EP1268088B1 - Method for removing minor lacquer imperfections - Google Patents

Abstract

The invention relates to a method for repairing lacquer imperfections (20), especially minor lacquer imperfections of body paints. The lacquer (12, 14, 16, 18) is removed in the imperfect area in a very small spot down to a predetermined depth, preferably in a crateriform shape and the imperfect spot is then concealed by repainting it so that it is almost invisible to the human eye. The lacquer is preferably removed by means of a vacuum sand blasting method in an area that extends beyond the imperfect spot (20) only by maximally few millimeters and down to a coloring base lacquer layer (16) below the clear coat (18) or a filler layer (14) present below said base lacquer layer. Repainting comprises preferably applying a color lacquer layer (16a) in the sand-blasted area, filling the dent in the lacquer with a clear coat (18a), spraying the imperfect spot with a color lacquer (16b) and applying a protective clear coat layer (18b). The lacquer used as the color lacquer layer (16a, 16b) is preferably the original base lacquer (16) surrounding the spot to be repaired or at least a lacquer from the same lacquer batch that is put aside and stored when the original paint is applied. Before the lacquer layer (12, 14, 16, 18) is removed and/or before repainting, the lacquer area surrounding the imperfect spot is preferably covered by a protective film that leaves free only the imperfect spot and the area directly surrounding it. The invention also relates to a specific method for filling and/or spraying corresponding lacquer repair spots.

Description

The present invention relates to a method for repairing Lackierungsfehlstellen, in particular small Lackierungsfehlstellen an automotive painting, wherein the paint is removed in the defect area so deep that the Lackierungsfehlstelle is at least partially removed, and a resulting from the removal recess is repainted. It also relates to methods for filling corresponding paint repair sites or paint wells, especially in effect coatings, with a suitable repair paint and a misting process for already filled with paint paint repair sites with a repair job laminating paint. The invention further relates to a special painting method, in particular for automobiles, for providing an optimally suitable colored lacquer for carrying out these methods. Finally, the invention relates to a protective film which can be used for the method for covering the paint area surrounding the defect.

When painting automobiles, small paint defects or painting defects occur regularly, which are clearly visible and therefore have to be eliminated almost invisible to the human eye. These imperfections can include both superficial defects in an outer protective clear coat that occur as paint bumps or paint bumps and are removed by abrading and then polishing the buffing sites, as well as defects visible below and / or within the clear coat that are clearly visible through the clear coat and can not be eliminated by a simple leveling of the clearcoat. Conventionally, such defects are therefore first abraded over a large area, usually each one about hand-sized grinding point arises, which is then extensively repainted over a large area towards the edge. The repainting must take place over such a large area that the eye of an observer can no longer dissolve the transitions to the original finish surrounding the defect. In this so-called "spot repair method", the affected vehicle is covered or masked during repainting as protection for the rest of the paint, except for the actual defect largely or completely with films or the like, so that a corresponding flaw repair is extremely laborious and expensive. Another, no less expensive The method consists of repainting the entire affected component by means of a so-called full-scale coating.

WO 93/10912 further discloses a process for producing a readily renewable final coating at a desired location of a surface of an article. The method consists of several steps wherein firstly a first agent is applied to the desired location on the surface of the article which acts against any impurities present and at the same time provides a layer as a type of primer. Secondly, a paint is prepared which agrees with the final color of the final coating of the article, thirdly adding a first and second additive to that paint, with the aim of reacting with the primer layer on the one hand and the final coating of the paint on the other Subject is faulty, liable and on the other hand has no liability in areas of a still flawless final coating. In a fourth step, a layer of the paint produced in the third step is applied to the desired location of the surface of the article, in particular sprayed, and finally applied a hardening transparent protective layer over the sprayed paint layer and the surrounding surface in a manner which is effective Adjustment of the applied, preferably sprayed ink layer compared to the original end coating of the article delivers. The thermosetting protective layer and the sprayed paint layer can be removed from the surface of the article at a later time without causing damage to the original finish. The disadvantage, however, is that this method does not allow completely invisible removal at the desired locations of the surface.

The object of the present invention is to provide a less labor-intensive, simpler, faster and cheaper generic method for inconspicuous and almost invisible to the human eye elimination or lamination of corresponding Lackierungsfehlstellen.

According to the invention this object is achieved by a method having the features mentioned in claim 1.

The repainting of the flaw area comprises according to the invention a filling of the paint well produced with a refinish, that is the application of at least one pigmented refinish layer in the defect area, a fogging (lamination) of the defect area with a color coat and a subsequent application of a clearcoat. In this case, the refinish can be particularly advantageous either as a mixture of color-giving lacquer and clear lacquer or applied as successively applied color and clear lacquer layers. It should be understood here by a colorant lacquer or color lacquer a lacquer containing color pigments and optionally effect pigments. Due to the fact that, in both cases, the paint component in the refinish is thinned by the clear coat or by the clear coat, a repair point which corresponds more closely to the original original finish will be achieved, as will be explained in more detail below. As a color coat for both the refinish and for the fogging is preferably colored paint surrounding the repair site original paint or a lake of the same paint batch used. As a clearcoat for the refinish and / or the final clearcoat film, light-crosslinked so-called UV clearcoat materials have proven to be particularly useful because of their desired good shrinkage properties. For the application of the individual paint layers, a precision spray device is preferably used in this case, the defect area being cleaned beforehand by means of an isopropanol / water mixture. The flaw area can also be ground and / or polished between the individual operations, in particular before and / or after the misting and / or the application of a clearcoat film.

