JP4826367B2 - Seat belt webbing - Google Patents

Description

  The present invention relates to a vehicle seat belt webbing. More specifically, the present invention relates to a seat belt webbing that has high strength, excellent energy absorption ability, and retains moderate rigidity to further improve the winding performance of the retractor.

  Seat belts are indispensable as a device for ensuring the safety of passengers in automobiles and aircraft, and are installed in almost all automobiles and aircraft. The characteristics required of the seat belt include firstly high strength that does not easily break when subjected to a large impact in a collision or the like, and a high energy absorption capacity that softens the impact on the occupant. In addition, the so-called winding performance in which the webbing is smoothly pulled out from a belt winding device called a retractor and is smoothly wound is an indispensable characteristic in order to fulfill the original function of the seat belt. In particular, as the retractor itself is becoming lighter and more compact, the webbing is required to be lighter and thinner. It has become an increasingly important and difficult task to ensure smooth access to the retractor.

  Against this background, various technical proposals have been made in order to improve the retracting performance of the seat belt webbing onto the retractor. Among them, a method for improving the winding performance by increasing the rigidity of the webbing itself, particularly the rigidity in the horizontal direction of the webbing and maintaining a stable form is the most effective, and can be said to be an advantageous method in terms of cost.

  Patent Documents 1 and 2 disclose a technique for improving the form stability by increasing the rigidity of the webbing by using a highly rigid monofilament for the weft yarn constituting the seat belt webbing. However, the monofilaments used in these methods have a too high rigidity to deteriorate the weaving property, and in order to ensure the weaving property, the weaving speed must be extremely reduced. The problem remained. In addition, since a monofilament having a large fiber diameter is used, there is a problem that the thickness of the webbing increases, which is not satisfactory in that a thin webbing that has been required in recent years can be realized.

  Patent Documents 3 and 4 propose a technique in which a modified multifilament such as a Y-type, a Δ-type, a C-type, or a hollow type is used for the weft yarn constituting the webbing. These technologies are expected to increase the stiffness of the webbing by increasing the stiffness of the weft yarn itself, as in the technical ideas of Patent Documents 1 and 2, but the effect is not always sufficient, depending on the webbing design and weaving conditions. There was even no effect of increasing the rigidity.

Patent Document 5 discloses a seatbelt webbing in which multifilaments having a single yarn cross-sectional shape are flat, and the flat cross-sections of each single yarn are highly arranged in the webbing. According to this method, the single fibers in the webbing have a close-packed structure, and both thinning and form stabilization can be achieved. However, in order to obtain a sufficient effect, it is necessary to highly control the weaving tension, heating temperature, nip pressure, etc. in the webbing manufacturing process, and the flat cross-sectional direction is not aligned due to slight disturbance of conditions, but rather thick and low in rigidity. Sometimes it became webbing.
US Pat. No. 4,107,371 JP 2003-41431 A (Claims) JP-A-7-228218 (Claims) JP 2000-190811 A (Claims) JP 2004-315984 A (Claims)

  The present invention has been achieved as a result of examining the problems that could not be solved by the above-described conventional technology, that is, having high strength, excellent energy absorption ability, and maintaining appropriate rigidity. An object of the present invention is to provide a seat belt webbing with further improved winding performance without performing a special weaving / dyeing process.

  In order to achieve the above object, the present invention mainly has the following configuration. That is, it is a seat belt webbing using multifilaments for warp yarn and weft yarn, and the warp yarn bites into the weft yarn in the webbing, and the bite degree is 3 to 20%.

Furthermore, in the seat belt webbing of the present invention, it is a preferable aspect to satisfy any one of the following (a) to (d) or a combination thereof, and further excellent effects can be expected.
(A) The total fineness T * N per unit width represented by the product of the fineness T (dtex) of the warp yarns constituting the webbing and the number N (lines / inch) of driving satisfies the following formula.
T * N (dtex / inch) = 177,000-245,000
(B) The crystallinity (σ) of the weft yarn constituting the webbing is 25 to 34%.
(C) The cross-sectional shape of the single yarn constituting the webbing has a protrusion.
(D) The cross-sectional shape of the single yarn constituting the webbing is Y-shaped.

