WO2014208366A1 - Method for manufacturing laser-engraved printing plate - Google Patents

Abstract

Provided is a method for manufacturing laser-engraved printing plates, the method being capable of efficiently collecting multiple kinds of degradation products, which include solid matter characteristic of the cured layer of laser-engravable printing plates, and of reducing running cost and maintenance load. A method for manufacturing laser-engraved printing plates, the method comprising: a laser-engraving process for laser-engraving the surface of a laser-engravable printing original plate that has at least one layer of a cured film; and a collection process for collecting degradation products generated in the laser-engraving process by being brought into contact with an aqueous alkaline solution of pH 9 or more.

Description

Method for producing laser engraving printing plate

The present invention relates to a method for producing a laser engraving printing plate.

Many methods have been proposed for producing a printing plate by engraving a cured layer of a printing plate precursor, that is, a relief forming layer, by laser engraving. In this method, the resin is melted or decomposed by the heat of the laser, and the portion irradiated with the laser is removed to form a concave pattern. At that time, since a decomposition product melted and decomposed by the laser is generated, it is necessary to collect the decomposition product.

In a conventional laser engraving printing plate manufacturing apparatus, an intake port for vacuum suction of decomposition products is installed in the vicinity of a portion to be processed by laser irradiation and connected to a dust collector, and the activated carbon in the dust collector A method of collecting decomposition products through a filter or a filter having zeolite attached to the surface is employed.

For example, Patent Document 1 has a filter that separates decomposition products sucked together with air from a suction hood from air, and has a dust collector that exhausts air separated by the filter from an exhaust port. An apparatus for producing a relief printing plate that forms projections on the surface of a printing plate is described.

In addition, in Patent Document 2, in order to efficiently remove a wide variety of decomposition products, “a method of removing decomposition products generated in a laser engraving process includes a step of bringing decomposition products into contact with ozone molecules”. Including ".

JP 2013-43408 A JP 2007-144910 A

The decomposition products generated at the time of laser engraving contain not only gas but also a lot of solid waste. In recent years, materials for laser-engraved hardened layers have also diversified, and in the process of contacting activated carbon filters, zeolites attached to the surface, or ozone molecules, these decomposition products are collected. Was insufficient.
Further, depending on the material of the hardened layer, a liquid viscous product is generated as a decomposition product, so that the activated carbon filter or the filter having zeolite attached to the surface in a short time is deteriorated. In addition, gas is collected mainly by an activated carbon filter, and liquid viscous material is collected by a filter having zeolite attached to the surface. For this reason, there is a problem that the running cost and the maintenance load accompanying the periodic replacement of the filters are increased.

The object of the present invention is to solve the above-mentioned problems of the prior art and efficiently collect many kinds of decomposition products specific to the hardened layer of the printing plate for laser engraving, which occurs when the hardened layer is laser engraved. In addition, even if the decomposition product is a liquid viscous product, it can be suitably collected, and the gas and solid viscous product can be collected efficiently at one time, reducing running costs and maintenance load. An object of the present invention is to provide a method for producing a laser engraving printing plate.

As a result of intensive studies to solve the above-mentioned problems, the present inventors collected the decomposition products generated in the laser engraving process in contact with an alkaline aqueous solution, and collected them into a hardened layer of a printing plate for laser engraving. It is possible to efficiently collect many kinds of decomposition products, and even when the decomposition products are liquid viscous products, it is possible to collect both gases and viscous products at once. As a result, the present invention was completed.
That is, the present inventor has found that the above problem can be solved by the following configuration.

(1) A laser engraving process for laser engraving a cured layer of a printing plate precursor for laser engraving having one or more cured layers, and a decomposition product generated in the laser engraving process in contact with an alkaline aqueous solution having a pH of 9 or more. And a collecting step of collecting the laser engraving printing plate.

(2) The method for producing a laser engraving printing plate according to (1), wherein the cured layer contains, as a binder, a material that generates a carboxyl group or a hydroxyl group by an oxidation reaction.

(3) The method for producing a laser engraving printing plate according to (1) or (2), wherein the alkaline aqueous solution contains a surfactant.
(4) The method for producing a laser engraving printing plate according to any one of (1) to (3), wherein the alkaline aqueous solution contains an antifoaming agent.
(5) The collection step captures the decomposition product by allowing the decomposition product and the alkaline aqueous solution to pass through a nozzle and gas-liquid mix to collect the decomposition product (1) to (4) A method for producing engraving printing plates.
(6) The method for producing a laser engraving printing plate according to (5), wherein cavitation is generated in the alkaline aqueous solution in the collecting step.

As shown below, according to the present invention, a wide variety of decomposition products can be efficiently collected, and even if the decomposition product is a liquid viscous product, it is preferably collected. In addition, it is possible to provide a method for producing a laser engraving printing plate that can collect gas and viscous material at a time.

It is a flowchart which shows an example of the manufacturing method of the laser engraving printing plate which concerns on this invention. It is a figure which shows notionally an example of a structure of the apparatus which enforces the manufacturing method of the laser engraving printing plate shown in FIG. It is a figure which shows notionally an example of a structure of the processing apparatus which implements the contact process of the manufacturing method of the laser engraving printing plate shown in FIG. It is a figure which shows notionally another example of a structure of the processing apparatus which implements a contact process.

Hereinafter, the suitable aspect of the manufacturing method of the laser engraving printing plate which concerns on this invention is demonstrated in detail.
First, the features of the present invention will be described in detail.
As described above, the present invention is characterized by having a collection step of collecting a decomposition product generated in the laser engraving step by bringing it into contact with an alkaline aqueous solution having a pH of 9 or more. According to the present invention, the decomposition product can be collected by dissolving or finely dispersing the decomposition product in an alkaline aqueous solution. Accordingly, a wide variety of decomposition products generated from the cured layer of the laser engraving printing plate, that is, the relief forming layer, can be collected, and even when the decomposition product is a liquid viscous product, it is preferably collected. can do.
In particular, when a material that generates a carboxyl group by an oxidation reaction is used as the binder of the cured layer, it can be suitably used because it can be easily collected because it is dissolved in the aqueous solution by a neutralization reaction when brought into contact with an alkaline aqueous solution. Moreover, when using the material which generate | occur | produces a hydroxyl group by an oxidation reaction as a binder of a hardened layer, since it is hydrophilic, it is because it can be finely dispersed in aqueous solution and can be easily collected.
Further, depending on the material contained in the cured layer, for example, a plasticizer, the decomposition product may be a liquid viscous product. When producing a laser engraving printing plate in which the decomposition product becomes a liquid viscous product, it is possible to easily collect even a liquid viscous product by contacting the decomposition product with an alkaline aqueous solution. Therefore, it can be preferably used.

FIG. 1 is a flowchart showing an example of a method for producing a laser engraving printing plate of the present invention.
As shown in FIG. 1, in the manufacturing method of the present invention, laser engraving printing plate precursor is laser engraved, laser engraving step S100 for producing laser engraving printing plate, and decomposition products generated in laser engraving step S100 are sucked. And a collecting step S102 for collecting the decomposition products by the suction step S104 and the processing step S106 for contacting with the alkaline aqueous solution.
Hereinafter, the laser engraving process S100 and the collection process S102 will be described in detail.

[Laser engraving process S100]
The laser engraving step S100 is a step of forming a relief layer by laser engraving a cured layer of a printing plate precursor for laser engraving, that is, a recording layer.
In the present invention, the laser engraving method performed on the printing plate precursor for laser engraving is not particularly limited, and various known laser engraving methods can be used.
As an example, FIG. 2 shows a schematic diagram of an example of a laser engraving machine that performs the laser engraving step S100 of the manufacturing method of the present invention. FIG. 2 is a diagram conceptually showing the laser engraving machine 110 and the dust collector 100 connected to the laser engraving machine 110.

As shown in FIG. 2, the laser engraving machine 110 includes a cylindrical drum 112, an exposure head 114 disposed facing the peripheral surface of the drum 112, and a spray nozzle 116 disposed in the vicinity of the exposure head 114. The suction hood 118 is disposed near the exposure head 114 so as to face the spray nozzle 116. A semiconductor laser is connected to the exposure head 114 via an optical fiber. Further, the exposure head 114 is installed so as to be movable in the sub-scanning direction, that is, the direction perpendicular to the paper surface in FIG. The illustration of the semiconductor laser and the drive unit is omitted.
Further, the suction hood 118 is connected to the gas inlet 16 of the processing apparatus 10 of the dust collector 100 via the pipe 120.

In the laser engraving process S100, a laser engraving machine 110 is used to wind a sheet-shaped printing plate precursor F for laser engraving on the outer peripheral surface of a drum 112 having a cylindrical shape, and the drum 112 is rotated counterclockwise in FIG. That is, while rotating in the main scanning direction, laser light corresponding to image data of an image to be engraved on the printing plate precursor F is emitted from the exposure head 114 toward the printing plate precursor F, and the exposure head 114 is moved in the main scanning direction. Is performed by engraving and recording a two-dimensional image on the surface of the printing plate precursor F at a high speed by scanning at a predetermined pitch in a sub-scanning direction orthogonal to the direction of FIG. In the following description, the printing plate precursor F for laser engraving is also simply referred to as “printing plate precursor F”. The printing plate precursor F will be described in detail later.
As described above, in the laser engraving step S100, the relief of the desired convex portion is formed on the entire surface of the printing plate precursor F by repeating the exposure scanning by the rotation of the drum 112 in the main scanning direction and the intermittent feeding of the exposure head 114 in the sub-scanning direction. An image is formed and a laser engraving printing plate is produced.
Further, it is preferable that the exposure head 114 is controlled by a computer based on digital data of a desired image, and laser irradiation is performed.

