Conjugate fiber and method of producing same
View Patent ↗A poly(trimethylene terephthalate)-based conjugate fiber characterized in that the fiber is composed of single filaments which are combined with two polyester components in a side-by-side manner or an eccentric sheath-core manner, that at least one of the two polyester components forming the single filaments is a poly(trimethylene terephthalate), and that the fiber satisfies the following conditions: (1) the stretch elongation of crimp manifested prior to boiling water treatment is 20% or less; (2) the breaking elongation is from 25 to 100%; and (3) the maximum stress value of a dry heat shrinkage stress is from 0.01 to 0.24 cN/dtex.
1. A conjugate fiber characterized in that the fiber is composed of single filaments which are combined with two polyester components in a side-by-side manner or an eccentric sheath-core manner, that at least one of the two polyester components forming the single filaments is a poly(trimethylene terephthalate), and that the fiber satisfies the following conditions (1) to (3):
(1) the stretch elongation of crimp manifested prior to boiling water treatment is 20% or less;
(2) the breaking elongation is from 25 to 100%; and
(3) the maximum stress value of a dry heat shrinkage stress is from 0.01 to 0.24 cN/dtex.
2. The conjugate fiber according to claim 1 , wherein the starting temperature of manifestation of a dry heat shrinkage stress is from 50 to 80° C.
3. The conjugate fiber according to claim 1 , wherein the breaking elongation is from 45 to 100%.
4. The conjugate fiber according to claim 1 , wherein the stretch elongation of crimp manifested prior to the boiling water treatment is 10% or less.
5. The conjugate fiber according to claim 1 , wherein the stretch elongation after boiling water treatment under a load of 3.5×10 −3 cN/dtex (CE 3.5 ) is from 12 to 30%.
6. The conjugate fiber according to claim 1 , wherein the maximum stress value of a dry heat shrinkage stress of the conjugate fiber is from 0.05 to 0.24 cN/dtex, and the breaking elongation is from 30 to 55%.
7. The conjugate fiber according to claim 1 , wherein the maximum stress value of a dry heat shrinkage stress of the conjugate fiber is from 0.02 to 0.15 cN/dtex.
8. The conjugate fiber according to claim 1 , wherein a stress value at 10% elongation in an elongation-stress measurement of the conjugate fiber shows a difference between a maximum value and a minimum value along a yarn length direction of 0.30 cN/dtex or less.
9. The conjugate fiber according to claim 1 , wherein a number of interlacing is from 2 to 50/m.
10. The conjugate fiber according to claim 1 , wherein the two polyester components forming the single filaments are both poly(trimethylene terephthalate).
11. The conjugate fiber according to claim 1 , wherein the other one of the two polyester components forming the single filaments is a poly(butylene terephthalate) or a poly(ethylene terephthalate).
12. The conjugate fiber according to claim 1 , wherein the other one of the two polyester components forming the single filaments is a poly(trimethylene terephthalate) or a poly(butylene terephthalate), and the maximum temperature T max of a loss tangent obtained by the dynamic viscoelasticity measurement is from 80 to 98° C.
13. The conjugate fiber according to claim 1 , wherein the other one of the two polyester components forming the single filaments is a poly(ethylene terephthalate), and the half-value width of the maximum temperature T max of a loss tangent obtained by the dynamic viscoelasticity measurement is from 25 to 50° C.
14. The conjugate fiber according to claim 1 , wherein the fiber is produced by a direct spin-draw process, and the fiber is wound in a package shape.