Modified functional filler, inorganic coating capable of improving floating during construction and preparation method of inorganic coating

Abstract

The invention discloses a modified functional filler, an inorganic coating capable of improving construction floating and a preparation method of the inorganic coating, and belongs to the technical field of inorganic coatings. The inorganic coating capable of improving floating during construction is a water-based inorganic building interior wall coating which is not prone to floating, easy to construct and easy to deliver, and floating resistance is jointly achieved mainly through synergistic compounding of the modified functional filler and the matting material in combination with optimal design of other components in the formula. The inorganic coating disclosed by the invention forms a film by using an inorganic film-forming substance, can be compounded with a small amount of organic synthetic resin emulsion or organic-inorganic hybrid emulsion, and can also be used as a pure inorganic system. And under the condition of local missed coating of the primer or the existence of brushing and roller construction difference, the floating phenomenon can still be obviously inhibited, the color difference is avoided, and excellent construction adaptability is shown.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of inorganic coatings, and particularly relates to a modified functional filler, an inorganic coating capable of improving construction bloom and a preparation method thereof. BACKGROUND

[0002] The existing inorganic interior wall coating for buildings generally uses alkali metal silicate or silica sol as the main film-forming binder, can be supplemented with a small amount of high molecular organic matter, and is matched with pigments, fillers and various additives, and is applied to the surface of the interior wall of the building by brushing or rolling.

[0003] The inorganic coating and the latex paint belong to the same water-based system, and there is no essential difference in the construction method and environmental requirements, and they can be applied by rolling or spraying. However, the film-forming mechanisms of the two are completely different, resulting in that the construction difficulty of the inorganic interior wall coating for buildings is significantly higher than that of the traditional latex paint.

[0004] Firstly, the film-forming substance in the inorganic coating is a small molecular inorganic silicate, which has strong permeability to the putty base layer. If the primer is not uniformly coated or is locally missed, the absorption amount of the inorganic coating topcoat will be different; after drying, the gloss, whiteness and thickness of the coating film will be uneven, etc. Secondly, this unevenness appears as a visual defect of light and shade under side light, i.e. the so-called "bloom"; when the product is tinted, the above-mentioned defects will further enlarge the color difference.

[0005] The inorganic interior wall coatings for buildings sold on the market generally have the common problems of high construction difficulty and easy bloom of the topcoat. Therefore, it is urgent to optimize the formula to solve the bloom phenomenon caused by the missing of the primer or the differences in brushing and rolling construction, so as to improve the construction adaptability of the inorganic interior wall coating for buildings and promote the overall technical progress of the industry. SUMMARY

[0006] The present application aims to overcome the poor construction adaptability of the existing water-based inorganic interior wall coating for buildings, especially to solve the bloom and color difference problems caused by the missing of the primer and the differences in brushing and rolling construction and different construction methods (brushing / rolling) of the topcoat, and to provide a water-based inorganic interior wall coating for buildings which is not easy to bloom, easy to construct and easy to deliver, specifically a modified functional filler, an inorganic coating capable of improving construction bloom and a preparation method thereof.

[0007] The inorganic coating of the present application is formed by inorganic film-forming substances, can be compounded with a small amount of organic synthetic resin emulsion or organic-inorganic hybrid emulsion, and can also be used as a pure inorganic system (without adding any organic synthetic resin emulsion). Under the conditions of the missing of the primer in some areas, the differences in brushing and rolling construction and different construction methods of the topcoat, the bloom phenomenon can be significantly inhibited and color difference can be avoided, and excellent construction performance is shown.

[0008] The present application relates to a kind of modified functional fillers and preparation method thereof, and the application relates to the field of inorganic building interior wall coating. (1) the local gloss difference and color difference of finish caused by primer missing coating; (2) the gloss unevenness and color difference of finish caused by different brushing and rolling construction methods.

