Some Microbial-Resistant Compounds of Zirconium and Their Effect on Cotton

New antimicrobial agents suitable for use on cotton fabrics have been made by reacting certain zirconium compounds with inorganic and organometallic compounds. Several zirconium compounds have been examined for this purpose, but most of the research has been done with zirconyl acetate and zirconyl ammonium carbonate. Both of these water-soluble zirconium compounds have been found to solubilize a number of antimicrobial agents. Although several agents have been studied, most emphasis has been placed upon inexpensive copper compounds and a lesser amount on phenylmercury salts. The antimicrobial agents are made water-soluble by reacting them with one of the zirconium compounds. When the aqueous solutions are heated to dryness the, active ions of the antimicrobial agents form insoluble products with zirconium. If zirconium acetate is used as the solubilizing agent, basic zirconyl acetate is a component of the insoluble deposit. However, when zirconyl ammonium carbonate is the solubilizing agent, zirconia is found combined with the antimicrobial agent. Structural formulae are given to illustrate some of the water-soluble products and also the insoluble products that are thought to result from heating the soluble materials. The results of water leaching and substantivity are given. Cotton fabrics are finished with the antimicrobial agents by padding them through stable solutions of the solubilized compounds, then drying at elevated temperatures. Treated fabrics have a high degree of resistance to degradation by micro-organisms when tested by soil burial and outdoor exposure methods. For example, 10-oz duck treated with copper borate solubilized with zirconyl ammonium carbonate to deposit copper bis(borato zirconic acid) retained 100% strength after five weeks in a rot bed and remained free of mildew and algae growth for many months on outdoor exposure. There appears to be a number of advantages of the new zirconium compounds over antimicrobial agents in current commercial use. The new agents have the advantage of: (i) good resistance to micro-organisms; (ii) good durability; (iii) lower cost than copper-8-quinolinolate; (iv) no odor; and (v) some resistance to action degradation.