KR19980701746A - Process for preparing gas generating composition - Google Patents

Abstract

A novel method of treating a gas generating composition to provide a feed-stock is described. The method of the present invention involves using a sufficient amount of binder and other additives in the mixture of gas generating composition constituents to mass the constituents of the gas generating material to form granules in which the constituents are mixed. The method includes roll coating, continuous mixing, static mixing, lyophilization, solvent extraction, emulsification, azeotropic distillation, spray drying, fluidized bed treatment and particle grinding, which are used to prepare feed-stock for the final gas product. Used. The method of the present invention can be used to treat gaseous materials, in particular with non-azido fuels.

Description

Process for preparing gas generating composition

Gas generating chemical compositions are useful in a variety of different applications. Such compositions are of critical use in the operation of inflatable vehicle safety restriction systems, commonly called air bags. Response to airbags has increased, and many, if not most, new vehicles are equipped with such a device. In fact, many new cars are equipped with multiple airbags to protect drivers and passengers.

In the field of automotive airbags, enough gas must be produced to inflate the device in an instant. Between the time the car crashes into an accident and the moment the driver is pushed onto the steering wheel or dashboard, the airbag must fully inflate. As a result, almost instantaneous gas production is required.

In addition, there are many important design criteria that must be met. Set standards required for automakers and others to meet their specifications. It is extremely difficult to prepare gas generating compositions to meet these important criteria. These details require the gas generating composition to produce gas at the desired rate. In addition, the details severely limit the production of toxic or harmful gases or solids. Examples of restricted gases include carbon monoxide, carbon dioxide, NOx, SOx and hydrogen sulfide.

Automakers also produce gas at a sufficiently low and quite low temperature, specifically suggesting that the person in the car will not burn in the impact of an inflating airbag. If the gas produced is too hot, there is a possibility that a person in a car will burn and hit an airbag that has just been deployed. Thus, the combination of gaseous products and airbag structures needs to isolate the person in the vehicle from excess heat. All of this is required while the gaseous product maintains a suitable burn rate. Industrially, a burn rate in excess of 0.5 inches (ips) per second at 1,000 psi is desired, preferably in the range of 1.0 ips to about 1.2 ips, preferably at 1,000 psi.

In another important design criterion involved, the amount of particulate matter produced in the gas generating composition is limited. Particulate matter may interfere with the operation of further restriction systems and may constitute hazardous solid waste that must be handled after impede breathing, irritate skin and eyes, or operate safety devices. The latter is undesirable in terms of current sodium azide materials, but is one that should be allowed because there is no acceptable colorant.

In any case, in addition to limiting the amount of particles produced, it is desirable that the size of these particles be more than readily filtration. For example, the composition preferably produces a filterable solid slack. When the solid reaction product forms a stable substance, the solid can be filtered to prevent it from being discharged to the surrounding environment. It also limits interference with the gas generating device and potentially harmful dust spreads around the used airbags, limiting irritation to the lungs, mucous membranes and eyes of the person or rescuer in the vehicle.

In addition, both organic and inorganic materials have been proposed as possible gas generating agents. Such gaseous compositions include oxidants and fuels that react sufficiently sufficiently to produce large amounts of gas in an instant.

Currently, sodium azide is the most widely used and accepted as a gas generating material. Sodium azide meets nominal industrial details and guidelines. Nevertheless, sodium azide has many constant problems. Sodium azide is relatively toxic as a starting material and the toxicity level measured by oral rat LD ₅₀ is in the range of 45 mg / kg. Workers who regularly handle sodium azide have experienced various health problems such as severe headaches, shortness of breath, cramps and other symptoms.

In addition, sodium azide is generally toxic to sodium azide combustion products because molybdenum disulfide and sulfur are used as oxidants. When reacted, these materials produce toxic hydrogen sulfide gas, caustic sodium oxide and sodium hydroxide powder. Rescue workers and motorists were dissatisfied with both the hydrogen sulfide gas and the corrosive powders produced by the action of sodium azide-based gas generators.

It is also expected that there will be an increasing problem with discarding unused airbag systems in pet cars. Sodium azide remaining in this additional restriction system can flow out of the junk car and become water contaminants or toxic waste. In fact, it has been reported that sodium azide contacts explosive battery acid after disposal to form explosive heavy metal azide or hydrazoic acid.

In order to overcome the disadvantages of using azide based fuels as gas generating compositions, many new compositions have recently been developed. Such compositions are herein incorporated by reference and described and claimed in US Patent Application Serial No. 08 / 101,396, filed pending on August 2, 1993, entitled Bitetrazolamine Gas Generating Composition and Method of Use. As described in this patent application, as a preferred oxidant, bitetrazolamine (BTA) having copper oxide, or a salt or a complex thereof, is used as the fuel. The composition may comprise about 15 to about 35 weight percent fuel and about 60 to about 85 weight percent oxidant.

Other recently developed gas generating compositions are referenced herein and are described and claimed in US Patent Application Serial No. 08 / 103,768, filed on the August 10, 1993, pending application, thermite composition for gas generating agents. .

Many of these new compositions can be easily processed on a laboratory scale, but such treatment techniques are not suitable for real scale treatment. Mass treatment of gaseous products is generally carried out in two ways. The feed-stock is initially prepared from obtaining the final gaseous product. The final material is usually produced through processing or injection molding. Recently, the most widespread final product is a compressed tablet of about 0.25 inches in diameter. In the case of automotive airbags, many of these tablets (sometimes called pellets or fills) can be used to produce a sufficient amount of gas to inflate the gasbag.

Pellets are generally produced by placing an amount of feed-stock in a pellet press. The feed-stock is then physically pressed into a mold in the form of a desired pellet. After pressing, the pellet can be separated from the mold.

In order to produce gas-generating pellets effectively, the feed-stock must have mass flow properties that can easily flow from the pellet press supply bin into the mold. In addition, after the pressurization is completed, the feedstock must be effectively separated from the mold. The produced pellets also have a significant breaking strength, so that if left on the wheel for more than a few years, it must not break or erode under force.

Non-azide-based gas generating compositions that are substantially superior to azide-based compositions in terms of ballistics and stability cannot be effectively used unless they are effectively treated. One problem facing some new compositions is that the compositions must be effective at the macromolecular level. In contrast, in typical azide-based compositions, small flocculation of pure sodium azide free of oxidant may be allowed. Because the composition tolerance is so generous, it is not necessary to treat such azide based compositions to ensure that the granules of each sodium azide are physically attached to the oxidant.

Many new product compositions, which are well practiced, however, appear to require strict compositional balance at the macromolecular level. However, without significant modification of the process, many known treatment techniques for azide-based compositions cannot effectively treat new non-azide-based compositions.

From the foregoing, there is provided a method of treating a gas generating composition to provide a feed-stock capable of forming a gas producing tablet that is economically and effectively compressed, easily separated from the mold, and has sufficient fracture strength to meet industry standards. It will be appreciated that advances have been made in the art.

In fact, it is an additional advance in the art to provide such a gas generating composition, in particular a new non-azide based composition method, which permits mass processing and thus achieves more accurate compositions.

Such methods are described and claimed herein.

The present invention relates to a process for preparing a feed-stock of a gas generating composition. In particular, the present invention relates to a process for preparing a non-azide based gas generating composition into a form that can be processed by compression, injection molding or otherwise to form a final form.

BRIEF DESCRIPTION OF THE DRAWINGS In order to understand the object of the present invention and how to achieve the above and other advantages, the present invention described above briefly will be described in detail with reference to the accompanying drawings. These drawings are only intended to provide information about exemplary embodiments of the present invention, but should not be construed as limiting the scope of the present invention. The drawings will be used to describe and describe the present invention in more detail.

1 is a schematic diagram of a roll coating process in accordance with the teachings of the present invention.

2 is a schematic diagram of a continuous process according to the present invention.

3 is a process schematic of the present invention using a fixed mixer.

4 is a process schematic of the present invention including sublimation.