  The seat belt webbing of the present invention has high strength, excellent energy absorption capability, and maintains appropriate rigidity, so that the winding performance of the retractor can be further improved. Therefore, it can be particularly suitably used for a thin seat belt that has recently been required. The seat belt webbing of the present invention can be produced without requiring a special weaving / dyeing process.

  The present invention is described in detail below.

  Synthetic fibers such as polyester fiber, polyamide fiber, polyolefin fiber, and polyvinyl alcohol fiber are used for the warp yarn and the weft yarn constituting the seat belt webbing of the present invention, although not particularly limited, high strength as a webbing, In order to obtain an excellent energy absorption capacity, a polyester fiber, particularly polyethylene terephthalate fiber is most preferable. In addition, some of the polymers include acid components such as isophthalic acid, adipic acid, sebacic acid, 2,6-naphthalenedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, butanediol, hexanediol, diethylene glycol, neopentyl glycol, 1, It may contain a diol component such as 4-cyclohexanediol. The main purpose of the polymer is matte, inorganic materials such as titanium oxide, calcium carbonate, kaolin and clay, benzophenone and benzotriazole UV absorbers, antioxidants, radical scavengers, etc. for the purpose of improving weather resistance Even if it contains, there is no problem. Furthermore, the polymer may contain a colorant. Examples of the colorant include inorganic colorants such as carbon black, zinc oxide, and iron oxide, and organic colorants such as cyanine, phthalocyanine, anthraquinone, azo, perinone, styrene, and quinacdrine. When a polymer containing these colorants is used, there is an advantage that the dyeing process can be omitted in the seat belt webbing manufacturing process.

  The higher the degree of polymerization of the polymer used for obtaining high strength and high energy absorbing fibers, the better. In the case of polyethylene terephthalate, the intrinsic viscosity is 0.8 or more, preferably 0.9 or more, more preferably 1.0 or more.

  The warp yarn and the weft yarn constituting the seat belt webbing of the present invention are multifilaments. The multifilament is an aggregate of thin single fibers, and each single fiber is appropriately arranged in the webbing, so that a webbing having a thin and uniform thickness can be obtained. In addition, the multifilament has an appropriate rigidity and is extremely excellent in handleability in the weaving / dyeing process. On the other hand, monofilaments with high rigidity are used for some seat belt webbings, but as mentioned above, it is difficult to handle and the weaving property deteriorates, and it is necessary to reduce the weaving speed extremely to ensure the weaving property. There is. Further, when a monofilament having a large fiber diameter is used, the thickness of the webbing is increased, and there is a problem in that a thin webbing that has been required in recent years is obtained.

  In the seat belt webbing of the present invention, as shown in FIG. 1 and FIG. 2, it is the most important requirement that the warp yarn is in a state of being caught in the weft yarn, and the degree of biting is 3 to 20%. It is. Here, the degree of biting of the warp yarn into the weft yarn can be calculated from the weft cross section observed when the webbing is cut in the warp direction (perpendicular to the weft yarn). That is, it means the area ratio of the portion where the warp yarn is bitten with respect to the original weft cross section, and is represented by the area ratio occupied by the hatched portion with respect to the cross section of the weft yarn in FIG.

  This biting firmly holds the mutual positional relationship between the warp yarn and the weft yarn in the webbing, which in turn contributes greatly to an increase in webbing rigidity and form stability. When the degree of biting is less than 3%, when an external force such as bending is applied to the webbing, the mutual positional relationship between the warp yarn and the weft yarn constituting the webbing easily collapses, causing twist and breakage to the retractor. Winding property will deteriorate. On the other hand, if the degree of biting exceeds 20%, the strength of the warp yarn and the weft yarn itself is partially reduced, and sufficient webbing strength cannot be ensured. In addition, while the initial webbing rigidity becomes too high, there is a disadvantage that the rigidity is greatly reduced when an external force such as bending is repeatedly applied.

