KR100508831B1 - Thermoplastic polyetherester elastomer composition and cover for air-bag device thereby - Google Patents

Abstract

The present invention relates to a polyether ester block copolymer containing 10 to 90% by weight of a low hardness polyether ester block copolymer having a Shore hardness of 40 to 50 D in a thermoplastic polyether ester elastomer resin composition mainly composed of a polyether ester block copolymer. A thermoplastic elastomer composition comprising a combination of 90 to 10% by weight of a high hardness polyetherester block copolymer of 50 to 63D, which maintains flexibility, moldability and scratch resistance, and is particularly used as a vehicle airbag cover device. It has excellent development characteristics.

Description

Thermoplastic polyetherester elastomer composition and cover for air-bag device manufactured therefrom

The present invention relates to a polyether ester elastomer resin composition excellent in durability in order to minimize the mechanical properties of the resin product due to aging that can occur during processing or use, and more specifically to a vehicle airbag cover manufactured therefrom. The present invention relates to a polyetherester thermoplastic elastomer resin composition and a vehicle airbag cover manufactured therefrom that can be applied to interior materials of various mechanical parts including a vehicle airbag device cover and a power line coating, a hose, a shock absorber, and the like used for a long time at a high temperature.

Polyester elastomer refers to a thermoplastic elastic material having an ester-type chain structure, showing the same flexibility and resilience as the general vulcanized rubber, but in moldability, polyethylene, a general thermoplastic material without the vulcanization process of manufacturing a conventional vulcanized rubber It is a material having an intermediate property of rubber and plastic, which can be manufactured by a molding process such as polypropylene, polyamide, polyester, and the like.

In general, in the case of vulcanized rubber, low-viscosity rubber raw materials manufactured by natural or artificial synthesis are molded by vulcanization. These materials show excellent flexibility and elastic recovery, but the molding process is very complicated and poor in stability. In addition, there is a problem in recycling because it is a thermosetting material, and there has been a demand for the development of a new material that improves these problems. In order to meet these demands, various types of thermoplastic elastomers such as urethane, olefin, and amide have been developed, including styrene, which was first developed as a thermoplastic elastomer (TPE).

Among them, polyester thermoplastic elastomer is a relatively recently developed material compared to other materials, and is generally known to be superior to other thermoplastic elastomers in terms of performance and stability, but recently, it has long term such as durability and weather resistance required for various uses. The level of use characteristics is only getting higher. In particular, durability is one of the most important properties because it plays a major role in the properties of the material as well as in the production and processing of thermoplastic elastomer materials, as well as when used in each application.

As an example of the use of the thermoplastic elastomer whose durability is important, the cover for an airbag apparatus is mentioned. In principle, the airbag system includes an impact sensor and an airbag device that adds to the impact of a high speed vehicle. The airbag device is connected to the airbag and the airbag accommodated in the cavity installed in the front of the driver's seat and the driver's seat in the high-speed traveling body, an inflator for inflating the airbag, an airbag in the cavity, a retainer for holding the inflator and a cover to be described later; And a cover for protecting the opening of the cavity in which the airbag, the inflator and the retainer are housed. There is no particular limitation on the shape of the cover, but there may be a difference in the feeling felt by the occupant and the airbag deployment characteristics during a vehicle crash depending on the material used.

In principle, the airbag system works as follows; In the event of a collision, the impact sensor detects the collision, and then the ignition agent in the inflator is electrically or mechanically ignited. Heat is generated by the ignition action, and gas is generated by burning the gas generating agent. The generated gas is contained in the cavity, which is the space between the retainer, the inflator and the cover, and inflates the airbag by filling the folded airbag. By the pressure of the inflating airbag, the cover cracks and expands at a predetermined position to form an opening, which causes the airbag to be instantaneously released and expands toward the occupant front. The inflated airbag acts as a shock absorber and can prevent the occupant from injuring the collision with the drive. Thus, the airbag cover is essential to the airbag apparatus, and in the event of a crash and actuation of the airbag system's outgassing, the cover is securely deployed without debris that could injure the occupant, enabling immediate airbag release and inflation.

In order to prevent debris during airbag cover deployment, Japanese Patent Application Laid-Open Nos. 50-127336 and 55-110643 propose airbag cover constructions comprising a reinforcing net made of nylon. This type of cover advantageously prevents undesired cracking of the cover and scattering of the broken fragments of the cover at locations other than the prescribed position when the cover is opened, but is added to wrap the net in the cover. Productivity is low because it requires time and the wrapped net is easy to come out of a fixed position.

