Aging-resistant, high-reflective, high-emissive textile screen printing coating and method of making

Abstract

The application discloses an anti-aging, high-reflecting and high-emitting fabric screen printing coating, which is composed of 30 parts of rare earth slurry, 40 parts of polyurethane resin, 5-10 parts of additives and 20-30 parts of water in terms of weight; the rare earth slurry is composed of 10-15 parts of aluminum oxide, 10-15 parts of barium oxide, 25-36 parts of niobium oxide, 13-20 parts of rare earth oxide and 16-35 parts of titanium oxide in terms of weight. The white fabric dye is green and environment-friendly, is coated on the surface of the fabric, and can reduce the temperature by more than 4 DEG C during the day.

Description

Technical Field

[0001] This invention relates to the field of coating materials technology, specifically to an aging-resistant, high-reflectivity, high-emissivity fabric screen printing coating and its preparation method. Background Technology

[0002] With the improvement of living standards, people's demand for functional fabrics is increasing day by day. Fabrics with thermal management functions are gradually gaining popularity in the market. The human body's own heat dissipation methods are mainly divided into three types: evaporative heat dissipation, thermal radiation, and thermal conduction. Below 25 degrees Celsius, the human body mainly dissipates heat through radiation, supplemented by the evaporation of sweat, while thermal conduction accounts for less than 10%. Therefore, improving the thermal radiation heat dissipation performance of fabrics plays an important role in improving the comfort of clothing.

[0003] However, in actual outdoor use, clothing also faces the challenges of sunlight and energy input from the surrounding environment. This energy input leads to an increase in body temperature and a greater need for heat dissipation. Therefore, clothing thermal management requires it to also have high solar reflectivity.

[0004] Based on this, radiative cooling is an emerging heat dissipation technology in recent years. When dyes with radiative cooling properties are used in fabrics, the fabric surface can simultaneously possess high solar reflectivity and high atmospheric window emission performance. When people are outdoors, the high solar reflectivity reduces the amount of solar energy incident, decreasing external energy input, while the high "atmospheric window" emission effect allows heat generated during body movement to be emitted into outer space in the form of 8-13 micrometer thermal radiation, achieving a cooling effect. When wearing fabrics with radiative cooling properties, by improving the heat dissipation efficiency of the human skin, not only can comfort be improved during competitive sports, but energy utilization efficiency can also be optimized, reducing physical exertion due to perspiration and water evaporation, thereby better enhancing athletic performance.

[0005] Therefore, the present invention aims to develop a white dye for screen printing of fabrics that is resistant to aging, highly reflective, and highly emissive. When applied to the surface of clothing, it can endow the fabric with radiative cooling function and improve wearing comfort. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide a fabric screen printing coating and its preparation method, so as to achieve at least the effects of aging resistance, high reflectivity, and high emissivity.

[0007] The objective of this invention is achieved through the following technical solution:

[0008] A screen printing coating for aging-resistant, high-reflectivity, and high-emissivity fabrics:

[0009] By weight, the coating is composed of 30 parts rare earth slurry, 40 parts polyurethane resin, 5-10 parts additives and 20-30 parts water;

[0010] By weight, the rare earth slurry is composed of 10-15 parts of alumina, 10-15 parts of barium oxide, 25-36 parts of niobium oxide, 13-20 parts of rare earth oxides and 16-35 parts of titanium oxide.

[0011] Furthermore, the rare earth oxides include lanthanum oxide and cerium oxide;

[0012] The additives include leveling agents and defoamers.

[0013] Furthermore, the method for preparing the coating includes the following steps:

[0014] S1: The aluminum oxide, niobium oxide, barium oxide, rare earth oxides and titanium oxide are mixed and then pulverized;

[0015] S2: The pulverized powder is sintered at high temperature, and then the sintered molten liquid is quenched in cold water to obtain coarse product powder.

[0016] S3: The coarse product powder is added to a solvent and ground to obtain A1 slurry with a particle size of 15-25μm, A2 slurry with a particle size of 5-10μm, and A3 slurry with a particle size of 0.3-0.7μm, respectively.

