KR20240005263A - Radiation shielding film comprising waste plastic and manufacturing method of the same - Google Patents

Abstract

This specification relates to a radiation shielding film and a manufacturing method thereof. According to the present disclosure, it includes an eco-friendly radiation shielding material that replaces lead and uses waste plastic as a polymer face mixed with the shielding material, so that it can be manufactured at low cost and is environmentally friendly. A radiation shielding film can be provided. The present disclosure improves the mixing between radiation shielding material and waste plastic and exhibits excellent radiation shielding performance even when manufactured at a thin thickness, so it is useful in various industrial fields and various products that require radiation shielding films, such as the medical field or construction field. It can be used effectively.

Description

Radiation shielding film comprising waste plastic and manufacturing method of the same}

This specification relates to radiation shielding films and methods for manufacturing the same.

Lead is mainly used to manufacture radiation shields in medical institutions. Lead has excellent X-ray shielding performance, processability, and economic efficiency, so it is widely used in various forms in medical institutions. However, as lead use increases, there is a risk of lead poisoning because medical staff and patients are exposed to more lead, and lead disposal is also related to environmental issues. In addition, as the use of disposable containers and packaging materials has increased due to the COVID-19 pandemic, the generation of waste plastic has increased significantly, requiring research into ways to utilize waste plastic.

Medical institutions generally require shielding suits for radiation shielding, and thin shielding fabrics are required for lightness and flexibility. Radiation shielding fabrics for existing radiation shielding clothing have been manufactured through the calendar process or coating process by mixing polymer resin and shielding material for flexibility. However, when radiation shielding material is included in a high content to maintain reproducibility of shielding performance, The polymer resin and radiation shielding material particles are not evenly mixed with the polymer resin and are aggregated somewhere, causing pinholes to occur in places where they are not aggregated. Therefore, there was a problem that the radiation shielding performance was not constant throughout the film and varied depending on the part. . In addition, if a small amount of radiation shielding material is included to prevent agglomeration, there is a problem that the radiation shielding performance is low, making it unsuitable for use in medical institutions. Therefore, a new technology is needed that can prevent agglomeration and provide excellent radiation shielding performance by improving miscibility with polymer resin while containing a high content of radiation shielding material.

Republic of Korea Patent Publication No. 10-1261340

From one perspective, the problem that the present disclosure aims to solve is to provide a radiation shielding film that includes an environmentally friendly radiation shielding material and has excellent radiation shielding performance and flexibility.

From one perspective, the problem that the present disclosure aims to solve is to provide a method for manufacturing the radiation shielding film.

One embodiment of the present disclosure is a radiation shielding film comprising a radiation shielding material and a polymer base containing waste plastic, the thickness of the film is 0.3 to 3 mm, and the film contains the radiation shielding material at a weight of 40% based on the total weight of the film. to 80% by weight, providing a radiation shielding film.

Another embodiment of the present disclosure provides a radiation-shielding fabric including the radiation-shielding film.

Another embodiment of the present disclosure is a method of manufacturing the radiation shielding film,

Injecting a portion of the radiation shielding material into a solution in which waste plastic is dissolved, mixing and melting, and repeating the step four or more times; and

Forming the final mixture in the above step into a film form;

Includes,

The content of radiation shielding material added per time in the mixing and melting step is 5 to 10% by weight based on the total weight of the final mixture,

A method for manufacturing a radiation shielding film is provided.

Embodiments of the present disclosure include an eco-friendly radiation shielding material that replaces lead and use waste plastic as a polymer face mixed with the shielding material, thereby providing an environmentally friendly radiation shielding film that can be manufactured at low cost. In addition, one embodiment of the present disclosure improves the mixing between radiation shielding material and waste plastic by introducing a multi-carrier process while using the low-cost and eco-friendly material as described above, and thus includes a high content of radiation shielding material and allows the radiation shielding material to be used as waste plastic. It is uniformly dispersed at high density without agglomeration or pinholes within the plastic polymer resin, showing excellent radiation shielding performance even when manufactured at a thin thickness. Therefore, the present disclosure can be usefully used in various industrial fields and various products that require radiation shielding films, such as the medical field or the construction field.

