JP4603297B2 - Polyhexamethylene adipamide fiber - Google Patents

Description

  The present invention relates to a polyhexamethylene adipamide fiber for weaving a high-density bag weaving without using a paste and substantially without twisting. Furthermore, non-sizing weaving to obtain a fabric for high-density industrial materials that is excellent in high-speed weaving at the time of high-density bag weaving, excellent in quality after weaving, and excellent in adhesion and adhesion retention by elastomer application. The present invention relates to polyhexamethylene adipamide fiber.

In recent years, bag-like or hollow fabrics are formed by a weaving method called bag weaving or double weaving using a jacquard loom, and are used for industrial materials. For example, relatively complicated hollow fabrics are obtained by bag weaving in applications such as cloth forms for placing concrete in civil engineering materials and airbags that are occupant restraint safety devices for automobiles.
The bag-woven fabric is filled with a material depending on the application, such as concrete or gas, in the hollow shape, so that it is woven at a high density and a double (or multiple) fabric is formed on the loom. It is woven by passing through a place that is very deep with ridges and folds.

  In weaving with high density, the warp is more strongly squeezed.Therefore, not only the fiber's own fluff quality but also the fluff newly generated during the weaving process causes the weaving machine to cut warp and weft to run poorly. Will stop. In such a case, generation of fluff during weaving is generally prevented by applying a water-soluble paste to the fiber and weaving. However, in the method of weaving using such a paste, a step of removing the paste attached to the fibers by washing after weaving and a step of drying and heat-setting the washed fabric are essential. Non-sizing weaving technology that does not use a paste is known, but when we try to weave a high-density fabric with this technology, there is a lot of fluffing in the weaving process due to the high density, and weaving with a fluff There will be many stops. Even if weaving was possible, fluff was generated, and a high-density fabric in which fluff was woven was not preferable because the appearance quality was inferior and the mechanical strength could be lowered.

In high-density fabrics for industrial materials, particularly bag woven fabrics used for airbags, the structure is a complicated shape, and the bag fabric itself is a complex structure composed of a single part and a double part. The high-density part, particularly the single part, and the paste near the single part and double part boundary did not fall off sufficiently by washing, and there was a drawback that the washing process took time.
Furthermore, the finished high-density bag woven fabric is coated with an elastomer resin, for example, silicone, urethane, chloroprene resin, etc. in order to maintain air retention during deployment as required. Adhesion with these resins has been a problem. That is, when the coating resin solution is coated by a known method, if the coating resin is a bag-woven fabric with a lot of fluff, there is a problem that a large coating unevenness is caused and a partial coating amount is changed. Furthermore, it is required that the elastomer film after drying is firmly attached to the bag-woven fabric. However, in a high-density fabric woven and scoured (washed) using a paste, the elastomer permeability is lacking. There was also a problem that the adhesive strength between the film and the fabric was lowered.

In Patent Document 1, an industrial material woven fabric such as an airbag is obtained by using a single fiber entangled synthetic fiber for non-sizing weaving without using a glue and substantially non-twisting. It is disclosed that a thread having high entanglement strength in entanglement evaluation measured by piercing a thread into a thread is used as a fiber for the purpose. However, nothing is said about the high-speed weaving property of the bag weave, the quality of the fabric, and the elastomer application performance.
In Patent Document 2, as an unsized (non-sizing) yarn, the degree of entanglement (that is, opening length) measured from the unevenness of the fiber yarn by a contact displacement meter is good, and after selection with an online fluff sensor during yarn production A yarn having a long fluff appearance length (reciprocal of the number of fluff) and capable of non-sizing weaving is shown. However, nothing is disclosed regarding the high-speed weaving property of bag weaving, the degradation of weaving quality due to the new generation of fluff during weaving, and the performance of elastomer application, which are the objects of the present invention.

  Patent Document 3 discloses a entangled yarn as a fiber for weaving, and as the entangled yarn, a yarn having a good degree of entanglement measured from the outer shape of the fiber yarn by shape projection observation and little variation. This entangled yarn is capable of high-speed weaving. After weaving, the entanglement is eliminated, gas permeability can be reduced, and the coated surface becomes uniform. However, according to the study by the present inventors, practical high-speed weaving is difficult with this entangled yarn, and there is a problem of degradation of weaving quality due to new generation of fluff during weaving in bag weaving, Nothing is disclosed regarding the point of increasing the adhesive strength between the coating film and the fabric after the application of the elastomer, and nothing is mentioned about the conditions for obtaining a high-density bag-woven fabric with non-sizing fibers.

