LIDAR Reflective Cloth

Abstract

A composite material comprising a black pigment and a textile material. This composite material has a reflectance of 12% or more with respect to near-infrared electromagnetic radiation having a wavelength of 800 nm to 2500 nm, and a reflectance of 10% or less with respect to visible light having a wavelength of 350 nm to 750 nm. This composite material also has a blackness degree (My) of 125 to 165.

Description

Technical Field

[0001] This specification generally relates to particles that reflect near-infrared electromagnetic radiation, and more specifically to copper oxide particles integrated with a textile material that reflects near-infrared electromagnetic radiation.

Background Art

[0002] Both light detecting and ranging (LiDAR) systems that use pulsed laser electromagnetic radiation having a wavelength of 905 nanometers (nm) or 1050 nm, both in the near-infrared (“near-IR”) portion of the electromagnetic spectrum, have been proposed and tested for autonomous vehicle obstacle detection and avoidance systems. Reflection of near-IR electromagnetic radiation aids in the use of LiDAR, but dark-colored (e.g., black) articles, such as fabrics, not only absorb visible electromagnetic radiation to result in a dark color, but also absorb near-IR electromagnetic radiation having wavelengths greater than about 750 nanometers. Thus, LiDAR-based obstacle detection and avoidance systems may function poorly with respect to dark-colored articles.

Summary of the Invention

[0003] Accordingly, there is a need for alternative dark-colored articles that absorb electromagnetic radiation in the visible spectrum but reflect near-IR electromagnetic radiation having a wavelength of approximately 905 nm or 1050 nm.

[0004] A first aspect is a composite material comprising a black pigment and a textile material, the composite material having a reflectivity of 12% or more with respect to near-infrared electromagnetic radiation having a wavelength of 800 nm to 2500 nm, the composite material having a reflectivity of 10% or less with respect to visible light having a wavelength of 350 nm to 750 nm, the composite material having a blackness (M y ) of 125 to 165, the composite material being included.

[0005] A second aspect includes the composite material of the first aspect, wherein the black pigment comprises a compound selected from the group consisting of CuO, TiO2, and combinations of two or more thereof.

[0006] The third aspect includes a composite material according to any one of the first or second aspects, wherein the composite material has a reflectance of 5% or less with respect to visible light having a wavelength of 350 nm to 750 nm.

[0007] The fourth aspect includes a composite material according to any one of the first to third aspects, wherein the composite material has a reflectance of 1% or less with respect to visible light having a wavelength of 350 nm to 750 nm.

[0008] The fifth aspect includes a composite material according to any one of the first to fourth aspects, wherein the composite material has a reflectance of 15% or more with respect to near-infrared electromagnetic radiation having a wavelength of 800 nm to 2500 nm.

[0009] The sixth aspect includes a composite material according to any one of the first to fifth aspects, wherein the composite material has a reflectance of 20% or more with respect to near-infrared electromagnetic radiation having a wavelength of 800 nm to 2500 nm.

[0010] The seventh aspect includes a composite material according to any one of the first to sixth aspects, wherein the composite material has a blackness (M y ) of 130 to 165.

[0011] The eighth aspect includes a composite material according to any one of the first to seventh aspects, wherein the black pigment is CuO having an average particle size of 5 microns or less.

[0012] The ninth aspect includes a composite material according to any one of the first to eighth aspects, wherein the textile material is a synthetic polymer composition.

[0013] The tenth aspect includes a composite material according to any one of the first to ninth aspects, wherein the textile material is selected from the group consisting of polyamide, polyacrylonitrile, polyethylene terephthalate (PET), polybutyrate, polyurethane, nylon, polyester, and combinations of two or more thereof.

[0014] The eleventh aspect is such that the composite material has an L in the CIELAB color space* comprising any one of the composite materials of the first to tenth aspects, having a color with a lightness of 40 or less in * .

[0015] The twelfth aspect comprises any one of the composite materials of the first to eleventh aspects, having a color with a lightness of 10 or less in the L of the CIELAB color space. * comprising any one of the composite materials of the first to eleventh aspects, having a color with a lightness of 10 or less in * .

[0016] The thirteenth aspect comprises any one of the composite materials of the first to twelfth aspects, having a color with a lightness of 1 or less in the L of the CIELAB color space. * comprising any one of the composite materials of the first to twelfth aspects, having a color with a lightness of 1 or less in * .

[0017] The fourteenth aspect is a composite material comprising CuO and a textile material, wherein CuO has an average particle size of 5 microns or less, and the composite material has a color with a lightness of 40 or less in the L of the CIELAB color space. * comprising the composite material.

[0018] The fifteenth aspect comprises the composite material of the fourteenth aspect, wherein the textile material is selected from the group consisting of polyamide, polyacrylonitrile, polyethylene terephthalate (PET), polybutyrate, polyurethane, nylon, polyester, and combinations of two or more thereof.

[0019] The sixteenth aspect comprises any one of the composite materials of the fourteenth or fifteenth aspects, having a color with a lightness of 10 or less in the L of the CIELAB color space. * comprising any one of the composite materials of the fourteenth or fifteenth aspects, having a color with a lightness of 10 or less in * .

[0020] The seventeenth aspect comprises any one of the composite materials of the fourteenth to sixteenth aspects, having a reflectivity of 12% or more with respect to near-infrared electromagnetic radiation having a wavelength of 800 nm to 2500 nm.

[0021] The eighteenth aspect comprises any one of the composite materials of the fourteenth to seventeenth aspects, having a reflectivity of 10% or less with respect to visible light having a wavelength of 350 nm to 750 nm.

[0022] The 19th aspect includes a composite material having a blackness degree (M y ) of 125 to 165, and includes any one of the composite materials of the 14th to 18th aspects.

[0023] The 20th aspect is a method for manufacturing a black pigment-doped textile material, which includes combining a black pigment with a textile material to form a black pigment-doped textile material. The black pigment-doped textile material has a reflectance of 12% or more with respect to near-infrared electromagnetic radiation having a wavelength of 800 nm to 2500 nm, and the black pigment-doped textile material has a reflectance of 10% or less with respect to visible light having a wavelength of 350 nm to 750 nm. The black pigment-doped textile material has a blackness degree (M y ) of 125 to 165.

[0024] The 21st aspect includes the method of the 20th aspect, further including extruding the black pigment-doped textile material to thereby produce composite material fibers.

[0025] The 22nd aspect includes any one of the methods of the 20th or 21st aspects, wherein extruding includes heating the black pigment-doped textile material mixture to the softening point of the textile material and stretching the black pigment-doped textile material mixture through a die.

