for the production of the third coating layer, as are used for the production of basecoat / clearcoat two-coat coatings and are known in large numbers, for example, from the patent literature.
Die für die Erzeugung der dritten Überzugsschicht erfindungsgemäß verwendbaren Basislacke können physikalisch trocknend oder unter Ausbildung kovalenter Bindungen vernetzbar sein. Bei den unterThe basecoats which can be used according to the invention for the production of the third coating layer can be physically drying or can be crosslinked to form covalent bonds. With the under
Ausbildung kovalenter Bindungen vernetzenden Basislacken kann es sich um selbst- oder fremdvernetzende Systeme handeln.Formation of covalent crosslinking basecoats can be self- or externally crosslinking systems.
Die im erfindungsgemäßen Verfahren verwendbaren färb- und/oder effektgebenden Basislacke sind flüssige Uberzugsmittel. Es kann sich um ein- oder mehrkomponentige Uberzugsmittel handeln, einkomponentige sind bevorzugt. Es kann sich um Systeme auf Basis organischer Lösemittel handeln oder es handelt sich bevorzugt um Wasserbasislacke, deren Bindemittelsysteme in geeigneter Weise, z.B. anionisch, kationisch oder nicht-ionisch, stabilisiert sind.The color and / or effect basecoats which can be used in the process according to the invention are liquid coating compositions. It can be a one- or multi-component coating agent, single-component are preferred. It can be systems based on organic solvents or it is preferably water-based paints, the binder systems of which are suitable, e.g. anionic, cationic or non-ionic, are stabilized.
Bei den im erfindungsgemäßen Verfahren für die Herstellung der dritten Überzugsschicht verwendbaren Basislacküberzugsmitteln handelt es sich um übliche Lacksysteme, die ein oder mehrere übliche Basisharze als filmbildende Bindemittel enthalten. Sie können, falls die Basisharze nicht selbstvernetzend oder selbsttrocknend sind, gegebenenfalls auch Vernetzer enthalten. Sowohl die Basisharzkomponente als auch die Vernetzerkomponente unterliegen keinerlei Beschränkung. Als filmbildende Bindemittel (Basisharze) können beispielsweise Polyester-, Polyurethan- und/oder (Meth)acrylcopolymerharze verwendet werden. Im Fall der bevorzugten Wasserbasislacke sind bevorzugt Polyurethanharze enthalten, besonders bevorzugt mindestens zu einem Anteil von 15 Gew.- %, bezogen auf den Festharzgehalt des Wasserbasislacks. Die Auswahl der gegebenenfalls enthaltenen Vernetzer ist unkritisch, sie richtet sich nach der Funktionalität der Basisharze, d.h. die Vernetzer werden so ausgewählt, daß sie eine zur Funktionalität der Basisharze komplementäre, reaktive Funktionalität aufweisen. Beispiele für solche komplementäre Funktionalitäten zwischen Basisharz und Vernetzer sind: Hydroxyl/Methylolether, Hydroxyl/Freies Isocyanat, Hydroxyl/Blockiertes Isocyanat, Carboxyl/Epoxid. Sofern miteinander verträglich, können auch mehrere solcher komplementärer Funktionalitäten in einem Basislack nebeneinander vorliegen. Die gegebenenfalls in den Basislacken verwendeten Vernetzer können einzeln oder im Gemisch vorliegen.In the process according to the invention for the production of the third The basecoat coating compositions which can be used are conventional lacquer systems which contain one or more conventional base resins as film-forming binders. If the base resins are not self-crosslinking or self-drying, they can optionally also contain crosslinking agents. Both the base resin component and the crosslinker component are not subject to any limitation. Polyester, polyurethane and / or (meth) acrylic copolymer resins, for example, can be used as film-forming binders (base resins). In the case of the preferred waterborne basecoats, polyurethane resins are preferably present, particularly preferably at least in a proportion of 15% by weight, based on the solid resin content of the waterborne basecoat. The selection of the crosslinking agents which may be present is not critical, it depends on the functionality of the base resins, ie the crosslinking agents are selected such that they have a reactive functionality which is complementary to the functionality of the base resins. Examples of such complementary functionalities between base resin and crosslinker are: hydroxyl / methylol ether, hydroxyl / free isocyanate, hydroxyl / blocked isocyanate, carboxyl / epoxide. If compatible with one another, several such complementary functionalities can also be present side by side in a basecoat. The crosslinking agents optionally used in the basecoats can be present individually or in a mixture.
Die beim erfindungsgemäßen Verfahren eingesetzten Basislacke enthalten neben den üblichen physikalisch trocknenden und/oder chemisch vernetzenden Bindemitteln anorganische und/oder organische Buntpigmente und/oder Effektpigmente, wie z.B. Titandioxid, Eisenoxidpigmente, Ruß, Azopigmente, Phthalocyaninpigmente, Chinacridonpigmente, Metallpigmente, z.B. aus Titan, Aluminium oder Kupfer, Interferenzpigmente, wie z.B. titandioxidbeschichtetes Aluminium, beschichteter Glimmer, Graphiteffektpigmente, plättchenförmiges /Eisenoxid, plättchenförmige Kupferpthalocyaninpigmente sowie Effektpigmente, die einen starken Farbflop insbesondere auf dunklen Untergründen entwickeln. Beispiele für derartige Effektpigmente sind beschrieben in EP-A-0358 208, EP-A-0 383 376, EP-A-0 601 483, EP-A-0 686 674, EP-A-0688833, US 4 434 010, WO 95 17 480, WO 95 32 247, WO 95 32 248. Bevorzugt werden derartige Effektpigmente enthaltende Basislacke auf dunkle, besonders bevorzugt auf schwarze zweischichtig durch Elektrotauchlackierung erzeugte Mehrschichtlackierungen appliziert.In addition to the usual physically drying and / or chemically crosslinking binders, the basecoats used in the process