COATING SYSTEMS WITH INCREASED JETNESS OF BLACK AND IMPROVED COLOR

Abstract

Disclosed herein is a method of preparing a multilayer coating system on a substrate including a step of applying at least one organic black pigment containing basecoat composition to a substrate and forming a first coating film thereon (1), optionally subsequently applying a second basecoat composition and forming a second coating film adjacent to the first coating film (2), and applying a pigmented topcoat composition to the first coating film in case optional step (2) is not performed (3a), or applying a clearcoat composition to the second coating film in case optional step (2) is performed, and where steps (1), (2) and (3b) are performed, or steps (1) and (3a) are performed, includes at least one non-black coloring pigment having a volume average particle size of <1000 nm in an amount in the range of from 0.01 to 7.50 wt.-%, based on its total solid content.

Claims

1. A method of preparing a multilayer coating system onto an optionally pre-coated substrate comprising at least steps (1) and (3a) or at least steps (1), (2) and (3b), (1) applying a pigmented basecoat composition to an optionally pre-coated substrate and forming a first coating film on the optionally pre-coated substrate, wherein the basecoat composition comprises at least one organic black pigment, (2) optionally applying a second pigmented basecoat composition different from the basecoat composition applied in step (1) to the first coating film present on the substrate obtained after step (1) and forming a second coating film adjacent to the first coating film, and (3a) applying a coating composition different from the composition applied in step (1) and in optional step (2) to the first coating film present on the substrate obtained after step (1) and forming a second coating film adjacent to the first coating film in case optional step (2) is not performed, wherein the coating composition is a pigmented topcoat composition, or (3b) applying a coating composition different from the composition applied in step (1) and in optional step (2) to the second coating film present on the substrate obtained after step (2) and forming a third coating film adjacent to the second coating film in case optional step (2) is performed, wherein the coating composition is a clearcoat composition, wherein the second coating film obtained after step (3a) or the third coating film obtained after step (3b) is the outermost film of the formed multilayer coating system, characterized in that neither the second basecoat composition applied in optional step (2) nor the coating composition applied in step (3a) or (3b) comprises any black pigments, and in that—in case steps (1), (2) and (3b) are performed—the second basecoat composition or—in case steps (1) and (3a) are performed—the topcoat composition comprises at least one non-black coloring pigment having a volume average particle size of <1000 nm in an amount in the range of from 0.01 to 7.50 wt.-%, based in each case on the total solid content of the respective composition, wherein said at least one non-black coloring pigment is in each case incorporated into the respective composition in the form of a pigment paste.

2. The method according to claim 1, characterized in that the at least one non-black coloring pigment present in either the second basecoat composition or in the topcoat composition is a blue pigment.

3. The method according to claim 1, characterized in that the pigment paste containing the at least one non-black coloring pigment, which is used for preparing the second basecoat composition or for the topcoat composition has a haze of <20%.

4. The method according to claim 1, characterized in that the at least one non-black coloring pigment present in either the second basecoat composition or in the topcoat composition has a volume average particle size in the range of from 10 nm to <950 nm.

5. The method according to claim 1, characterized in that the at least one non-black coloring pigment present in either the second basecoat composition or in the topcoat composition has a Z-average particle size in the range of from 10 nm to 750 nm.

6. The method according to claim 1, characterized in that the multilayer coating system obtained after curing has a jetness (Mc) of at least 250, and/or has a jetness (Mc) value, which exceeds its blackness (My) value.

7. The method according to claim 1, characterized in that the at least one non-black coloring pigment is present in the second basecoat composition or in the topcoat composition in an amount in the range of from 0.01 to 5.00 wt.-%, based in each case on the total solid content of the respective composition.

8. The method according to claim 1, characterized in that the at least one non-black coloring pigment is present in the second basecoat composition in an amount in the range of from 0.10 to 5.00 wt.-%, based on the total solid content of the second basecoat composition or is present in the topcoat composition in an amount in the range of from 0.01 to 2.50 wt.-%, based on the total solid content of the topcoat composition.

9. The method according to claim 1, characterized in that the at least one organic black pigment present in the basecoat composition applied in step (1) is an IR-transparent organic black pigment.

10. The method according to claim 1, characterized in that the total solid content of the second basecoat composition or of the topcoat composition is in each case in the range of from 10 to 65 wt, in each case based on the total weight of the respective composition.

11. The method of claim 1, characterized in that optional step (2) is performed prior to curing the first coating film obtained after step (1), step (3a) is performed prior to curing the first coating film obtained after step (1) and step (3b) is performed prior to curing the second coating film obtained after step (2).

12. The method of claim 11, wherein the method comprises at least further step (4), (4) jointly curing all coating films applied in steps (1) and (3a) or steps (1), (2) and (3b) to obtain a cured multilayer coating system comprising at least a first and second coating layer, the second coating layer being the outermost layer of the formed multilayer coating system or comprising at least a first, a second and a third coating layer, the third coating layer being the outermost layer of the formed multilayer coating system.

13. A multilayer coating system present on an optionally pre-coated substrate, characterized in that it is obtainable by the method according to claim 1.

14. A coated substrate obtainable by the method according to claim 1.

15. A method of using a pigmented coating composition, which does not comprise any black pigments, comprises at least one non-black coloring pigment having a volume average particle size of <1000 nm in an amount in the range of from 0.01 to 7.50 wt.-%, based on the total solid content of the coating composition, wherein said at least one non-black coloring pigment is incorporated into the coating composition in the form of a pigment paste, in either step (2) as second basecoat composition or in step (3a) as topcoat composition of the method of preparing a multilayer coating system onto an optionally pre-coated substrate as defined in claim 1 for increasing the jetness (Mc) of the multilayer coating system obtained after curing to such an extent that the jetness (Mc) exceeds the blackness (My) of the cured multilayer coating system.

16. The method according to claim 1, characterized in that the at least one non-black coloring pigment present in either the second basecoat composition or in the topcoat composition is an organic blue pigment, which is the only coloring pigment present in the second basecoat or in the topcoat composition.

17. The method according to claim 1, characterized in that the pigment paste containing the at least one non-black coloring pigment, which is used for preparing the second basecoat composition or for the topcoat composition has a haze of <15%.

18. The method according to claim 1, characterized in that the pigment paste containing the at least one non-black coloring pigment, which is used for preparing the second basecoat composition or for the topcoat composition has a haze of <10%.

19. The method according to claim 1, characterized in that the at least one non-black coloring pigment present in either the second basecoat composition or in the topcoat composition has a volume average particle size in the range of from 25 nm to 900 nm.

20. The method according to claim 1, characterized in that the at least one non-black coloring pigment present in either the second basecoat composition or in the topcoat composition has a volume average particle size in the range of from 30 nm to 850 nm.

Description

EXAMPLES

[0144] The following examples further illustrate the invention but are not to be construed as limiting its scope. ‘Pbw’ means parts by weight. If not defined otherwise, ‘parts’ means ‘parts by weight’.

