CA1168424A - Antimicrobially treated fabric construction - Google Patents

Abstract

ANTIMICROBIALLY TREATED FABRIC CONSTRUCTION
Abstract of the Disclosure A unique fabric construction having a backing fabric and a face fabric. At least one of the fabrics is made at least, in part of yarns formed from synthetic fibers which have incorporated thereinto an antimicrobial agent. In some embodiments a tie yarn joins the two faces in plated relation. Even with minimal contact of the yarns in the two fabrics, the antimicrobial agent migrates from within the treated fibers in the one fabric to the surface thereof and transfers to the yarns in the other fabric. Thus there is imparted antimicrobial protection to both fabric faces while maintaining the advantages of naturally occurring, untreated fibers in one of the fabrics.

Description

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ANTIMICROBIALLY TREATED ~ABRIC CONSTR~CTION
Background and Summary Or the lnvention This invention relates to the production Or lmproved antimicrobial fabrics and articles made thererrom, which fabrics and articles do not lose the desirable attributes Or comfort, soft hand, absorbency, better appearance which have hereto~ore been available only by utilization of naturally occurring articles. "Anti-microbial" is used herein to include bot~ fungic~dal and antibacterial agents, the iatter runctloning as either bacteriostatic or bactericidal agents. Much research has been conducted in this field with consld-erable development in the areas Or clothing and intimate apparel. Errorts have been somewhat concentrated in the areas o~ deodorizing or inhibiting bacterial, fungal, or microbial growth in synthetic textile articles such as surgical gowns and masks, institutional textile products, and clothing items such as shirts, T-shirts, - and athletic uniforms, etc. Inhibiting rungal growth serves to protect the rabric itself, while the inhibition o~ bacterial growth prevents odor, since o~dor is caused by the bacterial breakdown o~ organic matter. Therefore, both characteristics are desirable.
Many approaches have proved impractical or have demonstrated limited success. Two approaches are described in U.S. Patents No. 3,922,723 and No. 3J296~ooo.
Utilization Or these teachings has demonstrated that the antimicrobial topical treatments to the yarns and/or rabrics is relatively shortlived. This fact is particularly true~ror articles o~ clothing the surfaces Or which are sub~ected to mechanical abrasion during repeated cleaning and launderings. Each cleaning process removes a certain amount Or the antimicrobial agent until the agent is dis-sipated and Or no effectlveness.

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Another approach to antimicrobial yarns and ~abrlcs is disclosed in applicant's previous patent, U.S. No.
39959,556, directed to a composite yarn construction showing a desirable level of antimicrobial activity.
The yarn disclosed therein includes naturally occurring ribers intimately combined with a selected group o~
antimicrobially treated synthetic fibers. The results are characterized by the migration of the antimicrobial agent rrom within the intermolecular structure of the synthetic ~ibers onto the surface Or and throughout the naturally occurr~ng fibers, to impart antibacterial properties not only to the synthetic fibers but also to the naturally occurring ~ibers. A preferred embodiment of this yarn is a construction from synthetic polymeric fibers having an antimicrobial agent incorporated therein in an amount equalling at least 0.1% by weight Or the polymeric resin~ the antimicrobial agent selected rrom the group consisting of 2,4,4'-trichloro-2'-hydroxydiphenyl ether; 2,2'-methylenebis-(3,4,4'-20 trichlorophenol); and 2,2'-thiolis, 4,6-dichlorophenol.
The chemical data describing the antimicrobial treatment o~ the synthetic fibers is rully described in applicant's aforementioned U.S. Patent 3,959,556, the disclosure Or which is hereby incorporated by reference in the present 25 application.
The a~orementioned earlier patent 3,959,556 requires intimate admixing Or antimicrobially treated fibers and naturally occurring fibers in order to transrer the erfect to the natural fibers. The present application 30 is directed to achieving the same e~I'ect without such intimate admixing Or ribers. This errect is achieved b~ constructing a "two-race" fabric, one Or the ~aces formed at least in part by synthetic yarn which has been l'treated" with an antimicrobial a~ent as described 35 in the patent 3,959,566, the other Or the f2ces com-prising untreated yarn.

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As used hereln "treated" wlth an antimicrobial agent includes the incorporation of the agent ~nto the inter-molecular s~ructure Or the resin so tha~ it m~grates to the surrace thereof maintaining a relatlvely permanent treatment thereo~. The "two-race" ~abric may be a plated rabric with or without a tie yarn, it may be a carpet construction with a woven back~ng havlng other yarn tufted there~o, or other similar constructions ln which yarns o~ one type are ~oined together to rorm a - 10 layer in one plane while yarns Or another type are joined together to form a second layer in generally a second plane.
In one embodiment, the fabric formed according to the present invention is used to construct athletlc sweatshirts having a face fabric and a backing fabric.
The face fabric is rormed Or a 50% acrylic-50Z cotton, antimicrobially untreated yarn; and the backing rabric ~s rormed Or a 100% acrylic, antimicrobially treated yarn. The interconnecting or tie yarn ma~ be either riber, pr~ererably the same as in the race~
Experimentation with such a fabric structure has demonstrated the unexpected abilit~ Or the active antimicrobial agent to migrate all the way from a backing fabric to a race fabric. Although the two ~aces are not in intimate contact with each other due to the tie yarn in between, such a plated fabrlc struc-ture has been ~ound errective in not only the treated backing rabric, but also in the untreated face f~bric.
Demonstration Or the above unexpected capabilities Or a treated fabric to protect an adjacent untreated fabric enables the product on Or articles Or apparel and other manuracture with advantages theretorore unattainable. For example, in the aforementioned sweatshirt construction, lt is not essential that the face rabric which normally rorms the outside o~ the sweatshlrt contain any antimicrobially treated, synthetic Z~

