Crimped Yarn, Method for Manufacture thereof, and Fiber Structure

Abstract

A crimped yarn includes a synthetic fiber which contains an aliphatic polyester resin (A) and a thermoplastic polyamide resin (B) and exposed area ratio of the aliphatic polyester resin (A) with respect to fiber surface area is 5% or less and a crimp is imparted to a multifilament comprising said synthetic fiber, and a fiber structure containing said crimped yarn as at least a part thereof. Furthermore, a crimped yarn in which the aliphatic polyester resin (A) and the thermoplastic polyamide resin (B) are constituted of a polymer alloy type synthetic fiber, or a crimped yarn constituted by a sheath/core type composite fiber in which the core component comprises the aliphatic polyester resin (A) or a polymer alloy of the aliphatic polyester resin (A) and the thermoplastic polyamide resin (B) and the sheath component comprises the thermoplastic polyamide resin (B), and a fiber structure containing said crimped yarn as at least a part thereof.

1 - 33 . (canceled) 
   
   
       34 . A crimped yarn comprising a synthetic fiber comprising an aliphatic polyester resin (A) and a thermoplastic polyamide resin (B), wherein substantially no aliphatic polyester resin (A) is exposed on a surface of the fiber, and a crimp is imparted to a multifilament comprising said synthetic fiber. 
   
   
       35 . The crimped yarn according to  claim 34 , wherein the synthetic fiber has an exposed area ratio of the aliphatic polyester resin (A) with respect to fiber surface area of 5% or less. 
   
   
       36 . The crimped yarn according to  claim 34 , which is a BCF yarn. 
   
   
       37 . The crimped yarn according to  claim 34 , which is a crimped yarn constituted of a polymer alloy type synthetic fiber containing the aliphatic polyester resin (A) and the thermoplastic polyamide resin (B), and has an sea/island structure in which the aliphatic polyester resin (A) forms an island component and the thermoplastic polyamide resin (B) forms a sea component and wherein the island component has a domain size of 0.001 to 2 μm. 
   
   
       38 . The crimped yarn according to  claim 37 , wherein the aliphatic polyester resin (A) is a crystalline resin and has a melting point of 150 to 230° C. 
   
   
       39 . The crimped yarn according to  claim 37 , wherein the thermoplastic polyamide resin (B) is a crystalline resin and has a melting point of 150 to 250° C. 
   
   
       40 . The crimped yarn according to  claim 37 , wherein the aliphatic polyester resin (A) and the thermoplastic polyamide resin (B) have a blend ratio (weight ratio) of 5/95 to 55/45. 
   
   
       41 . The crimped yarn according to  claim 34 , wherein a polymer alloy containing the aliphatic polyester resin (A) and the thermoplastic polyamide resin (B) further comprises compound (C) containing two or more active hydrogen reactive groups in a molecule. 
   
   
       42 . The crimped yarn according to  claim 41 , wherein the active hydrogen reactive group is at least one selected from the group consisting of glycidyl group, oxazoline group, carbodiimide group and acid anhydride group. 
   
   
       43 . The crimped yarn according to  claim 41 , containing 0.005 to 5 wt % of the compound (C) with respect to the total amount of the aliphatic polyester resin (A), the thermoplastic polyamide resin (B) and the compound (C). 
   
   
       44 . The crimped yarn according to  claim 37 , further comprising grooves extending in a fiber axis direction formed on at least a portion of a surface of the synthetic fiber and a width of said groove(s) is(are) 0.01 to 1 μm. 
   
   
       45 . The crimped yarn according to  claim 44 , wherein an aspect ratio of the groove (longitudinal axis length of groove/width of groove) is 10 to 500. 
   
   
       46 . The crimped yarn according to  claim 37 , wherein the crimped yarn satisfies the following physical properties:
 Strength: 1 cN/dtex or more   Crimp elongation percentage after boiling water treatment: 3 to 30%   Non-circularity (D 1 /D 2 ): 1.2 to 7.   
   
