Ultra-high vacuum manufacturing method for radiation shielding film, using antimony-tungsten alloy

Abstract

The present disclosure relates to an ultra-high vacuum manufacturing method for a radiation shielding film and, more specifically, an ultra-high vacuum manufacturing method for a radiation shielding film, using an antimony-tungsten alloy, can provide a radiation shielding film having an excellent shielding rate and minimized void generation while using antimony, which has excellent processability and economic feasibility.　The ultra-high vacuum manufacturing method for a radiation shielding film, according to one embodiment of the present invention, comprises the steps of: mixing a first shielding component and a tungsten powder so as to obtain a first mixture; mixing the first mixture with a polymer component so as to obtain a second mixture; using ultra-high vacuum to remove bubbles from the second mixture, thereby obtaining a third mixture; and manufacturing a shielding sheet having a thickness of 1.0 mm or less by using the third mixture.

Description

Ultra-high vacuum manufacturing method for radiation shielding using antimony-tungsten alloy

[0001] The present disclosure relates to an ultra-high vacuum manufacturing method for a radiation shielding film, and more particularly, to an ultra-high vacuum manufacturing method for a radiation shielding film using an antimony-tungsten alloy.

[0002] In the case of shielding films that shield radiation, the shielding effect is generally achieved by utilizing the scattering and absorption of incident radiation. In such radiation shielding films, the energy is attenuated through the interaction of radiation with matter, and the effect is affected by the density and structure of the radiation shielding film.

[0003] Against this backdrop, there is a demand for a thin-film shielding film with reduced thickness and lightweight conditions to minimize shielding weight, but excellent radiation shielding effect is often in conflict with the demand for reduced thickness and lightweight, such as when the density or thickness of the shielding film increases.

[0004] Recently, in order to solve the problem of increasing thickness in order to provide a shielding film with excellent shielding performance as mentioned above, a method of using tungsten or tungsten wire, an environmentally friendly material instead of lead, has been proposed. However, tungsten material is expensive, making it impossible to consider economic feasibility at all, and thus there is a major problem in practical application.

[0005] Against this backdrop, there is a need for a method for manufacturing a radiation shielding film that provides lightness and thinness by using an ultra-high vacuum process technology while applying a material that can replace tungsten.

[0006] The purpose of the present disclosure is to provide an ultra-high vacuum manufacturing method for a radiation shielding film using an antimony-tungsten alloy, and to provide a manufacturing method for a radiation shielding film having an excellent shielding rate and minimized generation of voids while using antimony having excellent processability and economic feasibility.

[0007] Another object of the present disclosure is to provide a method for manufacturing a radiation shielding film using an antimony-tungsten alloy in an ultra-high vacuum, and to provide a method for manufacturing a radiation shielding film that has excellent shielding performance compared to conventional radiation shielding films while having a relatively thin thickness and being lightweight.

[0008] The problems to be solved by the present disclosure are not limited to the problems mentioned above, and problems to be solved by the present disclosure that are not mentioned can be clearly understood by a person having ordinary knowledge in the technical field to which the present disclosure belongs (“ordinary skilled person”) from the description below.

[0009] In order to solve the technical problem of the present disclosure as described above, the present disclosure provides an ultra-high vacuum manufacturing method of a radiation shielding film:

[0010] A step of obtaining a first mixture by mixing a first shielding component and tungsten powder;

[0011] A step of obtaining a second mixture by mixing a polymer component into the first mixture;

[0012] A step of obtaining a third mixture by removing air bubbles from the second mixture using an ultra-high vacuum; and

[0013] A method for manufacturing a radiation shielding film in ultra-high vacuum can be provided, comprising a step of manufacturing a shielding sheet having a thickness of 1.0 mm or less using the third mixture.

[0014] For example, the first shielding component may be one or more components selected from the group consisting of antimony, barium sulfate, and bismuth oxide.

[0015] For example, the average particle size of the first shielding component and the tungsten powder may be 0.1 to 10 um in diameter.

[0016] For example, the first shielding component and the tungsten powder may be mixed in a ratio of 20:80 to 40:60 based on their respective weights.

[0017] For example, the polymer component may be a polyolefin.

[0018] For example, the polymer component may be at least one selected from the group consisting of polyethylene, polypropylene, polybutene, and polyethylene terephthalate.

[0019] For example, the polymer component may be polypropylene having a weight average molecular weight of 30,000 to 200,000 g / mol.

