JP6433261B2 - Application method - Google Patents

Description

  The present invention relates to a coating method.

  Conventionally, in the field of nanoimprint or the like, in order to shape a fine structure in an optical element or the like, a mold in which a fine structure is formed in advance is used, and the fine structure of the mold is used as a glass substrate, a plastic substrate, a plastic film, or the like. The method of transferring to the surface is used (see Patent Document 1 and Patent Document 2).

  As a method for transferring the fine structure of the mold, a mold on which a fine pattern such as a fine groove or hole is formed is used as an original plate (also called a mold or a template), and the original fine pattern is pressed against a transfer material. Examples of the method include a method of mechanically transferring a pattern, a method of transferring a fine pattern of an original plate against a thermoplastic resin, and the like. In addition, a method (UV nanoimprint) in which a photocurable resin is applied onto a fine pattern of an original plate for phototransfer has been proposed (see Patent Document 3). In these methods, the resolution of the fine structure transferred to the transfer material is determined by the precision of the fine pattern formed on the original. For this reason, if a mold (original) on which a high-precision fine pattern is formed can be produced, the microstructure can be transferred with an inexpensive apparatus by repeatedly using the original. As molds used as original plates, parallel plate molds (also called wafers or plates) and cylindrical (roller) molds are generally known (see Patent Document 4 and Non-Patent Document 1).

  Since the cylindrical mold can be adapted to a roll-to-roll process, combining with UV nanoimprint significantly improves productivity in nanoimprint, such as shortening tact time and increasing area.

  On the other hand, there are various types of coating methods in the roll-to-roll process, and die coating and gravure coating are examples of coating methods for which technological innovation is particularly advanced in recent years. The application is application of an active material to a photographic light-sensitive material, an optical correction film, an antireflection film, or a metal foil for battery electrodes, and the application technique requires not only continuous application but also intermittent application.

  As a gravure coating applied to an arbitrary area of a base material, it has been proposed to grind a gravure roll so as to be in non-contact with the base material (see Patent Document 5).

  In addition, a variety of gravure coating methods such as gravure coating using a small-diameter gravure roll, gravure coating using a backup roll, and gravure coating contacting with a base material are proposed (see Non-Patent Document 2). ).

US Pat. No. 5,259,926 US Pat. No. 5,772,905 JP 2005-238719 A JP 2006-5022 A JP 2009-28719 A

Hua Tan, Andrew Gibertson, Stephen Y. Chou, “Roller nanoimprint lithography”. Vac. Sci. Technol. B16 (6), 3926 (1998) "Processing Technology Handbook" edited by Processing Technology Association, Inc. Processing Technology Association, 2006, P45-84, P169-171

  In roll-to-roll nanoimprinting, UV nanoimprinting is essential to improve productivity. It is desirable that the photocurable resin to be used has a low viscosity because it is easy to fill the nanostructure. The coating thickness of the photocurable resin is preferably thin. If the coating thickness is large, the resin overflows due to pressing during nanoimprinting, and the overflowing photocurable resin is a cylindrical mold or substrate. There is a problem of contaminating the film.

  Die coating is effective when the coating thickness is thick or intermittent coating, but there are high technical barriers for thin film coating such as coating technology in nanoimprinting. When applying several μm, it is necessary to dilute 10 times or more with a solvent. In addition, when thin film coating is used, variations in coating thickness not only in the film width direction but also in the flow direction occur unless the shim of the die, the pressure control of the liquid feeding, and the distance between the die lip and the film are precisely controlled. To do.

  Since gravure coating can reduce the coating film thickness, it is effective for coating in nanoimprinting. In the gravure coating described in Patent Document 5, an application part that comes into contact with the base material on the gravure roll, and a non-application part that is not in contact with the base material is provided by making the diameter of the gravure roll smaller than the application part. Techniques for applying to these areas have been proposed. However, as in the application described in Patent Document 5, if the coating thickness is several tens of μm like an electrode member, there is no problem just by applying a small diameter processing to the gravure roll, but it is required for the coating technique of the nanoimprint apparatus. When applied to a coating film thickness of several μm or less, there is a problem that the photocurable resin becomes thick at the end of the coating portion that comes into contact with the substrate.

  In gravure coating using a backup roll, the accuracy of the backup roll itself and the mounting accuracy are required. When the rotation of the backup roll is eccentric, not only the film thickness becomes uneven, but also the generation of scratches becomes a problem because the substrate is sandwiched between the gravure roll and the backup roll. The small-diameter gravure roll is suitable for thin film coating, but the wet film thickness is several μm or more, and the ratio of the rotational speed (Vr) of the small-diameter gravure roll to the running speed (Vf) of the substrate (hereinafter referred to as “the thickness of the gravure roll”) If the peripheral speed ratio (Vr / Vf) is not controlled, it is difficult to obtain a stable coating film surface. Therefore, as described in Non-Patent Document 2, if a smooth coating surface is to be obtained, a peripheral speed ratio of about 1.00 to about 2.00 is optimal, and if the peripheral speed ratio is 0.60 or less, the coating solution The supply has not been able to keep up.

  As a result of studying the peripheral speed ratio of about 1.00 to about 2.00 in accordance with the above-described known techniques, the present inventors have found that the coating method for nanoimprinting does not reduce the coating film thickness, and the resin is not used during transfer. Overflowing and overflowing photocurable resin has a problem of contaminating a cylindrical mold and a base film.

  The present invention has been made in view of the above-described problems, and can reduce the coating film thickness and maintain a good coating film thickness distribution. It is an object of the present invention to provide a coating method that can suppress contamination of a transfer material.

  As a result of intensive studies in order to solve the above problems, the present inventors have been able to reduce the coating film thickness in the coating method in the roll-to-roll nanoimprint apparatus, and have a good coating film thickness distribution. By maintaining the above, it was found that contamination of the mold and transferred material by excess transfer resin can be suppressed, and the present invention has been made based on this finding. In addition, this invention is not limited to a nanoimprint apparatus, It can apply also in the use where thin film coating is required. That is, the present invention is as follows.

The coating method of the present invention includes a first transfer step in which the transfer resin is transferred onto the peripheral surface while rotating the roll with the liquid transfer resin engraved with a plurality of grooves on the peripheral surface, and the roll Scraping off the excess transfer resin transferred to the surface by a scraping member, and a second transfer step of transferring the transfer resin from the roll onto the surface of the film-like substrate to be transferred. The roll has a coating portion that contacts the surface of the substrate to be transferred in a state where the transfer resin is present in the plurality of grooves in the second transition step, and a diameter smaller than the diameter of the coating portion. And an uncoated portion that does not contact the outermost surface of the transfer resin in the first transfer step, and the traveling speed Vf of the transferred substrate is 3.0 m / min or less, and the roll Rotation speed Vr and the substrate to be transferred The ratio of the running speed Vf (Vr / Vf) is Ri der 0.10 to 0.50, the second of the transfer target substrate in which the transfer resin is transferred from the roll by the transition step, 6.0 cm characterized in be used in actual roll-to-roll nanoimprint using a mold having a nano shape volume of ^{3 /} m ² or less.

  With this configuration, even when the peripheral speed ratio is 0.10 or more and 0.50 or less, the transfer resin can be transferred to the transfer substrate with a thin film and without unevenness. Thereby, contamination to a metal mold | die and a to-be-transferred material can be suppressed.

  In the coating method of the present invention, it is preferable that the traveling speed Vf is 1.0 m / min or less and the ratio (Vr / Vf) is 0.10 or more and 0.20 or less.

  In this case, resin contamination to the substrate and the roll after transfer can be reduced even if the viscosity is low, regardless of the viscosity of the transfer resin.

  According to the present invention, there is provided a coating method capable of reducing the coating film thickness and suppressing contamination of the mold and the transfer material with an excess transfer resin by maintaining a good coating film thickness distribution. can do.

It is a schematic diagram which shows the coating device which concerns on this Embodiment. It is a schematic diagram which shows the groove | channel carved on the surrounding surface of the gravure roll which concerns on this Embodiment. It is a graph which shows the nano pattern total capacity | capacitance in this Embodiment. It is a graph which shows the nano pattern total capacity | capacitance in this Embodiment. It is a schematic diagram which shows a general gravure roll. It is a schematic diagram which shows an example of the gravure roll in the coating method which concerns on this Embodiment. It is a schematic diagram which shows the other example of the gravure roll in the coating method which concerns on this Embodiment. It is explanatory drawing which shows the relationship between the gravure roll and the scraping member in the coating method which concerns on this Embodiment. It is explanatory drawing which shows the relationship between the gravure roll and the scraping member in the coating method which concerns on this Embodiment. It is explanatory drawing which shows the relationship between the gravure roll and the scraping member in the coating method which concerns on this Embodiment. It is explanatory drawing which shows the relationship between the gravure roll and the scraping member in the coating method which concerns on this Embodiment. It is explanatory drawing which shows the relationship between the gravure roll and the scraping member in the coating method which concerns on this Embodiment. It is explanatory drawing which shows the relationship between the gravure roll and the scraping member in the coating method which concerns on this Embodiment. It is a schematic diagram which shows the coating device which concerns on this Embodiment. It is a correlation diagram of the peripheral speed ratio and the coating weight in the coating method according to the present embodiment. It is a schematic diagram which shows the nanoimprint apparatus using the coating method which concerns on this Embodiment.

