[go: up one dir, main page]

WO2006050442A2 - Compositions generant des gaz - Google Patents

Compositions generant des gaz Download PDF

Info

Publication number
WO2006050442A2
WO2006050442A2 PCT/US2005/039699 US2005039699W WO2006050442A2 WO 2006050442 A2 WO2006050442 A2 WO 2006050442A2 US 2005039699 W US2005039699 W US 2005039699W WO 2006050442 A2 WO2006050442 A2 WO 2006050442A2
Authority
WO
WIPO (PCT)
Prior art keywords
tetrazole
salt
poly
vinyl
bis
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/US2005/039699
Other languages
English (en)
Other versions
WO2006050442A3 (fr
Inventor
Cory G. Miller
Graylon K. Williams
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Automotive Systems Laboratory Inc
Original Assignee
Automotive Systems Laboratory Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Automotive Systems Laboratory Inc filed Critical Automotive Systems Laboratory Inc
Priority to DE112005002728T priority Critical patent/DE112005002728T5/de
Priority to JP2007539332A priority patent/JP2008518872A/ja
Publication of WO2006050442A2 publication Critical patent/WO2006050442A2/fr
Anticipated expiration legal-status Critical
Publication of WO2006050442A3 publication Critical patent/WO2006050442A3/fr
Ceased legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C06—EXPLOSIVES; MATCHES
    • C06B—EXPLOSIVES OR THERMIC COMPOSITIONS; MANUFACTURE THEREOF; USE OF SINGLE SUBSTANCES AS EXPLOSIVES
    • C06B45/00—Compositions or products which are defined by structure or arrangement of component of product
    • C06B45/04—Compositions or products which are defined by structure or arrangement of component of product comprising solid particles dispersed in solid solution or matrix not used for explosives where the matrix consists essentially of nitrated carbohydrates or a low molecular organic explosive
    • C06B45/06—Compositions or products which are defined by structure or arrangement of component of product comprising solid particles dispersed in solid solution or matrix not used for explosives where the matrix consists essentially of nitrated carbohydrates or a low molecular organic explosive the solid solution or matrix containing an organic component
    • C06B45/10—Compositions or products which are defined by structure or arrangement of component of product comprising solid particles dispersed in solid solution or matrix not used for explosives where the matrix consists essentially of nitrated carbohydrates or a low molecular organic explosive the solid solution or matrix containing an organic component the organic component containing a resin
    • C—CHEMISTRY; METALLURGY
    • C06—EXPLOSIVES; MATCHES
    • C06D—MEANS FOR GENERATING SMOKE OR MIST; GAS-ATTACK COMPOSITIONS; GENERATION OF GAS FOR BLASTING OR PROPULSION (CHEMICAL PART)
    • C06D5/00—Generation of pressure gas, e.g. for blasting cartridges, starting cartridges, rockets
    • C06D5/06—Generation of pressure gas, e.g. for blasting cartridges, starting cartridges, rockets by reaction of two or more solids

