A hydrophobic modified rock chip, a stone-like coating and its preparation method

Abstract

This invention discloses a hydrophobically modified rock flake, a stone-like coating, and its preparation method, belonging to the technical field of stone-like coatings. The hydrophobically modified rock flake is obtained by hydrophobically grafting potassium methylsilicate onto the surface of the decorative rock flake. This invention also includes a stone-like coating prepared using the hydrophobically modified rock flake described herein. Because the hydrophobically modified rock flake tends to gravitate towards the paint film surface, the repulsive interaction between it and the liquid molecules of the coating creates a slip effect, making the decorative colors of the stone-like coating vivid and prominent. The main color rock flake and color paste are used in combination to provide sufficient hiding power to the paint film and can effectively encapsulate the white sand, preventing white sand from appearing on the paint film. This solves the contradictory problems of reduced clarity of the rock flake in the paint film and decreased stone-like realism when the amount of pigment added is large, and white sand appearing on the paint film when the amount of pigment added is small.

Description

Technical Field

[0001] This invention relates to the field of stone-like coating technology, and in particular to a hydrophobic modified rock chip, a stone-like coating, and a method for preparing the same. Background Technology

[0002] In the building exterior wall market, in terms of stone imitation and texture strength, the main options are water-based sand-colored paint and real stone paint, both offering advantages such as high cost-effectiveness, environmental friendliness, and excellent stone imitation effects. Real stone paint is formulated with various colors of natural colored sand. Natural colored sand has good mechanical stability, allowing for production using large-tonnage mixing tanks and rapid, efficient spraying under high pressure. Furthermore, it avoids color bleeding between colored sand particles during production and application, providing color control. However, the mining and purchasing of natural colored sand presents significant challenges, meaning real stone paint will gradually be phased out of the market. Another widely used stone imitation coating, commonly known as water-based sand-colored paint, is made by reacting cellulose ethers with protective colloids and other additives to encapsulate a small amount of white sand, creating a gel-like, water-based, multicolored dotted material that is uniformly suspended in a continuous phase. Water-based sand-colored paint dots are saturated with water, resulting in better fusion during drying and excellent stone imitation properties, making it one of the superior alternatives to real stone paint. However, the mechanical stability of the colored dots in water-based sand-textured multicolor coatings is far inferior to that of natural colored sand, making it difficult to achieve large-tonnage mixing tank production and rapid, efficient spraying under high pressure. Furthermore, the colored dots in water-based sand-textured multicolor coatings are easily broken, leading to color mixing and affecting the main hue of the stone-like paint, creating a problem of uncontrollable color matching during large-tonnage mixing tank production.

[0003] Existing stone-like products containing white sand, pigments, and rock chips are a beneficial supplement to the exterior wall coating market. However, the main color of these stone-like products is provided by rock chips and pigments, and the white sand needs to be coated with a certain amount of pigment to prevent it from appearing as white sand. However, as the amount of pigment added increases, the clarity of the rock chips in the paint film decreases, and the realism of the stone imitation decreases. Summary of the Invention

[0004] The present invention proposes a hydrophobically modified rock flake, a stone-like coating and its preparation method, which solves the contradictory problems of reduced clarity of the rock flake in the paint film and decreased stone-like realism when the amount of pigment added is large, and white sand jumping in the paint film when the amount of pigment added is small.

[0005] To achieve this objective, the present invention adopts the following technical solution:

[0006] A hydrophobically modified rock sheet, wherein the hydrophobically modified rock sheet is a composite rock sheet modified by surface grafting with potassium methylsilicate.

[0007] The preferred technical solution of the present invention is that the main components of the composite rock sheet are 30-50% acrylic resin and 40-50% heavy calcium carbonate powder; the thickness of the artificial composite rock sheet is between 0.05mm and 0.10mm.

[0008] The present invention also provides a method for preparing the above-mentioned hydrophobic modified rock slices as follows: Step A1: Soak the rock slices in an aqueous solution of potassium methylsilicate, wherein the mass concentration of potassium methylsilicate is 0.5%-10%, and the soaking time is 0.5-2h; Step A2: Dry the rock slices soaked in Step A1 at a temperature of 10℃-50℃ in an environment containing carbon dioxide gas for 0.5h-20h; Step A3: Continue to dry the rock slices obtained in Step A2 at a temperature of 50℃-105℃ in a gas-filled environment for 0.5h-24h to obtain hydrophobic modified rock slices.

