JP2010053491A - Blended yarn having modified shape and modified fineness - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a new blended yarn having modified shape and modified fineness, imparting woven or knitted fabrics with drapability and soft feeling similar to those of natural fibers in addition to crispness and dry feeling and keeping strength and texture of the woven or knit fabrics even after repeating high temperature humid heat-treatment such as dyeing and steam treatment. <P>SOLUTION: The blended yarn has a fiber formed of a polyester polymer containing ethylene terephthalate as 90 mol% or more of total repeating units, wherein the polyester polymer has a terminal carboxyl group concentration of not more than 25 eq/t, the blended yarn contains a fiber group A having a single fiber fineness of not less than 3 dtex and a fiber group B having a single fiber fineness of not more than 2 dtex, the proportion of the number of single fibers in both fiber groups to the number of the whole blended yarns is specified, the fiber group A includes a fiber having a rotationally asymmetric cross-section having a flat stem part and a protrusion part, and the fiber group B includes a fiber having a round cross-section. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a heterogeneous and different fineness mixed yarn.

  Polyester fibers are widely used as raw materials for woven and knitted fabrics because they can be obtained at low cost and exhibit various excellent properties. In particular, the texture of the woven or knitted fabric using the mixed yarn of irregular and different fineness is popular.

  There are various types of heterogeneous and different fineness blended yarns, and those that can give a particularly excellent texture to woven and knitted fabrics include thick fine yarn groups and fine fine yarn groups, and substantial cross-sectional shapes in the thick fine yarn groups In other words, a heterogeneous and different fineness mixed yarn including a fiber having a non-rotationally symmetric shape having a straight flat trunk portion and a protruding portion has been proposed. By knitting and weaving using this blended yarn, it is possible to give the woven or knitted fabric the same drape and soft feeling as those exhibited by woven or knitted fabric using natural fibers. (See, for example, Patent Documents 1 to 4).

  On the other hand, however, the polyester fiber has a drawback that the ester bond part in the molecule is easily hydrolyzed when placed under high-temperature wet heat. Therefore, for example, when using polyester fibers for uniforms used in the fields of medicine, medical care, foods, etc. that require wet heat sterilization treatment, a special design different from general polyester fibers is adopted in the fiber manufacturing stage. ing.

As a representative example of such a design, it is known to use an antimony compound as a polymerization catalyst when producing a polyester fiber. However, when an antimony compound is used as a polymerization catalyst, it has been pointed out as a problem that metal antimony produced by reduction has an adverse effect on fiber strength and toughness. In order to solve such a problem, for example, a technique for suppressing the carboxyl end group concentration in the molecule to 25 eq / t or less by using an antimony compound and a germanium compound as a polymerization catalyst is disclosed (for example, Patent Document 5). reference). According to this technology, by using an antimony compound and a germanium compound in combination, it is possible to obtain a polyester fiber excellent in strength and toughness because it hardly affects not only the carboxyl end group amount but also the molecular characteristics. it can.
Japanese Patent Laid-Open No. 62-21827 JP 62-90345 A JP-A-62-156327 JP 2004-3051 A Japanese Patent Laid-Open No. 3-161509

  However, in the above-mentioned heterogeneous heterogeneity mixed yarn, since the cross-sectional shapes of the fibers constituting each fiber group are different, a remarkable difference tends to occur between the physical properties of the two, which may cause various troubles. is there. For example, the fine fineness yarn group is more likely to crystallize than the thick fineness yarn group, so that there is a problem that single yarn breakage is likely to occur during the winding process, drawing process, and false false twisting process after spinning. . When a single yarn breaks in the fine yarn group, loops and fluff are generated in the mixed yarn, and false twisting and weaving properties are greatly reduced. In addition, when the woven or knitted fabric is dyed, color spots, gloss spots and the like may be generated. Further, when wet heat sterilization is repeated many times, there is a problem that the strength deterioration of the woven or knitted fabric is accelerated due to the low strength properties of the fine yarn.

  On the other hand, the technique using an antimony compound and a germanium compound as a polymerization catalyst is intended for a polyester fiber for rubber reinforcement, and no means suitable for a polyester fiber for clothing has been proposed yet.

  As described above, the strength of the woven or knitted fabric can be maintained even after repeated wet heat sterilization treatment, and the actual situation is that no woven or knitted fabric with excellent drapeability, soft feeling, tension feeling and dry feeling has been proposed yet. It is.