  Hereinafter, an embodiment of the present invention (hereinafter abbreviated as “embodiment”) will be described in detail. In addition, this invention is not limited to the following embodiment, It can implement by changing variously within the range of the summary.

  The coating method in the present invention mainly refers to a gravure coating method or a micro gravure coating method. Gravure coating is a coating method that prescribes the coating amount before coating the coating liquid onto the substrate to be transferred, and the coating amount is the amount of liquid lifted from a roll engraved with a plurality of grooves (hereinafter referred to as gravure roll). It is determined by the mechanism for scraping off the excessive coating liquid that has been lifted and the ratio at which the coating liquid in the gravure roll is transferred to the substrate to be transferred, that is, the transfer rate. The coating liquid can be lifted directly or indirectly to the gravure roll, either from a storage member in which the liquid is stored, or from a coating liquid lifting mechanism called an applicator roll.

  FIG. 1 is a schematic diagram showing a coating apparatus according to the present embodiment. As shown in FIG. 1, the coating apparatus 10 includes a housing member 12 that houses a certain amount of coating liquid (liquid transfer resin) 11. A coating liquid supply means 13 for supplying the coating liquid 11 is connected to the housing member 12. The coating liquid supply unit 13 includes a storage tank 13 a in which the coating liquid 11 is stored, and a liquid feeding unit 13 b that sends the coating liquid 11 from the storage tank 13 a to the storage member 12.

  In addition, the coating apparatus 10 includes a gravure roll 14 that is rotatably arranged so that a part of its peripheral surface is immersed in the coating solution 11 stored in the storage member 12. The gravure roll 14 has a plurality of grooves engraved on the peripheral surface. Further, the gravure roll 14 is rotated by a driving means (not shown).

  With such a configuration, when the gravure roll 14 is rotated, the peripheral surface of the gravure roll 14 is immersed in the coating liquid 11, and the coating liquid 11 is transferred to the peripheral surface of the gravure roll 14.

  Further, on the outer side in the circumferential direction of the gravure roll 14, a scraping member 15 that scrapes off the excess coating liquid 11 transferred to the circumferential surface of the gravure roll 14 is provided.

  Further, the film-shaped transfer substrate 16 is configured to run while the surface thereof is in contact with the peripheral surface of the gravure roll 14. As a result, the coating liquid 11 on the peripheral surface of the gravure roll 14 is transferred to the surface of the substrate 16 to be transferred.

  A coating method using the coating apparatus 10 as described above will be described. First, a predetermined amount of the coating liquid 11 is supplied from the storage tank 13a to the containing member 12 by the liquid feeding means 13b (supply process). Next, the coating liquid 11 is transferred onto the peripheral surface of the coating liquid 11 while rotating the gravure roll 14 (first transfer step). Next, the surplus coating liquid 11 transferred to the gravure roll 14 is scraped off by the scraping member 15 (scraping step). Next, the coating liquid 11 is transferred from the gravure roll 14 to the surface of the film-shaped transfer target substrate 16 (second transfer step).

  Here, the gravure roll 14 has an application part that contacts the surface of the substrate 16 to be transferred, a non-application part that is smaller in diameter than the application part and does not contact the surface of the substrate 16 to be transferred, and is scraped off. It is preferable that the member 15 has substantially the same width as the application part of the gravure roll 14.

  Hereinafter, the coating method according to the present embodiment will be described in detail. First, in the supplying step, the certain amount means a height at which the outermost surface liquid surface of the coating liquid 11 supplied to the housing member 12 is in contact with the gravure roll 14. By maintaining a certain amount or more, the coating liquid 11 is continuously transferred to the gravure roll 14 and can be similarly applied to the substrate 16 to be transferred. In addition, the gravure roll 14 is preferably rotated in the reverse direction with respect to the conveyance direction of the substrate 16 to be transferred.

  The reverse rotation of the gravure roll means that the transfer resin that exists between the gravure roll and the substrate to be transferred is pulled from both the gravure roll and the substrate to be transferred. Can be obtained.

  The housing member 12 is not particularly limited, and is a container that is made of a material that is resistant to the coating liquid 11 or that is coated. The volume is not limited in the present invention. The accommodating member 12 should just be arrange | positioned in the position where the lower end of the gravure roll 14 contacts the outermost surface of the coating liquid 11.

  The liquid feeding means 13b is not particularly limited, and a general-purpose pump, that is, a gear pump, a diaphragm pump, a tubing pump, a plunger pump, a bellows pump, a vortex pump, a Heisin Mono pump (registered trademark), or the like is used. Moreover, liquid feeding can also be carried out by pressure feeding with compressed air. Further, compressed air or a motor can be used for driving, and liquid can be fed by a syringe. It is also possible to manually compress the syringe and feed it without using power. The liquid feeding does not need to be continuous, and the liquid may be intermittently fed as long as the uppermost liquid level of the coating liquid 11 touches the lower end of the gravure roll 14.

  FIG. 2 is a schematic diagram showing grooves carved on the peripheral surface of the gravure roll according to the present embodiment. The shape of the groove 21 carved on the peripheral surface of the gravure roll 14 is, for example, (a) pyramid type, (b) lattice type, (c) diagonal line type, and (d), as shown in FIGS. A turtle shell type can be used.

The volume of the groove 21 (hereinafter referred to as the groove volume) is preferably 1 cm ³ / m ² or more and 20 cm ³ / m ² or less. If it is 1 cm ³ / m ² or more, the film thickness is 1 μm or more, assuming that all have transferred to the transfer substrate 16 side. When the transition rate of a general gravure roll is 30%, the film thickness is 300 nm or more, and thus a nano-shaped volume of a mold of 0.3 cm ³ / m ² or more can be transferred. In the case of 1 cm ³ / m ² or less, the stability of the coated surface of the substrate 16 to be transferred is remarkably reduced, and transfer of a mold having a nano-shaped volume of 0.3 cm ³ / m ² or more becomes virtually impossible. . On the other hand, if it is 20 cm ³ / m ² or less, the film thickness is 20 μm or less, assuming that all have been transferred to the transfer substrate 16 side. If the film thickness is 20 μm, almost all of the nano-shapes other than the shape having a very large aspect ratio can be transferred. In addition, since the film is not completely transferred to the transfer base material 16 and the general transfer rate is 30%, the coating film thickness is 6 μm, so that the general nano shape of 6.0 cm ³ / m ² or less is used. The mold can be transferred.

Furthermore, if the groove volume of the gravure roll 14 is 20 cm ³ / m ² or less, it is possible to prevent the excess coating liquid 11 from overflowing in the film width direction of the substrate 16 to be transferred, depending on the nano-shaped volume. it can. In other words, it can be said that the coating liquid 11 can be prevented from overflowing in the film width direction as long as it is plus 6.0 cm ³ / m ² or less with respect to the nano-shaped volume. Preferably, when the coating film thickness t (μm) is a nano-shaped volume plus 6.0 μm or less, overflow in the width direction can be suppressed, and contamination of the mold and the transfer film can be prevented. More preferably, when the coating film thickness t (μm) is a nano-shaped volume plus 3.0 μm or less, overflow in the width direction can be suppressed without depending on the viscosity of the transfer resin.

3 and 4 are graphs showing the total nanopattern capacity in the present embodiment. FIG. 3 shows that the shape of the fine irregularities (nanopattern) of the mold is an elliptical concavity, that is, a hole shape, arranged in a hexagonal lattice, and the filling rate (opening area / fine structure of the hole opening is The total nanopattern capacity (cm ³ / m ² ) of pitches P300 nm, P700 nm, and P1000 nm with respect to the aspect ratio (hole depth (h) / opening diameter (R)) when the plane area when not present is 58% Indicates.

  In addition, FIG. 4 shows a coatable area in the present embodiment derived from FIG. The coatable area that can suppress overflow in the width direction is a region between the solid line portion and the dotted line portion of each structure.

  If it can suppress in the width direction, it can also suppress that a metal mold | die and a to-be-transferred base material are contaminated. However, although the transfer rate will be described later, the diameter of the gravure roll 14, the viscosity of the transfer liquid (transfer resin), the rotation speed Vr of the gravure roll 14 and the transfer speed V2 of the substrate to be transferred, the groove shape of the gravure roll 14, etc. Affected by.

  Next, the coating liquid 11 is transferred onto the peripheral surface of the gravure roll 14 while rotating the gravure roll 14 (first transfer step).

  In the first transfer process, if the amount of the coating liquid 11 transferred to the gravure roll 14 is the lifting amount Q0, the lifting amount Q0 is as shown in the following formula 1.

  In order to reduce the lifting amount Q0 of the gravure roll 14, from Equation 1, the coating solution viscosity μ is decreased, the velocity Vr of the gravure roll 14 is decreased, the cell volume C is decreased, and the roll diameter R of the gravure roll 14 is reduced. Can be reduced. Since the speed Vr of the gravure roll 14 is expressed by the following formula 2, reducing the roll diameter R is effective for reducing the lifting amount.

