JP2007133126A - Drawn photosensitive resin letterpress printing original plate ,and method of platemaking photosensitive resin letterpress printing original plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photosensitive resin printing original plate excellent in handleability on which a projected relief image can be formed without requiring an original picture film, and to provide a method of making the photosensitive resin printing original plate. <P>SOLUTION: The drawn photosensitive resin letterpress printing original plate has at least a photosensitive resin layer (A), a drawn thermosensitive mask layer (B') and a protective layer (C), layered in this order on a support. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a drawn photosensitive resin letterpress original plate suitable for digital information transfer with good handleability and a plate making method of the photosensitive resin letterpress original plate.

  The use of a photosensitive resin composition as a printing plate material is generally performed, and has become mainstream in each field of resin relief printing, planographic printing, intaglio printing, and flexographic printing. In such a printing plate material, an original film is adhered to the photosensitive resin layer, and exposed to actinic rays through the original film, thereby forming a part that dissolves in the solvent and a part that does not dissolve in the photosensitive resin layer. A relief image is formed and used as a printing plate material.

  Such a printing plate material requires negative and positive original film, and therefore requires manufacturing time and cost. Furthermore, the development of the original image film requires chemical processing and also requires processing of the development waste liquid, which is disadvantageous in terms of environmental hygiene.

  With the advancement of computers in recent years, a so-called CTP (computer to plate) method has been proposed in which information processed on a computer is directly output onto a printing plate material, and a relief printing plate can be obtained without the need to create an original film. Has been. In this CTP method, an image mask is formed on the photosensitive resin “in situ” from digital data, and then the entire surface is exposed from the image mask side with actinic rays, in many cases ultraviolet rays, so that the image mask is not covered. Only the part selectively cures the photosensitive resin layer. The advantages of this method are that the above-described original film production process is not required, the processing of the development waste liquid of the original film is unnecessary and preferable for environmental hygiene, and foreign matters are not mixed when the original film is brought into close contact. And a relief having a sharp structure can be obtained.

Photosensitive resin letterpress recording material formed from a photosensitive resin layer, an oxygen-permeable dividing layer, an infrared-sensitive layer that is opaque to ultraviolet light, and a protective layer is proposed as a photosensitive resin letterpress that uses the CTP method. (For example, refer to Patent Document 1). Here, an infrared ray is irradiated to form an image mask on the infrared-sensitive layer. This infrared-sensitive layer has a function of blocking ultraviolet light such as carbon black in a water-soluble or water-dispersible binder. , A material that absorbs infrared rays. The infrared-sensitive layer does not have a cross-linked structure and is vulnerable to trauma, so it was necessary to pay attention to handling after peeling the cover film. When penetrating scratches are generated in the infrared-sensitive layer before the ultraviolet exposure, there is a problem that the ultraviolet rays are transmitted from that portion and the photosensitive resin is photocured, which is a disadvantage of the printing original plate.
Japanese Patent No. 3429634 (pages 3-7)

  In view of the above problems, an object of the present invention is to provide a photosensitive resin printing plate precursor having excellent handleability and a plate making method capable of forming a relief image without requiring an original film. .

  In order to solve the above-mentioned problems, the present invention is characterized in that “the support has at least a photosensitive resin layer (A), a drawn thermal mask layer (B ′), and a protective layer (C) in this order. "Photographed photosensitive resin letterpress original plate".

  Furthermore, “(1) a step of drawing on the heat-sensitive mask layer (B) of the photosensitive resin relief printing plate precursor having at least the photosensitive resin layer (A) and the heat-sensitive mask layer (B) on the support, (2) drawing A method of making a photosensitive resin relief plate precursor comprising at least a step of exposing from the heat-sensitive mask layer (B ′) side, (3) a step of developing, wherein (1) after the drawing step (2) before the exposure step, And / or (2) after the exposure step, and (3) before the development step, a protective layer (C) is provided on the drawn heat-sensitive mask layer (B ′), and the plate making method of the photosensitive resin relief plate precursor. It is.

  According to the present invention, by providing a protective layer (C) after drawing on the heat-sensitive mask layer (B), it is possible to prevent scratches on the heat-sensitive mask layer due to handling between drawing and development. I can do it. If a photosensitive resin is used, it can be applied not only to a resin relief printing plate having a convex relief, but also to a flexographic printing plate, an intaglio printing plate, a lithographic printing plate, a stencil printing plate, but its application range is not limited to these. Absent.

  Embodiments of the present invention will be described below.

  In the present invention, the photosensitive resin relief plate precursor has a structure in which at least a photosensitive resin layer (A) and a thermal mask layer (B) are laminated in this order on a support. The drawn photosensitive resin letterpress original plate has a structure in which at least a photosensitive resin layer (A), a drawn thermal mask layer (B ′), and a protective layer (C) are laminated in this order on a support. Have.

  The photosensitive resin layer (A) in the present invention comprises a photosensitive resin composition containing a water-soluble or water-swellable polymer, a photocurable monomer, and a photopolymerization initiator, and preferably has an ultraviolet wavelength of 300 to 400 nm. It is photocured by irradiating light.

  The water-soluble or water-swellable polymer in the present invention has a function as a carrier resin for maintaining the form of the photosensitive resin composition in a solid state, and the water developability of the photosensitive resin layer (A). Used to grant Examples of such resins include polyvinyl alcohol, polyvinyl acetate, partially saponified polyvinyl acetate (partially saponified polyvinyl alcohol), cellulose resin, acrylic resin, polyamide resin introduced with a hydrophilic group such as polyethylene oxide, ethylene / vinyl acetate. Examples include copolymers and modified products of these resins. Of these, polyvinyl alcohol, partially saponified polyvinyl alcohol, polyamide resin having a hydrophilic group introduced therein, and modified products of these resins are preferably used.

  The monomer curable by ultraviolet light in the present invention is a substance that can be cross-linked by radical polymerization. Although it will not specifically limit if it is a substance which can be bridge | crosslinked by radical polymerization, For example, the following can be mentioned. 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 3-chloro-2-hydroxypropyl (meth) acrylate, β-hydroxy-β ′-(meth) (Meth) acrylate having a hydroxyl group such as acryloyloxyethyl phthalate, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, isoamyl (meth) acrylate, 2-ethylhexyl (meth) Alkyl (meth) acrylates such as acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, cycloalkyl (meth) acrylates such as cyclohexyl (meth) acrylate, chloroethyl (meth) acrylate Relate, Alkyl halide (meth) acrylate such as chloropropyl (meth) acrylate, Alkoxyalkyl (meth) acrylate such as methoxyethyl (meth) acrylate, Ethoxyethyl (meth) acrylate, Butoxyethyl (meth) acrylate, Phenoxyethyl acrylate , Alkoxyalkylene glycol (meth) acrylates such as phenoxyalkyl (meth) acrylates such as nonylphenoxyethyl (meth) acrylate, ethoxydiethylene glycol (meth) acrylate, methoxytriethylene glycol (meth) acrylate, methoxydipropylene glycol (meth) acrylate , (Meth) acrylamide, diacetone (meth) acrylamide, N, N′-methylenebis (meth) acrylami (Meth) acrylamides such as 2,2-dimethylaminoethyl (meth) acrylate, 2,2-diethylaminoethyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylamide, N, N-dimethylamino Compounds having only one ethylenically unsaturated bond such as propyl (meth) acrylamide, polyethylene glycol di (meth) acrylate such as diethylene glycol di (meth) acrylate, polypropylene such as dipropylene glycol di (meth) acrylate Glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, glycerol tri (meth) acrylate Polyhydric (meth) acrylates, glycidyl (meth) acrylates, etc. obtained by addition reaction of ethylenic unsaturated bonds such as unsaturated carboxylic acids and unsaturated alcohols and compounds with active hydrogen to ethylene glycol diglycidyl ether Multivalent (meth) acrylamides such as polyvalent (meth) acrylates and methylenebis (meth) acrylamides obtained by addition reaction of saturated epoxy compounds and compounds with active hydrogen such as carboxylic acids and amines, and polyvalents such as divinylbenzene Examples thereof include compounds having two or more ethylenically unsaturated bonds, such as vinyl compounds.

