WO2019051727A1

WO2019051727A1 - High-temperature coating for glass/glass ceramic thermocompression treatment and thermo-compression forming method for glass/glass ceramic

Info

Publication number: WO2019051727A1
Application number: PCT/CN2017/101763
Authority: WO
Inventors: 胡伟; 陈振宇; 索平平; 常瑞荆
Original assignee: 深圳市力沣实业有限公司
Priority date: 2017-09-14
Filing date: 2017-09-14
Publication date: 2019-03-21

Abstract

Disclosed is a high-temperature coating for a glass/glass ceramic thermocompression treatment, comprising inorganics and organics, wherein the inorganics comprise at least one amorphous particle, the amorphous particle is particles of the glass, and the organics comprise at least two of a resin, an organic solvent, a coupling agent, a film-forming agent, a defoaming agent, a dispersing agent, a levelling agent and a photoinitiator. The following steps are included in the thermo-compression formation of the glass/glass ceramic: coating the high-temperature coating on at least one surface of the glass/glass ceramic so as to obtain a coating layer, and drying same; performing a thermocompression treatment; and placing the glass or glass ceramic, after the thermocompression treatment, in a release agent to remove the coating layer.

Description

Hot press forming method for high temperature coating of glass/glass ceramic hot pressing and glass/glass ceramic

Technical field

The invention belongs to the field of glass processing, and in particular relates to a hot press forming method for a high temperature coating and a glass/glass ceramic for hot pressing of glass/glass ceramics.

Background technique

With the popularity of flexible display screens, the application of curved shaped protective glass for use with them is becoming more and more popular. On the other hand, the requirements for the speed and strength of wireless signals in handheld terminals are getting higher and higher. Under the circumstance, non-conductive hard materials such as glass and glass ceramics have become mainstream materials, and these hard materials are processed into a special-shaped structure by thermoforming to meet the comprehensive structural design of the handheld terminal; in the traditional optical industry, optical Most of the optical lenses in the lens are curved glass.

At present, the most popular method for forming curved glass and glass ceramics is hot press forming, which puts the processed glass into graphite, glass ceramic or metal mold, in a closed atmosphere filled with inert protective gas, in glass. It is applied under a high temperature environment (usually greater than 630 ° C) near the softening point to form it. However, the biggest drawback of this method is that the process temperature, time or pressure is not well controlled. During the molding process, the mold printing is easily transferred to the area where the surface of the glass to be processed is the most stressed, as well as other surface defects such as scratches and oranges. Leather, small bubbles, etc.; these molds usually have 10-20 The depth of μm, in order to remove these mold marks, it is necessary to polish the entire surface of the glass, and the polishing of these already formed curved shaped glass is very difficult, usually requires a brush with rare earth polishing powder for 1-2 hours of polishing. It is only possible to remove these mold marks on the entire surface. The current practice yield and efficiency are very low, the greater the dependence on the mold, the higher the requirements on the surface condition accuracy of the mold, the high processing cost, and the large use of rare earth and graphite is also not conducive to environmental protection.

Therefore, the prior art has drawbacks and is in urgent need of improvement.

technical problem

In order to solve the above technical problems, the present invention provides a hot press forming method for a high temperature coating of glass/glass ceramics and a glass/glass ceramic, which aims to overcome the existing hot pressing method of glass/glass ceramics. There are problems in it.

Technical solution

The present invention is achieved by a high temperature coating for glass/glass ceramic hot press treatment, the high temperature coating comprising inorganic substances and organic substances; the inorganic material comprising at least one amorphous particle, the amorphous particles being Glass particles; the organic substance includes at least two of a resin, an organic solvent, a coupling agent, a film former, an antifoaming agent, a dispersing agent, a leveling agent, and a photoinitiator.

Further, the mass ratio of the inorganic substance to the organic substance is 1: 0.05-20.

Further, the inorganic substance further includes an oxide having a crystal structure and a salt compound, and the oxide and the salt compound have a melting temperature of more than 630 °C.

