A coating composition, high-performance silica sol inorganic coating and preparation method thereof

Abstract

The present application relates to the field of inorganic coating technology and specifically discloses a coating composition, a high-performance silica sol inorganic coating, and a preparation method thereof. The coating composition of the present application comprises the following components by weight: 150-200 parts of organosilicon-modified silica sol AH-G3, 60-70 parts of styrene-acrylic emulsion, 3-5 parts of film-forming aid AH-16, 4-6 parts of thickener, 0.8-1.2 parts of anti-settling agent, 4-6 parts of dispersant, 390-450 parts of pigment and filler, 2-3 parts of modified cellulose, and 270-310 parts of water; the organosilicon-modified silica sol AH-G3 has a VOC content of <2.0 g / L, a particle size of 15-28 nm, and a pH of 9.5-11.0. The silica sol inorganic coating prepared from the coating composition of the present application can simultaneously take into account multiple properties such as Class A combustion performance, air permeability, water resistance, scrub resistance, stain resistance, resistance to artificial aging, and environmental protection, and has a good prospect for use.

Description

Technical Field

[0001] The present application relates to the technical field of inorganic coatings, and in particular to a coating composition, a high-performance silica sol inorganic coating and a preparation method thereof. Background Art

[0002] Architectural coatings are an important building material that not only beautifies a building's exterior but also protects its structure from environmental erosion, extending its service life. In recent years, with the improvement of people's living standards and the increasing demand for building quality, the architectural coatings industry has experienced rapid development. The increasing diversity of architectural styles has also placed higher demands on the performance of coatings.

[0003] There are many types of architectural coatings on the market today, but all of them struggle to balance multiple properties, significantly limiting their use. For example, traditional latex paints struggle to balance air permeability and scrub resistance. While water-based liquid inorganic coatings offer good air permeability and scrub resistance, they lack resistance to artificial aging and antifouling properties. While there have been reports of improving the artificial aging resistance of inorganic coatings by adding inorganic salts, this has also resulted in decreased air permeability and scrub resistance, creating a situation where one thing is compromised while the other is compromised.

[0004] Therefore, the development of an environmentally friendly inorganic coating that can achieve a balance in terms of Class A combustion performance, air permeability, water resistance, scrub resistance, resistance to artificial aging, and stain resistance is of great significance for the field of architectural coatings (especially in humid environments or places with high requirements for mildew resistance, environmental protection, and fire resistance). Summary of the Invention

[0005] In order to overcome the problem that existing coatings cannot take into account multiple properties such as air permeability, water resistance, scrub resistance, artificial aging resistance and environmental protection, the present application provides a coating composition, a high-performance silica sol inorganic coating and a preparation method thereof.

[0006] In a first aspect, the present application provides a coating composition, which adopts the following technical solution:

[0007] A coating composition comprising the following components in parts by weight: 150-200 parts of organosilicon-modified silica sol AH-G3, 60-70 parts of styrene-acrylic emulsion, 3-5 parts of film-forming aid AH-16, 4-6 parts of thickener, 0.8-1.2 parts of anti-settling agent, 4-6 parts of dispersant, 390-450 parts of pigments and fillers, 2-3 parts of modified cellulose, and 270-310 parts of water;

[0008] The organosilicon-modified silica sol AH-G3 has a VOC content of less than 2.0 g / L, a SiO2 content of 25±1%, a sodium oxide content of less than 0.3%, a viscosity at 25° C. of less than 6.5 mPa.s, a particle size of 15-28 nm, and a pH of 9.5-11.0.

[0009] The present application provides a coating composition. A high-performance silica sol inorganic coating prepared using the coating composition exhibits comprehensive advantages, including Class A combustion performance, excellent air permeability, water resistance, scrub resistance, stain resistance, resistance to artificial aging, and strong environmental friendliness. Specifically, the organosilicon-modified silica sol AH-G3 used in the present application is obtained by modifying silica sol (colloidal silica) with a special organosilicon modifier. It exhibits excellent compatibility with styrene-acrylic emulsions and effectively addresses the problem of conventional silica sols being prone to cross-linking after mixing with emulsions, resulting in increased viscosity and difficulty in use or storage. Furthermore, the organosilicon-modified silica sol AH-G3 can impart excellent air permeability, water resistance, alkali resistance, durability, and pollution-free properties to inorganic coatings, effectively resolving the problem of existing inorganic coatings struggling to simultaneously address multiple performance issues. The film-forming aid AH-16 has the advantages of good softening effect and good film-forming properties for latex particles, which can greatly enhance the density and wear resistance of the coating, making it difficult for stains to adhere, and can resist repeated washing and wear. The reasonable combination of additives such as thickeners, anti-settling agents, and dispersants can ensure the stability of inorganic coatings during storage and construction, prevent the precipitation or stratification of components such as pigments and fillers, and make the coating evenly distributed, further improving the overall performance. In summary, the coating composition provided by the present application can prepare high-performance silica sol inorganic coatings with excellent properties such as Class A combustion performance, air permeability, water resistance, scrub resistance, stain resistance, resistance to artificial aging, and environmental protection, meeting the market's expectations for zero VOC and high-performance architectural coatings, and has broad application prospects in the field of architectural coatings.

