JP2010137420A - Printing letterpress for electronics - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a printing letterpress optimum for forming a wire and an electrode in a display panel, and for manufacturing an insulating material and an organic EL element, restraining a size of the wire from getting large, and enhancing film thickness uniformity of a printed matter. <P>SOLUTION: This printing letterpress is used in letterpress printing for transferring ink supplied to a top face of a relief of the letterpress to the matter to be printed, a thickness of the relief is 10 μm or more to 500 μm or less, and a plurality of successive slender-shaped recesses in substantially parallel to a long side direction of the relief is provided on the top face of the relief. The printing letterpress is optimum for forming the wire and the electrode in the display panel, and for manufacturing the insulating material and the organic EL element, since restraining the size of the wire from getting large, and enhancing the film thickness uniformity of the printer matter. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a relief printing plate that can be used for patterning an electronic material by a relief printing method.

  Conventionally, a photolithographic method has been generally used to form a display panel or circuit pattern having a fine size. The printing method is expected to be a method that can reduce costs because it has advantages such as faster processing speed, less waste associated with the process, and higher material utilization efficiency than the photolithographic method. In terms of performance, it was not able to meet the demand. Therefore, recently, attempts have been made to improve methods for patterning electronic materials using various printing methods.

  Organic EL devices are described by Tang and VanSlyke, Appl. Phys. Lett. 51, p. Since being reported in 913 (1987), research and development has been actively conducted. Generally, an organic EL element is divided into two types, a low molecular organic material and a high molecular organic material. As a method for forming a low molecular weight organic material, vacuum deposition is generally used. However, in the vapor deposition method, since the film is formed in a vacuum, it is difficult to increase the area, and the utilization efficiency of the material is not sufficient.

  On the other hand, various printing methods can be used as a method for producing the polymer organic material. Examples of various printing methods include letterpress printing, gravure printing, screen printing, offset printing, ink jet, and spray. These films can be formed at atmospheric pressure, and the area can be easily increased as compared with the vapor deposition method. Moreover, since the utilization efficiency of material is also high, it is advantageous in terms of cost.

  As described above, various printing methods have been studied in the field of electronics such as circuit patterns and organic EL elements. In these electronics-related fields, since a glass substrate is often used as a substrate on which printing ink is applied, a method using a hard plate such as a metal printing plate such as a gravure printing method is not suitable. Further, when ink adheres to the non-image area, problems such as contamination occur. The ink jet method has no problem such as contamination, but has a problem in printing speed.

  As a representative example of the relief printing method, there is a flexographic printing method using a plate made of a resin material. FIG. 1 is a schematic diagram of the relief printing method. In the flexographic printing method, since the plate is made of resin, the plate is relatively easy to process, the plate material is flexible, the substrate is damaged, and the pattern formed earlier is overprinted. There are advantages such as reduced damage, a non-image area due to the relief printing, and high printing speed. These features are advantageous when applied to electronic devices.

  However, letterpress and letterpress printing methods have hardly been used as means for printing and forming fine patterns. The main reason is that there is a problem that the line thickness and the film thickness uniformity of the printed material are poor, and it is difficult to accurately form a fine pattern. 2A and 2B are diagrams showing problems during transfer in letterpress printing, where FIG. 2A is a cross-sectional view of a printing relief plate, FIG. 2B is a cross-sectional view showing a state in which ink is pressed against a substrate, and FIG. (C) is a top view which shows the ink transcribe | transferred to the board | substrate. In the relief printing method, printing pressure must be applied in the process of transferring the ink as shown in FIG. 2, but the ink 2 sandwiched between the relief 7 of the printing plate and the substrate 1 is moved from the leading end of the relief to the periphery thereof. The ink sticks out to form an ink stick out 8, and a line thickness 9 is generated in which the printed pattern is larger than the original pattern 10 of the printing plate. Therefore, it becomes difficult for the printed pattern to maintain a predetermined dimension.

  Further, when the pattern becomes high definition and the distance between the patterns becomes small, there arises a problem that the adjacent pattern is connected due to the thick line. In particular, when a conductive pattern such as a wiring or an electrode is formed, the connection of the pattern causes a short circuit, and there is a problem that it cannot function normally.

  For example, there is a method (for example, refer to Patent Document 1) in which, after the ink is hardened at the convex portion of the plate to prevent marginal, the solidified ink component is transferred to a substrate through an adhesive substance. In addition, a method of providing a barrier around the convex portion of the plate has been proposed (see, for example, Patent Document 2). Furthermore, a method has also been proposed in which a depression is provided in the convex portion of the plate and excess ink is accommodated in the depression (see, for example, Patent Document 3). In addition, a method has been proposed in which a number of depressions are provided in the convex portions of the plate to suppress marginal and improve the uniformity of the printed matter (see, for example, Patent Document 4).

  However, in the technique of Patent Document 1, when electrical connection is required between a pattern formed earlier in an electronic device or the like and a pattern formed later, there is a problem of a decrease in mutual conductivity. In addition, in the lamination with the insulating layer, there is a problem of influence on device characteristics due to generation of traps at the interface. Furthermore, in the transfer of a thin film that is fragile in strength, there may be a problem that cracks are caused in the film due to stress during transfer.

  Further, in the technique of Patent Document 2, when the viscosity of the ink is low, the pressing to the work becomes uneven, and when there is already a pattern, there is a concern that the ink flows out without being suppressed by the barrier due to the step.

