TW201522100A - Stamper for microcontact printing and method for producing structure using same - Google Patents

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

a stamper for microcontact printing, and a structure using the film Production method

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

Micro-contact printing (μ CP) is to let ink adhere to the front end of a minute-shaped convex portion and imprint it on the "transfer material" (stamp principle), thereby making the surface of the material to be transferred The technique of attaching ink to it.

A contact die for a contact imprint in the prior art is used, and a polydimethyl siloxane (PDMS) is mainly used (for example, Patent Document 1). The reason for this is that the molding is simple, and it is flexible to the curved surface, and has a mold release property of transferring (adhering to) the ink to the material to be transferred.

[Background Technical Literature]

[Patent Literature]

[Patent Document 1] Japanese Patent No. 4048877

In the prior art, it is assumed that, in the microcontact printing stamper, a specific ink is attached to the stamper, and the ink is transferred onto the material to be transferred. Further, in the prior art stamper, in order to appropriately perform the transfer, the surface of the stamper is treated to increase the mold release property with respect to the specific ink. In the microcontact printing using an ink having the same polarity (the same degree of hydrophilicity and lipophilicity) as the above specific ink, although such a stamper can be used, microcontact printing using an ink different in polarity from the above specific ink is used. However, such a stamper cannot be used, so the problem is that the scope of application is narrow. Further, in the microcontact printing using two or more kinds of inks having different polarities, the stamper of the prior art cannot be used. Therefore, for example, when a plurality of colors of ink are to be used for microcontact printing at the same time, it is necessary to match the polarity of a plurality of inks, which is troublesome.

The present invention has been made in view of the above problems encountered in practice, and provides a stamper for microcontact printing which can be applied to two or more kinds of inks having different polarities.

The present invention provides a stamper for microcontact printing comprising a non-porous coating film containing at least one of an inorganic material and an inorganic oxide on a concave-convex resin layer covering at least the convex portion of the uneven shape.

The method in the prior art is to pay attention to the transfer of the transfer ink to the material to be transferred, design. It is common knowledge to manufacture a film to make the release property of the ink from the stamper as large as possible. The inventors, contrary to this common sense, believe that it is practically possible that the release property of the ink from the stamper is not so large. The reason for the thought is that the ink attached to the stamper has a certain thickness, and the mold release property of the ink is low, and the portion of the ink attached to the stamper that is not in contact with the surface of the stamper is transferred to the sheet without any problem. On the transfer material. Next, according to the idea, a non-porous coating film is formed on the resin layer having the uneven shape, and the non-porous coating film contains at least one inorganic substance and inorganic oxide, thereby increasing the surface energy of the stamper. The wettability of the ink of the stamper is improved. Then, when the stamper was produced and used in the opposite manner to the prior art, when attempting to perform microcontact printing, it was found that the transfer property of the ink did not largely change, and even if the polarity of the ink was changed, the transferability of the ink was not large. Variety. This is a breakthrough result, thus completing the present invention.

Hereinafter, various embodiments of the invention are 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 or inorganic oxide is at least one of aluminum, nickel, copper, titanium, ruthenium, iron, cobalt, chromium, and tin.

Preferably, the inorganic element of the inorganic substance or inorganic oxide is at least one of aluminum, nickel, copper, and titanium.

Preferably, the height of the convex portion is 10 nm to 500 μm.

In addition, from another viewpoint, a method for manufacturing a structure is provided, which has the following steps: Preparing the above-described step of the microcontact printing stamper, bringing the ink into contact with the coating film, thereby attaching the ink to the convex portion covering the coating film, and attaching the coating to the coating The step of transferring the ink of the film to the material to be transferred.

Preferably, at least two kinds of inks having different polarities are attached to the coating film.

1‧‧‧Microcontact printing stamper

3‧‧‧ concave shape

4‧‧‧Resin substrate

6‧‧‧ resin layer

7‧‧‧ Cover film

Fig. 1 shows a stamper 1 for microcontact printing according to an embodiment of the present invention, wherein (a) is a cross-sectional view of a state before the coating film 7 is formed, and (b) is a section of a state after the coating film 7 is formed. Figure.

Fig. 2 is a cross-sectional view corresponding to Fig. 1(b) showing a modification of the shape of the coating film 7.

Fig. 3 is a cross-sectional view showing a state in which 8a, 8b are adhered to the pressure film 1.

