JP2009058901A - Multilayer laminate for producing letterpress plate and method for producing letterpress plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a multilayer laminate for producing a letterpress plate capable of reducing the effect of oxygen in the air on a photosensitive resin layer in exposure and capable of obtaining a good pattern after development, with respect to a multilayer laminate for producing a letterpress plate including a photosensitive resin layer and a mask layer, and to provide a method for producing a letterpress plate using the multilayer laminate. <P>SOLUTION: The multilayer laminate for producing a letterpress plate is obtained by laminating on (A) a support (B) a photosensitive resin layer and (C) a mask layer in this order, wherein the mask layer comprises (a) at least one infrared absorbing material, (b) at least one ultraviolet absorbing material and (c) polyvinyl butyral. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a multilayer laminate for producing a relief printing plate and a method for producing a relief printing plate.

  Conventionally, a relief printing plate is provided with a photosensitive resin layer on a support, and a film (negative mask) having a negative pattern of an image such as characters and images to be printed is placed on the photosensitive resin layer. It was manufactured by exposing the photosensitive resin layer with active rays through and developing the exposed photosensitive resin layer. However, in the method of manufacturing a relief printing plate using a negative mask, if the final image of the negative mask needs to be corrected, the entire negative mask needs to be recreated. It has been pointed out that there is a problem and that the negative mask easily changes in dimensions due to changes in temperature and humidity.

In order to solve such problems, a relief printing original plate in which a mask layer, which is an infrared sensitive material layer, is formed on the photosensitive resin layer, the mask layer is patterned with infrared laser light, and the patterned mask layer is formed. A method for producing a relief printing plate using a negative mask is known (for example, Patent Documents 1 to 5).
JP 9-166875 A Japanese Patent Laid-Open No. 11-153865 JP 2001-080225 A Japanese Patent No. 2916408 Japanese Patent No. 3511022

  However, in the method for producing a relief printing plate described in Patent Documents 1 to 5, after the patterning of the mask layer, the photosensitive resin layer in the portion where the mask layer has been removed is affected by oxygen in the air and activated. It has been known that when a line is exposed, it does not fully polymerize.

  The present invention has been made in view of the above problems, and is a multi-layer laminate for producing a relief printing plate having a photosensitive resin layer and a mask layer, and in exposure, oxygen in the air with respect to the photosensitive resin layer It is an object of the present invention to provide a multilayer laminate for producing a relief printing plate capable of reducing the influence of the above and capable of obtaining a good pattern after development, and a method for producing a relief printing plate using the same.

  The present inventors are a multilayer laminate for producing a relief printing plate in which a support, a photosensitive resin layer, and a mask layer are laminated in this order, and as a binder resin contained in the mask layer, When polyvinyl butyral was used, it discovered that the said subject could be solved and came to complete this invention.

  Specifically, the present invention provides the following.

  In the first aspect of the present invention, (B) a photosensitive resin layer and (C) a mask layer are laminated in this order on (A) a support, and the mask layer comprises (a) at least A multilayer laminate for producing a relief printing plate, comprising one kind of infrared absorbing substance, (b) at least one kind of ultraviolet absorbing substance, and (c) polyvinyl butyral.

  The second aspect of the present invention is a method for producing a relief printing plate for producing a relief printing plate from the multilayer laminate for producing a relief printing plate of the present invention, wherein the mask layer is irradiated with infrared laser light. A step of patterning; a step of exposing the photosensitive resin layer with ultraviolet light through the patterned mask layer; and a step of removing the mask layer and developing the photosensitive resin layer after exposure. And a method for producing a relief printing plate.

  According to the present invention, since polyvinyl butyral is used as the binder resin constituting the mask layer, even when the mask layer is selectively removed using infrared laser light, the photosensitive resin at the portion where the mask layer is removed The layer is not affected by oxygen, and the polymerization reaction by ultraviolet irradiation proceeds smoothly. Thereby, a fine and favorable pattern can be obtained after development.

