TW201817931A - High-temperature-shrinkable polyamide composite fiber, textured yarn, and textile partially using such polyamide composite fiber and textured yarn - Google Patents

Abstract

Provided is a textile which, by using a high-temperature-shrinkable polyamide composite fiber, is able to shrink by a stress that overwhelms a textile restraining force even when the textile is subjected to moist heat/dry heat while a high tension is being applied thereto in the warp direction, and which is able to exhibit sufficient crimp properties so as to have good stretch properties and exhibit an airy texture. This high-temperature-shrinkable polyamide composite fiber is a polyamide composite fiber of a laminated type or an eccentric core-sheath type comprising two types of polyamides (A) and (B) having different compositions, the high-temperature-shrinkable polyamide composite being characterized in that: the polyamide (A) contains an amorphous polyamide; the polyamide (B) is a crystalline polyamide; and the composite fiber has a heat shrinkage stress of at least 0.15 cN/dtex.

Description

   High heat-shrinkable polyamide composite fiber and processed silk and knitted fabric using the same   

The present invention relates to a high heat-shrinkable polyamide composite fiber, a processed yarn, and a knitted fabric using the same as a part.

Polyamide fibers are softer than polyester and have a better touch since they have been known, and are widely used in clothing applications. Monofilaments composed of a single component such as nylon 6 or nylon 66, which is a polyamide fiber for clothing, have no crimpability, so they are subjected to false twist processing, etc. to provide crimpability and are used for stretchable Knitting use. However, it is difficult to obtain a knitted fabric having good stretchability by performing false twist processing on the monofilament.

There are known proposals: by using two polyamides with different properties, the same cross-section of the same monofilament can be laminated or eccentrically combined to form a polyamide composite fiber, which can give the fiber potential crimpability and obtain stretch. Method of sexual knitting.

For example, Patent Document 1 discloses a one-component nylon 12 or nylon 610 bonded type or eccentric core-sheath type polyamide composite fiber.

In addition, Patent Document 2 discloses that the two-component polyamidamine has a difference in relative viscosity of 0.4 or more and 1.6 or less and a type of polyamidamine composite fiber.

    [Prior technical literature]         [Patent Literature]    

Patent Document 1: Japanese Patent Laid-Open No. 2001-159030

Patent Document 2: Japanese Patent Laid-Open No. 2002-363827

However, the polyamide composite fibers disclosed in Patent Documents 1 and 2 are excellent in the crimpability of raw yarns or processed yarns. Although coarse-density knitted fabrics can obtain good stretchability, ordinary knitted fabrics cannot be sufficiently drawn Stretchability. That is, since the polyamide composite fiber-based fiber is soft, wrinkles are easily generated in a moist heat step such as dyeing during the production of a knitted fabric, and are not easily wrinkled in a dry heat step such as setting a finished product. In order to finish the knitted fabric into a beautiful cloth without wrinkles, it is generally manufactured under high tension in the warp direction. In particular, in the case of fabrics, because there are many interlaced points, if the fabric is manufactured under high tension in the warp direction, the polyamide composite fibers disclosed in Patent Documents 1 and 2 will have slightly better fabric restraint in the warp direction. Because of this, the shrinkability cannot be sufficiently developed, and sufficient stretchability cannot be obtained. In addition, since the warp yarn direction does not sufficiently show crimping, it is a woven fabric having a poor fluffy feeling. The higher the density of the knit fabrics in particular, the more pronounced this tendency is.

The reason is that the present invention is intended to solve the above-mentioned problems, and an object thereof is to provide a highly heat-shrinkable polyamide composite fiber having a good stretchability and a fluffy knitted fabric.

In order to achieve the above object, the highly heat-shrinkable polyamide composite fiber of the present invention mainly has the following configuration.

(1) A high heat shrinkable polyamide composite fiber, which is a laminated or eccentric core-sheath composite fiber composed of two types of polyamide (A) and polyamide (B) with mutually different compositions. The amidine (A) contains amorphous polyamine, and the polyamine (B) is a crystalline polyamine, and the heat shrinkage stress of the composite fiber is 0.15 cN / dtex or more.

(2) The highly heat-shrinkable polyamidamine composite fiber according to (1), wherein the polyamidamine-based isophthalic acid / terephthalic acid / hexamethylenediamine is a polycondensate.

(3) The highly heat-shrinkable polyamide composite fiber according to (1) or (2), wherein the rigid amorphous amount of the composite fiber is 17 to 35%.

(4) The highly heat-shrinkable polyamide composite fiber according to any one of (1) to (3), wherein the elongation and expansion ratio of the composite fiber is 20 to 80%.

(5) A polyamide processing yarn composed of the high heat-shrinkable polyamide composite fiber according to any one of (1) to (4).

(6) A knitted fabric comprising at least a part of the high heat-shrinkable polyamide composite fiber according to any one of (1) to (4), or the polyamide processed yarn according to (5).

The highly heat-shrinkable polyamide composite fiber or the processing yarn composed of the high heat-shrinkable polyamide composite fiber of the present invention can shrink the stress of the braided fabric by applying moist heat and dry heat even when high tension is applied to the warp direction. The direction fully exhibits crimpability, and can provide a knitted fabric with good stretchability and fluffy feel.

The polyamide composite fiber with high heat shrinkability of the present invention is a laminated or eccentric core-sheath composite fiber, and is composed of polyamide (A) containing amorphous polyamide and crystalline polyamide. Of polyamine (B). The "laminated composite fiber" mainly refers to a composite fiber in which two or more types of polyamide are bonded along the fiber length direction. The "eccentric core-sheath composite fiber" refers to a composite fiber in which two or more kinds of polyamides form an eccentric core-sheath structure.

