A preparation method of an infrared stealth coating slurry

Abstract

The application discloses a preparation method of an infrared stealth coating slurry, and the infrared stealth coating slurry is composed of the following components in parts by weight: water-based polyurethane emulsion 80-120 parts, graphene powder 10-15 parts, MXene dispersion liquid 15-20 parts, silica aerogel powder 10-15 parts, hollow glass microbead 20-30 parts, thickening agent 1-2 parts, binder 5-10 parts, foaming agent 8-12 parts, foam stabilizer 15-18 parts, dispersing agent 3-5 parts and soft water 30-40 parts. The application can significantly reduce the conduction of target heat, thereby effectively reducing the infrared radiation energy of the target, and the infrared stealth textile coating with heat reflection and blocking performance and flame retardation performance meets the actual stealth demand in a battlefield, has a wide application prospect, and has a very important significance for promoting the development of stealth technology.

Description

Technical Field

[0001] This invention belongs to the field of infrared stealth materials technology, and particularly relates to a method for preparing an infrared stealth coating slurry. Background Technology

[0002] With the rapid development of infrared detection and imaging technologies, infrared detection technology is playing an increasingly important role in military warfare. Consequently, infrared stealth technology, a countermeasure against infrared stealth, has received high attention from various countries. Infrared stealth technology is an effective means of altering the infrared radiation characteristics of a target and reducing the probability of the target being detected by infrared detectors. Its key lies in the preparation of low infrared emissivity materials with stealth properties.

[0003] Infrared radiation refers to electromagnetic waves with wavelengths ranging from 0.78 to 1000 μm, also known as thermal radiation, and is the most widespread form of radiation in nature. As long as the temperature of an object is above absolute zero (-273°C), the molecules that make them up are constantly in random thermal motion and continuously emit thermal infrared radiation. The most effective way to prevent infrared detection is to make the infrared signature of the target as close as possible to the infrared signature of the background, thus making it difficult to distinguish the target from the background using thermal infrared detection methods. Since the radiation of general military targets is stronger than that of the background, using low-emissivity coatings can significantly reduce the infrared radiation energy of the target. On the other hand, thermal infrared stealth coatings are used to reduce the surface temperature of the target.

[0004] Currently, infrared stealth materials include stealth coatings, stealth tarpaulins, and stealth films. Infrared stealth coatings, due to their simple processing, convenient application, durability, and low cost, are the most important type of stealth coating and occupy a crucial position in the field of infrared stealth. Existing infrared stealth fabrics are various infrared stealth materials developed around fabrics, often based on high-performance fiber fabrics. Infrared stealth coatings are applied to the fabric surface through spraying, scraping, or deposition. Therefore, the performance of the infrared stealth coating is a crucial factor determining the stealth performance of the fabric. Existing infrared stealth coatings are typically formulated with fillers, solvents, and binders. Pigments include metals, semiconductors, coloring pigments, and conductive polymers. However, coatings composed of these materials do not have ideal overall infrared stealth performance. They cannot simultaneously achieve both heat insulation and heat reflection blocking properties, making it difficult to control the heat conduction of the target, resulting in poor heat reflection blocking performance, and their flame retardancy needs improvement.

[0005] Therefore, developing an infrared stealth textile coating that can significantly reduce the conduction of heat from a target, thereby effectively reducing the infrared radiation energy of the target, while also possessing heat reflection and blocking properties as well as flame retardant properties, meets the actual stealth requirements of the battlefield, has broad application prospects, and is of great significance to promoting the development of stealth technology. Summary of the Invention

[0006] In view of the shortcomings of the existing technology, the technical problem to be solved by the present invention is to provide a method for preparing an infrared stealth coating paste that can significantly reduce the conduction of heat of the target, thereby effectively reducing the infrared radiation energy of the target, while having heat reflection and blocking properties.

[0007] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a method for preparing an infrared stealth coating slurry, wherein the infrared stealth coating slurry is composed of the following components in parts by weight:

[0008]

[0009]

[0010] In the above-mentioned method for preparing infrared stealth coating slurry, the density of the hollow glass microspheres is 0.2-0.4 g / cm³. 3 The particle size is 40-100 μm.

