JPS6168383A - Composite solid propellant - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention relates to a composite solid propellant, and more specifically, the present invention relates to a composite solid propellant, in which the main component of the binder is polybutadiene (I (TPB)) with hydroxyl groups at both ends, The present invention relates to a composite solid propellant containing ammonium perchlorate as an oxidizing agent with improved physical properties.

(Prior Art) Composite solid propellants have a composition mainly composed of an oxidizing agent and a binder, with metal powder added as a combustion improver if necessary, and have excellent combustion characteristics and Due to its physical properties, it is widely used as a propellant for high-performance rocket motors. A typical example is a castable propellant that uses granular or powdered ammonium perchlorate as an oxidizing agent, aluminum powder as a combustion improver, and a polybutadiene-based binder. There is.

The base materials for the above-mentioned polybutadiene-based binders have conventionally been butadiene-acrylic acid copolymer (PBAA), butadiene-acrylic acid-acryloni) IJ terpolymer (PBAN), and polybutadiene with carboxyl groups at both ends (CTPB). ) have been used. However, in the case of high-performance propellants with a binder content of 10 to 12% by weight (i.e., high solid content), the viscosity of the prepolymer is relatively high, so the viscosity of the propellant slurry is high and Hikoshiki However, there were problems such as it was not easy to manufacture and the propellant itself changed significantly over time.

In order to solve these problems, a propellant (HTPB propellant) was developed which is based on HTPB and has a binder containing a diincyanate compound as a hardening agent.

Since the HTPB prepolymer in this propellant has a low viscosity, the amount of binder is reduced to 10 to 12% by weight as described above.
This made it possible to easily produce propellants with improved specific impulse.

In addition, since a diisocyanate compound is used as a curing agent, this compound reacts with the hydroxyl group of the HTPB prepolymer to form a strong and stable urethane bond, resulting in crosslinking. It also has excellent properties and stability over time.

Because of these advantages, HTPB propellant is becoming the mainstream of composite solid propellants as a high-performance propellant to replace conventional propellants such as CTPB propellant.

In this HTPB propellant, the binder is H as mentioned above.
It is composed of a TPB prepolymer and a diisocyanate compound, and particles of ammonium perchlorate or the like are used as the oxidizing agent5. That is, particles of ammonium perchlorate or the like are dispersed in a binder, which is a matrix. However, in this ITPB propellant, a binder is required because the adhesiveness between the binder and the oxidizer particles is poor.

Since the binder has a great effect on the adhesion between the two, which in turn influences the physical properties of the propellant, the selection of the binder is an important means of improving the physical properties.

As such a binder, tris-1 (2-methylaziridinyl) phosphine oxide (MAPO
), reaction product of 2 moles of MAPo, 0.7 moles of adipic acid and 0.3 moles of tartaric acid (MT-4), bisisophthaloyl-1-(2methyl)aziridine (HX-752,
5M) etc. are well known, and as a composite system of these, MT
A mixture of HX-4 and HX-752 and 2.2'-(?L-butylimino)jetanol (BIDE) is disclosed in U.S. Pat.
09089! , in the specification of JP-A-54-8401, a mixture of aziridine polyester and amine polyester is disclosed.
It is disclosed in Publication No. 6.

However, these binders have the following drawbacks.

Propellants using MAPO alone as a binder have particularly low elongation.

MT-4 has a short shelf life at room temperature, and propellants using it have poor aging characteristics, such as a decrease in tensile strength over time.

HX-752 has a short shelf life at room temperature, and propellants using it have poor physical properties, particularly poor aging properties such as decreased elongation, increased tensile strength over time, and decreased elongation.

MT-4 disclosed in the US patent specification is -752 and B
Similarly to MT-4 and HX-752, the mixture with IDE has a short shelf life at room temperature, and furthermore, the amount added to the binder is relatively large. That is, it is necessary to add about 3% of it as a mixture to the binder.

After 16,076 months, the tensile strength and elongation were lower than the initial level, and the aging properties at high temperatures were poor.

