JP2007268745A - Layered body for printing base material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cylindrical layered body for a printing base material which has a high resistance to ink used in a printing process and excellent cushioning properties. <P>SOLUTION: The cylindrical layered body for the printing base material disclosed herein includes a sheet which has a film and resin cured matter which is provided on at least one surface of the film so that it forms an indented pattern. The sheet is stacked cylindrically in a plurality of layers so that the resin cured matter is disposed between the films and that it forms vacant spaces holding gas, with the indents thereof, together with the films. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a laminate for a printing substrate having high resistance to ink used in a printing process and having excellent cushioning properties.

  Flexographic printing used for packaging materials such as cardboard, paper containers, paper bags, flexible packaging films, wallpaper materials, decorative materials such as decorative boards, and label printing has increased its specific gravity among various printing methods. The cushion layer used for this plays an important role in ensuring print quality. The cushion layer is used in the form of being sandwiched between the plate cylinder of the printing press and the flexographic printing plate.

  Conventionally, polyurethane and polyethylene have been used to form cushions. In addition, a foam material in which bubbles are contained in these materials is particularly often used. A cushion tape obtained by molding a foam material into a sheet is commercially available. Furthermore, an adhesive layer or a pressure-sensitive adhesive layer may be formed on both sides of the foam material formed into a sheet shape, and there are some that are easy to bond and fix to the plate cylinder of a printing press. As a material for the cushion layer, a thermosetting material is used, and there is a problem that a molding time is long due to the time required for the thermosetting.

On the other hand, Patent Document 1 discloses a method for producing a printing plate in which a thermally expandable capsule is mixed in a resin that is cured using an electron beam or X-ray, and is formed into a sheet shape. However, the method of curing using an electron beam or X-ray has a problem that the apparatus is complicated and expensive, and the penetration depth of the electron beam and X-ray into the resin is so shallow that it is difficult to sufficiently cure the thick film. was there.

  Patent Document 2 describes a cushion layer in which a thermally expandable capsule is mixed in a photosensitive resin and formed into a cylindrical shape, and a technique for forming the cushion layer in a short time using the photosensitive resin is disclosed. Has been.

  By the way, in the field of flexographic printing, there are many uses using a solvent ink, and a process of removing the ink adhering to the plate surface after the completion of printing using a solvent-based cleaning liquid may be performed. In the printing process using such solvent ink and the cleaning process using solvent-based cleaning liquid, the solvent soaks into the used cushion layer, the cushion layer swells, and the components of the cushion layer are extracted by the solvent, resulting in large mechanical properties. There is also a big problem of a decline, and there is a need for improvement. When the printing plate used for printing does not use a polyester film having a high dimensional stability and a high solvent barrier property as a support, that is, the photosensitive resin plate is bonded to the cushion layer directly or through an adhesive layer. In some cases, the influence of the solvent is great. This is presumably because the solvent component in the ink during printing penetrates the photosensitive resin and reaches the cushion layer or the adhesive layer.

  On the other hand, Patent Document 3 discloses a sheet-like support in which a photosensitive resin is patterned on a sheet-like support using a photoengraving technique, and a pencil-like or nail-like pattern is formed on the surface. It is disclosed to use. However, it has been pointed out that this structure cannot fully exhibit the performance as a cushion layer.

Thus, in the prior art, a cushion layer having high resistance to the solvent in the solvent ink used in the printing process and high characteristics as a cushion layer is desired.
Special table 2003-519036 gazette Japanese Patent Laid-Open No. 2004-255811 Japanese Patent Laid-Open No. 11-180065

  The problem to be solved by the present invention is to provide a laminate for a printing substrate having high resistance to ink used in the printing process and having excellent cushioning properties.

  Therefore, in view of the above circumstances, the present inventors have made extensive studies on the laminate for a printing substrate, and a sheet in which a concavo-convex pattern made of a cured resin is formed on at least one surface of the film. By using a cylindrical laminate for a printing substrate made of a laminate in which a plurality of layers are laminated in a cylindrical shape, a gap for holding gas is formed in the concave portion of the concave-convex pattern between the films, so that the cushioning characteristics are dramatically improved. In addition, the present inventors have found that solvent-resistant products are also improved, and the present invention has been completed.

That is, the present invention
[1] A cylindrical laminate for a printing substrate, comprising a sheet comprising a film and a cured resin projecting so as to form a concavo-convex pattern on at least one surface of the film,
A cylindrical shape for a printing substrate in which the resin cured product is disposed between the films, and the sheet is laminated in a plurality of layers in a cylindrical shape so as to define a void that holds gas together with the film in the concave portion. Laminate,
[2] The cylindrical laminate for a printing substrate according to [1], wherein the uneven pattern of the cured resin is regularly arranged on the film at a predetermined interval.
[3] The cylindrical laminate for a printing substrate according to [1] or [2], wherein the cured resin is a cured photosensitive resin formed by photocuring a photosensitive resin composition;
[4] As described in any one of [1] to [3] above, the Shore A hardness of the cured resin is 10 degrees or more and 80 degrees or less in a sample molded to a thickness of 2 mm. Cylindrical laminate for printing substrate
[5] The cylindrical shape for a printing substrate according to any one of [1] to [4], wherein the density of the laminate is 0.2 g / cm ³ or more and 0.8 g / cm ³ or less. Laminate,
[6] The resin cured product has at least one bond selected from a carbonate bond, an ester bond, and an ether bond, and / or at least one selected from an aliphatic saturated hydrocarbon chain and an aliphatic unsaturated hydrocarbon chain. The cylindrical laminate for a printing substrate according to any one of [1] to [5] above, which contains a compound having a molecular chain and a urethane bond,
[7] The cylindrical laminate for a printing substrate according to any one of [1] to [6], wherein the film is at least one film selected from polyethylene, polypropylene, and polyester,
[8] The volume of the concave portion present in one repeating unit of the concave-convex pattern made of a resin cured material regularly arranged on the film is 1 μm ³ or more and 8 × 10 ⁶ μm ³ or less [1] Or a cylindrical laminate for a printing substrate according to any one of [7],
[9] A method for producing a cylindrical laminate for a printing substrate, comprising a film and a sheet having a concavo-convex pattern made of a cured resin on the film on at least one surface,
Forming a photosensitive resin composition layer on the film;
Pressing the mold against the photosensitive resin composition layer so as to form a concavo-convex pattern on the photosensitive resin composition layer;
Irradiating light to the photosensitive resin composition layer on which the concavo-convex pattern is formed, forming a photosensitive resin cured product layer having a concavo-convex pattern; and
A step of laminating a sheet having the uneven pattern in a cylindrical shape;
A method for producing a cylindrical laminate for a printing substrate comprising:
[10] The manufacturing method according to [9], wherein the laminating step includes a step of bonding the convex portion to a surface of a film not having the concave / convex pattern.
[11] The manufacturing method according to [9] above, wherein the laminating step includes a step of bonding the convex portion to another convex portion of the concave-convex pattern of the film.
[12] The production method according to any one of [9] to [11], wherein the mold has a convex pattern on a surface of a roll,
[13] The production method according to [12], wherein the roll is an endless roll having no seam.
[14] The production method according to any one of [9] to [13], wherein the photosensitive resin composition layer is formed by applying a liquid photosensitive resin composition at 20 ° C. ,
[15] On the printing substrate cylindrical laminate according to any one of [1] to [8], a printing substrate capable of forming a pattern on the surface or a pattern on the surface A printing material obtained by laminating a printed printing substrate,
[16] The printing material according to [15], wherein the printing base material capable of forming a pattern on the surface includes a photosensitive resin composition layer or a cured photosensitive resin layer,
[17] A laser engraving method in which a pattern is formed on the surface of a printing substrate including a cured photosensitive resin layer, and a laser is irradiated to remove a resin in a portion irradiated with the laser to form a concave pattern The printing material according to [15] or [16] above,
I will provide a.