[0009] To solve the above problems, the present application realizes by the following technical solutions: The first application object of the present application is to provide a preparation method of modified functional fillers, comprising the following preparation steps: S1. Particle size control of hollow microspheres (HGMs): Select hollow microspheres with a particle size range of 25-35 μm; S2. Surface chemical bonding modification: The hollow microspheres of step S1 are subjected to frequency ultrasonic treatment in a dynamic pH ethanol solution; then 3-5 wt% of silane coupling agent based on the total weight is added and treated for 10 min, and then 1-2 wt% of titanate coupling agent based on the total weight is added and treated for 20 min; S3. Core-shell structure design: After the reaction of step S2 is completed, dry at a temperature of 80°C, then treat at 120°C for 2 h under the protection of nitrogen to form a Si-O-Si / Ti-O-Si double coupling layer, and obtain modified hollow microspheres; Disperse the obtained modified hollow microspheres in a precursor solution, adjust pH to 4-5, and stir at a temperature of 50°C for 30 min of hydrolysis; add ethyl silicate / ethanol solution dropwise, adjust pH to 9-10, and react at a temperature of 60°C for 1 h to form an SiO2 outer layer; then use microwave-assisted drying for 10 min; microwave-assisted drying has lower breakage rate than traditional oven drying, and the breakage rate is significantly reduced by 15-20%; Finally, calcine at a temperature in the range of 400-500°C for 1 h to densify the shell layer; after the reaction is completed, the modified functional fillers are obtained. Compared with traditional modified microspheres, the compression strength of the obtained modified functional fillers is increased by 2-3 times, the thermal conductivity is lower, the alkali resistance is stronger, and the fillers are more suitable for use in systems with higher pH. The fillers are easy to form strong bonding with substrate materials, increase chemical stability, and improve dispersion performance.

[0010] The preparation method of the functional fillers further optimizes as follows:

[0011] ​The dynamic pH in the step S2 is linearly changed between 5.0 and 6.0, and the frequency conversion ultrasonic treatment program is 40 kHz / 200 W to 28 kHz / 150 W. The microwave-assisted drying treatment power is 150-250 W, 60±5 DEG C, and the drying time is 20-30 min.

[0012] The further optimization of the functional filler preparation method is as follows: The dynamic pH is realized by an acetic acid-sodium acetate buffer system. The frequency conversion linear change of the frequency conversion ultrasonic treatment program is 5 W / min.

[0013] The further optimization of the functional filler preparation method is as follows: In the step S3, The solid-liquid weight ratio of the modified hollow microspheres to the precursor solution is 1:10-20. The precursor solution is a solution obtained by dissolving aluminum isopropoxide and acetylacetone in an ethanol solution; the molar ratio of aluminum isopropoxide to acetylacetone is 1:1-1.5; 1 mol of aluminum isopropoxide is dissolved in 120 mL of ethanol. The ethyl silicate / ethanol solution is obtained by dissolving ethyl silicate in an ethanol solution, and the volume ratio of ethyl silicate to ethanol solution is 1:3-5.

[0014] The further optimization of the functional filler preparation method is as follows: The 25-35 mu m hollow microspheres in the step S1 are screened by the following steps: A. Raw material pretreatment: The original hollow glass microspheres with a particle size of 5-50 mu m and a density of 0.5-0.6 g / cm 3 are subjected to density gradient centrifugation by using a mixed solution of ethanol / water with a volume ratio of 7:3. B. Classification process: B1. Coarse control by using a vibrating screen: The upper screen is selected to be 400 mesh (38 mu m), and the hollow microspheres larger than 38 mu m are removed. The lower screen is selected to be 500 mesh (25 mu m), and the hollow microspheres smaller than 25 mu m are removed. The 25-38 mu m hollow microspheres are obtained as raw materials. B2. Density gradient centrifugation for fine screening: The density gradient liquid of ethanol / water is configured, and the density range is 0.4-0.6 g / cm 3 ; the density interval is divided into 5 layers: 0.40 g / cm 3 , 0.45 g / cm 30.50 g / cm 3 0.55 g / cm 3 0.60 g / cm 3 ; centrifugal conditions are 2000 rpm (350 g), and the hollow microspheres with a density range of 0.45-0.55 g / cm 3 are collected, that is, the 25-35 μm hollow microspheres are obtained.

[0015] The second inventive purpose of the present application is to provide a modified functional filler prepared by the preparation method described above. The second inventive purpose of the present application is to provide a modified functional filler prepared by the preparation method described above.

