JPH0397687A - Composite solid propellant and production thereof - Google Patents

Abstract

PURPOSE:To increase the combustion rate without accelerating the curing reaction of the propellant by forming iron oxide as an additive to be added as a combustion catalyst for regulation of the combustion rate into a specific bar shape. CONSTITUTION:The bar-shaped iron oxide which has <=1000 ratio of the length to diameter and has <=10mu length and >=0.01mu diameter is added to the composite solid propellant essentially consisting of a binder and oxidizing agent in the production of this propellent. The viscosity of the propellant is low and the pot life thereof increases in this way and, therefore, the productivity is improved. The productivity of the propellent decreases if the above-mentioned ratio of the length to the diameter is too large or if the length is too large. There is a tendency to a decrease in the increase rate of the combustion rate if the above-mentioned ratio is too small or if the length is too small. The resulted propellant is greatly increased in the combustion rate as compared to the propellant contg. the granular iron oxide. The amt. of the propellant to be used is consequently decreased.

Description

[Detailed Description of the Invention] Industrial Application Fields The present invention relates to a composite solid propellant and a method for producing the solid propellant, and more specifically, a composite solid propellant having a high burning rate and excellent manufacturability. This article relates to propellants and their manufacturing methods.

<Prior art> Composite solid propellants have a composition whose main components are an oxidizing agent and a binder that serves as a fuel and a binder, and usually has a composition in which metal powder is added as a combustion improver to improve black firing performance. Due to its excellent combustion and physical properties, it is widely used as a propellant for high-performance rocket engines.

A typical example is a castable propellant consisting of granular or powdered ammonium perchlorate as an oxidizing agent, aluminum as a combustion improver, and a polybutadiene-based binder.

Furthermore, in order to improve the performance of propellants in recent years, a wide range of combustion speed adjustment is required, and a combustion catalyst is added as an additive for this purpose.

Particularly in recent years, there has been a strong demand for higher combustion rates.

The most widely known additive for this purpose is granular iron oxide (Japanese Patent Laid-Open No. 109889/1989).

<Problem to be solved by the invention> However, conventional composite propellants using granular iron oxide as a combustion catalyst accelerate the curing reaction of the propellant, that is, shorten the pot life, due to the influence of the iron content. In addition, there was a problem that the productivity was significantly reduced (Industrial Explosives Association Journal Vol. 49, 119 (1)
98B)). Furthermore, as the amount of combustion catalyst added increases to increase the combustion rate, the specific impulse of the propellant decreases, so the required combustion rate can be obtained with a small amount of addition, that is, the development of a combustion catalyst with a large catalytic effect. was desired.

As a result of intensive research in consideration of the above-mentioned problems, the present inventors found that using a specific iron oxide does not accelerate the hardening reaction of the propellant, and the burning rate is also higher than that of conventional ones. As a result, the present invention was completed.

<Means for Solving the Problems> That is, the present invention provides a composite solid propellant containing a binder and an oxidizing agent as main components, which has a length-to-diameter ratio of 1000 or less, a length of 10 μm or less, and a diameter of 10 μm or less. In the method for producing a composite solid propellant characterized by containing rod-shaped iron oxide having a diameter of 0.0 ILLm or more and a cast-type composite propellant containing iron oxide, the iron oxide has a length to diameter ratio of 1000 or less. , and the length is I
Oμm or less, diameter is 0. The present invention relates to a method for producing a composite solid propellant, which is characterized by using rod-shaped iron oxide with a diameter of 1 μm or more.

The iron oxide used in the present invention is characterized by being rod-shaped, with a length-to-diameter ratio of 2 to 1000, a length of about 5 to 10 μm, and a diameter of about 0.01 to 2 μm. Preferably, the ratio is 5 to 40 and the length is 0.8 to 40.
2μm, diameter 0. 05 ~0. It is about 15 μm. If the ratio is too large or the length is too long, the productivity of the propellant will decrease, and if the ratio is too small,
Alternatively, if the length is too short, the rate of increase in combustion rate tends to decrease.

Commercially available iron oxides that can be used in the present invention include, for example, Kanto Denka Kogyo Co., Ltd. (trade name: Pferrox 2).
228, Pferrox 2228HC. Pferr
ox 2380, Pferrox No. 00.38, etc.),
Manufactured by Toda Kogyo Co., Ltd. (product name: YELLOW48). Manufactured by Titan Kogyo Co., Ltd. (Product name: R-TH, R-1107, R-51
6L, etc.), manufactured by Ishihara Sangyo Co., Ltd. (product name, FS-1300,
FS-1500, FS-1600. FS-17
50 etc.).

