JPH0834304A - Air-bag housing cover - Google Patents

Abstract

PURPOSE:To provide an air-bag housing cover being pleasant in appearance by forming it into a single layer injection molding body having a weak structure so as to be constituted by a specific constituent material so that the bending modulus of elasticity thereof denotes a specific value of physical properties. CONSTITUTION:An air-bag housing cover 1 in an air-bag device is formed by a single layer injection molding body hating a weak part 2 of a weak structure in its inside that is easily openedly broken when the air-bag device is operated, and it is constituted by a constituent material having the following components A to C, so that the bending modulus of elasticity thereof by means of JIS-K7203 denotes a value of 500 to 800kg/cm<2> of physical properties. The constituent materials are as follows: the component A is 20 to 80 parts by weight of the hydrogen additive of styrene/conjugate diene block copolymer and/or olefinic copolymer rubber; the component B is 20 to 80 parts by weight of olefinic resin; and the component C is 5 to 50 parts by weight to the total 100 parts by weight of inorganic filler, the component A, and the component B.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cover for accommodating an inflatable air bag which is activated by sensing the impact or deformation of a high-speed moving body such as an automobile in the event of a collision. Is.

[0002]

2. Description of the Related Art Conventionally, in a cover for storing an air bag in an air bag device, when the air bag is operated (expanded), the cover containing the air bag is crushed, and fragments thereof are scattered to hit the occupant's face or eyes. Since there is a risk of injury, conventional ones generally have a reinforcing material (net or the like) inserted for the purpose of preventing scattering of fragments. However, in order to manufacture an air bag storage cover containing such a net-like insert, a number of complicated manufacturing processes for inserting the net-like reinforcing material are required.

Therefore, in an attempt to solve these problems, JP-A-1-202550 and JP-A-2-171362 have been proposed.
A two-color injection-molded article comprising a skin layer made of a thermoplastic elastomer having a soft feeling and a core layer made of a hard thermoplastic resin having a shape-retaining property is proposed. Was done. As a result, there was no need to use a net-like reinforcing material, which had the effect of reducing the number of manufacturing processes, but a dedicated two-color injection molding machine was required, and two molds were used. Therefore, there remains a problem that the molding cycle is long, and that sink marks and warps due to shrinkage during molding and heating at high temperature are large.
Therefore, in order to solve this, Japanese Patent Laid-Open No.
171364, JP-A-2-151348,
JP-A-4-314648 and JP-A-5-38996.
There has been proposed a method of forming a single-layer injection-molded article as described in Japanese Patent Laid-Open Publication No.

[0004]

Therefore, according to these proposals, it becomes possible to mold the cover for storing the air bag in the air bag device by using an ordinary injection molding machine, and the molding cycle is shortened. . However, sink marks and warpage due to shrinkage at the time of molding and heating at a high temperature have not yet reached a satisfactory level.

[0005]

[Means for Solving the Problems]

[Summary of the Invention] The inventors of the present invention have conducted extensive studies to solve the above-mentioned problems, and as a result, have found that hydrogenated styrene / conjugated diene block copolymers and / or olefin-based copolymer rubbers are The present invention has been completed by finding out that a blended product of a resin and an inorganic filler makes it possible to obtain a molded product with less shrinkage and warpage due to secondary shrinkage such as shrinkage during molding and paint baking. That is, the air bag storage cover of the present invention is formed by a single-layer injection-molded body having a fragile structure for the air bag storage cover in the air bag device to be easily cleaved on the inner surface side when the air bag device is activated. And
It is composed of the constituent materials of the following components A to C, and J
The flexural modulus according to IS-K7203 is 500 to 8,000.
It is characterized in that it exhibits a physical property value of 0 kg / cm ² . Component A: Hydrogenated product of styrene / conjugated diene block copolymer and / or olefin-based copolymer rubber 20 to 80 parts by weight Component B: Olefin resin 80 to 20 parts by weight Component C: Inorganic filler Component A and components 1 to 50 parts by weight based on 100 parts by weight of the total amount of B

[Detailed Description of the Invention] [I] Airbag storage cover (1) Constituent material. The material constituting the air bag storage cover of the present invention includes a hydrogenated product of a styrene / conjugated diene block copolymer of component (A) and / or an olefin-based copolymer rubber of component (B) shown below. Olefin resin and components
It is important to use each of the essential components of the inorganic filler (C).

