WO2003011798A1

WO2003011798A1 - Binder for gas-generating agent and gas-generating agent composition containing the same

Info

Publication number: WO2003011798A1
Application number: PCT/JP2002/007775
Authority: WO
Inventors: Tameo Kawakami; Ryoi Kodama
Original assignee: Nippon Kayaku Kabushiki-Kaisha
Priority date: 2001-08-01
Filing date: 2002-07-31
Publication date: 2003-02-13

Abstract

A binder for gas-generating agents which comprises at least one cationic polymer selected from the group consisting of cationic polyacrylamide, cationic polyvinyl alcohol, and cationic methyl cellulose and at least one anionic polymer selected from the group consisting of sodium polyacrylate, anionic polyacrylamide, anionic polyvinyl alcohol, and anionic methyl cellulose. The binder has high binding power and excellent thermal stability.

Description

Description Binder for gas generating agent, and gas generating composition using the same

The present invention relates to a binder for a gas generating agent, a gas generating composition and a gas generating method using the same, and is particularly suitable for a small and lightweight gas generator. Background art

As gas generating agents for airbags as occupant protection devices in automobiles, gas generating agents containing various nitrogen-containing organic compounds, which are safer non-azide fuels, have been developed in place of sodium azide.

For example, U.S. Pat. No. 5,545,272 discloses a gas generant composition of ammonium nitrate and nitroguanidine phase stabilized with 7-20% by weight of a potassium salt; Japanese Patent Application Laid-Open No. 7_33047 discloses a gas generating agent comprising a composition of nitroguanidine, phase-stabilized ammonium nitrate and a rubbery binder. Acrylate-terminated polybutadiene, polypudadienepolycarbonic acid, epoxy-modified polybutadiene, a curing agent and an oxidizing agent, and a gas generating composition disclosed in JP-A-6-927770. Wherein the binder comprises the reaction product of a hydroxyl-containing polyglycidyl azide and at least one polyisocyanate, particularly comprising an organic binder, an active plasticizer and an oxidizing filler. At least 8 fivefold Japanese Patent Application Laid-Open No. H10-72273 discloses a gas generant composition in which the amount of ammonium nitrate is% by weight; ammonium nitrate and metal salts of tetrazole, aminotetrazole, bitetrazole, bitetrazole, A gas generating agent comprising one or more reducing agents such as bitetrazole ammonium salt, nitroguanidine, guanidine nitrate and dicyandiamide and a combustion regulator such as copper oxide and manganese dioxide is disclosed.

However, in these gas generating agents, for example, when a phase-stabilized ammonium nitrate is used as a compounding agent, the heat stability of the gas generating agent is unstable, and In order to prevent them from expanding or cracking under the influence, a binder system with strong bonding power and excellent thermal stability was required.

The present inventors have conducted intensive studies on the components of the gas generating composition, that is, the combination of the fuel component, the oxidizing agent component, and the additive, in order to solve the above-mentioned problems. The inventors have found that the above problems can be solved by using a mixture with a molecular compound as a binder, and have completed the present invention. Disclosure of the invention

That is, the present invention

(1) A binder for a gas generator comprising a mixture of a cationic polymer compound and an anionic polymer compound.

(2) Cationic polymer compound of at least one selected from the group consisting of cationic polyacrylamide, cationic polypinyl alcohol and cationic methylcellulose, sodium polyacrylate, anionic polyacrylamide, anionic A binder for a gas generating agent, comprising: an anionic polymer compound comprising at least one selected from the group consisting of polyvier alcohol and anionic methyl cellulose.

(3) A gas generant composition using the gas generant binder according to (1) or (2).

(4) A gas generating composition containing the binder for a gas generating agent according to (1) or (2) in an amount of 0.5 to 10.0% by weight.

(5) A method of inflating an airbag using generated gas obtained by burning the gas generating composition according to (3) or (4).

, Concerning. BEST MODE FOR CARRYING OUT THE INVENTION

The binder for a gas generating agent of the present invention contains a cationic polymer compound and an anionic high-molecular compound.

