JP2005273116A - Conjugate fiber and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a crimp forming conjugate fiber excellent in stretchability and improved in product stability in post processing and a method for producing the same. <P>SOLUTION: The crimp forming conjugate fiber is a side-by-side or an excentric sheath-core type fiber remarkably stable for heat hysteresis, tension and the like given to the fiber in knitting, weaving and dyeing processing. The stretchable conjugate fiber produced by the invention is remarkably excellent in product stability during post processing as the fiber has high stretchability with ≥40% rate of crimp stretch, ≥70% elastic recovery factor, ≥155°C maximum temperature of thermal contraction stress and ≤3% iron shrinkage of the finally processed fabric. Different fiber forming polymers having 5,000-70,000 number average molecular weight difference and 1.5-2.5 molecular weight distribution index in each fiber are used as the polymer.in the invention. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a crimp-forming composite fiber having excellent stretchability and improved product stability during post-processing, and a method for producing the same, and more particularly, a crimp extension ratio of 40% or more, elasticity Side-by-side or eccentricity that is very stable to the thermal history and tension applied to the fibers during weaving and dyeing because the maximum temperature of heat shrinkage stress is 155 ° C or higher while having a high stretchability of 70% or higher. The present invention relates to a sheath-core type crimp-forming composite fiber and a method for producing the same.

  Patent Document 1 discloses a method using two types of polyethylene terephthalate (PET) having an intrinsic viscosity difference. Patent Documents 2 and 3 disclose a method for producing a polyester-based latent crimp-expressing fiber using general polyethylene terephthalate and highly shrinkable copolymer polyethylene terephthalate. In addition, Patent Document 4 and Patent Document 5 also present a method of using polytrimethylene terephthalate (PTT) or polybutylene terephthalate (PBT) having stretch properties in polyethylene terephthalate (PET).

  However, in the case of a stretchable composite fiber with a crimp produced by the production method described in the above-mentioned patent, the reduction of the fabric is usually 10% or more in the post-process, and even after the final processing. In the case of ironing, 3% or more of the shape deformation occurs, so that it is difficult to set conditions during product processing, and it is difficult to stabilize the dimensions of the sewn product.

  In general, textile products are subjected to a heat history of 130 to 190 ° C. and a tension of about 1 to 2 g / d during weaving / dyeing, thermal setting and ironing. Is an important factor that determines the quality of a product. Therefore, in order to minimize the deformation of the product when ironing, it is necessary to solve the problem of the prior art in which a deformation of 3% or more occurs during ironing.

  The inventors of the present invention have recognized that the shrinkage rate generated when ironing the processed fabric is closely related to the maximum heat shrinkage stress temperature of the fiber. It was found that the shrinkage rate during ironing was 3% or less, and the shape stability of the final product was excellent.

  Patent Document 6 describes a stretchable composite fiber having a heat shrinkage stress maximum temperature of 130 ° C. or less and a heat shrinkage stress maximum pick value of 0.20 cN / dtex or more. There is no mention of the effect that will be affected. In general, stretchable fiber products are more sensitive to heat history and tension during weaving / dyeing, heat setting and ironing, compared to general fibers, and thus form stability becomes a problem. This has an important influence on the dyeing uniformity of the product, the dyed fabric and the dimensional stability of the sewn product. Generally, if the iron shrinkage ratio is 3% or more, the product quality is poor. To be judged.

In addition, patents relating to conventional stretchable composite fibers are generally only proposed for composite spinning with different polyester polymers. Regarding the physical properties of composite fibers based on the molecular weight of the polymers of the different polymers that make up the composite fibers. Not mentioned. Patent Document 4 mentions a change in physical properties due to a change in viscosity with respect to polyethylene terephthalate (PET), polytrimethylene terephthalate (PTT), and modified PET, PTT. There is no mention of the molecular weight of the different macromolecules that make up. Of course, the molecular weight can be estimated from the relationship between the viscosity and the molecular weight by the Mark-Hawink equation, but information on the molecular weight distribution cannot be obtained. Patent Document 4 refers to a stretchable composite fiber using a polyester polymer having two different viscosity differences between PTT or between PTT-PET and PTT-PBT. There is no information on molecular weight and molecular weight distribution. Therefore, the present inventors have determined that the molecular weight, molecular weight distribution, and stretching heat setting temperature of the polyester polymer having two different viscosity differences are the maximum heat shrinkage stress temperature of the fiber, the stretching property, and the ironing of the processed fabric. It was discovered that this is a factor affecting the shrinkage rate, and the optimal molecular weight and molecular weight distribution of the bipolymer were designed.
Japanese Patent Laid-Open No. 10-72732 JP 2000-328378 A Japanese Patent Laid-Open No. 9-41234 U.S. Pat. No. 3,671,379 Japanese Patent Laid-Open No. 11-189923 JP 2002-54030 A

  The present invention provides a crimp-forming composite fiber having excellent stretchability and excellent product form stability, and a method for producing the same, using a fiber-forming polymer that can be used industrially. For the purpose.

