阅读说明：本技术 复合涂层及制备方法、超薄玻璃及制备方法、终端设备 (Composite coating and preparation method thereof, ultrathin glass and preparation method thereof, and terminal equipment ) 是由 韦新颖 高尚 詹勇军 朱波 张磊 尹智 谭伟 苟洁 郑寒颖 于 2021-09-17 设计创作，主要内容包括：本发明提供一种复合涂层及制备方法、超薄玻璃及制备方法、终端设备,复合涂层包括依次涂布于超薄玻璃基片表面的耐冲击涂层和自修复功能层；所述耐冲击涂层包括主体树脂、固化剂、催化剂；所述自修复功能层由自愈合聚氨酯基树脂、丙烯酸酯基树脂、环氧基树脂和有机硅树脂中的任意一种或多种。通过耐冲击涂层的改性优化,增强了它在超薄玻璃基片表面的附着性能,并且在进行耐冲击涂层、自修复性涂层结构厚度调整的过程中,有效规避了超薄玻璃基片翘曲、脱膜等缺陷,另外,耐冲击性涂层的刚性结构的组配也大幅度提升了复合涂层的耐冲击性能,有利于扩展超薄玻璃基片的在可柔性、可折叠产品中的应用。(The invention provides a composite coating and a preparation method thereof, ultrathin glass and a preparation method thereof, and terminal equipment, wherein the composite coating comprises an impact-resistant coating and a self-repairing functional layer which are sequentially coated on the surface of an ultrathin glass substrate; the impact-resistant coating comprises main resin, a curing agent and a catalyst; the self-repairing functional layer is made of any one or more of self-repairing polyurethane-based resin, acrylate-based resin, epoxy resin and organic silicon resin. The adhesion performance of the impact-resistant coating on the surface of the ultrathin glass substrate is enhanced through the modification optimization of the impact-resistant coating, the defects of warping, demoulding and the like of the ultrathin glass substrate are effectively avoided in the process of adjusting the thicknesses of the impact-resistant coating and the self-repairing coating, in addition, the impact resistance of the composite coating is greatly improved through the combination of the rigid structure of the impact-resistant coating, and the application of the ultrathin glass substrate in flexible and foldable products is favorably expanded.)

1. A composite coating is characterized by comprising an impact-resistant coating and a self-repairing functional layer which are sequentially coated on the surface of an ultrathin glass substrate;

the impact-resistant coating comprises main resin, a curing agent and a catalyst;

the self-repairing functional layer is made of any one or more of self-repairing polyurethane-based resin, acrylate-based resin, epoxy resin and organic silicon resin.

2. The composite coating according to claim 1, wherein the impact-resistant coating comprises the following components in parts by mass: 60-130 parts of main resin, 15-45 parts of curing agent and 0.5-5 parts of catalyst.

3. The composite coating of claim 1, wherein the impact-resistant coating further comprises 0.5-5 parts of a leveling agent;

the leveling agent comprises one or more of an organic silicon leveling agent, a non-silicon leveling agent and a fluorine-containing leveling agent.

4. The composite coating of claim 1, wherein the impact-resistant coating further comprises 0.5 to 5 parts of a coupling agent;

the coupling agent comprises one or more of gamma-aminopropyltriethoxysilane, gamma- (2, 3-epoxypropoxy) propyltrimethoxysilane), R-mercaptopropyltriethoxysilane and isopropyltris (dioctyl pyrophosphato-oxy) titanate.

5. The composite coating of claim 1, wherein the host resin is one or more of an alicyclic polyester polyol, an epoxy modified acrylic resin.

6. The composite coating of claim 1, wherein the curing agent comprises one or more of melamine formaldehyde resin, hexamethylene diisocyanate trimer, toluene diisocyanate, diphenylmethane diisocyanate, dicyclohexylmethane diisocyanate, polyetheramine I.