The type of laser used in the laser engraving step S100 is not particularly limited, but an infrared laser is preferably used. When irradiated with an infrared laser, the molecules in the cured layer undergo molecular vibrations and generate heat. 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 cured layer 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 cured layer can be selectively removed with higher sensitivity, and a relief layer having a sharp image can be obtained.

As the infrared laser, a carbon dioxide laser (CO ₂ laser) or a semiconductor laser is preferable from the viewpoint of productivity, cost, and the like, and a semiconductor infrared laser with a fiber (FC-LD) is particularly preferable. In general, a semiconductor laser can be downsized with high efficiency and low cost in laser oscillation as compared with 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.
The semiconductor laser preferably has a wavelength of 700 to 1,300 nm, more preferably 800 to 1,200 nm, still more preferably 860 to 1,200 nm, and particularly preferably 900 to 1,100 nm.
In addition, the fiber-attached semiconductor laser is effective for the laser engraving step S100 in the present invention because it can efficiently output laser light by further attaching an optical fiber. Furthermore, the beam shape can be controlled by processing the fiber. For example, the beam profile can have a top hat shape, and energy can be stably given to the plate surface. Details of the semiconductor laser are described in “Laser Handbook 2nd Edition” edited by Laser Society, “Practical Laser Technology” edited by IEICE.
Further, the plate making apparatus provided with the fiber-attached semiconductor laser described in detail in JP-A-2009-172658 and JP-A-2009-214334 can be suitably used in the production method of the present invention.

The laser engraving printing plate produced in the laser engraving step S100 may be subjected to predetermined steps such as the following rinsing step, drying step, and post-crosslinking step, if necessary.
Rinsing step: a step of rinsing the engraved surface of the relief layer after engraving with water or a liquid containing water as a main component.
Drying step: a step of drying the engraved relief layer.
Post-crosslinking step: a step of imparting energy to the relief layer after engraving and further crosslinking the relief layer.
After the laser engraving step S100, the engraving residue is attached to the engraving surface, and therefore a rinse 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 is not smooth, a rinsing liquid to which soap or 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 cured layer and volatilizing the rinsing liquid.
Further, if necessary, a post-crosslinking step for further crosslinking the engraved cured layer may be added. By performing a post-crosslinking step, which is an additional cross-linking step, the relief formed by engraving can be further strengthened.

On the other hand, the decomposition products generated in the laser engraving step S100 are collected in the collecting step S102.

[Laser engraving printing plate precursor]
The printing plate precursor F for laser engraving used in the present invention is not particularly limited as long as it is a known resin plate or rubber plate for flexographic printing having a cured layer for laser engraving. The printing plate precursor F may be in the form of a sheet or a cylinder.
The printing plate precursor F preferably has a cured curable resin composition layer as the cured layer, and the curable resin composition is preferably a thermosetting resin composition.
Further, the curable resin composition preferably contains, as a binder, a material that generates a carboxyl group or a hydroxyl group by an oxidation reaction. This is because a material in which a carboxyl group is generated by an oxidation reaction dissolves in the aqueous solution by a neutralization reaction when brought into contact with an alkaline aqueous solution and can be easily collected. On the other hand, a material in which a hydroxyl group is generated by an oxidation reaction is hydrophilic and can be easily collected.

Further, the layer of the cured resin composition in the printing plate precursor F is preferably a layer having a crosslinked structure, and more preferably a layer crosslinked by heat and / or light.
The method for forming the printing plate precursor F is not particularly limited, but after preparing a curable resin composition and removing the solvent from the curable resin composition, if necessary, melt extrusion onto a substrate. And a method of casting a curable resin composition on a base material and removing at least a part of the solvent in the curable resin composition to form a layer can be preferably exemplified. A method of casting a product and removing at least a part of the solvent in the curable resin composition to form a layer is more preferable. Moreover, it is preferable that the layer of the curable resin composition is then subjected to crosslinking by applying heat and / or light.
The curable resin composition can be produced, for example, by dissolving a crosslinking agent, a binder polymer, and optional components such as a photothermal conversion agent, a fragrance, and a plasticizer in an appropriate solvent. Since most of the solvent components need to be removed at the stage of producing the relief printing plate precursor, the solvent may be a low-molecular alcohol that easily volatilizes, such as methanol, ethanol, n-propanol, isopropanol, propylene glycol monomethyl ether, etc. It is preferable to keep the total amount of solvent added as low as possible by adjusting the temperature.
The thickness of the cured resin layer in the printing plate precursor F is preferably 0.05 mm or more and 20 mm or less, more preferably 0.5 mm or more and 10 mm or less, further preferably 0.5 mm or more and 7 mm or less, and 0.5 mm or more and 3 mm or less. Particularly preferred.
The thickness of the printing plate precursor F is preferably from 0.1 mm to 20 mm, more preferably from 0.5 mm to 10 mm, still more preferably from 0.5 mm to 7 mm, and particularly preferably from 0.5 mm to 3 mm.

The printing plate precursor F may have a layer other than the cured resin layer. For example, the printing plate precursor has a support layer, an adhesive layer, a protective layer, a slip coat layer, a cushion layer, and the like. The well-known layer which may be sufficient can be illustrated. In the following description, the support layer is also simply referred to as “support”.
The material used for the support is not particularly limited, but those having high dimensional stability are preferably used. For example, metals such as steel, stainless steel, aluminum, PET (polyethylene terephthalate), PBT (polybutylene terephthalate), PAN (polyethylene) Examples thereof include plastic resins such as acrylonitrile) and plastic resins such as polyvinyl chloride, synthetic rubbers such as styrene-butadiene rubber, and plastic resins such as epoxy resins reinforced with glass fibers and phenol resins. As the support, a PET film or a steel substrate is preferably used. Among these, a transparent support is preferable, and a PET film is more preferable.
The adhesive layer can be formed with a known adhesive.
The adhesive is preferably a photocurable adhesive, a (meth) acrylate compound having a hydroxyl group, a (meth) acrylate compound having no hydroxyl group, and a photocurable adhesive containing a photopolymerization initiator. More preferably, a (meth) acrylate compound having a hydroxyl group, a (meth) acrylate compound not having a hydroxyl group, and a photocurable adhesive composed only of a photopolymerization initiator are more preferable. As the photocurable adhesive, those described in JP2011-173295A can be suitably used.
Examples of materials that can be used for the adhesive layer, that is, adhesives include, for example, I.I. Those described in the edition of Skeist, “Handbook of Adhesives”, the second edition (1977) can be used.
The material of the protective layer is not particularly limited, but is known as a protective film for a printing plate, for example, a polyester film such as PET (polyethylene terephthalate), a polyolefin film such as PE (polyethylene) or PP (polypropylene). Can be used. The surface of the film may be plain or matted.
The thickness of the protective layer is preferably 25 to 500 μm, more preferably 50 to 200 μm.
There is no restriction | limiting in particular about the material of a cushion layer, What is necessary is just to form with a well-known material. For example, an elastic foamed resin such as sponge can be exemplified.
In addition, the material used for the slip coat layer is a resin that is soluble or dispersible in water, such as polyvinyl alcohol, polyvinyl acetate, partially saponified polyvinyl alcohol, hydroxyalkyl cellulose, alkyl cellulose, polyamide resin, and less adhesive. It is preferable to use it as a main component.

<Layer of curable resin composition>
The printing plate precursor F used in the production method of the present invention preferably has a layer obtained by curing a curable resin composition for laser engraving shown below. In the following description, the curable resin composition for laser engraving is also simply referred to as “resin composition”.
The layer obtained by curing the curable resin composition for laser engraving is a layer capable of laser engraving and is also referred to as a “cured layer” or “recording layer” in the present invention.
The resin composition that can be used in the present invention preferably contains a binder polymer, more preferably contains a binder polymer and a photothermal conversion agent, and the binder polymer, the photothermal conversion agent, and a crosslinking agent. It is more preferable to contain.
Moreover, the resin composition may contain a plasticizer.
Hereinafter, the components of the resin composition will be described.

(Crosslinking agent)
In order to form the resin composition from the viewpoint of forming a crosslinked structure in the recording layer, the resin composition preferably contains a crosslinking agent.
The recording layer preferably has a crosslinked structure.
The crosslinking agent that can be used in the present invention is not particularly limited as long as it can be polymerized by a chemical reaction caused by light or heat to cure the recording layer. In particular, a polymerizable compound having an ethylenically unsaturated group, a reactive silane compound having a reactive silyl group such as an alkoxysilyl group or a halogenated silyl group, a reactive titanium compound, or a reactive aluminum compound is preferably used. A more preferred silane compound is used. These compounds may form a cross-linked structure in the recording layer by reacting with the binder, or may form a cross-linked structure by reacting with these compounds. A crosslinked structure may be formed.
In the following description, the polymerizable compound having an ethylenically unsaturated group is also simply referred to as “polymerizable compound”.
The polymerizable compound that can be used here can be arbitrarily selected from compounds having at least 1, preferably 2 or more, more preferably 2 to 6 ethylenically unsaturated groups.

The resin composition preferably contains a compound having a group represented by the following formula (I). In the following description, a compound having a group represented by the following formula (I) is also referred to as “compound (I)”.
-M (R ¹ ) (R ² ) _n (I)
In the formula (I), R ¹ represents OR ³ or a halogen atom, M represents Si, Ti or Al, n is 2 when M is Si, and n is 2 when M is Ti. When M is Al, n is 1, each of R ² independently represents a hydrocarbon group, OR ³ or a halogen atom, and R ³ represents a hydrogen atom or a hydrocarbon group.

