WO2019188797A1

WO2019188797A1 - Method for manufacturing mold having recessed seat pattern, and method for producing pattern sheet

Info

Publication number: WO2019188797A1
Application number: PCT/JP2019/012123
Authority: WO
Inventors: 聡茶井; 宇佐　利裕
Original assignee: 富士フイルム株式会社
Priority date: 2018-03-27
Filing date: 2019-03-22
Publication date: 2019-10-03

Abstract

Provided are a method for manufacturing a mold having a recessed seat pattern to prevent the flow of a liquid, and a method for producing a pattern sheet. The method for manufacturing a mold having a recessed seat pattern has a step for preparing a nested mold having a first convex seat shape having a recess on the reverse surface and a second convex needle pattern group on the surface of the first convex seat shape, a step for preparing a mold having a first mold and a second mold, a reinforcement step for providing a support layer in the recess on the reverse surface of the first convex seat shape provided in the nested mold, a mold clamping step for clamping the nested mold by the first mold and the second mold to form a cavity, and an injection step for filling the cavity with a molding resin.

Description

Method for producing mold having concave pedestal pattern and method for producing pattern sheet

The present invention relates to a method for producing a mold having a concave pedestal pattern and a method for producing a pattern sheet, and in particular, a method for producing a mold having a concave pedestal pattern used for producing a pattern sheet having needle-like convex portions and the concave pedestal. The present invention relates to a method for producing a pattern sheet using a mold having a pattern.

In recent years, Micro-Needle® Array has been known as a new dosage form that can administer drugs such as insulin, vaccine (Vaccines) and hGH (human Growth Hormone) into the skin without pain. ing. The microneedle array is an array of biodegradable microneedles (also referred to as needle-like convex portions, microneedles, or microneedles) containing a drug and arranged in an array. By affixing this microneedle array to the skin, each microneedle pierces the skin, the microneedle is absorbed in the skin, and the drug contained in each microneedle can be administered into the skin. The microneedle array is also called a transdermal absorption sheet.

In order to produce a molded product having a fine pattern such as a microneedle array, a resin-inverted mold is formed from an original plate having a fine pattern, and a molded product is produced from this mold. . There is a demand for improving the productivity of molded products having such fine patterns, and various proposals have been made.

For example, Patent Documents 1 and 2 describe a technique for producing a mold by injection molding in which an electroformed mold is sandwiched between a first mold and a second mold and a resin is filled in a cavity. According to Patent Documents 1 and 2, an accurate mold can be produced.

JP 2017-209155 A JP 2017-202040 A Japanese Patent Laying-Open No. 2015-231476

On the other hand, in Patent Document 3, when forming a pattern sheet, a step is provided in order to prevent the resin solution constituting the pattern sheet from flowing out of the mold and flowing beyond a target location. The type is described. By using a mold having a step, it is possible to prevent the liquid containing no drug from flowing out of the mold and flowing when a liquid containing no drug is applied to the mold surface.

However, Patent Document 3 does not disclose a configuration in which a mold configured to prevent liquid flow is manufactured by injection molding.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a method for producing a mold having a concave pedestal pattern and a method for producing a pattern sheet, which prevent the liquid from flowing.

In order to achieve the above object, one aspect of a method for producing a mold having a concave pedestal pattern includes a first convex pedestal shape having a concave portion on the back surface and a second convex needle pattern group on the first convex pedestal surface. Providing a support layer in a recess on the back surface of the first convex pedestal shape provided in the nesting mold, and a step of preparing a mold having the first mold and the second mold. A mold having a concave pedestal pattern having a reinforcing step, a mold clamping step of clamping a nested die by a first die and a second die to form a cavity, and an injection step of filling the cavity with a mold resin This is a manufacturing method.

According to this aspect, since the support layer is provided in the concave portion on the back surface of the first convex pedestal shape provided in the nesting mold, it is possible to produce a mold having a concave pedestal pattern following the first convex pedestal shape. it can.

The support layer is preferably composed of at least one of a support resin, a metal, and a liquid. Thereby, a 1st convex base shape can be reinforced appropriately.

The support layer preferably includes at least one of a support resin and a metal, and has a smoothing step of polishing and smoothing at least one of the support resin and the metal. Thereby, a support layer can be provided appropriately.

Polishing preferably uses at least one of grinding, superfinishing, honing, blasting, ultrasonic processing, lapping, and polishing. Thereby, the back surface of a support layer can be smoothed appropriately.

The support layer preferably contains a fluid, and the first type preferably has a fluid flow path. Thereby, a support layer can be comprised with a fluid.

The mold resin is preferably either a thermosetting resin or a silicone resin. Thereby, a mold can be produced appropriately.

After the injection process, the mold resin in the cavity is cured by heating, and after the curing process, the first mold and the second mold are opened, and the cured mold resin is released from the nesting mold. A mold release step. Thereby, a mold can be produced appropriately.

The nesting mold is preferably either a plastic resin or a metal. Thereby, a mold can be produced appropriately.

The nesting die is an electroforming die and is preferably circular in plan view. Thereby, a nested mold | type can be produced appropriately.

In order to achieve the above object, one aspect of a method for producing a pattern sheet includes a step of producing a mold having a concave pedestal pattern by a method for producing a mold having a concave pedestal pattern, and a polymer solution in the concave pedestal pattern of the mold. It is the manufacturing method of the pattern sheet | seat including the supply process to supply, the drying process which dries a polymer solution, and makes a polymer sheet, and the polymer sheet mold release process which releases a polymer sheet from a mold.

According to this aspect, since the polymer solution does not overflow from the concave pedestal pattern, the pattern sheet can be manufactured appropriately.

It is preferable that the polymer solution contains a water-soluble material. This embodiment can be applied to a polymer solution containing a water-soluble material.

According to the present invention, a mold configured to prevent liquid flow can be produced by injection molding. Moreover, a pattern sheet can be manufactured with this mold.