[0017] S4: Take another coarse product powder, add water and grind it, then perform atomization drying, and perform a second sintering at high temperature. The resulting powder is dispersed in a solvent to obtain A4 slurry.

[0018] S5: Mix the A1 slurry, A2 slurry, A3 slurry and A4 slurry to obtain rare earth slurry;

[0019] S6: Mix the rare earth slurry, polyurethane resin, additives and water to obtain the final product.

[0020] Furthermore, in step S2, the particle size of the pulverized powder is 30-40 mesh.

[0021] Furthermore, in step S2, the temperature of the first sintering is 360-1400℃;

[0022] And / or, the first sintering time is 4-4.5 hours.

[0023] Furthermore, in step S3, the granularity is the median granularity.

[0024] Furthermore, in step S4, the particle size of the coarse product powder after grinding is 1-5 μm.

[0025] Furthermore, in step S4, the temperature of the second sintering is 1230-1250℃;

[0026] And / or, the second sintering time is 30-50 min.

[0027] Furthermore, the weight ratio of the A1 slurry, A2 slurry, A3 slurry and A4 slurry is 1:0.8-1.3:0.4-0.6:0.1-0.2.

[0028] Furthermore, in steps S4 and S5, the solvent includes water or butyl acetate;

[0029] And / or, the solid content of the A1 slurry, A2 slurry, A3 slurry and A4 slurry is 30-40%.

[0030] It is worth noting that the filler material used in this patent is an amorphous material with a high refractive index. The advantage of amorphous materials is that all materials have uniform properties, including refractive index, band gap, and emissivity. In the prior art, fillers with different functions are usually mixed as fillers. However, in practice, the concentrations of different functional fillers are diluted with each other, resulting in a trade-off in their performance.

[0031] In the actual preparation of amorphous materials, the content of each component is not arbitrarily matched. Only when the components are distributed in a certain proportion can a uniform amorphous structure be formed; otherwise, second-phase segregation and other results may occur. In practice, the most direct detection method is to take a small amount of the molten liquid and pour it directly onto the surface of an iron plate after the raw materials have melted into a homogeneous solution, allowing it to cool naturally in the air, and then observing whether the cooled droplet sample is as transparent as glass. Although amorphous materials with uniform properties can be obtained by adjusting the formula using alumina, niobium oxide, and rare earth oxides as the main raw materials, the refractive index of such materials is only about 1.8-2, which is relatively low. In this invention, barium and titanium elements are introduced into the system, which can further increase the refractive index while maintaining a high band gap. We have successfully obtained a uniform amorphous material with a high refractive index through in-depth control of the formula ratio.

[0032] The beneficial effects of this invention are:

[0033] 1. The amorphous filler of this invention contains the additional addition of titanium, which has two advantages: Firstly, the addition of titanium can further increase the refractive index of the material, thereby improving the reflective effect. Secondly, titanium dioxide, due to its excellent ultraviolet absorption properties, can improve the aging resistance and yellowing resistance of clothing.

[0034] 2. The dye raw materials of this invention have low cost, high window emissivity, and high reflectivity. The dye of this invention has a solar reflectivity of 90%, an emissivity of 0.95, and a heat dissipation power of 120W / m at room temperature. 2 above.

[0035] 3. The dye for white fabrics of the present invention is green and environmentally friendly. When applied to the surface of the fabric, it can reduce the temperature by more than 4°C during the day. Attached Figure Description

[0036] Figure 1 The results of the reflectivity test of the radiation-cooled clothing in the example are shown.

[0037] Figure 2 This example compares the temperature changes of dyed and undyed clothing within one day.

[0038] Figure 3 These are photographs of the precursor samples from Example 1 and Comparative Example 1 after natural cooling. Detailed Implementation

[0039] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings, but the scope of protection of the present invention is not limited to the following description.

[0040] Example 1

[0041] Take 10 parts of aluminum oxide, 12 parts of barium oxide, 26 parts of niobium oxide, 16 parts of lanthanum oxide, and 30 parts of titanium oxide.