Further, the resin includes at least one of a phenol resin, an epoxy resin, a petroleum resin, an acrylic resin, a polyethylene resin, a polystyrene resin, a polytetrafluoroethylene, a polyester resin, and a polyamide resin.

Further, the glass particles have a maximum particle diameter of less than 100 μm and a central particle diameter of less than 50 Mm; the oxide and the salt compound have a maximum particle diameter of less than 50 μm and a center particle diameter of less than 25 μm.

Further, the relationship between the softening point TSa of the glass particles and the softening point TSb of the glass or glass ceramic is such that the absolute value of TSb-TSa is not more than 250, and the softening point of the glass particles is 480 to 1100 °C.

Further, the glass particles in the inorganic material have a mass content of 20% or more; the glass particles include silicate glass, phosphate glass, borate glass, aluminate glass, chalcogen compound glass, and citrate At least one of glass and halide glass.

The invention also provides a hot press forming method for glass/glass ceramics, the hot press forming method comprising the following steps:

Coating the high temperature coating described above on at least one side of the glass or the glass ceramic to obtain a coating of the coating and drying;

Performing hot pressing treatment;

The glass or glass ceramic subjected to the hot pressing treatment is placed in a release agent to remove the coating layer.

Further, the temperature of the hot press treatment is 610-850 ° C, the pressure is 0.98 Mpa or less, and the time is 5-300. s.

Further, the coating method is screen printing, blade coating, spin coating, dip coating or spray coating.

Beneficial effect

Compared with the prior art, the present invention has the beneficial effects that the high temperature coating for glass/glass ceramic hot pressing treatment provided by the embodiment of the invention includes organic matter and inorganic matter, and the main function of the organic material is to assist the coating to stably suspend. The dispersion system, in turn, makes the coating application more convenient; the inorganic material has high heat resistance and is used to protect the glass or glass ceramic which is subjected to hot pressing.

Embodiments of the invention

In order to make the objects, technical solutions and advantages of the present invention more comprehensible, the present invention will be further described in detail below with reference to the embodiments. It is understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

A first embodiment of the present invention provides a high temperature coating for a glass/glass ceramic hot press treatment, the high temperature coating comprising an inorganic substance and an organic substance; the inorganic substance comprising at least one amorphous particle, the amorphous particle It is a glass particle; the organic substance includes at least two of a resin, an organic solvent, a coupling agent, a film former, an antifoaming agent, a dispersing agent, a leveling agent, and a photoinitiator.

The high temperature coating for glass/glass ceramic hot pressing treatment provided by the first embodiment of the present invention comprises organic matter and inorganic matter, and the main function of the organic material is to assist the coating stable suspension and dispersion system, thereby further coating coating construction. Convenient; the inorganic material has high heat resistance and is used for protecting glass or glass ceramics which are subjected to hot pressing.

The organic solvent is petroleum ether, benzophenone, acetone, terpineol or alcohol (such as ethanol, isopropanol, etc.);

The coupling agent is titanate, organosilane, triethylamine, methyldiethanolamine;

The film forming agent comprises: a cellulose film forming agent, a protein film forming agent, an acrylic resin film forming agent, a butadiene resin film forming agent, a polyurethane film forming agent, a nitrocellulose film forming agent, or a mutually modified product. Such as carboxymethyl cellulose, methyl cellulose, ethyl cellulose, acrylic resin modified casein film forming agent, acrylic resin polyurethane copolymer resin, polyethylene, acrylate modified butadiene resin, polyurethane modified nitrocellulose Film-forming agent, etc.; film-forming agent plays a decisive role in the performance of the coating, and can form a key material for continuous uniform film coating;

The antifoaming agent is an organosilane or a polysiloxane;

The dispersing agent is BYK-450, a fatty acid, an aliphatic amide, an ester, a paraffin, a metal salt of a higher fatty acid, and a low molecular wax;

The leveling agent is a series of properties of polytetrafluoroethylene, various polyethylene (homopolymer or copolymer), polypropylene, polystyrene or other polymer modified materials as raw materials, which are cracked and oxidized. Different oligomers;