It is process drawing which shows the preparation methods of an electroforming metal mold | die. It is process drawing which shows the preparation methods of an electroforming metal mold | die. It is process drawing which shows the preparation methods of an electroforming metal mold | die. It is process drawing which shows the preparation methods of an electroforming metal mold | die. It is a perspective view of an electroforming mold. It is process drawing which shows the preparation methods of a mold. It is process drawing which shows the preparation methods of a mold. It is process drawing which shows the preparation methods of a mold. It is process drawing which shows the preparation methods of a mold. It is process drawing which shows the preparation methods of a mold. It is process drawing which shows the preparation methods of a mold. It is process drawing which shows the preparation methods of a mold. It is process drawing which shows the preparation methods of a mold. It is process drawing which shows the preparation methods of a mold. It is process drawing which shows the production method of another mold. It is process drawing which shows the production method of another mold. It is a figure which shows the cross-sectional shape of a nest type | mold and a mold. It is a figure which shows the creation process of a reinforcement member. It is a figure which shows a reinforcement member. It is a figure which shows the cross-sectional shape of the concave base pattern of a mold. It is a figure which shows the reinforcement member using a metal plate. It is a figure which shows the cross-sectional shape of the convex base shape of a mold. It is a figure which shows a mold clamping process. It is a figure which shows a reinforcement process. It is process drawing which shows the manufacturing method of a pattern sheet. It is process drawing which shows the manufacturing method of a pattern sheet. It is process drawing which shows the manufacturing method of a pattern sheet. It is process drawing which shows the manufacturing method of a pattern sheet. It is a perspective view of a pattern sheet. It is process drawing which shows the procedure of the manufacturing method of the electroforming metal mold | die which uses a mold. It is process drawing which shows the procedure of the manufacturing method of the electroforming metal mold | die which uses a mold. It is process drawing which shows the procedure of the manufacturing method of the electroforming metal mold | die which uses a mold.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. The invention is illustrated by the following preferred embodiments. Changes can be made by many techniques without departing from the scope of the present invention, and other embodiments than the present embodiment can be utilized. Accordingly, all modifications within the scope of the present invention are included in the claims.

Here, parts indicated by the same symbols in the figure are similar elements having similar functions. In addition, in this specification, when the numerical range is expressed using “˜”, the upper and lower numerical values indicated by “˜” are also included in the numerical range.

<Mold production method>
Embodiments of the present invention will be described with reference to the drawings. The method for producing a mold having a concave pattern according to this embodiment prepares a first convex pedestal shape having a recess on the back surface and a nested mold having a second convex needle pattern group on the surface of the first convex pedestal shape. A step of preparing a mold having a first mold and a second mold, a reinforcing process of providing a support layer in a concave portion on the back surface of the first convex pedestal shape provided in the nested mold, and forming a cavity For this reason, it includes a mold clamping process in which the nested mold is clamped by the first mold and the second mold, and an injection process in which the cavity is filled with resin.

Prepare a nested mold to be used for mold production. The nested type is created based on, for example, the process diagrams shown in FIGS. As shown in FIG. 1, a mother mold 10 for preparing an electroforming mold that is a nested mold is prepared. On the first surface 12 of the mother die 10, a concave pattern 14 is formed that is an inverted shape of an electroforming mold having a convex pattern to be produced. The concave pattern 14 is a state in which a plurality of second concave portions 16 are arranged in an array in the first concave portion 15. The 1st recessed part 15 and the 2nd recessed part 16 are produced according to the shape of the electroforming metal mold to produce. In the present embodiment, the first recess 15 has a cylindrical shape having a certain diameter from the first surface 12 toward the second surface 18. Further, the second recess 16 has a tapered shape from the first surface 12 toward the second surface 18. For example, examples of the tapered shape include a cone shape, a combination of a column shape and a cone shape, and a combination of a frustum shape and a cone shape. In the present embodiment, a plurality of concave patterns 14 are formed on the first surface 12 of the mother die 10.

As shown in FIG. 2, the mother die 10 is fixed to the cathode 20 used for the electroforming process. The cathode 20 includes at least a shaft 22 and a cathode plate 24. The mother die 10 is fixed to the cathode plate 24 at a position where the second surface 18 of the mother die 10 and the cathode plate 24 face each other.

When the mother die 10 is made of a resin material, a conductive treatment is performed on the mother die 10. A metal film (for example, nickel) is formed on the first surface 12 and the concave pattern 14 of the mother die 10 by vapor deposition or sputtering. In order to supply current from the cathode plate 24 to a metal film (not shown), a conductive ring 26 is provided on the outer periphery of the mother die 10. The shaft 22 and the cathode plate 24 are made of a conductive member. Here, electroforming treatment refers to a treatment method in which a metal is deposited on the surface of the mother die 10 by electroplating.

As shown in FIG. 3, the mother die 10 attached to the cathode 20 is immersed in the electroforming liquid 32. As shown in FIG. 3, an electroforming apparatus 30 that performs an electroforming process on the mother die 10 includes an electroforming tank 34 that holds an electroforming liquid 32, and an electroforming liquid 32 </ b> A that overflows the electroforming tank 34. A drain tank 36 to be received and a titanium case 40 filled with Ni pellets 38 are provided. The cathode 20 with the mother die 10 attached is functioned as an electroforming apparatus 30 by immersing it in the electroforming liquid 32. As the electroforming liquid 32, for example, a liquid in which 400 to 800 g / L nickel sulfamate, 20 to 50 g / L boric acid, and a necessary additive such as a surfactant (for example, sodium lauryl sulfate) are mixed. Can be used. The temperature of the electroforming liquid 32 is preferably 40 to 60 ° C.

A drain pipe 42 is connected to the drain tank 36, and a supply pipe 44 is connected to the electroforming tank 34. The electroforming liquid 32 overflowed from the electroforming tank 34 to the drain tank 36 is recovered by the drain pipe 42, and the recovered electroforming liquid 32 is supplied from the supply pipe 44 to the electroforming tank 34. The mother die 10 held by the cathode 20 is aligned at a position where the first surface 12 on which the concave pattern 14 is formed faces the titanium case 40 serving as the anode.

The cathode 20 is connected to the negative electrode, and the positive electrode is connected to the titanium case 40 serving as the anode. A DC voltage is applied between the cathode 20 and the titanium case 40 while rotating the mother die 10 held by the cathode plate 24 around the shaft 22 at a rotation speed of 10 to 150 rpm. The Ni pellets 38 are dissolved, and a metal film adheres to the concave pattern 14 of the mother die 10 attached to the cathode 20.

