阅读说明：本技术 非硝酸铵基推进剂 (Non-ammonium nitrate based propellants ) 是由 詹姆斯·M·罗斯 蒂莫西·韦恩·弗雷泽 丹·R·德诺姆 于 2019-01-17 设计创作，主要内容包括：本公开涉及针对混合式气囊气体发生器优化的气囊产气剂配方,以及气囊气体发生器,气囊,包括该气囊的气囊模块,以及使用该气囊产气剂对气囊进行充气的方法。(The present disclosure relates to an airbag gas generant formulation optimized for a hybrid airbag inflator, and an airbag inflator, an airbag module including the airbag, and a method of inflating an airbag using the airbag gas generant.)

1. An airbag gas generant formulation optimized for a hybrid airbag inflator, the formulation comprising:

40 to 50 wt% strontium nitrate;

35 to 45 wt% nitroguanidine;

3 to 7 wt% potassium perchlorate;

3 to 6 wt% polyvinyl alcohol; and

2 to 6 wt% of strontium oxalate.

2. An airbag gas generant formulation in accordance with claim 1 having at least one property selected from the group consisting of:

a gas yield greater than 1.57 grams per cubic centimeter (g/cc);

the constant volume flame temperature is 2700-2800K; and

the total oxygen balance of the formulation is-2% to + 2%.

3. An airbag gas generant formulation in accordance with claim 1 wherein said formulation comprises:

48.2 wt% strontium nitrate;

36.8 wt% nitroguanidine;

5 wt% potassium perchlorate;

5 wt% strontium oxalate; and

5% by weight of polyvinyl alcohol.

4. An airbag gas generant formulation in accordance with claim 1 wherein said formulation further comprises:

1 to 5 wt% of copper oxide as a burn rate modifier.

5. An airbag gas generant formulation according to claim 4 wherein the formulation is:

44.1 wt% strontium nitrate;

39.9 wt% nitroguanidine;

5 wt% potassium perchlorate;

4 wt% strontium oxalate;

4 wt% polyvinyl alcohol; and

3 wt% copper oxide.

6. An airbag gas generant formulation in accordance with claim 1 further comprising:

2 to 6 wt% kaolin is used for slagging and as a coolant.

7. An airbag gas generant formulation in accordance with claim 1 further comprising:

2 to 6 wt% alumina is used for slagging and as coolant.

8. An airbag gas generant formulation in accordance with claim 1 further comprising:

2 to 6 wt% silica is used for slagging and as coolant.

9. An airbag gas generant formulation in accordance with claim 1 further comprising:

2wt to 6 wt% of at least one selected from: kaolin, alumina and silica.

10. An airbag gas generant formulation in accordance with claim 1 which does not contain oxygen as a storage gas.

11. A gas generator for an airbag comprising the airbag gas generant formulation of claim 1, wherein the gas generator does not comprise oxygen as a storage gas.

12. A method of inflating an airbag comprising the steps of: igniting the airbag gas generant formulation of claim 1 to produce a gas; and inflating the balloon with the gas.

13. The method of claim 12, wherein the igniting step does not include igniting oxygen, which may be a stored gas.

Background

With the use of ammonium nitrate based propellants in automotive airbag gas generators, whether they be used in pyrotechnic gas generators or hybrid gas generators, has become unacceptable, there is a great need for a propellant that is a replacement or does not contain ammonium nitrate. Even though in hybrid gas generators the propellant is stored in a high pressure inert gas atmosphere, making it difficult for moisture to soak in, ammonium nitrate based propellants are still considered unacceptable.

Brief summary

One aspect of the present disclosure relates to a gas generant formulation. The gas generant may be used as a gas generant formulation for an airbag. A number of gas generant formulations are disclosed herein, it being understood that "formulation" or "the formulation" may refer to any one or more of the gas generant formulations or airbag gas generant formulations herein, unless otherwise indicated. That is any non-ammonium nitrate based propellant of the present disclosure.

The airbag gas generant formulation (e.g., as claimed) may be optimized for an airbag inflator, particularly a hybrid airbag inflator. One aspect is an airbag gas generant formulation comprising the following ingredients: 40 to 50 wt% strontium nitrate, 35 to 45 wt% nitroguanidine, 3 to 7 wt% potassium perchlorate, 3 to 6 wt% polyvinyl alcohol and 2 to 6 wt% strontium oxalate. In this case, the components can be adjusted to 100 wt% without any other components. Alternatively, in any aspect of the present disclosure, when the sum of the ingredients does not reach 100 wt%, the ingredients may be adjusted to 100 wt% using a filler.

Unless otherwise indicated, wt% refers to "weight percent," which is the weight of one chemical relative to the weight of the total airbag gas generant formulation. When the wt% is less than 100%, any filler known to one of ordinary skill in the art may be added. For example, the filler may be an inert filler such as clay, chalk, etc. Inert fillers refer to chemicals or ingredients that do not react with other ingredients in the formulation in the environment in which the formulation is typically found. Such an environment may be, for example, in an airbag inflator, in a warehouse, or in an automobile. Each of these locations may be subject to conditions to which the airbag inflator, automobile or warehouse is expected to be subjected, including for example, extremely cold to very hot conditions to which the automobile is subjected in sunlight and in a desert.

The gas generant formulations and airbag gas generant formulations of the present disclosure have a number of desirable properties. One aspect relates to a formulation having at least one property selected from the group consisting of: a gas yield greater than 1.57 grams per cubic centimeter (g/cc); and the constant volume flame temperature is 2700-2800K; the total oxygen balance of the formulation is-2% to + 2%. In a preferred aspect, the formulation comprises two of these properties. In another preferred aspect, the formulation comprises all of these properties.