  Further, in the technique of Patent Document 3, when repeated printing is performed, it is necessary to satisfy the condition that there is no ink in the dent in order to accommodate excess ink. However, as the number of times of printing increases, ink remains in the dent. There is a fear, and there is a concern about the problem of a decrease in sustainability of the effect during repeated printing. In addition, since Patent Document 3 does not consider the relief thickness, there is a problem of a decrease in printing durability (printing durability) and the influence of the printing accuracy at the edge when the printed matter is fine, especially when the space width between lines is narrowed. Does not consider the problem of growing. Patent Document 3 describes the effect of reducing dot gain, which is a problem in ordinary flexographic printing, but presents the problem of the effect of suppressing thinning of thin lines, which is a problem in the field of electronic materials, and specifically describes a solution method. Not shown.

  Further, since the technique of Patent Document 4 does not consider the relief thickness, the problem of a decrease in printing durability (printing durability) or the printing of the end portion when the printed matter is fine, especially when the space width between lines is narrowed. The problem that the influence of accuracy becomes large (for example, the linearity of both ends of the printed matter deteriorates when the line width becomes small) is not specifically shown. Moreover, it does not specifically show the suppression of the thickening of a thin line important in the electronic material field.

Japanese Patent No. 3475498 JP 2002-117755 A JP 2002-178654 A JP 2006-240283 A

  The present invention solves the above-described problems and is capable of suppressing line thickness and improving the thickness uniformity of printed matter, which is optimal for the formation of wiring in a display panel, the formation of electrodes, and the production of insulating materials and organic EL elements. It is an object to provide a relief printing plate.

  As a result of intensive studies to solve the above problems, the present inventors have completed the present invention. That is, the present invention is as follows.

  The present invention relates to a relief printing for use in relief printing that transfers the ink supplied to the top surface of the relief of the relief relief to a printing medium, wherein the relief has a thickness of 10 μm or more and 500 μm or less, and the relief Provided is a relief printing plate characterized in that a plurality of elongated recesses are provided on the top surface which are substantially parallel to the long side direction of the relief.

  In the printing relief printing plate, when the distance between the depressions is defined by the shortest distance (A) of the peripheral edges of the depressions closest to each other, it is preferably 1 μm or more and 20 μm or less.

  Moreover, it is preferable that the depth of the said hollow is 1 micrometer or more and 30 micrometers or less.

  By performing pattern formation using the relief printing plate of the present invention, line thickening in the lines can be suppressed, and patterns can be prevented from being connected in pattern formation. Furthermore, the film thickness uniformity of the printed matter can be improved. For this reason, high-precision printing can be achieved even when the line width (line (L)) is narrow and the line interval (space (S)) is narrow. As a result, application to an electronic device (for example, formation of wiring, formation of an electrode, and formation of a functional element and a circuit using an insulating material or a functional material) by a printing method becomes possible.

  Embodiments of the present invention will be described with reference to the accompanying drawings. The embodiment described below is an example of the configuration of the present invention, and the present invention is not limited to the following embodiment. Various modifications may be made as long as the effects of the present invention are achieved.

  The printing relief plate provided by the present invention corresponds to the printing plate 6 in FIG. 1 and is a printing relief plate having a depression on the top surface of the relief. The relief printing plate according to the present invention is used for relief printing in which the ink supplied to the top surface of the relief of the relief plate is transferred to a printing medium, and the relief thickness is 10 μm or more and 500 μm or less. On the surface, a plurality of elongated recesses that are substantially parallel to the long side direction of the relief are provided for each relief (hereinafter, the recesses provided in the present invention are also referred to as “micro-recesses”). The thickness of the relief (shown as the thickness H of the relief in FIG. 2) is the height of the convex portion whose top surface is the printing surface.

  FIG. 3 is a plan view showing an embodiment in which a minute recess is provided on the top surface of the relief. In the relief printing plate according to the present embodiment, a minute recess 12 is formed on the top surface 11 of the relief of the relief printing, that is, the portion where the ink is transferred from the anilox roll. Here, a case is shown in which the line of the print pattern corresponding to the relief shape is a straight line, but the line pattern may be bent or crossed. When the line is bent, the minute depression is bent similarly, and when the line intersects, the minute depression also intersects. The present invention can correspond to a line pattern having an arbitrary shape, and the relief top surface of the relief plate is determined along the pattern shape, and accordingly, a depression is formed along the long side shape of the line pattern.

  The shape of the dent is an elongated shape that corresponds to the long side of the printed line pattern and that is continuous in parallel with the long side direction of the relief, and should be continuous from one end to the other end in the long side direction of the relief. That's fine. The depression has a bottomed shape that does not penetrate in the depth direction. Moreover, it is preferable that the dent is formed so as not to be applied to the edge of the relief. That is, it is preferable that the periphery of the recess is surrounded by a resin that forms a relief. In this case, in the relief end portion, the recess does not hang on the relief end portion, and the relief has an edge shape along the original shape, so that the pattern reproducibility is improved.

  The plurality of depressions may be arranged as depressions having the same size as shown in FIG. 3, or may be arranged with different sizes.

  The thickness of the relief is set to 10 μm or more in order to perform accurate printing from the viewpoint of the necessity of providing a depression and the amount of pressing, and to prevent stains on the printed matter, and from the viewpoint of resolution, printing durability and durability, 500 μm or less. And When the relief thickness exceeds 500 μm, the resolution is deteriorated, and in the case of a fine pattern, the film thickness uniformity of the printed matter and the linearity of the line are deteriorated. In addition, when the relief thickness is 500 μm or less, it is possible to avoid the influence of the distortion of the line at the time of high definition, to improve the reproducibility of the line and to suppress the thickening of the line. The thickness of the relief is more preferably 20 μm or more and 400 μm or less.

