Waterproof and antioxidant nuclear medicine dry printing film and preparation method thereof

Abstract

The invention discloses a waterproof and antioxidant nuclear medicine dry printing film and a preparation method thereof, and relates to the technical field of printing films. The printing film adopts a three-layer structure of a bottom coating, a nuclear-sensitive imaging layer and a waterproof anti-oxidation layer. The preparation method comprises the following steps: pretreating a PET film, and coating and curing each coating. The bottom coating liquid contains hydroxyl acrylic resin, an isocyanate curing agent, nano silicon dioxide particles and ethyl acetate, and the core-sensitive imaging layer coating liquid takes gelatin and silver bromide as cores and is added with benzotriazole, sodium sulfite, polyethylene glycol diglycidyl ether and a fluorocarbon surfactant. The waterproof anti-oxidation coating liquid is prepared from polyvinylidene fluoride resin, an ethylene trifluorochloroethylene copolymer, nano titanium oxide particles and the like. The printing film has excellent surface performance, high image resolution and good long-term storage stability, and can meet the requirements of nuclear medicine clinical diagnosis and long-term archiving.

Description

Technical Field

[0001] This invention relates to the field of printing film technology, specifically to a waterproof, oxidation-resistant nuclear medicine dry printing film and its preparation method. Background Technology

[0002] Nuclear medicine dry printing films serve as a crucial medium for medical image storage and diagnosis, and their performance directly impacts the accuracy of diagnostic results and the long-term usability of images. With the continuous development of nuclear medicine diagnostic technology, clinicians are placing higher demands on the imaging clarity, environmental tolerance, and storage stability of these films. These films need to be used frequently in complex clinical environments while simultaneously meeting the requirements of long-term archiving without fading or deformation; therefore, water resistance, oxidation resistance, and structural stability have become core performance indicators.

[0003] Currently available nuclear medicine dry printing films generally suffer from limited functionality and insufficient overall performance. While some films can meet basic imaging requirements, they are prone to image fading and haze growth in humid or oxidizing environments, leading to distorted diagnostic information and failing to meet long-term archiving requirements. Furthermore, insufficient adhesion between the film's coatings makes them susceptible to delamination and peeling during daily operation, transportation, or storage, further impacting their reliability and lifespan.

[0004] Furthermore, the surface properties of existing films are not well-designed; some products have rough surfaces or are prone to static electricity, which not only affects the smoothness of paper feeding during printing but may also lead to printing defects, reducing image resolution and appearance quality. These shortcomings make it difficult for existing films to simultaneously achieve high image quality, excellent environmental resistance, and good handling performance, failing to meet the stringent requirements of nuclear medicine clinical diagnosis and long-term archiving. Therefore, developing a waterproof and oxidation-resistant nuclear medicine dry printing film with balanced comprehensive performance is of significant practical importance. Summary of the Invention

[0005] To address the problems mentioned in the background section, this invention provides a waterproof, oxidation-resistant nuclear medicine dry printing film and its preparation method.

[0006] In a first aspect, the present invention provides a method for preparing a waterproof and antioxidant nuclear medicine dry printing film, comprising the following steps: Step S1: Take a PET film, and after ultrasonic cleaning, drying, and corona treatment, prepare a primer and apply it to one side of the PET film, then cure it to form a primer layer. Step S2: Apply the nuclear-sensitive imaging layer coating liquid to the surface of the base layer prepared in step S1, and cure it by pre-drying and hot air drying to form the nuclear-sensitive imaging layer; Step S3: Apply a waterproof and antioxidant coating liquid to the surface of the nuclear-sensitive imaging layer prepared in step S2, and then dry and cure it at high temperature to form a waterproof and antioxidant layer. Subsequently, perform calendering treatment to obtain a waterproof and antioxidant nuclear medicine dry printing film.

[0007] Furthermore, the conditions for ultrasonic cleaning in step S1 are: ultrasonic power 300W-500W, cleaning temperature 30℃-40℃, and cleaning time 15min-25min.

