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
  • B05D7/50—Multilayers
  • B05D7/56—Three layers or more
  • B05D7/57—Three layers or more the last layer being a clear coat
  • B05D7/572—Three layers or more the last layer being a clear coat all layers being cured or baked together
• • 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
  • B05D2202/00—Metallic substrate

Definitions

• the invention relates to a motor vehicle with a multi-layer coating comprising a colored lacquer layer containing polyester-amine resins as a binder, a transparent effect lacquer layer thereon containing polyester-amine resins and cellulose ethers and / or esters or half-esters as a binder, and a clear lacquer layer thereon containing thermosetting acrylic-melamine-resin combinations or air-drying acrylic-isocyanate-resin combinations as binders.
• the invention also relates to a method for multi-layer painting of motor vehicles.
• Corrosion protection layers in the sense of the present invention are understood to mean all protective layers or lacquer layers which are applied to the metal parts before the final lacquer is applied. This also includes the filler layers that are usually applied before the final coating. If a final coating with a metallic effect is carried out, this usually involves a two-layer coating.
• the lower layer contains metal platelets, generally aluminum platelets, to produce the so-called metallic effect. If not only the silver-metallic effect of the aluminum plates is desired, but a colored metallic coating, this layer also contains appropriate color pigments.
• a clear lacquer is then applied to this lacquer layer containing the metal flakes.
• the metallic coating can contain cellulose esters, in particular cellulose acetobutyrate (see US Pat. No. 3,639,147). According to this prior art, it is also possible to apply the metallic lacquer layer and the clear lacquer layer by the so-called wet-on-wet method, i.e. the metallic lacquer layer is not cured before the clear lacquer layer is applied, and both layers are then cured together.
• DE-OS 30 35 917 describes a method for applying a multilayer coating to a motor vehicle, according to which an effect coating layer is applied to a color coating layer, which contains titanium dioxide-coated mica platelets as an interference pigment, and optionally a clear coating layer thereon is applied.
• a color coating layer which contains titanium dioxide-coated mica platelets as an interference pigment, and optionally a clear coating layer thereon is applied.
• at least the effect lacquer layer is applied by an electrostatic application method.
• a prerequisite for carrying out this process is that the colored lacquer layer is stoved before the effect lacquer layer can be applied.
• the method described above has the disadvantage that the baking process has to be carried out twice.
• the parts of the motor vehicle which are not to be painted have to be taped twice.
• the colored lacquer layer is applied and baked, the parts that are not to be painted must be protected by masking before applying a paint. After the stoving process, the masking must be removed and the lacquer layer is sanded wet in order to achieve a better bond with the lacquer layer applied afterwards.
• the parts that are not to be painted must then be taped again before the effect paint layer and, if appropriate, the clear coat layer are applied and baked. This process is technically very complicated.
• the present invention is based on the task of creating motor vehicles with an effect lacquer layer which, as in DE-OS 30 35 917, has a more iridescent effect or different effects at different angles than the known metallic lacquer, but which are applied in a simpler manner can. It has surprisingly been found that this problem can be solved in that the three layers of colored lacquer layer, effect lacquer layer and clear lacquer layer are applied wet-on-wet and cured in one operation if the colored lacquer layer has a certain de finished composition.
• the invention accordingly relates to a motor vehicle with a multilayer coating comprising a colored lacquer layer containing polyester-amine resins as a binder, a transparent effect lacquer layer thereon containing polyester-amine resins and cellulose ethers and / or esters or semesters as binders, and one thereon located clearcoat layer containing heat-curable acrylic-melamine-resin combinations or air-drying acrylic-isocyanate-resin combinations as a binder, which is characterized in that the colored lacquer layer is 15 to 60% by weight, based on the binder content of this layer, of cellulose ethers and / or esters or semesters.
• the invention furthermore relates to a process for the multilayer coating of motor vehicles, comprising a colored lacquer layer containing polyester-amine resins as a binder, a transparent effect lacquer layer thereon containing polyester-amine resins and cellulose ether and / or ester or half-ester as binder, and a clear lacquer layer thereon containing a thermosetting acrylic-melamine-resin combination or air-drying acrylic-isocyanate-resin combination as a binder, which is characterized in that the colored lacquer layer comprises 15 to 60% by weight, based on the proportion of binder in this layer Contains cellulose ethers and / or esters or half-esters, and that all three layers mentioned wet-on-wet applied and ge can be cured together in one operation, the effect lacquer layer being applied by an electrostatic application process.
