AU778545B2 - A detonation initiating device - Google Patents
A detonation initiating device Download PDFInfo
- Publication number
- AU778545B2 AU778545B2 AU14039/00A AU1403900A AU778545B2 AU 778545 B2 AU778545 B2 AU 778545B2 AU 14039/00 A AU14039/00 A AU 14039/00A AU 1403900 A AU1403900 A AU 1403900A AU 778545 B2 AU778545 B2 AU 778545B2
- Authority
- AU
- Australia
- Prior art keywords
- ddnp
- initiating device
- detonation initiating
- detonation
- particulate form
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Ceased
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Classifications
-
- C—CHEMISTRY; METALLURGY
- C06—EXPLOSIVES; MATCHES
- C06B—EXPLOSIVES OR THERMIC COMPOSITIONS; MANUFACTURE THEREOF; USE OF SINGLE SUBSTANCES AS EXPLOSIVES
- C06B45/00—Compositions or products which are defined by structure or arrangement of component of product
- C06B45/02—Compositions or products which are defined by structure or arrangement of component of product comprising particles of diverse size or shape
-
- C—CHEMISTRY; METALLURGY
- C06—EXPLOSIVES; MATCHES
- C06C—DETONATING OR PRIMING DEVICES; FUSES; CHEMICAL LIGHTERS; PYROPHORIC COMPOSITIONS
- C06C7/00—Non-electric detonators; Blasting caps; Primers
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Crystallography & Structural Chemistry (AREA)
- Air Bags (AREA)
- Shaping Metal By Deep-Drawing, Or The Like (AREA)
- Automotive Seat Belt Assembly (AREA)
Description
WO 00137395 PCT/IB99/01971 1 A DETONATION INITIATING DEVICE INTRODUCTION AND BACKGROUND TO THE INVENTION This invention relates to a detonator and to a detonation initiating device for a detonator.
Conventional electric or electronic detonators are usually provided with a detonation initiating device, which often comprises a metal resistive wire embedded in primary explosives compositions based on lead styphnate or lead picrate. Alternatively, the metal resistive wire may be embedded in pyrotechnic compositions based on intimate mixtures of heavy metals such as cerium, tantalum or boron in combination with an oxidiser. Such detonation initiating device is commonly known as a fuse head.
Alternatively to the fuse head, various other detonation initiating devices, for use with electrical or electronic detonators, are known. Examples of these are thick film, printed, resistive bridge initiators; vacuum deposited thin film bridge initiators; and so-called SCB initiating devices.
A thick film bridge initiator usually comprises a printed resistor extending between two conductors which are insulated from each other, the resistor WO 0087395 PCT/IB99/01971 2 being either polymeric or ceramic in nature, as is common in hybrid electronic technology. The bridge is trimmed or printed to value.
A thin film bridge usually comprises a central conductor; and an annular conductor surrounding the central conductor, the conductors being spaced by a glass substrate. A metal layer forming a resistor is vacuum deposited on the glass substrate to connect the conductors, with the metal layer often being trimmed to value.
A SCB initiating device uses silicon doping compositions to generate plasma between two spaced conductors, when an electrical current is passed through.
To amplify the electric energy flowing through the resistors or plasma of the above initiating devices, into a flame or detonation able to initiate explosives in proximity to the resistor, the resistor or SCB is disposed in close contact with either a primary explosive or pyrotechnic compositions of the type commonly used in fuse head manufacture.
A disadvantage of the explosive or pyrotechnic compositions of the type commonly used with fuse heads or other initiating devices is that they are usually mechanically and electrically sensitive to uncontrolled initiation.
26-10-'04 13:53 FROM- T-386 P003/006 F-379 .3PElhtEPSCInCATOMElU24487O0 ad q. WIXMd 3 Another disadvantage of such compositions is that toxic heavy metal particles are released into atmosphere upon explosion of the initiating explosives.
The present invention seeks to provide a detonator and a detonation initiating device for a detonator with which the aforesaid disadvantages may be overcome or at least minimised.