  ADVANTAGE OF THE INVENTION According to this invention, the tolerance for the ink used at a printing process is high, and the laminated body for printing base materials which has the outstanding cushioning property can be provided.

Hereinafter, preferred embodiments of the present invention will be described in detail.
In the cylindrical laminate for a printing substrate according to the present invention, a convex object made of a cured resin is disposed on at least one surface of the film, and the uneven pattern of the cured resin is formed on the surface. The sheet 10 is composed of a laminate in which a plurality of layers are laminated. In other words, the cylindrical laminate for a printing substrate according to the present invention has a concave / convex pattern of a cured resin product between the films constituting the laminate by interposing a cured resin product having a concave / convex pattern shape between the films. A void that can hold a gas is defined. By adopting such a configuration, the cylindrical laminate for a printing substrate according to the present invention has cushioning properties.

  FIG. 1 is a schematic cross-sectional view of a sheet in which a convex made of a cured resin is formed on at least one surface of a film. In FIG. 1, for convenience of explanation, a part of the cylindrical shape is taken out and displayed in a planar shape. On one surface 11 of the film 1, a convex body 2 made of a cured resin is formed.

  FIG. 2 shows a sheet 10 in which convex bodies made of a cured resin are disposed on one surface 11 of a film 1 according to an embodiment of the cylindrical laminate for a printing substrate according to the present invention. It is a schematic sectional drawing of an example of the laminated body formed by laminating | stacking on a layer. As in FIG. 1, FIG. 2 also shows a part of a cylindrical shape and displays it in a planar shape for convenience of explanation. As can be seen from FIG. 2, the cylindrical laminate for a printing substrate according to the present invention has the cured resin 2 disposed on one surface 11 of the film 1 and is disposed on the one surface 11 of the film. By adhering the cured resin 2 to the other surface 12 of the film 1 to be laminated in a cylindrical shape, a laminated body in which the sheet 10 is laminated in a plurality of layers is obtained. The film 1 shown in FIG. 2 is composed of a single film 1. Thus, the space | gap 3 is defined by interposing the convex-shaped object which consists of resin hardened | cured material at predetermined intervals between films. Due to the presence of such voids, excellent cushioning properties are imparted to the cylindrical laminate for a printing substrate according to the present invention.

  FIG. 3 shows a sheet 10 in which convex bodies made of a cured resin 2 are disposed on both surfaces 11 and 12 of a film 1 according to another embodiment of the cylindrical laminate for a printing substrate according to the present invention. It is a schematic sectional drawing of an example of the laminated body formed by laminating | stacking on two layers. As in FIG. 1 and FIG. 2, FIG. 3 also shows a part of the cylindrical shape and displays it in a planar shape for convenience of explanation. In FIG. 3, it is the laminated body which laminated | stacked the sheet | seat 10 so that the resin cured material 2 may be arrange | positioned on both surfaces of the sheet | seat 1 so that a concavo-convex pattern may be formed, and the resin cured products 2 may adhere | attach. As illustrated in FIG. 3, by adhering the top 5 of the cured resin 2 between the films, a void 3 that can hold a gas is defined. Due to the presence of such voids, excellent cushioning properties are imparted to the cylindrical laminate for a printing substrate according to the present invention. In addition, in FIG. 3, although the top part 5 of the resin cured material 2 is adhere | attached so that it may overlap completely, you may adhere | attach the resin cured material 2 so that a part of top part 5 may overlap.

  FIG. 4 shows a cylindrical shape for a printing substrate according to one embodiment of the present invention, which is formed by laminating four layers of a sheet 10 on which one surface of a film 1 is provided with a convex product made of a cured resin 2. The schematic sectional drawing of a laminated body is shown. Here, the relationship of the resin cured material 2 interposed between films is demonstrated. As illustrated in FIG. 2, the positional relationship between the cured resin products 2 sandwiched between the films 1 is not limited to the configuration illustrated in FIG. 2, but from the viewpoint of securing a cushion of the laminate. In the relationship between the resin cured product 2 existing above and the resin cured product 2 present immediately below, at least a part of the top 5 of the resin cured product 2 present below is the resin cured product 2 present above. It is preferable that the recessed part 4 of this is arrange | positioned on the surface opposite to this recessed part 4 through the film 1 arrange | positioned. Further, at least a part of the top portion 5 of the resin cured product 2 present below is arranged on the surface opposite to the convex portion through the film on which the convex portion of the resin cured product 2 existing above is disposed. It is preferable to be provided.

  The thickness of the film used in the cylindrical laminate for a printing substrate according to the present invention is usually 1 μm or more and 200 μm or less, preferably 10 μm or more and 100 μm or less, more preferably 10 μm or more and 50 μm or less. If the thickness of the film is in the above range, excellent cushion characteristics can be obtained without affecting the hardness of the film. The material of the film is preferably at least one film selected from the group consisting of polyethylene, polypropylene, and polyester. It may be a single material or a plurality of types of films.

  In the present invention, a concavo-convex pattern made of the cured resin 2 is formed on at least one surface of the film 1. The thickness of the convex part of the concavo-convex pattern is usually 1 μm or more and 200 μm or less, preferably 10 μm or more and 100 μm or less, more preferably 10 μm or more and 50 μm or less. If the thickness of the concavo-convex pattern formed on the film surface is in the above range, excellent cushion characteristics can be ensured.

  The uneven | corrugated pattern of the surface of the film used with the cylindrical laminated body for printing base materials based on this invention is comprised from resin cured material. Examples of the material for forming the cured resin include a thermosetting resin composition and a photosensitive resin composition, and the photosensitive resin composition is preferable from the viewpoint of curing speed. It is preferable to arrange regularly the uneven | corrugated pattern which consists of resin cured material on the film surface. When the uneven pattern is regularly arranged, the cushion characteristics of the laminate become uniform, and therefore, in a printed matter carried out using a printing substrate produced using the laminate, the fine halftone dot portion is also high. Print quality can be obtained.

  In this invention, it is preferable that the photosensitive resin composition used for formation of the laminated body which has cushioning properties contains resin (a) and an organic compound (b). The photosensitive resin composition used in the present invention may be solid or liquid at 20 ° C. In order to form a relatively thin film, it is preferable to use a photosensitive resin composition that is liquid at 20 ° C.

  The resin (a) has at least one bond selected from a carbonate bond, an ester bond, and an ether bond in the molecule, and / or at least selected from an aliphatic saturated hydrocarbon chain and an aliphatic unsaturated hydrocarbon chain. The inclusion of a compound having one kind of molecular chain and having a urethane bond is particularly preferable from the viewpoint of resistance to solvent ink used in the printing process. The resin (a) preferably has a polymerizable unsaturated group having a number average molecular weight of 1,000 to 500,000. A more preferable range of the number average molecular weight of the resin (a) is 2000 or more and 200,000 or less, and a more preferable range is 5000 or more and 100,000 or less. If the number average molecular weight of the resin (a) is 1000 or more, the cushion layer produced by crosslinking later maintains strength and can withstand repeated use. Moreover, if the number average molecular weight of resin (a) is 500,000 or less, it will become possible to apply | coat to the film surface, without the viscosity at the time of a shaping | molding process of the photosensitive resin composition rising excessively. The term “number average molecular weight” used in the present invention is a value measured by gel permeation chromatography, calibrated with polystyrene having a known molecular weight, and converted.

  The resin (a) preferably has a polymerizable unsaturated group particularly in the main chain, side chain or terminal of the molecular chain. The term “polymerizable unsaturated group” used in the present invention is a polymerizable unsaturated group involved in a radical or addition polymerization reaction. As a more preferable resin (a), a polymer having an average of 0.7 or more polymerizable unsaturated groups per molecule can be exemplified. When the average is 0.7 or more per molecule, the mechanical strength of the cushion layer obtained from the resin composition of the present invention is excellent. Furthermore, its durability is good and it can withstand repeated use, which is preferable. Considering the mechanical strength of the cured resin, the polymerizable unsaturated group of the resin (a) is preferably 0.7 or more per molecule, more preferably more than 1. In the resin (a), the position of the polymerizable unsaturated group is preferably directly bonded to the end of the polymer main chain, the end of the polymer side chain, the polymer main chain, or the side chain. The average number of polymerizable unsaturated groups contained in one molecule of the resin (a) can be obtained by a molecular structure analysis method using a nuclear magnetic resonance spectrum method (NMR method).