Japanese Patent Application Laid-open No. Hei 1-202550 discloses a cover for an airbag apparatus comprising a surface layer made of a soft material having a JIS K 6301 A hardness of 30 to 70 and a core layer made of a hard resin having elasticity and a slit for developing the cover. It is starting. The cover has a certain degree of adherence and imparts adequate soft feel to the occupant but it is necessary to carry out double layer molding to form the core layer and the surface layer, so that the cover has a double injection molding machine having two separate injection mechanisms. There is a necessary disadvantage. In addition, this type of cover has the disadvantage that the scratch resistance of the soft material used to form the surface layer is poor, it is necessary to paint the surface of the cover obtained by double-layer molding, with the problem of increased production cost have.

Japanese Patent Laid-Open No. 6-200086 discloses a thermoplastic elastomer composition containing a hydrogenated block copolymer, a polyolefin resin, paraffin oil and rubber. Hydrogenated block copolymers used in elastomer compositions tend to have poor moldability of the compositions, including polymer blocks having a high number average molecular weight. In order to avoid such poor moldability, it is necessary to increase the amount of paraffin oil and rubber, but this causes a problem that the cover for the airbag apparatus has an unsatisfactory scratch resistance.

As an example of the prior art for overcoming the above disadvantages of the polyolefin-based thermoplastic elastomer, U.S. Patent No. 4,895,389 introduces a method of manufacturing a cover of excellent performance using a polyester ether elastomer, Description of the structural design is the main content, there is no specific reference to the characteristics of the product material and its composition. In addition, although US Patent No. 6,027,818 states that a claim for an air bag device cover is included as an important use of an epoxy compound-added polyester ether elastomer, the characteristics of the air bag device cover are insufficient in the text. The composition presented here is a composition that is applied to extremely general applications and has a weak point to be applied to a cover for an automobile airbag device, particularly in terms of durability.

As an example of an attempt to improve the durability of the polyester ether elastomer, for example, tris (hydroxybenzyl) cyanurate type stabilizer which is a hindered phenol-based first stabilizer generally known in the United States Patent No. 3,723,427 Suggested. In addition, US Pat. No. 3,758,579 proposes a thioester secondary stabilizer and mentions a method of mixing with a phenolic primary stabilizer, and then synergistic effect by mixing such primary and secondary stabilizers. It can be seen that similar techniques have been used in many places, such as US Pat. Nos. 3,996,675 and 4,414,408, to improve the stability by causing the stability. Among them, U.S. Patent No. 4,069,200 discloses 6-tertiary-butyl-2,3-dimethyl-4- (dimethylaminomethyl) -phenol and 6-tertiary-octyl-2,3-dimethyl-4- (dimethylaminomethyl ) -Phenol, 6-tertiary-butyl-4- (dimethylaminomethyl) -5,6,7,8-tetrahydro-1-naphthol, 5-tertiary-butyl-2,3-dimethyl-4-hydro To improve the durability of the polyolefin resin by using a hindered phenolic primary stabilizer such as oxybenzylphosphonate alone or a thioester secondary stabilizer such as dilaurylthiodipropionate or distearylthiodipropionate. In US Pat. No. 4,185,003, N, N`-hexamethylenebis (3,5-di-tert-butyl-4-hydroxyhydrocinamide (N, N`-hexamethylenebis (3,5-di-t -butyl-4-hydroxyhydrocinnamamide), N, N`-trimethylenebis (3,5-di-tertiary-butyl-4-hydroxyhydrocinamide) (N, N`-trimetylenebis (3,5-di-t -butyl-4-hydroxyhydrocinnama phenolic antioxidants such as mide) and bis (1,2,2,6,6-pentamethyl-4-piperidinyl) -n-butyl- (3,5-di-tertiary-butyl- 4-hydroxybenzyl) malonate {bis (1,2,2,6,6-pentamethyl-4-piperidinyl) -n-butyl- (3,5-di-t-butyl-4-hydroxybenzyl) malonate}, Bis (2,2,6,6-tetramethyl-4-piperidinyl) bis (3,5-di-tert-butyl-4-hydroxybenzyl) malonate {bis (2,2,6,6 stability of copolyetherester by mixing hindered amine photostab ilizer such as -tetramethyl-4-piperidinyl) bis (3,5-di-t-butyl-4-hydroxybenzyl) malonate} US Pat. No. 4,405,749 discloses 1,3,5-tris- (2-hydroxyethyl) -s-triazine-2,4,6- (1H, 3H, 5H) trione {1, 3,5-tris-2-hydroxyethyl) -s-triazine-2,4,6- (1H, 3H, 5H) trione} and 3,5-di-tert-butyl-4-hydroxyhydrocinnamic acid { Using ester compounds of 3,5-di-t-butyl-4-hydroxy hydrocinnamic acid} Attempts have been made to improve the stability of polyester resins. In addition, Japanese Patent Publication No. 88-38371 proposes a method for preparing a stabilizer having a high dimer content of 2,2,4-trimethyl-1,2-dihydroquinoline, and Japanese Patent Publication No. 88- 40817 describes a method of mixing and using 2,2,4-trimethyl-1,2-dihydroquinoline type compounds and phenothiazine type compounds in Japanese Patent Application No. 88-40819. We propose a method of improving stability by using a mixture of 2,4-trimethyl-1,2-dihydroquinoline type mercapto compounds such as 2-mercaptobenzoimidazole or 2-mercaptomethylbenzoimidazole. have.

