JP2007154343A - Core-sheath conjugate type partially oriented fiber of polyester and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a core-sheath conjugate type partially oriented fiber of polyester, having excellent color development and soft properties as a fiber textile, also having high strength, providing excellent false-twisting processability and suitable for a car sheet use. <P>SOLUTION: The core-sheath conjugate type partially oriented fiber of the polyester is a conjugate fiber obtained by arranging a polyethylene terephthalate at the core part and a polytrimethylene terephthalate at the sheath part and having a concentrically circular cross section shape in the longitudinal direction. The intrinsic viscosity of the polytrimethylene terephthalate to be arranged at the sheath part is higher than that of the polyethylene terephthalate to be arranged at the core part, and the difference of the intrinsic viscosities is 0.4-1.0. The core-sheath conjugate type partially oriented fiber satisfies the following requirements (A) to (D): (A) the single fiber fineness is 1.0-2.8 dtex; (B) the strength is ≥2.0 cN/dtex; (C) the elongation is 90-160%; and (D) the shrinkage in warm water is 1.5-10.0%. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  TECHNICAL FIELD The present invention relates to a polyester composite fiber having a core-sheath cross-sectional structure, and more specifically, a car seat that is excellent in color development and softness of a fiber fabric, has high strength, and is also excellent in false twist processing. Polyester core-sheath composite type partially oriented fiber suitable for use.

  Polytrimethylene terephthalate (hereinafter sometimes referred to as 3GT) obtained by polycondensation of lower alkyl ester of terephthalic acid represented by terephthalic acid or dimethyl terephthalate and trimethylene terephthalate has a low elastic modulus and softness. In recent years, the demand has greatly expanded because high stretchability can be obtained by applying false twisting in addition to the characteristics of a smooth texture and easy dyeability.

Among the known technologies related to 3GT, as a technology related to partially oriented fibers suitable for false twisting, for example, a 3GT polymer having a high polymerization degree is melt-spun and then wound at an extremely low tension to cause tightening or bulging. Suppressing and improving the false twisting processability at high speed (see Patent Document 1) and using a taper roll in the heat treatment part to compensate for the fiber elongation due to heat can suppress yarn breakage due to yarn slack. In addition, since a heat treatment can be performed at a higher temperature, a technique (see Patent Document 2) that enables long-term storage of partially oriented fibers has been proposed. However, in any known technique, 3GT alone does not yield a fiber having high strength, leading to a decrease in high-order workability such as false twisting, and there is a disadvantage that the strength is insufficient when a fiber fabric is used, Further, since the fiber fabric curls during weaving or knitting or after it because of its high shrinkability, for example, when it is used as a car seat, there is also a problem that molding processability is remarkably lowered. As described above, a partially oriented fiber of 3GT alone has not been obtained so far, which has a high strength rich in color development, softness and processability unique to 3GT.
In order to make up for the shortcomings of these 3GTs alone, development of a core-sheath composite fiber of polyethylene terephthalate (hereinafter sometimes referred to as PET) and 3GT has been promoted and is also known as a known technique. For example, it has low-temperature dyeability, heat-setting properties, and fastness properties, and has high strength and an appropriate elastic modulus, so that it is excellent in handling at the time of weaving and knitting and has a soft texture. A technique (see Patent Document 3) has been proposed. However, known techniques relating to these core-sheath composite fibers do not disclose a technique related to core-sheath composite-type partially oriented fibers that have both high strength and 3GT characteristics and are suitable for false twisting.
JP 2002-61038 A (Claims) JP 2003-227031 A (Claims) JP 11-93021 A (Technical field to which the invention belongs)

  Therefore, an object of the present invention is a polyester composite fiber having a core-sheath cross-sectional structure, which is excellent in color development and softness of a fiber fabric, has high strength, and further has excellent false twisting workability. It is an object to provide a polyester core-sheath composite-type partially oriented fiber suitable for the above.

  The inventors of the present invention have arrived at the present invention as a result of intensive studies to solve the problems that could not be solved by the above-described prior art.

  That is, the polyester core-sheath composite-type partially oriented fiber of the present invention and the production method thereof have the following configuration.

