Transparent heating device and preparation method thereof
A multi-layered transparent heating element with nano-silver lines and a three-step curing process addresses the durability and transparency issues, ensuring high optical transmittance and long-term stability under harsh conditions.
Patent Information
- Application Number
- CN202510705025.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-29
- Publication Date
- 2025-07-15
AI Technical Summary
The existing transparent heating devices are insufficient in high temperature and humidity conditions and have low transmittance, which cannot meet the 800-hour aging test requirements.
A three-stage curing process is used to combine a transparent protective layer and a nano-silver transparent conductive layer. By providing a first and a second transparent protective layer on the lower surface of the transparent substrate and on the electrode layer, the polymer resin and additives are combined to improve the isolation performance of water vapor and oxygen.
It significantly improves the weather resistance, aging resistance and long-term stability of transparent heating devices, and meets the aging test requirements for 800 hours under high temperature and high humidity.
Smart Images
Figure CN120321826A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of flexible optical devices, and particularly relates to a transparent heating device and a preparation method thereof. Background Art
[0002] Currently, existing traditional heating optical devices usually use conductive polymers such as indium tin oxide thin films (ITO thin films) as transparent conductive layers, which can achieve the heating function when powered on. However, ITO thin films have problems of high brittleness and high cost. Although the flexibility of conductive polymer flexible heating sheets can meet the requirements, their optical transmittance is generally about 75 - 80%, which is difficult to meet the requirement of more than 85% transmittance for optical devices, and their resistance is relatively high, greater than 300 ohms. In addition, the stability of conductive polymers at high temperatures is insufficient and cannot meet the requirement of 800 - hour aging test under high temperature and high humidity. There are also some heating optical devices in the prior art that use nano - carbon as a transparent conductive heating sheet. Although the nano - carbon transparent conductive heating sheet has good stability, its optical transmittance is relatively low and cannot meet the requirement of more than 85% transmittance. There are also some heating optical devices that use nano - silver wires as transparent conductive layers, making their resistance less than 50 ohms, transmittance greater than 85%, resistant to bending, and having good flexibility. However, the power - on aging test stability of these heating optical devices is not good and they also cannot meet the requirement of 800 - hour aging test under high temperature and high humidity.
[0003] In view of this, it is necessary to develop a transparent heating device and a preparation method thereof that can meet the transmittance requirements, have good conductivity and flexibility, and can improve weather resistance, anti - aging property, and high - temperature and high - humidity stability, so as to solve the problems of insufficient stability, poor high - temperature and high - humidity anti - aging property, or low transmittance existing in existing transparent heating devices. Summary of the Invention
[0004] In order to overcome the deficiencies of the prior art, one of the purposes of the present invention is to provide a preparation method of a transparent heating device, which can make the transparent protective layer denser, have higher adhesion, and better isolation of water vapor and oxygen, thereby effectively improving the weather resistance, anti - aging property, and long - term stability of the transparent heating device.
[0005] To solve the above problems, the technical solutions adopted by the present invention are as follows: A preparation method of a transparent heating device, which comprises the following steps: S1. Clean and then dry the surface of the transparent substrate to remove dirt and grease on the surface of the transparent substrate; S2. Uniformly coat a transparent protective layer slurry on one side of the transparent substrate and perform a curing treatment to form a first transparent protective layer; S3. Uniformly print a nano - silver wire transparent slurry on the other side of the transparent substrate to form a nano - silver transparent conductive layer; S4. Print electrode paste on the nano-silver transparent conductive layer to form an electrode layer; S5. Uniformly coat transparent protective layer paste on the electrode layer and perform curing treatment to form a second transparent protective layer, thus obtaining the product; Among them, the curing treatment in step S2 and step S5 is specifically as follows: first bake at 30 - 80 °C for 30 - 300 min for low-temperature curing, then bake at 120 - 180 °C for 10 - 180 min for high-temperature curing, then bake at 60 - 100 °C for 30 - 300 min for low-temperature curing, and finally cool to room temperature.
[0006] As a preferred embodiment of the present invention, the transparent protective layer paste in step S2 and step S5 includes the following components by mass percentage: resin 70 - 95%, antioxidant 0.1 - 10%, UV-resistant auxiliary 0.1 - 20%.
[0007] Further preferably, the resin is selected from at least one of acrylic resin, polyurethane resin, epoxy resin, chlorinated ether resin, aldehyde-ketone resin, and vinyl chloride-vinyl acetate resin.