[0010] Optionally, the coating composition includes the following components in parts by weight: 170-190 parts of organosilicon-modified silica sol AH-G3, 60-70 parts of styrene-acrylic emulsion, 3.5-4.5 parts of film-forming aid AH-16, 4-6 parts of thickener, 0.8-1.2 parts of anti-settling agent, 4-6 parts of dispersant, 390-450 parts of pigment and filler, 2-3 parts of modified cellulose and 270-310 parts of water.

[0011] In some embodiments, the weight proportion of the organosilicon-modified silica sol AH-G3 may be 150-170 parts, 150-180 parts, 150-190 parts, 170-180 parts, 170-190 parts, 170-200 parts, 180-190 parts, 180-200 parts or 190-200 parts.

[0012] In a specific embodiment, the weight proportion of the organosilicon-modified silica sol AH-G3 may also be 150 parts, 170 parts, 180 parts, 190 parts or 200 parts.

[0013] In some embodiments, the weight parts of the film-forming aid AH-16 can be 3-3.5 parts, 3-4 parts, 3-4.5 parts, 3.5-4 parts, 3.5-4.5 parts, 3.5-5 parts, 4-4.5 parts, 4-5 parts or 4.5-5 parts.

[0014] In a specific embodiment, the weight portion of the film-forming aid AH-16 can also be 3 parts, 3.5 parts, 4 parts, 4.5 parts or 5 parts.

[0015] Optionally, the coating composition includes the following components in parts by weight: 180 parts of organosilicon-modified silica sol AH-G3, 65 parts of styrene-acrylic emulsion, 4 parts of film-forming aid AH-16, 5 parts of thickener, 1 part of anti-settling agent, 5 parts of dispersant, 425 parts of pigments and fillers, 2.5 parts of modified cellulose and 285 parts of water.

[0016] Optionally, based on the weight of the coating composition, the pigments and fillers include the following components in parts by weight: 140-160 parts of titanium dioxide, 40-60 parts of kaolin, 65-80 parts of wollastonite powder, and 140-160 parts of heavy calcium powder.

[0017] Optionally, the model of the thickener is PT-669, and the model of the anti-settling agent is ALLPON ® P307, dispersant model is ALLPON ® 860, the model of modified cellulose is P36000S.

[0018] Optionally, the coating composition further comprises 1.5-2.5 parts of a preservative, 8-16 parts of a dry film mildew preventer, 0.3-0.7 parts of a wetting agent, and 0.4-0.6 parts of a defoaming agent.

[0019] In the present application, in order to improve the adhesion of the inorganic coating and reduce splashing during construction, an appropriate amount of adhesive may be added to the coating composition; in order to enhance the weather resistance of the coating in special environments, an appropriate amount of ultraviolet absorber may also be added.

[0020] In a second aspect, the present application provides a high-performance silica sol inorganic coating, which is prepared using the aforementioned coating composition.

[0021] In a third aspect, the present application provides a method for preparing a high-performance silica sol inorganic coating, comprising the following steps:

[0022] (1) First, add preservatives, dry film mildew inhibitors, anti-settling agents, wetting agents, defoaming agents, pigments and fillers, and film-forming aids to part of the water and stir at 500-1000 rpm for 10-20 minutes;

[0023] (2) Then add the dispersant and stir at 1500-2000 rpm for 30-45 minutes. During the stirring process, add the modified cellulose; the modified cellulose is dispersed with the remaining water and then gradually added to the system;

[0024] (3) Finally, add styrene-acrylic emulsion, silicone-modified silica sol AH-G3 and thickener, adjust the speed to 600-800 rpm, and continue stirring for 10-15 minutes to obtain high-performance silica sol inorganic coating.

[0025] In summary, this application has the following beneficial effects:

[0026] 1. This application uses organosilicon-modified silica sol AH-G3, styrene-acrylic emulsion, film-forming aid AH-16, etc. as the main raw materials for high-performance silica sol inorganic coatings, thereby preparing a high-performance silica sol inorganic coating with excellent comprehensive properties such as Class A combustion performance, air permeability, water resistance, scrub resistance, stain resistance, resistance to artificial aging, environmental protection and storage properties. This solves the problem of existing architectural coatings that cannot simultaneously take into account multiple properties and has a good application prospect.