4 is a cross-sectional view showing a state in which the material to be transferred 9 is brought into contact with the inks 8a, 8b of the stamper 1.

FIG. 5 is a cross-sectional view showing a state in which the transfer material 9 is separated from the stamper 1.

Figure 6 is a perspective view showing the structure of a stamper 1 used in the embodiment of the present invention.

7(a) to 7(b) are optical micrographs of the transfer result in Example 3 of the present invention, wherein (a) shows an aqueous ink and (b) shows an oily ink.

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

As shown in FIGS. 1(a) to (b), a micro-contact printing stamper 1 according to an embodiment of the present invention has: The non-porous coating film 7 is provided on the resin layer 6 having the uneven shape 3, and the non-porous coating film 7 covers at least one of the inorganic material and the inorganic oxide at least the convex portion 3a of the uneven shape 3.

Hereinafter, each component will be described in detail.

The resin layer 6 having the uneven shape 3 can be formed by a known imprint technique, and is formed on the flexible resin substrate 4 as shown in Fig. 1(a) as an example.

As the resin substrate 4, specific examples are: polyethylene terephthalate, polycarbonate, polyester, polyolefin, polyimine (polyimide), polysulfone, polyether sulfone, cyclic polyolefin, and polyethylene naphthalate.

On the other hand, as the resin forming the resin layer 6, for example, a thermoplastic resin, a thermosetting resin or a photocurable resin is used. As the resin, there are, for example, an acrylic resin, a styrene resin, an olefin resin, a polycarbonate resin, a polyester resin, an epoxy resin, and a silicone resin. And a mixture of these resins. Among these resins, a photocurable resin using a resin which is used in the case of easily providing a concave-convex shape or a die for microcontact printing, and polydimethyl siloxane (PDMS) is preferably used. An acrylic resin or a styrene resin having a shape stability of an uneven shape (an aspect ratio of 2 or more) can be obtained as compared with a stamper.

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

When the resin forming the resin layer 6 is a thermoplastic resin, the hot resin layer 6 is heated to a temperature equal to or higher than the glass transition temperature (Tg), and is pressed against the concave-convex shape molding die at a pressure of 0.5 to 50 MPa. After pressing for 10 to 600 seconds, the resin layer 6 is cooled to a temperature lower than Tg, 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 in which the concave-convex shape molding die is pressed against the liquid resin layer 6). Irradiation is performed by an electron beam or the like which is a general term of the energy line of the hardened resin. After the resin layer 6 is cured, the mold is removed, whereby the uneven shape 3 can be formed on the resin layer 6. Light can be irradiated from the resin substrate 4 side, and if the mold is light-transmitted, it can be irradiated from the mold side. In the case where the resin of the resin layer 6 is a thermosetting resin, the resin layer 6 is heated to a curing temperature in a state where the concave-convex shape molding die is pressed against the liquid resin layer 6, and the resin layer 6 is cured, and then the mold is removed. Thereby, the uneven shape 3 can be formed on the resin layer 6. Light can be irradiated from the resin substrate 4 side, and if the mold is light-transmitted, it can be irradiated from the mold side.

The uneven shape 3 of the resin layer 6 is not particularly limited, but the height of the convex portion 3a of the uneven shape 3 is preferably 10 nm to 500 μm, and more preferably 50 nm to 1 μm. Since the height of the convex portion 3a is too low, the ink adheres to the concave portion 3b of the uneven shape 3, or the ink is easily transferred onto the material to be transferred, so that the precision of microcontact printing is lowered. On the other hand, if the height of the convex portion 3a is too high, it is transferred. When the material is pressed against the convex portion 3a, the convex portion 3a is easily deformed. The concavo-convex shape 3 may be, for example, a lattice shape, a Moth-eye shape, a linear shape, a cylindrical shape, a monolith shape, a conical shape, a polygonal pyramid shape, or a microlens shape.

