High-reflectivity pigment for building exterior wall

Abstract

The invention belongs to the technical field of building coatings, and particularly relates to a high-reflectivity pigment for a building exterior wall. The coating comprises the following components: coated glass beads, a pigment, modified silicon dioxide, resin, an auxiliary agent and water, the modified silicon dioxide is silicon dioxide coated with vinyl triethoxy silane; the coated glass beads are hollow glass beads coated with titanium dioxide. The coating hollow glass beads and the modified silicon dioxide are added in the formula of the coating and act together with various components, so that the coating has good weather resistance on the premise of keeping high reflective rate.

Description

Technical Field

[0001] The invention belongs to the technical field of building coatings, and in particular relates to a high-reflectivity pigment for building exterior walls. Background Art

[0002] The building exterior wall is the main component of the building's external protective structure. It is in direct contact with the external environment and plays the role of enclosure, load bearing, thermal insulation, waterproofing and moisture-proofing, sound insulation and noise reduction, aesthetics, and fire prevention.

[0003] During the summer, when the temperature is high, buildings that have not been specially treated will absorb solar radiation, causing the internal temperature to rise. This will increase the energy consumption of indoor equipment such as air conditioners and refrigerators. Conversely, in winter, untreated building surfaces tend to conduct indoor heat away, resulting in reduced heating efficiency and increased energy consumption.

[0004] Paints for building exterior walls with high light reflectivity can not only be beautiful, but can also effectively reflect ultraviolet and infrared rays in sunlight, reduce the heat absorbed by the building, and achieve energy-saving effects.

[0005] At the same time, reducing heat absorption can reduce the thermal stress and aging rate of building materials (such as concrete, wood, etc.), thereby extending the service life of buildings and their internal facilities.

[0006] Therefore, it is necessary to further optimize the currently available pigments to achieve better results. Summary of the invention

[0007] The invention provides a high-reflectivity pigment for building exterior walls, which has the dual functions of coating glass microspheres and modified silicon dioxide, and improves the light reflectivity of the pigment.

[0008] A high-reflectivity pigment for building exterior walls, comprising the following components by mass percentage:

[0009]

[0010] The modified silica is silica coated with vinyltriethoxysilane;

[0011] The coated glass microspheres are hollow glass microspheres coated with titanium dioxide.

[0012] Preferably, the preparation method of the modified silicon dioxide is:

[0013] The silicon dioxide is dispersed in ethanol, and water and ammonia water are added; vinyl triethoxysilane is then added and heated to react for a period of time; after the reaction, the silicon dioxide is washed and dried to obtain modified silicon dioxide.

[0014] Preferably, the mass ratio of silicon dioxide to vinyltriethoxysilane is 1:0.2-0.4.

[0015] The mass ratio of the silicon dioxide to ethanol, water and ammonia water is 1:10-15:2-3:2-3.

[0016] The reaction temperature is 65-85°C and the reaction time is ≥6h.

[0017] Further preferably, the mass ratio of silicon dioxide to vinyltriethoxysilane is 1:0.3;

[0018] The mass ratio of silicon dioxide to ethanol, water and ammonia water is 1:15:2:2;

[0019] The reaction temperature was 80°C and the reaction time was 6 h.

[0020] Preferably, the resin includes at least one of the following: acrylic acid, polyvinyl acetate, and silicone-acrylic emulsion.

[0021] Preferably, the auxiliary agent includes at least one of the following:

[0022] Defoaming agent, dispersant, thickener, antifreeze agent, wetting agent, film-forming aid.

[0023] The formulation of the present invention takes into account the synergistic effect of multiple ingredients and is intended to improve the reflectivity and weather resistance of exterior wall coatings while maintaining their aesthetics and functionality.

[0024] The silica coated with vinyl triethoxysilane (VTES) used in the present invention helps to improve the weather resistance, adhesion and reflective performance of the pigment; the coating layer can enhance the stability of silica particles in the coating. The present invention finds that compared with the use of 3-aminopropyl triethoxysilane (APTES), methyl trimethoxysilane (MTMS), and dodecyl triethoxysilane (DTES); the effect of improving reflectivity is the best.

