CN118495917B - High-strength ceramic tile and preparation method and application thereof - Google Patents

Abstract

The invention belongs to the technical field of ceramics, and discloses a high-strength ceramic tile, a preparation method and application thereof. The ceramic tile of the invention comprises a blank, and the raw materials of the blank comprise: clay, quartz, feldspar, talc, bauxite, bentonite and modified fillers; the preparation process of the modified filler comprises the following steps: dissolving a silane coupling agent in a solvent, adding chopped glass fibers, and performing ultrasonic dispersion to obtain a dispersion; adding nano silicon nitride into the dispersion liquid, and performing ultrasonic dispersion to obtain a mixed liquid; and (3) dissolving the fluorocarbon surfactant in a solvent, adding the solvent into the mixed solution, stirring, separating and collecting solid matters, and drying to obtain the modified filler. According to the invention, the modified filler is added into the raw material of the ceramic blank, wherein the modified filler modifies the chopped glass fibers and the nano silicon nitride through the silane coupling agent and the fluorocarbon surfactant, so that agglomeration is avoided, and the chopped glass fibers and the nano silicon nitride can be uniformly dispersed, so that the glass fibers and the nano silicon nitride are uniformly distributed in the blank, and the strength of the ceramic tile is improved.

Description

A high-strength ceramic brick and its preparation method and application

Technical Field

The invention belongs to the technical field of ceramics, and in particular relates to a high-strength ceramic brick and a preparation method and application thereof.

Background Art

Ceramic materials are a type of inorganic non-metallic material made from natural or synthetic compounds through molding and high-temperature sintering. It has the advantages of high melting point, high hardness, high wear resistance and oxidation resistance. Ceramic bricks are plate-shaped or block-shaped ceramic products made from clay and other inorganic non-metallic raw materials through molding, sintering and other processes. They are used to decorate and protect the walls and floors of buildings and structures. They are usually formed at room temperature by dry pressing, extrusion or other molding methods, then dried and fired at a certain temperature.

At present, most methods to improve the strength of ceramics use reinforcing phase reinforcement. Reinforcing phase reinforcement is to directly add the reinforcing phase into the green body. After sintering, the reinforcing phase is dispersed in the ceramic. When the crack expands, the reinforcing phase will cause the crack to bend. There are many types of reinforcing phases that can be added to the ceramic green body, among which powders include aluminum oxide, silicon carbide, silicon nitride, etc. However, these powders have a large specific surface area, which makes them easy to agglomerate. They are easy to enrich when used to prepare ceramics, and the strength improvement of the ceramics is not obvious, and may even decrease; at the same time, the large specific surface area leads to more interfaces between it and the green body material, and the poor interface bonding performance will also lead to poor improvement of the strength of the ceramic.

Therefore, it is necessary to provide a high-strength ceramic tile.

Summary of the invention

The present invention aims to solve at least one of the technical problems existing in the above-mentioned prior art. To this end, the present invention provides a high-strength ceramic tile and a preparation method and application thereof. The ceramic tile has high strength, good flexural resistance and hardness.

In a first aspect, the present invention provides a high-strength ceramic tile, the high-strength ceramic tile comprises a green body, the raw materials of the green body comprise: clay, quartz, feldspar, talc, bauxite, bentonite and modified filler;

The preparation process of the modified filler is as follows: dissolving a silane coupling agent in a solvent, adding short-cut glass fibers, and performing ultrasonic dispersion to obtain a dispersion;

Adding nano silicon nitride to the dispersion liquid and performing ultrasonic dispersion to obtain a mixed liquid;

The fluorocarbon surfactant is dissolved in a solvent, and then added into the mixed solution, stirred, and the solid matter is separated and collected, and dried to obtain the modified filler.

In some embodiments of the present invention, the high-strength ceramic tile also includes a strengthening coating, which is located on the surface of the green body. The thermal expansion coefficient of the strengthening coating is smaller than the thermal expansion coefficient of the green body. The raw materials of the strengthening coating include: wollastonite, quartz, alumina and a binder solution.

In some embodiments of the present invention, the thickness of the strengthening coating is 200-400 μm.