When the electroforming mold 50 composed of a metal film is formed on the mother die 10, the cathode 20 to which the mother die 10 is attached is taken out from the electroforming tank 34 (not shown) as shown in FIG. Next, the electroforming mold 50 is peeled from the mother mold 10. The electroforming mold 50 having the first surface 52 and the second surface 58 and having the flat portion 53 and the convex pattern 54 on the first surface 52 can be obtained. The convex pattern 54 is an inverted shape of the concave pattern 14 of the mother die 10. Here, the electroforming mold 50 has a thickness of 150 μm.

FIG. 5 is a perspective view of the electroforming mold 50. As shown in FIG. 5, the convex pattern 54 is a state in which a plurality of second convex portions 56 that are convex needle pattern groups are arranged in an array on the first convex portion 55 that is a convex pedestal shape. . In the present embodiment, the first convex portion 55 has a cylindrical pedestal shape having a certain height. The height of the 1st convex part 55 is the range of 0.2 mm or more and 2 mm or less, for example, Preferably, it is 0.3 mm or more and 1.5 mm or less. A cylindrical concave portion 57 having a certain diameter is provided on the back surface side of the first convex portion 55.

The second convex portion 56 has a tapered shape protruding from the first surface 52 of the first convex portion 55. For example, examples of the tapered shape include a cone shape, a combination of a column shape and a cone shape, and a combination of a frustum shape and a cone shape. In the present embodiment, a plurality of convex patterns 54 are formed on the first surface 52 of the electroforming mold 50. The height of the 2nd convex part 56 is the range of 0.2 mm or more and 2 mm or less, for example, Preferably, they are 0.3 mm or more and 1.5 mm or less. The height of the second convex portion 56 is the distance from the first convex portion 55 to the tip of the second convex portion 56.

In the electroforming process, in order to form a metal film having a uniform thickness on the first surface 12 of the mother die 10, the electroforming mold 50 is preferably circular in plan view. The diameter of the electroforming mold 50 is preferably 200 to 300 mm. The circular shape is not limited to a perfect circle and may be a substantially circular shape.

Here, although the metal electroformed mold 50 was produced as a nesting mold, the nesting mold may be fabricated from a plastic resin.

As will be described later, by performing injection molding using the electroforming mold 50, the electroforming mold 50 is transferred to produce a mold. As shown in FIG. 5, the area of the region where the plurality of convex patterns 54 is formed is smaller than the area of the electroforming mold 50. When a mold is produced on the entire surface of the electroforming mold 50, the produced mold may exceed an appropriate size and include an excess part. This surplus portion may cause resin loss and may require additional processing such as cutting.

In injection molding, in order to facilitate fixing and replacement of the electroforming mold 50, the electroforming mold 50 may be vacuum-sucked using an adsorption plate. During injection molding, it is required that the suction plate is not damaged.

A method for producing a mold by injection molding will be described with reference to the process diagrams of FIGS.

As shown in FIG. 6, a mold 70 including a first mold 72 and a second mold 74 is prepared. A cavity 76 is formed in the mold 70 by clamping the first mold 72 and the second mold 74. The cavity 76 means a space filled with resin.

The electroforming mold 50 is fixed to the first mold 72. The side on which the electroforming mold 50 is fixed is constituted by a flat surface 78. The first mold 72 includes a suction plate 80 on a flat surface 78 as a device for fixing the electroforming mold 50. The first mold 72 includes a suction pipe 82 that communicates with the suction plate 80 in gas. The suction pipe 82 is connected to a vacuum pump (not shown). By driving the vacuum pump, air can be sucked from the surface of the suction plate 80. By using the suction plate 80, the electroforming mold 50 can be easily fixed and replaced.

The suction plate 80 is made of, for example, a porous member. As a porous member, a metal sintered compact, resin, a ceramic, etc. can be mentioned, for example. The suction plate 80 is required not to be damaged from the viewpoint of strength.

If the electroforming mold 50 is formed of a ferromagnetic material such as nickel, the electroforming mold 50 is held on the first mold 72 by the magnetic force of a magnet (not shown) provided on the first mold 72. Good.

A depression 84 (see FIG. 10) is formed on the cavity 76 side of the second mold 74. In the present embodiment, a cavity 76 is formed by the flat surface 78 of the first mold 72 and the recess 84 of the second mold 74. By configuring the first mold 72 and the second mold 74 as described above, the mold can be easily released as described later.

The second mold 74 is formed with a gate 86 communicating with the cavity 76. The gate 86 serves as a resin injection port into the cavity 76 of the mold 70. The gate 86 is in communication with an injection molding machine 88 that supplies resin to the mold 70. In the present embodiment, the resin (molding resin) is filled into the cavity 76 from a direction substantially perpendicular to the longitudinal direction of the cavity 76, that is, a so-called longitudinal direction (injection process).

7, the first mold 72 and the second mold 74 are opened, and the electroforming mold 50 having the convex pattern 54 is placed on the first mold 72. The support layer 120 is disposed in advance in the concave portion 57 on the back surface side of the first convex portion 55 of the electroforming mold 50 (reinforcing step). Details of the support layer 120 will be described later. By sucking air with a vacuum pump through the suction pipe 82, the second surface 58 of the electroforming mold 50 and the support layer 120 are vacuum-sucked to the suction plate 80.

As shown in FIG. 8, in the mold clamping process, in order to form the cavity 76, in the region other than the convex pattern 54 of the electroforming mold 50 and in the region other than the suction plate 80, The electroforming mold 50 is clamped by the second mold 74.

The fact that the electroforming mold 50 is sandwiched between the first mold 72 and the second mold 74 in a region other than the suction plate 80 substantially means that the first mold 72 and the second mold 74 are used in the region other than the suction plate 80. This includes the case where the casting mold 50 is clamped and the case where the electroforming mold 50 is clamped by the first mold 72 and the second mold 74 in a region including a part of the suction plate 80, and the suction plate 80 is damaged by clamping. It means not receiving.

Since the electroforming mold 50 is sandwiched between the first mold 72 and the second mold 74, the inner wall of the second mold 74 is located on the inner side of the outer edge 60 of the electroforming mold 50 as indicated by an arrow A in FIG. Is located. In plan view, the cavity 76 is smaller than the entire surface of the electroforming mold 50. As a result, the volume of the cavity 76 can be reduced, so that loss of resin can be avoided.