Definitions

  • the present invention relates generally to gas generating systems, and to gas generant compositions employed in gas generator devices for automotive restraint systems, for example.
  • the present invention relates to nontoxic gas generating compositions that upon combustion rapidly generate gases that are useful for inflating occupant safety restraints in motor vehicles and specifically, the invention relates to thermally stable nonazide gas generants having not only acceptable burn rates, but that also, upon combustion, exhibit a relatively high gas volume to solid particulate ratio at acceptable flame temperatures.
  • the evolution from azide-based gas generants to nonazide gas generants is well-documented in the prior art.
  • the advantages of nonazide gas generant compositions in comparison with azide gas generants have been extensively described in the patent literature, for example, U.S. Pat. Nos.
  • pyrotechnic nonazide gas generants contain ingredients such as oxidizers to provide the required oxygen for rapid combustion and reduce the quantity of toxic gases generated, a catalyst to promote the conversion of toxic oxides of carbon and nitrogen to innocuous gases, and a slag forming constituent to cause the solid and liquid products formed during and immediately after combustion to agglomerate into filterable clinker-like particulates.
  • oxidizers to provide the required oxygen for rapid combustion and reduce the quantity of toxic gases generated
  • a catalyst to promote the conversion of toxic oxides of carbon and nitrogen to innocuous gases
  • a slag forming constituent to cause the solid and liquid products formed during and immediately after combustion to agglomerate into filterable clinker-like particulates.
  • Other optional additives such as burning rate enhancers or ballistic modifiers and ignition aids, are used to control the ignitability and combustion properties of the gas generant.
  • nonazide gas generant compositions One of the disadvantages of known nonazide gas generant compositions is the amount and physical nature of the solid residues formed during combustion. When employed in a vehicle occupant protection system, the solids produced as a result of combustion must be filtered and otherwise kept away from contact with the occupants of the vehicle. It is therefore highly desirable to develop compositions that produce a minimum of solid particulates while still providing adequate quantities of a nontoxic gas to inflate the safety device at a high rate.
  • phase stabilized ammonium nitrate as an oxidizer, for example, is desirable because it generates abundant nontoxic gases and minimal solids upon combustion.
  • gas generants for automotive applications must be thermally stable when aged for 400 hours or more at 107 degrees C.
  • compositions must also retain structural integrity when cycled between -40 degrees C and 107 degrees C. Further, gas generant compositions incorporating phase stabilized or pure ammonium nitrate sometimes exhibit poor thermal stability, and produce unacceptably high levels of toxic gases, CO and NO x for example, depending on the composition of the associated additives such as plasticizers and binders. Furthermore, recent revisions in U.S. car requirements require relatively minimal amounts of ammonia in the effluent gases.
  • Yet another concern includes slower cold start ignitions of typical smokeless gas generant compositions, that is gas generant compositions that result in less than 10% of solid combustion products.
  • gas generating systems including a gas generant composition containing an extrudable polyvinylazole fuel such as a polyvinyltetrazole, polyvinyltriazole, or polyvinyldiazole.
  • Preferred oxidizers include nonmetal oxidizers such as ammonium nitrate and ammonium perchlorate.
  • Other oxidizers include alkali and alkaline earth metal nitrates.
  • the fuel is selected from the group of polyvinyltetrazoles, polyvinyltriazoles, polyvinyldiazoles, and polyvinylfurazans, and mixtures thereof.
  • An exemplary group of fuels includes polymeric tetrazoles, triazoles, and oxadiazoles (furazans), having functional groups on the azole pendants.
  • Preferred vinyl tetrazoles include 5-Amino-1 -vinyltetrazole and poly(5- vinyltetrazole), both exhibiting self-propagating thermolysis or thermal decomposition.
  • Other fuels include poly(2-methyl-5-vinyl) tetrazole, polyd -vinyl) tetrazole, poly(3-vinyl) 1 ,2,5- oxadiazole, and poly(3-vinyl) 1 ,2,4-triazole. These and other possible fuels are structurally illustrated in the figures included herewith.
  • the polyvinylazoles may exhibit pendant aromaticity, or, aromatic character within the polymer backbone, depending on the design criteria of the gas generant composition, and depending on the starting reagents in the synthesis of the polyvinylazole.
  • the fuel may typically constitute about 5-40% by weight of the gas generant composition.
  • An oxidizer is preferably selected from the group of nonmetal, and alkali and alkaline earth metal nitrates, and mixtures thereof.
  • Nonmetal nitrates include ammonium nitrate and phase stabilized ammonium nitrate, stabilized as known in the art.
  • Alkali and alkaline earth metal nitrates include potassium nitrate and strontium nitrate.
  • Other oxidizers known for their utility in air bag gas generating compositions are also contemplated.
  • the oxidizer may typically constitute about 60-95% by weight of the gas generant composition.
  • gas generant constituents known for their utility within vehicle occupant protection systems, and within gas generant compositions typically contained therein, may be employed in functionally effective amounts in the compositions of the present invention. These include, but are not limited to, coolants, slag formers, and ballistic modifiers known in the art.
  • the present invention includes gas generant compositions that maximize gas combustion products and minimize solid combustion products while retaining other design requirements such as thermal stability.
  • FIG. 1 is a cross-sectional side view showing the general structure of an inflator in accordance with the present invention
  • FIG. 2 is a schematic representation of an exemplary vehicle occupant restraint system containing a gas generant composition in accordance with the present invention.
  • FIG. 3 and FIG. 4 are graphical representations of respective burn rates compared to combustion pressure of gas generant compositions.
  • FIG. 5 and FIG. 6 are graphical representations indicating combustion profiles of the same gas generant before and after aging for 400 hours at 107 C.
