Preparation process of photonic crystal pressure-sensitive adhesive composite film

Abstract

The invention relates to a preparation process of a photonic crystal pressure-sensitive adhesive composite film, which comprises the following steps: selecting aliphatic TPU (thermoplastic polyurethane) particles as a substrate carrier, mixing the aliphatic TPU particles with photonic crystals, adding a brightening compound in the mixing process, granulating, extruding and casting to prepare a photonic crystal film substrate; coating one surface of the photonic crystal film substrate with a color layer, and coating the other surface of the photonic crystal film substrate with a glue solution to form a glue layer; finally, the surface of the color layer is coated with a self-repairing coating material, the self-repairing coating material and the protective film are attached and rolled after drying, and the photonic crystal pressure-sensitive adhesive composite film is obtained. The method has the following advantages that the situation that the binding force and the fitting degree of a final finished product are affected due to compounding of two traditional thin films is avoided, meanwhile, the technical problem that the glossiness is low due to direct film forming of TPU particles and photonic crystals is solved, and the overall use performance and the glossiness of a car model are further optimized.

Description

Technical Field

[0001] This invention belongs to the field of pressure-sensitive adhesive composite films, and specifically relates to a process for preparing a photonic crystal pressure-sensitive adhesive composite film. Background Technology

[0002] Photonic crystals are artificial periodic dielectric structures composed of alternating high-refractive-index and low-refractive-index materials, possessing photonic bandgap characteristics. Photonic crystals can selectively reflect specific wavelengths of visible light through their unique molecular arrangement, resulting in high gloss. Furthermore, their periodic dielectric structure reflects corresponding wavelengths within the visible light range, producing vibrant colors. Therefore, leading automotive brands are exploring the use of photonic crystal materials for custom paint colors; the iridescent effect of structural colors and their long-lasting colorfastness can enhance the aesthetics and durability of automotive exteriors.

[0003] Currently, when photonic crystals are used in the preparation of car covers, a pigment solution mixed with photonic crystals is coated onto a polyvinyl alcohol film, cured to form a photonic crystal film, and then coated onto the surface of a TPU film to finally form a photonic crystal composite film (photonic crystal pressure-sensitive adhesive composite film) with color-changing properties and high gloss. The following technical defects exist in the manufacturing process of this car cover: 1. The uniformity of the pigment solution and curing conditions affect the quality of the photonic crystal composite film. The bonding force and adhesion of the two films during the composite process also need to be precisely controlled, which increases the production difficulty and cost. Due to the double-layer film composite, the thickness is relatively high and the tensile properties are relatively poor, making it difficult to apply to the car later. 2. The photonic crystal film formed by the polyvinyl alcohol film and the TPU film are made of different materials, and the bonding force between them is insufficient. During use, especially when subjected to external forces (such as friction during car washing, thermal expansion and contraction caused by wind and sun exposure, etc.), the two films may delaminate or peel off, affecting the overall performance and service life of the car cover. 3. The optical performance of the photonic crystal depends on its internal periodic structure. This structure may be damaged during the manufacturing and use process. For example, if the conditions are not properly controlled during coating and curing, defects may appear in the periodic structure of the photonic crystal, thereby affecting its selective reflection of light and making the color and gloss of the car cover unstable.

[0004] Therefore, while current car covers containing photonic crystals can improve the aesthetics and durability of car exteriors, their gloss and overall performance cannot be guaranteed. During research, it has been proposed to directly combine photonic crystals with TPU particle photonic crystal films to effectively address the technical shortcomings of the aforementioned two film composites. However, directly forming films from TPU particles and photonic crystals also presents the following technical challenges: Firstly, the high melt viscosity of TPU (>500 Pa·s) results in significant resistance to photonic crystal migration and a mismatch in shear rates (photonic crystals require static self-assembly, while mixing involves dynamic shearing), disrupting the ordered structure of the photonic crystals and affecting gloss. Secondly, the competition between the TPU hard segments (polar urethane) and the hydroxyl hydrogen bonds on the photonic crystal surface leads to interfacial delamination. Excessive migration of surfactants during the mixing process to the TPU surface results in insufficient encapsulation around the photonic crystals, causing uneven dispersion or agglomeration, which also affects the gloss of the photonic crystal pressure-sensitive adhesive composite film.

[0005] Therefore, it is necessary to propose a photonic crystal pressure-sensitive adhesive composite film preparation process to effectively solve the above-mentioned technical problems. Summary of the Invention

[0006] The purpose of this invention is to overcome the above-mentioned shortcomings and provide a photonic crystal pressure-sensitive adhesive composite film preparation process, which avoids the influence of the bonding strength and adhesion of the final product on the traditional two-film composite process. At the same time, it solves the technical problem of low gloss caused by the direct film formation of TPU particles and photonic crystals, and further optimizes the overall performance and gloss of the car model.