  The present invention can impart a texture such as a stretchy feeling, dry feeling, natural fiber-like drape, and soft feeling to the woven or knitted fabric, and even if repeated high-temperature wet heat treatment such as dyeing or steam treatment, the woven or knitted fabric It is a technical problem to provide a novel heterogeneous and heterogeneous mixed yarn that can maintain the strength and texture of the yarn.

  The present invention solves such problems, and the gist of the present invention is a mixed yarn comprising fibers formed from a polyester polymer in which 90 mol% or more of all repeating units are ethylene terephthalate. The polyester polymer has a terminal carboxyl group terminal group concentration of 25 eq / t or less, and includes a fiber group A having a single yarn fineness of 3 dtex or more and a fiber group B having a single yarn fineness of 2 dtex or less in the mixed yarn. The ratio of the number of single yarns of the fiber group A to the entire blended yarn is 5 to 50%, and the ratio of the number of single yarns of the fiber group B is 20 to 60%. The fiber group A has a flat trunk portion and a protrusion as a cross-sectional shape. And the fiber group B is a heterogeneous and different fineness mixed yarn characterized in that it is composed of fibers having a circular cross-sectional shape as a cross-sectional shape.

  By using the deformed and different fineness mixed yarn of the present invention, it is possible to obtain a woven or knitted fabric which is excellent in texture and has little strength reduction even when repeated wet heat treatment. Therefore, the irregular-shaped and different-fineness mixed yarn of the present invention can be suitably used for uniforms and the like used in fields where wet heat sterilization is required.

  Hereinafter, the present invention will be described in detail.

  The heterogeneous and different fineness mixed yarn of the present invention is composed of fibers formed from a polyester polymer in which 90 mol% or more of all repeating units is ethylene terephthalate (hereinafter abbreviated as PET). The polyester polymer may contain a copolymer component as long as the effects of the invention are not impaired. Examples of the copolymer component include phthalic acid, isophthalic acid, diphenyldicarboxylic acid, and trimethylene glycol. .

  The heterogeneous and different fineness mixed yarn of the present invention can impart excellent heat and moisture resistance to a woven or knitted fabric. Therefore, it is necessary to set the carboxyl end group concentration in the polyester polymer to 25 eq / t or less, preferably 20 eq / t or less, more preferably 18 eq / t or less. When the carboxyl end group concentration exceeds 25 eq / t, it becomes impossible to impart wet heat resistance to the woven or knitted fabric.

  In order to set the carboxyl group end group concentration to 25 eq / t or less, for example, an antimony compound, a cobalt compound, and a phosphorus compound may be contained in a polymer in a balanced manner. Specifically, each composition is contained in the polymer so as to satisfy the following formulas (1) to (3) simultaneously (the unit is "mol / acid component mole").

(1) 0.5 × 10 ⁻⁴ ≦ [Sb] ≦ 3.0 × 10 ⁻⁴
(2) 0.1 × 10 ⁻⁴ ≦ [Co] ≦ 0.6 × 10 ⁻⁴
(3) 0.1 × 10 ⁻⁴ ≦ [P] ≦ 20.0 × 10 ⁻⁴

  Here, as the antimony compound, antimony trioxide, antimony chloride, antimony acetate, etc., as the cobalt compound, cobalt acetate, cobalt chloride, etc., as the phosphorus compound, trimethyl phosphate, triethyl phosphate, triphenyl phosphate, etc. And so on.

  In general, when an antimony compound and a cobalt compound are used in combination, the color tone of the fiber is improved, and the phosphorus compound has an effect of suppressing the degradation of the color tone of the fiber by the antimony compound and at the same time suppressing the thermal decomposition action by the cobalt compound. Therefore, the dyeability and color development of the woven or knitted fabric can be improved by using a predetermined amount of the three.

  In addition, the carboxyl end group concentration can be made desired by setting the temperature of melt spinning as low as possible.

  In addition, as long as it does not impair the effect of this invention, additives, such as a lubricant, a pigment, antioxidant, a ultraviolet absorber, may be contained in a fiber.

  The mixed yarn of the present invention is a yarn having a different fineness, and the mixed yarn includes fibers having different single yarn fineness. Specifically, a fiber group A having a single yarn fineness of 3 dtex or more and a fiber group B having a single yarn fineness of 2 dtex or less are included.