  • a pyrotechnic composition includes extrudable fuels such as polyvinyltetrazoles (PVT) for use within a gas generating system, such as that exemplified by a high gas yield automotive airbag propellant in a vehicle occupant protection system.
  • PVT polyvinyltetrazoles
  • the fuel also functions as a binder.
  • Preferred oxidizers include nonmetal oxidizers such as ammonium nitrate and ammonium perchlorate. Other oxidizers include alkali and alkaline earth metal nitrates.
  • the fuel is selected from the group of polyvinyltetrazoles, polyvinyltriazoles, polyvinyldiazoles or polyvinylfurazans, and mixtures thereof.
  • An exemplary group of fuels includes polymeric tetrazoles, triazoles, and oxadiazoles (furazans), optionally having functional groups on the azole pendants.
  • Vinyl tetrazoles include 5-Amino-1 -vinyltetrazole and poly(5-vinyltetrazole), both exhibiting self-propagating thermolysis or thermal decomposition.
  • Other fuels include poly(2-methyl-5-vinyl) tetrazole, polyd -vinyl) tetrazole, poly(3-vinyl) 1 ,2,5-oxadiazole, and poly(3-vinyl) 1 ,2,4-triazole. These and other possible fuels are exemplified by, but not limited to, the structures shown below.
  • compositions resulting in difficult cold-start ignitions that necessitate more powerful ignition trains and boosters are avoided.
  • Poly(5-amino-1 -vinyl) tetrazole for example, is believed to have no endothermic process before exothermic decomposition begins. Therefore, the heat-consuming step normally attendant prior to the energy releasing steps of combustion (that acts as an energy barrier), is apparently not present in the present compositions. It is believed that other polymeric azoles functioning as fuels in the present invention have the same benefit.
  • the polyvinylazole fuel or the total fuel component of the gas generant composition may typically constitute about 5-40% by weight of the gas generant composition.
  • An oxidizer is preferably selected from the group of nonmetal, and alkali and alkaline earth metal nitrates, and mixtures thereof.
  • Nonmetal nitrates include phase stabilized ammonium nitrate, stabilized as known in the art for example.
  • Alkali and alkaline earth metal nitrates include potassium nitrate and strontium nitrate. It has been found that in accordance with the present invention, compositions containing phase stabilized ammonium nitrate exhibit sufficient thermal stability, in contrast to many other known compositions containing unstabilized ammonium nitrate and/or phase stabilized ammonium nitrate.
  • Other oxidizers known for their utility in air bag gas generating compositions are also contemplated.
  • the oxidizers of the present invention provide an overall oxygen balance within the combustion reaction to minimize the production of carbon monoxide and/or nitrogen oxides.
  • the oxygen balance of the present invention as determined by the oxidizer provided ranges from -4.0% to + 4.0%. It will be appreciated that in gun propellents for example, the amount of oxygen balance purposefully results in carbon monoxide upon combustion of the respective gun propellant thereby providing the required thrust with the lowest possible molecular weight gases.
  • the oxidizer or the total oxidizer component may typically constitute about 60-95% by weight of the gas generant composition.
  • gas generant constituents known for their utility in air bag gas generant compositions may be employed in functionally effective amounts in the compositions of the present invention. These include, but are not limited to, coolants, slag formers, and ballistic modifiers known in the art.
  • the gas generant constituents of the present invention are supplied by suppliers known in the art and are preferably blended by a wet method. Typical or known suppliers include Aldrich or Fisher Chemical companies.
  • a solvent chosen with regard to the group(s) substituted on the polymeric fuel is heated to a temperature sufficient to dissolve the fuel but below boiling, for example just below 100 0 C, but low enough to prevent autoignition of any of the constituents as they are added and then later precipitate.
  • Hydrophilic groups for example, may be more efficiently dissolved by the use of water as a solvent. Other groups may be more efficiently dissolved in an acidic solution, nitric acid for example.
  • Other solvents include alcohols and plasticizers such as polyethylene glycol. Once a suitable solvent is chosen and heated, the fuel is slowly added and dissolved.
  • the oxidizer is then slowly added and also at least partially dissolved. Any other desirable constituents are likewise dissolved.
  • the solution is heated and continually stirred. As the solvent is evaporated off over time, the fuel and oxidizer, and any other constituents, are co- precipitated in a homogeneous solid solution. The precipitate is removed from the heat once the solvent has been at least substantially volatilized, but more preferably completely volatilized.
  • the composition may then be extruded into pellets or any other useful shape.
  • the polymeric fuels may be manufactured by known processes. For example, vinylation of a tetrazole with vinyl acetate, followed by polymerization is described in Vereshchagin, et al., J. Org. Chem. USSR (Engl.
  • Reaction 1 This synthesis illustrates the production of poly(vinyl-1 ,2,5-oxadiazole) and exemplifies or blueprints a general method of forming polyvinyldiazoles.
  • Reaction 2 This synthesis illustrates the production of an ionic polymer version of poly(vinyl- 1 ,2,4-triazole) and exemplifies or blueprints a method of forming other polyvinyltriazoles.
  • Reaction 3 This synthesis illustrates the production of a substituted polyvinyltetrazole and exemplifies or blueprints a method of forming other polyvinyltetrazoles.
  • a generic polyvinylazole or a structure that generically represents the polyvinyltetrazoles, polyvinyltriazoles, and polyvinyldiazoles of the present invention, may be represented by an aromatic ring having five cites that contain.
  • VJ should contain: at least 1 carbon atom
  • the aromatic ring will contain from zero to a single oxygen atom, will contain at least two nitrogen atoms, and will contain at least one carbon atom.
  • a gas generant composition of the present invention will contain a polymeric azole and phase stabilized ammonium nitrate. The advantages are high gas yield and low solids production, a high energy fuel/binder, and a low-cost oxidizer thereby obviating the need for filtration of the gas given that little if any solids are produced upon combustion.
  • the compositions of the present invention may be extruded given the pliant nature of the polymeric fuels.
