JP2001221894A - Radiation conductive material and its production method, and solid sensor using radiation conductive material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a radiation conductive material capable of forming a thin film, having a satisfactory radiation photocontrol characteristic, withstanding high electric field and causing no generation of charge trapping. SOLUTION: An alcohol-soluble nylon, nylon-6, nylon-66 complex and bismuth iodide are put in a vessel 101 containing alcohol, and this is dissolved in the alcohol on a heating device 102. Alcohol is evaporated from the alcohol solution to make it a high viscous complex material of nylon-6, nylon-66 complex and inorganic material, and the high viscosity complex material is formed in film on a substrate 103.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radiation-conductive material which is sensitive to radiation, and a radiation-conductive material which can record image information as a pattern (electrostatic latent image) of an electrostatic charge formed by irradiation of radiation. The present invention relates to a solid-state sensor including a radiation conductive layer made of a conductive material.

[0002]

2. Description of the Related Art Conventionally, in medical radiography,
Radiation-sensitive photoconductors (for example, a-S
An e (amorphous selenium) plate or the like is used as a photoreceptor (electrostatic recording medium), and a system is disclosed in which an electrostatic latent image due to radiation formed on the selenium plate is read by a laser beam or a large number of electrodes (for example, there is disclosed a system). U.S. Pat.
No. 5, No. 5268569, No. 5354982, No. 4535468
No., "23027 Method and devisce for recording and t
ransducing an electromagnetic energy pattern "; Rese
rch Disclosure June1983, JP-A-9-5906, U.S. Pat.No. 4,961,209, "X-ray imaging using amorphous sele
nium "; Med Phys.22 (12) etc.).

[0003] These have higher resolution than the indirect imaging method using a TV image pickup tube, which is a well-known imaging method, and the radiation required for imaging as compared with the zero radiography method (electro X-ray photography). It is excellent in that the irradiation amount is small.

Meanwhile, the radiation conductive material used for the photoconductor of the above system is a good insulator in a dark state, and has durability even under a high electric field (10 ⁵ to 10 ⁶ Vcm ^-1 ). In some cases, it is necessary to have a high radiation absorption efficiency and to generate a high charge. Further, the radiation conductive material needs to be capable of forming a thin film so that the generated charges can move in the film without being trapped.

However, although the radiation conductive material Se generally used in the above-mentioned prior art is excellent in durability and can generate a high charge, it cannot be said that the radiation absorption efficiency is sufficient, and the charge is not sufficient. It is difficult to form a thin film without trapping. In addition, Se is the Poisonous and Deleterious Substances Control Law No. 2
It is designated as a poisonous substance, and it is preferable not to contain it from the viewpoint of ensuring safety in the manufacturing process.

From such a viewpoint, as a radiation conductive material replacing Se, US Pat. No. 5,556,716 discloses a VB-VI
B, VB-VIIB, IIB-VIB, IIB-VB,
IIIB-VB, IIIB-VIB, IB-VIB, I
As an example of a combination of an inorganic material and an organic material of VB-VIIB, BiI ₃ , PbI ₄ , PbI ₃ , Bi
And ₂ S ₃ 11- nylon, PVK (N-polyvinyl carbazole), PMMA radio-conductive material comprising an inorganic / organic composite material (methacrylic resin) has been described.

[0007] Science, 273 (1996), 632 includes Bi.
Radio-conductive material I ₃ and 11-nylon (50/50 wt%) is described to exhibit good radiation photo conductive properties.

Although these techniques are excellent in radiation absorbing ability, it is difficult to form a high-quality film in a large area.
In addition, a heavy element compound such as BiI ₃ which has been unsuitable as a radiation conductive material due to various problems that a dark current at room temperature is large and cannot withstand a high electric field is used to form a high-quality thin film. By forming a composite with an organic material (polymer) having a low dark current and good dielectric properties, it is realized to be used as a radiation conductive material.

