US20240309560A1 - Polyamide-46 multifilament and sewing thread for airbag - Google Patents

Polyamide-46 multifilament and sewing thread for airbag Download PDF

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Publication number
US20240309560A1
US20240309560A1 US18/681,223 US202218681223A US2024309560A1 US 20240309560 A1 US20240309560 A1 US 20240309560A1 US 202218681223 A US202218681223 A US 202218681223A US 2024309560 A1 US2024309560 A1 US 2024309560A1
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polyamide
multifilament
elongation
dtex
temperature
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Kazushi Minai
Hisao Shigeno
Akimi NAGASE
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Toray Industries Inc
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Toray Industries Inc
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Assigned to TORAY INDUSTRIES, INC. reassignment TORAY INDUSTRIES, INC. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: Minai, Kazushi, NAGASE, Akimi, Shigeno, Hisao
Publication of US20240309560A1 publication Critical patent/US20240309560A1/en
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    • D—TEXTILES; PAPER
    • D02—YARNS; MECHANICAL FINISHING OF YARNS OR ROPES; WARPING OR BEAMING
    • D02G—CRIMPING OR CURLING FIBRES, FILAMENTS, THREADS, OR YARNS; YARNS OR THREADS
    • D02G3/00—Yarns or threads, e.g. fancy yarns; Processes or apparatus for the production thereof, not otherwise provided for
    • D02G3/44—Yarns or threads characterised by the purpose for which they are designed
    • D02G3/46—Sewing-cottons or the like
    • D—TEXTILES; PAPER
    • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
    • D01F—CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
    • D01F6/00—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof
    • D01F6/58—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from homopolycondensation products
    • D01F6/60—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from homopolycondensation products from polyamides
    • D—TEXTILES; PAPER
    • D10—INDEXING SCHEME ASSOCIATED WITH SUBLASSES OF SECTION D, RELATING TO TEXTILES
    • D10B—INDEXING SCHEME ASSOCIATED WITH SUBLASSES OF SECTION D, RELATING TO TEXTILES
    • D10B2331/00—Fibres made from polymers obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds, e.g. polycondensation products
    • D10B2331/02—Fibres made from polymers obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds, e.g. polycondensation products polyamides
    • D—TEXTILES; PAPER
    • D10—INDEXING SCHEME ASSOCIATED WITH SUBLASSES OF SECTION D, RELATING TO TEXTILES
    • D10B—INDEXING SCHEME ASSOCIATED WITH SUBLASSES OF SECTION D, RELATING TO TEXTILES
    • D10B2401/00—Physical properties
    • D10B2401/06—Load-responsive characteristics
    • D10B2401/061—Load-responsive characteristics elastic
    • D—TEXTILES; PAPER
    • D10—INDEXING SCHEME ASSOCIATED WITH SUBLASSES OF SECTION D, RELATING TO TEXTILES
    • D10B—INDEXING SCHEME ASSOCIATED WITH SUBLASSES OF SECTION D, RELATING TO TEXTILES
    • D10B2401/00—Physical properties
    • D10B2401/06—Load-responsive characteristics
    • D10B2401/063—Load-responsive characteristics high strength
    • D—TEXTILES; PAPER
    • D10—INDEXING SCHEME ASSOCIATED WITH SUBLASSES OF SECTION D, RELATING TO TEXTILES
    • D10B—INDEXING SCHEME ASSOCIATED WITH SUBLASSES OF SECTION D, RELATING TO TEXTILES
    • D10B2505/00—Industrial
    • D10B2505/12—Vehicles
    • D10B2505/124—Air bags

Definitions

  • the present invention relates to a polyamide-46 multifilament and a sewing thread for airbag.
  • Multifilaments of polyamide 6 also referred to as “polycaprolactam” and polyamide 66 (also referred to as “polyhexamethylene adipamide”) have higher strength and elongation and superior fluff quality as compared with general-purpose multifilaments of polyester, polypropylene, or the like, and are therefore used in a wide variety of applications such as airbags, tire cords, sewing threads, transmission belts, ropes, and fishing nets.
  • polyamide 66 has been used for many years in the field of sewing threads from the viewpoint of high mechanical properties and heat resistance thereof.