  The photopolymerization initiator preferably used in the present invention is not particularly limited as long as it can polymerize a polymerizable carbon-carbon unsaturated group by light. Among these, those having a function of generating radicals by self-cleavage or hydrogen abstraction are preferably used. Examples include benzoin alkyl ethers, benzophenones, anthraquinones, benzyls, acetophenones, diacetyls, and the like.

  The photosensitive resin composition has other components such as ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, glycerin, trimethylolpropane, and trimethylolethane for the purpose of increasing compatibility and flexibility. Alcohols can be added, and conventionally known polymerization inhibitors can also be added to increase thermal stability. Preferable polymerization inhibitors include phenols, hydroquinones, catechols and the like. Furthermore, dyes, pigments, surfactants, ultraviolet absorbers, fragrances, antioxidants, and the like can be added.

  The method for obtaining the photosensitive resin layer (A) from the photosensitive resin composition is not particularly limited. For example, after dissolving a water-soluble or water-swellable polymer in a solvent, a monomer that can be cured by ultraviolet light, light A polymerization initiator and other additives as necessary are added and stirred sufficiently to prepare a photosensitive resin composition solution. After casting this solution on a support preferably coated with an adhesive, the solvent is volatilized. Can be obtained. Alternatively, it can be obtained by forming a sheet of the photosensitive resin composition in advance and laminating it on a support coated with an adhesive.

  As the photosensitive resin layer in the present invention, a known photosensitive resin can be arbitrarily used. The thickness of the photosensitive resin layer is preferably in the range of 0.1 to 10 mm, more preferably in the range of 0.1 to 2 mm.

  The material used for the support in the present invention is not particularly limited, but a dimensionally stable material is preferably used. For example, a metal sheet such as steel, stainless steel, and aluminum, a plastic sheet such as polyester, and a synthetic rubber such as styrene-butadiene rubber. Sheet.

  Further, the support in the present invention is a photosensitive resin relief plate, and a known support can be arbitrarily used, and its size and thickness are not particularly limited.

  The heat-sensitive mask layer (B) in the present invention practically blocks ultraviolet light, efficiently absorbs infrared laser at the time of drawing, and partly or entirely is evaporated or ablated instantaneously by the heat. That is, the optical density of the laser irradiated portion is lowered. As a result, a difference occurs in the optical density between the laser irradiated portion and the non-irradiated portion, and the same function as the conventional negative and positive original film can be achieved.

  Therefore, the heat-sensitive mask layer (B) of the present invention shields ultraviolet rays, preferably a thermally decomposable compound having a function of evaporating and ablating by heat, in addition to an infrared absorbing material having a function of absorbing infrared rays and converting it into heat. Contains an ultraviolet absorbing material having the function of

Here, having the function of blocking ultraviolet light means that the optical density of the thermal mask layer (C) is 2.5 or more, and more preferably 3.0 or more. The optical density is generally represented by D and is defined by the following equation.
D = log ₁₀ (100 / T) = log ₁₀ (I ₀ / I)
(Here, T is transmittance (unit:%), I ₀ is incident light intensity at the time of measuring transmittance, and I is transmitted light intensity).

  For optical density measurement, there are known methods of calculating from the measured value of transmitted light intensity with a constant incident light intensity and calculating from the measured value of incident light intensity required to reach a certain transmitted light intensity. However, the optical density in the present invention is a value calculated from the former transmitted light intensity.

  The optical density can be measured by using a Macbeth transmission densitometer “TR-927” (manufactured by Kollmorgen Instruments Corp.) using an orthochromatic filter.

  The infrared absorbing material used in the present invention is not particularly limited as long as it can absorb infrared light and convert it into heat. For example, black pigments such as carbon black, aniline black, cyanine black, phthalocyanine, naphthalocyanine green pigment, rhodamine dye, naphthoquinone dye, polymethine dye, diimonium salt, azoimonium dye, chalcogen dye, carbon graphite, diamine Metal complexes, dithiol metal complexes, phenol thiol metal complexes, mercaptophenol metal complexes, arylaluminum metal salts, crystal water-containing inorganic compounds, copper sulfate, chromium sulfide, silicate compounds, titanium oxide, vanadium oxide, oxidation Examples thereof include metal oxides such as manganese, iron oxide, cobalt oxide, and tungsten oxide, hydroxides and sulfates of these metals, and metal powders of bismuth, tin, tellurium, iron, and aluminum.

  Among these, carbon black is preferably used from the viewpoints of the photothermal conversion rate, economic efficiency, handleability, and the ultraviolet absorption function described later.

  The content of the infrared absorbing material is preferably 2 to 75% by weight, more preferably 5 to 70% by weight, based on the total composition of the heat-sensitive mask layer (B). If it is 2% by weight or more, photothermal conversion is carried out efficiently, and if it is 75% by weight or less, the other components are insufficient and the coating property of the heat-sensitive mask layer (B) is not lowered.

  Examples of the thermally decomposable compounds include nitro compounds such as ammonium nitrate, potassium nitrate, sodium nitrate and nitrocellulose, organic peroxides, polyvinylpyrrolidone, azo compounds, diazo compounds or hydrazine derivatives, and metals listed in the section of infrared absorbing materials Alternatively, metal oxides may be mentioned, but from the standpoint of solution coating properties, polymer compounds such as polyvinyl pyrrolidone, nitrocellulose, and acrylic resins are preferable.

  In particular, acrylic resin is relatively easy to thermally decompose, and by selecting a grade that does not dissolve in water or alcohol, mass transfer to the lower photosensitive resin layer (A) can be suppressed. A type acrylic resin is more preferably used.

  The content of the thermally decomposable compound is preferably 80% by weight or less, and more preferably 15 to 60% by weight with respect to the total composition of the thermal mask layer (C). If content is 80 weight% or less, the problem that decomposition | disassembly of a thermally decomposable compound cannot succeed with the fall of the amount of photothermal conversion substances mentioned later does not generate | occur | produce.

  Although it does not specifically limit as an ultraviolet-absorbing substance, Preferably, it is a compound which has absorption in the 300 nm-400 nm area | region. For example, benzotriazole-based compounds, triazine-based compounds, benzophenone-based compounds, carbon black, and metals or metal oxides listed in infrared absorbing materials can be used. Among these, carbon black is particularly preferably used because it has absorption characteristics not only in the ultraviolet light region but also in the infrared light region and functions as a photothermal conversion substance.