In some embodiments of the present invention, the raw materials of the green body include, by weight: 40-60 parts of clay, 25-35 parts of quartz, 6-12 parts of feldspar, 1-3 parts of talc, 4-8 parts of bauxite, 2-6 parts of bentonite and 0.1-0.8 parts of modified filler.

In some embodiments of the present invention, the mass ratio of the chopped glass fiber, nano-silicon nitride, silane coupling agent, fluorocarbon surfactant and solvent is (10-15):(1-5):(0.5-2):(1-5):150.

In some embodiments of the present invention, the diameter of the chopped glass fibers is 20-40 μm; and/or the length of the chopped glass fibers is 50-150 μm.

In some embodiments of the present invention, the particle size of the nano silicon nitride is 50-150 nm.

In some embodiments of the present invention, the mass ratio of wollastonite, quartz, alumina and binder solution is 1:(0.4-0.6):(1-5):(10-50) in parts by mass.

In some embodiments of the present invention, the silane coupling agent includes at least one of silane coupling agents KH-550, KH-560 and KH-570.

In some embodiments of the present invention, the fluorocarbon surfactant includes at least one of the fluorocarbon surfactants TF-281, TF-310 and FC-4430.

In some embodiments of the present invention, the binder solution contains at least one of polyvinyl alcohol, carboxymethyl cellulose, dextrin, and gum arabic, and the concentration of the binder solution is 1-3 wt %.

In some embodiments of the present invention, the solvent includes at least one of anhydrous ethanol, acetone and methanol.

In some embodiments of the present invention, the ultrasonic power of the ultrasonic dispersion is 550-650 W, and the ultrasonic time is 30-60 min.

In some embodiments of the present invention, the stirring speed is 500-1000 r/min, and the stirring time is 60-90 min.

The second aspect of the present invention provides a method for preparing the high-strength ceramic brick according to the first aspect of the present invention, comprising the following steps:

The clay, quartz, feldspar, talc, bauxite, bentonite and modified filler are mixed, wet ball milled and spray granulated to obtain green body powder;

Pressing the green body powder into a shape and biscuit-firing the green body to obtain a biscuit;

The bisque-fired blank is sintered to obtain the high-strength ceramic brick.

In some embodiments of the present invention, the temperature of the spray granulation is 400-550°C.

In some embodiments of the present invention, the biscuit calcining temperature is 600-700° C.; and/or the biscuit calcining time is 20-40 min.

In some embodiments of the present invention, the sintering temperature is 1150-1250° C.; and/or the sintering heating rate is 3-5° C./min; and/or the sintering time is 20-40 min.

In some embodiments of the present invention, before sintering, the following steps are further included:

Wollastonite, quartz and alumina are mixed, wet ball-milled once, and dried to obtain coating powder;

The coating powder and the binder solution are mixed and wet-milled for a second time to obtain a coating slurry;

The coating slurry is applied on the surface of the bisque fired body and dried.

The third aspect of the present invention provides application of the high-strength ceramic brick described in the first aspect of the present invention in the field of construction.

Compared with the prior art, the beneficial effects of the present invention are as follows:

1. The present invention adds modified fillers to the raw materials of the ceramic body, wherein the modified fillers modify the chopped glass fibers and nano-silicon nitride through silane coupling agents and fluorocarbon surfactants. When the modified fillers are mixed with other raw materials of the body, the modified fillers can provide interfacial wettability with extremely low surface tension. The modified fillers have high interfacial compatibility and low surface binding energy with other raw materials, can be well compatible and mixed, avoid agglomeration, and can be evenly dispersed, so that the glass fibers and nano-silicon nitride are evenly distributed in the body, thereby improving the strength of the ceramic tile.

2. The modified filler selected by the present invention is to add short glass fibers to a silane coupling agent and ultrasonically disperse them to improve the coating efficiency of the silane coupling agent, and then add nano-silicon nitride to a dispersion containing a silane coupling agent and short glass fibers to prevent the nano-silicon nitride from agglomerating. The nano-silicon nitride can be well distributed in the gaps between the short glass fibers, thereby improving the stability and activity of the nano-silicon nitride. The silane coupling agent forms a first layer of adsorption on the surfaces of the short glass fibers and the nano-silicon nitride; then, a fluorocarbon surfactant is added. When the fluorocarbon surfactant reaches a certain concentration, a sol/micelle is formed, and the filler is dispersed again under stirring to attach a fluorocarbon molecular film. The fluorocarbon surfactant forms a second layer of adsorption on the surfaces of the short glass fibers and the nano-silicon nitride, thereby improving the interface bonding performance between the modified filler and the blank.

