JP2005213673A - Polyamide composite false-twist yarn and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a polyamide composite false-twist yarn that produces high heat retaining property and softness of surface feeling in making a woven or knitted fabric by developing difference in filament length of at least two or more kinds of multifilaments besides excellent properties such as mechanical strength, durability, hygroscopicity, etc., which a polyamide filament has. <P>SOLUTION: The polyamide composite false-twist yarn is a core-sheath type composite false-twist yarn composed of a polyamide multifilament A at least as a core part and a polymer alloy multifilament B, in which a polyester is dispersed in a polyamide, as a sheath part. The difference in filament length between the multifilament A and the multifilament B is and ≥4% and <35%. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a core-sheath type composite false twisted yarn having a yarn length difference and a method for producing the same. Composite false twisted yarn is composed of polyamide multifilament and polymer alloy multifilament in which polyester is dispersed in polyamide, and it is soft and excellent in swelling, and can be produced stably using existing equipment. It relates to a manufacturing method.

  Polyester unstretched yarn and highly oriented unstretched yarn (so-called POY) both have a constant stress extension region, and composite stretching is performed by combining unstretched yarn and highly oriented unstretched yarn, or highly oriented unstretched yarn and stretched yarn. When false twisting, by setting the draw ratio according to the low-elongation-side supply yarn, the high-elongation-side supply yarn is wound around the low-elongation-side supply yarn during twisting and untwisted. A difference in the length of the high-elongation-side supply yarn appears with respect to the low-elongation-side supply yarn. Therefore, when used for a woven or knitted fabric, a bulge and a soft texture can be imparted.

  On the other hand, in the case of polyamide, the unstretched yarn (taken speed: 500 to 1000 m / min) has a constant stress extension region, but the POY (taken speed: 2500 to 5500 m / min) has no constant stress extension region. This is because in the case of polyamide, if the take-up speed is set to about 2000 m / min, swelling occurs during winding, and winding becomes impossible. Therefore, in order to obtain a core-sheath type composite false twisted yarn having a yarn length difference such as polyester, there is no choice but to combine POY and undrawn yarn.

  However, unstretched yarns are sensitive to temperature and humidity, tend to swell and shrink, and are very difficult to transport between factories. Therefore, production factories are limited, and false twisting is only performed in factories that perform unstretched spinning of polyamides. Was impossible. Also, the quality of the end face cycle due to the difference in moisture absorption between the drum end face and the inside of the drum is likely to occur, and the undrawn yarn is thermally unstable, resulting in frequent fusion to the heater and associated yarn breakage. As described in Patent Document 1, a core-sheath structure yarn by a composite false twist commonly used for polyester as described in Patent Document 1 (the sheath yarn has a yarn length difference with respect to the core yarn) It could not be realized easily. In addition, the composite false twisted yarn composed of a combination of POY and undrawn yarn has a difference that the undrawn yarn has an elongation of about 300% and the POY is about 65%. There is a problem that the strength is borne, the yarn strength is lowered, and troubles such as yarn breakage are likely to occur during weaving and weaving. Further, the finished knitted or knitted fabric is not preferable because it tends to have a dull texture.

  Another method for obtaining a composite false twisted yarn having a core-sheath structure using a polyamide multifilament is that when the core yarn and the sheath yarn are entangled before false twisting, the sheath is against the multifilament that becomes the core yarn. Overfeeding the multifilament to be used as a yarn, preliminarily twisting the yarn after adding a yarn length difference, and adding a yarn length difference by using drawn yarn as the core yarn and POY as the sheath yarn ing. However, the difference in yarn length that can be applied at the time of entanglement before false twisting is about 1 to 2%, and even if a drawn yarn is used as the core yarn and POY is used as the sheath yarn, a yarn length of less than 3% can be applied at most. It was impossible, and it was difficult to give a feeling of swelling.

For this reason, as for polyamide, air-processed yarns are widely produced in which a plurality of drawn yarns are subjected to air processing with different supply speeds to express loop-like fluff. The air-processed yarn has a cotton-like fluffy feel when it is made into a woven fabric, but it has a casual texture, but it does not have the crimp of the false twisted yarn, so the surface of the false twisted yarn is inferior in softness. In addition, since air processing uses a large amount of compressed air, there is a problem that the processing cost is higher than that of false twisting.
JP 2003-278039 A

  The present invention is a polyamide multifilament excellent in abrasion resistance, strength, hygroscopicity, color development, softness, etc. compared with other synthetic fibers, and is bulky even when tension is applied in the fiber axis direction like a woven fabric. Provides a core-sheath type composite false twisted yarn that has excellent heat retention and has a soft surface touch by false twist crimping, and a manufacturing method that can be easily produced using existing false twisting equipment There is to do.