  According to the present invention, by providing a recess on the top surface of the relief, the flow of ink to the outside of the relief that occurs when the printing relief plate is pressed against the substrate is prevented, so that the occurrence of line weighting can be reduced. it can. Moreover, since the film thickness of the transferred ink can be adjusted by the depression, the film thickness of the printed material can be adjusted, and good film thickness uniformity can be imparted to the printed material.

  The depth of the depression formed on the relief is preferably 1 μm or more and 30 μm or less from the viewpoint of the effect of suppressing line thickness and the pattern reproducibility. When the depth of the dent is less than 1 μm, line thickening tends to occur, and when it exceeds 30 μm, it is difficult for ink to enter and exit, and the pattern reproducibility tends to deteriorate. The depth of the depression is more preferably 1 μm or more and 20 μm or less.

  In the printing relief plate according to the present invention, as shown in FIG. 3, the distance between the recesses defined by the shortest distance (A) of the peripheral edges of the recesses closest to each other (shown as the distance A between the recesses in FIG. 3). Is preferably 1 μm or more and 20 μm or less. By setting the distance between the depressions in such a range, the leveling property of the ink is promoted, and the film thickness uniformity of the printed matter becomes better. The distance between the depressions is more preferably 1 μm or more and 14 μm or less.

  The length of the long side of the dent (here, the length of the long side refers to the maximum length of the dent in the direction parallel to the relief long side) is not particularly limited because it is determined by the length of the pattern. The length of the short side (here, the length of the short side means the maximum length of the depression in the direction perpendicular to the relief long side) is sufficient. The length of the short side is preferably 2 μm or more and 40 μm or less. When the length of the short side is less than 2 μm, the effect of suppressing line thickness tends to be small, and when it exceeds 40 μm, the effect of improving the film thickness uniformity of the printed matter tends to be small.

  Next, the example of the manufacturing method of the relief printing plate of this invention is described. Examples of the method for forming a relief pattern on a printing relief plate include (1) a method of forming by light, (2) a method of duplicating from a mold, and (3) a method of forming by engraving.

(First method: method of forming a relief pattern with light)
In the method of forming a relief pattern with light, a photosensitive resin can be used, and the following methods can be mentioned. By a method using a normal photosensitive resin, the photosensitive resin is matched with the shape of the relief, and a negative film is prepared which transmits light in a portion not corresponding to the minute depression in the upper portion of the relief and does not transmit in other portions. When a liquid photosensitive resin is used before exposure, after laminating this negative film on the surface of the glass plate, a liquid photosensitive resin is applied thereon, a transparent base film is laminated on the surface, and the A glass plate is laminated on the surface. Note that the thickness of the photosensitive resin layer is set to a predetermined dimension. Next, using a lamp, the photosensitive resin is irradiated with ultraviolet rays through the upper glass plate and the base film, and the photosensitive resin is irradiated with ultraviolet rays through the lower glass plate and the negative film. A well-known irradiation light source for image exposure can be used. A portion where a predetermined amount of light entering from the entire upper surface of the layer made of the liquid photosensitive resin and light transmitted through the light transmitting portion of the negative film reaches a predetermined amount is cured. After curing, the upper and lower glass plates and the negative film are removed, the uncured portion is washed and removed, and the relief forming side is irradiated with ultraviolet rays to accelerate the curing to obtain a relief printing plate.

  As another method, for the relief formation, a laser light source having a wavelength capable of curing the photosensitive resin may be used, and the amount of light necessary for curing may be scanned and exposed. In the case of using a photosensitive resin that is not a liquid type at room temperature but a solid solution at room temperature, after the photosensitive resin is heated to be molded to a predetermined thickness, operations after image exposure are similarly performed.

  Furthermore, the method for producing a relief printing plate using a negative type photosensitive resin has been described above. However, it is also possible to use a positive type photosensitive resin together with a positive film.

  In addition, a method can be used in which a mold is prepared in advance on a photomask and the depth of the depression is controlled more accurately. For example, a positive type photosensitive resin having a film thickness corresponding to the depth of the minute depression is deposited on the negative film, and the exposed portion is developed by irradiating ultraviolet rays from the negative film side. As a result, minute protrusions corresponding to the minute depressions are formed on the light shielding portion of the negative film. On the mold formed on the negative film, a negative photosensitive resin is further applied according to a desired relief thickness, and a base film is laminated on the surface. Next, ultraviolet rays are irradiated from the lower side (negative film side) through the negative film and mold, the negative film and the mold are removed, and the uncured portion is washed and removed, thereby accurately forming a relief having a minute depression on the base film. be able to. At this time, when a base film having a relatively high diffuse reflectance is used, the incident ultraviolet rays are diffusely reflected on the surface of the base film, and curing of the entire relief portion can be promoted. In order to securely attach the mold to the negative film, the surface of the negative film is coated with a commercially available adhesive (rubber, polyester, epoxy, acrylic, urethane, silane, etc.) having ultraviolet transparency. It is possible to perform a treatment, to provide various coating materials such as a hard coat (acrylic or the like) on the adhesive layer, and to perform a surface treatment with a coupling agent or the like.