[0011] In the above-mentioned method for preparing infrared stealth coating slurry, the concentration of the MXene dispersion is 20 mg / mL.

[0012] The above-mentioned method for preparing infrared stealth coating slurry uses silica aerogel powder with a particle size of 120μm-300μm, a density of 0.12g / mL-0.25g / mL, and a porosity of 80-95%.

[0013] In the above-mentioned method for preparing infrared stealth coating slurry, the thickener is any one of polyvinyl alcohol, polyacrylate, and cellulose derivatives, and the binder is epoxy resin or silane-modified acrylic resin.

[0014] In the above-mentioned method for preparing infrared stealth coating slurry, the foaming agent is alkylbenzene sulfonate, the foam stabilizer is silicone polyether emulsion, and the dispersant is any one of polyacrylate, cellulose derivative, and triethylhexyl phosphate.

[0015] The above-mentioned method for preparing infrared stealth coating slurry further includes low infrared emissivity powder, which is aluminum-doped zinc oxide, and the addition amount is 10-20 parts.

[0016] The preparation method of the infrared stealth coating slurry described above includes the following steps:

[0017] I. Graphene / MXene base slurry

[0018] (1) A certain amount of graphene powder was added to softened water, and after wet ball milling, ultrasonic treatment and centrifugation, a graphene dispersion with a concentration of 20wt% was prepared for use.

[0019] (2) Add the waterborne polyurethane emulsion, MXene dispersion and adhesive to the graphene dispersion prepared in step (1) according to the corresponding weight parts, and stir at 3000r / min for 1-2 hours.

[0020] (3) Add the corresponding amount of thickener by weight, stir at 600 r / min for 8-10 min to obtain graphene / MXene basic slurry for later use;

[0021] II. Composite Functional Slurry:

[0022] (4) Add silica aerogel powder and hollow glass microspheres to the graphene / MXene base slurry prepared in step (3) according to the corresponding weight parts, stir thoroughly to obtain composite functional slurry;

[0023] III. Foaming:

[0024] (5) Transfer the composite functional slurry obtained in step (4) to the foaming equipment;

[0025] (6) Add the foaming agent, foam stabilizer and dispersant to the foaming equipment in the corresponding weight parts in sequence, and stir evenly;

[0026] (7) Turn on the foaming equipment and foam at 20-30℃ to obtain infrared stealth coating slurry.

[0027] The method for preparing the infrared stealth coating slurry described above is characterized in that: in step (4), 10-20 parts of low infrared emissivity powder are added, and the low infrared emissivity powder is aluminum-doped zinc oxide.

[0028] The advantages of the preparation method of the infrared stealth coating slurry of this invention are as follows: This invention combines silica aerogel powder with foamed coating slurry, utilizing the porous three-dimensional breathable structure after foaming to effectively and uniformly encapsulate and fix most of the aerogel functional powder inside the coating slurry. The resulting coated fabric mainly consists of aerogel powder material encapsulated in polyurethane, maintaining the thermal insulation properties of aerogel while possessing the excellent elongation properties of polyurethane itself. This results in a soft and comfortable feel to the entire coated fabric without silica aerogel shedding, thus not affecting the normal wear and use of the clothing. It also ensures the durability of the infrared stealth fabric. Furthermore, the addition of hollow glass microspheres makes the foam in the slurry more uniform and stable, with more ideal lateral uniformity. This allows graphene, MXene, and silica aerogel powder to be uniformly dispersed on the fabric surface, forming a uniform coating and improving the uniformity of the infrared stealth effect. It achieves the goal of being both waterproof and breathable, while also preventing vertical heat loss. Detailed Implementation

[0029] The present invention will be further described in detail below with reference to specific embodiments.

[0030] In this invention, unless otherwise stated, directional terms such as "upper" and "lower" generally refer to the upper and lower positions of the device in its actual use or operating state; while "inner" and "outer" refer to the outline of the device. Furthermore, in the description of this application, the term "comprising" means "including but not limited to". The terms first, second, third, etc., are used merely as illustrative purposes and do not impose numerical requirements or establish an order. The term "multiple" means "two or more".

