JP2005289034A - Resin composition for plate material and polymer printing plate using this resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polymer printing plate which has a cell successfully formed by a laser ablation process, shows excellent printing resistance and allows the prevention of static electricity and the control of surface hydrophilic/hydrophobic nature, a resin composition for printing plate as a raw material, specially a polymer material best-suited for cell formation using a laser with a short wave of not more than 370 nm. <P>SOLUTION: In the resin composition for a printing plate, it is possible to impart conductive properties without marring the original mechanical nature of a resin and at the same time, control its hydrophilic and hydrophobic natures by adding an organic salt compound to a resin material. In addition, when the resin material is ablation-processed using an ultraviolet laser light with a wavelength of not more than 370 nm by adding a pigment to the resin material, the successful formation of the cell by the laser light can be realized. Further, the resin composition preferably contains an organic compound which becomes a polyimide resin after polymerization, as a main component of the composition. Especially, the polyimide resin having a fluorene skeleton is best-suited as a resin for laser-processing type printing plate. Also, the polymer printing plate using the resin composition is provided. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a printing plate used for intaglio printing such as gravure printing, and more specifically, for a direct-drawing type polymer printing plate suitable for forming a recess by laser ablation, and a printing material used as a printing material for the polymer printing plate The present invention relates to a resin composition.

  Today, the demand for printing is increasing along with the high performance of computers and the spread of the Internet, and the demand for small lots, short delivery times, and low cost printing plates is increasing. In order to respond to such a flow, a method for producing a printing plate directly from desktop publishing (DTP) image data has been studied. In addition to the features such as low cost and short delivery time, the direct printing type printing plate is more There is an increasing demand for high resolution, high quality printing plates. Examples of such a direct drawing type printing plate include a plate using a photopolymer (Patent Document 1) (Patent Document 2) (Patent Document 3), a plate using a thermochemical reaction (Patent Document 4) (Patent Document 5). (Patent Document 6), a plate using a marking method (Patent Document 7) (Patent Document 8), and a plate using laser ablation have been proposed. However, both methods have advantages and disadvantages and still have many problems.

  As a method using laser ablation, that is, as an ablation method, a plate is usually produced by directly ablating a metal with a laser. However, with metal materials, there is a problem that metal swells around the hole formed by ablation and that strong laser light is required to form the hole, and in the actual process, the swelled part is cut after ablation. Done. However, this cutting process is not only complicated, but there is a problem in that shavings enter the hole during cutting and deteriorate the printing quality.

  In order to overcome such drawbacks, it has been studied to use a polymer as a plate material. A typical example of the polymer plate material for such a purpose is polyethylene, and a method of adding a hydrophilic substance to hydrophobic polyethylene has been proposed in order to improve the ink wettability. (Patent Document 9) Further, a method of adding carbon to a thermoplastic resin in order to increase the absorption efficiency of laser light has been proposed. (Patent Document 10) As an example of another polymer, a technique of thermally ablating a silicone resin with a high-energy laser beam is disclosed. This has a feature that development before and after writing is not necessary, but has a disadvantage that a cleaning step is required to remove a decomposition product. (Patent Document 11) Further, a method for producing a printing plate sheet by applying both a melamine curing agent and a urethane curing agent on a base polymer is disclosed. However, in spite of these proposals, laser ablation polymer printing plates are not yet in practical use due to the lack of a material that can realize the many conditions that the polymer printing plates should have in a well-balanced manner. Not reached.

  On the other hand, polymer laser ablation has been extensively studied in the field of printed wiring boards, and epoxy resins and polyimide resins are typical polymer materials. There has been disclosed a technique for ablating polyimide with a UV laser in order to form fine holes. (Patent Document 13) (Non-Patent Document 1) However, unlike a printed wiring board, a polyimide resin printing plate for laser ablation has a problem of high polymerization temperature, a problem of workability, and a problem of control of hydrophilicity / hydrophobicity. There is a problem of conductivity control.

  In gravure printing, after a printing ink is filled into a concave portion that has been narrowed by a laser, excess ink other than the concave portion is scraped off with a squeegee. In the ink filling process, it is important that the ink is sufficiently filled in the recesses, and in the squeegee scraping process, it is important that there is no remaining ink scraped. To that end, the hydrophilicity / hydrophobicity of the plate surface is controlled. Things are necessary. Further, in such a process, there is a problem that static electricity is generated between the squeegee and the printing plate, attracting peripheral dust and lowering the printing quality. For this reason, it is necessary for the printing plate resin to have at least a semiconductor-like conductivity for discharging static electricity.

  A general method for imparting semiconductivity to a resin is a method of blending a conductive filler such as conductive carbon black, metal powder, metal fiber, or carbon fiber with a synthetic resin that is an insulator. However, the semiconductive resin composition in which a general-purpose conductive filler is blended with a synthetic resin has (1) a volume resistivity that varies greatly even with a slight change in the filling amount of the conductive filler. There was a problem that the resistivity distribution was not uniform and the volume resistivity varied greatly depending on the location.

The main causes of such problems are that the volume resistivity of general-purpose conductive fillers is extremely small compared to synthetic resins, and the semiconductive expression is the state of dispersion of conductive fillers in the resin composition. It depends heavily on. If conductive fillers are dispersed in an independent state in a synthetic resin with a large volume resistivity, the volume resistivity of the resin composition will not be reduced to the desired level, and the conductive resin will be filled into the synthetic resin. When most of the materials are dispersed in a connected state, the volume resistivity decreases rapidly. Further, if the conductive filler is not uniformly dispersed in the resin, the volume resistivity varies depending on the location of the resin composition. On the other hand, it is known that the conductive filler generally tends to aggregate and it is extremely difficult to uniformly disperse the conductive filler in the resin. Furthermore, the dispersion state of the conductive filler greatly depends on the type, shape, filling amount, molding condition of the resin composition, and the like of the conductive filler relative to the synthetic resin. Therefore, it has been very difficult to stably produce a semiconductive resin composition having a volume resistivity of 10 ⁵ to 10 ¹⁵ Ω · cm with good reproducibility.

  As a method for avoiding the above problem, a method of controlling the resistance value by including an inorganic salt such as LiCl in the resin is disclosed (Patent Document 14). However, since inorganic salts are generally easy to dissolve in water, there is a problem that the resistance value of polyimide resins whose resistance value is controlled by addition of inorganic salts changes greatly due to the influence of outside air humidity.

Furthermore, when the semiconductive resin composition obtained by the method of blending the conductive filler is used as a printing plate by laser ablation, it is a big problem that the conductive filler scatters and contaminates the printing plate by ablation. Met.
Japanese Patent Laid-Open No. 04-219756 Japanese Patent Laid-Open No. 06-295061 Japanese Patent Application Laid-Open No. 08-220758 USP 5372907 JP 2002-229212 A JP 2003-11316 A Japanese Patent Laid-Open No. 09-11655 JP 09-581144 A JP 05-246165 A Japanese Patent Laid-Open No. 55-41297 USP 5632204 Japanese Patent Laid-Open No. 08-25824 USP 4568632 JP 2001-354882 A K. Jain et al, “Ultrafast Deep UV Lithography with Excimer Laser” IEEE Electron Device Letters vol 3, EDL-3, No. 1 3, Mar. 1982, pp 53-55.