(Second method: Method of copying from a mold)
The following method can be mentioned as a method for producing a replication pattern from a mold. A mold corresponding to the pattern shape is produced, and the mold is taken by a method suitable for the relief being made of resin. As a method, 1) a photocuring method and 2) a thermosetting method can be employed. Or 3) a thermal transfer method (also referred to as a cooling solidification method) in which a heated mold is pressed against a resin to give a shape corresponding to a pattern. A photosensitive resin can be used for the above 1), a thermosetting resin that is liquid or solid solution at room temperature, and a thermoplastic resin can be used for the above 3). The mold may be selected from known ones depending on the processing method employed and the resolution. For example, a metal mold, Si mold, quartz mold, SiC mold, Ni electric mold, resin mold, or the like can be used.

(Third method: Method of forming by engraving)
As a method of forming by engraving, the following methods can be mentioned. It is possible to use a crosslinked rubber-based material, a cured thermosetting resin, a similarly cured photocurable resin, a thermoplastic resin, or the like as the plate material. Examples of a method for engraving a solid plate material include a laser engraving method. In practice, lasers may be properly used according to the required pattern shape dimensions. Various lasers such as a carbon dioxide laser, a YAG third or fourth harmonic laser, or an excimer laser can be selected and engraved according to the resolution and engraving property. If this method is used, it is also possible to produce a combination plate in which the surface free energy of the top surface of the relief and the groove portion are different. In this case, the relief tip layer and the layer below the relief tip layer and the layer below it can be surface-free by various methods such as stacking different materials, applying different materials, or performing plasma treatment. It is also possible to create different combinations of energy and sculpt with a laser to reach the lower layer.

  As the material for forming the relief printing plate according to the present invention, as described above, a thermoplastic resin that is solid at room temperature and fluid at high temperature, and a photosensitive resin or thermosetting resin that is viscous or solid solution at room temperature. The plates can be molded using the respective plastic or curable properties. There are no particular restrictions on the type of resin. Select and design the resin so that the mechanical properties in the form used as a plate, such as hardness, Young's modulus, rebound resilience, tensile strength and elongation, surface tension, or solvent resistance, are suitable for the desired printing. That's fine. Further, a crosslinked rubber-based material can also be a material for forming the printing relief plate according to the present invention.

  As the negative photosensitive resin, a radical polymerization system, a photocationic polymerization system, a photoanion polymerization system, a photodimerization reaction system, or the like is applicable. Hereinafter, a general-purpose radical polymerization system will be described as an example.

  Many of radically polymerizable resin compositions can be applied to the present invention, and among them, a composition containing a prepolymer, a monomer, an initiator, and a thermal polymerization inhibitor can be used as a representative one.

  The prepolymer has at least one polymerizable double bond in the molecule, such as unsaturated polyester, unsaturated polyurethane, unsaturated polyamide, unsaturated polyacrylate resin, unsaturated methacrylate resin, or various modified products thereof. The thing using at least 1 type can be mentioned.

  The monomer is typically an ethylenically unsaturated monomer having a polymerizable double bond, such as styrene, chlorostyrene, vinyltoluene, diallyl phthalate, diallyl isophthalate, triallyl cyanurate, N, N ′. -Methylenebisacrylamide, methacrylamide, N-hydroxyethylacrylamide, N-hydroxymethacrylamide, α-acetamide, acrylamide, acrylic acid, methacrylic acid, α-chloroacrylic acid, paracarboxystyrene, 2,5-dihydroxystyrene, tri Ethylene glycol diacrylate, triethylene glycol dimethacrylate, and the like, and Photopolymer Social Society, “Photopolymer Handbook”, published by Kogyo Kenkyukai, June 26, 1989, p. The material described in 31-36 can be used.

  As the initiator, a known photopolymerization initiator or thermal polymerization initiator used for increasing the reaction efficiency when performing a three-dimensional crosslinking reaction using an ethylene addition polymerizable unsaturated group can be used. As radical photopolymerization initiators, benzoin, benzoin isobutyl ether, benzoin isopropyl ether, benzophenone, Michler ketone, xanthone, thioxanthone, chloroxanthone, acetophenone, 2,2-dimethoxy-2-phenylacetophenone, benzyl, 2,2-dimethyl- 2-hydroxyacetophenone, (2-acryloyloxyethyl) (4-benzoylbenzyl) dimethylammonium bromide, (4-benzoylbenzyl) trimethylammonium chloride, 2- (3-dimethylamino-2-hydroxypropoxy) -3-, 4-Dimethyl-9H-thioxanthone-9-one-mesochloride, 1-phenyl-1,2-propanedione-2- (Obenzoyl) oxime, thiophenol, 2-benzothiazole Thiol, 2-benzoxazole thiol, 2-benzimidazole thiol, diphenyl sulfide, decyl phenyl sulfide, di-n-butyl disulfide, dibenzyl sulfide, dibenzoyl disulfide, diacetyl disulfide, divinyl disulfide dimethoxyxanthogen disulfide, tetramethylthiuram monosulfide , Tetramethylthiuram tetrasulfide, benzyldimethyldithiocarbamate quinoxaline, 1,3-dioxolane, N-laurylpyridinium and the like. On the other hand, as the thermal polymerization initiator, known compounds such as benzoyl peroxide, 2,2-azobisisobutyronitrile, peroxides such as persulfate-sodium hydrogen sulfite, azo compounds, and redox initiators can be used. .

  As thermal polymerization inhibitors used in the present invention, hydroquinone, mono-tert-butylhydroquinone, benzoquinone, 2,5-diphenyl-p-benzoquinone, picric acid, di-p-fluorophenylamine, p-methoxyphenol, 2,6- And di-tert-butyl-p-cresol.