  Therefore, the present inventors have conducted extensive studies to satisfy such a purpose, and as a result, among the fiber-forming polymers, the number average molecular weight difference is 5,000 to 70,000, and each molecular weight distribution index. It can be seen that the composite fibers produced using different fiber-forming polymers having a 1.5 to 2.5 have excellent stretchability, and each polymer has a number average molecular weight of 10, The first component fiber-forming polymer having a molecular weight distribution index of 1.5 to 2.5, a number average molecular weight of 15,000 to 90,000, and a molecular weight distribution index of 1.5 to 2 .5 of the second component fiber-forming polymer has been found to be the optimal polymer for minimizing stretch properties and morphological deformation during ironing. When the difference in the number average molecular weight of the polymers is 5.000 or less, it is difficult to express the crimp elongation rate and elastic recovery rate of the raw yarn. When the difference is 70,000 or more, the molecular weight is decreased by increasing the spinning temperature. The effect cannot be expected due to deepening, and it is difficult to ensure processability due to the generation of bent yarns during spinning, and the iron shrinkage rate becomes poor due to the increase in shrinkage effect due to high molecular weight. Also, the molecular weight distribution index is limited to 1.5 to 2.5 if the molecular weight distribution index is less than 1.5, the molecular weight distribution becomes too uniform, and the self-plasticizing of low molecular weight substances ) Is a minor role and is likely to cause problems in the process. When the molecular weight distribution index is greater than 2.5, the molecular weight distribution increases and the effect of mixing several polymers is exhibited. Therefore, when the heat setting temperature is raised to a certain level or more, the phenomenon of plasticization occurs in the hot plate, and it becomes difficult to ultimately increase the maximum temperature of the heat shrinkage stress, and the morphological stability and elasticity are reduced. A problem occurs.

  Further, in the case of a polymer having a high molecular weight, the decrease in the molecular weight due to the inter-spin thermal decomposition is serious and the molecular weight distribution is also widened. Therefore, when the residence time of the polymer melt in the spin pack is minimized to within 5 minutes, It has been found that the expression of physical properties and functionality due to characteristics can be maximized.

  As another aspect of the present invention, in the case of a stretchable composite fiber by melt spinning, the reduction of the fabric is usually 10% or more in the post-process, and the shape deformation of 3% or more occurs after the final processing. It was found that it was difficult to set the conditions when processing the product, and it was difficult to stabilize the dimensions of the sewing product. General textile products usually receive a heat history of 130-190 ° C and a tension of about 1-2 g / d during weaving / dyeing, thermal setting and ironing. Must be within ± 3% based on iron shrinkage. It has been discovered that such characteristics are closely related to the maximum heat shrinkage stress temperature of the fiber, and when the maximum heat shrinkage stress temperature is increased to a level of 155 ° C or higher, the shape stability of the stretchable product is excellent. I found out that

  The stretchable composite fiber produced according to the present invention has a high stretchability of 40% or more of crimp extension and 70% or more of elastic recovery rate, and the maximum temperature of heat shrinkage stress is 155 ° C or more. The iron shrinkage of the processed fabric is 3% or less, and the product stability during post-processing is very excellent. In addition, the composite fiber produced by the present invention minimizes the decrease in molecular weight, raw yarn properties and stretchability by reducing the residence time of the interspinning pack polymer, and heat shrinkage compared to existing raw yarns. Improves the maximum stress temperature to improve product stability during the post-process, and is excellent in the strength and elasticity of the raw yarn, so it can be used in various applications such as woven fabrics, weft knitting and warp knitting. can do.

  In the present invention, the maximum temperature of the heat shrinkage stress of the fiber obtained by using a fiber-forming polymer capable of two types of melt spinning is 155 ° C. or higher, and the crimp elongation after treatment with no-load boiling water is 40. %, An elastic recovery rate is 70% or more, and a stretchable composite fiber having excellent shape stability, in which an iron shrinkage rate of a processed fabric produced therefrom is 3% or less.

  The one kind of polymer is polyethylene terephthalate, the number average molecular weight is 10,000 to 20,000, the molecular weight distribution index is 1.5 to 2.5, and the other one kind of polymer is polytriene. Methylene terephthalate having a number average molecular weight of 15,000 to 90,000, a molecular weight distribution index of 1.5 to 2.5, and a difference in number average molecular weight of the two polymers of 5,000 to 70,000. It is a feature.

  One kind of polymer is polyethylene terephthalate, the number average molecular weight is 10,000 to 20,000, the molecular weight distribution index is 1.5 to 2.5, and the other one kind of polymer is polyethylene terephthalate. A polybutylene terephthalate or polyethylene terephthalate copolymer having a number average molecular weight of 15,000 to 90,000, a molecular weight distribution index of 1.5 to 2.5, and a difference in number average molecular weight of the two polymers of 5,000 to It is characteristic that it is 70,000.

  The cross-sectional shape is preferably a side-by-side type or an eccentric core-sheath (Sheath-Core) type.

  Moreover, it is preferable that the diameter of crimp is 8 mm or less.

In the present invention, (A) one kind of polymer is polyethylene terephthalate, the number average molecular weight is 10,000 to 20,000, the molecular weight distribution index is 1.5 to 2.5, The polymer is polytrimethylene terephthalate, the number average molecular weight is 15,000-90,000, the process of melting two kinds of polyesters having a molecular weight distribution index of 1.5-2.5,
(B) After passing the melt through the spin pack so that the residence time in the spin pack is 5 minutes or less, side-by-side type or eccentric core-sheath type at a spinning speed of 2,200 to 5,000 m / min An elastic composite fiber produced by a method comprising the steps of: taking the composite yarn of (С); and (С) drawing the drawn composite yarn at a temperature of 85 to 95 ° C. and heat-setting at a temperature of 160 to 220 ° C. A manufacturing method is provided.

