Strong-stain-resistance radiation refrigeration coating and preparation method thereof

Abstract

The invention discloses a strong-stain-resistant radiation refrigeration coating and a preparation method thereof, and relates to the field of radiation refrigeration, in particular to the strong-stain-resistant radiation refrigeration coating and the preparation method thereof. The invention aims to solve the technical problem of poor radiation refrigeration effect caused by poor weather resistance, water resistance, stain resistance and color retention of the existing radiation refrigeration coating. The radiation refrigeration coating with strong stain resistance is mainly composed of a filler and modified water-based aldehyde ketone resin. The coating prepared by the invention has strong stain resistance, stable and lasting high sunlight reflectance and atmospheric window emissivity, more importantly, the coating prepared by the invention has low surface energy after forming a film, has high water resistance and self-stain resistance, really realizes that pollutants cannot be attached, and has no pollution to the environment. The radiation refrigeration device can be applied to a relatively severe environment to realize long-term stable radiation refrigeration, and has an ideal application prospect in the fields of energy sources, aerospace and buildings with harsh requirements.

Description

Technical Field

[0001] The invention relates to the field of radiation refrigeration, and in particular to a highly stain-resistant radiation refrigeration coating and a preparation method thereof. Background Art

[0002] Radiative cooling is a method of making a high-temperature object radiate energy to the outside world to lower its temperature. It uses the principle that objects that are not in contact with each other in a vacuum environment can exchange radiation heat with each other due to the difference in temperature to cool down the high-temperature object. The outer space is an ultra-low temperature and ultra-vacuum environment, so the instruments on the spacecraft can use radiative cooling to achieve the cooling effect. The existing radiative cooling coatings will continue to decline in radiative cooling capacity over time and with the continuous invasion of pollutants, especially in highly polluted and dusty environments. These problems are more obvious, and the surface of the coating is invaded by pollutants and cannot "self-clean", which further accelerates the loss of radiative cooling effect and even fails to meet actual requirements. Most of the existing radiative cooling coatings are adjusted based on the concept of traditional architectural coatings, and have problems such as weather resistance, water resistance, stain resistance, and poor color retention, which leads to poor radiative cooling effect. Summary of the invention

[0003] The present invention aims to solve the technical problem that the existing radiation cooling coating has poor weather resistance, water resistance, stain resistance and color retention, thus causing poor radiation cooling effect, and provides a highly stain-resistant radiation cooling coating and a preparation method thereof.

[0004] The highly anti-fouling radiation refrigeration coating of the present invention is composed of the following components by weight: 12-23 parts of deionized water, 16-35 parts of a first filler, 6-15 parts of a second filler, 24-37 parts of a modified water-based aldehyde-ketone resin and 5-10 parts of a comprehensive auxiliary agent.

[0005] Preferably, the first filler is attapulgite;

[0006] Preferably, the filled attapulgite is composed of 5 to 10 parts of attapulgite, 11 to 25 parts of titanium dioxide and 0 to 25 parts of lithopone by weight;

[0007] Preferably, the second filler is modified chitosan;

[0008] Preferably, the modified chitosan is composed of 2 to 8 parts of chitosan, 4 to 7 parts of barium sulfate and 0 to 7 parts of zinc oxide in parts by weight;

[0009] Preferably, the modified water-based aldehyde-ketone resin is composed of 6 to 11 parts of water-based aldehyde-ketone resin and 0 to 26 parts of modifier by weight;

[0010] Preferably, the modifier is polyurethane, water-based acrylic resin or epoxy resin;

[0011] Preferably, the comprehensive auxiliary agent is polyether-modified polysiloxane, which has the functions of emulsification, defoaming, wetting, dispersing and leveling.