JP-A-8-31733 JP 2001-288638 A Special table 2003-521589 gazette

  The present invention provides a high-density bag woven fabric that is optimal for industrial material applications, particularly for airbag bag woven fabrics. In order to obtain a bag woven fabric that is excellent in the adhesiveness between the fabric after the elastomer coating and the elastomer film, and the condition can be examined, the occurrence of woven fluff can be suppressed, and the degradation of the quality of the living machine due to the fluff can be prevented. An object is to provide polyhexamethylene adipamide fiber.

In order to solve the above-mentioned problems, the present inventors diligently studied about the single yarn entanglement state of the fiber, and reached the present invention.
That is, the present invention
(1) Polyhexamethylene adipamide fiber for air bags satisfying the following physical properties.
(A) The number of entanglements is 30 to 45 / m
(B) 5-30% variation in the number of entanglements
(C) The confounding number remaining ratio after tension treatment of 1.0 cN / dtex at a speed of 100 m / min is 60 to 100%.
(D) Variation in cross-sectional area of single yarn on the cut surface of the fiber is 0.5 to 10%
( E ) Toughness of 180 to 350 cN · mm / dtex
(F) Fineness is 100 to 1000 dtex
(G) Single yarn fineness of 1 to 7 dtex
(2) The polyhexamethylene adipamide fiber according to (1), wherein the sum of the elongation at the intermediate strength and the boiling water shrinkage is 16.0 to 20.0%.
(3) A resin-coated airbag made of polyhexamethylene adipamide fiber that satisfies the following physical properties.
(A) The number of entanglements is 30 to 45 / m
(B) 5-30% variation in the number of entanglements
(C) The confounding number remaining ratio after tension treatment of 1.0 cN / dtex at a speed of 100 m / min is 60 to 100%.
(D) Variation in cross-sectional area of single yarn on the cut surface of the fiber is 0.5 to 10%
(E) Toughness of 180 to 350 cN · mm / dtex
(F) Fineness is 100 to 1000 dtex
(G) Single yarn fineness of 1 to 7 dtex
(4) When melt spinning polyhexamethylene adipamide, a polyhexamethylene adipamide resin having a relative viscosity of 50 to 100 is used, and the spinneret unit is kept warm by bringing a heat insulation heater into contact with the spinneret. While attached, filter at a spinneret back pressure of 30 kg / cm ² or more, stretch the spun yarn in multiple stages with a Nelson roll or separator roll, and install an interlacer with an orifice cross-sectional area / chamber cross-sectional area ratio of 0.25 to 0.50. Used, a fluid energy of 3.1 MPa · Nm ³ / Hr or more is applied, a single yarn is entangled with a yarn residence time of 25 msec or more, and then wound, and the fineness is 100 to 1000 dtex and the single yarn fineness is 1 Process for producing -7 dtex polyhexamethylene adipamide fiber.
It is.

  The synthetic fiber of the present invention is capable of non-sizing high-density bag fabric for industrial material use, is capable of high-speed weaving, and a high-quality and flexible bag fabric with suppressed weaving fluff is obtained. Furthermore, it has the effect that the coating film adhesion is strong when the elastomer coating film is formed on the woven fabric.

The present invention will be specifically described below.
The polyhexamethylene adipamide fiber of the present invention is a so-called long fiber, and is composed of a polyamide fiber, particularly, a polyhexamethylene adipamide fiber. The polyhexamethylene adipamide fiber of the present invention refers to a polyamide 66 fiber having a melting point composed of 100% hexamethylene diamine and adipic acid and having a melting point of 250 ° C. or higher. , Polyamide 6I, polyamide 610, polyamide 6T or the like may be copolymerized or blended. In addition to the polyhexamethylene adipamide fiber, other materials such as aromatic polyamide and polyester fiber may be mixed and used within the range where the physical properties do not deteriorate.

The fineness of the polyhexamethylene adipamide fiber of the present invention is preferably 100 to 1000 dtex, more preferably 120 to 500 dtex. If the fineness is within this range, a high-density bag woven fabric can be obtained without any problem.
The fineness of the constituent single yarn of the polyhexamethylene adipamide fiber in the present invention is preferably 1 to 7 dtex, more preferably 2 to 4.5 dtex. If the single yarn fineness is low, there is a high possibility that a flexible fabric will be obtained. However, in the case of a bag-woven fabric, if it is 2 to 4.5 dtex, an airbag excellent in flexibility and adhesiveness to the elastomer film can be obtained. When the single yarn fineness exceeds 7 dtex, the bag woven fabric becomes hard and a flexible woven fabric cannot be obtained. On the other hand, if the single yarn fineness is smaller than 1 dtex, the tensile mechanical properties such as single yarn toughness of the fiber bundle constituting the warp and weft are low, and fluff generation due to physical damage during high-speed weaving, that is, single yarn breakage occurs. Is difficult to suppress.