  As a method for producing the resin (a), for example, a direct introduction of a polymerizable unsaturated group may be used. However, as another method, a hydroxyl group, an amino group, an epoxy group, a carboxyl group, Can bind to the reactive groups of the above components having a molecular weight of about several thousand having a plurality of reactive groups such as acid anhydride groups, ketone groups, hydrazine residues, isocyanate groups, isothiocyanate groups, cyclic carbonate groups, and alkoxycarbonyl groups. A group that reacts with a terminal binding group after reacting with a binder having a plurality of groups (for example, polyisocyanate in the case of a hydroxyl group or an amino group), adjusting the molecular weight and converting to a terminal binding group And a method of introducing a polymerizable unsaturated group at the terminal by reacting with an organic compound having a polymerizable unsaturated group.

  Examples of the resin (a) include compounds having a polymerizable unsaturated group in the molecular main chain or side chain, such as polydienes such as polybutadiene and polyisoprene. In addition, a polymer compound in which a polymerizable unsaturated group is introduced into the molecule by a chemical reaction such as a substitution reaction, elimination reaction, condensation reaction, addition reaction, etc., starting from a polymer compound having no polymerizable unsaturation You can also. Examples of polymer compounds having no polymerizable unsaturated group include polyolefins such as polyethylene and polypropylene, polyhaloolefins such as polyvinyl chloride and polyvinylidene chloride, polystyrene, polyacrylonitrile, polyvinyl alcohol, polyvinyl acetate, polyvinyl acetal, In addition to C-C chain polymers such as polyacrylic acid, poly (meth) acrylic acid esters, poly (meth) acrylamide, and polyvinyl ether, polyethers such as polyphenylene ether, polythioethers such as polyphenylene thioether, Polyesters such as polyethylene terephthalate, polycarbonates, polyacetals, polyurethanes, polyamides, polyureas, polyimides, polydialkylsiloxanes and other polymer compounds, or these polymer compounds Polymer compounds having a hetero atom in the chain, a random copolymer synthesized from a plurality of kinds of monomer components include a block copolymer. Furthermore, it is possible to use a mixture of a plurality of polymer compounds having a polymerizable unsaturated group introduced in the molecule.

  In particular, the resin (a) is preferably a liquid resin having a glass transition temperature of 20 ° C. or lower, and more preferably a liquid resin having a glass transition temperature of 0 ° C. or lower from the viewpoint of moldability. Examples of such liquid resins include hydrocarbons such as polyethylene, polybutadiene, hydrogenated polybutadiene, polyisoprene, and hydrogenated poisoprene, polyesters such as adipate and polycaprolactone, and polymers such as polyethylene glycol, polypropylene glycol, and polytetramethylene glycol. Synthesized by using ethers, aliphatic polycarbonates, silicones such as polydimethylsiloxane, polymers of (meth) acrylic acid and / or derivatives thereof, and mixtures and copolymers thereof. Can be used. The content is preferably 30 wt% or more based on the entire resin (a). In particular, unsaturated polyurethanes having a polycarbonate structure are preferred from the viewpoint of weather resistance. Here, the term “liquid resin” used in the present invention means a polymer that has the property of being easily flow-deformed and solidified into a deformed shape by cooling, and when an external force is applied, It is a term corresponding to an elastomer that has the property of recovering its original shape in a short time when it is deformed instantaneously in response to an external force and the external force is removed. When the resin (a) is a liquid resin at 20 ° C., the photosensitive resin composition is also liquid at 20 ° C. The photosensitive resin composition of the present invention capable of obtaining good thickness accuracy and dimensional accuracy when molded into a sheet form preferably has a viscosity at 20 ° C. of 10 Pa · S to 10 kPa · S. More preferably, it is 50 Pa · S or more and 5 kPa · S or less. If the viscosity is 10 Pa · S or more, the mechanical strength of the produced laminate is sufficient and easy to process. If the viscosity is 10 kPa · S or less, it is easily deformed even at room temperature and easy to process. It is easy to mold on the film surface and the process is simple.

  The organic compound (b) used in the present invention is a compound having a polymerizable unsaturated group having a number average molecular weight of less than 1,000. The number average molecular weight is preferably 1000 or less because of easy dilution with the resin (a). The definition of a polymerizable unsaturated group is a polymerizable unsaturated group involved in a radical or addition polymerization reaction. Specific examples of the radical reactive compound in the organic compound (b) include olefins such as ethylene, propylene, styrene and divinylbenzene, acetylenes, (meth) acrylic acid and derivatives thereof, haloolefins, unsaturated nitriles such as acrylonitrile, etc. , (Meth) acrylamide and derivatives thereof, aryl compounds such as aryl alcohol and aryl isocyanate, unsaturated dicarboxylic acids such as maleic anhydride, maleic acid and fumaric acid and derivatives thereof, vinyl acetates, N-vinylpyrrolidone, N- Although vinyl carbazole etc. are mentioned, (meth) acrylic acid and its derivative are a preferable example from a viewpoint of the abundance of the kind, a price, the decomposability | degradability at the time of laser beam irradiation, etc. Examples of the compound (b) include alicyclic structures such as cycloalkyl, bicycloalkyl, cycloalkene and bicycloalkene, and compounds having an aromatic structure such as benzyl, phenyl, phenoxy and fluorene, alkyls and halogenated alkyls. , Compounds having structures such as alkoxyalkyl, hydroxyalkyl, aminoalkyl, tetrahydrofurfuryl, glycidyl, ester compounds with compounds such as alkylene glycol, polyoxyalkylene glycol, polyalkylene glycol and trimethylolpropane, polydimethylsiloxane, poly Examples thereof include compounds having a polysiloxane structure such as diethylsiloxane. Moreover, you may be a heteroaromatic compound containing elements, such as nitrogen and sulfur.

  The compound having an epoxy group that undergoes a ring-opening addition reaction in the organic compound (b) used in the present invention includes compounds obtained by reacting various polyols such as diols and triols with evichlorohydrin, and ethylene in the molecule. Examples thereof include an epoxy compound obtained by reacting a bond with a peracid. Specific examples of the compound having an epoxy group include ethylene glycol diglycidyl ether, jetylene glycol diglycidyl ether, triethylene glycol diglycidyl ether, tetraethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, triethylene glycol Propylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerin diglycidyl ether, glycerin triglycidyl ether, trimethylolpropane triglycidyl ether, bisphenol A diglycidyl Ether, hydrogenated bisphenol A diglycidyl ester Diglycidyl ether, polytetramethylene glycol diglycidyl ether, poly (propylene glycol adipate) diol diglycidyl ether, poly (ethylene glycol adipate) diol diglycidyl ether, poly (ethylene glycol) or bisphenol A added with ethylene oxide or propylene oxide (Caprolactone) Epoxy compounds such as diol diglycidyl ether and epoxy-modified silicone oil (trade name “HF-105” manufactured by Shin-Etsu Chemical Co., Ltd.) can be mentioned.

  In this invention, the organic compound (b) which has these polymerizable unsaturated groups can select the 1 type (s) or 2 or more types according to the objective. For example, when used as a cured resin constituting the cylindrical laminate for a printing substrate according to the present invention, as an organic compound used to suppress swelling against an organic solvent such as alcohol or ester as a solvent for printing ink, a long chain It is preferable to have at least one aliphatic, alicyclic or aromatic derivative. In order to increase the mechanical strength of the cured resin constituting the cylindrical laminate for a printing substrate according to the present invention, the organic compound (b) should have at least one alicyclic or aromatic derivative. In this case, it is preferably 20 wt% or more of the total amount of the organic compound (b), more preferably 50 wt% or more. The aromatic derivative may be an aromatic compound having an element such as nitrogen or sulfur.

