A silicon-modified inorganic stone-like paint and its preparation method

Abstract

This invention relates to a silicon-modified inorganic stone-like paint and its preparation method. The silicon-modified inorganic stone-like paint is mainly prepared from the following components in parts by weight: 10-20 parts of cyclosiloxane monomer-modified styrene-acrylic emulsion, 1-10 parts of epoxy-modified silica, 0.02-1 parts of methacryloyloxy-modified silica, 0.02-0.5 parts of glyoxal-modified hydroxyethyl cellulose ether, 60-75 parts of colored sand, 0.02-0.5 parts of ammonia, 0.2-1 parts of film-forming aid, 0.2-1 parts of antifreeze, 0.02-0.5 parts of thickener, 0.02-0.5 parts of defoamer, 0.02-0.5 parts of bactericide, and 7.85-13.48 parts of water. The silicon-modified inorganic stone paint of the present invention has excellent initial water spraying resistance to whitening, storage stability, high spraying atomization efficiency, good anti-splashing properties and low sand shedding rate, and can be widely used in old house renovation and urban renewal.

Description

Technical Field

[0001] This application relates to the field of coating technology, and in particular to a silicon-modified inorganic stone-like paint and its preparation method. Background Technology

[0002] Inorganic stone-like paint is a thick-film exterior wall coating made primarily of inorganic silicates and acrylic emulsions as film-forming substances, high-quality colored sand as pigments and fillers, water as a dispersant, and supplemented with high-performance additives. It possesses excellent Class A non-combustible properties, meeting the application requirements for fire-resistant areas in GB 8624-2012 "Classification of Combustion Performance of Building Materials and Products" standard, providing efficient safety protection for buildings. Therefore, it is suitable for the decoration and protection of various building walls in old building renovation and urban renewal projects, such as civil buildings, rail transit, schools, public buildings, and industrial plants.

[0003] However, due to the introduction of inorganic silicates as an important film-forming substance, inorganic stone paint suffers from several problems: poor initial water resistance and whitening leading to aesthetic issues; poor spray atomization and anti-splatter performance resulting in high sand shedding rate during construction; and poor system compatibility leading to thickening after storage. These issues significantly limit the widespread application of inorganic stone paint in old building renovation and urban renewal. Summary of the Invention

[0004] In view of this, this application provides a silicon-modified inorganic stone paint and its preparation method. The inorganic stone paint of the present invention has excellent initial water spraying resistance to whitening, storage stability, high spraying atomization efficiency, good anti-splashing properties, and low sand shedding rate.

[0005] To achieve the above objectives, this application employs the following technical solution:

[0006] A silicon-modified inorganic stone-like paint is mainly prepared from the following raw materials in the following weight ratios:

[0007] 10-20 parts of cyclosiloxane monomer-modified styrene-acrylic emulsion.

[0008] 1-10 parts of epoxy-modified silica

[0009] 0.02-1 part of methacryloyloxy modified silica,

[0010] 0.02-0.5 parts of glyoxal-modified hydroxyethyl cellulose ether

[0011] 60-75 parts colored sand

[0012] 0.02-0.5 parts of 10wt% ammonia solution

[0013] Film-forming aid 0.2-1 part,

[0014] Antifreeze 0.2-1 part,

[0015] Thickener 0.02-0.5 parts,

[0016] Defoamer 0.02-0.5 parts,

[0017] 0.02-0.5 parts of bactericide,

[0018] Water 7.85-13.48 parts.

[0019] Specifically, the glass transition temperature of the cyclosiloxane monomer-modified styrene-acrylic emulsion is 25-30°C; the cyclosiloxane monomer-modified styrene-acrylic emulsion is prepared by modifying the styrene-acrylic emulsion with a cyclosiloxane monomer through chemical graft copolymerization; the cyclosiloxane monomer is octamethylcyclotetrasiloxane.

