Lidar reflective black paper and non-woven articles

Abstract

A paper article, molded article, or non-woven article having a matrix made from pulp, a polymer, or a plurality of fibers and including a pigment having a reflectivity in the visible spectrum of electromagnetic radiation that is less than or equal to 10.0%, and a reflectivity in the near-IR and LiDAR spectrum of electromagnetic radiation that is greater than or equal to 12%.

Description

TECHNICAL FIELD

[0001] The present specification generally relates to light detecting and ranging (LiDAR) materials, and particularly to black-colored LiDAR reflective materials.BACKGROUND

[0002] LiDAR systems using pulsed laser electromagnetic radiation with a wavelength of 905 nanometers (nm) or 1050 nm have been proposed and obstacle detection and avoidance systems in vehicles, robotics, as well as in other automated detection systems. However, dark-colored (e.g., black) pigments used in materials to provide a dark-colored objects absorb not only visible electromagnetic radiation to provide the dark color, but also absorb near-IR electromagnetic radiation with wavelengths of greater than about 750 nanometers, which includes LiDAR electromagnetic radiation.

[0003] Accordingly, a need exists for articles that absorb electromagnetic radiation within the visible spectrum, thus appearing dark-colored, but that reflect near-IR electromagnetic radiation with wavelengths around 905 nm or 1050 nm.SUMMARY

[0004] A first aspect includes a paper article comprising: a matrix made from pulp; and a pigment having a reflectivity in the visible spectrum of electromagnetic radiation that is less than or equal to 10.0%, and a reflectivity in the near-IR and LiDAR spectrum of electromagnetic radiation that is greater than or equal to 12%.

[0005] A second aspect includes the paper article of the first aspect, wherein the pulp is dyed with the pigment.

[0006] A third aspect includes the paper article of any one of the first or second aspects, wherein the paper article has a reflectivity in the visible spectrum of electromagnetic radiation that is less than or equal to 10.0%, and a reflectivity in the near-IR and LiDAR spectrum of electromagnetic radiation that is greater than or equal to 12%.

[0007] A fourth aspect includes the paper article of any one of the first to third aspects, wherein the paper article comprises greater than or equal to 0.1 wt. % and less than or equal to 22 wt. % of the pigment.

[0008] A fifth aspect includes the paper article of any one of the first to fourth aspects, wherein the paper article has a blackness My that is greater than or equal to 125 and less than or equal to 300.

[0009] A sixth aspect includes the paper article of any one of the first to fifth aspects, wherein the pigment is applied to at least a portion of the paper article by a liquidus marking material.

[0010] A seventh aspect includes the paper article of the sixth aspect, wherein the liquidus marking material comprises greater than or equal to 0.1 wt. % and less than or equal to 22 wt. % of the pigment.

[0011] An eighth aspect includes the paper article of any one of the sixth or seventh aspects, wherein the portion of the paper article has a reflectivity in the visible spectrum of electromagnetic radiation that is less than or equal to 10.0%, and a reflectivity in the near-IR and LiDAR spectrum of electromagnetic radiation that is greater than or equal to 12%.

[0012] A ninth aspect includes the paper article of any one of the sixth to eighth aspects, wherein the portion of the paper article has a blackness My that is greater than or equal to 125 and less than or equal to 300.

[0013] A tenth aspect includes the paper article of any one of the first to ninth aspects, wherein the pigment is incorporated into the paper article as a fiber.

[0014] An eleventh aspect includes the paper article of the tenth aspect, wherein the fiber has a diameter of greater than or equal to 1 μm and less than or equal to 50 μm.

[0015] A twelfth aspect includes the paper article of any one of the tenth or eleventh aspects, wherein the fiber comprises greater than or equal to 0.1 wt. % and less than or equal to 22 wt. % of the pigment.

[0016] A thirteenth aspect includes the paper article of any one of the tenth to twelfth aspects, wherein at least a portion of the paper article comprises the fibers.

[0017] A fourteenth aspect includes the paper article of thirteenth aspect, wherein the portion of the paper article has a reflectivity in the visible spectrum of electromagnetic radiation that is less than or equal to 10.0%, and a reflectivity in the near-IR and LiDAR spectrum of electromagnetic radiation that is greater than or equal to 12%.

[0018] A fifteenth aspect includes the paper article of any one of the thirteenth or fourteenth aspects, wherein the portion of the paper article has a blackness My that is greater than or equal to 125 and less than or equal to 300.

[0019] A sixteenth aspect includes the paper article of any one of the sixth to fifteenth aspects, wherein in the portion of the paper article is a unique design.

[0020] A seventeenth aspect includes the paper article of the sixteenth aspect, wherein the unique design is a glyph, bar code, or QR code, or decorative image.

[0021] An eighteenth aspect includes the paper article of any one of the first to seventeenth aspects, wherein the pigment is copper oxide nano-crystallites.

[0022] A nineteenth aspect includes the paper article of the eighteenth aspect, wherein the copper oxide crystallites have an average particle size that is greater than or equal to 5 nm and less than or equal to 15 nm.

[0023] A twentieth aspect includes the paper article of any one of the eighteenth or nineteenth aspects, wherein the copper oxide crystallites have a ratio of (−111) / (111) greater than or equal to 0.5 and less than or equal to 1.5.

[0024] A twenty-first aspect includes a tape, sticker, wallpaper, security paper, or temporary tattoo comprising the paper article of any one of the first to twentieth aspects.

[0025] A twenty-second aspect includes a molded article comprising: a polymer; and a pigment having a reflectivity in the visible spectrum of electromagnetic radiation that is less than or equal to 10.0%, and a reflectivity in the near-IR and LiDAR spectrum of electromagnetic radiation that is greater than or equal to 12%.

[0026] A twenty-third aspect includes a molded article of the twenty-first aspect, wherein the molded article comprises greater than or equal to 0.1 wt. % and less than or equal to 22 wt. % of the pigment.

[0027] A twenty-fourth aspect includes a molded article of any one of the twenty-first to twenty-third aspects, wherein the molded article has a blackness My that is greater than or equal to 125 and less than or equal to 300.

[0028] A twenty-fifth aspect includes a molded article of any one of the twenty-first to twenty-fourth aspects, wherein the molded article has a reflectivity in the visible spectrum of electromagnetic radiation that is less than or equal to 10.0%, and a reflectivity in the near-IR and LiDAR spectrum of electromagnetic radiation that is greater than or equal to 12%.

[0029] A twenty-sixth aspect includes a molded article of any one of the twenty-first to twenty-fifth aspects, wherein the polymer is selected from the group consisting of polyamide, polyacrylonitrile, polyethylene terephthanlate (PET), polybutyrate, polyurethane, nylon, polyester, polymethyl methacrylate (PMMA), polyvinyl chloride (PVC), polypropylene, polystyrene (PS), polytetrafluoroethylene (PTFE), low-density polythene (LDPE), high-density polythene (HDPE), polyimides, polysiloxanes, polypropylene, epoxy, melamine formaldehyde, and phenol formaldehyde.

[0030] A twenty-seventh aspect includes a molded article of any one of the twenty-first to twenty-fifth aspects, wherein the polymer is a natural or synthetic elastomer.

[0031] A twenty-eighth aspect includes a molded article of the twenty-seventh aspect, wherein the elastomer is selected from the group consisting silicone rubber, nitrile rubber, styrene-butadiene, chlorpene, cis-polyisoprene, cis-polybutadiene, and ethylene-propylene.

[0032] A twenty-ninth aspect includes a molded article of any one of the twenty-first to twenty-eighth aspects, wherein the pigment is copper oxide nano-crystallites.

[0033] A thirtieth aspect includes a molded article of the twenty-ninth aspect, wherein the copper oxide crystallites have an average particle size that is greater than or equal to 5 nm and less than or equal to 15 nm.

[0034] A thirty-first aspect includes a molded article of any one of the twenty-ninth or thirtieth aspects, wherein the copper oxide crystallites have a ratio of (−111) / (111) greater than or equal to 0.5 and less than or equal to 1.5.

[0035] A thirty-second aspect includes the molded article of any one of the twenty-first to thirty-first aspects, wherein the molded article is furniture, a building material, a vehicle component, a consumer electronic component, a consumer product, a plastic bag, a film, protective equipment, a tire, a physical marker, or a sign.

[0036] A thirty-third aspect includes a non-woven article comprising: a plurality of fibers; and a pigment having a reflectivity in the visible spectrum of electromagnetic radiation that is less than or equal to 10.0%, and a reflectivity in the near-IR and LiDAR spectrum of electromagnetic radiation that is greater than or equal to 12%.

[0037] A thirty-fourth aspect includes the non-woven article of the thirty-third aspect, wherein the pigment is present in a fiber or filament.

[0038] A thirty-fifth aspect includes the non-woven article of the thirty-fourth aspect, wherein the fiber or filament comprises greater than or equal to 0.1 wt. % and less than or equal to 22 wt. % of the pigment.

[0039] A thirty-sixth aspect includes the non-woven article of any one of the thirty-third to thirty-fifth aspects, wherein the non-woven article has a blackness My that is greater than or equal to 125 and less than or equal to 300.

[0040] A thirty-seventh aspect includes the non-woven article of any one of the thirty-third to thirty-sixth aspects, wherein the non-woven article has a reflectivity in the visible spectrum of electromagnetic radiation that is less than or equal to 10.0%, and a reflectivity in the near-IR and LiDAR spectrum of electromagnetic radiation that is greater than or equal to 12%.

[0041] A thirty-eighth aspect includes the non-woven article of any one of the thirty-fourth to thirty-fifth aspects, wherein a portion of the non-woven article comprises the fiber or filament with the pigment.

[0042] A thirty-ninth aspect includes the non-woven article of the thirty-eighth aspect, wherein the portion of the non-woven article has a blackness My that is greater than or equal to 125 and less than or equal to 300.

[0043] A fortieth aspect includes the non-woven of any one of the thirty-eighth or thirty-ninth aspects, wherein portion of the non-woven article has a reflectivity in the visible spectrum of electromagnetic radiation that is less than or equal to 10.0%, and a reflectivity in the near-IR and LiDAR spectrum of electromagnetic radiation that is greater than or equal to 12%.

[0044] A forty-first aspect includes the non-woven article of any one of the thirty-eighth to fortieth aspects, wherein in the portion of the paper article is a unique design.

[0045] A forty-second aspect includes the non-woven article of the forty-first aspect, wherein the unique design is a glyph, bar code, or QR code, or decorative image.

[0046] A forty-third aspect includes the non-woven article of any one of the thirty-third to forty-second aspects, wherein the pigment is copper oxide nano-crystallites.

[0047] A forty-fourth aspect includes the non-woven article of any one of the thirty-third to forty-third aspects, wherein the copper oxide crystallites have an average particle size that is greater than or equal to 5 nm and less than or equal to 15 nm.

[0048] A forty-fifth aspect includes the non-woven article of any one of the thirty-third to forty-fourth aspects, wherein the copper oxide crystallites have a ratio of (−111) / (111) greater than or equal to 0.5 and less than or equal to 1.5.

[0049] These and additional features provided by the embodiments described herein will be more fully understood in view of the following detailed description in conjunction with the drawings.BRIEF DESCRIPTION OF THE DRAWINGS

[0050] The embodiments set forth in the drawings are illustrative and exemplary in nature and not intended to limit the subject matter defined by the claims. The following detailed description of the illustrative embodiments can be understood when read in conjunction with the following drawings, where like structure is indicated with like reference numerals and in which:

[0051] FIG. 1A graphically depicts the reflectivity versus wavelength of electromagnetic radiation for conventional colorants;

[0052] FIG. 1B graphically depicts the reflectivity versus wavelength of electromagnetic radiation for colorants according to embodiments disclosed and described herein;

[0053] FIG. 2 is a bar graph depicting the blackness of commercially available materials and black TiO2;

[0054] FIG. 3 graphically depicts the reflectivity of carbon black, commercial “cool black”, commercial N—CuO—C and N—CuO-A pigment, versus wavelength;

[0055] FIG. 4A depicts XRD profiles of N—CuO-A, N—CuO—B and commercial N—CuO—C, where planes of (−111) and (111) are major planes for analysis as they have highest peak intensity;

[0056] FIG. 4B depicts XRD spectra of obtained precipitates from different precipitate agents, in comparison to references of pure CuCO3, CuCO3·Cu(OH)2 and Cu(OH)2;

[0057] FIG. 5A depicts the evolution of weight percent and derivative of weight percent curves during the pyrolysis process via TGA, the inserts are the images of the corresponding CuO samples sintered at different temperatures, from left to right, 50° C., 200° C., 300° C. and 500° C.;

[0058] FIG. 5B depicts an evaluation map of samples using the following two indicators: crystallite size of (−111) and relative intensity ratio of (−111) / (111), and the insert shows raw particle samples, from left to right, N—CuO-A, N—CuO—B and commercial N—CuO—C, respectively;

[0059] FIG. 6A is photos of CuO particles with different Cu / Na molar ratios over black background and white background under normal camera (top) and NIR camera (bottom); and

[0060] FIG. 6B is a photo taken by a normal camera that reveals the blackness in visible range between carbon black (right) and CuO particles under different sintering temperatures 300° C., 400° C. and 500° C., in comparison to commercial N—CuO—C(left) on a black panel background;DETAILED DESCRIPTION

[0061] Articles disclosed and described herein comprise a LiDAR-reflective material that reflects near-IR electromagnetic radiation, which includes LiDAR, having wavelengths greater than or equal to 800 nm and less than or equal to 2500 nm but is also dark-colored.

[0062] As used herein, the term “near-IR electromagnetic radiation” refers to electromagnetic radiation with wavelengths greater than or equal to 800 nm and less than or equal to 2500 nm, and “LiDAR” refers to electromagnetic radiation with wavelengths greater than or equal to 905 nm and less than or equal to 1550 nm, including wavelengths of 905 nm and 1050 nm.

[0063] As used herein, the term “visible spectrum” refers to electromagnetic radiation with wavelengths greater than or equal to 350 nm and less than or equal to 750 nm, which are typical visible by the unaided human eye.

[0064] As used herein, the term “blackness” or “My” refers to an experimentally determined property of a material related to the material's ability to absorb light. The degree of blackness of the painted samples was evaluated by X-Rite Ci7600 benchtop spectrophotometer (USA, X-Rite) based on the reference provided (i.e. carbon black). It is based on the known formula, seen below, where My is measured under D65 / 10° conditions.My=100⁢ log⁢ (Yn / Y)

[0065] As used herein, the term “reflectivity” refers to a property of a material related to the material's ability to reflect electromagnetic radiation. Reflectivity is measured quantitatively from calibrated analysis of reflection data collected using a UV-visible light spectrometer.

