CN108675650A

CN108675650A - A kind of preparation method of flame resistant glass

Info

Publication number: CN108675650A
Application number: CN201810553191.2A
Authority: CN
Inventors: 田永刚; 陈玉平; 陈乃雄
Original assignee: Fujian Xinfuxing Glass Co Ltd
Current assignee: Fujian Xinfuxing Glass Co Ltd
Priority date: 2018-05-31
Filing date: 2018-05-31
Publication date: 2018-10-19
Anticipated expiration: 2038-05-31
Also published as: CN108675650B

Abstract

The invention discloses a kind of preparation methods of flame resistant glass, the method of the present invention includes to carrying out tempering processing again after using fire-resistant fluid to react glass surface into line replacement, the flame resistant glass high temperature resistance prepared using the method for the present invention is good, fire resistance is high, shock resistance is strong, it is safe to use with excellent mechanical performance, provide effective time guarantee for mankind's escape, fire extinguishing under the environment that catches fire；Moreover, the method for the present invention is easy to operate, preparation process condition is mild, reduces the production cost of flame resistant glass.

Description

Preparation method of fireproof glass

Technical Field

The invention relates to a preparation method of glass, in particular to a preparation method of fireproof glass, and belongs to the field of fireproof glass production.

Background

The fireproof glass is a special glass capable of keeping the integrity in a specified fire resistance test, has the function of controlling the spread of fire or isolating smoke during fire prevention, is a measure type fireproof material, and the fire prevention effect is evaluated by the fire resistance. It is a special glass which is processed and treated by a special process and can keep the integrity and heat insulation performance in a specified fire resistance test. The original piece of the fireproof glass can be made of float plane glass, toughened glass, composite fireproof glass or single piece of fireproof glass.

The fireproof glass mainly comprises five kinds, namely interlayer composite fireproof glass, wired fireproof glass, special fireproof glass, hollow fireproof glass and high-strength single-layer cesium-potassium fireproof glass; the method is divided into three categories according to product categories, and the three categories are as follows: a type: meanwhile, the fireproof glass meets the requirements of fire resistance integrity and fire resistance and heat insulation. Comprises composite fire-proof glass and pouring fire-proof glass. The glass has the advantages of light transmission, fire resistance (smoke insulation, fire insulation and heat radiation shielding), sound insulation and impact resistance, and is suitable for steel-wood fireproof doors, windows, overhead walls, partition walls, lighting roofs, smoke-blocking vertical walls, perspective floors and other building components needing transparency and fire resistance for architectural decoration; b type: meanwhile, the fireproof glass meets the requirements on fire resistance integrity and heat radiation intensity. Most of the fireproof glass is composite fireproof glass which has the characteristics of light transmission, fire prevention and smoke isolation; class C: a single sheet of fire-resistant glass that only meets the fire integrity requirements. The glass has the characteristics of light transmission, fire prevention, smoke isolation, high strength and the like. The glass is suitable for fireproof glass partition walls, fireproof windows, outdoor curtain walls and the like without heat insulation requirements. The fireproof glass is divided into composite fireproof glass (grouting type and composite type, the grouting fireproof glass has good heat insulation performance, and the composite fireproof glass has good fireproof performance) and single fireproof glass according to the structure. Wherein, the composite fireproof glass is compounded by two or more layers of glass original sheets and one or more water-soluble inorganic fireproof glue interlayers; and the single sheet of fire-resistant glass is a fire-resistant glass of single-layer glass construction. The fire-resistant heat-insulating material can keep the fire-resistant integrity and block open fire and toxic and harmful gases on the fire-facing side within a certain time, but has no heat-insulating and heat-insulating effects.

The high-strength single-layer cesium-potassium fireproof glass has the advantages of explosion-proof performance, easiness in installation, transparent function under the action of ultraviolet rays and flame and the like, is simple to manufacture, and can be used after being treated only by spraying or soaking fireproof liquid on the surface of the glass and then carrying out heat treatment. It follows that the properties of the fire-protecting liquid determine the properties of the fire-protecting glass.

The research on the prior single-sheet fireproof glass is numerous, for example, the invention patent application with the application number of 201610899763.3 discloses a glass fireproof liquid and the application thereof, wherein the glass fireproof liquid comprises the following components in parts by weight: 25-55 parts of water; 30-65 parts of potassium salt; 0.02-2 parts of cesium nitrate; 0.1-2 parts of a coupling agent; 0.2-8 parts of coating liquid tackifier; 3-10 parts of a stripping agent; 0.2-2 parts of cationic surfactant. Although the fireproof glass prepared by the fireproof liquid after treatment has good anti-disengagement, anti-aging and fireproof performances, the glass is soaked in the fireproof liquid, so that requirements on production places and equipment are provided, the manufacturing cost of a processing plant is increased, and the surface stress value of the produced product is less than 200 MPa. When the surface stress value of the glass is lower than 200MPa, the glass is easy to crack in the process of fire, particularly in the initial stage of fire, because the glass cracks in the first 15 minutes under the condition of high temperature, the temperature of the fireproof glass rises after the glass is subjected to high-temperature combustion for 15-20 minutes, the glass slowly begins to anneal until being softened, and the glass is difficult to crack. For another example, the invention patent application with the application number of 02117908.5 discloses a preparation method of single-piece toughened fireproof glass, which comprises the steps of spraying a potassium salt solution on the surface of finely ground glass, drying, performing chemical toughening in a heat treatment furnace, performing physical toughening and attaching a PET low-radiation film, wherein the potassium salt solution serving as a fireproof liquid is prepared from the following components in percentage by weight: potassium salt: 30-65%, sodium salt: 0.5-4%, potassium fluoride: 2.5-10%, coating liquid tackifier: 0.2-8%, stripping agent: 2-20%, anionic surfactant: 0.2-2%, water: 25-55%. Although the fireproof performance of the glass is improved to a certain extent, the fireproof liquid prepared by the method has low adhesive force, so that the compatibility between the fireproof liquid layer and the glass is poor, the problems of poor anti-disengagement and anti-aging performance of the glass often occur in the long-time use process to influence the fireproof performance, along with the continuous development of the building industry, the utilization rate of the fireproof glass is higher and higher, and the fireproof liquid is required to ensure that the glass still has good fireproof performance under the condition of long-time use.

Disclosure of Invention

The invention aims to provide a preparation method of fireproof glass aiming at the technical defects in the preparation process of the existing single fireproof glass, the fireproof glass prepared by the method has the advantages of low cost, convenient preparation, low requirement on environment, no increase of the cost of a manufacturing factory and simple construction, the prepared fireproof glass can be directly used on the outer wall of a building, the visible light transmittance is high, the fire resistance integrity period is long, the weight is light, and the aging and cracking phenomena are avoided; the thickness is small, the influence of the self weight of the glass on the window is reduced, and the service life of the window is prolonged; meanwhile, the requirements on the thickness and the type of the window profile are reduced, the installation is convenient, and a large amount of material manufacturing, processing and construction costs are saved; the composite material can be subjected to deep processing treatment, has strong composite processability, and has extremely small particles and extremely small damage to human bodies when being impacted and broken through products (such as hollow glass and coated glass) compounded with other materials; the thermal expansion coefficient is small, and the high-temperature flame-retardant coating can not be cracked or deformed generally under strong flame; the fire resistance time is long when a fire disaster occurs, and the glass is softened; not only has the fireproof function, but also has the functions of energy conservation, radiation protection, safety and the like.

In order to achieve the purpose of the invention, the invention provides a preparation method of fireproof glass, which comprises the steps of carrying out replacement treatment on the surface of the glass and then carrying out tempering treatment on the glass.

Wherein, the replacement treatment is to spray glass fireproof liquid on the surface of the glass, and the ion exchange reaction is carried out between the surface of the glass and the fireproof liquid.

In particular, the fire-proof liquid used for the replacement treatment is prepared by the following steps in sequence:

1) preparing the following raw materials in parts by weight

2) Sequentially pouring raw materials of potassium nitrate, cesium nitrate, seven eight Swiss, methacrylic acid, acetone and table salt into the reactor

Stirring in water, and mixing;

3) and standing the uniformly stirred materials to obtain the material.

