JP2013073179A - Flexographic printing original plate for exfoliation development - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flexographic printing original plate capable of deepening relief depth of a flexographic printing plate due to needlessness of back side exposure, thereby enabling a work process to be reduced, and capable of performing exfoliation development with high accuracy.SOLUTION: (A) The peeling force between an unhardened section of a photosensitive layer 16 and a base material adhesion layer 14 is smaller than the peeling force between the unhardened section of the photosensitive layer 16 and a peelable adhesion layer 18. (B) The peeling force between a hardened section after hardening the photosensitive layer 16 and the base material adhesion layer 14 is larger than the peeling force between the hardened section after hardening the photosensitive layer 16 and the peelable adhesion layer 18. (C) The peeling force between the hardened section after hardening the photosensitive layer 16 and the base material adhesion layer 14 is larger than the breaking strength of the hardened section after hardening the photosensitive layer 16. (D) The peeling force between the hardened section after hardening the photosensitive layer 16 and the peelable adhesion layer 18 is smaller than the breaking strength of the hardened section after hardening the photosensitive layer 16.

Description

  The present invention relates to a flexographic printing plate precursor as an original plate suitable for a flexographic printing plate, and more particularly to a flexographic printing plate precursor for peeling development.

  Generally, a flexographic printing plate precursor used for flexographic printing is provided with a photosensitive layer made of a photosensitive resin composition on a support made of a polyester film or the like. The development of the flexographic printing plate is performed by removing a non-exposed portion of the photosensitive layer after exposing a predetermined image on the surface of the photosensitive layer of the original plate.

  As a developing method for a flexographic printing plate, a method is generally known in which uncured portions are removed by brushing in a developing solution. However, since this developing method uses a developing solution, there is a problem that a waste solution of the developing solution comes out and a waste solution treatment is required.

  On the other hand, development methods that do not use such a developer are also known. For example, Patent Document 1 discloses a developing method in which an uncured portion of a photosensitive layer is liquefied by heating and developed by sucking it with a nonwoven fabric. For example, Patent Documents 2 to 3 disclose a developing method in which development is performed by peeling off an uncured portion of a photosensitive layer.

JP 05-19469 A Japanese Patent No. 2550421 JP 2009-204855 A

  In general, in a flexographic printing plate, in order to ensure adhesion between the cured portion of the photosensitive layer after curing and the support, the back side of the photosensitive layer is subjected to the main exposure through the negative from the front side. Then, the photosensitive layer is back-exposed through the support, and a cured layer serving as a base of the cured portion after curing is formed in advance at a predetermined thickness on the support side of the photosensitive layer. Even when the development method is a peeling development method, such back exposure is basically required.

  When back exposure is performed in this way, the relief depth of the photosensitive layer (the difference in height between the convex and concave portions) becomes shallower by the thickness of the formed hardened layer, and image reproducibility that reproduces the negative image. May get worse. There is also a problem that the number of work steps for performing back exposure increases.

  In addition, when performing peel development, it is also a problem to leave the cured portion of the photosensitive layer and peel and remove only the uncured portion with high accuracy to satisfy the negative image reproducibility.

  The problem to be solved by the present invention is that since the back exposure is not required, the relief depth of the flexographic printing plate can be increased and the number of work steps can be reduced accordingly, and the flexographic printing plate precursor for release development that can be developed with high accuracy. Is to provide.

In order to solve the above problems, a flexographic printing plate precursor for peeling development according to the present invention includes a support for supporting a photosensitive layer, a support adhesive layer for bonding between the support and the photosensitive layer, the photosensitive layer, A flexographic printing plate precursor for peeling development, which is laminated in the order of a peeling adhesive layer that bonds between a photosensitive layer and a cover film that covers and protects the photosensitive layer, the cover film, and includes the following (A) to The gist is to satisfy (D).
(A) The peel force between the uncured portion of the photosensitive layer and the support adhesive layer is smaller than the peel force between the uncured portion of the photosensitive layer and the peel adhesive layer. (B) The photosensitive layer. (C) The peeling force between the cured part after curing and the support adhesive layer is larger than the peeling force between the cured part after curing the photosensitive layer and the peeling adhesive layer (C) The peeling force between the cured portion after curing the photosensitive layer and the support adhesive layer is greater than the breaking strength of the cured portion after curing the photosensitive layer. (D) The photosensitive layer is cured. The peeling force between the later cured portion and the release adhesive layer is smaller than the breaking strength of the cured portion after the photosensitive layer is cured.

  At this time, it is preferable that the support adhesive layer contains polyester. At this time, it is preferable that the support adhesive layer further contains a curing agent. The photosensitive layer preferably contains a photopolymerizable monomer, rubber, water-dispersed latex, and photopolymerization initiator.

The peel force between the uncured portion of the photosensitive layer and the support adhesive layer measured in accordance with JIS K6854 is 0.8 N / width 3 cm or less, and is measured in accordance with JIS K6854. It is preferable that the peeling force between a cured portion obtained by curing the photosensitive layer by UV irradiation with a light amount of UVA 19 J / cm ² and the support adhesive layer is 23 N / width 3 cm or more.

  The release adhesive layer preferably contains one or more materials selected from polyvinyl alcohol, polyamide, polyvinyl pyrrolidone, and vinyl pyrrolidone copolymer.

  An infrared ablation layer containing a binder polymer and an infrared absorbing material may be provided between the release adhesive layer and the cover film.

  According to the flexographic printing plate precursor for release development according to the present invention, since the above (A) and (B) are satisfied, the photosensitive layer is cured by main exposure and then subjected to release development. The uncured portion of the layer is peeled from the support adhesive layer, and the cured portion of the photosensitive layer is peeled from the peel adhesive layer. At this time, in order to satisfy the above (C) and (D), the cured portion of the photosensitive layer is left, and only the uncured portion is peeled and removed with high accuracy, so that the negative image reproducibility can be satisfied. . As a result, it is possible to perform peeling development with high accuracy.

  Further, since the above (C) is satisfied, in the cured portion of the photosensitive layer, the cured portion of the photosensitive layer and the support adhesive layer are peeled off before the cured portion is destroyed. There is no adhesion between them. That is, since the adhesiveness between the cured portion of the photosensitive layer after curing and the support is sufficiently secured, it is not necessary to form a base on the photosensitive layer by back exposure. Since the back exposure is not required in this way, the relief depth of the flexographic printing plate can be increased by the amount that the base is not formed, so that the image reproducibility is excellent. In addition, since the foundation is not formed, the work process can be reduced.

  At this time, if polyester is contained in the support adhesive layer, the peeling force between the cured part after curing the photosensitive layer and the support adhesive layer is the uncured part before curing the photosensitive layer. And the peeling force between the adhesive layer and the support adhesive layer. Therefore, it is easy to satisfy the above (A) and (B). Moreover, it is easy to satisfy the above (C). This is because when the support adhesive layer contains polyester, the compatibility of the material of the support adhesive layer with the curable component contained in the photosensitive layer is improved, and a part of the curable component is added to the support adhesive layer. It is presumed that the shift increases the adhesive force (bonding force) between the support adhesive layer and the photosensitive layer after exposure.

  In the case where polyester is contained in the support adhesive layer, if the curing agent is further contained in the support adhesive layer, the adhesive component from the support adhesive layer can be contacted with the ink when performing flexographic printing. Can be prevented from flowing out. Therefore, even when flexographic printing is repeatedly performed, the function as an adhesive layer is maintained over a long period of time.

  And if the said photosensitive layer contains a photopolymerizable monomer, rubber | gum, water dispersion latex, and a photoinitiator, it will be easy to satisfy said (C). Moreover, it is easy to satisfy the above (D). This is presumably because the photopolymerizable monomer easily migrates to the support adhesive layer but hardly migrates to the release adhesive layer. Among them, when the photopolymerizable monomer is an alkyl (meth) acrylic monomer, since it is particularly excellent in compatibility with the polyester, the transition to the support adhesive layer further proceeds, and the support adhesive layer and the photosensitive layer The adhesive force (bonding force) between the two is further increased.

  As described above, the peel force between the uncured part of the photosensitive layer and the support adhesive layer, and the peel force between the cured part after curing the photosensitive layer and the support adhesive layer are specified. By being in this range, it becomes easy to peel at these interfaces, and high-precision peeling development can be performed.

  When the release adhesive layer contains one or more materials selected from polyvinyl alcohol, polyamide, polyvinyl pyrrolidone, and vinyl pyrrolidone copolymer, the cured portion after curing the photosensitive layer The peeling force between the adhesive layer and the peeling adhesive layer is smaller than the peeling force between the uncured portion and the peeling adhesive layer before the photosensitive layer is cured. Therefore, it is easy to satisfy the above (A) and (B). Moreover, it is easy to satisfy the above (D). This is because the release adhesive layer contains polyvinyl alcohol, polyamide, polyvinyl pyrrolidone, and vinyl pyrrolidone copolymer, and is excellent in adhesion (adhesion) to the photosensitive layer when uncured, while the material and the photosensitive layer of the release adhesive layer are excellent. In addition, since the compatibility with the contained curable component is deteriorated and a part of the curable component is prevented from moving to the peeling adhesive layer, the surface of the photosensitive layer in contact with the peeling adhesive layer is cured. This is presumably because the adhesiveness decreases.

