JP2006327521A - Airbag and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lightweight airbag for a side part with superior air-tight sealing property capable of being stored compact. <P>SOLUTION: In the airbag for a side part, covering surfaces of two sheets of body base clothes covered with a heat-resistant material on at least one surface are superposed to be formed to a bag-like shape and it is integrally sutured in the state that adhesive silicone, preferably addition reaction type thermosetting adhesive silicone having JIS-A hardness after cured of 20 or less and the degree of breaking elongation of 1,400% or higher is clamped between the superposed parts. The body base cloth has a base cloth unit weight except for the covering material of 210 g/m<SP>2</SP>or less, cover factor of 750 or more and a coated amount of the covering material of 50 g/m<SP>2</SP>or less. In compression thickness measured in the state it is folded six times according to JIS L-1096 (8.18 method), difference (A-A<SB>0</SB>) of compression thickness (A) of a laminated body in which the adhesive silicone having thickness of 1 mm is clamped between two sheets of body base clothes and compression thickness (A<SB>0</SB>) of two sheets of body base clothes is 25 mm or less, preferably 20 mm or less. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an airbag for protecting an occupant at the time of an automobile collision, and relates to a lightweight and compact side airbag that is excellent in airtightness.

  In recent years, airbag systems have become widespread as safety devices for occupant protection, and the number of mounting parts for driver seats, passenger seats, side collision protection, and rear seats has increased. In particular, an airbag that protects an occupant from an impact at the time of a side collision, that is, a side airbag, has attracted attention as a means for improving safety for the occupant.

Depending on the shape and structure of the car, it may be easy to roll over in the event of a side collision, and the side airbag is required to be inflated for a long time so that the occupant is not released to the outside during the rollover. The

  Since the side airbag formed by stitching leaks gas from its seam when inflated, a so-called adhesive material called a sealing agent that seals the seam is used for the stitched portion. When such a side airbag is folded, it may be difficult to fold compactly depending on the specifications of the main body base fabric, the thickness of the stitched portion and the sealing agent, the characteristics of the sealing agent, and the like.

  In order to make the airbag excellent in storage, a light and thin base fabric using a thin thread, for example, a thread of 300 dtex or less, may be used as the main body base cloth, but in a narrow space between the occupant and the side window for a short time. However, the pressure resistance against the impact of the expanding gas that is suddenly ejected when expanding and expanding, and the robustness when contacting or rubbing to the side window glass fragments damaged by the collision object, etc. tend to be insufficient. However, it has been difficult to satisfy all the characteristics such as compact storage property, robustness and pressure resistance.

  For example, in Patent Document 1 (Japanese Patent Laid-Open No. 11-227550), heating is performed between heat-resistant coating layers applied to the surface of a base fabric in an automobile airbag in which the peripheral portion of the base fabric is bonded by adhesion. A method for imparting strong peel strength using a curable silicone rubber-based adhesive has been proposed. According to this method, a high adhesive strength with an adhesive bond portion peeling strength of 200 N / 25 mm or more can be obtained, but in order to obtain a high adhesive strength, the heat-resistant coating layer can be infiltrated into the fabric of the base fabric. Although described, depending on the hardness of the silicone rubber adhesive, the adhesive bonding portion becomes extremely hard, which may impair compactness when the airbag is folded. The conditions for curing the adhesive also require a high temperature and a long time of 150 ° C. × 60 minutes.

  Patent Document 2 (Japanese Patent Application Laid-Open No. 2001-1854) discloses a technique for joining the edges of two panels with a sewing thread and an elastic adhesive having an elongation of 200% or more. In the specification text of Patent Document 2, it is described that it is preferable to use an elastic adhesive having an elongation of about 200 to 1000%, but only the elongation of the adhesive provides good compactness when the airbag is folded. It cannot be in the range.

  Further, Patent Document 3 (Japanese Patent Application Laid-Open No. 2002-225660) includes two or more base fabrics using a woven fabric having a cover factor of 1800 or more (in the calculation method according to the present application, 709 or more). Has a higher bursting strength than the occupant side fabric, reduces the average bending stiffness (B) of the occupant side fabric measured by KES, is less likely to break through when the vehicle rolls over, and the occupant is injured by frictional abrasion. An air bag without air is proposed. This patent uses a strong base fabric with high bursting strength for the base fabric on the window side and a flexible base fabric on the passenger side, but the flexural rigidity of the base fabric itself is specified, but the entire airbag There is no description about the bending resistance, and an airbag excellent in compactness when folded is not necessarily obtained.

JP-A-11-227550 JP 2001-1854 A JP 2002-225660 A

    The present invention provides a side airbag that has both high airtightness required for side airbags, particularly curtain airbags, and extremely excellent robustness against objects contacting the airbag, and is lightweight and compact. It is intended to provide.