  In the present invention, (A) one kind of polymer is polyethylene terephthalate, the number average molecular weight is 10,000 to 20,000, the molecular weight distribution index is 1.5 to 2.5, The polymer is polyethylene terephthalate, polybutylene terephthalate or polyethylene terephthalate copolymer, which melts two polyesters having a number average molecular weight of 15,000 to 90,000 and a molecular weight distribution index of 1.5 to 2.5. And (B) side by side type or eccentricity at a spinning speed of 2,200 to 5,000 m / min after passing the melt through the spin pack so that the residence time in the spin pack is 5 minutes or less. A method comprising drawing a core-sheath type composite yarn, and (С) drawing the drawn composite yarn at a temperature of 85 to 95 ° C. and heat-setting at a temperature of 160 to 220 ° C. Thus to provide a method for producing a stretchable composite fibers produced.

  The production method of the stretchable conjugate fiber of the present invention is preferably produced by a partial orientation-stretching / false twist method or a direct spinning method.

  The stretching temperature is preferably 85 to 95 ° C, and the heat setting temperature is preferably 160 to 220 ° C.

  The present invention also provides a processed yarn having a twist number (TM: twist / meter) of 150 to 2,000, which is produced from the stretchable conjugate fiber.

  In addition, the present invention provides a mixed yarn in which the elastic composite fiber is mixed with an original yarn having a high shrinkage characteristic and having an elongation of 50% or more and a boiling water shrinkage of 15% or more.

  Moreover, this invention provides the fabric containing the said elastic composite fiber.

  In order to produce a composite fiber having elasticity for minimizing morphological deformation during ironing, the difference in number average molecular weight is 5,000 to 70,000, and each molecular weight distribution index is 1.5 to 2. It is preferable to use different fiber-forming polymers that are .5, and with respect to the characteristics of each polymer, its analysis method, and production method, the polymer material and the spinning process using this will be described as follows. .

  (1) Characteristics of different fiber-forming polymers having a number average molecular weight difference of 5,000 to 70,000 and a molecular weight distribution index of 1.5 to 2.5, and an analysis method thereof

  The two types of polymers used in the present invention have a number average molecular weight difference of 5,000 to 70,000 and a molecular weight distribution index of 1.5 to 2.5. The number average molecular weight of one component must be 10,000 to 20,000, the molecular weight distribution index must be 1.5 to 2.5, the number average molecular weight of the other component is 15,000 to 90,000, The molecular weight distribution index must be between 1.5 and 2.5.

  As the polymer used, industrially utilized polymers such as polyester and nylon, and modified polymers thereof can be used. In addition, polymers such as polyurethane and polyacrylonitrile can also be used, but these are difficult to be actually applied because of the problem that they are decomposed in a process at a high temperature. Polymers such as polyester and nylon and these modified polymers can be used. Specific examples thereof include polyesters typified by polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, and isophthalic acid. These copolymers modified with (Isophthalic acid), polyethylene glycol, etc., and nylons represented by nylon 6, nylon 66, nylon 46, etc., and m-xylene diamine, etc. In addition, a polymer that can be melt-molded, such as these copolymers, can be mentioned.

  The number average molecular weight of one polymer must be 10,000 to 20,000, the molecular weight distribution index must be 1.5 to 2.5, and the number average molecular weight of the other polymer is 15,000 to 90,000. The fact that the molecular weight distribution index must be 1.5 to 2.5 does not mean that a polymer of one component and another component has been established, for example, the number average molecular weight of one polymer Is 10,000 to 20,000 and the molecular weight distribution index is 1.5 to 2.5, the number average molecular weight of the other polymer is 15,000 to 90,000 and the molecular weight distribution index is 1.5. That means it should be ~ 2.5. More specifically, for example, if the polymer having a number average molecular weight of 10,000 to 20,000 and a molecular weight distribution index of 1.5 to 2.5 is polyethylene terephthalate, the number average molecular weight is 15,000. The polymer having a molecular weight distribution index of 1.5 to 2.5 may be polytrimethylene terephthalate, polybutylene terephthalate, nylon 6 or the same polyethylene terephthalate. is there. That is, if the difference in the number average molecular weight and the molecular weight distribution index determined by the gel permeation chromatography method are within the range limited by the present invention, it means that it does not matter whether the types of polymers are the same or different. Therefore, in the present invention, a polymer having a number average molecular weight of 10,000 to 20,000 and a molecular weight distribution index of 1.5 to 2.5 is referred to as a low molecular weight polymer, and the number average molecular weight is 15,000 to A polymer having 90,000 and a molecular weight distribution index of 1.5 to 2.5 is referred to as a high molecular weight polymer.

  These polymers are produced from generally known bulk polymerization, solution polymerization, interfacial polymerization, etc., and the polymer targeted by the present invention can be used by any of these methods, and is particularly preferred. Among the bulk polymerization methods, a polymer produced from melt polymerization or solid polymerization is advantageous in terms of production cost.