  Here, of course, it is not necessary that all the single fibers forming the weft are in a state of being bitten, and some of the single fibers that are in direct contact with the warp yarn are at most about 10% of the single fibers forming the weft. If it is bitten, the effect of increasing the rigidity of the webbing is greatly exhibited.

  The total fineness and single yarn fineness of the warp yarns constituting the webbing are preferably 800 to 2000 dtex and 10 to 25 dtex, respectively. In order to efficiently obtain a seat belt webbing having high breaking strength and excellent energy absorption performance, it is preferable to use a warp yarn having such a fineness range.

  Further, the number of warp yarns to be driven in the webbing is preferably 60 to 160 yarns / inch, more preferably 100 to 150 yarns / inch, although it depends on the warp yarn fineness. Further, the total fineness T * N (dtex / inch) per unit width expressed by the product of the fineness T (dtex) of the warp yarn constituting the webbing and the number N of yarns driven (inch / inch) = 177,000 to 245,000 It is preferable that it is 200,000-230,000. If the total fineness per unit width is less than 177,000, there is a possibility that a webbing having sufficient rigidity cannot be obtained no matter how much the warp yarn is bitten into the weft yarn in the webbing. There is also concern about the lack of strength in webbing. If the total fineness per unit width exceeds 245,000, the webbing becomes too thick or too hard, causing discomfort during wearing, and it is difficult to obtain a thin webbing that has recently been required.

Since the degree of biting of the fibers of the webbing of the present invention depends on the crystallinity of the weft, the crystallinity (σ) of the weft constituting the webbing is preferably 25 to 34%, more preferably 28. ~ 32%. The crystallinity σ referred to here is a value calculated using the theoretical formula shown below based on the heat of crystal fusion ΔHm measured by a differential scanning calorimeter (DSC).
σ = ΔHm / 33.5 * 100 (%)
ΔHm: heat of crystal melting measured by DSC (cal / g)
Theoretical heat of fusion of complete crystal: 33.5 (cal / g)

  The degree of crystallinity can be considered as one of indices indicating the material hardness of the fiber, that is, the ease of compressive deformation. The preferable range of 25 to 34% of the weft crystallinity described above means that the weft yarn has a relatively low crystallinity and is easily compressed and deformed. Appropriate rigidity develops as a seat belt webbing bitten into the weft. In order to keep the crystallinity low, it can be achieved by lowering the tension during stretching and lowering the heat treatment temperature after final stretching. This is because if the tension during stretching is low, the orientation is insufficient and crystallization is difficult to proceed, and if the heat treatment temperature after stretching is low, the orientation due to stretching is not fixed, and crystallization returns.

  The cross-sectional shape of the single yarn of the weft constituting the webbing preferably has a protrusion, more preferably a Y-shaped cross section having three protrusions. The degree of deformation represented by the ratio R / r when the diameter R of the circumscribed circle and the diameter r of the inscribed circle in the Y-shaped cross section are 1.5 to 3.5 is preferable. 2.0-3.0. By using the fiber having the protrusion as the weft, there is an advantage that the warp yarn is easily bitten. This is due to the fact that the projecting shape increases the contact area with the warp yarn and that the projecting portion is particularly susceptible to compressive deformation.

  The total fineness and single yarn fineness of the weft yarn also affect the degree of biting with the warp yarn, and preferably the total fineness is 200 to 1000 dtex, the single yarn fineness is 5 to 30 dtex, and more preferably the total fineness is 500 to 1000 detex. The single yarn fineness is 15 to 30 detex.