  Examples of the photosensitive resin composition include those described in JP-A-52-90804, JP-B-48-19125, JP-A-49-109104, JP-B-48-41708, and the like. Furthermore, Toray Research Center, Research and Research Division, “New Development of Photopolymer Technology” published by Toray Research Center, March 10, 1993, p. 35-37, supervised by Atsuo Yamaoka, “Basics and Applications of Photopolymers”, CMC Publishing, March 27, 2003, Chapter 4 Platemaking Materials and Photoresists, Supervised by Shinji Matsui et al., “Development and Application of Nanoimprints” , CMC Publishing, August 31, 2005, p. 50 and p. 151 can be used. P. 158 and p. The acrylate, methacrylate or fluorine-containing epoxy photosensitive resin having a fluorine-modified fluoroalkyl group described in 159 can also be used.

  Further, a photopolymerizable rubber composition comprising at least unvulcanized rubber, a monomer having a polymerizable double bond, and a polymerization initiator, so-called photosensitive elastomer (for example, JP-A-51-106501 and JP-A-47-37521) and a dialkyl silicone resin that requires a balance with ink-generating properties can be used.

  Thermoplastic resins include polymethyl methacrylate (PMMA), polycarbonate (PC), cyclic polyolefin resin (COP), polyamide (PA), polyacetal (POM), polybutylene terephthalate (PBT), polyethylene terephthalate (PET), poly Methyl pentene (TPX), modified polyphenylene ether (PPE), polyphenylene sulfide (PPS), polyether ether ketone (PEEK), polyether imide (PEI), polyarylate (PAR), polysulfone (PSF), polyether sulfone ( PES), polyamideimide (PAI), polyethylene (PE), polypropylene (PP), polystyrene (PSt), vinyl chloride (PVC), vinylidene chloride (PVDC), acrylonitrile Styrene (AS), acrylonitrile / butadiene / styrene (ABS), fluorinated resins such as vinylidene fluoride (PVDF), tetrafluoroethylene / norbornene copolymers, fluorine-containing acrylic resins, fluorine-containing acrylic resins, Fluorine polyimide resin, fluorine-containing vinyl ether resin, and the like can be used. Any other materials that can be processed by heat can be used. For example, Tadahiro Miwa, “Science of Basic Synthetic Resins”, Gihodo Publishing Co., Ltd. May 15, p. 113-p. 397, discussions 1. Polymerization type resin The thermoplastic resin described in the condensation type resin may be used.

  Examples of the thermosetting resin include at least one resin of unsaturated polyester, unsaturated polyurethane, unsaturated polyamide, unsaturated polyacrylate, unsaturated methacrylate, or various modified products thereof, and an ethylenically unsaturated group having a polymerizable double bond. A radical polymerizable resin composition containing a saturated monomer and a thermal polymerization initiator, a resin composition obtained by adding a curing agent to epoxy, a silicon-based polydimethylsiloxane resin, or the like may be used. As the fluorinated resin, a thermosetting resin using a fluorinated monomer or a fluorinated oligomer containing a crosslinking agent or a polymerization initiator that generates radicals by heat may be used. Other than this, for example, Tadahiro Miwa, “Science of Basic Synthetic Resins”, Gihodo Publishing Co., Ltd., June 15, 1987, p. 240-p. 397, each discussion 2. You may use the thermosetting resin as described in condensation type | mold resin.

  As the rubber material, natural rubber, butadiene, isoprene, chloroprene, butyl, ethylene propylene, styrene butadiene, polyisobutylene, styrene butadiene, nitrile, acrylic, epichlorohydrin, urethane, silicon, and fluorine rubber may be used.

  By using the methods and materials described above, the relief printing plate according to the present invention can be made.

  The relief printing plate of the present invention can be obtained by forming a plate on the support using the various resins as described above. The support preferably has a small dimensional change and can be bent in accordance with the diameter of the plate cylinder so as to be suitable for a use mode in which the substrate is often wound around the plate cylinder. Specific examples include a plastic substrate such as a PET substrate, an aluminum substrate, a stainless steel (SUS) substrate, and various metal substrates. In particular, a glass composite plastic substrate and a SUS substrate are preferable in that the dimensional change is small and rust is difficult. Moreover, the relief printing plate of the present invention may be not only a sheet shape but also a roll-shaped seamless plate. In the case of a roll, it is not necessary to consider bending at the time of attachment. Therefore, the material of the roll is not particularly limited, but a material having a small dimensional change is preferable.

  Next, an example of a printing machine that can be used for printing using the relief printing plate according to the present invention will be described. For example, a commercially available printer shown in FIG. 1 can be used. This is an example and is not limited to this method. Printing is performed as follows. 1 is used, the ink 2 is supplied to the anilox roll 3 and the doctor blade 4 that are provided with projections and depressions, and the anilox roll 3 rotates to measure the ink. Next, when the anilox roll 3 and the relief printing plate 6 wound around the plate cylinder 5 come into contact with each other, ink adheres to the top surface which is the tip of the relief. In this state, the printing relief plate 6 is pressed against the substrate 1 to transfer the ink.

  The printing method according to the above-described embodiment is a relief printing method including a step of performing printing by pressing the relief printing plate according to the present invention against a substrate (that is, a substrate). In the transfer step in which the printing relief plate is arranged on the outer peripheral surface of a cylindrical plate cylinder and the plate cylinder is rolled to transfer to the printing medium, the relief and the printing medium are pushed in during the transfer. It is preferable to print with a printing pressure such that the amount is 100 μm or less. In the case of a printing pressure at which the pressing amount is higher than 100 μm, the relief is crushed, the effect of the depression is reduced, and the line thickness and the film thickness uniformity of the printed matter may be reduced.