Polyamide (A) contained in polyamide (A) constituting the polyamide composite fiber is a polyamine that does not form crystals and does not have a melting point. For example, isophthalic acid / terephthalic acid / hexane Diamine polycondensate, isophthalic acid / terephthalic acid / hexamethylene diamine / bis (3-methyl-4-aminocyclohexyl) methane polycondensate, isophthalic acid / 2,2,4-trimethyl Polycondensate of hexamethylenediamine / 2,4,4-trimethylhexamethylene diamine, terephthalic acid / 2,2,4-trimethylhexamethylenediamine / 2,4,4-trimethylhexamethylene diamine Polycondensates, isophthalic acid / terephthalic acid / 2,2,4-trimethylhexamethylene diamine / 2,4,4-trimethylhexamethylene diamine polycondensate, isophthalic acid / bis (3-methyl -4-Aminocyclohexyl) methane / ω-dodecylamine polycondensate, terephthalic acid / bis (3-methyl-4-aminocyclohexyl) methane / ω-dodecylamine polycondensation体 等。 Body and so on. The benzene ring of the terephthalic acid component and / or isophthalic acid component constituting the polycondensate also includes those substituted with an alkyl group or a halogen atom. These amorphous polyamides may be used singly or in combination of two or more. Any of the amorphous polyamides used in the highly heat-shrinkable polyamide composite fiber of the present invention may be used. From the viewpoint of considering both manufacturing cost and fiber shrinkage characteristics, isophthalic acid / terephthalic acid / hexane Polycondensates of amines.

The polyamide (B) constituting the highly heat-shrinkable polyamide compound fiber of the present invention is a crystalline polyamide, that is, a crystalline polyamide having a melting point. The so-called hydrocarbon group is polymerized by being bonded to the main chain via a polyamide bond. For example, polydecanamide, polyhexamethylene adipamide, polyhexamethylene adipamide, polytetramethylene adipamide, 1,4-cyclohexanediamine (Methylamine) is a polycondensation polymer such as a linear aliphatic dicarboxylic acid, polyamine, or the like, or a copolymer or a mixture thereof. Among them, from the viewpoint of easily presenting a homogeneous system and showing stability, it is preferable to use homopolyamine.

The crystalline polyamidoamine is preferably composed of diamines and dibasic acids. Specific examples of the diamines include butanediamine, nonanediamine, undecanediamine, dodecanediamine, 2,2,4-trimethylhexamethylenediamine, 2,4,4-trimethylhexamethylenediamine, bis- (4,4'-aminocyclohexyl) methane, stubble diamine, and the like. Examples of the dibasic acids include glutaric acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecane dibasic acid, dodecane dibasic acid, hexadecane dibasic acid, and ten Hexene diacid, pinane diacid, diglycolic acid, 2,2,4-trimethyladipic acid, succinic dicarboxylic acid, 1,4-cyclohexanedicarboxylic acid Wait. Any of the crystalline polyamides used in the high heat-shrinkable polyamide fibers of the present invention may be used, but from the viewpoints of manufacturing cost and fiber strength maintenance, polydecamide and polyhexamethylene Diamine.

The highly heat-shrinkable polyamide composite fiber of the present invention is a composite fiber composed of polyamide (A) containing amorphous polyamide and polyamide (B) crystalline polyamide. This composite morphology is a fitted type or an eccentric core-sheath type. By adopting a fit type or an eccentric core-sheath type, it is convenient to use the poor viscosity or shrinkage of polyamide (A) and polyamide (B) to show crimping, thereby improving crimpability and making the fabric fluffy. Was good.

The thermal shrinkage stress of the highly heat-shrinkable polyamidamine composite fiber of the present invention is 0.15 cN / dtex or more. The "heat shrinkage stress" herein refers to a KE-2 type heat shrinkage stress measuring machine manufactured by Kanebo Engineering, which connects the fiber threads to be measured into a loop with a circumference of 16 cm, and applies a yarn fineness (dtex). / 30g initial load, measure the temperature when the temperature rises from room temperature to 100 ° C / min to 210 ° C at a heating rate of 100 ° C / min, and change the temperature, and measure the peak value of the obtained thermal stress curve, and set it as the maximum thermal stress (cN / dtex ). By setting the thermal shrinkage stress of the highly heat-shrinkable polyamide composite fiber within this range, even if moist heat and dry heat are applied under a state of high tension in the warp direction, the stress that is superior to the restraint force of the fabric will be used for contraction. It can fully show the crimpability in the warp direction, and can obtain a fabric with good stretchability and fluffy feel. If the heat shrinkage stress is less than 0.15 cN / dtex, sufficient curling does not occur in the wet heat step in which high tension is applied, and thus it becomes a woven fabric having poor stretchability and bulkiness. The thermal shrinkage stress is preferably 0.20 cN / dtex or more, and more preferably 0.25 cN / dtex or more. In addition, if the heat shrinkage stress is too high, the pores at the interlaced points of the fabric are likely to be blocked and the stretchability is hindered. Therefore, the upper limit of the heat shrinkage stress is preferably 0.50 cN / dtex.

The highly shrinkable polyamide fiber of the present invention preferably has a rigid amorphous amount of 17 to 35%. The rigid amorphous amount is a value calculated as follows. Using the difference between the heat of fusion obtained from the usual DSC measurement and the heat of cold crystallization (△ Hm- △ Hc) and the specific heat difference (△ Cp) obtained from the temperature-modulated DSC measurement, assuming that the crystalline polyamine content is 100%, The degree of crystallinity (Xc) and the amount of movable amorphous matter (Xma) were obtained according to the formulae (1) and (2). In addition, the rigid amorphous amount (Xra) was calculated using the formula (3). In addition, the rigid amorphous amount was measured by temperature-adjusting DSC and DSC twice, and then calculated from the average value.

