JPS609998B2 - propellant composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a propellant composition with a reduced pressure index, and particularly to a high specific impulse type propellant composition with a reduced pressure index.

In the field of rocket propellants, which traditionally require smokeless properties, double-base propellants (hereinafter referred to as DB propellants) whose main components are nitrocellulose (hereinafter referred to as NC) and nitroglycerin (hereinafter referred to as NG) are used. has been used.

In recent years, as the required performance has become more sophisticated, high specific impulse propellants,
That is, ammonium perchlorate (hereinafter referred to as AP) is added to the main component.
) and cyclotrimethylenetrinitramine (hereinafter referred to as R
Composite modified double base propellants (hereinafter referred to as CMDB propellants), which mainly contain oxidizing agents such as DX (referred to as DX) and metal powders such as aluminum, have been developed. Composite double base propellant (CD) contains fuel and binder.
B propellant) was developed.

It is known that the relationship between the combustion speed and combustion pressure of these propellants is generally expressed by the following equation.

・r=apn (where r is the fuel velocity, p is the combustion pressure, n is the 0 pressure index, and a is the constant for each propellant) Regarding rocket propellants, it generally depends on the rocket motor design and the fuel From the viewpoint of stability, it is desirable that the pressure index n is small, and in particular, in the case of n, the pressure index n is
The case where <0 is called mesa combustion characteristics, and both of these characteristics are desirable characteristics.

In the DB propellant, as a fuel catalyst that provides such characteristics, organic lead salts such as lead salicylate and lead stearate, lead oxide, and metallic lead are used singly or in combination with the above-mentioned lead compounds or metallic lead and copper salicylate. It is known to be used in a mixture system with organic steel salts such as stearic acid steel, copper compounds such as oxidized steel, metallic steel, etc. (Japanese Patent Publication No. 49-4928). Such known combustion catalysts provide the aforementioned favorable properties in DB propellants with high NC content and relatively low energy production. However, in DB propellants with a high NG content and high specific impulse type propellants such as the CMDB Shishinyaku and CDB Juryaku, the above-mentioned known combustion catalysts are either ineffective in reducing the pressure index n or There were very few. In recent years, there has been a strong demand for fuel catalysts that can act effectively even in such high specific impulse type propellants and can significantly reduce the pressure index n, so the present inventors have conducted extensive research. As a result, we found that a new fuel catalyst consisting of a specific organic steel salt and organic lead salt or inorganic lead met the above requirements, and completed the present invention.
Z: That is, the present invention is a propellant composition containing at least NC and NG, which is characterized by containing copper benzoate and an organic lead salt or an inorganic lead as a fuel catalyst. be. Among the fuel catalysts used in the present invention, organic lead salts Z include:
Examples include lead salicylate, lead stearate, lead resorucinate, lead 2-ethylhexylate, and examples of inorganic lead include lead stannate, lead oxide, and metallic lead.

One or more of these organic lead salts and inorganic lead salts are used in combination with benzoate steel. The total amount of the combustion catalyst used in the present invention is preferably 0.5 to 5% by weight based on the total amount of the propellant composition.
Preferably, it is 2 to 4% by weight.

The amount of copper benzoate is less than 0.22% by weight and the amount of organic lead salt or inorganic lead is 0.22% by weight. If the amount of copper benzoate exceeds 4% by weight and the total amount of fuel catalyst exceeds 5% by weight, the fuel becomes energetically inert. This is not preferable because the number of catalysts increases by 3, which leads to a decrease in specific impulse. In the present invention, in addition to the NC and NG components, plasticizers such as diethyl phthalate, dioctyl phthalate, tributyl phosphate, triacetin, dioctyl adibate, dioctyl sebacate, RDX, cyclotetramethylene, etc. Oxidizing agents such as tetranitramine (HMK), AP, potassium perchlorate,
Metal powder such as aluminum, a stabilizer such as diphenylamiso, a fuel/binder such as polyester containing terminal isocyanate, a swinizing agent, etc. can be combined.

The composition of each of these components can be determined by taking into account combustion performance such as specific impulse, mechanical properties, safety, manufacturability, aging characteristics, etc.