1. Preparation of Pigment Pastes

1.1 Preparation of Aqueous Pigment Pastes P1 to P7 and P2a

[0145] The pigment pastes indicated in Table 1 were prepared from the constituents and their amounts as listed in Table 1 by the following methods:

Pigment Paste P1

[0146] The black pigment paste P1 was produced by adding Paliogen® Black L0086 to a stirring mixture of dispersant 1, propylene glycol n-butyl ether and deionized water. The resulting suspension is agitated using a Cowles blade for 5 minutes. The pH is adjusted to 8.1 using a 20 wt.-% dimethyl ethanol amine aqueous solution (measured with Starter 300 pH Portable pH meter (Ohaus Corporation, Parsippany, New Jersey, USA)). The suspension is then transferred to a mixing jar and 0.9-1.1 mm YTZ milling media (Fox Industries) are added (2:1 weight ratio media:suspension). The suspension is then agitated using a LAU shaker (LAU disperser DAS 200—LAU GmbH) for 4 hours. The 0.9-1.1 mm YTZ media is separated using gravity filtration. The as collected paste is transferred into another mixing jar and infused with 0.3-0.4 mm YTZ milling media in a 2:1 beads to paste weight ratio and agitated using a LAU shaker (LAU disperser DAS 200—LAU GmbH) for 9 hours. The resulting final paste product is filtered to remove the 0.3-0.4 mm media and used with no further modifications as pigment paste P1.

Pigment Paste P2a

[0147] The blue pigment paste P2a was produced by adding Palomar® Blue 15:1-248-4816 (Sun Chemical) to a stirring mixture of dispersant 1, propylene glycol n-butyl ether and deionized water. The resulting suspension is agitated using a Cowles blade for 5 minutes. The pH is adjusted to 8.1 using a 20 wt.-% dimethyl ethanol amine aqueous solution (measured with Starter 300 pH Portable pH meter (Ohaus Corporation, Parsippany, New Jersey, USA)). The suspension is then transferred to a mixing jar and a 2:1-weight ratio (media:suspension) of 0.3-0.4 mm YTZ milling media (Fox Industries) are added. The suspension is agitated using a LAU shaker (LAU disperser DAS 200—LAU GmbH) for 10 hours. The resulting paste is separated by gravity filtration from the 0.3-0.4 mm YTZ media and used with no further modifications as pigment paste P2a.

Pigment Paste P2b

[0148] The blue pigment paste P2b was produced by further modification of pigment paste P2a. 5.7 parts of dispersant 2 is diluted with 14.3 parts of deionized water under agitation. This resin solution is then added slowly to 80 parts of pigment paste P2a under agitation. The resulting paste is then used with no further modifications as pigment paste P2b.

Pigment Paste P3

[0149] The blue pigment paste P3 was produced by adding dispersant 3 into a large mixing vessel and diluting said dispersant with deionized water, followed by addition of blue pigment Palomar® Blue 15: 1-248-4806 (Sun Chemical) in small aliquots. This slurry was sheared until it was homogenous and then further diluted with deionized water.

[0150] The suspension was then transferred into an Eiger bead mill (EMI) containing 0.9-1.1 YTZ beads (Fox industries) and processed to 275 Whr/kg. The resulting paste is then used with no further modifications as pigment paste P3 after removal of the beads.

Pigment Paste P4

[0151] The blue pigment paste P4 was produced by adding Palomar® Blue 15: 1-248-4806 (Sun Chemical) to a stirring mixture of dispersant 4, propylene glycol n-butyl ether and deionized water. The resulting suspension is agitated using a Cowles blade for 5 minutes. The pH is adjusted to 8.1 using a 20 wt.-% dimethyl ethanol amine aqueous solution (measured with Starter 300 pH Portable pH meter (Ohaus Corporation, Parsippany, New Jersey, USA)). The suspension is then transferred to a mixing jar and a 2:1-weight ratio (media:suspension) of 0.3-0.4 mm YTZ milling media (Fox Industries) are added. The suspension is agitated using a LAU shaker (LAU disperser DAS 200—LAU GmbH) for 10 hours. The resulting paste is separated by gravity filtration from the 0.3-0.4 mm YTZ media. 5.7 parts of dispersant 2 is diluted with 14.3 parts of deionized water under agitation. This resin solution is then added slowly to 80 parts of the above identified resulting paste under agitation. The then resulting paste is used with no further modifications as pigment paste P4 after removal of the beads.

Pigment Paste P5

[0152] The blue pigment paste P5 was produced by adding dispersant 5 into a large mixing vessel and diluting said dispersant with deionized water, followed by addition of wetting additive, polypropylene glycol and emulsifier. Then blue pigment Heucodur® Blue 550 (Heubach) was added in small aliquots. This slurry was sheared using a Cowles blade until homogenous. The resulting paste is then further diluted with deionized water, mixed well and then transferred into an Eiger Bead (EMI) mill for processing with 0.9-1.1 mm YTZ beads (Fox Industries) and milled to an energy of 300 Whr/kg in a 2:1-weight ratio (media:paste). The resulting paste is used with no further modifications as pigment paste P5 after removal of the beads.

Pigment Paste P6

[0153] The yellow pigment paste P6 was produced by adding dispersant 3, deionized water, propylene glycol n-propyl ether in a large mixing vessel, mixed well, and by adjusting the pH to 8.1 using a 20 wt.-% dimethyl ethanol amine aqueous solution (measured with Starter 300 pH Portable pH meter (Ohaus Corporation, Parsippany, New Jersey, USA)). To this solution Bayfast® Yellow Y-5688 (Bayer) is added in small aliquots under agitation and mixed until homogenous. This solution is then diluted with deionized water and the pH is adjusted again to 8.1 using a 20 wt.-% dimethyl ethanol amine aqueous solution (measured with Starter 300 pH Portable pH meter (Ohaus Corporation, Parsippany, New Jersey, USA)). The pigment paste is transferred to an Eiger Bead mill (EMI) containing 0.9-1.0 mm YTZ beads (Fox Industries) in a 2:1-media to paste weight ratio and milled to an energy of 175 Whr/kg. The resulting paste is used with no further modifications as pigment paste P6 after removal of the beads.

Pigment Paste P7

[0154] The yellow pigment paste P7 was produced by adding dispersant 3, deionized water, propylene glycol n-propyl ether and fumed silica in a large mixing vessel and mixed well. To this solution Irgazin® Yellow 3RLTN (BASF SE) is added in small aliquots under agitation and mixed until homogenous. The mixture is then diluted with deionized water and then is transferred to an Eiger Bead mill (EMI) containing 0.9-1.0 mm YTZ beads (Fox Industries) in a 2:1-media to paste weight ratio and milled to an energy of 190 Whr/kg. The resulting paste is used with no further modifications as pigment paste P7 after removal of the beads.

[0155] Dispersant 1 is composed of 42.5 wt.-% of (meth)acrylic resin solids, 31.3 wt.-% ethylene glycol monobutyl ether and 26.2 wt.-% deionized water.

[0156] Dispersant 2 is composed of 27.0 wt.-% of a urethane resin, 6.0 wt.-% of ethylene glycol monobutyl ether and 67.0 wt.-% of deionized water, adjusted with a small amount of dimethyl ethanol amine.

[0157] Dispersant 3 is composed of 35.5 wt.-% resin solids and 64.5 wt.-% solvents. The solvent content of the dispersant is as follows: 28.40 wt.-% propylene glycol n-propyl ether, 6.12 wt.-% methyl isoamyl ketone (MIAK), 28.45 wt.-% deionized water and 1.53 wt.-% mineral spirits. The resin present in the dispersant is prepared as disclosed in example 5 of U.S. Pat. No. 5,270,399.