In formula (I), M represents Si, Ti, or Al. Among these, M is preferably Si or Ti, and more preferably Si.
In the formula (I), R ¹ represents OR ³ or a halogen atom, R ³ represents a hydrogen atom or a hydrocarbon group, and the hydrocarbon group includes an alkyl group having 1 to 30 carbon atoms and a carbon number of 6 to 30 Aryl groups having 2 to 30 carbon atoms, aralkyl having 7 to 37 carbon atoms, and the like. Among these, R ³ is preferably a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or an aryl group having 6 to 20 carbon atoms, preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or 6 to 6 carbon atoms. 10 aryl groups are more preferable, and a methyl group or ethyl group is particularly preferable. That is, R ¹ is particularly preferably a methoxy group or an ethoxy group.

In the formula (I), R ² represents a hydrocarbon group, OR ⁴ or a halogen atom. Examples of the hydrocarbon group include an alkyl group having 1 to 30 carbon atoms, an aryl group having 6 to 30 carbon atoms, an alkenyl group having 2 to 30 carbon atoms, and an aralkyl having 7 to 37 carbon atoms. R ⁴ is the same as R ³ described above, and the preferred range is also the same.
R ² is preferably OR ⁴ or a halogen atom, and more preferably OR ⁴ .

N is 2 when M is Si. When M is Si, a plurality of R ² may be the same or different, and is not particularly limited.
N is 2 when M is Ti. When M is Ti, a plurality of R ² may be the same or different and are not particularly limited.
When M is Al, n represents 1.

In addition, said compound (I) may introduce | transduce the group represented by said Formula (I) to a polymer by reaction with a polymer, and has group represented by said Formula (I) before reaction. A group represented by the above formula (I) may be introduced into the polymer.

In the present invention, silica particles, titanium oxide particles, aluminum oxide particles, and the like can also be used as the compound (I). These particles can react with a polymer described later to introduce a group represented by the above formula (I) into the polymer. For example, —SiOH is introduced by a reaction between silica particles and a polymer described later.
In addition, examples of titanium coupling agents include Ajinomoto Fine Techno Co., Ltd. Preneact, Matsumoto Fine Chemical Co., Ltd. Titanium Tetraisopropoxide, Nippon Soda Co., Ltd. Titanium-i-propoxybis (acetylacetonato) titanium, aluminum Examples of the nate coupling agent include acetoalkoxyaluminum diisopropylate.

In this invention, said compound (I) may be used individually by 1 type, and may use 2 or more types together.
In the present invention, the content of the compound (I) contained in the resin composition is preferably 0.1 to 80% by weight, more preferably 1 to 40% by weight, more preferably 5 to 5% in terms of solid content. More preferably, it is 30% by weight.

The polymerizable compound can be arbitrarily selected from compounds having at least 1, preferably 2 or more, more preferably 2 to 6 ethylenically unsaturated groups.
In the present invention, in addition to the purpose of forming a crosslinked structure, from the viewpoint of film properties such as flexibility and brittleness, a compound having only one ethylenically unsaturated group, such as a monofunctional polymerizable compound, A functional monomer may be used.

Hereinafter, a monofunctional monomer that is a compound having one ethylenically unsaturated group in a molecule and a polyfunctional monomer that is a compound having two or more ethylenically unsaturated groups in a molecule, used as a polymerizable compound explain.
Since the recording layer needs to have a crosslinked structure in the film, a polyfunctional monomer is preferably used. The molecular weight of these polyfunctional monomers is preferably 200 to 2,000.
Monofunctional monomers and polyfunctional monomers include esters of unsaturated carboxylic acids such as acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid and polyhydric alcohol compounds, unsaturated carboxylic acids and polyvalent amines. Examples thereof include amides with compounds.

In the present invention, from the viewpoint of improving engraving sensitivity, a compound having a sulfur atom in the molecule is preferably used as the polymerizable compound.
Thus, as a polymeric compound which has a sulfur atom in a molecule | numerator, from a viewpoint of engraving sensitivity improvement, it has two or more ethylenically unsaturated bonds especially, and connects between two ethylenically unsaturated bonds among them. It is preferable to use a polymerizable compound having a carbon-sulfur bond at the site. In the following description, the polymerizable compound having a sulfur atom in the molecule is also referred to as “sulfur-containing polyfunctional monomer” as appropriate.

Examples of the functional group containing a carbon-sulfur bond in the sulfur-containing polyfunctional monomer in the present invention include sulfide, disulfide, sulfoxide, sulfonyl, sulfonamide, thiocarbonyl, thiocarboxylic acid, dithiocarboxylic acid, sulfamic acid, thioamide, and thiocarbamate. , Functional groups containing dithiocarbamate, or thiourea.
In addition, examples of the linking group containing a carbon-sulfur bond that connects two ethylenically unsaturated bonds in the sulfur-containing polyfunctional monomer include —C—S—, —C—S—S—, —NH (C = It is preferably at least one unit selected from the group consisting of S) O—, —NH (C═O) S—, —NH (C═S) S—, and —C—SO ₂ —.

Further, the number of sulfur atoms contained in the molecule of the sulfur-containing polyfunctional monomer is not particularly limited as long as it is 1 or more, and can be appropriately selected according to the purpose, but the engraving sensitivity and the solubility in a coating solvent. From the viewpoint of the balance, 1 to 10 is preferable, 1 to 5 is more preferable, and 1 to 2 is still more preferable.
On the other hand, the number of ethylenically unsaturated groups contained in the molecule is not particularly limited as long as it is 2 or more, and can be appropriately selected according to the purpose. -10 are preferable, 2-6 are more preferable, and 2-4 are more preferable.

The molecular weight of the sulfur-containing polyfunctional monomer in the present invention is preferably 120 to 3,000, more preferably 120 to 1,500, from the viewpoint of the flexibility of the formed film.
Moreover, although the sulfur-containing polyfunctional monomer in this invention may be used independently, you may use it as a mixture with the polyfunctional polymerizable compound and monofunctional polymerizable compound which do not have a sulfur atom in a molecule | numerator.
From the viewpoint of engraving sensitivity, it is preferable to use the sulfur-containing polyfunctional monomer alone or as a mixture of the sulfur-containing polyfunctional monomer and the monofunctional monomer, and use it as a mixture of the sulfur-containing polyfunctional monomer and the monofunctional monomer. Embodiments are more preferred.

In the recording layer, film properties such as brittleness and flexibility can be adjusted by using a polymerizable compound such as a sulfur-containing polyfunctional monomer.
In addition, the total content of the polymerizable compound including the sulfur-containing polyfunctional monomer in the resin composition is preferably 10 to 60% by weight with respect to the nonvolatile component from the viewpoint of flexibility and brittleness of the crosslinked film. A range of 15 to 45% by weight is more preferable.
In addition, when using together a sulfur-containing polyfunctional monomer and another polymeric compound, 5 weight% or more is preferable and, as for the quantity of the sulfur-containing polyfunctional monomer in all the polymeric compounds, 10 weight% or more is more preferable.

(Binder polymer)
The resin composition preferably contains a binder polymer. In the following description, the binder polymer is also simply referred to as “binder”.
The binder is a polymer component contained in the resin composition, and a general polymer compound can be appropriately selected and used alone or in combination of two or more. In particular, when a resin composition for laser engraving is used for a printing plate precursor, it is necessary to select in consideration of various performances such as laser engraving property, ink acceptability, and engraving residue dispersibility.
The binder includes polystyrene resin, polyester resin, polyamide resin, polyurea resin, polyamideimide resin, polyurethane resin, polysulfone resin, polyethersulfone resin, polyimide resin, polycarbonate resin, hydrophilic polymer containing hydroxyethylene units, acrylic resin, acetal. A resin, an epoxy resin, a polycarbonate resin, rubber, a thermoplastic elastomer, or the like can be selected and used.

For example, from the viewpoint of laser engraving sensitivity, a polymer containing a partial structure that is thermally decomposed by exposure or heating is preferable. Preferred examples of such a polymer include those described in paragraph 0038 of JP2008-163081A. For example, when the purpose is to form a soft and flexible film, a soft resin or a thermoplastic elastomer is selected. This is described in detail in paragraphs 0039 to 0040 of JP-A-2008-163081. Furthermore, it is preferable to use a hydrophilic or alcoholic polymer from the viewpoint of easy preparation of the resin composition and improvement of resistance to oil-based ink in the obtained printing plate. As the hydrophilic polymer, those described in detail in paragraph 0041 of JP-A-2008-163081 can be used.

In addition, when used for the purpose of curing by heating or exposure and improving the strength, a polymer having a carbon-carbon unsaturated bond in the molecule is preferably used.
Examples of such a binder include a polymer containing a carbon-carbon unsaturated bond in the main chain, such as SB (polystyrene-polybutadiene), SBS (polystyrene-polybutadiene-polystyrene), SIS (polystyrene-polyisoprene-polystyrene), SEBS. (Polystyrene-polyethylene / polybutylene-polystyrene) and the like.
As a polymer having a carbon-carbon unsaturated bond in the side chain, a carbon-carbon unsaturated bond such as an allyl group, an acryloyl group, a methacryloyl group, a styryl group, or a vinyl ether group is introduced into the side chain of the polymer backbone. It is obtained with. The method for introducing a carbon-carbon unsaturated bond into the polymer side chain is as follows: (1) A structural unit having a polymerizable group precursor formed by bonding a protective group to a polymerizable group is copolymerized with the polymer to remove the protective group. (2) preparing a polymer compound having a plurality of reactive groups such as hydroxyl group, amino group, epoxy group and carboxyl group, and reacting with these reactive groups and carbon- A known method such as a method of introducing a compound having a carbon unsaturated bond by polymer reaction can be employed. According to these methods, the amount of unsaturated bonds and polymerizable groups introduced into the polymer compound can be controlled.