  The content of the ultraviolet absorbing material is preferably 0.1% by weight to 75% by weight and more preferably 1% by weight to 50% by weight with respect to the total composition of the heat sensitive mask layer (B). If the content is 0.1% by weight or more, the required optical density is obtained, and if it is 75% by weight or less, other components are insufficient and the coating property of the thermal mask layer (B) is lowered. Does not occur.

  The heat-sensitive mask layer (B) in the present invention is preferably water-insoluble. The thermal mask layer (B) is laminated on the photosensitive resin layer (A), but the photosensitive resin layer (A) has a hydrophilic composition as described above, and the thermal mask layer (B) is hydrophilic. In the case of a sex composition, mass transfer occurs between layers, and functions unique to each layer deteriorate. For example, if the monomer in the photosensitive resin layer (A) moves to the thermal mask layer (B), the laser ablation property of the thermal mask layer (B) is impaired, and the photosensitive resin layer (A) When an ultraviolet absorbing substance is mixed in the resin, curing by ultraviolet light is inhibited.

  Therefore, the heat-sensitive mask layer (B) used in the present invention is preferably water-insoluble. The method for imparting water insolubility to the heat-sensitive mask layer (B) is not particularly limited. For example, a method in which the entire composition of the heat-sensitive mask layer (B) is composed of water-insoluble components, or a layer using a curable resin as a binder. Can be achieved by a method of cross-linking. The latter method is preferable because an effect of making the inter-layer mass transfer less likely to occur by polymerizing the composition component and an effect of imparting scratch resistance to the surface of the thermal mask layer (B) are obtained.

  When a curable resin is used as a binder, the method for curing the resin is not particularly limited. However, since the thermal mask layer (B) has a function of absorbing ultraviolet light, photocuring is difficult or inefficient. Is preferred. Examples of the thermosetting resin used as the binder include at least one compound selected from the group consisting of polyfunctional isocyanates and polyfunctional epoxy compounds, urea resins, amine compounds, amide compounds, hydroxyl group-containing compounds, and carboxylic acids. The combination with the at least 1 sort (s) of compound chosen from the group which consists of a compound and a thiol type compound is mentioned.

  Of these, a preferred crosslinking method is a combination of a polyfunctional epoxy compound and at least one compound selected from the group consisting of urea resins, amine compounds, amide compounds, hydroxyl group-containing compounds, carboxylic acid compounds, and thiol compounds. Is mentioned.

  Here, examples of the polyfunctional epoxy compound include bisphenol A type epoxy resin, bisphenol F type epoxy resin, and glycidyl ether type epoxy resin.

  Examples of urea resins include butylated urea resins, butylated melamine resins, butylated benzoguanamine resins, butylated urea melamine cocondensation resins, aminoalkyd resins, iso-butylated melamine resins, methylated meminine resins, hexamethoxymethylol. Examples include melamine, methylated benzoguanamine resin, butylated benzoguanamine resin and the like.

  Examples of the amine compound include diethylenetriamine, triethylenetriamine, tetraethylenepentamine, diethylaminopropylamine, N-aminoethylpiperazine, metaxylenediamine, metaphenylenediamine, diaminodiphenylmethane, diaminodiphenylsulfone, and isophoronediamine. .

  In addition, examples of amide compounds include polyamide curing agents and dicyandiamide used as epoxy resin curing agents. Examples of hydroxyl group-containing compounds include phenol resins and polyhydric alcohols. Examples of thiol compounds include polyvalent thiols. and so on.

  As the carboxylic acid, phthalic acid, hexahydrophthalic acid, tetrahydrophthalic acid, dodecinyl succinic acid, pyromellitic acid, chlorenic acid, maleic acid, fumaric acid and anhydrides thereof are preferably used.

  Apart from the method of using a curable resin with a plurality of components, a single component or a curable resin may be used. Resins that are curable even when used alone include melamine resins, urethane resins, crosslinkable polyester resins, crosslinkable polyamide resins, and the like in addition to epoxy resins. These resins can also be used in combination.

  The content of these thermosetting resins is preferably 10% by weight to 75% by weight or less, more preferably 30% by weight to 60% by weight with respect to the total composition of the heat sensitive mask layer (B). If it is 10% by weight or more, a crosslinked structure sufficient to impart water insolubility is obtained, and if it is 75% by weight or less, laser ablation of the thermal mask layer (B) is efficiently performed.

  In addition, when a pigment such as carbon black is used as the infrared absorbing material, a plasticizer, a surfactant or a dispersion aid may be added to facilitate the dispersion.

  The method for forming the heat-sensitive mask layer (B) is not particularly limited, but when a metal oxide is used, for example, it is obtained by vapor deposition or sputtering, and when an organic substance such as carbon black is used, a heat-sensitive mask layer composition. Can be obtained as such or by dissolving in an appropriate solvent, coating, and heat curing.

  The thickness of the heat-sensitive mask layer (B) obtained by coating is preferably 0.5 μm to 10 μm, more preferably 1 μm to 3 μm. When the thickness is 0.5 μm or more, surface scratches are hardly generated and light leakage hardly occurs, a constant high optical density can be obtained, and a high coating technique is not required. Moreover, if it is 10 micrometers or less, since high energy is not required for ablating the thermal mask layer (B), it is advantageous in terms of cost.

  The heat-sensitive mask layer (B) obtained by vapor deposition or sputtering of metal or metal oxide is preferably a thin film if a high optical density can be obtained. The thickness of the thin film greatly affects the sensitivity. That is, if the film thickness is too thick, extra energy is required to evaporate and melt the thin film, and the ablation sensitivity of the thermal mask layer (B) is lowered. Therefore, the thickness of the thin film is preferably 100 nm or less, more preferably 2 to 100 nm, and particularly preferably 4 to 20 nm. Even if the film thickness is thinner than 2 nm, the sensitivity may decrease.

When using the vapor deposition method, vacuum vapor deposition is preferably used. Specifically, a method of forming a thin film on the surface of the substrate by heating and evaporating metal and carbon in a vacuum container of 10 ⁻⁴ to 10 ⁻⁷ mmHg, etc. Is used.

When the sputtering method is used, for example, a direct current or an alternating voltage is applied to a pair of electrodes in a vacuum container of 10 ⁻¹ to 10 ⁻³ mmHg to cause glow discharge, and in the case of a cathode or an alternating current, a ground electrode A thin film can be formed on a substrate using the sputtering phenomenon.

  As a thin film layer that provides the high optical density required in the present invention, a carbon thin film layer can be mentioned first. The carbon thin film here is not a so-called diamond thin film or graphite thin film but an amorphous carbon thin film. The amorphous carbon thin film can be selectively obtained by performing ordinary vacuum deposition such as ion beam deposition or ionization deposition, or sputtering such as ion beam sputtering.

  As a carbon thin film formation method, it is preferable to carry out by any one of vacuum vapor deposition and sputtering.

