JPH02245688A - Label structure for indicating radiation exposure - Google Patents

Abstract

PURPOSE:To detect the quantity of radiation exposure even in the range of 10<3> - 10<4> rad. readily and to achieve an assured long life by protecting alkali halide with achromatic, transparent organic macromolecule material characterized by low hygroscopicity/water permeability. CONSTITUTION:A foamed polyethylene body which has the dimensions of 25mm in length, 25mm in width and 4mm in thickness and a hole 6 having the diameter of 10mm at the center is bonded on black paper 1 having the thickness of 0.18mm in a label structure. An aluminum foil 7 having the thickness of 0.05mm is bonded on the black paper 1 at the bottom of the hole 6. An alkali halide single crystal 9 (6mm in diameter and 3mm in thickness) is placed on the aluminum foil 7 and fixed in the hole 6 with epoxy resin 8. Acryl based pressure sensitive bonding agents 3 and 10 are applied on two places of the black paper 1. The pressure sensitive bonding agent 10 is coated with releasing paper 11. White paper 4 having the diameter of 10mm and the thickness of 0.5mm is stuck to the center of the pressure sensitive bonding agent 3. A part 2 on the black paper 1 becomes a holding part when the paper 2 is opened and closed.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is capable of displaying over a long period of time that an object to be irradiated with radiation such as The present invention relates to a radiation exposure display label structure that can be easily attached.

[Conventional technology]

In recent years, X-rays, electron beams, etc. have been used in a wide range of industrial fields, including medical equipment, food sterilization, germination suppression of onions and potatoes, crosslinking of polymer compounds, surface treatment, diagnosis of the inside of the human body, and non-destructive inspection of the inside of materials. Even when radiation is used and an irradiated body is intentionally irradiated with radiation, or when leaked radiation is detected, it is possible to easily and reliably recognize that irradiation has taken place, and, A display label that can be easily attached to an irradiated object is required from the viewpoint of work efficiency and safety.

For such requests, 10-” to 10-’rad
Until now, silver halide photography, such as the fill badge worn by radiation workers, has been used for very small amounts of radiation. However, in this method, the change in density becomes apparent only after the development process is carried out, and cannot be easily detected with the naked eye.

On the other hand, in the case of sterilizing medical instruments, suppressing sprouting of potatoes, etc., a large amount of radiation of around 10''rad is irradiated.

There are many known compositions that cause color changes when exposed to large amounts of radiation, such as compositions containing halogenated organic compounds and acid-sensitive dyes as main components.
Some methods utilize the phenomenon in which a halogenated organic compound undergoes dehydrohalogenation by irradiation with radiation, and the generated hydrogen halide acts on an acid-sensitive dye, causing the dye to change color. Specifically, there are radiation exposure display labels that have a structure in which this type of halogenated organic compound and acid-sensitive dye are dispersed in a polymeric binder and applied to paper, etc., and a pressure-sensitive adhesive is applied to the back side. . However, this type of display label has extremely low sensitivity to a radiation dose of 10'rad or less, and no color change that is suitable for practical use is observed at a radiation dose of about 103 to io'rad.

Alkali halides such as NaCQ or KBr are representative materials that exhibit coloring that is easily recognizable even at moderate irradiation doses in the range of 103 to LQ'rad. Regardless of the phase state, whether crystalline, polycrystalline, or amorphous, it exhibits clear coloration from colorless and transparent to orange or blue at a radiation dose of 101 to 10'rad. However, the disadvantage is that the coloration caused by a dose in this range fades in about 1 to 4 minutes when left exposed to natural light at room temperature and pressure, and returns to its original colorless and transparent state, making it difficult to recognize in practical terms. The inventors have
In order to improve these drawbacks, we investigated the long-term retention of alkali halide coloring by radiation irradiation, and found that it is possible to significantly extend the lifespan by adding a small amount of divalent metal to alkali halide. It has been found that the colored state can be maintained for several months by storing the seed composition in a dark place, for example by sealing it with aluminum foil. (Patent application Hei 1-319
No. 99).

[Problem to be solved by the invention]

However, even in the above case, there are problems such as the difficulty in storing alkali halides as they are because they are hygroscopic, and the need to cover them with aluminum foil or the like after irradiation. Ta.

The purpose of the present invention is to solve the problems of the above-mentioned prior art, to enable easy detection of radiation doses in the range of 103 to 1 O'rad, and to ensure a long lifespan. The object of the present invention is to provide a label structure for indicating radiation irradiation that is easy to handle in practical use.

[Means to solve the problem]

The above purpose is to protect alkali halide sensitive to radiation within the above dose range using a colorless, transparent, hygroscopic, low water permeable organic polymer material, It has a structure in which it is covered with a covering material such as a polymer material or paper, and a part of the covering material has an opening/closing function, and a pressure-sensitive adhesive is provided on the other part of the surface of the covering material. This can be achieved by forming a label structure for radiation exposure display.