  Hereinafter, embodiments of the present invention will be described in detail. In addition, although this invention is demonstrated about the flexographic printing which is an example of letterpress printing, this invention is not limited to this.

<Multilayer laminate for flexographic printing plate production>
The multilayer laminate for producing a flexographic printing plate, which is a multilayer laminate for producing a relief printing plate according to the present invention, comprises (A) a support, (B) a photosensitive resin layer, and (C) a mask layer in this order. It is formed by lamination, and (D) a cover film may be laminated on the upper layer of the mask layer as necessary.

[(A) Support]
The support used in the multilayer laminate for producing a flexographic printing plate of the present invention is conventionally used as a support for a flexographic printing plate, and has mechanical strength and physical properties suitable for various printing conditions. It can be formed by arbitrarily selecting from satisfying materials such as metal sheet, plastic film, paper, and composites thereof. Examples of such materials include polymeric films formed from addition polymerization polymers and linear condensation polymers; foams; woven and non-woven fabrics such as glass fiber fabrics; and metals such as steel and aluminum. be able to. As such a support, a polyethylene or polyester film is preferably used, and a polyethylene terephthalate film is more preferably used. The support is usually formed into a film or sheet having a thickness of 50 μm to 300 μm, preferably 75 μm to 200 μm.

  The support may also have a thin adhesion promoting layer between the photosensitive resin layer, if necessary. As this adhesion promotion layer, the layer which consists of a mixture of an acrylic resin and polyisocyanate can be mentioned, for example.

[(B) Photosensitive resin layer]
Although it does not specifically limit as a photosensitive resin layer, It is preferable that binder resin, a photopolymerizable monomer, and a photoinitiator are included.

(Binder resin)
Examples of the binder resin contained in the photosensitive resin layer include various resins such as styrene, olefin, polyester, polyurethane, 1,2-polybutadiene, vinyl chloride, and polyamide. Among these, particularly preferable binder resins include styrene-based elastomers, and specifically include styrene / butadiene / styrene block copolymers and styrene / isoprene / styrene block copolymers, and hydrogenated products thereof. it can. The binder resin is blended in the photosensitive resin composition at a ratio of 30% by mass to 95% by mass, preferably 50% by mass to 85% by mass. When the blending amount is 30% by mass or more, a composition excellent in rubber elasticity can be obtained, and when the blending amount is 95% by mass or less, a pattern with excellent reproducibility can be formed.

(Photopolymerizable monomer)
The photopolymerizable monomer is not particularly limited as long as it is a monomer capable of crosslinking the binder resin and has a good compatibility with the binder resin. Specific examples include acrylic acid esters, acrylamides, methacrylic acid esters, methacrylamides, allyl compounds, vinyl ethers, vinyl esters, styrenes, and crotonic acid esters, and addition polymerizable unsaturated bonds. Selected from compounds having The said compound may be used independently and may be used in combination of 2 or more type. Moreover, it is preferable that it is 3 to 80 mass parts with respect to 100 mass parts of said binder resins, and, as for a compounding quantity, it is still more preferable that they are 5 to 20 mass parts. When the amount is 3 parts by mass or more, a pattern with excellent reproducibility can be obtained, and when it is 80 parts by mass or less, good rubber elasticity can be obtained.

(Photopolymerization initiator)
The photopolymerization initiator can be arbitrarily selected from known compounds commonly used in photosensitive resin compositions, but benzoin, phenone, and anthraquinone are particularly preferable. Specifically, benzoin-based photopolymerization initiators include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin-n-propyl ether, α-methylbenzoin, α-ethylbenzoin, α-phenylbenzoin, and α-allyl. Benzoin: Examples of the phenone photopolymerization initiator include benzophenone, ω-bromoacetophenone, and acetophenone; Examples of the anthraquinone photopolymerization initiator include anthraquinone, chloroanthraquinone, methylanthraquinone, and ethyl anthraquinone. These photopolymerization initiators may be used alone or in combination of two or more. The blending amount of the photopolymerization initiator is preferably 0.1 parts by mass or more and 5 parts by mass or less, and more preferably 0.5 parts by mass or more and 2 parts by mass or less with respect to 100 parts by mass of the binder resin. . When the blending amount is 0.1 parts by mass or more, practical sensitivity can be obtained, and when it is 5 parts by mass or less, a good pattern can be obtained.