That is, the present invention
(1) At least one surface is covered with two heat-resistant materials, and the covering surfaces of the two main body fabrics are overlapped to form a bag, and are integrally stitched with adhesive silicone sandwiched between the overlapping portions. In the side airbag, the base fabric has a basis weight of 210 g / m ² or less excluding the covering material, a cover factor of 750 or more, and a coating amount of the covering material of 50 g / m ² or less. And when the said main body base fabric and adhesive silicone separately form a laminated body from these, in the compression thickness measured in the state where this laminated body was folded 6 times by JIS L-1096 (8.18 method) The difference between the compression thickness (A) of the laminate in which the adhesive silicone having a thickness of 1 mm is sandwiched between the two main body fabrics and the compression thickness (A ₀ ) of only the two main body fabrics (A ₀ ) A-A ₀ ) is 25 mm or less Air bag,
(2) The adhesive silicone is a thermosetting addition-reactive adhesive silicone, the cured JIS-A hardness is 20 or less, and the initial elongation at break E ₀ after curing is 1400% or more. The side airbag according to (1), characterized in that it is characterized in that
(3) The ratio E / E ₀ between the breaking elongation E (%) and the initial breaking elongation E ₀ (%) after the heat treatment at 100 ° C. for 250 hours after curing is 0.8 or more. The airbag according to (1) or (2),
(4) The airbag according to any one of claims 1 to 3, wherein a single yarn thickness of the fiber yarn constituting the main body base fabric is 3 dtex or less,
(5) A plurality of body base fabrics coated with a heat-resistant material on at least one side are overlapped with each other to form a bag, and are integrally stitched with adhesive silicone sandwiched between the overlapping portions. In the method for manufacturing a side airbag, a base fabric having a basis weight of 210 g / m ² or less excluding a covering material and a cover factor of 750 or more is used as the main body base fabric. It is a manufacturing method by heat-curing at a temperature of 80 to 140 ° C. and a time of 5 minutes or less using an addition-reaction type adhesive silicone, and the main body base fabric and the adhesive silicone are separated from these. When a laminate is formed, the laminate has a thickness of 1 between two body base fabrics in a compression thickness measured in a state where the laminate is folded 6 times according to JIS L-1096 (8.18 method). compression thickness of the sandwiched laminate adhesive silicone of m (A) and two compression thickness of the main body base cloth only (A ₀₎ the difference between (A-A ₀₎ characterized in that a 25mm or less An airbag manufacturing method,
It is about.

  According to the present invention, it is possible to obtain a highly reliable side airbag that is light and compact and can be stored compactly and that is excellent in airtightness and robustness with excellent productivity.

The airbag according to the present invention is formed in a bag shape by overlapping the covering surfaces of two main body base fabrics coated at least on one side with a heat-resistant material, and adhesive silicone is sandwiched between the overlapping portions. Is a side airbag that is integrally stitched with, and as a specification of the main body fabric used for the airbag, the basis weight is 210 g / m ² or less, and the cover factor that is an index representing the denseness of the fabric structure is 750 or more, It is important that the coating amount of the coating material is 50 g / m ² or less.

Since the fabric weight of the base fabric directly affects the weight of the airbag, the fabric weight of the base fabric needs to be 210 g / m ² or less, preferably 200 g / m ² or less in order to obtain a lightweight bag. ^When it exceeds ² , it is difficult to obtain a lightweight airbag. The basis fabric weight here refers to the weight of only the fabric excluding the covering material.

  The cover factor of the base fabric must be 750 or more, preferably 750 to 950. When the cover factor calculated from the decitex (dtex) of the yarn constituting the base fabric and the driving density (lines / cm) of the woven fabric is less than 750, the woven fabric has a rough structure. The covering amount of the functional material increases and the basis weight of the main body base fabric becomes heavy. In addition, when the airbag is shockedly deployed, the fabric is likely to be misaligned, and the joint may be damaged. On the other hand, when the cover factor exceeds 950, not only the tearing strength is lowered, but also the woven fabric becomes extremely hard and the folding volume cannot be reduced.

  Here, the cover factor (CF) of the woven fabric is an index indicating the denseness of the woven fabric structure. The warp density and weft density (Nw and Nf) (lines / cm) of the woven fabric and the warp and weft used in the woven fabric It is calculated | required from the product with thickness (Dw and Df) (decitex).

CF = Nw × √Dw + Nf × √Df
It is also an essential requirement in the present invention that the coating amount of the heat-resistant material coated on at least one surface of the main body base fabric is 50 g / m ² (in terms of solid content) or less, preferably 40 g / m ² or less. Since the heat-resistant material is coated on the entire base fabric, reducing the coating weight as much as possible to reduce the weight of the base fabric and the folding thickness is a lightweight and compact airbag aimed by the present invention. It is important to get.