Component (A): Hydrogenated product of styrene / conjugated diene block copolymer and / or olefin copolymer rubber (a) Hydrogenated product of styrene / conjugated diene block copolymer Useable in the present invention A hydrogenated product of a styrene / conjugated diene block copolymer that can be obtained is one obtained by hydrogenating a block copolymer of styrene and a conjugated diene, and a preferable conjugated diene here is butadiene, isoprene or these. Is a mixture of. For example, styrene
A styrene / ethylene / butylene / styrene copolymer (SE which is a hydrogenated product of a butadiene block copolymer (hereinafter, may be simply referred to as "hydrogenated SBS").
BS), or a styrene / ethylene / propylene / styrene copolymer (a hydrogenated product of a styrene / isoprene block copolymer (hereinafter sometimes simply abbreviated as "hydrogenated S-I-S")). SEPS) and a hydrogenated product of a styrene / butadiene / isoprene block copolymer (hereinafter sometimes simply referred to as "hydrogenated S-BI-S").

The hydrogenated products of these styrene / conjugated diene block copolymers have a weight average molecular weight of 50,000-5.
0,000, preferably 60,000 to 400,000
0, particularly preferably 70,000 to 300,000, and the styrene content is 5 to 50% by weight, preferably 8 to 45% by weight, particularly preferably 10 to
It is 40% by weight, the 1,2-microstructure is less than 60%, preferably less than 45%, and the hydrogenation rate is preferably 95% or more from the viewpoint of weather resistance. . When the styrene content is less than the above range, rubber elasticity and strength tend to be poor, and when the styrene content exceeds the above range, flexibility tends to be poor. Those having a 1,2-microstructure exceeding the above range tend to have poor flexibility. Further, the JIS-A hardness according to JIS-K6301 is preferably 98 or less, preferably 95 or less, and particularly preferably 90.
It is as follows. When the conjugated diene is a mixture of isoprene and butadiene, the weight ratio of the mixture (isoprene /
Butadiene) is 99/1 to 1/99, preferably 90
/ 10 to 30/70, particularly preferably 80/20 to 40
/ 60.

Here, the "weight average molecular weight" is a polystyrene equivalent weight average molecular weight measured by gel permeation chromatography (GPC) under the following conditions. (Conditions) Equipment: 150C ALC / GPC (MILL
Column: AD80M / S (manufactured by Showa Denko KK) Three: Solvent: o-dichlorobenzene Temperature: 140 ° C. Flow rate: 1 ml / min Injection volume: 200 μl Concentration: 2 mg / ml (2 as antioxidant) 6-the-
Add 0.2% by weight of t-butyl-p-phenol. Infrared spectrophotometer MIRAN manufactured by FOXBORO
Measured at 3.42 μm wavelength with 1A. ) If the weight average molecular weight of the hydrogenated product of the styrene / conjugated diene block copolymer is less than the above range, rubber elasticity,
Mechanical strength tends to be poor, and those exceeding the above range tend to have poor moldability.

As a method for producing a hydrogenated product of these styrene / conjugated diene block copolymers, for example, the method described in Japanese Patent Publication No. 40-23798 can be used. A butadiene block copolymer was synthesized, and then, for example, Japanese Patent Publication No.
No. 2-8704, Japanese Examined Patent Publication No. 43-6636, JP-A-59.
The method described in JP-A-133203 and JP-A-60-79005 can be used to add hydrogen in the presence of a hydrogenation catalyst in an inert solvent. Further, hydrogenated S-BI-S is disclosed in, for example, Japanese Patent Laid-Open No. 3-18811.
It was synthesized by the method described in Japanese Patent No. 4 publication.

(B) Olefin Copolymer Rubber The olefin copolymer rubber that can be used in the present invention is an ethylene / propylene copolymer rubber (EP
M), ethylene / butene-1 copolymer rubber (EBM),
As non-conjugated dienes, 5-ethylidene norbornene, 5
Examples thereof include ethylene / propylene / non-conjugated diene copolymer rubber (EPDM) using methylnorbornene, 5-vinylnorbornene, dicyclopentadiene and the like. The manufacturing method and shape of these olefin-based copolymer rubbers are not particularly limited. Further, those obtained by heat-treating them in the presence of organic peroxide and crosslinking mainly by radicals may be used. These olefin copolymer rubbers have a weight average molecular weight of 50,000 to 1,
, 000,000, preferably 60,000 to 800,000
00, particularly preferably 80,000 to 500,000,
Propylene content is 10-60% by weight, preferably 15-
55% by weight, Mooney viscosity ML _{1 + 4} (100 ° C) is 5
It is preferred to use ˜350, preferably 10-300, copolymer rubber. If the weight average molecular weight of the olefin-based copolymer rubber is less than the above range, rubber elasticity and mechanical strength tend to be poor, and if the weight average molecular weight exceeds the above range, moldability tends to be poor.

