Poly(trimethylene terephthalate) fibers useful in high-UV exposure end uses
View Patent ↗Dyed poly(trimethylene terephthalate) fibers having a lightfastness of 4 or higher after approximately 480 kJ incident UV radiation, and processes for preparing the fibers, are provided. The fibers are useful in automotive applications and other uses wherein UV absorption is likely.
1. A process for making a dyed poly (trimethylene terepthalate) comprising:
a. providing a poly(trimethylene terephthalate) fiber,
b. combining at room temperature in an aqueous medium about 0.50 weight percent of an alcohol ethoxylate surfactant, about 0.25 weight percent of a sequestering agent, 3.00 weight percent of a benzotriazine derivative UV absorber, 0.5 weight percent of a disperse dye, and sufficient water to provide a water:fiber ratio from about 2:1 to about 40:1, all weight percents on weight of fiber, to form a dyebath;
c. adjusting the pH of the dyebath to about 4.0 to about 5.0;
d. combining the fiber and dyebath at room temperature;
e. heating the dyebath at a rate of at least about 1° C. per minute to a temperature of 132–145° C.;
f. maintaining the dyebath temperature for at least about 30 minutes to produce a dyed poly(trimethylene terephthalate) fiber;
g. allowing the dye bath to cool; and
h. rinsing the dyed poly(trimethylene terephthalate) fiber.
2. The process of claim 1 wherein the disperse dye is selected from CI Disperse Red 86, CI Disperse Red 91, CI Disperse Red 161, CI Disperse Red 279, CI Disperse Yellow 42, CI Disperse Yellow 96, CI Disperse Yellow 160, CI Disperse Blue 27, CI Disperse Blue 60, and CI Disperse Blue 77.
3. The process of claim 1 wherein the dyed fiber has a lightfastness of 4 or higher after exposure to at least 448 kJ incident UV radiation.
4. The process of claim 1 wherein the disperse dye is selected from CI Disperse Red 86, CI Disperse Red 161, CI Disperse Yellow 42, CI Disperse Yellow 96, CI Disperse Yellow 160, CI Disperse Blue 200, CI Disperse Blue 60 and CI Disperse Blue 77.
5. The process of claim 4 wherein the dyed fiber has a lightfastness of 4 or higher after exposure to at least 779 IC incident UV radiation.
6. The process of claim 1 wherein the dyebath is heated to a temperature of about 132° C.
7. The process of claim 1 wherein the pH is from about 4.25 to about 4.7.
8. The process of claim 1 wherein the pH is about 4.5.
9. The process of claim 1 wherein the dyebath is heated at a rate of about 2° C. per minute.
10. The process of claim 1 wherein the fiber has an intrinsic viscosity of at least about 0.70 dl/g.
11. The process of claim 1 wherein the fiber has an intrinsic viscosity of at least about 0.80 dl/g.
12. The process of claim 1 wherein the fiber has an intrinsic viscosity of at least about 0.90 dl/g.
13. The process of claim 1 wherein the fiber has an intrinsic viscosity of at least about 1.0 dl/g.
14. The process of claim 1 wherein the fiber has an intrinsic viscosity of about 2.0 dl/g or less.
15. The process of claim 1 wherein the fiber has an intrinsic viscosity of about 1.5 dl/g or less.
16. The process of claim 1 wherein the fiber has an intrinsic viscosity of about 1.2 dl/g or less.
17. The process of claim 1 wherein the fiber has a lightfastness of 4 to 5 after exposure to at least 488 kJ incident UV radiation.
18. The process of claim 1 wherein the fiber has an initial tenacity, and wherein said initial tenacity declines by about 10% or less after exposure to at least 481 kJ incident UV radiation.