In the present embodiment, the first mold 72 and the second mold 74 do not sandwich the electroforming mold 50 in the region of the suction plate 80. As indicated by the arrow B in FIG. 8, since the inner wall of the second mold 74 is located outside the suction plate 80, it is possible to avoid the suction plate 80 from being damaged. The inner side is a direction from the outer edge 60 of the electroforming mold 50 toward the center, and the outer side is a direction from the center of the electroforming mold 50 toward the outer edge 60. It is important to determine the position of the inner wall that defines the size of the cavity 76 (the inner wall that defines the width direction, not the height direction) so that the suction plate 80 is not damaged. As long as the suction plate 80 is not damaged, a part of the suction plate 80 can be clamped by the first mold 72 and the second mold 74.

In this embodiment, the region excluding the end 62 of the electroforming mold 50 is clamped. As shown in FIG. 4, the electroforming mold 50 is manufactured by supplying a current from the conductive ring 26. Therefore, the end 62 of the electroforming mold 50 that contacts the conductive ring 26 may have different physical properties (for example, thickness or surface roughness) as compared with other portions of the electroforming mold 50. .

When the electroforming mold 50 has end portions 62 having different physical properties, when the electroforming mold 50 is used for injection molding, the electroforming mold 50 is stabilized by the first mold 72 and the second mold 74. In some cases, there is a concern about the accuracy of a molded product to be manufactured. Therefore, it is preferable not to pinch the end 62 as in the present embodiment.

However, when there is no problem in the accuracy of the molded product to be produced, the end portion 62 of the electroforming mold 50 may be clamped by the first mold 72 and the second mold 74. The end portion 62 of the electroforming mold 50 is an area inside the outer edge 60 of the electroforming mold 50, and is an area having a physical property different from other areas excluding the convex pattern 54 of the electroforming mold 50. The physical properties are not limited to the thickness.

According to the present embodiment, since the produced electroformed mold 50 can be fixed inside the mold 70 without processing the end portion 62 of the electroformed mold 50, injection molding with high productivity is realized. It becomes possible. Further, since the electroforming mold 50 is vacuum-sucked by the suction plate 80 and is clamped between the first mold 72 and the second mold, the electroforming mold 50 can be stably fixed, so that an accurate injection molding is performed. Can be realized.

As shown in FIG. 9, the resin R is supplied from the injection molding machine 88 to the cavity 76 through the gate 86. The resin R is filled in the cavity 76 while passing between the convex patterns 54 of the electroforming mold 50. As the resin R, it is preferable to use an acrylic or epoxy thermosetting resin or a silicone resin, and it is particularly preferable to use a silicone resin. When the resin R is filled in the cavity 76 of the mold 70, the resin R is then heated to cure the resin R (curing step).

As shown in FIG. 10, in order to release the cured resin R from the electroforming mold 50, the first mold 72 and the second mold 74 that have been clamped are opened. In the mold opening, the first mold 72 and the second mold 74 are moved so as to be relatively separated from each other. As shown in FIG. 10, the second mold 74 has a recess 84 for forming a cavity 76. The cured resin R is a mold 100 in which a concave pattern 102 (see FIG. 14) before release is formed. Hereinafter, the mold 100 may be referred to.

As shown in FIG. 11, the first mold 72 is separated from the second mold 74 and moved to the stage for releasing the mold 100 from the electroforming mold 50. In the present embodiment, since the second mold 74 having the depression 84 is separated from the mold 100, the mold 100 is exposed except for the surface in contact with the electroforming mold 50 fixed to the first mold 72. Become. Therefore, when the mold 100 is released from the electroforming mold 50, the mold 100 can be easily released using the exposed surface of the mold 100.

As shown in FIG. 12, the periphery of the mold 100 is first separated from the electroforming mold 50. The peripheral portion of the mold 100 only needs to include at least two opposing sides when the mold 100 is viewed in plan, and may include all four sides. The peripheral edge means a region from the outer periphery of the mold 100 to the concave pattern 102.

As shown in FIG. 13, the periphery of the mold 100 is gradually separated from the electroforming mold 50. When the mold 100 is made of a silicone resin, the mold 100 has an elastic force. Therefore, when the periphery of the mold 100 is gradually separated, the mold 100 is stretched (elastic deformation). When the peripheral portion of the mold 100 is further separated from the electroforming mold 50, the mold 100 that has been elastically deformed tends to return to its original shape, and thus the mold 100 contracts. The mold 100 is released from the electroforming mold 50 by utilizing the shrinking force of the mold 100. By utilizing the force that the mold 100 is trying to shrink as a releasing force, an excessive force is not applied between the mold 100 and the convex pattern 54 of the electroformed mold 50, thereby suppressing defective release. Is possible.

As shown in FIG. 14, finally, the mold 100 and the convex pattern 54 of the electroforming mold 50 are completely released, and the mold 100 having the concave pattern 102 is produced (mold release step). The concave pattern 102 is a state in which a plurality of concave portions 104 are arranged in an array on the concave pedestal pattern 105.

As a method of separating the peripheral edge of the mold 100 from the electroforming mold 50, it is an exposed surface opposite to the surface on which the concave pattern 102 is formed, and the peripheral edge of the mold 100 is sucked by a suction means, and the peripheral edge is sucked. A method of separating the suction means from the electroforming mold 50 can be given.

When the mold 100 is repeatedly produced from the electroforming mold 50, the convex pattern 54 is gradually damaged, so that it is necessary to replace the electroforming mold 50 with a new one when it is used about 1000 to 10,000 times. In the present embodiment, the electroforming mold 50 can be replaced in a short time by stopping the driving of a vacuum pump (not shown) and reducing the suction force of the suction plate 80.

In the present embodiment, since the end 62 is not processed, a circular electroformed mold 50 in a plan view is used in injection molding.

15 and 16 are process diagrams showing a mold manufacturing method using another type of mold 70. As shown in FIG. 15, a recess 90 is formed in the first mold 72 of the mold 70. An electroforming mold 50 is installed on the bottom surface of the recess 90 and is vacuum-sucked to the first mold 72 via the suction plate 80.