[0009]

However, the above inorganic /
Since the radiation conductive material made of an organic composite material is a composite of an inorganic material and an organic material, the dispersibility of the inorganic material (inorganic fine particles) is likely to deteriorate. That is, inorganic /
As shown in FIG. 8, a radiation conductive material made of an organic composite material is obtained by melting an organic material 81 on a substrate 83 heated on a hot plate 82 and adding inorganic fine particles to the melted organic material 81. In addition, since the production is performed by a so-called melt deposition method in which a film is formed by stirring with a spatula or the like, it is difficult to uniformly disperse inorganic fine particles in an organic material. If the dispersibility of the inorganic fine particles is poor, the radiation photocon characteristics will be deteriorated due to the presence of the aggregated inorganic fine particles in the formed thin film, and the high electric field Or charge traps are likely to occur.

In addition, since a radiation conductive material composed of an inorganic / organic composite material is obtained by diluting an inorganic material having radiation conductivity with an organic material, the composite material is required to ensure a sufficiently high radiation absorption. It is necessary to increase the content of the inorganic material therein (in the case of BiI ₃ / Nylon 11, 65 wt% BiI _{3 in} order to obtain radiation absorption equivalent to Se under normal medical radiation imaging conditions).
Is required), and in combination with the conventional organic material, the inorganic material having such a high content cannot be uniformly dispersed, so that the radiation photoconductive property of the obtained radiation conductive material is deteriorated. Will be lost.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides a radiation-conductive material which has an inorganic material uniformly dispersed in an organic material, has good radiation photocon characteristics, and withstands a high electric field, and a method for producing the same. It is intended to provide.

Further, the present invention provides a radiation capable of recording image information formed by irradiating radiation as an electrostatic latent image, has good radiation photocon characteristics, withstands a high electric field, and does not generate charge traps. It is an object to provide a solid-state sensor including a conductive layer.

[0013]

The radiation-conductive material of the present invention is characterized by comprising at least alcohol-soluble nylon and an inorganic material having a radiation-absorbing ability.

Here, the radiation means X-rays, γ-rays and the like. Preferably, the inorganic material is bismuth iodide. The alcohol-soluble nylon is nylon at room temperature which is soluble in an alcohol-based solvent, and is obtained by copolymerizing various dibasic acids or diamines. It means a nylon or the like into which a methyl group has been introduced, and is preferably a composite of nylon-6 and nylon-66. Further, the radiation conductive material of the present invention preferably forms a nanocomposite.

The method for producing a radiation conductive material according to the present invention comprises:
It is characterized in that alcohol-soluble nylon and an inorganic material having a radiation absorbing ability are melted in alcohol, and the alcohol is evaporated to form a high-viscosity composite material. Hereinafter, this manufacturing method is referred to as “liquid layer deposition method”. The high-viscosity composite material manufactured in this manner is used after being formed into a film or the like.

The solid-state sensor of the present invention is characterized by including a radiation conductive layer made of the radiation conductive material of the present invention, which records radiation image information as an electrostatic latent image.

[0017]

According to the radiation conductive material comprising the inorganic / organic composite material of the present invention, alcohol-soluble nylon is used as the organic material, so that the dispersibility of the inorganic material is remarkably improved, and the characteristics of the radiation photo capacitor are improved. be able to.

That is, it has been extremely difficult for conventional radiation-conductive materials composed of inorganic / organic composite materials to uniformly disperse inorganic fine particles in an organic material. Since alcohol-soluble nylon is used as the material, it becomes possible to melt the organic material into alcohol, and thereby the inorganic material can be uniformly dispersed in the organic material.

