Antistatic ultrafine fiber and method for producing the same

Abstract

According to the present invention, there are provided a polyester ultrafine fiber excellent in durability and having an antistatic property, and a method for producing the same. Further, there are provided an antistatic polyester ultrafine fiber capable of being imparted with various functions such as ultraviolet blocking effect, cation dyeability, flame retardancy, spun-like bulkiness, soft touch and resilience of the surface, reboundability, dryness, naturalness, and spunize appearance, wool-like touch feel, wrinkle recoverability, and water absorbing/quick drying property, by introduction of a third component into the antistatic polyester ultrafine fiber, combination with other fibers, change in cross sectional shape, and the like, and a method for producing the same.

1 . An antistatic core sheath type polyester ultrafine fiber, being a core sheath type polyester composite fiber having a core part including a polyester A, and a sheath part including a copolymerized polyester B, characterized by satisfying the following requirements:
 (i) the single yarn fineness being 1.5 dtex or less;   (ii) the ratio A:B of the area A of the core part and the area B of the sheath part being within the range of 5:95 to 80:20;   (iii) the single yarn strength being 3.0 cN/dtex or more;   (iv) the friction-charged voltage of the yarn being 2000 V or less; and   (v) the polyester A being an antistatic polyester comprising, as an antistatic agent, (a) a polyoxyalkylene type polyether represented by the following general formula (1) in an amount of 0.2 to 30 parts by weight, and (b) an organic ionic compound substantially nonreactive with the polyester in an amount of 0.05 to 10 parts by weight per 100 parts by weight of an aromatic polyester;
   R 2 O—(CH 2 CH 2 O) n (R 1 O) m —R 2   (1)
 
   [where in the formula, R 1  is an alkylene group or a substituted alkylene group having two or more carbon atoms, R 2  is a hydrogen atom, a monovalent hydrocarbon group having 1 to 40 carbon atoms, a monovalent hydroxyhydrocarbon having 2 to 40 carbon atoms, or a monovalent acyl group having 2 to 40 carbon atoms, n is an integer of 1 or more, and m is an integer of 1 or more.]   
     
     
         2 . The antistatic core sheath type polyester ultrafine fiber according to  claim 1 , wherein the copolymerized polyester B is a polyester comprising an organic type ultraviolet absorbing component copolymerized therein in an amount of 0.1 to 5.0 wt % based on the total weight of the polyester. 
     
     
         3 . The antistatic core sheath type polyester ultrafine fiber according to  claim 2 , wherein the organic type ultraviolet absorbing component is a benzoxazine type organic ultraviolet absorber. 
     
     
         4 . The antistatic core sheath type polyester ultrafine fiber according to  claim 1 , wherein the copolymerized polyester B is a polyester comprising an organic sulfonic acid metal salt copolymerized therein in an amount of 1.0 to 5.0 mol % based on the total amount of acid components except for the organic sulfonic acid metal salt. 
     
     
         5 . The antistatic core sheath type polyester ultrafine fiber according to  claim 1 , wherein the copolymerized polyester B is a polyester comprising a phosphorus type flame retardant component represented by the following general formula (2) in an amount of 1,000 to 10,000 ppm in terms of phosphorus atom based on the total weight of the polyester: 
       
         
           
           
               
               
           
         
       
       [where in the formula, R 1  is hydrogen or a hydroxyalkyl group having 1 to 10 carbon atoms, R 2  is hydrogen, an alkyl group having 1 to 10 carbon atoms, or an aryl group having 6 to 24 carbon atoms, and R 3  is hydrogen, an alkyl group or a hydroxyalkyl group having 1 to 10 carbon atoms.] 
     
     
         6 . The antistatic core sheath type polyester ultrafine fiber according to  claim 1 , the core sheath type polyester composite fiber having 3 to 8 fin parts in a shape protruding outwardly from the fiber cross section central part in a cross section orthogonal to the direction of length of the single yarn, and the protrusion coefficient of the fin parts defined by the following equation being 0.3 to 0.7:
   protrusion coefficient=( a 1 −b 1)/ a 1   where a 1 : the length between the center of the inscribed circle of the inner surface wall of the cross section orthogonal to the fiber axis and the fin part top; and   b 1 : the radius of the inscribed circle of the inner surface wall of the cross section orthogonal to the fiber axis.   
     
     
         7 . The antistatic core sheath type polyester ultrafine fiber according to  claim 1 , the core sheath type polyester composite fiber having a flat shape including 3 to 6 round cross section single yarns bonded to one another in the longitudinal direction in a cross section orthogonal to the direction of length of the single yarn, and the flatness α/β expressed as the ratio of the maximum diameter α (major axis) of the flat shape and the length β of the maximum diameter (minor axis) orthogonal to the major axis being 3 to 6. 
     
     
         8 . A cloth characterized by including the antistatic core sheath type polyester ultrafine fiber according to  claim 1 . 
     
