WO2015152213A1 - Manufacturing method for cylindrical printing plate precursor, platemaking method and manufacturing method for cylindrical printing plate, and removal method for flexographic printing plate - Google Patents

Abstract

　The present invention addresses the problem of providing a manufacturing method for a cylindrical printing plate precursor with which it is possible to achieve adhesiveness between a printing cylinder and a resin sheet or a sheet-like flexographic printing plate, as well as sealability and peelability, and also the problem of providing a cylindrical printing plate, a platemaking method and a manufacturing method therefor, and a removal method for a flexographic printing plate.　This manufacturing method for a cylindrical printing plate precursor is characterized by comprising, in the following order: a preparation step for preparing a resin sheet containing a polymer with a monomer unit derived from a diene hydrocarbon; a winding step for winding the resin sheet around a printing cylinder having a cushion layer; and an adhesion step for adhering by filling a sealing agent into the gap between two portions of the resin sheet to be joined, wherein the sealing agent is a urethane adhesive.

Description

Method for producing cylindrical printing plate precursor, method for producing cylindrical printing plate and method, and method for removing flexographic printing plate

The present invention relates to a method for producing a cylindrical printing plate precursor, a plate making method and a production method for a cylindrical printing plate, and a method for removing a flexographic printing plate.

As a method of forming a printing plate by forming irregularities on the photosensitive resin layer laminated on the support surface, the recording layer formed using the photosensitive composition is exposed with ultraviolet light through the original film, A method of selectively curing an image portion and removing an uncured portion with a developer, so-called “analog plate making” is well known.

When producing a relief printing plate by analog plate making, since an original film using a silver salt material is generally required, the production time and cost of the original film are required. Furthermore, since chemical processing is required for development of the original image film and processing of the development waste liquid is also required, a simpler plate preparation method, for example, a method that does not use the original image film, and development processing are required. The method of not doing is examined.

The relief printing plate is a relief printing plate having a relief layer having irregularities, and the relief layer having such irregularities includes, for example, an elastomeric polymer such as synthetic rubber, a resin such as a thermoplastic resin, Alternatively, it is obtained by patterning a recording layer containing a photosensitive composition containing a mixture of a resin and a plasticizer to form irregularities. Among such relief printing plates, those having a soft relief layer are sometimes referred to as flexographic plates.

Recently, flexographic printing has come to adopt a method in which a cylindrical printing plate precursor having a patternable resin layer formed on a cylindrical support is formed, and then a pattern is formed on the surface and inserted into a plate cylinder. .

As a technique that does not require an original image film, a relief printing plate precursor having a laser-sensitive mask layer element capable of forming an image mask on a recording layer has been proposed.
As a method for producing a cylindrical flexographic printing plate precursor, a method in which a sheet-shaped flexographic printing plate precursor is wound around a cylindrical support and an end portion is fixed with an adhesive is often used.
As a conventional cylindrical flexographic printing plate, for example, the one described in Patent Document 1 is known.

JP 2010-76243 A

In Patent Document 1, the same component as the polymer component contained in the printing plate is used for adhering the edge, and the edge can be adhered and cured, but according to this method, excellent adhesion and sealing properties can be obtained. On the other hand, there was a problem that it could not be peeled off.

The problems to be solved by the present invention are a method for producing a cylindrical printing plate precursor that achieves both adhesiveness between a printing cylinder and a resin sheet or a sheet-like flexographic printing plate, and sealability and peelability, and a cylinder. A printing plate, a method for making the plate, a method for producing the plate, and a method for removing the flexographic printing plate.

The above object has been achieved by the means described in <1> to <3>, <8> to <11> or <13> below. It is shown below together with <4> to <7>, <12> and <14> which are preferred embodiments.
<1> A preparation step of preparing a resin sheet containing a polymer having a monomer unit derived from a diene hydrocarbon, a winding step of winding the resin sheet around a printing cylinder having a cushion layer, and the resin sheets An adhesive step of adhering by filling a sealant in a gap generated in the joint portion in this order, wherein the sealant is a urethane-based adhesive, a method for producing a cylindrical printing plate precursor,
<2> A preparation step of preparing a resin sheet containing a polymer having a monomer unit derived from a diene hydrocarbon, a winding step of winding the resin sheet around a printing cylinder having a cushion layer, and the resin sheet A cylindrical printing plate characterized in that a sealing agent is applied to each of two end portions on both sides in the axial direction, and an adhesion step of adhering to the cushion layer in this order, wherein the sealing agent is a urethane adhesive. Original plate manufacturing method,
<3> A preparation step of preparing a resin sheet containing a polymer having a monomer unit derived from a diene hydrocarbon, a winding step of winding the resin sheet around a printing cylinder having a cushion layer, and the following 1 or 2 The manufacturing method of the cylindrical printing plate precursor, characterized in that the sealing step is a urethane adhesive,
1: an adhering step for adhering by filling a sealant into a gap generated at a joint between the resin sheets;
2: Adhesive step of applying a sealing agent to each of two end portions on both sides in the axial direction of the resin sheet, and adhering to the cushion layer;
<4> In any one of the above items <1> to <3>, in the bonding step, a sealant is further applied to each of two end portions on both sides in the circumferential direction of the resin sheet, and bonded to the cushion layer. A method for producing the described cylindrical printing plate precursor,
<5> The production of the cylindrical printing plate precursor as described in any one of <1> to <4>, wherein the polymer is styrene-butadiene rubber, butadiene rubber, isoprene rubber, or ethylene-propylene-diene rubber. Method,
<6> The method for producing a cylindrical printing plate precursor according to any one of <1> to <5>, wherein the sealing agent contains carbon black,
<7> The method for producing a cylindrical printing plate precursor according to any one of <1> to <6>, wherein the cylindrical printing plate precursor is a cylindrical printing plate precursor for laser engraving,
<8> A preparation step of preparing the cylindrical printing plate precursor manufactured by the manufacturing method according to any one of <1> to <7>, and an engraving step of laser engraving the prepared cylindrical printing plate precursor A method for making a cylindrical printing plate, comprising:
<9> A preparation step of preparing a sheet-shaped flexographic printing plate having a support, a winding step of winding the sheet-shaped flexographic printing plate around a printing cylinder having a cushion layer, and a joint portion of the sheet-shaped flexographic printing plate A method for producing a cylindrical printing plate, comprising an adhesion step of filling a gap with a sealant in this order, wherein the sealant is a urethane-based adhesive,
<10> A preparation step of preparing a sheet-shaped flexographic printing plate having a support, a winding step of winding the sheet-shaped flexographic printing plate around a printing cylinder having a cushion layer, and two axially opposite sides of the flexographic printing plate A method for producing a cylindrical printing plate, characterized in that a sealing agent is applied to each of the end portions and includes an adhesion step for adhering to the cushion layer in this order, wherein the sealing agent is a urethane-based adhesive,
<11> A preparation step for preparing a sheet-shaped flexographic printing plate having a support, a winding step for winding the sheet-shaped flexographic printing plate around a printing cylinder having a cushion layer, and an adhesion step represented by 3 or 4 below: In this order, the sealing agent is a urethane-based adhesive, a method for producing a cylindrical printing plate,
3: Adhesion step of filling a gap generated in the joint portion of the sheet-shaped flexographic printing plate with a sealing agent 4: Applying a sealing agent to each of two end portions on both sides in the axial direction of the sheet-shaped flexographic printing plate, the cushion layer <9> to <11> In the bonding step <12> in the bonding step, a sealing agent is further applied to each of the two ends on both sides in the circumferential direction of the flexographic printing plate, and bonded to the cushion layer. A method for producing a cylindrical printing plate precursor as described in any one of
<13> A cylindrical printing plate produced by the plate making method according to <8> or a cylindrical printing plate produced by the production method according to any one of <9> to <12> is prepared. A flexographic printing comprising a preparatory step, a cutting step for cutting the cylindrical printing plate in the depth direction of the sealant and cutting it, and a removing step for removing the flexographic printing plate from the printing cylinder in this order. How to remove the plate,
<14> The method for removing a flexographic printing plate according to <13>, further comprising a swelling step of supplying a solvent for swelling the sealing agent to the cutting portion between the cutting step and the removing step.

According to the present invention, the adhesion between the printing cylinder and the resin sheet or the sheet-like flexographic printing plate, and the method for producing a cylindrical printing plate precursor that achieves both sealing and peeling properties, and the cylindrical printing plate, The plate making method, the manufacturing method thereof, and the method of removing the flexographic printing plate can be provided.

It is an example of the conceptual diagram which shows the aspect of the calender roll used for formation of a resin sheet. It is an example of the conceptual diagram which shows the structure of the cylindrical printing plate precursor of this invention. It is an example of the conceptual diagram which shows another aspect of a structure of the cylindrical printing plate precursor of this invention. It is an example of the conceptual diagram which shows another aspect of a structure of the cylindrical printing plate precursor of this invention.

Hereinafter, the present invention will be described in detail.
In this specification, “lower limit to upper limit” represents “lower limit or higher and lower limit or lower”, and “upper limit to lower limit” represents “lower limit or higher and lower limit or higher”. That is, it represents a numerical range including the upper limit and the lower limit that are end points.
In the present invention, “mass%” and “wt%” are synonymous, and “part by mass” and “part by weight” are synonymous.
In the present invention, a combination of preferred embodiments is more preferred.

(Method for manufacturing cylindrical printing plate precursor)
The method for producing a cylindrical printing plate precursor according to the present invention includes a preparation step of preparing a resin sheet containing a polymer having a monomer unit derived from a diene hydrocarbon, and the resin sheet on a printing cylinder having a cushion layer. A winding step and a bonding step represented by 1 or 2 below are included in this order, and the sealing agent is a urethane-based adhesive.
1: Adhesion process of adhering by filling a gap generated in the joint between the resin sheets with a sealing agent 2: Applying a sealing agent to each of two end portions on both sides in the axial direction of the resin sheet, and the cushion layer Bonding step for bonding Hereinafter, the case of including the bonding step represented by 1 above is the first aspect of the method for producing a cylindrical printing plate precursor of the present invention, and the case of including the bonding step represented by 2 above is the second case. Also called an aspect.
A first aspect of the method for producing a cylindrical printing plate precursor according to the present invention is a preparation step of preparing a resin sheet containing a polymer having a monomer unit derived from a diene hydrocarbon, a printing cylinder having a cushion layer. , A winding step of winding the resin sheet, and an adhesion step by filling a sealant in a gap generated at a joint between the resin sheets in this order, wherein the sealant is a urethane adhesive And

As a result of intensive studies by the present inventors, a resin sheet containing a polymer having a monomer unit derived from a diene hydrocarbon is bonded with a urethane-based adhesive, whereby a printing cylinder and a resin sheet or sheet-like flexographic printing are performed. Method for producing cylindrical printing plate precursor having both adhesiveness to plate and sealing property and peelability, and cylindrical printing plate, plate making method, method for producing the same, and method for removing flexographic printing plate Found that can be provided.
Although the detailed mechanism is unknown, in order to achieve both adhesiveness, sealability, and peelability, the present inventor considered mechanical bonding and physical interaction, which are considered to be general adhesive adhesive mechanisms. Of chemical interactions, it is presumed that adhesion by physical interaction is preferable.
Specifically, it is important that the polarity difference between the rubber and the sealant is small for appropriate adhesion that achieves both adhesiveness and sealability and peelability, and monomer units derived from diene hydrocarbons. Since the polarities of the resin sheet containing the polymer having γ and the urethane-based adhesive are approximate, it is presumed that appropriate adhesiveness was obtained.

The cylindrical printing plate precursor of the present invention is a flat plate having a flat surface for producing a cylindrical printing plate obtained by the method for producing a cylindrical printing plate precursor of the present invention.
Hereinafter, a preparation process, a winding process, and an adhesion process, which are indispensable processes for the method for producing a cylindrical printing plate precursor according to the present invention, will be described.

<Preparation process>
The method for producing a cylindrical printing plate precursor according to the present invention includes a preparation step of preparing a resin sheet containing a polymer having a monomer unit derived from a diene hydrocarbon.

