U.S. patent application number 09/764291 was filed with the patent office on 2001-10-18 for ignition elements and finely graduatable ignition components.
Invention is credited to Faber, Gunther, Zollner, Helmut.
Application Number | 20010030007 09/764291 |
Document ID | / |
Family ID | 25940071 |
Filed Date | 2001-10-18 |
United States Patent
Application |
20010030007 |
Kind Code |
A1 |
Faber, Gunther ; et
al. |
October 18, 2001 |
Ignition elements and finely graduatable ignition components
Abstract
An ignition element consists of a combination of first and
second ignition components. The first ignition component contains
at least one primer, at least one heat-conducting additive selected
from the group consisting of zirconium, aluminum, titanium,
ferrotitanium, zirconium boride, zirconium hydride and mixtures
thereof, at least one oxidant and a binder. The second ignition
component contains at least one ingredient that produces hot
reaction particles, an oxidant, and a binder.
Inventors: |
Faber, Gunther; (Siegburg,
DE) ; Zollner, Helmut; (Meerbusch, DE) |
Correspondence
Address: |
ANTONELLI TERRY STOUT AND KRAUS
SUITE 1800
1300 NORTH SEVENTEENTH STREET
ARLINGTON
VA
22209
|
Family ID: |
25940071 |
Appl. No.: |
09/764291 |
Filed: |
January 19, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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09764291 |
Jan 19, 2001 |
|
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08809114 |
Mar 13, 1997 |
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Current U.S.
Class: |
149/2 ;
102/202 |
Current CPC
Class: |
C06C 9/00 20130101; C06B
45/14 20130101; C06C 7/00 20130101 |
Class at
Publication: |
149/2 ;
102/202 |
International
Class: |
F42C 019/08 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 13, 1994 |
DE |
P4432521.5 |
Claims
1. Ignition element consisting of a combination of two ignition
components, characterized in that the first ignition component
(filament component) contains at least one primer, at least one
heat-conducting additive, at least one oxidant, and a binder, and
the second ignition component (power component) contains at least
one ingredient that produces hot reaction particles, an oxidant,
and a binder.
2. Ignition element according to claim 1, characterized in that
lead azide, diazodinitrophenol, silver azide, picrate, or
tricinate, preferably lead picrate, is used as the primer of the
filament component.
3. Ignition element consisting of a combination of two ignition
components, characterized in that the first ignition component
(filament component) contains a heat-conducting primer or a
heat-conducting primer with a heat-conducting additive and a binder
and the second ignition component (power component) contains at
least one ingredient that produces hot reaction particles, an
oxidant, and a binder.
4. Ignition element according to claim 3, characterized in that the
heat-conducting primer used is silver azide.
5. Ignition element according to one of claims 1 to 4,
characterized in that inorganic or organic heat-conducting
substances, preferably metals, metal compounds, or organometallic
compounds are used as the heat-conducting additive.
6. Ignition element according to one of claims 1 to 5,
characterized in that zirconium, aluminum, titanium, ferrotitanium,
metal compounds, preferably zirconium boride or zirconium hydride
or a mixture of these heat-conducting additives is used as the
heat-conducting additive.
7. Ignition element according to one of claims 1 to 6,
characterized in that the ingredient producing the hot reaction
particles in the power component consists of zirconium in various
crystal modifications, titanium, or mixtures thereof.
8. Ignition element according to one of claims 1 to 7,
characterized in that KClO.sub.3 and/or KClO.sub.4 is used as the
oxidant.
9. Ignition element according to one of claims 1 to 8,
characterized in that polyvinyl acetate, polysulfone, or polyether
sulfone, preferably polyvinyl acetate, is used as the binder.
10. Ignition element according to one of claims 1 or 2,
characterized in that the filament component consists of 20 to 80
parts of picrate, 80 to 20 parts of a mixture of heat-conducting
additive according to claim 5 and oxidant according to claim 8 and
1 to 6 parts of binder according to claim 9, preferably 4 parts of
binder according to claim 9.
