JP2009204856A - Method for preparing flexographic printing plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for preparing a flexographic printing plate with less environmental load in a shortened plate making time. <P>SOLUTION: The method for preparing a flexographic printing plate includes: a step (step (i)) of exposing a photosensitive resin element including a photosensitive resin layer (A), an adhesive strength adjusting layer (B) adjacent to the layer (A), and an adjacent layer (C) adjacent to the layer (B) to cure part of the layer (A), or a step (step (ii)) where a photosensitive resin layer (A) is exposed to cure part of the layer (A), an adhesive strength adjusting layer (B) and an adjacent layer (C) adjacent to the layer (B) are laid in such a way that the layer (B) comes in contact with the layer (A) to form a photosensitive resin element, and the photosensitive resin element is exposed; and a step (step (iii)) of removing at least part of an uncured portion of the layer (A) by exfoliating unexposed portions of the layer (B) and the layer (C) after the step (i) or (ii). A printing plate obtained by the method is also provided. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for producing a flexographic printing plate and a printing plate obtained thereby.

Constituents for flexographic printing plates have a polyester film or the like as a support, a photosensitive resin composition on the support, and further smooth contact with a negative film on the photosensitive resin composition as necessary. For this purpose, a protective layer or an ultraviolet shielding layer containing an infrared sensitive material that can be removed by an infrared laser is provided.
A general method for making a flexographic printing plate from such a photosensitive resin composition for a flexographic printing plate is to first expose the entire surface of the structure through a support (ultraviolet exposure) (back exposure), and then photopolymerize the resin composition. The process of forming a thin and uniform cured layer, then the process of image exposure (relief exposure) on the photosensitive resin layer via a negative film or directly from the top of the UV shielding layer, removing the unexposed part (uncured part) Thus, it is manufactured through a step of imparting irregularities, a step of post-processing exposure to the surface of the resin structure on which irregularities are formed, if necessary.

As a method of removing the unexposed portion, a method of washing away with a developing solution, or an unexposed portion heated to 40 ° C. to 200 ° C. as described in Patent Document 1 is brought into contact with an absorbent layer such as a nonwoven fabric. A method for removing an unexposed portion by removing an absorbing layer is known. On the other hand, for lithographic printing, Patent Document 2 discloses a photosensitive printing plate developed by a peel-apart method, in which a styrene / maleic anhydride copolymer is listed as a binder used in the photosensitive layer. Furthermore, Patent Document 3 proposes a material in which the photopolymerizable layer using a binder such as chlorinated natural rubber changes the adhesiveness with a hydrophilic layer or a cover film by exposure.
Japanese Patent Laid-Open No. 5-19469 JP 7-175207 A JP 7-325394 A

However, in the photosensitive resin composition for flexographic printing plates, the environmental load is sufficiently suppressed, and the peel development without using a developing solution has not yet been known to have sufficiently achieved adhesion adjusting power. Is the actual situation.
The method using a developer and the method described in Patent Document 1 are not preferable from the viewpoint of environmental load because the use of an absorption layer generates waste and contaminated wastewater by-products. In addition, when a large amount of developer or absorbent layer containing a photosensitive resin in an unexposed part is disposed of, the cost is expensive, and in the case of processing with a developer, plate-making time is required because long drying is required. From the viewpoint of taking The technique disclosed in Patent Document 2 relates to a lithographic plate, and the photosensitive layer has low elasticity and is not suitable as a flexographic printing material. Also, the disclosed adhesive layer and the photosensitive layer suitable as a flexographic printing material are disclosed. The adhesive strength is low, and it is difficult to remove the uncured portion of the photosensitive layer. Furthermore, since the coating weight is small, it is not suitable for a flexographic printing plate because it prints up to portions other than the printed image area, and even if the coating weight is increased, it is preferable because the peeling force during peeling development becomes great. Absent. The technique disclosed in Patent Document 3 is not preferable because the adhesive force between the coating layer for increasing the adhesion and the photosensitive material is low and it is difficult to remove the uncured portion of the photosensitive layer. Furthermore, since the coating weight is small, it is not suitable for a flexographic printing plate because it prints up to portions other than the printed image area, and even if the coating weight is increased, it is preferable because the peeling force during peeling development becomes great. Absent.
The present invention is a method for producing a flexographic printing plate excellent in suitability as a flexographic printing plate, which is preferable from the viewpoint of environmental load because the generation amount of waste and contaminated wastewater by-products is small, and is low in cost and shortened in plate making time It is another object of the present invention to provide a flexographic printing plate photosensitive resin composition for peeling development.

As a result of intensive studies to solve the above problems, the present inventors have found that the above problems can be solved by a manufacturing method using the photosensitive resin composition including an adhesive force adjusting layer, and completed the present invention. It came to do.
That is, the present invention is as follows.
1. The photosensitive resin structure including the photosensitive resin layer (A), the adhesion adjusting layer (B) adjacent to the layer (A), and the adjacent layer (C) adjacent to the layer (B) is exposed, and the layer ( A step of curing a part of A) (step (i)), or after exposing the photosensitive resin layer (A) to cure a part of the layer (A), the adhesion adjusting layer (B) and the layer The adjacent layer (C) adjacent to (B) is laminated so that the layer (B) is in contact with the layer (A) to form a photosensitive resin structure, and then the photosensitive resin structure is exposed (process) (Ii))
After the step (i) or (ii), the unexposed portion of the layer (C) and the layer (B) is peeled to remove at least a part of the uncured portion of the layer (A) (step (step ( iii))
The manufacturing method of the flexographic printing plate containing these.
2. 1. The photosensitive resin layer (A) contains a thermoplastic elastomer (a), a photopolymerizable monomer (b), and a photopolymerization initiator (c). Manufacturing method.
3. 2. The thermoplastic elastomer (a) comprising a block copolymer comprising a polymer block mainly comprising a conjugated diene and a polymer block mainly comprising a vinyl aromatic hydrocarbon. Manufacturing method.
4). 1. The adhesive strength adjusting layer (B) contains an elastomeric adhesive (B1). ~ 3. Either manufacturing method.
5. 1. The adhesive strength adjusting layer (B) contains an elastomeric adhesive (B1), a photopolymerizable monomer, and a photopolymerization initiator. ~ 3. Either manufacturing method.
6). The elastomeric adhesive (B1) contains a block copolymer containing a polymer block mainly composed of conjugated diene and a polymer block mainly composed of vinyl aromatic hydrocarbon. Or 5. Manufacturing method.
7). In the step (iii), when the layer (C) is peeled off, the peeling force of the exposed portion of the photosensitive resin constituting body is 6 N / cm or less. ~ 6. Any one of the manufacturing methods.
8). In the step (iii), the peeling force of the exposed portion of the photosensitive resin structure when peeling the layer (C) is 3 N / cm or less. ~ 6. The manufacturing method as described in any one of these.
9. In the step (iii), the photosensitive resin component is heated to 50 ° C. or higher and 180 ° C. or lower. ~ 8. Any one of the manufacturing methods.
10. 1. The thickness of the layer (A) is from 0.5 mm to 10 mm. ~ 9. Any one of the manufacturing methods.
11. Above 1. -10. A flexographic printing plate produced by any one of the production methods.

