Hydrogel having anti-microbial properties
A method of making a hydrogel having antimicrobial properties. The hydrogel includes a hydrogel-forming polymer and an anti-microbial agent. The method includes mixing a hydrogel-forming polymer, such as a hydrophilic polymer, with water and cross-linking the polymer and water using an energy source. The method does not require any chemical additive to affect the cross-linking. The anti-microbial agent may be mixed with the hydrogel-forming polymer and water prior to cross-linking. Alternatively, the anti-microbial agent may be applied to a substrate onto which the hydrogel is placed such that the anti-microbial agent or the properties of the agent, or both, migrate into the hydrogel. The substrate may be a liner onto which the hydrogel is placed, a scrim located on or in the hydrogel, or other appropriate device.
1 . A method of making a hydrogel having anti-microbial properties comprising:
mixing a hydrogel-forming polymer with water; and
applying an energy source to crosslink the hydrogel-forming polymer with the water to form the hydrogel;
wherein the hydrogel further includes an anti-microbial agent; and
wherein the hydrogel is substantially free of any additive for enhancing cross-linking.
2 . The method of claim 1 , wherein the hydrogel-forming polymer is a hydrophilic polymer.
3 . The method of claim 2 , wherein the hydrophilic polymer is selected from the group consisting of starch, cellulose, cellulose derivatives, polyvinyl alcohol, polyalkylene oxide, polyethylene oxide, polypropylene glycol, poly(1,3-dioxolane), copolymers of polyethylene oxide, copolymers of poly(1,3-dioxolane), polyvinyl pyrrolidone, polyethylene glycol, polyacrylic acid, and polymethylene oxide.
4 . The method of claim 1 , wherein the hydrogel-forming polymer is added to the water in a weight ratio ranging from about one part hydrogel-forming polymer to about thirty-three parts water to about one part hydrogel-forming polymer to about three parts water.
5 . The method of claim 1 , wherein the anti-microbial agent comprises silver.
6 . The method of claim 5 , wherein the anti-microbial agent comprises silver coated fibers.
7 . The method of claim 1 , wherein the anti-microbial agent is added to the hydrogel in an amount of from about 0.1 percent to about 10 percent by weight.
8 . The method of claim 7 , wherein the anti-microbial agent is added to the hydrogel in an amount of from about 0.1 percent to about 3 percent by weight.
9 . The method of claim 1 , wherein the anti-microbial agent is mixed with the hydrogel-forming polymer and the water before application of the energy source.
10 . The method of claim 1 , wherein the mixture of the hydrogel-forming polymer and the water is applied to a substrate before application of the energy source.
11 . The method of claim 10 , wherein the substrate is selected from a group consisting of a top sheet, a bottom sheet, and a scrim.
12 . The method of claim 11 , wherein the substrate comprises a scrim selected from a group consisting of a mesh, a foam, a film, a woven material, and a non-woven material.
13 . The method of claim 12 , wherein the scrim comprises a high-density expanded polyethylene web.
14 . The method of claim 1 , further comprising an additive selected from a group consisting of an anti-fungal additive, an anti-microbial additive, a salt, a preservative, a pH adjuster, and a cross-linking inhibitor.
15 . The method of claim 1 , wherein the energy source is selected from a group consisting of an electron beam and gamma radiation.
16 . The method of claim 15 , wherein the energy source comprises a linear accelerator electron beam.
17 . A hydrogel having anti-microbial properties made according to the process of claim 1 .
18 . A personal care product having anti-microbial properties, comprising:
a hydrogel formed by mixing a hydrogel-forming polymer with water and applying an energy source to crosslink the hydrogel-forming polymer with the water to form the hydrogel, wherein the hydrogel further includes an anti-microbial agent and wherein the hydrogel is substantially free of any additive for enhancing cross-linking.
19 . The personal care product of claim 18 , wherein the personal care product is selected from a group consisting of a bandage, a cosmetic, a topical skin treatment, a wound dressing, a diaper, and a feminine care article.