[0026] The 23rd aspect includes any one of the methods of the 20th to 22nd aspects, wherein extruding includes heating the black pigment-doped textile material mixture to the melting point of the textile material and stretching the black pigment-doped textile material mixture through a die.

[0027] The 24th aspect includes any one of the methods of the 20th to 23rd aspects, wherein extruding includes stretching the black pigment-doped textile material mixture through a spinneret to thereby produce filaments of the composite material fibers.

[0028] Aspect 25 includes any one of the methods of Aspects 20 to 24, wherein the black pigment is CuO having an average particle size of 5 microns or less.

[0029] Aspect 26 includes any one of the methods of Aspects 21 to 25, wherein the composite material fiber has a lightness L of 40 or less in the CIELAB color space * and has a color of.

[0030] Aspect 27 includes a fabric including any one of the composite materials of Aspects 1 to 13.

[0031] Aspect 28 includes the fabric of Aspect 27, wherein the black pigment is CuO having an average particle size of 5 microns or less.

[0032] These features and additional features provided by the embodiments described in the present disclosure will be more fully understood by considering the following detailed description in conjunction with the drawings.

[0033] The embodiments described in the drawings are essentially exemplary and representative and are not intended to limit the subject matter defined by the claims. The following detailed description of the exemplary embodiments can be understood by reading in conjunction with the following drawings in which similar structures are indicated by similar reference numerals.

Brief Description of the Drawings

[0034]

Figure 1A

[0035]

Figure 1B

[0036]

Figure 2

[0037]

Figure 3

[0038]

Figure 4A

[0039]

Figure 4B

[0040]

Figure 5A

[0041]

Figure 5B

DETAILED DESCRIPTION OF THE INVENTION

[0042] The embodiments disclosed herein are directed to LiDAR-reflective dark fabrics. Such LiDAR-reflective fabrics can be formed from fibers made of a textile polymer doped with a black pigment. The LiDAR-reflective dark fabric has a reflectance of 12% or more for near-infrared electromagnetic radiation having a wavelength of 800 nm to 2500 nm and a reflectance of 10% or less for visible light having a wavelength of 350 nm to 750 nm.

[0043] As used herein, the term "doped" means adding a small amount of a substance (e.g., a black pigment, which is referred to herein as a "dopant") to another material (e.g., a fiber made from a textile polymer). In this context, the term "small amount" refers to a maximum of 5% by mass of the dopant.

[0044] As used herein, the term "near-IR (near-infrared) electromagnetic radiation" refers to electromagnetic radiation having a wavelength in the range of 800 nm to 2500 nm, and "LiDAR" refers to electromagnetic radiation having a wavelength in the range of 905 nm to 1550 nm.

[0045] As used herein, the term "visible spectrum" or "visible light" refers to electromagnetic radiation having a wavelength in the range of 350 nm to 750 nm.

[0046] As used herein, the term "blackness" or "M" y " refers to an experimentally determined property of a material related to the ability of the material to absorb light. The blackness of a painted sample was evaluated using an X-Rite Ci7600 benchtop spectrophotometer (X-Rite, USA) based on a provided control standard (i.e., carbon black). This is based on the known formula shown below, where My is measured under D65 / 10° conditions.

[0047]

Equation

[0048] As used herein, the term "reflectivity" refers to a property of a material related to the ability of the material to reflect electromagnetic radiation. Reflectivity is quantitatively measured from a calibrated analysis of reflection data collected using an ultraviolet (UV) visible light spectrophotometer.

[0049] As used herein, the term "particle size" refers to the value of at least one dimension of a particle, or when referring to a sample of two or more particles, refers to the average value of at least one dimension across the sample population of particles. Particle size is measured by scanning electron microscopy and transmission electron microscopy.

[0050] As used herein, the term "CIELAB color space" is a color-opponent space having dimension L for lightness, based on the XYZ color space coordinates of the non-linearly compressed CIE space * , as well as a for the color-opponent dimension * and b * . The a * axis is perpendicular to the b * axis, forms the chromaticity plane, and the L * axis is perpendicular to the chromaticity plane, and the L * axis, in combination with the a * and b * axes, provides a complete description of the color attributes of an object, such as purity, hue, and lightness. Put simply, a very vivid stimulus (color) appears vivid and strong to the human eye, while a less vivid stimulus is more blurred and appears closer to gray. When there is no "vividness" at all, the color is the "achromatic" gray, and an image without vividness is typically called a grayscale (black and white) image or a monochrome image.

[0051] One difficulty in forming a dark-colored (e.g., black) article that reflects LiDAR or near-IR electromagnetic radiation is that the visible spectrum of the electromagnetic radiation is in close proximity to the near-IR electromagnetic radiation or LiDAR. Materials that result in a dark color, such as black, do not reflect electromagnetic radiation within the visible spectrum of the electromagnetic radiation. Also, such materials generally do not reflect electromagnetic radiation just outside the visible spectrum of electromagnetic radiation such as near-IR and LiDAR. Carbon black is one such material that is commonly used as a dark pigment, does not reflect electromagnetic radiation within the visible spectrum, and also does not reflect near-IR or LiDAR electromagnetic radiation. Thus, a material that does not reflect electromagnetic radiation within the visible spectrum but reflects near-IR or LiDAR electromagnetic radiation requires a very sharp increase in reflectivity just outside the visible spectrum of the electromagnetic radiation.

[0052] Figure 1A shows the reflectance of materials commonly used as colorants in various articles. The percentage of ideal reflectance is shown along the y-axis of Figure 1A, and the wavelength of electromagnetic radiation is shown along the x-axis of Figure 1A. The reflectance of conventional black colorants such as carbon black is shown along the lower part of the graph. As shown in Figure 1A, the carbon black colorant does not reflect electromagnetic radiation in the visible spectrum (up to the left side of the graph). That is, the reflectance of this black colorant is approximately 0% (percent) within the visible spectrum of electromagnetic radiation. This indicates that the colorant results in a dark, nearly pure black. However, this conventional colorant also reflects approximately 0% of the electromagnetic radiation outside the visible spectrum, such as near-IR electromagnetic radiation or LiDAR electromagnetic radiation (e.g., greater than about 750 nanometers (nm) to about 1550 nm) (up to the right side of the graph). Similarly, near the top of the graph, the reflectance of white TiO2, which is used as a conventional white colorant, is shown. As shown in Figure 1A, white TiO2 reflects near-IR and LiDAR electromagnetic radiation (e.g., from greater than about 750 nm to 1550 nm) as shown on the right side of the graph, and the reflectance of near-IR and LiDAR electromagnetic radiation is greater than 40% (at 1550 nm) and approximately 60% (at 905 nm). However, white TiO2 also reflects electromagnetic radiation within the visible spectrum, as its name indicates. As shown in Figure 1A, white TiO2 reflects nearly 80% of the electromagnetic radiation within the visible spectrum. Therefore, neither of these colorants, carbon black or white TiO2, is suitable as a dark particle that also reflects near-infrared or LiDAR electromagnetic radiation.

