Modified hollow glass bead as well as preparation and application thereof
By coating hollow glass microspheres with titanium dioxide and polishing them, their reflectivity to near-infrared light is improved, solving the problem that existing heat-insulating coatings cannot effectively insulate heat. This achieves a dual heat-insulating mechanism of blocking and reflecting heat, improving the heat insulation performance and weather resistance of water-based inorganic coatings.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-07-05
- Publication Date
- 2026-04-10
AI Technical Summary
Existing heat insulation coatings cannot effectively insulate heat. Barrier-type heat insulation coatings still accumulate heat under sunlight, while reflective-type heat insulation coatings absorb some energy and cannot achieve excellent heat insulation effects.
A titanium dioxide layer was coated on the surface of hollow glass microspheres, and polished with nano-silica sol to improve their reflectivity to near-infrared light, giving the hollow glass microspheres a reflective heat insulation effect. Combined with the heat insulation mechanism, modified hollow glass microspheres were prepared for use in water-based inorganic coatings.
The prepared modified hollow glass microspheres have a dual heat insulation mechanism of both barrier and reflective heat insulation, which improves the heat insulation, weather resistance, wear resistance and fire retardant properties of water-based inorganic coatings, achieving excellent heat preservation and energy-saving effects.
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Figure CN121825281A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of water-based inorganic coating, in particular to a modified hollow glass microsphere and its preparation and application. BACKGROUND
[0002] With the low-carbon economy becoming a global theme, energy saving and environmental protection and other issues are attracting more and more attention. Building energy consumption accounts for about one-third of human society's energy consumption, and the poor heat insulation effect of traditional buildings is the main reason for building energy loss, so heat insulation coatings have been concerned in recent years. Coating heat insulation coatings on the interior and exterior walls of buildings can effectively block the heat transfer and exchange between indoor and outdoor or between rooms. In summer, it can maintain the cool temperature of indoor air conditioning, and in winter, it can maintain the heat of indoor heating. Therefore, such heat insulation coatings have good heat insulation and thermal insulation effects on buildings, and can also achieve the purpose of energy saving and consumption reduction.
[0003] The existing technology uses coatings with heat insulation function, which can be divided into barrier type heat insulation coatings and reflective type heat insulation coatings according to the heat insulation mechanism. Among them, the barrier type heat insulation coating has a low thermal conductivity, and the hollow glass microsphere has a very low thermal conductivity, which can be used as a very excellent barrier type heat insulation filler for heat insulation coatings, and can insulate most of the heat, but under the long-time irradiation of sunlight, part of the heat will still accumulate on its surface; while the reflective type heat insulation coating has a high reflectivity to sunlight, which can reflect most of the energy in the sunlight or the heat source infrared radiation, thereby achieving a reflective type heat insulation effect, but a small part of the energy will still be absorbed; that is, the above two coatings cannot effectively insulate heat.
[0004] Therefore, the present application provides a modified hollow glass microsphere and its preparation and application. SUMMARY
[0005] In order to solve the problem that the coatings with heat insulation function in the above-mentioned prior art cannot effectively insulate heat, the present application provides a modified hollow glass microsphere and its preparation and application. The present application improves the reflectivity of the hollow glass microsphere to near-infrared light by modifying the hollow glass microsphere and polishing the surface after coating a silica layer, and gives the hollow glass microsphere a reflective heat insulation effect, so that the treated hollow glass microsphere has both barrier heat insulation and reflective heat insulation mechanisms, thereby improving the heat insulation performance of the overall coating.
[0006] The modified hollow glass microsphere and its preparation and application of the present application are realized by the following technical scheme:
[0007] The first object of the present application is to provide a preparation method of a modified hollow glass microsphere, comprising the following steps:
[0008] Step 1, depositing a layer of titanium dioxide on the surface of hollow glass beads to obtain hollow glass beads coated with titanium dioxide;
[0009] Step 2, mixing the hollow glass beads coated with titanium dioxide with nano-silica sol and stirring to obtain the modified hollow glass beads.
[0010] Further, the particle size of the hollow glass beads is 80-500 mesh.
[0011] Further, the particle size of the hollow glass beads is 125-325 mesh.
[0012] Further, the solid content of nano-SiO2 in the nano-silica sol is 28%-32%, and the particle size of nano-SiO2 is 5-15 nm.
[0013] Further, the stirring rate of the stirring treatment is 500-1500 r / min, and the stirring time is 1-120 min.
[0014] Further, the hollow glass beads coated with titanium dioxide are obtained by the following steps:
[0015] 1) mixing tetrabutyl titanate and anhydrous ethanol in a volume ratio of 1:1.5-2.5 to obtain solution A;
[0016] Mixing anhydrous ethanol and water in a volume ratio of 4.5-5.5:1 to obtain solution B;
[0017] Dispersing the hollow glass beads uniformly in anhydrous ethanol to obtain solution C;
[0018] The content of hollow glass beads in solution C is 1%-30%;
[0019] 2) Under the action of stirring, the solution A and solution B are added to the solution C at the same time and mixed uniformly, after the addition is completed, continue to stir for 1-2 h, solid-liquid separation, washing and drying to obtain the precursor material;
[0020] 3) heat treating the precursor material at 350-650℃ for 0.5-1.5h to convert the coating layer precursor titanium hydroxide into titanium dioxide, and further obtain the hollow glass beads coated with titanium dioxide.