(1) Polyethylene terephthalate containing terephthalic acid as an acid component and ethylene glycol as a glycol component is arranged in the core, and polytrimethylene terephthalate containing terephthalic acid as an acid component and trimethylene glycol as a glycol component is arranged in the sheath. A composite fiber having a concentric core-sheath cross-sectional shape in the longitudinal direction, wherein the intrinsic viscosity of polytrimethylene terephthalate disposed in the sheath is higher than the intrinsic viscosity of polyethylene terephthalate disposed in the core, and A polyester core-sheath composite-type partially oriented fiber having an intrinsic viscosity difference of 0.4 to 1.0 and further satisfying the following requirements (A) to (D).
(A) The single yarn fineness is 1.0 to 2.8 dtex.
(B) The strength is 2.0 cN / dtex or more.
(C) The elongation is 90 to 160%.
(D) The hot water shrinkage rate is 1.5 to 10.0%.

  (2) The weight ratio between the core and the sheath is in the range of 20:80 to 55:45, the intrinsic viscosity of the core is in the range of 0.40 to 0.68, and the intrinsic viscosity of the sheath is 0.00. The polyester core-sheath composite-type partially oriented fiber according to (1), which is in a range of 80 to 1.68.

  (3) The polyester core-sheath composite-type partially oriented fiber according to (1) or (2), which is subjected to stretch false twisting.

  (4) The polyester core-sheath composite-type partially oriented fiber according to any one of (1) to (3), which is used for a car seat.

  (5) Polyethylene terephthalate containing terephthalic acid as an acid component and ethylene glycol as a glycol component is arranged in the core, polytrimethylene terephthalate containing terephthalic acid as an acid component and trimethylene glycol as a glycol component is arranged in the sheath. When the composite fiber having a concentric core-sheath cross-sectional shape in the longitudinal direction is melt-spun, the molten polymer extruded from the spinning hole is cooled and solidified and taken up in a partially oriented region at a speed of 2000 to 3500 m / min, After performing heat treatment at a temperature of 70 to 130 ° C. in any one of the plurality of rollers via two or more rollers for control at a tension of 0.02 to 0.15 cN / dtex and yarn cooling, The polyester as described in (1) above, which is wound at a tension of 0.05 to 0.2 cN / dtex. Tel sheath composite part manufacturing method of oriented fibers.

  (6) Polyester core-sheath composite-type partially oriented fiber obtained by the method for producing a polyester core-sheath composite-type partially oriented fiber according to claim 5 according to (5), yarn speed of 100 to 1000 m / min, heat set temperature. A method for producing a false twisted yarn, comprising false twisting under conditions of 100 to 200 ° C and a winding tension of 0.02 to 0.10 cN / dtex.

  According to the present invention, a polyester core-sheath composite suitable for car seat use, which has not been able to be achieved in the past, is excellent in color development and softness of fiber fabrics, has high strength, and has excellent false twisting workability. A partially oriented fiber is obtained.

  The polyester core-sheath composite-type partially oriented fiber of the present invention has a concentric core-sheath cross-sectional shape composed of a core part and a sheath part, and 90% by mole or more of polymer PET disposed in the core part is ethylene terephthalate. Polyethylene terephthalate consisting of repeating units. Polyethylene terephthalate is a polyester obtained using terephthalic acid as the main acid component and ethylene glycol as the main glycol component. However, it may contain a copolymer component capable of forming another ester bond at a ratio of 10 mol% or less. Examples of the copolymerizable compound include dicarboxylic acids such as isophthalic acid, cyclohexanedicarboxylic acid, adipic acid, dimer acid and sebacic acid, while glycol components include, for example, ethylene glycol, diethylene glycol, butanediol, neopentyl glycol, Examples thereof include, but are not limited to, cyclohexanedimethanol, polyethylene glycol, and polypropylene glycol. In addition, titanium dioxide as a matting agent, silica or alumina fine particles as a lubricant, hindered phenol derivatives or coloring pigments as an antioxidant can be added to the core as necessary.

  Further, 3GT of the polymer arranged in the sheath part is polytrimethylene terephthalate in which 90 mol% or more is composed of repeating units of trimethylene terephthalate. Polytrimethylene terephthalate is a polyester obtained using terephthalic acid as the main acid component and trimethylene glycol as the main glycol component. However, it may contain a copolymer component capable of forming another ester bond at a ratio of 10 mol% or less. Examples of the copolymerizable compound include dicarboxylic acids such as isophthalic acid, cyclohexanedicarboxylic acid, adipic acid, dimer acid and sebacic acid, while glycol components include, for example, ethylene glycol, diethylene glycol, butanediol, neopentyl glycol, Examples thereof include, but are not limited to, cyclohexanedimethanol, polyethylene glycol, and polypropylene glycol. In addition, titanium dioxide as a matting agent, fine particles of silica or alumina as a lubricant, hindered phenol derivatives or coloring pigments as an antioxidant can be added to the sheath as necessary.