yarn. Rather a ~abric ~ormed Or untreated 7 perhaps natural~ ~iber having a more pleasing appearance and ~eel (hand) and wearability can be used on the outside.
The antimicrobially treated, synthetic yarn then can be S used in the backing fabric alone. The antimicrobial agent will migrate rrom the backing ~abric to the untreated facing rabric. Alternatively the synthetic, treated rabric might be in the face, while the backing fabric could utilize more comfortable natural yarns next to the skin. Other articles might use either alternative depending on the desired results.
Where in the past it has always been necessary that the antimicroblal fibers be intimately admixed with the non-antimicrobial ribers, as by blending, plying and the llke,- and the fabric rormed therefrom necessarily in contact with the body Or the wearer, it is now possible to alter that arrangement almost as desired. It is now possible that the treated and untreated fibers or rabrics can be only ad~acent, not necessarily interlaced or intertwined, and they may even be tied together by an untreated yarn or rabric.
Thls is also quite advantageous rrom an appearance standpoint. The visible race fabric need not have any synthetic yarns therein, but can have antimicrobial properties resulting from an invisible, treated backing fabric.
The ability ar the one race having one antimicrobial properties to protect against microbial growth on the other is far more than other known approaches Or treated yarns and/or fabrics have orrered. Growth of mildew and odor forming bacteria has been signiricantly decreased as will be discussed in the example below.
A primary object Or the present invention is the provision of a fabric construction wherein an anti-microbially treated fabric i5 rormed in a "two-race" or layered relation with a non-antimicrobial, or untreated fabricg with the effect being that the untreated rabric receives the benefits o~ the antlmicrobial agent in the treated fabric even where the two rabrics are not intimately ~oined. ~his objectlve has been realized with the antimicrobial properties of the combination exceeding expectations.
Other ob~ects and a fuller understand~ng Or the invention will become apparent upon reading the ~ollowing detailed description vf a preferred embodiment along with the accompanying drawings in which:
Figure 1 is a photograph of a sweatshirt lllus-trating a comparison of rabric formed by the technique o~ the presenk invention as compared with fabric formed according to conventional techniques;
Figure 2 is a photograph of a portion of the sweatshirt illustrating in enlarged fashion a small area thereof designated by the circle in Figure 1.
Detailed Description of a Preferred Embodiment As hereinbefore stated the present in~entlon is directed to a double face f`abric in which one race is ~ormed at least partially by yarns containing anti-microbially treated synthetic ~ibers. In a pre~erred embodiment the antimicrobial agent employed is

2,4,4'trichloro-2'-hydrGxydiphenyl ether. Alternatively, other agents such as disclosed in U. S. patent No.
2,919~200 to Dubin et al, and which include 2,2'-thiobis(4,6-dichlorophenol and 2,2'-methylenebis-(3,4,6-trichloro) phenol, may be employed. Still further known antibacterial or fungicidal agents posses-sing the properties of those above includenitrophenylacetate; phenylhydrazine; polybrominated salicylanilides, such as 594'-dibromosalicylanilide and

3~5,4~-tribromosalicylanilide; chlorhexidine; domiphen bromide; cetylpyridinium chloride; and benzethonium chloride. The lmportant characteristics of the agent~
besides its ability to kill and/or inhibit growth Or 4Z~

bacteria and ~ungus, is its ability to be stored wlthln the intermolecular structure of the polymer into whlch it is incorporated in a molten state, then migrate to the surface Or the polymeric fiber when the sur~ace equilibrium is disturbed as by laundering, or by the accumulatlon of moisture thereon in other rashions (perspiration for example~. In this manner continual ant~microbial properties are imparted until the original reservoir Or antimicrobial agent originally piaced in solution within the molten resin has been exhausted.
Types of fiber forming thermoplastic resins which are known to receive and be compatible with such agents include polyamides such as nylon 6~ and nylon 66;
acrylics; modacrylics, saran (80% vinylidene chloride);
vinyon (comonomer containing 85% vinyl chloride);
vinyl; polyvinylchloride; a vinyon/vinal (textile fiber made from polyvinyl alcohol) copolymer such as Cordelan (registered trademark Or Koh~in Co., Tokyo, Japan)j the polyolerins, particularly polypropylene and polyethylene, and nylon 4 (sold under trademark Tajmir by Chevron Corp., Odenton, Maryland). In one method of forming yarn the resin is admixed in either the dry or molten state or in a spinnable solution with a small amount (0.1-1.5% by weight) of the selected antimicrobial agent. The mixture is then heated (in the case of those admixed in the molten state) to a temperature above the melting point Or both the resin and the agent~ but below the decomposition point Or the agent.
The mlxture is then extruded or otherwise formed into rilaments desirably having a denier of at least 1.5.
The filaments are then preferably chopped into short fiber lengths (about one inch to about three inches)3 then ~ormed into yarn either alone or by blending with other types Or fibers. This concept can also, o~
course, be applied to monorilament or multifilament yarn.