[0012] The preparation method of the highly anti-fouling radiation refrigeration coating of the present invention is carried out according to the following steps:

[0013] 1. Weigh the raw materials according to the above weight parts;

[0014] 2. Preparation of the first filler premix: put 1 / 5 to 1 / 3 of the comprehensive auxiliary agent weighed in step 1 into 1 / 4 to 1 / 3 of the deionized water weighed in step 1, stir at a speed of 150 to 350 rpm for 3 to 6 min, then adjust the speed to 450 to 650 rpm, add all the attapulgite weighed in step 1 and stir for 10 to 15 min, then add all the titanium dioxide and lithopone weighed in step 1 in sequence, adjust the speed to 800 to 950 rpm after the addition is completed, and stir for 15 to 30 min to obtain the first filler premix;

[0015] 3. Preparation of the second filler dispersion: 1 / 8 to 1 / 5 of the comprehensive auxiliary agent weighed in step 1 is put into 1 / 4 to 1 / 3 of the deionized water weighed in step 1, and all the chitosan weighed in step 1 is slowly added, and the mixture is stirred and dispersed at a speed of 200 to 400 rpm at room temperature for 10 to 15 min, and then the mixture is heated to 60°C to 80°C and stirred and emulsified at a speed of 1000 to 1500 rpm for 15 to 45 min, and then all the zinc oxide and barium sulfate weighed in step 1 are slowly added, and the mixture is stirred and dispersed at a speed of 600 to 800 rpm at 60°C to 80°C for 10 to 20 min, and the amount of water lost in step 3 due to stirring and dispersing is determined by weighing, and then supplemented to obtain a second filler dispersion;

[0016] 4. Preparation of modified water-based aldehyde-ketone resin: At room temperature and 150 rpm to 300 rpm, add all the modifiers weighed in step 1 to 1 / 4 to 1 / 3 of the deionized water weighed in step 1, then add 1 / 4 to 1 / 3 of the comprehensive auxiliary agent weighed in step 1 and stir for 5 min to 10 min, heat to 65°C to 72°C, adjust the speed to 800 rpm to 1250 rpm and slowly add all the water-based aldehyde-ketone resin weighed in step 1, keep warm at 65°C to 72°C for 10 min to 15 min, cool to room temperature, and determine by weighing the amount of water-based aldehyde-ketone resin weighed in step 4 due to stirring and dispersion. The lost amount of water is then replenished, and 1 / 15 to 1 / 10 of the comprehensive additive weighed in step one is added; the rotation speed is adjusted to 650 rpm to 850 rpm, the first filler premix prepared in step two is added, and then the second filler dispersion prepared in step three is added, the rotation speed is adjusted to 1200 rpm to 1500 rpm and stirred for 25 min to 45 min, the rotation speed is adjusted to 650 rpm to 950 rpm, the remaining deionized water weighed in step one and the remaining comprehensive additive weighed in step one are slowly added, and then stirred for 10 min to 15 min, and the material is filtered out.

[0017] The coating of the present invention has a high and stable solar reflectance and atmospheric window emissivity, and reasonably solves the problem of pollution resistance, thereby achieving a lasting clean and continuous radiant cooling effect. The coating of the present invention has excellent weather resistance, water resistance and pollution resistance, and can truly make pollutants "not attached", thereby achieving permanent clean and continuous radiant cooling effect.

[0018] The present invention adopts a combination of multiple new fillers and pre-processes the filler combination to improve the utilization rate and synergistic effect of the filler, selects a modified water-based aldehyde-ketone resin with high purity, not prone to yellowing, and forming a three-dimensional network during the drying process as a connecting material to match the first and second functional fillers, wherein the attapulgite forms a chain frame in the first filler component after pre-mixing, which can greatly play the role of white powder, greatly improve the solar reflectivity and atmospheric window emissivity, and also has the effect of increasing the bonding strength of the coating, and the second filler treated with chitosan has good antibacterial and water-retaining effects, improves the overall stability of the coating, prevents the coating from mildewing, and assists the first filler in playing a role while improving the stain resistance. Thus, while effectively reducing the cost, the prepared coating has strong stain resistance, stable and lasting high solar reflectance and atmospheric window emissivity, and more importantly, the coating prepared by the present invention has a lower surface energy after film formation, has a higher water resistance and self-antifouling performance, truly realizes that pollutants are not attached, can be applied to a relatively harsh environment to achieve long-term and stable radiation cooling, and has ideal application prospects in demanding energy fields, aerospace fields, and construction fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is the spectrum of sunlight reflectance;

[0020] Figure 2 is the spectrum of the atmospheric window emissivity. DETAILED DESCRIPTION

[0021] Specific implementation method 1: This implementation method is a highly stain-resistant radiation refrigeration coating, which is composed of the following ingredients by weight: 12 to 23 parts of deionized water, 16 to 35 parts of a first filler, 6 to 15 parts of a second filler, 24 to 37 parts of a modified water-based aldehyde-ketone resin and 5 to 10 parts of a comprehensive additive.