As the binder, it is particularly preferable to use a polymer having a hydroxyl group (—OH). In the following description, a polymer having a hydroxyl group is also referred to as a “specific polymer”. The skeleton of the specific polymer is not particularly limited, but an acrylic resin, an epoxy resin, a hydrophilic polymer containing a hydroxyethylene unit, a polyvinyl acetal resin, a polyester resin, and a polyurethane resin are preferable.
As the acrylic monomer used for the synthesis of the acrylic resin having a hydroxyl group, for example, (meth) acrylic acid esters and crotonic acid esters (meth) acrylamides having a hydroxyl group in the molecule are preferable. Specific examples of such a monomer include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and the like. A copolymer obtained by polymerizing these and a known (meth) acrylic monomer or vinyl monomer can be preferably used.
It is also possible to use an epoxy resin having a hydroxy group in the side chain as the specific polymer. As a preferred specific example, an epoxy resin obtained by polymerizing an adduct of bisphenol A and epichlorohydrin as a raw material monomer is preferable.
As the polyester resin, a polyester resin composed of hydroxyl carboxylic acid units such as polylactic acid can be preferably used. Specific examples of the polyester resin include polyhydroxyalkanoate (PHA), lactic acid-based polymer, polyglycolic acid (PGA), polycaprolactone (PCL), poly (butylene succinic acid), and derivatives or mixtures thereof. Those selected from the group consisting of are preferred.

The specific polymer is preferably a polymer having an atom and / or group capable of reacting with the compound (I), and is a polymer having an atom and / or group capable of reacting with the compound (I). More preferably, the binder polymer is insoluble in water and soluble in an alcohol having 1 to 4 carbon atoms.
Although it does not specifically limit as said atom and / or group which can react with said compound (I), An ethylenically unsaturated bond, an epoxy group, an amino group, a (meth) acryloyl group, a mercapto group, a hydroxy group is illustrated, These Among these, a hydroxy group is preferably exemplified.
As a specific polymer in the present invention, polyvinyl butyral (PVB), an acrylic resin having a hydroxyl group in a side chain, and a film having good engraving sensitivity and good film property while achieving both water-based ink suitability and UV ink suitability Preferred examples include an epoxy resin having a hydroxyl group in the side chain.

Further, as described above, from the viewpoint of solubility in an alkaline aqueous solution, it is preferable to use a material that generates a carboxyl group or a hydroxyl group by an oxidation reaction as a binder.
Examples of such a binder include PVB (polyvinyl butyral) and PVA (polyvinyl alcohol), and materials having a double bond (C = C) in the main chain, such as polyisoprene, BL (polybutadiene), and the like. Is more preferable.

The specific polymer that can be used in the present invention is a photothermal conversion agent capable of absorbing light having a wavelength of 700 to 1,300 nm, which will be described later, which is a preferred combined component of the resin composition for laser engraving constituting the recording layer in the present invention. In combination, the glass transition temperature Tg is particularly preferably 20 ° C. or higher because the engraving sensitivity is improved. Hereinafter, a polymer having such a glass transition temperature is referred to as a non-elastomer. That is, an elastomer is generally defined academically as a polymer having a glass transition temperature of room temperature or lower. In this regard, reference can be made to “Science University Dictionary 2nd Edition, Editor International Science Foundation, Issued by Maruzen Co., Ltd., P154”.
Therefore, a non-elastomer refers to a polymer having a glass transition temperature exceeding normal temperature. Although there is no restriction | limiting in the upper limit of the glass transition temperature of a specific polymer, it is preferable from a viewpoint of handleability that it is 200 degrees C or less, and it is more preferable that it is 25 degreeC or more and 120 degrees C or less.

When a polymer having a glass transition temperature of room temperature, that is, 20 ° C. or higher is used, the specific polymer takes a glass state at room temperature. Therefore, thermal molecular motion is considerably suppressed as compared with a rubber state. Is in a state. In laser engraving, in addition to the heat imparted by the infrared laser during laser irradiation, the heat generated by the function of the photothermal conversion agent used in combination with the desired heat is transferred to a specific polymer around it, which decomposes and dissipates. As a result, the recess is formed by engraving.
When a specific polymer is used, if a photothermal conversion agent is present in a state where thermal molecular motion of the specific polymer is suppressed, heat transfer to the specific polymer and thermal decomposition are considered to occur effectively. It is presumed that the engraving sensitivity is further increased by the effect.

Specific examples of binders preferably used in the present invention are illustrated below.

(1) Polyvinyl acetal and derivatives thereof Polyvinyl acetal is a compound obtained by cyclic acetalization of polyvinyl alcohol obtained by saponifying polyvinyl acetate. Further, the polyvinyl acetal derivative is obtained by modifying the polyvinyl acetal or adding another copolymer component.
The acetal content in the polyvinyl acetal, that is, the total number of moles of the starting vinyl acetate monomer is 100%, and the mole% of vinyl alcohol units to be acetalized is preferably 30 to 90%, more preferably 50 to 85%. 55 to 78% is particularly preferable.
The vinyl alcohol unit in the polyvinyl acetal is preferably 10 to 70 mol%, more preferably 15 to 50 mol%, particularly preferably 22 to 45 mol%, based on the total number of moles of the vinyl acetate monomer as a raw material.
Further, the polyvinyl acetal may have vinyl acetate units as other components, and the content thereof is preferably 0.01 to 20 mol%, more preferably 0.1 to 10 mol%. The polyvinyl acetal derivative may further have other copolymer units.
Examples of the polyvinyl acetal include polyvinyl butyral, polyvinyl propylal, polyvinyl ethylal, and polyvinyl methylal. Among these, polyvinyl butyral (PVB) is preferable.
Polyvinyl butyral is usually a polymer obtained by converting polyvinyl alcohol into butyral. A polyvinyl butyral derivative may also be used.
Examples of polyvinyl butyral derivatives include acid-modified PVB in which at least part of the hydroxyl group is modified to an acid group such as a carboxyl group, modified PVB in which part of the hydroxyl group is modified to a (meth) acryloyl group, and at least part of the hydroxyl group is an amino group Modified PVB, modified PVB in which ethylene glycol, propylene glycol, or a multimer thereof is introduced into at least a part of the hydroxyl group.
The molecular weight of polyvinyl acetal is preferably 5,000 to 800,000, and more preferably 8,000 to 500,000 as a weight average molecular weight from the viewpoint of maintaining a balance between engraving sensitivity and film property. Further, from the viewpoint of improving the rinsing property of engraving residue, it is particularly preferably 50,000 to 300,000.

Hereinafter, although polyvinyl butyral (PVB) and its derivative (s) are mentioned and demonstrated as a particularly preferable example of polyvinyl acetal, it is not limited to this.
As PVB, it can also be obtained as a commercial product, and preferred specific examples thereof include “ESREC B” series and “ESREC K (KS) manufactured by Sekisui Chemical Co., Ltd. from the viewpoint of alcohol solubility, particularly ethanol solubility. ) ”Series,“ Denka Butyral ”manufactured by Denki Kagaku Kogyo Co., Ltd. is preferable. More preferably, from the viewpoint of alcohol solubility, in particular ethanol solubility, “ESREC B” series manufactured by Sekisui Chemical Co., Ltd. and “Denka Butyral” manufactured by Denki Kagaku Kogyo Co., Ltd. are particularly preferable. “Sleck B” series made by “Sleck B”, “BL-1”, “BL-1H”, “BL-2”, “BL-5”, “BL-S”, “BX-L”, “BM-S” , “BH-S”, “Denkabutyral” manufactured by Denki Kagaku Kogyo Co., Ltd., “# 3000-1,” “# 3000-2,” “# 3000-4,” “# 4000-2,” “# 6000” -C ","# 6000-EP ","# 6000-CS ","# 6000-AS ".
When a recording layer is formed using PVB as a specific polymer, a method in which a solution dissolved in a solvent is cast and dried is preferable from the viewpoint of the smoothness of the film surface.

In addition to the polyvinyl acetal and its derivatives, as the specific polymer, an acrylic resin obtained by using a known acrylic monomer having a hydroxyl group in the molecule can be used. In addition, a novolak resin that is a resin obtained by condensing phenols and aldehydes under acidic conditions can also be used as the specific polymer. Moreover, it is also possible to use the epoxy resin which has a hydroxyl group in a side chain as a specific polymer.

Among the specific polymers, polyvinyl butyral and derivatives thereof are particularly preferable from the viewpoint of rinsing properties and printing durability when used as a recording layer.
The content of the hydroxyl group contained in the specific polymer is preferably 0.1 to 15 mmol / g, more preferably 0.5 to 7 mmol / g in any of the polymer forms.
Only 1 type of binder may be used for a resin composition, and 2 or more types may be used together.
The binder used in the present invention preferably has a weight average molecular weight of 5,000 to 1,000,000, more preferably 8,000 to 750,000, and 10,000 to 500,000. Most preferably it is. In addition, the weight average molecular weight of a binder is the value of polystyrene conversion by GPC measurement.
The preferred content of the specific polymer in the resin composition that can be used in the present invention is 2 to 95% by weight in the total solid content from the viewpoint of satisfying a good balance of form retention, water resistance and engraving sensitivity of the coating film. It is preferably 5 to 80% by weight, particularly preferably 10 to 60% by weight.
The content of the binder polymer is preferably 5 to 95% by weight, more preferably 15 to 80% by weight, and still more preferably 20 to 65% by weight based on the total solid content of the resin composition.
By making the content of the binder polymer 5% by weight or more, printing durability sufficient to use the obtained printing plate as a printing plate can be obtained, and by making it 95% by weight or less, other components are insufficient. Therefore, even when the printing plate is a flexographic printing plate, the flexibility sufficient for use as the printing plate can be obtained.