  The present invention relates to a polymer material for a simple printing plate suitable for a laser ablation method and a method for producing the same. As a material for an intaglio printing plate, it is important that good holes (recesses) can be formed by a laser. In a gravure plate used for gravure printing which is intaglio printing, this hole is called a cell and is a unit for forming an image. In order to obtain a high-resolution printed matter, the pixels need to be as small as 20 μm to 5 μm. For this purpose, it is suitable to use a short wavelength laser (UV laser) having a wavelength of 370 nm or less. An object of the present invention is to provide a polymer material suitable for such a purpose.

The printing plate material further needs to have printing resistance. The printing durability is printing durability that does not wear or deform due to the rubbing of the plate due to ink scraping with a squeegee when printing is repeated. In the case of laser polymer printing plates, the printing durability is not as high as that of metal plates.
Still, it is desirable to have a printing durability of at least about 1000 sheets, desirably 2000 sheets or more. Therefore, specifically, for printing durability, it is necessary to be a polymer material having excellent mechanical strength and elastic modulus. Further, as described above, it is necessary to control the hydrophilicity and hydrophobicity of the surface of the polymer material in order to realize excellent ink filling properties and transferability corresponding to various inks. Furthermore, it is desirable to have conductivity in the semiconductor region in order to smoothly remove static electricity generated by friction with the squeegee.

  The problem to be solved by the present invention is due to the difficulty of precise control of the filling amount that has occurred in the conventional methods of blending conductive fillers such as conductive carbon black, metal powder, metal fiber, and carbon fiber. Resin for printing materials that can stably control the hydrophilicity / hydrophobicity of the surface while maintaining the conductivity of the semiconductor region without causing the conductive resin state and temporal and spatial variations of the printing material. It is to provide a composition and a polymer printing plate using the composition.

  Further, since the printing plate is usually used in the form of a roller or a flat plate, it is necessary to form a plate layer with a certain thickness on the surface of a metal substrate such as aluminum or stainless steel. That is, it is necessary for such a printing plate polymer material to be easily processed. Accordingly, a further object of the present invention is to provide a polymer printing plate capable of forming a plate material layer with a certain thickness on the surface of such a metal substrate.

The present invention relates to a resin composition for a plate material containing an organic salt compound, and a printing plate having a plate material formed using it as a raw material, that is, a polymer printing plate containing an organic salt compound.
By adding an organic salt compound, it is possible to stably impart conductivity to the plate material layer without impairing the original mechanical properties of the resin, and at the same time control the hydrophilicity / hydrophobicity of the plate material layer. The resin can be preferably used as a printing plate resin.

  When a dye is further added to the resin composition for a plate material of the present invention, laser light can be efficiently absorbed when a polymer printing plate is obtained, so that it is preferable because a laser plate making having good cells is obtained. Here, the coloring matter used in the present invention includes a pigment or a dye as a concept.

The plate material of the polymer printing plate of the present invention preferably has a volume resistance value controlled in the range of 10 ³ to 10 ¹⁵ Ωcm, and the squeegee and the printing are adjusted by adjusting the resistance value to such a range. The generation of static electricity with the plate can be effectively suppressed.

  Further, the plate material of the polymer printing plate of the present invention preferably has a tensile elastic modulus of 3 GPa or more because it has sufficient printing resistance.

  In order to make the volume resistance value in the above range and to make sufficient mechanical properties evaluated by the tensile modulus of elasticity of the plate material, the organic salt compound and 100 parts by weight of the resin composition, It is preferable that the addition amount of the pigments combined is 0.01 to 30 parts by weight.

The anion and cation constituting the organic salt compound are selected from an anion having an SO ₃ ^- group, an anion having a COO ^- group, a fluorine-containing anion, and a fluoroalkylsulfuric acid as an anion. It is preferable that at least one selected from pyridine, alicyclic amine, and ammonium salt is included because it can be dispersed in a molecular form in the resin composition. In particular, organic salt compounds composed of these anions and cations can be favorably dispersed in a polyimide resin, and the resistance value of the plate material can be easily controlled.

  The present invention also relates to a resin composition for a plate material containing an organic salt compound and containing as a main component an organic compound that is polymerized into a polyimide resin, and the resin composition as a plate material Relates to the polymer printing plate.

  In addition, the present invention relates to a polymer printing plate using a polyimide resin composition containing an organic salt compound as a plate material. By using a polyimide resin as a printing plate material, it is possible to form good holes (cells) by laser light. Become.

  Furthermore, by adding an organic salt compound to the polyimide resin, the electrical resistance value as a plate material can be further increased while retaining the properties such as excellent laser processability, heat resistance, mechanical strength, and elastic modulus of the polyimide resin. Can control the surface properties, that is, the degree of hydrophilicity / hydrophobicity. That is, when the main component of the resin composition constituting the plate material of the polymer printing plate of the present invention is a polyimide resin, the polymer printing plate has excellent heat resistance, mechanical strength and elastic modulus, and the tensile elastic modulus Is 3 GPa or more, which is preferable because it can satisfy the demand for printing resistance.

  The polymer printing plate of the present invention can form good holes (concave portions), particularly even when ablation is performed with laser light (ultraviolet laser light) having a wavelength shorter than 370 nm (wavelength of 370 nm or less), High resolution printing is possible.

  The polymer printing plate of the present invention is preferably formed as the plate material formed on a metal substrate.

  As a method for forming a plate material on a metal substrate, the resin composition for a plate material mainly composed of a polyimide resin is formed into a film shape and attached to a metal substrate or a roll through an adhesive layer. There is a way. When the main component of the resin composition for a plate material is an organic solvent-soluble or thermoplastic polyimide resin raw material, it is possible to easily form and process a plate material layer on a metal roller or a flat substrate. This is preferable. In the case of an organic solvent-soluble polyimide resin, a plate material layer can be easily formed by applying and drying a polyimide solution, which is more preferable. In the case of a thermoplastic polyimide resin, a plate material layer that is a resin layer can be easily formed by heat fusion or thermocompression bonding even after imidizing the resin composition for a plate material on a metal substrate or roll. It is formed.

  The present invention also relates to a resin composition for a plate material containing an organic salt compound and containing as a main component an organic compound that is polymerized to become a polyimide resin, and the resin composition as a plate material The present invention relates to a polymer printing plate. Therefore, it is also possible to apply a polyimide precursor on a metallic roller or a flat substrate. In that case, after applying in the state of a polyimide precursor, imidization and drying can be continued.

  Whichever method is used to form the polymer printing plate of the present invention, it is preferable because the plate layer can be formed with a constant thickness on the surface of the metal substrate.

  The polymer printing plate having a plate material formed by using the resin composition for a plate material of the present invention can control conductivity and surface hydrophilicity / hydrophobicity as a printing plate for intaglio printing such as gravure printing. It is easy and is excellent in printing durability. Furthermore, since a good cell can be formed by the laser ablation method, the polymer printing plate of the present invention can be effectively used as a laser printing plate, and in particular, laser light (ultraviolet light having a wavelength shorter than 370 nm (wavelength of 370 nm or less)). Even when ablation processing is performed with a laser beam, good cells can be formed and high-resolution printing can be performed. This method can produce a printing plate directly from desktop publishing (DTP) image data, and can meet the demand for a small lot, short delivery time, low cost, and high-definition printing plate.