[Resin sheet]
As the resin sheet, a curable resin composition containing at least a polymer having a monomer unit derived from a diene hydrocarbon (hereinafter, also referred to as “resin composition for forming a resin sheet”) is formed into a sheet shape. It is preferably a sheet cured by the action of heat and / or light later, and more preferably formed by a resin composition for forming a resin sheet to be described later.
The resin sheet is preferably capable of laser engraving.

As a resin sheet forming method, a resin composition for forming a resin sheet is prepared, and if necessary, after removing the solvent from the resin composition, it is melt-extruded on a support, or for resin sheet formation. A method of preparing a resin composition, casting the resin composition on a support, removing the solvent by heating and drying it in an oven, etc., using a calender roll as shown in FIG. A preferred example is a method of molding the composition into a sheet.
In FIG. 1, the calendar roll 3 has first to fourth rolls 4a to 4d, and the interval between these rolls, the temperature of the rolls, and the rotation speed of the rolls can be set. The resin sheet 12 can be obtained by setting the kneaded material 11 between these rolls and rolling it.

[Support]
When using a support for forming a resin sheet, the material used for the support is not particularly limited as long as it can be mounted on a printing cylinder, but a material with high dimensional stability is preferably used. Metals such as steel, stainless steel, and aluminum, polyesters (eg, PET (polyethylene terephthalate), PBT (polybutylene terephthalate), PAN (polyacrylonitrile)) and plastic resins such as polyvinyl chloride, synthetic rubbers such as styrene-butadiene rubber, glass Examples thereof include plastic resins reinforced with fibers (such as epoxy resins and phenol resins). As the support, a PET film or a steel substrate is preferably used.

The resin composition for forming a resin sheet used in the present invention is obtained by, for example, dissolving or dispersing a polymer having a monomer unit derived from a diene hydrocarbon, a polymerizable compound, a fragrance, a plasticizer, and the like in an appropriate solvent, Subsequently, it can manufacture by dissolving a crosslinking agent, a polymerization initiator, a crosslinking accelerator, etc. From the viewpoint of ease of formation of the resin sheet, thickness accuracy of the obtained cylindrical printing plate precursor, and handling of the resin sheet, at least a part, preferably almost all of the solvent component is produced. As the solvent, an organic solvent having moderate volatility is preferable.
The resin sheet, and each component contained in the resin composition for forming a resin sheet suitably used for the production thereof, and a method of curing the resin sheet by the action of heat and / or light (hereinafter simply referred to as “resin sheet curing method”) Will be described later.

<Winding process>
The method for producing a cylindrical printing plate precursor according to the present invention includes a winding step of winding the resin sheet around a printing cylinder having a cushion layer.
In this step, a rectangular resin sheet is used. When the above resin sheet is long, it is first cut into a rectangular shape having an appropriate width and length and then placed on the outer periphery of the printing cylinder.
When winding the resin sheet, it is preferable to wind the resin sheet so that two sides in the circumferential axis direction are parallel to the circumferential axis.
The width of the resin sheet is preferably slightly smaller than the width of the printing cylinder in the central axis direction, and the length is preferably slightly shorter than the outer periphery of the printing cylinder. For this reason, when the resin sheets are butted together, it is preferable that the length be such that there is a gap at the joint. The gap between the joints is preferably small, preferably 0.1 mm to 10 mm, and more preferably 0.1 mm to 5 mm. This gap is filled with a sealing agent in the next bonding step.
The width of the resin sheet is preferably 0.1 to 2.0 m, the length is preferably 0.1 to 2 m, and the thickness is preferably 0.5 to 20 mm.

[Printing cylinder]
The printing cylinder is not particularly limited as long as it has a columnar shape or a cylindrical shape and can be attached to a printing press. A cylinder made of metal, rubber or plastic can be mentioned, and a cylindrical shape is preferable from the viewpoint of weight and handling.
Examples of the material constituting the metal printing cylinder include aluminum, nickel, iron, and alloys including these materials.
Examples of the material constituting the rubber printing cylinder include materials such as ethylene-propylene-diene (EPDM) rubber, fluorine rubber, silicone rubber, styrene-butadiene (SB) rubber, and urethane rubber.
Examples of the material constituting the plastic printing cylinder include materials such as polyester, polyimide, polyamide, polyphenylene ether, polyphenylene thioether, polysulfone, and epoxy resin.

[Cushion layer]
The printing cylinder of the present invention has a cushion layer.
There is no restriction | limiting in particular about the material of a cushion layer, It can form with a well-known material. For example, an elastic foamed resin such as sponge can be exemplified.
When this cushion layer is attached to the outer periphery of the printing cylinder, an adhesive layer or an adhesive layer may be interposed on the printing cylinder side or the cushion layer side. You may wind the resin sheet which laminated | stacked the adhesive layer or the adhesive bond layer around the outer periphery of a printing cylinder. Conversely, a pressure-sensitive adhesive layer or an adhesive layer may be provided on the outer periphery of the printing cylinder, and a resin sheet may be wound thereon.
The outer surface of the printing cylinder may be subjected to physical and / or chemical treatments to promote adhesion between the printing cylinder and the resin sheet. Examples of the physical treatment method include a sand blast method, a wet blast method for injecting a liquid containing particles, a corona discharge treatment method, a plasma treatment method, and an ultraviolet ray or vacuum ultraviolet ray irradiation method. Examples of the chemical treatment method include a strong acid / strong alkali treatment method, an oxidizing agent treatment method, and a coupling agent treatment method.
The cushion layer is preferably formed at the position of the joint between the resin sheet and the edge on the circumference of the wound resin sheet on the printing cylinder, and the entire position where the resin sheet is wound on the printing cylinder. It is preferable to be formed.

<Adhesion process>
The 1st aspect of the manufacturing method of the cylindrical printing plate precursor of this invention includes the adhesion | attachment process adhere | attached by filling the clearance gap which arises in the junction part of resin sheets with a sealing agent.
Moreover, the sealing agent used for this invention is a urethane type adhesive agent.

In this step, it is preferable that after the sealing agent is filled in the gap generated in the joint, a tensile force is applied to the resin sheet so that the gap generated in the joint is narrowed.

In this step, if necessary for curing the sealing agent, a curing step of heating or humidifying the sealing agent may be added after filling the sealing agent.

With reference to FIG. 2, an example of the aspect in which the sealing agent is filled in the joint portion between the resin sheets in the bonding step of the present invention will be described.
FIG. 2 is a cross-sectional view of a cylindrical printing cylinder cut along a plane perpendicular to the axial direction. A cushion layer 20 is provided on the outer periphery of the printing cylinder 10, and a resin sheet 30 is wound around the outer side thereof. A gap 44 is formed in the joint portion of the resin sheet 30, and the sealing agent 50 is supplied to the gap 44 and the joint portion is bonded. In this embodiment, the sealing agent 50 only needs to fill the gap 44 and may or may not be in contact with the cushion layer 20, but from the viewpoint of sealing properties, the sealing agent 50 and the cushion layer 20 are also in contact. Preferably it is.

In addition, the manufacturing method of the cylindrical printing plate precursor according to the present invention may include a known process as necessary in addition to the above-described processes.

The second aspect of the method for producing a cylindrical printing plate precursor according to the present invention is a preparation step for preparing a resin sheet containing a polymer having a monomer unit derived from a diene hydrocarbon, a printing cylinder having a cushion layer. , A winding step of winding the resin sheet, and an adhesion step of adhering two end portions on both sides in the axial direction of the resin sheet and the cushion layer with a sealing agent in this order, wherein the sealing agent is a urethane-based adhesive It is characterized by being.

Subsequently, the winding process and the bonding process in the second aspect will be described. The preparation process in the second aspect is omitted because it is common with the description of the preparation process in the first aspect.

<Winding process>
The 2nd aspect of the manufacturing method of the cylindrical printing plate precursor of this invention includes the winding process which winds the said resin sheet around the printing cylinder which has a cushion layer.
In this step, a rectangular resin sheet is used. When the above resin sheet is long, it is first cut into a rectangular shape having an appropriate width and length and then placed on the outer periphery of the printing cylinder. The width of the resin sheet is preferably smaller than the width in the central axis direction of the printing cylinder, and the length is not particularly limited as long as it is shorter than the outer periphery of the printing cylinder. The distance between the ends in the circumferential direction of the resin sheet is not particularly limited, but the distance between the ends is preferably 1/10 or less of the circumference of the printing cylinder, and is 1/100 of the circumference of the printing cylinder. The following is more preferable. Hereinafter, the description of the printing cylinder and the cushion layer is omitted because it is the same as those of the first embodiment.

<Adhesion process>
The 2nd aspect of the manufacturing method of the cylindrical printing plate precursor of this invention includes the adhesion | attachment process which provides a sealing agent to each of the two edge parts of the axial direction both sides of the said resin sheet, and adhere | attaches with the said cushion layer.
In the second aspect, the sealing agent may be bonded to the cushion layer by applying the sealing agent to the side surface in the axial direction of the resin sheet, or may be bonded to the cushion layer by applying the sealing agent to the back surface of the resin sheet. Alternatively, a sealing agent may be applied to both the side surface and the back surface to adhere to the cushion layer.
When providing a sealing agent to the said side surface, it is preferable from a viewpoint of sealing performance that a sealing agent is provided so that there may be no clearance gap in the width direction of the side surface of a resin sheet.
Further, when the sealing agent is applied to the side surface, it is sufficient that the sealing agent is applied and bonded so as to be in contact with at least the side surface of the end portion and the cushion layer, and the back surface of the end portion and the surface of the cushion layer are in contact with each other. In a state in which the resin sheet side surface and the cushion layer are bonded to each other, it is preferable.
When the sealing agent is applied to the back surface, the sealing agent is preferably applied to a position within 10 cm from the end of the back surface of the resin sheet, and more preferably applied to a position within 5 cm. Moreover, when providing a sealing agent to the said back surface, it is preferable from a sealing viewpoint that a sealing agent is provided so that there may be no clearance gap in the width direction of the side surface of a resin sheet.
Moreover, when providing a sealing agent to the said back surface, the aspect with which the back surface of the resin sheet and the surface of the cushion layer were adhere | attached in the state parallel on both sides of the sealing agent is preferable.
In addition, from the viewpoint of thickness accuracy and, as will be described later, when the sealant contains carbon black, the raised portion of the cured sealant can be flattened by laser engraving, so at least the end part It is preferable that a sealing agent is applied and bonded so as to be in contact with both the side surface and the cushion layer. From the viewpoint of sealing properties, the sealing agent is preferably applied so that there is no gap in the width direction of the side surface of the resin sheet.

With reference to FIG. 3, an example of the aspect which provides a sealing agent to each of the two edge parts on both sides in the axial direction of the sheet and adheres to the cushion layer in the bonding step in the present invention will be described.
FIG. 3 is a cross-sectional view of a cylindrical printing cylinder cut along a plane perpendicular to the axial direction. An arbitrary cushion layer 20 is provided on the outer periphery of the printing cylinder 10, and a resin sheet 30 is wound around the outer side thereof. The two end portions 42 of the resin sheet 30 and the cushion layer 20 are bonded to each other with a sealing agent 50.

Other description of the bonding process in the second aspect is the same as those in the first aspect, and will not be repeated.

In either of the first aspect and the second aspect of the method for producing a cylindrical printing plate precursor according to the present invention, in the bonding step, sealing is further performed at each of two ends on both sides in the circumferential direction of the resin sheet. It is preferable to apply an agent and adhere to the cushion layer. According to said aspect, the cylindrical printing plate excellent in the sealing performance can be obtained.
In the above aspect, a sealing agent may be applied to the side surface in the circumferential direction of the resin sheet and adhered to the cushion layer, or a sealing agent may be applied to the back surface of the resin sheet to adhere the cushion layer, A sealing agent may be applied to both the side surface and the back surface to adhere to the cushion layer. From the viewpoint of thickness accuracy, it is preferable to apply a sealing agent to the circumferential side surface of the resin sheet and bond it to the cushion layer.
When providing a sealing agent to the said side surface, it is preferable from a viewpoint of sealing performance that a sealing agent is provided so that there may be no clearance gap in the width direction of the side surface of a resin sheet.
Further, when the sealing agent is applied to the side surface, it is sufficient that the sealing agent is applied and bonded so as to be in contact with at least the side surface of the end portion and the cushion layer, and the back surface of the resin sheet and the surface of the cushion layer are in contact with each other. In a state in which the resin sheet side surface and the cushion layer are bonded to each other, it is preferable.
When the sealing agent is applied to the back surface, the sealing agent is preferably applied to a position within 10 cm from the end of the back surface of the resin sheet, and more preferably applied to a position within 5 cm. Moreover, when providing a sealing agent to the said back surface, it is preferable from a sealing viewpoint that a sealing agent is provided so that there may be no clearance gap in the width direction of the side surface of a resin sheet.
Moreover, when providing a sealing agent to the said back surface, the aspect adhere | attached in the state which the back surface of the resin sheet and the surface of the cushion layer are contacting is preferable.

