JPH11188427A - Method for producing fine metal pieces with embossed pattern - Google Patents

Abstract

(57) [Problem] To provide a method for producing a metal fine piece with an embossed pattern, which can improve the productivity by a simple process and reduce the cost. A mold having an embossed pattern on its surface.
Then, the emboss pattern is transferred to the metal foil 12 by pressing both sides of the metal foil 12. As described above, the metal foil 12 to which the embossed pattern has been transferred is immersed in the liquid while being adhered to the mold 10, and the ultrasonic wave is applied to separate and crush the metal foil 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a method for producing embossed metal fine pieces used as a material for a hologram pigment.

[0002]

2. Description of the Related Art Metal flakes having an embossed pattern have been known as materials for hologram pigments. For example, Japanese Patent Publication No. 8-502301 discloses a method for producing a metal flake pigment with an embossed pattern.
FIG. 8 is an explanatory diagram of the manufacturing method of the conventional example. In FIG. 8, a release coating 52 that is soluble in a predetermined solvent is formed on a surface of the carrier sheet 50 having an embossed pattern on at least one surface where the embossed pattern is formed. This release coating 52 is formed to a uniform thickness by an applicator 54. On the release coating 52, a metal film is attached so that the embossed pattern of the carrier sheet 50 is transferred. Next, release coating 5
2 is solubilized with a predetermined solvent, and the metal film with an embossed pattern formed thereon is peeled off. The embossed metal film thus obtained was pulverized,
Subdivide into embossed flakes having an average diameter in the range of ５０50 μm. As described above, a metal flake with an embossed pattern can be obtained, and a pigment is manufactured using the metal flake.

[0003]

However, in the above-mentioned conventional manufacturing method, a release coating 52 is formed on the surface of the carrier sheet 50 on which the embossed pattern is formed, and a metal film is further formed thereon. Is solubilized to peel off the metal film, and the metal film is pulverized to obtain a flake. For this reason, there was a problem that the manufacturing process was long, complicated, and the productivity was poor. In particular, in the step of depositing the metal film on the release coating 52, vacuum evacuation equipment and a vacuum container are required, such as evaporating after evacuation in a vacuum vessel. It costs. Further, in the step of removing the metal film, the release coating 52 is solubilized using a solvent or the like. Therefore, the manufacturing process is very complicated as described above.

The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to provide a method of manufacturing a metal fine piece with an embossed pattern, which can improve productivity by a simple process and reduce costs. To provide.

[0005]

In order to achieve the above-mentioned object, the present invention provides a method for producing a fine metal piece with an embossed pattern, comprising pressing a mold having an embossed pattern on both surfaces of a metal foil. An embossed pattern is formed on the surface of the metal foil.

In the above method for producing a fine metal piece with an embossed pattern, the metal foil pressed to a thickness of less than 2 μm is dipped in a liquid while adhering to the die, and ultrasonic waves are applied. And pulverization into a thin piece of less than 50 μm at the same time as release.

[0007] The surface tension of the liquid is set at 0.1.
It is characterized by being less than 04 N / m.

[0008] Further, the present invention is characterized in that the metal foil is pre-cooled to -50 ° C or lower before the pulverization.

[0009] Further, when the mold is pressed against the metal foil,
The surface energy of at least one of the metal foil and the mold is reduced.

Further, the metal foil is characterized in that the pinhole below the diameter 10nm is present in 9000 or less density of 800 or more in an area of 1 mm ^2.

Further, the method is characterized in that a surfactant is applied to the metal foil against which the mold has been pressed, immersed in a liquid, and then crushed by applying ultrasonic waves.

Further, in the above-mentioned method for producing a metal fine piece with an embossed pattern, the die is pressed against both surfaces of a metal foil while sequentially applying pressure to the die with a rolling roll.

[0013] Further, the present invention is characterized in that the rotation direction of the rolling roll coincides with the longitudinal direction of the embossed pattern of the mold.

Further, a tensile stress absorbing plate is disposed between the rolling roll and the mold.

[0015]

Embodiments of the present invention (hereinafter referred to as embodiments) will be described below with reference to the drawings.