(Other ingredients)
If necessary, dyes, pigments, polymerization inhibitors, antioxidants, photodegradation inhibitors, and the like can be added to the photosensitive resin layer to improve its performance. Furthermore, in order to improve the wear resistance, a resin compatible with the binder resin such as a polyamide resin, an epoxy resin, and a polyurethane resin may be mixed.

(Photosensitive resin layer thickness)
In the multilayer laminate for producing a flexographic printing plate of the present invention, the thickness of the photosensitive resin layer is preferably 0.4 mm or more and 10 mm or less, and more preferably 0.5 mm or more and 7.5 mm or less. What is necessary is just to select the film thickness of the photosensitive resin layer suitably according to the kind of to-be-printed body and the printing machine to be used within the said film thickness range.

[(C) Mask layer]
In the multilayer laminate for producing a flexographic printing plate of the present invention, the mask layer is (a) at least one infrared absorbing substance, (b) at least one ultraviolet absorbing substance, and (c) a binder resin. Contains polyvinyl butyral.

((A) Infrared absorbing substance)
The infrared absorbing material contained in the mask layer plays a role of absorbing the infrared laser light and generating heat to melt the mask layer. The infrared absorbing material is not particularly limited as long as it absorbs infrared laser light. Black pigments such as carbon black, aniline black, and cyanine black; phthalocyanine and naphthalocyanine-based green pigments; graphite, iron Powder, diamine-based metal complex, dithiol-based metal complex, phenolthiol-based metal complex, mercaptophenol-based metal complex, crystal water-containing inorganic compound, copper sulfate, chromium sulfide, and silicate compound; chromium oxide, titanium oxide, vanadium oxide Metal oxides such as manganese oxide, iron oxide, cobalt oxide, and tungsten oxide; hydroxides and sulfates of these metals; metal powders of bismuth, iron, magnesium, and aluminum can be used. Among these, it is preferable to use carbon black from the viewpoint of photothermal conversion, economic efficiency, and handleability. Carbon black can be used in a wide range of particle diameters of 10 nm or more and 100 nm or less. The smaller the particle diameter, the higher the sensitivity to infrared rays.

  In addition to the above substances, dyes that absorb infrared rays or near infrared rays can also be used as infrared absorbing materials.

  Any dye may be used as long as it has a maximum absorption wavelength in the range of 700 nm to 20000 nm. Preferred dyes include cyanine, phthalocyanine, phthalocyanine metal complex, naphthalocyanine. , Naphthalocyanine metal complex, dithiol metal complex, naphthoquinone, anthraquinone, indophenol, indoaniline, pyrylium, thiopyrylium, squarylium, croconium, diphenylmethane, triphenylmethane, triphenylmethane Phthalide, triallylmethane, phenothiazine, phenoxazine, fluoran, thiofluorane, xanthene, indolylphthalide, spiropyran, azaphthalide, chromenopyrazole, leuco -Lamin, rhodamine lactam, quinazoline, diazaxanthene, bislactone, fluorenone, monoazo, ketoneimine, diazo, polymethine, oxazine, nigrosine, bisazo, bisazostilbene, bisazooxa Diazole, bisazofluorenone, bisazohydroxyperinone, azochrome complex, trisazotriphenylamine, thioindigo, perylene, nitroso, 1: 2 type metal complex, intermolecular CT, Quinoline-based, quinophthalone-based, and fulgide-based acid dyes, basic dyes, pigments, and oil-soluble dyes; triphenylmethane-based leuco pigments; cationic dyes; azo-based disperse dyes; benzothiopyran-based spiropyrans; ; Indanthrone; Phenol Tarein; sulfo phthalein, ethyl violet, methyl orange; can be given as well as the gym loss betaine; fluorescein; methyl viologen; methylene blue.