  • the gas generant compositions of the present invention may also contain a secondary fuel formed from amine salts of tetrazoles and triazoles. These are described and exemplified in co-owned U.S. Patent Nos. 5,872,329, 6,074,502, 6,210,505, and 6,306,232, each herein incorporated by reference.
  • the total weight percent of both the first and second fuels, or the fuel component of the present compositions is about 10 to 40 weight% of the total gas generant composition.
  • the use of a secondary fuel provides enhanced burn rates as pressure increases.
  • nonmetal salts of tetrazoles and triazoles include in particular, amine, amino, and amide salts of tetrazole and triazole selected from the group including monoguanidinium salt of 5,5'-Bis-1 H-tetrazole (BHT- 1 GAD), diguanidinium salt of 5,5'-Bis-1 H- tetrazole (BHT-2GAD), monoaminoguanidinium salt of 5,5'-Bis-1 H-tetrazole (BHT- 1 AGAD), diaminoguanidinium salt of 5,5'-Bis-1 H-tetrazole (BHT-2AGAD), monohydrazinium salt of 5,5'- Bis-1 H-tetrazole (BHT- 1 HH), dihydrazinium salt of 5,5'-Bis-1 H-tetrazole (BHT-2HH), monoammonium salt of 5,5'-bis-1 H-tetrazole (BHT-I NH 3 ),
  • Amine salts of triazoles include monoammonium salt of 3-nitro-1 ,2,4-triazole (NTA- I NH 3 ), monoguanidinium salt of 3-nitro-1 ,2,4-triazole (NTA-1 GAD), diammonium salt of dinitrobitriazole (DNBTR-2NH 3 ), diguanidinium salt of dinitrobitriazole (DNBTR-2GAD), and monoammonium salt of 3,5-dinitro-1 ,2,4-triazole (DNTR-I NH 3 ).
  • a generic nonmetal salt of tetrazole as shown in Formula I includes a cationic nitrogen containing component, Z, and an anionic component comprising a tetrazole ring and an R group substituted on the 5-position of the tetrazole ring.
  • a generic nonmetal salt of triazole as shown in Formula Il includes a cationic nitrogen containing component, Z, and an anionic component comprising a triazole ring and two R groups substituted on the 3- and 5- positions of the triazole ring, wherein R 1 may or may not be structurally synonymous with R 2 .
  • R component is selected from a group including hydrogen or any nitrogen-containing compound such as an amino, nitro, nitramino, or a tetrazolyl or triazolyl group as shown in Formula I or II, respectively, substituted directly or via amine, diazo, or triazo groups.
  • the compound Z is substituted at the 1 -position of either formula, and is formed from a member of the group comprising amines, aminos, and amides including ammonia, carbohydrazide, oxamic hydrazide, and hydrazine; guanidine compounds such as guanidine, aminoguanidine, diaminoguanidine, triaminoguanidine, dicyandiamide and nitroguanidine; nitrogen substituted carbonyl compounds or amides such as urea, oxamide, bis-(carbonamide) amine, azodicarbonamide, and hydrazodicarbonamide; and, amino azoles such as 3-amino-1 ,2,4-triazole, 3-amino-5-nitro-1 ,2,4- triazole, 5-aminotetrazole, 3-nitramino-1 ,2,4-triazole, 5-nitraminotetrazole, and melamine.
  • guanidine compounds such as guanidine, amino
  • a gas generant composition of the present invention is formed by first synthesizing a polyvinyltetrazole.
  • a generic substituted tetrazole and vinyl acetate are combined to vinylate the tetrazole.
  • the vinylated tetrazole is added to a molar equivalent of mercury acetate and boron trifluoride-etherate for polymerization thereof.
  • the resulting products may then be separated by oil distillation for example.
  • the polyvinyltetrazoles illustrated in the drawings may j>e formed in the same generic way. Reaction 3 exemplifies the process described above.
  • Example 2 A gas generant composition of the present invention is formed by first synthesizing a polyvinyltriazole.
  • a generic substituted triazole metal or nonmetal salt is added to a molar equivalent amount of a free radical brominating reagent such as n-bromo- succinamide and to a benzoyl-peroxide free radical initiator to form a brominated triazole.
  • the brominated triazole is then added to triphenyl phosphine to form a Wittig salt group on the substituted triazole salt.
  • the triazole salt is then added to a metal or nonmetal organic or inorganic base, and also to formaldehyde to form a vinylated triazole salt.
  • the vinylated triazole salt is next added to a free radical polymerization reagent such as azoisobutyronitrile and a catalytic amount of a cationic polmerizer or Ziegler-ISIatta catalyst such as a metal or titanium complex.
  • Reaction 2 exemplifies the process described above, wherein the synthesis of poly(vinyl-1 ,2,4-triazole) is shown.
  • a gas generant composition of the present invention is formed by first synthesizing a polyvinyldiazole. An alkenol containing two -OH groups is added to acetic anhydride to form a substituted diazole. The substituted diazole is then added to a molar equivalent amount of a free radical brominating reagent such as n-bromo-succinamide and to a free radical initiator such as benzoyl-peroxide to form a brominated diazole. The substituted diazole is then added to triphenyl phosphine to form a Wittig salt group on the substituted diazole salt.
  • a free radical brominating reagent such as n-bromo-succinamide
  • a free radical initiator such as benzoyl-peroxide
  • the diazole salt is then added to a metal or nonmetal organic or inorganic base, and also to formaldehyde to form a vinylated diazole salt.
  • the vinylated diazole salt is next added to a free radical polymerization reagent such as azoisobutyronitrile and a catalytic amount of a cationic polymerizer or Ziegler-Natta reagent such as a metal complex. Reaction
  • Examples 4-9 are tabulated below and provide a comparative view of the different types and amounts of gas produced with regard to several known gas generant compositions and a gas generant formed in accordance with the present invention.
  • Example 4 is a representative gas generant composition formed from 5-aminotetrazole and strontium nitrate, in accordance with U.S. Patent No. 5,035,757 herein incorporated by reference.
  • Example 5 is a representative gas generant composition formed from an amine salt of tetrazole such as diammonium salt of 5,5'-bi-1 H-tetrazole, phase stabilized ammonium nitrate, strontium nitrate, and clay in accordance with U.S. Patent No.
  • Example 6 is a representative gas generant composition formed from an amine salt of tetrazole such as diammonium salt of 5,5'-bi-1 H-tetrazole and phase stabilized ammonium nitrate in accordance with U.S. Patent No. 5,872,329 herein incorporated by reference.
  • Example 7 is a representative gas generant composition formed from ammonium nitramine tetrazole and phase stabilized ammonium nitrate in accordance with U.S. Patent No. 5,872,329 herein incorporated by reference.