[0020] For example, the polymer component may be polyethylene having a weight average molecular weight of 20,000 to 1,000,000 g / mol.

[0021] For example, the polymer component may be polybutene having a weight average molecular weight of 2,000 to 5,000 g / mol.

[0022] For example, the polymer component may be polyethylene terephthalate having a weight average molecular weight of 20,000 to 30,000 g / mol.

[0023] For example, the polymer component may be mixed in an amount of 50 to 90 parts by weight based on 100 parts by weight of the entire second mixture.

[0024] For example, the polymer component further comprises ultra-high molecular weight polyethylene, and the weight average molecular weight of the ultra-high molecular weight polyethylene is 2.0x10 6 3.0x10 6 It could be.

[0025] For example, the ultra-high molecular weight polyethylene may be included in an amount of 3 to 15 parts by weight based on 100 parts by weight of the total polymer component.

[0026] For example, the ultra-high vacuum may be a vacuum condition of 0.1 to 0.5 Pa.

[0027] For example, the temperature conditions when the above ultra-high vacuum is applied may be 80 to 100 degrees Celsius.

[0028] For example, the step of manufacturing the shielding sheet may be performed under conditions of maintaining the pressure of 20 MPa or more and the temperature of 150 to 200 degrees Celsius for 2 to 3 hours.

[0029] The ultra-high vacuum manufacturing method of a radiation shielding film using an antimony-tungsten alloy according to the present disclosure can provide a method of manufacturing a radiation shielding film having an excellent shielding rate and minimized generation of voids while using antimony having excellent processability and economic feasibility.

[0030] In addition, the ultra-high vacuum manufacturing method of a radiation shielding film using an antimony-tungsten alloy according to the present disclosure can provide a method of manufacturing a radiation shielding film that has excellent shielding performance compared to conventional radiation shielding films, while having a relatively thin thickness and being lightweight.

[0031] The excellent and / or useful effects according to the present disclosure are not limited to the effects of the present disclosure described above, and it should be understood that those skilled in the art will also be able to clearly recognize excellent and / or useful effects of the present disclosure that are not explicitly disclosed in the present disclosure based on the disclosure of the present specification, and that these are intentionally disclosed by the present specification and are clearly included in the scope of the present disclosure.

[0032] FIG. 1 is a flowchart schematically showing each step of an ultra-high vacuum manufacturing method of a radiation shielding film according to one embodiment of the present disclosure.

[0033] FIG. 2 and FIG. 3 are views showing a mixture of metal particles and polymer materials obtained during an ultra-high vacuum manufacturing process of a radiation shielding film according to one embodiment of the present disclosure.

[0034] The following description of the present invention with reference to the drawings is not limited to specific embodiments, and various modifications and embodiments may be made. Furthermore, the following description should be understood to encompass all modifications, equivalents, and alternatives within the spirit and technical scope of the present invention.

[0035] In the following description, terms such as "first," "second," etc. are used to describe various components, and are not intended to limit their meanings. They are used solely to distinguish one component from another. Furthermore, the same reference numbers used throughout this specification represent the same components.

[0036] Unless otherwise stated herein, certain steps or processes may be performed at room temperature. Room temperature may range from 15 to 30 degrees Celsius, and preferably from 20 to 25 degrees Celsius.

[0037] As used herein, singular expressions include plural expressions unless the context clearly dictates otherwise. In addition, terms such as "comprise," "include," or "have" used herein should be interpreted to indicate the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, and should be understood to not preclude the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0038] According to one embodiment of the present disclosure, a method for manufacturing a radiation shielding film in ultra-high vacuum can be provided.

[0039] For example, the ultra-high vacuum manufacturing method of the present disclosure for a radiation shielding film may include: a step of mixing a first shielding component and a tungsten powder to obtain a first mixture; a step of mixing a polymer component into the first mixture to obtain a second mixture; a step of removing air bubbles from the second mixture using an ultra-high vacuum to obtain a third mixture; and a step of manufacturing a shielding sheet having a thickness of 1.0 mm or less using the third mixture.

[0040] The ultra-high vacuum manufacturing method of the radiation shielding film of the present disclosure as described above mixes a first shielding component selected from the group containing antimony and tungsten powder, and uses a mixture of the mixture and a polymer component to form a thin radiation shielding film, and can apply high pressure during the process by reducing bubbles without using a thermal deposition method, and can form a radiation shielding film having excellent density and compactness.

