Odor-free temperature-sensitive coating and preparation method thereof

Abstract

The invention relates to the field of high-performance coatings, in particular to an odorless temperature-sensitive coating which comprises acrylic resin emulsion with the solid content of 50%, a dispersing agent, a defoaming agent, aerogel powder, hollow glass beads, a flatting agent, deionized water, hollow glass beads, a thickening agent and a sterilizing agent, the proportioning range of the emulsion is 20-30%, and the glass transition temperature is 0-8 DEG C; wherein a hard monomer of the emulsion adopts methyl methacrylate or methyl methacrylate and styrene, and the methyl methacrylate accounts for more than 40% of the total hard monomer; the particle size of the hollow glass beads is 40-70 [mu] m, and the particle size of the aerogel is 15-30 [mu] m; the coating is odorless and environment-friendly, has the hardness of more than 75A and the flexibility of 50mm, does not crack, can form a film at the film-forming temperature of more than or equal to 5 DEG C without adding a coalescing agent, and has important practical significance and market value.

Description

Technical Field

[0001] The present invention relates to the technical field of coatings, and particularly relates to a high-performance coating with hardness and flexibility, odorless and ammonia-free, and a preparation method thereof. Background Art

[0002] Existing coatings, especially aerogel coatings, have a large oil absorption capacity, are more prone to cracking than ordinary coatings, often require the addition of film-forming aids to form a film, and may contain harmful substances such as ammonia, with a strong odor, which is not conducive to the environment and human health; at the same time, it is difficult to achieve a good balance between hardness and flexibility; it cannot meet the market demand for environmentally friendly and high-performance coatings. Summary of the Invention

[0003] The purpose of the present invention is to provide an odorless temperature-sensitive coating and a preparation method thereof, which are odorless and environmentally friendly, have a hardness > 75A, flexibility of 50 mm without cracking, and can form a film at a film-forming temperature ≥ 5 °C without the addition of film-forming aids, having important practical significance and market value.

[0004] In order to achieve the above purpose, the technical solution adopted by the present invention is: an odorless temperature-sensitive coating, including an acrylic resin emulsion with a solid content of 50%, a dispersant, an antifoaming agent, an aerogel powder, hollow glass microbeads, a leveling agent, deionized water, hollow glass microbeads, a thickener, and a bactericide. The proportion range of the emulsion is 20 - 30%, and the glass transition temperature is 0 - 8 °C; among them, the hard monomer of the emulsion is methyl methacrylate or methyl methacrylate and styrene, and the proportion of methyl methacrylate in the total hard monomer needs to be > 40%; the particle size of the hollow glass microbeads is 40 - 70 μm, and the particle size of the aerogel is 15 - 30 μm.

[0005] Preferably, the proportion range of the dispersant is 1 - 1.5%, the proportion range of the antifoaming agent is 1 - 1.5%, the proportion range of the aerogel powder is 0.5 - 1%, the proportion range of the hollow glass microbeads is 25 - 30%, the proportion range of the leveling agent is 0.5 - 2%, the proportion range of the deionized water is 35 - 45%; the proportion range of the thickener is 1 - 1.5%, and the proportion range of the bactericide is 0.5 - 1.5%.

[0006] Another technical solution of the present invention: a preparation method of an odorless temperature-sensitive coating, characterized by including the following steps: Step 1: Weigh the components in the formula according to the proportion; Step 2: Add the acrylic resin emulsion, aerogel, and thickener to a stirring container, start the stirrer, and adjust the speed to 1000 - 1200 rpm and stir for 10 - 15 minutes; Step 3: Place the dispersant, antifoaming agent, and bactericide in the stirring container, start the stirrer, and adjust the speed to 500 rpm and stir for 5 minutes; Step 4: Add glass beads into a stirring container, start the stirrer, and adjust the speed to 800 - 1000 rpm to stir for 10 minutes to obtain a smell-free temperature-sensitive coating.