3. The present invention arranges a strengthening coating on the surface of the green body. Wollastonite, quartz and alumina are used as raw materials to form a strengthening coating with a thermal expansion coefficient smaller than that of the green body on the surface of the green body. The strengthening coating can play a role of prestress strengthening, introduce compressive stress on the surface of the ceramic green body, and form a synergistic strengthening with the strengthening of the green body by the modified filler, thereby improving the overall strength of the ceramic tile; the flexural strength of the ceramic tile of the present invention is greater than 50MPa, and the Mohs hardness can reach 7.

DETAILED DESCRIPTION

The present invention is further described in detail below by specific examples. The raw materials, reagents or devices used in the examples can be obtained from conventional commercial sources or by prior art methods unless otherwise specified. Unless otherwise specified, the experiments or test methods are conventional methods in the art.

Example 1: High-strength ceramic brick and its preparation

A high-strength ceramic tile comprises a body and a strengthening coating coated on the surface of the body, wherein the thickness of the strengthening coating is 400 μm;

The green body includes the following raw materials in parts by weight: 50 parts of clay, 30 parts of quartz, 8 parts of feldspar, 2 parts of talc, 6 parts of bauxite, 4 parts of bentonite and 0.5 parts of modified filler;

The modified filler is prepared from chopped glass fiber, nano silicon nitride, silane coupling agent, fluorocarbon surfactant and solvent in a mass ratio of 12:3:1:3:150; wherein the diameter of the chopped glass fiber is 30 μm and the length is 100 μm; the particle size of the nano silicon nitride is 100 nm; the silane coupling agent is KH-550, the fluorocarbon surfactant is TF-281, and the solvent is anhydrous ethanol;

The strengthening coating is prepared from wollastonite, quartz, alumina and a binder solution in a mass ratio of 1:0.5:3:30; wherein the binder solution is a 1wt% carboxymethyl cellulose aqueous solution.

The preparation method of the modified filler comprises the following steps:

(1) Dissolve KH-550 silane coupling agent in part of anhydrous ethanol, add chopped glass fibers, and disperse them ultrasonically at 600 W for 30 min to obtain a dispersion;

(2) adding nano silicon nitride to the dispersion liquid, and dispersing it ultrasonically at 600 W for 30 min to obtain a mixed liquid;

(3) Dissolve TF-281 fluorocarbon surfactant in the remaining anhydrous ethanol, add it to the mixed solution while stirring, stir at 800 r/min for 60 min, separate and collect the solid, and dry the solid at 80°C to obtain a modified filler.

The method for preparing the above-mentioned high-strength ceramic brick comprises the following steps:

(1) Clay, quartz, feldspar, talc, bauxite, bentonite and modified filler are mixed, water is added (the mass ratio of raw materials to water is 1:0.5), wet ball milling is performed, and spray granulation is performed at 500°C to obtain green body powder;

(2) Pressing the green body powder into a shape, and biscuit-sintering the green body at 650° C. for 30 min to obtain a biscuit;

(3) wollastonite, quartz and alumina are mixed, water is added (the mass ratio of raw materials to water is 1:0.5), wet ball milling is performed once, and drying is performed to obtain a coating powder; the coating powder is mixed with a 1wt% carboxymethyl cellulose aqueous solution, water is added (the mass ratio of raw materials to water is 1:0.5), and wet ball milling is performed twice to obtain a coating slurry;

(4) Apply the coating slurry on each surface of the bisque-fired body, dry it, and then sinter it to obtain a ceramic tile; the sintering process is as follows: at room temperature (25±2°C), heat up to 1200°C at a rate of 4°C/min and keep it at that temperature for 30 minutes.

