WO2004104291A1

WO2004104291A1 - Fabric for screening radiation and method for manufacturing the same

Info

Publication number: WO2004104291A1
Application number: PCT/KR2003/002686
Authority: WO
Inventors: Yong-Jin Kim
Original assignee: Buffalo Co., Ltd.
Priority date: 2003-04-30
Filing date: 2003-12-08
Publication date: 2004-12-02
Also published as: KR100513842B1; KR20040093878A; AU2003304135A1

Abstract

A fabric for screening radiation and a method for manufacturing the fabric are disclosed. The fabric for screening radiation has a coating layer made of polyurethane resin on a fabric surface. Powdered barium sulfate (BaSO4) and radiation contrast medium compound such as organic iodine are uniformly dispersed in the coating layer. This radiation-screening fabric is light and ensures good feeling and safety to a wearer. In addition, the radiation-screening materials uniformly dispersed on the fabric surface well screen the radiation. Moreover, when the fabric is made into clothes, an apron or a hat, persons who may be exposed to radiation for a long time may conveniently wear them.

Description

FABRIC FOR SCREENING RADIATION AND METHOD FOR MANUFACTURING THE SAME

TECHNICAL HELD The present invention relates to a fabric for screening radiation and a method for manufacturing the fabric, and more particularly to a fabric for screening radiation and a method for manufacturing the fabric, which is light and excellent in safety and wearing and also gives better radiation-screening effects since radiation-screening materials are uniformly dispersed on the surface of the fabric.

BACKGROUND ART

It is well known that exposure to radiation such as X-ray or gamma ray brings about serious diseases and disorders such as the production of cancer, hereditary disorder, cataract or the like. Accordingly, International Radiation Protection Committee begins in 1934 to restrict usage of radiation (0.2 R/day), and International Radiation Protection Recommendations (ICRP-26) is adopted in 1977. Subsequently, a guidebook is issued for decreasing exposure to radiation of patients, workers and protectors concerned in X-ray diagnosis, medical cure or nuclear medical science, and laws for regulating usage of radiation are established in various countries in accordance to the guidebook.

As mentioned above, exposure to radiation should be restricted to the minimum since it is very harmful to the human body. However, the persons directly or indirectly dealing the radiation like radiation technologists or doctors in hospitals or persons concerned in nuclear power plants may be continuously exposed to radiation due to the nature of their work, so more attention is required. Thus, optimal installation and equipment are required to reasonably decrease the exposure to radiation of persons and environments concerned in radiation, and even though radiation is exposed very little to them, best efforts should be made to protect healthy tissues except a medically treated portion of the patient.

In order to screen radiation, a person generally wears a gown made of a sheet, which is formed by dispersing lead components in rubber and then extruding it. The gown made in such a way effectively screens radiation, but it is very heavy as much as 5 to 10 kg, thereby giving bad feeling in wearing. Thus, the gown is commonly not worn by persons who are not positioned in several dangerous districts in the nuclear power plant. In particular, the radiation used in a hospital is in low doses and has no danger of direct exposure, but the radiation is only exposed indirectly due to diffraction of the radiation. Due to that reason, persons concerned in the hospital do not feel the necessity of wearing the heavy gown and they are not willing to tolerate the inconvenience caused by the heavy gown, such as low efficiency in work.

Thus, many researches are made for development of a radiation-screening fabric which may sufficiently eliminate danger of direct and indirect exposure to radiation and which is light and excellent in wearing with no harm to the human body. US Pat. No. 3,194,239 discloses a method for making a radiation-absorbable fabric with the use of wires made of alloys for the purpose of absorption of radiation, but it is bad in _. flexibility and radiation-screening ability. In addition, Korean Pat. Filing No. 10-2000-7003445 discloses a method for combining a mixture, in which metal particles are dispersed, on a fabric surface, but it is bad in endurance in spite of good radiation-screening effects.

Meanwhile, Korean Patent Publication No. 2000-7084, filed by the inventor of the present invention, discloses a cloth to which radiation-screening ability is given by applying barium sulfate, generally used as a contrast medium, to a fabric. In order to apply barium sulfate powder to a fabric, it is required to disperse the barium sulfate powder in a binder such as polyurethane resin and then treat it on the fabric surface. However, barium sulfate has extremely bad dispersibility to polyurethane resin, so it is not easy to form a uniform radiation-screening layer.