Preferably, it is provided that the coating is removed in a region whose diameter corresponds to not more than a 10-fold, according to a special embodiment, at most a 5-fold diameter of the Lackierungsfehlstelle. The paintwork is therefore only very small area or even almost selectively removed in the defect area. The removal takes place in each case only a maximum of a few millimeters beyond the defect, so that the Abtragungs- or processing area compared to conventional methods kept extremely small and after appropriate repainting in the manner described below in detail according to the invention for the human eye practically no longer is visible. The diameter of the ablation region is preferably only about 0.5 to 20 mm, but in particular about 0.6 to 10 mm. Particularly good results are obtained with diameters between about 0.7 and 4 mm, but especially between about 0.8 and 2 mm.

The coating is preferably removed down to a colorless basecoat layer or coating layer below it under a protective clearcoat layer, which in the case of a conventional paint finish of an automotive finish corresponds to a removal depth of approximately 55 to 75 μm. Even with deeper coating defects or inclusions into the range of a below the filler layer and serving as corrosion protection catophoretic dip or KTL layer the imperfections can be concealed by a repair according to the invention of the filler, base and / or clear coat virtually invisible. Although the coating can be removed in such a case, even in the cathodic fluid layer or even down to the underlying sheet, but this may possibly have some problems, since the filler color usually deviates from the color of the cathodic fluid layer. If the repair is performed on an original filler substrate in the area of the filler or base coat, any difficulties in the subsequent color restoration can be avoided. In addition, in this approach, the KTL layer or corrosion protection layer remains intact, which would otherwise also repair or rebuild to avoid any corrosion problems, which would be associated with at least one additional process step, which would lead to a longer repair time and higher repair costs.

As a result of the removal of the coating, a crater-shaped depression with an edge steepness of approximately 30 to 95 °, but in particular of approximately 60 to 80 °, is preferably produced. However, it is also possible to choose other values for the slope steepness if necessary; However, if the angle of inclination is too great or too small, any problems with the removal of the coating and / or the later filling and laminating of the crater produced can occur.

The painting in the defect area is preferably removed by means of a boring, milling or grinding method, a blasting method or another suitable material removal method, for example a laser method. According to a particularly advantageous method, a sandblasting method is used in which also the removal process, that is the removal rate, the Abtragungstiefe and the shape or the edge steepness of the resulting crater-shaped depression, on the blasting agent and / or the blasting agent and / or the blasting agent speed and / or the particle size and / or the jet time is controlled. Has proven particularly useful is a vacuum sand blasting method, in which a negative pressure is used not only for sucking the blasting agent used over an acceleration section, but also for sucking the blasting agent and the removed paint particles, so that any damage to the area surrounding the flaw paint by flying paint - Are reliably prevented or sand particles.

Before ablating, grinding, polishing and / or applying a lacquer layer, but especially before the removal of the flaw area, the will Lack area surrounding lacquer area preferably covered by a protective film with a merely the flaw area and its immediate environment exposed opening. The actual working area during the subsequent ablation, abrading, repainting and / or polishing processes, in particular the diameter of the ablation area, is preferably determined by the size and shape of the opening of the protective film. The protective film also has the task to specifically protect the further environment of the defect from disturbing influences by the processing, in particular from paint mist and mechanical damage. Due to the invention small-scale operation and the use of precision instruments for removing and painting only an extremely small film size is required. The conventional large-scale complex masking of the paint repair site is eliminated. Disturbing paint defects can thus be removed over a very small area or even at specific points and kept extremely inconspicuous and almost invisible to the human eye. Corresponding protective films are also suitable for curved surfaces and thus can be used without difficulty in the automotive industry. After completion of the painting defect or possibly also after one of the intermediate steps required for this, in particular before the misting, the preferably self-adhesive or self-adhesive protective film is simply removed without residue from the paint layer and disposed of.

The diameter of the centrally arranged in the protective film and substantially circular opening is chosen appropriate for the individual Lackierungswehlstellen depending on the defect size and is typically 0.5 to 4.0 mm. Particularly good, ie virtually invisible repair results can be achieved with a protective film opening of 0.8 to 2.0 mm.

The protective film may for example be square with an edge length of between about 25 × 25 mm ² and about 100 × 100 mm ² , but in particular between about 40 × 40 mm ² and about 60 × 60 mm ² . However, other configurations, such as circular protective films with corresponding diameters, conceivable.

The protective film is provided in a preferred embodiment with a mark for identifying the position of the opening, advantageously with cross-shaped marking lines or the like in order to position paint defects easier and better in the center of the recessed area can. In addition, the protective film according to the invention is preferably colored and / or transparent, the color of the film deviating from the paint surrounding the repair site is selectable so that it is simultaneously usable as Lackfehlermarkierung. Due to the low film thickness, the protective film is preferably applied to a carrier device and sorted delivered to different opening diameters and colors ready to go.