[0041] For example, the first shielding component may be one or more components selected from the group consisting of antimony, barium sulfate, and bismuth oxide. Preferably, the first shielding component may be antimony, and in this case, the density of the formed mixture may be increased due to higher miscibility with the polymer component compared to when barium sulfate and bismuth oxide are used.

[0042] For example, the average particle size of the first shielding component and the tungsten powder may be 0.1 to 10 μm in diameter. When the average particle size of the first shielding component and the tungsten powder satisfies the above numerical range, the miscibility of the first shielding component and the tungsten powder with the polymer component is maximized, thereby achieving excellent bubble removal characteristics in an ultra-high vacuum environment. Preferably, the average particle size of the first shielding component and the tungsten powder may be less than 10 μm, and more preferably, less than 5 μm.

[0043] For example, the first shielding component and the tungsten powder may be mixed in a ratio of 20:80 to 40:60 based on their respective weights.

[0044] For example, the polymer component may be a polyolefin, and examples of the polyolefin include a crystalline homopolymer or copolymer polymerized with polyethylene (PE), polypropylene (PP), polyester (PET), polybutene, polyethylene terephthalate (PET), polystyrene (PS), ethylene, propylene, 1-butene, 4-methylpentene, 1-hexene, etc., and vinyl chloride resin, vinyl acetate resin, polystyrene, fluororesin, polyamide resin, polyacetal resin, polycarbonate, thermoplastic polyimide, thermoplastic polyurethane, polyphenylene sulfide, polyvinyl alcohol, etc.

[0045] For example, the polymer component may be used with an additional additive. The additive may be a curing agent, and the curing agent may be benzoyl peroxide, amines, isocyanates, or the like.

[0046] For example, the additional additives may include stabilizers such as zinc stearate as a zinc-based stabilizer, calcium stearate as a calcium-based stabilizer, and barium stearate as a barium-based stabilizer.

[0047] For example, the above additional additives may include accelerators such as phenol, nonylphenol, tertiary amines, mercaptans, and dibutyltin diacetate, stannous oxide, 60-copper complex compound, and Ni-A1 complex.

[0048] For example, the additional additives may include emulsifiers such as copolymers of polyoxyethylene and polyoxypropylene, copolymers of polyoxyethylene and polyoctylphenyl ether (trade names Adeka NE-10, SE-10N, etc.).

[0049] Plasticizers can be added for flexibility after curing, and phthalate-based plasticizers and eco-friendly plasticizers (plasticizers that do not contain ortho-phthalate) can be used.

[0050] For example, the polymer component may be at least one selected from the group consisting of polyethylene, polypropylene, polybutene, and polyethylene terephthalate.

[0051] For example, the polymer component may be polypropylene having a weight average molecular weight of 30,000 to 200,000 g / mol.

[0052] For example, the polymer component may be polyethylene having a weight average molecular weight of 20,000 to 1,000,000 g / mol.

[0053] For example, the polymer component may be polybutene having a weight average molecular weight of 2,000 to 5,000 g / mol.

[0054] For example, the polymer component may be polyethylene terephthalate having a weight average molecular weight of 20,000 to 30,000 g / mol.

[0055] For example, the polymer component may be mixed in an amount of 50 to 90 parts by weight based on 100 parts by weight of the entire second mixture. If the content of the polymer component exceeds the above numerical range, the radiation shielding effect is minimal, and if it is below the above numerical range, uniform pores are not formed in the polyolefin, so it is preferable to satisfy the above numerical range.

[0056] For example, the polymer component further comprises ultra-high molecular weight polyethylene, and the weight average molecular weight of the ultra-high molecular weight polyethylene is 2.0x10 6 3.0x10 6 It could be.

[0057] For example, the ultra-high molecular weight polyethylene may be included in an amount of 3 to 15 parts by weight based on 100 parts by weight of the total polymer component. When the content of the ultra-high molecular weight polyethylene satisfies the above numerical range, ultra-high molecular weight polyethylene having excellent rigidity, wear resistance, environmental stress uniformity, self-lubrication, chemical resistance, and electrical properties can be provided. When the content exceeds the above numerical range, it is difficult to obtain a uniform structure of the resin, and when it is below the above numerical range, the radiation shielding effect is minimal, so it is preferable to satisfy the above numerical range.

