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Publication numberUS3835782 A
Publication typeGrant
Publication dateSep 17, 1974
Filing dateSep 22, 1972
Priority dateSep 22, 1972
Also published asCA995059A1
Publication numberUS 3835782 A, US 3835782A, US-A-3835782, US3835782 A, US3835782A
InventorsG Griffith, D Edwards
Original AssigneeCommercial Solvents Corp
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Product and method
US 3835782 A
Abstract
An explosive device including means permitting identification of the explosive source or manufacturer even following detonation, and a method of identifying the source or manufacturer of an explosive device even after detonation thereof. A luminescent material is added to the explosive device having a non-thermal emission of electromagnetic radiation upon excitation which uniquely identifies the source or manufacturer of the explosive. The luminescent material may be pulverized and mixed with the explosive material within the device. Alternatively, the luminescent material may be added to the exterior of the explosive device. Following detonation of the explosive device, the area around the detonation is activated or excited, and the luminescent material is identified from the resulting luminescent radiation.
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Description  (OCR text may contain errors)

PRODUCT AND METHOD Inventors: George L. Griffith, Coopersburg;

Donald W. Edwards, Lehighton,

both of Pa.

[73] Assignee: Commercial Solvents Corporation,

New York, NY.

[22] Filed: Sept. 22, 1972 [2]] App]. No.: 291,171

[52] US. Cl 102/27 R [51] Int. Cl. C06c 5/04 [58] Field of Search 102/27 [56] References Cited UNITED STATES PATENTS 3,474,730 10/1969 Sheeran 102/27 3,712,222 1/1973 Richardson et al 102/27 [4 1 Sept. 17, 1974 Attorney, Agent, or Firm-Morton, Bernard, Brown, Roberts & Sutherland [57] ABSTRACT An explosive device including means permitting identification of the explosive source or manufacturer even following detonation, and a method of identifying the source or manufacturer of an explosive device even after detonation thereof. A luminescent material is added to the explosive device having a non-thermal emission of electromagnetic radiation upon excitation which uniquely identifies the source or manufacturer of the explosive. The luminescent material may be pulverized and mixed with the explosive material within the device. Alternatively, the luminescent material may be added to the exterior of the explosive device. Following detonation of the explosive device, the area around the detonation is activated or excited, and the luminescent material is identified from the resulting luminescent radiation.

23 Claims, No Drawings PRODUCT AND METHOD The present invention pertains to explosive devices. More particularly, the present invention pertains to a method of identifying the source of explosive devices even after detonation of the explosive and to explosive devices including means enabling identification of the source of the explosive even after detonation thereof.

Explosive devices are often used in illegal manners to harm, and even kill, persons, to damage property, for instance, to make openings in buildings, permitting unlawful access to property, and the like. Following such explosions, the police and other authorities must attempt to identify the responsible persons. If the source of the explosive device can be determined, this frequently aids in identifying and apprehending the responsible persons. Generally, such explosions are of a strength which essentially completely destroys the explosive device, including both the explosive material and its container. Consequently, little or no identifiable evidence is available from which the source of the explosive device can be determined.

In one aspect, the present invention is'a method of identifying the source of an explosive device utilized in an explosion after detonation of that explosive. In another aspect, the present invention is an explosive device incorporating a luminescent material which, following explosion of explosive device, enables its detection through luminescent radiation. Different manufacturers or sources of explosive devices can thus incorporate luminescent materials which emit different electromagnetic wavelengths so that, by identifying the wavelength of the luminescent radiation, the manufacturer or source of the explosive can be identified.

Upon excitation, luminescent materials emit visible or invisible electromagnetic radiation unaccompanied by high temperatures. The excitation of the materials may be by other electromagnetic radiation, by charged particles, or by chemical change. Most commonly, luminescent materials which are excited by electromagnetic radiation, particularly ultraviolet radiation (long wave and short wave) are employed. Generally, luminescent materials are fluorescent, that is, materials from which emission of luminescent radiation stops upon cessation of supplying the excitation energy, or phosphorescent, that is, materials from which emission of luminescent radiation continues for at least about second after the source of excitation is removed. Luminescent radiation is generally a narrow bandwidth radiation such that upon excitation not only the presence of a luminescent material, but also usually the identity of the material can be ascertained. Often the luminescent radiation is in the infrared, visible, or ultraviolet portion of the electromagnetic radiation spectrum. Often, with luminescent materials which provide a visible emission, the unaided eye can detect and identify the material. With invisible radiations from such luminescent materials, instruments are required for detection and identification.