5 is a schematic diagram of a solvent extraction process of the present invention using a dropping column.

6 is a process schematic of the present invention including emulsification.

7 is a process schematic of the present invention including a fluidized bed.

The present invention relates to a novel process for producing a gas generating feedstock. According to one method of the present invention, such as a composition comprising a fuel comprising biterrazolamine and an oxidant comprising copper oxide, the gas generating feedstock is initially composed of a gas generating material having a non-azide based fuel. According to the required amount to prepare a component weighed in a predetermined ratio to prepare. The components were then mixed together in a carrier solvent such as water to increase the contact surface between the components. The carrier solvent was added atomized with fog, and fog was introduced into the components.

The binder (preferably soluble in the carrier solvent) is included in the mixture in an amount sufficient to cause the components of the gas generating material to agglomerate and form granules when the components are mixed. After the components have been sufficiently aggregated, the components are dried to remove the carrier carrier.

The binder preferably has one or more groups having a melting point of about 200 ° C. to about 500 ° C. and comprising nitrate, nitrogen and oxygen in an amount sufficient to balance the mixture of gas generating components. The binder can also be dried anhydrous.

Binders include nitrates, sugars, argars, gums, coupling agents, monomers and polymers having a solubility of at least about 2% in carrier solvents, saponified waxes and oils, siloxanes, carbonates, resin salts , Stable oxides and silicates.

The binder is added to make up about 0.01% to about 2.5% by weight of the feedstock, and preferably comprises only about 0.01% to about 1.5% by weight of the feedstock produced.

According to another method of the present invention, a gas production feedstock is prepared by preparing a required amount of constituent components weighed in a predetermined ratio according to the composition of the gas generating material having a non-azide fuel. The components were introduced into a rotary mixer and mixed to cause the components to aggregate in the mixer to form granules. The mixture can then be dried dry.

The mixer comprises a series of screens having a mesh size corresponding to the size of the desired granules. The screen is arranged so that aggregated granules that do not pass through the screen can be removed from the mixer.

According to another method of the present invention, a gas production feedstock is prepared by preparing a required amount of constituents weighed in a predetermined proportion according to the composition of the gas generating material having a non-azide fuel. The mixer includes a static housing in which the rotating blades inside are replaced. Water is added to the mixture and the blades are rotated so that the components aggregate in the mixer to form granules. Finally, the mixture is dried in anhydrous state under vacuum.

The mixture preferably contains the binder in an amount sufficient to cause the components of the gas generating material to agglomerate and form granules as the mixing blade rotates.

According to another method of the present invention, a required amount of constituents weighed at a predetermined ratio is prepared according to the composition of a gas generating substance having an oxidizing agent and a non-azide fuel, and the constituents are introduced into a static mixer so that the constituents aggregate in the mixer. To form granules.

In order to provide a fixed ambient when processing the components, the static mixer is preferably filled with an inert gas such as argon or nitrogen.

Static mixers are arranged with ramps of an angle that allow the components to pass through to induce greater cohesion between the fuel and the oxidant. In addition, a screen of a predetermined angle is provided in a predetermined mesh size to adjust the size of the aggregates removed from the mixer.

In another method of the present invention, a required amount of components measured at a predetermined ratio is prepared according to the composition of the gas generating substance, and the components are mixed with a carrier solvent such as water to dissolve one or more components in the solvent. do. It is also desirable to include the binder in the mixture.

The mixture was then subcooled under pressure in a non-contact heat exchanger to separate the components from the solution. The mixture was then frozen by introducing a refrigerant liquid, such as nitrogen, ammonia or carbon dioxide. The refrigerant liquid was then separated from ice and granules. Finally, heat was applied while adjusting the pressure to allow the frozen solvent to sublime.

Another method of the present invention involves initially preparing the required amount of components metered in proportions according to the composition of the gas generating material. This method is particularly useful for preparing feed-stocks of gaseous products comprising non-azide fuels. One or more constituents of the gaseous substance are mixed together in a first solution (preferably water) in which at least some of the constituents are dissolved.

Then, a second solution such as a polar solvent was mixed with the first solution. This is preferably carried out by introducing the first solution into the top of the dropping tower using the dropping tower filled with the second solution. The second solution may be mixed with the first solution, choosing to substantially dissolve any component of the gaseous product dissolved in the first solution. The aggregate of precipitated gaseous product is then removed from the mixture of the first and second solutions. The precipitate is then dried dry.

The binder is preferably included in an amount sufficient to cause the gas generating material to agglomerate and form granules when the aggregate is precipitated from the mixture of the first and second solutions.

Another method of the present invention comprises preparing a required amount of constituent components, metered in a predetermined proportion, depending on the composition of the gaseous product, preferably having a non-azide based fuel. The components were mixed together in a first solution (preferably water) such that at least one component was at least partially dissolved in the first solution.

Then, a second solution such as trichloroethane, tetrachloroethane or nonane was introduced into the mixture. The second solution is chosen not to mix with the first solution and to substantially dissolve any component of the gaseous product dissolved in the first solution.

The mixture is then physically emulsified and centrifuges or settling tanks are used to remove aggregates of gaseous material precipitated from the mixture. The binder is included in an amount sufficient to cause the components to aggregate and form granules when the mixture is emulsified.

According to another method of the present invention for producing a gas generating feedstock, preparing a required amount of the components quantified at a predetermined ratio according to the composition of the gas generating substance such as the gas generating substance containing the non-azide fuel Include. The components are mixed together in a first solvent such as water such that at least one of the components of the gas generating material is at least partially dissolved in the first solvent.

Then, a second solvent such as benzene, toluene, ethanol or propanol is introduced into the mixture. The second solvent may be mixed with the first solvent and is chosen to form an azeotrope with the first solvent.

The constituents of the gaseous product are then mixed with the first solvent and the second solvent and the solvent is azeotropically distilled. The binder is preferably included in the mixture in an amount sufficient to cause the components to aggregate and form granules when the components are mixed.

According to another method of the present invention, a gas production feed-stock is prepared by initially preparing the required amount of constituent components weighed in a predetermined proportion according to the composition of the gas generating material having the non-azide fuel. The components are mixed together in the first solution such that at least one of the constituents of the gaseous product is at least partially dissolved in the first solvent to form a mixture. The first solution may comprise water; Using a first solution that does not contain water reduces the final sensitivity of the mixture.

The mixture is then sprayed through the nozzle into an air stream or vacuum. The nozzles are arranged to separate the droplets into droplets that dry out to form aggregates as they move through the air stream. Aggregates are then collected and treated with the final product.

The binder is preferably included in the mixture in an amount sufficient to cause the components to agglomerate and form granules when the mixture is sprayed into the air stream.

Another method of the present invention involves preparing a required amount of components metered in a predetermined proportion depending on the composition of the gaseous product having the non-azide fuel. The constituents are preferably obtained in a dry state and, as such, are introduced at the inlet end of the fluidized bed. Inject the fluid medium through the fluidized bed to mix the components.

While mixing the constituents, a solvent such as water was introduced into the constituents at a temperature of about 60 to about 85 ° C. to allow the constituents to aggregate.

Then, after sufficient coagulation has taken place, the component is transferred to a dry zone from which the solvent is removed. Preheat the fluid medium and inject it into the fluidized bed in the drying zone to remove the solvent. When the fluid medium is injected into the drying zone, the pressure decreases to prevent the agglomerated granules from breaking.

According to another method of the present invention, a required amount of constituent components initially weighed in a predetermined proportion according to the composition of the gas generating material is prepared to obtain a gas generating feedstock. The constituents are then treated with a particle size reduction device that simultaneously grinds and mixes the materials. The binder may be included together and mixed with the components, after grinding, to aggregate the components. The binder may be added in the mixture in an amount sufficient to cause the components to aggregate to form granules.

Therefore, an object of the present invention is a method of treating a gas generating composition for economically and effectively producing a feed-raw material that can be easily separated from a mold and compressed into a gas producing tablet having a fracture strength sufficient to meet industry standards. Is to provide.