  • polyamide 46 In contrast to polyamide 66, polyamide 46 has a higher melting point and higher heat resistance, and therefore is excellent in dimensional stability in high temperature, and therefore is a material particularly suitable for a sewing thread for airbags, and a technique for improving strength by improving spinning and drawing conditions is disclosed (Patent Document 1).
  • Patent Documents 2 and 3 a technique for improving dimensional stability in high temperature (Patent Documents 2 and 3) has also been disclosed, and an invention for further improving the characteristics of polyamide 46 has been reported so far.
  • a method for imparting stretchability to a general-purpose polyamide multifilament for example, a method is disclosed in which a polyamide multifilament of a partially drawing yarn is used as a sheath yarn, and is subjected to a taslan process with the polyamide multifilament of a core yarn (Patent Document 4).
  • Patent Document 4 a conventional stretchability developing technique is an original yarn design that impairs strength, and is difficult to apply to industrial applications requiring high strength.
  • the increase in temperature of the gas causes an increase in thermal damage to the airbag base fabric, and also causes a loss in mechanical properties of the sewing thread, particularly tends to stretch under a high-temperature atmosphere, and thus increases gas leakage due to an opening of the sewing portion.
  • the increase in gas output tends to increase the pressure due to the gas at the time of deploying the airbag, leading to an increase in gas leakage from the base fabric of the airbag, particularly from the sewing portion, causing such a problem that the performance as the airbag cannot be satisfied.
  • Patent Documents 5 and 6 various kinds of sewing thread for airbags have been proposed.
  • Patent Document 5 a sewing thread for airbags containing 50% or more of a fiber material having a melting point of 300° C. or more is examined, and an extremely high retention ratio of heat resistance is clearly shown.
  • the high-temperature dimensional stability is not specified, and the stretchability of the sewing thread is not studied.
  • Patent Document 6 shows that setting the elongation for the sewing thread and the elongation for the base fabric within specific ranges improves the followability of the sewing thread to the inflatable base fabric when the airbag is deployed, and the air permeability of the sewing portion is suppressed, but the stretchability of the sewing thread is not considered. Furthermore, the high-temperature dimensional stability of the sewing thread when the airbag is deployed has not been studied.
  • An object of the present invention is to provide a polyamide-46 multifilament having high strength, high-temperature dimensional stability, and excellent stretchability and suitable for the sewing thread for airbags having mechanical properties capable of suppressing air leakage from an airbag sewing portion due to a high-temperature and high-output gas as described above.
  • the present invention has been intensively studied to solve the above problems, and mainly has the following configurations.
  • a polyamide-46 multifilament having the following physical properties.
  • a sewing thread for airbags including the polyamide-46 multifilament according to any one of the above (1) to (4) .
  • Using the polyamide-46 multifilament of the present invention for sewing an airbag can suppress air leakage from an airbag sewing portion due to a high temperature and a high output gas during deployment of the airbag.
  • FIG. 1 is a schematic view of one embodiment of a step of producing the polyamide-46 multifilament (melting step is omitted).
  • the polyamide-46 multifilament of the present invention is made of a polyamide resin.
  • the polyamide resin is a polyamide resin containing polyamide 46 as a main component.
  • the polyamide 46 having a high melting point contained as a main component can provide a multifilament having high heat resistance.
  • polyamide resin the 98% by mass or more of which among the total mass of the polyamide resin excluding additives described later is made of polyamide 46, and it is more preferable that the polyamide resin includes only polyamide 46.
  • the polyamide resin may be a copolymerized polyamide obtained by copolymerizing polyamide 46 with another polyamide, and polyamide 6, polyamide 66, polyamide 610, or polyamide 612 may be used as another polyamide to be copolymerized.
  • the polyamide resin may be a mixture of polyamide 46 and another polyamide.
  • the sulfuric acid relative viscosity of the polyamide resin is preferably 3.3-5.0, more preferably 3.5-4.5.
  • the polyamide resin having a sulfuric acid relative viscosity exceeding 5.0 contributes to deterioration of stringiness, and frequently induces yarn breakage and fluffing during drawing process.
  • the polyamide resin having a sulfuric acid relative viscosity of less than 3.3 is difficult to provide the polyamide-46 multifilament having a predetermined sulfuric acid relative viscosity nr to be described later.
  • the sulfuric acid relative viscosity refers to a value measured by a method described in the section of Examples described later.