Example 2: High-strength ceramic brick and its preparation

A high-strength ceramic tile comprises a body and a strengthening coating coated on the surface of the body, wherein the thickness of the strengthening coating is 300 μm;

The green body includes the following raw materials in parts by weight: 40 parts of clay, 35 parts of quartz, 6 parts of feldspar, 3 parts of talc, 4 parts of bauxite, 6 parts of bentonite and 0.1 parts of modified filler;

The modified filler is prepared from chopped glass fiber, nano silicon nitride, silane coupling agent, fluorocarbon surfactant and solvent in a mass ratio of 10:5:0.5:5:150; wherein the diameter of the chopped glass fiber is 20 μm and the length is 50 μm; the particle size of the nano silicon nitride is 50 nm; the silane coupling agent is KH-560, the fluorocarbon surfactant is TF-310, and the solvent is acetone;

The strengthening coating is prepared from wollastonite, quartz, alumina and a binder solution in a mass ratio of 1:0.4:5:10; wherein the binder solution is a 1wt% carboxymethyl cellulose aqueous solution.

The preparation method of the modified filler comprises the following steps:

(1) Dissolve KH-560 silane coupling agent in part of anhydrous ethanol, add chopped glass fibers, and disperse them ultrasonically at 550W for 30 minutes to obtain a dispersion;

(2) adding nano silicon nitride to the dispersion liquid, and dispersing it ultrasonically at 550W for 30 minutes to obtain a mixed liquid;

(3) Dissolve TF-310 fluorocarbon surfactant in the remaining anhydrous ethanol, add it to the mixed solution while stirring, stir at 500 r/min for 90 min, separate and collect the solid, and dry the solid at 80°C to obtain a modified filler.

The method for preparing the above-mentioned high-strength ceramic brick comprises the following steps:

(1) Clay, quartz, feldspar, talc, bauxite, bentonite and modified filler are mixed, water is added (the mass ratio of raw materials to water is 1:0.5), wet ball milling is performed, and spray granulation is performed at 450°C to obtain green body powder;

(2) Pressing the green body powder into a shape, and biscuit-sintering the green body at 600° C. for 30 min to obtain a biscuit;

(3) wollastonite, quartz and alumina are mixed, water is added (the mass ratio of raw materials to water is 1:0.5), wet ball milling is performed once, and drying is performed to obtain a coating powder; the coating powder is mixed with a 1wt% carboxymethyl cellulose aqueous solution, water is added (the mass ratio of raw materials to water is 1:0.5), and wet ball milling is performed twice to obtain a coating slurry;

(4) Apply the coating slurry on each surface of the bisque-fired body, dry it, and then sinter it to obtain a ceramic tile; the sintering process is: heating at room temperature at 3°C/min to 1150°C and keeping it at that temperature for 40 minutes.

Example 3: High-strength ceramic brick and its preparation

A high-strength ceramic tile comprises a body and a strengthening coating coated on the surface of the body, wherein the thickness of the strengthening coating is 200 μm;

The green body includes the following raw materials in parts by weight: 60 parts of clay, 25 parts of quartz, 12 parts of feldspar, 1 part of talc, 8 parts of bauxite, 2 parts of bentonite and 0.8 parts of modified filler;

The modified filler is prepared from chopped glass fiber, nano silicon nitride, silane coupling agent, fluorocarbon surfactant and solvent in a mass ratio of 15:1:2:1:150; wherein the diameter of the chopped glass fiber is 40 μm and the length is 150 μm; the particle size of the nano silicon nitride is 150 nm; the silane coupling agent is KH-570, the fluorocarbon surfactant is FC-4430, and the solvent is methanol;

The strengthening coating is prepared from wollastonite, quartz, alumina and a binder solution in a mass ratio of 1:0.6:1:50; wherein the binder solution is a 1wt% carboxymethyl cellulose aqueous solution.

The preparation method of the modified filler comprises the following steps:

(1) Dissolve KH-570 silane coupling agent in part of anhydrous ethanol, add chopped glass fibers, and disperse them ultrasonically at 650W for 30 minutes to obtain a dispersion;

(2) adding nano silicon nitride to the dispersion liquid, and dispersing it ultrasonically at 650W for 30 minutes to obtain a mixed liquid;

(3) Dissolve FC-4430 fluorocarbon surfactant in the remaining anhydrous ethanol, add it to the mixed solution while stirring, stir at 1000 r/min for 60 min, separate and collect the solid, and dry the solid at 80°C to obtain a modified filler.