Xc (%) = (△ Hm- △ Hc) / △ Hm ° × 100 (1)

Xma (%) = △ Cp / △ Cp ° × 100 (2)

Xra (%) = 100- (Xc + Xma) (3)

Among them, △ Hm ° and △ Cp ° are respectively the melting heat of crystalline polyamide and the specific heat difference of amorphous polyamide before and after Tg.

The thermal shrinkage stress of the highly heat-shrinkable polyamide composite fiber of the present invention depends on the binding force of the rigid amorphous chain when the fiber structure is formed, and the shrinkage of the movable amorphous chain that appears when heat treatment is performed. By setting the rigid amorphous amount of the highly heat-shrinkable polyamide composite fiber within this range, thermal shrinkage stress can be exhibited. By setting the amount of rigid amorphous to 17% or more, it is possible to obtain a required thermal shrinkage stress while showing the restraint of the rigid amorphous chain without causing damage and shrinkage of the movable amorphous chain. In addition, by setting it to 35% or less, the restraint force of the rigid amorphous chain can be exhibited, and the shrinkage force of the movable amorphous chain can be maintained, so that a desired thermal shrinkage stress can be obtained. Rigid amorphous content is more preferably 20 ~ 32%.

The highly heat-shrinkable polyamidamine composite fiber of the present invention preferably has an elongation and expansion ratio of 20 to 80%. By setting the elongation and expansion ratio of the polyamide composite fiber within this range, sufficient crimping can be developed, and a fabric having good stretchability and a fluffy feeling can be obtained. Although the higher the elongation and expansion ratio, the more the crimpability is increased, but in order to suppress the wrinkle, the manufacturing is performed under a high tension in the warp direction, which makes it easy to suppress the stretchability and fluffy feeling of the fabric, so the elongation and expansion ratio is better. 20 ~ 70%.

The high heat-shrinkable polyamidamine composite fiber of the present invention preferably has a total fineness of 20 to 120 dtex. In particular, when used as sportswear, down jackets, outer linings, and inner linings, from the viewpoint of fabric strength, it is more preferably 40 to 90 dtex.

For the high elongation of the high heat shrinkable polyamide composite fiber of the present invention, when the clothing is used, as long as it is generally used, the elongation of 25-50% and the strength of 2.5 are better from the viewpoint of high-end processing cN / dtex or more.

Here, the boiling water shrinkage of the highly heat-shrinkable polyamidamine composite fiber is preferably 25 to 50%. By setting it within this range, sufficient curling can be exhibited, and a fabric with good stretchability and fluffy feel can be obtained.

A method for manufacturing the high heat-shrinkable polyamidamine composite fiber of the present invention by melt spinning will be described. In the method for producing a highly heat-shrinkable polyamide compound fiber, the melt viscosity ratio (A / B) of polyamide (A) and polyamide (B) is preferably set to 0.7 to 1.5. By setting it as this range, the polyamide (A) and the polyamide (B) will show a difference in shrinkage, and the crimpability will be improved, so the fluffy feeling of the fabric will be good.

In the highly heat-shrinkable polyamidamine composite fiber of the present invention, the shape of the interface between the polyamidamine (A) and the polyamidamine (B) is not particularly limited. In the case of the eccentric core-sheath type, the core component polyamide is covered with the sheath component polyamine, and the distance between the center of gravity of the core component and the sheath component polyamine is preferably cut by the cross-section length of the line connecting the two component centers of gravity. 1/8 ~ 1/2. The composite ratio of polyamide (A) and polyamide (B) is preferably polyamine (A): polyamine (B) = 2: 1 to 1: 2 (weight ratio).

In the polyamide (A) constituting the highly heat-shrinkable polyamide compound fiber of the present invention, the weight ratio of the amorphous polyamide is 10% or more. By setting this range, a higher heat shrinkage stress can be obtained. When the weight ratio of the amorphous polyamine in the polyamide (A) is less than 10%, the heat shrinkage stress is small, and a fabric having good stretchability and bulkiness cannot be obtained. In addition, the higher the weight ratio of the amorphous polyamide, the higher the boiling water shrinkage rate as well as the thermal shrinkage stress. Therefore, the dimensional change becomes large, and the holes at the interlaced points of the fabric are easily blocked, so there is a possibility that the stretchability is suppressed. From the viewpoint of fabric stretchability, the weight ratio of the amorphous polyamide in the polyamide (A) is preferably 10 to 50% or less, and more preferably 20 to 40%.

Here, the "amorphous polyamide weight ratio in polyamide (A)" means that the polyamide (A) is divided into the polyamide (A) high heat-shrinkable polyamide composite fiber and The proton NMR was measured, and the peak area (A) derived from the hydrogen signal at the carboxyl alpha position (usually around 3 ppm) derived from the amine bond and the peak area (B) derived from the aromatic hydrocarbon signal (usually around 7 ppm) were obtained Repetition ratio of crystalline polyamines to amorphous polyamines (A = repeating number of amorphous polyamides × 2 + repeating number of crystalline polyamides × 2, B = repeating number of amorphous polyamides × 4). Similarly, the polyamide (A) constituting the high heat-shrinkable polyamide composite fiber was subjected to mass analysis, and the mass of the polyamide repeat unit was measured. The weight ratio was calculated from the product of the obtained repeat ratio and the mass number of each polyamine repeat unit.

Furthermore, if necessary, polyamine (A) can be added: pigments, heat stabilizers, antioxidants, weathering agents, flame retardants, plasticizers, release agents, slip agents, foaming agents, antistatic agents. , Formability improvers, strengthening agents, etc.

The polyamide (A) of the highly heat-shrinkable polyfluorene composite fiber of the present invention is a mutually soluble system in which amorphous polyamine and crystalline polyamine are mutually compatible. The miscibility system and the immiscibility system are judged based on the TEM observation results of 3000 times. If an island phase separation structure with a dispersed phase with a diameter of 10 nm or more is observed, it is judged as an "immiscible system". The sea-phase separation structure of the above dispersed phases is judged as a "miscible system". In a miscible system, the amorphous polyamidine and crystalline polyamidine phases are entangled, so that the binding force of the rigid amorphous chain is displayed, and the shrinkage of the movable amorphous chain is not impaired, and a higher Thermal shrinkage stress. On the other hand, in a non-miscible system, since the restraint force of the rigid amorphous chain is weak, a high heat shrinkage stress cannot be obtained.