  • the polyamide resin in the present invention may contain additives such as an end-capping agent including monocarboxylic acid, a matting agent including titanium oxide, a polymerization catalyst or heat stabilizer including a phosphorus compound, and an antioxidant or heat stabilizer including a copper compound and a halide of an alkali metal or an alkaline earth metal as components other than polyamide, as necessary.
  • additives such as an end-capping agent including monocarboxylic acid, a matting agent including titanium oxide, a polymerization catalyst or heat stabilizer including a phosphorus compound, and an antioxidant or heat stabilizer including a copper compound and a halide of an alkali metal or an alkaline earth metal as components other than polyamide, as necessary.
  • the content ratio of the additive contained in the polyamide resin is preferably less than 5% by weight, and more preferably less than 3% by weight. If the content ratio of the additive is 5% by weight or more, the strength of the multifilament is reduced.
  • the heat stabilizer having a function of suppressing thermal degradation of the polymer is contained in an amount of preferably 250-7000 ppm, more preferably 500-5000 ppm.
  • the heat stabilizer may be used singly or in combination of two or more. If the content of the heat stabilizer is less than 250 ppm, the suppression of thermal degradation of the polymer is limited, and the stretch characteristics and dimensional stability after aging at a high temperature tend to be slightly impaired. On the other hand, adding the heat stabilizer in an amount of more than 7000 ppm decreases the strength and elongation of the fiber.
  • the sulfuric acid relative viscosity nr of the polyamide-46 multifilament of the present invention is preferably 3.0 ⁇ r ⁇ 4.5, more preferably 3.3 ⁇ r ⁇ 4.2, and still more preferably 3.5 ⁇ r ⁇ 4.0. Setting the sulfuric acid relative viscosity nr within such a range can produce the polyamide-46 multifilament having sufficient crystal orientation with good yarn productivity.
  • the total fineness of the polyamide-46 multifilament of the present invention is preferably 300-2300 dtex, and more preferably 400-1700 dtex. Setting the total fineness to 300 dtex or more cab suppress the generation of fuzz during thermal drawing. Furthermore, the melting time of the polymer is not excessively prolonged, and thus thermal decomposition of the polymer can be suppressed. In addition, setting the total fineness to 2300 dtex or less can provide the polyamide-46 multifilament excellent in mechanical properties without impairing uniformity of cooling after melt-spinning.
  • the number of single fibers of the polyamide-46 multifilament of the present invention is preferably 30-350, more preferably 50-250. If the number of the single fiber is less than 30, the single filament fineness is increased, the cooling efficiency during melt spinning is lowered, and the flexibility of the multifilament is lost. In addition, if the number of the single fiber is more than 350, the single filament fineness becomes thin, and fuzz is easily generated.
  • cross-sectional shape of the single fiber is not particularly limited.
  • cross sections having various shapes such as a flat shape, a polygonal shape, different shapes including a Y shape and an X shape, and a hollow shape can be adopted. Fibers having a plurality of cross-sectional shapes may be mixed.
  • the strength of the polyamide-46 multifilament of the present invention is 6.0-9.0 cN/dtex, more preferably 7.0-9.0 cN/dtex. It has been found that the strength range is an essential range for obtaining the polyamide-46 multifilament having stretchability due to the crystal orientation of polyamide 46, and is an essential characteristic for a polyamide multifilament for a sewing thread for airbags. If the strength is less than 6.0 cN/dtex, not only the durability as a sewing thread for airbags is insufficient, but also the crystal orientation is lowered, thus failing to provide the polyamide-46 multifilament having stretchability. If the polyamide-46 multifilament having a strength of more than 9.0 cN/dtex is to be obtained, mechanical drawing at a high ratio is required, failing to provide a sufficient elongation as a sewing thread for airbags.
  • the elongation (breaking elongation) of the polyamide-46 multifilament of the present invention is 15-30%, and more preferably 18-28%. If the elongation is in such a range, a polyamide multifilament suitable for a sewing thread for airbags is obtained. Furthermore, it has been found that due to the amorphous orientation of polyamide 46, the range of the elongation amorphous is essential for obtaining the high-temperature dimensional stability. If the elongation is less than 15%, impact absorption due to expansion and contraction becomes insufficient when a load is applied to the airbag sewing portion, and durability as a sewing thread cannot be maintained.
