JP2010511594A - Aqueous synthesis of poly (tetrazole) s and articles formed therefrom - Google Patents

Abstract

Polyvinyl (tetrazole) is formed by an aqueous method.
A gas generant composition 12 comprising polyvinyl (tetrazole) is included in an exemplary gas generator 10.
Article or gas generation system 200 incorporates polyvinyl (tetrazole) therein.
The vehicle occupant protection system 180 incorporates a gas generation system 200.
Also described is an article or substrate 300 that includes a coating 302 formed from the product of an aqueous process.

Description

This application claims the benefit of US Provisional Application No. 60 / 704,397, filed July 31, 2005. This application is further a continuation-in-part of co-pending application number 11 / 264,982, which is a continuation-in-part of US Patent Application No.

TECHNICAL FIELD The present invention relates generally to gas generating systems and to gas generant compositions used in gas generators, for example, for automotive restraint systems. An aqueous process for producing polyvinyl (tetrazole) s is also provided. Other articles are also provided where replacement of known light emitting diodes (LEDs) and liquid crystal displays (LCDs) is contemplated.

BACKGROUND OF THE INVENTION The present invention relates to a non-toxic gas generant composition that rapidly generates gas used to inflate an automobile occupant safety restraint device upon combustion. In particular, the present invention relates to thermally stable non-azide gas generant compositions that exhibit a relatively high gas volume to solid particle ratio at an acceptable flame temperature during combustion as well as an acceptable combustion rate.

  The transition from azide-based gas generants to non-azide gas generants is well documented in the prior art. The advantages of non-azide gas generant compositions as compared to azide gas generants are, for example, U.S. Patent Nos. 4,370,181; 4,909,549; 4,948,439; 5,084,118; 5. , 139, 588 and 5,035,757. These patents are referenced and incorporated as part of this specification.

  In addition to fuel components, pyrotechnic non-azide gas generants provide the oxygen required for rapid combustion and oxidants, toxic oxidation of carbon and nitrogen to reduce the amount of toxic gases produced A catalyst that promotes the conversion of products to innocuous gases, and components such as slag-forming components that agglomerate solid and liquid products formed during and immediately after combustion into filterable clinker particulates . Other optional additives such as burn rate improvers or ballistic improvers, and ignition aids are used to control the ignition and combustion characteristics of the gas generant.

  One of the disadvantages of known non-azide gas generant compositions is the amount and physical nature of the solid residue formed during combustion. When used in a vehicle occupant protection system, the solids produced as a result of combustion must be filtered or otherwise kept out of contact with the vehicle occupant. It is therefore highly desirable to develop a composition that minimizes the production of solid particulates while providing a large amount of non-toxic gas suitable for inflating safety devices at high speeds.

  For example, it is preferable to use phase stabilized ammonium nitrate as the oxidant. This is because it produces abundant non-toxic gases and minimal amounts of solids on combustion. However, in order to be useful, gas generants for automotive applications must be thermally stable when aged at 107 ° C. for 400 hours or more. The composition must also retain structural integrity when cycled between -40 ° C and 170 ° C. Further, gas generant compositions that incorporate phase stabilized or pure ammonium nitrate sometimes exhibit poor thermal stability, depending on the composition of the accompanying additives such as plasticizers and binders, It produces unacceptably large amounts of toxic gases such as CO and NOx. In addition, recent revisions to US automotive standards require relatively small amounts of ammonia in the effluent gas. Another problem that must be addressed is that US Department of Transportation (DOT) regulations require a “cap test” for gas generants. For example, because of the sensitivity to the explosion of fuels often used with ammonium nitrate and triaminoguanidine nitrate, many propellants that incorporate ammonium nitrate will not pass the cap test without a large disk, which in turn is the flexibility of the inflator design Reduce.

  Another concern relates to the slower cold start ignition of typical smokeless gas generant compositions, which are gas generant compositions that result in less than 10% solid combustion products.

  Yet another problem involves disposal and handling of organic compounds, solvents, and mixtures used in the production of polyvinyl (tetrazole) s. The environmental impact associated with the use of organic solvents in the production of polyvinyl (tetrazoles) includes problems associated with the disposal, handling and storage of these organic compounds. The flammability of many organic compounds increases the relative risk of the manufacturing process. On the other hand, the nature of the solvent S. D. O. T.A. Requires storage and disposal in accordance with hazardous material regulations.

  Thus, ongoing efforts in the design of automotive gas production systems are devoted, for example, to those that do not have the disadvantages mentioned above, produce more gas and produce less solids.

  In another area, the need for versatile visual displays for many types of electronic products is increasing. Light emitting diodes (“LEDs”) and liquid crystal displays (“LCDs”) have found many useful applications, but are not appropriate in all cases. A visual display that has been developed relatively recently and has shown many possibilities is an organic electroluminescent device. An electroluminescent device basically consists of an electroluminescent material placed between a pair of electrodes. When an electric potential is applied between the electrodes, the electroluminescent material emits visible light. Typically, one electrode is transparent, allowing light to pass through and emit light.

  Reference is now made to FIG. Organic electroluminescent devices known in the art include an anode 401 on a substrate 403, a conductive polymer layer 405 adjacent to the anode, a hole transport layer 407 adjacent to the conductive polymer layer, and adjacent to the hole transport layer. An electron transport layer 409, and a cathode 411 adjacent to the electron transport layer. When power is applied, the anode is biased with respect to the cathode, and light is emitted at the contact surface 413 between the hole transport layer and the electron transport layer.