[0007] The objective of this invention is achieved through the following technical solution: a process for preparing a photonic crystal pressure-sensitive adhesive composite film, comprising the following steps: Aliphatic TPU particles were selected as the substrate carrier and mixed with photonic crystals. Brightening compounds were added during the mixing process. After granulation, extrusion, and casting, a photonic crystal thin film substrate was formed. Then, a color layer was coated on one surface of the photonic crystal thin film substrate, and an adhesive solution was coated on the other surface of the photonic crystal thin film substrate to form an adhesive layer. Finally, a self-healing coating material was coated on the surface of the color layer, dried, and then bonded and rolled up with a protective film to obtain a photonic crystal pressure-sensitive adhesive composite film.

[0008] A further improvement of the present invention is that the brightening compound includes a surfactant and a dispersant; Surfactants include one or more of the following: amphoteric iminodipropionate monosodium salt, sodium isooctyl sulfate, ethylene dioleamide, fatty acid polyoxyethylene ester, hexadecyltrimethylammonium bromide, and fatty alcohol polyoxyethylene ether sulfate. The dispersant includes one or more of N-methylpyrrolidone, benzyl alcohol, propylene glycol methyl ether, triethylene glycol butyl ether, and methyl isobutyl ketone.

[0009] A further improvement of the present invention lies in: the preparation of the photonic crystal thin film substrate, including... A1. Select 90-95 parts by weight of aliphatic TPU particles and mix them with 4-10 parts of photonic crystal. The mixing temperature is 150-200℃ and the rotation speed is 100-200rpm to obtain mixture one. A2. Mix and stir 0.1-1 parts of amphoteric iminodipropionate monosodium salt, 0.1-1 parts of fatty acid polyoxyethylene ester, 0.1-1 parts of hexadecyltrimethylammonium bromide and 5-10 parts of triethylene glycol butyl ether to obtain mixture two; A3. Add mixture 2 to mixture 1, and then process it sequentially through granulation, extrusion, and casting to form a photonic crystal thin film substrate.

[0010] A further improvement of the present invention is that the hardness of the photonic crystal thin film substrate is 92-98A, the thickness is 100-200μm, and the gloss of the substrate is 90-100Gu.

[0011] A further improvement of the present invention is that: the adhesive solution uses polyacrylate as the main component, ethyl acetate as the solvent, and one or more of the following as additives: silicone leveling agent, film-forming agent, polyether modified siloxane leveling agent, and non-silicone non-fluorine leveling agent.

[0012] A further improvement of the present invention is that the preparation of the adhesive solution includes, B1. By weight fraction, select 0.1-1 parts of additives, 10-15 parts of polyacrylate, and 35-50 parts of ethyl acetate, and put them into a stirring tank. Stir at 200-300 r / min for 30-40 min to obtain a mixture. B2. Add 0.5-1 parts of terephthalic diisocyanate and 2-5 parts of ethyl acetate to a mixing tank, stir for 5-6 minutes, then add to the mixture and stir for 15-18 minutes to prepare a pressure-sensitive adhesive coating liquid with a solid content of 15-40% and a viscosity in the range of 100-1000.

[0013] A further improvement of the present invention is that the preparation of the self-healing coating material includes, C1. Polyether polyols with a molecular weight of 800-4000 are selected as white components, hexamethylene diisocyanate and ethyl acetate as black components, ethylene glycol as crosslinking agent, ethyl acetate as solvent, and dibutyltin dilaurate as catalyst. C2. By weight, add 0.1-0.2 parts catalyst, 15-18 parts white material, 2-4 parts crosslinking agent, 0.1-5 parts functional material, and the remainder 60-70 parts solvent. Stir at 150±50 r / min for 30-40 min. Add 4-5 parts black material and stir under the same conditions for 30-40 min. This is used as a self-healing coating material with a solid content of 15-40% and a viscosity between 100-1000.

[0014] A further improvement of the present invention is that the specific steps include: S1. A color layer with a thickness of 20-50μm is sprayed onto the bottom surface of the photonic crystal thin film substrate through a slit coating head. The other side of the photonic crystal thin film substrate is the substrate layer. After drying in an oven, a protective film is attached to the surface of the color layer and the substrate is rolled up. The substrate is placed at a temperature of 40-55℃ for 48-72 hours and then left to stand at room temperature for 24-48 hours to obtain semi-finished product one. S2. Apply the adhesive solution to the matte PET film through the comma coating head. The thickness is 20-50μm. After drying in the oven, an adhesive layer is formed. The adhesive layer is bonded to the substrate layer of semi-finished product one and rolled up. Let it stand at room temperature for 24-48h to obtain semi-finished product two. S3. Peel off the protective film on the surface of the color layer of the semi-finished product 2, and spray a self-healing coating material with a thickness of 5-20μm onto the color layer through a micro-grooving head to form a self-healing coating. After the self-healing coating is dried in an oven, it is bonded to the protective film and rolled up. It is placed at a temperature of 40-50℃ for 48-72h, and then left to stand at room temperature for 24-48h to obtain the finished photonic crystal pressure-sensitive adhesive composite film.

