FR2870845A1 - Composition, useful e.g. for production of gas, comprises a fuel and an oxidizing agent, where the fuel comprises a product (glycine or its derivatives) - Google Patents

Abstract

Composition (I) for production of gas, comprises a fuel (A) and an oxidizing agent (B), where (A) comprises a product (glycine or its derivatives).

Description

The present invention relates to a gas production composition

  used in a gas generator for an airbag or air bag.

  The gas producing agents used in gas generators for air bags generally comprise a fuel, an oxidizing agent and a binder and various additives; recently, instead of gas-producing agents having an azide compound which produces harmful gases, as a fuel, gas-generating agents having a safer, non-azide compound have been used as fuel. .

  To protect the safety of passengers by inflating an airbag as programmed in the event of a collision of an automobile, apart from not producing harmful gases, it is desirable that a production of gas used in a gas generator for an airbag satisfies for example the following three requirements.

  (a) A low combustion temperature to reduce the thermal damage to the airbag; (b) A small amount of combustion residues to prevent the airbag from being damaged by the penetration of the combustion residue into the air bag. the airbag, (c) A high rate of combustion of the gas generating agent to inflate and expand the airbag within a prescribed time interval (typically about a few tens of milliseconds).

  US 2003-094225A1 discloses, as a low residue generating gas generating composition, a composition comprising nitrouracil or the like and basic copper nitrate, and US 2003 / 145921A1 described, as a gas generating composition having a combustion temperature of 2100 K or less, comprising a binder / fuel / oxidizing agent.

  Concerning requirement (a), in the case where the combustion temperature is set to a high value so as to appropriately maintain the combustibility of the gas generating agent, which is an explosive, a large amount of amount of refrigerant in the gas generator to suppress the thermal damage applied to the airbag.

  Concerning the requirement (b), in the case where the amount of combustion residues is high, to suppress the evacuation of the combustion residue in the airbag, it was again necessary to place a large quantity of a refrigerant in the generator gas.

  Concerning requirement (c), in the case where the combustion rate is too low, it may not be possible for the airbag to be inflated within a prescribed time interval.

  However, if the combustion temperature of the gas generating agent is reduced to meet requirement (a), then the burning rate also decreases and therefore it is no longer possible to satisfy the requirement ( vs). In addition, even if requirement (a) is satisfied, it is not possible to reduce the amount of refrigerant unless requirement (b) is also satisfied.

  An object of the present invention is to provide a gas generating composition, with which the production of harmful gases during combustion can be suppressed, and further all requirements (a) to (c) can be satisfied.

  As means for achieving this objective, the present invention provides a gas-producing composition comprising a fuel and an oxidizing agent, and as necessary, a binder and additives, the gas-producing composition comprising at least one product selected from the group comprising glycine and a derivative of glycine, as a fuel.

  According to a variant, the gas production composition according to the invention further comprises a binder is an additive.

  With the gas production composition according to the present invention, the production of harmful gases upon combustion can be suppressed. In addition, the gas-producing composition according to the present invention satisfies all the requirements (a) to (c) indicated above and therefore the amount of a refrigerant introduced into the gas-producing agent can be reduced, and therefore the gas generator itself may have a lower weight and further damage to an air bag may be prevented, and thus safety in operation can be improved.

  The fuel used in the gas-producing composition according to the present invention comprises at least one fuel selected from the group consisting of glycine and a glycine derivative; if necessary, combustible components other than glycine and a derivative thereof may be used together.

  Examples of the glycine derivative include glycylglycine, anhydrous glycine, glycine anhydride, glycine metal salts, complex glycine-metal coordination salts, alanine, iminodiacetic acid, creatine and creatinine .

  In the case of using another fuel component together with glycine or a derivative thereof as a fuel, the content of the glycine or glycine derivative in the fuel is preferably not less than 50% by weight, more preferably not less than 70% by weight, and even more preferably not less than 80% by weight, with only glycine or glycine derivative being used (It should be noted, however, that even in this case it is possible that small quantities of other combustible constituents are contained as impurities or to such a degree that the effects are not affected at all.

