WO2024117138A1 - 内圧保持性能を高めたエアバッグの製法 - Google Patents

内圧保持性能を高めたエアバッグの製法 Download PDF

Info

Publication number
WO2024117138A1
WO2024117138A1 PCT/JP2023/042592 JP2023042592W WO2024117138A1 WO 2024117138 A1 WO2024117138 A1 WO 2024117138A1 JP 2023042592 W JP2023042592 W JP 2023042592W WO 2024117138 A1 WO2024117138 A1 WO 2024117138A1
Authority
WO
WIPO (PCT)
Prior art keywords
base fabric
film
airbag
protective material
fabric panels
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/JP2023/042592
Other languages
English (en)
French (fr)
Japanese (ja)
Inventor
拓海 壁谷
達夫 田中
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Asahi Kasei Corp
Asahi Chemical Industry Co Ltd
Original Assignee
Asahi Kasei Corp
Asahi Chemical Industry Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Asahi Kasei Corp, Asahi Chemical Industry Co Ltd filed Critical Asahi Kasei Corp
Priority to JP2024561517A priority Critical patent/JPWO2024117138A1/ja
Publication of WO2024117138A1 publication Critical patent/WO2024117138A1/ja
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
    • B60R21/00—Arrangements or fittings on vehicles for protecting or preventing injuries to occupants or pedestrians in case of accidents or other traffic risks
    • B60R21/02—Occupant safety arrangements or fittings, e.g. crash pads
    • B60R21/16—Inflatable occupant restraints or confinements designed to inflate upon impact or impending impact, e.g. air bags
    • B60R21/23—Inflatable members
    • B60R21/231—Inflatable members characterised by their shape, construction or spatial configuration

