DD285609A5 - MEANS FOR MARKING SOLIDS SURFACES - Google Patents

Abstract

The invention relates to novel means for marking solid surfaces on the basis of luminescent inorganic compounds and their mixtures, which are characterized by a simple and fast, on-site handling, a high identification value and a reliable detectability in UV irradiation, a good adhesion to a variety Substrates and a high long-term stability, are economical and inexpensive to produce and have physiologically acceptable (non-toxic) properties. The mixtures used for marking are distinguished, in particular, by the fact that they themselves have only a slight inherent faintness in the visual light. They are particularly suitable for the marking of criminally and medically relevant objects and living beings. Individual luminescent particles of different colors can be detected microscopically or, if required, by luminescence microspectroanalysis and z. B. for the comparative criminal investigation and identification be used. {Marking agents; luminophores; inorganic salts; UV excitation; mixtures; activated Zn / Cd salts; Identification; Comparative study}

Description

Field of application of the invention

The invention relates to a means for marking solid surfaces, which is particularly applicable for comparative investigations and identifications as well as for the purpose of the recognition of objects and living beings.

Characteristic of the known state of the art

Marking agents have long been widely used in scientific and forensic fields (DE 2557419, DE 2433628, DD 208369, Frei and Meier, Krimin 13 (1959) 514, Fröhling, Krimin. 7 [1953] 66, Widmann and Schade, Krimin. 14 [1940] 82).

Particularly frequently, luminescent compounds (luminophores) are used for marking purposes under UV irradiation. Of the large number of known organic and inorganic luminophores (DE 2938558, DE 2660890, OE 2356020. DE 2906505, DE 3417626, ALDRICH catalog 1988/89) have in particular those on an organic basis, such as. B.

Metal complex compounds of 8-oxyquinoline (oxinates) (Stelzer, Bd.2, Berlin 1979, 103) or fluorescent dyes of the xanthene, triphenylmethane, azine and naphthene type (Widmann and Schade, Krimin. 14 [194Oj 82, Gerdau, Krimin. 11 [1957] 441) found preferred interest for labeling purposes.

These markers are applied in powdered or liquid form, as an ointment emulsion or by spraying on the substrates to be marked.

The main drawbacks of these markers used in practice are, above all, their presence in many areas of social life, e.g. in medicine (disinfectants), dyes (colorants), cosmetics (lipsticks), and office chemicals (inks, ballpoint pen pastes, copying pens, etc.), which put into question secure and unequivocal evidence of origin identity. In addition, some of these markers z.T.

significant deficiencies in their toxic properties (e.g., oxinates), low light fastness and resistance to aging (e.g., fluorescein dyes), as well as conspicuous inherent color under daylight conditions (e.g., triphenylmethane dyes).

Other labeling methods are known which rely on the use of aqueous solutions of pH-dependent organic indicator dyes (Stedry, Krimin. 14 [1960J 204].

Due to the low detection sensitivity and cumbersome handling of these dyes their applicability remains limited to specific areas.

Other methods include substantive tagging agents (Stedry, Krimin. 14 (1960) 204, Widmann and Schade 14 [1940] 82, Martin, Krimin. 18 [1964] 75 /, z. As ninhydrin or silver nitrate, for use, which after some time, when they react with skin or secretions, give a characteristic coloration in daylight. However, they do not meet the requirements

quick checks.

To increase the evidential value, substantive markers are also used in combination with organic dyes. In this mixture, however, they are subject to substrate and environmental influences dependent chemical conversion processes, so that for these and the above reasons their use can be made only in limited cases.

Overall, the state of the currently available marking agent can not satisfy, so that is looking for suitable new material systems, which in addition to eint r specific evidence also have a higher identification value.

Object of the invention

The aim of the invention is to provide a novel means for marking solid surfaces, which ensures a high recognition rate.

Explanation of the nature of the r

The object of the invention is to develop labeling agents based on luminescent compounds which ensure a high recognition rate and a high identification value of the label. In addition, they should have a quick and easy visualization in UV light, a high luminous intensity and good adhesion to a variety of substrates, with toxic, carcinogenic and mutagenic effects in humans and animals are excluded.

The object is achieved by labeling agent containing a mixture of luminescent inorganic compounds.

It is particularly advantageous to use mixtures of activated salts of alkaline earths and / or their subgroup elements Zn and Cd, since these ensure a high recognition rate and a high identification value and also have good adhesion and long-term stability on a wide variety of solid surfaces.

As salts it is possible to use sulfides, phosphates, carbonates, silicates, borates, aluminates and oxides which are activated with Cu, Ag, Cr, Mn, Fe, Ce, Ti and / or Al.

In particular, because of their high luminance and high recognition rate associated therewith, as the luminescent inorganic salts, compounds listed below, consisting of Cu, Ag, Mn and / or ΑΙ-activated Zn, Cd or Zn / Cd salts, are preferably used -Sulfides, or mixtures thereof in a mixing ratio of 1: 9 to 9: 1 (m / m) used with a particle size distribution between 1 to 20mm, depending on the composition in blue 1-4, green 5-9, yellow 10-13 and / or red 14-16 spectral range emitting light.