Furthermore, in the present invention, in the compression thickness measured according to JIS L-1096 (8.18 method) in a folded state assuming 6 wearing of the curtain bag, the thickness is between two main body base fabrics. The difference (A-A ₀ ) in the compression thickness that can be calculated from the compression thickness (A) of the laminate sandwiching 1 mm adhesive silicone and the compression thickness (A ₀ ) of only the two main body base fabrics is 25 mm. Hereinafter, it is also important that it is preferably 20 mm or less, more preferably 15 mm or less.
In conventional airbags, in order to reduce the folding volume, attention has been paid only to the softness and hardness of the main body base fabric or the adhesive material sandwiched between the main body base fabrics. It has been found that the thickness at the time of compression of the laminated portion made of the base fabric and the adhesive material is important. That is, there is no problem in the storage property of the airbag when the difference between the compression thickness calculated from the compression thickness of the laminated portion and the compression thickness of the main body base fabric in the above measurement method is 25 mm or less, but the compression thickness It was found that when the difference between the two exceeds 25 mm, the folding volume becomes large and the workability is likely to be hindered.
Normally, the side airbag that is deployed along the side window glass is stored in the lower part of the side ceiling in a small folded state, but since the storage volume is small, the folding capacity of the side airbag is small. Is required to be small. A plurality of body base fabrics, adhesive silicone and sutures are integrally laminated on the laminated part where the adhesive silicone is sandwiched. If the bending resistance of this part is large, it will be repelled after the airbag is bent once. Inflating the air bag for easy attachment to the vehicle body may interfere with the operation of storing the airbag in the cylindrical body, or the operation of attaching the vehicle body to the vehicle body may be hindered.

    In the present invention, at least one surface of the two main body base fabrics coated with a heat-resistant material is overlapped with each other to form a bag, and is integrally stitched with adhesive silicone sandwiched between the overlapping portions. ing. In this structure, gas leakage from the seam of the stitched portion is sealed with adhesive silicone. Accordingly, the adhesive silicone needs to be applied along the seam line to be stitched and in an appropriate width with respect to the width of the seam line. As a result, the airbag according to the present invention can secure high pressure resistance characteristics by stitching and can exhibit excellent airtightness by adhesive silicone.

  The adhesive silicone used in the present invention is a curable silicone mainly composed of a condensation type, an addition reaction type or an addition reaction type, which may be either room temperature curable or thermosetting. A curable addition-reactive silicone is preferred. In room temperature curing, a long time of several hours or more is required for curing. Particularly in the case of condensation type room temperature curing, adjustment of curing conditions of temperature and humidity becomes difficult.

  Furthermore, in the present invention, an adhesive silicone having a cured JIS-A hardness of 20 or less, preferably 2 to 15 and an initial breaking elongation of 1400% or more, preferably 1500 to 2000% is used. Is preferred. By using extremely soft silicone, the joint can be kept flexible and the volume of folding can be reduced. When the JIS-A hardness exceeds 20, the folding resistance of the stitched laminated portion increases and the folding volume tends to increase.

  In addition, since the initial breaking elongation is 1400% or more, the effect of relaxing the impact by the elongation of the silicone of the joint portion occurs with respect to the peeling force and shearing force of the joint portion that are generated impactively when the airbag is deployed, An excellent seam sealing function can be exhibited, and the coating thickness can be made thinner than that of the low elongation type.

In order to develop this relaxation effect over a long period of time, it is desired that the adhesive silicone has a high elongation characteristic that is less likely to change depending on the environment. It is preferable that the ratio to the initial elongation at break E ₀ , E / E ₀ is 0.8 or more, preferably 0.9 or more. By setting E / E ₀ to be 0.8 or more, the stitched laminated portions of the base fabrics are always joined in an elastic state, and the effect of reducing the impact generated at the joined portions even during rapid deployment is great.

  Further, in the present invention, overlapping portions of the main body base fabrics, for example, peripheral joints, joints inside the bag body, portions around the inflator attachment port, and the like that receive internal pressure of the bag body or impact force when the bag body is deployed In addition to bonding with adhesive silicone, it is important to sew with a sewing thread. That is, by joining and sewing with the adhesive silicone sandwiched between the base fabrics, it is robust and airtight without applying a sealant etc. to the top and bottom of the seam and the inside of the seam allowance of the outer periphery stitching after stitching In addition, the seam receives tensile stress generated in the adhesive silicone due to the inflation of the airbag, thereby preventing an excessive impact force from being applied to the adhesive silicone.

  Furthermore, in the present invention, it is effective not only to reduce the bending resistance of the stitching laminated portion, but to use a thin thread having a single yarn thickness of 3 dtex or less of the fiber yarn constituting the main body base fabric, The flexibility of the entire body base fabric is improved, and the storage volume of the entire airbag can be reduced.