Definitions

  • the present invention relates to a method for manufacturing an airbag used in an airbag device mounted on a vehicle. More specifically, the present invention relates to a method for manufacturing an airbag in which the outer edges of a pair of base fabric panels are sewn together, and which has improved internal pressure retention performance.
  • airbags used in airbag devices mounted on vehicles are made by sewing (stitching) the outer edges of a pair of base fabric panels together to form a bag-like shape, into which gas is instantly injected to inflate and deploy.
  • sewing is usually done using sewing thread, gas leakage between the pair of base fabric panels and through the holes in the sewing needle is unavoidable.
  • Airbags absorb impacts on the human body by retaining injected gas.
  • DABs meet performance requirements if they can handle instantaneous impacts (first impacts).
  • CABs must maintain the inflated state of the airbag even during the rotation (rollover) of the vehicle after the first impact, and are required to maintain a constant pressure (e.g., 30 kPa) or higher (i.e., internal pressure maintenance) within the airbag for a long period of time (e.g., six seconds).
  • a constant pressure e.g. 30 kPa
  • internal pressure maintenance i.e., internal pressure maintenance
  • pedestrian airbags require internal pressure maintenance for a longer period of time than DABs, because the timing at which a pedestrian lands on the bonnet and hits the vehicle body (e.g., the pillar section) varies.
  • One method is to bond the outer edges of a pair of base fabric panels with only an adhesive instead of sewing. Although this method can prevent gas leakage, there is a risk that the adhesive will not be able to withstand the strength required for the airbag to deploy because there is no sewing.
  • Another method is to manufacture a pair of base fabric panels using the One Piece Woven method and then coat the outside of the base fabric.
  • This method there are no stitching and the coating means there is no problem with airtightness, and there are no problems with strength either, but it is difficult to create complex shapes, the coating needs to be applied relatively thickly, and this tends to increase the weight of the airbag, and it is also expensive.
  • Another method is to bond the outer edges of a pair of base fabric panels with a silicone adhesive and then sew the bonded portion.
  • This method can ensure strength while suppressing gas leakage, but it has problems such as low productivity, thick bonded portions, and poor folding and storage properties of the airbag.
  • the weight of the silicone adhesive increases the weight of the airbag. As illustrated in FIG. 2, in this method, the silicone adhesive stretches during airbag deployment, preventing gas from accessing the stitching.
  • silicone adhesives are suitable for such applications because of their high adhesive strength with base fabric panels, but the adhesive takes half a day to about a day to harden, resulting in low productivity, and for example, the folded thickness of a pair of base fabric panels is 2.2 mm at the location where there is no adhesive (location where internal pressure does not need to be maintained), whereas the folded thickness at the location where there is adhesive and stitching is 5.2 mm, resulting in a lack of compactness (foldability, storability). Furthermore, silicone adhesives must be separated from the airbag fabric when recycled, and they emit a relatively large amount of GHG (Green House Gas) during production, so they are not environmentally friendly in the manufacture and disposal of airbags.
  • GHG Green House Gas
  • Patent Document 1 describes an airbag device having a protective cloth sewn along a seam where a pair of opposing portions of a base fabric are sewn together, at a position away from the seam so as to cover the seam from the inside where gas from the inflator is introduced (see Figures 2 and 7 of the same document).
  • Patent Document 1 discloses a protective material for the seam, but this protective material is fixed to the base fabric by sewing, not by adhesion. The purpose of this protective material is to prevent the seam from being directly exposed to the high-pressure gas from the inflator and being destroyed, and to distribute tension in the protective material's seam to prevent damage to the seam of the pair of base fabrics, but is not intended to maintain internal pressure without damaging the seam.
  • Patent Document 2 discloses an airbag having walls including a laminate material, the laminate material including a backing layer having a breathable sheet-like structure made of a woven or knitted fabric, at least two layers of coextruded polymer film, a first polymer layer having a predetermined glass transition temperature on the backing layer side, and a second polymer layer having a predetermined storage modulus on the opposite side to the backing layer, the airbag having walls bonded together such that the second polymer layer is bonded at the edge of the airbag, and a manufacturing method for bonding the first polymer layer and the second polymer layer by applying different thermal energies to them.
  • 5,399,633 is to provide an airbag which can be produced at low cost and which is easy and reliable to seal (see Figs. 1-3 of the same document).
  • Patent Document 2 does not disclose any protective material for the seams of the airbag, and the manufacturing method therefor is primarily intended to increase productivity, not to maintain internal pressure.
  • Patent Document 3 describes an airbag in which panels are joined together at joints, the panels having a woven fabric and a synthetic resin film bonded to the woven fabric via an adhesive, the panels are joined together by pressurizing and heating with a hot melt adhesive sheet interposed between the panels, and the synthetic resin film is disposed on the outside of the airbag.
  • the object of the invention described in Patent Document 3 is to provide an airbag in which the strength of the seams between the panels is high, the durability is excellent, gas leakage is prevented, and handling is easy (see Figures 3 and 4).
  • Patent Document 3 does not describe a method for preventing gas leakage from stitching holes due to stress being applied to the joints between the panels when the adhesive surface around the outer periphery of the airbag is stressed during deployment, which may cause the adhesive to break.Furthermore, there is no mention of the technical idea of adhering a protective material for the stitching to the base fabric at a location separate from the stitching, and maintaining the adhesion between the protective material and the base fabric to maintain the internal pressure.
  • the problem that the present invention aims to solve is to provide a highly productive method for manufacturing an airbag in which a pair of base fabric panels are sewn together at their outer periphery to form a bag body, in which an airtight structure is formed by bonding both outer surfaces of a half-folded, strip-shaped, non-breathable protective material to the inner surface of each of the pair of base fabric panels in a bonding region of a predetermined width along the stitching from near the stitching toward the inside of the bag body, the bonding region having a proximal end and a distal end, and which maintains this structure even when the airbag is deployed, thereby improving the internal pressure retention performance, and providing a low-cost, highly productive, and highly compact airbag manufacturing method.
  • the present invention is as follows.
  • a method for manufacturing an airbag having at least one pair of base fabric panels sewn together at their outer periphery comprising the steps of: a welding step of continuously sandwiching a semi-folded, band-shaped non-breathable film-like protective material, which is made of a monolayer resin film having a predetermined width with a release paper sandwiched therebetween or a laminated resin film having two or more layers including a first surface layer and a second surface layer, between the inner surfaces of the pair of base fabric panels while applying tension to the material along the linear or curved outer periphery of the pair of base fabric panels, and applying heat or ultrasonic waves from the outside of the pair of base fabric panels to weld a surface of the monolayer resin film or the first surface layer to the inner surface of the base fabric panel in an adhesive region of a predetermined width, wherein although the surfaces of the monolayer resin film on the release paper side are not welded to each other due to the presence of the release paper, or the second surface layers of the laminated resin film are not welded
  • [3] A step of heating a part or the whole of the half-folded, band-shaped, non-breathable film-like protective material before a welding step of welding the half-folded, band-shaped, non-breathable film-like protective material;
  • the method according to any one of the above [1] to [3], [5] In the welding process of welding the half-folded band-shaped non-breathable film-like protective material, a process of heating and/or cooling a part or the whole of the half-folded band-shaped non-breathable film-like protective material while intermittently applying/releasing the pressure of a hot plate and/or a cold plate;
  • the method for manufacturing an airbag according to the present invention comprises bonding the outer surfaces of both ends of a folded, strip-shaped, non-breathable protective material to the inner surface of each of at least a pair of base fabric panels in bonding areas of a predetermined width along the seams, having proximal and distal ends from near the seams toward the inside of the bag, and when a tensile force is applied to the pair of base fabric panels when the airbag is deployed, substantially no tensile force is applied to the bonding areas, thereby maintaining an airtight structure.
  • this method for manufacturing an airbag has high internal pressure retention performance, is low cost, has high productivity, and is also highly compact. Therefore, the airbag and the manufacturing method thereof according to the present invention can be suitably used for automobile airbags, in particular for CABs and pedestrian airbags which require high internal pressure retention performance.