  Next, the printed matter formed using the relief printing plate according to the present invention will be described. Examples of the printed material include an organic EL element, an organic thin film solar cell, a transistor, an electrode, and a wiring.

  A transistor will be described as an example of a printed material. First, a conductive pattern corresponding to a gate electrode and wiring is printed on a substrate by using a printing relief plate. As the ink for forming the conductive pattern, an ink in which metal fine particles are dispersed, a conductive polymer, or the like can be used. Next, a pattern corresponding to the gate insulating film of the transistor is printed in alignment with a predetermined position on the formed pattern. The letterpress for printing is replaced with one corresponding to the pattern of the insulating film. Thereafter, the version is changed each time the pattern is changed. As the ink for forming the gate insulating film, an organic material dissolved in a solvent or an inorganic coating material such as a polysilazane material can be used. Next, a source electrode and a drain electrode and wirings connected to these are formed at predetermined positions. Next, a semiconductor pattern is formed so as to straddle the source electrode and the drain electrode. As the ink for forming a semiconductor pattern, organic semiconductors such as polythiophene derivatives and polyacenes that are soluble in a solvent can be used. Next, in order to protect the element, a protective film pattern is formed so as to cover these patterns. As the material for the protective film, a polymer resin material or the like dissolved in a solvent can be used.

  Moreover, an organic EL element is demonstrated as another example of printed matter. Organic EL elements are used in displays and lighting applications. The organic EL element has a structure in which an organic substance is sandwiched between an anode and a cathode. Among these, as the process using the relief printing plate of the present invention, a process of applying an organic substance, specifically, a hole injection material or a light emitting material sandwiched between the electrodes at the time of electrode formation is suitable. As an electrode forming method, a transparent electrode such as indium tin oxide (ITO) is printed in a desired pattern on a glass substrate or a plastic substrate. When producing this transparent electrode, a pattern can be produced using the printing method using the relief printing plate according to the present invention. Moreover, also in the case of forming the hole injection material and / or hole transport material on the ITO electrode and further the light emitting material thereon, the printing method using the relief printing plate according to the present invention can be used.

  Examples of the hole injection material, the hole transport material, or the hole injection / transport material having the functions of both materials include aromatic amine materials, phthalocyanine complexes such as copper phthalocyanine (CuPc) and zinc phthalocyanine (ZnPc), and aniline-based materials. Examples include polymers, polyphyllin compounds, imidazole derivatives, triazole derivatives, pyrazoline derivatives, oxazole derivatives, oxadiazole derivatives, stilbene derivatives, polyarylalkane derivatives, and acene compounds such as anthracene, tetracene, pentacene, and hexacene. Also, derivatives of these acene compounds, that is, the above acene compounds are alkyl groups, alkoxy groups, halogen groups, ketone groups, ester groups, ether groups, amino groups, hydroxy groups, benzyl groups, benzoyl groups, phenyl groups, Derivatives into which a substituent such as a naphthyl group is introduced, quinone derivatives of the above acene compounds, and the like are also included.

  Also, polyaniline, polyvinylanthracene, polycarbazole, poly (N-vinylcarbazole) (PVK), polyfluorene, poly (ethylenedioxy) thiophene / poly (styrenesulfonic acid) (PEDOT / PSS), thiophene-fluorene copolymer , Phenylene ethynylene-thiophene copolymer, polyalkylthiophene, poly (p-phenylene vinylene), and other polymer hole injection materials such as thiophene compounds or polymer hole transport materials.

Examples of the light emitting material include polymer light emitting materials such as poly (para-phenylene vinylene), poly (thiophene), poly (fluorene), and derivatives thereof. In addition, tris (8-hydroxyquinolinolato) aluminum complex (Alq ₃ ), bis (2-methyl-8-quinolinolato) (p-phenylphenolato) aluminum (III) (BAlq), bis (benzoquinolinolato) Beryllium complex (BeBq ₂ ), phenanthroline-based europium complex (Eu (TTA) ₃ (phn)), perylene, coumarin derivatives, quinacridone, iridium complex (Ir (ppy) ₃ , Irpic, Ir (ppy) ₂ (acac)) Examples thereof include fluorescent materials and phosphorescent materials.

  These may be used by doping a small amount into a host material having holes or electron transporting properties or both. Such host materials include 4,4′-bis (9-carbazole) biphenyl (CBP), 2,7-di-9-carbazolyl-9,9′-spirobiflurane (spiro-CBP), bis (2-methyl). -8-quinolinolato) (p-phenylphenolato) aluminum (III) (BAlq), poly (N-vinylcarbazole) (PVK), and the like.

  When the printing method of the present invention is used, the above various materials (for example, a hole injection material, a hole transport material, a light emitting material, an organic semiconductor material, etc.) are used by being dispersed or dissolved in various solvents. As the solvent at that time, water, methanol, ethanol, propanol, butanol, hexanol and other alcohols, ethylene glycol, propylene glycol and other glycols, acetone, methyl ethyl ketone and other ketones, ethyl acetate, butyl acetate and other esters, Ethers such as dioxane and tetrahydrofuran, amides such as N, N-dimethylformamide, benzene, toluene, xylene, trimethylbenzene, hexane, heptane, octane, nonane, decane, cyclohexane, decahydronaphthalene (decalin), tetralin and the like And hydrocarbons.

