Rock plate surface protection glaze and preparation method thereof

Abstract

The invention discloses protective glaze for the surface of a rock plate and a preparation method of the protective glaze. The protective glaze is prepared from the following components in parts by weight: 10 to 25 parts of potassium feldspar, 10 to 20 parts of albite, 10 to 15 parts of quartzite, 5 to 10 parts of kaolin, 4 to 10 parts of zinc oxide, 2 to 6 parts of aluminum oxide, 2 to 8 parts of strontium carbonate, 2 to 6 parts of polycarboxylic acid dispersing agent, 0.1 to 0.5 part of defoaming agent, 0.05 to 0.1 part of flatting agent and 40 to 55 parts of solvent. The invention also provides a preparation method of the composition. Compared with the prior art, the polycarboxylic acid dispersing agent provided by the invention has the advantages that the dispersity of inorganic materials in the glaze in a solvent is improved, so that the adhesive force and the stability of the glaze are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of rock slab glazes, and particularly to a protective glaze for the surface of a rock slab and a preparation method thereof. Background Art

[0002] A rock slab protective glaze is a vitreous thin layer material coated on the surface of a rock slab, which is made of oxides such as silicon, aluminum, potassium, sodium, calcium, magnesium, and additives such as a flux, a colorant, an opacifier, etc. through a specific formula and process. The protective glaze can endow the rock slab with good wear resistance, enabling it to withstand various frictions and scratches in daily use and not easily showing scratches. It also has excellent acid and alkali resistance, can resist the erosion of various chemical substances, and is not prone to chemical reactions that cause surface damage or discoloration. At the same time, it effectively prevents moisture from penetrating into the interior of the rock slab, preventing problems such as expansion and deformation caused by water absorption, and also helps to improve the stain resistance of the rock slab. It can also present a variety of gloss effects, such as high gloss, matte, and soft light, according to different production processes and formulas, and has a certain transparency, which can make the colors and textures on the surface of the rock slab clearer and more beautiful.

[0003] Current types include digital glazes, dry particles, and "precision carving" inks. Digital glazes are applied by an inkjet printer. The glaze layer is thin and uniform, with a fineness reaching the nanometer level. It can achieve the combination of "bright and matte", can also replace some mold effects and traditional pouring glazes, has a delicate texture, and has a matte feeling. Dry particles are frit ground to a certain fineness and present a vitreous state after firing. According to different formulas and processes, it can present a mirror effect, a diamond-like shining ice crystal light, and can also achieve a matte and frosted texture, with the characteristics of anti-slip and wear resistance. "Precision carving" inks are sprayed onto the surface of the rock slab by an inkjet printer and present a concave-convex texture effect after firing, which is suitable for the expression of modern textures such as geometry, cloth patterns, and wood grains, increasing the three-dimensional sense and artistic sense of the rock slab surface.

[0004] Chinese Patent Publication No. CN113387582A discloses a glaze specifically designed for ultra-thin ceramic rock slabs. Its system covers a surface glaze and a protective glaze, both of which contain components such as a water-soluble organic solvent, a wetting and leveling agent, an antifoaming agent, an anti-settling agent, and a dispersant. Specifically, the dry material of the surface glaze consists of albite, dolomite, high-aluminum bauxite, zirconium silicate, matte frit powder, etc., while the dry material of the protective glaze contains wollastonite, albite, kaolin, calcined talc, calcined zinc oxide, calcined alumina, bright frit powder, etc., and the dispersant uses a self-made anhydrous polyacrylic acid dispersant. This glaze is suitable for the high-pressure spraying glaze process. When applied to ultra-thin ceramic rock slabs, it can significantly reduce the defect rate after firing while maintaining the strength of the green body, with low glazing cost and high product quality.

[0005] Chinese Patent Publication No. CN113444399A discloses a ceramic digital protective glaze ink, its preparation method and application. The raw materials for preparing the ceramic digital protective glaze ink include a solvent, a super-dispersant, powder materials, a surfactant and an anti-settling agent. After the ceramic digital protective glaze ink is printed on the surface of a slab tile, it exhibits good color development effect, soft gloss, excellent stain resistance and wear resistance, and delicate hand feeling.

