CN102951850B - Preparation method of chemical toughened glass product with wearing-resisting film - Google Patents

Abstract

The invention discloses a preparation method of a chemically toughened glass product with a wear-resistant film, which comprises the following steps: (1) coating an oxide film on the surface of a cleaned glass product to obtain a glass product with a wear-resistant coating; (2) ) placing the glass product with wear-resistant coating obtained in step (1) in molten salt, performing ion exchange strengthening at 400-500° C. for 8-18 hours, and then cooling down to room temperature to obtain the chemically tempered glass product. This method uses specially formulated molten salt for ion exchange tempering, which can make the high-hardness wear-resistant coating more densely combined with the surface of the glass product, and can also heal some surface cracks, improve the surface hardness and bending strength of the product, and expand The application fields of chemically tempered glass have been expanded.

Description

A preparation method of chemically tempered glass product with wear-resistant film

technical field

The invention belongs to the technical field of glass surface treatment, and in particular relates to a preparation method of a chemically tempered glass product with a wear-resistant film.

Background technique

The actual use strength of ordinary glass is very low, and it will be cracked or broken when it is slightly bumped and impacted. For brittle materials such as glass, the flexural strength can best reflect its mechanical performance level. The test results show that the average bending strength of ordinary silicate glass is lower than 100Mpa. However, the theoretical flexural strength is at least several orders of magnitude higher, based on calculations based on the strength of the chemical bonds of the glass. The current study believes that this is mainly caused by the surface damage during the production, transportation and storage of glass products and the large number of Griffith microcracks on the surface.

Chemically tempered glass undergoes ion exchange in molten salt, that is, K ⁺ or Na ⁺ with a larger ionic radius in the molten salt exchanges Na ⁺ or Li ⁺ with a smaller radius on the glass surface to produce a "crowding effect" on the surface. Form a surface compressive stress layer, thereby reducing the influence of surface cracks, and increasing the strength of glass products by 3 to 6 times, which is higher than the 1 to 2 times improvement of physical tempering. However, in use, since the compressive stress layer of chemically tempered glass is thin, usually less than 50 μm, its surface stress layer is easily damaged by friction or impact through scratches, resulting in a significant decrease in the strength of chemically tempered glass.

In order to obtain chemically tempered glass products with strong scratch resistance, some methods are currently proposed: the first method is to use glass varieties with faster ion exchange speed and matching molten salts (such as: lithium aluminum silicate glass and sodium nitrate molten salt ), a shorter time of ion exchange can obtain products with a stress layer depth exceeding 200 μm, which avoids the 40-50 μm depth that is usually easily damaged on the glass surface. The Chinese patent application with the publication number CN1886348B discloses a tempered glass containing lithium oxide-alumina-silicon oxide. The ion exchange depth of more than 150 μm can be obtained by performing ion exchange in sodium nitrate molten salt for more than 8 hours. This is due to the fact that lithium ions have a radius of 60 pm, sodium ions have a radius of 95 pm, and potassium ions have a radius of 133 pm. The radius of sodium ions is smaller than that of potassium ions, and the energy required for sodium ions to replace lithium ions from the glass is less than the energy required for potassium ions to replace sodium ions, so thicker glass can be obtained faster at lower temperatures Tempered layer. But compared to soda-lime glass, which is most commonly used for chemical tempering, this method requires the use of expensive lithium glass, which limits the scope of application.

The second method is to cover the protective film on the surface of the chemically tempered glass. This method is widely used in the application of ordinary glass, and the high-hardness film covered can not only improve the wear resistance, but also due to the gravitational impact on the surface of the glass product. The Fez microcracks were partially repaired, and the strength of the glass was also improved and the dispersion of strength was reduced. However, since chemically tempered glass products cannot be exposed to the high temperature above 300°C required for the curing of the wear-resistant film for a long time, the types, properties and preparation methods of the wear-resistant film are limited.

Muneo Watanabe et al. disclosed another method for preparing scratch-resistant glass products in 1975 (US Patent: 4021218). Different from the above-mentioned second method, this method first coats the wear-resistant oxide on the surface of soda-lime glass products through a certain film preparation process, and then applies a high concentration of KCl-KNO ₃ or K ₂ SO ₄ -KNO ₃ The solution is sprayed on the surface of the glass product and preheated at about 130°C, and then the glass product is placed at a temperature slightly lower than the softening point of the glass for ion exchange enhancement. After cooling and cleaning, the surface compressive stress of the final product can reach 110Mpa , The ion exchange depth can reach about 16μm. However, when using this method, the thickness of the film is limited, and the ion exchange effect is very poor after exceeding 15nm, the thickness of the tempered layer decreases rapidly, and the strength of the glass after chemical tempering is limited.