The method of mixing the amorphous polyamide chip and the crystalline polyamide chip, which belong to the polyamide (A), involves melting using a pressure melter, a uniaxial extruder, and a biaxial extruder. Mixing method. In order to make the polyamide (A) form a miscible system and obtain higher heat shrinkage stress, a uniaxial extruder is preferably used. If a pressure melter is used, because the fragments are not uniformly mixed with each other, a phase separation structure of the islands is formed, and a high heat shrinkage stress cannot be obtained. When a biaxial extruder is used, the amorphous polyamide and the crystalline polyamine react excessively, resulting in a decrease in the amount of rigid amorphous, and a high heat shrinkage stress cannot be obtained.

Aiming at the method for manufacturing the high heat-shrinkable polyamidamine composite fiber of the present invention, it is: a method of continuously performing a spinning-drawing step (direct spinning drawing method), and a method of winding up undrawn yarn before performing drawing (two steps) Any method such as a high-speed spinning method (high-speed spinning method) or a high-speed spinning speed of 3000 m / min or more and a substantial omission step can be produced, but from the viewpoint of high-efficiency production and manufacturing cost, it is preferable A single-step method of the direct spinning stretching method and the high-speed spinning method.

Hereinafter, the manufacturing by the direct spinning drawing method of melt spinning is illustrated.

Polyamide (A) and polyamine (B) are melted at a temperature that is 20 to 60 ° C higher than the melting point of crystalline polyamine, and then spin-bonded or eccentric core-sheath composite fibers are spun. Mouth, spit out from the spinneret. The discharged polyamide composite yarn system is cooled and solidified in the same manner as ordinary melt spinning. After being supplied with oil, it is pulled by the first godet roller at 1500 to 4000 m / min. After the extension between the two godet rollers is performed at 1.0 to 3.0 times, the bobbin is wound up at 3000 m / min or more, preferably at 3500 to 4500 m / min.

At this time, by appropriately designing the peripheral speed ratio (extension ratio) and the winding speed (winder speed) between the first godet roller and the second godet roller, the strength of the target polyamide composite yarn can be obtained. Stretch.

In addition, by setting the first godet roller as a heating roller and performing thermal stretching, the fluidity of the polymer is improved, the rigid amorphous amount of the polyamide (A) is increased, and the heat shrinkage stress is increased. The heat elongation temperature is preferably 130 to 160 ° C, and more preferably 140 to 160 ° C.

Furthermore, by setting the second godet roller as a heating roller and performing heat setting, the heat shrinkage stress of the yarn can be appropriately designed. The heat setting temperature is preferably 130 to 180 ° C.

In addition, the steps up to the winding are all performed using a known associating device, and associating may also be performed. If necessary, the number of contacts can be increased by performing a plurality of contacts.

It is also possible to apply an oil solution by adding it immediately before winding.

The processing yarn of the present invention uses at least a part of the highly heat-shrinkable polyamidamine composite fiber of the present invention. The processing wire can be processed according to a known method. The method of the silk processing is not limited, and examples thereof include a knitting method and a false twist processing method. The mixed fiber method can adopt air mixed fiber, twisted yarn, composite false twist, etc. From the viewpoint of easy control of mixed fiber and low manufacturing cost, the preferred method is air mixed fiber. The false twist processing method is preferably performed in accordance with the fineness or the number of twists: needle type, friction type and belt type.

The knitted fabric of the present invention uses at least a part of the highly heat-shrinkable polyamidamine composite fiber or processed yarn of the present invention. Even when high tension is applied in the warp direction in the moist heat step, curling can be sufficiently developed, and a knitted fabric having good stretchability and a fluffy feel can be provided.

The knitted fabric system of the present invention can be woven and knitted according to a known method. The structure of the knitted fabric is not limited. In the case of fabrics, the structure of the fabric can be plain weave, twill weave, satin weave, or any of these altered or mixed weaves, depending on the application used. In order to obtain a fabric with a clear and fluffy texture, A good lineage is a plain weave structure with a lot of restraint points, or a combination of plain weave structure, stone texture, and basket-like tissue. In the case of knitted fabrics, the structure is arbitrarily flat-knitted, double-ribbed, half-knitted, satin, jacquard texture, or the like, depending on the application used. From the viewpoint of thin, stable, and excellent elongation of the woven fabric, the mixed structure is preferably a semi-woven fabric of a single tricot knitted fabric.

The use of the knitted fabric of the present invention is not limited, and it is preferably used for clothing, and more preferably: down jacket, windshield jacket, golf clothing, rain wear and other sports and leisure clothing; and women's / men's clothing . Particularly suitable for sportswear and down jackets.

    [Example]    

Next, the present invention will be described in detail using embodiments.

    A. Melting point    

Thermal analysis was performed using Q1000 manufactured by TA Instrument, and data processing was performed using Universal Analysis2000. The thermal analysis was performed under a nitrogen flow (50 mL / min) at a temperature range of -50 to 300 ° C, a heating rate of 10 ° C / min, and a weight of the fragment sample of about 5 g (the thermal data was formatted by the weight after measurement). The melting point is determined from the melting spike.

    B. Relative viscosity    

0.25 g of a polyamine fragment sample and 25 ml of a sulfuric acid solution having a concentration of 98% by mass were dissolved to 1 g / 100 ml, and the Ostrawa viscometer was used to measure the flow-down time (T1) at 25 ° C. Next, the downflow time (T2) with only 98 mass% sulfuric acid was measured. Let the ratio of T1 to T2, that is, T1 / T2 be the relative viscosity of sulfuric acid.