  In addition, since this laser printing plate directly processes a polymer resin, development, copper etching, resist removal, and chrome plating steps that are performed in a laser gravure plate making method using a conventional photoreceptor are unnecessary. High-speed and low-cost production of gravure plate can be realized.

  Furthermore, when the polymer printing plate of the present invention has a plate material layer formed on a metal substrate, it can be easily formed into a plate material layer having a constant thickness, and high quality polymer printing It becomes a version.

  First, we conducted cell formation experiments of various polymer materials using the third harmonic (355 nm) of a pulsed YAG laser. Polyacetals (formalin-ethylene oxide copolymer type), polybutylene terephthalate (PBT), modified polyphenylene ether (PPE), polyparaphenylene sulfide (PPS), polyetheretherketone (polyether ether ketone) are suitable resins for cell formation under such conditions. PEEK), polyparaphenylene terephthalamide, polyimide, urethane, and novolac type phenolic holymarin resin can be preferably used, and polyimide and PPS are particularly preferably used. On the other hand, polycarbonate, polysulfone, polyester resin, and polyethylene naphthalate are transparent resins and have low laser light absorption efficiency and are not suitable for cell formation. However, it is possible to make holes by adding pigments or carbon.

As described above, when a polyimide resin is used as the main component of the plate material of the present invention, the best cell free from scattering and burning residue (smear) can be formed. Usually, a polyimide resin is often a thermosetting type, but a thermoplastic polyimide resin can be obtained by a molecular structure. From the viewpoint of the cell formation by laser, a good cell can be formed by either thermosetting polyimide resin or thermoplastic polyimide resin, which can be preferably used for the purpose of the present invention.

  In order to complete the present invention, it is further essential that the glass transition temperature of the polyimide resin is preferably 250 ° C. or higher, more preferably 300 ° C. or higher. This is because there is no fusion adhesion of the resin decomposed by irradiation near the laser hole during laser processing.

  There are cases where the resin for printing plate is used as a flat plate and where a resin layer, that is, a plate material layer is formed on a metal roll. When the plate material mainly composed of a thermosetting polyimide resin is used as a flat plate type or a roll type plate, the plate material is formed in a film shape in advance, and the metal plate is a metal flat plate or metal. It is preferable that the roll is used by bonding with an adhesive.

  On the other hand, when a thermoplastic polyimide resin is the main component, an adhesive is not always necessary, and a film-like plate material may be heat-pressed on the substrate. Further, when the solvent-soluble polyimide resin is a main component, the plate material layer may be formed by coating the substrate in a state dissolved in an organic solvent and drying it to remove the organic solvent. Therefore, a thermoplastic polyimide resin or an organic solvent-soluble polyimide resin is preferable as a main component after polymerization of the resin composition for a plate material of the present invention.

  The polyimide resin according to the present invention will be described below.

  The polyimide resin of the present invention can be produced by a known production method. That is, one or more tetracarboxylic dianhydride components as raw materials and one or more diamine components are used in substantially equimolar amounts and polymerized in an organic polar solvent to form a polyamic acid polymer. This is a method of obtaining a solution and imidizing polyamic acid which is a precursor of this polyimide resin.

  For this imidization, either a thermal cure method or a chemical cure method is used.

  The thermal cure method is a method in which an imidization reaction proceeds by heating alone without the action of a dehydrating ring-closing agent or the like. Specifically, it is cast onto a support such as a glass plate or stainless steel belt, and after the reaction has progressed to the extent that it has self-supporting properties, it is peeled off from the support, and the end is fixed with a pin or clip. And further imidized by further heating.

  In addition, the chemical cure method includes a polyamic acid organic solvent solution, a chemical conversion agent (dehydrating agent) represented by acid anhydrides such as acetic anhydride, and tertiary amines such as isoquinoline, β-picoline, and pyridine. And a catalyst represented by the above. It is also possible to use a carbodiimide compound such as dicyclohexylcarbodiimide as a dehydrating agent. Of course, the thermal cure method may be used in combination with the chemical cure method, and the imidation reaction conditions vary depending on the type of polyamic acid, the form of the resin obtained, the thermal cure method, and / or the selection of the chemical cure method. obtain.

  Preferred solvents for synthesizing the polyamic acid are amide solvents, ie N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone and the like, and N, N-dimethylformamide is particularly preferred. Preferably used.

  Known tetracarboxylic dianhydrides can be used as the tetracarboxylic dianhydride component used in the production of the polyamic acid polymer. Specifically, pyromellitic dianhydride, 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride, 3,3 ′, 4,4′-diphenylsulfone tetracarboxylic dianhydride, 1 , 4,5,8-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 4,4′-oxydiphthalic anhydride, 3,3 ′, 4,4 ′ -Dimethyldiphenylsilane tetracarboxylic dianhydride, 3,3 ', 4,4'-tetraphenylsilane tetracarboxylic dianhydride, 1,2,3,4-furantetracarboxylic dianhydride, 4,4 '-Bis (3,4-dicarboxyphenoxy) diphenylpropane dianhydride, 4,4'-hexafluoroisopropylidene diphthalic anhydride, 3,3', 4,4'-biphenyltetracarboxylic acid Things, 2,3,3 ', 4'-biphenyltetracarboxylic dianhydride, p- phenylenediamine aromatic such as phthalic anhydride tetracarboxylic dianhydride, etc. are exemplified.

  On the other hand, known diamines can be used as typical diamine components used in the production of the polyamic acid polymer. Specifically, 4,4′-diaminodiphenyl ether, 3,4′-diaminodiphenyl ether, 2,2-bis (4-aminophenoxyphenyl) propane, 1,4-bis (4-aminophenoxy) benzene, 1, 3-bis (4-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, bis (4- (4-aminophenoxy) phenyl) sulfone, bis (4- (3-aminophenoxy) phenyl) Sulfone, 4,4′-bis (4-aminophenoxy) biphenyl, 2,2-bis (4-aminophenoxyphenyl) hexafluoropropane, 4,4′-diaminodiphenyl sulfone, 3,3′-diaminodiphenyl sulfone, 9,9-bis (4-aminophenyl) fluorene, bisaminophenoxyketone, 4 4 ′-(1,4-phenylenebis (1-methylethylidene)) bisaniline, 4,4 ′-(1,3-phenylenebis (1-methylethylidene)) bisaniline, m-phenylenediamine, p-phenylenediamine, 4,4′-diaminobenzanilide, 3,3′-dimethyl-4,4′-diaminobiphenyl, 3,3′-dimethoxy-4,4′-diaminobiphenyl, 3,3′-dimethylbenzidine, 3,3 Examples include aromatic diamines such as' -dihydroxybenzidine, and other aliphatic diamines.

  The combination of the tetracarboxylic dianhydride component and the diamine component described here shows one specific example for obtaining a polyimide resin which is the main component of the plate material of the present invention. It is possible to adjust the polyimide resin raw material as the main component of the resin composition for a plate material of the present invention by changing the combination and use ratio of the tetracarboxylic dianhydride component and the diamine component to be used without being limited to these combinations. is there.

