WO2021096014A1

WO2021096014A1 - Hybrid lead-free radiation shielding material, and radiation suit using same

Info

Publication number: WO2021096014A1
Application number: PCT/KR2020/007284
Authority: WO
Inventors: 신승호; 신정훈
Original assignee: (주)동원엔텍
Priority date: 2019-11-11
Filing date: 2020-06-04
Publication date: 2021-05-20
Also published as: KR102318127B1; KR20210056756A

Abstract

Disclosed are: a hybrid lead-free radiation shielding material for absorbing scattered X-rays and attenuating high-dose gamma ray; and a radiation suit. The radiation shielding material comprises: an outer layer made of a scattered radiation-absorbing composition and polyurethane; and an inner layer layered on one surface of the outer layer and made of a gamma ray-shielding composition and polychloroprene, and can block both X-rays and gamma rays.

Description

Hybrid lead-free radiation shielding material and radiation shielding clothing using it

Disclosed is a radiation shielding material for shielding scattered X-rays and gamma rays, and a radiation shielding suit using the same.

Radiation is classified into naturally occurring radiation and artificially generated artificial radiation, and artificial radiation is widely used from X-ray imaging in the medical field to industrial sites.

Types of radiation include ionizing radiation and non-ionizing radiation, and ionizing radiation is radiation that can ionize particles by separating them from molecules.

Ionizing radiation includes alpha rays, beta rays, X-rays, and gamma rays, and alpha rays can be blocked with a material having a thickness of paper, and beta rays cannot penetrate aluminum, so there is no difficulty in shielding.

On the other hand, since X-rays and gamma rays have short wavelengths, they are easy to penetrate substances and have a harmful effect on the human body when exposed, so measures to minimize them are required.

In the case of X-rays, due to the recent rapid development of imaging medicine, X-rays are photographed on parts or welds to check integrity, or X-rays are taken to identify abnormalities inside the human body. In such X-ray imaging, since exposure is directly or indirectly to the person concerned, an X-ray shielding agent is required to minimize this.

On the other hand, in the case of gamma rays, it is generated from the collapse or transformation of the nucleus, and there is a possibility of emission of the nuclear power plant containment buildings, nuclear power plants dismantling, cancer patient wards, and accelerators handling medical gamma rays. Since gamma rays have higher energy than X-rays, they have very strong penetrating power. Such gamma rays can be blocked through concrete or a dense metal material such as iron or lead, but when metal materials are used, there is a problem that the weight of the shielding material increases due to their high density.

A radiation shielding material is required to protect humans and the environment from such a disadvantageous effect of radiation, and in many cases, a radiation shielding material is processed and used in the form of a radiation shielding suit to protect the body from radiation.

Among the radiation shielding materials used so far, the most common radiation shielding material is lead, but it is not only toxic to the human body when contacted repeatedly for a long period of time, it is heavy to use as a radiation shielding clothing, and it is a burden on the human body when worn for a long time. In addition, it has the disadvantage of inferior processability and flexibility compared to polymer composite materials.

Disclosed is to provide a hybrid lead-free radiation shielding material and a radiation shielding suit that absorbs scattered X-rays and attenuates high-level gamma rays.

As an embodiment, the content of this disclosure describes a radiation shielding material comprising an outer layer made of a scattered radiation absorbing composition and polyurethane and an inner layer made of a gamma ray shielding composition and polychloroprene, which is laminated on one surface of the outer layer.

Preferably, an outer skin layer formed by thermally bonding a waterproof cloth or a nonwoven fabric to at least one of an upper surface and a lower surface of the laminate comprising the outer layer and the inner layer may be included.

More preferably, the scattered radiation absorbing composition may include at least one selected from the group consisting of barium sulfate, a bismuth oxide compound, and magnesium oxide, iron oxide, strontium carbonate, and graphene oxide.

More preferably, the gamma ray shielding composition may include at least one of a bismuth oxide compound and tungsten, at least one of barium sulfate and magnesium oxide, iron oxide, strontium carbonate, and graphene oxide.

Even more preferably, the iron oxide, strontium carbonate, and graphene oxide may be sintered by high frequency induction heating.

As another embodiment, the content of this disclosure describes a radiation shielding suit configured to cover a wearer's body using the radiation shielding material.

Preferably, a cover for shielding around the thyroid gland may be further included.