[0008] Furthermore, the drying conditions in step S1 are: hot air drying temperature of 60℃-80℃ and drying time of 20min-30min.

[0009] Furthermore, the conditions for corona treatment in step S1 are: corona power 30W / m²-50W / m², and treatment speed 10m / min-20m / min.

[0010] Furthermore, in step S1, the coating thickness of the primer is 5μm-10μm; the curing conditions of the primer are: curing temperature 80℃-100℃, curing time 15min-25min.

[0011] Furthermore, in step S2, the coating thickness of the nuclear-sensitive imaging layer coating liquid is 20μm-30μm; the pre-drying conditions are: pre-drying temperature 45℃-55℃, pre-drying time 8min-12min; the hot air drying conditions are: drying at 60℃-70℃ for 35min-50min.

[0012] Furthermore, in step S3, the coating thickness of the waterproof and antioxidant coating liquid is 8μm-15μm; the drying conditions are: drying at 60℃-70℃ for 20min-35min; the high-temperature curing conditions are: curing temperature 120℃-140℃, curing time 25min-35min, and inert gas is introduced for protection during the curing process.

[0013] Further, the calendering process in step S3 is as follows: the object is placed in a temperature-controlled calender and calendered at a constant speed for 3 min to 5 min under the conditions of temperature 80℃-90℃ and pressure 0.3MPa-0.5MPa, and then naturally cooled to room temperature.

[0014] Furthermore, the primer is prepared by mixing and stirring hydroxyl acrylic resin, isocyanate curing agent, nano silica particles and ethyl acetate.

[0015] Furthermore, the weight proportions of each raw material in the primer liquid are as follows: 30-40 parts of hydroxyl acrylic resin, 8-12 parts of isocyanate curing agent, 3-6 parts of nano silica particles, and 45-60 parts of ethyl acetate.

[0016] Furthermore, the preparation method of the nuclear-sensitive imaging layer coating solution is as follows: Gelatin, silver bromide, benzotriazole, and sodium sulfite were added to deionized water, stirred, heated, and kept warm to disperse the mixture. Then, a crosslinking agent and a fluorocarbon surfactant were added, and stirring was continued. The mixture was then ultrasonically degassed to obtain the nuclear-sensitive imaging layer coating solution.

[0017] Furthermore, the weight proportions of each raw material in the nuclear-sensitive imaging layer coating solution are as follows: 90-110 parts deionized water, 12-18 parts gelatin, 6-10 parts silver bromide, 1-3 parts benzotriazole, 2-4 parts sodium sulfite, 2-4 parts crosslinking agent, and 0.3-0.7 parts fluorocarbon surfactant; wherein the crosslinking agent is polyethylene glycol diglycidyl ether.

[0018] Furthermore, the stirring and heating temperature is 40℃-50℃, the heat preservation and dispersion time is 50min-70min, the stirring time after adding the crosslinking agent and fluorocarbon surfactant is 25min-35min, and the ultrasonic degassing time is 15min-25min.

[0019] Furthermore, the waterproof and antioxidant coating liquid is prepared by mixing and stirring polyvinylidene fluoride resin, ethylene trifluorochloroethylene copolymer, nano titanium dioxide particles, isocyanate curing agent, hindered phenolic antioxidant and N,N-dimethylformamide.

[0020] Furthermore, the weight proportions of each raw material in the waterproof and antioxidant coating liquid are as follows: 25-35 parts of polyvinylidene fluoride resin, 15-25 parts of ethylene trifluorochloroethylene copolymer, 4-8 parts of nano titanium dioxide particles, 6-10 parts of isocyanate curing agent, 2-5 parts of hindered phenolic antioxidant, and 30-45 parts of N,N-dimethylformamide.

[0021] On the other hand, the present invention provides a waterproof and antioxidant nuclear medicine dry printing film prepared by the above-described method for preparing a waterproof and antioxidant nuclear medicine dry printing film.