Figure 1 shows a road photographed step by step at the manufacturing site of waste plastic pellets according to an embodiment of the present disclosure, from the left, washed and dried waste plastic - pulverized waste plastic - waste plastic manufactured in the form of pellets.
Figure 2 is a road taken step by step at the film forming site according to an embodiment of the present disclosure, clockwise showing (a) thermoplastic sheet molding machine, (b) winding step, (c) pressing step, and (d) filler input step. represents.
Figure 3 is an image taken of the radiation sequence film of Comparative Example 1 (a) manufactured according to the prior art and Example 1 (b) manufactured according to an embodiment of the present disclosure.
Figure 4 is a scanning electron microscope (SEM) image to confirm the internal cross-section of a radiation shielding film manufactured by a conventional process as a comparative example. The photo on the right is a 2-fold enlargement of the photo on the left, and the red circle in the photo on the right is a pinhole. It indicates the area where it occurred.
Figure 5 is a scanning electron microscope (SEM) image for confirming the internal cross-section of a radiation film manufactured according to an embodiment of the present disclosure. The photo on the right is a 2-fold enlargement of the photo on the left, and the red circle in the photo on the right is This indicates the area where the pinhole occurred.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings.

The embodiments of the present invention disclosed in the text are illustrative only for illustrative purposes, and the embodiments of the present invention may be implemented in various forms and should not be construed as limited to the embodiments described in the text. . The present invention can make various changes and take various forms, and the embodiments are not intended to limit the present invention to the specific disclosed form, but all changes, equivalents, or substitutes included in the spirit and technical scope of the present invention. It should be understood as including.

Singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, terms such as “comprise” or “have” are intended to designate the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, and one or more other features The presence or addition of elements, numbers, steps, operations, components, parts or combinations thereof is not excluded.

One embodiment of the present disclosure is a radiation shielding film including a radiation shielding material and a polymer base containing waste plastic, the thickness of the film is 0.3 to 3 mm, and the film includes the radiation shielding material in the total weight of the film. It is possible to provide a radiation shielding film containing 40 to 80% by weight.

Specifically, the waste plastic may be thermoplastic plastic. Unlike thermosetting plastics, thermoplastic plastics can be molded by heat and thus can be used as the polymer base in the present disclosure. By using waste plastic as a polymer base, the present disclosure can contribute to improving the environment by preventing pollution caused by plastic waste and recycling it, and waste plastic has a low cost relative to its volume, so it can also provide economic benefits to producers. As an example, the waste plastic is not limited as long as it is thermoplastic, for example, polyethylene terephthalate (PET), polyethylene (PE), polyvinyl chloride (PVC), polypropylene (PP), polystyrene (PS), polyamide. (PA), polycarbonate (PC), and ethylene-propylene copolymer.

As an example, the content of the polymer base may be 20 to 60% by weight based on the total weight of the film. Specifically, the content of the polymer base is 20% by weight or more, 25% by weight or more, 30% by weight or more, 35% by weight or more, 40% by weight or more, 41% by weight or more, 42% by weight or more, 43% by weight or more. It may be at least 44% by weight, at least 45% by weight, at least 46% by weight, at least 47% by weight, at least 48% by weight, at least 49% by weight, at least 50% by weight, or at least 55% by weight, and not more than 60% by weight. , 55% by weight or less, 54% by weight or less, 53% by weight or less, 52% by weight or less, 51% by weight or less, 50% by weight or less, 49% by weight or less, 48% by weight or less, 47% by weight or less, 46% by weight or less. , 45% by weight or less, 44% by weight or less, 43% by weight or less, 42% by weight or less, 41% by weight or less, 40% by weight or less, 35% by weight or less, 30% by weight or less, or 25% by weight or less. If the content of the polymer base is less than 20% by weight, the tensile strength or flexibility of the film may decrease and the quality of the film may deteriorate, and if it exceeds 60% by weight, the content of the radiation shielding material is relatively reduced and the radiation shielding performance deteriorates. It can be.