In addition, the organic compound which polymerizes and becomes a polyimide resin of the present invention is used for the production of a polyamic acid polymer, which is a polyimide resin precursor, shown as a specific example for obtaining a polyimide resin as described above. Be
A compound comprising at least one selected from the tetracarboxylic dianhydride components described above, and
A compound containing at least one selected from the diamine components described above. However, it is not limited to the combination of these specific examples, the combination of the tetracarboxylic dianhydride component and the diamine component to be used and the use ratio are changed, and the polymerization is performed as the main component of the resin composition for a plate material of the present invention. It is possible to adjust the resin composition for a plate material by selecting an organic compound to be a polyimide resin.

  Next, a thermoplastic polyimide resin or an organic solvent-soluble polyimide resin will be described. The thermoplastic polyimide here is a resin having a glass transition temperature, unlike the non-thermoplastic polyimide.

  Examples of the polyimide resin, thermoplastic polyimide resin, or organic solvent-soluble polyimide resin obtained by polymerization from the resin composition for a plate material of the present invention include the following formula (9)

（式中、Ａ、Ｂはそれぞれ４価の有機基、Ｘ、Ｙはそれぞれ２価の有機基を示す）、で表されるポリアミド酸を脱水閉環して得られるポリイミドが好ましく、
式（９）中のＡ、Ｂが下記群（１）に示す４価の有機基から選択される一種類または二種類以上であることがより好ましく、

(Wherein, A and B are each a tetravalent organic group, and X and Y are each a divalent organic group), and a polyimide obtained by dehydrating and ring-closing a polyamic acid represented by
More preferably, A and B in the formula (9) are one type or two or more types selected from tetravalent organic groups shown in the following group (1):

また、前記式（９）中のＸ、Ｙは下記群（２）に示す２価の有機基群から選択される一種または二種以上であることがより好ましい。

Moreover, it is more preferable that X and Y in the formula (9) are one type or two or more types selected from a divalent organic group group shown in the following group (2).

本発明の版材用樹脂組成物から重合により得られる熱可塑性ポリイミド樹脂あるいは有機溶媒可溶性のポリイミド樹脂としては、これら酸二無水物とジアミンの組み合わせの中で、上記の群（１）に挙げた酸二無水物残基を与える酸二無水物から選ばれた少なくとも一種の酸二無水物と、上記の群（２）に挙げたジアミン残基を与えるジアミンから選ばれた少なくとも一種のジアミンの組み合わせから得られるものが好ましい。

The thermoplastic polyimide resin or organic solvent-soluble polyimide resin obtained by polymerization from the resin composition for plate material of the present invention is listed in the above group (1) among the combinations of these acid dianhydrides and diamines. A combination of at least one acid dianhydride selected from acid dianhydrides giving acid dianhydride residues and at least one diamine selected from diamines giving diamine residues listed in the above group (2) Those obtained from are preferred.

  Among them, 2,3,3 ′, 4′-biphenyltetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, oxydiphthalic anhydride, α -Oxydiphthalic anhydride, ethylene bis (trimellitic acid monoester acid anhydride), bisphenol A bis (trimellitic acid monoester acid anhydride), 4,4 '-(4,4'-isopropylidenediphenoxy) bis (Phthalic anhydride) and 1,3-diaminobenzene, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 1,3-bis (3-aminophenoxy) benzene, 1,3-bis as diamine (4-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, 2,2-bis [4- (4-amino Phenoxy) phenyl] propane, 4,4′-bis (4-aminophenoxy) biphenyl, bis [4- (4-aminophenoxy) phenyl] sulfone, etc. are industrially available and the resulting polyimide resin Is particularly preferred for the purposes of the present invention because of its low water absorption and excellent elastic modulus.

  It is recognized that polyimide resins are generally solvent-insoluble, and their improvement is a major technical problem. Therefore, the knowledge that solvent solubility can be realized by introducing a flexible and flexible chemical structure has been known, but along with this, a trade-off relationship in characteristics that damages heat resistance (if one tries to improve either On the other hand, it is also known that one of them becomes worse, a conflicting relationship).

  In particular, the present invention relates to a laser processing type printing plate according to one embodiment, and in the gravure printing application, since it is one of the best modes that a resin can be applied to a gravure printing roll, high solvent solubility is desired. There is a demand for heat resistance that is rare and does not deform with the amount of heat at the time of laser processing.

  However, because of the conflicting technical demands as described above, it was predicted that it would be difficult to achieve both.

  As a result of various studies, it was discovered that the fluorene structure satisfactorily balances its organic solvent solubility and heat resistance characteristics, and in one embodiment, the present invention has been completed. Although more detailed academic studies are required for the expression mechanism, it can be estimated that the twisted structure of the fluorene residue contributes to the solubility and the polycyclic benzene structure contributes to the heat resistance.

  In the present invention, the thickness of the printing plate layer, which is a plate layer mainly composed of polyimide, is preferably 5 μm to 125 μm, and more preferably 10 μm to 50 μm. The tensile elastic modulus is 3 GPa or more, preferably 4 GPa or more, more preferably 5 GPa or more. The water absorption is 2% or less, preferably 1.5% or less, more preferably 1% or less. The elastic modulus (tensile elastic modulus) according to the present invention can be measured by the ASTM D882 method.

  Polyimide resin is strong and wear-resistant, so it can withstand sliding contact with the doctor blade even if the surface of the plate layer composed mainly of polyimide resin is used as it is. The printing plate can be applied to printing. The elastic modulus is the most important physical property that determines the printing durability of the polymer printing plate. In general, the polyimide resin has a high elastic modulus, so that the polyimide resin is preferably used.

  The coloring matter used in the present invention includes a pigment or dye as a concept, and has no limitation as long as it can be added to efficiently absorb laser light. For example, pigments classified as azo, condensed polycyclic, or phthalocyanine, and dye-based pigments can be exemplified. In the present invention, when a dye soluble in an organic solvent is used, the dye can be easily molecularly dispersed in the organic solvent and in the resin, and variation in the laser light absorption efficiency in the resin is suppressed. . In addition, since the dye is generally insoluble in water, for example, a polyimide resin containing the dye has an advantage that the fluctuation due to the influence of the outside air humidity is extremely small.

  Next, a technique for imparting semiconductivity to a plate material of a polymer printing plate according to the present invention, particularly a plate material mainly composed of a polyimide resin, and simultaneously imparting hydrophobicity / hydrophilicity to the surface of the plate material explain.

  As described above, the reason why the resin for the printing plate needs to be semiconductive is to suppress static electricity generated when the excess printing ink is scraped off with a squeegee in gravure printing. The generation of static electricity not only lowers the print quality by adsorbing surrounding dust, but also causes the smooth transfer of printing ink to paper or plastic.

  In the present invention, a method of forming a plate material using a resin composition for a plate material to which an organic salt compound is added in order to impart conductivity to the plate material is used.

The organic salt compound is a salt characterized in that at least one of a cation and an anion constituting the organic salt compound is an organic ion. Since the organic salt compound generally has high ionic conductivity, the resistance value in the semiconductor region can be controlled by including it in the resin. Since most organic salt compounds are soluble in organic solvents, organic salt compounds can be easily molecularly dispersed in organic solvents and resins, and the addition of organic salt compounds provides semiconductivity. With such a resin, temporal and spatial variations in resistance value are suppressed. Moreover, since an organic salt compound is generally insoluble in water, a polyimide resin containing an organic salt compound further has an advantage that a change in its resistance value due to outside air humidity is extremely small.