  According to the present invention, the amount of generated waste and contaminated wastewater by-products is small, which is preferable from the viewpoint of environmental impact, and is a low-cost and shortened plate-making time, and has excellent flexibility as a flexographic printing plate. A manufacturing method and a flexographic photosensitive resin composition for release development are provided.

Hereinafter, the best mode for carrying out the present invention (hereinafter referred to as the present embodiment) will be described in detail. The present invention is not limited to the following embodiments, and various modifications can be made within the scope of the invention.
The production method of the present invention comprises a photosensitive resin structure comprising a photosensitive resin layer (A), an adhesion adjusting layer (B) adjacent to the layer (A), and an adjacent layer (C) adjacent to the layer (B). The step of exposing the body and curing a part of the layer (A) (step (i)), or exposing the photosensitive resin layer (A) and curing a part of the layer (A), then adjusting the adhesive strength A layer (B) and an adjacent layer (C) adjacent to the layer (B) are laminated so that the layer (B) is in contact with the layer (A) to form a photosensitive resin structure, and then the photosensitive resin structure After the step of exposing the body (step (ii)) and the step (i) or (ii), the unexposed portion of the layer (C) and the layer (B) is peeled off to thereby remove the unexposed layer (A). And a step of removing at least a part of the cured portion (step (iii)).
In the production method of the present invention, the photosensitive resin layer (A) or a layer exposed from the photosensitive resin layer (A), the adhesive strength adjusting layer (B), and the adjacent resin layer (C) laminated in this order are exposed. The adhesive force between the photosensitive resin layer (A) and the adhesive force adjusting layer (B) (the peeling force between the layer (A) and the layer (B)) is not increased or greatly decreased, or the adhesive force adjusting layer (B ) And the adjoining layer (C) (the peeling force between the layer (B) and the layer (C)) decreases or does not increase greatly, so the unexposed portions of the layer (C) and the layer (C) are peeled off. By doing so, it becomes possible to remove at least a part of the uncured portion of the layer (A). For this reason, there is little environmental load, low cost, and plate-making time can also be shortened.

[Photosensitive resin composition]
The photosensitive resin structure applicable to the production method of the present invention includes a photosensitive resin (A), an adhesive force adjusting layer (B) adjacent to the layer (A), and an adjacent layer (C) adjacent to the layer (B). )including.
[Photosensitive resin layer (A)]
The photosensitive resin layer (A) includes a photosensitive resin composition or a composition obtained by partially curing the photosensitive resin composition. As the photosensitive resin layer (A), known ones such as a resin composition containing a binder resin, a photopolymerizable monomer and a photopolymerization initiator can be used, and preferably a thermoplastic elastomer (a), light It is preferable to use a photosensitive resin composition containing a polymerizable monomer (b) and a photopolymerization initiator (c).
There are a wide variety of materials for the thermoplastic elastomer (a). Here, the “thermoplastic elastomer” means an elastomer that exhibits rubber elasticity near normal temperature, hardly undergoes plastic deformation, and is plasticized by heat when the composition is mixed by an extruder or the like.

  Specific examples of the thermoplastic elastomer (a) include, for example, a styrene / butadiene block copolymer, a styrene / isoprene block copolymer, a styrene / ethylene / butylene block copolymer, a styrene / butadiene rubber and the like, that is, at least one conjugated diene unit or conjugated diene. Thermoplastic elastomer block copolymer comprising a first polymer block mainly composed of unit hydrogenated product and a second polymer block mainly composed of at least one vinyl aromatic hydrocarbon unit, EPDM, propylene / ethylene / Olefin-based thermoplastic elastomers such as propylene block copolymers, polyurethane-based thermoplastic elastomers, polyester-based thermoplastic elastomers, polyamide-based thermoplastic elastomers, vinyl chloride-based thermoplastics Elastomers, fluorine-based thermoplastic elastomer, and silicone-based thermoplastic elastomer. These thermoplastic elastomers can be used alone or in combination of two or more.

  From the viewpoint of moldability in an extruder or the like, a thermoplastic elastomer (a), a first polymer block mainly composed of at least one conjugated diene unit or a hydrogenated conjugated diene unit, and at least one vinyl aroma It is preferable to contain a thermoplastic elastomer block copolymer containing a second polymer block mainly composed of an aromatic hydrocarbon unit. The above “mainly” means that the polymer block contains 50 wt% or more. Among these, 80 wt% or more is preferable, and 90 wt% or more is more preferable. The thermoplastic elastomer block copolymer may contain a third component block, if necessary.

  Conjugated diene units include, for example, 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 2-methyl-1,3-pentadiene, 1,3-hexadiene, 4,5-diethyl-1, Examples include monomers of 3-octadiene, 3-butyl-1,3-octadiene, and chloroprene. Among them, 1,3-butadiene is preferable from the viewpoint of wear resistance. These conjugated diene units can be used alone or in combination of two or more. The vinyl content in the total amount of butadiene in the polymer block mainly composed of conjugated diene, for example, the content of 1,2-butadiene or 3,4-isoprene is not particularly limited. Examples of the vinyl aromatic hydrocarbon unit include styrene, t-butylstyrene, divinylbenzene, 1,1-diphenylstyrene, N, N-dimethyl-p-aminoethylstyrene, N, N-diethyl-p-aminoethylstyrene, Examples include vinyl pyridine, p-methyl styrene, tertiary butyl styrene, α-methyl styrene, 1,1-diphenylethylene and the like. Among them, the photosensitive resin component can be molded smoothly at a relatively low temperature. To styrene is preferred. These vinyl aromatic hydrocarbon units can be used alone or in combination of two or more.

The content of the vinyl aromatic hydrocarbon unit in the block copolymer is preferably 25 wt% or less from the viewpoint of high moldability of the photosensitive resin composition. On the other hand, 13 wt% or more is preferable in that the cold flow resistance of the photosensitive resin component is high. The range of 15 wt% to 24 wt% is more preferable, and the range of 16 wt% to 23 wt% is more preferable.
The number average molecular weight (Mn) of the thermoplastic elastomer is preferably 20,000 to 250,000 from the viewpoint of cold flow resistance of the photosensitive resin constituent. 30,000 to 200,000 are more preferable, and 40,000 to 150,000 are more preferable. Here, the number average molecular weight (Mn) is a polystyrene equivalent molecular weight measured by gel permeation chromatography (GPC).

The content of the thermoplastic elastomer (a) in the photosensitive resin composition is that the cold flow resistance of the photosensitive resin component is high, and (a), (b), (c) in the photosensitive resin composition. ) Is preferably not less than 69 wt% and is preferably not more than 95 wt% because the photosensitive resin composition can be easily molded. The range of 75 wt% to 90 wt% is more preferable, and the range of 80 wt% to 90 wt% is more preferable.
Examples of the photopolymerizable monomer (b) include esters such as acrylic acid, methacrylic acid, fumaric acid and maleic acid, derivatives of acrylamide and methacrylamide, allyl esters, styrene and derivatives thereof, and N-substituted maleimide compounds.