[0031] A method for preparing an infrared stealth coating slurry, the infrared stealth coating slurry being composed of the following components in parts by weight: 80-120 parts of aqueous polyurethane emulsion; 10-15 parts of graphene powder; 15-20 parts of MXene dispersion; 10-15 parts of silica aerogel powder; 20-30 parts of hollow glass microspheres; 1-2 parts of thickener; 5-10 parts of binder; 8-12 parts of foaming agent; 15-18 parts of foam stabilizer; 3-5 parts of dispersant; and 30-40 parts of softened water.

[0032] The density of the hollow glass microspheres is 0.2-0.4 g / cm³. 3The particle size is 40–100 μm. The concentration of the MXene dispersion is 20 mg / mL. The particle size of the silica aerogel powder is 120 μm–300 μm, the density is 0.12 g / mL–0.25 g / mL, and the porosity is 80–95%. The thickener is any one of polyvinyl alcohol, polyacrylates, or cellulose derivatives, and the binder is epoxy resin or silane-modified acrylic resin. The foaming agent is alkylbenzene sulfonate, the foam stabilizer is silicone polyether emulsion, and the dispersant is any one of polyacrylates, cellulose derivatives, or triethylhexylphosphoric acid. The infrared stealth coating slurry also includes a low infrared emissivity powder, which is aluminum-doped zinc oxide, added at an amount of 10–20 parts.

[0033] The preparation method includes the following steps:

[0034] I. Graphene / MXene base slurry

[0035] (1) A certain amount of graphene powder was added to softened water, and after wet ball milling, ultrasonic treatment and centrifugation, a graphene dispersion with a concentration of 20wt% was prepared for use.

[0036] (2) Add the waterborne polyurethane emulsion, MXene dispersion and adhesive to the graphene dispersion prepared in step (1) according to the corresponding weight parts, and stir at 3000r / min for 1-2 hours.

[0037] (3) Add the corresponding amount of thickener by weight, stir at 600 r / min for 8-10 min to obtain graphene / MXene basic slurry for later use;

[0038] II. Composite Functional Slurry:

[0039] (4) Add silica aerogel powder and hollow glass microspheres to the graphene / MXene base slurry prepared in step (3) according to the corresponding weight parts, stir thoroughly to obtain composite functional slurry;

[0040] III. Foaming:

[0041] (5) Transfer the composite functional slurry obtained in step (4) to the foaming equipment;

[0042] (6) Add the foaming agent, foam stabilizer and dispersant to the foaming equipment in the corresponding weight parts in sequence, and stir evenly;

[0043] (7) Turn on the foaming equipment and foam at 20-30℃ to obtain infrared stealth coating slurry.

[0044] The present application will be specifically described below through specific embodiments. The following embodiments are only some embodiments of the present application and are not intended to limit the present application.

[0045] Example 1

[0046] A method for preparing an infrared stealth coating slurry, the infrared stealth coating slurry being composed of the following components in parts by weight: 80 parts of aqueous polyurethane emulsion; 10 parts of graphene powder; 15 parts of MXene dispersion; 10 parts of silica aerogel powder; 20 parts of hollow glass microspheres; 1 part of thickener; 5 parts of binder; 8 parts of foaming agent; 15 parts of foam stabilizer; 3 parts of dispersant; and 30 parts of softened water.

[0047] The density of the hollow glass microspheres is 0.4 g / cm³. 3 The particle size is 100 μm. The concentration of the MXene dispersion is 20 mg / mL. The particle size of the silica aerogel powder is 300 μm, the density is 0.25 g / mL, and the porosity is 95%. The thickener is any one of polyvinyl alcohol, polyacrylates, or cellulose derivatives, and the binder is epoxy resin or silane-modified acrylic resin. The foaming agent is alkylbenzene sulfonate, the foam stabilizer is silicone polyether emulsion, and the dispersant is any one of polyacrylates, cellulose derivatives, or triethylhexylphosphoric acid. The infrared stealth coating slurry also includes a low infrared emissivity powder, which is aluminum-doped zinc oxide, added at a rate of 10 parts.

[0048] The preparation method includes the following steps:

[0049] I. Graphene / MXene base slurry

[0050] (1) A certain amount of graphene powder was added to softened water, and after wet ball milling, ultrasonic treatment and centrifugation, a graphene dispersion with a concentration of 20wt% was prepared for use.