The cationic polymer compound used in the present invention is used in a gas generating composition. It is a component having an indigenous action, and may also exhibit an action as a fuel. The cationic polymer compound is not particularly limited as long as it is ionized in the presence of water or the like and shows cationicity, and the colloid equivalent value (cationicity) shows a positive value. Examples include high molecular compounds having a group, but solid compounds are preferable within the operating temperature range of the gas generating agent (140T to 120 ° C). Oxygen balance, flammability, thermal stability, etc. of the high molecular compound From the viewpoint, it is preferable to use at least one selected from cationic polyacrylamide, cationic polyvinyl alcohol and cationic methyl cellulose.

Specific examples of such a cationic polymer compound are shown below.

(1) Cationic polyacrylamide

(CH ₂ CHCONH ₂ ) m (CH ₂ CHC OO C ₂ H ₄ N (CH ₃ ) ₃ CL) _n

(2) Cationic polyvinyl alcohol

(CH ₂ CHOH) _m (CH ₂ CHO CO CH ₃ ) _n

(3) Cationic methyl cellulose

(The chemical structural formula of cationized cellulose is shown as an example of cationic methyl cellulose.)

OH CH ₃

0-(CH CH2O) 2-CH CHCH N + -C12H25 Cellulose—〇One Cellulose CH3

[In the above general formula, m and n indicate the degree of polymerization, and m + n = l]

As the cationic polymer compound, among the above (1) to (3), cationic polyacrylamide having a colloid equivalent value (degree of cation) of (1) of 0 to 105.0 meq Z grams is particularly preferable. .

The anionic polymer compound used in the present invention is a component having a binder function in the gas generating composition, and may be a compound having a function as a fuel. The anionic polymer-conjugated product is not particularly limited as long as it is ionized in the presence of water or the like, exhibits anionic properties, and has a negative colloid equivalent value (degree of anion). Examples include a polymer compound having a carboxylic acid residue 残基 a sulfonic acid residue, but a solid compound is preferable in the operating temperature range of the gas generating agent (140 ° C. (: up to 120 ° C.). It is preferable to use at least one selected from sodium polyacrylate, anionic polyacrylamide, anionic polyvinyl alcohol, and anionic methylcellulose from the viewpoints of oxygen balance, flammability, thermal stability and the like.

Specific examples of such an anionic polymer compound are shown below.

(1) Metal polyacrylate

(CH ₂ CHCOOM) _m

(2) Anionic polyacrylamide

(CH 2CHCONH2) _m (CH2CHCOOM) _n

(3) Anionic polyvinyl alcohol

(CH 2CHOH) _m (CH ₂ CHOCOCH ₃ ) _n

(4) Anionic methylcell

(The chemical structural formula of carboxymethylcellulose sodium is shown as an example of anionic methylcellulose.)

CH2OCH2CO2 "Na +

-Cellulose— O— Cellulose- 0-

I

CH2OCH2CO2-Na +

[In the above general formula, M represents a cation such as ammonium, sodium, or potassium, m and n represent the degree of polymerization, and m + n = 1.]

As the anionic polymer compound, among the above (1) to (4), the colloid equivalent value (degree of anion) of (2) is 0 to 15.0 milliequivalents. Acrylamide is particularly preferred.

The binder of the present invention is a mixture of the above-mentioned cationic polymer compound and an anionic polymer compound. At this time, a neutralization reaction of charges between the cationic / anionic polymers is performed. As a result, a large polymer of the ion complex is formed, and as a result, a strong binding force is exhibited. For this reason, the binder of the present invention has a higher elasticity than a binder using only a cationic polymer compound or an anionic polymer compound or a binder using a nonionic polymer compound. Yes, it does not get stuck on the wall of the squeezer, making it easy to process the gas generating agent, and it can obtain extremely good thermal stability.

As described above, the binder for a gas generating agent of the present invention mixes the cationic polymer conjugate and the anionic polymer compound to neutralize the charge. Ideally, the charge equivalent of the compound and the charge equivalent of the anionic polymer compound are mixed to be equal, but either one may be present in excess.

