JP2010158883A - Letterpress printing method of electronics material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a letterpress printing method which is most suitable for formation of wiring in a display panel, formation of an electrode and production of an insulating material or an organic EL element and which can suppress line fattening and can improve film thickness uniformity. <P>SOLUTION: A letterpress for printing having relief is made to a cylindrical shape in a state where a top face of the relief is turned outside and the letterpress for printing is rolled around a cylinder shaft while supplying ink from an anilox roll to the top face of the relief to transfer the ink from the letterpress for printing to a body to be printed. The letterpress printing method contains this transfer step. The letterpress for printing has a plurality of recesses with an aperture area of 10 to 1,600 μm<SP>2</SP>at the top face of the relief, the number of lines of the anilox roll is ≥400 line/inch and <700 line/inch and further the aperture area per one recess is made to be smaller than the aperture area per one cell of the anilox roll. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a printing method for patterning by using a relief printing method for an electronic material.

  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 process waste, and higher material utilization efficiency than the photolithographic method. The point was not able to meet the request. 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 substance, 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. For organic thin-film solar cells, printing methods are being studied from the viewpoints of large area, material utilization efficiency, and process speed, as with organic EL elements.

  As described above, various printing methods have been studied in connection with electronics such as circuit patterns, organic EL elements, and organic thin-film solar cells. 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 application to electronic devices is assumed (see, for example, Patent Document 1).

  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 relief printing plate and the substrate 1 is transferred from the leading end of the relief. The ink sticking out 8 is formed around the periphery, and a line thickness 9 is generated in which the printed pattern is larger than the original pattern 10 of the printing relief 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. In the above-mentioned Patent Document 1, ink is not flown into the low-order part and the concave part which are non-image line parts other than the top face of the convex part of the printing relief plate by appropriately setting the number of lines of the anilox roll. Therefore, although there is a description that the pattern shape is not collapsed and the film thickness does not change, a specific problem and a solution for suppressing the above-described line thickening are not shown.

JP 2008-135326 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 method.

  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.

[1] A relief printing plate having a relief is formed in a cylindrical shape with the top surface of the relief facing outward, and the printing relief plate is centered on a cylindrical axis while supplying ink from the anilox roll to the top surface of the relief. A transfer step of transferring the ink from the relief printing plate to the printing material by rolling
The relief printing plate is, the opening area 10 [mu] m ² or more 1600 .mu.m ² less depression has a plurality on the top surface of the relief,
Letterpress printing wherein the number of lines of the anilox roll is not less than 400 lines / inch and less than 700 lines / inch, and the opening area per recess is smaller than the opening area per cell of the anilox roll Method.
[2] The relief printing method according to [1], wherein, in the transfer step, the transfer is performed with a printing pressure at which a pressing amount between the relief of the printing relief plate and the printing material is 200 μm or less.

  By performing pattern formation using the relief printing method of the present invention, the depression provided at the relief tip of the relief printing plate works to prevent the flow of ink during printing, and the line thickening in the line is suppressed, It is possible to prevent the patterns from being connected in the 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.

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 a some hollow in the top surface of a relief. It is a figure which shows the shape of a line / space, and the shape of a hollow. It is a figure which shows the relationship between the number of lines of an anilox roll, and a line | wire width increase rate. It is a figure which shows the relationship between the number of lines of an anilox roll, and the (film thickness of an edge part / film thickness of center) ratio. It is a figure which shows the relationship between the number of lines of an anilox roll, and a line | wire width increase rate. It is a figure which shows the relationship between the number of lines of an anilox roll, and the (film thickness of an edge part / film thickness of center) ratio.

  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.

In the relief printing method of the present invention, the relief relief printing plate is formed into a cylindrical shape with the top surface of the relief facing outward, and the cylinder axis is centered while supplying ink from the anilox roll to the top surface of the relief. Including a transfer step of transferring the ink from the printing relief plate to the printing material by rolling the printing relief plate to
Relief printing plate is, the opening area 10 [mu] m ² or more 1600 .mu.m ² less depression has a plurality on the top surface of the relief,
In this relief printing method, the number of lines of anilox roll is 400 lines / inch or more and less than 700 lines / inch, and the opening area per depression is smaller than the opening area per cell of an anilox roll. The letterpress printing plate used in the letterpress printing method of the present invention corresponds to the letter 6 in FIG. 1 and is a letterpress printing plate having a depression on the top surface of the relief. Relief printing plate for use in the present invention, the ink supplied to the top surface of the relief of the relief plate be those used in letterpress printing to transfer to the printing material, the top surface of the relief, the opening area 10 [mu] m ² or more 1600 .mu.m ² A plurality of the following depressions are provided for each relief (hereinafter, these depressions provided in the present invention are also referred to as “micro-dents”).