• the colored lacquer layer preferably has a dry film thickness of 10 to 30 ⁇ m .
• the colored lacquer layer contains as a binder the polyester amine resin systems known according to the prior art for motor vehicle coatings. Oil-containing or oil-free polyesters can be used, in particular alkyd resins. The polyesters are present in a mixture with amine resins, with melamine resins being preferred.
• the colored lacquer layer contains pigments usually used in automotive painting. If a white layer is desired, white pigments are used, otherwise colored pigments.
• the essential feature according to the invention is that the colored lacquer layer contains the above cellulose ethers, etc. According to the prior art, such cellulose ethers were added to the metallic lacquers in order to bring about a rapid fixation of the metallic flakes.
• Another essential feature of the method for multi-layer painting according to the invention is that the effect lacquer layer is applied by an electrostatic application process.
• cellulose ethers, etc. those compounds are used for the colored lacquer layer which are used according to the prior art for the metallic lacquers. As in the prior art, cellulose acetobutyrate is preferred.
• the amount for the colored lacquer layer according to the invention is preferably at least 30% by weight, and preferably at most 50% by weight, based on the binder content of this layer.
• an essential feature according to the invention is that the effect lacquer layer applied to the color lacquer layer is transparent. This is understood to mean an at least partial transparency as it is obtained when mica platelets coated with titanium dioxide are used as interference pigments. These pigments are known (see, for example, DE-OS 19 59 998 and DE-AS 14 67 468).
• the effect lacquer layer according to the invention preferably contains the same binders as the color lacquer layer, and as already described above, as binders.
• the effect lacquer layer also contains the cellulose ethers etc. described above, and advantageously in an amount of 15 to 60% by weight.
• the lower limit is preferably about 20% by weight.
• the upper limit is preferably 40% by weight.
• the amount of cellulose ethers etc. in the colored lacquer layer according to the invention is relatively high compared to the prior art.
• the dry film thickness of the effect lacquer layer. is expediently in the range from about 5 to 25 ⁇ m .
• the lower limit is preferably about 10 / ⁇ m, while the upper limit is preferably about 15 / ⁇ m.
• the electrostatic application methods known per se can be used.
• the paint in a stationary system, the paint can be sprayed over a rotating bell or disc in an electrostatic field, so-called Randsburg (registered trademark) systems. It can also be sprayed with known electrostatic spray guns.
• a clear lacquer layer is applied to the effect lacquer layer, which has either thermosetting acrylic-melamine-resin combinations or air-drying acrylic-isocyanate-resin combinations as binders. Both paint systems are known in the field of painting motor vehicles. If the heat-curable combinations are used, all layers of paint must be cured together in one operation by heating to elevated temperatures.
• There are applied the prior art conventionally used for the final coating hardness temperatures for example from about 70 ° C to 170 0 C for periods of from about 10 to 40 minutes, in general, the duration of the stoving is inversely proportional to the temperature employed.
• the known air-drying systems are used according to the invention, which is mainly the case in motor vehicle refinishing
• the motor vehicle provided with the three layers of lacquer according to the invention is dried under environmental conditions or heated to moderate temperatures of not more than about 80 ° C. All three layers of paint are cured.
• the dry film thickness of the clear coat layer is suitably 15 to 50 / um, which are for the lower limit of 20 / um and for the upper limit of 40 / um are preferred.
• the term “acrylic” is also understood to mean methacrylic resin systems, as are also used in this field according to the prior art (cf., inter alia, US Pat. No. 3,639,147, GB Pat. No. 1,284,755, DE-OS 28 12 397).
• the proportion of mica platelets coated with titanium dioxide in the effect lacquer layer is expediently 0.5 to 8% by weight, preferably at least approximately 1% by weight and at most approximately 6% by weight, calculated on the total weight of the lacquer 3 to 40% by weight, preferably 4 to 30% by weight, depending on the color of the substrate.
• those of the resin systems described above are preferably used which physically dry in 1 to 15 minutes, preferably 2 to 12 minutes, particularly preferably 3 to 8 minutes.