  • FIG. 1 is a plan view of an airbag in which a pair of base fabric panels are sewn together at their outer periphery to form a bag body, which can be manufactured by the manufacturing method of this embodiment.
  • 2 is an explanatory diagram of a state of an airbag when deployed, in a location corresponding to the cross section AA in FIG. 1, in which a portion bonded with a silicone adhesive is sewn.
  • FIG. FIG. 2 is an explanatory diagram of the state of a non-breathable protective material in an airbag that can be manufactured by the manufacturing method of this embodiment when the airbag is deployed.
  • 1 is an explanatory diagram showing the relationship between the resin constituting the first surface layer and the resin constituting the second surface layer of a laminated resin film which is a non-breathable film-like protective material folded in half.
  • FIG. 2 is an explanatory diagram of an example of a method for producing a half-folded non-breathable film-like protective material (winding up a half-folded film).
  • FIG. 13 is an explanatory diagram of a state in which a wound, half-folded non-breathable film-like protective material is supplied to a heat welding location.
  • FIG. 1 is a diagram explaining the supply state of a half-folded, strip-shaped, non-breathable film-like protective material, which is made of a single-layer resin film with a release paper of a predetermined width sandwiched between the inner surfaces of a pair of base fabric panels, or a laminated resin film of two or more layers including a first surface layer and a second surface layer, is continuously sandwiched along the straight or curved outer peripheral edge of the pair of base fabric panels while applying tension to the material, and then heat or ultrasound is applied from the outside of the pair of base fabric panels to weld the surface of the single-layer resin film or the first surface layer to the inner surface of the base fabric panels.
  • FIG. 1 is a diagram explaining the supply state of a half-folded, strip-shaped, non-breathable film-like protective material, which is made of a single-layer resin film with a release paper of a predetermined width sandwiched between the inner surfaces of a pair of base fabric panels, or a laminated resin film of two or more layers
  • FIG. 1 is an explanatory diagram of a method for winding a multi-layer film in a two-ply state around a 3-inch paper tube by an inflation method using a multi-layer circular die.
  • FIG. 2 is a schematic diagram of a jig (half-folding former) used to fold a film in half.
  • 1 is an explanatory diagram of an example of an airbag (cushion) including an isolated sewn portion (in the center) of a closed space.
  • 10 is an explanatory diagram of one method of adhering a folded film to an isolated sewn portion of a closed space.
  • FIG. FIG. 15 is an explanatory diagram of the sealing state according to the method 1 shown in FIG. 14 .
  • FIG. 13A and 13B are explanatory diagrams of another method for adhering a folded film to an isolated sewn portion of a closed space and a sealed state.
  • FIG. 2 is an explanatory diagram of the layer structure of a folded film in terms of the melting point difference (left side) and the interlayer SP value difference (right side).
  • An embodiment of the present invention is a method for manufacturing an airbag having at least one pair of fabric panels sewn together at a periphery thereof, the method comprising the steps of: a welding step of continuously sandwiching a semi-folded, band-shaped non-breathable film-like protective material, which is made of a monolayer resin film having a predetermined width with a release paper sandwiched therebetween or a laminated resin film having two or more layers including a first surface layer and a second surface layer, between the inner surfaces of the pair of base fabric panels while applying tension to the material along the linear or curved outer periphery of the pair of base fabric panels, and applying heat or ultrasonic waves from the outside of the pair of base fabric panels to weld a surface of the monolayer resin film or the first surface layer to the inner surface of the base fabric panel in an adhesive region of a predetermined width, wherein although the surfaces of the monolayer resin film on the release paper side are not
  • the pair of base fabric panels is not particularly limited and may be a plain weave fabric of polyamide or polyester that is normally used as a base fabric for airbags.
  • the fineness of the fibers constituting the base fabric used in this embodiment is preferably 150 to 900 dtex.
  • a fineness of 150 dtex or more can provide the strength required for an airbag, and a fineness of 900 dtex or less can provide a soft base fabric for an airbag.
  • the fiber When the fiber is in this range, it is flexible when used as a base fabric for an airbag and has a high deployment speed.
  • the weaving density of the base fabric used in this embodiment is preferably 30 to 90 threads/inch for both warp and weft, and the cover factor is preferably 1500 to 2500.
  • the base fabric panel may be coated with resin on one or both sides or laminated with a single or multi-layer film to reduce breathability.
  • the resin used for the resin coating may be a silicone or polyurethane coating, or a method of thermal lamination using a flame-retardant thermoplastic resin film, etc. may be used.
  • the coating amount is preferably 5 to 50 g/m 2.
  • the thickness of the film is preferably 0.001 mm or more and 0.5 mm or less. Within this range, a base fabric that is flexible and has excellent airtightness when used as a base fabric for an airbag can be obtained.
  • the airbag according to this embodiment can be one in which a pair of base fabric panels are sewn together at their outer periphery to form a bag, as shown in FIG. 1.
  • reference numeral 2 indicates the sewn (stitched) portion of the main panel
  • reference numeral 4' indicates the position of the inner edge (top of the loop) of a semi-folded non-breathable protective material, which is on the back side of the front base fabric panel and which will be described below.
  • an inner tube reference numeral 23
  • the stitching is not particularly limited as long as it is not broken when the airbag is inflated and deployed, but it is preferably machine-sewn with sewing thread made of multifilament fiber of the same material as the base fabric panel. As described above, in order to maintain the internal pressure, it is required that the stitching does not break when the airbag is deployed and that there is substantially no gas leakage.
  • the sewing thread may be a single twisted fiber or a multiple twisted fiber having two or more single twisted fibers twisted together, and the total fineness of the twisted fibers is preferably 700 to 2000 dtex.
  • the sewing method may be a lock stitch, a chain stitch, etc.
  • the number of stitches (stitch pitch) is preferably 30 to 60 stitches/10 cm.
  • Fig. 2 is an enlarged view of the area corresponding to the A-A cross section in Fig. 1 to prevent gas leakage at the seams, and explains the state of an airbag when it is deployed if it is sewn to the area bonded with silicone adhesive in the conventional technology.
  • silicone adhesive When silicone adhesive is used, the silicone adhesive deforms and stretches during deployment to seal in the gas, improving the internal pressure retention, but the thickness of the silicone adhesive after curing increases the thickness of the airbag after folding (when stored), making it difficult to store, and it takes a long time, from half a day to about a day, to cure, reducing the productivity of the airbag.
  • an airbag can be manufactured with high productivity in which both end outer surfaces of a folded, band-like, non-breathable film-like protective material are bonded to the inner surface of each of a pair of base fabric panels in an adhesive region of a predetermined width along the seam from the vicinity of the seam toward the inside of the bag body, the outer surfaces being bonded in a straight or curved line, the non-breathable film-like protective material being a laminated resin film of two or more layers including a first surface layer and a second surface layer, the first surface layer being welded to the base fabric panel, and the second surface layers being not bonded to each other, or being bonded to each other but causing the second surface layer to peel off when a tensile force is applied to the pair of base fabric panels when the airbag is deployed.
  • the length between the distal ends along the folded non-breathable film-like protective material is greater than or equal to the length between the distal ends along the pair of base fabric panels.
  • the manufacturing method of this embodiment can be used for the entire outer periphery of the airbag, or for a portion of the airbag.
  • a portion means, for example, 50% or more.
  • a manufacturing method using, for example, silicone adhesive for the stitching that may cause other gas leaks in the airbag can be selected in order to ensure airtightness for the entire airbag.
  • this characteristic structure can be applied to the vicinity of the stitching of any two (a pair) of base fabric panels of an airbag composed of at least two or more base fabric panels.
  • the pair of base fabric panels do not necessarily need to have the same shape, and as long as the airtightness of the adhesive area is not compromised, the pair of base fabric panels may be three-dimensionally sewn with different shapes of stitching lines.
  • an airbag formed by sewing at least one pair of fabric panels together at their outer periphery refers to an airbag in which the fabric panels are sewn together to form an inflation chamber for the airbag, and in which two or more fabric panels are sewn together at the outer periphery of the chamber. Therefore, the airbag is not limited to an airbag composed of only two fabric panels, which are made by overlapping two fabric panels of the same shape, as shown in Figures 1 and 13, and there is no limit to the number of fabric panels that make up the airbag or the overall structure of the airbag, as long as there is a portion where two or more fabric panels are joined together at the outer periphery of the chamber.
