Coating system

Abstract

A coating formed on a substrate is provided which coating comprises (a) an organic NIR-transparent pigment and/or an inorganic NIR-reflective pigment; (b) a dye having a transmittance of at least 75% in the range of from 700 to 2500 nm; and (c) optionally an effect pigment; wherein said coating exhibits a total solar reflectance (TSR) of (i) 40%, if 60<L*<100, or (ii) 30%, if 30<L*60, or (iii) 20%, if 0<L*30, wherein L* is the lightness. The coating is suitable for an exterior-use coating like an industrial coating or a coating for vehicles, especially an automotive finish, having improved jetness.

Claims

1. A coating formed on a substrate, the coating comprising a primer, a basecoat layer and a clearcoat layer, wherein: the basecoat layer comprises: a polymeric binder; (a) a pigment comprising a near infrared transparent organic pigment; (b) a dye having a transmittance of at least 75% in the range of from 700 to 2500 nm; and (c) an effect pigment selected from the group consisting of a metal oxide-coated metal pigment, a coated mica pigment, a coated glass flake, and a mixture thereof; the primer comprises a near infrared reflective inorganic pigment; the basecoat layer and the clearcoat layer do not contain a near infrared reflective inorganic pigment; an outer surface of the basecoat layer is directly overcoated by the clearcoat layer; the clearcoat layer does not contain a dye; the coating exhibits a total solar reflectance (TSR) of (i) 40%, if 60 <L* <100, or (ii) 30%, if 30 <L* 60, or (iii) 20%, if 0 <L* 30; L* is a lightness; and the coating is suitable for an exterior-use industrial coating or an automotive coating.

2. The coating according to claim 1, wherein the coating exhibits the TSR of (i) 45%, if 60 <L* <100, or (ii) 35%, if 30 <L* 60, or (iii) 25%, if 0 <L* 30.

3. The coating according to claim 1, wherein an amount of the dye (b) is from 0.01 to 10.0% by weight, based on a total weight of the pigment (a).

4. The coating according to claim 1, wherein an amount of the effect pigment (c) is from 0.1 to 60% by weight, based on a total weight of the pigment (a).

5. The coating according to claim 1, wherein the pigment (a) comprises a near infrared transparent organic pigment selected from the group consisting of Color Index (C. I.) Pigment Yellow 110, 139, 151; C.I. Pigment Orange 69, 73; C.I. Pigment Red 122, 179, 202, 254, 282; C.I. Pigment Brown 29; C.I. Pigment Violet 19; C.I. Pigment Blue 15:1, 15:2, 15:3, 15:4, 15:6, 60; C.I. Pigment Green 7, 36; C.I. Pigment Black 31, 32; a perylene pigment comprising an isomer of formula Ia' or Ib' or a mixture thereof, ##STR00004## in which R.sup.1 and R.sup.2 are the same and are unsubstituted phenylene or naphthylene; and a pigment preparation thereof.

6. The coating according to claim 1, wherein the pigment (a) comprises a near infrared reflective inorganic pigment selected from the group consisting of C.I. Pigment Yellow 53, 184, C.I. Pigment Brown 24, 29. 33, 35, C.I. Pigment Blue 28. 36, C.I. Pigment Green 17, 26, 50, C.I. Pigment Black 12, 30 and a pigment preparation thereof.

7. The coating according to claim 1, wherein the substrate is a metallic substrate.

8. The coating according to claim 1, wherein: the basecoat layer comprises one or two layers.

9. The coating according to claim 8, wherein the primer comprises a white pigment.

10. The coating according to claim 1, comprising: (a) a perylene pigment; (b) a dye selected from the group consisting of C. I. Solvent Black 27, 28 and 29; and (c) the effect pigment, wherein the coating exhibits the TSR of at least 20% and L* is 30.

11. The coating according to claim 10, wherein the coating exhibits the TSR of at least 25%, and L* is 20.

12. The coating according to claim 1, wherein the dye (b) is selected from the group consisting of an azo dye, an azomethine dye, a xanthene dye, an anthrachinone dye, a metal complex dye, a phthalocyanine dye, and a mixture thereof.