Contents of the invention

The invention provides a method for preparing a chemically tempered glass product with a wear-resistant film. The chemically tempered glass product prepared by the preparation method has high surface hardness and bending strength, a large surface ion exchange depth and excellent wear resistance.

A method for preparing a chemically tempered glass product with a wear-resistant film, comprising the steps of:

(1) Coating an oxide film on the surface of the glass product;

(2) Place the glass product coated with an oxide film on the surface obtained in step (1) in molten metal salt, carry out ion exchange strengthening at 400-500° C. for 8-18 hours, cool down, take it out and clean it, and obtain the glass product with Chemically tempered glass products with wear-resistant film;

The weight percent composition of molten metal salt described in step (2) is as follows:

The invention first prepares wear-resistant coating on the surface of ordinary glass products, and then uses specially prepared molten salt for ion exchange tempering, which can make the high-hardness wear-resistant coating more compactly combined with the surface of glass products, and can also heal part of the surface Cracks improve the dispersion of product strength. At the same time, the chemical tempering of coated glass products in specially designed molten salt can make the driving force of ion exchange greater. Even when the thickness of the wear-resistant coating reaches 1 μm, a relatively large ion exchange depth can still be obtained. Therefore, the obtained chemical Tempered glass products also have high surface hardness and bending strength, and excellent wear resistance.

In the molten salt, potassium nitrate and sodium nitrate are used as ion sources for ion exchange. Potassium carbonate and sodium carbonate are melted in the molten salt, and the carbonate ion forms an infusible substance with high-priced impurity ions that affect the ion exchange rate and is α-oxidized. Aluminum and diatomaceous earth are adsorbed, sodium hydroxide and potassium hydroxide cut off the silicon-oxygen bond on the surface to form more ion exchange channels, and accelerate the entire ion exchange process.

Preferably, the glass product is lithium-containing glass, which is strengthened by lithium-sodium ion exchange with molten salt;

The weight percentage composition of described molten metal salt is as follows:

The lithium-containing glass is further preferably lithium-aluminosilicate glass.

At this time, the glass product contains lithium ions, and the main cationic component in the molten salt is sodium ions. The difference between the ionic radii of sodium ions and lithium ions is appropriate, and the "crowding effect" can be generated by ion exchange. "The surface stress layer is formed, and the energy required is small, and greater surface stress can be obtained at a lower temperature.

As another preference, the glass product is sodium-containing glass, which is strengthened by sodium-potassium ion exchange with molten salt;

The weight percentage composition of described molten metal salt is as follows:

The sodium-containing glass is further preferably soda-lime glass or soda-aluminosilicate glass.

At this time, the glass product contains sodium ions, and the main cationic component in the molten salt is potassium ions. The difference in ionic radius between potassium ions and sodium ions is appropriate, and "crowding" can also be generated by ion exchange. effect" to form a surface stress layer.

In the present invention, the method for coating the surface of the glass product with an oxide film includes chemical or physical vapor deposition, magnetron sputtering, molecular layer deposition, spray pyrolysis, pulse laser deposition or sol-gel method. Preferably, the method of coating the oxide film on the surface of the glass product is a sol-gel method, and a uniform and crack-free oxide film can be obtained by using the sol-gel method, and the preparation conditions of this method are mild, the source of raw materials is wide, and the cost is low. , Suitable for surface coating of glass products of various shapes.

The thickness of the oxide thin film coated on the surface of the glass product is ≤1 μm, and if the thickness is too large, the efficiency of ion exchange will be affected.

As preferably, the concrete steps of described sol-gel method are as follows:

(a) Dissolving the oxide precursor with a solvent, adding an auxiliary agent, performing a hydrolysis polymerization reaction, and obtaining an oxide sol after the reaction is completed;

(b) coating the oxide sol obtained in step (a) on the surface of the glass product, then drying at a temperature of 50-200° C. for 0.5-2 hours, and performing heat treatment at a temperature lower than the softening point of the glass for 2-4 hours, Obtain a glass product coated with an oxide film on the surface;

The surface of the glass product is first cleaned using a method well known to those skilled in the art;

In step (b), dilute nitric acid may be added to the oxide sol to stabilize its viscosity before coating.

As a preference, in step (a), the solvent is water and/or ethanol.