[0009] A stone-like coating comprises a main color composition and an accent color composition, wherein the accent color composition comprises the hydrophobic modified rock flakes as described in any one of claims 1-3.

[0010] A preferred embodiment of the present invention comprises, by weight parts: 10-28 parts water; 0.1-10 parts color paste; 0.5-3 parts diatomaceous earth; 0.1-0.3 parts cellulose ether; 2-12 parts main color rock chips; 45-76 parts white sand; and the accent color composition comprises, by weight parts: 10-20 parts water; 70-80 parts hydrophobically modified rock chips, wherein the hydrophobically modified rock chips are any of the aforementioned hydrophobically modified rock chips; and 3-10 parts wetting agent.

[0011] A preferred embodiment of the present invention is that the main color composition further comprises: 0.05-1 part wetting agent; 0.05-0.15 part defoamer; 0.05-0.15 part neutralizer; 0.1-0.3 part thickener; 11-16 parts emulsion; 0.6-1.1 part film-forming aid; and 0.1-0.2 part preservative.

[0012] The preferred technical solution of the present invention is that the mass ratio of the main color composition to the accent color composition is 100:0.5-3, the SiO2 content in the diatomaceous earth is ≥90%, and the median particle size D50 is 10-14μm.

[0013] The preferred technical solution of the present invention is that the color paste is one or more of titanium dioxide paste, iron oxide red paste, iron oxide yellow paste, carbon black paste, phthalocyanine blue paste, and phthalocyanine green; the main color rock slice is an artificial composite rock slice with a mesh size of 30-40 mesh; the hydrophobic modified rock slice has a mesh size of 9-12 mesh; and the white sand is natural mineral sand with a mixed gradation between 20-200 mesh.

[0014] A preferred embodiment of the present invention is that the cellulose ether is hydroxyethyl cellulose ether; the wetting agent is alkyl polyoxyethylene ether; the defoamer is a mineral oil defoamer; the neutralizing agent includes any one or a combination of at least two of ammonia, 2-amino-2-methyl-1-propanol, diethanolamine, and triethanolamine; the thickener includes any one or a combination of at least two of alkali-swellable thickeners and polyurethane thickeners; the film-forming aid is dodecyl alcohol ester; and the preservative includes any one or a combination of at least two of 2-methyl-4-isothiazolin-3-one, 1,2-benzisothiazolin-3-one, and 2-methyl-5-chloro-4-isothiazolin-3-one.

[0015] The present invention also includes a method for preparing the above-mentioned stone-like coating. Step B1: Under stirring at a speed of 100-150 r / min, water and wetting agent are added sequentially, and then hydrophobic modified rock chips are added. The mixture is soaked for 0.5 h-24 h to obtain the accent color composition. Step B2: Under stirring at a speed of 500-750 r / min, water, cellulose ether, diatomaceous earth, wetting agent, defoamer, neutralizer, emulsion, film-forming aid, thickener, preservative and white sand are added sequentially. Then, the main color rock chips and color paste are added in proportion and stirred evenly to obtain the main color composition. Step B3: The speed is adjusted to 200-400 r / min, and the accent color composition of B1 is added to the main color composition in B2 after mixing and color matching. The mixture is stirred for 5-15 min to obtain the stone-like coating based on hydrophobic modified rock chips.

[0016] The beneficial effects of this invention are as follows:

[0017] (1) The hydrophobic modified rock flakes provided by the present invention are treated with potassium methylsilicate to give the surface of the rock flakes a hydrophobic effect; the use of the rock flakes in the preparation of imitation stone coatings enhances the water resistance of the coating film.

[0018] (2) This invention also provides a method for preparing a stone-like coating using the hydrophobic modified rock flakes. During the drying process of the paint film, the repulsive interaction between the hydrophobic portion of the surface of the hydrophobic modified rock flakes and the liquid molecules of the paint film creates a slip effect, causing the hydrophobic modified rock flakes to tend towards the surface of the paint film, resulting in a bright and prominent accent color.

