Textured Water-Repellant Fabric

Abstract

Textured fabrics have raised projections separated by depressed areas. The raised projections have heights of 0.3 to 8 mm above the level of the surrounding depressed areas. The raised projections have a pitch of 0.25 to 10 mm. The raised projections are locked into the fabric by the presence of a flexible, crosslinked polymer. The fabrics are water-resistant and breathable. The raised projections and the depressed areas create channels through which water can flow, maintaining the air permeability of the textured fabric during rainstorms. The textured fabric may be part of an outerwear rain jacket.

Claims

1. A textured fabric coated with a crosslinked, flexible polymeric coating, the textured fabric being characterized in having an air permeability of at least 0.1 scfm (0.0472 l/s) as measured according to ASTM D737 wherein the textured fabric has at least one three-dimensional surface characterized by having raised projections separated by depressed areas, wherein the raised projections have a pitch 0.25 to 10 mm and height of about 0.3 to 8 mm above the height of the depressed areas, and wherein the crosslinked, flexible polymeric coating locks the three-dimensional surface into the textured fabric.

2. The textured fabric of claim 1 wherein the raised projections have an aspect ratio of 1 to 5 and the three-dimensional surface has 1.2 to 1600 raised projections per square centimeter.

3. The textured fabric of claim 1 wherein the three-dimensional surface includes 4 to 400 raised projections per square centimeter.

4. The textured fabric of claim 1 wherein the raised projections have a height of 0.5 to 5 mm above the height of the depressed areas.

5. The textured fabric of claim 1 wherein the raised projections have a conical, truncated conical, pyramidal or truncated pyramidal shape.

6. The textured fabric of claim 1 wherein the raised projections are arranged in a regular two-dimensional array.

7. The textured fabric of claim 1 wherein multiple depressed areas are contiguous and form a channel through which a fluid can flow.

8. The textured fabric of claim 1 wherein the raised projections have an aspect ratio of greater than 5.

9. The textured fabric of claim 8 wherein the raised projections span the fabric in at least one dimension.

10. (canceled)

11. The textured fabric of claim 1 which has an air permeability of at least 5 scfm (standard cubic feet per minute) (2.36 l/s) as measured by ASTM D737, using a SDL Atlas M021A instrument and a 20 cm.sup.2 test area.

12. The textured fabric of claim 1 wherein the three-dimensional surface has a water repellency rating of at least 90 on the AATCC Test Method 22.

13. The textured fabric of claim 1 which has a moisture transmission rate of 5000 to 500,000 g/m.sup.2/24 hour, as measured according to JISL 1099B1.

14. The textured fabric of claim 1 which has a weight of 10-200 gsm (grams per square meter).

15-19. (canceled)

20. A method for producing a textured fabric of claim 1, comprising a) contacting an impregnated starting untextured fabric against a textured template to form a three-dimensional surface on the impregnated fabric, which three-dimensional surface includes raised projections separated by depressed areas, wherein the raised projections have a pitch of 0.25 to 10 mm and have a height of about 0.3 to 8 mm above the height of the depressed areas, wherein i) the starting fabric has an untreated air permeability of at least 0.1 scfm (0.0472 L/s) as measured by ASTM D737; and ii) the starting fabric is impregnated with a curable coating composition that is applied to at least one surface of the starting fabric, wherein the curable coating composition 1) at 22 C. and at atmospheric pressure is a liquid or a suspension of one or more solids in a liquid phase and 2) is curable to form a crosslinked, hydrophobic flexible polymer; b) at least partially curing the curable coating composition while the impregnated fabric is in contact with the template to form a crosslinked, flexible polymeric coating and lock the three-dimensional surface into the fabric to form the textured fabric; and then c) removing the textured fabric from the template.

21. The process of claim 20 wherein the at least partial curing is performed in an oxygen-deficient environment.

22. The process of claim 20 wherein the heated temperature of the template is between 100 and 180 C.

23. The process of claim 20 further comprising, after step c), applying a second curable coating composition to the textured textile and curing the second curable coating composition on the textured textile.

24. A method for producing a textured fabric of claim 1, comprising a) providing a starting untextured fabric having an untreated air permeability of at least 0.1 scfm (0.0472 L/s) as measured by ASTM D737; b) applying a curable coating composition to at least one surface of the starting untextured fabric to form an impregnated fabric, wherein the curable coating composition 1) at 22 C. and at atmospheric pressure is a liquid or a suspension of one or more solids in a liquid phase and 2) is curable to form a crosslinked, hydrophobic flexible polymer; c) contacting the impregnated fabric against a heated, textured template to form a three-dimensional surface on the impregnated fabric, which three-dimensional surface includes raised projections separated by depressed areas, the raised projections having a pitch of 0.25 to 10 mm and a height of about 0.3 to 8 mm above the height of the depressed areas; then d) at least partially curing the curable coating composition in a low oxygen environment while the impregnated fabric is in contact with the template to form a crosslinked, flexible polymeric coating and lock the three-dimensional surface into the fabric to produce the textured fabric; and then e) removing the textured fabric from the template.