FIG. 4 is an example showing an aspect in which a sealing agent is applied to the circumferential side surface of the resin sheet and adhered to the cushion layer. It is the fragmentary sectional perspective view which described the cross section cut | disconnected by the plane containing a resin sheet which is horizontal in the axial direction of a cylindrical printing cylinder. A cushion layer 20 is provided on the outer periphery of the printing cylinder 10, and a resin sheet 30 is wound around the outer side thereof. All the end portions 42 of the resin sheet 30 and the cushion layer 20 are bonded by a sealant 50.

Examples of the application mode of the cylindrical printing plate precursor of the present invention include letterpress, intaglio, stencil, stamp and the like, and preferably a cylindrical printing plate precursor for laser engraving which is a letterpress.
The cylindrical printing plate precursor is preferably a cylindrical flexographic printing plate precursor.
The cylindrical printing plate precursor is preferably a cylindrical printing plate precursor for laser engraving, and more preferably a cylindrical flexographic printing plate precursor for laser engraving.

(Resin sheet and resin composition for forming resin sheet)
Hereinafter, the resin sheet used in the present invention and the components contained in the resin composition for forming a resin sheet will be described.

[Polymer having monomer units derived from diene hydrocarbon]
The resin sheet used in the present invention contains a polymer having a monomer unit derived from a diene hydrocarbon (hereinafter also referred to as “specific polymer”) as an essential component.
The weight average molecular weight of the specific polymer is preferably from 5,000 to 1,600,000, more preferably from 10,000 to 1,000,000, and even more preferably from 15,000 to 600,000. When the weight average molecular weight is 50,000 or more, the form retainability as a single resin is excellent, and when it is 1.6 million or less, it is convenient for preparing a resin composition for forming a resin sheet that is easily dissolved in a solvent. .
In the present invention, the weight average molecular weight is measured by a gel permeation chromatography (GPC) method and is determined by conversion with standard polystyrene. Specifically, for example, GPC uses HLC-8220GPC (manufactured by Tosoh Corporation), and TSKgeL SuperHZM-H, TSKgeL SuperHZ4000, TSKgeL SuperHZ2000 (4.6 mm ID × 15 cm, manufactured by Tosoh Corporation) are used as columns. Three are used and THF (tetrahydrofuran) is used as an eluent. As conditions, the sample concentration is 0.35% by mass, the flow rate is 0.35 ml / min, the sample injection amount is 10 μl, the measurement temperature is 40 ° C., and an IR detector is used. The calibration curve is “Standard sample TSK standard, polystyrene” manufactured by Tosoh Corporation: “F-40”, “F-20”, “F-4”, “F-1”, “A-5000” It is prepared from 8 samples of “A-2500”, “A-1000” and “n-propylbenzene”.

The specific polymer may be a specific polymer having a monomer unit derived from a non-conjugated diene hydrocarbon, but is preferably a specific polymer having a monomer unit derived from a conjugated diene hydrocarbon.

<Specific polymer having monomer units derived from conjugated diene hydrocarbon>
Specific polymers having monomer units derived from conjugated diene hydrocarbons include polymers obtained by polymerizing conjugated diene hydrocarbons, conjugated diene hydrocarbons and other unsaturated compounds, preferably mono Preferred examples include copolymers obtained by polymerizing olefinic unsaturated compounds. In addition, the above polymers and copolymers may be modified, for example, a reactive group such as a (meth) acryloyl group may be introduced at the end, and a part of the internal olefin is hydrogenated. May be. In the following description, polybutadiene in which part of the internal olefin is hydrogenated is also referred to as “partially hydrogenated polybutadiene”, and similarly, polyisoprene in which part of the internal olefin is hydrogenated is also referred to as “partially hydrogenated polyisoprene”. . Further, the copolymer may be a random polymer, a block copolymer, or a graft polymer, and is not particularly limited.

Specific examples of the conjugated diene hydrocarbons include 1,3-butadiene and isoprene. These compounds are used alone or in combination of two or more.
Specific examples of the monoolefin unsaturated compound include styrene, α-methylstyrene, o-methylstyrene, p-methylstyrene, isobutene, vinyl chloride, vinylidene chloride, (meth) acrylamide, (meta ) Acrylamide vinyl acetate, (meth) acrylic acid ester, (meth) acrylic acid and the like.

The polymer obtained by polymerizing the conjugated diene hydrocarbon or the copolymer obtained by polymerizing the conjugated diene hydrocarbon and the monoolefin unsaturated compound is not particularly limited, and specifically, Butadiene polymer, isoprene polymer, styrene-butadiene copolymer, styrene-isoprene copolymer, acrylate ester-isoprene copolymer, methacrylic acid ester and conjugated diene copolymer, acrylonitrile-butadiene-styrene copolymer Examples thereof include styrene-isoprene-styrene block copolymer, styrene-butadiene-styrene block copolymer, and isobutene-isoprene copolymer (butyl rubber).
These polymers may be emulsion-polymerized or solution-polymerized.

In the present invention, the specific polymer may have an ethylenically unsaturated group at the terminal, or may have a partial structure represented by the following formula (A-1).

(In formula (A-1), R ¹ represents a hydrogen atom or a methyl group, A represents O or NH, and * represents a bonding position with another structure.)

In the formula (A-1), A is preferably O.
That is, the specific polymer may have a (meth) acryloyloxy group or a (meth) acrylamide group in the molecule, and more preferably has a (meth) acryloyloxy group.
The specific polymer may have the partial structure represented by the formula (A-1) at either the main chain terminal or the side chain, but preferably has the main chain terminal.
From the viewpoint of printing durability, the specific polymer preferably has two or more partial structures represented by the formula (A-1) in the molecule.

Specific polymers having a partial structure represented by the formula (A-1) include polybutadiene di (meth) acrylate, partially hydrogenated polybutadiene di (meth) acrylate, polyisoprene (meth) acrylate, and partially hydrogenated polyisoprene. Polyolefin (meth) acrylate obtained by reacting an ethylenically unsaturated group-containing compound with a hydroxyl group of a hydroxyl group-containing polyolefin such as (meth) acrylate (for example, BAC-45 (manufactured by Osaka Organic Chemical Co., Ltd.), TEA- 1000, TE-2000, EMA-3000 (manufactured by Nippon Soda Co., Ltd.)).
In addition, modified polyolefins obtained by modifying polyolefins to introduce ethylenically unsaturated bonds (for example, methacrylate-introduced polyisoprene (Kuraprene UC-203, UC-102 (manufactured by Kuraray Co., Ltd.)) are also preferred.

<Polymer having monomer units derived from butadiene and / or isoprene>
In the present invention, the specific polymer is preferably a polymer having monomer units derived from butadiene and / or isoprene.
Specifically, polybutadiene (butadiene rubber), partially hydrogenated polybutadiene, terminal-modified polybutadiene, polyisoprene (isoprene rubber), partially hydrogenated polyisoprene, terminal-modified polyisoprene, SBR (styrene-butadiene rubber), SBS (styrene- Examples thereof include butadiene-styrene triblock copolymer), ABS (acrylonitrile-butadiene-styrene copolymer), SIS (styrene-isoprene-styrene triblock copolymer), and isoprene / butadiene copolymer.
The terminal modification means that the main chain or side chain terminal is modified with an amide group, a carboxy group, a hydroxy group, a (meth) acryloyl group, a glycidyl group, or the like.
Among these, polybutadiene, partially hydrogenated polybutadiene, hydroxyl-terminated polybutadiene, glycidyl ether-modified polybutadiene, polyisoprene, partially hydrogenated polyisoprene, terminal-modified polyisoprene, hydroxyl-terminated polyisoprene, glycidyl ether-modified polyisoprene, SBS, and SIS are preferable. .

The proportion of monomer units derived from butadiene, isoprene or hydrogenated product thereof is preferably 30 mol% or more in total, more preferably 50 mol% or more, and further preferably 80 mol% or more. preferable.

Isoprene is known to be polymerized by 1,2-, 3,4- or 1,4-addition depending on the catalyst and reaction conditions. Good. Among these, from the viewpoint of obtaining desired elasticity, it is preferable to contain cis-1,4-polyisoprene as a main component. When the specific polymer is polyisoprene, the content of cis-1,4-polyisoprene is preferably 50% by mass or more, more preferably 65% by mass or more, and 80% by mass or more. More preferably, it is particularly preferably 90% by mass or more.
Further, as the polyisoprene, natural rubber may be used, and commercially available polyisoprene may be used, and examples thereof include the NIPOL IR series (manufactured by Nippon Zeon Co., Ltd.).

Butadiene is known to be polymerized by 1,2- or 1,4-addition depending on the catalyst and reaction conditions, but the present invention may be polybutadiene polymerized by any of the above additions. Among these, from the viewpoint of obtaining desired elasticity, it is more preferable that 1,4-polybutadiene is a main component.
When the specific polymer is polybutadiene, the content of 1,4-polybutadiene is preferably 50% by mass or more, more preferably 65% by mass or more, and further preferably 80% by mass or more. It is preferably 90% by mass or more.
The content of the cis body and the trans body is not particularly limited, but from the viewpoint of developing rubber elasticity, the cis body is preferable, and the content of cis-1,4-polybutadiene is preferably 50% by mass or more. , 65% by mass or more, more preferably 80% by mass or more, and particularly preferably 90% by mass or more.
A commercially available product may be used as the polybutadiene, and examples thereof include the NIPOL BR series (manufactured by ZEON Corporation), the UBEPOL BR series (manufactured by Ube Industries, Ltd.), and the like.

<Specific polymer having monomer units derived from non-conjugated diene hydrocarbon>
The specific polymer may be a specific polymer having a monomer unit derived from a non-conjugated diene hydrocarbon.
Preferred examples of the specific polymer include a copolymer obtained by polymerizing a nonconjugated diene hydrocarbon and another unsaturated compound, preferably an α-olefinic unsaturated compound. The copolymer may be a random polymer, a block copolymer, or a graft polymer, and is not particularly limited.

Specific examples of the non-conjugated diene hydrocarbons include dicyclopentadiene, 1,4-hexadiene, cyclooctadiene, methylene norbornene, and ethylidene norbornene. Dicyclopentadiene and ethylidene norbornene are preferable. Ethylidene norbornene is more preferable. These compounds are used alone or in combination of two or more.
Specific examples of the monoolefin unsaturated compound include α-olefins having 2 to 20 carbon atoms such as ethylene, propylene, 1-butene, 1-hexene, 4-methyl-pentene, and the like. Ethylene and propylene are preferable, and a combination of ethylene and propylene is more preferable. These compounds are used alone or in combination of two or more.

A polymer obtained by polymerizing the above conjugated diene hydrocarbon or a copolymer obtained by polymerizing a conjugated diene hydrocarbon and an α-olefin unsaturated compound is not particularly limited, but ethylene-α An olefin-diene copolymer is preferred, and ethylene-propylene-diene rubber (EPDM) is more preferred.

Among the above, the specific polymer is preferably styrene-butadiene rubber, butadiene rubber, isoprene rubber, or ethylene-propylene-diene rubber, and more preferably butadiene rubber.

In addition, the specific polymer is preferably a polymer whose main chain mainly contains isoprene or butadiene as a monomer unit, and a part thereof may be hydrogenated to be converted to a saturated bond. In addition, the main chain or the terminal of the polymer may be modified with an amide, a carboxy group, a hydroxy group, a (meth) acryloyl group or the like, or may be epoxidized.
Among these, the specific polymer is preferably exemplified by polybutadiene, polyisoprene, and isoprene / butadiene copolymer from the viewpoint of solubility in a solvent and handling, polybutadiene and polyisoprene are more preferable, and polybutadiene is more preferable.