7. The composite coating of claim 1, wherein the catalyst comprises one or more of organotin, triethylamine, organobismuth, p-toluenesulfonic acid, dimethylbenzylamine.

8. The composite coating of claim 1, wherein the impact-resistant coating further comprises a solvent, and the solvent is used for the impact-resistant coating, wherein the mass ratio of each component of the solvent in the impact-resistant coating is 80-160 parts;

the solvent comprises one or more of butyl ester, ethyl ester, cyclohexanone, isopropanol, diacetone alcohol, xylene, benzyl alcohol and methyl isobutyl ketone.

9. The composite coating of claim 1, wherein the self-healing functional layer has a thickness of 10-50 μ ι η.

10. A method of preparing a composite coating, comprising:

step 1, uniformly mixing 60-130 parts of main resin, 15-45 parts of curing agent, 0.5-5 parts of catalyst and 80-160 parts of solvent according to the mass ratio to form impact-resistant coating slurry with coatability;

step 2, coating the impact-resistant coating slurry on the surface of the ultrathin glass substrate, and pre-curing the coated ultrathin glass substrate so as to volatilize the solvent in the impact-resistant coating slurry;

and 3, using any one or more of self-healing polyurethane-based resin, acrylate-based resin, epoxy-based resin and organic silicon resin as a self-healing functional coating, coating the self-healing functional coating on the surface of the impact-resistant coating, and baking and curing the self-healing polyurethane-based resin, acrylate-based resin, epoxy-based resin and organic silicon resin.

11. The method according to claim 10, wherein in the step 2, the curing temperature is 150 ℃ or less, and the heat treatment time is less than 1 hour.

12. The method according to claim 10, wherein in the step 3, the curing temperature is 120 ℃ and the curing time is 1 hour.

13. The method of claim 10, wherein the impact-resistant coating further comprises 0.5-5 parts of a leveling agent and/or 0.5-5 parts of a coupling agent.

14. A method for producing ultra-thin glass, characterized in that the composite coating according to any of claims 1 to 9 is applied, said method comprising:

coating an impact-resistant coating on the cleaned ultrathin glass substrate, and carrying out heat treatment;

and coating a self-repairing functional layer on the surface of the impact-resistant coating after heat treatment, and performing thermosetting or ultraviolet curing.

15. The method according to claim 14, wherein the heat curing temperature is 150 ℃ or less, the time is 1 hour, and the ultraviolet ray is appliedLight energy is more than or equal to 450mJ/cm²。

16. An ultra-thin glass, comprising: an ultra-thin glass substrate further comprising a composite coating as claimed in any one of claims 1 to 9.

17. The ultra-thin glass of claim 16, further comprising a coupling agent layer disposed between the impact-resistant coating and the ultra-thin glass substrate;

the coupling agent layer is one or more of gamma-aminopropyltriethoxysilane, gamma- (2, 3-epoxypropoxy) propyltrimethoxysilane), R-mercaptopropyltriethoxysilane and isopropyl tri (dioctyl pyrophosphato acyloxy) titanate, wherein the coupling agent layer is added in a mass ratio of 0.5-5 parts.

18. The ultra-thin glass of claim 16, wherein a coupling agent is further added to the impact-resistant coating, wherein the coupling agent is one or more of gamma-aminopropyltriethoxysilane, gamma- (2, 3-glycidoxy) propyltrimethoxysilane), R-mercaptopropyltriethoxysilane, and isopropyltris (dioctylpyrophosphate) titanate, and wherein the coupling agent is added in a ratio of 0.5 to 5 parts by mass.

19. A terminal device comprising a device case and a screen, the screen comprising the ultra-thin glass of claim 16.

Technical Field

The invention relates to the field of flexible display panels, in particular to a composite coating and a preparation method thereof, ultrathin glass and a preparation method thereof, and terminal equipment.

