Coating for increasing near-infrared detection distances

Patent metadata

Field	Value
Publication number	US-10641895-B2
Application number	US-201916253873-A
Country	US
Kind code	B2
Filing date	Jan 22, 2019
Priority date	Oct 28, 2016
Publication date	May 5, 2020
Grant date	May 5, 2020

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.

First claim

The invention claimed is:

1. A method for increasing a detection distance of a surface of an object illuminated by near-IR electromagnetic radiation, comprising:
detecting, with a near-IR detector, reflected near-IR electromagnetic radiation reflected from a near-IR reflective coating at least partially coating an object, wherein the near-IR reflective coating 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 ΔE 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.

2. The method of claim 1 , further comprising determining a distance between the object and the near-IR detector based on the detected near-IR electromagnetic radiation.

3. 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.

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

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

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

7. The method of claim 6 , 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.

8. The method of claim 6 , wherein the second coating layer underlies at least a portion of the first coating layer.

9. The method of claim 6 , 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.

10. The method of claim 6 , 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.

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

12. The method of claim 11 , wherein the object comprises a vehicle and the near-IR reflective coating covers at least a portion of an exterior surface of the vehicle.

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

14. The method of claim 1 , wherein the near-IR reflective coating reflects electromagnetic radiation having at least one wavelength in the range of 700 nm to 2500 nm.

15. The method of claim 6 , wherein the first coating layer is a top layer of the near-IR reflective coating.

16. The method of claim 6 , further comprising a clearcoat layer positioned over at least a portion of the first coating layer.

17. The method of claim 1 , wherein the near-IR detector is coupled to a vehicle.

18. The method of claim 17 , wherein the vehicle comprises an autonomously operated vehicle.

19. The method of claim 7 , wherein the second coating layer comprises at least one near-IR fluorescent pigment and/or dye.

20. The method of claim 19 , wherein the second coating layer comprises a weight ratio of the near-IR reflective pigment and/or dye to the near-IR fluorescent pigment and/or dye of at least 1.5:1.

Assignees

• Ppg Ind Ohio Inc

Inventors

• Decker Eldon L
• Kruszewski Kristen
• Holsing Luann
• Mcquown Stephen G
• Hellring Stuart D
• Zalich Michael Andrew

Classifications

• C09D5/004 Primary

  Reflecting paints; Signal paints · CPC title

• C09D17/007

  Metal oxide · CPC title

• C09D7/41

  Organic pigments; Organic dyes · CPC title

• C09D7/70

  characterised by shape, e.g. fibres, flakes or microspheres · CPC title

• G01S7/481

  Constructional features, e.g. arrangements of optical elements · CPC title