  • the orientation of the amorphous portion becomes excessively large, failing to provide the polyamide-46 multifilament having the high-temperature dimensional stability. If the polyamide-46 multifilament having an elongation of more than 30% is to be obtained, sufficient strength as a sewing thread for airbags fails to be obtained.
  • the polyamide-46 multifilament of the present invention has less than 1.0% of a degree of elongation after stretching 10 times under an environment at 100° C., E10 (100° C.), more preferably less than 0.8%. Within such a range, returning after expansion by the pressure at the time of deploying the airbag is good, the followability of the sewing thread to the inflatable base fabric is good, and the internal pressure retention performance is improved. If E10 (100° C.) is 1.0% or more, reduction of air leakage from the sewing portion is insufficient.
  • the difference between the elongation under a load of 2.0 cN/dtex at ordinary temperature, M (R.T.), and the elongation under a load of 2.0 cN/dtex at 100° C., M (100° C.), (M (100° C.) ⁇ M (R.T.)) is less than 0.5%, more preferably less than 0.3%, and still more preferably less than 0.1%.
  • M (100° C.) ⁇ M (R.T.) is less than 0.5%, more preferably less than 0.3%, and still more preferably less than 0.1%.
  • the difference between the degree of elongation after stretching 10 times at ordinary temperature, E10 (R.T.) and the degree of elongation after heat treatment at 120° C. for 24 hours when the fiber is subjected to 10 times of tensile tests at ordinary temperature, E10′ (R.T.), (E10′ (R.T.) ⁇ E10 (R.T.)) is preferably 0% or less. Within such a range, it is possible to suppress the stretch characteristic loss due to the aging in the sewing thread, the process of sewing, and the airbag storage environment.
  • the difference (M′ (R.T.) ⁇ M (R.T.)) between the elongation M (R.T.) under a load of 2.0 cN/dtex at ordinary temperature and the elongation M′ (R.T.) under a load of 2.0 cN/dtex at ordinary temperature after heat treatment at 120° C. for 24 hours is preferably 0% or less. Within such a range, it is possible to suppress deterioration in dimensional stability due to the aging in the sewing thread, the process of sewing, and the airbag environment.
  • FIG. 1 schematically shows a machine for direct spinning and drawing preferably used in the present invention.
  • FIG. 1 schematically shows a machine for direct spinning and drawing preferably used in the present invention.
  • an embodiment of the method for producing a polyamide-46 multifilament of the present invention will be described with reference to FIG. 1 as an example.
  • the polyamide-46 multifilament of the present invention is preferably produced by melt spinning, and as described above, the sulfuric acid relative viscosity of the polyamide 46 chips used for melt spinning is preferably 3.3-5.0, more preferably 3.5-4.5. Within such a range, it is possible to stably obtain the polyamide-46 multifilament having a high strength in a state where stringiness is good.
  • the moisture content of the polyamide 46 chips is preferably 1300 ppm or less, more preferably 800 ppm or less. Adjusting the chip moisture content to such a value can maintain the sulfuric acid relative viscosity of the polyamide-46 multifilament of the present invention within the range, and thus can achieve the strength level of the original thread required for the sewing thread for airbags. If the chip moisture content exceeds 1300 ppm, hydrolysis is promoted during polymer melting, and high strength cannot be obtained due to insufficient crystal orientation. In addition, the stretchability of the polyamide-46 multifilament is lost, failing to achieve the E10 (100° C.) as defined in the present invention.
  • the polyamide 46 has a property of decomposing at the time of melting to produce a low-molecular-weight product.
  • the decomposition mechanism can be roughly classified into thermal decomposition, oxidative decomposition, and hydrolysis, and melting under vacuum eliminates oxygen in water and air, and limits the decomposition mechanism only to thermal decomposition, and thus can suppress decomposition of the polymer. Suppressing decomposition during melting can maintain the high molecular weight of the polymer constituting the multifilament, and thus can produce a highly crystal-oriented polyamide-46 multifilament.
  • the spinning temperature is set to 10-50° C. higher than the melting point of the polymer chip, and melt spinning is performed from a spinneret 1 having discharge holes of preferably 30-350, more preferably 50-250.
  • a range of 5-300 cm from immediately below the spinneret 1 is surrounded by a heating hood 2 , and the melt-spun yarn is passed through a high temperature atmosphere of ⁇ 30 ⁇ +30° C. relative to the chip melting point.