The application of the protective film on the paint is greatly facilitated by using a self-adhesive or self-adhesive film. The material of the protective film and any adhesion-promoting coating should meet various requirements. Thus, after use, the film should be able to be removed from the paint residue-free and easily, in order to avoid further post-treatment steps. On the other hand, a resistance of the film material should be designed so that the film mechanical loads, for example, the sandblasting process, which typically lasts for 50 seconds at 20 mbar vacuum withstand, without perforating. At the same time, the adhesion of the film must be sufficient to prevent partial detachment. Finally, neither film nor adhesion-promoting coating should be soluble in a varnish or solvent used for the repainting.

For better handling, the protective films are preferably provided with a gripping device or a so-called "catcher", which may be designed, for example, as a one-sided or multi-sided, non-self-adhesive or adhesive edge reinforcement. Again, however, other embodiments are conceivable.

The repair of the defect is all the more inconspicuous, the better a color impression of the repair site coincides with the surrounding original finish. The color impression can be characterized colorimetrically by the shade determined by its wavelength, the color saturation and the brightness. As already explained, in order to hit the color tone, as far as possible the same color coat of the original finish is used for the repair paint and the overspray paint. The color saturation is determined by the totality of the color pigments superposed in the individual coloring layers or, in the case of effect lacquers, also by effect pigments. In order to imitate the color impression of the original paint as closely as possible, therefore, the refinish applied in the depression and the colorant sprayed on it is adjusted such that the sum of the color and / or effect pigments of the refinish coat applied in the paint recess and the overblown dye coat 85 to 115%, preferably 90 to 110%, equal to the sum of the original paintwork surrounding the repair site. In the optimal case, the number of pigments differs by a maximum of ± 3% from the original finish. The sum of the pigments in each case refers to one perpendicular to a paint surface extending axis, that is on the total depth of paint. It is further provided that a proportion of color pigments and / or effect pigments in the applied in the paint recess repair paint is such that the sum of the color and / or effect pigments of the repair paint layer 50 to 95%, preferably 65 to 92%, the sum of color and / or effect pigments of the color coat layer of the original finish corresponds. Even better results can be achieved with a refinish layer containing 75 to 90% of the pigments of the original finish. The stated proportions can be adjusted by appropriate proportions of the colored lacquer of the repair lacquer layer or by a corresponding dilution with clear lacquer. Overall, it is important that in any case the sum of the pigments of the repair lacquer layer is lower than in the original lacquer layer, in order to supplement the lack of saturation by an appropriate design of the paint layer which takes over the repair site. The latter is achieved by a suitable choice of a layer thickness of the color coat layer. Preferably, an at least the same bright refinish as the original finish is applied, the color impression is corrected later by the subsequent misting, since the color correction of a too dark repair paint by spraying is subsequently hardly possible.

A particular difficulty in the repair of small paint defects is given by a spatial orientation of effect pigments in so-called effect paints. Due to a two-dimensional platelet or rod-like shape of conventional effect pigments, these preferably align parallel to the substrate surface and to one another. In the surface area of the lacquer layer, the effect pigments also tend to have a surface-parallel alignment. As a result, the effect pigments in extensive paint surfaces therefore assume a largely ordered alignment, which essentially determines the visual impression and varies the reflectance as a function of a viewing angle. Due to the small layer thickness of the repair lacquer layer, the nonplanar surface and the small repair lacquer volume, the repair of small lacquer defects leads to an alignment of the effect pigments deviating from the surrounding lacquer finish and an undesired optical conspicuity of the repair site. According to a particularly advantageous method for filling a lacquer recess or a lacquer repair site in the case of effect lacquers, it is therefore provided that at least 80%, preferably at least 90%, of the effect pigments of the repair lacquer layer applied in the recess align substantially parallel to the effect pigments of an original finish surrounding the repair site that is, parallel to the paint surface. It is particularly preferred that one through the effect pigments of the repair paint layer formed main reflection plane by not more than 10 °, in particular by more than 5 °, deviates from a main reflection plane of the effect pigments of the original finish. This can be achieved with a method in which a surface tension of the effect pigment-containing repair paint, in particular by suitable selection of the solvent is adjusted such that the refinish after curing forms a substantially planar surface, with a maximum height deviation with respect to the surrounding paint level at most 10 microns is. Even more advantageously, the height deviation is at most 5 μm, in particular at most 1 μm. In this way it is avoided that caused by concave or convex surface distortions in the repair area area pigment alignments that differ from the parallel orientation in the environment.

In a further advantageous embodiment of the method, an effect pigment-containing refinish is applied, the reflectance of which is independent of a viewing angle. This can be achieved, for example, by using effect pigments for the refinish paint, which have a three-dimensional design instead of the usual rod-shaped or platelet-shaped design, in which a ratio of dimensions of two dimensions is 0.2 to 5 in each case. This may in particular be a tetrahedral, cubic, octahedral or another substantially uniform geometry or a spherical design. Such pigments show no or only a slight tendency to align and therefore have at least largely direction-independent reflection properties.

Preferably, a repair lacquer is applied to fill the crater, which has a shrinkage of more than about 30%, in particular more than about 50%, less than the color-providing lacquer of the original finish surrounding the repair site. This can be achieved by a refinish with a solids content of more than about 40%, but more preferably more than about 50%.

