Abstract:
A porous stamp material allows only resin in a region thereof irradiated with a laser beam during laser engraving in a production process of an ink stamp to be burnt and vaporized while preventing melting in any other unwanted region. The porous material for ink stamps comprises: at least one thermoplastic resin selected from the group consisting of low-density polyethylene, linear low-density polyethylene, high-density polyethylene, ethylene-alpha-olefin copolymer, ethylene-vinyl acetate copolymer, and ethylene-acrylic copolymer; at least one thermoplastic elastomer selected from a plurality of different hydrogenated styrene based thermoplastic elastomers; and at least one filler selected from a plurality of different inorganic compounds, wherein the thermoplastic resin and/or the thermoplastic elastomer are cross-linked, and formed in a continuous pore structure.
Abstract:
A method of producing a porous molded part includes a mixing process for mixing a granular porous organizer composed of a water-soluble compound, a porous forming assistant agent composed of a polyhydric alcohol, and a cross-linking agent composed of an organic peroxide with a thermoplastic resin composition having a glass transition temperature below 0° C. to obtain a molding material; a cross-linking and forming process for placing the molding material in a molding die and performing a heat press molding thereby progressing coincidentally a cross-linking reaction and a shape forming of a seal face to obtain a molded material; an extracting process for extracting the granular porous organizer from the molded material obtained in the cross-linking and forming process to obtain a porous molded part; and a drying process for drying the porous molded part obtained in the extracting process.