25. A garment including a textured fabric of claim 1 on at least one exterior surface thereof.

26. The textured fabric of claim 1 wherein the flexible, crosslinked polymer is a polymer formed by curing a curable coating composition that includes a) at least one monomer that has exactly one polymerizable group per molecule and least one hydrocarbyl group that has at least six carbon atoms bonded directly or indirectly to the polymerizable group, b) at least one crosslinking monomer, c) one or more heat- or UV-activated free-radical initiators, and e) one or more carriers.

Description

EXAMPLE 1

[0145] A 330 gsm acrylic fabric is gravure-coated with a curable coating composition as generally described in WO 2015/127479 at a coating weight of 5-6 gsm. The coated fabric is positioned between a textured template and a deformable foamed elastomer surface. The textured template produces about 2 truncated square pyramidal projections per square centimeter. The height of the projections is 0.5 mm. The projections are arranged in a square array. The coating is applied under an applied atmospheric pressure of about 100 kPa. Curing is performed under a nitrogen atmosphere in a 140 C. oven. Then, a second coating composition as generally described in WO 2015/127479, having a lower proportion of cross-linking monomer, is applied to the fabric, at a coating weight of 7-8 gsm. The fabric with second applied coating is subjected to an applied atmospheric pressure of 17 atmospheres and cured under this pressure at 90 C. The resulting textured fabric is designated Example 1. It has an air permeability substantially unchanged from that of the untreated fabric. The fabric sheds water well and is suitable for awnings and boat covers. During rain exposure, the textured surface is seen to break up large water droplets, resulting in a higher Bundesmann rating, using the ISO 9865 performance metrics. The improvement in ISO 9865 rating is about 1 point higher on the 5 point ISO scale. The raised projections are permanently locked into the fabric and exhibit flexibility and also return to the same textured shape after being tensioned.

EXAMPLES 2 and 3

[0146] A 50 gsm lightweight rip stop nylon fabric is chemically treated in the same way as Example 1 but is cured against a heated sawtooth 3-dimensional shape having triangular, parallel ridges separated by 0.8 cm (1.2/cm frequency) and having a height of 2 mm.

[0147] Comparative Sample A is prepared in the same manner, except the fabric is not textured during the curing operation. This results in a traditionally flat and DWR-treated substrate.

[0148] Example 3 is made in the same way as Example 2, except the fabric is a 15 dernier X 15 dernier nylon fabric having a weight of about 28 gsm. The air permeability of the untreated fabric is about 80 cubic feet/minute per ASTM D737, which is not changed significantly after coating and texturing.

[0149] Comparative Sample B is made in the same way as Example 3 but is not textured and so is flat, but is also treated with the same DWR coating

[0150] The water repellency of each of Examples 2-3 and Comparative Samples A and B are evaluated using a Bundesmann rain shower test (also known as ISO 9865 test method). Results (rating, % water weight gained and water penetration through the sample) are as indicated in the following table. Significantly less water penetration through the fabric is seen for the textured samples.

TABLE-US-00001 TABLE % Water Water Fabric Air Flow ISO 9865 Weight penetration Designation Type Textured? (scfm) Rating gained (mL) Comp. A* Ripstop No 38 4.7 7.95 37 Nylon Ex. 2 Ripstop Yes 38 4.4 18.55 6 Nylon Comp. B* 15D 15D No 80 4.8 3.68 35 Nylon Ex. 3 15D 15D Yes 80 4.6 8.94 17 Nylon

EXAMPLE 4

[0151] A 50 gsm woven polyester fabric with an air permeability of 10 scfm as measured by ASTM D737 is treated as generally described in WO 2015/127479 at a coating weight of 5-6 gsm to have a textured, 3-dimensional surface consisting of an array of triangular ridges separated by 0.8 cm and with a height of 2 mm. This textured fabric is next coated with a second curable monomeric coating having lesser amounts of crosslinking agents, also as generally described in WO 2015/127479, with an additional coating weight of 5-6 gsm. This textured face fabric is combined with an insulating spacer consisting of 2 mm thick high air permeability polypropylene webbing that is placed in between the textured face fabric and a second, flat fabric treated for high water repellency, also as described in WO 2015/127479. The composite of these three structures is clamped onto the test cups of a Bundesmann ISO 9865 water repellency tester and is exposed to a continuous, heavy rain test for 30 minutes. No water penetrates through the composite structure, even though the air permeability of the composite structure is 5 cfm (ASTM D737). This demonstrates a rain-proof, breathable structure that has about 20 more air permeability than a comparative composite membrane fabric.

