HK1173111A - Elastic fabric with adhesive - Google Patents

Description

Elastic fabric with adhesive

Cross reference to related applications

This application claims priority from U.S. provisional application 61/261594 filed 11/16, 2009.

Background of the invention.

Technical Field

The present invention relates to an article comprising an elastomeric fabric consisting essentially of elastomeric fibers in combination with an adhesive. When the adhesive is applied to the elastomeric fabric, the article is essentially an elastic film. The article may be joined or attached to other fabrics, which may optionally be elastic fabrics. The invention also includes a method of making an article.

Brief description of the related Art

Various polymers, such as polyamides, polyolefins, and polyurethanes (including polyurethane-ureas) can be used as adhesives for various substrates (including fabrics). Examples of films include thermoplastic polyurethane, polyamide, and polyolefin films (available from Bemis Associates, Shirley, MA). Examples of polyurethane films cast and dried from aqueous polyurethane dispersions are disclosed in U.S. Pat. No. 7,240,371 and U.S. patent application publication 2008/0004395a1, both of which are incorporated herein by reference in their entirety.

Conventional adhesives are not breathable. In the areas joined by the adhesive film, the garment is impermeable to air, causing heat and discomfort to the wearer of the garment. To obtain sufficient strength and engagement force, many films are made with greater thicknesses, which can result in fabrics and garments that are not as stiff and rough.

The launderability of films joined in garments is a problem for garments that are subjected to repeated domestic and/or industrial laundering. Currently, high bonding temperatures and long times are necessary to obtain a durable bond.

Summary of The Invention

The bondable elastic film of some aspects can reduce the bonding temperature and reduce the bonding time. This translates into reduced energy, reduced manufacturing time, and reduced potential for damage to delicate fabrics.

The articles of some aspects comprise at least one heat-activated adhesive (e.g., an adhesive polymer) and an elastic fabric comprising about 50% by weight or greater elastomeric fibers, including up to about 100% by weight elastomeric fibers, based on the weight of the fabric. The elastic fabric provides excellent recovery force and shape retention, while the adhesive provides strong bonding force. The adhesive is selected from the group consisting of polyurethanes, polyolefins, polyamides, polyesters, and combinations thereof. The addition of an elastic fabric to the film allows for increased strength and softness of the film. The fabric/adhesive article may also provide breathability that the film would otherwise not achieve.

The combination of the elastic fabric and the adhesive renders the stretch and recovery properties of the adhesive unimportant, thus broadening the options for selecting a suitable adhesive. This is due to the improved recovery force of the elastic web as compared to conventional films that provide both recovery force and adhesion. Thus, the articles of some aspects provide high quality adhesive films with high recovery forces, and can produce high adhesion forces. The heat of bonding can be more easily transferred due to the many holes between the fibers in the elastic fabric. The fabrics can be joined with higher efficiency, lower temperature, shorter time, and less damage to the fabrics.

In another aspect, the article includes an elastic fabric comprising from about 50% to about 100% by weight elastomeric fibers based on the weight of the fabric, such as 100% by weight elastomeric fibers without companion fibers. The fabric may have a structure selected from the group consisting of weft knit (e.g., circular knit), warp knit, and nonwoven.

In another embodiment, the invention is a method of making a substrate comprising:

(a) fabric with 100% elastic fiber, fusible fiber as option;

(b) applying an adhesive polymer to the fabric to form an adhesive film;

(c) the adhesive film is joined to the garment fabric.

Detailed Description

Elastomeric fibers are commonly used to provide stretch and elastic recovery in fabrics and garments. An "elastomeric fiber" is a continuous filament (optionally a coalesced multifilament) or a plurality of filaments having an elongation at break of more than 100% independent of any crimp without a diluent. Stretched to twice its length in (1); (2) keeping for 1 minute; and (3) upon release, the elastomeric fibers retract to less than 1.5 times their original length within 1 minute of release. As used herein, "elastomeric fiber" means at least one elastomeric fiber or filament. Such elastomeric fibers include, but are not limited to, rubber filaments, bicomponent filaments (which may be based on rubber, polyurethane, etc.), lastol, and spandex. Throughout the specification, the terms "elastomer" and "elasticity" are used interchangeably.

"spandex" is a manufactured filament in which the filament-forming substance is a long-chain synthetic polymer comprising at least 85% by weight of a segmented polyurethane.

"elastoester" is a manufactured filament in which the fiber-forming substance is a long-chain synthetic polymer composed of at least 50% by weight of an aliphatic polyether and at least 35% by weight of a polyester. Although not elastomeric, elastomeric esters may be included in some fabrics.

