JP6035807B2 - Topographic printing device - Google Patents

Description

  The present invention relates to a relief printing apparatus for forming a high-definition pattern using an organic functional material as ink, and an organic functional element produced using the same.

  In recent years, organic functional elements such as organic EL (electroluminescence) elements using organic functional materials, organic solar cells, and organic thin film transistors have been actively developed with the aim of reducing the weight and flexibility of electronic components. ing. In these organic functional elements, it is generally necessary to pattern-form an organic functional layer having a film thickness of about several nm to several μm on the substrate.

  An organic EL element will be described in detail as an example. The organic EL element is a light emitting element having a structure in which an organic light emitting layer having an organic EL material is formed between two opposing electrodes, and emits light when a voltage is applied.

  The organic EL material used for the organic EL layer is classified into a low molecular material and a high molecular material, and the method of forming the organic EL layer differs depending on the type of material.

  Generally, a low molecular weight material is formed into a thin film on a substrate by resistance heating vapor deposition (vacuum vapor deposition) or the like. This method is excellent for forming a uniform thin film and is an advantageous method for controlling the film thickness. However, there is a problem that it is difficult to maintain the pattern accuracy when the substrate becomes large.

  On the other hand, in a polymer material, an organic light emitting material is dissolved or dispersed in a solvent to form an ink, and a thin film is formed by a wet coating method. As the wet coating method, there are a spin coating method, a bar coating method, a protruding coating method, a dip coating method, etc., but it is difficult to use for patterning and color coating, and in order to perform high-definition patterning, etc. It is necessary to use pattern printing by an ink jet method or a printing method.

  For example, in a pattern formation method by an ink jet method as disclosed in (Patent Document 1), an organic EL material dissolved in a solvent is ejected from an ink jet nozzle onto a substrate and dried on the substrate. Form. However, since the ink droplets ejected from the nozzle are spherical, the ink spreads in a circular shape when landing on the substrate, and the shape of the formed pattern lacks linearity or the landing accuracy is poor. Therefore, there is a problem that the linearity of the pattern cannot be obtained.

  In addition, there are various types of pattern forming methods by printing methods. For organic EL elements that often use glass substrates as substrates, offset printing methods using rubber printing blankets, rubber and other A letterpress printing method using a photosensitive resin plate mainly composed of a resin is considered an appropriate printing method. Actually, a pattern printing method using offset printing (Patent Document 2), a pattern printing method using letterpress printing (Patent Document 3), and the like have been proposed. Among them, the method by letterpress printing is excellent in pattern formation accuracy and film thickness uniformity, and is most suitable as a method for producing an organic EL element by printing.

  An example of the process of forming the organic EL film by the relief printing method will be described. FIG. 1 shows a schematic diagram of an example printing apparatus used for manufacturing an organic EL element using a relief printing method. The ink 5 in which the organic EL material filled in the ink chamber is dissolved or dispersed in a solvent is applied to the surface by immersing the anilox roll 6 having fine holes. Next, excess ink on the roll surface is scraped off by the doctor 4 so that the amount of ink applied per unit area of the anilox roll is made uniform. Then, the ink on the anilox roll is transferred to the image forming portion of the printing relief plate 8 having the image forming portion provided corresponding to the shape of the pixel of the organic EL element, and finally, on the image forming portion of the printing plate. The ink thin film is transferred onto the substrate 2 to form a transfer pattern 9 (organic EL film).

  When the ink in the anilox roll cell is transferred to the relief printing plate, it is necessary to dip the anilox roll in the ink in the ink chamber and replenish the ink in the cell. However, at this time, depending on conditions such as a high rotation speed of the roll and a short immersion time, ink replenishment and circulation are not sufficiently performed, and a phenomenon (ghost) in which a transfer history appears on the printed matter occurs. In order to prevent ghosting, it is preferable to make the circumference of the anilox roll longer than the transfer pattern length of the printing relief printing plate so that one transfer can be completed within one turn of the anilox roll. It is necessary to circulate the ink inside with the ink in the ink chamber.