[0007] The technical effects of the present invention are as follows: The glass transition temperature Tg of the emulsion is less than 0 °C, and the hardness after curing is less than 75A. It is not suitable as an interior wall coating and is prone to breakage; when Tg is greater than 8 °C, the film-forming temperature is higher than 5 °C, and the film cracks. It is necessary to add a film-forming aid to achieve smell-free, and specifically, the VOC is greater than 5 g / L. The temperature setting of this application enables the coating to have both hardness and flexibility, and at the same time can meet the requirement of film formation without adding a film-forming aid, truly achieving smell-free and ammonia-free. Due to the large steric hindrance of the benzene ring in styrene, its rotation restricts the rotation of the main chain. At the same glass transition temperature, methyl methacrylate has better flexibility. When the proportion of methyl methacrylate in the hard monomer is less than or equal to 40%, its flexibility does not meet the flexibility of a 2 mm coating with a diameter of 50 mm, and when it is greater than 40%, it meets the requirement.

[0008] When the emulsion content is less than 20%, the flexibility does not meet the requirement, and when it is greater than 30%, the anti-condensation condition cannot be met; The coating of the present invention is smell-free and environmentally friendly, has a hardness > 75A, a flexibility of 50 mm without cracking, and can form a film at a film-forming temperature ≥ 5 °C without adding a film-forming aid, which has important practical significance and market value. Description of the Drawings

[0009] Figure 1 It is a hardness test chart of some examples and comparative examples.

[0010] Figure 2 It is a film appearance chart of some examples and comparative examples.

[0011] Figure 3 It is a test report of VOC detection for Example 1.

[0012] Figure 4 It is a flexibility test chart of some examples and comparative examples.

[0013] Figure 5 It is a comparison test chart of anti-condensation test. Specific Embodiments

[0014] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to examples. It should be understood that the specific examples described herein are only used to explain the present invention and are not used to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0015] Examples of the present invention and corresponding comparative examples are as follows: Example 1

[0016] Prepare the following components in parts by weight: acrylic resin emulsion: 20, preferably an acrylic emulsion with a solid content of 50% (methyl methacrylate accounts for 50% of the total hard monomers), glass transition temperature Tg = 0 °C; hollow glass microspheres: 28; aerogel powder: 0.9; dispersant: 1.2; defoamer: 1.1; thickener: 1.3; bactericide: 0.5; deionized water: 42; 2) Add the acrylic resin emulsion, aerogel, and thickener to a stirring container, start the stirrer, and stir at a speed of 1000 - 1200 rpm for 10 - 15 minutes; 3) Place the dispersant, defoamer, and bactericide in the stirring container, start the stirrer, and stir at a speed of 500 rpm for 5 minutes; 4) Add the glass microspheres to the stirring container, start the stirrer, and stir at a speed of 800 - 1000 rpm for 10 minutes to obtain a low - odor temperature - sensitive coating Example 2

[0017] Prepare the following components in parts by weight: acrylic resin emulsion: 25, preferably an acrylic emulsion with a solid content of 50% (methyl methacrylate accounts for 50% of the total hard monomers), glass transition temperature Tg = 0 °C; hollow glass microspheres: 25; aerogel powder: 0.9; dispersant: 1.2; defoamer: 1.2; thickener: 1.2; bactericide: 0.5; deionized water: 41; 2) Add the acrylic resin emulsion, aerogel, and thickener to a stirring container, start the stirrer, and stir at a speed of 1000 - 1200 rpm for 10 - 15 minutes; 3) Place the dispersant, defoamer, and bactericide in the stirring container, start the stirrer, and stir at a speed of 500 rpm for 5 minutes; 4) Add the glass microspheres to the stirring container, start the stirrer, and stir at a speed of 800 - 1000 rpm for 10 minutes to obtain a low - odor temperature - sensitive coating Example 3