1 is a cross-sectional view of a flexographic printing plate precursor according to an embodiment of the present invention. It is sectional drawing of the flexographic printing plate precursor which concerns on other embodiment of this invention. It is process drawing which showed an example of the manufacturing process of the flexographic printing plate obtained from the flexographic printing plate precursor of FIG. FIG. 3 is a process diagram showing an example of a manufacturing process of a flexographic printing plate obtained from the flexographic printing plate precursor of FIG. 2. It is a schematic diagram which shows the peeling test method of a flexographic printing plate precursor. It is a schematic diagram which shows the negative pattern applied to a flexographic printing plate precursor.

  Next, an embodiment of the present invention will be described in detail. FIG. 1 is a sectional view of a flexographic printing plate precursor for peeling development according to an embodiment of the present invention.

  As shown in FIG. 1, a flexographic printing plate precursor for peeling development (hereinafter sometimes simply referred to as a flexographic printing plate precursor) 10 according to an embodiment of the present invention includes a support 12 that supports a photosensitive layer 16, and a support. A support adhesive layer 14 for bonding between the body 12 and the photosensitive layer 16, a photosensitive layer 16, a release adhesive layer 18 for bonding between the photosensitive layer 16 and a cover film 20 covering and protecting the photosensitive layer 16, a cover It consists of the laminated body laminated | stacked in order of the film 20.

  The photosensitive layer 16 is made of a material containing a curable component that cures the exposed portion when exposed. After exposure, the flexographic printing plate precursor 10 has a cured portion formed on a part of the photosensitive layer 16, and the uncured portion is peeled off from the support adhesive layer 14 while leaving the cured portion on the support adhesive layer 14. Thus, development is performed.

In such a configuration, the flexographic printing plate precursor 10 satisfies the following (A) to (D).
(A) The peeling force between the uncured portion of the photosensitive layer 16 and the support adhesive layer 14 is smaller than the peeling force between the uncured portion of the photosensitive layer 16 and the peeling adhesive layer 18 (B) the photosensitive layer 16. (C) Photosensitivity is greater than the peel force between the cured portion after curing the photosensitive layer 16 and the release adhesive layer 18. (D) The photosensitive layer 16 was cured with a peeling force between the cured portion after the layer 16 was cured and the support adhesive layer 14 greater than the breaking strength of the cured portion after the photosensitive layer 16 was cured. The peeling force between the later cured portion and the release adhesive layer 18 is smaller than the breaking strength of the cured portion after the photosensitive layer 16 is cured.

  By satisfying the above (A) to (D), the flexographic printing plate precursor 10 does not need to be formed with a constant thickness on the support 12 side of the photosensitive layer 16 with a constant thickness, and exposure Thereafter, the uncured portion is peeled between the uncured portion of the photosensitive layer 16 and the support adhesive layer 14 in the thickness direction by peeling development. Thereby, since the cured portion of the photosensitive layer 16 is left and only the uncured portion is peeled and removed with high accuracy to satisfy the image reproducibility of the negative, it is possible to perform development with high accuracy.

Although it does not specifically limit as a structure which satisfies both said (A) and (B), For example, the structure of following (1)-(3) can be mentioned. The flexographic printing plate precursor 10 may have any of these configurations, and may have other configurations as long as both (A) and (B) are satisfied.
(1) By curing the photosensitive layer 16, the adhesive force between the photosensitive layer 16 and the support adhesive layer 14 increases. That is, the adhesive force between the cured portion of the photosensitive layer 16 after curing and the support adhesive layer 14 is higher than the adhesive force between the uncured portion of the photosensitive layer 16 and the support adhesive layer 14.
(2) By curing the photosensitive layer 16, the adhesive force between the photosensitive layer 16 and the peeling adhesive layer 18 is reduced. That is, the adhesive force between the cured portion of the photosensitive layer 16 after being cured and the peeling adhesive layer 18 is lower than the adhesive force between the uncured portion of the photosensitive layer 16 and the peeling adhesive layer 18.
(3) It consists of what combined said (1) and (2).

  As a method for obtaining the configuration of (1), for example, a material compatible with the curing component of the photosensitive layer 16 can be used as the material constituting the support adhesive layer 14. Thereby, a part of the curable component is easily transferred to the support adhesive layer 14. When a part of the curable component moves to the support adhesive layer 14, the adhesive force (bonding force) between the support adhesive layer 14 and the photosensitive layer 16 increases after curing.

  As a method of obtaining the configuration of (2), contrary to (1), for example, the material constituting the peeling adhesive layer 18 is not compatible with the cured component of the photosensitive layer 16, or is relatively incompatible. Examples thereof include using materials. This prevents a part of the curable component from moving to the peeling adhesive layer 18. If it does so, the adhesive force (bonding force) between the peeling adhesive layer 18 and the photosensitive layer 16 will not increase after hardening. At this time, since the adhesiveness of the surface of the photosensitive layer 16 in contact with the peeling adhesive layer 18 is lowered by the curing of the photosensitive layer 16, the photosensitive layer 16 is cured so that the space between the photosensitive layer 16 and the peeling adhesive layer 18 is reduced. The adhesive strength of the will be reduced.

  In addition, the method for obtaining the configuration of (1) and the method for obtaining the configuration of (2) are just examples, and these methods are not limited to the above examples. Other configurations can be applied as long as they have the same function.

  The structure that satisfies the above (C) is not particularly limited. For example, as exemplified as a method for obtaining the above structure (1), the material constituting the support adhesive layer 14 is used. For example, a material compatible with the curing component of the photosensitive layer 16 can be used. At this time, a material in which the adhesive force (bonding force) between the support adhesive layer 14 after curing and the photosensitive layer 16 is higher than the breaking strength of the cured portion after the photosensitive layer 16 is cured, It is good to use for the material which comprises the support body adhesive layer 14. FIG.

  In addition, the configuration satisfying the above (D) is not particularly limited. For example, as exemplified as a method for obtaining the above configuration (2), the material constituting the peeling adhesive layer 18 is sensitive to the material. Examples thereof include using a material that is incompatible with the cured component of the layer 16 or a material that is relatively incompatible. At this time, a material whose adhesive force (bonding force) between the peeled adhesive layer 18 after curing and the photosensitive layer 16 is lower than the breaking strength of the cured portion after the photosensitive layer 16 is cured is peeled off. It may be used as a material for forming the adhesive layer 18.

  The peeling force between the uncured portion of the photosensitive layer 16 and the support adhesive layer 14 prevents the uncured portion from remaining on the support adhesive layer 14 at the time of release development, and the uncured portion and the support adhesive layer 14 It is preferable that it is smaller than the fracture strength of the uncured part from the viewpoint of reliably peeling between the two. Furthermore, it is preferable that the peeling force between the uncured portion of the photosensitive layer 16 and the peeling adhesive layer 18 is greater than the breaking strength of the uncured portion of the photosensitive layer 16. Moreover, it is preferable that the peeling force between the cured portion after the photosensitive layer 16 is cured and the release adhesive layer 18 is smaller than the breaking strength of the uncured portion of the photosensitive layer 16.

  The peeling force between the uncured portion of the photosensitive layer 16 and the support adhesive layer 14 is such that the uncured portion hardly remains on the support adhesive layer 14 during the peeling development, and the uncured portion and the support adhesive layer 14 It is preferable that it is 4.0 N / width 3 cm or less from a viewpoint of peeling reliably between. More preferably, it is 2.0 N / width 3 cm or less, and still more preferably 1.0 N / width 3 cm or less. On the other hand, from the viewpoint of handling properties during work, it is preferably 0.1 N / width 3 cm or more. More preferably, it is 0.3 N / width 3 cm or more.

  The peeling force between the cured portion after curing the photosensitive layer 16 and the support adhesive layer 14 is 5 from the viewpoint that the cured portion is not peeled off at the time of development and is surely left on the support adhesive layer 14. 0.0 N / width 3 cm or more is preferable. More preferably, it is 10 N / width 3 cm or more, and further preferably 20 N / width 3 cm or more. When a material compatible with the cured component of the photosensitive layer 16 is used as the material constituting the support adhesive layer 14, the peeling force between the cured portion and the support adhesive layer 14 can be easily set to 20 N / width 3 cm or more.

  The peeling force between the uncured portion of the photosensitive layer 16 and the peeling adhesive layer 18 is such that the uncured portion is reliably attached to the peeling adhesive layer 18 and peeled off from the support adhesive layer 14 at the time of release development. It is preferably 1.0 N / width 3 cm or more. More preferably, it is 2.0 N / width 3 cm or more, and still more preferably 4.0 N / width 3 cm or more.

  The peeling force between the cured portion after curing the photosensitive layer 16 and the release adhesive layer 18 is ensured between the cured portion and the release adhesive layer 18 because the cured portion does not adhere to the release adhesive layer 18 during release development. In view of being peeled off, it is preferably 20 N / width 3 cm or less. More preferably, it is 10 N / width 3 cm or less, and further preferably 5.0 N / width 3 cm or less. When a material that is not compatible with the cured component of the photosensitive layer 16 or a material that is relatively incompatible with the material constituting the release adhesive layer 18 is used, the release force between the cured portion and the release adhesive layer 18 is set to 5. It is easy to set to 0 N / width 3 cm or less.

