Composite coating coated on surface of ultrathin flexible glass and glass cover plate

Abstract

The invention provides a composite coating coated on the surface of ultrathin flexible glass. The composite coating comprises a composite buffer layer and a hardened layer, wherein the hardened layer material comprises functional resin, a photoinitiator and a solvent; the composite buffer layer material comprises functional resin, a resin monomer, an active monomer, a photoinitiator and a solvent. The invention also provides a glass cover plate. The glass cover plate comprises ultrathin flexible glass and a composite coating coated on the surface of the ultrathin flexible glass, the composite buffer layer in the composite coating covers the surface of the flexible glass. Through the design of the coating structure and the components, compared with a multi-layer structure, the number of layers of the coating is reduced, the shrinkage rate of the coating can be reduced, and the mechanical property of the product is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of ultra-thin flexible glass, and in particular relates to a composite coating and a glass cover plate coated on the surface of ultra-thin flexible glass. Background Art

[0002] With the development of electronic technology, display technology has also developed accordingly. Display devices have a wide range of applications. In pursuit of ultra-thin and lightweight electronic products and ultra-thin, flexible and foldable electronic products, the display devices of electronic devices must first be ultra-thin and lightweight. Ultra-thin flexible glass can be ultra-thin and flexible. The advantages of UTG are: 1) High transmittance: UTG is based on the characteristics of glass, with a transmittance of more than 90%; 2) Strong durability: UTG material is durable, not easily damaged or scratched after bending, and has a better touch; 3) Better high temperature resistance.

[0003] However, due to the thinness of the overall thickness of the glass, its strength is difficult to meet the industry's usage requirements; at the same time, due to the brittleness of tempered glass itself, UTG has low strength and poor impact resistance, and is easy to shatter after breaking, which is harmful to the human body. Therefore, it is necessary to coat the surface of UTG to make it have high impact resistance. At present, the preparation method of high-impact ultra-thin flexible glass cover is mainly to coat the functional coating on UTG to make it have excellent impact resistance and fatigue resistance. The current coating structure is a HC-CPI / PET-OCA-UTG multilayer structure.

[0004] A subsequent problem is that when coating the glass substrate, the material will shrink when the coating solidifies, and warping will occur on the plane after solidification, resulting in poor flatness of the final cover, which leads to large thickness deviation during the production process, greatly increasing the difficulty and instability of production. In addition, warping will also affect the appearance of the product and greatly affect the optical effect. Therefore, how to improve the mechanical properties of ultra-thin flexible glass is an issue that we need to pay attention to at present. Summary of the invention

[0005] Based on the above technical problems, the present invention provides a composite coating for the surface of flexible ultra-thin glass, in which the coating structure is transformed from a traditional multi-layer structure into a double-layer composite coating. The composite coating is applied to the surface of flexible ultra-thin glass, which can not only reduce the shrinkage rate but also improve the mechanical properties of the product.

[0006] The specific scheme of the present invention is as follows:

[0007] One of the purposes of the present invention is to provide a composite coating applied to the surface of ultra-thin flexible glass, the composite coating comprising a composite buffer layer and a hardening layer; wherein the hardening layer material comprises a functional resin, a photoinitiator and a solvent; and the composite buffer layer material comprises: a functional resin, a resin monomer, an active monomer, a photoinitiator and a solvent.

[0008] Preferably, in the hardened layer, the mass ratio of the functional resin to the photoinitiator is 50-100:0.5-5.

[0009] Preferably, in the composite buffer layer, the mass ratio of the functional resin, the resin monomer, the active monomer, and the photoinitiator is 50-100:10-50:1-10:0.5-5.

[0010] Preferably, the functional resin is a silicone-modified resin; more preferably, the functional resins in the hardening layer and the composite buffer layer are independently selected from one or more of silicone-modified polyurethane, silicone-modified epoxy resin, silicone-modified acrylic resin, and silicone-modified polyester.

[0011] Preferably, the resin monomer is selected from at least one of polyurethane, acrylate, and polyester; the active monomer is isocyanate; preferably, the active monomer is selected from at least one of benzene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, and naphthalene diisocyanate.

[0012] Preferably, the photoinitiators in the hardening layer and the composite buffer layer are both hydrogen-abstracting benzophenone-based type II photoinitiators.

[0013] The second object of the present invention is to provide a glass cover plate, comprising: an ultra-thin flexible glass and a composite coating coated on the surface of the ultra-thin flexible glass; the composite buffer layer in the composite coating covers the surface of the ultra-thin flexible glass.

[0014] Preferably, the thickness of the flexible glass is ≤100 μm, the thickness of the composite buffer layer is 10-30 μm, and the thickness of the hardening layer is 5-20 μm.