[0053] Figure 1B is a graph showing the target conditions of particles that do not reflect light within the visible spectrum of electromagnetic radiation but reflect near-IR and LiDAR electromagnetic radiation. In Figure 1B, the percentage of reflectance is measured along the y-axis, and the wavelength of the electromagnetic radiation is shown along the x-axis. Along the bottom of the graph, the reflectance of a conventional black colorant is shown, which is the same as the reflectance of the conventional black colorant (e.g., carbon black) shown in Figure 1A. As shown in Figure 1B, particles that do not reflect electromagnetic radiation within the visible spectrum but reflect near-IR and LiDAR electromagnetic radiation have at least two distinct reflection regions. The first reflection region is within the visible spectrum of the electromagnetic radiation and is shown on the left side of the graph in Figure 1B. In this reflection region, particles that do not reflect electromagnetic radiation within the visible spectrum but reflect near-IR and LiDAR electromagnetic radiation behave similarly to a conventional black colorant (e.g., carbon black, in contrast to white TiO2) by not reflecting electromagnetic radiation within the visible spectrum. As shown in Figure 1B, particles that do not reflect electromagnetic radiation within the visible spectrum but reflect near-IR and LiDAR electromagnetic radiation. However, particles that do not reflect electromagnetic radiation within the visible spectrum but reflect near-IR and LiDAR electromagnetic radiation have a second reflection region outside the visible spectrum of the electromagnetic radiation.

[0054] The second reflective region encompasses electromagnetic radiation having wavelengths from 750 nm to 1550 nm (including near-IR and LiDAR electromagnetic radiation). In the second reflective region, particles that do not reflect electromagnetic radiation within the visible spectrum but reflect near-IR and LiDAR electromagnetic radiation function similarly to white TiO2 (in contrast to carbon black) by reflecting a large amount of electromagnetic radiation within the second reflective region. As shown in Figure 1B, particles that do not reflect electromagnetic radiation within the visible spectrum but reflect near-IR and LiDAR electromagnetic radiation reflect, for example, approximately 60% of LiDAR electromagnetic radiation having a wavelength of 905 nm and more than 40% of LiDAR electromagnetic radiation having a wavelength of 1550 nm. By having a reflectivity in the second reflective region similar to that of white TiO2, the particles can reflect a sufficient amount of near-IR and LiDAR electromagnetic radiation such that the particles can be detected by a LiDAR system.

[0055] Figure 1B shows the difficulty in forming particles that do not reflect electromagnetic radiation within the visible spectrum but reflect near-IR and LiDAR electromagnetic radiation. In particular, Figure 1B shows a sharp increase in reflectivity just outside the visible spectrum of electromagnetic radiation. In multiple embodiments, this sharp increase in reflectivity occurs at the wavelength of electromagnetic radiation of 905 nm or near it, which is a wavelength of electromagnetic radiation commonly used in LiDAR systems. As shown in Figure 1B, the reflectivity increases from approximately 0% to nearly 60% at the wavelength of electromagnetic radiation that is approximately 905 nm. It is difficult to achieve the formation of particles that exhibit such an accurate and sharp increase in reflectivity, and there is very little room for error. For example, if the material reflects too much electromagnetic radiation within the visible spectrum, the color appearance is not pure black but has, for example, a slight red or purple tint. However, if the material does not reflect a sufficient amount of near-IR or LiDAR electromagnetic radiation either, the material is not suitable for detection by a LiDAR system.

[0056] Some materials do not reflect electromagnetic radiation within most of the visible spectrum but reflect near-IR and LiDAR electromagnetic radiation. However, these materials were unable to reproduce the visible appearance of carbon black (i.e., having a reflectivity of approximately 0% for electromagnetic radiation within the visible spectrum).

[0057] One way to determine this transition from low reflectivity in the visible spectrum of electromagnetic radiation to high reflectivity in near-IR and LiDAR electromagnetic radiation is by evaluating the bandgap of the material. The bandgap 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 orbits where electrons can jump out and move to the CB when excited. The VB is the outermost shell electron orbits of an atom that electrons can actually occupy. The bandgap is the energy required for an electron to move from the VB to the CB and can be an indicator of the conductivity of the material. In optics, the bandgap correlates with the threshold at which photons can be absorbed by the material. Thus, the bandgap determines the portion of the electromagnetic spectrum that the material can absorb. Generally, materials with a large bandgap absorb most of the electromagnetic spectrum with short wavelengths, and materials with a small bandgap absorb most of the electromagnetic spectrum with long wavelengths. In other words, a large bandgap means that a lot of energy is required to excite valence electrons to the CB. In contrast, when the valence band and the conduction band overlap as in the case of a metal, electrons can easily jump across the two bands, which means the material is highly conductive. However, it has been found that by manipulating the bandgap of a material, the type of electromagnetic spectrum absorbed by the material can be controlled. Considering this, materials with a bandgap energy close to the LiDAR detection electromagnetic radiation wavelength (approximately 905 nm) or a bandgap of approximately 1.37 eV and a sharp transition at the visible end (approximately 700 nm) are promising candidates.

[0058] In multiple embodiments, the black pigment may include chromium iron oxide and its derivatives. Chromium iron oxide materials can generally reflect near-IR and LiDAR electromagnetic radiation, but colorants made from chromium iron oxide or its derivatives have a slight red or blue in them, so colorants made from chromium iron oxide materials are generally called "cool black". FIG. 2 is a bar graph showing the blackness of various materials on the y-axis. The blackness is measured by an X-Rite spectrophotometer. At the left end of FIG. 2 is carbon black, which is a material commonly used as a black colorant, but carbon black does not reflect near-IR or LiDAR electromagnetic radiation either. 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 shown in FIG. 2, these materials have a blackness of approximately 142 or less. Since Materials 1-7 have a red or blue tint, this difference in blackness is significant. Thus, this fairly large gap in blackness between carbon black and Materials 1-7 indicates that Materials 1-7 are not suitable for use in applications where pure black is desired, such as paints for automotive applications or black fabrics.