[0020] Specifically, the epoxy-modified silica has a particle size of 5-15 nm and is prepared by modifying the silica surface using 3-(2,3-epoxypropoxy)propyltriethoxysilane via chemical graft copolymerization.

[0021] Specifically, the particle size of the methacryloyloxy modified silica is 5-15 nm, and the methacryloyloxy modified silica is prepared by modifying the surface of silica using 3-(methacryloyloxy)propyltriisopropoxysilane via chemical graft copolymerization.

[0022] Specifically, the viscosity of a 1wt% aqueous solution of the glyoxal-modified hydroxyethyl cellulose ether is 3000-6000 mPa·s. The glyoxal-modified hydroxyethyl cellulose ether is prepared by acetalization of glyoxal with the hydroxyl groups on the hydroxyethyl cellulose ether molecular chain, thereby forming reversible cross-linking bonds between adjacent hydroxyethyl cellulose ether molecular chains or in different parts of the same molecular chain.

[0023] Specifically, the film-forming aid is dodecyl alcohol ester, the antifreeze is ethylene glycol, the thickener is a polyurethane thickener, the defoamer is a mineral oil, and the bactericide is a Kathon-based agent.

[0024] This invention also provides a method for preparing the above-mentioned silicon-modified inorganic stone-like paint, comprising the following steps:

[0025] (1) First add 74-95% water, and add bactericide, antifreeze, film-forming aid and glyoxal modified hydroxyethyl cellulose ether while stirring at 300-400 rpm. Disperse at 500-600 rpm for 3-5 minutes.

[0026] (2) Next, slowly add ammonia water over a period of 0.5-1 minute and disperse at a speed of 700-800 rpm for 3-5 minutes;

[0027] (3) Then, add epoxy-modified silica, methacryloxy-modified silica and cyclosiloxane monomer-modified styrene-acrylic emulsion, and disperse at 600-700 rpm for 3-5 minutes;

[0028] (4) Finally, add defoamer, thickener, remaining water and colored sand, and disperse at 700-800 rpm for 5-10 minutes.

[0029] The silicon-modified inorganic stone-like paint of this invention uses a compound of three film-forming materials: cyclosiloxane monomer-modified styrene-acrylic emulsion, epoxy-modified silica, and methacryloxy-modified silica. Individually, the modification of the styrene-acrylic emulsion by octamethylcyclotetrasiloxane monomer enhances the hydrophobicity of the emulsion, reducing the water-whitening problem in the initial stage of paint film application; the modification of silica by 3-(2,3-epoxypropoxy)propyltriethoxysilane improves the compatibility of silica in the system, reducing the thickening problem after paint storage; and the modification of silica by 3-(methacryloyloxy)propyltriisopropoxysilane improves the atomization efficiency and anti-splatter properties of the paint during spraying, reducing the problem of high sand shedding rate. However, the silicon-modified inorganic stone paint of the present invention uses a compound of three film-forming materials: cyclosiloxane monomer-modified styrene-acrylic emulsion, epoxy-modified silica, and methacryloyloxy-modified silica. There is also a "silicon-silicon" interaction between these three film-forming materials. This interaction synergistically endows the silicon-modified inorganic stone paint with excellent initial water spraying resistance, water whitening, spray atomization, anti-splattering, and system compatibility. Specifically, the modification of styrene-acrylic emulsion by octamethylcyclotetrasiloxane monomer significantly reduces problems such as water whitening and splashing in the initial stage of paint film application, while also reducing the sand shedding rate during paint application; 3-(2,3-epoxypropoxy)propyltriethoxysilane for silica not only reduces the thickening problem of paint after storage, but also improves the atomization efficiency of paint spraying; 3-(methacryloyloxy)propyltriisopropoxysilane for silica not only improves the atomization efficiency and anti-splatter properties of paint during spraying and application, reducing the problem of high sand shedding rate, but also improves the post-thickening problem of paint.