It is another object of the present invention to provide a process for treating such gas generating compositions, in particular new non-azide based compositions, which allows for mass processing to obtain more refined compositions at the macromolecular level.

Examination of the following description of the preferred embodiments and the accompanying drawings will make these or other objects and advantages of the present invention more apparent.

Detailed Description of the Preferred Embodiments

The present invention relates to a variety of feed-stock manufacturing methods from gas generating materials pressurized into pellets or injection moldable in useful form. Examples of gaseous materials that can be treated in accordance with the teachings of the present invention include compositions comprising non-azide fuels and oxidants. Some of the methods of the present invention are also useful for treating azide-based gas generating materials.

Use of binder

According to one method of the present invention, a gas production feedstock is prepared by first preparing the required amount of constituent components weighed in a predetermined proportion according to the composition of the gas generating material. The components of the gas generating material are mixed or otherwise treated to bring particle-particles into contact between the components. The binder is included in the mixture in an amount sufficient to agglomerate and form granules when the components of the gas generating material are mixed. At this time, the aggregate may be used as a feed fuel to be pressed into pellets, or injection molded to form pellets, or alternatively, may be formed in a preferred form.

Preferred gas generating compositions for use with the present method include compositions having components that do not aggregate in the surrounding environment. Many non-azide based compositions satisfy this condition. One such composition is the BTA / CuO composition described above.

According to this method, it is preferred to select a binder that is soluble under process conditions. Such effective materials are generally treated in the wet or slurried state, since their sensitivity is reduced in the presence of water.

In some processes, carrier solvents other than water may be used. In this process the binder must be selected in the carrier solvent. In other processes, the fuel and oxidant may be treated in a dry state. In this process, the binder should be selected to be soluble in its carrier solvent. After applying the dissolved binder, the mixture can be dried to remove the carrier solvent. If the binder flows under pressure to form a mechanical matrix, it may work effectively if not soluble.

Any material that can act as a tactifier is suitable as a binder. One of the main functions of the binder is to allow the fuel and oxidant to stick to each other for mechanical bonding. When bonded, two or more components that produce a tactile may be used to allow mechanical bonding.

The binder may select what is consumed during the combustion of the gas generating material. Such binders preferably have a low melting point. Alternatively, it is also possible to use binders which are not consumed but remain as metal or ceramic slags after combustion of the product. It is believed that some of these two types of binders may be used in combination, while some are consumed and others form slack. In most gas generating compositions, the melting point of the binder should be about 200 to 500 degrees Celsius.

It is presently preferred that the binder be selected with a relatively high crystal strength. By selecting a binder with higher fracture strength than the lowest fracture strength of any other constituent in the gas generating material, the binder is prevented from weakly binding in the final product.

It may be advantageous to select a binder comprising nitrogen, nitrates and / or oxygen to balance the mixture.

Preferably, the binder can be dried and made anhydrous with any additives to the gas generating components. Many of the recently developed fuels for gas generating compositions are water disinfectants. Thus, if the binder cannot be dried anhydrous, there is a risk that any water remaining in the composition will have an adverse effect on the combustion rate of the composition.

When attempting to use an organic binder in a composition entering an air bag, care should be taken to ensure that the carbon monoxide produced during combustion is within acceptable levels.

Examples of suitable binders include organic and inorganic nitrate materials such as 3,5 dinitrotoluene, isopropyl nitrate, potassium nitrate, sodium nitrate or lithium nitrate. Other acceptable binders include sugars such as glucose, dextrose or fructose; Agar such as agar or gelatin; And gums such as xythium gums, gum gums or synthetic gums (latex). Additional binders include coupling agents such as organo-titanate, organo-zirconate, organo-aluminates and organo-silicates; Monomers and polymers having a solubility of at least about 2 percent in carrier solvents such as polyvinyl alcohol, polyvinyl acetate, latex, organic polymers, nitride polymers, or azide monomers and polymers; Saponified waxes and oils such as soaps; And siloxanes such as silicone oils and organo-silicon liquids. In addition, other organic and inorganic fillers that act as binders will also be suitable. These include carbonates such as calcium carbonate, sodium carbonate, sodium bicarbonate and aluminum carbonate; Resinates of carboxylic acids (stearate, palmate, linoleate and the like); And other silicates.

In some cases of application, it may be desirable to select a binder that acts as a burn rate catalyst for the gas generating material. Such binders may include carbonates, resinates, carboxylates, stable oxides, nitrates and silicates.

The binder may be added to constitute about 0.01 to about 2.5 weight percent, preferably from about 0.01 to about 1.5 weight percent. Care must be taken not to add amounts that are undesirable and disadvantageous to the ballistic properties of the gas generating material.

Various methods can be used to add the binder to the mixture. The binder may be included in the mixture by simply introducing the binder when the gas generating constituents are mixed. Alternatively, one or more of the components and the binder may be mixed before all of the components are mixed together.

Currently, one of the preferred methods of introducing the binder is to introduce the binder into the mixture in atomized, i.e., misted and atomized form, to facilitate the dispersion of the binder in the mixture and to ensure that the aggregation of the mixture is at an appropriate level. Minimize the amount.

Flow agents and process lubricants

According to one method of the invention, the flow agent or treatment lubricant may be added to the gas generating constituent at some point during the processing of the feed-stock. Treatment of the mixture with a flow agent will facilitate the flow of the mixture from the bin into the pellet press. Alternatively, flow or treatment lubricants can be used to lubricate the components so that certain products have a large bulk density. When the gaseous feed fuel is fed to a pellet press to produce gaseous pellets, the material must be cleanly separated from the press die if it is to produce a consistently acceptable tablet. Some compositions will not readily separate from the die, so a flow agent may be added to the mixture to facilitate bulk flow characteristics of the feed fuel. The inclusion of a lubricating additive according to this method of the invention will facilitate the removal of pellets from the pellet press while lubricating.

The flow agents and treatment lubricants used in accordance with this method can be selected such that the bulk friction properties with the specifically formulated gas generating composition are acceptable. Such additives should be chosen such that these additives and their combustion products are non-toxic.

The flow agent should be chosen to have fuel, oxidant, or inert properties, and selected to include nitrate and / or oxygen to balance the gaseous composition. In addition, the flow agent may be dried in anhydrous state when used with the binder to minimize any effect on the combustion rate of the gas generating material. Suitable flow agents that can be used according to this method of the invention include silicic anhydrides such as Tolonox (400 species) commercially produced by Cabot Industries and their Cab-o-Sils, which are flow agents. In addition, fine doping of the gas generating materials with acetates, silicates and suitable oxides will increase their fluidity. Alternatively, desiccants or superdryers such as alumina and silica gel will also act as acceptable flow agents.

In addition, there is an advantage that the flow agent that can act as a combustion ratio catalyst can be applied in various ways when used with the binder. Examples of such flow agents include silicates, carbonates and fumed silicas.

According to this method, the flow agent should not exceed about 0.5% by weight of the total composition and preferably do not exceed about 0.001% by weight of the total composition. Minimizing the amount of flow agent minimizes any effect on the burn rate or other ballistic properties of the composition.

The flow agent may be included in the mixture by simply introducing it into the gas generating component when mixing the gas generating component. Alternatively, the flow agent may be mixed with one or more components prior to mixing all of the components together. However, in order to increase the bulk density of the feedstock, it is desirable to add the flow agent to the component after aggregation. In addition, adding a flow agent after flocculation minimizes the amount of flow agent required.

Other additives

During the treatment of the gas generating material in accordance with the teachings of the present invention, other additives may be included in addition to the binder and flow agent. Binders and flow agents may be selected to act as burn rate catalysts, but burn rate catalysts that do not act as binders or flow agents may be used.