As a vacuum deposition condition for forming a carbon thin film, for example, a method of forming a thin film on the surface of a substrate by heating and evaporating carbon in a 10 ⁻⁴ to 10 ⁻⁷ mmHg vacuum vessel is preferably used. Since carbon has a high melting point of 3923K, it is preferable to increase the heating temperature and deposition time of carbon for vapor deposition.

As sputtering conditions for forming a carbon thin film, a direct current or an alternating voltage is applied to a pair of electrodes in a vacuum vessel of 10 ⁻¹ to 10 ⁻³ mmHg to cause glow discharge, and the sputtering phenomenon of the cathode is used. A method of forming a thin film on a substrate is preferably used. In this method, a thin film can be formed relatively easily even with carbon having a high melting point.

  Examples of the thin film layer for providing the thermal mask layer (B) include a metal thin film layer in addition to the carbon thin film layer. Specific examples of the metal include the following, but are not limited thereto. Tellurium, tin, antimony, gallium, magnesium, polonium, selenium, thallium, zinc, aluminum, silicon, germanium, tin, copper, iron, molybdenum, nichrome, indium, iridium, manganese, lead, phosphorus, bismuth, nickel, titanium, Cobalt, rhodium, osnium, mercury, barium, palladium, bismuth and compounds such as those described in Japanese Examined Patent Publication No. 41-14510, such as silicon carbide, boron nitride, boron phosphide, aluminum phosphide, antimony and aluminum Alloys, alloys of gallium and phosphorus, alloys of gallium and antimony, and the like. Preferably, tellurium, tin, antimony, gallium, magnesium, polonium, selenium, thallium, zinc, bismuth, and aluminum are used.

  As the metal preferably used for the layer (B), since the reflection of the laser on the surface increases when the metallic luster increases, the metal having a small metallic luster is preferable from the viewpoint of sensitivity.

  As the metal used for the heat-sensitive mask layer (B), any metal can be preferably used as long as a part or all of the metal evaporates or melts instantaneously and the melting point is 2000K or less. If the melting point is larger than 2000K, it takes time to evaporate or melt even when irradiated with a laser, and as a result, the ablation sensitivity of the thermal mask layer (B) is lowered. The melting point is more preferably 1000 K or less. Specifically, tellurium, tin, antimony, gallium, magnesium, polonium, selenium, thallium, zinc, bismuth and aluminum are preferably used, more preferably tellurium (melting point: 449.8 ° C.), tin (melting point: 232 ° C.), Examples thereof include zinc (melting point: 419.5 ° C.) and aluminum (melting point: 660.4 ° C.). These metals are particularly preferable because they easily evaporate or melt by heat when the thin film is irradiated with laser.

  As the metal preferably used in the heat-sensitive mask layer (B), it can be said that it is particularly preferable to use two or more kinds of the above-mentioned metals because the melting point is more easily lowered and the sensitivity is improved. Specifically, tellurium and tin, tellurium and antimony, tellurium and gallium, tellurium and bismuth, tellurium and zinc alloys are preferred, and tellurium and zinc, and tellurium and tin alloys are more preferred. Of the three types of alloys, alloys of tellurium and tin and zinc, tellurium and gallium and zinc, tin and antimony and zinc, tin and bismuth and zinc, and more preferably tellurium and tin and zinc, and tin and bismuth and zinc are preferred. Is an alloy.

  The method for forming such a metal thin film is not particularly limited, but it is preferably performed by any one of vacuum deposition and sputtering.

  A thin film layer containing carbon and metal can also be used as the thin film layer for providing the thermal mask layer (B). By simultaneously depositing or sputtering carbon and metal, there is an advantage that the optical density of the thin film is improved and it becomes easier to absorb the infrared laser. In this case, many metals can be used. The metal or alloy used at this time is not particularly limited as long as it can be deposited or sputtered, but a metal having a melting point of 2000K or less is preferable, and 1000K or less is more preferable. When the melting point is higher than 2000K, it is difficult to form an image even if carbon is vapor-deposited or sputtered at the same time.

  When metal and carbon are vapor-deposited or sputtered simultaneously, the weight percentage of carbon in the formed thin film is preferably 10% by weight or more, and more preferably 30% by weight or more. If carbon is 10 weight% or more, the absorption factor of an infrared laser will increase and the effect of a sensitivity improvement will be acquired.

  When the hydrophilic photosensitive resin layer (A) and the water-insoluble thermal mask layer (B) are laminated so as to be in contact with each other, the adhesiveness between the layers is insufficient due to the difference in polarity. B) may be easily peeled off or wrinkles may occur. In such a case, these problems can be avoided by providing the adhesive force adjusting layer (D) between the photosensitive resin layer (A) and the thermal mask layer (B).

  The adhesion adjusting layer (D) is characterized by containing partially saponified polyvinyl acetate having a saponification degree of 60 mol% or more. More preferably, the degree of saponification is 70 mol% or more and 99 mol% or less. If the degree of saponification is less than 60 mol%, the adhesive strength may be insufficient and the water developability may be lowered. The degree of polymerization is not particularly limited as long as it is a partially saponified polyvinyl acetate having a saponification degree of 60 mol% or more, and those modified with an acid or the like can also be used.

  In addition to the partially saponified polyvinyl acetate having a saponification degree of 60 mol% or more, the adhesive strength adjusting layer (D) adjusts resins and monomers for adjusting the appropriate adhesive strength, coating properties and stability. It is also optional to add additives such as a surfactant and a plasticizer. Further, after laminating the adhesive force adjusting layer, it may be diffused and transferred to the photosensitive resin layer (A) for assimilation.

  The content of partially saponified polyvinyl acetate having a saponification degree of 60 mol% or more is preferably 50 wt% or more, more preferably 60 wt%, based on the total composition of the adhesive strength adjusting layer. If it is 50% by weight or more, a uniform film can be formed and sufficient adhesive strength with the heat-sensitive mask layer can be obtained.

  The method of forming the adhesive force adjusting layer (D) is not particularly limited, but for the convenience of thin film formation, the solvent is removed after coating on the thermal mask layer in a state where the adhesive force adjusting layer components are dissolved in the solvent. Is preferably performed. Examples of the method for removing the solvent include hot air drying, far-infrared drying, and natural drying.

  The film thickness of the adhesive force adjusting layer (D) is preferably 15 μm or less, and more preferably 0.1 μm or more and 5 μm or less. If it is 15 μm or less, bending and scattering of light by the layer when exposed to ultraviolet light can be suppressed, and a sharp relief image can be obtained. Moreover, if it is 0.1 micrometer or more, formation of an adhesive force adjustment layer will become easy.

  The protective layer (C) in the present invention has the purpose of protecting the drawn thermal mask layer (B ′), and after drawing on the thermal mask layer (B), it is laminated on the drawn thermal mask layer (B ′). Provided. Moreover, when the photosensitive resin relief printing plate precursor of this invention has the peeling assistance layer (E) mentioned later on a thermal mask layer (B), a thermal mask layer (B), a peeling assistance layer (E), a protective layer (C ) May be stacked in the order.

  The protective layer (C) in the present invention is not particularly limited in material and type, and is, for example, paper, nonwoven fabric, cloth, synthetic resin film or sheet, or laminated sheet or film provided with a resin layer on one or both sides of paper. Is given.