Luminescent materials may be crystalline or liquid;

however, crystalline materials are preferred for application in the present invention. Normally liquid phase luminescent materials may be employed by, for instance, coating a particulate substrate material with the liquid. The luminescent materials may be inorganic or organic and may occur naturally or may be synthetically produced. Admixtures of luminescent materials may be employed. Such admixtures may, for instance, have luminescent materials which respond to different forms of excitation energy, for example, onematerial may be excited by ultraviolet radiation and another material may be excited by infrared radiation. Also, an admixture may contain two or more luminescent materials which respond to essentially the same form of excitation energy. Thus, if one component is masked by the surroundings, another component may still be identifiable and the manufacturer of the explosive device can be ascertained. The use of two or more luminescent materials may also provide more flexibility and combinations to assist in the marking and identification of explosives.

Exemplary of luminescent material operable in this invention are naturally occurring luminescent materials including scheelite (CaWO willemite (Zn SiO calcite (CaCO scapolite ((Na Ca) Al (Al Si) 'Si O '(Cl, C05,, sphalerite (ZnS), rhodochrosite ((Fe, Cs, Mg, Zn) MnCO and other naturally occurring fluorescent oxides, halides, carbonates, and the like. Synthetic samples of these naturally occurring materials and other combinations may be prepared and may fluoresce when properly doped with selected impurities. Examples of synthetic luminescent materials are strontium orthophosphate, calcium halophosphate, zinc sulfide, zinc sulfide-cadmium sulfide, and the like provided with proper activator metals. Activator metals which have been employed are, for example, tin, antimony, manganese, the rare earths such as europium, yttrium, cerium, samarium, etc., and the like. Other inorganic luminescent materials are derived from the rare earths. For example, samarium nitrate, dysprosium nitrate, and the like. Solid organic compounds such as stibene, naphthalene, anthracene, and phenanthrene exhibit luminescent properties as do some organic dyes and the like. The luminescent material should be selected such that it achieves or retains luminescent properties after detonation of the explosive. High temperature explosives generally require more stable luminescent materials than explosives providing less severe conditions, when the luminescent material is admixed with the explosive material. If the explosive material is provided on the explosive device, for instance, in the label, thermal stability is less of a concern.

In accordance with the present invention, luminescent material is incorporated in the explosive device by, for instance, admixing it with the explosive material or incorporating it into or coating it on the material employed for the container of the explosive charge. For instance, the luminescent material can be deposited on the exterior of the explosive device container by, for example, sprinkling the luminescent particles onto the container whichhas previously been coated with an adhesive such as clear polyurethane. The luminescent material may be admixed with, for instance, molten wax into which the explosive is dipped to form a container. Plastic explosive device containers may be formed with luminescent particles therein. Further, the luminescent material may be incorporated into the ink with which markings on the explosive device label are printed.

The amount of luminescent material should be sufficient to result in the presence of detectable luminescent material subsequent to detonation of the explosive device. Generally, when detecting traces of the luminescent material by the unaided eye, the luminescent material should be provided in an amount generally less than about 2, for sake of convenience, preferably at least about 0.025, more preferably 0.05 to 1, percent by weight. The amount required depends upon several of high energy such as ammonium nitrate, dynamites, trinitrotoluene, nitrocarbon nitrates, and the like, or relatively low energy explosives such as black powder. A further discussion of explosives can be found in the factors, for example, the intensity of the luminescent 5 Encyclopedia of Chemical Technology, Second Edition, radiation, the particle size, the number of particles in Volume 9, Pages 531 I0 the explosive device, the strength of the explosive de- The following examples further illustrate the invenvice, where the luminescent particles are incorporated IiOHI in the explosive device and how they will be distributed upon detonation, and the like. Thus, less than 0.025 EXAMPLE! percent luminescent material may be sufficient for a A sample of franklinite Zinc Ore, Obtained from low powered explosive device whereas greater than 2 Franklin, New Jersey, is comminuted and screened percent luminescent material may be required when througha40 mesh screen (U.S. Sieve Series). The ironemploying a high energy explosive. Generally, when containing franklinite particles are removed with a the luminescent material is provided on the explosive magnet and a ten gram sample of the remaining ore is container in, for example, a printed label, or when the mixed with only one kilogram ofa forty percent ammomaterial is incorporated in the explosive container, less nium dynamite, nitrostarch base, explosive powder, luminescent material will be required than if it is in adhereinafter designated as 4OWR powder. A ten gram mixture with the explosive powder. For instance, consample of this mixture detonated in a test cannon (Seicentrates as low as about 0.01 or less weight percent ple Test Lab Ballistics Pendulum Cannon). When the luminescent material may be operable. Other means of cannon is subsequently checked with ultraviolet light, luminescent particle detection and identification may particles of the luminescent material can be visibly derequire different relativeamounts of luminescent partitected as light pale green: H cles.