Wherein the raw materials in the step 1) are prepared from the following raw materials in parts by weight:

wherein,

the methacrylic acid has the effects of promoting ion exchange, fusing various solutions, stabilizing polymerization, improving the adhesive force of the fireproof liquid on the surface of the glass and thickening, is an intermediate of the fireproof solution, and uniformly disperses potassium nitrate and cesium nitrate; seventy-eight Switzerland (also called photoinitiator 1173, HMPP; photoinitiator 1173) has the functions of improving the speed of chain polymerization, crosslinking and grafting reaction/fusion among components in a solution, stabilizing the storage safety of the fireproof liquid, initiating and accelerating the rapid ion exchange reaction between cesium ions and potassium ions in the fireproof composition and the surface of glass, and improving the ion replacement activity of the fireproof liquid and the glass; the acetone has the functions of organic synthesis raw materials, diluents and extractants for improving the dissolution of various materials; cesium nitrate is a strong oxidant, soluble in water, acetone, slightly soluble in ethanol. Has strong oxidizing property. The cesium ions are contacted with or mixed with organic matters, reducing agents, inflammable matters such as sulfur, phosphorus and the like to cause the danger of combustion and explosion, are used for preparing catalysts and characteristic glass, and are subjected to ion exchange reaction with the surface of the glass, and the cesium ions with large radius replace the sodium ions with small radius), so that the cesium ions are permeated into the surface of the glass, the stress value of the surface of the glass is enhanced, and the impact strength of the glass is improved; the potassium nitrate has strong oxidizing property, is contacted with organic matters, is easy to generate redox reaction, is easy to dissolve in water, is beneficial to ion exchange between fire-proof liquid and glass (potassium ions with large radius replace sodium ions and magnesium ions with small radius), and enhances the surface stress value of the glass (the conventional toughened glass has surface stress of about 90-120MPa, the chemical replacement reaction of the fire-proof composition and the surface of the glass is carried out, then the glass is treated by steel technology, and the surface stress can be effectively increased to be more than or equal to 200 MPa); the sodium chloride has the functions of solving the problems that the endothermic reaction speed is reduced and the solution becomes thick when various solutions are mixed and dissolved, and ions with large radius are replaced by ions with small radius in the glass; under the action of the materials, potassium ions with large ionic radius are replaced and exchanged with sodium ions with small ionic radius in the float glass, the chemical composition of the surface of the glass is changed, the expansion coefficient of the glass is reduced, the strength of the glass is improved, an ion exchange layer with the diameter of 20-100 mu m is formed on the surface layer of the glass, microcracks on the surface of the glass are closed, the residual stress of the glass can be fully eliminated through heat treatment, and the surface strength of the glass is improved. The fire-proof liquid and the glass surface generate ion exchange reaction to replace metal sodium on the glass surface, thereby reducing the expansion coefficient of the glass and improving the compressive stress on the glass surface. The fireproof liquid is sprayed on the surface of the glass, the adhesive force between the fireproof liquid and the surface of the glass is strong, a liquid film with strong adhesive force is formed and is uniformly distributed on the surface of the glass, so that cesium ions and potassium ions in the fireproof liquid are uniformly distributed on the surface of the glass, the uniform ion exchange is promoted, the defect of non-uniform ion exchange on the surface of the glass is avoided, and the stress value of the glass is improved.

Particularly, the stirring and mixing time in the step 2) is 1.5-2 h; the stirring speed is 60-120rpm, preferably 60 rpm; the standing treatment time in the step 3) is more than or equal to 48 hours, preferably 48 to 60 hours; the standing temperature is 20-25 ℃.

Wherein the spraying amount of the fireproof liquid is 10-15g/m²Preferably 12g/m². I.e. 10-15g, preferably 12g, of fire-proof liquid is sprayed on the surface of the glass per square meter.

Particularly, the replacement treatment temperature is more than or equal to 5 ℃; the replacement treatment time is more than or equal to 30 min.

Particularly, when the replacement treatment temperature is 5-15 ℃, the replacement treatment time is 30-60min, preferably 45-60 min; when the replacement treatment temperature is more than or equal to 15 ℃, the replacement treatment time is 30-45 min.

Particularly, the method also comprises cleaning and drying treatment, namely washing the glass after the replacement treatment by using clean water to remove the fire-proof liquid on the surface of the glass, and then drying the cleaned glass to remove the water on the surface of the glass.

Wherein the toughening reaction comprises the following steps of:

A) preheating the glass after replacement treatment by adopting a hot air convection heating mode

B) Heat treating the preheated glass

C) And cooling the heat-treated glass in an air cooling mode to obtain the glass.

In particular, the preheating treatment temperature in the step A) is 420-500 ℃, preferably 430-475 ℃; the preheating treatment time is more than or equal to 190s, preferably 190-615 s.

Wherein, when 6mm float glass is used for the replacement treatment, the preheating treatment temperature is (475 +/-5) DEG C, preferably 475 ℃; the preheating treatment time is 190-200s, preferably 190 s; when 8mm float glass is used for the displacement treatment, the preheating treatment temperature is (475 +/-5) ℃, preferably 475 ℃; the preheating treatment time is 250s-270s, preferably 260 s; when 10mm float glass is used for the displacement treatment, the preheating treatment temperature is (450 +/-5) DEG C, and preferably 450 ℃; the preheating treatment time is 330s-350s, preferably 347.5 s; when 12mm float glass is used for the displacement treatment, the preheating treatment temperature is (450 +/-5) DEG C, and preferably 450 ℃; the preheating treatment time is 350-365s, preferably 355 s; when 15mm float glass is used for the displacement treatment, the preheating treatment temperature is 430 +/-5 ℃, preferably 430 ℃; the preheating treatment time is 430-450s, preferably 440 s; when 19mm float glass is used for the displacement treatment, the preheating treatment temperature is 430 +/-5 ℃, preferably 430 ℃; the preheating treatment time is 600-625s, preferably 615 s.

In particular, the hot air convection heating method is a method of heating glass by applying hot air to both upper and lower surfaces of the glass after the exchange treatment.

Wherein the hot air pressure intensity of the upper surface of the glass in the preheating treatment process is 1.2-3.6bar within the interval of 1-70% of convection heating time (namely preheating treatment time); the pressure intensity of hot air on the upper surface of the glass is 0-1.8bar in 70-80% of convection heating time interval; the pressure intensity of the hot air on the upper surface of the glass is 0 in 80-100% of the convection heating time interval.

Wherein, the hot air pressure intensity of the lower surface of the glass in the preheating treatment process is 0.6-1.8bar in the interval of 1-70% of convection heating time (namely preheating treatment time) on the upper surface; the pressure intensity of hot air on the upper surface of the glass is 0-1.8bar in 70-80% of convection heating time interval; the pressure intensity of the hot air on the upper surface of the glass is 0 in 80-100% of the convection heating time interval.

Particularly, when 6-10mm float glass is used for the displacement treatment, the intensity of hot air pressure on the upper surface of the glass is (3.6 +/-0.1) bar, preferably 3.6bar, in the interval of 1-50% of convection heating time (namely preheating treatment time); the pressure intensity of hot air at the upper part of the glass is uniformly reduced from (3.6 +/-0.1) bar to (1.8 +/-0.1) bar, preferably from 3.6bar to 1.8bar in a 50-70% convection heating time interval; the pressure intensity of the hot air on the upper surface of the glass is uniformly reduced from (1.8 +/-0.1) bar to 0, preferably from 1.8bar to 0 in 70-80% of convection heating time interval; the pressure intensity of hot air on the upper surface of the glass in 80-100% of convection heating time interval is 0; the hot air pressure intensity of the lower surface of the glass is (1.8 +/-0.1) bar, preferably 1.8bar in the interval of 1-70% of convection heating time (namely preheating treatment time); the pressure intensity of the hot air on the lower surface of the glass is uniformly reduced from (1.8 +/-0.1) bar to 0, preferably from 1.8bar to 0 in 70-80% of convection heating time interval; the pressure intensity of the hot air on the upper surface of the glass in 80-100% of the convection heating time interval is 0.

Particularly, when 12-19mm float glass is used for the displacement treatment, the intensity of hot air pressure on the upper surface of the glass is uniformly reduced from (1.8 +/-0.1) bar to (1.2 +/-0.1) bar, preferably from 1.8bar to 1.2bar, in the interval of 1-50% of convection heating time (namely preheating treatment time); the pressure intensity (1.2 +/-0.1) bar of hot air at the upper part of the glass in a 50-70% convection heating time interval, preferably 1.2 bar; the pressure intensity of the hot air on the upper surface of the glass is uniformly reduced from (1.2 +/-0.1) bar to 0, preferably from 1.2bar to 0 in 70-80% of convection heating time interval; the pressure intensity of hot air on the upper surface of the glass in 80-100% of convection heating time interval is 0; the hot air pressure intensity of the lower surface of the glass is (0.6 +/-0.1) bar, preferably 0.6bar in the interval of 1-70% of convection heating time (namely preheating treatment time); the pressure intensity of the hot air on the lower surface of the glass is uniformly reduced from (0.6 +/-0.1) bar to 0, preferably from 0.6bar to 0 in 70-80% of convection heating time interval; the pressure intensity of the hot air on the upper surface of the glass in 80-100% of the convection heating time interval is 0.

Wherein, the heating temperature of the upper part in the tempering furnace in the heat treatment process in the step B) is more than or equal to 695 ℃, and preferably is 695-plus 730 ℃; the heating temperature of the lower part is more than or equal to 705 ℃; preferably 705-730 ℃; the heat treatment time is more than or equal to 190s, preferably 190-615 s.

Particularly, the preheating treatment time is the same as the heat treatment time in the toughening treatment process.

Particularly, when 6mm float glass is used for the replacement treatment, the heating temperature of the upper part of the tempering furnace is (715 +/-5) DEG C, preferably 715 ℃ in the heat treatment process; the lower heating temperature is (715 +/-5) DEG C, and preferably 715 ℃; the heat treatment time is 190s-200s, preferably 190 s; when 8mm float glass is used for replacement treatment, the heating temperature of the upper part of the toughening furnace in the heat treatment process is 730 +/-5 ℃, and preferably 730 ℃; the lower heating temperature is (730 +/-5) DEG C, and preferably is 730 ℃; the heat treatment time is 250s-270s, preferably 260 s; when 10mm float glass is used for the replacement treatment, the heating temperature of the upper part of the toughening furnace in the heat treatment process is 705 +/-5 ℃, and 705 ℃ is preferred; the lower heating temperature is (710 +/-5) DEG C, and is preferably 710 ℃; the heat treatment time is 330s-350s, preferably 347.5 s; when 12mm float glass is used for the replacement treatment, the heating temperature of the upper part of the toughening furnace in the heat treatment process is 705 +/-5 ℃, and 705 ℃ is preferred; the lower heating temperature is (710 +/-5) DEG C, and is preferably 710 ℃; the heat treatment time is 350-365s, preferably 355 s; when 15mm float glass is used for the displacement treatment, the heating temperature of the upper part of the tempering furnace is (695 +/-5) DEG C, preferably 695 ℃; the lower heating temperature is (705 +/-5) DEG C, and 705 ℃ is preferred; the heat treatment time is 430-450s, preferably 440 s; when 19mm float glass is used for the displacement treatment, the heating temperature of the upper part of the tempering furnace is (695 +/-5) DEG C, preferably 695 ℃; the lower heating temperature is (705 +/-5) DEG C, and 705 ℃ is preferred; the heat treatment time is 600-625s, preferably 615 s.