[Effect]

First, by protecting the alkali halide with a colorless and transparent organic polymer material with low hygroscopicity and water permeability, it is possible to protect the alkali halide from deterioration such as moisture absorption and deliquescence caused by humidity in the air. , the colored state of the alkali halide can be observed as it is.

Next, by covering the organic polymer protector of the alkali halide with a radiation-transparent/natural light-opaque covering material such as an organic polymer material or paper, radiation irradiation can be avoided while the alkali halide is covered. It is also possible to prevent alkali halides colored by radiation from being exposed to natural light.

In addition, by configuring a part of the covering material to have an opening/closing function, the coloring state of alkali halide can be observed by keeping it open only during observation, and by immediately closing it after I1IE observation, the coloring state can be checked. It is possible to hold it for a long time.

Furthermore, by providing a pressure-sensitive adhesive layer on some other surfaces of the coating material (other than the surface with the opening/closing function), this structure can be easily attached to the surface of the irradiated object. In practical terms, the operation is extremely simple and sufficient. In addition to applying a pressure-sensitive adhesive, it is also possible to apply a pressure-sensitive adhesive double-sided sheet as a method of providing a pressure-sensitive adhesive layer. It is convenient for storage, and the structure can be easily attached to the object to be irradiated by simply removing the release paper during use.

〔Example〕

EXAMPLES Hereinafter, the radiation irradiation display label structure of the present invention will be specifically explained using Examples, but the present invention is not limited to the contents of the Examples.

Example 1 Fig. 1 is a perspective view showing the configuration of an embodiment of the radiation irradiation display label structure of the present invention, Fig. 2 is a sectional view when the opening/closing mechanism is in a half-open state, and Fig. 3 is a cross-sectional view when the opening/closing mechanism is in a half-open state. FIG. 3 is a cross-sectional view when the mechanism section is in a closed state.

First, the outline of the configuration will be explained as follows.

That is, on a black paper 1 with a thickness of 0.18 +++ m.

Vertical 25III1 with a hole 6 with a diameter of 10IilI in the center
1. A foamed polyethylene 5 with a width of 25 mm and a thickness of 4 ram is glued onto the black paper 1 at the bottom of the 66 with a thickness of 0.05 mm.
m@ aluminum foil 7 is adhered, and alkali halide single crystal 9 (diameter 6 mm
, 3 mm thick) is placed and the hole 6 is filled with epoxy resin 8.
is fixed inside. In addition, a pressure-sensitive adhesive (acrylic) 3 and IO are applied to two places on the black paper 1, the pressure-sensitive adhesive 10 is covered with a release paper 11, and the pressure-sensitive adhesive 3 is coated in the center of the pressure-sensitive adhesive 3. is 101m in diameter and 0.05m thick
Blank paper 4 with letter m is pasted. In addition, part 2 on black paper 1
is the handle when opening and closing.

When the structure with the above configuration is irradiated with radiation with the opening and closing part closed, the alkali halide single crystal 9 changes color, but because the inside of the coating is in a light shielding state, the colored state of the alkali halide is maintained for a long time. be done. W4 inspection of the colored state is performed by opening the opening/closing part using the handle half 2. At this time, since the foamed polyethylene 5 is an adherend having a smaller polarity than the black paper 1, the pressure sensitive adhesive 3 adheres to the surface of the black paper 1, and peeling occurs on the foamed polyethylene 5 surface. Since the pressure-sensitive adhesive 3 and the polyethylene foam 3 can be attached and peeled off in this way, the opening and closing portion can be repeatedly opened and closed. Further, the blank paper 4 on the pressure-sensitive adhesive M3 prevents the adhesion between the pressure-sensitive adhesive and the epoxy resin 8, and serves to facilitate opening and closing of the opening/closing part such as in *a. Also,
The purpose of the pressure-sensitive adhesive layer 10 is to adhere and hold the structure to a radiation target object. The release paper 11 is used to protect the pressure sensitive adhesive layer 10 when the structure is stored before use, and is removed when the structure is attached to an object to be irradiated. Also, aluminum? i7 is mu! of the colored state of alkali halide 9! M
This is to facilitate the process and prevent moisture from entering from the bottom of the structure.

Here, the coloring when X-ray irradiation was performed with varying irradiation doses on the structure of this example configuration using potassium chloride (KCQ) single crystal to which 0.1 mo1% of calcium (Ca) was added as an alkali halide. Table 1 shows the state and changes in the coloring state when the structure was left indoors under natural light with the opening and closing part closed. From this result, it can be seen that the colored state is maintained as it is even after three months have passed.

Table 1 The results obtained when the materials used for the structure were changed will be explained below.

First, as mentioned above, the purpose of the blank paper 4 is to prevent the adhesion between the pressure sensitive adhesive 3 and the epoxy resin 8, but instead of the blank paper 4, a polyester (polyethylene A similar effect was obtained using a terephthalate film.

A similar effect was also obtained when calcium carbonate (Ca COs ) powder was sprinkled on the pressure-sensitive adhesive layer 3 in the portion corresponding to the white paper 4 or when oil was applied.