[0015] Compared with the prior art, the present invention has the following advantages: 1. The photonic crystal pressure-sensitive adhesive composite film of this invention is composed of a photonic crystal thin film substrate. A color layer and a self-healing coating material are sequentially coated on the surface of the photonic crystal thin film substrate. The photonic crystal thin film substrate is formed by mixing, melting and casting photonic crystals, aliphatic TPU particles, surfactants and dispersants. This preparation process uniformly disperses the photonic crystals in the aliphatic TPU body to form an integral structure, which can reduce the thickness of the photonic crystal pressure-sensitive adhesive composite film and reduce the difficulty of subsequent construction. Compared with traditional composite molded car covers, this application adds photonic crystals to the TPU film, which can form a dense TPU mesh structure around the photonic crystals, protecting the photonic crystals from the influence of external air, dust and organic matter, extending their service life. Moreover, the production process is simplified, reducing production costs and risks.

[0016] 2. In this application, the photonic crystal and TPU exhibit stronger bonding, with intermolecular diffusion and entanglement forming a robust physical and chemical bond. This allows the car cover to better maintain structural integrity and prevent delamination when subjected to various vibrations and external impacts. Furthermore, because the photonic crystal is uniformly distributed within the TPU, its arrangement and orientation can be better controlled, resulting in more stable and uniform optical performance. This allows for precise control of the reflection and absorption of different wavelengths of light, exhibiting more vibrant and durable colors and gloss. Coating the photonic crystal substrate with a color layer and a self-healing coating material enables a more sustained brightening effect under various usage conditions through its self-healing capabilities.

[0017] 3. In this invention, the surfactants selected are amphoteric iminodipropionate monosodium salt, fatty acid polyoxyethylene ester, and hexadecyltrimethylammonium bromide, and the dispersant is triethylene glycol butyl ether. Hexadecyltrimethylammonium bromide electrostatically binds to the negative charge on the surface of the photonic crystal, promoting the orderly arrangement of the photonic crystal in the melt and enhancing Bragg reflection efficiency. The long chains of fatty acid polyoxyethylene ester encapsulate the photonic crystal, preventing lattice distortion at high temperatures. The fatty acid polyoxyethylene ester preferentially migrates to the TPU-photonic crystal interface, solidifying to form an optically transparent interface layer. It improves gloss; the hydroxy acid of the amphoteric iminodipropionate monosodium salt is based on the hydrogen bonding of the hard segment of TPU, and the hydrophobic chain extends outward. The dispersant triethylene glycol butyl ether fills the soft segment region of TPU, reduces the melt viscosity, and promotes the migration of photonic crystals to the surface. At the same time, hexadecyltrimethylammonium bromide and fatty alcohol polyoxyethylene ether sodium sulfate are compounded to form an electric double layer, which prevents the photonic crystals from agglomerating at high temperatures. This effectively solves the technical defects of the current combination of TPU particles and photonic crystals, and further ensures the gloss and overall performance of the photonic crystal pressure-sensitive adhesive composite film. Detailed Implementation

[0018] To enhance understanding of the present invention, the present invention will be further described in detail below with reference to embodiments. These embodiments are only used to explain the present invention and do not constitute a limitation on the scope of protection of the present invention.

[0019] In the description of this invention, it should be understood that the terms indicating orientation or positional relationship are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the structure or unit referred to must have a specific orientation, and therefore should not be construed as a limitation of this invention.

[0020] In this invention, unless otherwise explicitly specified and limited, terms such as “connection,” “provided with,” and “have” should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection. They can be described as a mechanical connection, a direct connection, or a connection through an intermediate medium. Those skilled in the art can understand the basic meaning of the above terms in this invention according to the specific circumstances.

[0021] A process for preparing a photonic crystal pressure-sensitive adhesive composite film includes the following steps: Aliphatic TPU particles were selected as the substrate carrier and mixed with photonic crystals. Brightening compounds were added during the mixing process. After granulation, extrusion, and casting, a photonic crystal thin film substrate was formed. Then, a color layer was coated on one surface of the photonic crystal thin film substrate, and an adhesive solution was coated on the other surface of the photonic crystal thin film substrate to form an adhesive layer. Finally, a self-healing coating material was coated on the surface of the color layer, dried, and then bonded and rolled up with a protective film to obtain a photonic crystal pressure-sensitive adhesive composite film.