  That is, by setting the roll diameter R to 30 mm or less, it is possible to reduce the lifting amount Q0 and further reduce the coating amount on the transfer target substrate 16 after the second transfer step of the subsequent step. If the roll diameter is 30 mm or less, it is possible to prevent the excessive coating liquid 11 from overflowing in the film width direction, and it is also possible to suppress contamination of the mold and the substrate to be transferred, which is preferable. Although the number of revolutions can be reduced, if it is reduced to several rpm, pulsation application unevenness due to the drive system, and the motor and the speed reducer may be hindered. Therefore, in the case of thin film coating, it is preferable to make the roll diameter R as small as possible.

  Next, in the first transfer step, surplus coating liquid 11 transferred to the gravure roll 14 is scraped off by the scraping member 15 (scraping step). The scraping member 15 is generally called a blade or a doctor blade, and refers to a thin plate-like or blade-like mechanical component made of metal or resin.

  The material of the blade is not particularly limited, and metal or resin can be selected. In the case of using a resin, it can be selected in consideration of scraping performance, chemical resistance to the transfer resin and the cleaning liquid, and wear resistance with the gravure roll 14.

  As the metal blade, SK (carbon tool steel), SUS (stainless steel), carbon steel, and Velbo (high grade carbon tool steel) can be selected. If the coating solution 11 is an aqueous coating solution, it is preferably made of SUS. Further, it is possible to select a blade that has been subjected to various quenching processes, nickel plating, etc., and has improved wear resistance.

  As the resin blade, for example, polyester, polyethylene, or polyacetal can be selected.

  The shape of the blade is not particularly limited, and a round shape with a rounded blade edge, a bevel type in which the blade edge is flat in a tangential direction with respect to the gravure roll 14, or the like can be selected. The thickness of the blade is not particularly limited. A backup blade can be arranged on the back surface of the blade, that is, on the opposite side of the blade surface in contact with the gravure roll 14. The backup blade serves as both fixing of the blade and suppression and adjustment of bending.

  The method of applying the blade to the gravure roll 14 is not particularly limited, and the gravure roll surface can be applied at the tip of the blade or can be applied in the tangential direction of the roll diameter R of the gravure roll 14 at the flat portion of the blade. Further, the contact angle (also referred to as contact angle) and pressure (also referred to as contact pressure) are not particularly limited. However, as the gravure roll 14 rotates, the ground contact surface of the blade is scraped and may be mixed as a foreign substance in the transfer resin. Therefore, it is necessary to appropriately adjust the contact angle and the contact pressure. For example, when the gravure roll 14 is pressed at the tip of the blade or when the contact pressure is large, the scraping efficiency of excess transfer resin is improved, but the blade surface is easily scraped, so that dust generated by blade wear is transferred. There is a risk of contamination in the resin. On the other hand, when the gravure roll is pressed on the flat portion of the blade or when the contact pressure is small, the scraping efficiency is lowered, but the mixing of dust from the blade into the resin can be suppressed.

  A general hitting angle is selected within a range of 60 ° ± 10 °. However, in the present embodiment, a low angle of 40 ° or less is set in contact with the gravure roll 14 at the flat portion or the round portion of the blade. Selected. Moreover, it is preferable to apply at 40 degrees or less also from a viewpoint of abrasion resistance. However, the contact angle and contact pressure of the blade can be appropriately selected depending on the application developed from the present invention and the applied transfer resin.

  In the coating apparatus 10 according to the present embodiment, the gravure roll 14 has a coating part that contacts the surface of the film-like transferred substrate 16 and a smaller diameter than the coating part, and does not contact the surface of the transferred substrate 16. It has a non-application part. Moreover, it is preferable that the scraping member 15 has substantially the same width as the application part of the gravure roll 14.

  Here, the scraping member 15 having substantially the same width as the application part of the gravure roll 14 means that the width of the coating liquid 11 transferred to the groove part of the gravure roll 14 and the width of the scraping member 15 are the same. It points to something.

  A normal gravure roll has a certain groove engraved on a solid roll. The width of the engraved groove in the cylindrical direction becomes the transition width in the first transition step and the transition width in the second transition step, that is, the coating width.

  FIG. 5 is a schematic view showing a general gravure roll. As shown in FIG. 5, when the diameter of the portion 50a in which the groove portion of the gravure roll 50 is engraved is R1, the diameter of the portion 50b in which the groove portion is not engraved is also R1. At this time, the portion 50b in which the groove portion is not engraved should not transfer the coating liquid originally, but the surface of the solid gravure roll 50 has a surface roughness of a certain level or more. Metastasize. Even in the case of scraping, the coating liquid present in the groove portion of the rough surface remains without being scraped off due to the surface roughness, and is transferred to the transfer substrate by the second transfer step.

  Therefore, in the present embodiment, the outermost surface of the coating liquid 11 accommodated in the accommodating member 12 is not contacted in the first transfer step, or the surface of the transfer substrate 16 is not contacted in the second transfer step. In order to avoid this, the gravure roll 14 is provided with a non-contact portion.

  FIG. 6 is a schematic diagram showing an example of a gravure roll in the coating method according to the present embodiment. As shown in FIG. 6, the non-application part 14b which has the diameter R2 smaller than the diameter R1 of the application part 14a of the gravure roll 14 is provided.

  FIG. 7 is a schematic diagram showing another example of the gravure roll in the coating method according to the present embodiment. As shown in FIG. 7, the application portion 70 a is divided and the plurality of non-application portions 70 b are provided on the same gravure roll 70, thereby applying the application to the transfer substrate 16 in a plurality of regions. Can do.

  As described above, by making the width of the coating portion 14a of the gravure roll 14 and the width of the scraping member 15, that is, the blade substantially the same, the coating liquid 11 is uniformly distributed in the width direction of the substrate 16 to be transferred. Can be applied.

FIG. 8 is an explanatory diagram showing the relationship between the gravure roll and the scraping member in the coating apparatus according to the present embodiment. “The scraping member 15 has substantially the same width as the application portion 14a of the gravure roll 14” means that the width (also referred to as application width) of the application portion 14a of the gravure roll 14 (W1) as shown in FIG. ) And the width (W2) of the scraping member 15 is represented by the following formula 3. In addition, when providing the some application part 70a as shown in FIG. 7, following formula 3 is applied about the width | variety of one application part 70a. That is, when providing the some application part 70a, following formula 3 is applied to the width | variety of each application part 70a instead of the sum total of the width | variety of the application part 70b.
Formula 3 W1 ≦ W2 ≦ (W1 × 1.02)
(W1 satisfies W1 ≦ 1000 mm)
W1: Width of the application part (width of the gravure roll 14 having a diameter R1 in the cylindrical direction)
W2: Width of scraping member (blade width)

  In the present embodiment, it is assumed that the application width (W1) of the gravure roll 14 and the width (W2) of the scraping member 15 are always facing each other and are not shifted from each other. As shown in FIG. 9, the positions of the application width (W1) of the gravure roll 14 and the width (W2) of the scraping member 15 are shifted. Part) is transferred to the transfer target substrate 16 in the second transfer step without being scraped off by the scraping member 15, so that the excess coating liquid 11 is applied. Become. The surplus coating liquid 11 not only causes unevenness of the coating film thickness, but also overflows during transfer with the mold, contaminates the substrate 16 and the mold to be transferred, and the film thickness after transfer is different. The physical properties may not be obtained.

  As shown in FIG. 10, when W1> W2, since the width (W1) of the application part 14a of the gravure roll 14 is larger than the width (W2) of the scraping member 15, there is an area that is not scraped by the scraping member 15. Occur. Therefore, in the second transfer step, transfer to the transfer substrate 16 is performed, so that the excess coating liquid 11 is applied. The surplus coating liquid 11 not only causes unevenness of the coating film thickness, but also overflows during transfer with the mold, contaminates the substrate 16 and the mold to be transferred, and the film thickness after transfer is different. Some physical properties may not be obtained.

  On the other hand, as shown in FIGS. 11 and 12, when (W1 × 1.02) <W2 and when W1 ≧ 1000 mm, the width of the blade 15 is considerably larger than the width of the coating portion, so When pressing the application part 14a of the roll 14, the pressing force of the blade 15 is concentrated on the small-diameter processed corner 14c of the application part 14a instead of the flat surface of the application part 14a, and the blade 15 appears to be bent. Since the flat part of the application part 14a of the gravure roll 14 and the blade 15 do not contact uniformly, the scraping efficiency of the flat part of the application part 14a decreases.

  Further, when W1 ≧ 1000 mm, it is substantially difficult to achieve the mounting accuracy and manufacturing accuracy of the blade 15.

  If W1 ≦ W2 ≦ (W1 × 1.02) and W1 ≦ 1000 mm, the gravure roll 14 can be applied without the pressure of the blade 15 being concentrated on the small-diameter processed corner 14c of the application portion 14a. Since the uniform blade hits the plane of the portion 14a and can be pressed, it can be uniformly applied to the substrate 16 to be transferred.