[0152] In specific embodiments, the invention is:

[0153] 1. A textured fabric coated with a crosslinked, flexible polymeric coating, the textured fabric being characterized in having an air permeability of at least 0.1 scfm (0.0472 l/s) as measured according to ASTM D737, wherein the textured fabric has at least one three-dimensional surface characterized by having raised projections separated by depressed areas wherein the raised projections have a pitch of 0.25 to 10 mm and a height of about 0.3 to 8 mm above the height of the depressed areas, and wherein the crosslinked, flexible polymeric coating locks the three-dimensional surface into the textured fabric.

[0154] 2. The textured fabric of embodiment 1 wherein the raised projections have an aspect ratio of 1 to 5 and the three-dimensional surface has 1.2 to 1600 raised projections per square centimeter.

[0155] 3. The textured fabric of embodiment 1 or 2 wherein the three-dimensional surface includes 4 to 400 raised projections per square centimeter.

[0156] 4. The textured fabric of embodiment 2 or 3 wherein the three-dimensional surface includes 10 to 225 raised projections per square centimeter.

[0157] 5. The textured fabric of any preceding embodiment wherein the raised projections have a height of 0.5 to 5 mm above the height of the depressed areas.

[0158] 6. The textured fabric of any preceding embodiment wherein the raised projections have a height of 1 to 3.5 mm above the height of the depressed areas.

[0159] 7. The textured fabric of any preceding embodiment wherein the raised projections have a conical, truncated conical, pyramidal or truncated pyramidal shape.

[0160] 8. The textured fabric of any preceding embodiment wherein the raised projections are arranged in a regular two-dimensional array.

[0161] 9. The textured fabric of any preceding embodiment wherein multiple depressed areas are contiguous and form a channel through which a fluid can flow.

[0162] 10. The textured fabric of embodiment 1 wherein the raised projections have an aspect ratio of greater than 5.

[0163] 11. The textured fabric of embodiment 10 wherein the raised projections span the fabric in at least one dimension.

[0164] 12. The textured fabric of embodiment 11 wherein the depressed areas form channels through which a fluid can flow.

[0165] 13. The textured fabric of any preceding embodiment which has an air permeability of at least 2 scfm (standard cubic feet per minute) (4.72 l/s) as measured by ASTM D737, using a SDL Atlas M021A instrument and a 20 cm.sup.2 test area.

[0166] 14. The textured fabric of any preceding embodiment wherein a durable, water-repellency finish results from the polymeric coating and the coated fabric has a rating of at least 90 on the AATCC Test Method 22 (Water Repellency Spray Test):

[0167] 15. The textured fabric of any preceding embodiment which has a moisture transmission rate of 5000 to 500,000 g/m.sup.2/24 hour, as measured according to JISL 1099B1.

[0168] 16. The textured fabric of any preceding embodiment which exhibits an air permeability of at least 5 scfm (standard cubic feet per minute) as measured by ASTM D737, using a SDL Atlas M021A instrument and a 20 cm.sup.2 test area.

[0169] 17. The textured fabric of any preceding embodiment which exhibits untreated moisture transmission rate of at least 10,000 g/sq meter/24 hours as measured according to JISL 1099B1.

[0170] 18. The textured fabric of any preceding embodiment which has a weight of 20-200 gsm (grams per square meter).

[0171] 19. The textured fabric of any preceding embodiment which has a thickness of at most 2 mm.

[0172] 20. The textured fabric of any preceding embodiment wherein the flexible, crosslinked polymer has a weight of at least 10 grams per square meter.

[0173] 21. The textured fabric of any preceding embodiment wherein the flexible, crosslinked polymer has a weight of 2 to 25 grams per square meter.

[0174] 22. The textured fabric of any preceding embodiment wherein the flexible, crosslinked polymer is hydrophobic.

[0175] 23. The textured fabric of any preceding embodiment wherein the raised projection forms a logo or graphic image.

[0176] 24. The textured fabric of any preceding embodiment wherein the flexible, crosslinked polymer is a polymer of a) at least one monomer that has exactly one polymerizable group per molecule and least one hydrocarbyl group that has at least six carbon atoms bonded directly or indirectly to the polymerizable group and b) at least one crosslinking monomer.

[0177] 25. The textured fabric of any preceding embodiment wherein the flexible, crosslinked polymer is a polymer formed by curing a curable coating composition that includes

[0178] a) at least one monomer that has exactly one polymerizable group per molecule and least one hydrocarbyl group that has at least six carbon atoms bonded directly or indirectly to the polymerizable group, b) at least one crosslinking monomer, c) one or more heat- or UV-activated free-radical initiators, and e) one or more carriers.

[0179] 26. A multilayer fabric structure having a first layer which is a textured fabric of any of embodiments 1-25 and at least one additional layer.

