Anti-Microbial Fibres and Their Production

• US 20070243380A1
• Filed: 08/04/2005
• Published: 10/18/2007
• Est. Priority Date: 08/05/2004
• Status: Abandoned Application

• Current Assignee: Lenzing AG (B & C Privatstiftung)
• Original Assignee: Lenzing AG (B & C Privatstiftung)
• Inventors: Hayhurst, Malcolm, Vegad, Hiran
• Application Number:
  US11/573,129
• Publication Number:
  US 20070243380A1
• Time in Patent Office: Days
• US Class Current: 428/379
• CPC Class Codes: D01F 1/103 Agents inhibiting growth of microorganisms
• CPC Class Codes: D01F 2/00 Monocomponent artificial filaments or the like of cellulose or cellulose derivatives; Manufacture thereof
• CPC Class Codes: Y10T 428/294 including metal or compound thereof [excluding glass, ceramic and asbestos]

Abstract

Anti-microbial lyocell fibres incorporate an anti-microbial composition which comprises a silver compound deposited on a support material in the form of porous particles having an extended surface area and comprising an oxidic material which is essentially insoluble in water and incapable of forming hydrates. A preferred composition is silver chloride on titanium dioxide particles. The anti-microbial effect is durable to processing and the fibres are not adversely discoloured. Low concentrations of the anti-microbial composition of below 0.1 percent by weight on weight of cellulose may be used. In the process of making the fibres, the anti-microbial composition preferably is added to the pasty pre-mix of the spinning solution.

Claims

1. Anti-microbial lyocell fibres incorporating anti-microbial composition which includes a silver compound held on a support material, characterized in that the anti-microbial composition comprises a silver compound deposited on a support material in the form of porous particles having an extended surface area and comprising an oxidic material which is essentially insoluble in water and incapable of forming hydrates.

2. Anti-microbial lyocell fibres according to claim 1, characterized in that the oxidic support material is selected from oxides of titanium, magnesium, aluminum, silicon, cerium, zirconium, hafnium, niobium and tantalum, calcium hydroxyapatite and barium sulphate.

3. Anti-microbial lyocell fibres according to claim 1, characterized in that the oxidic support material is titanium dioxide in one or more of the crystalline forms anatase, rutile and brookite.

19. Anti-microbial lyocell fibres according to claim 1, wherein the porous particles comprising the oxidic support material have an average particle diameter below 25 microns.

20. Anti-microbial lyocell fibres according to claim 19, wherein the porous particles have a surface area in the range 1 to 240 square metres per gram.

21. Anti-microbial lyocell fibres according to claim 1, wherein the porous particles have a surface area in the range 1 to 240 square metres per gram.

22. Anti-microbial lyocell fibres according to claim 1, wherein the silver compound has a low solubility in water and has silver present as an ionic species.

23. Anti-microbial lyocell fibres according to claim 22, wherein the silver compound is at a level of concentration of 1 to 75 percent by weight of the oxidic support material.

24. Anti-microbial lyocell fibres according to claim 23, wherein the silver compound comprises silver chloride.

25. Anti-microbial lyocell fibres according to claim 1, wherein the silver compound is at a level of concentration of 1 to 75 percent by weight of the oxidic support material.

26. Anti-microbial lyocell fibres according to claim 1, wherein the silver compound comprises silver chloride.

27. Anti-microbial lyocell fibres according to claim 3, wherein the silver compound comprises silver chloride.

28. Anti-microbial lyocell fibres according to claim 1, wherein the anti-microbial composition is in a concentration in the fibres of below 1 percent by weight owc.

29. Anti-microbial lyocell fibres according to claim 28, wherein the anti-microbial composition is in a concentration in the fibres of below 0.1 percent by weight owc.

4-10. -10. (canceled)

11. A process for making anti-microbial lyocell fibres by dissolving cellulose in a solvent of aqueous tertiary amine N-oxide to form a spinning solution, extruding the spinning solution through a spinning jet into a coagulation bath to produce lyocell fibres, and incorporating an anti-microbial composition into the fibres, characterized in that the anti-microbial composition is added to the spinning solution or to a precursor or ingredient of that solution and comprises a silver compound deposited on a support material in the form of porous particles having an extended surface area and comprising an oxidic material which is essentially insoluble in water and incapable of forming hydrates.

12. A process according to claim 11, in which the spinning solution is made by forming a precursor comprising a pre-mix of cellulose pulp and aqueous amine oxide solvent having excess water over the optimum required for solution to take place, characterized in that the anti-microbial composition is added to the pre-mix, and water is then evaporated from the pre-mix to form the spinning solution having the anti-microbial agent dispersed therein.

15. A process according to claim 12, wherein the anti-microbial composition is added in the form of a dispersion in a liquid.

16. A process according to claim 15, wherein the lyocell fibres are subjected to one or more treatments comprising scouring or washing to substantially remove any residual colouration formed during the fibre-making process.

17. A process according to claim 11, wherein the anti-microbial composition is added in the form of a dispersion in a liquid.

18. A process according to claim 11, wherein the lyocell fibres are subjected to one or more treatments comprising scouring or washing to substantially remove any residual colouration formed during the fibre-making process.

13-14. -14. (canceled)