  Further, in order to uniformly press the blade 15, it is preferable to suppress the bending of the blade 15. The amount of deflection of the blade 15 having a width corresponding to W1 is expressed by the following formula 4. FIG. 13 is an explanatory diagram showing the relationship between the gravure roll and the scraping member in the coating apparatus according to the present embodiment. FIG. 13 shows symbols used in the following formula 4.

  In order to reduce the deflection amount σAB of the blade 15, it is most simple and preferable to reduce the values of a and b as shown in Equation 4. The sum of a and b corresponds to W2−W1 in the range of W1 ≦ W2 ≦ (W1 × 1.02). Further, it is also preferable to reduce l, and l corresponds to W1, so that bending of the blade 15 can be sufficiently suppressed as long as l is within a range of W1 ≦ 1000 mm. In addition, increasing the elastic modulus of the blade 15 and increasing the thickness of the blade 15 are effective in suppressing the amount of bending. However, when the elastic modulus of the blade 15 is increased, the fine shape of the gravure roll 14 may be destroyed due to its hardness. When the thickness of the blade 15 is increased, bending in the width direction can be suppressed. Since the bending of the directional blade 15 is reduced, the amount of the transfer resin in the first transfer process is reduced or disturbed. When a SK product (200 GPa) is used as a general blade material, the thickness is preferably 0.3 mm or less. If it is 0.3 mm or less, the bending in the width direction can be suppressed while securing the bending in the vertical direction.

  The amount of deflection in the width direction of the blade 15 is preferably 0 to 1.5 mm, more preferably 0 to 1.0 mm, from Equation 4. If it is 0-1.5 mm, since it can apply | coat without application | coating unevenness, the transfer defect at the time of transcription | transfer can be suppressed. If it is 0-1.0 mm, while being able to suppress an application | coating nonuniformity, mixing of the foreign material accompanying abrasion of the gravure roll 14 or the braid | blade 15 can be prevented.

  However, as the blade width increases, the amount of deflection increases accordingly, so it is preferable to increase the blade thickness and suppress the amount of deflection derived from Equation 4.

  In the second transfer step, the coating liquid 11 transferred to the groove portion of the gravure roll 14 in the first transfer step is transferred to the surface of the substrate 16 to be transferred.

  If the coating liquid 11 existing in the groove portion of the gravure roll 14, that is, the transfer resin has all transferred to the transfer target substrate 16, the transfer amount Qf is expressed by the following formula 5. FIG. 14 is a schematic diagram showing a coating apparatus according to the present embodiment. FIG. 14 shows symbols used in the following formula 5.

  However, Expression 5 is established when S <1. When S> 1, Equation 6 is obtained.

  In order to reduce the transfer amount Qf transferred to the substrate, from Equation 4, the traveling speed Vf is increased, the roll speed Vr is decreased, the roll diameter R is decreased, and the coating liquid volume (h1, Q1) in the cell portion ). Lowering the volume of the coating liquid in the cell portion can be achieved by lowering the lift amount Q0 and increasing the amount of scraping off the lifted coating liquid 11.

  The rotational speed Vr of the roll is given by the following formula 7.

  In general, the ratio (Vr / Vf) between the rotational speed Vr of the roll and the running speed Vf of the base material is called a peripheral speed ratio, and the smaller the value, the more the transfer amount Qf can be reduced. FIG. 15 is a correlation diagram between the peripheral speed ratio and the coating weight in the coating method according to the present embodiment. As shown in FIG. 15, when the peripheral speed ratio is from 0.6 to 2.0, the coating weight, that is, the film thickness increases proportionally, but when the peripheral speed ratio is 2.0 or more, the substrate There is a tendency to decline without metastasis to the side. In addition, when the peripheral speed ratio is 0.6 or less, it cannot be applied uniformly.

  However, in precision thin film coating in nanoimprinting, a film thickness of several micrometers or less is required, and in the present invention, it was found that uniform coating can be performed even when the peripheral speed ratio is 0.10 or more and 0.50 or less. The peripheral speed ratio is preferably 0.10 or more and 0.50 or less, and more preferably 0.10 or more and 0.20 or less. If the peripheral speed ratio is 0.10 or more and 0.50 or less, uniform thin film coating can be obtained, and resin contamination on the substrate and roll after transfer can be reduced. Moreover, if the peripheral speed ratio is 0.10 or more and 0.20 or less, it does not depend on the viscosity of the transfer resin, and even if the viscosity is low, resin contamination to the base material and roll after transfer can be reduced. it can. However, when the peripheral speed ratio is 0.10 or less, it is difficult to obtain a uniform coating film surface regardless of the viscosity of the transfer resin and the running speed Vf. When the peripheral speed ratio is 0.10 or less, or when there are bubbles on the coating film surface and the coating film surface is rough, poor filling during nanoimprinting or turbulent flow of the resin pool that occurs immediately before transfer occurs, and transfer curing occurs. It becomes a factor of the fall of the physical property later.

  In the present embodiment, in order to achieve the above-described peripheral speed ratio and obtain a uniform thin film coated surface, it is preferable to reduce the traveling speed Vf of the substrate 16 to be transferred. The traveling speed Vf is preferably set to 3.0 m / min or less, and if the traveling speed Vf is 3.0 m / min or less, the coating can be applied even at the above peripheral speed ratio. Further, the traveling speed Vf is more preferably 1.0 m / min or less. If the traveling speed Vf is 1.0 m / min or less, it does not depend on the viscosity of the transfer resin, and the peripheral speed ratio is 0.2 or less. It can apply | coat and can reduce the resin contamination to the base material and roll after transcription | transfer.

  Further, the coating liquid 11 present in the groove portion of the gravure roll 14 does not completely transfer to the transferred substrate 16 side, and the transfer rate is said to be approximately 30% based on experience and experiments so far. This is because, due to the shape of the engraved groove, the viscosity of the coating liquid 11, the roll speed, and the like, the transfer resin is transferred to the transfer target substrate 16 and the transfer resin that remains in the groove without being transferred. It is.

  The coating liquid 11 corresponds to the transfer resin in the present invention. In order to prevent resin overflow due to pressing during nanoimprinting, it is necessary to reduce the transfer amount of the transfer resin to the substrate to be transferred.

  First, in order to reduce the transfer amount of the transfer resin, it is preferable to lower the viscosity of the coating solution from Equations 1 and 3. Lowering the viscosity of the transfer resin is preferable from the viewpoint of ease of filling the nanostructure during nanoimprinting in addition to thin film coating. The viscosity of the transfer resin is preferably 200 mPa · s or less, and more preferably 100 mPa · s or less. If it is 200 mPa * s or less, the several-micrometer-thickness application | coating can be achieved in the gravure coating of this invention. If it is 100 mPa · s or less, a thin film can be applied, and the filling speed into the nanostructure is improved, so that the tact time can be shortened. Since the viscosity is a viscosity at the time of application, the viscosity can be lowered by heating the transfer resin. The heating temperature is not particularly limited, but is preferably determined within a range where the transfer resin is cured by heat and does not affect the nanoimprint.

  Moreover, the viscosity at the time of application | coating can be lowered | hung by adding a solvent to transfer resin. By adding a solvent, the film thickness after drying can be further reduced. However, the addition of a solvent may cause insufficient transfer or decrease in physical properties after transfer because drying may be insufficient or the solvent may remain in the transfer resin during nanoimprinting. Moreover, when the viscosity of the transfer resin after drying is higher, the thinner the film is, the more insufficient the filling during nanoimprinting. The thinner the film, the more affected by the substrate, so that the fluidity of the transfer resin is lost and the nanostructure is insufficiently filled.

(Transfer substrate)
As the substrate 16 to be transferred, a film-like substrate having optical transparency can be used.

  The film-like substrate is not particularly limited as long as it is mainly composed of a material that has a substantially light-transmitting property with respect to a light source used in the ultraviolet / visible light region, but has excellent handling properties and workability. A resin material is preferable. Examples of such resin materials include polymethyl methacrylate resin, polycarbonate resin, polystyrene resin, cycloolefin resin (COP), cross-linked polyethylene resin, polyvinyl chloride resin, polyarylate resin, polyphenylene ether resin, and modified polyphenylene ether resin. , Polyetherimide resin, polyether sulfone resin, polysulfone resin, polyether ketone resin, amorphous thermoplastic resin such as triacetyl cellulose (TAC) resin, polyethylene terephthalate (PET) resin, polyethylene naphthalate resin And crystalline thermoplastic resins such as polyethylene resin, polypropylene resin, polybutylene terephthalate resin, aromatic polyester resin, polyacetal resin, and polyamide resin.

  The film-like substrate is preferably film-like in order to be applied to the roll-to-roll method.

  Although the thickness of a film-like base material is based also on material, Preferably it is 20-200 micrometers, More preferably, it is 50-150 micrometers, More preferably, it is 50-100 micrometers. If it is 200 micrometers or less, the transmittance | permeability of the ultraviolet-ray used for the light source of optical nanoimprint is favorable, and sufficient light quantity for photocuring can be obtained. If it is 20 micrometers, since the rigidity as a film can be hold | maintained, handling is easy.