In addition, as a method of manufacturing an airbag according to the present invention, a base fabric having a base fabric weight of 200 g / m ² or less and a cover factor of 750 or more is used as a main body base fabric, and a thermosetting adhesive silicone is used. JIS L-1096 (8.18 method) was used to measure in a folded state 6 times by heat-curing at a temperature of 80 to 140 ° C. and a time of 5 minutes or less. In terms of compression thickness, the compression thickness (A) of a laminate in which an adhesive silicone having a thickness of 1 mm is sandwiched between two body base fabrics and the compression thickness (A ₀ ) of only two body base fabrics. The manufacturing method of the airbag characterized by making the difference (A-A ₀ ) to be 25 mm or less is also an essential requirement.

  That is, according to the method of the present invention, it is possible to obtain an air bag that is highly flexible in a very short time, has a small volume after folding, and has excellent storage properties.

In the present invention, when the adhesive silicone is applied to the overlapped portion of the two main body base fabrics constituting the airbag under specific conditions, for example, the application thickness of the adhesive silicone is T ₀ (mm), the adhesiveness When the application allowance from the silicone seam line is D (mm) and the initial breaking elongation of the adhesive silicone is E ₀ (%), the application may be performed so as to satisfy the following formula.

a) 0.3 ≦ T ₀ ≦ 1.5,
_{b) 2 ≦ D ≦ (E} 0/100 -1) × T 0/2
The coating thickness T ₀ is in the range of 0.3 to 1.5 mm, preferably 0.3 to 1.2 mm as shown in the formula a). The thickness of the coating affects the adhesive strength of the adhesive silicone. If it is thinner than 0.3 mm, the adhesive strength is insufficient. If it exceeds 1.5 mm, high adhesiveness is obtained, but the joint becomes thick and the air bag becomes coarse. It is easy to impair the storage property.

    Also, the coating allowance D from the seam line of the adhesive silicone should be set within the proper range shown in the formula b) in order to securely seal the seam without breaking the adhesive silicone when the airbag is inflated. Is preferred.

As shown in FIG. 4, when the airbag is inflated, the two upper and lower body base fabrics are pulled so that they peel off, and the adhesive silicone that constitutes the coating allowance D from the seam line also follows this movement. The distance between the application ends of the adhesive silicone is also increased from T ₀ to T. Then, adherent silicone coating end distance T (when tensile sufficiently is substantially equal to the length 2D) seals the seam to exceed the breaking elongation E _0. If the elongation at break E0 is extended to ₀ or more, it breaks, and when the fracture surface reaches the seam, the sealing function is lost.

    If the coating allowance D from the seam line is less than 2 mm, the seam line and the coating end are too close to follow the peeling behavior of the base fabric, and depending on the seam that expands due to expansion in some cases, the seam sealing function is sufficient It is difficult to demonstrate. Also, when the adhesive silicone having a large breaking elongation is used when the value is larger than the right side of the formula b), D becomes unnecessarily large, the thickness and volume of the joint become large, and the air bag can be stored. It is easy to damage.

Furthermore, it is a more preferable correspondence of the present invention to change the application thickness T ₀ of the adhesive silicone depending on the airbag portion. In particular, joint portion located on an outer peripheral joint part located inside the bag body from the coating thickness _T 0 (out) of (3 in Figure 1) coating thickness (4 a to 4 d in FIG. 1) _T 0 (in) It is preferable that T ₀ (out) and T ₀ (in) satisfy the relationship of T ₀ (out) ≦ T ₀ (in) ≦ 3 × T ₀ (out). The joint inside the bag receives tensile force from both sides of the joint due to the expansion of the bag. In addition, the vicinity of the inflator attachment port that supplies gas for inflating the bag body also receives a large impact force at the initial stage of deployment, and a large tensile force acts on the joint near the attachment port. That is, the adhesive silicone coating thickness T ₀ is made thicker at sites that receive large stresses, and other parts are made to have appropriate amounts so that the adhesive silicone can be used without waste and the sealing function can be effectively expressed. be able to.

  In the present invention, the heat-resistant material for covering at least one surface of the main fabric is usually a coating material used for imparting heat resistance, air permeability, etc. to the airbag fabric, such as silicone resin or rubber. , Polyurethane resin or rubber (including silicone modified, fluorine modified, etc.), chlorine-containing rubber such as chloroprene rubber and hyperon rubber, fluorine rubber, polyester resin or rubber, polyamide resin or rubber, etc. One or two or more materials having excellent adhesiveness with silicone may be selected, but a silicone resin or rubber is preferable.

  The heat resistant material can be applied to the base fabric as long as it can ensure uniform application, adhesion to the base fabric, and airtightness of the coating layer. The coating method (knife, kiss, reverse, comma), mark Any processing method such as a printing method (screen, roll, rotary), dipping method or spray method may be used.

The coating amount of the heat resistant material on the main body base fabric is 50 g / m ² or less, but within this range, depending on the case, both sides of the fabric may be coated. In that case, the coating amount on one side may be changed, or both sides may have the same coating amount.

  Application of the adhesive silicone to the base fabric covering layer may be selected from a method of applying a coating pattern with a trowel, a pressure nozzle coating method using air, a piston extrusion coating method, a screen coating method, etc., but is not limited thereto. It is not a thing.