[0021] Further, the content of hollow glass beads in solution C is 5%-20%.
[0022] Further, in step 2), the stirring rate is 100-600 r / min.
[0023] The second object of the present application is to provide a modified hollow glass microsphere prepared by the above preparation method.
[0024] The third object of the present application is to provide an application of the above modified hollow glass microsphere in preparing a water-based inorganic coating, wherein the modified hollow glass microsphere is used as a heat insulation filler.
[0025] The fourth object of the present application is to provide a water-based inorganic coating, which is composed of the following components by weight:
[0026] The modified hollow glass microsphere 0.5-20 parts, the alkali metal silicate 25-40 parts, water 20-30 parts, the wetting dispersant 0.2-0.8 parts, the defoaming agent 0.2-1 part, the thickening agent 0.2-0.5 parts, the leveling agent 0.2-0.5 parts, the talc powder 6-10 parts, the titanium white powder 4-8 parts, the heavy calcium carbonate powder 10-18 parts, the dolomite powder 1-5 parts, the emulsion 3-5 parts, and the film-forming aid 0.1-1 part.
[0027] Further, the alkali metal silicate is a potassium silicate aqueous solution, and the modulus of the potassium silicate aqueous solution is not less than 2.5.
[0028] The fifth object of the present application is to provide a preparation method of the above water-based inorganic coating, which is characterized by comprising the following steps:
[0029] S1, each preparation raw material is weighed according to the following ratio, and is prepared for use:
[0030] The modified hollow glass microsphere 0.5-20 parts, the alkali metal silicate 25-40 parts, water 20-30 parts, the wetting dispersant 0.2-0.8 parts, the defoaming agent 0.2-1 part, the thickening agent 0.2-0.5 parts, the leveling agent 0.2-0.5 parts, the talc powder 6-10 parts, the titanium white powder 4-8 parts, the heavy calcium carbonate powder 10-18 parts, the dolomite powder 1-5 parts, the emulsion 3-5 parts, and the film-forming aid 0.1-1 part.
[0031] S2, half of the thickening agent weighed above is placed in the water weighed, and is stirred at a stirring rate of 450-550 r / min for 10-15 min, so that the thickening agent is uniformly dispersed in the water to obtain a solution A;
[0032] S3, half of the thickening agent weighed above is placed in the water weighed, and is stirred at a stirring rate of 450-550 r / min for 10-15 min, so that the thickening agent is uniformly dispersed in the water to obtain a solution B;
[0033] S4, the weighed talc powder, titanium dioxide, heavy calcium carbonate powder, dolomite powder are placed in the above solution B in turn, and stirred at a stirring rate of 1100-1300 r / min for 30-60 min, so that the talc powder, titanium dioxide, heavy calcium carbonate powder, dolomite powder are uniformly dispersed, and solution C is obtained;
[0034] S5, the weighed emulsion is placed in solution C, and stirred at a stirring rate of 1100-1300 r / min for 10 min, then the alkali metal silicate is added and stirred at a stirring rate of 950-1050 r / min for 8-12 min, then the above modified hollow glass microspheres are added and stirred at a stirring rate of 150-250 r / min for 15-25 min, and solution D is obtained;
[0035] S6, the remaining half amount of thickening agent and half amount of defoaming agent are added to the solution D, and stirred at a stirring rate of 150-250 r / min for 10-20 min, and the aqueous inorganic paint is obtained.
[0036] Compared with the prior art, the present application has the following beneficial effects:
[0037] The present application takes hollow glass microspheres as the matrix, coats a layer of titanium dioxide on the surface of the hollow glass microspheres to improve the reflectivity of the hollow glass microspheres to visible and infrared light, and further improves the reflectivity of the hollow glass microspheres to visible and infrared light by surface polishing treatment of the hollow glass microspheres coated with a layer of titanium dioxide through a silica sol, thereby obtaining modified hollow glass microspheres with excellent reflective and thermal insulation effects.
[0038] And the modified hollow glass microspheres prepared by the present application are used as thermal insulation fillers for preparing aqueous inorganic paint, which has excellent thermal insulation, good weather resistance, strong water and wear resistance, and fireproofing and other advantages, and the coating of the building wall has excellent heat preservation and energy saving effect. BRIEF DESCRIPTION OF DRAWINGS
[0039] Figure 1 The test results of the visible light and near-infrared light reflection performance of the aqueous inorganic paint of Examples 4-6 and Comparative Examples 3-4. DETAILED DESCRIPTION
[0040] As described in the background, the barrier type thermal insulation coating and the reflective type thermal insulation coating adopted in the prior art cannot effectively perform thermal insulation, and it is necessary to provide a coating with good thermal insulation performance. The inventors found in the process of improving the prior art that the hollow glass microbeads as the thermal insulation filler in the coating of the prior art have excellent barrier thermal insulation effect, but the infrared reflectivity is still not high, and the reflective thermal insulation effect is not ideal, so the present application attempts to improve the thermal insulation performance of the thermal insulation filler by modifying the hollow glass microbeads, and then improve the thermal insulation performance of the whole coating. The inventors consider that the heat radiation received by the coating is mainly radiated by near-infrared light, so the present application attempts to improve the reflectivity of the hollow glass microbeads to near-infrared light, and give the hollow glass microbeads a reflective thermal insulation effect, so that the treated hollow glass microbeads have a double thermal insulation mechanism of barrier thermal insulation and reflective thermal insulation, and then improve the thermal insulation performance of the whole coating. And the technical scheme of the present application will be described in detail in combination with the following embodiments. It should be noted that the nano-silica sol used in the following embodiments of the present application is JN-830 type nano-silica sol produced by Linyi Kohan Silicon Products Co., Ltd. The particle size of nano-SiO2 particles in JN-830 nano-silica sol is 7-10 nm, and the content is 29%-31%; the wet dispersing agent used is DISPERBYK-187 produced by BYK Company of Germany; the defoaming agent used is BYK-1710 produced by BYK Company of Germany; the thickening agent used is OPTIGEL-W 724 produced by BYK Company of Germany; the leveling agent used is BYK-3550 produced by BYK Company of Germany; and the film-forming aid used is alcohol ester twelve produced by Dow Chemical Company of the United States.