[0051] (2) Add the waterborne polyurethane emulsion, MXene dispersion and adhesive to the graphene dispersion prepared in step (1) according to the corresponding weight parts, and stir at 3000r / min for 1-2 hours.

[0052] (3) Add the corresponding amount of thickener by weight, stir at 600 r / min for 8-10 min to obtain graphene / MXene basic slurry for later use;

[0053] II. Composite Functional Slurry:

[0054] (4) Add silica aerogel powder and hollow glass microspheres to the graphene / MXene base slurry prepared in step (3) according to the corresponding weight parts, and at the same time add 10 parts of aluminum-doped zinc oxide, stir thoroughly and evenly to obtain composite functional slurry.

[0055] III. Foaming:

[0056] (5) Transfer the composite functional slurry obtained in step (4) to the foaming equipment;

[0057] (6) Add the foaming agent, foam stabilizer and dispersant to the foaming equipment in the corresponding weight parts in sequence, and stir evenly;

[0058] (7) Turn on the foaming equipment and foam at 20-30℃ to obtain infrared stealth coating slurry.

[0059] Example 2

[0060] A method for preparing an infrared stealth coating slurry, the infrared stealth coating slurry being composed of the following components in parts by weight: 100 parts of aqueous polyurethane emulsion; 12 parts of graphene powder; 18 parts of MXene dispersion; 13 parts of silica aerogel powder; 25 parts of hollow glass microspheres; 1.5 parts of thickener; 8 parts of binder; 10 parts of foaming agent; 16 parts of foam stabilizer; 4 parts of dispersant; and 35 parts of softened water.

[0061] The density of the hollow glass microspheres is 0.3 g / cm³. 3 The particle size is 70 μm. The concentration of the MXene dispersion is 20 mg / mL. The particle size of the silica aerogel powder is 210 μm, the density is 0.18 g / mL, and the porosity is 88%. The thickener is any one of polyvinyl alcohol, polyacrylates, or cellulose derivatives, and the binder is epoxy resin or silane-modified acrylic resin. The foaming agent is alkylbenzene sulfonate, the foam stabilizer is silicone polyether emulsion, and the dispersant is any one of polyacrylates, cellulose derivatives, or triethylhexylphosphoric acid. The infrared stealth coating slurry also includes a low infrared emissivity powder, which is aluminum-doped zinc oxide, added at 15 parts.

[0062] The preparation method includes the following steps:

[0063] I. Graphene / MXene base slurry

[0064] (1) A certain amount of graphene powder was added to softened water, and after wet ball milling, ultrasonic treatment and centrifugation, a graphene dispersion with a concentration of 20wt% was prepared for use.

[0065] (2) Add the waterborne polyurethane emulsion, MXene dispersion and adhesive to the graphene dispersion prepared in step (1) according to the corresponding weight parts, and stir at 3000r / min for 1-2 hours.

[0066] (3) Add the corresponding amount of thickener by weight, stir at 600 r / min for 8-10 min to obtain graphene / MXene basic slurry for later use;

[0067] II. Composite Functional Slurry:

[0068] (4) Add silica aerogel powder and hollow glass microspheres to the graphene / MXene base slurry prepared in step (3) according to the corresponding weight parts, and at the same time add 15 parts of aluminum-doped zinc oxide, stir thoroughly and evenly to obtain composite functional slurry.

[0069] III. Foaming:

[0070] (5) Transfer the composite functional slurry obtained in step (4) to the foaming equipment;

[0071] (6) Add the foaming agent, foam stabilizer and dispersant to the foaming equipment in the corresponding weight parts in sequence, and stir evenly;

[0072] (7) Turn on the foaming equipment and foam at 20-30℃ to obtain infrared stealth coating slurry.

[0073] Example 3

[0074] A method for preparing an infrared stealth coating slurry, the infrared stealth coating slurry being composed of the following components in parts by weight: 120 parts of aqueous polyurethane emulsion; 15 parts of graphene powder; 20 parts of MXene dispersion; 15 parts of silica aerogel powder; 30 parts of hollow glass microspheres; 2 parts of thickener; 10 parts of binder; 12 parts of foaming agent; 18 parts of foam stabilizer; 5 parts of dispersant; and 40 parts of softened water.