Component (B): Olefin Resin The olefin resin of component (B) used in the present invention is a propylene resin, an ethylene resin, a crystalline polybutene-1 resin, an ethylene / vinyl acetate copolymer, ethylene. Examples thereof include ethylene-based resins such as (meth) acrylic acid copolymers and ethylene (meth) acrylic acid ester copolymers. Among these olefin resins, it is preferable to use a propylene resin, and particularly preferably,
Melt flow rate (JIS-K6758, 230 ° C,
2.16 kg load) is 0.01 to 100 g / 10 minutes, preferably 0.05 to 80 g / 10 minutes, particularly preferably 0.1 to 60 g / 10 minutes, and the ethylene content is 0 to 15% by weight, preferably 0 to 13% by weight, particularly preferably 0 to
It is a propylene resin in the range of 10% by weight. The ethylene content here is a value measured by an infrared spectrum analysis method or the like.

The propylene resin is a propylene homopolymer or a copolymer resin containing propylene as a main component, and specific examples thereof include propylene / ethylene random copolymer and propylene / ethylene block copolymer. be able to. If a melt flow rate lower than the above range is used, the injection moldability tends to deteriorate, and the appearance of the obtained injection molded article, particularly the generation of flow marks, tends to be remarkable. Further, when a melt flow rate exceeding the above range is used, the material strength tends to decrease.

Examples of the ethylene resin include a low density polyethylene resin (branched ethylene polymer) produced by a high pressure method and a high density polyethylene which is an ethylene homopolymer obtained by a medium- and low-pressure method, produced by a conventional method. Resin (linear ethylene polymer) or low density which is a copolymer of ethylene and α-olefin obtained by the medium- and low-pressure method,
Examples thereof include medium-density and high-density polyethylene resins (linear ethylene polymers). The linear α-olefin that is the comonomer includes butene-1, pentene-1,
Hexene-1,4-methylpentene-1, octene-1
And the like, which may be used in combination of two or more. As specific manufacturing conditions, generally, a pressure of 5 to
A method of copolymerizing ethylene and α-olefin under a condition of 2,500 kg / cm ² and a temperature of 50 to 300 ° C. using a catalyst such as a Ziegler type catalyst, a vanadium type catalyst and a Kaminsky type catalyst is adopted. Specifically, Japanese Patent Publication Sho 56
The method described in Japanese Patent Publication No.-18132 is known.

The crystalline butene-1 resin is a crystalline resin synthesized from butene-1 monomer which may contain a small amount (20% by weight or less) of other comonomers such as ethylene and propylene, and has a density of 0.890 to 0.925
g / cm ³ , preferably 0.893 to 0.923 g / c
m ³ , particularly preferably 0.900 to 0.920 g / cm
³ , melt flow rate (MFR: 190 ℃, 2.16
(kg load) is 0.01 to 1,000 g / 10 minutes, preferably 0.05 to 500 g / 10 minutes, and particularly preferably 0.1.
1 to 100 g / 10 minutes, crystallinity of 30% or more, preferably 30 to 70%, weight average molecular weight of 10,000 to
3,000,000, preferably 50,000-2,5
Those of 0,000 are preferably used.

Component (C): Inorganic filler As the inorganic filler of the component (D) used in the present invention, talc, mica, glass fiber, whiskers, carbon fiber, calcium carbonate, glass balloon and the like can be mentioned. Among these, it is preferable to use plate-like inorganic fillers such as talc and mica, and fibrous inorganic fillers such as glass fibers, whiskers, and carbon fibers in terms of shrinkage, warpage due to shrinkage, and sink marks.