In order to solve the above problems, the present invention has the following configuration. That is,
(1) A core-sheath type composite false twisted yarn comprising at least a polyamide multifilament A as a core and a polymer alloy multifilament B in which polyester is dispersed in polyamide as a sheath, and the multifilament A and the multifilament A polyamide composite false twisted yarn, wherein the difference in yarn length of B is 4% or more and less than 35%.
(2) A polyamide multifilament Fa having an elongation of 30 to 67% and a polyester of 5% to less than 60% are dispersed in the polyamide, and a polymer alloy multifilament Fb having an elongation of 70 to 200% is simultaneously false twisted. A process for producing a polyamide composite false twisted yarn characterized by

  The present invention relates to a core-sheath type composite false twisted yarn having a yarn length difference and a method for producing the same. The composite false twisted yarn is composed of polyamide multifilament and polymer alloy multifilament in which polyester is dispersed in polyamide, and is soft and excellent in swelling. The present invention also relates to a manufacturing method that can be stably produced using existing equipment.

  The composite false twisted yarn of the present invention is a core / sheath type composite false twisted yarn composed of at least a polyamide multifilament A as a core and a polymer alloy multifilament B in which polyester is dispersed in polyamide as a sheath. That is, a composite false twisted yarn composed of polyamide as a main polymer component.

  The reason for choosing polyamide as the main polymer is excellent in strength, durability, fastness, moisture absorption, softness of touch, color development, etc., especially in terms of wear durability, hygroscopicity, softness of touch. One of the excellent synthetic fibers. It is preferably used for socks and innerwear that touch the skin, and is widely used for outer garments that require good adhesion such as durability, wear resistance, moisture-permeable waterproofing, etc., as in sports applications.

  Here, the main polymer means that when a woven or knitted fabric is knitted and woven using the composite false twisted yarn of the present invention and then dyed, it can be commercialized by dyeing with an acid dye or reactive dye. Polyamide multifilaments can be dyed with disperse dyes, but polyester multifilaments cannot be dyed with acid dyes. Polyester is dispersed in the polymer alloy multifilament B used in the present invention. However, since the dispersion diameter is small and the ratio is relatively low as described later, it is not necessary to dye with a disperse dye. Like filaments, it can be dyed with acid dyes or reactive dyes.

  Polyamide is a high molecular weight product in which a so-called hydrocarbon group is connected to the main chain via an amide bond, and the type thereof is not particularly limited, but preferably it is excellent in dyeability, washing fastness, and mechanical properties. Mainly polycapramide or polyhexamethylene adipamide. The term “mainly” as used herein means 80 mol% or more, more preferably 90 mol% or more, as a capramide unit or a hexamethylene adipamide unit. Other components are not particularly limited. For example, polydodecanoamide, polyhexamethylene adipamide, polyhexamethylene azelamide, polyhexamethylene sebacamide, polyhexamethylene dodecanoamide, polymetaxylylene azide Examples thereof include units such as aminocarboxylic acid, dicarboxylic acid, and diamine, which are monomers constituting pamide, polyhexamethylene terephthalamide, polyhexamethylene isophthalamide, and the like.

  The polyester referred to in the present invention is a high molecular weight product in which a so-called polybasic acid and a polyhydric alcohol are linked via an ester bond, and the type thereof is not particularly limited, but is preferably polyethylene terephthalate, polybutylene terephthalate, It is a polyester made of polytrimethylene terephthalate, polylactic acid or the like. Here, the monomer unit constituting the polyester group is preferably 80 mol% or more, more preferably 90 mol% or more.

  Polyester is copolymerized by adding at least one third component selected from phthalic acid, isophthalic acid, and sulfoisophthalic acid in order to improve the affinity with polyamide and finely disperse the polyester in the polyamide. It is preferable that it is polyester obtained. The copolymerization rate of phthalic acid, isophthalic acid, and sulfoisophthalic acid is preferably 4 mol% or more in order to improve the affinity with polyamide.

  The degree of polymerization of the polyester referred to in the present invention is preferably 0.45 or more as an intrinsic viscosity.

  The polyamide or polyester referred to in the present invention may contain various additives as long as the effects of the present invention are not impaired. Examples of this additive include stabilizers such as manganese compounds, colorants such as titanium oxide, plasticizers, lubricants, flame retardants, conductivity imparting agents, and fibrous reinforcing agents.