[0041] The present application provides a modified hollow glass microbead, and a preparation method thereof comprises the following steps:
[0042] Step 1, depositing a layer of titanium dioxide on the surface of the hollow glass microbead to obtain a hollow glass microbead coated with titanium dioxide on the surface;
[0043] It should be noted that the present application considers that the reflectivity of the hollow glass microbead to near-infrared light is about 1.51, so when selecting the coating material, as long as the surface of the hollow glass microbead can be modified to improve the infrared emissivity of the material surface, but in fact there are few materials that meet the above conditions, for example, the surface of the hollow glass microbead can be modified by using an aluminum oxide coating layer, but the refractive index of aluminum oxide is only about 1.72, which is much lower than that of titanium dioxide (-2.87), and only slightly larger than that of glass, so the improvement effect of the light reflectivity of the hollow glass microbead is not good, and it cannot be used as an ideal surface coating layer, so the present application finally optimizes titanium dioxide as the modified coating material.
[0044] It should be further explained that the present application is not limited to the specific way of coating titanium dioxide on the surface of hollow glass microspheres, as long as a uniform layer of titanium dioxide can be coated on the surface of hollow glass microspheres. In order to improve the coating effect of the coated titanium dioxide on the surface of hollow glass microspheres, the present application preferably uses the following steps for coating:
[0045] The tetrabutyl titanate and anhydrous ethanol are mixed in a volume ratio of 1:1.5-2.5 to obtain solution A; the anhydrous ethanol and water are mixed in a volume ratio of 4.5-5.5:1 to obtain solution B; the hollow glass microspheres are uniformly dispersed in anhydrous ethanol to obtain solution C; under stirring, the solution A and the solution B are simultaneously added to the solution C and mixed uniformly, after the addition is completed, the stirring is continued for 1-2 h, and then the solid-liquid separation is performed, followed by washing and drying to obtain a precursor material; the precursor material is heat-treated at 350-650°C for 0.5-1.5 h to convert the coating layer precursor material titanium hydroxide into titanium dioxide, and then the hollow glass microspheres coated with titanium dioxide are obtained.
[0046] In the present application, in order to uniformly disperse the hollow glass microspheres in anhydrous ethanol, the stirring rate is preferably 100-600 r / min for 10-30 min to uniformly disperse the hollow glass microspheres in anhydrous ethanol, and a solution C with uniform components is obtained, so as to facilitate the subsequent full contact of the hollow glass microspheres with the tetrabutyl titanate.
[0047] In order to make the hollow glass microspheres fully contact with the tetrabutyl titanate, so as to facilitate the hydrolysis reaction of the tetrabutyl titanate in the solution C and the formation of a titanium hydroxide coating layer on the surface of the hollow glass microspheres, the present application preferably simultaneously adds the solution A and the solution B to the solution C while keeping the solution C under stirring, and the dropping speed of the solution A and the solution B is kept consistent, after the addition of the solution A and the solution B is completed, the stirring is continued at a stirring rate of 100-600 r / min for 1-2 h to fully perform the hydrolysis reaction and uniformly form a titanium hydroxide coating layer on the surface of the hollow glass microspheres. In the subsequent heat treatment process, the titanium hydroxide coating on the surface of the hollow glass microspheres is converted into titanium dioxide, and then the hollow glass microspheres coated with titanium dioxide are obtained.
[0048] In order to ensure the coating effect of titanium dioxide on the surface of the final hollow glass microspheres, the content of the hollow glass microspheres in the solution C is preferably 1%-30%, and more preferably 5%-20%.
[0049] Step 2, mixing the hollow glass microspheres coated with titanium dioxide with nano-silica sol and performing stirring treatment to obtain the modified hollow glass microspheres;
[0050] It should be noted that the inventors found in the improvement process that only depositing a titanium dioxide coating layer on the surface of the hollow glass microsphere for surface modification can improve the reflectivity to a certain extent, but the actual improvement effect of the light reflectivity is still not ideal. The inventors further found that the reason why the hollow glass microsphere cannot significantly improve the light emissivity after only depositing a titanium dioxide coating layer on the surface of the hollow glass microsphere is that the titanium dioxide coating layer deposited on the surface of the hollow glass microsphere is uneven, so the hollow glass microsphere coated with titanium dioxide is mixed with nano-silica sol and subjected to stirring treatment, so as to further polish the titanium dioxide layer coated on the surface of the hollow glass microsphere by the nano-silica sol, which can significantly improve the light reflectivity, so that the hollow glass microsphere has the dual heat insulation mechanism of ideal barrier heat insulation and reflective heat insulation, and the heat insulation effect is more excellent.