13. The coating according to claim 1, wherein: the near infrared transparent organic pigment is selected from the group consisting of Color Index (C.I.) Pigment Yellow 110, 139, 151; C.I. Pigment Orange 69, 73; C.I. Pigment Red 122, 179, 202, 254, 282; C.I. Pigment Brown 29; C.I. Pigment Violet 19; C.I. Pigment Blue 15:1, 15:2, 15:3, 15:4, 15:6, 60; C.I. Pigment Green 7, 36; C.I. Pigment Black 31, 32; a perylene pigment comprising an isomer of formula Ia' or Ib' or a mixture thereof, ##STR00005## in which R.sup.1 and R.sup.2 are the same and are unsubstituted phenylene or naphthylene; and a pigment preparation thereof; the near infrared reflective inorganic pigment is selected from the group consisting of C.I. Pigment Yellow 53, 184, C.I. Pigment Brown 24, 29, 33, 35, C.I. Pigment Blue 28, 36, C.I. Pigment Green 17, 26, 50, C.I. Pigment Black 12, 30 and a pigment preparation thereof; and the dye (b) is selected from the group consisting of an azo dye, an azomethine dye, a xanthene dye, an anthrachinone dye, a metal complex dye, a phthalocyanine dye, and a mixture thereof.

14. The coating according to claim 1, wherein: an amount of the dye (b) is from 0.01 to 10.0% by weight, based on a total weight of the pigment (a); and an amount of the effect pigment (c) is from 0.1 to 60% by weight, based on the total weight of the pigment (a).

15. The coating according to claim 1, wherein: the pigment (a) comprises a near infrared transparent organic pigment which is at least one selected from the group consisting of a perylene pigment, a phthalocyanine pigment, a diketopyrrolopyrrole pigment, an indigo pigment, a thioindigo pigment, an anthrachinone pigment, an indanthrone pigment, an azo pigment, a d sazo condensation pigment, an isoindoline pigment, an isoindolinone pigment, a quinacridone pigment, a benziniidazolone pigment, a pyrazolochinazolone pigment, a perinone pigment, a dioxazine pigment, and a pigment preparation thereof; and the dye (b) is at least one selected from the group consisting of an azo dye, an azomethine dye, a xanthene dye, an anthrachinone dye, a metal complex dye, and a phthalocyanine dye.

16. The coating according to claim 15, wherein: an amount of the dye (b) is from 0.01 to 10.0% by weight, based on a total weight of the pigment (a), and an amount of the effect pigment (c) is from 0.1 to 60% by weight, based on a total weight of the pigment (a).

17. The coating according to claim 1, wherein the effect pigment is a coated mica pigment.

18. A method for improving the jetness of a coating exhibiting a TSR of (i) 40%, if 60 <L* <100, or (ii)30%, if 30 <L* 60, or (iii)20%, if 0 <L* 30, wherein L* is a lightness, the method comprising: including, in the coating, a polymeric binder, (a) a pigment comprising a near infrared transparent organic pigment, (b) a dye having a transmittance of at least 75% in the range of from 700 to 2500 nm, (c) and an effect pigment selected from the group consisting of, a metal oxide-coated metal pigment, a coated mica pigment, a coated glass flake, and a mixture thereof, wherein: the coating comprises a primer, a basecoat layer and a clearcoat laver; the basecoat layer comprises the polymeric binder, the pigment (a), the dye (b) and the effect pigment (c); the primer comprises a near infrared reflective inorganic pigment; the basecoat layer and the clearcoat layer do not contain a near infrared reflective inorganic pigment; an outer surface of the basecoat layer is directly overcoated by the clearcoat layer; the clearcoat layer does not contain a dye; and the coating is suitable for an exterior-use industrial coating or an automotive coating.

