JP4588607B2 - Sheet transfer device - Google Patents

Description

The present invention relates to a sheet transfer apparatus that easily performs rolling for transferring a micron-order uneven pattern such as a hologram to a sheet surface continuously and uniformly.

  It is known that surface functions such as water repellency, lubricity or design are improved by forming a fine uneven pattern on the metal surface. In recent years, hologram sheets and the like whose function has been improved by making these concavo-convex patterns on the order of microns have been manufactured, and are easily available as commercial products.

  Usually, when transferring a fine concavo-convex pattern to a sheet, the concavo-convex shape is processed directly on the surface of the transfer roll, or a mold having a concavo-convex shape is attached to the transfer roll surface, A transfer process for obtaining a transfer sheet on which a concavo-convex pattern opposite to the concavo-convex pattern of the mold is formed by supplying and rolling the transfer target sheet is performed.

  As a conventional example of processing the concave / convex pattern directly on the transfer roll surface like the former, the steel roll surface has a rough surface electrolyzed in an electrolytic solution using this roll as an anode, and a chromium plating layer thereon There is a roll for embossing an aluminum plate (see Patent Document 1).

  In the latter case, when a mold having a concavo-convex shape is attached to the surface of a transfer roll and transferred to a transfer sheet, as a conventional method of forming the mold having the concavo-convex shape, the forming process is shown in FIG. There is an aluminum foil having a hologram relief pattern shown in a sectional view and a manufacturing method thereof (see Patent Document 2).

  According to the relief pattern forming method according to this conventional example, a photoresist layer 12 is formed on a metal foil 11 such as Ni or stainless steel, and then a hologram relief pattern is baked and developed as shown in FIG. Then, the strongly exposed resist layer 12 is removed. Further, as shown in (c), when etching pits 13 are formed in a portion without the resist layer 12 by etching, and the resist layer 12 is removed as shown in (d), irregularities corresponding to the hologram relief pattern are formed. Is formed on the surface of the metal foil 11.

Then, the obtained metal foil 11 is wound around a rolling roll and set, and the uneven pattern of the metal foil 11 is transferred to an aluminum foil by a rolling mill to form a hologram relief pattern.
JP 2005-146299 A Japanese Patent No. 2969004

However, according to the conventional transfer method as described above, the uneven shape is directly processed on the surface of the transfer roll, or the die having the uneven shape is attached to the surface of the work roll and rolled.
When the rolling surface pressure is backed up from the back surface of the work roll by the backup roll, the concavo-convex pattern is crushed by the surface pressure of the backup roll.

In addition, according to the conventional transfer apparatus that transfers the uneven pattern with a two-stage rolling mill with only a work roll without the backup roll, there is a limit to the rolling surface pressure control, and in particular, the width is uniform and the quality is stable. There was a problem that it was difficult to obtain an uneven pattern. Furthermore, when transferring microscopic irregularities in micron order, the transfer pattern becomes unclear over time due to clogging of the irregularity pattern on the work roll surface due to wear powder generated during rolling. Also had.

Accordingly, an object of the present invention is to provide a sheet transfer apparatus that can stably transfer a micron-order fine concavo-convex pattern formed on a mold continuously to a transfer sheet and obtain a uniform and high-quality transfer sheet. There is to do.

In order to achieve the above object, the means employed by the sheet transfer apparatus according to claim 1 of the present invention is a mold in which the surface of a metal sheet having a thickness of 5 μm to 3 mm is processed to be uneven and formed into a coil shape or a hoop shape. At least on the rolling exit side of the sheet, a tension applying means for applying a rolling tension to the mold sheet is provided, and the transfer sheet is continuously rolled on the mold sheet by an overlapping rolling machine, thereby the surface of the mold sheet. the uneven pattern formed on it characterized in that without an arrangement for continuously transferred to the transfer sheet.

The means employed by the sheet transfer apparatus according to claim 2 of the present invention is the sheet transfer apparatus according to claim 1 , wherein the mold sheet is washed at least on the rolling exit side or rolling entrance side of the mold sheet. The present invention is characterized in that a cleaning means is provided .

