High near-infrared reflective blue pigment, and preparation method and application thereof

Abstract

The application discloses a high near-infrared reflective blue pigment, a preparation method and application thereof, and the chemical general formula of the pigment is YIn 0.9‑x Mn 0.1 M x O 3‑δ ; wherein: M is selected from at least one of Zn and Li; the value range of x is 0<=x<=0.4. The application provides a YIn 0.9 Mn 0.1 O3(b*=-45.91) near-infrared reflective pigment. The blue tone of the pigment can be made more rich (b* value is -29.59 to -55.14) by doping Li or Zn elements. And the blue pigment synthesized by the application has high near-infrared reflectivity (R%) and near-infrared solar reflectivity (R*%), and the color and reflectivity of the pigment can be adjusted by changing the doping concentration of Li or Zn elements. The blue pigment of the application can be applied to houses, vehicles and paint cans as a "cool" material.

Description

Technical Field

[0001] This invention relates to the field of pigment technology, specifically to a high near-infrared reflectance blue pigment, its preparation method, and its applications, and more particularly to a high near-infrared reflectance YIn pigment. 0.9-x Mn 0.1 M x O 3-δ (M=Li / Zn,x=0-0.4) Blue pigment, its preparation method and application. Background Technology

[0002] With urban expansion and the increase of man-made materials, the amount of natural vegetation has gradually decreased. Due to these changes, urban areas within the same region generally have higher temperatures than suburbs; this phenomenon is known as the urban heat island (UHI) effect. Heat emissions from human activities are one of the main causes of the urban heat island effect. These emissions primarily originate from transportation and industrial processes, as well as the widespread use of environmental comfort technologies, including heating, ventilation, and air conditioning (HVAC). Solar radiation consists of 5% ultraviolet light (295-400 nm), 43% visible light (400-700 nm), and 52% near-infrared light (700-2500 nm). Therefore, the near-infrared region of solar radiation accounts for a large portion of the absorbed heat, and studies have shown that coatings with high near-infrared (NIR) reflectivity can effectively reduce the UHI effect. Consequently, brightly colored, environmentally friendly pigments with high NIR reflectivity have attracted considerable attention from scholars.

[0003] Pigments can be broadly classified into two categories based on their chemical composition: organic blue pigments and inorganic blue pigments. Compared to organic pigments, inorganic pigments exhibit better resistance to acids and alkalis, high temperatures, and weathering. Currently, widely used inorganic blue pigments include cobalt blue (CoAl2O4) and ultramarine (Na6Al4Si6S4O4). 20 Ultramarine (Fe4[Fe(CN)6]3) and Prussian blue (Fe4[Fe(CN)6]3) are examples of blue pigments. Ultramarine has a bright color and good resistance to alkalis and high temperatures, but it is not acid-resistant and easily decomposes and discolors in acidic environments, thus limiting its practical applications. Prussian blue is neither alkali-resistant nor heat-resistant, and it reacts in weak acids to form HCN. Cobalt blue has high thermal and chemical stability; it is one of the most weather-resistant, light-resistant, heat-resistant (up to 1200℃), and chemically resistant blue pigments in the world. However, cobalt blue is expensive and contains toxic metal elements, thus limiting its application development. Therefore, the development of low-toxicity, stable, and environmentally friendly blue pigments is of great significance. Summary of the Invention

[0004] To improve the above-mentioned technical problems, the present invention provides a blue pigment with high near-infrared reflectance, its preparation method and application. The pigment of the present invention has excellent near-infrared reflectance and rich blue hues.

[0005] To achieve the above technical objectives, the present invention adopts the following technical solution:

[0006] A high near-infrared reflectance inorganic pigment, the pigment having the general chemical formula YIn 0.9-x Mn 0.1 M x O 3-δ ;

[0007] Wherein: M is selected from at least one of Zn and Li;

[0008] The range of x is 0 ≤ x ≤ 0.4, for example x = 0.1, 0.2, 0.3, 0.4.

[0009] According to an embodiment of the invention, the pigment has a hexagonal structure of space group P63cm(185).

[0010] According to an embodiment of the present invention, the pigment is prepared from raw materials including M source, Y source, In source and Mn source by a high-temperature solid-state sintering reaction method.

[0011] According to an embodiment of the present invention, the M source is provided by at least one of a Li source and a Zn source.

