JP2011005879A - Airbag - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an airbag having a reduced weight and improved storage characteristics by reducing the amount of an adhesive seal material, while actualizing stable performance without any gas leakage.SOLUTION: The airbag includes two panels joined together with the room-temperature curable adhesive seal material. The adhesive seal material satisfies an expression; H/H≥0.8, where His a thickness of the adhesive seal material right after discharged from a circular nozzle under conditions at 25°C and imparted to a substrate, and His a thickness of the adhesive seal material when left for ten minutes after imparted, and further satisfies an expression; H/H≥0.8, where His a predetermined thickness of the adhesive seal material when pressed against another base cloth put thereon, and His a thickness of the adhesive seal material after curing. A width Wand a thickness Hof the adhesive seal material after curing while being held between the two panels satisfy expressions; H≥1.0 (mm) and W/H≤7.

Description

  The present invention relates to an airbag that is mounted on a vehicle or the like and protects an occupant from an impact such as a collision or rollover. More specifically, the present invention relates to an airbag that has excellent airtightness over a long period of time, is lightweight, and has excellent cost and productivity.

  It has been a long time since a vehicle seat airbag, a passenger seat airbag, a passenger seat airbag, and a rear seat airbag have been installed as vehicle airbags. In recent years, the use of side airbags and curtain airbags corresponding to side collisions has increased. Among these, curtain airbags corresponding to vehicle rollovers have attracted attention, which includes maintaining internal pressure to absorb the impact on the occupant's head for several seconds while the vehicle rolls over. It has been demanded. In order to cope with airbags of these various forms and required performances, airbags have been developed that can increase airtightness and extend the duration of inflation.

The curtain airbag formed by stitching usually uses an elastic adhesive seal material in combination because gas leaks from the seam portion.
Such an elastic adhesive seal material used for preventing gas leakage is ideally only around the stitched portion, and it is desired to reduce the amount and application width as much as possible. When the coating width increases, the amount of adhesive seal material to be used increases, which increases the material cost and affects the bag storage and deployment capacity. Furthermore, if the cut shape of the woven fabric is increased in consideration of the coating width, the material cost of the woven fabric increases, which is not desirable.
However, if the amount of the adhesive sealant is reduced, the application width can be reduced, but at the same time, the thickness of the adhesive sealant is reduced. In this case, it cannot withstand the pressure of the gas generated from the inflator when the airbag is inflated, and the sewn part cannot be protected by peeling from the woven fabric, and the initial gas leak prevention purpose cannot be achieved. Gas leaks are a very serious problem for curtain airbags that require long-term internal pressure retention.
If the thickness of the adhesive seal material is increased, the seal width must be increased accordingly, and the application amount cannot be reduced. Therefore, it has been difficult to reduce the amount of use of the adhesive seal material and the seal width and to secure a thickness that satisfies the performance.

  Patent Document 1 describes that by using a room temperature curable adhesive sealing material having a thixotropy index at 25 ° C. of 1.5 to 6, an adhesive bag with less deformation of the adhesive sealing material and high dimensional accuracy is obtained. Has been. However, even if the thixotropy index is in a specific range, if the adhesive sealing material has a certain thickness, the sagging during the curing reaction cannot be suppressed, and variations occur.

In Patent Document 2, the edges of two panels made of woven fabric or the like having a silicone-based sealing coating are bonded to each other by bonding with an elastic adhesive and stitching with a thread. An airbag that prevents gas leakage is disclosed. However, it only describes that the adhesive is applied at a width of 5 to 15 mm and an application amount of about 0.01 to 0.05 g / cm ² , and the thickness is not disclosed. Furthermore, no consideration is given to the sagging of the adhesive during the curing reaction, and of course there is no disclosure or suggestion of suppressing sagging.

  Further, Patent Documents 3 and 4 also describe the adhesive application thickness, width, application amount, etc., but the sagging of the adhesive during the curing reaction is not taken into account, and of course the sagging is suppressed. There is no disclosure or suggestion.

JP 2007-38694 A JP 2001-1854 A JP 2002-166806 A JP 2006-327521 A

  The present invention has been made in view of the current situation, and provides a performance-stable airbag that reduces the amount of adhesive sealing material, is light in weight, has excellent storage properties, and does not cause gas leakage. It is.

  As a result of intensive studies to solve the above-mentioned problems, the present inventor uses a material having shape stability as an adhesive sealant, and makes its coating thickness and width within a specific range. The present inventors have found that it is possible to provide an extremely superior air bag that is lightweight, excellent in storability, and does not generate gas leak, and is stable in terms of performance.