The method for preparing the above-mentioned high-strength ceramic brick comprises the following steps:

(1) Clay, quartz, feldspar, talc, bauxite, bentonite and modified filler are mixed, water is added (the mass ratio of raw materials to water is 1:0.5), wet ball milling is performed, and spray granulation is performed at 550°C to obtain green body powder;

(2) Pressing the green body powder into a shape, and biscuit-sintering the green body at 700°C for 20 minutes to obtain a biscuit;

(3) wollastonite, quartz and alumina are mixed, water is added (the mass ratio of raw materials to water is 1:0.5), wet ball milling is performed once, and drying is performed to obtain a coating powder; the coating powder is mixed with a 1wt% carboxymethyl cellulose aqueous solution, water is added (the mass ratio of raw materials to water is 1:0.5), and wet ball milling is performed twice to obtain a coating slurry;

(4) Apply the coating slurry on each surface of the bisque-fired body, dry it, and then sinter it to obtain a ceramic tile; the sintering process is: heating at room temperature at 5°C/min to 1250°C and keeping it warm for 20 minutes.

Example 4: High-strength ceramic brick and its preparation

A high-strength ceramic tile comprises a green body, wherein the green body comprises the following raw materials in parts by weight: 50 parts of clay, 30 parts of quartz, 8 parts of feldspar, 2 parts of talc, 6 parts of bauxite, 4 parts of bentonite and 0.5 parts of modified filler;

The modified filler is prepared from chopped glass fiber, nano silicon nitride, silane coupling agent, fluorocarbon surfactant and solvent in a mass ratio of 12:3:1:3:150; wherein the diameter of the chopped glass fiber is 30 μm and the length is 100 μm; the particle size of the nano silicon nitride is 100 nm; the silane coupling agent is KH-550, the fluorocarbon surfactant is TF-281, and the solvent is anhydrous ethanol;

The preparation method of the modified filler comprises the following steps:

(1) Dissolve KH-550 silane coupling agent in part of anhydrous ethanol, add chopped glass fibers, and disperse under ultrasonic conditions at 600 W for 30 min to obtain a dispersion;

(2) adding nano silicon nitride to the dispersion liquid, and dispersing it ultrasonically at 600 W for 30 min to obtain a mixed liquid;

(3) Dissolve TF-281 fluorocarbon surfactant in the remaining anhydrous ethanol, add it to the mixed solution while stirring, stir at 800 r/min for 60 min, separate and collect the solid, and dry the solid at 80°C to obtain a modified filler.

The method for preparing the above-mentioned high-strength ceramic brick comprises the following steps:

(1) Clay, quartz, feldspar, talc, bauxite, bentonite and modified filler are mixed, water is added (the mass ratio of raw materials to water is 1:0.5), wet ball milling is performed, and spray granulation is performed at 500°C to obtain green body powder;

(2) Pressing the green body powder into a shape, and biscuit-sintering the green body at 650° C. for 30 min to obtain a biscuit;

(3) Sintering the bisque-fired body to obtain ceramic tiles; the sintering process is as follows: heating at 4°C/min to 1200°C at room temperature and keeping the temperature for 30 minutes.

Comparative Example 1 (the difference from Example 1 is that the filler is not modified)

A ceramic tile comprises a body and a strengthening coating coated on the surface of the body, wherein the thickness of the strengthening coating is 400 μm;

The green body includes the following raw materials in parts by weight: 50 parts of clay, 30 parts of quartz, 8 parts of feldspar, 2 parts of talc, 6 parts of bauxite, 4 parts of bentonite and 0.5 parts of filler; the filler is a mixture of chopped glass fiber and nano silicon nitride in a mass ratio of 12:3; the diameter of the chopped glass fiber is 30 μm and the length is 100 μm; the particle size of the nano silicon nitride is 100 nm;

The strengthening coating is prepared from wollastonite, quartz, alumina and a binder solution in a mass ratio of 1:0.5:3:30; wherein the binder solution is a 1wt% carboxymethyl cellulose aqueous solution.