(solvent)
In the present invention, the solvent used for preparing the resin composition is preferably mainly an aprotic organic solvent from the viewpoint of promptly proceeding the reaction between the compound (I) and the specific polymer. More specifically, it is preferable to use an aprotic organic solvent / protic organic solvent in a weight ratio of 100/0 to 50/50. More preferably, it is 100/0 to 70/30, and particularly preferably 100/0 to 90/10.
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 and dimethyl sulfoxide.
Preferred specific examples of the protic organic solvent are methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 1-methoxy-2-propanol, ethylene glycol, diethylene glycol, and 1,3-propanediol.

(Polymerization initiator)
It is preferable that a resin composition contains a polymerization initiator, and it is more preferable to use the compound which has an ethylenically unsaturated group, and a polymerization initiator together.
A well-known thing can be used for a polymerization initiator without a restriction | limiting. 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.
The polymerization initiator can be roughly classified into a photopolymerization initiator and a thermal polymerization initiator.
As the photopolymerization initiator, those described above can be suitably used.

In the present invention, a thermal polymerization initiator is preferably used from the viewpoint of improving the degree of crosslinking. As the thermal polymerization initiator, organic peroxides and azo compounds are preferably used, and organic peroxides are more preferably used. In particular, the following compounds are preferred.

As a radical polymerization initiator that can be used in the present invention, preferred organic peroxides include 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-isopropylcumylperoxycarbonyl) benzophenone, di-t-butyldiperoxyisophthalate Peroxyesters such as t-butyl peroxybenzoate are preferred.

As a radical polymerization initiator that can be used in the present invention, preferred azo compounds include 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-methylpropionamidooxime), 2,2 '-Azobis [2- (2-imidazolin-2-yl) propane], 2,2'-azobis {2-methyl-N- [1,1-bis (hydroxymethyl) -2-hydride Xylethyl] 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.

The polymerization initiator in the present invention may be used alone or in combination of two or more.
The polymerization initiator can be added in a proportion of preferably 0.01 to 10% by weight, more preferably 0.1 to 3% by weight, based on the total solid content of the resin composition.

(Photothermal conversion agent)
The resin composition preferably contains a photothermal conversion agent.
It is considered that the photothermal conversion agent absorbs laser light and generates heat, thereby accelerating thermal decomposition of a cured layer that is a cured product of the resin composition, that is, a recording layer. Therefore, it is preferable to select a photothermal conversion agent that absorbs light having a laser wavelength used for engraving.

When a laser emitting an infrared ray having a wavelength of 700 nm to 1,300 nm, for example, a YAG laser, a semiconductor laser, a fiber laser, a surface emitting laser or the like is used as a light source for laser engraving, the recording layer in the present invention has a recording layer of 700 nm to 1,300 nm. It is preferable to contain the photothermal conversion agent which can absorb the light of this wavelength.
Various dyes and / or pigments are used as the photothermal conversion agent in the present invention.
The photothermal conversion agent is more preferably at least one photothermal conversion agent selected from pigments and dyes having absorption at 800 nm to 1,200 nm.
The photothermal conversion agent is preferably a pigment.

Among the photothermal conversion agents, as the dyes, 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 in the range of 700 nm to 1,300 nm. Azo dyes, metal complex salt azo dyes, pyrazolone azo dyes, naphthoquinone dyes, anthraquinone dyes, phthalocyanine dyes, carbonium dyes, diimmonium compounds, quinone imine dyes , Methine dyes, cyanine dyes, squarylium dyes, pyrylium salts, and metal thiolate complexes. In particular, cyanine dyes such as heptamethine cyanine dye, oxonol dyes such as pentamethine oxonol dye, and phthalocyanine dyes are preferably used. Examples thereof include the dyes described in paragraphs 0124 to 0137 of JP-A-2008-63554.

Among the photothermal conversion agents used in the present invention, as pigments, commercially available pigments and color index (CI) manuals, edited by Japan Pigment Technical Association, “Latest Pigment Manual”, published in 1977, published by CMC, The pigments described in “Latest Pigment Applied Technology”, published in 1986, CMC Publishing, “Printing Ink Technology”, published in 1984 can be used.

Examples of pigments include black pigments, yellow pigments, orange pigments, brown pigments, red pigments, purple pigments, blue pigments, green pigments, fluorescent pigments, metal powder pigments, and other polymer-bonded dyes. Specifically, insoluble azo pigments, azo lake pigments, condensed azo pigments, chelate azo pigments, phthalocyanine pigments, anthraquinone pigments, perylene and perinone pigments, thioindigo pigments, quinacridone pigments, dioxazine pigments, isoindolinone pigments In addition, quinophthalone pigments, dyed lake pigments, azine pigments, nitroso pigments, nitro pigments, natural pigments, fluorescent pigments, inorganic pigments, carbon black, and the like can be used. Of these pigments, carbon black is preferred.

As long as the dispersibility in the composition is stable, the carbon black can be used regardless of the application such as color, rubber, and dry battery, in addition to the classification by ASTM. Carbon black includes, for example, furnace black, thermal black, channel black, lamp black, acetylene black and the like. In addition, black colorants such as carbon black can be used as color chips or color pastes previously dispersed in nitrocellulose or the like by using a dispersant as required in order to facilitate dispersion. Chips and pastes are easily available as commercial products.
In the present invention, it is also possible to use carbon black having a relatively low specific surface area and relatively low DBP absorption and even finer carbon black having a large specific surface area. Examples of suitable carbon blacks include Printex® U, Printex® A, or Specialschwarz® 4 (Degussa).
The carbon black that can be used in the present invention preferably has a dibutyl phthalate (DBP) oil absorption of less than 150 ml / 100 g.
Further, as the carbon black, conductive carbon black having a specific surface area of at least 150 m ² / g is preferable from the viewpoint of improving engraving sensitivity by efficiently transferring heat generated by photothermal conversion to surrounding polymers. .

The content of the photothermal conversion agent in the recording layer or the resin composition varies greatly depending on the molecular extinction coefficient inherent to the molecule, but is 0.01 to 20 of the total solid weight of the resin composition or the recording layer. The range of wt% is preferred, the range of 0.05 to 10 wt% is more preferred, and the range of 0.1 to 5 wt% is particularly preferred.

(Plasticizer)
Moreover, it is preferable that the recording layer of the printing plate precursor for laser engraving used in the present invention and the resin composition contain a plasticizer.
The plasticizer has a function of softening a film formed of the resin composition, and by adding a plasticizer, printing that requires flexibility of the film of the produced printing plate, for example, soft packaging It can be used for various applications such as printing on a medium.

Here, when a plasticizer is added, the decomposition product generated when laser engraving is performed becomes a liquid viscous product.
When such a viscous material is collected using a conventional activated carbon filter or a filter having zeolite attached to the surface, these filters are deteriorated in a short time.
In contrast, in the production method of the present invention, the generated decomposition product is brought into contact with an alkaline aqueous solution. Thereby, the decomposition product can be dissolved or finely dispersed in an aqueous solution, and even a liquid viscous product can be easily collected, and thus can be suitably used.

The plasticizer needs to be compatible with the polymer.
As the plasticizer, for example, dioctyl phthalate, didodecyl phthalate, tributyl citrate and the like, polyethylene glycols, polypropylene glycol (monool type and diol type), polypropylene glycol (monool type and diol type) and the like are preferably used. .

(Other additives)
The recording layer of the resin composition and the printing plate precursor for laser engraving may contain known additives in addition to those described above.
More preferably, the resin composition is added with nitrocellulose or a highly thermally conductive substance as an additive for improving engraving sensitivity. Since nitrocellulose is a self-reactive compound, it generates heat during laser engraving and assists in the thermal decomposition of coexisting polymers such as hydrophilic polymers. As a result, it is estimated that the engraving sensitivity is improved. The highly heat conductive material is added for the purpose of assisting heat transfer, and examples of the heat conductive material include inorganic compounds such as metal particles and organic compounds such as a conductive polymer. As the metal particles, gold fine particles, silver fine particles, and copper fine particles having a particle size of micrometer order to several nanometer order are preferable. As the conductive polymer, a conjugated polymer is particularly preferable, and specific examples include polyaniline and polythiophene.
Moreover, the sensitivity at the time of photocuring a resin composition can be further improved by using a co-sensitizer.
Furthermore, it is preferable to add a small amount of a thermal polymerization inhibitor in order to prevent unnecessary thermal polymerization of the polymerizable compound during the production or storage of the composition.
For the purpose of coloring the resin composition, a colorant such as a dye or pigment may be added. Thereby, properties such as the visibility of the image portion and the suitability of the image density measuring device can be improved.
Furthermore, you may add well-known additives, such as a filler, in order to improve the physical property of the cured film of a resin composition.

[Printed version]
From the viewpoint of satisfying various printability such as abrasion resistance and ink transferability, the thickness of the relief layer, that is, the cured layer of the produced printing plate is preferably 0.05 mm or more and 10 mm or less. 05 mm or more and 7 mm or less are more preferable, and 0.05 mm or more and 3 mm or less are particularly preferable.