  As described above, the polymer alloy multifilament B in which the polyester is dispersed in the polyamide constitutes the sheath of the polyamide composite false twisted yarn. The reason why the polyester is dispersed is that, even when the elongation of the polymer alloy multifilament Fb is increased, a stable POY can be obtained without swelling. Therefore, when the composite false twist is combined with the polyamide multifilament A, Yarn length difference develops. The distribution state of the polyester in the polyamide is not particularly limited. For example, the polyester is continuously distributed without changing the cross-sectional shape in the fiber axis direction, or is present in the form of islands in the polyamide sea. It can also be made. In particular, it is preferable that the polyester is dispersed in a sea-island structure in which polyamide is the sea and polyester is the island. Furthermore, it is more preferable that the polyester which is an island forms a streak structure. As used herein, the term “stripe structure” refers to a structure in which the ratio of length to diameter in the fiber axis direction of polyester, which is an island, is 4 or more. This stabilizes the spinning refinement behavior, thus enabling stable melt spinning.

  Furthermore, it is preferable that the average diameter of polyester which is an island is 1 to 100 nm. More preferably, it is 1-50 nm. That is, the average diameter of polyester, which is an island, is small and finely dispersed, thereby improving the yarn-making stability. In addition, when polyamide is dyed with an acid dye or reactive dye, the polyester is not dyed, but since the fine particles are dispersed, it is possible to suppress a decrease in color developability. Here, the island polyester may have a slightly distorted elliptical shape, and is not necessarily a perfect circle. Therefore, the diameter is calculated in terms of a circle from the area of the island polyester. If the average diameter of the polyester polyester is less than 1 nm, the polymer interface between the sea polyamide and the polyester polyester becomes large and the interaction at the interface becomes excessive, so the spinning thinning behavior is not stable, and the spun yarn Many cuts occur, resulting in poor operability. In addition, when the average diameter of polyester as an island exceeds 100 nm, the polyester as an island itself becomes a foreign substance, and many yarn breaks occur during spinning, resulting in poor operability, and fluff or single yarn breakage.

  Furthermore, the area ratio of the polyester which is an island having a circle-converted diameter of 200 nm or more is preferably 3% or less, more preferably 1% or less, with respect to the entire island in the fiber cross section. That is, in order to improve operability, it is effective not only to reduce the average diameter of particles but also to suppress coarse particles that are directly connected to yarn breakage. If the area ratio of polyester, which is a coarse island with a diameter of 200 nm or more, exceeds 3% of the whole island, the polyester itself becomes a foreign substance, and many yarn breaks occur during spinning, resulting in poor operability. Thread breakage occurs.

  Furthermore, the composite false twisted yarn of the present invention has a yarn length difference of 4% or more and less than 35% between the polyamide multifilament A and the polymer alloy multifilament B. That is, the yarn length of the polymer alloy multifilament B as the sheath yarn is 4% or more and less than 35% with respect to the polyamide multifilament A as the core yarn. Here, when the yarn length difference is less than 4%, the bulkiness is not sufficiently felt and the purpose of the core-sheath type composite false twisted yarn cannot be achieved. Is not sufficiently covered, and so-called “irregularity” is likely to occur due to a difference in dyeing between the sheath yarn and the core yarn, resulting in poor quality of the woven or knitted fabric. On the other hand, when the yarn length difference is 35% or more, the sheath yarn is misaligned with respect to the core yarn during false twisting or high-order processing, and trouble occurs during knitting, weft driving, and knitting. It is not preferable.

  The crimped form of the composite false twisted yarn of the present invention varies depending on the characteristics of the raw yarn used, the combination of fineness, etc., but the polyamide multifilament A of the core is generally a single false twisted yarn or a little inferior crimped However, the polymer alloy multifilament B in the sheath part has a weaker crimp than the polyamide multifilament A and tends to converge. This is because the polyamide multifilament A is arranged at the center and the polymer alloy multifilament B is arranged so as to surround it when in the twisted state of false twisting.

  Although the cross section of the composite false twisted yarn of the present invention is deformed by false twisting, not only a round cross section but also a deformed cross section is preferably used as a cross section before false twisting. Any shape such as a polygonal shape, a multi-leaf shape, a flat shape, and a hollow shape can be used without any problem. A combination of two or more cross-sectional shapes is also preferably used.

  Similarly, the fineness is not limited, and the single yarn fineness after false twist is preferably about 0.5 to 10 dtex or a combination thereof, and the total fineness is preferably about 20 to 500 dtex.

  Since the composite false twisted yarn of the present invention has a yarn length difference between the core yarn and the sheath yarn, if not converged, the sheath yarn is displaced and the sheath yarn is accumulated, the product quality is lowered, or the weaving This is not preferable because it causes thread breakage and stopping when making a knitted fabric. Examples of the converging method include, but are not limited to, confounding, actual twisting, and oiling. Of these, entanglement and oiling that can be performed simultaneously with false twisting are preferred, and both are also preferred. Among them, the entanglement is effective, and it is preferable that the entanglement is applied to such an extent that the product quality is not lowered when the knitted or knitted fabric is formed.