DISCLOSURE OF INVENTION

The present invention is designed to solve the problems of the prior art, and therefore an object of the invention is to provide a fabric for screening radiation, which is light and excellent in safety and wearing, and also gives good radiation-screening effects since radiation-screening materials are uniformly dispersed on the surface of the fabric.

In order to accomplish the above object, the present invention provides a fabric for screening radiation, wherein a coating layer made of polyurethane resin is formed on a surface of the fabric, and barium sulfate (BaSO₄) and organic iodine radiation contrast medium compound in a powder state are uniformly dispersed in the coating layer.

In the fabric for screening radiation according to the present invention, it is preferable that a mixture weight ratio (B/A) of the barium sulfate (A) and the organic iodine radiation contrast medium compound (B) is 1/1000 to 1/2, and the organic iodine radiation contrast medium compound may be selected from the group consisting of iodo trijoic acid, io oxyglic acid, iothalamic acid, io octro citric acid, iotrolan, iopionic acid, iopamidol, iohexol, sodium ioperiodate, iodoamide, and their mixtures. In addition, alkali earth metal compound and/or bismuth compound in a powder state may be further dispersed in the coating layer in addition to barium sulfate and organic iodine radiation contrast medium compound so as to improve the radiation-screening ability more.

In another aspect of the invention, the present invention also provides a method of manufacturing a fabric for screening radiation, which includes (a) coating and drying a composition for forming an adhesive layer, which includes 100 wt% of two-component polyurethane resin, 20 to 50 wt% of methylethylketone, 5 to 40 wt% of toluene, 1 to 10 wt% of cross-link agent and 1 to 20 wt% of acrylic resin, on a surface of a fabric; and (b) coating and drying a composition for forming a radiation-screening layer, which includes 100 wt% of one-component polyurethane resin, 100 to 500 wt% of barium sulfate, 0.5 to 50wt% of organic iodine radiation contrast medium compound, 20 to 50wt% of methylethylketone and 5 to 40 wt% of toluene, on the adhesive layer formed in the step (a).

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects, and advantages of preferred embodiments of the present invention will be more fully described in the following detailed description, taken accompanying drawings. In the drawing:

FIG. 1 is a schematic sectional view showing a fabric manufactured according to a method of the present invention. BEST MODES FOR CARRYING OUT THE INVENTION

Hereinafter, a fabric for screening radiation and its manufacturing method according to the present invention will be described in detail. As described before, barium sulfate is a contrast medium which is used for photographing digestive organs and safe for the human body, and it shows relatively excellent X-ray screening (or, absorbable) ability. However, barium sulfate has very great density of 4.5 g/cm³ and bad misibility to polyurethane resin, so, if barium sulfate powder is dispersed in polyurethane resin and then treated on a fabric surface like the prior art, it is difficult to form a radiation-screening layer in which barium sulfate is uniformly distributed, due to its bad dispersibility. Thus, in order to give good radiation-screening ability to a fabric with the use of barium sulfate, an amount of barium sulfate is necessarily added more than required, thereby imposing a heavy burden in weight and sense of wearing. In order to solve the problem, the inventor repeated researches for radiation-screening materials having good dispersibility against polyurethane resin together with giving good radiation-screening effects, and eventually found that organic iodine radiation contrast medium compound may be suitable for the object of the invention and then completed this invention. That is to say, the fabric for screening radiation according to the present invention has a coating layer made of polyurethane resin, which is formed on a surface thereof, and the organic iodine radiation contrast medium compound in a powder state is uniformly dispersed in the coating layer. The organic iodine radiation contrast medium compound may use well-known organic iodine compounds, used as a contrast medium for absorbing radiation, such as iodo trijoic acid, io oxyglic acid, iothalamic acid, io octro citric acid, iotrolan, iopionic acid, iopamidol, iohexol, sodium ioperiodate, iodoamide or the like, alone or in mixture. The organic iodine radiation contrast medium compound absorbs radiation and marvelously weakens transmissibility of radiation. In addition, differently from barium sulfate, the organic iodine radiation contrast medium compound has a density not so much different from polyurethane resin in the aspect of chemical structure, and very excellent dispersibility since it makes H-bond together with polyurethane resin, and it is safe even in contact with the human body. However, the organic iodine radiation contrast medium compound is preferably mixed with barium sulfate for the purpose of cost reduction. A preferable mixture weight ratio (B/A) of the barium sulfate (A) and the organic iodine radiation contrast medium compound (B) is 1/1000 to 1/2, considering costs and uniformity of radiation-screening properties. As mentioned above, if barium sulfate and organic iodine radiation contrast medium compound are dispersed in polyurethane resin and then coated on a fabric, it is possible to obtain a fabric with good radiation-screening ability with giving no harm to the human body. In addition, for further improvement of the radiation-screening ability in the present invention, alkali earth metal compound such as calcium hydroxide, calcium carbonate, magnesium hydroxide, magnesium oxide and magnesium carbonate, and bismuth compound such as bismuth oxycarbonate may be further added. In addition, in order to form a stronger coating layer for screening radiation, an adhesive layer may be formed on the fabric surface before the coating layer is formed. For the fabric used in the present invention for screening radiation, all kinds of fabrics such as a knitted fabric or a non-woven fabric in addition to a woven fabric weaved by warps and wefts may be used if it is formed two dimensionally and may be cut into a shape such as cloth, hat, curtain, partition or tent. In addition, as for a fiber for forming the fabric, a synthetic fiber such as polyester fiber and nylon fiber and a natural fiber such as cotton, wool and rayon may be all used.