[0006] Both the digital glaze and the ink are printed by an inkjet printer. The digital glaze layer is thin and uniform, and can achieve a combination of bright and matte. The ink forms concave-convex textures on the surface of the slab through the accumulation of high-viscosity ink, and can present a good three-dimensional touch and visual hierarchy after firing. However, both the digital glaze and the ink contain inorganic pigments, and the dispersibility of inorganic pigments in the solvent is poor, resulting in problems such as easy caking and sedimentation, which affect the final forming effect of the glaze. Summary of the Invention

[0007] In view of the above-mentioned defects of the prior art, the technical problem to be solved by the present invention is to provide a protective glaze for the surface of a slab and its preparation method.

[0008] In order to solve the problem of the dispersibility of inorganic materials in the glaze, it is usually necessary to add a dispersant to improve the dispersion effect. At present, polycarboxylates are the most widely used in the prior art. Polycarboxylate dispersants have good steric hindrance effects, reduce the agglomeration between particles, have good dispersion effects, and strong stability, and are not easily interfered by pH and electrolytes. However, it has the risk of thermal decomposition at high temperatures. The glaze ultimately needs to be fired at high temperatures, and most polycarboxylates may carbonize and fail at high temperatures.

[0009] Therefore, the present invention provides a polycarboxylate dispersant, which can not only better solve the problem of the dispersibility of inorganic pigments, but also has better high-temperature stability, and will not affect its dispersion effect even at high-temperature firing. The polycarboxylic acid dispersant is obtained by free radical polymerization of acrylic acid, functional monomers and 4-vinyl-2-pyridinecarboxylic acid under the action of an initiator. In an aqueous solution, it will ionize carboxylate ions, making itself negatively charged, so as to adsorb on the particle surface. Due to the steric hindrance and electrostatic repulsion effects of the long chain of polycarboxylic acid, "hindrances" can be formed between inorganic material particles, reducing agglomeration, so it is not easy to settle in the solvent. And polycarboxylates can reduce the surface tension at the interface between the glaze and water, making the glaze particles easier to be wetted by water. This helps the dispersion of glaze particles in water and also improves the stability of the glaze slurry. The polycarboxylate provided by the present invention has a pyridine group and contains lone pair electrons, so it can form a coordination bond with metal ions, and thus can further improve the adsorption of the dispersant on the surface of glaze particles, resulting in a better dispersion effect, which is beneficial to the later forming of the glaze.

[0010] To achieve the above object, the present invention provides a protective glaze for the surface of a rock slab, comprising the following components in parts by weight: 10-25 parts of potassium feldspar, 10-20 parts of albite, 10-15 parts of quartz, 5-10 parts of kaolin, 4-10 parts of zinc oxide, 2-6 parts of alumina, 2-8 parts of strontium carbonate, 2-6 parts of polycarboxylic acid dispersant, 0.1-0.5 part of defoaming agent, 0.05-0.1 part of leveling agent, and 40-55 parts of solvent.

[0011] The preparation method of the polycarboxylic acid dispersant comprises the following steps: Add acrylic acid, functional monomer and 4-vinyl-2-pyridinecarboxylic acid into N,N-dimethylformamide, stir evenly, then dropwise add benzoyl peroxide, and stir at 80-90 °C under an inert atmosphere for 3-4 h. After cooling to room temperature, adjust the pH to obtain the polycarboxylic acid dispersant.

[0012] Further, the functional monomer is one of ethyl acrylate, butyl acrylate or 3-methacryloxypropylmethyldimethoxysilane.

[0013] Further, the molar ratio of acrylic acid, functional monomer, 4-vinyl-2-pyridinecarboxylic acid to benzoyl peroxide is 1:1-1.2:0.5-1.5:0.001-0.01.

[0014] Further, the range of the pH is 6-7.

[0015] Further, the defoaming agent is an organosilicon defoaming agent.

