CN109072491B

CN109072491B - High heat-shrinkable polyamide fiber, and combined filament yarn and woven fabric using same

Info

Publication number: CN109072491B
Application number: CN201780027433.8A
Authority: CN
Inventors: 内山翔一朗; 佐藤贵大; 佐藤佳史
Original assignee: Toray Industries Inc
Current assignee: Toray Industries Inc
Priority date: 2016-05-26
Filing date: 2017-05-17
Publication date: 2021-10-29
Anticipated expiration: 2037-05-17
Also published as: TWI720200B; KR20190008181A; JPWO2017204047A1; CN109072491A; KR102272627B1; TW201816210A; WO2017204047A1

Abstract

The invention provides a fabric having a high-density feeling, a full feeling, and a soft feeling. A highly heat-shrinkable polyamide fiber having a glass transition temperature (Tg) of 85 to 95 ℃, a boiling water shrinkage (B) of 30 to 50%, and a heat shrinkage stress (H) of 0.20cN/dtex or more can be provided.

Description

High heat-shrinkable polyamide fiber, and combined filament yarn and woven fabric using same

Technical Field

The present invention relates to a polyamide fiber having high heat shrinkability, and a combined filament yarn and a fabric using the same.

Background

In recent years, there has been active development of sewn products such as woven fabrics using special fibers not found in the fibers so far. Among them, there are many examples in which fibers having high shrinkability are used, and for example, woven fabrics having bulkiness and fullness by weaving a mixed filament yarn in which 2 kinds of fibers having different heat shrinkability are mixed and then heat-treating with boiling water, steam or the like to improve hand and surface properties have been developed in large quantities.

A typical example of the fiber to which high shrinkability is imparted is a high-shrinkage polyester fiber, but since a polyester fiber has a higher young's modulus than a polyamide fiber, the hand after shrinkage by heat treatment is hard, and there is a problem in comfort in use as clothing. On the other hand, polyamide fibers are suitable for clothing applications because they have low young's modulus, soft hand, and excellent properties such as abrasion resistance, but many high-shrinkage polyamide fibers have been developed to provide further functions.

For example, patent document 1 discloses a highly shrinkable polyamide fiber having a boiling water shrinkage of 35% or more, which is composed of a crystalline polyamide and an amorphous polyamide. Further, patent document 2 discloses a highly shrinkable polyamide fiber having a boiling water shrinkage of 15% or more, which is formed from a crystalline polyamide and an amorphous polyamide. Further, patent document 3 discloses a highly shrinkable polyamide fiber having a heat shrinkage stress of 220 to 400 mg/d. Further, patent document 4 discloses a highly shrinkable polyamide fiber having a heat shrinkage stress of 0.15cN/dtex or more.

Documents of the prior art

Patent document

Patent document 1: japanese laid-open patent publication No. 4-2814

Patent document 2: japanese laid-open patent publication No. 3-64516

Patent document 3: japanese patent laid-open No. 2000-73231

Patent document 4: japanese laid-open patent publication No. 2007-100270

Disclosure of Invention

Problems to be solved by the invention

However, the high-shrinkage polyamide fibers disclosed in patent documents 1 and 2 have a high boiling water shrinkage rate but have a small shrinkage stress, and therefore, even when a fabric obtained by weaving or knitting the polyamide fibers is subjected to heat treatment, the fabric does not shrink sufficiently, and a woven fabric having a high density and a full feeling is not obtained.

The high-shrinkage polyamide fibers disclosed in patent documents 3 and 4 have high heat shrinkage stress, but have a glass transition temperature (Tg) close to room temperature, and therefore, if stored in a state where tension is not applied to the polyamide fibers of a woven fabric or the like, the heat shrinkage stress is reduced with time, and even if the woven fabric obtained by weaving or knitting the polyamide fibers is subjected to heat treatment, the shrinkage stress is small, and therefore, the polyamide fibers do not shrink sufficiently, and a woven fabric having a high density and a full feeling cannot be obtained.

Accordingly, the present invention has been made to solve the above problems, and an object thereof is to provide a polyamide fiber having high heat shrinkability and having high shrinkage characteristics such as heat shrinkage stress (H) and boiling water shrinkage (B), and a woven fabric using a combined filament yarn at least partially using the polyamide fiber having high heat shrinkability and having bulkiness and a woven fabric at least partially using the polyamide fiber and/or the combined filament yarn having high heat shrinkability, which is a woven fabric having a high density and a soft feeling.

Means for solving the problems

In order to achieve the above object, the high heat shrinkable polyamide fiber of the present invention has the following constitution.

(1) A high heat-shrinkable polyamide fiber characterized in that the glass transition temperature (Tg) is 85 to 95 ℃, the boiling water shrinkage (B) is 25 to 50%, and the heat shrinkage stress (H) is 0.20cN/dtex or more.

(2) The high heat-shrinkable polyamide fiber according to (1), wherein the total fineness is 5 to 80dtex and the single-fiber fineness is 0.9 to 3.0 dtex.

(3) A combined filament yarn characterized by using the highly heat-shrinkable polyamide fiber according to (1) or (2) as at least a part of the combined filament yarn.

(4) A fabric characterized in that at least a part of the fabric is provided with the high heat shrinkable polyamide fiber (1) or (2) and/or the combined filament yarn (3).

ADVANTAGEOUS EFFECTS OF INVENTION

The high heat-shrinkable polyamide fiber of the present invention has excellent shrinkage characteristics due to high heat shrinkage stress (H) and boiling water shrinkage (B), has a high glass transition temperature (Tg), and does not have a decrease in heat shrinkage stress with time, and therefore, a mixed filament yarn using the high heat-shrinkable polyamide fiber in at least a part thereof has bulkiness, and a woven fabric using the polyamide fiber and/or the mixed filament yarn having high heat shrinkability in at least a part thereof can be a woven fabric having a high density with a rich and soft feel.

