JP2009156713A - Contact indicator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a contact indicator in which at least a part of fillers having color changeability due to shape anisotropy are vertically oriented and projected from a surface of a coating film and the projected part of the fillers at a press applied portion fall so that the contact is visually observed by the change of the color. <P>SOLUTION: This contact indicator 10 includes a substrate 11 and a coating film 12 that is applied on a surface of the substrate 11 and is cured. The coating film 12 includes a binder 12a and the fillers 12b having color changeability due to shape anisotropy. The fillers 12b are roughly vertically oriented with respect to the surface of the coating film 12 in the binder 12a and at least a part of the fillers are projected from the surface of the coating film 12. The contact indicator is constituted in such a manner that when a pressure is applied to the surface of the coating film 12, the projected part of the fillers 12b on the coating film 12 are deformed so that the color of the surface of the coating film 12 is changed and visually observed. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a touch indicator. More specifically, the present invention relates to a contact indicator that allows a portion where pressure is applied to a surface to be discolored and visually recognized.

Conventionally, as a pressure indicator, what is shown, for example in patent documents 1 and patent documents 2 is known.
Japanese Patent Application Laid-Open No. H10-228561 describes a color density of a film coated with a developer by combining a film coated with a microencapsulated color developer and a film coated with a developer and pressing between the pressure distribution measurement positions. As a pressure measuring film, the film to which the developer is applied uniformly has fine irregularities on the surface, or as a surface plate used for measuring the pressure distribution. A pressure measurement film is disclosed in which a pressure distribution is measured using a material having fine irregularities on the surface. According to the pressure distribution measurement film having such a configuration, an effective area to which a load due to pressure during measurement is applied is reduced due to the above-described fine uneven shape. As a result, the pressure sensitivity in the portion where the load is actually applied is improved, and color development is possible even with a slight pressure.

  By the way, when a coating film is formed using a coating material in which a filler having shape anisotropy is added to a so-called binder, the filler in the coating film is aligned along the coating direction during coating. Will be oriented.

  On the other hand, conventionally, various attempts have been made to form a coating film having a surface provided with protrusions to impart functionality, and the materials and forming methods used for such surface protrusion films are given. There is a wide range of functionality.

  For example, in Patent Document 2, by forming one end of a filler with a magnetic material or a dielectric, a magnetic field is applied to the coating material before the coating material containing the filler applied to the substrate is cured. Alternatively, a submerged coating film is disclosed in which an electric field is applied to orient a filler at a predetermined angle, preferably perpendicular to the surface of a substrate. According to such a submerged coating film, by controlling the orientation of the filler in the coating film, at least a part of the vertically oriented filler protrudes from the surface of the coating material. Thereby, high water repellency is obtained on the coating film surface.

  Further, Patent Documents 3 and 4 disclose coating films in which the orientation of a nonmagnetic or nonferromagnetic glitter pigment is controlled. In Patent Document 3, a coating material containing a glittering pigment dispersed in a resin is applied to a substrate and placed in a strong magnetic field, whereby the orientation of the glittering pigment is controlled and the coating material is cured. Thereby, the designable medium in which the glitter pigment is oriented in a predetermined direction is formed.

  In Patent Document 4, a coating material containing a pigment dispersed in a resin is applied to a base material and placed in a strong magnetic field, and a different magnetic gradient is generated between the pattern forming portion and the periphery thereof, thereby forming a pattern. Different orientation control of the pigment is performed between the formation portion and its periphery, and the coating material is cured. Thereby, the designable medium in which the pigment is oriented in the predetermined direction only at the pattern forming portion is formed.

Japanese Patent Laid-Open No. 06-331467 JP 2006-205001 A JP 2007-054820 A JP 2007-029894 A

However, in the pressure measurement film according to Patent Document 1, the measurable pressure is 1 kg / cm ² or less, but actually, for example, it is limited to a high pressure of about 0.5 kg / cm ² . For this reason, it was impossible to detect a pressure as low as that touched by a finger, for example.

  In the submerged coating film according to Patent Document 2, one end of the filler is made of a magnetic material or a dielectric in order to orient the filler at a predetermined angle in the surface region of the coating material by applying a magnetic field or an electric field. Therefore, a step of bonding a magnetic material or a dielectric to one end of a normal filler by bonding or the like is necessary. For this reason, the cost of a filler will become high.

The filler is oriented at a predetermined angle with respect to the substrate surface by attracting the magnetic material or dielectric bonded to one end by applying a magnetic field or an electric field. However, specific means for causing at least a part of the filler to protrude from the surface is not specified.
Therefore, in this orientation step, the other end of the filler cannot be protruded from the surface of the coating material. Therefore, when the coating thickness of the coating material is longer than the length of the filler, the filler is completely removed from the surface of the coating material. It may not protrude. For this reason, in order to make at least a part of the filler protrude from the surface of the coating material, for example, a process such as wiping or polishing is required. However, the surface of the coating material becomes rough due to the process such as wiping or polishing. Membrane functionality may be lost.