   
       47 . The crimped yarn according to  claim 37 , further comprising 0.01 to 2 wt % of at least one kind crystal nucleating agent selected from the group consisting of talc, a sorbitol derivative, a metal salt of phosphoric acid ester, a basic inorganic aluminum compound and a salt of melamine compound with respect to the aliphatic polyester resin (A). 
   
   
       48 . A method of producing a crimped yarn comprising:
 kneading an aliphatic polyester resin (A) and a thermoplastic polyamide resin (B) in a blend ratio (weight ratio) of 5/95 to 55/45 such that a ratio of melt viscosity (ηb/ηa) (wherein, ηa: melt viscosity of the aliphatic polyester resin (A), ηb: melt viscosity of the thermoplastic polyamide resin (B)) is in the range of 0.1 to 2;   melt spinning the resin at a spinning temperature of, provided that the melting point of the thermoplastic polyamide resin (B) is Tmb, Tmb+3° C. to Tmb+40° C., to thereby form a multifilament at a linear discharge velocity in a spinning hole of a spinneret of 0.02 to 0.4 m/sec;   cooling the multifilament by setting a starting point of cooling substantially vertically beneath 0.01 to 0.15 m from a surface of the spinneret and applying a gas to the filament from substantially a right angle at a velocity of 0.3 to 1 m/sec and at a temperature of 15 to 25° C.;   covering the multifilament with a finishing agent for spinning;   stretching the filament in 1 to 3 stages while heating the filament with hot rolls of 50 to 130° C. such that an elongation at break of the multifilament is 15 to 65%;   heat setting the filament by setting a final roll temperature after stretching at such that a melting point of the aliphatic polyester resin (A) is Tma, Tma−30 to Tma+30° C.;   feeding the filament to an air-jet stuffing machine and subjecting the filament to crimp processing by setting a nozzle temperature of said machine to 5 to 100° C. higher than a final roll after stretching, to thereby form a 3-dimensionally crimped yarn, and   contacting the crimped yarn with a cooling drum and winding the crimped yarn at a speed 10 to 30% lower than that of the final roll after stretching.   
   
   
       49 . The method according to  claim 48 , further comprising adding a compound (C) containing two or more active hydrogen reactive groups in a molecule to the aliphatic polyester resin (A) and/or the thermoplastic polyamide resin (B) as a compatibilizer, melting the resulting mixture and kneading the resulting melted mixture. 
   
   
       50 . The method according to  claim 48 , wherein the compound (C) is added in an amount of 0.005 to 5 wt % with respect to the total amount of the aliphatic polyester resin (A), the thermoplastic polyamide resin (B) and the compound (C). 
   
   
       51 . The method according to  claim 48 , further comprising adding at least one kind crystal nucleating agent selected from the group consisting of talc, a sorbitol derivative, a metal salt of phosphoric acid ester, a basic inorganic aluminum compound, a salt of melamine compound to the aliphatic polyester resin (A) and/or the thermoplastic polyamide resin (B) and melt kneading the resulting mixture. 
   
   
       52 . The method according to  claim 51 , adding 0.01 to 2 wt % of at least one kind crystal nucleating agent selected from the group consisting of talc, a sorbitol derivative, a metal salt of phosphoric acid ester, a basic inorganic aluminum compound and a salt of melamine compound with respect to the aliphatic polyester resin (A) to the mixture. 
   
   
       53 . The crimped yarn according to  claim 34 , wherein the crimped yarn comprises a sheath/core type composite fiber of which a core component comprises the aliphatic polyester resin (A) or a polymer alloy of the aliphatic polyester resin (A) and the thermoplastic polyamide resin (B) and a sheath component comprise the thermoplastic polyamide resin (B), and the following physical properties (1) to (3) are satisfied:
 (1) Strength: 1.5 to 3 cN/dtex.   2) Single fiber thickness: 5 to 40 dtex.   3) Boiling water shrinkage: 6% or less.   
   
   
       54 . The crimped yarn according to  claim 53 , wherein a total heat capacity of melting peak of differential calorimetric curve measured for the crimped yarn at a heating rate of 16° C./min is 50 J/g or more. 
   
