JPH042539A - Shock absorption bag - Google Patents

Abstract

PURPOSE:To secure the safety to fire for an impact absorbing bag consisting of tapes of open yarn coated with elastomer and wound in the form of a bag by composing its inner surface of fire-resistant material. CONSTITUTION:Five yarns 5 are put together to be a tow, which is opened to obtain a tape of open yarn 1, and it is put through a rubber solution immersing device 2, so an ultra-thin tape 5 coated with rubber solution is formed. This tape 5 is wound through rollers 7 - 9 and a delivery eye 11 onto a disc-like mandrel 13 leaving no gaps. Rubber composition of a main component of a fire-resistant material of chloroprene rubber dissolved by toluene is then applied, and it is vulcanized to attach monofilaments to rubber. The mandrel 13 is then decomposed, and an impact absorbing bag is taken, its surface is inverted back, thereby an impact absorbing bag having the fire-resistant material in the inner surface is obtained.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is normally housed in the center of the steering wheel of a vehicle, and upon a vehicle collision, it senses the impact and instantaneously inflates and deploys to protect the driver, etc. The present invention relates to shock absorbing bags (so-called airbags) for ensuring safety.

[Conventional technology]

Automotive airbags are designed to instantly send gas into the bag by exploding gunpowder or the like, so they must be able to withstand the impact sufficiently and be safe to use.

The conventionally provided airbags are:
After forming a polymer coating on one side of a furan woven fabric, the two coated woven fabrics are stacked so that the coated sides face each other, and the periphery is sewn to form a bag.

For example, in the prior art section of Japanese Patent Application Laid-open No. 51-4742 (invention related to a bag for an airbag device and a manufacturing method thereof), it is stated that ``a circular piece of cloth is cut out from two square pieces of cloth and the periphery is sewn together. (hereinafter referred to as Prior Art I) In addition, as an earlier invention by the present applicant, an invention relating to a shock absorbing bag and a method for manufacturing the same (patent application (Hei 240100) (hereinafter referred to as prior art ■) [Problem to be solved by the invention] However, as in prior art I, the method of manufacturing an airbag by sewing involves many manual steps. There are problems such as it is difficult to automate and cannot be manufactured economically, the strength of the sewn parts may be lower than other parts, and it takes time and effort to inspect the strength and air permeability of the sewn parts. However, there is a problem in that the sewing itself cannot be fully trusted.

In addition, the shock absorbing bag according to Prior Art H solves the problems of Prior Art I, and is a tape-shaped spread fiber bag in which the fiber filaments are arranged in a substantially straight and parallel state. Since it has a structure in which a tape of yarn or spread yarn is wound into a bag shape, there is no need for sewing, and it is easy to manufacture, homogeneous, highly reliable, and strong.

By the way, as mentioned above, since the automatic Ichikawa airbag uses a method in which gas is sent by exploding gunpowder or the like, sparks or flames are scattered on the inner surface of the bag when it explodes. Therefore, unless the airbag is flame retardant, it cannot be said to be sufficiently safe.

However, synthetic fibers such as polyamide fibers and polyester fibers that are commonly used as materials for spread yarns are susceptible to fire and easily burn.

Therefore, the shock absorbing bag according to Prior Art H does not ensure safety against fire.

The present invention has been made in view of the above problems of the prior art, and its purpose is to provide a shock absorbing bag that is homogeneous, highly reliable, easy to manufacture, and flame retardant. be.

[Means to solve the problem]

In order to achieve the above object, the gist of the present invention is to provide a shock absorbing bag in which a tape-shaped spread yarn coated with an elastomer is rolled up into a bag shape, the inner surface of which is made of a flame-retardant material. A first invention provides a shock-absorbing bag characterized by the following: In the first invention, the flame-retardant material is an elastomer whose main component is a polymer having a halogen group in its molecular structure. A second invention is a shock-absorbing bag according to the present invention, and a third invention is a shock-absorbing bag according to the first invention, characterized in that the flame-retardant material is an elastomer containing a flame retardant.

In this specification, [tape-shaped spread yarn]

``A tape of one or several yarns (multifilament threads) arranged in a sheet shape so that the monofilaments are maintained in a substantially straight and parallel state.'' is "a product in which the monofilaments that make up the tape-shaped spread thread are mutually bonded and integrated"
when.

Examples of polymers having a halogen group in the molecular structure include polychloroprene, polyvinyl chloride, polyvinylidene chloride, chlorinated polyolefin, ethylene-vinyl chloride copolymer, chlorinated polyethylene, chlorosulfonated polyethylene, and chlorinated polyethylene. , polyvinylidene fluoride, vinylidene fluoride-hexafluorinated propylene copolymer, bolite]-lafluoroethylene I/N, polyvinyl fluoride, chlorotrifluoroethylene hnylidene fluoride copolymer, hexafluoropropyre sote 1-la Mention may be made of elastomers or non-elastomers such as fluoroethylene-vinylidene fluoride copolymers. Among these polymers, non-elastomers can be made into elastomers by adding an appropriate amount of plasticizer or by mixing with an elastomer in an appropriate ratio.