Rod-shaped iron oxides containing several percent of other metals, such as cobalt, can also be used in the present invention. Such examples include Kanto Denka Kogyo Co., Ltd. (product name: Pferrico 2050, Pferrico
2560. Pferrico 0070. Pf
errico2566, Pfqrrico 357Q
etc.), manufactured by Ishihara Sangyo Co., Ltd. (product name, CS-3501.C)
S-5250, CS-7200, CS-7400,
CS-7550, CS-7650, CS-775
0, CS-7850, etc.).

The ratio of iron oxide added to the propellant is usually 0.0% relative to other components. Ol to 10% by weight, more preferably,
It is 0.05 to 5% by weight. If this ratio is too low,
If the effect of increasing the combustion speed is too small or too large, the rate of increase in the combustion speed relative to the amount of iron oxide added tends to be small, and the specific impulse of the propellant tends to decrease.

The components of the composite solid propellant of the present invention are known and will be described below.

As the oxidizing agent, perchlorates such as ammonium perchlorate (AP) conventionally used in composite propellants, ammonium nitrate (AN), cyclotetramethylenetetranitramine (HMX), etc. are used as necessary. Cyclotrimethylenetrinitramine (RDX) or the like may also be used.

As the binder, all binders conventionally used in composite propellants can be used. Particularly preferable binders from the viewpoint of combustion characteristics are hydroxyl-terminated polybutadiene (HTPB) and carboxyl-terminated polybutadiene (
CTPB) and aliphatic polyethers with terminal hydroxyl groups.

The binder includes influorone diisocyanate (I
PDI), hexamethylene diisocyanate (HMDI)
), and if necessary, dioctyl adipate (DOA). Dioctinorecebacate (DOS)
7 stones such as Qi i1 are also used.

Further, in order to improve the adhesion between the oxidizing agent and the binder, tris(2methylaziridinyl)phosphine oxide (MAPO). 02 moles of MAP and 0.0 moles of adivic acid.
Reaction product of 7 mol and 0.3 mol of tartaric acid (MT-4)
．． Bisisophthaloyl-1-(2-methyl)aziridine (
A binder such as HX-752 (manufactured by Snow-M) may also be used as necessary. Moreover, an anti-aging agent can also be used if necessary.

As the combustion improver, for example, aluminum, boron, etc. are usually used.

The content of each of the above components in the composite propellant is usually:
The oxidizing agent is 50 to 85% by weight, the binder is 10 to 30% by weight, and the combustion improver is ○ to 20% by weight.

The method for manufacturing the composite propellant of the present invention follows conventional procedures, except for using iron oxide rods. Note that, for example, when using auxiliary combustion cutting, the rod-shaped iron oxide can be added in the process of adding the auxiliary agent, or after that. Alternatively, if a plasticizer is used, it can be added to the binder in advance and made into a paste. may also be used.

<Effects of the Invention> Compared to the conventional method using granular iron oxide, the method for producing a composite propellant using rod-shaped iron oxide of the present invention has a lower propellant viscosity and a longer pot life, which improves productivity. Are better.

Furthermore, the composite propellant containing rod-shaped iron oxide as a combustion catalyst of the present invention is characterized in that the combustion performance, particularly the combustion speed, can be significantly increased compared to a propellant containing granular iron oxide. Therefore, compared to conventional propellants, it is possible to use a smaller amount of propellant, and therefore it also has the advantage of less reduction in specific impulse.

<Examples> The present invention will be specifically explained below using Examples and Comparative Examples.

Example 1 Binder, hydroxyl-terminated polybutadiene (HTPB Brevolimer; r Poly bdR-4 manufactured by Sartomer Co., Ltd.)
5M J) 0.20 parts by weight of tris(2-methylaziridinyl)phosphine oxide (rMAPOJ manufactured by Alcinco) as a binder was added to 13.32 parts by weight and mixed, and then a combustion improver was added to the mixture. 18.0 parts by weight of aluminum powder with an average particle size of 10 μm and 0.5 parts by weight of rod-shaped iron oxide (manufactured by Titan Kogyo Co., Ltd.) with a length of about 0.8 μm and a diameter of about 0.08 μm as a combustion catalyst.
A paste-like mixture was obtained by mixing for 0 minutes. Next, the curing agent isophorone diisocyanate (I) is added to this mixture.
0.48 parts by weight of PDI) was added and mixed under vacuum for 10 minutes. Next, ammonium perchlorate, which is an oxidizing agent, was added to 6
8 parts by weight were charged, heated to 60° C., and vacuum mixed for 40 minutes to obtain a slurry-like mixture. This mixture was poured into a predetermined molding container under vacuum, and after vacuum degassing, it was cured at 60° C. for 7 days to obtain a propellant. For the slurry-like mixture immediately after vacuum mixing, the slurry viscosity at 60° C. was measured using an E-type viscometer, and the pot life was also measured. Pot life measurement is a method of measuring the time it takes for the propellant viscosity to reach 40 kV at 60°C, and is used to evaluate the manufacturability of the propellant, and is generally used for large rocket propellants. ,
A pot life of 6 hours or more is required. Table 1 shows the composition, viscosity, and pot life of this propellant.