In step (a), the oxide precursor is an inorganic compound capable of generating oxides through hydrolytic polymerization, and the oxides are oxidations of transition metal elements, III, IV and/or V main group elements material, the obtained coating can be a single-element oxide film or a multi-element oxide film, and the oxide sol is further preferably ZrO ₂ , SnO ₂ , Al ₂ O ₃ , Cr ₂ O ₃ , SiO ₂ and V ₂ O At least one of the sols of ₅ , the coating formed by these oxide sols has good wear resistance and good light transmission performance.

Preferably, in step (a), the auxiliary agent is ammonia water, hydrogen peroxide or propylene oxide, which can participate in the hydrolysis polymerization reaction of the oxide precursor to promote the progress of the hydrolysis polymerization reaction.

In step (a), the temperature of the hydrolysis polymerization reaction is room temperature.

In step (b), the coating method is spray method, roll coating method, pulling method or spin coating method.

Compared with the prior art, the beneficial effects of the present invention are reflected in:

(1) The surface of the glass product prepared by the preparation method of the present invention has a layer of scratch-resistant film, which can increase the hardness of the glass surface to more than 18Gpa, and improves the resistance to frictional damage and scratches of the product in daily use;

(2) A compressive stress layer (ion exchange depth) of more than 30 μm can be obtained on the surface of the prepared glass product with a soda-calcium matrix, and the surface compressive stress is greater than 300 Mpa, and the dispersion of strength is also improved. This expands the application fields of chemically tempered glass products and prolongs the service life of such products, especially when they are used as touch screen panels and glass windshields.

Description of drawings

Fig. 1 is the XRD spectrum of the obtained film of embodiment 1 of the present invention;

Fig. 2 is the surface nano-indentation hardness of the glass product obtained in Example 1 of the present invention;

Fig. 3 is the visible light transmittance of the glass product obtained in Example 1 of the present invention.

Detailed ways

The present invention is further specifically described below through examples. (All raw materials are commercially available, and are chemically pure or analytically pure grades unless otherwise specified)

Embodiment 1: preparation surface is plated _ZrO wear-resistant film chemically toughened flat soda-lime glass

Zirconium oxychloride, deionized water, ethanol, and hydrogen peroxide are used as raw materials, wherein the volume ratio of deionized water to ethanol is 1:4, and zirconium oxychloride is 2% of the total mass of deionized water+ethanol based on the mass of zirconia, The molar ratio of hydrogen peroxide to zirconium oxychloride is 4:1. At room temperature, each substance was added sequentially for about 4 hours with thorough stirring, and a colorless transparent sol was formed. After aging for 6 hours, the viscosity of the sol reaches the coating requirement, and the viscosity of the sol is stabilized by dripping 0.5% dilute nitric acid in an amount of 0.5ml per 100ml of sol. After the sol was coated on the cleaned flat glass surface by the pulling method, the product was dried in an oven at 60°C for 30 minutes, then placed in a muffle furnace at 550°C for 2 hours in an air atmosphere, and then transferred to potassium nitrate at 450°C. Ion exchange was carried out for 15 hours in molten salt (KNO ₃ 95.5%, K ₂ CO ₃ 2%, α-Al ₂ O ₃ 1%, diatomaceous earth 1%, KOH 0.5%). After the product is taken out, it can be obtained by cooling and washing. The nano-indentation hardness of the surface was tested by a nano-indentation hardness tester, and the measured result exceeded 18Gpa. At the same time, the three-point bending strength test was carried out on the double-sided coated flat glass sample, and the average reached more than 380Mpa. At this time, the ion exchange depth More than 15μm, the visible light transmittance is greater than 80%. The XRD pattern of the surface film is shown in Figure 1, the nanoindentation hardness of the surface film is shown in Figure 2, and the visible light transmittance of the sample is shown in Figure 3.

Embodiment 2: preparation surface is plated SnO _Wear -resistant film chemically toughened flat soda-lime glass

Use tin chloride, deionized water, ethanol, and hydrogen peroxide as raw materials, wherein the volume ratio of deionized water to ethanol is 1:4, tin chloride is 5% of the total mass of water+ethanol based on the mass of tin oxide, and hydrogen peroxide is added to chlorinate The amount of tin molar ratio 4. At room temperature, each substance was added sequentially for about 4 hours with thorough stirring, and a colorless transparent sol was formed. After aging for 6 hours, the viscosity of the sol reaches the coating requirement, and the viscosity of the sol is stabilized by dripping 0.5% dilute nitric acid in an amount of 0.5ml per 100ml of sol. After the sol was coated on the cleaned flat glass surface by the pulling method, the product was dried in an oven at 60°C for 30 minutes, then placed in a muffle furnace at 550°C for 2 hours in an air atmosphere, and then transferred to potassium nitrate at 450°C. Ion exchange was carried out for 13 hours in molten salt (KNO ₃ 95.5%, K ₂ CO ₃ 2%, α-Al ₂ O ₃ 1%, diatomaceous earth 1%, KOH 0.5%). After the product is taken out, it can be obtained by cooling and washing. The nano-indentation hardness of the surface film was tested by a nano-indentation hardness tester, and the measured result exceeded 17Gpa. At the same time, the three-point bending strength test was carried out on the double-sided coated flat glass sample, and the average reached more than 380Mpa. At this time, the ion exchange The depth exceeds 17 μm, and the visible light transmittance is greater than 85%.