That is, according to the present invention, in an airbag formed by joining two panels with a room temperature curable adhesive sealant, the adhesive sealant is discharged from a circular nozzle at 25 ° C. and applied to the base fabric. When the thickness of the adhesive seal material immediately after being applied is H ₀ , and the thickness of the adhesive seal material when left for 10 minutes after application is H ₁₀ , the following formula 1 is satisfied, and another base fabric is stacked. crimp to a predetermined thickness H _BH, the thickness of the adhesive sealant after curing is taken as H _AH, are those satisfying the formula 2 below,
H ₁₀ / H ₀ ≧ 0.8 (Formula 1)
H _AH / H _BH ≧ 0.8 (Formula 2)
The present invention relates to an airbag in which the width W _AH and the thickness H _AH of the adhesive sealing material after being cured by being sandwiched between the two panels satisfy the following expressions 3 and 4.
H _AH ≧ 1.0 (mm) (Formula 3)
W _AH / H _AH ≦ 7 (Formula 4)

The width _WAH and the thickness _HAH preferably satisfy the following formula 5.
W _AH × H _AH ≦ 9 (mm ² ) (Formula 5)

The width _WAH preferably satisfies the following formula 6.
W _AH ≦ 7 (mm) (Formula 6)

  According to the present invention, by using a material having shape stability as an adhesive sealing material, the adhesive sealing material is uniformly cured with a sufficient thickness even with a small application amount without increasing the coating width. In addition, by setting the thickness and width to a specific range, an air bag with improved lightness, storability, and suppression of gas leakage can be provided.

Hereinafter, the present invention will be described in detail.
FIG. 1 is a schematic plan view in which an adhesive sealing material 2 discharged from a nozzle 3 is applied on a panel 1 cut into a desired airbag shape.

<Panel>
The panel used in the present invention is an air bag for fabrics such as woven fabrics woven using fiber yarns, knitted fabrics woven using fiber yarns, and nonwoven fabrics (hereinafter sometimes referred to as base fabrics). It is cut into a shape.

  Examples of the fibers used include polyamide fibers such as nylon 6, 66 and 46, aromatic polyamide fibers (aramid fibers) represented by a copolymer of paraphenylene terephthalamide and aromatic ether, and polyethylene terephthalate. Polyester fibers, wholly aromatic polyester fibers, vinylon fibers, rayon fibers, polyolefin fibers such as ultra high molecular weight polyethylene, polyoxymethylene fibers, sulfone fibers such as paraphenylene sulfone and polysulfone, polyether ether ketone fibers, poly Organic fibers such as etherimide fiber and polyimide fiber, and inorganic fibers such as glass fiber, ceramic fiber, carbon fiber and metal fiber may be used, and these may be used alone or in combination. Among them, polyamide fibers and polyester fibers are preferable because they are easy to manufacture and have excellent heat resistance, and polyamide fibers are more preferable because they are excellent in impact resistance and have a large heat capacity.

  These fibers may contain a heat resistance improver, an antioxidant, a flame retardant, an antistatic agent, and the like.

  Further, the fiber fabric may be subjected to scouring and heat treatment.

  In addition, the form of the yarn, the fineness, the density of the fabric, the basis weight, and the like are not particularly limited, and those normally used for airbags may be appropriately selected.

  For example, when the structure of the fiber fabric is a woven fabric, plain weaving, satin weaving, twill weaving, Panama weaving, bag weaving, and the like are available. Among these, a woven fabric is preferable from the viewpoint of the elongation and strength of the fabric. Among these, a woven fabric is preferable in that it has excellent mechanical strength and the thickness can be reduced, and a plain weave structure is more preferable.

  Moreover, it is preferable that the single yarn strength of the fiber used is 5.4 cN / decitex or more in order to satisfy the physical characteristics as an airbag.

  The total fineness of these fibers is preferably 155 to 500 dtex. If it is less than 155 dtex, the strength of the fabric may not be maintained, and if it is greater than 500 dtex, the thickness of the base fabric increases, and the bag may have poor storage properties.

  In addition, the cross-sectional shape of the single fiber of these synthetic fibers is not particularly limited to round, flat, triangular, rectangular, parallelogram, hollow, star shape, etc., but in terms of productivity and cost, it has a round cross-section. Moreover, the thing of a flat cross section is preferable at the point that the thickness of a base fabric can be made thin and the stowability of a bag becomes good.