[0158] Dispersant 4 is composed of 61 wt.-% resin solids and 39 wt.-% solvents. The resin is a PEG-modified polyester based star polymer.

[0159] Dispersant 5 is composed of 45.3 wt.-% (meth)acrylic resin solids and 54.6 wt.-% deionized water, adjusted with a small amount of dimethyl ethanol amine. The wetting additive is a commercially available wetting additive. The emulsifier is a commercially available emulsifier. The polypropylene glycol used is also commercially available.

TABLE-US-00001 TABLE 1 Pigment pastes P1, P2a, P2b and P3 to P7 Constituents P1 P2a P2b P3 P4 P5 P6 P7 Black pigment 1 10.0 g — — — — — — — Blue Pigment 1 — 10.0 g 8.0 g — — — — — Blue Pigment 2 — — — 25.65 g 8.0 g — — — Blue Pigment 3 — — — — — 33.0 g — — Yellow pigment 1 — — — — — — 18.4 g — Yellow pigment 2 — — — — — — — 40.0 g Fumed silica — — — — — — — 0.4 g Dispersant 1 14.5 g 14.5 g 11.6 g — — — — — Dispersant 2 — —  5.7 —  5.7 — — — Dispersant 3 — — — 24.8 g — — 26.6 g 7.6 g Dispersant 4 — — — — 9.8 g — — — Dispersant 5 — — — — — 47.0 g — — Propylene glycol 1.75 g 2.5 g 2.0 g — 2.0 g — — — n-butyl ether Propylene glycol — — — — — — 3.3 g 7.3 g n-propyl ether Wetting additive — — — — — 4.0 g — — Polypropylene — — — — — 3.0 g — — glycol Emulsifier — — — — — 0.3 g — — Deionized water 73.8 g 73.0 g 73.0 g 48.6 g 80.0 g 12.7 g 51.7 g 44.7 g Pigment amount, 62.5 62.5 55.8 75.0 51.3 53.6 74.0 92.8 based on total solid content [wt.-%]

[0160] As outlined hereinbefore the black pigment 1 present in pigment paste P1 is Paliogen® Black L0086. Pigment pastes P2a and P2b each contain blue pigment 1, which is Palomar® Blue 15: 1-248-4816. Pigment pastes P3 and P4 each contain blue pigment 2, which is Palomar® Blue 15: 1-248-4806. Blue pigment 3, which is present in pigment paste P5, is Heucodur® Blue 550. Yellow pigment 1 is Bayfast® Yellow Y-5688. Yellow pigment 2 is Irgazin® Yellow 3RLTN.

[0161] The pigment pastes P1, P2a, P2b and P3 to P7 have been analyzed via particle size analysis after their preparation including the milling step. Additionally, their haze has been measured. Both measuring of the haze and measurement of the particle size characteristics indicated in Table 2 have been performed according to the methods disclosed in the ‘Methods’ section. The measured values are indicated in Table 2. No values have been determined for pigment paste P2a.

TABLE-US-00002 TABLE 2 Haze and particle size characteristics of pigment pastes P1 to P7 P1 P2b P3 P4 P5 P6 P7 Haze 5.0 7.5 31.8 3.7 98.3 95.0 98.6 Volume average 123.7 761.5 1245.0 117.5 1353.0 2368.0 340.6 particle size (V-average) [nm] Z-average 131.9 262.5 229.6 133.1 390.3 413.7 274.9 particle size [nm] d.sub.N, 10% [nm] 75.2 176 149 84.3 252 233 165 d.sub.N, 50% [nm] 163 288 248 149 424 398 310 d.sub.N, 90% [nm] 321 478 426 264 759 854 564

1.2 Preparation of Solventborne Pigment Pastes P8 and P9

[0162] The pigment pastes indicated in Table 3 were prepared from the constituents and their amounts as listed in Table 3 by the following methods:

Pigment Paste P8

[0163] The blue pigment paste P8 was prepared by mixing Solsperse® 76500 (Lubrizol) and Solsperse 5000S® (Lubrizol) in n-butyl acetate, followed by slow addition of Palomar® Blue 248-4816 (Sun Chemical) with thorough agitation until homogeneity was achieved. The resulting mixture was further diluted with n-butyl acetate and transferred to an Eiger Bead mill (EMI) containing 0.9-1.1 YTZ media (Fox Industries) and milled to 500 Whr/kg (2:1-media to mixture weight ratio). The resulting paste was isolated and transferred to perform a second milling step using and Eiger mill (EMI) containing 0.3-0.4 mm YTZ media (Fox Industries) and processed to 3000 Whr/kg (2:1-media to mixture weight ratio). After milling was completed, the resulting paste is further reduced by using n-butyl acetate and then used with no further modifications as pigment paste P8 after removal of the beads.

Pigment Paste P9

[0164] The blue pigment paste P9 was prepared by mixing Ekfa® PX 4350 and Ekfa® MI 6745 in n-butyl acetate, followed by slow addition of Heliogen® Blue L6600F with thorough agitation until homogeneity was achieved. The resulting mixture was further diluted with n-butyl acetate and transferred to an Eiger Bead mill (EMI) containing 0.9-1.1 YTZ media (Fox Industries) and milled to 500 Whr/kg (2:1-media to mixture weight ratio). The resulting paste was isolated and transferred to perform a second milling step using and Eiger mill (EMI) containing 0.3-0.4 mm YTZ media (Fox Industries) and processed to 3500 Whr/kg (2:1-media to mixture weight ratio). After milling was completed, the resulting paste is further reduced by using n-butyl acetate and then used with no further modifications as pigment paste P9 after removal of the beads.

[0165] The formulations of pigment pastes P8 and P9 are indicated in Table 3.

TABLE-US-00003 TABLE 3 Pigment pastes P8 and P9 Constituents P8 P9 Blue Pigment 1  7.0 g — Blue Pigment 4 —  7.0 g Solsperse ® 76500 16.8 g — Solsperse ® 5000s  1.4 g — Ekfa ® MI 6745 —  0.3 g Ekfa ® PX 4350 — 11.0 g n-butyl acetate 74.8 g 81.7 g Pigment amount, 41.7 50.7 based on total solid content [wt.-%]

[0166] Pigment paste P8 contains blue pigment 1, which is Palomar® Blue 15:1-248-4816. Blue pigment 4 is Heliogen® Blue L6600F (a blue 15:6 pigment; BASF SE). Solsperse® 76500 is a commercially available dispersant (Lubrizol) and Solsperse® 5000s is a commercially available dispersing additive (Lubrizol). Ekfa® MI 6745 is a commercially available dispersing additive (BASF SE) and Ekfa® PX 4350 is a commercially available dispersant (BASF SE).

[0167] The pigment pastes P8 and P9 have been analyzed via particle size analysis after their preparation including the milling step. Additionally, their haze has been measured. Both measuring of the haze and measurement of the particle size characteristics indicated in Table 4 have been performed according to the methods disclosed in the ‘Methods’ section. The measured values are indicated in Table 4.