Detailed Description

The high heat-shrinkable polyamide fiber of the present invention is a fiber formed using a crystalline polyamide and an amorphous polyamide.

The crystalline polyamide is a polyamide which forms crystals and has a melting point, and is a polymer in which so-called hydrocarbon groups are linked to the main chain via amide bonds, and examples thereof include polycaprolactam, polyhexamethylene adipamide, polyhexamethylene sebacamide, polytetramethylene adipamide, polycondensation type polyamide of 1, 4-cyclohexanedi (methylamine) and a linear aliphatic dicarboxylic acid, copolymers thereof, and mixtures thereof. However, from the viewpoint of easy reproducibility of a homogeneous system and stable function, it is preferable to use a homopolymeric polyamide.

The crystalline polyamide is preferably formed from diamines and dibasic acids, and specific diamines include tetramethylenediamine, hexamethylenediamine, nonamethylenediamine, undecamethylenediamine, dodecamethylenediamine, 2, 4-trimethylhexamethylenediamine, 2,4, 4-trimethylhexamethylenediamine, bis- (4, 4' -aminocyclohexyl) methane, m-xylylenediamine, and the like. Examples of the dibasic acids include glutaric acid, pimelic acid, adipic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, hexadecanedioic acid, eicosanedioic acid, diglycolic acid, 2, 4-trimethyladipic acid, xylylenedicarboxylic acid, and 1, 4-cyclohexanedicarboxylic acid. The crystalline polyamide used for the high heat-shrinkable polyamide fiber of the present invention may be any crystalline polyamide, but polycaprolactam or polyhexamethylene adipamide is preferable from the viewpoint of both production cost and strength retention of the fiber.

The non-crystalline polyamide in the high heat shrinkable polyamide fiber of the present invention is a polyamide which does not form crystals and has no melting point, and examples thereof include a polycondensate of isophthalic acid/terephthalic acid/hexamethylenediamine, a polycondensate of isophthalic acid/terephthalic acid/hexamethylenediamine/bis (3-methyl-4-aminocyclohexyl) methane, a polycondensate of isophthalic acid/2, 2, 4-trimethylhexamethylenediamine/2, 4, 4-trimethylhexamethylenediamine, a polycondensate of terephthalic acid/2, 2, 4-trimethylhexamethylenediamine/2, 4, 4-trimethylhexamethylenediamine, an polycondensate of isophthalic acid/terephthalic acid/2, 2, 4-trimethylhexamethylenediamine/2, 4, 4-trimethylhexamethylenediamine, isophthalic acid/bis (3-methyl-4-aminocyclohexyl) methane/ω -laurolactam, terephthalic acid/bis (3-methyl-4-aminocyclohexyl) methane/ω -laurolactam, and the like. Further, the polyamide may contain a polyamide in which the benzene ring of the terephthalic acid component and/or isophthalic acid component constituting the condensation polymer is substituted with an alkyl group or a halogen atom. Further, these amorphous polyamides may be used in 1 kind, or 2 or more kinds may be used in combination. The amorphous polyamide used for the high heat-shrinkable polyamide fiber of the present invention is preferably a polycondensate of isophthalic acid/terephthalic acid/hexamethylenediamine from the viewpoint of having a high glass transition temperature (Tg).

In the high heat-shrinkable polyamide fiber of the present invention, the weight ratio of the crystalline polyamide to the amorphous polyamide is 90/10 to 50/50. When the weight ratio of the amorphous polyamide is less than 10% by weight, shrinkage characteristics of heat shrinkage stress (H) and boiling water shrinkage (B) become small, and when a combined filament yarn is produced, a difference in filament length is unlikely to occur even if a heat treatment is performed, and sufficient bulkiness cannot be obtained. Further, if the weight ratio of the amorphous polyamide exceeds 50% by weight, the drawability is poor and the yarn cannot be stably produced. Therefore, the polyamide is preferably a crystalline polyamide/amorphous polyamide in a range of 80/20 to 60/40, and more preferably in a range of 70/30 to 60/40.

The weight ratio referred to herein is a ratio of repetition of the crystalline polyamide to the amorphous polyamide (a is the repetition number of the crystalline polyamide × 2+ the repetition number of the amorphous polyamide × 2, and B is the repetition number of the amorphous polyamide × 4) obtained by measuring proton NMR of the high heat-shrinkable polyamide fiber from a peak area (a) of a signal derived from hydrogen at a position α to a carboxyl group forming an amide bond (usually around 3 ppm) and a peak area (B) of a signal derived from an aromatic hydrocarbon (usually around 7 ppm). The mass number of the repeating unit of the polyamide was measured by mass spectrometry for the same high heat-shrinkable polyamide fiber. The weight ratio is calculated from the product of the determined repetition ratio and the mass number of the repeating unit of each polyamide.

In addition, pigments, heat stabilizers, antioxidants, weather resistant agents, flame retardants, plasticizers, mold release agents, lubricants, foaming agents, antistatic agents, moldability improvers, reinforcing agents, and the like may be added to the high heat shrinkable polyamide fibers as necessary.

The high heat shrinkable polyamide fiber of the present invention is a compatible system in which crystalline polyamide and amorphous polyamide are compatible with each other. The judgment of the compatible system and the incompatible system is that, in the TEM observation result of 3000 times, the incompatible system is judged when the phase separation structure of the sea and island having the dispersed phase with the diameter of 10nm or more is observed, and the compatible system is judged when the phase separation structure of the sea and island having the dispersed phase with the diameter of 10nm or more is not observed. In the compatibilization system, the amorphous polyamide and the crystalline polyamide are entangled with each other at the time of forming a fiber structure, whereby a high strain band can be formed in the amorphous portion of the crystalline polyamide, and a desired boiling water shrinkage ratio (B) and a desired heat shrinkage stress (H) can be exhibited.

