Functional coating as well as preparation method and application thereof

Abstract

The invention provides a functional coating as well as a preparation method and application thereof. The functional coating is prepared from the following raw materials: elastic resin, adhesive force resin, a curing agent, an auxiliary agent and a diluent. The functional coating prepared by the invention can be prepared into a single component, does not gel at normal temperature, can be used for a long time, avoids frequent machine washing and material replacement, has good elasticity, can immediately repair slight scratches, has good adhesion to glass, and has a water boiling cross-cut test of 5B under the condition of no primer. And after coating, the foldable glass is free from breakage, whitening, falling and crease after being bent for 200,000 times at 360 degrees under the conditions that the bending radius is 1.0 mm and the temperature is-20 DEG C to 100 DEG C and the relative humidity is 10 to 95 percent. The glass anti-explosion coating is good in anti-explosion performance, glass can be completely adhered to the coating after being broken, and when the glass anti-explosion coating is used for middle-bendable glass, due to the fact that the refractive index is close to that of the glass, etching lines formed when the middle of the glass is thinned independently can be well covered.

Description

Technical Field

[0001] The present invention belongs to the technical field of coatings, and relates to a functional coating and a preparation method and application thereof, and specifically relates to a functional coating for foldable glass and a preparation method thereof. Background Art

[0002] With the development of display technology, the performance requirements for the screen in display devices are gradually increasing. And with the expansion of application scenarios, ultra-thin glass-based flexible display panels can be applied to foldable mobile phones, laptops and various curled display devices.

[0003] In order to meet the bendability of glass, the bending area must be very thin, which requires corresponding protection and explosion-proof coating. Because the terminal products made of foldable glass need to meet various harsh environments, the performance requirements of the coating are very high: 1. Low environmental sensitivity, good elasticity and bendability, 360° dynamic bending 200,000 times under the conditions of bending radius 1mm under -20℃ to 100℃, relative humidity 10-95%, static bending (inside and outside) 10d coating should not break, fog or crease. 2. Good adhesion to glass, 95℃ water boiling for 2h coating should not turn white or fall off, and 100 grids must be 5B. 3. Transmittance, haze, and chromaticity must meet the requirements. 4. After 10d of ultraviolet aging test, it must still meet the above requirements. 5. The closer the refractive index is to the glass, the better, and the micro-etching patterns on the glass surface can be better covered.

[0004] Under the condition of meeting the coating performance, the coating process has the following requirements for the coating: 1. The coating operation time should be long enough, and frequent machine washing and replacement of liquid should be avoided as much as possible. 2. The coating viscosity changes little over time to avoid causing differences in coating thickness. 3. The coating surface should dry quickly to reduce the impact of dust in the environment on the coating appearance. 4. The fewer the number of coating layers, the better, and the higher the yield.

[0005] The existing polyurethane glass coating generally uses ordinary isocyanate as a curing agent, the room temperature operation time is short, and the coating viscosity gradually increases over time, especially when it is prepared as a quick-drying coating, the viscosity changes faster and the operation time is shorter. At the same time, the existing glass coating is generally a hard coating when designed as a single-layer structure, which will break when folded outward. If it is made into an elastic coating, a separate primer layer is required (the primer is not a coupling agent layer).

[0006] In summary, when coating the surface of foldable glass, the selection of coating materials is very critical, and it is essential to develop a functional coating that can meet both coating performance and coating process requirements. Summary of the invention

[0007] In view of the deficiencies of the prior art, the purpose of the present invention is to provide a functional coating and a preparation method and application thereof, and specifically to provide a functional coating for foldable glass and a preparation method thereof. The functional coating prepared by the present invention can be prepared as a single component, does not gel at room temperature, can be used for a long time, avoids frequent machine washing and material replacement, and has good elasticity. Minor scratches can be repaired immediately, and the adhesion to the glass is good. In the absence of primer, the water boiling test is 5B. After coating, the foldable glass can be bent 200,000 times at 360° at a bending radius of 1.0mm at -20℃-100℃ and a relative humidity of 10-95% without breakage, whitening, falling off, or creases. It has good explosion-proof properties, and the glass can be completely adhered to the coating after being broken. When used for the middle bendable glass, because the refractive index is close to that of the glass, it can also well cover the etching lines formed when the middle part of the glass is thinned separately.

