Airbag fabrics

Abstract

A woven fabric comprising spun synthetic polyamide yarn woven in the warp direction and weft direction wherein the polyamide yarn in the woven fabric exhibits a formic acid relative viscosity of at least 60, a halide:copper molar ratio of at least 2.0 and a sodium content of no more than 25 ppm, and wherein the woven fabric exhibits a melt-through resistance at 450° C. of least 2.10 seconds. The invention also provides an airbag made the woven fabric, as well as a method of making the same.

1 . A woven fabric comprising spun synthetic polyamide yarn woven in the warp direction and weft direction wherein the polyamide yarn in the woven fabric exhibits a formic acid relative viscosity of at least 60, a halide:copper molar ratio of at least 2.0 and a sodium content of no more than 25 ppm, and wherein the woven fabric exhibits a melt-through resistance at 450° C. of least 2.10 seconds. 
     
     
         2 . A woven fabric according to  claim 1  wherein said relative viscosity is at least 70, preferably at least 78, preferably at least 85, preferably at least 90. 
     
     
         3 . A woven fabric according to  claim 1  wherein the polyamide yarn comprises copper bromide or iodide. 
     
     
         4 . A woven fabric according to  claim 1  wherein the molar ratio of halide:copper in said polyamide yarn of the woven fabric is at least 4.0:1, preferably at least 6.0:1. 
     
     
         5 . A woven fabric according to  claim 1  wherein said polyamide yarn exhibits a copper content of 60 to 120 ppm calculated as elemental copper by total weight of the polyamide yarn in the woven fabric. 
     
     
         6 . A woven fabric according to  claim 1  wherein said polyamide yarn exhibits a sodium content of no more than 20 ppm, preferably no more than 15 ppm, preferably no more 10 ppm. 
     
     
         7 . A woven fabric according to  claim 1  wherein the polyamide yarn from which the woven fabric is made exhibits a halide:copper molar ratio of at least 4.0:1, preferably at least 8.0:1, preferably at least 10.0:1, preferably at least 12.0:1. 
     
     
         8 . A woven fabric according to  claim 1  wherein the polyamide yarn from which the woven fabric is made further comprises a halide salt other than copper halide or sodium halide, preferably potassium bromide or iodide. 
     
     
         9 . A woven fabric according to  claim 1  wherein the yarn in the warp and weft directions is yarn having a tenacity from 6.8 to 10.1 g/den. 
     
     
         10 . A woven fabric according to  claim 1  which exhibits a melt through resistance at 450° C. of at least 2.20, preferably at least 2.30, preferably at least 2.40, preferably at least 2.50 seconds. 
     
     
         11 . A woven fabric according to  claim 1  which has a total fabric weight of from 50 to 500 g/m 2 , preferably no more than 300 g/m 2 , preferably no more than 260 g/m 2 , preferably no more than 225 g/m 2 , preferably in the range of 170 to 225 g/m 2 , and preferably no more than 220 g/m 2 , preferably no more than 210 g/m 2 . 
     
     
         12 . A woven fabric according to  claim 1  wherein said yarn has from 90 to 300 ends/dm, or from 160 to 240 ends/dm. 
     
     
         13 . A woven fabric according to  claim 1  wherein said polyamide is nylon-6,6. 
     
     
         14 . A woven fabric according to  claim 1  wherein said yarn has a linear mass density in the range of from 150 to 940 decitex, or in the range of 150 to 750 decitex. 
     
     
         15 . A woven fabric according to  claim 1  which has a total thickness of no more than 0.40 mm. 
     
     
         16 . A woven fabric according to  claim 1  wherein the tear strength of the fabric in both the warp and weft directions is at least 120 N, preferably at least 150 N, preferably at least 170 N when the fabric is unaged. 
     
     
         17 . A woven fabric according to  claim 1  preceding claim wherein said fabric exhibits a static air permeability of no more than 6.0, preferably no more than 5.0, preferably no more than 4.0 l/dm 2 /min, preferably no more than 3.0 l/dm 2 /min, preferably no more than 2.0 l/dm 2 /min. 
     
     
         18 . A woven fabric according to  claim 1  wherein said fabric exhibits a dynamic air permeability of no more than 700, preferably no more than 600, preferably no more than 500, preferably no more than 400, preferably no more than 300, preferably no more than 200 mm/s. 
     
     
         19 . (canceled) 
     
     
         20 . A woven fabric according to  claim 1  wherein the fabric density is no more than 750 kg/m 3 . 
     
     
         21 . An article, preferably an airbag, made from the woven fabric of  claim 1 . 
     
     
         22 - 27  (canceled)