  • Example 8 is a representative gas generant composition formed from ammonium nitramine tetrazole, phase stabilized ammonium nitrate, and a slag former in accordance with U.S. Patent No. 5,872,329 herein incorporated by reference.
  • Example 9 is a representative composition formed in accordance with the present invention containing ammonium polyvinyl tetrazole at 1 5% by weight and phase stabilized ammonium nitrate at about 85% by weight (ammonium nitrate coprecipitated with 10% potassium nitrate).
  • Table 1 details the relative amounts produced (ppm) of carbon monoxide (CO), ammonia (NH3), nitrogen monoxide (NO), and nitrogen dioxide (NO2) with regard to each example and the amount of gas generant in grams (g). All examples were combusted in a gas generator of substantially the same design.
  • compositions of Example 9 result in far less ammonia than the other examples, well below the industry standard of 35 ppm. It has been discovered that compositions of the present invention result in substantially less amounts of ammonia as compared to other known gas generants. In certain known gas generant compositions, it is often difficult to reduce the total amount of ammonia produced upon combustion, even though other performance criteria remain favorable.
  • Examples 10-14 Theoretical examples 10-14 are tabulated below and provide a comparative view of the different amounts and types of gas produced with regard to several gas generant compositions formed in accordance with the present invention.
  • All phase stabilized ammonium nitrate (PSAN10) referred to in Table 2 has been stabilized with 10% by weight potassium nitrate of the total PSAN.
  • All examples employ ammonium poly(C-vinyltetrazole) (APV) as the primary fuel.
  • Certain examples employ nonmetal diammonium salt of 5,5'-Bis- 1 H-tetrazole (BHT.2NH3) as a secondary fuel. All examples reflect results generated by combustion of the gas generant constituents (propellant composition) within a similarly designed inflator or gas generator with equivalent heat sink design.
  • Example 10 has been found to be thermally stable at 107 degrees Celsius for 400 hours with only a .5% mass loss. Accordingly, Example 10 exemplifies the unexpected thermal stability of gas generant compositions of the present invention, particularly those incorporating a polyvinylazole as defined herein and phase stabilized ammonium nitrate (stabilized with 10% potassium nitrate). It should be emphasized that other phase stabilizers are also contemplated as known or recognized in the art.
  • Examples 1 1 through 13 exemplify the use of a polyvinylazole with metallic oxidizers.
  • the use of a metallic oxidizer may be desired for optimization of ignitability, burn rate exponent, gas generant burn rate, and other design criteria.
  • the examples illustrate that the more metallic oxidizer is used the less mols of gas produced upon combustion.
  • Examples 10 and 14 illustrate that molar amounts of gas combustion products are maximized when nonmetal gas generant constituents are employed. Accordingly, preferred gas generant compositions of the present invention contain at least one polyvinylazole as a fuel component and a nonmetal oxidizer as an oxidizer component. Finally, with regard to Example 14, it has been found that the gas generant burn rate may be enhanced by adding another nonmetal fuel, BHT.2NH3, to APV and PSAN 10, thereby optimizing the combustion profile of the gas generant composition. The burn rate of Example 14 is recorded at 1 .2 inches per second at 5500 psi.
  • Figure 4 illustrates the burn rates over pressure of a similar composition of Figure 3 containing polyvinyltetrazole and phase stabilized ammonium nitrate, but with the addition of di-ammonium BHT, in accordance with the percent weight ranges provided herein. It can be concluded that the addition of a secondary fuel as described herein results in a significant advantage with regard to burn rate. The practical effect is repeatability of performance and enhanced ballistic properties of gas generants formed accordingly.
  • Examples 15 and 16 Examples 1 5 and 16 exemplify the cold start advantage of gas generant compositions containing a polyvinylazole. As indicated by differential scanning calorimetry (DSC), typical smokeless or nonmetal compositions may exhibit an endothermic trend prior to exothermic combustion. As a result, relatively greater amounts of energy must be available to ignite the gas generant and sustain combustion of the same. Oftentimes, a more aggressive ignition train, to include an aggressive booster composition perhaps, is required to attain the energy level necessary to ignite the gas generant and sustain combustion.
  • Example 1 5 pertains to a composition containing 65% PSAN10 and about 35% BHT.2NH3.
  • Example 16 pertains to a composition containing about 1 5% poly(C-vinyltetrazole) and about 85% PSAN10. Most unexpectedly, there is no endothermic process as indicated by DSC and accordingly, combustion proceeds in an uninhibited manner. As a result, less energy is required to combust the gas generant composition thereby reducing the ignition train or ignition and booster requirements.
  • Example 17 Another advantage of the present invention is illustrated in Figures 5 and 6.
  • Figure 5 illustrates baseline, or pre-aged combustion of a gas generating composition made in accordance with the present invention, within a state-of-the-art gas generator.
  • the gas generating composition contained 80.6% PSAN, 8.0% PVT, and 1 1 .4% BHT-2NH3.
  • Figure 6 illustrates post-aged combustion of the same gas generating composition within the same gas generator.
  • the curves indicated in Figures 5 and 6 correlate to "hot” or + 85 C, "ambient” or 23 C, and “cold” or -40 C deployments of standard driver side inflators within a 60 liter ballistics tank.
  • USCAR specifications for "accelerated aging" are 400 hours at 107 C. Typically, many car manufacturers worldwide require similar accelerated aging criteria.
  • the present compositions may be employed within a gas generating system.
  • a vehicle occupant protection system made in a known way contains crash sensors in electrical communication with an airbag inflator in the steering wheel, and also with a seatbelt assembly.
  • the gas generating compositions of the present invention may be employed in both subassemblies within the broader vehicle occupant protection system or gas generating system. More specifically, each gas generator employed in the automotive gas generating system may contain a gas generating composition as described herein.