  The surface of the film-like substrate can be subjected to primer treatment, atmospheric pressure plasma treatment, or corona treatment in order to improve adhesion with the transfer resin.

  The nanoimprint apparatus according to the present embodiment is an apparatus that irradiates the transfer resin layer with light in a state where the transfer resin is in close contact with the mold, or photocures the heated transfer resin in close contact with the mold, and is separated after cooling. An apparatus that molds and heats a transfer resin in close contact with a mold and releases the mold to obtain a nano shape is assumed. For this reason, although depending on the transfer resin used, in the case of photocuring, the film-like substrate is required to have good light transmittance in the wavelength range of 200 nm to 500 nm. Depending on the photosensitivity of the transfer resin used, the specific transmittance value is not particularly limited in the wavelength range of 200 nm to 500 nm, but if the 365 nm, 405 nm and total light transmittance are good, the transfer resin This is preferable because it is sufficiently photocured. Moreover, if the transmittance in the wavelength range of 200 nm to 500 nm is good, the light irradiation energy required for curing the transfer resin can be reduced, and the transfer can be speeded up.

(Transfer resin)
The transfer resin is selected in consideration of transferability, releasability from a mold, adhesion to a substrate to be transferred, viscosity, film-forming properties, photosensitivity, and mechanical properties after curing.

  As the transfer resin according to the present embodiment, a thermosetting resin, a thermoplastic resin, or a photocurable resin can be used, preferably a thermoplastic resin and a photocurable resin, and more preferably a photocurable resin. is there.

  Examples of the photocurable resin include various acrylate compounds and methacrylate compounds, epoxy compounds, isocyanate compounds, thiol compounds, and silicones that can be polymerized with a photopolymerization initiator, a photoacid generator, or a photobase generator. Compounds and the like can be used. Among these, acrylate compounds, methacrylate compounds, epoxy compounds, and silicone compounds are preferably used, and acrylate compounds and methacrylate compounds are more preferably used. These compounds may be used alone or in combination of a plurality of types such as a combination of an epoxy compound and an acrylate compound. Similarly, the photopolymerization initiator, photoacid generator, and photobase generator may be used singly or in combination of two or more.

  As acrylate compounds and methacrylate compounds, aromatic (meth) acrylates such as (meth) acrylic acid, phenoxyethyl acrylate, and benzyl acrylate, stearyl acrylate, lauryl acrylate, 2-ethylhexyl acrylate, allyl acrylate, 1,3- Hydrocarbon (meth) such as butanediol diacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, trimethylolpropane triacrylate, pentaaerythritol triacrylate, and dipentaerythritol hexaacrylate Acrylate, ethoxyethyl acrylate, methoxyethyl acrylate, glycidyl acrylate, tetrahydrofurfryl acrylate, diethylene Hydrocarbon (meth) acrylates containing etheric oxygen atoms such as recall diacrylate, neopentyl glycol diacrylate, polyoxyethylene glycol diacrylate, and tripropylene glycol diacrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl Hydrocarbon-based (meth) acrylates containing functional groups such as acrylate, 4-hydroxybutyl vinyl ether, N, N-diethylaminoethyl acrylate, N, N-dimethylaminoethyl acrylate, N-vinylpyrrolidone, and dimethylaminoethyl methacrylate, Examples include silicone-based acrylates.

  Examples of the acrylate compound and the methacrylate compound include EO-modified glycerol tri (meth) acrylate, ECH-modified glycerol tri (meth) acrylate, PO-modified glycerol tri (meth) acrylate, pentaerythritol triacrylate, EO-modified phosphate triacrylate, tri Methylolpropane tri (meth) acrylate, caprolactone-modified trimethylolpropane tri (meth) acrylate, PO-modified trimethylolpropane tri (meth) acrylate, tris (acryloxyethyl) isocyanurate, EO-modified trimethylolpropane tri (meth) acrylate, Dipentaerythritol hexa (meth) acrylate, caprolactone-modified dipentaerythritol hexa (meth) acrylate, dipenta Lithritol hydroxypenta (meth) acrylate, alkyl-modified dipentaerythritol penta (meth) acrylate, dipentaerythritol poly (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, alkyl-modified dipentaerythritol tri (meth) acrylate, penta Erythritol ethoxytetra (meth) acrylate, pentaerythritol tetra (meth) acrylate, diethylene glycol monoethyl ether (meth) acrylate, dimethylol dicyclopentane di (meth) acrylate, di (meth) acrylated isocyanurate, 1,3-butylene Glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, EO-modified 1,6-hexanediol di (meth) Acrylate, ECH modified 1,6-hexanediol di (meth) acrylate, allyloxy polyethylene glycol acrylate, 1,9-nonanediol di (meth) acrylate, EO modified bisphenol A di (meth) acrylate, PO modified bisphenol A di ( (Meth) acrylate, modified bisphenol A di (meth) acrylate, EO modified bisphenol F di (meth) acrylate, ECH modified hexahydrophthalic acid diacrylate, neopentyl glycol di (meth) acrylate, hydroxypivalate neopentyl glycol di (meta) ) Acrylate, EO modified neopentyl glycol diacrylate, PO modified neopentyl glycol diacrylate, caprolactone modified hydroxypivalate ester neopentylglycol Stearic acid modified pentaerythritol di (meth) acrylate, ECH modified propylene glycol di (meth) acrylate, ECH modified phthalic acid di (meth) acrylate, poly (ethylene glycol-tetramethylene glycol) di (meth) acrylate, poly ( Propylene glycol-tetramethylene glycol) di (meth) acrylate, polypropylene glycol di (meth) acrylate, silicone di (meth) acrylate, tetraethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, polyester (di) Acrylate, polyethylene glycol di (meth) acrylate, dimethylol tricyclodecane di (meth) acrylate, neopentyl glycol modified trimethylol propylene Di (meth) acrylate, dipropylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, triglycerol di (meth) acrylate, EO-modified tripropylene glycol di (meth) acrylate, divinylethylene urea, divinylpropylene urea 2-ethyl-2-butylpropanediol acrylate, 2-ethylhexyl (meth) acrylate, 2-ethylhexyl carbitol (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2- Hydroxybutyl (meth) acrylate, 2-methoxyethyl (meth) acrylate, 3-methoxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, acrylic acid Immer, benzyl (meth) acrylate, butanediol mono (meth) acrylate, butoxyethyl (meth) acrylate, butyl (meth) acrylate, cetyl (meth) acrylate, EO-modified cresol (meth) acrylate, ethoxylated phenyl (meth) acrylate , Ethyl (meth) acrylate, dipropylene glycol (meth) acrylate, isoamyl (meth) acrylate, isobutyl (meth) acrylate, isooctyl (meth) acrylate, cyclohexyl (meth) acrylate, dicyclopentanyl (meth) acrylate, isobornyl ( (Meth) acrylate, dicyclopentanyloxyethyl (meth) acrylate, isomyristyl (meth) acrylate, lauryl (meth) acrylate, methoxydipropyle Glycol (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, methoxytriethylene glycol (meth) acrylate, methyl (meth) acrylate, methoxytripropylene glycol (meth) acrylate, neopentyl glycol benzoate (meth) acrylate, nonylphenoxy Polyethylene glycol (meth) acrylate, nonylphenoxy polypropylene glycol (meth) acrylate, octyl (meth) acrylate, paracumylphenoxyethylene glycol (meth) acrylate, ECH modified phenoxy acrylate, phenoxydiethylene glycol (meth) acrylate, phenoxyhexaethylene glycol (meta ) Acrylate, phenoxytetraethylene glycol ( Acrylate), phenoxyethyl (meth) acrylate, polyethylene glycol (meth) acrylate, polyethylene glycol-polypropylene glycol (meth) acrylate, polypropylene glycol (meth) acrylate, stearyl (meth) acrylate, EO-modified succinic acid (meth) acrylate, Examples include tert-butyl (meth) acrylate, tribromophenyl (meth) acrylate, EO-modified tribromophenyl (meth) acrylate, tridodecyl (meth) acrylate, and silicone-based acrylate compounds. Here, EO modification means ethylene oxide modification, ECH modification means epichlorohydrin modification, and PO modification means propylene oxide modification. These can be used alone or in combination of two or more. In addition, commercially available resins for nanoimprinting such as PAK series (manufactured by Toagosei Co., Ltd.), NIF series (manufactured by AGC Co., Ltd.), NIAC series (manufactured by Daicel Chemical Industries, Ltd.) and the like can be used. Among these, PAK-02 and NIAC-702 are particularly preferable from the viewpoint of application characteristics to a resin sheet and pattern transferability.

  Moreover, as a photocurable resin, the fluorine-containing compound by which the hydrogen in hydrocarbon was substituted by the fluorine among the said acrylate compound, a methacrylate compound, an epoxy compound, an isocyanate compound, and a silicone type compound can be used. By using the fluorine-containing compound, the surface free energy after curing is reduced, and the releasability of the transferred product from the original (cylindrical mold) in the transfer process is improved.