The specific polymer preferably has a glass transition temperature (Tg) of 20 ° C. or less from the viewpoint of flexibility and rubber elasticity.
The glass transition temperature of the specific polymer is measured according to JIS K7121-1987 using a differential scanning calorimeter (DSC).
In addition, when a specific polymer has two or more glass transition temperatures, it is preferable that at least one is 20 degrees C or less, and it is more preferable that all the glass transition temperatures are 20 degrees C or less.

In the present invention, the specific polymer preferably has an SP value of 14.0 to 18.0 MPa ^1/2 , more preferably 15.0 to 17.5 MPa ^1/2 , and 16.0 to 17.5 MPa. More preferably, it is ^1/2 .
The SP value is the square root of the cohesive energy density of molecules, and represents the magnitude of the cohesive force between molecules, and is a measure of polarity.
It is preferable for the SP value to be in the above-mentioned range because moderate adhesiveness with a urethane-based adhesive can be obtained.
The SP value is calculated based on the Okitsu method described in Journal of the Japan Adhesion Society 29 (3) 1993, 204-211.

The specific polymer is preferably an elastomer or a plastomer. When the specific polymer is an elastomer or a plastomer, good thickness accuracy and dimensional accuracy can be achieved when the printing plate precursor for laser engraving obtained therefrom is formed into a sheet or cylinder. Moreover, since the elasticity required for a flexographic printing plate can be provided, it is preferable.
In the present invention, “plastomer” means that it is easily deformed by heating and deformed by cooling, as described in “New edition polymer dictionary” edited by the Society of Polymer Science, Japan (Asakura Shoten, published in 1988). It means a polymer having the property that it can be solidified into a shaped shape. Plastomer is a term for an elastomer (having the property of instantly deforming according to the external force when an external force is applied and restoring the original shape in a short time when the external force is removed). It does not show such elastic deformation and easily plastically deforms.
In the present invention, the plastomer can be deformed to 200% with a small external force at room temperature (20 ° C.) when the original size is 100%, and does not return to 130% or less even when the external force is removed. Means things. The small external force specifically refers to an external force having a tensile strength of 1 to 100 MPa. More specifically, based on the tensile permanent strain test of JIS K 6262-1997, when the dumbbell-shaped No. 4 test piece specified in JIS K 6251-1993 was used, the above test piece was subjected to a tensile test at 20 ° C. It is possible to stretch without breaking to twice the distance between the marked lines before tensioning, and after holding for 60 minutes when the distance between the marked lines before tension is extended to twice the distance between the marked lines, 5 It means a polymer having a tensile set of 30% or more after a minute. In the present invention, all of the test pieces are JIS K 6262 except that the test piece is dumbbell-shaped No. 4 defined in JIS K6251-1993, the holding time is 60 minutes, and the temperature of the test chamber is 20 ° C. Compliant with the 1997 tensile set test method.
In the case of a polymer that cannot be measured as described above, that is, in a tensile test, a polymer that does not return to its original shape even if a tensile external force is not applied, or a polymer that breaks by applying a small external force during the above measurement is a plastomer. Hit above.
Furthermore, in the present invention, the plastomer has a polymer glass transition temperature (Tg) of less than 20 ° C. In the case of a polymer having two or more Tg, all Tg is less than 20 ° C. The Tg of the polymer can be measured by a differential scanning calorimetry (DSC) method.

In the present invention, an elastomer refers to a polymer that can be stretched to twice the distance between marked lines in the above-described tensile test and that has a tensile set of less than 30% after 5 minutes excluding tensile external force. means.
The viscosity of the specific polymer of the present invention at 20 ° C. is preferably 10 Pa · s to 10 kPa · s, more preferably 50 Pa · s to 5 kPa · s. When the viscosity is within this range, the resin composition can be easily formed into a sheet and the process is simple. In this invention, when a specific polymer is a plastomer, when shape | molding the resin composition for resin sheet formation in a sheet form, favorable thickness precision and dimensional precision can be achieved.

In the present invention, the specific polymer may be used alone or in combination of two or more.
The total content of the specific polymer in the resin sheet used in the present invention is preferably 5 to 90% by mass, more preferably 30 to 90% by mass, and further preferably 50 to 85% by mass with respect to the total solid content of the resin sheet. preferable.
In addition, the total content of the specific polymer in the resin composition for forming a resin sheet used in the present invention is preferably 5 to 90% by mass, more preferably 30 to 90% by mass with respect to the total solid content of the resin composition. 50 to 85% by mass is more preferable. By setting the content of the specific polymer to 5% by mass or more, printing durability sufficient to use the obtained cylindrical printing plate as a printing plate can be obtained, and by setting it to 90% by mass or less, other components Therefore, even when a cylindrical printing plate is used, flexibility sufficient for use as a printing plate can be obtained.
In addition, "solid content total mass" means the total mass remove | excluding volatile components, such as a solvent, from the resin sheet or the resin composition for resin sheet formation.

The resin sheet and the resin composition for forming a resin sheet used in the present invention preferably contain a polymerization initiator, a photothermal conversion agent, a solvent, and other components. Hereinafter, these components will be described in detail.

<Polymerization initiator>
The resin composition for forming a resin sheet of the present invention is preferably formed using a resin composition for forming a resin sheet containing a polymerization initiator. By containing a polymerization initiator, the specific polymer and the crosslinking of the ethylenically unsaturated bonds contained in the polymerizable compound described later are promoted.
As the polymerization initiator, those known to those skilled in the art can be used without limitation, and both a photopolymerization initiator and a thermal polymerization initiator can be used, but crosslinking can be formed with a simple apparatus. A thermal polymerization initiator is preferred. Hereinafter, although the radical polymerization initiator which is a preferable polymerization initiator is explained in full detail, this invention is not restrict | limited by these description.

In the present invention, preferred polymerization initiators include (a) aromatic ketones, (b) onium salt compounds, (c) organic peroxides, (d) thio compounds, (e) hexaarylbiimidazole compounds, f) ketoxime ester compounds, (g) borate compounds, (h) azinium compounds, (i) metallocene compounds, (j) active ester compounds, (k) compounds having a carbon halogen bond, (l) azo compounds, etc. Can be mentioned. Specific examples of the above (a) to (l) are given below, but the present invention is not limited to these.

In the present invention, (c) an organic peroxide and (l) an azo compound are more preferred from the viewpoint of engraving sensitivity and a good relief edge shape when applied to a resin sheet, and (c) an organic compound. Peroxides are particularly preferred.

(A) aromatic ketones, (b) onium salt compounds, (d) thio compounds, (e) hexaarylbiimidazole compounds, (f) ketoxime ester compounds, (g) borate compounds, (h) azinium compounds As compounds (i) metallocene compounds, (j) active ester compounds, and (k) compounds having a carbon halogen bond, the compounds listed in paragraphs 0074 to 0118 of JP-A-2008-63554 are preferably used. it can.
In addition, (c) the organic peroxide and (l) the azo compound are preferably the following compounds.

(C) Organic peroxide Preferred as the thermal polymerization initiator that can be used in the present invention (c) As the organic peroxide, 3,3 ′, 4,4′-tetra (t-butylperoxycarbonyl) benzophenone 3,3 ′, 4,4′-tetra (t-amylperoxycarbonyl) benzophenone, 3,3 ′, 4,4′-tetra (t-hexylperoxycarbonyl) benzophenone, 3,3 ′, 4, 4'-tetra (t-octylperoxycarbonyl) benzophenone, 3,3 ', 4,4'-tetra (cumylperoxycarbonyl) benzophenone, 3,3', 4,4'-tetra (p-isopropylcumylper) Oxycarbonyl) benzophenone, di-t-butyldiperoxyisophthalate, di-t-butyldiperoxyisophthalate, t-butylperoxybenzoate T-butylperoxy-3-methylbenzoate, t-butylperoxylaurate, t-butylperoxypivalate, t-butylperoxy-2-ethylhexanoate, t-butylperoxy-3,5 , 5-trimethylhexanoate, t-butylperoxyneoheptanoate, t-butylperoxyneodecanoate, t-butylperoxyacetate, and the like, α, α'-di (t Peroxyesters such as -butylperoxy) diisopropylbenzene, t-butylcumyl peroxide, di-t-butyl peroxide, t-butylperoxyisopropyl monocarbonate, t-butylperoxy-2-ethylhexyl monocarbonate preferable. Among these, t-butyl peroxybenzoate is particularly preferable from the viewpoint of excellent compatibility.

(L) Azo-based compound Preferred as a polymerization initiator that can be used in the present invention (l) As the azo-based compound, 2,2′-azobisisobutyronitrile, 2,2′-azobispropionitrile, 1,1′-azobis (cyclohexane-1-carbonitrile), 2,2′-azobis (2-methylbutyronitrile), 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2 ′ -Azobis (4-methoxy-2,4-dimethylvaleronitrile), 4,4'-azobis (4-cyanovaleric acid), dimethyl 2,2'-azobisisobutyrate, 2,2'-azobis (2-methylpropion) Amidooxime), 2,2′-azobis [2- (2-imidazolin-2-yl) propane], 2,2′-azobis {2-methyl-N- [1,1-bis (hydroxymethyl) -2 -Hydro Cyethyl] propionamide}, 2,2′-azobis [2-methyl-N- (2-hydroxyethyl) propionamide], 2,2′-azobis (N-butyl-2-methylpropionamide), 2,2 '-Azobis (N-cyclohexyl-2-methylpropionamide), 2,2'-azobis [N- (2-propenyl) -2-methylpropionamide], 2,2'-azobis (2,4,4- Trimethylpentane) and the like.

In the present invention, the organic peroxide (c) is particularly preferable as a polymerization initiator in the present invention from the viewpoint of improving the crosslinkability of the resin sheet and engraving sensitivity.

From the viewpoint of engraving sensitivity, an embodiment in which this (c) organic peroxide and a photothermal conversion agent described later are combined is particularly preferable.
This is because when an organic peroxide is used to cure a resin sheet by thermal crosslinking, an unreacted organic peroxide that does not participate in radical generation remains, but the remaining organic peroxide is a self-reactive addition. Works as an agent and decomposes exothermically during laser engraving. As a result, it is presumed that the engraving sensitivity is increased because the heat generated is added to the irradiated laser energy.
In addition, although explained in full detail in description of a photothermal conversion agent, this effect is remarkable when using carbon black as a photothermal conversion agent. This is because (c) heat generated from carbon black is also transferred to organic peroxide, so heat is generated not only from carbon black but also from organic peroxide. This is because energy generation occurs synergistically.

In the present invention, the polymerization initiator may be used alone or in combination of two or more.
The content of the polymerization initiator in the resin sheet used in the present invention is preferably 0.01 to 30% by mass and more preferably 0.1 to 20% by mass with respect to the total mass of the solid content. Preferably, the content is 1 to 15%.
The content of the polymerization initiator in the resin composition for forming a resin sheet used in the present invention is preferably 0.01 to 30% by mass, and preferably 0.1 to 20% by mass with respect to the total solid content. More preferably, it is 1 to 15%. It is preferable for the content to be in the above range since the curability (crosslinking property) is excellent, the relief edge shape is good when laser engraving is performed, and the rinse property is excellent.

<Photothermal conversion agent>
The resin sheet and the resin composition for forming a resin sheet used in the present invention preferably further contain a photothermal conversion agent. That is, it is considered that the photothermal conversion agent in the present invention promotes thermal decomposition of a cured product during laser engraving by absorbing laser light and generating heat. For this reason, it is preferable to select a photothermal conversion agent that absorbs light having a laser wavelength used for engraving.

When the resin sheet used in the present invention is used for laser engraving using a laser (YAG laser, semiconductor laser, fiber laser, surface emitting laser, etc.) emitting an infrared ray of 700 to 1,300 nm as a light source, It is preferable to use a compound having a maximum absorption wavelength at 700 to 1,300 nm.
Various dyes or pigments are used as the photothermal conversion agent in the present invention.