As shown in FIG. 16, the first mold 72 and the second mold 74 are clamped to form the cavity 76. The electroforming mold 50 installed in the recess 90 of the first mold 72 is sandwiched between the first mold 72 and the second mold 74. The inner wall of the second mold 74 is located inside the outer edge 60 of the electroforming mold 50 and outside the suction plate 80. In the present embodiment, the end portion 62 of the electroforming mold 50 is also sandwiched between the first mold 72 and the second mold 74.

As shown in FIG. 16, the resin R is supplied from the injection molding machine 88 to the cavity 76 through the gate 86. The resin R is filled in the cavity 76 while passing between the convex patterns 54 of the electroforming mold 50.

<About support layer>
The electroforming mold 50 that is a nested mold according to the present embodiment has a thickness of 150 μm. As described above, in the mold clamping process, the electroforming mold 50 is clamped by the first mold 72 and the second mold 74. Even when the end portion 62 of the electroforming mold 50 is warped and distribution is generated around the clamping portion, the electroforming die 50 is thin, so that the warping is corrected by a mold clamping pressure of several tens of tons. be able to. Thereby, a gap is not formed in the pinching portion, and the injected resin does not leak. Further, the warpage of the electroformed mold 50 inside the cavity can be corrected so as to follow the first mold 72 by the resin pressure at the time of injection (injection pressure).

However, since the thickness of the electroforming mold 50 is thin, when the support layer 120 is not disposed in the concave portion 57 on the back surface side of the first convex portion 55 having the convex pedestal shape, the convex pedestal shape is changed by the injection pressure of the resin. There was a problem that the desired concave pedestal pattern 105 could not be obtained in the formed mold 100 due to buckling or destruction.

FIG. 17 is a diagram showing a cross-sectional shape of a nested convex pedestal shape before and after injection molding and a concave pedestal pattern shape of a mold produced without arranging a support layer on the back surface of the convex pedestal shape. In FIG. 17, the horizontal axis represents the measurement position coordinates, and the vertical axis represents the height of the convex pedestal shape and the depth (± inversion) of the concave pedestal pattern shape. In FIG. 17, the convex pedestal shape before injection molding is indicated by a thin solid line, the convex pedestal shape after injection molding is indicated by a thick solid line, and the concave pedestal pattern shape (± inversion) of the mold is indicated by a broken line.

The nested convex pedestal shape before injection molding is a portion of 1 mm to 13 mm in the measurement position coordinates shown in FIG. As shown in FIG. 17, the convex pedestal has a diameter of about 12 mm and a height of about 50 μm.

The concave pedestal pattern shape of the produced mold is a portion of 1 mm to 13 mm in the measurement position coordinates shown in FIG. As shown in FIG. 17, the height is about 0 μm in the portion of 3 to 11 mm in the measurement position coordinates. This is because the nested mold is pressed against the first mold surface by the injection pressure, and the nested convex pedestal shape is buckled.

Further, the nested convex pedestal shape after injection molding is a portion of 1 mm to 13 mm in the measurement position coordinates shown in FIG. As shown in FIG. 17, the convex pedestal shape after the injection molding has a height of about 30 μm at a measurement position coordinate of 3 to 11 mm. This is because the plastic deformation was caused by the injection pressure.

In order to avoid the occurrence of such buckling, it can be considered that the thickness of the nested mold is increased. For example, in the case of an electroforming mold, the plating time may be increased to increase the thickness.

However, if the entire nested mold is made thick, the warp cannot be corrected in the mold clamping process, and a gap is generated in the clamping portion. Even if the pinching portion is a gap of about 10 μm, there is a problem that the resin leaks during the injection process. If the resin leaks, manual work increases, such as the need for cleaning for each injection molding, which increases costs such as labor costs and increases the tact time of the apparatus.

Also, a thickness distribution occurs in the mold along the shape of the nested warp. Accordingly, there is a problem that a difference in thickness occurs in the in-plane patch. If the thickness differs for each patch, focus adjustment is required for each patch during inspection. Further, the nested needle-like convex portion may collide with the second mold and be damaged.

In order to prevent the convex pedestal from buckling without increasing the thickness of the nesting mold, it is conceivable not to provide a space for the back surface of the nested convex pedestal. In the case of an electroforming mold, the thickness of electroforming may be increased and processed by grinding or the like.

However, increasing the electroforming thickness increases the electroforming time. If the height of the convex pedestal shape is required to be about 500 μm, the thickness of the electroforming mold is required to be about 750 μm, which increases the cost of the electroforming process.

Also, if there is a thickness distribution in the nested mold, a gap will be generated in the clamping part during mold clamping. In order to prevent this, high processing accuracy is required, resulting in an increase in cost.

In view of such circumstances, in this embodiment, the support layer 120 is disposed in the concave portion 57 on the back surface side of the first convex portion 55.

<First Embodiment>
In the first embodiment, a thermosetting resin is used as the support layer 120.

FIG. 18 is a diagram illustrating a process of creating the support layer 120. As shown in S1 of FIG. 18, a thermosetting resin 130 (heat-resistant epoxy resin) is formed in the recess 57 on the back surface side of the first protrusion 55 (φ12.0 mm, height 50 μm) which is a base shape of the electroforming mold 50. An example of a supporting resin is poured and heated to be cured. Although the thermosetting resin 130 is used here, a silicone resin may be used.

Subsequently, as shown in S2 of FIG. 18, the cured thermosetting resin 130 is polished by the polishing means 132, and the back surface 130A of the thermosetting resin 130 is smoothed (smoothing step). The back surface 130A of the thermosetting resin 130 is smooth so as to be flush with the surface of the second surface 58 of the flat portion 53, which is a region where the convex pattern 54 is not formed on the first surface 52 of the electroforming mold 50. Turned into.

Polishing by the polishing means 132 is a grinding process in which a grindstone is pressed against the thermosetting resin 130 to remove the surface little by little, a superfinishing process by a superfinishing grindstone, a honing process in which a rotating motion and a reciprocating motion are imparted to a grindstone held on a horn, etc. Can be used. The polishing member pressed against the thermosetting resin 130 is not limited to a grindstone, and polishing cloth such as sandpaper or water-resistant paper may be used.