The method for preparing the ceramic tile comprises the following steps:

(1) Clay, quartz, feldspar, talc, bauxite, bentonite and filler are mixed, water is added (the mass ratio of raw materials to water is 1:0.5), wet ball milling is performed, and spray granulation is performed at 500°C to obtain green body powder;

(2) Pressing the green body powder into a shape, and biscuit-sintering the green body at 650° C. for 30 min to obtain a biscuit;

(3) wollastonite, quartz and alumina are mixed, water is added (the mass ratio of raw materials to water is 1:0.5), wet ball milling is performed once, and drying is performed to obtain a coating powder; the coating powder is mixed with a 1wt% carboxymethyl cellulose aqueous solution, water is added (the mass ratio of raw materials to water is 1:0.5), and wet ball milling is performed twice to obtain a coating slurry;

(4) Apply the coating slurry on each surface of the bisque-fired body, dry it, and then sinter it to obtain a ceramic tile; the sintering process is: heating at room temperature at 4°C/min to 1200°C and keeping it at that temperature for 30 minutes.

Comparative Example 2 (the difference from Example 1 is that the filler is only modified by a silane coupling agent)

A ceramic tile comprises a body and a strengthening coating coated on the surface of the body, wherein the thickness of the strengthening coating is 400 μm;

The green body includes the following raw materials in parts by weight: 50 parts of clay, 30 parts of quartz, 8 parts of feldspar, 2 parts of talc, 6 parts of bauxite, 4 parts of bentonite and 0.5 parts of modified filler;

The modified filler is prepared from chopped glass fiber, nano silicon nitride, silane coupling agent and solvent in a mass ratio of 12:3:4:150; wherein the diameter of the chopped glass fiber is 30 μm and the length is 100 μm; the particle size of the nano silicon nitride is 100 nm; the silane coupling agent is KH-550, and the solvent is anhydrous ethanol;

The strengthening coating is prepared from wollastonite, quartz, alumina and a binder solution in a mass ratio of 1:0.5:3:30; wherein the binder solution is a 1wt% carboxymethyl cellulose aqueous solution.

The preparation method of the modified filler comprises the following steps:

(1) Dissolve KH-550 silane coupling agent in part of anhydrous ethanol, add chopped glass fibers, and disperse under ultrasonic conditions at 600 W for 30 min to obtain a dispersion;

(2) Add nano silicon nitride to the dispersion, disperse it ultrasonically at 600 W for 30 min, stir it at 800 r/min for 60 min, separate and collect the solid matter, and dry the solid matter at 80° C. to obtain a modified filler.

The method for preparing the ceramic tile comprises the following steps:

(1) Clay, quartz, feldspar, talc, bauxite, bentonite and modified filler are mixed, water is added (the mass ratio of raw materials to water is 1:0.5), wet ball milling is performed, and spray granulation is performed at 500°C to obtain green body powder;

(2) Pressing the green body powder into a shape, and biscuit-sintering the green body at 650° C. for 30 min to obtain a biscuit;

(3) wollastonite, quartz and alumina are mixed, water is added (the mass ratio of raw materials to water is 1:0.5), wet ball milling is performed once, and drying is performed to obtain a coating powder; the coating powder is mixed with a 1wt% carboxymethyl cellulose aqueous solution, water is added (the mass ratio of raw materials to water is 1:0.5), and wet ball milling is performed twice to obtain a coating slurry;

(4) Apply the coating slurry on each surface of the bisque-fired body, dry it, and then sinter it to obtain a ceramic tile; the sintering process is: heating at room temperature at 4°C/min to 1200°C and keeping it at that temperature for 30 minutes.