  Organic EL materials used for ink are generally expensive, and it is necessary to keep the amount used as small as possible. Therefore, a technique aimed at reducing the number of liquids has been developed by a direct coating method in which ink is directly applied to an anilox roll using a die coating, a spray coating method or the like.

  When printing many sheets continuously, density unevenness due to ink drying on a ghost or anilox roll is more likely to occur. In the method in which the anilox roll is immersed in the ink, the ink on the anilox roll is mixed with the ink in the ink chamber and circulates. An anilox roll cleaning is required every time, resulting in a large consumption of cleaning liquid and a complicated process.

  From these, in order to perform stable printing, it is necessary to increase the diameter of the anilox roll and to sufficiently immerse the ink on the anilox roll in order to stabilize the ink concentration in the anilox roll cell. I have a problem that I want to reduce.

Japanese Patent Laid-Open No. 10-12377 JP 2001-93668 A JP 2001-155858 A

  The present invention provides a relief printing apparatus capable of forming a high-definition, high-quality, low-cost organic functional element using a small amount of ink made of an organic functional material, and a machine functional element produced using the same. For the purpose.

  As a result of studies to solve the above-described problems, it has been found that the following means are effective.

The invention described in claim 1 of the present invention is a relief printing apparatus comprising a relief plate, a plate cylinder, an anilox roll, and an ink supply unit, wherein the anilox roll contacts a convex portion of the relief plate mounted on the plate cylinder. And the ink supply unit has a function of supplying ink to the anilox roll, and the ink supply unit includes an ink chamber having an ink reservoir structure; An inking roll having a diameter smaller than the ink chamber diameter is included therein, the inking roll diameter is smaller than the anilox roll diameter, and the anilox roll and the inking roll have a gap without being in direct contact with each other. The inking roll is immersed in ink between the anilox roll and the inking roll. By rotating in a state, an ink liquid level is formed on the upper part of the inking roll, and an ink liquid surface formed on the upper part of the inking roll is brought into contact with the anilox roll to supply ink to the anilox roll. A letterpress printing apparatus, wherein a doctor for removing excess ink inked on the anilox roll rotation direction side is installed on the anilox roll immediately after the contact position between the anilox roll and the ink liquid surface. It is.

The invention according to claim 2 of the present invention, compared to the surface tension surface tension of the ink of the inking roll, a letterpress apparatus of claim 1 Symbol placement being greater or equivalent.

  Invention of Claim 4 of this invention is an organic functional element produced using the relief printing apparatus in any one of Claims 1-3.

According to the first, second and third aspects of the present invention, in order to supply ink to the anilox roll, an ink chamber having an ink reservoir structure and an ink supply unit having an inking roll installed therein are provided. Thus, ink can be supplied to the anilox roll by contacting the ink liquid surface above the inking roll formed by rotating the inking roll immersed in ink and the anilox roll. At this time, since the anilox roll and the inking roll are not in direct contact with each other, they are not damaged by the contact. In addition, by making the inking roll diameter smaller than the anilox roll diameter, a smaller ink chamber can be used compared to the conventional structure in which the anilox roll is directly immersed in the ink reservoir. , A continuous and stable pattern can be formed.
Further, by using this relief printing apparatus, an organic functional element such as an organic EL element having no light emission unevenness can be produced by a printing method in a state where the amount of ink used is reduced.

It is the schematic which shows one Example of the conventional relief printing apparatus. It is the schematic which shows one Example of the relief printing apparatus of this invention. FIG. 3 is an enlarged schematic view of FIG. 2. It is sectional drawing which shows one Example of the organic EL element manufactured by this invention. It is sectional drawing of one Example of the board | substrate of the active matrix system used for manufacture of the organic EL element of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention is not limited to this.