Background

With the development of display technology, the application field of display devices is very wide, the requirements for various performances of a screen body are gradually increased, and with the expansion of application scenes, the flexible display panel of the ultrathin glass substrate can be applied to foldable mobile phones, notebook computers, various curled display devices and the like. Although the ultra-thin glass substrate has the advantages of excellent touch, the impact resistance is relatively poor, and the pen and ball dropping performance is obviously reduced along with the reduction of the thickness of the ultra-thin glass substrate.

In view of the above disadvantages, there is a foldable mobile phone that uses a light-colored polyimide resin as a flexible protective cover to enhance the toughness of the cover; there is also a method of attaching a protective film such as a light-colored polyimide film or polyethylene terephthalate to an ultrathin glass surface or an ultrathin glass surface having a coating, and the protective film surface has a hardening functional coating. Such applications have two problems, first of all, that is, a case where a plastic substrate such as a light-colored polyimide film or polyethylene terephthalate is fatigued after being bent several times, and that unrecoverable creases occur, and finally, the touch and visual appearance of the screen are greatly impaired. Secondly, if the coated ultrathin glass needs to be laminated with a surface plastic protective film, the advantages of the ultrathin glass coating process route are difficult to exert, the waste of the process and the increase of the cost are caused, and the total thickness of the screen is increased due to the arrangement of the polyethylene terephthalate protective film and the related optical pressure-sensitive adhesive, so that the use of the foldable film is not facilitated.

Therefore, how to improve the mechanical properties of the ultra-thin glass is a problem to be solved at present.

Disclosure of Invention

The invention aims to provide a composite coating and a preparation method thereof, ultrathin glass and a preparation method thereof, and terminal equipment, so as to improve the mechanical property and the chemical property of the ultrathin glass.

The invention provides a composite coating, which comprises an impact-resistant coating and a self-repairing functional layer which are sequentially coated on the surface of an ultrathin glass substrate;

the impact-resistant coating comprises main resin, a curing agent and a catalyst;

the self-repairing functional layer is made of any one or more of self-repairing polyurethane-based resin, acrylate-based resin, epoxy resin and organic silicon resin.

As a preferred technical scheme, the impact-resistant coating comprises the following components in percentage by mass: 60-130 parts of main resin, 15-45 parts of curing agent and 0.5-5 parts of catalyst.

As a preferable technical scheme, the impact-resistant coating further comprises 0.5-5 parts of a leveling agent;

the leveling agent comprises one or more of an organic silicon leveling agent, a non-silicon leveling agent and a fluorine-containing leveling agent.

As a preferred technical scheme, the impact-resistant coating also comprises 0.5-5 parts of a coupling agent;

the coupling agent comprises one or more of gamma-aminopropyltriethoxysilane, gamma- (2, 3-epoxypropoxy) propyltrimethoxysilane), R-mercaptopropyltriethoxysilane and isopropyltris (dioctyl pyrophosphato-oxy) titanate.

Preferably, the host resin is one or more of alicyclic polyester polyol and epoxy resin modified acrylic resin.

The composite coating of claim 1, wherein the curing agent comprises one or more of melamine formaldehyde resin, hexamethylene diisocyanate trimer, toluene diisocyanate, diphenylmethane diisocyanate, dicyclohexylmethane diisocyanate, polyetheramine I.

As a preferable technical scheme, the catalyst comprises one or more of organic tin, triethylamine, organic bismuth, p-toluenesulfonic acid and dimethylbenzylamine.

As a preferable technical scheme, the impact-resistant coating further comprises a solvent, wherein the solvent accounts for 80-160 parts of the impact-resistant coating by mass; the solvent comprises one or more of butyl ester, ethyl ester, cyclohexanone, isopropanol, diacetone alcohol, xylene, benzyl alcohol and methyl isobutyl ketone.

As a preferable technical scheme, the thickness of the self-repairing functional layer is 10-50 μm.