Also, an ultrasonic polishing process (ultrasonic process) using a polishing tool that vibrates ultrasonically, a lapping process that presses the surface of the polishing platen against an object to be polished, a polishing process that is performed using a polishing pad, or the like may be used. Furthermore, the blast process which makes a granular material collide with a process target and provides an unevenness | corrugation on the surface may be sufficient. Blasting here includes shot blasting, shot peening, sand blasting, and the like. Here, polishing was used.

FIG. 19 is a diagram showing the support layer 120 created in this way. The back surface 120 </ b> A of the support layer 120 forms the same plane as the surface of the second surface 58 of the flat portion 53 of the electroforming mold 50.

FIG. 20 is a diagram showing a cross-sectional shape of a concave pedestal pattern shape of a mold manufactured using an electroforming mold 50 in which a support layer 120 of a thermosetting resin 130 is disposed in a concave portion 57. In FIG. 20, the horizontal axis indicates the measurement position coordinates, and the vertical axis indicates the depth (± inversion) of the concave pedestal pattern shape. Here, the concave base pattern shape of the first mold is indicated by a broken line, and the concave base pattern shape of the seventh mold is indicated by a dotted line. Moreover, the shape of the 1st convex part 55 of the electroforming metal mold | die 50 is shown with the continuous line. Note that the second convex portion 56 is ignored.

The first convex portion 55 is a portion of 2.8 mm to 13.8 mm in the measurement position coordinates shown in FIG. As shown in FIG. 20, the first convex portion 55 has a diameter of about 11 mm and a height of about 55 μm.

The concave pedestal pattern shape of the produced mold is a portion of 2.8 mm to 13.8 mm in the measurement position coordinates shown in FIG. As shown in FIG. 20, both the first mold and the seventh mold have a height of about 58 μm at a measurement position coordinate of 2.8 to 13.8 mm. Although the shape of the mold is changed as compared with the shape of the electroforming mold 50, it is presumed that it is caused by polishing pressure or curing shrinkage of the resin.

In this embodiment, the back surface 130A of the cured thermosetting resin 130 is polished by the polishing means 132. However, if the back surface 130A is sufficiently smoothed at the time of curing, the smoothing step is not essential.

Second Embodiment
In the second embodiment, a metal plate 140 is used as the support layer 120. FIG. 21 is a view showing the support layer 120 using the metal plate 140. In FIG. 21, the second convex portion 56 is omitted.

As shown in FIG. 21, a recessed portion 57 (inner diameter: 11.7 mm, depth: 300 μm) on the back surface side of the first convex portion 55 (φ12.0 mm, height: 300 μm) having a nested base shape has a height of 300 μm. A cylindrical metal plate 140 was disposed with its central axis aligned with the central axis of the recess 57. The back surface 140 </ b> A of the metal plate 140 (the back surface 120 </ b> A of the support layer 120) forms the same plane as the surface of the second surface 58 of the flat portion 53 of the electroforming mold 50.

The back surface 140A and the front surface 140B (the surface 120B of the support layer 120 and the surface in contact with the electroforming mold 50) of the metal plate 140 are polished (smoothing process). The back surface 140A may be polished after being disposed in the concave portion 57, or may be polished in advance before being disposed.

The metal plate 140 is set to have a smaller diameter in consideration of the difference in thermal expansion between the electroforming mold 50 and the metal plate 140.

FIG. 22 shows a cross-section of a concave pedestal pattern shape of a mold made using a φ11.0 mm metal plate 140 and a mold made using a φ11.5 mm metal plate 140 as the support layer 120 shown in FIG. 21. It is a figure which shows a shape. In FIG. 22, the horizontal axis indicates the measurement position coordinates, and the vertical axis indicates the depth (± inversion) of the concave pedestal pattern shape. Here, the concave pedestal pattern shape of the mold using the φ11.0 mm metal plate 140 is indicated by a solid line, and the concave pedestal pattern shape of the mold using the φ11.5 mm metal plate 140 is indicated by a broken line.

The concave pedestal pattern shape of the mold produced using the φ11.0 mm metal plate 140 and the mold produced using the φ11.5 mm metal plate 140 is a portion of 3 mm to 14 mm in the measurement position coordinates shown in FIG. is there. As shown in FIG. 22, in any case, the concave pedestal pattern has a diameter of about 11 mm and a depth of about 300 μm.

Thus, it was found that the support layer 120 does not buckle in the radial direction even if a gap with the recess 57 is provided if the height is equal to the depth of the recess 57.

<Third Embodiment>
A fluid may be used as the support layer 120. FIG. 23 is a diagram illustrating the first mold 72, the second mold 74, and the electroforming mold 50 according to the third embodiment, and here, a mold clamping process is illustrated.

As shown in FIG. 23, the suction plate 80 is provided avoiding the position where the concave portion 57 on the back surface side of the first convex portion 55 of the electroforming mold 50 is disposed. The electroforming mold 50 is vacuum-sucked to the suction plate 80.

The first mold 72 is a surface facing the second mold 74, and an opening 152 is provided at each position where the concave portion 57 on the back surface side of the first convex portion 55 of the electroforming mold 50 is disposed. It has been. The plurality of openings 152 are respectively connected to flow paths 154 that communicate with the inside of the first mold 72.

FIG. 24 is a diagram showing a reinforcing step of providing the support layer 120 in the concave portion 57. As shown in FIG. 24, after the mold clamping, the fluid 160 is supplied to the flow path 154 from a fluid supply unit (not shown). The fluid 160 that has passed through the flow path 154 is supplied from the opening 152 to the space of the recess 57 (supply process). When the concave portion 57 is filled with the fluid 160, the support layer 120 made of the fluid 160 is provided in the concave portion 57. Examples of the fluid 160 include liquids such as water and oil.

Thereafter, the cavity 76 is filled with resin (injection process). The support layer 120 formed by the fluid 160 can prevent the first protrusion 55 from buckling.

After filling the recess 57 with the fluid 160, a valve (not shown) provided between the fluid supply unit (not shown) and the flow path 154 may be closed. Thereby, the backflow of the fluid 160 by the injection pressure by an injection process can be prevented.