  • this broadly includes a single, line-symmetrical base fabric panel that is folded along the line of symmetry and the overlapping portions sewn together, a single, strip-shaped base fabric panel that is rolled into a tube and the overlapping portions sewn together, and three or more base fabric panels that are sewn together, that is, as long as the partial structure has a non-breathable protective material covering the sewn portions of the base fabric panels.
  • non-breathable refers to the surface property of a protective material that suppresses ventilation to a degree that does not significantly impair the airtightness of the airbag.
  • the amount of gas passing through the surface is preferably 0.5 L/ dm2 /min or less, more preferably 0.1 L/ dm2 /min or less, and even more preferably 0.05 L/ dm2 /min or less.
  • Fig. 3 illustrates the state of the semi-folded non-breathable protective material when the airbag is deployed.
  • the semi-folded non-breathable protective material presents a loop shape toward the inside of the airbag and forms an airtight structure in the bonded area with the base fabric panel, thereby exhibiting internal pressure retention.
  • the length between the distal ends along the folded non-breathable protective material is preferably greater than or equal to the length between the distal ends along a pair of base fabric panels when the airbag is deployed, thereby maintaining an airtight structure in the adhesive region.
  • the non-breathable film-like protective material has high extensibility, even if the length of the loop of the protective material before the airbag is deployed (when the airbag is housed) is approximately the same as or shorter than the adhesive distance along the base fabric panels, the non-breathable protective material is stretched by the tensile force applied when the airbag is deployed, and if the seam is destroyed first, substantially no force is applied to the adhesive region, resulting in the same result.
  • the state of the airbag when it is deployed can be simulated by, for example, using the following method. First, the stored airbag is taken out, a part of the protective material and the base fabric panel are cut, and the pair of base fabric panels are spread 180° as shown in the deployed state in Figures 4(a) and (b).
  • Figure 4(a) is the first pattern
  • Figure 4(b) is the second pattern (loop outside, film folded back and stored).
  • the length between the distal ends along the half-folded non-breathable protective material is greater than or equal to the length between the distal ends along the pair of base fabric panels, thereby maintaining an airtight structure in the adhesive region.
  • half-folded non-breathable film-like protective material includes not only a material that is half-folded when housed in an airbag, as shown in the upper part of Figures 4(a) and (b), i.e., a material made by folding a strip-shaped single-layer or multi-layer resin film or laminate base fabric in half, but also a material that is folded multiple times, such as into an accordion-like shape, or a material made by overlapping two strip-shaped (including curved) single-layer or multi-layer resin film or laminate base fabric and bonding one end with an adhesive or welding (i.e., a material made by laminating two sheets).
  • it is preferable to manufacture protective materials by continuously supplying half-folded strip-shaped films, etc., and heat welding them, as shown in Figures 8 to 10 and 12, rather than by laminating two sheets.
  • Such a band-shaped, semi-folded, non-breathable film-like protective material is adhered to the base fabric in a straight or curved manner along the seams.
  • two sheets of a band-shaped non-breathable film-like protective material are used, which are obtained by cutting a resin film into a desired shape, and the outer layers of one end (inner edge side) of the multilayer film are welded together (for example, in the case of a PE (second surface layer)-PA6/12 (first surface layer) multilayer film, a part of the second surface layer is peeled off and the first surface layers are welded together) along the inner edge so that the length from the outer edge is a predetermined length, for example, a width of 5 mm, or the sheets are bonded together with, for example, a cyanoacrylate-based instant adhesive (manufactured by Konishi Co., Ltd.) and thoroughly dried (that is, a method of bonding two protective materials cut into a base fabric panel shape (hors
  • the protective material by continuously supplying a band-shaped sheet of resin film folded in half and heat welding it while applying tension, as shown in FIGS. 8 to 10, rather than by manufacturing the protective material by a two-sheet bonding method.
  • the two-sheet lamination method requires cutting out the resin film along the sewing shape of the airbag, the use of a half-folded belt-shaped resin film can maximize the efficiency of film utilization, and can increase productivity because there is no need to bond the films together.
  • the non-breathable film-like protective material there are no particular limitations on the non-breathable film-like protective material, so long as it is not destroyed when the airbag is inflated and deployed, and single-layer or multi-layer resin films can be used. From the viewpoint of reducing the weight and compactness (ease of folding and storage) of the airbag, it is preferable to use single-layer or multi-layer resin films as the non-breathable protective material.
  • the adhesive strength can be increased by bonding the same type of single-layer or multi-layer resin film to a laminated base fabric panel, thereby improving the internal pressure retention of the airbag.
  • the same type of single-layer or multi-layer resin film (and substrate) used in the non-breathable protective material and the base fabric panel recyclability can be improved.
  • the term “bonding” includes bonding with an adhesive and welding with ultrasonic waves or heat.
  • the base fabric panel and the protective material can be bonded together by welding using heat or ultrasonic waves to form a bonded area that will not peel off even when the airbag is deployed and can maintain airtightness. Welding without using adhesives is preferable from the standpoint of thickness after folding, productivity, recycling, etc.
  • the term "bonded area (5, 5')" has a proximal end (6, 6') and a distal end (7, 7') with respect to the seam (2), respectively.
  • the proximal end (6, 6') may be located on the inside of the airbag from the seam (2) or on the outside of the airbag. In the latter case, the bonded area will extend to the seam allowance.
  • the loop structure of the non-breathable protective material folded in half in the adhesive region may be arranged so as to face the outer edge of the airbag (outside of the airbag).
  • the half-folded non-breathable protective material has a loop shape toward the inside of the airbag, and the length between the distal ends along the half-folded non-breathable protective material is greater than the length between the distal ends along a pair of base fabric panels, so that an airtight structure can be formed in the adhesive region with the base fabric panels as in the case of Fig. 4(a).
  • the loop structure of the non-breathable protective material in order to prevent the part that contributes to maintaining the internal pressure of the protective material from being damaged by sewing, it is preferable to arrange the loop structure of the non-breathable protective material so as to face the inside of the airbag.
  • the "bonded region" need only be bonded in such a way that it will not be destroyed or peeled off when the airbag inflates and deploys, and that it maintains airtightness and internal pressure retention.
  • the thickness of the non-breathable film-like protective material is preferably 0.001 mm or more and 0.5 mm or less, and more preferably 0.001 mm or more and 0.1 mm or less, from the viewpoint of the folded thickness.
  • the adhesive strength (peel strength) in the adhesive region between the base fabric panel and the non-breathable film-like protective material is preferably 1 N/cm or more, and more preferably 3 N/cm or more, from the viewpoint of airtightness. If the adhesive strength is 3 N/cm or more, the occurrence of leaks caused by the film peeling off from the panel base fabric due to the wind pressure of the gas when the airbag is deployed is significantly reduced.
  • the tensile modulus of the semi-folded band-shaped non-breathable protective material is preferably 100 to 800 MPa in both MD (machine direction) and TD (transverse direction), more preferably 150 to 600 MPa, and even more preferably 200 to 500 MPa.
  • the tensile modulus of the film referred to here is the measurement result when the band-shaped non-breathable film-like protective material is opened from the half-folded state and pulled.
  • the above tensile modulus (flexibility) makes it easy to form a curved structure to follow the curved parts (including R parts and reverse R parts) that are usually used in the main fabric of an airbag.
  • the film has good handleability (balance between ease of deformation at curved parts and handling of the film) due to moderate flexibility.
  • the tensile breaking strength of the film is preferably 10 to 100 MPa in both MD and TD from the viewpoint of durability, more preferably 15 to 80 MPa, and even more preferably 20 to 60 MPa.
  • the airbag of this embodiment may have, in the adhesive region, an R portion with a curvature radius of 300 mm or less and/or an inverse R portion with a curvature radius of 300 mm or less, as shown in FIG. 1 and FIG.
  • the R portion is a portion of the seam line along the outer periphery of the base fabric panel that is curved convexly toward the side other than the inflatable portion (chamber) of the airbag.
  • the X portion in FIG. 1 corresponds to this.
  • the reverse R portion is a portion of the seam line along the outer periphery of the base fabric panel that is curved convexly toward the inflatable portion (chamber) of the airbag.
  • the degree of wrinkles when the non-breathable protective material is adhered can be confirmed by measuring the step (peak-valley difference) between the wrinkled portion and the normal portion.
  • the step (peak-valley difference) between the wrinkled portion and the normal portion of such R portion is preferably 400 ⁇ m or less, more preferably 300 ⁇ m or less, even more preferably 200 ⁇ m or less, and even more preferably 100 ⁇ m or less.