Wherein, the cooling treatment in the step C) comprises the steps of firstly carrying out quenching treatment on the heat-treated glass under the condition that the air pressure is 6000-8000Pa, carrying out cooling treatment for at least 30s and then carrying out cooling treatment under the condition that the air pressure is 4500-6500Pa until the temperature of the glass is less than or equal to 60 ℃.

Particularly, after the quenching treatment is carried out on the glass after the heat treatment for 35 to 500 seconds under the condition that the wind pressure is 6500-8000Pa, the preferable time is 50 to 450 seconds; then, under the condition that the wind pressure is 5000-6000Pa, the glass is subjected to cooling treatment for 35-500s, and the preferable time is 50-450 s; cooling treatment is carried out until the glass temperature is reduced to 40-60 ℃.

In particular, the air temperature during the quenching treatment is 5 to 35 ℃, preferably 15 to 30 ℃.

In particular, when 6mm float glass is used for the replacement treatment, the quenching air pressure is 7500-8000Pa, preferably 8000 Pa; the quenching time is 35-65s, preferably 50-60 s; the air pressure of the cooling treatment is 6000-6500Pa, preferably 6000Pa, and the time of the cooling treatment is 35-65s, preferably 50-60 s; when 8mm float glass is used for replacement treatment, the quenching air pressure is 7500-8000Pa, preferably 8000 Pa; the quenching time is 90-130s, preferably 100-120 s; the air pressure of the cooling treatment is 6000-; when 10mm float glass is used for replacement treatment, the quenching air pressure is 7500-8000Pa, preferably 7500 Pa; the quenching time is 180-210s, preferably 190-200 s; the air pressure for cooling treatment is 4500-; when 12mm float glass is used for the replacement treatment, the quenching air pressure is 7000-8000Pa, preferably 7500 Pa; the quenching time is 200-230s, preferably 215-220 s; the air pressure for the temperature reduction treatment is 5000-; when 15mm float glass is used for replacement treatment, the quenching air pressure is 6500-7000Pa, preferably 6500 Pa; the quenching time is 310-365s, preferably 330-350 s; the air pressure for cooling treatment is 5000-; when 19mm float glass is used for replacement treatment, the quenching air pressure is 6000-6500Pa, preferably 6500 Pa; the quenching time is 400-500s, preferably 420-450 s; the air pressure for the temperature reduction treatment is 4500-.

Wherein, the glass carries out reciprocating motion in the tempering furnace at the speed of 80-300mm/s in the process of carrying out the tempering treatment.

Particularly, in the process of preheating treatment, when 6-10mm float glass is used in the replacement treatment, the reciprocating speed of the glass in the preheating section of the toughening furnace is 80-300 mm/s; when float glass of 12-15mm is used, the reciprocating speed of the glass in the preheating section of the toughening furnace is 90-210 mm/s; when using float glass with the thickness of 19mm, the reciprocating speed of the glass in the preheating section of the toughening furnace is 80-200 mm/s.

Particularly, in the heat treatment process, when 6-10mm float glass is used in the replacement treatment, the reciprocating speed of the glass in the heating section of the toughening furnace is 80-300 mm/s; when float glass of 12-15mm is used, the reciprocating speed of the glass in the heating section of the toughening furnace is 90-210 mm/s; when using float glass with the thickness of 19mm, the reciprocating speed of the glass in the heating section of the toughening furnace is 80-200 mm/s.

Particularly, when 6-19mm float glass is used in the replacement treatment in the cooling treatment process, the reciprocating speed of the glass in the cooling section of the tempering furnace is 100-120 mm/s.

Compared with the prior art, the invention has the following advantages and benefits:

1. the fireproof glass prepared by the method has good fireproof performance, the glass still keeps integrity after a fireproof experiment is carried out for 90min, the integrity is not lost, the fireproof integrity is more than 1.5h, effective time guarantee is provided for escape and fire extinguishment of people in a fire environment, and the use safety is high.

2. The fireproof glass prepared by the method obviously improves the surface stress value of the glass, has strong physical and thermal shock resistance, and has the physical and thermal shock resistance strength 6-12 times that of common float glass with the same thickness and 1.5-3 times that of toughened glass with the same thickness under the same condition;

3. the fireproof glass prepared by the method does not change the original visible light transmittance of the glass, and the visible light transmittance of the fireproof glass is high.

4. The method for preparing the fireproof glass has small influence on the environment in the process of preparing the fireproof glass, can be compounded into other building glass products, and has the advantages of simple operation, mild process conditions and low manufacturing cost.

5. The fireproof glass can be combined into glass with various functions, for example, two pieces of glass can be compounded into hollow glass, and the fireproof glass has the functions of energy conservation, heat insulation and sound insulation; the glass surface is plated with a layer of film, which has the effects of heat reflection, beautiful appearance and the like.

6. The process of preparing the fireproof glass adopts a chemical and physical toughening combined technology, the infiltration of potassium ions greatly reduces microcracks on the surface of the glass, and the surface of the glass is provided with a physical toughening pressure stress layer and a chemical treatment pressure stress layer, so that the mechanical strength and the thermal shock resistance strength of the glass are improved.

Detailed Description

The invention will be further described with reference to specific embodiments, and the advantages and features of the invention will become apparent as the description proceeds. These examples are illustrative only and do not limit the scope of the present invention in any way. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention, and that such changes and modifications may be made without departing from the spirit and scope of the invention.

Example 1

1. Prepared fire-proof liquid

1-1) preparing the raw materials (g) according to the following weight portion ratio

1-2) sequentially pouring raw materials of potassium nitrate, cesium nitrate, seven eight Switzerland, methacrylic acid, acetone and common salt into a plastic container filled with water, and stirring by using an electric stirrer at a stirring speed of 120rpm (usually 60-120rpm) to perform mixing treatment; the stirring time is 1.5 h;

1-3) stirring, mixing and processing the mixed solution for 1.5h, standing at the temperature of 25 ℃ for standing to ensure that the mixed solution is fully fused with each other to generate chemical reaction, and standing for 48h to obtain the glass fireproof composition liquid.

2. Replacement process

2-1) uniformly spraying the fire-retardant composition for glass on the surface of float glass with the thickness of 12mm, uniformly spraying two sides of the glass, and spraying 12g (usually 10-15g) of the fire-retardant composition per square meter of the glass surface;

2-2) horizontally standing the glass sprayed with the fireproof composition for replacement reaction, and rapidly replacing sodium ions, calcium ions, magnesium ions and the like on the surface of the common float glass by carrying out ion exchange reaction on the surface of the glass and the fireproof composition; wherein the replacement reaction temperature is 5 ℃, and the replacement time is 60 min;

3. cleaning and drying treatment

Feeding the glass subjected to the displacement reaction into a glass cleaning machine (New Fuqing brand 2540 type, New Fuchu mechanical Co., Ltd.) to operate at the speed of 5 m/min, and cleaning the glass by using a three-way water spraying system, wherein the water consumption for cleaning is 3-5 Kg/square meter, namely 3-5Kg of water is used for each square meter of glass; then, a fan is used for drying the surface of the glass, the drying treatment is carried out on the glass, the power of the fan is 30KW/h (usually 25-35KW/h), and the glass passes through a cleaning machine blowing drying system (air duct) at the speed of 5 m/min; the time for drying the glass surface is 3-5S;

4. tempering treatment

4-1) conveying the dried glass into a preheating section in a toughening furnace (Tamglaa2540 type toughening furnace) for preheating treatment, heating by hot air convection, blowing hot air from the top and the bottom to heat the glass entering the toughening furnace, wherein the preheating treatment temperature is 450 ℃; the glass moves back and forth in the hearth at the speed of 90-210mm/s, and preheating treatment 355s is carried out to obtain preheating treated glass; wherein;

intensity of hot air convection at top: in a convection heating time interval of 1-50% (namely 177.5s after the glass enters the toughening furnace), the convection pressure intensity of the top hot air is uniformly reduced from 1.8bar to 1.2 bar; keeping the convection pressure intensity of the top hot air at 1.2bar in 50-70% of convection heating time interval (from 177.5s to 248.5s after entering the tempering furnace); the convection pressure intensity of the top hot air is uniformly reduced from 1.2bar to 0 within 70-80% of the convection heating time interval (i.e. from 248.5s to 284s after entering the toughening furnace); the intensity of the convection pressure of the top hot air is 0 within 80-100% of the convection heating time interval;

bottom hot air convection strength: the intensity of the convection pressure of the hot air at the bottom in the preheating section of the toughening furnace is 0.6bar in a 1-70% convection heating time interval (namely from the time when the glass enters the toughening furnace to the time when the glass enters 248.5s later); the convection pressure intensity of the bottom in a 70-80% convection heating time interval (namely 248.5s to 284s after entering the toughening furnace) is uniformly reduced from 0.6bar to 0; the convection pressure intensity of the bottom hot air in 80-100% convection heating time interval (namely from 284s to 355s) is 0;

4-2) the preheated glass enters a heating section of a toughening furnace for heat treatment, and the top temperature and the bottom temperature of the heating section are kept at 705 ℃ and 710 ℃ respectively in the heat treatment process; heat treatment time 355 s; the glass moves back and forth in the hearth at the speed of 90-210 mm/s;

4-3) the tempered glass enters a cooling section of a tempering furnace, cooling treatment is carried out on the heat-treated glass in an air cooling mode, and the height between an upper air grid tuyere and a lower air grid tuyere and the surface of the glass is 25-30 mm:

firstly, rapidly quenching glass, wherein the quenching air pressure is controlled to be 7500Pa, and the cold air temperature is controlled to be 5-35 ℃; after rapid quenching for 215 seconds and 220 seconds, reducing the air pressure to 5000Pa and the cold air temperature to 5-35 ℃; the cooling time is 215-220 s; the glass moves back and forth in the air grid section at the speed of 100-120mm/s in the cooling treatment process; and (4) after the temperature of the glass is reduced to 40-60 ℃, removing the sheet to obtain the fireproof glass.

