DE2343774C3 - Procedure for labeling individual production units of solid and semi-solid substances - Google Patents

Description

The invention relates to a method for identifying individual production units of solid and "i semi-solid substances, by adding these chemically labeled glass microspheres from 1 to 250 μΐη size, wherein the chemical labeling of the microspheres in the modification of the composition and concentration of inkorpo- in the glass microspheres v , rated chemical compounds.

For a long time there has been a need to assign individual production units to a substance in this way indicate that each individual production unit can later be identified again, especially w> after shipping for trade and use.

Chemically labeled glass microspheres of 30 to μπι size are fixed for the identification and semi-solid products, other than metals, verwen- ti ^r) det been (Chem. Eng. News, 50, no. 5, 20 [1972) and "Chemistry for laboratory and plant ", Vol. 23, 1972, No. 6, p. 269). By modifying the composition and concentration of the compounds contained in the glass spheres, a wide range of coding options are possible. The microspheres can e.g. B. pharmaceutical preparations, dyes, plastics and paper can be added.

The invention is based on the object of identifying methods of the type mentioned at the beginning to improve that a reliable identification of the substances is possible after their destruction, for example, by heat or mechanical action.

According to the invention, the object is achieved by that chemical compounds with the following metal components are selected for marking the glass microspheres:

Aluminum manganese Antimony molybdenum Arsenic neodymium Barium nickel Bismuth niobium Cadmium potassium Calcium praseodymium Cerium silicon Chrome silver Cobalt sodium Copper strontium Gallium tantalum Germanium tin Indium titanium Iron tungsten Lanthanum Vanadium

Lead tin

Lithium zirconium

magnesium

that at least three metals are selected for one type of glass microsphere, that the chemical compounds are selected so that each metal makes up at least 0.1% by weight of the weight of each glass microsphere and that the glass microspheres have a density of more than 3 g / cm ³ and survive ashing at 400 to 500 ° C.

A small number of identification elements with a few different concentrations enables a very large number of individual quantities or items to be coded. For example, can an inventory of microspheres can be put together in such a way that a normal glass is used as a support material with the addition of ten selected elements three different concentrations is used, e.g. B. 0.5% by weight, 1% by weight and 2% by weight. Microspheres from homogeneous melts produced by conventional glass bead making processes could be provided with 1048575 different codes so that each item is coded Glass microbeads is different from the rest of the items.

The differently coded microspheres can be used in each individual production unit or item can be added to a substance and can be easily analyzed later when recovering, see above that on the basis of the records made, the production unit concerned is accurate can be identified. The substance containing the encoded microspheres does not need to be recovered. After the destruction of the substance only a coded microsphere needs to be left for complete and accurate identification to enable.

The diameter of individual microspheres can be be only 1 um, but should not be more than 250 μσι, so that in a given Substnz only a small percentage by weight of the microspheres needs to be entered in order to achieve sufficient Number of microspheres to be obtained so that at least one microsphere is certain to be recovered can be. To mark and identify explosives, microspheres with a Diameters between 20 and 100 µm are used and could easily be found out from the residues after the explosion by their shape.

The microspheres should have a density of at least

3 g / cm ³ so that they can be excreted from dirt and normal debris, which are generally of much lower density.

The microspheres should be made of glass or a glass-like material so that they are impermeable to or are not influenced by the supporting substance or the environment to which the microparticles are exposed are.

The identification elements used are preferably those which are not contained in the carrier substance are. On the other hand, elements contained in the carrier substance can also be used for identification purposes be used. For example, you can use any microbeads supplied to a dynamite maker will have a certain carrier substance to the one dynamite generator from other manufacturers to distinguish.

Each identification element should be added in an amount of at least 0.1% of the total weight To do effective analysis with an electron microprobe analyzer to be able to carry out> which instrument is currently preferred. The final analysis will only look at the item itself determined, and its occurrence in the microparticle as a free element, its oxide or another compound of the element is not distinguished, -in

Since the performance of the analysis instrument is limited in practice, suitably the concentration levels are to divorce an element from one item to the next item microspheres by a factor of at least 1.5 and preferably 2 butts 4 ^r>. For the purpose of simplifying the analysis, the lowest concentration level for each element can be the same, for example 1%.