[0051] It should be further noted that the inventors consider that the traditional mechanical polishing treatment can make the titanium dioxide coating layer deposited on the surface of the hollow glass microsphere more flat, but at the same time, the titanium dioxide coating layer is also abraded, which reduces the content of the titanium dioxide coating layer. Therefore, the nano-silica sol is preferably used as a polishing agent to polish the hollow glass microsphere coated with titanium dioxide. The nano-silica sol is a water dispersion liquid containing a large number of suspended nano-SiO2 particles, and the nano-silica sol is generally obtained by hydrolysis of low-cost sodium silicate in industry, so the raw material cost is low and the process is simple, and therefore the cost is much lower than that of other oxide nano-materials. The particle size of the nano-SiO2 particles in the nano-silica sol supplied on the market is generally 5-15 nm, and the content of the nano-SiO2 particles is 25%-41%. In order to ensure the polishing effect, the polishing treatment is preferably achieved in the following manner: the hollow glass microsphere coated with titanium dioxide is mixed with the nano-silica sol, and then stirred at a stirring rate of 500-1200 r / min for 15-150 min to obtain the modified hollow glass microsphere.
[0052] In addition, the silica sol is also an excellent water-based inorganic film-forming material, which can be directly added to the coating, so that the modified hollow glass microsphere obtained by the above polishing treatment can be directly used as a raw material for preparing a water-based inorganic coating, thereby saving an additional process step and reducing the production cost. The modified hollow glass microsphere treated by the silica sol can also be used in the inorganic coating after being subjected to processes such as precipitation, filtration, washing and drying, but the inventors consider that the treatment cost is directly used as a raw material for preparing a water-based inorganic coating together with the silica sol used.
[0053] The application also provides a water-based inorganic coating, which is composed of the following components by weight:
[0054] The above modified hollow glass microbeads 0.5-20 parts, alkali metal silicate 25-40 parts, water 20-30 parts, wetting dispersant 0.2-0.8 parts, defoaming agent 0.2-1 parts, thickening agent 0.2-0.5 parts, leveling agent 0.2-0.5 parts, talc 6-10 parts, titanium dioxide 4-8 parts, heavy calcium carbonate powder 10-18 parts, dolomite powder 1-5 parts, emulsion 3-5 parts, film-forming aid 0.1-1 parts.
[0055] Among them, the present application greatly improves the toughness, water resistance and stability of the coating through the interaction with potassium silicate by dispersant, thickening agent, leveling agent, defoaming agent and other aids, while cooperating with a small amount of emulsion. The surface modified hollow glass microbeads are used as the main heat insulation filler in the inorganic coating, and the hollow glass microbeads have very low thermal conductivity and are a good barrier type heat insulation filler. The light reflection ability of the hollow glass microbeads is improved through surface modification. The prepared water-based inorganic heat insulation coating has the dual heat insulation mechanism of barrier heat insulation and reflection heat insulation, and has the advantages of high heat insulation, good weather resistance, strong wear resistance and fire resistance. The coating has excellent heat insulation and energy saving effect when applied to the wall surface of the building.
[0056] And the present application considers that the water-based inorganic coating with sodium silicate as the main film-forming material is easy to produce sodium salt precipitation, and the surface of the coating after construction is easy to appear "white frost" phenomenon. Lithium silicate is an excellent inorganic film-forming material, but due to the large-scale application of lithium batteries in the fields of transportation and energy storage in recent years, the market demand for lithium salt is huge, but the resources of lithium salt are very limited, which leads to the extremely high price of lithium salt at present. It is obviously not suitable to use it as a building coating raw material in an economic sense. Therefore, the inorganic coating with potassium silicate as the film-forming material has excellent comprehensive performance, and the coating surface will not have "white frost" phenomenon after construction, and has the characteristics of large market supply and low cost. The present application prepares a water-based inorganic coating containing surface modified hollow glass microbead filler with potassium silicate as the main film-forming material, which has excellent heat insulation performance. And the present application directly adds commercially available potassium silicate aqueous solution, and the modulus of the potassium silicate aqueous solution is not less than 2.5.
[0057] The emulsion used in the present application can be selected from one or more of domestic commercially available benzene propyl, pure propyl and silicon propyl emulsion.