Among the photothermal conversion agents, as the dye, commercially available dyes and known ones described in documents such as “Dye Handbook” (edited by the Society for Synthetic Organic Chemistry, published in 1970) can be used. Specific examples include those having a maximum absorption wavelength at 700 to 1,300 nm, such as azo dyes, metal complex azo dyes, pyrazolone azo dyes, naphthoquinone dyes, anthraquinone dyes, phthalocyanine dyes, carbonium dyes, diimmonium compounds, and quinoneimine dyes. Preferred are dyes such as methine dyes, cyanine dyes, squarylium dyes, pyrylium salts, metal thiolate complexes. Dyes preferably used in the present invention include cyanine dyes such as heptamethine cyanine dyes, oxonol dyes such as pentamethine oxonol dyes, phthalocyanine dyes, and paragraphs 0124 to 0137 of JP-A-2008-63554. Mention may be made of dyes.

Among the photothermal conversion agents used in the present invention, commercially available pigments and color index (CI) manuals, “latest pigment manuals” (edited by the Japan Pigment Technical Association, published in 1977), “latest pigment application” The pigments described in “Technology” (CMC Publishing, 1986) and “Printing Ink Technology” CMC Publishing, 1984) can be used. Examples of the pigment include pigments described in paragraphs 0122 to 0125 of JP2009-178869A.
Of these pigments, carbon black is preferred.

As long as the dispersibility in the composition is stable, carbon black can be used regardless of the classification according to ASTM or the use (for example, for color, for rubber, for dry battery, etc.). Carbon black includes, for example, furnace black, thermal black, channel black, lamp black, acetylene black and the like. In order to facilitate dispersion, black colorants such as carbon black can be used as color chips or color pastes previously dispersed in nitrocellulose or a binder, if necessary. Such chips and pastes can be easily obtained as commercial products. Examples of carbon black include those described in paragraphs 0130 to 0134 of JP-A-2009-178869.

Only 1 type may be used for the photothermal conversion agent in the resin sheet and resin composition for resin sheet formation used for this invention, and it may use 2 or more types together.
The content of the photothermal conversion agent in the resin sheet varies greatly depending on the molecular extinction coefficient inherent to the molecule, but is preferably in the range of 0.01 to 30% by mass of the total solid content, and 0.05 to 20% by mass. % Is more preferable, and 5 to 20% by mass is particularly preferable.
The content of the photothermal conversion agent in the resin composition for forming a resin sheet varies greatly depending on the molecular extinction coefficient inherent to the molecule, but is preferably in the range of 0.01 to 30% by mass of the total mass of the solid content. 0.05 to 20% by mass is more preferable, and 5 to 20% by mass is particularly preferable.

<Solvent>
The resin composition for forming a resin sheet used in the present invention may contain a solvent.
As the solvent, an organic solvent is preferably used.
Preferred specific examples of the aprotic organic solvent include acetonitrile, tetrahydrofuran, dioxane, toluene, propylene glycol monomethyl ether acetate, methyl ethyl ketone, acetone, methyl isobutyl ketone, ethyl acetate, butyl acetate, ethyl lactate, N, N-dimethylacetamide, N -Methylpyrrolidone, dimethyl sulfoxide.
Preferable specific examples of the protic organic solvent include methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 1-methoxy-2-propanol, ethylene glycol, diethylene glycol and 1,3-propanediol.
Among these, propylene glycol monomethyl ether acetate is particularly preferable.

<Other additives>
Various known additives can be appropriately blended in the resin sheet and the resin composition for forming a resin sheet used in the present invention as long as the effects of the present invention are not impaired. For example, a crosslinking agent, a crosslinking accelerator, a plasticizer, a filler, a wax, a process oil, a metal oxide, an antiozonation agent, an antiaging agent, a polymerization inhibitor, a coloring agent, and the like can be mentioned. Or two or more of them may be used in combination.

<Polymerizable compound>
The resin sheet used in the present invention can be formed by using a resin composition for forming a resin sheet containing a polymerizable compound in order to promote the formation of a crosslinked structure. By containing a polymerizable compound, formation of a crosslinked structure is promoted, and the resulting cylindrical printing plate is excellent in printing durability.
The specific polymer having an ethylenically unsaturated group described above is not included in the polymerizable compound.
Further, the polymerizable compound is preferably a compound having a molecular weight (weight average molecular weight in the case of having a molecular weight distribution) of less than 3,000, and a molecular weight (weight average molecular weight in the case of having a molecular weight distribution) of 1,000. More preferably, it is less than the compound.
The polymerizable compound is preferably a radical polymerizable compound, and is preferably an ethylenically unsaturated compound.

The polymerizable compound used in the present invention is preferably a polyfunctional ethylenically unsaturated compound. It is excellent in the printing durability of the cylindrical printing plate obtained as it is the said aspect.
The polyfunctional ethylenically unsaturated compound is preferably a compound having 2 to 20 terminal ethylenically unsaturated groups. Such a compound group is widely known in this industrial field, and in the present invention, these can be used without any particular limitation.
Examples of compounds derived from an ethylenically unsaturated group in a polyfunctional ethylenically unsaturated compound include unsaturated carboxylic acids (eg, acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid, etc.) Examples include esters and amides. Preferably, esters of unsaturated carboxylic acids and aliphatic polyhydric alcohol compounds, and amides of unsaturated carboxylic acids and aliphatic polyvalent amine compounds are used. In addition, unsaturated carboxylic acid esters having nucleophilic substituents such as hydroxy groups and amino groups, amides and polyfunctional isocyanates, addition reaction products of epoxies, and dehydration condensation reaction products of polyfunctional carboxylic acids Etc. are also preferably used. In addition, an unsaturated carboxylic acid ester having an electrophilic substituent such as an isocyanato group or an epoxy group, an amide and a monofunctional or polyfunctional alcohol, an addition reaction product of an amine, a halogen group, a tosyloxy group, A substituted reaction product of unsaturated carboxylic acid ester, amide and monofunctional or polyfunctional alcohols or amines having a leaving substituent such as the above is also suitable. As another example, a compound group in which a vinyl compound, an allyl compound, an unsaturated phosphonic acid, styrene, or the like is substituted for the above unsaturated carboxylic acid can be used.

The ethylenically unsaturated group contained in the polymerizable compound is preferably an acrylate, methacrylate, vinyl compound, or allyl compound residue from the viewpoint of reactivity. Further, from the viewpoint of printing durability, the polyfunctional ethylenically unsaturated compound preferably has 3 or more ethylenically unsaturated groups.

Specific examples of the monomer of an ester of an aliphatic polyhydric alcohol compound and an unsaturated carboxylic acid include acrylic acid esters such as ethylene glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, polyethylene glycol diacrylate, 1, 3 -Butanediol diacrylate, tetramethylene glycol diacrylate, propylene glycol diacrylate, dipropylene glycol diacrylate, tripropylene glycol diacrylate, polypropylene glycol diacrylate, neopentyl glycol diacrylate, 1,6-hexanediol diacrylate, 1 , 4-cyclohexanediol diacrylate, tetraethylene glycol diacrylate, polytetramethyl Lenglycol diacrylate, 1,8-octanediol diacrylate, 1,9-nonanediol diacrylate, 1,10-decanediol diacrylate, tricyclodecane dimethanol diacrylate, trimethylolpropane triacrylate, trimethylolpropane triacrylate (Acryloyloxypropyl) ether, ditrimethylolpropane tetraacrylate, trimethylolethane triacrylate, pentaerythritol diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol diacrylate, dipentaerythritol hexaacrylate, sorbitol triacrylate, Sorbitol tetraacrylate, sorbitol pentaacrylate , Sorbitol hexaacrylate, tri (acryloyloxyethyl) isocyanurate, polyester acrylate oligomer.

Methacrylic acid esters include tetramethylene glycol dimethacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, propylene glycol dimethacrylate, dipropylene glycol dimethacrylate, tripropylene glycol dimethacrylate, polypropylene Glycol dimethacrylate, neopentyl glycol dimethacrylate, trimethylolpropane trimethacrylate, trimethylolethane trimethacrylate, 1,3-butanediol dimethacrylate, 1,6-hexanediol dimethacrylate, 1,8-octanediol dimethacrylate, 1 , 9-Nonanediol dimetac 1,10-decanediol dimethacrylate, pentaerythritol dimethacrylate, pentaerythritol trimethacrylate, pentaerythritol tetramethacrylate, dipentaerythritol dimethacrylate, dipentaerythritol hexamethacrylate, sorbitol trimethacrylate, sorbitol tetramethacrylate, bis [p- And (3-methacryloxy-2-hydroxypropoxy) phenyl] dimethylmethane, bis [p- (methacryloxyethoxy) phenyl] dimethylmethane, and the like. Of these, trimethylolpropane trimethacrylate and polyethylene glycol dimethacrylate are particularly preferable.

Itaconic acid esters include ethylene glycol diitaconate, propylene glycol diitaconate, 1,3-butanediol diitaconate, 1,4-butanediol diitaconate, tetramethylene glycol diitaconate, pentaerythritol diitaconate Sorbitol tetritaconate and the like.

Examples of crotonic acid esters include ethylene glycol dicrotonate, tetramethylene glycol dicrotonate, pentaerythritol dicrotonate, and sorbitol tetracrotonate.

Examples of isocrotonic acid esters include ethylene glycol diisocrotonate, pentaerythritol diisocrotonate, and sorbitol tetraisocrotonate.

Examples of maleic acid esters include ethylene glycol dimaleate, triethylene glycol dimaleate, pentaerythritol dimaleate, and sorbitol tetramaleate.

Examples of other esters include aliphatic alcohol esters described in JP-B-46-27926, JP-B-51-47334, JP-A-57-196231, JP-A-59-5240, Those having an aromatic skeleton described in JP-A-59-5241 and JP-A-2-226149 and those containing an amino group described in JP-A-1-165613 are also preferably used.

The above ester monomers can be used as a mixture.

Specific examples of amide monomers of aliphatic polyvalent amine compounds and unsaturated carboxylic acids include methylene bisacrylamide, methylene bismethacrylamide, 1,6-hexamethylene bis-acrylamide, 1,6-hexamethylene bis. Examples include methacrylamide, diethylenetriamine trisacrylamide, xylylene bisacrylamide, and xylylene bismethacrylamide.

Examples of other preferable amide monomers include those having a cyclohexylene structure described in JP-B No. 54-21726.

In addition, urethane-based addition polymerizable compounds produced by using an addition reaction of isocyanate and hydroxyl group are also suitable. Specific examples thereof include, for example, one molecule described in JP-B-48-41708. A vinyl urethane containing two or more polymerizable vinyl groups in one molecule obtained by adding a vinyl monomer containing a hydroxyl group represented by the following general formula (i) to a polyisocyanate compound having two or more isocyanato groups. Compounds and the like.

_{CH 2 = C (R) COOCH} 2 CH (R ') OH (i)
(However, R and R ′ each represent H or CH _3. )

Further, urethane acrylates such as those described in JP-A-51-37193, JP-B-2-32293, JP-B-2-16765, JP-B-58-49860, JP-B-56-17654 Urethane compounds having an ethylene oxide skeleton described in JP-B-62-39417 and JP-B-62-39418 are also suitable.

Further, by using addition polymerizable compounds having an amino structure in the molecule described in JP-A-63-277653, JP-A-63-260909, and JP-A-1-105238, a short time can be obtained. A cured composition can be obtained.

Other examples include reacting polyester acrylates, epoxy resins and (meth) acrylic acid as described in JP-A-48-64183, JP-B-49-43191, JP-B-52-30490. And polyfunctional acrylates and methacrylates such as epoxy acrylates. Further, specific unsaturated compounds described in JP-B-46-43946, JP-B-1-40337, JP-B-1-40336, and vinylphosphonic acid-based compounds described in JP-A-2-25493 are also included. be able to. In some cases, a structure containing a perfluoroalkyl group described in JP-A-61-22048 is preferably used. Furthermore, the Japan Adhesion Association magazine vol. 20, no. 7, pages 300 to 308 (1984), which are introduced as photocurable monomers and oligomers, can also be used.