  FIG. 9 illustrates another exemplary electroluminescent device known in the art. For example, a square glass substrate 501 with a side of 15 mm is coated with a transparent anode 503. A square transparent hole transport layer 505 with a side of about 10 millimeters covers the anode, and the electron transport layer 507 covers the hole transport layer and forms a contact surface 509 between the two layers. The cathode 511 covers the electron transport layer. In some devices, the hole transport layer consists of two layers of slightly different composition, one layer forming a lower region 513 adjacent to the anode and the other layer being an upper region 515 adjacent to the electron transport layer. Form. The thickness of the anode, hole transport layer, electron transport layer, and cathode are each about 10-500 nanometers (100-5000 Angstroms).

  In operation, power from voltage source 517 is applied to the cathode and anode, biasing the anode positively with respect to the cathode. This is due to the movement of positively charged ("hole") regions from the anode through the hole transport layer to the electron transport layer and from the cathode through the electron transport layer to the hole transport layer. Cause movement. Holes and electrons combine at the contact surface 509 between the two layers to emit visible light. Light propagates out of the device through the hole transport layer, anode and substrate, as indicated by arrow 519.

  It would be a further advantage of the present invention to simplify the manufacture of organic light emitting devices and their complexity.

SUMMARY OF THE INVENTION The above problems are solved by a gas generation system that includes a gas generant composition that includes an extrudable polyvinyltetrazole fuel. Preferred oxidizing agents include non-metallic oxidizing agents such as phase stabilized ammonium nitrate. Other oxidizing agents include alkali metal and alkaline earth metal nitrates. The fuel is selected from the group of polyvinyltetrazoles and mixtures thereof. An exemplary group of fuels includes polymeric tetrazole with functional groups on the azole pendant. Preferred vinyl tetrazoles include 5-amino-1-vinyltetrazole and poly (5-vinyltetrazole), both of which exhibit self-propagating pyrolysis. Other fuels include poly (2-methyl-5-vinyl) tetrazole and poly (1-vinyl) tetrazole. These and other possible fuels are exemplified in their structure in the figures herein. Thus, depending on the design criteria of the gas generant composition, or depending on the starting reagent in the synthesis of the polyvinyl tetrazole, the polyvinyl tetrazole can exhibit pendant aromatic properties, or aromatic properties within the polymer backbone. In certain embodiments, the fuel comprises about 10-40% by weight of the gas generant composition.

  The oxidant is preferably selected from the group of non-metal and alkali metal, alkaline earth metal nitrates, or mixtures thereof. Non-metallic nitrates include ammonium nitrate and phase stabilized ammonium nitrate stabilized by known methods. Examples of alkali metal and alkaline earth metal nitrates include potassium nitrate and strontium nitrate. Other known oxidants that are useful as a gas generating composition for airbags are also contemplated. In certain embodiments, the oxidizer comprises about 60-90% by weight of the gas generant composition.

  Other gas generant components known for their utility in vehicle occupant protection systems and gas generant compositions typically contained therein are used in functionally effective amounts in the compositions of the present invention. Can be done. These include, but are not limited to, coolants, slag formers and ballistic modifiers known in the art.

  A zinc tetrazole organometallic complex in which a nitrile-containing prepolymer is first bound to the polymer by reacting the prepolymer with a divalent zinc halide under pressure and high temperature conditions in the presence of an azide and a surfactant. An aqueous process has been developed that converts to The resulting polymer intermediate can be filtered once, washed from the reaction media, and then converted to the corresponding tetrazole salt by treatment with concentrated acid. The polyvinyl (tetrazole) acid can then be converted to a water-soluble salt by reacting the acid with a suitable base.

  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. Articles formed from water-soluble salt coatings are also provided and are further described below. These and other advantages will be apparent from the detailed description.

Preferred Embodiments The present invention generally relates to a gas generant composition for an inflator of an occupant restraint system. In the present invention, the pyrotechnic composition uses poly (tetrazole) s or extrudable fuels, such as polyvinyltetrazole (PVT) s, for use in gas generation systems, such as high gas yields in vehicle occupant protection systems. Including for automotive airbag propellants. Poly (tetrazole) can be defined as any compound or molecule that contains one or more tetrazole rings. The fuel further functions as a binder. Preferred oxidizing agents include non-metallic oxidizing agents such as ammonium nitrate and ammonium perchlorate. Other oxidizing agents include alkali metal and alkaline earth metal nitrates.

  The fuel is selected from the group of poly (tetrazole) s or polyvinyltetrazoles and mixtures thereof. An exemplary group of fuels includes polymeric tetrazole with functional groups on the azole pendant. Vinyl tetrazoles include 5-amino-1-vinyltetrazole and poly (5-vinyltetrazole), both exhibiting self-propagating pyrolysis. Other fuels include poly (2-methyl-5-vinyl) tetrazole and poly (1-vinyl) tetrazole. Depending on the prepolymer selected for the reaction, these and other possible poly (tetrazole) salts / fuels are exemplified below, but not limited to, their structures.

  Additional benefits have been found for the fuel of the present invention. It is to avoid the difficult cold start ignition that requires a stronger ignition train and booster. For example, poly (5-amino-1-vinyl) tetrazole has no endothermic process before decomposition with exotherm begins. Thus, the heat consumption process that normally accompanies the combustion heat dissipation process, which serves as an energy barrier, is absent in the compositions of the present invention. Other polymeric azoles that function as fuels in the present invention are believed to have the same benefits. The polyvinyl azole fuel constitutes about 5-40% by weight of the gas generant composition.