[0008] To achieve this object, the present invention adopts the following technical solutions:

[0009] In a first aspect, the present invention provides a functional coating, wherein raw materials for preparing the functional coating include an elastic resin, an adhesion resin, a curing agent, an auxiliary agent and a diluent.

[0010] The functional coating provided by the present invention adopts elastic resin as the main resin, and adds adhesion resin, additives, diluents and curing agents at the same time. The elastic resin has good compatibility with the adhesion resin, good fluidity, and no whitening or fogging after curing. The coating can adhere well to the glass when it is a single layer. At the same time, the coating does not cross-link at room temperature, and the viscosity does not change with time.

[0011] Preferably, the elastic resin includes any one of a hydroxyl-terminated polyolefin resin, a saturated aliphatic polyester resin, a polycarbonate resin, a polyether polyol resin or a hydroxyl-terminated polyurethane resin, or a combination of at least two thereof.

[0012] Preferably, the adhesion resin comprises any one or a combination of at least two of aromatic polyester resin, alicyclic polyester resin, hydroxy acrylic resin or alkyd resin, preferably aromatic polyester resin. The present invention uses an adhesion resin having good compatibility with the elastic resin, and the combination of the two ensures both the adhesion and elasticity of the functional coating. At the same time, the selected adhesion resin has a high refractive index, and the refractive index of the functional coating finally prepared is close to that of glass.

[0013] Preferably, the curing agent comprises blocked isocyanate.

[0014] Preferably, the curing agent includes any one or a combination of at least two of a hexamethylene diisocyanate (HDI) blocked derivative, an isophorone diisocyanate (IPDI) blocked derivative or a cyclohexane dimethylene diisocyanate (H-XDI) blocked derivative.

[0015] By adding a blocked curing agent, the coating does not react at room temperature and the viscosity does not change.

[0016] Preferably, the auxiliary agent includes a leveling agent and / or a drying agent.

[0017] Preferably, the leveling agent includes any one of an organic silicon leveling agent, a non-silicon leveling agent or a fluorine-containing leveling agent, or a combination of at least two thereof.

[0018] Preferably, the drier comprises an organotin drier and / or an organobismuth drier.

[0019] Preferably, the diluent includes any one of a ketone diluent, an ether diluent or an ester diluent, or a combination of at least two of them.

[0020] Preferably, the diluent includes any one of acetone, butanone, methyl isobutyl ketone, cyclohexanone, isophorone, butyl ether, methyl ester, ethyl ester, propyl ester, butyl ester, pentyl ester, ethylene glycol butyl ether acetate, ethylene glycol ethyl ether acetate or propylene glycol methyl ether acetate, or a combination of at least two thereof.

[0021] Preferably, the raw materials for preparing the functional coating include the following components in parts by weight:

[0022]

[0023]

[0024] Preferably, the raw materials for preparing the functional coating are calculated by weight, and the amount of the elastic resin used can be 10 parts, 13 parts, 15 parts, 18 parts, 20 parts, etc.

[0025] Preferably, the raw materials for preparing the functional coating are measured in parts by weight, and the amount of the adhesion resin can be 10 parts, 13 parts, 15 parts, 18 parts, 20 parts, etc.

[0026] Preferably, the raw materials for preparing the functional coating are calculated in parts by weight, and the amount of the curing agent is calculated based on the hydroxyl values ​​of the elastic resin and the adhesion resin.

[0027] Preferably, the amount of the leveling agent used in the preparation of the functional coating can be 0.1 part, 0.2 part, 0.3 part, 0.4 part, 0.5 part, etc., based on weight parts, and more preferably 0.3-0.6% of the total weight of the resin.

[0028] Preferably, the raw materials for preparing the functional coating are measured in parts by weight, and the amount of the drying agent used can be 0.01 parts, 0.02 parts, 0.03 parts, 0.05 parts, 0.1 parts, etc.

[0029] Preferably, the raw materials for preparing the functional coating are measured in parts by weight, and the amount of diluent used can be 20 parts, 30 parts, 40 parts, 50 parts, 60 parts, 70 parts, 80 parts, 90 parts, 100 parts, etc., depending on the construction viscosity. The amount of solvent does not affect the coating performance.