[0025] The second special raw material used in the present invention is hollow glass microspheres coated with titanium dioxide, which helps to improve the reflectivity of the pigment; the coated glass microspheres can further improve their reflectivity of visible light and near-infrared light, achieving better thermal insulation performance.

[0026] However, if too much coated hollow glass microspheres are used, the adhesion between the coating and the substrate may be interfered with; more importantly, the color of the pigment will be interfered with by titanium dioxide and the desired color level cannot be achieved.

[0027] If uncoated hollow glass microspheres are used, the amount of added microspheres needs to be increased, which will lead to problems of uneven surface and decreased adhesion.

[0028] At the same time, the present invention finds that there is a certain synergistic effect when the coated hollow glass microspheres and modified silica are used simultaneously, and the reflectivity is obviously higher when the addition amounts are equal.

[0029] The invention adds auxiliary agents such as defoamers and dispersants, which is helpful to improve the construction performance of the coating and the appearance quality of the final coating.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] The present invention adds coated hollow glass microspheres and modified silicon dioxide to the coating formula, and the multiple components work together to achieve good weather resistance of the coating while maintaining high reflectivity. DETAILED DESCRIPTION

[0032] In order to better understand the present invention, the present invention is further described below in conjunction with specific serial numbers, wherein the terms used in the serial numbers are for describing specific embodiments and do not constitute limitations on the scope of protection of the present invention.

[0033] Specific implementation methods, unless otherwise specified, are conventional experimental methods, and the materials, reagents, etc. used, unless otherwise specified, can be obtained from commercial channels.

[0034] The sources of some raw materials used in the present invention are as follows: Table 1:

[0035] Table 1

[0036] name Product Name / Model / Other Name Source (Manufacturer) Coated glass beads Titanium dioxide coated hollow glass microspheres Wanhua Chemical Glass beads 400 mesh hollow glass microspheres Hebei Huishun Mining Co., Ltd. Silicon dioxide Fumed Silica KS-A200 Shandong Kasong New Materials Co., Ltd. Ethanol Anhydrous ethanol Guangzhou Chemical Reagent Factory ammonia Ammonia (analytical grade) Guangzhou Chemical Reagent Factory Vinyltriethoxysilane / Shandong Yuanjin New Materials Co., Ltd. 3-Aminopropyltriethoxysilane / Shandong Yuanjin New Materials Co., Ltd. Methyltrimethoxysilane / Shandong Yuanjin New Materials Co., Ltd. Dodecyltriethoxysilane / Shandong Yuanjin New Materials Co., Ltd. Acrylic resin Thermoplastic acrylic resin Shandong Yuanjin New Materials Co., Ltd. Polyvinyl acetate / Shandong Yuanjin New Materials Co., Ltd. Silicone acrylic emulsion / Shandong Shengkai Chemical Co., Ltd. Defoaming agent / Jinan Sunny Chemical Technology Co., Ltd. Dispersants / Jinan Sunny Chemical Technology Co., Ltd. Thickener / Jinan Sunny Chemical Technology Co., Ltd. antifreeze / Jinan Sunny Chemical Technology Co., Ltd. Wetting agent / Jinan Sunny Chemical Technology Co., Ltd. Film-forming aids / Jinan Sunny Chemical Technology Co., Ltd. Pigments 4352 Phthalocyanine Blue B Guangzhou Meidan Titanium Dioxide Pigment Co., Ltd.

[0037] Example 1 The preparation of modified silicon dioxide comprises the following steps:

[0038] (1) Place the resin in a high-speed mixer, disperse the silica in ethanol, add water and ammonia water, and stir for at least 30 minutes;

[0039] (2) adding silane and heating the reaction for a period of time;

[0040] (3) After the reaction is completed, the product is washed with ethanol and dried in vacuum to obtain modified silica.

[0041] Example 1 The specific reaction conditions and addition amounts are shown in Table 2 below:

[0042] Table 2 Modified silica reaction parameters

[0043]

[0044] Note: " / " in Table 2 indicates no addition or inapplicability, and the raw materials are from the manufacturers and corresponding models written in Table 1. Example 2 Preparation of a high reflectivity building exterior wall pigment, comprising the following steps:

[0045] (1) Put the resin into a high-speed mixer, add additives, and continue stirring;

[0046] (2) adding solid components such as glass beads and modified silica;

[0047] (3) Add colorant and water, stir evenly to obtain a high reflectivity paint for building exterior walls.

