JP6238507B2 - Method for producing X-ray shielding sheet - Google Patents

Description

  The present invention relates to an X-ray shielding sheet manufacturing method capable of shielding X-rays without using lead, an X-ray shielding sheet manufactured by this method, and an X-ray shielding body.

  Lead has been used as an X-ray shielding material for a long time, but since lead is toxic to the human body, various X-ray shielding materials that do not use lead have been proposed. As this type of X-ray shielding material, those using barium compounds, tin or tin compounds, antimony compounds, tungsten sintered bodies, and those using bismuth or bismuth compounds are known (for example, Patent Document 1, Patent Document 1). 2 and 3).

JP 2007-332235 A (refer to the description of paragraphs 0003 to 0006 of the specification) JP-A-55-57200 JP 2001-83288 A

By the way, as a sheet-like product for the purpose of current X-ray shielding, a rubber sheet containing an X-ray shielding material such as tungsten is commercially available. However, since the strength against tearing and pulling is weak, fabrics and resins It is necessary to use it with reinforcement. In addition, this type of sheet-like product has a problem that it is difficult to use as a surface material because many of the colors are brown to black. Therefore, it has a three-layer structure in which the surface of a rubber sheet or the like containing an X-ray shielding material is covered with a cloth or a resin sheet.
However, in such a conventional three-layer X-ray shield, even if the material deteriorates due to secular change or repeated bending during use, even if a crack or tear occurs in the middle rubber sheet, it is difficult to detect an abnormality. There is a problem.
Further, since the conventional X-ray shield is manufactured by separately forming the X-ray shield sheet and the jacket material and partially bonding the X-ray shield sheet to the jacket material, During use of the body, the jacket material and the X-ray shielding sheet are easily peeled off, and there is a possibility that X-rays may enter through gaps caused by deviation due to peeling.

In order to solve the above problems, the invention according to claim 1 is a method of manufacturing an X-ray shielding sheet in which a layer of a mixture of a polymer material and a lead-free X-ray shielding material is formed on a cloth surface. ,
Prepare a two-component curable silicone resin composed of a main agent and a curing agent as the polymer material, prepare a plain weave fabric having a silage surface on at least one surface, and each of the main agent and the curing agent A mixture of bismuth oxide added thereto and a solvent added to adjust the viscosity to produce the mixture containing 12 parts by weight of the silicone resin and 88 parts by weight of bismuth oxide, and the film thickness after drying the mixture The step of coating and drying the silage surface of the dough to 500 μm or less is repeated a plurality of times until the film thickness of the mixture after drying reaches a predetermined film thickness, and X-ray shielding is applied to at least one surface of the dough. A layer is formed so that the cloth and the X-ray shielding layer are integrated, and the lead-containing X-ray shielding equivalent to a sheet thickness of 1.86 mm and a shielding performance of 0.35 mm Pb is obtained by enclosing a lead-containing sheet in the jacket material. It is equivalent to a sheet thickness of 1.56 mm, including the thickness of the cloth, and has the same degree of bending resistance according to JIS L 1096A method (cantilever method), according to JISK 6301 (1975). This is a method for obtaining an X-ray shielding sheet that exceeds the lead-containing X-ray shielding sheet in each of the tensile strength and tear strength, and the X-ray shielding ability test according to JIS Z 4501 (test tube voltage 150 kV).
As described in claim 2, the X-ray shielding material is preferably 75% by weight or more by weight with respect to the X-ray shielding sheet.
According to a third aspect of the present invention, a layer coated with the polymer material not containing the X-ray shielding material may be formed on the surface of the uppermost X-ray shielding layer.

According to the present invention, since the cloth and the X-ray shielding layer are integrated with a high degree of adhesion, an X-ray shielding sheet having high strength against tearing and pulling can be obtained. Even if the material deteriorates, early detection of abnormalities is easy. Moreover, since the cloth and the X-ray shielding layer are integrated, the cloth and the X-ray shielding layer are not easily peeled off, and a gap due to deviation is less likely to occur.
Furthermore, since a functional layer such as a colored layer or water repellency can be provided on the surface layer, an X-ray shielding sheet having a desired color and pattern and a desired function can be obtained.

Hereinafter, preferred embodiments of the present invention will be described in detail.
In this embodiment, a polymer material and a lead-free X-ray shielding material are prepared, and a mixture thereof is prepared. And after apply | coating this mixture to one surface of a cloth | dough and forming an X-ray shielding layer, the process of applying the said mixture on this further is repeated.

[Polymer material]
The polymer material is not particularly limited as long as it is flexible so that it can be applied to a cloth and integrated and can be used for clothing or the like.
For example, in addition to natural polymer materials, general-purpose resins such as polyolefins, urethane resins, vinyl chloride resins, vinyl acetate resins, fluororesins, (meth) acrylic resins, engineering plastics obtained by vinyl polymerization, and super engineering plastics A synthetic polymer material such as a silicone resin can be used.
The polymer material may be a one-component curable type or a two-component curable type composed of a main agent and a curing agent.