The peeling force can be measured by, for example, a T-type peeling test, a 180 ° peeling test, a 90 ° peeling test, or the like in accordance with a method defined in JIS K 6854. In addition, since the said peeling force is a value when the width | variety of the test body at the time of measuring peeling force is 3 cm, the unit is N / width 3cm. In measuring the peeling force, the width of the test body can be changed as appropriate. Similarly, the breaking strength of the photosensitive layer 16 can be measured by a T-type peel test, a 180 ° peel test, a 90 ° peel test, or the like in accordance with a method defined in JIS K 6854. In addition, the peeling force and breaking strength between the cured portions after the photosensitive layer 16 is cured shall be measured when the photosensitive layer 16 is cured by UV irradiation with a light amount of UVA 19 J / cm ^2. Can do.

  Here, examples of the material constituting the photosensitive layer 16 include those containing a photopolymerizable monomer as the curable component. In addition to the photopolymerizable monomer, for example, a binder polymer, a photopolymerization initiator, and the like can be blended with the material constituting the photosensitive layer 16. The material constituting the photosensitive layer 16 may further contain various additives blended in the photosensitive layer 16. Examples of such additives include surfactants, plasticizers, thermal polymerization inhibitors (stabilizers), ultraviolet absorbers, dyes, pigments, antifoaming agents, and fragrances. The photopolymerizable monomer includes a photopolymerizable oligomer.

  Examples of the photopolymerizable monomer (oligomer, hereinafter the same) include ethylenically unsaturated compounds. Examples of the ethylenically unsaturated compound include (meth) acrylic monomers and (meth) acrylic modified polymers. Examples of the (meth) acryl-modified polymer include (meth) acryl-modified butadiene rubber and (meth) acryl-modified nitrile rubber. These may be used alone or in combination of two or more.

  Examples of the (meth) acrylic monomer include alkyl (meth) acrylic monomers, ethylene glycol (meth) acrylic monomers, glycerin (meth) acrylic monomers, urethane (meth) acrylic monomers, and the like. Among these, an alkyl (meth) acrylic monomer, a (meth) acrylic monomer having an aromatic ring, and the like are preferable because the transition to the support adhesive layer 14 is more likely to proceed. On the other hand, ethylene glycol-based (meth) acrylic monomers, glycerin-based (meth) acrylic monomers, and the like can be mentioned as those that are relatively difficult to move to the support adhesive layer 14.

  More specifically, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, isoamyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) Alkyl (meth) acrylates such as acrylate / stearyl (meth) acrylate, cycloalkyl (meth) acrylates such as cyclohexyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxy (Meth) acrylates having a hydroxyl group such as butyl (meth) acrylate, 3-chloro-2-hydroxypropyl (meth) acrylate, β-hydroxy-β ′-(meth) acryloyloxyethyl phthalate, Alkoxyalkyl (meth) acrylates such as roloethyl (meth) acrylate and chloropropyl (meth) acrylate, and alkoxyalkyl (meth) acrylates such as methoxyethyl (meth) acrylate, ethoxyethyl (meth) acrylate and butoxyethyl (meth) acrylate , Phenoxyalkyl (meth) acrylates such as phenoxyethyl acrylate, nonylphenoxyethyl (meth) acrylate, and alkoxyalkylenes such as ethoxydiethylene glycol (meth) acrylate, methoxytriethylene glycol (meth) acrylate, and methoxydipropylene glycol (meth) acrylate Glycol (meth) acrylate, 2,2-dimethylaminoethyl (meth) acrylate, 2,2-diethylaminoethyl (meth) ) Alkyldiol di such as acrylate, 2-hydroxyethyl (meth) acrylate, 3-chloro-2-hydroxypropyl (meth) acrylate, 1,9-nonanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, etc. Polyethylene glycol di (meth) acrylates such as (meth) acrylate and diethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylates such as dipropylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol Tris (meth) acrylate, pentaerythritol tetra (meth) acrylate, glycerol tri (meth) acrylate, and ethylene glycol diglycidyl ether Of polyhydric (meth) acrylates, glycidyl (meth) acrylates and other unsaturated epoxy compounds obtained by addition reaction of ethylenically unsaturated bonds such as boronic acid and unsaturated alcohol with active hydrogen compounds and carboxylic acids and amines Examples thereof include polyvalent (meth) acrylamides such as polyvalent (meth) acrylates and methylenebis (meth) acrylamide obtained by addition reaction of such compounds having active hydrogen, and polyvalent vinyl compounds such as divinylbenzene.

  Although it does not specifically limit as content of a photopolymerizable monomer, Preferably it exists in the range of 10-80 mass%, More preferably, it exists in the range of 20-50 mass%. When the content of the photopolymerizable monomer is 10% by mass or more, there is no shortage of crosslinking density, and good image reproducibility and ink resistance can be easily obtained. On the other hand, when the content of the photopolymerizable monomer is 80% by mass or less, the relief is not brittle and the flexibility that is a feature of the flexographic printing plate is easily secured.

  Examples of the binder polymer include materials containing rubber. By including rubber, the elasticity of the flexographic printing plate is increased, so that an effect such as easy printing on various substrates can be expected. The binder polymer may contain an aqueous dispersion latex in addition to the rubber. The water-dispersed latex is a polymer particle dispersed in water as a dispersoid. A polymer is obtained by removing water from the water-dispersed latex. By using the water-dispersed latex, even if a part of the photosensitive layer remains after the peeling development, it can be washed away with water.

  Specific examples of rubber include butadiene rubber (BR), nitrile rubber (NBR), acrylic rubber, epichlorohydrin rubber, urethane rubber, isoprene rubber, styrene isoprene rubber, styrene butadiene rubber, ethylene-propylene copolymer, and chlorination. Examples thereof include polyethylene, styrene-butadiene-styrene (SBS), and styrene-isoprene-styrene (SIS). Further, among these rubbers, a part having an unsaturated bond or a complete hydrogenated product can be exemplified. These may be used alone or in combination of two or more.

  Specific examples of the water-dispersed latex include polybutadiene latex, natural rubber latex, styrene-butadiene copolymer latex, acrylonitrile-butadiene copolymer latex, polychloroprene latex, polyisoprene latex, polyurethane latex, and methyl methacrylate-butadiene copolymer. Water-dispersed latex polymers such as polymer latex, vinylpyridine polymer latex, butyl polymer latex, thiocol polymer latex, and acrylate polymer latex, and other components such as acrylic acid and methacrylic acid are copolymerized with these polymers. And the resulting polymer. These may be used alone or in combination of two or more.

  The photopolymerization initiator is not particularly limited as long as it initiates photopolymerization of the photopolymerizable monomer. For example, alkylphenones, acetophenones, benzoin ethers, benzophenones, thioxanthones, anthraquinones, benzyls, Examples thereof include photopolymerization initiators such as biacetyls. Specific examples include benzyl dimethyl ketal, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, methyl-O-benzoylbenzoate, 1-hydroxycyclohexyl phenyl ketone, and the like.

  Although it does not specifically limit as content of a photoinitiator, Preferably it exists in the range of 0.3-10 mass%, More preferably, it exists in the range of 0.5-3 mass%. When the content of the photopolymerization initiator is 0.3% by mass or more, the photopolymerization reaction of the photopolymerizable monomer occurs sufficiently and a good image can be formed. On the other hand, if the content of the photopolymerization initiator is 10% by mass or less, the sensitivity is not too high, so that the exposure time can be easily adjusted.

  The thickness of the photosensitive layer 16 is not particularly limited, but is preferably within a range of 0.01 to 3 mm. If the thickness of the photosensitive layer 16 is 0.01 mm or more, a sufficient relief depth can be secured. On the other hand, if the thickness of the photosensitive layer 16 is 3 mm or less, the weight of the flexographic printing plate precursor 10 can be suppressed, the image reproducibility and the peel development property are excellent, and it can be practically used as a printing plate. .

  As a material constituting the support adhesive layer 14, for the purpose of obtaining the above configuration (1), for example, a material compatible with the curing component of the photosensitive layer 16 is preferably used. it can. Thereby, since a part of curable component becomes easy to transfer to the support body adhesive layer 14, the adhesive force (bonding force) between the support body adhesive layer 14 and the photosensitive layer 16 can be improved after hardening. As a result, by curing the photosensitive layer 16, the adhesive force between the photosensitive layer 16 and the support adhesive layer 14 is increased so that the cured portion of the photosensitive layer 16 is cured and between the support adhesive layer 14. Can be made higher than the adhesive force between the uncured portion of the photosensitive layer 16 and the support adhesive layer 14.

  The material compatible with the curing component of the photosensitive layer 16 is not particularly limited, but preferably includes, for example, polyester. By including polyester in the support adhesive layer 14, compatibility between the material of the support adhesive layer 14 and the curable component contained in the photosensitive layer 16 is improved, and a part of the curable component is supported by the support adhesive layer 14. By shifting to, it is presumed that the adhesive force (bonding force) between the support adhesive layer 14 and the photosensitive layer 16 is enhanced after exposure. In addition, this makes it easy to satisfy the above (C).

  When polyester is contained in the support adhesive layer 14, if the material constituting the photosensitive layer 16 contains a (meth) acrylic monomer as a curable component, the uncured portion of the photosensitive layer 16 and the support adhesive layer 14 It is easy to make the peeling force between 1.0 N / width 3 cm or less, and the peeling force between the cured portion after the photosensitive layer 16 is cured and the support adhesive layer 14 easy to make 20 N / width 3 cm or more.