  FIG. 3 is a plan view showing an embodiment in which a plurality of depressions are provided on the top surface of the relief, where (a) is a circular opening shape of the depression, (b) is a rectangular opening shape of the depression, Respectively. In the relief printing plate according to the present invention, a plurality of minute recesses 12 are 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.

  The shape of the dent can be the shape of a square columnar hole (non-through and bottomed) or a cylindrical hole (non-through and bottomed). The region where a plurality of recesses are formed preferably extends over the entire top surface of the relief, and it is further preferable that the recess is not formed on the edge of the relief.

  The arrangement of the depressions is not limited to the grid arrangement as shown in FIG. 3, but may be, for example, a staggered arrangement.

  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.

  In any of the above forms, the shape of the depression at the relief end is arranged so that the relief end shape is not interrupted, or when the depression overlaps with the relief end for convenience of arrangement, the end of the depression It is preferable that the part which overlaps with is closed by the side wall which corresponds to end shape.

  The thickness of the relief is preferably 10 μm or more from the viewpoint of enabling accurate printing from the viewpoint of the necessity of providing a dent and the amount of pressing, and from the viewpoint of preventing stains on the printed matter, and resolution, printing durability and durability. From the viewpoint of the above, it is preferably 500 μm or less. Here, the thickness of the relief is the height of the convex portion whose top surface is the printing surface. When the thickness of the relief exceeds 500 μm, the resolution tends to deteriorate, and in the case of a fine pattern, the uniformity and the linearity of the line tend to deteriorate. In particular, in the case of high definition, the thickness of the relief is preferably 500 μm or less from the viewpoint of improving the reproducibility of the line and suppressing the thickening of the line due to the influence of the distortion of the line. The thickness of the relief is more preferably 10 μm or more and 400 μm or less.

  According to the present invention, by providing a depression on the top surface of the relief, the flow of ink to the outside of the relief that occurs when the relief plate is pressed against the printing substrate is prevented, so that the occurrence of line weighting can be reduced. . In the relief end portion, when the depression is arranged so that the relief does not hang over the relief end portion and the relief has an edge line portion along the original shape, the reproducibility of the pattern is also improved. Further, the film thickness of the transferred ink can be adjusted by the depression, and therefore the film thickness of the printed matter can be adjusted. The depth of the depression formed on the relief is preferably 1 μm or more and 30 μm or less, and more preferably 1 μm or more and 20 μm or less, from the viewpoint of the effect of suppressing line thickness.

  The area ratio of the depression formed on the relief is preferably 30% or more and less than 70% from the viewpoint of film thickness uniformity of the printed matter. Here, the area ratio means (total opening area of the depressions formed on the top surface of the relief) / (total area of the top surface of the relief).

In the present invention, the opening area of the recess formed on the top surface of the relief, from the point of view of the printed matter thickness uniformity of 10 [mu] m ² or more 1600 .mu.m ² or less. Furthermore, since the opening area per depression is smaller than the opening area per cell of the anilox roll, printing omission corresponding to a minute depression does not occur, and high-definition printing becomes possible.

  Next, a method for producing a relief printing plate will be described. Examples of the method for forming a printing relief pattern include (1) a method of forming by light, (2) a method of replicating from a mold, and (3) a method of forming by engraving.

(First method: Method of forming a pattern with light)
A photosensitive resin can be used in the method of forming a pattern with light, and examples of the method include the following methods. In accordance with a method using a normal photosensitive resin, the photosensitive resin is matched to the shape of the relief, and a negative film is prepared which transmits light in a portion not corresponding to the minute depression at the top of the relief and does not transmit light 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.

  Further, it is possible to adopt a method in which a mold (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: A method of copying a pattern 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 or 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 according to the employed processing method and resolution. For example, metal molds, Si molds, quartz molds, SiC molds, Ni electric molds, resin molds and the like can be used.

(Third method: Method of forming a pattern by engraving)
Examples of the method for forming a pattern by engraving include the following methods. 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, 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 the plate, such as hardness, Young's modulus, impact resilience, tensile strength, 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. And the like using at least one of them.