As an example, the film may be a lead-free film. The present disclosure does not contain lead, so it is safe for the human body and harmless to the environment, and can be usefully used in the medical field and other fields that require radiation shielding performance. For example, one embodiment of the present disclosure may include one or more types selected from barium sulfate, tungsten, boron, bismuth oxide, antimony, copper, and tin as a radiation shielding material. More specifically, the film may include barium sulfate (BaSO ₂ ) as a radiation shielding material. Barium sulfate is a white powder or amorphous crystal, has a specific gravity of 4.25 to 4.5, and is a substance that decomposes at 1,600°C. The barium sulfate has the advantage of being much cheaper than tungsten, another eco-friendly radiation shielding material, but has a low density, so when manufactured to the same thickness as a film containing tungsten, barium sulfate cannot be included in the same content as tungsten compared to a tungsten shielding body. There are limits. However, according to an embodiment of the present disclosure, the contact area between barium sulfate particles and the polymer base can be increased as much as possible, thereby improving the miscibility of barium sulfate and the polymer base, so barium sulfate is included at the same high content as tungsten. This can provide excellent radiation shielding performance.

In view of the above, as an example, the film may include 40 to 80% by weight of the radiation shielding material based on the total weight of the film. Specifically, the radiation shielding material is 40% by weight or more, 42% by weight or more, 44% by weight or more, 46% by weight or more, 48% by weight or more, 50% by weight or more, 52% by weight or more, 54% by weight or more based on the total weight of the radiation shielding film. It may be included in more than % by weight, more than 56% by weight, more than 58% by weight, more than 60% by weight, more than 65% by weight, more than 70% by weight or more than 75% by weight, and less than 80% by weight, less than 75% by weight, less than 70% by weight. % or less, 65% by weight or less, 60% by weight or less, 58% by weight or less, 56% by weight or less, 54% by weight or less, 52% by weight or less, 50% by weight or less, 48% by weight or less, 46% by weight or less, 44% by weight It may be included in % or less or 42% by weight or less. If the radiation shielding material is included in less than 40% by weight, the radiation shielding ability may be lowered, and if it is more than 80% by weight, the polymer base content may be relatively reduced and the durability of the film may be reduced.

As an example, the average particle size of the radiation shielding material is not limited, but may be, for example, 600 nm to 10 μm. At this time, the particle size refers to the largest diameter within the particle. The average particle size refers to the average particle size of at least 90% of the radiation shielding material included in the radiation shielding film. Specifically, the average particle size of the radiation shielding material is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, or 97% of the radiation shielding film. , may mean the average value of the largest diameter within the particles of 98% or more or 99% or more of the powders. If the particle size is outside the above range, radiation shielding performance may be lowered or the thickness of the film may increase excessively, resulting in poor processability.

As an example, the radiation shielding material may be uniformly dispersed in the film. Specifically, the film may have reduced partial aggregation of the polymer base and the resulting pinholes.

As an example, the film may further include one or more of a modifier, plasticizer, antioxidant, heat stabilizer, flame retardant, and lubricant as an additive in order to improve physical properties and make manufacturing easier. At this time, the content of the additive may be appropriately adjusted by the user within a range that does not deteriorate the performance of the present disclosure.