If microspheres from a batch are added to a single production unit of a substance, to this process is recorded in a recording for the purpose of later evaluation. These records can also contain samples of each item, so that if necessary the analysis of the recovered microparticle «can be confirmed.

example 1

Fine powders of metal oxides such as MoO ₂ , La ₂ O ₃ , CeO ₂ and WO ₃ were weighed to produce metal oxide levels of 18.0%, 31.6%, 33.3% and 17.1%, respectively , which resulted in integer ratios of 1: 2: 2: 1 for the individual metals themselves. The mixed together metal oxides were thoroughly with Ba0-TiO ₂ -glass beads in the ratio of b ^r>

4 grams of metal oxide mixture mixed into 76 grams of glass beads. This mixture was in one Crucible at about 1400 ° C in a gas heated one.

Kiln fired to a homogeneous melt. The resulting Melt was formed into spherical, sand-colored microparticles, cooled and sealed sieved in a thickness range of 44 to 125 microns. These spheres are then appropriate Substrates, as described in more detail in Example 5, added.

Example 2

Using the metals Zn, Sr, Cd and Nd, a second composition was prepared with an integer ratio of their oxides, but in the case of strontium this was added as carbonate. The metal oxide-carbonate mixture was weighed out to contain 44.2%, 28.6%, 19.3% and 9.9% of the respective compounds, and the materials well mixed with each other became BaO-TiO _{2 glass beads} added. Spherical microparticles were produced from the resulting mixture as described in Example 1, clear microbeads having a diameter of 37 to 149 micrometers with a whitish mass being produced.

Example 3

A third composition was prepared using MnO ₂ , Co ₂ O ₃ , NiO and SnO in weighed proportions of 26.5%, 11.8%, 42.7% and 19.0%, respectively, with one between the metals integer ratio of 2: 1: 4: 2 was created. The metal oxide mixture was thoroughly mixed with BaO — TiO ₂ -GIaS beads, and spherical microparticles were produced from this mixture, as described in Example 1. Clear microbeads, black in color in the mass, were produced from this composition.

The density of the microspheres according to Examples 1, 2 and 3 was greater than 3.3 grams / cm '.

Example 4

A clear, colorless solution was prepared from HOg water, 42.7 g aluminum acetate with a content of 19 g 3 Al ₂ O ₃ B ₂ O _{3 with stirring.} With continued stirring, the following was added:

a) 1.44 g of MnCl ₂ · 4H ₂ O dissolved in 10 g of water,

b) 0.474 g of Cd (CH ₃ COO) ₂ , dissolved in 10 g of water, and

c) 1.064 g CeCl ₃ 7H ₂ O, dissolved in 10 g water, a clear, colorless solution containing 2% Mn, 1% Cd, 2% Ce and 95% 3Al ₂ O ₃ · B ₂ O _{3 being} obtained became. Of this solution, 80 grams was slowly poured into 3.5 liters of 2-ethylhexanol at room temperature while the mixture in a 4 liter beaker was stirred at 800 rpm by means of an air motor driven paddle mixer. This stirring was continued for 20 minutes to extract water from the solution microdroplets in the alcohol. The wet alcohol was removed by filtering through filter paper to give transparent, colorless particles with a diameter of 20 to 100 μm, which were dried in an oven at 90-100 ° C. for one and a half hours to remove the remaining alcohol, after which the particles were placed in a porcelain crucible in an electric furnace. The temperature in the oven was increased to 600 ° C for an hour and a half and then increased to 850 ° C, which temperature was another

Was maintained for an hour. The product obtained consisted of 7.3 g of light brown, translucent Microbeads.