Furthermore, the mixture of aziridine polyester and amine polyester disclosed in JP-A-54-84C116 has poor physical properties (low elongation) and poor aging properties (
elongation decreases over time).

(Problems to be Solved by the Invention) The present inventors have solved the drawbacks of these conventionally used binders, have a long life at room temperature, and have improved the physical properties and aging characteristics of the propellant itself using these binders. As a result of research, the present invention was completed with the aim of obtaining a binder that can be used.

(Means and effects for solving the problems) That is, the present invention provides a composite solid propellant containing a binder mainly composed of HTPB prepolymer and ammonium perchlorate. MAPO and BID as agents
It is a composite solid propellant containing E.

In the present invention, MAPO is added as a binder in the binder.
．． In the range of 3 to 1.5% by weight, and BIDE of 0.1 to 1.5% by weight.
The content is preferably within a range of 0.5% by weight. MAP
If the O content in the binder is less than 0.6% by weight, the tensile strength of the propellant tends to decrease, and if it exceeds 1.5% by weight, the elongation tends to decrease as well. There is. More preferably, it is in the range of 0.4 to 1.0% by weight.

Similarly, if the content of EIDE in the binder is less than 0.1% by weight, elongation tends to decrease in terms of propellant properties, and if it exceeds 0.5% by weight, the tensile strength similarly decreases. This tendency causes problems such as reeds, lumps, and poor fluidity of the uncured propellant slurry, making it difficult to cast. More preferably, it is 0.2 to 0.5% by weight. Also MAP
O and BIDE can be used in a premixed manner, or they can be used separately.

Combinations other than MAPO and BIDE as binders cannot achieve the object of the present invention.

As the polybutadiene prepolymer (HTPB prepolymer) having hydroxyl groups at both ends used in the present invention, for example, Po1y bd (trade name, manufactured by Alco Chemical Company, USA) is used.
There are R-45M and poly bd R-45HT. The former R-45M is widely used as a propellant.

Poly bd R-45M has a number average molecular weight of 220
0 to 5400, hydroxyl value is 0.7 to 0.8 mm/f, 1,4 cis is 10 to 30%, 1.4 trans is 50 to 70, and 1,2 vinyl is It has a microstructure of 10 to 50 inches.

In addition to the above-mentioned binder and HTPB prepolymer, the materials constituting the binder used in the present invention include a curing agent,
Furthermore, additives such as plasticizers and anti-aging agents are included as necessary.

Examples of curing agents include infron diisocyanate (IPDI), hexamethylene diisocyanate (T(
Diisocyanate compounds such as MDI) and ditolyl diisocyanate (DDI) are 1), preferably IPDI. The blending amount of the diincyanate curing agent is determined by the equivalent ratio of isocyanate groups (NCO) to hydroxyl groups (OH) in the HTPB polymer as NC010H.
10H = dust in the range of 0.6 to 1.2, preferably 0
．． It is in the range of 7 to 1.0.

The plasticizer is usually dioctyl adipate (DOA).
, dioctyl sebacate (DoS), diisodecyl adipate (DIDA) and isodecyl pelagone) (I
DP) etc.

Examples of anti-aging agents include 2,2'-methylene-bis(4-methyl-6-tert-butylphenol), phenyl-β-naphthylamine, and a reaction product of hydiphenylamine with acetone (manufactured by Seiko Kagaku Co., Ltd., trade name: Non). Flex BA) etc. are used.

When producing a composite solid propellant, the above binder is usually used in an amount of 10 to 50% by weight, an oxidizing agent is added thereto,
Combustion aids and combustion catalysts are also added to adjust performance as necessary. Ammonium perchlorate (AP), cyclotetramethylenetetranitramine (HMX), cyclotrimethylenetrinitramine (RDX), etc. are usually used as oxidizing agents, and powders of aluminum, boron, etc. are used as combustion improvers. However, as a combustion catalyst, iron oxide 0
'$tos), ferrocene derivatives, carborane derivatives, etc. are used.

The oxidizing agent of the solid propellant of the present invention is ammonium perchlorate, but it does not necessarily have to be the sole oxidizing agent.