Further, since the inorganic material can be uniformly dispersed in the radiation conductive material, the characteristics of the inorganic material having excellent radiation absorbing ability, the low dark current, the excellent dielectric properties, and the high quality A radiation-conductive material having the characteristics of an organic material (alcohol-soluble nylon) capable of forming a thin film of the above can be obtained. Therefore, the thin film (radiation conductive layer, etc.) formed of this radiation conductive material does not have a lump of inorganic fine particles, so that the radiation photocon characteristics are improved, and charge traps are less likely to occur. In addition, it is possible to suppress the dark current flowing when no radiation is applied. Further, even when the content of the inorganic material is increased, the inorganic material can be uniformly dispersed in the organic material, so that the radiation photocon characteristics can be improved.

The method for producing a radiation-conductive material according to the present invention is characterized in that an alcohol-soluble nylon and an inorganic material having a radiation-absorbing ability are melted in alcohol, and the alcohol is evaporated from the molten solution to form the alcohol-soluble nylon and the inorganic material. The use of the high-viscosity composite material improves the production handling characteristics and makes the produced radiation-conductive material extremely stable.

[0021]

Embodiments of the present invention will be described below. The radiation conductive material of the present invention is characterized by comprising an alcohol-soluble nylon and an inorganic material having a radiation absorbing ability.

As the inorganic material having a radiation absorbing ability,
VB-VIB, VB-VIIB, IIB-VIB, II
B-VB, IIIB-VB, IIIB-VIB, IB-
VIB, IVB-VIIB inorganic materials such as Bi
₂S_3,Bi₂Se₃, BiI₃, BiBr₃,
CdS, CdSe, CdTe, HgS, Cd₂P₃, I
nAs, InP, In₂S₃, In₂Se₃, Ag
₂S, PbI₂, PbI₄ ^2-Can be used
But especially BiI₃(Bismuth iodide) is preferred.

As described above, the alcohol-soluble nylon may be a copolymerized nylon obtained by copolymerizing various dibasic acids, diamines, or the like, as long as the nylon is solid at room temperature and soluble in an alcohol solvent. Nylon having an N-alkoxymethyl group introduced into a polyamide bond can be used.

The copolymerized nylon is obtained by copolymerizing two or more kinds of diamines and / or two or more kinds of dibasic acids. Examples of the diamine include hexamethylenediamine, heptamethylenediamine, p-di-aminomethylcyclohemisan, bis (p-aminocyclohexyl) methane, m-xylenediamine, and 1,4-bis (3
-Aminopropoxy) cyclohexane, piperazine, isophoronediamine and the like, and dibasic acids such as adipic acid, sebacic acid, azelaic acid, dodecandioic acid, undecanoic acid, dimer acid, phthalic acid, isophthalic acid, terephthalic acid, and 5-sulfoic acid And sodium isophthalate. In the production of nylon, aminocarboxylic acids and the like can also be used, and 11-aminoundecanoic acid, 12-aminododecanoic acid, 4-aminomethylbenzoic acid, 4-aminomethylcyclohexanecarboxylic acid, 7-
Aminocarboxylic acids such as aminoenanoic acid and 9-aminononanoic acid, and lactams such as ε-caprolactam, ω-laurolactam, α-pyrrolidone and α-piperidone can also be used. The alcohol-soluble nylon obtained from such a compound includes nylon-6 / nylon-66, nylon-6 / nylon 6-10, nylon-6 / nylon-66 / nylon 6-10, nylon-6 / nylon-66. / 11-nylon, nylon-
6 / Nylon-66 / Nylon-12, Nylon-6 /
Nylon 6-10 / Nylon 6-11, Nylon-6 /
Nylon 6-10 / Nylon 6-12, Nylon-6 /
11-nylon / isophoronediamine, nylon-6 /
Nylon having a constitution such as nylon-66 / p-di (aminocyclohexyl) methane, and particularly nylon-6
And a composite of nylon-66.

Also, alcohol-soluble nylon can be obtained by introducing an N-alkoxymethyl group obtained by adding formalin and alcohol to a polyamide bond in nylon. Specific examples include those obtained by alkoxymethylation of nylon-6, nylon-66 and the like. The introduction of the N-alkoxymethyl group contributes to lowering the melting point, increasing flexibility, and improving solubility.