TABLE-US-00004 TABLE 4 Haze and particle size characteristics of pigment pastes P8 and P9 P8 P9 Haze 0.8 0.7 Volume average 108.9 54.6 particle size [nm] Z-average 54.2 63.8 particle size [nm] d.sub.N,10% [nm] 32.8 44.4 d.sub.N,50% [nm] 67.0 76.4 d.sub.N,90% [nm] 140.0 133.0

1.3 Preparation of Additional Aqueous Pigment Pastes P10 to P12

[0168] Three additional pigment pastes containing commercial black pigments have been prepared. P10 and P11 both contained a commercial organic azomethine black pigment, namely Chromofine® A-1103 (Dainichiseika Chemicals). P12 contained a commercial inorganic black pigment, namely the carbon black pigment Monarch® 1300 (Cabot).

[0169] The pigment pastes indicated in Table 4a were prepared from the constituents and their amounts as listed in Table 4a by the following methods:

Pigment Paste P10

[0170] The black pigment paste P10 was produced by adding Chromofine® Azo Black A-1103 (Dainichiseika Chemicals) to a stirring mixture of dispersant 1, propylene glycol n-butyl ether and deionized water. The resulting suspension was agitated using a Cowles blade for 5 minutes. The pH is adjusted to 8.1 using a 20 wt.-% dimethyl ethanol amine aqueous solution (measured with Starter 300 pH Portable pH meter (Ohaus Corporation, Parsippany, New Jersey, USA)). The suspension was transferred to a mixing jar and a 2:1 weight ratio of 0.9-1.1 mm YTZ milling media (Fox Industries) (media:suspension) was added and the suspension was agitated using a LAU shaker (LAU disperser DAS 200—LAU GmbH) for 5 hours. The 0.9-1.1 mm YTZ media was separated using gravity filtration. The as collected paste was transferred into another mixing jar and infused with 0.3-0.4 mm YTZ milling media in a 2:1 beads to paste weight ratio and agitated using a LAU shaker (LAU disperser DAS 200—LAU GmbH) for 12 hours. The resulting final paste was filtered to remove the 0.3-0.4 mm media and used with no further modifications as pigment paste P10.

Pigment Paste P11

[0171] The black pigment paste P11 was prepared in an identical manner as pigment paste P10 except that the milling step—after having added the 0.3-0.4 mm YTZ milling media—was performed for only 2 hours instead of for 12 hours.

Pigment Paste P12

[0172] The black pigment paste P12 is produced by addition of dispersant 3, deionized water and propylene glycol n-propyl ether in a large mixing vessel, mixing well, and then adjusting the pH to 8.1 using a 20 wt.-% dimethyl ethanol amine aqueous solution. To this solution Monarch® 1300 (Cabot) is added in small aliquots under agitation and mixed until homogeneity was achieved. This mixture is then diluted with deionized water and the pH is adjusted again in the same manner as described above to 8.1. The pigment paste is transferred to an Eiger Bead mill (EMI) containing 0.9-1.0 mm beads and milled to an energy of 180 Whr/kg.

TABLE-US-00005 TABLE 4a Pigment pastes P10 to P12 Constituents P10 P11 P12 Black pigment 2   10 g   10 g — Black pigment 3 — —  8.75 g Dispersant 1 14.46 g 14.46 g — Dispersant 3 — — 27.41 g Propylene glycol  2.0 g  2.0 g — n-butyl ether Propylene glycol — —  7.3 g n-propyl ether Deionized water  73.5 g  73.5 g  54.7 g Pigment amount, 62.5 62.5 47.4 based on total solid content [wt.-%]

[0173] As outlined hereinbefore the black pigment 2 present in pigment pastes P10 and P11 is Chromofine® A-1103 (Dainichiseika Chemicals). Black pigment 3 present in pigment paste P12 is Monarch® 1300 (Cabot). Dispersants 1 and 2 have already been explained hereinbefore.

[0174] The pigment pastes P10 to P12 have been analyzed via particle size analysis after their preparation including the milling step. Additionally, their haze has been measured. Both measuring of the haze and measurement of the particle size characteristics indicated in Table 4b have been performed according to the methods disclosed in the ‘Methods’ section. The measured values are indicated in Table 4b.

TABLE-US-00006 TABLE 4b Haze and particle size characteristics of pigment pastes P10, P11 and P12 P10 P11 P12 Haze 4.9 6.5 2.2 Volume average 685.9 2116 96.0 particle size [nm] Z-average 145.3 165.7 127.9 particle size [nm] d.sub.N,10% [nm] 84 101 79.3 d.sub.N,50% [nm] 176 189 140 d.sub.N,90% [nm] 399 357 246

2. Preparation of Aqueous Basecoat Compositions

[0175] A number of aqueous basecoat compositions have been prepared by making use of one of the aqueous pigment pastes P2a and P10 to P12. The constituents listed in Table 5a have been mixed under stirring in a dissolver in the sequence given in said Table to prepare aqueous basecoat compositions WBC2c and WBC10 to WBC12.

[0176] A number of further aqueous basecoat compositions have been prepared by making use of one of the aqueous pigment pastes P1 to P7. The constituents listed in Tables 5 and 6 below have been mixed under stirring in a dissolver in the sequence given in said Tables to prepare aqueous basecoat compositions WBC1 to WBC7 and MWBC0, MWBC2a-d as well as MWBC4a-c. Each of the compositions according to Table 6 was reduced to a (spray) viscosity of 85.0 ±5.0 P by means of deionized water (about 25-75 parts by weight of deionized water).

[0177] The resin blend mixture, to which it is referred to in the following, was prepared as follows: (i) 3.72 parts of Laponite® powder (BYK Chemie) were added slowly to 90.08 parts of deionized water and mixed under high sheer with a Cowles blade for 45 minutes. 3.5 parts Pluracol® P1010 Polyol (BASF) was then added under agitation. Once homogeneity was achieved, the contents are transferred from the mixing container to a storage container and rinsed with 2.7 parts of deionized water.

[0178] (ii) 16.7 parts of the solution described above in (i) was diluted with 8.8 parts of deionized water and then 16.0 parts of a polyurethane resin were added and mixed. (iii) Subsequently, 9.4 parts of an aqueous dispersion of a (meth)acrylic polymer (containing 44 wt.-% resin solids, 54.7 wt.-% deionized water and 1.33 wt.-% dimethyl ethanol amine), 12.34 parts of a mixture of 36.0 wt.-% of Daotan® VTW 6462/36WA (Allnex) and 64.0 wt.-% of deionized water, and 7.41 parts Cymel® 327 (Allnex) were added slowly under agitation. (iv) The resulting resin blend is reduced with 3.3 parts propylene glycol n-butyl ether, followed by introduction of 0.94 parts commercial additives. (v) 10.7 parts of dispersion of a branched polyester containing 42.3 wt.-% of resin solids and 53.7 wt.-% ethylene glycol monobutyl ether and 4.0 wt.-% of an aqueous solution containing dimethyl ethanol amine (20 wt.-%) was then added, followed by addition of 2.3 parts propylene glycol n-butyl ether. (vi) The pH of the resulting mixture is adjusted with an aqueous solution containing dimethyl ethanol amine (20 wt.-%) to 8.1 and the resulting product is used as resin blend mixture.