The luminescent material should be provided in a EXAMPLE II F 1e Slze z g eu f i Two weight percent of the above ore is admixed with can e ma en emp oynlg l meanso 4OWR powder and formed into one-and-one-fourth F generally average P We inch by eight inch stick of explosive. The stick is then mbmesc4ent material aftfer detonation shouldbbe at least suspended within a clean empty 55 ganon drum and a out nllcrons erably larger. than. a out 50 m]- detonated. Under ultraviolet light, particles of the ore crons m i l large}- part'cle the are visibly detected by their light pale green color on her of particles which can be incorporated mto the expieces of the drum.

plosive device IS limited. Generally, the luminescent material should have an average particle size of less EXAMPLE [[1 .than i 2000 preferably les.s than 1.000 9 9 About 0.25 weight percent Pl phosphor is mixed with crons m 'T' Easy detectlon and lqemlficat'on of sixty percent ammonium, nitrostarch base, explosive small? lg z mlcfon g powder, herein after referred to as 6OWR powder, and 2:3 ig i z ilfififig'i z gz g g an I end etonated as a one-and-one-fourth inch by eight inch It may be desirable to provide a mixture of large and 40 Suck m a barrel as m Example Pl phosphor is a sulfide-based phosphor obtainable i size i i g fg tqfasslst i. from the United States Radium Corporation. The phoszfig iggg g g ii pg ii qg g j gg jgg T: phor can be detected under ultraviolet light. The phostion of the luminescent mgterial y be g phor is exceptionally fine and more difficult to identify 5 by the visible eye after explosion than is the luminesslze of about +100 200 mesh (U.S. Sieve Series).Th1s

cent material in Examples l and II. luminescent material may be visually identifiable by ex- 7 ,7 a citation with ultraviolet radiation. Thus after an explosion, the investigating authorities may comb the area EXAMPLE W with ultraviolet lamps to visually detect the location of About 0.5 weight percent Pl phosphor is mixed with the large particle size luminescent materials. The re- 6OWR powder and detonated as in Example IV. The maining portion ofthe luminescent material may not be results are substantially the same as in Example lll. easily visibly detectable or may require other means of excitation. Upon locating the large particle size lumi- EXAMPLES v XI nescent material, samples may be collected from sur- One weight percent of the following phosphors, obrounding surfaces, and the collected material may be tainablefrom the United States Radium Corporation, analyzed in a laboratory having the appropriate detecare added to samples of a standard 4OWR powder, and tion equipment for identifying the manufacturer of the the resulting mix is checked by the naked eye for detecexplosive from the luminescent material. tion of visible emissions upon excitation of the lumines- This invention is operable with essentially all explocent material by short and long wave ultraviolet radiasive devices. Various types of explosives include gasetion, both before and after detonation as in Example ll, ous, liquid, and solidexplosives. The expl osives rnay be with results indicated below:

SHORT WAVE LONG WAVE (ABOUT 1500 to 2600A) (ABOUT 3600 to 3700A) Ex. Type Before After Before After Detonation Detonation Detonation Detonation Radelin Phosphor I] l lcate; Mn; GS- l l5 Yes No Yes No Radelin Phosphor n llcate;