  • the high-temperature atmosphere for passing is more preferably a melting point of ⁇ 30 ⁇ +15° C.
  • the undrawn yarn that has passed through the above step is cooled and solidified by blowing air at 10-80° C., preferably 10-50° C. by a cross flow cooling device 3 .
  • a cross flow cooling device 3 A case where the cooling air temperature that is less than 10° C. is not preferable because a large cooling device is required in this case. If the cooling air exceeds 80° C., an air volume is required, and single fiber swaying increases, and thus collision or the like between the single fibers occurs, which causes deterioration of yarn productivity.
  • the undrawn yarn that has been cooled and solidified is preferably subjected to multi-stage drawing, particularly two-stage or three-stage drawing. Specifically exemplifying the case of three-stage drawing in FIG. 1 , first, an oil agent is applied to the cooled and solidified undrawn yarn by an oil supply device 4 , and the undrawn yarn is taken up by a take-up roller (1FR) 6 .
  • the take-up roller is typically non-heated.
  • the yarn is wound in the order of a feeding roller (2FR) 7 , a first drawing rollers (1DR) 8 , a second drawing roller (2DR) 9 , a third drawing roller (3DR) 10 , and a relaxing roller (RR) 11 , subjected to heat treatment and drawing treatment, and wound around a winder 12 .
  • the surface of 2FR is preferably a mirror surface, and the surfaces of 1DR, 2DR, 3DR, and RR are preferably a satin surface.
  • the first-stage drawing is performed between 2FR and 1DR, and the temperature of 2FR (surface temperature of the roller) is 60-90° C. and the temperature of 1DR is 100-225° C.
  • the second-stage drawing is performed between 1DR and 2DR, and the temperature of 2DR (surface temperature of the roller) is 150-230° C.
  • the third-stage drawing is performed between 2DR and 3DR, and the temperature of 3DR (the surface temperature of the roller) is 180-240° C.
  • the draw ratio in the third-stage drawing step that is, the final drawing step is 1.00-1.10 times, and the draw ratio is more preferably 1.00-1.05 times.
  • the polyamide-46 polymer is known to have a significantly higher crystallization rate than conventional aliphatic polyamides such as polyamide 66 and polyamide 6. That is, it is easily expected that the crystallization of the fiber is sufficiently advanced after the first-stage drawing with a high draw ratio or after the second-stage drawing. There is no room for drawing the fiber again in such a final drawing step.
  • polyamide-46 multifilament of the present invention can be obtained.
  • the sewing thread for airbags using the polyamide-46 multifilament of the present invention can be produced by a known processing method.
  • Tensile strength and a degree of elongation measured by the method of JIS L1013 (1999) were defined as strength and elongation. Measurement was performed under conditions of a gauge length of 250 mm and a tensile speed of 300 mm/min using a Tensilon universal tester RTG-1250 with a high and low temperature tank manufactured by A & D Co., Ltd. The measurement was performed 5 times for each sample, and an average value thereof was obtained.
  • the measured value at ordinary temperature is represented as E10 (R.T.), the measured value under an environment of 100° C. as E10 (100° C.), and the measured value at ordinary temperature after the heat treatment as E10′ (R.T.), and the heat treatment was performed in an environment at 120° C. for 24 hours.
  • the measured value is an index indicating the stretchability of the multifilament, and as the E10 (100° C.) is smaller, the return after tension at a high temperature is better, indicating that the stretchability is excellent at a high temperature.
  • a value obtained by subtracting E10 (R.T.) from E10′ (R.T.) is an index indicating a change in stretchability after aging at a high temperature.
  • the measured value at ordinary temperature is represented as M (R.T.), the measured value under an environment of 100° C. as M (100° C.), and the measured value at ordinary temperature after the heat treatment as M′ (R.T.), and the heat treatment was performed in an environment at 120° C. for 24 hours.
  • a value obtained by subtracting M (R.T.) from M (100° C.) is an index indicating the high-temperature dimensional stability.
  • a value obtained by subtracting M (R. T.) from M′ (R.T.) is an index indicating a change in dimensional stability after aging at a high temperature.
  • A The yarn breakage in 1 hour is 0.1 times or more, and the number of fuzzes at 10, 000 m is 1 or more.
  • the production step shown in FIG. 1 was used.