  The application width of the adhesive silicone may be selected according to the bonding site, the bonding width, and the like, and is determined from the relationship between the above-described a) and b) expressions, the application thickness, the seam width, and the like. The range may be 20 mm.

  The adjustment of the coating thickness is performed by applying two layers of base fabric obtained by applying adhesive silicone to the coated surface of one main body base fabric and superimposing the other main body base fabric at regular intervals. What is necessary is just to press and perform with a flat plate or a pair of roll, a blanket. Further, when partially changing the coating thickness, for example, the gap corresponding to the coating thickness for each part is adjusted with a thickness gauge, or two sheets whose surface shape is processed in advance to the coating thickness for each part What is necessary is just to press with a flat plate.

  As already described, the adhesive silicone used in the present invention is preferably an addition reaction type or a thermosetting silicone mainly composed of an addition reaction type. It is also preferable to use a solvent-free type, although the silicone is paste-like, but unlike rubber glue in which various polymers are dissolved and diluted with a solvent, the solvent does not evaporate like rubber glue. It is also preferable from the environmental viewpoint.

  The thermosetting addition-reactive silicone is not particularly limited as long as it satisfies the required properties such as adhesion to the heat-resistant coating material, heat resistance, and flexibility. For example, vinyldimethylpolysiloxane as the main agent and hydrostatic as the crosslinking agent. A gensilane group (≡Si—H) -containing compound and a platinum compound as a curing catalyst may be used, but are not limited thereto.

  In addition, the viscosity of adhesive silicone, pot life after mixing (pot life), etc., take into account the viscosity of the coating solution, the workability of coating, the characteristics after curing, etc. What is necessary is just to select suitably according to the kind, quantity, etc. of an agent. For example, the viscosity of silicone may be selected from 50 to 500 Pa · s and the pot life from 0.2 to 24 hours. The adhesive silicone used in the present invention may be usually heat-cured, but it was heat-cured when it was difficult to cure in a short time, such as when the coating amount was extremely large or the airbag shape was large. Thereafter, it may be cured at room temperature for 2 to 24 hours.

  In order to improve the adhesion between the main body base fabric and the heat-resistant material, pretreatment such as primer treatment or plasma processing may be performed on the fabric surface or main body base fabric surface in advance. Furthermore, in order to improve the physical properties of the heat-resistant material and the adhesion between the base fabric and the material, the material is applied to the base fabric and then dried and solidified in a process of contact or non-contact, high energy treatment ( High frequency, electron beam, ultraviolet ray) or the like may be performed.

  The adhesive property between the heat-resistant material and the adhesive silicone is preferably a state in which the adhesive silicone does not coherently break, but the cohesive failure of the adhesive silicone. If there is no peeling, gas leakage from the seam can be prevented even when the joint is sewn.

  In the heat-resistant material and adhesive silicone used in the present invention, various additives usually used for improving processability, adhesiveness, surface characteristics or durability, for example, a crosslinking agent, a silane coupling agent, Reaction accelerator, reaction retarder, adhesion promoter, heat stabilizer, antioxidant, light stabilizer, anti-aging agent, lubricant, smoothing agent, anti-tack agent, pigment, water repellent, oil repellent, titanium oxide, etc. One or two or more of a masking agent, a gloss imparting agent, a flame retardant, a plasticizer, and the like may be selected and mixed.

  In particular, in order to impart durability to the adhesive silicone used in the present invention, among the above-mentioned various additives, a reaction accelerator, an adhesion imparting agent, a heat stabilizer, a filler and the like may be appropriately selected. 1) Metal oxides such as iron and titanium, hydroxides, fillers such as carbon, 2) Having active groups such as epoxy groups, amino groups, imino groups, carboxyl groups, mercapto groups, and alkyl-substituted and / or An adhesion-imparting agent such as an alkoxyl-substituted silane compound may be used, but is not limited thereto.

  The body base fabrics may be overlapped with each other by aligning the surfaces of the heat-resistant materials, but two base fabrics may be stacked, or one base fabric may be folded and stacked. Even if the outer periphery of the two overlapping base fabrics is further folded, or the outer periphery of the base fabric on the larger side of two similar base fabrics is folded back on the smaller side like a “glue” Good.

  Also, the stitching specification of the joint is not limited as long as it can reinforce the joint, and is usually selected from the sewing thread counts used for airbag stitching, for example, 2nd to 10th. May be used.

  The seam specifications according to the present invention may be selected according to the base fabric to be used, the bag specifications, the mounting site, the required joint strength, and the like. There are lock stitches, safety stitches, staggered stitches, flat stitches, etc., and these combinations may be used. Further, the number of stitch lines may be selected from 1 to 3, and when there are a plurality of stitch lines, the distance between the stitch lines may be selected from 2 to 6 mm.