A preferred talc has a specific surface area of 3
7,000 cm ² / g or more, preferably 40,000 c
m ² / g or more, length is substantially 15 μm or less, preferably 10 μm or less, average particle size is 1.0 to 6.0 μm, preferably 1.5 to 5.0 μm, and average aspect ratio is 5
Or more, preferably 6 or more. Here, "substantially" the length of talc means that most talc particles are in this range. Talc is produced, for example, by crushing raw talc with an impact type crusher or a micron type crusher, further finely crushing it with a micron mill or jet type crusher, and then classifying and adjusting it with a cyclone or a micron separator. Here, the measurement of the average particle size is a value measured using a laser light scattering type particle size distribution meter, and as such a measuring device, for example, LA-500 manufactured by Horiba Ltd. has excellent measurement accuracy. desirable. The diameter, length and aspect ratio are values measured by a microscope or the like.

Component (D): Hydrocarbon-based rubber softening agent The hydrocarbon-based rubber softening agent used as an additional component in the present invention has a weight average molecular weight of 300 to 2,
000, preferably 500-1,500 are suitable. Such a hydrocarbon-based softening agent for rubber is generally a mixture of an aromatic ring, a naphthene ring, and a paraffin ring, and has a paraffin chain carbon number of 50% or more of the total carbon. It is called a paraffin oil, and one having a naphthene ring carbon number of 30 to 45% is called a naphthene oil, and one having an aromatic carbon number of more than 30% is called an aromatic oil. Among these, it is preferable to use paraffinic oil from the viewpoint of weather resistance. The paraffinic oil used in the present invention has a kinematic viscosity at 40 ° C. of 20 to 800 cst, preferably 5
0 to 600 cst, fluidity 0 to -40 ° C, preferably 0 to -30 ° C, and flash point (COC) 200 to 40
Oils at 0 ° C, preferably 250-350 ° C are preferably used. Hydrocarbon-based rubber softeners include Component A and Component B
It is suitable to add 1 to 50 parts by weight, preferably 1 to 40 parts by weight, and particularly preferably 1 to 30 parts by weight to 100 parts by weight of the total amount. The hydrocarbon-based rubber softening agent is important for adjusting the hardness and the melt fluidity during molding.

Component (E): Additional compounding agent The compounding material of the cover for accommodating the air bag of the present invention may contain any compounding ingredient according to various purposes within a range that does not significantly impair the effects of the present invention. can do. Specifically, various thermoplastic resins, various elastomers, various plasticizers, antioxidants, heat stabilizers, light stabilizers, ultraviolet absorbers, neutralizing agents, lubricants, antifog agents, antiblocking agents, slip agents, Various additives such as cross-linking agents, cross-linking aids, colorants, flame retardants, dispersants, antistatic agents, conductivity-imparting agents, metal deactivators, molecular weight regulators, antibacterial agents, and optical brighteners. be able to.

Examples of the thermoplastic resin include styrene resins such as polystyrene, acrylonitrile / styrene copolymer, acrylonitrile / butadiene / styrene copolymer, polyphenylene ether resin, polyamide resins such as nylon 6 and nylon 66, polyethylene. Polyester resin such as terephthalate and polybutylene terephthalate, polyoxymethylene resin such as polyoxymethylene homopolymer and polyoxymethylene copolymer,
Examples thereof include polymethylmethacrylate resin. The thermoplastic resin used may be one kind or a mixture of plural kinds.

(2) Mixing ratio The mixing ratio of each component of the material constituting the cover for accommodating the air bag of the present invention is 20 to 80% by weight of the total amount of the component A and the component B, preferably the component A. 25 to 75% by weight, particularly preferably 30 to 70% by weight. If the blending ratio of the component A is less than the above range, the low-temperature impact resistance of the obtained cover will be poor. That is, the developability at low temperature is poor, and when it exceeds the above range, the developability at high temperature becomes poor. Further, the mixing ratio of the component B is 80 to 20% by weight, preferably 75 to 25% by weight, and particularly preferably 70 to 30% by weight based on the total amount of the components A and B. If it exceeds the above range, low temperature impact resistance is poor, that is, the developability at low temperature is poor, and if it is less than the above range, developability at high temperature becomes poor. Further, the component C is 1 to 50 parts by weight, preferably 1 to 40 parts by weight, particularly preferably 1 to 30 parts by weight, based on 100 parts by weight of the total of the components A and B. Therefore, if the amount is less than 1 part by weight, the moldability, particularly warpage and rib sinkage are conspicuous, and the shrinkage becomes poor. If the blending amount of the component C exceeds the above range, the low temperature impact resistance is poor, that is, the developability at low temperature becomes poor.