The glass transition temperature (Tg) of the high heat-shrinkable polyamide fiber is 85-95 ℃. The glass transition temperature (Tg) of the polyamide fiber having high thermal shrinkage stress of the present invention is an index of reactivity of the crystalline polyamide with the amorphous polyamide, and depends on formation of a high strain zone generated in an amorphous portion of the crystalline polyamide when forming a fiber structure. When the glass transition temperature (Tg) is in such a range, a desired thermal shrinkage stress (H2) can be exhibited over time even when the polyamide fiber is stored in a state where no tension is applied. When the glass transition temperature (Tg) is less than 85 ℃, a high strain band generated in the amorphous portion of the crystalline polyamide is relaxed, and therefore, if the polyamide fiber is stored in a state where no tension is applied, a desired thermal shrinkage stress over time is not obtained (H2). If the glass transition temperature (Tg) exceeds 95 ℃, the amorphous polyamide and the crystalline polyamide excessively react and the crystal size becomes small, so that although the initial heat shrinkage stress (H) is high, the desired heat shrinkage stress over time cannot be obtained if the polyamide fiber is stored in a state in which no tension is applied (H2). The glass transition temperature (Tg) of the highly heat-shrinkable polyamide fiber is preferably 87 to 93 ℃. The heat shrinkage stress (H2) of the high heat-shrinkable polyamide fiber with time is preferably 0.20cN/dtex or more, more preferably 0.25cN/dtex or more, and most preferably 0.30cN/dtex or more. Further, if the heat shrinkage stress is too high, the force for shrinkage becomes too high when producing the woven fabric, and the eyes of the cross points of the woven fabric are excessively closed, so that the woven fabric is not resistant to friction, and feathers, hair balls, and the like are likely to be generated, and thus the quality of the woven fabric obtained tends to be lowered. Therefore, the upper limit of the thermal shrinkage stress (H2) of the highly heat-shrinkable polyamide fiber with time is preferably 0.50 cN/dtex.

The boiling water shrinkage (B) of the high heat-shrinkable polyamide fiber is 25 to 50%. When the combined yarn is produced in such a range, a difference in yarn length occurs due to a difference in shrinkage of the fiber, which is different from the shrinkage characteristics, when the combined yarn is heat-treated with boiling water, steam, or the like, and a bulky combined yarn can be obtained. In addition, when the woven fabric is produced, the woven fabric is sufficiently shrunk by heat treatment with boiling water, steam, or the like, and a woven fabric having a high density and a full feeling can be obtained. When the boiling water shrinkage ratio (B) is less than 25%, a difference in filament length is unlikely to occur even if heat treatment is performed in the production of the combined filament yarn, and sufficient bulkiness cannot be obtained, and further, even if heat treatment is performed in the production of woven fabric, shrinkage is not sufficient, and a high-density woven fabric having a full-bodied feeling and a soft feeling cannot be obtained. If the boiling water shrinkage ratio (B) exceeds 50%, dimensional changes become excessive during heat treatment in the production of woven fabrics, the woven fabrics become too dense in density, hard in texture, and poor in fullness and softness, and in addition, the cross points of woven fabrics are clogged with eyes to cause unevenness and uneven shrinkage, thereby resulting in poor quality of the woven fabrics obtained. The boiling water shrinkage (B) of the highly heat-shrinkable polyamide fiber is preferably 30 to 45%. The boiling water shrinkage (B) here is calculated by applying an initial load of 1/30(g) in fineness to a 50cm loop of a fiber sample to obtain a length a, immersing the fiber sample in boiling water for 30 minutes in a non-applied state, drying the fiber sample naturally, applying an initial load of 1/30(g) in fineness to obtain a length B, and calculating the boiling water shrinkage (B) from the following equation.

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

The heat-shrinkable polyamide fiber of the present invention has a heat-shrinkable stress (H) of 0.20cN/dtex or more. The heat shrinkage stress (H) was measured by connecting the measured fiber filaments to form a coil having a circumference of 16cm using a KE-2 heat shrinkage stress measuring apparatus manufactured by カネボウエンジニアリング, applying an initial load of 1/30g of the fineness (dtex) of the filaments, measuring the load when the temperature was changed at a temperature increase rate of 100 ℃/min, and determining the peak (maximum) of the obtained heat stress curve as the heat shrinkage stress (cN/dtex). By setting the heat shrinkage stress (H) of the highly heat-shrinkable polyamide fiber to such a range, the fiber having different shrinkage characteristics (Japanese: ひきつれ) shrinks during heat treatment with boiling water, steam or the like in the production of a combined filament yarn, and a bulkier combined filament yarn can be obtained. In addition, when the woven fabric is produced, the filaments are sufficiently shrunk with the fibers having different shrinkage characteristics when heat-treated with boiling water, steam, or the like, and a high-density woven fabric having a full and soft feeling can be obtained. When the heat shrinkage stress (H) is less than 0.20cN/dtex, the heat shrinkage stress (H) is insufficient even if heat treatment is performed in the production of the combined filament yarn, and a difference in filament length is unlikely to occur, and sufficient bulkiness cannot be obtained. The heat shrinkage stress (H) of the high heat-shrinkable polyamide fiber is preferably 0.25cN/dtex or more, more preferably 0.30cN/dtex or more. Further, if the heat shrinkage stress becomes too high, the force of shrinkage becomes too high when producing a woven fabric, and the eyes of the cross points of the woven fabric are excessively closed, so that the woven fabric is not resistant to friction, and feathers, hair balls, and the like are likely to be generated, and thus the quality of the woven fabric obtained tends to be lowered. Therefore, the upper limit of the heat shrinkage stress (H) of the high heat-shrinkable polyamide fiber is preferably 0.50 cN/dtex.