SUMMARY OF THE INVENTION According to a first aspect of the invention there is provided a detonation initiating device for a detonator, the device including: two spaced electrical conductors; a resistive substance extending between the electrical conductors, for releasing energy upon application of an electrical current to 15 the resistive substance; and an explosive composition including diazodinitrophenol (DDNP), covering the resistive substance wherein the resistive substance constitutes a thick film bridge.
Diazodinitrophenol (DDNP) has been used in the past as a main explosive charge in detonators. However, because it is as such relatively insensitive to mechanical and electrical initiation, it has thusfar not been considered as an COMS ID No: SBMI-00971279 Received by IP Australia: Time 13:57 Date 2004-10-26 *26-10-'04 13:54 FROM- T-386 P004/006 F-379 P %O?9W~veWSMWCATOW)j!24U0id wo dm-Zfl&d 4 initiating explosive in detonation initiating devices, for electric and electronic detonators.
The explosive composition may further include a binder.
The binder may be an energetic material. Preferably the binder is selected from n itro-cellulose and polyvinyl nitrate.
Alternatively the binder may be non- energetic. Pr~ferably the binder is selected from acrylate and natural gum.
Yet further according to the Invention, the explosive composition includes DDNP in fine particulate form as well as in a relatively larger particulate form.
COMS ID No: SBMI-00971279 Received by IP Australia: Time 13:57 Date 20D4-10-26 -26-10-'04 13:54 FROM- T-386 P005/006 F-379 paATtisCmian2Amtwes.-ida wwwh2Ifl The DDNP in fine particulate form may have a particle size which is magnitudes smaller than the DDNP in relatively larger particulate form.
The DDNP in particulate form may be a precipitate of a mixture of DDNP and said binder.
The DDNP in particulate form may be in a crystalline or modified crystalline form.
The DDNP in particulate form may be prepared substantially as described in the patent specification of DE 4117717.
The DDNP in particulate form may include compounds selected from S1 explosive, oxidisers, fuels and/or reducing agents.
The oxidisers may be selected from chlorates, nitrates, perchlorates, and oxides and the fuels may be selected from the group comprising metals and metal sulphides.
20 In an embodiment of the invention the fine particulate DDNP may have a particle size which is at least five times smaller than the smallest dimension of the thick film bridge. Preferably the fine o COMS ID No: SBMI-00971279 Received by IP Australia: Time 13:57 Date 2004-10-26 26-10-'04 13:54 FROM- T-386 P006/006 F-379 6 particulate DDNP has a particle size which is at least ten times smaller than the smallest dimension of the thick film bridge.
The ratio between the fine particulate DDNP and the DDNP in relatively larger particulate form may be between 1:99 and 20:80 on a mass per mass basis. Preferably the ratio between the fine particulate DDNP and the DDNP in relatively larger particulate form is 5:95 on a mass per mass basis.
The arrangement may be such that when an external current is applied to the resistive substance, the fine particulate DDNP ignites, to initiate ignition of the DDNP in relatively larger particulate form, which in turn ignites a detonator charge.
o Further according to the invention, the DDNP in fine particulate form may be 15 applied separately to the resistive bridge, in an ink of the type used to print polymer thick film bridges substantially as disclosed in South African patent number 95/1680. This increases the reliability of ignition of the explosives in contact with the resistive bridge.
20 Further according to the invention, the DDNP is enclosed. Preferably the DDNP is enclosed by a layer comprising a polymeric material or a resin.
b COMS ID No: SBMI-00971279 Received by IP Australia: Time 13:57 Date 2004-10-26 -WO 00/37395 PCT/IB99/01971 7 According to a second aspect of the invention there is provided a detonator including a detonation initiating device according to the first aspect of the invention.
BRIEF DESCRIPTION OF THE DRAWING The invention will now be described further by way of a non-limiting example with reference to the accompanying drawing, which is a diagrammatical cross-sectional view of a detonation initiating device 10 according to a preferred embodiment of the invention for a detonator (not shown).
DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION The detonation initiating device 10 includes two spaced electrical conductors 12 located on an insulating substrate 14; a thick film resistive bridge 16 extending between the electrical conductors 12, for releasing energy upon application of an electrical current to the resistive bridge 16; and an explosive composition, generally designated by reference numeral 18, covering the resistive bridge 16.
The explosive composition 18 is prepared from an energetic nitro-cellulose binder 17 and diazodinitrophenol (DDNP), substantially as described in the patent specification of DE 4117717, to include DDNP in fine particulate form 18.1 as well as in a relatively larger particulate form 18.2. The DDNP in fine WO 0.0/37395 PCT/! B99/01971 8 particulate form 18.1 has a particle size which is magnitudes smaller than the DDNP in relatively larger particulate form 18.2 and at least ten times smaller than the smallest dimension X of the resistive bridge 16. The ratio between the fine particulate DDNP 18.1 and the DDNP in relatively larger particulate form 18.2 is 5:95 on a mass per mass basis.
The DDNP in particulate form is preferably in a crystalline state and the explosive composition 18 includes additional compounds such as other explosives, oxidisers, fuels and/or reducing agents. The oxidisers are selected from the group comprising chlorate, nitrate, perchlorate, and oxides and the fuels are selected from the group comprising metals and sulphides.
Preferably the oxidiser is lead monoxide (PbO) and the fuel metal is zirconium.
The DDNP in fine particulate form 18.1 may alternatively be applied separately to the resistive bridge 16, in ink of the type used to print polymer thick film bridges substantially as disclosed in South African patent number 95/1680.
The explosives composition 16 is enclosed by a polymeric layer In use, an external current is applied to the contacts 12 to energise the 25-10-04: 2:47PM:DAVIES COLLISON CAVE 9/ 23 9 resistive bridge 16, which ignites the fine particulate DDNP 18.1. The fine particulate DDNP 18.1 initiates ignition of the DDNP in relatively larger particulate form 18.2, which in turn Ignites a detonator charge (not shown).
The detonation initiating device accordirig to the invetion, is not only very stable and resistaht to accidental explosion, but also very: reliable due to the presence of the fine particulate D.DNP.
Furthermore, the explosive composition of the detonation initiating device 10 can be initlated even at the low energy levels at which electronic initiating de'vices usually operate.
It will be appreciated that no heavy metal particles are released by the detonation Initiating device according to the invention,- during explosion.
It will be appreciated further that variations in detail are possible with a detonator and a detonation initiating device according to the invention without departing from the scope and/or spirit of the appended claims The reference to any prior art in this specification is not, and should not be taken as, an acknowledgment or any form of suggestion that that prior art forms part of the common general knowledge in Australia.
COMS ID No: SBMI-00969338 Received by IP Australia: Time 15:07 Date 2004-10-25 25-10-04: 2:47PM:DAVI:ES COLLISON CAVE #10D/23 -9A- Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise", and variations such as "comprises" and "comprising", will be understood to imply the inclusion of a stated Integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.