  The fiber group A greatly contributes to imparting a tightness and dry feeling to the woven or knitted fabric, and the fiber group B greatly contributes to imparting a drape, soft feeling and bulging feeling. However, when the single yarn fineness of the fiber group A is less than 3 dtex, the cross-sectional area of the single yarn becomes small, so that the repulsive force against the lateral force acting on the fiber, bending, twisting, etc. is weakened. The feeling of tightness will be reduced. At the same time, the difference in the single yarn fineness with the fiber group B is also reduced, so that the unevenness on the woven or knitted fabric is reduced, and it tends to be slimy. The single yarn fineness of the fiber group A is particularly preferably 3.5 to 5.0 dtex. On the other hand, when the single yarn fineness of the fiber group B exceeds 2 dtex, the texture of the woven or knitted fabric becomes a rigid texture. The single yarn fineness of the fiber group B is particularly preferably 1.2 to 1.7 dtex.

  As the number of single yarns of each fiber group in the mixed yarn, it is necessary that the fiber group A is 5 to 50% and the fiber group B is 20 to 60% as a ratio to the whole. By increasing the number of single yarns in the fiber group A, a dry feeling can be imparted to the woven or knitted fabric. On the other hand, for the fiber group B, a dry feeling can be imparted to the woven or knitted fabric by reducing the number of single yarns. It is.

  The mixed fiber of the present invention needs to contain two fiber groups as described above, but if necessary, a medium-fine yarn group having a single yarn fineness that is intermediate between both fiber groups may be contained. By appropriately adjusting the amount of the medium-fineness yarn group used, a harmonious texture design can be achieved in the woven or knitted fabric. The composition of the fibers constituting the medium-fine yarn group is preferably basically the same composition as the fibers constituting the fiber group A or B, but any composition as long as the effects of the invention are not impaired. It can be adopted.

  Moreover, as a cross-sectional shape of the fibers constituting each fiber group, a specific shape is adopted from the viewpoint of giving an excellent texture to the woven or knitted fabric. Specifically, for the fiber group A, it is necessary to include a fiber having a non-rotation target cross-sectional shape having a flat trunk portion and a protruding portion. This is because even if a lateral force, bending, twisting, or the like acts on the fiber, the movement and rolling of the fiber is restricted by the presence of the flat trunk, thereby maintaining the gap between the fibers. This is because a swelling feeling can be produced in the knitted fabric, and at the same time, when the woven or knitted fabric is gripped, a finger can be caught on the protrusions to create a dry feeling in the woven or knitted fabric. On the other hand, the fiber group B is composed of fibers having a round cross-sectional shape. This is because a fiber having a round cross-sectional shape does not easily impair false twisting and weaving / knitting properties even in the fineness range, and further, the fiber strength tends not to decrease even after repeated wet heat sterilization.

  Next, the means for obtaining the heterogeneous and different fineness mixed yarn of the present invention will be exemplified.

  The mixed fiber of the present invention can be generally obtained by melt spinning a predetermined polyester polymer. FIG. 1 is a schematic diagram showing an example of a melt spinning apparatus that can be preferably employed in the present invention. In FIG. 1, an annular cooling device 2 and an oiling device 3 are installed below the spinneret 1 along the traveling direction of the spun yarn, and further on the downstream side, a focusing guide 4, an entanglement applying device 5, two stages. The eye oiling device 6, the take-up rollers 7, 7 'and the scooping device 8 are arranged in sequence.

  As the spinneret 1, a yarn having a specific shape is adopted in consideration of the fact that the mixed yarn of the present invention is composed of fibers having a specific fineness and cross-sectional shape. As the die for spinning the fiber group A, for example, those having the shapes shown in FIGS. On the other hand, for the fiber group B, one having a round cross section as shown in FIG.

  In such melt spinning, first, a polyester polymer is discharged from the spinneret 1, and this is cooled and solidified by the annular cooling device 2 to form filament fibers. Next, after applying an oil agent to each fiber using the oiling device 3, each fiber is converged by the converging guide 4, and entangled by the entanglement imparting device 5 to be mixed yarn Y. Then, after applying oil to the mixed yarn Y again using the second stage oiling device 6, the mixed yarn Y is introduced into the take-up device 8 through the take-up rollers 7, 7 ', and the take-up speed 2500 to 500 is introduced. Scrape at 4000 m / min.