[0022] Specific implementation method 2: This implementation method is different from the specific implementation method 1 in that the first filler is attapulgite. The rest is the same as the specific implementation method 1.

[0023] Specific embodiment 3: This embodiment is different from specific embodiment 2 in that the attapulgite filled is composed of 5 to 10 parts of attapulgite, 11 to 25 parts of titanium dioxide and 0 to 25 parts of lithopone by weight. The rest is the same as specific embodiment 2.

[0024] Specific embodiment 4: This embodiment differs from specific embodiment 3 in that the second filler is modified chitosan. Other aspects are the same as those of specific embodiment 3.

[0025] Specific embodiment 5: This embodiment is different from specific embodiment 4 in that the modified chitosan is composed of 2 to 8 parts of chitosan, 4 to 7 parts of barium sulfate and 0 to 7 parts of zinc oxide by weight. The rest is the same as specific embodiment 4.

[0026] Specific embodiment 6: This embodiment is different from specific embodiment 5 in that the modified water-based aldehyde-ketone resin is composed of 6 to 11 parts of water-based aldehyde-ketone resin and 0 to 26 parts of modifier by weight. The rest is the same as specific embodiment 5.

[0027] Specific embodiment 7: This embodiment is different from specific embodiment 6 in that the modifier is polyurethane, water-based acrylic resin or epoxy resin. Other aspects are the same as specific embodiment 6.

[0028] Specific embodiment 8: This embodiment is different from specific embodiment 7 in that the comprehensive auxiliary agent is polyether-modified polysiloxane. Other aspects are the same as specific embodiment 7.

[0029] Specific embodiment 9: This embodiment is a method for preparing a strong anti-fouling radiation refrigeration coating in specific embodiment 8, which is specifically carried out according to the following steps:

[0030] 1. Weigh the raw materials according to the weight parts in Specific Implementation Method 8;

[0031] 2. Preparation of the first filler premix: put 1 / 5 to 1 / 3 of the comprehensive auxiliary agent weighed in step 1 into 1 / 4 to 1 / 3 of the deionized water weighed in step 1, stir at a speed of 150 to 350 rpm for 3 to 6 min, then adjust the speed to 450 to 650 rpm, add all the attapulgite weighed in step 1 and stir for 10 to 15 min, then add all the titanium dioxide and lithopone weighed in step 1 in sequence, adjust the speed to 800 to 950 rpm after the addition is completed, and stir for 15 to 30 min to obtain the first filler premix;

[0032] 3. Preparation of the second filler dispersion: 1 / 8 to 1 / 5 of the comprehensive auxiliary agent weighed in step 1 is put into 1 / 4 to 1 / 3 of the deionized water weighed in step 1, and all the chitosan weighed in step 1 is slowly added, and the mixture is stirred and dispersed at a speed of 200 to 400 rpm at room temperature for 10 to 15 min, and then the mixture is heated to 60°C to 80°C and stirred and emulsified at a speed of 1000 to 1500 rpm for 15 to 45 min, and then all the zinc oxide and barium sulfate weighed in step 1 are slowly added, and the mixture is stirred and dispersed at a speed of 600 to 800 rpm at 60°C to 80°C for 10 to 20 min, and the amount of water lost in step 3 due to stirring and dispersing is determined by weighing, and then supplemented to obtain a second filler dispersion;