In general: when 12mm float glass is used for preparing the fireproof glass, the quenching air pressure is 7000-8000Pa, preferably 7500 Pa; the quenching time is 200-230s, preferably 215-220 s; the air pressure for the temperature reduction treatment is 5000-5500Pa, preferably 5000Pa, and the time for the temperature reduction treatment is 200-230s, preferably 215-220 s.

The rapid quenching is an important link in the glass toughening process and plays a role in determining the formation of the surface stress of the toughened glass. The larger the tempering quenching wind pressure is, the larger the surface stress value of the glass is (the surface stress of semi-tempered glass is 24-69 MPa, and the tempered glass is more than or equal to 90MPa), and the stronger the corresponding processing capacity is (the thinner the glass is, the larger the quenching wind pressure is, and the thicker the glass is, the smaller the quenching wind pressure is).

The basic requirement for quenching the glass is to cool the glass uniformly (7.4 ℃/10s for 6 mm; 5.2 ℃/10s for 8 mm; 4.4 ℃/10s for 10 mm; 3.8 ℃/10s for 12 mm; 15mm2.5 ℃/10 s; 1.9 ℃/10s for 19 mm) at a desired cooling rate to enable the glass to achieve a uniform distribution of stress.

Air is the cleanest cooling medium. For the air-cooling quenching method, the cooling speed is determined by the factors of air pressure, air temperature, air flow, distance between the nozzle and the glass, and the like, and the factors which can be generally controlled are the air pressure and the distance between the nozzle and the glass.

With the further cooling of the temperature of the inner and outer layers of the glass, the temperature of the surface layer of the glass is reduced to be below the transition temperature (the temperature of mutual conversion of glassy substances between a glassy state and a high elastic state is about 580 ℃), the surface layer of the glass is hardened to stop shrinking, and the inner layer continues shrinking until the temperature is reduced to the transition temperature. At this time, the glass surface layer forms compressive stress, and the inner layer forms tensile stress. At this time, the stress existing in the glass cannot be removed even if the temperature gradient disappears, and becomes a permanent stress.

By detecting that the surface stress of the toughened glass is more than or equal to 90Mpa, the granularity in any 50 multiplied by 50 region meets the 2 nd part of the safety glass for buildings of GB 16763.2-2009: and (4) entering a cooling section after the fragment requirement of toughened glass. The wind pressure of the cooling section depends on the production takt arrangement, and when the wind pressure of the cooling section is large, the production efficiency is high.

Example 2

1. Prepared fire-proof liquid

Same as in example 1

2. Replacement process

The amount of the fire-retardant composition sprayed was 10g/m except that the thickness of the float glass was 8mm²Otherwise, the same as in example 1;

3. cleaning and drying treatment

Same as in example 1

4. Tempering treatment

Except that the preheating treatment temperature in the step 4-1) is 475 ℃; the glass moves back and forth in the hearth at the speed of 80-300mm/s, and is preheated for 260 s; intensity of hot air convection at top: in the 1-50% convection heating time interval (namely from the time when the glass enters the toughening furnace to the time when the glass enters the 130 th second), the intensity of the convection pressure of the top hot air is 3.6 bar; the convection pressure intensity of the top hot air in a 50-70% convection heating time interval (namely 130s to 182s after entering the tempering furnace) is uniformly reduced from 3.6bar to 1.8 bar; uniformly reducing the convection pressure intensity of the top hot air from 1.8bar to 0 within 70-80% of the convection heating time interval (from 182s to 208s after entering the toughening furnace); the intensity of the convection pressure of the top hot air is 0 within 80-100% of the convection heating time interval (namely from 208s to 260 s); bottom hot air convection strength: the intensity of the convection pressure of the hot air at the bottom in the preheating section of the toughening furnace is 1.8bar in a 1-70% convection heating time interval (namely from the time when the glass enters the toughening furnace to the time 182s after the glass enters the toughening furnace); the convection pressure intensity of the bottom in a 70-80% convection heating time interval (namely from 182s to 208s after entering the toughening furnace) is uniformly reduced from 1.8bar to 0; the convection pressure intensity of the bottom hot air in 80-100% convection heating time interval (namely from 208s to 260s) is 0;

in the heat treatment process of the step 4-2), the top temperature of the heating section is kept at 730 ℃, and the bottom temperature is kept at 730 ℃; the heat treatment time is 260 s; the glass moves back and forth in the hearth at the speed of 80-300 mm/s;

step 4-3) controlling the quenching air pressure to be 8000Pa and the cold air temperature to be 5-35 ℃ in the cooling treatment process; after rapid quenching for 100-120s, the wind pressure is reduced to 6000Pa, and the cold wind temperature is 5-35 ℃; the cooling time is 100-120 s; the height between the upper and lower air grid nozzles and the surface of the glass is 15-20 mm; the same as example 1, except that the glass was reciprocated at a speed of 100-.

In general: when 8mm float glass is used for preparing the fireproof glass, the quenching air pressure is 7500-8000Pa, preferably 8000 Pa; the quenching time is 90-130s, preferably 100-120 s; the air pressure of the temperature reduction treatment is 6000-6500Pa, preferably 6000Pa, and the time of the temperature reduction treatment is 90-130s, preferably 100-120 s.

Example 3

1. Prepared fire-proof liquid

1-2) sequentially pouring raw materials of potassium nitrate, cesium nitrate, seven eight Switzerland, methacrylic acid, acetone and common salt into a plastic container filled with water, and stirring by using an electric stirrer at a stirring speed of 100rpm (usually 60-120rpm) to perform mixing treatment; the stirring time is 2 h;

1-3) stirring and mixing the mixed solution for 2 hours, standing the mixed solution at the temperature of 25 ℃, fully fusing the mixed solution with each other to generate oxidation and reduction reactions, and standing the mixed solution for 50 hours to obtain the glass fireproof liquid.

2. Replacement process

2-1) uniformly spraying the fire-retardant composition for glass on the surface of float glass with the thickness of 15mm, uniformly spraying two sides of the glass, and spraying 15g (usually 10-15g) of the fire-retardant composition on each square meter of the glass surface;

2-2) horizontally standing the glass sprayed with the fireproof composition for replacement reaction, and rapidly replacing sodium ions, calcium ions, magnesium ions and the like on the surface of the common float glass by carrying out ion exchange reaction on the surface of the glass and the fireproof composition; wherein the replacement reaction temperature is 20 ℃, and the replacement time is 30 min;

3. cleaning and drying treatment

The glass subjected to the displacement reaction is sent into a glass cleaning machine, the glass runs at the speed of 5 meters per minute, and the glass is cleaned by a three-water spraying system, wherein the water consumption for cleaning is 3-5Kg per square meter, namely 3-5Kg of water is used for each square meter of glass; then, a fan is used for drying the surface of the glass, the drying treatment is carried out on the glass, the power of the fan is 30KW/h, and the glass passes through a cleaning machine blowing drying system (air duct) at the speed of 5 m/min; the time for drying the glass surface is 3-5S;

4. tempering treatment

4-1) conveying the dried glass into a preheating section in a tempering furnace for preheating treatment, heating by adopting hot air convection, blowing hot air from the top and the bottom, and heating the glass entering the tempering furnace, wherein the preheating treatment temperature is 430 ℃; the glass moves back and forth in the hearth at the speed of 90-210mm/s, and the preheating treatment is carried out for 440s to obtain the preheating treated glass; wherein: intensity of hot air convection at top: in the 1-50% convection heating time interval (namely from the time when the glass enters the toughening furnace to the time 220s after the glass enters), the convection pressure intensity of the top hot air is uniformly reduced from 1.8bar to 1.2 bar; keeping the convection pressure intensity of the top hot air at 1.2bar in 50-70% of convection heating time interval (namely 220 s-308 s after entering the tempering furnace); uniformly reducing the convection pressure intensity of the top hot air from 1.2bar to 0 within 70-80% of the convection heating time interval (namely from 308s to 352s after entering the toughening furnace); the intensity of the convection pressure of the top hot air in 80-100% of the convection heating time interval (namely 352 s-440 s lower after entering the tempering furnace) is 0;

bottom hot air convection strength: the intensity of the bottom hot air convection pressure in the preheating section of the toughening furnace is 0.6bar in the 1-70% convection heating time interval (namely from the time when the glass enters the toughening furnace to the time 308s after the glass enters); the convection pressure intensity of the bottom in a 70-80% convection heating time interval (from 308s to 352s after entering the toughening furnace) is uniformly reduced from 0.6bar to 0; the convection pressure intensity of the bottom hot air in 80-100% of the convection heating time interval (namely from 352s to 440s) is 0;

4-2) Heat treatment

The preheated glass enters a heating section of a toughening furnace for heat treatment, and the top temperature and the bottom temperature of the heating section are kept to be 695 ℃ and 705 ℃ respectively in the heat treatment process; the heat treatment time is 440 s; the glass moves back and forth in the hearth at the speed of 90-210 mm/s;

4-3) Cooling treatment

The tempered glass enters a cooling section of a tempering furnace, the heat-treated glass is cooled in an air cooling mode, and the height between an upper air grid tuyere and a lower air grid tuyere and the surface of the glass is 25-30 mm:

firstly, rapidly quenching glass, wherein the quenching wind pressure is controlled to be 6500Pa, and the cold wind temperature is controlled to be 5-35 ℃; after rapid quenching for 330 seconds and 350 seconds, reducing the air pressure to 5000Pa and the cold air temperature to 5-35 ℃; the cooling time is 330 and 350 seconds; the height between the upper and lower air grid nozzles and the surface of the glass is 30-35 mm; the glass moves back and forth at the air grid section at the speed of 100-120 mm/s; and (4) after the temperature of the glass is reduced to 40-60 ℃, removing the sheet to obtain the fireproof glass.