The photoinitiator comprises: a radical polymerization photoinitiator and a cationic polymerization photoinitiator, etc., and the radical photoinitiator can be classified into a pyrolysis photoinitiator and a hydrogen abstraction photoinitiator according to a mechanism of generating a radical. Including: benzoin and derivatives, benzil, alkyl phenones, acyl phosphorus oxides, benzophenones, thioxanthones, etc.; cationic photoinitiators include strontium salts, metal organics Classes, organosilanes, among which are iodonium salts, sulfonium salts and iron aromatic hydrocarbons. The primary purpose of the photoinitiator is to be able to be excited by ultraviolet light to cause the entire printed coating to be cured.

Specifically, the mass ratio of the inorganic substance to the organic substance is 1:0.05-20. Further, the inorganic substance has a mass content of 10% to 95% in the high-temperature paint, and the organic substance has a mass content of not less than 3% in the high-temperature paint. The quality content of the inorganic substance in the high-temperature paint can adjust the construction mode of the paint, the silk screen requires high viscosity, and if the inorganic content is high (the mass ratio of the inorganic substance to the organic substance is 1:0.05-1) Screen printing can be used; spraying requires a lower viscosity ratio, and if the inorganic content is low (the mass ratio of the inorganic substance to the organic substance is 1:2-20), spraying can be used. If the content of the inorganic or organic substance is too low, the corresponding function cannot be obtained, and the corresponding technical effect cannot be obtained.

Specifically, the inorganic substance further includes an oxide having a crystal structure and a salt compound, and the oxide and the salt compound have a melting temperature of more than 630 °C. The oxide and salt compounds are used to adjust the operating temperature of the high temperature coating. The oxide includes at least one of titanium oxide, silicon oxide, aluminum oxide, zirconium oxide, chromium oxide, copper oxide, and iron oxide, and the salt compound includes at least one of magnesium sulfate, barium sulfate, and calcium carbonate. . The oxides and salts have a maximum particle size of 2-10 Mm.

Specifically, the resin includes at least one of a phenol resin, an epoxy resin, a petroleum resin, an acrylic resin, a polyethylene resin, a polystyrene resin, a polytetrafluoroethylene, a polyester resin, and a polyamide resin.

Specifically, the glass particles have a maximum particle diameter of less than 100 μm and a central particle diameter of less than 50 Mm; the oxides and salts have a maximum particle size of less than 50 μm and a central particle size of less than 25 Mm. It has been proved by research that the excessive particle size of the inorganic substance causes a problem of large uneven spots on the surface of the glass after the hot pressing treatment and removal of the protective coating film.

Specifically, the relationship between the softening point TSa of the glass particles and the softening point TSb of the glass or glass ceramic is such that the absolute value of TSb-TSa is not more than 250, and the softening point of the glass particles is 480 to 1100 °C. The softening point of the glass particles can ensure that the high temperature coating can be cured into a film when the glass/glass ceramic is subjected to hot pressing treatment, and still maintains the inherent performance, blocking surface defects from the mold, not only against Glass/glass ceramic protection and contributes to hot pressing of glass/glass ceramics.

Specifically, the glass particles in the inorganic material have a mass content of 20% or more; the glass particles include silicate glass, phosphate glass, borate glass, aluminate glass, chalcogen compound glass, and niobate At least one of glass and halide glass.

A second embodiment of the present invention provides a hot press forming method for a glass/glass ceramic, the hot press forming method comprising the following steps:

Performing hot pressing treatment;

The hot press forming method of the glass/glass ceramic provided by the second embodiment of the present invention is coated with the high temperature coating provided by the first embodiment of the present invention before the hot pressing treatment of the glass/glass ceramic, and the alkaline liquid is directly used after the treatment. Can be removed. The surface of the high temperature coating protective glass/ceramic is hardly changed during the hot pressing process, so that the glass/glass ceramic after the hot pressing treatment does not need to be polished.

Specifically, in the hot pressing treatment, the glass coated with the dried coating layer is placed in a mold, and the upper and lower molds are closed, and then subjected to hot pressing treatment.