Although the case where the mold clamping process, the reinforcing process, and the injection process are performed in this order has been described here, the reinforcing process may be performed before the mold clamping process. In this case, the fluid 160 is supplied after the electroforming mold 50 is placed on the first mold 72, and then the clamping process is performed. You may perform a reinforcement process and a mold-clamping process simultaneously. Moreover, you may perform a reinforcement | strengthening process and an injection process simultaneously.

Further, the support layer 120 may be configured by combining at least two of resin, metal, and liquid. The support layer 120 made of two kinds of materials may be provided in one recess 57, or the recess 57 provided with the metal support layer 120 and the recess 57 provided with the resin support layer 120 may be mixed.

<Pattern sheet manufacturing method>
Next, a method for producing a pattern sheet using the mold 100 produced by the above production method will be described. 25 to 28 are process diagrams for manufacturing the pattern sheet 110.

[Polymer solution supply process]
FIG. 25 shows a state where the mold 100 is prepared. The mold 100 is manufactured by the above-described mold manufacturing method. A mold 100 shown in FIG. 25 has a plurality of concave patterns 102. The concave pattern 102 is a state in which a plurality of concave portions 104 are arranged in an array.

FIG. 26 is a diagram showing a supply process of supplying the polymer solution 112 to the concave pattern 102 of the mold 100.

As a material of the polymer solution 112 that forms the pattern sheet 110, it is preferable to use a water-soluble material. As a resin polymer material of the polymer solution 112 used for manufacturing the pattern sheet 110, it is preferable to use a biocompatible resin. Such resins include glucose, maltose, pullulan, sodium chondroitin sulfate, sodium hyaluronate, saccharides such as hydroxyethyl starch, proteins such as gelatin, and biodegradable polymers such as polylactic acid and lactic acid / glycolic acid copolymers. It is preferable to use it. When the pattern sheet 110 is released from the mold 100, the pattern sheet 110 can be released using a base material (not shown), so that the pattern sheet 110 can be suitably used. Although the concentration varies depending on the material, it is preferable to set the concentration so that 10 to 50% by mass of the resin polymer is contained in the polymer solution 112 not containing the drug. Moreover, the solvent used for the polymer solution 112 may be volatile even if it is other than warm water, and alcohol such as ethanol can be used. And in the polymer solution 112, it is possible to dissolve together the medicine to be supplied into the body according to the application. The polymer concentration of the polymer solution 112 containing the drug (when the drug itself is a polymer, the concentration of the polymer excluding the drug) is preferably 0 to 30% by mass.

As a method for preparing the polymer solution 112, when a water-soluble polymer (gelatin or the like) is used, a water-soluble powder may be dissolved in water, and a drug may be added after the dissolution. Alternatively, a water-soluble polymer powder may be put in and dissolved. If it is difficult to dissolve in water, it may be dissolved by heating. The temperature can be appropriately selected depending on the kind of the polymer material, but it is preferable to heat at a temperature of about 20 to 40 ° C. as necessary. The viscosity of the polymer solution 112 is preferably 200 mPa · s or less, more preferably 50 mPa · s or less, in the case of a solution containing a drug. In a solution not containing a drug, it is preferably 2000 mPa · s or less, more preferably 500 mPa · s or less. By appropriately adjusting the viscosity of the polymer solution 112, the polymer solution 112 can be easily injected into the concave pattern 102 of the mold 100. For example, the viscosity of the polymer solution 112 can be measured with a capillary tube viscometer, a falling ball viscometer, a rotary viscometer, or a vibration viscometer.

The drug contained in the polymer solution 112 is not limited as long as it has a function as a drug. In particular, it is preferable to select from peptides, proteins, nucleic acids, polysaccharides, vaccines, pharmaceutical compounds belonging to water-soluble low molecular weight compounds, or cosmetic ingredients.

Examples of the method of injecting the polymer solution 112 into the mold 100 include application using a spin coater.

It is preferable to form a through hole at the tip of the concave portion of the concave pattern 102 of the mold 100. Air in the concave portion of the concave pattern 102 can escape from the through hole. Therefore, the polymer solution 112 can easily enter the recess of the mold 100. Further, this step is preferably performed in a reduced pressure state.

[Drying process]
FIG. 27 is a diagram illustrating a drying process in which the polymer solution 112 is dried to form the polymer sheet 114. For example, the polymer solution 112 supplied to the mold 100 can be dried by blowing air. The polymer sheet 114 means a state after the polymer solution 112 is subjected to a desired drying process. The moisture content of the polymer sheet 114 is set as appropriate. In addition, since it will become difficult to peel when the water content of a polymer becomes too low by drying, it is preferable to leave the water content in the state of maintaining elasticity.

[Polymer sheet release process]
FIG. 28 is a diagram for explaining a polymer sheet releasing step in which the polymer sheet 114 is released from the mold 100 to obtain

individual pattern sheets

110A, 110B, 110C, and 110D. The

pattern sheets

110A, 110B, 110C, and 110D have

convex patterns

116A, 116B, 116C, and 116D on one surface, respectively. Hereinafter, the

pattern sheet

110A, 110B, 110C, and 110D will be represented by the pattern sheet 110, and the

convex pattern

116A, 116B, 116C, and 116D will be represented by the convex pattern 116. FIG. 29 is a perspective view of the pattern sheet 110.

In the present embodiment, the case where the polymer sheet 114 is formed by filling the polymer dissolution solution 112 into the concave pattern 102 of the mold 100 and drying is described. However, the present invention is not limited to this.

For example, the polymer solution 112 containing the drug is filled in the concave pattern 102 of the mold 100 and dried, and then the polymer solution 112 not containing the drug is filled in the concave pattern 102 of the mold 100 and dried to form two layers. A structured polymer sheet 114 can be formed.

In addition, the mold 100 may be used only once for the first time and may be preferably disposable. When the pattern sheet 110 is used as a medicine, it is preferable to make it disposable in consideration of the safety of the manufactured pattern sheet 110 to the living body. Moreover, since it becomes unnecessary to wash | clean the mold 100 by making it disposable, the cost by washing | cleaning can be reduced. In particular, when the pattern sheet 110 is used as a medicine, a high cleaning performance is required, so that the cleaning cost increases.

