Abstract: An electroless gold plating solution comprising an aqueous solution containing as ingredients (a) chloroauric (III) acid or a salt thereof or a sulfite or thiosulfate gold (I) complex salt as a gold source, (b) an alkali metal or ammonium sulfite or thiosulfate, (c) ascorbic acid or a salt thereof and (d) a pH buffer, characterized in that (e) a compound selected from 2-mercaptobenzothiazole, 6-ethoxy-2-mercaptobenzothiazole, 2-mercaptobenzimidazole, 2-mercaptobenzoxazole and salts thereof, and optionally (f) an alkylamine compound are further incorporated. The solution prevents the bath made up thereof from forming any precipitate during the storage and usage of the bath and the bath can be stably used for long periods of time. Furthermore, the bath gives a significantly high plating rate, which does not decrease even at high bath loads. Thus the bath renders it possible to plate a number of substrate items within a short period of time and also to perform thick plating within a short period of time.

Abstract: Zeolite particles retaining silver ions having bacteriostatic properties on their ion-exchangeable sites in an amount up to 41% of the zeolite's exchange capacity are described.

Abstract: Zeolite particles retaining at least one metal ion having bacteriostatic properties on their ion-exchangeable sites in an amount up to 41% of the zeolite's ion exchange capacity are described.

Abstract: A polymer article containing zeolite particles on which metal ion having a bactericidal property, e.g. Ag, Cu or Zn, is provided by an ion exchange reaction shows an excellent bactericidal effect and durability of the effect, but no deterioration of physical properties of the polymer.The polymer article is produced by admixing zeolite particles previously provided with the metal ion with a polymer or by moulding a zeolite-containing polymer into an article and then treating the article with a metal ion solution.

Abstract: Specific zeolite particles retaining therein a metal ion having a bactericidal activity are packed and retained in a mixed fiber assembly composed of low-melting thermoplastic synthetic fibers and ordinary fibers. The zeolite particles are retained by welding of the low-temperature thermoplastic synthetic fibers but in a state of allowing the contact thereof with an external fluid. The particle-packed fiber article has an excellent and durable antibacterial activity and can be used in various fields.