[0180] 27. The multilayer fabric structure of embodiment 26 wherein said additional layer is a fabric treated with a water-repellant treatment.

[0181] 28. The multilayer fabric structure of embodiment 27 further comprising at least one spacing fabric layer between the face layer and the layer of the non-textured fabric is a microporous membrane.

[0182] 29. A method for producing a textured fabric of any of preceding embodiment, comprising

[0183] a) contacting an impregnated untextured starting fabric against a textured template to form a three-dimensional shape on the impregnated starting fabric, which three-dimensional shape includes raised projections, separated by depressed areas and wherein the raised projections have a pitch of 0.25 to 10 mm and a height of about 0.3 to 8 mm above the height of the depressed areas, wherein

[0184] i) the starting untextured fabric prior to impregnation has an untreated air permeability of at least 0.1 scfm as measured by ASTM D737; and

[0185] ii) the starting untextured fabric is impregnated with a curable coating composition that is applied to at least one surface of the starting fabric, wherein the curable coating composition 1) at 22 C. and at atmospheric pressure is a liquid or a suspension of one or more solids in a liquid phase and 2) is curable to form a crosslinked, hydrophobic flexible polymer;

[0186] b) at least partially curing the curable coating composition while the impregnated fabric is in contact with the template to form a crosslinked, flexible polymeric coating and lock the three-dimensional surface into the fabric to produce a textured fabric; and then

[0187] c) removing the resulting textured fabric with the three-dimensional surface from the template;

[0188] wherein the textured fabric having the three-dimensional surface has an air permeability of at least 0.1 scfm as measured according to ASTM D737 and a rating of at least 90 on the AATCC Test Method 22 (Water Repellency Spray Test).

[0189] 30. The process of embodiment 29 wherein the at least partial curing is performed in an oxygen-deficient environment.

[0190] 31. The process of embodiment 29 or 30 wherein the at least partial curing includes a free-radical polymerization step.

[0191] 32. The process of embodiment 30 wherein the free-radical polymerization step is at least partially thermally induced or plasma-induced, or both.

[0192] 33. The process of embodiment 30 wherein curable coating composition is forced into the fabric under force of applied superatmospheric pressure and is then cured.

[0193] 34. The process of any of embodiments 29-33 wherein the step of applying the curable coating composition to the fabric and the curing step are performed under an atmospheric pressure of no more than 1.5 atmospheres.

[0194] 35. The process of any of embodiments 29-34 further comprising, after step c), applying a second curable coating composition to the textured textile and curing the second curable coating composition on the textured textile.

[0195] 36. The process of embodiment 35 wherein the second curable coating composition produces upon curing a hydrophobic coating.

[0196] 37. The process of embodiment 35 or 36 wherein the second curable coating composition is forced into the fabric under force of applied superatmospheric pressure and is then cured.

[0197] 38. A method for producing a textured fabric of any of embodiments 1-25, comprising

[0198] a) providing a starting untextured fabric having an untreated air permeability of at least 0.1 scfm as measured by ASTM D737;

[0199] b) applying a curable coating composition to at least one surface of the starting fabric to form an impregnated fabric, wherein the curable coating composition 1) at 22 C. and at atmospheric pressure is a liquid or a suspension of one or more solids in a liquid phase and 2) is curable to form a crosslinked, hydrophobic flexible polymer;

[0200] c) contacting the impregnated fabric against a textured template to form a three-dimensional surface on the impregnated fabric, which three-dimensional surface includes raised projections separated by depressed areas wherein the raised projections have a pitch of 0.25 to 10 mm and a height of about 0.3 to 8 mm above the height of the depressed areas; then

[0201] d) at least partially curing the curable coating composition while the impregnated fabric is in contact with the template to form a crosslinked, flexible polymeric coating and lock the three-dimensional surface into the fabric to form the textured fabric; and then

[0202] e) removing the textured fabric from the template,

[0203] wherein the textured fabric has an air permeability of at least 0.1 scfm as measured according to ASTM D737 and a rating of at least 90 on the AATCC Test Method 22 (Water Repellency Spray Test).

[0204] 39. The method of any of embodiments 29-38 wherein step d) is performed by heating the impregnated fabric to a temperature of 100 to 180 C.

[0205] 40. A textured garment including a fabric of any of embodiments 1-25 on at least one exterior surface thereof.

[0206] 41. The textured garment of embodiment 40 wherein the projections of the three-dimensional surface form a fish-scale pattern.

[0207] 42. The textured garment of embodiment 40 wherein the projections of the three-dimensional surface form a 2-dimensional linear array.

[0208] 43. The textured garment of embodiment 40 wherein the depressed areas form a 1-dimensional array of channels through which a liquid can flow.

[0209] 44. The textured garment of any of embodiments 40-43 that is an outerwear jacket.