[0058] For example, the polymer component may further include a mixture of graphene oxide powder and nanocellulose, wherein the graphene oxide powder and nanocellulose are included in a ratio of 80:20 to 70:30 based on their respective weights.

[0059] For example, the graphene oxide powder may have an average diameter of 1 to 30 um, preferably 2 to 25 um.

[0060] For example, the nanocellulose may have an average diameter of 20 to 200 nm, preferably 50 to 120 nm, and an average length of 1 to 80 μm, preferably 5 to 30 μm.

[0061] For example, the mixture of the above graphene oxide powder and nanocellulose may be included in an amount of 5 to 20 parts by weight based on 100 parts by weight of the polymer component.

[0062] For example, the ultra-high vacuum may be a vacuum condition of 0.1 to 0.5 Pa.

[0063] For example, the temperature conditions when the above ultra-high vacuum is applied may be 80 to 100 degrees Celsius.

[0064] For example, the step of manufacturing the shielding sheet may be performed under conditions of maintaining the pressure of 20 MPa or more and the temperature of 150 to 200 degrees Celsius for 2 to 3 hours.

[0065] Hereinafter, preferred embodiments of the present invention will be described. However, the following examples are intended only to illustrate the present invention and are not intended to limit the scope of the present invention to the following examples.

[0066] Example 1: Manufacturing of radiation shielding sheet

[0067] Antimony and tungsten powders were mixed in a ratio of 30:70 based on their respective weights and maintained on an ultrasonic vibrator to prepare a first mixture. High-density polyethylene was selected as the polymer component, and a product having a weight-average molecular weight of 4 million or more and a density of 0.91 g / cm³ was used. This first mixture and the polymer component were mixed in a ratio of 20:80 based on their respective weights to prepare a second mixture. This was placed in a vacuum chamber and maintained in an ultra-high vacuum environment of 0.1 to 0.5 Pa for about 2 to 3 minutes to remove air bubbles, and heat was applied at 150 to 200 degrees Celsius for 2 to 3 hours to improve the degree of dispersion. Thereafter, the mixture subjected to thermal vacuum deposition was applied and maintained under conditions of a pressure of 20 MPa or more and a temperature of 175 degrees Celsius for 150 minutes to produce a shielding sheet with a thickness of 0.25 mm, and its performance was evaluated.

[0068] Example 2: Manufacturing of a shielding sheet using only tungsten powder

[0069] Example 2 shielding sheets were manufactured in the same manner as described in Example 1, except that tungsten powder was used in the same weight instead of the first mixture.

[0070] Example 3: When using a first mixture of a different composition

[0071] A shielding sheet of Example 3 was prepared in the same manner as described in Example 1, except that a mixture of barium sulfate and bismuth oxide in a 50:50 ratio based on their respective weights was used instead of the first mixture.

[0072] Example 4: When ultra-high molecular weight polyethylene is additionally included

[0073] The weight average molecular weight (Mw) is 2.5x10 6 Example 4 shielding sheets were prepared in the same manner as described in Example 1, except that a second mixture was prepared by adding 3 to 15 parts by weight of ultra-high molecular weight polyethylene together with the polymer component.

[0074] Example 5: Including additional mixtures

[0075] A shielding sheet of Example 5 was prepared in the same manner as described in Example 1, except that a second mixture was prepared by adding a mixture of graphene oxide powder having an average diameter of 2 to 25 μm and nanocellulose having an average diameter of 50 to 120 nm and an average length of 5 to 30 μm in a ratio of 75:25 based on the respective weights, together with the polymer component, in an amount of 10 parts by weight based on 100 parts by weight of the polymer component.

[0076] Experimental Example 1: Performance Evaluation of Radiation Shielding Sheets

[0077] To evaluate the radiation shielding performance of the radiation shielding films manufactured in Examples 1 to 5 above, a comparative experiment was conducted using lead plates of the same thickness (0.25 mm). The results are shown in Table 1 below.

[0078] X-ray Energy (kvp)Tube voltageShielding rate(%)Room 1Room 2Room 3Room 4Room 5Lead plate409494929597986092919193959680908587919495100908486919294120878082889092

[0079] Referring to Table 1 above, it was confirmed that the shielding film of Example 1 according to the present disclosure exhibited significantly improved X-ray blocking performance compared to a shielding sheet using only tungsten powder and a shielding sheet using conventional barium sulfate and bismuth oxide, and that it had an excellent radiation shielding performance at the same level as compared to a lead plate of the same thickness. In addition, referring to Table 1 above, it was confirmed that the shielding films of Examples 4 and 5 according to the present disclosure exhibited improved radiation blocking performance compared to the shielding films of Examples 1 and 2, and in particular, the shielding film of Example 5 was confirmed to have an excellent radiation shielding performance compared to a lead plate of the same thickness.