[0059] In multiple embodiments, the black pigment comprises copper(II) oxide or cupric oxide (CuO). CuO is a common inorganic compound that is a black solid substance in its natural state. However, not all copper oxides have this black color. That is, another stable oxide of copper is cuprous oxide (Cu2O), which is a red solid in its natural state. Without being bound to a particular theory, the oxidation state of copper atoms is thought to be one factor in the color of the compound. CuO is a product of copper mining and a precursor for many other copper-containing products and compounds. CuO has been used as a black pigment in certain applications such as ceramics, glazes, etc. However, CuO does not reflect near-IR or LiDAR electromagnetic radiation. That is, in its natural state, CuO does not reflect electromagnetic radiation in the visible spectrum and also does not reflect electromagnetic radiation in the near-IR or LiDAR spectrum, behaving much like carbon black in this regard. Without being bound to any particular theory, CuO has a bandgap of 2.0 eV and does not easily reflect electromagnetic radiation in the near-IR or LiDAR spectrum. Manipulating CuO to have a bandgap that is more reflective of electromagnetic radiation in the near-IR or LiDAR spectrum causes the color of CuO to fade to a brownish-black.

[0060] As described above, articles containing carbon black exhibit a very low reflectivity (less than 1%) across the visible and near-IR wavelengths, resulting in a high blackness value M y Paint using commercially available CuO shows selectively higher near-IR reflectivity between the wavelengths of electromagnetic radiation from 900 nm to 1000 nm, but CuO shows distinguishable reflection in the visible wavelength, especially in the red hue, resulting in an apparent brownish color tone with a blackness value M y of less than 130. On the other hand, “Cool Black” shows strong reflection at the short-wavelength end of the near-IR spectrum at electromagnetic radiation wavelengths exceeding 905 nm, but does not absorb sufficiently at visible wavelengths and has a blackness value M y of 125.

[0061] Generally, compounds that absorb electromagnetic radiation in the visible spectrum (i.e., do not reflect it) and reflect electromagnetic radiation in the near-IR and LiDAR spectra require a bandgap of 1.2 eV to 1.8 eV. Without manipulation, bulk CuO does not meet these requirements. Bulk CuO has a reported bandgap of 2.0 eV and a blackness M y of 120. This bandgap is outside the range of 1.2 eV to 1.8 eV required to reflect electromagnetic radiation in the near-IR and LiDAR spectra. Further, as described above in connection with FIG. 2, a blackness M y of 120 is significantly lower than the blackness M y of carbon black. Thus, in the embodiments disclosed and described herein, the CuO crystallites (microcrystals) have a significantly small particle size, thereby resulting in a decrease in the bandgap and an increase in the blackness M y of CuO.

[0062] Without being bound by any particular theory, the sharp transition in reflectivity (or absorbance) between electromagnetic radiation of wavelength 700 nm and electromagnetic radiation of wavelength 905 nm may be attributed to a ratio of approximately 1 of the (-111) / (111) crystal planes and a crystal size of approximately 100 Å for the (-111) plane. Such particles appear indistinguishable from carbon black and have the same measured blackness, but these particles exhibit a 1500% better detectability by LiDAR than carbon black.

[0063] Examples of methods for manufacturing CuO nanoparticles include mechanical methods such as ball milling, jet milling, or a combination of the two. In multiple embodiments, the CuO nanoparticles may be formed according to the procedure disclosed in U.S. Provisional Application No. 63 / 208783, entitled "Materials with High LiDAR Reflectivity," the entire contents of which are incorporated herein by reference. Briefly, the method includes combining a precipitating agent with a solution containing copper nitrate to form a precipitate, drying the filtered precipitate to obtain a dry precipitate, and sintering the dry precipitate to form copper oxide crystallites having an average particle size of 5 nm or more and 15 nm or less. The precipitating agent is selected from the group consisting of sodium hydroxide, sodium carbonate, ammonium carbonate, and combinations of two or more thereof.

[0064] In multiple embodiments, CuO crystallites that can be used as an alternative to carbon black, exhibit excellent blackness in the visible spectrum of electromagnetic radiation, and also have high reflectivity at near-IR and LiDAR electromagnetic radiation wavelengths can be synthesized by a scalable precipitation-thermal decomposition method (appropriately selecting the precipitating agent within a specific concentration range), followed by a well-defined sintering process. From tests of the structural and chemical composition, the development from the precursor to the extracted precipitate and to the final CuO crystallites at various process stages can be understood. As referred to above, two important indicators in the XRD spectrum can be used to guide the experimental conditions towards the desired crystal structure and the resulting optical contrast in both the visible and near-IR ranges.

[0065] In multiple embodiments, the CuO crystallites can have an average particle size of 5.0 μm or less, for example, 4.5 μm or less, 4.0 μm or less, 3.5 μm or less, 3.0 μm or less, 2.5 μm or less, 2.0 μm or less, 1.5 μm or less, 1.0 μm or less, or 0.5 μm or less. In such embodiments, the CuO crystallites can have an average particle size of 0.5 μm to 5.0 μm, for example, 1.0 μm to 5.0 μm, 1.5 μm to 5.0 μm, 2.0 μm to 5.0 μm, 2.5 μm to 5.0 μm, 3.0 μm to 5.0 μm, 3.5 μm to 5.0 μm, 4.0 μm to 5.0 μm, 4.5 μm to 5.0 μm, 0.5 μm to 4.5 μm, 1.0 μm to 4.5 μm, 1.5 μm to 4.5 μm, 2.0 μm to 4.5 μm, 2.5 μm to 4.5 μm, 3.0 μm to 4.5 μm, 3.5 μm to 4.5 μm, 4.0 μm to 4.5 μm, 0.5 μm to 4.0 μm, 1.0 μm to 4.0 μm, 1.5 μm to 4.0 μm, 2.0 μm to 4.0 μm, 2.5 μm to 4.0 μm, 3.0 μm to 4.0 μm, 3.5 μm to 4.0 μm, 0.5 μm to 3.5 μm, 1.0 μm to 3.5 μm, 1.5 μm to 3.5 μm, 2.0 μm to 3.5 μm, 2.5 μm to 3.5 μm, 3.0 μm to 3.5 μm, 0.5 μm to 3.0 μm, 1.0 μm to 3.0 μm, 1.5 μm to 3.0 μm, 2.0 μm to 3.0 μm, 2.5 μm to 3.0 μm, 0.5 μm to 2.5 μm, 1.0 μm to 2.5 μm, 1.5 μm to 2.5 μm, 2.0 μm to 2.5 μm, 0.5 μm to 2.0 μm, 1.0 μm to 2.0 μm, 1.5 μm to 2.0 μm, 0.5 μm to 1.5 μm, 1.0 μm to 1.5 μm, or 0.5 μm to 1.0 μm.