Example 5

Microspheres with a higher density than described in Example 4 were produced using a carrier material made of ZrO ₂ : SiO ₂ (1: 1). 58.75 g Zirkoniumazetatlösung were added: 0.72 g MnGl ₂ - 4H ₂ O, 0.95 g Cd (CK ₃ COO) ₂ · 2H ₂ O and 0.53 g CEQ ₃ 7H ₂ O. The salts dissolved easily to form a clear, colorless solution to which an aqueous dispersion of approximately pH 1 was added, with stirring, made up of 21 g of colloidal silica plus 10 drops of concentrated hydrochloric acid. Although the resulting dispersion was somewhat cloudy, it was colorless. This dispersion was added to 3.5 liters of 2-ethylhexanol at room temperature using an injection syringe, taking advantage of its inherent gravity. Similar to Example 4, the mixture was stirred at approximately 800-1000 rpm. The addition required about a minute while stirring for 20 minutes to allow the alcohol to remove water from the microdroplets. The wet alcohol was removed by filtering through filter paper, whereby clear and colorless microbeads with a diameter of 20-120 μm were obtained, which were then dried at 90-100 ° C for one hour and placed in a porcelain crucible in an electric oven, in which a temperature of 800-820 ° C was maintained for 3 hours. The microbeads were then cooled. Approximately 20 grams of lavender brown and clear microbeads were obtained. J5

Other coded microbeads were produced with different carriers such as titanium oxide, aluminum oxide and alumina borosilicate using those described in Examples 4 and 5 Procedure.

The encoded microspheres according to Examples 1-5 are in single quanta or lots manufactured and stored, ao that all microspheres of a quantum or item have the same coding. Microspheres from any Production items can then be a production unit added to a substance for the purpose of coding. You microspheres can z. B. a paper that can be added for banknotes, securities, promissory notes, documents or labels is used, furthermore, the microparticles can be adhesives, coatings, sealants, plastics, Resins, foams as well as drugs, narcotics, medical preparations, explosives, such as gunpowder and dynamite, dyes, lacquers, enamels, pigments, waxes and other manufacturing goods can be added.

In Examples 6-8 below, three cases are described in which encoded microspheres according to Examples 1-5 were used to identify a particular substance.

Example 6

Microspheres prepared according to Example 1 were added to dynamite in a weight ratio of one part of identifier to 1000 parts of dynamite. After detonation of 0.45 kg of dynamite, approximately 1.5 kg of rubble and debris was collected and removed from the blasting crater. The collected debris was then washed with tap water to separate microspheres that adhered to larger objects, after which debris approximately greater than 5 mm in diameter was removed by hand. The remaining explosion debris was then thoroughly dried. A representative sample (approximately V ₅ to ¹ Z _{4 of} the total debris collected) was then sieved using a sieve with 250 μm mesh and deposited on glossy paper in order to be able to remove relatively large debris. The fines were then again sieved through a 150 mesh screen on glossy paper. Approximately 10 grams of the fines were placed in a beaker and wetted with acetone. The wetted fines were repeatedly washed with tap water and then washed with acetone, followed by the Fine particles were dried and poured into a separation tube made of a deep-drawn centrifuge tube with a volume of 15 ml and _{containing 8 to 10 ml of diiodomethane (Ch 2} I ₂ ) with a density of 3.3 g / cm ³ The sludge consisting of the fines and the solvent was carefully stirred for about 10 minutes above the constriction of the separation tube with a tapered spatula, so that the dense particles (with a density of more than 3.3 g / cm ³ ) are through the contents of the The tube was immersed in an ice bath to remove the solvent (Melting point 5-7 ° C) to freeze. The separation tube was broken off at the constriction, and the smaller part of the tube with the denser fine particles was placed in a small beaker. Approximately half of the molten solvent was removed with a serological pipette, and a permanent magnet was moved up the side of the small tube to remove magnetic particles. The remaining dense fines and the remaining solvent were poured into a 5 cm petri dish, and the CH ₂ I ₂ was removed by repeated washing and decanting with acetone. The dense Feip parts were then carefully dried and examined under the stereo microscope and the presence of a number of microbeads determined. One of these microbeads was removed with a sharp dissecting needle and placed on a sheet of glass. The microbead was then analyzed using an electron microprobe analyzer. The results of the qualitative and quantitative analysis were consistent with the records for the dynamite that had been detonated.

Example 7

To a quantity of 30 g of alkyd automotive gloss paint was added 0.03 g of microbeads (which had been produced according to Examples 4 and 5) which contained Co, Ni and Sr as coding elements in the integer ratios of 4: 2: 1. The coded color was shaken thoroughly by hand for several minutes in a covered glass jar with a capacity of 120 cm ^3. A ratio of 1: 540 was obtained for the identification agent to the gloss varnish on the basis of 54% solids content.