[0016] The third inventive purpose of the present application is to provide an inorganic coating capable of improving the blooming during construction. The third inventive purpose of the present application is to provide an inorganic coating capable of improving the blooming during construction. Thickening agent 1-10 parts, dispersing agent 10-50 parts, pH adjusting agent 0-2 parts, defoaming agent 2-10 parts, titanium white 50-200 parts, calcite powder 100-200 parts, the modified functional filler described above 10-50 parts, matt material 30-50 parts, water 100-400 parts, emulsion 0-90 parts, silane modified silica sol 0-220 parts, alkali silicate 0-100 parts; the sum of the weight parts of all components is 1000 parts.

[0017] The main film-forming substance of the inorganic coating is small molecule inorganic silicate, which has extremely strong penetration capacity to the putty base layer. The modified functional filler used in the present application can significantly react with the small molecule silicate, thereby effectively relieving the phenomenon of uneven absorption of the finish paint.

[0018] The further optimization of the inorganic coating capable of improving the blooming during construction described in the present application is that: The matt material is one or a combination of several of natural matt powder, synthetic matt powder and diatomite matt material; preferably, the matt material is synthetic matt powder; The matt material used in the present application is compounded with the modified functional filler described above, and the two play the following roles in cooperation: (1) The modified hollow microspheres in the modified functional filler significantly improve the light extinction efficiency by multiple internal light refraction, and the high chemical inertness ensures long-term stability in the high-alkaline inorganic system, making up for the instability defect of conventional matt materials in the inorganic system; (2) The matt material gives the system moderate thixotropy, and improves the construction hand feeling; the hollow microspheres modified by core-shell can reduce the internal particle friction and optimize the leveling property of spray and roll coating, avoiding the orange peel or brush marks caused by the matt material; (3) The two balance the hardness and toughness of the paint film together, prolong the durable life of the light extinction effect, and make the coating have the dual advantages of easy construction and long-acting light extinction.

[0019] Further optimization of the inorganic coating capable of improving construction bloom described in the present application is: It includes one or several features in combination: The basic silicate is one or a combination of potassium silicate, lithium silicate; The dispersant is one or a combination of high molecular polymer dispersant, anionic copolymer dispersant; The emulsion is one or a combination of acrylic emulsion, organic-inorganic hybrid emulsion; The titanium white is rutile titanium white, rutile titanium white treated with silicon, aluminum inorganic surface treatment, organic surface treatment; The calcite powder is a powder prepared by crushing natural calcite ore, wherein the mass percentage content of calcium carbonate is ≥97%, the fineness is 200 mesh or 500 mesh, and the specific performance indicators thereof should meet: the ore source is single, the mass percentage content of Mg is ≤2%, and the water solution conductivity is <8 s / m; Calcium carbonate and basic silicate have good stability under normal storage conditions, and the chemical reaction rate between them is within an acceptable range. However, natural calcite ore often contains divalent or trivalent metal impurities such as magnesium, iron and aluminum, and the above high valence metal ions are easy to agglomerate with basic silicate, which leads to a sharp increase in system viscosity, and then affects the preparation and construction of the coating. Therefore, the high-purity calcite powder selected by ore selection is used in the technical solution to inhibit side reactions and ensure the storage stability of the system.

[0020] The thickening agent is one or a combination of cellulose ether and its derivatives, HEC, and MHEC; In the organic emulsion system, the pH regulator is one or a combination of organic amine, ammonia, sodium hydroxide, and potassium hydroxide; if it is an organic-inorganic hybrid emulsion or a pure inorganic system, 0.2-0.5% of the organic-inorganic hybrid emulsion or the basic silicate is used as the pH regulator; If a conventional organic emulsion is used in the system, a pH regulator needs to be used. If an organic-inorganic hybrid emulsion or a pure inorganic system is used, a small part (0.2-0.5% of the total weight) of the organic-inorganic hybrid emulsion or the basic silicate is used as the pH regulator.

[0021] The defoaming agent is one or a combination of mineral oil defoaming agent, silicone defoaming agent, and polyether defoaming agent.