  The oxidant is preferably selected from the group of non-metal and alkali metal and alkaline earth metal nitrates and mixtures thereof. Nonmetallic nitrates include phase stabilized ammonium nitrate stabilized by known techniques. Examples of alkali metal and alkaline earth metal nitrates include potassium nitrate and strontium nitrate. The composition comprising phase stabilized ammonium nitrate of the present invention is sufficient thermal in contrast to many other known compositions comprising unstabilized ammonium nitrate and / or phase stabilized ammonium nitrate. Shows stability. Other oxidants known to be useful as airbag gas products are also contemplated. However, in order to minimize the production of carbon monoxide and / or nitric oxide, it should be recognized that the oxidants of the present invention provide an overall oxygen balance within the combustion reaction. The oxygen balance provided in the present invention will be from -4.0% to + 4.0% when provided by the oxidant. For example, in black explosives, the amount of oxygen balance is deliberately given to produce carbon monoxide during the combustion of each black explosive, thereby providing the required pushing force with the lowest molecular weight gas. In some embodiments, the oxidant comprises about 60-95% by weight of the gas generant composition.

  Other gas generant components known for their usefulness in air bag gas generant compositions can be used 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 components of the present invention are supplied by suppliers known in the art and are preferably mixed by wet methods. Typical known suppliers include Aldrich or Fisher Chemical. The solvent chosen for the group substituted for the polymer fuel is at a temperature sufficient to dissolve the fuel but below the boiling point, for example, slightly below 100 ° C, but they are added and subsequently precipitated. Sometimes it is heated to a temperature low enough to prevent self-ignition of any component. Hydrophilic groups can be more efficiently dissolved, for example, by using water as a solvent. Other groups can be more efficiently dissolved in acidic solutions such as nitric acid. Other solvents include alcohols and plasticizers such as polyethylene glycol. Once a suitable solvent is selected and heated, the fuel is slowly added and dissolved. Thereafter, the oxidant is slowly added and dissolved. Other desirable ingredients are dissolved as well. The solution is heated and continuously stirred. After the solvent is turned off, the fuel and oxidant and other components are co-precipitated as a homogeneous solid solution. Once the solvent is at least substantially volatilized, more preferably after complete evaporation, the precipitate is recovered from the solvent. The composition can then be extruded into pellets or other useful shapes. More preferably, the gas generant composition of the present invention comprises polyvinyl (tetrazole) and phase stabilized ammonium nitrate. Its advantages are high gas yields and low solids production, high energy fuel / binders and inexpensive oxidants. Thereby, it is possible to avoid gas filtration required when solids are produced upon combustion. The compositions of the present invention can be extruded due to the flexible nature of the polymer fuel.

  The gas generant composition of the present invention can further include a second fuel formed from amine salts of tetrazoles and triazoles. These are described and illustrated in commonly owned US Pat. Nos. 5,872,329, 6,074,502, 6,210,505 and 6,306,232. These patents are referenced and incorporated as part of this specification. The total weight percent of the fuel components of both the first and second fuels or the composition of the present invention is about 5 to 40 weight percent of the total gas generant composition. As shown in the data shown in FIGS. 3 and 4, the use of a second fuel provides a burning rate that increases with increasing pressure.

More particularly, the nonmetallic salts of tetrazoles and triazoles include in particular the amine salts, amino salts and amide salts of tetrazoles and triazoles selected from the group comprising: 5,5′-bis Monoguanidinium salt of -1H-tetrazole (BHT · 1GAD), diguanidinium salt of 5,5′-bis-1H-tetrazole (BHT · 2GAD), monoaminoguanidinium of 5,5′-bis-1H-tetrazole Nium salt (BHT · 1AGAD), diaminoguanidinium salt of 5,5′-bis-1H-tetrazole (BHT · 2AGAD), monohydrazinium salt of 5,5′-bis-1H-tetrazole (BHT · 1HH) ), 5,5′-bis-1H-tetrazole dihydrazinium salt (BHT · 2HH), 5,5′-bis-1H - monoammonium salt (BHT _· 1NH 3) of tetrazole, 5,5'-bis -1H- diammonium salt of tetrazole (BHT _· 2NH 3), 5,5'- bis -1H- tetrazole mono-3-amino -1,2,4-triazolium salt (BHT · 1ATAZ), di-3-amino-1,2,4-triazolium salt of 5,5′-bis-1H-tetrazole (BHT · 2ATAZ), and 5,5 '-Azobis-1H-tetrazole diguanidinium salt (ABHT · 2GAD).

Examples of amine salts of triazoles include: mononitroammonium salt of 3-nitro-1,2,4-triazole (NTA · 1NH ₃ ), monoguanidinium of ₃ -nitro-1,2,4-triazole Salt (NTA · 1GAD), diammonium salt of dinitrobitriazole (DNBTR · 2NH ₃ ), diguanidinium salt of dinitrobitriazole (DNBTR · 2GAD), and monoammonium of 3,5-dinitro-1,2,4-triazole Salt (DNTR · 1NH3).

  Common non-metal salts of tetrazole as shown in Formula I include a cationic nitrogen-containing component Z and an anionic component comprising an R group substituted at the 5-position of the tetrazole ring and tetrazole ring. Common non-metallic salts of triazoles as shown in Formula II include a cationic nitrogen-containing component Z and an anion comprising a triazole ring and two R groups substituted at the 3- and 5-positions of the triazole ring. Contains sex ingredients. Here, R1 may or may not be structurally similar to R2. The R component is hydrogen or any nitrogen-containing compound such as amino, nitro, nitroamino or tetrazolyl or triazolyl, each directly substituted or substituted via an amine, diazo or triazo group from formula I or II, respectively. Selected from the group. Compound Z is substituted at the 1-position of each formula, and amines, aminos, amides including ammonia, carbohydrazide, oxamic hydrazide, and hydrazine; guanidine compounds such as guanidine, aminoguanidine, diaminoguanidine, triamino Guanidine, dicyandiamide, nitroguanidine; nitrogen-substituted carbonyl compounds or amides such as urea, oxamide, bis- (carbonamido) amine, azodicarbonamide, and hydrazodicarbonamide; aminoazoles such as 3-amino-1 , 2,4-triazole, 3-amino-5-nitro-1,2,4-triazole, 5-aminotetrazole, 3-nitroamino-1,2,4-triazole, and 5-nitroaminotetrazole and It is formed from the group comprising Min.