  EXAMPLES The present invention will be described below with reference to examples and comparative examples, but the present invention is not limited to the following examples.

1) Manufacturing method of relief printing plate 1 having minute depressions FIG. 4 is a plan view showing the line / space shape and the depression shape of the quartz mask. In the shape of a line / space (L / S 200 μm / 400 μm, length 20 mm) as shown in FIG. 4, quartz having a thickness of 2.3 mm having rectangular light-shielding portions corresponding to minute depressions at equal intervals in the light transmission portion. A chrome mask was prepared. After the surface of the quartz chrome mask is treated with a UV cleaning apparatus, HMDS (1,1,1,3,3,3-Hexamethyldisilazane) (1,1,1,3,3,3-hexamethyldibenzene) is obtained in a nitrogen atmosphere. Silazane) was treated for 20 minutes. A positive photosensitive resin was applied to the quartz chrome mask surface with a spin coater so that the thickness after drying was 10 μm, air-dried, and then heat-treated at 110 ° C. for 7 minutes. As the positive photosensitive resin, PMER (P-LA300PM) manufactured by Tokyo Ohka Co., Ltd. was used. Next, exposure and dip development (developing solution P-7G) were performed from the quartz chrome mask side using a parallel light exposure apparatus manufactured by Oak, and air-dried, followed by further heat treatment at 110 ° C. for 5 minutes. On a resin mold formed on this quartz chrome mask, a 4 wt% solution of CYTOP (CTX-809AP2) manufactured by Asahi Glass Co., Ltd. as a release agent was applied by a spin coater so as to have a thickness of 0.5 μm. Dry at 10 ° C. for 10 minutes. After applying the negative liquid photosensitive resin APR-G31 (polyester resin) manufactured by Asahi Kasei Chemicals Co., Ltd. to a thickness of 100 μm using a knife coater on the obtained resin mold treated with the release agent, A stainless sheet (SUS304) having a thickness of 150 μm was laminated as a base film on the upper surface. The stainless sheet used was a surface treated with a silane coupling agent (KBM-503) manufactured by Shin-Etsu Chemical Co., Ltd. The exposure was performed from the quartz chrome mask side using an oak parallel light exposure apparatus with an exposure amount of 500 mj / cm ² (measured at 350 nm). For printing an L / S pattern having a predetermined micro-dent on the top surface of a relief by peeling off the base film from the resin mold, washing with a cleaning solution comprising a 0.1 wt% sodium carbonate solution and a surfactant, performing post-exposure. Letterpress 1 was obtained. The relief printing plate 1 has a relief thickness of 100 μm and a line width of 200 μm, and has a fine recess continuously on the top surface of the relief substantially parallel to the relief long side direction, and the length of the long side of the micro recess is about 20 mm (however, both ends in the long side direction of the recess are recessed 10 μm inside from both ends in the long side direction of the relief so that the side of the recess is surrounded by the relief constituent material), and the length of the short side is 28 μm The distance A between the micro dents is 10 μm, and the depth of the micro dents is 10 μm. FIG. 5 is a drawing-substituting photograph showing a micrograph of the relief printing plate 1.

2) Method for producing printing relief plate 2 having minute depressions Printing relief plate 2 was produced in the same manner as printing relief plate 1 except that the shape of the light shielding part of the quartz chrome mask was different. The relief printing plate 2 has a relief thickness of 100 μm and a line width of 200 μm, and has a fine depression on the top surface of the relief, and the length of the long side of the fine depression is about 20 mm (however, both ends in the long side direction of the depression are The recesses are surrounded by relief constituent materials by retreating inward by 15 μm from both ends in the long side direction of the relief.), The short side length is 22 μm, and the distance A between the microrecesses is 15 μm. The depth of the depression is 10 μm. FIG. 6 is a drawing-substituting photograph showing a micrograph of the relief printing plate 2.

3) Manufacturing method of printing relief plate 3 having no micro-dents After applying negative type liquid photosensitive resin APR-G31 (polyester resin) manufactured by Asahi Kasei Chemicals Corporation using a knife coater to a thickness of 100 μm A stainless sheet (SUS304) having a thickness of 150 μm was laminated as a base film on the upper surface of the coating. The stainless sheet used was a surface treated with a silane coupling agent (KBM-503) manufactured by Shin-Etsu Chemical Co., Ltd. Exposure was performed at 500 mj / cm ² from the quartz chrome mask side using a parallel light exposure apparatus manufactured by Oak. The base film is peeled off from the resin mold, washed with a cleaning solution comprising a 0.1 wt% sodium carbonate solution and a surfactant, post-exposure is performed, and there is no L / S pattern micro-dent with a 100 μm thick relief. A relief printing plate 3 was obtained (L / S 200 μm / 400 μm, length 20 mm). The relief printing plate 3 has a relief thickness of 100 μm and a line width of 200 μm, and is a solid plate having a flat structure without a micro-dent on the relief top surface. FIG. 7 is a drawing-substituting photograph showing a micrograph of the relief printing plate 3.

[Example 1]
A printing experiment was performed using the relief printing plate 1. The printing conditions are as follows. That is, the obtained relief printing plate was attached to the plate cylinder of a precision printing machine manufactured by JEOL. The ink used for printing was Harima Kasei Co., Ltd. silver ink (NPS-J metal weight 57%, 8.4 mPa · S). As the printing method, an anilox roll 550 lines / inch was used, inking was performed from the anilox roll to the relief printing plate, and the ink was transferred from the printing relief plate to the glass substrate. The printing pressure during transfer to the workpiece was defined by the amount of indentation, and the amount of indentation was adjusted by the height of the surface plate. This experiment was performed with an indentation amount of 70 μm. The glass substrate after printing was dried at 220 ° C. for 30 minutes. For the evaluation, a microscope (Vert Scan 2.0 / Ryoka System Co., Ltd.) using optical interference was used.