  The sewing thread used in the present invention may be appropriately selected from what is generally called a synthetic fiber sewing thread or an industrial sewing thread. For example, nylon 6, nylon 66, nylon 46, polyester, vinylon, aramid, There are carbon, glass and the like, and any of spun yarn, filament twisted yarn, and filament resin processed yarn may be used.

  Moreover, the fiber yarn which comprises the textile fabric of this invention is not specifically limited, For example, the fat obtained by nylon 6, nylon 66, nylon 46, nylon 610, nylon 612 etc. individually or these copolymerization and mixing Polyamide fiber, Nylon 6T, Nylon 9T, aliphatic amine and aromatic carboxylic acid copolymerized polyamide fiber, polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, etc. Polyester fiber obtained by mixing, paraphenylene terephthalamide, and aramid fiber represented by a copolymer of this with an aromatic ether, wholly aromatic polyester fiber, vinylon fiber, ultrahigh molecular weight polyethylene fiber, polytetra Fluorocarbon fiber, polysulfone fiber, polyphenylene sulfide fiber (PPS), polyether ether ketone fiber (PEEK) fiber, polyimide fiber, polyetherimide fiber, cellulose fiber including high-strength rayon, acrylic fiber, carbon What is necessary is just to select suitably from a fiber, a glass fiber, a silicone carbide (SiC) fiber, an alumina fiber, etc., and may contain inorganic fibers, such as a metal fiber represented by steel depending on the case.

  These fiber yarns have various additives that are commonly used to improve spinnability, processability, and material durability, such as heat stabilizers, antioxidants, light stabilizers, anti-aging agents, One or more of a lubricant, a smoothing agent, a pigment, a water repellent, an oil repellent, a concealing agent such as titanium oxide, a gloss imparting agent, a flame retardant, and a plasticizer may be used. Moreover, you may give processes, such as twisting, a bulky process, a crimping process, and a winding process depending on the case. Furthermore, the form of the yarn is not particularly limited, such as filaments of long fibers, spun yarns of short fibers, and composite yarns thereof.

  It is preferable to select a thin fiber yarn having a thickness of 3 dtex or less, and by using a thin yarn of 2.5 dtex or less, the fabric becomes extremely soft and the folding volume of the airbag can be reduced. . Further, it is preferable to use a high-strength yarn having a fiber yarn strength of 7 cN / dtex or more, preferably 8 to 10 cN / dtex, in order to improve the pressure resistance and cut resistance of the airbag.

  The loom for producing the fabric of the present invention may be appropriately selected from various looms used for weaving ordinary industrial fabrics, for example, shuttle loom, water jet loom (WJL), air jet loom (AJL), rapier. You can choose from looms, projector looms, and more. The texture of the woven fabric may be plain weave, twill weave (basket weave), twill weave, lattice weave (rip-stop weave), or a composite structure thereof. A lattice weave is preferred.

  The airbag according to the present invention is a side airbag for protecting a passenger from a side impact of a vehicle, and particularly the interior of a vehicle body (a front pillar, a roof side rail portion, a center pillar portion, a rear pillar) around a side window portion. Side part that is folded in a folded state and is deployed in the form of a curtain near the side window part (from the front pillar, center pillar, or rear pillar in the passenger compartment to the roof side rail) by the gas ejected from the inflator at the time of a side collision It is a protective airbag.

  The reinforcing fabric used for reinforcing the periphery of the inflator attachment port of the airbag according to the present invention may be the same fabric as that used for the bag body, but a separately prepared reinforcing fabric, for example, nylon 66 940 dtex, One or a plurality of thick woven fabrics may be used from the airbag fabric of the present invention, prepared using 470 decitex or the like. Here, the reinforcing cloth includes a flameproof cloth for shielding the hot gas ejected from the inflator, and in order to impart heat resistance to the reinforcing cloth, a heat resistant resin such as silicone resin and fluororesin, and a heat resistant rubber. Or a woven fabric using heat-resistant fibers such as aramid fibers may be used.

  The airbag of the present invention is intended for a side airbag for side impact protection, but in some cases functions such as a headrest bag for rear-end collision protection, a mini bag for infant protection, a seat belt bag (air belt), etc. It can also be applied to a site that can be adapted to the target, and the shape, capacity, etc., should satisfy the required requirements.