According to the sheet transfer apparatus of the first aspect of the present invention, the metal sheet having a thickness of 5 μm to 3 mm is subjected to uneven processing, and at least on the rolling exit side of the mold sheet formed into a coil shape or a hoop shape. A tension applying means for applying a rolling tension to the mold sheet is provided, and the uneven sheet formed on the surface of the mold sheet is transferred to the mold sheet by continuously rolling the transfer sheet on the mold sheet with a rolling mill. In this configuration , continuous transfer is performed .

  As a result, even if the backup roll is backed up from the back of the work roll, the backup roll does not contact the mold sheet. Therefore, the conventional essential problem that the backup roll cannot be used or the uneven pattern of the mold is crushed by the backup roll surface pressure is solved.

Moreover, at least in the rolling exit side of the mold sheet, continuously together when providing a tensioning means for imparting a rolling tension into the mold sheet, the uneven pattern formed on the mold surface of the sheet to the receiver sheet Therefore, it is possible to prevent the mold itself from being damaged and the transfer pattern spots from being generated due to wrinkles generated in the mold sheet.

Further, according to the sheet transfer apparatus according to claim 2 of the present invention, since the mold sheet is provided with a cleaning means for cleaning the mold sheet at least on the rolling exit side or the rolling entrance side, It is possible to provide a sheet transfer apparatus capable of obtaining a high-quality transfer sheet without clogging the concavo-convex pattern due to wear powder or coating adhering to the mold sheet surface.

First, the sheet transfer apparatus according to the first embodiment of the present invention will be described below with reference to FIG. 1 which is a configuration diagram schematically showing a cross section.
In the first embodiment, an example is shown in which a sheet transfer apparatus 10 is formed by applying the present invention to an ordinary four-high rolling mill 8 for a mold sheet 1 having an endless hoop shape.

  The four-stage rolling mill 8 is fed from the hoop-shaped mold sheet 1 that runs endlessly in the direction of the arrow and the transferred sheet decoiler 6a, runs in the direction of the arrow, and is wound around the transferred sheet coiler 6b. The transferred sheet 2 to be taken is overlapped, nipped by a pair of work rolls 3, and the transfer pressure is backed up by a pair of backup rolls 4 from the back of the work roll 3, while the unevenness of the mold sheet 1 is made. The pattern is transferred to the transfer sheet 2.

  The hoop-shaped mold sheet 1 requires strength as a mold and is bent into a hoop shape as shown in FIG. 1 or wound into a coil shape as shown in FIG. A thickness in the range of about is required. Generally, when the thickness of the mold sheet 1 is less than 5 μm, the uneven pattern is easily damaged due to insufficient strength or the sheet is easily broken. When the thickness exceeds 3 mm, the mold sheet 1 is elastically deformed. This is because it tends to cause fatigue fracture due to repeated bending.

  Moreover, the metal used for such a metal mold | die sheet | seat 1 naturally requires the metal material whose hardness is higher than a to-be-transferred sheet from a durable point. That is, a metal material that is excellent in strength and alkali resistance, such as an aluminum alloy having a hardness of Hv 100 or higher, SUS304, or Ni, and that can withstand a bent shape in a hoop shape or a coil shape, is preferable.

  On the other hand, the material of the transferred sheet 2 is not particularly limited as long as it is a metal or resin having a lower hardness than the material of the mold sheet 1, but aluminum, aluminum alloy, copper, copper alloy, or the like is preferable. Furthermore, although a plated steel plate, stainless steel, titanium, etc. are preferable, the thing of the material whose hardness is higher than this is not preferable from the point of the abrasion of the metal mold | die sheet 1.

  The mold sheet 1 having a concavo-convex pattern processed on such a surface can obtain an arbitrary fine concavo-convex pattern by electroforming a metal sheet. The electroforming is a processing method in which a thick plating is applied to the surface of a mother die, and this is peeled off from the mother die to obtain a shape pattern completely opposite to the mother die.