It is important that the high heat shrinkable polyamide fiber of the present invention exhibits shrinkage characteristics in the above-mentioned ranges of boiling water shrinkage (B) and heat shrinkage stress (H). That is, it is important to satisfy both the boiling water shrinkage rate (B) indicating dimensional change when heat treatment is performed with boiling water, steam, or the like and the heat shrinkage stress (H) indicating the force (power) of shrinkage. When the boiling water shrinkage ratio (B) and the heat shrinkage stress (H) are set to the above ranges, in the production of a combined filament yarn at least partially comprising a highly heat-shrinkable polyamide fiber, a difference in filament length between the fiber and the fiber having different shrinkage characteristics is caused by heat treatment with boiling water, steam or the like, and the combined filament yarn is further shrunk with the fiber having different shrinkage characteristics, whereby a bulkier combined filament yarn can be obtained. In addition, when the woven fabric is produced, the filaments are sufficiently shrunk with the fibers having different shrinkage characteristics by heat treatment with boiling water, steam, or the like, and a high-density woven fabric having a full and soft feeling can be obtained.

The total fineness of the high heat-shrinkable polyamide fiber of the present invention is preferably 5 to 80 dtex. In particular, from the viewpoint of strength and lightweight of the fabric when used as a base fabric for sportswear, down jacket, outerwear, and underwear, the fabric is more preferably 8 to 50dtex, and still more preferably 8 to 40 dtex. The fineness of the high heat-shrinkable polyamide fiber per filament is preferably 0.9 to 3.0 dtex. In particular, from the viewpoint of the strength and soft feeling of the fabric when used as a base fabric for sportswear, down jacket, outerwear and underwear, the fabric is more preferably 0.9 to 2.0dtex, and still more preferably 0.9 to 1.3 dtex. By setting the single-filament fineness within such a range, even in a sewn product or a high-density woven fabric using a combined filament yarn heat-treated with boiling water, steam or the like, a good soft feeling can be obtained at the time of wearing, and a comfortable wearing feeling can be achieved.

The high heat-shrinkable polyamide fiber of the present invention has a high elongation of 25 to 50% and a strength of 2.5cN/dtex or more, and is preferably used for clothing applications, as long as it is a high elongation that is generally used, from the viewpoint of high-grade processing.

The unevenness (U%) in the fineness of the high heat-shrinkable polyamide fiber of the present invention in the longitudinal direction is preferably 1.2% or less, more preferably 1.0% or less, from the viewpoint of the quality of the weft insertion (japanese: ヨコムラ) of the fabric when used as a woven fabric for clothing applications. More preferably 0.8% or less.

The cross-sectional shape of the high heat-shrinkable polyamide fiber of the present invention is not particularly limited, and may be formed into any shape according to the application, and is preferably circular, triangular, flat, Y-shaped, or star-shaped.

The method for producing the high heat shrinkable polyamide fiber of the present invention will be explained.

When the crystalline polyamide and the amorphous polyamide are mixed and melted, a melt-kneading method using a pressure melting pot, a single-screw extruder, or a twin-screw extruder is exemplified. The melt kneading method preferably includes a pressure melting method or an extrusion method. In order to form a compatibilized system from a crystalline polyamide and an amorphous polyamide and to obtain a high thermal shrinkage stress (H), a single-screw extruder is preferably used. If a pressure melting pot is used, the phases are not uniformly mixed, so that a sea-island phase separation structure is formed, and a high thermal shrinkage stress (H) is not obtained. In addition, when a twin-screw extruder is used, the crystalline polyamide excessively reacts with the amorphous polyamide, and a high strain zone formed in the amorphous portion of the crystalline polyamide is reduced, so that a high heat shrinkage stress (H) is not obtained. The mixed polymer of the crystalline polyamide and the amorphous polyamide flowing into the spin pack is discharged from a known spinneret. The melting temperature and the spinning temperature (so-called heat retention temperature around the polymer pipe and the spinning pack) are preferably from +20 ℃ to +60 ℃ of the melting point of the polyamide.

The process for producing the high heat-shrinkable polyamide fiber of the present invention can be produced by any of a method of continuously performing a spinning-drawing step (direct spinning-drawing method), a method of temporarily winding an undrawn yarn and then drawing the yarn (two-step method), a method of substantially omitting a drawing step at a high spinning speed of 3000m/min or more (high-speed spinning method), and the like, but is preferably a one-step method of the direct spinning-drawing method and the high-speed spinning method in terms of high productivity and production cost.

The production by the direct spinning-drawing method of melt spinning is exemplified.

The polyamide yarn discharged from the spinneret is cooled and solidified in the same manner as in ordinary melt spinning, drawn at 500 to 4000m/min by a first godet after oiling, stretched at 1.0 to 4.0 times between the first godet and a second godet, and wound into a package at 2000m/min or more, preferably 3000 to 4500 m/min.

At this time, by appropriately designing the ratio of the peripheral speeds (draw ratio) between the first godet roller and the second godet roller and the winding speed (winder speed), the desired strength and elongation of the polyamide yarn can be obtained.

Further, by performing hot drawing using the first godet roll as a heating roll, the fluidity of the polymer is improved, a high strain band is generated in the amorphous portion of the crystalline polyamide, and the thermal shrinkage stress (H) is improved. The thermal stretching temperature is preferably 130-160 ℃, and more preferably 140-160 ℃.

Further, by performing heat setting with the second godet roller as a heating roller, the heat shrinkage stress of the yarn can be appropriately designed. The heat setting temperature is preferably 130-180 ℃, and more preferably 150-170 ℃.

In addition, the winding may be performed by using a known winding device in the process up to the winding. The number of interlaces can also be increased by giving multiple interlaces if necessary.

Further, an oil agent may be added immediately before winding.