  On the other hand, in the designable medium formed according to Patent Documents 3 and 4, it is possible to orient the filler at least partially at a predetermined angle with respect to the substrate surface, but at least a part of the filler is applied. It is difficult to impart functionality by protruding from the surface of the material.

  In the present invention, in view of the above problems, at least a part of the filler having a color change property based on shape anisotropy protrudes from the surface of the coating film, and the protruding part of the filler collapses at the pressure application part, and the color changes. An object of the present invention is to provide a contact indicator in which contact can be visually recognized.

  In order to achieve the above object, the contact indicator of the present invention comprises a base material and a coating film coated and cured on the surface of the base material, and the coating film has a color change property based on a binder and shape anisotropy. The filler is oriented substantially perpendicular to the surface of the coating film in the binder and at least part of the filler protrudes from the surface of the coating film, and when pressure is applied to the coating film, The surface of the coating film is discolored and observed when the protruding portion of the filler is deformed.

According to the said structure, at least one part of the filler which has the color change property based on shape anisotropy protrudes upwards from the surface of a coating film. Thereby, when observed from the outside, the filler is almost upright and the color in the vertical state is visually recognized.
On the other hand, when a pressure is applied to at least a part of the surface of the coating film, the portion of the filler protruding upward from the surface of the coating film falls down on the surface of the coating film at the pressure application portion. Deforms almost parallel along. Therefore, when viewed from the outside, the filler is in a state of being almost horizontally tilted, and the color in the horizontal state is visually recognized. Thereby, since only the pressure application part changes to a different color when the filler falls, the pressure application part can be easily recognized.

In this case, the pressure that can be detected is such that the portion protruding from the surface of the filler coating film falls down, for example, on the order of 1 g / cm ^2. However, it can be reliably detected.

  In the contact indicator of the present invention, preferably, after the coating film applies a magnetic field to the coating material before the binder is cured, the filler is oriented perpendicular to the substrate surface, and the coating material is cured, The binder is removed by etching a predetermined depth from the surface so that the filler protrudes from the surface of the coating film.

  When the anisotropic magnetic susceptibility of the filler is positive, it receives a larger magnetic force in the longitudinal direction, and the longitudinal direction of the filler is oriented along the direction of the magnetic field lines. When the anisotropic magnetic susceptibility of the filler is negative, the filler has a large magnetic susceptibility in the short direction, so that the short direction of the filler is aligned along the direction of the magnetic field lines. In this case, the filler can be oriented in a specific direction by a predetermined magnetic field as well as a strong magnetic field. On the other hand, even when the filler is a non-magnetic material, it can be oriented by using a strong magnetic field. For this reason, the material of a filler is not restrict | limited by properties, such as magnetism. Further, after the coating material is cured, the binder is removed by etching by a predetermined depth in the surface region of the coating film. Thereby, at least a part of the filler protrudes upward from the surface of the coating film. Therefore, the surface of the coating film is not roughened by a process such as wiping or polishing.

  In the contact indicator of the present invention, preferably, the coating film applies a strong magnetic field perpendicular to the surface of the coating material before the binder is cured, and the filler is oriented perpendicular to the substrate surface, and the magnetic Archimedes The filler suspended by the effect is displaced to the surface region of the coating material, and the coating material is cured. In this case, by applying a strong magnetic field perpendicular to the base material coated with the coating material on the surface, the filler having shape anisotropy is oriented along the direction of the magnetic field lines in the binder before curing. It will receive a magnetic force in the opposite direction of gravity.

  Therefore, the so-called magnetic Archimedes effect occurs in the filler, that is, based on the magnetic force acting directly on the filler, based on the buoyancy due to the specific gravity difference between gravity and the binder, and further on the difference in magnetic susceptibility between the filler and the binder. Magnetic buoyancy acting from the binder acts. And so that these four forces may balance, each filler will deviate in a binder up and down direction.

  In the contact indicator of the present invention, the filler is preferably made of a nonmagnetic material. Even when the filler is made of a non-magnetic material such as a diamagnetic material or a paramagnetic material, it aggregates in the surface region in the binder due to the magnetic orientation and magnetic Archimedes effect described above, and at least a part of the surface of the coating film Projecting upward from

  In the contact indicator of the present invention, the filler is preferably a bright pigment. Thereby, the contact can be visually recognized easily by the change in color tone between the vertical alignment and the horizontal alignment of the glitter pigment.

  In the contact indicator of the present invention, preferably, the protruding portion of the filler is plastically deformed by applying pressure. As a result, the color change due to the application of pressure becomes irreversible, and can be used for security purposes, for example.

  In the contact indicator of the present invention, preferably, the protruding portion of the filler is elastically deformed by applying pressure. As a result, the protruding portion of the filler returns to the original vertical orientation due to the restoring force of the elastic deformation, so that the repeated pressure can be detected.