  Moreover, the composite false twisted yarn of the present invention can also be obtained as a woven or knitted fabric as a fiber product. Furthermore, it is possible to obtain new added values such as weight reduction and gloss control by reducing or dissolving the polyester component in the woven or knitted fabric or clothing by alkali. Of course, the weight can be reduced by alkali in the state of the composite false twisted yarn. Here, the alkali includes sodium hydroxide compound, potassium hydroxide compound, sodium carbonate, potassium carbonate and the like, but strong alkali such as sodium hydroxide compound and potassium hydroxide compound is 1 to 20% by weight, It is preferable to process at 60-120 degreeC.

  The fiber product using the composite false twisted yarn of the present invention is not particularly limited, but it is used for clothing such as innerwear, socks such as tights, textiles such as textiles for sports and casual wear, mainly for fall and winter. It is also preferably used for materials, industrial materials, and vehicle interiors.

  The yarn can be converged by imparting entanglement during false twisting and used as it is in a woven or knitted fabric. Further, twisting can be preferably performed. When twisting is performed, flaking due to a difference in yarn length is suppressed (bulkness control), or when a dyeing difference between the core yarn and the sheath yarn is expressed, the core yarn is used as the sheath yarn. Can be covered. The strength of the actual twist can be appropriately selected according to the purpose from sweet twist to strong twist, and the twist direction is not particularly limited. For example, if it is additionally twisted in the same direction as the false twist, the surface of the woven or knitted fabric is obtained. When the surface is clean and reversed, the bulkiness can be emphasized.

  Next, a method for producing a polyamide composite false twisted yarn will be described in detail. The polyamide composite false twisted yarn of the present invention is produced by the following method. That is, a manufacturing method in which a polyamide multifilament Fa having an elongation of 30 to 67% and a polyester of 5% or more and less than 60% are dispersed in the polyamide and simultaneously nano-twisting the nanoalloy multifilament Fb having an elongation of 70 to 200%. It is. By this method, a core-sheath type composite false twisted yarn composed of at least a polyamide multifilament A as a core and a polymer alloy multifilament B in which polyester is dispersed in polyamide as a sheath, The yarn length difference between the filament A and the polymer alloy multifilament B can be 4% or more and less than 35%.

  Here, the polyamide multifilament Fa having an elongation of 30 to 67% is a so-called polyamide multifilament drawn yarn or POY, and its production method is not limited. The direct spinning drawing method, the high speed spinning method in which the spinning speed is set to a high speed of 2500 m / min or more and the drawing step is substantially omitted, or the high speed direct spinning drawing method combining them is preferably used. Specifically, for example, as a method for producing a drawn yarn, after melting a polyamide having a ηr of about 2 to 3.5 at about 255 to 320 ° C., it is discharged from a nozzle discharge hole, and an oil agent is applied. A drawn yarn is obtained by taking up the 1GD roller at about 1200 m / min, winding the undrawn yarn at about the same speed, and then drawing about 3 times using a drawing machine. Also, as another method, it is the same as the unstretched yarn until the polyamide is discharged from the die, but after applying the oil agent and confounding, it is taken up by 1GD and stretched between 2GD and then at 2GD. After heating, the drawn yarn is wound up with some relaxation, but the winding speed is set to about 2500 to 6500 m / min, and the draw ratio between 1GD and 2GD is approximately 30 to 50%. It is obtained by doing so.

  The POY manufacturing method is the same as that for undrawn yarn until the polyamide is discharged from the die, but after applying the oil agent and applying the entanglement, it is set to about 2500 to 5500 m / min and taken up to 1 GD. It can be obtained by setting the speed almost the same between 2GD and winding it up with some relaxation without heating at 2GD. The elongation of POY is preferably set to about 30 to 67%. An elongation exceeding 67% is not preferable because the wound drum tends to swell and foam collapse, loop loss, and tightening tend to occur.

  On the other hand, as the nanoalloy multifilament Fb, 5% or more and less than 60% polyester is dispersed in polyamide and has an elongation of 70 to 200%.

  The method of taking up the high elongation polymer alloy fiber of the present invention is a direct spinning drawing method in which the yarn is continuously drawn without being wound once after spinning, the spinning speed is set to a high speed of 2500 m / min or more, and the drawing step is substantially omitted. A high-speed spinning method or a high-speed direct spinning drawing method combining them is preferably used. Specifically, for example, when a high-speed spinning method is used, the above-mentioned polyester is dispersed in a polyamide having ηr of about 2 to 3.5, and is melted at about 255 to 320 ° C. After being discharged from the oil and entangled with the oil agent, it is taken up by a 1GD roller at about 1500 to 6500 m / min, set to almost the same speed between 2GD and wound with a little relaxation without heating at 2GD. It is obtained by taking.