The polyhexamethylene adipamide fiber of the present invention has a tensile strength of 6.0 cN / dtex or more, more preferably 8.0 cN / dtex or more. At this time, the breaking elongation of the polyhexamethylene adipamide fiber is 15 to 30%.
In the present invention, the constituent single yarn fibers of the polyhexamethylene adipamide fiber are converged, so that the constituent single yarns are entangled with each other under specific conditions. In general, it is known that when an air stream is blown onto a fiber, single yarns are entangled with each other at the front and back portions thereof.

  When this is carried out with the running yarn, the entangled part and the non-entangled part, that is, the opening part are fibers in which they are alternately arranged in the yarn length direction. In the present invention, the number of entanglements is 30 / m or more and 45 / m or less for use in the weaving process. The number of entanglements here can be measured using an “ITEMAT LAB TSI” apparatus manufactured by Enka technica GmbH. The single yarn of polyhexamethylene adipamide fiber is less likely to be separated in the weaving preparation process, and can prevent the occurrence of fluff and prepare for the weaving process. The number of entanglements is usually the number of entanglements per meter, and the greater the number of entanglements, the shorter the distance between the entangled points, that is, the shorter the opening length, and the less the variation between the entangled points.

  In the present invention, the variation in the number of entanglements needs to be 5 to 30%. This is because the variation in the number of entanglements is 30% or less, and long openings that tend to become fluff due to ironing by the loom during weaving are reduced. It is possible to prevent the degradation of raw machinery quality due to weaving.

  The remaining number of entanglements can be measured by the following method. In other words, the number of entanglements is obtained by the ratio of the number of entanglements (1) with no load and the number of entanglements (2) with load, using an “ITEMAT LAB TSI” device manufactured by Enka technica GmbH. This device draws fibers at an evaluation speed of 100 m / min, and determines the entangled part by detecting the gap of the fibers under a certain pressure between two rolls installed so as to sandwich the drawn fiber yarn. . Since the single yarns run on each other at the entangled part of the fiber, the gap between the rolls is large, and at the non-entangled part, that is, the opening part, the single yarns are arranged in parallel and flat. The gap becomes smaller. By measuring the sample length of 20 m, the entangled portion, the non-entangled portion, and the variation in the fiber length direction of the entangled portion can be evaluated. In this apparatus, the strength of entanglement can be evaluated, and the evaluation is based on the measurement with no load and the number of entanglements with a tension of 1.0 cN / dtex applied.

  In the present invention, it is necessary that the entangling number remaining rate after the tension treatment of 1.0 cN / dtex is 60 to 100%. The confounding number remaining rate can be obtained by dividing the number of confounding (2) by the number of confounding (1) and multiplying by 100. Of course, in this measuring device, it is possible to change the load tension to some extent, but in the relationship between the strength of the entanglement necessary for the intended non-sizing weaving and the initial number of entanglements (2), It has been found for the first time that the correlation with the number of confounding at 1.0 cN / dtex is large. It is found that if the residual rate of entanglement after tension treatment of 1.0 cN / dtex is 60% or more, non-sizing weaving is possible, and entanglement clearly remains in the woven yarn after weaving. It was found that fluffing can be prevented during weaving.

  That is, if the remaining ratio of the entanglement number after the tension treatment of 1.0 cN / dtex is 60% or more, first, the convergence remains in the woven yarn after weaving the fabric, and the unevenness of the fabric surface increases. The single yarn in the woven fabric becomes coarse and dense. Next, since the single yarns of the woven yarn cross on the surface of the fabric, the single yarn on the surface of the woven yarn is broken in the uniformity in the direction of the woven yarn, and partially runs in a straight line. Due to the large and small irregularities on the surface of the fabric and the density of single yarn focusing inside the fabric, when forming the elastomer film, the penetration of the elastomer is promoted and the surface state is irregular, which improves the adhesion to the elastomer film. .

  It is necessary that the variation of the single yarn cross-sectional area in the polyhexamethylene adipamide fiber in the present invention is 0.5 to 10%. The cross-sectional area of the single yarn can be obtained by image analysis from the fiber cross-sectional photograph, and at the same time, the variation in cross-sectional area can be calculated. When the variation in cross-sectional area of single yarn exceeds 10%, single yarn thick and thin yarn will be mixed in the weaving yarn, especially thin single yarn with low breaking energy will be mixed, and fluff will be generated It is because it becomes easy to do. When producing polyhexamethylene adipamide fiber, since it is stretched all together as a fiber bundle, it is easy to cause variation in cross-sectional area in the stretching process, this variation is 0.5 to 10%, Combining with the point which makes an entangling number residual rate 60-100% can suppress the fluff generation | occurrence | production during weaving.