[0019] (3) This invention utilizes hydrophobically modified rock flakes and main color rock flakes, along with the color paste, to solve the problems of reduced clarity and stone imitation realism when the amount of pigment added is large; and white sand is better wrapped in the middle of the paint film when the amount of pigment added is small, so that the paint film does not jump white sand. The stone imitation coating based on hydrophobically modified rock flakes is less prone to color bleeding. This invention also solves the contradictions in the preparation process of traditional stone imitation coatings: when the amount of pigment added is large, the clarity of rock flakes in the paint film is reduced, and the stone imitation realism is reduced; when the amount of pigment added is small, white sand jumps in the paint film. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this application can be arbitrarily combined with each other.

[0021] The technical solution of the present invention will be further illustrated below through specific embodiments.

[0022] Example 1

[0023] The present invention provides a hydrophobic modified rock sheet, which is an artificial composite rock sheet with a surface graft modification of potassium methylsilicate. The main components of the artificial composite rock sheet are 40% acrylic resin and 45% heavy calcium carbonate powder; the thickness of both is 0.06 mm.

[0024] Potassium methylsilicate surface-grafted modifiers are materials modified by introducing methyl groups onto the surface of potassium silicate. This modification can be achieved through various chemical methods, including the introduction of methyl groups via surface reactions on potassium silicate. The resulting potassium methylsilicate surface-grafted modifiers exhibit the following characteristics: firstly, improved hydrophobicity, as the introduction of hydrophobic methyl groups onto the potassium silicate surface enhances the material's surface hydrophobicity; secondly, improved adhesion, making it easier to bond with other materials or coatings; and thirdly, improved resistance to chemical corrosion.

[0025] Example 2

[0026] This embodiment provides a method for preparing hydrophobically modified rock slices as described in Example 1.

[0027] Step A1: Soak the rock slices in an aqueous solution of potassium methylsilicate with a mass concentration of 0.5%-10% (preferably 5%) for 0.5-2 hours (preferably 1 hour);

[0028] Step A2: Transfer the soaked rock slices from Step A1 into a fluidized bed drying device. The temperature of the device is controlled at 10℃-40℃ (preferably 40℃). A gas containing carbon dioxide (pure carbon dioxide or a gas containing carbon dioxide) is continuously introduced into the device to keep the rock slices in a fluidized state for 0.5h-20h (preferably 6h).

[0029] Step A3: Then, under the condition of temperature control of 50℃-105℃ (preferably 80℃) in the fluidized bed drying equipment, gas (the gas can be air or any other gas) is continuously introduced into the equipment for drying time of 0.5h-24h (preferably 10h) to obtain hydrophobic modified rock slices.

[0030] Example 3

[0031] A stone-like coating based on the hydrophobic modified rock flakes provided in Example 1, the following percentages are by mass.

[0032] Stone-like coatings include a main color composition and an accent color composition, wherein the mass ratio of the main color composition to the accent color composition is 100:(0.5-3).

[0033] The primary color composition comprises, by weight parts:

[0034] The ingredients are: 10-28 parts water, 0.1-10 parts color paste, 2 parts diatomaceous earth, 0.1-0.3 parts cellulose ether, 2-12 parts main color rock flakes, 1 part wetting agent, 0.1 part defoamer, 0.1 part neutralizer, 0.2 parts thickener, 13 parts emulsion, 0.9 parts film-forming aid, 0.1 part preservative, and 45-76 parts white sand.

[0035] Among them, the main color rock slices are artificial composite rock slices with a mesh size of 40 mesh; the SiO2 content in the diatomite is ≥90%, and the median particle size D50 is 12μm; the color pastes are titanium dioxide paste, iron red paste, iron yellow paste and carbon black paste, and the mixing ratio of the color pastes is 1:3:10:1; the white sand is a natural mineral sand, with a mesh size distribution ratio of 20% for 30 mesh, 40% for 80 mesh, and 40% for 100 mesh, and the variety is snowflake white.

[0036] The accent color composition comprises, by weight parts:

[0037] 10-20 parts water, 70-80 parts hydrophobic modified rock chips, and 3-10 parts wetting agent.

[0038] Among them, the mesh size of the hydrophobic modified rock slices is 9 mesh.