The organic salt compound according to the present invention is recognized in the light of general expertise of those skilled in the art, as shown in (Non-patent Document 2) supervised by Hiroyuki Ohno, “Ionic Liquid” CMC Publishing (2003). Any organic salt compound according to the present invention can be used as long as it can be obtained. For example, in the organic salt compound according to the present invention, at least a part of the anion forming the compound is p-CH ₃ C ₆ H ₄ SO ₃ ⁻ , C ₆ H ₅ SO ₃ ^-, such as, SO ₃ ^- a sulfonic acid series anions having a group, or COO ^- anion having a group, fluorine-containing anions, fluoroalkyl sulfate, it is preferred that.

Examples of the anion forming the organic salt compound include fluorine-based compounds such as BF ₄ ⁻ , PF ₆ ⁻ , (CF ₃ SO ₂ ) ₂ N ⁻ and CF ₃ COO ⁻ , and non-fluorine halogen compounds such as Cl ⁻ and Br ^−. Etc. are known. Compared to these anions, organic salt compounds formed from an anion having an SO ₃ ^- group or an anion having a COO ^- group have extremely high compatibility with the resin, and also have conductivity to the resin. Since the ability to impart resistance is extremely high, it is possible to realize strict control of the resistance value and excellent resistance value reproducibility.

Since an organic salt compound having a fluorine-based anion has low compatibility with a resin, there is a problem that the resin to which the organic salt compound is added has a large variation depending on the location of its resistance value. However, fluorine-based anions are the most suitable organic salt compounds for controlling the hydrophobicity of the resin surface, and they are electrically conductive when used in combination with an anion having a SO ₃ ^- group or an anion having a COO ^- group. And can control the hydrophobicity of the surface.

Specific examples of the anion having an SO ₃ ^- group include benzenesulfonic acid, toluenesulfonic acid, alkylbenzenesulfonic acid, naphthalenesulfonic acid, alkylnaphthalenesulfonic acid, anthraquinonesulfonic acid, polyvinylsulfonic acid, metasulfonic acid, and alkylsulfone. An acid etc. can be illustrated. Among them, benzenesulfonic acid and paratoluenesulfonic acid are preferably used for this purpose because they give an organic salt compound having a high conductivity-imparting ability.

On the other hand, COO ^- as an anion having a group ^{RCOO -, - OOCRCOOH, - OOCRCOO} -, NH 2 CHRCOO - can be exemplified. Specifically, it is effective to synthesize organic salt compounds using formic acid, acetic acid, maleic acid, adipic acid, oxalic acid, phthalic acid, succinic acid, amino acids and the like.

  Further, an organic salt compound having fluoroalkylsulfuric acid as an anion can be obtained by directly synthesizing from a halogen compound having a corresponding cation component using fluorinated ammonium sulfate as a starting material.

  The organic salt compound according to the present invention is also a diionic organic salt compound in which both a cation and an anion are fixed in the same molecule, and an organic compound having a cation moiety and / or an anion moiety in the side chain. It may be a salt polymer.

  Specific examples of cations forming organic salt compounds include pyridines such as methylpyridinium and butylpyridinium, alicyclic amines such as ethylmethylimidazolium, propylmethylimidazolium and methylpyrazolium, and hexyltrimethylammonium. Examples thereof include aliphatic amines.

  Among these, considering the thermal stability, conductivity, and compatibility with the polyimide resin of the organic salt compound, the cation forming the organic salt compound contains at least one selected from pyridine and alicyclic amines. It is preferable. As used herein, the term “pyridine-based” refers to those having a pyridine derivative in the molecular structure, and specific examples include methylpyridinium and butylpyridinium.

  Moreover, an alicyclic amine type | system | group refers to what has an imidazole derivative or a pyrazole derivative in molecular structure, for example, ethylmethylimidazolium, dimethylimidazolium, and methylpyrazolium are mentioned.

  Further, the ammonium salt type refers to those having an ammonium salt structure in the molecular structure, and specific examples include tetramethylammonium, dimethylethylbenzylammonium, anilinium, dimethylammonium and the like.

Specific examples of the organic salt compounds, for example, ethyl methyl imidazolium _{· p-CH 3 C 6 H} 4 SO 3 - salt, butyl methyl imidazolium · C ₆ H ₅ SO ₃ ^- salts.

  If the amount of the organic salt compound and / or pigment contained in the plate resin composition is small, the effect may not be sufficiently exhibited. Conversely, if the amount is too large, polymerization may be performed from the plate resin composition. The mechanical and mechanical properties inherent to the obtained plate material may be reduced. Therefore, it is preferable that the organic salt compound and / or the pigment is contained in an amount of 0.01 to 30 parts by weight, more preferably 0.1 to 20 parts by weight, based on 100 parts by weight of the resin composition for a plate material. It is that.

In the plate material according to the present invention, it is important that the volume resistivity after forming the plate material layer is at least in the semiconductor region, and a preferable range of the volume resistivity is from 10 ³ Ω · cm to 10 ¹⁵ Ω · cm. . For the purpose of removing static electricity, a resistivity of 10 ³ Ω · cm or less is not required, and a volume resistivity of 10 ¹⁵ Ω · cm or more cannot achieve the purpose of removing static electricity. The volume resistivity according to the present invention can be measured according to JIS K6911.

  In addition to the organic salt compound, the resin composition for a plate material of the present invention can contain various fillers depending on the purpose such as mechanical properties, hardness adjustment, and improvement of slipperiness. Examples of such fillers include carbon, graphite, polyamide resin, fluororesin, polyester resin, acrylic resin, ABS resin, polyphenylene sulfide, polyether ether ketone, polyether ketone, polyphenylene sulfide ketone, polyvinyl chloride, and polyvinylidene chloride. , Fibrous and granular (including powder and plate-like) fillers such as polycarbonate, modified polyphenylene ether, polyurethane, polydimethylsiloxane, polyvinyl acetate, polystyrene, and high melting point organic fibrous materials such as polymethyl acrylate. be able to. These fillers can be used alone or in combination of two or more. These fillers are used in the resin composition in a proportion of 0 to 50% by mass, preferably 0 to 30% by mass.

  For gravure printing, various inks such as oil-based ink and aquatic ink are used. Therefore, it is necessary to control the hydrophilicity / hydrophobicity of the resin in accordance with the properties of the ink. As described above, such control of hydrophilicity and hydrophobicity can be realized by selecting the kind of organic salt compound and / or dye used in the present invention.

  When forming a gravure plate for performing gravure printing using oil-based ink, the plate material is formed so that the surface of the plate material mainly composed of polyimide resin has oil repellency, and laser light is applied to the plate material layer. It is preferable to dig the plate material layer portion by scanning while irradiating the image area, and when forming a gravure plate suitable for water-based ink use, a plate material mainly composed of polyimide resin It is preferable that the plate material is formed so that the surface of the plate material has hydrophobicity and scanned while irradiating the image line portion on the plate material layer to dig the plate material layer portion.