Such alcohol-soluble nylons are widely known and are described in Nylon Resin Handbook, Journal.
of the American Chemical Society 71, 651 (1949).

The mixing ratio of alcohol-soluble nylon / inorganic material differs depending on the alcohol-soluble nylon and inorganic material used. For example, when a nylon-6 / nylon-66 composite is used as the alcohol-soluble nylon and bismuth iodide is used as the inorganic material, the mixing ratio (nylon /
BiI ₃ ) is preferably from 50 to 10/50 to 90% by weight, and more preferably from 35 to 15/65 to 85% by weight.

As the alcohol for melting the complex of bismuth iodide, nylon-6 and nylon-66, methanol, ethanol, isopropyl alcohol, n-propyl alcohol, isobutyl alcohol, n-butyl alcohol and the like can be used. , To evaporate the alcohol after melting to make a high-viscosity composite material,
Methanol and ethanol are preferred. When alcohol is used, it is preferable to dehydrate with a molecular sieve or the like. The amount of alcohol used depends on the mixing ratio of the alcohol-soluble nylon and the inorganic material to be melted and the type of alcohol used, so it cannot be said unconditionally, but the alcohol-soluble nylon is dissolved and used in a state where the inorganic material can be sufficiently dispersed. Is preferred.

The radiation conductive material of the present invention can be produced by a liquid layer deposition method. Bismuth iodide as an inorganic material, nylon-6 as an alcohol-soluble nylon
This will be described in detail with reference to FIG. FIG. 1 is a schematic diagram showing a procedure for producing a radiation conductive material. Bismuth iodide and nylon-6 /
Nylon-66 composites are 65-50 / 35-5 respectively
Weigh 10% by weight of beaker containing alcohol 10
In 1, the weighed bismuth iodide and the nylon-6 / nylon-66 composite are put and completely dissolved on a heating device (such as a hot plate) 102. The stirring and dissolving temperature varies depending on the type of alcohol used, but the room temperature (25 ° C)
(Before and after) to 60 ° C. The mixing ratio is, for example, about bismuth iodide: nylon-6 / nylon-66 complex: methanol = 1 g: 1 g: about 100 ml.
The solvent is further evaporated by heating and stirring at 60 ° C. to obtain a highly viscous bismuth iodide / nylon-6 / nylon-66 composite. This highly viscous bismuth iodide / nylon-6 / nylon-66 composite is dropped on a substrate 103 made of aluminum or ITO, and formed into a film with a spatula at room temperature.
Bismuth iodide formed into a film in a petri dish containing methanol /
The substrate with the nylon-6 / nylon-66 composite is allowed to stand and slowly dry to produce a radiation conductive material. When producing the radiation conductive material, other substances (for example, additives) may be appropriately added for the purpose of imparting some function.

Next, a solid-state sensor for recording radiation image information having a radiation-conductive layer containing the radiation-conductive material of the present invention as an electrostatic latent image and a method of reading out the same will be described.

FIG. 2 is a sectional view showing an embodiment of a solid-state sensor having a photoconductive layer containing a radiation conductive material according to the present invention. The solid-state sensor 10 includes a first conductive layer 1 having transparency with respect to a recording radiation L1 described below,
The recording radiation conductive layer 2 which exhibits conductivity by being irradiated with the radiation L1 transmitted through the conductive layer 1, and is substantially insulated from charges (latent image polar charges; for example, negative charges) charged on the conductive layer 1. The charge transport layer 3, which acts as a body and substantially acts as a conductor with respect to charges having a polarity opposite to that of the charges (transport polarity charges; positive charges in the above-described example). It is formed by laminating a reading photoconductive layer 4 exhibiting conductivity by irradiation and a second conductive layer 5 having transparency to electromagnetic waves L2 in this order.

