Fingerprint detection liquid and fingerprint detection method

Abstract

To provide a fingerprint detection liquid that can be readily produced without using a large amount of solvents other than fluorinated ones, and that remains usable even after storage for a predetermined duration.SOLUTION: A fingerprint detection liquid comprises: at least one compound selected from the group consisting of ninhydrin, a ninhydrin derivative, 1,8-diazafluoren-9-one, 1,2-indanedione, and hydrindantin; and a solvent containing a hydrochlorofluoroolefin having a boiling point of 40 to 90°C.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a fingerprint detection liquid and a fingerprint detection method.

Background Art

[0002] In the field of forensic science, as methods for detecting fingerprints from a subject including fingerprints, for example, the following methods (1) to (3) can be mentioned. In recent years, methods of combining them and methods of improving accuracy using analytical instruments are also known. (1) Powder method: A method of detecting fingerprints by attaching extremely fine powders such as aluminum powder, carbon black, and fluorescent powder (2) Liquid method: A method of detecting fingerprints by causing a color reaction between ninhydrin, 1,8-diazofluoren-9-one, 1,2-indanedione, hydrindantin, silver nitrate, etc. and amino acids etc. contained in fingerprints (3) Gas method: A method of detecting fingerprints by bringing vaporized iodine, cyanoacrylate, etc. into contact with a subject Regarding the liquid method, for example, Patent Document 1 discloses a fingerprint detection liquid containing ninhydrin etc. and a specific hydrofluorocarbon.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When the present inventors examined the fingerprint detection liquid described in Patent Document 1, hydrofluorocarbon alone could not dissolve ninhydrin etc., and it was sometimes necessary to use a solvent other than hydrofluorocarbon. Examples of solvents other than hydrofluorocarbons that can dissolve ninhydrin and the like include polar solvents such as alcohol. However, since these solvents have relatively low flash points, there is a risk of ignition when using a fingerprint detection solution that uses alcohol alone as a solvent. In such cases, a method of preparing a fingerprint detection solution by dissolving ninhydrin and the like in a polar solvent and then diluting it with a fluorine solvent or the like having no flash point can be considered. However, it has been found that the preparation work becomes complicated and a fingerprint detection solution cannot be easily manufactured. It has also been found that the properties of the fingerprint detection solution may change after being stored for a predetermined time, and the solution may not be usable as a fingerprint detection solution.

[0005] An object of the present invention is to provide a fingerprint detection solution that can be easily manufactured without using a large amount of solvents other than fluorine solvents and can be used even after being stored for a predetermined time. Another object of the present invention is to provide a fingerprint detection method related to the above.

Means for Solving the Problems

[0006] As a result of intensive studies, the present inventors have found that the above problems can be solved by the following configuration. [1] At least one compound selected from the group consisting of ninhydrin, ninhydrin derivatives, 1,8-diazabicyclo[5.4.0]undec-7-ene-9-one, 1,2-indandione, and hydrindantin, A solvent containing a hydrochlorofluorolefin having a boiling point of 40 to 90°C, A fingerprint detection solution containing the above. [2] The fingerprint detection solution according to [1], wherein the solvent has no flash point. [3] The fingerprint detection solution according to [1] or [2], wherein the saturated water concentration of the hydrochlorofluorolefin at 25°C is 1000 ppm by mass or more. [4] The fingerprint detection liquid according to any one of [1] to [3], wherein the hydrochlorofluorolefin is 1-chloro-2,3,3-trifluoropropene or 1-chloro-2,3,3,4,4,5,5-heptafluoropentene. 〔5〕 A fingerprint detection method including a contact step of bringing the fingerprint detection liquid according to any one of [1] to [4] into contact with a subject.

Advantages of the Invention

[0007] According to the present invention, it is possible to provide a fingerprint detection liquid that can be easily produced without using a large amount of solvents other than fluorine solvents and can be used even after storage for a predetermined time. In addition, the present invention can also provide a fingerprint detection method related to the above.