Examples of the vinyl compound include butanediol-1,4-divinyl ether, ethylene glycol divinyl ether, 1,2-propanediol divinyl ether, 1,3-propanediol divinyl ether, 1,3-butanediol divinyl ether, 1,4 -Butanediol divinyl ether, neopentyl glycol divinyl ether, trimethylolpropane trivinyl ether, trimethylol ethane trivinyl ether, hexanediol divinyl ether, tetraethylene glycol divinyl ether, pentaerythritol divinyl ether, pentaerythritol trivinyl ether, pentaerythritol tetravinyl ether, Sorbitol tetravinyl ether, sorbitol pentavinyl ether, ethylene glycol Rudiethylene vinyl ether, ethylene glycol dipropylene vinyl ether, trimethylolpropane triethylene vinyl ether, trimethylolpropane diethylene vinyl ether, pentaerythritol diethylene vinyl ether, pentaerythritol triethylene vinyl ether, pentaerythritol tetraethylene vinyl ether, 1,1,1-tris [4- (2-vinyloxyethoxy) phenyl] ethane, bisphenol A divinyloxyethyl ether, divinyl adipate and the like.

The resin sheet used for this invention and the resin composition used for the formation may use only 1 type of polymeric compounds, and may use 2 or more types together.
The content of the polymerizable compound in the resin sheet used in the present invention is preferably 0.1 to 30% by mass, more preferably 0.5 to 20% by mass with respect to the total solid content of the resin composition. More preferred is 10% by mass.
The content of the polymerizable compound in the resin composition for forming a resin sheet used in the present invention is preferably 0.1 to 30% by mass, and preferably 0.5 to 20% by mass with respect to the total solid content of the resin composition. Is more preferable, and 1 to 10% by mass is still more preferable. Within the above range, the rinsing property of engraving residue generated during laser engraving is excellent, and the printing durability of the obtained cylindrical printing plate is excellent.

<Amount of each component>
The total content of the specific polymer in the resin sheet is preferably 5 to 90% by mass and the content of the polymerization initiator is 0.01 to 30% by mass with respect to the total mass of the solid content of the resin sheet used in the present invention. The content of the photothermal conversion agent is preferably in the range of 0.01 to 30% by mass, and the content of the polymerizable compound is preferably 0 to 30% by mass.
The total content of the specific polymer in the resin composition for forming a resin sheet is preferably 5 to 90% by mass with respect to the total solid content of the resin composition for forming a resin sheet used in the present invention. The content of is preferably 0.01 to 30% by mass, the content of the photothermal conversion agent is preferably in the range of 0.01 to 30% by mass, and the content of the polymerizable compound is 0 to 30% by mass. % Is preferred.

(Resin sheet curing method)
Hereinafter, the resin sheet curing method will be described.
The resin sheet used in the present invention is preferably a sheet cured by the action of heat and / or light.
When the resin sheet used for this invention contains a photoinitiator, it can be hardened | cured by irradiating light.
The light irradiation is preferably performed on the entire surface of the resin sheet.
Examples of light include visible light, ultraviolet light, and electron beam, but ultraviolet light is most preferable. If the support side of the resin sheet is the back side, the surface may only be irradiated with light. However, if the support is a transparent film that transmits light, it is preferable that the back side is further irradiated with light. When the protective film exists, the irradiation from the surface may be performed while the protective film is provided, or may be performed after the protective film is peeled off. When there is a possibility that the crosslinking reaction may be inhibited in the presence of oxygen, light irradiation may be performed after the resin sheet is covered with a vinyl chloride sheet and evacuated.
When the resin sheet contains a thermal polymerization initiator (the above-mentioned photopolymerization initiator can also be a thermal polymerization initiator), it can be cured by heating the resin sheet (crosslinking by heat). ). Examples of the heating means for performing crosslinking by heat include a method of heating a resin sheet for a predetermined time in a hot air oven or a far infrared oven, and a method of contacting a heated roll for a predetermined time.

As the resin sheet curing method, crosslinking by heat is preferable from the viewpoint that the resin sheet can be uniformly cured (crosslinked) from the surface to the inside.
By crosslinking the resin sheet, there is an advantage that firstly the relief formed after laser engraving becomes sharp, and secondly, the adhesiveness of engraving residue generated during laser engraving is suppressed.

[Sealant]
The sealing agent used in the present invention is a urethane-based adhesive.
Urethane adhesive is, for example, an isocyanate group-containing compound such as a polyurethane prepolymer, an isocyanate group-reactive functional group of the adherend, or a reactive group with an isocyanate group such as moisture in the substrate or atmosphere. This is an adhesive that cures by a reaction such that the compound reacts with the prepolymer and performs an adhesive function.
As the urethane adhesive, a one-component adhesive is preferable. Moreover, it is preferable that it is an adhesive agent hardened | cured by humidification.
Examples of commercially available urethane adhesives include polyurethane adhesives and sealant agents 540, 560, and 590 (manufactured by Sumitomo 3M Limited).
The Shore A hardness of the sealant used in the present invention is preferably 40 ° to 65 °, more preferably 50 ° to 65 °, and still more preferably 60 ° to 65 °. If the Shore A hardness of the sealing agent is within the above range, a cylindrical printing plate precursor having excellent sealing properties can be obtained. The Shore A hardness of the sealant means the Shore A hardness of the cured product after the sealant is completely cured.
The 100% tensile stress of the sealant used in the present invention is preferably 0.3 to 15 MPa, more preferably 0.8 to 10 MPa, and further preferably 2 to 10 MPa. If the 100% tensile stress of the sealant is within the above range, a cylindrical printing plate precursor having high adhesive force and excellent sealing properties can be obtained.
In the present invention, the sealing agent preferably has an SP value of 14.0 to 18.0 MPa ^1/2 , more preferably 15.0 to 17.5 MPa ^1/2 , and 16.0 to 17.5 MPa. More preferably, it is ^1/2 . It is preferable for the SP value to be in the above-mentioned range since appropriate adhesiveness with the resin sheet can be obtained.
The SP value of the sealing agent is preferably in the range of the above-mentioned specific polymer SP value ± 1.0 MPa ^1/2 , and more preferably in the range of the specific polymer SP value ± 0.5 MPa ^1/2. The SP value of the specific polymer is more preferably in the range of ± 0.3 MPa ^1/2 .
Moreover, it is preferable that the sealing agent used for this invention contains carbon black.
When the sealing agent used for this invention contains carbon black, it becomes possible by the laser engraving mentioned later to make the swelling part of the hardened sealing agent flat.
Although the sealing agent used for this invention may contain a solvent, it is preferable that content of a solvent is less than 0.2 mass%, and it is more preferable that it is less than 0.1 mass%.
If the content of the solvent is less than 0.2 mass, it is preferable because the sealing agent can be cured in a short time.

(Method for making a cylindrical printing plate)
The plate-making method of the cylindrical printing plate of the present invention includes a preparation step of preparing the cylindrical printing plate precursor of the present invention and an engraving step of laser engraving the prepared cylindrical printing plate precursor.

<Engraving process>
The plate-making method of the cylindrical printing plate of the present invention preferably includes an engraving step of laser engraving the cylindrical printing plate precursor.
The engraving step is a step of forming a layer (hereinafter, also referred to as “relief layer”) in which the resin sheet is laser engraved to form irregularities on the surface.
In the present invention, the resin sheet engraved with laser is referred to as a sheet-shaped flexographic printing plate.
Specifically, it is preferable to form the relief layer by engraving the resin sheet by irradiating a laser beam corresponding to a desired image. In addition, a step of controlling the laser head with a computer based on digital data of a desired image and irradiating the resin sheet with scanning is preferable.
In this engraving process, an infrared laser is preferably used. When irradiated with an infrared laser, the molecules in the resin sheet undergo molecular vibration and heat is generated. When a high-power laser such as a carbon dioxide laser or a YAG laser is used as an infrared laser, a large amount of heat is generated in the laser irradiation portion, and molecules in the resin sheet are selectively cut by molecular cutting or ionization, that is, Sculpture is made. The advantage of laser engraving is that the engraving depth can be set arbitrarily, so that the structure can be controlled three-dimensionally. For example, the portion that prints fine halftone dots can be engraved shallowly or with a shoulder so that the relief does not fall down due to printing pressure, and the portion of the groove that prints fine punched characters is engraved deeply As a result, the ink is less likely to be buried in the groove, and it is possible to suppress the crushing of the extracted characters.
Among them, when engraving with an infrared laser corresponding to the absorption wavelength of the photothermal conversion agent, the resin sheet can be selectively removed with higher sensitivity, and a relief layer having a sharp image can be obtained.

The infrared laser used in the engraving process is preferably a carbon dioxide laser or a semiconductor laser from the viewpoint of productivity, cost, and the like. In particular, a semiconductor infrared laser with a fiber is preferably used. In general, a semiconductor laser can be downsized with high efficiency and low cost of laser oscillation compared to a CO ₂ laser. Moreover, since it is small, it is easy to form an array. Furthermore, the beam shape can be controlled by processing the fiber.
A semiconductor laser having a wavelength of 700 to 1,300 nm can be used, but a laser having a wavelength of 800 to 1,200 nm is preferable, a laser having a wavelength of 860 to 1,200 nm is more preferable, and a wavelength of 900 to 1,100 nm is preferable. Some are particularly preferred.

In the plate making method of the cylindrical printing plate of the present invention, the following rinsing step and drying step may be further included as necessary after the engraving step.
Rinsing step: a step of rinsing the engraved surface of the relief layer surface after engraving with water or a liquid containing water as a main component.
Drying step: a step of drying the engraved relief layer.

When the engraving residue is attached to the engraving surface, a rinsing step of rinsing the engraving residue by rinsing the engraving surface with water or a liquid containing water as a main component may be added. As a means of rinsing, there is a method of washing with tap water, a method of spraying high-pressure water, and a known batch type or conveying type brush type washing machine as a photosensitive resin relief printing machine. For example, when the engraving residue cannot be removed, a rinsing solution to which a surfactant is added may be used.
When the rinsing process for rinsing the engraving surface is performed, it is preferable to add a drying process for drying the engraved relief layer and volatilizing the rinsing liquid.

[Rinse solution]
The rinsing liquid that can be used in the present invention is preferably water or an aqueous rinsing liquid containing water as a main component. The aqueous rinse liquid means a rinse liquid containing water as a main component. Examples of water include tap water, ion exchange water, pure water, and among these, ion exchange water is preferably used.
The pH of the rinse liquid is preferably 8 or higher, more preferably 9 or higher, and still more preferably 10 or higher. Moreover, it is preferable that it is 13.5 or less, it is more preferable that it is 13.0 or less, and it is still more preferable that it is 12.5 or less. In the above range, sufficient rinsing properties (cleaning properties) can be obtained, and handling is easy.
What is necessary is just to adjust pH using an acid and a base suitably in order to make a rinse liquid into said pH range, and the acid and base to be used are not specifically limited.
There is no restriction | limiting in particular as a base (basic compound), Although a well-known basic compound can be used, It is preferable that it is an inorganic basic compound, an alkali metal salt compound and an alkaline-earth metal salt compound More preferably, it is more preferably an alkali metal hydroxide.
Examples of basic compounds include sodium hydroxide, ammonium, potassium, lithium, sodium silicate, potassium, tribasic sodium phosphate, potassium, ammonium, dibasic sodium phosphate, potassium, Examples include inorganic alkali salts such as ammonium, sodium carbonate, potassium, ammonium, sodium hydrogen carbonate, potassium, ammonium, sodium borate, potassium, and ammonium.
Moreover, when using an acid for adjustment of pH, an inorganic acid is preferable, for example, hydrochloric acid, a sulfuric acid, phosphoric acid, and nitric acid are illustrated.