  In the present invention, the reason why the minimum molecular weight of the low molecular weight polymer is 10,000 and the maximum molecular weight of the high molecular weight polymer is 90,000 is as follows. It is not difficult as a polymerization method itself to produce a polymer having a molecular weight of less than 10,000. However, in order to fiberize using this polymer, it is advantageous to be in the form of chips (or pellets). If the molecular weight is less than 10,000, it is too fragile when manufactured into a chip, which makes it difficult to manufacture a chip having a uniform shape. When the molecular weight exceeds 90,000, it is difficult to produce by the melt polymerization method or the solid polymerization method, and even if this is possible, the time is too long and not only economically disadvantageous, but also spinning. Since the temperature must be increased excessively, the effect cannot be expected due to the decrease in molecular weight due to thermal decomposition.

  Also, the molecular weight distribution index is limited to 1.5 to 2.5 if the molecular weight distribution index is less than 1.5, the molecular weight distribution becomes too uniform, and the self-plasticizing of low molecular weight substances ) Is a minor role and is likely to cause problems in the process. When the molecular weight distribution index is greater than 2.5, the molecular weight distribution increases and the effect of mixing several polymers is exhibited. Therefore, when the heat setting temperature is raised to a certain level or more, a phenomenon of plasticization occurs on the hot plate, ultimately making it difficult to increase the maximum temperature of the heat shrinkage stress, resulting in a decrease in form stability and elasticity. Therefore, it is not preferable.

  In the present invention, the number average molecular weight and molecular weight distribution index are obtained by dissolving a polymer or a produced composite fiber in hexafluoroisopropyl alcohol (HFIP) and using a high-temperature GPC set of Waters, USA. The number average molecular weight (Mn) and weight average molecular weight (Mw) were measured using polystyrene as a reference substance, and the molecular weight distribution index (PDI) was calculated from the following formula: Was converted.

  (2) Manufacture of composite fiber

  The spinning temperature of the polymer during melt spinning for producing the composite fiber was 20 to 70 ° C. higher than the melting temperature of each polymer. If the spinning temperature of the polymer is not higher than the melting temperature of the polymer by 20 ° C. or more, it is melted non-uniformly, the pressure in the extruder becomes too high, and the workability decreases, and the physical properties of the composite fiber produced This is not preferable because problems such as non-uniformity occur. On the other hand, if the spinning temperature of the polymer is higher than 70 ° C. compared with the melting temperature of the polymer, the flowability of the polymer is improved, but problems such as thermal decomposition of the polymer occur, which is not preferable.

  Eccentric core-sheath type in which each discharged fibrous polymer is bonded directly under the spinneret to obtain a composite fiber having a side-by-side cross section, or the polymer is bonded while passing through the distribution plate and entering the spinneret. It is possible to produce cross-section fibers.

  In addition, in the case of a polymer having a high molecular weight, the present inventor has a serious decrease in molecular weight due to thermal decomposition during spinning, and the molecular weight distribution is also widened. Therefore, the residence time of the polymer melt in the spinning pack is 5 minutes or less. It was found that the expression of physical properties and functionality due to the above characteristics can be maximized by minimization.

  The obtained conjugate fiber can be made into a fiber by a partially oriented yarn-drawing / false twisting method or a direct spinning method used for production of a normal polyester conjugate fiber.

  The core technical component of the present invention is to set the spinning speed to 2,200-5,500 m / min. This is not only economically disadvantageous when spinning at a spinning speed of 2,200 m / min or less, because the amount of polymer melt discharged by low-speed spinning is reduced, but also the stretch ratio is improved during stretching. This is because an increase in the heat shrinkage rate caused by the iron ultimately causes the shrinkage rate during ironing to be 3% or more, so that the morphological stability of the final product with respect to heat drops sharply. In general, fibers having crystals formed by high-stretch drawing at a low spinning speed exhibit a high shrinkage ratio with respect to heat. In addition, when spinning at a spinning speed of 5,000 m / min or more, the spinning process is deteriorated due to a decrease in spinnability due to too different thermal and physical properties between two different molecular weight polymers. Therefore, it is not preferable.

  In the present invention, as another core technical component, when manufacturing by a partial orientation-stretching / false twisting method or a direct spinning method, the stretching temperature is 85 to 95 ° C, and the heat setting temperature is 160 to 220 ° C. It is characterized by that. When the stretching temperature is 85 ° C. or lower, uniform stretching is difficult, and when it is 95 ° C. or higher, the degree of plasticization by heat becomes severe, and the inter-spinning process properties and the physical properties become unstable. When the heat setting temperature is 160 ° C. or less, the maximum temperature of heat shrinkage stress is 155 ° C. or less, and when the final processed fabric is ironed, high shrinkage of the fabric occurs, resulting in uneven shape stability of the product. This is not preferable because the quality of the final product is lowered. On the other hand, when the temperature is 220 ° C. or higher, plasticization becomes severe, and process properties and various physical properties are weakened.