SHORT WAVE LONG WAVE (ABOUT 1500 to 2600A) (ABOUT 3600 to 3700A) Ex. T Before After Before After Detonation Detonation Detonation Detonation Helecon Phos horescent Pi ment VI 5564 Yes No Yes No (zinc sulfidecadmium I sulfide base) VII 2315 Yes No Yes No (zinc sulfide cadmium sulfide base) .VIII 2330 Yes No Yes No (zinc sulfide base) IX 2330 No N N0 N0 (zinc sulfide base) Helecon Fluorescent Pigment es No Yes No XI 2330 Yes No Yes No x b WWI-m 0W7 Um I W V V m w Overs fr m 9M=WPP 99 w CONTAMINANT Human The inability to detect the lumlnescent material after Example T ge Oil Grease Gasoline Waste detonation is due to the inability of the unaided eye to {bidetect the emission. silicate;

I iiii V I I l V I Mn; GS-IIS No No No EXAMPLES XII XVIII X About 0.5 weight percent of the following phosphors 2304 Yes Yes Yes is added to samples of a standard 4OWR powder, and xvm 5 Yes Yes y d r 100 wer micro- XXIX- the resulting mix is checked un e a I p0 XXX] 2330 Yes Yes Yes scope for detection of visible light emissions under ex- Xxx" citation as in Examples V XI with results as indicated 2330" No No No below. Of those which could be detected with both short wave and long wave ultraviolet radiation after i on Fluorescent Pigment detonation, the short wave radiation produces more xxxvil 2210 Yes Yes Yes easily detectable results. v a xxxvm.

XL 2330M Yes Yes Yes 40 Jn;g.s. M l

" Overs From 200 Mesh (USSS) Screening SHORT WAVE LONG WAVE (ABOUT 1500 to 2600A) (ABOUT 3600 to 3700A) Example Type Before After Before After Detonation Detonation Detonation Detonation Mn; 65-1 15 Yes Yes Yes No Hel econ Phos horescent Pi ment XIII 2383 Yes Yes Yes Yes XIV 2315 Yes Yes Yes No XV 2330 Yes Yes Yes Yes XVI 2330* No No No No Helecon Fluorescent-Pi ment I 2 1 es Yes Yes New XVIII 2330 Yes Yes Yes Yes Unwed V l it Overs From 200 Mesh (USSS) Screening EXAMPLES XIX XL EXAMPLES XLI XLV Samples of the following phosphors are added to Examples XII to XVIII,the luminescent materials are samples of powder and formedinto one-and-one-fourth sprinkled onto the shell of an explosive which is then inch by eight inch stick, and the resulting mixes are detcoated with a polyurethane clear finish. The results are onated in the vicinity of a steel plate dirtied with the 5 more easily detected under aide of microscope than following contaminants, with results, using a X I00 miwhen the phosphors are mixed with the explosive powcroscope as indicated below under short wave ultravioder, as in Examples XII XVIII.

let light:

SHORT WAVE LONG WAVE (ABOUT 1500 to 2600A) (ABOUT 3600 to 3700A) Example Type Before After efore After Detonation Detonation Detonation Detonation Radelin Phos hor XII Zn giltcate;

Mn; GS-l l5 Yes Yes No Helecon Phos horescent Pi ment XL" 2304 Yes Yes Yes XLlll 2315 Yes Yes Yes XLlV 2330* No No No Helecon Fluorescent Pi ment es Yes Yes XLVl 2330* Yes Yes Yes Unfired e ite .299, MM ,959

EXAMPLES XLVlI L Limestone is ground to 40 mesh (ULS. Sieve Series) mixed to a two weight percent level with a 4OWR powder into a one-and-one-fourth inch byeight inch stick, and exploded in a barrel and onto brick, steel plate and wood in the barrel. The luminescent material can not be detected under short or long wave ultraviolet radiation by eye following detonation. It appears that the limestone deflected off the harder materials such as steel and embedded within the shorter materials such as wood.

EXAMPLES L Llll Brown willemite is ground to +20 40 mesh (U.S. Sieve Series), mixed to a two weight percent level with 4OWR powder into a one-and-one-fourth inch by eight inch stick, and exploded in a barrel and onto brick, steel plate and wood in the barrel. The luminescent material is detectable in every instance by eye upon short or long wave ultraviolet excitation, with the luminescent material being more easily detected on barrel pieces and steel plate.

