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Magnetic fingerprint revealing powder and preparation method and application thereof

A magnetic powder and fingerprint technology, applied in applications, medical science, sensors, etc., can solve problems such as endangering the health of operators, harsh conditions for powder use, and lack of high adaptability, and achieves the promotion of industrial production and high temperature stability. , the effect of stable nature

Active Publication Date: 2016-02-17
TONGJI UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the preparation process of this method is complicated, not environmentally friendly, and the cost is high, which is not conducive to its widespread use.
[0012] The above-mentioned patents have prepared various fingerprint display materials by different methods, but there are still the following four significant disadvantages: (1) The preparation method is complicated and the process requirements are harsh, which greatly limits its application in industry; (2) The preparation Toxic substances are introduced to varying degrees during the process, which endangers the health of operators
(3) The use conditions of fingerprint display powder are harsh and do not have the conditions of high adaptability
[0013] To sum up, there is currently a lack of fingerprint display magnetic powder materials with simple preparation process, environmental protection, high sensitivity and high adaptability on the market.

Method used

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  • Magnetic fingerprint revealing powder and preparation method and application thereof
  • Magnetic fingerprint revealing powder and preparation method and application thereof
  • Magnetic fingerprint revealing powder and preparation method and application thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0038] In this embodiment, the chemical formula of the magnetic powder showing fingerprints is Fe 50 (BN) 50 .

[0039] The preparation method of above-mentioned fingerprint revealing magnetic powder is as follows:

[0040] (1) prepare commercially available Fe powder and BN powder;

[0041] (2) The purity of the Fe powder is 99.5%, the particle size is 35 μm, the purity of the BN powder is 99.5%, the particle size is 10 μm, and the ingredients are made according to the composition atomic percentage;

[0042] (3) Place the raw materials weighed in step (2) in a ball mill, the ball-to-material ratio is 10:1, the ball milling process parameters are rotating speed: 200 rpm, time: 90 minutes and 400 mesh size sieve;

[0043] (4) Put the magnetic powder mixture obtained in step (3) in an oven for 60 minutes.

[0044] (5) Detect the effect of fingerprint display on the above-mentioned obtained, print the fingerprint on the glass sheet with your fingers, and absorb Fe with the tip ...

Embodiment 2

[0047] In this embodiment, the chemical formula of the magnetic powder showing fingerprints is Fe 50 (BN) 50 .

[0048] The preparation method of above-mentioned fingerprint revealing magnetic powder is as follows:

[0049] (1) prepare commercially available Fe powder and BN powder;

[0050] (2) The purity of the Fe powder is 99.5%, the particle size is 35 μm, the purity of the BN powder is 99.5%, the particle size is 10 μm, and the ingredients are made according to the composition atomic percentage;

[0051] (3) Place the raw materials weighed in step (2) in a ball mill, the ball-to-material ratio is 10:1, the ball milling process parameters are rotating speed: 300 rpm, time: 60 minutes and 400 mesh size sieve;

[0052] (4) Put the magnetic powder mixture obtained in step (3) in an oven for 60 minutes.

[0053] (5) To detect the effect of fingerprints produced above, print the fingerprints on the glass sheet with your fingers, then immerse the glass sheet in water for 30 ...

Embodiment 3

[0056] In this embodiment, the chemical formula of the fingerprint revealing magnetic powder is Co 66.7 (BN) 33.3 .

[0057] The preparation method of above-mentioned fingerprint revealing magnetic powder is as follows:

[0058] (1) prepare commercially available Co powder and BN powder;

[0059] (2) The purity of the Co powder is 99.5%, the particle size is 23 μm, the purity of the BN powder is 99.5%, the particle size is 10 μm, and the batching is carried out according to the composition atomic percentage;

[0060] (3) Place the raw materials weighed in step (2) in a ball mill, the ball-to-material ratio is 10:1, the ball milling process parameters are rotating speed: 300 rpm, time: 60 minutes and 600 mesh size sieve;

[0061] (4) Put the magnetic powder mixture obtained in step (3) in an oven for 60 minutes.

[0062] (5) Detect the fingerprint display effect of the above-mentioned obtained, print the fingerprint on the desktop surface with your fingers, and absorb Co wi...

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Abstract

The invention belongs to the technical field of fingerprint identification and relates to magnetic fingerprint revealing powder and a preparation method and application thereof. The magnetic fingerprint revealing powder is composed of magnetic powder and developing powder, and a chemical formula of the magnetic fingerprint revealing powder is Ma(BN)b, wherein M refers to the magnetic powder selected from at least one of Fe powder, Co power, Ni powder, Fe3O4 or Fe78Si9B13 amorphous powder, B refers to the developing powder, a and b refer to atom percentage contents of corresponding elements, a is larger than or equal to 50 and smaller than or equal to 88.9, b is larger than or equal to 11.1 and smaller than or equal to 50, and the amount of a and b is 100. Compared with the prior art, the magnetic fingerprint revealing powder not only has the advantages of easiness in raw material acquisition, simplicity in preparation, stability in performance, easiness in storage and the like but also has no toxic or side effect on users and has a most prominent advantage that high-precision reveal of fingerprints on the surfaces of various objects in dry or humid environment can be realized. Therefore, the preparation process is simplified on the premise of high revealing precision of the magnetic fingerprint revealing powder, and the magnetic fingerprint revealing powder is widely applicable to various complicated environments and has an extremely high practical application value.

Description

technical field [0001] The invention belongs to the technical field of fingerprint identification, and in particular relates to a magnetic powder for displaying fingerprints, a preparation method and application thereof. Background technique [0002] Fingerprints have the characteristics of being different from person to person, basically unchanged, leaving traces when touched, and identifying a person. Therefore, the discovery, extraction and identification of fingerprints have important practical effects on security and criminal investigation. [0003] Since 1877, the French doctor Aubert used silver nitrate to visualize fingerprints on paper, which opened a multidisciplinary fingerprint visualization science that comprehensively utilizes physics, chemistry, and biology. After more than 100 years of development, fingerprint display methods mainly include: physical attachment, chemical reaction, physical and chemical action and laser display method. At present, the powder...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): A61B5/1172
CPCA61B5/1172
Inventor 陆伟向震牛俊超王韬磊夏卡达
Owner TONGJI UNIV
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