  Subsequently, examples of the method for producing the warp yarn and the weft yarn constituting the seat belt webbing of the present invention will be shown, but the present invention is not limited to these methods.

  Polyethylene terephthalate having an intrinsic viscosity of 1.0 or more is melted and filtered, and then spun from the mouthpiece pores. Here, the shape of the die pores may be designed in consideration of a change in cross-sectional shape until the melt-spun yarn is cooled and solidified. The spun yarn passes through an atmosphere heated to a temperature higher than the melting point of the polymer, for example, 270 to 350 ° C., and then cooled and solidified with cooling air of 50 ° C. or lower. By passing through such a temperature history, high-strength, high-energy-absorbing fibers can be manufactured with high quality. The cooled yarn is provided with an oil and wound around a take-up roller that rotates at a predetermined rotation speed. Subsequently, the film is stretched by winding around a roller that rotates at high speed sequentially. In order to obtain fibers with higher strength, it is preferable to carry out the magnification of 3.5 to 6.0 times in two or three stages.

  The surface temperature of each roller is important in determining the physical properties and quality of the fiber to be obtained, and the final drawing roller temperature must be selected appropriately. In order to obtain a high strength and high dimensional stability fiber, it is usually set to 220 to 250 ° C. On the other hand, when the temperature is set lower than this range, for example, 180 to 220 ° C., crystallization inside the fiber is suppressed to some extent, and it is possible to obtain a fiber having a low degree of crystallinity, that is, relatively soft and easy to compress and deform. .

  After stretching, a fiber having excellent shape stability can be obtained by performing a relaxation treatment of about 1 to 5%. In addition, it is preferable to entangle the traveling yarn with high-pressure air before winding. It is desirable that the entanglement applied to the yarn is large and uniform, and the number of entanglements (CF value) per 1 m of fiber length is sufficient if it is 15-30. By performing the entanglement treatment on the yarn, it is possible to improve the passability of high-order processes such as warping and weaving processes, and to obtain a high-quality seat belt webbing in a high yield.

  As a method for producing the seat belt webbing of the present invention, a conventional method can be used. For example, for weaving, a method in which the polyethylene terephthalate fiber obtained by the above method is directly passed through a needle type loom can be mentioned. The warp yarn tension during weaving may be controlled to about 0.1 to 2.0 cN / dtex, and the weft driving tension may be controlled to about 0.1 to 2.0 cN / dtex. In the subsequent dyeing process, the webbing obtained in the weaving process may be immersed in a dyeing solution containing a known disperse dye for polyester and an auxiliary agent, and then sequentially processed in a color developing tank, a washing tank, and a heat setting tank.

  The seat belt webbing thus obtained has a high strength and a high toughness, and is further excellent in winding performance. The greatest feature of the seat belt webbing of the present invention is that the warp yarn is in a state of being bitten into the weft yarn, but it does not require a special weaving and dyeing process, and the warp used for obtaining the webbing. This can be achieved by appropriately controlling the cross-sectional shape and internal structure of the yarn and the weft.

  Hereinafter, the present invention will be described specifically by way of examples. Various physical properties were calculated by the following methods.

[Intrinsic viscosity of polymer (IV)]:
The relative viscosity ηr of a solution obtained by adding 100 ml of orthochlorophenol to 8.0 g of a sample and heating and dissolving at 160 ° C. for 10 minutes was measured using an Ostwald viscometer, and calculated according to the following approximate expression.
IV = 0.0242ηr + 0.02634

[Total fineness]:
JIS L1013 8.3.1 Positive amount fineness a) Measured according to method A at 5 mN / tex × display tex number as a predetermined load and 90 m as a predetermined yarn length.