The cover factor when the fabric is a woven fabric is preferably 1500-2500. If the cover factor is less than 1500, the opening of the fabric will be large and it will be difficult to obtain the airtightness of the bag. If the cover factor is greater than 2500, the thickness of the fabric will increase and the bag will not be easily stored. There is a fear. Here, the cover factor means that the warp yarn total fineness is D ₁ (dtex), the warp yarn density is N ₁ (lines / 2.54 cm), the weft total fineness is D ₂ (dtex), and the weft yarn density Is N ₂ (lines / 2.54 cm), (D ₁ × 0.9) ^1/2 × N ₁ + (D ₂ × 0.9) ^1/2 × N ₂ .

  These fabrics may be coated on at least one side with a resin or the like for the purpose of improving heat resistance and reducing air permeability. The coating surface may be either inside or outside the airbag, but it is preferable that the coating surface be inside because the coating film can be prevented from being damaged even when an external force is applied to the airbag base fabric. .

  Examples of the resin used for coating include halogen-containing rubbers such as chloroprene rubber, high baron rubber, and fluorine rubber, silicone rubber, ethylene propylene rubber, ethylene propylene terpolymer rubber, nitrile butadiene rubber, styrene butadiene rubber, isobutylene isoprene rubber, Rubbers such as urethane rubber and acrylic rubber, and halogen-containing resins such as vinyl chloride resin, vinylidene chloride resin, chlorinated polyolefin resin and fluororesin, urethane resin, acrylic resin, ester resin, amide resin, olefin resin and silicone resin These are used, and these are used alone or in combination. Of these, silicone rubber and silicone resin are preferable in terms of excellent flexibility, heat resistance, and weather resistance.

  Furthermore, for the purpose of smoothly deploying the airbag, a process for reducing the friction of the coating resin film may be performed. As the treatment, specifically, a method of applying a fine powder such as talc to the coating resin film, a method of coating by coating the coating resin with a substance that reduces adhesiveness after curing, such as an organic titanium compound, And the method of providing an unevenness | corrugation to a coating resin film using an embossing apparatus etc. is mention | raise | lifted.

  Examples of the coating method include knife coating, gravure coating, spray coating, and lamination.

Moreover, as an application quantity of coating resin, 5-60 g / m < ² > is preferable. If the coating amount is less than 5 g / m ² , the air permeability of the fabric is increased and there is a risk of problems in the air tightness of the bag. Further, when a part of the base fabric fibers comes out from the coating layer, There is also a possibility that adhesiveness may worsen. When the coating amount is more than 60 g / m ² , the thickness of the woven fabric is increased, and there is a possibility that a problem occurs in the bag storage.

  Furthermore, in the present invention, it is preferable to perform a treatment for reducing the friction of the silicone coating resin film for the purpose of smoothly deploying the airbag. Regarding the treatment to reduce the friction of the silicone coating resin film, specifically, a method of applying a fine powder such as talc to the silicone coating resin film, the adhesiveness after curing of the organic titanium compound or the like to the silicone coating resin is reduced. Examples thereof include a method in which a substance is mixed and coating is performed, or a method in which an unevenness is imparted to the silicone coating resin film by using an embossing apparatus or the like.

<Cutting>
The fabric is cut into a predetermined airbag shape to produce a panel 1. The cutting method is appropriately selected from knife, laser melting, water jet and the like. Further, it is preferable that the panel 1 that has been cut is placed on a flat surface so that the cut chips are completely removed and wrinkles are not formed.

<Applying adhesive seal material>
The adhesive sealing material 2 is fed by a pump and discharged onto the panel 1 through the nozzle 3. The mouth shape of the nozzle 3 is not particularly limited, and among them, a circular shape is preferable because it is not necessary to rotate the nozzle according to the moving direction when coating in all directions of the X axis and the Y axis. The diameter of the nozzle 3 is selected to be the same as or larger than the diameter of the adhesive seal material to be applied. In the case where the adhesive sealing material 2 is a type in which two or more liquids are mixed and cured, a type in which a mixer for mixing inside is used for the nozzle 3 is used.

FIG. 2 is a schematic cross-sectional view of the adhesive sealing material 2 immediately after discharge, taken along the line CC in FIG. A circular nozzle is used as the nozzle 3. The symbol H ₀ (= W ₀ ) is the cross-sectional diameter of the adhesive sealing material 2.

  In FIG. 1, an adhesive sealant is applied through a nozzle. However, the present invention is not limited to this, and a printing method using a screen, a transfer method using an engraving roll, a method using a die cast, and the like. Can also be adopted.

