High near-infrared reflection material and preparation method thereof

Abstract

The invention provides a novel material with high near infrared reflection performance. The general formula of the novel material is Nd < 2-x > Bi < x > MoO < 6 >. Compared with the prior art, the near-infrared reflection material of the system is a blue pigment, a light purple pigment and a purple gray pigment which are tunable, has higher near-infrared reflection performance, has bright color on the basis of excellent performance, and solves the problem of color vacancy in the market. And the material is an inorganic pigment, does not contain heavy metal oxides such as Cd, Cr and the like, is friendly to human bodies and the environment, and conforms to the green and environment-friendly concept. Meanwhile, the near-infrared reflecting material is simple in preparation process, stable in product chemical property, easy in powder grinding, uniform in chromaticity, free of radioactivity and suitable for industrial production and general popularization and application.

Description

Technical Field

[0001] The invention relates to the technical field of materials, and in particular to a high near-infrared reflective material and a preparation method thereof. Background Art

[0002] In recent years, with the intensification of the heat island effect, the demand for innovative materials in the field of energy conservation and emission reduction has become increasingly urgent. Since the 1970s, foreign countries have begun to study this kind of coating that reduces surface temperature by having high reflectivity. Near-infrared reflective pigments can be widely used in architectural coatings and other fields. my country has also successively introduced a series of building energy-saving standards, attaches importance to the research and development of building energy-saving, and the research and development prospects of energy-saving coatings have become broad. Inorganic pigments have an important position in energy-saving materials because of their high sunlight reflectivity and near-infrared reflectivity, stable performance and excellent weather resistance. The existing near-infrared reflective pigments either have serious environmental pollution problems or have a single color selection, mainly concentrated in yellow and white. Therefore, it is of great significance to develop environmentally friendly, colorful, high near-infrared reflective pigments.

[0003] In recent years, some near-infrared reflective materials based on rare earth ions have also been studied and explored. Raj et al. used a high-temperature solid-phase method to dope terbium ions to synthesize a yellow pigment Sr2M with excellent color and high near-infrared reflectivity. 1-x Tb x O4(M=Sn, Zr).

[0004] Currently available near-infrared reflective pigments are mostly white, causing light pollution and poor dirt resistance. Some yellow pigments contain heavy metals that are harmful to the human body and the environment. In addition, the yellow near-infrared reflective coatings composed of these pigments have a single color tone, poor reflectivity in the near-infrared band, and poor reflective barrier properties to solar heat, which is not conducive to environmental protection.

[0005] Therefore, it is urgent to develop more colorful inorganic environmentally friendly pigments with high near-infrared reflectivity for use in daily construction. Summary of the invention

[0006] In view of this, the technical problem to be solved by the present invention is to provide an environmentally friendly infrared reflective material with high near-infrared reflective performance and color.

[0007] The present invention provides a high near-infrared reflective material of the general formula (I):

[0008] Nd 2-x Bi x MoO6, formula (I)

[0009] Wherein the range of x is 0≤x≤1.

[0010] Specifically, x may be 0, 0.2, 0.4, 0.6, 0.8 or 1.0.

[0011] In some embodiments of the present invention, the high near-infrared reflective material includes Nd2MoO6, Nd 1.8 Bi 0.2 MoO6、Nd 1.6 Bi 0.4 MoO6、Nd 1.4 Bi 0.6 MoO6、Nd 1.2 Bi 0.8 MoO6.

[0012] The present invention provides a method for preparing a high near-infrared reflective material, comprising the following steps:

[0013] A) mixing a neodymium source, a bismuth source and a molybdenum source, and grinding to obtain a mixture;

[0014] B) calcining and grinding the mixture to obtain a high near infrared reflective material.

[0015] The preparation method of the high near-infrared reflective material provided by the invention comprises firstly mixing a neodymium source, a bismuth source and a molybdenum source.

[0016] According to the present invention, the bismuth source includes any one or a combination of two of bismuth oxide, bismuth carbonate, bismuth nitrate, bismuth oxalate, bismuth halide or bismuth sulfide;

[0017] The neodymium source includes one or a combination of at least two of neodymium oxide, neodymium halide, neodymium nitrate, and neodymium sulfate;

[0018] The molybdenum source includes one or a combination of at least two of molybdenum oxide, molybdenum sulfide, molybdenum molybdate, and molybdenum nitrate.

[0019] The bismuth source of the present invention includes Nd2O3; the bismuth source includes Bi2O3; the molybdenum source includes (NH4)6Mo7O 14 ;

[0020] The ratio of mixing the neodymium source, the bismuth source and the molybdenum source is preferably the molar ratio described in the above molecular formula;

[0021] Preferably:

[0022] Nd2O3:Bi2O3:(NH4)6Mo7O 14 =(1-x / 2):x / 2:1 / 7.