EXAMPLE LIV a Q twq rare. arths. sma ym nitr and y prosium nitrate, are mixed with 4OWR powder at the 200 part per million by weight level and tested as in Example Il. Following explosion of the mixture, the detected particles are too sparse for positive identification by the unaided eye.

The above examples illustrate the invention and show its breadth. Although the present invention has been described with reference to preferred embodiments and specific examples, numerous modification could be made, and still the result would be within the scope of the invention.

What is claimed is:

1. An explosive device comprising an explosive material and a luminescent material making-up less than about 2 percent by weight of the explosive device such that prior to detonation of the explosive device the luminescent material is not readily detectable under ambient light while following detonation of the explosive device the luminescent material is detectable upon excitation by a nonvisible excitation radiation.

2. An explosive device of claim 1 in which the luminescent material is present in an amount of from about 0.025 to about 2 percent,

3. An explosive device of claim 2 in which the luminescent material is present in an amount of from about 0.05 to about 1.0 percent by weight.

4. An explosive device of claim 1 in which the luminescent material is added to explosive material in the explosive device.

5. An explosive device of claim 1 in which the luminescent material is coated on the exterior of the explosive device. i

6. An explosive device of claim 5 in which the luminescent material is sprinkled onto the exterior of the explosive device and covered with a polyurethane clear finish.

7. An explosive device of claim 1 in which the luminescent material is incorporated into the container of the explosive.

8. An explosive device of claim 1 in which the lumisubsequent to detonation of the explosive device ra-- diating the area surrounding the detonation with the non-visible excitation radiation;

detecting the electromagnetic emission of the luminescent material in the radiated area; and associating the electromagnetic emission with the explosive device source. I

11. The method as claimed in claim 10 in which the luminescent material is added by mixing luminescent material with explosive material and forming the mixture into the explosive device. v

12. The method of claim 10 in which the luminescent material is incorporated in the explosive device by depositing luminescent material on the exterior of the explosive device.

13. The method of claim 12 in'which the luminescent material is sprinkled onto the exterior of the explosive device and covered with apolyurethane clear finish.

14. The method of claim 10in which the luminescent material is less than about 2 percent by weight of the explosive device.

cent by weight of the explosive device.

16. The method of claim 15 in which the luminescent material is in an amount of from about 0.05 to 1.0 percent by weight of the explosive device.

17. The method of claim 10 in which subsequent to detonation of the explosive device the area surrounding the detonation is radiated with ultra-violet radiation.

18. The method of claim 10 in-which the luminescent material is phosphorescent.

19. The method of claim 10 in which the luminescent material is fluorescent.

20. An explosive device of claim 1- in which at least two luminescent m tsr jlsaasswpleyee.

21. An explosive device as claimed in claim 1 in which the average particle size of the luminescent material is about 40 to 2000 microns.

22. An explosive device of claim 16 in which the average particle size of the luminescent material is about 50 to 1000 microns.

23. A method of identifying the source of an explosive device having incorporated therein a luminescent material which upon excitation by a non-visible excitation radiation has a known electromagnetic emission uniquely associated with the explosive device source, said method comprising:

subsequent to detonation of the explosive device radiating the area surrounding the detonation with the non-visible excitation radiation; detecting the electromagnetic emission of the luminescent material in the radiated area; and associating the electromagnetic emission with the explosive device source.

Notice of Adverse Decision in Interference In Interference No. 99,183, involving Patent No. 3,835,782, G. L. Griffith and D. W. Edwards, PRODUCT AND METHOD, final judgment adverse to the patentees was rendered Oct. 28, 197 6, as to claims 1, 2, 3, 4:, 8, 9, 20, 21 and 22.

[Oyficz'al Gazette Februm'g/ 1, 1977.]