    C. Melt viscosity    

1.0 g of polyamine fragment sample in the die Under the conditions of 0.5 × 2.0 mm, a plunger of 1 cm ² , a temperature of 275 ° C., and a load of 200 N, the measurement was performed using a flow tester CFT-500 manufactured by Shimadzu Corporation.

    D. Total fineness    

According to JIS L1013. The fiber sample was made into a 200-strand skein with a 1/30 (g) tension using a length measuring machine with a yarn frame circumference of 1.125 m. Dry at 105 ° C for 60 minutes and move to a dryer. Allow to cool for 30 minutes at 20 ° C and 55% RH. Measure the weight of the skein. Calculate the weight per 10,000m from the obtained value. Set the nominal moisture regain to 4.5%. Calculate the total fineness of the fiber. The measurement system was performed 4 times, and the average value was made into the total fineness.

    E. Boiling water shrinkage    

The fiber sample was formed into a loop of 50 cm, and an initial load of 1/30 (g) of the fineness was applied to obtain the length A. Then, the fiber sample was immersed in boiling water for 30 minutes in an unapplied state, and then dried naturally. 30 (g) initial load and length B is calculated according to the following formula.

Boiling water shrinkage (%) = [(A-B) / A] × 100

    F. Thermal shrinkage stress    

A KE-2 type heat shrinkage stress measuring machine manufactured by Kanebo Engineering was used to connect the measured fiber sample (filament) into a ring with a circumference of 16 cm. An initial load of 1/30 g of the fineness of the filament was applied, and the measurement was performed at a temperature increase rate of 100 ° C / The load at the time of changing the temperature from room temperature to 210 ° C. was set, and the peak of the obtained thermal stress curve was taken as the thermal shrinkage stress.

    G. Elongation    

The fiber sample was wound with a skein, immersed in boiling water for 15 minutes, and air-dried. A load of 0.002 cN / dtex was applied to obtain the length A, and then a load of 0.3 cN / dtex was used to obtain the length B. The calculation was performed according to the following formula.

Elongation (%) = [(B-A) / B] × 100

    H. Rigid amorphous content    

Using the difference between the heat of fusion obtained from the usual DSC measurement and the heat of cold crystallization (△ Hm- △ Hc) and the specific heat difference (△ Cp) obtained from the temperature-modulated DSC measurement, assuming that the crystalline polyamine content is 100%, The degree of crystallinity (Xc) and the amount of movable amorphous matter (Xma) were obtained according to the formulae (1) and (2). In addition, the rigid amorphous amount (Xra) was calculated using the formula (3). In addition, the amount of rigid amorphous was calculated from the average of the DSC and DSC two times that the measurement temperature was adjusted.

Xc (%) = (△ Hm- △ Hc) / △ Hm ° × 100 (1)

Xma (%) = △ Cp / △ Cp ° × 100 (2)

Xra (%) = 100- (Xc + Xma) (3)

Among them, △ Hm ° and △ Cp ° are respectively the melting heat of crystalline polyamide and the specific heat difference of amorphous polyamide before and after Tg.

In addition, the measurement conditions of DSC and temperature-modulated DSC are generally implemented under the following conditions.

    (a) Normally DSC    

A differential scanning calorimeter (DSC) uses Q1000 manufactured by TA Instrument to perform thermal analysis, and uses Universal Analysis 2000 to perform data processing. The thermal analysis was performed under a nitrogen flow (50 mL / min) at a temperature range of -50 to 300 ° C, a heating rate of 10 ° C / min, and a fiber sample weight of about 5 g (the thermal data was formatted by the weight after measurement).

    (b) Temperature Modulation DSC    

A differential scanning calorimeter (DSC) uses Q1000 manufactured by TA Instrument to perform thermal analysis, and uses Universal Analysis 2000 to perform data processing. Thermal analysis is under nitrogen flow (50mL / min), according to temperature range -50 ~ 270 ℃, heating rate 2 ℃ / min, temperature modulation cycle 60 seconds, temperature modulation amplitude ± 1 ℃, fiber sample weight about 5g (heat Data are formatted by weight after measurement).

This method is a method of measuring while repeating heating and cooling with a certain period and amplitude, and heating up evenly. The entire DSC signal (Total Heat Flow) can be separated into reversing components such as glass transition (Reversing). Heat Flow (reversible heat flow), irreversible components such as relaxation with enthalpy, hardening reaction, solvent removal (Nonreversing Heat Flow, irreversible heat flow). However, melting peaks of crystals appear in both reversible and irreversible components.

    I. Weight ratio of amorphous polyamide and crystalline polyamide         (a) NMR measurement    

The measurement was performed by using nuclear magnetic resonance spectrometry ( ¹ H-NMR) with tetramethylsilane (TMS) as an internal standard substance (0 ppm). Amorphous polyfluoreneamine is obtained from the peak area (A) of the hydrogen signal at the carboxyl alpha position (usually around 3 ppm) and the peak area (B) of the signal derived from aromatic hydrocarbons (usually around 7ppm). Repetition ratio with crystalline polyfluorene (A = amorphous polyfluorene repeat number × 2 + crystalline polyfluorene repeat number × 2, B = amorphous polyamine repeat number × 4).

    (b) Quality analysis    

Use matrix-assisted laser desorption / free mass spectrometry (MALDI-MS), time-of-flight mass spectrometry (TOF-MS), time-of-flight matrix-assisted laser desorption / free mass spectrometry (MALDI-TOF-MS), decide Mass number of amorphous polyfluorene and crystalline polyfluorene repeat units.