As for polymers that do not have halogen groups in their molecular structure,
Examples include elastomers such as natural rubber, urethane rubber, isoprene rubber, polybutadiene rubber, acrylic rubber, ethylene propylene rubber, and styrene phtadiene rubber.

Examples of flame retardants include organic and inorganic materials such as low molecular weight chlorinated paraffins, hexabromobenzene, ammonium bromide, chlorotetrabromobutane, hexabromocyclododecane, antimony dioxide, aluminum hydroxide, and chloroprene. . In addition, when properties such as flexibility, adhesiveness, aging resistance, and high strength are required in addition to flame retardancy, chlorobrene is preferred. These flame retardants blended with the above-mentioned elastomer having no halogen group can also be used as a coating agent to achieve the object of the present invention.

The fibers of the present invention typically include human silk, polyvinyl alcohol fibers, aliphatic and aromatic polyamide fibers,
Examples include polyester fibers, carbon fibers, glass fibers, etc., but they are not particularly limited, and include all fibers conventionally used for bonding with rubber.

The method for opening the fibers includes electrical methods, mechanical methods, methods using air flow, etc., but any method may be used as long as the purpose can be achieved. Any method is fine.

Note that the tape-shaped spread yarn obtained by the opening process must be extremely uniform (with little variation in thickness). In addition, the monofilaments must be completely separated from each other, and their spacing must be close enough that the average spacing is less than the average filament diameter.

In the present invention, the method of winding the tape-shaped spread yarn or the tape of the spread yarn into a bag shape is to wind it around a mandrel having a predetermined size and shape. Any of the following methods can be applied: traverse method, rotating arm method, and other special methods in which the arm or mandrel is wound with a special rotational motion.

By winding shape, there are three methods: wrapping closed shapes such as cocoons, spheres, and cones; winding cylindrical and disk shapes; and winding irregular shapes such as prisms and pyramids. It can also be applied by method.

Although there are various winding patterns, a predetermined strength can be imparted by broadly classifying them into parallel winding, helical winding, longitudinal winding, or a combination thereof. In cases where pressure is generated inside the bag, such as in an airbag, by forming the bag with a laminated structure of at least two or more layers with different winding directions, the pressure can be applied uniformly.

As the mandrel, when molding into a shape that can be demolded, use a deformable hollow body, such as a metal mandrel (which can be disassembled if necessary) or a rubber one,
When forming into a closed shape, use a consumable mandrel such as plaster, rock salt, or a fusible metal. In order to easily remove the mandrel after molding, it is desirable to apply a mold release agent to the mandrel in advance.

The elastomer coating on tape-shaped spread yarn is
It may be done before or after winding the tape-shaped spread yarn around the mandrel.

In addition to the dip coating method, methods for coating the tape-shaped spread yarn with elastomer include dip coating in a dispersion state, spraying the elastomer as a powder, or passing a heated filament through an atmosphere in which the elastomer is scattered. A method of melting and adhering can also be used.

The method for obtaining a bag whose inner surface is made of flame-retardant material is as follows:
The following methods can be adopted. For example, if the flame-retardant material is applied to the outer periphery of the mandrel in advance before winding the tape-shaped spread yarn or the tape of the spread yarn around the mandrel, a bag whose inner surface is made of the flame-retardant material can be obtained. be able to. Alternatively, after wrapping a tape-shaped spread yarn or a tape of spread yarn around a mandrel, coat the outer periphery with a flame-retardant material and turn it inside out to obtain a bag whose inner surface is made of a flame-retardant material. be able to. Furthermore, before winding the tape-shaped spread yarn around the mandrel, a method can be adopted in which the side corresponding to the inner surface of the hug is coated with a flame-retardant material, and the opposite side is coated with a normal elastomer.

When the elastomer is made of a rubber composition, it is desirable to perform a vulcanization treatment, and the vulcanization treatment involves fusion-welding the adjacent filaments in a crossed or parallel state with an elastomer that has previously covered the filaments. This is done to maintain the cut shape and protect the filament. The temperature condition is the temperature at which the elastomer covering the filament exhibits a predetermined adhesive force, that is, 120 to 19
0°C is desirable, taking into account thermal decomposition of the elastomer,
Harsh conditions such as heating temperatures of 200°C or more and heating times of 20 minutes or more should be avoided.

[Function] Since the inner surface of the shock-absorbing bag according to the present invention is made of a flame-retardant material, even if sparks from an explosion of gunpowder or the like within the bag adhere to the inner surface of the bag, it will easily burn. Fire safety is ensured.

〔Example〕

Examples of the present invention will be described below.

In Fig. 1, ■ is 1260D made of 66 nylon.