     
         9 . An antistatic polyester composite false twisted textured yarn, comprising: two kinds of polyester filament yarns different in elongation, including bundled portions each including an alternately twisted yarn-like wrapped portion and an entangled portion, and open portions, alternately formed in the longitudinal direction therein, and characterized by satisfying the following requirements (i) to (iv):
 (i) the polyester filament yarn X having a smaller elongation being a core sheath type polyester composite fiber having a core part including a polyester A, and a sheath part including a copolymerized polyester B, the polyester A comprising an antistatic polyester comprising, as an antistatic agent, (a) a polyoxyalkylene type polyether represented by the following general formula (1) in an amount of 0.2 to 30 parts by weight, and (b) an organic ionic compound substantially nonreactive with the polyester in an amount of 0.05 to 10 parts by weight per 100 parts by weight of an aromatic polyester;   (ii) the polyester filament yarn Y having a larger elongation comprising a polyester containing a matting agent in an amount of 0 to 10 wt % per 100 parts by weight of an aromatic polyester;   (iii) being in a two-layer structure in which the polyester filament yarn X forms a core part of the composite false twisted yarn, and the polyester filament yarn Y wraps around the core part in an alternately twisted yarn form to form an outer layer part (sheath part); and   (iv) the mean yarn length of the polyester filament yarn Y being larger than the mean yarn length of the polyester filament yarn X by 5 to 20%,
   R 2 O—(CH 2 CH 2 O) n (R 1 O) m —R 2   (1)
 
   [where in the formula, R 1  is an alkylene group or a substituted alkylene group having two or more carbon atoms, R 2  is a hydrogen atom, a monovalent hydrocarbon group having 1 to 40 carbon atoms, a monovalent hydroxyhydrocarbon having 2 to 40 carbon atoms, or a monovalent acyl group having 2 to 40 carbon atoms, n is an integer of 1 or more, and m is an integer of 1 or more.]   
     
     
         10 . The antistatic polyester composite false twisted textured yarn according to  claim 9 , satisfying the following conditions (i) to (v):
 (i) the friction-charged voltage of the antistatic polyester composite false twisted textured yarn being 2000 V or less;   (ii) the ratio of the core part area and the sheath part area in a cross section orthogonal to the fiber axis of the polyester yarn X being within the range of 5:95 to 80:20;   (iii) the strength of the antistatic polyester composite false twisted textured yarn being 1.5 cN/dtex or more; and   (iv) the crimp degree of the antistatic polyester composite false twisted textured yarn being 2 to 8%.   
     
     
         11 . The antistatic polyester composite false twisted textured yarn according to  claim 9 , the core sheath type polyester composite fiber having 3 to 8 fin parts in a shape protruding outwardly from the fiber cross section central part in a cross section orthogonal to the direction of length of the single yarn, and the protrusion coefficient of the fin parts defined by the following equation being 0.3 to 0.7:
   protrusion coefficient=( a 1 −b 1)/ a 1   where a 1 : the length between the center of the inscribed circle of the inner surface wall of the cross section orthogonal to the fiber axis and the fin part top; and   b 1 : the radius of the inscribed circle of the inner surface wall of the cross section orthogonal to the fiber axis.   
     
     
         12 . The antistatic polyester composite false twisted textured yarn according to  claim 9 , the core sheath type polyester composite fiber having a flat shape including 3 to 6 round cross section single yarns bonded to one another in the longitudinal direction in a cross section orthogonal to the direction of length of the single yarn, and the flatness α/β expressed as the ratio of the maximum diameter α (major axis) of the flat shape and the length β of the maximum diameter (minor axis) orthogonal to the major axis being 3 to 6. 
     
     
         13 . A cloth characterized by including the antistatic polyester composite false twisted textured yarn according to  claim 9 . 
     
     
         14 . An antistatic polyester combined filament yarn comprising an antistatic polyester filament yarn X and a polyester filament yarn Y, and characterized by satisfying the following conditions (i) to (vi):
 (i) the antistatic polyester filament yarn X being a core sheath type polyester composite fiber having a core part including a polyester A, and a sheath part including a polyester B, the polyester A comprising an antistatic polyester containing, as an antistatic agent, (a) a polyoxyalkylene type polyether represented by the following general formula (1) in an amount of 0.2 to 30 parts by weight, and (b) an organic ionic compound substantially nonreactive with the polyester in an amount of 0.05 to 10 parts by weight per 100 parts by weight of an aromatic polyester;   (ii) the single yarn fineness of the polyester filament yarn X being 1.5 dtex or less;   (iii) the friction-charged voltage of the combined filament yarn being 2000 V or less;   (iv) the combined filament yarn being the one obtained through an air entanglement step and a relaxation heat treatment step in this order;   (v) the combining ratio of the polyester filament yarn X and the polyester filament yarn Y being 8:2 to 6:4; and   (vi) the polyester filament yarn X forming an outer layer part of the combined filament yarn, and the polyester filament yarn Y forming an inner layer part thereof,
   R 2 O—(CH 2 CH 2 O) n (R 1 O) m —R 2   (1)
 
   [where in the formula, R 1  is an alkylene group or a substituted alkylene group having two or more carbon atoms, R 2  is a hydrogen atom, a monovalent hydrocarbon group having 1 to 40 carbon atoms, a monovalent hydroxyhydrocarbon having 2 to 40 carbon atoms, or a monovalent acyl group having 2 to 40 carbon atoms, n is an integer of 1 or more, and m is an integer of 1 or more.]   
     