However, it is necessary to contain at least 50% by weight,
The content is preferably 60% by weight or more.

The reason is that the binder in the present invention improves the adhesion between ammonium perchlorate and the binder, but if the amount of ammonium perchlorate is small, that is, less than 50% by weight, the effect is small. , as a result of which the physical properties of the propellant deteriorate (lower tensile strength and elongation).

The composite solid propellant of the present invention can be obtained using the above-mentioned components and by a conventional manufacturing method.

(Effects of the Invention) The composite solid propellant of the present invention obtained in this way has significantly improved physical properties compared to propellants using conventionally known binders, and in particular, has improved elongation at the same tensile strength. Furthermore, it has good aging characteristics with very little change in physical properties even after accelerated aging tests at high temperatures.

In addition, in the present invention, the binder used is stable,
It has the advantage of good storage stability and handling properties, and is effective even when added in a small amount.

(Example) Hereinafter, the present invention will be specifically explained with reference to Examples.

Example 1 First, 91.4 parts by weight of HTPB prepolymer (trade name: Poty bd R-45M, manufactured by Alco Chemical Co., Ltd.) and 2,2'-methylene-bis(4-methyl-6-turn liptylphenol), which is an anti-aging agent, were added. ') A total of 0.9 parts by weight was added and vacuum mixed at 70°C for 50 minutes. Next, after bringing the temperature to normal pressure and room temperature, tris-1 (2-methylaziridinyl)phosphine oxide (MAPO) was added as a binder.
) 0.5 parts by weight and 0.1 parts by weight of 2.2'-(butylimino)jetanol (BIDI),
Mixed until homogeneous.

Next, the curing agent isophorone diisocyanate) (
After mixing, a predetermined amount of aluminum powder was added and mixed until it became a paste.

Next, a predetermined amount of ammonium perchlorate, which is an oxidizing agent, is charged, heated to 60 ° C., mixed in a vacuum for 40 minutes, and the slurry-like mixture is poured into a predetermined molding container under vacuum.
After defoaming, the mixture was cured at 60° C. for 7 days to obtain a propellant. Regarding the slurry-like mixture immediately after vacuum mixing, Part 6
The viscosity at 0°C was measured using an E-type viscometer. Table 1 shows the binder composition and propellant composition, and Table 2 shows the viscosity.

Further, using the above propellant, tensile properties, aging properties and combustion properties were measured by the methods shown below, and the obtained results are shown in Table 2.

[Tensile properties]

A tensile test piece specified by the Propellant Materials Conference was prepared from the above propellant, and the test temperature was 20 WrM/min at a tensile speed of 50 WrM/min.
A tensile test was conducted at .degree. C. and -50.degree. C., and the maximum stress, strain (elongation) at the maximum stress, and elastic modulus were determined.

[Aging characteristics]

The propellant block after hardening was placed in a constant temperature bath at 60°C for 45 minutes.
After that, the same test as for the tensile properties described above was conducted.

[Combustion characteristics]

A propellant with dimensions of 7 x 7 x 130 rectangular prisms was prepared, and a strand test piece was prepared with the sides covered with melamine paint, and a pressure of 50 Kff/- was prepared using an ordinary Crawford type strand combustion test device. The burning rate under td was measured.

Examples 2 to 15 Propellants of the present invention were prepared in the same manner as in Example 1 by changing the binder composition and changing the weight proportions of aluminum and ammonium perchlorate, which is an oxidizing agent. Slurry viscosity, tensile strength, aging characteristics, and combustion characteristics were measured in exactly the same manner as in Example 1. The propellant composition is shown in Table 1, and the slurry viscosity, tensile strength, aging characteristics, and combustion characteristics are shown in Table 2. For Examples 6 and 7, especially regarding aging characteristics, the samples were placed in a constant temperature bath at 70°C for 6 months. We also talked about things.

The total length of the tensile test specified by the membership fee promotion drug-related meeting is 1251! II, the leg ends are 25 mm wide, and between the two ends there is a central straight section with a length of 5 Qm and a width of 10 mm, and the thickness is 10+ m+.