  According to the present invention, even in the case of a paramagnetic, ferromagnetic or nonmagnetic filler, at least a part of the filler having a color change property based on shape anisotropy protrudes from the surface region of the coating film, Thus, a contact indicator is provided in which the protruding portion of the filler falls down and becomes horizontal to exhibit a different color tone.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In each figure, the same or corresponding members are denoted by the same reference numerals.
FIG. 1 is a schematic sectional view showing the structure of a contact indicator according to the present invention. In FIG. 1, the contact indicator 10 includes a base material 11 and a coating film 12 that is applied and cured on the surface of the base material 11. The coating film 12 is a film obtained by adding a filler 12b to a binder 12a and cured, and is applied to the surface of the substrate 11 in a sufficiently mixed state. At least a part of the filler 12 b protrudes from the coating film 12. Here, the filler 12b has an elongated shape having a high aspect ratio, for example, a shape having shape anisotropy such as a needle shape, a plate shape, and a scale shape.

FIG. 2 is a schematic cross-sectional view showing the state of the contact indicator 10 of FIG. 1 before (A) pressure application and after (B) pressure application.
As shown in FIG. 2A, when a person touches a region A on the surface of the coating film 12 with a finger, pressure is applied to the surface of the coating film 12. For this reason, pressure is applied to the filler 12 b protruding upward from the region A on the surface of the coating film 12. Therefore, the portion of the region A protruding from the surface of the coating film 12 of the filler 12b falls down as shown in FIG. 2B, and becomes almost parallel along the surface of the coating film 12. Thereby, when it observes from the outside, the horizontal state of the filler 12b is observed and the color tone in the horizontal state of the filler 12b is visually recognized.

  In this way, since the protruding portion of the filler 12b falls down and becomes a horizontal state only in the area where pressure is applied on the surface of the coating film 12, the area where the pressure is applied is visually recognized at a glance. Is done.

  As long as the base material 11 in the contact indicator 10 of the present invention is made of a non-magnetic material and can be applied with a plate-like or film-like coating film 12, natural fibers, wood, synthetic resins made of various plastics, metals, ceramics, Various base materials 11 made of glass, cement, silicon compound, biomaterial, or the like can be used. In the present invention, the non-magnetic material is a general term for any of a paramagnetic material, an antiferromagnetic material, and a diamagnetic material.

  As the base material 11 made of a synthetic resin, for example, a film made of PET (polyethylene terephthalate) can be used. Furthermore, polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyvinyl acetate, ethylene / vinyl acetate copolymer, polymethyl methacrylate, ABS resin, AS resin, cellophane, polyacrylonitrile, polymethylpentene, polybutene, Fluorine resin, polyamide, polyacetal, polycarbonate, modified polyphenylene ether, polybutylene terephthalate, cyclic polyolefin, polyphenylene sulfide, polysulfone, polyethersulfone, liquid crystal polyester, polyetheretherketone, polyimide, polyetherimide, polyamideimide, polyarylate, oxy Plastic materials such as benzoyl polyester, polylactic acid, and polycaprolactam can be used.

  As the substrate 11 made of metal, paramagnetic and diamagnetic metals such as aluminum, copper, gold, silver, zinc, gallium, zirconium, antimony, tellurium, lead, palladium, cadmium, bismuth, tin, selenium, Indium or the like can be used. The base material 11 made of metal may use a metal compound, and may be an oxide, nitride, alloy, or the like made of the paramagnetic and diamagnetic metals.

  Here, the binder 12a uses a material that can be easily mixed with the filler 12b and is easily cured in a curing step after coating. Further, when the binder 12a is etched by the method for forming the contact indicator 10 to be described later and the filler 12b protrudes from the surface of the coating film 12, a material having an etching rate higher than that of the filler 12b is used for the binder 12a. That is, the binder 12a is a material that is more easily etched than the filler 12b, and is preferably a material that can be selectively etched.

  As the binder 12a, organic ultraviolet curing type, solvent type, thermoplastic type, thermosetting type resin, sol-gel film made of inorganic metal alkoxide, inorganic polymer, alkaline silicate aqueous solution, or the like is used.

  Examples of the ultraviolet curable binder 12a include unsaturated polyester resin, polyester acrylate, polyether acrylate, epoxy acrylate, urethane acrylate, styrene acrylate, polybutadiene acrylate, and epoxy resin.

  Examples of the solvent-type binder 12a include vinyl resins such as polyvinyl chloride, polyvinyl alcohol, polyvinyl butyral, and polyvinyl acetate, and styrene resins such as polystyrene, acrylonitrile / styrene copolymer, acrylonitrile / butadiene / styrene copolymer, and the like. And ethylene resins such as ethylene / vinyl acetate copolymer, acrylic resins such as polymethyl methacrylate, cellulose resins such as ethyl cellulose, cellulose acetate, and cellulose nitrate, polycarbonates, phenoxy resins, and polyesters.

  Examples of the thermoplastic binder 12a include polyethylene, polypropylene, polyester, polystyrene, polyvinyl formal, polyacetal, polyvinylidene chloride, and nylon.

  Examples of the thermosetting binder 12a include phenol / formaldehyde resin, urea resin, melamine / formaldehyde resin, epoxy resin, furan resin, xylene resin, alkyd resin, silicon resin, diallyl phthalate resin, and the like. When a thermoplastic resin or a thermosetting resin is used as the binder 12a, a heat resistant material needs to be used as the base material 11.