Embodiment 1 1 (a), (b),
(C) and (d) show steps of a method for producing a metal fine piece with an embossed pattern according to the present embodiment. FIG. 1 (a)
, A Ni original plate having an embossed pattern (hereinafter referred to as an embossed pattern) is used as a mold 10 and the mold 10 is pressed against both surfaces of a metal foil 12 such as an aluminum foil by pressing. As a result, as shown in FIG.
Asperities of the emboss pattern are formed on the surface of the metal foil 12. As the pressing pressure in this case, when the metal foil 12 is an aluminum foil, a surface pressure of 550 MPa or more is required. Below this pressing pressure, the transfer of the emboss pattern becomes insufficient. The material of the mold 10 is not limited to Ni, but may be, for example, Fe, W, tool steel, or the like.

Next, as shown in FIG.
The metal foil 12 to which the embossed pattern obtained in (b) is transferred is immersed in a predetermined liquid while being adhered to the mold 10, and ultrasonic waves are applied by an ultrasonic cleaner (homogenizer) to form the metal foil 12 into the mold 10. And at the same time, pulverize into flakes of less than 50 μm. Through the above steps, as shown in FIG. 1D, metal fine pieces having an embossed pattern used as a hologram pigment are manufactured.

The metal foil 12 to which the emboss pattern is transferred
Is preferably less than 2.0 μm.
This is because when the thickness is more than this, light is reflected by the fractured surface, and it becomes whitish when used as paint,
This is because the quality as a hologram pigment deteriorates. Further, when the thickness is increased, there is a problem that it is difficult to pulverize the metal foil 12.

As described above, grinding of the metal foil 12 after pressing is performed by applying ultrasonic waves in a solvent such as acetone.
The particle size of the flakes (hologram pigment) after pulverization is desirably 50 μm or less. If it exceeds 50 μm, there is a problem that the surface of each flake is warped and the finished surface after applying the hologram pigment is not flat. Further, when the average particle size of the crushed flakes is 50 μm or more, when this is used as a hologram pigment, there is a problem that the flakes are clogged with a spray gun or the like in a subsequent coating process.

FIG. 2 shows that the metal foil 12 has a thickness of 0.4 μm.
The relationship between the average particle size of the crushed flakes and the ultrasonic wave application time when ultrasonic waves are applied in acetone and pulverization is performed using an aluminum foil of m m is shown. In FIG.
The average particle diameter is indicated by ●, and 2σ (a range in which 95% or more is included) is indicated by ×. As can be seen from FIG.
In order for the following flakes to be 95% or more, a pulverization time of about 150 minutes or more is required.

FIG. 3 shows the above-mentioned 150 times as the grinding time.
In the case where the amount is adopted, the relationship between the thickness of the aluminum foil as the metal foil 12 and the average particle size of the flakes after pulverization is shown. When the pulverization time is 150 minutes, the average particle size is 50 μm as described above.
It can be seen that the thickness of the aluminum foil needs to be less than 2 μm in order to achieve the following.

As described above, 50 μm for improving the quality as a hologram pigment and preventing clogging of a spray gun or the like.
In order to secure a particle size of not more than m, the thickness of the metal foil 12 to which the emboss pattern has been transferred is preferably less than 2 μm.

The thickness of the metal foil 12 is preferably set to 0.1.
When using a mold having a size of 4 to 1 μm, it is preferable that the direction of the emboss pattern of the mold 10 is parallel between the upper mold and the lower mold. This is because if not parallel, the convex and concave portions of the emboss pattern of the upper mold and the lower mold interfere with each other,
It is considered that a place where the emboss pattern transferred to the metal foil 12 is crushed, and the interference light is weakened. On the other hand, when the directions of the emboss patterns of the upper mold and the lower mold were made parallel, the emboss pattern transferred to the metal foil 12 was not broken, and the interference light could be increased.