19. The coating according to claim 11, wherein L* is 15.

20. A method for coating a surface of a substrate, the method comprising: applying, to a surface of a substrate, a primer; applying, to a surface of the primer, a coating composition comprising a polymeric binder, (a) a pigment comprising a near infrared transparent organic pigment, (b) a dye having a transmittance of at least 75% in the range from 700 to 2500 nm, and (c) an effect pigment selected from the group consisting of a metal oxide-coated metal pigment, a coated mica pigment, a coated glass flake, and a mixture thereof; optionally removing a solvent to form a basecoat layer; and then applying, to a surface of the basecoat layer, a clearcoat layer, to obtain a coating which exhibits a total solar reflectance (TSR) of (i) 40%, if 60 <L* <100, or (ii) 30%, if 30 <L*60, or (iii) 20%, if 0 <L* 30, wherein: L* is a lightness; the primer comprises a near infrared reflective inorganic pigment; the basecoat layer and the clearcoat layer do not contain a near infrared reflective inorganic pigment; an outer surface of the basecoat layer is directly overcoated by the clearcoat layer; the clearcoat layer does not contain a dye.

Description

EXAMPLES

(1) L*a*b* color measurements are made using Delta Color Spectraflash 600. TSR measurements are made using UV-VIS-NIR-Spectrometer, Varian Cary 5000.

(2) The following blends of colorants are incorporated into a conventional medium-solids basecoat composition (cellulose acetate butyrate (CAB), melamine/polyethylene (PE) and n-butyl acetate). The resulting coating composition (colorant/binder weight ratio is 0.18) is applied by spray-coating and drying by room temperature to yield a thickness of the coating of from 10-15 m. An alu panel coated with a primer comprising a white pigment is used as the substrate. The basecoat is overcoated by a 1K clearcoat of a thickness of about 40 m.

Example 1

(3) 4.90 parts MagnaPearl 3103 (mica coated with titanium dioxide) 4.90 parts Heliogen Blue L 6960 (C.I. Pigment Blue 15:2) 22.06 parts Paliogen Black EH 0788 (a perylene pigment) 66.18 parts Paliogen Black L 0086 (C.I. Pigment Black 32) 1.96 parts Neozapon Black X55 (=Orasol Black X55) (C.I. Solvent Black 29)

Example 2

(4) 4.81 parts MagnaPearl 3103 4.81 parts Heliogen Blue L 6960 21.63 parts Paliogen Black EH 0788 64.90 parts Paliogen Black L 0086 3.84 parts Neozapon Black X55

Example 3

(5) 4.72 parts MagnaPearl 3103 4.72 parts Heliogen Blue L 6960 21.22 parts Paliogen Black EH 0788 63.68 parts Paliogen Black L 0086 5.66 parts Neozapon Black X55

Comparative Example 1

(6) 5 parts MagnaPearl 3103 5 parts Heliogen Blue L 6960 22.5 parts Paliogen Black EH 0788 67.5 parts Paliogen Black L 0086

(7) TABLE-US-00001 TABLE 1 L* TSR (%) Comparative Example 1 Reference L* = 9.4 25 Example 1 0.9 25 Example 2 1.5 25 Example 3 2.5 25

(8) The values of the resulting L* demonstrates the improved jetness of the black coatings compared to coatings without a dye. According to the L*a*b* color space (also referred to as CIELAB) L* indicates lightness and a* and b* are the chromaticity coordinates. A lower L* value means a greater level of jetness. A visual difference of L*0.3 may be recognized by a person skilled in the art as an improvement.

Example 4

(9) The following blend of colorants is incorporated in a conventional medium-solids basecoat composition (CAB, melamine/PE, n-butyl acetate).

(10) The resulting coating composition (colorant/binder weight ratio is 0.18) is applied by spray-coating and drying at room temperature to yield a thickness of the coating of from 10-15 m. 33.3 parts Paliogen Black EH 0788 66.7 parts Paliogen Black L 0086

(11) A clearcoat composition (one-component acrylic clearcoat) containing 1 wt.-% of Neozapon Black X55 is applied on the base coat by spray-coating (wet-on-wet) and drying at 130 C. for 1 hour (thickness about 40 m).

Comparative Example 2

(12) 33.3 parts Paliogen Black EH 0788 66.7 parts Paliogen Black L 0086

(13) A clear coat without a dye is applied onto the base coat.

Comparative Example 3

(14) A clear coat without a dye but with 1% by weight of Heliogen Blue L 6960 is applied onto the base coat.

(15) TABLE-US-00002 TABLE 2 L* TSR (%) Comparative Example 2 Reference L* = 9.4 26 Comparative Example 3 0 26 Example 4 6.2 25

(16) The difference of lightness of 6.2 demonstrates a highly improved jetness compared to a coating without any dye. The presence of a NIR transparent pigment has no influence on the jetness.

