JPS61209263A - Material having impermeability to x-ray or neutron ray - Google Patents

Abstract

PURPOSE:A material having extremely improved transparency, X-ray and neu tron ray shielding ability while keeping improved mechanical strength of resin of it own, obtained by blending a polyamide resin with a compound containing an element of group IIb of the periodic table. CONSTITUTION:100pts.wt. polyamide resin is blended with 5-100pts.wt. com pound comprising an element of group IIb of the periodic table. A polyamide having >=10,000 number-average molecular weight is used as the polyamide. A zinc halide, or a cadmium halide is preferably used as the compound.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a material that is transparent and has excellent mechanical properties, and has the ability to shield X-rays and neutron rays.

[Conventional technology and problems]

BACKGROUND ART Conventionally, as a material that is transparent and has the ability to shield X-rays or neutron rays, a mixture of glass and heavy metals such as lead and cadmium has often been used. However, since it is made of glass, there were problems with mechanical strength, workability, etc. In order to improve these properties, attempts have been made to incorporate various X-ray or neutron radiation-opaque materials into transparent plastics (for example, Japanese Patent Application Laid-Open No. 50-83437, Japanese Patent Application Laid-Open No. 54-95695). Publications, etc.).

However, when kneaded by the usual melt-kneading method, the amount added must be kept to about 5 parts by weight at most in order to maintain transparency, and the resulting product exhibits almost no X-ray or neutron ray shielding ability.

Therefore, it was necessary to adopt a cast polymerization method in which a 7-mer and an impermeable material are mixed together with a polymerization initiator, and the mixture is placed in a mold and polymerized, resulting in poor workability.

[Means for solving problems]

The object of the present invention is to have X-ray or neutron beam shielding ability;
Another object of the present invention is to provide a material made of a polyamide resin composition that has excellent transparency and mechanical strength.

The inventor of the present invention has conducted intensive studies to improve the transparency and X-ray or neutron beam shielding ability while maintaining the excellent mechanical strength of polyamide resin. The present invention was achieved based on the discovery that transparency and X-ray or neutron beam shielding ability are significantly improved when a compound consisting of the elements is blended.

That is, the present invention provides a transparent X-ray- or neutron-ray-free material, which is made by mixing 5 parts by weight or more and 100 parts by weight or less of a compound consisting of an element of Group IIb of the periodic table of elements with 100 parts by weight of a polyamide resin. This relates to transparent materials.

The polyamide resin referred to in the present invention includes ε-caprolactam, 6-aminocaproic acid, ω-enantholactam, 7-
Polymers from aminohebutanoic acid, 9-aminononanoic acid, 11-aminoundecanoic acid, ω-lauryllactam, 12-aminododecanoic acid, α-pyrrolidone, α-piperidone; tetramethylenediamine, hexamethylenediamine, nonamethylenediamine , undecamethylenediamine,
Dodecamethylene diamine, metaxylylene diamine, 1
．． A polymer obtained by polycondensing a diamine such as 4-bis(aminomethyl)cyclohexane with a dicarboxylic acid such as terephthalic acid, isophthalic acid, adipic acid, sebacic acid, dodecanoic acid, or cyclohexanedicarboxylic acid; Copolymers; mixtures of these polymers, and the like. Examples of copolymers include elastomers such as polyetheresteramide, which is a copolymer with a soft segment such as polytetrahydrofuran.

It is desirable that the number average molecular weight of the polyamide is 10,000 or more.

In the present invention, all compounds comprising elements of Group IIb of the periodic table of elements have X-ray or neutron beam shielding ability, but zinc halides and cadmium halides are particularly effective.

In the present invention, the addition amount of the compound consisting of an element of group IIb of the periodic table of elements is 5 parts by weight or more and 100 parts by weight or less per 100 parts by weight of the polyamide resin, and less than 5 parts by weight is sufficient for If the amount exceeds 100 parts by weight, the added compound cannot be uniformly dispersed in the polyamide, resulting in a significant decrease in transparency.