[0022] The photonic crystal pressure-sensitive adhesive composite film of this invention is composed of a photonic crystal thin film substrate. A color layer and a self-healing coating material are sequentially coated on the surface of the photonic crystal thin film substrate. The photonic crystal thin film substrate is formed by mixing, melting, and casting photonic crystals, aliphatic TPU particles, surfactants, and dispersants. This preparation process uniformly disperses the photonic crystals in the aliphatic TPU body to form an integral structure, which can reduce the thickness of the photonic crystal pressure-sensitive adhesive composite film and reduce the difficulty of subsequent construction. Compared with traditional composite molded car covers, this application adds photonic crystals to the TPU film, which can form a dense TPU mesh structure around the photonic crystals, protecting the photonic crystals from the influence of external air, dust, and organic matter, extending their service life. Moreover, the production process is simplified, reducing production costs and risks.

[0023] In this application, the photonic crystal and TPU exhibit stronger bonding, with intermolecular diffusion and entanglement forming a robust physical and chemical bond. This allows the car cover to better maintain structural integrity and prevent delamination when subjected to various vibrations and external impacts. Secondly, because the photonic crystal is uniformly distributed within the TPU, its arrangement and orientation can be better controlled, resulting in more stable and uniform optical performance. This allows for precise control of the reflection and absorption of different wavelengths of light, exhibiting more vibrant and durable colors and gloss. Furthermore, coating the photonic crystal substrate with a color layer and a self-healing coating material enables a more sustained brightening effect under various usage conditions through its self-healing capabilities.

[0024] Brightening compounds include surfactants and dispersants; Surfactants include one or more of the following: amphoteric iminodipropionate monosodium salt, sodium isooctyl sulfate, ethylene dioleamide, fatty acid polyoxyethylene ester, hexadecyltrimethylammonium bromide, and fatty alcohol polyoxyethylene ether sulfate. The dispersant includes one or more of N-methylpyrrolidone, benzyl alcohol, propylene glycol methyl ether, triethylene glycol butyl ether, and methyl isobutyl ketone.

[0025] Fabrication of photonic crystal thin film substrates, including A1. Select 90-95 parts by weight of aliphatic TPU particles and mix them with 4-10 parts of photonic crystal. The mixing temperature is 150-200℃ and the rotation speed is 100-200rpm to obtain mixture one. A2. Mix and stir 0.1-1 parts of amphoteric iminodipropionate monosodium salt, 0.1-1 parts of fatty acid polyoxyethylene ester, 0.1-1 parts of hexadecyltrimethylammonium bromide and 5-10 parts of triethylene glycol butyl ether to obtain mixture two; A3. Add mixture 2 to mixture 1, and then process it sequentially through granulation, extrusion, and casting to form a photonic crystal thin film substrate.

[0026] The photonic crystal thin film substrate prepared by the above steps has a hardness of 92-98A, a thickness of 100-200μm, and a gloss of 90-100Gu.

[0027] In this invention, the surfactants selected are amphoteric iminodipropionate monosodium salt, fatty acid polyoxyethylene ester, and hexadecyltrimethylammonium bromide, and the dispersant is triethylene glycol butyl ether. Hexadecyltrimethylammonium bromide electrostatically binds to the negative charge on the surface of the photonic crystal, promoting the orderly arrangement of the photonic crystal in the melt and enhancing Bragg reflection efficiency. The long chains of fatty acid polyoxyethylene ester encapsulate the photonic crystal, preventing lattice distortion at high temperatures. The fatty acid polyoxyethylene ester preferentially migrates to the TPU-photonic crystal interface, solidifying to form an optically transparent interface layer and improving gloss. Meanwhile, the hydroxy acids of the amphoteric iminodipropionate monosodium salt are bonded to the hard segments of TPU via hydrogen bonds, with hydrophobic chains extending outwards. The dispersant triethylene glycol butyl ether fills the soft segment regions of TPU, reducing melt viscosity and promoting the migration of the photonic crystal to the surface. Simultaneously, hexadecyltrimethylammonium bromide and fatty alcohol polyoxyethylene ether sodium sulfate form an electric double layer, preventing the photonic crystal from agglomerating at high temperatures. This effectively solves the current technical defects in the bonding of TPU particles and photonic crystals, further ensuring the gloss and overall performance of the photonic crystal pressure-sensitive adhesive composite film.

[0028] The adhesive solution uses polyacrylate as the main component, ethyl acetate as the solvent, and one or more of the following as additives: silicone leveling agent, film-forming agent, polyether-modified siloxane leveling agent, and non-silicone and non-fluorine leveling agent.