Example 3: Preparation of surface-plated _Al2O3 wear-resistant film _chemically toughened flat soda-lime glass

Aluminum chloride, deionized water, ethanol, and propylene oxide are used as raw materials, wherein the volume ratio of deionized water to ethanol is 1:4, aluminum chloride is 2% of the total mass of water+ethanol based on the mass of alumina, and epoxy Propane is added in an amount of 6 molar ratios to aluminum chloride. At room temperature, the substances were added sequentially for about 7 hours with thorough stirring, and a colorless transparent sol was formed. After aging for 15 hours, the viscosity of the sol reaches the coating requirement, and the viscosity of the sol is stabilized by dropping 0.5% dilute nitric acid in an amount of 0.5 ml per 100 ml of sol. After the sol was coated on the cleaned flat glass surface by the pulling method, the product was dried in an oven at 60°C for 30 minutes, then placed in a muffle furnace at 550°C for 2 hours in an air atmosphere, and then transferred to potassium nitrate at 450°C. Ion exchange was carried out for 13 hours in molten salt (KNO ₃ 95.5%, K ₂ CO ₃ 2%, α-Al ₂ O ₃ 1%, diatomaceous earth 1%, KOH 0.5%). After the product is taken out, it can be obtained by cooling and washing. The nano-indentation hardness of the surface film was tested by a nano-indentation hardness tester, and the measured result exceeded 19Gpa. At the same time, the three-point bending strength test was carried out on the double-sided coated flat glass sample, and the average reached more than 400Mpa. At this time, the ion exchange The depth exceeds 18 μm, and the visible light transmittance is greater than 85%.

Example 4: Preparation of surface-coated ZrO ₂ -SiO ₂ wear-resistant film chemically toughened flat lithium-aluminosilicate glass

Zirconium oxychloride, ethyl orthosilicate, deionized water, ethanol, and ammonia water are used as raw materials, wherein the volume ratio of deionized water to ethanol is 1:7, and the molar ratio of zirconium oxychloride to ethyl orthosilicate is 1: 1. The total amount of the two is 2% of the total mass of water+ethanol according to the mass of the oxide, and the concentrated ammonia water is diluted 10 times for later use. The amount added is about 3 times the molar amount of zirconium oxychloride in terms of _NH4 ⁺ . At room temperature, add ethanol, tetraethyl orthosilicate, deionized water, and zirconium oxychloride in sequence, stir thoroughly, then slowly drop diluted ammonia water, and after about 2 hours of uninterrupted stirring, ZrO ₂ -SiO ₂ Colorless transparent sol. After aging for 5 years, the viscosity of the sol reaches the coating requirement, and the viscosity of the sol is stabilized by dropping 0.5% dilute nitric acid in an amount of 1ml per 100ml of sol. After the sol is coated on the cleaned flat glass surface by the pulling method, the product is dried in an oven at 60°C for 30 minutes, then placed in a muffle furnace at 550°C for 2 hours in an air atmosphere, and then transferred to sodium nitrate at 400°C Ion exchange was carried out for 10 h in molten salt (NaNO ₃ 95.5%, Na ₂ CO ₃ 2%, α-Al ₂ O ₃ 1%, diatomaceous earth 1%, NaOH 0.5%). After the product is taken out, it can be obtained by cooling and washing. The nano-indentation hardness of the surface was tested by a nano-indentation hardness tester, and the measured result exceeded 18Gpa. At the same time, the three-point bending strength test was carried out on the double-sided coated flat glass sample, and the average reached more than 580Mpa. At this time, the ion exchange depth More than 45μm, the visible light transmittance is greater than 85%.