  • Exemplary gas generant compositions include poly(c-vinyltetrazole) as a fuel/binder at 5-40%, and more preferably 5-20%.
  • weight percents provided for each of the constituents given below may be applicable to any polyvinylazole incorporated within the present invention.
  • Various poly(c-vinyltetrazoles) may be made by the water- based method of manufacture described below.
  • the fuel/binder poly(c-vinyltetrazoles) may be formed as described in U.S. Patent No. 3,096,312, herein incorporated by reference, for example.
  • the polyvinyltetrazole salts may be either metallic or nonmetallic in character, whereby nonmetallic salts are preferred, but not limited thereby, due to the production of more gas and less solids.
  • the functionalization of the polymer is exemplified by the diagram of the PVT acid form given above.
  • the pseudo-allylic carbon at position 1 of the backbone could possibly be functionalized with nitro or nitroso groups. This position could be functionalized with anything that makes the oxygen balance less negative or adds a source of fuel. This position may also be functionalized with any group to increase its materials properties (i.e. plasticity) such as a vinyl group for crosslinking (curing).
  • the nitrogen at position 2 is acidic with a preferable pKa of between 3-5.
  • the attached hydrogen can therefore by removed with a mild base, leaving an aromatic tetrazole ring anion.
  • Any suitable base can be used to make a water-soluble salt of the polymer as given in the water-based method described below.
  • This position could also be functionalized with any group, to again, make the oxygen balance of the system less negative or to add more fuel.
  • This position could also be functionalized with any group to impart a desired materials property to the system, such as a vinyl group for crosslinking.
  • a primary oxidizer is selected from the group including nitrate salts such as phase-stabilized ammonium nitrate, alkali and alkaline earth metal potassium nitrate, strontium nitrate; nitrite salts such as potassium nitrite; chlorate salts such as potassium chlorate; perchlorate salts such as potassium perchlorate; oxides such as iron oxide and copper oxide; basic nitrate salts such as basic copper nitrate and basic iron nitrate; and mixtures or combinations thereof.
  • the oxidizer component of the present invention typically constitutes 60 - 95% of the total composition.
  • a secondary fuel may be selected from amine salts of tetrazoles and triazoles as given above, and may also be selected from azoles such as tetrazoles, triazoles, and furazans, such as 5-aminotetrazole; metal salts of azoles such as potassium 5-aminotetrazole; nonmetal salts of azoles such as mono- or di-ammonium salt of 5,5'-bis-1 H-tetrazole; nitrate salts of azoles such as 5-aminotetrazole nitrate; nitramine derivatives of azoles such as 5- nitraminotetrazole; metal salts of nitramine derivative of azoles such as dipotassium 5- nitraminotetrazole; nonmetal salts of nitramine derivatives of azoles such as mono- or di- ammonium 5-nitraminotetrazole; and, guanidines such as dicyandiamide; salts of guan
  • the secondary fuel in combination with the primary polyvinylazole fuel typically constitutes about 5-40% by weight of the total composition as a fuel component thereof.
  • the primary fuel constitutes about 13-100% of the fuel component (or about 5-40% by weight of the total composition), and the secondary fuel constitutes about 0-87% (or about 0-35% by weight of the total composition).
  • a slag former may be selected from the group including silicon compounds such as elemental silicon, and silicon dioxide; silicones such as polydimethylsiloxane; silicates such as potassium silicates; natural minerals such as talc, mica, and clay; and mixtures thereof.
  • the slag former preferably constitutes 0-10% and more preferably constitutes 0-5% of the total composition.
  • Extrusion aides may be selected from the group including talc, graphite, borazine [(BN) 3 ], boron nitride, fumed silica, and fumed alumina.
  • the slag former preferably constitutes 0-10% and more preferably constitutes 0-5% of the total composition.
  • compositions may be dry or wet mixed using methods known in the art.
  • the various constituents are generally provided in particulate form and mixed to form a uniform mixture with the other gas generant constituents.
  • the mixture is then palletized or formed into other useful shapes in a safe manner known in the art.
  • Preferred gas generant compositions include 60-95% by weight of phase-stabilized ammonium nitrate (10-1 5% KNO3) and 5-40% by weight of a nonmetal poly(c-vinyltetrazole).
  • a gas generant composition may include 85% by weight of phase-stabilized ammonium nitrate and 15% by weight of ammonium poly(c-vinyltetrazole).
  • An even more preferred gas generant composition includes about 8% ammonium poly(c-vinyltetrazole), about 1 1 % diammonium salt of 5,5'-bis-1 H-tetrazole, and about 81 % phase-stabilized ammonium nitrate.
  • an exemplary inflator incorporates a dual chamber design to tailor the force of deployment an associated airbag.
  • an inflator containing a primary gas generant 12 and an autoignition composition 14 formed as described herein may be manufactured as known in the art.
  • U.S. Patent Nos. 6,422,601 , 6,805,377, 6,659,500, 6,749,219, and 6,752,421 exemplify typical airbag inflator designs and are each incorporated herein by reference in their entirety.
  • Airbag system 200 includes at least one airbag 202 and an inflator 10 containing a gas generant composition 12 in accordance with the present invention, coupled to airbag 202 so as to enable fluid communication with an interior of the airbag.
  • Airbag system 200 may also include (or be in communication with) a crash event sensor 210.
  • Crash event sensor 210 includes a known crash sensor algorithm that signals actuation of airbag system 200 via, for example, activation of airbag inflator 10 in the event of a collision.
  • FIG. 2 shows a schematic diagram of one exemplary embodiment of such a restraint system.
  • Safety belt assembly 150 includes a safety belt housing 152 and a safety belt 100 extending from housing 152.
  • a safety belt retractor mechanism 1 54 (for example, a spring-loaded mechanism) may be coupled to an end portion of the belt.
  • a safety belt pretensioner 156 containing propellant 12 and autoignition 14 may be coupled to belt retractor mechanism 1 54 to actuate the retractor mechanism in the event of a collision.