[0029] The preparation of the adhesive solution includes, B1. By weight fraction, select 0.1-1 parts of additives, 10-15 parts of polyacrylate, and 35-50 parts of ethyl acetate, and put them into a stirring tank. Stir at 200-300 r / min for 30-40 min to obtain a mixture. B2. Add 0.5-1 parts of terephthalic diisocyanate and 2-5 parts of ethyl acetate to a mixing tank, stir for 5-6 minutes, then add to the mixture and stir for 15-18 minutes to prepare a pressure-sensitive adhesive coating liquid with a solid content of 15-40% and a viscosity in the range of 100-1000.

[0030] The preparation of self-healing coating materials includes, C1. Polyether polyols with a molecular weight of 800-4000 are selected as white components, hexamethylene diisocyanate and ethyl acetate as black components, ethylene glycol as crosslinking agent, ethyl acetate as solvent, and dibutyltin dilaurate as catalyst. C2. By weight, add 0.1-0.2 parts catalyst, 15-18 parts white material, 2-4 parts crosslinking agent, 0.1-5 parts functional material, and the remainder 60-70 parts solvent. Stir at 150±50 r / min for 30-40 min. Add 4-5 parts black material and stir under the same conditions for 30-40 min. This is used as a self-healing coating material with a solid content of 15-40% and a viscosity between 100-1000.

[0031] The present invention combines a photonic crystal with aliphatic TPU particles to form a photonic crystal film, which, when combined with a high-transparency and high-definition self-healing coating, achieves a long-lasting brightening effect. The material has high compatibility with the photonic crystal and will not cause appearance problems during the production process. Minor scratches on the surface of the self-healing coating can be repaired by itself, and serious scratches can be repaired by heating. In addition, the self-healing coating material can be customized according to its function, such as adding functions such as stain resistance and scratch resistance.

[0032] A process for preparing a photonic crystal pressure-sensitive adhesive composite film includes the following steps: S1. A color layer with a thickness of 20-50μm is sprayed onto the bottom surface of the photonic crystal thin film substrate through a slit coating head. The other side of the photonic crystal thin film substrate is the substrate layer. After drying in an oven, a protective film is attached to the surface of the color layer and the substrate is rolled up. The substrate is placed at a temperature of 40-55℃ for 48-72 hours and then left to stand at room temperature for 24-48 hours to obtain semi-finished product one. S2. Apply the adhesive solution to the matte PET film through the comma coating head. The thickness is 20-50μm. After drying in the oven, an adhesive layer is formed. The adhesive layer is bonded to the substrate layer of semi-finished product one and rolled up. Let it stand at room temperature for 24-48h to obtain semi-finished product two. S3. Peel off the protective film on the surface of the color layer of the semi-finished product 2, and spray a self-healing coating material with a thickness of 5-20μm onto the color layer through a micro-grooving head to form a self-healing coating. After the self-healing coating is dried in an oven, it is bonded to the protective film and rolled up. It is placed at a temperature of 40-50℃ for 48-72h, and then left to stand at room temperature for 24-48h to obtain the finished photonic crystal pressure-sensitive adhesive composite film. Example

[0033] A process for preparing a photonic crystal pressure-sensitive adhesive composite film includes the following steps: S1. Fabrication of photonic crystal thin film substrate: S11. Select 90 parts by weight of aliphatic TPU particles and mix them with 4 parts of photonic crystal. The mixing temperature is 150℃ and the rotation speed is 100rpm to obtain mixture one. S12. Mix and stir 0.1 parts of amphoteric iminodipropionate monosodium salt, 0.1 parts of fatty acid polyoxyethylene ester, 0.1 parts of hexadecyltrimethylammonium bromide and 5 parts of triethylene glycol butyl ether to obtain mixture two; S13. Add mixture 2 to mixture 1, and then process it through granulation, extrusion and casting to form a photonic crystal thin film substrate. S2, the preparation of the adhesive solution includes, S21. By weight fraction, select 0.1 parts of additive, 10 parts of polyacrylate, and 35 parts of ethyl acetate, add them to a mixing tank and stir at 200 r / min for 30 min to obtain a mixture. S22. Add 0.5 parts of terephthalic diisocyanate and 2 parts of ethyl acetate to a mixing tank, stir for 5 minutes, then add to the mixture, stir for 15 minutes to prepare a pressure-sensitive adhesive coating liquid with a solid content of 15-40% and a viscosity in the range of 100-1000. S3. The preparation of self-healing coating materials includes, S31. Polyether polyols with a molecular weight of 800-4000 are selected as white components, hexamethylene diisocyanate and ethyl acetate as black components, ethylene glycol as crosslinking agent, ethyl acetate as solvent, and dibutyltin dilaurate as catalyst. S32. By weight, 0.1 parts catalyst, 15 parts white material, 2 parts crosslinking agent, 0.1 parts functional material, and the remainder 60 parts solvent are stirred at 100 r / min for 30 min. Then, 4 parts black material are added and stirred for 30 min under the same conditions. This is used as a self-healing coating material with a solid content in the range of 15-40% and a viscosity between 100-1000. S4. A 20μm thick color layer is sprayed onto the bottom surface of the photonic crystal thin film substrate through a slit coating head. The other side of the photonic crystal thin film substrate is the substrate layer. After drying in an oven, a protective film is attached to the surface of the color layer and the substrate is rolled up. The substrate is placed at 40℃ for 48 hours and then left to stand at room temperature for 24 hours to obtain semi-finished product one. S5. Apply the adhesive solution to the matte PET film through the comma coating head to a thickness of 20μm. After drying in the oven, an adhesive layer is formed. The adhesive layer is bonded to the substrate layer of semi-finished product one and rolled up. Let it stand at room temperature for 24 hours to obtain semi-finished product two. S6. Peel off the protective film on the surface of the color layer of the semi-finished product 2, and spray a self-healing coating material with a thickness of 5μm onto the color layer through a micro-grooving head to form a self-healing coating. After the self-healing coating is dried in an oven, it is bonded to the protective film and rolled up. It is placed at a temperature of 40℃ for 48 hours and then left to stand at room temperature for 24 hours to obtain the finished photonic crystal pressure-sensitive adhesive composite film. Example