  The fluorine-containing (meth) acrylate preferably has a polyfluoroalkylene chain and / or a perfluoro (polyoxyalkylene) chain and a polymerizable group, and is a linear perfluoroalkylene group or a carbon atom-carbon atom. More preferred is a perfluorooxyalkylene group having an etheric oxygen atom inserted therein and having a trifluoromethyl group in the side chain. Further, a linear polyfluoroalkylene chain having a trifluoromethyl group at the molecular side chain or molecular structure terminal and / or a linear perfluoro (polyoxyalkylene) chain is particularly preferred.

  The polyfluoroalkylene chain is preferably a polyfluoroalkylene group having 2 to 24 carbon atoms. Moreover, the polyfluoroalkylene group may have a functional group.

The perfluoro (polyoxyalkylene) chain is a group consisting of (CF ₂ CF ₂ O) units, (CF ₂ CF (CF ₃ ) O) units, (CF ₂ CF ₂ CF ₂ O) units and (CF ₂ O) units. It is preferably composed of one or more perfluoro (oxyalkylene) units selected from: (CF ₂ CF ₂ O) units, (CF ₂ CF (CF ₃ ) O) units, or (CF ₂ CF ₂ CF ₂ O). ) Units. The perfluoro (polyoxyalkylene) chain is particularly preferably composed of (CF ₂ CF ₂ O) units because the physical properties (heat resistance, acid resistance, etc.) of the fluoropolymer are excellent. The number of perfluoro (oxyalkylene) units is preferably an integer of 2 to 200, more preferably an integer of 2 to 50, because the release property and hardness of the fluoropolymer are high.

The polymerizable group is represented by a vinyl group, an allyl group, an acryloyl group, a methacryloyl group, an epoxy group, a dichitacene group, a cyano group, an isocyanate group, or a formula — (CH ₂ ) aSi (M1) _3-b (M2) _b. A hydrolyzable silyl group is preferable, and an acryloyl group or a methacryloyl group is more preferable. Here, M1 is a substituent which is converted into a hydroxyl group by a hydrolysis reaction. Examples of such a substituent include a halogen atom, an alkoxy group, and an acyloxy group. As the halogen atom, a chlorine atom is preferable. As an alkoxy group, a methoxy group or an ethoxy group is preferable, and a methoxy group is more preferable. As M1, an alkoxy group is preferable, and a methoxy group is more preferable. M2 is a monovalent hydrocarbon group. Examples of M2 include an alkyl group, an alkyl group substituted with one or more aryl groups, an alkenyl group, an alkynyl group, a cycloalkyl group, and an aryl group, and an alkyl group or an alkenyl group is preferable. When M2 is an alkyl group, an alkyl group having 1 to 4 carbon atoms is preferable, and a methyl group or an ethyl group is more preferable. When M2 is an alkenyl group, an alkenyl group having 2 to 4 carbon atoms is preferable, and a vinyl group or an allyl group is more preferable. a is an integer of 1 to 3, and 3 is preferable. b is 0 or an integer of 1 to 3, and 0 is preferable. Examples of the hydrolyzable silyl group include (CH ₃ O) ₃ SiCH ₂ —, (CH ₃ CH ₂ O) ₃ SiCH ₂ —, (CH ₃ O) ₃ Si (CH ₂ ) ₃ — or (CH ₃ CH ₂ O ) ₃ Si (CH ₂ ) ₃ — is preferred.

  The number of polymerizable groups is preferably an integer of 1 to 6 and more preferably an integer of 1 to 4 because of excellent polymerizability. When using 2 or more types of compounds, as for the average number of polymeric groups, 1-3 are preferable.

  If the fluorine-containing (meth) acrylate has a functional group, the adhesiveness with the film-like substrate is excellent. Examples of the functional group include a carboxyl group, a sulfonic acid group, a functional group having an ester bond, a functional group having an amide bond, a hydroxyl group, an amino group, a cyano group, a urethane group, an isocyanate group, and a functional group having an isocyanuric acid derivative. It is done. In particular, it preferably contains at least one functional group having a carboxyl group, a urethane group, or an isocyanuric acid derivative. The isocyanuric acid derivatives include those having an isocyanuric acid skeleton and a structure in which at least one hydrogen atom bonded to a nitrogen atom is substituted with another group. As the fluorine-containing (meth) acrylate, fluoro (meth) acrylate, fluorodiene, or the like can be used.

  The photocurable resin preferably contains a photopolymerization initiator in order to improve photosensitivity. Examples of the photopolymerization initiator include a photoradical polymerization initiator, a photoacid generator, and a photobase generator. The photopolymerization initiator can be selected in consideration of the light source wavelength to be used, the substrate (transparent sheet), various physical properties, and the like. Examples of the photopolymerization initiator include benzophenone, methyl o-benzoylbenzoate, 4-benzoyl-4′-methyldiphenyl ketone, dibenzyl ketone, fluorenone, 2,2′-diethoxyacetophenone, 2-hydroxy-2- Methylpropiophenone, 2,2-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropane- 1-one, 2-hydroxy-1- {4- [4- (2-hydroxy-2-methylpropionyl) -benzyl] -phenyl} -2-methylpropan-1-one, methyl phenylglyoxylate, thioxanthone, 2 -Methylthioxanthone, 2-isopropylthioxanthone, diethylthioxyl Benzyl, benzyldimethyl ketal, benzyl-β-methoxyethyl acetal, benzoin, benzoin methyl ether, 2-hydroxy-2-methyl-1phenylpropan-1-one, 1-phenyl-1,2-butanedione-2- (O-methoxycarbonyl) oxime, 1-phenyl-1,2-propanedione-2- (O-methoxycarbonyl) oxime, 1-phenyl-1,2-propanedione-2- (O-ethoxycarbonyl) oxime, 1-phenyl-1,2-propanedione-2- (O-benzoyl) oxime, 1,3-diphenylpropanetrione-2- (O-ethoxycarbonyl) oxime, 1-phenyl-3-ethoxypropanetrione-2- (O-benzoyl) oxime, 1,2-octanedione, 1- [4 -(Phenylthio)-, 2- (O-benzoyloxime)], ethanone, 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl]-, 1- (O-acetyl) Oxime), 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1- [4- (2-hydroxyethoxy) phenyl] -2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-1- {4- [4- (2-hydroxy-2-methylpropionyl) -benzyl] phenyl} -2-methylpropane, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) ) -Butanone-1,2-dimethylamino-2- (4-methylbenzyl) -1- (4-morpholin-4-yl-phenyl) butan-1-one, bis (2,4,6- Limethylbenzoyl) -phenylphosphine oxide, bis (2,6-dimethoxybenzoyl) -2,4,4-trimethyl-pentylphosphine oxide, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, bis ( η5-2,4-cyclopentadien-1-yl) -bis (2,6-difluoro-3- (1H-pyrrol-1-yl) phenyl) titanium and the like are preferable. These may be used alone or in combination as a mixture. Examples of commercially available initiators include “Irgacure®” manufactured by BASF (eg, Irgacure 651, 184, 500, 2959, 127, 754, 907, 369, 379, 379EG, 819, 1800, 784). , OXE01, OXE02), “Darocur (registered trademark)” (for example, Darocur 1173, MBF, TPO, 4265) and the like.

  As a photocurable resin, what contains a sensitizer for a photosensitivity improvement is preferable. Examples of such a sensitizer include Michler's ketone, 4,4′-bis (diethylamino) benzophenone, 2,5-bis (4′-diethylaminobenzylidene) cyclopentanone, and 2,6-bis (4′-diethylamino). Benzylidene) cyclohexanone, 2,6-bis (4′-dimethylaminobenzylidene) -4-methylcyclohexanone, 2,6-bis (4′-diethylaminobenzylidene) -4-methylcyclohexanone, 4,4′-bis (dimethylamino) ) Chalcone, 4,4′-bis (diethylamino) chalcone, 2- (4′-dimethylaminocinnamylidene) indanone, 2- (4′-dimethylaminobenzylidene) indanone, 2- (p-4′-dimethylamino) Biphenyl) benzothiazole, 1,3-bis (4-dimethyla) Nobenzylidene) acetone, 1,3-bis (4-diethylaminobenzylidene) acetone, 3,3′-carbonyl-bis (7-diethylaminocoumarin), 3-acetyl-7-dimethylaminocoumarin, 3-ethoxycarbonyl-7- Dimethylaminocoumarin, 3-benzyloxycarbonyl-7-dimethylaminocoumarin, 3-methoxycarbonyl-7-diethylaminocoumarin, 3-ethoxycarbonyl-7-diethylaminocoumarin, N-phenyl-N-ethylethanolamine, N-phenyldiethanolamine , Np-tolyldiethanolamine, N-phenylethanolamine, N, N-bis (2-hydroxyethyl) aniline, 4-morpholinobenzophenone, isoamyl 4-dimethylaminobenzoate, 4-diethylamino Isoamyl benzoate, benztriazole, 2-mercaptobenzimidazole, 1-phenyl-5-mercapto-1,2,3,4-tetrazole, 1-cyclohexyl-5-mercapto-1,2,3,4-tetrazole, 1- (tert-butyl) -5-mercapto-1,2,3,4-tetrazole, 2-mercaptobenzothiazole, 2- (p-dimethylaminostyryl) benzoxazole, 2- (p-dimethylaminostyryl) Examples thereof include benzthiazole, 2- (p-dimethylaminostyryl) naphtho (1,2-p) thiazole, 2- (p-dimethylaminobenzoyl) styrene and the like. Moreover, a sensitizer may be used individually by 1 type and may use multiple types as a mixture.