[0022] The beneficial effects of this invention are: 1. This invention achieves precise matching and synergistic enhancement of the performance of each layer by constructing a multi-layer composite functional structure consisting of a base layer, a nuclear-sensitive imaging layer, and a waterproof and antioxidant layer. This structure not only ensures excellent adhesion between layers, avoiding the risk of peeling during use, but also enables the film to achieve environmental tolerance exceeding that of conventional products while maintaining high image quality, thereby meeting the stringent requirements of nuclear medicine imaging for long-term archiving stability.

[0023] 2. The nuclear-sensitive imaging layer of this invention employs a formulation system composed of specific substances such as benzotriazole and polyethylene glycol diglycidyl ether. This system, while ensuring the photosensitivity of silver halide, significantly improves the chemical stability and physical strength within the imaging layer, effectively suppressing the fogging and image quality degradation commonly seen in humid and hot environments, thus laying a solid foundation for obtaining high-resolution, high-fidelity diagnostic images.

[0024] 3. The waterproof and antioxidant layer of this invention uses a specific fluororesin blend as a matrix, compounded with functional particles such as nano-titanium oxide, and is cured at high temperature to form a dense protective barrier. This protective barrier can effectively block the penetration of media such as water vapor and oxygen, and endows the coating with good chemical resistance and UV aging resistance, thereby providing durable and comprehensive protection for the internal precision imaging layer, fundamentally extending the service life and reliability of the printing film. Detailed Implementation

[0025] To make the implementation methods of this application easier to understand, the application will be described in detail below with reference to specific embodiments. These embodiments are for illustrative purposes only and are not limited to the application scope of this application.

[0026] The specific parameters of the raw materials used in this invention are as follows: In the examples below, the PET film is a black PET film, purchased from Dongguan Yanming Plastics Trading Co., Ltd.

[0027] In the examples below, the hydroxyl acrylic resin is a thermoplastic product with an active ingredient content of 55%, purchased from Hanbote Coatings (Shandong) Co., Ltd.

[0028] In the examples below, the isocyanate curing agent is a blocked isocyanate curing agent, purchased from Wuhan Kemic Biomedical Technology Co., Ltd.

[0029] In the examples below, the nano-silica particles had a particle size of 20 nm and were purchased from Qinghe County Ruijiang Metal Materials Co., Ltd.

[0030] The silver bromide used in the following examples has a CAS number of 7785-23-1 and was purchased from Wuhan Huaxiang Kejie Biotechnology Co., Ltd.

[0031] Benzotriazole in the following examples is a white needle-like crystal, purchased from Langfang Qianyao Technology Co., Ltd.

[0032] In the examples below, the CAS number of polyethylene glycol diglycidyl ether is 39443-66-8, which was purchased from Shandong Lifan Chemical Co., Ltd.

[0033] In the examples below, the fluorocarbon surfactant is 626 fluorocarbon surfactant, which was purchased from Wuhan Beileye Biomedical Technology Co., Ltd.

[0034] In the examples below, the polyvinylidene fluoride resin used was DS206, purchased from Dongguan Hechuang Plastics Co., Ltd.

[0035] The ethylene trifluorochloroethylene copolymer in the following examples is grade 6914GY (powder), purchased from Dongguan Yingxiang Plastic Raw Materials Co., Ltd.

[0036] The nano-titanium oxide particles in the following examples have a particle size of 10 nm and were purchased from Suzhou Beike Nanotechnology Co., Ltd.

[0037] In the examples below, the hindered phenolic antioxidant is antioxidant 1010, CAS number 6683-19-8, purchased from Nanjing Milan Chemical Co., Ltd.

[0038] The polyvinyl chloride resin used in the comparative examples below has a CAS registry number of 9002-86-2 and was purchased from Jinan Dahui Chemical Technology Co., Ltd.