  • the step between the wrinkled portion and the normal portion can be made small, thereby preventing stress concentration, suppressing gas leakage from the adhesive portion, and resulting in an airbag with excellent storage properties.
  • the ratio (R portion/straight portion) of the step (peak-valley difference) between the wrinkled portion and the normal portion of the R portion to the step (peak-valley difference) between the wrinkled portion and the normal portion of the approximately straight portion excluding the R portion is preferably 0.6 to 2.0, and more preferably 0.8 to 1.5.
  • the wrinkle step measurement was performed using a surface roughness measuring instrument (SURFTEST EXTREME SV-3000CNC) manufactured by Mitutoyo Corporation, and the wrinkled area and the surrounding normal area were measured in three-dimensional mode under the following measurement conditions.
  • An arbitrary cross-section extraction function was used in the obtained three-dimensional image to extract a cross-section that included the largest step area, and a baseline was drawn on the extracted cross-section (two-dimensional) connecting the start point and end point of the wrinkled area (step), and the maximum height from the baseline was determined.
  • a multilayer resin film is used as the half-folded belt-shaped protective material, and a release paper is not used, and the second surface layers on the inside of the loop are not bonded to each other or are welded by heat welding or ultrasonic welding, but when a tensile force is applied to the pair of base fabric panels when the airbag is deployed, the second surface layers are peeled off, which improves the productivity of the airbag in that the process of inserting and/or removing the release paper is not required, the consideration of the material and physical properties of the release paper and its handling are not required, and the tension can be easily adjusted.
  • Such a configuration can be achieved, for example, by setting the melting point of the resin constituting the first surface layer of the laminated resin film, which is a non-breathable film-like protective material folded in half, to be 50°C to 160°C, and preferably 60°C to 160°C, lower than the melting point of the resin constituting the second surface layer, so that the second surface layers on the inside of the loop are not welded to each other, or by setting the difference in SP value of the resin constituting the first surface layer, the resin constituting the second surface layer, and the resin constituting the other layer of the laminated resin film, which is a non-breathable film-like protective material folded in half, to be 2.0 [cal/ cm3 ) 1/2 ] or more between adjacent layers, so that delamination occurs between any of the layers, or the second surface layer delaminates from an adjacent layer.
  • the difference in SP value between any adjacent layers is preferably 2.0 [cal/ cm3 ) 1/2 ] or more, more preferably 2.5 [cal/ cm3 ) 1/2 ] or more, even more preferably 3.0 [cal/ cm3 ) 1/2 ] or more, and even more preferably 4.0 [cal/ cm3 ) 1/2 ] or more.
  • the melting point of PA6/12 is 128°C
  • that of TPEE is 216°C
  • that of PA6/66 is 194°C
  • that of PA12 elastomer is 176°C
  • that of PO acid-modified polyethylene
  • that of PE LDPE
  • the difference in melting point between the resin constituting the first surface layer and the resin constituting the second surface layer can be made 50°C or more.
  • the preferred range of the melting point difference is 50°C to 160°C, more preferably 60°C to 160°C, and even more preferably 80°C to 160°C.
  • the adhesive strength with the base fabric panel can be increased and the range of adhesion temperatures at which fusion between the second surfaces can be made difficult to occur can be widened, improving production stability.
  • the melting point difference 160°C or less for example, when producing a film by inflation molding, flow unevenness and melt tension are appropriately maintained, improving film formation stability.
  • the melting point of the resin constituting the protective material is preferably 90° C. or higher, more preferably 100° C. or higher, and even more preferably 110° C. or higher. By making the melting point 90° C. or higher, sufficient adhesive strength can be maintained even when the temperature inside the vehicle becomes high.
  • the SP value of PE is 8.1 [cal/cm 3 ) 1/2
  • the SP value of PA6/66 is 13.6 [cal/cm 3 ) 1/2
  • the SP value of PA6/12 is 13.6 [cal/cm 3 ) 1/2
  • the SP value of PET is 10.7 [cal/cm 3 ) 1/2 ]
  • PE (second surface layer)-PA6/66 release layer side of the first surface layer, which is a multilayer film)
  • PE (second surface layer, release layer)-PET (first surface layer) is used as the protective material
  • the difference in SP value with the PA base fabric or PET base fabric, respectively can be made 2.0 [cal/cm 3 ) 1/2 ] or more.
  • the first surface layer (fabric panel side) can be considered to be composed of an adhesive layer (PA6/12), while the second surface layer (inside the loop) can be considered to be composed of four layers including a release layer (PE), an intermediate layer (acid-modified PE), and a high melting point layer (PA6/66).
  • PA6/12 adhesive layer
  • PA6/12 adhesive layer
  • PA6/66 high melting point layer
  • the release effect can be achieved not only when the SP value difference between the high melting point layer (PA6/66) and the release layer (PE) is greater than or equal to 2.0 [cal/cm3)1/2], but also when the SP value difference between any of the adjacent layers constituting the first surface layer, the adhesive layer (PA6/12), the X layer (e.g., the intermediate layer (acid-modified PE)), and the high melting point layer (PA6/66), is greater than or equal to 2.0 [cal/ cm3 ) 1/2 .
  • the above-mentioned configuration based on the SP value difference is preferable to the above-mentioned configuration based on the melting point difference.
  • the reason for this is that the fusion (processing) temperature can be raised above the melting point of the film, making it possible to strengthen the adhesion between the base fabric panel and the film, and by increasing the processing speed, productivity can be improved.
  • the SP value (Hildebrand solubility parameter) is a physical property defined as the square root of the cohesive energy density, and indicates the solubility behavior of a solvent. Therefore, the inventors of this application used combinations with large differences in SP value as indicators for selecting the release layer.
  • the SP values of various resins are listed, for example, in "Guide to Various Standards and Usage: Plastic Material Test Methods, Comparisons, Evaluations, and Results” p. 32 (2nd edition, May 10, 2011) by Sangyo Gijutsu Center Co., Ltd., and a reference for calculating the SP value is "Practical Polymers for Engineers" by Kodansha, August 1, 1989.
  • HSP Hansen solubility parameter
  • the HSP value is also shown in the examples, but the peeling effect can be achieved by making the HSP value difference 1.0 (cal/ cm3 ) 1/2 or more.
  • HSP is a predicted value by Winmostar (V9.3.0) manufactured by CrossAbility Co., Ltd., and is calculated by the dispersion term ( ⁇ D), polarization term ( ⁇ P), and hydrogen bond term ( ⁇ H) between certain substances.
  • the HSP calculation for the copolymer composition is a value obtained by calculating the HSP of each homopolymer and multiplying it by the composition ratio (volume ratio) to obtain a total value.
  • the glass transition temperature (Tg) of the second surface layer (inside of the loop) is preferably 0°C or higher, more preferably 20°C or higher, and even more preferably 30°C or higher.
  • the upper limit of the glass transition temperature is 80°C or lower, more preferably 70°C or lower, and even more preferably 60°C or lower.
  • An airbag in which a pair of base fabric panels are sewn together at their outer periphery to form a bag body, An airbag can be provided with high productivity in which both end outer surfaces of a folded, band-like, non-breathable film-like protective material are bonded to the inner surface of each of the pair of base fabric panels in an adhesive region of a predetermined width along the seam from near the seam toward the inside of the bag body, the outer surfaces being bonded in a straight or curved line, the folded, non-breathable film-like protective material being a laminated resin film of two or more layers including a first surface layer and a second surface layer, the first surface layer being welded to the base fabric panel, and the second surface layers being not bonded to each other, or being bonded to each other but causing the second surface layer to peel off when a tensile force is applied to the pair of base fabric panels when the airbag is deployed.
  • the tensile modulus of the film is preferably 100 to 800 MPa in both MD (machine direction) and TD (transverse direction), more preferably 150 to 600 MPa, and even more preferably 200 to 500 MPa.
  • the tensile modulus of the film referred to here is the measurement result when the band-shaped non-air-permeable and breathable film-like protective material is opened from a half-folded state and pulled.
  • the above tensile modulus (flexibility) makes it easy to form a curved structure that fits the curved part that is usually used in the main fabric of an airbag.
  • the tensile modulus By setting the tensile modulus to 100 to 800 MPa, the film has a moderate flexibility and good handleability (balance between ease of deformation at curved parts and handling of the film).
  • the tensile breaking strength of the film is preferably 10 to 100 MPa in both MD and TD from the viewpoint of durability, more preferably 15 to 80 MPa, and even more preferably 20 to 60 MPa.
  • the tensile breaking strength is 100 MPa or less, the rigidity is suppressed and the film has good handling properties. Furthermore, when the band-shaped non-permeable and breathable film-like protective material is deformed to follow the curved outer peripheral edge by applying tension, it is preferable to use a thermoplastic resin film, since the film can be easily stretched by applying heat.