According to the invention, the repair lacquer is preferably applied so thickly that the repair point has only a deviation, in particular an elevation, of a maximum of approximately 10 μm with respect to the lacquer level surrounding it. Particularly good results are obtained for deviations of at most about 5 microns, but in particular at most about 1 micron.

It has already been mentioned several times that the refinish varnish uses a coloring pigment-containing varnish and clear varnish which is used as a volume-filling material. includes. In this sense, the properties of the refinish paint explained above, such as hue, color impression, color saturation, brightness, reflection properties and shrinkage properties, basically relate to the sum of color coat and clear coat, regardless of whether they are applied as a mixture or in layers.

When misting the paint repair site, a color coat is preferably applied, which has a higher pigment density than the refinish, preferably color of the paint surrounding the repair site original paint or at least one color coat of the same paint batch is used. In this way, the color impression can be particularly well matched to the surrounding original finish. The overspray region preferably has a diameter of less than about 20 mm, but in particular less than about 10 mm, and is therefore also much smaller in area than is usual in the prior art. When misting, a color layer is preferably applied whose thickness is about 5 to 75%, but preferably 5 to 50%, in particular about 10 to 25%, of the thickness of the coloring layer of the original paint surrounding the repair site.

The misting of the repair site with color-providing paint in an overspray area with a diameter of, in particular, less than 10 mm is preferably achieved by shading the area surrounding the repair site by a diaphragm arranged at a distance from the surface, which is arranged before the misting. A diaphragm which is particularly suitable for this purpose comprises two films arranged one above the other on the coating surface and having openings lying one above the other. In this case, the opening of a paint-side arranged, spacing film has a larger diameter than the opening (aperture opening) of the overlying, the over-fog region-determining film. A preferred aperture diameter of less than 10 mm for the achievement of an overspray range is 1 to 5 mm, in particular 2 to 3 mm. At the same time, a film thickness of the film arranged on the paint side of 0.5 to 2.0 mm, in particular of 1 mm, has proven particularly useful. This film thickness specifies the distance between the aperture and the coating surface, which ensures a virtually continuous flow of the overspray region.

As in the repainting, that is, when filling and misting the paint repair site, as a coloring paint preferably color paint surrounding the repair site original paint or at least a paint of the same paint batch is used, it is also proposed according to the invention that in a conventional painting process always a certain amount of the paint used for painting varnish or the paint batch concerned is secreted and stored for any required later paint repair.

Further details, features and advantages of the present invention will become apparent not only from the appended claims - alone and / or in combination - but also from the following description of a preferred embodiment of the invention in conjunction with the accompanying drawings.

Figur 1

in einem stark vergrößerten Maßstab eine schematische Darstellung eines Querschnitts durch eine Automobillackierung mit einer typischen Lackierungsfehlstelle in Form eines Fremdeinschlusses;

Figur 2

in einem annähernd originalgetreuen Maßstab eine schematische Darstellung einer Draufsicht einer auf einen Fehlstellenbereich aufgeklebten Schutzfolie;

Figur 3

die Darstellung gemäß Figur 1 mit einer im Fehlstellenbereich erfindungsgemäß in den Lack eingebrachten kraterförmigen Vertiefung;

Figur 4

die Darstellung gemäß Figur 3 mit erfindungsgemäß aufgefülltem und übernebeltem Fehlstellenbereich und aufgeklebter Blende und

Figur 5

die Darstellung gemäß Figur 4 mit efindungsgemäß nachlackiertem Fehlstellenbereich zur Kaschierung des Fremdeinschlusses.

In the drawings show:

FIG. 1

on a greatly enlarged scale, a schematic representation of a cross-section through an automotive finish with a typical Lack Lack in the form of a foreign inclusion;

FIG. 2

in a nearly faithful scale a schematic representation of a plan view of a glued on a defect area protective film;

FIG. 3

the representation of Figure 1 with a defect in the area according to the invention introduced into the paint crater-shaped depression;

FIG. 4

the representation of Figure 3 with inventively filled and misted defect area and glued panel and

FIG. 5

the representation according to Figure 4 with according to the invention repainted defect area for lamination of foreign inclusion.

The coating according to FIG. 1 comprises a corrosion protection layer or KTL layer 12 having a thickness of approximately 17 to 22 μm applied to a metal sheet 10, an overlying filler layer 14 having a thickness of approximately 30 to 40 μm, a coloring basecoat film 16 having a thickness from about 12 to 30 microns and a protective clearcoat layer 18 having a thickness of about 35 to 40 microns. In the basecoat film 16 and the surfacer coat 14, a paint defect 20 reaching into the clearcoat film 18 is in the form of a small and nearly "punctiform" foreign inclusion in view of the automobile dimensions which, despite its small size, is clearly visible to the human eye through the clearcoat film 18 and therefore by a appropriate correction or repair process, such as the repair process of the invention described below, eliminated and / or concealed almost invisible to the human eye to obtain a perfect finish without value-reducing visible Lackierungsfehlstellen.