For example, in the case of a high specific impulse type D propellant, NC is 25 to 50% by weight, NG is 40 to 65% by weight, plasticizer and stiffening agent is 3 to 15% by weight, and stabilizer is 0.3 to 5% by weight. %, and in the case of a CMD parent propellant, AP is 0 to 4% by weight, nitramines such as RDX and HMK are 0 to 6% by weight, and aluminum is 0% by weight, based on the total amount of components.
In the case of CDB propellants, 0.3 to 10% by weight of the plasticizer and stiffening agent is added as a fuel and binder. etc., all of which contain 0.5 to 5% by weight of the combustion catalyst specified in the present invention. The propellant composition of the present invention can be produced, for example, by the following method. First, NG, plasticizer, and combustion catalyst are mixed under reduced pressure, and if necessary, oxidizing agent and metal powder are added and mixing is continued.Furthermore, if necessary, fuel/binder is added and mixed, and then stabilizer and fine particles are mixed. After mixing, the slurry of the mixture is poured under reduced pressure and cured under heating to form DB propellant and CM.
Obtain D mother propellant or CD mother propellant.

Next, the present invention will be explained by examples. Note that the percentages in the table are based on weight. Example 1 The formulation composition (OB propellant) of Example 1 shown in Table 1 was manufactured as follows.

NG3200 Diethyl Phthalate (DEP) 800
Add the evening water to the mixture and put it in the mixing machine.

Next, lead salicylate (Pb-
200 g of copper benzoate (Cu-Be) having an average particle size of 10 mm or less were added and mixed under reduced pressure at 30 mm for 20 minutes. After mixing, 200 g of 2-nitrodiphenylamine (2-NDPA) was added, and further finely divided NC5500 was added, and the mixture was mixed under reduced pressure at 400 g for 4 minutes. After mixing, the slurry was cast under reduced pressure and swinized at 5,000 yen for 10 days to obtain a DB propellant. Fifty-five strand samples were prepared from this propellant and a strand test was conducted using the following method. That is, five strands were burned at each point from a pressure of 30 k9·f/ to a pressure of 130 kg·f' in steps of 10 kg·f' in a nitrogen gas atmosphere using a Crochet type strand apparatus, and the combustion speed was determined. Results first
Shown by the solid line in the figure.

In Figure 1, the vertical axis is the combustion rate (r, side/sec
), and the horizontal axis shows the logarithm of the combustion pressure (P, k9·f/). FIG. 1 is a diagram showing the relationship between combustion pressure and combustion speed, in which the average combustion speed at each combustion pressure is plotted. Comparative Example 1 Example 1 except that salicylic acid steel was used instead of copper benzoate
DB propellant was manufactured according to the method.

The same test as in Example 1 was conducted using this propellant, and the results obtained are shown by the broken line in FIG. Example 2
A high specific impulse type DB propellant was manufactured according to Example 1 except that the amounts of ZNC and NG were changed to the ratio shown in Example 2 in Table 1 (the specific impulse in Table 1 is based on NASA's There is a value calculated using a feature number calculation program, and the value is at a combustion pressure of 80k9・f/)
.

The same test as in Example 1 was conducted using the propellant obtained. The results are shown by the solid line in FIG. Comparative Example 2 A high specific impulse type DB propellant was manufactured according to Example 2 except that salicylic acid steel was used instead of copper benzoate.

The same test as in Example 1 was conducted using the obtained propellant. The results are shown by the dashed line in FIG. Example 3 Example 1 was carried out according to Example 1 except that lead salicylate was replaced with lead oxide (P).
High specific impulse type DB of the blended composition of Example 3 shown in the table
Propellant was manufactured.

The same test as in Example 1 was conducted using the obtained propellant. The results are shown by the solid line in FIG. Comparative Example 3 A high specific impulse type DB propellant having the compounding composition of Comparative Example 3 shown in Table 1 was produced according to Example 3 except that copper benzoate was replaced with salicylic acid steel.

The same test as in Example 1 was conducted using the obtained propellant. The results are shown by the dashed line in FIG. Example 4 Compounded composition of Example 4 shown in Table 1 (CMDB Shiishinyaku)
was produced as follows.

NG3920 powder and DEP640 powder were added, and the mixture was heated and put into a mixer. Next, 16M of lead salicylate and 80M of copper benzoate having an average particle size of less than 10Am were added, and the mixture was mixed under reduced pressure at 3,000 °C for 20 minutes.

After mixing, add ROX for 2,000 minutes, mix, and then add 21 ND.
PA was added for 160 minutes, and finely divided NC was further added for 3,040 minutes and mixed at 40q0 for 4 minutes under reduced pressure. After mixing, the slurry was molded under reduced pressure and molded at 5,000 yen for 10 days to obtain an OMDB propellant. The same test as in Example 1 was conducted using this propellant. The results are shown by the solid line in FIG. Comparative Example 4 A CMD parent propellant was produced in the same manner as in Example 4' except that copper benzoate was replaced with steel salicylate.