  When polyester is contained in the support adhesive layer 14, it is preferable to further contain a curing agent. Although it does not specifically limit as a hardening | curing agent, An isocyanate compound, an epoxy compound, methylol melamine etc. can be mentioned. Moreover, you may use a hardening accelerator together as needed. As the curing agent, an isocyanate compound is particularly preferable. By including an isocyanate compound, the adhesive component does not flow out from the support adhesive layer 14 even when it comes into contact with ink during flexographic printing by crosslinking with a functional group capable of reacting with the self-crosslinking of the isocyanate compound or polyester. Can be. Therefore, even when flexographic printing is repeatedly performed, the function as an adhesive layer is maintained over a long period of time.

  The polyester is preferably an adhesive component of the support adhesive layer 14. The polyester is composed of a polycondensate of a polyvalent carboxylic acid and a polyol. The polyvalent carboxylic acid forming the polyester includes an aromatic polyvalent carboxylic acid having an aromatic skeleton, an aliphatic polyvalent carboxylic acid having an aliphatic skeleton, both an aromatic polyvalent carboxylic acid and an aliphatic polyvalent carboxylic acid. The polyhydric carboxylic acid containing can be mentioned. As the polyvalent carboxylic acid, dicarboxylic acid or tricarboxylic acid is preferably used. As the polyol forming the polyester, diol, triol, or the like is preferably used. The polyester may be crystalline or amorphous.

  Although it does not specifically limit as polyester, From a viewpoint of being excellent in compatibility with the sclerosing | hardenable component of the photosensitive layer 16, it is preferable that it is an amorphous polyester. From the same viewpoint, it is preferable that Tg is relatively low. Moreover, it is preferable that the aromatic component derived from aromatic polyhydric carboxylic acid is included from a viewpoint of being excellent in intensity | strength. Examples of such polyesters include polyester polyols obtained by reacting polyvalent carboxylic acids including aromatic polyvalent carboxylic acids and aliphatic polyvalent carboxylic acids with polyol compounds.

  The Tg of the polyester is not particularly limited, but is preferably 70 ° C. or lower from the viewpoint of excellent flexibility and adhesiveness. More preferably, it is 50 degrees C or less. Tg is a value measured according to JIS K7121 “Plastic transition temperature measurement method”. Further, the number average molecular weight of the polyester is not particularly limited, but is preferably 3000 to 30000 from the viewpoint of excellent strength and adhesiveness. More preferably, it is 10000-20000. In addition, the number average molecular weight of polyester can be made into the molecular weight represented by polystyrene conversion by gel permeation chromatography (GPC).

  Specific examples of the aromatic carboxylic acid include terephthalic acid, isophthalic acid, bis (p-carboxyphenyl) methane, oxybis (benzoic acid), ethylene-1,2-bis (p-oxybenzoic acid), Examples include 1,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, phenanthrenedicarboxylic acid, anthracene dicarboxylic acid, and 4,4′-sulfonyldibenzoic acid. These can be used alone or in combination of two or more. Among these, terephthalic acid, isophthalic acid, and a mixture of terephthalic acid and isophthalic acid are preferable from the viewpoint of more excellent adhesiveness.

  As the aliphatic dicarboxylic acid, those having 6 to 12 carbon atoms are particularly preferable. More specifically, for example, adipic acid, suberic acid, azelaic acid, sebacic acid, undecanedicarboxylic acid, dodecanedicarboxylic acid and the like can be mentioned. These can be used alone or in combination of two or more. Among these, adipic acid, sebacic acid, and a mixture of adipic acid and sebacic acid are preferable from the viewpoint of more excellent adhesiveness.

  Specific examples of the polyol compound include low molecular weight polyols such as ethylene glycol, propylene glycol, butylene glycol, glycerin, hexanetriol, trimethylolpropane, and neopentyl glycol, polytetramethylene glycol, polyethylene glycol, polypropylene glycol, Examples thereof include polyether polyols such as polyoxypropylene glycol and polyoxybutylene glycol, polyolefin polyols such as polybutadiene polyol and polyisoprene polyol, adipate polyols, and lactone polyols. These can be used alone or in combination of two or more. Among these, ethylene glycol, propylene glycol, and neopentyl glycol are preferable from the viewpoint of more excellent adhesiveness.

  Although it does not specifically limit as an isocyanate compound, The polyisocyanate compound which has 2 or more of isocyanate groups is preferable. Examples of the polyisocyanate compound include alicyclic, aromatic and aliphatic diisocyanate compounds. Further, as the polyisocyanate compound, a tri- or higher functional polyisocyanate compound such as an adduct, an isocyanurate, or a burette can also be used.

  Examples of the alicyclic diisocyanate include cyclohexane-1,4-diisocyanate, isophorone diisocyanate, norbornene diisocyanate, dicyclohexylmethane-4,4′-diisocyanate, 1,3-bis (isocyanatemethyl) cyclohexane, methylcyclohexane diisocyanate, and the like. be able to.

  As aromatic diisocyanate, 1,5-naphthylene diisocyanate, 4,4′-diphenylmethane diisocyanate, 4,4′-diphenyldimethylmethane diisocyanate, 4,4′-dibenzyl isocyanate, dialkyldiphenylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanate, Examples include 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, tolylene diisocyanate, xylylene diisocyanate, m-tetramethylxylylene diisocyanate, and the like.

  Aliphatic diisocyanates include butane-1,4-diisocyanate, hexamethylene diisocyanate, isopropylene diisocyanate, methylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, lysine diisocyanate and dimer acid carboxyl groups. Examples thereof include dimerized isocyanate converted to a group.

  On the other hand, when it is not intended to obtain the configuration (1), the material constituting the support adhesive layer 14 is within the range satisfying the above (A) to (D). Any known adhesive can be used as long as it can bond the photosensitive layer 16 to the photosensitive layer 16.

  Although it does not specifically limit as thickness of the support body adhesive layer 14, It is preferable to exist in the range of 1-100 micrometers. More preferably, it exists in the range of 5-50 micrometers.

  The material constituting the peeling adhesive layer 18 is not compatible with the curing component of the photosensitive layer 16 in the material constituting the peeling adhesive layer 18, for example, when the purpose is to obtain the configuration (2) above. Examples thereof include using a material or a material that is relatively incompatible. This prevents a part of the curable component from moving to the peeling adhesive layer 18. If it does so, the adhesive force (bonding force) between the peeling adhesive layer 18 and the photosensitive layer 16 will not increase after hardening. At this time, since the adhesiveness of the surface of the photosensitive layer 16 in contact with the peeling adhesive layer 18 is lowered by the curing of the photosensitive layer 16, the photosensitive layer 16 is cured so that the space between the photosensitive layer 16 and the peeling adhesive layer 18 is reduced. The adhesive strength of the will be reduced. Moreover, it is easy to satisfy said (D) by this.

  A material that is incompatible with the curing component of the photosensitive layer 16 or a material that is relatively incompatible is not particularly limited, and examples thereof include polyvinyl alcohol, polyamide, polyvinyl pyrrolidone, and vinyl pyrrolidone copolymer. Examples thereof include materials. These may be contained independently and 2 or more types may be contained. When the release adhesive layer 18 contains polyvinyl alcohol, polyamide, polyvinyl pyrrolidone, vinyl pyrrolidone copolymer, or a mixture of two or more of these, the material of the release adhesive layer 18 and the curable component contained in the photosensitive layer 16 It is inferred that the compatibility of the curable component and the curable component becomes difficult to migrate to the support adhesive layer 14.

  When the release adhesive layer 18 contains polyvinyl alcohol, polyamide, polyvinyl pyrrolidone, vinyl pyrrolidone copolymer, or a mixture of two or more thereof, the material constituting the photosensitive layer 16 is (meth) as a curable component. When the acrylic monomer is included, the peeling force between the uncured portion of the photosensitive layer 16 and the peeling adhesive layer 18 is easily set to 1.0 N / width 3 cm or more, and the cured portion after the photosensitive layer 16 is cured is peeled off. It is easy to make the peeling force between the adhesive layer 18 5.0 N / width 3 cm or less.

  Polyvinyl alcohol preferably has a low saponification degree from the viewpoint of excellent adhesion to the uncured portion of the photosensitive layer 16. Specifically, the saponification degree is preferably 90 mol% or less. More preferably, it is 50 mol% or less. On the other hand, the degree of saponification is preferably 20 mol% or more from the viewpoint of suppressing the migration of the curing component of the photosensitive layer 16. More preferably, it is 30 mol% or more.

  Examples of the polyamide include aromatic polyamide and aliphatic polyamide. Although not particularly limited, specifically, for example, polyamide 6 (PA6), polyamide 66 (PA66), polyamide 99 (PA99), polyamide 1010 (PA1010), polyamide 610 (PA610), polyamide 612 (PA612) ), Polyamide 11 (PA11), polyamide 912 (PA912), polyamide 12 (PA12), copolymer of polyamide 6 and polyamide 66 (PA6 / 66), copolymer of polyamide 6 and polyamide 12 (PA6 / 12) And the like. These may be used alone or in combination of two or more. Among these, the alcohol-soluble modified type is preferable from the viewpoint of easily suppressing the migration of the curing component of the photosensitive layer 16.