according to the invention contain inorganic and / or organic colored pigments and / or effect pigments, such as, for example, titanium dioxide, iron oxide pigments, carbon black, azo pigments, phthalocyanine pigments, quinacridone pigments, and metal pigments, for example from aluminum pigments or copper, interference pigments, such as, for example, titanium dioxide-coated aluminum, coated mica, graphite effect pigments, platelet-shaped / iron oxide, platelet-shaped copper pthalocyanine pigments and effect pigments which develop a strong color flop, in particular on dark substrates. Examples of such effect pigments are described in EP-A-0358 208, EP-A-0 383 376, EP-A-0 601 483, EP-A-0 686 674, EP-A-0688833, US 4,434,010, WO 95 17 480, WO 95 32 247, WO 95 32 248. Basecoat materials containing such effect pigments are preferably applied to dark, particularly preferably to black, two-layered coatings multi-layer coatings produced by electrocoating.
Weiterhin können die Basislacke lackübliche Additive enthalten, wie z.B. Füllstoffe, Katalysatoren, Verlaufsmittel, Antikratermittel oder insbesondere Lichtschutzmittel, gegebenenfalls in Verbindung mit Antioxidantien.The basecoats may also contain customary paint additives, e.g. Fillers, catalysts, leveling agents, anti-cratering agents or, in particular, light stabilizers, optionally in combination with antioxidants.
Beispiele für Basislacksysteme auf Lösemittelbasis, die im erfindungsgemäßen Verfahren eingesetzt werden können, findet man in DE- A-37 15254, DE-A-39 13001, DE-A-41 15948, DE-A-42 18 106, EP-A-0289 997 und W0-91 00895.Examples of solvent-based basecoat systems which can be used in the process according to the invention can be found in DE-A-37 15254, DE-A-39 13001, DE-A-41 15948, DE-A-42 18 106, EP-A- 0289 997 and W0-91 00895.
Beispiele für die im erfindungsgemäßen Verfahren bevorzugt einsetzbaren Wasserbasislacksysteme findet man in DE-A-29 26 584, DE-A-36 28 124,Examples of the waterborne basecoat systems which can preferably be used in the process according to the invention can be found in DE-A-29 26 584, DE-A-36 28 124,
DE-A-3841 540, DE-A-39 03804,DE-A-39 15459, DE-A-40 01 841, DE-A-40 09857, DE-A-40 11 633, DE-A-41 07 136, DE-A-41 22 266, EP-A-0 089 497, EP-A-0226 171, EP-A-0228003, EP-A-0 287 144, EP-A-0 297 576, EP-A-0 301 300, EP-A-0 353 797, EP-A-0 354 261, EP-A-0401 565, EP-A-0 424 705, EP-A-0 512 524 und EP-A-0 584818.DE-A-3841 540, DE-A-39 03804, DE-A-39 15459, DE-A-40 01 841, DE-A-40 09857, DE-A-40 11 633, DE-A-41 07 136, DE-A-41 22 266, EP-A-0 089 497, EP-A-0226 171, EP-A-0228003, EP-A-0 287 144, EP-A-0 297 576, EP-A -0 301 300, EP-A-0 353 797, EP-A-0 354 261, EP-A-0401 565, EP-A-0 424 705, EP-A-0 512 524 and EP-A-0 584818 .
Es ist bevorzugt, wenn der zur Erzeugung der zweiten Überzugsschicht verwendete Elektrotauchlack einen Farbton aufweist, der dem des zur Erzeugung der dritten Überzugsschicht verwendeten Basislacks nahekommt oder gleich ist. Bevorzugt ist unter einander nahekommenden Farbtönen im Rahmen der vorliegenden Erfindung zu verstehen, daß der sich aus Helligkeitsdifferenz, Bunttondifferenz und Buntheitsdifferenz zusammensetzende Farbabstand zwischen den jeweils bei deckender Lackierung und einer Meßgeometrie von (45/0°) bestimmten Farbtöne der zweiten und der dritten Überzugsschicht einen n-fachen ΔE*(CIELAB)-Wert nicht überschreitet, wobei als ΔE*(CIELAB)-Bezugswert derjenige gilt, der sich in dem dem Fachmann geläufigen CIE-x,y-Diagramm (Chromatizitätsdiagra m) in Anlehnung an DIN 6175 für den Farbton der dritten Überzugsschicht ergibt und wobei folgende Beziehung gilt:It is preferred if the electrocoating lacquer used to produce the second coating layer has a color tone which is close to or identical to that of the basecoat used to produce the third coating layer. In the context of the present invention, the closest color tones are to be understood to mean that the difference in color, comprising the difference in brightness, hue and difference in color, between the hues of the second and third coating layers determined in each case with opaque coating and a measurement geometry of (45/0 °) n-fold ΔE * (CIELAB) value does not exceed, the ΔE * (CIELAB) reference value being that which is shown in the CIE x, y diagram (chromaticity diagram) familiar to the person skilled in the art based on DIN 6175 for the The color of the third coating layer results and the following relationship applies:
n < 90 im mit ΔE* = 0,3 gekennzeichneten Bereich des CIE-x,y Diagramms, n < 50 im mit ΔE* = 0,5 gekennzeichneten Bereich des CIE-x,y-Diagramms, n < 40 im mit ΔE* = 0,7 gekennzeichneten Bereich des CIE-x,y Diagramms, n < 30 im mit ΔE* = 0,9 gekennzeichneten Bereich des CIE-x,y-Diagramms.n <90 in the region of the CIE-x, y diagram marked ΔE * = 0.3, n <50 in the region of the CIE-x, y diagram marked ΔE * = 0.5, n <40 in the area of the CIE-x, y diagram marked ΔE * = 0.7, n <30 in the area of the CIE-x, y diagram marked ΔE * = 0.9.