Here, as the conductive layers 1 and 5, for example, a material obtained by uniformly applying a conductive substance on a transparent glass plate (such as a Nesa film) is suitable. As the charge transport layer 3,
The larger the difference between the mobility of the negative charge charged on the conductive layer 1 and the mobility of the positive charge having the opposite polarity, the better (for example, 10
² or more, preferably 10 ³ or higher) poly N- vinylcarbazole (PVK), N, N'-diphenyl -N, N'-bis (3-methylphenyl) - [1,1'-biphenyl] -4,4 '
An organic compound such as diamine (TPD) or discotic liquid crystal, or a polymer (polycarbonate, polystyrene, PUK) dispersion of TPD, and Cl to 10 to 20.
A semiconductor material such as a-Se doped with 0 ppm is suitable. In particular, organic compounds (PVK, TPD, discotic liquid crystal, etc.) are preferable because they have photosensitivity, and the dielectric constant is generally small, so that the capacities of the charge transport layer 3 and the photoconductive layer 4 for reading become small, so Can be increased in signal extraction efficiency.

The reading photoconductive layer 4 includes a-Se, Se-
Te, Se-As-Te, metal-free phthalocyanine, metal phthalocyanine, MgPc (magnesium phtalocyanin)
e), VoPc (phase II of Vanadyl phthalocyanin)
e), a photoconductive substance mainly containing at least one of CuPc (Cupper phtalocyanine) and the like is preferable.

The thickness of the charge transport layer 3 and the photoconductive layer 4 is desirably not more than 1/2 of the thickness of the recording radiation conductive layer 2, and the thinner (for example, 1/10 or less, Furthermore, the response at the time of reading described later is improved.

For the radiation conductive layer 2 for recording, a radiation conductive material comprising the alcohol-soluble nylon of the present invention and an inorganic material having a radiation absorbing ability is used. In order to sufficiently absorb the radiation L1, the recording radiation conductive layer 2 preferably has a thickness of 100 μm to 2000 μm, more preferably 500 μm to 1000 μm.

As reading means for reading an electrostatic latent image from a solid-state sensor in which radiation image information is recorded as an electrostatic latent image,
A method using light to read an electrostatic latent image and a method using a transistor for each pixel can be used.
First, a system using light to read an electrostatic latent image will be briefly described.

FIG. 3 is a schematic configuration diagram of a recording / reading system using the solid-state sensor 10 (integrating an electrostatic latent image recording device and an electrostatic latent image reading device). This recording and reading system includes a solid-state sensor 10, a recording irradiation unit 90, a power supply 5
0, current detection means 70, reading exposure means 92, and connection means S
1 and S2, the electrostatic latent image recording device part is a solid state sensor 1
0, a power supply 50, a recording irradiating unit 90, and a connecting unit S1. The electrostatic latent image reading unit includes the solid state sensor 10, a current detecting unit 70, and a connecting unit S2.

The conductive layer 1 of the solid-state sensor 10 is connected to the negative electrode of the power supply 50 via the connecting means S1, and is also connected to one end of the connecting means S2. One end of the other end of the connection means S2 is connected to the current detection means 70, and the other end of the conductive layer 5 of the solid-state sensor 10, the positive electrode of the power supply 50, and the other end of the connection means S2 are grounded. The current detection means 70 is a detection amplifier composed of an operational amplifier.
A so-called current-to-voltage conversion circuit is composed of a feedback resistor 70a and a feedback resistor 70b.

An object 9 is disposed on the upper surface of the conductive layer 1, and the object 9 has a portion that is transparent to the radiation L1.
There is a cut-off portion (light-shielding portion) 9b having no transmittance 9a.
The recording irradiating means 90 uniformly radiates the radiation L1 to the subject 9, and the reading exposing means 92 scans and exposes a reading light L2 such as an infrared laser beam in a direction of an arrow in FIG. It is desirable that the reading light L2 has a beam shape converged to a small diameter.