  In the present invention, at least one of a light emitting layer made of an organic material and an organic EL layer made of a light emission auxiliary layer is used, and an ink made by dissolving or dispersing the organic EL material in a solvent is used. It can be applied when forming by a relief printing method using a resin relief plate having a part pattern as a printing plate. As the light emission auxiliary layer, a hole transport layer, a hole injection layer, an electron transport layer, an electron injection layer, a charge generation layer, and the like are stacked and used. Hereinafter, in the present invention, a case where an organic EL material ink in which an organic EL material is dissolved or dispersed in a solvent is used will be described.

  FIG. 1 shows a schematic diagram of an example of a relief printing apparatus used for producing a general printed matter, and FIG. 2 shows a schematic diagram of an example of a relief printing apparatus according to the present invention. In both cases, the printing substrate 2 is fixed to the stage 1, the relief plate 8 is fixed to the plate cylinder 7, and the relief plate 8 is in contact with the anilox roll 6 provided with the doctor 4.

  In a general letterpress printing apparatus, a part of the anilox roll 6 is immersed in the ink 5 filled in the ink chamber 3 so that the ink 5 is replenished in the anilox roll cell. In the relief printing apparatus of the present invention, the inking roll 9 is immersed in the ink 5 of the ink chamber 3 to form an ink liquid film on the surface of the inking roll 9. By bringing the ink liquid film and the anilox roll 6 into contact with each other, the ink 5 is replenished in the anilox roll cell.

  Excess ink 5 out of the ink 5 supplied to the anilox roll 6 is removed by the doctor 4, and the ink is uniformly held in the anilox roll 6 by the formed cell structure. As long as the excess ink is appropriately removed, the doctor 4 may be selected from a doctor blade, a doctor roll, and the like.

  In order to form a sufficient ink liquid film on the surface of the inking roll 9, it is desirable that the surface tension of the inking roll 9 is greater than or equal to the surface tension of the ink. Even when the surface tension of the inking roll 9 is smaller than the surface tension of the ink, if the ink liquid film can be formed on the surface of the inking roll 9 in an amount that can be applied to the anilox roll 6, the present invention can be applied. It is possible to use.

  In the present invention, the anilox roll 6 and the inking roll 9 are not in direct contact with each other, and a gap having a constant interval is provided therebetween. FIG. 3 shows an enlarged schematic view of the vicinity of the contacted portion in the inking state when the anilox roll 6 and the inking roll 9 are brought into contact with each other. When the anilox roll 6 and the inking roll 9 are brought into contact with each other, the ink that has been inked excessively stays between the anilox roll and the inking roll (ink reservoir 10). When printing is performed for a long time, the ink density in the ink reservoir increases, causing unevenness of the printed matter and deviation of the printed film thickness. In addition, the number of foreign matters increases when the inking roll 9 is scraped.

  As an example of the material of the inking roll 9, a core roll made of SUS material, etc., nitrile rubber, silicone rubber, isoprene rubber, styrene butadiene rubber, butadiene rubber, chloroprene rubber, butyl rubber, acrylonitrile rubber, ethylene propylene rubber, A rubber roll created by wrapping urethane rubber or the like can be used. These rubber materials are selected from the resistance to the solvent used as the ink.

  In the present invention, since the anilox roll 6 and the inking roll 9 are not brought into contact with each other, the material, hardness, etc. of the inking roll are not particularly limited. Therefore, it is possible to use a resin roll whose surface is coated with a resin such as nylon, polyester, polyurethane, ABS, vinyl chloride, or a metal roll if the required conditions such as wetting are met.

  In the present invention, the inking roll needs to have a mechanism that rotates independently of the anilox roll. When the inking roll rotates, it is not necessary to align the rotation speed with the anilox roll, and may be set independently from the viewpoint of inking property. Also, the rotation direction may be set independently from the viewpoints of inking property, ink circulation property, ink dripping condition, and the like.

FIG. 1 shows a sheet-fed letterpress printing apparatus that forms an ink pattern on a substrate to be printed one by one. However, if the substrate to be printed is compatible, a roll-to-roll letterpress printing apparatus is used. It can also be used.