One aspect relates to an airbag gas generant formulation comprising: 48.2 wt% of strontium nitrate, 36.8 wt% of nitroguanidine, 5 wt% of potassium perchlorate, 5 wt% of strontium oxalate and 5 wt% of polyvinyl alcohol.

Another aspect relates to any one of the formulations of the present disclosure, wherein the formulation further comprises 1 wt% to 5 wt% of copper oxide as a burn rate modifier. For example, an airbag gas generant formulation may include: 44.1% by weight of strontium nitrate, 39.9% by weight of nitroguanidine, 5% by weight of potassium perchlorate, 4% by weight of strontium oxalate, 4% by weight of polyvinyl alcohol and 3% by weight of copper oxide.

In another aspect, the airbag gas generant formulation may further comprise 2 to 6 wt% kaolin clay. Kaolin can be used for slagging and as a coolant. In another aspect, the airbag gas generant formulation may further comprise 2 to 6 weight percent alumina. The alumina can be used for slagging and as a coolant. In another aspect, the airbag gas generant formulation may further comprise 2 to 6 weight percent silica. The silica can be used for slagging and as a coolant. In another aspect, the airbag gas generant formulation may further comprise 2 to 6 wt% of at least one component, which may be one, two or all three of the following: kaolin, alumina and silica.

Vehicles may include various airbags that may deploy during a vehicle collision to absorb energy from a vehicle occupant during the collision. The airbag may be a component of an airbag assembly that includes an airbag inflator in communication with the airbag for inflating the airbag from an uninflated position to an inflated position.

One aspect relates to an airbag inflator that includes an airbag gas generant formulation described in the present disclosure.

Another aspect relates to an airbag module or airbag that includes an airbag gas generant formulation described in the present disclosure.

Another aspect relates to a method of inflating an airbag. The method comprises the following steps: igniting an airbag gas generant of any of the airbag gas generant formulations described in this disclosure to produce a gas; and inflating the balloon with the gas.

Detailed Description

The present disclosure describes non-ammonium nitrate based propellants that are optimized as alternatives to and improvements over ammonium nitrate based hybrid gas generator propellants.

The hybrid gas generator includes a stored gas and a pyrotechnic material. In some hybrid gas generator designs, the reservoir that stores the gas contains both the high pressure gas and the pyrotechnic material. In hybrid gas generators, pyrotechnic materials are used to generate gas and heat stored gas. Ammonium nitrate based propellants are effective because of their high gas yield and relatively high combustion temperature, as compared to those required for pyrotechnic gas generators. The formulation of the ammonium nitrate based propellant blends is near stoichiometric and therefore does not produce unacceptable levels of carbon monoxide or nitrogen oxides and their oxygen balance is near zero. In this type of hybrid gas generator, the stored gas is inert. Some hybrid gasifier designs use a highly negative oxygen balance formula that produces carbon monoxide (CO) and hydrogen (H)₂) Oxygen needs to be added to the stored gas to combust CO and H separately₂Is CO₂And H₂And O. Such formulations are described in us patent 7,942,990. The formulations described herein do not require the inclusion of oxygen in the stored gas.

Ammonium nitrate based propellants have a high gas yield relative to the volume of the solid propellant. For example, the ammonium nitrate based propellants described in U.S. Pat. Nos. 5,850,053 and 6,136,113 have a theoretical density of 1.66g/cc and a gas yield of 1.57g gas per cubic centimeter (cc) of solid propellant. The constant pressure flame temperature for these formulations was 2240K, and the constant volume flame temperature was 2700K. For alternative propellants to be operated in the same hybrid gas generator, it is preferred to have the same or equal gas production rate per solid volume and flame temperature.

Due to the foregoing limitations of having a high volumetric gas production rate per solid gas generant and the absence of ammonium nitrate in the propellant, metal-containing oxidizers and high density fuels are very attractive. This type of propellant has a low gas production rate per unit weight, but due to its high solid density, produces the same amount of gas per solid volume as ammonium nitrate based propellants. It is also desirable to use common or least costly ingredients for gas generants. For pyrotechnic gas generators, the fuel of choice today is Guanidine Nitrate (GN). Example 1 shows GN with different oxidizers, as shown in this example, no 1.57g gas per cubic centimeter of solid propellant can be generated when GN is used as a fuel.

The following chemical components recited in the claims are well known to those of ordinary skill in the art. They comprise at least strontium nitrate (Sr (NO)₃)₂) (ii) a Potassium perchlorate (KClO)₄) (ii) a Polyvinyl alcohol; strontium oxalate (SrC)₂O₄) (ii) a Copper oxide (CuO); kaolin; alumina (Al)₂O₃) (ii) a And silicon dioxide (SiO)₂). Nitroguanidine ((NH)₂)₂CNNO₂Or NO₂NHC(＝NH)NH₂) Is commercially available and is also well known, it exists in two tautomeric forms, namely nitroimine (left) or nitrosamine (right).

In solution and solid state, the nitroimine form predominates (resonance stabilization).

Reference merging

All publications, patent applications, and patents mentioned anywhere in this disclosure are herein incorporated by reference in their entirety to the same extent as if each individual publication or patent application was specifically and individually indicated to be incorporated by reference. In case of conflict, the present application, including all definitions herein, will control.

Examples