[0048] Example 2 The specific reaction conditions and addition amounts are shown in Table 3 below:

[0049] Table 3 Reaction parameters of pigments for high reflectivity building exterior walls

[0050]

[0051]

[0052] Table 3 Reaction parameters of high reflectivity pigments for building exterior walls (continued)

[0053]

[0054] Note: “ / ” in Table 3 means no addition or not applicable, the raw materials come from the manufacturers and corresponding models written in Table 1; the modified silica group comes from the corresponding group in Table 2 in Example 1.

[0055] Performance test

[0056] The high reflectivity building exterior wall pigment prepared in Example 2 was subjected to relevant performance tests:

[0057] 1. Solar reflectance (TSR): Based on JG / T 235-2014 "Architectural reflective thermal insulation coatings";

[0058] 2. Storage stability: Based on GB / T 9268-2008 "Determination of freeze-thaw resistance of latex paint";

[0059] 3. Construction performance: Based on GB / T 9755-2014 "Synthetic resin emulsion exterior wall coating";

[0060] 4. Abrasion resistance: GB / T 1768-2006 "Determination of abrasion resistance of paints and varnishes - Rotating rubber grinding wheel method";

[0061] The results are shown in Table 4 below.

[0062] Table 4 Performance test of high reflectivity paint for building exterior walls

[0063]

[0064]

[0065] According to the results in Table 4: when uncoated glass beads are used (Group 7), the reflectivity will drop significantly; by comparing Group 1 with Groups 8, 9, and 10, when 3-aminopropyltriethoxysilane (APTES), methyltrimethoxysilane (MTMS), and dodecyltriethoxysilane (DTES) are used for coating, the reflectivity is poor. The results of Group 11 show that when unmodified silica is used, not only will the solar reflectivity drop, but also the wear resistance will drop. The results of Group 12 show that when an excessive amount of coated glass beads is used, although the solar reflectivity does not drop significantly, the wear resistance will be greatly reduced, ultimately resulting in a decrease in service life.

[0066] The above detailed description is a specific description of one feasible embodiment of the present invention. The embodiment is not intended to limit the patent scope of the present invention. Any equivalent implementation or modification that does not deviate from the present invention should be included in the scope of the technical solution of the present invention.

Claims

1. A high reflectivity paint for building exterior walls, characterized in that: The following components are included by mass percentage: The modified silica is silica coated with vinyltriethoxysilane; The coated glass microspheres are hollow glass microspheres coated with titanium dioxide.

2. The high reflectivity paint for building exterior walls according to claim 1, characterized in that: The preparation method of the modified silicon dioxide is: The silicon dioxide is dispersed in ethanol, and water and ammonia water are added; vinyl triethoxysilane is then added and heated to react for a period of time; after the reaction, the silicon dioxide is washed and dried to obtain modified silicon dioxide.

3. The high reflectivity paint for building exterior walls according to claim 2, characterized in that: The mass ratio of silicon dioxide to vinyltriethoxysilane is 1:0.2-0.

4.

4. The high reflectivity paint for building exterior walls according to claim 2, characterized in that: The mass ratio of the silicon dioxide to ethanol, water and ammonia water is 1:10-15:2-3:2-3.

5. The high reflectivity paint for building exterior walls according to claim 2, characterized in that: The reaction temperature is 65-85°C and the reaction time is ≥6h.

6. The high reflectivity paint for building exterior walls according to claim 2, characterized in that: The mass ratio of silica to vinyltriethoxysilane is 1:0.3; The mass ratio of silicon dioxide to ethanol, water and ammonia water is 1:15:2:2; The reaction temperature was 80°C and the reaction time was 6 h.

7. The high reflectivity paint for building exterior walls according to claim 1, characterized in that: The resin includes at least one of the following: acrylic acid, polyvinyl acetate, and silicone-acrylic emulsion.

8. The high reflectivity paint for building exterior walls according to claim 1, characterized in that: The auxiliary agent includes at least one of the following: Defoaming agent, dispersant, thickener, antifreeze agent, wetting agent, film-forming aid.

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