[0008] Further preferably, the antioxidant is at least one of pentaerythritol tetra[β-(3,5-di-tert-butyl,4-hydroxyphenyl)propionate], octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, butylated hydroxyanisole, bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, and tris(2,4-di-tert-butylphenyl) phosphite.
[0009] Further preferably, the UV-resistant auxiliary is at least one of phenyl salicylate, 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, and 2,4-dihydroxybenzophenone.
[0010] As a preferred embodiment of the present invention, the transparent substrate in step S1 is one of PET, glass, PI, CPI, PMMA, and PC.
[0011] As a preferred embodiment of the present invention, the thickness of the transparent substrate in step S1 is 0.01 - 2 mm.
[0012] As a preferred embodiment of the present invention, the length of the nano-silver wires in the nano-silver wire transparent paste in step S3 is 1 - 300 μm, the diameter is 10 - 200 nm, and the sheet resistance is less than 50 Ω.
[0013] As a preferred embodiment of the present invention, the electrode paste in step S4 is silver paste or copper paste.
[0014] The second object of the present invention is to provide a transparent heating device, which is prepared according to the above-mentioned preparation method.
[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: On the one hand, in the preparation method of the present invention, a first transparent protective layer and a second transparent protective layer are respectively provided on the lower surface of the transparent substrate and the upper surface of the electrode layer. This can not only protect the silver nanowires in the silver nanowire transparent conductive layer, but also the multi-layer transparent protective layers can improve the weather resistance, oxidation resistance and high-temperature stability of the transparent heating device to ultraviolet rays, effectively improving the barrier performance to water vapor and oxygen. On the other hand, by sequentially adopting three different curing processes of low-temperature curing, high-temperature curing, and low-temperature curing in combination, the transparent protective layer can be made more dense and have better adhesion, further improving the barrier performance to water vapor and oxygen, effectively delaying the attenuation of the barrier effect of the transparent substrate itself to water vapor and oxygen under long-term high-temperature and high-humidity conditions, and greatly increasing the aging life of the transparent heating device under long-term high-temperature and high-humidity conditions, well meeting the requirement of using for 800 hours. In summary, the transparent heating device prepared by the preparation method of the present invention has better barrier performance to water vapor and oxygen, can effectively improve the weather resistance, anti-aging property and long-term stability of the transparent heating device, making the transparent heating device of the present invention particularly suitable for scenarios such as automotive windshields, smart mirrors, and medical device displays. Brief Description of the Drawings
[0016] Figure 1 It is a schematic structural diagram of the transparent heating device described in the present invention; Explanation of the reference numerals in the drawings: 1, the first transparent protective layer; 2, the transparent substrate; 3, the silver nanowire transparent conductive layer; 4, the electrode layer; 5, the second transparent protective layer. Detailed Description of the Invention
[0017] The present invention will be further described in detail below with reference to the drawings and specific embodiments.
[0018] As Figure 1As shown in the figure, the transparent heating device provided by the present invention includes a first transparent protective layer 1, a transparent substrate 2, a nano-silver transparent conductive layer 3, an electrode layer 4, and a second transparent protective layer 5 that are stacked in sequence from bottom to top. Among them, the transparent substrate 2 is a supporting material for the transparent heating device, preferably one of PET, glass, PI, CPI, PMMA, and PC, and the thickness of the transparent substrate 2 is preferably 0.01 - 2 mm. The nano-silver transparent conductive layer 3 is formed by printing a nano-silver wire transparent paste containing nano-silver wires on the surface of the transparent substrate 2 by means of screen printing, gravure printing, spraying, spin coating, etc.; preferably, the length of the nano-silver wires is 1 - 300 μm, the diameter is 10 - 200 nm, the sheet resistance is less than 50 Ω, and the transmittance of the nano-silver wire transparent paste is greater than 85%. The electrode layer 4 is printed on the nano-silver transparent conductive layer 3 with an electrode paste such as silver paste or copper paste. The nano-silver transparent conductive layer 3 can be connected to an external power supply through the electrode layer 4 to achieve the heating function. The first transparent protective layer 1 and the second transparent protective layer 5 can, on the one hand, protect the nano-silver wires in the nano-silver transparent conductive layer 3, and on the other hand, improve the weather resistance, oxidation resistance, and high-temperature stability of the transparent heating device to ultraviolet rays, effectively improving the barrier performance to water vapor and oxygen; the first transparent protective layer 1 and the second transparent protective layer 5 are both obtained by uniformly coating a transparent protective layer paste and then curing it, and the transparent protective layer paste is made of a polymer resin and an additive.