  Specific examples include diacrylates and dimethacrylates of alkanediols such as hexanediol and nonanediol, or diacrylates and dimethacrylates of ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, polyethylene glycol, butylene glycol, and trimethylol. Propane tri (meth) acrylate, dimethylol tricyclodecane di (meth) acrylate, isobornyl (meth) acrylate, phenoxypolyethylene glycol (meth) acrylate, pentaerythritol tetra (meth) acrylate, N, N'-hexamethylenebisacrylamide And methacrylamide, styrene, vinyltoluene, divinylbenzene, diacrylphthalate, triallylsia Rate, diethyl fumarate, dibutyl fumarate, dioctyl fumarate, distearyl fumarate, butyl octyl fumarate, diphenyl fumarate, dibenzyl ester fumarate, dibutyl maleate, dioctyl maleate, Examples thereof include bis (3-phenylpropyl) fumarate, dilauryl fumarate, dibehenyl fumarate, N-lauryl maleimide, and the like. These may be used alone or in combination of two or more.

The content of the photopolymerizable monomer (b) in the photosensitive resin composition is such that when the sum of the components (a), (b) and (c) in the photosensitive resin composition is 100 wt%, the printing plate 1 wt% or more is preferable from the viewpoint of high scratch resistance of the convex portion of the resin, and 20 wt% or less is preferable from the viewpoint of high cold flow resistance of the photosensitive resin component and high flexibility of the printing plate. The range of 2 wt% to 15 wt% is more preferable, and the range of 4 wt% to 12 wt% is more preferable.
The photopolymerization initiator (c) is a compound that absorbs light energy and generates radicals. Various known compounds can be used, and various organic carbonyl compounds, particularly aromatic carbonyl compounds are preferred. It is.

  Specific examples include benzophenone; 4,4-bis (diethylamino) benzophenone; t-butylanthraquinone; 2-ethylanthraquinone; thioxanthones such as 2,4-diethylthioxanthone, isopropylthioxanthone, and 2,4-dichlorothioxanthone; Acetophenone, 2,2-methoxy-phenylacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzyldimethyl ketal, 1-hydroxycyclohexyl-phenyl ketone, 2-methyl-2-morpholino (4- Acetophenones such as thiomethylphenyl) propan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone; benzoin methyl ether, benzoin ethyl ether, Benzoin ethers such as inisopropyl ether and benzoin isobutyl ether; 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide, bis (2, Acylphosphine oxides such as 4,6-trimethylbenzoyl) -phenylphosphine oxide; methylbenzoylformate; 1,7-bisacridinylheptane; 9-phenylacridine; These may be used alone or in combination of two or more.

The content of the photopolymerization initiator (c) is such that the fine points and the reproducibility of characters are high, and the transmittance of active light such as ultraviolet rays can be kept in a preferable range. When the sum of the components a), (b), and (c) is 100 wt%, it is preferably in the range of 0.1 wt% to 10 wt%. The range of 0.5 wt% to 5 wt% is more preferable.
As the photopolymerization initiator (c), a decay type photopolymerization initiator and a hydrogen abstraction type photopolymerization initiator may be used in combination. Since the image reproducibility and abrasion resistance of the printing plate are high, the amount of the hydrogen abstraction type photopolymerization initiator in the photosensitive resin composition is the sum of the components (a), (b), and (c). When it is 100 wt%, 1 wt% or less is preferable. 0.5 wt% or less is more preferable.

In addition to the above (a), (b) and (c), the photosensitive resin composition includes various auxiliary additives such as a plasticizer, a polar group-containing polymer, a thermal polymerization inhibitor, an ultraviolet absorber, and an antihalation agent. , A light stabilizer, a surface treatment agent such as silicone oil, a photoluminescence tag (a substance that is excited by an external energy source and emits the obtained energy in the form of light and / or radiation), and the like. The total amount of auxiliary additive components is preferably 10 to 50 parts by mass, more preferably 20 to 40 parts by mass with respect to 100 parts by mass of the photosensitive resin composition.
Plasticizers include hydrocarbon oils such as naphthene oil and paraffin oil; conjugated diene rubbers mainly composed of liquid diene such as liquid acrylonitrile-butadiene copolymer and liquid styrene-butadiene copolymer; number average molecular weight of 2,000 or less Polystyrene, sebacic acid ester, phthalic acid ester and the like. These may be provided with a photopolymerizable reactive group. These plasticizers may be used alone or in combination of two or more.

Examples of the polar group-containing polymer include water-soluble or water-dispersible copolymers having a hydrophilic group such as a carboxyl group, amino group, hydroxyl group, phosphoric acid group, and sulfonic acid group, or a polar group such as a salt thereof. . More specifically, carboxyl group-containing NBR, carboxyl group-containing SBR, a polymer of an aliphatic conjugated diene containing a carboxyl group, an emulsion polymer of an ethylenically unsaturated compound having a phosphate group or a carboxyl group, a sulfonate group containing Examples include polyurethane and carboxyl group-containing butadiene latex. From the viewpoint of the resolution of the resulting printing plate, carboxyl group-containing butadiene latex is preferred. These polar group-containing polymers may be used alone or in combination of two or more.
Although there is no restriction | limiting in particular in the thickness of the photosensitive resin layer (A), 0.5 mm or more is preferable from the point of avoiding printing of a printing non-image part, 10 mm or less is preferable from the point of printing plate resolution, and it is 1 mm or more and 8 mm or less. It is more preferable.

[Adhesive strength adjusting layer (B)]
The adhesive force adjusting layer (B) is a layer that is in contact with the adhesive force adjusting layer (B), that is, the peeling force from the photosensitive resin layer (A) or the adjacent layer (C) is changed by exposure of the photosensitive resin structure. It means the layer to do. In the production method of the present invention, in the unexposed part (uncured part) of the photosensitive resin structure, the adhesive force between the adhesive force adjusting layer (B) and the adjacent layer (C), and the adhesive force adjusting layer (B) and the photosensitive layer. Both the adhesive force with the photosensitive resin layer (A) are higher than the breaking force inside the unexposed portion of the photosensitive resin layer or the peeling force between the photosensitive resin layer and the support, and the exposed portion (cured) of the photosensitive resin structure. Part), the adhesive force (adhesive force between the layer (B) and the layer (A)) between the adhesive strength adjusting layer (B) and the photosensitive resin (A) is not increased or greatly decreased, and the photosensitive resin layer exposure is performed. The breaking force inside the exposed portion and inside the exposed portion of the layer (B) is greatly increased, and in some cases, the adhesive force between the adhesive force adjusting layer (B) and the adjacent layer (C) (the layer (B) and the layer (C) Since the peeling force does not decrease or rises significantly, the unexposed part of the layer (B) and the layer (C) are peeled to reduce the uncured part of the layer (A). It becomes possible to remove a portion. At the time of peeling, the unexposed portion of the layer (B) is peeled off together with the layer (C), but the exposed portion of the layer (B) remains as a printing plate together with the layer (A). The peel strength when peeling the layer (C) in the exposed portion of the photosensitive resin structure is preferably 6N or less per 1 cm width at 23 ° C. from the viewpoint of ease of release development, and 3N or less. More preferred.
The material of the adhesive force adjusting layer (B) is not particularly limited, but preferably has an elastomeric adhesive.