  In the plate material used for the relief plate 8 according to the present invention, as the plate base material on which the convex pattern is formed, it is only necessary to have mechanical strength for printing, and synthetic resin, metal, or a laminate thereof may be used. Among them, those that maintain dimensional stability are desirable.

  The polymer that is a component of the resin that forms the convex pattern of the relief plate 8 can be selected from one or more of synthetic resins, copolymers thereof, natural polymers such as cellulose, etc. In the case of applying such a coating solution, a fluorine-based resin is desirable from the viewpoint of solvent resistance to an organic solvent.

  In addition, by containing at least one kind soluble in water-soluble solvents such as polyvinyl alcohol, polyamide, polyurethane, cellulose acetate succinate, partially saponified polyvinyl acetate, cationic piperazine-containing polyamide and derivatives thereof Since it is possible to impart solvent resistance, it is also desirable to select and use one or more of these.

  Various pattern molding methods such as a photolithography method and a printing method can be used for the convex pattern by the resin layer of the relief plate 8, but from the viewpoint of high definition of the pattern, a photolithography method using a photosensitive resin is desirable. .

  When the photolithographic method using a photosensitive resin is applied as a method for forming a convex pattern, a convex pattern of the relief plate 8 is formed from a plate-like photosensitive resin laminate in which a base material layer and a photosensitive resin layer are sequentially laminated. It is most desirable. A known method can be used as a method for molding the photosensitive resin layer.

  The molding method of the said plate-shaped photosensitive resin laminated body is shown. When an antireflection layer or the like is formed on a substrate, a film is formed by a wet coating method or a dry coating method to form a laminate. Next, a photosensitive resin layer is formed on the laminate or substrate by a known method to obtain a plate-like photosensitive resin laminate.

  A photolithography method is used for the formed plate-shaped photosensitive resin laminate, and a desired convex pattern is formed through known exposure and development processes.

  Next, an example of the manufacturing process of the organic EL element using the partition substrate will be described. FIG. 4 shows an organic EL element, and FIG. 5 shows an explanatory sectional view of a partition substrate. The manufacturing process according to the present invention is not limited to this.

  By forming a thin transistor (TFT) 30 on the substrate, a substrate for an active matrix organic EL element can be obtained. The drive system of the present invention is not limited to the active matrix.

  The TFT and its upper layer are supported by a support 21. The support is preferably excellent in mechanical strength and dimensional stability. Any substrate can be used as the support as long as it is an insulating substrate. In the case of a bottom emission type organic EL device that extracts light from the support side, it is necessary to use a transparent support.

  For example, a glass substrate or a quartz substrate can be used as the support. Further, when demanding flexibility, a plastic film or sheet may be used. A metal oxide thin film, a polymer resin film, or the like may be laminated for the purpose of preventing moisture and the like from entering these.

  As the TFT provided on the support, a known thin film transistor can be used. Specifically, a thin film transistor mainly including an active layer in which a source / drain region and a channel region are formed, a gate insulating film, and a gate electrode can be given. The structure of the thin film transistor is not particularly limited.

  As the partition substrate, a flattening layer 27 is formed on the TFT, the lower electrode (first electrode 13) of the organic EL element is provided on the flattening layer, and the TFT and the first electrode are Electrical connection is preferably made through a contact hole 28 provided in the planarization layer. By comprising in this way, the outstanding electrical insulation can be obtained between TFT and an organic EL element.

  The active layer 22 is not particularly limited, and can be formed of, for example, an inorganic semiconductor material such as amorphous silicon or polycrystalline silicon, or an organic semiconductor material such as thiophene oligomer.

As the gate insulating film 23, a film normally used as a gate insulating film can be used. For example, SiO ₂ formed by PECVD method, LPCVD method, or the like, or SiO obtained by thermally oxidizing a polysilicon film is used. ₂ etc. can be used.

  As the gate electrode 24, what is normally used as a gate electrode can be used, for example, aluminum, copper, titanium, tantalum, tungsten, polysilicon, silicide, polycide, etc. are mentioned.