Hereinafter, the process of recording an electrostatic latent image in the recording / reading system having the above configuration will be described with reference to a charge model (FIG. 4). In FIG. 4, the connecting means S2 is opened (not connected to the ground or the current detecting means 70), the connecting means S1 is turned on, and the DC voltage Ed from the power source 50 is applied between the conductive layer 1 and the conductive layer 5. Then, a negative charge is applied to the conductive layer 1 and a positive charge is applied to the conductive layer 5 from the power supply 50 (FIG. 4A).
reference). Thereby, a parallel electric field is formed between the conductive layers 1 and 5 in the solid-state sensor 10.

Next, the radiation L1 is uniformly bombarded from the recording irradiation means 90 toward the subject 9. The radiation L1 transmits through the transmitting portion 9a of the subject 9, and further transmits through the conductive layer 1. The radiation conductive layer 2 receives the transmitted radiation L1 and exhibits conductivity. This is understood as acting as a variable resistor that shows a variable resistance value according to the dose of the radiation L1, and the resistance value is that the radiation L1 generates a charge pair of an electron (negative charge) and a hole (positive charge). In this case, the smaller the dose of the radiation L1 transmitted through the subject 9, the larger the resistance value (see FIG. 4B). The negative charge (−) and the positive charge (+) generated by the radiation L1 are represented by − in the drawing.
Or, + is represented by encircling it.

The positive charges generated in the radiation conductive layer 2 move at a high speed in the radiation conductive layer 2 toward the conductive layer 1, and are charged on the conductive layer 1 at the interface between the conductive layer 1 and the radiation conductive layer 2. It disappears by recombination with the negative charge (see FIGS. 4 (C) and 4 (D)). On the other hand, the negative charges generated in the radiation conductive layer 2 move toward the charge transfer layer 3 in the radiation conductive layer 2. Since the charge transfer layer 3 acts as an insulator for charges of the same polarity (negative charges in this example) as the charges charged on the conductive layer 1, the negative charges moving in the radiation conductive layer 2 It stops at the interface between the conductive layer 2 and the charge transfer layer 3 and accumulates at this interface (see FIGS. 4C and 4D). The amount of accumulated charge is determined by the amount of negative charge generated in the radiation conductive layer 2, that is, the amount of radiation L1 transmitted through the subject 9.

On the other hand, since the radiation L1 does not pass through the light-shielding portion 9b of the subject 9, there is no change in the portion below the light-shielding portion 9b of the solid-state sensor 10 (see FIGS. 4B to 4D). In this way, by bombarding the subject 9 with the radiation L1, charges corresponding to the subject image can be accumulated at the interface between the radiation conductive layer 2 and the charge transfer layer 3. still,
The subject image due to the accumulated charges is called an electrostatic latent image.

Next, the process of reading an electrostatic latent image will be described with reference to a charge model (FIG. 5). The connection means S1 is opened to stop the power supply, and S2 is once connected to the ground side, and the conductive layers 1 and 5 of the solid-state sensor 10 on which the electrostatic latent image is recorded are charged to the same potential to rearrange the charges. (Figure 5 (A)
), And the connecting means S2 is connected to the current detecting means 70 side.

When the reading light L2 is scanned and exposed to the conductive layer 5 side of the solid-state sensor 10 by the reading exposure means 92, the reading light L2 is transmitted through the conductive layer 5, and the transmitted reading light L2 is irradiated with the photoconductive layer. No. 4 becomes conductive according to the scanning exposure.
This depends on the fact that the radiation conductive layer 2 receives the irradiation of the reading light L2 and generates a positive / negative charge pair, similarly to the case where the radiation conductive layer 2 exhibits conductivity by generating a positive / negative charge pair. (See FIG. 5B). Note that, similarly to the recording process, the negative charge (-) and the positive charge (+) generated by the reading light L2 are represented by enclosing-or + in the drawing.