(D (ZnSrAg) 0 <b <0.1 (2XZnSrAg, Al) 0 <c <0.1 (3) (Ca ₂ MgSiO ₆ = Ce) 0.3 <d <0.5 (4) ((Ca, Mg) ₂ SiO ₄ = Ti) 0.3 <e <0.5 (5) ((Zn ₁ - Cd ₁₁ ) SrCu, Al) (6X (Zn ₁ -CCd ₀ ) S = Cu) 0.5 <f <0.7 (7X (Zn ₁ - ^ Cd ₁ I) SrAg) 0.5 <β <0.7 (8) ((Zn ₁ _., Cd.) S: Ag, Al) 0.1 <h <0.2 O) (Zn ₂ SiO ₄ = Mn) 0.1 <i <0.2 (10) ((Zn _1. ,, Cd ₁ ) SrAg) 0.65 <j <0.9 (11X (Zn _1. ,,, Cd ₀ ) SrAg, Al) (12) ((Zn, - _{h, h} Cd) S: Cu) (13X (Zn ₁ - ;, Cd,) S: Cu, Al) (14X (Zn ₁ - ^ CdJ) S = Ag) (15) (Zn ₃ (PO ₄ J ₂ = Mn) (16XCd ₂ B ₂ O ₆ = Mn)

Among the blue light-emitting phosphors, it is preferable to use the luminophores 1-2 as a marker from the standpoint of the light-emitting diode. In the same way, preferably the luminophore 5 is used in the case of the green marking substances, preferably the luminophore 10 in the case of the yellow marking substances and preferably the luminophore 14 in the case of the red marking substances.

A particularly secure and unambiguous identification is achieved when the individual marking luminophores, each of which emits light of different wavelengths, are used in a mixture, preferably in a mixing ratio of 1: 1 (m / m). It is advantageous if the luminophore mixtures have a particle diameter size distribution of 1-20 μm, preferably 10 μm.

On the basis of characteristic fluorescent radiation emanating from the individual marker substances on UV excitation, a reliable identification is achieved, wherein the information content can be increased above all by a microscopic or fluorescence microspectral analysis of individual particles of (binary) substance mixtures.

Surprisingly, the inorganic salts of the invention over a long period of high luminous intensity and stability and adhesion to a variety Feststorfoberflächen, whereby a broad application of the marking salts containing these salts is ensured.

For marking objects and living beings, the marking agent is preferably applied as microparticulate powder by means of fine-hair brush or powder atomizer or as an ointment emulsion on the substrate to be marked. Their proof was still possible after several days. The used in powdered form markers are also ideal for marking indoor and larger terrain surfaces.

The production costs of the inorganic luminophores used are relatively low.

embodiments

example 1

With a binary marker substance mixture (mixing ratio 1: 1, m / m) of the chemical composition of ((Zn ₁ - |, Cdj) S: Ag); 0.65 <j <0.9) and ((Zn ₁ _ ₍ , Cd ₍ ) S: Ag); 0.5 <f <0.7) applied as a microparticulate powder, a banknote is prepared superficially and then by touched several people with their fingers.

The recognition rate in all subjects was 100%, after the characteristic red and yellow fluorescence color of the used marking substances of the indicated composition under UV irradiation (254 nm) could be detected.

Example 2

With a binary marker mixture (mixing ratio 1: 2, m / m) of the chemical composition (ZnSiAg) and ((ZnI-OfCdI ₁ ) SiCu ₁ Al); 0 <b <0.1), applied as a microparticulate powder, a piece of art made of white marble is prepared and then touched by several people with their fingers.

The recognition rate for all persons was 100%, after the characteristic blue and green fluorescence color of individual particles of the marker substances of the stated composition used in the mixture could be detected microscopically (magnification 1:25) under UV irradiation (254 nm).

Example 3

A binary labeling mixture (mixing ratio 1: 5, m / m) of the chemical composition ((Zn ₁ _j, Cdj) S: Ag, 0.65 <j <0.9) and ((Zn, _ ₍ , Cdi): Cu, Al), 0 <f <0.1), which is contained in an embedding agent (lanolin), is invisibly applied to the skin areas to be marked.

Under UV light, the skin mark is immediately visible by a reddish yellow fluorescence and can be detected for several days.

Claims (12)

1. means for marking solid surfaces, characterized in that it contains a mixture of luminescent inorganic salts. Second means for marking solid surfaces according to claim 1, characterized in that it contains a mixture of light of different wavelengths emitting salts. 3. means for marking solid surfaces according to claims 1-2, characterized in that it contains a mixture of activated salts of alkaline earths and / or their subgroup elements Zn and / or Cd. 4. means for marking solid surfaces according to claims 1-3, characterized in that it contains a mixture of activated Zn and / or Cd salts. 5. means for marking solid surfaces according to claims 1-3, characterized in that it contains a mixture consisting of activated Zn or Cd salts and a mixture of Zn and Cd salts. 6. means for marking solid surfaces according to claims 1-5, characterized in that the salts are sulfides, phosphates, carbonates, silicates, borates, aluminates and oxides. 7. means for marking of Feststoffoberflächen.nach claims 1-6, characterized in that the mixture of Cu, Ag, Cr, Mn, Fe, Ce, Ti and / or ΑΙ-activated ZnS and / or CdS. 8. surface marking agent according to claims 1-7, characterized in that it contains a mixture of microparticulate inorganic luminescent salts. 9. A means for marking solid surfaces according to claims 1-8, characterized in that it contains microparticulate inorganic luminescent salts having a particle diameter size distribution between 1-20μητι, preferably from 10 pm particles. 10. A means for marking solid surfaces according to claims 1-7, characterized in that it consists of a mixture of microparticulate inorganic salts and emulsifiers and / or builders. 11. Use of the agent for marking solid surfaces, characterized in that it can be used for marking of objects and living things. 12. A method for marking solid surfaces, characterized in that an agent according to claims 1-10 is applied to objects or living things.