  The photosensitive resin composition used in the present invention is crosslinked by irradiation with light or electron beam to develop physical properties as a cured resin, and a photopolymerization initiator (c) can be added at that time. The photopolymerization initiator (c) can be selected from those commonly used. For example, radical polymerization, cationic polymerization, and anion illustrated in “Polymer Data Handbook-Fundamental” edited by the Society of Polymer Science, published in 1986 by Fufukan. A polymerization initiator or the like can be used. Further, performing crosslinking by photopolymerization using a photopolymerization initiator is useful as a method for producing a resin cured product with high productivity while maintaining the storage stability of the photosensitive resin composition used in the present invention. A well-known initiator can also be used in that case. As the photopolymerization initiator (c) for inducing radical polymerization reaction, a hydrogen abstraction type photopolymerization initiator (d) and a decay type photopolymerization initiator (e) are used as particularly effective photopolymerization initiators.

  Although it does not specifically limit as a hydrogen abstraction type photoinitiator (d), It is preferable to use an aromatic ketone. Aromatic ketone is efficiently converted into an excited triplet state by photoexcitation, and a chemical reaction mechanism has been proposed in which this excited triplet state generates a radical by extracting hydrogen from the surrounding medium. The generated radical is considered to be involved in the photocrosslinking reaction. The hydrogen abstraction type photopolymerization initiator (d) used in the present invention may be any compound as long as it is a compound capable of generating hydrogen by extracting hydrogen from the surrounding medium through an excited triplet state. Examples of aromatic ketones include benzophenones, Michler ketones, xanthenes, thioxanthones, and anthraquinones, and it is preferable to use at least one compound selected from these groups. Benzophenones refer to benzophenone or derivatives thereof, and specifically include 3,3 ', 4,4'-benzophenone tetracarboxylic anhydride, 3,3', 4,4'-tetramethoxybenzophenone, and the like. Michler ketones refer to Michler ketones and derivatives thereof, xanthenes refers to derivatives substituted with xanthene and alkyl groups, phenyl groups, and halogen groups, and thioxanthones refers to thioxanthones, alkyl groups, phenyl groups, halogens. Derivatives substituted with a group include ethylthioxanthone, methylthioxanthone, chlorothioxanthone and the like. Anthraquinones are anthraquinone and derivatives substituted with an alkyl group, a phenyl group, a halogen group, or the like.

  The addition amount of the hydrogen abstraction type photopolymerization initiator (d) is preferably 0.1 wt% or more and 10 wt% or less, more preferably 0.5 wt% or more and 5 wt% or less of the total amount of the photosensitive resin composition. When the addition amount is within this range, when the liquid photosensitive resin composition is photocured in the air, the curability of the cured product surface can be sufficiently secured, and weather resistance can be secured.

  The decay type photopolymerization initiator (e) refers to a compound that generates an active radical by generating a cleavage reaction in the molecule after light absorption, and is not particularly limited. Specific examples include benzoin alkyl ethers, 2,2-dialkoxy-2-phenylacetophenones, acetophenones, acyloxime esters, azo compounds, organic sulfur compounds, diketones, and the like. It is preferable to use at least one compound selected from the group consisting of: Examples of the benzoin alkyl ethers include compounds described in benzoin isopropyl ether, benzoin isoptyl ether, and “photosensitive polymer” (Kodansha, 1977, page 228). Examples of 2,2-dialkoxy-2-phenylacetophenones include 2,2-dimethoxy-2-phenylacetophenone, 2,2-jetoxy-2-phenylacetophenone, and the like. Examples of acetophenones include acetophenone, trichloroacetophenone, 1-hydroxycyclohexyl phenylacetophenone, 2,2-jetoxyacetophenone, and the like. Examples of acyl oxime esters include 1-phenyl-1,2-propanedione-2- (o-benzoyl) oxime. Examples of the azo compound include azobisisoptyronitrile, diazonium compound, tetrazene compound and the like. Examples of organic sulfur compounds include aromatic thiols, mono- and disulfides, thiuram sulfides, dithiocarbamates, S-acyl dithiocarbamates, thiosulfonates, sulfoxides, sulfinates, dithiocarbonates, and the like. Examples of diketones include benzyl and methylbenzoyl formate.

  The addition amount of the collapsible photopolymerization initiator (e) is preferably 0.1 wt% or more and 10 wt% or less, more preferably 0.3 wt% or more and 3 wt% or less of the total amount of the photosensitive resin composition. If the addition amount is within this range, when the photosensitive resin composition is photocured in the air, the curability inside the cured product can be sufficiently secured.

（式中、Ｒ₁は、各々独立に、水素原子又は炭素数１〜１０のアルキル基を表す。また、Ｘは炭素数１〜１０のアルキレン基を表す。） A compound having a site functioning as a hydrogen abstraction type photopolymerization initiator and a site functioning as a decay type photopolymerization initiator in the same molecule can also be used as the photopolymerization initiator. There may be mentioned α-aminoacetophenones. Examples thereof include 2-methyl-1- (4-methylthiophenyl) -2-morpholino-propan-1-one and compounds represented by the following general formula (1).

(In the formula, each R ₁ independently represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. X represents an alkylene group having 1 to 10 carbon atoms.)

  The amount of the compound having a site functioning as a hydrogen abstraction type photopolymerization initiator and a site functioning as a decay type photopolymerization initiator in the same molecule is 0.1 wt% or more and 10 wt% of the total amount of the photosensitive resin composition. The following is preferable, and more preferably 0.3 wt% or more and 3 wt% or less. When the addition amount is within this range, the mechanical properties of the cured product can be sufficiently ensured even when the photosensitive resin composition is photocured in the atmosphere.

  A photopolymerization initiator that induces an addition polymerization reaction by absorbing light and generating an acid can also be used. For example, photocationic polymerization initiators such as aromatic diazonium salts, aromatic iodonium salts, and aromatic sulfonium salts, or polymerization initiators that absorb light and generate bases. The addition amount of these photopolymerization initiators is preferably in the range of 0.1 wt% to 10 wt% of the total amount of the photosensitive resin composition.

  The ratio of the resin (a) and the organic compound (b) in the photosensitive resin composition for forming the cured resin used in the present invention is 5 parts by weight with respect to 100 parts by weight of the resin (a). -200 weight part is preferable and the range of 20-100 weight part is more preferable. In addition, a polymerization inhibitor, an ultraviolet absorber, a dye, a pigment, a lubricant, a surfactant, a plasticizer, a fragrance, and the like can be added to the resin composition of the present invention according to the purpose and purpose.

  The manufacturing method of the cylindrical laminated body for printing base materials which concerns on this invention is a cylindrical laminated body for printing base materials containing the sheet | seat which has a film and the uneven | corrugated pattern which consists of resin hardened | cured material on the said film on at least one surface. A manufacturing method comprising: (1) a step of forming a photosensitive resin composition layer on the film; and (2) a photosensitive resin composition so as to form a concavo-convex pattern on the photosensitive resin composition layer. A step of pressing a mold on the layer, and (3) a step of irradiating the photosensitive resin composition layer on which the concave / convex pattern is formed to form a photosensitive resin cured product layer having the concave / convex pattern, (4) And a step of laminating the sheet having the uneven pattern in a cylindrical shape.

  As a method for forming the photosensitive resin composition used in the present invention on a film, an existing resin molding method can be used. For example, a casting method, a method of extruding a resin from a nozzle or a die with a machine such as a pump or an extruder, adjusting the thickness with a blade, and adjusting the thickness by calendering with a roll can be exemplified. In that case, it is also possible to perform the molding while heating within a range that does not deteriorate the performance of the resin. By performing physical and chemical treatments on the surface of the film used in the present invention, the adhesiveness with the photosensitive resin composition layer or the adhesive layer can be improved. Examples of the physical treatment method include a sand blast method, a wet blast method for injecting a liquid containing fine particles, a corona discharge treatment method, a plasma treatment method, an ultraviolet ray or vacuum ultraviolet ray irradiation method, and the like. The chemical treatment method includes a strong acid / strong alkali treatment method, an oxidant treatment method, a coupling agent treatment method, and the like.