As an example, the modifier is a material that improves the processability of the film and facilitates adhesion to fabric or a substrate, and is not limited as long as it is commonly used in the technical field of the present disclosure, for example, polymethyl methacrylate ( PMMA) or polytetrafluoroethylene (PTFE). As an example, the plasticizer is not limited as long as it is commonly used in the technical field of the present disclosure, but includes, for example, phthalic acid esters, aliphatic dibasic acid esters, phosphoric acid esters, trimellitic acid esters, glycol esters, It may include one or more selected from epoxidized esters, citric acid esters, tetra-n-oxyl citrate, polypropylene adipate, and polyester series. As an example, the antioxidant is a substance added to prevent the formation of radicals during the process of processing the resin, and is not limited as long as it is commonly used in the technical field of the present disclosure, for example, a phenol-based antioxidant. , amine-based antioxidants, sulfone-based antioxidants, or phosphate-based antioxidants. As an example, the heat stabilizer is used to slow the ignition of a polymer resin that is easily combustible and prevent the expansion of combustion to facilitate processing at high temperatures, and is limited to those commonly used in the technical field of the present disclosure. However, it may include, for example, a Ba-Zn-based heat stabilizer. In one embodiment, the flame retardant is added to prevent combustion of the polymer resin, and is not limited as long as it is commonly used in the technical field of the present disclosure, for example, meramine cyanureto compound, hydrotalcite, zinc tartrate , zinc hydroxystannate, zinc borate, zinc oxide, tin oxide, titanium oxide, magnesium oxide, molybdenum oxide, molybdenum sulfide, carbon, clay, silica, alumina, calcium carbonate, magnesium carbonate, talc, zeolite, antimony trioxide, silicon. It may include compounds or glass fibers. As an example, the lubricant is not limited as long as it is commonly used in the technical field of the present disclosure, but for example, aliphatic hydrocarbon lubricants such as low molecular wax, polyethylene wax, paraffin wax and liquid paraffin, and higher aliphatic lubricants such as stearyl alcohol. Alcohol-based lubricants, aliphatic amide-based lubricants such as stearic acid amide, parmitic acid amide and methylene vis tear amide, fatty acid ester-based lubricants such as glycerin stearate, ethyl diamino stearate and butyl stearetto, metallic soap, Alternatively, it may include an acrylic polymer.

As an example, the thickness of the film may be 0.3 to 3 mm. Since the present disclosure can be manufactured with a thin thickness as described above, as an example, a multilayer structure can be formed by stacking a plurality of films, and in this case, radiation shielding performance can be further improved. Specifically, the thickness of the film is 0.3 mm or more, 0.5 mm or more, 1 mm or more, 1.2 mm or more, 1.4 mm or more, 1.6 mm or more, 1.8 mm or more, 2 mm or more, 2.2 mm or more, 2.4 mm or more, 2.6 mm or more. or greater than or equal to 2.8 mm, and may be 3 mm or less, 2.8 mm or less, 2.7 mm or less, 2.5 mm or less, 2.3 mm or less, 2 mm or less, 1.8 mm or less, 1.5 mm or less, 1.2 mm or less, 1 mm or less, or 0.5 mm. It may be below. If the film thickness is less than 0.3 mm, radiation shielding performance may be reduced or the film may crack due to low tensile strength. Even when the film thickness exceeds 3 mm, flexibility may decrease and cracks may occur in the film, and the increase in film thickness and weight may cause inconvenience when used in clothing such as radiation shielding suits, limiting the range of use.

As an example, the density of the film may be 9 to 18 g/cm3.

