COATINGS FOR INCREASING NEAR-INFRARED DETECTION DISTANCES

• US 20180120435A1
• Filed: 10/27/2017
• Published: 05/03/2018
• Est. Priority Date: 10/28/2016
• Status: Active Grant

• Current Assignee: PPG Industries Ohio Incorporated (Nouryon BV)
• Original Assignee: PPG Industries Ohio Incorporated (Nouryon BV)
• Inventors: Decker, Eldon L., Kruszewski, Kristen, Holsing, LuAnn, McQuown, Stephen G., Hellring, Stuart D.
• Granted Patent: US 10,215,855 B2
• Time in Patent Office: Days
• CPC Class Codes: B32B 33/00 Layered products characterised by particular properties or particular surface features, e.g. particular surface coatings; Layered products designed for particular purposes not covered by another single class
• CPC Class Codes: C09D 17/003 containing an organic pigment process features in the making of dye stuff preparations C09B67/00
• CPC Class Codes: C09D 17/006 Metal
• CPC Class Codes: C09D 17/007 Metal oxide
• CPC Class Codes: C09D 17/008 Titanium dioxide
• CPC Class Codes: C09D 5/004 Reflecting paints; Signal paints
• CPC Class Codes: C09D 5/38 Paints containing free metal not provided for above in groups C09D5/00 - C09D5/36
• CPC Class Codes: C09D 7/41 Organic pigments; Organic dyes
• CPC Class Codes: C09D 7/70 characterised by shape, e.g. fibres, flakes or microspheres
• CPC Class Codes: C25D 13/00 Electrophoretic coating characterised by the process C25D15/00 takes precedence; compositions for electrophoretic coating C09D5/44
• CPC Class Codes: G01S 17/08 for measuring distance only indirect measurement G01S17/46; active triangulation systems G01S17/48
• CPC Class Codes: G01S 17/931 of land vehicles
• CPC Class Codes: G01S 7/481 Constructional features, e.g. arrangements of optical elements

Abstract

A method for increasing a detection distance of a surface of an object illuminated by near-IR electromagnetic radiation, including: (a) directing near-IR electromagnetic radiation from a near-IR electromagnetic radiation source towards an object at least partially coated with a near-IR reflective coating that increases a near-IR electromagnetic radiation detection distance by at least 15% as measured at a wavelength in a near-IR range as compared to the same object coated with a color matched coating which absorbs more of the same near-IR radiation, where the color matched coating has a ΔE color matched value of 1.5 or less when compared to the near-IR reflective coating; and (b) detecting reflected near-IR electromagnetic radiation reflected from the near-IR reflective coating. A system for detecting proximity of vehicles is also disclosed.

Claims

1. A method for increasing a detection distance of a surface of an object illuminated by near-IR electromagnetic radiation, comprising:

(a) directing near-IR electromagnetic radiation from a near-IR electromagnetic radiation source towards an object at least partially coated with a near-IR reflective coating that increases a near-IR electromagnetic radiation detection distance by at least 15% as measured at a wavelength in a near-IR range as compared to the same object coated with a color matched coating which absorbs more of the same near-IR radiation, wherein the color matched coating has a Δ

E color matched value of 1.5 or less when compared to the near-IR reflective coating, as measured using an integrating sphere with D65 Illumination, 10°

observer with specular component included; and

(b) detecting reflected near-IR electromagnetic radiation reflected from the near-IR reflective coating.

2. The method of claim 1, wherein the near-IR reflective coating exhibits a CIELAB L* value of 35 or less as measured using an integrating sphere with D65 Illumination, 10°

observer with specular component included.

3. The method of claim 1, wherein the near-IR reflective coating comprises at least one visibly-absorbing near-IR transparent pigment and/or dye.

4. The method of claim 1, wherein the near-IR reflective coating is substantially free of carbon black.

5. The method of claim 1, wherein the near-IR reflective coating comprises a first coating layer and a second coating layer.

6. The method of claim 5, wherein the first coating layer comprises at least one visibly-absorbing near-IR transparent pigment and/or dye and the second coating layer comprises at least one near-IR reflective pigment.

7. The method of claim 5, wherein the second coating layer underlies at least a portion of the first coating layer.

8. The method of claim 5, wherein the second coating layer comprises:

a film-forming resin;

a plurality of near-IR transparent pigments and/or dyes dispersed in the film-forming resin, the plurality of near-IR transparent pigments and/or dyes comprising a first perylene pigment and a second perylene pigment different from the first perylene pigment; and

a near-IR reflective pigment dispersed in the film-forming resin, the near-IR reflective pigment different from the first perylene pigment and the second perylene pigment,

wherein the second coating layer exhibits an off-white or grey color, and

wherein the second coating layer is substantially free of carbon black.