  The viscosity of the photocurable resin can be adjusted by adding a solvent. As the solvent, N, N-dimethylformamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-vinyl-2-pyrrolidone, N, N-dimethylacetamide, dimethyl sulfoxide, hexamethylphosphoramide Pyridine, cyclopentanone, γ-butyrolactone, α-acetyl-γ-butyrolactone, tetramethylurea, 1,3-dimethyl-2-imidazolinone, N-cyclohexyl-2-pyrrolidone, propylene glycol monomethyl ether, propylene glycol monomethyl Ether acetate, acetone, methyl ethyl ketone, methyl isobutyl ketone, anisole, ethyl acetate, ethyl lactate, butyl lactate, methanol, ethanol, isopropyl alcohol and the like are preferable. These solvents may be used alone or in combination of two or more. Among these solvents, N-vinyl-2-pyrrolidone, N-methyl-2-pyrrolidone, acetone, methyl ethyl ketone and isopropyl alcohol are preferable. These solvents can be appropriately added according to the coating method, coating film thickness and viscosity of the photocurable resin, and are not limited. For example, the solvent is added to 100 parts by weight of the curable resin. 1 part by weight to 10000 parts by weight can be added.

  Various additives can be added to the photocurable resin. Antioxidants and flame retardants for ensuring the weather resistance after transfer, various surfactants for improving surface properties such as slipperiness and peelability, and other binders for controlling film formability and hardness after transfer A polymer or the like can be added as appropriate. These may be photoreactive or non-photoreactive.

  The transfer resin can be cured by, for example, photocuring, thermal curing, curing with an electron beam, and microwave. Among these, it is preferable to use photocuring. After the photocurable resin is applied to the substrate to be transferred by the above application method, the photocurable resin can be accelerated by irradiating the photocurable resin with an arbitrary amount of light at a predetermined wavelength. .

(Nanoimprinting device)
An outline of the nanoimprint apparatus according to the present embodiment will be briefly described. FIG. 16 is a schematic diagram showing a nanoimprint apparatus using the coating apparatus according to the present embodiment.

  As shown in FIG. 16, the nanoimprint apparatus 100 includes a raw roll 101 around which a transfer target substrate 16 is wound, and a take-up roll 102 that winds up a transfer film 110 that is nanoimprinted using the transfer target substrate 16. With. Between the original roll 101 and the take-up roll 102, a coating apparatus 10 that applies a transfer resin onto the transfer substrate 16 from the upstream side to the downstream side in the transport direction of the transfer substrate 16; A cylindrical mold 104 having a fine concavo-convex structure on the outer peripheral surface, a pressurizing means 105 for bringing the transfer resin on the substrate 16 to be transferred and the outer peripheral surface of the cylindrical mold 104 into close contact, and the cylindrical mold 104 A light source 106 for irradiating light onto the transfer resin on the substrate 16 to be transferred, which is in close contact with the outer peripheral surface, is provided in this order. In addition, when apply | coating transfer resin using a solvent, you may use the transfer apparatus further provided with the drying furnace 107 which dries the solvent in transfer resin.

  Since the present invention specializes in the coating apparatus 10 in the nanoimprint apparatus 100, the configuration of the nanoimprint apparatus 100 is not particularly limited.

(light source)
When using photocurable resin as transfer resin, it does not restrict | limit especially as the light source 106 used for the light irradiation to photocurable resin, A various light source can be used according to a use and an installation. For example, a high pressure mercury lamp, a low pressure mercury lamp, an electrodeless lamp, a metal halide lamp, an excimer lamp, an LED lamp, a xenon pulse ultraviolet lamp, or the like can be used. Further, photocurable resins can amount exposed to ultraviolet rays or visible light having a wavelength 200nm~500nm is cured by irradiation so as to ^{100mJ / cm 2 ~2000mJ / cm 2} . Further, from the viewpoint of preventing the inhibition of the photocuring reaction due to oxygen, it is desirable to irradiate light with a low oxygen concentration during light irradiation.

(Mold)
The mold in the nanoimprint apparatus 100 is preferably a cylindrical mold from the viewpoint of continuous productivity and yield. The cylindrical mold is more preferably seamless. If there is a seam, the final product with a fine relief structure will be cut off where there is no fine relief structure corresponding to the seam, which will not only reduce the yield, but will add extra work for continuous production. Sexuality also deteriorates.

  As the cylindrical mold, a cylindrical mold having a fine uneven structure on the outer peripheral surface is used. The fine uneven structure corresponds to the shape of the fine uneven structure of the product with the fine uneven structure to be manufactured.

  The fine concavo-convex structure of the cylindrical mold is formed by a laser cutting method, an electron beam drawing method, a photolithography method, a direct drawing lithography method using a semiconductor laser, an interference exposure method, an electroforming method, an anodizing method, or the like. It can form directly on the outer peripheral surface of a cylindrical base material. Among these, from the viewpoint of obtaining a cylindrical mold that is seamless in the fine concavo-convex structure, a photolithography method, a direct drawing lithography method using a semiconductor laser, an interference exposure method, an electroforming method, and an anodic oxidation method are preferable. A direct drawing lithography method, an interference exposure method, and an anodic oxidation method are more preferable.

  In addition, as the cylindrical mold, the fine structure formed on the surface of the flat substrate by the above processing method is transferred to a resin material (film), and this film is bonded to the outer peripheral surface of the cylindrical mold with high positional accuracy. It may be used. Moreover, the fine structure formed on the surface of the flat substrate by the above processing method may be transferred to a thin film such as nickel by electroforming, and the thin film wound around a roller.

  As the material of the cylindrical mold, it is desirable to use a material that can easily form a fine uneven structure and has excellent durability. From such a viewpoint, a glass roll, a quartz glass roll, a nickel electroformed roll, a chromium electroformed roll, an aluminum roll, or a SUS roll (stainless steel roll) is preferable.

  As the base material for the nickel electroforming roll and the chromium electroforming roll, a conductive material having conductivity can be used. As the conductive material, for example, materials such as iron, carbon steel, chrome steel, cemented carbide, steel for molds (for example, maraging steel), stainless steel, aluminum alloy and the like are preferably used.

  It is desirable to perform a mold release process on the surface of the cylindrical mold. By performing the mold release treatment, the surface free energy of the cylindrical mold can be reduced, so that even when continuously transferred to a photocurable resin, a good releasability and pattern shape of a fine concavo-convex structure can be obtained. Can be held.

  A commercially available release agent and surface treatment agent can be used for the release treatment. Examples of commercially available release agents and surface treatment agents include OPTOOL (manufactured by Daikin Chemical Industries), Durasurf (manufactured by Daikin Chemical Industries, Ltd.), Novec series (manufactured by 3M Corporation), and the like. Moreover, as a mold release agent and a surface treatment material, a suitable mold release agent and a surface treatment agent can be selected suitably according to the combination of the kind of cylindrical mold material and the photocurable resin to be transferred.

(Fine relief structure)
In the coating method according to the present embodiment, the fine concavo-convex structure includes a pillar shape including a plurality of conical, pyramidal or elliptical cone-shaped convex portions, or a plurality of conical, pyramidal or elliptical cone-shaped concave portions. It is a hole shape or a line and space shape. Here, the “pillar shape” is a “shape in which a plurality of columnar bodies (conical states) are arranged”, and the “hole shape” is a “shape in which a plurality of columnar (conical) holes are formed”. is there.

  In addition, in the arrangement of the pillar shape and the hole shape, the distance between the fine irregularities can be changed at random, hexagonal lattice, square lattice, and a certain period, and the arrangement can be selected depending on the application.

  Although it does not prescribe | regulate especially regarding the scale of a fine structure depending on the use used, it refers to tens of nanometers to tens of micrometers. The scale may be the size, diameter, depth, and pitch of one microstructure. A random structure can be one of the fine structures.

  As described above, according to the coating method according to the present embodiment, the transfer resin can be applied to the transfer substrate 16 with the peripheral speed ratio reduced, and therefore, the transfer resin is a thin film with respect to the transfer substrate 16 and It can be transferred without unevenness. Thereby, contamination to a metal mold | die and the to-be-transferred base material 16 can be suppressed.

  Hereinafter, although the Example and comparative example which were performed in order to confirm the effect of this invention are described, the range of this invention is not specifically limited by these. The characteristics in each example were measured as follows.

(Viscosity measurement)
The viscosity of the photocurable resin used as the coating solution was a viscometer (TVE-25L manufactured by Toki Sangyo Co., Ltd.). Using a circulator, the temperature was kept constant at 25 ° C., and the measurement was performed using a cone plate type (E type). First, the viscosity at 25 ° C. was calibrated using a viscometer calibration standard solution (JS50 manufactured by Nippon Grease Co., Ltd.). Subsequently, the viscosity measurement of the photocurable resin which is a coating liquid was implemented.