In general: when the 15mm float glass is used for preparing the fireproof glass, the quenching wind pressure is 6500 and 7000Pa, preferably 6500 Pa; the quenching time is 310-365s, preferably 330-350 s; the air pressure for the temperature reduction treatment is 5000-5500Pa, preferably 5000Pa, and the time for the temperature reduction treatment is 310-365s, preferably 330-350 s.

Example 4

1. Prepared fire-proof liquid

Same as in example 3

2. Replacement process

The amount of the fire-retardant composition sprayed was 12g/m except that the thickness of the float glass was 10mm²The same procedure as in example 3 was repeated except that the temperature of the substitution treatment was 5 ℃ and the substitution time was 45 min;

3. cleaning and drying treatment

Same as in example 3

4. Tempering treatment

Except that the preheating treatment temperature in the step 4-1) is 450 ℃; the glass moves back and forth in the hearth at the speed of 80-300mm/s, and is preheated for 347.5 s; intensity of hot air convection at top: in the 1-50% convection heating time interval (namely from the time when the glass enters the toughening furnace to the time when the glass enters the 173.75s), the convection pressure intensity of the top hot air is 3.6 bar; the convection pressure intensity of the top hot air in a 51-70% convection heating time interval (namely from 173.75s to 243.25s after entering the tempering furnace) is uniformly reduced from 3.6bar to 1.8 bar; uniformly reducing the intensity of the convection pressure of the top hot air from 1.8bar to 0 within 71-80% of the convection heating time interval (namely from 243.25s to 278s after entering the toughening furnace); the intensity of the convection pressure of the top hot air is 0 within 81-100% of the convection heating time interval (namely from 278s to 347.5 s); bottom hot air convection strength: the intensity of the convection pressure of the bottom hot air in the preheating section of the toughening furnace is 1.8bar in a 1-70% convection heating time interval (namely from the time when the glass enters the toughening furnace to the time when the glass enters the 243.25s later); the intensity of the bottom convection pressure in the 71-80% convection heating time interval (namely from 243.25s to 278s after entering the toughening furnace) is uniformly reduced from 1.8bar to 0; the intensity of the convection pressure of the bottom hot air is 0 within 81-100% of the convection heating time interval (namely 278 s-347.5 s);

in the heat treatment process of the step 4-2), the top temperature of the heating section is kept at 705 ℃, and the bottom temperature is kept at 710 ℃; the heat treatment time is 347.5 s; the glass moves back and forth in the hearth at the speed of 80-300 mm/s;

controlling the quenching air pressure to be 7500Pa and the cold air temperature to be 5-35 ℃ in the cooling treatment process of the step 4-3); after rapid quenching for 190 seconds and 200 seconds, reducing the air pressure to 5000Pa and the cold air temperature to 5-35 ℃; the cooling time is 190 and 200 s; the height between the upper and lower air grid nozzles and the surface of the glass is 25-30 mm; the same as example 1, except that the glass was reciprocated at a speed of 100-.

In general: when the 10mm float glass is used for preparing the fireproof glass, the quenching air pressure is 7500-8000Pa, preferably 7500 Pa; the quenching time is 180-210s, preferably 190-200 s; the air pressure for the temperature reduction treatment is 4500-.

Example 5

1. Prepared fire-proof liquid

1-2) sequentially pouring raw materials of potassium nitrate, cesium nitrate, seven eight Switzerland, methacrylic acid, acetone and common salt into a plastic container filled with water, and stirring by using an electric stirrer at a stirring speed of 60rpm (usually 60-120rpm) to perform mixing treatment; the stirring time is 2 h;

1-3) stirring and mixing the mixed solution for 2 hours, standing the mixed solution at the temperature of 25 ℃, fully fusing the mixed solution with each other to generate oxidation and reduction reactions, and standing the mixed solution for 60 hours to obtain the glass fireproof liquid.

2. Replacement process

2-1) uniformly spraying the fire-retardant composition for glass on the surface of float glass with the thickness of 19mm, uniformly spraying two sides of the glass, and spraying 15g (usually 10-15g) of the fire-retardant composition per square meter of the glass surface;

2-2) horizontally standing the glass sprayed with the fireproof composition for replacement reaction, and rapidly replacing sodium ions, calcium ions, magnesium ions and the like on the surface of the common float glass by carrying out ion exchange reaction on the surface of the glass and the fireproof composition; wherein the replacement reaction temperature is 15 ℃, and the replacement time is 45 min;

3. cleaning and drying treatment

4. tempering treatment

4-1) preheating treatment

Sending the dried glass into a preheating section in a tempering furnace for preheating treatment, heating by hot air convection, blowing hot air from the top and the bottom, and heating the glass entering the tempering furnace, wherein the preheating treatment temperature is 430 ℃; the glass moves back and forth in the hearth at the speed of 80-200mm/s, and preheating treatment is carried out for 615s to obtain preheating treated glass; wherein: intensity of hot air convection at top: in the 1-50% convection heating time interval (namely 307.5s after the glass enters the toughening furnace), the convection pressure intensity of the top hot air is uniformly reduced from 1.8bar to 1.2 bar; keeping the convection pressure intensity of the top hot air at 1.2bar in a 50-70% convection heating time interval (from 307.5s to 430.5s after entering the toughening furnace); the convection pressure intensity of the top hot air is uniformly reduced from 1.2bar to 0 within 70-80% of the convection heating time interval (namely from 430.5s to 492s after entering the toughening furnace); the intensity of the convection pressure of the top hot air in 80-100% convection heating time interval (from 492s to 615s) is 0; bottom hot air convection strength: the intensity of the convection pressure of the hot air at the bottom in the preheating section of the toughening furnace is 0.6bar in a 1-70% convection heating time interval (namely from the time when the glass enters the toughening furnace to the time when the glass enters the toughening furnace for 430.5 s); the intensity of the bottom convection pressure in a 70-80% convection heating time interval (namely from 430.5s to 492s after entering the toughening furnace) is uniformly reduced from 0.6bar to 0; the intensity of the convection pressure of the bottom hot air is 0 in 80-100% of the convection heating time interval (from 492s to 615 s);

4-2) Heat treatment

The preheated glass enters a heating section of a toughening furnace for heat treatment, and the top temperature and the bottom temperature of the heating section are kept to be 695 ℃ and 705 ℃ respectively in the heat treatment process; heat treatment time 615 s; the glass moves back and forth in the hearth at the speed of 80-200 mm/s;

4-3) Cooling treatment

The tempered glass enters a cooling section of a tempering furnace, the heat-treated glass is cooled in an air cooling mode, and the height between an upper air grid tuyere and a lower air grid tuyere and the surface of the glass is 30-35 mm:

firstly, rapidly quenching glass, wherein the quenching wind pressure is controlled to be 6500Pa, and the cold wind temperature is controlled to be 5-35 ℃; after rapid quenching for 420 and 450 seconds, reducing the air pressure to 5000Pa and the cold air temperature to 5-35 ℃; the cooling time is 420-450 s; the glass moves back and forth in the air grid section at the speed of 100-120mm/s in the cooling treatment process; and (4) after the temperature of the glass is reduced to 40-60 ℃, removing the sheet to obtain the fireproof glass.

In general: when 19mm float glass is used for preparing the fireproof glass, the quenching air pressure is 6000-6500Pa, and preferably 6500 Pa; the quenching time is 400-500s, preferably 420-450 s; the air pressure for the temperature reduction treatment is 4500-.