Hereinafter, the present invention will be described more specifically based on examples. In the examples, performance evaluation of laminates, adhesive silicones and airbags was performed by the following methods.
(1) Difference in compression thickness between the laminate and the base fabric A laminate is prepared by overlapping the coated surfaces of the two main body base fabrics so that the coating thickness of the adhesive liner is 1 mm. After the adhesive silicone is cured, it is folded in a zigzag manner six times in the length direction of the coated portion so as to be 3 cm wide, and the load is 9.8 kpa according to JIS L-1096 (8.18 method). The difference (A−A ₀ ) in the compression thickness between the compression thickness (A) of the laminate when compressed at (100 gf / cm ² ) and the compression thickness (A ₀ ) of only the two main body base fabrics Calculated. The area of the compression terminal portion was 1 cm ² , the measurement was performed at N = 3, and the average value was shown.
(2) Physical properties of adhesive silicone a) JIS-A hardness: The hardness after curing was measured according to JIS K-6253.
b) Elongation at break: According to JIS K-6251, the initial elongation at break (E ₀ ) after curing and the elongation at break (E) after heat treatment at 100 ° C. for 250 hours were measured, and the elongation ratio (E / E ₀ ). The sample piece shape was dumbbell No. 3.
(3) Airbag deployment test The airbag was folded 10 times in a bellows shape substantially parallel to the length direction, inserted into a non-woven tubular body, and fixed to a deployment test stand. An inflator (tank pressure 150 kpa, hybrid inflator manufactured by Atlantic Research) was fixed to the inflator insertion portion together with a fixing metal fitting, and the bag was developed at room temperature. After deployment, the state of the suture layer was observed.
(4) Folding thickness of the airbag The thickness was measured in a state where the airbag was folded 10 times in a bellows substantially parallel to the length direction, and a relative comparison was made with the case of Example 2 being 100.
Example 1
Using a nylon 66 fiber 470 dtex / 72f (yarn strength 8.6 cN / dtex), a plain woven fabric having a weaving density of 18.7 yarns / cm in both warp and weft was prepared. This fabric was scoured and heat-set, and then 35 g / m ² (in terms of solid content) was applied as a heat resistant coating material on one side of the fabric, followed by drying and heat treatment to obtain a coated base fabric. The density of the woven fabric after coating was 19.3 / cm in both warp and weft, and the fabric weight was 185 g / m ² before coating and 220 g / m ² after coating.

  Next, two coating base fabrics were cut into the shape shown in FIG. 1 as the main body base fabric of the airbag. The overall size of the airbag (excluding the front hanging strap) was 165 cm in length and 55 cm in height, and the cut cloth 2 had a shape in which the central portion of the cut cloth 1 was deleted along the joining line.

  On the coated surface of the cut cloth 2, an addition type thermosetting silicone (manufactured by Shin-Etsu Chemical Co., Ltd.) having post-curing physical properties shown in Table 1 is applied as an adhesive silicone, and the coated surface of the cut cloth 1 is overlaid thereon. Further, two base cloths overlapped between two flat plates with adjusted intervals were sandwiched, and the application thickness of the adhesive silicone was 1.0 mm and the application width was 11 mm. After heating the two overlapped base fabrics at 120 ° C. for 2 minutes, as shown in FIG. The sewing thread is 5th thread with nylon 66 as the upper thread, and the 8th thread with lower thread as nylon 66. The sewing specification is double-row stitching in 2 rows (2.4mm between needles) and the number of stitches is 3.5 stitches / cm. did. The coating allowance D from the seam was 4.3 mm. Table 1 shows the characteristics of the used base fabric and airbag.

The difference in compression thickness between the laminate and the base fabric was small, the airbag could be folded compactly, and there was no damage after deployment.
Comparative Example 1
In Example 1, a laminate and an airbag were prepared in accordance with Example 1 except that SE9145 (room temperature curable condensation type silicone manufactured by Toray Dow Corning Co., Ltd.) was used as the adhesive silicone, and the characteristics were evaluated. .

  As shown in Table 1, when the hardness after curing is large and the elongation at break is small, the difference in compression thickness between the laminate and the base fabric is extremely large, and the folding volume does not decrease. Further, the sealing function of the seam was insufficient, and the adhesive silicone at the seam part was peeled and broken, and sufficient airtightness could not be obtained.

Example 2
In Example 1, nylon 66 fiber 350 dtex / 140 f (single yarn thickness is 2.5 dtex, yarn strength 9.2 cN / dtex), and the weave density is 23.2 / cm in both weft density and weft. A plain woven fabric was used, and a coated base fabric was obtained with a silicone resin coating amount of 25 g / m ² . The density of the woven fabric after coating was 24.0 pieces / cm in both the warp and the weft, and the fabric weight was 185 g / m ² before coating and 210 g / m ² after coating.

    Also, the adhesive silicone was applied to a thickness of 0.8 mm, the application width was set to about 13.5 mm, the upper and lower threads of the sewing thread were set to No. 8, and the number of moving needles was set to 4.0 needles / cm. An airbag was prepared according to Example 1, and the characteristics were evaluated. At this time, the coating allowance D from the seam was 5.5 mm.

As shown in Table 1, the difference in compressed thickness between the laminate and the base fabric was small, and the obtained airbag was excellent in compactness and had no problems after deployment.
Comparative Example 2
In Example 2, a laminate and an airbag were prepared according to Example 2 except that TSE3456T (a room temperature curable addition type silicone manufactured by GE Toshiba Silicone) was used as the adhesive silicone. went.