  The vinyl pyrrolidone copolymer is not particularly limited, but vinyl pyrrolidone-vinyl acetate copolymer, vinyl pyrrolidone-styrene copolymer, vinyl pyrrolidone-maleic anhydride copolymer, vinyl pyrrolidone-quaternization. Examples thereof include a dimethylaminoethyl methacrylate copolymer and a vinylpyrrolidone-alkylaminoacrylate copolymer. These may be used alone or in combination of two or more. Among these, a vinylpyrrolidone-vinyl acetate copolymer is preferable from the viewpoint of excellent adhesiveness with the uncured portion of the photosensitive layer 16 and releasability from the cured portion of the photosensitive layer 16. The vinyl pyrrolidone-vinyl acetate copolymer has a composition ratio of 30/70 to 30% from the viewpoint of excellent adhesion to the uncured portion of the photosensitive layer 16 and easy suppression of the migration of the cured component of the photosensitive layer 16. It is preferable to be within the range of 70/30.

  Examples of the mixture containing polyvinyl pyrrolidone include a mixture of polyvinyl alcohol and polyvinyl pyrrolidone, a mixture of polyamide and polyvinyl pyrrolidone, and the like. Among these, a mixture of polyvinyl alcohol and polyvinyl pyrrolidone is preferable from the viewpoint of excellent adhesion to the uncured portion of the photosensitive layer 16 and excellent peelability from the cured portion of the photosensitive layer 16. In this case, the saponification degree of polyvinyl alcohol is preferably in the range of 50 to 90 mol%. More preferably, it exists in the range of 70-90 mol%. When the degree of saponification is within this range, the compatibility with polyvinylpyrrolidone is improved, which is preferable.

  When the polymer component contained in the release adhesive layer 18 is polyvinyl pyrrolidone alone, it tends to be slightly difficult to peel off after the photosensitive layer 16 is cured. Therefore, when a compound containing vinylpyrrolidone is used for the release adhesive layer 18, it is preferable to use a mixture with a polymer component other than polyvinylpyrrolidone or a vinylpyrrolidone copolymer. Thereby, it can peel easily.

  On the other hand, when it is not intended to obtain the configuration of (2) above, the material constituting the peelable adhesive layer 18 is the cover film 20 within the range satisfying the above (A) to (D). Any known adhesive can be used as long as it can adhere to the photosensitive layer 16.

  Although it does not specifically limit as thickness of the peeling adhesive layer 18, It is preferable to exist in the range of 1-100 micrometers. More preferably, it exists in the range of 5-30 micrometers. If the thickness of the peeling adhesive layer 18 is 1 μm or more, adhesion can be secured. On the other hand, when the thickness of the peeling adhesive layer 18 is 100 μm or less, the distance to the photosensitive layer 16 is short, and UV light is irradiated linearly on the photosensitive layer 16, so that the image reproducibility is excellent.

  Although the material which comprises the support body 12 is not specifically limited, Resin etc. are preferable. The support 12 may be transparent or not transparent because it is not necessary to back-expose the photosensitive layer 16. Transparent means that light is transmitted to the extent that exposure is possible. The support 12 is preferably a polyester film such as a PET film because of excellent dimensional stability. The thickness of the support 12 is preferably in the range of 50 to 300 μm from the viewpoint of obtaining sufficient strength to support the laminated layer such as the photosensitive layer 16. More preferably, it exists in the range of 50-200 micrometers.

  Although the material which comprises the cover film 20 is not specifically limited, Resin etc. are preferable. The cover film 20 is preferably transparent when the photosensitive layer 16 is exposed from the cover film 20 side with the cover film 20 left, but is sensitive from the release adhesive layer 18 side with the cover film 20 peeled off. When the layer 16 is exposed, it may not be transparent.

  Specific examples of the cover film 20 include a polyester film such as a PET film, a polycarbonate film, a polyamide film, a polyolefin film such as a polyethylene film and a polypropylene film, and a polystyrene film. The thickness of the cover film 20 is preferably in the range of 25 to 200 μm from the viewpoints of excellent handleability and excellent function of protecting from scratches. More preferably, it exists in the range of 50-150 micrometers.

  Here, the flexographic printing plate precursor 10 is composed of a laminate in which a support 12, a support adhesive layer 14, a photosensitive layer 16, a peeling adhesive layer 18 and a cover film 20 are laminated in this order. The flexographic printing plate precursor may further include an infrared ablation layer. FIG. 2 shows a flexographic printing plate precursor 30 according to another embodiment.

  As shown in FIG. 2, the flexographic printing plate precursor 30 according to another embodiment is provided with an infrared ablation layer 22 between the release adhesive layer 18 and the cover film 20, and the support 12 and the support adhesive layer. 14, the photosensitive layer 16, the peeling adhesive layer 18, the infrared ablation layer 22, and the cover film 20 are laminated in this order. Since the flexographic printing plate precursor 30 according to another embodiment is the same as the flexographic printing plate precursor 10 except for the infrared ablation layer 22, the description thereof is omitted.

  The infrared ablation layer 22 is a portion serving as a mask that covers the surface of the photosensitive layer 16. The infrared ablation layer 22 is a part that can be removed by an infrared laser, and a part that is not removed shields (absorbs) ultraviolet light and masks the photosensitive layer 16 from being irradiated with ultraviolet light. From the viewpoint of shielding ultraviolet light, the thickness of the infrared ablation layer 22 is preferably in the range of 0.1 to 5 μm. The infrared ablation layer 22 is composed of a composition containing a binder polymer and an infrared absorbing material.

  The binder polymer of the infrared ablation layer 22 is not particularly limited, but includes acrylic resin, acrylonitrile-butadiene copolymer rubber (NBR), styrene-butadiene copolymer rubber (SBR), butadiene rubber (BR), and the like. Can be mentioned. These may be used alone or in combination of two or more.

  The infrared absorbing substance is not particularly limited as long as it can absorb infrared rays and convert it into heat. Specific examples of infrared absorbing substances include black pigments such as carbon black, aniline black, and cyanine black, phthalocyanine, naphthalocyanine green pigments, rhodamine dyes, naphthoquinone dyes, polymethine dyes, diimonium salts, azoimonium dyes, Chalcogen dyes, carbon graphite, iron powder, diamine metal complexes, dithiol metal complexes, phenolthiol metal complexes, mercaptophenol metal complexes, arylaluminum metal salts, crystal water-containing inorganic compounds, copper sulfate, cobalt oxide and oxidation Examples thereof include metal oxides such as tungsten, hydroxides of these metals, sulfates, bismuth, tin, tellurium, and metal powders of aluminum. Among these, carbon black, carbon graphite, and the like are preferable from the viewpoint of having an ultraviolet absorbing function.

  The content of the infrared absorbing material may be an amount that is in a range having such a sensitivity that the infrared ablation layer 22 is removed by the infrared laser beam to be used. The content of the infrared absorbing substance is preferably in the range of 0.1 to 75% by mass, more preferably in the range of 1 to 50% by mass.

  The infrared ablation layer 22 may contain various additives in addition to these components. Examples of such additives include surfactants, plasticizers, ultraviolet absorbing substances, dyes, pigments, antifoaming agents, and fragrances.

  As the ultraviolet absorbing substance, a substance having absorption in the region of 300 to 400 nm is preferable. Examples of such substances include benzotriazole compounds, triazine compounds, benzophenone compounds, carbon black, and metals or metal oxides represented by the above infrared absorbing substances.

  Next, an example of a method for producing a flexographic printing plate precursor will be described.

  In the flexographic printing plate precursor 10 according to an embodiment, a photosensitive composition for forming a photosensitive layer 16 is sandwiched between a support 12 and a cover film 20, and the thickness of the photosensitive composition becomes a predetermined thickness. Thus, it can manufacture by pressing at predetermined temperature. On the surface of the support 12 that contacts the photosensitive composition, for example, an adhesive material that forms the support adhesive layer 14 is applied in advance, and on the surface of the cover film 20 that contacts the photosensitive composition, An adhesive material for forming the peeling adhesive layer 18 is applied in advance. Thereby, between the support body 12 and the photosensitive composition, or between the photosensitive composition and the cover film 20 can be adhere | attached.

  Note that the adhesive material for forming the support adhesive layer 14 and the adhesive material for forming the peeling adhesive layer 18 may be liquid so as to be coated as described above, or may be in the form of a film, sheet, or the like. It may be solid. In the case of a solid form, each adhesive material is sandwiched between the support 12 and the photosensitive composition or between the photosensitive composition and the cover film 20 and then subjected to thermocompression bonding or the like. Can be glued.

  In a flexographic printing plate precursor 30 according to another embodiment, a photosensitive composition for forming a photosensitive layer 16 is sandwiched between a cover film 20 having an infrared ablation layer 22 formed on an inner surface and a support 12, and photosensitive. The composition can be manufactured by pressing at a predetermined temperature so that the thickness of the composition becomes a predetermined thickness. The infrared ablation layer 22 can be formed by previously applying the composition forming the infrared ablation layer 22 to the inner surface of the cover film 20. An adhesive material for forming the support adhesive layer 14 is applied in advance to the surface of the support 12 that contacts the photosensitive composition, and the surface of the infrared ablation layer 22 that contacts the photosensitive composition is previously applied. An adhesive material for forming the release adhesive layer 18 can be applied. Alternatively, the respective adhesive materials are sandwiched between the support 12 and the photosensitive composition or between the photosensitive composition and the infrared ablation layer 22 and bonded together by thermocompression bonding or the like. Can do.

