A pet packaging bottle with wavelength selective reflection function and a preparation method thereof

Abstract

The application discloses a PET packaging bottle with wavelength selective reflection function and a preparation method thereof, the PET packaging bottle comprises a bottle body and a wavelength selective reflection layer formed on at least part of the outer surface and / or the inner surface of the bottle body; the wavelength selective reflection layer has a micro-matrix structure, the micro-matrix structure is composed of a plurality of prism-shaped micro-reflection units arranged, and is used for realizing directional reflection on a harmful light wave band with a wavelength in the range of 300-600 nm, while allowing safe visible light with a wavelength above 650 nm to be transmitted; through the directional reflection design of the prism-shaped micro-reflection unit, the application can realize efficient reflection on the harmful light with a wavelength of 300-600 nm without adding any colorant or absorbent, while allowing the safe visible light above 650 nm to be highly transmitted, realizes selective blocking of the harmful light on the premise of maintaining high transparency of the bottle body, and effectively solves the problems that the bottle body transparency is reduced and the light blocking and content visibility cannot be considered in the prior art due to the addition of the colorant, the absorbent or the inorganic filler.

Description

Technical Field

[0001] This invention relates to the field of packaging materials technology, specifically to a PET packaging bottle with wavelength selective reflection function and its preparation method. Background Technology

[0002] PET (polyethylene terephthalate) packaging bottles are widely used in beverage, food, and pharmaceutical packaging due to their high transparency, light weight, recyclability, and diverse shapes. However, PET material itself lacks effective blocking ability for ultraviolet light and some visible light wavelengths, which limits its application in the packaging of photosensitive products. Studies have shown that PET material has the ability to absorb ultraviolet light with wavelengths below 315nm, but lacks effective blocking of harmful light in the 315-600nm wavelength range. This wavelength range is the main factor causing vitamin degradation, fat oxidation, and pigment fading in dairy products, fruit juices, and pharmaceuticals.

[0003] To address the aforementioned issues, various light-blocking solutions have been proposed in the existing technology.

[0004] Chinese patent CN103788597A discloses a PET bottle containing a UV color blocker and its manufacturing process. This method involves adding a UV absorber and a colorant (dye) to the PET raw material, enabling the UV color blocker to block ultraviolet light and visible light at least 450nm. The inventors of this patent point out that existing UV absorbers typically block ultraviolet light below 370nm, but offer less protection against ultraviolet light in the 370-400nm range, and offer no protection against visible light in the 400-700nm range, a wavelength that can also damage beverage ingredients. However, this method has significant drawbacks: the addition of colorants darkens the bottle color and significantly reduces transparency, making it impossible for consumers to visually inspect the contents; furthermore, some additives pose a migration risk, affecting food safety.

[0005] US Patent 20030204000A1 discloses a polyester composition that achieves ultraviolet light blocking by mixing 10-1000 ppm of azidobenzene ultraviolet absorber and 0.01-2 mol% of 2,6-naphthalenedicarboxylic acid copolyester. This composition can effectively absorb ultraviolet light below and above 360 ​​nm without significantly increasing haze. However, this method is still an additive light absorption technology, and its ability to block harmful light in a wider wavelength range (such as 400-600 nm) is limited.

[0006] Chinese patent CN202310129263 discloses a light-blocking bottle and its manufacturing method. The method achieves localized light blocking by forming a barrier component at the bottom of the preform with a thickness 0.16-0.45 times the total thickness of the preform bottom. This, combined with a light-blocking label on the bottle body, achieves overall light blocking. This solution uses a step-by-step injection molding process to create a clear axial boundary between the barrier component and the preform body, improving upon existing three-layer injection molding technologies where the barrier layer thickness is uncontrollable and material distribution during blow molding is uneven. However, the multi-layer co-injection method still suffers from drawbacks such as high equipment investment and complex processes, and the label method has issues such as easy detachment and inability to adjust the light-blocking wavelength.