Three out of four previously cleaned and dried

Plates measuring 50 X 10O X 0.56 mm made of galvanized sheet metal were fitted with a 6 mm wide masking tape divided across two equally large areas. The one half of each of the three subdivided plates was coded with a paint brush and the other with a paintbrush Half coated with the original uncoded lacquer. The fourth plate received a complete one Painted with coded varnish and was placed near the end of a piece of wood with the dimensions 36 x 5 X 1.3 cm firmly glued on. All of the panels with the paint application were made on the Air dried at room temperature for one hour and then dried again for another Hour under irradiation with a 300 watt infrared heating lamp at a distance of 76 cm.

When looking at the plates provided with the paint application, they could see with the naked eye no differences are found in appearance. At 60x magnification, a -'o Examine with a dissecting needle the presence of microbeads in the coded varnish effortlessly to be established. The plate attached to the piece of wood was violently struck against a metal button, to simulate a car accident. A inspection of the metal button revealed the transmission of lacquer fragments in which the presence of microbeads can be determined under the microscope could.

A separate microbead was after that in the jo Example 6 was analyzed and found to be one with Co: Ni: Sr (4: 2: 1) encoded microbead from the encoded lacquer.

Example 8

32 rounds of ammunition for the 9-mm-Walther Antebellum pistol P-38 were unloaded, and the amount of 11.2 g (175.2 grains) of the collected powder was mixed with 12.5 mg of microbeads according to Example 3 -w mixed. A powder to identification agent ratio of 910: 1 was obtained. That with The powder thoroughly mixed with the microbeads was then returned to the previously emptied cartridge cases filled, after which shot tests were carried out.

A cardboard cylinder was tightly stuffed with sawdust and sealed with a cardboard disk. At this A piece of beef was attached to a cardboard disc and covered with a light-colored piece of linen, creating a clothed target made of flesh was roughly modeled. From a A first cartridge with the powder-microbead mixture was placed on the horizontally suspended target fired. Before the second round was fired, the The piece of meat, the linen, and the cardboard washer were renewed, and this sequence was for a total of five shots repeated. The pierced pieces of meat, pieces of linen and cardboard were individually in polystyrene bags packed and labeled. The same was done with the cleaning rags that were used for cleaning of the pistol barrel were used after the investigations, with a pack of cleaning rags One package contained a cleaning agent and oil, while the second package only contained dry cleaning wool or rags contained.

The first bullets were examined under a stereo microscope at 60x magnification, microbeads were found at the base of each bullet. As in example 6 described, analyzed, which resulted in a correspondence with the coding. Microbeads were also found in every fired cartridge case.

The combustible objects were incinerated individually at 400-500 ° C in an electric muffle furnace, the oxygen was supplied in an amount of about 42 liters per hour. The resulting Ash samples were poured through a sieve with 150 µm openings, from each sample then isolated microbeads and analyzed in the manner described, as described in Example 6, wherein a match with the original code has been established.

Claims (1)

Claim: A method for identifying individual production units of solid and semi-solid substandard ~~> zen by these chemically labeled glass microspheres of 1-260 added to size, wherein the chemical labeling of the microspheres in the modification of the composition and concentration of the glass microspheres inkor- i " porated chemical compounds, characterized in that chemical compounds with the following metal components are selected for marking the glass microspheres: Aluminum manganese Antimony molybdenum Arsenic neodymium Barium nickel Bismuth niobium Cadmium potassium Calcium praseodymium Cerium silicon Chrome silver Cobalt Sodium - ""> Copper strontium Gallium tantalum Germanium tin Indium titanium Iron tungsten w Lanthanum Vanadium Lead tin Lithium zirconium magnesium b) that for one type of glass microspheres j> selects at least three metals, c) that one chooses the chemical compounds so that each metal at least 0.1% by weight of the weight of each glass microsphere, and κι d) that the glass microspheres have a density of more than 3 g / cm ³ and survive ashing at 400-500 ° C.