[0023] In some embodiments of the present invention, the grinding time is 25 to 35 min, preferably 30 min, specifically 25 min, 27 min, 29 min, 30 min, 32 min or 35 min, or a range between any two of the above.

[0024] The grinding devices of the present invention are all agate mortars.

[0025] The neodymium source of the present invention should be pre-burned before weighing to remove excess moisture and carbon dioxide. The pre-burning temperature is 900-1000°C, and the sintering time is 1 hour; the pre-burning temperature can be 900°C, 920°C, 940°C, 950°C, 960°C, 980°C, 1000°C; or a range between any two of the above.

[0026] The mixture is calcined; the calcination in the present invention is carried out under an atmosphere; the calcination atmosphere is air, nitrogen, helium, neon or argon.

[0027] In some embodiments of the present invention, the calcination parameters include a temperature of 900 to 1000° C. and a time of 1 to 4 hours.

[0028] The calcination temperature of the present invention can be 900° C., 920° C., 940° C., 950° C., 960° C., 980° C., 1000° C., or a range between any two of the above.

[0029] The calcination time of the present invention can be 1 h, 2 h, 3 h or 4 h; or a range between any two of the above.

[0030] After calcination, the material is ground to obtain a high near-infrared reflective material; after natural cooling, the sample is taken out and ground to obtain a high near-infrared reflective material; the grinding device is an agate mortar; the grinding time is 5-30 minutes.

[0031] The present invention provides the use of the high near-infrared reflective material described above or the high near-infrared reflective material prepared by the preparation method described in any one of the above technical solutions in architectural coatings, smart window glass coatings, aerospace or temperature indicators.

[0032] The general formula of a novel material with high near-infrared reflection performance provided by the present invention is: Nd 2-x Bi x MoO6. Compared with the prior art, the near-infrared reflective material of the invention system is tunable with blue pigment, lavender pigment and purple-gray pigment, has high near-infrared reflective performance, and has bright colors on the basis of excellent performance, which fills the problem of color vacancies on the market. Moreover, this material is an inorganic pigment, does not contain heavy metal oxides such as Cd and Cr, is friendly to the human body and the environment, and conforms to the concept of green environmental protection. At the same time, the preparation process of the near-infrared reflective material is simple, the product has stable chemical properties, the powder is easy to grind and has uniform chromaticity, and is non-radioactive, which is suitable for industrial production and widespread promotion and use. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1is the X-ray powder diffraction spectrum (XRD) of the high near-infrared reflective material prepared in Example 1 of the present invention;

[0034] Figure 2 is a scanning electron microscope (SEM) image of the high near-infrared reflective material prepared in Example 1 of the present invention at room temperature;

[0035] Figure 3 is the near-infrared diffuse reflectance spectrum of the high near-infrared reflective material prepared in Example 1 of the present invention;

[0036] Figure 4 This is an optical photograph of the high near-infrared reflective material prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0037] The present invention provides a high near-infrared reflective material and a method for preparing the same. Those skilled in the art can refer to the contents of this article and appropriately improve the process parameters to achieve the same. It should be particularly noted that all similar substitutions and modifications are obvious to those skilled in the art and they all fall within the scope of protection of the present invention. The methods and applications of the present invention have been described through preferred embodiments, and relevant personnel can obviously modify or appropriately change and combine the methods and applications of this article without departing from the content, spirit and scope of the present invention to implement and apply the technology of the present invention.

[0038] It should be understood that the expression "one or more of..." includes each of the items recited after the expression individually and in various different combinations of two or more of the recited items, unless otherwise understood from the context and usage. The expression "and / or" in combination with three or more recited items should be understood to have the same meaning, unless otherwise understood from the context.

[0039] The use of the terms "comprising", "having" or "containing", including their grammatical synonyms, should generally be understood as open and non-restrictive, for example not excluding other unrecited elements or steps, unless otherwise specifically stated or otherwise understood from the context.

[0040] In this application, the term "and / or" describes the association relationship of associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. A and B can be singular or plural.

[0041] In this application, "at least one" means one or more, "more than one" means two or more. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items.

[0042] It should be understood that the order of steps or the order in which certain actions are performed is not important as long as the present invention remains operable. In addition, two or more steps or actions may be performed simultaneously.

[0043] The use of any and all examples or exemplary language, such as "for example" or "including", herein is intended only to better illustrate the invention and does not limit the scope of the invention unless otherwise claimed. No language in this specification should be construed as indicating that any non-claimed element is essential to the practice of the invention.