As shown in Table 1, as in Comparative Example 1, when the adhesive silicone is hard and the elongation at break is low, the difference in compression thickness between the laminate and the base fabric is large, the folding volume is large, and compactness is achieved. Is lacking.
Comparative Example 3
In Example 1, all except that nylon 66 fiber 470 dtex / 72f yarn was used, the woven fabric density after coating was 21.3 yarns / cm in both wefts and the silicone resin coating amount was 25 g / m ^2. Then, a laminate and an airbag were prepared and evaluated according to Example 1.

As shown in Table 1, when the fabric weight is large, the folding volume of the bag becomes large, and the object of the present invention cannot be achieved.
Comparative Example 4
In Example 1, the laminated body and the air were all in the same manner as in Example 1 except that the fabric density after coating was 16.9 pieces / cm in both the weft and the weft and the coating amount of the silicone resin was 40 g / m ^2. A bag was created and evaluated.

As shown in Table 1, when the base fabric weight is small, the folding volume of the airbag can be reduced, but the seam portion has a large seam shift, and the base fabric is broken from the seam of the circular seam.
Comparative Example 5
In Example 1, a laminate and an airbag were prepared in accordance with Example 1 except that the amount of silicone resin applied was 60 g / m ² .

  As shown in Table 1, when the coating amount of the base fabric covering material is too large, the difference in compression thickness between the laminate and the base fabric does not increase so much, but the folding volume of the bag increases, and the object of the present invention Cannot be achieved.

Explanatory drawing before the expansion | deployment which looked at the airbag of this invention from the side window part. The AA sectional view taken on the line of FIG. 1 after expansion | deployment. The outer peripheral part 3 and the oblique lines 4a and 4b indicate the adhesive layer. Explanatory drawing of the outer periphery junction part which adhere | attached and sewn the airbag. Explanatory drawing of the adhesive silicone in the outer periphery junction part of this invention. 1) shows the state before deployment, and 2) shows the state at the time of deployment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 2 Airbag body base fabric 3 Outer peripheral joint part 4a-4d of airbag main body base part Joint part 5a-5e inside main body base fabrics Inflation part 6 and 7 of a airbag The heat resistant material which coat | covered main body base cloth 8 Adhesive silicone 9 Sewing thread 10 Inflator attachment port D Adhesive silicone application allowance W from seam Adhesive silicone application width T ₀ Adhesive silicone application thickness T Between adhesive silicone application ends when airbag is inflated distance

Claims (5)

At least one side of the two body base fabrics coated with a heat-resistant material is overlapped with each other and formed into a bag shape, and the side is integrally stitched with adhesive silicone sandwiched between the overlapping portions In the airbag for a part, the base fabric has a basis weight of 210 g / m ² or less excluding the covering material, a cover factor of 750 or more, a coating amount of the covering material of 50 g / m ² or less, and When the main body base fabric and the adhesive silicone are separately formed from these layers, two sheets of the laminated body are measured at a compression thickness measured in a state where the laminate is folded 6 times according to JIS L-1096 (8.18 method). Difference (A-A) between the compression thickness (A) of the laminate in which adhesive silicone having a thickness of 1 mm is sandwiched between the main body base fabrics and the compression thickness (A ₀ ) of only two main body base fabrics ₀ ) is 25 mm or less Airbag. The adhesive silicone is a thermosetting addition-reactive adhesive silicone, having a JIS-A hardness after curing of 20 or less and an initial breaking elongation E ₀ after curing of 1400% or more. The airbag according to claim 1. The adhesive silicone has a ratio E / E ₀ between the breaking elongation E (%) and the initial breaking elongation E ₀ (%) after being heat-treated at 100 ° C. for 250 hours after curing, of 0.8 or more. The airbag according to claim 1 or 2. The airbag according to any one of claims 1 to 3, wherein the single yarn thickness of the fiber yarn constituting the main body fabric is 3 dtex or less. At least one side of the two body base fabrics coated with a heat-resistant material is overlapped with each other and formed into a bag shape, and the side is integrally stitched with adhesive silicone sandwiched between the overlapping portions In the method for manufacturing a partial airbag, a base fabric having a basis weight of 210 g / m ² or less and a cover factor of 750 or more, excluding a covering material, is used as the main body base fabric, and an addition reaction type as the adhesive silicone Using the adhesive silicone, and a thermosetting method at a temperature of 80 to 140 ° C. and a time of 5 minutes or less, and the main body base fabric and the adhesive silicone are separately laminated from these. When formed, the laminate has an adhesive property of 1 mm thickness between two body base fabrics in a compression thickness measured in a state of being folded 6 times according to JIS L-1096 (8.18 method). Airbag across the recone compression thickness of the laminate (A) and two of the main body base cloth only compressed thickness of a difference between _{(A 0) (A-A} 0) is equal to or is 25mm or less Manufacturing method.

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