The elasticity and sticking property of the binder of the present invention to a vessel wall and the like depend on the colloid equivalent value of a mixed system in which a cationic polymer compound and an anionic polymer compound are mixed, and are ± 1.5 milliequivalent. Z gram or less is preferable, and a value of zero to near zero is particularly preferable, so that the whole gas generating agent can be more strongly bonded and extremely good thermal stability can be obtained.

In order to obtain such a binder, for example, a cationic polymer compound and an anionic polymer compound are mixed in a weight ratio of 0.05: 1 to 1: 0.05. A specific example is a binder obtained by mixing 0.05 to 1 part by weight of cationic polyacrylamide and 0.05 to 1 part by weight of anionic polyacrylamide.

Subsequently, the gas generating composition of the present invention will be described.

The gas generating composition of the present invention contains the binder described above. The amount of the binder used is not particularly limited, but is preferably 0.5 to 10% by weight in the gas generating composition. In addition, the gas generating composition of the present invention can contain a plurality of binders. As the gas generating agent of the present invention, a fuel component, an oxidizing agent, a slag forming agent, and a combustion controlling agent which are usually used can be used in addition to the binder described above. Etc. can be used.

As the fuel component that can be used in the present invention, a nitrogen-containing organic compound is preferable, and guanidine derivatives, tetrazole derivatives, bitetrazol derivatives, triazole derivatives, hydrazine derivatives, triazine derivatives, azodicarbonamide derivatives, disocyanamide derivatives, and nitrogen-containing compounds are preferable. One type or a mixture of two or more types selected from the group consisting of transition metal complexes is exemplified. Specific examples of these include nitroguanidine, guanidine nitrate, 5-aminotetrazole, bitetrazole diammonium salt, 5-oxo-11,2,41-triazole, cyanoguanidine, triaminoguanidine nitrate, trihydrazinotriazine, and pyruret. Azodicarbonamide, piurea, lipohydrazide, lipohydrazide transition metal complex nitrate, oxalic acid dihydrazide, hydrazine metal complex nitrate, sodium dicyanamide, bis (dicyandiamide) copper (I) nitrate, 5-aminotetrazole Copper complexes and the like can be mentioned.

Various oxidizing agents can be used as the oxidizing agent that can be used in the gas generating composition according to the present invention, and include nitrates, nitrites, and cations selected from ammonium, alkali metals, alkaline earth metals, and transition metals. At least one or two or more oxidizing agents selected from the group consisting of perchlorates, chlorates, hydroxides and oxides are preferred. Specific examples thereof include ammonium nitrate (ammonium nitrate), sodium nitrate, potassium nitrate, Examples include magnesium nitrate, strontium nitrate, basic copper nitrate, and ammonium perchlorate. In addition, transition metal complexes such as diammine copper (II) nitrate and hexammine cobalt (III) can also be used. As for ammonium nitrate, phase-stabilized ammonium nitrate (PSAN), which is stabilized by adding 5 to 20% by weight of nitrite, is preferable.

Also, PSAN stabilized with transition metal amine nitrate, especially diammine copper (II) nitrate, diammine zinc (II) nitrate, diammine nickel (II) nitrate, and PSAN stabilized with other substances can be used. .

The function of the slag forming agent that can be used in the gas generating composition according to the present invention is, particularly, an alkali metal or an alkali metal generated by decomposition of an oxidizing component in the gas generating composition. This is a function to change from a liquid state to a solid state and stop it in the combustion chamber in order to avoid the release of alkaline earth metal oxides as mist outside the inflation environment.Slag formation optimized by differences in metal components You can choose the agent.

Specific examples of the slag forming agent include naturally occurring clay mainly composed of aluminogate such as acid clay, silica, bentonite, and force-oligin; synthetic artificial force such as synthetic force, synthetic force orinite, and synthetic smectite. Slag forming agents selected from at least one of the following: clay, a hydrated magnesium silicate mineral such as talc; alumina, aluminum hydroxide, and silicon nitride. Among these, acid clay, Alumina, silicon nitride or silica is preferred.