[0030] As can be seen from the above technical solution, this application has at least the following advantages and positive effects:

[0031] In this invention, three film-forming materials are combined: cyclosiloxane monomer-modified styrene-acrylic emulsion, epoxy-modified silica, and methacryloxy-modified silica. These three film-forming materials have a "silicon-silicon" interaction, which synergistically endows the silicon-modified inorganic stone paint with excellent initial water spraying resistance, whitening resistance, and compatibility. It also has good paint storage stability, high spraying atomization efficiency, good anti-splatter properties, and low sand shedding rate. Detailed Implementation

[0032] The terminology used in the implementation section of this application is for the purpose of explaining specific embodiments of this application only, and is not intended to limit this application.

[0033] Example 1

[0034] A silicon-modified inorganic stone-like paint, the weight parts of each raw material and the preparation method are as follows:

[0035] (1) First add 7 parts water, and then add 0.2 parts Kathon bactericide, 0.5 parts ethylene glycol antifreeze, 0.5 parts dodecyl ester film-forming aid and 0.2 parts glyoxal modified hydroxyethyl cellulose ether in sequence while stirring at 350 rpm. Then disperse at 550 rpm for 4 minutes.

[0036] (2) Next, slowly add 0.05 parts of 10wt% ammonia water over a period of 0.75 minutes and disperse at 750 rpm for 4 minutes;

[0037] (3) Then, add 5 parts of epoxy-modified silica with a particle size of 10 nm, 0.5 parts of methacryloyloxy-modified silica with a particle size of 10 nm and 10 parts of cyclosiloxane monomer-modified styrene-acrylic emulsion with a glass transition temperature of 28 °C in sequence, and disperse at 650 rpm for 4 minutes.

[0038] (4) Finally, add 0.1 parts of mineral oil defoamer, 0.1 parts of polyurethane thickener, the remaining 0.85 parts of water and 75 parts of colored sand in sequence, and disperse at 750 rpm for 8 minutes.

[0039] Example 2

[0040] A silicon-modified inorganic stone-like paint, the weight parts of each raw material and the preparation method are as follows:

[0041] (1) First add 10 parts of water, and then add 0.02 parts of Kathon bactericide, 0.2 parts of ethylene glycol antifreeze, 0.2 parts of dodecyl ester film-forming aid and 0.02 parts of glyoxal modified hydroxyethyl cellulose ether in sequence while stirring at 300 rpm. Then disperse at 500 rpm for 3 minutes.

[0042] (2) Next, slowly add 0.02 parts of 10wt% ammonia water over 0.5 minutes and disperse at 700 rpm for 3 minutes;

[0043] (3) Then, add 1 part of epoxy-modified silica with a particle size of 5 nm, 0.02 parts of methacryloyloxy-modified silica with a particle size of 5 nm and 20 parts of cyclosiloxane monomer-modified styrene-acrylic emulsion with a glass transition temperature of 25 °C in sequence, and disperse at 600 rpm for 3 minutes.

[0044] (4) Finally, add 0.02 parts of mineral oil defoamer, 0.02 parts of polyurethane thickener, the remaining 3.48 parts of water and 65 parts of colored sand in sequence, and disperse at 700 rpm for 5 minutes.

[0045] Example 3

[0046] A silicon-modified inorganic stone-like paint, the weight parts of each raw material and the preparation method are as follows:

[0047] (1) First add 9 parts water, and then add 0.5 parts Kathon bactericide, 1 part ethylene glycol antifreeze, 1 part dodecyl ester film-forming aid and 0.5 parts glyoxal modified hydroxyethyl cellulose ether in sequence while stirring at 400 rpm. Then disperse at 600 rpm for 5 minutes.