Example 5

(17) The following blend of colorants is incorporated in a conventional medium-solids basecoat composition (CAB, melamine/PE, n-butyl acetate).

(18) The resulting coating composition (colorant/binder weight ratio is 0.18) is applied by spray-coating and drying at room temperature to yield a thickness of the coating of from 10-15 m. 50 parts of Lumina Pearl Radiance 1303D (TiO.sub.2 coated mica pigment) 24.9 parts of Heliogen Blue L 6905 (C.I. Pigment Blue 15:2) 24.9 parts of Heliogen Blue L 6950 (C.I. Pigment Blue 15:1) 0.2 parts of Orasol Blue 855 (Solvent Blue 70).

Example 6

(19) The following blend of colorants is incorporated into a conventional medium-solids basecoat composition (cellulose acetate butyrate (CAB), melamine/polyethylene (PE) and n-butyl acetate) The resulting coating composition (colorant/binder weight ratio is 0.18) is applied by spray-coating and drying by room temperature to yield a thickness of the coating of from 10-15 m. The coating has a brilliant blue color. 50 parts of Lumina Pearl Radiance 1303D 25 parts of Heliogen Blue L 6905 25 parts of Heliogen Blue L 6950

(20) A clearcoat composition containing 0.2 wt.-% of Orasol Blue 855, based on 100 wt.-% of the clearcoat composition, is applied on the basecoat by spray-coating and drying at 130 C. for 1 hour (thickness about 40 m).

Comparative Example 4

(21) Example 6 is repeated with the exception that the following blend of colorants is used 50 parts of Lumina Pearl Radiance 1303D 25 parts of Heliogen Blue L 6905 25 parts of Heliogen Blue L 6950

(22) TABLE-US-00003 TABLE 3 L* C* TSR (%) Comparative Ex. 4 Reference L* = 40.8 C* = 46.8 38 Example 5 0.7 0.4 38 Example 6 2.9 1.7 37

(23) The effect of improved jetness and improved chroma can be demonstrated for a blue-colored coating, wherein the effect of in a tinted clearcoat is more significant.

(24) The chroma of the chromatic coating can also be improved. A visual difference of C*0.3 may be recognized by a person skilled in the art.

Example 7

(25) Example 6 is repeated with the exception that the following blend of colorants is used in the basecoat: 50 parts of Stapa Metallux 3560 (aluminum pigment) 25 parts of Heliogen Blue L 6905 25 parts of Heliogen Blue L 6950

(26) A clearcoat composition containing 0.2 wt.-% of Orasol Blue 855, based on 100 wt.-% of the clearcoat composition, is applied on the basecoat by spray-coating and drying at 130 C. for 1 hour (thickness about 40 m).

Comparative Example 5

(27) Example 5 is repeated with the exception that the following blend of colorants is used: 50 parts of Stapa Metallux 3560 25 parts of Heliogen Blue L 6905 25 parts of Heliogen Blue L 6950

(28) TABLE-US-00004 TABLE 4 L* C* TSR (%) Comparative Ex. 5 Reference L* = 69.7 C* = 52.8 41 Example 7 7.8 9.1 41

Comparative Example 6

(29) Comparative Example 1 is repeated with the exception that the following blend of colorants is incorporated into a conventional medium-solids basecoat composition. 22.8 parts Paliogen Black L 0086 8.5 parts Heliogen Green L 8735 (C.I. Pigment Green 7) 50 parts Sicopal Black L 0095 (C.I. Pigment Brown 29) 18.7 parts Cromophtal Violet GT (C.I. Pigment Violet 23)

(30) The TSR value of said hazy dark coating is 28.4 and L* is 9.5.

Example 8

(31) Example 1 is repeated with the exception that the following blend of colorants is incorporated into a conventional medium-solids basecoat composition. 21.92 parts Paliogen Black L 0086 8.17 parts Heliogen Green L8735 48.08 parts Sicopal Black K 0095 17.98 parts Cromophtal Violet GT 3.85 parts Neozapon Black X55

(32) A brilliant black coating exhibiting a TSR of 28.4 and improved jetness, i.e. a lowered L*, is obtained.