Example 1:
The reaction shown below illustrates the aqueous reaction and formation of the poly (tetrazole) of the present invention.

  As shown in the reaction, by reacting a prepolymer with a divalent zinc halide (chlorine, bromine or for example fluorine) in the presence of a surfactant and an azide under high pressure and pressure, the nitrile-containing prepolymer is It is first converted to a zinc tetrazole organometallic complex bound to a polymer. Zinc bromide, sodium azide and ammonium lauryl sulfate are used as zinc halide, azide salt and surfactant, respectively. The reaction time is about 170 ° C. for about 24 hours. The polymer intermediate was then filtered and rinsed to wash away the reaction medium. The washed polymer intermediate is then treated with a concentrated acid (eg, hydrochloric acid). The poly (tetrazole) acid is then treated with a base to convert the acid to a water soluble salt. All process steps are carried out in water as opposed to typical organic solvents often used. The percent yield of nitrile prepolymer converted to poly (tetrazole) is about 95%.

Example 2:
Poly (tetrazole) was formed in the same manner and molar ratio and reaction as given in Example 1. By reacting a divalent zinc halide with a prepolymer in the presence of a surfactant and an azide under high pressure and pressure, the nitrile-containing prepolymer is first converted to a zinc tetrazole organometallic complex bound to the polymer. . Zinc bromide, sodium azide and ammonium lauryl sulfate are used as zinc halide, azide salt and surfactant, respectively. The reaction time is about 16 hours at about 150 ° C. The polymer intermediate was then filtered and rinsed to wash away the reaction medium. The washed polymer intermediate is then treated with a concentrated acid (eg, hydrochloric acid). The poly (tetrazole) acid is then treated with a base to convert the acid to a water soluble salt. All process steps are carried out in water as opposed to typical organic solvents often used. The percent yield of nitrile prepolymer converted to poly (tetrazole) is about 90-95%.

Example 3:
Poly (tetrazole) was formed in the same manner and molar ratio and reaction as given in Example 1. By reacting a divalent zinc halide with a prepolymer in the presence of a surfactant and an azide under high pressure and pressure, the nitrile-containing prepolymer is first converted to a zinc tetrazole organometallic complex bound to the polymer. . Zinc bromide, sodium azide and ammonium lauryl sulfate are used as zinc halide, azide salt and surfactant, respectively. The reaction time is about 115 ° C. for about 16 hours. The polymer intermediate was then filtered and rinsed to wash away the reaction medium. The washed polymer intermediate is then treated with a concentrated acid (eg, hydrochloric acid). The poly (tetrazole) acid is then treated with a base to convert the acid to a water soluble salt. All process steps are carried out in water as opposed to typical organic solvents often used. The percent yield of nitrile prepolymer converted to poly (tetrazole) is about 70%.

Example 4-9:
Examples 4-9 are shown in the table below and show a comparison of the type and amount of gas produced for several known gas generant compositions and gas generant compositions made in accordance with the present invention. . Example 4 is a representative gas generant composition formed from 5-aminotetrazole and strontium nitrate, made by US Pat. No. 5,035,757, which is referenced and incorporated herein. . Example 5 is a tetrazole amine, such as the diammonium salt of 5,5′-bi-1H-tetrazole, made by US Pat. No. 6,210,505, which is hereby incorporated by reference. A typical gas generant composition formed from salt, strontium nitrate and clay. Example 6 is a tetrazole amine, such as the diammonium salt of 5,5′-bi-1H-tetrazole, made by US Pat. No. 5,872,329, which is incorporated by reference and incorporated herein. A representative gas generant composition formed from salt and phase stabilized ammonium nitrate. Example 7 is a representative gas generation formed from ammonium nitroamine tetrazole made according to US Pat. No. 5,872,329 and phase stabilized ammonium nitrate, which is referenced and incorporated herein. It is a composition. Example 8 is a representative formed from ammonium nitroamine tetrazole made according to US Pat. No. 5,872,329, phase-stabilized ammonium nitrate, and a slag former, referenced and incorporated herein by reference. Gas generating composition. Example 9 is a representative composition made in accordance with the present invention, comprising ammonium polyvinyltetrazole and phase stabilized ammonium nitrate (ammonium nitrate co-precipitated with 10% potassium nitrate).

Table 1 shows the relative amounts of carbon monoxide (CO), ammonia (NH 3), nitric oxide (NO), and nitrogen dioxide (NO ₂ ) produced (ppm) and gas generants produced in each example. The amount (g) of All examples were burned in a gas generator of substantially the same design.

  The data collected shows that the composition of Example 9 formed according to the present invention is well below the industry standard of 35 ppm and gives much less ammonia than the other examples. It has been found that the composition of the present invention provides a substantially lower amount of ammonia compared to other known gas generants. In some known gas generant compositions, it is often difficult to reduce the total amount of ammonia produced during combustion, while other performance criteria remain favorable.