[0027] 2. This application further controls the weight of the organosilicon-modified silica sol AH-G3 within the range of 170-190 parts, and the weight of the film-forming aid AH-16 within the range of 3.5-4.5 parts. The resulting silica sol inorganic coating has better air permeability, can help the wall drain excess moisture inside, prevent the wall from mold, deterioration, bulging and falling off due to long-term moisture, and protect the wall surface health. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a physical photo of the high-performance silica sol inorganic coating obtained in Example 3 of the present application.

[0029] Figure 2 This is a physical photo of the high-performance silica sol inorganic coating obtained in Comparative Example 1 of the present application. DETAILED DESCRIPTION

[0030] The present application provides a coating composition, comprising the following components in parts by weight: 150-200 parts of organosilicon-modified silica sol AH-G3, 60-70 parts of styrene-acrylic emulsion, 3-5 parts of film-forming aid AH-16, 4-6 parts of thickener, 0.8-1.2 parts of anti-settling agent, 4-6 parts of dispersant, 140-160 parts of titanium dioxide, 40-60 parts of kaolin, 65-80 parts of wollastonite powder, 140-160 parts of heavy calcium powder, 1.5-2.5 parts of preservative, 8-16 parts of dry film mildew inhibitor, 0.3-0.7 parts of wetting agent, 0.4-0.6 parts of defoaming agent, 2-3 parts of modified cellulose and 270-310 parts of water; further, the coating composition comprises the following components in parts by weight: organosilicon-modified silica sol AH-G3 170-190 parts, styrene-acrylic emulsion 60-70 parts, film-forming aid AH-16 3.5-4.5 parts, thickener 4-6 parts, anti-settling agent 0.8-1.2 parts, dispersant 4-6 parts, titanium dioxide 140-160 parts, kaolin 40-60 parts, wollastonite powder 65-80 parts, heavy calcium powder 140-160 parts, preservative 1.5-2.5 parts, dry film mildew inhibitor 8-16 parts, wetting agent 0.3-0.7 part, defoamer 0.4-0.6 part, modified cellulose 2-3 parts and water 270-310 parts.

[0031] The present application also provides a high-performance silica sol inorganic coating prepared using the above coating composition, the preparation method of which comprises the following steps:

[0032] (1) First, add preservatives, dry film mildew inhibitors, anti-settling agents, wetting agents, defoaming agents, pigments and fillers, and film-forming aids to part of the water and stir at 500-1000 rpm for 10-20 minutes;

[0033] (2) Then add the dispersant and stir at 1500-2000 rpm for 30-45 minutes. During the stirring process, add the modified cellulose; the modified cellulose is dispersed with the remaining water and then gradually added to the system;

[0034] (3) Finally, add styrene acrylic emulsion, silicone modified silica sol AH-G3 and thickener, adjust the speed to 600-800 rpm, and continue stirring for 10-15 minutes to obtain high-performance silica sol inorganic coating.

[0035] The sources of the raw materials used in the examples of this application are shown in Table 1 below:

[0036] Table 1 Sources of raw materials used in the examples of this application

[0037]

[0038] The organosilicon-modified silica sol AH-G3 used in this application has a VOC content of <2.0 g / L, a SiO2 content of 25±1%, a sodium oxide content of <0.3%, a pH of 9.5-11.0, a density of 1.10-1.20 g / ml at 25°C, a viscosity of <6.5 mPa·s at 25°C, and a particle size of 15-28 nm. The film-forming aid AH-16 used in this application is diisobutyl adipate (CAS: 141-04-8) with a purity of ≥99.5%. All raw materials, reagents, and solvents used in this application can be homemade or commercially available.

[0039] The present application is further described in detail below with reference to the embodiments, performance testing and accompanying drawings.

[0040] Examples 1-9

[0041] Examples 1-9 each provide a high-performance silica sol inorganic coating.

[0042] The difference between the above embodiments is that the addition amounts of the organosilicon-modified silica sol AH-G3 and the film-forming aid AH-16 in the high-performance silica sol inorganic coating are shown in Table 2 below.