However, in the case of polyetherester thermoplastic elastomers, unlike polyethylene terephthalate or polybutylene terephthalate resin, when the thermal decomposition occurs, the polyol portion, which is a soft segment, is first decomposed by formic acid. Acceleration of action occurs, and capturing of formic acid is necessary to prevent this. Mainly, such capturing is possible by materials having basic acidity of constituent molecules, but amine-based stabilizers among basic materials have excellent heat resistance, but have a problem of deteriorating initial color of a product.

As described above, polyester thermoplastic elastomer is a relatively recently developed material compared to other materials and is generally known to be superior to other thermoplastic elastomers in terms of performance and stability. It is only one of the most important long-term use characteristics, because the level is only going up, and especially durability, because it plays a major role in the properties of the material not only in the production and processing of thermoplastic elastomer materials, but also when used in each application.

Therefore, the inventors of the present invention have been using various stabilizers of various conventionally proposed to improve the durability while using a mixture of low hardness and high hardness as a polyether ester block copolymer to improve the durability, in particular vehicle air bag Nuclear agent and other additives are included to improve the development characteristics when used in the cover of the device, and as a result, all the objectives including flexibility, low temperature characteristics, weather resistance, mechanical strength, molding processability, etc., while sufficiently improving the durability of the material It was found that the present invention can provide a thermoplastic elastomer composition having excellent properties.

In addition, it has been found that when a molded article is manufactured using such an elastomeric composition, it is possible to provide a cover for releasably maintaining an airbag device exhibiting not only inherent properties of the thermoplastic elastomer composition itself but also excellent deployment characteristics. The invention was completed.

Accordingly, an object of the present invention is to provide a polyether ester thermoplastic elastomer resin composition for minimizing the degradation of the mechanical properties of the resin due to aging caused by lack of durability.

It is also an object of the present invention to provide a cover for a vehicle airbag apparatus molded from such a polyetherester thermoplastic elastomer resin composition and having excellent development characteristics.

The polyetherester thermoplastic elastomer of the present invention for achieving the above object is a polyetherester block copolymer as a main component, the polyetherester block copolymer is a low hardness polyetherester block having a Shore hardness of 40 ~ 50D Alkali metal salt nucleating agent and stabilizer of phosphate having a bisphenyl ligand represented by the formula (3) as a combination of 10 to 90% by weight of the copolymer and 90 to 10% by weight of the high hardness polyether ester block copolymer having a Shore hardness of 50 to 63D. Characterized in that it further comprises. Wherein R ₁ and R ₂ are each C ₂ to C ₂₀ aliphatic, aromatic and cyclic hydrocarbon radicals, and M is an alkali metal such as Li, Na, K having a monovalent charge.

Such a composition can be applied to interior materials of various mechanical parts, including covers for vehicle airbag devices, and all fields requiring excellent durability, such as coating of power lines, hoses, and shock absorbers, which are used for a long time at high temperatures.

The present invention will be described in more detail as follows.