[0012] Preferably, the Li source is provided by at least one of Li-containing carbonates and molybdates; more preferably, it is provided by Li-containing carbonates.

[0013] Preferably, the Zn source is provided by at least one of Zn-containing oxides, chlorides, nitrates, and sulfates; more preferably, it is provided by Zn-containing oxides.

[0014] According to an embodiment of the present invention, the Y source is provided by at least one of carbonates, oxides, chlorides, nitrates and sulfates containing Y; preferably, it is provided by oxides containing Y.

[0015] According to an embodiment of the present invention, the In source is provided by at least one of an In-containing oxide, chloride, nitrate and sulfate; preferably, it is provided by an In-containing oxide.

[0016] According to an embodiment of the present invention, the Mn source is provided by at least one of oxides, chlorides and sulfates containing Mn; preferably, it is provided by oxides containing Mn.

[0017] This invention also provides a method for preparing the above-mentioned high near-infrared reflectance inorganic pigment, comprising the following steps: using M source, Y source, In source, and Mn source as raw materials, according to YIn 0.9-x Mn 0.1 M x O 3-δThe near-infrared reflective inorganic pigment is obtained by mixing the elements in stoichiometric proportions and then performing solid-state sintering.

[0018] According to an embodiment of the present invention, the M source, Y source, In source, and Mn source have the meanings described above.

[0019] According to an embodiment of the present invention, the solid-state sintering is performed by a two-stage calcination process. The temperature of the first-stage calcination is 700℃~800℃, with examples being 700℃, 800℃, and 900℃. The holding time of the first-stage calcination is 60~180min, with examples being 60min, 120min, and 180min.

[0020] The secondary calcination temperature is 800–1200℃, with examples of 1100℃, 1200℃, and 1300℃; the holding time for secondary calcination is 60–180 min, with examples of 60 min, 120 min, and 180 min.

[0021] According to an embodiment of the present invention, a grinding step is further included before the primary calcination treatment. For example, the grinding can be wet grinding or ball milling; preferably, the grinding medium can be acetone.

[0022] According to an embodiment of the present invention, the preparation method further includes drying the ground raw material.

[0023] According to an embodiment of the present invention, the secondary calcination treatment further includes a grinding step.

[0024] According to an embodiment of the present invention, the preparation method includes the following steps: [The text abruptly ends here, likely due to an incomplete sentence or missing information.] 0.9- x Mn 0.1 M x O 3-δ The raw materials of M source, Y source, In source and Mn source were weighed according to the stoichiometric ratio of each element, added to the grinding media for grinding, then dried and calcined. The calcined sample was ground again and dried to obtain blue pigment.

[0025] This invention also provides the above-mentioned YIn 0.9-x Mn 0.1 M x O 3-δ The application of pigments in the coloring and painting of houses, vehicles, paint cans and ceramics.

[0026] The present invention has the following beneficial effects:

[0027] 1. Rare earth ions have high valence, large radius, and are easily polarized. The higher the polarization intensity, the greater the refractive index. The high refractive index of rare earths can be used in ceramic pigments to make decorative patterns brighter. Rare earth elements act as chromophores in pigments. Doping rare earths into pigments can change the crystal phase structure or lattice parameters of the sample, resulting in special hues. In view of this, the present invention provides YIn doped with Li or Zn. 0.9 Mn 0.1 O3 (b* = -45.91) is a near-infrared reflective pigment. Doping with Li or Zn can enrich the blue hue of the pigment (b* value ranges from -29.59 to -55.14).

[0028] 2. The blue pigment synthesized in this invention exhibits high near-infrared reflectance (R%) and near-infrared solar reflectance (R*%). The pigment's color and reflectance can be adjusted by changing the doping concentration of Li or Zn elements. This blue pigment can be used as a "cool" material in houses, vehicles, and paint cans. Attached Figure Description

[0029] Figure 1 (a) is YIn 0.9-x Mn 0.1 Li x O 3-δ (x=0-0.4) XRD diffraction pattern of the pigment and a partial magnified view of the XRD diffraction pattern at 2θ=31.9-32.6°. Figure 1 (b) represents YIn 0.9-x Mn 0.1 Zn x O 3-δ (x=0-0.4) XRD diffraction pattern of the pigment and a magnified view of the XRD diffraction pattern at 2θ=31.9-32.6°.

[0030] Figure 2 forYIn 0.9-x Mn 0.1 M x O 3-δ (M=Li / Zn,x=0-0.4) SEM image of the pigment.