[0022] The fourth invention purpose of the present application is: Provided is a preparation method of the inorganic coating capable of improving construction bloom described above, which includes the following preparation steps: s1. The thickener, dispersant, pH regulator, part of water are dispersed at high speed under high-speed stirring condition according to the proportion of the formula, to obtain a high-viscosity dispersion slurry; then the calcite powder, titanium white, modified functional filler and matting material are put in, and continue to stir at high speed until the sample is below the specified fineness (such as 60 μm); s2. The emulsion, silane modified silica sol, alkali silicate are added to the sample obtained in step s1, and further dispersed under high-speed stirring; s3. The defoaming agent and the remaining part of water are added to the sample after step s2 and mixed uniformly to prepare the inorganic coating capable of improving the blooming during construction.

[0023] The inorganic coating capable of improving the blooming during construction of the present application is a water-based inorganic building coating which is not prone to blooming and has excellent construction performance. The film-forming main body is inorganic resin, and a small amount of organic synthetic resin emulsion or organic-inorganic hybrid emulsion can be compounded, or the film-forming can be completely inorganic without emulsion.

[0024] The anti-blooming performance is mainly realized by the synergistic compounding of the modified functional filler and the matting material, and the optimization design of other components in the formula. BRIEF DESCRIPTION OF DRAWINGS

[0025] Fig. 1 The construction effect diagram of the coating corresponding to Comparative Example 1 (left: with primer, right: without primer; the periphery is brushed, and the rest is rolled).

[0026] Fig. 2 The construction effect diagram of the coating corresponding to Comparative Example 2 (left: with primer, right: without primer; the periphery is brushed, and the rest is rolled).

[0027] Fig. 3 The construction effect diagram of the coating corresponding to Example 1 (left: with primer, right: without primer; the periphery is brushed, and the rest is rolled).

[0028] Fig. 4 The construction effect diagram of the coating corresponding to Example 2 (left: with primer, right: without primer; the periphery is brushed, and the rest is rolled). DETAILED DESCRIPTION

[0029] In order to make the purpose, technical scheme and advantages of the present application more clear and explicit, the present application is described in detail below with specific examples. It should be understood that the specific examples described herein are only for the purpose of explaining the present application, and are not limited to the present application. Any simple improvement of the preparation method of the present application under the concept of the present application is within the protection scope of the present application. EXAMPLES

[0030] A preparation method of an inorganic coating capable of improving the blooming during construction, comprising the following preparation steps: s1. The thickening agent, dispersing agent, pH regulator, part of water are dispersed at high speed under high speed stirring condition according to the proportion of the formula, and a high viscosity dispersion slurry is obtained; then the calcite powder, titanium dioxide, modified functional filler and matting material are put in, and the stirring is continued until the sample reaches the specified fineness; s2. The emulsion, silane modified silica sol, alkali silicate are added to the sample obtained in step s1, and further dispersed under high speed stirring; s3. The defoaming agent and the remaining part of water are added to the sample after step s2, and mixed uniformly to prepare the inorganic coating capable of improving the construction bloom.

[0031] The more detailed selection of raw materials and preparation method are referred to the relevant part of the instruction manual.

[0032] The specific embodiment part also includes Example 2 and Comparative Examples 1-2.

[0033] The preparation methods of Examples 1-2 and Comparative Examples 1-2 are the same, and the main difference is that the specific raw materials and the amount used are different.

[0034] The raw materials and the amount used in Examples 1-2 and Comparative Examples 1-2 are shown in Table 1.

[0035] Table 1 Raw material composition table (parts by weight) of each example

[0036] In Examples 1-2 and Comparative Examples 1-2, the thickening agent is a cellulose thickening agent; the pH regulator is an organic amine pH regulator; the dispersing agent is a high molecular polymer dispersing agent; the defoaming agent is an organic silicon defoaming agent; the titanium dioxide is a rutile titanium dioxide, such as KOMO Chemicals titanium dioxide R902+; the calcite powder meets: mass percentage content ≥97%, calcite powder with fineness of 500 mesh, and the Mg content is below 2%, and the water solution conductivity is less than 8 s / m.

[0037] The main difference between Examples 1-2 and Comparative Examples 1-2 is the proportion of modified functional filler and matting material.

[0038] The raw materials not mentioned are the commonly used product raw materials of this component.

[0039] Table 2 Test results of the construction performance of the products of the examples and comparative examples of the application

[0040] According to Table 2 and Figs. 1-4It can be seen that the comparative example 1 is unqualified in terms of workability without using the modified functional filler and the matting material. The comparative example 2 is unqualified in terms of workability without using the modified functional filler and using only the matting material. The examples 1-2 are qualified in terms of workability.