In the present invention, the toughness per fineness in the tensile test of the fiber needs to be 180 to 350 cN · mm / dtex. The present invention is for obtaining a high-density fabric for use in industrial materials, and preferably has higher mechanical properties. In particular, it is necessary to obtain a bag-woven fabric that is difficult to break as a fabric, that is, has a high breaking energy.
Further, the fluff generated during weaving is difficult to cut when the breaking energy of the weaving fiber is higher, so it is difficult to fluff, and in particular, it has a toughness of 180 to 350 cN · mm / dtex, so that fluff during high-density weaving Occurrence can be prevented.

  In the present invention, the sum of the elongation at the intermediate strength of the fiber and the boiling water shrinkage is preferably 16.0 to 20.0%. The elongation at the intermediate strength is referred to as so-called intermediate elongation, and corresponds to the elongation at constant load specified in JIS L1017. The sum of the values of the intermediate elongation and boiling water shrinkage is a measure of the dimensional stability of the fabric, and indicates the degree of dimensional change when heat treatment or the like is passed in the processing step as the physical property of the fiber. In the present invention, if the dimensional stability is 20.0% or less, the adhesiveness of the bag-woven fabric with the elastomer coating is good, and suitable processability is obtained. This is because even if the bag-woven fabric is subjected to a heat setting process after coating, the fabric has good dimensional stability, so that a fabric having a desired dimension can be obtained with little shrinkage of the fabric. If this sum is less than 16%, the strength of the bag-woven fabric may be insufficient, and if it exceeds 20%, the dimensional change may be large during heat treatment during coating, which is not preferable.

  The preferred intermediate elongation for the fiber here is 11 to 15%. The elongation at the intermediate strength Th [N] = 44 * F fineness / D reference fineness (940 dtex in the case of polyamide fiber) as defined in JIS L 1017, that is, the intermediate elongation is a uniaxially oriented polymer structure of the fiber. In particular, it reflects the orientation and relaxation and strain distribution of tie molecular chains. A fiber having a high degree of overall orientation of molecular chains, that is, a high intermediate elongation and a high apparent rigidity may have a large structural strain. In this case, the structural strain is relaxed by heat, the fiber contracts, and the intermediate elongation after heat treatment changes low. The smaller the change in the intermediate elongation during heat treatment, the better the dimensional stability and the size of the fabric crimp can be maintained.

  Further, the elongation at intermediate strength Th [N] = 44 * F fineness / D reference fineness (polyamide 940 dtex) represents the rigidity at high load. In terms of dimensional stability, both the intermediate elongation and boiling water shrinkage ratio should be small. However, when a high load is applied during operation as in an airbag application, the high elongation relative to the initial load means that the fabric follows deformation. It has good properties, and a hollow woven fabric is advantageous for preventing leakage of the filler. If the hollow fabric having a complicated shape has high fiber rigidity, stress is concentrated locally on a specific part of the boundary between the double part and the single part, and the leakage of the filler tends to occur. In order to suppress filling material leakage, the intermediate elongation is preferably 11% or more. In particular, the airtightness of the airbag is advantageous for improvement.

In order to set the intermediate elongation of the fiber to 11% or more, as the spinning condition, a polymer having a sufficient degree of polymerization may be used, and a spinning condition in which heat is relaxed subsequent to stretching together with sufficient and appropriate thermal multistage stretching may be selected.
The shrinkage rate of the polyhexamethylene adipamide fiber of the present invention depends on the shrinkage rate in boiling water (JIS L1017 8.14). A preferred boiling water shrinkage is 1 to 10%. A more preferable boiling water shrinkage is 5.0 to 9.0%, and most preferably 6.0 to 8.0%. If the heat shrinkage rate is low, the step stability during processing is good and the size of the fabric crimp can be maintained. Further, since the degree of shrinkage during processing is small, there is an advantage that a dimensional change during processing for obtaining a predetermined shape / dimension is small, and it is easy to design a required dimension finally.
The polyhexamethylene adipamide fiber of the present invention is preferably obtained by a usual direct spinning drawing method. Of course, it may be produced by a conventional undrawn yarn-combination method using a post-drawing method, but in order to produce a high strength yarn for industrial material use at a low production cost, production by a direct spinning drawing method is preferred.