[0019] Specifically, the preparation method of the above-mentioned transparent heating device includes the following steps: S1. Clean and dry the surface of the transparent substrate 2 to remove dirt and grease on the surface of the transparent substrate 2; S2. Uniformly coat the transparent protective layer paste on one side of the transparent substrate 2 and carry out a curing treatment to form the first transparent protective layer 1; S3. Uniformly print the nano-silver wire transparent paste on the other side of the transparent substrate 2 to form the nano-silver transparent conductive layer 3; S4. Print the electrode paste on the nano-silver transparent conductive layer 3 to form the electrode layer 4; S5. Uniformly coat the transparent protective layer paste on the electrode layer 4 and carry out a curing treatment to form the second transparent protective layer 5, thus obtaining the product; Among them, the curing treatment in step S2 and step S5 is specifically as follows: first bake at 30 - 80 °C for 30 - 300 min for low-temperature curing, then bake at 120 - 180 °C for 10 - 180 min for high-temperature curing, then bake at 60 - 100 °C for 30 - 300 min for low-temperature curing, and finally cool to room temperature.
[0020] The transparent protective layer paste in step S2 and step S5 comprises the following components by mass percentage: 70-95% of resin, 0.1-10% of antioxidant, and 0.1-20% of anti-ultraviolet auxiliary agent. In the above formula, the resin is preferably at least one of acrylic resin, polyurethane resin, epoxy resin, chlorinated ether resin, aldehyde-ketone resin, and vinyl chloride-vinyl acetate resin. The antioxidant is preferably at least one of pentaerythritol tetra[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], octadecyl β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, butylated hydroxyanisole, bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, and tris(2,4-di-tert-butylphenyl)phosphite. The anti-ultraviolet auxiliary agent is preferably at least one of phenyl salicylate, 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, and 2,4-dihydroxybenzophenone. In the above formula, the combination of the organic resin with the anti-ultraviolet auxiliary agent and the antioxidant can improve the ultraviolet resistance, antioxidant property, and high-temperature stability of the transparent heating device.
[0021] Example 1 A preparation method of a transparent heating device comprises the following steps: S1. Clean and dry the surface of the transparent glass to remove dirt and grease on the surface of the transparent glass; S2. Uniformly coat a first transparent protective layer paste on one side of the transparent glass. The first transparent protective layer paste consists of the following components by mass percentage: 90% of acrylic resin, 5% of phenyl salicylate, and 5% of octadecyl β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate; first bake at 80 °C for 120 min for low-temperature curing, then bake at 150 °C for 30 min for high-temperature curing, then bake at 100 °C for 30 min for low-temperature curing, and finally cool to room temperature to form a first transparent protective layer; S3. Uniformly print a nano-silver wire transparent paste on the other side of the transparent glass to form a nano-silver transparent conductive layer; the length of the nano-silver wires in the nano-silver wire transparent paste is 50 μm and the diameter is 15 nm; S4. Print silver paste on the nano-silver transparent conductive layer to form an electrode layer; S5. Uniformly coat a second transparent protective layer paste on the electrode layer. The second transparent protective layer paste consists of the following components by mass percentage: 90% of acrylic resin, 5% of 2,4-dihydroxybenzophenone, 2.5% of butylated hydroxyanisole, and 2.5% of tris(2,4-di-tert-butylphenyl)phosphite; first bake at 80 °C for 30 min for low-temperature curing, then bake at 150 °C for 60 min for high-temperature curing, then bake at 80 °C for 30 min for low-temperature curing, and finally cool to room temperature and perform a curing treatment to form a second transparent protective layer, thus obtaining the product.
