WO2015019923A1

WO2015019923A1 - Stamper for microcontact printing and method for producing structure using same

Info

Publication number: WO2015019923A1
Application number: PCT/JP2014/070086
Authority: WO
Inventors: 綾太小島
Original assignee: 綜研化学株式会社
Priority date: 2013-08-09
Filing date: 2014-07-30
Publication date: 2015-02-12
Also published as: TW201522100A; JP2016181530A

Abstract

Provided is a stamper for microcontact printing, which is applicable to two or more kinds of ink having different polarities. The present invention provides a stamper for microcontact printing, which is provided, on a resin layer that has a recessed and projected pattern, with a non-porous coating film that covers at least the projected parts of the recessed and projected pattern and contains an inorganic material and/or an inorganic oxide.

Description

Stamper for micro contact printing and method for manufacturing structure using the same

The present invention relates to a microcontact printing stamper and a method of manufacturing a structure using the same.

Micro contact printing (μCP) is a technique for attaching ink to the surface of a material to be transferred by attaching ink to the tip of a fine-shaped convex part and imprinting it on the material to be transferred (the principle of stamping).

Conventionally, polydimethylsiloxane (PDMS) has been mainly used for a contact imprint stamper (for example, Patent Document 1). The reason is that it is easy to mold, flexible enough to handle curved surfaces, and has releasability capable of transferring (= attaching) ink to a material to be transferred.

Japanese Patent No. 4048887

In the prior art, it has been assumed that the stamper for micro contact printing attaches a specific ink to the stamper and transfers the ink to a material to be transferred. Further, in the conventional stamper, the surface treatment of the stamper is performed so that the releasability with respect to a specific ink is enhanced so that the transfer is appropriately performed. Such a stamper can be used for microcontact printing using an ink having the same polarity as the above-mentioned specific ink (having the same degree of hydrophilicity / lipophilicity), but the polarity is different from that of the above-mentioned specific ink. Since it cannot be used for micro contact printing using ink, there is a problem that the application range is narrow. In addition, since the conventional stamper cannot be used for microcontact printing using two or more types of inks having different polarities, for example, when it is desired to perform microcontact printing of a plurality of types of inks simultaneously, the polarity of the plurality of types of inks is used. It is necessary to match and is troublesome.

The present invention has been made in view of such circumstances, and provides a stamper for microcontact printing that can be applied to two or more types of inks having different polarities.

According to the present invention, there is provided a microcontact printing stamper provided on a resin layer having a concavo-convex shape with a non-porous coating film that covers at least the concavo-convex convex portion and includes at least one of an inorganic substance and an inorganic oxide. Provided.

The conventional approach is that the stamper is designed and manufactured so that the releasability of the ink from the stamper is as high as possible, with an emphasis on ensuring that the ink is transferred onto the transfer material. It was. Contrary to this common sense, the present inventor thought that the releasability of the ink from the stamper may not actually be so high. The reason is that the ink adhering to the stamper has a certain thickness, so even if the ink releasability is low, the portion of the ink adhering to the stamper that is not in contact with the stamper surface is covered without any problem. I thought it was transferred to the transfer material. Based on this idea, the surface energy of the stamper is increased by forming a non-porous coating film containing at least one of an inorganic substance and an inorganic oxide on a resin layer having an uneven shape, and the wettability of the ink to the stamper Improved. When microcontact printing was performed using a stamper produced by the opposite approach to the conventional method, the transferability of the ink was not significantly different from the conventional one, and the polarity of the ink was changed. The epoch-making result that the transfer property of the ink does not change greatly was obtained, and the present invention was completed.

Hereinafter, various embodiments of the present invention will be exemplified. The embodiments described below can be combined with each other.
Preferably, the coating film has a thickness of 5 to 100 nm.
Preferably, the inorganic element of the inorganic substance or inorganic oxide is at least one selected from aluminum, nickel, copper, titanium, silicon, iron, cobalt, chromium, and tin.
Preferably, the inorganic element of the inorganic substance or inorganic oxide is at least one selected from aluminum, nickel, copper, and titanium.
Preferably, the height of the convex portion is 10 nm to 500 μm.
In another aspect, the step of preparing the above-described microcontact printing stamper and bringing the ink into a portion of the coating film covering the convex portion by bringing the ink into contact with the coating film. There is provided a method for manufacturing a structure, comprising a step of attaching, and a step of transferring the ink attached to the coating film to a transfer material.
Preferably, at least two types of inks having different polarities are attached to the coating film.