  The polymer printing plate of the present invention is particularly suitable for ablation processing with an ultraviolet laser beam having a wavelength of 370 nm or less. Since bonds such as C—C bond, C—O bond, and C—N bond are separated by such a wavelength, for example, an ultraviolet laser beam having a wavelength of 355 nm leaves a cell substantially corresponding to the shape of the laser beam (smear). Without piercing. The diameter of the cell is almost determined by the shape of the laser beam, and usually a cell with a diameter of about 20 μm is formed. In particular, by using an ultraviolet laser light source, a single cell with a small diameter suitable for high resolution can be obtained. This is possible with the polymer printing plate of the invention. It goes without saying that larger cell processing and line processing are possible by continuously drilling these cells. The depth of the hole is substantially proportional to the number of irradiation pulses of the ultraviolet laser to be irradiated, and the proportionality constant depends on the pulse energy.

  As an ultraviolet laser light source, it is possible to use a krypton or argon ion laser in the 360 nm wavelength region, or a YAG laser 4th harmonic laser (266 nm) having a shorter wavelength.

  A conceptual diagram of a laser printing plate manufacturing apparatus is shown in FIG. Using the laser printing plate manufacturing apparatus shown in FIG. 1, cells are formed on a plate material by irradiating a laser beam from a laser irradiation apparatus, and the formed cells can be observed with an electron microscope to be used as a printing plate. Evaluated. Furthermore, printing was repeated using the finished plate to evaluate printing durability.

  In FIG. 1, reference numeral 1 denotes an ultraviolet laser light source that emits ultraviolet laser light having a wavelength of 355 nm, which is the third harmonic of a YAG laser. In the case of the evaluation device, one pulse is 100 nJ and the repetition frequency is 80 MHz. Reference numeral 2 denotes a beam shaping irradiation unit for shaping the ultraviolet laser into a predetermined beam shape. Reference numeral 3 denotes a control unit that relates plate making information to the light source 1, the beam shaping irradiation unit 2, and the plate cylinder 5, and 4 denotes a polyimide type plate material 4 mounted on the surface of the metal roll 5. In the beam shaping irradiation unit, the incident laser light is finely focused by the aperture shaping unit and enters the acousto-optic light modulation unit. This light modulation unit can modulate the light intensity at about 10 MHz, and can modulate the intensity of the diffracted light by the modulation signal from the control unit 3 to which the plate making information is given. The diffracted light emitted from the light modulating unit is incident on the projection optical unit as intensity-modulated pulse light, and is shaped so as to have a predetermined beam diameter on the plate material surface by the reduction projection lens system.

  Next, the resin composition for a plate material and the polymer printing plate according to the present invention will be described in detail with reference to examples.

(Example 1)
In a vessel equipped with a stirring blade, 1500 g of dimethylformamide (DMF) sufficiently dehydrated with molecular sieves was added, 200 g of 4,4′-diaminodiphenyl ether was added, and the mixture was stirred until completely dissolved. The system was cooled to 0 ° C. and 218 g of pyromellitic dianhydride was gradually added and stirred well. When the viscosity of the system reached about 3 × 10 ² Pa · s, stirring was stopped to obtain a polyamic acid solution. 0
Next, 5 g of an organic salt compound formed from ethylmethylpyridinium, which is a pyridine cation, p-CH ₃ C ₆ H ₄ SO ₃ ^—, and 1.4 g of cyanine blue KROS manufactured by Sanyo Dye Co., Ltd., which are dyes, Collected in a beaker. In this beaker, 300 g of the polyamic acid solution obtained above was dissolved. Thus, the resin composition which contains about 10 weight part of mixture of an organic salt compound and a pigment | dye with respect to 100 weight part of polyimide resins after hardening was prepared. Further, 20 g of isoquinoline as a catalyst and 32 g of acetic anhydride as a dehydrating agent were kneaded with the above solution.

  The resin composition containing the organic salt compound, dye, catalyst and dehydrating agent obtained above was applied on a roll having an outer diameter of 200 mm and a length of 1000 mm, and then the applied film was heated from 100 ° C. to 380 ° C. for about 30 The temperature was raised over a period of minutes. Finally, the system was cooled to room temperature to obtain a polyimide printing plate. The thickness of the polyimide resin layer is 30 μm.

  In the same manner as the plate material of the obtained polymer printing plate, a polyimide molded body having the same thickness was separately formed, and its volume resistivity measurement and tensile elastic modulus measurement were performed. The polyimide molded body was prepared by applying the resin composition on an aluminum foil, and removing the aluminum foil by etching after heat treatment. In addition, formation of recesses on the plate material surface by the laser irradiation apparatus consisting of 1 to 3 in FIG. 1, its observation, and printing durability evaluation by model experiments were performed.

The volume resistivity measurement was performed according to the following procedure. A test piece of 10 cm × 10 cm × 30 μm was cut out from the obtained polyimide molded body, and the volume resistivity of the test piece was measured using a resistance measuring device R8302 manufactured by Advantest Corporation. As a result, the volume resistivity was 6 × 10 ⁹ Ω · cm. Moreover, the tensile elastic modulus was 4.2 GPa.

  As a result of performing an electron microscope on the cells on the plate material perforated with a laser, a cell having a diameter of 10 μm at the upper surface of the plate material surface of the cell and a depth of 8 μm was formed by irradiation with three shots. The shape of the cross section of the plate material of the cell was close to a Gaussian distribution, and there was no decomposition product or smear on the surface of the plate material around the cell.

  Printing was actually performed using the obtained polymer printing plate and a printing durability test was performed. The ink used is a water-based ink. There was no generation of static electricity due to friction with the squeegee, and the phenomenon of attracting surrounding dust was not observed. Although printing was performed 1000 times, the shape of the concave portion was hardly changed, and it was found that the plate had good printing durability.

(Example 2)
A polyamic acid solution was prepared in the same manner as in Example 1.

Next, 5 g of an organic salt compound made by Solvent Innovation made from butylmethylpyridinium which is a pyridine-based cation and CH ₃ SO ₃ ^- and 1.4 g Kayfect Red G made by Nippon Kayaku Co., Ltd. which is a pigment. Were collected in a beaker. In this beaker, 300 g of the polyamic acid solution obtained above was dissolved. In this way, a resin composition containing about 10 parts by weight of a mixture of an organic salt compound and a dye with respect to 100 parts by weight of the cured polyimide resin was prepared.

Using the resin composition obtained by the above-mentioned means, a polyimide molded body was prepared in the same procedure as in Example 1. Evaluation similar to Example 1 was performed with respect to the obtained polyimide molded body. As a result, the volume resistivity was 5 × 10 ⁸ Ω · cm, and the tensile elastic modulus was 5 GPa.

  As a result of performing an electron microscope on the cell on the plate material perforated by laser, a cell having an upper diameter of 10 μm and a depth of about 8 μm was formed by irradiation with three shots. There were no degradation products or smears around the cell. Printing was actually performed using the obtained plate and a printing durability test was performed. The ink used is a water-based ink. There was no generation of static electricity due to friction with the squeegee, and the phenomenon of attracting surrounding dust was not observed. Although printing was performed 1000 times, the shape of the cell was hardly changed, and it was found that the cell had good printing durability.