[0044] In addition, the numerical ranges and parameters used to define the present invention are approximate values, and the relevant values ​​in the specific embodiments have been presented as accurately as possible. However, any numerical value inherently inevitably contains standard deviations due to individual test methods. Therefore, unless otherwise expressly stated, it should be understood that all ranges, quantities, values ​​and percentages used in this disclosure are modified by "about". Here, "about" generally means that the actual value is within plus or minus 10%, 5%, 1% or 0.5% of a specific value or range.

[0045] It should be understood that in the various embodiments of the present application, the size of the serial numbers of the above-mentioned processes does not mean the order of execution, some or all of the steps can be executed in parallel or sequentially, and the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0046] Some cases are recorded in the embodiments and comparative examples of the present invention, wherein the embodiments show certain implementation modes of the present invention. However, this does not mean that the effects of the present invention can only be achieved in these cases.

[0047] In order to further illustrate the present invention, a high near-infrared reflective material and a preparation method thereof provided by the present invention are described in detail below in conjunction with embodiments.

[0048] Embodiment 1:

[0049] A high near-infrared reflective material (Bi 3+ When the doping amount x=0), the method comprises the following steps:

[0050] The raw materials are Nd2O3 (99.90%), Bi2O3 (99.00%) and (NH4)6Mo7O 14 ·4H2O (99.00%), weigh the raw materials according to the above proportion, mix them evenly in an agate mortar and grind them for about 30 minutes, then put them into an alumina crucible and calcine them in air at 1000℃ for 4 hours. After natural cooling, take out the sample and grind it to obtain a high near-infrared reflective material. The obtained material is a blue powder (such as Figure 4As shown), the molecular formula is Nd2MoO6, and the XRD spectrum of the material is as follows Figure 1 As shown in the figure, the narrow and sharp characteristic peaks indicate that the synthesized sample has good crystallization performance; the SEM image of the material is shown in Figure 2 As shown in (a), the sample is irregularly granular; the UV-visible-near-infrared reflectance of the material is as follows Figure 3 As shown, the material has a high near-infrared reflectivity.

[0051] Embodiment 2:

[0052] A high near-infrared reflective material (Bi 3+ When the doping amount x=0.2), the steps include:

[0053] The raw materials are Nd2O3 (99.90%), Bi2O3 (99.00%) and (NH4)6Mo7O 14 ·4H2O (99.00%), first pre-sinter Nd2O3 in a muffle furnace at 1000℃ for 1 hour, then weigh the raw materials according to the above proportion, mix them evenly in an agate mortar and grind them for about 30 minutes, then put them in an alumina crucible, calcine them in air at 1000℃ for 4 hours, take out the sample after natural cooling and grind it to obtain a high near-infrared reflective material. The obtained material is a blue powder (such as Figure 4 As shown), the molecular formula is Nd 1.8 Bi 0.2 MoO6, the XRD spectrum of the material is as follows Figure 1 As shown in the figure, the sample crystallized into the same structure as the matrix. The narrow and sharp characteristic peaks in the figure indicate that the synthesized sample has good crystallization performance; the SEM image of the material is shown in Figure 2 As shown in (b), the sample is irregularly granular; the UV-visible-near-infrared reflectance of the material is as follows Figure 3 As shown, the material has a high near-infrared reflectivity.

[0054] Embodiment 3:

[0055] A high near-infrared reflective material (Bi 3+ When the doping amount x=0.4), the steps include:

[0056] The raw materials are Nd2O3 (99.90%), Bi2O3 (99.00%) and (NH4)6Mo7O 14 4H2O (99.00%), first pre-sinter Nd2O3 in a muffle furnace at 1000℃ for 1 hour, then weigh the raw materials according to the above proportion, mix them evenly in an agate mortar and grind them for about 30 minutes, then put them in an alumina crucible, calcine them in air at 1000℃ for 4 hours, take out the sample after natural cooling and grind it to obtain a high near-infrared reflective material. The obtained powder is blue or lavender (such as Figure 4As shown), the molecular formula is Nd 1.6 Bi 0.4 MoO6, the XRD spectrum of the material is as follows Figure 1 As shown in the figure, the sample crystallized into the same structure as the matrix. The narrow and sharp characteristic peaks in the figure indicate that the synthesized sample has good crystallization performance; the SEM image of the material is shown in Figure 2 As shown in (c), the sample is irregularly granular; the UV-visible-near-infrared reflectance of the material is as follows Figure 3 As shown, the material has a high near-infrared reflectivity.

