Antimicrobial transfer substrates and methods of use therewith

Abstract

Specific transfer methods and articles to impart a metal-ion based antimicrobial finish to recipient textile surfaces. Such treatments preferably comprise silver ions, particularly as constituents of inorganic metal salts or zeolites. In particular, the inventive method involves the application of a solid, inorganic antimicrobial material to a donor substrate (such as a dryer sheet), and the subsequent placement of such a substrate within a tumble drying machine containing textile fabrics and operating the machine. The donor substrate, upon contact with the recipient textile fabrics, transfers antimicrobially effective amounts of the metal-ion based compounds to such recipient fabrics thereby imparting at least a temporary antimicrobial finish over at least a portion of such fabrics. The donor substrates, with either the antimicrobial compound alone or mixed with standard tumble dryer additives (such as perfumes, fabric softeners, fiber lubricants, and the like) are also contemplated within this invention.

Description

[0001] This application is a continuation-in-part of co-pending application Ser. No. 09 / 572,816, filed on May 17, 2000. This parent application is herein entirely incorporated by reference.[0002] This invention relates to specific transfer methods and articles to impart a metal-ion based antimicrobial finish to recipient textile surfaces. Such treatments preferably comprise silver ions, particularly as constituents of inorganic metal salts or zeolites. In particular, the inventive method involves the application of a solid inorganic antimicrobial material to a donor substrate (such as a dryer sheet), and the subsequent placement of such a substrate within a tumble drying machine containing textile fabrics and operating the machine. The donor substrate, upon contact with the recipient textile fabrics, transfers antimicrobially effective amounts of the metal-ion based compounds to such recipient fabrics thereby imparting at least a temporary antimicrobial finish over at least a portio...

AI Technical Summary

Benefits of technology

[0007] It is thus an object of the invention to provide a simple manner of effectively treating a fabric article with an antimicrobial inorganic solid treatment. Another object of the invention is to provide a non-yellowing antimicrobial treatment through the utilization of a simple in-home or industrial-level laundry tumble dryer method. Yet another object of the invention is to provide a metal-ion-treated textile that is non-yellowing, non-irritating to skin, and which provides antimicrobial properties, through a simple, in-home application method.

[0018] It has suprisingly been determined that polyolefin donor fabrics (in sheet form, for example), provide an highly effective transfer mechanism for antimicrobial deposition on the receipient fabrics. Although polyester, foam, acetate, linen, and the like, all provide effective antimicrobial transfer, it has been found that substantial amounts of antimicrobial are retained on the donor fabric surface after standard drying procedures are undertaken. However, with polyolefins, most notably polypropylene nonwoven fabric donor sheets, the amount of antimicrobial released is much higher and thus provides a more effective mechanism for transferring the desired antimicrobial in greater amounts to the target recipient fabrics. Considering the high temperatures associated with such drying steps, the ability for the polypropylene to withstand such conditions while simultaneously releasing a majority amount of the antimicrobial from its surface, is highly unexpected.

[0033] Apparently, the best overall effect is a relatively cool, dry atmosphere within the selected dryer machine. However, the efficacy of the other conditions shows the viability of this invention under different conditions as well.

[0050] Thus, surprisinly, polypropylene donor sheets provide extremely effective release mechanisms for the antimicrobial. Without any thickener, all of the antimicrobial was released; with, still 67% was released. Although the polyester provided much lower release, as noted above, the log kill rates with such antimicrobial transfer rates are extremely high and thus are very effective as well.

Problems solved by technology

Although the incorporation of such a compound within liquid or polymeric media has been relatively simple, other substrates, including the surfaces of textiles and fibers, have proven less accessible.

Such proposed applications have been extremely difficult to accomplish with triclosan, particularly when wash durability is a necessity (triclosan easily washes off any such surfaces).

Furthermore, although triclosan has proven effective as an antimicrobial compound, the presence of chlorines within such a compound causes skin irritation which makes the utilization of such with fibers, films, and textile fabrics for apparel uses highly undesirable.

However, such an application is limited to those types of fibers; it does not work at all for natural fibers and specifically does not work for and / or within polyester, polyamide, cotton, spandex, etc., fabrics.

Furthermore, this co-extrusion procedure is very expensive.

Furthermore, attempts have been made to apply such specific microbiocides on the surfaces of fabrics and yarns with little success from a durability standpoint.

A topical treatment with such compounds has never been successfully applied as a durable finish or coating on a fabric or yarn substrate.

However, such melt spun fibers are expensive to make due to the large amount of silver-based compound required to provide sufficient antimicrobial activity in relation to the migratory characteristics of such a compound within the fiber itself to its surface.

However, these particular methods disclose the transfer of gelled or liquefied (due to the friction and heat within the tumble dryer itself) organic treatments and / or compounds from the sheet to the textile.

This past lack of interest was due to the difficulties involved with actually keeping the solid compound(s) in place on the dryer sheet surface.

Furthermore, the transfer from dryer sheet to textile would also appear to be rather difficult since the transferred materials are solids and most likely possess rather high molecular weights.

Even if the solids are contacted with the target textile, the ability for the treated surface to retain such solids during tumble drying seems nearly impossible.

To date, such a specific procedure incorporating such inorganic solid materials has not been accorded the industry by the prior art.