Copper ion-producing composition

A granular composition comprising a copper ion-producing composition and poorly water-soluble material, said copper ion-producing composition being obtained by mixing 0.3 to 10 weight parts surfactant with 100 weight parts metallic copper powder, treating the surface of the metallic copper powder with the surfactant, and mixing 10 to 500 weight parts acidic compound with 100 weight parts metallic copper powder,

• wherein the surface of a solid material comprising said poorly water-soluble material is coated with the copper ion-producing composition,
• wherein said granular composition further has the properties described in (a), (b), (c) and (d) below:
• (a) The metallic copper powder is a finely divided powder with an average particle size of not more than 40 microns and 0.1 to 5 weight % metallic copper powder is contained in the granular composition;
• (b) The surfactant is at least one selected from the group consisting of an anionic surfactant, cationic surfactant, amphoteric surfactant and nonionic surfactant, and those with an HLB of 10 to 20;
• (c) The acidic compound is at least one selected from the group consisting of ammonium sulfate, benzoic acid, salicylic acid, tartaric acid, 2-acrylamido-2-methylpropanesulfonic acid, sodium acid metaphosphate, ferric sulfate, and methanesulfonic acid;
• (d) A substrate of the poorly water-soluble material is at least one selected from the group consisting ionomers, acrylonitrile-butadiene-styrene resins (ABS), ethylene-vinyl acetate copolymer resins (EVA), low-melting ethylene-tetrafluoroethylene copolymers (LMETPE), peroxyacyl nitrate (PAN), polyacetal resins (POM), polyamides (PA), polyethylenes (PE), polycarbonates, polyvinyl alcohols (PVA), polyvinyl butyral (PVB), PVF, elastomers, butadienes, polypropylenes (PP), polymethylpentenes (TPX), polyurethanes, maleic acid resins, epoxies, polyester resins, natural high molecular weight acetate plastics, polyterpenes, shellac, dammar gum, rosin, low molecular weight polyethylenes, polypropylene resins, coumarone plastics, petroleum resins, and DCPD resins, and the poorly water-soluble material is water-insoluble material with a softening point of not less than 70° C.