Examples 10-14:
Theoretical Examples 10-14 are shown in the table below and provide a comparison for the different amounts and gas species produced for several gas generant compositions formed in accordance with the present invention. All of the phase-stabilized ammonium nitrate (PSAN 10) mentioned in Table 2 was stabilized by 10% by weight potassium nitrate of the total PSAN. In all examples, ammonium poly (C-vinyltetrazole) (APV) is used as the primary fuel. In one embodiment, a non-metallic diammonium salt of 5,5′-bis-1H-tetrazole (BHT.2NH ₃ ) is used as the second fuel. All the examples reflect the results obtained by burning the gas generant component (propellant composition) in an inflator of similar design or in an equivalent heat sink design gas generator.

  Example 10 was found to be only thermally stable with only a 0.5% mass loss at 107 ° C. for 400 hours. Thus, Example 10 incorporates a gas generant composition of the present invention, particularly a polyvinyltetrazole as defined herein, and phase stabilized ammonium nitrate (stabilized with 10% potassium nitrate). Illustrates unexpected thermal stability. It should be emphasized that other phase stabilizers known or recognized in the art are also contemplated.

  Examples 11-13 illustrate the use of a metal oxidant and polyvinyltetrazole. In some applications, the use of metal oxidants may be desired for optimization of flammability, burn rate index, gas generant burn rate and other design criteria. The examples illustrate that as more metal oxidant is used, the number of moles of gas produced upon combustion decreases.

  In contrast, Examples 10 and 14 illustrate that the number of moles of gaseous combustion products is maximized when non-metallic gas generant components are used. Accordingly, preferred gas generant compositions of the present invention comprise at least one polyvinyl (tetrazole) as a fuel component and one non-metallic oxidant as an oxidant component.

Finally, with respect to Example 14, the addition of another non-metallic fuel (BHT.2NH ₃ ) to APV and PSAN 10 increases the gas generant burn rate, thereby optimizing the combustion profile of the gas generant composition. It was found to be done. The burn rate in Example 14 is recorded at 1.2 inches per second at 5500 psi. The addition of non-metallic amine salts of triazole and / or non-metallic amine salts of tetrazole as described in US Pat. No. 5,872,329 may be advantageous with respect to combustion rate and gas production. Furthermore, the flexible nature of APV provides extrudability to the propellant composition. As shown in FIGS. 3 and 4, the addition of the second fuel provides a burning rate that increases with increasing combustion pressure. FIG. 3 illustrates the burn rate versus pressure for a formulation containing only polyvinyltetrazole and phase stabilized ammonium nitrate. In contrast, FIG. 4 shows pressure-combustion of a composition similar to FIG. 3 comprising polyvinyltetrazole and phase-stabilized ammonium nitrate with the addition of di-ammonium BHT in the weight percent range shown herein. Illustrate speed. It can be concluded that the addition of the second fuel described herein provides an important advantage with respect to the burning rate. The practical effect is improved performance reproducibility and improved ballistic properties of the gas generant formed.

Examples 15 and 16:
Examples 15 and 16 illustrate the cold start effect of a gas generant composition comprising polyvinyltetrazole. As shown by differential scanning calorimetry (DSC), typical smokeless or non-metallic compositions may show a tendency to endotherm prior to combustion with exotherm. As a result, a relatively larger amount of energy must be utilized to ignite the gas generant and maintain its combustion. Often, a more aggressive ignition train, possibly including a more aggressive booster composition, is required to reach the energy level necessary to ignite the gas generant and maintain combustion. Example 15 includes 65% PSAN10 and about 35% BHT. It relates to a composition comprising a 2NH _3. As shown by the DSC test, the endotherm is maximized at 253.12 degrees Celsius, which records a loss of about 508.30 joules per gram of gas generant. In comparison, Example 16 relates to a composition comprising about 15% poly (C-vinyltetrazole) and about 85% PSAN10. Unexpectedly, there is no endothermic process as demonstrated by DSC. Accordingly, combustion proceeds in a manner that is not prohibited. As a result, less energy is required to burn the gas generant composition, thereby reducing ignition train or ignition and booster requirements.

Example 17:
Another advantage of the present invention is illustrated in FIGS. FIG. 5 illustrates the baseline or pre-aging combustion of a gas generant composition made in accordance with the present invention in a state of the art gas generator. Specifically, the gas generant composition contained 80.6% PSAN, 8.0% PVT and 11.4% BHT-2NH3. On the other hand, FIG. 6 illustrates the combustion after aging of the same gas generant composition in the same gas generator. The curves shown in FIGS. 5 and 6 are “high temperature” or + 85 ° C., “ambient temperature” or 23 ° C., and “low temperature” or −40 ° C. for a standard driver-side inflator in a 60 liter ballistic tank. Related to deployment in Japan. As shown, there is only a slight combustion profile difference between pre-aging and post-aging operations when deployed at three different temperatures. It will be appreciated that the USCAR specification for “accelerated aging” is 107 ° C. 400 hours. Many automakers around the world typically require similar accelerated aging standards.

Example 18-21:
Examples 18-21 further illustrate how the selection of a prepolymer containing cyano or nitrile groups is a determinant of the final product in the present invention. Thus, it can be seen that a proper choice of prepolymer containing nitrile groups will produce the desired poly (tetrazole) as the final product.

Example 18:

Example 19:

Example 20:

Example 21:

  In different aspects of the present invention, it has been unexpectedly discovered that polyvinyltetrazole salts formed as described in the present invention provide salts with luminescent properties. Unlike similar salts formed using organic solvents, the salts of the present invention provide luminescent properties not previously shown. It will be appreciated that the polyvinyltetrazole salts formed by the aqueous method of the present invention impart luminescent quality to the resulting salts. Thus, the characteristics of salts can be distinguished from salts formed with organic solvents.