  In the present invention, the intrinsic viscosity of 3GT of the polymer disposed in the sheath is made higher than the intrinsic viscosity of the polymer PET disposed in the core, but the intrinsic viscosity difference is 0.4-1. Must be zero. If the difference in intrinsic viscosity is smaller than the specified range, if the viscosity of PET is increased, it is generally necessary to set the spinning temperature to be higher in accordance with the viscosity. At higher spinning temperatures, the thermal degradation of 3GT proceeds, and spun yarn breakage occurs. Of course, higher-order processability is reduced due to strength reduction, and further, color developability and softness are reduced. In softness, for example, when a car seat is used, the touch becomes worse. Similarly, when the viscosity of 3GT is lowered, the 3GT characteristics such as color developability and softness are not exhibited, and it is not suitable for a car seat. The range of the intrinsic viscosity difference is preferably 0.5 or more.

  On the other hand, when the difference in intrinsic viscosity is larger than the specified range, when the viscosity of the PET is lowered, the strength reinforcing effect of the PET is lost, the generation of low-strength yarn and the accompanying lowering of high-order workability, and as a car seat Is weak against rub resistance and tearing. Further, when the viscosity of 3GT is increased, it is difficult to produce the yarn itself. The range of the intrinsic viscosity difference is preferably 0.8 or less.

  The single fiber fineness of the polyester core-sheath composite-type partially oriented fiber of the present invention needs to be 1.0 to 2.8 dtex. When the single fiber fineness is less than 1.0 dtex, the softness is good, but the feeling of elasticity is lost, and the strength reinforcement effect by PET does not make sense, leading to a reduction in high-order workability. The range of the single fiber fineness is preferably 1.4 dtex or more. Further, when the single fiber fineness exceeds 2.8 dtex, the texture becomes hard. For example, even when a fiber fabric having a high bulkiness such as a velor tone is used, the touch is bad and it is not suitable for a car seat. The range of the single fiber fineness is preferably 2.5 dtex or less. The single fiber fineness within the above range can be obtained by changing an appropriate polymer discharge amount and the number of filaments.

  The strength of the polyester core-sheath composite-type partially oriented fiber of the present invention needs to be 2.0 cN / dtex or more. When the strength is less than 2.0 dtex, the strength reinforcement effect by PET does not make any sense, and this leads to a decrease in high-order workability, and also the feeling of harshness is lost and the touch becomes poor. Not suitable as a sheet. The strength is preferably 2.2 dtex or more. Further, in order to obtain a car seat that exhibits the softness unique to 3GT and has a better touch, the strength is preferably 7.0 cN / dtex or less. The strength in the above range can be obtained by drawing the yarn around a roller having an appropriate speed.

  The elongation of the polyester core-sheath composite-type partially oriented fiber of the present invention needs to be 90 to 160%. The partially oriented fiber referred to in the present invention is a fiber in which an oriented portion and a non-oriented portion are mixed, and is particularly suitable for performing so-called post-processing such as false twisting. Specifically, it means that the elongation is in the above range, and by controlling the elongation within this range, false twisting and blending with other fibers can be easily achieved. When the elongation is less than 90%, the high-order workability such as false twisting is deteriorated, and the texture becomes hard. For example, even when a fabric having a high bulkiness such as a velour is used, the touch is poor, and the car seat Not suitable for. The range of elongation is preferably 100% or more. On the other hand, when the elongation exceeds 160%, the harshness is lost and the touch becomes worse, so it is not suitable as a car seat. The range of elongation is preferably 150% or less. The elongation in the above range can be obtained by using a polymer having an appropriate intrinsic viscosity and drawing the yarn around a roller having an appropriate speed.

  The warm water shrinkage of the polyester core-sheath composite-type partially oriented fiber of the present invention is a shrinkage under 70 ° C. warm water, and needs to be 1.5 to 10.0%. In the case of low shrinkage where the hot water shrinkage rate is less than 1.5%, the softness is lowered, and for example, when it is used as a car seat, the touch becomes worse. The range of the hot water shrinkage rate is preferably 2.0% or more. Also, when the hot water shrinkage rate is higher than 10.0%, that is, when thermal crystallization is not progressing, the yarn shrinks even during winding or after winding, and the package is wound up. This is not suitable for applications that require long-term storage, such as false twisting, as a material for car seats. For example, when a structure such as a tricot velor is used, curling of the fiber fabric occurs, resulting in a decrease in quality and a resulting decrease in workability during molding. The range of the hot water shrinkage rate is preferably 8.0% or less, and more preferably 6.0% or less. The hot water shrinkage in the above range can be obtained by using a polymer having an appropriate intrinsic viscosity and drawing the yarn around a roller heated to an appropriate speed and an appropriate temperature.