<Adhesive seal material>
The adhesive sealing material 2 used in the present invention is appropriately selected from silicone adhesives, polyurethane adhesives, polyamide adhesives, nitrile rubber adhesives, polysulfide adhesives, and the like in consideration of adhesion to the panel. What is necessary is just to select, and it may be a thermoplastic thing or a thermosetting thing. Examples of the curing mechanism include room temperature moisture curing type, room temperature condensation reaction type, room temperature addition reaction type, heat curing type, and electron beam curing type. In the present invention, a room temperature curable adhesive is used.

  Among these, when the panel is coated with a silicone resin, it is preferably a silicone system, and when it is coated with a urethane resin, it is preferably a urethane system.

  The room temperature curable silicone-based adhesive seal material includes a condensation reaction type and an addition reaction type, and the addition reaction type is preferable in that the curing proceeds uniformly. In the condensation reaction type, it takes time to cure the inside of the portion in contact with the outside air.

  As the form of the adhesive sealing material, there are a one-component curing type, a two-component mixed curing type, and a mixed type of three or more components. Preferably there is.

  The viscosity of the adhesive sealing material before curing is preferably 300 Pa · s or more, more preferably 400 Pa · s or more at 25 ° C. When the viscosity is less than 300 Pa · s, it is easy to discharge, but it tends to be difficult to control the amount of liquid at the start and end of discharge. The upper limit is 900 Pa · s.

  The present invention is characterized by using an adhesive sealing material that satisfies Formula 1 when evaluated by the following method.

That is, the adhesive seal material is discharged when the adhesive seal material is discharged from the circular nozzle to the base fabric under the condition of 25 ° C. and the thickness of the adhesive seal material immediately after being applied to the base fabric is H ₀ , and is left for 10 minutes after the application. the material thickness is when the H _10, satisfies expression 1 below.
H ₁₀ / H ₀ ≧ 0.8 (Formula 1)

Here, as shown in FIG. 3, immediately after being applied to a substrate from a circular nozzle, the cross section of the adhesive and sealing material 2 in the A-A line in FIG. 1, its thickness H ₀ and the width W ₀ Togahobo The same circle.

  Over time, the room temperature curable adhesive seal material begins to cure, but since it is liquid, the circular cross-section gradually collapses to show an elliptical shape.

The shape of the adhesive seal material when left applied after 10 minutes, for example, as shown in FIG. 4, a large elliptical shape having a width W ₁₀ to the thickness H _10.

At this time, the adhesive seal material used in the present invention has an adhesive seal material thickness H ₀ immediately after being applied to the base fabric, and an adhesive seal material thickness H ₁₀ when left for 10 minutes after application,
H ₁₀ / H ₀ ≧ 0.8 (Formula 1)
It satisfies the relationship. H ₁₀ / H ₀ is preferably 0.85 or more. The upper limit is 1.

The fact that H ₁₀ / H ₀ is 0.8 or more indicates that the adhesive sealant well retains the shape immediately after application even when it is left for 10 minutes after application. It can be said that it is excellent in property.

  In the present invention, the adhesive sealing material is usually left for 10 minutes after the application, assuming the time taken from the time when the adhesive sealing material is applied to the panel for the airbag to the next pressure bonding step. The shape is taken into consideration, but it is not always necessary to leave it for 10 minutes before entering the crimping process.

Furthermore, the thickness H ₁₀ and the width W ₁₀ of the adhesive seal material when left for 10 minutes after application are as follows:
W ₁₀ / (W ₁₀ −H ₁₀ ) ≧ 3.5 (Formula 7)
Is preferably satisfied.

When W ₁₀ / (W ₁₀ -H ₁₀ ) is 3.5 or less, even when left for 10 minutes after application, there is little crushing, and the adhesive sealant holds the shape immediately after application well. It can be said that the shape stability is excellent. W ₁₀ / (W ₁₀ -H ₁₀ ) is preferably 4.0 or more.

Incidentally, the H ₀ may be regarded as the diameter of the circular nozzle used, the W ₁₀ and the thickness H _10, for bonding the sealing material after imparting 10 minutes, an average value when measured five locations.

  That is, the adhesive sealing material satisfying the formula 1 is difficult to sag and can maintain a uniform thickness. Not satisfying the expression 1 means that the adhesive seal material has been sag in a very short time after discharge, and the thickness of the adhesive seal material is also cured during the subsequent crimping process. Sada gets smaller and smaller. As a result, it becomes lower than the desired adhesive seal material thickness. In addition, since it is easily affected by the weight of the panel and wrinkles, the thickness varies and gas leaks from a portion having a small thickness. Furthermore, due to the variation in thickness, the two panels undulate into a concavo-convex shape, resulting in a hindrance to foldability.

<Crimping>
As shown in FIG. 5, the airbag of the present invention is formed by joining two panels 1 (not shown) and 4 using an adhesive sealing material 2 that satisfies Formula 1. Specifically, for example, it is crimped by sandwiching it between two top plates controlled at a predetermined interval by a spacer, or by a crimping roller controlled to a predetermined height with respect to the top plate. And joined. The panel 4 has substantially the same shape as the panel 1.

<Adhesive seal material shape after crimping>
However, at the time of the crimping step, of course, curing of the adhesive sealing material is not completed, and curing is usually performed for 24 hours. And even during this curing, sagging of the adhesive seal material occurs, so that the actual thickness is smaller than that even though the adhesive seal material is pressed to a predetermined thickness, causing air leaks. .

FIG. 6 shows a cross-sectional view taken along the line BB in FIG. 5 immediately after the two panels 1 and 4 are pressure-bonded. The side surface of the adhesive seal material 2 before curing is bent due to its own sag and the weight of the panel. FIG. 7 shows a cross-sectional view taken along the line BB after curing. The hardening of the adhesive sealing material can be determined by not crushing with a finger. The width W _AH after curing further increases due to sagging or the weight of the panel.

Adhesive seal material for use in the present invention, in addition to the equation 1, the thickness H _BH set during crimping and the actual thickness H _AH after curing, satisfies the following formula 2.
H _AH / H _BH ≧ 0.8 (Formula 2)

By satisfying Equation 2, the set thickness and the actual thickness after curing are substantially equal, so that two panels can be joined with a uniform desired thickness, and gas leakage can be prevented. Furthermore, it is not necessary to apply an excessive adhesive seal material in consideration of the reduction in thickness due to sagging, which contributes to weight reduction of the airbag and improved storage. Note that _HAH / _HBH is preferably 0.9 or more.

Here, in order to improve lightness and storage properties and suppress gas leakage, the shape of the adhesive seal material itself after curing is an important factor as well as the shape stability of the adhesive seal material. That is, the width W _AH and the thickness H _AH of the adhesive seal material after being cured satisfy the following expressions 3 and 4.
H _AH ≧ 1.0 (mm) (Formula 3)
W _AH / H _AH ≦ 7 (Formula 4)

Note that the width W _AH and the thickness H _AH of the adhesive seal material are average values when five locations of the cured adhesive seal material are measured.

The adhesive sealant has a thickness _HAH of 1 mm or more. Preferably, it is 1.2 mm or more. If the thickness _HAH is smaller than 1 mm, the airbag cannot withstand the gas pressure generated from the inflator when the airbag is inflated, and the adhesive sealant peels off from the panel and cannot protect the sewing portion, thereby causing gas leakage. Further, the upper limit is not particularly limited, but it is preferably 3 mm or less in consideration of storage properties.

  Since the adhesive sealing material used in the present invention has excellent shape stability as described above, there is little variation in thickness after curing. When involved in the manufacture of airbags, it is generally acceptable that the thickness varies, that is, the difference between the maximum thickness and the minimum thickness is within ± 0.6 mm, but an adhesive sealant that satisfies the above formula is used. In this case, the variation can be made smaller than that.

Further, the ratio (W _AH / H _AH ) between the width W _AH and the thickness H _AH of the cured adhesive sealing material is 7 or less. Preferably, it is 6 or less. If the ratio is greater than 7, the width is too wide with respect to the thickness, so that the amount of adhesive sealant used increases and the material cost increases. When the ratio is 7 or less, even if the thickness H _AH exceeds 1.5 mm, it does not impair the storability. The lower limit is not particularly limited, but is preferably close to 1.

Furthermore, it is preferable that the width _WAH and the thickness _HAH satisfy the following formula 5.
W _AH × H _AH ≦ 9 (mm ² ) (Formula 5)
As a result, the amount of the adhesive seal material is reduced, and the bag is superior in storage and cost. When W _AH × H _AH (cross-sectional area of the adhesive seal material) exceeds 9 mm ² , there is a possibility that the adhesive seal material is excessively provided for the purpose of suppressing gas leakage, and lightness, storage property, It tends to be inferior in cost. The cross-sectional area of the adhesive sealing material is more preferably 7 mm ² or less.