[0039] The specific types of raw materials used in the above materials are as follows:

[0040] Cellulose ether (NATROSOL 250HBR, Ashland Group); wetting agent (LCN407, Clariant Chemicals (China) Co., Ltd.); defoamer (AP7010, Haiming Sideqian (Shanghai) Chemical Co., Ltd.); neutralizing agent (AMP-95, Dow Chemical, USA); thickener (DR72, Dow Chemical, USA); antibacterial agent (RS, Tor International Trading (Shanghai) Co., Ltd.); film-forming aid (alcohol ester-12, Eastman Chemical Company, USA); emulsion (RS-9987, BADEFU Group Co., Ltd.); diatomaceous earth (C499, Guangzhou Honghai Chemical Technology Co., Ltd.); color paste (Guangdong Kedi New Material Technology Co., Ltd.); white sand (Quyang County Detai Mineral Products Co., Ltd.); potassium methylsilicate are all commercially available products; artificial composite rock chips (Jiangxi Tiansheng New Material Co., Ltd.); fluidized bed drying equipment (model GZQ3×0.30, Changzhou Pinzheng Drying Equipment Co., Ltd.).

[0041] Example 4

[0042] The preparation method of the stone-like coating based on hydrophobic modified rock flakes in Example 3.

[0043] Step B1: While stirring at 100-150 r / min, add water and wetting agent in sequence, then add hydrophobic modified rock chips, and soak for 0.5 h-24 h to obtain the accent color composition; Step B2: While stirring at 500-750 r / min, add water, cellulose ether, diatomaceous earth, wetting agent, defoamer, neutralizer, emulsion, film-forming aid, thickener, preservative and white sand in sequence, then add the main color rock chips and color paste in proportion, and stir evenly to obtain the main color composition; Step B3: Adjust the speed to 200-400 r / min, add the accent color composition of B1 to the main color composition of B2 after mixing and color matching, and stir for 5-15 min to obtain the stone-like coating based on hydrophobic modified rock chips.

[0044] Example 5

[0045] To verify the effectiveness of the present invention, the stone-like coating based on hydrophobically modified rock flakes in Example 3 was tested, and four sets of examples were prepared. The specific proportions and test results of these four sets of examples are detailed in Table 1. To further verify the effectiveness of the present invention, five different comparative examples were prepared. The specific composition and test results of the five comparative examples are shown in Tables 2 and 3.

[0046] Among them, Comparative Examples 1 and 5 used unmodified artificial composite rock chips as embellishment components. The resulting stone-like coatings exhibited water resistance and whitening defects. Furthermore, Comparative Example 1, which added 3% color paste to its stone-like coating formula, also showed reduced clarity of the embellishment dots. Comparative Example 2 used color paste as the main hue alone. The stone-like coating prepared using the method of this invention, with the same film thickness and without affecting the clarity of the embellishment dots, lacked sufficient coverage from the color paste, resulting in poor hiding power. Comparative Example 3 used only main-color rock chips as the main hue. The stone-like coating prepared using the method of this invention failed to encapsulate the white sand, resulting in white sand jumping in the film. Comparative Example 5 also uses only the main color rock flakes as the main hue. The stone-like coating prepared using the method of this invention, with adjustments to the ratio of rock flakes to white sand (increasing the amount of main color rock flakes and decreasing the amount of white sand), achieved a film hiding power of 9 points. The main color rock flakes could coat the white sand, but the small amount of white sand resulted in a weak film texture and strength. Comparative Example 4 also uses only color paste as the main hue. The stone-like coating prepared using the method of this invention, with a color paste addition of 7% for the same film thickness, exhibited poor clarity of the colored dots on the film.

[0047] In addition, the clarity of the paint film dots and the hiding power are evaluated on a scale of 1 to 10, from poor to good; the paint film thickness is 1.2mm ± 0.1mm for dry film.

[0048] Table 1. Correspondence Table of Formulation Data for Examples

[0049]

[0050] Table 2. Comparative Example Formulation Data Correspondence Table

[0051]

[0052]

[0053] Table 3. Comparative Example Formulation Data and Corresponding Effects

[0054]

[0055] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that an article or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such an article or apparatus. Without further limitations, an element defined by the phrase "comprising..." does not exclude the presence of other identical elements in the article or apparatus that includes that element.