[0022] Example 2 A preparation method of a transparent heating device, comprising the following steps: S1. Clean and dry the surface of the transparent PET to remove dirt and grease on the surface of the transparent PET; S2. Uniformly coat a first transparent protective layer slurry on one side of the transparent PET. The first transparent protective layer slurry is composed of the following components by mass percentage: 90% acrylic resin, 5% phenyl salicylate, 5% octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate; first bake at 50 °C for 120 min for low-temperature curing, then bake at 180 °C for 30 min for high-temperature curing, then bake at 100 °C for 30 min for low-temperature curing, and finally cool to room temperature to form the first transparent protective layer; S3. Uniformly print a nano-silver wire transparent slurry on the other side of the transparent PET to form a nano-silver transparent conductive layer; the length of the nano-silver wires in the nano-silver wire transparent slurry is 40 μm and the diameter is 15 nm; S4. Print copper paste on the nano-silver transparent conductive layer to form an electrode layer; S5. Uniformly coat a second transparent protective layer slurry on the electrode layer. The second transparent protective layer slurry is composed of the following components by mass percentage: 90% polyurethane, 5% 2,4-dihydroxybenzophenone, 2.5% butylated hydroxyanisole, 2.5% tris(2,4-di-tert-butylphenyl) phosphite; first bake at 80 °C for 100 min for low-temperature curing, then bake at 150 °C for 120 min for high-temperature curing, then bake at 80 °C for 60 min for low-temperature curing, and finally cool to room temperature and perform a curing treatment to form the second transparent protective layer, thus obtaining.
[0023] Example 3 A preparation method of a transparent heating device, comprising the following steps: S1. Clean and dry the surface of the transparent PMMA to remove dirt and grease on the surface of the transparent PMMA; S2. Uniformly coat a first transparent protective layer slurry on one side of the transparent PMMA. The first transparent protective layer slurry is composed of the following components by mass percentage: 90% polyurethane, 5% 2,4-dihydroxybenzophenone, 2.5% butylated hydroxyanisole, 2.5% tris(2,4-di-tert-butylphenyl) phosphite; first bake at 70 °C for 120 min for low-temperature curing, then bake at 150 °C for 30 min for high-temperature curing, then bake at 60 °C for 60 min for low-temperature curing, and finally cool to room temperature to form the first transparent protective layer; S3. Uniformly print the nano-silver wire transparent paste on the other side of the transparent PMMA to form a nano-silver transparent conductive layer; the length of the nano-silver wires in the nano-silver wire transparent paste is 40 μm and the diameter is 15 nm; S4. Print silver paste on the nano-silver transparent conductive layer to form an electrode layer; S5. Uniformly coat the second transparent protective layer paste on the electrode layer. The second transparent protective layer paste is composed of the following components by mass percentage: 90% acrylic resin, 5% 2,4-dihydroxybenzophenone, 2.5% butylated hydroxyanisole, and 2.5% tris(2,4-di-tert-butylphenyl) phosphite; first bake at 60 °C for 30 min for low-temperature curing, then bake at 150 °C for 120 min for high-temperature curing, then bake at 100 °C for 30 min for low-temperature curing, and finally cool to room temperature and perform curing treatment to form the second transparent protective layer, thus obtaining.
[0024] Comparative Example 1 This comparative example provides a method for preparing a transparent heating device. The difference between this comparative example and Example 1 is that the curing treatment in step S2 is: first bake at 80 °C for 120 min for low-temperature curing, then bake at 150 °C for 30 min for high-temperature curing, and finally cool to room temperature; the curing treatment in step S5 is: first bake at 80 °C for 30 min for low-temperature curing, then bake at 150 °C for 60 min for high-temperature curing, and finally cool to room temperature. The remaining steps are the same as those in Example 1.
[0025] Comparative Example 2 This comparative example provides a method for preparing a transparent heating device. The difference between this comparative example and Example 1 is that the curing treatment in step S2 is: bake at 150 °C for 30 min for curing; the curing treatment in step S5 is: bake at 150 °C for 30 min for curing. The remaining steps are the same as those in Example 1.
[0026] Comparative Example 3 This comparative example provides a method for preparing a transparent heating device. The difference between this comparative example and Example 1 is that the operation of step S2 is not performed, and the curing treatment in step S5 is: bake at 150 °C for 30 min for curing. The remaining steps are the same as those in Example 1.
[0027] Comparative Example 4 This comparative example provides a method for preparing a transparent heating device. The difference between this comparative example and Example 1 is that the operations of steps S2 and S5 are not performed, and the remaining steps are the same as those in Example 1.
[0028] High-temperature and high-humidity aging test The high-temperature and high-humidity aging tests were carried out on the transparent heating devices prepared in Examples 1 to 3 and Comparative Examples 1 to 4 under the same conditions. The specific operations are as follows: Apply the rated heating voltage of 12V to the whole transparent heating device. After the transparent heating device runs normally, keep the voltage unchanged and put the device into a high-temperature and high-humidity test chamber with a temperature of 85°C and a humidity of 85% for testing. After an appropriate number of hours, take it out for performance testing. The case where the original performance remains unchanged is considered to pass the corresponding duration.
