Compositions: coating or plastic – Coating or plastic compositions – Marking
Reexamination Certificate
2001-05-10
2002-12-03
Klemanski, Helene (Department: 1755)
Compositions: coating or plastic
Coating or plastic compositions
Marking
C106S031010, C106S031160, C106S031020
Reexamination Certificate
active
06488750
ABSTRACT:
FIELD OF THE INVENTION
The present invention is directed to an inkless fingerprinting compound and method of making the same.
DESCRIPTION OF THE PRIOR ART
Although there are other methods of identifying individuals, it has become readily apparent that fingerprints provide a unique and absolute means of identification that does not require cooperation from the subject. Since fingerprints are archived they must be permanent and because they are often captured by an electronic camera, the preferred color of fingerprint images is black. Printer's ink, which contains carbon pigmentation, meets the requirements of image permanency and color, but it tends to smear on paper, requires time to dry, soils the skin and equipment, is skill intensive and time consuming to use. While carbon based inks have been formulated with small amounts of carbon pigmentation to reduce the staining problem (U.S. Pat. No. 5,395,444 and U.S. Pat. No. 5,919,292), such inks are not completely stain free.
To remove some or all of the negative aspects the prior art carbon based inks, a considerable amount of effort has been directed to the development of inkless fingerprinting systems which do not rely on carbon particles to form an image of the fingerprint ridge pattern. Inkless technology has traditionally been defined as a color forming chemical reaction, between at least two reagents, that occurs at the time of fingerprint development. The chemical reaction between the two (or more) reagents provides a permanent perceivable colorant product representative of a fingerprint ridge pattern on the recording medium. Current technology dictates that the two reagents remain isolated from each other until the fingerprint is to be taken.
Typically a nonstaining first reagent is applied to a person's fingertips and a second reagent, capable of reacting with the first reagent to produce the colorant product such as 8-hydroxyquinoline, is pre-applied to or inherent in the recording medium such as the paper or card receiving the print. The second reagent can also be inherent in the paper receiving the print. See U.S. Pat. No. 4,983,415. Also see U.S. Pat. Nos. 4,262,623 and 4,182,261, the contents of which are incorporated herein by reference.
While the state of the art inkless systems have achieved considerable commercial success, they have their own set of shortcomings in addition to the need for two separated reagents. U.S. Pat. No. 4,190,056 Tapper et al relates to a method of reacting iodide with starch added to a paper recording medium, which fails to produce a black image. U.S. Pat. No. 4,879,134 to Vassiliades et al, discloses a fingerprinting composition which utilizes a chromographic compound and a color developing compound in one solution. While the Vassiliades et al patent refers to the system as an inkless system it is more properly classified as a nonstaining system since as the patent points out the liquid vehicle for the composition “is a solvent for said chromogenic compound and reaction product”, i.e., the reagents react while in the solution, prior to being applied to the finger and paper substrate (Col. 2, lines 36-37). Furthermore, it is not apparent that the images produced by the method would be sufficiently permanent. Also, it is not believed that AFIS (Automatic Fingerprint Information System) scanners would be able to satisfactorily capture images produced using this method.
U.S. Pat. No. 4,699,077 to Meadows & Diamond relates to a method involving chemically treated paper, a method that necessitates the cost of custom coating paper and this coating has a limited shelf life and is degraded when exposed to light. U.S. Pat. No. 4,983,415 to Arndt et al relates to an inkless system in which the fingerprint is captured on a thermosensitive recording surface, but this surface is not available on paper suitable for fingerprint cards, it yellows in the presence of light, it can not be used on checks and other documents, and it is not as inexpensive as commonly available, ordinary paper. U.S. Pat. No. 4,262,623 to Smith III et al relates to a method of recording inkless impressions on plain paper. However, this invention is costly, the apparatus requires a source of high voltage electricity and is therefore limited in its scope of operations and the system requires a lengthy image development process which can emit an offensive odor.
There is a need for an inkless fingerprinting system which overcomes the disadvantage of the prior art inkless technology systems. To fulfill this need, I have developed a single inkless fingerprint compound, i.e., liquid, paste or soap (i.e., vicious liquid), which can be transferred from a self-dispensing pad, such as ceramic, plastic, etc., to a person's fingerprint area and then to an ordinary paper recording medium. The system does not require the use of reagents maintained in separate locations thereby eliminating the conventional two step inkless system, i.e., one reagent to be transferred by the fingertip to the recording medium and a second reagent impregnated or inherent in the recording medium. Further, unlike the Vassiliades et al system the reagents while maintained in a single container or dispensing pad are not allowed to react until the fingerprint is taken. I have found that the compound of my invention, through its interaction with moisture from the skin and/or the recording medium, rapidly forms a permanent, substantially dry, smear resistant and nonstaining perceivable colorant product of the ridge pattern representing the person's fingerprint.
SUMMARY OF THE INVENTION
In accordance with the present invention an inkless fingerprint compound for providing a permanent colorant product representing a person's fingerprint when applied to the person's fingerprint area and deposited onto a paper substrate includes a solvent, a color former, such as a transition metal salt compatible with the solvent, and a developer, such as 8-hydroxyquinoline and its derivatives, capable of reacting with the color former to form the colorant product. The compound further includes a sufficient amount of a chelating agent, such as a carboxylic acid, to substantially prevent the color former and developer from reacting while in solution to form the colorant product while permitting such reaction when the solution is applied to the finger of the person to be fingerprinted and deposited onto the paper substrate.
The inkless fingerprinting compound may be in the form of a liquid, paste or soap (i.e., viscous liquid) and may be dispersed via a conventional ink type pad made for example of ceramic or plastic or other material which does not react with the compounds ingredients. Examples of suitable dispensing pads are disclosed in U.S. Pat. Nos. 4,262,613, 4,182,261 and 6,027,556.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The following description is provided to enable persons skilled in the art to make and use the invention and sets forth the best mode contemplated by the inventor of carrying out his invention. Various modifications, however, will be apparent to those skilled in the art, since the generic principles of the present invention have been set forth herein specifically to provide a single inkless fingerprint compound which deposited onto an ordinary paper substrate by a person's finger, palm or foot will form a permanent colorant product delineating the ridge pattern of the fingerprint area.
In accordance with the present invention an inkless fingerprint compound for forming an permanent, substantially dry, smear resistant and nonstaining perceivable colorant product representing the ridge pattern of a person's fingerprint when applied to the person's finger and deposited onto an ordinary paper substrate is prepared by mixing a color former, a developer and a chelating agent in a compatible solution such as an aqueous solution. Additional reagents may be added to the mixture as will be described. The principal reagents, i.e., the color former and developer, are maintained in equilibrium, i.e., substantially kept from reacting t
Armor Holdings Forensics Inc.
Jackson Harold L.
Klemanski Helene
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