[0066] As used herein, the term “particle size” refers to a value of at least one dimension of a particle, or when referring to a sample of more than one particle, an average value for the at least one dimension over the sample population of particles. Particle size is measured by scanning electron microscopy and transition electron microscopy.

[0067] One difficulty in forming dark-colored (such as black) materials that also reflect LiDAR or near-IR electromagnetic radiation is the close proximity of the visible spectrum of electromagnetic radiation and near-IR electromagnetic radiation or LiDAR. Materials that provide a dark color, such as black, do not reflect electromagnetic radiation within the visible spectrum of electromagnetic radiation. Such materials will generally also not reflect electromagnetic radiation just outside of the visible spectrum of electromagnetic radiation, such as near-IR and LiDAR electromagnetic radiation. Carbon black is one such material that is commonly used as a dark pigment and that does not reflect electromagnetic radiation in the visible spectrum and that also does not reflect near-IR or LiDAR electromagnetic radiation. Accordingly, a material that does not reflect electromagnetic radiation within the visible spectrum but that does reflect near-IR or LiDAR electromagnetic radiation is required to have a very sharp increase in reflectivity just outside of the visible spectrum of electromagnetic radiation.

[0068] Accordingly, it is desired to be able to make materials that are a dark-colored and LiDAR-reflective. Dark-colored LiDAR reflective materials may be useful for integrating LiDAR-reflective properties to articles where a dark-colored appearance is necessary or aesthetically desirable. For instance, black and other dark colors are popular in clothing, building materials, furniture, sculptures, and numerous other applications. It is desirable to be able to continue to use black and other dark colors in the myriad of applications they are currently used in while being able to incorporate LiDAR reflectivity so that these black or dark-colored articles can retain their aesthetic and functional attributes while being detectable by LiDAR-enabled cameras and the like.

[0069] As will described in more detail herein below, dark-colored LiDAR reflecting pigment may be disposed on or incorporated into various materials to impart both a dark-colored appearance and LiDAR reflectivity to the material in which is it deposited on or incorporated into. Non-limiting examples of materials in which the LiDAR reflective pigments may be deposited on or incorporated into include textiles materials, plastic articles, polymeric articles, paper articles, and the like. Initially, LiDAR-reflective black pigment will be described.The LiDAR-Reflective Black Pigment

[0070] With reference now to FIG. 1A, the reflectivity of materials that are commonly used as dark-colored or “black” colorants are shown. The percentage of reflectivity is presented along the y-axis of FIG. 1A and the wavelength of the electromagnetic radiation is provided along the x-axis of FIG. 1A. The reflectivity of a conventional black colorant, such as carbon black (an example of which is available from Cabot Corporation and was evaluated as “Carbon Black” herein), is shown along the bottom of the graph. As shown in FIG. 1A, the carbon black colorant does not reflect electromagnetic radiation in the visible spectrum (to the left of the graph). Namely, the reflection of this black colorant is near zero percent within the visible spectrum of electromagnetic radiation. This indicates that the colorant provides a dark, nearly pure black color. However, this conventional colorant also reflects around zero percent of electromagnetic radiation outside of the visible spectrum (to the right on the graph), such as near-IR electromagnetic radiation or LiDAR electromagnetic radiation (e.g., from greater than about 750 nanometers (nm) to about 1550 nm). Similarly, near the top of the graph is shown the reflectivity of white TiO2, which is used as a conventional white colorant. As shown in FIG. 1A, white TiO2 reflects near-IR and LiDAR electromagnetic radiation as shown on the right side of the graph (e.g., from greater than about 750 nm to 1550 nm) where the reflection of near-IR and LiDAR electromagnetic radiation is greater than forty percent (at 1550 nm), and around sixty percent (at 905 nm). However, white TiO2, as the name indicates, also reflects electromagnetic radiation within the visible spectrum. As shown in FIG. 1A, white TiO2 reflects nearly eighty percent of electromagnetic radiation within the visible spectrum. Accordingly, neither of these colorants—carbon black or white TiO2—are suitable as a dark-colored particle that also reflects near-IR or LiDAR electromagnetic radiation.

[0071] FIG. 1B is a graph showing the target conditions of a colorant that does not reflect light in the visible spectrum of electromagnetic radiation, but that does reflect near-IR and LiDAR electromagnetic radiation. In FIG. 1B, the percentage of reflectivity is measured along the y-axis and the wavelength of electromagnetic radiation is provided along the x-axis. Along the bottom of the graph is shown the reflectivity of a conventional black colorant, which is identical to the reflectivity of the conventional black colorant (such as carbon black) shown in FIG. 1A. As shown in FIG. 1B, particles that do not reflect electromagnetic within the visible spectrum and that reflect near-IR and LiDAR electromagnetic radiation have at least two distinct regions of reflection. The first region of reflection is within the visible spectrum of electromagnetic radiation, indicated on the left side of the graph in FIG. 1B. In this region of reflection, particles that do not reflect electromagnetic within the visible spectrum and that reflect near-IR and LiDAR electromagnetic radiation will behave the same as conventional black colorants (such as carbon black) by not reflecting electromagnetic radiation within the visible spectrum. As shown in FIG. 1B, particles that do not reflect electromagnetic within the visible spectrum and that reflect near-IR and LiDAR electromagnetic radiation reflect nearly zero percent of electromagnetic radiation within the visible spectrum. However, particles that do not reflect electromagnetic within the visible spectrum and that reflect near-IR and LiDAR electromagnetic radiation have a second region of reflection that is outside of the visible spectrum of electromagnetic radiation.

[0072] The second region of reflection encompasses electromagnetic radiation with wavelengths greater than or equal to 750 nm and less than or equal to 1550 nm (which includes near-IR and LiDAR electromagnetic radiation). In the second region of reflection, the particles that do not reflect electromagnetic within the visible spectrum and that reflect near-IR and LiDAR electromagnetic radiation perform similarly as white TiO2 by reflecting a high amount of electromagnetic radiation within the second region of reflection. As shown in FIG. 1B, particles that do not reflect electromagnetic within the visible spectrum and that reflect near-IR and LiDAR electromagnetic radiation reflect, for example, about sixty percent of LiDAR electromagnetic radiation having a wavelength of 905 nm and reflects greater than forty percent of LiDAR electromagnetic radiation having a wavelength of 1550 nm. By having reflectance in the second region of reflection that is similar to white TiO2, particles can reflect a sufficient amount of near-IR and LiDAR electromagnetic radiation that the particles can be detected by LiDAR systems.

[0073] FIG. 1B shows the difficulty in forming particles that do not reflect electromagnetic within the visible spectrum and that reflect near-IR and LiDAR electromagnetic radiation. Particularly, FIG. 1B shows a steep increase in reflectance just outside of the visible spectrum of electromagnetic radiation. In embodiments, this steep increase of reflectance is present at a wavelength of electromagnetic radiation that is at or about 905 nm, which is a wavelength of electromagnetic radiation commonly used in LiDAR systems. As shown in FIG. 1B, the electromagnetic reflectivity increases from about zero percent to nearly sixty percent at a wavelength of electromagnetic radiation that is about 905 nm. Forming a particle with such a precise and steep increase in reflectivity is difficult to achieve and there is very little room for error. For instance, if the material reflects too much electromagnetic radiation within the visible spectrum, the appearance of the color will not be pure black, but will have hints of, for example, red or purple. However, if the material does not reflect a sufficient amount of near-IR or LiDAR electromagnetic radiation, the material will not be suitable for detection by LiDAR systems.

[0074] Some materials do not reflect much electromagnetic radiation within the visible spectrum and reflect near-IR and LiDAR electromagnetic radiation; however, even the small amount of reflectivity in the visible spectrum that these materials have means that they cannot reproduce the visible appearance of carbon black (i.e., having a reflectivity of about zero percent for electromagnetic radiation within the visible spectrum). One such material that has gained interest is chromium iron oxide and derivatives thereof. Although chromium iron oxide materials can generally reflect near-IR and LiDAR electromagnetic radiation, colorants made from chromium iron oxide materials are generally referred to as “cool black” because colorants made from chromium iron oxide or derivatives thereof have hints of red or blue in them. FIG. 2 is a bar graph that shows the blackness of various materials on the y-axis. Blackness is measured by X-Rite Spectrophotometer. At the far left of FIG. 2 is carbon black, which is the material commonly used as a black colorant, but carbon black does not reflect near-IR or LiDAR electromagnetic radiation. As shown in FIG. 2, carbon black has a blackness of about 165. Materials 1-7 are chromium iron oxide containing materials that reflect near-IR and LiDAR electromagnetic radiation, but as can be seen in FIG. 2, these materials have a blackness that is around 142 or less. This difference in blackness is notable to human observers, as materials 1-7 have tints of red or blue. Thus, this considerable gap in blackness between carbon black and materials 1-7 show that materials 1-7 are generally not suitable to be used in applications where pure black is desired, such as, for example, in papers, non-woven articles, and the like. Consequently, there is a need for a durable pigment that has a blackness similar to carbon black, and that also reflects near-IR and LiDAR electromagnetic radiation.

[0075] One material of interest for black color applications is Copper (II) oxide or cupric oxide (CuO). CuO is a common inorganic compound that is a black-colored solid material in its natural state. However, not all copper oxides have this black color. Namely, another stable oxide of copper is cuprous oxide (Cu2O) that is a red solid in its natural state. Therefore, the oxidation state of copper is important to ensure that the material has a black color. CuO is a product of copper mining and it is a precursor to many other copper-containing products and chemical compounds. CuO has been used as a black pigment in certain applications, such as in ceramics, glazes, and the like. However, commonly used CuO does not reflect near-IR or LiDAR electromagnetic radiation. That is, CuO in its natural state behaves much like carbon black in that it does not reflect electromagnetic radiation in the visible spectrum and it also does not reflect electromagnetic radiation in the near-IR or LiDAR spectrum. Without being bound to any particular theory, CuO has a band gap of 2.0 eV that, as described in more detail below, does not readily reflect electromagnetic radiation in the near-IR or LiDAR spectrum. When manipulating CuO to have a band gap that is more amenable to reflecting electromagnetic radiation in the near-IR or LiDAR spectrum, the color of the CuO degrades to a brownish black, which is not suitable for certain applications, such as in an paper, textiles, non-wovens and the like.

[0076] FIG. 3 is a graph showing the reflectivity of carbon black, cool black, commercially available copper oxide (N—CuO—C), and copper oxide according to embodiments disclosed and described herein (N—CuO-A). In FIG. 3, the reflectivity (in arbitrary units) is on the y-axis and the wavelength of electromagnetic radiation is along the x-axis. In FIG. 3 it can be seen that carbon black does not reflect electromagnetic radiation in the visible spectrum or near-IR or LiDAR electromagnetic radiation; cool black has moderate reflectivity in the near-IR and LiDAR ranges, but reflects nearly as much electromagnetic radiation in the visible spectrum; the reflectivity of N—CuO—C increases dramatically in the near-IR and LiDAR range but starts increasing reflectivity in the visible spectrum resulting in a reddish tint; however N—CuO-A has a reflectivity that is comparable to carbon black in the visible spectrum and spikes suddenly in the near-IR rang to have significant reflectivity at the LiDAR range. Without being bound by any particular theory, one way of determining this transition of low reflectivity in the visible spectrum of electromagnetic radiation to high reflectivity at near-IR and LiDAR electromagnetic radiation is by evaluating the band gap of a material.

[0077] The band gap generally refers to the energy difference (in electron volts or eV) between the top of the valence band (VB) and the bottom of the conduction band (CB). The VB is the band of electron orbitals that electrons can jump out of, moving into the CB when excited. The VB is the outermost electron orbital of an atom that electrons can actually occupy. The band gap is the energy required for an electron to move from the VB to the CB and can be indicative of the electrical conductivity of the material. In optics, the band gap correlates to the threshold where photons can be absorbed by a material. Therefore, without begin bound by any particular theory, the band gap determines what portion of the electromagnetic spectrum the material can absorb. Generally, a material with a large band gap will absorb a greater portion of electromagnetic spectra having a short wavelength, and a material with a small band gap will absorb a greater portion of electromagnetic spectra having long wavelengths. Put differently, a large band gap means that a lot of energy is required to excite valence electrons to the CB. In contrast, when the valence band and conduction band overlap as they do in metals, electrons can readily jump between the two bands, which means that the material is highly conductive. However, it has been found that by manipulating the band gap of a material, the types of electromagnetic spectra that are absorbed by the material may be controlled. In view of this, materials with bandgap energy near the LiDAR detection electromagnetic radiation wavelength (around 905 nm) have a band gap around 1.37 eV and sharp transition at the visible edge (around 700 nm) and are promising candidates as materials that do not reflect visible electromagnetic radiation but that do reflect near-IR and LiDAR electromagnetic radiation.

[0078] Cupric (II) oxide (CuO) is a monoclinic p-type semiconductor with fundamental bandgap of indirect nature. The experimental values of its indirect bandgap have been determined to be in the range of 1.2 eV to 2.2 eV. CuO compounds have been studied widely in areas such as solar energy materials, gas sensors, magnetic media, optical devices, batteries, catalyst, as well as constructing junction devices and superconducting materials. It has also been emphasized that the bandgap of CuO is tunable by means of different approaches such as dopants, synthesis solvent and stoichiometry, nanoparticle size, and the shape of the nanostructure as well as the morphology. Currently, the bandgap engineering studies of CuO focus on an optical response to solar radiation and its catalytic behavior. However, there is no disclosure directed to tailoring CuO to absorb wavelengths in the visible spectrum of electromagnetic radiation and to reflect electromagnetic radiation wavelengths in near-IR and LiDAR spectrum. There have also been past efforts to improve the blackness of CuO by physically tailoring the particle size via ball milling or other techniques. However, it has not been possible to mill CuO to reach the blackness level of carbon black.

[0079] Generally, a band gap of from 1.2 eV to 1.8 eV is required for a compound to absorb (i.e., not reflect) electromagnetic radiation in the visible spectrum and reflect electromagnetic radiation in the near-IR and LiDAR spectrum. Without manipulation, bulk CuO does not meet these requirements. Bulk CuO has a reported band gap of 2.0 eV and a blackness My value of 128. This band gap is outside of the 1.2 eV to 1.8 eV required to reflect electromagnetic radiation in the near-IR and LiDAR spectrum. Further, as noted above with reference to FIG. 2, a blackness of 128 is significantly lower than the blackness of about 165 for carbon black. Accordingly, in embodiments disclosed and described herein, methods for forming CuO crystallites having significantly reduced particle sizes that result in a decrease the bandgap and increase in the blackness of CuO are provided.