  The elastomeric adhesive is a general term for adhesives mainly composed of rubber-like elastic materials, and examples of the adhesive include solvent type, emulsion / latex type, film type and block type. The form is not limited to these forms. Examples of elastomeric adhesives include natural rubber adhesives, recycled rubber adhesives obtained by depolymerizing vulcanized rubber, chloroprene rubber adhesives, nitrile rubber adhesives, styrene / butadiene rubber adhesives, heat Examples thereof include a plastic elastomer adhesive and a butyl rubber adhesive. Among them, a thermoplastic elastomer-based adhesive is preferable, and among them, a first polymer block mainly composed of at least one conjugated diene unit or a conjugated diene unit hydrogenated product, and at least one vinyl aromatic hydrocarbon unit as a main component. It is preferable to include a thermoplastic elastomer block copolymer including the second polymer block. And a thermoplastic elastomer block copolymer comprising a first polymer block mainly comprising a conjugated diene unit hydrogenated product and a second polymer block mainly comprising at least one vinyl aromatic hydrocarbon unit. More preferably, the thermoplastic comprises a first polymer block mainly composed of at least one maleic-modified conjugated diene unit and a second polymer block mainly composed of at least one vinyl aromatic hydrocarbon unit. Most preferably, it contains an elastomeric block copolymer. These can be used alone or in combination of two or more.

The elastomer-based adhesive is 30 wt% in the adhesive force adjusting layer (B) from the viewpoint of improving the adhesion between the unexposed portion of the adhesive force adjusting layer (B) and the unexposed portion of the photosensitive resin layer (A). It is preferable that it is the range of% -95 wt%. A range of 50 wt% to 85 wt% is more preferable.
Furthermore, various auxiliary additive components such as a photopolymerizable monomer, a photopolymerization initiator, a plasticizer, a thermal polymerization inhibitor, an ultraviolet absorber, an antihalation agent, a light stabilizer, silicon oil, A surface treating agent such as a urethane-based adhesive can be added. In particular, those containing a photopolymerizable monomer and a photopolymerization initiator are preferable from the viewpoint of adjusting the adhesive force during peeling development.
As the photopolymerizable monomer and the photopolymerization initiator, those similar to the photosensitive resin layer can be used.

Plasticizers include hydrocarbon oils such as naphthene oil and paraffin oil; conjugated diene rubbers mainly composed of liquid diene such as liquid acrylonitrile-butadiene copolymer and liquid styrene-butadiene copolymer; number average molecular weight of 2,000 or less Polystyrene, sebacic acid ester, phthalic acid ester and the like, and may have a hydroxyl group or a carboxyl group at the terminal.
The adhesive force adjusting layer (B) can contain a urethane-based adhesive.
The urethane-based adhesive generally includes a reaction product of a compound having an isocyanate group and a compound having active hydrogen. In particular, a reaction product of a polyfunctional isocyanate compound and a polyol compound having a hydroxyl group at the terminal is preferable. The polyol compound may have a polyester structure, a polyurethane structure, a polybutadiene structure, or a combination thereof. Of these, polyols having a polybutadiene structure are preferred.

When the compound having an isocyanate group and the compound having active hydrogen are reacted, “number of isocyanate functional groups per molecule of the compound having isocyanate group × number of moles of compound having isocyanate group” / “1 of compound having active hydrogen” The number of active hydrogen functional groups per molecule × number of moles of compound having active hydrogen ”is preferably in the range of 0.5 to 5. A range of 0.7 to 3 is more preferable.
Examples of polyfunctional isocyanates include tolylene diisocyanate, 4,4-diphenylmethane diisocyanate, xylylene diisocyanate, hexamethylene diisocyanate, and conditions in which these polyfunctional isocyanates are excessive in terms of functional group equivalents such as pentaerythritol and trimethylolpropane. There are compounds made by addition reaction with polyfunctional alcohols. These can be used alone or in combination of two or more.

A polyol having a polyester structure is obtained by a polycondensation reaction with a dicarboxylic acid component under an excess of a diol component. Here, as the diol component, a diol having a linear and branched aliphatic saturated hydrocarbon as a skeleton, a diol having a structure in which ethylene oxide is added to bisphenol A and bisphenol A, polyoxyalkylene glycols, and these diol components Can be used. On the other hand, as the dicarboxylic acid component, dicarboxylic acid having a skeleton of linear and branched aliphatic saturated hydrocarbon, terephthalic acid, isophthalic acid, and a mixture of these dicarboxylic acid components can be used.
A polyol having a polyurethane structure can also be obtained by a polyaddition reaction with a diisocyanate compound under an excess of a diol component as described above. Examples of the diisocyanate compound include tolylene diisocyanate, 4,4-diphenylmethane diisocyanate, xylylene diisocyanate, hexamethylene diisocyanate, and mixtures of these diisocyanate compounds.

The polyol having both polyester and polyurethane structures can be obtained by reacting a polyol having a polyester structure synthesized in advance with an excess amount of the diisocyanate compound.
Here, when the molecular weight of the polyol is low, the tackiness of the reaction product with the polyfunctional isocyanate is increased, and the handling property after coating on the support is hindered. On the other hand, from the viewpoint of reactivity with the polyfunctional isocyanate, if the molecular weight is too large, the urethanization reaction is delayed. Therefore, the number average molecular weight of the polyol is preferably 10,000 to 100,000.
These polyol compounds can be used alone or in combination of two or more.
The urethane-based adhesive is preferably in the range of 0.1 wt% to 20 wt% in the adhesive force adjusting layer (B) from the viewpoint of easy peeling development. A range of 0.1 wt% to 5 wt% is more preferable.

[Adjacent layer (C)]
In the manufacturing method of this invention, the photosensitive resin structure containing the adjacent layer (C) adjacent to an adhesive force adjustment layer (B) is used. Examples of the adjacent layer include a cover film (C1), an undercoat layer (C2) of the cover film, and the like, and an improvement in adhesion between the adhesive strength adjusting layer (B) and the adjacent layer (C) of the photosensitive resin structure. From this point, the undercoat layer (C2) of the cover film is preferable.
Examples of the cover film (C1) include polypropylene films, polyethylene films, polyester films such as polyethylene terephthalate and polyethylene naphthalate, and polyamide films. A dimensionally stable polyester film having a thickness in the range of 15 to 100 μm is preferred. The cover film may be surface-treated for adjusting the adhesive strength. Specifically, corona treatment, flame treatment, chemical treatment with alkali or the like, and providing at least one undercoat layer on the surface of the film can be mentioned.

The main component constituting the undercoat layer (C2) is preferably a polymer of (meth) acrylate. For example, a polymer such as methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, glycidyl (meth) acrylate, or a copolymer thereof is used. Further, if necessary, these (co) polymers can be used after being copolymerized with (meth) acrylic acid, styrene, acrylonitrile, vinyl chloride or the like. The other component of the undercoat layer preferably has a urethane bond, and more preferably has a urethane bond obtained from an isocyanate compound having one or more aromatic rings. As such a compound, the reaction product of the compound which has the following active hydrogens, and the compound which has an isocyanate group can be mentioned, for example. Examples of the component having active hydrogen include diols such as ethylene glycol, 1,4-butanediol, neopentyl glycol, or polyether diol composed of a polyether thereof. Furthermore, since the polyester compound can also have active hydrogen, a urethane bond can be generated. For example, examples of the dicarboxylic acid component of the polyester compound include terephthalic acid and isophthalic acid, and examples of the alcohol component include ethylene glycol, 1,4-butanediol, and their polyether polyol compounds. Condensates of these dicarboxylic acid components and alcohol components (diol, polyol) can be used. Examples of the polyisocyanate include aromatic isocyanates such as toluene diisocyanate and 4,4-diphenylenemethane diisocyanate.
The photosensitive resin constituent can further include a support for supporting the photosensitive resin layer (A), an adhesive layer, and the like.