In the present invention, the method of forming a radiation-screening layer on the fabric surface may adopt known manners such as a laminating manner, a bonding manner, a direct (or, floating knife) manner, a gravure manner and a padding manner, and particularly uses the following method.

First, a composition for forming an adhesive layer, which includes 100 wt% of two-component polyurethane resin, 20 to 50 wt% of methylethylketone, 5 to 40 wt% of toluene, 1 to 10 wt% of cross-link agent and 1 to 20 wt% of acrylic resin, is coated on a surface of a fabric, and then dried. The formed adhesive layer plays a role of keeping a binding force between the fabric and the radiation-screening layer strongly.

Subsequently, a composition including 100 wt% of one-component polyurethane resin, 100 to 500 wt% of barium sulfate, 0.5 to 50wt% of organic iodine radiation contrast medium compound, 20 to 50wt% of methylethylketone and 5 to 40 wt% of toluene is mixed uniformly and then coated on the adhesive layer formed on the fabric surface, and then dried to form a radiation-screening layer. The composition for forming the radiation-screening layer may further include 0.5 to 30 wt% of alkali earth metal compound and/or 0.5 to 50 wt% of bismuth compound, when required.

FIG. 1 is a schematic sectional view showing the fabric 10 for screening radiation, which is manufactured as mentioned above. Referring to FIG. 1, an adhesive layer 14 is formed on the surface of a fabric 12 in order to keep a binding force between the fabric 12 and a radiation-screening layer 16 strongly. On one surface of the adhesive layer 14, the radiation-screening layer 16 wherein barium sulfate and organic iodine radiation contrast medium compound are uniformly dispersed in polyurethane resin is formed. Barium sulfate exists with being partially condensed in the radiation-screening layer 16, while organic iodine radiation contrast medium compound is uniformly dispersed in the radiation-screening layer 16, so all parts of the fabric exhibit a radiation-screening ability over a certain extent. Consequently, in the fabric for screening radiation manufactured as above according to the present invention, a coating layer made of polyurethane resin is formed on the fabric surface, and barium sulfate (BaSO₄) and organic iodine radiation contrast medium compound are uniformly dispersed in the coating layer in a powder state. On the. fabric surface, an adhesive layer for keeping a binding ability between the fabric and the radiation-screening layer strongly may be selectively formed, of course.

The fabric for screening radiation according to the present invention may be used in a laminated state according to the desired usage for radiation screening. That is to say, at least two folds of the fabric for screening radiation according to the present invention, in which the coating layer made of polyurethane resin is formed on the fabric surface, and barium sulfate (BaSO₄) and organic iodine radiation contrast medium compound are uniformly dispersed in the coating layer in a powder state, may be bonded using an adhesive. If required, a lining fiber made of mesh materials may be further bonded on a surface of the coating layer which is to be contacted with the human body, for better contact with the human body.

Hereinafter, the present invention will be described in more detail with an embodiment. However, the embodiment of the present invention may be modified in various ways, and the present invention should not be interpreted to be limited by the following embodiment. The embodiment of the present invention is provided for those ordinarily skilled in the art to understand the present invention better.