[0066] In one or more embodiments, the CuO crystallites can have an average particle size of 50 nm or less, 45 nm or less, 40 nm or less, 35 nm or less, 30 nm or less, 25 nm or less, 20 nm or less, 15 nm or less, or 10 nm or less. For example, the CuO crystallites can have an average particle size of 5 nm to 15 nm, such as 6 nm to 15 nm, 7 nm to 15 nm, 8 nm to 15 nm, 9 nm to 15 nm, 10 nm to 15 nm, 11 nm to 15 nm, 12 nm to 15 nm, 13 nm to 15 nm, 14 nm to 15 nm, 5 nm to 14 nm, 6 nm to 14 nm, 7 nm to 14 nm, 8 nm to 14 nm, 9 nm to 14 nm, 10 nm to 14 nm, 11 nm to 14 nm, 12 nm to 14 nm, 13 nm to 14 nm, 5 nm to 13 nm, 6 nm to 13 nm, 7 nm to 13 nm, 8 nm to 13 nm, 9 nm to 13 nm, 10 nm to 13 nm, 11 nm to 13 nm, 12 nm to 13 nm, 5 nm to 12 nm, 6 nm to 12 nm, 7 nm to 12 nm, 8 nm to 12 nm, 9 nm to 12 nm, 10 nm to 12 nm, 11 nm to 12 nm, 5 nm to 11 nm, 6 nm to 11 nm, 7 nm to 11 nm, 8 nm to 11 nm, 9 nm to 11 nm, 10 nm to 11 nm, 5 nm to 10 nm, 6 nm to 10 nm, 7 nm to 10 nm, 8 nm to 10 nm, 9 nm to 10 nm, 5 nm to 9 nm, 6 nm to 9 nm, 7 nm to 9 nm, 8 nm to 9 nm, 5 nm to 8 nm, 6 nm to 8 nm, 7 nm to 8 nm, 5 nm to 7 nm, 6 nm to 7 nm, or 5 nm to 6 nm.

[0067] Although not bound by a particular theory, it is believed that as the average crystal size of the CuO nanoparticles decreases, the bandgap of the CuO nanoparticles decreases. Thus, by reducing bulk CuO particles to CuO nanoparticles according to the embodiments disclosed and described herein, the bandgap of the CuO nanoparticles falls within the range of reflecting electromagnetic radiation within the near-IR and LiDAR spectra. In a plurality of embodiments, the bandgap of the CuO nanoparticles as measured by X-ray photoelectron spectroscopy (XPS) is from 1.2 eV to 1.8 eV, such as from 1.3 eV to 1.8 eV, from 1.4 eV to 1.8 eV, from 1.5 eV to 1.8 eV, from 1.6 eV to 1.8 eV, from 1.7 eV to 1.8 eV, from 1.2 eV to 1.7 eV, such as from 1.3 eV to 1.7 eV, from 1.4 eV to 1.7 eV, from 1.5 eV to 1.7 eV, from 1.6 eV to 1.7 eV, from 1.2 eV to 1.6 eV, such as from 1.3 eV to 1.6 eV, from 1.4 eV to 1.6 eV, from 1.5 eV to 1.6 eV, from 1.2 eV to 1.5 eV, such as from 1.3 eV to 1.5 eV, from 1.4 eV to 1.5 eV, from 1.2 eV to 1.4 eV, such as from 1.3 eV to 1.4 eV, or from 1.2 eV to 1.3 eV.

[0068] In some embodiments, the black pigment may include a dark pigment disclosed in U.S. Patent No. 11,118,062, the entire content of which is incorporated herein by reference. Briefly, the dark pigment includes a core layer formed from a reflective 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 may have a thickness of 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 may have a thickness of 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 having a thickness of about 5 nm to about 500 nm. This pigment reflects less than 10% of the incident visible electromagnetic radiation at all angles of incidence from 0° to 45° of visible electromagnetic radiation. This pigment reflects more than 60% of the incident near-IR electromagnetic radiation having a wavelength of 850 nm to 950 nm at all angles of incidence from 0° to 45° of near-IR electromagnetic radiation.

[0069] In some embodiments, the black pigment may be black TiO2 as 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 comparable to that of carbon black. Further, black TiO2 generally does not exhibit red and brown hues and is a good alternative to carbon black. However, standard black TiO2 does not reflect near-IR or LiDAR electromagnetic radiation. Further, TiO2 is white in its natural state and must be treated, for example, by hydrogenation, etc. to form black TiO2, and black TiO2 is more expensive to prepare than carbon black. White TiO2 reflects near-IR and LiDAR electromagnetic radiation, but when processed into black TiO2, it loses its ability to reflect near-IR and LiDAR electromagnetic radiation. Thus, black TiO2 is visually similar to carbon black with respect to its blackness, but carbon black is generally preferred over black TiO2 for these and economic reasons. However, white TiO2 may be converted to black TiO2 that does not reflect electromagnetic radiation in the visible spectrum but reflects near-IR and LiDAR electromagnetic radiation. In some embodiments, black TiO2 has a crystalline titanium dioxide core and an amorphous titanium dioxide shell surrounding the crystalline titanium dioxide core.

[0070] Regardless of which pigment is included in the composite material, the blackness M of the black pigment y(That is, the blackness scale) is, in a plurality of embodiments, 125 to 170, for example, 130 to 170, 135 to 170, 140 to 170, 145 to 170, 150 to 170, 155 to 170, 160 to 170, 165 to 170, 125 to 165, 130 to 165, 135 to 165, 140 to 165, 145 to 165, 150 to 165, 155 to 165, 160 to 165, 125 to 160, 130 to 160, 135 to 160, 140 to 160, 145 to 160, 150 to 160, 155 to 160, 125 to 155, 130 to 155, 135 to 155, 140 to 155, 145 to 155, 150 to 155, 125 to 150, 130 to 150, 135 to 150, 140 to 150, 145 to 150, 125 to 145, 130 to 145, 135 to 145, 140 to 145, 125 to 140, 130 to 140, 135 to 140, 125 to 135, 130 to 135, or 125 to 130.

[0071] In a plurality of embodiments, the black pigment may have a reflectance of 10% or less, for example, 9% or less, 8% or less, 7% or less, 6% or less, 5% or less, 4% or less, 3% or less, 2% or less, 1% or less, or 0.5% or less in the visible spectrum (350 nm to 750 nm) of electromagnetic radiation.

[0072] In a plurality of embodiments, the black pigment may have a reflectance of 10% or more, for example, 15% or more, 20% or more, 25% or more, 30% or more, or 35% or more, 40% or more, 45% or more, 50% or more, 55% or more, or 60% or more in the near IR and LiDAR spectra (800 nm to 2500 nm) of electromagnetic radiation.