  The polyester core-sheath composite-type partially oriented fiber of the present invention can be produced as follows. For example, polyethylene terephthalate containing terephthalic acid as an acid component and ethylene glycol as a glycol component is arranged in the core, polytrimethylene terephthalate containing terephthalic acid as an acid component and trimethylene glycol as a glycol component is arranged in the sheath. When the composite fiber having a concentric core-sheath cross-sectional shape in the longitudinal direction is melt-spun, the molten polymer extruded from the spinning hole is cooled and solidified, taken up in a partially oriented region at a speed of 2000 to 3500 m / min, and the process tension is 0 0.02 to 0.15 cN / dtex for control and yarn cooling via two or more rollers, and after heat treatment at 70 to 130 ° C. in any of these rollers, tension of 0.05 to It can be manufactured by winding at 0.2 cN / dtex.

  If the take-up speed is less than 2000 m / min, it is difficult to produce the yarn itself, and this leads to a decrease in productivity, which is not preferable. In addition, when the take-up speed exceeds 3500 m / min, not only the orientation progresses from the polymer discharge hole to the take-off, but the softness is deteriorated, and the false twist processability and the quality after the false twist process are remarkably lowered. Therefore, it is not preferable. The take-up speed is more preferably 2500 to 3300 m / min, and further preferably 2500 to 3100 m / min.

  In addition, the process tension is not preferable at a low tension less than 0.02 cN / dtex because the yarn itself becomes difficult, and a high tension exceeding 0.15 cN / dtex is not preferable. This is not suitable for applications that require long-term storage, such as false twisting, and after false twisting, as a material for car seats, for example, a structure like tricot velor. Is unfavorable because curling of the fiber fabric occurs, resulting in a decrease in quality and a resulting decrease in workability during molding. The process tension is more preferably 0.03 to 0.13 cN / dtex.

  The heat treatment temperature is preferably not less than the thermal crystallization temperature of 3GT and not more than the thermal crystallization temperature of PET. At low temperatures where the heat treatment temperature is less than 70 ° C., the heat crystallization temperature is less than 3GT, so the shrinkage is high and the package is tightly wound and the package yarn quality is changed over time. It is not suitable for applications that require long-term storage, and after false twisting, the material for car seats, for example, a structure such as tricot velor, causes fabric curling and deterioration in quality. This is not preferred because the workability during molding is reduced. In addition, when the heat treatment temperature is higher than 130 ° C., the thermal crystallization temperature of PET is exceeded, which leads to a decrease in shrinkage and a significant decrease in high-order workability. Since it feels bad when it is used as a sheet, it is not preferable. The heat treatment temperature is more preferably 80 to 120 ° C, still more preferably 90 to 120 ° C.

  In addition, when the winding tension is less than 0.05 cN / dtex, it is difficult to produce the yarn itself, and when the winding tension exceeds 0.2 cN / dtex, the package is tightened. It is not suitable for applications that require long-term storage such as false twisting, and after twisting, as a car seat material, for example, tricot velor When it is made into a structure, curling of the fiber fabric occurs, resulting in deterioration of quality and accompanying reduction in workability during molding, which is not preferable. The winding tension is more preferably 0.07 to 0.15 cN / dtex.

  It is also possible to entangle the fiber yarn using a known entanglement device until winding. If necessary, the number of entanglements can be increased by giving entanglement multiple times. Furthermore, it is allowed to add an additional oil agent immediately before winding.

  According to a preferred embodiment of the polyester core-sheath composite-type partially oriented fiber of the present invention, the polyester core-sheath composite-type partially oriented fiber is subjected to known false twist processing such as belt false twist, pin false twist, and disk false twist. . When drawing false twisting, the yarn speed is preferably 100 to 1000 m / min. When the yarn speed is 100 m / min or more, the occurrence of dyed spots can be suppressed, which leads to improvement in the quality of a car seat. The yarn speed is more preferably 200 m / min or more. Further, when the yarn speed is 1000 m / min or less, it is possible to suppress false twisting and thread breakage, leading to improvement in quality as a car seat. The yarn speed is more preferably 800 m / min or less.

  When the polyester core-sheath composite-type partially oriented fiber of the present invention is stretched and false twisted, the heat treatment temperature is preferably 100 to 200 ° C. When the heat treatment temperature is 100 ° C. or more, after false twisting, as a material for a car sheet, for example, when a structure such as a tricot velor is used, the quality of the car sheet deteriorates due to the occurrence of curling of the fiber fabric, and the molding associated therewith. The workability deterioration at the time is suppressed. The heat treatment temperature is more preferably 120 ° C. or higher. When the heat treatment temperature is 200 ° C. or lower, the running state of the yarn becomes more stable, leading to suppression of yarn breakage and the like.

  When the polyester core-sheath composite-type partially oriented fiber of the present invention is stretched and false twisted, the winding tension is preferably 0.02 to 0.1 cN / dtex. When the winding tension is 0.02 cN / dtex or more, package foam collapse does not occur. The winding tension is more preferably 0.04 cN / dtex or more. If the winding tension is 0.1 cN / dtex or less, package winding does not occur.

  Moreover, the polyester core-sheath composite type partially oriented fiber of the present invention can be used as a car seat application.

  In the polyester core-sheath composite-type partially oriented fiber of the present invention, the weight ratio of the core part to the sheath part is in the range of 20:80 to 55:45 in order not to impair the color development property and softness characteristic of 3GT. It is appropriate that the intrinsic viscosity of is in the range of 0.40 to 0.68, and the intrinsic viscosity of 3GT is in the range of 0.80 to 1.68.

  In the production of the polyester core-sheath composite-type partially oriented fiber of the present invention, the melt spinning method is most excellent in view of the stability and productivity of the composite structure. When melt spinning the polyester core-sheath-type partially oriented fiber of the present invention, the PET serving as the core is preferably melted at a temperature of 260 to 300 ° C. In the melting, a pressure melter method and an extruder method can be mentioned, and melting by the extruder method is preferable from the viewpoint of uniform melting and retention prevention.

  Moreover, it is preferable that 3GT used as a sheath part is melt | dissolved at the temperature of 240-280 degreeC using an extruder similarly to PET. Separately melted polymers pass through separate pipes, weigh and then flow into the pack. Under the present circumstances, it is preferable to set piping passage time to 5 to 30 minutes from a viewpoint of polymer thermal deterioration suppression. The polymer that has flowed into the pack merges at the base, and is then combined and discharged into a concentric core-sheath form by a known technique. The polymer temperature at this time is suitably 263 to 280 ° C. If it is this range, the productivity fall by the polymer thermal degradation, the color development, and the fall of a soft feeling can be prevented preferably.

  FIG. 1 is a schematic process diagram for exemplifying a process for producing a polyester core-sheath composite-type partially oriented fiber of the present invention, and FIG. 2 is another process for producing a polyester core-sheath composite-type partially oriented fiber of the present invention. It is a general | schematic process figure for demonstrating this. The polyester core-sheath composite-type partially oriented fiber of the present invention can be preferably produced through a process as shown in FIG. 1 or FIG.

  In FIG. 1, after the molten polymer is discharged from the base 1, the yarn is cooled by the yarn cooling air blower 2, the oil agent is applied to the yarn by the oil agent applying device 3, and then entangled by the entanglement device 4. The applied yarn is taken up by the first roller 5, simultaneously subjected to heat treatment, the process tension is controlled via the second roller 6, and the winding package 8 is obtained via the contact roller 7. 2 is an entanglement device for converging the yarn after discharging the molten polymer from the base 9, cooling the yarn with the yarn cooling air blower 10, and applying the oil to the yarn with the oil applying device 11. 12 is entangled by the first roller 13, and is heat treated by one or both of the first roller 13 and the second roller 14, and then entangled by the entanglement device 15. The third roller 16 and the second Controls process tension through the rollers 17, a reeling step of the winding package 19 via a contact roller 18, both of which are effective reeling process the cooling of the yarn. However, a manufacturing process is not limited to these, For example, it is also possible to change the number of rollers through which it winds up as needed.

  The polyester core-sheath composite-type partially oriented fiber of the present invention is particularly suitable for car seat applications. Specifically, the polyester core-sheath composite-type partially oriented fiber obtained in the present invention is less likely to cause curling of the fiber fabric and has good workability when molding a car seat. In addition, a uniform surface feeling produced by the soft feeling, color developability, and uniform dyeability unique to 3GT can be obtained. As a car seat, the application method is not limited to this, and it is possible to interweave and knit with natural fibers such as composite false twist and mixed fibers with other fibers and cotton.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated concretely, this invention is not limited to these Examples. Moreover, the main measured values in the examples were measured by the following methods.