[X-ray shielding material]
Examples of X-ray shielding materials having an X-ray shielding ability equal to or higher than that of lead and having no toxicity such as lead include tungsten (W), tin (Sn), bismuth (Bi), and compounds thereof. .
WO 2006/090629 discloses at least one selected from lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), samarium (Sm), europium (Eu), and gadolinium (Gd). X-ray shielding materials composed of oxide powders of various elements have been proposed.
The X-ray shielding material may be a single substance, or two or more kinds of the X-ray shielding materials may be mixed and used.

[Mixing process]
The mixing ratio of the X-ray shielding material to the polymer material is determined by the relationship between the type of the X-ray shielding material, the type of the polymer material, and the thickness of the X-ray shielding sheet and the shielding ability of the X-ray. An optimal value can be obtained. When the ratio of the X-ray shielding material is large, the X-ray shielding ability is increased, and the same shielding performance as that of the conventional product can be obtained with a thin and light X-ray shielding sheet. However, when the ratio is too high, the sheet strength is lowered. Moreover, when the said ratio is small, the weight of an X-ray shielding sheet will become light, but the shielding ability of X-rays will become low. When using the above-mentioned polymer material and X-ray shielding material, the X-ray shielding material may be mixed so that the X-ray shielding material is 75% or more by weight with respect to the X-ray shielding sheet.

[Cloth]
The material and form of the dough for applying the mixture obtained in the mixing step are not limited as long as they can be integrated with the mixture by applying the mixture. It may be in the form of a sheet or film, and is preferably a knitted fabric such as a woven fabric, a knitted fabric, or a nonwoven fabric. It is preferable to smoothen the surface of the fabric. Examples of the smoothing process include calendering and silage processing in which pressing is performed with a hot roll.

[Coating]
The mixture is applied to the surface of the dough subjected to the smoothing process so that the film thickness after drying becomes 500 μm or less according to the composition of the mixture. As the coating means, known ones such as roll coating, die coating, gravure coating, comma coating and screen printing can be used.
Drying is performed in a temperature range in which bubbles do not occur inside the mixture.

On the first X-ray shielding layer formed by drying, the mixture is applied and dried so that the film thickness after drying becomes about 500 μm or less. This process is repeated until the film thickness of the laminated body of X-ray shielding layers reaches a predetermined dimension.
In addition, a colored layer, a stain-proof layer, a water-repellent layer, or the like may be formed on the surface of the uppermost X-ray shielding layer. When a polymer material having a stainproof function or a water repellent function is used, the uppermost X-ray shielding layer can be used as it is as a stainproof layer or a water repellent layer. You may apply the polymer material which does not contain the said mixture or X-ray shielding material which raised the ratio of the polymeric material to the surface of the uppermost X-ray shielding layer.

  Further, when the polymer material does not have the antifouling function or the water repellent function, the mixture or polymer material added with an additive for causing the antifouling function or the water repellent function is used as the uppermost X-ray shielding layer. Apply to the surface of the. Further, since some X-ray shielding materials have unique colors, in order to finish the X-ray shielding sheet to a desired color, a dye for finishing the desired color without including the X-ray shielding material The above-described polymer material containing sapphire may be applied to the surface of the uppermost layer.

[Manufacture of X-ray shield]
In order to produce an X-ray shielding body such as clothing using the X-ray shielding sheet obtained in the above procedure, the X-ray shielding sheet is cut into a predetermined size and shape, or is preliminarily formed into a predetermined size and shape. The mixture is applied onto the formed dough to obtain an X-ray shielding sheet having a predetermined size and shape. The X-ray shielding sheets having a predetermined size and shape are overlapped at the edges, and joined by bonding or stitching at the overlapped portions. By reducing the thickness of the X-ray shielding layer at the edge to be overlapped, it is possible to suppress an extreme change in the thickness of the joint portion. When there is a possibility that a gap is formed in the joint portion, the mixture may be applied to the joint portion.

[Example]
An example of the X-ray shielding sheet of the present invention will be described below.
(1) Fabric Material and knitting: 100% polyester Plain weave Pretreatment: Water repellent treatment (drying temperature: 130 ° C SET: 180 ° C)
Silage treatment (170 ° C. × 50 kg / cm ² : single side)

(2) Mixture A bismuth oxide X-ray shielding material was mixed with a two-part curable silicone resin composed of the main agent (A) and the curing agent (B) to obtain a mixture.
The main agent, curing agent, solvent and bismuth oxide used are as follows.
Main agent (A): Silicone resin main agent Curing agent (B): Silicone resin curing agent Solvent: Toluene Mixing procedure: 12 parts by weight of main agent (A) added with 88 parts by weight of bismuth oxide and curing agent (B) 12 Equal amounts (100 parts by weight) of bismuth oxide added to 88 parts by weight were added to parts by weight, and toluene was added to adjust the viscosity.