  The principle of electroforming is to deposit the target metal on the object to be plated through an electric current in an electrolyte solution containing electric ions using the same electrochemical reaction as that of electroplating. By such a method, it is possible to continuously perform electroplating using a long mother mold and peel it from the mother mold to produce a mold sheet.

Alternatively, a commercially available wire mesh sheet woven with stainless steel (for example, SUS304) fine wires can be used as the mold sheet 1.
Such a mold sheet 1 is required to be a metal material having high hardness regardless of its form, and preferably has a surface hardness Hv of at least 100 or more.

  An uneven pattern formed on the surface of the mold sheet 1 is obtained by superimposing the transfer sheet 2 on the mold sheet 1 manufactured in this way and continuously rolling the sheet by running it in the direction of the arrow with a four-stage rolling mill 8. Is continuously transferred to the transfer sheet 2.

  On the other hand, when the mold sheet 1 is repeatedly continuously transferred by the rolling mill 8, local plastic deformation occurs at the end of the mold sheet and wrinkles are generated. And the fracture | rupture of the metal mold | die 1 based on this wrinkle comes to generate | occur | produce frequently. Further, such wrinkles generated on the mold sheet 1 cause transfer pattern spots.

  Therefore, in the sheet transfer apparatus 9 according to the present invention, the tension applying means 5a and 5b for applying the rolling tension to the mold sheet 1 are transferred into and out of the rolling mill 8 (before and after the work roll 3 of the mold sheet 1). ) To suppress the generation of wrinkles. Further, the tension applying means is not necessarily provided for rolling in / out of the rolling mill 8, and at least the tension applying means 5b on the rolling exit side (after the work roll 3 of the mold sheet 1) may be provided.

  As the tension applying means, it is preferable to provide two sets of bridal rolls 5a and 5b as shown in FIG. 1 at the rolling in / out of the rolling mill 8 (before and after the work roll 3 of the mold sheet 1). The bridal rolls 5a and 5b are usually composed of two or four rolls, respectively, and the roll surface is generally hard rubber-lined.

  The mold sheet 1 is wound around the two sets of bridal rolls 5a and 5b, and the rotational speed of each of the bridal rolls 5a and 5b is controlled to generate tension between the bridal rolls 5a and 5b. The tension can be reduced behind the bridal rolls 5a and 5b.

  The mold sheet 1 that has undergone such a rolling process adheres to wear powder generated during rolling, or is soft when the transfer sheet 2 is made of aluminum, copper, or an alloy thereof. Adheres to form a very thin layer called a coating. When the abrasion powder or coating is generated, the uneven pattern formed on the surface of the mold sheet 1 is clogged, and it becomes impossible to transfer the pattern accurately.

  Therefore, the sheet transfer apparatus 8 according to the present invention preferably includes a cleaning unit 7 for cleaning the mold sheet 1 after the transfer. The inside of the cleaning means 7 is constituted by a cleaning tank, a rinsing tank and a drying unit (not shown), and the mold sheet 1 introduced at a low tension is first passed through the cleaning tank and cleaned with a cleaning liquid, Next, the cleaning liquid is removed by rinsing water through a rinsing tank, and then dried by heating in a drying section.

  As the cleaning liquid used in the cleaning tank, an alkaline solution such as sodium hydroxide or sodium hypochlorite can be used. With such an alkaline solution, the abrasion powder and coating adhering to the mold sheet 1 are dissolved and removed.

  Further, the sheet transfer apparatus 10 according to the present invention has four or more stages of rolling, that is, a pair of backup rolls, each composed of a pair of work rolls 3 and a pair of back-up rolls 4 as shown in FIG. What consists of the above logarithm is preferable.

The sheet transfer apparatus 10 according to the present invention uses a sheet-shaped mold without using the work roll 3 as a mold, so that the surface pressure of the work roll 3 is kept high by using the backup roll 4 and has a width. The roll surface pressure in the direction can be made uniform. Furthermore, since the backup roll 4 does not come into contact with the mold sheet 1, there is no fear that the uneven pattern of the mold sheet 1 will be crushed. Therefore, as described above, it is preferable to apply a multi-high rolling mill having four or more stages.