Embodiment 1

100 wt% of two-component polyurethane resin, 40 wt% of methylethylketone, 20 wt% of toluene, 5 wt% of cross-link agent and 5 wt% of acrylic resin are uniformly mixed, and then 50 g/m² of the mixture is coated on a surface of a polyester woven fabric using a floating knife with a thickness of 1.5 mm, and then dried for 60 seconds at 130°C to form an adhesive layer. Subsequently, 100 wt% of one-component polyurethane resin, 200 wt% of barium sulfate, 50wt% of iodo trijoic acid, 40wt% of methylethylketone and 20 wt% of toluene are uniformly mixed, and then 30 g/m² of the mixture is coated on the formed adhesive layer using a floating knife with a thickness of 2.0 mm, and then dried for 60 seconds at 130°C to make the fabric on which a radiation-screening layer is formed.

The radiation-screening test is conducted for the fabric manufactured according to the embodiment 1 in Linear Accelerator Center of Pohang Engineering Collage. The fabric of the embodiment 1 is cut into 50x50 cm, and then measured 10 times with changing a screening rate according to source and average energy stated in Table 1, and then their average value and variation rate are filled in Table 1. Table 1

Comparative Example 1

A fabric having a radiation-screening layer is manufactured in the same way as the embodiment 1, except that iodo trijoic acid, which is an organic iodine radiation contrast medium compound, is not added when the radiation-screening layer is formed. The fabric of the comparative example 1 is measured in the same way as the embodiment 1, and its radiation-screening rate and variation rate are filled in Table 2.

Table 2

Seeing Tables 1 and 2, it is found that the fabric of the embodiment 1 which contains barium sulfate and organic iodine radiation contrast medium compound as a radiation-screening agent shows more excellent radiation-screening ability than the fabric of the comparative example 1 which contains only barium sulfate, and the variation rate is also lower in the embodiment 1 since the radiation-screening ability is uniform over the entire surface of the fabric of the embodiment 1.

INDUSTRIAL APPLICABILITY As mentioned above, the fabric for screening radiation according to the present invention is light and excellent in safety and wearing, and also gives good radiation-screening effects since radiation-screening materials are uniformly dispersed on the surface of the fabric. Thus, persons who may be exposed to radiation for a long time may always conveniently wear a cloth, apron or cap, which is made by the fabric.

The present invention has been described in detail. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.

Claims

What is claimed is:

1. A fabric for screening radiation, wherein a coating layer made of polyurethane resin is formed on a surface of the fabric, and barium sulfate (BaSO₄) and organic iodine radiation contrast medium compound in a powder state are uniformly dispersed in the coating layer.

2. The fabric for screening radiation according to claim 1, wherein a mixture weight ratio (B/A) of the barium sulfate (A) and the organic iodine radiation contrast medium compound (B) is 1/1000 to 1/2.

3. The fabric for screening radiation according to claim 1, wherein the organic iodine radiation contrast medium compound is selected from the group consisting of iodo trijoic acid, io oxyglic acid, iothalamic acid, io octro citric acid, iotrolan, iopionic acid, iopamidol, iohexol, sodium ioperiodate, iodoamide, and their mixtures.

4. The fabric for screening radiation according to claim 1, wherein alkali earth metal compound and/or bismuth compound in a powder state is further dispersed in the coating layer.

5. A fabric for screening radiation wherein more than one layer of the fabric defined in claim 1 is laminated.

6. A method of manufacturing a fabric for screening radiation, comprising:

(a) coating and drying a composition for forming an adhesive layer, which includes 100 wt% of two-component polyurethane resin, 20 to 50 wt% of methylethylketone, 5 to 40 wt% of toluene, 1 to 10 wt% of cross-link agent and 1 to 20 wt% of acrylic resin, on a surface of a fabric; and

(b) coating and drying a composition for forming a radiation-screening layer, which includes 100 wt% of one-component polyurethane resin, 100 to 500 wt% of barium sulfate, 0.5 to 50wt% of organic iodine radiation contrast medium compound, 20 to 50wt% of methylethylketone and 5 to 40 wt% of toluene, on the adhesive layer formed in the step (a).

7. The method for manufacturing a fabric for screening radiation according to claim 6, wherein the composition for forming the radiation-screening layer further includes 0.5 to 30 wt% of alkali earth metal compound and/or 0.5 to 50 wt% of bismuth compound.