[Degree of deformation of single yarn cross section]:
The fiber was cut in a direction perpendicular to the fiber axis, and the cross section thereof was photographed at 200 times using an optical microscope (VH-6300 manufactured by Keyence Corporation). Twenty cross-sections were selected from the photograph, the diameter R of the circumscribed circle and the diameter r of the inscribed circle were measured and calculated by the following formulas, and the average value was taken as the degree of deformation.
Degree of deformation = R / r

[Strength / Elongation]:
The sample was measured in a temperature-controlled room with an air temperature of 20 ° C. and a humidity of 65% using “TENSILON” UCT-100 manufactured by Orientec Co., Ltd. under the constant speed extension conditions shown in the JIS L1013 8.5.1 standard time test. did. At this time, the grip interval was 25 cm, the pulling speed was 30 cm / min, and the number of tests was 10 times. The elongation at break was determined from the elongation at the point showing the maximum strength in the SS curve.

[Dry heat shrinkage]:
JIS L-1013 8.18.2 Dry heat shrinkage rate a) According to the skein shrinkage rate (Method A), the predetermined load at the time of sampling is 5 mN / tex × the number of displayed tex, the processing temperature is 150 ° C. The predetermined load at the time of long measurement was measured as 200 mN / tex × display tex number.

[Number of confounding (CF value)]:
A load of 100 g was applied to a sample having a test length of 1 m, and a 6 g hook was lowered at a descending speed of 1 to 2 cm / sec.
CF value = 100 (cm) / Descent distance (cm)

[Crystallinity]:
First, 10 mg of a sample was collected, and the SSC5200 thermal analysis system manufactured by Seiko Instruments Inc. was used to measure from 20 ° C. to 300 ° C. under a temperature rising rate of 10 ° C./min, and the crystal melting heat amount ΔHm was measured. Next, the degree of crystallinity (σ) was calculated from the following equation using the theoretical calorific value generated when the polyester complete crystal melts.
Crystallinity σ = ΔHm / 33.5 * 100 (%)
ΔHm: measured value of calorie melting (cal / g),
Theoretical heat of fusion of complete crystal: 33.5 (cal / g)

[Degree of biting of warp yarn into weft yarn in webbing]:
The seat belt webbing was cut in the vertical direction (perpendicular to the weft yarn), and the weft cross section was photographed at 150x using an optical microscope (VH-6300 manufactured by Keyence Corporation). Select five cross-sections from the photograph, measure the cross-sectional area (S) of the original weft yarn, and the area (s) of the portion where the warp yarn is bitten, and calculate it by the following formula. did.
Degree of biting = s / S * 100 (%)

[Total fineness per unit width in webbing]:
Based on the warp yarn fineness (T) dtex and the number of warp yarns driven (N) / inch, and also on the side yarn fineness (T) dtex and the number of warp yarns driven (N) / inch It was calculated by the following formula.
Total fineness per unit width (dtex / inch) = T * N

[Tensile strength of webbing]:
JIS D-4604 7.4 (1) Standard state performance test (1.1) Measured according to tensile strength test.

[Webbing rigidity]:
According to the method of JIS L-1096 8.20.1, a sample having a length of 38.1 mm and a width of 12.7 mm was collected and measured using a Gurley type stiffness tester manufactured by Tester Sangyo Co., Ltd.

[Weaving property]:
The number of stops of the needle loom due to yarn breakage and fluff was recorded. When the number of stops per hour was less than 2 times, it was evaluated as ○, and 2 times or more as ×.

[Example 1]
<Vertical yarn>
A polyethylene terephthalate polymer chip having an intrinsic viscosity of 1.2 containing 0.1% by weight of titanium oxide was melted with an extruder-type spinning machine, measured with a metering pump, filtered in a spinning pack, and spun from a spinneret. The temperatures of the extruder, spin block, and spin pack were adjusted so that the melt polymer temperature was 300 ° C. A spinneret having a hole number of 144 and a circular hole type was used.