[0031] Figure 3 (a) is YIn 0.9-x Mn 0.1 Li x O 3-δ (x = 0 - 0.4) Particle size distribution of pigments. Figure 3 (b) represents YIn 0.9- x Mn 0.1 Zn x O 3-δ(x=0-0.4) Particle size distribution of pigment.

[0032] Figure 4 (a) is YIn 0.9-x Mn 0.1 Li x O 3-δ (x=0-0.4) Ultraviolet-visible diffuse reflectance diagram of the pigment. Figure 4 (b) represents YIn 0.9-x Mn 0.1 Zn x O 3-δ (x=0-0.4) Ultraviolet-visible diffuse reflectance diagram of the pigment.

[0033] Figure 5 forYIn 0.9-x Mn 0.1 M x O 3-δ (M=Li / Zn,x=0-0.4) CIE1931 coordinate graph of pigment colorimetry.

[0034] Figure 6 (a) is YIn 0.9-x Mn 0.1 Li x O 3-δ (x=0-0.4) Near-infrared reflectance diagram of pigments, Figure 6 (b) represents YIn 0.9-x Mn 0.1 Zn x O 3-δ (x=0-0.4) Near-infrared reflectance diagram of pigments.

[0035] Figure 7 (a) is YIn 0.9-x Mn 0.1 Li x O 3-δ (x=0-0.4) Near-infrared solar reflectance of the pigment. Figure 7 (b) represents YIn 0.9-x Mn 0.1 Zn x O 3-δ (x=0-0.4) Near-infrared solar reflectance of pigments.

[0036] Figure 8 For the synthesis of YIn 0.9-x Mn 0.1 M x O 3-δ (M=Li / Zn,x=0-0.4) Actual image of the pigment. Detailed Implementation

[0037] The present invention will be further described in detail below with reference to the embodiments. The described embodiments are merely illustrative and should not be construed as limiting the scope of protection of the present invention.

[0038] This invention provides a chemical formula of YIn 0.9-x Mn 0.1 M x O 3-δ A high near-infrared reflectance blue pigment (M = Li / Zn), wherein the value of x in the general chemical formula is in the range of 0 ≤ x ≤ 0.4.

[0039] In the following embodiments of the present invention, yttrium oxide was purchased from Shanghai Aladdin Reagent Co., Ltd.; lithium carbonate was purchased from Shanghai Energy Chemical Co., Ltd.; and indium oxide and manganese dioxide were purchased from Shanghai Maclean Biochemical Co., Ltd. All the above oxides and compounds had a purity ≥99%, and none of the reagents underwent further purification.

[0040] This invention also provides a method for preparing a blue inorganic pigment with high near-infrared reflectance, comprising the following steps:

[0041] Step 1: Weighing: According to the general formula YIn 0.9-x Mn 0.1 M x O 3-δ The stoichiometric ratios of each element in (M=Li / Zn) are measured sequentially from the Li source / Zn source, Y source, In source, and Mn source raw materials.

[0042] Step 2: Grinding: Add the weighed raw materials from Step 1 to an agate mortar and mix them. Use acetone as the wet grinding medium and grind until the acetone evaporates. Repeat the operation 3-4 times to obtain a uniformly mixed powder.

[0043] Step 3: Drying: Place the mixed powder obtained in Step 2 in an air oven at 60°C to dry;

[0044] Step 4: Pour the powder obtained in Step 3 into a crucible and place it in a muffle furnace for calcination. The muffle furnace calcination process is as follows: heat up to 800℃ and react for 120 min; then heat up to 1200℃ and hold for 120 min; finally, gradually cool to room temperature.

[0045] Step 5: Grind the sample obtained in Step 4 3-4 times again and then dry it to obtain blue pigment.

[0046] The crystal structure of the pigment powder was determined using a Rigaku Miniflex 600 X-ray diffractometer (Rigaku Corporation). The instrument employed a Cu-Kα target, and diffraction data were collected within the 2θ range of 10–90° at a scan rate of 8° / min and a step size of 0.02 under operating conditions of 40 kV and 15 mA. The surface morphology, size, and structural characteristics of the pigment samples were observed using a Hitachi SU1510 scanning electron microscope (SEM).