9. The method of claim 5, wherein the second coating layer comprises:

a film-forming resin;

a plurality of colorants dispersed in the film-forming resin, the plurality of colorants comprising a near-IR transparent pigment or dye, wherein the near-IR transparent pigment or dye comprises a first near-IR transparent pigment or dye and a second near-IR transparent pigment or dye different from the first near-IR transparent pigment or dye; and

a near-IR reflective pigment dispersed in the film-forming resin, the near-IR reflective pigment different from the first near-IR transparent pigment or dye and the second near-IR transparent pigment or dye,

wherein the second coating layer exhibits an off-white or grey color, and

wherein the second coating layer is substantially free of carbon black.

10. The method of claim 1, wherein the object is a vehicle, road, road traffic safety product, signage, or clothing.

11. The method of claim 1, wherein the near-IR reflective coating reflects at least 20% of the radiation at a wavelength in the near-IR range directed in step (a) at the object.

12. A system for detecting proximity of vehicles, comprising:

a first vehicle at least partially coated with a near-IR reflective coating that increases a near-IR electromagnetic radiation detection distance by at least 15% as measured at a wavelength in a near-IR range between the first vehicle and a second vehicle as compared to the first vehicle coated with a color matched coating which absorbs more of the near-IR radiation, wherein the color matched coating has a Δ

E color matched value of 1.5 or less when compared to the near-IR reflective coating, as measured using an integrating sphere with D65 Illumination, 10°

observer with specular component included.

13. The system of claim 12, wherein the near-IR reflective coating is substantially free of carbon black.

14. The system of claim 12, wherein the near-IR reflective coating covers at least 10 percent of an exterior surface area of the first vehicle.

15. The system of claim 12, wherein the second vehicle comprises an electromagnetic radiation source and an electromagnetic radiation detector.

16. The system of claim 12, wherein the near-IR reflective coating comprises at least one visibly-absorbing near-IR transparent pigment and/or dye.

17. The system of claim 12, wherein the near-IR reflective coating comprises at least a first coating layer and a second coating layer, wherein the first coating layer comprises at least one visibly-absorbing near-IR transparent pigment and/or dye and the second coating layer comprises the at least one near-IR reflective pigment.

18. The system of claim 12, wherein the near-IR reflective coating comprises a second coating layer positioned beneath a first coating layer comprising at least one visibly-absorbing near-IR transparent pigment and/or dye, wherein a second coating layer comprises:

a film-forming resin;

a plurality of near-IR transparent pigments and/or dyes dispersed in the film-forming resin, the plurality of near-IR transparent pigments and/or dyes comprising a first perylene pigment and a second perylene pigment different from the first perylene pigment; and

a near-IR reflective pigment dispersed in the film-forming resin, the near-IR reflective pigment different from the first perylene pigment and the second perylene pigment,

wherein the second coating layer exhibits An off-white or grey color, and

wherein the second coating layer is substantially free of carbon black.

19. The system of claim 12, wherein the near-IR reflective coating comprises a second coating layer positioned beneath a first coating layer comprising at least one visibly-absorbing near-IR transparent pigment and/or dye, wherein a second coating layer comprises:

a film-forming resin;

a plurality of colorants dispersed in the film-forming resin, the plurality of colorants comprising a near-IR transparent pigment or dye, wherein the near-IR transparent pigment or dye comprises a first near-IR transparent pigment or dye and a second near-IR transparent pigment or dye different from the first near-IR transparent pigment or dye; and

a near-IR reflective pigment dispersed in the film-forming resin, the near-IR reflective pigment different from the first near-IR transparent pigment or dye and the second near-IR transparent pigment or dye,

wherein the second coating layer exhibits an off-white or grey color, and

wherein the second coating layer is substantially free of carbon black.

20. The system of claim 12, wherein the near-IR reflective coating has a reflectance of at least 20% for electromagnetic radiation having a wavelength in a near-IR range.

21. The system of claim 12, wherein the second vehicle is an autonomously operated vehicle.

22. A system for detecting the proximity of a first vehicle to a second vehicle, comprising:

(a) a first vehicle at least partially coated with a near-IR reflective coating that increases a near-IR electromagnetic radiation detection distance by at least 15% as measured at a wavelength in a near-IR range as compared to a vehicle coated with a similar color matched coating which absorbs more of the near-IR radiation, wherein the similar color matched coating has a Δ

E color matched value of 1.5 or less when compared to the near-IR reflective coating, as measured using an integrating sphere with D65 Illumination, 10°

observer with specular component included; and

(b) a second vehicle comprising;

(i) a near-IR electromagnetic radiation source that directs near-IR electromagnetic radiation towards the first vehicle;

(ii) a near-IR detector that detects near-IR electromagnetic radiation reflected from the first vehicle; and

(iii) a computing device that determines the detection distance between the first vehicle and second vehicle based in part on the detected near-IR electromagnetic radiation reflected from the first vehicle.