  Examples of other combustible constituents include at least one nitrogen-containing compound selected from the group consisting of tetrazole derivatives, for example 5-aminotetrazole, derivatives of biterazole such as diammonium biterazole, derivatives of triazole such as 4-aminotriazole, guanidine derivatives such as dicyandiamide, nitroguanidine and guanidine nitrate, triazine derivatives such as trihydrazinotriazine, and oxamide, oxalate and the like. ammonium, azodicarbonamide and hydrazodicarbonamide.

  As the oxidizing agent used in the gas-producing composition according to the present invention, it is preferable to use a mineral oxide.

  An example of such mineral oxides is more preferably at least one product selected from the group consisting of copper nitrate, sodium nitrate, potassium nitrate, strontium nitrate, sodium perchlorate, potassium perchlorate and strontium perchlorate, basic.

  The gas producing composition of the present invention may include a binder as necessary. An example of such a binder is at least one product selected from the group consisting of carboxymethylcellulose (CMC), sodium carboxymethylcellulose (CMCNa), potassium carboxymethylcellulose, ammonium carboxymethylcellulose, cellulose acetate, and the like. cellulose acetate butyrate (CAB), methylcellulose (MC), ethylcellulose (EC), hydroxyethylcellulose (HEC), ethylhydroxyethylcellulose (EHEC), hydroxypropylcellulose (HPC), carboxymethylethylcellulose (CMEC) , microcrystalline cellulose, polyacrylamide, polyacrylamide amine, polyacrylhydrazide, acrylamide - metal acrylate copolymer, polyacrylamide - polyacrylic ester copolymer, polyvinyl alcohol, acrylic rubber, guar gum, starch and silicone.

  Among these products, if we consider adhesion performance, cost, flammability, etc. of the binder, it is preferable to choose a water-soluble cellulose compound, sodium carboxymethylcellulose (CMCNa) being particularly preferable.

  According to a preferred variant, the gas production composition according to the invention is a composition in which the fuel is glycine, the oxidizing agent is copper nitrate and the binder is carboxymethylcellulose or a salt thereof.

  The gas production composition according to the present invention may include, as necessary, any of various additives that are included in publicly known gas producing agents. As additives of this type, it is possible to use at least one product chosen from the group comprising metal oxides such as copper oxide, iron oxide, zinc oxide, cobalt oxide and oxide. manganese, molyldene oxide, nickel oxide, bismuth oxide, silica and alumina, metal carbonates or basic metal carbonates such as, for example, cobalt carbonate, calcium carbonate, basic zinc carbonate and basic copper carbonate, composite compounds of a metal oxide or hydroxide such as Japanese acid clay, kaolin, talc, bentonite, diatomaceous earth and hydrotalcite, acid salts of a metal such as sodium silicate, mica molybdate, cobalt molybdate and ammonium molybdate, molybdenum disulfide, calcium stearate, silicon nitride and silicon carbide.

  The contents of the various constituents in the gas production composition according to the present invention can be chosen from the following ranges.

  For the fuel, preferably 1 to 50% by weight, more preferably 5 to 40% by weight, and still more preferably 10 to 30% by weight of the gas-producing composition.

  For the oxidizing agent, preferably 20 to 99% by weight, more preferably 40 to 95% by weight, and still more preferably 60 to 90% by weight, of the gas-producing composition.

  In the case where a binder is included, preferably 0.1 to 30% by weight, more preferably 0.5 to 20% by weight and even more preferably 3 to 10% by weight of the binder composition. gas production.

  In addition, in the case where the inclusion of additives is necessary, 0.01 to 20 parts by weight per 100 parts by weight of the fuel, the oxidizing agent and the binder can be included in total, although this varies depending on the type of additive.

  For the gas production composition according to the present invention, in order to achieve the object of the present invention, it is particularly preferable to use a combination of glycine as fuel, basic copper nitrate as a oxidizing agent and carboxymethylcellulose or a salt thereof (in particular CMCNa) as a binder.