  • Typical seat belt retractor mechanisms which may be used in conjunction with the safety belt embodiments of the present invention are described in U.S. Pat. Nos. 5,743,480, 5,553,803, 5,667,161 , 5,451 ,008, 4,558,832 and 4,597,546, incorporated herein by reference.
  • Illustrative examples of typical pretensioners with which the safety belt embodiments of the present invention may be combined are described in U.S. Pat. Nos. 6,505,790 and 6,419,177, incorporated herein by reference.
  • Safety belt assembly 1 50 may also include (or be in communication with) a crash event sensor 1 58 (for example, an inertia sensor or an accelerometer) including a known crash sensor algorithm that signals actuation of belt pretensioner 156 via, for example, activation of a pyrotechnic igniter (not shown) incorporated into the pretensioner.
  • a crash event sensor 1 58 for example, an inertia sensor or an accelerometer
  • a known crash sensor algorithm that signals actuation of belt pretensioner 156 via, for example, activation of a pyrotechnic igniter (not shown) incorporated into the pretensioner.
  • U.S. Pat. Nos. 6,505,790 and 6,419,177 previously incorporated herein by reference, provide illustrative examples of pretensioners actuated in such a manner.
  • safety belt assembly 150 airbag system 200, and more broadly, vehicle occupant protection system 180 exemplify but do not limit gas generating systems contemplated in accordance with the present invention.
  • the fuels of the present invention may be formed by a water-based method for synthesizing polyvinyltetrazoles as provided below.
  • a water-based process contains the following steps. First, a pre-polymer containing a pendant nitrile or cyano group is provided. Any pre-polymer within cyano or nitrile functionality could be used in the synthesis.
  • Examples include poly(cyanoacrylates), poly(haloacylonitriles) where the halogen can be fluorine, chlorine, bromine, or iodide, poly(crotonitriles), polyftriallyl cyanurates), cellulose cyanoethyl ethers, and poly(methacrylonitriles).
  • Certain copolymers or block copolymers containing nitrile functionality are also contemplated for use as a pre-polymer. These copolymers include poly(butadiene/acrylonitrile)s and poly(styrene/acrylonitrile)s, as well as any other polymer blends of any nitrile containing polymer or oligomer.
  • polymers and copolymers may be purchased from known manufacturers such as Polysciences, Inc. (www.polysciences.com).
  • a preferred polymeric backbone is a polyethylene chain, although any useful backbone may be employed.
  • the nitrile cannot be part of the backbone and must always be a pendant group.
  • the material may be classified as a pendant-nitrile containing pre-polymer.
  • the pre-polymer may exhibit aromatic character.
  • the pre-polymer is then reacted with a divalent zinc halide, ZnX 2 , in the presence of an azide such as sodium azide, water, and a surfactant, all under pressure at high temperature to form a polymer-bound zinc tetrazole organometallic complex.
  • the polymer intermediate complex is then filtered and washed from the reaction media and then converted to a corresponding tetrazole acid by treatment with concentrated acid.
  • the poly(tetrazole) acid can then be converted into a water soluble salt by reacting it with a suitable base. All steps in the process are carried out in water.
  • the azide can be any metallic azide such as sodium azide, for example.
  • the surfactant can be essentially any useful surfactant.
  • One exemplary surfactant is ammonium lauryl sulfate, provided by Rhodia, Inc.
  • Other surfactants include various soaps or detergents (e.g. Dial ® ), phase transfer catalysts such as quaternary ammonium salts (such as tetrabutyl ammonium bromide from Aldrich Chemical Company).
  • the zinc halide can be zinc chloride, zinc bromide, or zinc iodide.
  • the concentrated acid can be hydrogen chloride, hydrogen bromide, nitric acid, sulfuric acid, and organic acids such as acetic acid.
  • any acid may be employed that results in a polymer suspension solution having a pH of about 1 -3.
  • These acids are available from Aldrich Chemical Company, for example.
  • the base(s) employed may be selected from the group including ammonium hydroxide, hydroxylamine, hydrazine, and any other suitable amine with a pKb compatible to form a stable salt with the polymer. These bases are available from Aldrich Chemical Company, for example.
  • Process conditions may be described as follows: a 1 .0 molar equivalent of polyacrylonitrile (exemplary pre-polymer, Polysciences, Inc.) is reacted with 0.5 molar equivalents of zinc bromide dihydrate (Aldrich), 1 .1 equivalents of sodium azide (Aldrich), and 0.0025 molar equivalents of ammonium lauryl sulfate as a 28% wt% solution in water (Rhodia). The final molarity based on the amount of polymer in the water is about 1 .0.
  • An exemplary batch uses 47.7 grams of a nitrile-containing pre-polymer, 64.29 grams azide, 1 17.41 grams zinc, and 2.25 ml surfactant, all constituents mixed in 900 ml of water.
  • the ratios may vary as long as an excess of azide is present and at least 0.5 equivalents of zinc are present.
  • the amount of surfactant may also be varied ranging from no more than 0.1 equivalents and no less than 0.000001 equivalents.
  • the amount of water may vary between a 5.0 molar solution and a 0.1 molar solution. All reagents are mixed in the pressure reactor in no specific order and sealed inside. The contents are stirred and heated to 170 degrees Celsius which will reach a pressure of between 80-100 psi. The mixture is then left to react for a period of about 24-48 hours (preferably 24 hours) and then cooled to room temperature.
  • the milky contents are preferably then filtered in a buchner funnel and washed with an equal volume of water.
  • the contents are dispersed in about 1 .0 to 10.0 liters, and more preferably 3.0 liters, of cold water (ranging from 0-24 degrees Celsius) and rapidly stirred. Enough acid is added to make the pH of the suspension between 1 -3 and the mixture is continually stirred for about twenty minutes.
  • the suspension is then filtered again in a buchner funnel using a nylon screen and washed with an equivalent amount of water. This leaves a rubbery wet material in the funnel which is removed and cut into small pieces using standard scissors.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Engineering & Computer Science (AREA)
  • Combustion & Propulsion (AREA)
  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Dispersion Chemistry (AREA)
  • Molecular Biology (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Air Bags (AREA)
  • Feeding, Discharge, Calcimining, Fusing, And Gas-Generation Devices (AREA)