[0075] The density of the hollow glass microspheres is 0.2 g / cm³. 3 The particle size is 40 μm. The concentration of the MXene dispersion is 20 mg / mL. The particle size of the silica aerogel powder is 120 μm, the density is 0.12 g / mL, and the porosity is 80%. The thickener is any one of polyvinyl alcohol, polyacrylates, or cellulose derivatives, and the binder is epoxy resin or silane-modified acrylic resin. The foaming agent is alkylbenzene sulfonate, the foam stabilizer is silicone polyether emulsion, and the dispersant is any one of polyacrylates, cellulose derivatives, or triethylhexylphosphoric acid. The infrared stealth coating slurry also includes a low infrared emissivity powder, which is aluminum-doped zinc oxide, added at a rate of 20 parts.

[0076] The preparation method includes the following steps:

[0077] I. Graphene / MXene base slurry

[0078] (1) A certain amount of graphene powder was added to softened water, and after wet ball milling, ultrasonic treatment and centrifugation, a graphene dispersion with a concentration of 20wt% was prepared for use.

[0079] (2) Add the waterborne polyurethane emulsion, MXene dispersion and adhesive to the graphene dispersion prepared in step (1) according to the corresponding weight parts, and stir at 3000r / min for 1-2 hours.

[0080] (3) Add the corresponding amount of thickener by weight, stir at 600 r / min for 8-10 min to obtain graphene / MXene basic slurry for later use;

[0081] II. Composite Functional Slurry:

[0082] (4) Add silica aerogel powder and hollow glass microspheres to the graphene / MXene base slurry prepared in step (3) according to the corresponding weight parts, and at the same time add 20 parts of aluminum-doped zinc oxide, stir thoroughly and evenly to obtain composite functional slurry.

[0083] III. Foaming:

[0084] (5) Transfer the composite functional slurry obtained in step (4) to the foaming equipment;

[0085] (6) Add the foaming agent, foam stabilizer and dispersant to the foaming equipment in the corresponding weight parts in sequence, and stir evenly;

[0086] (7) Turn on the foaming equipment and foam at 20-30℃ to obtain infrared stealth coating slurry.

[0087] As is well known, foam coating has many advantages, including saving chemicals, saving energy, reducing processing costs, and providing uniform coating with easy control over the coating amount. Furthermore, when coating the back of a fabric, the tiny air bubbles thicken the coating liquid, preventing it from penetrating to the front of the fabric and affecting its appearance. This also gives the foam-coated fabric a softer hand feel. It can be used for single-sided or double-sided processing of thick fabrics and fabrics with surface structures. Therefore, the coating slurry of this invention forms a large number of porous structures after foaming, and the air trapped within these porous structures plays a role in preventing heat dissipation.

[0088] This invention combines silica aerogel powder with a foamed coating slurry. Utilizing the porous, three-dimensional structure of the foamed material, it effectively and uniformly encapsulates and fixes most of the aerogel functional powder within the coating slurry. The resulting coated fabric primarily consists of polyurethane-encapsulated aerogel powder material. This maintains the thermal insulation properties of aerogel while possessing the excellent elongation properties of polyurethane itself. This results in a soft and comfortable feel to the entire coated fabric without silica aerogel shedding, ensuring normal wearability and durability of the garment. It also guarantees the durability of infrared stealth fabrics. Furthermore, it solves the problem that traditional methods of directly loading aerogel onto textile surfaces often require large amounts of adhesives, thickeners, and film-forming agents to prevent aerogel powder shedding, severely impacting the flexibility, breathability, and functionality of textiles.

[0089] Simultaneously, functional hollow glass microspheres are introduced and combined with the foamed coating slurry. Because hollow microspheres, as thermal insulation materials, possess ultra-micropore, hollow, or multi-layered structures, they exhibit very low thermal conductivity and water absorption. Using them as fillers can significantly reduce heat conduction, thereby effectively reducing the infrared radiation energy of the target. These microspheres form a hollow gas layer with the substrate surface, blocking heat conduction. Due to their honeycomb hollow structure and low thermal conductivity, the coating has excellent thermal insulation properties. Furthermore, the hollow glass microspheres can reflect and block more than 85% of the sun's heat onto the substrate surface. This achieves the goal of preventing rapid heat dissipation from the coated fabric, thus effectively improving infrared stealth performance. This invention selects hollow glass microspheres with a relatively medium to large density and particle size, resulting in a larger diameter of the numerous porous structures formed inside the foamed layer, a more porous internal structure, greater air retention, and increased air permeability of the coating slurry.