  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 ones such as peroxides such as benzoyl peroxide, 2,2-azobisisobutyronitrile, 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 polyolefins such as vinylidene fluoride (PVDF) and tetrafluoroethylene / norbornene copolymers as fluorine resins, fluorine-containing acrylic resins, fluorine-containing polyimide resins, Fluorine vinyl ether resins can be used as long as they can be processed by heat. For example, Tadahiro Miwa, “Science of Basic Synthetic Resins”, Gihodo Publishing Co., Ltd., June 15, 1987, 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 used in the present invention may be one 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 according to the diameter of the plate cylinder so as to be suitable for a use mode in which it is often used by being 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. The printing relief plate used in the present invention is not limited to the sheet shape as shown in FIG. 1, but may be, for example, a roll-shaped seamless plate. When using a sheet-like printing relief plate, the printing relief plate can be formed into a cylindrical shape by disposing the printing relief plate on the outer peripheral surface of the cylindrical plate cylinder with the relief facing outward. . In addition, when a roll-shaped relief printing plate is used, it is not necessary to consider bending at the time of attachment because a plate cylinder is unnecessary. 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 in the relief printing method of 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 is rotated to measure the ink. . Next, when the anilox roll 3 and the 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 plate 6 is pressed against the substrate 1 to transfer the ink.

In the relief printing method of the present invention, relief printing plate is, having a plurality of open area 10 [mu] m ² or more 1600 .mu.m ² following the depression in the top surface of the relief as described above, and, ruling of the anilox roll 400 lines / More than inch and less than 700 lines / inch. By setting both the opening area of the depression of the printing relief plate and the number of lines of the anilox roll within the above range, it is possible to prevent the ink from flowing out during printing, to suppress line thickness and to make the film thickness of the printed matter uniform. it can. The effect of preventing the ink from flowing out by setting the number of anilox rolls to 400 lines / inch or more and less than 700 lines / inch is particularly remarkable when the viscosity of the ink is 200 mPa · S or less.

  The cell shape of the anilox roll can be, for example, a hexagon, a polygon such as a quadrangle, a circle, or the like.

  In the present invention, as described above, the opening area per depression of the top surface of the relief of the printing relief printing plate is made smaller than the opening area per cell of the anilox roll, but the opening per depression The ratio A / B of the area (A) to the opening area (B) per cell of the anilox roll is preferably in the range of A / B = 5/100 to 99/100. When the ratio is 5/100 or more, there is an effect of suppressing line thickness, and when it is 99/100 or less, the effect of preventing printing omission corresponding to a minute depression is better. The ratio is more preferably in the range of 10/100 to 90/100.

  The depth of the anilox roll cell is preferably 1 μm or more and 60 μm or less from the viewpoint of ink retention and ease of access.

  In the transfer step, transfer is performed with a printing pressure at which the relief of the relief printing plate and the printing medium is 200 μm or less, that is, from the state where the relief and the printing medium are brought into contact with each other without printing pressure. It is preferable to perform the transfer by applying a printing pressure such that the amount of pressing of the relief printing plate and / or the printing medium in the thickness direction is 200 μm or less in total. In the case of a printing pressure at which the pressing amount is higher than 200 μm, the relief is crushed, the effect of the depression is reduced, and there may be a problem in the effect of suppressing line thickness and the film thickness uniformity of the printed matter. In the present invention, it is more preferable to perform the transfer with a printing pressure at which the amount of pressing is 100 μm or less.

  Next, an example of a printed matter formed using the relief printing method of 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 formed on a substrate by letterpress printing. 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 them, as the process using the printing method 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 according to the present invention. The printing method according to the present invention can also be used when forming a hole injection material and / or a hole transport material on the ITO electrode, and further a light emitting material thereon.

  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, and an organic semiconductor material) can be 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.

  Moreover, an organic thin-film solar cell is demonstrated as another example of printed matter. Organic thin-film solar cells have a structure in which an organic material is sandwiched between an anode and a cathode. Among them, the steps of using the printing method of the present invention include organic substances sandwiched between the electrodes at the time of electrode formation, specifically inks containing p-type organic semiconductor materials, inks containing n-type organic semiconductor materials, and p-type organics. A process of applying an ink in which a semiconductor material and an n-type organic semiconductor material are mixed 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 according to the present invention. The present invention also applies to the case where an ink containing a p-type organic semiconductor material, an ink containing an n-type organic semiconductor material, or a mixed ink of a p-type organic semiconductor material and an n-type organic semiconductor material is applied on the ITO electrode. Such a printing method can be used.