[0030] In a second aspect, the present invention provides a method for preparing the functional coating according to the first aspect, the preparation method comprising the following steps:

[0031] The elastic resin, the adhesion resin, the auxiliary agent, the curing agent and the diluent are mixed to obtain a coating, the coating is applied to the surface of the substrate, and heated and cured to obtain the functional coating.

[0032] Preferably, the substrate comprises foldable glass (when the substrate is glass, it needs to be treated with a coupling agent, and the coupling agent layer has no thickness, which is different from a primer).

[0033] Preferably, the curing temperature is 130-150°C, for example, 130°C, 135°C, 140°C, 142°C, 144°C, 146°C, 148°C or 150°C.

[0034] In a third aspect, the present invention provides an application of the functional coating as described in the first aspect in foldable glass.

[0035] Compared with the prior art, the present invention has at least the following beneficial effects:

[0036] The functional coating provided by the present invention adopts elastic resin as the main resin, and simultaneously adds adhesion resin, additives, diluents and curing agents. The elastic resin has good compatibility with the adhesion resin, good fluidity, and no whitening or fogging after curing. When the coating is a single layer, it can adhere well to the glass treated with a coupling agent. At the same time, the coating does not cross-link at room temperature, and the viscosity does not change with time. DETAILED DESCRIPTION

[0037] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0038] The raw material information used in the examples and comparative examples of the present invention is as follows:

[0039] (1) Elastic resin

[0040] Hydroxyl-terminated polyolefin resin: Hydroxyl-terminated polybutadiene produced by Yingkou Tianyuan Aviation Materials Co., Ltd.

[0041] Saturated aliphatic polyester resin: Dongguan Zuorong Industrial 18# resin;

[0042] Polycarbonate resin: Dongguan Zuorong Industrial 331 resin;

[0043] (2) Adhesion resin

[0044] Aromatic polyester resin: Shenzhen Jiashengda Polymer Material 7817 resin;

[0045] Hydroxylated acrylic resin: Dongguan Jinmei Chemical 3519 resin;

[0046] (3) Additives

[0047] Leveling agent: BYK silicone leveling agent, BYK organic fluorine leveling agent;

[0048] Drier: organic tin drier;

[0049] (4) Curing agent

[0050] Isocyanate: Desmodur 3175 blocked isocyanate curing agent, Covestro 3390 curing agent;

[0051] (5) Diluent

[0052] Ethyl acetate, propylene glycol methyl ether acetate.

[0053] Examples 1-6

[0054] In Examples 1-6, a functional coating is provided respectively, and the raw material selection and dosage (weight parts) of the functional coating are shown in Table 1.

[0055] The preparation method comprises the following steps:

[0056] The elastic resin, adhesion resin, additive, curing agent and diluent are mixed to obtain a coating, which is then applied to the surface of the foldable glass treated with an amino coupling agent by a slit coater. The coating thicknesses are 20 μm, 40 μm and 60 μm, respectively. The coating is baked at 135°C for 1 hour to obtain functional coatings of different thicknesses.

[0057] Comparative Examples 1-3

[0058] In Comparative Examples 1-3, a functional coating is provided respectively, and the raw material selection and dosage (weight parts) of the functional coating are shown in Table 1.

[0059] The preparation method is the same as that in the example.

[0060] Table 1

[0061]

[0062]

[0063] The coatings and functional coatings provided in the embodiments of the present invention and the comparative examples were subjected to performance tests, and the test methods were as follows:

[0064] (1) Operation time: the time from the preparation of the coating glue to the gelling time;

[0065] (2) Refractive index: The refractive index of the functional coating is tested using an Abbe refractometer;

[0066] (3) Boiled water for 100 grids: Boil the functional coating in water at 95°C for 2 hours and then place it for 30 minutes before conducting a 100 grid test;

[0067] (4) Transmittance, chromaticity, and haze: Use a spectrophotometer to test the functional coating;

[0068] (5) Bending test: The foldable glass coated with the functional coating is tested using a book-turning bending machine with a bending radius of R = 1.0 mm, divided into inward bending and outward bending.

[0069] The performance test results are shown in Tables 2 to 4.