In addition, an embodiment of the present disclosure is a method of manufacturing the radiation shielding film, including the steps of adding a portion of the radiation shielding material to a solution in which waste plastic is dissolved, mixing, and melting, repeating the step four or more times; and forming the final mixture in the above step into a film form. At this time, the content of the radiation shielding material added per time in the mixing and melting steps may be 5 to 10% by weight based on the total weight of the final mixture. More specifically, the content of radiation shielding material added per time in the mixing and melting step is 5% by weight or more, 6% by weight or more, 7% by weight or more, 8% by weight or more, 9% by weight or more, or 9.5% by weight or more. It may be more than 10% by weight, 9% by weight or less, 8% by weight or less, 7% by weight or less, 6% by weight or less, or 5.5% by weight or less. If the content of the radiation shielding material added per time exceeds 10% by weight based on the total weight of the final mixture, the radiation shielding material may be unevenly dispersed within the film, and if it is less than 5% by weight, manufacturing efficiency may be reduced. In view of the above, the steps of adding a portion of the radiation shielding material to the waste plastic solution, mixing and melting the waste plastic solution according to an embodiment are 4 or more times, 5 or more times, 6 or more times, 7 or more times, 8 or more times, 9 or more times, 10 or more times. It may be repeated 1 or more times, 11 or more times, 12 or more times, 13 or more times, 14 or more times, 15 or more times, 16 or more times, 17 or more times, 18 or more times, 19 or more times, or 20 or more times. There is no limit to the number of times.

In the past, when manufacturing a radiation shielding film, polymer resin and radiation shielding material were typically manufactured by mixing all amounts at the same time without any time interval. However, in this case, the viscosity of the polymer resin was lowered and the interfacial activity of the shielding material particles was lowered, so the polymer resin There was a problem that agglomeration occurred and pinholes were created inside the film. In this case, since the internal density of the radiation shielding material in the film is non-uniform and does not provide consistent shielding performance, there is a limitation in that it must be manufactured to a certain thickness or more, or the content of the radiation shielding material must be reduced when manufactured at a thin thickness. However, one embodiment of the present disclosure is a multi-carrier process in which part of the radiation shielding material is added to a container containing a waste plastic solution, mixed and melted, and then another part is added to the container, and the same mixing and melting steps are repeated. By performing this, the contact area between the radiation shielding material particles and the polymer resin can be maximized to improve mixing properties. That is, according to one embodiment of the present disclosure, the radiation shielding material particles can be uniformly dispersed using inter-particle space pressure by adding a constant amount of radiation shielding material particles while maintaining the viscosity of the polymer resin. This allows the radiation shielding material particles to be uniformly distributed. It can act as a physical barrier for polymer resins and prevent polymer aggregation.

As an example, the temperature of heat applied in the mixing and melting step is not limited as long as it is a temperature that can mix and melt the polymer base and the radiation shielding material, but may be, for example, 220 to 320°C. Specifically, the temperature may be 220°C or higher, 230°C or higher, 240°C or higher, 250°C or higher, 260°C or higher, 270°C or higher, 280°C or higher, 290°C or higher, 300°C or higher, or 310°C or higher, and 320°C. Hereinafter, it may be 310°C or less, 300°C or less, 290°C or less, 280°C or less, 270°C or less, 260°C or less, 250°C or less, 240°C or less, 230°C or less, or 225°C or less.

As an example, the total mixing time of the mixing and melting step is not limited as long as it is sufficient to mix and melt the polymer base and the radiation shielding material, but may be, for example, 6 to 18 hours. Specifically, the total mixing time is at least 6 hours, at least 7 hours, at least 8 hours, at least 9 hours, at least 10 hours, at least 11 hours, at least 12 hours, at least 13 hours, at least 14 hours, at least 15 hours, and at least 16 hours. It can be longer than or equal to 17 hours, less than 18 hours, less than 17 hours, less than 16 hours, less than 15 hours, less than 14 hours, less than 13 hours, less than 12 hours, less than 11 hours, less than 10 hours, less than 9 hours, less than 8 hours. It may be less than or less than 7 hours.

As an example, the method may further include preparing a solution in which waste plastic is dissolved before the mixing step. Here, the waste plastic may be a waste plastic pellet, and its shape or size is not limited. As an example, the step of producing the waste plastic pellets is not limited to the method as long as the waste plastic can be produced in a pellet-like form, but includes, for example, washing and drying the waste plastic; A flake step of pulverizing the dried waste plastic; And it may include manufacturing the flakes into pellet-shaped chips. Additionally, as an example, the method may further include preparing a casting solution by dissolving the waste plastic pellets in a solvent. As an example, the type of solvent is not limited as long as it can dissolve the waste plastic being used, and may include, for example, N-dimethylformamide (DMF). In one embodiment, the waste plastic may be completely dissolved in a solvent, and the step of removing internal bubbles by leaving the solution for a certain period of time may be further included. The leaving time may be, for example, 12 hours or more, 13 hours or more, 14 hours or more, or 15 hours or more.