[0042] After thoroughly mixing these raw materials, a certain amount of water was added and wet-milled in a planetary ball mill at a speed of 400 rpm for 12 hours. The ratio of large, medium, and small balls was 3:4:3, and the volume ratio of air, liquid, and balls in the mill chamber was controlled at 1:1:1. After grinding, the grinding beads were filtered through a 40-mesh sieve to obtain a coarse slurry. The coarse slurry was thoroughly dried in a 90-degree oven to obtain a precursor sample that had agglomerated into lumps. The lumpy precursor sample was then ground again in a powder crusher to obtain a uniformly mixed precursor powder. This precursor powder was placed in a corundum crucible and heated in a furnace with a melting point at a rate of 5 degrees per minute from room temperature to 1400 degrees Celsius, and held at that temperature for 4 hours. The liquid was then directly poured into water for cold quenching, and the powder was filtered from the water to obtain coarse powder.

[0043] Prepare 10 kg of a 40% coarse powder solution, with a dispersant content of 12-15% (BYK111 type dispersant) and water as the solvent. Place the solution in a sand mill at 1500-1600 rpm, using 0.5 mm grinding balls. Measure the slurry particle size every 15 minutes using a laser particle size analyzer, obtaining slurry A1 with a D50 of 19.5 μm, slurry A2 with a D50 of 4.2 μm, and slurry A3 with a D50 of 0.63 μm. Mix the three slurries in a mass ratio of A1:A2:A3 = 1:1:0.5:0.15 to obtain the final finished slurry.

[0044] A small amount of precursor powder was placed in a corundum crucible and heated in a furnace with a melting capacity. The temperature was increased from room temperature to 1400 degrees Celsius at a rate of 5 degrees Celsius per minute and maintained at this temperature for 4 hours. The hot liquid was then poured onto the surface of a 300x300x50 mm stainless steel plate. The resulting droplet was allowed to cool naturally in air. (The image shows the resulting product.) Figure 3 As shown above, the sample exhibits a uniform amorphous state.

[0045] Take 30 parts of the above-mentioned radiation cooling slurry, 15 parts of dispersant DM-1501 from Shanghai ANOKY Co., Ltd., 30 parts of waterborne polyurethane resin, 65 parts of nonionic formaldehyde-free crosslinking agent DM-892 from Shanghai ANOKY Co., Ltd., 2 parts of fastness modifier DM-2582N from Shanghai ANOKY Co., Ltd., 2 parts of general leveling agent, 1 part of defoamer, and 25 parts of water. Mix them evenly to obtain the finished white coating. Apply it to the surface of artificial cotton fabric by screen printing to a thickness of 35μm with a screen mesh of 330 mesh. The surface layer has an average solar reflectance of 90%, an emissivity of 0.95, and a heat dissipation power of 122W / m2 at room temperature. Compared with undyed clothing, it cools down by more than 4 degrees Celsius during the day.

[0046] Example 2

[0047] Take 15 parts of aluminum oxide, 15 parts of barium oxide, 36 parts of niobium oxide, 20 parts of lanthanum oxide, and 16 parts of titanium oxide.

[0048] After thoroughly mixing these raw materials, a certain amount of water was added and wet-milled in a planetary ball mill at a speed of 400 rpm for 12 hours. The ratio of large, medium, and small balls was 3:4:3, and the volume ratio of air, liquid, and balls in the mill chamber was controlled at 1:1:1. After grinding, the grinding beads were filtered through a 40-mesh sieve to obtain a coarse slurry. The coarse slurry was thoroughly dried in a 90-degree oven to obtain a precursor sample that had agglomerated into lumps. The lumpy precursor sample was then ground again in a powder crusher to obtain a uniformly mixed precursor powder. This precursor powder was placed in a corundum crucible and heated in a furnace with a melting point at a rate of 5 degrees per minute from room temperature to 1400 degrees Celsius, and held at that temperature for 4 hours. The liquid was then directly poured into water for cold quenching, and the powder was filtered from the water to obtain coarse powder.

[0049] Prepare 10 kg of a 40% coarse powder solution, with a dispersant content of 12-15% (BYK111 type dispersant) and water as the solvent. Place the solution in a sand mill at 1500-1600 rpm, using 0.5 mm grinding balls. Measure the slurry particle size every 15 minutes using a laser particle size analyzer, obtaining slurry A1 with a D50 of 19.5 μm, slurry A2 with a D50 of 4.2 μm, and slurry A3 with a D50 of 0.63 μm. Mix the three slurries in a mass ratio of A1:A2:A3 = 1:1:0.5:0.15 to obtain the final finished slurry.