Als Klarlacküberzugsmittel für die Erzeugung der vierten und gegebenenfalls weiterer Überzugsschichten sind grundsätzlich alle üblichen Klarlacke oder transparent farbig oder farblos pigmentierten Uberzugsmittel geeignet. Dabei kann es sich um ein- oder mehrkomponentige Klarlacküberzugsmittel handeln. Sie können lösemittelfrei (flüssig oder als Pulverklarlack) sein, oder es kann sich um Systeme auf der Basis von Lösemitteln handeln oder es handelt sich um wasserverdünnbare Klarlacke, deren Bindemittelsysteme in geeigneter Weise, z.B. anionisch, kationisch oder nicht-ionisch, stabilisiert sind. Bei den wasserverdünnbaren Klarlacksystemen kann es sich um wasserlösliche oder in Wasser dispergierte Systeme, beispielsweise Emulsionssysteme oder Pulverslurry-Systeme handeln. Die Klarlacküberzugsmittel härten beim Einbrennen unter Ausbildung kovalenter Bindungen infolge chemischer Vernetzung aus.In principle, all customary clear lacquers or transparent colored or colorless pigmented coating compositions are suitable as clear coating compositions for the production of the fourth and possibly further coating layers. These can be single-component or multi-component clear lacquer coating compositions. They can be solvent-free (liquid or as a powder clearcoat), or they can be systems based on solvents, or they can be water-dilutable clearcoats, the binder systems of which are suitable, e.g. anionic, cationic or non-ionic, are stabilized. The water-dilutable clear lacquer systems can be water-soluble or water-dispersed systems, for example emulsion systems or powder slurry systems. The clear lacquer coating agents harden when stoved to form covalent bonds as a result of chemical crosslinking.
Bei den im erfindungsgemäßen Verfahren verwendbaren Klarlacken handelt es sich um übliche Klarlacküberzugsmittel, die ein oder mehrere übliche Basisharze als filmbildende Bindemittel enthalten. Sie können, falls die Basisharze nicht selbstvernetzend sind, gegebenenfalls auch Vernetzer enthalten. Sowohl die Basisharzkomponente als auch die Vernetzerkomponente unterliegen keinerlei Beschränkung. Als filmbildende Bindemittel (Basisharze) können beispielsweise Polyester-, Polyurethan- und/oder (Meth)acryl-Copolymer-Harze verwendet werden. Die Auswahl der gegebenenfalls enthaltenen Vernetzer ist unkritisch, sie richtet sich nach der Funktionalität der Basisharze, d.h. die Vernetzer werden so ausgewählt, daß sie eine zur Funktionalität der Basisharze komplementäre, reaktive Funktionalität aufweisen. Beispiele für solche komplementäre Funktionalitäten zwischen Basisharz und Vernetzer sind: Carboxyl/Epoxid, an Kohlenstoff oder Silizium direkt gebundenesThe clearcoats which can be used in the process according to the invention are customary clearcoat coating compositions which contain one or more customary base resins as film-forming binders. If the base resins are not self-crosslinking, they may also contain crosslinking agents. Both the base resin component and the crosslinker component are not subject to any limitation. Polyester, polyurethane and / or (meth) acrylic copolymer resins, for example, can be used as film-forming binders (base resins). The selection of the crosslinking agents that may be present is not critical; it depends on the functionality of the base resins, i.e. the crosslinkers are selected so that they have a reactive functionality which is complementary to the functionality of the base resins. Examples of such complementary functionalities between base resin and crosslinker are: carboxyl / epoxy, something directly bound to carbon or silicon
Hydroxyl/Methylolether, an Kohlenstoff oder Silizium direkt gebundenes Hydroxyl/Freies Isocyanat, an Kohlenstoff oder Silizium direkt gebundenes Hydroxyl/Blockiertes Isocyanat, (Meth)acryloyl/CH-acide Gruppe. In diesem Zusammenhang sind unter direkt an Silizium gebundenen Hydroxylgruppen auch latente Silanolgruppen, wie z.B. Alkoxysilangruppen, zu verstehen. Sofern miteinander verträglich, können auch mehrere solcher komplementären Funktionalitäten in einem Klarlack nebeneinander vorliegen. Die gegebenenfalls in den Klarlacken verwendeten Vernetzer können einzeln oder im Gemisch vorliegen. 5Hydroxyl / methylol ether, hydroxyl / free isocyanate bonded directly to carbon or silicon, hydroxyl / blocked isocyanate bonded directly to carbon or silicon, (meth) acryloyl / CH-acidic group. In this context, hydroxyl groups bonded directly to silicon also include latent silanol groups, such as, for example Alkoxysilane groups to understand. If compatible with one another, several such complementary functionalities can also be present side by side in a clear lacquer. The crosslinking agents optionally used in the clear lacquers can be present individually or in a mixture. 5
Neben den chemisch vernetzenden Bindemitteln sowie gegebenenfalls Vernetzern können die im erfindungsgemäßen Verfahren einsetzbaren Klarlacke lackübliche Additive, wie z.B. Katalysatoren, Verlaufsmittel, Farbstoffe, insbesondere jedoch Rheologiesteuerer, wie Mikrogele, NAD 0 (= non-aqueous-dispersions), disubstituierte Harnstoffe ("sagging control agents"), sowie Lichtschutzmittel gegebenenfalls in Kombination mit Antioxidantien enthalten.In addition to the chemically crosslinking binders and, if appropriate, crosslinking agents, the clear lacquers which can be used in the process according to the invention can contain conventional lacquer additives, such as Catalysts, leveling agents, dyes, but especially rheology control agents such as microgels, NAD 0 (= non-aqueous dispersions), disubstituted ureas ("sagging control agents"), and light stabilizers, if appropriate in combination with antioxidants.
Beispiele für ein- (1K) und zweikomponentige (2K) nicht-wäßrige 5 Klarlacksysteme, die im erfindungsgemäßen Verfahren als Klarlack eingesetzt werden können, findet man in DE-A-38 26 693, DE-A-40 17 075, DE-A-41 24 167, DE-A-41 33704, DE-A-42 04 518, DE-A-42 04 611, EP-A-0 257 513, EP-A-0408858, EP-A-0 523 267, EP-A-0 557 822, W0-92 11 327.Examples of one (1K) and two-component (2K) non-aqueous clearcoat systems which can be used as clearcoat in the process according to the invention can be found in DE-A-38 26 693, DE-A-40 17 075, DE-A -41 24 167, DE-A-41 33704, DE-A-42 04 518, DE-A-42 04 611, EP-A-0 257 513, EP-A-0408858, EP-A-0 523 267, EP-A-0 557 822, W0-92 11 327.
0 Beispiele für ein- (1K) oder zweikomponentige (2K)0 Examples for one (1K) or two-component (2K)