[0073] The textile material of the composite material is not particularly limited and can refer to any polymer material used to form synthetic fibers. Exemplary textile materials include, but are not limited to, polyamide, polyacrylonitrile, polyethylene terephthalate (PET), polybutyrate, polyurethane, nylon, polyester, and combinations of two or more thereof.

[0074] In multiple embodiments, the fibers made from the textile polymer contain 0.1% to 5.0% by mass of a black pigment, such as 0.5% to 5.0% by mass of a black pigment, 1.0% to 5.0% by mass of a black pigment, 1.5% to 5.0% by mass of a black pigment, 2.0% to 5.0% by mass of a black pigment, 2.5% to 5.0% by mass of a black pigment, 3.0% to 5.0% by mass of a black pigment, 3.5% to 5.0% by mass of a black pigment, 4.0% to 5.0% by mass of a black pigment, 4.5% to 5.0% by mass of a black pigment, 0.1% to 4.5% by mass of a black pigment, 0.5% to 4.5% by mass of a black pigment, 1.0% to 4.5% by mass of a black pigment, 1.5% to 4.5% by mass of a black pigment, 2.0% to 4.5% by mass of a black pigment, 2.5% to 4.5% by mass of a black pigment, 3.0% to 4.5% by mass of a black pigment, 3.5% to 4.5% by mass of a black pigment, 4.0% to 4.5% by mass of a black pigment, 0.1% to 4.0% by mass of a black pigment, 0.5% to 4.0% by mass of a black pigment, 1.0% to 4.0% by mass of a black pigment, 1.5% to 4.0% by mass of a black pigment, 2.0% to 4.0% by mass of a black pigment, 2.5% to 4.0% by mass of a black pigment, 3.0% to 4.0% by mass of a black pigment, 3.5% to 4.0% by mass of a black pigment, 0.1% to 3.5% by mass of a black pigment, 0.5% to 3.5% by mass of a black pigment, 1.0% to 3.5% by mass of a black pigment, 1.5% to 3.5% by mass of a black pigment, 2.0% to 3.5% by mass of a black pigment, 2.5% to 3.5% by mass of a black pigment, 3.0% to 3.5% by mass of a black pigment, 0.1% to 3.0% by mass of a black pigment, 0.5% to 3.0% by mass of a black pigment, 1.0% to 3.0% by mass of a black pigment, 1.5% to 3.0% by mass of a black pigment, 2.0% to 3.0% by mass of a black pigment, 2.5% to 3.0% by mass of a black pigment, 0.1% to 2.5% by mass of a black pigment, 0.5% to 2.5% by mass of a black pigment, 1.0% to 2.5% by mass of a black pigment, 1.5% to 2.5% by mass of a black pigment, 2.0% to 2.5% by mass of a black pigment, 0.1% to 2.0% by mass of a black pigment, 0.5% to 2.0% by mass of a black pigment, 1.0% to 2.0% by mass of a black pigment, 1.It may be doped with a black pigment of 5% by mass to 2.0% by mass, a black pigment of 0.1% by mass to 1.5% by mass, a black pigment of 0.5% by mass to 1.5% by mass, a black pigment of 1.0% by mass to 1.5% by mass, a black pigment of 0.1% by mass to 1.0% by mass, a black pigment of 0.5% by mass to 1.0% by mass, or a black pigment of 0.1% by mass to 0.5% by mass.

[0075] In some embodiments, the composite material has an L value in the CIELAB color space * and may have a color with a lightness of 40 or less, 35 or less, 30 or less, 25 or less, 20 or less, 15 or less, 10 or less, 9 or less, 8 or less, 7 or less, 6 or less, 5 or less, 4 or less, 3 or less, 2 or less, or 1 or less.

[0076] Regardless of which pigment is included in the composite material, the blackness M of the composite material y is, in a plurality of embodiments, 125 to 165, for example, 130 to 165, 135 to 165, 140 to 165, 145 to 165, 150 to 165, 155 to 165, 160 to 165, 125 to 160, 130 to 160, 135 to 160, 140 to 160, 145 to 160, 150 to 160, 155 to 160, 125 to 155, 130 to 155, 135 to 155, 140 to 155, 145 to 155, 150 to 155, 125 to 150, 130 to 150, 135 to 150, 140 to 150, 145 to 150, 125 to 145, 130 to 145, 135 to 145, 140 to 145, 125 to 140, 130 to 140, 135 to 140, 125 to 135, 130 to 135, or 125 to 130.

[0077] In a plurality of embodiments, the composite material may have a reflectance of 10% or less, for example, 9% or less, 8% or less, 7% or less, 6% or less, 5% or less, 4% or less, 3% or less, 2% or less, 1% or less, or 0.5% or less in the visible spectrum (350 nm to 750 nm) of electromagnetic radiation.

[0078] In multiple embodiments, the composite material can have a reflectivity of 12% or more, such as 15% or more, 20% or more, 25% or more, 30% or more, or 35% or more in the near-IR and LiDAR spectra (800 nm - 2500 nm) of electromagnetic radiation. In one or more embodiments, the composite material has a reflectivity of 12% or more and 30% or less, such as 15% or more and 30% or less, 20% or more and 30% or less, or 25% or more and 30% or less, 12% or more and 25% or less, 15% or more and 25% or less, 20% or more and 25% or less, 12% or more and 20% or less, 15% or more and 20% or less, or 12% or more and 15% or less in the near-IR and LiDAR spectra (800 nm - 2500 nm) of electromagnetic radiation.

[0079] It should be understood that in one or more embodiments, the composite material may include a mixture of LiDAR-reflective black pigments (such as CuO and black TiO2, etc.) and other commercially available black pigments (such as carbon black, etc.).

[0080] According to some embodiments, a method for manufacturing composite material fibers is disclosed. Any of the above black pigments can be combined with a textile material to form a black pigment-doped textile material mixture. In multiple embodiments, combining the black pigment with the textile material may include softening and / or melting the textile material and mixing the black pigment. In multiple embodiments, combining the black pigment with the textile material includes dispersing the black pigment in a solvent and immersing an already formed portion of the textile material. Exemplary solvents include water, methanol, ethanol, propanol, isopropanol, pentane, hexane, and heptane.