Example 6

1. Prepared fire-proof liquid

Same as in example 5

2. Replacement process

The amount of the fire-retardant composition sprayed was 10g/m except that the thickness of the float glass was 6mm²The same procedure as in example 5 was repeated except that the temperature of the substitution treatment was 5 ℃ and the substitution time was 60 min;

3. cleaning and drying treatment

Same as in example 3

4. Tempering treatment

Except that the preheating treatment temperature in the step 4-1) is 475 ℃; the glass moves back and forth in the hearth at the speed of 80-300mm/s, and is preheated for 190 s; intensity of hot air convection at top: in the 1-50% convection heating time interval (i.e. from the time when the glass enters the toughening furnace to the time when the glass enters the 95 th second), the intensity of the convection pressure of the top hot air is 3.6 bar; the convection pressure intensity of the top hot air in a 51-70% convection heating time interval (from 95s to 133s after entering the tempering furnace) is uniformly reduced from 3.6bar to 1.8 bar; the convection pressure intensity of the top hot air is uniformly reduced from 1.8bar to 0 within 71-80% of the convection heating time interval (namely from 133s to 152s after entering the toughening furnace); the intensity of the convection pressure of the top hot air is 0 within 81-100% of the convection heating time interval (namely from 152s to 190 s); bottom hot air convection strength: the intensity of the convection pressure of the hot air at the bottom in the preheating section of the toughening furnace is 1.8bar in a 1-70% convection heating time interval (namely from the time when the glass enters the toughening furnace to the time when the glass enters the 133 th section); the intensity of the bottom convection pressure in the 71-80% convection heating time interval (from 133s to 152s after entering the toughening furnace) is uniformly reduced from 1.8bar to 0; the intensity of the convection pressure of the bottom hot air is 0 within 81-100% of the convection heating time interval (namely from 152s to 190 s);

step 4-2), keeping the temperature of the top of the heating section at 715 ℃ and the temperature of the bottom of the heating section at 715 ℃ in the heat treatment process; the heat treatment time is 190 s; the glass moves back and forth in the hearth at the speed of 80-300 mm/s;

step 4-3) controlling the quenching air pressure to be 8000Pa and the cold air temperature to be 5-35 ℃ in the cooling treatment process; rapidly quenching for 50-60s, reducing the wind pressure to 6000Pa and the cold air temperature to 5-35 ℃; the cooling time is 50-60 s; the height between the upper and lower air grid nozzles and the surface of the glass is 15-20 mm; the same as example 5, except that the glass was reciprocated at a speed of 100-.

In general: when the 6mm float glass is used for preparing the fireproof glass, the quenching air pressure is 7500-8000Pa, preferably 8000 Pa; the quenching time is 35-65s, preferably 50-60 s; the air pressure of the temperature reduction treatment is 6000-6500Pa, preferably 6000Pa, and the time of the temperature reduction treatment is 35-65s, preferably 50-60 s.

The glass tempering heat treatment process adopts a tempering technology for prolonging the heat treatment time (namely, the heating time is prolonged in the glass tempering treatment process, namely, the glass which is not subjected to chemical reaction can not reciprocate in the tempering furnace for a long time, if the glass moves in the hearth of the tempering furnace for a long time and collapses in the tempering furnace due to softening temperature to cause an accident), and the glass quenching air pressure is improved, namely, the cold air convection pressure intensity in the tempering furnace quenching section is high in the fireproof glass preparation process by using the fireproof liquid, namely, the air pressure value of the cold air is high), so that the glass with high stress index is obtained. The glass surface stress value reflects the time of fire integrity of the glass in a fire situation, with higher stress values giving longer fire integrity.

Comparative example 1 preparation of ordinary 12mm tempered glass

1. Cleaning and drying treatment

The float glass with the thickness of 12mm used in the example 1 is sent into a glass cleaning machine (New Rich mechanical Co., Ltd., Fuqing, model 2540), the glass runs at the speed of 5 meters per minute, three water spraying systems are used for cleaning the glass, the water consumption for cleaning is 3-5Kg per square meter, namely 3-5Kg of water is used per square meter of the glass; then, a fan is used for drying the surface of the glass, the drying treatment is carried out on the glass, the power of the fan is 30KW/h (usually 25-35KW/h), and the glass passes through a cleaning machine blowing drying system (air duct) at the speed of 5 m/min; the time for drying the glass surface is 3-5S;

2. tempering treatment

2-1) preheating treatment

Sending the dried glass into a tempering furnace for hot air convection heating and temperature rise treatment, wherein the hot air convection heating is usually carried out on the glass entering the tempering furnace at the top and the bottom; firstly, preheating glass in a preheating furnace section, wherein the top temperature is 450 ℃, the bottom temperature is 470 ℃ and the preheating time is 320s (usually 310 and 350s) in the preheating process; the glass moves back and forth in the hearth at the speed of 90-210 mm/s; wherein;

intensity of hot air convection at top: in the convection heating time interval of 1-50% (namely from the glass entering the toughening furnace to the 160 th s after entering), the intensity of the convection pressure of the top hot air is uniformly reduced from 30% to 20% (namely from 1.8bar to 1.2 bar); the convection pressure intensity of the top hot air in a 50-70% convection heating time interval (from 160s to 224s after entering the tempering furnace) is kept at 20% (namely the pressure intensity of the top hot air is kept at 1.2 bar); the convection pressure intensity of the top hot air is uniformly reduced from 20% to 0 (i.e. from 1.2bar to 0) in 70% -80% of the convection heating time interval (i.e. from 224s to 256s after entering the toughening furnace), and the convection pressure intensity of the top hot air is 0 in 80% -100% of the convection heating time interval (i.e. from 256s to 320 s); bottom hot air convection strength: the intensity of the convection pressure of the hot air at the bottom in the preheating section of the toughening furnace is 10 percent (namely the convection pressure of the hot air is 0.6bar) in a 1 to 70 percent convection heating time interval (namely the time from the glass entering the toughening furnace to the 224 th time after the glass enters); the convection pressure intensity of the bottom part in a 70-80% convection heating time interval (namely from 224s to 256s after entering the toughening furnace) is uniformly reduced from 10% to 0 (namely from 0.6bar to 0), and the convection pressure intensity of the bottom part hot air in an 80-100% convection heating time interval (namely from 256s to 320s) is 0;

2-2) Heat treatment

The preheated glass enters a heating section of a toughening furnace for heat treatment, and the top temperature and the bottom temperature of the heating section are kept at 690 ℃ and 700 ℃ respectively in the heat treatment process; heat treatment time 320s (typically 310-350 s); the glass moves back and forth in the hearth at the speed of 90-210 mm/s;

2-3) Cooling treatment

The heat-treated glass enters a cooling section of a toughening furnace, the glass after heating treatment is cooled in an air cooling mode, and the height between an upper air grid tuyere and a lower air grid tuyere and the surface of the glass is 50-60 mm:

firstly, quenching glass, wherein the quenching air pressure is controlled to be 130-150Pa, and the cold air temperature is controlled to be 5-35 ℃; after quenching for 310-350s, the wind pressure is increased to 1300-1500Pa, and the cold wind temperature is 5-35 ℃; the cooling time is 310-350 s; the glass moves back and forth in the air grid section at the speed of 100-150mm/s in the cooling treatment process; and after the glass temperature is reduced to 40-60 ℃, the sheet is removed, and the toughened glass with the thickness of 12mm is obtained.

Comparative example 1A ordinary 12mm float glass

A12 mm float glass for fire-resistant glass prepared in example 1 was used as comparative example 1A.

Comparative example 2 preparation of ordinary 8mm tempered glass

1. Cleaning and drying treatment

The comparative example 1 was repeated except that a float glass having a thickness of 8mm was used in example 2;

2. tempering treatment

Except that the top temperature in the preheating treatment process in the step 2-1) is 460 ℃, the bottom temperature is 475 ℃, and the preheating time is 200 (generally 195-225) s; the glass moves back and forth in the hearth at the speed of 80-300 mm/s; wherein:

intensity of hot air convection at top: in the 1-50% convection heating time interval (namely from the time when the glass enters the toughening furnace to the time when the glass enters the toughening furnace for 100s), the convection pressure intensity of the top hot air is 3.6 bar; the convection pressure intensity of the top hot air in a 50-70% convection heating time interval (from 100s to 140s after entering the tempering furnace) is uniformly reduced from 3.6bar to 1.8 bar; uniformly reducing the convection pressure intensity of the top hot air from 1.8bar to 0 within 70-80% of the convection heating time interval (from 140s to 160s after entering the toughening furnace); the intensity of the convection pressure of the top hot air is 0 within 80-100% of the convection heating time interval (namely from 160s to 200 s); bottom hot air convection strength: the intensity of the convection pressure of the hot air at the bottom in the preheating section of the toughening furnace is 1.8bar in a 1-70% convection heating time interval (namely from the time when the glass enters the toughening furnace to the 140 th time after the glass enters); the convection pressure intensity of the bottom in a 70-80% convection heating time interval (from 140s to 160s after entering the toughening furnace) is uniformly reduced from 1.8bar to 0; the intensity of the convection pressure of the bottom hot air is 0 within 80-100% of the convection heating time interval (namely from 160s to 200 s);

in the step 2-2) of the heat treatment process, the top temperature of the heating section is kept to be 695 ℃, and the bottom temperature is kept to be 705 ℃; the heat treatment time is 200s (usually 195-225 s); the glass moves back and forth in the hearth at the speed of 80-300 mm/s;

controlling the quenching air pressure to be 450-600Pa and the cold air temperature to be 5-35 ℃ in the cooling treatment process in the step 2-3); after quenching for 195-225s, the wind pressure is increased to 1500-2500Pa, and the cold wind temperature is 5-35 ℃; the cooling time is 195-225 s; the height between the upper and lower air grid nozzles and the surface of the glass is 15-20 mm; the same as in comparative example 1, except that the glass was reciprocated inside the air grid section at a speed of 100-.

Comparative example 2A ordinary 8mm float glass

8mm float glass for fire-proof glass prepared in example 2 was used as comparative example 2A.