Abstract

L'invention concerne une composition (12) générant un gaz qui contient un polyvinylazole, ladite composition étant contenue dans un générateur de gaz (10) pris en exemple. Un système (200) de génération de gaz incorpore le polyvinylazole. Un système de protection (180) d'occupant de véhicule incorpore le système de génération de gaz (200).
PCT/US2005/039699 2004-11-01 2005-11-01 Compositions generant des gaz Ceased WO2006050442A2 (fr)

Priority Applications (2)

Application Number Priority Date Filing Date Title
DE112005002728T DE112005002728T5 (de) 2004-11-01 2005-11-01 Gaserzeugungsmittelzusammensetzungen
JP2007539332A JP2008518872A (ja) 2004-11-01 2005-11-01 ガス生成物質およびその製造法

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US62428804P 2004-11-01 2004-11-01
US60/624,288 2004-11-01

Publications (2)

Publication Number Publication Date
WO2006050442A2 true WO2006050442A2 (fr) 2006-05-11
WO2006050442A3 WO2006050442A3 (fr) 2007-05-03

Family

ID=36319805

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US2005/039699 Ceased WO2006050442A2 (fr) 2004-11-01 2005-11-01 Compositions generant des gaz

Country Status (3)

Country Link
JP (1) JP2008518872A (fr)
DE (1) DE112005002728T5 (fr)
WO (1) WO2006050442A2 (fr)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2008060366A3 (fr) * 2006-09-30 2008-10-16 Tk Holdings Inc Compositions d'agent générateur de gaz
US7692024B2 (en) 2006-05-05 2010-04-06 Tk Holdings, Inc. Gas generant compositions
US7847102B2 (en) 2006-05-05 2010-12-07 Tk Holdings, Inc. Gas generant compositions
WO2022052391A1 (fr) * 2020-09-10 2022-03-17 苏州富德兆丰生化科技有限公司 Procédé de synthèse de vortioxétine

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2023535515A (ja) * 2020-07-31 2023-08-17 ダイノ・ノーベル・アジア・パシフィック・プロプライエタリー・リミテッド 相安定化硝酸アンモニウム爆薬

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3954528A (en) * 1970-11-06 1976-05-04 The United States Of America As Represented By The Secretary Of The Navy Solid gas generating and gun propellant composition containing triaminoguanidine nitrate and synthetic polymer binder

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7692024B2 (en) 2006-05-05 2010-04-06 Tk Holdings, Inc. Gas generant compositions
US7847102B2 (en) 2006-05-05 2010-12-07 Tk Holdings, Inc. Gas generant compositions
US7914632B2 (en) 2006-05-05 2011-03-29 Tk Holdings, Inc. Gas generant compositions
US8017770B2 (en) 2006-05-05 2011-09-13 Tk Holdings, Inc. Gas generant compositions
US8088235B2 (en) 2006-05-05 2012-01-03 Tk Holdings, Inc. Gas generant compositions
WO2008060366A3 (fr) * 2006-09-30 2008-10-16 Tk Holdings Inc Compositions d'agent générateur de gaz
US8002915B2 (en) 2006-09-30 2011-08-23 Tk Holdings, Inc. Gas generant compositions
WO2022052391A1 (fr) * 2020-09-10 2022-03-17 苏州富德兆丰生化科技有限公司 Procédé de synthèse de vortioxétine

Also Published As

Publication number Publication date
WO2006050442A3 (fr) 2007-05-03
JP2008518872A (ja) 2008-06-05
DE112005002728T5 (de) 2007-09-27

Similar Documents

Publication Publication Date Title
US20100269965A1 (en) Gas generant and manufacturing method thereof
US6074502A (en) Smokeless gas generant compositions
US5872329A (en) Nonazide gas generant compositions
US6306232B1 (en) Thermally stable nonazide automotive airbag propellants
WO2006004647A9 (fr) Systeme de production de gaz
US7776169B2 (en) Water-based synthesis of poly(tetrazoles) and articles formed therefrom
US20050230017A1 (en) Gas generant compositions
US7686901B2 (en) Gas generant compositions
WO2006050442A2 (fr) Compositions generant des gaz
US7879167B2 (en) Gas generating composition
US20080099111A1 (en) Water-based synthesis of poly(tetrazoles)
JP2002519278A (ja) 高酸素バランス燃料を含んでなる着火式気体発生組成物
WO2008059318A2 (fr) Synthèse à base d'eau de poly(tétrazoles) et articles formés à partir de ceux-ci
WO2003011798A1 (fr) Liant pour agent generateur de gaz et composition d'agent generateur de gaz contenant ce liant
WO1999046222A2 (fr) Substances generatrices de gaz exempts d'azotures et possedant un rendement eleve
US20140150935A1 (en) Self-healing additive technology

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A2

Designated state(s): AE AG AL AM AT AU AZ BA BB BG BR BW BY BZ CA CH CN CO CR CU CZ DE DK DM DZ EC EE EG ES FI GB GD GE GH GM HR HU ID IL IN IS JP KE KG KM KN KP KR KZ LC LK LR LS LT LU LV LY MA MD MG MK MN MW MX MZ NA NG NI NO NZ OM PG PH PL PT RO RU SC SD SE SG SK SL SM SY TJ TM TN TR TT TZ UA UG US UZ VC VN YU ZA ZM ZW

AL Designated countries for regional patents

Kind code of ref document: A2

Designated state(s): GM KE LS MW MZ NA SD SL SZ TZ UG ZM ZW AM AZ BY KG KZ MD RU TJ TM AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LT LU LV MC NL PL PT RO SE SI SK TR BF BJ CF CG CI CM GA GN GQ GW ML MR NE SN TD TG

121 Ep: the epo has been informed by wipo that ep was designated in this application
WWE Wipo information: entry into national phase

Ref document number: 2007539332

Country of ref document: JP

WWE Wipo information: entry into national phase

Ref document number: 1120050027287

Country of ref document: DE

RET De translation (de og part 6b)

Ref document number: 112005002728

Country of ref document: DE

Date of ref document: 20070927

Kind code of ref document: P

122 Ep: pct application non-entry in european phase

Ref document number: 05824838

Country of ref document: EP

Kind code of ref document: A2