Wasserklarlacksysteme, die im erfindungsgemäßen Verfahren als Klarlack eingesetzt werden_ können, findet man in DE-A-39 10829, DE-A-4009 931, DE-A-4009932, DE-A-41 01 696, DE-A-41 32 430, DE-A-41 34 290, DE-A-42 03510, EP-A-0365098, EP-A-0365775, EP-A-0496079, EP-A-0546640.Water clearcoat systems which can be used as clearcoat in the process according to the invention can be found in DE-A-39 10829, DE-A-4009 931, DE-A-4009932, DE-A-41 01 696, DE-A-41 32 430 , DE-A-41 34 290, DE-A-42 03510, EP-A-0365098, EP-A-0365775, EP-A-0496079, EP-A-0546640.
'5'5
Beispiele für die im erfindungsgemäßen Verfahren zur Erzeugung der transparenten Überzugsschicht bevorzugt eingesetzten Pulverklarlacksysteme findet man in EP-A-0 509 392, EP-A-0 509 393, EP- A-0 522648, EP-A-0 544 206, EP-A-0 555 705, DE-A-42 22 194, DE-A-42 27 0 580.Examples of the powder clearcoat systems preferably used in the process according to the invention for producing the transparent coating layer can be found in EP-A-0 509 392, EP-A-0 509 393, EP-A-0 522648, EP-A-0 544 206, EP- A-0 555 705, DE-A-42 22 194, DE-A-42 27 0 580.
Der transparente Überzug kann in einer einzigen Schicht oder in Form von mehreren Schichten aus dem gleichen oder aus mehreren verschiedenen transparenten Überzugsmitteln aufgebracht werden. Zweckmäßig wird die 5 transparente Überzugsschicht jedoch als vierte Schicht aus nur einem Klarlacküberzugsmittel aufgebracht. Bevorzugt werden dabei solche Klarlacküberzugsmittel verwendet, die eine möglichst geringe Ablaufneigung besitzen, beispielsweise festkörperreiche Klarlacke mit entsprechend eingestelltem rheologischen Verhalten. Besonders bevorzugt sind Pulverklarlacke.The transparent coating can be applied in a single layer or in the form of several layers from the same or from several different transparent coating agents. However, the 5 transparent coating layer is expediently applied as a fourth layer comprising only one clear lacquer coating agent. Clear coating compositions which are as low as possible are preferably used Have a tendency to run off, for example, high-solids clear lacquers with a correspondingly adjusted rheological behavior. Powder clearcoats are particularly preferred.
Als Substrat für das erfindungsgemäße Verfahren sind elektrisch leitfähige Materialien, wie beispielsweise Metalle geeignet. Insbesondere geeignet sind z.B. Automobilkarossen oder Teile davon, sie können aus vorbehandeltem oder unvorbehandeltem Metall oder elektrisch leitendem oder mit einer elektrisch leitfähigen Schicht versehenen Kunststoff bestehen. Auf diese Substrate wird die erste Überzugsschicht aus dem wäßrigen Uberzugsmittel (I) elektrophoretisch in üblicher Weise in einer Trockenschichtdicke von beispielsweise 5 bis 15 μm abgeschieden und beispielsweise bei Temperaturen zwischen 130 und 180°C eingebrannt.Electrically conductive materials such as metals are suitable as the substrate for the method according to the invention. For example, automobile bodies or parts thereof are particularly suitable; they can be made of pretreated or untreated metal or electrically conductive or provided with an electrically conductive layer. The first coating layer of the aqueous coating agent (I) is deposited electrophoretically on these substrates in a customary manner in a dry layer thickness of, for example, 5 to 15 μm and, for example, baked at temperatures between 130 and 180 ° C.
Auf das so erhaltene mit einer einen spezifischen Widerstand von insbesondere 103 bis 10s Ohm.cm aufweisenden ETL-Schicht versehene Substrat wird die zweite Überzugsschicht aus einem zweiten von (I) verschiedenen elektrophoretisch abscheidbaren Uberzugsmittel (II) in einer Trockenschichtdicke von beispielsweise 5 bis 35 μm, bevorzugt zwischen 10 bis 25 μm, aufgetragen und ebenfalls beispielsweise bei Temperaturen zwischen 130 und 180°C eingebrannt. Die zweite Überzugsschicht besitzt im allgemeinen praktisch keine elektrische Leitfähigkeit, d.h. sie weist im eingebrannten Zustand einen spezifischen Widerstand von im allgemeinen über 109 Ohm.cm auf.The second coating layer made of a second coating agent (II) different from (I) different from (I) and having a dry layer thickness of, for example, from 5 to 10 μm is coated on the substrate thus obtained, which has a specific resistance of 10 3 to 10 s ohm.cm. 35 μm, preferably between 10 to 25 μm, applied and likewise baked, for example, at temperatures between 130 and 180 ° C. The second coating layer generally has practically no electrical conductivity, ie it has a specific resistance of more than 10 9 ohm.cm in the baked state.
Die durch Elektrotauchlackierung aus dem Uberzugsmittel (I) erhaltene Beschichtung dient insbesondere der Schutzwirkung gegen chemischen und korrosiven Angriff, so daß es vorteilhaft ist, möglichst die gesamte Oberfläche eines dreidimensionalen Substrats, beispielsweise einer Karosserie zu beschichten.The coating obtained by electrodeposition from the coating agent (I) serves in particular to protect against chemical and corrosive attack, so that it is advantageous to coat the entire surface of a three-dimensional substrate, for example a body, if possible.
Die durch Elektrotauchlackierung aus dem Uberzugsmittel (II) erhaltene und im eingebrannten Zustand elektrisch isolierende Beschichtung kann sich, aber muß sich nicht ganzflächig über das dreidimensionaleThe coating obtained by electrodeposition from the coating agent (II) and electrically insulating in the baked state can, but does not have to cover the entire three-dimensional area