Comparative example 3 preparation of ordinary 15mm tempered glass

1. Cleaning and drying treatment

The comparative example 1 was repeated except that a float glass having a thickness of 15mm was used in example 3;

2. tempering treatment

Except that the top temperature in the preheating treatment process in the step 2-1) is 450 ℃, the bottom temperature is 470 ℃ and the preheating time is 400s (usually 390-430 s); the glass moves back and forth in the hearth at the speed of 90-210 mm/s; wherein; top and bottom hot air convection strength: in the 1-50% convection heating time interval (namely from the glass entering the toughening furnace to the 200 th s after the glass enters), the intensity of the convection pressure of the top hot air is uniformly reduced from 15% to 10% (namely from 0.9bar to 0.6 bar); the convection pressure intensity of the top hot air and the bottom hot air in a 50-70% convection heating time interval (from 200s to 280s after entering the tempering furnace) is kept at 10% (namely the pressure intensity of the top hot air is kept at 0.6 bar); the convection pressure intensity of the top hot air is uniformly reduced from 10% to 0 (namely, from 0.6bar to 0) in 70% -80% of convection heating time interval (namely from 280s to 320s after entering the toughening furnace), and the convection pressure intensity of the top hot air is 0 in 80% -100% of convection heating time interval (namely from 320s to 400 s);

step 2-2), the top temperature of the heat treatment heating section is 690 ℃, and the bottom temperature is 700 ℃; heat treatment time 400s (typically 390-430 s); the glass moves back and forth in the hearth at the speed of 90-210 mm/s; controlling the quenching air pressure to be 100-130Pa and the cold air temperature to be 5-35 ℃ in the cooling treatment process in the step 2-3); after quenching for 195-215s, the wind pressure is increased to 1000-1500Pa, and the cold wind temperature is 5-35 ℃; the cooling time is 195-215 s; the height between the upper and lower air grid nozzles and the surface of the glass is 45-50 mm; the same as in comparative example 1, except that the glass was reciprocated inside the air grid section at a speed of 100-.

Comparative example 3A ordinary 15mm float glass

15mm float glass for fire-resistant glass prepared in example 3 was used as comparative example 3A.

Comparative example 4 preparation of ordinary 10mm tempered glass

1. Cleaning and drying treatment

The comparative example 1 was repeated except that a float glass having a thickness of 10mm was used in example 4;

2. tempering treatment

Except that the top temperature in the preheating treatment process in the step 2-1) is 450 ℃, the bottom temperature is 470 ℃ and the preheating time is 250s (usually 240-; the glass moves back and forth in the hearth at the speed of 80-300 mm/s; wherein;

intensity of hot air convection at top: in the 1-50% convection heating time interval (namely from the time when the glass enters the toughening furnace to the time when the glass enters the 125 th second), the convection pressure intensity of the top hot air is 3.6 bar; the convection pressure intensity of the top hot air in a 50-70% convection heating time interval (namely from 125s to 175s after entering the tempering furnace) is uniformly reduced from 3.6bar to 1.8 bar; uniformly reducing the convection pressure intensity of the top hot air from 1.8bar to 0 within 70-80% of the convection heating time interval (from 175s to 200s after entering the toughening furnace); the intensity of the convection pressure of the top hot air is 0 within 80-100% of the convection heating time interval (namely from 200s to 250 s); bottom hot air convection strength: the intensity of the convection pressure of the hot air at the bottom in the preheating section of the toughening furnace is 1.8bar in a 1-70% convection heating time interval (namely from the time when the glass enters the toughening furnace to the time 175s after the glass enters); the convection pressure intensity of the bottom in a 70-80% convection heating time interval (from 175s to 200s after entering the toughening furnace) is uniformly reduced from 1.8bar to 0; the convection pressure intensity of the bottom hot air is 0 within 80-100% of the convection heating time interval (namely from 200s to 250 s);

step 2-2), the top temperature of the heat treatment heating section is 690 ℃, and the bottom temperature is 700 ℃; heat treatment time 250s (typically 240-260 s); the glass moves back and forth in the hearth at the speed of 80-300 mm/s; controlling the quenching air pressure to be 250-280Pa and the cold air temperature to be 5-35 ℃ in the cooling treatment process in the step 2-3); after quenching for 120-130s, the wind pressure is increased to 1000-1500Pa, and the cold wind temperature is 5-35 ℃; the cooling time is 120-130 s; the height between the upper and lower air grid nozzles and the surface of the glass is 45 mm; the same as in comparative example 1, except that the glass was reciprocated inside the air grid section at a speed of 100-.

Comparative example 4A ordinary 120mm float glass

A10 mm float glass fire-proof glass prepared in example 4 was used as comparative example 4A.

Comparative example 5 preparation of ordinary 19mm tempered glass

1. Cleaning and drying treatment

The comparative example 1 was repeated except that a float glass having a thickness of 19mm was used in example 5;

2. tempering treatment

Except that the top temperature in the preheating treatment process in the step 2-1) is 450 ℃, the bottom temperature is 470 ℃ and the preheating time is 500s (generally 475-; the glass moves back and forth in the hearth at the speed of 80-200 mm/s; wherein; top and bottom hot air convection strength: in the 1% -50% convection heating time interval (i.e. from the glass entering the toughening furnace to the 250 th s after entering), the convection pressure intensity of the hot air at the top and the bottom is uniformly reduced from 10% to 8% (i.e. from 0.6bar to 0.48 bar); the convection pressure intensity of the top and bottom hot air is uniformly reduced from 8% to 0 (namely from 0.48bar to 0) in 50% -80% of convection heating time interval (namely from 250s to 400s after entering the toughening furnace), and the convection pressure intensity of the top and bottom hot air is 0 in 80% -100% of convection heating time interval (namely from 400s to 500 s);

step 2-2), the temperature of the top of the heat treatment heating section is 685 ℃, and the temperature of the bottom of the heat treatment heating section is 695 ℃; heat treatment time 475-; the glass moves back and forth in the hearth at the speed of 80-200 mm/s; controlling the quenching air pressure to be 80-100Pa and the cold air temperature to be 5-35 ℃ in the cooling treatment process in the step 2-3); after quenching for 237.5-262.5s, the wind pressure is increased to 1000-1500Pa, and the cold wind temperature is 5-35 ℃; cooling for 237.5-262.5 s; the height between the upper and lower air grid nozzles and the surface of the glass is 45-50 mm; the same as in comparative example 1, except that the glass was reciprocated inside the air grid section at a speed of 100-.

Comparative example 5A ordinary 19mm float glass

19mm float glass, fire-resistant glass from example 5, was used as control 5A.

Comparative example 6 preparation of ordinary 6mm tempered glass

1. Cleaning and drying treatment

The comparative example 1 was repeated except that a float glass having a thickness of 6mm was used in example 6;

2. tempering treatment

Except that the top temperature in the preheating treatment process in the step 2-1) is 460 ℃, the bottom temperature is 475 ℃, and the preheating time is 160s (usually 150 and 180 s); the glass moves back and forth in the hearth at the speed of 80-300 mm/s; wherein;

intensity of hot air convection at top: in the 1-50% convection heating time interval (namely from the time when the glass enters the toughening furnace to the time when the glass enters the 80 th second), the convection pressure intensity of the top hot air is 3.6 bar; the convection pressure intensity of the top hot air in a 50-70% convection heating time interval (namely 80 s-112 s after entering the tempering furnace) is uniformly reduced from 3.6bar to 1.8 bar; the convection pressure intensity of the top hot air is uniformly reduced from 1.8bar to 0 within 70-80% of the convection heating time interval (from 112s to 128s after entering the toughening furnace); the intensity of the convection pressure of the top hot air is 0 within 80-100% of the convection heating time interval (namely from 128s to 160 s); bottom hot air convection strength: the intensity of the convection pressure of the hot air at the bottom in the preheating section of the toughening furnace is 1.8bar in a 1-70% convection heating time interval (namely from the time when the glass enters the toughening furnace to the time 112s after the glass enters); the bottom convection pressure intensity in a 70-80% convection heating time interval (namely from 112s to 128s after entering the toughening furnace) is uniformly reduced from 1.8bar to 0; the intensity of the convection pressure of the bottom hot air is 0 within 80-100% of the convection heating time interval (namely from 128s to 160 s);

step 2-2), the top temperature of the heat treatment heating section is 705 ℃, and the bottom temperature is 710 ℃; the heat treatment time is 150-; the glass moves back and forth in the hearth at the speed of 80-300 mm/s; controlling the quenching air pressure to be 2100-2600Pa and the cold air temperature to be 5-35 ℃ in the cooling treatment process in the step 2-3); after quenching for 75-90s, the wind pressure is increased to 2500-3800Pa, and the cold wind temperature is 5-35 ℃; the cooling time is 75-90 s; the height between the upper and lower air grid nozzles and the surface of the glass is 35-45 mm; the same as in comparative example 1, except that the glass was reciprocated inside the air grid section at a speed of 100-.

Comparative example 6A ordinary 6mm float glass

6mm float glass for fire-proof glass prepared in example 6 was used as comparative example 6A.

Test example 1 Property test of glass

1. Testing of fire resistance, impact resistance and appearance quality

According to the national standard GB15763.1-2009 part 1 of safety glass for construction: method of fire-resistant glass the fire-resistant glass prepared in examples 1 to 6, the ordinary tempered glass of comparative examples 1 to 6, and the float glass of comparative examples 1A to 6A were measured for fire resistance, appearance quality, impact resistance, shot bag impact resistance, and thermal shock resistance.

Wherein, the impact resistance test is carried out according to the national standard GB15763.2-2005 part 2 of safety glass for construction: the method of ' impact resistance ' of toughened glass ' tests the impact resistance of the glass, and adopts a steel ball with the diameter of 63.5mm and the mass of 1040g and smooth surface to be placed at the height of 1000mm from the surface of a fireproof glass stone sample, so that the steel ball freely falls, the impact point is within the range of 25mm from the center of the sample, and each sample impacts for 1 time.