Currently, for use as combustion rate catalysts, it is desirable to select non-toxic materials that are either completely consumed during the combustion of the gas generating material or solidified during combustion and remain with the slag produced during combustion in the generator. Alternatively, materials that can be trapped within the filtration system of the gas generator can also be used to avoid entry of particulate debris into the air bag. Alternatively, combustion rate catalysts can be used that produce particulates less than about PM10 provided that the amount of particulate debris produced is within the industry standard Threshold Limit Values (TLV) for 10 micron (PM10) emissions.

Examples of combustion rate catalysts that may be used in accordance with the teachings of the present invention include metal oxides such as iron oxide, aluminum oxide, titanium oxide and silicon oxide. Other burn rate catalysts that have been successfully used include burn rate inhibitors such as oxamides.

Additional use additives include tracing agents. The tracer acts to color or dope the gas generating material so that it is easily detected in the event of a leak. Tracers may include thermally stable inorganic and organic dyes. Volatile organic dyes can also be used if the particulate condensate produced after combustion is maintained on a PM10 basis.

Depending on the nature of the constituents to be mixed in accordance with the process of the present invention, there is a possibility that static electricity is increased in the mixing zone. Since it is obvious that it will be dangerous in the case of ignition due to electrostatic discharge, it is presently desirable to prepare a mixture in an inert oxygen-free environment. This can be easily solved by using an inert gas such as argon or nitrogen in the mixer. The use of an inert gas to create an oxygen free environment can be advantageously used in conjunction with any of the methods disclosed herein.

Roll coating

One method for producing a gas generating feed-stock in accordance with the teachings of the present invention includes preparing the required amount of components metered in a predetermined proportion, depending on the composition of the gas generating material. The components are then introduced into the rotatable mixer 10 of FIG. 1. The constituents of the gaseous product may be introduced into the mixer in the wet or dry state. It is now desirable to add fuel in the hydrated state and add the oxidant in the dry state, in which wet fog or spray will assist the flocculation. In addition, the use of a vacuum will help to control the size of aggregates formed.

Mixer 10 includes any conventional mixer having a rotatable cavity for receiving components to mix, such as a commercially available pelletizer. Means (not shown) are provided for rotating the mixer 10. Components may include fuel 12, oxidant 14 and additives 16. The additive 16 may include any of the additives set forth herein, such as a combination of binders or flow agents, and may be introduced into the mixture through other introduction mechanisms such as atomizers or liquid feeds.

The mixer 10 is then rotated at a sufficient angular velocity so that the components in the mixer aggregate to form granules or aggregates. When rotating the mixer 10, the tumbling action of the constituents is gentle, that is to say that the constituents are brought into contact with each other, resulting in substantial particle-particle contact, thereby providing an opportunity for the constituents to aggregate.

When rotating the mixer 10, the components are carried over the mixer side until gravity causes the components to drop to the bottom of the mixer, and the components are carried upwards again along the mixer side from the bottom away. However, the action on the components by the rotary mixer 10 consists of an extended contact period after repeated mixing cycles. The components are mixed when the components fall to the bottom of the mixer. When the components are conveyed upwards along the face of the mixer, they are brought into contact with each other substantially without obstacles. It is true that the use of a rotary mixer provides a contact time, which promotes granulation formation through flocculation. The contact time of the particles can be adjusted by varying the angle or pitch of the rotating vessel. The speed at which the mixer rotates should be fast enough that the components do not stick to the mixer 10 wall throughout the range of rotation due to the centrifugal force applied to the components.

By mixing the components in vacuo, any water or other carrier solvent can be removed via reduced pressure boiling. It is also possible to use the reduced pressure boiling to make the product anhydrous, as is generally desirable when preparing non-azide gas generating compositions.

The mixer 10 is preferably of a structure having a centerline discharge port 20 through which aggregates can exit the mixer. The screen 22 is located in the discharge port 20 and the granules to exit the mixer must be crossed. The mesh size of the screen 22 will vary depending on the flocculation requirements of the particular composition made. In general, however, it is contemplated that screen sizes of about 10 mesh to about 200 mesh will be acceptable. For example, if the feed-stock is to be pressurized with tablets 1/4 inch in diameter, it is preferred to use a screen of about 20 to about 60 mesh.

The screen 22 is positioned so that the particles passing through the screen 22 fall back into the mixer 10 with respect to the discharge port 20, so that the particles are exposed to additional tumbling action and are further aggregated. Thus, the use of a 200 mesh screen ensures that agglomerations less than about 100 microns are passed so that all agglomerates exiting the mixer 10 will generally exceed the desired size in the production of about 100 microns-gas generated feed-raw material.

By controlling the amount and type of binding material used in the mixture and the processing pressure, the maximum aggregate size can be limited to an acceptable size. However, in this preferred embodiment, no screen is provided to prevent aggregates made too large from leaving the mixer 10. However, it should be taken into account that additional screens may be provided to control the maximum size particles allowed to exit the mixer 10.

Agglomerates large enough to cross the screen 22 exit the mixer 10 through the discharge port 20. A diverter 24 is preferably provided along the discharge passageway through the discharge port 20 so as to convert the feed-raw material into one of the two containers 26. Once one container is filled, the diverter 24 can be operated to divert the flow to another container, allowing the process to proceed under reduced pressure.

It should be considered that this method can be easily used effectively as a batch process or a semi-batch process. In the case of producing a gas generating material according to the method of the present invention in a semi-batch process, the components are processed until a predetermined amount of aggregates are collected in the container 26, and then the additional components are added to the mixer 10. ) Mixers with centerline discharges as in FIG. 1 are particularly suitable for use in semi-batch processes.

Continuous roll coating processes can also be carried out according to this method of the invention. In order to carry out the continuous process, a mixer with an extended wall is used, such as through the use of a rotary dryer or drum. The mixer is preferably positioned at an angle where components are likely to flow from one end of the mixer to the other. Alternatively, a flight can be used in the mixer to push the material from the inlet to the discharge port.

Continuous mixing

An additional method for producing a gas generating feedstock according to the present invention comprises preparing a required amount of components metered in a proportion according to the composition of the gas generating material and introducing the components into a continuous mixer. . The continuous mixer includes a static housing in which the mixing blade is rotatably disposed. An example of such a mixer is the twin screw extruder 40 of FIG. 2.

Other mixers that can be used successfully according to the method of the present invention include dual ribbon blenders manufactured by JHDay, ribbon blenders manufactured by Babcock-Gardner, ribbon mixers manufactured by Patterson, paddle blenders manufactured by Marion and Michigan Sagninaw. Co-dough such as a model 1000 co-kneader manufactured by APV.

The twin screw mixer 40 includes a housing 42 in which two mixing shafts 44 are arranged for rotation. A wiper blade 46 is attached to the housing that wipes the blade 44 as the shaft rotates, inducing the components to mix in the mixer. As the shaft 44 rotates, the components in the mixer are moved along the length of the mixer by the shaft 44.

According to this method, the constituents used in forming the gas generating feedstock can be introduced into the mixer step by step. Thus, fuel 48 can be initially added as in FIG. 2. Much such mixer 50 can be added far below mixer 40 and mixed in with fuel 48. Finally, oxidant 52 may be added to the fuel 48 and binder 50 mixture and mixed to form the final feed fuel. When rotating the mixing shaft 44, the components are mixed and coagulated to form granules. Loss-in-weight feeders can be used to carefully control the weight percent of the composition. Dosage feeders can be used for volume based compositions.

The relative position of the component feeders can be adjusted according to the particular application. Although various components are introduced into the mixer step by step in the embodiments shown, this method of the present invention may be considered such that all components are introduced at the same location in the mixer. However, by mixing the components in stages, the mixing process can be better controlled to produce a more consistently formulated final product.

Drying steps can be included in this method of the invention. According to one such embodiment, the mixture is introduced into a vacuum 54 to depressurize to about 1 mm Hg and heated to about 75 degrees Celsius to remove water from the mixture.

Static mixing

Another method of the present invention includes preparing a required amount of components weighed at a predetermined ratio according to the composition of the gas generating substance, and introducing the components into the static mixer. As shown in FIG. 3, a static mixer 60 arranged for use in accordance with this method of the invention includes a fuel bin 62 and an oxidant bin 64. The fuel supply tube 66 is connected to the fuel bin 62, and the oxidant supply tube 68 corresponding thereto is connected to the oxidant bin 64.