[0016] Further, the leveling agent is an organosilicon leveling agent.

[0017] Further, the solvent is one of ethanol, isopropanol, glycerol, butyl acetate or diethylene glycol monobutyl ether.

[0018] Preferably, the preparation method of the polycarboxylic acid dispersant comprises the following steps: Add acrylic acid, functional monomer and 4-vinyl-2-pyridinecarboxylic acid into N,N-dimethylformamide with a volume 4-8 times the total volume of the three, stir evenly, then dropwise add benzoyl peroxide, and the molar ratio of acrylic acid, functional monomer, 4-vinyl-2-pyridinecarboxylic acid to benzoyl peroxide is 1:1-1.2:0.5-1.5:0.001-0.01. Stir at 80-90 °C under an inert atmosphere for 3-4 h, and adjust the pH to 6-7 after cooling to room temperature to obtain it.

[0019] A preparation method of a protective glaze for the surface of a rock slab comprises the following steps: Mix each component according to the ratio and grind evenly to obtain the protective glaze for the surface of the rock slab.

[0020] Further, the grinding time is 4 to 6 hours.

[0021] Further, the grinding speed is 1000 to 1500 rpm.

[0022] Advantages of the present invention: 1. In the present invention, polycarboxylate dispersant is obtained by free radical polymerization of acrylic acid, functional monomer and 4-vinyl-2-pyridinecarboxylic acid under the action of initiator. Through steric hindrance and electrostatic repulsion effects, "hindrance" is formed between inorganic material particles, reducing agglomeration. Therefore, it is not easy to settle in the solvent. And polycarboxylate can reduce the surface tension at the interface between the glaze and water, making the glaze particles easier to be wetted by water. This helps the dispersion of glaze particles in water and also improves the stability of the glaze slurry.

[0023] 2. Compared with the prior art, the polycarboxylate provided by the present invention has a pyridine group and contains lone pair electrons, so it can form coordination bonds with metal ions, and thus can further improve the adsorption of the dispersant on the surface of glaze particles, resulting in better dispersion effect, which is beneficial to the shaping of the glaze in the later stage.

[0024] 3. Compared with the prior art, the polycarboxylate dispersant provided by the present invention can not only better solve the dispersion problem of inorganic pigments, but also has better high-temperature stability, and will not affect its dispersion effect even during high-temperature firing. Specific embodiments

[0025] Defoamer BYK-052, sourced from BYK Chemie.

[0026] Leveling agent BYK-306, sourced from BYK Chemie.

[0027] Polyacrylamide, model: AN 923 PGO, sourced from SNF Floerger.

[0028] Example 1

[0029] A preparation method of a protective glaze for the surface of a rock slab, comprising the following steps: By weight, 20 parts of potassium feldspar, 15 parts of sodium feldspar, 12 parts of quartz, 8 parts of kaolin, 6 parts of zinc oxide, 4 parts of alumina, 3 parts of strontium carbonate, 4 parts of polycarboxylate dispersant, 0.4 part of BYK-052, 0.06 part of BYK-306 and 50 parts of isopropanol are mixed evenly and then ground at 1200 rpm for 4 hours to obtain the protective glaze for the surface of the rock slab.

[0030] The preparation method of the polycarboxylate dispersant comprises the following steps: Acrylic acid, ethyl acrylate and 4-vinyl-2-pyridinecarboxylic acid were added to N,N-dimethylformamide in a volume 5 times the total volume of the three. After stirring evenly, benzoyl peroxide was added dropwise. The molar ratio of acrylic acid, ethyl acrylate, 4-vinyl-2-pyridinecarboxylic acid to benzoyl peroxide was 1:1.1:1:0.005. Stirring was carried out at 85 °C under an inert atmosphere for 4 h. After cooling to room temperature, the pH was adjusted to 7 to obtain the product.