Also provided is a method for preparing a composite coating, comprising:

step 1, uniformly mixing 60-130 parts of main resin, 15-45 parts of curing agent, 0.5-5 parts of catalyst and 80-160 parts of solvent according to the mass ratio to form impact-resistant coating slurry with coatability;

step 2, coating the impact-resistant coating slurry on the surface of a substrate, and pre-curing the coated substrate so as to volatilize an organic solvent in the impact-resistant coating slurry;

and 3, selecting any one or more of self-healing polyurethane-based resin, acrylate-based resin, epoxy-based resin and organic silicon resin as a functional coating, coating the functional coating on the surface of the impact-resistant coating, and baking and curing.

Preferably, in the step 2, the curing temperature is not higher than 150 ℃, and the heat treatment time is less than 1 hour.

In a preferred embodiment, in step 3, the curing temperature is 120 ℃, and the curing time is 1 hour.

As a preferable technical scheme, the impact-resistant coating further comprises 0.5-5 parts of a leveling agent and/or 0.5-5 parts of a coupling agent.

Also provided is a method for preparing ultrathin glass by applying the composite coating, wherein the preparation method comprises the following steps:

coating an impact-resistant coating on the cleaned ultrathin glass substrate, and carrying out heat treatment;

and coating a self-repairing functional layer on the surface of the impact-resistant coating after heat treatment, and performing thermosetting or ultraviolet curing.

As a preferred technical scheme, the heat curing temperature is less than or equal to 150 ℃, the time is 1 hour, and the ultraviolet energy is more than or equal to 450mJ/cm²。

Also provided is an ultra-thin glass comprising: an ultra-thin glass substrate further comprising a composite coating as described above.

In a preferred embodiment, the ultra-thin glass further comprises a coupling agent layer disposed between the impact-resistant coating and the ultra-thin glass substrate;

the coupling agent layer is one or more of gamma-aminopropyltriethoxysilane, gamma- (2, 3-epoxypropoxy) propyltrimethoxysilane), R-mercaptopropyltriethoxysilane and isopropyl tri (dioctyl pyrophosphato acyloxy) titanate, wherein the coupling agent layer is added in a mass ratio of 0.5-5 parts.

As a preferable technical scheme, a coupling agent is also added into the impact-resistant coating, the coupling agent is one or more of gamma-aminopropyl triethoxysilane, gamma- (2, 3-epoxypropoxy) propyl trimethoxysilane), R-mercaptopropyl triethoxysilane and isopropyl tri (dioctyl pyrophosphato acyloxy) titanate, wherein the adding proportion of the coupling agent is 0.5-5 parts by mass.

Also provided is a terminal device comprising a device housing and a screen, wherein the screen comprises the ultra-thin glass.

In conclusion, the composite coating is coated on the surface of the ultrathin glass substrate to sequentially form the ultrathin glass, the impact-resistant coating and the self-repairing coating, the adhesion performance of the composite coating on the interface of the ultrathin glass substrate is enhanced through the modification optimization of the impact-resistant coating, the defects of warping, demoulding and the like of the ultrathin glass substrate are effectively avoided in the process of adjusting the thicknesses of the impact-resistant coating and the self-repairing coating, in addition, the impact resistance of the composite coating is greatly improved due to the rigid structure of the impact-resistant coating, and the application of the ultrathin glass substrate in flexible and foldable products is favorably expanded.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention, and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

FIG. 1 is a flow chart of a method of making a composite coating of example two;

FIG. 2 is a SEM image of a cross-section of the coating of the first embodiment of the second embodiment;

FIG. 3 is a SEM image of a cross-section of a coating of a second embodiment of the second example;

FIG. 4 is a SEM image of a cross-section of a coating of a third embodiment of example two;

FIG. 5 is a flow chart of a method of making ultra-thin glass according to example III.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example one

The present invention provides a composite coating, which includes an impact-resistant coating and a self-repairing functional layer sequentially coated on a surface of an ultra-thin glass substrate.