  Paper includes mechanical pulp obtained by mechanical treatment such as ground pulp, chemical pulp obtained by chemical treatment such as kraft pulp, pulp obtained by combining mechanical treatment and chemical treatment such as chemi-ground pulp, etc. , And natural fibers such as cotton and hemp. Here, the presence or absence of bleaching of the pulp and the bleaching method are not particularly limited. Furthermore, chemical fiber paper made of chemical fibers such as polyolefins such as polyethylene and polystyrene, rayon, nylon, vinylon and polyester can also be used. Paper using natural pulp such as wood and synthetic pulp such as chemical fiber can also be used, and is not limited to paper made of these exemplified raw materials.

  These papers can be used without any problem even if they contain mineral fillers such as clay, talc and calcium carbonate, sizing agents such as rosin and synthetic resins, and other additives.

  In addition, as the nonwoven fabric, natural fibers such as cotton, hemp, silk, and wool, chemical fibers such as rayon and acetate, or synthetic fibers such as nylon, polyester, and acrylic are used. Examples of the material include a sheet combined with an agent. It does not specifically limit as a manufacturing method of a nonwoven fabric, The nonwoven fabric by any manufacturing methods, such as a dry process, a wet method, and a spun bond, can also be used.

  As the synthetic resin film or sheet, any film or sheet made of a known synthetic resin can be used, and a film or sheet made of a thermoplastic resin such as polyethylene or polyester, or a thermosetting resin such as polyamide can be used. A sheet such as polyurethane foam can also be used.

  In addition to a film or sheet made of a single synthetic resin, a film or sheet obtained by laminating a plurality of these layers, or a film or sheet formed by alloying a plurality of types of synthetic resins can also be used. Furthermore, laminated paper in which the above-described various papers and the above-described various synthetic resin layers are laminated, sand paper laminated in a sandwich structure, and the like can also be used.

Although the weight of the protective layer (C) in this invention is not specifically limited, 25-200 g / m < ² > is preferable and 50-150 g / m < ² > is more preferable. If it is 25 g / m ² or more, it is easy to handle, and a function of protecting the drawn heat-sensitive mask layer (B ′) from damage is expressed. If it is 200 g / m ² or less, it is inexpensive and economically advantageous. is there.

  In the photosensitive resin relief printing plate precursor of the present invention, a cover film (F) may be provided on the opposite side of the photosensitive resin layer (A) to the thermal mask layer (B). The cover film (F) can be used for the purpose of protecting the heat-sensitive mask layer (B) from injury. For the cover film (F), a polymer film that can be peeled off from the heat-sensitive mask layer (B) is preferably used. Specific examples include films of polyester, polycarbonate, polyamide, fluoropolymer, polystyrene, polyethylene, polypropylene, and the like. Alternatively, release paper coated with silicone or the like can also be used as the cover film (F).

  Furthermore, in the photosensitive resin relief printing plate precursor of the present invention, a peeling auxiliary layer (E) may be provided between the heat-sensitive mask layer (B) and the cover film (F). It is preferable that the peeling auxiliary layer (E) has a function of easily peeling only the cover film (F) or both the cover film (F) and the peeling auxiliary layer (E) from the photosensitive resin printing plate precursor.

  When the cover film (F) and the thermal mask layer (B) are directly laminated and the adhesive strength between the two layers is strong, the cover film (F) may not be peeled off or may be peeled off together with the thermal mask layer (B). is there. Therefore, the peeling auxiliary layer (E) has a strong adhesive force with the thermal mask layer (B) and is weak enough to peel the adhesive force with the cover film (F), or with the thermal mask layer (C). It is preferably composed of a substance that is weak enough to peel off and has a strong adhesive force with the cover film (F). After peeling the cover film (F), the peeling auxiliary layer (E) may remain on the thermal mask layer (B) side and become the outermost layer. Since it is exposed to ultraviolet light, it is preferably substantially transparent.

  Materials used for the peeling auxiliary layer (E) include polyvinyl alcohol, polyvinyl acetate, partially saponified polyvinyl alcohol, hydroxyalkyl cellulose, alkyl cellulose, polyamide resin, and the like, which can be dissolved or dispersed in water and are adhesive. It is preferable to use a resin having a small amount as a main component. Among these, partially saponified polyvinyl alcohol having a saponification degree of 60 to 99 mol%, hydroxyalkyl cellulose having 1 to 5 carbon atoms in the alkyl group, and alkyl cellulose are particularly preferably used from the viewpoint of tackiness.

  The content of these resins is preferably 70% by weight or more, more preferably 80% by weight or more based on the total composition of the peeling assist layer (E). If content is 70 weight% or more, a uniform membrane | film | coat can be formed and it becomes possible to peel a heat-sensitive mask layer (B) / cover film (F) without difficulty.

  The peeling assisting layer (E) may contain an infrared absorbing substance and / or a thermally decomposable substance in order to facilitate removal by infrared rays. As the infrared absorbing material and the thermally decomposable material, those described above can be used. Further, a surfactant may be added to improve coatability and wettability.

  The film thickness of the peeling assist layer (E) is preferably 6 μm or less, more preferably 0.1 μm or more and 3 μm or less. If it is 6 micrometers or less, the laser ablation property of the lower thermal mask layer (B) will not be impaired. Moreover, if it is 0.1 micrometer or more, formation of a peeling auxiliary | assistant layer (E) will be easy.

  Here, when peeling the cover film (F) from the photosensitive resin printing plate precursor at a speed of 200 mm / min, the peel force per 1 cm is preferably 4.5 to 200 mN / cm, preferably 9 to 150 mN / cm. cm is more preferable. If it is 4.5 mN / cm or more, it is possible to work without peeling the cover film (F) during the work, and if it is 200 mN / cm or less, the cover film (F) can be peeled without difficulty. Therefore, it is preferable.

  Next, the preferable manufacturing method of the photosensitive resin letterpress original plate used for this invention is demonstrated.

  A first example of the production method is as follows: a photosensitive resin layer (A) on a support, an adhesion adjusting layer (D) if necessary, a thermal mask layer (B), a peeling auxiliary layer (E) if necessary, and a cover film ( F) is a master having a structure in which F) are sequentially laminated. A thermal mask sheet in which the layer (E), the layer (B) and, if necessary, the layer (D) are laminated on the cover film (F) by a sequential coating method, and the photosensitive layer on which the layer (A) is laminated on the support. It can be obtained by laminating a conductive resin sheet. The laminating method is not particularly limited. For example, a method in which the surface of the layer (A) or the layer (D) is swollen with water and / or alcohol, and the photosensitive resin sheet and the thermal mask sheet are bonded together. There are a method in which a high-viscosity liquid having the same or similar composition is poured between a photosensitive resin sheet and a heat-sensitive mask sheet, and the two are bonded together, or a method in which a high-viscosity liquid is pressed at room temperature or while being heated.