In the prior art, in order to allow the ink to be easily detached from the stamper, the surface of the resin layer 6 is transferred onto the material to be transferred, and the surface of the resin layer 6 is surface-treated to release the ink. In the present embodiment, in contrast to this, in order to obtain a stamper 1 which can be applied to two or more types of inks having different polarities, as shown in FIG. 1(b), in order to cover at least the uneven shape 3 of the resin layer 6. The convex portion 3a is provided with a non-porous coating film 7 having at least one of an inorganic substance and an inorganic oxide. The inorganic substance or the inorganic oxide generally has a larger surface energy than the resin, and since the coating film 7 is provided on the convex portion 3a, the wettability with respect to various inks on the convex portion 3a is improved. Further, as shown in FIG. 1(b), the cover film 7 may be formed along the uneven shape 3, or may be formed only on the convex portion 3a as shown in FIG. 2.

Corona discharge treatment is known as a method for improving the wettability on the surface. However, since the uneven shape 3 of the micro-contact printing stamper 1 is extremely small, the uneven shape 3 may be destroyed during the corona discharge treatment. It is no longer considered to improve the wettability by corona discharge treatment. Further, the inventors have considered that the surface of the resin layer 6 is modified with a chemical substance. However, even if the surface modification using a chemical substance can improve the wettability of a specific ink, it is not easy to improve the wettability of two or more kinds of inks having different polarities. So this method will not work. In this case, the inventors thought that by providing the non-porous coating film 7 including at least one of an inorganic substance and an inorganic oxide, since the coating film 7 is provided, the uneven shape 3 is not broken, and the polarity is increased by 2 The wettability of the above inks was successful.

The coating film 7 contains at least one of an inorganic substance and an inorganic oxide, and may be a film composed of an inorganic substance, a film composed of an inorganic oxide, or a laminated film of an inorganic substance and an inorganic oxide. . Further, when a film composed of an inorganic substance is formed, there is a case where the surface is naturally oxidized by oxygen in the air, and a film containing such an naturally oxidized inorganic oxide may be used. The inorganic element of the inorganic or inorganic oxide may be solid at 20 ° C, and may be, for example, a metal such as aluminum, nickel, copper, titanium, iron, cobalt, chromium, tin, or ruthenium. Among them, aluminum, nickel, copper, and titanium are preferable in view of industrial application, and it is relatively easy to form a film and a method thereof has been established. The method for forming the coating film 7 is not particularly limited, and may be, for example, a sputtering method or a vapor deposition method. Further, in the present embodiment, the coating film 7 is non-porous. The stamper of the present embodiment can be applied to two or more kinds of inks having different polarities, and one of the uses is assumed to be the type of the ink to be changed. However, if the cover film 7 is porous, the ink is absorbed in the cover film 7 from It is difficult to remove the ink in the stamper, making it difficult to change the kind of ink.

Further, in the prior art, since the ink is directly applied to the resin stamper, the stamper absorbs the ink to swell and the durability is lowered. However, in the present embodiment, the resin layer 6 is covered with the cover film 7, and the resin layer The problem of expansion 6 does not occur, and the durability of the stamper 1 is improved.

Next, the microcontact printing of the stamper 1 of the present embodiment will be described with reference to Figs. 3 to 5 .

First, as shown in Fig. 3, the inks 8a, 8b are brought into contact with the stamper 1 of the stamper 1, whereby the inks 8a, 8b are attached to the portion 7a covering the convex portion 3a of the cover film 7.

In Fig. 3, only the state of the inks 8a, 8b attached to the portion 7a is shown, but the portion 7b covering the side of the convex portion 3a or the portion 7c covering the region between the adjacent convex portions 3a is not transferred and attached. It is also possible that ink is not attached to these portions 7b, 7c. In FIG. 3, the two types of inks 8a and 8b having different polarities are attached, but the type of the adhered ink may be one type or three or more types. In this specification, the term "different polarity" means hydrophilicity. Typical examples of the two types of inks 8a, 8b having different degrees of lipophilicity are: oily ink and aqueous ink. In addition, the term "ink" in the present specification means a liquid which is printed by microcontact printing on a material to be transferred, and includes a substance in which a pigment, a dye, or a resin is dispersed or dissolved in a liquid such as water or an organic solvent. , or liquid resin.

Next, as shown in Fig. 4, after the inks 8a, 8b are brought into contact with the material to be transferred 9, as shown in Fig. 5, when the inks 8a, 8b are separated from the material to be transferred 9, the inks 8a, 8b are transferred to the material to be transferred. 9 on. Further, in the present embodiment, the surface energy of the coating film 7 is large, and the inks 8a, 8b are easily left on the coating film 7 as shown in Fig. 5 . Thus, even if a part of the inks 8a, 8b remains on the cover film 7, and the inks 8a, 8b transferred to the material to be transferred 9 can form a desired pattern, there is no particular problem. However, the surface energy of the material to be transferred 9 is large, or the pressing force for pressing the material 9 to be pressed against the inks 8a, 8b is optimized, whereby the inks 8a, 8b are substantially all transferred to the transfer. Material 9 is also possible.