At least a part of the combined filament yarn of the present invention uses the high heat shrinkage polyamide fiber of the present invention. By mixing a high heat-shrinkable polyamide fiber with a fiber having different shrinkage characteristics, a difference in filament length occurs due to a difference in shrinkage characteristics when heat-treated with boiling water, steam or the like, and a bulky mixed filament yarn can be obtained. The fibers having different shrinkability are fibers having different boiling water shrinkability (B) when heat-treated with boiling water, steam or the like. The chemical fibers are not limited to chemical fibers and natural fibers, and examples of the chemical fibers include polyamide fibers typified by polycaprolactam and polyhexamethylene adipamide, polyester fibers typified by polyethylene terephthalate, and polyolefin fibers typified by polypropylene. For clothing applications, polyamide fibers and polyester fibers are preferred. More preferred are polyamide based fibers in sportswear, down coat, outerwear and underwear applications.

In addition, the difference in boiling water shrinkage (B) between the high heat-shrinkable polyamide fiber of the present invention and the fiber having different shrinkage characteristics is preferably 10 to 30% in terms of soft feeling and fullness. Further, the difference in boiling water shrinkage (B) is preferably 15 to 30%.

Further, it is preferable that the difference in the heat shrinkage stress (H) between the high heat-shrinkable polyamide fiber of the present invention and the fiber having different shrinkage characteristics is 0.10 to 0.40cN/dtex in terms of soft feeling and fullness. Further preferably, the difference in thermal shrinkage stress (H) is 0.15 to 0.30 cN/dtex.

The combined filament yarn of the present invention can be processed into a yarn by a known method. As the fiber mixing method, a spinning fiber mixture, an air fiber mixture, a cabling, a compound false twisting, and the like can be applied, and the air fiber mixture is easy to control the fiber mixture, and the production cost is low, which is preferable. Examples of the air-fiber mixing method include a warp-weft interlacing process, a taslon process, and a process using a rotating air flow.

At least a portion of the fabric of the present invention uses the high heat shrinkage polyamide fiber and/or the multifilament yarn of the present invention. By weaving and knitting the high heat-shrinkable polyamide fiber and the fiber having different shrinkage characteristics, the high heat-shrinkable polyamide fiber is sufficiently shrunk when heat-treated with boiling water, steam or the like, and the fiber having different shrinkage characteristics is shrunk, whereby a high-density fabric having a rich and soft feeling can be obtained.

The fabric of the present invention can be woven or knitted by a known method. Further, the weave of the fabric is not limited. In the case of woven fabrics, the weave may be any of plain weave, twill weave, satin weave, modified weaves thereof, and mixed weaves depending on the application used, but when woven fabrics having a strong and full texture are produced, plain weave having a large number of binding points, and tear-resistant weave combining plain weave with stone weave or basket weave are preferable. In the case of a knitted fabric, the texture may be any of plain texture, interlock texture, warp knitting texture (coated article in japanese: ハーフ), satin texture, jacquard texture, a modified texture thereof, and a mixed texture of circular knitted fabric depending on the application used, but a warp knitting texture such as single comb flat fabric is preferable in view of the thinness and stability of the knitted fabric and the excellent elongation.

The sewn product using the fabric of the present invention for a part is not limited to the use thereof, but is preferably used for clothing, and more preferably used for sports, casual clothing, and men's clothing such as down jackets, windproof coats, golf coats, and raincoats. Particularly, the fabric can be suitably used for sports wear and down wear.

Examples

The present invention will be specifically described below with reference to examples.

A. Melting Point

Thermal Analysis was performed using a Differential Scanning Calorimeter (DSC) TA Instrument co-product Q1000, and data processing was performed using a Universal Analysis 2000. Thermal analysis was performed under a nitrogen gas flow (50mL/min), at a temperature range of-50 to 300 ℃, a temperature rise rate of 10 ℃/min, and a sample weight of about 5g (thermal data was normalized by the measured weight). Melting points were determined from the melting peaks.

B. Relative viscosity

0.25g of a polyamide sample was dissolved in 25ml of 98 mass% sulfuric acid and the flow-down time at 25 ℃ was measured using an Ostwald viscometer (T1). Subsequently, the downflow time of sulfuric acid having a concentration of only 98 mass% was measured (T2). The ratio of T1 to T2, T1/T2, was set as the relative viscosity of sulfuric acid.

C. Total fineness, single fineness

The total fineness and the single fiber fineness were measured in accordance with JIS L1013. A fiber sample was subjected to drawing at a tension of 1/30(g) to prepare 200-turn skeins by using a length measuring machine having a frame circumference of 1.125 m. The fiber was dried at 105 ℃ for 60 minutes, transferred to a dryer, left to cool at 20 ℃ for 30 minutes under 55RH, and the weight per 10000m was calculated from the value obtained by measuring the weight of the skein, and the total fineness of the fiber was calculated with the official moisture regain of 4.5%. The measurement was performed 4 times, and the average value was defined as the total fineness. The total fineness was divided by the number of filaments to obtain a single-filament fineness.

D. Glass transition temperature (Tg)

Thermal Analysis was performed using a Differential Scanning Calorimeter (DSC) TA Instrument co-product Q1000, and data processing was performed using a Universal Analysis 2000. Thermal analysis was performed under a nitrogen gas flow (50mL/min), under conditions of a temperature range of-50 to 270 ℃, a temperature rise rate of 2 ℃/min, a temperature modulation cycle of 60 seconds, a temperature modulation amplitude of. + -. 1 ℃ and a sample weight of about 5g (thermal data was normalized by the measured weight). The glass transition temperature (Tg) is the endothermic peak temperature observed as a shift of the baseline in a stepwise manner.

E. Boiling Water shrinkage (B)

The length A was determined by applying an initial load of 1/30(g) fineness to a fiber sample in a 50cm loop, and then immersed in boiling water for 30 minutes in a non-applied state, followed by natural drying, and the length B was determined by applying an initial load of 1/30(g) fineness again, and the boiling water shrinkage ratio (B) was calculated from the following equation.