[Support, adhesive layer]
Examples of the support include polypropylene films, polyethylene films, polyester films such as polyethylene terephthalate and polyethylene naphthalate, and polyamide films. A dimensionally stable polyester film having a thickness in the range of 75 to 300 μm is preferred.
It is preferable to provide an adhesive layer between the support and the photosensitive resin layer. Examples of the adhesive layer include a composition having a binder polymer such as polyurethane, polyamide or thermoplastic elastomer and an adhesive active component such as an isocyanate compound or an ethylenically unsaturated compound. Furthermore, various auxiliary additive components such as plasticizers, thermal polymerization inhibitors, ultraviolet absorbers, antihalation agents, light stabilizers, photopolymerization initiators, photopolymerizable monomers, dyes and the like are added to the adhesive layer. I can do it.

In order to obtain higher adhesion between the adhesive layer and the polyester film as the support, the surface of the film is subjected to corona treatment, flame treatment, chemical treatment with alkali or the like, and at least one undercoat layer. It is further preferable to provide
The main component constituting the undercoat layer is preferably a polymer of (meth) acrylate. For example, a polymer such as methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, glycidyl (meth) acrylate, or a copolymer thereof is used. Further, if necessary, these (co) polymers can be used after being copolymerized with (meth) acrylic acid, styrene, acrylonitrile, vinyl chloride or the like. The other component of the undercoat layer preferably has a urethane bond, and more preferably has a urethane bond obtained from an isocyanate compound having one or more aromatic rings. As such a compound, the reaction product of the compound which has the following active hydrogens, and the compound which has an isocyanate group can be mentioned, for example. Examples of the component having active hydrogen include diols such as ethylene glycol, 1,4-butanediol, neopentyl glycol, or polyether diol composed of a polyether thereof. Furthermore, since the polyester compound can also have active hydrogen, a urethane bond can be generated. For example, examples of the dicarboxylic acid component of the polyester compound include terephthalic acid and isophthalic acid, and examples of the alcohol component include ethylene glycol, 1,4-butanediol, and their polyether polyol compounds. Condensates of these dicarboxylic acid components and alcohol components (diol, polyol) can be used. Examples of the polyisocyanate include aromatic isocyanates such as toluene diisocyanate and 4,4-diphenylenemethane diisocyanate.
The adhesive layer interposed between the support used in the present embodiment and the photosensitive resin layer is prepared by, for example, dissolving a reaction product of the above polyol and polyfunctional isocyanate in an appropriate solvent, and applying and drying on the support. You can get it.

[Production method]
The production method of the present invention comprises a photosensitive resin structure comprising a photosensitive resin layer (A), an adhesion adjusting layer (B) adjacent to the layer (A), and an adjacent layer (C) adjacent to the layer (B). The step of exposing the body and curing a part of the layer (A) (step (i)), or exposing the photosensitive resin layer (A) and curing a part of the layer (A), then adjusting the adhesive strength A layer (B) and an adjacent layer (C) adjacent to the layer (B) are laminated so that the layer (B) is in contact with the layer (A) to form a photosensitive resin structure, and then the photosensitive resin structure After the step of exposing the body (step (ii)) and the step (i) or (ii), the unexposed portion of the layer (C) and the layer (B) is peeled off to thereby remove the unexposed layer (A). And a step of removing at least a part of the cured portion (step (iii)).

[Step (i)]
The production method of the photosensitive resin layer (A) is not particularly limited. For example, the raw material of the photosensitive resin composition is dissolved and mixed in a suitable solvent such as chloroform, tetrachloroethylene, methyl ethyl ketone, toluene and the like. , By casting into a mold and evaporating the solvent to form a plate, or after kneading with a kneader, roll mill or screw extruder without using a solvent, desired on a support by a calender roll or press There is a method of molding to a thickness of.
The method of laminating the photosensitive resin layer (A), the adhesion adjusting layer (B), and the adjacent layer (C) is not particularly limited, but the raw material for the adhesive adjusting layer (B) is dissolved in a suitable solvent, A cover film (C1) having an undercoat layer (C2) or a cover film (C1) not having an undercoat layer (C2) is laminated or press-bonded onto the photosensitive resin layer (A) and dried. Alternatively, the adhesive strength adjusting layer (B) solution is applied on the cover film (C1) and dried, and then laminated or press-bonded so that the adhesive strength adjusting layer (B) is in contact with the photosensitive resin layer (A). Also good.
When the adhesive strength adjusting layer (B) and the cover film (C1) are adhered to the sheet-formed photosensitive resin layer (A) by roll lamination, and then heat-pressed on the support, the photosensitive resin has higher thickness accuracy. A structure can be obtained.
Although there is no restriction | limiting in particular in the thickness of the photosensitive resin layer (A), 0.5 mm or more is preferable from the point of avoiding printing of a printing non-image part, 10 mm or less is preferable from the point of printing plate resolution, and it is 1 mm or more and 8 mm or less. It is more preferable.

  The photosensitive resin structure obtained as described above is exposed, and a part of the photosensitive resin layer (A) is cured. The exposure method is not particularly limited. In order to make a flexographic printing plate from a photosensitive resin composition for flexographic printing plates, for example, the following method can be used. First, if necessary, the entire surface is exposed to ultraviolet light through a support of the constituent (back exposure), and the photosensitive resin composition is cured to form a thin uniform cured layer. Although back exposure is not essential, it is preferable to perform back exposure from the viewpoint of image reproducibility of the flexographic printing plate. Next, a negative film is placed on the cover film (C1), and exposure (relief exposure) is performed on the photosensitive resin structure from the negative film side. When relief exposure and back exposure are used in combination, either may be performed first, or both may be performed simultaneously. Examples of the exposure light source include a high-pressure mercury lamp, an ultraviolet fluorescent lamp, a metal halide lamp, a carbon arc lamp, a xenon lamp, and sunlight.

[Step (ii)]
In the production method of the present invention, instead of the above step (i), the photosensitive resin layer (A) is exposed and a part of the layer (A) is cured, and then the adhesive force adjusting layer (B) and the layer ( The adjacent layer (C) adjacent to B) is laminated so that the layer (B) is in contact with the layer (A) to form a photosensitive resin structure, and then the photosensitive resin structure is exposed (step (step ( It is also possible to adopt ii)).
For example, after a negative film is placed on the photosensitive resin layer (A) and the relief exposure is performed, the adhesive force adjusting layer (B) is laminated so as to be in contact with the photosensitive resin layer (A). Adjacent layers (C) such as a cover film (C1) can be laminated so as to be in contact with each other, and the photosensitive resin constituent can be exposed.
Examples of the method for producing the photosensitive resin layer (A) and the method for laminating the adhesion adjusting layer (B) and the adjacent layer (C) on the exposed photosensitive resin layer (A) include, for example, the above step (i The method similar to the method described in the above can be adopted.