[0047] The UV-Vis-NIR diffuse reflectance of the pigment samples was tested using an Agilent Cary 5000 UV-Vis-NIR spectrophotometer. An appropriate amount of sample was filled into the powder cell and flattened. BaSO4 was used as a white standard for baseline correction, and the optical properties of the samples were measured in the wavelength range of 200-2500 nm (measurement accuracy 1 nm). The formula for calculating the near-infrared solar reflectance (R*) of the samples in the wavelength range of 700-2500 nm is as follows:

[0048]

[0049] Where r(λ) and i(λ) represent the spectral reflectance obtained from the test and the solar spectral irradiance (W·m) obtained from the ASTM G173-03 standard, respectively. -2 ·nm -1 ).

[0050] The band gap (Eg) of the pigment sample can be estimated using the reflectance data obtained from the test. The calculation formula is: Eg = Eg + ... g (eV)=h·c / λ=1239(eV·nm) / λ(nm), where: λ is the absorption limit of the sample in the reflectance spectrum of 200nm-800nm.

[0051] The chromaticity coordinates of the synthesized samples were measured using a CS-580A spectrophotometer manufactured by Hangzhou Caipu Technology Co., Ltd., under test conditions of a D65 standard light source and a 10° observation angle. The chromaticity coordinates of the pigments are defined by the CIE L*a*b* (1976) color space system. In this system, L* ranges from 0 (black) to 100 (white) and is used to characterize the brightness of the sample. The a* value represents the red-green characteristic of the pigment (positive value for red, negative value for green), and the b* value represents the yellow-blue characteristic of the pigment (positive value for yellow, negative value for blue). Both a* and b* range from -128 to +128. The C* (chromaticity) value represents the color saturation of the pigment, calculated using the formula: C* = [(a*)] 2 +(b*) 2 ] 1 / 2The parameter H° (0-360°) is used to represent the hue angle of the pigment and can be used to analyze the color gamut of the sample. The formula is defined as: H° = arctan(b* / a*).

[0052] Examples 1-9

[0053] YIn 0.9-x Mn 0.1 Li x O 3-δ (x=0-0.4), YIn 0.9-x Mn 0.1 Zn x O 3-δ (x=0-0.4) height

[0054] Preparation of near-infrared reflective blue pigment

[0055] Examples 1-9 were synthesized using solid-state sintering. The difference between the examples lies in the type and amount of raw materials used.

[0056] Table 1 lists the types and amounts of raw materials used in each embodiment.

[0057] A method for preparing a blue inorganic pigment with high near-infrared reflectance includes the following steps:

[0058] Step 1: Weighing: According to the general formula YIn 0.9-x Mn 0.1 M x O 3-δ The stoichiometric ratios of each element in (M=Li / Zn) are measured sequentially from the Li source / Zn source, Y source, In source, and Mn source raw materials.

[0059] Step 2: Grinding: Add the weighed raw materials from Step 1 to an agate mortar and mix them. Use acetone as the wet grinding medium and grind until the acetone evaporates. Repeat the operation 3-4 times to obtain a uniformly mixed powder.

[0060] Step 3: Drying: Place the mixed powder obtained in Step 2 in an air oven at 60°C to dry;

[0061] Step 4: Pour the powder obtained in Step 3 into a crucible and place it in a muffle furnace for calcination. The muffle furnace calcination process is as follows: heat up to 800℃ and react for 120 min; then heat up to 1200℃ and hold for 120 min; finally, gradually cool to room temperature.

[0062] Step 5: Grind the sample obtained in Step 4 3-4 times again and then dry it to obtain blue pigment.

[0063] Table 1 Preparation parameters for Examples 1-9

[0064]