Substrat erstrecken; ene mögliche Doppelbeschichtung ist entsprechend beispielsweise eine ganzflächige erste Beschichtung durch Elektrotauchlackierung aus dem Uberzugsmittel (I) und eine Beschichtung aus dem Uberzugsmittel (II) durch Elektrotauchlackierung beispielsweise im wesentlichen nur an äußeren Bereichen, insbesondere sichtbaren Flächen eines dreidimensionalen Substrats, d.h. beispielsweise nicht in 5 engen Hohlräumen einer Karosserie.Stretch substrate; A possible double coating is, for example, a full-surface first coating Electrocoating from the coating agent (I) and a coating from the coating agent (II) by electrocoating, for example, essentially only on outer areas, in particular visible surfaces of a three-dimensional substrate, ie for example not in 5 narrow cavities of a body.
Anschließend erfolgt der Spritzauftrag der dritten Überzugsschicht aus dem färb- und/oder effektgebenden Basislack in einer vom Farbton abhängigen Trockenschichtdicke von 10 bis 25 μm, beispielsweise durch 10 Druckluftspritzen, Airless-Spritzen oder ESTA-Hochrotationsspritzen.The third coating layer is then sprayed from the color and / or effect basecoat in a dry layer thickness of 10 to 25 μm, depending on the color, for example by 10 compressed air sprayers, airless sprayers or ESTA high-speed rotary sprayers.
Im Anschluß an die Applikation der dritten färb- und/oder effektgebenden Überzugsschicht erfolgt nach einer kurzen Ablüftphase, z.B. bei 20 bis 80°C, der Auftrag des Klarlacks im Naß-in-Naß-Following the application of the third coloring and / or effect coating layer, after a short flash-off phase, e.g. at 20 to 80 ° C, the application of the clear coat in wet-on-wet
15 Verfahren. Die vierte Überzugsschicht wird aus einem üblichen flüssigen oder Pulverklarlack (in diesem Fall handelt es sich um eine Trocken-in- Naß-Applikation) aufgebracht und gemeinsam mit der dritten Überzugsschicht beispielsweise bei Temperaturen von 80 bis 160°C eingebrannt. Gegebenenfalls können weitere Klarlackschichten aus dem15 procedures. The fourth coating layer is applied from a customary liquid or powder clearcoat (in this case it is a dry-in-wet application) and baked together with the third coating layer, for example at temperatures from 80 to 160 ° C. If necessary, further layers of clear lacquer from the
20 gleichen oder davon verschiedenen Klarlacküberzugsmitteln aufgebracht werden. Erfindungsgemäß wird so gearbeitet, daß die Schichtdicke der transparenten Überzugsschicht oder die Gesamtschichtdicke der transparenten Überzugsschichten zwischen 40 und 80 μm, bevorzugt zwischen 50 und 60 μm beträgt.20 of the same or different clear coat coatings can be applied. The process according to the invention is such that the layer thickness of the transparent coating layer or the total layer thickness of the transparent coating layers is between 40 and 80 μm, preferably between 50 and 60 μm.
^5^ 5
Es ist auch möglich, wenn auch nicht bevorzugt, die färb- und/oder effektgebende Basislackschicht im Naß-in-Naß-Verfahren auf die nicht eingebrannte zweite Überzugsschicht aufzubringen und die beiden Überzugsschichten gemeinsam vor oder nach Applikation der transparentenIt is also possible, if not preferred, to apply the coloring and / or effect basecoat layer by wet-on-wet method to the non-baked second coating layer and the two coating layers together before or after application of the transparent
30 Überzugsschicht oder Überzugsschichten einzubrennen.30 burn-in coating layer or layers.
Gute Ergebnisse können auch erhalten werden, wenn auf die aus den Überzugsmitteln (I) und (II) erstellte Zweischichtlackierung anstelle des Basislack/Klarlack-Aufbaus eine Überzugsschicht aus einem 35 pigmentierten Pulverdecklack in einer Schichtdicke von 40 bis 90 μm, bevorzugt von 50 bis 80 μm aufgetragen und eingebrannt wird, wobei der Auftrag von einer oder mehreren Klarlackschichten folgen kann. Dabei liegt dem Pulverdecklack ein an sich bekanntes Pulverklarlack- Bindemittel/Vernetzer-System zugrunde, wie beispielsweise vorstehend schon im Zusammenhang mit den Pulverklarlacken beschrieben. Der Pulverdecklack enthält färb- und/oder effektgebende Pigmente, wie sie beispielsweise vorstehend für die Basislacke beschrieben sind.Good results can also be obtained if, instead of the basecoat / clearcoat structure, a coating layer of 35 pigmented powder topcoat in a layer thickness of 40 to 90 μm, preferably 50 to 80, is applied to the two-layer coating created from the coating compositions (I) and (II) μm is applied and baked, whereby the application can follow from one or more layers of clear lacquer. there the powder topcoat is based on a powder clearcoat binder / crosslinking system known per se, as described above, for example, in connection with the powder clearcoats. The powder topcoat contains coloring and / or effect pigments, such as those described above for the basecoats.
Das erfindungsgemäße Verfahren erlaubt die Herstellung von Mehrschichtlackierungen, insbesondere von Kraftfahrzeuglackierungen mit im Vergleich zum Stand der Technik vergleichbarem Gesamteigenschaftsniveau sowie verbessertem Glanz und Decklackstand. Es hat sich gezeigt, daß hervorragende Eigenschaften durch die erfindungsgemäße Verfahrensweise erzielt werden, obwohl diese den Wegfall von üblichen Spritzfüllerschichten ermöglicht. Trotz hoher Schichtdicke beim Klarlackauftrag sind die Gesamtschichtdicken der nach dem erfindungsgemäßen Verfahren hergestellten Mehrschichtlackierungen sehr gering. Sie liegen insbesondere bei 90 bis 130 μm. The method according to the invention allows the production of multi-layer coatings, in particular automotive coatings with an overall level of properties comparable to that of the prior art and an improved gloss and topcoat level. It has been shown that excellent properties are achieved by the procedure according to the invention, although this makes it possible to dispense with conventional spray filler layers. Despite the high layer thickness when applying the clear lacquer, the total layer thicknesses of the multi-layer lacquers produced by the process according to the invention are very small. They are in particular 90 to 130 μm.