Also, when the mold is released from the mold 10 by applying ultrasonic waves, the surface of the metal foil 12 may be disturbed, which causes a problem that the interference light when the hologram pigment is formed is weakened. In order to suppress the disturbance of the surface of the metal foil 12 at the time of releasing the mold and to enhance the interference light, it is necessary to improve the releasability of the metal foil 12 from the pressed mold 10. For this purpose, it is preferable that at least one of the mold 10 and the metal foil 12 has a low surface energy. Table 1
Table 2 shows the results when the surface treatment of the mold 10 was performed, and Table 2 shows the results when the surface treatment of the metal foil 12 was performed.

[0025]

[Table 1]

[Table 2] In Tables 1 and 2, CF ₃ (CF ₂ ) ₇ Si (OCH ₃ ) ₃ and C _{2 were} used as surface treatment agents (release agents) for the mold 10.
The case where H ₅ Si (OCH ₃ ) ₃ is used is shown.
As a comparative example, a result of pressing without surface treatment is also shown. In Tables 1 and 2, CF ₃ (C
The surface energy when surface-treated with F ₂ ) ₇ Si (OCH ₃ ) ₃ is 0.015 N / m, and C ₂ H ₅ Si (OC
Surface energy in the case of surface treatment with H _{3) 3} is 0.04N
/ M, the surface energy is lower than that of the untreated comparative example. Therefore, in each case, the interference color is improved. Here, 表 of the interference color in Tables 1 and 2 indicates that the interference light was intensified as compared with the case where the surface treatment was not performed, and that the interference color was extremely good.
The surface treatment was performed by immersing the mold 10 or the metal foil 12 in a 2% solution of the surface treatment agent shown in Tables 1 and 2,
Performed by heating to 0 ° C.

When the surface of the metal foil 12 is treated with a surface treating agent, the mold 10 and the metal foil 12 can be easily released.
Therefore, as shown in Table 2, the interference color became good. In addition, since the flakes of the metal foil 12 do not adhere to each other during or after the pulverization, the pulverizability and the dispersibility of the hologram pigment can be improved.

Furthermore, when the metal foil 12 was pressed, the transferability of the emboss pattern could be improved when the metal foil 12 was heated to 300 ° C., for example, when aluminum foil was used, compared to when the pressing was performed at room temperature. Therefore, 300
The interference light was stronger in the one pressed at ℃ than in the one pressed at room temperature.

As described above, the metal foil 12 is pulverized by immersing the metal foil 12 in a predetermined liquid with the metal foil 12 adhered to the mold 10 and applying ultrasonic waves thereto. Thereby, peeling and pulverization of the metal foil 12 from the mold 10 can be performed simultaneously. Examples of the liquid used in this case include organic solvents such as acetone and ethanol, and the surface tension thereof is preferably less than 0.04 N / m. FIG. 4 shows the relationship between the average particle size of the flakes and the surface tension of the liquid used at the time of grinding for 150 minutes by ultrasonic waves. As shown in FIG. 4, when water having a surface tension of about 0.07 N / m is used as a liquid, the average particle size of the crushed flakes is about 90 μm, which is a desirable particle size for use in a hologram pigment. 50 μm
It has greatly exceeded the following. On the other hand, when an organic solvent having a surface tension of less than 0.04 N / m is used as a liquid, the average particle size of the crushed flakes is 5
It is below 0 μm. In the case of ethyl salicylate having a surface tension of about 0.04 N / m, the average particle size of the ground flakes is about 50 μm. From the above, it can be seen that the surface tension of the liquid used when pulverizing the metal foil 12 is desirably less than 0.04 N / m. This is because oil usually adheres to the surface of the metal foil 12 such as an aluminum foil, and the oil adhering to the surface hinders the pulverization by ultrasonic waves. It is considered that the pulverizing effect can be improved. It is considered that the surface tension of the liquid that can dissolve such an oil and wet the surface of the metal foil 12 is less than about 0.04 N / m.

When the metal foil 12 such as an aluminum foil is pre-cooled before being pulverized by ultrasonic waves, the undulation of the pulverized flakes after pulverization is reduced as compared with pulverization at room temperature. In this case, the interference light can be increased. This is presumably because the pre-cooling of the metal foil 12 makes the metal foil 12 brittle at low temperature and easily crushed. When pre-cooled to -50 ° C or lower, the metal foil 12 becomes hard, so the mold 1
Deformation is suppressed when the metal foil 12 is released from 0,
As described above, the reduction in the undulation of the crushed flakes is also considered to be a cause of the improvement in the interference light.