[0034] A process for preparing a photonic crystal pressure-sensitive adhesive composite film includes the following steps: S1, the fabrication of photonic crystal thin film substrates, including S11. Select 95 parts by weight of aliphatic TPU particles and mix them with 10 parts of photonic crystal. The mixing temperature is 200℃ and the rotation speed is 200rpm to obtain mixture one. S12. Mix and stir 1 part of amphoteric iminodipropionate monosodium salt, 1 part of fatty acid polyoxyethylene ester, 1 part of hexadecyltrimethylammonium bromide and 10 parts of triethylene glycol butyl ether to obtain mixture two. S13. Add mixture 2 to mixture 1, and then process it through granulation, extrusion and casting to form a photonic crystal thin film substrate. S2, the preparation of the adhesive solution includes, S21. By weight fraction, select 1 part of the additive, 15 parts of polyacrylate and 50 parts of ethyl acetate, put them into a stirring tank and stir at 300 r / min for 40 min to obtain a mixture. S22. Add 1 part of terephthalic diisocyanate and 5 parts of ethyl acetate into a mixing tank, stir for 6 minutes, then add to the mixture, stir for 18 minutes, and prepare a pressure-sensitive adhesive coating liquid with a solid content of 15-40% and a viscosity in the range of 100-1000. S3. The preparation of self-healing coating materials includes, S31. Polyether polyols with a molecular weight of 800-4000 are selected as white components, hexamethylene diisocyanate and ethyl acetate as black components, ethylene glycol as crosslinking agent, ethyl acetate as solvent, and dibutyltin dilaurate as catalyst. S32. By weight, 0.2 parts of catalyst, 18 parts of white material, 4 parts of crosslinking agent, 5 parts of functional material, and the remainder of 70 parts of solvent are stirred at 200 r / min for 40 min. Then, 5 parts of black material are added and stirred for 40 min under the same conditions. This is used as a self-healing coating material with a solid content of 15-40% and a viscosity of 100-1000. S4. A color layer with a thickness of 50μm is sprayed onto the bottom surface of the photonic crystal thin film substrate through a slit coating head. The other side of the photonic crystal thin film substrate is the substrate layer. After drying in an oven, a protective film is attached to the surface of the color layer and the substrate is rolled up. The substrate is placed at 55℃ for 72 hours and then left to stand at room temperature for 48 hours to obtain semi-finished product one. S5. Apply the adhesive solution to the matte PET film through the comma coating head to a thickness of 50μm. After drying in the oven, an adhesive layer is formed. The adhesive layer is bonded to the substrate layer of semi-finished product one and rolled up. Let it stand at room temperature for 48 hours to obtain semi-finished product two. S6. Peel off the protective film on the surface of the color layer of the semi-finished product 2, and spray a self-healing coating material with a thickness of 20μm onto the color layer through a micro-grooving head to form a self-healing coating. After the self-healing coating is dried in an oven, it is bonded to the protective film and rolled up. It is placed at a temperature of 50℃ for 72 hours and then left to stand at room temperature for 48 hours to obtain the finished photonic crystal pressure-sensitive adhesive composite film. Example