The radiation shielding material described above and the radiation shielding clothing using the same can improve productivity by sintering by high-frequency induction heating, and have the effect of simultaneously shielding X-rays and gamma rays, and are light and deformable because they do not use lead. Excellent processability.

1 is an exploded perspective view showing a radiation shielding material according to an embodiment disclosed.

2 is an exploded perspective view showing a radiation shielding material according to another disclosed embodiment.

3 is a fabric of a radiation shielding suit using the disclosed radiation shielding material.

4 is a radiation shielding suit according to another disclosed embodiment.

5 is a front view, a side view, and a rear view of the wearer wearing the disclosed radiation shielding suit.

6 is a flowchart illustrating a method of manufacturing an outer layer of the disclosed radiation shielding material.

7 is a flowchart illustrating a method of manufacturing an inner layer of the disclosed radiation shielding material.

8 is a test analysis table of the disclosed radiation shielding material.

9 is a test analysis table of the outer layer of the disclosed radiation shielding material.

10 is a table of physical and chemical environmental resistance test results of the disclosed radiation shielding material.

Hereinafter, a preferred embodiment of the present invention and the physical properties of each component will be described in detail, but this is for explaining in detail enough that one of ordinary skill in the art can easily carry out the invention, This does not mean that the technical spirit and scope of the present invention are limited.

1 or 2, the disclosed radiation shielding material is laminated on one surface of the outer layer 10 and the outer layer formed by mixing and molding a scattering radiation absorbing composition and polyurethane, and a gamma ray shielding composition and polychloroprene (chloroprene). Includes an inner layer 20 made of ).

An outer skin layer 30 formed by thermally bonding a waterproof cloth or a nonwoven fabric to at least one of an upper surface and a lower surface of the laminate comprising the outer layer 10 and the inner layer 20 may be further formed.

At this time, the nonwoven fabric is preferably a polyethylene terephthalate (PET) nonwoven fabric.

The total thickness of the outer layer 10 and the inner layer 20 is 2.0 mm or less, and preferably 1.5 mm or less. In addition, it is preferable that the outer layer is 0.5 mm or less.

If the sum of the thicknesses of the outer layer 10 and the inner layer 20 exceeds 2.0 mm, the utilization of a molded article or device using a radioactive shielding material is degraded.

The scattered radiation absorbing composition of the outer layer 10 is at least one of barium sulfate, magnesium oxide, and bismuth oxide, iron oxide, strontium carbonate, and graphene oxide. (Graphene Oxide).

Preferably, 30 to 60 parts by weight of barium sulfate or/and 30 to 60 parts by weight of a bismuth oxide compound, and 3 to 25 parts by weight of strontium carbonate, 5 to 20 parts by weight of iron oxide, and 0.001 to 5 parts by weight of graphene oxide are included.

Particularly preferably, 35 to 45 parts by weight of barium sulfate or/and 30 to 50 parts by weight of a bismuth oxide compound, and 3 to 25 parts by weight of strontium carbonate, 10 to 15 parts by weight of iron oxide, and 0.015 to 1 parts by weight of graphene oxide are included.

When it has the above composition ratio, it is eco-friendly, its specific gravity is 4.0, and it is lighter than the specific gravity of 5.0 when it is manufactured by hybridizing lead with rubber, etc., and it is soft and has excellent deformability and workability.

In addition, the strontium carbonate, iron oxide, and graphene oxide are preferably sintered by high-frequency induction heating. In the case of sintering by high frequency induction heating, the sintering time is 2 to 5 minutes, and the sintering time can be shortened compared to 5 to 16 hours of sintering in an existing electric furnace, thereby greatly improving productivity.

The manufacturing method of the outer layer 10 includes a first mixing and pulverizing step (S100) in which at least one of barium sulfate, magnesium oxide, and bismuth oxide is mixed and pulverized to adjust the particle size, and iron oxide, strontium carbonate, and graphene oxide are mixed and nanonized. For the second mixing and pulverizing step (S130), the sintering step (S150) of sintering the composition subjected to the second mixing and crushing step at 1,000 to 1,600°C for 2 to 5 minutes, and the composition subjected to the first mixing and pulverizing step after the sintering step And a mixed molding step (S170) of mixing and molding the composition subjected to the sintering step and the polyurethane.