[0179] The polyurethane, to which it is referred to in the following, is an aqueous mixture containing 27.0 wt.-% polyurethane resin solids, 0.3 wt.-% n-butyl alcohol, 3.9 wt.-% methyl propyl ketone, 4.0 wt.-% n-methyl pyrrolidone and 64.8 wt.-% deionized water.

TABLE-US-00007 TABLE 5a Waterborne basecoat compositions WBC2c and WBC10 to WBC12 Constituents WBC2c WBC10 WBC11 WBC12 Resin blend mixture 215.6 14.17 34.10 34.10 [parts by weight] Polyurethane 48.88 3.21 7.71 4.62 [parts by weight] Deionized water 18.08 1.19 2.88 4.23 [parts by weight] Pigment paste 77.0 5.10 12.25 14.00 [parts by weight] (P2a) (P10) (P11) (P12) Pigment amount, 8.8 8.8 8.8 8.8 based on total solid content [wt.-%]

TABLE-US-00008 TABLE 5 Waterborne basecoat compositions WBC1 to WBC7 Constituents WBC1 WBC2a WBC2b WBC3 WBC4 WBC5a WBC5b WBC6 WBC7 Resin blend mixture 19.5 19.5 19.0 19.5 18.5 19.5 16.0 19.5 19.5 [parts by weight] Polyurethane 0.51 1.24 0.72 1.83 — 0.42 — 1.45 2.52 [parts by weight] Deionized water 0.65 3.17 0.12 6.55 1.09 7.54 5.90 5.92 6.77 [parts by weight] Pigment paste 9.75 (P1) 6.50 (P2b) 10.56 (P2b) 2.54 (P3) 10.83 (P4) 2.95 (P5) 8.47 (P5) 3.54 (P6) 1.63 (P7) [parts by weight] Pigment amount, 13.0 8.8 11.5 9.1 12.1 12.7 29.0 9.0 9.2 based on total solid content [wt.-%]

TABLE-US-00009 TABLE 6 Waterborne basecoat compositions (midcoats) MWBC0, MWBC2a-d and MWBC4a-c Constituents MWBC0 MWBC2a MWBC2b MWBC2c MWBC2d MWBC4a MWBC4b MWBC4c Resin blend mixture 300 300 300 300 300 300 300 300 [parts by weight] Polyurethane 3.35 2.37 1.80 1.29 — 2.17 1.76 0.48 [parts by weight] Pigment paste — 5.61 (P2b) 9.0 (P2b) 11.25 (P2b) 16.86 (P2b) 5.01 (P4) 6.21 (P4) 10.14 (P4) [parts by weight] Pigment amount, 0 0.5 0.8 1.0 1.5 0.4 0.6 0.9 based on total solid content [wt.-%]

3. Preparation of Solventborne Topcoat Compositions

[0180] A number of solventborne topcoat compositions have been prepared by making use of one of solventborne pigment pastes P8 and P9 or without a pigment paste in case of SBCC0 and TC0. The compositions are each 2K-compositions. The pigment paste P8 or P9 has been first mixed under stirring with the “A”-component, namely with E10CG081 G. The resulting mixture was then mixed with the “B”-component, which is a polyisocyanate having free NCO-groups (N52CG081). Both E10CG081 G and N52CG081 are commercially available (as ProGloss® 2K4 from BASF Corporation, Coatings Division, USA). Solventborne topcoat compositions SBCC0, SBCC8a, SBCC8b, SBCC8c, SBCC8d, SBCC9a, SBCC9b, SBCC9c and SBCC9d were obtained in this manner as it is evident from Table 7. The pigment amount indicated is in each case based on the total solid content of components “A” plus “B”.

TABLE-US-00010 TABLE 7 Solventborne topcoat compositions SBCC0, SBCC8a, SBCC8b, SBCC8c, SBCC8d, SBCC9a, SBCC9b, SBCC9c and SBCC9d Constituents SBCC0 SBCC8a SBCC8b SBCC8c SBCC8d SBCC9a SBCC9b SBCC9c SBCC9d “A”-component 146.70 146.70 146.70 146.70 146.70 146.70 146.70 146.70 146.70 [parts by weight] Pigment paste P8 — 1.60 2.60 3.20 4.80 — — — — [parts by weight] Pigment paste P9 — — — — — 1.60 2.60 3.20 4.80 [parts by weight] “B”-component 54.30 54.30 54.30 54.30 54.30 54.30 54.30 54.30 54.30 [parts by weight] Pigment amount, 0 0.10 0.16 0.20 0.30 0.10 0.16 0.20 0.30 based on total solid content [wt.-%]

4. Preparation of Multilayer Coating Systems

4.1 Multilayer Coating Systems Obtained by Making Use of the Tinted Solventborne Topcoat Compositions in a 2C1B-Process

[0181] A steel panel bearing a cured primer coat was used as substrate. Aqueous basecoat WBC1, which was prepared by making use of pigment paste P1 containing an organic black pigment, or an aqueous basecoat WBC11, which was prepared by making use of pigment paste P11 containing an organic black pigment, or an aqueous basecoat WBC12, which was prepared by making use of pigment paste P12 containing a inorganic carbon black pigment, was spray-applied onto the primer coat in an amount that results in a dry film layer thickness of 18 to 20 μm later upon curing. After a flash-off at room temperature (23° C.) for up to 10 minutes one of solventborne topcoat compositions SBCC0, SBCC8a, SBCC8b, SBCC8c, SBCC8d, SBCC9a, SBCC9b, SBCC9c and SBCC9d was spray-applied wet-on-wet onto the uncured basecoat film in an amount that results in a dry film layer thickness of 45 to 55 μm later upon curing. Then, both coating films applied were jointly cured for 30 minutes at 130° C.

4.2 Multilayer Coating Systems Obtained by a 3C1B-Process With Tinted Aqueous Basecoat Compositions Applied as Midcoats

[0182] A steel panel bearing a cured primer coat was used as substrate. Aqueous basecoat WBC1, which was prepared by making use of pigment paste P1 containing a black pigment, was spray-applied onto the primer coat as a first basecoat in an amount that results in a dry film layer thickness of 18 to 20 μm later upon curing. After a flash-off at room temperature (23° C.) for up to 10 minutes, one of aqueous basecoat compositions MWBC0, MWBC2a, MWBC2b, MWBC2c, MWBC2d, MWBC4a, MWBC4b and MWBC4c was spray-applied wet-on-wet as a second basecoat onto the uncured first basecoat film in an amount that results in a dry film layer thickness of 9 to 11 μm later upon curing. In an additional control experiment no such second basecoat was applied, i.e. the first basecoat represents the only basecoat in this 2C1B-control experiment. After a flash-off at room temperature (23° C.) for up to 10 minutes solventborne topcoat composition SBCC0 was spray-applied wet-on-wet as a clearcoat onto each of the uncured second basecoat film or on the first basecoat film in case of the control experiment in amount that results in a dry film layer thickness of 45 to 55 μm later upon curing. Then, all three (or two) coating films applied were jointly cured for 30 minutes at 130° C.