In this preferred embodiment, feed tubes 66 and 68 are gravity fed. Therefore, the tubes 66 and 68 lead to the bottom mixing zone 70 where the static mixing rod 72 randomly crosses the flow path. Below the mixing zone 70 is provided a fog zone 74 in which the mixture can be applied to the binder. In this preferred embodiment, a pair of ramps 76 at a predetermined angle is disposed below the fog area 74. Behind the lamp 76 of a predetermined angle, a plurality of predetermined angles of screens 78 are located, which are arranged at an angle of θ with respect to the flow path. It will be apparent to those skilled in the art that the number of lamps of an angle and the screen of an angle used may vary depending on the particular composition to be manufactured. In addition, the angle at which each lamp and screen is arranged relative to the flow path can be modified to optimize the process for a particular application.

In operation, a suitable fuel is provided to fuel bin 62 and a suitable oxidant to oxidant bin 64. The diameters of the fuel supply tube 66 and the oxidant supply tube 68 are adjusted in accordance with the final speeds of the fuel 62 and the oxidant 66 such that the fuel and the oxidant are supplied to the mixing region 70 at an appropriate ratio.

When the fuel and oxidant reach the mixing zone 70, they collide with the mixing rod 72 in the flow path. As a result, the fuel and oxidant are mixed considerably.

Depending on the nature of the components that are mixed in the static mixer, there is a possibility of electrostatic buildup in the mixing zone 70. In the case of electrostatic charges, since the risks are obvious inherently, it is preferable to carry out static mixing in an inert environment. This is easily accomplished by using an inert gas such as nitrogen in a static mixer.

After passing through mixing zone 70, the mixed fuel and oxidant move to fog zone 74. The fog may include atomized binders as described herein. In the fog zone 74, the binder 74 is in contact with the fuel and oxidant particles. Therefore, the density of the fog zone 74 is adjusted depending on how much binder 74 will be applied to the constituent mixture.

The particles then come into contact with the lamp 76 at an angle that induces particle-particle contact between the fuel and the oxidant. Since the mixture now contains a binder, the components easily aggregate into granules when moved along the ramp 76 at an angle. When the granulated mixture reaches the screen 78 at an angle, granules of a predetermined size or more for use as feedstock can be easily separated.

In this preferred embodiment, the array angle θ between the lamp 76 and the screen 78 and the flow path is preferably 45 degrees. However, it will be apparent to those skilled in the art that the optimum configuration angle θ may vary depending on the particular component to be mixed and the desired size of the granules to be obtained.

Granules that have fallen through the screen 78 may be reintroduced into the mixer of the fog zone 74. Alternatively, granulated particles that have not yet reached their minimum size may be introduced into a separation process comprising an additional fog zone 80, a predetermined angle ramp 82 and a predetermined angle screen 84, as shown in FIG. Can be.

Depending on the specific composition to be mixed, it may not be necessary to use a binder. Of course, the fog area 74 can be removed if the binder does not need to be used. Then, agglomeration takes place in the mixing region 70. When agglomeration sufficiently occurs in the mixed region 70, the lamp 76 at a predetermined angle can be removed. However, since the particle-particle contact time is very short in the mixing zone 70, in order to obtain sufficient particle size before the mixture passes through the screen 78 at a predetermined angle, the lamp 76 at a predetermined angle is used in most applications. To increase coagulation.

Freeze drying

Another method of the present invention for producing a gaseous feed-stock comprises initially preparing the required amount of components metered in a predetermined proportion, depending on the composition of the gaseous product, to obtain a gaseous feed-stock. As shown in FIG. 4, the component may include a fuel 90 such as BTA and an oxidant 92 such as copper oxide. Additives 94 such as binders may also be included.

The constituents are placed in the mixer 96 and mixed with a solvent such as water 98 such that at least one component of the gaseous product is at least partially dissolved. Depending on the solubility of the constituents being mixed, some heat 100 may be added to the mixture to improve the solubility of one or more constituents. For example, when mixing BTA and copper oxide, it is desirable to heat the mixture to about 100 ° C. to improve the solubility of BTA in water.

The mixture is then passed through a non-contact heat exchanger 102 and cooled beforehand. Non-contact heat exchangers of the type used in this method may be used as long as the component mixture can be cooled without physical contact with the refrigerant of the heat exchanger. Examples of such heat exchangers include shells and tubes, plates and frames, and spiral tubes.

Pump 104 or other means may be used to allow fluid flow to pass through the heat exchanger 102 from the mixer 96. The supercooled mixture then enters cooling tank 106 and has a liquid refrigerant, such as carbon dioxide, ammonia or nitrogen, having a liquidus temperature substantially below 0 ° C. (or below freezing point of the carrier solvent, if not water). Mixed with In the presently preferred method, liquid carbon dioxide is used because it is safe to work and available at low cost.

As the mixture enters the cooling tank 106, the water freezes substantially immediately, so that the constituents are contained in the freezing crystals of the water. The cooling tank 106 has vent holes 108 for releasing gas boiled in the liquid refrigerant when a relatively warm constituent mixture is introduced into the cooling tank 106. By maximizing the amount of pre-cooling in the heat exchanger 102, this loss of liquid refrigerant can be minimized. The frozen mixture was then introduced into sublimation tank 112 and maintained at reduced pressure. In the sublimation tank 112, the mixture may be dried by reduced pressure boiling.

When water is subcooled before entering the cooling tank 106, substantially all of the dissolved fuel (or other components) is not dissolved and is separated from the solution. The energy-saving effect obtained by using such a method was tested by showing a method of applying a gas generating agent using BTA as a fuel, copper oxide as an oxidant, and water as a solvent. The thermal conductivity of water supercooled at -23 ° C is 5.222cal / ° C-cm-hr, and the thermal conductivity of water supercooled at 0 ° C is 5.439cal / ° C-cm-hr. The thermal conductivity of copper oxide at -23 ° C is about 2.853cal / ° C-cm-hr, and the thermal conductivity of copper oxide at 0 ° C is about 2.730cal / ° C-cm-hr. Because of this difference, the crystals of the BTA fuel are selectively moved towards the copper oxide surface. Since phase transitions occur rapidly, the supercooling step must be performed to limit the amount of particulates formed from the dissolved fuel.

After treatment in the sublimation tank 112 to remove water or other solvents, the obtained feed-stock can then be used to produce the final gas product.

Solvent extraction

Another method of the present invention for producing a gaseous feed-stock comprises initially preparing the required amount of components metered in a predetermined proportion, depending on the composition of the gaseous product, to obtain a gaseous feed-stock. As shown in FIG. 5, the component is introduced into the mixer 130. The component may include a fuel 132 such as BAT and an oxidizer 134 such as copper oxide. Additives 136 such as binders may also be included.

The components are placed in the mixer 130 and mixed with a carrier solvent such as water or methylene chloride. In this preferred method, water 138 is used. When the components are mixed in water 138 and at least part of one or more components of the gas generating material are dissolved in water, one or more of the gas generating materials are dissolved, and the remaining components are suspended first solution (140). ) Is formed. Depending on the solubility of the mixed constituents, some heat 142 may be added to the mixture to improve the solubility of one or more of the constituents. For example, when mixing BAT and copper oxide, it is desirable to heat the mixture to about 100 ° C. to improve the solubility of BAT in water.

Then, a second solution 144 may be added to the first solution 140, which may be mixed with the first solution 140 and in which the constituents of the gaseous product are not substantially dissolved. For example, when preparing a gas generating composition in which BAT and copper oxide are dissolved in water, a suitable second solution 144 includes an alcohol such as butanol. Ammonia and other polar solvents can also be used successfully as the second solvent.