[0007] In summary, existing light-blocking technologies for PET packaging bottles generally suffer from the following drawbacks: (1) while blocking harmful light, they significantly reduce the transparency of the bottle, failing to balance light protection with the visibility of the contents; (2) they lack the ability to selectively block harmful light wavelengths, usually at the cost of sacrificing full-spectrum light transmittance; and (3) multi-layer or label solutions are complex, costly, and difficult to dynamically control. Therefore, there is an urgent need in this field for a PET packaging bottle that can selectively block harmful light wavelengths in the 300-600nm range without affecting the transmission of safe visible light above 650nm, while also requiring a mild manufacturing process suitable for industrial production and without affecting the original performance and appearance of the bottle. Summary of the Invention

[0008] The purpose of this invention is to provide a PET packaging bottle with wavelength selective reflection function and its preparation method, so as to solve the problems in the existing PET packaging bottle light blocking technology, which cause a significant decrease in the transparency of the bottle due to the addition of colorants or absorbers, and cannot take into account both light protection and the visibility of the contents, as well as the defects of existing coating or label solutions, which are complex in process, have no adjustable light blocking wavelength, and have static and single function.

[0009] To achieve the above objectives, the present invention provides the following technical solution:

[0010] A PET packaging bottle with wavelength selective reflection function includes a bottle body and a wavelength selective reflection layer formed on at least a portion of the outer surface and / or inner surface of the bottle body;

[0011] The wavelength selective reflective layer has a micro-matrix structure, which is composed of a plurality of prism-shaped micro-reflective units arranged together to achieve directional reflection of harmful light bands in the wavelength range of 300-600nm, while allowing safe visible light with wavelengths above 650nm to pass through.

[0012] The wavelength selective reflective layer is formed directly on the surface of the pre-formed PET bottle through a plasma deposition process, and the thickness of the wavelength selective reflective layer is 50-500nm.

[0013] As a preferred embodiment of the present invention, the wavelength selective reflective layer has a reflectivity of ≥92% for light in the wavelength range of 300-600nm and a transmittance of ≥85% for light in the wavelength range of 650nm and above.

[0014] As a preferred embodiment of the present invention, the prism-shaped micro-reflection unit is a million-level prism micro-matrix structure, and each prism-shaped micro-reflection unit has a set tilt angle and arrangement spacing to achieve selective directional reflection of light in different wavelength ranges of 300-600nm.

[0015] As a preferred embodiment of the present invention, the plasma deposition process is plasma-enhanced chemical vapor deposition or magnetron sputtering deposition, with a deposition temperature of 30-80℃ and a deposition pressure of 0.1-10Pa.

[0016] As a preferred embodiment of the present invention, the wavelength selective reflective layer is a multilayer dielectric thin film structure, which is formed by alternating stacking of high refractive index material layers and low refractive index material layers. The high refractive index material is selected from one or more of TiO2, Ta2O5, and Nb2O5, and the low refractive index material is selected from one or more of SiO2 and MgF2.

[0017] As a preferred embodiment of the present invention, the wavelength selective reflective layer is further dispersed with photodeformable microcapsules, which undergo reversible volume expansion when irradiated with harmful light of 300-600nm to drive the tilt angle of the prism-shaped microreflective unit to change dynamically; when the intensity of harmful light exceeds a preset threshold, the micro-matrix structure switches from directional reflection mode to scattering reflection mode.

[0018] The present invention also provides a method for preparing the PET packaging bottle as described above, comprising the following steps:

[0019] S1: Provide a pre-formed PET bottle body, and perform surface cleaning and plasma pretreatment on the PET bottle body;

[0020] S2: The pretreated PET bottle is placed in the deposition chamber, and a wavelength selective reflective layer precursor is deposited on at least a portion of the surface of the PET bottle using a plasma deposition process.

[0021] S3: By controlling the deposition process parameters, the wavelength selective reflective layer precursor is made to self-assemble into a micro-matrix structure, which is composed of a plurality of prism-shaped micro-reflective units.

[0022] S4: Post-process the deposited PET bottle to obtain a finished PET packaging bottle with wavelength selective reflection function.

[0023] As a preferred embodiment of the preparation method of the present invention, in step S2, before depositing the wavelength-selective reflective layer precursor, a transition adhesion layer is first deposited on the surface of the PET bottle. The material of the transition adhesion layer is SiO2 or Al2O3, and the thickness is 5-20nm.

[0024] As a preferred embodiment of the preparation method of the present invention, in step S3, the formation of the micro-matrix structure is achieved by external electric field or magnetic field assisted induction, and a bias voltage is applied to the PET bottle during the deposition process, with a bias voltage value of -50V to -200V.