  As a method of dispersing the polyester in the polyamide, the length of the kneading part is 20 to 40% of the effective screw length when the polyamide and the polyester are separately measured and supplied and melt-kneaded by a twin-screw extrusion kneader. Here, the method of supplying the polymer to be kneaded is important, and fluctuations in the blend ratio over time can be suppressed by separately weighing and supplying the polyamide and the polyester. At this time, you may supply separately as a pellet, or you may supply separately in a molten state. Further, two kinds of polymers may be supplied to the root of the extrusion kneader, or one of them may be a side feed supplied from the middle of the extrusion kneader.

  The polymer alloy multifilament Fb preferably has a strength of 2 cN / dtex or more. When the strength is less than 2 cN / dtex, not only the high-order passability during yarn processing, weaving and knitting deteriorates, but also the desired durability in the final product cannot be obtained.

  The polymer alloy multifilament Fb preferably has an average diameter of 1-100 nm of polyester as an island. More preferably, it is 1-50 nm. By controlling the average diameter within the above range, when the polyester is dispersed in the polyamide, the stability of the polyester polymer interface in the dispersed state is maintained, while improving the operability during yarn production and the color development during dyeing. It is preferable because it is effective in suppressing the decrease. Here, the island polyester may have a slightly distorted elliptical shape, and is not necessarily a perfect circle. Therefore, the diameter is calculated in terms of a circle from the area of the island polyester. If the average diameter of the polyester polyester is less than 1 nm, the polymer interface between the sea polyamide and the polyester polyester becomes large and the interaction at the interface becomes excessive, so the spinning thinning behavior is not stable, and the spun yarn Many cuts occur, resulting in poor operability. Moreover, when the average diameter of the polyester polyester is more than 100 nm, the island polyester itself becomes a foreign substance, resulting in a lot of yarn breakage and poor operability, and the resulting polymer alloy multifilament Fb has fluff and single yarn breakage. Etc. occur.

  In the polymer alloy multifilament Fb, the area ratio of the polyester which is an island having a circle-converted diameter of 200 nm or more is preferably 3% or less, more preferably 1% or less with respect to the entire island in the fiber cross section. is there. By making the ratio of coarse particles in the above range, it is possible to improve the operability during spinning and false twisting, which is preferable. If the area ratio of the polyester, which is a coarse island with a diameter of 200 nm or more, exceeds 3% of the entire island, the polyester itself becomes a foreign substance, resulting in many thread breaks and poor operability. Fluff, single yarn breakage, etc. occur in the filament Fb.

  The weight ratio of polyamide to polyester of the polymer alloy multifilament Fb is preferably 40:60 to 95: 5, more preferably 70:30 to 90:10. When the weight ratio of the polyamide is less than 40%, the polyamide component is reduced, so that the characteristics of the polyamide such as softness and wear resistance are not exhibited, and the polyester is dispersed in the sea-island structure where the polyamide is the sea and the polyester is the island. However, the polyester itself becomes a foreign substance, and many spun yarn breaks occur, resulting in poor operability, and fluff or single yarn breakage occurs in the resulting polymer alloy multifilament Fb. On the other hand, when the weight ratio of polyamide exceeds 95%, the fiber swells during winding of the yarn, and the phenomenon that the yarn layer in the winding package shifts and bursts occurs, making it difficult to stably wind the yarn.

  The polymer alloy multifilament Fb used in the method for producing the polyamide composite false twisted yarn of the present invention has an elongation of 70 to 200%. If the elongation is less than 70%, it is not preferable because the yarn length difference cannot be sufficiently exhibited when the composite false twist is performed with the polyamide multifilament Fa. Further, if the elongation exceeds 200%, the fiber swells during the winding of the yarn, and the phenomenon that the yarn layer in the winding package is displaced and ruptures occurs, making it difficult to stably wind the yarn. The fastness to washing in the final product is reduced.

  The composite false twist can be performed using an existing false twister, and is not particularly limited. The twisting method is not limited to a spindle method, a triaxial twister method, a belt nip method, or the like. When it is desired to increase the crimp, it is preferable to use a spindle. When it is desired to increase the processing speed and reduce the production cost, it is preferable to use a triaxial twister or belt nip which is a friction false twist method. The heating method is not limited, and a hot plate or a high-temperature short heater may be used, and the set temperature can be freely set according to the target texture. It is recommended that the temperature be about ~ 180 ° C. Even if a cooling plate is used as the cooling method, air cooling, water cooling, and the like can be mentioned, but the cooling plate is preferably used in consideration of efficiency and yarn damage.