A tape-shaped spread yarn obtained by aligning five yarns of /315 F into a tow shape and opening the tape-shaped spread yarn 1 is passed through a rubber solution impregnating device 2 and
After impregnation with rubber solution 3 in which a rubber composition having the formulation shown in Table 1 was dissolved in toluene, the adhesion amount was controlled to 20 g/m 2 using a doctor knife 4. Arrow A indicates the traveling direction of the tape-shaped spread fiber l.

The rubber solution coated in this way has a thickness of 4 mm.
An extremely thin tape with a width of 0 μm and a width of 8 mm was obtained.

An enlarged cross-section of this child 5 is shown in FIG. In FIG. 2, 6 is a monofilament.

Then, the tape 5 is passed between opposing rollers 7.8, passed through rollers 9.10, and then passed through the disc-shaped mandrel 13.
The delivery eye 1 reciprocates in a direction parallel to the rotation axis 12 of the
1 onto a decomposable metal disk-shaped mandrel 13 coated with a release agent in advance, the tape is wound uniformly at a winding angle of 14.5° and a tape feed speed of 0° and 45 m/sec until there are no gaps. Wearing. The above-mentioned FIG. 2 is an enlarged view of the cross section of the tape 5 and the edge of the disc-shaped mandrel 13.

Thereafter, a mixture of the main component of chloroprene rubber having the composition shown in Table 2 and a sulfur rubber composition dissolved in toluene was applied onto the mandrel.

Next, the monofilaments were vulcanized under heating and pressure conditions of 180° C. and 0.5 kg/cm 2 to firmly adhere the monofilaments with rubber. Then, the disc-shaped mandrel 13 was disassembled, the shock-absorbing bag formed on the mandrel was taken out, and the bag was turned over to obtain a shock-absorbing bag whose inner surface was made of a flame-retardant material. A state in which the shock absorbing bag 14 is inflated and deployed is shown in FIG.

Table 1 Table 2 (Comparative Example) As a comparative example, a shock absorbing bag was produced in the same manner as in the example except that the rubber composition of Table 2 was not applied to the bag-shaped material wrapped around a mandrel.

(Flame retardancy test) From each of the shock absorbing bag according to the example and the shock absorbing bag according to the comparative example, a 50 mm width x 20 O mm
Cut out a test piece with a length, fix this test piece horizontally, and burn it with a burner from the bottom of the approximately central part of the test piece in the longitudinal direction, until the central part of the test piece burns out and becomes two pieces. The time until separation was measured. Note that the test piece of the example coated with a flame-retardant material was fixed so that the side of the flame-retardant material was in contact with the flame of the burner.

The results are shown in Table 3 below.

Table 3 As is clear from Table 3, the time it took for the test piece to separate into two pieces was significantly longer for the sample according to this example than for the comparative example, indicating that it had excellent flame retardancy. .

As a method for obtaining a bag whose inner surface is made of a flame-retardant material, as shown in FIG. A paste-like material 16 of a rubber composition having the composition shown in Table 1 is coated, and the bottom side of the tape-shaped spread yarn 1 (the side corresponding to the inner surface of the bag) is coated with a paste-like material 16 of a rubber composition having the composition shown in Table 2. 17 can also be coated. In this case, the coating device includes the first
It may be installed at the location of the rubber solution impregnating device 2 shown in the figure.

In addition, even if the entire inner surface of the impact-absorbing bag is not made of flame-retardant material, it can be used in areas where most of the sparks, flames, etc. will shine directly when explosives, etc. explode and the airbag expands and deploys. That is, only a part of the inner surface of the bag corresponding to the side opposite to the opening 18 of the shock absorbing bag 14 in FIG. 3 may be made of a flame-retardant material, and the other part may be made of a normal elastomer. .

[Effects of the Invention] (1) According to the present invention, a highly safe impact-absorbing bag that is tough, has excellent flame retardancy, and can be provided at a low cost.

■The shock absorbing bag according to the present invention is suitable for use with gases that may be exposed to sparks, flames, etc. during use, such as air/N lugs for automobiles, hot air balloons, atto balloons, etc. Balloons for airships, gas bags for blocking blasts caused by underground explosions, fuel tanks for liquids, etc.
Furthermore, it can be suitably used as a heat-resistant and heat-insulating material for civil engineering construction work.

[Brief explanation of drawings]

Figure 1 is a side view of each process of manufacturing the shock absorbing bag of the present invention, Figure 2 is an enlarged view of the cross section of the tape coated with rubber solution and the edge of the mandrel, and Figure 3 is the shock absorbing bag. FIG. 4 is a perspective view showing a state in which the rubber composition is expanded and expanded, and FIG.

Claims (1)

[Claims] 1) A shock absorbing bag in which a tape-shaped spread yarn coated with an elastomer is wound into a bag shape,
Shock-absorbing bag characterized in that the inner surface is made of a flame-retardant material 2) A claim characterized in that the flame-retardant material is an elastomer whose main component is a polymer having a halogen group in its molecular structure. 3) The shock absorbing bag according to claim 1, wherein the flame retardant material is an elastomer containing a flame retardant.