[0031] Example 2

[0032] A preparation method of a protective glaze for the surface of a rock slab, comprising the following steps: By weight, 20 parts of potassium feldspar, 15 parts of sodium feldspar, 12 parts of quartz stone, 8 parts of kaolin, 6 parts of zinc oxide, 4 parts of alumina, 3 parts of strontium carbonate, 4 parts of polycarboxylic acid dispersant, 0.4 part of BYK-052, 0.06 part of BYK-306 and 50 parts of isopropanol were mixed evenly and then ground. Grinding was carried out at 1200 rpm for 4 h to obtain the protective glaze for the surface of the rock slab.

[0033] The preparation method of the polycarboxylic acid dispersant comprises the following steps: Acrylic acid, butyl acrylate and 4-vinyl-2-pyridinecarboxylic acid were added to N,N-dimethylformamide in a volume 5 times the total volume of the three. After stirring evenly, benzoyl peroxide was added dropwise. The molar ratio of acrylic acid, butyl acrylate, 4-vinyl-2-pyridinecarboxylic acid to benzoyl peroxide was 1:1.1:1:0.005. Stirring was carried out at 85 °C under an inert atmosphere for 4 h. After cooling to room temperature, the pH was adjusted to 7 to obtain the product.

[0034] Example 3

[0035] A preparation method of a protective glaze for the surface of a rock slab, comprising the following steps: By weight, 20 parts of potassium feldspar, 15 parts of sodium feldspar, 12 parts of quartz stone, 8 parts of kaolin, 6 parts of zinc oxide, 4 parts of alumina, 3 parts of strontium carbonate, 4 parts of polycarboxylic acid dispersant, 0.4 part of BYK-052, 0.06 part of BYK-306 and 50 parts of isopropanol were mixed evenly and then ground. Grinding was carried out at 1200 rpm for 4 h to obtain the protective glaze for the surface of the rock slab.

[0036] The preparation method of the polycarboxylic acid dispersant comprises the following steps: Acrylic acid, 3-methacryloxypropylmethyldimethoxysilane and 4-vinyl-2-pyridinecarboxylic acid were added to N,N-dimethylformamide in a volume 5 times the total volume of the three. After stirring evenly, benzoyl peroxide was added dropwise. The molar ratio of acrylic acid, 3-methacryloxypropylmethyldimethoxysilane, 4-vinyl-2-pyridinecarboxylic acid to benzoyl peroxide was 1:1.1:1:0.005. Stirring was carried out at 85 °C under an inert atmosphere for 4 h. After cooling to room temperature, the pH was adjusted to 7 to obtain the product.

[0037] Comparative Example 1

[0038] A method for preparing a protective glaze for the surface of a rock slab, comprising the following steps: By weight, 20 parts of potassium feldspar, 15 parts of sodium feldspar, 12 parts of quartz, 8 parts of kaolin, 6 parts of zinc oxide, 4 parts of alumina, 3 parts of strontium carbonate, 4 parts of polyacrylamide, 0.4 part of BYK-052, 0.06 part of BYK-306 and 50 parts of isopropanol are mixed evenly and then ground. Grinding is carried out at 1200 rpm for 4 h to obtain the protective glaze for the surface of the rock slab.

[0039] Comparative Example 2

[0040] A method for preparing a protective glaze for the surface of a rock slab, comprising the following steps: By weight, 20 parts of potassium feldspar, 15 parts of sodium feldspar, 12 parts of quartz, 8 parts of kaolin, 6 parts of zinc oxide, 4 parts of alumina, 3 parts of strontium carbonate, 4 parts of polycarboxylic acid dispersant, 0.4 part of BYK-052, 0.06 part of BYK-306 and 50 parts of isopropanol are mixed evenly and then ground. Grinding is carried out at 1200 rpm for 4 h to obtain the protective glaze for the surface of the rock slab.

[0041] The preparation method of the polycarboxylic acid dispersant comprises the following steps: Acrylic acid, 3-methacryloxypropylmethyldimethoxysilane and 5-hexenoic acid are added to N,N-dimethylformamide which is 5 times the total volume of the three. After stirring evenly, benzoyl peroxide is added dropwise. The molar ratio of acrylic acid, 3-methacryloxypropylmethyldimethoxysilane, 5-hexenoic acid to benzoyl peroxide is 1:1.1:1:0.005. Stirring is carried out at 85 °C under an inert atmosphere for 4 h. After cooling to room temperature, the pH is adjusted to 7 to obtain the product.