5. Properties of the Substrates Coated With the Multilayer Coating Systems

[0183] 5.1 Each substrate coated with aqueous basecoat WBC1 or WBC11 or WBC12 and subsequently coated with one of solventborne topcoat compositions SBCC0, SBCC8a, SBCC8b, SBCC8c, SBCC8d, SBCC9a, SBCC9b, SBCC9c and SBCC9d as outlined in item 4.1 was subjected to an investigation of its blackness (My) and jetness (Mc) values as well as of its color values L*, a* and b*. Measurement of these values has been performed according to the methods disclosed in the ‘Methods’ section. The measured values are indicated in Tables 8a and 8b and 8c. In addition, each of the coated substrates was additionally visually reviewed (by a human) and graded (grades 1 to 6):

[0184] Grade 5=no or essentially no color position improvement when compared to the control experiment (in this case SBCC0 applied on WBC1, WBC11 or WBC12 as SBCC0 does not contain any pigments and each of WBC1 and WBC11 contains an organic black pigment and WBC12 contains an inorganic carbon black pigment);

[0185] Grade 6=coated substrate no longer appears black due to an overpowering undertone color; and

[0186] Grades 1 to 4=color position improvements when compared to the control experiment with ‘1’ being the most significant improvement.

TABLE-US-00011 TABLE 8a Color, jetness and blackness values of substrates coated with WBC1 and subsequently with a solventborne topcoat, part I SBCC0 SBCC8a SBCC8b SBCC8c SBCC8d applied applied applied applied applied on on on on on WBC1 WBC1 WBC1 WBC1 WBC1 L* 1.98 1.41 1.21 1.14 1.01 a* 0.97 0.09 −0.07 −0.16 −0.16 b* 0.93 −0.19 −0.61 −0.87 −1.15 Mc 247.3 283.2 298.9 307.3 318.6 My 265.8 280.6 287.2 289.9 295 grade 5; 3; 1 1 6; appears appears appears green slightly deeply green green

TABLE-US-00012 TABLE 8b Color, jetness and blackness values of substrates coated with WBC1 and subsequently with a solventborne topcoat, part II SBCC0 SBCC9a SBCC9b SBCC9c SBCC9d applied applied applied applied applied on on on on on WBC1 WBC1 WBC1 WBC1 WBC1 L* 1.98 1.56 1.47 1.47 1.36 a* 0.97 0.76 0.88 1.01 1.63 b* 0.93 −0.92 −1.85 −2.46 −4.03 Mc 247.3 284.4 297 301.8 314.8 My 265.8 276.2 278.9 278.8 282.1 grade 5; 3; 6; 6; 6; appears neutral appears appears appears green blue blue blue

TABLE-US-00013 TABLE 8c Color, jetness and blackness values of substrates coated with WBC11 or WBC12 and subsequently with a solventborne topcoat SBCC0 SBCC8d SBCC0 SBCC8d applied applied applied applied on on on on WBC11 WBC11 WBC12 WBC12 L* 3.3 1.68 1.18 0.8 a* 2.41 −0.52 −0.1 0 b* 0.44 −2.18 −0.73 −1.37 Mc 233.4 300.7 302.4 335.1 My 243.7 273.1 288.3 305.2 grade 6; 2; 1; 2; appears appears appears appears grainy slightly slightly blue red/brown blue yellow

[0187] 5.2 Each substrate coated with aqueous basecoat WBC1 as first basecoat, subsequently coated with one of aqueous basecoat compositions MWBC0, MWBC2a, MWBC2b, MWBC2c, MWBC2d, MWBC4a, MWBC4b and MWBC4c as second basecoat and subsequently coated with solventborne topcoat composition SBCC0 as clearcoat as outlined in item 4.2 was subjected to an investigation of its blackness (My) and jetness (Mc) values as well as of its color values L*, a* and b*. Measurement of these values has been performed according to the methods disclosed in the ‘Methods’ section. The measured values are indicated in Tables 9a and 9b. In addition, each of the coated substrates was additionally visually reviewed (by a human) and graded (grades 1 to 6):

[0188] Grade 5=no or essentially no color position improvement when compared to the control experiment (in this case SBCC0 applied on MWBC0 applied on WBC1 as neither SBCC0 nor MWBC0 does contain any pigments and WBC1 contains an organic black pigment);

[0189] Grade 6=coated substrate no longer appears black due to an overpowering undertone color; and

[0190] Grades 1 to 4=color position improvements when compared to the control experiment with ‘1’ being the most significant improvement.

TABLE-US-00014 TABLE 9a Color, jetness and blackness values of substrates coated with WBC1, subsequently with a further aqueous basecoat and subsequently with SBCC0, part I SBCC0 SBCC0 SBCC0 SBCC0 SBCC0 SBCC0 applied on applied on applied on applied on applied on applied on WBC1 MWBC0 MWBC2a MWBC2b MWBC2c MWBC2d (no second applied on applied on applied on applied on applied on basecoat) WBC1 WBC1 WBC1 WBC1 WBC1 L* 1.98 2.1 1.69 1.55 1.59 1.72 a* 0.97 0.89 0.29 0.4 0.42 0.56 b* 0.93 1.02 −0.52 −1.03 −1.23 −0.58 Mc 247.3 244.8 278.2 288.3 289 276.6 My 265.8 263.4 272.2 276.6 275.5 272 grade 5; 5; 4 6; 6; 6; appears appears appears appears appears green green blue blue blue

TABLE-US-00015 TABLE 9b Color, jetness and blackness values of substrates coated with WBC1, subsequently with a further aqueous basecoat and subsequently with SBCC0, part II SBCC0 SBCC0 SBCC0 SBCC0 SBCC0 applied on applied on applied on applied on applied on WBC1 MWBC0 MWBC4a MWBC4b MWBC4c (no second applied applied on applied on applied on basecoat) on WBC1 WBC1 WBC1 WBC1 L* 1.98 2.1 1.69 1.57 1.48 a* 0.97 0.89 0.66 0.77 0.95 b* 0.93 1.02 −1.26 −1.69 −2.4 Mc 247.3 244.8 284.5 292.4 301.5 My 265.8 263.4 272.7 276.1 278.7 grade 5; 5; 3; 2; 6; appears appears appears appears appears green green slightly blue blue green

6. Comparative Experimental Data

[0191] Further comparative experiments have been carried out in view of and in line with the disclosure of WO 2012/170230 A1:

[0192] Aqueous basecoat compositions containing a black pigment and a further additional pigment have been prepared by making blends of basecoat composition WBC1 (containing pigment paste P1, which in turn contains an organic black pigment) or WBC10 and one of basecoat compositions WBC2a or WBC2c (containing pigment paste P2b or P2a), WBC3 (containing pigment paste P3), WBC4 (containing pigment paste P4), WBC5a and WBC5b (each containing pigment paste P5) and WBC6 and WBC7 (containing pigment paste P6 or P7). In other words, basecoat compositions have been prepared which contain both a black pigment (from P1) and a further pigment (from P2b, P2a, P3 and P5 to P7) in one and the same basecoat composition.

[0193] The constituents listed in Tables 10 to 13, 13a and 13b below have been mixed under stirring in a dissolver in the sequence given in said Tables to prepare the aqueous basecoat composition blends as indicated therein. Tables 10 to 12 represent a first run of experiments. Tables 13, 13a as well as 13b represent a second experimental run. Basecoat composition blends B1 to B56 have been obtained in this manner.

[0194] A number of additional aqueous basecoat compositions have been prepared by making use of the aqueous pigment paste P11 alone or together with pigment paste P2a. The constituents listed in Table 13c have been mixed under stirring in a dissolver in the sequence given in said Table to prepare aqueous basecoat compositions RWBC1 to RWBC5.