In the first and second mixing and pulverizing steps S100 and S130, a grinder such as a ball mill may be used, and a surfactant may be used for dispersing effect and equalization of particle size. In the case of the first mixing and pulverizing step (S100), the particle size is preferably 1 to 3 μm, and in the case of the second mixing and pulverizing step (S130), the particle size is preferably 1 to 10 nm. If the particle size is reduced through the first and second mixing and pulverizing steps, since the dispersion amount is increased relative to the same weight, the radiation shielding effect can be increased. In addition, in the second mixing and pulverizing step, it is preferable to reduce the particle size as much as possible for nano-ization.

The sintering step (S150) may use an electric furnace, but if the sintering process by high frequency induction heating is used, the sintering process that takes 5 to 16 hours can be shortened to 2 to 5 minutes, so sintering by high frequency induction heating It is desirable to do. In addition, the sintering atmosphere is preferably an inert gas atmosphere.

Through the sintering step, the absorption amount of gamma ray scattering can be improved, and the process time can be greatly shortened.

It is preferable that the weight ratio of the scattered radiation absorbing composition constituting the outer layer 10 and the polyurethane is 92:8 to 98:2. While considering processability and productivity aspects with the composition ratio, radiation shielding efficiency can be maximized.

The gamma ray shielding composition of the inner layer 20 includes at least one of bismuth oxide and tungsten, at least one of barium sulfate and magnesium oxide, strontium carbonate, iron oxide, and graphene oxide.

Preferably, 30 to 60 parts by weight of a bismuth oxide compound or/and 30 to 95 parts by weight of tungsten, 30 to 60 parts by weight of barium sulfate or/and 10 to 25 parts by weight of magnesium oxide, 3 to 25 parts by weight of strontium carbonate, 5 to 25 parts by weight of iron oxide 20 parts by weight and 0.001 to 3 parts by weight of graphene oxide are included.

Particularly preferably, 30 to 50 parts by weight of a bismuth oxide compound or/and 40 to 90 parts by weight of tungsten, 35 to 50 parts by weight of barium sulfate or/and 15 to 25 parts by weight of magnesium oxide, 3 to 10 parts by weight of strontium carbonate, 10 parts by weight of iron oxide To 15 parts by weight and 0.015 to 1 part by weight of graphene oxide.

When it has the above composition ratio, it is excellent in processability, it can shield gamma rays well, and its specific gravity is light, so it is excellent in usability as molded products and devices.

The properties of the gamma ray shielding composition may be granular, film, sheet, fabric, etc. depending on the use of the shielding material, and can be used for various shielding purposes. For example, it can be used for protective aprons, medical aprons, shielding clothes, gowns, wallpaper, building materials, medical devices, and the like.

In addition, the composition may be used alone or in combination with additives such as water or organic solvents, surfactants, resin binders, inorganic particles, and organic particles.

The manufacturing method of the inner layer 20 includes a first mixing and grinding step (S200) of mixing and grinding at least one of a bismuth oxide compound and tungsten, at least one of barium sulfate and magnesium oxide to adjust the particle size, iron oxide, strontium carbonate, and oxidation. The second mixing and crushing step (S230) of pulverizing graphene for mixing and nano-ization, the sintering step (S250) of sintering the composition subjected to the second mixing and pulverization step at 1,000 to 1,600°C for 2 to 5 minutes (S250), the first after the sintering step And a mixing and molding step (S270) of mixing and molding the composition subjected to the mixing and pulverizing step and the composition subjected to the sintering step with polychloroprene (chloroprene).

In the first and second mixing and pulverizing steps S200 and S230, a ball mill or the like may be used, and a surfactant may be used for dispersing effect and equalization of particle size.

At this time, in the case of the first mixing and pulverizing step (S200), the particle size is preferably 1 to 3 μm, and in the case of the second mixing and pulverizing step (S230), the particle size is preferably 1 to 10 nm. If the particle size is reduced through the first and second mixing and pulverizing steps, since the dispersion amount is increased relative to the same weight, the radiation shielding effect can be increased. In addition, in the second mixing and pulverizing step, it is preferable to reduce the particle size as much as possible for nano-ization.

The sintering step (S250) may use an electric furnace, but if the sintering process by high frequency induction heating is used, the sintering process that takes 5 to 16 hours can be shortened to 2 to 5 minutes, so sintering by high frequency induction heating It is desirable to do. In addition, the sintering atmosphere is preferably an inert gas atmosphere.

The sintering step (S250) facilitates the movement of electrons by a reaction between metals, thereby promoting an ionization absorption effect, thereby improving gamma ray shielding ability.