[Step (iii)]
In the production method of the present invention, after the step (i) or (ii), at least the uncured portion of the photosensitive resin layer (A) is peeled off by peeling off the adhesion adjusting layer (B) and the adjacent layer (C). A step of removing a part (step (iii), hereinafter may be referred to as “peel development step”). That is, the unexposed photosensitive resin is peeled simultaneously by peeling off the unexposed portion and the adjacent layer (C) of the adhesive force adjusting layer (B). At the time of peeling, the exposed portion of the layer (B) remains together with the layer (A) to constitute a printing plate.
The method of peeling is not particularly limited. For example, the support / cover film is fixed with a tape or the like, and the cover film / support is peeled off from the end of the photosensitive resin component. For example, a method of fixing and peeling with a tensioning device or the like may be used. In order not to damage the manufactured flexographic printing plate, a method in which the support side is fixed and the unexposed portion of the adjacent layer (C) such as the cover film (C1) and the adhesion adjusting layer (B) is peeled off is preferable.
In order to reduce the breaking force inside the unexposed portion of the photosensitive resin layer, it is preferable that the exposed photosensitive resin component is heated and then peeled off.

The method of heating is not particularly limited, such as placing the photosensitive resin component on a heater, heating with an infrared heater, or placing in a heating oven. The heating temperature is preferably 50 to 180 ° C, more preferably 70 to 180 ° C, and still more preferably 80 to 160 ° C. In the case of heating, it may be from either the support side or the cover film side, but is preferably from the cover film side.
The peeling force of the unexposed portion of the photosensitive resin structure, that is, the breaking force inside the unexposed portion of the photosensitive resin layer or the peeling force between the photosensitive resin layer and the support is 15 N or less per 1 cm width at the peeling temperature. Preferably, those that are 10N or less are more preferable, and those that are 6N or less are more preferable.

Further, the peel strength of the exposed portion of the photosensitive resin structure, that is, the adhesive strength between the adhesion adjusting layer (B) and the adjacent layer (C) (the peel strength between the layer (B) and the adjacent layer (C)) is 23 ° C. What becomes 6N or less per 1 cm width is preferable, what becomes 3N or less is more preferable, and what becomes 2N or less is still more preferable.
If necessary, after the peeling development, the remaining unexposed portion may be developed by other known development methods. For example, a method of washing away with a developing solution, or contacting an unexposed portion heated to 40 ° C. to 200 ° C. with an absorbable absorbing layer and removing the absorbing layer to remove the unexposed portion.

Organic solvents used for solvent development of unexposed areas include esters such as heptyl acetate and 3-methoxybutyl acetate; hydrocarbons such as petroleum fractions, toluene and decalin; and chlorine-based compounds such as tetrachloroethylene What mixed alcohols, such as a propanol, a butanol, and a pentanol, into the organic solvent can be mention | raise | lifted.
The aqueous developer used to develop the unexposed area contains one or more nonionic, anionic, cationic or amphoteric surfactants. Specific examples of the anionic surfactant include linear alkylbenzene sulfonate having alkyl having an average carbon number of 8 to 16, α-olefin sulfonate having an average carbon number of 10 to 20, alkyl group or alkenyl group. C4-C10 dialkylsulfosuccinate, fatty acid lower alkyl ester sulfonate, average C10-20 alkyl sulfate, average C10-20 linear or branched alkyl or alkenyl group And an alkyl ether sulfate having an average of 0.5 to 8 moles of ethylene oxide and a saturated or unsaturated fatty acid salt having an average of 10 to 22 carbon atoms.

Specific examples of the cationic surfactant include alkylamine salts, alkylamine ethylene oxide adducts, alkyltrimethylammonium salts, alkyldimethylbenzylammonium salts, sapamine-type quaternary ammonium salts, and pyridium salts.
Specific examples of nonionic surfactants include polyethylene glycol type higher alcohol alkylene oxide adducts, alkylphenol alkylene oxide adducts, fatty acid alkylene oxide adducts, polyhydric alcohol fatty acid ester alkylene oxide adducts, and higher alkyl amine alkylenes. Oxide adducts, fatty acid amide alkylene oxide adducts, fat and oil alkylene oxide adducts, and polypropylene glycol alkylene oxide adducts, polyhydric alcohol fatty acid esters of glycerol, fatty acid esters of pentaerythritol, fatty acid esters of sorbitol and sorbitan, Examples include fatty acid esters of sugars, alkyl ethers of polyhydric alcohols, and fatty acid amides of alkanolamines.

Specific examples of the amphoteric surfactant include sodium laurylaminopropionate and lauryldimethylbetaine.
The concentration of the surfactant is not particularly limited, but is usually used in the range of 0.5 to 10 wt% with respect to the total amount of the developer.
If necessary, the aqueous developer may contain a development aid such as a cleaning accelerator and a pH adjuster in addition to the surfactant. Examples of the cleaning accelerator include amines such as monoethanolamine, diethanolamine and triethanolamine, ammonium salts such as glycol ethers and tetramethylammonium hydroxide, and paraffinic hydrocarbons. Examples of the pH adjusting agent include sodium borate, sodium carbonate, sodium silicate, sodium metasilicate, sodium succinate, sodium acetate, and the like. The development aids may be used alone or in combination of two or more. The boiling point of the development aid is preferably 130 ° C. or higher at normal pressure. When the boiling point is less than 130 ° C., when the water is evaporated from the developer and recovered as a condensate, a considerable amount of the development aid tends to be evaporated and removed together with the water. Alternatively, when the development aid is used for the purpose of adjusting the concentration of the developing solution, it takes time and effort to measure and adjust the amount of the entrained solvent in order to stabilize the performance of the developing solution.

You may add an antifoamer, a dispersing agent, a corrosion inhibitor, and an anti-corruption agent to a developing solution as needed.
The unexposed portion is washed out by spraying from a nozzle or brushing with a brush.
Examples of the absorbing layer that absorbs the heated unexposed portion include nonwoven materials, paper materials, fiber fabrics, open cell foams, and porous materials. Preferred absorbent layers are nonwoven materials made of nylon, polyester, polypropylene, polyethylene, and combinations of these nonwoven materials. A particularly preferred absorbent layer is a nonwoven continuous web of nylon or polyester.
From the viewpoint of shortening the plate-making time by the above-described peeling development, it is preferable to develop by other methods after removing 60% or more of the uncured portion of the layer (A), and after removing 80% or more, other methods It is more preferable to develop by, and it is more preferable to develop by another method after removing 90% or more.
After development, the cured photosensitive resin may be subjected to post-treatment exposure. As post-processing exposure, a method of irradiating the surface with light having a wavelength of 300 nm or less is common. If necessary, light larger than 300 nm may be used in combination.

Hereinafter, the present embodiment will be described more specifically with reference to examples and comparative examples, but the present embodiment is not limited to these examples. The physical properties in Examples and Comparative Examples were measured by the following methods.
1. Number average molecular weight (Mn)
The number average molecular weight (Mn) is a polystyrene equivalent molecular weight measured by gel permeation chromatography (GPC). LC-10 (manufactured by Shimadzu Corporation, trade name) is used for the measuring device, two TSKgelGMHXL (4.6 mm ID × 30 cm) are used for the column, the oven temperature is 40 ° C., and the solvent is tetrahydrofuran (1.0 ml / min). Measurements were made.
2. Peeling strength of exposed portion of photosensitive resin structure The sample for measuring the adhesive strength of the adhesive force adjusting layer is a part of the cover film from a sample obtained by cutting the exposed photosensitive resin structure into a 1 cm wide × 10 cm long strip. Created by peeling. The cut sample is left in a constant temperature and humidity room at a temperature of 23 ° C. and a relative humidity of 50% for one day, and then the support and the photosensitive resin layer are formed at a speed of 50 mm / min at an angle of 180 ° using a tensile tester. The measurement was performed by peeling the partially peeled cover film. As the tensile tester, AUTOGRAPH AGS-100G (manufactured by Shimadzu Corporation, trade name) was used.