Claims

PATFNTANSPRÜCHE PATFNT CLAIMS
1. Verfahren zur Herstellung einer Mehrschichtlackierung, bei dem auf einem elektrisch leitfähigen Substrat eine erste Überzugsschicht aus einem elektrophoretisch abscheidbaren wäßrigen Uberzugsmittel (I) elektrophoretisch aufgetragen und anschließend eingebrannt wird, worauf weitere Überzugsschichten aufgebracht werden, dadurch gekennzeichnet, daß man als Uberzugsmittel (I) ein solches verwendet, das zu einer im eingebrannten Zustand elektrisch leitfähigen Überzugsschicht führt, worauf nach dem Einbrennen der ersten Überzugsschicht eine elektrisch isolierende zweite Überzugsschicht aus einem von (I) verschiedenen elektrophoretisch abscheidbaren wäßrigen Uberzugsmittel (II) elektrophoretisch abgeschieden und eingebrannt wird, worauf als dritte Überzugsschicht eine Basislackschicht aus einem färb- und/oder effektgebenden Uberzugsmittel aufgetragen und mit einer vierten, transparenten Überzugsschicht aus einem Klarlacküberzugsmittel überlackiert und mit dieser gemeinsam eingebrannt wird, worauf gegebenenfalls eine oder mehrere weitere transparente Überzugsschichten aufgetragen werden, wobei die1. A process for producing a multilayer coating, in which a first coating layer composed of an electrophoretically separable aqueous coating composition (I) is applied electrophoretically on an electrically conductive substrate and then baked, whereupon further coating layers are applied, characterized in that the coating composition (I) uses one which leads to an electrically conductive coating layer in the baked state, whereupon after baking the first coating layer, an electrically insulating second coating layer is electrophoretically deposited and baked from an aqueous coating agent (II) different from (I), followed by third Coating layer applied a basecoat layer of a coloring and / or effect coating agent and overpainted with a fourth, transparent coating layer of a clear lacquer coating agent and together with this m is baked, whereupon one or more further transparent coating layers are applied, the
Gesamttrockenschichtdicke des Lackaufbaus bei 90 bis 130 μm und die Trockenschichtdicke der transparenten Überzugsschicht bzw. der transparenten Überzugsschichten bei 40 bis 80 μm liegt.The total dry layer thickness of the lacquer structure is 90 to 130 μm and the dry layer thickness of the transparent coating layer or the transparent coating layers is 40 to 80 μm.
2. Verfahren nach Anspruch 1, dadurch gekennzeichnet, daß es zur Lackierung von Kraftfahrzeugen oder Kraftfahrzeugteilen durchgeführt wird.2. The method according to claim 1, characterized in that it is carried out for painting motor vehicles or motor vehicle parts.
3. Verfahren nach Anspruch 1 oder 2, dadurch gekennzeichnet, daß zur Herstellung der zweiten Überzugsschicht ein Elektrotauchlack verwendet wird, der einen Farbton aufweist, der dem zur Erzeugung der dritten Überzugsschicht verwendeten Uberzugsmittel nahekommt oder gleich ist.3. The method according to claim 1 or 2, characterized in that an electro dip coating is used to produce the second coating layer, which has a color that comes close to the coating agent used to produce the third coating layer or is the same.
4. Verfahren nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, daß die Trockenschichtdicke der ersten Uberzugsschicht 5 bis 15 μm, die der zweiten Uberzugsschicht 5 bis 35 μm und die der dritten Uberzugsschicht 10 bis 25 μm beträgt.4. The method according to any one of the preceding claims, characterized in that the dry layer thickness of the first coating layer 5 to 15 microns, that of the second coating layer 5 to 35 microns and that of the third coating layer is 10 to 25 microns.
5. Verfahren nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, daß die Klarlackschicht oder die Klarlackschichten unter Verwendung eines Pulverlacks hergestellt werden. 5. The method according to any one of the preceding claims, characterized in that the clear lacquer layer or the clear lacquer layers are produced using a powder coating.
EP96919803A 1995-05-30 1996-05-24 Multi-coat painting process Expired - Lifetime EP0839073B1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DE19519665A DE19519665C1 (en) 1995-05-30 1995-05-30 Multi-coat lacquering process for vehicle or component
DE19519665 1995-05-30
PCT/EP1996/002234 WO1996038235A1 (en) 1995-05-30 1996-05-24 Multi-coat painting process

Publications (2)

Publication Number Publication Date
EP0839073A1 true EP0839073A1 (en) 1998-05-06
EP0839073B1 EP0839073B1 (en) 1999-09-22

Family

ID=7763138

Family Applications (1)

Application Number Title Priority Date Filing Date
EP96919803A Expired - Lifetime EP0839073B1 (en) 1995-05-30 1996-05-24 Multi-coat painting process

Country Status (11)