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

F. Thermal shrinkage stress (H), thermal shrinkage stress with time (H2)

The fiber filaments unwound from the wound package were connected to each other by using a KE-2 type thermal contraction stress measuring machine manufactured by カネボウエンジニアリング to prepare a coil having a circumference of 16cm, an initial load of 1/30g of the fineness of the filament was applied, the thermal stress at the time of temperature change from room temperature to 210 ℃ at a temperature rise rate of 100 ℃/min was measured, and the peak (maximum) of the obtained thermal stress curve was defined as the thermal contraction stress (H). Further, fiber filaments unwound from the wound package were connected to each other to form a coil having a circumference of 16cm, the coil was kept at 20 ℃ and a relative humidity of 65% for 24 hours in a no-load state, an initial load of 1/30g of the fineness of the filament was applied, a thermal stress was measured at a temperature increase rate of 100 ℃/min from room temperature to 210 ℃, and the peak of the obtained thermal stress curve was defined as an elapsed thermal shrinkage stress (H2).

G. Weight ratio of crystalline Polyamide to amorphous Polyamide

The repetition ratio of the crystalline polyamide to the amorphous polyamide was calculated by NMR measurement, and the mass number of the repeating unit of each polyamide was calculated by mass spectrometry to determine the weight ratio.

(a) NMR measurement

Using nuclear magnetic resonance spectroscopy (¹H-NMR) was measured using Tetramethylsilane (TMS) as an internal standard substance (0 ppm). The repetition ratio of the crystalline polyamide to the amorphous polyamide (a is the repetition number of the crystalline polyamide × 2+ the repetition number of the amorphous polyamide × 2, and B is the repetition number of the amorphous polyamide × 4) is determined from a peak area (a) of a signal derived from hydrogen at the α -position of the carboxyl group forming the amide bond (usually around 3 ppm) and a peak area (B) of a signal derived from an aromatic hydrocarbon (usually around 7 ppm).

(b) Mass spectrometric analysis

The mass number of the repeating unit was determined using matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS), time-of-flight mass spectrometry (TOF-MS), and time-of-flight matrix-assisted laser desorption ionization mass spectrometry (MALDI-TOF-MS).

(c) Weight ratio of

Weight ratio (%) of crystalline polyamide (a/2) × (mass number of crystalline polyamide)

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

H. Compatibility

Exposing the threadline to RuO₄And (4) performing coating for making the boundary between the filament and the embedding resin clear by steam. Then, embedded in resin, thin slices were made and stained with phosphotungstic acid (PTA) aqueous solution for 15 min. The object to be observed obtained in the above manner was observed on a thin section at a applied voltage of 100kV using a transmission electron microscope (H-7100, Hitachi Co., Ltd.). The fiber cross section was observed at 3000 times observation magnification. In TEM observation results, it was judged as incompatible when a phase separation structure of islands and islands having dispersed phases with a diameter of 10nm or more was observed (X; incompatible), and it was not observed that the phase separation structure of islands and islands having a diameter of 10nm or more was incompatibleThe sea-island phase separation structure of the dispersed phase was judged to be compatible.

I. Strength and elongation

The fiber sample was measured under the constant-speed elongation conditions shown in JIS L1013 (chemical fiber filament test method, 2010) using "TENSILON" (registered trademark) manufactured by オリエンテック K.K.K., UCT-100. The elongation is determined from the elongation at the point showing the maximum strength in the tensile strength-elongation curve. The strength is obtained by dividing the maximum strength by the fineness. The measurement was performed 10 times, and the average values were set as strength and elongation.

J. Uneven fineness (U%)

Fiber samples were measured using a USTER TESTER III manufactured by Zellweger Uster, to determine sample lengths: 250m, measuring the filament speed: the measurement range (12.5% HI) at 50m/min was measured 4 times by 1/2Inert, and the average value was defined as a U% value.

K. Evaluation of knitted Fabric

(a) Production of Nylon 6 yarn

Polycaprolactam (N6) having a relative viscosity of 2.70 was melt discharged from a spinneret having 60 die discharge holes at a spinning temperature of 275 ℃. After the melt-discharged, the yarn was cooled, oiled, entangled, drawn by a godet roller of 2560m/min, stretched to 1.7 times, and heat-set at 155 ℃ to obtain a nylon 6 yarn of 80dtex60 yarn at a take-up speed of 4000 m/min. The nylon 6 yarn obtained had a fineness of 78.8dtex, a strength of 4.0cN/dtex, an elongation of 59%, a boiling water shrinkage of 10%, and a heat shrinkage stress of 0.09 cN/dtex.

(b) Production of combined filament yarn

The nylon 6 yarn obtained in the above (a) and the polyamide yarn obtained in examples 1 to 7 and comparative examples 1 to 6 were interlaced with each other by a weft and warp interlacing machine under an interlacing pressure of 2.0kg/cm²The interlacing treatment of (3) was carried out to obtain a combined filament yarn of 113dtex or 122 dtex.

(c) Tubular knitted fabric production

The combined yarn sample obtained in the above (b) was adjusted by a circular knitting machine so that the stitch density became 50 to produce a tubular knitted fabric.

The resulting tubular knitted fabric was scoured at 80 ℃ for 20 minutes, then dyed at 100 ℃ for 30 minutes using Kayanol Yellow N5G 1% owf, acetic acid adjusted to pH4, then treated at 80 ℃ for 20 minutes Fix, and finally treated at 170 ℃ for 30 seconds to improve hand.

(d) Evaluation of knitted Fabric

The tubular knitted fabric obtained in the above (c) was subjected to a bulky feeling (fullness) of the touch of a skilled artisan (5) in the following 5 steps. The decimal point of the average of the scores of each technician is rounded one after the other, 5 points are regarded as excellent, 4 points are regarded as good, 3 points are regarded as delta, and 1-2 points are regarded as x (por).