  The photosensitive composition for forming the photosensitive layer 16 can be prepared by kneading the above-described components and dehydrating as necessary. When water-dispersed latex is included, it can be prepared by previously dehydrating the water-dispersed latex and then kneading the polymer obtained from the water-dispersed latex and other components. Examples of the kneader used at the time of kneading include a twin screw extruder, a single screw extruder, a kneader, and a Banbury mixer.

  The infrared ablation layer 22 is prepared by dissolving each component of the composition forming the infrared ablation layer 22 in a solvent to prepare a coating liquid, coating the cover film 20 and then drying to remove the solvent. Can be formed. Solvents include ketone solvents such as methyl isobutyl ketone and methyl ethyl ketone, aromatic solvents such as toluene and xylene, alcohol solvents such as methanol and isopropyl alcohol, ester solvents such as methyl acetate, and glycol solvents. And aprotic polar solvents such as N-methylpyrrolidone. These may be used singly or in combination of two or more.

  Next, an example of a method for producing a flexographic printing plate will be described. FIGS. 3 and 4 show an example of a manufacturing process of a flexographic printing plate obtained from the flexographic printing plate precursor shown in FIGS. FIG. 3A shows an exposure process, and FIG. 3B shows a development process. 4A shows a drawing process, FIG. 4B shows an exposure process, and FIG. 4C shows a development process.

  The flexographic printing plate is obtained by forming a relief image on the photosensitive layer 16 of the flexographic printing plate precursor. In the flexographic printing plate, basically, an exposure process for irradiating the photosensitive layer 16 of the flexographic printing plate precursor with light to form a cured portion that is a source of a relief image on the photosensitive layer 16, and an uncured portion of the photosensitive layer 16 are formed. And a developing step for forming a relief image formed of a cured portion by removing.

  As shown in FIG. 3 (a), in the flexographic printing plate precursor 10 according to an embodiment, in the exposure process, on the cover film 20 or on the release adhesive layer 18 that appears after the cover film 20 is peeled off. Then, a negative film 24 on which a negative pattern is formed in advance is placed, and light (ultraviolet light or the like) is irradiated to the photosensitive layer 16 through the negative film 24 (from above the negative film 24). The negative film 24 functions as a desired image mask, and the portion of the photosensitive layer 16 exposed to light is cured, and the portion not exposed to light is not cured. Thereby, the photosensitive layer 16 is formed with a cured portion 16a that is the basis of the relief image and an uncured portion 16b that is peeled off in the development process.

  Next, as shown in FIG. 3B, the peeling adhesive layer 18 or the peeling adhesive layer 18 is peeled together with the cover film 20 in the development process. At this time, the peel force between the uncured portion 16b of the photosensitive layer 16 and the support adhesive layer 14 is smaller than the peel force between the uncured portion 16b of the photosensitive layer 16 and the peel adhesive layer 18, and the photosensitive layer Since the peeling force between the cured part 16a after curing 16 and the support adhesive layer 14 is larger than the peeling force between the cured part 16a after curing the photosensitive layer 16 and the peeling adhesive layer 18, The uncured portion 16 b of the photosensitive layer 16 is peeled from the support adhesive layer 14, and the cured portion 16 a of the photosensitive layer 16 is peeled from the release adhesive layer 18. As a result, while leaving the cured portion 16a of the photosensitive layer 16 on the support adhesive layer 14, only the uncured portion 16b is peeled off from the support adhesive layer 14, and a relief image composed of the cured portion 16a is formed on the support 12. To form.

  After the peel development, development using a developer can be performed as necessary. The development using the developer can be performed by washing out the remaining uncured portion 16b using, for example, a spray type developing device or a brush type washing machine. Even if development using a developer is performed, the amount of waste liquid is reduced as compared with the case of only development using a developer because the uncured portion 16b of the photosensitive layer 16 is removed by the above-described peeling development. Can be reduced.

  As the developer, for example, an aqueous developer can be used. The aqueous developer is composed of water to which a surfactant or a pH adjuster is added as necessary. In this case, the photosensitive composition for forming the photosensitive layer 16 preferably contains a water-dispersed latex so that it can be developed with water. When developing using a developing solution, you may implement the drying process which dries a flexographic printing plate as needed.

  Next, if necessary, a post-exposure step of irradiating the entire flexographic printing plate material with light again may be performed.

  In the exposure step and the post-exposure step, for example, ultraviolet rays can be irradiated by using a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a metal halide lamp, a xenon lamp, a carbon arc lamp, a chemical lamp, or the like that can irradiate light having a wavelength of 300 to 400 nm.

  On the other hand, in the flexographic printing plate precursor 30 according to another embodiment, a drawing process for producing a negative pattern is performed before the exposure process. Specifically, as shown in FIG. 4A, the cover film 20 is peeled to expose the infrared ablation layer 22, and the infrared ablation layer 22 is irradiated with an infrared laser so that a predetermined portion of the infrared ablation layer 22 is exposed. By removing, a desired negative pattern is produced. The exposure process (FIG. 4B) and the development process (FIG. 4C) of the flexographic printing plate precursor 30 according to another embodiment are the exposure process (FIG. 4) of the flexographic printing plate precursor 10 according to the embodiment. 3 (a)) and the developing step (FIG. 3B), the description thereof is omitted.

  Examples of infrared lasers include solid lasers such as ruby laser, alexandrite laser, perovskite laser, Nd-YAG laser, and emerald glass laser, semiconductor lasers using semiconductors such as InGaAsP, InGaAs, and GaAsAl, and dye lasers such as rhodamine dyes. be able to.

  Here, in any of the flexographic printing plate precursors 10 and 30, as shown in the above (C), the peeling force between the cured portion 16 a after curing the photosensitive layer 16 and the support adhesive layer 14 is photosensitive. In the cured portion 16a of the photosensitive layer 16, the cured portion 16a and the support of the photosensitive layer 16 are destroyed before the cured portion 16a is destroyed because the strength is higher than the breaking strength of the cured portion 16a after the layer 16 is cured. The adhesive layer 14 is not peeled off, and the adhesive strength between them is excellent. That is, since the adhesiveness between the cured portion 16a after curing of the photosensitive layer 16 and the support 12 is sufficiently secured, the cured layer as a base on the support adhesive layer 14 side of the photosensitive layer 16 by back exposure. May not be formed. Since the back exposure is not required in this way, the relief depth of the flexographic printing plate can be increased by the amount that the base is not formed, so that the image reproducibility is excellent. In addition, since the foundation is not formed, the work process can be reduced.

  When the printing plate precursor according to the present invention is used, a negative film 24 (an image on which an image has already been formed) is adhered on the photosensitive layer 16 (specifically, on the peeling adhesive layer 18 or the cover film 20). It may be a so-called analog printing plate precursor, or a so-called CTP in which the infrared ablation layer 22 is in close contact with the photosensitive layer 16 (specifically, on the peeling adhesive layer 18 or the cover film 20). It may be a printing plate precursor of a LAM (Laser Abrasion Mask) system included in the (Computer to plate) system.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited thereto.

<Preparation of photosensitive layer composition>
45.5 parts by mass of water-dispersed latex (25 parts by mass of polymer as solid content), 15 parts by mass of acrylic modified liquid BR, and 5 parts by mass of acrylic monomer were mixed and heated for 2 hours at 120 ° C. Water was evaporated to obtain a mixture of a polymer obtained from the water-dispersed latex and a photopolymerizable monomer. This mixture, BR <1> 15 parts by mass, BR <2> 15 parts by mass, surfactant 2 parts by mass, and plasticizer 15 parts by mass were kneaded in a kneader for 45 minutes. Thereafter, 0.2 parts by mass of a thermal polymerization inhibitor, 1 part by mass of a photopolymerization initiator, and 0.03 part by mass of an ultraviolet absorber are added into a kneader, and kneaded for 5 minutes to obtain a photosensitive layer composition. Was prepared.

<Preparation of adhesive material for support adhesive layer>
100 parts by mass of polyester and 2 parts by mass of a curing agent (HDI (hexamethylene diisocyanate) polyisocyanate) are dissolved and mixed with a 1: 1 mixed solvent of toluene: methylethylketone to obtain an adhesive material for a support adhesive layer having a solid content of 30%. Prepared.

Example 1
<Preparation of adhesive material for release adhesive layer>
Polyvinyl alcohol <1> was dissolved and mixed in a pure water: methanol = 1: 1 mixed solution to prepare an adhesive material for a peelable adhesive layer having a solid content of 20% by mass.

<Preparation of flexographic printing plate precursor>
An adhesive material for a support adhesive layer is applied to one side of a 125 μm thick PET film (support) so that the thickness after drying is 20 μm, dried at 120 ° C. for 10 minutes, and then a 50 μm thick PET film. The adhesive material for the release adhesive layer is applied to one side of the (cover film) so that the thickness after drying is 30 μm, and dried at 120 ° C. for 10 minutes, all with the surface coated with the adhesive material facing inside Adhering the support and support by sandwiching the photosensitive layer composition between the support and the cover film and pressing with a press heated to 120 ° C. so that the thickness of the photosensitive layer composition is 1.0 mm. A flexographic printing plate precursor of Example 1 was prepared in which a layer, a photosensitive layer, a release adhesive layer, and a cover film were laminated in this order.