• the effect lacquer layer it is expedient to apply the effect lacquer layer to the colored lacquer layer after 1 to 15 minutes, preferably 2 to 12 minutes, particularly preferably 3 to 8 minutes.
• the layers applied in front of it must, as stated above, be physically dried within the stated time to such an extent that substantial mixing or greater swelling of the varnish layers applied to them is avoided during application.
• the above-mentioned drying times for the effect lacquer also have the effect that the binder solidifies very quickly and that therefore the mica platelets coated with titanium dioxide can no longer move in the layer.
• the mica flakes Shortly after the application of the effect lacquer layer, the mica flakes predominantly assume an arrangement approximately parallel to the substrate. This arrangement leads to the special effect. If, however, the mica platelets can move, in particular rotate, for a long time in the applied layer, there is a risk that they will adopt a different orientation to a considerable extent, as a result of which the iridescent
• the interference effect is particularly pronounced and is strongly obtained when the layers, in particular the effect lacquer layer and the colored lacquer layer, have the strengths specified above.
• the paints used according to the invention naturally contain the usual paint additives and solvents.
• a colored lacquer layer is applied to the provided in conventional manner with anticorrosive coatings body parts / um applied in a dry film thickness of 20, which contains an oil-free polyester resin and melamine resin, a content of 40 wt .-% cellulose acetate butyrate, based on the binder content of this layer, and contains 35% Bayferrox 3920 FF (inorganic brown pigment), calculated on the total solid content, as well as conventional paint additives and solvents.
• Bayferrox 3920 FF inorganic brown pigment
• an effect paint layer is applied in a dry film thickness of 10 / um, which contains an oil-free polyester and melamine resin as a binder , having a content of about 32 wt .-% cellulose acetate butyrate, based on the binder content of this layer and 2 wt .-% titanium dioxide in rutile form coated mica flakes, relative to the varnish, and the usual L ackzu accounts and contains solvent.
• the clear lacquer layer is applied thereon, which contains an acrylic-melamine resin combination which is customary in motor vehicle painting in a customary solvent mixture.
• the dry film thickness of this layer is about 30 / um. Then baked at about 140 0 C for 20 minutes.
• a motor vehicle with a conventional filler paint is sanded. Then a layer of colored paint is applied by the usual spraying process with a dry film thickness of 25 / um, which contains an oil-free polyester and melamine resin, has a content of 35% cellulose acetobutyrate, based on the binder content of this layer, and 55% rutile titanium dioxide, calculated on the total solid content, as well as usual Contains paint additives and solvents.
• the effect coating is applied to a dry film thickness of 15 / by means of an electrostatic hand spray gun. It contains an oil-free polyester, melamine resin and 30% by weight of cellulose acetobutyrate, based on the binder, and 5% by weight, based on the lacquer, of the interference pigment described in Example 1 as the binder.
• an acrylic-Isocyanatharzkombination is coated as a binder in a dry film thickness of 30 / um with a clear lacquer, schauend. The mixture is then heated to 80 ° C for 10 minutes or 50 ° C for 1 hour or dried under environmental conditions.
• the vehicles painted in this way have an impressive iridescent effect. If the viewing direction is essentially vertical, the hue essentially corresponds to the hue of the interference pigment used. When the viewing angle changes, the background color appears more clearly.

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• Life Sciences & Earth Sciences (AREA)
• Engineering & Computer Science (AREA)
• Wood Science & Technology (AREA)
• Application Of Or Painting With Fluid Materials (AREA)
• Paints Or Removers (AREA)
• Laminated Bodies (AREA)

Applications Claiming Priority (2)

Publications (2)

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ID=6128120

Family Applications (1)

Country Status (7)

Cited By (4)

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Citations (2)

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• 1981
  • 1981-03-24 DE DE19813111478 patent/DE3111478A1/de not_active Withdrawn
• 1982
  • 1982-03-19 DE DE8282102250T patent/DE3260489D1/de not_active Expired
  • 1982-03-19 EP EP82102250A patent/EP0061165B1/fr not_active Expired
  • 1982-03-22 ES ES510621A patent/ES8308231A1/es not_active Expired
  • 1982-03-22 ZA ZA821928A patent/ZA821928B/xx unknown
  • 1982-03-23 BR BR8201616A patent/BR8201616A/pt unknown
  • 1982-03-23 JP JP57044780A patent/JPS57171473A/ja active Pending
  • 1982-03-24 AU AU81856/82A patent/AU8185682A/en not_active Abandoned

Patent Citations (2)

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