It is preferable that the rinse liquid contains a surfactant.
There is no restriction | limiting in particular as surfactant, A well-known surfactant can be used, Anionic surfactant, a cationic surfactant, an amphoteric surfactant, a nonionic surfactant etc. can be illustrated.
Anionic surfactants include fatty acid salts, abietic acid salts, hydroxyalkane sulfonates, alkane sulfonates, α-olefin sulfonates, dialkyl sulfosuccinates, alkyl diphenyl ether disulfonates, linear alkyl benzene sulfonates, Branched alkyl benzene sulfonates, alkyl naphthalene sulfonates, alkylphenoxy polyoxyethylene propyl sulfonates, polyoxyethylene alkyl sulfophenyl ether salts, N-methyl-N-oleyl taurine sodium, N-alkyl sulfosuccinic acid monoamides Sodium salts, petroleum sulfonates, sulfated castor oil, sulfated beef tallow oil, fatty acid alkyl ester sulfate esters, alkyl sulfate esters, polio Siethylene alkyl ether sulfates, fatty acid monoglyceride sulfates, polyoxyethylene alkylphenyl ether sulfates, polyoxyethylene styryl phenyl ether sulfates, alkyl phosphates, polyoxyethylene alkyl ether phosphates, polyoxy Examples thereof include ethylene alkylphenyl ether phosphate salts, partially saponified products of styrene-maleic anhydride copolymer, partially saponified products of olefin-maleic anhydride copolymer, and naphthalene sulfonate formalin condensates.

Examples of the cationic surfactant include alkylamine salts and quaternary ammonium salts.
Examples of amphoteric surfactants include alkyl carboxybetaines, alkyl imidazolines, and alkylaminocarboxylic acids.
Nonionic surfactants include polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene polystyryl phenyl ether, polyoxyethylene polyoxypropylene alkyl ether, glycerin fatty acid partial esters, sorbitan fatty acid partial esters , Pentaerythritol fatty acid partial esters, propylene glycol monofatty acid esters, sucrose fatty acid partial esters, polyoxyethylene sorbitan fatty acid partial esters, polyoxyethylene sorbitol fatty acid partial esters, polyethylene glycol fatty acid esters, polyglycerin fatty acid partial esters , Fatty acid diethanolamides, N, N-bis-2-hydroxyalkylamines, polyoxyethylene alkyl Min, triethanolamine fatty acid esters, trialkylamine oxides, molecular weight of 200 to 5000 polypropylene glycol, trimethylolpropane, adduct of glycerin or sorbitol polyoxyethylene or polyoxypropylene, acetylene glycol, and the like.

The surfactant that can be used in the present invention is preferably a carboxybetaine compound, a sulfobetaine compound, a phosphobetaine compound, an amine oxide compound, or a phosphine oxide compound. Among these, betaine compounds are more preferable.
Fluorine-based and silicone-based nonionic surfactants can also be used in the same manner.
Surfactant may be used individually by 1 type, or may use 2 or more types together.
The amount of the surfactant used is not particularly limited, but is preferably 0.01 to 20% by mass, more preferably 0.05 to 10% by mass with respect to the total mass of the rinse liquid. .

The rinse liquid may contain an antifoaming agent.
As the antifoaming agent, a general silicone-based self-emulsifying type, emulsifying type, surfactant nonionic HLB (Hydrophile-Lipophile Balance) value of 5 or less can be used. Silicone defoamers are preferred. Among them, an emulsified dispersion type and a solubilized type can be used.
Specific examples of the antifoaming agent include TSA 731 and TSA 739 (manufactured by Toray Dow Corning Co., Ltd.).
The content of the antifoaming agent is preferably 0.001 to 1.0% by mass in the rinse liquid for flexographic printing plate making.

(Method for producing cylindrical printing plate)
The method for producing a cylindrical printing plate of the present invention includes a preparation step of preparing a sheet-shaped flexographic printing plate having a support, a winding step of winding the sheet-shaped flexographic printing plate around a printing cylinder having a cushion layer, and the following 3 Or a bonding process represented by 4 in this order, wherein the sealing agent is a urethane-based adhesive.
3: Adhesion step of filling a gap generated in the joint portion of the sheet-shaped flexographic printing plate with a sealing agent 4: Applying a sealing agent to each of two end portions on both sides in the axial direction of the sheet-shaped flexographic printing plate, the cushion layer The first embodiment of the method for producing a cylindrical printing plate of the present invention includes the case where the bonding step represented by 3 is included, and the case where the bonding step represented by 4 is included. This is also referred to as a second embodiment of the method for producing a cylindrical printing plate.
The first aspect of the method for producing a cylindrical printing plate of the present invention is a preparation step of preparing a sheet-shaped flexographic printing plate having a support, and a winding step of winding the sheet-shaped flexographic printing plate around a printing cylinder having a cushion layer. And an adhesive step of adhering by filling a sealant into a gap generated at a joint portion between the sheet-shaped flexographic printing plates in this order, wherein the sealant is a urethane-based adhesive.

<Sheet flexographic printing plate>
In the present invention, the resin sheet on which laser engraving has been made is referred to as a sheet-shaped flexographic printing plate. The description of laser engraving is omitted because it is the same as the description of the plate making method of the cylindrical printing plate precursor.

Description of the preparation step, the winding step, and the bonding step is omitted because it is the same as the first aspect of the method for manufacturing the cylindrical printing plate precursor.

The second aspect of the method for producing a cylindrical printing plate of the present invention is a preparation step of preparing a sheet-like flexographic printing plate having a support, and a winding step of winding the sheet-like flexographic printing plate around a printing cylinder having a cushion layer. The sheet-like flexographic printing plate is provided with a sealing agent at two ends on both sides in the axial direction and bonded to the cushion layer in this order, and the sealing agent is a urethane-based adhesive Features.
In the second aspect, a sealing agent may be applied to the side surface in the axial direction of the flexographic printing plate to adhere to the cushion layer, or a sealing agent may be applied to the back surface of the flexographic printing plate to adhere the cushion layer. Alternatively, a sealing agent may be applied to both the side surface and the back surface to adhere to the cushion layer.
When the sealing agent is applied to the side surface, it is preferable that the sealing agent is applied so that there is no gap in the width direction of the side surface of the flexographic printing plate from the viewpoint of sealing properties.
Further, when the sealing agent is applied to the side surface, it is sufficient that the sealing agent is applied and bonded so as to be in contact with at least the side surface of the end portion and the cushion layer, and the back surface of the end portion and the surface of the cushion layer are in contact with each other. In this state, the side surface of the flexographic printing plate and the cushion layer are preferably bonded.
When the sealing agent is applied to the back surface, the sealing agent is preferably applied to a position within 10 cm from the end of the back surface of the flexographic printing plate, and more preferably to a position within 5 cm. Moreover, when providing a sealing agent to the said back surface, it is preferable from a viewpoint of sealing performance that a sealing agent is provided so that there may be no clearance gap in the width direction of the side surface of a flexographic printing plate.
Moreover, when providing a sealing agent to the said back surface, the aspect with which the back surface of the flexographic printing plate and the surface of the cushion layer were adhere | attached in the state parallel with the sealing agent interposed is preferable.
In addition, from the viewpoint of thickness accuracy and, as will be described later, when the sealant contains carbon black, the raised portion of the cured sealant can be flattened by laser engraving, so that the flexographic printing plate It is preferable to apply a sealing agent to the side surface in the axial direction and bond it to the cushion layer. From the viewpoint of sealing properties, the sealing agent is preferably applied so that there is no gap in the width direction of the side surface of the flexographic printing plate. In this case, it is only necessary that a sealing agent is applied and adhered so as to contact both the side surface of the end portion and the cushion layer.
The description of the preparation step, the winding step, and the bonding step is omitted because it is the same as the second aspect of the method for manufacturing the cylindrical printing plate precursor.

In the first aspect and the second aspect of the method for producing a cylindrical printing plate of the present invention, a sealing agent is further applied to each of two end portions on both sides in the circumferential direction of the flexographic printing plate in the bonding step. It is preferable to adhere to the cushion layer. According to said aspect, the cylindrical printing plate excellent in the sealing performance can be obtained.
In the above aspect, the sealing agent may be applied to the side surface in the circumferential direction of the flexographic printing plate to adhere to the cushion layer, or the sealing agent may be applied to the back surface of the flexographic printing plate to adhere the cushion layer. Alternatively, a sealing agent may be applied to both the side surface and the back surface to adhere to the cushion layer. From the viewpoint of thickness accuracy, it is preferable to apply a sealing agent to the circumferential side surface of the resin sheet and bond it to the cushion layer.
When the sealing agent is applied to the side surface, it is preferable that the sealing agent is applied so that there is no gap in the width direction of the side surface of the flexographic printing plate from the viewpoint of sealing properties.
Further, when the sealing agent is applied to the side surface, it is sufficient that the sealing agent is applied and bonded so as to be in contact with at least the side surface of the end portion and the cushion layer, and the back surface of the end portion and the surface of the cushion layer are in contact with each other. In this state, the side surface of the flexographic printing plate and the cushion layer are preferably bonded.
When the sealing agent is applied to the back surface, the sealing agent is preferably applied to a position within 10 cm from the end of the back surface of the flexographic printing plate, and more preferably to a position within 5 cm. Moreover, when providing a sealing agent to the said back surface, it is preferable from a viewpoint of sealing performance that a sealing agent is provided so that there may be no clearance gap in the width direction of the side surface of a flexographic printing plate.
Moreover, when providing a sealing agent to the said back surface, the aspect adhere | attached in the state which the back surface of the flexographic printing plate and the surface of the cushion layer are contacting is preferable.

(How to remove the flexographic printing plate)
The method for removing the flexographic printing plate of the present invention includes a cylindrical printing plate produced by the method for producing a cylindrical printing plate of the present invention, or a cylindrical printing plate produced by the method for producing a cylindrical printing plate of the present invention. A cutting step for cutting the cylindrical printing plate in the depth direction of the sealing agent and cutting it, and a removing step for removing the flexographic printing plate from the printing cylinder in this order. .
The sheet-shaped flexographic printing plate removed by the flexographic printing plate removing method of the present invention can be used again for the cylindrical printing plate by being used in the method for producing a cylindrical printing plate of the present invention.
According to the above aspect, for example, the sheet-shaped flexographic printing plate used for printing as a cylindrical printing plate can be removed from the printing cylinder and stored in a sheet shape. Therefore, there are advantages such that the printing cylinder can be used repeatedly, and the storage space for the plate is small.

<Cutting process>
The method for removing the flexographic printing plate of the present invention includes a cutting step of cutting the cylindrical printing plate by cutting in the depth direction of the sealant.
The cut can be made by a commonly used tool such as a cutter knife, and the tool used is not particularly limited.
Moreover, it is preferable to put the said cut | interruption in the interface of a sealing agent and a flexographic printing plate.
The depth of the cut is preferably more than half of the thickness of the sealing agent, and more preferably a depth at which the sealing agent is cut. When a cut is made at a depth to cut the sealing agent, the cut may reach the cushioning agent.

<Removal process>
The method for removing a flexographic printing plate of the present invention includes a removing step of removing the flexographic printing plate from the printing cylinder.
In the removing step, the flexographic printing plate can be removed from the printing cylinder by applying a stress that causes the flexographic printing plate to be peeled off with a finger or the like on the cut produced in the cutting step.
Moreover, you may remove the sealing agent adhering to the flexographic printing plate removed in this process with a cutter knife.
The printing cylinder from which the flexographic printing plate has been removed in this step can be used again as a printing cylinder by removing the cushion layer. For example, it can be used in the method for producing a cylindrical printing plate of the present invention.

<Swelling process>
It is preferable that the method for removing the flexographic printing plate of the present invention further includes a swelling step of supplying a solvent for swelling the sealing agent to the cutting portion between the cutting step and the removing step.
The solvent that swells the sealant is not particularly limited as long as it is a solvent that swells the urethane-based adhesive without dissolving the flexographic printing plate, but a lower alcohol is preferable, and isopropanol is more preferable.

EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to a following example.
In addition, the weight average molecular weight (Mw) and number average molecular weight (Mn) of the polymer in an Example are the values measured by the gel permeation chromatography (GPC) method, unless otherwise indicated.

The components used in Examples and Comparative Examples are as follows.

(Polymer having monomer units derived from diene hydrocarbon)
A-1: UBEPOL BR150: (polybutadiene, Mooney viscosity (ML _{1 + 4} , 100 ° C.): 43, manufactured by Ube Industries, Ltd.)
A-2: Nipol IR2200: (polyisoprene, Mooney viscosity (ML _{1 + 4} , 100 ° C.): 82, manufactured by Nippon Zeon Co., Ltd.)
A-3: Nipol 1502: (styrene butadiene rubber, Mooney viscosity (ML _{1 + 4} , 100 ° C.): 52, manufactured by Nippon Zeon Co., Ltd.)
A-4: MITUI EPT1045: (ethylene-propylene-diene rubber, Mooney viscosity (ML _{1 + 4} , 100 ° C.): 38, ethylene content: 58 mass%, diene content: 5 mass%, diene species: dicyclopentadiene ( DCPD), manufactured by Mitsui Chemicals, Inc.