(Example 2)
A flexographic printing plate precursor of Example 2 was produced in the same manner as in Example 1 except that polyamide was used instead of polyvinyl alcohol <1> in the adhesive material for the release adhesive layer.

(Example 3)
The same procedure as in Example 1 was carried out except that a 1: 1 mixture of the polyvinyl alcohol <1> solution used in Example 1 and the polyamide solution used in Example 2 was used as the adhesive material for the release adhesive layer. The flexographic printing plate precursor of Example 3 was prepared.

Example 4
In place of the cover film in Example 1, a flexographic printing plate precursor of Example 4 was prepared in the same manner as in Example 1 except that a 50 μm thick PET film having a release treatment on one side was used as the cover film. Produced.

(Example 6)
A flexographic printing plate precursor of Example 6 was produced in the same manner as in Example 1 except that a vinylpyrrolidone-vinyl acetate copolymer was used instead of polyvinyl alcohol <1> in the adhesive material for the release adhesive layer.

(Example 7)
50 parts by mass of polyvinyl alcohol <2> and 50 parts by mass of polyvinyl pyrrolidone are dissolved and mixed in a pure water: methanol: isopropyl alcohol = 8: 1: 1 mixed solution to obtain an adhesive material for a peeling adhesive layer having a solid content of 20% by mass. Prepared. A flexographic printing plate precursor of Example 7 was produced in the same manner as in Example 1 except that the prepared adhesive material for release adhesive layer was used.

(Example 8)
A flexographic printing plate precursor of Example 8 was produced in the same manner as in Example 1 except that the curing agent was not used in the preparation of the adhesive material for the support adhesive layer.

(Comparative Example 1)
A flexographic printing plate precursor of Comparative Example 1 was produced in the same manner as in Example 1 except that the same material as that for the support adhesive layer was used as the adhesive material for the release adhesive layer.

(Comparative Example 2)
Polyvinyl butyral was dissolved in isopropyl alcohol to prepare an adhesive material for a peelable adhesive layer having a solid content of 20% by mass. A flexographic printing plate precursor of Comparative Example 2 was produced in the same manner as in Example 1 except that the prepared adhesive material for release adhesive layer was used.

(Example 5)
<Preparation of infrared ablation layer composition>
100 parts by mass of carbon black and 3 parts by mass of a plasticizer are added to 100 parts by mass of a binder polymer consisting of 75 parts by mass of acrylic resin and 25 parts by mass of NBR, and 812 parts by mass of methyl isobutyl ketone as a solvent is added and mixed by feather stirring. did. After the obtained mixed liquid was dispersed using a three-roll mill, an infrared ablation layer composition was prepared by further adding methyl isobutyl ketone so that the solid content was 15% by mass.

<Preparation of flexographic printing plate precursor>
By applying an infrared ablation layer composition with a bar coater to one side of a 125 μm thick PET film (cover film) so that the thickness of the dried coating film is 1 μm, and drying at 120 ° C. for 5 minutes. An infrared ablation layer was formed on one side of the cover film. Next, a polyvinyl alcohol solution was applied as an adhesive material for the release adhesive layer to the surface of the formed infrared ablation layer and dried at 120 ° C. for 10 minutes. Next, in the same manner as in Example 1, the photosensitive material composition was sandwiched between the cover film on which the infrared ablation layer was formed and the support with the adhesive material on the inside, and pressed, thereby supporting and supporting the support. A flexographic printing plate precursor of Example 5 was prepared in which a layer, a photosensitive layer, a release adhesive layer, an infrared ablation layer, and a cover film were laminated in this order.

Below, each component used in the present Example is shown concretely.
<Components of photosensitive layer composition>
Water-dispersed latex: [(Polymer obtained from “Nipol LX111NF” manufactured by Nippon Zeon Co., Ltd.]]
-BR <1>: [Nippon ZEON Co., Ltd., Nipol BR1220]
BR <2>: [JSR Corporation, RB810]
-Acrylic modified liquid BR: [Osaka Organic Chemical Co., Ltd., BAC-45]
Acrylic monomer: [manufactured by NOF Corporation, 1,9-nonanediol dimethacrylate]
・ Surfactant: [Eomar 0, manufactured by Kao Corporation]
・ Thermal polymerization inhibitor: [Seiko Chemical Co., Ltd., MEHQ (hydroquinone monomethyl ether)]
-Photopolymerization initiator: [Ciba Japan Co., Ltd., Irgacure 651]
UV absorber: [Ciba Japan Co., Ltd., Tinuvin 326]
Plasticizer: [Esso Oil Co., Ltd., Christol 70]

<Components of adhesive material for support adhesive layer>
Polyester: [Toyobo Co., Ltd. “Byron GK330”, number average molecular weight 17000, Tg = 16 ° C., acid components: terephthalic acid, isophthalic acid, sebacic acid]
Curing agent: [isocyanate compound, “Duranate TPA-100” manufactured by Asahi Kasei Chemicals Corporation]

<Components of adhesive material for release adhesive layer>
Polyvinyl alcohol <1>: [Kuraray "Poval LM-10HD", saponification degree 38.0 to 42.0 mol%]
Polyvinyl alcohol <2>: [Kuraray “Poval PVA217E”, saponification degree: 87.0 to 89.0 mol%]
・ Polyamide: [“Tresin EF30T-D” manufactured by Nagase ChemteX Corporation]
Polyvinylpyrrolidone: [Nippon Shokubai Co., Ltd. “Polyvinylpyrrolidone K-30”]
Vinylpyrrolidone-vinyl acetate copolymer: [“PVP / VA S-630” manufactured by ISP Japan Co., Ltd.]
-Polyester: [Toyobo Co., Ltd. “Byron GK330”]
-Polyvinyl butyral: ["S-REC BL-S" manufactured by Sekisui Chemical Co., Ltd.]

<Ingredients of infrared ablation layer composition>
Acrylic resin: [“Precoat 200” manufactured by Negami Kogyo Co., Ltd.]
・ NBR: ["NIPOL DN101" manufactured by Zeon Corporation]
-Carbon black: [Mitsubishi Chemical Corporation "MA8"]
-Plasticizer: [Wako Pure Chemical Industries, Ltd., O-acetyl citrate tributyl]

  A peel test was performed on the prepared flexographic printing plate precursors (Examples 1 to 4, 6 to 8, Comparative Examples 1 and 2, Reference Example), and confirmation of the peel interface and peel force were measured. The test results are shown in Table 1. The peel test was performed at room temperature (23 ° C.) in accordance with JIS K 6854. FIG. 5 schematically shows the state of the peel test.

<Peel test>
(About the uncured state)
A specimen having a width of 3 cm and a length of 20 cm was collected from the prepared flexographic printing plate precursor. As shown in FIG. 5, on one short side of the test body, the support adhesive layer and the photosensitive layer are separated by a length necessary for gripping with one gripping tool of the tensile tester. One end of the support and the support adhesive layer was gripped with one gripping tool. Also, on one short side of this test specimen, the peelable adhesive layer and the photosensitive layer (uncured state) are peeled by the length necessary for gripping with the other gripping tool of the tensile tester. One end of the cover film and the release adhesive layer was held with the other holding tool. Tensile speed 500 mm / min. Then, a T-type peel test was conducted by pulling one end of the support and the support adhesive layer in the peeling direction with one gripping tool (based on JIS K6854-3). The tensile load at this time was defined as peeling force (N / width 3 cm).

(For cured products)
The entire photosensitive layer was cured by exposure for 10 minutes at a distance of about 10 cm from a mercury lamp having a wavelength peak of 360 to 380 nm from the cover film side of the prepared flexographic printing plate precursor. Under the present circumstances, when the light quantity was measured with the UV illuminance meter, it was 19 J / cm < ² > in the UVA area. Next, a specimen having a width of 3 cm and a length of 20 cm was collected from the cured product. Subsequently, a T-type peel test was performed on this test body in the same manner as described above (for an uncured state) (based on JIS K6854-3).

  In addition, the reference example of Table 1 has the same configuration as that of Example 1 for the purpose of confirming whether the uncured portion of the photosensitive layer and the peeling adhesive layer are a peeling interface and the peeling force at this time. Using a test specimen, after exposing for several seconds with a mercury lamp having a wavelength peak of 360 to 380 nm from the support side to form a cured layer serving as a base on the support side of the photosensitive layer, the cover film side of the photosensitive layer is in an uncured state The above peel test was conducted.

  In any of the examples, the uncured photosensitive layer was peeled between the support adhesive layer and the photosensitive layer (interface b). Therefore, in any of the examples, the peeling force between the uncured part of the photosensitive layer and the support adhesive layer (interface b) is between the uncured part of the photosensitive layer and the peeled adhesive layer (interface a). It was shown to be smaller than the peel force of.

  In any of the examples, the cured photosensitive layer was peeled between the release adhesive layer and the photosensitive layer (interface a). From this, the peeling force between the cured portion after curing the photosensitive layer and the support adhesive layer (interface b) is between the cured portion after curing the photosensitive layer and the peeling adhesive layer (interface a). ).

  On the other hand, in Comparative Example 1, since the same adhesive material is used for the support adhesive layer and the release adhesive layer, the photosensitive layer is in an uncured state between the support adhesive layer and the photosensitive layer (interface b). ) And between the photosensitive layer and the release adhesive layer (interface a), the release interface was not stable. For this reason, the peeling force at the interface b could not be measured correctly.