[0080] In embodiments, a synthesis of a type of CuO crystallites (also referred to herein as “N—CuO-A”) that may be used as a replacement for carbon black and show superior blackness in the visible spectrum of electromagnetic radiation while also having high reflectivity in near-IR and LiDAR electromagnetic radiation wavelengths are provided. The N—CuO-A may, in embodiments be synthesized via scalable precipitation-pyrolysis methods—with proper selection in precipitating agents at certain concentration ranges—that is followed by a well-defined sintering process. Structural and chemical composition studies depict the evolution from precursor to extracted precipitates, and to final CuO crystallites at various process stages.

[0081] In addition to the bandgap, two key indicators in XRD spectra to guide the experimental conditions towards the desired crystal structure and resultant optical contrast in both visible and near-IR range were unexpectedly discovered. Namely, without being bound by any particular theory, it is believed that the sharp transition of reflectivity (or absorbance) between 700 nm wavelength and 905 nm wavelength electromagnetic radiation is attributed to the near unity ratio of (−111) / (111) crystal facets and at a crystal size around 100 Å for the (−111) plane. Further discussion of these attributes is provided in U.S. Patent Application Publication No. 2022 / 0017379, which is incorporated herein by reference in its entirety.

[0082] Accordingly, in embodiments, the ratio of (−111) / (111) may be greater than or equal to 0.8 and less than or equal to 1.3, such as greater than or equal to 0.9 and less than or equal to 1.3, greater than or equal to 1.0 and less than or equal to 1.3, greater than or equal to 1.1 and less than or equal to 1.3, greater than or equal to 1.2 and less than or equal to 1.3, greater than or equal to 0.8 and less than or equal to 1.2, greater than or equal to 0.9 and less than or equal to 1.2, greater than or equal to 1.0 and less than or equal to 1.2, greater than or equal to 1.1 and less than or equal to 1.2, greater than or equal to 0.8 and less than or equal to 1.1, greater than or equal to 0.9 and less than or equal to 1.1, greater than or equal to 1.0 and less than or equal to 1.1, greater than or equal to 0.8 and less than or equal to 1.0, greater than or equal to 0.9 and less than or equal to 1.0, or greater than or equal to 0.8 and less than or equal to 0.9.

[0083] By reducing the size of CuO particles, such as to the average particle sizes disclosed below, the band gap of the CuO decreases. In embodiments, the band gap as measured by X-ray photoelectron spectroscopy (XPS) of the CuO nanoparticles is greater than or equal to 1.2 eV and less than or equal to 2.0 eV, such as greater than or equal to 1.3 eV and less than or equal to 1.8 eV, greater than or equal to 1.4 eV and less than or equal to 1.8 eV, greater than or equal to 1.5 eV and less than or equal to 1.8 eV, greater than or equal to 1.6 eV and less than or equal to 1.8 eV, greater than or equal to 1.7 eV and less than or equal to 1.8 eV, is greater than or equal to 1.2 eV and less than or equal to 1.7 eV, such as greater than or equal to 1.3 eV and less than or equal to 1.7 eV, greater than or equal to 1.4 eV and less than or equal to 1.7 eV, greater than or equal to 1.5 eV and less than or equal to 1.7 eV, greater than or equal to 1.6 eV and less than or equal to 1.7 eV, greater than or equal to 1.2 eV and less than or equal to 1.6 eV, such as greater than or equal to 1.3 eV and less than or equal to 1.6 eV, greater than or equal to 1.4 eV and less than or equal to 1.6 eV, greater than or equal to 1.5 eV and less than or equal to 1.6 eV, greater than or equal to 1.2 eV and less than or equal to 1.5 eV, such as greater than or equal to 1.3 eV and less than or equal to 1.5 eV, greater than or equal to 1.4 eV and less than or equal to 1.5 eV, greater than or equal to 1.2 eV and less than or equal to 1.4 eV, such as greater than or equal to 1.3 eV and less than or equal to 1.4 eV, or greater than or equal to 1.2 eV and less than or equal to 1.3 eV.

[0084] Without being bound by any particular theory, it is believed that the smaller the average crystal size of the CuO nanoparticles, the lower the band gap of the CuO nanoparticles will be. Thus, by reducing bulk CuO particles to CuO nanoparticles according to embodiments disclosed and described herein, the band gap of the CuO nanoparticles is within the range that will reflect electromagnetic radiation within the near-IR and LiDAR spectrum, such as having a band gap that is between 1.5 eV and 2.0 eV.

[0085] In embodiments, the CuO crystallites may have an average particle size that is greater than or equal to 5 nm and less than or equal to 50 nm, such as greater than or equal to 10 nm and less than or equal to 45 nm, greater than or equal to 15 nm and less than or equal to 30 nm, greater than or equal to 20 nm and less than or equal to 25 nm, greater than or equal to 30 nm and less than or equal to 50 nm, greater than or equal to 35 nm and less than or equal to 50 nm, greater than or equal to 40 nm and less than or equal to 50 nm, or greater than or equal to 45 nm and less than or equal to 50 nm.

[0086] In embodiments, the CuO crystallites may have an average particle size that is greater than or equal to 5 nm and less than or equal to 15 nm, such as greater than or equal to 6 nm and less than or equal to 14 nm, greater than or equal to 7 nm and less than or equal to 13 nm, greater than or equal to 8 nm and less than or equal to 12 nm, greater than or equal to 9 nm and less than or equal to 11 nm, greater than or equal to 7 nm and less than or equal to 10 nm, greater than or equal to 8 nm and less than or equal to 10 nm, or greater than or equal to 10 nm and less than or equal to 12 nm.

[0087] The blackness My (i.e., a measure of blackness) of the CuO crystallites is, in embodiments, greater than or equal to 130 and less than or equal to 170, such as greater than or equal to 135 and less than or equal to 165, greater than or equal to 140 and less than or equal to 160, greater than or equal to 145 and less than or equal to 155, greater than or equal to 150 and less than or equal to 170, greater than or equal to 150 and less than or equal to 165, greater than or equal to 160 and less than or equal to 170, greater than or equal to 165 and less than or equal to 170, or greater than or equal to 155 and less than or equal to 165.

[0088] Copper oxide crystallites according to embodiments disclosed and described herein have a reflectivity in the visible spectrum of electromagnetic radiation that is less than or equal to 10.0%, such as less than or equal to 9.0%, less than or equal to 8.0%, less than or equal to 7.0%, less than or equal to 6.0%, less than or equal to 5.0%, less than or equal to 4.0%, less than or equal to 3.0%, less than or equal to 2.0%, less than or equal to 1.0%, or less than or equal to 0.5%.

[0089] Copper oxide crystallites according to embodiments disclosed and described herein have a reflectivity in the near-IR and LiDAR spectrum of electromagnetic radiation that is greater than or equal to 10%, such as greater than or equal to 15%, greater than or equal to 20%, greater than or equal to 25%, greater than or equal to 30%, greater than or equal to 35%, greater than or equal to 40%, greater than or equal to 45%, greater than or equal to 50%, greater than or equal to 55%, or greater than or equal to 60%. In one or more embodiments, the copper oxide crystallites have a reflectivity in the near-IR and LiDAR spectrum of electromagnetic radiation that is greater than or equal to 10% and less than or equal to 60%, such as greater than or equal to 15% and less than or equal to 60%, greater than or equal to 20% and less than or equal to 60%, greater than or equal to 25% and less than or equal to 60%, greater than or equal to 30% and less than or equal to 60%, greater than or equal to 35% and less than or equal to 60%, greater than or equal to 40% and less than or equal to 60%, greater than or equal to 45% and less than or equal to 60%, greater than or equal to 50% and less than or equal to 60%, or greater than or equal to 55% and less than or equal to 60%.

[0090] Methods for making CuO crystallites according to embodiments will now be described.

[0091] The evolution of the crystal structure and size were studied from the precursors to extracted precipitates, and to the final products N—CuO-A obtained after sintering. First, for comparison, different precipitating agents of NaOH and Na2CO3 having a constant Cu / Na molar ratio of 0.65 were used. Without being bound by any particular theory, the reactions involved, when Na2CO3 was used, are in reactions from (1) to (4) below, where Reaction (2) and (4) lead to the formation of CuO. The precipitate formed using Na2CO3 shows lime green color in the air and exhibits similar XRD peaks as reference CuCO3·Cu(OH)2 with main peaks at 32° and is believed to follows Reaction (1); no peaks of CuCO3 can be identified. Sintering at higher temperature is required for the malachite to become CuO according to Reaction (2).

[0092] On the other hand, the extracted precipitate obtained by using NaOH shows brownish black color, which exhibits similar XRD profiles as final product N—CuO—B in FIG. 4A. These characterizations confirm that the precipitation using NaOH follows Reactions (5) and (6) in an aqueous phase rather than Reaction (7) in solid phase. Copper hydroxide Cu(OH)2 is known to be metastable and it is easily transforms into a more stable form copper (II) oxide. The kinetics of transformation to copper (II) oxide can be performed slowly in pure water at room temperature, but with presence of hydroxide ions OH, it turns fast because the divalent copper ions are easily dissolved during the form of tetrahydroxocuprate (II) anions Cu(OH)42−, followed by the precipitation of CuO in Reaction (6). Here, the formation of CuO with (−111) plane as the growth plane was identified by XRD, which leads to high near-IR and LiDAR reflectivity but visually brownish, as shown in FIG. 4B. The subsequent sintering process at 300° C. would not reverse the ratio between (−111) and (111) planes or change the growth direction, but rather increases the size of crystalline planes, as shown in FIG. 4B.

[0093] When using a Na2CO3 precipitating agent in the synthesis step, the extracted precipitate is identified as CuCO3· Cu(OH)2. Thermogravimetry analysis (TGA) is used to assess the pyrolysis process of converting CuCO3. Cu(OH)2 to N—CuO-A. The mass loss of water and carbon dioxide separately generated from Reaction (2) above can be determined by TGA, as well as the critical temperature when the conversion starts. Here, the obtained CuCO3·Cu(OH)2 was sintered from ambient temperature to 600° C. in the air via TGA. A major weight-loss of malachite during the pyrolysis process was observed between 200° C. to 300° C., due to the release of H2O and CO2. Visual observation indicates the malachite turns from original lime green color to orange color at about 200° C., then to jet-black color at 300° C., and to slightly brownish at higher temperatures. It is known that synthetic malachite decomposes thermally in a single step which was also confirmed by the single-peak DTA curve shown in FIG. 5A. CuO became stable at around 300° C. and above, as evident from TGA analysis shown in FIG. 5A and FIG. 5B.

[0094] These measurements show that the decomposition of CuCO3·Cu(OH)2 into CuO mainly happens between 250° C. to 300° C., which is where significant weight change happens. The weight-loss value of 28.1% in total at 300° C. indicates the molar ratio of CuCO3 to Cu(OH)2 is near unity, which further confirms the formation of pure malachite rather than CuCO3 or Cu(OH)2. Further increases in the annealing temperature above 300° C. would lead to negligible weight-loss but growth of CuO crystallites. FIG. 5B. On the other hand, shows that the relative intensity of (111) / (−111) is reduced significantly before 300° C. during conversion from malachite to CuO then becomes stable afterwards. At 300° C., CuO particles synthesized from Na2CO3 (such as N—CuO-A) at the Cu / Na molar ratio of 0.65 have the highest blackness comparing with counterparts at higher sintering temperatures or commercial N—CuO—C as shown in FIG. 6A.

[0095] Table 1 below summarizes the XRD profiles of the resultant CuO samples with varying Cu / Na molar ratio, in terms of the crystallite size of (−111) plane and the intensity ratio of (−111) / (111). The crystallite size of CuO decreases with decreasing Cu / Na molar ratio until about 0.53 and further decrease in the Cu / Na molar ratio leads to minimal change in the crystallite size. On the other hand, there is no noticeable change in the (−111) / (111) ratio with changing Cu / Na molar ratio during the synthesis. All the samples exhibit the ratio of (−111) / (111) around 1.00±0.05.TABLE 1Crystallite size, ratio of (−111) / (111) planes forCuO materials synthesized by varying Cu / Na molar ratios.Cu / NaCrystallite size(−111) / (111)ratio(Å) (−111)ratio1.521990.991.121961.010.91430.970.761281.030.651041.030.53811.040.48811.050.36791.05

[0096] FIG. 6A shows photographic image of the CuO nanoparticles with varying Cu / Na molar ratios over black and white backgrounds in the same order. As shown on the black background, the visual blackness of powders increases with decreasing Cu / Na molar ratio until about 0.7, and then ineligible change in the blackness is observed with further decrease in the Cu / Na molar ratio. However, the photo taken using near-IR camera indicates near-IR and LiDAR reflectivity greatly reduces if Cu / Na molar ratio reduces to less than 0.65, which implies the adverse effect of the Na+ impurity onto the crystal structures and the near-IR and LiDAR reflectivity.

[0097] Accordingly, in embodiments, the Cu / Na molar ratio used in precipitates to formulate CuO crystallites, is greater than or equal to 0.3 and less than 1.6, such as greater than or equal to 0.4 and less than 1.5, greater than or equal to 0.5 and less than 1.4, greater than or equal to 0.6 and less than 1.3, greater than or equal to 0.7 and less than 1.2, greater than or equal to 0.8 and less than 1.1, greater than or equal to 0.9 and less than 1.0, greater than or equal to 0.5 and less than 0.9, greater than or equal to 0.6 and less than 0.8, greater than or equal to 0.6 and less than 0.7, greater than or equal to 0.5 and less than 0.7, or greater than or equal to 0.5 and less than 0.6.

[0098] In embodiments, and as discussed in more detail below, ammonium carbonate ((NH4)2CO3) is used to form the CuO crystallites in place of sodium-containing composition (such as NaOH and NaCO3). In such embodiments, the CO3 / Cu molar ratio is greater than or equal to 0.3 and less than 1.6, such as greater than or equal to 0.4 and less than 1.5, greater than or equal to 0.5 and less than 1.4, greater than or equal to 0.6 and less than 1.3, greater than or equal to 0.7 and less than 1.2, greater than or equal to 0.8 and less than 1.1, greater than or equal to 0.9 and less than 1.0, greater than or equal to 0.8 and less than 1.2, greater than or equal to 0.9 and less than 1.2, greater than or equal to 1.0 and less than 1.2, greater than or equal to 0.8 and less than 1.0, or greater than or equal to 0.8 and less than 0.9.

[0099] The dried Cu(OH)2 or CuCO3 obtained from the wet chemistry methods is, according to embodiments, sintered at a temperature greater than or equal to 200° C. and less than or equal to 400° C. for a duration greater than or equal to 0.5 hours and less than or equal to 5.0 hours.