(3) Coating
(i) The clearance was adjusted so that the coating film thickness would be 50 μm to 300 μm after drying, and the mixture was applied to the silage surface of the dough by the comma coating method. Drying was performed at 100 ° C. for 5 minutes. Thus, the first X-ray shielding layer was obtained.
(ii) On this first X-ray shielding layer, the clearance was adjusted so that the coating film thickness would be 50 μm to 300 μm after drying, and the mixture was applied by a comma coating method. Drying was performed at 100 ° C. for 5 minutes. In this way, a second X-ray shielding layer was obtained.
(iii) The process of (ii) was repeated until the film thickness of the layer of the mixture was 1.39 mm (the sheet thickness including the dough was 1.56 mm).

(4) Result Using the X-ray shielding sheet obtained by the above procedure, the X-ray shielding ability was tested.
The test was conducted by the following method.
Physical property measurement method:
Tensile strength and elongation test JIS is an integrated fabric and X-ray shielding layer.
According to the test method of K 6301 (1975)
It was.
Tear test JIS is an integrated fabric and X-ray shielding layer.
According to the test method of K 6301 (1975)
It was.
Bending measurement JIS L 1096A method (cantilever method)
More measurements were made.
X-ray shielding ability test JIS Z 4501 (test tube voltage 150 kV) test
The test method was used.
Decrease the attenuation rate by applying an X-ray beam to the test product.
The lead equivalent corresponding to the weakness is taken as the performance of the test product.
The attenuation rate is the relative value of the dose rate when the test product or standard lead plate is placed relative to the dose rate when the test product or standard lead plate is not placed.
The attenuation rate curve of the standard lead plate is created from the lead thickness and attenuation rate of the standard lead plate, the lead thickness corresponding to the attenuation rate of the test product is obtained by interpolation, and the lead equivalent (mmPb) of the test product is obtained.
The test results are shown in the following table.

  In addition, in the comparative example, it tested on the same conditions as an Example about the conventional X-ray shielding sheet which included the lead-containing sheet in the jacket material.

From this result, it can be seen that the thickness of the X-ray shielding sheet of the present invention can be reduced and the tensile strength and tear strength can be significantly increased compared to the conventional X-ray shielding sheet containing lead.
Therefore, if an X-ray shielding body such as clothing is manufactured using the X-ray shielding sheet of the present invention, it can be made thin, so that it is easy to work in a state where an operator is wearing, and there is strength and the cloth and X Since it is difficult for the wire shielding layer to peel off, the work can be performed with peace of mind.

Although preferred embodiments and examples of the present invention have been described, the present invention is not limited to the above description.
For example, in the above embodiment, a two-pack type silicone resin is taken as an example, but a one-pack type silicone resin may be used.

  The X-ray shielding sheet obtained by the method of the present invention can be suitably used particularly for sheets, curtains, clothes, partitions, etc. that cover devices at medical sites, but can be exposed to X-rays even outside medical sites. It can be widely applied to seats, clothes, curtains, partitions, etc.

Claims (3)

In the method of manufacturing an X-ray shielding sheet in which a layer of a mixture of a polymer material and a lead-free X-ray shielding material is formed on the cloth surface,
Prepare a two-component curable silicone resin consisting of a main agent and a curing agent as the polymer material,
Prepare a plain weave fabric with a silly surface on at least one surface,
Blending each of the main agent and the curing agent with bismuth oxide added thereto and adding a solvent to adjust the viscosity to produce the mixture containing 12 parts by weight of the silicone resin and 88 parts by weight of bismuth oxide;
The process of applying the mixture to the silage surface of the dough so that the film thickness after drying is 500 μm or less and drying the mixture multiple times until the film thickness of the mixture after drying reaches a predetermined film thickness, Forming an X-ray shielding layer on at least one surface of the fabric to integrate the fabric and the X-ray shielding layer;
Compared to a lead-containing X-ray shielding sheet with a sheet thickness of 1.86 mm and a shielding performance of 0.35 mm Pb, the sheet thickness including the thickness of the cloth is equivalent to 1.56 mm. L 1096A method (cantilever method) has the same degree of bending resistance, tensile strength and tear strength according to JISK 6301 (1975), X-ray shielding according to JIS Z 4501 (test tube voltage 150 kV) Obtaining an X-ray shielding sheet that exceeds the lead-containing X-ray shielding sheet in each of the capability tests;
The manufacturing method of the X-ray shielding sheet characterized by these. The method for producing an X-ray shielding sheet according to claim 1, wherein the X-ray shielding material is 75% or more by weight with respect to the X-ray shielding sheet. The X-ray shielding sheet according to claim 1, wherein a layer coated with the polymer material not containing the X-ray shielding material is formed on the surface of the uppermost X-ray shielding layer. Production method.