  The reason why the surface pressure of the work roll 3 can be kept high when the backup roll 4 is used will be described below. That is, in the two-high rolling mill without the backup roll 3, if the surface pressure of the work roll 3 is increased to obtain a uniform transfer pattern in the width direction, it can withstand the reaction force against the roll 3 surface pressure. It is necessary to increase the diameter of the work roll 3 to some extent.

  However, when the diameter of the roll 3 is increased, the contact area between the mold sheet 1 and the transfer sheet 2 increases, so that it is necessary to increase the rolling load to obtain the required roll surface pressure. In order to suppress this, a large surface pressure cannot be applied.

  However, in the multi-stage rolling mill with the backup roll 4 attached, the diameter of the work roll 3 can be reduced. If a small-diameter roll can be used, the contact area becomes small even with the same rolling load, so that the roll surface pressure can be increased. As a result, a uniform transfer pattern can be obtained in the width direction.

  Furthermore, in such a multi-stage rolling mill, using a roll surface pressure control means (not shown) that maintains a constant roll surface pressure loaded in the width direction of the mold sheet 1 and the transfer sheet 2, It is preferable to continuously transfer the uneven pattern formed on the surface of the mold sheet 1 to the transfer sheet 2 in order to obtain a more uniform transfer pattern in the width direction.

  In the roll surface pressure control means, hydraulic cylinders are attached to both shaft ends of the work roll 3 and the backup roll 4, and the hydraulic cylinder is expanded and contracted, and the “rolling lever” is used as a fulcrum during rolling. There is a shape control actuator that bends the work roll 3 and the backup roll 4 bent by the surface pressure in the opposite direction and corrects the surface pressure to be uniform in the width direction.

  As another example of the roll surface pressure control means, a crown-shaped backup roll having a mechanism capable of shifting the roll axis in a predetermined range in the axial direction is disposed on the back surface of the work roll 3, and the surface being rolled. A roll that supports the work roll 3 bent by pressure from the back, shifts the crown position of the backup roll to a position where the surface pressure in the roll width direction is low, and corrects the surface pressure to be uniform in the width direction. A shift mechanism can be applied.

Next, a sheet transfer apparatus according to Embodiment 2 of the present invention will be described below with reference to FIG. 2, which is a configuration diagram shown in a schematic cross section.
The second embodiment of the present invention differs from the first embodiment in that the mold sheet 1 is coilable and the bridal rolls 5a and 5b of the first embodiment. Since there is a difference in the parts that are not attached and the other parts have the same configuration, the same reference numerals are given to the same components as those in the first embodiment, and the differences will be described below.

That is, in the sheet transfer apparatus 10 according to the second embodiment of the present invention, the coil-shaped mold sheet 1 is unwound from the mold sheet decoiler 9a, and the transfer sheet 2 is provided with a concavo-convex pattern by the rolling apparatus 8. After being transferred, the sheet is wound around the mold sheet coiler 9b through the cleaning means 7.

  In Embodiment 2 of the present invention, the tension applying means of the mold sheet 1 is composed of at least a rotation control mechanism provided in the mold sheet decoiler 9a. Moreover, this rotation control mechanism can also be provided in the sheet coiler 9b, and tension can be applied by both.

  Thus, when the form of the mold sheet 1 is coiled, the mold sheet 1 and the transfer sheet 2 are required to have the same length. However, the mold sheet 1 is about 1/10 of the length of the transferred sheet 2, and when the mold sheet 1 finishes transferring to the transferred sheet 2, the travel of both the sheets 1 and 2 is stopped. Then, the coil wound around the mold sheet coiler 9b is transferred to the mold sheet decoiler 9a, and the starting end of the mold sheet 1 is reattached to the traveling path and continuously transferred again.