[0015] Preferably, the preparation method comprises the following steps: uniformly applying the composite buffer layer coating on the surface of the ultra-thin flexible glass, and sequentially performing thermal curing and photocuring treatments to obtain a composite buffer layer; then uniformly applying the hardening layer coating on the surface of the composite buffer layer, and sequentially performing thermal curing and photocuring treatments to obtain a glass cover plate.

[0016] Preferably, the thermal curing temperature is 60-90° C., and the thermal curing time is 8-22 min; more preferably, the thermal curing temperature is 65-80° C., and the thermal curing time is 15-20 min.

[0017] Preferably, UV lamp is used for light curing, with light energy of 500-700mj / cm 2 , light curing time 0.5-2min.

[0018] In order to facilitate coating, the present invention also designs a mold that can reduce the influence of surface tension when the coating is cured. The mold material is a groove with the same size as the substrate to be coated opened in the center of the plastic or polytetrafluoroethylene film product, and then the mold with the groove is placed on the coating machine, and the glass substrate is placed in the groove during coating, and finally the entire coating is performed.

[0019] The beneficial effects of the present invention are:

[0020] The composite coating of the present invention is a double-layer structure, which reduces the number of layers of the coating compared to the traditional HC-CPI / PET-OCA multi-layer structure, and its preparation process is simple and efficient. The surface of the hardened layer of the composite coating is close to the touch of glass, making the UTG cover plate lighter and smoother to use.

[0021] The functional resin in the hardening layer and the composite buffer layer of the present invention adopts organic silicon modified resin, which can increase the fluidity of the coating material and reduce the shrinkage of the material. Organic silicon can be used as a leveling agent in the system to make the coating self-leveling on the glass surface, increase the flatness of the coating, and enable it to have good adsorption with the glass substrate; the hydrogen-abstracting benzophenone type II photoinitiator can generate more free radicals to initiate oligomers and active monomers to polymerize and crosslink under UV irradiation, so as to further reduce the shrinkage of the coating. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 Schematic diagram of the structure of a glass cover plate taking 30μm UTG as an example;

[0023] Figure 2 This is a processing flow chart of the glass cover plate of the present invention; DETAILED DESCRIPTION

[0024] The technical solutions of the present invention are described in detail below through specific embodiments. However, it should be clearly stated that these embodiments are for illustration only and are not to be construed as limiting the scope of the present invention.

[0025] Example 1

[0026] A composite coating includes a composite buffer layer and a hardening layer, wherein: the composite buffer layer material includes: 70 parts of functional resin, 15 parts of resin monomer, 5 parts of active monomer, 3 parts of photoinitiator, and 7 parts of solvent. The hardening layer material includes: 80 parts of functional resin, 3 parts of photoinitiator, and 17 parts of solvent.

[0027] Among them, the functional resins are all silicone-modified polyurethanes, the resin monomer is polyurethane, the active monomer is isophorone diisocyanate (IPDI), the photoinitiators are all hydrogen-abstracting benzophenone type II photoinitiators, and the solvents are all dimethylformamide (DMF).

[0028] A glass cover plate includes: an ultra-thin flexible glass and a composite coating coated on the surface of the ultra-thin flexible glass; the composite coating is the composite coating described in this embodiment, and the composite buffer layer covers the surface of the flexible glass. The ultra-thin flexible glass has a thickness of 30 μm, the composite buffer layer has a thickness of 15 μm, and the hardening layer has a thickness of 8 μm. The preparation method thereof includes the following steps:

[0029] S1. Clean the surface of the ultra-thin flexible glass, heat and dry it to ensure that the product is free of dirt, oil and dirty spots;

[0030] S2, placing the ultra-thin flexible glass on a film-laminated coating mold with a groove having a depth of 30 μm;

[0031] S3, coating the composite buffer layer material evenly on the front surface of the ultra-thin flexible glass;

[0032] S4, fix the coated ultra-thin flexible glass on the bottom plate glass with glass protective film on the surface, and heat cure the coating of S3 at a temperature of 65°C for 15 minutes. After heat curing, the surface of the film has no dirty spots, no residual glue, and is resistant to solvent wiping;

[0033] S5. After the coating is thermally cured in S4, the coating is further photocured using a UV lamp with a light energy of 600 mj / cm 2 , light curing time is 1min, there is no dirty spot and no residual glue after UV light curing;

[0034] S6, repeat the steps of S2;

[0035] S7, coating the hardening layer material on the surface of the cured composite buffer layer;

[0036] S8, repeat the step of S4;

[0037] S9, repeat the step of S5;

[0038] S10. Clean the coated flexible glass obtained in S9 with pure water at 25°C for 50 minutes. Heat and dry the cleaned product to ensure that the product is free of dirt, oil and dirty spots.

[0039] Example 2

[0040] A glass cover plate comprises: flexible glass and a composite coating coated on the surface of the flexible glass; a composite buffer layer in the composite coating covers the surface of the flexible glass. The preparation method thereof is different from that of Example 1, except that in S4, the heat curing is performed at a temperature of 80° C. for 15 minutes.