  The display device needs to be connected so that the thin film transistor (TFT) functions as a switching element of the organic EL element, and the drain electrode 26 of the transistor and the pixel electrode (first electrode) of the organic EL element are electrically connected. ing.

  The TFT, the drain electrode, and the pixel electrode (first electrode) of the organic EL element are connected through a connection wiring formed in a contact hole that penetrates the planarization film.

Regarding the material of the planarizing film, inorganic materials such as SiO ₂ , spin-on glass, SiN (Si ₃ N ₄ ), and TaO (Ta 2 O ₅ ), organic materials such as polyimide resin, acrylic resin, photoresist material, and black matrix material are used. be able to. The formation method is selected according to the material.

  A first electrode is provided on the substrate. When the first electrode is used as an anode, the material is a single layer or stacked layers of metal composite oxides such as ITO (indium tin composite oxide) and IZO (indium zinc composite oxide), and gold and chromium. Any of these can be used. The method for forming the first electrode is selected according to the material.

  ITO is preferably used because of its low resistance, solvent resistance, and high transparency when the bottom mission method is adopted. ITO is formed on the glass substrate by sputtering, and is patterned by the photolithography method to form the first electrode 13.

After forming the first electrode, the partition wall 12 is formed so as to cover the edge of the first electrode. The partition wall needs to have insulating properties, and a photosensitive material or the like can be used. The photosensitive material may be a positive type or a negative type, a photo-curing resin of a photo radical polymerization system, a photo cationic polymerization system, or a copolymer containing an acrylonitrile component, polyvinyl phenol, polyvinyl alcohol. , Novolac resin, polyimide resin, cyanoethyl pullulan, and the like can be used. Further, as a partition wall forming _material, it is also possible to use SiO 2, TiO ₂ or the like.

  When the partition wall forming material is a photosensitive material, the entire surface of the forming material solution is coated by a slit coating method or a spin coating method, and then patterning is performed by a photolithography method such as exposure and development. When the partition is formed by a photolithography method using a photosensitive material, its shape can be controlled by exposure and development conditions.

Further, when the partition wall forming material is SiO ₂ or TiO ₂ , it can be formed by a dry film forming method such as a sputtering method or a CVD method. In this case, patterning of the partition walls can be performed by a mask or a photolithography method.

  Next, an organic EL layer including a light emitting layer and a light emission auxiliary layer is formed. The organic EL layer sandwiched between the electrodes may be composed of a light emitting layer alone, or a light emission assisting layer such as a hole transport layer, a hole injection layer, an electron transport layer, an electron injection layer, or a charge generation layer. It is good also as a laminated structure which added the layer. In addition, the presence or absence of the light emission auxiliary layer is appropriately selected as necessary. The material used for each can be selected according to the characteristics.

  The organic EL material and the solvent for dissolving or dispersing the organic EL material may be any combination that can be converted into an ink, and are used alone or in combination depending on the characteristics. Moreover, you may add surfactant, a viscosity modifier, etc. to a solvent as needed.

  Next, the second electrode 18 is formed. When the second electrode is a cathode, a material having a high electron injection efficiency is used as the material. As a forming method, a dry film forming method such as a resistance heating evaporation method, an electron beam evaporation method, or a sputtering method can be used depending on the material. Moreover, when it is necessary to make a 2nd electrode into a pattern, it can pattern by a mask etc. In the present invention, the first electrode can be a cathode and the second electrode can be an anode.

  As an organic EL element, it is possible to emit light by sandwiching a light emitting layer between electrodes and passing an electric current. However, some organic EL materials and electrode forming materials are easily deteriorated by moisture and oxygen in the atmosphere. Therefore, a sealing body is usually provided for shielding from the outside.

  For example, the sealing body is formed by using a glass cap having a recess and a metal cap with respect to the substrate on which the first electrode, the light emitting layer, the light emission auxiliary layer, and the second electrode are formed. Sealing is performed by adhering the cap and the substrate via the adhesive 19 in the periphery of the two electrodes so that there is a recess above the two electrodes. As a passivation film, a silicon nitride film or the like is formed using a CVD method or the like, whereby a sealing body made of an inorganic thin film can be formed, or these can be combined.