[0058] And the preparation method of the above-mentioned water-based inorganic coating of the present application comprises the following steps:
[0059] S1, according to the following ratio, the prepared raw materials are weighed and prepared:
[0060] The above modified hollow glass microsphere 0.5-20 parts, alkali metal silicate 25-40 parts, water 20-30 parts, wetting dispersant 0.2-0.8 parts, defoaming agent 0.2-1 parts, thickening agent 0.2-0.5 parts, leveling agent 0.2-0.5 parts, talc 6-10 parts, titanium dioxide 4-8 parts, heavy calcium carbonate powder 10-18 parts, dolomite powder 1-5 parts, emulsion 3-5 parts, film-forming aid 0.1-1 parts;
[0061] S2, half of the amount of the thickening agent weighed above is placed in the water weighed above, and stirred at a stirring rate of 450-550 r / min for 10-15 min to uniformly disperse the thickening agent in the water to obtain solution A;
[0062] S3, half of the amount of the thickening agent weighed above is placed in the water weighed above, and stirred at a stirring rate of 450-550 r / min for 10-15 min to uniformly disperse the thickening agent in the water to obtain solution B;
[0063] S4, the talc, titanium dioxide, heavy calcium carbonate powder, and dolomite powder weighed above are sequentially placed in the solution B to uniformly disperse the talc, titanium dioxide, heavy calcium carbonate powder, and dolomite powder at a stirring rate of 1100-1300 r / min for 30-60 min to obtain solution C;
[0064] S5, the emulsion weighed above is placed in the solution C and stirred at a stirring rate of 1100-1300 r / min for 10 min, then the alkali metal silicate is added and stirred at a stirring rate of 950-1050 r / min for 8-12 min, and then the modified hollow glass microsphere is added and stirred at a stirring rate of 150-250 r / min for 15-25 min to obtain solution D;
[0065] S6, the remaining half of the amount of the thickening agent and half of the amount of the defoaming agent are added to the solution D and stirred at a stirring rate of 150-250 r / min for 10-20 min to obtain the water-based inorganic paint.
[0066] Example 1
[0067] The present embodiment provides a modified hollow glass microsphere, and a preparation method thereof is as follows:
[0068] 1) 1.0 kg of hollow glass microspheres is placed in 10 L of anhydrous ethanol to obtain solution A;
[0069] 2) 900 mL of tetrabutyl titanate is placed in 1800 mL of anhydrous ethanol, and after being uniformly mixed, solution B is obtained;
[0070] 3) 2250 mL of anhydrous ethanol and 450 mL of water are uniformly mixed to form solution C;
[0071] 4) Stir solution A at a stirring rate of 400 r / min for 20 min to make the hollow glass microspheres uniformly dispersed. Then, under stirring, solution B and solution C are simultaneously added to solution A at a dropping rate of about 30 mL / min, and tetrabutyl titanate immediately undergoes hydrolysis reaction in solution A and forms a titanium hydroxide coating layer on the surface of the hollow glass microspheres. After the addition of solution B and solution C is completed, stirring is continued for 1 h to make the hydrolysis reaction sufficient. Then, solid-liquid separation is performed, and the obtained precursor material is washed and dried to obtain a precursor material;
[0072] 5) The precursor material is heat-treated at 450 °C for 1.5 h to convert the titanium hydroxide coating layer precursor into titanium dioxide, thereby obtaining titanium dioxide-coated hollow glass microspheres with a weight of about 1.2 kg;
[0073] 6) The 1.2 kg of titanium dioxide-coated hollow glass microspheres obtained above are added to 3.3 kg of JN-830 type nano-silica sol polishing agent, and stirring is performed at a stirring rate of 600 r / min for 60 min to obtain modified hollow glass microspheres.
[0074] Example 2
[0075] This example provides a modified hollow glass microsphere, and a preparation method thereof is as follows:
[0076] 1) 1.2 kg of hollow glass microspheres are placed in 10 L of anhydrous ethanol to obtain solution A;
[0077] 2) 900 mL of tetrabutyl titanate is placed in 1800 mL of anhydrous ethanol, and solution B is obtained after mixing;
[0078] 3) 2250 mL of anhydrous ethanol and 450 mL of water are mixed to form solution C;
[0079] 4) Solution A is stirred at a stirring rate of 450 r / min for 18 min to make the hollow glass microspheres uniformly dispersed. Then, under stirring, solution B and solution C are simultaneously added to solution A at a dropping rate of about 30 mL / min, and tetrabutyl titanate immediately undergoes hydrolysis reaction in solution A and forms a titanium hydroxide coating layer on the surface of the hollow glass microspheres. After the addition of solution B and solution C is completed, stirring is continued for 0.8 h to make the hydrolysis reaction sufficient. Then, solid-liquid separation is performed, and the obtained precursor material is washed and dried to obtain a precursor material;
[0080] 5) The precursor material is heat-treated at 550 °C for 1 h to convert the titanium hydroxide coating layer precursor into titanium dioxide, thereby obtaining titanium dioxide-coated hollow glass microspheres with a weight of about 1.4 kg;
[0081] 6) The 1.4 kg of hollow glass microspheres coated with titanium dioxide obtained above is added to 3.6 kg of JN-830 type nano-silica sol polishing agent, and stirred at a stirring rate of 800 r / min for 50 min to obtain modified hollow glass microspheres.