[Reference Example 1] Production of a structure having a cover film, an undercoat layer (adjacent layer) and an adhesive force adjusting layer The cover film and the undercoat layer are coated by coating the adhesive force adjusting layer on the cover film having the undercoat layer. The structure which has (adjacent layer) and an adhesive force adjustment layer was produced.
Ethylene glycol 93 g, neopentyl glycol 374 g and phthalic acid 382 g were subjected to a condensation reaction in an air atmosphere at a reaction temperature of 180 ° C. and a reduced pressure of 1.33 × 10 ³ Pa for 6 hours, and then 125 g of 4,4-diphenylene diisocyanate. And further reacted at 80 ° C. for 5 hours. The obtained resin was made into a 10% aqueous solution, applied onto a melt-extruded polyethylene terephthalate film, and after application, a cover film having an undercoat layer was produced by biaxial stretching. The obtained cover film having an undercoat layer (adjacent layer) has a thickness of 50 μm, and the undercoat layer contains a compound having urethane. Tuffprene 912, which is an elastomeric adhesive (trade name, block copolymer of styrene and 1,3-butadiene, manufactured by Asahi Kasei Chemicals Co., Ltd.) is used as a solution for the adhesive force adjusting layer that coats the undercoat layer (adjacent layer). 19 parts by mass, 19 parts by mass of D1112CP (product name, block copolymer of styrene and isoprene), 12 parts by mass of paraffin oil (average carbon number 33, average molecular weight 470), which is an elastomeric adhesive 24 parts by mass of liquid polybutadiene NISSO-B2000 (Nippon Soda Co., Ltd., trade name), 2.5 parts of 1,9-nonanediol diacrylate which is a photopolymerizable monomer, 1,6-hexanediol which is a photopolymerizable monomer 3 parts dimethacrylate, epoxy compound which is an epoxy compound photopolymerizable monomer 3000M (Kyoeisha Chemical Co., Ltd., trade name) 8 parts by mass, mixed solvent prepared by adjusting 8.5 parts of 2,2-dimethoxy-phenylacetophenone as a photopolymerization initiator at a mass ratio of toluene / MEK = 35/65 And a uniform solution having a solid content of 25% by weight was prepared.

After that, the obtained solution was applied on the undercoat layer (adjacent layer) using a knife coater so as to have a thickness of 10 μm, dried at 80 ° C. for 2 minutes, and a 25 μm-thick silicone-treated polyester film was attached. Combined. Thereafter, on the glass plate of the “AFP-1500” exposure machine (trade name, manufactured by Asahi Kasei Chemicals Corporation), an entire surface exposure of 200 mJ / cm ² is performed from the cover film side using an ultraviolet fluorescent lamp having a center wavelength of 370 nm. And a 25 μm thick silicone-treated polyester film was peeled off to obtain a structure having a cover film, an undercoat layer (adjacent layer) and an adhesive force adjusting layer. In addition, the exposure intensity | strength at this time was measured using the UV-35 filter with the UV illuminometer MO-2 type machine made from Oak Manufacturing.
The elastomer adhesive (block copolymer of styrene and 1,3-butadiene) in the adhesive force adjusting layer was 39.6 wt%.

[Reference Example 2] Synthesis of polar group-containing polymer 125 parts by mass of water and an emulsifier (α-sulfo (1- (nonylphenoxy) methyl-2- (2- 3 parts by mass of an ammonium salt of propenyloxy) ethoxy-poly (oxy-1,2-ethanediyl) (trade name Adekaria soap manufactured by Asahi Denka Kogyo Co., Ltd.) was initially charged. 2 parts by weight of acid, 5 parts by weight of methacrylic acid, 60 parts by weight of butadiene, 10 parts by weight of styrene, 23 parts by weight of butyl acrylate, 28 parts by weight of water, 1.2 parts by weight of sodium peroxodisulfate Parts, an emulsifier (trade name Adekaria soap manufactured by Asahi Denka Kogyo Co., Ltd.) of 1 part by mass of an aqueous solution at a constant flow rate for 5 hours and 6 hours After the polymerization was completed by keeping for 1 hour and then cooled, the latex formed was adjusted to pH 7 with sodium hydroxide, and then unreacted substances were removed by steam stripping to finally give a solid concentration of 40%. The polar group-containing polymer aqueous solution was obtained and dried at 60 ° C. to obtain a polar group-containing polymer.

[Example 1]
70 parts by mass of thermoplastic elastomer “KX405” (trade name, Mn 100,000) manufactured by Kraton Polymer Japan Co., Ltd., a block copolymer of styrene and 1,3-butadiene, liquid polybutadiene “LIR305” (manufactured by Kuraray Co., Ltd., product) Name) 20 parts by weight, 9 parts by weight of hexamethylene dimethacrylate as a photopolymerizable monomer, 2 parts by weight of 2,2-dimethoxy-2-phenylacetophenone as a photopolymerization initiator, 2,6-di-t-butyl- 1 part by mass of p-cresol was uniformly kneaded using a kneader heated to 130 ° C. to obtain a photosensitive resin composition.
When the sum of the thermoplastic elastomer, photopolymerizable monomer and photopolymerization initiator of the obtained photosensitive resin composition is 100 wt%, the thermoplastic elastomer component is 86.4 wt%, and the photopolymerizable monomer component is 11 The photopolymerization initiator component was 2.5 wt%.
The photosensitive resin composition was used in a heat press at 120 ° C., and a 188 μm-thick polyethylene terephthalate film support having a urethane-based adhesive layer was in contact with the photosensitive resin composition and the adhesive strength adjusting layer in Reference Example 1. A photosensitive resin composition of 25 cm length × 25 cm width × about 1 mm thickness, sandwiched between the structure having the cover film, the undercoating layer (adjacent layer) and the adhesive strength adjusting layer obtained in 1. Got the body.

A negative film is placed on the cover film, placed on the glass plate of an “AFP-1500” exposure machine (trade name, manufactured by Asahi Kasei Chemicals Corporation) with the negative film facing upward, and an ultraviolet ray having a central wavelength at 370 nm. using a fluorescent lamp, the first support side, after performing overall exposure 50 mJ / cm ² (the back exposure) and subsequently subjected to relief exposure of 6000 mJ / cm ² through a negative film. The negative film image used included a solid part and a concave / convex line having a width of 500 μm.
The exposure intensity at this time was measured using a UV illuminometer MO-2 type machine manufactured by Oak Manufacturing Co., Ltd. using a UV-35 filter, and the intensity measured on the glass plate for ultraviolet rays from the lower lamp on the side performing back exposure was 10 .3 mW / cm ² , the intensity of ultraviolet rays measured from the upper lamp on the relief exposure side was 12.5 mW / cm ² .
After the exposure was completed, the negative film was removed, and heating was performed for 4 minutes by contacting a 5 mm thick iron plate heated to 150 ° C. from the cover film side. Then, the flexographic printing plate was created by removing the cover film. The uncured portion of the photosensitive resin layer was removed by peeling the cover film and the unexposed portion adhesive force adjusting layer, and the exposed portion adhesive force adjusting layer remained on the flexographic printing plate side.
In addition, the peeling force of the exposed part of the exposed photosensitive resin structure measured by the evaluation method 2 was 1.9 N / cm.