Table 3 shows the interference colors when the pre-cooling temperature is changed. In Table 3, the interference color of ◎ is also ○.
It shows that it was recognized as good with a significant difference compared to.

[0031]

[Table 3] As shown in Table 3, with ethanol + dry ice-
The interference color is better for the one pre-cooled to −60 ° C. than for the case pre-cooled to 40 ° C. For this reason, it is considered necessary to set the pre-cooling temperature to about −50 ° C. or less.

Next, as described above, it is considered that the particle size of the pulverized flakes is desirably less than 50 μm. On the other hand, if the average particle size is less than 15 μm, the particle size is too small to give a sufficient interference color as a hologram pigment. I can't get it. Therefore, the range of the particle size of the ground flakes is 15 μm.
It is considered that m to 50 μm is preferable. So, next,
A method for controlling the particle size will be described.

The aluminum foil used as the metal foil 12 usually has a pinhole having a diameter of 10 nm or less. When the aluminum foil is crushed by ultrasonic waves, it is considered that the crack propagates through the pinhole, and the aluminum foil is crushed by this. Therefore, if the number of pinholes is controlled in an appropriate range, the particle size of the flakes after pulverization can be controlled to a predetermined size. As shown in FIG.
If a 1 mm (100 μm) square area is considered, four flakes having a particle size of 50 μm on a side are included in this area. In order to pulverize each flake with a size of 50 μm on a side, it is advantageous to have one pinhole on one side of the flake. Since each flake shares four sides with the adjacent flake, on average, two pinholes are assigned to one flake. Therefore, eight pinholes are allocated to a region having one side of 0.1 mm. For this reason,
In the case of an area of 1 mm ² , the number of pinholes is 100 times the above. This is represented by the following general formula.

[0034]

(Equation 1) In the above equation, d is the particle size of the flake, and N is the number of preferred pinholes present in an area of 1 mm ² of the aluminum foil.

As described above, if the particle size of the flakes is 50 μm or more, a spray gun or the like is packed during coating, and if the particle size is 15 μm or less, sufficient interference light cannot be obtained. 15 μm to 50 μm
Is preferable. The number of pinholes for obtaining a particle size of 50 μm can be obtained from the above equation as 800. Also, from the above equation, a number of about 9,000 is obtained to obtain a particle size of 15 μm.

FIG. 6 shows the relationship between the number of pinholes present in the aluminum foil and the average particle size of the flakes obtained by grinding the same. In FIG. 6, the curve of the above equation is shown by a solid line, and the measured value is shown by a point. In addition,
This measured value was obtained by pulverizing under the same conditions as those shown in FIG. That is, the thickness of the aluminum foil is 0.4 μm
Ultrasonic waves are applied in acetone for 150 minutes for pulverization. As can be seen from FIG. 6, if the number of pinholes is in the range of 800 to 9000 per 1 mm ² , the average particle size of the crushed flakes is in the range of 15 μm to 50 μm.

The number of the pinholes can be controlled by the method of hitting aluminum in the process of hitting and extending aluminum when manufacturing aluminum foil.

FIG. 7 shows the results obtained by observing the flakes thus crushed with a scanning electron microscope. FIG.
As can be seen from the above, it was confirmed that the crushed flakes had the same emboss pattern as the original plate. It has been found that such flakes exhibit an optical effect of diffraction and can be used as a hologram pigment.

The flakes obtained as described above were classified by a sieve to obtain flakes having a particle size of 25 to 45 μm.
This flake was blended so as to have a component composition shown in Table 4 to make it clear.

[0040]

[Table 4] The thus-prepared clear containing the hologram pigment was applied on a color base of a coated plate by a spray gun. After the application, it was held at 140 ° C. for 20 minutes and fixed. Even after the application, each flake on the coated plate exhibited an optical effect of diffraction, and exhibited a diffraction pattern embossed on its surface. The coated plate thus obtained was able to create a unique iridescent effect.