[0056] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. The present invention has been described in detail with reference to preferred embodiments. Those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the present invention, and all such modifications and substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A stone-like coating, characterized in that: The product includes a main color composition and an accent color composition, wherein the accent color composition includes hydrophobically modified rock chips; the hydrophobically modified rock chips are composite rock chips that have been grafted onto the surface of potassium methylsilicate; the main components of the composite rock chips are 30-50% acrylic resin and 40-50% heavy calcium carbonate powder; the thickness of the composite rock chips is between 0.05mm and 0.10mm. The method for preparing the hydrophobically modified rock slices is as follows: Step A1: Soak the composite rock slices in an aqueous solution of potassium methylsilicate, with a mass concentration of 0.5%-10%, for 0.5-2 hours; Step A2: Dry the composite rock slices soaked in Step A1 at a temperature of 10℃-50℃ in an environment containing carbon dioxide for 0.5h-20h; Step A3: The rock slices obtained in step A2 are dried at a temperature of 50℃-105℃ and under gas conditions for 0.5h-24h to obtain hydrophobic modified rock slices. The primary color composition comprises, by weight parts: 10 to 28 parts water; Color paste 0.1 to 10 parts; Diatomaceous earth 0.5 to 3 parts; Cellulose ether 0.1 to 0.3 parts; Two to twelve pieces of rock fragments with the main color; 45-76 parts white sand; The accent color composition comprises, by weight parts: 10 to 20 parts water; 70-80 parts of hydrophobically modified rock fragments; 3 to 10 parts wetting agent.

2. The stone-like coating according to claim 1, characterized in that: The primary color composition also includes: Wetting agent 0.05 parts to 1 part; Defoamer 0.05-0.15 parts; Neutralizing agent 0.05-0.15 parts; Thickener 0.1-0.3 parts; 11-16 parts emulsion; Film-forming aid 0.6-1.1 parts; Preservative 0.1-0.2 parts.

3. The stone-like coating according to claim 1, characterized in that: The mass ratio of the main color composition to the accent color composition is 100:0.5~3, the SiO2 content in the diatomaceous earth is ≥90%, and the median particle size D50 is 10-14μm.

4. The stone-like coating according to claim 2, characterized in that: The color paste is one or more of titanium dioxide, iron oxide red, iron oxide yellow, carbon black, phthalocyanine blue, and phthalocyanine green; The white sand is natural mineral sand with a mixed gradation between 20 and 200 mesh. The primary color rock slice is a composite rock slice with a mesh size of 30-40 mesh, and the hydrophobic modified rock slice has a mesh size of 9-12 mesh.

5. The stone-like coating according to claim 2, characterized in that: The cellulose ether is hydroxyethyl cellulose ether; the wetting agent is alkyl polyoxyethylene ether; the defoamer is a mineral oil defoamer; the neutralizing agent includes any one or a combination of at least two of ammonia, 2-amino-2-methyl-1-propanol, diethanolamine, and triethanolamine; the thickener includes any one or a combination of at least two of alkali-swelling thickeners and polyurethane thickeners; the film-forming aid is dodecyl alcohol ester; the preservative includes any one or a combination of at least two of 2-methyl-4-isothiazolin-3-one, 1,2-benzisothiazolin-3-one, and 2-methyl-5-chloro-4-isothiazolin-3-one.

6. A method for preparing a stone-like coating, used to prepare the stone-like coating according to any one of claims 1-5, characterized in that: Step B1: While stirring at 100-150 r / min, add water and wetting agent in sequence, then add hydrophobic modified rock chips, and soak for 0.5h-24h to obtain the embellishment color composition; Step B2: While stirring at a speed of 500-750 r / min, add water, cellulose ether, diatomaceous earth, wetting agent, defoamer, neutralizer, emulsion, film-forming aid, thickener, preservative and white sand in sequence. Then, add the main color rock chips and color paste in proportion and stir evenly to obtain the main color composition. Step B3: Adjust the rotation speed to 200-400 r / min, add the B1 accent color composition to the main color composition in the mixed and tinted B2, stir for 5-15 min, and you will get the stone-like coating based on hydrophobic modified rock flakes.

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