   
       55 . The crimped yarn according to  claim 53 , wherein the composite fiber has a sheath/core ratio (weight ratio) is 10/90 to 65/35. 
   
   
       56 . The crimped yarn according to  claim 53 , wherein a non-circularity (D 3 /D 4 ) of a single fiber of the crimped yarn is 1.3 to 4. 
   
   
       57 . The crimped yarn according to  claim 53 , wherein a crimp elongation percentage after boiling water treatment of the crimped yarn is 5 to 35%. 
   
   
       58 . The crimped yarn according to  claim 53 , wherein a crimp elongation percentage measured after boiling water treatment under a load of 2 mg/dtex (elongation percentage under load) is 2 to 30%. 
   
   
       59 . The crimped yarn according to  claim 53 , wherein a blend ratio (weight ratio) of the aliphatic polyester resin (A) and the thermoplastic polyamide resin (B) of the core component is 95/5 to 20/80. 
   
   
       60 . The sheath/core type composite fiber according to  claim 59 , wherein an alloy structure of a polymer alloy of the core component satisfies the following (1) to (3):
 (1) The aliphatic polyester resin (A) forms the island component.   2) The thermoplastic polyamide resin (B) forms the sea component.   3) A diameter of the island component is 0.001 to 2 μm.   
   
   
       61 . A method of producing a crimped yarn comprising:
 joining an aliphatic polyester resin (A) as a core component and a thermoplastic polyamide resin (B) as a sheath component in a spinning hole of a spinneret;   discharging the components to thereby form a spun yarn;   stretching the spun yarn at a total stretching ratio of 2 to 5;   heat setting the spun yarn at a final roll temperature after stretching at 160 to 220° C.; and   subjecting the spun yarn to a crimp processing by an air stuffer crimp processing machine.   
   
   
       62 . A method of producing a crimped yarn comprising:
 joining an aliphatic polyester resin (A) as a core component and a thermoplastic polyamide resin (B) as a sheath component in a weight ratio of the core component of 10 to 65 wt %;   discharging the joined resin through a spinning hole of a spinneret such that a melt viscosity ratio (ηb/ηa) is in a range of 0.2 to 2;   melt spinning the joined resin at a selected spinning temperature wherein the melting point of the thermoplastic polyamide resin (B) is Tmb, Tmb to Tmb+30° C. and linear discharge velocity in the spinning hole of the spinneret is 1 to 20 m/min to thereby form a spun yarn;   cooling the spun yarn by setting a starting point of cooling vertically beneath 0.01 to 0.15 m from a surface of the spinneret and applying a gas at a wind speed 0.3 to 1 m/sec and a wind temperature of 15 to 25° C. from a right angle to a perpendicular direction to the spinneret surface to obtain a multifilament;   stretching the multifilament in 2 stages at a total stretching ratio of 2 to 5;   subjecting the multifilament to a crimp processing and adjusting a first stage stretching roll to 50 to 90° C., a second stage stretching roll to 90 to 150° C. and a final roll after stretching to 160 to 220° C. to heat set the multifilament;   subjecting the multifilament to an air jet stuffer crimp processing machine carried out by setting a nozzle temperature of the machine to a temperature 5 to 100° C. higher than the final roll temperature to thereby form a crimped yarn;   contacting the crimped yarn with a cooling drum; and   winding the crimped yarn at a speed 10 to 30% lower than the final roll after stretching.   
   
   
       63 . A method of producing a crimped yarn comprising:
 forming a core component comprising a polymer alloy obtained by melt kneading an aliphatic polyester resin (A) and a thermoplastic polyamide resin (B) as a core component with a twin screw extruding/kneading machine and/or a single screw extruding/kneading machine, in a range of kneading temperature of from a melting point of the thermoplastic polyamide resin (B), (Tmb), to Tmb+40° C., at a shear rate of 200 to 20,000 sec −1  and a residence time of 0.5 to 30 minutes, and a sheath component comprising a thermoplastic polyamide resin (B); and   joining the resins in a spinneret and discharging a composite fiber formed by the spinneret.