  Examples of the p-type organic semiconductor material include pentacene, pentacene derivatives such as 6,13-bis (triisopropylsilylethynyl) pentacene, tetracene derivatives such as tetracene and 2-hexyltetracene, N, N′-diphenyl-N, N′— Bis (1-naphthyl) -1,1′-biphenyl-4,4′-diamine (NPD), N, N′-diphenyl-N, N′-bis (3-methylphenyl) -1,1′-biphenyl Examples include aromatic amine-based materials such as -4,4'-diamine (TPD) and 1,3,5-tris (3-methyldiphenylamino) benzene (m-MTDATA). In addition, phthalocyanine complexes such as copper phthalocyanine (CuPc) and zinc phthalocyanine (ZnPc), polyphyllin compounds, perylene derivatives, imidazole derivatives, triazole derivatives, pyrazoline derivatives, oxazole derivatives, oxadiazole derivatives, stilbene derivatives And polyarylalkane derivatives. Moreover, derivatives of thiophene, derivatives of polyphenylvinylene (PPV), and the like can be given. Specific examples of thiophene derivatives include P3HT (Poly (3-hexylthiophene-2,5-diyl)), P3OT (Poly (3-octylthiophene-2,5-diyl)), P3DDT (Poly (3-dodecylthiophene- 2,5-diyl)) and the like.

Examples of n-type organic semiconductor materials include fluorinated acene compounds, fullerene compounds such as 60PCBM ([6,6] -phenylC ₆₁ butyric acid methyl ester) and 70PCBM ([6,6] -PhenylC ₇₁ butyric acid methyl ester). , Naphthalene derivatives, anthracene derivatives, phenanthrene derivatives, pyrene derivatives, perylene derivatives, perylene tetracarboxylic acid diimide derivatives, oxadiazole derivatives, triazole derivatives, triazine derivatives, quinoline derivatives, and the like.

  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 having minute depressions FIG. 4 is a diagram showing the shape of a line / space and the shape of a depression. 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 onto the surface of the quartz chrome mask by a spin coater so that the thickness was 13 μm after drying, and air-dried, followed by heat treatment 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 .mu.m and a line width of 200 .mu.m. The relief has a square depression with a square opening on the top surface. The length of one side of the depression is 34.8 .mu.m. The opening area per contact was 1208 μm ² , the distance between the micro-recesses was 12.2 μm, and the depth of the micro-recesses was 13 μm. The depth was measured with a microscope using optical interference (Vert Scan 2.0 / Ryoka System Co., Ltd.).

2) Manufacturing method of printing letterpress having no micro-dent After applying negative type liquid photosensitive resin APR-G31 (polyester resin) manufactured by Asahi Kasei Chemicals Co., Ltd. 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 2 was obtained (L / S 200 μm / 400 μm, length 20 mm). The relief printing plate 2 is a solid plate having a relief thickness of 100 μm, a line width of 200 μm, and having a flat structure without a micro-dent on the top surface of the relief.

[Example 1]
A printing experiment was performed using the relief printing plate 1. As printing conditions, the obtained relief printing plate was attached to a cylindrical plate cylinder. 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 (number of lines: 550 lines / inch) was used, inking was performed from the anilox roll to the relief printing plate, and ink was transferred from the relief 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 30 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 1. As printing conditions, the obtained relief printing plate was attached to a cylindrical plate cylinder. The ink used for printing was Harima Kasei Co., Ltd. silver ink (NPS-J metal weight 57%, 8.4 mPa · S). As an printing method, an anilox roll (number of lines: 550 lines / inch) was used, inking was performed from the anilox roll to the relief printing plate, and ink was transferred from the relief 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 pressing amount was 50 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]
A printing experiment was performed using the relief printing plate 2. As printing conditions, the obtained relief printing plate was attached to a cylindrical plate cylinder. The ink used for printing was Harima Kasei Co., Ltd. silver ink (NPS-J metal weight 57%, 8.4 mPa · S). As an printing method, an anilox roll (number of lines: 550 lines / inch) was used, inking was performed from the anilox roll to the relief printing plate, and ink was transferred from the relief 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 pushing amount was 30 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 2]
A printing experiment was performed using the relief printing plate 1. As printing conditions, the obtained relief printing plate was attached to a cylindrical plate cylinder. The ink used for printing was Harima Kasei Co., Ltd. silver ink (NPS-J metal weight 57%, 8.4 mPa · S). As an printing method, an anilox roll (number of lines: 300 lines / inch) was used, inking was performed from the anilox roll to the relief printing plate, and the ink was transferred from the relief 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 30 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 3]
A printing experiment was performed using the relief printing plate 1. As printing conditions, the obtained relief printing plate was attached to a cylindrical plate cylinder. 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 (number of lines: 700 lines / inch) was used, inking from the anilox roll to the relief printing plate, and ink was transferred from the relief 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 30 μm. The glass substrate after printing was dried at 220 ° C. for 30 minutes. As a result, there was a dropout corresponding to a micro-dent in the printed product line (a portion that was not printed), and it was not printed cleanly. Therefore, the printed matter could not be evaluated.