[0039] Example 1 A method for preparing a waterproof and oxidation-resistant nuclear medicine dry printing film includes the following steps: Preparation of primer: Weigh the following raw materials according to the following parts by weight: 30 parts of hydroxyl acrylic resin, 8 parts of isocyanate curing agent, 3 parts of nano silica particles, and 45 parts of ethyl acetate. Mix the above raw materials and stir evenly to obtain the primer liquid. Preparation of the coating solution for the nuclear-sensitive imaging layer: Weigh the following raw materials according to weight: 90 parts deionized water, 12 parts gelatin, 6 parts silver bromide, 1 part benzotriazole, 2 parts sodium sulfite, 2 parts polyethylene glycol diglycidyl ether, and 0.3 parts fluorocarbon surfactant. Add gelatin, silver bromide, benzotriazole, and sodium sulfite to deionized water, stir and heat to 40°C, keep warm and disperse for 50 min, add polyethylene glycol diglycidyl ether and 626 fluorocarbon surfactant, continue stirring for 25 min, and finally degas at room temperature for 15 min with ultrasonic power of 180 W and ultrasonic frequency of 20 kHz to obtain the nuclear sensitive imaging layer coating solution. Preparation of waterproof and antioxidant coating liquid: Weigh the following raw materials according to the following weight: 25 parts of polyvinylidene fluoride resin, 15 parts of ethylene trifluorochloroethylene copolymer, 4 parts of nano titanium dioxide particles, 6 parts of isocyanate curing agent, 2 parts of antioxidant 1010, and 30 parts of N,N-dimethylformamide. Mix the above raw materials and stir evenly to obtain a waterproof and antioxidant coating liquid. Step S1: Take a black PET film, clean it in deionized water with an ultrasonic power of 300W and a cleaning temperature of 30℃ for 15 minutes, dry it in hot air at a temperature of 60℃ for 20 minutes, perform corona treatment with a corona power of 30W / m² and a processing speed of 10m / min, apply the prepared primer liquid to one side of the PET film, control the coating thickness to 5μm, and then cure it at a curing temperature of 80℃ for 15 minutes to form a primer coating. Step S2: Coat the nuclear-sensitive imaging layer coating liquid onto the surface of the base coating layer obtained in step S1. The coating thickness is controlled at 20 μm. First, pre-dry for 8 min at a temperature of 45°C, and then hot-dry for 35 min at a temperature of 60°C to form the nuclear-sensitive imaging layer. Step S3: Apply the waterproof and antioxidant coating liquid to the surface of the nuclear-sensitive imaging layer obtained in step S2, with the coating thickness controlled at 8 μm. First, dry it at 60°C for 20 min; then, under nitrogen protection, cure it at 120°C for 25 min to form a waterproof and antioxidant layer. Place it in a temperature-controlled calender and calender it at a uniform speed for 3 min under the conditions of 80°C and 0.3 MPa. After treatment, allow it to cool naturally to room temperature to obtain a waterproof and antioxidant nuclear medicine dry printing film.