  In the case of stretchable composite fibers in which conventional crimps are expressed, the reduction of the fabric in the post-process is usually 10% or more, and after the final processing, 3% or more of the shape deformation occurs during ironing, and the product processing In this case, there are problems that it is difficult to set the conditions and it is difficult to stabilize the dimensions of the sewn product. Common textile products usually receive a heat history of 130-190 ° C and a tension of 1-2 g / d during weaving / dyeing, heat setting and ironing. The present inventors have found that there is a close relationship with the maximum stress temperature, and it has been found that when the maximum heat shrinkage stress temperature is increased to 155 ° C. or higher, the shape stability of the product becomes excellent.

  Table 1 shows the physical properties and functionality of the fibers according to the yarn production conditions of the present invention.

  Hereinafter, the present invention will be described in more detail based on the following examples. The following examples merely illustrate the invention and do not limit the scope of the invention.

  First, an evaluation standard of physical properties of a bonded composite fiber manufactured by the method according to the present invention and a measuring method thereof will be described.

(A) Measurement of thermal shrinkage stress It measured using the thermal stress tester of Kanebo with initial load 0.5g / d and the temperature increase rate of 2.2 degreeC / sec.

(B) Measurement of number average molecular weight and molecular weight distribution A polymer and a produced composite fiber are dissolved in hexafluoroisopropyl alcohol (HFIP), and a high-temperature GPC set of Waters, USA is used. Measure the number average molecular weight (Mn) and weight average molecular weight (Mw) using Polystyrene as a reference substance, and calculate the molecular weight distribution index (PDI) from the following formula: Converted.

(C) Measurement of Crimp Elongation Rate and Elastic Recovery Rate In order to measure the crimp extension rate and elastic recovery rate, which are physical properties of the crimp-forming composite fibers produced in the examples, the following procedure was performed.

The fiber bundle was immersed in boiling water for 30 minutes under no load, and then dried at room temperature. After applying a load of 0.1 g / d for 2 minutes, the sample was deweighted and allowed to stand for 10 minutes. The sample after the above stage was allowed to stand for 2 minutes under a load of 0.002 g / d, and then the length (L ₁ ) at that time was measured. A load of 0.1 g / d was applied to the sample, and after 2 minutes, the length (L ₂ ) was measured. Then, the load (0.1 g / d) was removed, and after 2 minutes, the length (L ₃ ) at that time was measured. The crimp extension rate and elastic recovery rate were calculated by the following formula.

Crimp elongation (%) = [(L ₂ −L ₁ ) / L ₂ ] × 100

Elastic recovery rate (%) = [(L ₂ −L ₃ ) / L ₂ −L ₁ )] × 100

(D) Measurement of iron shrinkage rate The iron shrinkage rate was measured based on KS K 0558-2001, A-1 (dry heat iron method) after weaving and dyeing by a normal method.

(E) Measurement of crimp diameter After 20 fibers were randomly sampled and the diameter of the crimp was measured with an optical microscope under its own weight, the average value was obtained.

(Example 1)
In producing crimp-forming composite fibers, polyethylene terephthalate having a number average molecular weight (Mn) of 12,632 and a molecular weight distribution index (PDI) of 2.2, a number average molecular weight (Mn) of 19,149, a molecular weight distribution index (PDI) of The polytrimethylene terephthalate of 2.4 is used in the eccentric core-sheath section of FIG. 2- (d) at a weight ratio of 5: 5 using a conventional melt-combined spinning equipment, spinning temperature is 270 ° C., spinning speed is 2 , 200 m / min, and the residence time in the pack was set to 4 minutes, and a polyester composite fiber was produced so that the single yarn fineness was 3.4 denier. The conjugate fiber obtained by spinning / winding was drawn using a separate drawing device to produce a crimp-expressing elastic conjugate fiber having a single-denier fineness of 2.1 denier with a spring-shaped crimp. . The stretching ratio at the time of stretching was 1.75, the stretching temperature was 85 ° C., and the heat setting temperature was 160 ° C. The results are shown in Table 1. In the raw yarn and woven fabric, very good stretch properties and shape stability were exhibited.

(Example 2)
In producing crimp-forming composite fibers, polyethylene terephthalate having a number average molecular weight (Mn) of 15,385 and a molecular weight distribution index (PDI) of 2.1, a number average molecular weight (Mn) of 33,522, a molecular weight distribution index (PDI) The polytrimethylene terephthalate of 2.1 was used in a side-by-side cross section of FIG. 2- (a) using a conventional melt compound spinning equipment at a weight ratio of 5: 5, spinning temperature of 275 ° C., spinning speed of 2,600 m / s. And a residence time in the pack of 4 minutes, a polyester composite fiber was produced so that the single yarn fineness was 3.4 denier. The conjugate fiber obtained by spinning / winding was drawn using a separate drawing device to produce a crimp-expressing elastic conjugate fiber having a single-denier fineness of 2.1 denier with a spring-shaped crimp. . The drawing ratio was 1.70, the drawing temperature was 90 ° C., and the heat setting temperature was 180 ° C. The results are shown in Table 1. In the raw yarn and woven fabric, very good stretch properties and shape stability were exhibited.