(Measurement of coating thickness)
The coating film thickness was measured after coating and before mold transfer, that is, in a state where the photocurable resin was fluid before photocuring. A film thickness monitor (Otsuka Electronics Co., Ltd.) was used for the measurement. First, the relative spectrum of the photo-curing resin applied to the substrate to be transferred is measured using an optical spectroscopic method with a standard version (AL vapor deposition mirror) with a known total reflectance as a reference, and then the absolute reflectance is derived by calculation. To do. From the obtained absolute reflectance, the optical film thickness was derived and used as the coating film thickness. The coating film thickness is measured at three points in the substrate width direction, and the measurement wavelength range is 330 nm to 1100 nm. The refractive index n of the photocurable resin before photocuring is the refractive index of the photocurable resin after curing. The rate n was introduced and the film thickness was calculated. The refractive index n of the photocurable resin after curing was measured using a refractometer (manufactured by Metricon, model 2010 prism coupler). From the refractive indexes at wavelengths of 532 nm, 632.8 nm, and 824 nm, the refractive indexes at all wavelengths were derived from Cauchy's equation.

Example 1
As the substrate to be transferred, PET film: A4100 (manufactured by Toyobo Co., Ltd .: width 300 mm, thickness 100 μm) was used. Examples of the photocurable resin include 1.9-nonanediol diacrylate (light acrylate 1.9ND-A manufactured by Kyoeisha Chemical Co., Ltd.), trimethylolpropane triacrylate (M350 manufactured by Toagosei Co., Ltd.), and Irgacure (registered trademark) 184 (BASF). And Irgacure 369 (manufactured by BASF) were mixed at a weight ratio of 15: 100: 5.5: 2.0 to prepare a photocurable resin. This photocurable resin was applied to the surface of the substrate to be transferred (the easy-adhesion surface of the PET film) under the application conditions and application equipment shown in Table 1. The diameter of the application part of the gravure roll at this time is 20 mm, the diameter of the non-application part is 10 mm, the groove volume is 5.9 cm ³ / m ² , and the viscosity of the photocurable resin at this time is 46 mPa · sec. there were. Moreover, the running speed of the base material was 0.5 m / min, and the peripheral speed ratio Vr / Vf was 0.25. The coating film thickness was measured at three points, and the average was 1.6 μm. In all examples and comparative examples, the blade material, the pressure applied to the gravure roll, and the angle of contact were the same.

Next, a substrate to be transferred (PET film) coated with a photocurable resin is pressed against a cylindrical mold (hexagonal lattice filling structure of concave holes) with a nip roll (0.1 MPa), and the temperature is 20 in the atmosphere. Irradiation with ultraviolet rays using a UV exposure apparatus (Fusion UV Systems Japan Co., Ltd., H bulb) so that the integrated exposure under the center of the lamp is 1000 mJ / cm ² at 50 ° C. and humidity of 50%. The film was photocured to obtain a reel-shaped transfer film (length 150 m, width 300 mm) having a fine relief structure transferred on the surface. As a result of confirming the surface unevenness of the surface of the reel-shaped transfer film with a scanning electron microscope, the adjacent distance between the protrusions was 300 nm, and the height of the protrusions was 250 nm.

(Example 2)
As shown in the coating conditions in Table 1, with respect to Example 1, the running speed of the base material was 3.0 m / min, and the peripheral speed ratio Vr / Vf was 0.50. Otherwise, the same as in Example 1 Carried out. The coating film thickness was measured at three points, and the average was 2.1 μm.

  Moreover, as a result of confirming the surface unevenness | corrugation shape of the reel-shaped transfer film transferred from the metal mold | die by scanning electron microscope observation, the adjacent distance of convex parts was 300 nm, and convex part height was 250 nm. .

Example 3
As shown in the coating conditions in Table 1, with respect to Example 1, the diameter of the gravure roll was 30 mm, and the peripheral speed ratio Vr / Vf was 0.18. The coating film thickness was measured at three points and averaged 1.8 μm.

  Moreover, as a result of confirming the surface unevenness | corrugation shape of the reel-shaped transfer film transferred from the metal mold | die by scanning electron microscope observation, the adjacent distance of convex parts was 300 nm, and convex part height was 250 nm. .

(Comparative Example 1)
As shown in the coating conditions in Table 1, with respect to Example 1, the running speed of the base material was 0.5 m / min, and the peripheral speed ratio Vr / Vf was 0.08. Other than that, the same as in Example 1 Carried out. The coating film thickness was measured at three points, but the film thickness unevenness was severe and could not be measured.

(Comparative Example 2)
As shown in the coating conditions in Table 1, with respect to Example 1, the running speed of the base material was 0.5 m / min, and the peripheral speed ratio Vr / Vf was 1.00. Otherwise, the same as in Example 1 Carried out. The coating film thickness was measured at three points and the average was 5.8 μm.

  Moreover, as a result of confirming the surface unevenness | corrugation shape of the reel-shaped transfer film transferred from the metal mold | die by scanning electron microscope observation, the adjacent distance of convex parts was 300 nm, and convex part height was 250 nm. .

(Comparative Example 3)
As shown in the coating conditions of Table 1, with respect to Example 1, the running speed of the base material was 4.0 m / min, and the peripheral speed ratio Vr / Vf was 0.20. Otherwise, the same as in Example 1 Carried out. The coating film thickness was measured at three points, but the film thickness unevenness was severe and could not be measured.

(Comparative Example 4)
As shown in the coating conditions of Table 1, with respect to Example 1, the running speed of the base material was 4.0 m / min, and the peripheral speed ratio Vr / Vf was 0.50. Carried out. The coating film thickness was measured at three points, and the average was 4.5 μm.

  Moreover, as a result of confirming the surface unevenness | corrugation shape of the reel-shaped transfer film transferred from the metal mold | die by scanning electron microscope observation, the adjacent distance of convex parts was 300 nm, and convex part height was 250 nm. .

(Comparative Example 5)
As shown in the coating conditions in Table 1, with respect to Example 1, the diameter of the non-coated part of the gravure roll was set to 20 mm, which was the same as that of the coated part, and the rest was performed in the same manner as in Example 1. Note that W1 at this time indicates the width of the region in which the groove is engraved. The coating film thickness was measured at three points and averaged 1.8 μm.

  Moreover, as a result of confirming the surface unevenness | corrugation shape of the reel-shaped transfer film transferred from the metal mold | die by scanning electron microscope observation, the adjacent distance of convex parts was 300 nm, and convex part height was 250 nm. .

  As can be seen from the results shown in Table 1, by preventing the protrusion of the resin and suppressing the coating film thickness unevenness in the width direction, it is possible to suppress the resin contamination of the film edge or the mold, In addition, the transferability of the nanostructure can be sufficiently ensured.

  In addition, this invention is not limited to the said embodiment, It can change and implement variously. In the above-described embodiment, the size, shape, and the like illustrated in the accompanying drawings are not limited to this, and can be appropriately changed within a range in which the effects of the present invention are exhibited.

  The coating method and the coating apparatus of the present invention are not limited to the nanoimprint apparatus, but can be widely introduced into applications and mechanical facilities that require a thin film and uniform coating.

  The coating method of the present invention can apply the transfer resin to the surface of the substrate to be transferred thinly and uniformly, and can be suitably applied to a roll-to-roll nanoimprint apparatus.

10 Coating device 11 Coating liquid (transfer resin)
12 Accommodating member 13 Coating solution supply means 14, 50, 70 Gravure roll 15 Scraping member (blade)
16 Transfer Substrate 101 Original Fabric Roll 102 Winding Roll 104 Cylindrical Mold 105 Pressurizing Means 106 Light Source 107 Drying Furnace

Claims (2)

A first transfer step of transferring the transfer resin onto the peripheral surface while rotating a roll having a plurality of grooves engraved on the peripheral surface of the liquid transfer resin;
A scraping step of scraping off the excess transfer resin transferred to the roll with a scraping member;
A second transfer step of transferring the transfer resin from the roll to the surface of a film-like transfer substrate,
The roll has a diameter smaller than the diameter of the coating part , an application part that contacts the surface of the transfer base material in the second transfer step in a state where the transfer resin is present in the plurality of grooves , And an uncoated portion that does not contact the outermost surface of the transfer resin in the first transfer step ,
The traveling speed Vf of the substrate to be transferred is 3.0 m / min or less,
Ri der ratio (Vr / Vf) is 0.10 to 0.50 of the running speed Vf of the rotational speed Vr and the transfer target substrate of the roll,
In the roll-to-roll nanoimprint using a mold having a nano-shaped volume of 6.0 cm ³ / m ² or less , the transferred substrate on which the transfer resin has been transferred from the roll in the second transfer step. coating wherein the Rukoto used.   2. The coating method according to claim 1, wherein the traveling speed Vf is 1.0 m / min or less, and the ratio (Vr / Vf) is 0.10 or more and 0.20 or less.

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