[0040] Example 2 A method for preparing a waterproof and oxidation-resistant nuclear medicine dry printing film includes the following steps: Preparation of primer: Weigh the following raw materials according to the following parts by weight: 35 parts of hydroxy acrylic resin, 10 parts of isocyanate curing agent, 4 parts of nano silica particles, and 52 parts of ethyl acetate. Mix the above raw materials and stir evenly to obtain the primer liquid. Preparation of the coating solution for the nuclear-sensitive imaging layer: Weigh the following raw materials according to weight: 100 parts deionized water, 15 parts gelatin, 8 parts silver bromide, 2 parts benzotriazole, 3 parts sodium sulfite, 3 parts polyethylene glycol diglycidyl ether, and 0.5 parts fluorocarbon surfactant. Add gelatin, silver bromide, benzotriazole, and sodium sulfite to deionized water, stir and heat to 45°C, keep warm and disperse for 60 min, add polyethylene glycol diglycidyl ether and 626 fluorocarbon surfactant, continue stirring for 30 min, and finally degas at room temperature for 20 min with ultrasonic power of 250 W and ultrasonic frequency of 30 kHz to obtain the nuclear sensitive imaging layer coating solution. Preparation of waterproof and antioxidant coating liquid: Weigh the following raw materials by weight: 30 parts polyvinylidene fluoride resin, 20 parts ethylene trifluorochloroethylene copolymer, 6 parts nano titanium dioxide particles, 8 parts isocyanate curing agent, 4 parts antioxidant 1010, and 37 parts N,N-dimethylformamide. Mix the above raw materials and stir evenly to obtain a waterproof and antioxidant coating liquid. Step S1: Take a black PET film, clean it in deionized water with an ultrasonic power of 400W and a cleaning temperature of 35℃ for 20 minutes, dry it in hot air at a temperature of 70℃ for 25 minutes, perform corona treatment with a corona power of 40W / m² and a processing speed of 15m / min, apply the prepared primer liquid to one side of the PET film, control the coating thickness to 7μm, and then cure it at a curing temperature of 90℃ for 20 minutes to form a primer layer. Step S2: Coat the nuclear-sensitive imaging layer coating liquid onto the surface of the base coating layer obtained in step S1. The coating thickness is controlled at 25 μm. First, pre-dry for 10 min at a temperature of 50°C, and then hot-dry for 42 min at a temperature of 65°C to form the nuclear-sensitive imaging layer. Step S3: Apply the waterproof and antioxidant coating liquid to the surface of the nuclear-sensitive imaging layer obtained in step S2, with the coating thickness controlled at 12 μm. First, dry it at 65°C for 27 min; then, under nitrogen protection, cure it at 130°C for 30 min to form a waterproof and antioxidant layer. Place it in a temperature-controlled calender and calender it at a constant speed for 4 min under the conditions of 85°C and 0.4 MPa. After treatment, allow it to cool naturally to room temperature to obtain a waterproof and antioxidant nuclear medicine dry printing film.

[0041] Example 3 A method for preparing a waterproof and oxidation-resistant nuclear medicine dry printing film includes the following steps: Preparation of primer: Weigh the following raw materials according to the following parts by weight: 40 parts of hydroxyl acrylic resin, 12 parts of isocyanate curing agent, 6 parts of nano silica particles, and 60 parts of ethyl acetate. Mix the above raw materials and stir evenly to obtain the primer liquid. Preparation of the coating solution for the nuclear-sensitive imaging layer: Weigh the following raw materials according to weight: 110 parts deionized water, 18 parts gelatin, 10 parts silver bromide, 3 parts benzotriazole, 4 parts sodium sulfite, 4 parts polyethylene glycol diglycidyl ether, and 0.7 parts fluorocarbon surfactant. Add gelatin, silver bromide, benzotriazole, and sodium sulfite to deionized water, stir and heat to 50°C, keep warm and disperse for 70 min, add polyethylene glycol diglycidyl ether and 626 fluorocarbon surfactant, continue stirring for 35 min, and finally degas at room temperature for 25 min with ultrasonic power of 300 W and ultrasonic frequency of 240 kHz to obtain the nuclear sensitive imaging layer coating solution. Preparation of waterproof and antioxidant coating liquid: Weigh the following raw materials by weight: 35 parts polyvinylidene fluoride resin, 25 parts ethylene trifluorochloroethylene copolymer, 8 parts nano titanium dioxide particles, 10 parts isocyanate curing agent, 5 parts antioxidant 1010, and 45 parts N,N-dimethylformamide. Mix the above raw materials and stir evenly to obtain a waterproof and antioxidant coating liquid. Step S1: Take a black PET film, clean it in deionized water with an ultrasonic power of 500W and a cleaning temperature of 40℃ for 25 minutes, dry it in hot air at a temperature of 80℃ for 30 minutes, perform corona treatment with a corona power of 50W / m² and a processing speed of 20m / min, apply the prepared primer liquid to one side of the PET film, control the coating thickness to 10μm, and then cure it at a curing temperature of 100℃ for 25 minutes to form a primer layer. Step S2: Coat the nuclear-sensitive imaging layer coating liquid onto the surface of the base coating layer obtained in step S1. The coating thickness is controlled at 30 μm. First, pre-dry for 12 min at a temperature of 55°C, and then hot-dry for 50 min at a temperature of 70°C to form the nuclear-sensitive imaging layer. Step S3: Apply the waterproof and antioxidant coating liquid to the surface of the nuclear-sensitive imaging layer obtained in step S2, with the coating thickness controlled at 15 μm. First, dry it at 70°C for 35 min; then, under nitrogen protection, cure it at 140°C for 35 min to form a waterproof and antioxidant layer. Place it in a temperature-controlled calender and calender it at a constant speed for 5 min under the conditions of 90°C and 0.5 MPa. After treatment, allow it to cool naturally to room temperature to obtain a waterproof and antioxidant nuclear medicine dry printing film.