In the present invention, the dried polyhexamethylene adipamide resin is melt-extruded using an ordinary extruder. As the polyhexamethylene adipamide resin, those having a relative viscosity of formic acid of 50 to 100 are suitable as a measure of molecular weight. More preferably, it is 60-90. The polyhexamethylene adipamide resin in this range is melt-spun and obtained by multi-stage stretching and low strain rate stretching (such as low speed stretching). The melted polyhexamethylene adipamide is usually produced by being discharged from a plurality of spinning holes from a single spinneret and taken out. In the present invention, the single yarn cross-sectional area variation of the obtained polyhexamethylene adipamide fiber is mainly caused by variations in the discharge amount of the spinning holes. In order to make the variation in the single yarn cross-sectional area of the present invention 0.5 to 30%, it is preferable that the back pressure is 30 kg / cm ² or more during filtration of the molten resin. More preferably, it is 50 kg / cm ² or more. The first cause of this back pressure is due to the pressure loss of the single spinning hole and the number of spinning holes due to the shape of the spinning hole. The spinneret back pressure may be measured by attaching a spinneret having a large spinning hole and observing the spinneret unit pressure difference from the normal spinneret. The second factor is clogging of spinning holes when the spinneret is attached. Normally, the spinneret unit is heated to a temperature higher than the spinning temperature and then attached to the spinning head. After being attached to the spinning head, heat transfer from the spinning head and the surrounding heater, radiation and polymer discharge are performed by the polymer itself. It is kept at a constant temperature by the amount of heat brought in. However, since the spinneret unit is exposed to the outside air and the temperature drops during the mounting operation, the polymer discharge is solidified from the adjacent spinning holes when it is partially cooled, and a part of the polymer flow path is formed. May solidify and block, and a predetermined discharge amount may not be obtained, resulting in variations in the discharge amount of the spinning holes in the spinneret surface and single yarn defects. Furthermore, once the polymer discharge from the spinning hole is delayed, the amount of heat supplied by the polymer itself is small, and the temperature has dropped to near the melting point just before the discharge. It is difficult to melt, and the discharge amount in the spinning hole generally does not recover. In particular, in spinning with a fine single yarn fineness as in the present invention, the spinning hole cross-sectional area is small, the amount of polymer discharged per spinning hole is small, and there is a dispersion in spinning hole discharge that occurs when the spinneret unit is attached. Likely to happen. Therefore, when attaching the spinneret unit, it is preferable to keep a spinneret surface warming heater in contact with the spinneret surface to prevent a decrease in the temperature of the spinneret surface. The spinneret surface warming heater can be removed when the polymer is discharged after the spinneret unit has been attached. In the present invention, the spinneret surface temperature is reliably maintained above the spinning temperature by the spinneret surface heat-retaining heater during the period until the polymer is discharged. Can be reduced, and the variation can be made 0.5 to 10%.

Stretching can be obtained by a normal Nelson roll or separator roll multistage stretching method. The roll speed can be selected depending on the production conditions from the normal first take-up roll of 500 to 2000 m / min to the final heat set roll of 2500 to 6000 m / min. The take-up roll may be used not only as a stretching roll but also as a heat setting roll.
Moreover, the surface roughness of the roll to be used may be either a mirror surface or a satin surface, and the surface roughness can be appropriately selected between 0.4 to 8S.
In the present invention, it is preferable to use an interlacer in multiple stages for imparting single yarn entanglement.
First, it is preferable to use a pre-interlacer before the take-up roll and provide a multi-stage interlacer between the final roll and the take-up machine (multi-stage is not shown in FIG. 1). In general, one interlacer is generally installed before the take-up machine. However, in the present invention, it is preferable to install two or three interlacers in series.
The interlacer used here is preferably, for example, PolyJet-SP25 series manufactured by Heberlein Fiber Technology Inc.

  Single yarn entanglement of the fibers occurs when the air jet flow in the interlacer collides with the fibers. The air jet used includes an interlacer through which the fiber passes and a yarn chamber and at least one air orifice that guides air or gas into the yarn chamber. A preferred air jet stream is preferably compressed air, and other possible gases include steam. Useful air jet streams are also commercially available. The number of air orifices in the interlacer is not limited, but a single orifice, double orifice or triple orifice air jet is preferred. The air jets can also be arranged in series in the interlacer. That is, there can be more than one air jet for each fiber yarn. The yarn chamber can have any cross-sectional shape through which the fiber passes, such as an oval, circular, square, half square, triangular, half moon or parallel plate. Moreover, the cross-sectional shape may change continuously. The angle at which the air flow is applied to the fiber yarn may be arbitrarily set, but is preferably a substantially right angle.

The ratio of the orifice cross-sectional area / chamber cross-sectional area in the interlacer used in the present invention is preferably 0.25 to 0.50.
In order to obtain the degree of entanglement of the present invention, sufficient air pressure is required at the same time. The compressed air pressure used for producing the fiber of the present invention is 0.2 to 1.5 MPa, preferably 0.4 to 1.0 MPa. Pressure in this range and the fineness of the polyhexamethylene adipamide fiber and The entanglement degree of the present invention can be obtained under the condition of single yarn fineness.