[0018] Prepare the following components in parts by weight: acrylic resin emulsion: 30, preferably an acrylic emulsion with a solid content of 50% (methyl methacrylate accounts for 50% of the total hard monomers), glass transition temperature Tg = 0 °C; hollow glass microspheres: 26; aerogel powder: 0.5; dispersant: 1; defoamer: 1; thickener: 1; bactericide: 0.5; deionized water: 40; 2) Add acrylic resin emulsion, aerogel, and thickener into a stirring container, start the stirrer, and stir at a speed of 1000 - 1200 rpm for 10 - 15 minutes; 3) Place the dispersant, defoamer, and bactericide in the stirring container, start the stirrer, and stir at a speed of 500 rpm for 5 minutes; 4) Add glass microspheres into the stirring container, start the stirrer, and stir at a speed of 800 - 1000 rpm for 10 minutes to obtain a low - odor temperature - sensitive coating Comparative Example 1 Prepare the following components in parts by weight: acrylic resin emulsion: 17.5, preferably an acrylic emulsion with a solid content of 50% (the proportion of methyl methacrylate in the total hard monomers is 50%), glass transition temperature Tg = 0 °C; hollow glass microspheres: 30; aerogel powder: 1.5; dispersant: 1.5; defoamer: 1.5; thickener: 1.5; bactericide: 1.5; deionized water: 45; 2) Add acrylic resin emulsion, aerogel, and thickener into a stirring container, start the stirrer, and stir at a speed of 1000 - 1200 rpm for 10 - 15 minutes; 3) Place the dispersant, defoamer, and bactericide in the stirring container, start the stirrer, and stir at a speed of 500 rpm for 5 minutes; 4) Add glass microspheres into the stirring container, start the stirrer, and stir at a speed of 800 - 1000 rpm for 10 minutes to obtain a coating.

[0019] Comparative Example 2 Prepare the following components in parts by weight: acrylic resin emulsion: 35, preferably an acrylic emulsion with a solid content of 50% (the proportion of methyl methacrylate in the total hard monomers is 50%), glass transition temperature Tg = 0 °C; hollow glass microspheres: 25; aerogel powder: 0.5; dispersant: 1; defoamer: 1; thickener: 1; bactericide: 0.5; deionized water: 36; 2) Add acrylic resin emulsion, aerogel, and thickener into a stirring container, start the stirrer, and stir at a speed of 1000 - 1200 rpm for 10 - 15 minutes; 3) Place the dispersant, defoamer, and bactericide in the stirring container, start the stirrer, and stir at a speed of 500 rpm for 5 minutes; 4) Add glass microspheres into the stirring container, start the stirrer, and stir at a speed of 800 - 1000 rpm for 10 minutes to obtain a coating Comparative Example 3 Prepare the following components in parts by weight: acrylic resin emulsion: 20, preferably an acrylic emulsion with a solid content of 50% (the proportion of methyl methacrylate in the total hard monomers is 50%), glass transition temperature Tg = 10°C; hollow glass microspheres: 30; aerogel powder: 0.3; dispersant: 1.5; defoamer: 1.3; thickener: 1; bactericide: 0.4; film-forming aid: 0.5; deionized water: 45; 2) Add the acrylic resin emulsion, aerogel, and thickener to a stirring container, start the stirrer, and stir at a speed of 1000 - 1200 rpm for 10 - 15 minutes; 3) Place the dispersant, defoamer, and bactericide in the stirring container, start the stirrer, and stir at a speed of 500 rpm for 5 minutes; 4) Add the glass microspheres to the stirring container, start the stirrer, and stir at a speed of 800 - 1000 rpm for 10 minutes to obtain the coating Example 4

[0020] Prepare the following components in parts by weight: acrylic resin emulsion: 20, preferably an acrylic emulsion with a solid content of 50% (the proportion of methyl methacrylate in the total hard monomers is 50%), glass transition temperature Tg = 8°C; hollow glass microspheres: 28; aerogel powder: 0.9; dispersant: 1.2; defoamer: 1.1; thickener: 1.3; bactericide: 0.5; deionized water: 42; 2) Add the acrylic resin emulsion, aerogel, and thickener to a stirring container, start the stirrer, and stir at a speed of 1000 - 1200 rpm for 10 - 15 minutes; 3) Place the dispersant, defoamer, and bactericide in the stirring container, start the stirrer, and stir at a speed of 500 rpm for 5 minutes; 4) Add the glass microspheres to the stirring container, start the stirrer, and stir at a speed of 800 - 1000 rpm for 10 minutes to obtain a low-odor temperature-sensitive coating. Example 5