  A method for supplying the polyamide multifilament Fa and the nanoalloy multifilament Fb is not particularly limited as long as Fa and Fb are aligned and false twisted at the same time. For example, Fa and Fb may be supplied in an aligned manner, entangled with two yarns in advance, or falsely twisted by adding another filament. Furthermore, false twisting may be performed after imparting entanglement by increasing the supply rate of Fb with respect to Fa in advance in order to impart a yarn length difference.

  There is no particular limitation on the fineness of each of the polyamide multifilament Fa and nanoalloy multifilament Fb to be supplied. However, when used for apparel, the fineness is generally about 5 to 220 decitex, and the fineness is used for industrial applications. There is. Although there is no limitation in particular also as a single yarn fineness, 0.4-8 decitex is used preferably especially. Even as a combination, the Fb that constitutes the sheath part has a thicker fineness as the total fineness than the Fa that constitutes the core part, and a fineness as the single yarn fineness. In combination, the core portion is covered, and even when a dyeing difference occurs between the core portion and the sheath portion, the color difference is not noticeable, which is preferable. Also, by making the core part thicker, it can give a sense of tension when it is made into a woven or knitted fabric, and expresses an excellent eyelash feeling coupled with a soft feeling due to the difference in yarn length of the sheath part and fineness. Can do.

Hereinafter, the present invention will be described in more detail with reference to examples. The physical properties are measured as follows.
A. Cross-sectional observation by TEM Ultra-thin sections were cut out in the cross-sectional direction of polymer alloy multifilaments B and Fb, and the cross-section was observed with a transmission electron microscope (TEM) (H-7100FA type manufactured by Hitachi, Ltd.). Moreover, the metal dyeing | staining was given as needed.
B. Diameter of polyester as island The diameter of the island of polyester dispersed in the polyamide was determined as follows. That is, the diameter of the island in terms of a circle was obtained from a cross-sectional photograph taken by TEM using image processing software (WINROOF). The average diameter was determined by their simple number average value. At this time, the number of island domains used for averaging was measured for 300 or more island domains randomly extracted in the same cross section. However, since the sample for TEM observation is an ultrathin section, the sample is easily broken or perforated. For this reason, the analysis of the island diameter was carried out carefully with reference to the situation of the sample.
C. Strength and elongation JIS L 1013 (1992) 7.5 Tensile strength and elongation The measurement was performed according to the standard time test. A constant-speed tension tester was used, and Tensilon manufactured by Orientec was used for the measurement. As measurement conditions, measurement was performed under the conditions of a gripping interval of 50 cm and a tensile speed of 50 cm / min to obtain the maximum tensile strength, and a value obtained by dividing the tensile maximum strength was defined as strength. As the elongation, the elongation at the maximum tensile strength was determined. The number of measurements was 10 times.

  However, when measuring the undrawn yarn, the polymer alloy multifilament Fb, and the sheath yarn B of Comparative Example 2, only the sample length was changed to 5 cm.

When determining the core and sheath values of the composite false twisted yarn, carefully separate the composite false twisted yarn so as not to damage the yarn while releasing the composite false twisted yarn without twisting during the composite false twisting process. Each yarn was then measured.
D. The composite false twisted yarn that has not been given the yarn length difference entanglement is released from the cheese, and a 50 cm length is marked with vermilion with a load of gram number of fineness (decitex) × 0.09, Separated into multifilament A and sheath multifilament B, lengths La and Lb were measured in a state in which a load of 0.09 grams was applied to each fineness. The yarn length difference was determined by the following formula. Yarn length difference (%) = (Lb−La) / La × 100
In addition, the measurement frequency is performed 5 times and the average is taken.
E. Expansion / retraction rate: RS (Recovery percentage of Shrinkage:%)
Make a small casserole according to JIS L1090-1992, 5.8 Stretching Restoration Rate for a sample left for 1 week in a room where temperature and humidity are controlled at 25 ° C. and 60% with the false twisted yarn in a package. After immersing in hot water at 98 ° C. for 30 minutes, the sample is taken out, and the sample naturally dried for 24 hours on the filter paper is measured according to the 5.8 stretch recovery rate.
F. Sensory evaluation of the tubular knitted fabric was carried out with respect to the ground thickness of the polyamide knitted fabric false twisted yarn, and judged by ○, Δ, and ×. For measurement at the knitted fabric, a composite false twisted yarn was knitted by a 27G cylindrical knitting machine, and a cylindrical knitted fabric with a course number of raw knitting of 45 / 2.35 cm was used. The bath ratio was 1:20, the temperature was raised from room temperature at 10 ° C./min, and dyeing was performed at 90 ° C. for 15 minutes. In addition, as evaluation criteria, ○: excellent in the sense of ground thickness, and the texture of the surface is soft. Δ: Compared with normal false twisted yarn, the texture of the ground is soft and the texture of the surface is also soft. Small, x: The texture of a normal false twisted yarn is not different.