Comparative Example 3 (the difference from Example 1 is the lack of chopped glass fibers)

A ceramic tile comprises a body and a strengthening coating coated on the surface of the body, wherein the thickness of the strengthening coating is 400 μm;

The green body includes the following raw materials in parts by weight: 50 parts of clay, 30 parts of quartz, 8 parts of feldspar, 2 parts of talc, 6 parts of bauxite, 4 parts of bentonite and 0.5 parts of modified filler;

The modified filler is prepared from nano silicon nitride, silane coupling agent, fluorocarbon surfactant and solvent in a mass ratio of 15:1:3:150; wherein the particle size of nano silicon nitride is 100 nm; the silane coupling agent is KH-550, the fluorocarbon surfactant is TF-281, and the solvent is anhydrous ethanol;

The strengthening coating is prepared from wollastonite, quartz, alumina and a binder solution in a mass ratio of 1:0.5:3:30; wherein the binder solution is a 1wt% carboxymethyl cellulose aqueous solution.

The preparation method of the modified filler comprises the following steps:

(1) Dissolve KH-550 silane coupling agent in part of anhydrous ethanol, add nano silicon nitride, and disperse under ultrasonic conditions at 600 W for 30 min to obtain a dispersion;

(2) Dissolve TF-281 fluorocarbon surfactant in the remaining anhydrous ethanol, add it to the dispersion while stirring, stir at 800 r/min for 60 min, separate and collect the solid, and dry the solid at 80°C to obtain a modified filler.

The method for preparing the ceramic tile comprises the following steps:

(1) Clay, quartz, feldspar, talc, bauxite, bentonite and modified filler are mixed, water is added (the mass ratio of raw materials to water is 1:0.5), wet ball milling is performed, and spray granulation is performed at 500°C to obtain green body powder;

(2) Pressing the green body powder into a shape, and biscuit-sintering the green body at 650° C. for 30 min to obtain a biscuit;

(3) wollastonite, quartz and alumina are mixed, water is added (the mass ratio of raw materials to water is 1:0.5), wet ball milling is performed once, and drying is performed to obtain a coating powder; the coating powder is mixed with a 1wt% carboxymethyl cellulose aqueous solution, water is added (the mass ratio of raw materials to water is 1:0.5), and wet ball milling is performed twice to obtain a coating slurry;

(4) Apply the coating slurry on each surface of the bisque-fired body, dry it, and then sinter it to obtain a ceramic tile; the sintering process is: heating at room temperature at 4°C/min to 1200°C and keeping it at that temperature for 30 minutes.

Comparative Example 4 (the difference from Example 1 is the lack of nano silicon nitride)

A ceramic tile comprises a body and a strengthening coating coated on the surface of the body, wherein the thickness of the strengthening coating is 400 μm;

The green body includes the following raw materials in parts by weight: 50 parts of clay, 30 parts of quartz, 8 parts of feldspar, 2 parts of talc, 6 parts of bauxite, 4 parts of bentonite and 0.5 parts of modified filler;

The modified filler is prepared from chopped glass fiber, silane coupling agent, fluorocarbon surfactant and solvent in a mass ratio of 15:1:3:150; wherein the diameter of the chopped glass fiber is 30 μm and the length is 100 μm; the silane coupling agent is KH-550, the fluorocarbon surfactant is TF-281, and the solvent is anhydrous ethanol;

The strengthening coating is prepared from wollastonite, quartz, alumina and a binder solution in a mass ratio of 1:0.5:3:30; wherein the binder solution is a 1wt% carboxymethyl cellulose aqueous solution.

The preparation method of the modified filler comprises the following steps:

(1) Dissolve KH-550 silane coupling agent in part of anhydrous ethanol, add chopped glass fibers, and disperse under ultrasonic conditions at 600 W for 30 min to obtain a dispersion;

(2) Dissolve TF-281 fluorocarbon surfactant in the remaining anhydrous ethanol, add it to the dispersion while stirring, stir at 800 r/min for 60 min, separate and collect the solid, and dry the solid at 80°C to obtain a modified filler.

The method for preparing the ceramic tile comprises the following steps:

(1) Clay, quartz, feldspar, talc, bauxite, bentonite and modified filler are mixed, water is added (the mass ratio of raw materials to water is 1:0.5), wet ball milling is performed, and spray granulation is performed at 500°C to obtain green body powder;

(2) Pressing the green body powder into a shape, and biscuit-sintering the green body at 650° C. for 30 min to obtain a biscuit;

(3) wollastonite, quartz and alumina are mixed, water is added (the mass ratio of raw materials to water is 1:0.5), wet ball milling is performed once, and drying is performed to obtain a coating powder; the coating powder is mixed with a 1wt% carboxymethyl cellulose aqueous solution, water is added (the mass ratio of raw materials to water is 1:0.5), and wet ball milling is performed twice to obtain a coating slurry;

(4) Apply the coating slurry on each surface of the bisque-fired body, dry it, and then sinter it to obtain a ceramic tile; the sintering process is: heating at room temperature at 4°C/min to 1200°C and keeping it at that temperature for 30 minutes.