As an example, the method may further include pulverizing the radiation shielding material into powder form before the mixing step. For example, the step of pulverizing the radiation shielding material may include repeating ultrasonic pulverizing the radiation shielding material one or more times using a pulverizer. In addition, as an example, the method may further include a drying step after pulverizing the radiation shielding material into powder form. Specifically, the drying temperature and time of the drying step may vary depending on the amount of pulverized radiation shielding material. For example, the drying temperature may be 40 to 80°C, more specifically 50 to 70°C. For example, the drying time may be 15 to 35 hours, more specifically 20 to 28 hours.

As an example, the casting solution may further include one or more of a radiation shielding film modifier, a plasticizer, an antioxidant, a heat stabilizer, a flame retardant, and a lubricant as additives, the types of which are as described above.

Additionally, as an example, the method may further include removing foreign substances, bubbles, etc. contained in the casting solution before forming it into a film form.

As an example, the step of forming the film may be performed using a thermoplastic film molding machine. However, the solution containing the polymer base and the radiation shielding material according to an embodiment of the present disclosure may be formed into a film. If there is one, it is not limited to this. For example, the film may be formed by compression molding. Specifically, the compression molding may be performed by applying heat, and more specifically, it may be performed using a thermal hydraulic press machine. At this time, the temperature of heat applied in the compression molding step may be 60 to 90°C, and the pressure applied may be 10 to 30 MPa.

As an example of the present disclosure, the x-ray shielding rate of the radiation shielding film may vary depending on the content of the radiation shielding material included in the film and the thickness of the film. For example, the radiation shielding rate may be 62 to 90% when measured in a tube voltage range of 60 to 120 kVp. Specifically, the x-ray shielding rate of the film is 70 to 80% when measured at a tube voltage range of 60 kVp, 65 to 75% when measured at a tube voltage range of 80 kVp, 63 to 73% when measured at a tube voltage range of 100 kVp, and 120 kVp. When measured in the tube voltage range, it may be 62 to 68%.

As an example, the tensile strength of the radiation shielding film may vary depending on the content of the polymer base included in the film and the thickness of the film. For example, the tensile strength may be 100 to 180 MPa based on a film with a thickness of 1 to 5 mm, but is not limited thereto. Specifically, the tensile strength may be 100 MPa or more, 110 MPa or more, 120 MPa or more, 130 MPa or more, 140 MPa or more, 150 MPa or more, 160 MPa or more, 170 MPa or more, or 180 MPa, 260 MPa or more, 250 MPa or more. It may be less than MPa, less than 240 MPa, less than 230 MPa, less than 220 MPa, less than 210 MPa, less than 200 MPa, less than 190 MPa, or less than 180 MPa. Although the film according to the present disclosure contains a high content of radiation shielding material, it has a high tensile strength and is unlikely to crack, so it is excellent in processability and usability.

One embodiment of the present disclosure can provide a radiation-shielding fabric including the radiation-shielding film described above. Alternatively, an embodiment of the present disclosure may provide a radiation shielding suit (radiation shielding clothing) or a building material for a radiation shielding facility including the radiation shielding film described above. For example, the radiation shielding film may be a radiation shielding suit, radiation shielding curtain, protective wall, wallpaper, construction interior material, etc., and may be specifically for use in the medical field, but is not limited thereto.

Hereinafter, the present invention will be described in more detail through examples. These examples are only for illustrating the present invention, and it will be obvious to those skilled in the art that the scope of the present invention should not be construed as limited by these examples.

[Example 1]

A radiation shielding film according to an embodiment of the present disclosure was manufactured in the following manner.