In addition, if a silicone-based mold release agent is applied to the portion of the pressure-sensitive adhesive layer 3 corresponding to the white paper 4 or the upper surface of the epoxy resin 8, or if no pressure-sensitive adhesive is applied to the portion corresponding to the blank paper 4, or if the epoxy resin 8 is Similar results were obtained when a removable pressure-sensitive adhesive was applied that had a weak contact force against the surface. Furthermore, when a silicone resin is used instead of the epoxy resin 8, the silicone resin itself has low polarity and is removable to pressure-sensitive adhesives, so it can be opened and closed easily without using the white paper 4. Ta. In addition, instead of applying pressure-sensitive adhesives 3 and 10 on black paper 1, a so-called pressure-sensitive double-sided adhesive sheet in which pressure-sensitive adhesive was applied to the surface of the paper base material or organic polymer film base material was pasted. In this case, satisfactory results were obtained regarding the opening/closing function and the adhesion function to the irradiated object.

Next, one of the main purposes of the foamed polyethylene 5 is to block natural light, but instead of this, foams such as silicone, rubber, or polypropylene, black-colored silicone rubber boards or acrylic boards, or even wood boards can be used instead. Similar effects were obtained when a metal plate was used.

Also, the aluminum glued to the bottom of the six-six? Even when metal foil such as stainless steel or lead, or hydrophobically treated white paper or polyester film was used instead of iI7, the same effect as when aluminum foil was used was obtained.

Also, as a covering material, instead of black paper, a thickness of 0.0h
Satisfactory results were also obtained when +m white polyester film, white paper, and metal foil were used.

Note that in this case, it is not necessary to install the aluminum foil 7 on the bottom surface of the six 6.

Embodiment 2 FIG. 4 is a perspective view showing the structure of another embodiment of the radiation irradiation display label structure of the present invention, and FIG. An aluminum foil 7 is adhered to the bottom of the recess 6', an alkali halide single crystal 9 is placed on the foil, and a temperature-indicating film 12 changes from an opaque state to a transparent state by heating to a finger temperature.
is adhered to the container 13 with an adhesive, and further the container 13
It is shown that the pressure sensitive adhesive layer 10 and the release paper 11 are provided on the lower surface of the .

In the structure of this embodiment, the temperature-indicating film 12 is
As described above, since it is always opaque, the alkali halide single crystal 9 in the recess 6' is stored in a state shielded from natural light. Further, since the film 12 becomes transparent when heated by finger contact, the colored state of the alkali halide single crystal 9 can be easily observed. Furthermore, since the transparency of the film IZ is gradually lost over time, the recesses 6' become light-blocking again.

Note that the function of adhering this structure to an irradiated object is exactly the same as that of the structure of Example 1.

Here, 0.5mol1% of Ca is used as alkali halide.
The coloring state of the structure of this example using the added sodium chloride (NaCQ) single crystal was irradiated with X-rays at different doses, and the change in the coloring state when the structure was left under natural light. It is shown in Table 2. From this result, it can be seen that, as in Example 1, the colored state was maintained as it was even after three months had passed.

Table 2 [Effects of the Invention] As described above, by using the radiation exposure indicator as the radiation exposure indicator label structure of the present invention,
It is possible to easily detect radiation doses in the range of 10" to 10'rad, and ensure a long lifespan.
It was possible to provide a label structure for indicating radiation irradiation that is easy to handle in practical use.

By attaching this structure to a radiation target object, it is possible to easily identify whether the radiation target object has been irradiated or not.

[Brief explanation of drawings]

1 to 3 are diagrams showing the structure of one embodiment of the radiation irradiation display label structure of the present invention, in which FIG. 1 is a perspective view thereof, FIGS. 2 and 3 are side sectional views thereof, and FIG. 4.5 is a diagram showing the structure of another embodiment of the radiation irradiation display label structure of the present invention, FIG. 4 is a perspective view thereof, and FIG. 5 is a side sectional view thereof. 1... Black paper 2... Holding section 3... Pressure sensitive adhesive 4... White paper 5... Polyethylene foam 6... Hole 6'... Recessed part 7... Aluminum foil 8. ...Epoxy resin 9...Alkali halide single crystal 10...Pressure sensitive adhesive 11...Release paper 12...
・Thermometer tape

Claims (1)

[Claims] 1. A structure containing a radiation-sensitive substance that changes color when irradiated with radiation, the structure having radiation transparency and
A radiation irradiation display made of a material that is opaque to natural light, and characterized in that the structure is equipped with a mechanism that allows the radiation-sensitive substance to be visually observed and a mechanism that allows it to be attached to another structure. label structure. 2. The radiation-sensitive substance is an alkali halide or an alkali halide added with a divalent metal element, and
The label structure for radiation irradiation display according to claim 1, characterized in that it is embedded in a transparent and moisture-impermeable organic polymer material. 3. The above-mentioned structure in which the radiation-sensitive material is stored is plate-shaped, and has a mechanism for adhering it to another structure on one surface thereof and a mechanism for observing the radiation-sensitive material on the other surface, and The label structure for radiation irradiation display according to claim 1, characterized in that one of both surfaces is radiation transparent.