  Among these infrared absorbing materials, cyanine dyes, azurenium dyes, squarylium dyes, croconium dyes, azo disperse dyes, bisazostilbene dyes, naphthoquinone dyes having a maximum absorption wavelength in the range of 750 nm to 2000 nm. Dyes, anthraquinone dyes, perylene dyes, phthalocyanine dyes, naphthalocyanine metal complex dyes, polymethine dyes, dithiol nickel complex dyes, indoaniline metal complex dyes, intermolecular CT dyes, benzothiopyran spiropyran, and nigrosine dyes Etc. can be used suitably. These infrared absorbing materials may be used alone or in combination of two or more. Further, by using two or more types of infrared absorbing materials having different absorption wavelengths, it is possible to cope with two or more types of lasers having different transmission wavelengths.

  The content of the infrared absorbing material is not particularly limited, but is preferably 0.001 to 10 parts by mass, and 0.05 to 5 parts by mass with respect to 100 parts by mass of the binder resin. More preferably, it is as follows. When the content is 0.001 part by mass or more, the sensitivity to infrared laser light can be sufficiently improved, and when the content is 10 parts by mass or less, the film flexibility can be maintained well.

((B) UV-absorbing substance)
The ultraviolet absorbing substance is not particularly limited as long as it absorbs ultraviolet rays, but carbon black and graphite are preferably used. Here, since carbon black and graphite have the above-described action as an infrared absorbing substance and the action as an ultraviolet absorbing substance, and are preferable from the viewpoint of economy and handling, they can be used particularly suitably.

  The ultraviolet absorbing substance is preferably added so that the optical density of the mask layer at a predetermined wavelength is 2.0 or more. Specifically, it is preferably 5 parts by mass or more and 40 parts by mass or less, and more preferably 15 parts by mass or more and 25 parts by mass or less with respect to 100 parts by mass of the binder resin. When the content is 5 parts by mass or more, ultraviolet rays can be sufficiently shielded, and when the content is 40 parts by mass or less, the coating flexibility can be favorably maintained. Moreover, when making an infrared absorptive substance and an ultraviolet absorptive substance into the same substance, it is preferable that they are 10 to 30 mass parts with respect to 100 mass parts of binder resin.

((C) polyvinyl butyral)
In the present invention, the mask layer contains polyvinyl butyral as a binder resin. When the mask layer of the present invention is selectively removed by irradiation with infrared laser light, a residual film made of the constituent material of the mask layer is formed on the photosensitive resin layer. Here, since the residual film can block the permeation of oxygen in the air, it can be prevented that the polymerization reaction of the photosensitive resin layer in the portion where the mask layer is removed is hindered by the oxygen in the air. .

  The content of polyvinyl butyral in the mask layer is preferably 70% by mass or more and 90% by mass or less. When the content of polyvinyl butyral is 70% by mass or more, the flexibility of the mask layer can be kept good, and oxygen remaining in the remaining film remaining on the photosensitive resin layer after selectively removing the mask layer is blocked. The performance can be kept good. In addition, when the content is 90% by mass or less, the content of the infrared absorbing material, the ultraviolet absorbing material, or the like can be sufficiently maintained, the sensitivity to the infrared laser beam can be sufficiently maintained, and the ultraviolet ray can be prevented. It can be shielded sufficiently.

  In the present invention, the molecular weight of polyvinyl butyral used for the mask layer is not particularly limited, but is preferably 40000 or more. When the molecular weight of polyvinyl butyral is 40000 or more, the film flexibility can be kept good.