Country Link
US (1) US5882734A (en)
EP (1) EP0839073B1 (en)
JP (1) JPH11505767A (en)
KR (1) KR100394579B1 (en)
AT (1) ATE184814T1 (en)
BR (1) BR9608598A (en)
CA (1) CA2222803A1 (en)
DE (2) DE19519665C1 (en)
ES (1) ES2140864T3 (en)
WO (1) WO1996038235A1 (en)
ZA (1) ZA964394B (en)

Families Citing this family (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19525375A1 (en) * 1995-07-12 1997-01-16 Herberts Gmbh Coating agents, their use and process for the production of multilayer coatings
DE19643082C2 (en) * 1995-10-18 2003-10-30 Volkswagen Ag Process for the interior and exterior coating of a body with cavities
DE19633173C1 (en) * 1996-08-17 1997-10-02 Herberts Gmbh Multilayered lacquering, e.g. of vehicles
DE19648517A1 (en) * 1996-11-23 1998-06-04 Herberts & Co Gmbh Process for multi-layer painting
DE19733312A1 (en) 1997-08-01 1999-02-04 Herberts Gmbh Process for applying a protective and decorative layer composite
US6248225B1 (en) 1998-05-26 2001-06-19 Ppg Industries Ohio, Inc. Process for forming a two-coat electrodeposited composite coating the composite coating and chip resistant electrodeposited coating composition
US6423425B1 (en) 1998-05-26 2002-07-23 Ppg Industries Ohio, Inc. Article having a chip-resistant electrodeposited coating and a process for forming an electrodeposited coating
US20020056641A1 (en) * 1999-12-15 2002-05-16 December Timothy S. Cured multilayer coating providing improved edge corrosion resistance to a substrate and a method of making same
US6368719B1 (en) 2000-06-12 2002-04-09 E. I. Du Pont De Nemours And Company Process for preparing multi-layer coatings on automotive bodies or automotive body parts
US6676820B2 (en) 2001-03-02 2004-01-13 Ppg Industries Ohio, Inc. Process for electrocoating metal blanks and coiled metal substrates
US6508922B2 (en) 2001-05-10 2003-01-21 E. I. Du Pont De Nemours And Company Process for multi-layer coating
US20040118695A1 (en) * 2002-08-29 2004-06-24 Ding-Yu Chung Two-coat electrocoating process
US20050250415A1 (en) * 2004-04-23 2005-11-10 Barthold Mark J Toy and card package
US20050250416A1 (en) * 2004-04-23 2005-11-10 Barthold Mark J Toy and card package
US20060079150A1 (en) * 2004-10-08 2006-04-13 Miva Filoseta Toy for collecting and dispersing toy vehicles
US20060076735A1 (en) * 2004-10-08 2006-04-13 Nathan Proch Wheel having a translucent aspect
US20060079149A1 (en) * 2004-10-08 2006-04-13 Nathan Proch Cut-out logo display
US20060078684A1 (en) * 2004-10-08 2006-04-13 Neo Tian B Paint process for toys
US7959981B2 (en) * 2007-08-27 2011-06-14 Ppg Industries Ohio, Inc. Process for depositing multiple coatings layers on a substrate

Family Cites Families (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3674671A (en) * 1969-02-26 1972-07-04 Textron Inc Electrodeposition method and product
JPS5814266B2 (en) * 1975-12-19 1983-03-18 三井東圧化学株式会社 Metallic materials
JPS5951958A (en) * 1982-09-18 1984-03-26 Nippon Paint Co Ltd Cationic electrodeposition paint composition
DE3447257A1 (en) * 1984-12-22 1986-06-26 Basf Farben + Fasern Ag, 2000 Hamburg METHOD FOR THE MULTI-LAYER CATHODIC WET-IN-WET LACQUERING OF METALLICALLY CONDUCTIVE SUBSTRATES
US4755418A (en) * 1985-08-12 1988-07-05 Basf Corporation Nonyellowing cathodic electrocoat
DE3538792C1 (en) * 1985-10-31 1987-05-07 Basf Lacke & Farben Electrophoretically overcoatable coatings applied in the electrocoating process
JP2614468B2 (en) * 1987-11-26 1997-05-28 関西ペイント株式会社 Top coat finish method
US4911811A (en) * 1988-07-14 1990-03-27 The Stanley Works Method of making coated articles with metallic appearance
JPH0312263A (en) * 1989-06-12 1991-01-21 Nissan Motor Co Ltd Method for forming urushi like film
JP2802397B2 (en) * 1989-10-30 1998-09-24 神東塗料株式会社 Electrodeposited film forming composition and coating method
DE4005961A1 (en) * 1990-02-26 1991-08-29 Basf Lacke & Farben METHOD FOR PAINTING VEHICLE BODIES AND AQUEOUS PAINT
DE4011633A1 (en) * 1990-04-11 1991-10-17 Herberts Gmbh METHOD FOR PRODUCING MULTILAYER COATINGS
US5114756A (en) * 1990-04-27 1992-05-19 E. I. Du Pont De Nemours And Company Conductive epoxypolyamide coating composition
DE4134290A1 (en) * 1991-10-17 1993-09-23 Herberts Gmbh METHOD OF MULTILAYER LACQUERING
US5203975A (en) * 1991-10-29 1993-04-20 E. I. Du Pont De Nemours And Company Process for cathodic electrodeposition of a clear coating over a conductive paint layer
US5326596A (en) * 1991-12-19 1994-07-05 Kansai Paint Company, Ltd. Coating method
DE4215070A1 (en) * 1992-05-07 1993-11-11 Herberts Gmbh Process for the production of multi-layer coatings
DE4235778A1 (en) * 1992-10-23 1994-04-28 Herberts Gmbh Process for the production of multi-layer coatings
DE4331673A1 (en) * 1993-09-17 1995-05-11 Herberts Gmbh Process for the production of multi-layer coatings