When the metal foil 12 is pulverized, a surfactant such as oleic acid is applied and then immersed in acetone, and ultrasonic waves are applied to improve dispersibility when blended with the component compositions shown in Table 4. We were able to. The addition of this surfactant
When performed after grinding by ultrasonic waves, sedimentation of ground flakes due to gravity segregation increased. As such a surfactant, stearic acid and the like can be used in addition to oleic acid.

Embodiment 2 FIG. 9 shows an example of an apparatus for carrying out the method for producing a metal fine piece with an embossed pattern according to the present embodiment. In FIG. 9, a mold 10 having an embossed pattern is arranged above and below a metal foil 12 such as an aluminum foil to sandwich the metal foil 12. Further, a dummy plate 14 which is a tensile stress absorbing plate of the present invention is disposed above and below the mold 10 with the metal foil 12 interposed therebetween, and pressure is applied from above and below the dummy plate 14 by a rolling roll 16. Thus, the mold 10 can be pressed against both surfaces of the metal foil 12 while sequentially applying pressure to the mold 10 from the rolling roll 16 via the dummy plate 14. For this reason, the emboss pattern on the surface of the mold 10 is transferred to the metal foil 12.

As described above, the rolling roll 16 and the mold 1
The dummy plate 14 is arranged between the rolling roll 1
When pressure is directly applied to the mold 10 by the mold 6, the mold 10 is crushed and deformed by tensile stress, so that this is prevented. When the mold 10 is deformed, the emboss pattern on the surface of the mold 10 is also deformed, and its cycle is extended. Therefore, even if the emboss pattern is transferred to the metal foil 12 in this state, the interference light is weakened. However, FIG.
When the dummy plate 14 is arranged as shown in FIG.
The emboss pattern can be transferred to the metal foil 12 without deformation of the mold 10. As described above, the dummy plate 14 is only required to prevent the interference color from being deteriorated due to the deformation of the mold 10 and the extension of the period of the emboss pattern.
It is only necessary that the material be capable of absorbing the tensile stress by being dispersed over the entire back surface of the zero or by itself deforming. For example, an iron plate or a material having elasticity can be used.

As a method of applying pressure to the mold 10 by the roll 16 via the dummy plate 14, two methods (conditions A and B) shown in FIG. 10 can be considered. Condition A is that the rotation direction of the rolling roll 16 and the longitudinal direction of the groove of the embossed pattern on the surface of the mold 10 match. Condition B is that the rotation direction of the rolling roll 16 and the longitudinal direction of the groove of the embossed pattern on the surface of the mold 10 are 90 degrees.
It is the case of forming an angle of °. Among these conditions, when the mold 10 was pressed against the metal foil 12 under the condition A, the interference color of the manufactured hologram pigment became better. This is because under the condition B, the period of the emboss pattern is extended by the rolling of the rolling roll 16, and when the emboss pattern is transferred to the metal foil 12 in this state, the intensity of the interference color becomes weaker. It is considered that, under the condition A, even if the rolling is performed by the rolling roll 16, the period of the emboss pattern on the surface of the mold 10 is not extended, so that the interference color of the hologram pigment to be manufactured does not decrease.

Table 5 shows the observation results of the interference colors of the hologram pigments manufactured under the conditions A and B.

[0046]

[Table 5] As can be seen from Table 5, the interference color is stronger in the condition A than in the condition B, and an extremely favorable interference color as a hologram pigment can be obtained.

Hereinafter, a specific example in which a hologram pigment is manufactured by the method for manufacturing a metal fine piece with an embossed pattern according to the present embodiment will be described.

A 130 μm-thick nickel master having an embossed pattern was placed as a mold 10 above and below a 1 μm-thick aluminum foil as the metal foil 12, and the aluminum foil was sandwiched. It was further sandwiched by a 1 mm-thick iron plate as a dummy plate 14, and this was rolled by a rolling roll 16 shown in FIG. The dummy plate 14 is not limited to an iron plate.