[0042] Comparative Example 1 Compared with Example 1, this comparative example did not add "benzotriazole" to the nuclear-sensitive imaging layer coating solution. All other steps and parameters were the same, and will not be repeated here. Finally, a waterproof and antioxidant nuclear medicine dry printing film was obtained.

[0043] Comparative Example 2 Compared with Example 1, this comparative example replaces "polyethylene glycol diglycidyl ether" in the nuclear-sensitive imaging layer coating solution with an equal mass of "glycerol". All other steps and parameters are the same, and will not be repeated here. The final result is a waterproof and antioxidant nuclear medicine dry printing film.

[0044] Comparative Example 3 Compared with Example 1, this comparative example did not add "nano titanium dioxide particles" to the waterproof and antioxidant coating liquid. All other steps and parameters were the same, and will not be repeated here. Finally, a waterproof and antioxidant nuclear medicine dry printing film was obtained.

[0045] Comparative Example 4 Compared with Example 1, the "ethylene trifluorochloroethylene copolymer" in the waterproof and antioxidant coating liquid was replaced with an equal mass of "polyvinyl chloride resin". All other steps and parameters were the same, and will not be repeated in this comparative example. Finally, a waterproof and antioxidant nuclear medicine dry printing film was obtained.

[0046] The performance of the waterproof and antioxidant nuclear medicine dry printing films prepared in Examples 1-3 and the waterproof and antioxidant nuclear medicine dry printing films prepared in Comparative Examples 1-4 were tested, and the results are recorded in Table 1.

[0047] Testing methods for waterproof and oxidation-resistant nuclear medicine dry printing films: 1. Surface resistance detection: Standard based on: GB / T 1410-2006; Testing conditions: Temperature 23±2℃, Humidity 50±5%RH; Testing instrument: High resistance meter (model: ZC36); Testing steps: Cut the waterproof and antioxidant nuclear medicine dry printing films prepared in Examples 1-3 and Comparative Examples 1-4 into 100mm×100mm samples, place them on metal electrodes, apply a 500V DC voltage, and read the surface resistance value after stabilizing for 1 minute. Test 3 different positions for each sample and take the average value.

[0048] 2. Appearance quality inspection: Testing conditions: White light source (illuminance 500 lx), viewing distance 30 cm; Inspection content: Observe whether there are defects such as crystal points, white spots, streaks, bubbles, shrinkage cavities, etc. on the film surface, and count the number of defects (unit: pieces / m²).

[0049] 3. Image resolution detection Testing instrument: Image resolution tester (model: VTS-8000); Testing steps: Using a standard test chart with known pixels (9600×2400dpi), print it onto film using a nuclear medicine laser printer, scan the printed image using a resolution tester, and calculate the actual horizontal / vertical resolution.

[0050] 4. Waterproof performance test: Testing instrument: Hydrostatic pressure tester (Model: YG825B) Testing steps: Cut the waterproof and antioxidant nuclear medicine dry printing films prepared in Examples 1-3 and Comparative Examples 1-4 into 150mm×150mm samples, fix them on the testing device, apply water pressure to the waterproof and antioxidant layer side at a rate of 1kPa / s, and record the maximum hydrostatic pressure when water seepage occurs on the film.

[0051] 5. Imaging stability test: Test conditions: Accelerated aging environment (temperature 45℃, humidity 75%RH), placed for 30 days.

[0052] Testing instruments: Densitometer (model: X-Rite530), standard test chart: including full black, full white and multi-level grayscale areas.