Specifically, the mold clamping gap reserved by the upper and lower molds is greater than or equal to the total thickness of the glass and the dry paint coating. The glass is covered with ink on both sides, so the overall thickness of the glass is increased. If the clamping gap is the same as the original glass thickness, the clamping gap is relatively small, which will cause the ink glass to rupture after clamping. Therefore, the clamping gap is greater than or equal to the total thickness of the dried coating and the glass.

Specifically, the material of the upper and lower molds is a ceramic, metal or graphite mold. The ceramic material is at least one of silicon carbide and silicon nitride, and the metal material is at least one of iron, chromium, tungsten, tantalum, molybdenum, titanium or alloy materials thereof.

Specifically, the drying is performed in a temperature environment lower than the hot pressing treatment temperature of the glass or glass ceramic and higher than 80 ° C, and is left until the surface of the coating is dry and tack-free. Preferably, the drying temperature is from 180 to 350 ° C and the drying time is from 8 to 15 minutes. The coating method is screen printing, knife coating, spin coating, dip coating or spray coating.

Specifically, the pH of the release agent may take various values. When the pH of the release agent is greater than or equal to 7, the release agent comprises a surfactant, a penetrating agent, a pH adjuster, an alcohol, and a soap. At least two of a class, an organic base, an inorganic base, a soluble basic compound, a solvent, and water. When the glass/glass ceramic is placed in an alkaline liquid, the surface roughness of the glass/glass ceramic will change significantly, and the surface roughness will increase, and the rise range is 0.01-0.2. Mm. When the pH of the release agent is less than 7, the release agent contains at least two kinds of surfactants, pH adjusters, alcohols, soaps, organic acids, inorganic acids, soluble acidic compounds, solvents, and water.

Specifically, the solvent is an aqueous solvent or an oily solvent. The aqueous solvent includes water, methyl pyrrolidone, terpineol, dipropylene glycol, anisole, dipropylene glycol methyl ether; the oil solvent includes a lower fatty acid butyl ester, castor oil, and a nylon ester.

Specifically, the temperature of the hot pressing treatment is 610-850 ° C, the pressure is less than or equal to 0.98 Mpa, and the time is 5-300. s. The time is related to the pressure, when the pressure is large, the time is short, and the pressure is long. For different glasses, the hot pressing temperature is different. For example, the soda lime silicate glass has a lower softening point and a lower hot pressing temperature of 630-730 ° C; while the high aluminosilicate glass has a higher softening point and a higher hot pressing temperature. To 700-850 ° C. The hot pressing temperature could not be increased and maintained at a level of 700 °C. Mainly because there are two important parameters when hot pressing: temperature and time, because the glass is amorphous material, if the temperature is lower, the time can be extended, or the high temperature can be completed for a short time to complete the same hot press forming.

Specifically, the surfactant is sulfated castor oil, sodium alkylsulfonate, sodium alkylbenzenesulfonate, sodium alkyl sulfate, sodium secondary alkylsulfonate, sodium secondary alkyl sulfate, alpha-olefin Sodium sulfonate , sodium alkylnaphthalene sulfonate, sodium succinate sulfonate, pancreatic bleaching T, sodium sulfamate, fatty alcohol polyoxyethylene ether, alkylphenol ethoxylate, polyether, phosphate compound, And alcohol compounds, ketones, ethers, and the like. The pH adjuster is citric acid, oxalic acid, sorbic acid, sodium hydrogencarbonate, disodium hydrogen phosphate or the like.

Preferably, the release agent is formulated as follows: triethylamine 5-10%, potassium hydroxide 5-20%, sodium dodecylbenzenesulfonate 15-25%, diethanolamine 5-15%, hydrogencarbonate Sodium 5-10%, deionized water 35-60%. The pH is 11-13, the application temperature is 40-80 ° C, and the release time is 5-10 minutes.

The technical solutions of the present invention are further described below in conjunction with the comparative examples and specific embodiments.

