JP3140533B2 - High energy binder-based composite propellants - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

This invention relates to composite propellants for rocket motors. More specifically, a high-energy binder-based composite propellant using a binder containing a specific polyether having an azidomethyl group as a main component as a binder of a composite propellant comprising an oxidizing agent, a binder, an auxiliary agent, a combustion catalyst, and the like. It is about medicine.

[0002]

2. Description of the Related Art A composite propellant comprising an oxidizing agent and a binder as main components, and if necessary, an auxiliary agent, a combustion catalyst, an antioxidant, etc., has a high propellant property due to its excellent combustion characteristics and mechanical characteristics. Widely used as a propellant for high performance rocket motors. Among these, as a main component of the binder, terminal hydroxyl group polybutadiene (HTPB), terminal carboxyl group polybutadiene (CTPB) and the like are mainly used. Kaisho 63-248791
No.), 3,3-bisazidomethylmethyloxetane / tetrahydrofuran copolymer (BAMO / THF copolymer)
(Japanese Patent Application Laid-Open No. 3-239178) are known.

[0003]

However, conventional composite propellants, especially glycidyl azide polymers
In high-energy binder-based composite propellants containing (GAP) as the main component of the binder, the hydroxyl groups at both ends of GAP are almost secondary, so the reactivity is extremely poor, and it takes a long time to cure, and there is a problem in manufacturability. was there. Further, a large amount of a curing catalyst is mixed in order to enhance the reactivity, which causes a problem that the aging resistance of the propellant itself is reduced. Therefore, an object of the present invention is to provide a high-energy composite propellant which has solved the above-mentioned problems.

[0004]

Means for Solving the Problems The present inventors have studied a method of modifying a terminal secondary hydroxyl group into a primary hydroxyl group in order to increase the reactivity of a conventional glycidyl azide polymer having both terminal hydroxyl groups, A patent application was filed for a glycidyl azide polymer having both ends modified with a hydroxyl group.
257653). Further, the present inventors diligently studied a composite propellant containing the glycidyl azide polymer modified at both ends as a main component of a binder, and completed the present invention.

That is, according to the present invention, the main component of the binder is
In a high energy binder-based composite propellant which is a terminal hydroxyl aliphatic polyether having an azidomethyl group in a side chain, the terminal hydroxyl aliphatic polyether is
It is intended to provide a high energy binder-based composite propellant represented by the general formula (I).

[0006]

Embedded image

Where q is a positive number in the range of 5-35, p and
r is a positive number in the ranges of 1 to 3, R is -CH ₂ CH ₂ -, - C
Represents an alkylene group selected from the group consisting of - H ₂ CH ₂ CH ₂ - and _{-CH 2 CH 2 CH 2 CH 2} . The polyether represented by the general formula (I) used in the present invention has a number average molecular weight of 500 to 6000, and particularly preferably 1000 to 1000.
A range of 3000 is preferred. If it is less than 500, the mechanical strength of the propellant becomes small, and if it exceeds 6000, the viscosity becomes extremely high and the productivity of the propellant deteriorates, so none of them can be used.

The binder constituting the composite propellant of the present invention is mainly composed of the polyether represented by the above general formula (I), and other components include hexamethylene diisocyanate (HMDI) and isophorone diisocyanate (IPDI). Curing agents such as triphenylbismuth (TPB), dibutyltin dilaurate (DBTD
L) a curing catalyst, and if necessary, dioctyl adipate (DOA), dibutyl phthalate (DBP),
Bis-2,2-dinitropropyl acetal (BDNP
A) and bis-2,2-dinitropropylformal (BD
A mixture of a plasticizer such as a mixture of NPF), a binder such as a hydantoin compound for enhancing the bonding force with the oxidizing agent particles, and a crosslinking agent such as trimethylolpropane.