  The second example has a structure in which a photosensitive resin layer (A), an adhesive force adjusting layer (D) and a thermal mask layer (B), if necessary, and a peeling assist layer (E) are sequentially laminated on a support. The original version. First, a photosensitive resin sheet obtained by laminating a photosensitive resin layer (A) on a support is coated with a solution in which the components of the layer (D) are dissolved if necessary, and then dried, and then the thermal mask layer (B ) Coating or heating a solution in which the component (1) is dissolved or dispersed. Furthermore, it can be obtained by coating and drying a liquid in which the component of the peeling assisting layer (E) is dissolved as necessary.

  As another method, a thermal mask sheet in which a layer (E) and a layer (B) are sequentially laminated on a release paper as necessary by the same coating method is prepared, and then a layer (A) is laminated on a support. It can also be obtained by peeling the release paper after laminating the conductive resin sheet and the thermal mask sheet so that the layer (A) is in contact with the layer (B). If necessary, the layer (D) may be laminated on the photosensitive resin sheet or the heat-sensitive mask sheet by a coating method, and then both may be laminated to provide the layer (D) between the layers (A) and (B).

  The method for producing the photosensitive resin relief plate precursor is not limited to the above example, and can be produced by combining known coatings, laminates, and the like.

  In the first example, the photosensitive resin printing plate precursor obtained as described above is peeled off from the cover film (F), drawn on the thermal mask layer (B) with an infrared laser, and further a protective layer (C ) Can be used to obtain the drawn photosensitive resin letterpress original plate of the present invention.

  The step of drawing on the thermal mask layer (B) with an infrared laser is a step of scanning and irradiating the thermal mask layer (B) with the infrared laser turned on / off based on image data. When the thermal mask layer (B) is irradiated with an infrared laser, heat is generated by the action of the infrared absorbing substance, and the thermal decomposable compound is decomposed by the action of the heat to remove the thermal mask layer (B). Laser ablation. The laser ablated portion has a greatly reduced optical density and is substantially transparent to ultraviolet light. An image mask capable of forming a latent image on the photosensitive resin layer (A) is obtained by selectively laser ablating the thermal mask layer (B) based on the image data.

  For the infrared laser irradiation, one having an oscillation wavelength in the range of 750 nm to 3000 nm is used. Examples of such lasers include ruby lasers, alexandrite lasers, perovskite lasers, solid state lasers such as Nd-YAG lasers and emerald glass lasers, semiconductor lasers such as InGaAsP, InGaAs and GaAsAl, and dye lasers such as rhodamine dyes. Can be mentioned. A fiber laser that amplifies these light sources with a fiber can also be used. Among them, the semiconductor laser is preferable because it is downsized due to recent technological advances and is economically advantageous over other laser light sources. An Nd-YAG laser is also preferable because it has a high output, is widely used for dentistry and medical purposes, and is economically inexpensive.

  The protective layer (C) is provided by being superimposed on the thermal mask (B ′) side on which the photosensitive resin relief plate is drawn. The protective layer (C) does not need to be integrated with the photosensitive resin relief printing original plate by adhesion or adhesion, and an operation such as laminating may not be performed when the protective layer (C) is provided.

  When the photosensitive resin printing plate precursor has a peeling assisting layer (E) between the cover film (F) and the thermal mask layer (B), the layer (B) is irradiated with infrared laser scanning from the layer (E) side. Drawing can be performed, and the protective layer (C) is provided by being overlaid on the layer (E).

  Further, in the method for producing a resin relief printing plate from the drawn photosensitive resin relief printing plate precursor of the present invention, after removing the protective layer (C) from the drawn photosensitive resin relief printing plate precursor, the wavelength is preferably from the thermal mask (B) side. The entire surface is exposed using 300 to 400 nm ultraviolet light. As the light source, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a metal halide lamp, a xenon lamp, a carbon arc lamp, a chemical lamp, or the like can be used. In order to prevent scratches on the layer (B ′), the protective layer (C) may be laminated again on the drawn heat-sensitive mask layer (B ′) after the exposure until the development step described below. preferable.

  After the exposure, for example, using a brush-type washing machine or a spray-type washing machine, the film is developed with a liquid containing water as a main component, the peeling auxiliary layer (D), the thermal mask remaining at the time of drawing (B ′), and ultraviolet light unexposed. Part of the photosensitive resin layer (A) is removed, and a resin relief printing plate having a relief image can be obtained.

  The developer containing water as a main component may contain tap water, distilled water, or water as a main component and an alcohol having 1 to 6 carbon atoms. Here, the main component means 70% by weight or more. Moreover, what mixed the component of the photosensitive resin layer (A), the adhesive force adjustment layer (D), the thermal mask layer (B), and the peeling auxiliary layer (D) in these liquids can also be used.

  The thermal mask (B) is water-insoluble for the purpose of improving scratch resistance and does not dissolve in a developer composed of water or alcohol. However, since it is thin, it can be physically removed by rubbing with a strong brush such as a PBT (polybutylene terephthalate) brush. At this time, the heat-sensitive mask (B) can be efficiently removed by using a relatively high temperature developing water of 30 ° C. to 70 ° C.

  Thereafter, if necessary, a treatment for drying the developer adhering to the plate surface, post-exposure of the photosensitive resin printing plate material, an adhesive removal treatment, and the like can be performed.

  The resin relief printing plate produced by the production method of the present invention is preferably used as a resin relief printing plate that can be mounted on a printing machine.

  Hereinafter, the present invention will be described in detail with reference to examples.

<Synthesis of water-soluble polyamide resin 1>
10 parts by weight of ε-caprolactam, 90 parts by weight of N- (2-aminoethyl) piperazine and nylon salt of adipic acid and 100 parts by weight of water were placed in a stainless steel autoclave, and the internal air was replaced with nitrogen gas at 180 ° C. The mixture was heated for 1 hour, and then water was removed to obtain a water-soluble polyamide resin 1.

<Synthesis of modified polyvinyl alcohol 1>
In a flask equipped with a condenser, partially saponified polyvinyl alcohol “GOHSENOL” KL-05 (saponification degree: 78.5% to 82.0%, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.), 50 parts by weight, succinic anhydride: 2 parts by weight And 10 parts by weight of acetone were added and heated at 60 ° C. for 6 hours, and then the cooling tube was removed to volatilize acetone. Thereafter, the purification step of eluting unreacted succinic anhydride with 100 parts by weight of acetone was carried out twice, followed by drying under reduced pressure at 60 ° C. for 5 hours to obtain modified polyvinyl alcohol 1 in which succinic acid was ester-bonded to a hydroxyl group. Obtained.