[0057] Embodiment 4:

[0058] A high near-infrared reflective material (Bi 3+ When the doping amount x=0.6), the steps include:

[0059] The raw materials are Nd2O3 (99.90%), Bi2O3 (99.00%) and (NH4)6Mo7O 14 4H2O (99.00%), first pre-sinter Nd2O3 in a muffle furnace at 1000℃ for 1 hour, then weigh the raw materials according to the above proportion, mix them evenly in an agate mortar and grind them for about 30 minutes, then put them in an alumina crucible and calcine them in air at 1000℃ for 4 hours. After natural cooling, take out the sample and grind it to obtain a high near-infrared reflective material. The obtained material is a lavender powder (such as Figure 4 As shown), the molecular formula is Nd 1.4 Bi 0.6 MoO6, the XRD spectrum of the material is as follows Figure 1 As shown in the figure, the sample crystallized into the same structure as the matrix. The narrow and sharp characteristic peaks in the figure indicate that the synthesized sample has good crystallization performance; the SEM image of the material is shown in Figure 2 As shown in (d), the sample is irregularly granular; the UV-visible and near-infrared reflectance of the material is as follows: Figure 3 As shown, the material has a high near-infrared reflectivity.

[0060] Embodiment 5:

[0061] A high near-infrared reflective material (Bi 3+ When the doping amount x=0.8), the steps include:

[0062] The raw materials are Nd2O3 (99.90%), Bi2O3 (99.00%) and (NH4)6Mo7O 14·4H2O (99.00%), first pre-sinter Nd2O3 in a muffle furnace at 1000℃ for 1 hour, then weigh the raw materials according to the above proportions, mix them evenly in an agate mortar and grind them for about 30 minutes, then put them in an alumina crucible and calcine them in air at 1000℃ for 4 hours. After natural cooling, take out the sample and grind it to obtain a high near-infrared reflective material. The obtained material is a purple-gray powder (such as Figure 4 As shown), the molecular formula is Nd 1.2 Bi 0.8 MoO6, the XRD spectrum of the material is as follows Figure 1 As shown in the figure, the sample crystallized into the same structure as the matrix. The narrow and sharp characteristic peaks in the figure indicate that the synthesized sample has good crystallization performance; the SEM image of the material is shown in Figure 2 As shown in (e), the sample is irregularly granular; the UV-visible-near-infrared reflectance of the material is Figure 3 As shown, the material has a high near-infrared reflectivity.

[0063] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A high near-infrared reflective material of formula (I): Nd 2-x Bi x MoO6, formula (I) Wherein the range of x is 0≤x≤1.

2. The high near-infrared reflective material according to claim 1, characterized in that: Nd2MoO6、Nd 1.8 The 0.2 MoO6、Nd 1.6 The 0.4 MoO6、Nd 1.4 The 0.6 MoO6、Nd 1.2 The 0.8 MoO6。 3. The method for preparing the high near-infrared reflective material according to claim 1 or 2, characterized in that: The steps include: A) mixing a neodymium source, a bismuth source and a molybdenum source, and grinding to obtain a mixture; B) calcining and grinding the mixture to obtain a high near infrared reflective material.

4. The method for preparing a high near-infrared reflective material according to claim 3, characterized in that: The bismuth source includes any one or a combination of two of bismuth oxide, bismuth carbonate, bismuth nitrate, bismuth oxalate, bismuth halide or bismuth sulfide; The neodymium source includes one or a combination of at least two of neodymium oxide, neodymium halide, neodymium nitrate, and neodymium sulfate; The molybdenum source includes one or a combination of at least two of molybdenum oxide, molybdenum sulfide, molybdenum molybdate, and molybdenum nitrate.

5. The method for preparing a high near-infrared reflective material according to claim 3, characterized in that: The grinding time in step A) is 25 to 35 minutes.

6. The method for preparing a high near-infrared reflective material according to claim 3, characterized in that: Step A) also includes pre-firing the neodymium source; the pre-firing temperature is 900-1000° C. and the sintering time is 1 hour.

7. The method for preparing a high near-infrared reflective material according to claim 3, characterized in that: The calcination in step B) is carried out under an atmosphere; the calcination atmosphere is air, nitrogen, helium, neon or argon.

8. The method for preparing a high near-infrared reflective material according to claim 3, characterized in that: The parameters of the calcination in step B) include a temperature of 900 to 1000° C. and a time of 1 to 4 hours.

9. The method for preparing a high near-infrared reflective material according to claim 3, characterized in that: The grinding device is an agate mortar.

10. Use of the high near-infrared reflective material according to any one of claims 1 to 2 or the high near-infrared reflective material prepared by the preparation method according to any one of claims 3 to 9 in architectural coatings, smart window glass coatings, aerospace or temperature indicators.

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