0 00 COMS IDNo:SBMI-00969338 Received by IP Australia: Time 15:07 Date 2004-10-25
Claims (1)
- 25-10-04: 2:47PM:DAVIES COLLISON CAVE 11/ 23 THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS: 1. An electronic detonation initiating device, the device including two spaced electrical conductors; a resistive substance extending between the electrical conductors, for releasing energy upon application of an electrical current to the resistive substance; and an explosive composition including diazodinitrophenol (DDNP), covering the resistive substance wherein the resistive substance constitutes a 10 thick film bridge. 2. A detonation initiating device according to claim 1 wherein the explosive composition further includes a binder. 3. A detonation initiating device according to claim 2 wherein the binder is an energetic material. 4. A detonation initiating device according to claim 3 wherein the binder is selected from nitro-cellulose and polyvinylnitrate. 5. A detonation initiating device according to claim 2 wherein the binder is non-energetic. 6. A detonation initiating device according to claim 5 wherein the binder is selected form acrylate and natural gum. 7. A detonation initiating device according to any one of the preceding claims wherein the explosive composition includes DDNP in fine particulate form as well as in a relatively larger particulate form. 8. A detonation initiating device according to claim 7 wherein the DDNP COMS ID No: SBMI-00969338 Received by IP Australia: Time 15:07 Date 2004-10-25 25-10-04: 2:47PM:DAVIES COLLISON CAVE 12/ 23 -11 in fine particulate form has a particle size which is magnitudes smaller than the DDNP in relatively larger particulate form. 9. A detonation initiating device according to claim 7 or claim 8 wherein the DDNP in particulate form is a precipitate of a mixture of DDNP and a binder. A detonation initiating device according to any one of claims 7 to 9 wherein the explosives composition includes at least one compound 10 selected from other types of explosives, oxidisers, fuels and/or reducing agents. 0:0 11. A detonation initiating device according to claim 10 wherein the oxidisers are selected from chlorates, nitrates, perchlorates and B oxides, and wherein the fuels are selected from metals and metal sulphides. 12. A detonation initiating device according to any one of claims 7 to 11 wherein the DDNP in particulate form is in a crystalline or modified 20 crystalline form. 13. A detonation initiating device according to any one of claims 7 to 12 wherein the fine particulate DDNP has a particle size which is at least five times smaller than the smallest dimension of the thick film bridge. 14. A detonation initiating device according to claim 13 wherein the fine particulate DDNP has a particle size which is at least ten times smaller than the smallest dimension of the thick film bridge. 15. A detonation initiating device according to any one of claims 7 to 14 wherein the ratio between the fine particulate DDNP and the DDNP COMS ID No: SBMI-00969338 Received by IP Australia: Time 15:07 Date 2004-10-25 25-10-04; 2:47PM:DAVIES COLLISON CAVE 13/ 23 -12- in relatively larger particulate form is between 1:99 and 20:80 on a mass per mass basis. 16. A detonation initiating device according to claim 15 wherein the ratio between the fine particulate DDNP and the DDNP in relatively larger particulate form is 5:95 on a mass per mass basis. 17. A detonation initiating device according to any one of claims 7 to 16 wherein when an external current is applied to the resistive 10 substance the fine particulate DDNP ignites, to initiate ignition of the DDNP in relatively larger particulate form, which in turn ignites a detonator charge. 18. A detonation initiating device according to any one of the preceding claims wherein the DDNP is enclosed. 19. A detonation initiating device according to claim 18 wherein the DDNP is enclosed by a layer comprising a polymeric material or a resin. 20. A detonation initiating device substantially as herein described with reference to the accompanying drawing. 21. A detonator including a detonation initiating device as claimed in any one of claims 1 to DATED this 2 5 th day of October 2004. Or;ca Cxo(csives 7-cFncootu- k L -st T S(PropriaSEC -0 113 by their Patent Attorneys O DAVIES COLLISON CAVE COMS ID No: SBMI-00969338 Received by IP Australia: Time 15:07 Date 2004-10-25
