JPH0570275A - Combustion-controlled propellant composition - Google Patents

Abstract

PURPOSE:To develop a solid combustion-controlled propellant of which combustion is stopped and reignited by the change of pressure by mixing a liq. binder consisting essentially of propylene glycol into the solid mixed powder of carbon powder and an oxidizing agent, heating and curing the mixture. CONSTITUTION:A liq. mixture is produced with 100 pts.wt. of propylene glycol as the binder, one equivalent of isophorone diisocyanate as the curing agent, two equivalents of trimethylolpropane as the additive and 20 pts.wt. of diethyl terephthalate as the plasticizer. Twenty pts.wt. of the mixture is kneaded with 80wt.% of the solid powder of ammonium perchlorate, and 1-5wt.% of an increase of the carbon powder having <50mu average particle diameter is added to 100 pts.wt. of the kneaded material and sufficiently mixed. The mixture is heated to about 60 deg.C and cured to produce the solid propellant. The combustion of the propellant is continued at 60-70atm or lower and stopped above that pressure, and the propellant is controllably ignited and extinguished by the change of pressure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid propellant composition capable of easily controlling ignition and extinguishing.

[0002]

2. Description of the Related Art Solid propellants are currently widely used in the fields of civilian use and military use, and have been able to easily control combustion to meet various requirements.

[0003]

However, in controlling the combustion of solid propellant, it is easy to control the combustion rate by changing the composition and the thrust per time by changing the form factor. On the other hand, like liquid propellants, it was not possible to ignite, extinguish, or re-ignite, which was a problem because it was restricted in operation.

[0004]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies in consideration of the above problems, and as a result, due to an increase in pressure,
The inventors have found a solid propellant composition capable of stopping combustion and completed the present invention. That is, the present invention is a combustion control propellant characterized in that solid carbon is contained in a solid propellant whose binder main component is polypropylene glycol.

The present invention will be described below. The polypropylene glycol used as the main component of the binder in the present invention may be a commercially available product, which is liquid at room temperature (molecular weight of 1000 to 3000) and has a hydroxyl group at the end in order to cure it by the following method by heating. Those are preferable.

The combustion control propellant of the present invention comprises a solid substance consisting of an oxidizer component and solid carbon as powder, a polypropylene glycol and a curing agent having an isocyanate group, and optionally a cross-linking agent, a plasticizer and the like. It is obtained by mixing the following liquid substance and curing by heating. As the curing agent, cross-linking agent, and plasticizer used above, general ones can be widely used and are not limited in any way.

As solid carbon, it is necessary to disperse it uniformly in the propellant, and it is desirable that it be fine particles.
At times, the average particle size is preferably 50 μm or less. The fixed carbon content needs to be contained in the solid propellant in an amount of 1 to 5% by weight. If it is 1% by weight or less, it is difficult to obtain the intended effect, and if it is 5% by weight or more, it becomes a liquid component. It becomes difficult to mix, which is not preferable.

Ammonium perchlorate is particularly preferable as the oxidizing agent, but an oxidizing agent known for solid propellants can be used. The combustion control propellant composition of the present invention obtained by the above method has a feature that it burns at a low pressure, but stops when the pressure rises to 70 atm or higher, and thus can be used as follows. is there.

Since the internal pressure of the rocket motor can be adjusted by the opening ratio of the nozzle, if the ignition ratio is set to a predetermined pressure by igniting under normal pressure,
After any time, the combustion can be stopped. If re-addition is performed from that portion, an arbitrary combustion pattern can be taken. As a re-ignition method, an ignition tool may be set at a predetermined position in advance.

[0010]

EXAMPLES The present invention will be described below with reference to examples.

[0011]

Example 1 Polypropylene glycol (molecular weight 300
0) With respect to 100 parts by weight, 1 equivalent of isophorone diisocyanate as a curing agent, 2 equivalents of trimethylolpropane as a cross-linking agent and 2 equivalents of diethyl phthalate as a plasticizer.
80 parts by weight of ammonium perchlorate having an average particle size of 200 μ is added to 20 parts by weight of a liquid material obtained by mixing 0 parts by weight, and further 100 parts by weight in total of the above solid carbon (average particle size of about 5 parts).
μ) 3 parts by weight (outer ratio) are added and mixed, and heated (60 ° C., 7
Then, a predetermined cured product was obtained.

The combustion state was investigated by the following method using the main cured product (solid propellant). External diameter of solid propellant 7 mm
A sample was prepared by cutting out into a cylinder with φ and a length of 10 cm, forming a resin layer (combustion control layer) with a thickness of about 2 mm on the cylindrical side surface (circumferential surface). Such samples are commonly referred to as propellant strands. A fuse wire for ignition was passed through the strand propellant at a position approximately 1 cm from the upper portion, and a fuse wire at a position 3 cm and 8 cm from the upper portion. Strand propellant was ignited by the fuse wire for ignition about 1 cm from the upper part, burned downward, and the time difference between the fuse wires of the lower two (3 cm and 8 cm from the upper part) was cut. Then, the combustion speed is defined as a value obtained by dividing 5 cm). When performing this measurement under pressure, use a strand combustor in which a combustion container and a pressure accumulator having a sufficient capacity to maintain a constant pressure during combustion of the strand propellant are connected, and the strand propellant is stored in the combustion container. It may be set, pressurized to a predetermined pressure with nitrogen gas, and then ignited.

As a result of examination by this method, the following was found out. With this composition, it was found that the combustion continued at 60 atmospheric pressure or less, and the fire extinguished after ignition at around 70 atmospheric pressure or more. About 5 cm from the ignition position when the fire is extinguished
It was burning to the vicinity.

[0014]

Comparative Example 1 The above composition excluding solid carbon is
It was confirmed that combustion continued steadily even at 70 atmospheres or higher.

[0015]

As described above, the present invention provides a solid propellant capable of stopping and reigniting combustion by increasing the pressure, thereby expanding the operating range of a rocket motor and utilizing it as a gas generator. Etc. have great advantages.

Claims (3)

[Claims] 1. A combustion control propellant composition, characterized in that solid carbon is contained in a solid propellant whose binder main component is polypropylene glycol. 2. The combustion control propellant composition according to claim 1, wherein the solid propellant contains 1 to 5% by weight of solid carbon. 3. The combustion control propellant composition according to claim 1, wherein the propellant main oxidizing agent is ammonium perchlorate.