  EXAMPLES Next, although an Example demonstrates this invention concretely, this invention is not limited to these. Each characteristic value was evaluated as follows.

(1) Carboxyl end group concentration 0.1 g of mixed yarn was dissolved in 10 ml of benzine alcohol, 10 ml of chloroform was added to this solution, and then titrated with a 1/10 N potassium hydroxide benzyl alcohol solution.

(2) Single yarn fineness of each fiber group After the mixed yarn is cut to about 10 cm, it is split, and all single yarn finenesses are measured using DENII COMPUTER DC-11 manufactured by Search Corp. Separately, an average value was obtained and used as the single yarn fineness of each group.

(3) Spinnability of blended yarn The yarn was spun for 12 hours using 12 spindles, and during this period, the spinnability of the blended yarn was evaluated in the following three stages from the number of yarn breakage from spinning to winding and the package defect rate. . When the evaluation was different between the number of yarn breakage and the package defect rate, the lower evaluation was adopted.

Package defect rate (%) = (number of defective packages / total number of packages) × 100
◎: Number of times of thread breakage is 0 to 2 times, package defect rate is less than 1% ○: Number of times of yarn breakage is 3 to 5 times, Package defect rate is 1% to less than 4% ×: Number of yarn breakage times is 6 times or more, Package defect rate is 4% or more

(4) Moist heat resistance of blended yarn Stretch false twisting was performed on the blended yarn under the conditions of a draw ratio of 1.4, a heat treatment temperature of 160 ° C, and a twist number of 3670 T / M using a draw false twisting machine. The processed yarn was dyed and dyed in a 30 cm cylinder. Then, the operation of washing the tubular knitted fabric at 100 ° C. for 30 minutes using a washing machine and drying it was repeated 20 times. Thereafter, the blended yarn was taken out from the tubular knitted fabric, and the moisture and heat resistance of the blended yarn was evaluated in the following four stages from the number of fluff generated on the surface.

A: Almost no deterioration of yarn (0 to 2 fluffs / m)
○: Some deterioration of the yarn is observed (number of fluff 3 to 5 / m)
Δ: Deterioration of yarn is observed (number of fluff 6-9 pieces / m)
X: Deterioration of the yarn is remarkable (number of fluff 10 / m or more)

(5) Textile color tone of woven and knitted fabrics The process of dyeing the mixed yarn with a 30cm tube knitting and dyeing, washing the tube knitted fabric obtained using a washing machine at 100 ° C for 30 minutes and then drying is repeated 20 times. The texture color tone of the woven or knitted fabric was evaluated in the following four stages by comparing the texture color tone of the tubular knitted fabric before and after the work.

(Double-circle): A texture color tone has hardly changed before work.
○: The texture color is slightly inferior to that before the work.
Δ: The texture color is inferior to that before the work.
×: The texture color is considerably inferior to that before the work.

Example 1
A chiller of terephthalic acid and ethylene glycol having a molar ratio of 1 / 1.6 is continuously supplied to an esterification reaction vessel in which bis (β-hydroxyethyl) terephthalate and its low polymer (BHET) are present, and the temperature is 250 ° C. The esterification reaction was carried out under the conditions of a pressure of 0.05 kg / cm ² and a residence time of 8 hours, and BHET having an esterification reaction rate of 95% was continuously obtained. Transport this BHET50kg the polymerization vessel, and heated to 270 ° C., and 1.0 × ^{10 -4} mol of antimony trioxide with respect to the acid content of 1 mol of constituting the polyester to acid components 1 mole constituting the polyester acid Cobalt was added at 0.2 × 10 ⁻⁴ mol and 0.5 × 10 ⁻⁴ mol of triethyl phosphate with respect to 1 mol of acid content constituting the polyester. Thereafter, the pressure was gradually reduced, and a polycondensation reaction (melt polymerization) was performed at 270 ° C. under a reduced pressure of 0.1 torr for 3.5 hours to obtain a polyester chip having an intrinsic viscosity of 0.64. After this is dried by a conventional method, the chip is supplied to a melt spinning machine, and the spinning has the shape shown in FIGS. 2 (a) to (d) and 44 spinning holes of four sizes. Using the die, melt spinning was performed at a spinning temperature of 290 ° C. and a discharge rate of 29.4 g / min. Then, it cooled and solidified with the cyclic | annular cooling device, the oil agent was provided to the fiber using the oiling device located below, and after converging with the converging guide 4, it was entangled to the mixed yarn with the entanglement applying device. Then, after applying oil to the blended yarn again by the second stage oiling device, it was wound up through a take-up roller at a take-up speed of 3000 m / min, and a 100 dtex 44f semi-undrawn yarn (the desired heterogeneity and different-degree mix yarn). )