  Examples of the sol-gel film made of metal alkoxide include Si alkoxide, Al alkoxide, other Mg alkoxide, Ti alkoxide, and Zr alkoxide. Examples of the Si alkoxide include trimethylmethoxysilane, dimethyldimethoxysilane, methyltrimethoxysilane, and tetraethoxysilane. Examples of the Al alkoxide include aluminum methoxide, aluminum ethoxide, aluminum isopropoxide, aluminum isobutoxide and the like.

  Examples of the inorganic polymer include polysilazane and perhydropolysilazane.

  The filler 12b is made of metal fine particles such as aluminum, gold, and silver, inorganic materials such as carbon, ITO, zinc oxide, and mica (organic mica), and organic materials such as polymer fine particles.

The filler 12b is made of a material having an etching rate lower than that of the binder 12a when an etching process is used in the method for forming the contact indicator 10 described later. Preferably, a non-magnetic material that does not dissolve by etching and is oriented with respect to a magnetic field and has a color change property based on shape anisotropy, such as a luster pigment, particularly a pearl pigment, can be used. In this case, the filler 12b may be oriented in the direction of the magnetic field lines or the direction perpendicular to the magnetic field lines.
Here, the color change based on the shape anisotropy means that the filler 12b can be visually recognized in different color tones in a substantially vertical state and a substantially horizontal state.

  For the filler 12b, a material made of a non-magnetic material that is paramagnetic, diamagnetic, or antiferromagnetic can be used. When the magnetic Archimedes effect is used for the magnetic field orientation of the filler 12b, the filler 12b may be made of a nonmagnetic material having a positive anisotropic magnetic susceptibility that is oriented perpendicular to the vertical magnetic field. Further, the mass magnetic susceptibility of the filler 12b is a positive value for the paramagnetic material and a negative value for the diamagnetic material. Furthermore, when the magnetic Archimedes effect is not used for the magnetic field orientation of the filler 12b, a nonmagnetic material having a negative anisotropic magnetic susceptibility can be used as the filler 12b.

Give examples of mass susceptibility. The mass magnetic susceptibility of SiO ₂ is −0.493 × 10 ⁻⁶ m ³ / kg diamagnetic material, and the mass magnetic susceptibility of Al ₂ O ₃ is −0.363 × 10 ⁻⁶ m ³ / kg. It is a diamagnetic material, MnCl _{2 has} a mass magnetic susceptibility of 114 × 10 ⁻⁶ m ³ / kg, and Fe ₃ O _{4 has} a mass magnetization of 91.2 Gm ³ / kg. is there.
Even if the absolute value of the mass magnetic susceptibility is 10 ⁻³ m ³ / kg or less, if the magnetic field H is a strong magnetic field, the filler 12b made of a non-magnetic material is magnetically oriented to form the coating film 12. Oriented perpendicular to the surface of the substrate.

When the binder 12a is made of an organic material such as polyethylene and the binder 12a is dissolved by oxygen plasma etching, the filler 12b is made of an inorganic material such as silica or metal, or a material having a low etching rate such as polyimide. The
When the binder 12a is made of an organic material such as polystyrene, the binder 12a can be etched with a solvent. In this case, the filler 12b is made of an inorganic material that does not dissolve in the solvent or a material such as a fluororesin.
Further, when the binder 12a is made of an inorganic material and the binder 12a is etched with acid, alkali, or the like, the filler 12b is made of a material that is durable and insoluble with respect to the acid, alkali, or the like. When the binder 12a is, for example, SiO _2, as the filler 12b and the like can be used polyethylene.

  In the above-described embodiment, the filler 12b is made of a non-magnetic material, but it is obvious that the filler 12b may be made of a ferromagnetic material.

  The contact indicator 10 of the present invention is configured as described above, and the contact indicator 10 is provided so that even the non-magnetic filler 12b is biased to protrude from the surface of the coating film 12. Is done.

According to the contact indicator 10 of the present invention, at least a part of the filler 12 b having a color change property based on shape anisotropy protrudes upward from the surface of the coating film 12. Thereby, when observed from the outside, the filler 12b is almost upright, and the color in the vertical state is visually recognized.
On the other hand, when a pressure is applied to at least a part of the surface of the coating film 12, the portion of the filler 12b protruding upward from the surface of the coating film 12 in this pressure application portion falls down due to the pressure, and the coating is performed. The film 12 is deformed substantially parallel along the surface of the film 12. Therefore, when observed from the outside, the color of the horizontal state is visually recognized when the filler 12b is almost horizontally tilted. For this reason, since the filler 12b falls only in the pressure application portion and changes to a different color, the pressure application portion can be easily recognized.

  In the contact indicator 10, when the filler 12b is plastically deformed by the application of pressure, the color does not return to the original color after being discolored by a single contact, so that it can be used for security purposes, for example.