It is preferable that the weight ratio of the gamma-ray shielding composition constituting the inner layer 20 and the polychloroprene is 92:8 to 98:2. While considering processability and productivity aspects with the composition ratio, radiation shielding efficiency can be maximized.

In the method of manufacturing the radiation shielding material, first, the outer layer 10 is manufactured, and then the outer layer 10 is laminated in a mixed molding process during the manufacturing of the inner layer 20, and heat and pressure are applied to prepare the outer layer 10 by a crosslinking reaction. The temperature during the crosslinking reaction is preferably 160 to 180°C. In this case, when the outer skin layer 30 is further included, a waterproof cloth or a nonwoven fabric is thermally bonded using a calendar roll.

In this case, the weight ratio of the outer layer 10 and the inner layer 20 is preferably 40:60 to 50:50.

The outer layer 10 of the prepared radiation shielding material absorbs scattered radiation, and the inner layer 20 shields gamma rays. When gamma rays come into contact with a material, scattered radiation is generated by photoelectric effect and Compton scattering.The disclosed radiation shielding material can effectively absorb scattered radiation generated when gamma rays are shielded by the inner layer by the outer layer 10. In particular, it is excellent in blocking and absorbing gigahertz (Giga HZs) electromagnetic wave ion rays by physically reacting iron and strontium components with graphene oxide having a honeywell structure in a high-temperature amorphous region.

Therefore, it is possible to use the radiation shielding material as a radiation shielding suit for radiation shielding in a radiation area. At this time, in order to use the radiation shielding material as a radiation shielding suit, it is preferable to insert a neodymium magnet between the outer layer 10 and the inner layer 20 of the radiation shielding material for good adhesion.

In addition, the radiation shielding suit may further include a cover for radiation shielding around the thyroid gland, and it is preferable to easily wear it in the shape of a pediatric bib around the thyroid gland and lymph nodes. In addition, in order to soften the fit of the neck, it can be configured by bundling a thin radiation shielding material in two or three layers.

The radiation shielding suit using the disclosed radiation shielding material may be used as a fabric of a radiation shielding suit in a form in which only one of the outer layer 10 or the inner layer 20 is used as needed or combined with the outer layer.

<Example 1> Preparation of outer layer

2.58 parts by weight of magnesium oxide, 44.85 parts by weight of bismuth trioxide, and 37.20 parts by weight of barium sulfate were placed in a ball mill and mixed for 1 hour.

After 10.22 parts by weight of strontium carbonate, 5.0 parts by weight of iron oxide, and 0.15 parts by weight of graphene oxide were put into a ball mill and mixed for 1 hour. It was put into a high-frequency induction heating sintering machine and sintered at 1600°C for 5 minutes in a nitrogen atmosphere. After sintering, cooling at room temperature and grinding in a ball mill mixer to have an average particle size of 9 nm to 10 nm, the entire composition was mixed with polyurethane to prepare an outer layer of 0.6 mm.

<Example 2> Preparation of inner layer

32.58 parts by weight of bismuth, 53.85 parts by weight of tungsten, and 42.12 parts by weight of barium sulfate were put into a ball mill and mixed for 1 hour. 8.42 parts by weight of strontium carbonate, 5.0 parts by weight of iron oxide, and 0,15 parts by weight of graphene oxide were put into a ball mill and mixed for 1 hour. After mixing, sintering was performed at 1600° C. for about 5 minutes using a high frequency induction heating sintering machine, and the entire composition was mixed with polychloroprene to prepare a 1 mm inner layer.

After the thickness of the outer layer of Example 1 was prepared to be 1 mm, and laminated with the inner layer prepared in Example 2, a radiation shielding material of 2 mm was prepared.

The thickness of the outer layer of Example 1 was prepared to be 1.5 mm, and the thickness of the inner layer of Example 2 was prepared to be 1.5 mm, and then laminated to prepare a radiation shielding material of 3 mm.

The samples of Examples 1 to 4 were irradiated with gamma rays by requesting the Atomic Energy Research Institute/Research Institute of Standards and Science to measure the shielding rate. Comparative Examples 1 to 3 are the shielding rates when lead is used. The results are shown in [Table 1].