    (c) Weight ratio    

Weight ratio of amorphous polyamide (%) = (A / 2-B / 4) × (mass of amorphous polyamide)

Weight ratio of crystalline polyamide (%) = (A / 2) × (mass of crystalline polyamide)

    J. Miscibility    

The fiber yarn was exposed to RuO ₄ vapor, and the application line was coated so that the boundary between the yarn and the embedding resin was clear. Then, thin sections were embedded in the resin, and stained with an aqueous solution of phosphotungstic acid (PTA) for 15 minutes. The observation object obtained as described above was observed with a transmission electron microscope (H-7100 manufactured by Hitachi, Ltd.) at a thin section at a voltage of 100 kV. Observe the cross section of the fiber at an observation magnification of 3000 times. From the TEM observation results, it was judged as an "immiscible system" (×) when an island phase separation structure with a dispersed phase with a diameter of 10 nm or more was observed, and it was judged as an island phase separation structure with a dispersed phase with a diameter of 10 nm or more not observed. "Mutually soluble system" (○).

    K. Strength and elongation    

The fiber samples were measured using "TENSILON" (registered trademark), UCT-100, manufactured by ORIENTEC, under constant-speed elongation conditions shown in JIS L1013 (Chemical Fiber Silk Yarn Test Method, 2010). The elongation is calculated from the stretch at the maximum strength in the tensile strength-extension curve. The intensity is a value obtained by dividing the maximum strength by the fineness. The measurement system was performed 10 times, and the average value was made into intensity and elongation.

    L. Manufacture of processed silk         (a) Manufacturing of nylon 6 silk thread    

Polycaprolactam (N6) (relative viscosity 2.70, melting point 222 ° C) was melt-discharged from a spinning spinneret provided with 60 spinneret discharge holes at 275 ° C. After being melted and discharged, the yarn discharged from the spinneret is cooled and solidified by the yarn cooling device, and then the oil supply device is used to supply the non-aqueous oil agent. After the intersection is provided by the fluid intersection nozzle device, the first godet roller ( Elongation temperature: room temperature) After being pulled for 1.7 times during heating of the second godet (heat setting temperature: 155 ° C), the yarn is wound into a bobbin at a winding speed of 4000 m / min, and 80 dtex60 monofilament nylon 6 silk threads. In addition, the obtained nylon 6 wire system had a strength of 4.0 cN / dtex, an elongation of 59%, a boiling water shrinkage of 10%, and a heat shrinkage stress of 0.09 cN / dtex.

    (b) Manufacturing of processed silk    

The nylon 6 yarn obtained in the above (a) and the polyamide composite yarn obtained in Examples 1 to 7 and Comparative Examples 1 to 7 were subjected to an interlacing treatment with an interlacing pressure of 2.0 kg / cm ² using an interlacing machine to perform mixing. Fiber processing to obtain 150dtex processed yarn.

    M. Fabric Evaluation         (a) Manufacturing of weft    

Polycaprolactam (N6) (relative viscosity 2.70, melting point 222 ° C) was melt-discharged from a spinning spinneret provided with 12 spinneret discharge holes at 275 ° C. After being melted and discharged, the yarn was cooled, supplied with oil, and entangled, then pulled by a 2560m / min godet roller, and then stretched by 1.7 times, then thermally fixed at 155 ° C, and 70dtex12 monofilament was obtained at a winding speed of 4000m / min Nylon 6 silk thread.

    (b) Fabrication    

The polyamide composite yarns obtained in Examples 1 to 7 and Comparative Examples 1 to 7 were used as warp yarns (warp yarn density 90 pieces / 2.54 cm), and the nylon 6 yarns obtained in (a) above were used as weft yarns (weft yarn density 90). /2.54cm), weaving a plain fabric (warp yarn / composite fiber) (apparent density 40g / cm ² ).

Furthermore, the processed yarn containing the polyamide composite yarns obtained in Examples 1 to 7 and Comparative Examples 1 to 7 was used as a warp yarn (warp yarn density 90 pieces / 2.54 cm), and nylon 6 obtained in (a) above was used. As the yarn, weft yarns (weft density of 90 counts / 2.54 cm) were used, and plain fabrics (warp yarns / processed yarns) were woven (apparent density of 40 g / cm ² ).

The obtained fabric was refined at 80 ° C for 20 minutes, then adjusted to pH 4 with Kayanol Yellow N5G 1% owf, acetic acid, and then dyeed at 100 ° C for 30 minutes, and then fixed at 80 ° C for 20 minutes. Heat treatment was performed at 170 ° C for 30 seconds.

    (c) Elongation (stretchability) in the warp direction of the fabric    

A tensile tester was used to measure the elongation when a fabric sample having a width of 50 mm × 300 mm was extended toward the warp direction of the fabric at a gripping interval of 200 mm and a stretching speed of 200 mm / min to 14.7 N. Evaluation was performed in accordance with the following five stages. A score of 3 or more is rated "Stretchable".

5 points: 25% or more

4 points: 20% or more and less than 25%

3 points: 15% or more and less than 20%

2 points: more than 10% and less than 15%

1 point: less than 10%

    (d) Evaluation of the fluffy feel of the fabric    

As for the fluffy feeling of the fabric, evaluation was performed in accordance with the following five stages using the touch of a skilled person (five), and the average of the evaluation points of each technical person was rounded to the nearest decimal point. A score of 3 or more is rated "with fluffy feeling".

5 points: very good

4 points: Excellent

3 points: slightly better

2 points: slightly worse

1 point: poor

    [Example 1]    

A polycondensate of an amorphous polyamidine isophthalic acid (6I) / terephthalic acid (6T) / hexamethylene diamine and a copolymerization ratio of isophthalic acid / terephthalic acid of 7/3, and Polycaprolactam (N6) (a relative viscosity ηr: 2.70, melting point 222 ° C.) of crystalline polyammine was mixed so that the weight ratio became 30/70 as polyammine (A). The crystalline polyamidoamine uses polycaprolactam (N6) (relative viscosity ηr: 2.63, melting point 222 ° C) as the polyamidoamine (B). The pieces of polyamide (A) and the pieces of polyamide (B) were melted at 275 ° C using a uniaxial extruder, respectively, and a spinneret (12 holes, round holes) for laminated composite wires was used. The composite ratio of polyamide (A) and polyamide (B) is melt-discharged according to polyamide (A): polyamine (B) = 1: 1 (spinning temperature: 275 ° C). The melt viscosity ratio of polyamide (A) / polyamine (B) is 1.25.