  In the contact indicator 10, when the filler 12b is elastically deformed by applying pressure, after the pressure is applied and deformed to change the color tone, the filler 12b is restored to the original vertical state and returns to the original color tone. Can be used repeatedly.

The pressure that can be detected by the contact indicator 10 of the present invention is such that the portion of the filler 12b protruding from the surface of the coating film 12 falls down, for example, on the order of 1 g / cm ² , so a slight pressure, for example, a human finger touches. Even a small pressure can be reliably detected.

Next, the 1st formation method of the contact indicator 10 by embodiment of this invention is demonstrated.
FIG. 3 is a flowchart showing a first method for forming the contact indicator 10.
In step S1, a coating material is produced by adding and mixing the filler 12b in the binder 12a.

Subsequently, in step S <b> 2, this coating material is applied to the surface of the substrate 11.
Here, as a coating method of the coating material to the base material 11, spray method, brush coating, gravure printing, screen printing, flexographic printing, direct gravure coating, gravure reverse coating, micro gravure coating, roll coating, die coating, spin coating , Wire bar coating, knife coating, air knife coating, curtain coating, dip coating, comma coating and the like.

  The binder 12a can be easily mixed with the filler 12b, and can be easily cured in a curing step after coating, and uses a material having a relatively higher etching rate than the filler 12b in an etching step described later. That is, the binder 12a is a material that is more easily etched than the filler 12b, and is preferably a material that can be selectively etched.

  Thereafter, in step S3, the base material 11 coated with the coating material is placed in the magnet, the magnet is operated, and the magnetic field H is applied for a predetermined time.

FIG. 4 is a schematic cross-sectional view showing each state of the contact indicator 10 of FIG. 1 when (A) and (B) start applying a magnetic field before curing and (C) after applying a magnetic field.
As shown in FIG. 4A, in the contact indicator 14 before curing, the filler 12b is applied by applying a magnetic field H in the vertical direction of the substrate 11 after the coating material is applied to the surface of the substrate 11. As shown in FIG. 4C, the substrate 11 is oriented in the vertical direction. As shown in FIG. 4B, in the contact indicator 14 before curing, the filler 12b is applied by applying a magnetic field H in the horizontal direction of the base material 11 after the coating material is applied to the surface of the base material 11. The substrate 11 may be oriented vertically as shown in FIG.

FIG. 5 is a partially broken perspective view showing a magnetic field applying step by the magnet 20 in the step of forming the contact indicator 10 of FIG. 1, and FIG. 6 is a partially enlarged sectional view showing the inside of the magnet 20.
As shown in FIGS. 5 and 6, the application of the magnetic field H is specifically performed by using a magnet 20. As shown in the drawing, the coating film 14 before curing is disposed in the magnet 20. As the magnet 20, a permanent magnet or an electromagnet can be used. In particular, when it is necessary to generate a strong magnetic field H ′, a superconducting magnet can be used.
Here, the magnet 20 is configured in a hollow cylindrical shape, and an upward magnetic field H is generated in the hollow portion 21 extending in the vertical direction. Thereby, the magnetic field H is applied with respect to the coating material by arrange | positioning the base material 11 which apply | coated the coating material in the hollow part 21 as mentioned above.

  Next, in step S4, the binder 12a of the coating material is cured by an appropriate method while the magnetic field H is being applied in the hollow portion 21 of the magnet 20. For example, when an ultraviolet curable resin is used as the binder 12a, the binder 12a is cured by irradiating the base material 11 coated with the coating material with ultraviolet rays. Moreover, when using a thermosetting resin as the binder 12a, you may harden | cure by irradiating heat from heat sources, such as infrared rays. In this way, the filler 12b is fixedly held in the binder 12a in a state where the filler 12b is oriented in the vertical direction in the coating film 12.

  Subsequently, the application of the magnetic field is stopped, and after the base material 11 on which the coating film 12 is formed is taken out from the hollow portion 21, the binder 12a is etched by a predetermined depth from the surface of the coating film 12 in step S5. Removed. That is, in FIG. 4B, only the binder 12a in the coating film 12 is removed by etching within a range from the surface of the coating film 12 on the upper side from the chain line C to a predetermined depth.

For the etching, an appropriate method such as dry etching or wet etching is selected according to the material of the binder 12a and the filler 12b so that the etching rate is high with respect to the binder 12a and the etching rate is low with respect to the filler 12b. The
As a result, many fillers 12b protrude from the surface on the new surface formed by etching of the coating film 12 with much of the filler 12b oriented in the vertical direction in the coating film 12. In this way, the contact indicator 10 is completed by performing the etching (see step S6).

  As the magnetic force, magnetic levitation by the magnetic Archimedes effect may be used. In this case, a strong magnetic field H 'of about 0.5 Tesla (T) or more is required to magnetically levitate the nonmagnetic filler 12b. A superconducting magnet 20 can be used to generate the strong magnetic field H ′.