[0041] Currently, almost all inorganic coatings on the market do not use the modified functional filler and the matting material at the same time, but only use a single matting material, so that the inorganic coating workability is difficult. The water-based inorganic coating of the present application has excellent workability, can realize primer leakage, and has no difference in visual brushing and roller coating, and does not "flower".

[0042] In summary, the above is only a preferred example of the present application, and does not limit the present application in any form; any slight changes, modifications and equivalent changes made by those skilled in the art within the scope of the technical solutions of the present application, using the disclosed technical content, are considered equivalent examples of the present application; at the same time, any equivalent changes, modifications and evolution of the above examples according to the essential technology of the present application are within the protection scope of the technical solutions of the present application.

[0043] The technical features of the above-described embodiments can be combined arbitrarily. In order to make the description concise, all possible combinations of the technical features in the above-described embodiments are not described, however, as long as the combinations of the technical features do not exist contradictory, they should be considered as the scope of the present disclosure.

[0044] The experimental methods not marked with specific conditions in the present application are usually according to the conventional conditions or according to the conditions suggested by the manufacturers.

[0045] The various optimization technical solutions in the present application can be combined with each other, unless otherwise specified.

[0046] Unless otherwise specified, the percentages and parts are mass percentages and mass parts.

[0047] The experimental methods not marked with specific conditions in the present application are usually according to the conventional conditions or according to the conditions suggested by the manufacturers.

[0048] The various raw materials, reagents, components used in the present application are commonly used corresponding raw materials in the art, unless otherwise specified.

[0049] Unless otherwise defined, all professional and scientific terms used herein have the same meaning as familiar to those skilled in the art. In addition, any method and material similar or equivalent to those described can be applied in the present application.

Claims

1. A method for preparing a modified functional filler, characterized in that: It includes the following preparation steps: S1. Particle size control of hollow microspheres: Hollow microspheres with a particle size range of 25–35 μm were selected; S2. Surface chemical bonding modification: The hollow microspheres from step S1 were subjected to frequency conversion ultrasonic treatment in a dynamic pH ethanol solution; then, 3-5 wt% of silane coupling agent was added and treated for 10 min, followed by 1-2 wt% of titanate coupling agent and treated for 20 min. S3. Core-shell structure design: After the reaction in step S2 is completed, the product is dried at 80°C and then treated at 120°C for 2 hours under nitrogen protection to form a Si-O-Si / Ti-O-Si double coupling layer, thus obtaining modified hollow microspheres. The obtained modified hollow microspheres were dispersed in a precursor solution, the pH was adjusted to 4-5, and the mixture was stirred and hydrolyzed at 50°C for 30 min. Ethyl silicate / ethanol solution was added dropwise, the pH was adjusted to 9-10, and the mixture was reacted at 60°C for 1 h to form an outer layer of SiO2. Then, microwave-assisted drying was performed for 10 min. Finally, the shell is calcined at a temperature range of 400-500℃ for 1 hour to densify it. After the reaction is complete, the modified functional filler is obtained.

2. The method for preparing the functional filler according to claim 1, characterized in that: In step S2, the dynamic pH changes linearly from 5.0 to 6.0, and the frequency conversion ultrasonic treatment program is 40kHz / 200W to 28kHz / 150W. The microwave-assisted drying process has a power of 150-250W, a temperature of 60±5℃, and a drying time of 20-30 minutes.

3. The method for preparing the functional filler according to claim 2, characterized in that: The dynamic pH is achieved through an acetate-sodium acetate buffer system; The frequency conversion linear change of the aforementioned frequency-converting ultrasonic processing program is 5W / min.

4. The method for preparing the functional filler according to claim 1, characterized in that: In step S3: The solid-liquid weight ratio of the modified hollow microspheres to the precursor solution is 1:10-20; The precursor solution is a solution obtained by dissolving aluminum isopropoxide and acetylacetone in an ethanol solution; the molar ratio of aluminum isopropoxide to acetylacetone is 1:1 to 1.5; 1 mol of aluminum isopropoxide corresponds to 120 mL of ethanol; The ethyl silicate / ethanol solution is prepared by dissolving ethyl silicate in an ethanol solution, with a volume ratio of ethyl silicate to ethanol solution of 1:3 to 5.