Embodiments for Carrying Out the Invention

[0008] The meanings of the terms in the present invention are as follows. A numerical range represented by "~" means a range including the numerical values described before and after "~" as the lower limit value and the upper limit value. In the numerical ranges described step by step in this specification, the upper limit value or the lower limit value described in a certain numerical range may be replaced with the upper limit value or the lower limit value of the numerical range described in other step-by-step descriptions. Also, in the numerical ranges described in this specification, the upper limit value or the lower limit value described in a certain numerical range may be replaced with the value shown in the examples. In this specification, each component may be used alone as one kind of the substance corresponding to each component, or two or more kinds may be used in combination. Here, when two or more kinds of substances are used in combination for each component, the content of that component refers to the total content of the substances used in combination, unless otherwise specified. In this specification, a combination of two or more preferred embodiments is a more preferred embodiment.

[0009] 〔Fingerprint Detection Liquid〕 The fingerprint detection liquid contains at least one compound selected from the group consisting of ninhydrin, ninhydrin derivatives, 1,8-diazafluorene-9-one, 1,2-indanedione, and hydrindantin (hereinafter also referred to as "specific compound"), and a solvent containing hydrochlorofluorolefin (HCFO) with a boiling point of 40 to 90°C (hereinafter also referred to as "specific solvent").

[0010] With the fingerprint detection liquid of the present invention, it can be easily manufactured without using a large amount of solvents other than fluorine solvents, and it can be used even after being stored for a predetermined time. A characteristic point of the fingerprint detection liquid of the present invention is that it contains HCFO with a boiling point of 40 to 90°C as a solvent. HCFO with a boiling point of 40 to 90°C is a solvent that can sufficiently dissolve the specific compound, and the fingerprint detection liquid can be easily prepared without using a large amount of solvents other than HCFO with a boiling point of 40 to 90°C. Also, generally, the fingerprint detection liquid is often stored in an environment of about 25°C (room temperature). Even in such an environment, HCFO with a boiling point of 40 to 90°C is less likely to volatilize, and changes in the properties and composition of the fingerprint detection liquid can be suppressed. Therefore, it is presumed that the fingerprint detection liquid of the present invention can be used even after being stored for a predetermined time.

[0011] The fingerprint detection liquid preferably has no flash point. When the fingerprint detection liquid has no flash point, it is preferable from the viewpoint of reducing the possibility of ignition of the fingerprint detection liquid during fingerprint detection. As a method for making the fingerprint detection liquid have no flash point, for example, a method of adjusting the composition of the solvent contained in the specific solvent can be mentioned. It is preferable to adjust the content of HCFO with a boiling point of 40 to 90°C and the content of the solvent having no flash point, which will be described later. In other words, it is preferable to increase the content of the solvent having no flash point with respect to the total mass of the specific solvent.

[0012] <Specific compound> The fingerprint detection liquid contains a specific compound. Note that the "derivative" means a compound that is functionally and / or structurally related to the compound to be referred to. Examples of derivatives include the products or by-products of reactions that include the compound to be referred to. Examples of ninhydrin derivatives include the following compounds.

[0013] [Chemical formula]

[0014] The specific compound is preferably at least one compound selected from the group consisting of ninhydrin, 1,8-diazafluorene-9-one, 1,2-indanedione, and hydrindantin, and more preferably ninhydrin.

[0015] The content of the specific compound is preferably 5000 mass ppm or less, more preferably 1000 mass ppm or less, still more preferably 500 mass ppm or less, and particularly preferably 300 mass ppm or less, based on the total mass of the fingerprint detection solution. The lower limit is preferably more than 0 mass ppm, and more preferably 10 mass ppm or more.

[0016] <Specific solvent> The fingerprint detection solution contains a specific solvent. The specific solvent contains an HCFO having a boiling point of 40 to 90°C. As the HCFO having a boiling point of 40 to 90°C, only one type of compound may be used, or two or more types of compounds may be used.

[0017] The boiling point of the above HCFO is 40 to 90°C, preferably 40 to 70°C, and more preferably 40 to 60°C. In this specification, the boiling point means the standard boiling point unless otherwise specified. For example, catalog values may be used for the boiling point values.