In addition, the combustion control agent that can be used in the present invention may be any as long as it can control the combustion of the gas generating agent. Specifically, iron oxide, nickel oxide, copper oxide, zinc oxide, manganese oxide, chromium oxide And transition metal oxides such as cobalt oxide, molybdenum oxide, vanadium oxide, and tungsten oxide; and carbons such as activated carbon, graphite, and black carbon.

As the binder other than the binder of the present invention that can be used in the gas generating composition of the present invention, any binder can be used as long as it does not significantly affect the combustion behavior of the composition. Specific examples of such a binder include hydroxyethyl cellulose, hydroxypropyl methylcellulose, methyl cellulose, cellulose acetate, cellulose propionate, cellulose acetate butyrate, nitrocellulose, microcrystalline cellulose, polyvinyl alcohol, guar gum, and starch. And organic binders such as polyacrylamide and polyvinylpyrrolidone, and inorganic binders such as molybdenum disulfide, acid clay, talc, bentonite, diatomaceous earth, kaolin, silica, alumina, and synthetic hydrotalcite. Then, the gas generating composition of the present invention can obtain the desired gas generating performance by using the binder, the fuel component, the oxidizing agent, the slag forming agent, the combustion regulator, the binder other than the binder of the present invention, and the like. What is necessary is just to mix it.

When the gas generating composition of the present invention contains a binder, a nitrogen-containing organic compound, and an oxidizing agent as its components, the range of each composition (weight ratio) is as follows: binder: nitrogen-containing organic compound: oxidizing agent = 1 : 2 to 108: 6 to 165. Ma When the component further contains a slag forming agent, the range of each composition (weight ratio) is as follows: binder: nitrogen-containing organic compound: oxidizing agent: slag forming agent = 1: 2 to 108: 6 to: L It is preferably 65: 0.1 to 12.

The gas generating composition of the present invention can be formed into a molded article having a desired shape so that the gas generating composition (inflation overnight) can be filled. The shape of the molded body is not particularly limited. For example, a gas generating composition comprising a fuel component, an oxidizing agent, a slag forming agent, a combustion controlling agent, a binder other than the binder of the present invention, and the like may be used. A binder is added to a content of 0.5 to 10% by weight, and water or an organic solvent (for example, methanol, ethanol, etc.) is further added according to each component, uniformly mixed, kneaded, and extruded. And a pellet-shaped molded body obtained by using a tableting machine or the like.

In particular, since the binder of the present invention is very suitable for extrusion molding, it is preferable that the gas generant composition of the present invention using the binder is molded by extrusion.

INDUSTRIAL APPLICABILITY The gas generating composition of the present invention can be applied to a micro gas generating agent for airbag inflation in a driver's seat, airbag inflation in a passenger seat, side inflation in a passenger seat, and a seat belt pretensioner. Applicable to overnight lid inflation. Since the gas generating composition of the present invention has a high gas generation efficiency and a small amount of generated residue, the number of filters passing through the residue can be reduced, and the inflation rate can be reduced.

According to the method of the present invention, the above-mentioned gas generating composition is burned as fuel in a gas generator, and the air bag is inflated using the gas generated by the burning.

Further, in the seatbelt pretensioner, the above-described gas generating composition is burned as fuel in a gas generator, and the seatbelt is rolled up by using the gas generated by the combustion so that the seatbelt is not extended. Example

Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to these examples. A gas generating composition was prepared according to the composition and composition ratio (weight ratio) in Table 1 (Example 1).

-5 and Comparative Examples 1-5), the heat loss test (107 C, 400 hours) and the weight loss (minus%) after the thermal shock test (one 40 ° C to 100 ° C, 200 times) were measured. The heat resistance test was performed using a high-temperature (heat resistance) test device manufactured by Tabai Espec Corporation, and the thermal shock test was performed using a thermal shock (temperature resistance) test device manufactured by Tabai Espec Corporation. The results are shown in Table 1.