  In the present invention, an appropriate residence time of the fiber yarn in the air jet is required in order to obtain a entanglement with little variation in the number of entanglements and no variation. The yarn residence time in the air jet device is desirably 25 msec or more, more preferably 30 msec or more. The main governing factor of the effect of effectively imparting jet energy in the air jet is the length of the air jet yarn chamber, and the maximum factor to be controlled is the yarn traveling speed. Producing stable polyhexamethylene adipamide fiber with a yarn residence time of 25 msec or more and multiple stages, and a desired number of entanglements of 30 / m or more and a variation of the number of entanglements of 30% or less can do.

In order to produce the fibers of the present invention, the fluid energy determined by the air jet device conditions and air pressure in the interlacer must be sufficient. The fluid energy (MPa · Nm ³ / Hr) is obtained from the product of the air pressure (MPa) and the air consumption flow rate (Nm ³ / Hr). The fluid energy value is required to be 3.1 (MPa · Nm ³ / Hr) or more, preferably 3.5 (MPa · Nm ³ / Hr) or more, and more preferably 4.0 (MPa · Nm ³ / Hr). That's it. If the fluid energy value is 3.1 or more, the entanglement strength can be increased, and polyhexamethylene adipamide fibers suitable for non-sizing weaving of the present invention can be obtained.

As the spinning oil in the present invention, a normal emulsion type or straight type oil can be used. As the spinning oil, it is preferable to apply an emulsion type spinning oil in a small amount, preferably 0.3 to 1.5 wt%, particularly considering the adhesiveness to the elastomer.
In order to set the boiling water shrinkage of the polyhexamethylene adipamide fiber of the present invention to 10% or less, in the fiber yarn production process, the yarn tension is lowered after heat drawing, and the glass transition point of the drawn yarn is higher than the glass transition point. What is necessary is just to remove the structural distortion of an amorphous part on the thermal relaxation conditions made into temperature. For example, the yarn tension may be appropriately controlled by the speed difference between the rolls, and the yarn temperature may be appropriately controlled by the roll temperature or the chamber atmosphere temperature. It is also necessary to select an appropriate range for the degree of polymer polymerization. This is because, particularly, a high polymerization degree polymer tends to make it difficult to eliminate stretching strain, and it is preferable that the relative viscosity of formic acid does not exceed 110.
The stretched fiber is wound up with a winding weight of about 3 to 20 kg by a normal winder.

  The obtained polyhexamethylene adipamide fiber can be suitably used for non-sizing weaving applications. Non-sizing weaving is a method in which a warp is prepared and woven without substantial twisting without applying a paste to the fibers and without undergoing a twisting process. In this method, the material cost of the sizing agent becomes unnecessary, and the drying management after applying the sizing agent and the cleaning management for removing the sizing agent on the loom can be omitted, and the scouring process can be omitted or simplified depending on the application. There is also a method of securing single yarn convergence by applying WAX or the like in the paste applying step instead of applying the paste. Non-sizing weaving by WAX may improve the cleaning performance in the scouring process and simplify the process. However, sufficient single yarn convergence cannot be ensured by using only WAX. In the present invention, it is useful for any non-sizing weaving.

The polyhexamethylene adipamide fiber of the present application is an ordinary Rapier loom (such as Sulzer) having a Jacquard mechanism (made by Stoveli) or a dobby mechanism, an air jet loom (AJL), a water jet loom (WJL), etc. High-density weaving is possible in the bag weaving of this loom. A high-density bag woven fabric having a cover factor of 2000 or more is suitably used for airbag applications, and such a high-density fabric can be woven at a high speed of 300 rpm to 800 rpm.
Elastomer application is suitably used for the bag-woven fabric obtained by the present invention. Of course, in the case of an airbag that does not require airtightness, it can be used without coating. The amount of elastomer applied can be appropriately selected from 10 to 150 g / m ² . In particular, 80 g / m ² or less is preferable for airbag applications because it is lightweight.

The present invention will be described based on examples. In addition, the definition and measurement method of the physical properties used in the specification text and examples are as follows.
(1) Number of entanglements (1)
According to “ITEMAT LAB TSI” manufactured by ENKA technology GmbH. The evaluation speed was 100 m / min, the sample length was 20 m, and no load was evaluated.
(2) Number of entanglements (2)
According to “ITEMAT LAB TSI” manufactured by ENKA technology GmbH. The evaluation speed was 100 m / min, the sample length was 20 m, and evaluation was performed after a tension treatment of 1.0 cN / dtex.