In the above method, a structure in which the inks 8a, 8b are transferred onto the material to be transferred 9 can be obtained. An example of the structure is a mold having minute irregularities used in the Imprint technique, but the article of the present embodiment is not limited thereto, and the object to be used may be: Various structures that can be fabricated by the method.

[Examples]

As shown in FIG. 6, a resin layer 6 having a lattice-like uneven shape 3 is formed on the resin substrate 4, and the resin layer 6 is covered with the coating film 7 to form a stamper 1. A polyethylene terephthalate (PET) substrate was used for the resin substrate 4, and in Examples 1 to 4 of Table 1, the resin layer 6 was formed of a UV curable resin, and in Comparative Example 1, It is formed by polydimethyl siloxane (PDMS). In Examples 1 to 4 of Table 1, the peritoneum 7 was sputtered using aluminum, nickel, copper, and titanium, and the thickness thereof was 20 nm. The width of the convex portion 3a of the uneven shape 3 is 20 μm, and the concave portion 3b is a square having a side length of 200 μm. The height of the convex portion 3a is 20 μm.

Next, an oily ink or an aqueous ink is adhered to the portion 7a covered by the convex portion 3a in the coating film 7, and the ink is transferred onto the material to be transferred. A PET film was used on the material to be transferred. Further, a pressure of 0.1 MPa was applied between the stamper 1 and the material to be transferred at the time of transfer. As the oil-based ink, a mixed liquid (50% by weight) obtained by diluting with isopropyl alcohol in a UV curable resin PAK-01 (manufactured by Toyo Seisakusho Co., Ltd.) was used. As the aqueous ink, commercially available water-based WA-RI91 (manufactured by Tombow Co., Ltd., water 70% by weight, polyol 20% by weight, pigment 10% by weight) was used.

The state of the transfer to the material to be transferred was evaluated by the following criteria. The results are shown in Table 1.

◎: It is possible to transfer a line of uniform thickness

○: During the transfer process, the line is uninterrupted, but the thickness of the line is uneven.

△: Although the transfer was performed, the line was broken in the middle.

×: not transferred at all

As shown in Table 1, in any of Examples 1 to 4, the transfer evaluation results of both the aqueous ink and the oily ink were good. Further, in Examples 1 to 4, the results obtained in Example 3 in which a coating film was formed of copper were the best. The transfer result obtained in Example 3 is shown in FIG. In both the aqueous ink and the oily ink, a lattice-like shape is printed.

On the other hand, in Comparative Example 1, although good results were obtained with respect to the oily ink, the aqueous ink could not be transferred.

1‧‧‧Microcontact printing stamper

3‧‧‧ concave shape

4‧‧‧Resin substrate

6‧‧‧ resin layer

7‧‧‧ Cover film

Claims (7)

A micro-contact printing stamper comprising: a non-porous coating film provided on a resin layer having a concavo-convex shape, covering at least the convex portion of the concavo-convex shape, and containing inorganic substances and inorganic substances At least one of the oxides. The stamper as claimed in claim 1, wherein the thickness of the coating film is 5 to 100 nm. The stamper according to claim 1 or 2, wherein the inorganic element of the inorganic or inorganic oxide may be at least one of aluminum, nickel, copper, titanium, ruthenium, iron, cobalt, chromium, and tin. The stamper according to claim 1 or 2, wherein the inorganic element of the inorganic or inorganic oxide is at least one of aluminum, nickel, copper, and titanium. The stamper according to any one of claims 1 to 4, wherein the height of the convex portion is 10 nm to 500 μm. A method of manufacturing a structure, comprising the steps of: preparing a micro-contact printing stamper according to any one of claims 1 to 5; contacting the ink with the coating film, thereby causing the ink to a step of adhering to a portion covering the convex portion of the coating film; and a step of transferring ink adhered to the coating film to a material to be transferred. The method for producing a structure according to claim 6, wherein at least two kinds of inks having different polarities are attached to the coating film.