The impact-resistant coating comprises main resin, a curing agent and a catalyst; wherein the mass ratio of each component is as follows: 60-130 parts of main resin, 15-45 parts of curing agent and 0.5-5 parts of catalyst.

Wherein in order to further improve the better adhesion performance of the impact-resistant coating and the ultrathin glass substrate, as a preferred technical scheme, the impact-resistant coating also comprises 0.5-5 parts of a coupling agent; in view of the control of the apparent quality in the actual construction process, 0.5-5 parts of leveling agent can be added into the impact-resistant coating.

Preferably, the host resin is one or more of alicyclic polyester polyol and epoxy resin modified acrylic resin. The alicyclic polyester polyol has strong ester bond impact resistance, the cyclic structure can greatly improve the elastic modulus, the molecules are linear structures and have good flexibility, hydroxyl and carboxyl are reserved at two ends and can react with various curing agents, the acrylic resin of the epoxy resin modified acrylic resin has more polar groups in the molecules with the epoxy resin, the glass adhesion is good, the acrylic resin provides flexibility, the glass adhesion is strong, the elastic modulus is high, but the flexibility is insufficient, and the long-chain polyether amine is used as the curing agent to greatly improve the flexibility of the epoxy resin and meet the bending requirement.

Curing agent: melamine formaldehyde resin, one or more of hexamethylene diisocyanate trimer, toluene diisocyanate, diphenylmethane diisocyanate, dicyclohexylmethane diisocyanate and polyether amine I.

Catalyst: one or more of organic tin, triethylamine, organic bismuth, p-toluenesulfonic acid and dimethylbenzylamine.

Preferably, the impact-resistant coating further comprises a solvent, wherein the solvent accounts for 80-160 parts of the impact-resistant coating by mass; solvent: one or more of butyl ester, ethyl ester, cyclohexanone, isopropanol, diacetone alcohol, xylene, benzyl alcohol and methyl isobutyl ketone. It should be noted that, in the manufacturing process, the impact-resistant coating slurry mixed with the solvent is coated on the surface of the ultrathin glass substrate, and the coated ultrathin glass substrate is pre-cured, so as to volatilize the solvent in the impact-resistant coating slurry, and the solvent is preferably completely volatilized to avoid appearance defects.

The main purpose in the technical scheme is to improve the pen-dropping performance through the modification of composite coating materials such as impact resistance and the like and the optimization of the structure, and the key point is that the impact-resistant coating and the self-repairing functional layer can form a thickness, so that the adhesiveness of the impact-resistant coating and the self-repairing functional layer is good, and the impact-resistant coating and the self-repairing functional layer can be formed on a composite coating product with almost no warping appearance.

Compared with the prior art, a polymer material such as polyamic acid, low-temperature transparent polyimide and the like is generally used as a coating layer, and in combination with the improvement of impact resistance performance such as pen drop performance, the most convenient way is to increase the thickness of the coating layer to improve the impact resistance. However, since the coating layer is thickened, the adhesion of the coating material is not firm, and thus, in the actual construction coating process, the coating layer may be poorly adhered due to the increased thickness, and the coating layer may be peeled off in a serious case. One advantage of the technical scheme is that the coating is thickened and simultaneously has good adhesion performance and boiling resistance through modification of the coating material. The thickness of the impact-resistant coating in the technical scheme can be 5-60 mu m thick, the thickness can be further 10-60 mu m thick, and after the thickness of the coating is increased, the edge of the coating is warped, for example, the edge of the coating with the thickness of 70mm is warped by less than or equal to 2 mm.

Further, in order to enhance the boiling resistance, since the composite coating on the ultra-thin glass substrate needs to be subjected to high temperature and high humidity, dynamic/static bending and other confidence resistance tests, a coupling agent layer can be arranged between the impact-resistant coating and the ultra-thin glass substrate, and in this way, a coupling agent does not need to be added into the impact-resistant coating. The coupling agent layer comprises one or more of gamma-aminopropyltriethoxysilane, gamma- (2, 3-epoxypropoxy) propyltrimethoxysilane), R-mercaptopropyltriethoxysilane and isopropyl tri (dioctyl pyrophosphato acyloxy) titanate, wherein the addition ratio is 0.5-5 parts by mass, and preferably, the gamma-aminopropyltriethoxysilane can be selected to enhance the adhesion property of the coating interface.