[0033] 4. Preparation of modified water-based aldehyde-ketone resin: At room temperature and 150 rpm to 300 rpm, add all the modifiers weighed in step 1 to 1 / 4 to 1 / 3 of the deionized water weighed in step 1, then add 1 / 4 to 1 / 3 of the comprehensive auxiliary agent weighed in step 1 and stir for 5 min to 10 min, heat to 65°C to 72°C, adjust the speed to 800 rpm to 1250 rpm and slowly add all the water-based aldehyde-ketone resin weighed in step 1, keep warm at 65°C to 72°C for 10 min to 15 min, cool to room temperature, and determine by weighing the amount of water-based aldehyde-ketone resin weighed in step 4 due to stirring and dispersion. The lost amount of water is then replenished, and 1 / 15 to 1 / 10 of the comprehensive additive weighed in step one is added; the rotation speed is adjusted to 650 rpm to 850 rpm, the first filler premix prepared in step two is added, and then the second filler dispersion prepared in step three is added, the rotation speed is adjusted to 1200 rpm to 1500 rpm and stirred for 25 min to 45 min, the rotation speed is adjusted to 650 rpm to 950 rpm, the remaining deionized water weighed in step one and the remaining comprehensive additive weighed in step one are slowly added, and then stirred for 10 min to 15 min, and the material is filtered out.

[0034] The present invention is verified by the following tests:

[0035] Test 1: This test is a method for preparing a highly anti-fouling radiation refrigeration coating, which is specifically carried out in the following steps:

[0036] 1. Weigh the raw materials according to the following weight proportions: 16 parts of deionized water, 27 parts of the first filler, 15 parts of the second filler, 35 parts of the modified water-based aldehyde-ketone resin and 7 parts of the comprehensive additive;

[0037] The first filler is attapulgite, which is composed of 5 parts of attapulgite and 22 parts of titanium dioxide by weight;

[0038] The second filler is modified chitosan, which is composed of 8 parts of chitosan, 4 parts of barium sulfate and 3 parts of zinc oxide by weight;

[0039] The modified water-based aldehyde-ketone resin is composed of 11 parts of water-based aldehyde-ketone resin and 24 parts of a modifier by weight; the modifier is a water-based acrylic resin;

[0040] The comprehensive auxiliary agent is polyether modified polysiloxane;

[0041] 2. Preparation of the first filler premix: put 1 / 4 of the comprehensive additive weighed in step 1 into 1 / 3 of the deionized water weighed in step 1, stir at 250 rpm for 5 min, then adjust the speed to 600 rpm, add all the attapulgite weighed in step 1 and stir for 12 min, then add all the titanium dioxide weighed in step 1 in sequence, adjust the speed to 900 rpm after the addition is completed, and stir for 20 min to obtain the first filler premix;

[0042] 3. Preparation of the second filler dispersion: 1 / 6 of the comprehensive auxiliary agent weighed in step 1 is placed in 1 / 3 of the deionized water weighed in step 1, and all the chitosan weighed in step 1 is slowly added, and the mixture is stirred and dispersed at room temperature at a speed of 300 rpm for 12 min, and then the mixture is heated to 70°C and stirred and emulsified at a speed of 1200 rpm for 40 min, and then all the zinc oxide and barium sulfate weighed in step 1 are slowly added, and the mixture is stirred and dispersed at 70°C and a speed of 700 rpm for 20 min, and the amount of water lost in step 3 due to stirring and dispersing is determined by weighing, and then supplemented to obtain a second filler dispersion;

[0043] 4. Preparation of modified water-based aldehyde-ketone resin: At room temperature and 200 rpm, add all the modifiers weighed in step 1 to 1 / 3 of the deionized water weighed in step 1, then add 1 / 3 of the comprehensive additive weighed in step 1 and stir for 8 minutes, heat to 70°C, adjust the speed at 1150 rpm and slowly add all the water-based aldehyde-ketone resin weighed in step 1, keep warm at 70°C for 12 minutes, cool to room temperature, determine the amount of water lost in step 4 due to stirring and dispersion by weighing, then replenish it, and then add 1 / 12 of the comprehensive additive weighed in step 1; adjust the speed to 750 rpm, add the first filler premix prepared in step 2, and then add the second filler dispersion prepared in step 3, adjust the speed to 1300 rpm and stir and disperse for 35 minutes, adjust the speed to 750 rpm, slowly add the remaining deionized water weighed in step 1 and the remaining comprehensive additive weighed in step 1, stir for 12 minutes, and filter out the material.