[0082] Example 3
[0083] The present example provides a modified hollow glass microsphere, and a preparation method thereof is as follows:
[0084] 1) 1.1 kg of hollow glass microspheres is placed in 10 L of anhydrous ethanol to obtain solution A;
[0085] 2) 900 mL of tetrabutyl titanate is placed in 1800 mL of anhydrous ethanol, and solution B is obtained after mixing uniformly;
[0086] 3) 2250 mL of anhydrous ethanol and 450 mL of water are mixed uniformly to form solution C;
[0087] 4) Solution A is stirred at a stirring rate of 300 r / min for 25 min to make the hollow glass microspheres in a uniformly dispersed state. Then, solution B and solution C are simultaneously added dropwise to solution A at a dropwise adding rate of about 30 mL / min under stirring, and tetrabutyl titanate is hydrolyzed in solution A and forms a titanium hydroxide coating layer on the surface of the hollow glass microspheres. After the dropwise adding of solution B and solution C is completed, stirring is continued for 1.2 h to make the hydrolysis reaction sufficient. Then, solid-liquid separation is performed, and the precursor material is obtained after washing and drying;
[0088] 5) The precursor material is heat treated at 500 ℃ for 1 h to convert the titanium hydroxide coating layer precursor into titanium dioxide, and thus hollow glass microspheres coated with titanium dioxide are obtained, and the weight thereof is about 1.3 kg;
[0089] 6) The 1.3 kg of hollow glass microspheres coated with titanium dioxide obtained above is added to 3 kg of JN-830 type nano-silica sol polishing agent, and stirred at a stirring rate of 650 r / min for 55 min to obtain modified hollow glass microspheres.
[0090] The modified hollow glass microspheres prepared in Examples 1-3 of the present application can be directly used for preparation of inorganic coatings, and the following examples apply the modified hollow glass microspheres to water-based inorganic coatings.
[0091] Example 4
[0092] The present example provides a water-based inorganic coating, and the water-based inorganic coating is prepared by the following steps:
[0093] S1, each preparation raw material is weighed according to the following weight ratio for standby:
[0094] The modified hollow glass microsphere-nanosilica sol mixture prepared in Example 1 1.2 kg, potassium silicate aqueous solution 5.6 kg, water 4.5 kg, wetting dispersant 0.1 kg, defoaming agent 0.06 kg, thickening agent 0.04 kg, leveling agent 0.04 kg, talc 2 kg, titanium white 1 kg, heavy calcium carbonate powder 3.3 kg, dolomite powder 0.5 kg, emulsion 0.6 kg, film-forming aid 0.05 kg;
[0095] S2, 0.02 kg of thickening agent was taken and added to 4.5 kg of water weighed, stirred at a speed of 500 r / min for 15 min to obtain solution A;
[0096] S3, 0.1 kg of wetting dispersant, 0.05 kg of film-forming aid, 0.04 kg of leveling agent, and 0.03 kg of defoaming agent were added to the solution A, stirred at a speed of 800 r / min for 10 min to obtain solution B;
[0097] S4, 2 kg of talc, 1 kg of titanium white, 3.3 kg of heavy calcium carbonate powder, and 0.5 kg of dolomite powder were sequentially added to the above-mentioned solution B, stirred at a speed of 1200 r / min for 40 min to obtain solution C;
[0098] S5, 0.6 kg of styrene-acrylic emulsion was added to the solution C, stirred at a speed of 1200 r / min for 10 min, then 5.6 kg of potassium silicate was added, stirred at a speed of 1000 r / min for 10 min, and then the above-mentioned 1.2 kg of modified hollow glass microsphere-nanosilica sol mixture was uniformly mixed, stirred at a speed of 200 r / min for 15 min to obtain solution D;
[0099] S6, the remaining 0.02 kg of thickening agent and the remaining 0.03 kg of defoaming agent were added to the solution D, stirred at a speed of 200 r / min for 15 min to obtain the water-based inorganic paint.
[0100] Example 5
[0101] The present embodiment provides a water-based inorganic paint, and it is prepared by the following steps:
[0102] The modified hollow glass microsphere-nanosilica sol mixture prepared in Example 2 1.4 kg, potassium silicate aqueous solution 5.4 kg, water 4.3 kg, wetting dispersant 0.1 kg, defoaming agent 0.06 kg, thickening agent 0.04 kg, leveling agent 0.04 kg, talc 2 kg, titanium white 1 kg, heavy calcium carbonate powder 3.3 kg, dolomite powder 0.5 kg, emulsion 0.6 kg, film-forming aid 0.05 kg;
[0103] S2, 0.02 kg thickener was taken and added to 4.3 kg water weighed, stirred at a rate of 500 r / min for 15 min, to obtain solution A;
[0104] S3, 0.1 kg wetting dispersant, 0.05 kg film forming aid, 0.04 kg leveling agent, 0.03 kg defoaming agent were added to the solution A, stirred at a rate of 800 r / min for 10 min, to obtain solution B;
[0105] S4, 2 kg talc powder, 1 kg titanium dioxide, 3.3 kg heavy calcium carbonate powder, 0.5 kg dolomite powder were sequentially added to the above solution B, stirred at a rate of 1200 r / min for 40 min, to obtain solution C;
[0106] S5, 0.6 kg styrene-acrylic emulsion was added to the solution C, stirred at a rate of 1200 r / min for 10 min, then 5.4 kg potassium silicate was added, stirred at a rate of 1000 r / min for 10 min, then the above 1.4 kg modified hollow glass beads-nanosilica sol mixed solution was mixed, stirred at a rate of 200 r / min for 15 min, to obtain solution D;
[0107] S6, the remaining 0.02 kg thickener and the remaining 0.03 kg defoaming agent were added to the solution D, stirred at a rate of 200 r / min for 10 min, to obtain the aqueous inorganic paint.