The present invention relates to a polyetherester thermoplastic elastomer resin composition and a vehicle airbag device cover composition prepared therefrom having minimized degradation of mechanical properties due to aging.

The main component of the polyether ester elastomer resin composition of the present invention is a thermoplastic polyether ester block copolymer having a structure in which a hard segment represented by the following formula (1) and a soft segment represented by the following formula (2) are alternately repeated.

Wherein D is a radical from which two hydroxy groups are removed from C ₂ to C ₈ saturated aliphatic diols and cyclic diols alone or in a mixture of two or more, and R is an aromatic, aliphatic and cyclic dicarboxylic acid having a molecular weight of 500 or less It is a radical with two carboxyl groups removed alone or in a mixture of two or more.

Wherein G is a polyether glycol having a molecular weight of 400 to 4000 alone or a mixture of two or more thereof, wherein two hydroxy groups have been removed and R is as defined above.

In the present invention, among the polyether ester block copolymers having the above structure, 10 to 90% by weight of the low hardness polyether ester thermoplastic elastomer resin having a Shore hardness of 40 to 50D and a high hardness polyether ester thermoplastic having a Shore hardness of 50D to 63D 90-10 weight% of elastomer resins are used in combination, and molecular weight distribution is distributed in the range of 2.0-2.5.

Specifically, the main component is a polyetherester thermoplastic elastomer resin obtained by mixing a low hardness polyetherester thermoplastic elastomer resin and a high hardness thermoplastic elastomer resin in a mixer for about 1 hour.

If the content of the high hardness thermoplastic elastomer resin is less than 10% by weight of the polyetherester thermoplastic elastomer resin content, the deployment of the vehicle airbag cover device may not occur parallel to the deployment break line when the vehicle airbag cover device is deployed. The touch of the cover portion of the cover device becomes hard, and there may be a problem in that the entire cover is separated from the device without the side-by-side deployment occurring on the deployment break line when the vehicle airbag cover device is deployed.

Similarly, if the content of the low hardness thermoplastic elastomer resin is less than 10% by weight of the polyetherester thermoplastic elastomer resin, the feel of the vehicle airbag cover device becomes very hard, and if it exceeds 90% by weight, the ideal development parallel to the development break line does not occur. There can be.

In addition, in the present invention, in order to improve the durability of the polyetherester thermoplastic elastomer resin, in particular, in order to improve the development characteristics when used in a vehicle airbag device cover, the polyetherester block copolymer having a bisphenyl ligand as a nucleating agent is used. Alkali metal salts of phosphate are added.

The alkali metal salt of phosphate having a bisphenyl ligand is a compound having a structure represented by Chemical Formula 3, specifically, in the present invention, sodium 2,2'-methylene-bis- (4,6- Di-tert-butylphenyl) phosphate [sodium-2,2'-methylene-bis- (4,6-di-tert-butylphenyl) phosphate] as nucleating agent.

This acts as a nucleating agent to increase the rate of crystallization during product processing and has the effect of reducing the size of the crystal. In addition, by expanding the microcrystalline structure in the resin composition to minimize the decomposition reaction occurring in the soft segment vulnerable to aging phenomenon to transition to the neighboring segment, while maximizing the phase separation between the segment and the soft segment, the elastic recovery power and the responsiveness of the resin composition To improve.

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In the thermoplastic elastomer composition of the present invention, the content of sodium 2,2'-methylene-bis- (4,6-di-tert-butylphenyl) phosphate is preferably 0.05 to 3.5 based on 100 parts by weight of the polyether ester block copolymer. Part by weight, more preferably 0.2 to 0.6 part by weight. If the content is less than 0.05 parts by weight with respect to 100 parts by weight of the polyether ester block copolymer, the deployment response is poor. If the content is more than 3.5 parts by weight, the entire cover area of the vehicle airbag cover device becomes harder than necessary, and before breaking There may be a problem where no parallel developments occur.

Meanwhile, in the composition of the present invention, when the sodium 2,2'-methylene-bis- (4,6-di-tert-butylphenyl) phosphate is further included in addition to the other stabilizer, it causes a synergistic effect of durability and excellent durability. It can be more effective.