  As a method of forming a concavo-convex pattern on a film using the photosensitive resin composition used in the present invention, a method of patterning through an exposure and development process using a photoengraving technique, a photosensitive resin composition on a film A method of forming a concave pattern by a laser engraving method on a cured photosensitive resin cured by irradiating light after coating, a mold with a roll having an uneven pattern on the surface after coating the photosensitive resin composition on a film A method of pressing and then irradiating and curing light, a method of applying a photosensitive resin composition on a film using a dispenser, and a method of photocuring thereafter, a resin composition dissolved in a solvent, and a dispenser on the film Examples of the method include applying the resin and then removing the solvent by drying. From the viewpoint of productivity, a method of photocuring after forming a concavo-convex pattern by embossing is preferable.

In this invention, it is preferable that the uneven | corrugated pattern which consists of resin cured material formed on a film is regularly arranged. As a dimension of the regularly arranged uneven pattern, it is preferable that the volume of the recesses present per repeating unit of the pattern is 1 μm ³ or more and 8 × 10 ⁶ μm ³ or less. A more preferable range is 1000 μm ³ or more and 8 × 10 ⁶ μm ³ or less, and further preferably 1000 μm ³ or more and 1 × 10 ⁶ μm ³ or less. If the volume of the concave portion existing per one repetition of the pattern is in the above range, the characteristics as the cushion layer can be sufficiently exhibited.

  Examples of the material of the roll having the concavo-convex pattern on the surface used in the method of forming the concavo-convex pattern by embossing include metals such as iron, aluminum and nickel, or organic materials such as rubber and plastic. Particularly in the case of organic materials, a method of forming a pattern by laser engraving is preferable. The surface of the roll having a concavo-convex pattern on the surface is preferably treated with a fluorine-based release agent or a silicone-based release agent. Moreover, after forming an uneven | corrugated pattern with the said roll, the photosensitive resin composition apply | coated on the film can be hardened by irradiating light. Alternatively, it can be cured by irradiating light while forming an uneven pattern with the roll.

  The cylindrical laminate for a printing substrate according to the present invention is formed by laminating a plurality of layers having a concavo-convex pattern made of a cured resin on the surface. When a plurality of layers are laminated using a film having a thickness of 100 μm or less, the formed laminate can also have a function as a support.

  The formed photosensitive resin composition layer is crosslinked by light irradiation to form a cured resin, specifically, a cured photosensitive resin layer. Further, it can be crosslinked by light irradiation while molding. Examples of the light source used for curing include a high pressure mercury lamp, an ultrahigh pressure mercury lamp, an ultraviolet fluorescent lamp, a germicidal lamp, a carbon arc lamp, a xenon lamp, and a metal halide lamp. The light applied to the photosensitive resin composition layer preferably has a wavelength of 200 nm to 300 nm. In particular, since many hydrogen abstraction type photopolymerization initiators have strong light absorption in this wavelength region, when having light with a wavelength of 200 nm to 300 nm, sufficient curability of the surface of the cured photosensitive resin layer is ensured. be able to. The light source used for curing may be one type, but the curability of the resin may be improved by curing using two or more types of light sources having different wavelengths, so two or more types of light sources may be used. There is no problem.

  The laminate for a printing substrate according to the present invention can be manufactured by cylindrically stacking the sheets made of the film having the cured photosensitive resin layer thus manufactured. This laminating process is roughly divided into two types. As a first method, the lamination step is performed such that the convex portion of the concave / convex pattern is adhered to the surface of the film not having the concave / convex pattern. In this case, since the cured photosensitive resin itself has adhesiveness, the sheets can be laminated in a cylindrical shape without requiring another adhesive layer. On the other hand, as a second method, the lamination step is performed such that the projections of the concavo-convex pattern are adhered to the other projections of the concavo-convex pattern of the film. This is a method of bonding the convex portions of the cured resin, but as described above, the cured photosensitive resin itself has adhesiveness, so that the sheet is cylindrical without requiring another adhesive layer. It can be laminated in a shape.

  The number of laminations in the cylindrical laminate for a printing substrate according to the present invention thus manufactured is not limited, but the hardness of the laminate tends to decrease as the number of laminations increases and the thickness of the laminate increases. It is in. The hardness of the laminate also varies depending on the uneven pattern or the material forming the film, and the shape and dimensions of the uneven pattern.

In addition, the number of times of lamination in the cylindrical laminate for a printing substrate according to the present invention thus manufactured is not limited, but the density of the laminate is 0.2 g / cm ³ or more and 0.9 g / cm ³ or less. Preferably, it is 0.2 g / cm ³ or more and 0.7 g / cm ³ or less, more preferably 0.3 g / cm ³ or more and 0.6 g / cm ³ or less. If it is said density range, the cushioning property of the laminated body concerning this invention can fully be ensured, and it is possible to ensure the mechanical strength of this laminated body. The density of the laminate according to the present invention is calculated from the volume and mass of the laminate. The method for measuring the volume is not particularly limited, but the method for calculating from the area and thickness of the laminate, or, when the laminate according to the present invention is cylindrical, measures the volume change of water even when immersed in water. Is required. At this time, it is preferable to seal the end face so that water does not enter the laminated body.

  Next, the usage form of the cylindrical laminated body for printing substrates which concerns on this invention is demonstrated. Specific examples of such use forms include, but are not limited to, a printing substrate on which a pattern can be formed on the surface as a printing plate or a printing substrate on which a pattern is formed on the surface of the present invention. It can utilize as a printing material comprised by laminating | stacking on the cylindrical laminated body for such printing base materials. The cylindrical laminate for a printing substrate according to the present invention has high resistance to ink used in the printing process and exhibits excellent cushioning properties. Therefore, the printing according to the present invention is performed between the printing press and the printing substrate. By interposing the cylindrical laminated body for the substrate, it is possible to ensure the printing quality using the printing substrate.

  The printing base material used for this invention will not be specifically limited if the photosensitive resin composition layer or the photosensitive resin hardened | cured material layer is included on the surface. The photosensitive resin composition layer for a printing substrate used in the present invention contains the above-mentioned resin (a), organic compound (b) and photoinitiator (c), and the photosensitive resin cured product layer has such a printing group. It contains a cured product layer obtained by crosslinking the photosensitive resin composition layer for materials by the action of light or radiation.

  Furthermore, the photosensitive resin composition layer for a printing substrate used in the present invention can contain an inorganic porous material (f).

  Here, the inorganic porous material (f) is an inorganic particle having fine pores or fine voids in the particle, and absorbs and removes viscous liquid residue generated in a large amount in laser engraving. And also has an anti-tacking effect on the printing plate surface. The inorganic porous material (f) used in the present invention is added for the purpose of removing viscous liquid residue, and has a number average particle diameter, specific surface area, average pore diameter, pore volume, and loss on ignition. The performance is greatly affected.

  The inorganic porous material (f) used in the present invention preferably has a number average particle size of 0.1 to 100 μm. A more preferable range of the average particle diameter is 0.5 to 20 μm, and a further preferable range is 3 to 10 μm. The average particle size of the porous inorganic absorbent used in the present invention is a value measured using a laser scattering type particle size distribution measuring device.

The range of the specific surface area of the inorganic porous material (f) used in the present invention is preferably 10 m ² / g or more and 1500 m ² / g or less. A more preferable range is 100 m ² / g or more and 800 m ² / g or less. When the specific surface area of 10 m ² / g or more, removal of liquid debris during laser engraving becomes sufficiently and, if less 1500 m ² / g, suppressing the increase in viscosity of the printing substrate for a photosensitive resin composition, Moreover, thixotropy can be suppressed. The specific surface area of the inorganic porous material (f) used in the present invention is determined from the nitrogen adsorption isotherm at −196 ° C. based on the BET equation.