  • methods for sandwiching a strip-shaped non-breathable film-like protective material along the straight or curved outer peripheral edges of a pair of base fabric panels include a method of preparing a roll of half-folded film in advance and feeding the strip-shaped non-breathable film-like protective material from the wound roll to the welding point by heat welding or ultrasonic welding, as exemplified in Figures 8 to 10, a method of preparing a roll of the half-folded strip-shaped non-breathable film-like protective material in an unfolded state and feeding the strip-shaped non-breathable film-like protective material from the wound roll to the welding point by heat welding or ultrasonic welding, folding it in half during the process of feeding it to the welding point by heat welding or ultrasonic welding, and then feeding it to the welding point, and a method of folding in half a strip-shaped non-breathable film-like protective material that has been cut in advance to the length of the straight or curved outer peripheral edges of a pair of base fabric panels, and feeding it to the welding point
  • the pleats in the folded portion can be firmly fixed, and by continuously feeding the film from the wound roll, the folded portion of the film is less likely to shift, and warping (curling) of the folded film is suppressed (as the film structure is symmetrical between the top and bottom), which is expected to have the further effect of suppressing the occurrence of wrinkles (improving quality).
  • the method of applying tension to the half-folded film is not particularly limited, but for example, as shown in Figure 17, a method can be used in which the tape is held down with one hand and the base fabric with the other while the tape is pulled while adjusting the tension applied to it so that it conforms to the shape of the outer periphery of the airbag.
  • a roll of half-folded film may be prepared in advance, and a tension control mechanism may be provided during the process of sending the band-shaped non-breathable film-like protective material from the roll to the welding location by heat welding or ultrasonic welding.
  • the base fabric is sandwiched between upper and lower conveyor belts at the welding location, and while the base fabric is transported by the conveyor belt, it is sandwiched between upper and lower hot plates and heat is applied, so that continuous welding can be performed.
  • the tape (sandwiched between the base fabrics) is in a heated state, and the tape is stretched to fit the shape of the outer periphery of the airbag by applying tension, so that the non-air-permeable and breathable film-like protective material can be bonded without wrinkles even in curved parts including R parts and reverse R parts.
  • a part or the whole of the non-air-permeable and breathable film-like protective material can be preheated by a method such as a hot plate or hot air, so that the tape can be easily stretched to fit the shape of the outer periphery of the airbag.
  • a cooling section using a cooling plate may be provided immediately after welding.
  • the adhesiveness of the non-permeable, breathable film-like protective material is improved.
  • the welding workability of the curved section can be improved.
  • the method of continuously sandwiching the half-folded film (tape) along the straight or curved outer periphery of the pair of base fabric panels while applying tension to the film and applying heat or ultrasonic waves from the outside of the pair of base fabric panels to bond the panels together may lead to misalignment of the base fabrics, as the upper and lower base fabrics are bonded together continuously and simultaneously. Also, in the final stages of bonding or depending on the sewing shape of the airbag, there may be a small space, which may make it difficult to insert the tape under the upper base fabric.
  • the following two-step method may be used, in which, rather than clamping the tape between a pair of base fabric panels, one side of the tape is adhered to the first piece of base fabric (1st step), and then a second piece of base fabric is placed on top of the tape and compressed (2nd step).
  • the tape is fed onto one base fabric panel while applying tension, and then the tape is welded onto the first base fabric by heating from below, fixing the tape onto the one base fabric panel without wrinkles (1st step).
  • a second base fabric is then placed on top of the tape, and pressure is applied by heating using thermal welding or ultrasonic welding (2nd step). This eliminates the need to simultaneously operate the upper and lower base fabrics as described above, and only one base fabric is operated, and because the tape is not sandwiched between the base fabrics, there is no problem with the space becoming narrow at the final stage of bonding, etc.
  • the method of applying tension to the tape is not particularly limited, and a method of pulling the tape while adjusting the tension applied to it so that it conforms to the shape of the outer periphery of the airbag can be used, similar to the above-mentioned tension application and clamping method, while holding the tape with one hand and the base fabric with the other hand.
  • a roll of half-folded film may be prepared in advance, and a tension control mechanism may be provided in the process of sending the band-shaped non-breathable film-like protective material from the roll to the welding point by thermal welding or ultrasonic welding.
  • the tape can be welded onto the first base fabric by a hot plate from below the belt heat pressing machine, while the tape is heated by the upper hot plate to assist in stretching the tape in the R and reverse R sections.
  • the method for placing a second base fabric on the tape and heating it by thermal welding or ultrasonic welding is not particularly limited, and it may be continuously welded using a belt heat pressing machine as in the first step, or it may be welded all at once using a heat press machine that can heat the welded parts simultaneously, but from the viewpoint of productivity, it is preferable to use a heat press machine that can heat the welded parts simultaneously.
  • the first step is expected to have the secondary effect of improving the processing speed by temporarily fixing the parts.
  • the airbag is sealed by the adhesive area in both A-A'section and C-C'section.
  • the half-folded band-shaped non-breathable protective material is adhered to the inner surface of each of the pair of base fabric panels in an overlapping manner, and the end of the non-breathable protective material may be sealed.
  • the non-breathable protective material is "adhered to the overlapping manner" means that a plurality of the non-breathable protective materials are arranged in an overlapping manner, the non-breathable protective materials are adhered to each other, and the non-breathable protective material closest to the base fabric panel is adhered to the inner surface of each of the pair of base fabric panels.
  • the non-breathable protective materials may be overlapped at the same sewing portion and adhered to each other, or in a sewing shape having a branch point, a half-folded band-shaped non-breathable protective material arranged near one sewing line and a half-folded band-shaped non-breathable protective material arranged near the other sewing line may be partially overlapped and adhered near the sewing branch point.
  • the multiple non-breathable protective materials are united to form a loop-shaped structure bonded to the inner surface of each of the base fabric panels, and when a tensile force is applied between the pair of base fabric panels, a state can be formed in which the length between the distal ends along the folded non-breathable protective materials is greater than or equal to the length between the distal ends along the pair of base fabric panels.
  • the term "sealed end portions" of the non-breathable protective material refers to a state in which the end portions of the plurality of non-breathable protective materials are not open to the inflatable portion (chamber) of the airbag.
  • the method for sealing the end portions of the non-breathable protective materials is not particularly limited, and may be adhesion with an adhesive, heat welding, ultrasonic welding, or folding the non-breathable protective material. Also, as shown in FIG. 16, a structure in which the end portions are exposed to the outside of the inflatable portion (chamber) may be used.
  • This manufacturing method can be used as a method for intentionally providing a joint portion of a band-shaped non-breathable protective material folded in half when welding a band-shaped non-breathable protective material folded in half near a sewing shape having a branch point or a bent sewing shape, when the airbag size is large and the process is divided from the viewpoint of workability, etc.
  • the tension application or clamping method it can be widely applied to the 2-step method, the two-sheet bonding method, etc.
  • Si-coated fabric used as the base fabric panel and/or protective material was a plain weave fabric woven using nylon 66 multifilament fibers as the warp and weft, with one side coated with silicone resin.
  • the total fineness of the weaving yarn constituting the base fabric was 470 dtex, the number of filaments was 136, the weaving density of the coated fabric was 49/inch (2.54 cm), and the amount of silicone resin coated was 25 g/ m2 .
  • a film to be used as a protective material was prepared as follows. As shown in Fig. 11, a multilayer circular die was used to wind a desired multilayer film in a two-ply state around a 3-inch paper tube by the inflation method. At this time, the film was formed so that the inner surface side 3b of the tubular film was the adhesive layer and the outer surface side 3a was the outer layer.
  • the tensile elongation at break of the film is the measurement result when a band-shaped non-permeable and breathable film-like protective material is opened from a half-folded state and pulled. If the length of the measurement sample is short and the chuck distance cannot be satisfied, the chuck distance may be narrowed. In this case, a tensile speed at which the strain rate is 100%/min is selected.
  • the obtained film was cut along the MD direction to make a strip film 40 mm wide, and wound into a roll.
  • the upper heater temperature of the belt thermocompression machine was set to 100°C
  • the lower heater temperature was 230°C
  • the feed speed was set to 1.0 m/min
  • the entire film was heated to 100°C on one main panel using a Ryobi hot air gun (HAG-1551), and the tape was fed out while applying tension, and the tape was welded onto the first base fabric by heating from below (step 1).