11. Ignition element according to claim 10, characterized in that
the mixture of heat-conducting additive and oxidant consists of 60
to 90 parts of heat-conducting additive and 10 to 40 parts of
KClO.sub.4.
12. Ignition element according to one of claims 3 to 9,
characterized in that the filament component consists of 100 parts
of heat-conducting primer, preferably silver azide, and 1 to 6
parts, preferably 4 parts, of binder.
13. Ignition component consisting of at least one primer, at least
one heat-conducting additive, at least one oxidant, and one
binder.
14. Ignition component according to claim 13, characterized in that
lead azide, diazodinitrophenol, silver azide, picrate, or
tricinate, preferably lead picrate, is used as the primer.
15. Ignition component consisting of a heat-conducting primer or a
heat-conducting primer with heat-conducting additive and a
binder.
16. Ignition component according to claim 15, characterized in that
silver azide is used as the heat-conducting primer.
17. Ignition component according to one of claims 13 to 16,
characterized in that inorganic or organic heat-conducting
substances, preferably metals, metal compounds, or organometallic
compounds, are used as the heat-conducting additive.
18. Ignition component consisting of an ingredient that produces
hot reaction particles, an oxidant, and a binder.
19. Ignition component according to claim 18, characterized in that
the ingredient producing hot reaction particles consists of
zirconium in various crystal modifications, titanium, or mixtures
thereof.
20. Ignition component according to one of claims 13 to 16,
characterized in that zirconium, aluminum, titanium, ferrotitanium,
metal compounds, preferably zirconium boride or zirconium hydride
or a mixture of these heat-conducting additives are used as the
heat-conducting additive.
21. Ignition component according to one of claims 13 to 20,
characterized in that KClO.sub.3 and/or KClO.sub.4 is used as the
oxidant.
22. Ignition component according to one of claims 13 to 21,
characterized in that polyvinyl acetate, polysulfone, or polyether
sulfone, preferably polyvinyl acetate, is used as the binder.
23. Ignition component according to claim 13 or 14, characterized
in that it consists of up to 20 to 80 parts of picrate, 80 to 20
parts of a mixture of heat-conducting additive according to claim 5
and oxidant according to claim 8 and 1 to 6 parts of binder
according to claim 9, preferably 4 parts of binder according to
claim 9.
24. Ignition component according to claim 23, characterized in that
the mixture of heat-conducting additive and oxidant consists of 60
to 90 parts of heat-conducting additive and 10 to 40 parts of
KClO.sub.4.
Description
[0001] The invention relates to finely graduatable ignition
components for ignition means and ignition elements.
[0002] The operation of ignition means and ignition elements is
determined essentially by two factors. First, the reaction products
should if possible be particle-rich and these particles should be
as hot as possible, and second a carrier gas must be produced for
the particles so that the particles can penetrate the propellant
charge as well as possible. Also, the carrier gas should have a
high enough temperature to maintain the particle temperature.
Ignition means and ignition elements containing a pyrotechnic fuel
based on B/KNO.sub.2 or Ti/BA(NO.sub.3).sub.2 or
TiHx/Ba(NO.sub.3).sub.2 with x<1 or Zr/Ba(NO.sub.3).sub.2 and
nitrocellulose, but also ignition means and ignition elements that
contain zirconium and potassium perchlorate, generally meet these
requirements.
[0003] In addition to these fundamental performance requirements,
there are other properties that affect the sensitivity and the
safety of these ignition means and ignition elements, and are of
decisive importance for the quality and applicability of such
ignition means and ignition elements. These properties, known as
electrical characteristics, are ignition sensitivity (IS), ignition
insensitivity (IIS), and ignition delay time (IDT) of the
individual components. The ignition insensitivity reflects safety
and the ignition sensitivity or ignition delay time reflects the
ignition sensitivity of the components. Thus far, components with
either sufficiently high ignition insensitivity, but with values
too high for the ignition sensitivity, or ignition delay time, i.e.
with overly low ignition sensitivity or components with
sufficiently low ignition sensitivity and ignition delay time but
insufficient ignition insensitivity are known.