[0025] As a preferred embodiment of the preparation method of the present invention, in step S3, the process of self-assembly to form a micro-matrix structure includes: introducing photodeformable microcapsule precursor vapor into the deposition cavity and co-depositing it with the main deposition material; by controlling the deposition temperature gradient to 5-15℃ / cm, the prism-shaped micro-reflective units are oriented to grow along the temperature gradient direction during the growth process, while the photodeformable microcapsules are in situ encapsulated in the gaps between adjacent prism-shaped micro-reflective units, forming a composite micro-matrix structure with alternating prisms and microcapsules.

[0026] The beneficial effects of this invention include:

[0027] (1) The present invention achieves efficient reflection of harmful light of 300-600nm by means of directional reflection design of prism-shaped micro-reflection unit without adding any colorant or absorber, while allowing high transmittance of safe visible light above 650nm. It achieves selective blocking of harmful light while maintaining high transparency of bottle body, effectively solving the problem of reduced transparency of bottle body and inability to balance light blocking and visibility of contents caused by the addition of colorant, absorber or inorganic filler in the prior art.

[0028] (2) The present invention adopts plasma-enhanced chemical vapor deposition or magnetron sputtering deposition process, and the deposition temperature is controlled at 30-80℃. It can be directly processed on the surface of the already formed PET bottle, avoiding thermal deformation or performance degradation caused by high temperature to the bottle. It does not require changing the original bottle forming process, and solves the problems of large equipment investment, complex process, high defect rate, easy label removal, high cost, and non-adjustable light blocking band of the existing multi-layer co-injection scheme.

[0029] (3) The wavelength selection reflective layer of the present invention has a thickness of only 50-500nm, which is a nano-scale thin film. It has minimal impact on the original appearance, transparency, weight and feel of the bottle, and does not affect subsequent filling, labeling, transportation and other processes, nor does it affect the recyclability of the PET bottle.

[0030] (4) By dispersing photodeformation microcapsules in a wavelength-selective reflective layer, the present invention enables the micro-matrix structure to automatically switch from directional reflection mode to scattering reflection mode when the intensity of harmful light exceeds a preset threshold, thereby realizing intelligent dynamic response control of light protection and solving the problem that existing light blocking solutions are all static protection and cannot dynamically adjust the protection level according to the intensity of light.

[0031] (5) This invention utilizes the self-assembly effect and external field-assisted induction during the plasma deposition process to efficiently form a regular micro-matrix structure on a large-area, non-planar bottle surface without the need for secondary processing of the bottle. The process steps are simple, the production efficiency is high, and it is suitable for industrial-scale production. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0033] Example 1

[0034] 1. Preparation and pretreatment of PET bottles

[0035] Take a pre-formed 500mL PET beverage bottle (wall thickness approximately 0.3mm) and ultrasonically clean it sequentially with deionized water and anhydrous ethanol for 15 minutes to remove surface oil and impurities. Then, place the bottle in a plasma treatment chamber and perform plasma pretreatment under an Ar atmosphere with a radio frequency power of 50W for 5 minutes to activate the bottle surface and improve the adhesion of subsequent deposited layers.

[0036] 2. Deposition of transition adhesion layer

[0037] A transition adhesion layer was deposited on the surface of a PET bottle using magnetron sputtering with SiO2 as the target. Deposition conditions were: Ar flow rate 30 sccm, working pressure 0.5 Pa, sputtering power 100 W, deposition time 3 min, and a film thickness of approximately 10 nm. The transition adhesion layer improves the adhesion between the PET substrate and the subsequent wavelength-selective reflective layer, preventing film detachment.

[0038] 3. Wavelength-selective reflective layer deposition

[0039] Plasma-enhanced chemical vapor deposition (PECVD) was used to deposit TiO2 / SiO2 multilayer dielectric films as wavelength-selective reflective layers on the surface of the transition adhesion layer. Deposition conditions were: substrate temperature 50℃, working gas pressure 1.0 Pa, and RF power 150 W. The TiO2 layer used TiCl4 and O2 as precursors, and the SiO2 layer used SiH4 and N2O as precursors. Multilayer stacking was achieved by alternating gas sources, with a total of 6 deposition cycles (TiO2 / SiO2 alternating) and a total thickness of approximately 200 nm.