[0050] Take 30 parts of the above-mentioned radiation cooling slurry, 15 parts of dispersant DM-1501 from Shanghai ANOKY Co., Ltd., 30 parts of waterborne polyurethane resin, 65 parts of nonionic formaldehyde-free crosslinking agent DM-892 from Shanghai ANOKY Co., Ltd., 2 parts of fastness modifier DM-2582N from Shanghai ANOKY Co., Ltd., 2 parts of general leveling agent, 1 part of defoamer, and 25 parts of water. Mix them evenly to obtain the finished white coating. Apply it to the surface of artificial cotton fabric by screen printing to a thickness of 35μm with a screen mesh of 330 mesh. The surface layer has an average solar reflectance of 90%, an emissivity of 0.95, and a heat dissipation power of 122W / m2 at room temperature. Compared with undyed clothing, it cools down by more than 4 degrees Celsius during the day.

[0051] Comparative Example 1

[0052] Take 20 parts of aluminum oxide, 20 parts of barium oxide, 35 parts of niobium oxide, 10 parts of lanthanum oxide, and 55 parts of titanium oxide.

[0053] After thoroughly mixing these raw materials, a certain amount of water was added and wet-milled in a planetary ball mill at a speed of 400 rpm for 12 hours. The ratio of large, medium, and small balls was 3:4:3, and the volume ratio of air, liquid, and balls in the mill chamber was controlled at 1:1:1. After grinding, the grinding beads were filtered through a 40-mesh sieve to obtain a coarse slurry. The coarse slurry was thoroughly dried in a 90-degree oven to obtain a precursor sample that had agglomerated into lumps. The lumpy precursor sample was then ground again in a powder crusher to obtain a uniformly mixed precursor powder. This precursor powder was placed in a corundum crucible and heated in a furnace with a melting furnace at a heating rate of 5 degrees per minute from room temperature to 1400 degrees Celsius, and held at that temperature for 4 hours. A small amount of the liquid was then poured onto the surface of a 300x300x50 mm stainless steel plate while still hot. The resulting droplet was allowed to cool naturally in air. (Image of the obtained sample is shown.) Figure 3 As shown below, crystallization occurs inside the sample.

[0054] It can be seen that if the proportions of each ingredient exceed the range defined in this invention, crystallization will occur inside the precursor material. Coarse powder with crystallization is not suitable for preparing radiation cooling materials because it will reduce the refractive properties of the material.

[0055] Take the samples described in Example 1 and Comparative Example 1 (i.e., the attached samples) Figure 3 Left and attached Figure 3 The samples on the right were tested using an ellipsometer to measure their refractive index. The results showed that the refractive index of the samples in Example 1 was 2.4, while the refractive index of the samples in Comparative Example 2 was 2.0.

[0056] Comparative Example 2

[0057] Take 20 parts of aluminum oxide, 20 parts of barium oxide, 35 parts of niobium oxide, 10 parts of lanthanum oxide, and 55 parts of titanium oxide.

[0058] After thoroughly mixing these raw materials, a certain amount of water was added and wet-milled in a planetary ball mill at a speed of 400 rpm for 12 hours. The ratio of large, medium, and small balls was 3:4:3, and the volume ratio of air, liquid, and balls in the mill chamber was controlled at 1:1:1. After grinding, the grinding beads were filtered through a 40-mesh sieve to obtain a coarse slurry. The coarse slurry was thoroughly dried in a 90-degree oven to obtain a precursor sample that had agglomerated into lumps. The lumpy precursor sample was then ground again in a powder crusher to obtain a uniformly mixed precursor powder. This precursor powder was placed in a corundum crucible and heated in a furnace with a melting point at a rate of 5 degrees per minute from room temperature to 1400 degrees Celsius, and held at that temperature for 4 hours. The liquid was then directly poured into water for cold quenching, and the powder was filtered from the water to obtain coarse powder.