1 shows a microcontact printing stamper 1 according to an embodiment of the present invention, in which (a) is a cross-sectional view showing a state before the coating film 7 is formed, and (b) shows a state after the coating film 7 is formed. It is sectional drawing shown. It is sectional drawing corresponding to FIG.1 (b) which shows the modification of the shape of the coating film. 4 is a cross-sectional view showing a state in which

inks

8a and 8b are attached to a stamper 1. FIG. 3 is a cross-sectional view showing a state in which a material to be transferred 9 is brought into contact with

inks

8a and 8b on a stamper 1. 3 is a cross-sectional view showing a state in which a transfer material 9 is separated from a stamper 1. FIG. It is a perspective view which shows the structure of the stamper 1 used in the Example of this invention. (A) to (b) are optical micrographs showing transfer results in Example 3 of the present invention, (a) showing results for water-based ink and (b) showing results for oil-based ink.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

As shown in FIGS. 1A and 1B, the microcontact printing stamper 1 according to an embodiment of the present invention covers at least the convex portion 3a of the concavo-convex shape 3 on the resin layer 6 having the concavo-convex shape 3. A non-porous coating film 7 including at least one of an inorganic substance and an inorganic oxide is provided.
Hereinafter, each component will be described in detail.

The resin layer 6 having the concavo-convex shape 3 can be formed by a known imprint technique, and in one example, is formed on a flexible resin base 4 as shown in FIG.

Specifically, the resin substrate 4 is made of, for example, one selected from the group consisting of polyethylene terephthalate, polycarbonate, polyester, polyolefin, polyimide, polysulfone, polyethersulfone, cyclic polyolefin, and polyethylene naphthalate.

On the other hand, examples of the resin forming the resin layer 6 include a thermoplastic resin, a thermosetting resin, and a photocurable resin. Examples of the resin include acrylic resins, styrene resins, olefin resins, polycarbonate resins, polyester resins, epoxy resins, silicone resins, and mixtures of these resins. These resins are preferably used to facilitate the provision of the uneven shape, and when used as a stamper for microcontact printing, the shape stability of the uneven shape is superior to a stamper made of polydimethylsiloxane (PDMS) ( This is a photo-curing resin using an acrylic resin or a styrene resin whose aspect ratio can be 2 or more.

The thickness of the resin layer 6 is usually 50 nm to 1 mm, preferably 500 nm to 500 μm. If it is such thickness, it is easy to form the convex part 3a of moderate height.

When the resin forming the resin layer 6 is a thermoplastic resin, the mold for forming the concavo-convex shape is pressed with a press thickness of 0.5 to 50 MPa while the resin layer 6 is heated to a temperature equal to or higher than the glass transition temperature (Tg). After holding and pressing for 10 to 600 seconds, the resin layer 6 is cooled to a temperature of Tg or less, and the mold is separated from the resin layer 6, whereby the uneven shape 3 can be formed on the resin layer 6. On the other hand, when the resin forming the resin layer 6 is a photocurable resin, the resin layer 6 is cured with light (UV light, visible light) in a state where a mold for forming an uneven shape is pressed against the liquid resin layer 6. The resin layer 6 is cured by irradiating an energy beam capable of curing a resin such as an electron beam, and then the mold is separated, whereby the uneven shape 3 can be formed on the resin layer 6. The light may be irradiated from the resin base material 4 side, and may be irradiated from the mold side when the mold is transparent to the light. When the resin forming the resin layer 6 is a thermosetting resin, the resin layer 6 is heated to the curing temperature in a state in which a mold for forming an uneven shape is pressed against the liquid resin layer 6. The uneven shape 3 can be formed in the resin layer 6 by curing 6 and then separating the mold. The light may be irradiated from the resin base material 4 side, and may be irradiated from the mold side when the mold is transparent to light.

The concavo-convex shape 3 of the resin layer 6 is not particularly limited, but the convex portion 3a of the concavo-convex shape 3 preferably has a height of 10 nm to 500 μm, more preferably 50 nm to 1 μm. If the height of the convex portion 3a is too low, ink adheres to the concave portion 3b of the concavo-convex shape 3 or the ink is easily transferred to the material to be transferred, so that the accuracy of microcontact printing is lowered. On the other hand, if the height of the convex portion 3a is too high, the convex portion 3a is easily deformed when the convex portion 3a is pressed against the material to be transferred. Examples of the uneven shape 3 include a lattice shape, a moth eye, a line, a cylinder, a monolith, a cone, a polygonal pyramid, and a microlens.