[0108] Example 6
[0109] The example provides an aqueous inorganic paint, and it is prepared by the following steps:
[0110] The modified hollow glass beads-nanosilica sol mixed solution 1.3 kg prepared in Example 3, potassium silicate aqueous solution 5.5 kg, water 4.4 kg, wetting dispersant 0.1 kg, defoaming agent 0.06 kg, thickener 0.04 kg, leveling agent 0.04 kg, talc powder 2 kg, titanium dioxide 1 kg, heavy calcium carbonate powder 3.3 kg, dolomite powder 0.5 kg, emulsion 0.6 kg, film forming aid 0.05 kg;
[0111] S2, 0.02 kg thickener was taken and added to 4.3 kg water weighed, stirred at a rate of 500 r / min for 15 min, to obtain solution A;
[0112] S3, 0.1 kg wetting dispersant, 0.05 kg film forming aid, 0.04 kg leveling agent, 0.03 kg defoaming agent were added to the solution A, stirred at a rate of 800 r / min for 10 min, to obtain solution B;
[0113] S4, 2 kg talcum powder, 1 kg titanium white powder, 3.3 kg heavy calcium carbonate powder, 0.5 kg dolomite powder were added into the above solution B in turn, and stirred at a speed of 1200 r / min for 40 min to obtain solution C;
[0114] S5, 0.6 kg of styrene-acrylic emulsion was added into the solution C, and stirred at a speed of 1200 r / min for 10 min, then 5.5 kg of potassium silicate was added, and stirred at a speed of 1000 r / min for 10 min, then the above 1.3 kg of modified hollow glass microsphere-nanosilica sol mixed solution was added and mixed, and stirred at a speed of 200 r / min for 15 min to obtain solution D;
[0115] S6, the remaining 0.02 kg thickening agent and the remaining 0.03 kg defoaming agent were added into the solution D, and stirred at a speed of 200 r / min for 15 min to obtain the water-based inorganic coating.
[0116] Comparative Example 1
[0117] The difference between this comparative example and Example 2 is only that:
[0118] The hollow glass microspheres in this comparative example are not modified, i.e. ordinary hollow glass microspheres.
[0119] Comparative Example 2
[0120] The difference between this comparative example and Example 2 is only that:
[0121] The hollow glass microspheres in this comparative example are not polished, i.e. hollow glass microspheres coated with titanium dioxide on the surface.
[0122] Comparative Example 3
[0123] The difference between this comparative example and Example 5 is only that:
[0124] The ordinary hollow glass microspheres in this comparative example are used as the heat insulation filler.
[0125] Comparative Example 4
[0126] The difference between this comparative example and Example 5 is only that:
[0127] The hollow glass microspheres coated with titanium dioxide on the surface in this comparative example are used as the heat insulation filler.
[0128] Test Part
[0129] (I) Visible light and near-infrared light reflection performance test
[0130] The visible light and near-infrared light reflection performance of the water-based inorganic coatings of Examples 4-6 and Comparative Examples 3 and 4 were tested, and the test results are shown in Table 1. Figure 1
[0131] Figure 1 As can be seen, the reflectivity of the water-based inorganic coatings of Examples 4-6 is significantly higher than that of Comparative Examples 3 and 4, and the reflectivity of the coating of Comparative Example 4 is also significantly higher than that of Comparative Example 3. This shows that the improvement in the reflectivity of the water-based inorganic coating of the present application is due to the polishing treatment of the hollow glass microspheres coated with titanium dioxide on the surface.
[0132] (B) Thermal insulation performance test
[0133] The water-based inorganic coatings of Examples 4-6 and Comparative Examples 3 and 4 were tested for their main properties, such as thermal insulation, weather resistance, water resistance, alkali resistance, wear resistance, fire resistance, etc.
[0134] The thermal insulation performance test method was as follows: five identical sealed foam boxes with a size of 300mm x 300mm x 300mm were used, and a thermocouple was connected inside to detect the temperature. A glass plate with a thickness of 3mm was used instead of a foam plate on the top of the box, and the corresponding water-based inorganic coatings of Examples 4, 5, 6, Comparative Example 3 and Comparative Example 4 were coated on the surface of the glass plate with a coating thickness of 0.6mm. After the coating was dried, the box was placed in a refrigerator to make the temperature inside the box about 10℃. Then, an infrared heating lamp was used to irradiate and warm the top glass of the box at a distance of 300mm. The entire test device was placed in a self-made large-size glass sealed heat preservation room. After the infrared heating lamp was irradiated for 0.5h, the direct temperature of the inside of the box and the 15mm part above the coating was detected, and the thermal insulation temperature difference or thermal insulation temperature difference was calculated.
[0135] The test results are shown in Table 1, and from Table 1 it can be seen that the thermal insulation effect of the water-based inorganic coatings of Examples 4-6 is significantly better than that of Comparative Examples 3 and 4, which shows that the modified hollow glass microspheres prepared in the present application have better improvement effect on the thermal insulation performance of the coating than ordinary unmodified hollow glass microspheres and hollow glass microspheres coated with titanium dioxide on the surface without polishing treatment. In addition, the water-based inorganic coatings of Examples 4-6 and Comparative Examples 3 and 4 all have excellent weather resistance, water resistance, alkali resistance, wear resistance and fire resistance. Among them, the weather resistance, water resistance, alkali resistance and wear resistance were tested according to the test method in JG / T 26-2002 External Wall Inorganic Building Coatings; and the fire resistance was tested according to the test method in GB 8624-2012 Classification of Combustion Performance of Building Materials and Products.