  According to the first method of forming the contact indicator 10, by applying the magnetic field H before the binder 12a is cured, the filler 12b made of, for example, a non-magnetic material in the binder 12a is oriented in a direction perpendicular to the substrate. . The filler 12b protrudes from the surface of the binder 12a by the etching process after the binder 12a is cured. For this reason, more fillers 12b can be protruded upward from the surface of the coating film 12 than when the filler is simply applied and oriented.

Next, the 2nd formation method of the contact indicator 10 by embodiment of this invention is demonstrated.
FIG. 7 is a flowchart showing a second method of forming the contact indicator 10.
In step S11, the filler 12b is added and mixed in the binder 12a, thereby producing a coating material to be the coating film 12.

In step S12, as shown in FIG. 2A, this coating material is applied to the surface of the substrate 11.
In step S13, the base material 11 coated with the coating material is placed in the hollow portion 21 of the superconducting magnet 20 as shown in FIG. 5, and the superconducting magnet 20 is operated to generate the strong magnetic field H ′ for a predetermined time. Apply. Thereby, as shown in FIG. 6, the filler 12b is oriented along the direction of the magnetic lines of force, and at the same time, is offset to the surface region of the coating material by the magnetic Archimedes effect. Therefore, at least a part of the filler 12b protrudes from the surface in the surface region of the binder 12a.

  Next, in step S14, the binder of the coating material is applied by an appropriate method to the base material 11 coated with the coating material while the strong magnetic field H ′ is applied in the hollow portion 21 of the superconducting magnet 20. 12a is cured. For example, when an ultraviolet curable resin is used as the binder 12a, the binder 12a is cured by irradiating the base material 11 coated with the coating material with ultraviolet rays. Moreover, when using a thermosetting resin as the binder 12a, you may harden | cure by irradiating heat from heat sources, such as infrared rays. In this way, the filler 12b is oriented in the vertical direction in the coating film 12 and displaced to the surface region, and is fixedly held in a state in which at least a part thereof protrudes from the surface.

  Finally, in step S15, the superconducting magnet 20 is stopped, and the base material 11 on which the coating film 12 is formed is taken out from the hollow portion 21, whereby the contact indicator 10 is completed.

  The second forming method of the contact indicator 10 is different from the first forming method described above in that the filler 12b in the binder 12a is magnetically levitated by applying a strong magnetic field H ′ in step S14, and at least in the surface region. This is because part of it protrudes from the surface. Therefore, the etching used in step S5 of the first formation method is not performed.

The magnetic levitation using the strong magnetic field H ′ in step S14 will be described.
FIG. 8 is a schematic diagram showing magnetic field application and magnetic field gradient by the magnet 20 of FIGS. 5 and 6. The magnet 20 will be described as using a superconducting magnet for applying the strong magnetic field H ′.
As shown in FIG. 8, it is known that a magnetic gradient is generated in the hollow portion 21 in the superconducting magnet 20 in the vertical direction. As is apparent from the graph on the right side of FIG. 8, this magnetic field gradient gives a maximum value at a position shifted from the magnetic center O in the vertical direction. Accordingly, the base material 11 coated with the coating material is disposed at a position shifted from the magnetic center O by a distance d, for example, so that the filler 12b is positioned near the maximum value of the magnetic gradient.
Thereby, the maximum magnetic Archimedes effect acts on the filler 12b by being arranged near the maximum value of the magnetic gradient. In this case, the filler 12b has different magnetic susceptibility depending on its direction, and when the filler 12b has a large magnetic susceptibility in the longitudinal direction, the longitudinal direction is oriented along the direction of the lines of magnetic force.

That is, as shown in FIG. 8, the buoyancy F2 due to the gravity difference between gravity F1 and the binder 12a is acting on the filler 12b, and the magnetic force acting directly on the filler 12b by the above-described strong magnetic field H ′. The force F3 and the magnetic buoyancy F4 acting from the binder 12a act.
Here, the magnetic force F3 and the magnetic buoyancy F4, that is, the magnetic force F by the strong magnetic field H ′ is given by the following equation (1).
Magnetic force F = density × mass susceptibility × magnetic field strength × magnetic gradient (1)
Therefore, in order to increase the magnetic force F from the equation (1), the difference in mass magnetic susceptibility between the medium binder 12a and the medium filler 12b is increased, the magnetic field strength is increased, and the magnetic gradient is increased. is important.
In order to increase the difference in mass magnetic susceptibility between the binder 12a and the filler 12b as a medium, for example, it is desirable that one is a paramagnetic material and the other is a diamagnetic material.

  Then, by appropriately selecting the strong magnetic field H ′ according to the balance between the buoyancy F2, the magnetic force F3, the magnetic buoyancy F4, and the gravity F1, the filler 12b is vertically oriented in the binder 12a and displaced upward. be able to. As a result, the filler 12b is oriented in the direction of the magnetic field lines of the strong magnetic field H ′, that is, in the vertical direction, and is displaced upward in the binder 12a to its surface region, and a part of the filler 12b protrudes from the surface of the binder 12a. To be done.