Comparative example 1

The glass is hot pressed by a conventional process and then polished on one side 60 Min, the obtained glass product has a bump point of 12%, an indentation of 3%, a scratch of 3%, and a yield of 82%.

Example 1

Preparation of high-temperature coating: The glass 8205 powder, the inorganic particles and the organic solvent are mixed at a mass ratio of 5:2:4, and thoroughly stirred to obtain a high-temperature coating. The inorganic particles are alumina and calcium carbonate mixed in a mass ratio of 7:3; the maximum particle size of the inorganic particles is 2-10 Mm.

The specific process includes:

Preparation of glass 8205 powder:

(1) According to the formula of each raw material content in Fig. 1, weigh the raw materials of each mass ratio, and mix and stir evenly;

(2) Putting into a crucible, heating to 1300 ° C or higher, so that the glass becomes molten;

(3) introducing molten glass into water for quenching to obtain smaller glass particles;

(4) putting the glass particles obtained in the above firing process into a jet mill to be pulverized;

(5) performing gas flow classification to select glass particles having a particle diameter of less than 100 μm;

(6) After mixing with water (mass ratio relationship: glass: water: aqueous solvent (such as ethanol) = 50:25:25, glass: water = 50:50), passed into a bead mill for further grinding and pulverization, to a maximum particle size of less than 50 μm, to obtain an aqueous solution containing glass;

(7) The aqueous solution containing glass was heated to completely evaporate the water to obtain a glass 8205 powder.

The preparation process of the organic solvent is as follows:

Take solvent 340g of terpineol and add 160g C5 modified petroleum resin is fully stirred; 2.4% ethylcellulose N-50 is added with sufficient filling; 3% WinSperse3090 is added to fully stir; SER2035A is added The 3% baking non-silicone defoamer was thoroughly stirred; 8% JL-156 (titanate coupling agent) was added and stirred well to obtain an organic solvent solution.

The hot press forming of glass/glass ceramics is as follows:

Coating the high temperature coating described above on at least one side of the glass to obtain a coating of the coating and drying;

The hot pressing treatment is performed at a temperature of 650 ° C, a pressure of 0.8 MPa, and a time of 230 s;

The hot-pressed glass is placed in a release agent to remove the coating of the coating.

The formulation of the release liquid was: 30 wt% NaHCO ₃ , 70 wt% deionized water, pH 11, operating temperature 80 ° C, and stripping time 10 min.

Single-sided polishing of the stripped glass 15 Min, the final product obtained has a bump point of 4.36%, an indentation of 1.05%, a scratch of 0.88%, and a yield of 91%.

Example 2

Preparation of high-temperature coating: The glass 9205 powder, the inorganic particles and the organic solvent are mixed at a mass ratio of 5:5:4, and thoroughly stirred to obtain a high-temperature coating. The inorganic particles are mixed with barium sulfate, chromium oxide and silicon oxide in a mass ratio of 4:1:5; the maximum particle size of the inorganic particles is 2-10 Mm.

The specific process includes:

Preparation of glass 9205 powder:

(1) According to the formula of each raw material content in Fig. 2, weigh the raw materials of each mass ratio, and mix and stir evenly;

(7) The aqueous solution containing glass was heated to completely evaporate the water to obtain a glass 9205 powder.

The preparation process of the organic solvent is as follows:

The hot press forming of glass/glass ceramics is as follows:

The hot pressing treatment is performed at a temperature of 700 ° C, a pressure of 0.9 MPa, and a time of 100 s;

The formulation of the mold release liquid is: 15 wt% inorganic base is KOH, 10 wt% sodium dodecylbenzenesulfonate, 7 wt% diethanolamine, 5 wt% triethylamine, 63 wt% solvent is deionized water, pH is 13 , working temperature is 40 ° C, stripping time is 5 Min.

Single-sided polishing of the stripped glass 20 Min, the final product obtained has a bump point of 4.36%, an indentation of 1.05%, a scratch of 0.88%, and a yield of 100%.