[0065] Figure 1 In (a) and (b) respectively, YIn 0.9-x Mn 0.1 Li x O 3-δ (x=0-0.4) and YIn 0.9-x Mn 0.1 Zn x O 3-δ (x=0-0.4) XRD pattern of the pigment. The strong and sharp main diffraction peaks in the XRD pattern indicate that the pigment powder has a high degree of crystallinity. Comparison with standard PDF card No. 70-0133 shows that all doped samples have a hexagonal structure with space group P63cm(185). Furthermore, the absence of main diffraction peaks for Y2O3, In2O3, or MnO2 in the figure indicates that the present invention involves mixing the raw materials and then performing a two-stage calcination process on YIn... 0.9-x Mn 0.1 M x O 3-δ (M = Li / Zn, x = 0-0.4) The solid solution has been fully formed. Furthermore, the lattice volume gradually decreases with increasing doping concentration (Table 1), and the (112) crystal plane shifts to a higher angle as observed in the magnified 2θ (31.9°~32.6°) diagram. According to Bragg's law, the characteristic diffraction peaks of the sample will shift to a certain extent after the solid solution is formed. In this invention, In... 3+ Zn 2+ Or Li + The substitution results in smaller ionic radii entering the lattice, causing a certain degree of lattice contraction and a large-angle shift of the crystal planes. When the doping amount of Zn(II) and Li(I) is 0.1, the (111) crystal plane begins to converge and the peaks become sharper. When the doping amount is further increased, the diffraction peaks of the (112) and (304) crystal planes weaken, indicating that the crystallinity of the pigment first increases and then decreases with the increase of doping amount. This is mainly related to the change in the radius of metal ions before and after doping. When the doping amount of Zn(II) and Li(I) is 0.4, weak impurity peaks of ZnO and LiInO2 appear, respectively. In addition, the pigment also contains a small amount of unreacted cubic phase Y2O3 in the range of x = 0-0.4. Therefore, in order to maintain its high crystallinity and purity without affecting the performance of the pigment, the doping amount of Zn(II) and Li(I) should be controlled within 0.4.

[0066] Table 1 YIn 0.9-x Mn 0.1 M x O 3-δ(M = Li / Zn, x = 0 - 0.4) Calculation of pigment cell parameters and strain.

[0067]

[0068] Figure 2 It shows the chemical formula YIn 0.9-x Mn 0.1 M x O 3-δ (M = Li / Zn, x = 0-0.4) SEM images of the pigment powder. As can be seen from the images, the pigment samples prepared by doping with Zn(II) and Li(I) exhibit irregular morphologies. YIn 0.9 Mn 0.1 The doping of Zn and Li in O3 causes changes in particle size and morphology, accompanied by a certain degree of agglomeration, and the agglomerated particles are uneven in size.

[0069] Figure 3 In (a) and (b) respectively, YIn 0.9-x Mn 0.1 Li x O 3-δ (x=0-0.4) and YIn 0.9-x Mn 0.1 Zn x O 3-δ (x = 0-0.4) Particle size distribution diagram of pigments. It can be seen from the figure that the particle size of most samples is less than 2 μm and the distribution is uniform.

[0070] Table 2 records YIn 0.9-x Mn 0.1 M x O 3-δ (M = Li / Zn, x = 0-0.4) D10, D50, and D90 data for pigments, compared with undoped YIn 0.9 Mn 0.1 Compared to O3, the pigment YIn of this invention 0.9-x Mn 0.1 Zn x O 3-δ The particle size becomes smaller, while YIn 0.9- x Mn 0.1 Li x O 3-δ The particle size increases.

[0071] Table 2 YIn 0.9-x Mn 0.1 M x O 3-δ (M = Li / Zn, x = 0-0.4) D10, D50, D90 of pigment powder

[0072]

[0073] Figure 4 In (a) and (b) respectively, YIn 0.9-x Mn 0.1 Li x O 3-δ (x=0-0.4) and YIn 0.9-x Mn 0.1 Zn x O 3-δ (x = 0-0.4) UV-Vis diffuse reflectance spectrum of the pigment. As can be seen from the figure, the YIn of this invention... 0.9-x Mn 0.1 Li x O 3-δ (x=0-0.4) and YIn 0.9-x Mn 0.1 Zn x O 3-δ (x = 0-0.4) The pigment exhibits two main absorption regions in the UV-vis region: a low-energy absorption region centered at ~2 eV with a width of 1 eV, and a high-energy absorption region above 3 eV. Additionally, due to the pigment's blue color, there is a low-energy absorption region between 2.5-3 eV. In the low-energy absorption region, the peak at ~2 eV is related to Mn... 3+ dd transition (e'(d) x 2 -y 2 ,d xy ) to a'(d z 2 The peak at 2.2 eV is related to the forbidden 3d, and the peak value at 2.2 eV is due to the forbidden 3d. xz,yz To 3D z 2 This is caused by a weak transition. Absorption in the near-ultraviolet region is mainly related to O. 2p Bring to Mn 3dz 2 This is related to charge transfer transitions. The YIn of this invention can be observed in the figure. 0.9-x Mn 0.1 Li x O 3-δ (x=0-0.4) and YIn 0.9-x Mn 0.1 Zn x O 3-δ The high-energy absorption region (3.7-6.2 eV) of the doped pigment (x = 0-0.4) is lower than that of YIn. 0.9 Mn 0.1 O3, thus indicating the YIn of the present invention 0.9-x Mn 0.1 Li x O 3-δ (x=0-0.4) and YIn 0.9-x Mn 0.1 Zn x O 3-δ (x = 0-0.4) Doped pigments exhibit high reflectivity in the 200-350 nm wavelength range (ultraviolet region). When the doping concentration of Zn or Li is 0.1%, the low-energy absorption of the pigment reaches its maximum value, and then the low-energy absorption generally weakens with increasing doping concentration. For Li-doped pigments, with increasing Li doping concentration, the high-energy absorption peak initiation boundary first shifts blue and then red, thus reflected in the color change of the Li-doped sample. The results confirm that when the doping concentration of Zn or Li is 0.1%, YIn 0.9-x Mn 0.1 M x O 3-δ (M=Zn / Li,x=0-0.4) The pigments achieved the highest blue hue, and the band gaps of all synthesized samples were not in the near-infrared range (0.5-1.8eV), indicating that the synthesized pigments have high near-infrared reflectance (Table 3).