[0090] The graphene foam dispersion ensures that graphene and MXene are partially exposed, which also helps graphene to adhere firmly to the fabric surface, effectively reducing electrons on the fabric surface and improving low infrared emissivity performance. Furthermore, most of the graphene and MXene are encapsulated within the slurry surface, ensuring the durability of the infrared stealth effect.

[0091] In summary, the infrared stealth coating slurry prepared by combining foaming theory with graphene powder, MXene dispersion, silica aerogel powder, and hollow glass microspheres exhibits a mid-infrared emissivity of only 0.248 in the 8-14 μm band for use in infrared stealth fabrics. Furthermore, it reduces the surface temperature by more than 53 °C on a 100 °C heating stage (surface radiation temperature of 95 °C). This far-infrared stealth coating slurry is simple to prepare for fabrics, offers diverse functions, and has wide applicability, showing promising prospects in military and smart wearable materials fields.

[0092] Of course, the above description is not intended to limit the present invention, and the present invention is not limited to the examples given above. Any changes, modifications, additions or substitutions made by those skilled in the art within the scope of the present invention should be protected by the present invention.

Claims

1. A method for preparing an infrared stealth coating slurry, characterized in that, The infrared stealth coating paste is composed of the following components in parts by weight: 80-120 parts of waterborne polyurethane emulsion 10-15 parts of graphene powder; 15-20 parts of MXene dispersion; 10-15 parts of silica aerogel powder; 20-30 parts of hollow glass microspheres; Thickener 1-2 parts; 5-10 parts of adhesive; 8-12 parts of foaming agent; 15-18 parts of foam stabilizer; 3-5 parts dispersant; 30-40 parts softened water; The density of the hollow glass microspheres is 0.2-0.4 g / cm³. 3 The particle size is 40-100 μm; the concentration of MXene dispersion is 20 mg / mL; the infrared stealth coating slurry also includes low infrared emissivity powder, which is aluminum-doped zinc oxide, and the addition amount is 10-20 parts; the binder is epoxy resin or silane-modified acrylic resin. The preparation of the infrared stealth coating slurry includes the following steps: I. Graphene / MXene base slurry (1) Add graphene powder to softened water, and then process it by wet ball milling, ultrasonication and centrifugation to obtain a graphene dispersion with a concentration of 20wt% for later use. (2) Add the waterborne polyurethane emulsion, MXene dispersion and adhesive to the graphene dispersion prepared in step (1) according to the corresponding weight parts, and stir at 3000 r / min for 1-2 hours. (3) Add the corresponding amount of thickener by weight, stir at 600 r / min for 8-10 min to obtain graphene / MXene basic slurry for later use; II. Composite Functional Slurry: (4) Add silica aerogel powder and hollow glass microspheres to the graphene / MXene base slurry prepared in step (3) according to the corresponding weight parts, and add 10-20 parts of low infrared emissivity powder at the same time. Stir thoroughly to obtain composite functional slurry. III. Foaming: (5) Transfer the composite functional slurry obtained in step (4) to the foaming equipment; (6) Add the foaming agent, foam stabilizer and dispersant to the foaming equipment in the corresponding weight parts in sequence, and stir evenly; (7) Turn on the foaming equipment and foam at 20-30℃ to obtain infrared stealth coating slurry.

2. The method for preparing the infrared stealth coating slurry according to claim 1, characterized in that: The particle size of silica aerogel powder is 120μm-300μm, the density is 0.12g / mL-0.25g / mL, and the porosity is 80-95%.

3. The method for preparing the infrared stealth coating slurry according to claim 1, characterized in that: The thickener is any one of polyvinyl alcohol, polyacrylates, and cellulose derivatives.

4. The method for preparing the infrared stealth coating slurry according to claim 1, characterized in that: The foaming agent is alkylbenzene sulfonate, the foam stabilizer is silicone polyether emulsion, and the dispersant is any one of polyacrylates, cellulose derivatives, and triethylhexyl phosphate.

Images