[0021] Prepare the following components in parts by weight: acrylic resin emulsion: 20, preferably an acrylic emulsion with a solid content of 50% (the proportion of methyl methacrylate in the total hard monomers is 50%), glass transition temperature Tg = 4°C; hollow glass microspheres: 28; aerogel powder: 0.9; dispersant: 1.2; defoamer: 1.1; thickener: 1.3; bactericide: 0.5; deionized water: 42; 2) Add the acrylic resin emulsion, aerogel, and thickener to a stirring container, start the stirrer, and stir at a speed of 1000 - 1200 rpm for 10 - 15 minutes; 3) Place the dispersant, defoamer, and bactericide in a stirring container, start the stirrer, and stir at a speed of 500 rpm for 5 minutes; 4) Add the glass microspheres to the stirring container, start the stirrer, and stir at a speed of 800 - 1000 rpm for 10 minutes to obtain the odorless temperature-sensitive coating Comparative Example 4 Prepare the following components in parts by weight: acrylic resin emulsion: 20, preferably an acrylic emulsion with a solid content of 50% (the proportion of methyl methacrylate in the total hard monomer is 50%), glass transition temperature Tg = -3°C; hollow glass microspheres: 28; aerogel powder: 0.9; dispersant: 1.2; defoamer: 1.1; thickener: 1.3; bactericide: 0.5; deionized water: 42; 2) Add the acrylic resin emulsion, aerogel, and thickener to the stirring container, start the stirrer, and stir at a speed of 1000 - 1200 rpm for 10 - 15 minutes; 3) Place the dispersant, defoamer, and bactericide in a stirring container, start the stirrer, and stir at a speed of 500 rpm for 5 minutes; 4) Add the glass microspheres to the stirring container, start the stirrer, and stir at a speed of 800 - 1000 rpm for 10 minutes to obtain the coating Comparative Example 5 Prepare the following components in parts by weight: acrylic resin emulsion: 20, preferably an acrylic emulsion with a solid content of 50% (the proportion of methyl methacrylate in the total hard monomer is 50%), glass transition temperature Tg = 10°C; hollow glass microspheres: 28; aerogel powder: 0.9; dispersant: 1.2; defoamer: 1.1; thickener: 1.3; bactericide: 0.5; deionized water: 42; 2) Add the acrylic resin emulsion, aerogel, and thickener to the stirring container, start the stirrer, and stir at a speed of 1000 - 1200 rpm for 10 - 15 minutes; 3) Place the dispersant, defoamer, and bactericide in a stirring container, start the stirrer, and stir at a speed of 500 rpm for 5 minutes; 4) Add the glass microspheres to the stirring container, start the stirrer, and stir at a speed of 800 - 1000 rpm for 10 minutes to obtain the coating Example 6

[0022] Prepare the following components in parts by weight: acrylic resin emulsion: 20, preferably an acrylic emulsion with a solid content of 50% (the proportion of methyl methacrylate in the total hard monomer is 45%), glass transition temperature Tg = 0°C; hollow glass microspheres: 28; aerogel powder: 0.9; dispersant: 1.2; defoamer: 1.1; thickener: 1.3; bactericide: 0.5; deionized water: 42; 2) Add acrylic resin emulsion, aerogel, and thickener to a stirring container, start the stirrer, and stir at a speed of 1000 - 1200 rpm for 10 - 15 minutes; 3) Place the dispersant, defoamer, and bactericide in the stirring container, start the stirrer, and stir at a speed of 500 rpm for 5 minutes; 4) Add glass microspheres to the stirring container, start the stirrer, and stir at a speed of 800 - 1000 rpm for 10 minutes to obtain the coating.