  The spun yarn was passed through a heating tube having a temperature of 320 ° C. and a length of 300 mm, and then a cooling air of 20 ° C. was blown onto the yarn at a wind speed of 30 m / min to be cooled and solidified. Next, after applying an oil agent to the cooling yarn, it was wound around an unheated take-up roller rotating at a speed of 600 m / min. Subsequently, the film was wound around a supply roller that was sequentially rotated at a high speed without being wound once, a first stretching roller, a second stretching roller, and a relaxation roller that was rotated at a lower speed than the second stretching roller, and subjected to stretching and relaxation heat treatment. The total draw ratio is 5.8 times, the relaxation rate is 2%, the surface temperature of each roller is 80 ° C for the supply roller, 120 ° C for the first draw roller, 240 ° C for the second draw (final draw) roller, and the relax roller Was set to 40 ° C., respectively. The yarn after the drawing / relaxation heat treatment was entangled with high-pressure air and wound up by a winder.

<Horizontal thread>
A polyethylene terephthalate polymer chip having an intrinsic viscosity of 1.2 containing 0.1% by weight of titanium oxide was melted with an extruder-type spinning machine, measured with a metering pump, filtered in a spinning pack, and spun from a spinneret. The temperatures of the extruder, spin block, and spin pack were adjusted so that the melt polymer temperature was 300 ° C. As the spinneret, a Y-hole type with 42 holes was used.

  The spun yarn was passed through a heating tube having a temperature of 320 ° C. and a length of 200 mm, and then a cooling air of 20 ° C. was blown onto the yarn at a wind speed of 30 m / min to be cooled and solidified. Next, after applying an oil agent to the cooling yarn, it was wound around an unheated take-up roller rotating at a speed of 800 m / min. Subsequently, the film was wound around a supply roller that was sequentially rotated at a high speed without being wound once, a first stretching roller, a second stretching roller, and a relaxation roller that was rotated at a lower speed than the second stretching roller, and subjected to stretching and relaxation heat treatment. The total draw ratio is 4.2 times, the relaxation rate is 3%, the surface temperature of each roller is 80 ° C for the supply roller, 120 ° C for the first draw roller, 210 ° C for the second draw (final draw) roller, and the relax roller Was set to 40 ° C., respectively. The yarn after the drawing / relaxation heat treatment was entangled with high-pressure air and wound up by a winder.

<Webbing>
Next, the obtained warp yarns were lined up and guided directly to a needle type loom so that the number of driven yarns was 135 yarns / inch, and the weft yarn number of yarns was 20 yarns / inch. The tension during weaving was adjusted to a warp thread tension of 0.5 cN / dtex and a weft thread tension of 0.5 cN / dtex. Next, a heat treatment was performed for 1 minute under a dry heat of 200 ° C. to obtain a webbing. Subsequently, the obtained webbing is immersed in a disperse dye bath, colored in a 200 ° C. coloring bath, excess dye is washed away in a washing bath, and heat treated for 1 minute under dry heat at 150 ° C. A belt webbing was produced. The results are shown in Table 1.

[Examples 2 to 4]
<Vertical yarn>
It was produced by the same method as in Example 1.

<Horizontal thread>
It was produced by the same method as in Example 1.

<Webbing>
A webbing was obtained in the same manner as in Example 1, except that the number of warp yarns during weaving was adjusted to 115 / inch in Example 2, 105 / inch in Example 3, and 150 / inch in Example 4. It was. Subsequently, dyeing and heat treatment were performed in the same manner as in Example 1 to produce a seat belt webbing. The results are shown in Table 1.

[Examples 5 and 6]
<Vertical yarn>
It was produced by the same method as in Example 1.

<Horizontal thread>
Manufactured in the same manner as in Example 1 except that the surface temperature and the relaxation rate of the final drawing roller during drawing / relaxation heat treatment were set to 190 ° C. and 3% in Example 5 and 175 ° C. and 4% in Example 6, respectively. did.

<Webbing>
A seat belt webbing was produced in the same manner as in Example 1. The results are shown in Table 1.

[Examples 7 and 8]
<Vertical yarn>
It was produced by the same method as in Example 1.