[0100] In one or more embodiments, the dried Cu(OH)2 or CuCO3 is sintered at a temperature greater than or equal to 300° C. and less than or equal to 350° C., such as greater than or equal to 310° C. and less than or equal to 350° C., greater than or equal to 320° C. and less than or equal to 350° C., greater than or equal to 330° C. and less than or equal to 350° C., greater than or equal to 340° C. and less than or equal to 350° C., greater than or equal to 300° C. and less than or equal to 340° C., greater than or equal to 310° C. and less than or equal to 340° C., greater than or equal to 320° C. and less than or equal to 340° C., greater than or equal to 330° C. and less than or equal to 340° C., greater than or equal to 300° C. and less than or equal to 330° C., greater than or equal to 310° C. and less than or equal to 330° C., greater than or equal to 320° C. and less than or equal to 330° C., greater than or equal to 300° C. and less than or equal to 320° C., greater than or equal to 310° C. and less than or equal to 320° C., or greater than or equal to 300° C. and less than or equal to 310° C.

[0101] According to embodiments, the dried Cu(OH)2 or CuCO3 is sintered for a duration of greater than or equal to 1.0 hours and less than or equal to 5.0 hours, such as greater than or equal to 1.5 hours and less than or equal to 4.5 hours, greater than or equal to 2.0 hours and less than or equal to 4.0 hours, greater than or equal to 2.5 hours and less than or equal to 3.5 hours, greater than or equal to 3.0 hours and less than or equal to 5.0 hours, greater than or equal to 3.5 hours and less than or equal to 5.0 hours, greater than or equal to 4.0 hours and less than or equal to 5.0 hours, or greater than or equal to 4.5 hours and less than or equal to 5.0 hours.

[0102] In some embodiments, the dark-colored LiDAR reflective pigment may include the dark pigment disclosed in U.S. Pat. No. 11,118,062, the entire content of which is incorporated by reference herein. Briefly, the dark pigment includes a core layer formed from a reflecting material; a first layer extending across the core layer; a second layer extending across the first layer; and a third layer extending across the second layer. The first layer may be formed from a first absorber material or a first dielectric material and have a thickness from about 5 nm to about 500 nm. The second layer may be formed from a second absorber material different from the first absorber material and have a thickness from about 5 nm to about 50 nm. The third layer may be formed from a third absorber material or a second dielectric material, the third absorber material being different from the second absorber material, and the third layer has a thickness from about 5 nm to about 500 nm. The pigment reflects less than 10% of incident visible electromagnetic radiation for all incident angles of the visible electromagnetic radiation between and including 0° and 45°. The pigment reflects more than 60% of incident near-IR electromagnetic radiation with wavelengths between and including 850 nm and 950 nm for all incident angles of the near-IR electromagnetic radiation between and including 0° and 45°.

[0103] In embodiments, the dark-colored LiDAR reflective pigment may be the black TiO2 disclosed in U.S. Patent Application Publication No. 2021 / 0139713, the entire content of which is incorporated herein by reference. Black TiO2 has a blackness that is comparable to the blackness of carbon black. Further, black TiO2 generally does not show tints of red and brown, and is a good substitute for carbon black. However, standard black TiO2 does not reflect near-IR or LiDAR electromagnetic radiation. Moreover, black TiO2 is more expensive to prepare than carbon black because TiO2 naturally has a white color and must be treated, such as, for example, through hydrogenation, to form black TiO2. White TiO2 reflects near-IR and LiDAR electromagnetic radiation, but when it is treated to become black TiO2 it loses its ability to reflect near-IR and LiDAR electromagnetic radiation. Accordingly, although black TiO2 is visibly similar to carbon black in terms of its blackness, carbon black is generally preferred over black TiO2 for these reasons and for economic reasons. However, white TiO2 may be converted to black TiO2 that does not reflect electromagnetic radiation within the visible spectrum and reflects near-IR and LiDAR electromagnetic radiation. In embodiments, the black TiO2 has a crystalline titanium dioxide core and an amorphous titanium dioxide shell that encompasses the crystalline titanium dioxide core.

[0104] In embodiments, the dark-colored LiDAR-reflective pigment may be a copper oxide coated cobalt oxide or copper oxide coated carbon black as disclosed in U.S. Patent Application Publication No. 2022 / 0195201, which is incorporated herein by reference in its entirety. Briefly, this dark-colored LiDAR reflective pigment includes a copper oxide coated pigment having a particle with an outer surface, and a layer of copper oxide on the outer surface. The pigment has a reflectivity of electromagnetic radiation in a visible spectrum less than or equal to 5%, and a reflectivity of electromagnetic radiation in a near-IR and LiDAR spectrum greater than or equal to 5%. The particle is cobalt oxide or carbon black.

[0105] Dark-colored pigments that also reflect near-IR and LiDAR electromagnetic radiation, such as those disclosed and described hereinabove, may be deposited on, or incorporated into a number of different materials to make materials and / or articles that are both dark-colored and that reflect near-IR and LiDAR electromagnetic radiation. These materials will be discussed more hereinbelow.Paper Articles

[0106] Dark-colored LiDAR reflective pigments according to embodiments disclosed and described herein may be deposited on or incorporated into paper articles to render the paper articles dark-colored and able to reflect near-IR and LiDAR electromagnetic radiation. The dark-colored LiDAR reflective pigments may be deposited on or incorporated into the paper articles by any suitable method. Exemplary methods for depositing or incorporating the dark-colored near-IR and LiDAR reflective pigments to paper articles will be discussed below.

[0107] Generally, paper is formed by a two-step process. In the first step, fibers, such as cellulose fibers, are extracted and converted into pulp. In the second step, the pulp is combined with a solvent—usually water—and the mixture is dried to form paper sheets. The pulp used to make paper is generally formed from forestry products, but can be made from numerous other fibers, such as cotton, sugar cane, recycled fibers. The LiDAR-reflective black pigment may be added to the solvent to color the pulp, or it may be deposited onto the paper sheet in a coating, ink, toner, or the like.

[0108] In embodiments, the LiDAR-reflective black pigments may be formed into a coating or liquidus marking material by mixing the LiDAR-reflective black pigments into a solvent to form a coating, an ink, a dye, or another liquidus marking material. The solvent may be a thinning liquid, such as any suitable oils, water, or other organic or inorganic solvent suitable for use in the papermaking process. It should be understood that additives such as binders and surfactants may be added to the thinning liquid depending on need and the intended end use of the liquidus marking material. The additives may be added to the thinning agent in any suitable amount to provide the desired effect, so long as the concentration of LiDAR-reflective black pigment in the liquidus marking material (including additives) is sufficient to provide the desired dark color and LiDAR reflectivity to the paper article.

[0109] In embodiments, the liquidus marking material may be added as a portion of the solvent in which the pulp is dissolved, thereby dying the pulp a dark color with the LiDAR-reflective black pigment. In other embodiments, the liquidus marking material may be sprayed or otherwise applied to the pulp before it is added to the solvent so that the pulp itself is coated with the LiDAR-reflective black pigment. Accordingly, when the dyed or coated pulp is formed into a dried sheet, the entirety of the dried sheet has dark color, such as black, and reflects near-IR and LiDAR electromagnetic radiation. To achieve this effect, and according to embodiments, the dyed paper sheet comprises greater than or equal to 0.1 wt. % and less than or equal to 22 wt. % of LiDAR-reflective black pigment, such as greater than or equal to 0.1 wt. % and less than or equal to 5 wt. % of LiDAR-reflective black pigment, greater than or equal to 0.5 wt. % and less than or equal to 5.5 wt. % of LiDAR-reflective black pigment, greater than or equal to 1.5 wt. % and less than or equal to 6 wt. % of LiDAR-reflective black pigment, greater than or equal to 2.0 wt. % and less than or equal to 6.5 wt. % of LiDAR-reflective black pigment, greater than or equal to 3 wt. % and less than or equal to 7 wt. % of LiDAR-reflective black pigment, greater than or equal to 4 wt. % and less than or equal to 7.5 wt. % of LiDAR-reflective black pigment, greater than or equal to 1.5 wt. % and less than or equal to 4.5 wt. % of LiDAR-reflective black pigment, greater than or equal to 2.0 wt. % and less than or equal to 5 wt. % of LiDAR-reflective black pigment, greater than or equal to 3.0 wt. % and less than or equal to 5.5 wt. % of LiDAR-reflective black pigment, greater than or equal to 2 wt. % and less than or equal to 4 wt. % of LiDAR-reflective black pigment, greater than or equal to 2.5 wt. % and less than or equal to 4.5 wt. % of LiDAR-reflective black pigment, greater than or equal to 1 wt. % and less than or equal to 18 wt. % of LiDAR-reflective black pigment, greater than or equal to 1 wt. % and less than or equal to 12 wt. % of LiDAR-reflective black pigment, greater than or equal to 1 wt. % and less than or equal to 5 wt. % of LiDAR-reflective black pigment, greater than or equal to 5 wt. % and less than or equal to 20 wt. % of LiDAR-reflective black pigment, greater than or equal to 5 wt. % and less than or equal to 12 wt. % of LiDAR-reflective black pigment, greater than or equal to 10 wt. % and less than or equal to 22 wt. % of LiDAR-reflective black pigment, greater than or equal to 10 wt. % and less than or equal to 18 wt. % of LiDAR-reflective black pigment, greater than or equal to 15 wt. % and less than or equal to 22 wt. % of LiDAR-reflective black pigment, or greater than or equal to 18 wt. % and less than or equal to 22 wt. % of LiDAR-reflective black pigment.

[0110] Paper articles dyed with the LiDAR-reflective black pigment according to embodiments disclosed and described herein have a blackness My that is greater than or equal to 125 and less than or equal to 300. In some embodiments, the paper articles dyed with the LiDAR-reflective black pigment according to embodiments disclosed and described herein may have a blackness My that is greater than or equal to 125 and less than or equal to 165, such as greater than or equal to 130 and less than or equal to 160, greater than or equal to 135 and less than or equal to 155, greater than or equal to 140 and less than or equal to 150, greater than or equal to 145 and less than or equal to 165, greater than or equal to 145 and less than or equal to 160, greater than or equal to 155 and less than or equal to 165, greater than or equal to 160 and less than or equal to 165, or greater than or equal to 150 and less than or equal to 160. In some embodiments, the paper articles dyed with the LiDAR-reflective black pigment according to embodiments disclosed and described herein may have a blackness My that is greater than or equal to 155 and less than or equal to 240, such as greater than or equal to 160 and less than or equal to 230, greater than or equal to 170 and less than or equal to 210, greater than or equal to 180 and less than or equal to 200, greater than or equal to 190 and less than or equal to 240, greater than or equal to 195 and less than or equal to 230, greater than or equal to 210 and less than or equal to 240, greater than or equal to 170 and less than or equal to 205, or greater than or equal to 200 and less than or equal to 215. In other embodiments, the paper articles dyed with the LiDAR-reflective black pigment according to embodiments disclosed and described herein may have a blackness My that is greater than or equal to 230 and less than or equal to 300, such as greater than or equal to 230 and less than or equal to 275, greater than or equal to 230 and less than or equal to 250, greater than or equal to 240 and less than or equal to 280, greater than or equal to 240 and less than or equal to 260, greater than or equal to 250 and less than or equal to 300, greater than or equal to 250 and less than or equal to 280, greater than or equal to 260 and less than or equal to 295, greater than or equal to 260 and less than or equal to 280, greater than or equal to 270 and less than or equal to 300, greater than or equal to 270 and less than or equal to 285, or greater than or equal to 280 and less than or equal to 300.

[0111] In embodiments, paper articles dyed with the LiDAR-reflective black pigment according to embodiments disclosed and described herein have a reflectivity in the visible spectrum of electromagnetic radiation that is less than or equal to 10.0%, such as less than or equal to 9.5%, less than or equal to 9.0%, less than or equal to 8.5%, less than or equal to 8.0%, less than or equal to 7.5%, less than or equal to 7.0%, less than or equal to 6.5%, less than or equal to 6.0%, less than or equal to 5.5%, less than or equal to 5.0%, less than or equal to 4.5%, less than or equal to 4.0%, less than or equal to 3.5%, less than or equal to 3.0%, less than or equal to 2.5%, less than or equal to 2.0%, less than or equal to 1.5%, or less than or equal to 1.0%.

[0112] Paper articles dyed with the LiDAR-reflective black pigment according to embodiments disclosed and described herein have a reflectivity in the near-IR and / or LiDAR spectrum of electromagnetic radiation that is greater than or equal to 12%, such as greater than or equal to 15%, greater than or equal to 20%, greater than or equal to 25%, greater than or equal to 30%, or greater than or equal to 35%. In one or more embodiments, the paper articles dyed with the LiDAR-reflective black pigment may have a reflectivity in the near-IR and LiDAR spectrum of electromagnetic radiation (from 800 nm to 2500 nm) that is greater than or equal to 12% and less than or equal to 30%, such as greater than or equal to 15% and less than or equal to 30%, greater than or equal to 20% and less than or equal to 30%, or greater than or equal to 25% and less than or equal to 30%, greater than or equal to 12% and less than or equal to 25%, greater than or equal to 15% and less than or equal to 25%, greater than or equal to 20% and less than or equal to 25%, greater than or equal to 12% and less than or equal to 20%, greater than or equal to 15% and less than or equal to 20%, or greater than or equal to 12% and less than or equal to 15%.

[0113] In other embodiments, the liquidus marking material may be printed, painted, coated, or sprayed on paper articles as or after the paper article is formed into a sheet. In this way, at least a portion of the paper sheet is coated with the LiDAR-reflective pigment and is dark colored and reflects near-IR and / or LiDAR electromagnetic radiation. It should be understood that in embodiments, the entire paper sheet may be coated with the LiDAR-reflective black pigment, but in other embodiments only a portion of the paper sheet is coated with the LiDAR-reflective pigment. In embodiments where only a portion of the paper sheet is coated with the LiDAR-reflective black pigment, the portion that is coated with the LiDAR-reflective black pigment may be a pattern or design, such as a glyph, bar code, or QR code, or decorative image.