[0081] In embodiments where the textile material is softened and / or melted and then doped with a black pigment, the resulting black pigment-doped textile material mixture can then be extruded to produce composite material fibers. In a plurality of embodiments, extrusion may include heating the black pigment-doped textile material mixture to the softening point of the textile material and stretching the thus-softened black pigment-doped textile material mixture through a die. In a plurality of embodiments, extrusion may include heating the black pigment-doped textile material mixture to the melting point of the textile material and stretching the thus-melted black pigment-doped textile material mixture through a die. In a plurality of embodiments, extrusion may include stretching the black pigment-doped textile material mixture through a spinneret, thereby producing filaments of the composite material fibers.

[0082] In a plurality of embodiments, the composite material fibers may be used to produce yarns or threads that are woven, knitted, or sewn to form LiDAR-reflective black fabric. The LiDAR-reflective black fabric can be used in many applications. One exemplary use of the LiDAR-reflective black fabric is incorporation into workwear and uniforms for road construction, factory work, warehouse operations, or any other work environment where autonomous vehicles and other autonomous devices using LiDAR are employed. Another exemplary use of the LiDAR-reflective black fabric is incorporation into sportswear such as running apparel. Yet another example includes outdoor wear such as jackets, coats, parkas, ski pants, and snow suits. As autonomous vehicles become increasingly widespread throughout society, additional uses can be contemplated, such as for canopies or umbrellas for strollers, due to the increasing need for LiDAR-reflective fabric.

Examples

[0083] A plurality of embodiments will be further clarified by the following examples.

[0084] Example 1 - Synthesis

[0085] Copper(II) nitrate Cu(NO3)2, sodium hydroxide (NaOH), and sodium carbonate Na2CO3 of analytical grade (AR) obtained from Sigma Aldrich, as well as deionized water, were used without further purification.

[0086] CuO nanoparticles were synthesized by a coprecipitation method using Na2CO3 or NaOH as a precipitating agent. In a typical synthesis, the required amount of Cu(NO3)2 was dissolved in 300 mL of distilled water. A solution of Na2CO3 or NaOH of known concentration was added dropwise to the Cu(NO3)2 solution at room temperature with vigorous stirring. The solution was then stirred for 3 hours and aged overnight before filtration. After stirring overnight, the precipitate was filtered and washed with 1000 mL of distilled water. The solid product was then dried at 120 °C overnight and sintered at 300 °C to 600 °C for 3 hours at a heating rate of 5 °C / min.

[0087] The crystallographic information of the CuO nanoparticles was investigated using powder X-ray diffraction (XRD, Rigaku Miniflex 600, Japan) with Cu Kα radiation (λ = 0.1541 nm). The average crystallite size τ of the prepared particles was estimated from the measured widths of their XRD diffraction curves using the Scherrer equation (1).

Equation

[0088] The CuO nanoparticles were then combined with a polymer material, and the mixture was heated to at least the softening point of the polymer material and extruded to produce a filament for forming a composite fiber.

[0089] The composite fibers thus obtained were woven into a single piece of cloth of the composite fibers. The optical properties of the cloth were determined using a UV / Vis / NIR spectrophotometer (Cary 7000, Agilent, USA). The calculation of the band gap was based on the Kubelka-Munk function F(R ∞ ), which is related to the diffuse reflectance R ∞ of the sample by Equation (2).

Equation

[0090] The blackness M y of the cloth was evaluated using an X-Rite Ci7600 benchtop spectrophotometer (X-Rite, USA) and directly related to the standard provided by the instrument according to Equation (3).

Equation

[0091] Comparative Example 1

[0092] The reflectance of a commercially available black polyester (Instamorph Plastic manufactured by Sorfeo Inc.) was measured using an ultraviolet-visible spectrophotometer. Figure 3 is a graph showing the results of the reflectance at wavelengths of electromagnetic radiation in the range of approximately 250 nm to approximately 2500 nm. As shown in Figure 3, the reflectance at electromagnetic radiation wavelengths of 910 nm or more is less than 3%.

[0093] Example 2

[0094] Commercially available white polyester (Instamorph Plastic manufactured by Sorfeo Inc.) was doped by gradually increasing the mass percentage of the CuO nanoparticles synthesized according to Example 1 above. The polyester was heated to over 100 °C and then the CuO powder was mechanically mixed to perform doping of the polyester. Then, the doped polyester was allowed to cool and returned to room temperature. Specifically, seven samples were prepared, namely, a sample doped with 0.10 mass% of CuO nanoparticles, a sample doped with 0.20 mass% of CuO nanoparticles, a sample doped with 0.50 mass% of CuO nanoparticles, a sample doped with 1.00 mass% of CuO nanoparticles, a sample doped with 2.00 mass% of CuO nanoparticles, a sample doped with 3.00 mass% of CuO nanoparticles, and a sample doped with 5.00 mass% of CuO nanoparticles in white polyester.

[0095] Figure 4A is a graph showing the reflectance of these samples (and undoped commercially available white polyester) at electromagnetic radiation wavelengths in the range of about 250 nm to about 2500 nm. As shown in Figure 4A, in the case of doping with 0.10 mass% of CuO nanoparticles, the reflectance in the visible electromagnetic radiation spectrum of the doped polyester decreased to less than 20% (compared with about 40% in the case of undoped polyester), but the reflectance at electromagnetic radiation wavelengths of about 900 nm to about 1600 nm of the doped polyester was over 40%, and the reflectance at electromagnetic radiation wavelengths of about 1600 nm to about 2200 nm was close to 20%. Furthermore, in the case of doping with 0.20 mass% or more of CuO nanoparticles, the reflectance in the visible electromagnetic radiation spectrum of the doped polyester decreased to less than 10% (up to about 5%), but the reflectance at electromagnetic radiation wavelengths of about 900 nm to about 1600 nm of the doped polyester was from about 20% to over 40%, and the reflectance at electromagnetic radiation wavelengths of about 1600 nm to about 2200 nm exceeded 10% in many samples.

[0096] Figure 4B is a bar graph showing the reflectance of the sample at an electromagnetic radiation wavelength of 910 nm. As shown in Figure 4B, the reflectance is very high for the undoped polyester and the polyester doped with 0.10% by mass of CuO nanoparticles, and these samples reflect a significant amount of electromagnetic radiation wavelengths in the visible spectrum. However, the polyester samples doped with 0.20% by mass or more reflected more than 15% of the electromagnetic radiation at a wavelength of 900 nm and reflected a small amount of electromagnetic radiation wavelengths in the visible spectrum.