"bicomponent filaments" are continuous filaments comprising at least two polymers bonded to each other along the length of the filament, each polymer being of a different class, such as an elastomeric polyetheramide core and a polyamide sheath having lobes or wings. Examples of bicomponent polyurethane (or spandex) fibers/filaments are disclosed in PCT/US09/60370 filed 10-12, 2009, which is incorporated herein by reference in its entirety.

"Lastol" is a fiber of a crosslinked synthetic polymer having low but significant crystallinity, consisting of at least 95% by weight of ethylene and at least one other olefin unit. Such fibers are elastic and substantially heat resistant.

"wrapped" elastomeric fibers are fibers surrounded by, entangled with, or intermingled with hard yarns. Wrapped yarns comprising elastomeric fibers and hard yarns are also referred to herein as "composite yarns". Hard yarn wrapping is used to protect the elastomeric fibers from abrasion during the weaving process. This abrasion can lead to breakage of the elastomeric fibers with consequent process interruptions and undesirable fabric non-uniformities. In addition, the wrapping helps stabilize the elastomeric fiber elasticity so that the composite yarn elongation can be controlled more uniformly during the weaving process than with bare elastomeric fibers. Throughout the specification, the terms "elastic core yarn", "composite yarn", "core yarn" and "composite elastic core yarn" are all used interchangeably.

The composite yarn comprises: (a) wrapping the elastomer fiber with a hard yarn; (b) double wrapping the elastomer fibers with hard yarn; (c) continuously wrapping (i.e., core spun) the elastomeric fiber with short fibers, followed by winding during winding; (d) mixing and entangling the elastomer and the hard yarn with each other by an air nozzle; and (e) entangling the elastomeric fibers and the hard yarn together.

"compressed" or "compressed" refers to an article that has been subjected to heat and/or pressure to provide a substantially flat structure.

"dispersion" refers to a system in which the dispersed phase consists of fine particles and the continuous phase can be a liquid, solid, or gas.

By "aqueous polyurethane dispersion" is meant a composition that has been dispersed in an aqueous medium (e.g., water, including deionized water) comprising at least one polyurethane or polyurethane-urea polymer or prepolymer (e.g., a polyurethane prepolymer as described herein), optionally comprising a solvent.

Unless otherwise indicated, "solvent" refers to a non-aqueous medium, wherein the non-aqueous medium includes organic solvents, including volatile organic solvents (such as acetone) and slightly less volatile organic solvents (such as MEK or NMP).

"solvent-free" or "solvent-free system" refers to a composition or dispersion in which the bulk of the composition or dispersed components is not dissolved or dispersed in a solvent.

"molded" articles refer to products that change the shape of an article or shaped article in response to heat and/or pressure.

In some embodiments, the present invention is a multilayer article comprising at least one layer of stretch fabric having from about 50% to 100% elastomeric fibers, which may be a single elastomeric fiber or a combination of different elastomeric fibers, such as spandex and rubber fibers or spandex and lastol fibers. The elastomeric fibers may be present from about 50% to about 100% by weight based on the weight of the fabric, including fabrics comprising from about 70% to 100%, from about 80% to 100%, from about 90% to 100%, and from 95% to 100% (where each percentage is the presence of elastomeric fibers based on the total weight of the fabric).

The fabric may comprise only elastomeric fibers, i.e. 100% elastomer. Alternatively, the elastomeric fibers in the fabric may be combined with one or more companion yarns. Where the elastic fabric includes one or more companion yarns (in addition to the elastomeric fibers), the companion yarns may be hard yarns or elastic fibers that exhibit less stretch/recovery. Examples of hard yarns include yarns made from natural and synthetic fibers. Suitable natural fibers may be cotton or other cellulosic fibers, silk or wool, and the like. Synthetic fibers include, inter alia, nylon, polyester. Mixtures of different fibers may also be included (mixtures may include different natural fibers, different synthetic fibers, or both).

Examples of elastic fibers include polyester bicomponent fibers (available from INVISTA, Wichita, KS as LYCRA T400 fibers), lastol, rubber, and polybutylene terephthalate (PBT). These fabrics may include elastomeric fibers with hard yarns. Alternatively, the fabric may include elastomeric yarns with another elastomeric yarn.

"Fabric" refers to a knitted, woven, or nonwoven material. The knitted fabric may be plain knitted fabric, circular knitted fabric, warp knitted fabric, narrow stretch fabric and mesh fabric. The woven fabric may be any structure such as satin weave, twill weave, plain weave, oxford weave (oxford weave), basket weave, and narrow stretch fabric. The nonwoven material may be meltblown, spunbond, wet-laid, staple fiber webs based on carded fibers, and the like.