  Accordingly, articles formed from the salts obtained from the manufacturing method of the present invention include glasses, polymers, or other substrates where luminescent quality is desired. Salt deposition can be provided, for example, by spin casting salts suspended in an aqueous solution onto an indium-tin oxide (ITO) anode coating on a glass substrate. US Pat. No. 5,719,467, referenced and incorporated as part of this specification, describes the spincast deposition of polyaniline on an ITO anode and thereby the production of an organic light emitting device. It is contemplated to replace polyaniline with the salts of the present invention to provide an alternative method for providing organic light emitting devices. The use of the polyvinyl salts of the present invention removes additional layers such as the anode, conducting polymer, hole transport, electron transport and cathode layers that are required when luminescent quality is desired. Other uses are also contemplated. A schematic diagram of an organic electroluminescent article formed by a known spin coating technique (described below) and a known deposition process is shown in FIGS. In contrast, a substrate containing only the salts of the present invention is shown in FIG. 7, which provides luminescent quality. For example, the advantages of simplifying the manufacturing process due to the removal of the layers required when using organic electroluminescence technology are obvious. In addition, no power source is available that is known to be used in other prior art structures to maintain emission quality, as shown, for example, in FIG.

  Spin coating techniques and equipment are illustrated and known in U.S. Pat. Nos. 4,519,971, 4,517,140, 3,695,911, 4,637,791, 4,659,522 and 4,637,791. . These patents are referenced and incorporated as part of this specification.

  As shown in FIG. 7, a coating 300 formed in accordance with the present invention is deposited on a substrate 302 such as glass. The solution provided in step 4 of the manufacturing method, or the salt suspended in the aqueous solution, is spin cast onto a glass substrate and essentially air dried. For example, the type of cation salt resulting from the chosen base will be a critical factor in the luminescence or fluorescence quality of the salt. It will be appreciated that various reaction conditions or reactants can be varied to determine the luminescence intensity of the resulting salt. Microscope slides, eyepieces or other glassware are illustrated but do not limit the scope of use of luminescent salts in any way. It will be appreciated that other layers typically utilized to illuminate the substrate 302 platform are not required for emission quality, but they can be provided if desired.

  In different aspects of the invention, the compositions of the invention can be used in gas generation systems. For example, as schematically shown in FIG. 2, a vehicle occupant protection system made in a known manner is a collision that is electrically connected to an airbag inflator and further a seat belt assembly in the steering wheel. Includes sensors. The gas generant composition of the present invention can be used in subassemblies within both a more extensive vehicle occupant protection system or gas generator system. More particularly, each gas generating device used in an automobile gas generating system can include a gas generating composition as described herein.

  The composition can be dry or wet mixed using methods known in the art. The various components are generally provided in the form of particulates and are mixed with other gas generant components to form a uniform mixture. The mixture is then pelletized or formed into other useful shapes by safe methods known in the art. A preferred gas generant composition comprises 60-95 wt% phase stabilized ammonium nitrate (10-15% KNO3) and 5-40 wt% non-metallic poly (c-vinyltetrazole). A preferred gas generant composition comprises 85 wt% phase stabilized ammonium nitrate and 15 wt% ammonium poly (c-vinyltetrazole). A more preferred gas generant composition is about 8 wt% ammonium poly (c-vinyltetrazole), about 11 wt% diammonium salt of 5,5′-bis-1H-tetrazole, and about 81 wt% phase stabilization. Containing ammonium nitrate.

  It should be noted that all percentages given here are weight percentages based on the total weight of the gas generant composition. The chemicals described herein can be supplied by companies such as Aldrich Chemical Company and Polyscience Company.

  As shown in FIG. 1, an exemplary inflator incorporates a double chamber design to adjust the accompanying airbag deployment force. In general, an inflator comprising a main gas generant composition 12 and an autoignition / booster composition 14 and formed as described herein can be manufactured by methods known in the art. US Pat. Nos. 6,422,601, 6,805,377, 6,659,500, 6,749,219 and 6,752,421 illustrate typical airbag inflator designs, and these patents are Referenced and incorporated herein by reference.

Please refer to FIG.
The exemplary inflator 10 described above can be incorporated into the airbag system 200. The airbag system 200 includes at least one airbag 202 and an inflator 10 that includes the gas generant composition 12 of the present invention, the inflator being associated with the airbag 202 in fluid communication with the interior of the airbag. The airbag system 200 includes or is connected to a crash sensor 210. The crash sensor 210 includes a known crash sensor algorithm and signals activation of the airbag system 200 in the event of a crash, for example by activation of the airbag inflator 10.

  Please refer to FIG. The airbag system 200 can be incorporated into a wider and more comprehensive vehicle occupant restraint system 180 that includes additional elements such as a safety belt assembly 150. 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 154 (eg, a spring-type mechanism) can be coupled to the end portion of the belt. In addition, a safety belt pretensioner 156 that includes the propellant 12 and the autoignition composition 14 can be coupled to the belt retractor mechanism 154 to trigger the retractor mechanism in the event of a collision. Exemplary seat belt retractor mechanisms that can be used with the safety belt embodiment of the present invention are US Pat. Nos. 5,743,480, 5,553,803, 5,667,161, 5,451,008, 4,558,832 and 4,597,546. These patents are referenced and incorporated as part of this specification. Examples of typical pretensioners with which safety belt embodiments of the present invention can be combined are disclosed in US Pat. Nos. 6,505,790 and 6,419,177. These patents are referenced and incorporated as part of this specification.

  The safety belt assembly 150 includes a crash sensor algorithm 158 (e.g., a known crash sensor algorithm that generates an activation signal for the belt pretensioner 156, e.g., upon activation of a pyrotechnic igniter (not shown) incorporated in the pretensioner. Inertial sensors or accelerometers) or can be connected thereto. US Pat. Nos. 6,505,790 and 6,419,177, referenced above and incorporated as part of this specification, provide examples of pretensioners that start in such a manner.