[0043] The preparation method of the high-performance silica sol inorganic coating provided in Examples 1-9 comprises the following steps:

[0044] (1) First, add 2g of preservative SC-189, dry film mildew inhibitor M3, and anti-settling agent ALLPON to 250g of water. ® P3071g, wetting agent ALLPON ® 100 0.5g, defoaming agent ALLPON ® 235, 150g of rutile titanium dioxide R818, 50g of kaolin, 75g of wollastonite powder, 150g of heavy calcium powder and 4g of film-forming aid AH-16, stirred at 600rpm for 10min;

[0045] (2) Then add dispersant ALLPON ® 860 5g, stirred at 1800 rpm for 30 min, and the aqueous dispersion of modified cellulose P36000S was gradually added during the stirring process (2.5g of modified cellulose P36000S was dispersed in 35g of water);

[0046] (3) Finally, 65 g of styrene-acrylic emulsion 5969, silicone-modified silica sol AH-G3 and 5 g of acrylic associative thickener PT-669 were added, and the speed was adjusted to 700 rpm. Stirring was continued for 10 min to obtain a high-performance silica sol inorganic coating.

[0047] Table 2 Addition amount of organosilicon-modified silica sol AH-G3, dry film mildew inhibitor and defoamer in Examples 1-9

[0048] Comparative Example 1

[0049] Comparative Example 1 provides a silica sol inorganic coating.

[0050] The difference between the above comparative example and Example 3 is that the organosilicon-modified silica sol AH-G3 is replaced by silica sol commonly used on the market (SiO2 content of 25±1%, sodium oxide content <0.3%, pH value of 8.5-10.0, density at 25°C of 1.10-1.20 g / ml, viscosity at 25°C of <6.5 mPa.s, and particle size of 8-12 nm). Comparative Example 2

[0051] Comparative Example 2 provides a silica sol inorganic coating.

[0052] The difference between the comparative example and Example 3 is that the organosilicon-modified silica sol AH-G3 is replaced by methyltrimethoxysilane-modified silica sol;

[0053] The preparation method of the above-mentioned methyltrimethoxysilane-modified silica sol is as follows: the pH value of the silica sol is adjusted to 3-6 with acid, and then methyltrimethoxysilane is added while stirring in a water bath at 60°C, wherein the mass ratio of the added amount of methyltrimethoxysilane to the SiO2 in the silica sol is 3:1; the reaction is stirred for 3 hours, and the by-products generated by hydrolysis are evaporated to obtain methyltrimethoxysilane-modified silica sol. Comparative Example 3

[0054] Comparative Example 3 provides a silica sol inorganic coating.

[0055] The difference between the comparative example and Example 3 is that the organosilicon-modified silica sol AH-G3 is replaced by polycarbonate-modified silica sol.

[0056] The preparation method of the polycarbonate-modified silica sol used in Comparative Example 3 comprises the following steps: weighing 100 g of silica sol, dropwise adding a pH adjuster to adjust the pH to 9-10, adding 1 g of a silane coupling agent KH-550, stirring for reaction, and after the reaction is completed, adding 150 g of an aqueous polycarbonate, and stirring at high speed to obtain a polycarbonate-modified silica sol emulsion. Comparative Example 4

[0057] Comparative Example 4 provides a silica sol inorganic coating.

[0058] The difference between the comparative example and Example 3 is that the film-forming aid AH-16 is replaced by alcohol ester dodecahydrate (CAS No. 25265-77-4). Comparative Example 5

[0059] Comparative Example 5 provides a silica sol inorganic coating.

[0060] The difference between the comparative example and Example 3 is that the film-forming aid AH-16 is replaced by OE300 (Eastman).

[0061] Performance testing

[0062] Various performance tests were performed on the silica sol inorganic coatings obtained in Examples 1-9 and Comparative Examples 1-5. The results are shown in Table 3 below.

[0063] The testing methods for various properties are as follows: the testing method for thermal storage stability is JG / T 26-2002 5.7; the testing method for water vapor transmission rate is JG / T 309-2011; the testing method for water resistance (168h) is GB / T 26-2002 5.10; the testing method for scrubber resistance is GB / T 9266-2009; the testing method for artificial ageing resistance is GB / T 1865-2009; the testing method for VOC content is GB 1882-2020 6.2.1; and the testing methods for flammability are GB / T 20284-2006 and GB / T14402-2007.