(3) Entanglement number remaining rate after tension treatment of 1.0 cN / dtex Calculated from the following equation.
Entanglement number remaining rate (%) = {entanglement number (2) / entanglement number (1)} × 100
(4) Confounding number variation CV value (coefficient of variation):
Based on the evaluation of (2), the calculation was made from the following equation.
CV value (variation count) (%) = s / Χ × 100
Here, s: standard deviation of entanglement number variation, and Χ: mean number of entanglement values are shown, respectively, and the higher the CV value, the larger the variation.
(5) Fineness, strength, elongation, and toughness per fineness Measured according to JIS L 1073. The strength and elongation are values measured at a test length of 25 cm and a tensile speed of 30 cm / min. The toughness per fineness is a value obtained by dividing the integrated value of cutting energy in the tensile test by the fineness.

(6) Boiling water shrinkage The shrinkage in boiling water (JIS L1017 8.14) was determined.
(7) Warp fluff When preparing the warp from the yarn winding package, the fluff was observed by photoelectric detection and converted to the number of fluff per 10 ⁸ m.
(8) Stoppage at the time of weaving The frequency at which the machine was stopped at the time of weaving was determined due to a defect related to the convergence of warps.
(9) Biomechanical inspection Abnormal defects of weaving cloth were counted and converted per 100 m.

(10) Coated cloth inspection Abnormal defects (pieces) on the coated surface of the coated base cloth were counted and converted per 100 m.
(11) Formic acid relative viscosity (VR)
Using 90% formic acid, an 5.4 g solution in 49 ml was measured using an Ostwald viscosity tube at 25 ° C.
(12) Development pressure resistance of the coating bag: Air is sent from the storage tank to the coated bag weaving sample at once, air leaks due to coating film peeling are observed, and there is no air leak when there is a pressure holding of 95% or more after 5 seconds. It was. The maximum pressure without air leak was taken as the pressure resistance.
(13) Coin peel The coated surface of the single woven portion of the coated fabric is rubbed 5 mm at the jagged portion of the outer edge of a 100-yen coin. Those that were damaged but not peeled were judged as good (◯), and those that were peeled even at one place were judged as bad (x).

[Examples 1 to 4, Comparative Examples 1 to 6]
Using an extruder-type spinning machine, a polyhexamethylene adipamide chip having a relative viscosity of formic acid of 82 was melt-spun at 295 ° C. In each spinning, the base spun a yarn with a hole diameter of 0.3 mmφ, and the airbag yarn was produced by the direct spinning drawing process. The fineness and number of single yarns produced are shown in Table 1.
Stretching is performed by two-stage thermal stretching shown in FIG. 1, in which the spinning running yarn 1 is sequentially subjected to a finishing agent application nozzle 2, a take-up roll 3, a first stretching roll 4, a second stretching roll 5, a final roll 7, After sequentially passing through the racer 8, it was wound up by a winder 9.
The temperature of each roller was set to room temperature for the take-up roll 3, 210 ° C. for the first stretching roll 4, 230 ° C. for the second stretching roll 5, and 60 ° C. for the final roll 7.

The spinning speed is shown in Table 1. The draw ratio was such that the resulting fiber had a cutting strength of 8.5 cN / dtex, but the first draw ratio and the second draw ratio were set to 70% of the former.
As finishing agents, C18-26 unsaturated alcohol thiodipropionic acid ester 50 parts by weight, trimethylolpropane tri (C10-18 fatty acid) ester 10 parts by weight, C10-26 alkyl POEO polyether: 20 parts by weight, POE 20 parts by weight of hardened castor oil ether C10-18 fatty acid ester was dissolved in mineral oil at a concentration of 30% by weight, and 0.8% by weight of solid content was applied to the yarn.

The interlacing device interlacer 8 for interlacing the yarn was installed between the final roller and the winder, and the type of air jet and the high pressure air pressure were changed as shown in Tables 1 and 2, respectively. The number of entanglements, the uniformity of the number of entanglements, and the strength of the entanglement were evaluated. Further, warping was performed on the obtained entangled yarn at 500 m / min, and then weaved at a rotational speed of 300 rpm and 480 rpm with a Rapier loom (Sulzer G6200) and a Jacquard machine (Staubri, type CX960), and weft and warp The frequency of stopping due to the defects related to convergence was obtained. A bag weave having the shape shown in FIG. 2 was woven by the Jaquard weave. Furthermore, the defects were obtained by biomechanical inspection. The results are shown in Table 1 together with the density of the raw weaving. Next, the obtained base fabric was heat-set, and then 50 g / m ² of addition-type liquid silicone rubber was applied thereto to obtain a coated fabric. And the fault of this coat cloth was measured.