  • a second base fabric was placed on top of the tape, and the tape was pressed for 3 seconds at a pressure temperature of 190°C using a hot plate jig having a shape that matches the bonded portion in step 1 (step 2).
  • Comparative Example 1 Preparation of a belt-shaped folded film (room temperature fixing method)
  • the coated fabric or laminate base fabric previously folded in half was wound into a roll, and a length equal to the sewing length of the outer edge of the airbag was cut and used.
  • the internal pressure of the airbag 6 seconds after the solenoid valve was opened was divided by the maximum internal pressure of the airbag after the solenoid valve was opened, and the value was recorded.
  • the test was performed once for each of the three airbags, and the average of the three measurements was calculated as the internal pressure retention rate after 6 seconds, expressed as a percentage.
  • the tensile modulus of the film referred to here was the measurement result when a strip-shaped non-permeable and breathable film-like protective material was opened from a half-folded state and pulled.
  • the chuck distance may be narrowed. In this case, a tensile speed at which the strain rate is 5%/min is selected.
  • Manufacturing time per bag The time required from the process of cutting sample pieces from the sample fabric to the production of three bags sewn according to each specification described below was divided by 3 to obtain the manufacturing time per bag, which was expressed as an index with Example 1 set as the standard of 100. However, the process of producing the protective material was carried out and prepared in advance.
  • the protective material used had a layer structure of "adhesive layer/intermediate layer/resin layer 1/resin layer 2", and was a multilayer film made of PA6/12 for the adhesive layer, POm-PE for the intermediate layer, PA6/66 polymer for resin layer 1, and PE (LDPE) for resin layer 2, which were extruded from a multilayer circular die and made into a 30 ⁇ m-thick four-type four-layer film by the inflation method.
  • LDPE PE
  • the layer structure of the protective material used was a multilayer film consisting of "adhesive layer/resin layer 1/intermediate layer/resin layer 1/resin layer 2/resin layer 3", in which PA6/12 was used for the adhesive layer, PO for resin layer 1, PO elastomer for the intermediate layer, PA6/66 polymer for resin layer 2, and PE (LDPE) for resin layer 3, and the film was extruded from a multilayer circular die and made into a 5-type 6-layer film with a thickness of 30 ⁇ m by the inflation method.
  • the layer structure of the protective material used was a multilayer film consisting of "adhesive layer/intermediate layer/resin layer 1", with PA6/66 polymer used for the adhesive layer, POm-PE for the intermediate layer, and PA6/66 polymer used for the resin layer 1, which were extruded from a multilayer circular die and made into a 30 ⁇ m thick two-kind three-layer film by the inflation method.
  • the physical properties of the multilayer films obtained and the evaluation results of airbag test pieces using these films as protective materials are shown in Table 1 below.
  • Example 1 a four-type, four-layer multilayer resin film was used as the non-breathable film-like protective material.
  • the elastic modulus of this film in the MD direction was 245 MPa
  • the elastic modulus in the TD direction was 250 MPa.
  • the method of sandwiching the band-shaped non-breathable film-like protective material along the straight or curved outer periphery of a pair of base fabric panels was to prepare a roll of half-folded film in advance, and send the band-shaped non-breathable film-like protective material from the roll to the welding point by heat welding. This method allowed for good handling during processing of the R section, and the obtained airbag had a high internal pressure retention rate and good compactness.
  • Example 2 was the same as Example 1, except that the elastic modulus of the film in the MD direction was 200 MPa and the elastic modulus in the TD direction was 200 MPa. This method provided excellent handling during processing of the R section, and the airbag obtained had a high internal pressure retention rate and good compactness.
  • Example 3 was the same as Example 1, except that the elastic modulus of the film in the MD direction was 300 MPa and the elastic modulus in the TD direction was 290 MPa. With this method, the film was somewhat hard and difficult to deform, which slightly worsened the handling properties during processing of the R section, but the airbag obtained had a high internal pressure retention rate and good compactness.
  • Example 4 was the same as Example 1, except that the elastic modulus of the film in the MD direction was 150 MPa and the elastic modulus in the TD direction was 125 MPa. With this method, the film was soft and sometimes difficult to handle, and the handling properties during processing of the R section were slightly worse, but the airbag obtained had a high internal pressure retention rate and good compactness.
  • Example 5 a two-type, three-layer multilayer resin film was used as the non-breathable film-like protective material.
  • a roll of half-folded film was prepared in advance to sandwich the band-shaped non-breathable film-like protective material along the straight or curved outer periphery of a pair of base fabric panels, and a 20 mm wide PE film (thickness 50 ⁇ m) was sandwiched inside the fold of the half-folded film as a release paper.
  • the band-shaped non-breathable film-like protective material was sent from the roll to the welding point by heat welding. With this method, the release paper may be misaligned, making it difficult to handle, and the handling during processing of the R section was slightly deteriorated, but the obtained airbag had a high internal pressure retention rate and good compactness.
  • Example 6 the same film as in Example 5 was used, but a roll of strip-shaped film was prepared in advance without being folded in half, and a strip-shaped non-breathable film-like protective material was folded in half using a half-folding former in the process of sending it from the roll to the welding point by heat welding, and then a 20 mm wide PE film (thickness 50 ⁇ m) was sandwiched as release paper inside the fold of the half-folded film and sent to the welding point.
  • the release paper and film were prone to shifting, making them difficult to handle, and handling during processing of the R section was impaired, but the resulting airbag had a high internal airbag pressure retention rate and good compactness.
  • Example 7 the same film as in Example 1 was used, but a roll of strip-shaped film was prepared in advance without being folded in half, and in the process of sending the strip-shaped non-breathable film-like protective material from the roll to the welding location by heat welding, the material was folded in half using a half-folding former, and then sent to the welding location.
  • the film was prone to shifting and curling, making it difficult to handle, and the handling properties during processing of the R section were somewhat worse, but the resulting airbag had a high internal airbag pressure retention rate and good compactness.
  • Example 8 the same film as in Example 1 was used, but when making the airbag, instead of sandwiching a strip-shaped non-air-permeable, breathable film-like protective material along the straight or curved outer periphery of a pair of base fabric panels, a tape was fed onto one main panel while applying tension, and the tape was welded onto the first base fabric by heating from below (step 1). After that, a second base fabric was placed on top of the tape and pressed onto it (step 2). This method allowed for good handling during processing of the R-section, the manufacturing time per bag was short, and the resulting airbag had a high airbag internal pressure retention rate and good compactness.
  • Comparative Example 1 the same film as in Example 1 was used, but when the airbag was made, the film-like protective material was sandwiched between two panels of cloth so as to form a loop on the inside of the airbag, and the panels of cloth were sewn together, and then the protective material and the laminated surface of the panel cloth were heat-sealed inside the stitching. Because the protective material was fixed by sewing when bonding, it was bonded without applying tension to the protective material. With this method, the film was prone to shifting and wrinkling, which could make it difficult to handle, and the handling during processing of the R section was poor. In addition, the manufacturing time per bag was long, and the resulting airbag had a low internal pressure retention rate and was not very compact.
  • the method for manufacturing an airbag according to the present invention comprises bonding the outer surfaces of both ends of a folded, strip-shaped, non-breathable protective material to the inner surface of each of at least a pair of base fabric panels in bonding regions of a predetermined width along the seams from near the seams toward the inside of the bag, the bonding regions having proximal and distal ends.
  • This method is highly productive for producing an airbag which has high internal pressure retention performance, is low cost, has high productivity, and is also highly compact. Therefore, the airbag manufacturing method according to the present invention can be suitably used for automobile airbags, CABs and pedestrian airbags which particularly require high internal pressure retention performance.
  • Base fabric panel (panel fabric, main panel) 1' Base fabric panel (panel fabric, main panel) Reference Signs List 2: Sewn (stitched) portion 2': Isolated sewn (stitched) portion 3: Silicone adhesive 4: Non-breathable (film-like) protective material 4': Inner edge of non-breathable (film-like) protective material 4": Half-folded strip-shaped non-breathable (film-like) protective material 5: Adhesive area 5': Adhesive area 6: Proximal end of adhesive area 6': Proximal end of adhesive area 7: Distal end of adhesive area 7': Distal end of adhesive area 8: End (sealed) portion of non-breathable (film-like) protective material 8': End (sealed) portion of non-breathable (film-like) protective material 10: Bag-shaped airbag with outer edge sewn A-A: Cross section 11: Multilayer film 11a: Multilayer film (outer layer) 11b Multilayer film (adhesive layer) 12 Multi-layer