Each symbol in the binder composition and propellant composition in Table 1 represents the following substance.

I (TPB prepolymer: Poly bd R-4
5M (manufactured by Alcokercal) IPDI: Isophorone diisocyanate MAPO:) Lis 1 (2methylaziridinyl)phosphine oxide EIDE: 2,2'-(fi-butylimino)jetanol DOA Nidioctyl adipate AQ-2246
: 2,2'-methylene-bis(4methyl-6-tert-butylphenol) 豫■ Nidichlotetramethylenetetranitramine RDX Nidichlotrimethylenetrinitramine Comparative Examples 1 to 15 By changing the composition of the binder, Propellants were prepared in exactly the same manner as in Example 1 by changing the blending composition of the binder and propellant, and the slurry viscosity, tensile strength, aging characteristics, and combustion characteristics were measured in exactly the same manner. Regarding Comparative Example 6, an aging test was conducted at 70° C. for 6 months.

The composition is shown in Table 3, and the results of various measurements are shown in Table 4.

The names of substances with symbols not in Table 1 in each formulation in Table 5 are shown below.

MT-4: Reaction product of 2 moles of MAPo, 0.7 moles of adipic acid, and 0.3 moles of tartaric acid HX-752: Bisisophthaloyl-1-(2-methyl)
Aziridine (manufactured by 5M) N-8: Reaction product of N-methyljetanolamine and separenic acid Examples 1 to 5 and Comparative Examples 1 and 2 have a binder amount of 14% by weight.
Examples 6 and 7 and Comparative Examples 3 to 7 are propellants with a binder content of 12% by weight.

Among the tensile strength characteristics of propellants, tensile strength (stress) and elongation (strain) generally have an inverse relationship, and as one increases, the other tends to decrease. Therefore, when comparing tensile strengths, it is desirable to make the tensile strengths the same and compare the magnitude of elongation. From this point of view, Examples 1 to t5
and Comparative Example 1.2, and Example 6.7 and Comparative Example 3, 4゜5
．． 7 clearly shows that the propellant of the present invention exhibits good physical properties and aging characteristics. That is, in terms of physical properties, the propellant of the present invention has a strain at maximum stress of
significantly larger. In addition, regarding aging characteristics, 4 at 60℃
It can be seen that the tensile strength after holding for 5 days shows little change compared to the initial value, and there is no decrease in elongation (strain).

Furthermore, in Comparative Example 6, the tensile strength after 6 months at 70°C decreased in terms of maximum stress, strain, and elastic modulus, whereas the propellants of the present invention (Examples 6 and 7) showed no change in any of them. It shows good aging characteristics with little or no deterioration.

In Example 8, the amount of binder was reduced to 11% by weight, and in Example 9, the amount of binder was increased to 20% by weight, and no aluminum powder was contained. , Comparative Example 8
As is clear from comparison with No. 9 and No. 9, the propellants of the present invention all exhibit good physical properties and aging characteristics, have low slurry viscosity, and have good manufacturability.

In Examples 10 to 13, in addition to ammonium perchlorate, 1Q to 20% by weight of HMX and RDX were added as oxidizing agents, and if each is compared with Comparative Examples 10 to 13, the results are as follows.
It can be seen that all the propellants of the present invention exhibit good physical aging characteristics.

Procedural corrector (spontaneous) October 25, 1981

Claims (2)

[Claims] (1) In a composite solid propellant containing a binder mainly composed of a polyptadiene prepolymer with hydroxyl groups at both ends and ammonium perchlorate, tris-1 (2-methylaziridinyl) is added as a binder to the binder. phosphine oxide,
A composite solid propellant characterized by containing 2,2'-(n-butylimino)diethanol. (2) The proportion of tris-1(2-methylaziridinyl)phosphine oxide in the binder is 0.3 to 1.5% by weight, and the proportion of 2,2'-(n-butylimino)diethanol is 0.1 to 1.5% by weight. Composite solid propellant according to claim 1, which is 0.5% by weight.