[0042] Test Example 1

[0043] The glaze materials of the examples and comparative examples were tested for sedimentation rate. The glaze materials were placed in a bottle and stored sealed at 70 °C for 7 d. After the sample was inverted for 5 min, the glaze material hanging on the bottle wall was allowed to drip. The weight of the remaining glaze material in the glass bottle was weighed and recorded, and the ratio between the weight of the remaining glaze material and the total weight of the glaze material was calculated, which was the sedimentation rate. The specific results are shown in Table 1.

[0044] Table 1

[0045] The sedimentation rate directly reflects the stability of the glaze in the suspension. A low sedimentation rate indicates that the glaze particles can be evenly suspended in the medium and are not prone to sinking, indicating good suspension stability of the glaze; a high sedimentation rate indicates poor suspension stability of the glaze, and the particles are likely to settle under the action of gravity, which may lead to layering of the glaze slurry and affect the subsequent glazing process and glaze surface quality. When the glaze has good dispersibility, the particles are evenly distributed in the medium, and the mutual forces between them make it difficult for them to aggregate and settle, resulting in a lower sedimentation rate.

[0046] As can be seen from Table 1, compared with Comparative Example 1, the glaze prepared in the Example has a lower sedimentation rate, which may be due to the relatively low charge density of polyacrylamide and the weak electrostatic repulsion. In the glaze system, for some particles with higher charges, polyacrylamide may not be able to provide sufficient electrostatic repulsion to achieve good dispersion, and the dispersion effect may be limited. Compared with Comparative Example 2, in the Example, 4-vinyl-2-pyridinecarboxylic acid is involved in the preparation of the polycarboxylate. Pyridine contains lone pair electrons, so it can form coordination bonds with metal ions, and thus can further improve the adsorption of the dispersant on the surface of the glaze particles, resulting in a better dispersion effect.

[0047] The polycarboxylate dispersant in the Example will ionize carboxylate ions in the aqueous solution, making itself negatively charged, and thus adsorbing on the particle surface. Due to the steric hindrance and electrostatic repulsion effects of the long chain of the polycarboxylic acid, it can form an "obstruction" between the inorganic material particles, reducing aggregation, so it is not prone to sedimentation in the solvent. Moreover, the polycarboxylate can reduce the surface tension at the interface between the glaze and water, making the glaze particles easier to be wetted by water. This helps the dispersion of the glaze particles in water and also improves the stability of the glaze slurry. In Example 3, 3-methacryloxypropylmethyldimethoxysilane is used as the functional monomer. The addition of 3-methacryloxypropylmethyldimethoxysilane can better enhance the steric hindrance effect of the polycarboxylate dispersant, thereby improving the dispersion effect. Therefore, the glaze in Example 3 has the lowest sedimentation rate.

[0048] Test Example 2

[0049] The glazes prepared in the Example and the Comparative Example were glazed on the same kind of rock slab body by the inkjet process, and the spraying amount was 50 g / m 2 , and after firing at 1200 °C, the abrasion resistance of the obtained glaze surface was tested. The test method refers to GB / T 3810.7-2016 Test methods for ceramic tiles - Part 7: Determination of abrasion resistance of glazed tiles on the surface. The test results are shown in Table 2.

[0050] Table 2

[0051] As can be seen from Table 1, the glaze surface obtained from the glaze prepared in Example 3 has better wear resistance. This may be because the dispersant can evenly disperse the glaze particles in the glaze slurry and avoid agglomeration. During the firing process, the evenly dispersed particles will melt and crystallize more uniformly, forming a glaze layer with a uniform microstructure, dense texture, and no obvious defects, thereby improving the wear resistance of the glaze layer. Polycarboxylate dispersants can evenly disperse the glaze particles through electrostatic repulsion and steric hindrance effects. The structure of the fired glaze layer is uniform and has good wear resistance. In Example 3, 3-methacryloxypropylmethyldimethoxysilane is used as a functional monomer, which can effectively improve the stability of the dispersant at high temperatures, thus ensuring the effectiveness of the dispersant.