Considering that in the application of flexible display panel, the appearance of the composite coating is very concerned, especially the integral flatness of the coating, for this reason, 0.5-5 parts by mass of leveling agent is added into the composite solution in the process of preparing the impact-resistant coating solution, wherein the leveling agent comprises one or more of organosilicon leveling agent, non-silicon leveling agent and fluorine-containing leveling agent.

In order to realize better pen-dropping performance, the key point is that the characteristics of the impact-resistant coating material can be improved on the aspect of increasing the thickness of the impact-resistant coating as an improvement effect, the tensile strength of the impact-resistant coating in the technical scheme is 10-200MPa, the elongation at break is 10% -80%, and the material can be directly attached to the surface of ultrathin glass and can also be well attached to the surface of an amino coupling agent coating.

The self-repairing functional layer in the scheme is prepared by mixing any one or more of self-repairing polyurethane-based resin, acrylate-based resin, epoxy-based resin and organic silicon resin, and the thickness of the self-repairing functional layer is controlled to be 10-50 mu m, and more preferably 20-40 mu m.

The main purpose of the scheme is to improve the pen dropping performance by conforming to the coating modification and structure optimization design so as to better adapt to multi-scene application, the pen dropping performance of the composite coating can reach 40mm at the lowest, and can reach 105mm at the highest along with the optimization of the thickness of the coating, and the minimum bending radius R of the composite coating can reach 0.8mm under the condition, and the composite coating is not damaged after being bent for 200000 times;

in order to better adapt to various confidence tolerance tests, the composite coating optimally designed by the technical scheme is subjected to a hundred-grid test after being boiled in water at 95 ℃ for 1 hour, and the adhesion performance grade is more than or equal to 5B.

Further this technical scheme adopts the scheme that ultra-thin glass substrate surface was filmed in order to strengthen the performance of falling a writing, and its reinforcing still keeps lower resilience force when falling a writing performance, can reach 1.5N at minimum, and the resilience force reduces and is favorable to increasing the laminating of display module and the maintenance of adhesion performance in the display screen.

Example two

This example provides a method for preparing a composite coating layer, which is used to prepare the composite coating layer in the first example, as shown in fig. 1, and includes the steps of:

step 1, uniformly mixing 60-130 parts of main resin, 15-45 parts of curing agent, 0.5-5 parts of catalyst and 80-160 parts of solvent according to the mass ratio to form impact-resistant coating slurry with coatability;

step 2, coating the impact-resistant coating slurry on the surface of a substrate, and pre-curing the coated substrate so as to volatilize an organic solvent in the impact-resistant coating slurry;

and 3, selecting any one or more of self-healing polyurethane-based resin, acrylate-based resin, epoxy-based resin and organic silicon resin as a self-healing functional coating, coating the self-healing functional coating on the surface of the impact-resistant coating, and baking and curing the self-healing polyurethane-based resin, the acrylate-based resin, the epoxy-based resin and the organic silicon resin.

Preferably, in the step 2, the curing temperature is not higher than 150 ℃, and the heat treatment time is less than 1 hour.

In a preferred embodiment, in step 3, the curing temperature is 120 ℃, and the curing time is 1 hour.

As a preferable technical scheme, the impact-resistant coating further comprises 0.5-5 parts of a leveling agent and/or 0.5-5 parts of a coupling agent.

In actual production, this example gives the following 3 embodiments:

in the first embodiment, the impact-resistant coating layer is disposed by taking the following main resin: 60 parts of alicyclic polyester polyol, 15 parts of amino 325 resin, 0.5 part of paratoluenesulfonic acid catalyst, 40 parts of solvent butyl ester and 40 parts of methyl isobutyl ketone are fully mixed to form the impact-resistant coating slurry with coatability.