Example 5: Preparation of surface-coated ZrO ₂ -SnO ₂ -Al ₂ O ₃ ternary wear-resistant film chemically toughened flat ultra-thin sodium aluminum silicate glass

Zirconium oxychloride, aluminum chloride, tin tetrachloride, deionized water, ethanol, PEG1000, and ammonia water are used as raw materials, wherein the volume ratio of deionized water to ethanol is 1:1, zirconium oxychloride: aluminum chloride: four The molar ratio of tin chloride is 2:1:2, the total amount of the three is 1 ^% of the total mass of water+ethanol according to _the mass of the oxide, and the concentrated ammonia water is diluted 10 times for later use, and the amount added is about The molar weight of zirconium oxychloride is 5-15 times, and 0.5 wt% of the solid content is added with PEG1000. Add zirconium oxychloride, aluminum chloride, tin tetrachloride, deionized water, ethanol, and PEG1000 in sequence, stir thoroughly, dissolve to obtain a mixed solution, and then slowly drop in diluted ammonia water, and stir continuously for about 2 hours , forming ZrO ₂ -SnO ₂ -Al ₂ O ₃ light blue transparent sol. After aging for 15 hours, the viscosity of the sol reaches the coating requirement, and the viscosity of the sol is stabilized by dropping 0.5% dilute nitric acid in an amount of 1ml per 100ml of sol. After the sol was coated on the surface of the cleaned soda-aluminosilicate glass by the pulling method, the product was dried in an oven at 60°C for 30 minutes, then heat-treated in a muffle furnace at 550°C for 2 hours in an air atmosphere, and then transferred to a 450°C oven. Ion exchange was carried out in potassium nitrate molten salt (KNO ₃ 95.5%, K ₂ CO ₃ 2%, α-Al ₂ O ₃ 1%, diatomaceous earth 1%, KOH 0.5%) for 15 hours. After the product is taken out, it can be obtained by cooling and washing. The nano-indentation hardness of its surface was tested by a nano-indentation hardness tester, and the measured result exceeded 19Gpa. At the same time, the three-point bending strength test was carried out on the double-sided coated flat glass sample, and the average reached more than 420Mpa. At this time, the ion exchange depth More than 25μm, the visible light transmittance is greater than 85%.

The above content is a further detailed description of the present invention in combination with specific preferred embodiments, and it cannot be considered that the specific implementation of the present invention is limited to these descriptions. For those skilled in the relevant technical fields of the present invention, without departing from the concept of the present invention, some simple deduction or replacement can also be made, which should be regarded as the protection scope of the present invention.

Claims (6)

1. there is a preparation method for the chemically toughened glass goods of wear-resistance thin film, it is characterized in that, comprise the steps:

(1) sull is plated at glass article surface;

(2) on plated surface step (1) obtained, the glasswork of sull is placed in metal fused salt, after carrying out ion-exchange strengthening 8-18h at 400-500 DEG C, cooling, takes out cleaning, obtains the described chemically toughened glass goods with wear-resistance thin film;

The weight percent of the metal fused salt described in step (2) is composed as follows:

Described glass article surface plates thickness≤1 μm of sull;

The method that described glass article surface plates sull is sol-gel method;

The step of described sol-gel method is as follows:

A oxide precursor dissolves with solvent by (), add auxiliary agent, and be hydrolyzed polyreaction, after having reacted, obtains oxide sol;

B oxide sol that step (a) obtains by () is coated in glass article surface, then dry 0.5-2 hour at 50 ~ 200 DEG C of temperature, and 2-4 hour is heat-treated at lower than glass softening point temperature, obtain the glasswork of sull on plated surface.

2. the preparation method with the chemically toughened glass goods of wear-resistance thin film according to claim 1, is characterized in that, described glasswork, for containing lithium glass, carries out lithium sodium ion exchange with fused salt and strengthens;

The weight percent of described metal fused salt is composed as follows:

3. the preparation method with the chemically toughened glass goods of wear-resistance thin film according to claim 1, is characterized in that, described glasswork for containing soda glass, carries out sodium potassium ion with fused salt and exchanges and strengthen;

The weight percent of described metal fused salt is composed as follows:

4. the preparation method with the chemically toughened glass goods of wear-resistance thin film according to claim 1, is characterized in that, in step (a), described solvent is water and/or ethanol.

5. the preparation method with the chemically toughened glass goods of wear-resistance thin film according to claim 1, is characterized in that, in step (a), described oxide sol is ZrO ₂, SnO ₂, Al ₂o ₃, Cr ₂o ₃, SiO ₂and V ₂o ₅colloidal sol at least one.

6. the preparation method with the chemically toughened glass goods of wear-resistance thin film according to claim 1, is characterized in that, in step (a), described auxiliary agent is ammoniacal liquor, hydrogen peroxide or propylene oxide.