[Examples 1 to 3]
Copolyethylene obtained by copolymerizing polymolar polyamide (containing 0.02% by weight of titanium oxide) with 98% sulfuric acid relative viscosity as polyamide and 5 mol% of 5-sodium sulfoisophthalic acid with intrinsic viscosity of 0.55 as polyester Terephthalate was charged into a twin screw extrusion kneader at a weight ratio shown in Table 1, and melt kneaded at 260 ° C. to obtain polymer alloy pellets. The average diameter of polyester which is an island of these pellets, and the area ratio with respect to the whole polyester island which is a coarse island having a diameter of 100 nm or more were measured. The results are shown in Table 1 together with other examples and comparative examples.
These polymer alloy pellets are melted at a spinning temperature of 275 ° C., discharged from a die having a 0.2 mm round discharge hole, and then cooled by a normal method so that the oil adhesion amount becomes 0.6% by weight. After being entangled and taken up at 4080 m / min after being entangled, it was wound up at 4000 m / min without substantial stretching to obtain a polymer alloy multifilament Fb of 53 dtex 34 filaments. In addition, there was no yarn breakage at the time of winding, and the yarn could be produced stably. Regarding the obtained Fb, the average diameter of polyester as an island and the area ratio, fineness, strength and elongation of the polyester as a coarse island having a diameter of 200 nm or more were measured. The results are shown in Table 1 together with other examples and comparative examples.

  On the other hand, polyhexamethylene adipamide (containing 0.3% by weight of titanium oxide) with a 98% sulfuric acid relative viscosity of 2.6 as a polyamide is melted at a spinning temperature of 290 ° C., and a die having a 0.3 mm round discharge hole. After being discharged from the water, it is cooled by a normal method, oiled so that the amount of oil adhered becomes 0.6% by weight, entangled and then taken up, stretched to an elongation of 44%, and then 4000 m Per minute to obtain a polyamide multifilament Fa of 33 dtex 6 filaments. The fineness, strength, and elongation were measured and shown in Table 1 together with other examples and comparative examples.

Further, using the false twisting machine shown in FIG. 1 (Ishikawa Seisakusho: IVF850), Fa and Fb were fed together to obtain a composite false twisted yarn of 78 decitex 40 filaments. The conditions for false twisting are set such that the 2FR speed is 300 m / min, the 1FR speed is set to 273 m / min, and the D / Y ratio is set so that the untwisting tension / twisting tension is 1.1. The temperature was 155 ° C. In addition, although it entangled and wound up before winding, in order to measure the physical property of each thread | yarn, it sampled a small amount without providing entanglement (other levels are also the same). The obtained composite false twisted yarn and the polyamide multifilament A forming the core part and the polymer alloy multifilament B forming the sheath part were separated, and the physical properties of the yarn were measured. The examples and comparative examples are shown.
When the composite false twisted yarn is observed, the polyamide multifilament A forming the core portion is provided with a relatively strong crimp and is positioned at the center of the composite false twisted yarn, while forming a sheath portion. The polymer alloy multifilament B had a yarn length difference shown in Table 2 with respect to A, and the crimp was weaker than that of A.
When a tubular knitted fabric is prepared and the texture is evaluated, the difference in yarn length increases and the sense of thickness increases, and the polymer alloy multifilament B that has been crimped floats on the surface, resulting in a soft texture. It was.

[Example 4]
Using the same polymer as in Example 1, polymer alloy pellets were produced in the same manner except that the weight ratio shown in Table 1 was used. The average diameter of polyester which is an island of these pellets, and the area ratio with respect to the whole polyester island which is a coarse island having a diameter of 100 nm or more were measured.
These polymer alloy pellets are melted at a spinning temperature of 275 ° C., discharged from a die having a 0.2 mm round discharge hole, and then cooled by a normal method so that the oil adhesion amount becomes 0.6% by weight. After being entangled and taken up at 3060 m / min after being entangled, it was wound up at 3000 m / min without substantial stretching to obtain a polymer alloy multifilament Fb of 53 dtex 34 filaments. Table 1 shows the measurement results. In addition, there was no yarn breakage at the time of winding, and the yarn could be produced stably.
On the other hand, the same polyamide multifilament Fa as that in Example 1 was used.
Furthermore, the false twisting machine and false twisting conditions were the same as in Example 1.
When the composite false twisted yarn is observed, the polyamide multifilament A forming the core portion is provided with a relatively strong crimp and is positioned at the center of the composite false twisted yarn, while forming a sheath portion. The polymer alloy multifilament B had a yarn length difference shown in Table 2 with respect to A, and the crimp was weaker than that of A.
When creating a tubular knitted fabric and evaluating the texture, the difference in yarn length is very high, and the sense of thickness is high, and the polymer alloy multifilament B with crimps floats on the surface and is soft. It was a natural texture.