(1) Intrinsic viscosity Intrinsic viscosity [η] is obtained by measuring the viscosity of 3GT and PET diluted solution at a temperature of 25 ° C. dissolved in o-chlorophenol having a purity of 98% or more, and is based on the following definition formula: This is the value obtained by

  The definition formula ηr is a value obtained by dividing the viscosity of a diluted solution of 3GT and PET dissolved in o-chlorophenol having a purity of 98% or more at a temperature of 25 ° C. by the viscosity of the solvent itself measured at the same temperature, It is defined as relative viscosity. C is the solute weight value in grams in 100 ml of the solution.

(2) Strength and elongation Measured according to JIS L1013 (1999).

(3) Warm water shrinkage rate The warm water shrinkage rate (%) is a value determined based on the following equation.
Hot water shrinkage (%) = ((L0−L1) / L0) × 100
L0: skein of raw yarn, skein length at a measurement load of 0.0053 cN / dtex L1: treatment of raw yarn with no load in warm water at a temperature of 70 ° C. for 10 minutes, air drying, measurement load of 0. Skein length when multiplied by 0053 cN / dtex.

(4) Color developability Sample A obtained by subjecting the polyester core-sheath composite partially oriented fiber of the present invention to stretching false twisting using a belt false twisting machine and PET single partially oriented fiber similarly using a belt false twisting machine. Using 100% of each sample of twisted sample B, a 36-gauge tricot velor fabric was prepared, scoured at a temperature of 80 ° C., and then used as a dye Tetraseal Navy Blue SGL 0.275% by Nagase Sangyo Co., Ltd. owf, Tetrocin PE-C 5.0% owf manufactured by Shoken Chemical Co., Ltd. as an auxiliary agent, “Nikka Sun Salt” (registered trademark) # 12001.0% owf manufactured by Nikka Chemical Co., Ltd. as a dispersant, Staining was performed at a ratio of 1: 100 at 50 ° C. for 15 minutes, and further at 90 ° C. for 20 minutes. The dyeing difference between the samples A and B after dyeing was comprehensively subjected to a sensory test and evaluated in three stages, with ◯ and ◯ as pass and x as failure. As the PET single partially oriented fiber, a 100 dtex-60 filament (hereinafter abbreviated as f) was used.
◯: Excellent ◯: Excellent ×: PET equivalent (no color development improvement)

(5) Dyeing uniformity The fabric samples A and B obtained in (4) above were dyed by the same method as in (4) and then dried, and the dyeing uniformity was evaluated. Judgment criteria for dyeing uniformity are 0 points on the basis of the fabric without dyeing, and 0 to 50 points are evaluated. Three-point evaluation is made based on the following evaluation criteria, and ○ and ○○ are passed. And x was rejected.
◯: 0 to 10 points ◯: 11 to 30 points ×: 31 points or more.

(6) Softness The fabric samples A and B obtained in the above (4) were touched by 10 panelists to evaluate whether the softness was good. The evaluation criteria were as follows, where ◯ and OO were accepted and x was rejected.
○○: Very good ○: Good ×: Equivalent to PET

(7) Curling resistance The fabric obtained in (4) above is cut out to 30 cm × 50 cm, one side of the short side of the fabric is fixed, and the other is placed on a horizontal table in a free state where no load is applied. Then, the contact area of the fabric at that time was measured, the ratio of the contact surface to the entire surface of the fabric was determined, and a three-step evaluation was made based on the following evaluation criteria.
○○: 100% (no curl)
○: 95% or more and less than 100% ×: less than 95%.

(8) Higher-order workability Fiber obtained by subjecting the polyester core-sheath composite type partially oriented fiber of the present invention to stretch false twisting under conditions of a yarn speed of 300 m / min, a heat treatment temperature of 160 ° C., and a winding tension of 0.05 cN / dtex. The number of fluff generation was evaluated. The evaluation criteria were as follows, where ◯ and OO were accepted and x was rejected. The fluff measurement was carried out using a fly counter (trade name) manufactured by Toray Industries, Inc. while running the yarn at a constant speed of 500 m / min.
○○: Less than 1 fluff ○: 1 to less than 5 fluff ×: 5 or more fluff.