  • a 5 wt % aqueous solution of copper acetate as a heat stabilizer was added to and mixed with a polyamide 46 chip (Stanyl (registered trademark), melting point 292° C.) having a sulfuric acid relative viscosity of 3.9, and 70 ppm as copper relative to the polymer weight was added and adsorbed.
  • a polyamide 46 chip Stanyl (registered trademark), melting point 292° C.) having a sulfuric acid relative viscosity of 3.9, and 70 ppm as copper relative to the polymer weight was added and adsorbed.
  • a 50 wt % aqueous solution of potassium iodide and a 20 wt % aqueous solution of potassium bromide were each added and adsorbed so as to be 1000 ppm as potassium relative to the polymer weight, and the chip moisture content was adjusted to 700 ppm by a known drying facility.
  • the polyamide 46 chips were melted at 305° C. under vacuum in an extruder spinning machine.
  • the molten polymer was weighed so as to have a total fineness of 940 dtex by a gear pump, filtered through a 20 u metal nonwoven fabric filter in a spinning pack, and spun from the spinneret 1 having 136 round holes.
  • the heating hood 2 having a heating hood length of 15 cm was placed 3 cm below the spinneret surface, and heated so that the in-cylinder atmospheric temperature was 300° C. and the spun yarn passed through the atmosphere at 300° C.
  • the in-cylinder atmosphere temperature is an air temperature at a portion 1 cm away from the inner wall at the center of the heating hood length.
  • the cross flow cooling device 3 for blowing air from one direction was attached immediately below the heating hood, and cold air at 20° C. was blown at a speed of 35 m/min to the yarn that had passed through the heating hood to cool and solidify the yarn, and then an oil solution was applied to the yarn with the oil supply device 4 .
  • An undrawn yarn to which the oil solution had been applied was wound and taken up in 1FR6 rotating at a surface speed of 600 m/min, and then drawn at a total draw ratio of 4.70.
  • the take-up yarn was continuously stretched by 5% between the take-up roller 6 and 2FR7 without being wound up once, and then successively drawn in the first stage at a rotation speed ratio of 3.27 times, then drawn in the second stage at a rotation speed ratio of 1.30 times, and finally drawn in the third stage at a rotation speed ratio of 1.05 times, and then wound up at a speed of 2600 m/min.
  • roller surfaces of 1FR and 2FR were mirror finished, and 1DR, 2DR, 3DR, and RR were satin finished.
  • the roller temperatures of 1FR were non-heated, 2FR was 80° C., 1DR was 175° C., 2DR was 180° C., 3DR was 230° C., and RR was 150° C.
  • Example 2 The procedures was performed in the same manner as in Example 1, except that a polyamide 66 polymer having a sulfuric acid relative viscosity of 3.8 was melt-spun at 280° C. under vacuum using an extruder spinning machine.
  • Example 2 The procedure was performed in the same manner as in Example 1, except that a polyamide 6 polymer having a sulfuric acid relative viscosity of 3.8 was melt-spun at 260° C. under vacuum using an extruder spinning machine.
  • the polyamide-46 multifilament of the present invention has high strength, high thermal dimensional stability, and excellent stretchability.
  • the conventional aliphatic polyamide multifilament shown in Comparative Examples 7 and 8 has high strength, but has low stretchability and insufficient high-temperature dimensional stability. When applied as the sewing thread for airbags, it is impossible to suppress misalignment and improve internal pressure retention performance.
  • Comparative Example 1 when the final draw ratio in the final drawing step is more than 1.10 in the production of the polyamide-46 multifilament having high strength, the amorphous orientation increases, thus resulting in the multifilament easily undergoing thermal shrinkage. Therefore, it was confirmed that the high-temperature dimensional stability M (100° C.) ⁇ M (R.T.) was more than 0.5. On the other hand, in Comparative Example 2, the final draw ratio in the final drawing step was less than 1.0, and thus yarn breakage frequently occurred, and raw yarn collection was difficult.
  • Examples 2 and 6 and Comparative Example 5 were examples in which the crystal structure of the polyamide-46 multifilament was controlled, but the crystal orientation was smaller as the draw ratio was shifted to low draw ratio, and the influence on the stretchability was confirmed. Similarly, in Examples 2 and 7 and Comparative Example 6, the amorphous orientation was increased as the draw ratio was shifted to high draw ratio, and the influence on the high-temperature dimensional stability was confirmed. In Comparative Example 6, the high draw ratio resulted in deterioration of the yarn productivity.