[0048] (2) Next, slowly add 0.5 parts of 10wt% ammonia water over 1 minute and disperse at 800 rpm for 5 minutes;

[0049] (3) Then, add 10 parts of epoxy-modified silica with a particle size of 15 nm, 1 part of methacryloyloxy-modified silica with a particle size of 15 nm and 15 parts of cyclosiloxane monomer-modified styrene-acrylic emulsion with a glass transition temperature of 30 °C in sequence, and disperse at 700 rpm for 5 minutes.

[0050] (4) Finally, add 0.5 parts mineral oil defoamer, 0.5 parts polyurethane thickener, the remaining 0.5 parts water and 60 parts colored sand in sequence, and disperse at 800 rpm for 10 minutes.

[0051] In the above embodiments:

[0052] The cyclosiloxane monomer-modified styrene-acrylic emulsion is prepared by modifying the styrene-acrylic emulsion with cyclosiloxane monomers through chemical graft copolymerization.

[0053] The cyclosiloxane monomer is octamethylcyclotetrasiloxane; the epoxy-modified silica is prepared by modifying the surface of silica with 3-(2,3-epoxypropoxy)propyltriethoxysilane via chemical graft copolymerization.

[0054] The methacryloyloxy modified silica is prepared by modifying the surface of silica with 3-(methacryloyloxy)propyltriisopropoxysilane via chemical graft copolymerization.

[0055] The viscosity of a 1 wt% aqueous solution of the glyoxal-modified hydroxyethyl cellulose ether is 3000-6000 mPa·s. The glyoxal-modified hydroxyethyl cellulose ether is prepared by acetalization of glyoxal with the hydroxyl groups on the hydroxyethyl cellulose ether molecular chain, thereby forming reversible cross-linking bonds between adjacent hydroxyethyl cellulose ether molecular chains or different parts of the same molecular chain.

[0056] Comparative Example 1

[0057] Comparative Example 1 is the same as Example 1, except that the cyclosiloxane monomer-modified styrene-acrylic emulsion in Example 1 is replaced with an equal amount of commercially available ordinary styrene-acrylic emulsion.

[0058] Comparative Example 2

[0059] Comparative Example 2 is the same as Example 1, except that the epoxy-modified silica in Example 1 is replaced with an equal amount of commercially available ordinary silica.

[0060] Comparative Example 3

[0061] Comparative Example 3 is the same as Example 1, except that the methacryloxy-modified silica in Example 1 is replaced with an equal amount of commercially available ordinary silica.

[0062] The above Examples 1-3 and Comparative Examples 1-3 were subjected to various performance tests according to the following test methods:

[0063] Initial water spraying resistance to whitening, spray atomization efficiency and anti-splatter properties: The silicon-modified inorganic stone paint of this invention was compared with commercially available inorganic stone paint. The test results were scored from 1 to 10, with higher scores indicating better performance.

[0064] Sand shedding rate: It is calculated according to the formula "Sand shedding rate = 1 - mass of paint sprayed on the wall / total mass of paint consumed". The higher the value, the higher the sand shedding rate.

[0065] Thickening after storage: The difference in viscosity of the paint before and after storage in a 50℃ oven for 7 days is tested. The higher the value, the more severe the thickening after storage.

[0066] The performance data obtained according to the above testing methods are shown in Table 1.

[0067] Table 1

[0068]

[0069] According to Comparative Example 1 in the table, after replacing the cyclosiloxane monomer-modified styrene-acrylic emulsion in the silicone-modified inorganic stone paint with commercially available ordinary styrene-acrylic emulsion, the initial water-whitening resistance and anti-splatter properties were severely affected, and the sand shedding rate was affected to some extent. According to Comparative Example 2, after replacing the epoxy-modified silica in the silicone-modified inorganic stone paint with commercially available ordinary silica, the spray atomization efficiency and thickening after storage were severely affected, and the sand shedding rate was affected to some extent. According to Comparative Example 3, after replacing the methacryloxy-modified silica in the silicone-modified inorganic stone paint with commercially available ordinary silica, the spray atomization efficiency, anti-splatter properties, and sand shedding rate were severely affected, and the thickening after storage was affected to some extent. This demonstrates that the introduction of three film-forming agents—cyclosiloxane monomer-modified styrene-acrylic emulsion, epoxy-modified silica, and methacryloyloxy-modified silica—in the silicon-modified inorganic stone paint of this invention significantly improves the performance of the stone paint, and there is a synergistic effect among these three film-forming agents.