[Example 2]
A printing experiment was performed using the relief printing plate 2. As printing conditions, the obtained printing plate was attached to a plate cylinder of a precision printing machine manufactured by JEOL. The ink used for printing was Harima Kasei Co., Ltd. silver ink (NPS-J metal weight 57%, 8.4 mPa · S). As the printing method, an anilox roll 550 lines / inch was used, inking from the anilox roll to the printing plate was performed, and ink was transferred from the printing plate to the glass substrate. The printing pressure during transfer to the workpiece was defined by the amount of indentation, and the amount of indentation was adjusted by the height of the surface plate. In this experiment, the indentation amount was 70 μm. The glass substrate after printing was dried at 220 ° C. for 30 minutes. For the evaluation, a microscope (Vert Scan 2.0 / Ryoka System Co., Ltd.) using optical interference was used.

[Comparative Example 1]
Printing experiments were performed using the relief printing plate 3. As printing conditions, the obtained printing plate was attached to a plate cylinder of a precision printing machine manufactured by JEOL. The ink used for printing was Harima Kasei Co., Ltd. silver ink (NPS-J metal weight 57%, 8.4 mPa · S). As the printing method, an anilox roll 550 lines / inch was used, inking from the anilox roll to the printing plate was performed, and ink was transferred from the printing plate to the glass substrate. The printing pressure during transfer to the workpiece was defined by the amount of indentation, and the amount of indentation was adjusted by the height of the surface plate. In this experiment, the indentation amount was 70 μm. The glass substrate after printing was dried at 220 ° C. for 30 minutes. For the evaluation, a microscope (Vert Scan 2.0 / Ryoka System Co., Ltd.) using optical interference was used.

[Printing result summary]
FIG. 8 is a diagram showing the line width increase rates of Examples 1 and 2 and Comparative Example 1, and FIG. 9 shows the ratio of (film thickness at the end / film thickness at the center) of Examples 1 and 2 and Comparative Example 1. FIG. 10 is a diagram showing ink volumes after substrate transfer in Examples 1 and 2 and Comparative Example 1. In FIG. 8, the vertical axis represents the line width increase rate. The line width increase rate is ((width of printed line) − (line width of relief top surface)) / (line width of relief top surface) × 100 (%). In FIG. 9, the vertical axis represents the ratio of (film thickness at the end) / (film thickness at the center). In FIG. 10, the vertical axis represents the ink volume (μm ³ ). The ink volume is a value of the transfer amount of ink with respect to a plate having a predetermined same area. Here, the absolute value has no meaning, but a relative comparison is possible.

As a result, when Examples 1 and 2 were compared with Comparative Example 1, Examples 1 and 2 had a lower line width increase rate than Comparative Example 1. In Example 1 and Example 2, the line width increase rate was lower in Example 1 than in Example 1. In Example 1, the ratio of (film thickness at the end) / (film thickness at the center) was close to 1. That is, in Example 1, it turns out that the line thickness of a printed matter is suppressed and the uniformity of a film thickness is high. Further, the amount of ink transferred to the substrate is larger in Example 1 and Example 2 than in Comparative Example 1. Therefore, according to the present invention, it can be seen that the ink transfer amount can be ensured and the line weight can be suppressed.
Summarizing the above results, it can be seen that the printing performance of Example 1 is very good in the order of Example 1> Example 2> Comparative Example 1.

  The relief printing plate provided by the present invention is suitable when a fine pattern production related to an electronic material is carried out by a relief printing method.

It is the schematic of a relief printing method. It is a figure which shows the subject at the time of transcription | transfer in relief printing. It is a top view which shows one form which provides the micro dent of a relief top surface. It is a top view which shows the shape of the line / space of a quartz mask, and the shape of a hollow. It is a drawing substitute photograph which shows the microscope picture of the letterpress 1 for printing. It is a drawing substitute photograph which shows the microscope picture of the letterpress 2 for printing. It is a drawing substitute photograph which shows the microscope picture of the letterpress 3 for printing. It is a figure which shows the line | wire width increase rate of Example 1, 2 and the comparative example 1. FIG. It is a figure which shows the ratio of (film thickness of an edge part / film thickness of a center) of Example 1, 2 and Comparative Example 1. FIG. FIG. 4 is a diagram illustrating ink volumes after substrate transfer in Examples 1 and 2 and Comparative Example 1.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Board | substrate 2 Ink 3 Anilox roll 4 Doctor blade 5 Plate cylinder 6 Plate 7 Relief 8 Ink protrusion 9 Line weight 10 Original pattern 11 Relief top surface 12 Micro dent H Relief thickness

Claims (3)

  A relief printing plate for use in relief printing for transferring ink supplied to the top surface of a relief relief to a substrate, wherein the relief has a thickness of 10 μm or more and 500 μm or less, and on the relief top surface, A letterpress for printing, comprising a plurality of elongated recesses that are substantially parallel to the long side direction of the relief.   The printing relief printing plate according to claim 1, wherein the distance between the depressions is 1 μm or more and 20 μm or less when the distance between the depressions closest to each other is defined as the shortest distance (A) between the depressions.   The relief printing plate according to claim 1 or 2, wherein the depression has a depth of 1 µm or more and 30 µm or less.