Before the beginning of the repair work according to the invention - as shown in the plan view in Figure 2 - the environment of Lackierungswehlstelle or repair site initially covered by a protective film 24 with only the flaw area exposed opening 26 so that the surrounding paint area safely protected from possible damage or traces of work becomes. A large-area masking of the entire or almost the entire vehicle as in conventional repair methods is not required. The protective film 24 is a preferably self-adhesive, square film having a side length a of approximately 50 × 50 mm consisting of a suitable plastic and having in the center a circular opening 26 with a diameter of approximately 2 mm, and so on is glued to the clearcoat layer 18 that the Lackierungsfehlstelle 20 is located in the middle of the opening 26. The protective film 24 is provided with a cross-shaped mark 28, in the center of which the opening 26 is located. The marker 28 serves to identify the opening 26 and the more comfortable positioning of the opening 26 on the flaw 20. For easier attachment and easier handling, the left side of the film is provided with a handle device 30 in the form of a corresponding non-self-adhesive edge reinforcement. The protective film 24 may be formed in different colors and at the same time transparent and thus at the same time be used as a marking device for painting defects to be removed or laminated, depending on the car color. The thickness of the protective film is about 0.2 mm in the present embodiment.

After the application of the protective film, the lacquer layer in the defective area according to FIG. 3 is removed by cratering into the filler layer 14 by means of a vacuum sandblasting process, whereby at the same time the enclosure 20 is removed or removed so far that it no longer extends beyond the coloring basecoat 16 protrudes into the clearcoat 18. The diameter of the ablation area at the surface is defined by the diameter of the opening 26 of the protective film 24 and is thus about 2 mm. He is thus only slightly larger than the inclusion 20 itself.

In the sand blasting method used, a blasting medium is directed by means of a built-up negative pressure over an acceleration section to the blasting, erosion or repair site, the ablation speed and the depth and shape the forming paint well is controlled by the abrasive abrasive blasting agent amount. The desired dosage is carried out either by limiting the amount of blasting agent available or by limiting the time of the blasting process with continuous blasting agent supply. However, it is also possible to control the particle velocity and / or particle size and / or the actual abrasive material. By the. Under pressure not only the Strahlmittelteilchen, but also the removed paint particles and Fremdeinschlussteilchen be sucked and thus protects the near and further environment of the repair so reliable against possible damage from flying particles. However, other suitable material removal processes, such as a laser process, may be used to create the desired crater-shaped depression in the defect area and to partially or completely remove the coating defect.

After removal of the paint and the formation of a crater-shaped recess 22 of desired shape and size in the defect area, the recess 22 is first wiped with a, moistened with a mixture of isopropanol and distilled water soft cloth to possibly prior to the inventive application of the repair paint 16a, 18a to remove adhering paint particles or dirt particles. However, other cleaning options, such as blowing with compressed air or the like, may be used.

After cleaning the paint recess 22 produced, a colorant basecoat film 16a is first applied to the oblique sidewalls and to the bottom portion of the recess 22, as shown in FIG. 4, to achieve an optimal repair result with one for the human eye barely visible repair point 22 original base coat 16 of the repair area 22 surrounding original finish 12, 14, 16, 18 or at least one coat of the same paint batch is used. This paint is filled or deposited during application of the original paint 12, 14, 16, 18 and stored for any subsequent paint repairs.

After application of the basecoat film 16a into the recess 22, the protective coating 24 surrounding the paint repair site, self-adhesive or self-adhesive, applied protective film 24 is simply removed from the paint film and disposed of without residue.

Subsequently, the remaining remainder of the recess 22 is filled with clearcoat 18a, which serves as a volume-filling material without color impression. The clearcoat 18a is in this case applied so thickly that after the clearcoat 18a has dried, the repair point 22 only has a minimal deviation of a few micrometers or more, in particular with respect to the surface of the surrounding clearcoat layer 18, but in particular a slight elevation of less than approximately 1 μm, which is then ground and polished to the surrounding clearcoat level. The clearcoat 18a is chosen so that after drying and optionally grinding only a shrinkage of at most about 3 microns occurs. Due to their good shrinkage properties, so-called UV clearcoats proved to be particularly effective.

Another possibility is to fill the recess 22 introduced into the lacquer 12, 14, 16, 18 with a mixture of base lacquer 16 and clear lacquer 18, in which case original base lacquer 16 again surrounds the repair site 22 in order to achieve optimum repair results Original finish 12, 14, 16, 18 or at least one coat of the same lot of paint is used. The mixing ratio between the basecoat 16 and the clearcoat 18 is chosen so that the mixture used as a refinish coating has a shrinkage of more than about 30%, but preferably more than about 50%, less than the original basecoat 16, which results in a high Solids content of more than about 40%, but more preferably more than about 50%, can be achieved, which is introduced by the base varnish 16 diluting clearcoat 18 with its high solids content of about 60% in the repair paint. In both variants of the method, the color impression of the filled-in recess 22 or the paint repair point 22 thus already essentially corresponds to the desired color impression of the original finish 12, 14, 16, 18 surrounding it.