[0040] During the deposition process, a -100V bias voltage and an auxiliary magnetic field (magnetic field strength 0.05T) are applied to the bottle to induce the film to self-assemble into a micro-matrix structure of prism-shaped micro-reflective units during growth. By controlling the deposition parameters, the tilt angle and spacing of the prism units can be adjusted to produce Bragg reflection effect on incident light in the wavelength range of 300-600nm.

[0041] 4. Post-processing

[0042] After deposition, the bottle is annealed under vacuum (80°C, 30 min) to eliminate internal stress in the film and stabilize the micro-matrix structure.

[0043] 5. Performance Testing

[0044] The reflectance and transmittance of the bottle in the 300-800 nm wavelength range were tested using a UV-Vis-NIR spectrophotometer (equipped with an integrating sphere attachment). The results showed that the average reflectance was 93.5% in the 300-600 nm wavelength range, and the average transmittance was 86.2% in the wavelength range above 650 nm. The bottle maintained good transparency, allowing visual observation of the contents. Furthermore, when the bottle was placed under simulated sunlight (including UV and visible light), the photosensitizer (riboflavin solution) inside the bottle showed no significant degradation within 24 hours, indicating that harmful light was effectively reflected.

[0045] Example 2

[0046] The difference between this embodiment and Embodiment 1 is that photodeformable microcapsules are also dispersed in the wavelength-selective reflective layer to achieve dynamic light modulation function.

[0047] 1. Preparation of photodeformable microcapsule precursors

[0048] Cross-linked polyacrylate containing azobenzene chromophores was dissolved in dichloromethane to prepare a solution, and microcapsules were prepared by spray drying. The microcapsules underwent cis-trans isomerization under ultraviolet light (300-400 nm) irradiation, resulting in a volume expansion of approximately 15-20%; the expansion was reversible after the light source was removed.

[0049] 2. Co-deposition process

[0050] In the PECVD deposition process of step 3 in Example 1, the photodeformable microcapsule precursor was introduced into the deposition chamber in vapor form and reacted with TiO2. 2 / SiO2 as the main deposition material is co-deposited. A temperature gradient (10℃ / cm along the axial direction of the bottle) is set in the deposition chamber, so that the prism-shaped micro-reflective units grow in a directional manner along the temperature gradient direction during the growth process. At the same time, photodeformable microcapsules are encapsulated in situ in the gaps between adjacent prism units, forming a composite micro-matrix structure with alternating prisms and microcapsules.

[0051] 3. Performance Testing

[0052] Under normal illumination (harmful light intensity < preset threshold), the composite micromatrix maintains a directional reflection mode, with a reflectivity of ≥92% for harmful light in the 300-600nm range. When the harmful light intensity exceeds the threshold (e.g., direct sunlight), the photodeformable microcapsules expand, compressing adjacent prism units and causing a dynamic change in their tilt angle. The micromatrix structure switches to a scattering reflection mode, scattering the incident light in all directions, further reducing the risk of harmful light penetrating the contents. After the strong light irradiation is removed, the microcapsule volume recovers, and the micromatrix structure reversibly switches back to the directional reflection mode.

[0053] Dynamic response tests show that the optical modulation response time of the composite micro-matrix structure is <5s, and its performance does not significantly degrade after 100 cycles of testing, demonstrating excellent reversibility and durability.

[0054] Example 3

[0055] This embodiment provides a batch preparation scheme suitable for industrial-scale production.

[0056] Multiple pre-formed PET bottles are loaded onto a rotating sample stage and fed into a large PECVD deposition chamber. The sample stage can rotate along a horizontal axis to ensure uniform deposition across all parts of the bottle. A linear plasma source is arranged along the axial direction of the sample stage to achieve large-area uniform deposition. Deposition parameters are the same as in Example 1, and a single batch can process ≥100 bottles with a deposition cycle of approximately 20-30 minutes.

[0057] The batch-produced bottles were sampled and tested, and the batch-to-batch deviation of reflectance and transmittance was <2%, indicating that the process has good stability and repeatability.

[0058] Example 4

[0059] The difference between this embodiment and Embodiment 1 is that a magnetron sputtering process is used instead of a PECVD process to deposit a wavelength-selective reflective layer.