And 5, dividing: excellence in

And 4, dividing: slightly superior

And 3, dividing: in general

And 2, dividing: a little bit worse

1 minute: difference (D)

L. evaluation of woven fabrics

(a) Manufacture of warp yarns

Polycaprolactam (N6) having a relative viscosity of 2.70 was melt discharged from a spinneret having 20 die discharge holes at a spinning temperature of 275 ℃. After the melt-out, the yarn was cooled, oiled, entangled, drawn by a godet roller of 2560m/min, stretched to 1.7 times, and heat-set at 155 ℃ to obtain a nylon 6 yarn of 22dtex20 yarn at a take-up speed of 4000 m/min.

(b) Production of woven fabrics

The nylon 6 yarn obtained in the above (a) was used for the warp yarn (warp density 90 yarns/2.54 cm), and the polyamide yarn obtained in examples and comparative examples was used for the weft yarn to weave plain woven fabrics (basis weight 40 g/cm)²)。

The woven fabric thus obtained was scoured at 80 ℃ for 20 minutes, then dyed at 100 ℃ for 30 minutes with Kayanol Yellow N5G 1% owf and acetic acid adjusted to pH4, then treated with Fix at 80 ℃ for 20 minutes, and finally heat-treated at 170 ℃ for 30 seconds to improve hand.

(c) Evaluation of woven fabrics

The woven fabric obtained in (b) was subjected to the following 5 steps for high-density feeling, soft feeling, and fullness by the tactile sensation of a skilled worker (5 persons). The decimal point of the average of the scores of each technician is rounded one after the other, 5 points are regarded as excellent, 4 points are regarded as good, 3 points are regarded as delta, and 1-2 points are regarded as x (por).

And 5, dividing: excellence in

And 4, dividing: slightly superior

And 3, dividing: in general

And 2, dividing: a little bit worse

1 minute: difference (D)

[ example 1]

Polycaprolactam (N6) (relative viscosity. eta.r: 2.62, melting point 222 ℃ C.) as a crystalline polyamide and an isophthalic acid/terephthalic acid copolymerization ratio 7/3 as a non-crystalline polyamide, namely an isophthalic acid (6I)/terephthalic acid (6T)/hexamethylenediamine polycondensate (relative viscosity. eta.r: 2.10) were melt-kneaded at 265 ℃ using a single-screw extruder at a weight ratio of crystalline polyamide/non-crystalline polyamide of 70/30, and melt-discharged using a spinneret having 26 discharge holes with round holes (spinning temperature: 265 ℃ C.). After the melt-discharged, the yarn was cooled, oiled, entangled, drawn by a 1 st godet (drawing temperature: 150 ℃ C.) at 1500m/min, drawn to 2.4 times, and heat-set at 165 ℃ to obtain a polyamide yarn of 33dtex26 yarn (relative viscosity. eta.r: 2.46, glass transition temperature (Tg): 91 ℃ C.) at a take-up speed of 3500 m/min.

[ example 2]

A polyamide yarn of 33dtex26 filaments (relative viscosity. eta.r: 2.54, glass transition temperature (Tg): 87 ℃) was obtained by spinning in the same manner as in example 1 except that the weight ratio of crystalline polyamide/amorphous polyamide was 85/15.

[ example 3]

A polyamide yarn of 33dtex26 filaments (relative viscosity. eta.r: 2.39, glass transition temperature (Tg): 92 ℃) was obtained by spinning in the same manner as in example 1 except that the weight ratio of crystalline polyamide/amorphous polyamide was 55/45.

[ example 4]

Spinning was carried out in the same manner as in example 1 except that polyhexamethylene adipamide (N66) (relative viscosity. eta.r: 2.80, melting point 263 ℃ C.) was used as the crystalline polyamide and the spinning temperature was changed to 285 ℃ to obtain a polyamide yarn of 33dtex26 filaments (relative viscosity. eta.r: 2.59, glass transition temperature (Tg): 92 ℃ C.).

[ example 5]

Spinning was carried out in the same manner as in example 1 except that polyhexamethylene sebacamide (N610) (relative viscosity. eta.r: 2.80, melting point 219 ℃ C.) was used as the crystalline polyamide to obtain a polyamide yarn of 33dtex26 filaments (relative viscosity. eta.r: 2.59, glass transition temperature (Tg): 93 ℃ C.).

[ example 6]

Spinning was carried out in the same manner as in example 1 except that the draw ratio was changed to 2.8 times, thereby obtaining a polyamide yarn of 33dtex26 filaments (relative viscosity. eta.r: 2.59, glass transition temperature (Tg): 92 ℃).

[ example 7]

Spinning was carried out in the same manner as in example 1 except that the weight ratio of the crystalline polyamide/the amorphous polyamide was 85/15 and the discharge amount was changed to obtain a polyamide yarn of 54dtex26 filaments (relative viscosity. eta.r: 2.54, glass transition temperature (Tg): 85 ℃).

Comparative example 1

A polyamide yarn of 33dtex26 filaments (relative viscosity. eta.r: 2.59, glass transition temperature (Tg): 22 ℃) was obtained by spinning in the same manner as in example 1 except that the weight ratio of crystalline polyamide/amorphous polyamide was 95/5.

Comparative example 2

Spinning was carried out in the same manner as in example 1 except that the weight ratio of the crystalline polyamide/the amorphous polyamide was 30/70, thereby obtaining a polyamide yarn of 33dtex26 filaments (relative viscosity. eta.r: 2.26, glass transition temperature (Tg): 23 ℃).

