JP4288123B2 - Photopolymerization planographic printing plate making machine - Google Patents

Description

  The present invention relates to a plate making method and a plate making apparatus for a photopolymerizable lithographic printing plate.

Conventionally, a method for making a lithographic printing plate as described in Patent Document 1 (Japanese Patent Application Laid-Open No. 2000-35673) is known. However, a photopolymerizable lithographic printing plate can be used depending on plate making conditions such as exposure and development. There was a problem that the point reproducibility fluctuated.
For example, when development processing is performed immediately after exposure, there is a phenomenon that a small dot reproduced at 3% (175 lines / inch) is reduced to 1% when development processing is performed 3 minutes after exposure.
It has been desired to stabilize halftone dot reproducibility in plate making of a photopolymerizable lithographic printing plate.
JP 2000-35673 A

The present invention provides a plate making apparatus for a photopolymerizable lithographic printing plate that enables stable and good halftone dot reproducibility.

The inventor of the present invention has found that halftone dot reproducibility can be improved by starting a heat treatment after a certain time after exposure in plate making of a photopolymerizable lithographic printing plate.
That is, the present invention relates to a method for making a photopolymerizable lithographic printing plate, characterized in that after the completion of latent image formation by light irradiation on a photopolymerizable lithographic printing plate having an oxygen blocking layer, heat treatment is started after a certain time. And an apparatus for forming a latent image by light on a photopolymerizable lithographic printing plate having an oxygen blocking layer and developing it to produce a lithographic printing plate until the heat treatment is started after the latent image formation is completed. A plate making apparatus capable of controlling time is provided.

In plate making of a photopolymerizable lithographic printing plate, fluctuations in halftone dot reproducibility in development processing immediately after exposure and after aging are considered as follows.
Immediately after the exposure, radicals generated in the photopolymerizable photosensitive layer at the time of exposure survive, and the remaining radicals contribute to the polymerization of the monomer even during heating in the developing portion, and thicken the halftone dots. On the other hand, over time, after exposure, oxygen in the atmosphere that permeates the oxygen blocking layer (OC layer) and dissolved oxygen in the photosensitive layer extinguishes radicals generated by exposure from the top of the small dots and from the side. I will let you. For this reason, even when heated in the developing section after the passage of time, the remaining radicals are few, the polymerization of the monomers does not proceed, and the halftone dots remain thin. In particular, since there are many unexposed portions around the small dots, there is a large amount of dissolved oxygen, and the reproducibility of the small dots is likely to deteriorate significantly.

Based on such a phenomenon, in the plate making method of the photopolymerizable lithographic printing plate having an oxygen blocking layer of the present invention, 30 seconds after completion of latent image formation by light irradiation on the photopolymerizable lithographic printing plate having an oxygen blocking layer. The method is characterized in that the heat treatment is started later, preferably after 30 to 210 seconds, more preferably after 45 to 180 seconds, and still more preferably after 60 to 150 seconds.
Completion of latent image formation means completion of light irradiation on the entire plate and completion of latent image formation on the entire plate. In the case of scanning exposure, completion of scanning corresponds to completion of latent image formation.
By taking a predetermined time after the latent image is formed and before the heat treatment is started, the concentration of radicals generated by exposure in the photosensitive layer of the printing plate after exposure is stabilized, and good halftone dot reproduction is achieved. And the obtained printing plate has a stable quality.

  Plate making from a photopolymerizable lithographic printing plate can be performed with good halftone dot reproducibility.

The plate-making method of the present invention is an apparatus for forming a lithographic printing plate by forming a latent image by light on a photopolymerizable lithographic printing plate having an oxygen blocking layer, and developing the latent image. The plate making apparatus can control the time until development is started.
Furthermore, the plate making apparatus of the present invention preferably has the following mechanism.
(A) A mechanism capable of selecting whether to delay by controlling the time until the heating process in the heating unit is started after the latent image formation is completed.
(B) A mechanism that can control the time from the completion of latent image formation to the start of heat treatment to 30 seconds or more.
(C) a mechanism for controlling the time from the completion of the latent image formation to the start of the heat treatment by waiting the plate in the standby unit during conveyance to the developing unit after completion of the latent image formation;
(D) The plate is detected by the sensor, the plate is stopped by the standby unit, and after a predetermined time has elapsed from the detection, the stop is released and the plate is sent to the developing unit to start the heating process after the latent image formation is completed. A mechanism to control the time until.