More specirically in one example, 1.0% by welght of the agent 2,4,4'trichloro-2'-hydroxydiphenyl ether ls incorporated into acrylic resin and ~ormed into yarn according to the above procedure. The short yarn ~ibers are Or 1.7 denier and 40 mm. in length and are rormed into a resulting treated, 26 singles yarn.
An example of test clothing constructed during an experimentation program includes the sweatshirt lllus-trated in Figure 1 constructed as rollows. The sweat-shirt was constructed with a vertical seam in the bodydividing the shirt ln hal~. One half (left hand side) Or the body plus the sleeve was rormed o~ a coniventional plated construction consisting of a race rabric, a tie yarn3 and a backing rabric or race composed Or a blended, 15 non-antimicrobial or "untreated" spun yarn Or 28/1 50/50 cotton/acrylic. The entire neckband, waistband, and both currs were composed of the same blended~
untreated yarns.
The other halr (right hand side ) Or tfie shirt was 20 formed of a fabric constructed in accordance with the present invention. Such fabric included the 50% acrylic-50% cotton, non-antimicrobial yarn in the face; a similar tie yarn; and the a~oredescribed antimicrobial, treated 100% acrylic backing fabric. The backing 2~ ~abric prior to rabrication on both sides Or the sweat-shirt was brushed to provide a fleeced efrect, an optional treatment for appearance and comrort only.
Following construction, the above sweatshirt was worn daily ror a tWo-week period by a college-age male 30 during an exercise program. The test shirt was then closed in a plastic bag and le~t in the trun~ Or a car ror a three-week period during the high temperature months Or July and August. At the end Or that period the test shirt was removed rrom the bag and placed on a 35 hanger overnight, then photographed as illustrated ln F~gures 1 and 2.
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Examination of the sweatshirt indicated consider-ably less rungal growth due to migration Or the anti-microbial component rrom ~he backing to the ~ace ~abric.
The antimicrobially treated body and sleeve side Or the shirt revealed very mlnimal bacterial growth. Even the cuf~ on the treated side exhibited some inhibition.
Additlonal laboratory experiments have shown that the same ~abric treated with the antimicrobial a~ent, uslng the standard Bauer-Kirby experiments, also show a zone of inhibition against both gram positive and gram negative.
It will be apparent to those skilled in the art that further modirications may be made to the above disclosed invention, without departing rrom the scope Or the claims below.

Claims (6)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE PROPERTY
OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A fabric construction including a race fabric and a backing fabric and wherein:
a) said backing fabric formed from a first synthetic yarn comprising fiber-forming polymers having an antimicrobial agent incorporated therein in an amount equalling at least 0.1% by weight of the polymer, said antimicrobial agent characterized by its ability to be stored in the inter-molecular structure of the polymer and to migrate to the surface;
b) said race fabric formed from a second yarn including untreated fibers only;
whereby said antimicrobial agent transfers to said second face to inhibit antimicrobial growth thereon.

2. The fabric construction defined in Claim 1 wherein said face fabric and backing fabric are in plated relationship and further including a tie yarn formed from at least one of said first and second yarns and lying intermediate said first and second faces of said plated fabric.

3. The fabric construction according to Claim 1 wherein said antimicrobial agent is selected from the group consisting Or 2,4,4'-trichloro-2'-hydroxydiphenyl ether; 2,2'-methylenebis-(3,4,4'-trichlorophenol);
2,2'-thiobis, 4,6-dichlorophenol, said agent being added to said polymeric fibers in the amount of 0.1% by weight of said polymeric fibers.

4. The fabric construction according to Claim 1, 2 or 3 wherein said second yarn is formed from naturally occurring fibers.

5. A method of imparting an antibacterial charac-teristic to untreated yarns in a two-face fabric comprising the steps of.
a) froming a first fabric face yarns in a frist plane including fibers having no prior anti-bacterial treatment;
b) forming a second fabric face generally in a second plane relative to said first plane from yarns at least partially formed of fiber forming polymers having an antimicrobial agent incorporated therein in an amount equalling at least 0.1%
by weight of the polymer, said antimicrobial agent character-ized by its ability to be incorporated into the inter-molecular structure of the polymer and to migrate to the surface is the presence of moisture.

6. The method according to Claim 5 wherein said first and second races are plated together and a tie yarn fromed of untreated fibers is manipulated back and forth between the race and backing fabrics.