The method of adding a compound consisting of an element of Group IIb of the Periodic Table of Elements to the polyamide resin in the present invention is not particularly limited, and includes a method of immersing a polyamide pellet or powder in a solution in which the compound is dissolved, a method of immersing a polyamide pellet or a powder in a solution containing the compound, and a method of adding a compound and a polyamide pellet to the polyamide resin. Alternatively, any method can be used, such as mixing the powder and then melt-kneading it in an extruder, or adding it at the stage of polyamide polymerization.

The transparent X-ray or neutron ray-opaque material of the present invention is put into practical use after being molded into an arbitrary shape by a method such as press molding, extrusion molding, or injection molding.

Furthermore, the transparent X-ray or neutron ray-opaque material of the present invention may be blended with commonly used additives for resins, such as oxidation stabilizers, flame retardants, plasticizers, ultraviolet stabilizers, heat stabilizers, etc. It's okay.

The thus obtained transparent X-ray or neutron radiation-opaque material of the present invention has extremely good X-ray or neutron radiation shielding ability, good transparency and mechanical properties, and extremely good processability. have.

〔Example〕

EXAMPLES Hereinafter, the present invention will be described in detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.

Example 1 Nylon 12 (Diamid T manufactured by Daicel Huls ■,
t901) 5 parts by weight of cadmium iodide were added to 100 parts by weight of pellets, mixed using a Henschel mixer, melt-kneaded using an extruder, and then pelletized using a pelletizer. Using this pellet, a sheet having a thickness of 1llII11 was produced by press molding, and this sheet showed good transparency. Attach this sheet to a normal X-ray diffraction device (Geigerflex manufactured by Rigaku Denki),
CuKα radiation (
When a beam diameter of 1 mm) was irradiated and the transmitted X-rays were measured with a scintillation counter, a count value about twice the background was obtained.

Comparative Example 1 A press sheet with a thickness of 11 was prepared in the same manner as in Example 1 except that cadmium iodide was not added, and the amount of X-ray transmission was measured. The scintillation counter has malfunctioned.

Example 2 A press sheet was produced in exactly the same manner as in Example 1 except that the amount of cadmium iodide added was 50 parts by weight, and a sheet with good transparency was obtained. When the amount of X-rays transmitted through this material was measured, a count value equal to that of the background was obtained, and it was revealed that substantially no X-rays were transmitted.

Example 3 A press sheet was produced in exactly the same manner as in Example 1 except that the amount of cadmium iodide added was 95 parts by weight, and a sheet with good transparency was obtained. When we measured the amount of X-ray transmission of this material, we obtained only the same count value as the background, and in fact
It became clear that a was not transmitted.

Comparative Example 2 In Example 1, the amount of cadmium iodide added was 120
When a press sheet was prepared in exactly the same manner as in Example 1 except for the parts by weight, the added cadmium iodide was dispersed in the nylon, resulting in a significant decrease in transparency.

Example 4 In Example 2, nylon 6 was used instead of nylon 12.
A press sheet was prepared in exactly the same manner as in Example 2 except that CM-1021T (manufactured by Toshi) was used, and a sheet with good transparency was obtained. When the amount of X-rays transmitted through this material was measured, only the same count value as the bank ground was obtained, and it was revealed that substantially no XNa was transmitted.

Example 5 In Example 2, nylon 6 was used instead of nylon 12.
12 (Diamid 01800 manufactured by Daicel Huls ■)
) was produced in exactly the same manner as in Example 2, except that a sheet with good transparency was obtained. When we measured the amount of X-ray transmission through this material, we obtained only the same count value as the background, and in fact
It became clear that the line was not transparent.

Example 6 A press sheet was produced in exactly the same manner as in Example 2 except that cadmium chloride was used instead of cadmium iodide, and it had good transparency. When the amount of X-rays transmitted through this sheet was measured, only the same count value as the background was obtained, and it became clear that substantially no X-rays were transmitted.

Example 7 A press sheet was prepared in the same manner as in Example 2 except that zinc bromide was used instead of cadmium iodide, and the sheet had good transparency. When the amount of X-ray transmission was measured, only the same count value as the background was obtained, making it clear that virtually no X-rays were transmitted.

Claims (1)

[Claims] To 100 parts by weight of polyamide resin, the periodic table of elements IIb
A transparent material that is opaque to X-rays or neutrons, and is made of a compound containing an element of the group 5 to 100 parts by weight.