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| ZA98/11701 | 1998-12-21 | ||
| ZA9811701 | 1998-12-21 | ||
| PCT/IB1999/001971 WO2000037395A1 (en) | 1998-12-21 | 1999-12-09 | A detonation initiating device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| AU1403900A AU1403900A (en) | 2000-07-12 |
| AU778545B2 true AU778545B2 (en) | 2004-12-09 |
Family
ID=25587467
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| AU14039/00A Ceased AU778545B2 (en) | 1998-12-21 | 1999-12-09 | A detonation initiating device |
Country Status (5)
| Country | Link |
|---|---|
| EP (1) | EP1171402A1 (en) |
| AR (1) | AR021942A1 (en) |
| AU (1) | AU778545B2 (en) |
| CA (1) | CA2355256A1 (en) |
| WO (1) | WO2000037395A1 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE10221044A1 (en) * | 2001-05-10 | 2002-11-14 | Dynamit Nobel Ag | Igniter composition useful for coating metal strip, hot wire or spark gap igniters comprises soluble igniter substances e.g. cesium azotetrazolate |
| DE102004004748A1 (en) * | 2003-03-08 | 2004-09-23 | Dynamit Nobel Ais Gmbh Automotive Ignition Systems | Pyroelectric igniter for explosive charge has housing containing capsule with glass filling, support bridge and ignition charge, and has electrical conductor rods embedded in glass |
| JP4787515B2 (en) * | 2005-03-04 | 2011-10-05 | 旭化成ケミカルズ株式会社 | Explosive-containing film |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2960933A (en) * | 1945-10-12 | 1960-11-22 | Hercules Powder Co Ltd | Detonator |
| FR2090579A5 (en) * | 1970-04-24 | 1972-01-14 | Dynamit Nobel Ag | |
| CA1150513A (en) * | 1980-09-19 | 1983-07-26 | Lechoslaw A.M. Utracki | Ignition material for detonators or squibs containing polysulfide binder |
Family Cites Families (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2195032A (en) * | 1938-04-16 | 1940-03-26 | Atlas Powder Co | Detonator |
| US4858529A (en) * | 1988-07-01 | 1989-08-22 | The United States Of America As Represented By The Department Of Energy | Spark-safe low-voltage detonator |
| DE4143631A1 (en) | 1991-05-30 | 1998-04-16 | Dynamit Nobel Ag | Production of detonator as fine crystals with a specified size |
| FR2704944B1 (en) * | 1993-05-05 | 1995-08-04 | Ncs Pyrotechnie Technologies | Electro-pyrotechnic initiator. |
| US5648634A (en) * | 1993-10-20 | 1997-07-15 | Quantic Industries, Inc. | Electrical initiator |
| US5646367A (en) * | 1996-03-01 | 1997-07-08 | Remington Arms Company, Inc. | Conductive primer mix |
| DE19806388A1 (en) * | 1997-03-07 | 1998-09-10 | Dynamit Nobel Ag | Priming agent element coated with polyurethane protective lacquer |
| US5889228A (en) * | 1997-04-09 | 1999-03-30 | The Ensign-Bickford Company | Detonator with loosely packed ignition charge and method of assembly |
-
1999
- 1999-12-09 CA CA002355256A patent/CA2355256A1/en not_active Abandoned
- 1999-12-09 WO PCT/IB1999/001971 patent/WO2000037395A1/en active IP Right Grant
- 1999-12-09 EP EP99973485A patent/EP1171402A1/en not_active Withdrawn
- 1999-12-09 AU AU14039/00A patent/AU778545B2/en not_active Ceased
- 1999-12-20 AR ARP990106599 patent/AR021942A1/en unknown
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2960933A (en) * | 1945-10-12 | 1960-11-22 | Hercules Powder Co Ltd | Detonator |
| FR2090579A5 (en) * | 1970-04-24 | 1972-01-14 | Dynamit Nobel Ag | |
| CA1150513A (en) * | 1980-09-19 | 1983-07-26 | Lechoslaw A.M. Utracki | Ignition material for detonators or squibs containing polysulfide binder |
Also Published As
| Publication number | Publication date |
|---|---|
| CA2355256A1 (en) | 2000-06-29 |
| WO2000037395A1 (en) | 2000-06-29 |
| EP1171402A1 (en) | 2002-01-16 |
| AU1403900A (en) | 2000-07-12 |
| AR021942A1 (en) | 2002-09-04 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PC1 | Assignment before grant (sect. 113) |
Owner name: ORICA EXPLOSIVES TECHNOLOGY PTY LTD Free format text: THE FORMER OWNER WAS: SMI TECHNOLOGY (PROPRIETARY) LIMITED |
|
| MK14 | Patent ceased section 143(a) (annual fees not paid) or expired |