Moreover, the bag was cut out from the coated cloth and the developed pressure resistance was evaluated. The results are shown in Table 1.
In Examples 1 to 3, the number of entanglements is large, there is no variation in the number of entanglements, there is no variation in cross-sectional area of single yarn, and fluff does not increase in the bag weaving process, so that high-speed weaving is possible and weaving quality is also good. is there. Moreover, since the entanglement strength is high, the entanglement focusing is maintained in the woven fabric after weaving. With high-speed and high-pressure bag deployment, the coating film is excellent in airtightness without peeling damage. In Example 4, the number of entanglements is large, there is no variation in the number of entanglements, there is no variation in the cross-sectional area of the single yarn, and there is no increase in fluff during the bag weaving process, so that high-speed weaving is possible and weaving quality is good. Moreover, since the entanglement strength is high, the entanglement focusing is maintained in the woven fabric after weaving. Since the shrinkage of the fiber is large, the crimp of the woven fabric is small, and the pressure resistance evaluation due to the peeling damage of the coating film at the time of developing the bag at high speed and high pressure is slightly good. In Comparative Example 1, the number of entanglements is large, but the entanglement strength is insufficient, and the occurrence of fluff during weaving causes an increase in the number of stops, raw machine defects, and coated cloth defects. In Comparative Example 2, the entanglement strength is high, the entanglement number is small, and the entanglement number variation is large. Therefore, although the number of stops is small, the influence of fluff is large, and there are many defects of raw machinery and coat cloth. In Comparative Examples 3 and 4, since the entanglement strength is low, there are many increases in the number of stops, raw machine defects, and coated cloth defects. In Comparative Example 5, data Funes is low, greige disadvantage by fluff generation during weaving, often coated cloth drawbacks.

  As described above, the entangled yarn having a moderate number of entanglements and a uniform number of entanglements, entanglement strength of the present invention and a uniform cross-sectional area of the single yarn fiber, the generation of new fluff in the weaving process of the high-speed bag weave is suppressed, The number of stops caused by warps and wefts is small and the quality of raw machinery is good. In addition, a coated fabric excellent in the adhesiveness of the silicone coated film of the coated fabric and having good pressure and airtightness was obtained.

  The synthetic fiber of the present invention can be suitably used in the field of weaving bag fabrics used for industrial material applications, and furthermore, weaving bag fabrics with an elastomer coating attached. For example, it can be suitably used in the field of weaving a bag fabric used as a base fabric for an airbag of an automobile safety device.

It is the extending | stretching installation figure of this invention. It is a bag weave evaluation sample for deployment evaluation

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Spinning running yarn 2 Finishing agent provision nozzle 3 Take-up roll 4 1st extending | stretching roll 5 2nd extending | stretching roll 6 3rd extending | stretching roll
7 Final roll 8 Interlacer (Displayed as one set in Fig. 1)
9 Winding Machine 11 Bag Weaving Shape 12 Sample Cutting Line from Coated Base Fabric 13 Double Part 14 Single Part

Claims (4)

Polyhexamethylene adipamide fiber for bag- woven airbags that satisfies the following physical properties.
(A) The number of entanglements is 30 to 45 / m
(B) 5-30% variation in the number of entanglements
(C) The confounding number remaining ratio after tension treatment of 1.0 cN / dtex at a speed of 100 m / min is 60 to 100%.
(D) Variation in cross-sectional area of single yarn on the cut surface of the fiber is 0.5 to 10%
(E) Toughness of 180 to 350 cN · mm / dtex
(F) Fineness is 100 to 1000 dtex
(G) Single yarn fineness of 1 to 7 dtex   The polyhexamethylene adipamide fiber according to claim 1, wherein the sum of the elongation at the intermediate strength and the boiling water shrinkage is 16.0 to 20.0%. A resin-coated bag- woven airbag made of polyhexamethylene adipamide fiber that satisfies the following physical properties.
(A) The number of entanglements is 30 to 45 / m
(B) 5-30% variation in the number of entanglements
(C) The confounding number remaining ratio after tension treatment of 1.0 cN / dtex at a speed of 100 m / min is 60 to 100%.
(D) Variation in cross-sectional area of single yarn on the cut surface of the fiber is 0.5 to 10%
(E) Toughness of 180 to 350 cN · mm / dtex
(F) Fineness is 100 to 1000 dtex
(G) Single yarn fineness of 1 to 7 dtex After melting polyhexamethylene adipamide resin with relative viscosity of 50-100 formic acid, it is filtered with a back pressure of 30 kg / cm ² or more, and when the spinneret is attached, a heat retaining heater is kept in contact with the spinneret to maintain the temperature, and a Nelson roll or separator Multi-stage drawing with a roll, using an interlacer with an orifice cross-sectional area / chamber cross-sectional area ratio of 0.25 to 0.50, applying fluid energy of 3.1 MPa · Nm ³ / Hr or more, and a thread of 25 msec or more A process for producing polyhexamethylene adipamide fibers having a fineness of 100 to 1000 dtex and a single yarn fineness of 1 to 7 dtex, comprising winding after single yarn entanglement with a residence time.

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