Composition Composition ratio Heat resistance test Thermal shock test Example 1 C-PAM / A-PAM / HPMC / 0.5 / 0.5 / 1.7 / -0.02¾ -0.01%

GN / PSAN / SrN / bcN 46.5 / 9.6 / 32.3 / 8.9

Comparative Example 1 HPMC / GN / PSAN / SrN / 2.7 / 46.5 / 9.6 / 32.3 / -0.07% -0.28% bcN 8.9

Example 2 C-PAM / A-PAM / HPMC / I.0 / 1.0 / 3.4 / 0.00% 0.00%

BHT2NH3 / PSAN / SrN 13.8 / 78.1 / 2.7

Comparative Example 2 HPMC / BHT2NH3 / 10.0 / 12.2 / -0.02% -0.02%

PSAN / SrN 75.1 / 2.7

Example 3 C-PAM / A-PAM / GUARGUM / 0.5 / 0.5 / 3.0 / -0.06¾ 0.00%

NQ / GN / SrN / KN / SiN 26.8 / 17.4 / 42.9 / 5.4 / 3.5

Comparative Example 3 GUARGUM / NQ / GN / 4.0 / 26.8 / 17.4 / -0.34% -0.04%

SrN / KN / SiN 42.9 / 5.4 / 3.5

Example 4 C-PAM / A-PAM / MC / GN / 0.5 / 0.5 / 2.0 / 43.9 / -0.04¾ 0.00%

SrN / bcN / AC 27.2 / 23.9 / 2

Comparative Example 4 MC / GN / SrN / bcN 3.0 / 43.9 / 27.2 / 23.9 —0.20% 0.00%

/ AC / 2

Example 5 C-PAM / A-PAM / MC / GN / 0.5 / 0.5 / 3.0 / 40.6 / -0.02% -0.02%

ATZ / SrN / AP II.8 / 13.8 / 29.8

Comparative Example 5 MC / GN / ATZ / 4.0 / 40.6 / 11.8 / -0.11% -0.09%

SrN / AP 13.8 / 29.8 According to Table 1, like the gas generating composition of the present invention, the smaller the weight loss, the more heat stable.

In Table 1, CPAM has a colloid equivalent value (cationic degree) of +2.5 meq. Z-gram cationic polyacrylamide, and A-PAM has a colloid equivalent value (anionic degree) of -2.5 meq. Per gram of anionic polyacrylamide, HPMC stands for hydroxypropylmethylcellulose, MC stands for methylcellulose, NQ stands for nitroguanidine, BHT 2 NH3 stands for bitetrazolodiammonium salt, GN stands for guanidine nitrate, ATZ stands for 5-aminotetrazole, PSAN stands for phase Stabilized ammonium nitrate, SrN indicates strontium nitrate, bcN indicates basic copper nitrate, KN indicates potassium nitrate, AP indicates ammonium perchlorate, SiN indicates silicon nitride, and AC indicates acid clay. Industrial applicability

As described above, the gas generant composition of the present invention using the binder of the present invention is excellent in heat stability and the like.

Claims

The scope of the claims

1. A binder for a gas generant comprising a mixture of a cationic polymer compound and an anionic polymer compound.

2. Cationic high molecular weight compound consisting of at least one selected from the group consisting of cationic polyacrylamide, cationic polybiol alcohol and cationic methylcellulose, sodium polyacrylate, anionic polyacrylamide, and cationic polyvinyl A binder for a gas generating agent, comprising: an anionic polymer compound comprising at least one selected from the group consisting of an alcohol and an anionic methyl cellulose;

3. A gas generating composition using the binder for a gas generating agent according to claim 1 or 2.

4. A gas generating composition comprising the binder for a gas generating agent according to claim 1 or 0.5 to 1.0% by weight.

5. A method for inflating an airbag using a generated gas obtained by burning the gas generating composition according to claim 3 or 4.