(Example 3)
In producing crimp-forming composite fibers, polyethylene terephthalate having a number average molecular weight (Mn) of 18,211 and a molecular weight distribution index (PDI) of 2.1, a number average molecular weight (Mn) of 88,245, a molecular weight distribution index (PDI) A polytrimethylene terephthalate of 1.6 in a weight ratio of 5: 5 using a conventional melt-combined spinning equipment, with a side-by-side cross section of FIG. 2- (a), a spinning temperature of 285 ° C., a spinning speed of 3,800 m / And a residence time in the pack of 4 minutes, and a polyester composite fiber was produced by a direct spinning method so that the single yarn fineness was 3.4 denier. The conjugate fiber obtained by spinning / winding was drawn using a separate drawing device to produce a crimp-expressing elastic conjugate fiber having a single-denier fineness of 2.1 denier with a spring-shaped crimp. . The drawing ratio at the time of direct spinning was 3.7, the drawing temperature was 90 ° C., and the heat setting temperature was 170 ° C. The results are shown in Table 1. In the raw yarn and woven fabric, very good stretch properties and shape stability were exhibited.

Example 4
In producing crimp-forming composite fibers, polyethylene terephthalate having a number average molecular weight (Mn) of 12,632 and a molecular weight distribution index (PDI) of 2.2, a number average molecular weight (Mn) of 25,984, a molecular weight distribution index (PDI) 2.2 Polyethylene terephthalate having a weight ratio of 5: 5 by using a conventional melt-combined spinning equipment, a spinning temperature of 285 ° C., a spinning speed of 2,600 m / min, in a side-by-side cross section of FIG. A polyester composite fiber was produced by setting the residence time in the pack to 4 minutes so that the single yarn fineness was 4.6 denier. The composite fiber obtained by spinning / winding was stretched using a separate stretching device to produce a crimp-expressing stretchable composite fiber having a single-fiber fineness of 2.8 denier and provided with a spring-shaped crimp. . The drawing ratio was 1.70, the drawing temperature was 90 ° C., and the heat setting temperature was 160 ° C. The results are shown in Table 1. In the raw yarn and woven fabric, very good stretch properties and shape stability were exhibited.

(Example 5)
In producing crimp-forming composite fibers, polyethylene terephthalate having a number average molecular weight (Mn) of 13,691 and a molecular weight distribution index (PDI) of 2.2, a number average molecular weight (Mn) of 25,984, a molecular weight distribution index (PDI) The polyethylene terephthalate of 2.2 was used in the eccentric core-sheath section of Fig. 2- (d) at a weight ratio of 5: 5 with a conventional melt compound spinning equipment, spinning temperature 285 ° C, spinning speed 2,600m. The polyester composite fiber was manufactured so that the single yarn fineness was 6.9 deniers at a setting time of 4 minutes per minute. The conjugate fiber obtained by spinning / winding was drawn using a separate drawing device to produce a crimp expression type stretchable conjugate fiber having a single-denier fineness of 4.2 denier and provided with a spring-shaped crimp. . The drawing ratio was 1.70, the drawing temperature was 90 ° C., and the heat setting temperature was 160 ° C. The results are shown in Table 1. In the raw yarn and woven fabric, very good stretch properties and shape stability were exhibited.

(Example 6)
In producing crimp-forming composite fibers, polyethylene terephthalate having a number average molecular weight (Mn) of 15,385 and a molecular weight distribution index (PDI) of 2.2, a number average molecular weight (Mn) of 31,300, a molecular weight distribution index (PDI) 2.1 Polyethylene terephthalate of 2.1 in a weight ratio of 6: 4 using a conventional melt compound spinning equipment, with a spinning temperature of 295 ° C., spinning speed of 2,400 m / min, in a side-by-side cross section of FIG. A polyester composite fiber was produced so that the residence time in the pack was set to 4 minutes and the single yarn fineness was 3.4 denier. The conjugate fiber obtained by spinning / winding was drawn using a separate drawing device to produce a crimp-expressing elastic conjugate fiber having a single-denier fineness of 2.1 denier with a spring-shaped crimp. . The stretching ratio during stretching was 1.62, the stretching temperature was 90 ° C., and the heat setting temperature was 220 ° C. The results are shown in Table 1. In the raw yarn and woven fabric, very good stretch properties and shape stability were exhibited.

(Example 7)
In producing crimp-forming composite fibers, polyethylene terephthalate having a number average molecular weight (Mn) of 15,385 and a molecular weight distribution index (PDI) of 2.2, a number average molecular weight (Mn) of 23,300, a molecular weight distribution index (PDI) Polyethylene terephthalate substituted with 10 mol% of isophthalic acid of 2.2 is used in a side-by-side cross section of FIG. 2- (a) at a weight ratio of 5: 5 and a spinning temperature of 275 ° C. Polyester composite fibers were produced at a spinning speed of 2,900 m / min and a residence time in the pack of 4 minutes so that the single yarn fineness was 3.4 denier. The conjugate fiber obtained by spinning / winding was drawn using a separate drawing device to produce a crimp-expressing elastic conjugate fiber having a single-denier fineness of 2.1 denier with a spring-shaped crimp. . The stretching ratio during stretching was 1.67, the stretching temperature was 90 ° C., and the heat setting temperature was 180 ° C. The results are shown in Table 1. In the raw yarn and woven fabric, very good stretch properties and shape stability were exhibited.