(Example 3)
The resin composition obtained by the same procedure as in Example 1 except that it does not contain a catalyst and a dehydrating agent, was uniformly applied to the surface of an aluminum roll having a diameter of 200 mm and a length of 1000 mm, and was rotated at 100 ° C. The solvent was volatilized by exposing to hot air for 40 minutes. Next, the temperature was raised from 100 ° C. to 380 ° C. over about 30 minutes, and finally the system was cooled to room temperature to form a plate layer mainly composed of polyimide. Evaluation similar to Example 1 was performed with respect to the polyimide molded body obtained in the same manner as Example 1. As a result, the volume resistivity was 9 × 10 ⁷ Ω · cm, and the tensile elastic modulus was 4.3 GPa. The same laser workability and printing durability as in Example 2 were exhibited.

Example 4
A resin composition obtained by kneading isoquinoline and acetic anhydride according to the method of Example 1 was uniformly applied on an aluminum roll using a bar coater so that the film thickness after firing was 30 μm, and the coating was performed for 10 minutes. It left still in the atmosphere of 230 degreeC. Next, the temperature was raised from 100 ° C. to 380 ° C. over about 30 minutes, and finally the system was cooled to room temperature to obtain the target polyimide printing plate.

Evaluation similar to Example 1 was performed with respect to the obtained polyimide printing plate. The volume resistivity was 6 × 10 ⁹ Ω · cm, and the tensile elastic modulus was 5.2 GPa. The same laser workability and printing durability as in Example 1 were exhibited.
(Example 5)
A polyamic acid solution was prepared in the same manner as in Example 1.

Then, ethyl methyl pyridinium a pyridine-based cations, PF ₆ ^- Solvent is Innovation Corp. organic salt compound 5g and the dye of Toa Kasei Co., Ltd., which is formed from a TOA Scarlet 4BS1.4g, a beaker Collected. In this beaker, 300 g of the polyamic acid solution obtained above was dissolved. Thus, the resin composition which contains about 10 weight part of mixture of an organic salt compound and a pigment | dye with respect to 100 weight part of polyimide resins after hardening was prepared. Using the resin composition obtained by the above means, a polyimide printing plate was prepared in the same procedure as in Example 1.

Evaluation similar to Example 1 was performed with respect to the obtained polyimide molded body. As a result, the volume resistivity was 8 × 10 ¹¹ Ω · cm, and the surface became hydrophobic. As a result of the evaluation, the same laser workability and printing durability as in Example 1 were shown.

(Example 6)
In a vessel equipped with a stirring blade, 1500 g of dimethylformamide (DMF) sufficiently dehydrated with molecular sieves was added, 320 g of 9,9-bis (4-aminophenyl) fluorene was added, and the mixture was stirred until completely dissolved. The system was cooled to 0 ° C. and 218 g of pyromellitic dianhydride was gradually added and stirred well. When the viscosity of the system reached about 3 × 10 ² Pa · s, stirring was stopped to obtain a polyamic acid solution.

Next, 6.4 g of an organic salt compound formed from ethylmethylpyridinium which is a pyridine cation and p-CH ₃ C ₆ H ₄ SO ₃ ^— was collected in a beaker. The organic salt compound is manufactured by Solvent Innovation. In this beaker, 300 g of the polyamic acid solution obtained above was dissolved. Thus, the resin composition which contains about 10 weight part of organic salt compounds with respect to 100 weight part of polyimide resins after hardening was prepared. Further, 20 g of isoquinoline as a catalyst and 32 g of acetic anhydride as a dehydrating agent were kneaded with the above solution.

  The resin composition containing the organic salt compound obtained above, a catalyst and a dehydrating agent is applied on a roll having an outer diameter of 200 mm and a length of 1000 mm, and then the applied film is heated from 100 ° C. to 380 ° C. over about 30 minutes. The temperature rose. Finally, the system was cooled to room temperature to obtain a polyimide printing plate. The thickness of the polyimide resin layer is 30 μm.

  In the same manner as the plate material of the obtained polymer printing plate, a polyimide film having the same thickness was separately formed, and its volume resistivity measurement and tensile modulus measurement were performed. The polyimide film was produced by applying the resin composition on an aluminum foil and removing the aluminum foil by etching after heat treatment. In addition, formation of recesses on the plate material surface by the laser irradiation apparatus consisting of 1 to 3 in FIG. 1, its observation, and printing durability evaluation by model experiments were performed.

The volume resistivity measurement was performed according to the following procedure. A test piece of 10 cm × 10 cm × 30 μm was cut out from the obtained polyimide molded body, and the volume resistivity of the test piece was measured using a resistance measuring device R8302 manufactured by Advantest Corporation. As a result, the volume resistivity was 6 × 10 ⁹ Ω · cm. Moreover, the tensile elastic modulus was 4.2 GPa.

  As a result of performing an electron microscope on the cells on the plate material perforated with a laser, a cell having a diameter of 10 μm at the upper surface of the plate material surface of the cell and a depth of 8 μm was formed by irradiation with three shots. The shape of the cross section of the plate material of the cell was close to a Gaussian distribution, and there was no decomposition product or smear on the surface of the plate material around the cell.

  Printing was actually performed using the obtained polymer printing plate and a printing durability test was performed. The ink used is a water-based ink. There was no generation of static electricity due to friction with the squeegee, and the phenomenon of attracting surrounding dust was not observed. Although printing was performed 1000 times, the shape of the concave portion was hardly changed, and it was found that the plate had good printing durability.

(Example 7)
The volume resistivity was 4 × 10 ¹⁰ Ω · cm in the same manner as in Example 6 except that pyromellitic dianhydride was replaced with 438 g of 9,9-bis (3,4-dicarboxyphenyl) fluorenic dianhydride. Met. Also, a polyimide having a tensile modulus of 6.2 GPa was obtained.

  In the same manner as in the experiment of Example 6, it was found that there were no decomposition products or smears on the surface of the plate material around the cell, and the printing durability was good even after 1000 printing tests.

(Example 8)
The volume resistivity was 1.4 × 10 ¹⁰ Ω · cm in the same manner as in Example 6 except that pyromellitic dianhydride was replaced with 315 g of α-oxydiphthalic anhydride. Also, a polyimide having a tensile modulus of 4.0 GPa was obtained.

  In the same manner as in the experiment of Example 6, it was found that there were no decomposition products or smears on the surface of the plate material around the cell, and the printing durability was good even after 1000 printing tests.

(Comparative Example 1)
A polyamic acid solution was prepared in the same manner as in Example 1 except that the organic salt compound and the dye were not added, and a polyimide resin containing no organic salt compound and the dye was synthesized. A printing plate was prepared by applying to an aluminum roll in the same manner as in Example 1. Evaluation similar to Example 1 was performed with respect to the obtained polyimide printing plate. As a result, the volume resistivity was 1 × 10 ¹⁶ Ω · cm or more, and the tensile elastic modulus was 5.1 MPa.

  As a result of the evaluation, the same laser workability as in Example 1 was shown, but the peripheral dust, which seems to be caused by the generation of static electricity during printing, and the transfer of ink to the paper were poor, resulting in a decrease in the quality of the printed matter. . Moreover, the hole had a flat shape.

(Comparative Example 2)
Lion black carbon black EC-600JD 10 g and DMF 600 g were put in a container and stirred well, and further applied to an ultrasonic disperser to uniformly disperse the carbon black in the dispersion.