[0004] The goal of the present invention was to prepare ignition
means and ignition elements, hereinafter called ignition elements,
which have not only sufficient performance but also finely
graduatable values for ignition sensitivity and ignition
insensitivity depending on their purpose, without the ignition
delay time being substantially impaired.
[0005] According to the invention, this goal is achieved by
preparing and combining two ignition components with different
properties. The first ignition component, known as the filament
component, is responsible for the electrical characteristics while
the second ignition component, known as the power component, is
responsible for the power. Surprisingly, it has been determined
that, in order to increase the ignition insensitivity of the
filament component without adversely affecting ignition delay time,
it is particularly important to ensure a high degree of heat
conduction in the filament component. This is achieved according to
the invention by an additive able to conduct heat. This
heat-conducting additive is chosen from substances known to be
capable of absorbing heat and thus drawing heat from the
environment. Examples of such substances may be of an inorganic or
organic nature, such as metals, metal compounds, or organometallic
compounds.
[0006] In a first embodiment of the filament component, metals or
metal compounds are provided according to the invention as the
heat-conducting ingredients. The metals preferably used are
zirconium, aluminum, titanium, and/or ferrotitanium. Zirconium is
particularly preferred. Borides and hydrides of the aforesaid
metals are examples of metal compounds that can be used. Zirconium
boride and zirconium hydride are particularly preferred. In
addition to these heat-conducting metal additives, the filament
components of the ignition elements according to the invention
contain at least one primer such as lead azide, diazodinitrophenol,
silver azide, tricinate, or picrate, preferably lead picrate, as
well as an oxidant such as alkali or alkaline earth nitrates,
chlorates, perchlorates, preferably KClO.sub.3 and/or KClO.sub.4,
especially preferably KClO.sub.4 and a binder. The binder is
responsible not only for binding the individual components but also
for the heat resistance of the ignition elements; they should have
a heat resistance of >85.degree. C. Binders that are appropriate
according to the invention are thus polyvinyl acetate, polysulfone,
or polyether sulfone. Polyvinyl acetate is preferably used. While
the heat-conducting additive has the function of increasing
ignition insensitivity, the primer used is responsible for ensuring
the necessary ignition sensitivity. According to the invention, the
filament components of the first embodiment are composed of 20 to
80 parts of primer, preferably lead picrate, 20 to 80 parts of a
mixture of heat-conducting additive and oxidant, and 1 to 6 parts
of binder. The mixture of heat-conducting additive and oxidant is
composed of 60 to 90 parts of heat-conducting additive and 10 to 40
parts of oxidant. In a second embodiment of the filament component,
the heat-conducting ingredient provided according to the invention
is a heat-conducting primer, preferably silver azide, possibly in
combination with other heat-conducting ingredients such as metals,
metal compounds, or organometallic compounds. In this embodiment,
zirconium, aluminum, titanium and/or ferrotitanium can be used as
the metals, and borides and hydrides, preferably zirconium boride
and zirconium hydride, can be used as the metal compounds. The
particular advantage of using silver azide is that it functions
simultaneously as a heat-conducting additive and in its capacity as
an primer improves the ignition sensitivity. If silver azide
exclusively is used according to the invention, the filament
component will consist of 100 parts of silver azide and 1 to 6,
preferably 4, parts of binder. Polyvinyl acetate is the preferred
binder with the same functions as in the first embodiment.
[0007] The power component according to the invention consists of
an ingredient that produces hot reaction particles, and of one of
the above-listed oxidants, and of one of the aforesaid binders.
Zirconium in its various crystal modifications, titanium, or
mixtures thereof are suitable ingredients for producing the hot
reaction particles. KClO.sub.3 and/or KClO.sub.4, preferably
KClO.sub.4 for example, can be used as the oxidant. The binders
used are preferably the same substances used for the filament
component. The power components according to the invention are
composed of 30 to 80 parts of zirconium, titanium, or mixtures
thereof, 20 to 70 parts of oxidant, preferably KClO.sub.4, and 1 to
6 parts of binder. Preferably, a mixture of 60 parts of zirconium,
40 parts of KClO.sub.4, and 4 parts of polyvinyl acetate are
used.