Here, the value of the magnetic field is preferably a magnetic flux density of 1 Tesla (T) or more at the center of the magnetic field, although it depends on the mass magnetic susceptibility. Such a magnetic field can be generated by the superconducting magnet 20. If the absolute value of the mass magnetic susceptibility of the filler 12b is a fine particle made of a material of 10 ⁻³ m ³ / kg or less, by applying a strong magnetic field H ′ of 1 Tesla or more, the filler 12b is bonded to the binder 12a by the magnetic Archimedes effect. It can be displaced to any region, especially the surface region.

  When the filler 12b is made of a diamagnetic material, the filler 12b receives a force repelling the magnetic field. When the coating material is placed above the center of the magnetic field, if the repulsive force of the filler 12b is stronger than the gravity, the filler 12b is separated into the upper part of the film made of the coating material. When the binder 12a is a paramagnetic material, the binder 12a is attracted to the center of the magnetic field, so that the separation of the filler 12b to the upper part of the coating film 12 is further promoted.

  When the filler 12b is a material made of a paramagnetic material or an antiferromagnetic material, the filler 12b receives a force attracted by a magnetic field. When the coating material is placed below the center of the magnetic field, the filler 12b is separated at the top of the coating material.

For the filler 12b, a material having a color change property based on shape anisotropy, for example, a luster pigment mainly composed of a non-magnetic material such as mica, silica, or alumina can be used. The mass magnetic susceptibility of such a luster pigment is a positive value for a paramagnetic material and a negative value for a diamagnetic material. For example, when made of a diamagnetic material, the mass magnetic susceptibility of the filler 12b is 10 ⁻⁶ m ³ / kg or less and has magnetic anisotropy.

As a result, even in the case of fine particles made of a nonmagnetic material having an absolute value of mass magnetic susceptibility of 10 ⁻³ m ³ / kg or less, the magnetic Archimedes effect is generated by the application of the strong magnetic field H ′. Bright pigments and the like are reliably displaced.
In the above-described embodiment, the filler 12b is made of a non-magnetic material. However, it is obvious that the filler 12b may be made of a ferromagnetic material.

According to the second method of forming the contact indicator 10, the filler 12b is displaced near the surface of the coating material using the magnetic Archimedes effect by applying the strong magnetic field H ′. Not limited to this, the base material 11 is reversed and disposed so that the coating material is located below the base material 11 in the superconducting magnet 20, and the filler 12b is displaced downward to make the coating material It is also possible to adjust the amount of protrusion of the filler 12b from the surface of the coating material by shifting to the surface region or adjusting the balance of the four forces F1 to F4 by appropriate control of the superconducting magnet 20. Is possible.
In this way, in the coating material, the filler 12b is displaced to the surface region, so that at least a part of each filler 12b protrudes from the surface of the coating film 12.

  According to the method for forming the contact indicator 10 of the present invention, it is possible to produce the contact indicator 10 that is projected from the surface of the coating film 12 even with the non-magnetic filler 12b. According to the contact indicator 10 produced in this way, a part of the filler 12b protrudes from the surface of the coating film 12 so that the vertical state of the filler 12b is observed when observed from the outside. Thus, the color tone of the filler 12b in the vertical state is visually recognized.

Hereinafter, the present invention will be described in more detail with reference to examples.
In the contact indicator 10 of the example, an ultraviolet curable resin (manufactured by T & K TOKA, UV flexonis) is used as the binder 12a, a glitter pigment (manufactured by Shiseido, Infinite R08) is used as the filler 12b, and the substrate 11 As a PET film.

  As the magnet 20, a superconducting magnet (manufactured by Sumitomo Heavy Industries, Ltd., split type HF5-100VT-50HT) was used.

FIG. 9 is a graph showing the magnetic flux density distribution and magnetic gradient of the superconducting magnet 20 used in the specific embodiment of the contact indicator 10 of FIG. The horizontal axis in FIG. 9 is the position (cm) from the center of the superconducting magnet 20, the left vertical axis is the magnetic flux density (T), and the right vertical axis is the magnetic gradient (T ² / m). Here, the magnetic gradient is represented by Bz × (dBz / dZ), and Bz is the magnetic flux density when the position is z.
As shown in FIG. 9, the superconducting magnet 20 has a magnetic flux density of 5 to 6 Tesla in the vicinity of the magnetic field center, and the magnetic gradient is maximized at a position shifted from the position at which the magnetic flux density is maximized. I understand.

  A coating material was prepared by mixing 90 parts of the binder 12a and 10 parts of the filler 12b, and this coating material was applied onto the substrate 11 with a wire bar to obtain a coating film 15 before curing.

  This uncured coating film was placed in the hollow portion 21 of the superconducting magnet 20 and allowed to stand in a magnetic field H of 3 Tesla for 3 minutes for magnetic field orientation to vertically align the filler 12b. Thereafter, the binder 12a was cured by ultraviolet irradiation in a magnetic field to form a coating film 12 having a thickness of about 50 μm. Subsequently, the cured coating film 12 is subjected to oxygen plasma treatment for 10 minutes, thereby removing the binder 12a having a thickness of 20 μm by etching to produce the contact indicator 10 having the coating film 12 having a thickness of about 30 μm. did.