[0035] A process for preparing a photonic crystal pressure-sensitive adhesive composite film includes the following steps: S1, the fabrication of photonic crystal thin film substrates, including S11. Select 92 parts by weight of aliphatic TPU particles and mix them with 8 parts of photonic crystal. The mixing temperature is 180℃ and the rotation speed is 150rpm to obtain mixture one. S12. Mix and stir 0.5 parts of amphoteric iminodipropionate monosodium salt, 0.5 parts of fatty acid polyoxyethylene ester, 0.5 parts of hexadecyltrimethylammonium bromide and 8 parts of triethylene glycol butyl ether to obtain mixture two; S13. Add mixture 2 to mixture 1, and then process it through granulation, extrusion and casting to form a photonic crystal thin film substrate. S2, the preparation of the adhesive solution includes, S21. By weight fraction, select 0.5 parts of additive, 12 parts of polyacrylate, and 40 parts of ethyl acetate, add them to a mixing tank and stir at 250 r / min for 35 min to obtain a mixture. S22. Add 0.8 parts of terephthalic diisocyanate and 4 parts of ethyl acetate to a mixing tank, stir for 5 minutes, then add to the mixture, stir for 16 minutes to prepare a pressure-sensitive adhesive coating liquid with a solid content of 15-40% and a viscosity in the range of 100-1000. S3. The preparation of self-healing coating materials includes, S31. Polyether polyols with a molecular weight of 800-4000 are selected as white components, hexamethylene diisocyanate and ethyl acetate as black components, ethylene glycol as crosslinking agent, ethyl acetate as solvent, and dibutyltin dilaurate as catalyst. S32. By weight, 0.15 parts catalyst, 16 parts white material, 3 parts crosslinking agent, 3 parts functional material, and the remainder 65 parts solvent are stirred at 150 r / min for 35 min. Then, 4.5 parts black material are added and stirred for 35 min under the same conditions. This is used as a self-healing coating material with a solid content of 15-40% and a viscosity of 100-1000. S4. A color layer with a thickness of 35μm is sprayed onto the bottom surface of the photonic crystal thin film substrate through a slit coating head. The other side of the photonic crystal thin film substrate is the substrate layer. After drying in an oven, a protective film is attached to the surface of the color layer and the substrate is rolled up. The substrate is placed at 50℃ for 60 hours and then left to stand at room temperature for 36 hours to obtain semi-finished product one. S5. Apply the adhesive solution to the matte PET film through the comma coating head to a thickness of 35μm. After drying in the oven, an adhesive layer is formed. The adhesive layer is bonded to the substrate layer of semi-finished product one and rolled up. Let it stand at room temperature for 36 hours to obtain semi-finished product two. S6. Peel off the protective film on the surface of the color layer of the semi-finished product 2, and spray a self-healing coating material with a thickness of 10μm onto the color layer through a micro-grooving head to form a self-healing coating. After the self-healing coating is dried in an oven, it is bonded to the protective film and rolled up. It is placed at a temperature of 45℃ for 36 hours and then left to stand at room temperature for 36 hours to obtain the finished photonic crystal pressure-sensitive adhesive composite film.

[0036] The table below shows the test data for Examples 1-3 and the comparative example (photonic crystal composite film in the background art):

[0037] As shown in the table above, the thickness of the photonic crystal pressure-sensitive adhesive composite film prepared in Examples 1-3 is 62-68 mm, which is slightly lower than the thickness of the photonic crystal pressure-sensitive adhesive composite film prepared in the comparative example, reducing the difficulty of later construction. The elongation of Examples 1-3 can reach 280-350%, which is much higher than the elongation of the photonic crystal pressure-sensitive adhesive composite film prepared in the comparative example, indicating that the photonic crystal pressure-sensitive adhesive composite film in this application has better tensile properties. The service life of Examples 1-3 can reach more than 5 years, and the gloss and color durability of the product are not affected within 5 years. However, after 1-2 years of use, most of the photonic crystal pressure-sensitive adhesive composite films prepared in the comparative example will have problems such as delamination, surface bubbles, reduced gloss, and discoloration, resulting in low service durability. The gloss of the photonic crystal pressure-sensitive adhesive composite film prepared in Examples 1-3 can reach 90-100 Gu, while the gloss of the photonic crystal pressure-sensitive adhesive composite film prepared in the comparative example is less than 80 Gu. Therefore, the technical solutions of Examples 1-3 are superior to those of the comparative example, while Example 2 is the best implementation scheme of this application.

[0038] Those skilled in the art should understand that this invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to this invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A process for preparing a photonic crystal pressure-sensitive adhesive composite film, characterized in that: The steps include, Aliphatic TPU particles were selected as the substrate carrier and mixed with photonic crystals. Brightening compounds were added during the mixing process. After granulation, extrusion, and casting, a photonic crystal thin film substrate was formed. Then, a color layer was coated on one surface of the photonic crystal thin film substrate, and an adhesive solution was coated on the other surface of the photonic crystal thin film substrate to form an adhesive layer. Finally, a self-healing coating material was coated on the surface of the color layer, dried, and then bonded and rolled up with a protective film to obtain a photonic crystal pressure-sensitive adhesive composite film.