  The gas producing composition according to the present invention may be in the form of a molded article having a desired shape such as, for example, a single perforation cylinder, a porous cylinder, pellets or the like. Such a molded article may be made using a method, in which water or an organic solvent is added to the gas-producing agent, and mixing is effected, followed by extrusion molding (for a molded article). in the form of a single perforation cylinder or a porous cylinder) or a method in which a compression molding is performed using a tablet making device or the like (for a molded article having the shape of a tablet ); the method described in JP-A N 2001-342 091 can also be used.

  The gas production composition according to the present invention can be used for example in any of different vehicles in an airbag inflation system for the driver side (gas generator), an inflation device for an airbag for the airbag. front passenger side, a side airbag inflator, a curtain inflation device, a knee protection system inflation device, an inflatable seat belt inflation device, a tubular system inflator or a device for inflating a pre-tensioning device.

  Apart from its possible use as a gas-producing composition for an inflation device (gas generator), the gas-producing composition according to the present invention can also be used as an ignition agent designated as being an amplifier (or intensification system) for transferring energy from a detonator or a primer for a gas-producing composition.

  Measurement methods will now be provided for examples and comparative examples. Note that "parts" in the following refers to "parts by mass".

  (1) Process for preparing a cylindrical bead.

  A powder having the composition of each example and each comparative example (mixed powder for molding, as shown in Table 1) was introduced into the mortar side of a prescribed die, maintaining compression at a pressure of 14, 7 MPa for five seconds using a hydraulic pump from the end face on the crushed side, and then the molded article was removed, resulting in a cylindrical bead having an outside diameter of 9.5 mm and a length of 12.70 mm. A chemical reaction type adhesive based on an epoxy resin ("BONDQUICK 30" manufactured by Konishi, Co., Ltd) was applied to the back side of the cylindrical bead, followed by thermosetting for 16 hours at 110 ° C. , which resulted in a sample, for which the inflammation did not occur from the lateral side, but on the contrary the ignition and therefore the combustion occurred only from one side end (combustion occurs on one side only).

  (2) Method of measuring the rate of combustion.

  Each sample cylindrical bead was installed in a SUS sealed chamber of 1 liter inner volume and, while completely purging the interior of the chamber with nitrogen, pressurized to and stabilization at 7 MPa. Then, a prescribed current is passed through a nichrome wire in contact with an end face of the bead, thereby causing ignition and hence combustion by means of the fusion energy of the nichrome wire. The behavior of the pressure in time in the chamber was determined using a logger diagram, the time elapsed from the start of the combustion to the maximum pressure was determined from the scale on the diagram, and the value calculated by dividing the bead length before combustion by the elapsed time was taken as the burning rate.

  (3) Process for measuring gas concentrations.

  Each sample cylindrical bead (mass 2.00 g) was installed in a SUS sealed chamber with an internal volume of 1 liter and, while completely purging the interior of the chamber with nitrogen, a baking process was performed. in pressure up to and stabilization at 7 MPa. Next, a prescribed current is passed through a nichrome wire in contact with an end face of the cord, thereby causing ignition and thus combustion by means of the fusion energy of the nichrome wire. It was waited for 60 seconds for the gas in the chamber to become uniform, then a portion of an open blocking device of a Tedlar bag with a prescribed stopping device was connected to an evacuation portion of the chamber. From the chamber gas, a sample was taken by transferring the flue gas into the chamber in the Tedlar bag, and the NOO2r NO, NH3 and CO contents were measured using Gastec gas detection tubes (N 10 for detection of NO2 and NO, N 3L for the detection of NH3 and N 1N for the detection of CO) using a GV-100S detector manufactured by GASTEC CO.

  (4) Mass of recovered residues After completing the test below ((3) method of measuring gas contents), the condition inside the chamber was visually observed and furthermore the residues were recovered. inside the chamber, and the mass of the residues was measured after drying for 16 hours at 110 C.

Example 1

  14.8 parts of glycine and 85.2 parts of basic copper nitrate were passed twice through a SUS screen having 300 μm mesh size to make the grains uniform, and mixed together to obtain a uniform grain size. composition according to the present invention. The measurement results are shown in Table 1.