Other stabilizers that can be used with sodium 2,2'-methylene-bis- (4,6-di-tert-butylphenyl) phosphate include 2,2'-m-phenylene bis (2-oxazoline) [2 , 2′-m-phenylene bis (2-oxazoline)], 4,4′-bis (α, α-dimethylbenzyl-disphenylamine) [4,4′-bis (alpha, alpha-dimethylbenzyl diphenylamine)], N, N'-hexane-1,6-diyl bis (3- (3,5-di-tert-butyl-4-hydroxyphenyl-propionamide [N, N'-hexane-1,6-diyl bis ( 3- (3,5-di-tert-butyl-4-hydroxyphenyl propionamide)] is preferably one or a mixture of two or more selected from the group consisting of.

2,2'-m-phenylene bis (2-oxazoline) is represented by the following formula (5), 4,4'-bis (α, α-dimethylbenzyl-disphenylamine) is represented by the following formula (6), N, N′-hexane-1,6-diyl bis (3- (3,5-di-tert-butyl-4-hydrocyphenyl-propionamide) is as represented by the formula (7).

When a stabilizer system comprising sodium 2,2'-methylene-bis- (4,6-di-tert-butylphenyl) phosphate represented by Formula 4 and other stabilizers represented by Formulas 5 to 7, is used, Their content is 0.2 to 0.6 parts by weight of sodium 2,2'-methylene-bis- (4,6-di-tert-butylphenyl) phosphate relative to 100 parts by weight of polyetherester block copolymer, and other stabilizers 0.1 to 3.0. Weight part is preferable.

More preferably, the stabilizer system comprises 0.3 to 0.5 parts by weight of sodium 2,2'-methylene-bis- (4,6-di-tert-butylphenyl) phosphate based on 100 parts by weight of polyetherester block copolymer. 0.1-1.0 part by weight of '-m-phenylene bis (2-oxazolcin), 0.1-1.0 part by weight of 4,4'-bis (α, α-dimethylbenzyl disphenylamine), N, N'-hexane-1 It is effective to add, 6-diyl bis (3- (3,5-di-tert-butyl-4-hydroxyphenyl propionamide in a ratio of 0.1 to 1.0 parts by weight).

In order to increase the durability of the polyether ester thermoplastic elastomer, the above-mentioned stabilizers must be mixed to meet the properties of the resin. In the present invention, the synergistic effect of the durability of the polyether ester thermoplastic elastomer is added by adding the stabilizer system at the above ratio. It is possible to secure the deployment stability of the cover for the vehicle airbag device for a long time use.

Among the additives, N, N′-hexane-1,6-diyl bis (3- (3,5-di-tert-butyl-4-hydrophenylphenyl propionamide) serves to trap active radicals generated by heat. While showing proper heat resistance, it has the advantage of hardly deteriorating the initial color.

Of the additives of the present invention, 2,2'-m-phenylene bis (2-oxazolcin) and 4,4'-bis (α, α-dimethylbenzyl disphenylamine) have the effect of being used alone. Although not sufficient, synergistic effect is achieved when used together in the same amount, especially 2,2'-m-phenylene bis (2-oxazolcin) is the aging phenomenon of the polyether ester block copolymer resin. It acts as a decomposer for the peroxides that occur in, while also acting as a capturing agent for formic acid, which occurs in the decomposition of soft segments.

When using such a stabilizer system, durability of about 20 times more than the basic composition containing no additional stabilizer was achieved. Such a value is superior to that of a general polyether thermoplastic elastomer. . In particular, when applied to the cover of the vehicle airbag device, it is possible to prevent the scattering of debris during the deployment of the airbag device cover even after long-term use and to maintain a stable deployment performance.

Features and other advantages of the present invention as described above will become more apparent from the examples and comparative examples described below. However, the present invention is not limited to the following examples. In the present invention, the optimum composition of the highly durable polyetherester thermoplastic elastomer having excellent deployment characteristics while maintaining flexibility, molding processability and scratch resistance, especially for a vehicle airbag cover device, has been established.

Examples 1-8 and Comparative Examples 1-6

The polyetherester thermoplastic elastomer resin composition was prepared as ingredients and contents as shown in Table 1 below.

Referring to Example 1, a specific manufacturing method will be described. As a main component, polyether ester resin, KOLON KP3355 50% by weight of polyetherester thermoplastic elastomer resin KOPEL KP3355 of Kolon Co., Ltd. having a Shore hardness of 55D and surface hardness of Shore 40D is KOPEL KP3340. 50 wt% was mixed for 1 hour in a tumbler type mixer. The obtained polyether ester resin was molecular weight distribution 2.0-2.5.