[0097] Example 3

[0098] Commercially available white polyester (Instamorph Plastic manufactured by Sorfeo Inc.) was doped with 0.5% by mass of the CuO nanoparticles synthesized according to Example 1 above. The polyester was heated to above 100 °C and then the CuO powder was mechanically mixed to dope the polyester. The polyester was then allowed to cool and return to room temperature. Carbon black (carbon black manufactured by Pearl Ex) was added to this polyester in increasing mass percentages. Specifically, five samples were prepared, namely, a sample doped with 0.20% by mass of carbon black in the polyester doped with 0.5% by mass of CuO nanoparticles, a sample doped with 0.40% by mass of carbon black, a sample doped with 0.60% by mass of carbon black, a sample doped with 0.80% by mass of carbon black, and a sample doped with 1.00% by mass of carbon black.

[0099] Figure 5A is a graph showing the reflectance of these samples (and a commercially available white polyester doped with 0.5 wt% CuO nanoparticles) at electromagnetic radiation wavelengths in the range of about 250 nm to about 2500 nm. As shown in Figure 5A, all samples had similar reflectance at electromagnetic radiation wavelengths within the visible spectrum, but the reflectance of the polyester at electromagnetic radiation wavelengths of about 900 nm to about 1600 nm decreased as carbon black was added to the polyester, and there was a significant decrease between 0.20 wt% doping and 0.40 wt% doping. Samples doped with more than 0.40 wt% carbon black had very similar reflectance at electromagnetic radiation wavelengths of about 900 nm to about 1600 nm.

[0100] Figure 5B is a bar graph showing the reflectance of the samples at an electromagnetic radiation wavelength of 910 nm. As shown in Figure 5B, the reflectance of the polyester doped with 0.5 wt% CuO nanoparticles and not doped with carbon black was very high. However, the reflectance at an electromagnetic radiation wavelength of 910 nm decreased as carbon black was added to the polyester. The reflectance at an electromagnetic radiation wavelength of 910 nm leveled off at less than 20% after filling with 0.6 wt% carbon black.

[0101] Although specific embodiments have been illustrated and described herein, it should be understood that various other changes and modifications can be made without departing from the spirit and scope of the claimed subject matter. Further, although various aspects of the claimed subject matter have been described herein, it is not necessary to use such aspects in combination. Accordingly, the appended claims are intended to encompass all such changes and modifications that are within the scope of the claimed subject matter.

Claims

1. A composite material comprising a black pigment and a textile material, wherein the composite material has a reflectance of 12% or more with respect to near-infrared electromagnetic radiation having a wavelength of 800 nm to 2500 nm, the composite material has a reflectance of 10% or less with respect to visible light having a wavelength of 350 nm to 750 nm, a composite material. The composite material has a blackness degree (M ｙ ) of 125 to 165

2.

3. The black pigment is a compound selected from the group consisting of CuO, TiO ２ , and combinations of two or more thereof, the composite material according to claim 1. The composite material according to claim 1, wherein the composite material has a reflectance of 5% or less with respect to visible light having a wavelength of 350 nm to 750 nm.

4. The composite material according to claim 1, wherein the composite material has a reflectance of 1% or less with respect to visible light having a wavelength of 350 nm to 750 nm.

5. The composite material according to claim 1, wherein the composite material has a reflectance of 15% or more with respect to near-infrared electromagnetic radiation having a wavelength of 800 nm to 2500 nm.

6. The composite material according to claim 1, wherein the composite material has a reflectance of 20% or more with respect to near-infrared electromagnetic radiation having a wavelength of 800 nm to 2500 nm.

7.

8. The composite material has a blackness degree (M ｙ ) of 130 to 165, the composite material according to claim 1. The composite material according to claim 1, wherein the black pigment is CuO having an average particle size of 5 microns or less.

9. The composite material according to claim 1, wherein the textile material is a synthetic polymer composition.

10. The composite material according to claim 1, wherein the textile material is selected from the group consisting of polyamide, polyacrylonitrile, polyethylene terephthalate (PET), polybutyrate, polyurethane, nylon, polyester, and combinations of two or more thereof.

11.

12. The composite material has a lightness L of 40 or less in the CIELAB color space ＊ The composite material according to claim 1, having such a color.

13. The composite material has a lightness L of 10 or less in the CIELAB color space ＊ The composite material according to claim 1, which has a color of

14. The composite material has a lightness L of 1 or less in the CIELAB color space ＊ The composite material according to claim 1, having a color as described above.

15. A composite material comprising CuO and a textile material, wherein the CuO has an average particle size of 5 microns or less, a composite material. The composite material has a lightness L of 40 or less in the CIELAB color space ＊ and has a color of

16.

17. The composite material according to claim 14, wherein the textile material is selected from the group consisting of polyamide, polyacrylonitrile, polyethylene terephthalate (PET), polybutyrate, polyurethane, nylon, polyester, and combinations of two or more thereof.

18. The composite material has a lightness L of 10 or less in the CIELAB color space ＊ The composite material according to claim 14, which has a color of

19. The composite material according to claim 14, wherein the composite material has a reflectance of 12% or more with respect to near-infrared electromagnetic radiation having a wavelength of 800 nm to 2500 nm.

20. The composite material according to claim 14, wherein the composite material has a reflectance of 10% or less with respect to visible light having a wavelength of 350 nm to 750 nm. Claim 19 The composite material has a blackness degree (M ｙ ) of 125 to 165, the composite material according to claim 14. Claim 20 A method for manufacturing a textile material doped with a black pigment, comprising combining the black pigment with the textile material to form a textile material doped with the black pigment, wherein the textile material doped with the black pigment has a reflectivity of 12% or more with respect to near-infrared electromagnetic radiation having a wavelength of 800 nm to 2500 nm, and the textile material doped with the black pigment has a reflectivity of 10% or less with respect to visible light having a wavelength of 350 nm to 750 nm, The textile material doped with the black pigment has a blackness degree M of 125 to 165 ｙ and has a method. Claim 21 The method according to claim 20, further comprising extruding the textile material doped with the black pigment to thereby produce a composite material fiber. Claim 22 The method according to claim 21, wherein the extruding comprises heating the textile material doped with the black pigment to the softening point of the textile material and stretching the textile material doped with the black pigment through a die. Claim 23 The method according to claim 21, wherein the extruding comprises heating the textile material doped with the black pigment to the melting point of the textile material and stretching the textile material doped with the black pigment through a die. Claim 24 The method according to claim 21, wherein the extruding comprises stretching the textile material doped with the black pigment through a spinneret to thereby produce filaments of the composite material fiber. Claim 25 The method according to claim 20, wherein the black pigment is CuO having an average particle size of 5 microns or less. Claim 26 The textile material doped with the black pigment has a lightness L of 40 or less in the CIELAB color space ＊ The method according to claim 20, which has a color of Claim 27 A fabric comprising the composite material according to claim 1. Claim 28 The fabric according to claim 27, wherein the black pigment is CuO having an average particle size of 5 microns or less.

Images