구분(세슘137)Classification (cesium 137)	시료 두께(mm)Sample thickness (mm)	차폐율(%)Shielding rate (%)
실시예1Example 1	0.6mm0.6mm	99
실시예2Example 2	1mm1mm	1616
실시예3Example 3	2mm 2mm	2525
실시예4Example 4	3mm3mm	3333
비교예1Comparative Example 1	1mm 1mm	55
비교예2Comparative Example 2	2mm 2mm	1010
비교예3Comparative Example 3	3mm3mm	1515

As shown in [Table 1], it can be seen that the shielding rate is considerably superior to that of lead. The gamma ray shielding material is lighter and softer than the specific gravity of lead (11.34), so that it has excellent deformability and workability, and can be used in various uses or forms.

※ Explanation of code

10; Outer layer

20; Inner layer

30; Outer layer

S100; 1st mixing and grinding step (outer layer)

S130; 2nd mixing and grinding step (outer layer)

S150; Sintering step (outer layer)

S170; Mixed molding step (outer layer)

S200; 1st mixing and grinding step (inner layer)

S230; 2nd mixing and grinding step (inner layer)

S250; Sintering step (inner layer)

S270; Mixed molding step (inner layer)

The disclosed content can be used in the field of radiation shielding materials and radiation shielding clothing.

Claims

An outer layer made of a scattered radiation absorbing composition and polyurethane; And

Radiation shielding material comprising; an inner layer formed on one surface of the outer layer and made of a gamma ray shielding composition and polychloroprene.
The method according to claim 1,

A radiation shielding material comprising an outer skin layer formed by thermally bonding a waterproof cloth or a nonwoven fabric to at least one of an upper surface and a lower surface of the laminate comprising the outer layer and the inner layer.
The method according to claim 1,

The scattered radiation absorbing composition comprises at least one selected from the group consisting of barium sulfate, bismuth oxide, and magnesium oxide, iron oxide, strontium carbonate, and graphene oxide.
The method according to claim 1,

The gamma ray shielding composition comprises at least one of a bismuth oxide compound and tungsten, at least one of barium sulfate and magnesium oxide, iron oxide, strontium carbonate, and graphene oxide.
The method according to claim 3 or 4,

The radiation shielding material, characterized in that the iron oxide, strontium carbonate, and graphene oxide are sintered by high frequency induction heating.
The method according to claim 1,

Radiation shielding material, characterized in that the weight ratio of the scattered radiation absorbing composition of the outer layer and the polyurethane is 92:8 to 98:2.
The method according to claim 1,

Radiation shielding material, characterized in that the weight ratio of the gamma-ray shielding composition and polychloroprene of the inner layer is 92:8 to 98:2.
The method according to claim 1,

Radiation shielding material, characterized in that the weight ratio of the outer layer and the inner layer is 40:60 to 50:50.
The method according to claim 1,

A radiation shielding material, characterized in that a neodymium magnet is inserted between the outer layer and the inner layer.
A radiation shielding suit configured to cover the wearer's body by using the radiation shielding material of any one of claims 1 to 9.
The method of claim 10,

Radiation shielding suit, characterized in that it further comprises a cover for shielding around the thyroid gland in the radiation shielding suit.
A method of manufacturing a radiation shielding material comprising the following steps:

(A) grinding at least one of barium sulfate, magnesium oxide and bismuth oxide;

(B) mixing and pulverizing a composition containing iron oxide, strontium carbonate, and graphene oxide, followed by sintering;

(C) mixing and molding the pulverized product through step (A) and the sintered product through step (B) with polyurethane;

(D) mixing and grinding at least one of bismuth oxide and tungsten, at least one of barium sulfate and magnesium oxide;

(E) mixing and pulverizing a composition containing iron oxide, strontium carbonate, and graphene oxide, followed by sintering;

(F) mixing and crosslinking the pulverized product through step (D), the sintered product through step (E) and polychloroprene on the molded product through step (C);
The method of claim 12,

The sintering of the step (B) or (E) is a method of manufacturing a radiation shielding material, characterized in that the sintering is performed by high frequency induction heating at 1,000 to 1,600° C. for 2 to 5 minutes.
The method of claim 12,

The method of manufacturing a radiation shielding material, further comprising the step of forming an outer skin layer by thermally bonding a waterproof cloth or a nonwoven fabric to at least one of an upper surface and a lower surface of the molded product after step (F).
A radiation shielding suit configured to cover the wearer's body by using a radiation shielding material manufactured by the method of any one of claims 12 to 14.