[Example 2]
30 parts by mass of the polar group-containing polymer shown in Reference Example 2, thermoplastic elastomer “KX405” (trade name, Mn 100,000) manufactured by Kraton Polymer Japan Co., Ltd., which is a block copolymer of styrene and 1,3-butadiene Parts, liquid polybutadiene “LIR305” (manufactured by Kuraray Co., Ltd., trade name), 30 parts by mass of hexamethylene dimethacrylate which is a photopolymerizable monomer, 2-butyl and 2-ethylpropane which are photopolymerizable monomers Kneader at 130 ° C. with 8 parts by mass of diol diacrylate, 2 parts by mass of 2,2-dimethoxy-2-phenylacetophenone as a photopolymerization initiator, and 0.3 parts by mass of 2,6-di-t-butyl-p-cresol Was uniformly kneaded to obtain a photosensitive resin composition.
When the sum of the thermoplastic elastomer, photopolymerizable monomer and photopolymerization initiator of the obtained photosensitive resin composition is 100 wt%, the thermoplastic elastomer component is 70.6 wt%, and the photopolymerizable monomer component is 18 The photopolymerization initiator component was 4.7 wt%.
A cover film obtained in Reference Example 1 using a hot press at 120 ° C. and a 188 μm-thick polyethylene terephthalate film support having a urethane-based adhesive layer, and the composition and the adhesive force adjusting layer in contact with this composition. Then, it was sandwiched between the structures having the undercoat layer (adjacent layer) and the adhesive force adjusting layer and molded to a thickness of 1.14 mm to obtain a photosensitive resin structure of 25 cm length × 25 cm width × about 1 mm thickness.

A negative film is placed on the cover film, placed on the glass plate of an “AFP-1500” exposure machine (trade name, manufactured by Asahi Kasei Chemicals Corporation) with the negative film facing upward, and an ultraviolet ray having a central wavelength at 370 nm. using a fluorescent lamp, the first support side, after performing overall exposure 100 mJ / cm ² (the back exposure) and subsequently subjected to relief exposure of 6000 mJ / cm ² through a negative film. The negative film image was the same as in Example 1.
The exposure intensity at this time was measured using a UV illuminometer MO-2 type machine manufactured by Oak Manufacturing Co., Ltd. using a UV-35 filter, and the intensity measured on the glass plate for ultraviolet rays from the lower lamp on the side performing back exposure was 10 .3 mW / cm ² , the intensity of ultraviolet rays measured from the upper lamp on the relief exposure side was 12.5 mW / cm ² .
After the exposure, the negative film was removed, and the cover film was removed in a room at a temperature of 23 ° C. to prepare a flexographic printing plate. The uncured portion of the photosensitive resin layer was removed by peeling the cover film and the unexposed portion adhesive force adjusting layer, and the exposed portion adhesive force adjusting layer remained on the flexographic printing plate side.
The above 2. The adhesive force of the exposed photosensitive resin structure measured by the evaluation method was 1.9 N / cm.

[Comparative Example 1]
As the photosensitive resin composition, “AFP-SH” (trade name, manufactured by Asahi Kasei Chemicals Corporation) having a thickness of 1.14 mm for flexographic printing was used. Remove the cover film provided in advance in the SH, attach the negative film on the exposed protective film, and the negative film faces upward on the glass plate of the “AFP-1500” exposure machine (trade name, manufactured by Asahi Kasei Chemicals Corporation). Position so that, by using an ultraviolet fluorescent lamp having a center wavelength of 370 nm, the first support side, after performing overall exposure 600 mJ / cm ² (the back exposure), subsequently reliefs 6000 mJ / cm ² through a negative film Exposure was performed. The same as in Example 1 was used.
After the exposure is completed, the negative film is removed, and development is performed with “AFP-1500” developing machine (trade name, manufactured by Asahi Kasei Chemicals Co., Ltd.) using tetrachloroethylene / n-butanol = 3/1 (volume ratio) as a developer. In order to restore the thickness swollen with the developing solvent to the original thickness, after drying at 60 ° C. for 2 hours, post-treatment exposure was performed to prepare a flexographic printing plate.
By using the flexographic printing plate manufacturing method described in Examples 1 and 2, it was possible to obtain very little waste and no contaminated wastewater by-product. In the method for producing the flexographic printing plate obtained in Comparative Example 1, a developing solvent is required, which puts a burden on the environment, and the plate-making time is increased.

  According to the present invention, a flexographic printing plate excellent in suitability as a flexographic printing plate, which is preferable from the viewpoint of environmental load because the generation amount of waste and contaminated wastewater by-products is small, is low-cost and shortens the plate-making time, and Can be provided. Therefore, the present invention is useful in the field of general flexographic printing such as films, labels, and cartons.

Claims (11)

The photosensitive resin structure including the photosensitive resin layer (A), the adhesion adjusting layer (B) adjacent to the layer (A), and the adjacent layer (C) adjacent to the layer (B) is exposed, and the layer ( A step of curing a part of A) (step (i)), or after exposing the photosensitive resin layer (A) to cure a part of the layer (A), the adhesion adjusting layer (B) and the layer The adjacent layer (C) adjacent to (B) is laminated so that the layer (B) is in contact with the layer (A) to form a photosensitive resin structure, and then the photosensitive resin structure is exposed (process) (Ii))
After the step (i) or (ii), the unexposed portion of the layer (C) and the layer (B) is peeled to remove at least a part of the uncured portion of the layer (A) (step (step ( iii))
The manufacturing method of the flexographic printing plate containing these.   The manufacturing method of Claim 1 in which the photosensitive resin layer (A) contains a thermoplastic elastomer (a), a photopolymerizable monomer (b), and a photoinitiator (c).   The process according to claim 2, wherein the thermoplastic elastomer (a) contains a block copolymer comprising a polymer block mainly comprising a conjugated diene and a polymer block mainly comprising a vinyl aromatic hydrocarbon.   The manufacturing method as described in any one of Claims 1-3 in which an adhesive force adjustment layer (B) contains an elastomer type adhesive agent (B1).   The manufacturing method as described in any one of Claims 1-3 in which an adhesive force adjustment layer (B) contains an elastomer adhesive (B1), a photopolymerizable monomer, and a photoinitiator.   The production method according to claim 4 or 5, wherein the elastomeric adhesive (B1) contains a block copolymer including a polymer block mainly composed of conjugated diene and a polymer block mainly composed of vinyl aromatic hydrocarbon. .   The manufacturing method according to any one of claims 1 to 6, wherein the peeling force of the exposed portion of the photosensitive resin structure when peeling the layer (C) in the step (iii) is 6 N / cm or less.   The manufacturing method according to any one of claims 1 to 6, wherein the peeling force of the exposed portion of the photosensitive resin structure when peeling the layer (C) in step (iii) is 3 N / cm or less.   The manufacturing method as described in any one of Claims 1-8 which heats the photosensitive resin structural body to 50 to 180 degreeC in the process (iii).   The manufacturing method as described in any one of Claims 1-9 whose thickness of a layer (A) is 0.5 mm or more and 10 mm or less.   The flexographic printing plate manufactured by the manufacturing method as described in any one of Claims 1-10.