  The average pore diameter of the inorganic porous material (f) used in the present invention has an extremely large influence on the amount of liquid residue absorbed during laser engraving. A preferable range of the average pore diameter is 1 nm to 1000 nm, more preferably 2 nm to 200 nm, and further preferably 2 nm to 50 nm.

  The average pore diameter of the inorganic porous material (f) used in the present invention is a value measured using a nitrogen adsorption method. Those having an average pore diameter of 2 to 50 nm are particularly called mesopores, and the ability of porous particles having mesopores to absorb liquid waste is extremely high. The pore size distribution of the inorganic porous material (f) used in the present invention is determined from the nitrogen adsorption isotherm at -196 ° C. The pore volume of the inorganic porous material (f) used in the present invention is preferably from 0.1 ml / g to 10 ml / g, more preferably from 0.2 ml / g to 5 ml / g. When the pore volume is 0.1 ml / g or more, the amount of viscous liquid residue absorbed is sufficient, and when the pore volume is 10 ml / g or less, the mechanical strength of the particles can be ensured. In the present invention, a nitrogen adsorption method is used to measure the pore volume. The pore volume of the inorganic porous material (f) used in the present invention is determined from an adsorption isotherm of nitrogen at −196 ° C. In the present invention, there is an oil absorption amount as an index for evaluating the liquid residue adsorption amount. This is defined by the amount of oil absorbed by 100 g of the inorganic porous body. A preferred range of the oil absorption of the inorganic porous material (f) used in the present invention is 10 ml / 100 g or more and 2000 ml / 100 g or less, and a more preferred range is 50 ml / 100 g or more and 1000 ml / 100 g or less. If the oil absorption is 10 ml / 100 g or more, removal of the liquid residue generated during laser engraving is sufficient, and if it is 2000 ml / 100 g or less, the mechanical strength of the inorganic porous body can be sufficiently secured. The oil absorption was measured according to JIS-K5101.

  The inorganic porous material (f) used in the present invention preferably retains its porosity without being deformed or melted by laser light irradiation in the infrared wavelength region. The loss on ignition when treated at 950 ° C. for 2 hours is preferably 15 wt% or less, more preferably 10 wt% or less.

  The particle shape of the inorganic porous material of the present invention is not particularly limited, and spherical, flat, needle-like, amorphous, or particles having protrusions on the surface can be used. In particular, spherical particles are preferable from the viewpoint of wear resistance. It is also possible to use particles having hollow inside particles, spherical granules having a uniform pore diameter such as silica sponge, and the like. Although not particularly limited, for example, porous silica, mesoporous silica, silica-zirconia porous gel, porous alumina, porous glass and the like can be mentioned. Moreover, since the pore diameter cannot be defined for a layer having a gap of several to 100 nm such as a layered clay compound, in the present invention, the gap between the layers is defined as the pore diameter.

  In the present invention, these inorganic porous bodies (f) can be selected from one type or two or more types, and by adding the inorganic porous body (f), generation of liquid debris during laser engraving and relief Improvements such as tack prevention of the printing plate are effectively performed.

  The ratio of the resin (a), the organic compound (b), and the inorganic porous body (f) in the photosensitive resin composition for a printing substrate used in the present invention is usually 100 parts by weight of the resin (a). The organic compound (b) is preferably 5 to 200 parts by weight, and more preferably 20 to 100 parts by weight. The inorganic porous body (f) is preferably 1 to 100 parts by weight, more preferably 2 to 50 parts by weight, and still more preferably 2 to 20 parts by weight.

  A polymerization inhibitor, ultraviolet absorber, dye, pigment, lubricant, surfactant, plasticizer, fragrance, etc. may be added to the photosensitive resin composition for a printing substrate used in the present invention according to the purpose and purpose. it can.

  An existing resin molding method can be used as the method for molding the photosensitive resin composition for a printing substrate used in the present invention into a sheet shape or a cylindrical shape. For example, a casting method, a method of extruding a resin from a nozzle or a die with a machine such as a pump or an extruder, adjusting the thickness with a blade, and adjusting the thickness by calendering with a roll can be exemplified. In that case, it is also possible to perform the molding while heating within a range that does not deteriorate the performance of the resin. Moreover, you may perform a rolling process, a grinding process, etc. as needed. Usually, it is often formed on a sheet-like support made of a material such as PET or nickel, but it may be formed directly on a cylinder of a printing machine. Further, a cylindrical support made of fiber reinforced plastic (FRP), plastic, or metal can also be used. The cylindrical support can be hollow with a constant thickness for weight reduction. The role of the sheet-like support or the cylindrical support is to ensure the dimensional stability of the printing original plate. Therefore, it is necessary to select one having high dimensional stability. When evaluated using a linear thermal expansion coefficient, the upper limit value of a preferable material is 100 ppm / ° C. or less, more preferably 70 ppm / ° C. or less. Specific examples of materials include polyester resin, polyimide resin, polyamide resin, polyamideimide resin, polyetherimide resin, polybismaleimide resin, polysulfone resin, polycarbonate resin, polyphenylene ether resin, polyphenylene thioether resin, polyethersulfone resin, all Examples thereof include liquid crystal resins composed of aromatic polyester resins, wholly aromatic polyamide resins, and epoxy resins. Further, these resins can be laminated and used. Moreover, a porous sheet, for example, a cloth formed by knitting fibers, a nonwoven fabric, a film in which pores are formed, or the like can be used as the sheet-like support. When a porous sheet is used as the sheet-like support, the photosensitive resin cured product layer for the printing substrate and the sheet-like support are obtained by photo-curing after impregnating the photosensitive resin composition for the printing substrate with holes. High integration can be obtained. The fibers forming the cloth or nonwoven fabric include glass fibers, alumina fibers, carbon fibers, alumina / silica fibers, boron fibers, high silicon fibers, potassium titanate fibers, inorganic fibers such as sapphire fibers, natural materials such as cotton and hemp Examples thereof include semi-synthetic fibers such as fibers, rayon and acetate, and synthetic fibers such as nylon, polyester, acrylic, vinylon, polyvinyl chloride, polyolefin, polyurethane, polyimide, and aramid. Further, cellulose produced by bacteria is a highly crystalline nanofiber, and is a material capable of producing a thin nonwoven fabric with high dimensional stability.

  Examples of a method for reducing the linear thermal expansion coefficient of the support include a method of adding a filler, a method of impregnating or coating a resin on a mesh cloth such as wholly aromatic polyamide, a glass cloth, or the like. As the filler, generally used organic fine particles, inorganic fine particles such as metal oxide or metal, organic / inorganic composite fine particles, and the like can be used. In addition, porous fine particles, fine particles having cavities inside, microcapsule particles, and layered compound particles in which a low molecular compound intercalates can be used. In particular, metal oxide fine particles such as alumina, silica, titanium oxide, and zeolite, latex fine particles made of polystyrene / polybutadiene copolymer, natural product-based organic fine particles such as highly crystalline cellulose, and the like are useful.

  By performing physical and chemical treatments on the surface of the sheet-like support or cylindrical support used in the present invention, the adhesion with the photosensitive resin composition layer for a printing substrate can be improved. Examples of the physical treatment method include a sand blast method, a wet blast method for injecting a liquid containing fine particles, a corona discharge treatment method, a plasma treatment method, an ultraviolet ray or vacuum ultraviolet ray irradiation method, and the like. The chemical treatment method includes a strong acid / strong alkali treatment method, an oxidant treatment method, a coupling agent treatment method, and the like.