Conventionally, the surface of the resin layer 6 has a releasability with respect to the ink used so that the ink used can be easily detached from the stamper and transferred to the transfer material. The surface treatment or the like has been performed so as to be higher, but in the present embodiment, on the contrary, as shown in FIG. 1B, in order to obtain a stamper 1 applicable to two or more types of inks having different polarities. A non-porous coating film 7 containing at least one of an inorganic substance and an inorganic oxide is provided so as to cover at least the convex part 3 a of the concave-convex shape 3 of the resin layer 6. An inorganic substance or an inorganic oxide generally has a surface energy higher than that of a resin, and by providing the coating film 7 on the convex portion 3a, the wettability with respect to various inks on the convex portion 3a is increased. ing. The coating film 7 may be formed along the concavo-convex shape 3 as shown in FIG. 1B, or may be formed only on the convex portion 3a as shown in FIG.

Corona discharge treatment is known as a method for improving wettability on the surface. However, since the size of the concavo-convex shape 3 is very small in the microcontact printing stamper 1, the concavo-convex shape 3 is destroyed during the corona discharge treatment. In some cases, we gave up improving the wettability by corona discharge treatment. In addition, although the surface of the resin layer 6 may be modified with a chemical substance, the surface modification with a chemical substance can improve the wettability of a specific ink, but the wettability of two or more types of inks having different polarities. Since it is not easy to improve the nature, we gave up on this method. Under such circumstances, the present inventor conceived of providing a non-porous coating film 7 containing at least one of an inorganic substance and an inorganic oxide, and destroying the uneven shape 3 by providing this coating film 7. And succeeded in improving the wettability of two or more inks having different polarities.

The coating film 7 contains at least one of an inorganic substance and an inorganic oxide, and may be any of a film made of an inorganic substance, a film made of an inorganic oxide, and a laminated film of an inorganic substance and an inorganic oxide. Further, when a film made of an inorganic material is formed, the surface thereof may be naturally oxidized by oxygen in the air. However, a film containing an inorganic oxide by such natural oxidation may be used. The inorganic element of an inorganic substance or an inorganic oxide should just be a solid at 20 degreeC, and metals, such as aluminum, nickel, copper, titanium, iron, cobalt, chromium, tin, silicon, etc. are mentioned. Of these, aluminum, nickel, copper, and titanium are preferred from the viewpoints of being industrially used, forming a thin film relatively easily, and establishing a method.
Although the formation method of the coating film 7 is not specifically limited, For example, sputtering, vapor deposition, etc. are mentioned. Moreover, in this embodiment, the coating film 7 is non-porous. The stamper of this embodiment can be applied to two or more types of inks having different polarities, and changing the type of ink is also assumed as a use, but if the coating film 7 is porous, the coating film The ink is absorbed in the ink 7 and it is difficult to remove the ink from the stamper, and it is difficult to change the type of ink.

In the prior art, since the ink is directly applied onto the resin stamper, the stamper absorbs the ink and swells, and there is a problem that the durability is lowered. Since the resin layer 6 is covered with the coating film 7, the problem of swelling of the resin layer 6 does not occur, and the durability of the stamper 1 is improved.

Next, microcontact printing using the stamper 1 of the present embodiment will be described with reference to FIGS.
First, as shown in FIG. 3, the

inks

8 a and 8 b are attached to the portion 7 a of the coating film 7 that covers the convex portions 3 a by bringing the

inks

8 a and 8 b into contact with the coating film 7 of the stamper 1. Although FIG. 3 shows a state where the

inks

8a and 8b are attached only to the portion 7a, the

ink

8a and 8b are attached to the portion 7b covering the side surface of the convex portion 3a and the portion 7c covering the region between the adjacent convex portions 3a. Since the transferred ink is not transferred, the ink may adhere to these

portions

7b and 7c. In FIG. 3, two types of

inks

8a and 8b having different polarities are attached, but the type of ink to be attached may be one type or three or more types. In this specification, “different in polarity” means that the degree of hydrophilicity / lipophilicity is different, and typical examples of the two types of

inks

8a and 8b having different polarities are oil-based ink and water-based ink. It is. Further, in the present specification, the “ink” means a liquid transferred to a material to be transferred by microcontact printing, in which a pigment, a dye, a resin is dispersed or dissolved in a liquid such as water or an organic solvent, Liquid resin is included.