[0053] Sample preparation: Cut the films prepared in Examples 1-3 and Comparative Examples 1-4 into 3 pieces of 100mm×100mm each. Use a nuclear medicine laser printer to print standard test charts (including all-black, all-white and multi-level grayscale areas) on each sample. After printing, the samples are equilibrated for 24 hours at a temperature of 23℃±2℃ and a humidity of 50%±5%RH.

[0054] Testing steps: Step 1: Density measurement before aging Using a densitometer, measure the following areas of each sample three times and take the average value: record the completely black area as Dmax0 (black density before aging), record the completely white area as Dmin0 (white density before aging), and record the unexposed area as Dfog0 (fog density before aging).

[0055] Step 2: Accelerated aging treatment The samples were suspended in the aging chamber to avoid contact with each other. The aging conditions were set as follows: temperature 45℃, humidity 75%RH, for 30 days. After aging, the samples were taken out and equilibrated at 23℃ and 50%RH for 24 hours.

[0056] Step 3: Density measurement after aging Repeat the measurement in step 1 at the same measurement location and record: Dmax t (Black density after aging), Dmin t (White density after aging), Dfog t (Density of fog after aging).

[0057] The rate of change of density is calculated using the following formula: The test results are shown in Table 1.

[0058] Table 1: Test Results of Waterproof and Antioxidant Nuclear Medicine Dry Printing Films According to the data in Table 1, the waterproof and antioxidant nuclear medicine dry printing films prepared in Examples 1-3 all exhibit excellent and balanced comprehensive characteristics in key properties such as surface resistance, apparent quality, image resolution, waterproof performance and imaging stability.

[0059] Comparing Comparative Example 1 with Example 1, it is evident that the absence of benzotriazole in the nuclear-sensitive imaging layer resulted in a significant decrease in film surface resistivity, an increase in apparent defects, a decline in image resolution, and a substantial increase in the rate of change of black, white, and fog densities after accelerated aging. Benzotriazole, as a stabilizer in the silver halide system, makes the nuclear-sensitive imaging layer more susceptible to unnecessary silver salt reduction and aggregation under hot and humid conditions, thereby degrading electrical performance, image clarity, and long-term storage stability.

[0060] Comparing Comparative Example 2 with Example 1, it can be seen that replacing the crosslinking agent polyethylene glycol diglycidyl ether with glycerol resulted in a comprehensive degradation of the film's properties. Although glycerol is hydrophilic, it cannot effectively crosslink with gelatin to form a stable three-dimensional network, leading to insufficient structural strength of the nuclear-sensor imaging layer, poor water resistance, and increased susceptibility to component migration and deformation during aging. This manifests as decreased water resistance, reduced resolution, and poor density stability.

[0061] Comparing Comparative Example 3 with Example 1, it is evident that the absence of nano-titanium oxide particles in the waterproof and antioxidant coating liquid had the most direct and severe negative impact on the waterproof performance of the film, resulting in a sharp decrease in hydrostatic pressure. The lack of nano-titanium oxide particles weakened the physical barrier and scattering effect of the waterproof and antioxidant layer against water vapor penetration. Simultaneously, it may have reduced the shielding effect of the waterproof and antioxidant layer against environmental factors such as ultraviolet radiation, making the base layer more susceptible to moisture and oxygen erosion, and consequently reducing imaging stability.

[0062] Comparing Comparative Example 4 with Example 1, it can be seen that after replacing the ethylene trifluorochloroethylene copolymer with polyvinyl chloride resin, the overall performance of the resulting film deteriorates. Polyvinyl chloride resin is far inferior to ethylene trifluorochloroethylene copolymer in terms of weather resistance, heat resistance, and compatibility with fluororesins. This results in insufficient density, adhesion, and long-term stability of the formed protective layer, which cannot effectively protect the internal imaging layer. Ultimately, this manifests as a comprehensive deterioration in waterproofness, insulation, and image durability.