[II] Molded Product A molded product of the present invention molded from the above-mentioned components is a single-layer injection molded product having a fragile structure on the inner surface side for easily cleaving when the air bag device operates. JIS-K
Bending elastic modulus according to 7203 is 500 to 8,000 kg /
cm ² , preferably 500 to 7,000 kg / cm ² ,
An air bag storage cover having a weight of 500 to 6,500 kg / cm ² is preferable. Specifically, FIG. 1 and FIG.
Also, the shape as shown in FIG. 3 can be exemplified. Reference numeral 1 is a cover for storing an air bag.
Is provided with ribs 1b and 1c for attaching to a container portion for accommodating an air bag on the back surface side of the flat plate portion 1a.
An attachment hole 3 is formed in b for fixing the container portion to the container with rivets, bolts or the like. A fragile portion 2 is formed on the flat plate portion 1a for easy tearing when the air bag device is operated, and when the air bag device is operated, a part of the air bag storage cover 1 is opened to inflate the air bag. You can do it.

As a method of manufacturing such a cover for storing an air bag, an ordinary injection molding method can be used,
If necessary, various molding methods such as gas injection molding method and short-sit foam molding method can be used. If the flexural modulus is less than the above range, the strength of the mounting portion is poor, especially at high temperatures, and there is a problem in air bag deployability. If it exceeds the above range, the air bag spreadability at low temperature becomes poor. The injection molding condition is generally 100
A molding temperature of ~ 300 ° C, preferably 150-280 ° C,
50-1,000 kg / cm ³ , preferably 50-8
Molding is carried out at an injection pressure of 00 kg / cm ^{3 and} a mold temperature of 20 to 80 ° C., preferably 20 to 60 ° C. Furthermore, the average thickness of the air bag storage cover of the present invention is 1 to 5 mm. However, it is necessary to provide a fragile structure for easy cleavage when the airbag device is activated, and the wall thickness of the cleavage portion should be designed thin, preferably 50% or less of the average wall thickness. Appropriate.

[III] Coating The coating is preferably applied to the surface of the cover of the present invention for the purpose of designing the interior of the coating chamber or for the purpose of preventing dust and dirt from sticking and preventing scratches. As this coating, various kinds of coatings conventionally applied to this type of cover can be used.

[IV] Usage The thus obtained air bag storage cover of the present invention operates by sensing the impact or change of a high speed moving object such as an automobile when a collision accident occurs. , A cover for accommodating an inflatable airbag. Specifically, it is an air bag storage cover used for a driver's seat, a passenger seat, a rear seat, etc. of an automobile.

[0026]

EXAMPLES In order to explain the air bag storage cover of the present invention in more detail, experimental examples will be described below in detail. [I] Raw Materials In the Examples and Comparative Examples, the following raw materials were used.

[0027]

[Table 1]

[0028]

[Table 2]

[0029]

[Table 3]

[0030]

[Table 4]

[0031]

[Table 5]

[II] Evaluation Method Various evaluations in these Examples and Comparative Examples were carried out by the following methods. However, the measurement samples in (1) to (3) were measured using an in-line screw type injection molding machine (Toshiba Machinery Co., Ltd. small injection molding machine: IS170) with an injection pressure of 500 kg / cm ² and an injection temperature of 210 ° C.
120 mm x 120 mm x 3 mm at a mold temperature of 40 ° C
A sheet molded to the size of was used. Also, (4) ~ (5)
In-screw type injection molding machine (Toshiba Machinery Co., Ltd. small injection molding machine: IS22)
0) was used to evaluate with a cover for storing an air bag molded at a temperature of 220 ° C. into the shape shown in FIGS. 1, 2 and 3.