(Other ingredients)
In the present invention, a surfactant, a dispersant, a plasticizer, an adhesion improver, a coating aid, and the like can be added to the mask layer as desired. The plasticizer is added to suppress the generation of wrinkles when the multilayer laminate for producing a flexographic printing plate of the present invention is bent or bent. Examples of the plasticizer include triphenyl phosphite, dimethyl phthalate, diethyl phthalate, dicyclohexyl phthalate, ethylene glycol dibenzoate, glyceryl carbonate, polyethylene glycol, tributyl citrate, and urethane oligomer. Further, as the surfactant, a fluorine-based surfactant is preferable.

(Thickness of mask layer)
The thickness of the mask layer is preferably such that it can be removed quickly when irradiated with infrared laser light and can effectively block ultraviolet rays. Specifically, it is preferably 0.05 μm or more and 20 μm or less, and more preferably 0.1 μm or more and 10 μm or less.

[(D) Cover film]
The cover film of the multilayer laminate for producing a flexographic printing plate of the present invention is not particularly limited, and a conventionally known cover film used for the multilayer laminate for producing a relief printing plate can be used. That is, as a cover film, polyethylene, polypropylene, polyethylene terephthalate, polyethylene-2,6-naphthalate, nylon 6, nylon 4, nylon 66, nylon 12, polyvinyl chloride, polyvinylidene chloride, polyetherimide, polysulfone, polyphenylene A film containing a resin such as sfido and polyphenylene oxide can be used. Among these, polyethylene terephthalate and polyethylene-2,6-naphthalate can be preferably used, but polyethylene terephthalate is particularly preferable in terms of excellent flexibility and excellent dimensional stability. The above resins may be used alone or in combination. The thickness of the cover film is preferably from 50 μm to 400 μm, and more preferably from 75 μm to 300 μm. In addition, you may form a peeling layer between a cover film and a mask layer as needed.

[Production method of multilayer laminate for flexographic printing plate production]
As a method for producing the multilayer laminate for producing a flexographic printing plate of the present invention, a conventionally known method can be adopted and is not particularly limited. Specifically, for example, it is manufactured by forming a photosensitive resin layer on a support and then forming a mask layer by a coating or lamination technique. The mask layer is generally formed by applying a mask layer forming composition containing an infrared absorbing material, an ultraviolet absorbing material, polyvinyl butyral, and a solvent on a cover film. At this time, the composition for forming a mask layer can be applied using any coating technique including spray coating. Moreover, a mask layer can also be formed by apply | coating the composition for mask layer formation on the photosensitive resin layer.

<Method for producing flexographic printing plate>
The method for producing a flexographic printing plate, which is a method for producing a relief printing plate according to the present invention, is a method for producing a flexographic printing plate from a multilayer laminate for producing a flexographic printing plate according to the present invention. The step of patterning (step (1)), the step of exposing the photosensitive resin layer with ultraviolet rays through the patterned mask layer (step (2)), the mask layer is removed, and the photosensitivity after exposure And a step of developing the functional resin layer (step (3)).

  In the step (1), the infrared laser used for patterning the mask layer is not particularly limited, but an infrared laser capable of irradiating infrared laser light having a wavelength of 750 nm or more and 2000 nm or less can be used. . Specifically, argon ion laser, krypton ion laser, helium-neon laser, helium-cadmium laser, ruby laser, glass laser, glass laser, titanium laser, sapphire laser, dye laser, nitrogen laser, metal vapor laser, semiconductor laser , And various lasers such as a YAG laser, which are suitable for conditions can be used. Among these infrared lasers, a semiconductor laser having a wavelength of 750 to 880 nm and a Nd-YAG laser having a wavelength of 1060 nm can be preferably used. These infrared laser generation units are controlled by a computer together with a drive system unit, and by selectively irradiating infrared laser light onto a mask layer on a photosensitive resin layer, a multilayer laminate for producing a flexographic printing plate An image can be drawn on top.