     
         15 . The antistatic polyester combined filament yarn according to  claim 14 , the core sheath type polyester composite fiber having 3 to 8 fin parts in a shape protruding outwardly from the fiber cross section central part in a cross section orthogonal to the direction of length of the single yarn, and the protrusion coefficient of the fin parts defined by the following equation being 0.3 to 0.7:
   protrusion coefficient=( a 1 −b 1)/ a 1   where a 1 : the length between the center of the inscribed circle of the inner surface wall of the cross section orthogonal to the fiber axis and the fin part top; and   b 1 : the radius of the inscribed circle of the inner surface wall of the cross section orthogonal to the fiber axis.   
     
     
         16 . The antistatic polyester combined filament yarn according to  claim 14 , the core sheath type polyester composite fiber having a flat shape including 3 to 6 round cross section single yarns bonded to one another in the longitudinal direction in a cross section orthogonal to the direction of length of the single yarn, and the flatness α/β expressed as the ratio of the maximum diameter α (major axis) of the flat shape and the length β of the maximum diameter (minor axis) orthogonal to the major axis being 3 to 6. 
     
     
         17 . A cloth characterized by including the antistatic polyester combined filament yarn according to  claim 14 . 
     
     
         18 . A method for producing an antistatic polyester combined filament yarn, characterized by: subjecting, an antistatic polyester filament yarn X′ having an elongation (ELA) of 80% or more, an elastic recovery at 10% elongation (ERA) of 50% or less, an elongation shear modulus (EMA) of 5.89 GPa or less, a crystallinity (XpA) of 25% or more, a boiling water shrinkage (BWSA) of 3% or less, and a thermal stress at 160° C. (TSA) of 0.44 mN/dtex or less, and satisfying the requirements of the following (i) and the like, to a relaxation heat treatment, then, merging it with a polyester filament yarn Y′ having an elongation (ELB) of 40% or less, an elongation shear modulus (EMB) of 7.85 GPa or more, a boiling water shrinkage (BWSB) of 5% or more, and a thermal stress at 160° C. (TSB) of 0.88 mN/dtex or more such that the weight ratio of the polyester multifilament yarn X′ and the polyester multifilament yarn Y′ is 45/55 to 70/30, and then, performing an entanglement treatment:
 (i) the antistatic polyester multifilament yarn X′ being a core sheath type polyester composite fiber having a core part including a polyester A, and a sheath part including a copolymerized polyester B, the polyester A comprising an antistatic polyester containing, as an antistatic agent, (a) a polyoxyalkylene type polyether represented by the following general formula (1) in an amount of 0.2 to 30 parts by weight, and (b) an organic ionic compound substantially nonreactive with the polyester in an amount of 0.05 to 10 parts by weight per 100 parts by weight of an aromatic polyester; and 
 (ii) the single yarn fineness of the polyester multifilament yarn X′ being 1.5 dtex or less;
   R 2 O—(CH 2 CH 2 O) n (R 1 O) m —R 2   (1)
 
 
 [where in the formula, R 1  is an alkylene group or a substituted alkylene group having two or more carbon atoms, R 2  is a hydrogen atom, a monovalent hydrocarbon group having 1 to 40 carbon atoms, a monovalent hydroxyhydrocarbon having 2 to 40 carbon atoms, or a monovalent acyl group having 2 to 40 carbon atoms, n is an integer of 1 or more, and m is an integer of 1 or more.] 
 
     
     
         19 . The method for producing an antistatic polyester combined filament yarn according to  claim 18 , the core sheath type polyester composite fiber having 3 to 8 fin parts in a shape protruding outwardly from the fiber cross section central part in a cross section orthogonal to the direction of length of the single yarn, and the protrusion coefficient of the fin parts defined by the following equation being 0.3 to 0.7:
   protrusion coefficient=( a 1 −b 1)/ a 1   where a 1 : the length between the center of the inscribed circle of the inner surface wall of the cross section orthogonal to the fiber axis and the fin part top; and   b 1 : the radius of the inscribed circle of the inner surface wall of the cross section orthogonal to the fiber axis.   
     
     
         20 . The method for producing an antistatic polyester combined filament yarn according to  claim 18 , the core sheath type polyester composite fiber having a flat shape including 3 to 6 round cross section single yarns bonded to one another in the longitudinal direction in a cross section orthogonal to the direction of length of the single yarn, and the flatness α/β expressed as the ratio of the maximum diameter α (major axis) of the flat shape and the length β of the maximum diameter (minor axis) orthogonal to the major axis being 3 to 6. 
     
     
         21 . A cloth characterized by including the antistatic polyester combined filament yarn produced by the method for producing an antistatic polyester combined filament yarn according to  claim 18 .