  By performing the above steps, an organic EL device can be produced using the present invention.

  Examples of the present invention will be described. In addition, this invention is not limited to an Example, The improvement, deformation | transformation, etc. in the range which can achieve this invention do not deviate from the meaning of this invention.

<Example 1>
(Preparation of photosensitive resin letterpress)
42 nickel material of 250 μm thickness was used as a relief printing plate base material, and an acrylic binder resin solution kneaded with a black pigment was applied on the base material so that the dry film thickness was 10 μm and dried.
An antireflection layer was formed.

  Mainly water-soluble polyamide, dipentaerythritol hexakisacrylate as radical polymerizable monomer, 2,2-dimethoxy-1,2-diphenylethane-1-one as photopolymerization initiator (manufactured by Ciba Specialty Chemicals) The photosensitive resin composition obtained by kneading the resin is melt-coated on the surface of the substrate so that the total thickness of the plate material is 310 μm as a photosensitive resin layer, and the polyvinyl alcohol solution has a dry film thickness of 1 μm. A polyethylene terephthalate film (film thickness 125 μm: manufactured by Teijin DuPont Films Ltd.) was laminated.

  The resin relief plate was exposed using a synthetic quartz substrate chromium mask as the original plate of the resin relief pattern, and this mask was set in a proximity exposure apparatus to produce a stripe pattern relief. The width of the produced convex pattern is 25 μm, and the pitch of the convex pattern is 150 μm.

(Preparation of printed substrate)
As a substrate to be printed, a thin film transistor functioning as a switching element provided on a support, a planarization layer formed on the information, and a pixel electrode that is connected to the thin film transistor by a contact hole in the form of a planarization layer An active matrix substrate provided with One side of the pixel size is 150 μm square, and the size of the RGB sub-pixel is 50 × 150 μm.

  A partition wall was formed in such a shape as to cover the end portion of the pixel electrode provided on the active matrix substrate and partition the pixel. The partition is formed by applying a positive resist ZWD6216-6 manufactured by ZEON Corporation on the entire surface of the active matrix substrate with a spin coater so that the dry thickness is 2 μm, and then by photolithography in the short side direction of each adjacent subpixel. A partition wall having a line width of 25 μm and a line width of 75 μm was formed in the long side direction.

  A 1.5 wt% aqueous solution of poly- (3,4) -ethylenedioxythiophene / polystyrene sulfonic acid (PEDOT / PSS) was formed to a thickness of 100 nm as a hole transport layer on the pixel electrode by spin coating. . Further, the PEDOT / PSS thin film thus formed was dried at 100 ° C. for 1 hour under reduced pressure to produce a substrate to be printed.

(Preparation of ink for forming an organic light emitting layer)
An organic light emitting ink was prepared by dissolving a polyphenylene vinylene derivative, which is an organic light emitting material, in anisole so as to have a concentration of 2%. The prepared ink has a viscosity of 60 mPa · s and a surface tension of 34 mN / m.

(Printing process)
As the relief printing apparatus, the one shown in FIG. 2 was used. The relief plate produced above was fixed to the plate cylinder of the relief printing apparatus. Next, the organic light emitting ink is supplied to the ink chamber, a part of the inking roll is immersed in the ink, the ink liquid film on the inking roll is brought into contact with the anilox roll, and the ink is supplied into the anilox roll cell. went. After the excess ink on the anilox roll was scraped with a doctor, the ink was inked into the convex part of the relief printing plate. At this time, the distance between the inking roll and the anilox roll was set to 0.5 mm.

  As the inking roll, a φ20 mm rubber roll in which urethane rubber was wound around a core roll made of SUS material or the like was used. The surface tension of the roll is 40 mN / m.

  As an anilox roll, a φ80 mm chromium plating roll was used. The formed pattern is a square pattern in which a square cell having a side of 65 μm is formed at a pitch of 72.5 μm, and these patterns are inclined by 60 ° from the roll horizontal line.