[0060] A magnetron sputtering process was employed, using Ti and Si targets as the target materials, to reactively deposit TiO2 / SiO2 multilayer dielectric films in an Ar / O2 mixed atmosphere. Deposition conditions were: substrate temperature 60℃, working pressure 0.8 Pa, Ar flow rate 40 sccm, O2 flow rate 15 sccm, Ti target sputtering power 150 W, and Si target sputtering power 120 W. Six deposition cycles (alternating TiO2 / SiO2) were completed, with a total thickness of approximately 220 nm. During deposition, a -120 V bias voltage and an auxiliary electric field were applied to the vessel to induce the formation of a micro-matrix structure. Testing showed that the vessel exhibited an average reflectance of 92.8% in the 300-600 nm wavelength range and an average transmittance of 85.6% above 650 nm.

[0061] Comparative Example

[0062] To verify the technical effects of the present invention, the following comparative examples are provided:

[0063] Comparative Example 1

[0064] PET packaging bottles were manufactured by injection blow molding after adding 3 wt% UV absorber and 2 wt% TiO2 to PET raw materials using a melt blending method. The bottle exhibited a transmittance of <5% in the 300-600nm wavelength range, but the transmittance also dropped to <30% in wavelengths above 650nm, resulting in a white, cloudy appearance that prevented visual inspection of the contents. This demonstrates that light-blocking methods that sacrifice transparency cannot simultaneously ensure the visibility of the contents.

[0065] Comparative Example 2

[0066] Using the same PET bottle and deposition process as in Example 1, but without applying bias voltage and auxiliary magnetic field during deposition, the film grew randomly and did not form a regular micro-matrix structure. The bottle exhibited a reflectivity of only about 45% in the 300-600 nm wavelength range, with a significantly lower light blocking effect than Example 1, and a transmittance of 82.3% above 650 nm. This demonstrates that the micro-matrix structure is key to achieving wavelength-selective high reflectivity.

[0067] Comparative Example 3

[0068] The same PET bottle and deposition process as in Example 1 were used, but a single TiO2 layer was deposited instead of TiO2. 2 / A SiO2 multilayer dielectric film was deposited. A bias voltage and an auxiliary magnetic field were applied during the deposition process to form a prism-like microstructure. The resulting bottle exhibited an average reflectivity of only about 62% in the 300-600 nm wavelength range, significantly lower than Example 1, and a narrow reflection band, failing to adequately cover the entire 300-600 nm wavelength range. This demonstrates that the Bragg reflection effect of the multilayer dielectric film is crucial for achieving high reflectivity across a wide wavelength range.

[0069] Comparative Example 4

[0070] The same PET bottle and deposition process as in Example 1 were used, but the deposition temperature was increased to 120°C. During deposition, the bottle underwent significant thermal deformation, and the bottle mouth roundness exceeded the standard, failing to meet subsequent filling and sealing requirements. The bottle's mechanical properties decreased, with the drop ball impact strength reduced by approximately 35% compared to Example 1. This demonstrates that controlling the deposition temperature between 30-80°C is crucial for maintaining bottle performance in this invention.

[0071] Comparative Example 5

[0072] Using the same PET bottle and deposition process as in Example 1, but increasing the deposition cycle to 20 cycles, the total thickness of the reflective layer was approximately 650 nm. The bottle exhibited a reflectivity of 94.1% in the 300-600 nm wavelength range, but the transmittance above 650 nm dropped to 72.5%, significantly lower than in Example 1. This resulted in decreased bottle transparency, microcracks in the film layer, and reduced adhesion. This demonstrates that controlling the reflective layer thickness within the 50-500 nm range can maintain good transmittance and film stability while ensuring high reflectivity.

[0073] Comparative Example 6

[0074] The same PET bottle and deposition process as in Example 1 were used, but the deposition of the transition adhesion layer was omitted, and a wavelength-selective reflective layer was directly deposited on the plasma-pretreated PET bottle surface. Localized film peeling occurred immediately after deposition, and after 48 hours, the peeling area increased to approximately 30%, with an adhesion test (cross-cut test) grade of 3 (Example 1 was grade 1). This demonstrates that the establishment of the transition adhesion layer is crucial for ensuring the long-term bonding stability between the film and the PET substrate.