After filling the paint cavity 22 with repair paint 16a, 18a, allowing the drying and grinding of the applied repair paint 16a, 18a to the level of the surrounding clearcoat 18, the repair site for lamination of the color transitions by means of the precision sprayer with original basecoat 16 is fogged. To limit the overfoaming region to a diameter preferably below 10 mm, the region surrounding the repair point 22 is shaded by means of a diaphragm 32. For this purpose, initially a self-adhesive or self-adhesive first film 32a having a film thickness of about 1 mm is applied to the surface of the original finish 12, 14, 16, 18 such that an opening 34 of the film 32a of about 8 mm is positioned over the repair point 22. Then, a second film 32b is glued with an aperture 36 of about 2 to 3 mm on the first film 32a, wherein the Aperture opening 36 is arranged centrally above the opening 34 of the first film 32a. Alternatively, the films 32a, 32b may be glued to each other prior to application and then applied as a unit to the repair site 22. The first film 32a serves as a distance sensor for the second film 32b. The spray diameter is determined by the aperture 36. After application of the panel 32, the defect area is covered with a thin basecoat 16b, the thickness of which depending on the color used about 5 to 75%, but especially about 5 to 50% and preferably about 10 to 25% of the layer thickness of the original basecoat 16. The diameter of the overfoaming region here is usually only less than about 20 mm, but in particular significantly less than about 10 mm, with a diameter of the crater-shaped depression of about 2 to 4 mm. The spaced arrangement of the aperture 36 over the repair point 22 results in a gradual leakage of the edges of the over-fogging range, which is almost invisible to the eye. If the film 32b of the panel 32 were glued directly onto the surrounding clearcoat 18, there would inevitably be a visible edge.

When misting the paint repair site is important to ensure that the sum of the color pigments or effect pigments, which arises by covering the two paint jobs 16a and 16b, in the color impression of the surrounding paint 12, 14, 16, 18 corresponds. In this case, typically about 75% to 90% of the original color impression is already achieved by filling the recess 22 with repair lacquer 16a, 18a, ie with base lacquer 16a and clear lacquer 18a, while the misting with base lacquer 16b only corrects the color impression or reflection impression produced in this way , The exact ratio varies from color to color. If the lacquer recess 22 is filled with repair lacquer 16a, 18a too lightly or not sufficiently opaque, that is to say with too low a pigment density, the second color layer 16b applied by overspraying must become very dense in order to cover the repair site. If this color layer 16b becomes too thick as a result, it is conspicuously visible in the original finish 12, 14, 16, 18. On the other hand, if one mists too little, the filled-in lacquer recess 22 will shine through the second color layer 16b. Likewise, if there is too much in the ratio between the repair paint 16a, 18a in the resist groove 22 and the second ink layer 16b or the second spot. However, a correction of a too dark crater filling or a too dark repair varnish 16a, 18a by misting is therefore hardly possible, since the sum of the color pigments is greater over the circular varnish repair site than in the area. The same applies to a correction of a high level of effect pigments in the repair paint 16a, 18a.

After the applied basecoat film 16b has dried, the aperture 32 is removed and the defect area is finally covered with a protective clearcoat film 18b and polished after it has dried. The result is shown in FIG.

Of course, the field of application of the method according to the invention is not limited to the elimination of painting defects in the automotive industry. Rather, the described method can be used advantageously everywhere where it is necessary to eliminate punctiform or small coating defects of the type mentioned as small as possible and almost inconspicuously. As already mentioned, this also applies in particular to curved surfaces.

Claims (58)