[0044] Test 2: This test differs from Test 1 in that:

[0045] In step 1, the raw materials are weighed according to the following weight parts: 16 parts of deionized water, 34 parts of the first filler, 8 parts of the second filler, 33 parts of the modified water-based aldehyde-ketone resin and 9 parts of the comprehensive auxiliary agent;

[0046] The first filler is attapulgite, which is composed of 6 parts of attapulgite, 25 parts of titanium dioxide and 3 parts of lithopone by weight;

[0047] The second filler is modified chitosan, which is composed of 4 parts of chitosan and 4 parts of barium sulfate by weight;

[0048] The modified water-based aldehyde-ketone resin is composed of 7 parts of water-based aldehyde-ketone resin and 26 parts of modifier by weight; the modifier is water-based acrylic resin. Others are the same as those in Experiment 1.

[0049] Test 3: This test differs from Test 1 in that:

[0050] In step 1, the raw materials are weighed according to the following weight parts: 18.5 parts of deionized water, 35 parts of the first filler, 15 parts of the second filler, 26 parts of the modified water-based aldehyde-ketone resin and 5.5 parts of the comprehensive auxiliary agent;

[0051] The first filler is attapulgite, which is composed of 10 parts of attapulgite and 25 parts of titanium dioxide by weight;

[0052] The second filler is modified chitosan, which is composed of 6 parts of chitosan, 7 parts of barium sulfate and 2 parts of zinc oxide by weight;

[0053] The modified water-based aldehyde-ketone resin is composed of 6 parts of water-based aldehyde-ketone resin and 20 parts of a modifier by weight; the modifier is polyurethane. Others are the same as those in Experiment 1.

[0054] Test 4: This test differs from Test 1 in that:

[0055] In step 1, the raw materials are weighed according to the following weight parts: 22.5 parts of deionized water, 32 parts of the first filler, 12 parts of the second filler, 26 parts of the modified water-based aldehyde-ketone resin and 7.5 parts of the comprehensive auxiliary agent;

[0056] The first filler is attapulgite, which is composed of 8 parts of attapulgite and 24 parts of titanium dioxide by weight;

[0057] The second filler is modified chitosan, which is composed of 7 parts of chitosan and 5 parts of zinc oxide by weight;

[0058] The modified water-based aldehyde-ketone resin is composed of 6 parts of water-based aldehyde-ketone resin and 20 parts of a modifier by weight; the modifier is an epoxy resin. Others are the same as those in Experiment 1.

[0059] The coatings prepared in Tests 1 to 4 were tested for performance. Figure 1 is the spectrum of sunlight reflectance, Figure 2 The spectrum of atmospheric window emissivity is shown in Table 1. The numbers in the figure correspond to the test groups. The optical performance analysis of the two figures can obtain the following data in Table 1:

[0060] Table 1 (JGT20235-2014 Building reflective thermal insulation coating)

[0061]

[0062] The above coatings were subjected to conventional performance tests (GB / T 9779-2015 Multilayer Architectural Coatings), and the data are shown in Table 2:

[0063] Table 2

[0064]

[0065] It can be seen from the above characterization results that the coating prepared by the present invention has a continuously stable high solar reflectance and atmospheric window emissivity, and has excellent weather resistance, water resistance and stain resistance, and can truly achieve the effect of "not attaching but not sticking" to pollutants, thereby achieving permanent cleaning and realizing continuous radiant cooling effect.

Claims

1. A highly stain-resistant radiation refrigeration coating, characterized in that The highly anti-fouling radiation refrigeration coating is composed of the following components in parts by weight: 12 to 23 parts of deionized water, 16 to 35 parts of a first filler, 6 to 15 parts of a second filler, 24 to 37 parts of a modified water-based aldehyde-ketone resin and 5 to 10 parts of a comprehensive additive.

2. A highly anti-fouling radiation refrigeration coating according to claim 1, characterized in that The first filler is attapulgite.

