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(11) | EP 2 077 258 B1 |
| (12) | EUROPEAN PATENT SPECIFICATION |
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| (54) |
Gelatinous enhancer for inflator Gelatineartige Verbesserung für einen Gasgenerator Élément d'amélioration gélatineux pour gonfleur |
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| Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention). |
BACKGROUND OF INVENTION
Field of Invention
[0001] The present invention relates to a gelatinous enhancer for an inflator, which is used in an inflator for an air bag apparatus or other applications.
Description of Arts
[0002] B/KNO3 is widely employed as a enhancer for an inflator. B/KNO3 has a high combustion temperature and favorable ignitability in relation to a gas generant. However, B/KNO3 burns vigorously, and therefore burns out instantaneously. Hence, B/KNO3 is insufficient as a enhancer for a gas generant having low ignitability. Furthermore, B/KNO3 is expensive and exhibits a low gas efficiency.
[0003] Further, when B/KNO3 is used, a problem arises in that an abnormal noise occurs during an operation. This problem can be solved by employing a elastic enhancer, but an elastic enhancer is easily affected by the environmental temperature and is therefore unsatisfactory in terms of operational reliability over a wide temperature range (-40°C to 105°C) .
US-A No .2005/0235863, JP-A No. 2000-86376 and JP-A No. 2002-12493 are in the state of arts.
WO2005/072401 discloses an inflator comprising an enhancer.
SUMMARY OF INVENITON
[0004] An invention relates to a gelatinous enhancer for an inflator, including silicone oil and ammonium nitrate.
DETAILED DESCRIPTION OF INVENTION
[0005] The present invention provides a gelatinous enhancer for an inflator, which can solve problems relating to costs, ignitability in relation to a gas generant, and so on.
[0006] The invention preferably relates to a gelatinous enhancer for an inflator, wherein the silicone oil content ranges from 5 to 35 mass% and the ammonium nitrate content ranges from 65 to 95 mass%.
[0007] The gelatinous enhancer for an inflator according to the present invention generates more combustion heat than B/KNO3, which is widely used as a enhancer, and therefore exhibits favorable ignitability in relation to a gas generant having low ignitability. Further, the gas efficiency of the gelatinous enhancer for an inflator according to the present invention is high, and therefore gas generated thereby can be used also to inflate an air bag. Thus, gas generated from the gas generant can be complemented by the gas generated by the gelatinous enhancer.
Preferred Embodiment of Invention
[0008] Known silicone oil is used in the present invention (see [0016] to [0019] of US-A No .2005/0235863, for example), and either straight silicone oil or denatured silicone oil may be used. However, straight silicone oil (polydimethylsiloxane, for example) is preferable.
[0009] To provide the enhancer in a gelatinous form, the viscosity of the silicone oil is preferably within a range of 100 to 20,000cm2/s, more preferably within a range of 500 to 15,000cm2/s, and even more preferably within a range of 1000 to 15,000cm2/s. The method of measuring the viscosity corresponds to the method described in JIS K2283, and a value measured at 25°C is taken.
[0010] The silicone oil content is preferably between 3 and 30 mass%, more preferably according to the invention between 5 and 25 mass%, and even more preferably according to the invention between 5 and 20 mass%.
[0011] Ammonium nitrate used in the present invention may be a normal ammonium nitrate or an ammonium nitrate subjected to phase stabilization by a known method (for example, JP-A No. 2002-338241, JP-A No. 2006-520312, JP-A No. 10-259085) using potassium nitrate, an inorganic potassium salt such as potassium perchlorate, an organic potassium salt such as potassium oxalate, or the like.
[0012] The ammonium nitrate content is preferably between 70 and 97 mass%, more preferably according to the invention between 75 and 95 mass%, and even more preferably according to the invention between 80 and 95 mass%.
[0013] The gelatinous enhancer for an inflator according to the present invention may be a three component-based enhancer including a nitrogen-containing compound in addition to the silicone oil and ammonium nitrate described above. When a nitrogen-containing compound is included, the gas efficiency (mol/100g; expressing the number of moles of gas generated per 100g of gas generant) increases and an initial pressure upon ignition increases, preferably leading to an improvement in ignitability in relation to the gas generant.
[0014] When a nitrogen-containing compound is included, the nitrogen-containing compound content is 30 mass% or less of the total amount of the ammonium nitrate and the nitrogen-containing compound.
[0015] The nitrogen-containing compound is selected from a tetrazole derivative, guanidine, guanidine carbonate, nitroguanidine, dicyandiamide, nitroaminoguanidine, and nitroaminoguanidine nitrate.