Since the charge transport layer 3 acts as a conductor for positive charges, the positive charges generated in the photoconductive layer 4 rapidly flow through the charge transport layer 3 so as to be attracted to the accumulated charges. It moves, and the accumulated charges and charge recombination disappear at the interface between the radiation conductive layer 2 and the charge transport layer 3 (see FIG. 5C). On the other hand, the negative charges generated in the photoconductive layer 4 recombine with the positive charges in the conductive layer 5 and disappear (see FIG. 5C). The photoconductive layer 4 is scan-exposed with a sufficient amount of light by the reading light L2, and all the accumulated charges accumulated at the interface between the radiation conductive layer 2 and the charge transport layer 3, ie, the electrostatic latent image, are recombined. Disappeared by Thus, the disappearance of the charge accumulated in the solid state sensor 10 means that the solid state sensor 10
This means that the current I due to the movement of the electric charge has flowed through 10, and this state is an equivalent circuit as shown in FIG. 5D in which the solid-state sensor 10 is represented by a current source whose current amount depends on the accumulated charge amount. It can be shown with.

As described above, by detecting the current flowing from the electrostatic recording medium 10 while scanning and exposing the reading light L2, the accumulated charge amount of each portion (corresponding to a pixel) that has been scanned and exposed can be sequentially read. The electrostatic latent image can be read.

The radiation conductive material of the present invention is of a type using a transistor (TF) for reading out electric charges.
It can also be used for a solid-state sensor of the (T type). FIG. 6 is a cross-sectional view of a solid-state sensor using a transistor for reading out such charges, and FIG. 7 is a schematic configuration diagram of a reading device of the solid-state sensor. The solid-state sensor includes a single dielectric support 61, a plurality of array-like transistors 62 provided on the support 61, and a plurality of array-like charge storage capacitors similarly provided on the support 61. 63, a radiation conductive layer 64 provided further on the transistor 62 and the capacitor 63, a barrier dielectric layer 65 provided on the radiation conductive layer 64, and an upper electrode further provided thereon
66, and each capacitor 63 is a transistor
It has a conductive inner microplate 67 connected to 62, and further has a charge barrier layer 68 on the surface of each inner microplate 67,
The radiation conductive material of the present invention can also be used for the radiation conductive layer 64 of the solid-state sensor 60.

As shown in FIG. 7, the reading of the solid-state sensor 60 is performed by sequentially taking out the electric charge flowing out of the solid-state sensor 60 by the multiplexer 76 and sequentially detecting the electric charge by the detector 75, thereby sequentially reading the accumulated electric charge. This allows an electrostatic latent image to be read. The details of this reading method are described in SPIE Vol. 2432/237 and the like.

An example of the production of a film made of an X-ray conductive material will be described below as an example of producing the radiation conductive material of the present invention.

[0051]

EXAMPLES Example 1 Bismuth iodide and nylon-6 were added to 100 ml of methanol dehydrated by molecular sieve.
/ Nylon CM4000 which is a nylon-66 composite
(Company name: Toray Industries, Inc.) was added in an amount of 1 g each, and completely dissolved at a stirring and dissolution temperature of 60 ° C. After dissolution, methanol was evaporated by heating and stirring at 60 ° C. to obtain highly viscous bismuth iodide / nylon CM4000. This highly viscous bismuth iodide / nylon CM4000 was dropped onto an aluminum substrate (substrate temperature 0 to 50 ° C.), and a film was formed with a spatula at room temperature. After the film was formed, the substrate with the formed bismuth iodide / nylon CM4000 was allowed to stand still in a petri dish containing methanol, and gradually dried to obtain a film made of an X-ray conductive material. The obtained film thickness was 200 μm.

(Comparative Example 1) Bismuth iodide and nylon
Nylon CM400, which is a 6 / nylon-66 composite, was weighed at a ratio of 50/50% by weight. Nylon CM4000 is melted on an aluminum substrate heated to 180 to 210 ° C., and on the melted nylon CM4000,
The weighed bismuth iodide was added, stirred for several minutes with a spatula, formed into a film with a spatula, and allowed to cool to room temperature to obtain a film made of an X-ray conductive material. The obtained film thickness was 200 μm.