[0070] Among them, Table 2 is the basic performance test results of the functional coating, Table 3 is the test results of the functional coating with a thickness of 20μm, 40μm, and 60μm, which was folded inward 200,000 times under the bending radius R=1.0mm, different temperature and humidity conditions; Table 4 is the test results of the functional coating with a thickness of 20μm, 40μm, and 60μm, which was folded outward 200,000 times under the bending radius R=1.0mm, different temperature and humidity conditions.

[0071] Table 2

[0072]

[0073]

[0074] Table 3

[0075]

[0076] Table 4

[0077]

[0078] From the comparison between Examples 1-6 and Comparative Example 3 in Table 2, it can be seen that after replacing the ordinary isocyanate curing agent with a blocked isocyanate curing agent, the coating will not gel at room temperature, frequent machine washing and material replacement can be avoided, and the product quality is more stable.

[0079] From the comparison between Example 1 and Comparative Example 1, it can be seen that without adding adhesion resin, the elastic resin alone has poor adhesion to the glass, and the functional coating falls off directly during the water boiling test.

[0080] From the comparison between Example 7, Comparative Example 1 and other examples, it can be seen that the addition of aromatic polyester resin can make the refractive index of the functional coating close to that of glass (glass refractive index 1.500-1.515), and can cover the glass etching pattern.

[0081] It can be seen from Tables 3 and 4 that in Comparative Example 2, no elastic resin is added, but only adhesion resin is added. The functional coating is hard and inelastic at room temperature and low temperature. Creases appear in the bending zone when folded inward, and the coating breaks directly when folded outward.

[0082] The applicant declares that the present invention illustrates the functional coating and its preparation method and application through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned embodiments, that is, it does not mean that the present invention must rely on the above-mentioned embodiments to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of various raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A functional coating, characterized in that: The raw materials for preparing the functional coating include elastic resin, adhesion resin, curing agent, auxiliary agent and diluent.

2. The functional coating according to claim 1, characterized in that The elastic resin includes any one of a hydroxyl-terminated polyolefin resin, a saturated aliphatic polyester resin, a polycarbonate resin, a polyether polyol resin or a hydroxyl-terminated polyurethane resin, or a combination of at least two thereof.

3. The functional coating according to claim 1 or 2, characterized in that: The adhesion resin includes any one of aromatic polyester resin, alicyclic polyester resin, hydroxy acrylic resin or alkyd resin, or a combination of at least two of them.

4. The functional coating according to any one of claims 1 to 3, characterized in that The curing agent includes a blocked isocyanate; Preferably, the curing agent includes any one of hexamethylene diisocyanate blocked derivatives, isophorone diisocyanate blocked derivatives or cyclohexane dimethylene diisocyanate blocked derivatives, or a combination of at least two thereof.

5. The functional coating according to any one of claims 1 to 4, characterized in that: The auxiliary agent includes a leveling agent and / or a drying agent; Preferably, the leveling agent includes any one of an organic silicon leveling agent, a non-silicon leveling agent or a fluorine-containing leveling agent, or a combination of at least two thereof; Preferably, the drier comprises an organotin drier and / or an organobismuth drier.

6. The functional coating according to any one of claims 1 to 5, characterized in that: The diluent includes any one of a ketone diluent, an ether diluent or an ester diluent, or a combination of at least two thereof; Preferably, the diluent includes any one of acetone, butanone, methyl isobutyl ketone, cyclohexanone, isophorone, butyl ether, methyl ester, ethyl ester, propyl ester, butyl ester, pentyl ester, ethylene glycol butyl ether acetate, ethylene glycol ethyl ether acetate or propylene glycol methyl ether acetate, or a combination of at least two thereof.

7. The functional coating according to any one of claims 1 to 6, characterized in that: The raw materials for preparing the functional coating include the following components in parts by weight:

8. A method for preparing a functional coating according to any one of claims 1 to 7, characterized in that: The preparation method comprises the following steps: The elastic resin, the adhesion resin, the auxiliary agent, the curing agent and the diluent are mixed to obtain a coating, the coating is applied to the surface of the substrate, and heated and cured to obtain the functional coating.

9. The preparation method according to claim 8, characterized in that: The substrate includes foldable glass; Preferably, the curing temperature is 130-150°C.

10. Use of the functional coating according to any one of claims 1 to 7 in foldable glass.

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