[0023] Comparative Example 6 Prepare the following components in parts by weight: acrylic resin emulsion: 20, preferably an acrylic emulsion with a solid content of 50% (the proportion of methyl methacrylate in the total hard monomer is 40%), glass transition temperature Tg = 0 °C; hollow glass microspheres: 28; aerogel powder: 0.9; dispersant: 1.2; defoamer: 1.1; thickener: 1.3; bactericide: 0.5; deionized water: 42; 2) Add acrylic resin emulsion, aerogel, and thickener to a stirring container, start the stirrer, and stir at a speed of 1000 - 1200 rpm for 10 - 15 minutes; 3) Place the dispersant, defoamer, and bactericide in the stirring container, start the stirrer, and stir at a speed of 500 rpm for 5 minutes; 4) Add glass microspheres to the stirring container, start the stirrer, and stir at a speed of 800 - 1000 rpm for 10 minutes to obtain a low - odor temperature - sensitive coating.

[0024] Comparative Example 7 Prepare the following components in parts by weight: acrylic resin emulsion: 20, preferably an acrylic emulsion with a solid content of 50% (the proportion of methyl methacrylate in the total hard monomer is 35%), glass transition temperature Tg = 0 °C; hollow glass microspheres: 28; aerogel powder: 0.9; dispersant: 1.2; defoamer: 1.1; thickener: 1.3; bactericide: 0.5; deionized water: 42; 2) Add acrylic resin emulsion, aerogel, and thickener to a stirring container, start the stirrer, and stir at a speed of 1000 - 1200 rpm for 10 - 15 minutes; 3) Place the dispersant, defoamer, and bactericide in the stirring container, start the stirrer, and stir at a speed of 500 rpm for 5 minutes; 4) Add glass microspheres to the stirring container, start the stirrer, and stir at a speed of 800 - 1000 rpm for 10 minutes to obtain a low - odor temperature - sensitive coating.

[0025] In the above - mentioned examples and comparative examples, the particle size of the aerogel is 15 - 30 μm, and the particle size of the hollow glass microspheres is 40 - 70 μm.

[0026] The dispersants used in the above-mentioned examples and comparative examples are polyacrylates, acidic polyethers, etc.; the defoamers are silicone, a compound defoamer of mineral oil and fumed silica; the thickeners are alkali-swellable thickeners, cellulose thickeners, etc.; the fungicides are methylisothiazolinone, octylisothiazolinone, etc.

[0027] The hardness, film appearance, and VOC of some of the above examples and comparative examples were tested, and the test results are shown in Table 1 below:

[0028] Some of the test results are as Figures 1-3 shown. It can be seen from the above tests that when Tg is less than 0 °C, the hardness after curing is less than 75A, which is not suitable as an interior wall coating and is prone to breakage; when Tg is greater than 8 °C, the film-forming temperature ≥ 5 °C, and the film cracks, and film-forming aids need to be added to achieve odorless. Specifically, the VOC is greater than 5 g / L; the glass transition temperature of the acrylic resin emulsion should be controlled between 0 - 8 °C to ensure that the coating has appropriate hardness and good film-forming performance when the film-forming temperature ≥ 5 °C, while meeting the requirements of odorless and low VOC.

[0029] The flexibility test was carried out on some of the examples and comparative examples, and the test results are shown in Table 2 below

[0030] Some of the test results are as Figure 4 shown. In the coating, when the hard monomer uses methyl methacrylate in combination with other monomers, when the proportion of methyl methacrylate in the total hard monomer is less than or equal to 40%, the flexibility of the coating does not meet the requirement of 50 mm diameter for 2 mm coating flexibility; while when the proportion of methyl methacrylate in the total hard monomer is greater than 40%, the flexibility requirement can be met. This shows that in this coating system, increasing the proportion of methyl methacrylate in the total hard monomer helps to improve the flexibility of the coating, and when the proportion exceeds 40%, a specific flexibility standard can be achieved.

[0031] The flexibility and anti-condensation test was carried out on some of the examples and comparative examples, and the test results are shown in Table 3 below:

[0032] In a specific coating system, the content of the acrylic resin emulsion plays a key role; when the emulsion content is less than 20%, the flexibility of the coating does not meet the requirements; while when the emulsion content is greater than 30%, the anti-condensation conditions cannot be met. Therefore, in order to make the coating have good flexibility and meet the anti-condensation requirements at the same time, the content of the acrylic resin emulsion should be controlled between 20% and 30%.