  In Comparative Example 1, the photosensitive layer is in a cured state before peeling between the support adhesive layer and the photosensitive layer (interface b), or between the photosensitive layer and the peeling adhesive layer (interface a). In addition, the cured photosensitive layer was destroyed. For this reason, the peeling force at the interface a or b could not be measured. The tensile load at this time is 23 N / width 3 cm, and this value is the breaking strength of the cured photosensitive layer when cured under the above conditions.

  Here, the adhesive material used for the support adhesive layer and the release adhesive layer of Comparative Example 1 is the same as the adhesive material used for the support adhesive layer of each Example. In this case, when the photosensitive layer of Comparative Example 1 is in a cured state, peeling occurs between the support adhesive layer and the photosensitive layer (interface b), or between the photosensitive layer and the peeling adhesive layer (interface a). Previously, destruction of the cured photosensitive layer occurred. From this, in any of the examples, the peeling force between the cured portion after curing the photosensitive layer and the support adhesive layer (interface b) is the breaking strength of the cured portion after curing the photosensitive layer. It can be said that it is larger. Also, from this, in any of the examples, the peeling force between the cured part after curing the photosensitive layer and the support adhesive layer (interface b) is the breaking strength of the cured part of the photosensitive layer. In relation, it was confirmed that it was 23 N / width over 3 cm.

  In Comparative Example 2, the uncured photosensitive layer was peeled between the support adhesive layer and the photosensitive layer (interface b). On the other hand, when the photosensitive layer is in a cured state, the photosensitive layer cured before being peeled between the support adhesive layer and the photosensitive layer (interface b) or between the photosensitive layer and the release adhesive layer (interface a). Destruction of the layer occurred. For this reason, the peeling force at the interface a or b could not be measured.

  In the reference example, the photosensitive layer in an uncured state (before the main exposure) is between the support adhesive layer and the photosensitive layer (interface b) or between the photosensitive layer and the release adhesive layer ( Before peeling at the interface a), destruction occurred in the uncured part of the photosensitive layer. For this reason, the peeling force at the interface b could not be measured. The tensile load at this time is 4.9 N / width 3 cm, and this value is the breaking strength of the uncured portion of the photosensitive layer. In addition, from this, in any of the examples, when the photosensitive layer is in an uncured state, the peeling force between the photosensitive layer and the peeling adhesive layer (interface a) is the breaking strength of the uncured portion of the photosensitive layer. Thus, it was confirmed that it was 4.9 N / width over 3 cm.

  From the above, it was shown that the flexographic printing plate precursors of the respective examples satisfy all of (A) to (D). On the other hand, it can be seen that Comparative Example 1 does not satisfy at least (A). Moreover, in the comparative example 1, since the same adhesive material is used for a support body adhesive layer and a peeling adhesive layer, it is also clear that (B) is not satisfied. On the other hand, in Comparative Example 2, it can be seen that (D) is not satisfied.

  Further, in the flexographic printing plate precursor of each example, when the photosensitive layer is in an uncured state, the peeling force between the photosensitive layer and the peeling adhesive layer (interface a) is 4.9 N / width over 3 cm, The peeling force between the support adhesive layer and the photosensitive layer (interface b) is 0.8 N / width 3 cm or less. When the photosensitive layer is in a cured state, the separation between the photosensitive layer and the peeling adhesive layer (interface a) ) Was 3.0 N / width 3 cm or less, and it was confirmed that the peel force between the support adhesive layer and the photosensitive layer (interface b) was 23 N / width greater than 3 cm.

  Subsequently, peeling development evaluation was performed about each produced flexographic printing plate precursor. The evaluation method is as described below. The results are shown in Table 1. The shape of the negative pattern applied to the peel development evaluation was as shown in FIG.

<Peeling development evaluation>
(Examples 1-3, 6-8, Comparative Examples 1-2)
Set a negative film on which a predetermined negative pattern is formed on the cover film, put a PVC sheet on the negative film, and apply vacuum to bring the negative film into close contact with the cover film. A predetermined portion of the photosensitive layer was cured by exposure for 10 minutes under the conditions. Subsequently, the uncured portion of the photosensitive layer was removed by peeling the peeling adhesive layer together with the cover film.

Example 4
After peeling the cover film that has been subjected to mold release treatment on one side, set the negative film with a predetermined negative pattern on the exposed release adhesive layer, and then cover the negative film with a PVC sheet and vacuum draw As a result, the negative film was brought into intimate contact with the release adhesive layer, and exposed for 10 minutes from the release adhesive layer side under the same conditions as described above to cure a predetermined portion of the photosensitive layer. Next, the uncured portion of the photosensitive layer was removed by peeling the release adhesive layer.

(Example 5)
After peeling the cover film, a predetermined negative pattern was formed on the infrared ablation layer by a drawing machine (“CDI spark 2120” manufactured by ESKO). Subsequently, the infrared ablation layer side was exposed for 10 minutes under the same conditions as described above to cure a predetermined portion of the photosensitive layer. Next, the uncured portion of the photosensitive layer was removed by peeling the release adhesive layer together with the infrared ablation layer.

Note that the criteria for evaluation of peeling development were as follows.
○: Since the uncured portion of the photosensitive layer was peeled off from the support adhesive layer, and the cured portion of the photosensitive layer was peeled off from the release adhesive layer, the cured portion of the photosensitive layer was left on the support adhesive layer. However, only the uncured part could be peeled off from the support adhesive layer.
X ^{* 1} : The uncured portion of the photosensitive layer was not peeled off from the support adhesive layer, and could not be peeled off.
× ^{* 2} : Since the uncured part of the photosensitive layer was peeled off from the support adhesive layer, the uncured part was peeled off from the support adhesive layer, but the cured part of the photosensitive layer was between the peel adhesive layer It was not peeled and destroyed.

  According to the example, the uncured portion of the photosensitive layer was peeled off from the support adhesive layer, and the cured portion of the photosensitive layer was peeled off from the release adhesive layer, whereby a printing plate having a predetermined pattern was obtained. . That is, the cured portion of the photosensitive layer was left and only the uncured portion was peeled and removed with high accuracy, so that the image reproducibility of the negative was satisfied. Further, even if back exposure is not performed, the cured portion of the photosensitive layer and the support adhesive layer (interface b) are not peeled off before the cured portion is destroyed. It was also confirmed that the adhesion between the cured portion of the substrate and the support adhesive layer was sufficiently secured. Therefore, according to the Example, it was confirmed that the back exposure was not required, the relief depth of the flexographic printing plate could be increased, and the number of work steps could be reduced accordingly.

  On the other hand, in Comparative Example 1, the adhesion between the uncured portion of the photosensitive layer and the peel adhesive layer (interface a) was weak, and the uncured portion could not be peeled and removed, and could not be developed. Further, in Comparative Example 2, the uncured part was peeled and removed, but the adhesion between the cured part of the photosensitive layer and the peeled adhesive layer (interface a) was strong, and the cured part of the photosensitive layer was destroyed and the peel development was performed. could not.

  Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention.

Claims (7)

A support for supporting the photosensitive layer, a support adhesive layer for bonding between the support and the photosensitive layer, the photosensitive layer, and bonding between the photosensitive layer and a cover film covering and protecting the photosensitive layer; A flexographic printing plate precursor for peeling development, which is laminated in the order of a peeling adhesive layer and the cover film, satisfying the following (A) to (D):
(A) The peel force between the uncured portion of the photosensitive layer and the support adhesive layer is smaller than the peel force between the uncured portion of the photosensitive layer and the peel adhesive layer. (B) The photosensitive layer. (C) The peeling force between the cured part after curing and the support adhesive layer is larger than the peeling force between the cured part after curing the photosensitive layer and the peeling adhesive layer (C) The peeling force between the cured portion after curing the photosensitive layer and the support adhesive layer is greater than the breaking strength of the cured portion after curing the photosensitive layer. (D) The photosensitive layer is cured. The peeling force between the later cured portion and the release adhesive layer is smaller than the breaking strength of the cured portion after the photosensitive layer is cured.   The flexographic printing plate precursor for release development according to claim 1, wherein the support adhesive layer contains polyester.   The flexographic printing plate precursor for peel development according to claim 2, wherein the support adhesive layer further contains a curing agent.   The flexographic printing plate for release development according to any one of claims 1 to 3, wherein the photosensitive layer contains a photopolymerizable monomer, rubber, an aqueous dispersion latex, and a photopolymerization initiator. Original edition. The peel force between the uncured portion of the photosensitive layer and the support adhesive layer measured in accordance with JIS K6854 is 0.8 N / width 3 cm or less, and is measured in accordance with JIS K6854. 5. The peeling force between a cured portion obtained by curing the photosensitive layer by UV irradiation with a light amount of UVA 19 J / cm ² and the support adhesive layer is 23 N / width 3 cm or more. The flexographic printing plate precursor for peeling development according to any one of the above.   6. The release adhesive layer contains one or more materials selected from polyvinyl alcohol, polyamide, polyvinyl pyrrolidone, and vinyl pyrrolidone copolymer. 2. A flexographic printing plate precursor for peeling development according to item 1.   The peeling according to any one of claims 1 to 6, wherein an infrared ablation layer containing a binder polymer and an infrared absorbing material is provided between the peeling adhesive layer and the cover film. Flexographic printing plate precursor for development.

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