[0074] Table 3 YIn 0.9-x Mn 0.1 M x O 3-δ (M = Zn / Li, x = 0 - 0.4) Chromaticity coordinates and band gap of the pigment

[0075]

[0076] Figure 5 forYIn 0.9-x Mn 0.1 M x O 3-δ (M = Li / Zn, x = 0-0.4) CIE 1931 colorimetric coordinates of the pigment. Table 3 summarizes the YIn synthesized in this invention. 0.9-x Mn 0.1 M x O 3-δ (M = Li / Zn, x = 0-0.4) L*a*b* parameters of the pigment. From Figure 5 It can be observed that when the doping concentration of M (M = Li / Zn) is 0.1 and 0.2, compared with YIn 0.9 Mn 0.1 O3 pigment of the present invention YIn 0.9-x Mn 0.1 M x O 3-δ(M = Li / Zn, x = 0-0.4) The pigment exhibits a higher blue tint (b*) and a richer color saturation (C*). When the Li doping amount is 0.3, the YIn of this invention... 0.9-x Mn 0.1 M x O 3-δ (M = Li, x = 0-0.4) The b* value of the doped pigment increases sharply, indicating that the blue hue of the pigment gradually decreases. Furthermore, with the increase of Li doping amount, the YIn of this invention... 0.9- x Mn 0.1 M x O 3-δ (M = Li, x = 0-0.4) The a* value of the doped pigment first increases from 5.13 to 14.79, then decreases to 5.08, meaning that the red hue of the pigment first strengthens and then gradually decreases. Meanwhile, YIn doped with Zn... 0.9-x Mn 0.1 M x O 3-δ (M = Zn, x = 0-0.4) The L* value of the pigment increases with increasing doping concentration, indicating that the brightness of the pigment sample continuously increases. Meanwhile, all YIn in this invention... 0.9-x Mn 0.1 M x O 3-δ (M = Li / Zn, x = 0-0.4) The hue angle H° of the samples is distributed in the blue region (H° = 235°-295°). The above results indicate that almost all YIn of the present invention... 0.9-x Mn 0.1 M x O 3-δ (M=Li / Zn,x=0-0.4) The doped pigment samples are all distributed in the bright blue region.

[0077] All YIn of this invention 0.9-x Mn 0.1 M x O 3-δ (M = Li / Zn, x = 0-0.4) Photographs of the pigments are as follows Figure 8 As shown in the figure, it can be seen that the color of the pigment sample doped with Li changes significantly with the increase of doping amount, while the color of the pigment sample doped with Zn changes less.

[0078] Figure 6 In (a) and (b) respectively, YIn 0.9-x Mn 0.1 Li x O 3-δ (x=0-0.4) and YIn 0.9-x Mn 0.1 Zn x O3-δ (x = 0-0.4) Near-infrared reflectance graph of the pigment. The graph shows that doping with Li and / or Zn elements affects the near-infrared reflectance of the pigment. Furthermore, with increasing Li / Zn doping concentration, the near-infrared reflectance (R%) of the pigment first increases and then decreases, reaching its maximum value at a doping concentration of 0.2%. The Li-doped pigments all exhibit reflectances above 90% at 1100 nm, reaching a maximum of 97.76%; the zinc-doped pigments all exhibit reflectances above 83% at 1100 nm; and the near-infrared reflectances of all pigment samples doped in this invention are higher than those of YIn. 0.9 Mn 0.1 O3, as shown in Table 4.