  By repeating such an operation a plurality of times, a transfer sheet 2 that is much longer than the mold sheet 1 can be produced. 2 shows the example in which the cleaning means 7 for the mold sheet 1 is provided in the post-process after the transfer to the transfer sheet 2 is completed, but it is provided in the pre-process for transferring to the transfer sheet. May be.

As described above, according to the sheet transfer apparatus according to the present invention, since the mold is formed on a coil-like or hoop-like long sheet, even if the backup roll backs up from the back of the work roll, the unevenness of the mold is caused by the surface pressure. The conventional essential problem that the pattern is crushed is solved.

  In addition, the sheet transfer apparatus according to the present invention can prevent occurrence of breakage of the mold and transfer pattern spots due to wrinkles generated in the mold sheet by providing tension applying means for applying tension to the mold sheet. A sheet transfer apparatus can be provided. Further, by providing a cleaning means for cleaning the mold sheet, the attached abrasion powder and coating can be removed, and a sheet transfer apparatus that does not clog the uneven pattern of the mold sheet can be obtained.

Furthermore, according to the sheet transfer apparatus of the present invention, the transfer of the mold sheet that has been transferred and wound up on the mold sheet coiler to the mold sheet decoiler is repeated by repeating continuous transfer again. A long transfer sheet can be produced from a short mold sheet.
<Example>

Next, an example in which a metal mesh sheet woven with SUS304 extra fine wire (φ18 μm) was used as a mold sheet by the sheet transfer apparatus according to the present invention and was produced under the following trial conditions will be described.

Trial production conditions : Rolling mill: 150 mm wide small four-high rolling mill Transfer sheet: Pure aluminum sheet with a thickness of 1 mm and a width of 50 mm Workpiece diameter: φ100 mm
・ Rolling ratio: 10%
Transfer speed: 10 m / min.

  FIG. 3 shows a drawing-substituting photograph in which the transfer surface of the transfer sheet obtained in the above example is enlarged. It can be clearly seen that the pattern of the wire mesh element wire (convex portion) of the wire mesh sheet used as the mold sheet is transferred as a groove portion having a pitch of about 60 μm on the transfer sheet side.

As described above, according to the sheet transfer apparatus according to the present invention, the transfer surface pressure can be backed up by the backup roll by using the mold formed in a sheet shape. A high-quality transfer sheet having an uneven pattern can be obtained. Such a transfer sheet can be applied to uses such as a sheet excellent in irregular reflection on the surface, a sheet having super water repellency and super hydrophilicity, and a sheet excellent in lubricity during press molding.

It is the block diagram shown with the typical cross section about the sheet transfer apparatus which concerns on Embodiment 1 of this invention. It is the block diagram shown with the typical cross section about the sheet transfer apparatus which concerns on Embodiment 2 of this invention. It is the drawing substitute photograph which expanded the transfer surface of the transfer sheet obtained in the Example. It is sectional drawing which shows the process which concerns on the prior art example which forms a hologram relief pattern on metal foil.

1 ... mold sheet, 2 ... transferred sheet,
3 ... work roll, 4 ... backup roll,
5a, 5b ... Bridal roll,
6a ... transferred sheet decoiler, 6b ... transferred sheet coiler,
7 ... cleaning means, 8 ... rolling mill,
9a ... Mold sheet decoiler, 9b ... Mold sheet coiler,
10. Sheet transfer device

Claims (2)

At least on the rolling exit side of a mold sheet formed into a coil shape or a hoop shape by processing the surface of a metal sheet having a thickness of 5 μm to 3 mm, a tension applying means for applying a rolling tension to the mold sheet is provided. The transfer sheet is continuously rolled onto the mold sheet by a rolling mill, and the uneven pattern formed on the surface of the mold sheet is continuously transferred to the transfer sheet. Sheet transfer device. 2. The sheet transfer apparatus according to claim 1 , wherein a cleaning means for cleaning the mold sheet is provided at least on the rolling exit side or the rolling entrance side of the mold sheet.

Images