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Air Bags (AREA)
PCT/JP2023/042592 2022-11-29 2023-11-28 内圧保持性能を高めたエアバッグの製法 Ceased WO2024117138A1 (ja)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2024561517A JPWO2024117138A1 (https=) 2022-11-29 2023-11-28

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2022-190334 2022-11-29
JP2022190334 2022-11-29

Publications (1)

Publication Number Publication Date
WO2024117138A1 true WO2024117138A1 (ja) 2024-06-06

Family

ID=91324105

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2023/042592 Ceased WO2024117138A1 (ja) 2022-11-29 2023-11-28 内圧保持性能を高めたエアバッグの製法

Country Status (2)

Country Link
JP (1) JPWO2024117138A1 (https=)
WO (1) WO2024117138A1 (https=)

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6435553B1 (en) * 2000-03-20 2002-08-20 Breed Automotive Technology, Inc. Air bag and method of seam assembly for minimizing gas leakage
JP2003514144A (ja) * 1999-11-17 2003-04-15 ミリケン・アンド・カンパニー 剥離継目を有する膨張式織物
JP2007223373A (ja) * 2006-02-21 2007-09-06 Nippon Plast Co Ltd エアバッグ及びエアバッグの製造方法
WO2010122852A1 (ja) * 2009-04-23 2010-10-28 芦森工業株式会社 エアバッグ装置
JP2015515942A (ja) * 2012-05-03 2015-06-04 ティーケー ホールディングス インク．Ｔｋ Ｈｏｌｄｉｎｇｓ Ｉｎｃ． 軽量エアバッグクッションを有するエアバッグモジュール

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2003514144A (ja) * 1999-11-17 2003-04-15 ミリケン・アンド・カンパニー 剥離継目を有する膨張式織物
US6435553B1 (en) * 2000-03-20 2002-08-20 Breed Automotive Technology, Inc. Air bag and method of seam assembly for minimizing gas leakage
JP2007223373A (ja) * 2006-02-21 2007-09-06 Nippon Plast Co Ltd エアバッグ及びエアバッグの製造方法
WO2010122852A1 (ja) * 2009-04-23 2010-10-28 芦森工業株式会社 エアバッグ装置
JP2015515942A (ja) * 2012-05-03 2015-06-04 ティーケー ホールディングス インク．Ｔｋ Ｈｏｌｄｉｎｇｓ Ｉｎｃ． 軽量エアバッグクッションを有するエアバッグモジュール

Also Published As

Publication number Publication date
JPWO2024117138A1 (https=) 2024-06-06

Similar Documents

Publication Publication Date Title
JP5201090B2 (ja) エアバッグ
JP4084198B2 (ja) 低透過性エアバッグ、及び該製造方法
US6607797B1 (en) Textile gas bag material, a protective cushion for an occupant restraint system and a method for producing the textile gas bag material
JP3731266B2 (ja) 側部用エアバッグの製造方法
JP2013067385A (ja) 熱可塑性コーティングされた熱融着式エアバッグ
PL178877B1 (pl) Worek z tkaniny polimerowej, zwłaszcza tkaniny poliolefinowej i sposób wytwarzania worka z tkaniny polimerowej, zwłaszcza tkaniny poliolefinowej
EP1161361A1 (en) Inflatable cushion
US20060292949A1 (en) Sealing and reinforcing strips principally for airbag assembly joints
US20060192373A1 (en) Vehicle air bag constructed from a composite film
CA2706934C (en) Reinforced bonded constructs
JP3875995B2 (ja) 膨脹式ガスバッグおよびその製造法
US7934750B2 (en) Airbag
WO2024117138A1 (ja) 内圧保持性能を高めたエアバッグの製法
JP7846250B2 (ja) 内圧保持性能を高めたエアバッグ及びその製法
WO2024117134A1 (ja) 内圧保持性能を高めたエアバッグ
JPH037337A (ja) エアーバック用基布およびエアーバック
JP4972659B2 (ja) 裁断、縫合し且つ積層した拡張可能な乗物の搭乗者保護装置の構造
US20090179409A1 (en) Cut, sewn, and laminated inflatable vehicle occupant protection device construction
JPH1086776A (ja) 自動車用エアバッグおよびその製法
EP2689974B1 (en) Method for producing a vehicle air-bag
JPH08104194A (ja) エアバッグ
JP7152011B2 (ja) 複合シート及びエアバッグ
JPH09164890A (ja) エアバッグ
JPH09164893A (ja) エアバッグおよびその製造方法
JPH03112746A (ja) エアバッグキヤンバスの製造方法

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 23897786

Country of ref document: EP

Kind code of ref document: A1

WWE Wipo information: entry into national phase

Ref document number: 2024561517

Country of ref document: JP

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 23897786

Country of ref document: EP

Kind code of ref document: A1