[0195] Multilayer coating systems have then been obtained by a 2C1B-process with these aqueous basecoat composition blends according to WO 2012/170230 A1: A steel panel bearing a cured primer coat was used as substrate. Aqueous basecoat WBC1 or WBC10 or one of blends B1 to B56 or one of RWBC1 to RWBC5 was spray-applied onto the primer coat as a basecoat in an amount that results in a dry film layer thickness of 18 to 20 μm later upon curing. After a flash-off at room temperature (23° C.) for up to 10 minutes solventborne topcoat composition SBCC0 or TC0 was spray-applied wet-on-wet as a clearcoat onto each of the uncured basecoat films in amount that results in a dry film layer thickness of 45 to 55 μm later upon curing. Then, both coating films applied were jointly cured for 30 minutes at 130° C. in each case.

[0196] Each coated substrate coated was then subjected to an investigation of its blackness (My) and jetness (Mc) values as well as of its color values L*, a* and b*. Measurement of these values has been performed according to the methods disclosed in the ‘Methods’ section. The measured values are indicated in Tables 14 to 18. In addition, each of the coated substrates was additionally visually reviewed (by a human) and graded (grades 1 to 6).

[0197] Grade 5=no or essentially no color position improvement when compared to the control experiment (in this case SBCC0 applied on WBC1 or WBC10 as SBCC0 does not contain any pigments and WBC1 contains a black organic pigment);

[0198] Grade 6=coated substrate no longer appears black due to an overpowering undertone color; and

[0199] Grades 1 to 4=color position improvements when compared to the control experiment with ‘1’ being the most significant improvement.

TABLE-US-00016 TABLE 10 Waterborne basecoat compositions blends B1 to B15 Constituents WBC1 B1 B2 B3 B4 B5 B6 B7 B8 B9 B10 B11 B12 B13 B14 B15 WBC1 [pbw] 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 WBC2a [pbw] — 0.2 2 5 10 — — — — — — — — — — — WBC3 [pbw] — — — — — 0.2 2 5 10 — — — — — — — WBC5a [pbw] — — — — — — — — — 5 10 20 30 40 50 60 WBC5b [pbw] — — — — — — — — — — — — — — — — WBC6 [pbw] — — — — — — — — — — — — — — — — WBC7 [pbw] — — — — — — — — — — — — — — — — Pigment amount* 13.0 13.0 12.6 12.2 11.6 13.0 12.6 12.2 11.7 12.9 12.9 12.9 12.8 12.8 12.8 12.8 Pigment amount 13.0 12.9 11.8 10.4 8.7 12.9 11.8 10.4 8.7 10.4 8.7 6.5 5.2 4.3 3.7 3.3 (black pigment only)* *based on the total solid content [wt.-%]

TABLE-US-00017 TABLE 11 Waterborne basecoat compositions blends B16 to B31 Constituents B16 B17 B18 B19 B20 B21 B22 B23 B24 B25 B26 B27 B28 B29 B30 B31 WBC1 [pbw] 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 WBC2a [pbw] — — — — — — — — — — — — — — — — WBC3 [pbw] — — — — — — — — — — — — — — — — WBC5a [pbw] 70 80 200 — — — — — — — — — — — — — WBC5b [pbw] — — — — 2 10 20 30 40 50 60 80 100 — — — WBC6 [pbw] — — — — — — — — — — — — — 0.2 2 5 WBC7 [pbw] — — — — — — — — — — — — — — — — Pigment amount* 12.8 12.8 12.7 13.0 14.5 18.3 21.0 22.6 23.7 24.4 25.0 25.8 26.3 13.0 12.6 12.2 Pigment amount 2.9 2.6 1.2 1.3 11.8 8.7 6.5 5.2 4.3 3.7 3.3 2.6 2.2 12.9 11.8 10.4 (black pigment only)* *based on the total solid content [wt.-%]

TABLE-US-00018 TABLE 12 Waterborne basecoat compositions blends B32 to B36 Constituents B32 B33 B34 B35 B36 WBC1 [pbw] 20 20 20 20 20 WBC2a [pbw] — — — — — WBC3 [pbw] — — — — — WBC5a [pbw] — — — — — WBC5b [pbw] — — — — — WBC6 [pbw] 10 — — — — WBC7 [pbw] — 0.2 2 5 10 Pigment amount* 11.7 13.0 12.7 12.2 11.7 Pigment amount 8.7 12.9 11.8 10.4 8.7 (black pigment only)* *based on the total solid content [wt.-%]

TABLE-US-00019 TABLE 13 Waterborne basecoat compositions blends B37 to B46 Constituents WBC1 B37 B38 B39 B40 B41 B42 B43 B44 B45 B46 WBC1 [pbw] 20 20 20 20 20 20 20 20 20 20 20 WBC2a [pbw] — 0.2 1 2 4 6 8 10 20 — — WBC4 [pbw] — — — — — — — — — 0.2 1 Pigment amount* 13.0 13.0 12.9 12.8 12.7 12.5 12.4 12.3 12.0 13.0 13.0 Pigment amount 13.0 12.9 12.4 11.8 10.8 10.0 9.3 8.7 6.5 12.9 12.4 (black pigment only)* *based on the total solid content [wt.-%]

TABLE-US-00020 TABLE 13a Waterborne basecoat compositions blends B47 to B52 Constituents B47 B48 B49 B50 B51 B52 WBC1 [pbw] 20 20 20 20 20 20 WBC2a [pbw] — — — — — — WBC4 [pbw] 2 4 6 8 10 20 Pigment amount* 12.9 12.8 12.8 12.7 12.7 12.5 Pigment amount 11.8 10.8 10.0 9.3 8.7 6.5 (black pigment only)* *based on the total solid content [wt.-%]

TABLE-US-00021 TABLE 13b Waterborne basecoat compositions blends B53 to B56 Constituents B53 B54 B55 B56 WBC10 [pbw] 3.6 3.6 3.6 3.6 WBC2c [pbw] — 3.6 18.0 36.0 Pigment amount* 8.8 8.8 8.8 8.8 Pigment amount 8.8 4.4 1.5 0.8 (black pigment only)* *based on the total solid content [wt.-%]

TABLE-US-00022 TABLE 13c Waterborne basecoat compositions RWBC1 to RWBC5 Constituents RWBC1 RWBC2 RWBC3 RWBC4 RWBC5 Resin blend mixture 13.89 13.89 13.89 13.89 13.89 [parts by weight Polyurethane 3.15 3.15 3.15 3.15 3.15 [parts by weight] Deionized water 1.16 1.16 1.16 1.16 1.16 [parts by weight] Pigment paste P10 5.1 5.1 5.1 5.1 5.1 [parts by weight] Pigment paste P2a — 2.65 5.10 10.2 15.3 [parts by weight] Pigment amount, 8.8 12.5 15.4 20.6 24.7 based on total solid content [wt.-%] Pigment amount 8.8 8.2 7.7 6.9 6.2 (black pigment only), based on total solid content [wt.-%]