[0052] The dispersant evenly disperses the glaze particles, which helps the glaze slurry to spread and adhere evenly on the surface of the green body. During the firing process, it can form a good bond with the green body. This good bond can prevent the glaze layer from peeling off the surface of the green body easily when subjected to external frictional force, thereby improving the overall wear resistance of the glaze layer. In addition, the dispersant can adjust the rheology of the glaze, making the glaze have appropriate fluidity at high temperatures. During the firing process, the glaze with good fluidity can better fill the tiny unevenness on the surface of the green body, forming a smooth and flat glaze layer. The smooth glaze surface can reduce the frictional resistance, lower the degree of wear, and improve the wear resistance.

[0053] However, in Examples 1-2 and the control example, due to poor stability at high temperatures, the dispersion effect of the glaze is affected, which further affects the rheology of the glaze and its bonding with the green body. Therefore, the wear resistance is inferior to that of Example 3.

[0054] The preferred specific embodiments of the present invention have been described in detail above. It should be understood that those of ordinary skill in the art can make many modifications and variations based on the concept of the present invention without creative work. Therefore, all technical solutions that can be obtained by those skilled in the art in the technical field of the present invention based on the concept of the present invention through logical analysis, reasoning, or limited experiments on the basis of the prior art should be within the protection scope determined by the claims.

Claims

1. A protective glaze for the surface of a rock slab, characterized in that, It comprises the following components in parts by weight: 10-25 parts of potassium feldspar, 10-20 parts of albite, 10-15 parts of quartz, 5-10 parts of kaolin, 4-10 parts of zinc oxide, 2-6 parts of alumina, 2-8 parts of strontium carbonate, 2-6 parts of polycarboxylic acid dispersant, 0.1-0.5 part of defoamer, 0.05-0.1 part of leveling agent and 40-55 parts of solvent; The preparation method of the polycarboxylic acid dispersant comprises the following steps: Adding acrylic acid, functional monomer and 4-vinyl-2-pyridinecarboxylic acid into N,N-dimethylformamide, stirring evenly, dropping benzoyl peroxide, stirring at 80-90 °C under an inert atmosphere for 3-4 h, and adjusting the pH after cooling to room temperature to obtain the polycarboxylic acid dispersant.

2. The protective glaze on the surface of the rock slab according to claim 1, characterized in that, The functional monomer is one of ethyl acrylate, butyl acrylate or 3-methacryloxypropylmethyldimethoxysilane.

3. The protective glaze on the surface of the rock slab according to claim 1, characterized in that, The molar ratio of the acrylic acid, functional monomer, 4-vinyl-2-pyridinecarboxylic acid to benzoyl peroxide is 1:1-1.2:0.5-1.5:0.001-0.

01.

4. The protective glaze on the surface of the rock slab according to claim 1, characterized in that, The range of the pH is 6-7.

5. The protective glaze on the surface of the rock slab according to claim 1, characterized in that, The defoamer is an organosilicon defoamer.

6. The protective glaze on the surface of the rock slab according to claim 1, characterized in that, The leveling agent is an organosilicon leveling agent.

7. The protective glaze on the surface of the rock slab according to claim 1, characterized in that, The solvent is one of ethanol, isopropanol, glycerol, butyl acetate or diethylene glycol monobutyl ether.

8. The preparation method of the protective glaze on the surface of the rock slab according to any one of claims 1 to 7, characterized in that, It comprises the following steps: Mixing the components evenly according to the ratio and then grinding to obtain the protective glaze on the surface of the rock slab.

9. The preparation method of the protective glaze on the surface of the rock slab according to claim 8, characterized in that, The grinding time is 4-6 h.

10. The preparation method of the protective glaze on the surface of the rock slab according to claim 8, characterized in that, The grinding speed is 1000-1500 rpm.

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