UNITED STATES ATENT OFFICE CERTIFICATE OF CORRECTION PATENT NO. 1 3,835,782 DATED September 17, 1974 INVENTOR(S) GEORGE L. GRIFFITH and DONALD W. EDWARDS it is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

IN THE CLAIMS:

Claim 22, Column 10, line 1, "device of claim 16'', should be device of claim 21 Signed and Sealed this A rresr:

RUTH C. MASON C. MARSHALL DANN AI/csring Oj'ji'rer Commissioner of Purenrs and Trademarks

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US3474730 *Sep 20, 1967Oct 28, 1969Apache Powder CoLuminescent coated detonating fuse
US3712222 *Mar 12, 1970Jan 23, 1973Brunswick CorpPyrotechnic fuse
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3991680 *May 15, 1975Nov 16, 1976The United States Of America As Represented By The United States Energy Research And Development AdministrationTagging explosives with sulfur hexafluoride
US3993838 *Mar 3, 1975Nov 23, 1976The United States Of America As Represented By The Secretary Of The InteriorWax or plastic coated phosphor grains
US4013490 *Aug 12, 1974Mar 22, 1977Westinghouse Electric CorporationPhosphor identification method, particularly adapted for use with explosives, for providing a distinctive information label
US4018635 *Mar 27, 1973Apr 19, 1977Westinghouse Electric CorporationPhosphor combination, particularly adapted for use with explosives, for providing a distinctive information label
US4053433 *Feb 19, 1975Oct 11, 1977Minnesota Mining And Manufacturing CompanyMethod of tagging with color-coded microparticles
US4390452 *Aug 20, 1979Jun 28, 1983Minnesota Mining & Manufacturing CompanyForming sheets of uniform thickness, coding and comminuting; tagging
US4431766 *Nov 5, 1979Feb 14, 1984Stauffer Chemical CompanyTrace amounts of zirconium silicate
US4867813 *Aug 26, 1988Sep 19, 1989W. R. Grace & Co. - Conn.Salt-phase sensitized water-containing explosives
US5864084 *Apr 16, 1997Jan 26, 1999American Promotional Events, Inc.For a firework device
US7055438 *Dec 2, 2003Jun 6, 2006The United States Of America As Represented By The Secretary Of The ArmySystem and method for a flameless tracer/marker utilizing heat marking chemicals
US7720254Mar 13, 2007May 18, 2010Smi Holdings, Inc.Automatic microparticle mark reader
US7831042Mar 13, 2007Nov 9, 2010Smi Holdings, Inc.Three-dimensional authentication of microparticle mark
US7885428Dec 18, 2009Feb 8, 2011Smi Holdings, Inc.Automatic microparticle mark reader
US8033450Mar 13, 2007Oct 11, 2011Smi Holdings, Inc.Expression codes for microparticle marks based on signature strings
US8223964Oct 6, 2010Jul 17, 2012Smi Holdings, Inc.Three-dimensional authentication of mircoparticle mark
US8704158Apr 17, 2009Apr 22, 2014Qiagen Lake Constance GmbhFluorescence standard, and the use thereof
DE10350024A1 *Oct 27, 2003May 25, 2005Metallwerk Elisenhütte GmbHPatrone mit nachweisrelevanter Dotierung
EP2395344A2 *Apr 17, 2009Dec 14, 2011Qiagen Lake Constance GmbHFluorescence standard and use of same
WO2001019758A1 *Sep 15, 2000Mar 22, 2001Dynamit Nobel GmbhMunition
WO2008138044A1 *May 9, 2008Nov 20, 2008Mark BrownExplosive tagging
Classifications
U.S. Classification250/302, 149/123, 250/459.1, 102/282, 102/283, 102/314, 149/21
International ClassificationG09F3/00, C06B23/00
Cooperative ClassificationC06B23/008, Y10S149/123, G09F3/00
European ClassificationG09F3/00, C06B23/00G
Legal Events
DateCodeEventDescription
May 3, 1982ASAssignment
Owner name: BARCLAYS/AMERICAN/BUSINESS CREDIT, INC., 111 FOUND
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:TROJAN CORPORATION;REEL/FRAME:003984/0057
Effective date: 19820122
Mar 24, 1982ASAssignment
Owner name: TROJAN CORPORATION, P.O. BOX 310 SPANISH FORK, UT.
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:INTERNATIONAL MINERALS & CHEMICALS CORPORATION;REEL/FRAME:003962/0694
Effective date: 19820122
Mar 24, 1982AS02Assignment of assignor's interest
Owner name: INTERNATIONAL MINERALS & CHEMICALS CORPORATION
Effective date: 19820122
Owner name: TROJAN CORPORATION, P.O. BOX 310 SPANISH FORK, UT.