Furthermore, it is preferable that the width _WAH satisfies the following formula 6.
W _AH ≦ 7 (mm) (Formula 6)
When the width _WAH is larger than 7 mm, the foldability tends to decrease. The width _WAH is more preferably 6 mm or less.

<Sewing>
After the pressure bonding, when the adhesive sealing material is completely cured, the two panels are bonded. However, when a stronger bonding as an airbag is required, the bonded portion (that is, on the adhesive sealing material) is sewn into a thread. May be sewn. The sewing of the joint may be performed under known conditions and is not particularly limited. In addition, it is preferable from the point of shortening process time to sew immediately after the said joining process by an adhesive sealing material.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in more detail, this invention is not limited to these Examples. The evaluation method is as follows.

<Adhesive seal material thickness>
It measured with the constant pressure thickness measuring device (The load 44gf probe diameter Φ5 by TECLOK).

<Thickness variation>
It calculated | required from the difference of the maximum thickness of the adhesive sealing material measured by the said method, and minimum thickness.

<Leak prevention performance>
Nitrogen gas was filled until the air bag internal pressure reached 70 KPa, and after 6 seconds, the bag internal pressure kept 10 KPa or higher was rated as ◯, and 10 KPa or lower was evaluated as X.

Example 1
Nylon 66 fiber with a total fineness of 470 dtex, 72 filaments, round cross section, single yarn strength of 8.8 g / decitex is used for warp and weft yarns so that the weaving density is 46 / 2.54 cm for both. Weaving in a water jet loom yielded a plain weave with a cover factor of 1885. The obtained fabric was scoured and heat-set at 185 ° C. for 30 seconds, and then, as a silicone coating elastomer, a solvent-free liquid silicone rubber (manufactured by Toray Dow Corning Co., Ltd., main component methyl vinyl silicone rubber, heat curing) The coating was performed with a knife coater so that the coating amount was 25 g / m ² . Thereafter, heat treatment was performed at 180 ° C. for 2 minutes to obtain a coated base fabric.

Next, the coating base fabric is cut into two panels having the shape shown in FIG. 1, and the room temperature curing type 2 in which H ₁₀ / H ₀ = 0.89 and H _AH / H _BH = 1 are formed on one coating surface. Liquid mixed adhesive seal material (manufactured by Toray Dow Corning Co., Ltd., main component methyl vinyl silicone rubber, room temperature addition reaction type adhesive, viscosity of 400 Pa · s at 25 ° C.) is applied to a predetermined position through a circular nozzle of Φ3.2 mm. did. The cross section of the adhesive sealing material immediately after application was almost circular (H ₀ = 3.2 mm). Subsequently, the other panels were overlapped, and the panels were pressure-bonded between top plates whose height (H _BH ) was adjusted to 1.5 mm with a spacer. This was allowed to cure at room temperature for 24 hours. Finally, using an 1400 dtex nylon 66 sewing thread so as to penetrate the widthwise center part of the adhesive sealant, sewing is performed with 3.5 stitches / cm of main stitches to obtain the airbag of the present invention. It was.

Note that the adhesive sealing material comprising, thickness after leaving 10 minutes after application _{(H 10)} is 2.8 mm, the width _{(W 10)} is 3.5 mm, the thickness after curing _{(H AH)} is 1.5 mm (variation ± 0.2 mm) and width (W _AH ) were 5.5 mm.

  The obtained airbag had a small amount of adhesive sealant applied and was excellent in leak prevention performance.

Example 2
On the coating surface of the panel obtained in the same manner as in Example 1, a room temperature curable two-component mixed adhesive sealing material with H ₁₀ / H ₀ = 0.91 and H _AH / H _BH = 1 (Toray Dow Corning Co., Ltd.) A company-made main component methyl vinyl silicone rubber, room temperature addition reaction type adhesive, viscosity of 400 Pa · s at 25 ° C. was applied to a predetermined position through a circular nozzle of Φ2.7 mm. The cross section of the adhesive sealing material immediately after application was almost circular (H ₀ = 2.7 mm). Subsequently, the other panels were overlapped, and the panels were pressure-bonded between top plates whose height (H _BH ) was adjusted to 1.2 mm with a spacer. This was allowed to cure at room temperature for 24 hours. Finally, using an 1400 dtex nylon 66 sewing thread so as to penetrate the widthwise center part of the adhesive sealant, sewing is performed with 3.5 stitches / cm of main stitches to obtain the airbag of the present invention. It was.