3. A highly anti-fouling radiation refrigeration coating according to claim 2, characterized in that The filled attapulgite is composed of 5 to 10 parts of attapulgite, 11 to 25 parts of titanium dioxide and 0 to 25 parts of lithopone by weight.

4. A highly anti-fouling radiation refrigeration coating according to claim 3, characterized in that The second filler is modified chitosan.

5. A highly anti-fouling radiation refrigeration coating according to claim 4, characterized in that The modified chitosan is composed of 2 to 8 parts of chitosan, 4 to 7 parts of barium sulfate and 0 to 7 parts of zinc oxide in parts by weight.

6. The strong anti-fouling radiation refrigeration coating according to claim 5, characterized in that The modified water-based aldehyde-ketone resin is composed of 6 to 11 parts of water-based aldehyde-ketone resin and 0 to 26 parts of a modifier in terms of weight.

7. The strong anti-fouling radiation refrigeration coating according to claim 6, characterized in that The modifier is polyurethane, water-based acrylic resin or epoxy resin.

8. The strong anti-fouling radiation refrigeration coating according to claim 7, characterized in that The comprehensive auxiliary agent is polyether modified polysiloxane.

9. The method for preparing a highly anti-fouling radiation refrigeration coating according to claim 8, characterized in that The preparation method of the medium-strength pollution-resistant radiation refrigeration coating is carried out according to the following steps:

1. Weigh the raw materials by weight; 2. Preparation of the first filler premix: put 1 / 5 to 1 / 3 of the comprehensive auxiliary agent weighed in step 1 into 1 / 4 to 1 / 3 of the deionized water weighed in step 1, stir at a speed of 150 to 350 rpm for 3 to 6 min, then adjust the speed to 450 to 650 rpm, add all the attapulgite weighed in step 1 and stir for 10 to 15 min, then add all the titanium dioxide and lithopone weighed in step 1 in sequence, adjust the speed to 800 to 950 rpm after the addition is completed, and stir for 15 to 30 min to obtain the first filler premix; 3. Preparation of the second filler dispersion: 1 / 8 to 1 / 5 of the comprehensive auxiliary agent weighed in step 1 is put into 1 / 4 to 1 / 3 of the deionized water weighed in step 1, and all the chitosan weighed in step 1 is slowly added, and the mixture is stirred and dispersed at a speed of 200 to 400 rpm at room temperature for 10 to 15 min, and then the mixture is heated to 60°C to 80°C and stirred and emulsified at a speed of 1000 to 1500 rpm for 15 to 45 min, and then all the zinc oxide and barium sulfate weighed in step 1 are slowly added, and the mixture is stirred and dispersed at a speed of 600 to 800 rpm at 60°C to 80°C for 10 to 20 min, and the amount of water lost in step 3 due to stirring and dispersing is determined by weighing, and then supplemented to obtain a second filler dispersion; 4. Preparation of modified water-based aldehyde-ketone resin: At room temperature and 150 rpm to 300 rpm, add all the modifiers weighed in step 1 to 1 / 4 to 1 / 3 of the deionized water weighed in step 1, then add 1 / 4 to 1 / 3 of the comprehensive auxiliary agent weighed in step 1 and stir for 5 min to 10 min, heat to 65°C to 72°C, adjust the speed to 800 rpm to 1250 rpm and slowly add all the water-based aldehyde-ketone resin weighed in step 1, keep warm at 65°C to 72°C for 10 min to 15 min, cool to room temperature, and determine by weighing the amount of water-based aldehyde-ketone resin weighed in step 4 due to stirring and dispersion. The lost amount of water is then replenished, and 1 / 15 to 1 / 10 of the comprehensive additive weighed in step one is added; the rotation speed is adjusted to 650 rpm to 850 rpm, the first filler premix prepared in step two is added, and then the second filler dispersion prepared in step three is added, the rotation speed is adjusted to 1200 rpm to 1500 rpm and stirred for 25 min to 45 min, the rotation speed is adjusted to 650 rpm to 950 rpm, the remaining deionized water weighed in step one and the remaining comprehensive additive weighed in step one are slowly added, and then stirred for 10 min to 15 min, and the material is filtered out.

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