(Example 8)
In producing crimp-forming composite fibers, polyethylene terephthalate having a number average molecular weight (Mn) of 15,385 and a molecular weight distribution index (PDI) of 2.2, a number average molecular weight (Mn) of 33,691, and a molecular weight distribution index (PDI) The polybutylene terephthalate of 2.2 was used in a side-by-side cross section of FIG. 2- (a) using a conventional melt compound spinning equipment at a weight ratio of 5: 5, spinning temperature of 275 ° C., spinning speed of 2,400 m / min. The polyester composite fiber was produced so that the residence time in the pack was set to 4 minutes and the single yarn fineness was 3.4 denier. The conjugate fiber obtained by spinning / winding was drawn using a separate drawing device to produce a crimp-expressing elastic conjugate fiber having a single-denier fineness of 2.1 denier with a spring-shaped crimp. . The stretching ratio during stretching was 1.67, the stretching temperature was 90 ° C., and the heat setting temperature was 180 ° C. The results are shown in Table 1. In the raw yarn and woven fabric, very good stretch properties and shape stability were exhibited.

(Comparative Example 1)
In producing crimp-forming composite fibers, polyethylene terephthalate having a number average molecular weight (Mn) of 12,632 and a molecular weight distribution index (PDI) of 2.2, a number average molecular weight (Mn) of 16,950, a molecular weight distribution index (PDI) The polytrimethylene terephthalate of 2.4 was used in a side-by-side cross section of FIG. 2- (a) at a weight ratio of 5: 5 using a conventional melt-combined spinning equipment, spinning temperature 270 ° C., spinning speed 2,500 m / s. And a residence time in the pack of 4 minutes, a polyester composite fiber was produced so that the single yarn fineness was 3.4 denier. The conjugate fiber obtained by spinning / winding was drawn using a separate drawing device to produce a crimp-expressing elastic conjugate fiber having a single-denier fineness of 2.1 denier with a spring-shaped crimp. . The stretching ratio at the time of stretching was 1.70, the stretching temperature was 75 ° C., and the heat setting temperature was 145 ° C. The results are shown in Table 2. Stretching properties were greatly reduced in raw yarns and woven fabrics and showed unstable morphological stability.

(Comparative Example 2)
In producing crimp-forming composite fibers, polyethylene terephthalate having a number average molecular weight (Mn) of 12,691 and a molecular weight distribution index (PDI) of 2.2, a number average molecular weight (Mn) of 24,411, and a molecular weight distribution index (PDI) of 2.7 Polytrimethylene terephthalate having a weight ratio of 5: 5 using a conventional melt-combined spinning equipment, and having an eccentric core-sheath section of FIG. 2- (d), a spinning temperature of 265 ° C., a spinning speed of 1 , 500 m / min, and the residence time in the pack was set to 8 minutes, and a polyester composite fiber was produced so that the single yarn fineness was 6.0 denier. The conjugate fiber obtained by spinning / winding was drawn using a separate drawing device to produce a crimp-expressing elastic conjugate fiber having a single-denier fineness of 2.1 denier with a spring-shaped crimp. . The stretching ratio during stretching was 2.85, the stretching temperature was 75 ° C., and the heat setting temperature was 140 ° C. The results are shown in Table 2. Stretch characteristics were slightly reduced in the raw yarn and woven fabric, and unstable morphological stability was exhibited.

(Comparative Example 3)
In producing crimp-forming composite fibers, polyethylene terephthalate having a number average molecular weight (Mn) of 15,805 and a molecular weight distribution index (PDI) of 2.6, a number average molecular weight (Mn) of 30,680, a molecular weight distribution index (PDI) of A polytrimethylene terephthalate of 2.6 is used in a side-by-side cross section of FIG. 2- (a) at a weight ratio of 5: 5, with a spinning temperature of 270 ° C., a spinning speed of 1,400 m / s. And a residence time in the pack of 8 minutes, and a polyester composite fiber was produced so that the single yarn fineness was 8.1 denier. The composite fiber obtained by spinning / winding was stretched using a separate stretching device to produce a crimp-expressing stretchable composite fiber having a single-fiber fineness of 2.8 denier and provided with a spring-shaped crimp. . The stretching ratio during stretching was 2.90, the stretching temperature was 80 ° C., and the heat setting temperature was 150 ° C. The results are shown in Table 2. Stretch characteristics were slightly reduced in the raw yarn and woven fabric, and unstable morphological stability was exhibited.

(Comparative Example 4)
In producing crimp-forming composite fibers, polyethylene terephthalate having a number average molecular weight (Mn) of 15,385 and a molecular weight distribution index (PDI) of 2.2, a number average molecular weight (Mn) of 31,292, a molecular weight distribution index (PDI) The polybutylene terephthalate of 2.8 is used at a weight ratio of 5: 5 by using a conventional melt-combined spinning equipment, and the spinning temperature is 275 ° C. and the spinning speed is 1,400 m / min. The polyester composite fiber was manufactured so that the residence time in the pack was set to 8 minutes and the single yarn fineness was 6.0 denier. The conjugate fiber obtained by spinning / winding was drawn using a separate drawing device to produce a crimp-expressing elastic conjugate fiber having a single-denier fineness of 2.1 denier with a spring-shaped crimp. . The stretching ratio at the time of stretching was 2.90, the stretching temperature was 75 ° C., and the heat setting temperature was 145 ° C. The results are shown in Table 2. Stretch characteristics were slightly reduced in the raw yarn and woven fabric, and unstable morphological stability was exhibited.