The roll material of the rolling roll 16 is a bearing steel SU.
J-2, a two-high rolling mill having a diameter of 70 mm and a width of 120 mm was used. The roll peripheral speed was 1 m / min. Aluminum foil, nickel master and dummy plate 1 to be rolled
The size of the iron plate as 4 is 70 mm wide and 150 m long
m. The total thickness of the aluminum foil, nickel master plate, and iron plate superimposed on each other as shown in FIG. 9 was 2.3 mm. The rolling reduction in this case is about 30%
Becomes The weight required for this rolling was about 8 tons. The rolling was performed at room temperature, and the surface pressure was 600 MPa. When using aluminum foil as the metal foil 12, 550M at room temperature
A surface pressure of Pa or more is required. If it is less than 500 MPa, the transfer of the emboss pattern to the aluminum foil becomes insufficient. The emboss pattern was transferred to the upper and lower surfaces of the aluminum foil by the above method. In addition, what can be used as the mold 10 is not limited to the nickel original plate, but iron, tungsten, tool steel or the like can be considered.

As described above, the aluminum foil to which the embossed pattern was transferred exhibited an optical effect of diffraction, and had an embossed optical pattern on its surface.

Next, the rolled aluminum foil is placed in a mold 10
Immersed in acetone as it is, and then homogenized (ultrasonic cleaner)
To apply ultrasonic waves. When an aluminum foil having a thickness of 1 μm is ultrasonically pulverized in acetone, flakes having a particle size of 50 μm or less, which is a desirable particle size as a pigment, are obtained in 150 minutes.
A pulverized product containing 5% or more could be obtained. Observation with a scanning electron microscope and a laser microscope of the flakes obtained by pulverization confirmed that each flake had the same emboss pattern as the original. Each flake also showed the optical effect of diffraction.

The flakes (hologram pigment) prepared as described above are classified by sieving to obtain a particle size of 25 to 45 μm.
m flakes were obtained. 0.03 g of this flake, 150 cc of an acrylic melamine resin, and 50 cc of a thinner were mixed to obtain a clear mixture. In this way, the clear containing the hologram pigment was applied on the color base of the coating plate by the spray gun. After the application, the coating was maintained at 140 ° C. for 20 minutes to fix the coating containing the hologram pigment.

Even after the coating, each flake on the coated plate exhibited a diffraction optical effect, and exhibited a diffraction pattern having an embossed pattern formed on the surface thereof. The coated plate thus obtained was able to create a unique iridescent effect.

[0054]

As described above, according to the present invention,
Since the emboss pattern is transferred directly to the metal foil by the mold, the transferability of the emboss pattern to the metal foil is good, and the productivity can be improved because the manufacturing process is simple.

Further, since the metal foil is crushed by immersing it in a liquid with the metal foil attached to the mold and applying ultrasonic waves thereto, peeling and crushing of the metal foil from the mold are performed simultaneously. This also simplifies the manufacturing process.

Also, by increasing the surface tension of the liquid used at the time of pulverization, the wettability to the metal foil can be improved, and the influence of the adhered substance such as oil on the pulverization can be removed, and the particles can be refined. Can be made possible.

Further, by pre-cooling the metal foil at the time of pulverization, the undulation of the pulverized flakes can be reduced, and the interference light can be enhanced.

Further, by lowering the surface energy of the mold or the metal foil, it is possible to suppress the disturbance of the surface when the metal foil is released from the mold, and thereby it is possible to enhance the interference light.

Further, by controlling the number of pinholes present in the metal foil, the particle size of the crushed flakes can be controlled.

Further, by applying a surfactant to the metal foil and then pulverizing it, the dispersibility of the pulverized flakes in the case of a hologram pigment can be improved, thereby suppressing sedimentation due to gravity segregation.

Further, by using a rolling roll,
Higher weight can be efficiently applied to the upper and lower surfaces of the metal foil.

Further, by making the rotation direction of the rolling roll coincide with the longitudinal direction of the embossed pattern of the mold, the period of the embossed pattern on the surface of the mold can be prevented from being extended by rolling, and the embossed pattern transferred to the metal foil can be prevented. The interference color of the pattern can be kept high.

Further, since the tensile stress absorbing plate is disposed between the rolling roll and the mold, it is possible to suppress the application of a tensile force to the mold, thereby maintaining a high interference color of the embossed pattern transferred to the metal foil. can do.