For continuous separation, it is preferable to introduce the first solution 140 into the second solution 144 using the dropping tower 146 filled with the second solution 144. It is preferable to introduce the first solution into the second solution 144 by injecting the first solution 140 into the second solution through an immersion nozzle 148 which disperses the small solution into small droplets.

When droplets of the first solution 140 begin to mix with the second solution 144 in the dropping tower 146, the water in the first solution 140 is mixed with the second solution. Since the constituents of the gaseous product solution are not dissolved in the second solution 144, when the second solution 144 is mixed with the first solution 140, the dissolved constituents tend to separate from the solution.

Undissolved constituents suspended in solution act as seeds, making dissolved constituents easy to precipitate from solution. For example, when treating the BTA / copper oxide composition in water, insoluble copper oxide acts as a seed, BTA crystals grow, copper oxide bonds to the coating, and the BTA is separated from the solution.

As described herein, tactifiers or other binders may be used to aggregate the BTA crystals with each other through mechanical bonding. Therefore, any new BTA crystal precipitated in solution can be combined with other granules using a binder.

Then, the aggregate of the gas generating material is removed from the dropping tower 146. Excess water may be removed by conventional drying process 150. The feed-stock obtained is in a form usable for powder injection molding or pellet processing to form the final gas product.

The solution in the dropping tower 146 is circulated continuously through the solution removal process 152 to separate water from the second solution 144 using known solution separation techniques. Subsequently, the second solution 144 may be reversely circulated to the dropping tower 146 to maintain the second solution 144 in the dropping tower 146 in a sufficient amount.

This solution extraction method can be easily used as a batch process by adding a predetermined amount of the second solution 144 to the mixer 130 after the components have been mixed in the first solution 140. The dissolved constituent then leaves the solution and forms a coating on the other particles that act as seeds. The obtained feed-stock can then be processed into the final form.

oil paint

In another method of the present invention, a gas production feedstock is prepared by initially preparing the required amount of components metered in a predetermined proportion, depending on the composition of the gas generating material.

As shown in FIG. 6, the components were introduced into mixer 160. The component may include a fuel 162 such as BAT and an oxidizing agent 164 such as copper oxide. Additives 166 such as binders may also be included.

In the mixer 160, the constituents are mixed with a carrier solvent such as water 168, so that one or more gas generating constituents are dissolved by dissolving one or more constituents of the gas generating substance in water, and the remaining constituents Suspended first solution 170 is formed. Depending on the solubility of the mixed constituents, some heat 172 may be added to the mixture to improve the solubility of one or more of the constituents. For example, when mixing BAT and copper oxide, it is desirable to heat the mixture to about 100 ° C. to improve the solubility of BAT in water.

A second solution 174 is then added to the first solution 170 that does not mix with the first solution 170 and in which the constituents of the gaseous product are substantially insoluble. For example, when preparing a gas generating composition in which BAT and copper oxide are dissolved in water, a suitable second solution 174 includes trichloroethane, tetrachloroethane, nonane, and the like.

Then, the first solution 170 and the second solution 174 are physically emulsified. The mixture can be easily emulsified by methods known in the art. Both in-line mixers and batch mixers for continuous processing are commercially available. Such mixers are generally classified as turbine stirrers having an ambient speed of about 3.30 to about 3.56 m / s.

The constituents of the gaseous product may then be collected via separation process 176. The components are preferably separated by centrifugation. Alternatively, a sedimentation tank or coalescing tank connected to the in-line coalescer may be used. Since the constituents of the gaseous product are not dissolved in the second solution 174, when the water is emulsified with the second solution, it is separated. When separated, significant particle-particle contact occurs between the various components, resulting in particle agglomeration. By controlling the temperature and relative concentration of the liquid during emulsification, the size of the particles can be controlled.

Excess water may be removed by conventional drying process 178. The feed-stock obtained is in a form usable for powder injection molding or pellet processing to form the final gas product.

Azeotropic distillation

This method of the present invention can advantageously be used in combination with other methods as an economical process for drying the gas generating components. It is also possible to prepare feed-stocks independently of these methods. According to this method, a gas production feedstock is prepared by initially preparing the required amount of constituent components weighed in a predetermined proportion according to the composition of the gas generating material.

The components are mixed in a conventional manner using a first solvent (generally water) and at least part of the components of at least one gas generating material are dissolved. Such mixtures, for example fuels, oxidants, water and other additives used in the gas generating composition as described herein are in the form of slurries.

A small amount of the second solvent is then added to the mixture and mixed with the mixture. The twenty-second solvent is selected to mix with the first solvent and form an azeotrope with the first solvent. By limiting the amount of the second solvent mixed with the mixture, it should be ensured that no constituents that can be dissolved in the first solvent are separated from the solution. This problem can be avoided when the second solvent is selected such that all the dissolved constituents are also dissolved in the second solvent. In a system using water as the first solvent, some acceptable solvents such as benzene, toluene, ethanol, propanol and the like that can be used successfully can be used as the second solvent.

When the solvent is azeotropically removed from the mixture, the concentration of fuel and / or other constituents that can be dissolved becomes supersaturated. Therefore, the dissolved material quickly crystallizes out of solution, and a coating can be formed on the surface of the insoluble component.

The combined constituents were then distilled under reduced pressure or thermal distillation to remove both solvents to prepare anhydrous feedstock. Compared to most known methods, it is important that the amount of energy required to completely form the anhydrous feedstock is small. However, this method can be advantageously used as a method of drying the hydrated gas generating composition.

The feed-stock obtained is in a form usable for powder injection molding or pellet processing to form the final gas product.

Spray drying

Another method for producing other gas generating feed-stocks according to the teachings of the present invention comprises initially preparing the required amounts of components metered in proportions according to the composition of the gas generating material. The constituents are mixed with a carrier solvent such as water to dissolve one or more constituents of the gas generating substance in water to dissolve one or more gas generating constituents, and the remaining constituents are suspended in solution. Depending on the solubility of the mixed constituents, some heat can be added to the mixture to improve the solubility of one or more of the constituents. For example, when mixing BAT and copper oxide, it is desirable to heat the mixture to about 100 ° C. to improve the solubility of BAT in water.

Some advantages can be obtained by using solvents other than water. For example, by using liquefied ammonia as a solvent, thermal sensitivity problems can be reduced. In addition, for mixtures dissolved in liquefied ammonia, rather than mixtures dissolved in water, the energy required to treat the material as feedstock can be reduced.

Additives such as binders may also be included in the mixture, alone or in combination with other additives based herein. The mixture is then sprayed with airflow or vacuum through an atomizer or other nozzle and dried.

In the airflow or vacuum, the surface of the droplets first dry to form a crystalline shell surrounding the rest of the droplets. By thoroughly mixing the component mixture prior to spray drying, most droplets have components that are not dissolved. As a result, undissolved constituents are surrounded by crystal shells formed when the water in the droplets dries. Undissolved constituents act as seeds to promote the formation of crystals on the seeds as the water dries. During further drying of the droplets, the remainder of the dissolved constituents crystallizes, ultimately forming a very fine crystal structure containing both fuel and oxidant.

By including the binder, during drying the droplets containing no harmful components are not separated. In addition, when a binder is used, the particles are slightly aggregated due to particle-particle contact between the particles in the air stream during the drying process.

Aggregates are then collected, used as feedstock, compressed into pellets, injection molded and cut into pellets, or molded into other preferred shapes.

Fluidized bed

Another method of the present invention for preparing a feed-stock of a gas generating material is achieved by preparing a required amount of constituent components weighed in a predetermined proportion depending on the composition of the gas generating material having a non-azide fuel. As shown in FIG. 7, the components are introduced into the fluidized bed 190.

Any fluidized bed commercially available can be used as the fluidized bed 190 according to the techniques of the present invention. This fluidized bed works ideally as a continuous process. While capable of operating as a batch process, such processes require the processing of large amounts of material in order to obtain acceptable production rates. In the case of treating a strong substance such as a gas generating substance according to the technique of the present invention, a large amount of the substance at once can pose a safety risk. However, it is now desirable to operate the fluidized bed in a continuous process. If the fluidized bed is operated in a continuous process, it is estimated that less than about 500 pounds of constituents of the material being processed are used in the process producing 200 pounds per hour.