Note that the adhesive sealing material comprising, thickness after leaving 10 minutes after application _{(H 10)} is 2.5 mm, the width _{(W 10)} is 3.0 mm, the thickness after curing _{(H AH)} is 1.2 mm (variation ± 0.2 mm) and width (W _AH ) were 5.0 mm.

  The obtained airbag was superior in leak prevention performance although the application amount of the adhesive sealant was smaller than that in Example 1.

Comparative Example 1
As an adhesive seal material, H ₁₀ / H ₀ = 0.79, H _AH / H _BH = 0.6, room temperature curable adhesive seal material (manufactured by Toray Dow Corning Co., Ltd., main component methyl vinyl silicone rubber, room temperature addition) An adhesive sealant was applied, crimped and sewn on the panel in the same manner as in Example 1 except that a reactive adhesive, a viscosity of 200 Pa · s at 25 ° C., and a thixotropy index of 1.72) was used. Got.

Note that the adhesive sealing material comprising, thickness after leaving 10 minutes after application _{(H 10)} is 2.3 mm, the width _{(W 10)} is 3.5 mm, the thickness after curing _{(H AH)} is 0.95 mm (variation ± 0.5 mm) and width (W _AH ) were 8.5 mm.

  The adhesive sealing material used was particularly inferior in leak prevention performance because the sagging during curing was large and the thickness after curing was insufficient.

Comparative Example 2
On the coating surface of the panel obtained in the same manner as in Example 1, a room temperature curable adhesive sealing material with H ₁₀ / H ₀ = 0.72 and H _AH / H _BH = 1 (manufactured by Toray Dow Corning Co., Ltd., Main component methyl vinyl silicone rubber, room temperature addition reaction type adhesive, viscosity of 200 Pa · s at 25 ° C., thixotropy index 1.72) was applied to a predetermined position through a circular nozzle of Φ3.9 mm. The cross section of the adhesive sealant immediately after application was almost circular (H ₀ = 3.9 mm). Subsequently, the other panels were overlapped, and the panels were pressure-bonded between top plates whose height (H _BH ) was adjusted to 0.8 mm with a spacer. Next, curing and sewing were performed in the same manner as in Example 1 to obtain an airbag.

Note that the adhesive sealing material comprising, thickness after leaving 10 minutes after application _{(H 10)} is 2.9 mm, the width _{(W 10)} is 5.2 mm, the thickness after curing _{(H AH)} is 0.8 mm (variation ± 0.2 mm) and width (W _AH ) were 15.0 mm.

  Considering the sagging during curing that occurred in Comparative Example 1, the thickness at the time of crimping was set small, so the change in thickness before and after curing was small. However, since the thickness was 0.8 mm, the leak prevention performance was inferior as in Comparative Example 1. In addition, in order to maintain the thickness of the adhesive seal material before pressure bonding to some extent, a large nozzle diameter was selected in consideration of a decrease in thickness due to sagging, so that the application amount was excessive.

Comparative Example 3
On the coating surface of the panel obtained in the same manner as in Example 1, a room temperature curable adhesive sealing material having H ₁₀ / H ₀ = 0.75 and H _AH / H _BH = 0.5 (main component silicone rubber, room temperature An addition-reactive adhesive, viscosity of 500 Pa · s at 25 ° C., was applied to a predetermined position through a circular nozzle having a diameter of 3.2 mm. The cross section of the adhesive sealing material immediately after application was almost circular (H ₀ = 3.2 mm). Subsequently, crimping, curing and sewing were performed in the same manner as in Example 1 to obtain an airbag.

Note that the adhesive sealing material comprising, thickness after leaving 10 minutes after application _{(H 10)} is 2.2 mm, the width _{(W 10)} is 3.5 mm, the thickness after curing _{(H AH)} is 0.7 mm (variation ± 0.3 mm) and width (W _AH ) were 12.0 mm.

  The adhesive sealing material used was particularly inferior in leak prevention performance because the sagging during curing was large and the thickness after curing was insufficient.

Comparative Example 4
On the coating surface of the panel obtained in the same manner as in Example 1, a room temperature curable adhesive sealant with H ₁₀ / H ₀ = 0.92 and H _AH / H _BH = 1 (manufactured by Toray Dow Corning Co., Ltd., Main component methyl vinyl silicone rubber, room temperature addition reaction type adhesive, viscosity of 400 Pa · s at 25 ° C. was applied to a predetermined position through a circular nozzle of Φ2.5 mm. The cross section of the adhesive sealing material immediately after application was almost circular (H ₀ = 2.5 mm). Subsequently, the other panels were overlapped, and the panels were pressure-bonded between top plates whose height (H _BH ) was adjusted to 0.5 mm with a spacer. Finally, curing and sewing were performed in the same manner as in Example 1 to obtain an airbag.