[0064] Table 3 Test results of various properties of silica sol inorganic coatings obtained in Examples 1-9 and Comparative Examples 1-5

[0065]

[0066]

[0067] According to the test results in Table 3, the high-performance silica sol inorganic coatings obtained in Examples 1-9 have no irritating odor and their water vapor transmission rates are 927-982 g / m 2 d, after 168h water resistance test, there is no blistering, cracking, peeling, or powdering, and it can be washed without leaking after 10,000 times. After 800h artificial aging test, there is no blistering, cracking, or peeling, and the powdering and discoloration are 0 level. VOC is not detected. After 30d heat storage stability test, there is no caking, flocculation, or mildew. Among them, the high-performance silica sol inorganic coating obtained in Example 3 is as follows Figure 1 As shown, it has good fluidity and no agglomeration or flocculation. Therefore, this application demonstrates that the use of organosilicon-modified silica sol AH-G3, styrene-acrylic emulsion, and film-forming aid AH-16 as raw materials for a high-performance silica sol inorganic coating enables the preparation of a high-performance silica sol inorganic coating with excellent comprehensive properties, including air permeability, water resistance, scrub resistance, resistance to artificial aging, environmental friendliness, and storage stability.

[0068] Comparative Example 1 uses unmodified silica sol as the main raw material, and the silica sol inorganic coating prepared therefrom is as follows Figure 2 As shown, there is obvious agglomeration and flocculation.

[0069] Comparative Example 2-3 uses methyltrimethoxysilane-modified silica sol or polycarbonate-modified silica sol as the main raw material of the silica sol inorganic coating. The VOC content of the silica sol inorganic coating obtained is high, and the environmental protection of the coating is poor.

[0070] Comparative Example 4 uses alcohol ester dodecahydrate as a film-forming aid for the silica sol inorganic coating. The silica sol inorganic coating obtained has a pungent odor and leaks after being washed 5065 times.

[0071] Comparative Example 5 uses OE300 as a film-forming aid for the silica sol inorganic coating. The silica sol inorganic coating produced thereby has a pungent odor and leaks through the bottom after being washed 7593 times.

[0072] Although the present invention has been described in detail above using general descriptions and specific embodiments, it will be apparent to those skilled in the art that modifications and improvements may be made based on the present invention. Therefore, such modifications and improvements, which do not depart from the spirit of the present invention, are intended to be within the scope of protection claimed herein.

Claims

1. A coating composition, characterized in that The composition includes the following components in parts by weight: 170-190 parts of organosilicon modified silica sol AH-G31, 60-70 parts of styrene acrylic emulsion, 3.5-4.5 parts of film-forming aid AH-16, 4-6 parts of thickener PT-669, and anti-settling agent ALLPON ® P307 0.8-1.2 parts, dispersant ALLPON ® 860 4-6 parts, pigments and fillers 390-450 parts, modified cellulose P36000S 2-3 parts and water 270-310 parts; The organosilicon-modified silica sol AH-G3 has a VOC content of less than 2.0 g / L, a SiO2 content of 25±1%, a sodium oxide content of less than 0.3%, a viscosity at 25° C. of less than 6.5 mPa.s, a particle size of 15-28 nm, and a pH of 9.5-11.

0.

2. The coating composition according to claim 1, wherein The coating composition includes the following components in parts by weight: 180 parts of organosilicon-modified silica sol AH-G3, 65 parts of styrene-acrylic emulsion, 5 parts of thickener, 1 part of anti-settling agent, 5 parts of dispersant, 425 parts of pigments and fillers, 4 parts of film-forming aid AH-16, 2.5 parts of modified cellulose and 285 parts of water.

3. The coating composition according to claim 1, wherein Based on the weight of the coating composition, the pigments and fillers include the following components in parts by weight: 140-160 parts of titanium dioxide, 40-60 parts of kaolin, 65-80 parts of wollastonite powder, and 140-160 parts of heavy calcium powder.

4. The coating composition according to any one of claims 1 to 3, characterized in that The coating composition further comprises 1.5-2.5 parts of an antiseptic, 8-16 parts of a dry film mildew preventer, 0.3-0.7 parts of a wetting agent and 0.4-0.6 parts of a defoaming agent.

5. A high-performance silica sol inorganic coating, characterized in that: The coating is prepared using the coating composition according to any one of claims 1 to 4.

6. The method for preparing a high-performance silica sol inorganic coating according to claim 5, wherein: The following steps are involved: (1) First, add preservatives, dry film mildew inhibitors, anti-settling agents, wetting agents, defoaming agents, pigments and fillers, and film-forming aids to part of the water and stir at 500-1000 rpm for 10-20 minutes; (2) Then add the dispersant and stir at 1500-2000 rpm for 30-45 minutes. During the stirring process, add the modified cellulose; The modified cellulose is dispersed with the remaining water and then gradually added into the system; (3) Finally, add styrene-acrylic emulsion, silicone-modified silica sol AH-G3 and thickener, adjust the speed to 600-800 rpm, and continue stirring for 10-15 minutes to obtain high-performance silica sol inorganic coating.

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