<Preparation of coating liquid composition 1 for photosensitive resin layer (A)>
In a three-necked flask equipped with a stirring spatula and a condenser tube, 7.5 parts by weight of water-soluble polyamide resin 1, 47.5 parts by weight of modified polyvinyl alcohol 1, 11 parts by weight of diethylene glycol, 38 parts by weight of water and ethanol 44 Part by weight was added, and the polymer was dissolved by stirring at 110 ° C. for 30 minutes and then at 70 ° C. for 90 minutes. Subsequently, 3 parts by weight of “Blemmer” G (glycidyl methacrylate, manufactured by Nippon Oil & Fats Co., Ltd.) was added and stirred at 70 ° C. for 30 minutes. Furthermore, 12 parts by weight of “Blenmer” GMR (methacrylic acid adduct of glycidyl methacrylate, manufactured by NOF Corporation), 5 parts by weight of “light ester” G201P (acrylic acid adduct of glycidyl methacrylate, manufactured by Kyoeisha Chemical Co., Ltd.), "Epoxy ester" 70PA (acrylic acid adduct of propylene glycol diglycidyl ether, manufactured by Kyoeisha Chemical Co., Ltd.), 6 parts by weight, "NK ester" A-200 (diacrylate of polyethylene glycol having an average molecular weight of 200, Shin-Nakamura Chemical Co., Ltd.) 5 parts by weight, “Irgacure” 651 (benzyldimethyl ketal, manufactured by Ciba-Geigy) 0.1 parts by weight, “Irgacure” 184 (α-hydroxyketone, manufactured by Ciba-Geigy) 1.5 parts by weight, “Suminol Fast Cyanine Green G conc.” Dex CI Acid Green 25, manufactured by Sumitomo Chemical Co., Ltd.) 0.01 parts by weight, “Direct Sky Blue 6B” (produced by Hamamoto Dye) 0.01 parts by weight, “Formaster” (antifoaming agent, San Nopco) (Manufactured by Co., Ltd.) 0.05 parts by weight, “Tinubin” 327 (UV absorber, manufactured by Ciba-Geigy Co., Ltd.) 0.015 parts by weight, “TTP-44” (bis- {2- (2-ethoxyethoxy) 0.2 parts by weight of carbonyl) ethylthio} octylthiophosphine (manufactured by Sakai Chemical Co., Ltd.) and 0.005 parts by weight of “Q-1300” (ammonium N-nitrosophenylhydroxylamine, manufactured by Wako Pure Chemical Industries, Ltd.) And it stirred for 30 minutes and obtained the coating liquid composition 1 of the photosensitive resin layer (A) with fluidity | liquidity.

<Preparation of adhesive coated substrate 1>
A mixture of 260 parts by weight of “Byron 31SS” (toluene solution of unsaturated polyester resin, manufactured by Toyobo Co., Ltd.) and 2 parts by weight of “PS-8A” (benzoin ethyl ether, manufactured by Wako Pure Chemical Industries, Ltd.) The mixture was heated at 30 ° C. for 2 hours and then cooled to 30 ° C., and 7 parts by weight of ethylene glycol diglycidyl ether dimethacrylate was added and mixed for 2 hours. Further, 25 parts by weight of “Coronate” 3015E (ethyl acetate solution of polyvalent isocyanate resin, manufactured by Nippon Polyurethane Industry Co., Ltd.) and 14 parts by weight of “EC-1368” (industrial adhesive, manufactured by Sumitomo 3M Co., Ltd.) This was added to obtain an adhesive composition 1.

  50 parts by weight of “Gohsenol” KH-17 (polyvinyl alcohol having a saponification degree of 78.5% to 81.5%, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) is mixed with “Solmix” H-11 (alcohol mixture, Nippon Alcohol Co., Ltd.). )) 200 parts by weight and 200 parts by weight of water After dissolving at 70 ° C. for 2 hours, 1.5 parts by weight of “Blenmer” G (glycidyl methacrylate, manufactured by NOF Corporation) was added to After mixing for a while, 3 parts by weight of a copolymer (made by Kyoeisha Chemical Co., Ltd.) having a (dimethylaminoethyl methacrylate) / (2-hydroxyethyl methacrylate) weight ratio of 2/1, “Irgacure” 651 (benzyldimethyl ketal, Ciba・ Geigy Co., Ltd. 5 parts by weight, "epoxy ester" 70PA (propylene glycol diglycidyl ether addition of acrylic acid) 21 parts by weight of Kyoeisha Chemical Co., Ltd.) and 20 parts by weight of ethylene glycol diglycidyl ether dimethacrylate were added and mixed for 90 minutes. ) 0.1 part by weight was added and mixed for 30 minutes to obtain an adhesive composition 2.

  The adhesive layer composition 1 is applied on a 250 μm-thick “Lumirror” T60 (polyester film, manufactured by Toray Industries, Inc.) with a bar coater so that the film thickness becomes 40 μm after drying, and placed in an oven at 180 ° C. for 3 minutes. After removing the solvent, the adhesive layer composition 2 was coated thereon with a bar coater so as to have a dry film thickness of 30 μm and dried in an oven at 160 ° C. for 3 minutes to obtain an adhesive coated substrate 1.

<Manufacture of photosensitive resin sheet 1>
After the adhesive-coated substrate 1 is exposed to 1000 mJ / cm ² from the adhesive-coated side with an ultrahigh-pressure mercury lamp, the coating solution composition 1 for the photosensitive resin layer (A) is coated with the adhesive-coated substrate 1 on the adhesive-coated surface. And dried in an oven at 60 ° C. for 5 hours to obtain a photosensitive resin sheet 1 having a thickness of about 900 μm including the substrate. The thickness of the photosensitive resin sheet 1 was adjusted by installing a spacer having a predetermined thickness on the substrate and scraping out the coating liquid composition 1 in a portion protruding from the spacer with a horizontal metal scale.

<Preparation of coating liquid composition 2 for peeling auxiliary layer (E)>
11 parts by weight of “GOHSENOL” AL-06 (polyvinyl alcohol having a saponification degree of 91% to 94%, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) 55 parts by weight of water, 14 parts by weight of methanol, 10 parts by weight of n-propanol and n- It was made to melt | dissolve in 10 weight part of butanol, and the coating liquid composition 2 for peeling auxiliary | assistant layer (E) was obtained.

<Preparation of coating liquid composition 3 for thermal mask layer (B)>
“MA100” (carbon black, manufactured by Mitsubishi Chemical Corporation) 23 parts by weight, “Dianal” BR-95 (alcohol-insoluble acrylic resin, manufactured by Mitsubishi Rayon Co., Ltd.) 15 parts by weight, plasticizer ATBC (acetyl citrate) Carbon black dispersion 1 was prepared by kneading and dispersing 6 parts by weight of tributyl (manufactured by J Plus Co., Ltd.) and 30 parts by weight of methyl isobutyl ketone using a three-roll mill. In dispersion 1, 20 parts by weight of “Araldite” 6071 (epoxy resin, manufactured by Asahi Ciba), 27 parts by weight of “Uban” 2061 (melamine resin, manufactured by Mitsui Chemicals), “light ester” P-1M ( 0.7 parts by weight of phosphoric acid monomer (manufactured by Kyoeisha Chemical Co., Ltd.) and 140 parts by weight of methyl isobutyl ketone were added and stirred for 30 minutes. Thereafter, methyl isobutyl ketone was further added so that the solid content concentration was 33% by weight to obtain a coating liquid composition 3 for the thermal mask layer (B).

<Preparation of Coating Solution Composition 4 for Adhesive Strength Adjustment Layer (D)>
“Gosenol” KL-05 (polyvinyl alcohol having a saponification degree of 78% to 82%, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) 10 parts by weight 40 parts by weight of water, 20 parts by weight of methanol, 20 parts by weight of n-propanol and n- It was made to melt | dissolve in 10 weight part of butanol, and the coating liquid composition 4 for adhesive force adjustment layers (D) was obtained.