  The inked relief was pressed against the printing substrate and rolled to print a stripe pattern on the printing substrate. Printing was performed continuously to produce a total of 20 organic EL elements. After printing, it was dried in an oven at 130 ° C. for 1 hour.

  After drying, 10 nm of calcium was formed on the organic light emitting layer formed by printing, and then silver was vacuum-deposited by 300 nm thereon, and finally sealed using a glass cap to produce an organic EL device.

<Example 2>
A device was produced in the same manner as in Example 1 except that a chrome-plated roll was used for the inking roll and the interval between the inking roll and the anilox roll was 0.2 mm.

<Comparative Example 1>
A device was produced in the same manner as in Example 1 except that the ink was replenished by immersing the anilox roll in the ink in the ink chamber without using the inking roll.

<Comparative example 2>
A device was fabricated in the same manner as in Example 1 except that the anilox roll and the inking roll were in contact.

<Comparative Example 3>
An element was produced in the same manner as in Example 1 except that an anilox roll diameter and an inking roll diameter were both 80 mm.

<Evaluation>
The amount of ink used in Examples 1 and 2 and Comparative Examples 1 to 3, and the number of foreign materials and panel light emission unevenness of the fabricated elements were evaluated. The evaluation results are shown in Table 1 below. The evaluation of the number of foreign matters is based on observation of the number of foreign matters of 0.5 μm or more in the 20th panel surface.

<Comparison result>
From the comparison between Example 1 and Comparative Examples 1 and 3, by using the inking roll of the present invention and reducing the inking roll diameter, there is no light emission unevenness / coating unevenness of the device to be produced, and the ink to be used The result that the amount can be reduced was obtained.

  Further, from the comparison between Example 1 and Comparative Example 2, by not contacting the anilox roll and the inking roll, the ink can be stably circulated on the anilox roll even in continuous printing, and the number of foreign matters is small. It turns out that it is possible to suppress.

  Further, from Examples 1 and 2, it was found that the effect of the present invention can be obtained regardless of whether the material of the inking roll surface is resin, rubber or metal.

DESCRIPTION OF SYMBOLS 1 ... Stage 2 ... Board | substrate 3 ... Ink chamber 4 ... Doctor 5 ... Ink 6 ... Anilox roll 7 ... Plate cylinder 8 ... Letterpress plate 9 ... Inking roll DESCRIPTION OF SYMBOLS 10 ... Ink reservoir 12 ... Partition 13 ... 1st electrode 14 ... Hole transport layer 15 ... Red light emitting layer 16 ... Green light emitting layer 17 ... Blue light emitting layer 18 ... Second electrode 19: adhesive 20 ... glass cap 21 ... support 22 ... active layer 23 ... gate insulating film 24 ... gate electrode 25 ... transistor insulating film 26 ..Drain electrode 27... Flattening layer 28... Contact hole 29... Scanning line 30.

Claims (2)

A relief printing apparatus comprising a relief plate, a plate cylinder, an anilox roll, and an ink supply unit, the anilox roll having a function of supplying ink in contact with the convex portion of the relief plate mounted on the plate cylinder, The ink supply unit has a function of supplying ink to the anilox roll, and the ink supply unit includes an ink chamber having an ink reservoir structure and a diameter smaller than the ink chamber diameter therein. An inking roll, the inking roll diameter is smaller than the anilox roll diameter, the anilox roll and the inking roll are not in direct contact and have a gap, and between the anilox roll and the inking roll The inking roll rotates in a state immersed in ink, thereby An ink liquid level is formed on the upper part of the inking roll, ink is supplied to the anilox roll by contacting the ink liquid level formed on the upper part of the inking roll and the anilox roll, and the anilox roll and the ink liquid level A letterpress printing apparatus, wherein a doctor for removing excess ink inked in the direction of rotation of the anilox roll immediately after the contact position is installed on the anilox roll . 2. The relief printing apparatus according to claim 1 , wherein the surface tension of the inking roll is greater than or equal to the surface tension of the ink.