The hardness of the polyether ester block copolymer is the surface hardness, measured according to ASTM D-2240, and the unit is expressed as Shore D. The molecular weight distribution was determined by gel permeation chromatography, which is expressed as the weight average molecular weight divided by the number average molecular weight.

To 98.2% by weight of the bicomponent polyether ester thus obtained, 0.6% by weight of sodium 2,2'-methylene-bis- (4,6-di-tert-butylphenyl) phosphate as a durable additive, N, N'-hexane- 0.6 wt% of 1,6-diyl bis (3- (3,5-di-tert-butyl-4-hydrophenylphenyl propionamide) and 0.6 wt% of 2,2'-m-phenylene bis (2-oxazolcin) % Was melt-kneaded through a twin screw extruder to prepare a resin composition.

At this time, the temperature of the extruder was set to 180 ° C, 200 ° C, 210 ° C, 220 ° C, 230 ° C in order from the primary inlet to the die, and the rotation speed of the screw was mixed under conditions of 250 RPM.

The mixed resin was discharged onto a strand, and solidified in a cooling bath having a temperature of 35 ° C., and then obtained as a pelletized product through a pelletizer.

division Resin composition (% by weight)  Additive Composition (wt%) A B C D E (a) (b) (c) (d) Example One 49.1 49.1 0 0 0 0.6 0.6 0 0.6 2 49.1 49.1 0 0 0 0.6 0 0.6 0.6 3 49.1 49.1 0 0 0 0.6 0.3 0.3 0.6 4 49.4 49.4 0 0 0 0.6 0 0.3 0.3 5 49.4 49.4 0 0 0 0.6 0.3 0 0.3 6 49.3 49.3 0 0 0 0.2 0.6 0 0.6 7 68.7 29.5 0 0 0 0.6 0.6 0 0.6 8 29.5 68.7 0 0 0 0.6 0.6 0 0.6 Comparative example One 50 50 0 0 0 0 0 0 0 2 49.7 49.7 0 0 0 0.6 0 0 0 3 49.4 49.4 0 0 0 0 0.6 0 0.6 4 0 0 100 0 0 0 0 0 0 5 0 0 0 100 0 0 0 0 0 6 0 0 0 0 100 0 0 0 0 (Resin composition) A: Kolon KOPEL KP3340 (Shore Hardness 40D), B: Kolon KOPEL KP3355 (Shore Hardness 55D) C: Dupont DYM-100 (Shore Hardness 45D), D: Solvay Dexflex 756-67-1 (Shore Hardness 50D ) E: Tecnor Apex Tekron 4300D-82A (Shore Hardness 42D) (Additive Composition) (a): Sodium 2,2'-methylene-bis- (4,6-di-tert-butylphenyl) phosphate (b): N , N′-nucleic acid-1,6-diyl bis (3- (3,5-di-tert-butyl-4-hydroxyphenyl propionamide (c): 4,4′-bis (α, α-dimethylbenzyl Disphenylamine) (d): 2,2'-m-phenylene bis (2-oxazolcin)

The resin composition prepared in Examples 1 to 8 and Comparative Examples 1 to 6 was dried at 100 ° C. for 5 hours using a dehumidifying hot air dryer to remove moisture, and used for the measurement of physical properties and an airbag device for a vehicle using an injection molding machine. The cover was molded and evaluated in the following manner, and the results are shown in Table 2 below.

Specific measuring methods are as follows;

Tensile strength: measured according to ASTM D-638 and is in kg / cm 2.

Elongation: measured according to ASTM D-638 and is in% to be.

Endurance time: After the heat treatment at a temperature of 168 ° C. in a UL oven for a predetermined time, the tensile strength and elongation were evaluated for the initial physical properties. Evaluated.

Moldability: In molding the thermoplastic elastomer composition into a cover for an airbag apparatus using an injection molding machine, the moldability is visually confirmed by visually confirming the appearance of flow marks, glossiness, and the like and the release state at the time of injection molding of the manufactured cover molded article. Evaluated. In the case of excellent appearance and releasability, moldability was evaluated as O, and in the case of very poor appearance and releasability, X was evaluated, and a case judged to be in the middle region was evaluated as Δ.