  The formed photosensitive resin composition layer for a printing substrate is crosslinked by light irradiation to form a printing original plate. Further, it can be crosslinked by light irradiation while molding. Examples of the light source used for curing include a high pressure mercury lamp, an ultrahigh pressure mercury lamp, an ultraviolet fluorescent lamp, a germicidal lamp, a carbon arc lamp, a xenon lamp, and a metal halide lamp. The light applied to the photosensitive resin composition layer for a printing substrate preferably has light having a wavelength of 200 nm to 300 nm. In particular, since many hydrogen abstraction type photopolymerization initiators have strong light absorption in this wavelength region, when having light with a wavelength of 200 nm to 300 nm, the curability of the surface of the cured photosensitive resin layer for a printing substrate is required. Can be secured sufficiently. The light source used for curing may be one type, but the curability of the resin may be improved by curing using two or more types of light sources having different wavelengths, so two or more types of light sources may be used. There is no problem.

  The thickness of the original plate used for laser engraving may be arbitrarily set according to the purpose of use, but is generally in the range of 0.1 to 7 mm when used as a printing plate. In some cases, a plurality of materials having different compositions may be stacked. For example, a layer that can be engraved using a laser having an oscillation wavelength in the near infrared region such as a YAG laser, a fiber laser, or a semiconductor laser is formed on the outermost surface, and an infrared laser such as a carbon dioxide laser or the like is formed under the layer. It is also possible to form a layer capable of laser engraving using a visible / ultraviolet laser. By forming such a laminated structure, a relatively high-power carbon dioxide laser is used to deeply engrave a relatively rough pattern, and a very fine pattern near the surface is used using a near-infrared laser such as a YAG laser or fiber laser. Can be engraved. Since an extremely fine pattern may be engraved relatively shallowly, the thickness of the layer sensitive to the near infrared laser is preferably in the range of 0.01 mm to 0.5 mm. Thus, by laminating a layer sensitive to the near infrared laser and a layer sensitive to the infrared laser, the depth of the pattern engraved using the near infrared laser can be accurately controlled. This is because a layer that is sensitive to an infrared laser utilizes a phenomenon that is difficult to engrave with a near infrared laser. The difference in the fineness of the engraving pattern is caused by the difference in the oscillation wavelength unique to the laser device, that is, the difference in the diameter of the laser beam that can be narrowed. When laser engraving is performed in this way, engraving can be performed using separate laser engraving equipment equipped with infrared laser and near infrared laser, and laser engraving equipment equipped with both infrared laser and near infrared laser can be used. It is also possible to use.

  In laser engraving, a relief image is created on an original by operating a laser device using a computer as an image to be formed as digital data. Any laser may be used for the laser engraving as long as the original plate includes a wavelength having absorption, but in order to perform engraving at a high speed, a laser with a high output is desirable. Infrared or infrared emitting solid lasers such as YAG lasers and semiconductor lasers are preferred. In addition, the second harmonic of a YAG laser having an oscillation wavelength in the visible light region, a copper vapor laser, an ultraviolet laser having an oscillation wavelength in the ultraviolet region, such as an excimer laser, and a YAG laser wavelength-converted to the third or fourth harmonic are It can be ablated by cutting the bonds of organic molecules and is suitable for fine processing. The laser may be continuous irradiation or pulse irradiation. In general, resin has absorption in the vicinity of 10 μm of carbon dioxide laser, so it is not essential to add a component that helps the absorption of laser light, but YAG laser has a wavelength in the vicinity of 1.06 μm. There is not much that has. In that case, it is preferable to add a dye or a pigment, which is a component that assists in the absorption thereof. Examples of such dyes include: poly (substituted) phthalocyanine compounds and metal-containing phthalocyanine compounds; cyanine compounds; squarylium dyes; chalcogenopyrylarylidene dyes; chloronium dyes; metal thiolate dyes; bis (chalcogenopyrrillo) polymethine dyes; Indolizine dyes; bis (aminoaryl) polymethine dyes; merocyanine dyes; and quinoid dyes. Examples of pigments include carbon black, graphite, copper chromite, chromium oxide, cobalt chrome aluminate, dark inorganic pigments such as copper oxide and iron oxide, and metal powders such as iron, aluminum, copper and zinc, and these metals And those doped with Si, Mg, P, Co, Ni, Y or the like. These dyes and pigments may be used alone, in combination of a plurality, or in any form such as a multilayer structure. However, in the case of a system in which the photosensitive resin composition for a printing substrate is cured using light, the addition amount of an organic / inorganic compound having a large light absorption at the wavelength of light used for curing does not affect the photocurability. The addition ratio with respect to the total amount of the photosensitive resin composition for a printing substrate is preferably 5 wt% or less, more preferably 2 wt% or less.

  Laser engraving is carried out in an oxygen-containing gas, generally in the presence of air or an air stream, but can also be carried out in the presence of carbon dioxide or nitrogen gas. After engraving is finished, the powdery or liquid substance slightly generated on the relief printing plate surface is washed with an appropriate method such as water containing a solvent or a surfactant, or a water-based cleaning agent is irradiated by a high-pressure spray or the like. Alternatively, it may be removed using a method of irradiating high-pressure steam.

  In the present invention, after engraving to form a concave pattern by irradiating a laser beam, following the step of removing powdery or viscous liquid residue remaining on the plate surface, the surface of the printing plate on which the pattern is formed has a wavelength of 200 nm to 450 nm. Post-exposure can be performed by irradiating light. This is an effective method for removing tack on the surface. The post-exposure may be performed in any environment such as air, inert gas atmosphere, and water. This is particularly effective when a hydrogen abstraction type photopolymerization initiator is contained in the photosensitive resin composition for a printing substrate used in the present invention. Furthermore, before the post-exposure step, the printing plate surface may be exposed to a treatment liquid containing a hydrogen abstraction type photopolymerization initiator. Moreover, you may expose in the state which immersed the printing plate in the process liquid containing a hydrogen abstraction type photoinitiator.

  EXAMPLES Hereinafter, although this invention is demonstrated based on an Example, this invention is not restrict | limited by these.

(Production Example 1)
To a 1 L separable flask equipped with a thermometer, a stirrer, and a reflux condenser, 447.24 g of the trademark “PCDL L4672” (number average molecular weight 1990, OH value 56.4), which is a polycarbonate diol manufactured by Asahi Kasei Co., Ltd., and tolylene diisocyanate. After adding 30.83 g of natto and reacting at 80 ° C. for about 3 hours, 14.83 g of 2-methacryloyloxyisocyanate was added and further reacted for about 3 hours, and the terminal was a methacrylic group (within the molecule). A resin (A) having a number average molecular weight of about 10,000 having an average of about 2 polymerizable unsaturated groups per molecule) was produced. This resin was in the shape of a syrup at 20 ° C., flowed when an external force was applied, and did not recover its original shape even when the external force was removed.

Example 1
As resin (a), 100 parts by weight of resin (a) synthesized in Production Example 1, 25 parts by weight of phenoxyethyl methacrylate and 19 parts by weight of polypropylene glycol monomethacrylate as organic compound (b), 2, A photosensitive resin composition was prepared by mixing 0.9 parts by weight of 2-dimethoxy-2-phenylacetophenone.
The prepared photosensitive resin composition was applied at a thickness of 25 μm onto a 15 μm thick polyethylene terephthalate (PET) film whose surface was subjected to an easy adhesion treatment. By embossing a photosensitive metal composition layer coated on the PET film with a metal cylindrical mold in which convex portions of a small square pyramid are regularly arranged on the surface, the photosensitive resin composition layer Fine concave portions were formed, and further irradiated with light from a metal halide lamp (manufactured by Fusion, USA) from the PET film side to obtain a cured photosensitive resin having fine concave portions. The cured photosensitive resin could be easily peeled off from the surface of the metal cylindrical surface treated with a fluorine-based release agent. The dimensions of the convex portions of the fine pyramidal frustum present on the surface of the metal cylinder were such that the top surface of the quadrangular pyramid was a square with a side of 40 μm, the bottom side was a square with a thickness of 60 μm, and the height was 100 μm. Further, the convex pattern of the truncated pyramid was regularly arranged on the entire surface of the metal cylindrical shape with a pitch of 80 μm. The thickness of the cured photosensitive resin to which the pattern of the mold was transferred was about 50 μm, and a concave pattern in which square pyramids were arranged in reverse was formed. The bottom surface of the recess was a square with a side of 40 μm, and the opening was a square with a side of about 50 μm. It was a three-dimensional pattern in which such minute recesses were regularly arranged with a pitch of 80 μm. From the dimensions of the obtained concave pattern, the volume of the concave portion of one repeating unit is about 9 × 10 ⁴ μm ³ , and a hollow cylinder formed by laminating 10 layers of laminated photosensitive resin cured products having a concave pattern The density of the laminate was about 0.5 g / cm ³ .