[0029] The results are shown in Table 1.
[0030] Table 1 High-temperature and high-humidity aging test results of the transparent heating devices in Examples 1 to 3 and Comparative Examples 1 to 4
[0031] It can be seen from the data in Table 1 that due to the actual use requirements of the transparent heating device being more than 800 hours, in the case of conventional fixed-temperature curing for Comparative Examples 1 to 4, even if the protective layer formula and structure are optimized, they cannot meet the long-term requirement of 800 hours under the high-temperature and high-humidity conditions of 85°C and 85% humidity. Through the performance differences between Examples 1-3 and Comparative Examples 1 to 4, the three-stage curing can enable the whole device to meet or even far exceed the long-term requirement of 800 hours. By optimizing the formulas of the first transparent protective layer and the second transparent protective layer, the best ratio is achieved in Example 1, and its long-term performance reaches more than 1000 hours.
[0032] The above embodiments are only the preferred embodiments of the present invention and cannot be used to limit the scope of protection of the present invention. Any non-substantive changes and substitutions made by those skilled in the art based on the present invention belong to the scope of protection required by the present invention.
Claims
1. A method for preparing a transparent heating device, characterized in that: It includes the following steps: S1. Clean and then dry the surface of the transparent substrate to remove dirt and grease on the surface of the transparent substrate; S2. Uniformly coat a transparent protective layer slurry on one side of the transparent substrate and perform a curing treatment to form a first transparent protective layer; S3. Uniformly print a nano silver wire transparent slurry on the other side of the transparent substrate to form a nano silver transparent conductive layer; S4. Print an electrode slurry on the nano silver transparent conductive layer to form an electrode layer; S5. Uniformly coat a transparent protective layer slurry on the electrode layer and perform a curing treatment to form a second transparent protective layer, thus obtaining the product; Among them, the curing treatment in step S2 and step S5 is specifically as follows: first bake at 30 - 80 °C for 30 - 300 min for low-temperature curing, then bake at 120 - 180 °C for 10 - 180 min for high-temperature curing, then bake at 60 - 100 °C for 30 - 300 min for low-temperature curing, and finally cool to room temperature.
2. The preparation method of the transparent heating device according to claim 1, characterized in that: The transparent protective layer slurry in step S2 and step S5 includes the following components by mass percentage: resin 70 - 95%, antioxidant 0.1 - 10%, ultraviolet resistance auxiliary 0.1 - 20%.
3. The manufacturing method of the transparent heating device according to claim 2, wherein: The resin is selected from at least one of acrylic resin, polyurethane resin, epoxy resin, chlorinated ether resin, aldehyde-ketone resin, and vinyl chloride-vinyl acetate resin.
4. The manufacturing method of the transparent heating device according to claim 2, wherein: The antioxidant is at least one of pentaerythritol tetrakis [β-(3,5-di-tert-butyl,4-hydroxyphenyl) propionate], octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate, butylated hydroxyanisole, bis (2,4-di-tert-butylphenyl) pentaerythritol diphosphite, and tris (2,4-di-tert-butylphenyl) phosphite.
5. The manufacturing method of the transparent heating device according to claim 2, characterized in that: The ultraviolet resistance auxiliary is at least one of phenyl salicylate, 2-(2'-hydroxy-5'-methylphenyl) benzotriazole, and 2,4-dihydroxybenzophenone.
6. The manufacturing method of the transparent heating device according to claim 1, characterized in that: The transparent substrate in step S1 is one of PET, glass, PI, CPI, PMMA, and PC.
7. The method for preparing a transparent heating device according to claim 1 or 6, characterized in that: The thickness of the transparent substrate in step S1 is 0.01 - 2 mm.
8. The preparation method of the transparent heating device according to claim 1, characterized in that: The length of the nano silver wires in the nano silver wire transparent slurry in step S3 is 1 - 300 μm, the diameter is 10 - 200 nm, and the sheet resistance is less than 50 Ω.
9. The preparation method of the transparent heating device according to claim 1, wherein: The electrode slurry in step S4 is silver paste or copper paste.
10. A transparent heating device, characterized in that: The transparent heating device is prepared by the preparation method described in any one of claims 1 to 9.