The yarn discharged from the spinneret is cooled and solidified by the yarn cooling device, and after the non-aqueous oil agent is supplied by the oil supply device, after the intersection is provided by the fluid intersection nozzle device, the first godet roller is heated (elongation temperature: 140 ° C) ), And then stretched to 2.4 times during heating of the second godet roller (heat setting temperature: 150 ° C), and then wound into a bobbin at a winding speed of 4000 m / min to obtain a 70 dtex 12 monofilament polyamide composite yarn.

    [Example 2]    

A polycondensate of an amorphous polyamidine isophthalic acid (6I) / terephthalic acid (6T) / hexamethylene diamine and a copolymerization ratio of isophthalic acid / terephthalic acid of 7/3, and Polycaprolactam (N6) (relative viscosity ηr: 2.70, melting point 222 ° C.) of crystalline polyamine, polyamine (A) mixed as a core component so that the weight ratio becomes 30/70. Polycaprolactam (N6) (relative viscosity ηr: 2.63, melting point 222 ° C) of crystalline polyamidamine was used as a sheath component. In addition to using an eccentric core-sheath type spinneret (12 holes, round holes), the polyamide (A) of the core component is covered with the polyamide (B) of the sheath component, and the polymerization of the core component and the sheath component is performed. The distance between the centers of gravity of the amidine was set to 1/4 of the cross-sectional length cut by the straight line connecting the two components, and the rest were spun in the same manner as in Example 1 to obtain a 70 dtex12 monofilament polyamide composite yarn.

    [Example 3]    

Polyhexamethylene sulfomamide (N610) (relative viscosity 2.66, melting point 218 ° C.) of crystalline polyamidamine was used as polyamidamine (B). The polyamide (A) was the same as in Example 1, and the melt viscosity ratio of the polyamide (A) / the polyamide (B) was 1.15. The first godet roller (elongation temperature: 140 ° C) was used for drawing, and the second godet roller (heat setting temperature: 150 ° C) was extended for 2.7 times. The rest were performed in the same manner as in Example 1. Spinning to obtain a 70 dtex 12 monofilament polyamide composite yarn.

    [Example 4]    

The polycondensate of amorphous polyfluorene terephthalic acid (6T) / 2,2,4-trimethylhexamethylene diamine and polycaprolactam (N6) of crystalline polyfluorene (relative viscosity ηr : 2.70, melting point 222 ° C) as Polyamidamine (A). The polyamide (B) was the same as in Example 1, and the melt viscosity ratio of the polyamide (A) / the polyamide (B) was 1.20. Further, spinning was performed in the same manner as in Example 1 except that the first godet roller was heated (elongation temperature: 130 ° C.) for drawing, and a 70 dtex 12 monofilament polyamide yarn was obtained.

    [Example 5]    

Polyamide (A) was prepared by mixing polyamines such that the weight ratio of amorphous polyamines and crystalline polyamines was 10/90. The melt viscosity ratio of polyamide (A) / polyamine (B) is 1.15. Except that the non-heated first godet roller (drawing temperature: 140 ° C.) was used for drawing, the spinning was performed in the same manner as in Example 1 to obtain a 70 dtex 12 monofilament polyamide composite yarn.

    [Example 6]    

Polyamide (A) was prepared by mixing polyamines such that the weight ratio of amorphous polyamines and crystalline polyamines was 50/50. The polyamide (A) / polyamine (B) has a melt viscosity ratio of 1.30. Except for drawing by heating the first godet roller (elongation temperature: 140 ° C.), spinning was performed in the same manner as in Example 1 to obtain a 70 dtex 12 monofilament polyamide composite yarn.

    [Example 7]    

Polyamide (A) was prepared by mixing polyamines such that the weight ratio of amorphous polyamines and crystalline polyamines was 60/40. The melt viscosity ratio of polyamide (A) / polyamine (B) is 1.35. Except for drawing by heating the first godet roller (elongation temperature: 140 ° C.), spinning was performed in the same manner as in Example 1 to obtain a 70 dtex 12 monofilament polyamide composite yarn.

    [Comparative Example 1]    

A polycondensate of an amorphous polyamidine isophthalic acid (6I) / terephthalic acid (6T) / hexamethylene diamine and a copolymerization ratio of isophthalic acid / terephthalic acid of 7/3, and Polycaprolactam (N6) (a relative viscosity ηr: 2.70, melting point 222 ° C.) of crystalline polyammine was mixed so that the weight ratio became 30/70 as polyammine (A). Except that the pieces of polyamide (A) were melted at 275 ° C using a pressure melter, spinning was performed in the same manner as in Example 1 to obtain a 70 dtex 12 monofilament polyamide composite yarn.

    [Comparative Example 2]    

A polycondensate of an amorphous polyamidine isophthalic acid (6I) / terephthalic acid (6T) / hexamethylene diamine and a copolymerization ratio of isophthalic acid / terephthalic acid of 7/3, and Polycaprolactam (N6) (a relative viscosity ηr: 2.70, melting point 222 ° C.) of crystalline polyammine was mixed so that the weight ratio became 30/70 as polyammine (A). Except that the pieces of polyamide (A) were melted at 275 ° C using a biaxial extruder, spinning was performed in the same manner as in Example 1 to obtain a polyamide composite yarn of 70 dtex12 monofilament.