The article may also comprise at least one layer of an adhesive polymer. The adhesive may be in the form of a film, fabric, porous sheet or dispersion. They adhere uniformly to the elastic fibers. The elastic fabric is adjacent to or between the adhesive layers and may also provide stretch and recovery, increased elastic modulus, moldability, shape retention, and flexibility to the article.

In some aspects of the article, an adhesive other than a polyurethane (including polyurethane-urea) dispersion or film may be combined with the elastic fabric. Examples of adhesives include any hot melt adhesive, cyanoacrylate, epoxy, polyvinyl acetate, plastisol (including rubber), thermoplastic adhesives (including polyurethanes, polyesters, and polyamides), silicone, latex polymers, thermoset adhesives, pressure sensitive adhesives, and combinations thereof.

The adhesive may be used to prepare an adhesive/elastic fabric composite article or to adhere a composite article to a fabric. Additional adhesives may optionally be included when the composite article is attached to a separate fabric or garment. The fabric or garment may comprise another fabric structure and may exclude elastomeric fibers.

The adhesive may include continuous or discontinuous applications for the elastic fabric/adhesive composite article or when the composite article is incorporated into a fabric or garment. Examples of discontinuous application of adhesive include dots, vertical lines, horizontal lines, diagonal lines, grids, and combinations thereof.

Examples of commercially available hot melt adhesives in the dot structure are available under the trade name Pinbond @fromFreudenberg Gygli GmbH, Weinheim, Germany and are used to join elastic textiles. In addition, the elastic fabric/adhesive composite article may also adhere as an adhesive to more than one layer of any garment or polyurethane-urea film, as described in some aspects.

A variety of different fibers and yarns may be used in some aspects of fabrics and garments. These include cotton, wool, acrylic, polyamide (nylon), polyester, spandex, regenerated cellulose, rubber (natural or synthetic), bamboo, silk, beans, or combinations thereof. Additional fabric layers may be attached/bonded, etc. to the elastic fabric.

These articles may be formed into fabrics and/or garments by any suitable method. The adhesion in the composite article may be in the form of an attachment, but also joining or sewing may be used.

Analytical method

The following analytical methods were used in the following examples.

Adhesive bond peel strength

ASTM D903-93, the entire disclosure of which is incorporated herein by reference, is modified for testing film laminated fabrics. The sample size used for the test was 1 inch by 6 inches (2.5cm by 15 mm). The separation rate was 2 inches/minute (5 cm/minute). Data are reported as pounds force per inch of sample width (kg/mm) as shown in the table.

Examples

The following table describes some suitable elastic fabric/adhesive composite articles described in some aspects. The "LYCRA type" category describes LYCRA fibers (available from INVITA, Wichita, KS) for use in fabrics made of 100% LYCRA fibers. LYCRA dispersions refer to dispersions of LYCRA 2.0 tapes and films (available from INVITA, Wichita, KS).

Claims (17)

1. An article comprising a plurality of layers, comprising:

(a) an elastic fabric comprising about 100% by weight elastic fiber, based on the weight of the fabric, and

(b) at least one adhesive.

2. The article of claim 1, wherein the adhesive is a hot melt adhesive, a contact adhesive, a thermoplastic adhesive, or a polyurethane-urea aqueous dispersion (including hot melt nonwovens and spot-dispensing).

3. The article of claim 2, wherein the dispersion is substantially free of solvent.

4. The article of claim 1 wherein the adhesive is a mixture of a hot melt polymer and an aqueous polyurethane-urea dispersion.

5. The article of claim 1 wherein said stretch fabric is a circular knit, a warp knit, a woven and/or a nonwoven.

6. The article of claim 1 wherein said elastomeric fiber is spandex.

7. Fabrics and garments comprising the article of claim 1.

8. A method of making the article of claim 1.

9. A fabric comprising a plurality of layers, comprising:

(a) at least two layers; and

(b) at least one article of claim 1.

10. The article of claim 9, wherein the at least two layers are selected from the group consisting of (a) two fabric layers; (b) two foam layers; (c) a fabric layer and a foam layer; and combinations thereof.

11. The article of claim 10, wherein the article is molded.

12. The article of claim 10, wherein the article is compressed.

13. The article of claim 10 wherein the article of claim 1 extends over the entire area of the multilayer article.

14. The article of claim 10, wherein the article of claim 1 extends to a portion of the area of the multilayer article.

15. An article comprising a plurality of layers, comprising:

(a) an elastic fabric comprising from about 50% to 100% elastic fiber by weight of the fabric, and

(b) at least one adhesive.

16. The article of claim 15, wherein the elastic fiber is present in an amount of 95% to about 100% by weight based on the weight of the fabric.

17. The article of claim 15 wherein the stretch fabric consists essentially of one or more elastic fibers.