[0008] The components according to the invention can be used in
many different ways alone or in combination. If the filament
component according to the invention is combined with the power
component according to the invention, finely graduatable ignition
elements result.
[0009] The ignition elements according to the invention are made
for example as follows. The ingredients of the filament component
and the power component are screened and suspended in the binder
dissolved in an appropriate solvent. If polyvinyl acetate is used
as the binder, butyl acetate is a suitable solvent. This suspension
is made dippable, i.e. the viscosity is adjusted accordingly. It is
extremely important in this connection for the ingredients not to
settle out during dipping. To ensure this, the ignition component
suspension is for example homogenized by careful stirring, with
safety precautions. Ignition elements are generally made in the
form of ignition pellets. A conventional ignition pellet consists
for example of two elongate electrically conducting pole carriers
(bars) connected by an insulating connector and a connecting
filament linking the pole carriers. An ignition pellet element of
this type is dipped several times into the ignition component
suspension such that the first ignition component surrounds the
connecting filament. The dipping process is repeated until a
sufficient quantity of filament component mixture has been applied
for the application in question. Quantities of 6 to 10 mg for the
first ignition component have proven satisfactory. Between the
individual dippings, the solvent is allowed to evaporate. After the
filament component, the power component is applied in the same
manner as a coating around the filament component. For this
component as well, the dipping process is repeated until a
sufficient quantity of power component mixture has been applied for
the application in question. Additive weights that have proven
satisfactory for the ignition component for the entire ignition
pellet are 50 to 100, preferably 65 to 85 mg. When the ignition
pellet has dried for 24 hours, it is given a 20% coating made of
the binder in question and dried for a further 48 hours.
[0010] The ignition components according to the invention can be
used for ignition elements resistant to high temperatures,
depending on the binder used. If polysulfone or polyether sulfone
for example is used as the binder, the ignition components
according to the invention can be used at temperatures of up to
250.degree. C. The ignition elements according to the invention are
particularly suited for ignition of propellant charges that require
lengthy exposure to a hot flame, and for insensitive propellant
charges that require hot metal particles.
[0011] The ignition component mixtures given in Table 1 will
explain the invention in more detail but without limiting it.
[0012] The following are used as filaments:
[0013] Filament I: Cr/Ni 2938 Ohm/m, bright, hard, 0.5 mm
[0014] Filament II: Cr/Ni 2823 Ohm/m bright, soft, 0.5 mm
[0015] Filament III: Cr/Ni 2827 Ohm/m, bright, hard, 0.5 mm
[0016] Filament IV: Cr/Ni 2631 Ohm/m, bright, soft, 0.7 mm
[0017] Filament V: Cr/Ni 2649 Ohm/m, bright, hard, 0.7 mm
[0018] Filament VI: Cr/Ni 2649 Ohm/m, bright, hard, 0.5 mm
1TABLE 1 Example 1 2 3 4 5 6 7 8 9 10 11 12 picrate (parts) 50 50
40 40 40 -- 50 50 50 40 40 30 mixture (parts) 50 50 60 60 60 100 50
50 50 60 60 70 (consisting of: 60 60 60 60 60 100 80 80 80 80 80 80
heat-conducting 40 40 40 40 40 -- 20 20 20 20 20 20 additive
(parts) and KClO.sub.4 (parts) Mowilith (parts) 4 4 4 4 4 4 4 4 4 4
4 4 filament I IV I II IV IV II IV III II V VI ignition 233 245 263
272 280 308 234 236 238 260 256 304 sensitivity (mA) ignition 546
640 550 587 670 605 513 550 499 513 538 579 insensitivity (mA)
ignition delay 1.04 1.27 1.10 1.09 1.27 0.69 0.80 0.84 0.73 0.76
0.77 1.02 time (ms)
* * * * *