[0018] From the perspective of improving the solubility of a specific compound, the saturated water concentration of HCFO with a boiling point of 40 to 90°C at 25°C is preferably 500 mass ppm or more, more preferably 1000 mass ppm or more. The upper limit is 1500 mass ppm or less. The value of the saturated water concentration may be, for example, a value measured by a known measurement method such as the Karl Fischer moisture measurement method or a catalog value.

[0019] The above HCFO is composed of hydrogen atoms, carbon atoms, fluorine atoms and chlorine atoms and has a carbon-carbon double bond. The number of carbon atoms of the above HCFO is preferably 1 to 10, more preferably 3 to 5. The number of fluorine atoms of the above HCFO is preferably 1 to 10, more preferably 3 to 6. The number of chlorine atoms of the above HCFO is preferably 1 to 10, more preferably 1 or 2. The number of carbon-carbon double bonds of the above HCFO is preferably 1 to 3, more preferably 1.

[0020] Examples of HCFO with a boiling point of 40 to 90°C include 1-chloro-2,3,3-trifluoropropene (HCFO-1233yd, boiling point 54°C, saturated water concentration (25°C) 1500 mass ppm), 1-chloro-2,3,3,4,4,5,5-heptafluoropentene (HCFO-1437dycc, boiling point 89°C, saturated water concentration (25°C) 1400 mass ppm), and HCFO-1233yd is preferred. In this specification, when a compound has geometric isomers, either the E form or the Z form may be used. Also, in this specification, for a compound having geometric isomers, unless otherwise specified, when using the compound name or its abbreviation, it indicates at least one selected from the group consisting of the Z form and the E form, and when (E) or (Z) is attached after the compound name or the abbreviation of the compound, it represents the (E) form or the (Z) form of the compound. Specifically, the notation of HCFO-1233zd(E) indicates the E form of HCFO-1233zd.

[0021] If the specific solvent contains an HCFO with a boiling point of 40 to 90°C, it may also contain other solvents other than the HCFO with a boiling point of 40 to 90°C from the viewpoints of further improving the solubility of the specific compound and cost reduction. Also, from the viewpoint of handleability, the boiling point of the other solvent is preferably 25°C or higher. Examples of the other solvents include HCFOs other than those with a boiling point of 40 to 90°C, fluorocarbons such as hydrofluorocarbons (HFCs) and hydrofluoroethers (HFEs), alcohol solvents, and ketone solvents. Examples of HCFOs other than those with a boiling point of 40 to 90°C include 1-chloro-3,3,3-trifluoropropene (HCFO-1233zd(E), boiling point 19°C, HCFO-1233zd(Z), boiling point 39°C). Examples of HFCs include 1,1,1,3,3-pentafluorobutane (HFC-365mfc), and 1,1,1,2,3,4,4,5,5,5-decafluoropentane (HFC-43-10mee, boiling point 55°C). Examples of HFEs include 1,1,2-trifluoroethyl-2,2,2-trifluoroethyl ether (HFE-347pc-f, boiling point 56°C), methyl nonafluorobutyl ether (HFE-449s, HFE449mmyc, boiling point 61°C), ethyl nonafluorobutyl ether (HFE-569sf, HFE-569mmyc, boiling point 76°C), Examples of HFOs include methoxy perfluoroheptene (MPHE, boiling point 110°C). Examples of alcohol solvents include methyl alcohol, ethyl alcohol, and propanol. Examples of ketone solvents include dimethyl ketone, methyl ethyl ketone, and methyl isobutyl ketone. When the specific solvent contains two or more components, it is preferable that these components form an azeotropic or azeotrope-like composition. If the specific solvent is an azeotropic or azeotrope-like composition, the change in the composition of the specific solvent due to volatilization can be more suppressed, and it is easier to volatilize the specific solvent at a desired temperature during the heat treatment (for example, the drying process described later) for promoting the color reaction between the specific compound and the components contained in the fingerprint.