[0009] The composite propellant of the present invention contains an oxidizing agent as an essential component in addition to the binder. Examples of the oxidizing agent used in the present invention include nitramine compounds such as ammonium perchlorate (AP), ammonium nitrate (AN), cyclotrimethylenetrinitramine (RDX) and cyclotetramethylenetetranitramine (HMX). A nitramine compound such as RDX or HMX, or a mixture of a nitramine compound with AP, AN, or the like is preferable. In the present invention, the ratio between the oxidizing agent and the binder is 70% by weight.
The range of / 30 to 80/20 is preferred. Further, in addition to the oxidizing agent and the binder component, a propellant such as aluminum powder and a combustion catalyst such as lead citrate and lead stearate can be added to the propellant of the present invention as needed.

[0010]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.

Example 1 A propellant was produced with the composition shown in Table 1 as in Example 1 as follows. First, among the binder components, each component except HMDI as a curing agent was vacuum-mixed at 70 ° C. for 30 minutes.
Note prepolymer used here those represented by the general formula _{(I), R = -CH 2} CH 2 -, p = 1, r = 1, q = 15, were of molecular weight = 1490. Then, at normal pressure and normal temperature, a predetermined amount of HMX was charged, and a predetermined amount of HMDI as a curing agent was further charged.
The slurry mixture was cast into a predetermined container under vacuum, defoamed, and cured at 60 ° C. for 7 days to obtain a propellant. The obtained propellants were evaluated for tensile properties and aging properties by the following methods. Table 1 shows the results.

<Tensile Properties> From the above propellants, a tensile test specimen specified in the propellant drug properties roundtable was prepared, and the tensile speed was 50 mm.
A tensile test was performed at a test temperature of 25 ° C./min to determine the maximum tensile strength (σ _m ) and elongation at break (ε _b ).

<Aging Characteristics> The above-mentioned propellant block was heated to 60 ° C.
Was placed in a constant temperature bath for 4 weeks, and thereafter, the same test as the above tensile properties was performed to determine the strength and elongation.

Example 2 A propellant was prepared in the same manner as in Example 1 using the composition of Example 2 shown in Table 1, and the tensile properties and aging properties were examined in the same manner as in Example 1. The results are shown in Table 1. The prepolymer used here was exactly the same as in Example 1.

Comparative Example 1 A propellant was prepared in the same manner as in Example 1 using the composition of Comparative Example 1 shown in Table 1, and the tensile properties and the aging properties were examined in the same manner as in Example 1. The results are shown in Table 1. Here, the prepolymer used was a glycidyl azide polymer represented by the following structural formula (II). The number of curing days was 10 days.

[0016]

Embedded image

Comparative Example 2 A propellant was prepared in the same manner as in Example 1 with the composition of Comparative Example 2 shown in Table 1, and the tensile properties and aging properties were examined in the same manner as in Example 1. The results are shown in Table 1. The prepolymer and the number of curing days were the same as in Comparative Example 1.

[0018]

[Table 1]

Note) * 1 TMP: Trimethylolpropane * 2 HMDI: Hexamethylene diisocyanate * 3 DBTDL: Dibutyltin dilaurate * 4 DHE: Dihydroxyethyldimethylhydantoin * 5 HMX: Cyclotetramethylenetetranitramine

[0020]

Industrial Applicability The composite propellant of the present invention containing a hydroxyl group-terminated polyether represented by the general formula (I) as a main component of a binder is excellent in shortening of curing days and excellent aging characteristics.

Claims (1)

(57) [Claims] 1. A high-energy binder-based composite propellant, wherein the main component of the binder is a terminal hydroxyl aliphatic polyether having an azidomethyl group in a side chain,
A high-energy binder-based composite propellant, wherein the terminal hydroxyl group aliphatic polyether is represented by the general formula (I). Embedded image (Wherein, q is a positive number in the range of 5 to 35, p and r is a positive number in the range of 1 to 3, respectively, R represents _{-CH 2 CH 2 -, - CH} 2 CH 2 CH 2 - and -CH ₂ represents an alkylene group selected from the group consisting _{of) - CH 2 CH 2 CH 2} .