The convex pattern 116 of the pattern sheet 110 to be manufactured refers to a state in which a plurality of convex portions 118 are arranged in an array at a predetermined number and position. The convex portion 118 means a tapered shape on the tip side, and includes a cone shape and a multistage cone shape. The multi-stage cone shape means a cone shape having side surfaces with different angles from the bottom surface to the tip.

The height of the convex portion 118 is in the range of 0.2 mm to 2 mm, and preferably 0.3 mm to 1.5 mm.

The manufactured pattern sheet 110 having the convex pattern 116 is a replica of the electroformed mold 50 having the convex pattern 54. By making the shape and arrangement of the convex pattern 54 of the electroforming mold 50 a desired shape, the convex pattern 116 of the pattern sheet 110 to be manufactured can be made a desired shape.

<Method for producing electroformed mold having convex pattern>
Next, a method for producing an electroforming mold using the mold 100 will be described. 30 to 32 are process diagrams showing the procedure of a method for producing an electroforming mold using the mold 100. FIG.

FIG. 30 shows a state in which the mold 100 is prepared. The mold 100 is manufactured by the above-described mold manufacturing method. The mold 100 has a plurality of concave patterns 102. The concave pattern 102 is a state in which a plurality of concave portions 104 are arranged in an array.

FIG. 31 is a process diagram showing an electroforming process in which a concave pattern 102 of the mold 100 is filled with metal by electroforming. In the electroforming process, first, a conductive treatment is performed on the mold 100. A metal (for example, nickel) is sputtered on the mold 100 to adhere the metal to the surface of the mold 100 and the concave pattern 102.

Next, the mold 100 that has undergone the conductive treatment is held on the cathode. A metal pellet is held in a metal case to serve as an anode. The cathode for holding the mold 100 and the anode for holding the metal pellet are immersed in an electroforming solution and energized. A metal body 200 is formed by embedding metal in the concave pattern 102 of the mold 100 by electroforming.

FIG. 32 is a process diagram showing a peeling process for peeling the metal body 200 from the mold 100. As shown in FIG. 32, the metal body 200 is peeled from the mold 100, and the electroformed mold 210 having the convex pattern 212 is produced. Peeling means that the metal body 200 and the mold 100 are separated. The convex pattern 212 is an inverted shape of the concave pattern 102 of the mold 100. Here, the electroforming mold 210 is basically the same as the metal body 200 peeled from the mold 100.

The mold can be produced by injection molding by using the electroformed mold 210 thus produced as a nested mold instead of the electroformed mold 50.

<Others>
The technical scope of the present invention is not limited to the scope described in the above embodiment. The configurations and the like in the embodiments can be appropriately combined between the embodiments without departing from the gist of the present invention.

DESCRIPTION OF SYMBOLS 10 Master mold 12 1st surface 14 Recessed pattern 15 1st recessed part 16 2nd recessed part 18 2nd surface 20 Cathode 22 Shaft 24 Cathode plate 26 Conductive ring 30 Electroforming apparatus 32 Electroforming liquid 32A Electroforming liquid 34 Electroforming tank 36 Drain Tank 38 Ni pellet 40 Titanium case 42 Drain piping 44 Supply piping 50 Electroforming mold 52 First surface 53 Flat portion 54 Convex pattern 55 First convex portion 56 Second convex portion 57 Concave portion 58 Second surface 60 Outer edge 62 End portion 70 Mold 72 First mold 74 Second mold 76 Cavity 78 Flat surface 80 Suction plate 82 Suction tube 84 Depression 86 Gate 88 Injection molding machine 90 Depression 100 Mold 102 Concave pattern 104 Concave pattern 105 Concave base pattern 110 Pattern sheet 112 Polymer solution 114 Polymer Sheet 116 Convex pattern 118 Convex portion 120 Support layer

120A Back surface

120B Front surface 1 30 Thermosetting resin 130A Back surface 132 Polishing means 140 Metal plate

140A Back surface

140B Front surface 152 Opening 154 Channel 200 Metal body 210 Electroformed mold 212 Convex pattern

Claims

Preparing a first convex pedestal shape having a recess on the back surface and a nested mold having a second convex needle pattern group on the surface of the first convex pedestal shape;
Preparing a mold having a first mold and a second mold;
A reinforcing step of providing a support layer in the concave portion on the back surface of the first convex pedestal shape provided in the nested mold;
A mold clamping step in which the nested mold is clamped by the first mold and the second mold to form a cavity;
An injection step of filling the cavity with resin for molding;
A method for producing a mold having a concave pedestal pattern.
The method for producing a mold having a concave pedestal pattern according to claim 1, wherein the support layer is made of at least one of a support resin, a metal, and a fluid.
The support layer includes at least one of the support resin and the metal,
The method for producing a mold having a concave pedestal pattern according to claim 2, further comprising a smoothing step of polishing and smoothing at least one of the supporting resin and the metal.
The method for producing a mold having a concave pedestal pattern according to claim 3, wherein the polishing uses at least one of grinding, superfinishing, honing, blasting, ultrasonic processing, lapping, and polishing. .
The support layer includes the fluid;
The method for producing a mold having a concave pedestal pattern according to claim 2, wherein the first mold has a flow path for the fluid.
The method for producing a mold having a concave pedestal pattern according to any one of claims 1 to 5, wherein the molding resin is one of a thermosetting resin and a silicone resin.
After the injection step, a curing step for curing by heating the mold resin in the cavity,
A mold release step of opening the first mold and the second mold after the curing step and releasing the cured mold resin from the insert mold;
The manufacturing method of the mold which has a concave base pattern of any one of Claim 1 to 6 which has these.
The method for producing a mold having a concave pedestal pattern according to any one of claims 1 to 7, wherein the nesting die is one of plastic resin and metal.
The method for producing a mold having a concave pedestal pattern according to any one of claims 1 to 8, wherein the nesting die is an electroforming die and is circular in a plan view.
A step of producing a mold having a concave pedestal pattern by a method for producing a mold having a concave pedestal pattern according to any one of claims 1 to 9,
Supplying a polymer solution to the concave pedestal pattern of the mold; and
A drying step of drying the polymer solution to form a polymer sheet;
A polymer sheet releasing step of releasing the polymer sheet from the mold;
The manufacturing method of the pattern sheet containing this.
The method for producing a pattern sheet according to claim 10, wherein the polymer solution contains a water-soluble material.