[0136] Table 1 Thermal insulation performance test results of Examples 4-6 and Comparative Examples 3-4
[0137]
[0138] Obviously, the above embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without making creative labor fall within the protection scope of the present application.
Claims
1. A method for producing a modified hollow glass microsphere, characterized by, The method comprises the following steps: Step 1, depositing a layer of titanium dioxide on the surface of hollow glass beads to obtain hollow glass beads coated with titanium dioxide; Step 2, mixing the hollow glass beads coated with titanium dioxide with nano-silica sol and performing stirring treatment to obtain the modified hollow glass beads.
2. The production method according to claim 1, wherein The particle size of the hollow glass beads is 80-500 mesh.
3. The production method according to claim 1, wherein The solid content of nano-SiO2 in the nano-silica sol is 28-32%, and the particle size of nano-SiO2 is 5-15 nm.
4. The production method according to claim 1, wherein The stirring rate of the stirring treatment is 500-1500 r / min, and the stirring time is 1-120 min.
5. The production method according to claim 1, wherein The hollow glass beads coated with titanium dioxide are obtained by the following steps: 1) mixing tetrabutyl titanate and anhydrous ethanol in a volume ratio of 1:1.5-2.5 to obtain solution A; mixing anhydrous ethanol and water in a volume ratio of 4.5-5.5:1 to obtain solution B; dispersing the hollow glass beads in anhydrous ethanol to obtain solution C; wherein the content of the hollow glass beads in the solution C is 1%-30%; 2) under the action of stirring, simultaneously adding the solution A and the solution B into the solution C and mixing uniformly, after the addition is completed, continuing to stir for 1-2 h, and then performing solid-liquid separation, washing and drying to obtain a precursor material; 3) heat-treating the precursor material at 350-650 ℃ for 0.5-1.5 h to convert the coating layer precursor material titanium hydroxide into titanium dioxide, and then obtaining the hollow glass beads coated with titanium dioxide.
6. The modified hollow glass beads prepared by the preparation method of any one of claims 1-5.
7. Use of the modified hollow glass microspheres according to claim 6 for the preparation of water-based inorganic coatings, characterized by the fact that, The modified hollow glass beads are used as thermal insulation fillers.
8. An aqueous inorganic coating material, characterized by The composition comprises the following components by weight: 0.5-20 parts of the modified hollow glass beads of claim 6, 25-40 parts of alkali metal silicate, 20-30 parts of water, 0.2-0.8 parts of wetting dispersant, 0.2-1 part of defoaming agent, 0.2-0.5 parts of thickening agent, 0.2-0.5 parts of leveling agent, 6-10 parts of talc, 4-8 parts of titanium dioxide, 10-18 parts of heavy calcium carbonate powder, 1-5 parts of dolomite powder, 3-5 parts of emulsion, and 0.1-1 part of film-forming aid.
9. The aqueous inorganic coating of claim 8, wherein, The alkali metal silicate is potassium silicate aqueous solution.
10. A method for producing the aqueous inorganic coating material according to claim 8, characterized by, The method comprises the following steps: S1, according to the following ratio, weighing each preparation raw material, and standby: 0.5-20 parts of the modified hollow glass beads of claim 5, 25-40 parts of alkali metal silicate, 20-30 parts of water, 0.2-0.8 parts of wetting dispersant, 0.2-1 part of defoaming agent, 0.2-0.5 parts of thickening agent, 0.2-0.5 parts of leveling agent, 6-10 parts of talc, 4-8 parts of titanium dioxide, 10-18 parts of heavy calcium carbonate powder, 1-5 parts of dolomite powder, 3-5 parts of emulsion, and 0.1-1 part of film-forming aid; S2, placing half of the weighed thickening agent in the weighed water, stirring at a stirring rate of 450-550 r / min for 10-15 min, and uniformly dispersing the thickening agent in the water to obtain solution A; S3, half of the thickening agent weighed above is put into the water weighed above, and stirred at a stirring rate of 450-550 r / min for 10-15 min, so that the thickening agent is uniformly dispersed in the water to obtain solution B; S4, the talc, titanium dioxide, heavy calcium carbonate powder and dolomite powder weighed above are sequentially put into the solution B, and stirred at a stirring rate of 1100-1300 r / min for 30-60 min, so that the talc, titanium dioxide, heavy calcium carbonate powder and dolomite powder are uniformly dispersed to obtain solution C; S5, the emulsion weighed above is put into the solution C, and stirred at a stirring rate of 1100-1300 r / min for 10 min, then the alkali metal silicate is added and stirred at a stirring rate of 950-1050 r / min for 8-12 min, then the modified hollow glass microsphere above is added and stirred at a stirring rate of 150-250 r / min for 15-25 min to obtain solution D; S6, the remaining half of the thickening agent and half of the defoaming agent are added into the solution D, and stirred at a stirring rate of 150-250 r / min for 10-20 min to obtain the water-based inorganic paint.