(Examples 2 and 3)
The same procedure as in Example 1 was conducted except that the single yarn fineness of the fiber groups A and B and the ratio of the number of single yarns of each fiber group in the entire mixed yarn and the carboxyl group end group concentration were changed as shown in Table 1. A heterogeneous and different fineness mixed yarn was obtained.

(Comparative Examples 1-4)
Melt polymerization is performed using terephthalic acid and ethylene glycol by a general method to obtain a polyester chip having an intrinsic viscosity (measured at a temperature of 20 ° C. using an equimolar mixture of phenol and ethane tetrachloride as a solvent) at 0.68. It was. And after drying this by a conventional method, the spinning temperature is set to 300 ° C., and the single yarn fineness of the fiber groups A and B and the ratio of the number of single yarns of each fiber group in the entire mixed yarn, and the carboxyl group Except for changing the end group concentration as shown in Table 1, the same procedure as in Example 1 was carried out to obtain a heterogeneous and different fineness mixed yarn. In Comparative Examples 1 and 2, a spinneret having the shape shown in FIG. 3 was used as the spinneret used when spinning the fiber group B.

  The characteristic values of the mixed yarns obtained in the above examples and comparative examples are shown in Table 1 below.

  As is clear from Table 1, the mixed yarns in Examples 1 to 3 can impart a dry feeling, a soft feeling, and a swell feeling to the woven or knitted fabric, and there is no particular problem in terms of yarn-making property and heat and humidity resistance. It was a thing.

  On the other hand, since the mixed yarn in Comparative Example 1 has a fine single yarn fineness of the fiber group A, the woven or knitted fabric lacks a tight feeling of tension. At the same time, the single yarn fineness difference between the two fiber groups was small, and the woven or knitted fabric had a slimy feeling. In Comparative Example 2, since the ratio of the number of single yarns in the fiber group B was large, the woven or knitted fabric was excellent in softness but poor in dryness. In Comparative Example 3, since the ratio of the number of single yarns constituting the fiber group A is large, the dry feeling is excessively emphasized in the woven or knitted fabric, and rather a coarse and rigid feeling is generated, and the texture color tone evaluation is also inferior. In Comparative Example 4, since the single yarn fineness of the fiber group A was thin and the single yarn fineness difference between the two fiber groups was small, the knitted or knitted fabric lacked a tightness and a slimy feeling.

  Moreover, in the mixed yarn in Comparative Examples 2-4, since the carboxyl end group density | concentration exceeds predetermined amount, deterioration of the knitted fabric advanced by wet heat processing, and it appeared as the fluff of the mixed fiber surface Was confirmed.

1 is a schematic diagram showing an example of a melt spinning apparatus that can be preferably employed in the present invention. It is a schematic diagram which shows an example of the cross-sectional shape of the spinneret which can be employ | adopted preferably in this invention. It is a schematic diagram which shows an example of the cross-sectional shape of the spinneret used when spinning an irregular cross-section fiber.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Spinneret 2 Annular cooling device 3 Oiling device 4 Converging guide 5 Entangling device 6 Oiling device 7, 7 'Take-off roller 8 Cutting device Y Blended yarn

Claims (1)

90% by mole or more of all repeating units is a mixed yarn comprising fibers formed from a polyester polymer of ethylene terephthalate, and the polyester polymer has a terminal carboxyl group end group concentration of 25 eq / t or less, The mixed yarn includes a fiber group A having a single yarn fineness of 3 dtex or more and a fiber group B having a single yarn fineness of 2 dtex or less, and the ratio of the number of single yarns of the fiber group A to the entire mixed yarn is 5 to 50%. The ratio of the number of single yarns of the fiber group B is 20 to 60%, the fiber group A includes fibers having a non-rotation target cross-sectional shape having a flat trunk portion and a protrusion as a cross-sectional shape, and the fiber group B has a cross-sectional shape. A heterogeneous heterogeneity mixed yarn comprising fibers having a round cross-sectional shape.