  In the step (2), it is preferable to use an ultraviolet ray having a wavelength range of 150 nm or more and 400 nm or less as the ultraviolet ray for exposing the photosensitive resin layer. Examples of such an ultraviolet light source include a high-pressure mercury lamp, an ultraviolet fluorescent lamp, a carbon arc lamp, and a xenon lamp. In order to further improve the stability of the exposed relief image with respect to washing out uncured portions during development in step (3), the entire surface may be exposed from the support side in step (2). .

  In step (3), the mask layer and the unexposed photosensitive resin layer are dissolved and removed by the developer. The developer used for development is not particularly limited as long as it can dissolve the mask layer and the unexposed photosensitive resin layer, and any of organic solvents, water, and aqueous or semi-aqueous solutions may be used. Good. The selection of the developer can be appropriately performed according to the chemical properties of the resin to be removed. Suitable organic solvent developers include aromatic or aliphatic hydrocarbon solvents, aromatic or aliphatic halohydrocarbon solvents, or mixtures of these solvents with suitable alcohols. Further, as a suitable semi-aqueous solution, a solution containing water, an organic solvent miscible with water, and an alkaline material can be mentioned, and as a suitable aqueous solution, water, an alkaline material and Can be mentioned.

  Specific examples of the developer include esters such as heptyl acetate and 3-methoxybutyl acetate; hydrocarbons such as petroleum fractions, toluene and decalin; chlorine-based solvents such as tetrachloroethylene; monoethanolamine, diethanolamine, And amines such as triethanolamine; and aqueous solutions such as sodium hydroxide, potassium hydroxide, sodium carbonate, and ammonia. A mixture of these solvents with alcohols such as propyl alcohol, butyl alcohol, and pentyl alcohol can also be used. During development, the exposed multilayer laminate for manufacturing a flexographic printing plate may be immersed in the developer, or the developer may be sprayed from a nozzle onto the multilayer stack for manufacturing a flexographic printing plate after exposure. Also good.

  In the method for producing a relief printing plate of the present invention, when the mask layer is patterned in the step (1), a residual film made of the constituent material of the mask layer is formed on the photosensitive resin layer in a portion where the mask layer is removed. Is done. Here, since the residual film contains polyvinyl butyral, the residual film sufficiently shields oxygen, and the photosensitive resin layer can be prevented from being affected by oxygen.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated, this invention is not limited to a following example at all.

<Example 1>
“But Buter B76” (polyvinyl butyral, manufactured by Solusia) was dissolved in a toluene / ethanol mixed solvent (toluene / ethanol = 1/1) to prepare a 10% by mass homogeneous solution. To this, “MHI Black # 217” (carbon black, pigment content concentration of 30% by mass, manufactured by Mikuni Dye Co., Ltd.) was added so that the carbon black was 30 parts by mass with respect to 100 parts by mass of polyvinyl butyral. It was set as the composition. Subsequently, the said composition for mask layer formation was apply | coated on the cover film which consists of a polyethylene terephthalate film with a thickness of 100 micrometers, and it dried for 5 minutes at 80 degreeC, and obtained the mask layer with a film thickness of 2 micrometers.

  "D-1155" (styrene-butadiene copolymer, mass average molecular weight 240000, manufactured by JSR Elastomer Co., Ltd.) 100 parts by mass, "Nissau PB-1000" (1,2-polybutadiene, mass average molecular weight 1000, manufactured by Nisso Corporation) 70 parts by mass, 10 parts by mass of trimethylolpropane acrylate, 3 parts by mass of methoxyphenylacetone, 0.05 parts by mass of 2,6-tert-butyl-4-hydroxyltoluene, “oil blue # 503” (dye, manufactured by Orient Chemical Co., Ltd.) ) 0.002 part by mass and 0.2 part by mass of tetrahydrofuran were mixed to prepare a photosensitive resin composition. The photosensitive resin composition is pressed into an extruder with a high viscosity pump, and while being kneaded in the extruder, the photosensitive resin composition is extruded from a T-die to a thickness of 1.7 mm onto a polyethylene terephthalate sheet serving as a support. A layer was obtained. The mask layer and the photosensitive resin layer were laminated using a laminating roller to prepare a multilayer laminate for producing a relief printing plate.