[0033] As Figure 5As shown, it is the step diagram of the anti-condensation test and the test result diagrams of Comparative Example 2 and Example 2: Anti-condensation test conditions and steps: a) Coat a 2-mm-thick odorless temperature-sensitive coating and a 2-mm-thick ordinary latex paint on the substrate respectively. b) After complete drying and curing, place the test panels in a constant-temperature oven at a set temperature of 30°C and a humidity of 90%, with the set temperature of the test panels being 18°C and the temperature difference between the environment and the test panels being 12°C; conduct the test in this test environment.

[0034] c) Observe the phenomenon of condensed water appearing on the coating.

[0035] Through the above test comparison, the core technical points can be highlighted: 1. When Tg is less than 0°C and the hardness after curing is less than 75A, it is not suitable as an interior wall coating and is prone to breakage. 2. When Tg is greater than 8°C and the film-forming temperature is higher than 5°C, film cracking occurs and film-forming auxiliaries need to be added, making it impossible to achieve odorless; specifically, the VOC is greater than 5 g / L. 3. For the monomer combination, when the hard monomer methyl methacrylate accounts for less than or equal to 40%, its flexibility does not meet the flexibility of a 2-mm coating with a diameter of 50 mm, and when it is greater than 40%, it meets the requirement.

[0036] 4. When the emulsion content is less than 20%, the flexibility does not meet the requirement, and when it is greater than 30%, the anti-condensation condition cannot be met.

[0037] It should be noted that in this article, the term "including", "comprising" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or elements inherent to such a process, method, article or device.

[0038] In this article, specific examples are used to elaborate on the principle and implementation manner of the present invention. The description of the above examples is only used to help understand the method and its core idea of the present invention. The above is only the preferred implementation manner of the present invention. It should be noted that due to the limited nature of written expression and objectively existing infinite specific structures, for those of ordinary skill in the art in this technical field, without departing from the principle of the present invention, several improvements, modifications or changes can be made, or the above technical features can be combined in an appropriate manner; these improvements, modifications, changes or combinations, or directly applying the concept and technical solution of the invention to other occasions without improvement, shall all be regarded as the protection scope of the present invention.

Claims

1. A odorless temperature-sensitive paint, characterized in that: It includes acrylic resin emulsion with a solid content of 50%, dispersant, defoamer, aerogel powder, hollow glass microbeads, leveling agent, deionized water, hollow glass microbeads, thickener and bactericide, the emulsion ratio range is 20-30%, and the glass transition temperature is 0-8 ℃; the hard monomer of the emulsion adopts methyl methacrylate or methyl methacrylate and styrene, and the proportion of methyl methacrylate in the total hard monomer must be greater than 40%; the particle size of the hollow glass microbeads is 40-70μm, and the particle size of the aerogel is 15-30um.

2. The odorless temperature-sensitive paint according to claim 1, characterized in that: The ratio range of dispersant is 1-1.5%, the ratio range of defoamer is 1-1.5%, the ratio range of aerogel powder is 0.5-1%, the ratio range of hollow glass microbeads is 25-30%, the ratio range of leveling agent is 0.5-2%, the ratio range of deionized water is 35-45%; the ratio range of thickener is 1-1.5%, and the ratio range of bactericide is 0.5-1.5%.

3. The method for preparing a odorless temperature-sensitive coating according to claim 1 or 2, characterized in that: The steps include: Step 1: Weigh the components in the formula according to the ratio; Step 2: Add the acrylic resin emulsion, aerogel and thickener into a stirring container, turn on the stirrer, adjust the speed to 1000-1200 rpm and stir for 10-15 minutes; Step 3: Place the dispersant, defoamer and bactericide in a stirring container, turn on the stirrer, adjust the speed to 500 rpm and stir for 5 minutes; Step 4: Add glass beads into a stirring container, turn on the stirrer, adjust the speed to 800-1000 rpm and stir for 10 minutes to obtain a zero-odor temperature-sensitive paint.

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