[0059] Prepare 10 kg of a 40% coarse powder solution, with a dispersant content of 12-15% (BYK111 type dispersant) and water as the solvent. Place the solution in a sand mill at 1500-1600 rpm, using 0.5 mm grinding balls. Measure the slurry particle size every 15 minutes using a laser particle size analyzer, obtaining slurry A1 with a D50 of 19.5 μm, slurry A2 with a D50 of 4.2 μm, and slurry A3 with a D50 of 0.63 μm. Mix the three slurries in a mass ratio of A1:A2:A3 = 1:1:0.5:0.15 to obtain the final finished slurry.

[0060] Take 30 parts of the above-mentioned radiation cooling slurry, 15 parts of dispersant DM-1501 from Shanghai ANOKY Co., Ltd., 30 parts of waterborne polyurethane resin, 65 parts of nonionic formaldehyde-free crosslinking agent DM-892 from Shanghai ANOKY Co., Ltd., 2 parts of fastness modifier DM-2582N from Shanghai ANOKY Co., Ltd., 2 parts of general leveling agent, 1 part of defoamer, and 25 parts of water. Mix them evenly to obtain the finished white coating. Apply it to the surface of artificial cotton fabric by screen printing to a thickness of 35μm with a screen mesh of 330 mesh. The surface layer has a solar reflectivity of 82%, an emissivity of 0.76, and a heat dissipation power of 87W / m2 at room temperature. Compared with undyed clothing, it cools down by more than 2.5°C during the day.

[0061] The above description is merely a preferred embodiment of the present invention. It should be understood that the present invention is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and environments, and can be altered within the scope of the concept described herein through the above teachings or related technologies or knowledge. Modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present invention should be within the protection scope of the appended claims.

Claims

1. A screen printing coating for aging-resistant, high-reflectivity, and high-emissivity fabrics, characterized in that: By weight, the coating is composed of 30 parts rare earth slurry, 40 parts polyurethane resin, 5-10 parts additives and 20-30 parts water; The method for preparing the coating includes the following steps: S1: Mix aluminum oxide, niobium oxide, barium oxide, rare earth oxides and titanium oxide and then pulverize them; S2: The pulverized powder is sintered at high temperature, and then the sintered molten liquid is quenched in cold water to obtain coarse product powder. The temperature of the first sintering is 360-1400℃; and / or the time of the first sintering is 4-4.5 h; S3: The coarse product powder is added to a solvent and ground to obtain A1 slurry with a particle size of 15-25 μm, A2 slurry with a particle size of 5-10 μm, and A3 slurry with a particle size of 0.3-0.7 μm, respectively. S4: Take another coarse product powder, add water and grind it, then perform atomization drying, and perform a second sintering at high temperature. The resulting powder is dispersed in a solvent to obtain A4 slurry. The second sintering temperature is 1230-1250℃; and / or the second sintering time is 30-50 min; S5: Mix the A1 slurry, A2 slurry, A3 slurry, A4 slurry and solvent to obtain the rare earth slurry; The weight ratio of A1 slurry, A2 slurry, A3 slurry, and A4 slurry is 1:0.8-1.3:0.4-0.6:0.1-0.2; The solid content of the A1 slurry, A2 slurry, A3 slurry, and A4 slurry is 30-40%. S6: Mix the rare earth slurry, polyurethane resin, additives and water to obtain the final product; By weight, the rare earth slurry is composed of 10-15 parts of alumina, 10-15 parts of barium oxide, 25-36 parts of niobium oxide, 13-20 parts of rare earth oxides and 16-35 parts of titanium oxide.

2. The coating according to claim 1, characterized in that: The rare earth oxides include lanthanum oxide and cerium oxide; the additives include leveling agents and defoamers.

3. The preparation method according to claim 1, characterized in that: In step S2, the particle size of the pulverized powder is 30-40 mesh.

4. The preparation method according to claim 1, characterized in that: In step S3, the granularity is the median granularity.

5. The preparation method according to claim 1, characterized in that: In step S4, the particle size of the coarse product powder after grinding is 1-5 μm.

6. The preparation method according to claim 1, characterized in that: In steps S4 and S5, the solvent includes water or butyl acetate.

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