<Horizontal thread>
The spinneret was prepared in the same manner as in Example 1 except that the number and the hole shape of the spinneret were 72 · hexagonal hole type in Example 7 and 96 · circular hole type in Example 8.

<Webbing>
A seat belt webbing was produced in the same manner as in Example 1. The results are shown in Table 1.

[Comparative Example 1]
<Vertical yarn>
It was produced by the same method as in Example 1.

<Horizontal thread>
Implemented except that the number of holes in the spinneret was 96, the hole shape was a circular hole shape, the draw ratio during drawing / relaxation heat treatment was 5.7 times, the surface temperature of the final drawing roller was 245 ° C, and the relaxation rate was 2%. The same method as in Example 1 was used.

<Webbing>
A seat belt webbing was produced in the same manner as in Example 1. The results are shown in Table 1.

[Comparative Example 2]
<Vertical yarn>
It was produced by the same method as in Example 1.

<Horizontal thread>
The same spinneret as in Comparative Example 1 was used, except that the draw ratio during drawing / relaxation heat treatment was 3.7 times, the surface temperature of the final drawing roller was 160 ° C., and the relaxation rate was 4%. It was produced by the method.

<Webbing>
A seat belt webbing was produced in the same manner as in Example 1. The results are shown in Table 1.

[Comparative Example 3]
<Vertical yarn>
It was produced by the same method as in Example 1.

<Horizontal thread>
A polyester monofilament of 830T-1 filament was obtained from Toray Monofilament Co., Ltd.

<Webbing>
A seat belt webbing was produced in the same manner as in Example 1. The results are shown in Table 1.

  Table 1 also shows the warp yarns, weft yarn properties, webbing design, and properties obtained by the methods of Examples 1 to 8 and Comparative Examples 1 to 3.

  As apparent from Table 1, the seat belt webbing of the present invention has a structure in which the warp yarn is appropriately bitten into the weft yarn, and has both high breaking strength and appropriate rigidity. On the other hand, in Comparative Example 1 in which the degree of biting between the warp yarn and the weft yarn is less than the range of the present invention, the rigidity in both the warp direction and the weft direction is low, leaving uneasy about the winding performance of the seat belt webbing. Further, in Comparative Example 2 in which the degree of biting exceeds the range of the present invention, the webbing strength is insufficient and the role as a safety device is not sufficiently fulfilled. In Comparative Example 3 in which the monofilament was used as the weft, since the monofilament was too rigid, the weaving property was greatly deteriorated, and the seat belt webbing could not be obtained efficiently.

  The seat belt webbing of the present invention has high strength and excellent energy absorption ability, and further improves the retracting performance to the retractor by maintaining appropriate rigidity. Particularly preferably used. Further, the seat belt webbing of the present invention can be produced without requiring a special weaving / dyeing process.

It is a schematic diagram of a part of webbing of the present invention. It is a cross-sectional schematic diagram which cut | disconnected perpendicularly the warp yarn cross section of the webbing of this invention. It is a cross-sectional schematic diagram which cut | disconnected the weft cross section of the webbing of this invention perpendicularly | vertically.

Claims (3)

A seatbelt webbing using multifilaments for warp and weft yarns, wherein the warp yarns bite into the weft yarns within the webbing, and the degree of biting is 3 to 20%, and the warp yarns constituting the webbing The total fineness T * N per unit width represented by the product of the fineness T (dtex) and the number of driven N (lines / inch) satisfies the following formula, and the crystallinity (σ) of the weft yarn constituting the webbing is A seat belt webbing characterized by being 25 to 34% .
T * N (dtex / inch) = 177,000-245,000 The seat belt webbing according to claim 1 , wherein a cross-sectional shape of a single yarn of the weft constituting the webbing has a protrusion. The seat belt webbing according to claim 2 , wherein a cross-sectional shape of a single yarn of the weft constituting the webbing is a Y type.

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