TABLE-US-00023 TABLE 14 Color, jetness and blackness values of substrates coated with WBC1 or one of B1 to B13 and subsequently coated with SBCC0 WBC1 B1 B2 B3 B4 B5 B6 B7 B8 B9 B10 B11 B12 B13 L* 1.69 1.7 1.71 1.68 1.65 1.74 1.75 1.87 1.85 1.94 2.04 2.25 2.42 2.56 a* 1.23 0.74 0.23 0.21 0.12 0.49 0.31 0.21 0.27 1.26 1.28 1.26 1.23 1.24 b* 1.05 0.79 0.58 0.34 0.06 0.74 0.62 0.54 0.32 0.97 0.94 0.82 0.66 0.49 Mc 246.3 251.4 255.7 259.6 264.9 252.8 254.7 254.6 257.5 243.7 242.8 241.4 240.3 240.3 My 264.0 263.4 263.2 263.5 265 263 262.6 260.6 261 257.2 255.5 252 249.3 249.3 grade 5; 5; 5; 3; 4; 5; 5; 4; 5; 5; 5; 5; 4; 4; green green green neutral blue green green, grainy, grainy green green grainy, grainy, grainy, grainy green- green green- bluish ish ish

TABLE-US-00024 TABLE 15 Color, Mc and My values of substrates coated with WBC1 or one of B14 or B19 to B27 and subsequently coated with SBCC0 B14 B19 B20 B21 B22 B23 B24 B25 B26 B27 L* 2.72 2.04 2.2 2.49 3.24 3.7 4.15 4.66 4.94 5.77 a 1.25 0.81 0.68 0.88 0.6 0.67 0.58 0.38 0.22 −0.01 b* 0.38 0.93 0.81 0.75 0 −0.55 −1.17 −1.9 −2.68 −4.49 Mc 239 244.1 244.5 240.1 238.1 236.2 234.8 233.4 233.9 232.1 My 245 255 252.6 248.1 238.6 233.6 229.1 224.6 222.2 215.8 grade 5; 5; 5; 4; 4; 5; 6; 6; blue 6; blue 6; blue grainy green green grainy, grainy, grainy, blue green- bluish blue ish

TABLE-US-00025 TABLE 16 Color, Mc and My values of substrates coated with WBC1 or one of B28 to B36 and subsequently coated with SBCC0 B28 B29 B30 B31 B32 B33 B34 B35 B36 L* 6.29 1.74 2.27 2.74 3.65 1.75 2.03 2.34 3.1 a* −0.15 1.27 0.78 0.09 −1.18 1.28 1 0.66 −0.03 b* −5.83 0.97 0.44 0.08 0.01 1.07 1.64 1.47 2.09 Mc 231.8 246.6 247.4 245.6 237.8 244.8 238.5 233.2 221.5 My 212.3 262.6 252.6 245.2 234.1 262.3 256.1 249.7 238.8 grade 6; 4; 5; 6; 6; 4; 5; 5; 6; blue green green green grainy, green green green grainy, green green

TABLE-US-00026 TABLE 17 Color, jetness and blackness values of substrates coated with WBC1 or one of B37 to B49 and subsequently coated with SBCC0 WBC1 B37 B38 B39 B40 B41 B42 B43 B44 B45 B46 B47 B48 B49 L* 1.98 1.9 1.9 1.87 1.81 1.75 1.71 1.66 1.55 1.96 1.88 1.9 1.83 1.81 a* 0.97 0.57 0.2 0.07 −0.13 −0.16 −0.19 −0.22 −0.18 0.3 0.11 −0.12 −0.3 −0.39 b* 0.93 0.63 0.47 0.34 0.16 −0.05 −0.19 −0.28 −0.79 0.57 0.45 0.37 0.18 0.01 Mc 247.3 255.5 259.9 263.2 268.2 272.8 276.2 279.2 288.8 256.9 261 263.2 268.5 272.2 My 265.8 267.7 267.7 268.4 269.8 271.3 272.2 273.7 276.5 266.4 268.1 267.7 269.4 269.9 grade 5; 5; 5; 5; 5; 5; 5; 4; 5; 5; 5; 5; 5; 5; green green green green green green green bluish grainy green green green green green- blue ish

TABLE-US-00027 TABLE 18 Color, jetness and blackness values of substrates coated with one of B50 to B52 and subsequently coated with SBCC0 B50 B51 B52 L* 1.76 1.71 1.57 a* −0.51 −0.57 −0.63 b* −0.08 −0.16 −0.57 Mc 275.2 278 288.4 My 271.1 272.2 276 grade 4; 5; 5; neutral deep bluish green green

TABLE-US-00028 TABLE 19 Color, jetness and blackness values of substrates coated with one of B53 to B56 and subsequently coated with TC0 B53 B54 B55 B56 L* 1.49 1.33 1.21 1.27 a* 1.1 0.94 1.62 2.14 b* 0.08 −0.92 −2.92 −4.19 Mc 269.9 291.31 313.6 317.4 My 278.2 283.2 287.3 285.3 grade 4; 5; 6; 6; reddish blue, blue, blue, grainy grainy grainy

TABLE-US-00029 TABLE 20 Color, jetness and blackness values of substrates coated with one of RWBC1 to RWBC5 and subsequently coated with TC0 RWBC1 RWBC2 RWBC3 RWBC4 RWBC5 L* 1.49 1.29 1.21 1.12 1.02 a* 1.1 0.74 0.68 0.6 0.57 b* 0.08 −0.41 −0.67 −1 −1.19 Mc 269.9 286.5 294 303.6 311.9 My 278.2 284.6 287.2 290.6 294.8 grade 4; 5; 6; 6; 6; reddish red/purple, blue, blue, blue, grainy grainy grainy grainy

[0200] It can be seen that blends of pigments as present in basecoat composition blends B1 to B14 and B19 to, B53 to B56, RWBC1 to RWBC5 and as disclosed in WO 2012/170230 A1 may in principle be able to increase jetness (Mc); however, this does not apply generally in all cases as can be seen when comparing B9 to B14 and B19 to B28 and B31 to B36 to WBC1 of the first run of experiments. Increased jetness was e.g. observed when comparing the coated substrate prepared by making use of blend B52 to a coated substrate prepared by making use of WBC1 of the second run of experiments (Mc =288.4 vs. Mc =247.3). However, the visual appearance (color) of this coating system was still inferior compared to a system prepared from a basecoat containing carbon black (not shown).

[0201] Moreover, for preparing blend B52 aqueous basecoat WBC4 has been used, which contains low-haze pigment paste P4, which in turns contains blue pigment 2. When the same paste P4 is used to prepare a midcoat to be used as additional second aqueous basecoat composition in a 3C1B process—namely MWBC4b—slightly better jetness values were observed compared to using the blend, namely B52, in a 2C1B-process (Mc =292.4 for the system obtained by making use of MWBC4b vs. Mc =288.4 for B52). However, in particular the visual appearance of the coating system obtained by making use of MWBC4b is surprisingly far superior compared to the system obtained by making use of B52 as the b*-value, obtained by making use of MWBC4b, was more negative (grades 2 vs. 5 and b*=−1.69 vs. b*=−0.57) leading to an overall more bluish impression. In addition, also the dM (undertone) value is better for the MWBC4b system as the blackness (My) value in both cases is about the same.

[0202] Even greater increases in jetness and in visual appearance were obtained by using a tinted clearcoat in a 2C1B-process (cf. item 5.1).