[0063] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A method for preparing a waterproof, oxidation-resistant nuclear medicine dry printing film, characterized in that, Includes the following steps: Step S1: Take a PET film, and after ultrasonic cleaning, drying, and corona treatment, prepare a primer and apply it to one side of the PET film, then cure it to form a primer layer. Step S2: Apply the nuclear-sensitive imaging layer coating liquid to the surface of the base layer prepared in step S1, and cure it by pre-drying and hot air drying to form the nuclear-sensitive imaging layer; Step S3: Apply a waterproof and antioxidant coating liquid to the surface of the nuclear-sensitive imaging layer prepared in step S2, and then dry and cure it at high temperature to form a waterproof and antioxidant layer. Subsequently, perform calendering treatment to obtain a waterproof and antioxidant nuclear medicine dry printing film.

2. The method for preparing a waterproof and antioxidant nuclear medicine dry printing film according to claim 1, characterized in that, The primer is prepared by mixing and stirring hydroxyl acrylic resin, isocyanate curing agent, nano silica particles and ethyl acetate.

3. The method for preparing a waterproof and antioxidant nuclear medicine dry printing film according to claim 2, characterized in that, The weight proportions of each raw material in the primer are as follows: 30-40 parts of hydroxyl acrylic resin, 8-12 parts of isocyanate curing agent, 3-6 parts of nano silica particles, and 45-60 parts of ethyl acetate.

4. The method for preparing a waterproof and antioxidant nuclear medicine dry printing film according to claim 1, characterized in that, The preparation method of the nuclear-sensitive imaging layer coating solution is as follows: Gelatin, silver bromide, benzotriazole, and sodium sulfite were added to deionized water, stirred, heated, and kept warm to disperse the mixture. Then, a crosslinking agent and a fluorocarbon surfactant were added, and stirring was continued. The mixture was then ultrasonically degassed to obtain the nuclear-sensitive imaging layer coating solution.

5. The method for preparing a waterproof and antioxidant nuclear medicine dry printing film according to claim 4, characterized in that, The weight proportions of each raw material in the nuclear-sensitive imaging layer coating solution are as follows: 90-110 parts deionized water, 12-18 parts gelatin, 6-10 parts silver bromide, 1-3 parts benzotriazole, 2-4 parts sodium sulfite, 2-4 parts crosslinking agent, and 0.3-0.7 parts fluorocarbon surfactant; the crosslinking agent is polyethylene glycol diglycidyl ether.

6. The method for preparing a waterproof and antioxidant nuclear medicine dry printing film according to claim 4, characterized in that, The stirring and heating temperature is 40℃-50℃, the heat preservation and dispersion time is 50min-70min, the stirring time after adding the crosslinking agent and fluorocarbon surfactant is 25min-35min, and the ultrasonic degassing time is 15min-25min.

7. The method for preparing a waterproof and antioxidant nuclear medicine dry printing film according to claim 1, characterized in that, The waterproof and antioxidant coating liquid is prepared by mixing and stirring polyvinylidene fluoride resin, ethylene trifluorochloroethylene copolymer, nano titanium dioxide particles, isocyanate curing agent, hindered phenolic antioxidant and N,N-dimethylformamide.

8. The method for preparing a waterproof and antioxidant nuclear medicine dry printing film according to claim 7, characterized in that, The weight proportions of each raw material in the waterproof and antioxidant coating liquid are as follows: 25-35 parts of polyvinylidene fluoride resin, 15-25 parts of ethylene trifluorochloroethylene copolymer, 4-8 parts of nano titanium dioxide particles, 6-10 parts of isocyanate curing agent, 2-5 parts of hindered phenolic antioxidant, and 30-45 parts of N,N-dimethylformamide.

9. The method for preparing a waterproof and antioxidant nuclear medicine dry printing film according to claim 1, characterized in that, The calendering process in step S3 is as follows: the object is placed in a temperature-controlled calender and calendered at a constant speed for 3-5 minutes under the conditions of 80℃-90℃ and 0.3MPa-0.5MPa. After processing, it is allowed to cool naturally to room temperature.

10. A waterproof and antioxidant nuclear medicine dry printing film prepared by the method of any one of claims 1-9.

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