    [Comparative Example 3]    

Polyhexamethylene (A) was polyhexamethylene cyanamide (N610) which was only crystalline polyamine (relative viscosity: 2.66, melting point: 218 ° C). The polyamide (A) / polyamine (B) has a melt viscosity ratio of 1.10. It was the same as in Example 1 except that it was pulled by heating the first godet roller (elongation temperature: 140 ° C) and stretched 2.7 times while heating the second godet roller (heat setting temperature: 170 ° C). Spinning was performed to obtain a 70 dtex 12 monofilament polyamide composite yarn.

    [Comparative Example 4]    

Polyamide (A) was obtained by mixing amorphous polyamide and crystalline polyamide in a weight ratio of 5/95. The polyamide (A) / polyamine (B) has a melt viscosity ratio of 1.05. Except for drawing by a non-heated first godet roller (elongation temperature: 140 ° C), spinning was performed in the same manner as in Example 1 to obtain a 70 dtex 12 monofilament polyamide composite yarn.

    [Comparative Example 5]    

Polyamide (A) was used as a mixture of amorphous polyamide and crystalline polyamide in a weight ratio of 30/70, and a first godet roller (extension temperature: room temperature) was used. Except for drawing, the rest were spun in the same manner as in Example 1 to obtain a 70 dtex 12 monofilament polyamide composite yarn.

    [Comparative Example 6]    

A polyamid (A) was used as the polyamidamine (A), except that polyamidine and crystalline polyamidide were mixed in a weight ratio of 30/70, and a first godet roller (extension temperature: 80 ° C) was used. Except for drawing, the rest were spun in the same manner as in Example 1 to obtain a 70 dtex 12 monofilament polyamide composite yarn.

    [Comparative Example 7]    

Polycaprolactam (N6) (relative viscosity ηr: 2.40, melting point 222 ° C) of crystalline polyfluorene was used as polyfluorene (B). The polyamide (A) is the same as in Example 1, and the melt viscosity ratio of the polyamide (A) / polyamine (B) is 1.40. In addition, spinning was performed in the same manner as in Example 1 except that the first godet roller (drawing temperature: 80 ° C.) was used for drawing, and a 70 dtex 12 monofilament polyamide composite yarn was obtained.

From the results in Table 2, it is known that the polyamide composite yarns or processed yarns of Examples 1 to 7 of the present invention are used as warp fabrics, and moist heat and dry heat are applied even when high tension is applied in the warp direction, because It shrinks under the stress of the fabric restraint, so it can fully show the crimpability, and can obtain good stretchability and fluffy feeling.

Comparative Example 1 Since amorphous polyamide chips and crystalline polyamide chips of polyamide (A) were melted using a pressure melter, polyamide (A) became a non-miscible system and the thermal shrinkage stress was not When it is over 0.15cN / dtex, the amount of rigid amorphous is reduced. Even if moist heat and dry heat are applied under the state of high tension in the warp direction, the binding force of the fabric is still better. Therefore, the crimpability cannot be fully displayed, and the stretchability and fluff cannot be obtained. sense.

Comparative Example 2 Since the amorphous polyamide chip and the crystalline polyamide chip of polyamide (A) were melted using a biaxial extruder, the thermal shrinkage stress was less than 0.15 cN / dtex, and the amount of rigidity was amorphous. Reduced, even if moist heat and dry heat are applied in the state where high tension is applied in the warp direction, the binding force of the fabric is still better, so the crimpability cannot be fully exhibited, and the stretchability and bulkiness cannot be obtained.

Comparative Example 3 Since the polyamide of polyamide (A) is only crystalline polyamide, the thermal shrinkage stress is less than 0.15 cN / dtex, and the amount of rigid amorphous material is reduced, even when the tension is applied in the warp direction Damp heat ‧ dry heat, the restraint of the fabric is still better, so the crimpability cannot be fully exhibited, and the stretchability and fluffy feeling cannot be obtained.

Comparative Example 4 Because the weight ratio of the amorphous polyamide of polyamide (A) is low, the thermal shrinkage stress is less than 0.15 cN / dtex, the amount of rigid amorphous is reduced, and the thermal shrinkage stress is low, even when applied in the warp direction When moist heat and dry heat are applied under high tension, the restraint of the fabric is still better, so the crimpability cannot be fully exhibited, and the stretchability and bulkiness cannot be obtained.

In Comparative Examples 5, 6, and 7, because the elongation temperature is low, the heat shrinkage stress is less than 0.15 cN / dtex, and the amount of rigid amorphous material is reduced. Even if humid heat and dry heat are applied under high tension in the warp direction, the fabric restraint force Because of this, the crimpability cannot be sufficiently developed, and the stretchability and bulkiness cannot be obtained.

Claims (6)

    A high heat-shrinkable polyamide compound fiber is a bonded or eccentric core-sheath type composite fiber composed of two kinds of polyamide (A) and polyamide (B) with mutually different compositions. Among them, polyamide ( A) contains amorphous polyamide, and polyamide (B) is crystalline polyamide, and the thermal shrinkage stress of the composite fiber is 0.15 cN / dtex or more.         The highly heat-shrinkable polyamidamine composite fiber according to claim 1, wherein the polyamidamine-based isophthalic acid / terephthalic acid / hexamethylenediamine is a polycondensate.         For example, the high heat shrinkable polyamide composite fiber of claim 1 or 2, wherein the rigid amorphous amount of the composite fiber is 17 to 35%.         The high heat-shrinkable polyamide composite fiber according to any one of claims 1 to 3, wherein the elongation and expansion ratio of the composite fiber is 20 to 80%.         A polyamide processing yarn is composed of the high heat shrinkable polyamide composite fiber according to any one of claims 1 to 4.         A knitted fabric comprising at least a part of the high heat shrinkable polyamide composite fiber according to any one of claims 1 to 4, or the polyamide processed yarn according to claim 5.