Product performance testing

1. Flexural strength: According to the test method in GB/T3810.4-2016 Ceramic Tile Test Method, the flexural strength of the ceramic tile samples prepared in Examples 1-4 and Comparative Examples 1-4 was tested, and the test results are shown in Table 1.

Table 1

It can be seen from Table 1 that in Examples 1-3 of the present invention, because their green bodies contain modified fillers and their surfaces are coated with a strengthening coating, the flexural strength of the ceramic tiles prepared in Examples 1-3 is significantly improved compared with that in Comparative Examples 1-4; in Example 4, because the surface of the green body is not coated with a strengthening coating, its flexural strength is reduced compared with that in Examples 1-3.

2. Hardness: The ceramic tile samples prepared in Example 1, Example 4 and Comparative Example 1 were subjected to Mohs hardness test, and the test results are shown in Table 2.

Table 2

It can be seen from Table 2 that the ceramic tiles prepared in the embodiments of the present invention also have good hardness.

The preferred embodiments of the present invention are specifically described above, but the invention is not limited to the embodiments. Those skilled in the art may make various equivalent modifications or substitutions without violating the spirit of the invention. These equivalent modifications or substitutions are all included in the scope defined by the claims of this application.

Claims (4)

1. A high strength ceramic tile, wherein the high strength ceramic tile comprises a green body and a strengthening coating;

the strengthening coating is positioned on the surface of the green body, the thermal expansion coefficient of the strengthening coating is smaller than that of the green body, and the strengthening coating is prepared from wollastonite, quartz, aluminum oxide and a binder solution according to the mass ratio of 1 (0.4-0.6), 1-5 and 10-50;

the raw materials of the green body consist of, by mass, 40-60 parts of clay, 25-35 parts of quartz, 6-12 parts of feldspar, 1-3 parts of talcum, 4-8 parts of bauxite, 2-6 parts of bentonite and 0.1-0.8 part of modified filler;

The preparation process of the modified filler comprises the following steps: dissolving a silane coupling agent in a solvent, adding chopped glass fibers, and performing ultrasonic dispersion to obtain a dispersion;

Adding nano silicon nitride into the dispersion liquid, and performing ultrasonic dispersion to obtain a mixed liquid;

dissolving fluorocarbon surfactant in a solvent, adding the solvent into the mixed solution, stirring, separating and collecting solid matters, and drying to obtain the modified filler;

The mass ratio of the chopped glass fiber to the nano silicon nitride to the silane coupling agent to the fluorocarbon surfactant to the solvent is (10-15): 1-5): 0.5-2): 1-5): 150;

the chopped glass fibers have a diameter of 20-40 μm and/or the chopped glass fibers have a length of 50-150 μm;

The particle size of the nano silicon nitride is 50-150nm.

2. A method of making a high strength ceramic tile according to claim 1, comprising the steps of:

mixing clay, quartz, feldspar, talcum, bauxite, bentonite and modified filler, performing wet ball milling, and performing spray granulation to obtain green body powder;

Pressing the blank powder to form, and performing biscuit firing treatment to obtain a biscuit fired blank;

Mixing wollastonite, quartz and alumina, performing wet ball milling for one time, and drying to obtain coating powder;

Mixing the coating powder with a binder solution, and performing secondary wet ball milling to obtain coating slurry;

And coating the coating slurry on the surface of the biscuit, drying and sintering to obtain the high-strength ceramic tile.

3. The method of claim 2, wherein the sintering temperature is 1150-1250 ℃; and/or the temperature rising rate of the sintering is 3-5 ℃/min; and/or sintering for 20-40min.

4. Use of the high strength ceramic tile of claim 1 in the construction field.