First, commercial PET bottles were collected as waste plastic, washed and dried. According to a method commonly used in the industry, the dried waste plastic was pulverized through a flake process, and then the flakes were used to manufacture pellet-shaped chips. The pretreatment step of the waste plastic is exemplarily shown in FIG. 1.

The waste plastic pellets prepared as above were dissolved in N-dimethylformamide solvent to prepare a caster solution, and then left to stand for a certain period of time to remove air bubbles. The pulverized and dried barium sulfate was divided into the prepared caster solution, and a portion, specifically 5% by weight of the total weight of the final mixture, was first added and mixed and melted at a temperature of 260 to 280° C. for about 2 hours. The same amount of barium sulfate powder as above was additionally added to the container, mixed and melted at the same temperature and time, and the same step was repeated four more times. Plasticizers, lubricants, antioxidants, and heat stabilizers commonly used in the art were added to the solution as additives. After removing foreign substances from the solution and degassing it, the final caster solution was placed in a thermoplastic sheet forming machine and pressed into a film form through winding, filler input, and pressing steps. Figure 2 shows a road taken at each stage of the film forming site, clockwise, showing (a) a thermoplastic sheet molding machine, (b) a winding step, (c) a pressing step, and (d) a filler input step.

The content of barium sulfate contained in the manufactured film was 50% by weight based on the total weight of the film, and the thickness of the film was 3mm.

[Comparative Example 1]

As a comparative example of the present disclosure, a radiation shielding film was manufactured according to the prior art.

First, waste plastic pellets were manufactured in the same manner as in Example 1. This was put into a solvent and dissolved to prepare a caster solution, and then left to stand for a certain period of time to remove air bubbles. The entire amount of barium sulfate was added to the prepared caster solution, and the radiation shielding material was dispersed by stirring at 3000 rpm for 10 to 15 minutes at a temperature of 260 to 280°C. Plasticizers, lubricants, antioxidants, and heat stabilizers commonly used in the art were added to the solution as additives. After removing foreign substances from the caster solution and defoaming it, it was molded into a film in the same manner as in Example 1.

The content of barium sulfate contained in the produced film was 30% by weight based on the total weight of the film, and the thickness of the film was 3mm.

[Test Example 1]

In order to confirm the distribution of barium sulfate particles in each radiation shielding film of Example 1 and Comparative Example 1 manufactured according to an embodiment of the present disclosure, the appearance of the two films was photographed and shown in FIG. 3. In FIG. 3, the left photo is Comparative Example 1(a) manufactured according to the prior art, and the right photo is an image taken of the radiation sequence film of Example 1(b) manufactured according to an embodiment of the present disclosure. Unlike Comparative Example 1(a), in Example 1, the entire film exterior appeared evenly dark, and it could be confirmed with the naked eye that the barium sulfate particles were evenly distributed.

In addition, the cross-sections of each film of Comparative Example 1 and Example 1 were photographed using a Field Emissions Scanning Electron Microscope, and are shown in Figures 4 (Comparative Example 1) and 5 (Example 1). indicated. Each right photo in FIGS. 4 and 5 is a double enlargement of the left photo, and the red circle in the right photos indicates the area where the pinhole occurred. As shown in Figures 4 and 5, it can be confirmed that the pinholes of the radiation shielding film according to Example 1 of the present disclosure are significantly reduced compared to Comparative Example 1. This means that according to the present disclosure, even when barium sulfate is included in a high content, it is uniformly dispersed at high density within the film and can exhibit uniform radiation shielding ability throughout the film.

[Test Example 2]

The following experiment was performed to confirm the radiation shielding performance and tensile strength of the radiation shielding film manufactured according to an example of the present disclosure.

Radiation shielding performance was determined by calculating the shielding ratio using Equation 1 below.