[0022] The specific solvent preferably has no flash point. When the specific solvent has no flash point, it is preferable from the viewpoint of reducing the possibility of ignition of the fingerprint detection liquid containing the specific solvent during fingerprint detection. As a method for preparing in the above aspect, for example, a method of adjusting the composition of the solvent contained in the specific solvent can be mentioned, and it is preferable to adjust the content of the solvent having no flash point. In other words, it is preferable to increase the content of the solvent having no flash point with respect to the total mass of the specific solvent. Examples of the solvent having no flash point include fluorocarbons such as HCFO, HFC, and HFE whose boiling points are other than 40 to 90°C. For the measurement of the flash point, for example, a known measurement method such as a method using a flash point measuring device such as the tag closed type shown in ASTM D56 and the Cleveland open type shown in ASTM D92 may be referred to, or a catalog may be referred to.

[0023] The specific solvent is preferably 80% by mass or more, more preferably 90% by mass or more, and still more preferably 99% by mass or more with respect to the total mass of the fingerprint detection liquid. The upper limit is less than 100% by mass. The content of HCFO having a boiling point of 40 to 90°C is preferably 80% by mass or more, more preferably 90% by mass or more, and still more preferably 99% by mass or more with respect to the total mass of the specific solvent. The upper limit is 100% by mass. If it is within the above range (especially 90% by mass or more), it is easy to prepare a fingerprint detection liquid or a specific solvent having no flash point, and the safety is higher.

[0024] <Other components> The fingerprint detection liquid may contain other components other than the above various components. Examples of other components include stabilizers and propellants. Examples of the stabilizer include the compounds described in International Publication No. 2017 / 122801. The propellant is used when the fingerprint detection liquid is used in the form of an aerosol. Examples of the propellant include liquefied gas and compressed gas. Examples of the liquefied gas include dimethyl ether (DME), liquefied petroleum gas (LPG), propane, butane, isobutane, 1,1-difluoroethane (HFC-152a), 1,1,1,2-tetrafluoroethane (HFC-134a), 2,3,3,3-tetrafluoropropene (HFO-1234yf), and 1,3,3,3-tetrafluoropropene (HFO-1234ze). Examples of the compressed gas include nitrogen, carbon dioxide, and nitrous oxide.

[0025] 〔Method for producing fingerprint detection liquid〕 The method for producing the fingerprint detection liquid may be a known production method. Specifically, a method for producing a fingerprint detection liquid including a step of dissolving a specific compound in a specific solvent is preferable. During the preparation of the specific solvent and the dissolution of the specific compound, stirring or shaking may be performed.

[0026] 〔Fingerprint detection method〕 The fingerprint detection method may be any method using the above-mentioned fingerprint detection liquid. Specifically, a fingerprint detection method including a contact step of bringing the fingerprint detection liquid into contact with a subject is preferable. The fingerprint detection liquid is the above-mentioned fingerprint detection liquid. Examples of the subject include ordinary paper, thermal paper, and wood.

[0027] Examples of the method of bringing the fingerprint detection liquid into contact with the subject include a method of immersing the subject in the fingerprint detection liquid, a method of applying the fingerprint detection liquid to the subject with a brush, and a method of spraying the fingerprint detection liquid onto the subject with a spray or the like. The immersion time is preferably 5 seconds to 1 minute. The immersion temperature is preferably 10 to 30°C.

[0028] The fingerprint detection method preferably includes a drying step of drying the subject obtained in the contact step. Drying may or may not involve heating. When heating, from the perspective of shortening the reaction time between the specific compound and the components contained in the fingerprint, and since the solvent of the fingerprint detection liquid evaporates and takes heat (latent heat of vaporization) from the subject, as a result, the temperature of the subject becomes lower than the surrounding environment, and there is a possibility that moisture in the air condenses and adheres to the surface of the subject, 40 to 60°C is preferred. When such adhesion of moisture to the subject occurs, the developed fingerprint may become unclear. When the fingerprint detection liquid of the present invention is at 40°C or higher, such adhesion of moisture to the subject can be prevented.

[0029] The fingerprint detection method may repeat each step. By repeating each step, the color development of the fingerprint is more promoted and the clarity of the color development is improved. The number of repetitions is preferably 3 or more, and more preferably 5 or more. In addition, when repeating each step in the fingerprint detection method, for example, each contact step and each drying step may be performed under the same or different conditions, or only one of the contact step or the drying step may be repeated. Among them, when the fingerprint detection method repeats each step, it is preferable that the fingerprint detection method repeats in the order of the contact step, the drying step, the contact step, and the drying step.

Examples

[0030] Hereinafter, the present invention will be described in detail with examples. Example 1 and Example 2 are examples, and Example 3 and Example 4 are comparative examples. However, the present invention is not limited to these examples.

[0031] 〔Example 1〕 Ninhydrin was dissolved in a 100% by mass liquid of HCFO-1233yd (AMOLEA AS-300 manufactured by AGC, boiling point 54°C, saturated moisture concentration (25°C) 1500 mass ppm) at 25°C to a concentration of 100 mass ppm to prepare Fingerprint Detection Liquid 1. Fingerprint Detection Liquid 1 was immersed and applied to heat-sensitive paper with fingerprints for 5 seconds, and then left to dry in a constant temperature bath at 50°C for 15 minutes, and fingerprints could be detected. Even after the fingerprint detection liquid 1 was left standing and stored at 25°C for 30 minutes, there were almost no changes in the properties and appearance of the fingerprint detection liquid 1. When fingerprint detection was attempted using the same procedure as above, fingerprints could be detected without any problems in the same way.

[0032] 〔Example 2〕 A fingerprint detection liquid 2 was prepared in the same procedure as in Example 1, except that 1-chloro-2,3,3,4,4,5,5-heptafluoropentene (HCFO-1437dycc, boiling point 89°C, saturated water concentration (25°C) 1400 mass ppm) was used instead of HCFO-1233yd. Even after the fingerprint detection liquid 2 was left standing and stored at 25°C for 30 minutes, there were almost no changes in the properties and appearance of the fingerprint detection liquid 2. When fingerprint detection was attempted using the same procedure as above, fingerprints could be detected without any problems in the same way.

[0033] 〔Example 3〕 When ninhydrin was mixed at 25°C into the E-isomer of 1-chloro-3,3,3-trifluoropropene (HCFO-1233zd(E), boiling point 19°C) to obtain a mixture at 100 mass ppm, ninhydrin did not dissolve. Further, when ethanol was added to the mixture to be 5 mass% based on the total mass of the mixture, ninhydrin dissolved and a fingerprint detection liquid C1 was obtained. The fingerprint detection liquid C1 was immersed and applied to the same thermal paper with fingerprints attached for 5 seconds, and then left standing and dried in a constant temperature bath at 50°C for 15 minutes. As a result, fingerprints could be detected. Also, when the fingerprint detection liquid C1 was left standing and stored at 25°C for 30 minutes, 90 mass% or more of the added amount of HCFO-1233zd(E) in the fingerprint detection liquid C1 volatilized, and as a result, the fluidity of the fingerprint detection liquid C1 was lost, so it could not be used as a fingerprint detection liquid.

[0034] 〔Example 4〕 When ninhydrin was added at 25°C to 1,1,1,2,2,3,4,5,5,5-decafluoropentane (HFC-43-10mee, boiling point 55°C) to prepare a fingerprint detection liquid C2 at 100 mass ppm, ninhydrin did not dissolve.

[0035] From the above results, it was shown that according to the present invention, it is possible to provide a fingerprint detection liquid that can be easily produced without using a solvent other than a fluorine solvent and can be used even after storage for a predetermined time (Examples 1 and 2).

Claims

1. at least one compound selected from the group consisting of ninhydrin, a ninhydrin derivative, 1,8-diazafluorene-9-one, 1,2-indandione, and hydrindantin, a solvent containing a hydrochlorofluorolefin having a boiling point of 40 to 90°C, A fingerprint detection liquid containing the same.

2. The fingerprint detection liquid according to claim 1, wherein the solvent has no flash point.

3. The fingerprint detection liquid according to claim 1 or 2, wherein the saturated water concentration of the hydrochlorofluorolefin at 25°C is 1000 ppm by mass or more.

4. The fingerprint detection liquid according to claim 1 or 2, wherein the hydrochlorofluorolefin is 1-chloro-2,3,3-trifluoropropene or 1-chloro-2,3,3,4,4,5,5-heptafluoropentene.

5. A fingerprint detection method comprising a contact step of bringing the fingerprint detection liquid according to claim 1 or 2 into contact with a subject.

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