NYLON CARPET FIBERS HAVING BLEACH RESISTANCE
The present invention relates to a nylon yarn of a finely dispersed melt blended polymer alloy having i) a polyamide component selected from polyhexamethyleneadipamide, polycaprolactam and mixtures thereof, and ii) a nylon 11 component; wherein the polyamide component is the major component by weight of the total melt blended polymer and wherein the polyamide component has a viscosity of about 2.6 IV or more as measured in 96% sulfuric acid. The resulting nylon yarn shows improved bleach resistance. The present invention also relates to processes of producing the yarn and nylon carpets comprising the yarn described above.
1 . A nylon yarn comprising a finely dispersed melt blended polymer alloy comprising i) a polyamide component selected from the group consisting of polyhexamethyleneadipamide, polycaprolactam and mixtures thereof, and ii) a nylon 11 component; wherein the polyamide component is the major component by weight of the total melt blended polymer alloy and wherein the polyamide component has a viscosity of about 2.6 IV or more as measured in 96% sulfuric acid.
2 . The nylon yarn of claim 1 , wherein the nylon 11 component is dispersed in separately detectable regions that are enclosed by, but not dissolved in, the polyamide component.
3 . The yarn of claim 1 wherein the nylon 11 component is present at a concentration in the range of about 2 percent by weight to about 35 percent by weight of the total melt blended polymer alloy.
4 . The yarn of claim 1 wherein the nylon 11 component is present at a concentration in the range of about 5 percent by weight to about 20 percent by weight of the total melt blended polymer alloy.
5 . The yarn of claim 1 , wherein dyed knit socks made from said yarn have at least a positive 0.5 unit difference in gray scale rating when exposed to bleach for 4 hours when compared to dyed knit socks made from yarn containing only the polyamide component.
6 . The yarn of claim 1 wherein the melt blended polymer alloy has a crystallization energy of about 90% or more of the crystallization energy of the polyamide component.
7 . The yarn of claim 1 further comprising a dye.
8 . The yarn of claim 7 wherein the dye is an acid dye.
9 . The yarn of claim 7 wherein the dye is a disperse dye.
10 . The yarn of claim 1 further comprising a pigment.
11 . The yarn of claim 10 wherein the pigment is an organic pigment.
12 . A process for producing a nylon yarn comprising:
i) melt blending in an extrusion process consisting of either a twin screw or a single screw extruder with a mixing head, a polyamide component selected from the group consisting of polycaprolactam, polyhexamethyleneadipamide and mixtures thereof, with a nylon 11 component to form a finely dispersed melt blended polymer alloy,
ii) extruding the melt blended polymer alloy through a spinneret to form filaments, and
iii) converging the filaments into a yarn and winding the yarn; wherein the polyamide component comprises at least about 65% by weight of the melt blended polymer alloy; wherein the polyamide component has a viscosity of about 2.6 IV or more as measured in 96% sulfuric acid, and further wherein the nylon 11 component remains in separately detectable regions of the yarn, enclosed by, but not dissolved in, the polyamide component
13 . The process of claim 12 , wherein the melt blended polymer alloy further comprises an organic pigment.
14 . The process of claim 12 further comprising drawing and bulk-texturing the yarn.
15 . The process of claim 12 , further comprising dyeing the yarn.
16 . The process of claim 15 wherein the dye is an acid dye.
17 . The process of claim 15 wherein the dye is a disperse dye.
18 . A process for producing a bleach resistant nylon carpet comprising:
i) melt mixing a polyamide component selected from the group consisting of polycaprolactam, polyhexamethyleneadipamide, and mixtures thereof, with a nylon 11 component to form a finely dispersed melt blended polymer alloy,
ii) extruding the melt blended polymer alloy through a spinneret to form filaments,
iii) converging the filaments into a yarn,
iv) drawing the yarn,
v) bulk texturing,
vi) winding the yarn,
vii) tufting the yarn into a carpet, and
viii) optionally dyeing the carpet; wherein the polyamide component has a viscosity of about 2.6 IV or more as measured in 96% sulfuric acid; and further wherein the nylon 11 component of the yarn is dispersed in separately detectable regions that are enclosed by, but not dissolved in, the polyamide component.
19 . The process of claim 18 , wherein the melt blended polymer alloy further comprises an organic pigment.
20 . The process of claim 18 , wherein the carpet is dyed with an acid dye.
21 . The process of claim 18 further comprising the step of treating the carpet with a stain resistant chemical.
22 . The process of claim 18 further comprising the step of treating the carpet with a soil resistant chemical.
23 . A bleach resistant nylon carpet comprising:
i) a polyamide yarn comprising a finely dispersed melt blend polymer alloy comprising a polyamide component selected from polycaprolactam, polyhexamethyleneadipamide, and mixtures thereof, and a nylon 11 component, and
ii) carpet backing, wherein the polyamide component has a viscosity of about 2.6 IV or more as measured in 96% sulfuric acid; and further wherein the nylon 11 component is dispersed in separately detectable regions that are enclosed by, but not dissolved in, the polyamide component.
24 . The nylon carpet of claim 23 further comprising a dye.
25 . The nylon carpet of claim 24 wherein the dye is an acid dye.
26 . The nylon carpet of claim 24 wherein the dye is a disperse dye.
27 . The nylon carpet of claim 23 further comprising a pigment.
28 . The nylon carpet of claim 27 wherein the pigment is an organic pigment.
29 . The nylon carpet of claim 23 , wherein the nylon yarn, having an original pile height, recovers more than 50% of the original pile height immediately after a 10-day crush test at 50 psi.
30 . The nylon carpet of claim 23 , wherein the nylon yarn, having an original pile height, recovers more than 89% of the original pile height within 24 hours following a 10-day crush test at 50 psi.
31 . A process for producing a pigmented, bleach resistant nylon carpet comprising:
i) melt mixing a polyamide component selected from the group consisting of polycaprolactam, polyhexamethyleneadipamide, and mixtures thereof, with a nylon 11 component and a minor pigmented polymer component, to form a finely dispersed melt blended polymer alloy,
ii) extruding the melt blended polymer alloy through a spinneret to form filaments,
iii) converging the filaments into a yarn,
iv) drawing the yarn,
v) bulk texturing,
vi) winding the yarn,
vii) tufting the yarn into a carpet, and
viii) optionally dyeing the carpet; wherein the polyamide component has a viscosity of about 2.6 IV or more as measured in 96% sulfuric acid; and further wherein the nylon 11 component of the yarn is dispersed in separately detectable regions that are enclosed by, but not dissolved in, the polyamide component.