(Comparative Example 5)
In producing crimp-forming composite fibers, nylon 6 having a number average molecular weight (Mn) of 13,490 and a molecular weight distribution index (PDI) of 2.2, a number average molecular weight (Mn) of 31,290 and a molecular weight distribution index (PDI) of A polytrimethylene terephthalate of 2.8 is used in a side-by-side cross section of FIG. 2- (a) at a weight ratio of 5: 5, and a spinning temperature of 270 ° C., a spinning speed of 1,400 m / s. And a residence time in the pack of 8 minutes, and a polyamide / polyester composite fiber was produced so that the single yarn fineness was 6.0 denier. The conjugate fiber obtained by spinning / winding was drawn using a separate drawing device to produce a crimp-expressing elastic conjugate fiber having a single-denier fineness of 2.1 denier with a spring-shaped crimp. . The stretching ratio at the time of stretching was 2.90, the stretching temperature was 75 ° C., and the heat setting temperature was 145 ° C. The results are shown in Table 2. Stretch characteristics were slightly reduced in the raw yarn and woven fabric, and unstable morphological stability was exhibited.

It is a heat-shrinkage-stress analysis figure of the crimp-forming composite fiber excellent in the stretchability used in this invention and the form stability in the post-processing. (A)-(d) is sectional drawing of the crimp-forming composite fiber excellent in the elasticity and the shape stability in the case of post-processing manufactured by this invention.

Claims (11)

  Obtained using a fiber-forming polymer capable of two types of melt spinning, the maximum heat shrinkage stress temperature of the fiber is 155 ° C. or higher, and the crimp elongation after boiling water treatment under no load is 40% or higher, A stretchable composite fiber excellent in form stability, characterized in that a processed fabric having an elastic recovery rate of 70% or more and an iron shrinkage of 3% or less can be produced.   One kind of polymer is polyethylene terephthalate, the number average molecular weight is 10,000 to 20,000, the molecular weight distribution index is 1.5 to 2.5, and the other kind of polymer is polytrimethylene terephthalate. The number average molecular weight is 15,000 to 90,000, the molecular weight distribution index is 1.5 to 2.5, and the number average molecular weight difference between the two polymers is 5,000 to 70,000. The stretchable composite fiber having excellent shape stability according to claim 1.   One polymer is polyethylene terephthalate having a number average molecular weight of 10,000 to 20,000 and a molecular weight distribution index of 1.5 to 2.5, and the other polymer is polyethylene terephthalate and polybutylene. A terephthalate or polyethylene terephthalate copolymer having a number average molecular weight of 15,000 to 90,000, a molecular weight distribution index of 1.5 to 2.5, and a difference in number average molecular weight of the two polymers of 5,000 to 70, The elastic composite fiber having excellent shape stability according to claim 1, wherein the elastic composite fiber is 000.   The stretchable composite fiber having excellent shape stability according to claim 1, wherein the cross-sectional shape is a side-by-side type or an eccentric core-sheath (Sheath-Core) type.   2. The stretchable composite fiber having excellent shape stability according to claim 1, wherein the crimp has a diameter of 8 mm or less. (A) One polymer is polyethylene terephthalate having a number average molecular weight of 10,000 to 20,000 and a molecular weight distribution index of 1.5 to 2.5. Melting methylene terephthalate with two polyesters having a number average molecular weight of 15,000 to 90,000 and a molecular weight distribution index of 1.5 to 2.5;
(B) After passing the melt through the spin pack so that the residence time in the spin pack is 5 minutes or less, side-by-side type or eccentric core-sheath type at a spinning speed of 2,200 to 5,000 m / min A process of taking the composite yarn,
(С) A method for producing a stretchable composite fiber having excellent shape stability, which is produced by a method comprising a step of drawing a drawn composite yarn at a temperature of 85 to 95 ° C and heat-setting at a temperature of 160 to 220 ° C. (A) One kind of polymer is polyethylene terephthalate, the number average molecular weight is 10,000 to 20,000, the molecular weight distribution index is 1.5 to 2.5, and the other one kind of polymer is polyethylene terephthalate. A step of melting two polyesters having a number average molecular weight of 15,000 to 90,000 and a molecular weight distribution index of 1.5 to 2.5 in a polybutylene terephthalate or polyethylene terephthalate copolymer;
(B) After passing the melt through the spin pack so that the residence time in the spin pack is 5 minutes or less, side-by-side type or eccentric core-sheath type at a spinning speed of 2,200 to 5,000 m / min A process of taking the composite yarn,
(С) A method for producing a stretchable composite fiber having excellent shape stability, which is produced by a method comprising a step of drawing a drawn composite yarn at a temperature of 85 to 95 ° C and heat-setting at a temperature of 160 to 220 ° C.   The method for producing a stretchable composite fiber having excellent shape stability according to claim 6 or 7, wherein the method is produced by a partial orientation-drawing / false twisting method or a spinning direct drawing method.   A processed yarn produced from the stretchable conjugate fiber according to claim 1 and having a twist number (TM: twist / meter) of 150 to 2,000.   A blended yarn in which the stretchable composite fiber according to claim 1 is mixed with a high-shrinkage property yarn having an elongation of 50% or more and a boiling water shrinkage of 15% or more.   A fabric comprising the stretchable conjugate fiber according to claim 1.

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