<Manufacture of thermal mask element 1>
On a 100 μm thick polyester film “Lumirror” S10 (manufactured by Toray Industries, Inc.), the coating liquid composition 2 was applied using a bar coater to a dry film thickness of 0.25 μm, and at 100 ° C. for 25 seconds. It dried and the laminated body of peeling auxiliary | assistant layer (E) / cover film (F) was obtained. On the peeling auxiliary layer (E) side of the laminate thus obtained, the coating liquid composition 3 was applied to a dry film thickness of 2 μm using a bar coater, and dried at 140 ° C. for 30 seconds. A laminate of thermal mask layer (B) / peeling auxiliary layer (E) / cover film (F) was obtained. On the thermal mask layer (B) side of the laminate thus obtained, the coating liquid composition 4 was applied using a bar coater so that the dry film thickness was 1 μm, and dried at 180 ° C. for 30 seconds. A thermal mask element 1 which is a laminate of adhesion adjusting layer (D) / thermal mask layer (B) / peeling auxiliary layer (E) / cover film (F) was obtained. The optical density (orthochromatic filter, transmission mode) of the thermal mask element 1 was 3.6.

<Manufacture of photosensitive resin printing plate precursor 1>
The coating liquid composition 1 is developed on the photosensitive resin layer (A) of the photosensitive resin sheet 1, and the adhesive layer (D) is applied to the thermal mask element 1 on the coating composition 1. The photosensitive resin layer (A) is placed in contact with the laminate and laminated with a calender roll heated to 80 ° C., and the adhesive-coated substrate 1 / photosensitive resin layer (A) / adhesive strength adjusting layer (D) / The photosensitive resin printing plate precursor 1 laminated in the order of the heat-sensitive mask layer (B) / release auxiliary layer (E) / cover film (F) was obtained. The clearance of the calendar roll was adjusted so that the thickness of the laminate after peeling the cover film (F) from the original plate 1 was 950 μm. The unfolded coating liquid composition 1 is allowed to stand for 1 week after laminating, whereby the remaining solvent is naturally dried to form an additional photosensitive resin layer (A).

<Manufacture of drawn photosensitive resin printing plate precursor>
After peeling the cover film (F) from the photosensitive resin printing plate precursor 1, an external drum type plate setter “CDI SPARK” (manufactured by Esco Graphics Co., Ltd.) equipped with a fiber laser having a light emitting region in the infrared, It was mounted so that the support side was in contact with the drum, and was drawn on the thermal mask layer (B) under the conditions of a laser output of 9 W and a drum rotation number of 700 rpm. After the drawing was completed, a protective layer (C) was provided on the peeling assist layer (E) to prepare a drawn photosensitive resin letterpress original plate.

<Characteristic evaluation of drawn photosensitive resin letterpress original plate>
(I) Number of scratches on the thermal mask layer (B ′)
In the same manner as the method for producing the drawn photosensitive resin relief printing plate precursor described above, only the thermal mask layer (B) having a peripheral width of 2 cm is removed from the photosensitive resin printing original plate 1 having a size of 30 × 30 cm, and the central portion is 28 × 28 cm. The heat-sensitive mask layer (B ′) was drawn so as to leave a printed photosensitive resin letterpress original plate for evaluation. Without placing any force on the printed photosensitive resin letterpress original plate with 3 sides of the photosensitive resin letterpress original plate of 30 × 60 cm with the support on the lower side so that the short sides overlap, After three photosensitive resin relief printing plate precursors were reciprocated 10 times in the long side direction, the evaluation photosensitive photosensitive resin relief printing plate precursor was placed on a trace table, the number of locations where transmitted light leaked was counted, and a thermal mask layer ( The number of scratches was B ′).
(Ii) Number of defects of resin relief printing plate After confirming the number of scratches on the above-mentioned thermal mask layer (B ′), the entire surface is exposed from the thermal mask layer (B ′) side with an ultra-high pressure mercury lamp (manufactured by Oak Co., Ltd.). Exposure amount: 1500 mJ / cm ² ), and then developed with tap water at 35 ° C. for 1.5 minutes using a brush type developing machine FTW500II (manufactured by Toray Industries, Inc.) equipped with a PBT (polybutylene terephthalate) brush. The thermal mask layer (B) and the photosensitive resin layer (A) that was not photocured were removed. When the drawn heat-sensitive mask layer (B ′) has penetrating scratches, ultraviolet rays are transmitted and the photosensitive resin layer (A) is photocured and insolubilized, so that it remains on the support. The number of photocured portions of the photosensitive resin layer (A) was counted within the range of 28 × 28 cm in which the heat-sensitive mask layer (B ′) was left at the time of drawing, and was defined as the number of defects of the resin relief printing plate.

Example 1
After peeling the cover film from the photosensitive resin printing plate precursor 1, drawing is performed by the method described above, and a high-quality paper having a weight of 66 g / m ² is provided as a protective layer (C1) to produce a photosensitive resin relief plate precursor 1 for evaluation. did. Plate making was performed by the above-described method to prepare a resin relief printing plate.

(Example 2)
A drawn photosensitive resin relief plate precursor 2 was produced in the same manner as in Example 1 except that a protective layer (C2) made of a nylon nonwoven fabric having a weight of 80 g / m ² was provided as a protective layer. Plate making was performed by the above-described method to prepare a resin relief printing plate.

(Example 3)
A drawn photosensitive resin letterpress original plate 3 was prepared in the same manner as in Example 1 except that a protective layer (C3) made of a PET film having a weight of 127 g / m ² was provided as a protective layer. Plate making was performed by the above-described method to prepare a resin relief printing plate.

(Comparative Example 1)
After peeling the cover film from the photosensitive resin printing plate precursor 1, plate making was performed without providing the protective layer (C) to prepare a resin relief printing plate.

  Table 1 shows the evaluation results of the above examples and comparative examples.

  In Examples 1 to 3 provided with the protective layers (C1) to (C3), the number of scratches on the heat-sensitive mask layer (B ′) and the number of defects on the resin relief printing plate were small, whereas the protective layer (C) was used. In the comparative example that was not provided, both the number of scratches and the number of defects increased.

Claims (4)

1. A drawn photosensitive resin relief printing plate precursor having at least a photosensitive resin layer (A), a drawn thermal mask layer (B ′), and a protective layer (C) in this order on a support. The drawn photosensitive resin relief printing plate precursor according to claim 1, wherein the drawn thermal mask layer (B ') is insoluble in water. Rendered photosensitive resin relief printing plate precursor as claimed in claim 1 in which the weight of the protective layer (C) is characterized in that it is a 25~200g / m ^2. (1) A step of drawing on a heat-sensitive mask layer (B) of a photosensitive resin relief printing plate precursor having at least a photosensitive resin layer (A) and a heat-sensitive mask layer (B) on a support, (2) a drawn heat-sensitive mask A method for making a photosensitive resin relief plate precursor comprising at least a step of exposing from the layer (B ′) side, (3) a step of developing, wherein (1) after the drawing step, (2) before the exposure step, and / or (2) After the exposure process (3) Before the development process, a protective layer (C) is provided on the drawn heat-sensitive mask layer (B ′), and the plate making method of the photosensitive resin relief printing plate precursor is characterized.