Note that the adhesive sealing material comprising, thickness after leaving 10 minutes after application _{(H 10)} is 2.3 mm, the width _{(W 10)} is 2.7 mm, the thickness after curing _{(H AH)} is 0.5 mm (variation ± 0.1 mm) and width (W _AH ) were 10.0 mm.

  Although no sagging or variation was observed, the thickness after curing was 0.5 mm, so the leak prevention performance was poor.

Comparative Example 5
On the coating surface of the panel obtained in the same manner as in Example 1, a room temperature curable adhesive sealing material with H ₁₀ / H ₀ = 0.85 and H _AH / H _BH = 1 (manufactured by Toray Dow Corning Co., Ltd., Main component methyl vinyl silicone rubber, room temperature addition reaction type adhesive, viscosity of 400 Pa · s at 25 ° C. was applied to a predetermined position through a circular nozzle of Φ3.5 mm. The cross section of the adhesive sealing material immediately after application was almost circular (H ₀ = 3.5 mm). Subsequently, the other panels were overlapped, and the panels were pressure-bonded between top plates whose height (H _BH ) was adjusted to 1.0 mm with a spacer. Finally, curing and sewing were performed in the same manner as in Example 1 to obtain an airbag.

Note that the adhesive sealing material comprising, thickness after leaving 10 minutes after application _{(H 10)} is 3.0 mm, the width _{(W 10)} is 3.8 mm, the thickness after curing _{(H AH)} is 1.0 mm (variation ± 0.1 mm) and width (W _AH ) were 10.0 mm.

  Although no sagging or variation was observed, the application amount of the adhesive sealant was excessive, so the width was excessive with respect to the thickness after curing, and the lightness was inferior.

It is a schematic plan view which has apply | coated the adhesive sealing material discharged from the nozzle on the panel cut | judged in the airbag shape. It is a schematic cross section of the adhesive sealing material in the CC line | wire of FIG. 1 immediately after discharge. It is a schematic cross section of the adhesive sealing material 2 in the AA line of FIG. It is a schematic cross section which shows the shape of the adhesive sealing material when it is left to stand for 10 minutes after provision in the AA line of FIG. It is a schematic plan view which shows the airbag which overlaps two panels. It is a schematic cross section in the BB line of FIG. 5 just after crimping | bonding two panels. It is a schematic cross section in the BB line of Drawing 5 after adhesion seal material hardening.

Explanation of symbols

1 panel 2 adhesive seal material 3 nozzles 4 Panel H discharging adhesive thickness W of the sealing material of cross-sectional diameter H ₀ substrate applied immediately after the adhesive seal material cross-sectional diameter H ₁₀ substrate granted 10 minutes after the adhesive seal material ₁₀ immediately after the the width of the adhesive sealing material after the thickness W _AH curing of the adhesive sealing material after the thickness H _AH curing set during width H _BH crimping substrate granted after 10 minutes adhesion sealant

Claims (3)

In an airbag formed by joining two panels with a room temperature curable adhesive seal material, the adhesive seal material is ejected from a circular nozzle under a condition of 25 ° C. and immediately after being applied to the base fabric. When the material thickness is H ₀ , and the thickness of the adhesive seal material when left for 10 minutes after application is H ₁₀ , the following formula 1 is satisfied, and another base fabric is stacked to obtain a predetermined thickness H _BH When the thickness of the adhesive seal material after being crimped and cured to _HAH is satisfied, the following formula 2 is satisfied:
H ₁₀ / H ₀ ≧ 0.8 (Formula 1)
H _AH / H _BH ≧ 0.8 (Formula 2)
An airbag in which the width W _AH and the thickness H _AH of the adhesive seal material after being cured by being sandwiched between the two panels satisfy the following expressions 3 and 4.
H _AH ≧ 1.0 (mm) (Formula 3)
W _AH / H _AH ≦ 7 (Formula 4) The airbag according to claim 1, wherein the width _WAH and the thickness _HAH satisfy the following formula 5.
W _AH × H _AH ≦ 9 (mm ² ) (Formula 5) The airbag according to claim 1 or 2, wherein the width _WAH satisfies the following expression (6).
W _AH ≦ 7 (mm) (Formula 6)

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