  • the polyamide-46 multifilament of the present invention has high strength and high heat resistance, and is suitable for sewing thread for the sewing thread for airbags. Furthermore, excellent high-temperature dimensional stability and stretchability induce a sewing portion filling effect in use of the sewing thread for airbags. It is possible to provide an airbag that achieves reduction of air leakage from a sewing portion due to a high-temperature and high-output inflator and improvement in internal pressure retention performance, which have been problems heretofore.

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PCT/JP2022/033826 WO2023038098A1 (ja) 2021-09-10 2022-09-09 ポリアミド４６マルチフィラメントおよびエアバッグ縫製糸

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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20050142969A1 (en) * 2003-12-30 2005-06-30 Hyosung Corporation Polyamide fiber for uncoated airbags
JP2009275294A (ja) * 2008-05-12 2009-11-26 Seiren Co Ltd エアバッグ用縫い糸およびそれを用いたエアバッグ
US20110036447A1 (en) * 2008-03-10 2011-02-17 Toray Industries, Inc. Base cloth for air bag, raw yarn for air bag, and method for producing the raw yarn
US20180340042A1 (en) * 2015-12-01 2018-11-29 Ascend Performance Materials Operations Llc High Molecular Weight Polyamides and CoPolyamides with Uniform RV and Low Gel Content

Family Cites Families (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5976914A (ja) * 1982-10-22 1984-05-02 Toray Ind Inc ポリアミド繊維およびその製造方法
JPS5988910A (ja) 1982-11-04 1984-05-23 Unitika Ltd 高強力ナイロン４６繊維及びその製造
JPH01168914A (ja) 1987-12-21 1989-07-04 Toray Ind Inc ポリテトラメチレンアジパミド系繊維
JPH0457912A (ja) * 1990-06-27 1992-02-25 Unitika Ltd ナイロン４６モノフイラメントの製造法
JPH05272009A (ja) * 1992-01-31 1993-10-19 Unitika Ltd エアーバツグ用ナイロン４６繊維およびシート
JPH0687394A (ja) * 1992-09-09 1994-03-29 Unitika Ltd エアーバツグ
JPH06235136A (ja) 1993-02-04 1994-08-23 Kuraray Co Ltd エアバッグ用縫い糸
JPH07216649A (ja) * 1994-01-21 1995-08-15 Unitika Ltd 高強度・高収縮性ポリアミド繊維とその製造法
KR100501470B1 (ko) * 1998-10-20 2005-09-26 주식회사 코오롱 폴리아미드 필라멘트사 및 그 제조방법
JP3566934B2 (ja) 2001-02-27 2004-09-15 カネボウ株式会社 ナイロンストレッチ糸とそれを使用したスパンライク織物
CN101313091A (zh) * 2005-10-19 2008-11-26 东丽株式会社 卷曲弹力丝及其制造方法、纤维结构体
TWI346156B (en) * 2007-11-23 2011-08-01 Shinkong Synthetic Fibers Corp Rectangular-like cross section of a polyamide fiber yarn for fabrics of uncoated airbags and the production process thereof
JP5093374B2 (ja) 2011-03-10 2012-12-12 東洋紡株式会社 エアバッグ
JP7275733B2 (ja) * 2019-03-26 2023-05-18 東レ株式会社 高強度ポリアミドモノフィラメント
WO2021182429A1 (ja) * 2020-03-13 2021-09-16 東レ株式会社 ポリアミド４６マルチフィラメント

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20050142969A1 (en) * 2003-12-30 2005-06-30 Hyosung Corporation Polyamide fiber for uncoated airbags
US20110036447A1 (en) * 2008-03-10 2011-02-17 Toray Industries, Inc. Base cloth for air bag, raw yarn for air bag, and method for producing the raw yarn
JP2009275294A (ja) * 2008-05-12 2009-11-26 Seiren Co Ltd エアバッグ用縫い糸およびそれを用いたエアバッグ
US20180340042A1 (en) * 2015-12-01 2018-11-29 Ascend Performance Materials Operations Llc High Molecular Weight Polyamides and CoPolyamides with Uniform RV and Low Gel Content

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
Espacenet translation of JP-2009275294-A. (Year: 2009) *

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