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO9638235A1 *

Also Published As

Publication number Publication date
DE19519665C1 (en) 1996-09-05
ATE184814T1 (en) 1999-10-15
KR19990022090A (en) 1999-03-25
ES2140864T3 (en) 2000-03-01
WO1996038235A1 (en) 1996-12-05
CA2222803A1 (en) 1996-12-05
DE59603174D1 (en) 1999-10-28
BR9608598A (en) 1999-01-05
MX9709224A (en) 1998-03-31
KR100394579B1 (en) 2003-10-30
US5882734A (en) 1999-03-16
EP0839073B1 (en) 1999-09-22
ZA964394B (en) 1996-12-09
JPH11505767A (en) 1999-05-25

Similar Documents

Publication Publication Date Title
DE19512017C1 (en) Multi-layer lacquering for use in car industry
DE19606716C1 (en) Process for multi-layer painting
EP0828568B1 (en) Multi-coat painting process
DE19519665C1 (en) Multi-coat lacquering process for vehicle or component
EP0904160B1 (en) Process for producing multi-coat paints on electrically conductive substrates
WO1999006158A1 (en) Method for applying a protective and decorative layered composite
EP0952894B1 (en) Method for multi-layer painting
EP2393612A1 (en) Coating agent for corrosion-resistant coatings
DE19529394C2 (en) Process for the production of multi-layer coatings on metal substrates
DE19633173C1 (en) Multilayered lacquering, e.g. of vehicles
US6350359B1 (en) Process for coating three-dimensional electrically conductive substrates
DE3009715A1 (en) Primer filler binder - esp. for reverse process car lacquering, contains phosphoric- and/or phosphonic acid-modified epoxy! resin soln.
DE4422287A1 (en) Effect lacquering esp. for large area surfaces for pigment amt. redn.
DE4434584A1 (en) Preventing defects (e.g. craters) in coatings
MXPA97009224A (en) Laying process of multip layers
CZ376797A3 (en) Process for producing coating of several varnish layers

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 19971213

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE DE ES FR GB IT NL PT SE

AX Request for extension of the european patent

Free format text: SI PAYMENT 971213

17Q First examination report despatched

Effective date: 19980714

GRAG Despatch of communication of intention to grant

Free format text: ORIGINAL CODE: EPIDOS AGRA

GRAG Despatch of communication of intention to grant

Free format text: ORIGINAL CODE: EPIDOS AGRA

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): AT BE DE ES FR GB IT NL PT SE

AX Request for extension of the european patent

Free format text: SI PAYMENT 19971213

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SE

Free format text: THE PATENT HAS BEEN ANNULLED BY A DECISION OF A NATIONAL AUTHORITY

Effective date: 19990922

Ref country code: NL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 19990922

Ref country code: GB

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 19990922

REF Corresponds to:

Ref document number: 184814

Country of ref document: AT

Date of ref document: 19991015

Kind code of ref document: T

REF Corresponds to:

Ref document number: 59603174

Country of ref document: DE

Date of ref document: 19991028

ET Fr: translation filed
ITF It: translation for a ep patent filed

Owner name: BIANCHETTI - BRACCO - MINOJA S.R.L.

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: PT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 19991222

NLV1 Nl: lapsed or annulled due to failure to fulfill the requirements of art. 29p and 29m of the patents act
REG Reference to a national code

Ref country code: ES

Ref legal event code: FG2A

Ref document number: 2140864

Country of ref document: ES

Kind code of ref document: T3

GBV Gb: ep patent (uk) treated as always having been void in accordance with gb section 77(7)/1977 [no translation filed]

Effective date: 19990922

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: AT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20000524

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: BE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20000531

PLBQ Unpublished change to opponent data

Free format text: ORIGINAL CODE: EPIDOS OPPO

PLBI Opposition filed

Free format text: ORIGINAL CODE: 0009260

PLBF Reply of patent proprietor to notice(s) of opposition

Free format text: ORIGINAL CODE: EPIDOS OBSO

26 Opposition filed

Opponent name: PPG INDUSTRIES, INC.

Effective date: 20000615

PLBF Reply of patent proprietor to notice(s) of opposition

Free format text: ORIGINAL CODE: EPIDOS OBSO

BERE Be: lapsed

Owner name: HERBERTS G.M.B.H.

Effective date: 20000531

RAP2 Party data changed (patent owner data changed or rights of a patent transferred)

Owner name: E.I. DU PONT DE NEMOURS AND COMPANY

APBP Date of receipt of notice of appeal recorded

Free format text: ORIGINAL CODE: EPIDOSNNOA2O

APBQ Date of receipt of statement of grounds of appeal recorded

Free format text: ORIGINAL CODE: EPIDOSNNOA3O

APAA Appeal reference recorded

Free format text: ORIGINAL CODE: EPIDOS REFN

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES;WARNING: LAPSES OF ITALIAN PATENTS WITH EFFECTIVE DATE BEFORE 2007 MAY HAVE OCCURRED AT ANY TIME BEFORE 2007. THE CORRECT EFFECTIVE DATE MAY BE DIFFERENT FROM THE ONE RECORDED.

Effective date: 20050524

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: ES

Payment date: 20050530

Year of fee payment: 10

APAH Appeal reference modified

Free format text: ORIGINAL CODE: EPIDOSCREFNO

APBU Appeal procedure closed

Free format text: ORIGINAL CODE: EPIDOSNNOA9O

PLCK Communication despatched that opposition was rejected

Free format text: ORIGINAL CODE: EPIDOSNREJ1

PLBN Opposition rejected

Free format text: ORIGINAL CODE: 0009273

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: OPPOSITION REJECTED

27O Opposition rejected

Effective date: 20060203

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 20060523

Year of fee payment: 11

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: ES

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20060525

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 20070517

Year of fee payment: 12

REG Reference to a national code

Ref country code: ES

Ref legal event code: FD2A

Effective date: 20060525

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

Effective date: 20080131

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20070531

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20081202