Example 1
According to the process shown in FIG. 2, a polyester core-sheath composite-type partially oriented fiber was produced. PET of intrinsic viscosity 0.51 and 3GT of intrinsic viscosity 1.13 were melted at temperatures of 285 ° C and 260 ° C, respectively, using an extruder, measured by a pump, and a concentric core sheath cross section at a polymer temperature of 270 ° C. In order to form the shape, it was allowed to flow into a base designed to allow 3GT arranged in the sheath to flow around the PET arranged in the core. The composite ratio (weight ratio) of both the core part and the sheath part was set to a ratio of PET: 3GT = 30: 70. Pipe passage time of each polymer was 12 minutes for PET and 5 minutes for 3GT. The yarn discharged from the base is cooled and applied with an oil agent, taken up by the non-heated first roller 13 at a speed of 2900 m / min, and heated to a temperature of 100 ° C. without being wound once, at a speed of 3000 m / min. The second roller 14 was drawn and heat-treated. Then, the unrolled third roller 16 set at the same speed as the second roller and the fourth roller 17 were wound around, wound up with a tension of 0.10 cN / dtex, 100 dtex-60f, single fiber fineness of 1.7 dtex. A polyester core-sheath composite-type partially oriented fiber was obtained. The results of physical properties and texture evaluation of the obtained polyester core-sheath composite-type partially oriented fiber are as shown in Table 1. Excellent color development and softness, good dyeing uniformity and curl resistance, It was suitable. Moreover, high-order workability was also good.

(Example 2)
Except that the heat treatment temperature was 130 ° C., yarn was produced under the same conditions as in Example 1 to obtain a polyester core-sheath composite-type partially oriented fiber with 100 dtex-60f and a single fiber fineness of 1.7 dtex. The results of physical properties and texture evaluation of the obtained polyester core-sheath composite-type partially oriented fiber are as shown in Table 1. Although slightly inferior to Example 1, it has excellent color development and softness, dyeing uniformity and curl resistance. And was suitable for a car seat. Moreover, high-order workability was also good.

(Example 3)
A yarn was produced under the same conditions as in Example 1 except that PET with an intrinsic viscosity of 0.70 was used, the intrinsic viscosity difference was 0.43, and the polymer temperature was 275 ° C. 100 dtex-60f, single fiber fineness 1 A 7 dtex polyester core-sheath composite-type partially oriented fiber was obtained. The results of physical properties and texture evaluation of the obtained polyester core-sheath composite-type partially oriented fiber are as shown in Table 1. Although slightly inferior to Example 1, it has excellent color development and softness, dyeing uniformity and curl resistance. And was suitable for a car seat. Moreover, high-order workability was also good.

Example 4
Polyester core-sheath composite partial orientation with 100 dtex-60f and single fiber fineness of 1.7 dtex was produced under the same conditions as in Example 1 except that the composite ratio was set to a ratio of PET: 3GT = 50: 50. Fiber was obtained. The results of physical properties and texture evaluation of the obtained polyester core-sheath composite-type partially oriented fiber are as shown in Table 1. Although slightly inferior to Example 1, it has excellent color development and softness, dyeing uniformity and curl resistance. And was suitable for a car seat. Moreover, high-order workability was also good.

(Comparative Example 1)
Except that the heat treatment temperature was 40 ° C., yarn was produced under the same conditions as in Example 1 to obtain a polyester core-sheath composite-type partially oriented fiber of 100 dtex-60f and a single fiber fineness of 1.7 dtex. The results of physical properties and texture evaluation of the obtained polyester core-sheath composite type partially oriented fiber are as shown in Table 2, and although the color development and softness were good, they were satisfactory in dyeing uniformity and curl resistance. It was not suitable for car seats, and it was due to tightening of the package (Comparative Example 2)
Polyester core-sheath composite of 100 dtex-60f and single fiber fineness of 1.7 dtex was produced under the same conditions as in Example 1 except that 3GT having an intrinsic viscosity of 0.75 was used and the difference in intrinsic viscosity was 0.24. A mold partly oriented fiber was obtained. The results of physical properties and texture evaluation of the obtained polyester core-sheath composite-type partially oriented fibers are as shown in Table 2, and although the dyeing uniformity, curl resistance and high-order processability were good, the color developability and softness It was not satisfactory and was not suitable for car seats.

(Comparative Example 3)
Except that the single fiber fineness was 0.7 dtex, yarn was produced under the same conditions as in Example 1 to obtain a 100 dtex-144f polyester core-sheath composite partially oriented fiber. The results of physical properties and texture evaluation of the obtained polyester core-sheath composite-type partially oriented fiber are as shown in Table 2, and although the color developability, softness and curl resistance were good, they were not satisfactory in dyeing uniformity. In addition to being not suitable for car seats, the number of fluff generation was high in high-order workability, and it was not suitable for false twisting.

