초록 ▼

The present invention provides: a water-absorbent resin powder, which includes no fine metallic foreign substance, and in which the deterioration is suppressed; its production process; and uses. The present invention production process for a water-absorbent resin powder comprises the steps of: polym

The present invention provides: a water-absorbent resin powder, which includes no fine metallic foreign substance, and in which the deterioration is suppressed; its production process; and uses. The present invention production process for a water-absorbent resin powder comprises the steps of: polymerizing an unsaturated monomer; and drying the resultant crosslinked hydrogel polymer, wherein the water-absorbent resin powder has a crosslinked structure and a mass-average particle diameter of 300 to 600 μm wherein the ratio of fine particles having particle diameters of not larger than 150 μm is less than 10 mass % of the water-absorbent resin powder, with the production process being characterized by further comprising a magnetic-flux irradiation step of passing a magnetic field having a magnetic flux density of not less than 0.05 Wb/m2through the water-absorbent resin powder after the drying step in the production process.

대표청구항 ▼

The present invention provides: a water-absorbent resin powder, which includes no fine metallic foreign substance, and in which the deterioration is suppressed; its production process; and uses. The present invention production process for a water-absorbent resin powder comprises the steps of: polym

The present invention provides: a water-absorbent resin powder, which includes no fine metallic foreign substance, and in which the deterioration is suppressed; its production process; and uses. The present invention production process for a water-absorbent resin powder comprises the steps of: polymerizing an unsaturated monomer; and drying the resultant crosslinked hydrogel polymer, wherein the water-absorbent resin powder has a crosslinked structure and a mass-average particle diameter of 300 to 600 μm wherein the ratio of fine particles having particle diameters of not larger than 150 μm is less than 10 mass % of the water-absorbent resin powder, with the production process being characterized by further comprising a magnetic-flux irradiation step of passing a magnetic field having a magnetic flux density of not less than 0.05 Wb/m2through the water-absorbent resin powder after the drying step in the production process. g (1) comprises a body (2) made from said metallic material, which body has a hollow structure, and at least one sealing member (2) made from the metallic material and/or non-radioactive and non-activatable metallic material. 9. A seed according to claim 1, wherein the body (2) is a hollow cylinder and wherein the sealing member (3) is either two endcaps or a second hollow cylinder disposed within the body which internally seal (s) the body (2). 10. A radioactive or activatable seed comprising: a closed and self-supported casing having a central cavity, the casing comprising: (a) a radioactive or activatable metallic material selected from the group consisting of a metal, an alloy and metal composite or mixtures thereof, and (b) optionally a non-radioactive and non-activatable metallic material; wherein the radioactive or activatable metallic material comprises a radioactive nuclide selected from the group consisting of Pd-103, Tm-170, Sr-90, Y-90, Yb-169, P-32, Ge-71, Se-75, Cl-36, Ta-182, Tl-204, Re-188, W-188, Ce-144, Pr-144, Sn-123, Ru-106, Rh-106 and mixtures thereof, and/or an activatable precursor nuclide thereof selected from the group consisting of Pd-102, Rh-103, Tm-169, Y-89, Yb-168, P-31, Ge-70, Se-74, Cl-35, Ta-181, Tl-203, W-186, Sn-122 and mixtures thereof, excluding metallic Pd with natural abundance of Pd-102, wherein the casing consists of an alloy of the radioactive nuclide and/or activatable precursor nuclide with V, Ti, Al, Ni, Nb, Fe, stainless steel and mixtures thereof. 11. A radioactive or activatable seed comprising: a closed and self-supported casing having a central cavity, the casing comprising: (a) a radioactive or activatable metallic material selected from the group consisting of a metal, an alloy and metal composite or mixtures thereof, and (b) optionally a non-radioactive and non-activatable metallic material; wherein the radioactive or activatable metallic material comprises a radioactive nuclide selected from the group consisting of Pd-103, Tm-170, Sr-90, Y-90, Yb-169, P-32, Ge-71, Se-75, Cl-36, Ta-182, Tl-204, Re-188, W-188, Ce-144, Pr-144, Sn-123, Ru-106, Rh-106 and mixtures thereof, and/or an activatable precursor nuclide thereof selected from the group consisting of Pd-102, Rh-103, Tm-169, Y-89, Yb-168, P-31, Ge-70, Se-74, Cl-35, Ta-181, Tl-203, W-186, Sn-122 and mixtures thereof, excluding metallic Pd with natural abundance of Pd-102, wherein the casing consists of an alloy of the radioactive nuclide and/or activatable precursor nuclide with V, Ti, Al, Ni, Nb, Fe, stainless steel and mixtures thereof, wherein the radioactive nuclide and/or activatable precursor nuclide is in the form of a material comprising the desired nuclide in natural abundance, a material enriched in the nuclide hi her than natural abundance or a material depleted of isotopes of the precursor element giving rise to undesirable radiation emitting isotopes during the activation treatment, and mixtures thereof. 12. A seed according to claim 11, wherein a material enriched in the activatable precursor nuclide is used and the degree of enrichment is at least 5% and up to 100%. 13. A seed according to claim 12, wherein the degree of enrichment is at least 20% and up to 100%. 14. A seed according to claim 12, wherein the degree of enrichment is from 50% to 90%. 15. A radioactive or activatable seed comprising: a closed and self-supported casing having a central cavity, the casing comprising: (a) a radioactive or activatable metallic material selected from the group consisting of a metal, an alloy and metal composite or mixtures thereof, (b) optionally a non-radioactive and non-activatable metallic material; wherein the radioactive or activatable metallic material comprises a radioactive nuclide selected from the group consisting of Pd-103, Tm-170, Sr-90, Y-90, Yb-169, P-32, Ge-71, Se-75, Cl-36, Ta-182, Tl-204, Re-188, W-188, Ce-144, Pr-144, Sn-123, Ru-106, Rh-106 and mixtures thereof, and/or an activatable precursor nucli