As shown in FIG. 7, a typical fluidized bed consists of an elongated planar surface 192 arranged with many small holes 194 through which fluid, typically ambient air, can be pumped through at a pressure of about 3-4 psi. The planar surface 192 is typically mounted at an angle Ø about 4 degrees with respect to the horizontal, so that gravity can move the material from one end of the fluidized bed to the other. In other fluidized bed arrangements, air is injected at a differential pressure that provides horizontal propulsion to cause the material to move along the fluidized bed. Such an arrangement can also be used in this method of the invention.

In operation, the components are introduced into the first zone 198 at the inlet 196 of the fluidized bed 190 to mix the components together. The components are preferably introduced into the fluidized bed in a dry state via a loss-in-weight feeder. For example, a feeder for fuel 200 and a feeder for oxidant 202 may be used. Those skilled in the art will appreciate that various types of feeders may be used for this purpose. And for some types of compositions, it is desirable to mix the components before introducing them into the fluidized bed so that there is no need to use multiple feeders. Alternatively, one or more constituents may be dissolved in a solvent and introduced into the fluid phase in liquid form.

Once the constituents have passed through the first zone 198, they are mixed together into the second zone 204, and a solvent 206 is introduced into the mixture to promote coagulation. At this time, a binder may also be added, and the binder is preferably dissolved in a solvent. Water is generally the solvent of choice because of its low cost. Water is added at a temperature of about 60 to about 100 ° C, preferably not exceeding about 85 ° C. While continuing to operate the fluidized bed in the second zone 204, the mixture is further mixed to cause the components to aggregate.

Finally, the constituents can be introduced into the third zone 208 so that a flow agent 210 can be added to the mixture along with other additives. Water is removed from the mixture in the third zone 208. This can be done by injecting preheated air through the aperture 194 of the planar surface 192 in the third zone 208 of the fluidized bed. Alternatively, excess water can be evaporated by providing additional heat using a non-contact heat exchange surface. The pressure when gaseous medium is injected through the holes in the fluidized bed must be reduced in the third zone 208 so that the aggregates formed are not broken by excessive mixing in the third zone.

The dried agglomerates are then removed through the fluid bed outlet 212 and treated with the final gaseous product.

Particle grinding

Another method of the present invention for preparing a feed-stock of a gas generating material, in particular a gas generating material having a non-azide fuel, is to prepare a required amount of components initially weighed in a proportion according to the composition of the gas generating material. To achieve. The components may include fuels, oxidants and any suitable additives. The additive may include any kind of additive described herein, such as in combination with a binder or flow agent. This method is particularly suitable for use in the production of gas generating materials in agglomerated form from raw materials.

The component is introduced into the particle size reduction device. Among the devices suitable for use in the method of the present invention are ball mills, pin mills, hammer mills, fluid energy mills, stator mills and ultrasonic grinders. The components are also ground while being mixed.

This method can also be advantageously used to improve the combustion rate of the gas generating material. By reducing the size of the gas generating material, higher combustion rates are obtained. This method can be used in combination with other processes described herein for producing a gas generating feedstock.

As described above, the present invention provides a method for treating a gas generating composition for economically and efficiently producing a feed-raw material that is easily separated from a mold and that can be compressed into a gas producing tablet having a fracture strength sufficient to meet industry standards. It can be seen that it provides.

The process of the present invention allows for mass treatment of gas generating materials, especially new non-azide based compositions, to obtain a net composition at the macromolecular level.

The method of the present invention can be incorporated in various embodiments, several of which have been described above. The invention can be embodied in other forms without departing from its spirit or essential elements. The described embodiments are to be considered in all respects only as illustrative and not restrictive, and therefore the scope of the present invention is indicated by the appended claims rather than the foregoing description. All changes that come within the meaning and range of equivalency of the claims are to be embraced within this scope.

Claims to be protected by a patent include:

Claims (74)