(1) Flexural modulus (kg / cm ² ): JI
Conforms to SK-7203 (2) Shrinkage rate after heating: Writing line (100
(mm interval) 120 mm x 120 on the design surface of the mold
After heating a mm × 3 mm sheet in an oven (120 ° C. × 1 hour) and allowing it to cool, the distance between the writing lines on the molded sheet is measured, and the shrinkage rate after heating is calculated by the following formula. Was determined by the following criteria. Criteria ○: Shrinkage after heating (%) ≦ 2 ×: Shrinkage after heating (%)> 2

(3) Formability (Warp and Rib Marking Conspicuousness) In the cover molded body, the degree of easiness of warping and rib sinking is visually observed. did. (4) Deployment test Deploy the airbag device set with the airbag device and the storage cover to the deployment test temperature (-40 ° C, 80 ° C).
After being left in a constant temperature bath (° C.) For 1 hour, a development test was performed. When the cover breaks and scatters, or it breaks into a sharp shape and cannot be normally deployed, or when it is torn off from the mounting portion, it is regarded as a defect, and the above-mentioned problems do not occur and the cover is deployed. Was considered good.

[III] Experimental Examples Examples 1 to 18 and Comparative Examples 1 to 6 The raw materials shown in Tables 1 to 5 were used and blended in the blending composition (parts by weight) shown in Tables 6 to 8. 0.1 parts by weight of a phenolic antioxidant (trade name "Irganox 1010") was added to 100 parts by weight of the total composition shown in 8, and the mixture was prepared in advance using a Banbury mixer at a temperature of 170 ° C. After kneading for a minute, the sheet was cut to obtain pellets, which were melt-kneaded at a temperature of 200 ° C. with a twin-screw extruder having L / D = 33 and a cylinder diameter of 45 mm to obtain TPE composition pellets. The pellets were injection-molded as described above into a sheet and evaluated as described above. The evaluation results are shown in Tables 6-8. Further, in Example 18, when the total amount of the blended composition shown in Table 7 was 100 parts by weight at the time of melt kneading,
Phenolic antioxidant (trade name "IRGANOX 10
10 "), and 0.1 part by weight of 2,5-dimethyl-2,5-di (t-butylperoxy) hexane-3 (trade name" Kayahexa AD ") as a peroxide.
3 parts by weight, 0.2 parts by weight of divinylbenzene as a crosslinking aid are added, and the heat treatment (crosslinking treatment) is performed by setting the temperature to 220 ° C. with a twin-screw extruder with L / D = 33 and a cylinder diameter of 45 mm. A partially crosslinked TPE composition pellet was obtained. The pellets were injection-molded as described above into a sheet and evaluated as described above. The evaluation results are shown in Table 7.

[0036]

[Table 6]

[0037]

[Table 7]

[0038]

[Table 8]

[0039]

The cover for storing an air bag of the present invention comprises:
Molding can be performed using an ordinary injection molding machine, and molding can be performed with a shortened molding cycle. Furthermore, since sink marks and warps due to shrinkage during molding and high temperature heating are small, it is a good-looking molded article. Therefore, it is industrially very useful as a cover for accommodating an air bag that is inflated and deployed by sensing the impact or deformation of the high speed moving body such as an automobile in the event of a collision.

[Brief description of drawings]

FIG. 1 is a perspective view of an air bag storage cover according to an embodiment of the present invention.

2 is a view A- of the air bag storage cover of FIG.
FIG.

FIG. 3 is B- of the airbag storage cover of FIG.
It is B sectional drawing.

[Explanation of symbols]

 1 Air bag storage cover 1a Flat plate part 1b Rib 2 Weak part 3 Mounting hole

Continuation of front page (51) Int.Cl. ⁶ Identification number Office reference number FI Technical display area C08L 53/02 LLV LLY

Claims (3)

[Claims] 1. A cover for accommodating an air bag in an air bag device is formed by a single-layer injection-molded article having a fragile structure on the inner surface side for easily tearing when the air bag device is operated. A cover for storing an air bag, which is made of the constituent material of component C and has a flexural modulus according to JIS-K7203 of 500 to 8,000 kg / cm ² . Component A: Hydrogenated product of styrene / conjugated diene block copolymer and / or olefin-based copolymer rubber 20 to 80 parts by weight Component B: Olefin resin 80 to 20 parts by weight Component C: Inorganic filler Component A and components 1 to 50 parts by weight based on 100 parts by weight of the total amount of B 2. A constituent material of a cover for storing an air bag,
The air bag storage cover of the air bag device according to claim 1, which comprises the following component D. Component D: Hydrocarbon-based rubber softening agent 1 to 50 parts by weight based on 100 parts by weight of the total amount of components A and B. 3. The air bag storage cover of the air bag device according to claim 1, wherein the surface of the air bag storage cover is coated.