[0016] Examples of tetrazole derivatives include tetrazole, 5-aminotetrazole, 5,5'-bi-1H-tetrazole, 5-nitroaminotetrazole, 5-aminotetrazole zinc salt, 5-aminotetrazole copper salt, bitetrazole, bitetrazole potassium salt, bitetrazole sodium salt, bitetrazole magnesium salt, bitetrazole calcium salt, bitetrazole diammonium salt, bitetrazole copper salt, and bitetrazole melamine salt.
[0017] The gelatinous enhancer for an inflator according to the present invention can be obtained by blending a predetermined amount of silicone oil, a predetermined amount of ammonium nitrate, and in certain cases, a predetermined amount of a nitrogen-containing compound.
[0018] The gelatinous enhancer for an inflator according to the present invention can be applied to various types of inflators having a known gas generant, for example an inflator for an air bag used in a driver side, an inflator for an air bag for a front passenger side, an inflator for a side air bag, an inflator for an inflatable curtain, an inflator for a knee bolster, an inflator for an inflatable seatbelt, an inflator for a tubular system, and an inflator for a pretensioner of various types of vehicles.
Examples
Examples and Comparative Example
[0019] By blending the components shown in Table 1, a gelatinous enhancer for an inflator according to Examples and a enhancer according to Comparative Example were obtained. The following tests were performed on these enhancers. The results are shown in Table 1.
(1) Combustion temperature (K)
(2) Combustion heat (cal/g, whereby 1 calorie is 4,184 Joules)
(3) Gas efficiency (mol/100g)
(4) Friction sensitivity (N), drop hammer sensitivity (cm)
[0023] The friction sensitivity (N) and the drop hammer sensitivity (cm) were measured on the basis of an explosive performance test method described in JIS K4810-1979.
Table 1
| Gas generant composition (mass%) | Combustion temperature (K) | Combustion heat(cal/g) | Gas efficiency (mol/100g) | Friction sensitivity (N) | Drop hammer sensitivity (cm) | |
| Example 1 | Silicone oil(1)/Ammonium nitrate = 10.4/89.6 | 2393 | 1191 | 4.06 | >353 | 50-60 |
| Example 2 | Silicone oil(2)/Ammonium nitrate = 10.4/89.6 | 2393 | 1191 | 4.06 | >353 | 50-60 |
| Example 3 | Silicone oil(3)/Ammonium nitrate = 10.4/89.6 | 2393 | 1191 | 4.06 | >353 | 50-60 |
| Comparative Example 1 | B/KNO3=25/75 | 3089 | 827 | 1.34 | >353 | 30-40 |
Ammonium nitrate: product name K-320 (manufactured by Sumitomo Chemical Co., Ltd.)
Silicone oil (1): product name TSF451-30M (manufactured by Momentive Performance Materials Japan LLC.), viscosity 3000cm2/s
Silicone oil (2): product name KF-96 (manufactured by Shin-Etsu Chemicals Co., Ltd.), viscosity 5,000cm2/s
Silicone oil (3): product name KF-96H (manufactured by Shin-Etsu Chemicals Co., Ltd.), viscosity 10,000cm2/s
1. A gelatinous enhancer for an inflator, comprising silicone oil, ammonium nitrate,
and a nitrogen-containing compound selected from the group consisting of a tetrazole
derivative, guanidine, guanidine carbonate, dicyandiamide, nitroaminoguanidine and
nitroamino guanidine nitrate,
wherein the silicone oil content ranges from 5 to 25 mass%, the ammonium nitrate content ranges from 75 to 95 mass%, and the nitrogen-containing compound content is 30 mass% or less of the total of the ammonium nitrate and the nitrogen-containing compound.
wherein the silicone oil content ranges from 5 to 25 mass%, the ammonium nitrate content ranges from 75 to 95 mass%, and the nitrogen-containing compound content is 30 mass% or less of the total of the ammonium nitrate and the nitrogen-containing compound.
2. A gelatinous enhancer for an inflator, consisting of silicone oil, ammonium nitrate,
and optionally a nitrogen-containing compound,
wherein the silicone oil content ranges from 5 to 35 mass% and the ammonium nitrate content ranges from 65 to 95 mass%,
wherein the nitrogen-containing compound is selected from the group consisting of a tetrazole derivative, guanidine, guanidine carbonate, nitroguanidine, dicyanamide, nitroaminoguanidine, and nitroaminoguanidine nitrate, and
wherein the viscosity of the silicone oil is in the range of 100 to 20,000 cm2/s.
wherein the silicone oil content ranges from 5 to 35 mass% and the ammonium nitrate content ranges from 65 to 95 mass%,
wherein the nitrogen-containing compound is selected from the group consisting of a tetrazole derivative, guanidine, guanidine carbonate, nitroguanidine, dicyanamide, nitroaminoguanidine, and nitroaminoguanidine nitrate, and
wherein the viscosity of the silicone oil is in the range of 100 to 20,000 cm2/s.