Moreover, it is preferable that the Shore A hardness of the relief layer which the produced printing plate has is 50 degree or more and 90 degrees or less. When the Shore A hardness of the relief layer is 50 ° or more, even if the fine halftone dots formed by engraving are subjected to the strong printing pressure of the relief printing press, they do not collapse and can be printed normally. In addition, when the Shore A hardness of the relief layer is 90 ° or less, it is possible to prevent faint printing in a solid portion even in flexographic printing with a printing pressure of kiss touch.
In addition, the Shore A hardness in the present specification is a durometer in which an indenter called a push needle or an indenter is pushed and deformed on the surface of the object to be measured, and the amount of deformation, that is, the depth of pushing, is measured and digitized. It is a value measured by a spring type rubber hardness tester.
Moreover, the printing plate produced by the production method of the present invention is particularly suitable for printing with water-based ink by a flexographic printing machine, but water-based ink and UV ink by a letterpress printing machine, any of the inks used, Printing is possible, and printing with UV ink by a flexographic printing machine is also possible.

[Collection step S102]
The collection step S102 is a step of collecting decomposition products generated when laser engraving is performed in the laser engraving step S100, a suction step S104 for sucking and collecting the generated decomposition products, and the collected decomposition products And a processing step S106 for processing the product by bringing it into contact with an alkaline aqueous solution.

[Suction process S104]
The suction step S104 is a step of sucking and collecting the decomposition products generated in the laser engraving step S100 and supplying them to the processing step S106.
There is no particular limitation on the method for sucking and collecting the decomposition products in the suction step S104, and various known suction methods can be used.

As an example, in the laser engraving machine 110 shown in FIG. 2, the spray nozzle 116 and the suction hood 118 are disposed in the vicinity of the exposure head 114 so as to sandwich the optical path of the laser emitted from the exposure head 114.

The spray nozzle 116 blows air in a direction orthogonal to the optical axis of the laser beam emitted from the exposure head 114 during laser engraving, and decomposes gas, ablation debris, dust, etc. generated from the printing plate precursor F during laser engraving by airflow. Blow off the product.
On the other hand, the suction hood 118 sucks the decomposition product blown off by the air flow together with the air blown from the spray nozzle 116. The suction hood 118 is connected to the dust collector 100 via a pipe 120, and supplies exhaust gas containing the sucked decomposition product to the processing device 10 of the dust collector 100.

The suction amount of the suction hood 118 is preferably larger than the supply amount of air from the spray nozzle 116 and several times.
The spray nozzle 116 blows air in a direction orthogonal to the optical axis of the laser beam. However, the present invention is not limited to this, and air is blown toward the exposure point of the laser beam of the printing plate precursor F. Also good.

[Processing step S106]
The processing step S106 is a step of collecting decomposition products by bringing the exhaust gas sucked and collected in the suction step S104 into contact with an alkaline aqueous solution.
As described above, the decomposition product generated from the printing plate precursor F during laser engraving is brought into contact with an alkaline aqueous solution, so that the decomposition product is dissolved or finely dispersed in the aqueous solution, so that the decomposition product can be easily obtained. Can be collected. Moreover, since a gas component can also be collected by making it contact with aqueous solution, the gas component of a decomposition product and a viscous thing, ie, a solid substance, can be collected efficiently at once.

The method of bringing the decomposition product into contact with the alkaline aqueous solution is not particularly limited, and can be carried out using an exhaust gas cleaning device called a so-called scrubber. The alkaline aqueous solution is sprayed to the filler using a spray nozzle and inhaled. A method of removing decomposition products from the exhaust gas, a method of spraying an alkaline aqueous solution simply using a spray nozzle, or aspirating and mixing exhaust gas together with liquid from a nozzle in the alkaline aqueous solution, and the decomposition products at the gas-liquid interface A method of adsorbing, a method of spraying an alkaline aqueous solution using a spray nozzle in a duct in which a spiral blade having a right twist and a left twist having a hole is arranged can be used.

An example of a processing apparatus that performs the processing step S106 is shown in FIG.
The processing apparatus 10 shown in FIG. 3 includes a hollow scrubber tower 12, a circulation tank 14 disposed vertically below the scrubber tower 12, a gas inlet 16 disposed on a lower side surface of the scrubber tower 12, and a circulation tank 14. A shower nozzle 18 disposed in the scrubber tower 12 above the vertical, a pump 20 disposed in a pipe connecting the circulation tank 14 and the shower nozzle 18, and the shower nozzle 18 and the circulation tank above the gas inlet 16. 14 has two fillers 22 arranged in the space between them and a gas outlet 24 arranged in the upper part of the scrubber tower 12. The filler 22 is a porous body such as ceramics, metal, rubber, or thermoplastic resin.

The processing apparatus 10 sucks the exhaust gas supplied from the gas inlet 16 connected to the pipe 120 by the dust collector main body 104 via the gas outlet 24 at the upper part of the scrubber tower 12 and raises the inside of the scrubber tower 12. Further, the processing apparatus 10 sprays an alkaline aqueous solution onto the filler 22 from the shower nozzle 18 at the top of the scrubber tower 12. The sprayed alkaline aqueous solution stays in the filler 22 and comes into contact with the exhaust gas rising in the scrubber tower 12. The alkaline aqueous solution dropped from the filler 22 is accumulated in the circulation tank 14 disposed at the lower part of the scrubber tower 12 and is circulated again to the shower nozzle 18 by the pump 20.
As described above, in the processing apparatus 10, the alkaline aqueous solution is sprayed on the filler 22 using the shower nozzle 18, and the inhaled exhaust gas and the alkaline aqueous solution are brought into contact with each other, thereby collecting decomposition products generated during laser engraving. To do.
The treated gas from which the decomposition products have been removed is sucked into the dust collector main body 104 and further subjected to a predetermined treatment as necessary, and then exhausted from the pipe 130.
The dust collector body 104 is not particularly limited, and various known dust collector bodies can be used.

FIG. 4 shows another example of the processing apparatus that performs the processing step S106.
The processing apparatus 40 shown in FIG. 4 includes a gas inlet 42, a guide plate 46 that extends in the vertical vertical direction in the vicinity of the gas inlet 42, and a nozzle that is horizontally arranged at the lower end of the guide plate 46. 48, on the outlet side of the nozzle 48, a guide plate 50 disposed substantially parallel to the guide plate 46, a draining plate 52 disposed above the guide plate 50, and a gas outlet 54 disposed above the apparatus. Have.
Further, an alkaline aqueous solution is stored in a lower part of the processing apparatus 40 up to a position where the nozzle 48 is immersed.

The processing device 40 sucks the exhaust gas supplied from the gas inlet 42 from the gas outlet 54, guides the exhaust gas entering from the gas inlet 42 to the nozzle 48 along the guide plate 46, and causes the nozzle 48 narrowed at the liquid level to flow. The exhaust gas is brought into contact with the alkaline aqueous solution by being wound together with the alkaline aqueous solution by passing at a high speed, and forming a vortex in the space between the guide plate 46 and the guide plate 50 to cause gas-liquid mixing. A large amount of the aqueous solution wound up collides with the draining plate 52 and falls. The treated gas that has passed between the guide plate 50 and the draining plate 52 is discharged from the gas outlet 54.

As described above, in the processing apparatus 40, the decomposition products generated during laser engraving are collected by sucking and mixing the exhaust gas together with the liquid from the nozzle in the alkaline aqueous solution.

Here, in the processing apparatus 40 shown in FIG. 4, it is preferable to generate cavitation in the alkaline aqueous solution immediately before the entrance of the nozzle 48. As a method for generating cavitation, a conventionally known ultrasonic generator can be used.
By generating cavitation, the bubble size of the exhaust gas when passing through the nozzle 48 can be reduced. Therefore, the contact area between the exhaust gas and the alkaline aqueous solution can be increased, and the collection efficiency of the decomposition product (solid matter, gas) can be improved.

(Alkaline aqueous solution)
The alkaline aqueous solution used in the treatment step S106 is not particularly limited as long as the pH is 9 or more. For example, an alkaline metal or alkaline earth metal such as a sodium hydroxide aqueous solution, a potassium hydroxide aqueous solution, or a sodium hypochlorite aqueous solution is used. A hydroxide or the like can be used.
In addition, from the viewpoint of the collection rate of decomposition products, the pH is preferably 10 or more, and more preferably 12 or more.

In addition, it is preferable that a surfactant and / or an antifoaming agent is added to the alkaline aqueous solution.

(Surfactant)
The surfactant is not particularly limited, and various known surfactants can be used. In particular, it is preferable to use a betaine-type, sulfobetaine-type, or alkylbetaine-type amphoteric surfactant as the surfactant.
By adding a surfactant to the alkaline aqueous solution, bubbles are easily generated, so that the contact area between the decomposition product and the alkaline aqueous solution can be increased, and the solid collection efficiency of the decomposition product is improved. can do.
Further, by containing a surfactant in the alkaline aqueous solution, the dissolved or finely dispersed decomposition product can be kept in the state of fine particles, and the dispersibility can be enhanced.
Since the alkaline aqueous solution is circulated and used as in the processing apparatus shown in FIGS. 3 and 4, when the dissolved decomposition products are aggregated and solidified in the alkaline aqueous solution, the piping cannot be circulated due to clogging. May cause problems. Therefore, by adding a surfactant and enhancing the dispersibility of the decomposition product, the above problem can be suppressed and the alkaline aqueous solution can be circulated and used.

(Defoamer)
The antifoaming agent is not particularly limited, and various known antifoaming agents can be used. In particular, it is preferable to use a silicone-based antifoaming agent as the antifoaming agent.
By adding an antifoaming agent to the alkaline aqueous solution containing the surfactant, the foam is broken by breaking the order of the surface active molecules. As a result, the contact area between the gas and the alkaline aqueous solution increases, and in particular, the gas component collection efficiency can be improved.

In the present invention, the processed gas processed in the processing step S106 may be processed using another dust collection system.
For example, as a collection method, a known method such as a combustion method, a wet electrostatic precipitating method, a centrifugal separation method, an adsorption method, a cyclone method, a filter method, an ozone oxidation method, a biological deodorization method, a plasma deodorization method, or a photocatalyst method is used. The treated gas may be treated.

Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these.

<Example 1>
[Laser engraving printing plate precursor]
First, the printing plate precursor F for laser engraving used in Example 1 will be described.
(Resin composition)
Denkabutyral # 3000-2: Polyvinyl butyral (Mw = 90,000, manufactured by Denki Kagaku Kogyo Co., Ltd.) as a binder polymer in a three-necked flask equipped with a stirring blade and a condenser tube was added to the total solid content. 73 wt% and PGMEA as a solvent were added and heated at 70 ° C. for 180 minutes with stirring to dissolve the polymer.
Thereafter, HDDA: hexanediol diacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.) as a polyfunctional monomer was 10% by weight based on the total weight of the solid content, and perbutyl Z: t-butyl peroxybenzoate (NOF) as a polymerization initiator. Co., Ltd.) is 2% by weight based on the total weight of the solid content, and carbon black (trade name: # 45L, manufactured by Mitsubishi Chemical Corporation) is added as a photothermal conversion agent at 15% by weight based on the total weight of the solid content. Stir for minutes. By this operation, a fluid resin layer coating solution was obtained. Hereinafter, this coating solution for a resin layer is referred to as a resin composition A.

(Curing of hardened layer)
A spacer frame having a predetermined thickness is placed on a PET substrate, and the resin composition A obtained as described above is gently poured and heated in an oven at 80 ° C. for 3 hours and further at 120 ° C. for 3 hours to remove the solvent. The resin composition was thermally crosslinked to obtain a cured layer having a thickness of 1.14 mm, that is, a recording layer.

(Lamination with support)
After coating the adhesive composition described below to a thickness of 120 μm on the cured layer obtained by forming a film, a 0.23 mm thick PET support was laminated with a nip roller, and after 20 seconds, the PET support side Then, the adhesive is cured at an exposure amount of 1,000 mJ / cm ² with a UV exposure machine (UV exposure machine ECS-151U manufactured by Igraphic Co., Ltd., metal halide lamp, 1,500 mJ / cm ² , 14 sec exposure), and printing plate precursor F Was made.
As an adhesive composition, 52 parts by mass of 2-hydroxypropyl acrylate (manufactured by Osaka Organic Chemical Co., Ltd.), 40 parts by mass of trimethylolpropane triacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.), 1-hydroxycyclohexyl phenyl ketone ( A mixture of 8 parts by mass of Ciba Specialty Chemicals Co., Ltd. was used.

[Laser engraving process]
Laser engraving is applied to the above printing plate precursor F for laser engraving using a carbon dioxide laser engraving machine (trademark: ZED-mini-1000, manufactured by ZED, equipped with a 2500 W carbon dioxide laser (produced by Coherent)). went. The sculpture was engraved on a solid portion of 5 m ² with a sculpture depth of 0.50 mm and a pitch setting of 2,400 DPI.

[Suction process]
Air is blown onto the laser engraving unit irradiated with the laser beam, and decomposition products generated in the laser engraving unit are discharged out of the carbon dioxide laser engraving machine by suction. The exhaust gas flow rate was 2 cubic meters per minute.

[Processing process]
The alkaline aqueous solution shown below is put in a 50 liter plastic container, a pipe having an outer diameter of 70 mm is inserted into the liquid, and the decomposition product sucked in the suction process is brought into contact with the alkaline aqueous solution through this pipe, and laser The decomposition products generated by engraving were collected.

(Alkaline aqueous solution)
As the alkaline aqueous solution, sodium hydroxide (NaOH, manufactured by Wako Pure Chemical Industries, Ltd.) was added to pure water to obtain a pH 9 sodium hydroxide aqueous solution.

[Solid collection rate]
About the decomposition | disassembly product collected as mentioned above, the collection rate of a viscous thing, ie, a solid substance, was evaluated.
Specifically, 20 mL of the alkaline aqueous solution after the treatment step was measured in a 50 mL eggplant flask, and the flask was immersed in liquid nitrogen. After the liquid was sufficiently frozen, lyophilization was performed under the conditions of 0.3 Torr and 12 h to volatilize the solvent component. The weight of the dried solid was obtained by subtracting the previously measured tare weight from the weight of the flask after lyophilization.
The solid matter collection rate was calculated from the amount of solid matter at the time of 100% collection when 5.0 m ^{2 was} engraved.
The solids collection rate was evaluated as AA: 80% or more, A: 50% or more, less than 80%, B: 30% or more, less than 50%, or C: 30. As a result, the evaluation was A.

[Gas collection rate]
Before and after the treatment step, the concentration of acetaldehyde contained in the gas was quantified, and the gas collection rate was calculated.
Before and after the treatment step, 1 L of sample gas was passed through a derivative cartridge (Sep-pak DNPH-Silica Plus Short Catridge) using a syringe to adsorb gas components. After elution of components through the cartridge through acetonitrile (Wako Pure Chemical Industries, Ltd.), the measured sample was used as a measurement sample, and the aldehyde concentration was measured using a high performance liquid chromatograph (Shimadzu Corporation).
Evaluation of gas collection rate is (aldehyde concentration after treatment step / aldehyde concentration before treatment step)
AA: Less than 20%, A: 20% or more, less than 50%, B: 50% or more, less than 70%, C: 70 or more. As a result, the evaluation was A.

[Dispersibility]
500 mL of the liquid after the treatment step was collected in a plastic container, and the dispersibility was evaluated from the liquid state over time.
Evaluation of dispersibility is as follows: AA: No sedimentation after 5 days, A: 3 days or more, partial sedimentation in less than 5 days, B: 1 day or more, partial sedimentation in less than 3 days, C: 1 day Less than, it was evaluated as partially sedimented. As a result, the evaluation was B.

<Example 2>
A laser engraving printing plate is produced in the same manner as in Example 1 except that the resin composition that is a material of the printing plate precursor F for laser engraving that performs laser engraving is changed to the resin composition B described below. The collection rate and dispersibility were evaluated. As a result of the evaluation, the solid collection rate was A, the gas collection rate was A, and the dispersibility was B.

(Resin composition B)
In a three-necked flask equipped with a stirring blade and a condenser tube, UBEPOL BR150: polybutadiene (manufactured by Ube Industries Co., Ltd.) as a binder polymer was 73% by weight with respect to the total solid content, and n-heptane was used as a solvent. And heated at 70 ° C. for 180 minutes with stirring to dissolve the polymer.
Thereafter, HDDA: hexanediol diacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.) as a polyfunctional monomer was 10% by weight based on the total weight of the solid content, and perbutyl Z: t-butyl peroxybenzoate (NOF) as a polymerization initiator. Co., Ltd.) is 2% by weight based on the total weight of the solid content, and carbon black (trade name: # 45L, manufactured by Mitsubishi Chemical Corporation) is added as a photothermal conversion agent at 15% by weight based on the total weight of the solid content. Stir for minutes. By this operation, a resin composition B, which is a fluid coating solution for the resin layer, was obtained.

<Example 3>
A laser engraving printing plate was produced in the same manner as in Example 1 except that the resin composition as the material of the laser engraving printing plate precursor F for performing laser engraving was changed to the resin composition C described below. The collection rate and dispersibility were evaluated. As a result of the evaluation, the solids collection rate was B, the gas collection rate was A, and the dispersibility was B.

(Resin composition C)
In a three-necked flask equipped with a stirring blade and a cooling tube, as a binder polymer, D-1102: polystyrene-polybutadiene-polystyrene (manufactured by Kraton Polymer Japan Co., Ltd.) is 73% by weight with respect to the total solid content, and a solvent. Then, cyclohexanone was added and heated at 70 ° C. for 180 minutes with stirring to dissolve the polymer.
Thereafter, HDDA: hexanediol diacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.) as a polyfunctional monomer was 10% by weight based on the total weight of the solid content, and perbutyl Z: t-butyl peroxybenzoate (NOF) as a polymerization initiator. Co., Ltd.) is 2% by weight based on the total weight of the solid content, and carbon black (trade name: # 45L, manufactured by Mitsubishi Chemical Corporation) is added as a photothermal conversion agent at 15% by weight based on the total weight of the solid content. Stir for minutes. By this operation, a resin composition C, which is a fluid coating liquid for the resin layer, was obtained.

<Example 4>
A laser engraving printing plate was produced and the collection rate and dispersibility were evaluated in the same manner as in Example 1 except that the content of sodium hydroxide was changed and the pH of the alkaline aqueous solution was set to 10. As a result of the evaluation, the solid collection rate was A, the gas collection rate was A, and the dispersibility was B.

<Example 5>
A laser engraving printing plate was produced in the same manner as in Example 1 except that the content of sodium hydroxide was changed and the pH of the alkaline aqueous solution was set to 12. The collection rate and dispersibility were evaluated. As a result of the evaluation, the solid matter collection rate was AA, the gas collection rate was A, and the dispersibility was B.

<Example 6>
A laser engraving printing plate was produced and the collection rate and dispersibility were evaluated in the same manner as in Example 2 except that the content of sodium hydroxide was changed and the pH of the alkaline aqueous solution was set to 12. As a result of the evaluation, the solid matter collection rate was AA, the gas collection rate was A, and the dispersibility was B.

<Example 7>
A laser engraving printing plate was produced and the collection rate and dispersibility were evaluated in the same manner as in Example 3 except that the content of sodium hydroxide was changed and the pH of the alkaline aqueous solution was set to 12. As a result of the evaluation, the solids collection rate was B, the gas collection rate was A, and the dispersibility was B.