  The photosensitive resin composition is uniformly applied at a thickness of about 10 μm on the surface of an air cylinder whose surface has been treated with a fluorine-based mold release agent, and the sheet formed as described above is coated on the PET film side. A hollow cylindrical laminate was formed by wrapping around the surface of the air cylinder 10 times so as to be on the lower surface.

  Further, the photosensitive resin composition described above was applied to the surface of the formed hollow cylindrical laminate for printing substrate with a thickness of about 1.9 mm, and the surface was coated with a PET cover film with a thickness of about 10 μm. Then, the light of the said metal halide lamp was irradiated and the photosensitive resin composition was photocured. After peeling off the PET cover film, the surface was ground and polished until the thickness of the cured photosensitive resin was 1.7 mm, and a hollow cylindrical printing original plate capable of laser engraving was prepared.

  A relief pattern was formed on the surface of the obtained hollow cylindrical printing original plate using a laser engraving method, and then mounted on an air cylinder to be used for flexographic printing. In the obtained printed matter, a halftone dot pattern and a fine character pattern were clearly printed.

  The photosensitive resin composition is applied in a sheet form on a PET film with a thickness of 2 mm, the surface is covered with a PET cover film, and then cured with the light of the metal halide lamp to form a sheet-shaped photosensitive resin cured product layer. Got. It was 71 degree | times when the Shore A hardness of the obtained photosensitive resin hardened | cured material layer was measured.

(Comparative Example 1)
Using a double-sided adhesive tape on the metal cylinder of the flexographic printing machine so that the PET film side is the outside, the sheet on which the concave pattern made of the photosensitive resin cured product is formed on one side of the film as in Example 1. One layer was wound and fixed. On top of that, the photosensitive resin composition used in Example 1 for a printing substrate was applied to a thickness of 1.9 mm, and a cured photosensitive resin was obtained in the same manner as in Example 1. A relief pattern was formed on the surface of the obtained photosensitive resin cured product using a laser engraving method, and then printing was performed using a flexographic printer. The obtained printed matter had unclear portions in the halftone dot pattern. In addition, in the solid portion, a portion where the ink was faint was confirmed. It is presumed that the sheet for one layer formed on the cylinder surface did not function sufficiently as a cushion layer.

  According to the present invention, a laminate suitable for a laser engraving printing substrate suitable for a flexographic printing plate, a dry offset printing plate, a letter press printing plate, and a blanket for offset printing is provided, and has high resistance to ink used in the printing process. , Has excellent cushioning properties.

FIG. 1 is a schematic cross-sectional view of a sheet in which a convex made of a cured resin is formed on at least one surface of a film. FIG. 2 is a schematic view of a laminated laminate for a printing substrate according to an embodiment of the present invention, in which a sheet in which a convex product made of a cured resin is disposed on one surface of a film is laminated in two layers. It is a schematic sectional drawing of an example of the laminated body formed in this way. FIG. 3 is a schematic view of a laminate in which convex bodies made of a cured resin are disposed on both sides of a film according to another embodiment of the cylindrical laminate for a printing substrate according to the present invention. It is a schematic sectional drawing of an example of the formed laminated body. FIG. 4 shows a cylindrical laminated body for a printing substrate according to one embodiment of the present invention, which is formed by laminating four sheets of a sheet on which a convex object made of a cured resin is disposed on one surface of a film. A schematic sectional view is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1; Film, 2; Resin hardened | cured material, 3; Space | gap, 4; Concave part, 5; Top part, 10; Sheet, 11: One surface, 12;

Claims (17)

A cylindrical laminate for a printing substrate comprising a sheet comprising a film and a resin cured product protruding so as to form a concavo-convex pattern on at least one surface of the film,
A cylindrical shape for a printing substrate in which the resin cured product is disposed between the films, and the sheet is laminated in a plurality of layers in a cylindrical shape so as to define a void that holds gas together with the film in the concave portion. Laminated body.   The cylindrical laminate for a printing substrate according to claim 1, wherein the uneven pattern of the cured resin is regularly arranged on the film at a predetermined interval.   The cylindrical laminate for a printing substrate according to claim 1 or 2, wherein the cured resin is a cured photosensitive resin formed by photocuring a photosensitive resin composition.   The cylinder for a printing substrate according to any one of claims 1 to 3, wherein the Shore A hardness of the cured resin is 10 degrees or more and 80 degrees or less in a sample molded to a thickness of 2 mm. Laminate. The cylindrical laminate for a printing substrate according to any one of claims 1 to 4, wherein the density of the laminate is 0.2 g / cm ³ or more and 0.8 g / cm ³ or less.   The cured resin has at least one kind of bond selected from a carbonate bond, an ester bond, and an ether bond, and / or at least one kind of molecule selected from an aliphatic saturated hydrocarbon chain and an aliphatic unsaturated hydrocarbon chain. The cylindrical laminate for a printing substrate according to any one of claims 1 to 5, comprising a compound having a chain and having a urethane bond.   The cylindrical laminate for a printing substrate according to any one of claims 1 to 6, wherein the film is at least one film selected from polyethylene, polypropylene, and polyester. Onto the film, the volume of the recesses present in the 1 repeat unit of the uneven pattern composed of a cured resin which is disposed regularly is at 1 [mu] m ³ or more 8 × 10 ⁶ μm ³ or less, of the claims 1 to 7 The cylindrical laminated body for printing base materials as described in any one. A method for producing a cylindrical laminate for a printing substrate comprising a film and a sheet having a concavo-convex pattern made of a resin cured product on at least one surface on the film,
Forming a photosensitive resin composition layer on the film;
Pressing the mold against the photosensitive resin composition layer so as to form a concavo-convex pattern on the photosensitive resin composition layer;
Irradiating light to the photosensitive resin composition layer on which the concavo-convex pattern is formed, forming a photosensitive resin cured product layer having a concavo-convex pattern; and
A step of laminating a sheet having the uneven pattern in a cylindrical shape;
The manufacturing method of the cylindrical laminated body for printing base materials containing this.   The said lamination process is a manufacturing method of Claim 9 including the process of adhere | attaching the said convex part on the surface of the film which does not have the said uneven | corrugated pattern.   The said lamination process is a manufacturing method of Claim 9 including the process of adhere | attaching the said convex part on the other convex part of the uneven | corrugated pattern of the said film.   The manufacturing method according to claim 9, wherein the mold has a convex pattern on a surface of a roll.   The manufacturing method of Claim 12 which is an endless roll in which the seam does not exist in the said roll.   The manufacturing method as described in any one of Claim 9 thru | or 13 in which the said photosensitive resin composition layer is formed by apply | coating a liquid photosensitive resin composition at 20 degreeC.   A printing substrate on which a pattern can be formed on a surface or a printing substrate on which a pattern is formed on the cylindrical laminate for a printing substrate according to any one of claims 1 to 8. Printing material obtained by laminating.   The printing material according to claim 15, wherein the printing base material capable of forming a pattern on the surface includes a photosensitive resin composition layer or a photosensitive resin cured product layer. The method of forming a pattern on the surface of the printing substrate including the photosensitive resin cured product layer is a laser engraving method in which a resin is removed by irradiating a laser to form a concave pattern. The printing material according to claim 15 or 16.

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