5. The method for preparing the functional filler according to claim 1, characterized in that: The 25-35 μm hollow microspheres in step S1 are screened through the following steps: A. Raw material pretreatment: A 7:3 volume ratio of ethanol / water was used to treat particles with a diameter of 5–50 μm and a density of 0.5–0.6 g / cm³. 3 Density gradient centrifugation was performed on the original hollow glass microspheres; B. Grading process: B1. Coarse control using a vibrating screen: The upper sieve is selected with a 400 mesh to remove hollow microspheres larger than 38μm; The lower sieve is selected with a 500 mesh to remove hollow microspheres smaller than 25μm; Hollow microspheres with a diameter of 25–38 μm were initially obtained; B2. Density gradient centrifugal sieving: Prepare a density gradient solution of ethanol / water with a density range of 0.4–0.6 g / cm³. 3 The density range is divided into 5 layers: 0.40 g / cm³ 3 0.45 g / cm 3 0.50 g / cm 3 0.55 g / cm 3 0.60 g / cm 3 Centrifugation conditions: 2000 rpm, 20 min; collected density range: 0.45–0.55 g / cm³. 3 Hollow microspheres, i.e., hollow microspheres of 25-35 μm, are obtained.

6. A modified functional filler, characterized in that: It is prepared by the preparation method described in any one of claims 1 to 5.

7. An inorganic coating that can improve the appearance of uneven coloring during application, characterized in that: It comprises the following components in parts by weight: Thickener 1-10 parts, dispersant 10-50 parts, pH adjuster 0-2 parts, defoamer 2-10 parts, titanium dioxide 50-200 parts, calcite powder 100-200 parts, modified functional filler as described in claim 6 10-50 parts, matting material 30-50 parts, water 100-400 parts, emulsion 0-90 parts, silane-modified silica sol 0-220 parts, basic silicate 0-100 parts; the sum of the weight parts of all components is 1000 parts.

8. The inorganic coating for improving application defects according to claim 7, characterized in that: The matting material is one or a combination of natural matting powder, synthetic matting powder, and diatomaceous earth matting material.

9. The inorganic coating for improving application defects according to claim 7, characterized in that: It includes one or more of the following features: The basic silicate is one or a combination of potassium silicate and lithium silicate; The dispersant is one or a combination of polymeric dispersants and anionic copolymer dispersants; The emulsion is one or a combination of acrylic emulsion and organic-inorganic hybrid emulsion; The titanium dioxide mentioned is rutile titanium dioxide, which is rutile titanium dioxide that has undergone inorganic surface treatment with silicon and aluminum, and organic surface treatment. The calcite powder is a powder obtained by crushing natural calcite ore, wherein the mass percentage content of calcium carbonate is ≥97%, the fineness is 200 mesh or 500 mesh, and the specific performance indicators it should meet are: the ore source is a single ore source, the mass percentage content of Mg is ≤2%, and the conductivity of its aqueous solution is <8 s / m. The thickener is a cellulose ether and its derivatives, specifically one or a combination of HEC and MHEC. In organic emulsion systems, the pH adjuster is one or a combination of organic amines, ammonia, sodium hydroxide, and potassium hydroxide; if it is an organic-inorganic hybrid emulsion or a pure inorganic system, then 0.2 to 0.5% of the total weight of the organic-inorganic hybrid emulsion or basic silicate is used as a pH adjuster. The defoamer is one or a combination of mineral oil defoamers, silicone defoamers, and polyether defoamers.

10. A method for preparing an inorganic coating as described in claim 7 that can improve the appearance of uneven coloring during construction, characterized in that: It includes the following preparation steps: s1. Thickener, dispersant, pH adjuster, and some water are dispersed at high speed under high-speed stirring according to the formula ratio to obtain a high-viscosity dispersion slurry; then calcite powder, titanium dioxide, modified functional filler and matting material are added, and high-speed stirring is continued until a sample with a fineness below the specified fineness is obtained. s2. Add emulsion, silane-modified silica sol and basic silicate to the sample obtained in step s1, and then disperse them thoroughly under high-speed stirring; s3. Add defoamer and the remaining water to the sample after step s2 and mix evenly to prepare the inorganic coating that can improve the color change during construction.

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