[Equation 1]

Here, S is the shielding ratio, T ₀ is the incident dose (mR), and T is the transmitted dose (mR). Specifically, T is the exposure amount measured with a shielding film between the X-rays and the detector, and T ₀ is the exposure amount measured without a shielding film between the X-rays and the detector. Under the measured dose conditions, the tube current was 200 mA and the irradiation time was 0.1 seconds. Exposure was measured 10 times using an X-ray generator (DK-525, Toshiba E7239X, Tokyo) and a calibrated ion chamber (Model PM-30, PR-18), and the average value was used.

Tensile strength was measured according to KS M ISO 37, a test method for X-ray protection aprons for pathways (KS P 6023: 2018).

Transmission Dose 60kVp 80kVp 100kVp 120kVp No shielding shielding film No shielding shielding film No shielding shielding film No shielding shielding film Comparative Example 1 Transmitted dose (mSv) 0.342 0.133 0.871 0.398 1.401 0.815 1.721 1.059 Radiation shielding rate (%) - 61.1 - 54.3 - 41.8 - 38.4 Example 1 Transmitted dose (mSv) 0.342 0.084 0.871 0.249 1.401 0.445 1.721 0.595 Radiation shielding rate (%) - 75.43 - 71.4 - 68.2 - 65.4

tensile strength Comparative Example 1 180 MPa Example 1 180 MPa

As a result, as shown in Table 1, Example 1 according to the present disclosure can contain barium sulfate in a higher content of 20% by weight or more compared to Comparative Example 1 without coagulation or pinholes in the film, and thus provides better radiation blocking than Comparative Example 1. Performance was found to be significantly excellent. In addition, as shown in Table 2, under the same thickness conditions, Example 1 according to the present disclosure exhibits the same tensile strength as Comparative Example 1 even though it contains 20% by weight less polymer base than Comparative Example 1, resulting in excellent quality without cracking. It can be confirmed that it has .

Claims (11)

radiation shielding material; and
polymer base containing waste plastic;
It is a radiation shielding film containing,
The thickness of the film is 0.3 to 3 mm,
A radiation shielding film, wherein the film contains 40 to 80% by weight of the radiation shielding material based on the total weight of the film. The method of claim 1, wherein the waste plastic is polyethylene terephthalate (PET), polyethylene (PE), polyvinyl chloride (PVC), polypropylene (PP), polystyrene (PS), polyamide (PA), and polycarbonate (PC). ) and an ethylene-propylene copolymer. The radiation shielding film of claim 1, wherein the radiation shielding material is one or more selected from barium sulfate, tungsten, boron, bismuth oxide, antimony, copper, and tin. The radiation shielding film of claim 1, wherein the radiation shielding material is uniformly dispersed in the film. The radiation shielding film of claim 1, wherein the x-ray shielding rate of the radiation shielding film is 62 to 90% when measured in a tube voltage range of 60 to 120 kVp. A radiation-shielding fabric comprising the radiation-shielding film of any one of claims 1 to 5. A method for manufacturing the radiation shielding film of any one of claims 1 to 5,
Injecting a portion of the radiation shielding material into a solution in which waste plastic is dissolved, mixing and melting, and repeating the step four or more times; and
Forming the final mixture in the above step into a film form;
Includes,
The content of radiation shielding material added per time in the mixing and melting step is 5 to 10% by weight based on the total weight of the final mixture,
Method for manufacturing radiation shielding film. The method of claim 7, wherein the temperature of heat applied in the mixing and melting steps is 220 to 320°C. The method of claim 7, wherein the total mixing time of the mixing and melting steps is 6 to 18 hours. The method of claim 7, wherein the method further includes a step of preparing a solution in which waste plastic is dissolved before the mixing step, and the dissolved waste plastic is a waste plastic pellet. The method of claim 10, wherein the manufacturing step of the waste plastic pellets includes:
washing and drying waste plastic;
A flake step of pulverizing the dried waste plastic; and
Manufacturing the flakes into pellet form;
Method for producing a radiation shielding film, including.