A combustion test was conducted using this propellant using the method shown below. That is, the diameter is 80mm, the inner diameter is 40mm, and the length is 140mm.
A cylindrical propellant was prepared, and the outer circumferential side surface of the propellant was coated with epoxy resin to prepare a drug substance. This drug substance was loaded into a standard rocket motor chamber with an inner diameter of 84 mm, and the combustion pressure was 5.
The nozzle throat diameter was adjusted to 0 kgf/c+n'', and a combustion test was conducted using a combustion stand device for small rocket motors to measure the combustion speed of the propellant.The measurement results are shown in Table 1. .Furthermore, Table 1 also shows the specific impulse calculated using the usual calculation method for this propellant combination.

Comparative Example 1 A propellant was produced according to Example 1 except that rod-shaped iron oxide was not added.

In addition, the slurry viscosity, pot life, and burning rate were measured in the same direction as in Example 1. Moreover, the specific impulse was also calculated in the same way. These results are shown in Table 1.

Examples 2 to 9 Except for changing the amount and type of rod-shaped iron oxide as shown in Table 1,
Each propellant was manufactured using the formulation shown in Table 1.

For each propellant, slurry viscosity, pot life, and burn rate were measured in the same manner as in Example 1. Further, the specific impulse was also calculated using the same method. These results are shown in Table 1.

Comparative Examples 2 to 7 Each propellant was manufactured using the formulation shown in Table 1, except that the rod-shaped iron oxide was replaced with the conventional granular iron oxide.

For each propellant, slurry viscosity, pot life, and burning rate were measured in the same manner as in Example 1. However, the compositions of Comparative Examples 4 and 5 were too hard to measure slurry viscosity and pot life.

The specific impulse was also calculated in the same manner as in Example 1 for each blending composition. These results are shown in Table 1.

Each symbol in the propellant composition in Table 1 indicates the following substance.

HTPB Brevolimer: Poly bd R-45M
(Manufactured by Sartomer) IPDI: Isophorone diisocyanate MAPO:}
Lithium 1 (2-methylaziridinyl)phosphine oxide I-shaped iron oxide 1: Length approx. 0.8 μm x diameter approx. 0.08 μm
(manufactured by Monoku Titanium Industries Co., Ltd., trade name 8516L") Rod-shaped iron oxide 2: about 0.4 μm in length x about 0.06 μm in diameter (manufactured by Kanto Denka Kogyo Co., Ltd., trade name Pferrox 222g)
Rod-shaped iron oxide 3: About 0.7 μm in length x about 0.1 μm in diameter (manufactured by Toda Kogyo Co., Ltd., product name YELLOW48) Rod-shaped iron oxide 4: About 0.3 μm in length x about 0.03 μm in diameter (Ishihara Granular iron oxide (manufactured by Sangyo Co., Ltd., trade name FS-1500): average particle size of about 0.1 μm (manufactured by Toho Pigment Co., Ltd., trade name FRI)
I) In Examples 1 to 6 and Comparative Examples 1 to 4, the amount of binder was 14 parts by weight,
The propellant contains 18 parts by weight and 68 parts by weight of a combustion improver and an oxidizing agent, respectively, and 0 to 5.0 parts by weight of iron oxide is added thereto. The burning speed of propellant is in Examples 2 to 6 and Comparative Examples 1 to 4.
It is clearly seen that the propellant of the present invention has an increased burning rate. In addition, in Comparative Examples 1 to 5, the propellant slurry viscosity increased with the amount of granular iron oxide added,
Moreover, the pot life is shortened, and at 3.0 parts by weight or more, both the slurry viscosity and the pot life become hard to the point that they cannot be measured. On the other hand, in the case of the rod-shaped iron oxide of the present invention, both the slurry viscosity and the pot life show very little change, indicating that it has good manufacturability.

In Examples 7 and 8 and Comparative Example 5.6, the amount of binder, the amount of oxidizing agent,
Although the amount of combustion improver was changed, it can be seen that all the propellants of the present invention show good manufacturability and also have a higher burning rate than the conventional ones.

Claims (2)

[Claims] (1) A composite solid propellant containing a binder and an oxidizing agent as main components, containing rod-shaped iron oxide with a length-to-diameter ratio of 1000 or less, a length of 10 μm or less, and a diameter of 0.01 μm or more. A composite solid propellant characterized by: (2) In the method for manufacturing a cast-type composite propellant containing iron oxide, rod-shaped iron oxide with a length-to-diameter ratio of 1000 or less, a length of 10 μm or less, and a diameter of 0.01 μm or more is used. A method for producing a composite solid propellant, characterized by: