JP2016150951A - Artificial fingerprint liquid, and fingerprint resistance evaluation method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an artificial fingerprint liquid that makes it possible to prepare fingerprint marks comparable to human fingerprint marks and is suitable as a fingerprint resistance evaluation reagent.SOLUTION: An artificial fingerprint liquid has an oil content, water, and a surfactant of 5 mass%-46 mass% relative to the oil content. The artificial fingerprint liquid is a water-in-oil emulsion.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an artificial fingerprint liquid used for evaluation of fingerprint adhesion or fingerprint removability, and a fingerprint resistance evaluation method using the artificial fingerprint liquid.

  In a device such as a portable terminal or a laptop computer in which glass is used for the display or the case surface, contamination by various contaminants and adhesion of fingerprints occur. These are not preferred. Therefore, surface treatment is usually applied to the glass surface in order to improve antifouling properties, reduce fingerprint adhesion, and improve fingerprint removability.

As a method for evaluating whether or not fingerprint contamination has been improved by the surface treatment, a method is often used in which a genuine fingerprint is pressed against the glass surface and the adhesion and wiping property of the fingerprint trace is visually evaluated.
However, such an evaluation method using a real fingerprint strongly depends on the individual and the environment, and thus lacks quantitative and reproducibility.
From such a situation, it is desired to develop an artificial fingerprint liquid for quantitatively evaluating the quality of the glass surface with good reproducibility.

  Regarding the artificial fingerprint liquid, an artificial fingerprint liquid for evaluating the antifouling property to an optical recording medium has been proposed (for example, see Patent Document 1).

JP 2004-35824 A

  However, in the artificial fingerprint liquid described in Patent Document 1, the fingerprint trace formed is clearly different from the human fingerprint trace. Therefore, in the evaluation of fingerprint resistance such as fingerprint adhesion and fingerprint removability, there is a problem that the result of the fingerprint trace using the artificial fingerprint liquid does not necessarily match the result of the human fingerprint trace.

  An object of the present invention is to solve the conventional problems and achieve the following objects. That is, the present case provides an artificial fingerprint liquid suitable as a fingerprint resistance evaluation reagent, and a fingerprint resistance evaluation method excellent in quantitative and reproducibility, which can produce fingerprint marks equivalent to human fingerprint marks. For the purpose.

  The disclosed artificial fingerprint liquid contains an oil component, water, and a surfactant in an amount of 5 to 46% by mass based on the oil component, and is a water-in-oil emulsion.

The disclosed fingerprint resistance evaluation method is:
Applying the disclosed artificial fingerprint liquid on a substrate and forming a liquid film of the artificial fingerprint liquid on the substrate;
Pressing the rubber having a transfer surface imitating a fingerprint on the liquid film, and transferring the artificial fingerprint liquid to the transfer surface;
Pressing the transfer surface to which the artificial fingerprint liquid is attached to the surface of the evaluation substrate to form an artificial fingerprint mark on the evaluation substrate; and
Wiping off the artificial fingerprint mark;
including.

According to the disclosed artificial fingerprint liquid, the above-mentioned problems can be solved and the object can be achieved, and a fingerprint trace equivalent to a human fingerprint trace can be produced, and an artificial fingerprint suitable as an evaluation reagent for fingerprint resistance Liquid can be provided.
According to the disclosed fingerprint resistance evaluation method, the conventional problems can be solved, the object can be achieved, and a fingerprint resistance evaluation method excellent in quantitativeness and reproducibility can be provided.

FIG. 1 is a schematic view of a transfer surface having multiple concentric irregularities. FIG. 2 is a flowchart of an example of a fingerprint resistance evaluation method. FIG. 3 is a photograph of an artificial fingerprint mark in the example.

(Artificial fingerprint solution)
The disclosed artificial fingerprint liquid contains at least an oil, water, and a surfactant, preferably contains a powder, and further contains other components as necessary.

  The artificial fingerprint liquid is a water-in-oil emulsion. The water-in-oil emulsion is an emulsion in which an oil phase is a continuous phase and water droplets are dispersed therein.

<Oil content>
The oil is not particularly limited and may be appropriately selected depending on the intended purpose, but is any one of higher fatty acids and derivatives thereof, and terpenes, in terms of being close to the components of fingerprint marks formed by human fingerprints. It is preferable that

As carbon number of the said higher fatty acid, 10-25 are preferable and 15-20 are more preferable.
Examples of the higher fatty acid derivatives include higher fatty acid esters. As carbon number of the fatty acid site | part in the derivative | guide_body of the said higher fatty acid, 10-25 are preferable and 15-20 are more preferable.

Examples of the higher fatty acid include lauric acid, myristic acid, palmitic acid, stearic acid, arachidonic acid, behenic acid, isostearic acid, oleic acid, 2-palmitoleic acid, petrothelic acid, elaidic acid, ricinoleic acid, linoleic acid, and linoleic acid. Examples include elaidic acid and linolenic acid.
Examples of the higher fatty acid ester include higher fatty acid diglycerides and higher fatty acid triglycerides. As the triglyceride, triolein is preferable because it is close to a component of a fingerprint mark formed by a human fingerprint.
These may be used individually by 1 type and may use 2 or more types together.

The terpenes are a general term for compounds having an isoprene unit represented by a molecular formula of C ₅ H ₈ as a structural unit, and are also referred to as terpenoids. The terpenes are usually natural products. The terpenes are extracted from, for example, plant lipids and animal lipids.

Examples of the terpenes include, for example, squalene, limonene, α-pinene, β-pinene, camphene, terpineol, kazinene, karen, γ-terpinene, d-limonene, dipinten, terpinolene, β-felandene, pipaneene, camphore, Examples include myrcene. Among these, squalene is preferable because it is close to the component of fingerprint traces formed by human fingerprints.
These may be used individually by 1 type and may use 2 or more types together.

  The content of the oil in the artificial fingerprint liquid is not particularly limited as long as a water-in-oil emulsion can be formed, and can be appropriately selected according to the purpose.

<Water>
There is no restriction | limiting in particular as said water, According to the objective, it can select suitably, For example, deionized water, clean water, a pure water etc. are mentioned.

  The content of the water in the artificial fingerprint liquid is not particularly limited as long as a water-in-oil emulsion can be formed, and can be appropriately selected according to the purpose.

<Surfactant>
The surfactant is not particularly limited as long as the liquid containing the oil and water can be made into an emulsion, and can be appropriately selected according to the purpose. The surfactant is also called an emulsifier.

  Examples of the surfactant include an anionic surfactant, a cationic surfactant, and a nonionic surfactant.

  Examples of the anionic surfactant include a surfactant having a carboxylic acid, sulfonic acid, or phosphoric acid structure as a hydrophilic group. Examples of such surfactants include linear sodium alkylbenzene sulfonate, sodium laurate, and sodium dodecyl sulfate. Among these, linear sodium alkylbenzene sulfonate is preferable because it is close to the component of the fingerprint trace formed by human fingerprints. In addition, since surfactant is contained in hair care products, body care products, etc., it is detected from fingerprint marks formed by human fingerprints.

  Examples of the cationic surfactant include quaternary ammonium salts. Examples of the quaternary ammonium salt include alkyl trimethyl ammonium salt, dialkyl dimethyl ammonium salt, alkyl benzyl dimethyl ammonium salt and the like.

Examples of the nonionic surfactant include polyoxyethylene alkyl ether, polyoxyethylene alkyl allyl ether, polyoxyethylene glycol, polyoxypropylene glycol, polyoxyethylene / polyoxypropylene block copolymer, sorbitan fatty acid ester, polyoxyethylene And ethylene sorbitan fatty acid esters.
Examples of the polyoxyethylene alkyl ether include polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether, polyoxyethylene oleyl ether, and the like.
Examples of the polyoxyethylene alkyl allyl ether include polyoxyethylene octylphenol ether and polyoxyethylene nonylphenol ether.
Examples of the sorbitan fatty acid ester include sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan monooleate, sorbitan trioleate, sorbitan tristearate and the like.
Examples of the polyoxyethylene sorbitan fatty acid ester include polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan trioleate, polyoxyethylene sorbitan tristearate. Etc.

  These surfactants may be used alone or in combination of two or more.

  Content of the said surfactant in the said artificial fingerprint liquid is 5 mass%-46 mass% with respect to the said oil component. When the content is less than 5% by mass, the amount of water droplets in the artificial fingerprint liquid is small, and a fingerprint trace equivalent to a human fingerprint trace cannot be produced. When the content exceeds 46% by mass, a water-in-oil emulsion cannot be produced, and as a result, a fingerprint trace equivalent to a human fingerprint trace cannot be produced.

<Other ingredients>
There is no restriction | limiting in particular as said other component, Although it can select suitably according to the objective, Powder is preferable. Note that the powder may or may not be present.

<< Powder >>
Fingerprint marks formed by human fingerprints contain solid components in addition to liquid and solid oils. Therefore, it is preferable that the artificial fingerprint liquid contains a powder because it is close to a component of a fingerprint mark formed by a human fingerprint.
Moreover, the artificial fingerprint liquid contains the powder, so that it is easy to adjust the viscosity and the adhesiveness to the evaluation substrate.
Note that most of the solid components in fingerprint traces formed by human fingerprints are proteins called keratin. However, in the artificial fingerprint liquid, powders other than keratin can substitute for keratin.

Examples of the powder include Kanto Loam (JIS test powder 1), silica fine particles, titanium oxide fine particles, alumina fine particles, iron oxide fine particles, keratin fine particles, chitin fine particles, chitosan fine particles, acrylic fine particles, styrene fine particles, Examples thereof include divinylbenzene fine particles, polyamide fine particles, polyimide fine particles, polyurethane fine particles, melamine fine particles, and zeolite.
These may be used individually by 1 type and may use 2 or more types together.

There is no restriction | limiting in particular as an average particle diameter of the said powder, Although it can select suitably according to the objective, 100 micrometers or less are preferable and 50 micrometers or less are more preferable. The average particle size of the powder is preferably 0.05 μm or more, more preferably 0.5 μm or more. The average particle diameter can be measured using, for example, a laser diffraction particle size distribution measuring apparatus.
Examples of such powder include JIS Z8901 test powders 1 and 2, ISO test powder 12103-1, Japan Powder Industrial Technology Association (APPIE) standard powder, and the like. Such a test powder is preferable as the powder because it has a uniform particle size, a stable particle size distribution, and is available at a relatively low cost. Among the JIS Z8901 test powders 1, Kanto Loam is preferable.

  There is no restriction | limiting in particular as content of the said powder in the said artificial fingerprint liquid, Although it can select suitably according to the objective, 50 mass%-400 by the point which can be made moderate viscosity with respect to the said oil component. % By mass is preferable, 100% by mass to 300% by mass is more preferable, and 150% by mass to 250% by mass is particularly preferable.

  The artificial fingerprint liquid is a water-in-oil emulsion, and the fluidity of the liquid is reduced. Therefore, when the artificial fingerprint liquid is attached on the evaluation substrate, aggregation is unlikely to occur and the fixability is good. . Therefore, the fingerprint trace by the artificial fingerprint liquid is equivalent to the human fingerprint trace. As a result, by using the artificial fingerprint liquid, the fingerprint resistance can be evaluated quantitatively with good reproducibility.

(Fingerprint resistance evaluation method)
The disclosed fingerprint resistance evaluation method includes at least a liquid film formation step, a transfer step, an artificial fingerprint trace formation step, and a wiping step, and further includes other steps as necessary.

<Liquid film formation process>
The liquid film forming step is not particularly limited as long as it is a step of applying the disclosed artificial fingerprint liquid on a base material and forming a liquid film of the artificial fingerprint liquid on the base material. Can be selected as appropriate.

  There is no restriction | limiting in particular as said base material, According to the objective, it can select suitably, A plastic base material, a glass base material, a metal base material etc. are mentioned. Among these, a glass substrate is preferable in that the difference between the wiping property of the artificial fingerprint liquid and the wiping property of human fingerprints is less likely to occur.

  There is no restriction | limiting in particular as a method of apply | coating the said artificial fingerprint liquid on the said base material, According to the objective, it can select suitably, For example, dripping, immersion, spray application etc. are mentioned.

  There is no restriction | limiting in particular as thickness of the said liquid film, According to the objective, it can select suitably.

<Transfer process>
The transfer step is not particularly limited as long as it is a step of pressing the rubber having a transfer surface imitating a fingerprint against the liquid film and transferring the artificial fingerprint liquid to the transfer surface, depending on the purpose. It can be selected appropriately. Since the rubber has elasticity similar to that of a human finger, the rubber is suitable as a member for producing the artificial fingerprint mark in the fingerprint resistance evaluation method.

  There is no restriction | limiting in particular as said rubber | gum, According to the objective, it can select suitably, For example, silicone rubber, a butadiene rubber, etc. are mentioned.

The transfer surface has a shape imitating a fingerprint. The shape of the transfer surface is not particularly limited as long as it is a shape imitating a fingerprint, and can be appropriately selected according to the purpose. This is preferable in terms of higher quantitativeness and reproducibility.
Examples of the multiple concentric concavities and convexities include a shape as shown in FIG.

  Further, as the rubber, a rubber stopper for printing an artificial fingerprint liquid defined in JIS K2246-2007 may be used. That is, no. A small round surface (diameter of about 26 mm) of the rubber plug 10 may be used by roughening by rubbing with an abrasive material of AA240 defined in JIS R6251 or JIS R6252 or an abrasive material having equivalent performance.

  In order to obtain dimensions close to actual fingerprints, it is preferable to use rubber having a transfer surface diameter of 8 mm to 25 mm, and more preferably rubber having a transfer surface diameter of 8 mm to 20 mm.

  There is no restriction | limiting in particular as a pressure at the time of pressing the said rubber | gum on the said liquid film, According to the objective, it can select suitably, For example, 1.0N-2.0N etc. are mentioned.

<Artificial fingerprint trace formation process>
The artificial fingerprint trace forming step is not particularly limited as long as it is a step of pressing the transfer surface on which the artificial fingerprint liquid is adhered to the surface of the evaluation base material to form an artificial fingerprint trace on the evaluation base material. And can be appropriately selected according to the purpose.

There is no restriction | limiting in particular as said evaluation base material, According to the objective, it can select suitably, For example, a plastic base material, a glass base material, a metal base material etc. are mentioned. The artificial fingerprint liquid has particularly good fixability to glass, but other substrates can be used as an evaluation substrate.
The surface of the evaluation base material may be surface-treated. Examples of the surface treatment include antifouling treatment and antifogging treatment.

  There is no restriction | limiting in particular as a pressure at the time of pressing the said transfer surface against the surface of the said evaluation base material, According to the objective, it can select suitably, For example, 1.0N-2.0N etc. are mentioned.

<Wipe process>
The wiping step is not particularly limited as long as it is a step of wiping the artificial fingerprint trace, and can be appropriately selected according to the purpose.

  The wiping can be performed using, for example, a cloth, paper, or the like as a wiping material for wiping the artificial fingerprint trace. Examples of the cloth include woven cloth and non-woven cloth. Examples of the paper include Kimwipe (manufactured by Nippon Paper Crecia).

  In the wiping step, wiping is preferably performed according to a predetermined wiping method. As a predetermined wiping method, for example, a method of wiping by moving the wiping material in a certain direction while pressing the wiping material against the artificial fingerprint trace on the evaluation substrate may be mentioned.

  In the wiping step, for example, the fingerprint resistance of the evaluation substrate can be evaluated by counting the number of times of wiping when the artificial fingerprint mark is wiped.

  When performing the fingerprint resistance evaluation method, a plurality of human fingerprints are wiped in advance, and the number of wipes obtained as a statistically significant result is obtained, and compared with the number of wipes in the wiping step. May be. By doing so, it is also possible to confirm the correlation with the wiping property of human fingerprint marks.

By performing the fingerprint resistance evaluation method, the fingerprint resistance of the evaluation substrate can be evaluated.
The fingerprint resistance evaluation method can be suitably used for the fingerprint resistance evaluation of the antifouling surface treatment in the research and development of the antifouling surface treatment of a substrate such as glass.

Here, an example of the fingerprint resistance evaluation method will be described with reference to a flowchart.
FIG. 2 is a flowchart of an example of a fingerprint resistance evaluation method.
First, a liquid film forming process is performed. In this step, the disclosed artificial fingerprint liquid is applied on a base material to form a liquid film of the artificial fingerprint liquid on the base material.
Subsequently, a transfer process is performed. In this step, rubber having a transfer surface imitating a fingerprint is pressed against the liquid film to transfer the artificial fingerprint liquid onto the transfer surface.
Subsequently, an artificial fingerprint mark forming step is performed. In this step, the transfer surface on which the artificial fingerprint liquid is attached is pressed against the surface of the evaluation base material to form an artificial fingerprint mark on the evaluation base material.
Subsequently, a wiping process is performed. In this step, the artificial fingerprint trace is wiped off. At this time, the number of times of wiping is counted. And the evaluation result of the fingerprint resistance of the said evaluation base material is derived | led-out by the frequency | count of the wiping.

  Examples of the disclosed technology will be described below, but the disclosed technology is not limited to the following examples.

Example 1
<Preparation of artificial fingerprint liquid>
Triolein (manufactured by Wako Pure Chemical Industries, Ltd.), 65% by weight sodium dodecylbenzenesulfonate (DBS) aqueous solution (manufactured by Kao Corporation), and 11 types of Kanto Loam (JIS Z 8901, manufactured by Japan Powder Industrial Technology Association) , Triolein: 65% by weight sodium dodecylbenzenesulfonate aqueous solution: 11 types of Kanto loam = 1.0: 0.08: 2.0 (mass ratio) to obtain an artificial fingerprint liquid which is a water-in-oil emulsion It was.

(Example 2)
<Preparation of artificial fingerprint liquid>
Triolein (manufactured by Wako Pure Chemical Industries, Ltd.), 65% by weight sodium dodecylbenzenesulfonate aqueous solution (manufactured by Kao Corporation), and 11 types of Kanto Loam (JIS Z 8901, manufactured by Japan Powder Industry Technical Association) : 65 mass% sodium dodecylbenzenesulfonate aqueous solution: 11 types of Kanto Loam = 1.0: 0.3: 2.0 (mass ratio) to obtain an artificial fingerprint liquid which is a water-in-oil emulsion.

(Example 3)
<Preparation of artificial fingerprint liquid>
Triolein (manufactured by Wako Pure Chemical Industries, Ltd.), 65% by weight sodium dodecylbenzenesulfonate aqueous solution (manufactured by Kao Corporation), and 11 types of Kanto Loam (JIS Z 8901, manufactured by Japan Powder Industry Technical Association) : 65 mass% sodium dodecylbenzenesulfonate aqueous solution: 11 types of Kanto Loam = 1.0: 0.7: 2.0 (mass ratio) to obtain an artificial fingerprint liquid which is a water-in-oil emulsion.

Example 4
<Preparation of artificial fingerprint liquid>
Squalene (manufactured by Wako Pure Chemical Industries, Ltd.), 65% by mass sodium dodecylbenzenesulfonate aqueous solution (manufactured by Kao Corporation), and 11 types of Kanto Loam (JIS Z 8901, manufactured by Japan Powder Industrial Technology Association) Mass% sodium dodecylbenzenesulfonate aqueous solution: 11 types of Kanto loam = 1.0: 0.7: 2.0 (mass ratio) were mixed to obtain an artificial fingerprint liquid which is a water-in-oil emulsion.

(Comparative Example 1)
<Preparation of artificial fingerprint liquid>
Triolein (manufactured by Wako Pure Chemical Industries, Ltd.) and 11 types of Kanto Loam (JIS Z 8901, manufactured by Japan Powder Industrial Technology Association), triolein: 11 types of Kanto Loam = 1.0: 2.0 (mass ratio) ) To obtain an artificial fingerprint liquid.

(Comparative Example 2)
<Preparation of artificial fingerprint liquid>
Triolein (manufactured by Wako Pure Chemical Industries, Ltd.), 65% by weight sodium dodecylbenzenesulfonate aqueous solution (manufactured by Kao Corporation), and 11 types of Kanto Loam (JIS Z 8901, manufactured by Japan Powder Industry Technical Association) : 65 mass% sodium dodecylbenzenesulfonate aqueous solution: 11 types of Kanto Loam = 1.0: 0.05: 2.0 (mass ratio) to obtain an artificial fingerprint liquid which is a water-in-oil emulsion.

(Comparative Example 3)
<Preparation of artificial fingerprint liquid>
Triolein (manufactured by Wako Pure Chemical Industries, Ltd.), 65% by weight sodium dodecylbenzenesulfonate aqueous solution (manufactured by Kao Corporation), and 11 types of Kanto Loam (JIS Z 8901, manufactured by Japan Powder Industry Technical Association) : 65% by mass sodium dodecylbenzenesulfonate aqueous solution: 11 types of Kanto Loam = 1.0: 1.0: 2.0 (mass ratio) to obtain an artificial fingerprint solution.

[Production of artificial fingerprint marks]
Each artificial fingerprint liquid produced above was uniformly applied on a glass substrate to obtain a liquid film. Subsequently, a transfer material made of silicone rubber (manufactured by Shin-Etsu Chemical Co., Ltd.) having a circular transfer surface with a diameter of 1.5 cm having multiple concentric concavities and convexities as shown in FIG. The liquid film was pressed with a force of 1.5 N to transfer the liquid film to the transfer surface. Subsequently, the transfer surface of the transfer material was pressed onto another glass substrate with a force of 1.5 N to produce an artificial fingerprint mark. In addition, the antifouling surface treatment is not performed on the glass substrate on which the artificial fingerprint mark is formed.

<Adhesiveness of artificial fingerprint marks>
About the artificial fingerprint trace produced on the glass substrate, it was visually evaluated whether (1) the glass was not repelling the artificial fingerprint trace and (2) the multiple concentric traces of the transfer material were clear. . Evaluation was made according to the following evaluation criteria. The results are shown in Table 1. FIG. 3 shows a photograph.
〔Evaluation criteria〕
○: Glass does not play artificial fingerprint traces, and multiple concentric traces of the transfer material are clear.
X: Corresponds to at least one of glass repelling artificial fingerprint traces and unclear multi-concentric traces of transfer material.

<Removability of artificial fingerprint marks>
The operation of wiping 50 mm from the front to the back while applying a load of 250 g / cm ² to a Kimwipe that is folded in five with respect to the artificial fingerprint trace produced on the glass substrate is defined as one operation. Repeated until fingerprint mark was wiped off. The number of times of wiping required at this time was compared with 9 times that is the number of times of wiping human fingerprints, and evaluation was performed according to the following evaluation criteria. The results are shown in Table 1.
〔Evaluation criteria〕
○: Number of times of wiping 7 to 10 times △: Number of times of wiping 4 to 6 times ×: Number of times of wiping 1 to 3 times 9 times as the number of times human fingerprints are wiped Determined the number of wipes obtained as a statistically significant result after wiping off multiple human fingerprints.

The unit of the blending amount in Table 1 is part by mass unless otherwise specified.
-Amount of surfactant (DBS) of Comparative Example 2 (oil content: mass%)
= 100 (%) x 0.05 x 0.65 / 1.0 = 3
-Amount of surfactant (DBS) of Example 1 (oil content: mass%)
= 100 (%) x 0.08 x 0.65 / 1.0 = 5
-Amount of surfactant (DBS) of Example 2 (oil content: mass%)
= 100 (%) x 0.3 x 0.65 / 1.0 = 20
-Amount of surfactant (DBS) of Example 3 (oil content: mass%)
= 100 (%) x 0.7 x 0.65 / 1.0 = 46
-Amount of surfactant (DBS) of Example 4 (oil content: mass%)
= 100 (%) x 0.7 x 0.65 / 1.0 = 46
-Amount of surfactant (DBS) of Comparative Example 3 (oil content: mass%)
= 100 (%) x 1.0 x 0.65 / 1.0 = 65

In Examples 1 to 4, the formed artificial fingerprint trace was equivalent to a human fingerprint trace.
On the other hand, in Comparative Examples 1 to 3, the formed artificial fingerprint traces partially or entirely aggregated to form droplets, which were different from human fingerprint traces.

In Examples 1 to 4, the number of wiping operations was equivalent to the reference wiping number.
On the other hand, in Comparative Examples 1 to 3, the number of wiping was different from the reference number of wiping.

Regarding the above embodiment, the following additional notes are disclosed.
(Additional remark 1) The artificial fingerprint liquid characterized by being a water-in-oil emulsion containing oil content, water, and 5 mass%-46 mass% surfactant with respect to the said oil content.
(Additional remark 2) The artificial fingerprint liquid of Additional remark 1 whose said oil component is either a higher fatty acid, its derivative (s), and terpenes.
(Supplementary note 3) The artificial fingerprint liquid according to any one of supplementary notes 1 and 2, wherein the oil component is either triolein or squalene.
(Appendix 4) The artificial fingerprint liquid according to any one of appendices 1 to 3, wherein the surfactant is sodium linear alkylbenzene sulfonate.
(Supplementary note 5) The artificial fingerprint liquid according to any one of supplementary notes 1 to 4, further comprising a powder.
(Additional remark 6) The artificial fingerprint liquid of Additional remark 5 whose said powder is Kanto loam (powder 1 for JIS test).
(Appendix 7) A step of applying the artificial fingerprint liquid according to any one of appendices 1 to 6 on a base material, and forming a liquid film of the artificial fingerprint liquid on the base material;
Pressing the rubber having a transfer surface imitating a fingerprint on the liquid film, and transferring the artificial fingerprint liquid to the transfer surface;
Pressing the transfer surface to which the artificial fingerprint liquid is attached to the surface of the evaluation substrate to form an artificial fingerprint mark on the evaluation substrate; and
Wiping off the artificial fingerprint mark;
A method for evaluating fingerprint resistance, comprising:
(Supplementary note 8) The method for evaluating fingerprint resistance according to supplementary note 7, wherein a transfer surface simulating the fingerprint has multiple concentric concavities and convexities.

Claims (8)

  An artificial fingerprint liquid comprising an oil, water, and a surfactant in an amount of 5% to 46% by weight based on the oil, and being a water-in-oil emulsion.   The artificial fingerprint liquid according to claim 1, wherein the oil is any one of higher fatty acids and derivatives thereof, and terpenes.   The artificial fingerprint liquid according to claim 1, wherein the oil is triolein or squalene.   The artificial fingerprint liquid according to any one of claims 1 to 3, wherein the surfactant is sodium linear alkylbenzene sulfonate.   The artificial fingerprint liquid according to any one of claims 1 to 4, further comprising a powder.   The artificial fingerprint liquid according to claim 5, wherein the powder is Kanto Loam (powder 1 for JIS testing). Applying the artificial fingerprint liquid according to any one of claims 1 to 6 on a substrate and forming a liquid film of the artificial fingerprint liquid on the substrate;
Pressing the rubber having a transfer surface imitating a fingerprint on the liquid film, and transferring the artificial fingerprint liquid to the transfer surface;
Pressing the transfer surface to which the artificial fingerprint liquid is attached to the surface of the evaluation substrate to form an artificial fingerprint mark on the evaluation substrate; and
Wiping off the artificial fingerprint mark;
A method for evaluating fingerprint resistance, comprising:   8. The fingerprint resistance evaluation method according to claim 7, wherein the transfer surface imitating the fingerprint has multiple concentric irregularities.