Selecting an ultrathin glass substrate with the thickness of 30 microns, coating after surface cleaning, coating an impact-resistant coating in a spraying mode, and then pre-curing the coated substrate to volatilize an organic solvent, wherein the curing temperature is 150 ℃, the heat treatment time is 1 hour, and the dry film thickness of the impact-resistant coating is finally 14.5 microns.

And then spraying a self-repairing functional coating on the surface of the impact-resistant coating, selecting acrylate-based resin for coating, baking and curing at the temperature of 120 ℃ for 1 hour, and finally forming a coating with the dry film thickness of 23.5 mu m, wherein an SEM picture of the section of the coating is shown in figure 2.

And then, carrying out bending test and pen drop performance test on the coated substrate, wherein the bending is realized at R0.8mm, the substrate is not damaged after 200K times, and the pen drop performance test is carried out, and the pen drop height reaches 40 mm.

In a second embodiment, regarding the disposition of the impact-resistant coating, 130 parts of a main resin epoxy-modified acrylic resin, 45 parts of a hexamethylene diisocyanate trimer curing agent, 5 parts of an organotin catalyst, 80 parts of a solvent methyl isobutyl ketone and 80 parts of ethylene glycol ethyl ether acetate are thoroughly mixed, and 0.5 part of a coupling agent is further added to form an impact-resistant coating slurry having coatability.

A30-micron ultrathin glass substrate is selected, the surface of the ultrathin glass substrate is cleaned and then coated, a coupling agent is sprayed at first, the concentration of the coupling agent is 2%, and the ultrathin glass substrate is baked for 15 minutes at 90 ℃ after being sprayed.

And (3) coating an impact-resistant coating on the surface of the coupling agent by adopting a spraying mode, then pre-curing the coated substrate to volatilize the organic solvent, wherein the curing temperature is 100 ℃, the heat treatment time is 1 hour, and finally the dry film thickness of the impact-resistant coating is 28 microns.

And then spraying a self-repairing functional coating on the surface of the impact-resistant coating, selecting self-healing polyurethane-based resin for coating, then baking and curing at the temperature of 120 ℃ for 1 hour, and finally forming a coating with the dry film thickness of about 25.5 mu m, wherein the SEM picture of the section of the coating is shown in figure 3.

And then, carrying out bending test and pen-dropping performance test on the coated substrate, wherein the bending is realized at R1.5mm, the substrate is not damaged after 200K, and the structure shown in figure 4 is formed in sequence for testing the pen-dropping performance, and the pen-dropping height reaches 105 mm.

In a third embodiment, regarding the configuration of the impact-resistant coating, 85 parts of main resin hydrogenated epoxy resin, 30 parts of polyetheramine curing agent, 2 parts of triethylamine catalyst, 80 parts of solvent xylene and 80 parts of benzyl alcohol are respectively taken and fully mixed, 5 parts of coupling agent is further added, 0.5 part of organic silicon leveling agent is further added, and the materials are fully mixed to form the impact-resistant coating slurry with coatability.

Selecting an ultrathin glass substrate with the thickness of 30 micrometers, cleaning the surface of the ultrathin glass substrate, coating a film, firstly coating an impact-resistant coating in a spraying mode, then pre-curing the coated substrate to volatilize an organic solvent, wherein the curing temperature is 120 ℃, the heat treatment time is 30 minutes, and finally the dry film thickness of the impact-resistant coating is 25 micrometers.

And then spraying a self-repairing functional coating on the surface of the impact-resistant coating, selecting self-healing polyurethane-based resin for coating, then baking and curing at the temperature of 80 ℃ for 2 hours, and finally forming a coating with the dry film thickness of about 14 mu m, wherein an SEM picture of the section of the coating is shown in figure 4.