  598 g of the carbon black dispersion obtained above was collected in a beaker. In this beaker, 300 g of the polyamic acid solution obtained by the same procedure as in Example 1 was dissolved except that no organic salt compound was added. Thus, a resin composition containing about 15 parts by weight of carbon black with respect to 100 parts by weight of the cured polyimide resin was prepared. Further, 20 g of isoquinoline as a catalyst and 32 g of acetic anhydride as a dehydrating agent were kneaded with the resin composition, and a polyimide printing plate was prepared in the same procedure as in Example 1.

Evaluation similar to Example 1 was performed with respect to the obtained polyimide printing plate. As a result, the volume resistivity was 3.4 × 10 ¹⁰ Ω · cm, and the tensile strength was 2.5 MPa. However, in laser processability, as a result of conducting an electron microscope of the concave portion drilled with a laser, a large amount of smear adhered to the periphery of the hole. Further, in the printing durability evaluation, the surface wear was significant after 1000 printings.

(Comparative Example 3)
An inorganic salt compound LiCl (10 g) and DMF (90 g) were placed in a container and stirred well. Next, 19 g of the LiCl solution was collected in a beaker. In this beaker, 300 g of the polyamic acid solution obtained by the same procedure as in Example 1 was dissolved except that no organic salt compound was added. In this way, a resin composition containing about 3 parts by weight of an inorganic salt compound with respect to 100 parts by weight of the cured polyimide resin was prepared, and a polyimide printing plate was prepared in the same procedure as in Example 1.

Evaluation similar to Example 1 was performed with respect to the obtained polyimide molded body. As a result, the volume resistivity was 4 × 10 ⁹ Ω · cm. However, this printing plate is inferior in resistance to water-based ink, and remarkable wear due to dissolution of the plate surface in the ink during repeated printing occurred.

  The resin composition according to the present invention has been described above. However, the present invention is not limited to the above-described embodiment, and can be implemented in various modifications within the described range.

  The resin composition according to the present invention has been described above. However, the present invention is not limited to the above-described embodiment, and can be implemented in various modifications within the described range.

(Comparative Example 4)
A polyamic acid solution was prepared in the same manner as in Example 6 except that no organic salt compound was added, and a polyimide resin containing no organic salt compound was synthesized. The same method as in Example 6 was applied to an aluminum roll to prepare a printing plate. Evaluation similar to Example 6 was performed with respect to the obtained polyimide printing plate. As a result, the volume resistivity was 1 × 10 ¹⁶ Ω · cm or more, and the tensile elastic modulus was 5.1 MPa.

  As a result of the evaluation, the laser processability similar to that of Example 6 was shown, but the quality of the printed matter was deteriorated due to the adsorption of peripheral dust, which was thought to be caused by the generation of static electricity during printing, and the poor transfer of ink to paper. .

Conceptual diagram of laser printing plate manufacturing equipment

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ultraviolet laser light source 2 Beam shaping irradiation part 3 Irradiation part which supplies plate material information to a light source and a beam shaping irradiation part 4 Polymer plate material 5 Metal roll

Claims (21)

  A resin composition for a plate material comprising an organic salt compound.   The resin composition for a plate material according to claim 1, further comprising a pigment.   3. The resin composition for a plate material according to claim 1, wherein the organic salt compound and / or the pigment is contained in an amount of 0.01 to 30 parts by weight with respect to 100 parts by weight of the resin composition for a plate material. A resin composition for a plate material, characterized by comprising:   The resin composition for a plate material according to any one of claims 1 to 3, comprising a polyimide resin or an organic compound that is polymerized to become a polyimide resin as a main component. . The polyimide resin is a polyimide resin having a glass transition temperature of 250 ° C. or higher,
And / or a polyimide resin soluble in an organic solvent,
The resin composition for a plate material according to claim 4. The polyimide resin is
A polyimide resin having a glass transition temperature of 250 ° C. or higher when measured with a differential thermal analyzer in nitrogen at a heating rate of 10 ° C./min,
And / or is characterized in that it is soluble in at least 5% by weight or more when left standing in a ketone, ether, alcohol, amine, sulfonamide solvent having a boiling point of 150 ° C. or lower at room temperature for 24 hours or more.
The resin composition for a plate material according to claim 4 or 5. The polyimide resin or the organic compound that is polymerized to become a polyimide resin is at least one selected from the formulas (1) to (4)

The resin composition for a plate material according to claim 4, which has a fluorene skeleton in the main chain skeleton. The resin composition for a plate material according to any one of claims 1 to 7, wherein the anion comprises the organic salt compound, but the anion has an SO ₃ ^- group, an anion having a COO ^- group, A resin composition for a plate material, which is at least one selected from fluorine-containing anions and fluoroalkylsulfuric acid.   The resin composition for a plate material according to any one of claims 1 to 8, wherein the cation constituting the organic salt compound is at least selected from a pyridine series, an alicyclic amine series, and an ammonium salt series. A resin composition for a plate material, which is one or more.   A polymer printing plate comprising a plate material formed from the resin composition for a plate material according to claim 1. 11. The polymer printing plate according to claim 10, wherein the volume resistance value of the plate material is 10 ³ Ω · cm to 10 ¹⁵ Ω · cm.   The polymer printing plate according to claim 10 or 11, wherein the plate material has a tensile modulus of elasticity of 3 GPa or more.   The polymer printing plate according to any one of claims 10 to 12, further comprising a laser printing plate by forming a concave portion on the surface of the plate material by irradiating a laser beam having a wavelength shorter than 370 nm. A polymer printing plate characterized by that.   The polymer printing plate according to any one of claims 10 to 13, wherein the plate material is formed on a metal substrate.   15. The polymer printing plate according to claim 14, wherein the plate-like plate material mainly composed of a polyimide resin is attached to the metal substrate via an adhesive layer and formed as a plate material layer. A polymer printing plate characterized by comprising:   15. The polymer printing plate according to claim 14, wherein the plate material mainly composed of a polyimide resin soluble in an organic solvent is applied on the metal substrate to be formed as a plate material layer. A polymer printing plate.   15. The polymer printing plate according to claim 14, wherein the plate material mainly composed of a thermoplastic polyimide resin is thermally fused onto the metal substrate to form a plate material layer. Polymer printing plate.   The polymer printing plate according to any one of claims 15 to 17, wherein the polyimide resin soluble in the organic solvent is a polyimide resin having a glass transition temperature of 250 ° C or higher. The polyimide resin and thermoplastic polyimide resin are
A polyimide resin having a glass transition temperature of 250 ° C. or higher,
And / or a polyimide resin soluble in an organic solvent,
The polymer printing plate according to any one of claims 15 to 17. The polyimide resin, a polyimide resin soluble in an organic solvent, a thermoplastic polyimide resin,
A polyimide resin having a glass transition temperature of 250 ° C. or higher when measured with a differential thermal analyzer in nitrogen at a heating rate of 10 ° C./min,
And / or is characterized by being soluble in at least 5% by weight or more when left standing at room temperature for 24 hours or more in a ketone, ether, alcohol, amine or sulfonamide solvent having a boiling point of 150 ° C. or less.
The polymer printing plate according to any one of claims 15 to 19. The polyimide resin, a polyimide resin soluble in an organic solvent, or a thermoplastic polyimide resin is at least one selected from the formulas (5) to (8)

The polymer printing plate according to any one of claims 15 to 19, which has a fluorene skeleton in the main chain skeleton.

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