1. Gelatineartiger Verstärker für einen Gasgenerator, umfassend Siliconöl, Ammoniumnitrat
und eine stickstoffhaltige Verbindung ausgewählt aus der Gruppe bestehend aus einem
Tetrazolderivat, Guanidin, Guanidincarbonat, Dicyandiamid, Nitroaminoguanidin und
Nitroaminoguanidinnitrat,
wobei der Siliconölgehalt im Bereich von 5 bis 25 Massenprozent liegt, der Ammoniumnitratgehalt im Bereich von 75 bis 95 Massenprozent liegt, und der Gehalt der stickstoffhaltigen Verbindung 30 Massenprozent oder weniger der Summe des Ammoniumnitrats und der stickstoffhaltigen Verbindung beträgt.
wobei der Siliconölgehalt im Bereich von 5 bis 25 Massenprozent liegt, der Ammoniumnitratgehalt im Bereich von 75 bis 95 Massenprozent liegt, und der Gehalt der stickstoffhaltigen Verbindung 30 Massenprozent oder weniger der Summe des Ammoniumnitrats und der stickstoffhaltigen Verbindung beträgt.
2. Gelatineartiger Verstärker für einen Gasgenerator, bestehend aus Siliconöl, Ammoniumnitrat
und gegebenenfalls einer stickstoffhaltigen Verbindung,
wobei der Siliconölgehalt im Bereich von 5 bis 35 Massenprozent liegt und der Ammoniumnitratgehalt im Bereich von 65 bis 95 Massenprozent liegt,
wobei die stickstoffhaltige Verbindung ausgewählt ist aus der Gruppe bestehend aus einem Tetrazolderivat, Guanidin, Guanidincarbonat, Nitroguanidin, Dicyanamid, Nitroaminoguanidin und Nitroaminoguanidinnitrat, und
wobei die Viskosität des Siliconöls im Bereich von 100 bis 20000 cm2/s liegt.
wobei der Siliconölgehalt im Bereich von 5 bis 35 Massenprozent liegt und der Ammoniumnitratgehalt im Bereich von 65 bis 95 Massenprozent liegt,
wobei die stickstoffhaltige Verbindung ausgewählt ist aus der Gruppe bestehend aus einem Tetrazolderivat, Guanidin, Guanidincarbonat, Nitroguanidin, Dicyanamid, Nitroaminoguanidin und Nitroaminoguanidinnitrat, und
wobei die Viskosität des Siliconöls im Bereich von 100 bis 20000 cm2/s liegt.
1. Élément d'amélioration gélatineux pour gonfleur, comprenant de l'huile de silicone,
du nitrate d'ammonium et un composé azoté choisi dans le groupe constitué d'un dérivé
tétrazole, de guanidine, de carbonate de guanidine, de dicyandiamide, de nitroaminoguanidine
et de nitrate de nitroaminoguanidine,
où la teneur en huile de silicone va de 5 à 25 % en masse, la teneur en nitrate d'ammonium va de 75 à 95 % en masse et la teneur en composé azoté est de 30 % en masse ou moins du total du nitrate d'ammonium et du composé azoté.
où la teneur en huile de silicone va de 5 à 25 % en masse, la teneur en nitrate d'ammonium va de 75 à 95 % en masse et la teneur en composé azoté est de 30 % en masse ou moins du total du nitrate d'ammonium et du composé azoté.
2. Élément d'amélioration gélatineux pour gonfleur, constitué d'huile de silicone, de
nitrate d'ammonium et éventuellement d'un composé azoté,
où la teneur en huile de silicone va de 5 à 35 % en masse et la teneur en nitrate d'ammonium va de 65 à 95 % en masse,
où le composé azoté est choisi dans le groupe constitué d'un dérivé tétrazole, de guanidine, de carbonate de guanidine, de nitroguanidine, de dicyanamide, de nitroaminoguanidine et de nitrate de nitroaminoguanidine, et
où la viscosité de l'huile de silicone est dans la plage de 100 à 20 000 cm2/s.
où la teneur en huile de silicone va de 5 à 35 % en masse et la teneur en nitrate d'ammonium va de 65 à 95 % en masse,
où le composé azoté est choisi dans le groupe constitué d'un dérivé tétrazole, de guanidine, de carbonate de guanidine, de nitroguanidine, de dicyanamide, de nitroaminoguanidine et de nitrate de nitroaminoguanidine, et
où la viscosité de l'huile de silicone est dans la plage de 100 à 20 000 cm2/s.
REFERENCES CITED IN THE DESCRIPTION
This list of references cited by the applicant is for the reader's convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.
Patent documents cited in the description
- US20050235863A [0003] [0008]
- JP2000086376A [0003]
- JP2002012493A [0003]
- WO2005072401A [0003]
- JP2002338241A [0011]
- JP2006520312A [0011]
- JP10259085A [0011]