(Comparative Example 4)
A 3GT single yarn of 100 dtex-60f was obtained by spinning under the same conditions as in Example 1 except that PET with an intrinsic viscosity of 0.51 was spun alone. The results of physical properties and texture evaluation of the obtained single polyester yarn are as shown in Table 2. Although they were excellent in dyeing uniformity, curl resistance and high-order processability, they were the most inferior in color development and softness. Yes, it was not suitable for car seats.

(Comparative Example 5)
A 3GT single yarn of 100 dtex-60f was obtained by spinning under the same conditions as in Example 1 except that 3GT having an intrinsic viscosity of 1.13 was spun alone. The results of physical properties and texture evaluation of the obtained polyester single yarn are as shown in Table 2. Although it was excellent in softness and dyeability and color development, it was the most inferior in curling resistance, In addition, the number of fluff generations was high in high-order processability, and it was not suitable for false twisting.

  The polyester core-sheath composite-type partially oriented fiber of the present invention is less likely to cause curling of the fiber fabric, has good processability at the time of car seat molding, and has a soft feeling and color developability unique to 3GT, and uniform dyeability. Creates a uniform surface feel. Therefore, the polyester core-sheath composite-type partially oriented fiber of the present invention is particularly useful for car seat applications.

FIG. 1 is a schematic process diagram for exemplifying a process for producing a polyester core-sheath composite-type partially oriented fiber of the present invention. FIG. 2 is a schematic process diagram for exemplifying another spinning process of the polyester core-sheath composite-type partially oriented fiber of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Base 2 Yarn cooling air blower 3 Oil supply device 4 Entanglement device 5 1st roller 6 2nd roller 7 Contact roller 8 Package 9 Base 10 Yarn cooling air blower 11 Oil supply device 12 Entanglement device 13 1st roller 14 2nd Roller 15 Entangling device 16 Third roller 17 Fourth roller 18 Contact roller 19 Package

Claims (6)

A polyethylene terephthalate containing terephthalic acid as an acid component and ethylene glycol as a glycol component is arranged in the core, and a polytrimethylene terephthalate containing terephthalic acid as an acid component and trimethylene glycol as a glycol component is arranged in the sheath. A composite fiber having a concentric core-sheath cross-sectional shape in the direction, wherein the intrinsic viscosity of polytrimethylene terephthalate arranged in the sheath is higher than the intrinsic viscosity of polyethylene terephthalate arranged in the core, and A polyester core-sheath composite-type partially oriented fiber having an intrinsic viscosity difference of 0.4 to 1.0 and further satisfying the following requirements (A) to (D).
(A) The single fiber fineness is 1.0 to 2.8 dtex.
(B) The strength is 2.0 cN / dtex or more.
(C) The elongation is 90 to 160%.
(D) The hot water shrinkage rate is 1.5 to 10.0%.   The weight ratio of the core part to the sheath part is in the range of 20:80 to 55:45, the intrinsic viscosity of the core part is in the range of 0.40 to 0.68, and the intrinsic viscosity of the sheath part is 0.80 to 1. 2. The polyester core-sheath composite-type partially oriented fiber according to claim 1, which is in a range of .68.   The polyester core-sheath composite-type partially oriented fiber according to claim 1 or 2, which has been subjected to stretch false twisting.   The polyester core-sheath composite-type partially oriented fiber according to any one of claims 1 to 3, which is used as a car seat.   A polyethylene terephthalate containing terephthalic acid as an acid component and ethylene glycol as a glycol component is arranged in the core, and a polytrimethylene terephthalate containing terephthalic acid as an acid component and trimethylene glycol as a glycol component is arranged in the sheath. When melt-spinning a composite fiber having a concentric core-sheath cross-sectional shape in the direction, the molten polymer extruded from the spinning hole is cooled and solidified, taken up in a partially oriented region at a speed of 2000 to 3500 m / min, and a process tension of 0.02 After performing heat treatment at a temperature of 70 to 130 ° C. in any of the plurality of rollers through two or more plural rollers for control at ˜0.15 cN / dtex and cooling the yarn, a tension of 0.05 The polyester core sheath according to claim 1, wherein the polyester core sheath is wound at about −0.2 cN / dtex. Method of manufacturing a case-shaped portion oriented fibers.   The polyester core-sheath composite-type partially oriented fiber obtained by the method for producing a polyester core-sheath composite-type partially oriented fiber according to claim 5 is obtained by using a yarn speed of 100 to 1000 m / min, a heat setting temperature of 100 to 200 ° C, and a winding tension. A false twisted yarn manufacturing method, wherein false twist processing is performed under a condition of 0.02 to 0.10 cN / dtex.

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