  Although the safety belt assembly 150, the airbag system 200, and the wider vehicle occupant protection system 180 are illustrated, the gas generation system contemplated by the present invention is not limited thereto.

Method of Manufacture As illustrated in Examples 1-3 and further illustrated in Examples 18-21, the fuel of the present invention can be formed by an aqueous method of synthesizing polyvinyltetrazole as described below. it can. The aqueous process includes the following steps. First, prepolymers containing pendant nitrile or cyano groups are provided. Any prepolymer within the cyano or nitrile functionality can be used in the synthesis. Examples include poly (cyanoacrylates), poly (haloacrylonitriles) where the halogen can be fluorine, chlorine, bromine or iodine, poly (crotononitrile), poly (triallyl cyanurate), cellulose cyanoethyl ether and poly (Methacrylonitrile). Certain copolymers or block copolymers having nitrile functionality are also contemplated for use as prepolymers. These copolymers include poly (butadiene / acrylonitrile) s and poly (styrene / acrylonitrile) s, and other polymer blends of any nitrile-containing polymer or oligomer. These polymers and copolymers can be purchased from known manufacturers such as, for example, Polysciences (www.polysciences.com).
Although any useful backbone chain can be used, the preferred polymer backbone chain is a polyethylene chain. Nitriles cannot be part of the backbone and must always be pendant groups. In addition, the materials can be classified as pendant nitrile-containing prepolymers. The prepolymer can exhibit aromatic properties.

The prepolymer is then reacted with divalent zinc halide (ZnX ₂ ) in the presence of an azide such as sodium azide, water and a surfactant under high temperature pressure to form a zinc tetrazole organometallic bonded to the polymer. Form a complex. The polymer intermediate complex is then filtered, washed out of the reaction medium, treated with concentrated acid and converted to the corresponding tetrazoleic acid. The poly (tetrazole) acid can then be converted to a water-soluble salt by reacting with a suitable base. All process steps are carried out in water.

  The azide can be any metal azide such as sodium azide. The surfactant can be essentially any useful surfactant. One exemplary surfactant is ammonium lauryl sulfate provided by Rhodia. Other surfactants include various soaps or detergents (eg, Dial®), phase transfer catalysts such as quaternary ammonium salts (eg, tetrabutylammonium bromide from Aldrich Chemical Company). . The zinc halide can be zinc chloride, zinc bromide or zinc iodide. The concentrated acid can be an organic acid such as hydrogen chloride, hydrogen bromide, nitric acid, sulfuric acid, and acetic acid. Preferably, any acid that provides a polymer suspension solution having a pH of about 1-3 can be used. For example, these acids are available from Aldrich Chemical Company. The base or bases used can be selected from the group comprising ammonium hydroxide, hydroxylamine, hydrazine and any suitable amine having a suitable pKb to form a stable salt with the polymer. . For example, these bases are available from Aldrich Chemical Company.

  The process conditions can be described as follows: 1.0 molar equivalent of polyacrylonitrile (an exemplary prepolymer, Polysciences), 0.5 molar equivalent of zinc bromide dihydrate (Aldrich) , 1.1 molar equivalents of sodium azide (Aldrich), and 0.0025 molar equivalents of ammonium lauryl sulfate (Rhodia) as a 28 wt% aqueous solution. The final molar amount based on the amount of polymer in water is about 1.0. An exemplary batch used 47.7 grams of prepolymer, 64.29 grams of azide, 117.41 grams of zinc, and 2.25 ml of surfactant and all ingredients were mixed in 900 ml of water. . The ratio can vary as long as an excess of azide is present and at least 0.5 equivalents of zinc are present. The amount of surfactant can also vary from 0.1 equivalents or less to 0.000001 equivalents or more. The amount of water can vary from a 5.0 molar solution to a 0.1 molar solution. Reagents are mixed in a pressure reactor and the order of addition of reagents to the pressure reactor can be varied. When all the reagents are added, the pressure reactor is sealed. The contents are stirred and heated to 170 ° C. to reach a pressure of between 80-100 psi. The mixture is then reacted for about 24-48 hours (preferably 24 hours) and then cooled to room temperature. The milky contents are then preferably filtered with a Buchner funnel and washed with an equal volume of water.

  The contents are then dispersed in about 1.0 to 10.0 liters, preferably 3.0 liters of cold water (range 0-24 ° C.) and stirred rapidly. Sufficient acid is added to adjust the suspension to a pH in the range of 1-3 and the mixture is continuously stirred for about 20 minutes. The suspension is then filtered again with a Buchner funnel using a nylon screen and washed with an equal volume of water. This leaves a rubbery, moist substance in the Buchner funnel. Take it out and cut it into small pieces using standard scissors. This material is then suspended in 1.0 liter of water and excess ammonium hydroxide (Aldrich) is added while stirring the suspension. Ammonium hydroxide is used in at least 1 molar equivalent, and more if desired.

  The suspension is slowly dissolved. However, it can be heated to accelerate the process. The temperature can range from about 25-100 ° C. The mixture is dissolved and becomes very viscous and stirring is stopped. The solution is then poured onto a flat metal sheet and air dried to remove any excess ammonia. The material is then further dried into a thin film in an oven and then powdered by a ball mill. In essence, after the addition of ammonium hydroxide, the product is completely reacted. Also, the other subsequent steps are simply drying and processing the material.