According to GB15763.2-2005 "part 2 of safety glass for buildings: the method of the shot-bag impact performance test of toughened glass tests the shot-bag impact performance of the glass, the maximum diameter center position of a 45 plus or minus 0.1Kg shot-bag is used at normal temperature to keep 300mm, 750mm and 1200mm free swing and fall, and the single piece of fireproof glass is not damaged; the toughened glass is allowed to be damaged, and the common glass is 100 percent damaged when the thickness is 300 mm;

according to GB15763.2-2005 "part 2 of safety glass for buildings: the thermal shock resistance of the glass is tested by a thermal shock resistance method of toughened glass, glass samples are respectively placed in an oven at the temperature of 200 +/-2 ℃, the temperature is kept for more than 4 hours, the samples are taken out and then are vertically immersed in an ice-water mixture at the temperature of 0 ℃, the samples are immersed in water at the height of more than 1/3, and the damage of the glass is observed after 5 minutes. The single piece of fireproof glass is not broken, the toughened glass is possibly damaged, and the common glass is 100 percent damaged.

The measurement results are shown in table 1.

TABLE 1 fire resistance and impact resistance test results for fire-resistant glass

The test result shows that: the fireproof glass prepared by the fireproof liquid treatment has strong physical impact resistance and thermal impact resistance, and the physical impact resistance and the thermal impact resistance of the fireproof glass are 6-12 times of those of common float glass and 1.5-3 times of those of toughened glass under the same condition); the shot-bag impact performance of the comparative examples 1-6 meets the national standard (GB15763.2-2005 "safety glass for buildings part 2: toughened glass"), wherein the toughened glass of the comparative examples 2 and 6 has breakage at the impact height of 750mm and 1200mm, but meets the requirements of the national standard, while the fireproof glass of the invention has no breakage at 300mm, 750mm and 1200 mm; the glass has excellent fire-resistant integrity, and provides effective time guarantee for escape and fire extinguishment of people in a fire environment.

The fireproof glass prepared in the embodiments 1-6 of the invention has good appearance quality and no edge explosion; no calculus, crack and unfilled corner; no scratch (the width is less than or equal to 0.1mm, the length is less than or equal to 50mm, the area per square meter is not more than 2, no scratch, the width is less than or equal to 0.1, the length is less than or equal to 50mm, the area per square meter is not more than 1, no scratch); the tempered glass prepared in comparative examples 1 to 6 and the original piece glass prepared in comparative examples 1A to 6A had good appearance and no edge pop; no calculus, crack and unfilled corner; no scratch (no more than 2 strips per square meter of slight scratch with the width of no more than 0.1mm and the length of no more than 50mm, no more than 1 strip per square meter of slight scratch with the width of no more than 0.1 and the length of no more than 50mm, no more than 1 strip per square meter).

Test example 2 surface stress value test of glass

The surface stress value of the fireproof glass is one of important data indexes for measuring the fireproof performance of products. The surface stress values of the fire-proof glass prepared in examples 1 to 6, the tempered glass prepared in comparative examples 1 to 6, and the original glass prepared in comparative examples 1A to 6A were measured by a glass surface stress meter (SMM-2 glass surface stress meter), and the specific method was as follows:

placing glass to be tested on a measuring table of a glass surface stress meter, enabling a tin immersion surface to face upwards, determining a measuring point according to the national standard GB17841-1999 model 6.4.1 of tempered glass and semi-tempered glass for curtain walls, wiping the surface position of the glass to be measured with alcohol, dripping a drop of refraction oil on the measuring position after 1 minute, and then placing the bottom surface of a prism of the glass surface stress meter on the refraction oil; adjusting the eyepiece of the glass surface stress meter, reading out the values of the upper and lower ends of the step in the horizontal axis of the coordinate line of the micrometer eyepiece along the visual field, and calculating the difference (i.e. the measured step height D)

The measured step height D × 3 is the surface stress value of the glass to be measured, and the measurement results are shown in table 3.

TABLE 3 measurement results of surface stress values of fire-resistant glass

	Surface stress (MPa)		Surface stress (MPa)
				Example 1	231	Comparative example 1	120
Example 2	225	Comparative example 2	99
				Example 3	237	Comparative example 3	117
Example 4	228	Comparative example 4	111
				Example 5	243	Comparative example 5	126
Example 6	222	Comparative example 6	96
				Comparative example 1A	24	Comparative example 4A	24
Comparative example 2A	24	Comparative example 5A	24
				Comparative example 3A	24	Comparative example 6A	24

The test results from table 3 show that: the larger the surface stress value is, the better the thermal shock resistance, physical shock resistance and fire-resistant integrity performance are.

Test example 3 bending strength test of glass

According to the national standard GB15763.1-2009 part 4 of safety glass for construction: method of homogeneous tempered glass "the bending strength of the fire-resistant glass produced in examples 1 to 6, the tempered glass produced in comparative examples 1 to 6, and the raw sheet glass of comparative examples 1A to 6A were measured, and the test results are shown in table 4.

TABLE 4 measurement results of bending strength of glass

	Flexural Strength (MPa)
		Examples 1 to 6	≥180
Comparative examples 1 to 6	≥120
		Comparative examples 1A to 6A	≥50

Test example 4 thermal stability test for producing fire-resistant glass

Thermal stability refers to the ability of a glass to withstand severe changes in temperature without failure.

According to GB15763.2-2005 "part 2 of safety glass for buildings: method for testing "thermal shock resistance" of tempered glass "fire-proof glass prepared in examples 1 to 6, tempered glass prepared in comparative examples 1 to 6, and original glass sheet of comparative examples 1A to 6A were placed in an oven at 200 ± 2 ℃ respectively, heat-preserved for 4 hours or more, immediately after taking out, the sample (300mm × 300mm) was vertically immersed in an ice-water mixture at 0 ℃, the sample height was maintained at 1/3 or more, and after 5 minutes, it was observed whether the glass was broken or not. The original piece of glass of the comparative examples 1A to 6A is 100% damaged, the toughened glass of the comparative examples 1 to 6 is not damaged, and the single piece of fireproof glass of the invention is not damaged;

the tempered glass prepared in the comparative examples 1 to 6 and the fireproof glass samples (300mm multiplied by 300mm) prepared in the inventive examples 1 to 6 are respectively placed in an oven at 250 +/-2 ℃, the temperature is kept for more than 4h, the samples are taken out and then vertically immersed in an ice-water mixture at 0 ℃, the height of the samples is kept above 1/3, and the samples are immersed in water for 5min to observe whether the glass is damaged or not. The toughened glass is broken, and the single fireproof glass is not broken.

The tempered glass prepared in comparative examples 1 to 6 and the fireproof glass samples (1100mm × 600mm) prepared in examples 1 to 6 of the present invention were vertically embedded in a fireproof furnace according to GB/T12513-2006 "method for testing fire resistance of glazed members", respectively, according to GB/T9978.1-2008 "method for testing fire resistance of building members part 1: the temperature rise curve in the method of general requirements is subjected to temperature rise heating, and the glass breakage time is observed in the heating process. The toughened glass is broken within 10 minutes or less, and the single piece of fireproof glass has the fire-resistant time of not less than 1.5 hours and is not broken.

The service temperature range of the toughened glass is-40-220 ℃, the temperature-endurable drastic change range can reach 200-220 ℃, while the general glass is only 70-100 ℃, and the temperature-endurable drastic change range of a single piece of fireproof glass can reach more than 600 ℃.

Claims

1. A preparation method of fireproof glass is characterized by comprising the steps of carrying out replacement treatment on the surface of glass and then carrying out toughening treatment on the glass.

2. The method according to claim 1, wherein the substitution treatment is performed by spraying a fire-retardant glass liquid onto the surface of the glass, and the surface of the glass is subjected to an ion exchange reaction with the fire-retardant liquid.

3. The method according to claim 2, wherein the glass fire-retardant liquid is prepared by the following steps in the following order:

1) preparing the following raw materials in parts by weight

2) Sequentially pouring raw materials of potassium nitrate, cesium nitrate, seven eight Swiss, methacrylic acid, acetone and salt into water, stirring and mixing;

3) and standing the uniformly stirred materials to obtain the material.

4. The preparation method of claim 3, wherein the raw materials in the step 1) comprise the following components in parts by weight:

5. the preparation method according to claim 3, wherein the standing treatment time in the step 3) is not less than 48 hours; the temperature of the standing treatment is 20-25 ℃.

6. The method according to claim 1, wherein the substitution treatment temperature is 5 ℃ or higher; the replacement treatment time is more than or equal to 30 min.

7. The method according to claim 1, wherein the tempering reaction comprises the steps of, in order:

B) Heat treating the preheated glass

8. The process according to claim 7, wherein the preheating temperature in step A) is 420-500 ℃, preferably 430-475 ℃; the preheating treatment time is more than or equal to 190s, preferably 190-615 s.

9. The process according to claim 7 or 8, wherein the upper heating temperature in the heat treatment in step B) is 695 ℃ or more, preferably 695-730 ℃; the heating temperature of the lower part is more than or equal to 705 ℃; preferably 705-730 ℃; the heat treatment time is more than or equal to 190s, preferably 190-615 s.

10. The preparation method as claimed in claim 7 or 8, wherein the cooling treatment in step C) comprises quenching the heat-treated glass at a wind pressure of 6000-8000Pa for at least 30s, and cooling the glass at a wind pressure of 4500-6500Pa until the temperature of the glass is less than or equal to 60 ℃.