[0070] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the embodiments of this application, and are not intended to limit them; although the embodiments of this application have been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A silicon-modified inorganic stone-like paint, characterized in that: It is mainly prepared from the following raw materials in the following weight ratios: 10-20 parts of cyclosiloxane monomer-modified styrene-acrylic emulsion. 1-10 parts of epoxy-modified silica 0.02-1 part of methacryloyloxy modified silica, 0.02-0.5 parts of glyoxal-modified hydroxyethyl cellulose ether 60-75 parts colored sand 0.02-0.5 parts of 10wt% ammonia solution Film-forming aid 0.2-1 part, Antifreeze 0.2-1 part, Thickener 0.02-0.5 parts, Defoamer 0.02-0.5 parts, 0.02-0.5 parts of bactericide, Water 7.85-13.48 parts.

2. The silicon-modified inorganic stone-like paint according to claim 1, characterized in that: The glass transition temperature of the cyclosiloxane monomer-modified styrene-acrylic emulsion is 25-30℃; the cyclosiloxane monomer-modified styrene-acrylic emulsion is prepared by modifying the styrene-acrylic emulsion with cyclosiloxane monomer through chemical graft copolymerization. The cyclosiloxane monomer is octamethylcyclotetrasiloxane.

3. The silicon-modified inorganic stone-like paint according to claim 1, characterized in that: The epoxy-modified silica has a particle size of 5-15 nm and is prepared by modifying the surface of silica with 3-(2,3-epoxypropoxy)propyltriethoxysilane via chemical graft copolymerization.

4. The silicon-modified inorganic stone-like paint according to claim 1, characterized in that: The particle size of the methacryloyloxy modified silica is 5-15 nm. The methacryloyloxy modified silica is prepared by modifying the surface of silica using 3-(methacryloyloxy)propyltriisopropoxysilane via chemical graft copolymerization.

5. The silicon-modified inorganic stone-like paint according to claim 1, characterized in that: The viscosity of a 1 wt% aqueous solution of the glyoxal-modified hydroxyethyl cellulose ether is 3000-6000 mPa·s. The glyoxal-modified hydroxyethyl cellulose ether is prepared by acetalization of glyoxal with the hydroxyl groups on the hydroxyethyl cellulose ether molecular chain, thereby forming reversible cross-linking bonds between adjacent hydroxyethyl cellulose ether molecular chains or different parts of the same molecular chain.

6. The silicon-modified inorganic stone-like paint according to claim 1, characterized in that: The film-forming aid is dodecyl alcohol ester, the antifreeze is ethylene glycol, the thickener is a polyurethane thickener, the defoamer is a mineral oil, and the bactericide is a Kathon-based agent.

7. The method for preparing silicon-modified inorganic stone-like paint according to any one of claims 1-6, characterized in that: Includes the following steps: (1) First add water accounting for 74-95% of its total volume, and add bactericide, antifreeze, film-forming aid and glyoxal modified hydroxyethyl cellulose ether under stirring at 300-400 rpm. Then disperse at 500-600 rpm for 3-5 minutes. (2) Next, slowly add ammonia water over a period of 0.5-1 minute and disperse at a speed of 700-800 rpm for 3-5 minutes; (3) Then, add epoxy-modified silica, methacryloxy-modified silica and cyclosiloxane monomer-modified styrene-acrylic emulsion, and disperse at 600-700 rpm for 3-5 minutes; (4) Finally, add defoamer, thickener, remaining water and all colored sand, and disperse at 700-800 rpm for 5-10 minutes.

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