More specifically, the plate making apparatus of the present invention can be carried out, for example, by a plate making apparatus provided with an exposure unit, a buffer unit, a heating unit, and a developing unit.
In the plate making apparatus of the present invention, for example, as shown in FIG. 1, a plate is supplied from a plate feeding unit 1, an exposure unit 2 that performs exposure, and a photopolymerizable planographic printing plate (printing plate) after exposure is temporarily stored. It consists of a buffer unit 3, a heating unit 4 and a developing unit 5 that have a function / mechanism for holding for a specified time and carry them.

Hereinafter, the exposure unit, the buffer unit, the heating unit, and the developing unit will be described in detail.
[Exposure part]
The main components of the exposure unit are a laser light source, a laser beam scanning mechanism, a printing plate fixing mechanism during exposure, a printing plate loading / unloading mechanism, a data storage device, and a control device for these, control / monitoring / input / output There is a control panel for that.
The types of laser light sources are mainly classified by the oscillation wavelength, and there are light sources such as infrared rays, visible rays, and ultraviolet rays. In the present invention, visible rays and ultraviolet lasers are suitable.
The laser beam scanning mechanism includes a flat bed type, an inner drum type, an outer drum type, etc., depending on the fixed form of the printing plate as the object to be exposed. For example, the inner drum type has a printing plate mounted on the inner surface of a cylinder. The laser light source and the spinner mirror rotating at high speed are arranged on the central axis of the cylinder, and the spinner mirror is moved on the axis. At this time, by flashing the laser beam according to the image data, a latent image is formed on the printing plate and exposure is performed.
In these cases, there is generally a time difference of 30 to 120 seconds between the first exposed part and the last exposed part.
In the present invention, after the exposure of the last exposed portion of the plate (after completion of latent image formation), after 30 seconds or more, preferably after 30 to 210 seconds, more preferably after 45 to 180 seconds, still more preferably. After 60 to 150 seconds, the plate heat treatment is started. This time is preferably shorter from the viewpoint of productivity.

[Buffer part]
The control to set the time from the completion of latent image formation to the start of the heat treatment to the above-described predetermined time of 30 seconds or more can be performed by controlling the conveyance speed of the printing plate until the heat treatment after the exposure. It is preferable to control the conveying speed of the printing plate by providing a buffer portion between them.
As shown in FIG. 1, the buffer unit forms a space necessary for temporarily holding the printing plate between the exposure unit and the heating unit, and after the latent image formation is completed, the heating process is started. In consideration of time, the printing plate is kept in the buffer unit for a predetermined time (buffer time) by controlling the conveyance speed including stopping in the buffer unit, and after the buffer time has passed, the printing plate is introduced into the heating unit. Just do it.

The buffer time (time for which the printing plate exists in the buffer part) is determined by taking into account the time until the printing plate enters the buffer part after completion of latent image formation by exposure and the time from the buffer part to the start of heat treatment. The time from the completion of formation to the heat treatment is set to be 30 seconds or longer.
That is, the time from the completion of latent image formation to the heat treatment = the time until the printing plate enters the buffer portion after completion of the latent image formation by exposure + the time that the printing plate exists in the buffer portion (buffer time) + exit the buffer portion This is the time until the heat treatment starts.
Further, it goes without saying that it is possible to make a setting that does not take a buffer time in accordance with the case of using another type of printing plate that does not require a buffer time or when the exposure image does not require a buffer time.

An example of the structure of the buffer unit is shown in FIG. 2. A transport roll 7 for loading and unloading the printing plate is provided inside a box-like body 6 having an entrance for loading the printing plate from the exposure unit 2 and an outlet for unloading the printing plate to the heating unit 4. And / or the conveyance belt 8 is arrange | positioned, it connects with the drive motor 9, and a printing plate is conveyed.
A plate detection sensor 10 for detecting the leading edge of the printing plate is installed, and when the plate detection sensor 10 detects the leading edge of the printing plate, the signal is sent to the control device 11, and the control device 11 stops the drive motor 9 of the transport roll. It is only necessary to operate the timer and drive the drive motor 9 after a preset time has elapsed to resume conveyance. The control device 11 can be arranged in another control device such as an exposure unit.

  By passing through the buffer section at a predetermined transport speed, and stopping as necessary, the time from completion of latent image formation to the start of heat treatment is 30 seconds or more, preferably 30 to 210 seconds, more preferably It is controlled to 45 to 180 seconds, more preferably 60 to 150 seconds.

