Antimicrobial nonwoven polyamides with zinc content
The present disclosure relates to a nonwoven polyamide structure having antimicrobial properties comprising: nonwoven polyamide fibers comprising less than 4000 ppm zinc dispersed within the nonwoven polyamide fibers; and less than 2000 ppm phosphorus. The fibers have an average fiber diameter of less than 25 microns; and the polyamide structure demonstrates a Staphylococcus Aureus reduction of at least 90%, as measured by ISO 20743-13.
1. A nonwoven polyamide structure having antimicrobial properties comprising:
nonwoven polyamide fibers comprising a polyamide composition comprising:
less than 4000 ppm zinc dispersed within the nonwoven polyamide fibers; and
less than 2000 ppm phosphorus,
wherein the fibers have an average fiber diameter of less than 20 microns;
wherein the zinc is provided via a zinc compound and the phosphorus is provided via a phosphorus compound different from the zinc compound; and
wherein the polyamide structure demonstrates a Staphylococcus Aureus reduction of at least 90%, as measured by ISO 20743-13.
2. The nonwoven polyamide structure of claim 1 , wherein the weight ratio of the zinc to the phosphorus is at least 1.3:1; or less than 0.64:1.
3. The nonwoven polyamide structure of claim 1 , wherein the relative viscosity of the polyamide composition is less than 100.
4. The nonwoven polyamide structure of claim 1 , wherein the polyamide composition comprises less than 3100 ppm of zinc, wherein the polyamide composition comprises a delusterant including at least a portion of the phosphorus, and wherein the polyamide demonstrates a Staphylococcus Aureus reduction of at least 90%, as measured by ISO 20743-13.
5. The nonwoven polyamide structure of claim 1 , wherein no more than 20% of the fibers have a diameter of greater than 700 nanometers.
6. The nonwoven polyamide structure of claim 1 , wherein the polyamide comprises nylon 66 or nylon 6/66.
7. Antimicrobial fibers having antimicrobial properties comprising:
a polymer;
less than 4000 ppm zinc dispersed within the polymer; and
less than 2000 ppm phosphorus,
wherein the fibers have an average fiber diameter of less than 20 microns;
wherein the zinc is provided via a zinc compound and the phosphorus is provided via a phosphorus compound different from the zinc compound; and
wherein the antimicrobial fibers demonstrate a Staphylococcus Aureus reduction of at least 90%, as measured by ISO 20743-13.
8. The antimicrobial fibers of claim 7 , wherein the weight ratio of zinc to phosphorus is: at least 1.3:1; or less than 0.64:1.
9. The antimicrobial fibers of claim 7 , wherein the antimicrobial fibers comprise less than 3100 ppm of zinc.
10. The antimicrobial fibers of claim 7 , wherein the antimicrobial fibers have a zinc retention greater than 70% as measured by a dye bath test.
11. The antimicrobial fibers of claim 7 , wherein the antimicrobial fibers comprise less than 3200 ppm of zinc, wherein the antimicrobial fibers comprise a delusterant including at least a portion of the phosphorus, and wherein the antimicrobial fibers demonstrates a Staphylococcus Aureus reduction of at least 90%, as measured by ISO 20743-13.
12. The antimicrobial fibers of claim 7 , wherein the antimicrobial fibers comprise nylon 66 or nylon 6/66.
13. A process for preparing an antimicrobial nonwoven polyamide structure having permanent antimicrobial properties, the process comprising:
preparing precursor polyamide comprising an aqueous monomer solution;
dispersing less than 4000 ppm zinc within the precursor polyamide;
dispersing less than 2000 ppm phosphorus within the precursor polyamide;
wherein the zinc is provided via a zinc compound and the phosphorus is provided via a phosphorus compound different from the zinc compound;
polymerizing the precursor polyamide to form a polyamide composition;
spinning the polyamide composition to form antimicrobial polyamide fibers; and
forming the antimicrobial polyamide fibers into the antimicrobial nonwoven structure having a fiber diameter of less than 20 microns; and
wherein the polyamide structure demonstrates a Staphylococcus Aureus reduction of at least 90%, as measured by ISO 20743-13.
14. The process of claim 13 , wherein the antimicrobial nonwoven polyamides have a zinc retention greater than 70% as measured by a dye bath test.
15. The process of claim 13 , wherein the weight ratio of zinc to phosphorus is: at least 1.3:1 or less than 0.64:1.
16. The process of claim 13 , wherein the polyamide is melt spun by way of melt blowing through a die into a high velocity gaseous stream.
17. A process for preparing an antimicrobial nonwoven polyamide structure having antimicrobial properties, the process comprising:
preparing a formulation comprising a polyamide, less than 4000 ppm zinc dispersed within the polyamide; and less than 2000 ppm phosphorus dispersed within the polyamide, wherein the zinc is provided via a zinc compound and the phosphorus is provided via a phosphorus compound different from the zinc compound;
spinning the formulation to form antimicrobial polyamide fibers having a fiber diameter c less than 20 microns; and
forming the antimicrobial polyamide fibers into antimicrobial nonwoven polyamide structure;
wherein the fibers were spun using a die pressure less than 275 psig; and
wherein the polyamide structure demonstrates a Staphylococcus Aureus reduction of at least 90%, as measured by ISO 20743-13.