2. The process for preparing a photonic crystal pressure-sensitive adhesive composite film according to claim 1, characterized in that: The brightening compound includes surfactants and dispersants; The surfactant includes one or more of the following: amphoteric iminodipropionate monosodium salt, sodium isooctyl sulfate, ethylene dioleamide, fatty acid polyoxyethylene ester, hexadecyltrimethylammonium bromide, and fatty alcohol polyoxyethylene ether sulfate. The dispersant includes one or more of N-methylpyrrolidone, benzyl alcohol, propylene glycol methyl ether, triethylene glycol butyl ether, and methyl isobutyl ketone.

3. The process for preparing a photonic crystal pressure-sensitive adhesive composite film according to claim 2, characterized in that: The preparation of the photonic crystal thin film substrate includes A1. Select 90-95 parts by weight of aliphatic TPU particles and mix them with 4-10 parts of photonic crystal. The mixing temperature is 150-200℃ and the rotation speed is 100-200rpm to obtain mixture one. A2. Mix and stir 0.1-1 parts of amphoteric iminodipropionate monosodium salt, 0.1-1 parts of fatty acid polyoxyethylene ester, 0.1-1 parts of hexadecyltrimethylammonium bromide and 5-10 parts of triethylene glycol butyl ether to obtain mixture two; A3. Add mixture 2 to mixture 1, and then process it sequentially through granulation, extrusion, and casting to form a photonic crystal thin film substrate.

4. The process for preparing a photonic crystal pressure-sensitive adhesive composite film according to claim 3, characterized in that: The hardness of the photonic crystal thin film substrate is 92-98A, the thickness is 100-200μm, and the gloss of the substrate is 90-100Gu.

5. The process for preparing a photonic crystal pressure-sensitive adhesive composite film according to claim 4, characterized in that: The adhesive solution uses polyacrylate as the main component, ethyl acetate as the solvent, and one or more of the following as additives: silicone leveling agent, film-forming agent, polyether-modified siloxane leveling agent, and non-silicone non-fluorine leveling agent.

6. The process for preparing a photonic crystal pressure-sensitive adhesive composite film according to claim 5, characterized in that: The preparation of the adhesive solution includes, B1. By weight fraction, select 0.1-1 parts of additives, 10-15 parts of polyacrylate, and 35-50 parts of ethyl acetate, and put them into a stirring tank. Stir at 200-300 r / min for 30-40 min to obtain a mixture. B2. Add 0.5-1 parts of terephthalic diisocyanate and 2-5 parts of ethyl acetate to a mixing tank, stir for 5-6 minutes, then add to the mixture and stir for 15-18 minutes to prepare a pressure-sensitive adhesive coating liquid with a solid content of 15-40% and a viscosity in the range of 100-1000.

7. The process for preparing a photonic crystal pressure-sensitive adhesive composite film according to claim 6, characterized in that: The preparation of the self-healing coating material includes, C1. Polyether polyols with a molecular weight of 800-4000 are selected as white components, hexamethylene diisocyanate and ethyl acetate as black components, ethylene glycol as crosslinking agent, ethyl acetate as solvent, and dibutyltin dilaurate as catalyst. C2. By weight, add 0.1-0.2 parts catalyst, 15-18 parts white material, 2-4 parts crosslinking agent, 0.1-5 parts functional material, and the remainder 60-70 parts solvent. Stir at 150±50 r / min for 30-40 min. Add 4-5 parts black material and stir under the same conditions for 30-40 min. This is used as a self-healing coating material with a solid content of 15-40% and a viscosity between 100-1000.

8. The process for preparing a photonic crystal pressure-sensitive adhesive composite film according to claim 7, characterized in that: The specific steps include, S1. A color layer with a thickness of 20-50μm is sprayed onto the bottom surface of the photonic crystal thin film substrate through a slit coating head. The other side of the photonic crystal thin film substrate is the substrate layer. After drying in an oven, a protective film is attached to the surface of the color layer and the substrate is rolled up. The substrate is placed at a temperature of 40-55℃ for 48-72 hours and then left to stand at room temperature for 24-48 hours to obtain semi-finished product one. S2. Apply the adhesive solution to the matte PET film through the comma coating head. The thickness is 20-50μm. After drying in the oven, an adhesive layer is formed. The adhesive layer is bonded to the substrate layer of semi-finished product one and rolled up. Let it stand at room temperature for 24-48h to obtain semi-finished product two. S3. Peel off the protective film on the surface of the color layer of the semi-finished product 2, and spray a self-healing coating material with a thickness of 5-20μm onto the color layer through a micro-grooving head to form a self-healing coating. After the self-healing coating is dried in an oven, it is bonded to the protective film and rolled up. It is placed at a temperature of 40-50℃ for 48-72h, and then left to stand at room temperature for 24-48h to obtain the finished photonic crystal pressure-sensitive adhesive composite film.

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