According to the composition of the gas generating material containing the non-azide fuel, preparing a required amount of components weighed in a predetermined ratio; Mixing the components of the gas generating material together so that they contact each other on a surface; And including a sufficient amount of binder in the mixture to cause the components of the gas generating material to mix and agglomerate to form granules. The method of claim 1, wherein the gas generating material comprises a fuel composed of bitetrazolamine and an oxidizing agent composed of copper oxide. The method of producing a feed-stock for gas production according to claim 1, wherein the binder is water soluble under the mixing process conditions. The method of claim 1, further comprising adding a carrier solvent to the constituents. 5. A process according to claim 4, wherein said carrier solvent consists of water. 6. The method of claim 5, wherein the step of adding the carrier solvent comprises atomizing water and introducing atomized water into the components. 5. The method of producing a feed-stock for gas production according to claim 4, further comprising, after the components have been sufficiently aggregated, drying the components to remove the carrier solvent. The method of claim 1, wherein the binder has a melting point of about 200 ° C to 500 ° C. The method of claim 1, wherein the binder comprises a sufficient amount of one or more selected from the group consisting of nitrates, nitrogen, and oxygen to balance the gas generating constituents. The method of claim 1, wherein the binder can be dried in anhydrous state. The monomer and polymer according to claim 1, wherein the binder is at least 2% solubility in (a) nitrate, (b) sugar, (c) agar, (d) gum, (e) coupling agent, (f) carrier solvent. , (g) saponified wax and oil, (h) siloxane, (i) carbonate, (j) resinate, (k) stable oxide, and (l) silicate. Process for preparing feedstock raw materials. 2. The process of claim 1 wherein said binder is about 0.01 to 2.5 weight percent of the prepared feed stock. 13. The process of claim 12, wherein said binder is about 0.01 to 1.5 weight percent of the feed-stock prepared. According to the composition of the gas generating material containing the non-azide fuel, preparing a required amount of components weighed in a predetermined ratio; Introducing constituents of said gas generating material into a rotary mixer; Rotating the mixer to cause the components to aggregate in the mixer to form granules. 15. The gas production feed of claim 14, further comprising passing the granules through a screen having a mesh size corresponding to the desired granule size to remove coagulated granules that do not pass through the screen. Method of manufacturing raw materials. 15. The method of claim 14, wherein the step of rotating the mixer is followed by drying the mixture in anhydrous state. 15. The method of claim 14, wherein the rotating of the mixer is performed under inert environmental conditions by charging the mixer with an inert gas selected from the group consisting of argon and nitrogen. According to the composition of the gas generating material containing the non-azide fuel, preparing a required amount of components weighed in a predetermined ratio; Introducing constituents of said gas generating material into a continuous rotary mixer comprising a static housing disposed therein for rotation of said mixing blades; Rotating the mixing blades to cause the components to agglomerate in a mixer to form granules. 19. The supply of gas of claim 18, further comprising the step of including a sufficient amount of binder in the mixture to cause components of the gas generating material to agglomerate to form granules while the mixing blade rotates. Method of manufacturing raw materials. 19. The supply of claim 18, wherein introducing the constituents of the gaseous product material into the continuous mixture comprises introducing the constituents at different locations along the continuous mixer. -Preparation of raw materials. 19. The method of claim 18, further comprising adding water to the gas generating components. 22. The method of claim 21, further comprising the step of drying the aggregated constituents in anhydrous state under vacuum. Preparing a required amount of components metered in a predetermined proportion, according to the composition of the gas generating material containing the oxidant and the non-azide fuel; Introducing the constituents of the gas generating material into a static mixer to agglomerate the constituents in the mixer to form granules. The method of claim 23, wherein Introducing the constituents of the gas generating material into a static mixer under inert environmental conditions. 25. The method of claim 24, wherein said inert environmental conditions are provided by charging said static mixer with an inert gas selected from the group consisting of argon and nitrogen. 24. The method of claim 23, wherein after introducing the constituents of the gas generating material into the static mixer, the constituents cross one or more ramps of a predetermined angle to induce contact between the fuel and the oxidant particles. Method of producing a feed-raw material for generating gas. 24. The feed-stock for gas production according to claim 23, wherein after introducing the constituents of the gas generating material into the static mixer, the constituents are passed through at least one angled screen having a constant mesh size. Manufacturing method. According to the composition of the gas generating substance, preparing a required amount of components weighed in a predetermined ratio; Mixing the components in a carrier solvent in which one or more of the components of the gas generating material are dissolved; Freezing the carrier solvent; And A method of making a feed-stock for producing a gas, comprising the step of applying a sufficient amount of heat while adjusting the pressure to cause the frozen solvent to sublimate to separate the components from the solution. 29. The method of claim 28 wherein the gas generating material comprises a non-azide fuel. 29. The method of claim 28, wherein the carrier solvent consists of water. 29. The method of claim 28, further comprising the step of including a sufficient amount of binder in the mixture to cause the components of the gas generating material to mix and agglomerate to form granules. 29. The method of claim 28, wherein said freezing step comprises freezing the mixture in a refrigerant. 33. The method of claim 32, wherein the refrigerant is selected from the group consisting of nitrogen, ammonia, and carbon dioxide. 33. The method of claim 32, wherein the step of supercooling is performed in a non-contact heat exchanger prior to freezing the mixture in the refrigerant. 29. The method of claim 28, further comprising drying the mixture in anhydrous state under reduced pressure, boiling conditions. According to the composition of the gas generating substance, preparing a required amount of components weighed in a predetermined ratio; Mixing the components in a first solution in which at least one of the components of the gas generating material is at least partially dissolved; Mixing the first solution with a second solution selected from a solution that is compatible with the first solution and that does not substantially dissolve the components dissolved in the first solution; and Removing the aggregates of gaseous material precipitated from the mixture of the first solution and the second solution. 37. The method of claim 36 wherein the first solution comprises water. 38. The method of producing a feed-stock for gas production according to claim 37, wherein the second solution comprises a polar solvent. 37. The method of claim 36 wherein the gas generating material comprises a non-azide fuel. 37. The method of claim 36, further comprising the step of including a sufficient amount of binder in the mixture to cause the agglomerates to precipitate from the first and second solutions so that the components of the gas generating material aggregate to form granules. Process for producing feed-raw material for gas production. 37. The gas of claim 36, wherein mixing the first solvent and the second solvent comprises introducing a first solvent substantially to the top of the dropping tower filled with the second solvent. Process for producing feed-raw material for production. 42. The method according to claim 41, wherein the flow of the mixture of the first solution and the second solution is removed from the dropping tower, and the mixture is processed to remove the first solution from the second solution. Method for producing a feed-raw material for producing a gas, characterized in that further comprising the step of re-introduction into the dropping tower. 37. The supply of gas of claim 36, further comprising the step of removing the aggregate of the gaseous product precipitated from the mixture of the first and second solutions, followed by drying the aggregate to anhydrous state. Method of manufacturing raw materials. According to the composition of the gas generating substance, preparing a required amount of components weighed in a predetermined ratio; Mixing the components in a first solution in which at least one of the components of the gas generating material is at least partially dissolved; Introducing into said mixture a second solution selected from a solution that is not miscible with said first solution and that does not substantially dissolve the constituents dissolved in said first solution; Physically emulsifying the mixture; And Removing the aggregates of gaseous material precipitated from the mixture. 45. The method of claim 44, wherein the first solution comprises water. 46. The process of claim 45, wherein said two solutions are selected from the group consisting of trichloroethane, tetrachloroethane and nonane. 45. The process of Claim 44, further comprising the step of including a sufficient amount of binder in the mixture to cause components of the gas generating material to agglomerate to form granules as the mixture is emulsified. Way. 45. The method of claim 44, wherein the gas generating material comprises a non-azide fuel. 45. The method of claim 44, wherein removing the aggregates comprises treating the mixture with a centrifuge. 45. The method of claim 44, wherein the step of removing the aggregates comprises introducing the mixture into a precipitation tank to cause the aggregates to precipitate from the solution mixture. According to the composition of the gas generating substance, preparing a required amount of components weighed in a predetermined ratio; Mixing the components in a first solvent in which at least one of the components of the gas generating material is at least partially dissolved; Introducing into said mixture a second solvent selected from a solvent that is miscible with said first solvent and also forms an azeotropic mixture with said first solvent; Mixing the gas generating material, the first solvent, and the second solvent together; And Azeotropically distilling the solvents. 53. The method of claim 51 wherein the gas generating material comprises a non-azide fuel. 53. The method of claim 51, wherein the first solvent comprises water. 54. The process of claim 53 wherein the second solvent is selected from the group consisting of benzene, toluene, ethanol and propanol. 54. The feed-stock for gas production of Claim 51, further comprising the step of including a sufficient amount of binder in the mixture to cause the components of the gas generating material to agglomerate to form granules while the components are mixed. Manufacturing method. Preparing a predetermined amount of a gas generating composition in a hydrated state; Adding to said gaseous composition a solvent selected from miscible with water and forming an azeotropic mixture with water; And azeotropically distilling the solvent until the gas generating composition becomes anhydrous. 59. The method of claim 56, wherein said second solvent is selected from the group consisting of benzene, toluene, ethanol and propanol. According to the composition of the gas generating material containing the non-azide fuel, preparing a required amount of components weighed in a predetermined ratio; Mixing the components in a first solution in which at least one of the components of the gas generating material is at least partially dissolved to form a mixture; Spraying the mixture through a nozzle configured to separate the mixture into droplets that will dry as they move through an air stream to form aggregates; And A method for producing a feed-stock for gas production, comprising collecting the aggregates. 59. The method of claim 58, wherein spraying the mixture comprises spraying the mixture with an air stream. 59. The method of claim 58, wherein spraying the mixture comprises spraying the mixture in vacuo. 59. The method of producing a feed-stock for producing gas according to claim 58, wherein the first solvent comprises water. 59. The method of claim 58, wherein the first solution contains no water, thereby reducing the temperature sensitivity of the mixture. 59. The gas production feed of claim 58, further comprising the step of including a sufficient amount of binder in the mixture to cause components of the gas generating material to agglomerate to form granules while the mixture is sprayed into the air stream. Method of manufacturing raw materials. According to the composition of the gas generating material containing the non-azide fuel, preparing a required amount of components weighed in a predetermined ratio; Introducing the components to the inlet end of the fluidized bed; Injecting an amount of fluid medium through the fluidized bed to mix the components; Introducing a solvent while continuing to mix the components to cause the components to aggregate; Advancing the components to a dry zone; And Removing the solvent from the constituents after sufficient agglomeration has occurred. 65. The method of claim 64, wherein introducing the constituents to the inlet end of the fluidized bed comprises introducing the constituents in a dry state. 65. The method of claim 64, wherein the solvent comprises water. 67. The method of claim 66, wherein the water is introduced at a temperature of about 60 ° C to 100 ° C. 68. The method of claim 67, wherein the water is introduced at a temperature of about 60 ° C to 85 ° C. 67. The method of claim 66, wherein removing the solvent from the constituents comprises pre-heating the fluid medium and injecting it into a fluidized bed in a dry zone. 65. The method of claim 64, further comprising lowering the pressure to the pressure at which the flow medium is injected into the drying zone. 65. The method of claim 64, further comprising the step of including a sufficient amount of binder in the mixture to cause components of the gas generating material to mix and aggregate to form granules. The method of claim 64, wherein The method of producing a feed-stock for producing a gas further comprising the step of including a flow agent in the mixture. According to the composition of the gas generating substance, preparing a required amount of components weighed in a predetermined ratio; And simultaneously grinding and mixing the components by means of a particle size reducing device. 74. The gas production feed of Claim 73, further comprising the step of including a sufficient amount of binder in the mixture to cause components of the gas generating material to mix and agglomerate to form granules in a particle size reduction apparatus. Method of manufacturing raw materials.