[Example 5]
The same polymer alloy multifilament Fb as in Example 3 was used.
On the other hand, polyhexamethylene adipamide (containing 0.3% by weight of titanium oxide) with a 98% sulfuric acid relative viscosity of 2.6 as polyamide is melted at a spinning temperature of 290 ° C., and a die having a round discharge hole of 0.25 mm. After being discharged from the water, it is cooled by a normal method, and oil is applied so that the oil adhesion amount is 0.6% by weight. After confounding, it is taken up at 4100 m / min, and at 4000 m / min without substantial stretching. Winding to obtain a polyamide multifilament Fa of 37 dtex 6 filaments.
Further, using the same false twisting machine as in Example 1, only 1 FR speed was changed to 242 m / min to obtain a composite false twisted yarn of 78 dtex 40 filaments.
When the composite false twisted yarn is observed, the polyamide multifilament A forming the core portion is provided with a relatively strong crimp and is positioned at the center of the composite false twisted yarn, while forming a sheath portion. The polymer alloy multifilament B had a yarn length difference shown in Table 2 with respect to A, and the crimp was weaker than that of A.
When creating a tubular knitted fabric and evaluating the texture, the difference in yarn length is high, so the texture is high, and the crimped polymer alloy multifilament B floats on the surface, so the soft texture It was.

Comparative Example 1
As the Fb that constitutes the yarn of the sheath, the polymer discharge amount is changed from the same polymer as Fa in Example 5 and a base having a 0.2 mm round discharge hole under the same spinning conditions, and 53 decitex 34 filaments. A polyamide multifilament was obtained.
On the other hand, the same yarn as in Example 1 was used as Fa that would constitute the core yarn.
The composite false twisting was performed under the same conditions as in Example 1, and the results are shown in Table 1.
Even when the composite false twisted yarn is observed, it can be seen that the single yarn fineness is different, so that it is composed of two types of multifilaments A and B. Since the yarn length difference was as small as 2.1%, a large difference from a normal false twisted yarn was not observed.
When a tubular knitted fabric was prepared and the texture was evaluated, there was almost no difference in yarn length, so that a sense of ground thickness was not felt, and a texture of a normal false twisted yarn was obtained.

Comparative Example 2
The same polymer as Fa in Example 1 is used as Fb constituting the yarn of the sheath part, and after discharging from a base having a 0.2 mm round discharge hole, cooling is performed by a normal method, and the oil adhesion amount Was taken up at 600 m / min and wound up at 600 m / min without substantial stretching to obtain a polyamide multifilament with 53 dtex 10 filaments.
On the other hand, the same yarn as in Example 1 was used as Fa that would constitute the core yarn.
The composite false twisting was performed under the same conditions as in Example 1, and the results are shown in Table 1.
When the composite false twisted yarn is observed, the polyamide multifilament A forming the core portion is provided with a relatively strong crimp and is positioned at the center of the composite false twisted yarn, while forming a sheath portion. Polyamide multifilament B has a yarn length difference close to 40% with respect to A, and the crimp is very weak compared to A, so it is in a state close to separation although entangled, The yarn of B was unevenly distributed with respect to A.
When a tubular knitted fabric is created and the texture is evaluated, the yarn length difference is too high, so it is a soft texture rather than a feeling of ground thickness, and the multifilament B in the sheath is unevenly distributed with respect to A As a result, the surface of the knitted fabric was rough.

  When the color developability of the tubular knitting of Examples 1 to 4 and Comparative Examples 1 and 2 was compared, the sheath color had a yarn length difference and did not take a converged form. In Comparative Example 2, although the color developability seemed to be bad, it was caused by the thread form, and the level of color developability was almost the same as that of polyamide.

1 is a schematic diagram of a false twisting machine used in Example 1. FIG.

Explanation of symbols

1: 1 FR
2: Heater 3: Cooling plate 4: Twister 5: 2FR
6: Entanglement nozzle 7: 3FR
8: Winder 9: Composite false twisted yarn Fa: Polyamide multifilament Fb: Nanoalloy multifilament

Claims (2)

A core-sheath type composite false twisted yarn comprising at least a polyamide multifilament A as a core and a polymer alloy multifilament B in which polyester is dispersed in polyamide as a sheath, and the polyamide multifilament A and the polymer alloy multifilament A polyamide composite false twisted yarn, wherein the difference in yarn length of B is 4% or more and less than 35%. A polyamide multifilament Fa having an elongation of 30 to 67% and a polyester of 5% by weight to less than 60% by weight are dispersed in the polyamide, and simultaneously false twisting a polymer alloy multifilament Fb having an elongation of 70 to 200%. A method for producing a polyamide composite false twisted yarn.

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