1. Method of repairing paint finish defects (20), especially small paint finish defects (20) in a car paint finish, the paint finish (12, 14, 16, 18) being effaced in the defect region to a depth such that the paint finish defect (20) is at least partly removed, and an indentation (22) produced by the effacement being repainted, characterized in that the repainting comprises applying at least one refinish paint film (16a, 18a) into the indentation (22), overspraying the defect region with a coloured paint (16b) and applying a clearcoat film (18b), and the refinish paint film (16a, 18a) comprises at least one coloured paint film (16a) and one clearcoat film (18a) or a coating film of a coating-material mixture comprising coloured paint (16a) and a clearcoat material (18a).
2. Method according to Claim 1, characterized in that the paint finish (12, 14, 16, 18) is effaced in a region whose diameter corresponds to not more than 10 times the diameter of the paint finish defect (20).
3. Method according to Claim 2, characterized in that the diameter of the effacement corresponds to not more than 5 times the paint finish defect (20).
4. Method according to Claim 2 or 3, characterized in that the paint finish (12, 14, 16, 18) is effaced in a region measuring 0.5 to 20 mm.
5. Method according to Claim 4, characterized in that the paint finish (12, 14, 16, 18) is effaced in a region measuring 0.6 to 10 mm.
6. Method according to Claim 5, characterized in that the paint finish (12, 14, 16, 18) is effaced in a region measuring 0.7 to 4 mm.
7. Method according to Claim 6, characterized in that the paint finish (12, 14, 16, 18) is effaced in a region measuring 0.8 to 2 mm.
8. Method according to any one of the preceding claims, characterized in that the paint finish (12, 14, 16, 18) is effaced down into a colouring basecoat film (16) located below the clearcoat film (18), or into a surfacer film (14) located below that.
9. Method according to any one of the preceding claims, characterized in that the paint finish (12, 14, 16, 18) is effaced down to a depth of 55 to 75 µm with respect to the surface.
10. Method according to any one of the preceding claims, characterized in that the effacement produces a craterlike indentation (22) having a side slope of 30 to 95°.
11. Method according to Claim 10, characterized in that the effacement produces a craterlike indentation (22) having a side slope of 60 to 80°.
12. Method according to any one of the preceding claims, characterized in that the paint finish (12, 14, 16, 18) is effaced by means of an extractive drilling, milling or abrading process, a blasting process or another material effacement process.
13. Method according to Claim 12, characterized in that the paint finish (12, 14, 16, 18) is effaced with a sandblasting process and in the course thereof a subatmospheric pressure is utilized in order to accelerate the blasting agent.
14. Method according to Claim 13, characterized in that the operation of effacing the paint finish (12, 14, 16, 18) is controlled via a blasting agent and/or a blasting agent quantity and/or a blasting agent speed and/or a blasting time of the sand blasting process.
15. Method according to Claim 13 or 14, characterized in that a sand blasting process is used in which the subatmospheric pressure is utilized at the same time for drawing off the blasting agent and effaced paint particles under suction.
16. Method according to Claim 1, characterized in that coloured paint (16) of the original paint finish (12, 14, 16, 18) surrounding the refinish site (22), or a coloured paint from the same paint batch, is used as coloured paint (16a) for the refinish paint material (16a, 18a) and/or as colouring paint material (16b) for the overspraying.
17. Method according to either of Claims 1 and 16, characterized in that a UV coating material is used as clearcoat material (18a) for the refinish paint material (16a, 18a) and/or for the concluding clearcoat film (18b).
18. Method according to any one of Claims 1, 16 and 17, characterized in that the defect region is cleaned before a paint film is applied.
19. Method according to Claim 18, characterized in that an isopropanol/water mixture is used for cleaning.
20. Method according to any one of Claims 1 and 16 to 19, characterized in that the defect region is abraded and/or polished before and/or after overspraying and/or after application of the clearcoat film (18b).
21. Method according to any one of Claims 1 and 16 to 20, characterized in that repainting is carried out using a precision spraying means.
22. Method according to any one of the preceding claims, characterized in that the paint region surrounding the defect region is masked, prior to effacement, abrading, polishing and/or the application of a paint film, by a protective sheet (24) having an opening (26) which exposes only the defect region and its immediate surroundings.
23. Method according to Claim 22, characterized in that the paint region surrounding the defect region is masked with the protective sheet (24) before the paint finish (12, 14, 16, 18) is effaced.
24. Method according to Claim 22 or 23, characterized in that the opening (26) in the protective sheet (24) defines the dimensions of the effacement region, in particular of the crater (22).
25. Method according to Claim 1, characterized in that the repainting comprises applying at least one pigmented refinish paint film (16a, 18a) into the indentation (22), overspraying the defect region with a pigmented coloured paint material (16b) and applying a clearcoat film (18b), a sum total of the colour pigments and/or effect pigments of the refinish paint film (16a, 18a) applied into the paint indentation (22) and of the oversprayed coloured paint film (16b) corresponding to 85% to 115% of the sum total of the original paint finish (12, 14, 16, 18) surrounding the refinish site (22), based in each case on an axis extending perpendicularly to a paint surface.
26. Method according to Claim 25, characterized in that the sum total of the colour and/or effect pigments of the refinish paint film (16a, 18a) and of the oversprayed coloured paint film (16b) corresponds to 90% to 110%, in particular 97% to 103%, of the sum total of the colour and/or effect pigments of the surrounding original paint finish (12, 14, 16, 18).
27. Method according to Claim 1, characterized in that the repainting comprises applying at least one pigmented refinish paint film (16a, 18a) into the indentation (22), overspraying the defect region with a pigmented coloured paint material (16b) and applying a clearcoat film (18b), a fraction of colour pigments and/or effect pigments in the refinish paint material (16a, 18a) applied into the paint indentation (22) being calculated such that a sum total of the colour pigments and/or effect pigments of the refinish paint film (16a, 18a) corresponding to 50% to 95% of the sum total of colour and/or effect pigments of a coloured paint layer (16) of the original paint finish (12, 14, 16, 18) surrounding the refinish site (22), based in each case on an axis extending perpendicularly to a paint surface.