Example 2

  21.69 parts of glycine and 73.31 parts of basic copper nitrate, and 5 parts of CMCNa were passed through a SUS screen having 300 μm mesh mesh to make the grains uniform, and thus obtained. a mixed powder. 20 parts of ion exchange water were added to 100 parts of this mixed powder, and careful mixing was carried out, followed by drying for 1 hour at 100 ° C., which resulted in a composition according to the present invention. The measurement results are shown in Table 1.

  Comparative Examples 1 and 2 Using the constituents shown in Table 1, compositions were obtained respectively as for Examples 1 and 2. The measurement results are shown in Table 1.

Examples 3 to 7

  Using the constituents indicated in Table 1, compositions of the present invention were obtained as for Example 1 in the case where the CMCNa is not used or as in Example 2 in the case of use. of CMCNa. The measurement results are shown in Table 1.

Table 1

  Example Example Comparative Example 1 2 1 2 3 4 5 6 7 Glycine 14.8 21.69 25.06 Glycylglycine 29.77 26.08 26.08 Glycine anhydrous 29.77 Nitrate 53.36 46.21 guanidine Nitrate 85 , 2 73.31 46.64 48.79 68.92 68.92 36.66 Basic copper Perchlorate 70, 23 70.23 33.28 Potassium CMCNa 5.00 5.00 5.00 5.00 5.00 Speed 13, 12 13.92 9.91 9.64 13.28 13.94 13.28 13.94 23.76 Combustion (mm / s) Grade NO2 0 0 0 0 2.5 0 2.5 0 0 NO 12 14 42 19 19 24 19 24 2 (ppm) NH3 0 20 1 29 0 2 0 2 2 CO 100 270 110 410 100 280 100 280 290 Mass of 0.89 0.79 - - - 0.72 - 0.74 0.63 residues (g) As indicated above, for the compositions of the examples, the amount of harmful gases was removed, the amount of harmful gases generated during the combustion was suppressed. In addition, when visually observing the condition inside the chamber after completion of the "(3) gas concentration measurement method" test, the condition was as indicated below .

  For Example 1 only a single, almost cylindrical, metallic copper mass was observed as a residue with very good slag formation and for Example 2 only a single mass of metallic copper was observed again almost cylindrical. In addition, for Examples 4 and 6, only a cylindrical metallic copper mass was observed as a residue with very good slag formation.

  For Comparative Example 1, a dispersed residue was observed in the form of countless fine metallic copper particles. Dispersion in the form of such fine metallic copper particles can damage the airbag as it inflates and expands. For Comparative Example 2, a dispersed residue was observed in the form of several metallic copper particles having a size of about 1 mm. Dispersion in the form of such metallic copper particles can damage an airbag as the airbag inflates and expands.

  In this way, the compositions of the examples have a high safety with respect to the combustion gases, and a good slag capacity, and also a low combustion temperature and furthermore the combustion rate is sufficiently high.

Claims (6)

  A gas production composition, characterized in that it comprises a fuel and an oxidizing agent, the fuel comprising at least one product selected from the group consisting of glycine and a derivative of glycine.   2. Gas production composition according to claim 1, characterized in that the glycine derivative is glycylglycine, anhydrous glycine, glycine anhydride, glycine metal salts, complex glycine-metal coordination salts. , alanine, iminodiacetic acid, creatine or creatinine.   3. Gas production composition according to either of claims 1 and 2, characterized in that the oxidizing agent is at least one mineral oxide selected from the group comprising copper nitrate, sodium nitrate, potassium nitrate, strontium nitrate, sodium perchlorate, potassium perchlorate and strontium perchlorate, basic.   4. Gas production composition according to claim 1, characterized in that it further comprises a binder and an additive.   5. The gas production composition according to claim 4, characterized in that the binder is a water-soluble cellulose compound.   6. Gas production composition according to claim 4, characterized in that the fuel is glycine, the oxidizing agent is basic copper nitrate and the binder is carboxymethylcellulose or a salt thereof.