[0041] Example 3

[0042] A glass cover plate comprises: flexible glass and a composite coating coated on the surface of the flexible glass; a composite buffer layer in the composite coating covers the surface of the flexible glass. The preparation method thereof is different from that of Example 1, except that in S4, the curing temperature is 80° C. and the curing time is 20 min.

[0043] Example 4

[0044] A glass cover plate comprises: flexible glass and a composite coating coated on the surface of the flexible glass; a composite buffer layer in the composite coating covers the surface of the flexible glass. The preparation method thereof is compared with that of Example 3, except that the energy in S5 is 650 mj / cm 2 .

[0045] Comparative Example 1

[0046] A glass cover plate includes: an ultra-thin flexible glass and a composite coating applied on the surface of the flexible glass; a composite buffer layer in the composite coating covers the surface of the flexible glass. The preparation method thereof is different from that of Example 3, except that the composite buffer layer material used in S3 is a polyurethane composite layer not modified with silicone, and the hardening layer material used in S7 is polyurethane not modified with silicone.

[0047] The glass cover plates obtained in the above examples and comparative examples were subjected to performance tests, and the test methods and results are as follows:

[0048] (1) Use a dynamic bending machine to test the bending performance;

[0049] (2) Using a pencil hardness tester, the ability of the composite coating to resist scratching is tested by scratching the coating surface with a pencil of standard hardness under a load of 750 g;

[0050] (3) Testing the optical transmittance of the glass cover plate using an optical transmittance tester;

[0051] (4) Testing the warpage of glass;

[0052] Table 1. Performance test results

[0053] Dynamic bending 750g load pencil hardness Optical transmittance Glass warpage Example 1 R1.0mm200,000 times 2H 92.2％ 0.3mm Example 2 R1.0mm200,000 times 2H 92.5％ 0.2mm Example 3 R1.0mm200,000 times 2H 95％ 0.1mm Comparative Example 1 R1.0mm200,000 times H 89％ 2mm

[0054] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A composite coating applied to the surface of ultra-thin flexible glass, characterized in that: The composite coating comprises a composite buffer layer and a hardening layer; wherein the hardening layer material comprises a functional resin, a photoinitiator and a solvent; and the composite buffer layer material comprises: a functional resin, a resin monomer, an active monomer, a photoinitiator and a solvent.

2. The composite coating applied to the surface of ultra-thin flexible glass according to claim 1, characterized in that: In the hardened layer, the mass ratio of the functional resin to the photoinitiator is 50-100:0.5-5.

3. The composite coating applied to the surface of ultra-thin flexible glass according to claim 1 or 2, characterized in that: In the composite buffer layer, the mass ratio of the functional resin, the resin monomer, the active monomer and the photoinitiator is 50-100:10-50:1-10:0.5-5.

4. The composite coating applied to the surface of ultra-thin flexible glass according to claim 1, characterized in that: The functional resin is an organosilicon-modified resin; preferably, the functional resins in the hardening layer and the composite buffer layer are independently selected from one or more of organosilicon-modified polyurethane, organosilicon-modified epoxy resin, organosilicon-modified acrylic resin, and organosilicon-modified polyester.

5. The composite coating applied on the surface of ultra-thin flexible glass according to claim 1, characterized in that: The resin monomer is selected from at least one of polyurethane, acrylate and polyester; the active monomer is isocyanate; preferably, the active monomer is selected from at least one of benzene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate and naphthalene diisocyanate.

6. The composite coating applied to the surface of ultra-thin flexible glass according to claim 1, characterized in that: The photoinitiators in the hardening layer and the composite buffer layer are both hydrogen-abstracting benzophenone type II photoinitiators.

7. A glass cover plate, characterized in that: include: Ultra-thin flexible glass and the composite coating according to any one of claims 1 to 6 coated on the surface of the ultra-thin flexible glass; The composite buffer layer in the composite coating covers the surface of the ultra-thin flexible glass.

8. The glass cover plate according to claim 7, characterized in that: The thickness of the flexible glass is ≤100 μm, the thickness of the composite buffer layer is 10-30 μm, and the thickness of the hardening layer is 5-20 μm.

9. The glass cover plate according to claim 7 or 8, characterized in that: The preparation method comprises the following steps: uniformly coating a composite buffer layer coating on the surface of an ultra-thin flexible glass, and sequentially performing heat curing and photocuring treatments on the composite buffer layer to obtain a composite buffer layer; then uniformly coating a hardening layer coating on the surface of the composite buffer layer, and sequentially performing heat curing and photocuring treatments to obtain a glass cover plate.

10. The glass cover plate according to claim 9, characterized in that: The thermal curing temperature is 60-90°C, and the thermal curing time is 8-22 minutes. Preferably, UV lamp is used for light curing, and the light energy is 500-700mj / cm 2 , light curing time 0.5-2min.

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