And then, carrying out bending test and pen drop performance test on the coated substrate, wherein the substrate is bent to realize R1mm, and is not damaged after 200K times, and the pen drop performance test is carried out, wherein the pen drop height reaches 75 mm.

In the embodiment, the adhesive property and the boiling resistance of the coating layer of the coupling agent are improved, and the adhesion property grade of a Baige test after boiling for 1 hour at 95 ℃ is 5B.

EXAMPLE III

This example provides a method for preparing ultra-thin glass, applying the composite coating as described above, as shown in fig. 5, the method includes:

coating an impact-resistant coating on the cleaned ultrathin glass substrate, and carrying out heat treatment;

and coating a self-repairing functional layer on the surface of the impact-resistant coating after heat treatment, and performing thermosetting or ultraviolet curing.

As a preferred technical scheme, the heat curing temperature is less than or equal to 150 ℃, the time is 1 hour, and the ultraviolet energy is more than or equal to 450mJ/cm²。

The impact-resistant coating and the self-repairing functional layer in the technical scheme can be finished by adopting construction modes such as slit coating, spraying, rotary coating, blade coating and the like; the impact resistant coating has the advantage that the thermal curing process can be performed at a lower temperature than the relevant material (e.g. polyamic acid material).

Example four

The embodiment provides the ultrathin glass, which comprises an ultrathin glass substrate and the composite coating in the first embodiment.

As a preferred embodiment, the ultra-thin glass may further include a coupling agent layer disposed between the impact-resistant coating and the ultra-thin glass substrate; the coupling agent layer is one or more of gamma-aminopropyltriethoxysilane, gamma- (2, 3-epoxypropoxy) propyltrimethoxysilane), R-mercaptopropyltriethoxysilane and isopropyl tri (dioctyl pyrophosphato acyloxy) titanate, wherein the coupling agent layer is added in a mass ratio of 0.5-5 parts. In this embodiment, by applying the coupling agent layer, compared with the third mode in the second embodiment, γ - (2, 3-glycidoxy) propyl trimethoxysilane is selected as the coupling agent layer in this embodiment, that is, firstly, the coupling agent is coated on the surface of the ultrathin glass substrate, baking curing is performed at 80-140 ℃ for 2-10 minutes, and then, the impact-resistant coating and the self-repairing functional layer are sequentially plated, the cross-sectional thickness of the formed coating is 37 μm for the impact-resistant coating, 21 μm for the self-repairing functional layer, the water boiling resistance is further improved, and the grade of the adhesive force performance after 1 hour boiling at 95 ℃ is 5B in the hectogram test. The bending direction R1.0 is normal at 200K, and the pen falling performance is improved to 15 cm.

Of course, another preferred embodiment is that a coupling agent is further added into the impact-resistant coating, wherein the coupling agent is one or more of gamma-aminopropyltriethoxysilane, gamma- (2, 3-epoxypropoxy) propyltrimethoxysilane), R-mercaptopropyltriethoxysilane, and isopropyl tri (dioctyl pyrophosphato-oxy) titanate, and the coupling agent is added in a mass ratio of 0.5-5 parts.

EXAMPLE five

The embodiment provides a terminal device, which comprises a device shell and a screen, wherein the screen comprises the ultrathin glass in the third embodiment.

In conclusion, the composite coating is coated on the surface of the ultrathin glass substrate to sequentially form the ultrathin glass, the impact-resistant coating and the self-repairing coating, the adhesion performance of the composite coating on the interface of the ultrathin glass substrate is enhanced through the modification optimization of the impact-resistant coating, the defects of warping, demoulding and the like of the ultrathin glass substrate are effectively avoided in the process of adjusting the thicknesses of the impact-resistant coating and the self-repairing coating, in addition, the impact resistance of the composite coating is greatly improved due to the rigid structure of the impact-resistant coating, and the application of the ultrathin glass substrate in flexible and foldable products is favorably expanded.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.