28. Method according to Claim 27, characterized in that the sum total of the colour and/or effect pigments of the refinish paint layer (16a, 18a) applied into the paint indentation (22) corresponds to 65% to 92% of the sum total of the colour and/or effect pigments of the original paint finish (12, 14, 16, 18).
29. Method according to Claim 28, characterized in that the sum total of the colour and/or effect pigments of the refinished paint layer (16a, 18a) corresponds to 75% to 90% of the sum total of the colour and/or effect pigments of the original paint finish (12, 14, 16, 18).
30. Method according to any one of Claims 27 to 29, characterized in that the sum total of the colour and/or effect pigments of the coloured paint film (16b) overspraying the refinish paint film (16a, 18a) is calculated such that it complements a difference in the colour and/or effect pigments between original paint finish (12, 14, 16, 18) and refinish paint film (16a, 18a).
31. Method according to any one of Claims 27 to 30, characterized in that a luminance of the refinish paint film (16a, 18a) is greater than or equal to a luminance of the original paint finish (12, 14, 16, 18) surrounding the refinish site (22).
32. Method according to Claim 25 or 27, characterized in that at least 80% of effect pigments of the refinish paint film (16a, 18a) adopt, after drying, an orientation which is substantially parallel to an orientation of the effect pigments of an original paint finish (12, 14, 16, 18) surrounding the refinish site (22).
33. Method according to Claim 32, characterized in that at least 90% of the effect pigments of the refinish paint film (16a, 18a) are orientated substantially parallel to the effect pigments of the original paint finish (12, 14, 16, 18) surrounding the refinish site (22).
34. Method according to Claim 33 or 34, characterized in that a plane of principal reflection of effect pigments of the refinish paint film (16a, 18a) deviates, after drying, by not more than 10°, in particular by 5° at most, from a plane of principal reflection of the effect pigments of an original paint finish (12, 14, 16, 18) surrounding the refinish site (22).
35. Method according to Claim 25 or 27, characterized in that a surface tension of the effect-pigmented refinish paint material (16a, 18a) is set such that said paint material, after drying, develops a substantially planar surface and a maximum height deviation with respect to the surrounding paint level of 10 µm at most.
36. Method according to Claim 35, characterized in that the height deviation is 5 µm at most, in particular 1 µm at most.
37. Method according to Claim 35 or 36, characterized in that the surface tension is set by appropriate selection of a solvent of the refinish paint material (16a, 18a).
38. Method according to Claim 25 or 27, characterized in that an effect-pigmented refinish paint is applied whose degree of reflection is independent of a viewing angle.
39. Method according to Claim 38, characterized in that the effect pigments of the refinish paint material (16a, 18a) possess a three-dimensional design in which a ratio of extents of two dimensions is in each case 0.2 to 5.
40. Method according to Claim 38 or 39, characterized in that the effect pigments possess a substantially tetrahedral, cubic, octahedral or other design of substantially equal area, or a spherical design.
41. Method according to Claim 1, characterized in that a refinish paint material (16a, 18a) is applied which possesses a contraction lower by more than 30% than that of the colouring paint material (16) of the original paint finish (12, 14, 16, 18) surrounding the refinish site (22).
42. Method according to Claim 41, characterized in that the refinish paint material (16a, 18a) possesses a contraction lower by more than 50% than that of the colouring paint material (16) of the original paint finish (12, 14, 16, 18).
43. Method according to Claim 41 or 42, characterized in that a refinish paint material (16a, 18a) is applied which contracts by ≤ 3 µm after drying has taken place.
44. Method according to Claim 1, characterized in that a refinish paint material (16a, 18a) having a solids content ≥ 40% is used.
45. Method according to Claim 44, characterized in that a refinish paint material (16a, 18a) having a solids content ≥ 50% is used.
46. Method according to any one of the preceding claims, characterized in that the refinish paint material (16a, 18a) is applied in a thickness such that the refinish site, with respect to the paint level (18) surrounding it of the original paint finish (12, 14, 16, 18) than has only a deviation, in particular an excess height, of not more than 10 µm after drying has taken place.
47. Method according to Claim 46, characterized in that the deviation is not more than 5 µm.
48. Method according to Claim 47, characterized in that the deviation is not more than 1 µm.
49. Method according to Claim 1, characterized in that a coloured paint material (16b) is applied which possesses a higher pigment density than the refinish paint material (16a, 18a).
50. Method according to Claim 49, characterized in that the overspraying takes place on a region of small area having a diameter of less than 20 mm.
51. Method according to Claim 50, characterized in that the diameter is less than 10 mm.
52. Method according to Claim 1, characterized in that the overspraying applies a coloured film (16b) whose thickness is 5% to 75% of the colouring film (16) of the original paint finish (12, 14, 16, 18) surrounding the refinish site (16a, 18a).
53. Method according to Claim 52, characterized in that the paint film thickness is 5% to 50% of the colouring film (16) of the original paint finish (12, 14, 16, 18) surrounding the refinish site (16a, 18a).
54. Method according to Claim 53, characterized in that the paint film thickness is 10% to 25% of the colouring film (16) of the original paint finish (12, 14, 16, 18) surrounding the refinish site (16a, 18a).
55. Method according to Claim 1, characterized in that, prior to overspraying, the region surrounding the refinish site (16a, 18a) is shaded off by a mask (32) disposed at a distance from the surface.
56. Method according to Claim 55, characterized in that, prior to overspraying, the region surrounding the refinish site (16a, 18a) is shaded off by a mask (32) and the mask (32) comprises two sheets (32a, 32b) arranged one above the other and having openings (34, 36) arranged one above the other, the opening (34) in the distancing sheet (32a) arranged on the paint side possessing a larger diameter than the mask opening (36) of the sheet (32b) determining the overspraying region.
57. Method according to Claim 56, characterized in that a distancing sheet thickness of the sheet (32a) arranged on the paint side is 0.5 to 2.0 mm, in particular 1 mm.
58. Method according to Claim 57, characterized in that the diameter of the mask opening (36), determining the overspraying region, of the sheet (32b) is 1 to 5 mm, in particular 2 to 3 mm.

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