Next, after the material to be transferred 9 is brought into contact with the

inks

8a and 8b as shown in FIG. 4, when the material 9 to be transferred is separated from the

inks

8a and 8b as shown in FIG. 5, the

inks

8a and 8b are transferred. Transferred to material 9. In this embodiment, since the surface energy of the coating film 7 is large, the

inks

8a and 8b tend to remain on the coating film 7 as shown in FIG. Thus, even if a part of the

inks

8a and 8b remains on the coating film 7, there is no particular problem because a desired pattern can be formed with the

inks

8a and 8b transferred to the transfer material 9. However, substantially all of the

inks

8a and 8b are transferred to the transfer material 9 by increasing the surface energy of the transfer material 9 or optimizing the force for pressing the transfer material 9 against the

inks

8a and 8b. You may make it do.

By the above method, a structure in which the

inks

8a and 8b are transferred onto the transfer material 9 is obtained. An example of the structure is a mold having fine unevenness used in the imprint technique, but the object of the present embodiment is not limited to this, and is intended for various structures that can be manufactured by the above method.

As shown in FIG. 6, a resin layer 6 having a lattice-like uneven shape 3 was formed on a resin base material 4, and this resin layer 6 was covered with a coating film 7 to form a stamper 1. A polyethylene terephthalate (PET) substrate was used as the resin substrate 4, and the resin layer 6 was formed of UV curable resin in Examples 1 to 4 in Table 1, and was formed of polydimethylsiloxane (PDMS) in Comparative Example 1. . In Examples 1 to 4 in Table 1, the peritoneum 7 was formed to a thickness of 20 nm by sputtering with aluminum, nickel, copper, and titanium. The convex part 3a of the concave / convex shape 3 has a width of 20 μm, and the concave part 3b has a square shape with a side of 200 μm. The height of the convex part 3a was 20 μm.

Next, oil-based ink or water-based ink was attached to the portion 7a of the coating film 7 covering the convex portion 3a, and this ink was transferred to the material to be transferred. A PET film was used as the material to be transferred. Further, during the transfer, a pressure of 0.1 MPa was applied between the stamper 1 and the material to be transferred. As the oil-based ink, a mixed liquid (50 wt%) diluted with isopropyl alcohol in UV curable resin PAK-01 (manufactured by Toyo Gosei Co., Ltd.) for nanoimprinting was used. As the water-based ink, commercially available water-based WA-RI91 (manufactured by Dragonfly Pencil Co., Ltd., water 70 wt%, polyhydric alcohol 20 wt%, pigment 10 wt%) was used.

The state of transfer to the material to be transferred was evaluated according to the following criteria. The results are shown in Table 1.
◎: A line having a uniform thickness could be transferred. ○: Transfer was performed without interruption of the line, but the thickness of the line was not uniform. △: Transfer was performed, but the line was interrupted. ×: not transcribed at all

As shown in Table 1, in any of Examples 1 to 4, the transfer evaluation results were good for both the water-based ink and the oil-based ink. Among Examples 1 to 4, the most excellent result was obtained in Example 3 in which the coating film was formed with copper. The transfer result obtained in Example 3 is shown in FIG. It can be seen that a grid-like shape is printed with both water-based ink and oil-based ink.
On the other hand, in Comparative Example 1, good results were obtained for the oil-based ink, but transfer could not be performed with the water-based ink.

1: stamper for micro contact printing, 3: uneven shape, 4: resin base material, 6: resin layer, 7: coating film

Claims

A stamper for microcontact printing, comprising: a resin layer having a concavo-convex shape; and a nonporous coating film that covers at least the concavo-convex convex portion and includes at least one of an inorganic substance and an inorganic oxide.
The stamper according to claim 1, wherein the coating film has a thickness of 5 to 100 nm.
The stamper according to claim 1 or 2, wherein the inorganic element or inorganic element of the inorganic oxide is at least one selected from aluminum, nickel, copper, titanium, silicon, iron, cobalt, chromium, and tin.
The stamper according to claim 1 or 2, wherein the inorganic element or the inorganic element of the inorganic oxide is at least one selected from aluminum, nickel, copper, and titanium.
The stamper according to any one of claims 1 to 4, wherein a height of the convex portion is 10 nm to 500 µm.
Preparing a microcontact printing stamper according to any one of claims 1 to 5,
Attaching the ink to a portion of the coating film that covers the convex portion by bringing the ink into contact with the coating film;
A method for producing a structure, comprising a step of transferring the ink adhered to the coating film onto a material to be transferred.
The structure manufacturing method according to claim 6, wherein at least two types of inks having different polarities are attached to the coating film.