Method for evaluating the development of airbag cover: The injection molded airbag cover is composed of a module together with an inflator and an airbag, and the manufactured module is fixed to a steel holding device, and then -40 ° C, 23 ° C, and 85 ° C, respectively. Inject into maintained thermostat Each module maintains in the cabinet for 1 hour after the temperature in the cabinet reaches a constant temperature, then removes the module from the cabinet, mounts a trestle, and ignites the ignition control in the inflator by flowing a current to deploy the airbag. . The evaluation of the deployment characteristics is that the deployment crack of the airbag cover deployed according to the above procedure is made at the tear seam, and the deployment characteristics are evaluated as excellent when the fracture pieces do not scatter during deployment, otherwise the deployment characteristics are poor. Evaluate.

division The tensile strength Tensile elongation Endurance Formability Development characteristics -30 ℃ 23 ℃ 85 ℃ Example 1 220.1 589.2 76 O Good Good Good Example 2 228.2 587.3 84 O Good Good Good Example 3 221.3 577.0 84 O Good Good Good Example 4 224.7 576.4 48 O Good Good Good Example 5 226.6 583.2 48 O Good Good Good Example 6 224.3 580.3 64 O Good Good Good Example 7 199.2 687.5 64 O Good Good Good Example 8 232.2 528.1 92 O Good Good Good Comparative Example 1 205.5 550.6 8 O Bad Good Bad Comparative Example 2 222.7 567.2 13 O Bad Good Good Comparative Example 3 218.8 546.6 16 O Bad Good Good Comparative Example 4 222.0 580.0 13 O Good Good Good Comparative Example 5 111.8 191.6 24 X Bad Good Bad Comparative Example 6 112.6 307.0 9 △ Bad Good Good

As described above in detail, according to the present invention, a polyether ester block copolymer composed of a combination of a high hardness polyether ester resin and a low hardness polyether ester resin is mainly composed of sodium 2,2'-methylene-bis- (4 Polyetherester thermoplastic elastomer resin compositions comprising, 6-di-tert-butylphenyl) phosphate as nucleating agent and further comprising stabilizers, while maintaining flexibility, formability and scratch resistance, are particularly useful for automotive airbag cover devices. It has excellent development characteristics.

Claims (7)

(Correction) In the thermoplastic polyether ester elastomer resin composition containing a polyether ester block copolymer as a main component, The polyether ester block copolymer is a combination of 10 to 90 wt% of a low hardness polyether ester block copolymer having a Shore hardness of 40 to 50 D and 90 to 10 wt% of a high hardness polyether ester block copolymer having a Shore hardness of 50 to 63 D. And an alkali metal salt nucleating agent and a stabilizer of phosphate having a bisphenyl ligand represented by the formula (3) as an additive, wherein the highly durable thermoplastic polyetherester elastomer resin composition. Formula 3 Wherein R ₁ and R ₂ are each C ₂ to C ₂₀ aliphatic, aromatic and cyclic hydrocarbon radicals, and M is an alkali metal such as Li, Na, K having a monovalent charge. (delete) The high durability thermoplastic polyetherester elastomer resin according to claim 1, wherein the nucleating agent is sodium 2,2'-methylene-bis- (4,6-di-tert-butylphenyl) phosphate represented by the following Chemical Formula 4. Composition. Formula 4 (Correction) The highly durable thermoplastic polyether ester elastomer resin composition according to claim 1 or 3, wherein the nucleating agent is contained so as to be 0.05 to 3.5 parts by weight based on 100 parts by weight of the polyether ester block copolymer. The stabilizer according to claim 1, wherein the stabilizers are 2,2'-m-phenylene bis (2-oxazolcin), 4,4'-bis (α, α-dimethylbenzyl disphenylamine) and N, N'-hexane- Highly durable thermoplastic polyether ester, characterized in that one or more selected from the group consisting of 1,6-diyl bis (3- (3,5-di-tert-butyl-4-hydroxyphenyl-propionamide) Elastomer Resin Composition. 6. The highly durable thermoplastic polyetherester elastomer resin composition according to claim 1 or 5, wherein the stabilizer is included in an amount of 0.1 to 1.0 parts by weight based on 100 parts by weight of the polyetherester block copolymer. A cover for a vehicle airbag device molded from the high durability thermoplastic polyetherester elastomer resin composition according to claim 1.