[0079] Table 4 YIn 0.9-x Mn 0.1 M x O 3-δ (M=Zn / Li,x=0-0.4) Near-infrared reflectance (1100nm) and near-infrared solar reflectance of the pigment.

[0080]

[0081] Figure 7 In (a) and (b) respectively, YIn 0.9-x Mn 0.1 Li x O 3-δ (x=0-0.4) and YIn 0.9-x Mn 0.1 Zn x O 3-δ (x = 0-0.4) Near-infrared solar reflectance of the pigment. The near-infrared solar reflectance curves of the pigment samples were calculated using ASTM standard G173-03. The near-infrared solar reflectance (R*) of the pigments doped with Li and / or Zn elements in this invention is higher than 71.73%, and the highest value can reach 86.13% (M = Li, x = 0.2), which is higher than that of YIn before doping. 0.9 Mn 0.1 The O3 content in the sample was 16.17% (Table 4), thus exhibiting good thermal insulation performance in practical applications.

[0082] In summary, this invention successfully synthesized YIn using a solid-state reaction method. 0.9 Mn 0.1O3 is used as the matrix for this high-infrared-reflectance inorganic blue pigment. Furthermore, the doping of Li / Zn elements enriches the pigment's blue hue (b* from -29.59 to -55.14), thus meeting public demand for blue pigments. All doped samples of this invention possess a hexagonal structure with space group P63cm(185), and at 1100 nm, the near-infrared reflectance ranges from 83.07% to 97.76%, with the highest near-infrared solar reflectance reaching 86.13%, which is higher than that of undoped YIn. 0.9 Mn 0.1 O3 content is approximately 16% higher. The above results fully demonstrate the effectiveness of this invention in doping YIn with lithium / zinc. 0.9-x Mn 0.1 Li x O 3-δ (x=0-0.4) and YIn 0.9-x Mn 0.1 Zn x O 3-δ (x=0-0.4) Pigments have good heat insulation properties, and therefore have the potential to be used as cold materials.

[0083] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications, equivalent substitutions, refinements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing a high near-infrared reflectance blue pigment, characterized in that, The general chemical formula of the pigment is YIn 0.9-x Mn 0.1 M x O 3-δ ; Wherein: M is selected from Zn or Li; The range of x is 0.1 ≤ x ≤ 0.4; The preparation method includes the following steps: using M source, Y source, In source, and Mn source as raw materials, according to YIn 0.9-x Mn 0.1 M x O 3-δ The stoichiometric ratios of the various elements in the mixture are combined, and solid-state sintering is used to obtain the high near-infrared reflectance blue pigment. The solid-state sintering process employs a two-stage calcination treatment, with the first-stage calcination temperature being 700℃~800℃ and the first-stage calcination holding time being 60~180min. The secondary calcination temperature is 800~1200℃; the holding time for secondary calcination is 60~180min.

2. The preparation method according to claim 1, characterized in that, The M source is either a Li source or a Zn source; The Li source is provided by at least one of Li-containing carbonates and molybdates; The Zn source is provided by at least one of Zn-containing oxides, chlorides, nitrates, and sulfates.

3. The preparation method according to claim 1, characterized in that, The Y source is provided by at least one of carbonates, oxides, chlorides, nitrates, and sulfates containing Y.

4. The preparation method according to claim 1, characterized in that, The In source is provided by at least one of oxides, chlorides, nitrates and sulfates containing In.

5. The preparation method according to claim 1, characterized in that, The Mn source is provided by at least one of oxides, chlorides and sulfates containing Mn.

6. The preparation method according to claim 1, characterized in that, The primary calcination process includes a grinding step, wherein the grinding is wet grinding and the grinding medium is acetone.

7. The preparation method according to claim 6, characterized in that, The preparation method also includes drying the ground raw materials.

8. The preparation method according to claim 1, characterized in that, The secondary calcination treatment also includes a grinding step.

9. The use of the high near-infrared reflectance blue pigment prepared by the preparation method according to any one of claims 1-8 in the coloring and painting of houses, vehicles, paint cans and ceramics.

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