Comparative example 3

Spinning was carried out in the same manner as in example 1 except that melt-kneading was carried out using a twin-screw extruder and the 1 st godet was not heated (drawing temperature: room temperature), thereby obtaining a polyamide yarn of 33dtex26 filaments (relative viscosity. eta.r: 2.96, glass transition temperature (Tg): 102 ℃).

Comparative example 4

Spinning was carried out in the same manner as in example 1 except that melt-kneading was carried out using a twin-screw extruder and the drawing temperature of the 1 st godet was 90 ℃ to obtain a polyamide yarn of 33dtex26 filaments (relative viscosity. eta.r: 2.96, glass transition temperature (Tg): 102 ℃).

Comparative example 5

A polyamide yarn of 33dtex26 filaments (relative viscosity. eta.r: 2.66, glass transition temperature (Tg): 29 ℃) was obtained by spinning in the same manner as in example 1 except that a copolymer of polycaprolactam and hexamethylene adipamide (N6/N66 copolymer) (relative viscosity. eta.r: 2.69, melting point: 198 ℃) having a copolymerization ratio of polycaprolactam and hexamethylene adipamide of 85/15 was used as the crystalline polyamide and the drawing temperature of the 1 st godet was set to 120 ℃.

Comparative example 6

Spinning was carried out in the same manner as in example 1 except that polycaprolactam (N6) (relative viscosity. eta.r: 2.62, melting point: 222 ℃ C.) and nylon MXD6 (Mitsubishi ガス chemical, relative viscosity. eta.r: 2.70, melting point: 237 ℃ C.) were used as the crystalline polyamide, the weight ratio of polycaprolactam to nylon MXD6 was 50/50, and the drawing temperature of the 1 st godet was 85 ℃ C. to obtain a polyamide yarn of 33dtex26 filaments (relative viscosity. eta.r: 2.66, glass transition temperature (Tg): 32 ℃ C.).

The polymer composition, yarn formability (compatibility) and drawing conditions of the polyamide yarn are shown in Table 1. The results of the yarn characteristics, the knitted fabric evaluation and the woven fabric evaluation of the obtained polyamide yarn are shown in table 2.

[ Table 1]

[ Table 2]

As is clear from the results in table 2, the woven fabric using the polyamide yarns of examples 1 to 7 of the present invention in a part (weft) undergoes the heat treatment process, and therefore, the excellent shrinkage is exhibited by the synergistic effect of the effect of shrinkage of the weft due to the difference in shrinkage between the warp and the weft and the effect of shrinkage of the weft with the warp, and a high-density woven fabric having a soft and full feel suitable for clothing can be obtained.

As is clear from the results in table 1, the combined filament yarn partially using the polyamide yarn of examples 1 to 7 of the present invention undergoes the heat treatment process, and exhibits excellent shrinkage due to the synergistic effect of the effect of shrinkage of the core yarn caused by the shrinkage difference between the core yarn and the sheath yarn and the effect of shrinkage of the core yarn with the sheath yarn, and thus a bulky combined filament yarn can be obtained.

In comparative example 1, since the weight ratio of the amorphous polyamide was small, the combined yarn was low in both the thermal shrinkage stress (H) and the boiling water shrinkage (B), and was poor in bulkiness. In addition, a sufficiently high-density feeling is not obtained, and a woven fabric having a rich feeling and a soft feeling is poor.

In comparative example 2, since the amorphous polyamide was present in a large amount by weight, the drawability was poor, and the yarn could not be stably produced. Further, the combined yarn has a low heat shrinkage stress (H) and is poor in bulkiness. In addition, a woven fabric having a sufficient density and poor fullness and softness is not obtained.

In comparative examples 3 and 4, the glass transition temperature (Tg) exceeded 95 ℃, the amorphous polyamide reacted excessively with the crystalline polyamide, and the thermal shrinkage stress (H2) decreased with time if the polyamide fiber was stored in a state in which no tension was applied, and thus the resultant filament blend was poor in bulkiness. In addition, a woven fabric having a sufficient density and poor fullness and softness is not obtained.

In comparative example 5, since the compatibility of the crystalline polyamide with the amorphous polyamide is poor and the glass transition temperature (Tg) is around room temperature, the shrinkage stress decreases with time when the polyamide fiber is stored in a state where no tension is applied thereto with time, and therefore a high thermal shrinkage stress with time (H2) is not obtained and the resulting filament blend has a poor bulkiness. In addition, a sufficiently high-density feeling is not obtained, and a woven fabric having a rich feeling and a soft feeling is poor.

In comparative example 6, since the polyamide filament yarn was composed of 2 kinds of crystalline polyamides and the glass transition temperature (Tg) was around room temperature, the thermal shrinkage stress (H2) decreased with time when the polyamide fiber was stored in a state in which no tension was applied with time, and thus a high thermal shrinkage stress (H) could not be obtained, and the resultant multifilament yarn had poor bulkiness. In addition, a sufficiently high-density feeling is not obtained, and a woven fabric having a rich feeling and a soft feeling is poor.

Claims

1. A high heat-shrinkable polyamide fiber characterized in that the glass transition temperature Tg is 85 to 95 ℃, the boiling water shrinkage B is 25 to 50%, the heat shrinkage stress H is 0.20cN/dtex or more,

the polyamide is formed by using crystalline polyamide and amorphous polyamide, and the weight ratio of the crystalline polyamide to the amorphous polyamide is 90/10-50/50.

2. The high heat-shrinkable polyamide fiber according to claim 1, wherein the total fineness is 5 to 80dtex, and the fineness of the single fiber is 0.9 to 3.0 dtex.

3. A combined filament yarn characterized by using the highly heat-shrinkable polyamide fiber according to claim 1 or 2 as at least a part of the combined filament yarn.

4. A fabric characterized by using the high heat shrinkable polyamide fiber according to claim 1 or 2 and/or the combined filament yarn according to claim 3 for at least a part of the fabric.