[0080] Experimental Example 2: Density Evaluation of Radiation Shielding Sheets

[0081] As a first mixture, barium sulfate powder and tungsten powder were used in a ratio of 30:70 based on their respective weights, bismuth oxide powder and tungsten powder were used in a ratio of 30:70 based on their respective weights, and antimony powder and tungsten powder were used in a ratio of 30:70 based on their respective weights. Shielding sheets having a thickness of 0.3 mm were manufactured in the manner described in Example 1, and their densities were evaluated. The results are shown in Table 2 below.

[0082] Density barium sulfate + bismuth tungsten oxide + tungsten antimony + tungsten g / cm 3 1.651.782.05

[0083] Referring to Table 2 above, it was confirmed that the shielding sheet using a mixture of antimony powder and tungsten powder as the first mixture had the highest density, and thus, when antimony and tungsten are used in the shielding sheet according to the present disclosure, excellent mixing properties of the polymer component and the metal component are developed in an ultra-high vacuum environment, forming a shielding sheet with a high density, and as a result, forming a shielding sheet with excellent radiation shielding performance. As described above, exemplary embodiments have been disclosed in the drawings and the specification. Although the embodiments have been described using specific terminology in the specification, this has only been used for the purpose of explaining the technical idea of ​​the present disclosure and has not been used to limit the meaning or the scope of the present disclosure set forth in the claims. Therefore, those skilled in the art will understand that various modifications and equivalent other embodiments are possible from the present disclosure. Therefore, the true technical protection scope of the present disclosure should be defined by the technical idea of ​​the appended claims.

Claims

1. A method for manufacturing an ultra-high vacuum radiation shielding film: A step of obtaining a first mixture by mixing a first shielding component and tungsten powder; A step of obtaining a second mixture by mixing a polymer component into the first mixture; A step of obtaining a third mixture by removing air bubbles from the second mixture using an ultra-high vacuum; and An ultra-high vacuum manufacturing method for a radiation shielding film, comprising a step of manufacturing a shielding sheet having a thickness of 1.0 mm or less using the third mixture.

2. A method for manufacturing an ultra-high vacuum radiation shielding film in the first paragraph, wherein the first shielding component is at least one component selected from the group consisting of antimony, barium sulfate, and bismuth oxide.

3. A method for manufacturing an ultra-high vacuum radiation shielding film in the first paragraph, wherein the average particle size of the first shielding component and the tungsten powder is 0.1 to 10 um in diameter.

4. A method for manufacturing an ultra-high vacuum radiation shielding film, wherein the first shielding component and the tungsten powder are mixed in a ratio of 20:80 to 40:60 based on their respective weights.

5. A method for manufacturing an ultra-high vacuum radiation shielding film in the first paragraph, wherein the polymer component is at least one selected from the group consisting of polyethylene, polypropylene, polybutene, and polyethylene terephthalate.

6. A method for manufacturing an ultra-high vacuum radiation shielding film, wherein in the first paragraph, the polymer component is mixed in an amount of 50 to 90 parts by weight based on 100 parts by weight of the entire second mixture.

7. In the first paragraph, the polymer component further comprises ultra-high molecular weight polyethylene, and the weight average molecular weight of the ultra-high molecular weight polyethylene is 2.0x10 6 3.0x10 6 A method for manufacturing an ultra-high vacuum radiation shielding film.

8. A method for manufacturing an ultra-high vacuum radiation shielding film in the first paragraph, wherein the ultra-high molecular weight polyethylene is included in an amount of 3 to 15 parts by weight based on 100 parts by weight of the total polymer component.

9. A method for manufacturing an ultra-high vacuum radiation shielding film, wherein the ultra-high vacuum in the first paragraph is a vacuum condition of 0.1 to 0.5 Pa.

10. A method for manufacturing an ultra-high vacuum radiation shielding film, wherein the temperature condition when the ultra-high vacuum is applied in the first paragraph is 80 to 100 degrees Celsius.

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