[Brief description of the drawings]

FIG. 1 is a view showing the steps of Embodiment 1 of the method for producing a metal fine piece with an embossed pattern according to the present invention.

FIG. 2 is a diagram showing the relationship between the grinding time of metal foil by ultrasonic waves and the particle size after grinding.

FIG. 3 is a diagram showing the relationship between the thickness of an aluminum foil used as a metal foil and the average particle size of flakes after pulverization.

FIG. 4 is a diagram showing the relationship between the surface tension of a liquid used for pulverization and the average particle size of flakes after pulverization.

FIG. 5 is an explanatory diagram showing a state of a pinhole existing in an aluminum foil.

FIG. 6 is a diagram showing the relationship between the amount of pinholes present in an aluminum foil and the average particle size of flakes after pulverization.

FIG. 7 is an electron micrograph of a flake after crushing.

FIG. 8 is a view showing a conventional method for producing a metal flake pigment with an embossed pattern.

FIG. 9 is an explanatory view of an apparatus for carrying out Embodiment 2 of the method for producing a metal fine piece with an embossed pattern according to the present invention.

FIG. 10 is an explanatory view showing a relationship between a rotation direction of a rolling roll and a longitudinal direction of an embossed pattern of a mold in the method for manufacturing a metal fine piece with an embossed pattern shown in FIG. 9;

[Explanation of symbols]

10 type, 12 metal foil, 14 dummy plate, 16 roll, 50 carrier sheet, 52 release coating, 54 applicator.

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Yukio Okochi 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation (72) Inventor Masaji Nakanishi 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation (72) Inventor Hidekazu Yamanakajima 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation

Claims (10)

[Claims] 1. A method for producing a fine metal piece with an embossed pattern, comprising forming an embossed pattern on the surface of the metal foil by pressing a mold having an embossed pattern on both sides of the metal foil. 2. The method for producing a metal fine piece with an embossed pattern according to claim 1, wherein the metal foil pressed to have a thickness of less than 2 μm is dipped in a liquid while being adhered to the mold. A method for producing a metal fine piece with an embossed pattern, wherein the fine piece having an embossed pattern is pulverized into a thin piece having a size of less than 50 μm simultaneously with release from the mold by applying ultrasonic waves. 3. The method according to claim 2, wherein the liquid has a surface tension of 0.0.
A method for producing a metal fine piece with an embossed pattern, which is less than 4 N / m. 4. The method for producing a metal fine piece with an embossed pattern according to any one of claims 1 to 3,
A method for producing metal fine pieces with an embossed pattern, characterized in that the metal foil is precooled to -50C or lower before pulverization. 5. The method for producing a metal fine piece with an embossed pattern according to any one of claims 1 to 4,
A method of producing a metal fine piece with an embossed pattern, wherein at least one of the metal foil and the mold is reduced in surface energy when the mold is pressed against the metal foil. 6. The method for producing a metal fine piece with an embossed pattern according to any one of claims 1 to 5,
The metal foil has a pinhole having a diameter of 10 nm or less of 1 mm.
^2. A method for producing embossed-patterned metal fine pieces, wherein the metal pieces are present at a density of 800 or more and 9000 or less in the area of No. ² . 7. The method for producing fine metal pieces with an embossed pattern according to claim 1, wherein a surfactant is applied to the metal foil against which the mold has been pressed, then the metal foil is immersed in a liquid, and ultrasonic waves are applied to pulverize the metal foil. A method for producing fine metal pieces with an embossed pattern. 8. The method according to claim 1, wherein the die is pressed against both surfaces of the metal foil while sequentially applying pressure to the die by a rolling roll. A method for producing a patterned metal fine piece. 9. The method for producing a metal fine piece with an embossed pattern according to claim 8, wherein a rotation direction of the rolling roll coincides with a longitudinal direction of the embossed pattern of the mold. A method for producing metal fine pieces. 10. The method for producing a metal fine piece with an embossed pattern according to claim 8, wherein a tensile stress absorbing plate is disposed between the rolling roll and the mold. A method for producing a patterned metal fine piece.