[0075] Summary table of performance comparison between examples and comparative examples

[0076]

[0077] As shown in the table above, all embodiments of the present invention achieve a balance between high reflectivity (≥92%) for harmful light in the 300-600nm range and high transmittance (≥85%) for safe visible light above 650nm, while maintaining bottle transparency and good film stability. In contrast, Comparative Examples 1-6 exhibit problems such as poor transparency, low reflectivity, bottle deformation, decreased transmittance, or poor film stability to varying degrees, verifying the necessity and superiority of the synergistic effect of the various technical features of the present invention.

[0078] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A PET packaging bottle with wavelength selective reflection function, characterized in that, Includes a bottle body and a wavelength selective reflective layer formed on at least a portion of the outer and / or inner surface of the bottle body; The wavelength selective reflective layer has a micro-matrix structure, which is composed of a plurality of prism-shaped micro-reflective units arranged together to achieve directional reflection of harmful light bands in the wavelength range of 300-600nm, while allowing safe visible light with wavelengths above 650nm to pass through. The wavelength selective reflective layer is formed directly on the surface of the pre-formed PET bottle through a plasma deposition process, and the thickness of the wavelength selective reflective layer is 50-500nm.

2. The PET packaging bottle according to claim 1, characterized in that, The wavelength selective reflective layer has a reflectivity of ≥92% for light in the 300-600nm wavelength range and a transmittance of ≥85% for light in the wavelength range above 650nm.

3. The PET packaging bottle according to claim 1, characterized in that, The prism-shaped micro-reflection unit is a million-level prism micro-matrix structure. Each prism-shaped micro-reflection unit has a set tilt angle and arrangement spacing to achieve selective directional reflection of light in different wavelength ranges of 300-600nm.

4. The PET packaging bottle according to claim 1, characterized in that, The plasma deposition process is plasma-enhanced chemical vapor deposition or magnetron sputtering deposition, with a deposition temperature of 30-80℃ and a deposition pressure of 0.1-10Pa.

5. The PET packaging bottle according to claim 1, characterized in that, The wavelength selective reflective layer is a multilayer dielectric thin film structure, which is composed of alternating layers of high refractive index material and low refractive index material. The high refractive index material is selected from one or more of TiO2, Ta2O5, and Nb2O5, and the low refractive index material is selected from one or more of SiO2 and MgF2.

6. The PET packaging bottle according to claim 1, characterized in that, The wavelength-selective reflective layer also contains photodeformable microcapsules, which undergo reversible volume expansion when exposed to harmful light of 300-600nm, thereby driving a dynamic change in the tilt angle of the prism-shaped micro-reflective unit. When the intensity of the harmful light exceeds a preset threshold, the micro-matrix structure switches from directional reflection mode to scattering reflection mode.

7. A method for preparing a PET packaging bottle as described in any one of claims 1-6, characterized in that, Includes the following steps: S1: Provide a pre-formed PET bottle body, and perform surface cleaning and plasma pretreatment on the PET bottle body; S2: The pretreated PET bottle is placed in the deposition chamber, and a wavelength selective reflective layer precursor is deposited on at least a portion of the surface of the PET bottle using a plasma deposition process. S3: By controlling the deposition process parameters, the wavelength selective reflective layer precursor is made to self-assemble into a micro-matrix structure, which is composed of a plurality of prism-shaped micro-reflective units. S4: Post-process the deposited PET bottle to obtain a finished PET packaging bottle with wavelength selective reflection function.

8. The preparation method according to claim 7, characterized in that, In step S2, before depositing the wavelength-selective reflective layer precursor, a transition adhesion layer is first deposited on the surface of the PET bottle. The transition adhesion layer is made of SiO2 or Al2O3 and has a thickness of 5-20 nm.

9. The preparation method according to claim 7, characterized in that, In step S3, the formation of the micro-matrix structure is achieved by external electric or magnetic field-assisted induction. During the deposition process, a bias voltage of -50V to -200V is applied to the PET bottle.

10. The preparation method according to claim 7, characterized in that, In step S3, the process of self-assembly to form a micro-matrix structure includes: introducing photodeformable microcapsule precursor vapor into the deposition chamber and co-depositing it with the main deposition material; by controlling the deposition temperature gradient to 5-15℃ / cm, the prism-shaped micro-reflective units are oriented to grow along the temperature gradient direction during the growth process, while the photodeformable microcapsules are in situ encapsulated in the gaps between adjacent prism-shaped micro-reflective units, forming a composite micro-matrix structure with alternating prisms and microcapsules.

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