In general, as explained in detail above, the method of forming poly (tetrazole) includes the following steps:
1. Providing a reaction vessel;
2. Adding water, at least one azide salt, at least one surfactant, at least one divalent zinc halide and at least one polymer containing cyano or nitrile functional groups to the reaction vessel, wherein water, azide salt The order in which the surfactant, divalent zinc halide and polymer are added to the reaction vessel can be varied;
3. Mixing the contents of the reaction vessel into a liquid mixture and reacting the mixture;
4). Washing and filtering the contents of the reaction vessel to prepare a filtrate / water mixture;
5). Acidifying the filtrate / water mixture to a pH of about 1-3 and stirring it to form a solid in solution;
6). Filtering the acidified filtrate / water mixture to separate the solid from the acidified filtrate / water mixture;
7). Suspending a solid in water and adding an excess of a base such as ammonium hydroxide to the suspension while stirring;
8). 8. dissolving the solid in the base / water mixture to form a slurry; and The process of pouring the slurry into a container and drying the slurry to form the final solid.

  The use of an aqueous system eliminates the need for expensive, potentially toxic and / or flammable organic solvents. This increases safety while at the same time reducing the overall cost dramatically. The intermediate zinc complex is easily filtered from the reaction media, easily converted to the corresponding acid, and then easily further converted to a water-soluble polyelectrolyte salt.

  The description of the present invention is for illustrative purposes only and should not be construed as limiting the scope of the invention in any way. Accordingly, one of ordinary skill in the art appreciates that various modifications can be made to the embodiments disclosed herein without departing from the scope of the invention as defined in the claims.

FIG. 1 is a cross-sectional view showing the general structure of the inflator of the present invention; FIG. 2 is a schematic diagram of an exemplary vehicle occupant restraint system that includes the gas generant composition of the present invention. FIG. 3 is a graphical representation of each burning rate versus the burning pressure of the gas generant composition. FIG. 4 is a graphical representation of the respective combustion rates versus the combustion pressure of the gas generant composition. FIG. 5 is a graphical representation showing the combustion profile of the same gas generant before and after aging at 107 ° C. for 400 hours. FIG. 6 is a graphical representation showing the combustion profile of the same gas generant before and after aging at 107 ° C. for 400 hours. FIG. 7 is a schematic diagram of an article comprising a layer of polyvinyl salt formed according to the aqueous method of the present invention. FIG. 8 represents a prior art LED and LCD article. FIG. 9 represents a prior art LED and LCD article.

Claims (10)

A method of forming a polyvinyl (tetrazole) salt comprising the following steps:
Providing a reaction vessel;
Adding water to the reaction vessel;
Adding at least one azide salt to the reaction vessel;
Adding at least one surfactant to the reaction vessel;
Adding at least one divalent zinc halide to the reaction vessel;
Adding at least one polymer containing cyano or nitrile functionality to the reaction vessel, wherein the order of adding water, azide salt, surfactant and polymer to the reaction vessel can be varied;
Mixing the contents of the reaction vessel into a liquid mixture;
Heating the contents of the reaction vessel and reacting the contents of the reaction vessel;
Cooling the contents of the reaction vessel;
Filtering the contents of the reaction vessel to produce a filtrate;
Washing the filtrate with water to produce a filtrate / water mixture;
Dispersing the filtrate / water mixture in about 1.0-10 liters of cold water and stirring it;
Acidifying the dispersed filtrate / water mixture to a pH of about 1-3 and stirring it;
Filtering the acidified filtrate / water mixture and separating the solid from the acidified filtrate / water mixture;
Washing the solid;
Suspending the solid in water and adding excess ammonium hydroxide to the suspension with stirring;
Dissolving a solid in an ammonium hydroxide mixture to form a slurry; and pouring the slurry into a container and drying the slurry to form a final solid. An article comprising the product of the method of claim 1. Providing a reaction vessel;
Adding water, at least one azide salt, at least one surfactant, at least one divalent zinc halide, at least one polymer containing cyano or nitrile functionality to the reaction vessel, wherein the reactants The order of adding water, azide salt, surfactant and polymer to the container can be varied;
Mixing the contents of the reaction vessel into a liquid mixture;
Washing and filtering the contents of the reaction vessel to produce a filtrate / water mixture;
Acidifying the filtrate / water mixture to a pH of about 1-3, stirring it to produce a solid in solution;
Suspending the solid in water and adding excess base to the suspension with stirring;
Dissolving a solid in a base / water mixture to form a slurry; and pouring the slurry into a container and drying the slurry to form a final solid;
A luminescent composition formed from a process for producing poly (tetrazole) comprising: An article comprising the luminescent composition according to claim 3. A gas generator comprising the product of the method of claim 3. A substrate comprising a coating formed from the product of the method of claim 1. A substrate comprising a coating formed from the luminescent composition of claim 3. Providing a reaction vessel;
Adding water, at least one azide salt, at least one surfactant, at least one divalent zinc halide, at least one polymer containing cyano or nitrile functionality to the reaction vessel, wherein the reactants The order of adding water, azide salt, surfactant and polymer to the container can be varied;
Mixing the contents of the reaction vessel into a liquid mixture;
Washing and filtering the contents of the reaction vessel to produce a filtrate / water mixture;
Acidifying the filtrate / water mixture to a pH of about 1-3 and stirring it;
Filtering the acidified filtrate / water mixture and separating the solid from the acidified filtrate / water mixture;
Suspending the solid in water and adding excess base to the suspension with stirring;
Dissolving a solid in a base / water mixture to form a slurry; and pouring the slurry into a container and drying the slurry to form a final solid;
A process for producing a vinylated tetrazole substituted at the 5-position. An article comprising a product formed from the method of claim 8. A substrate comprising a coating formed from the product of the method of claim 8.

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