Comparative Example 2 A film made of an X-ray conductive material was obtained in the same manner as in Comparative Example 1 except that 11-nylon was used instead of nylon CM4000. The obtained film thickness was 200 μm.

(Evaluation) X obtained in Examples and Comparative Examples
The density of bismuth iodide of the line conductive material and the X-ray photo-con signal were measured. The X-ray photo-con signal was obtained by depositing gold on the obtained X-ray conductive material by 5 mm × 5 mm × 600 mm.
Sputter, D1 photocon evaluation device (X-ray: 8
0 kV-10 to 100 mR, detection: picoammeter) and D6 photo-con evaluation device (X-ray: 80, 12)
0 kV-20 mR, detection: digital oscilloscope), and measured as an X-ray photo-con current per unit volume. The dark current was measured at an applied voltage that indicated the maximum X-ray photo-con current. Table 1 shows the results.

[0055]

[Table 1] As is clear from Table 1, nylon-6 / nylon-6
The density of bismuth iodide, which is an inorganic material, is lower when nylon CM4000, a 6-complex, is used (Example 1) than when 11-nylon, which is insoluble in alcohol, is used (Comparative Example 2). High, X-ray photocon signal is 4.4
Times (2.8 times per unit volume). In addition, the dark current has been significantly improved. When comparing the production methods of the X-ray conductive material, the liquid layer deposition method (Example 1) is 1.3 times as large as the melt deposition method (Comparative Example 1). , Good production handling characteristics, and high production stability.

As is clear from the above results, the thin film formed of the radiation conductive material comprising the alcohol-soluble nylon of the present invention and an inorganic material having a radiation absorbing ability was formed by the conventional radiation conductive material. Compared to the thin film, the inorganic material is remarkably evenly dispersed in the organic material, so there is no such thing as a lump of inorganic fine particles. Further, it has become possible to suppress the dark current flowing when no radiation is applied.

[Brief description of the drawings]

FIG. 1 is a schematic view of a procedure for producing a radiation conductive material of the present invention.

FIG. 2 is a cross-sectional view showing one embodiment of a solid-state sensor having a radiation conductive layer containing a radiation conductive material of the present invention.

FIG. 3 is a schematic configuration diagram of a recording / reading system using a solid-state sensor;

FIG. 4 is a diagram showing a process of recording an electrostatic latent image in a recording and reading system by using a charge model;

FIG. 5 is a diagram showing a process of reading an electrostatic latent image in a recording and reading system by using a charge model;

FIG. 6 is a sectional view showing a different embodiment of the solid-state sensor.

FIG. 7 is a schematic configuration diagram of a recording / reading system using different solid-state sensors.

FIG. 8 is a schematic view of a conventional procedure for producing a radiation conductive material.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 conductive layer 2 radiation conductive layer for recording 3 charge transport layer 4 photoconductive layer for recording 5 conductive layer 10 solid-state sensor 70 current detecting means

Claims (6)

[Claims] 1. A radiation-conductive material comprising at least alcohol-soluble nylon and an inorganic material having a radiation absorbing ability. 2. The radiation conductive material according to claim 1, wherein said inorganic material is bismuth iodide. 3. The radiation conductive material according to claim 1, wherein the alcohol-soluble nylon is a composite of nylon-6 and nylon-66. 4. The radiation conductive material according to claim 1, wherein the radiation conductive material forms a nanocomposite. 5. A radiation-conductive material characterized by melting an alcohol-soluble nylon and an inorganic material having a radiation absorbing ability into an alcohol, and evaporating the alcohol to form a high-viscosity composite material of the alcohol-soluble nylon and the inorganic material. Material manufacturing method. 6. A solid-state sensor comprising a radiation-conductive layer made of the radiation-conductive material according to claim 1, which records radiation image information as an electrostatic latent image.