[Comparative Example 4]
A printing experiment was performed using the relief printing plate 2. As printing conditions, the obtained relief printing plate was attached to a cylindrical plate cylinder. The ink used for printing was Harima Kasei Co., Ltd. silver ink (NPS-J metal weight 57%, 8.4 mPa · S). As an printing method, an anilox roll (number of lines: 550 lines / inch) was used, inking was performed from the anilox roll to the relief printing plate, and ink was transferred from the relief 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 pressing amount was 50 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 5]
A printing experiment was performed using the relief printing plate 1. As printing conditions, the obtained relief printing plate was attached to a cylindrical plate cylinder. The ink used for printing was Harima Kasei Co., Ltd. silver ink (NPS-J metal weight 57%, 8.4 mPa · S). As an printing method, an anilox roll (number of lines: 300 lines / inch) was used, inking was performed from the anilox roll to the relief printing plate, and the ink was transferred from the relief 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 pressing amount was 50 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 6]
A printing experiment was performed using the relief printing plate 1. As printing conditions, the obtained relief printing plate was attached to a cylindrical plate cylinder. 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 (number of lines: 700 lines / inch) was used, inking from the anilox roll to the relief printing plate, and ink was transferred from the relief 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 pressing amount was 50 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 experiment result summary 1]
Place where the cell one per opening area of the anilox roll used in Examples and Comparative Examples were measured by a digital microscope, opening area, the case of 300 lines / inch, be between 4300Myuemu ² of 5450Myuemu ² If the 550 lines / inch, is between 1300 [mu] m ² of 1800 .mu.m ^2, in the case of 700 lines / inch, was between 850 .mu.m ² of 1200 [mu] m ^2.

  The printing results of Example 1 and Comparative Examples 1 and 2 are summarized in FIGS. FIG. 5 is a diagram showing the relationship between the number of anilox roll lines and the line width increase rate, with the horizontal axis representing the number of anilox roll lines and the vertical axis representing the line width increase rate. The line width increase rate is {(print line width) − (line width of relief top face)} / (line width of relief top face) × 100 (%). FIG. 6 is a diagram showing the relationship between the number of anilox roll lines and the ratio of (end film thickness / center film thickness) ratio. The horizontal axis represents the number of anilox roll lines and the vertical axis represents (end film thickness). The value of (film thickness) / (center film thickness) ratio was taken.

  As a result, when Example 1 was compared with Comparative Examples 1 and 2, in Example 1, the line width increase rate was low, and 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 film thickness uniformity of a printed matter is high.

[Printing experiment result summary 2]
The printing results of Example 2 and Comparative Examples 4, 5, and 6 are summarized in FIGS. FIG. 7 is a diagram showing the relationship between the number of lines of anilox roll and the line width increase rate. The horizontal axis represents the number of lines per inch of the anilox roll and the vertical axis represents the line width increase rate. The line width increase rate is {(print line width) − (line width of relief top face)} / (line width of relief top face) × 100 (%). FIG. 8 is a diagram showing the relationship between the number of anilox roll lines and the ratio of (end film thickness / center film thickness) ratio. The horizontal axis represents the number of anilox roll lines and the vertical axis represents (end film thickness). The value of (film thickness) / (center film thickness) ratio was taken.

  As a result, when Example 2 was compared with Comparative Examples 4, 5 and 6, in Example 2, the line width increase rate was low, and the ratio of (film thickness at the end) / (film thickness at the center) was close to 1. It was. That is, in Example 2, it turns out that the line thickness of a printed matter is suppressed and the film thickness uniformity of a printed matter is high.

  The present invention is suitable when fine pattern production related to an electronic material is performed by a relief printing method.

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 Minute dent

Claims (2)

The relief printing plate is formed into a cylindrical shape with the top surface of the relief facing outward, and the printing relief plate rolls around the cylinder axis while supplying ink from the anilox roll to the top surface of the relief. A transfer step of transferring the ink from the relief printing plate to the printing material by
The relief printing plate is, having a plurality of open area 10 [mu] m ² or more 1600 .mu.m ² following the depression in the top surface of the relief,
Letterpress printing, wherein the number of lines of the anilox roll is not less than 400 lines / inch and less than 700 lines / inch, and the opening area per recess is smaller than the opening area per cell of the anilox roll Method.   2. The relief printing method according to claim 1, wherein, in the transfer step, the transfer is performed with a printing pressure at which a pressing amount between the relief of the printing relief plate and the printing material is 200 μm or less.

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