Next, the comparative example with respect to an Example is demonstrated.
(Comparative example)
The binder film 12a was cured by irradiating with ultraviolet rays without applying the magnetic field H to the coating film before curing as in the example to form a coating film having a thickness of 50 μm. Subsequently, this coating film was subjected to oxygen plasma treatment for 10 minutes to remove about 20 μm of the binder 12a having a thickness of about 20 μm, thereby producing a comparative coating film having a thickness of about 30 μm.

In the examples and comparative examples, the manufactured contact indicator 10 and the coating film were observed.
FIG. 10 shows a scanning electron microscope image in a cross section of the contact indicator 10 of the example. The acceleration voltage of the scanning electron microscope is 15 kV, and the magnification is 1500 times.
As is clear from FIG. 10, in the contact indicator 10 of the example, the contact indicator 10 having a thickness of about 30 μm is formed on the substrate 11, and the filler 12 b is oriented perpendicular to the surface of the substrate 11. At the same time, it can be seen that fine protrusions are formed by the filler 12 b protruding from the surface of the coating film 12 and exposed on the surface of the coating film 12.
Thereby, when observed from the outside, the color tone of red beans was observed, and the color tone changed to a blue-purple color tone only at the place where pressure was applied to the coating film surface.

  FIG. 11 shows a scanning electron microscope image of the cross section of the coating film formed in the comparative example. As is apparent from FIG. 11, in the case of the coating film of the comparative example, it can be seen that the fillers 12b are uniformly scattered in the binder 12a and lie along the coating direction, and do not protrude from the surface. As a result, a blue-purple color tone was observed when observed from the outside, and no change in color tone was observed even at a location where pressure was applied to the surface of the coating film.

  The present invention is not limited to the above-described embodiment, and various modifications are possible within the scope of the invention described in the claims. For example, the binder 12a and the filler 12b to be used are used for the contact indicator 10. It can be set according to the purpose, and it goes without saying that these are also included in the scope of the present invention.

  The contact indicator according to the present invention is such that the protruding portion of the filler collapses at a place where pressure is applied by shifting the filler to the surface region of the substrate and causing at least a portion to protrude from the surface of the coating film, Since the filler having the color change property based on the shape anisotropy is discolored, the pressure application location is easily and reliably detected.

It is a schematic sectional drawing which shows the structure of the contact indicator by this invention. 2A and 2B are schematic cross-sectional views of the contact indicator of FIG. 1, (A) shows a state before pressure is applied, and (B) shows a state after pressure is applied. FIG. 3 is a flowchart showing a first method of forming a contact indicator. In the contact indicator of FIG. 1, (A) and (B) are schematic cross-sectional views showing respective states at the start of magnetic field application before curing and (C) after application of the magnetic field. It is a partially broken perspective view which shows the magnetic field application process by the magnet in the formation process of the contact indicator of FIG. It is a partial expanded sectional view which shows the inside of the magnet of FIG. It is a flowchart which shows the 2nd formation method of a contact indicator. It is the schematic which shows the magnetic field application and magnetic field gradient by the magnet of FIG.5 and FIG.6. 2 is a graph showing magnetic flux density distribution and magnetic gradient of a superconducting magnet used in a specific example of the contact indicator of FIG. It is a figure which shows the scanning electron microscope image in the cross section of the contact indicator of an Example. It is a figure which shows the scanning electron microscope image of the cross section of the coating film formed in the comparative example.

Explanation of symbols

10: Contact indicator 11: Base material 12: Coating film 12a: Binder 12b: Filler 14: Contact indicator before curing 20: Magnet (superconducting magnet)
21: Hollow part

Claims (7)

A substrate and a coating film coated and cured on the surface of the substrate;
The coating film contains a binder and a filler having a color change property based on shape anisotropy,
The filler is oriented substantially perpendicular to the surface of the coating film in the binder, and at least part of the filler protrudes from the surface of the coating film,
The contact indicator, wherein when a pressure is applied to the coating film, the surface of the coating film is discolored and observed due to deformation of a protruding portion of the filler in the coating film.   The coating film applies a magnetic field to the coating material before the binder is cured to orient the filler perpendicularly to the substrate surface, and after the coating material is cured, the filler protrudes from the surface of the coating film. The contact indicator according to claim 1, wherein the binder is removed from the surface by a predetermined depth by etching.   The coating film applies a strong magnetic field perpendicular to the surface of the coating material before the binder is cured, the filler is oriented perpendicular to the substrate surface, and the filler suspended by the magnetic Archimedes effect is applied to the coating material. The contact indicator according to claim 1, wherein the contact indicator is deviated to a surface area of the coating material to cure the coating material.   The contact indicator according to claim 2, wherein the filler is made of a non-magnetic material.   The contact indicator according to claim 1, wherein the filler is a glitter pigment.   The contact indicator according to claim 1, wherein the protruding portion of the filler is plastically deformed by applying pressure.   The contact indicator according to claim 1, wherein the protruding portion of the filler is elastically deformed by application of pressure.