Example 3

Preparation of high-temperature coating: The glass 6205 powder, the inorganic particles and the organic solvent are mixed at a mass ratio of 5:8:4, and thoroughly stirred to obtain a high-temperature coating. The inorganic particles are alumina, zirconia, magnesium sulfate, mixed in a mass ratio of 1:6:3; the maximum particle size of the inorganic particles is 2-10 Mm.

The specific process includes:

Preparation of glass 6205 powder:

(1) According to the formula of each raw material content in Fig. 3, weigh the raw materials of each mass ratio, and mix and stir evenly;

(7) The aqueous solution containing glass was heated to completely evaporate the water to obtain a glass 6205 powder.

The preparation process of the organic solvent is as follows:

Take 340 g of solvent terpineol, add 160g of C ₅ modified petroleum resin and stir well; add 2.4% of ethyl cellulose N-50 to fully stir; add 3% WinSperse3090 to fully stir; add SER2035A 3% baking varnish non-silicon The foaming agent was thoroughly stirred; 8% JL-156 (titanate coupling agent) was added and stirred well to obtain an organic solvent solution.

The hot press forming of glass/glass ceramics is as follows:

The hot pressing treatment is performed at a temperature of 850 ° C, a pressure of 0.98 MPa, and a time of 5 s;

The formulation of the mold release liquid is: 20wt% inorganic alkali NaOH, 5wt% triethylamine, 75wt% solvent deionized water, pH 12, working temperature is 60 ° C, and the stripping time is 8 Min.

Single-sided polishing of the stripped glass 10 Min, the final product obtained has a bump of 2.36%, an indentation of 3.09%, a scratch of 1.75%, and a yield of 98%.

The above is only the preferred embodiment of the present invention, and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection of the present invention. Within the scope.

Claims

A high temperature coating for glass/glass ceramic hot press treatment, characterized in that the high temperature coating comprises inorganic substances and organic substances; the inorganic substance comprises at least one amorphous particle, and the amorphous particles are glass particles; The organic substance includes at least two of a resin, an organic solvent, a coupling agent, a film former, an antifoaming agent, a dispersing agent, a leveling agent, and a photoinitiator.
The high temperature coating according to claim 1, wherein the mass ratio of the inorganic substance to the organic substance is 1: 0.05-20.
The high temperature coating according to claim 1, wherein the inorganic substance further comprises an oxide having a crystal structure and a salt compound, and the oxide and the salt compound have a melting temperature of more than 630 °C.
The high temperature coating according to claim 1, wherein said resin comprises phenol resin, epoxy resin, petroleum resin, acrylic resin, polyethylene resin, polystyrene resin, polytetrafluoroethylene, polyester resin, poly At least one of amide resins.
The high temperature coating according to claim 3, wherein said glass particles have a maximum particle diameter of less than 100 μm and a center particle diameter of less than 50 Mm; the oxide and the salt compound have a maximum particle diameter of less than 50 μm and a center particle diameter of less than 25 μm.
The high temperature coating according to claim 1, wherein a relationship between a softening point TSa of the glass particles and a softening point TSb of the glass or glass ceramic is: an absolute value of TSb-TSa of not more than 250, the glass The softening point of the granules is 480-1100 °C.
The high temperature coating according to claim 1, wherein the inorganic material has a glass particle mass content of 20% or more; and the glass particles comprise silicate glass, phosphate glass, borate glass, and alumina acid. At least one of salt glass, chalcogen compound glass, silicate glass, and halide glass.
A glass/glass ceramic hot press forming method, characterized in that the hot press forming method comprises the following steps:

Coating the high temperature coating according to any one of claims 1 to 7 on at least one side of the glass or the glass ceramic to obtain a coating of the coating and drying;

Performing hot pressing treatment;

The glass or glass ceramic subjected to the hot pressing treatment is placed in a release agent to remove the coating layer.
The hot press forming method according to claim 8, wherein the hot pressing treatment has a temperature of 610 to 850 ° C and a pressure of 0.98 or less. Mpa, the time is 5-300 s.
The hot press forming method according to claim 8, wherein the coating is performed by screen printing, blade coating, spin coating, dip coating or spray coating.