<Example 8>
A laser engraving printing plate was produced in the same manner as in Example 1 except that the content of sodium hydroxide was changed and the pH of the alkaline aqueous solution was set to 14, and the collection rate and dispersibility were evaluated. As a result of the evaluation, the solid matter collection rate was AA, the gas collection rate was A, and the dispersibility was B.

<Example 9>
A laser engraving printing plate was produced in the same manner as in Example 5 except that the type of the alkaline aqueous solution was changed, and the collection rate and dispersibility were evaluated. As a result of the evaluation, the solid matter collection rate was AA, the gas collection rate was A, and the dispersibility was B.

(Alkaline aqueous solution)
The alkaline aqueous solution was prepared by adding potassium hydroxide (KOH, manufactured by Wako Pure Chemical Industries, Ltd.) to pure water to obtain a pH 12 aqueous potassium hydroxide solution.

<Example 10>
A laser engraving printing plate was produced in the same manner as in Example 5 except that the type of the alkaline aqueous solution was changed, and the collection rate and dispersibility were evaluated. As a result of the evaluation, the solid matter collection rate was AA, the gas collection rate was A, and the dispersibility was B.

(Alkaline aqueous solution)
In the alkaline aqueous solution, 1% by weight of sodium hypochlorite (NaClO, manufactured by Wako Pure Chemical Industries, Ltd.) was added to pure water. The pH was 12.

<Example 11>
Further, a laser engraving printing plate was produced in the same manner as in Example 5 except that 10% by weight of surfactant: Softazoline LPB-R (manufactured by Kawaken Fine Chemical Co., Ltd.) was added. Was evaluated. As a result of the evaluation, the solid collection rate was AA, the gas collection rate was B, and the dispersibility was A.

<Example 12>
Furthermore, a laser engraving printing plate was produced in the same manner as in Example 5 except that 30% by weight of surfactant: Softazoline LPB-R (manufactured by Kawaken Fine Chemical Co., Ltd.) was added. Was evaluated. As a result of the evaluation, the solids collection rate was AA, the gas collection rate was B, and the dispersibility was AA.

<Example 13>
Further, a laser engraving printing plate was produced in the same manner as in Example 5 except that 1% by weight of an antifoaming agent: TSA739 (manufactured by Tanac Co., Ltd.) was added, and the collection rate and dispersibility were evaluated. . As a result of the evaluation, the solid matter collection rate was AA, the gas collection rate was A, and the dispersibility was B.

<Example 14>
Further, in the same manner as in Example 5, except that 30% by weight of surfactant: Softazoline LPB-R (manufactured by Kawaken Fine Chemical Co., Ltd.) and 1% by weight of antifoaming agent: TSA739 (manufactured by Tanac Co., Ltd.) were added. The laser engraving printing plate was manufactured, and the collection rate and dispersibility were evaluated. As a result of the evaluation, the solid matter collection rate was AA, the gas collection rate was AA, and the dispersibility was AA.

<Example 15>
Except that the cavitation was generated by exciting the alkaline aqueous solution in the plastic container using an ultrasonic generator (Branson's throwing type ultrasonic vibrator, 40 kHz) during the treatment process. The laser engraving printing plate was manufactured, and the collection rate and dispersibility were evaluated. As a result of the evaluation, the solid matter collection rate was AA, the gas collection rate was AA, and the dispersibility was B.

<Example 16>
During the treatment process, the cavitation was generated by exciting the alkaline aqueous solution in the plastic container using an ultrasonic generator (Branson's throw-in type ultrasonic vibrator, 40 kHz). The laser engraving printing plate was manufactured, and the collection rate and dispersibility were evaluated. As a result of the evaluation, the solid matter collection rate was AA, the gas collection rate was AA, and the dispersibility was AA.

<Comparative Example 1>
In the treatment step, a laser engraving printing plate was produced in the same manner as in Example 1 except that water having a pH of 7 was used instead of the alkaline aqueous solution, and the collection rate and dispersibility were evaluated. As a result of the evaluation, the solid collection rate was C, the gas collection rate was A, and the dispersibility was B.

<Comparative example 2>
A laser engraving printing plate was produced in the same manner as in Example 1 except that the content of sodium hydroxide was changed and the pH of the alkaline aqueous solution was set to 8, and the collection rate and dispersibility were evaluated. As a result of the evaluation, the solid collection rate was C, the gas collection rate was A, and the dispersibility was B.

<Comparative Example 3>
In the treatment step, a laser engraving printing plate was produced in the same manner as in Example 1 except that a pH 8 microgel aqueous solution was used instead of the sodium hydroxide aqueous solution, and the collection rate and dispersibility were evaluated. . As a result of the evaluation, the solid collection rate was C, the gas collection rate was A, and the dispersibility was B.
In addition, the microgel aqueous solution used what diluted microgel (made by Calmore Co., Ltd.) 5 times with the pure water.

<Comparative example 4>
In the treatment step, a laser engraving printing plate was produced in the same manner as in Example 1 except that hydrochloric acid having a pH of 3 was used instead of the alkaline aqueous solution, and the collection rate and dispersibility were evaluated. As a result of the evaluation, the solid collection rate was C, the gas collection rate was A, and the dispersibility was B.
The hydrochloric acid was adjusted to a predetermined pH by adding HCl (manufactured by Wako Pure Chemical Industries, Ltd.) to pure water.

<Comparative Example 5>
In the treatment step, a laser engraving printing plate was produced in the same manner as in Example 1 except that hydrochloric acid having a pH of 1 was used instead of the alkaline aqueous solution, and the collection rate and dispersibility were evaluated. As a result of the evaluation, the solid collection rate was C, the gas collection rate was A, and the dispersibility was B.
The hydrochloric acid was adjusted to a predetermined pH by adding HCl (manufactured by Wako Pure Chemical Industries, Ltd.) to pure water.

<Comparative Example 6>
In the treatment step, a laser engraving printing plate was produced in the same manner as in Example 1 except that ethanol (EtOH, manufactured by Wako Pure Chemical Industries, Ltd.) was used instead of the alkaline aqueous solution, and the collection rate and dispersion were Sexuality was evaluated. As a result of the evaluation, the solid collection rate was C, the gas collection rate was C, and the dispersibility was C.

<Comparative Example 7>
In the treatment step, a laser engraving printing plate was produced in the same manner as in Example 2 except that ethanol (EtOH, manufactured by Wako Pure Chemical Industries, Ltd.) was used instead of the alkaline aqueous solution, and the collection rate and dispersion were Sexuality was evaluated. As a result of the evaluation, the solid collection rate was C, the gas collection rate was C, and the dispersibility was C.

<Comparative Example 8>
In the treatment step, a laser engraving printing plate was produced in the same manner as in Example 3 except that ethanol (EtOH, manufactured by Wako Pure Chemical Industries, Ltd.) was used instead of the alkaline aqueous solution, and the collection rate and dispersion were Sexuality was evaluated. As a result of the evaluation, the solid collection rate was C, the gas collection rate was C, and the dispersibility was C.
Table 1 shows the evaluation results of the examples and comparative examples.

From the results shown in Table 1, Examples 1 to 16 of the present invention in which decomposition products generated in laser engraving are collected by contacting with an alkaline aqueous solution having a pH of 9 or more are compared with Comparative Examples 1 to 8. It can be seen that the solids collection rate is improved.
Moreover, from the comparison of Examples 1, 4, 5, 8, 9, and 10, the higher the pH of the alkaline aqueous solution, the better the solids collection rate, and the pH is preferably 10 or more, and more preferably 12 or more. Recognize.
From the comparison of Examples 1 to 3 and 5 to 7, the solid plate collection rate is high in the case of a printing plate precursor using a material that generates a carbonyl group by an oxidation reaction such as polyvinyl butyral and polybutadiene as the main binder. It turns out that it is more suitable.

Moreover, it turns out that a dispersibility improves by adding surfactant to alkaline aqueous solution from the comparison of Example 5, 11, 12, 14.
Moreover, it turns out that the gas collection rate improves by adding a defoamer in addition to surfactant to alkaline aqueous solution from the comparison of Examples 12 and 14.
Moreover, it turns out that the gas collection rate improves by generating cavitation in alkaline aqueous solution from the comparison of Examples 5, 12, 15, and 16.
The effects of the present invention are clear from the above results.

DESCRIPTION OF SYMBOLS 10, 40 Processing apparatus 12 Scrubber tower 14 Circulation tank 16, 42 Gas inlet 18 Shower nozzle 20 Pump 22 Filler 24, 54 Gas outlet 46, 50, Guide plate 48 Nozzle 52 Drain plate 100 Dust collector 104 Dust collector main body 110 Laser engraving machine 112 Drum 114 Exposure head 116 Spray nozzle 118 Suction hood 120, 130 Piping

Claims (6)

1. A laser engraving step of laser engraving the cured layer of the printing plate precursor for laser engraving having one or more cured layers;
   And a collection step of collecting the decomposition product generated in the laser engraving step in contact with an alkaline aqueous solution having a pH of 9 or more.
2. The method for producing a laser engraving printing plate according to claim 1, wherein the hardened layer contains a material that generates a carboxyl group or a hydroxyl group by an oxidation reaction as a binder.
3. The method for producing a laser engraving printing plate according to claim 1 or 2, wherein the alkaline aqueous solution contains a surfactant.
4. The method for producing a laser engraving printing plate according to any one of claims 1 to 3, wherein the alkaline aqueous solution contains an antifoaming agent.
5. The collection step according to any one of claims 1 to 4, wherein the collection step collects the decomposition product by allowing the decomposition product and the alkaline aqueous solution to pass through a nozzle to be gas-liquid mixed. Manufacturing method of laser engraving printing plate.
6. The method for producing a laser engraving printing plate according to claim 5, wherein cavitation is generated in the alkaline aqueous solution in the collecting step.

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