<Comparative Example 1>
For producing a relief printing plate in the same manner as in Example 1 except that “Macromelt 6900” (polyamide resin, manufactured by Henkel) was used instead of “Butt Bar B76” used in the mask layer forming composition. A multilayer laminate was produced.

<Comparative example 2>
In the same manner as in Example 1 except that “Smitate HF51” (ethylene-vinyl acetate copolymer, manufactured by Sumitomo Chemical Co., Ltd.) was used instead of “Butt Bar B76” used in the composition for forming a mask layer. A composition for forming a mask layer was prepared. Next, the composition for forming a mask layer was applied on a cover film made of a polyethylene terephthalate film having a thickness of 100 μm and dried at 80 ° C. for 5 minutes to form a mask layer having a thickness of 2 μm. Carbon black was not uniformly dispersed, and a uniform mask layer could not be formed.

<Evaluation>
The multilayer laminate for producing a relief printing plate of Example 1 and Comparative Example 1 was back-exposed from the support side at 75 mJ / cm ² with an ultraviolet lamp having a center wavelength of 370 nm. Next, the cover film of the multilayer laminate for producing a relief printing plate is peeled off, fixed on the drum of a NIR laser writing apparatus (“CDI-spark”, manufactured by Esco Graphics), rotated at 800 rpm, and energy of 19 W The NIR laser was used to irradiate the laser so that the resolution was 2540 dpi, and the mask layer was selectively removed.

Next, main exposure was performed from the mask layer side at 10,000 mJ / cm ² with an ultraviolet lamp having a center wavelength at 370 nm. Development was performed for 4 minutes at a liquid temperature of 25 ° C. using an aromatic hydrocarbon developer “FDO-S2” (manufactured by Tokyo Ohka Kogyo Co., Ltd.) as a developer. No redeposition of development residue or the like was observed on the obtained plate surface. After the development processing, the film is dried at 55 ° C. for 50 minutes, and then subjected to post-processing using an ultraviolet lamp having a central wavelength at 250 nm, and further post-exposure is performed at 3000 mJ / cm ² using an ultraviolet lamp having a central wavelength at 370 nm. A letterpress printing plate was obtained. The obtained relief printing plate was observed with an electron microscope, and 150 lpi minimum complete reproduction halftone dot% was evaluated.

  From Table 1, it can be seen that in Example 1 using polyvinyl butyral as the resin contained in the mask layer, a halftone dot having a smaller size than that of Comparative Example 1 using polyamide resin is reproduced. From this result, it can be seen that in the multi-layer laminate for producing a relief printing plate of the present invention, the photosensitive resin layer is hardly affected by oxygen and a pattern with high resolution can be obtained.

Claims (3)

(A) On the support, (B) a photosensitive resin layer and (C) a mask layer are laminated in this order,
The mask layer is
(A) at least one infrared absorbing substance,
A multilayer laminate for producing a relief printing plate, comprising (b) at least one UV-absorbing substance, and (c) polyvinyl butyral.   The multilayer laminate for producing a relief printing plate according to claim 1, wherein the photosensitive resin layer contains a binder resin, a photopolymerizable monomer, and a photopolymerization initiator. A method for producing a relief printing plate for producing a relief printing plate from the multilayer laminate for producing a relief printing plate according to claim 1 or 2,
Patterning the mask layer with infrared laser light;
Exposing the photosensitive resin layer with ultraviolet rays through the patterned mask layer;
Removing the mask layer, and developing the photosensitive resin layer after the exposure.