Elastic Composite Film and Composite Fabric and Production Process Thereof

a composite fabric and elastic technology, applied in the field of composite fabric and elastic composite film, can solve the problems of increasing production cost, poor appearance, and insufficient elastic properties

Inactive Publication Date: 2013-08-08
W L GORE & ASSOC GK
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

The solution provides a composite film and fabric with superior elongation and recovery properties while maintaining waterproof and water vapor permeability, enhancing practical durability and reducing production costs by preventing necking and improving appearance.

Problems solved by technology

Although sintered, porous expanded polytetrafluoroethylene (ePTFE) films and fabrics comprised of a laminate of such expanded, sintered, porous PTFE film and cloth have been proposed and used practically as waterproof, water-vapor-permeable films, they do not have adequate elastic properties.
Consequently, in the case of a producing a product with this method, products can only be produced having a width that is narrower than the width of the cloth used in production, thereby increasing production cost.
In addition, since wrinkles form in the product, the appearance becomes poor.
In addition, in the case of having carried out elongation treatment in the longitudinal direction while preventing necking in the transverse direction under the conditions described above, due to the use of a sintered ePTFE film, breakage occurs due to elongation of roughly 20%, thereby making elongation treatment difficult.
Since the ePTFE film is unsintered, a peel-off phenomenon of the surface layer occurs caused by insufficient cohesive force in the direction of thickness.
In the case of coating on one side, however, the lack of cohesive force on the uncoated side becomes pronounced, and even if both sides are coated, if voids remain within the ePTFE film, cohesive force is inadequate at those portions.
Although practical durability is inadequate unless unsintered ePTFE films are completely impregnated with a resin having hydrophilic groups to prevent the peel-off phenomenon of the surface layer and the like, complete impregnation makes it difficult to express a high level of water vapor permeability.

Method used

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  • Elastic Composite Film and Composite Fabric and Production Process Thereof
  • Elastic Composite Film and Composite Fabric and Production Process Thereof
  • Elastic Composite Film and Composite Fabric and Production Process Thereof

Examples

Experimental program
Comparison scheme
Effect test

example 1

[0093]Ethylene glycol was added to a hydrophilic polyurethane resin (Dow Chemical Co., trade name: Hipore 2000) at a ratio in which the equivalent weight ratio of NCO / OH is 1, followed by the addition of toluene so that the concentration of the polyurethane pre-polymer was 90% by weight, and mixing and stirring well to prepare a coating liquid. This coating liquid was coated onto a sintered ePTFE film manufactured by Japan Gore-Tex Inc. (thickness: 50 μm, maximum pore diameter: 0.3 μm, porosity: 80%, rupture elongation percentage in transverse direction as determined in a tensile test: 260%), and cured by heating to obtain a multilayer film in which the thickness of the polyurethane resin layer was 25 μm (thickness of impregnated portion: 15 μm, thickness of surface portion: 10 μm). Next, this multilayer film was subjected to continuous elongation treatment in the transverse direction under the conditions shown in Table 1 with an apparatus having a tenter that spreads apart in a hea...

example 2

[0099]An elastic composite film was produced under the same conditions as Example 1 with the exception of using an elongation temperature of 170° C., elongation factor of 1.6 times in the transverse direction, and elongation speed of 13% / sec. The evaluation results are shown in Table 1. A film having superior elastic properties was obtained having an elongation percentage of 42% in the transverse direction, an elongation recovery rate of 85% and stress of 1.4 N / 15 mm during 10% elongation, by increasing the elongation factor and setting a faster elongation speed.

TABLE 1ElongationElongationElon-ElongationpercentagerecoveryStressgationfactor inElon-inrate induring temper-transversegationtransversetransverse10%aturedirectionspeeddirectiondirectionelongationNo.(° C.)(times)(% / sec)(%)(%)(N / 15 mm)Ex. 11501.5635851.5Comp.1501.5119802.6ex. 1Comp.2201.565502.7ex. 2Ex. 21701.61342851.4

example 3

[0100]An adhesive manufactured by Nippon NSC Ltd. (“BondMaster”) was transferred in the form of dots on the sintered ePTFE film side of the elastic composite film of Example 2 using a gravure roller having a transfer surface area of 40%, followed by laminating a knit cloth (Nylon / Spandex blend: 75 / 25, gauge: 28G, weight: 58 g / m2, transverse direction elongation percentage: 150%, elongation recovery rate: 95%) onto the transfered side, and applying pressure to obtain a bi-layer structured, elastic composite fabric. The resulting elastic composite fabric had elastic characteristics of an elongation percentage of 35% in the transverse direction and elongation recovery rate of 93%. In addition, the adhesive durability between the film and liner fabric of this laminate was evaluated based on the presence or absence of the peel-off by visual observation of a sample following 100 hours of continuous agitation laundering using tap water containing no detergent at a bath ratio of 1 / 60, bath ...

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Abstract

An elastic composite film provided with a sintered ePTFE film and an elastomeric resin layer, produced by continuously forming the elastomeric resin layer on at least one side of the sintered ePTFE film, continuously elongating the resulting multilayer film at less than the yield point of the expanded, sintered, porous film and at an elongation factor of 1.3 times or more in the biaxial directions, or in the uniaxial direction without contracting in the direction perpendicular to the direction of elongation, and relaxing the resulting elongated multilayer film, wherein when the composite film is elongated by 10% in the longitudinal and / or transverse direction, the tensile stress of the composite film is 2.5 N / 15 mm or less, and / or the elongation percentage of the composite film in the longitudinal and / or transverse direction is 30% or more and the elongation recovery rate is 70% or more.

Description

CROSS REFERENCE TO RELATED APPLICATIONS[0001]This application is a divisional of U.S. patent application Ser. No. 11 / 814,952, filed Jul. 27, 2007, the entire contents of which are expressly incorporated herein by reference in its entirety.TECHNICAL FIELD[0002]The present invention relates to a composite film and a composite fabric, comprising an expanded, sintered, porous polytetrafluoroethylene (PTFE) film, having elastic properties, and preferably having waterproof water vapor permeability, and production processes thereof.BACKGROUND ART[0003]Although sintered, porous expanded polytetrafluoroethylene (ePTFE) films and fabrics comprised of a laminate of such expanded, sintered, porous PTFE film and cloth have been proposed and used practically as waterproof, water-vapor-permeable films, they do not have adequate elastic properties.[0004]For example, Japanese Unexamined Patent Publication No. 51-30277 (see U.S. Pat. No. 3,953,566) discloses a technology for obtaining an expanded, si...

Claims

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Application Information

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Patent Type & AuthorityApplications(United States)
IPC IPC(8): B32B5/24B32B38/00B29C55/00D03D15/56
CPCA41D31/0016B32B27/08B32B37/144B32B5/245B32B2307/724B32B2327/18B29C55/005B32B38/0012Y10T442/3016Y10T442/40Y10T442/601Y10T428/249991A41D31/185A41D31/102A41D31/02B32B5/02B32B27/322B32B27/40B32B2038/0028B32B2307/7265
InventorIMAI, TAKASHI
OwnerW L GORE & ASSOC GK