(Polymerization initiator)
・ Perbutyl Z (t-butyl peroxybenzoate, manufactured by NOF Corporation)
(Photothermal conversion agent)
Carbon black # 45 (manufactured by Mitsubishi Chemical Corporation, particle diameter (arithmetic mean diameter): 24 nm, specific surface area (specific surface area determined by S-BET formula from nitrogen adsorption amount, JIS K 6217): 125 m ² / g, DBP oil absorption: 45cm ³ / 100g)

Moreover, the sealing agent used by the Example and the comparative example is as follows.
(Sealant)
S-1: polyurethane adhesive sealant 560 (urethane adhesive, Shore A hardness: 55, manufactured by Sumitomo 3M Limited)
-S-2: Polyurethane adhesive-Sealant agent 540 (urethane adhesive, Shore A hardness: 40-55, manufactured by Sumitomo 3M Limited)
S-3: polyurethane adhesive sealant 590 (urethane adhesive, Shore A hardness: 60-65, manufactured by Sumitomo 3M Limited)
S-4: Cemedine 1500 (epoxy resin adhesive, manufactured by Cemedine Co., Ltd.)
S-5: Metal lock Y610 (acrylic adhesive, manufactured by Cemedine Co., Ltd.)
S-6: Aron Alpha 911P2 (cyano adhesive, manufactured by Toagosei Co., Ltd.)
S-7: Scotch-weld hot melt adhesive 3764 (hot melt adhesive, manufactured by Sumitomo 3M Limited)
S-8: Bond silicon coke (silicone adhesive, manufactured by Konishi Co., Ltd.)

Example 1
1. Preparation of Resin Composition 1 for Forming Resin Sheet Using an MS-type small pressure kneader (manufactured by Moriyama Co., Ltd.), 85 parts by mass of A-1 and 12 parts by mass of carbon black # 45 were heated to 80 ° C. Then, after kneading for 10 minutes at the front blade 35 rpm and the rear blade 35 rpm, the mixture was cooled to 60 ° C., 3 parts by weight of perbutyl Z was added as a polymerization initiator, and the front blade 20 rpm and the rear blade 20 rpm were further added at 60 ° C. The resin composition for resin sheet formation was prepared by kneading for a minute.

2. Production of Resin Sheet 1 The resin composition for forming a resin sheet obtained above was molded into a sheet shape with a calender roll (manufactured by Nippon Roll Manufacturing Co., Ltd., 4 inverted L-shaped) as shown in FIG. The resin composition for forming a resin sheet was preliminarily kneaded for 10 minutes at a warm-up roll of 50 ° C., the one wound around the roll was cut in the middle, drawn out into a sheet, and once wound up into a roll. Thereafter, the kneaded material was set between the first roll and the second roll of the calender roll, and rolled. As for the temperature of each roll of the calendar roll, the first roll temperature was 50 ° C., the second roll temperature was 60 ° C., the third roll temperature was 70 ° C., and the fourth roll temperature was 80 ° C. The roll interval was 1.0 mm between the first roll and the second roll, 0.9 mm between the second roll and the third roll, and 0.8 mm between the third roll and the fourth roll. The conveyance speed was 1 m / min.
After passing through the fourth roll, the sheet is cut into a width of 20 cm and a length of 20 cm, and heated at 160 ° C. for 20 minutes at a pressure of 4 MPa using a press machine (SA-303, manufactured by Tester Sangyo Co., Ltd.). A crosslinked relief layer having an average film thickness of 0.8 mm was obtained.

3. Formation of cylindrical cushion layer Adhesive layer on a printing cylinder having an inner diameter of 213 mm, width of 300 mm, and thickness of 2.00 mm, so that air bubbles do not enter a cushion tape with an adhesive layer on one side made of polyurethane foam Was carefully coated to adhere to the surface of the print cylinder and a cushion layer was formed on the print cylinder. Further, a double-sided tape having a thickness of 50 μm was laminated on the formed cushion layer to produce a cylindrical product having an adhesive layer exposed on the surface.

4). Formation of Cylindrical Printing Plate Precursor and Cylindrical Printing Plate Step A described below was performed to obtain a cylindrical printing plate precursor. S-3 was used as the sealant.
A concavo-convex pattern is formed on the surface of the obtained cylindrical printing plate precursor using a carbon dioxide laser engraving machine high-quality CO ₂ laser marker ML-9100 series (manufactured by Keyence Co., Ltd.) (output 12W), and cylindrical printing is performed. Got a version.

(Examples 2 to 12 and Comparative Examples 1 to 13)
A cylindrical printing plate precursor was prepared in the same manner as in Example 1 except that the specific polymer, the sealant, and the adhesion process were changed to those shown in Table 1.

<Adhesion process>
[Process A]
The resin sheet was carefully wound around the cylindrical object on which the cushion layer was formed so that air bubbles would not enter. There was a gap consisting of a recess having a width of 5 mm at the joint between both ends of the resin sheet affixed on the cylindrical object. A seam composed of a recess having a width of 5 mm (the depth was 1.8 mm, which is the sum of the thickness of the photosensitive resin cured product layer capable of laser engraving and the thickness of the PET film of 0.1 mm). And was filled with a sealant.
Moreover, the sealing agent was apply | coated so that the side surface of the circumferential direction of a resin sheet and a cushion layer might adhere | attach.
After surplus sealing agent was scraped off with a squeegee, it was allowed to stand for 1 hour to cure the sealing agent.

[Process B]
The resin sheet was carefully wound around the cylindrical object on which the cushion layer was formed so that air bubbles would not enter. There was a gap consisting of a recess having a width of 5 mm at the joint between both ends of the resin sheet affixed on the cylindrical object. A seam composed of a recess having a width of 5 mm (the depth was 1.8 mm, which is the sum of the thickness of the photosensitive resin cured product layer capable of laser engraving and the thickness of the PET film of 0.1 mm). Then, after filling the sealant and scraping off the surplus sealant with a squeegee, it was allowed to stand for 1 hour to cure the sealant.

[Process C]
The resin sheet was carefully wound around the cylindrical object on which the cushion layer was formed so that air bubbles would not enter. The distance between the edge parts of the resin sheet affixed on the cylindrical object was 5 mm in width.
A sealant was applied so that both ends of the resin sheet in the circumferential direction and the cushion layer were bonded, and after removing excess sealant with a squeegee, the sealant was allowed to stand for 1 hour to cure the sealant.
[Process D]
The resin sheet 1 was carefully wound on the cylindrical object on which the cushion layer was formed so that the end of the resin sheet slightly overlapped. Then, after removing the joint, the entire sleeve was covered with a cover sheet (PET sheet) using an adhesive tape, and then heat-treated at (200 ° C.) for 20 minutes to prepare a cylindrical printing plate precursor.

(Evaluation)
<Adhesiveness>
Using a sealing agent, a resin sheet having a width of 10 mm and a length of 10 mm and a resin sheet having a width of 10 mm and a length of 10 mm were bonded with a gap of 2 mm. Using a tensile tester, the tensile speed was 30 mm / min, and the load resistance per unit area was measured. From the viewpoint of printing stain, 1 what load capacity greater than 2N / mm ² per unit area, practically the 1N / mm ² or more but less than 2,1N / mm ² is not level problem ones 3 It was.

<Peelability>
The joint surface between the sealing agent and the plate of the produced cylindrical printing plate was cut with a cutter knife 5 cm from the end and in the depth direction up to the front of the cushion tape, and then it was evaluated whether it could be completely peeled by hand. The sample that was completely peeled off was 1, the sample that had some sealant left on the plate but at a level that had no practical problems, and the sample that had the sealant left on the plate was 3.

<Sealability>
By using the produced cylindrical printing plate for printing, washing the plate with an alkaline cleaning liquid (made by Kao Corp., Magicrin for kitchen cleaning) every 5 km of printing distance, and evaluating the floating of the plate after printing distance of 50 km The sealing function (the penetration of the cleaning liquid into the plate and cushion tape interface) was evaluated. A plate with a plate lift of less than 0.5 mm was set to 1, a plate having a practically no problem level of 0.5 mm to 1 mm was set to 2, and a plate exceeding 1 mm was set to 3.

3: Calendar roll 4a: 1st roll 4b: 2nd roll 4c: 3rd roll 4d: 4th roll 10: Printing cylinder 11: Resin composition for resin sheet formation after preliminary kneading 12: Resin sheet 20: Cushion layer 30 : Resin sheet 42: Resin sheet end 44: Clearance 50: Sealing agent

Claims (12)

1. A preparation step of preparing a resin sheet containing a polymer having a monomer unit derived from a diene hydrocarbon,
   A winding step of winding the resin sheet around a printing cylinder having a cushion layer; and
   An adhesion step of adhering by filling a sealant into a gap generated in a joint portion between the resin sheets in this order,
   The method for producing a cylindrical printing plate precursor, wherein the sealing agent is a urethane-based adhesive.
2. A preparation step of preparing a resin sheet containing a polymer having a monomer unit derived from a diene hydrocarbon,
   A winding step of winding the resin sheet around a printing cylinder having a cushion layer; and
   A sealing agent is applied to each of two end portions on both sides in the axial direction of the resin sheet, and includes an adhesion step of adhering to the cushion layer in this order,
   The method for producing a cylindrical printing plate precursor, wherein the sealing agent is a urethane-based adhesive.
3. 3. The method for producing a cylindrical printing plate precursor according to claim 1, wherein, in the bonding step, a sealing agent is further applied to each of two ends on both sides in the circumferential direction of the resin sheet and bonded to the cushion layer. .
4. The method for producing a cylindrical printing plate precursor according to any one of claims 1 to 3, wherein the polymer is styrene-butadiene rubber, butadiene rubber, isoprene rubber, or ethylene-propylene-diene rubber.
5. The method for producing a cylindrical printing plate precursor according to any one of claims 1 to 4, wherein the sealant contains carbon black.
6. The method for producing a cylindrical printing plate precursor according to any one of claims 1 to 5, wherein the cylindrical printing plate precursor is a cylindrical printing plate precursor for laser engraving.
7. A preparation step of preparing a cylindrical printing plate precursor produced by the production method according to any one of claims 1 to 6, and
   An engraving step of laser engraving the prepared cylindrical printing plate precursor. A method for making a cylindrical printing plate.
8. A preparation step of preparing a sheet-shaped flexographic printing plate having a support;
   A winding step of winding the sheet-shaped flexographic printing plate around a printing cylinder having a cushion layer; and
   An adhesion step of filling a sealant into a gap generated at a joint portion of the sheet-shaped flexographic printing plate in this order,
   The method for producing a cylindrical printing plate, wherein the sealing agent is a urethane-based adhesive.
9. A preparation step of preparing a sheet-shaped flexographic printing plate having a support;
   A winding step of winding the sheet-shaped flexographic printing plate around a printing cylinder having a cushion layer; and
   Including, in this order, an adhesion step in which a sealant is applied to each of the two ends on both sides in the axial direction of the flexographic printing plate and adhered to the cushion layer;
   The method for producing a cylindrical printing plate, wherein the sealing agent is a urethane-based adhesive.
10. The manufacturing of the cylindrical printing plate precursor according to claim 8 or 9, wherein in the bonding step, a sealant is further applied to each of two end portions on both sides in the circumferential direction of the flexographic printing plate, and bonded to the cushion layer. Method.
11. A preparation step of preparing a cylindrical printing plate made by the plate making method according to claim 7, or a cylindrical printing plate produced by the production method according to any one of claims 8 to 10,
    A cutting step in which a cut is made in the depth direction of the sealant of the cylindrical printing plate and cut, and
    A method for removing a flexographic printing plate, comprising: a removing step of removing the flexographic printing plate from the printing cylinder in this order.
12. The method for removing a flexographic printing plate according to claim 11, further comprising a swelling step of supplying a solvent for swelling the sealing agent to the cutting portion between the cutting step and the removing step.

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