The same test as in Example 1 was conducted using the obtained propellant. The results are shown by the dashed line in FIG. Example 5 The formulation composition of Example 5 (CDB propellant) shown in Table 1 was manufactured as follows.

Add NG6000 and DEP400 and put it in a mixing machine, then add 200 lead salicylate and 200 copper benzoate with an average particle size of less than loAm and mix it with 30 qo.
Mix for 3 minutes under reduced pressure, then add 400 g of difunctional terminal isocyanate polyester having a molecular weight of 3000 and add 300 g of
After mixing at 40°C for 20 minutes, NDPA 200 and fine particulate NC2600 were added and mixed at 40°C for 40 minutes under reduced pressure.

After mixing, the slurry was molded under reduced pressure and stiffened (hardened) at 50 qC for 10 days to obtain a COB propellant. The same test as in Example 1 was conducted using this propellant. The results are shown by the solid line in FIG. Comparative Example 5 A CDB propellant was produced according to Example 5 except that copper benzoate was replaced with salicylic acid steel.

The same test as in Example 1 was conducted using the obtained propellant. The results are shown by the dashed line in FIG. Table 1 G Note) NC: nitrocellulose, NG: nitroglycerin, DEP: jetyl phthalate, fuel/binder: polyester of bifunctional terminal isocyanate with a molecular weight of 3000, 2-NDPA: 2-nitrodiphenylamine, R
DX: cyclotrimethylene trinitramine, Pb-Sa
: Lead salicylate, Pb○: Lead oxide, Cu [Be: Copper benzoate, Cu-Sa: Copper salicylate *Specific impulse is the value obtained by calculating the number of features The n index shown in the above formula is the combustion pressure p and combustion The following is clear when looking at the slopes of each example (solid line) and comparative example (broken line) in the drawings, as shown by the slope when plotting the speed (r) on the logarithmic axis.

First, Examples 1 to 3 (Comparative Examples 1 to 3) are examples of DB propellants, and as shown in Table 1, Examples 2 and 3 (Comparative Examples 2 and 3) are of high specific impulse type. , Example 1 (Comparative Example 1)
shows an example of a not so high specific impulse type.

In FIG. 1, both Example 1 using the combustion catalyst specified in the present invention and Comparative Example 1 using a known combustion catalyst show mesa combustion characteristics in the high pressure section, but the slope is clearly different from that of Example 1. 1 is larger and has a wider mesa burning area.

Further, in FIG. 2, Example 2 using the combustion catalyst specified in the present invention shows mesa combustion characteristics in the high pressure section, whereas Comparative Example 2 using a known combustion catalyst shows a slope of 3. No decrease is seen. Furthermore, in FIG. 3, although the slope of Comparative Example 3 using a known combustion catalyst is also reduced in the high pressure section, the reduction is more remarkable in Example 3 using the combustion catalyst specified by the present invention. , exhibits mesa combustion characteristics, and the overall slope is lower than that of Comparative Example 3. Fourth
The figure shows an example of a CMD mother propellant, and the slope toward the high pressure part is higher in Example 4 using the combustion catalyst specified by the present invention than in Comparative Example 4 using a known combustion catalyst. is extremely low, indicating almost plateau combustion characteristics.

Also, Figure 5 shows an example of CDB propellant.
It can be seen that the slope of Example 5 using the combustion catalyst specified by the present invention is lower overall and the n-index is lower than that of Comparative Example 5 using a known combustion catalyst.

As is clear from the results of the above examples, the present invention provides a propellant composition in which the n-index is significantly reduced by using a specific combustion catalyst, and particularly in a high specific impulse type propellant composition. , the effect is remarkable.

[Brief explanation of the drawing]

Figures 1 to 3 are combustion pressure-burning rate relationship diagrams for DB propellant, and Figures 4 and 5 are for CMDB propellant and CD propellant.
It is a combustion pressure-combustion speed relation diagram of B propellant. In each figure, solid lines indicate examples and broken lines indicate comparative examples. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5

Claims (1)

[Scope of Claims] 1. A propellant composition containing at least nitrocellulose and nitroglycerin, which further contains copper benzoate and an organic lead salt or an inorganic lead salt. 2. The propellant composition according to claim 1, wherein the total amount of copper benzoate and organic lead salt or inorganic lead is 0.5 to 5% by weight based on the total amount of the propellant composition. 3 The amount of copper benzoate is 0.2 to 4 of the total amount of the propellant composition.
A propellant composition according to claim 2 which is % by weight.