[0114] According to embodiments, the liquidus marking material applied to at least a portion of the paper sheet comprises from greater than or equal to 0.1 wt. % and less than or equal to 22 wt. % of LiDAR-reflective black pigment, such as greater than or equal to 0.1 wt. % and less than or equal to 5 wt. % of LiDAR-reflective black pigment, greater than or equal to 0.5 wt. % and less than or equal to 5.5 wt. % of LiDAR-reflective black pigment, greater than or equal to 1.5 wt. % and less than or equal to 6 wt. % of LiDAR-reflective black pigment, greater than or equal to 2.0 wt. % and less than or equal to 6.5 wt. % of LiDAR-reflective black pigment, greater than or equal to 3 wt. % and less than or equal to 7 wt. % of LiDAR-reflective black pigment, greater than or equal to 4 wt. % and less than or equal to 7.5 wt. % of LiDAR-reflective black pigment, greater than or equal to 1.5 wt. % and less than or equal to 4.5 wt. % of LiDAR-reflective black pigment, greater than or equal to 2.0 wt. % and less than or equal to 5 wt. % of LiDAR-reflective black pigment, greater than or equal to 3.0 wt. % and less than or equal to 5.5 wt. % of LiDAR-reflective black pigment, greater than or equal to 2 wt. % and less than or equal to 4 wt. % of LiDAR-reflective black pigment, greater than or equal to 2.5 wt. % and less than or equal to 4.5 wt. % of LiDAR-reflective black pigment, greater than or equal to 1 wt. % and less than or equal to 18 wt. % of LiDAR-reflective black pigment, greater than or equal to 1 wt. % and less than or equal to 12 wt. % of LiDAR-reflective black pigment, greater than or equal to 1 wt. % and less than or equal to 5 wt. % of LiDAR-reflective black pigment, greater than or equal to 5 wt. % and less than or equal to 20 wt. % of LiDAR-reflective black pigment, greater than or equal to 5 wt. % and less than or equal to 12 wt. % of LiDAR-reflective black pigment, greater than or equal to 10 wt. % and less than or equal to 22 wt. % of LiDAR-reflective black pigment, greater than or equal to 10 wt. % and less than or equal to 18 wt. % of LiDAR-reflective black pigment, greater than or equal to 15 wt. % and less than or equal to 22 wt. % of LiDAR-reflective black pigment, or greater than or equal to 18 wt. % and less than or equal to 22 wt. % of LiDAR-reflective black pigment.

[0115] The portion of paper articles dyed with the LiDAR-reflective black pigment according to embodiments disclosed and described herein have a blackness My that is greater than or equal to 125 and less than or equal to 300. In some embodiments, the portion of paper articles dyed with the LiDAR-reflective black pigment according to embodiments disclosed and described herein may have a blackness My that is greater than or equal to 125 and less than or equal to 165, such as greater than or equal to 130 and less than or equal to 160, greater than or equal to 135 and less than or equal to 155, greater than or equal to 140 and less than or equal to 150, greater than or equal to 145 and less than or equal to 165, greater than or equal to 145 and less than or equal to 160, greater than or equal to 155 and less than or equal to 165, greater than or equal to 160 and less than or equal to 165, or greater than or equal to 150 and less than or equal to 160. In some embodiments, the portion of paper articles dyed with the LiDAR-reflective black pigment according to embodiments disclosed and described herein may have a blackness My that is greater than or equal to 155 and less than or equal to 240, such as greater than or equal to 160 and less than or equal to 230, greater than or equal to 170 and less than or equal to 210, greater than or equal to 180 and less than or equal to 200, greater than or equal to 190 and less than or equal to 240, greater than or equal to 195 and less than or equal to 230, greater than or equal to 210 and less than or equal to 240, greater than or equal to 170 and less than or equal to 205, or greater than or equal to 200 and less than or equal to 215. In other embodiments, the portion of paper articles dyed with the LiDAR-reflective black pigment according to embodiments disclosed and described herein may have a blackness My that is greater than or equal to 230 and less than or equal to 300, such as greater than or equal to 230 and less than or equal to 275, greater than or equal to 230 and less than or equal to 250, greater than or equal to 240 and less than or equal to 280, greater than or equal to 240 and less than or equal to 260, greater than or equal to 250 and less than or equal to 300, greater than or equal to 250 and less than or equal to 280, greater than or equal to 260 and less than or equal to 295, greater than or equal to 260 and less than or equal to 280, greater than or equal to 270 and less than or equal to 300, greater than or equal to 270 and less than or equal to 285, or greater than or equal to 280 and less than or equal to 300.

[0116] In embodiments, the portion of the paper articles with the LiDAR-reflective black pigment have a reflectivity in the visible spectrum of electromagnetic radiation that is less than or equal to 10.0%, such as less than or equal to 9.5%, less than or equal to 9.0%, less than or equal to 8.5%, less than or equal to 8.0%, less than or equal to 7.5%, less than or equal to 7.0%, less than or equal to 6.5%, less than or equal to 6.0%, less than or equal to 5.5%, less than or equal to 5.0%, less than or equal to 4.5%, less than or equal to 4.0%, less than or equal to 3.5%, less than or equal to 3.0%, less than or equal to 2.5%, less than or equal to 2.0%, less than or equal to 1.5%, or less than or equal to 1.0%.

[0117] Portions of the paper articles where the LiDAR-reflective black pigment according to embodiments disclosed and described herein has been applied have a reflectivity in the near-IR and / or LiDAR spectrum of electromagnetic radiation that is greater than or equal to 12%, such as greater than or equal to 15%, greater than or equal to 20%, greater than or equal to 25%, greater than or equal to 30%, or greater than or equal to 35%. In one or more embodiments, the portions of the paper articles where the LiDAR-reflective black pigment according to embodiments disclosed and described herein has been applied may have a reflectivity in the near-IR and LiDAR spectrum of electromagnetic radiation (from 800 nm to 2500 nm) that is greater than or equal to 12% and less than or equal to 30%, such as greater than or equal to 15% and less than or equal to 30%, greater than or equal to 20% and less than or equal to 30%, or greater than or equal to 25% and less than or equal to 30%, greater than or equal to 12% and less than or equal to 25%, greater than or equal to 15% and less than or equal to 25%, greater than or equal to 20% and less than or equal to 25%, greater than or equal to 12% and less than or equal to 20%, greater than or equal to 15% and less than or equal to 20%, or greater than or equal to 12% and less than or equal to 15%.

[0118] In one or more embodiments, making paper articles may also include forming polymeric fibers doped with LiDAR-reflective black pigments according to embodiments disclosed and described herein and blending the doped fibers with natural pulp fibers to form a paper article. For example, the doped polymeric fibers may be added to the solvent in which the pulp is dissolved during the papermaking process. In embodiments, the doped polymeric fibers may be homogenously dispersed with the natural pulp fibers. In one or more embodiments, the doped polymeric fibers may be included in only a portion of the paper article, such that only the portion of the paper that has the doped fibers present reflects near-IR and / or LiDAR electromagnetic radiation. In such embodiments, the portion of the paper article including the doped fibers may be in the form of an image, pattern, or design, such as a glyph, bar code, or QR code, or decorative image.

[0119] The phrase “fiber” as used herein refers to a short, ultrafine strand having a diameter of greater than or equal to 1 μm and less than or equal to 50 μm, such as greater than or equal to 15 μm and less than or equal to 45 μm, greater than or equal to 20 μm and less than or equal to 40 μm, or greater than or equal to 25 μm and less than or equal to 35 μm. The fibers may be formed by melt blowing, cutting, milling, and the like. The doping ratio of the doped fibers (e.g., the amount of LiDAR-reflective black pigment in the fiber) is greater than or equal to 0.1 wt. % and less than or equal to 22 wt. %, such as greater than or equal to 0.1 wt. % and less than or equal to 5 wt. %, greater than or equal to 0.5 wt. % and less than or equal to 5.5 wt. %, greater than or equal to 1.5 wt. % and less than or equal to 6 wt. %, greater than or equal to 2.0 wt. % and less than or equal to 6.5 wt. %, greater than or equal to 3 wt. % and less than or equal to 7 wt. %, greater than or equal to 4 wt. % and less than or equal to 7.5 wt. %, greater than or equal to 1.5 wt. % and less than or equal to 4.5 wt. %, greater than or equal to 2.0 wt. % and less than or equal to 5 wt. %, greater than or equal to 3.0 wt. % and less than or equal to 5.5 wt. %, greater than or equal to 2 wt. % and less than or equal to 4 wt. %, greater than or equal to 2.5 wt. % and less than or equal to 4.5 wt. %, greater than or equal to 1 wt. % and less than or equal to 18 wt. %, greater than or equal to 1 wt. % and less than or equal to 12 wt. %, greater than or equal to 1 wt. % and less than or equal to 5 wt. %, greater than or equal to 5 wt. % and less than or equal to 20 wt. %, greater than or equal to 5 wt. % and less than or equal to 12 wt. %, greater than or equal to 10 wt. % and less than or equal to 22 wt. %, greater than or equal to 10 wt. % and less than or equal to 18 wt. %, greater than or equal to 15 wt. % and less than or equal to 22 wt. %, or greater than or equal to 18 wt. % and less than or equal to 22 wt. %.

[0120] The portion of paper articles comprising fibers doped with LiDAR-reflective black pigment according to embodiments disclosed and described herein have a blackness My that is greater than or equal to 125 and less than or equal to 300. In some embodiments, the portion of paper articles comprising fibers doped with LiDAR-reflective black pigment according to embodiments disclosed and described herein may have a blackness My that is greater than or equal to 125 and less than or equal to 165, such as greater than or equal to 130 and less than or equal to 160, greater than or equal to 135 and less than or equal to 155, greater than or equal to 140 and less than or equal to 150, greater than or equal to 145 and less than or equal to 165, greater than or equal to 145 and less than or equal to 160, greater than or equal to 155 and less than or equal to 165, greater than or equal to 160 and less than or equal to 165, or greater than or equal to 150 and less than or equal to 160. In some embodiments, the portion of paper articles comprising fibers doped with LiDAR-reflective black pigment according to embodiments disclosed and described herein may have a blackness My that is greater than or equal to 155 and less than or equal to 240, such as greater than or equal to 160 and less than or equal to 230, greater than or equal to 170 and less than or equal to 210, greater than or equal to 180 and less than or equal to 200, greater than or equal to 190 and less than or equal to 240, greater than or equal to 195 and less than or equal to 230, greater than or equal to 210 and less than or equal to 240, greater than or equal to 170 and less than or equal to 205, or greater than or equal to 200 and less than or equal to 215. In other embodiments, the portion of paper articles comprising fibers doped with LiDAR-reflective black pigment according to embodiments disclosed and described herein may have a blackness My that is greater than or equal to 230 and less than or equal to 300, such as greater than or equal to 230 and less than or equal to 275, greater than or equal to 230 and less than or equal to 250, greater than or equal to 240 and less than or equal to 280, greater than or equal to 240 and less than or equal to 260, greater than or equal to 250 and less than or equal to 300, greater than or equal to 250 and less than or equal to 280, greater than or equal to 260 and less than or equal to 295, greater than or equal to 260 and less than or equal to 280, greater than or equal to 270 and less than or equal to 300, greater than or equal to 270 and less than or equal to 285, or greater than or equal to 280 and less than or equal to 300.

[0121] In embodiments, portion of paper articles comprising fibers doped with LiDAR-reflective black pigment according to embodiments disclosed and described herein have a reflectivity in the visible spectrum of electromagnetic radiation that is less than or equal to 10.0%, such as less than or equal to 9.5%, less than or equal to 9.0%, less than or equal to 8.5%, less than or equal to 8.0%, less than or equal to 7.5%, less than or equal to 7.0%, less than or equal to 6.5%, less than or equal to 6.0%, less than or equal to 5.5%, less than or equal to 5.0%, less than or equal to 4.5%, less than or equal to 4.0%, less than or equal to 3.5%, less than or equal to 3.0%, less than or equal to 2.5%, less than or equal to 2.0%, less than or equal to 1.5%, or less than or equal to 1.0%.

[0122] Portions of the paper articles comprising fibers doped with LiDAR-reflective black pigment according to embodiments disclosed and described herein have a reflectivity in the near-IR and / or LiDAR spectrum of electromagnetic radiation that is greater than or equal to 12%, such as greater than or equal to 15%, greater than or equal to 20%, greater than or equal to 25%, greater than or equal to 30%, or greater than or equal to 35%. In one or more embodiments, the portions of the paper articles comprising fibers doped with LiDAR-reflective black pigment according to embodiments disclosed and described herein may have a reflectivity in the near-IR and LiDAR spectrum of electromagnetic radiation (from 800 nm to 2500 nm) that is greater than or equal to 12% and less than or equal to 30%, such as greater than or equal to 15% and less than or equal to 30%, greater than or equal to 20% and less than or equal to 30%, or greater than or equal to 25% and less than or equal to 30%, greater than or equal to 12% and less than or equal to 25%, greater than or equal to 15% and less than or equal to 25%, greater than or equal to 20% and less than or equal to 25%, greater than or equal to 12% and less than or equal to 20%, greater than or equal to 15% and less than or equal to 20%, or greater than or equal to 12% and less than or equal to 15%.

[0123] Once formed, the paper articles disclosed and described above may be used in a number of applications. Namely, the paper articles comprising LiDAR-reflective black pigment can be used in any application where paper articles are currently use or could be used without limitation. One exemplary application of the paper article comprising LiDAR-reflective black pigment is as a backing material for adhesive products, such as a tape or sticker. This black, near-IR and / or LiDAR reflective tape may be use for construction, factory, or any other setting where near-IR or LiDAR reflectivity is advantageous, such as where autonomous vehicles and other autonomous equipment that use LiDAR-detecting cameras may be operating. By using a black near-IR and / or LiDAR reflective adhesive article, objects may be easily marked with near-IR and / or LiDAR reflective materials so that the object can be detected by autonomous equipment using LiDAR-detecting devices, but the object can be black and blend in to the factory setting for humans operating in the same space.

[0124] Another exemplary application of the LiDAR reflective paper is in aesthetic products, such as wallpaper, for settings that use LiDAR-based assistive technology, such as home or office environments where autonomous equipment, such as robotics, may be operating.

[0125] Another exemplary application of the LiDAR reflective paper is in security paper products, such as a banknote or identification documents for individuals or products. For instance, a security paper may incorporate a combination of LiDAR-reflective black pigment and normal black pigment (such as carbon black) so that only some of the black-colored features in the security paper reflect near-IR and / or LiDAR electromagnetic radiation, thus making the security paper more difficult to replicate.

[0126] Another example of the LiDAR reflective paper is in a temporary tattoo for identification purpose. Here again temporary tattoos may incorporate a combination of LiDAR-reflective black pigment and normal black pigment (such as carbon black) so that only some of the black-colored features in the temporary tattoo reflect near-IR and / or LiDAR electromagnetic radiation, thus making the security paper more difficult to replicate. The temporary tattoo could be used for events or areas where access is limited.

[0127] The above-listed uses are exemplary only, and additional uses may be contemplated as the need for near-IR and / or LiDAR-reflective paper articles become more prevalent as autonomous vehicles and other automated equipment that use near-IR and / or LiDAR detection become increasingly prevalent.Molded Articles

[0128] According to embodiments disclosed and described herein, LiDAR-reflective black pigments are incorporated into various molded articles, including those made by methods such as mechanical process, thermal process, dissolution process, or a combination thereof. Exemplary methods include mechanic processing, dissolution, latex blending, fine powder mixing, and resin curing. Other processes for making the non-woven articles include molding (e.g., injection molding, resin transfer molding, compression molding, foam molding, blow molding, jet molding, etc.), thermoforming, extrusion, filament winding, calendaring, spraying (including 3D printing), and pultrusion. Thermal processes include reversible and irreversible thermoplastic and thermosetting processes.

[0129] In one or more embodiments, the molded article is formed from a polymer. The polymer used in such embodiments is not particularly limited and can include polyamide, polyacrylonitrile, polyethylene terephthanlate (PET), polybutyrate, polyurethane, nylon, polyester, polymethyl methacrylate (PMMA), polyvinyl chloride (PVC), polypropylene, polystyrene (PS), polytetrafluoroethylene (PTFE), low-density polythene (LDPE), high-density polythene (HDPE), polyimides, polysiloxanes, polypropylene, epoxy, melamine formaldehyde, and phenol formaldehyde. The LiDAR-reflective black pigments disclosed and described herein may be added to the polymer during or after the polymerization process. In embodiments, the LiDAR-reflective black pigment may be added to a mixture of pre-polymers before the polymerization process such that the pre-polymers have a back color. In short, LiDAR-reflective pigments disclosed and described herein can be used in the polymerization process in a manner similar to the way that traditional pigments and other colorants are used in the polymerization process. In this way, black polymers that reflect near-IR and / or LiDAR electromagnetic radiation may be made. These black polymers may then be molded into polymeric articles that have high blackness and that reflect near-IR and / or LiDAR electromagnetic radiation.

[0130] According to embodiments, the polymeric article comprises from greater than or equal to 0.1 wt. % and less than or equal to 22 wt. % of LiDAR-reflective black pigment, such as greater than or equal to 0.1 wt. % and less than or equal to 5 wt. % of LiDAR-reflective black pigment, greater than or equal to 0.5 wt. % and less than or equal to 5.5 wt. % of LiDAR-reflective black pigment, greater than or equal to 1.5 wt. % and less than or equal to 6 wt. % of LiDAR-reflective black pigment, greater than or equal to 2.0 wt. % and less than or equal to 6.5 wt. % of LiDAR-reflective black pigment, greater than or equal to 3 wt. % and less than or equal to 7 wt. % of LiDAR-reflective black pigment, greater than or equal to 4 wt. % and less than or equal to 7.5 wt. % of LiDAR-reflective black pigment, greater than or equal to 1.5 wt. % and less than or equal to 4.5 wt. % of LiDAR-reflective black pigment, greater than or equal to 2.0 wt. % and less than or equal to 5 wt. % of LiDAR-reflective black pigment, greater than or equal to 3.0 wt. % and less than or equal to 5.5 wt. % of LiDAR-reflective black pigment, greater than or equal to 2 wt. % and less than or equal to 4 wt. % of LiDAR-reflective black pigment, greater than or equal to 2.5 wt. % and less than or equal to 4.5 wt. % of LiDAR-reflective black pigment, greater than or equal to 1 wt. % and less than or equal to 18 wt. % of LiDAR-reflective black pigment, greater than or equal to 1 wt. % and less than or equal to 12 wt. % of LiDAR-reflective black pigment, greater than or equal to 1 wt. % and less than or equal to 5 wt. % of LiDAR-reflective black pigment, greater than or equal to 5 wt. % and less than or equal to 20 wt. % of LiDAR-reflective black pigment, greater than or equal to 5 wt. % and less than or equal to 12 wt. % of LiDAR-reflective black pigment, greater than or equal to 10 wt. % and less than or equal to 22 wt. % of LiDAR-reflective black pigment, greater than or equal to 10 wt. % and less than or equal to 18 wt. % of LiDAR-reflective black pigment, greater than or equal to 15 wt. % and less than or equal to 22 wt. % of LiDAR-reflective black pigment, or greater than or equal to 18 wt. % and less than or equal to 22 wt. % of LiDAR-reflective black pigment.

[0131] The polymeric articles colored with the LiDAR-reflective black pigment according to embodiments disclosed and described herein have a blackness My that is greater than or equal to 125 and less than or equal to 300. In some embodiments, the polymeric articles colored with the LiDAR-reflective black pigment according to embodiments disclosed and described herein may have a blackness My that is greater than or equal to 125 and less than or equal to 165, such as greater than or equal to 130 and less than or equal to 160, greater than or equal to 135 and less than or equal to 155, greater than or equal to 140 and less than or equal to 150, greater than or equal to 145 and less than or equal to 165, greater than or equal to 145 and less than or equal to 160, greater than or equal to 155 and less than or equal to 165, greater than or equal to 160 and less than or equal to 165, or greater than or equal to 150 and less than or equal to 160. In some embodiments, the polymeric articles colored with the LiDAR-reflective black pigment according to embodiments disclosed and described herein may have a blackness My that is greater than or equal to 155 and less than or equal to 240, such as greater than or equal to 160 and less than or equal to 230, greater than or equal to 170 and less than or equal to 210, greater than or equal to 180 and less than or equal to 200, greater than or equal to 190 and less than or equal to 240, greater than or equal to 195 and less than or equal to 230, greater than or equal to 210 and less than or equal to 240, greater than or equal to 170 and less than or equal to 205, or greater than or equal to 200 and less than or equal to 215. In other embodiments, the polymeric articles colored with the LiDAR-reflective black pigment according to embodiments disclosed and described herein may have a blackness My that is greater than or equal to 230 and less than or equal to 300, such as greater than or equal to 230 and less than or equal to 275, greater than or equal to 230 and less than or equal to 250, greater than or equal to 240 and less than or equal to 280, greater than or equal to 240 and less than or equal to 260, greater than or equal to 250 and less than or equal to 300, greater than or equal to 250 and less than or equal to 280, greater than or equal to 260 and less than or equal to 295, greater than or equal to 260 and less than or equal to 280, greater than or equal to 270 and less than or equal to 300, greater than or equal to 270 and less than or equal to 285, or greater than or equal to 280 and less than or equal to 300.

[0132] In embodiments, the polymeric articles colored with the LiDAR-reflective black pigment have a reflectivity in the visible spectrum of electromagnetic radiation that is less than or equal to 10.0%, such as less than or equal to 9.5%, less than or equal to 9.0%, less than or equal to 8.5%, less than or equal to 8.0%, less than or equal to 7.5%, less than or equal to 7.0%, less than or equal to 6.5%, less than or equal to 6.0%, less than or equal to 5.5%, less than or equal to 5.0%, less than or equal to 4.5%, less than or equal to 4.0%, less than or equal to 3.5%, less than or equal to 3.0%, less than or equal to 2.5%, less than or equal to 2.0%, less than or equal to 1.5%, or less than or equal to 1.0%.

[0133] Portions of the polymeric articles colored with the LiDAR-reflective black pigment according to embodiments disclosed and described herein has been applied have a reflectivity in the near-IR and / or LiDAR spectrum of electromagnetic radiation that is greater than or equal to 12%, such as greater than or equal to 15%, greater than or equal to 20%, greater than or equal to 25%, greater than or equal to 30%, or greater than or equal to 35%. In one or more embodiments, the portions of the polymeric articles colored with the LiDAR-reflective black pigment according to embodiments disclosed and described herein has been applied may have a reflectivity in the near-IR and LiDAR spectrum of electromagnetic radiation (from 800 nm to 2500 nm) that is greater than or equal to 12% and less than or equal to 30%, such as greater than or equal to 15% and less than or equal to 30%, greater than or equal to 20% and less than or equal to 30%, or greater than or equal to 25% and less than or equal to 30%, greater than or equal to 12% and less than or equal to 25%, greater than or equal to 15% and less than or equal to 25%, greater than or equal to 20% and less than or equal to 25%, greater than or equal to 12% and less than or equal to 20%, greater than or equal to 15% and less than or equal to 20%, or greater than or equal to 12% and less than or equal to 15%.

[0134] According to one or more embodiments, the molded article may be a natural or synthetic elastomer, such as, for example, vulcanized or thermoplastics. The elastomer, in embodiments may be natural or synthetic rubber, including silicone rubber, nitrile rubber, styrene-butadiene, chlorpene, cis-polyisoprene, cis-polybutadiene, ethylene-propylene, and the like. As was the case with the polymeric materials discussed above, the LiDAR-reflective black pigment according to embodiments disclosed and described herein may be added to the elastomer at any point before, during, or after the manufacturing process in the same manner as traditional pigments and colorants. By adding the LiDAR-reflective black pigment according to embodiments disclosed and described herein to an elastomer, elastomeric articles that have a black color and the reflect near-IR and LiDAR electromagnetic radiation can be formed.

[0135] According to embodiments, the elastomeric article comprises from greater than or equal to 0.1 wt. % and less than or equal to 22 wt. % of LiDAR-reflective black pigment, such as greater than or equal to 0.1 wt. % and less than or equal to 5 wt. % of LiDAR-reflective black pigment, greater than or equal to 0.5 wt. % and less than or equal to 5.5 wt. % of LiDAR-reflective black pigment, greater than or equal to 1.5 wt. % and less than or equal to 6 wt. % of LiDAR-reflective black pigment, greater than or equal to 2.0 wt. % and less than or equal to 6.5 wt. % of LiDAR-reflective black pigment, greater than or equal to 3 wt. % and less than or equal to 7 wt. % of LiDAR-reflective black pigment, greater than or equal to 4 wt. % and less than or equal to 7.5 wt. % of LiDAR-reflective black pigment, greater than or equal to 1.5 wt. % and less than or equal to 4.5 wt. % of LiDAR-reflective black pigment, greater than or equal to 2.0 wt. % and less than or equal to 5 wt. % of LiDAR-reflective black pigment, greater than or equal to 3.0 wt. % and less than or equal to 5.5 wt. % of LiDAR-reflective black pigment, greater than or equal to 2 wt. % and less than or equal to 4 wt. % of LiDAR-reflective black pigment, greater than or equal to 2.5 wt. % and less than or equal to 4.5 wt. % of LiDAR-reflective black pigment, greater than or equal to 1 wt. % and less than or equal to 18 wt. % of LiDAR-reflective black pigment, greater than or equal to 1 wt. % and less than or equal to 12 wt. % of LiDAR-reflective black pigment, greater than or equal to 1 wt. % and less than or equal to 5 wt. % of LiDAR-reflective black pigment, greater than or equal to 5 wt. % and less than or equal to 20 wt. % of LiDAR-reflective black pigment, greater than or equal to 5 wt. % and less than or equal to 12 wt. % of LiDAR-reflective black pigment, greater than or equal to 10 wt. % and less than or equal to 22 wt. % of LiDAR-reflective black pigment, greater than or equal to 10 wt. % and less than or equal to 18 wt. % of LiDAR-reflective black pigment, greater than or equal to 15 wt. % and less than or equal to 22 wt. % of LiDAR-reflective black pigment, or greater than or equal to 18 wt. % and less than or equal to 22 wt. % of LiDAR-reflective black pigment.

[0136] The elastomeric articles colored with the LiDAR-reflective black pigment according to embodiments disclosed and described herein have a blackness My that is greater than or equal to 125 and less than or equal to 300. In some embodiments, the elastomeric articles colored with the LiDAR-reflective black pigment according to embodiments disclosed and described herein may have a blackness My that is greater than or equal to 125 and less than or equal to 165, such as greater than or equal to 130 and less than or equal to 160, greater than or equal to 135 and less than or equal to 155, greater than or equal to 140 and less than or equal to 150, greater than or equal to 145 and less than or equal to 165, greater than or equal to 145 and less than or equal to 160, greater than or equal to 155 and less than or equal to 165, greater than or equal to 160 and less than or equal to 165, or greater than or equal to 150 and less than or equal to 160. In some embodiments, the elastomeric articles colored with the LiDAR-reflective black pigment according to embodiments disclosed and described herein may have a blackness My that is greater than or equal to 155 and less than or equal to 240, such as greater than or equal to 160 and less than or equal to 230, greater than or equal to 170 and less than or equal to 210, greater than or equal to 180 and less than or equal to 200, greater than or equal to 190 and less than or equal to 240, greater than or equal to 195 and less than or equal to 230, greater than or equal to 210 and less than or equal to 240, greater than or equal to 170 and less than or equal to 205, or greater than or equal to 200 and less than or equal to 215. In other embodiments, the elastomeric articles colored with the LiDAR-reflective black pigment according to embodiments disclosed and described herein may have a blackness My that is greater than or equal to 230 and less than or equal to 300, such as greater than or equal to 230 and less than or equal to 275, greater than or equal to 230 and less than or equal to 250, greater than or equal to 240 and less than or equal to 280, greater than or equal to 240 and less than or equal to 260, greater than or equal to 250 and less than or equal to 300, greater than or equal to 250 and less than or equal to 280, greater than or equal to 260 and less than or equal to 295, greater than or equal to 260 and less than or equal to 280, greater than or equal to 270 and less than or equal to 300, greater than or equal to 270 and less than or equal to 285, or greater than or equal to 280 and less than or equal to 300.

[0137] In embodiments, the elastomeric articles colored with the LiDAR-reflective black pigment have a reflectivity in the visible spectrum of electromagnetic radiation that is less than or equal to 10.0%, such as less than or equal to 9.5%, less than or equal to 9.0%, less than or equal to 8.5%, less than or equal to 8.0%, less than or equal to 7.5%, less than or equal to 7.0%, less than or equal to 6.5%, less than or equal to 6.0%, less than or equal to 5.5%, less than or equal to 5.0%, less than or equal to 4.5%, less than or equal to 4.0%, less than or equal to 3.5%, less than or equal to 3.0%, less than or equal to 2.5%, less than or equal to 2.0%, less than or equal to 1.5%, or less than or equal to 1.0%.

[0138] Portions of the elastomeric articles colored with the LiDAR-reflective black pigment according to embodiments disclosed and described herein has been applied have a reflectivity in the near-IR and / or LiDAR spectrum of electromagnetic radiation that is greater than or equal to 12%, such as greater than or equal to 15%, greater than or equal to 20%, greater than or equal to 25%, greater than or equal to 30%, or greater than or equal to 35%. In one or more embodiments, the portions of the elastomeric articles colored with the LiDAR-reflective black pigment according to embodiments disclosed and described herein may have a reflectivity in the near-IR and LiDAR spectrum of electromagnetic radiation (from 800 nm to 2500 nm) that is greater than or equal to 12% and less than or equal to 30%, such as greater than or equal to 15% and less than or equal to 30%, greater than or equal to 20% and less than or equal to 30%, or greater than or equal to 25% and less than or equal to 30%, greater than or equal to 12% and less than or equal to 25%, greater than or equal to 15% and less than or equal to 25%, greater than or equal to 20% and less than or equal to 25%, greater than or equal to 12% and less than or equal to 20%, greater than or equal to 15% and less than or equal to 20%, or greater than or equal to 12% and less than or equal to 15%.

[0139] Articles that can be made by molding are limitless and include, furniture, building materials (both structural and decorative), components of vehicles (including automobiles, aircraft, boats, recreation vehicles, trailers, and the like), consumer electronics, consumer products (bottles, caps, containers, and the like), plastic bags, films, protective equipment (including helmets and body pads), tires, physical markers, signs, and the like.Non-Woven Textile Articles

[0140] Non-woven fabrics are broadly defined as web structures bonded together by entangling fibers mechanically, thermally fusing the fibers, or chemically bonding the fibers together. Nonwovens may be a sheet, web, or bat of natural and / or man-made fibers or filaments, excluding paper, that have not been converted into yarns.

[0141] Numerous methods for bonding the fibers include: mixing with an adhesive; thermally fusing the fibers to each other or to the other melt able fibers or powders; fusing fibers by first dissolving, and then re-solidifying their surfaces; creating physical tangles or tuft among the fibers; stitching the fibers or filaments in place. Thus, non-wovens are not made by weaving or knitting and do not require converting the fibers to yarn. Nonwoven fabrics are engineered fabrics that may be single-use or a very durable fabric.

[0142] Non-woven manufacturing can be described as a series of manufacturing steps consisting of forming a fibrous web, entangling or bonding the fibers in the web to impart mechanical integrity to the structure and finishing the fabric to impart some special properties to the fabric that the customer specifies. Exemplary methods for manufacturing non-woven articles will now be described.

[0143] Methods for forming webs is determined by fiber length. One methods forms a web from staple-length fibers based on the textile carding process, whereas web formation from short fibers may be based on a wet laid process similar papermaking. An additional method forms a web directly from filaments immediately as they exit an extruder (spun laid).

[0144] Fibrous webs have little mechanical strength and a further manufacturing process is utilized to form a fabric with useful properties. One such method is needle punching where non-woven web structures are bonded by mechanically interlocking the fibers through the web. Barbed needles, mounted on a board, punch fibers into the web and then are withdrawn leaving fibers entangled. The needles are spaced in a non-aligned arrangement are designed to release the fiber as the needle board is withdrawn. Another method is stitch bonding where fiber webs are bound by knitting elements with or without yarn to interlock the fibers. Thermal bonding is a process of using heat to bond or stabilize a web structure that consists of a thermoplastic fiber. All part of the fibers act as thermal binders, thus eliminating the use of latex or resin binders. In this method the fiber web may be passed between heated calendar rollers, where the web is bonded. Use of smooth rolls bonds the entire surface of the fabric increasing the strength, but reduces drape and softness. Chemical bonding is a process of bonding a web by means of a chemical and is one of the most common methods of bonding. The chemical binder is applied to the web and is cured. The most commonly used binder is latex, because it is economical, easy to apply and very effective. Several methods are used to apply the binder and include saturation bonding, spray bonding, print bonding and foam bonding. Hydro entanglement is a process of using fluid forces to lock the fibers together. This is achieved by fine water jets directed through the web, which is supported by a conveyor belt. Entanglement occurs when the water strikes the web and the fibers are deflected. The vigorous agitation within the web causes the fibers to become entangled.

[0145] After the web structure is formed, the web can be finished. Finishing includes operations such as coating and laminating, calendaring and embossing to impart particular surface properties, corona and plasma treatments to change the wetting properties of the fabric, wet chemical treatments to impart anti-stat properties, anti-microbial properties, flame retardant properties etc. After finishing the fabric, it may be cut to width and rewound for shipment.

[0146] Non-woven materials may be used in numerous applications, including baby diapers, adult incontinence products, wet wipes, surgical drapes and covers, liquid cartridge and bag filters, face masks, air-conditioning filters, soil stabilizers and roadway underlayment, erosion control, drainage systems, insulation (fiberglass batting), pillows, cushions, and upholstery padding, carpet backing, automotive headliners and upholstery, house wraps, and disposable clothing (foot coverings, coveralls).

[0147] According to embodiments, a non-woven article may be made by doping a fiber or a filament with a LiDAR-reflective black pigment according to embodiments disclosed and described herein. These doped fibers or filaments may then be use to form a non-woven article. The phrase “fiber” as used herein refers to a short, ultrafine strand having a diameter of greater than or equal to 1 μm and less than or equal to 50 μm, such as greater than or equal to 15 μm and less than or equal to 45 μm, greater than or equal to 20 μm and less than or equal to 40 μm, or greater than or equal to 25 μm and less than or equal to 35 μm. The fibers may be formed by melt blowing, cutting, milling, and the like. The phrase “filament” used herein refers to a long, continuous strand with a diameter of that is greater than or equal to 9 nm and less than or equal to 3.0 mm, such as greater than or equal to 50 nm and less than or equal to 2.5 mm, greater than or equal to 100 nm and less than or equal to 2.0 mm, greater than or equal to 150 nm and less than or 1.5 mm, greater than or equal to 200 nm and less than or equal to 1.0 mm, or greater than or equal to 500 nm and less than or equal to 0.5 mm. A filament may be formed by spinning processes including electrospinning, melt spinning and the like.

[0148] The doping ratio of the doped fibers or filaments (e.g., the amount of LiDAR-reflective black pigment in the fiber) is greater than or equal to 0.1 wt. % and less than or equal to 22 wt. %, such as greater than or equal to 0.1 wt. % and less than or equal to 5 wt. %, greater than or equal to 0.5 wt. % and less than or equal to 5.5 wt. %, greater than or equal to 1.5 wt. % and less than or equal to 6 wt. %, greater than or equal to 2.0 wt. % and less than or equal to 6.5 wt. %, greater than or equal to 3 wt. % and less than or equal to 7 wt. %, greater than or equal to 4 wt. % and less than or equal to 7.5 wt. %, greater than or equal to 1.5 wt. % and less than or equal to 4.5 wt. %, greater than or equal to 2.0 wt. % and less than or equal to 5 wt. %, greater than or equal to 3.0 wt. % and less than or equal to 5.5 wt. %, greater than or equal to 2 wt. % and less than or equal to 4 wt. %, greater than or equal to 2.5 wt. % and less than or equal to 4.5 wt. %, greater than or equal to 1 wt. % and less than or equal to 18 wt. %, greater than or equal to 1 wt. % and less than or equal to 12 wt. %, greater than or equal to 1 wt. % and less than or equal to 5 wt. %, greater than or equal to 5 wt. % and less than or equal to 20 wt. %, greater than or equal to 5 wt. % and less than or equal to 12 wt. %, greater than or equal to 10 wt. % and less than or equal to 22 wt. %, greater than or equal to 10 wt. % and less than or equal to 18 wt. %, greater than or equal to 15 wt. % and less than or equal to 22 wt. %, or greater than or equal to 18 wt. % and less than or equal to 22 wt. %.

[0149] In embodiments, portions of the non-woven article comprising fibers or filaments doped with LiDAR-reflective black pigment according to embodiments disclosed and described herein have a blackness My that is greater than or equal to 125 and less than or equal to 300. In some embodiments, the portions of the non-woven article comprising fibers or filaments doped with LiDAR-reflective black pigment according to embodiments disclosed and described herein may have a blackness My that is greater than or equal to 125 and less than or equal to 165, such as greater than or equal to 130 and less than or equal to 160, greater than or equal to 135 and less than or equal to 155, greater than or equal to 140 and less than or equal to 150, greater than or equal to 145 and less than or equal to 165, greater than or equal to 145 and less than or equal to 160, greater than or equal to 155 and less than or equal to 165, greater than or equal to 160 and less than or equal to 165, or greater than or equal to 150 and less than or equal to 160. In some embodiments, the portions of the non-woven article comprising fibers or filaments doped with LiDAR-reflective black pigment according to embodiments disclosed and described herein may have a blackness My that is greater than or equal to 155 and less than or equal to 240, such as greater than or equal to 160 and less than or equal to 230, greater than or equal to 170 and less than or equal to 210, greater than or equal to 180 and less than or equal to 200, greater than or equal to 190 and less than or equal to 240, greater than or equal to 195 and less than or equal to 230, greater than or equal to 210 and less than or equal to 240, greater than or equal to 170 and less than or equal to 205, or greater than or equal to 200 and less than or equal to 215. In other embodiments, the portions of the non-woven article comprising fibers or filaments doped with LiDAR-reflective black pigment according to embodiments disclosed and described herein may have a blackness My that is greater than or equal to 230 and less than or equal to 300, such as greater than or equal to 230 and less than or equal to 275, greater than or equal to 230 and less than or equal to 250, greater than or equal to 240 and less than or equal to 280, greater than or equal to 240 and less than or equal to 260, greater than or equal to 250 and less than or equal to 300, greater than or equal to 250 and less than or equal to 280, greater than or equal to 260 and less than or equal to 295, greater than or equal to 260 and less than or equal to 280, greater than or equal to 270 and less than or equal to 300, greater than or equal to 270 and less than or equal to 285, or greater than or equal to 280 and less than or equal to 300.

[0150] In embodiments, portions of the non-woven article comprising fibers or filaments doped with LiDAR-reflective black pigment according to embodiments disclosed and described herein have a reflectivity in the visible spectrum of electromagnetic radiation that is less than or equal to 10.0%, such as less than or equal to 9.5%, less than or equal to 9.0%, less than or equal to 8.5%, less than or equal to 8.0%, less than or equal to 7.5%, less than or equal to 7.0%, less than or equal to 6.5%, less than or equal to 6.0%, less than or equal to 5.5%, less than or equal to 5.0%, less than or equal to 4.5%, less than or equal to 4.0%, less than or equal to 3.5%, less than or equal to 3.0%, less than or equal to 2.5%, less than or equal to 2.0%, less than or equal to 1.5%, or less than or equal to 1.0%.

[0151] Portions of the non-woven article comprising fibers or filaments doped with LiDAR-reflective black pigment according to embodiments disclosed and described herein have a reflectivity in the near-IR and / or LiDAR spectrum of electromagnetic radiation that is greater than or equal to 12%, such as greater than or equal to 15%, greater than or equal to 20%, greater than or equal to 25%, greater than or equal to 30%, or greater than or equal to 35%. In one or more embodiments, the portions of the non-woven article comprising fibers or filaments doped with LiDAR-reflective black pigment according to embodiments disclosed and described herein may have a reflectivity in the near-IR and LiDAR spectrum of electromagnetic radiation (from 800 nm to 2500 nm) that is greater than or equal to 12% and less than or equal to 30%, such as greater than or equal to 15% and less than or equal to 30%, greater than or equal to 20% and less than or equal to 30%, or greater than or equal to 25% and less than or equal to 30%, greater than or equal to 12% and less than or equal to 25%, greater than or equal to 15% and less than or equal to 25%, greater than or equal to 20% and less than or equal to 25%, greater than or equal to 12% and less than or equal to 20%, greater than or equal to 15% and less than or equal to 20%, or greater than or equal to 12% and less than or equal to 15%.

[0152] In embodiments where only a portion of the non-woven article includes the LiDAR-reflective black pigment, the portion that includes the LiDAR-reflective black pigment may be a pattern or design, such as a glyph, bar code, or QR code, or decorative image.

[0153] One example application of the LiDAR-reflecting black non-woven articles is incorporation into work clothes, such as uniforms and personal protection equipment, for setting with autonomous vehicles and other autonomous equipment that use LiDAR. Another example application is incorporation into clothes made from 3D-printed, quasi-woven smart textiles that actuate, attenuate, or redirect LiDAR reflection according to temperature, body movement, or other external stimuli. Utilization of LiDAR-reflecting CuO crystallites allow 3D imaging using LiDAR equipment.Other Articles

[0154] As described above, LiDAR-reflecting black pigments can be used to form fibers and filaments. These LiDAR-reflecting black fibers and filaments can be incorporated into a number articles to make LiDAR-reflecting black articles. For example, the LiDAR-reflecting black pigments can be incorporated into fiberglass or carbon fiber articles to incorporate LiDAR-reflecting properties to the fiberglass or carbon fiber article. In addition, LiDAR-reflective black pigments may be incorporated into nearly any manufacturing process where pigments or other colorants are used without altering the manufacturing process to convert generic black articles into LiDAR-reflective black articles. For instance, a laminated article may include a layer comprising LiDAR-reflecting black pigment, fibers, or filaments that allow the laminated article to have a black color and reflect near-IR and LiDAR electromagnetic radiation.

[0155] The doping ratio of the doped fibers, filaments, or pigment in the article is greater than or equal to 0.1 wt. % and less than or equal to 22 wt. %, such as greater than or equal to 0.1 wt. % and less than or equal to 5 wt. %, greater than or equal to 0.5 wt. % and less than or equal to 5.5 wt. %, greater than or equal to 1.5 wt. % and less than or equal to 6 wt. %, greater than or equal to 2.0 wt. % and less than or equal to 6.5 wt. %, greater than or equal to 3 wt. % and less than or equal to 7 wt. %, greater than or equal to 4 wt. % and less than or equal to 7.5 wt. %, greater than or equal to 1.5 wt. % and less than or equal to 4.5 wt. %, greater than or equal to 2.0 wt. % and less than or equal to 5 wt. %, greater than or equal to 3.0 wt. % and less than or equal to 5.5 wt. %, greater than or equal to 2 wt. % and less than or equal to 4 wt. %, greater than or equal to 2.5 wt. % and less than or equal to 4.5 wt. %, greater than or equal to 1 wt. % and less than or equal to 18 wt. %, greater than or equal to 1 wt. % and less than or equal to 12 wt. %, greater than or equal to 1 wt. % and less than or equal to 5 wt. %, greater than or equal to 5 wt. % and less than or equal to 20 wt. %, greater than or equal to 5 wt. % and less than or equal to 12 wt. %, greater than or equal to 10 wt. % and less than or equal to 22 wt. %, greater than or equal to 10 wt. % and less than or equal to 18 wt. %, greater than or equal to 15 wt. % and less than or equal to 22 wt. %, or greater than or equal to 18 wt. % and less than or equal to 22 wt. %.

[0156] In embodiments, portions of the article comprising fibers or filaments doped with LiDAR-reflective black pigment according to embodiments disclosed and described herein have a blackness My that is greater than or equal to 125 and less than or equal to 300. In some embodiments, the portions of the article comprising fibers or filaments doped with LiDAR-reflective black pigment according to embodiments disclosed and described herein may have a blackness My that is greater than or equal to 125 and less than or equal to 165, such as greater than or equal to 130 and less than or equal to 160, greater than or equal to 135 and less than or equal to 155, greater than or equal to 140 and less than or equal to 150, greater than or equal to 145 and less than or equal to 165, greater than or equal to 145 and less than or equal to 160, greater than or equal to 155 and less than or equal to 165, greater than or equal to 160 and less than or equal to 165, or greater than or equal to 150 and less than or equal to 160. In some embodiments, the portions of the article comprising fibers or filaments doped with LiDAR-reflective black pigment according to embodiments disclosed and described herein may have a blackness My that is greater than or equal to 155 and less than or equal to 240, such as greater than or equal to 160 and less than or equal to 230, greater than or equal to 170 and less than or equal to 210, greater than or equal to 180 and less than or equal to 200, greater than or equal to 190 and less than or equal to 240, greater than or equal to 195 and less than or equal to 230, greater than or equal to 210 and less than or equal to 240, greater than or equal to 170 and less than or equal to 205, or greater than or equal to 200 and less than or equal to 215. In other embodiments, the portions of the article comprising fibers or filaments doped with LiDAR-reflective black pigment according to embodiments disclosed and described herein may have a blackness My that is greater than or equal to 230 and less than or equal to 300, such as greater than or equal to 230 and less than or equal to 275, greater than or equal to 230 and less than or equal to 250, greater than or equal to 240 and less than or equal to 280, greater than or equal to 240 and less than or equal to 260, greater than or equal to 250 and less than or equal to 300, greater than or equal to 250 and less than or equal to 280, greater than or equal to 260 and less than or equal to 295, greater than or equal to 260 and less than or equal to 280, greater than or equal to 270 and less than or equal to 300, greater than or equal to 270 and less than or equal to 285, or greater than or equal to 280 and less than or equal to 300.

[0157] In embodiments, portions of the article comprising LiDAR-reflective fibers, filaments, or pigment according to embodiments disclosed and described herein have a reflectivity in the visible spectrum of electromagnetic radiation that is less than or equal to 10.0%, such as less than or equal to 9.5%, less than or equal to 9.0%, less than or equal to 8.5%, less than or equal to 8.0%, less than or equal to 7.5%, less than or equal to 7.0%, less than or equal to 6.5%, less than or equal to 6.0%, less than or equal to 5.5%, less than or equal to 5.0%, less than or equal to 4.5%, less than or equal to 4.0%, less than or equal to 3.5%, less than or equal to 3.0%, less than or equal to 2.5%, less than or equal to 2.0%, less than or equal to 1.5%, or less than or equal to 1.0%.

[0158] Portions of the non-woven article comprising LiDAR-reflective fibers, filaments, or pigment according to embodiments disclosed and described herein have a reflectivity in the near-IR and / or LiDAR spectrum of electromagnetic radiation that is greater than or equal to 12%, such as greater than or equal to 15%, greater than or equal to 20%, greater than or equal to 25%, greater than or equal to 30%, or greater than or equal to 35%. In one or more embodiments, the portions of the non-woven article comprising LiDAR-reflective fibers, filaments, or pigment according to embodiments disclosed and described herein may have a reflectivity in the near-IR and LiDAR spectrum of electromagnetic radiation (from 800 nm to 2500 nm) that is greater than or equal to 12% and less than or equal to 30%, such as greater than or equal to 15% and less than or equal to 30%, greater than or equal to 20% and less than or equal to 30%, or greater than or equal to 25% and less than or equal to 30%, greater than or equal to 12% and less than or equal to 25%, greater than or equal to 15% and less than or equal to 25%, greater than or equal to 20% and less than or equal to 25%, greater than or equal to 12% and less than or equal to 20%, greater than or equal to 15% and less than or equal to 20%, or greater than or equal to 12% and less than or equal to 15%.

[0159] In embodiments where only a portion of the article includes the LiDAR-reflective black pigment, the portion that includes the LiDAR-reflective black pigment may be a pattern or design, such as a glyph, bar code, or QR code, or decorative image.EXAMPLES

[0160] Embodiments will now be further clarified by the following examples

[0161] The reflectance behavior of paint samples incorporated with dark-colored pigments are compared. Samples include two types of CuO crystallites: N—CuO-A has a crystal size about 100 Å and a (111) / (−111) ratio near 1. N—CuO—C has a crystal size about 204 Å and a (111) / (−111) ratio near 1.1. Chromium iron oxide based near infrared (NIR) reflective black pigments, HEUCODUR HD 910, was obtained from Heucotech LTD (denoted as “cool black”). Carbon black, MONARCH900, was obtained from Cabot Corporation (denoted as “carbon black”).

[0162] Crystallographic information of CuO nanoparticles were investigated using powder X-ray diffraction (XRD, Japan, Rigaku Miniflex 600) with Cu Kα radiation (λ=0.1541 nm). The average crystallite size t of prepared particles was estimated from the measured width of their XRD diffraction curves by using Scherrer's formula.τ=k⁢λβ⁢cos⁢θ(2)

[0163] Here k is a dimensionless shape factor with a value close to unity. λ represents the wavelength of the X-ray radiation, β is the line broadening at half the maximum intensity (FWHM) and θ is the Bragg's angle.

[0164] Optical properties of painted panels were studied by UV / Vis / NIR spectrophotometers (USA Agilent Cary 7000). The bandgap calculation is based on the Kubelka-Munk function F(R∞) which is related to the diffuse reflectance, R∞, of the sample by the relation below:F⁡(R∞)=(1-R∞)2 / 2⁢R∞(3)Here, R∞ is the absolute value of reflectance and F(R∞) is equivalent to the absorption coefficient. The indirect bandgap of samples was estimated by plotting (F(R_∞) hν)0.5 versus energy. The linear part of the curve was extrapolated to (F(R_∞) hν)0.5=0 to obtain the indirect bandgap energy.The degree of blackness My of painted samples was evaluated by X-Rite Ci7600 benchtop spectrophotometer (USA, X-Rite) that directly related to the reference provided by the instrument.MY=100⁢ log⁢ (Yn / Y)(4)Where Yn=100.000 is one of the CIE White Point values for D65 / 10 conditions. Y are one of the CIE tristimulus values for the sample being measured.

[0167] The reflectance spectra shows that the paint sample incorporated with N—CuO-A offers an elegant black color with nearly full absorption in visible light, which is similar to carbon black, but retains NIR reflectivity with the maximum peak close to 905 nm. The measure of blackness shows a My value as high as 135.5. Comparatively, a paint containing carbon black exhibits very low reflection (less than 1%) throughout the visible and NIR wavelength, resulting in a high blackness value of around 135. Paints with N—CuO—C have higher NIR reflectivity selectively between 900 and 1000 nm, but they show distinguishable reflection in the visible wavelength, particularly in red hue, resulting in the appearance of an obvious brownish tone, with a blackness value less than 130. In contrast, the “cool black” sample shows strong reflection at the deeper end of the NIR spectra greater than 905 nm yet does not sufficiently absorb in the visible wavelengths, with a blackness value of 128.

[0168] While particular embodiments have been illustrated and described herein, it should be understood that various other changes and modifications may be made without departing from the spirit and scope of the claimed subject matter. Moreover, although various aspects of the claimed subject matter have been described herein, such aspects need not be utilized in combination. It is therefore intended that the appended claims cover all such changes and modifications that are within the scope of the claimed subject matter.

Claims

1. A paper article comprising:a matrix made from pulp; anda pigment having a reflectivity in the visible spectrum of electromagnetic radiation that is less than or equal to 10.0%, and a reflectivity in the near-IR and LiDAR spectrum of electromagnetic radiation that is greater than or equal to 12%.

2. The paper article of claim 1, wherein the pulp is dyed with the pigment.

3. The paper article of claim 2, wherein the paper article has a reflectivity in the visible spectrum of electromagnetic radiation that is less than or equal to 10.0%, and a reflectivity in the near-IR and LiDAR spectrum of electromagnetic radiation that is greater than or equal to 12%.

4. The paper article of claim 1, wherein the paper article comprises greater than or equal to 0.1 wt. % and less than or equal to 22 wt. % of the pigment.

5. The paper article of claim 1, wherein the paper article has a blackness My that is greater than or equal to 125 and less than or equal to 300.

6. The paper article of claim 1, wherein the pigment is applied to at least a portion of the paper article by a liquidus marking material.

7. The paper article of claim 6, wherein the liquidus marking material comprises greater than or equal to 0.1 wt. % and less than or equal to 22 wt. % of the pigment.

8. The paper article of claim 6, wherein the portion of the paper article has a reflectivity in the visible spectrum of electromagnetic radiation that is less than or equal to 10.0%, and a reflectivity in the near-IR and LiDAR spectrum of electromagnetic radiation that is greater than or equal to 12%.

9. The paper article of claim 6, wherein the portion of the paper article has a blackness My that is greater than or equal to 125 and less than or equal to 300.

10. The paper article of claim 1, wherein the pigment is incorporated into the paper article as a fiber.

11. The paper article of claim 10, wherein the fiber has a diameter of greater than or equal to 1 μm and less than or equal to 50 μm.

12. The paper article of claim 10, wherein the fiber comprises greater than or equal to 0.1 wt. % and less than or equal to 22 wt. % of the pigment.

13. The paper article of claim 10, wherein at least a portion of the paper article comprises the fibers.

14. The paper article of claim 13, wherein the portion of the paper article has a reflectivity in the visible spectrum of electromagnetic radiation that is less than or equal to 10.0%, and a reflectivity in the near-IR and LiDAR spectrum of electromagnetic radiation that is greater than or equal to 12%.

15. The paper article of claim 13, wherein the portion of the paper article has a blackness My that is greater than or equal to 125 and less than or equal to 300.

16. The paper article of claim 6, wherein in the portion of the paper article is a unique design.

17. The paper article of claim 16, wherein the unique design is a glyph, bar code, or QR code, or decorative image.

18. The paper article of claim 1, wherein the pigment is copper oxide nano-crystallites.

19. The paper article of claim 18, wherein the copper oxide crystallites have an average particle size that is greater than or equal to 5 nm and less than or equal to 15 nm.

20. The paper article claim 18, wherein the copper oxide crystallites have a ratio of (−111) / (111) greater than or equal to 0.5 and less than or equal to 1.5.

21. A tape, sticker, wallpaper, security paper, or temporary tattoo comprising the paper article of claim 1.

22. A molded article comprising:a polymer; anda pigment having a reflectivity in the visible spectrum of electromagnetic radiation that is less than or equal to 10.0%, and a reflectivity in the near-IR and LiDAR spectrum of electromagnetic radiation that is greater than or equal to 12%.

23. The molded article of claim 22, wherein the molded article comprises greater than or equal to 0.1 wt. % and less than or equal to 22 wt. % of the pigment.

24. The molded article of claim 22, wherein the molded article has a blackness My that is greater than or equal to 125 and less than or equal to 300.

25. The molded article of claim 22, wherein the molded article has a reflectivity in the visible spectrum of electromagnetic radiation that is less than or equal to 10.0%, and a reflectivity in the near-IR and LiDAR spectrum of electromagnetic radiation that is greater than or equal to 12%.

26. The molded article of claim 22, wherein the polymer is selected from the group consisting of polyamide, polyacrylonitrile, polyethylene terephthanlate (PET), polybutyrate, polyurethane, nylon, polyester, polymethyl methacrylate (PMMA), polyvinyl chloride (PVC), polypropylene, polystyrene (PS), polytetrafluoroethylene (PTFE), low-density polythene (LDPE), high-density polythene (HDPE), polyimides, polysiloxanes, polypropylene, epoxy, melamine formaldehyde, and phenol formaldehyde.

27. The molded article of claim 22, wherein the polymer is a natural or synthetic elastomer.

28. The molded article of claim 27, wherein the elastomer is selected from the group consisting silicone rubber, nitrile rubber, styrene-butadiene, chlorpene, cis-polyisoprene, cis-polybutadiene, and ethylene-propylene.

29. The molded article of claim 22, wherein the pigment is copper oxide nano-crystallites.

30. The molded article of claim 29, wherein the copper oxide crystallites have an average particle size that is greater than or equal to 5 nm and less than or equal to 15 nm.

31. The molded article of claim 29, wherein the copper oxide crystallites have a ratio of (−111) / (111) greater than or equal to 0.5 and less than or equal to 1.5.

32. The molded article of claim 22, wherein the molded article is furniture, a building material, a vehicle component, a consumer electronic component, a consumer product, a plastic bag, a film, protective equipment, a tire, a physical marker, or a sign.

33. A non-woven article comprising:a plurality of fibers; anda pigment having a reflectivity in the visible spectrum of electromagnetic radiation that is less than or equal to 10.0%, and a reflectivity in the near-IR and LiDAR spectrum of electromagnetic radiation that is greater than or equal to 12%.

34. The non-woven article of claim 33, wherein the pigment is present in a fiber or filament.

35. The non-woven article of claim 34, wherein the fiber or filament comprises greater than or equal to 0.1 wt. % and less than or equal to 22 wt. % of the pigment.

36. The non-woven article of claim 33, wherein the non-woven article has a blackness My that is greater than or equal to 125 and less than or equal to 300.

37. The non-woven article of claim 33, wherein the non-woven article has a reflectivity in the visible spectrum of electromagnetic radiation that is less than or equal to 10.0%, and a reflectivity in the near-IR and LiDAR spectrum of electromagnetic radiation that is greater than or equal to 12%.

38. The non-woven article of claim 34, wherein a portion of the non-woven article comprises the fiber or filament with the pigment.

39. The non-woven article of claim 38, wherein the portion of the non-woven article has a blackness My that is greater than or equal to 125 and less than or equal to 300.

40. The non-woven article of claim 38, wherein portion of the non-woven article has a reflectivity in the visible spectrum of electromagnetic radiation that is less than or equal to 10.0%, and a reflectivity in the near-IR and LiDAR spectrum of electromagnetic radiation that is greater than or equal to 12%.

41. The non-woven article of claim 38, wherein in the portion of the paper article is a unique design.

42. The non-woven article of claim 41, wherein the unique design is a glyph, bar code, or QR code, or decorative image.

43. The non-woven article of claim 33, wherein the pigment is copper oxide nano-crystallites.

44. The non-woven article of claim 33, wherein the copper oxide crystallites have an average particle size that is greater than or equal to 5 nm and less than or equal to 15 nm.

45. The non-woven article of claim 33, wherein the copper oxide crystallites have a ratio of (−111) / (111) greater than or equal to 0.5 and less than or equal to 1.5.

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