Further, when there is a marginal space near the exit of the exposure apparatus, it may be unloaded from the exposure drum after the exposure is completed and wait for the buffer time in the marginal space.
In this case, it is useful for saving the space of the entire apparatus. In this way, even if the next exposure operation is performed while waiting, the exposure drum is not occupied, so the plate-making efficiency is not lowered.
In addition, when there is no surplus space in the vicinity of the carry-out port of the exposure apparatus, it is possible to adopt a method in which the printing plate is allowed to stand on the exposure drum for a set buffer time.

[Heating section]
In the heating unit, the printing plate is heat-treated, for example, at a temperature of 50 ° C. to 150 ° C. (preferably 70 to 130 ° C., more preferably 80 to 120 ° C.) for 1 second to 5 minutes (preferably 3 seconds to 2 minutes). Further, more preferably 5 to 30 seconds), and a heating part before development in a general automatic developing machine corresponds to the heating part in the present invention. For example, the heating unit 13 in the automatic processor shown in FIG. 3 described later corresponds to the heating unit in the method of the present invention.

[Development part]
In the developing part, the unexposed part of the photopolymerizable photosensitive lithographic printing plate is removed with an alkali developer, but the developing part in a general automatic developing machine can be used. For example, the developing tank 15 in the automatic processor shown in FIG. 3 described later corresponds to the developing unit in the present invention.

An example of an automatic developing machine having a heating section and a developing section in the present invention is shown in FIG.
The automatic developing machine 12 for the photopolymerizable photosensitive lithographic printing plate comprises, for example, a heating part 13, a pre-washing tank 14, a developing tank 15, a washing tank 16, a gum tank 17, and a drying part 18 in this order.

The heating unit 13 is a heating process for 1 second to 5 minutes at a temperature of 50 ° C. to 150 ° C. for the purpose of increasing the curing rate of the photopolymerizable photosensitive layer between image exposure and development.
In the pre-water washing tank 14, the oxygen blocking layer of the photopolymerizable photosensitive lithographic printing plate is removed by washing with water. As the development process proceeds, the concentration of the water-soluble resin dissolved in the pre-water washing tank 14 increases, so that the dissolution and removal properties are inferior and waste is generated. Therefore, it is necessary to replenish water. In addition, when the power of the automatic processor 12 is turned on or off, water is volatilized spontaneously from the pre-washing tank 14, so that it is different from the processing amount of the photopolymerizable photosensitive lithographic printing plate. It is preferable to replenish the same amount of water as the volatilizing water.

  In the developing tank 15, the unexposed portion of the photopolymerizable photosensitive lithographic printing plate is removed with an alkali developer. In the present invention, the pH of the developing tank 15 is adjusted to an appropriate state by changing the replenishment amount of water, development replenishment stock solution, etc. according to the processing amount of the plate material of the photopolymerizable photosensitive lithographic printing plate. Can be maintained. In addition, when the power of the automatic processor 12 is turned on or off, the pH is naturally lowered by carbon dioxide gas in the atmosphere, so that the carbon dioxide is separated from the processing amount of the photopolymerizable photosensitive lithographic printing plate. It is preferable to perform replenishment for recovering the pH lowered by the gas to a constant level.

  In the water washing tank 16, the plate is washed with water for the purpose of removing the alkali developer remaining on the surface of the developed plate and reducing the amount of alkali solution brought into the gum bath 17 in the next step. When the power of the automatic developing machine 1 is turned on or off, it is preferable to replenish the same amount of water as the volatilized amount so as to compensate for the volatilized water naturally.

In the gum tank 17, the gum is applied and the alkaline resin is returned to the acid to suppress damage to the image area due to development and to prevent stains and scratches on the non-image area. If the automatic processor is turned on or off,
In order for water to volatilize naturally, it is preferable to replenish the same amount of water as the volatilized water separately from the processing amount of the photopolymerizable photosensitive lithographic printing plate.

[Other configurations]
In order to further improve the work efficiency, the plate-making apparatus is provided with a plate-feeding unit at the front stage of the exposure unit to sort / store at least one type of printing plate, and to remove the interleaf and make the plate-making operation. Sometimes it is preferable to have a function and mechanism for separating / removing predetermined printing plates one by one and supplying them to the exposure unit. When there is no plate feeding unit, the worker may supply the exposure apparatus one by one. Further, it is preferable that a stocker is usually provided at the subsequent stage of the developing section, and the printing plates after the development processing are accumulated.

  As for other configurations of the plate making apparatus, those in the conventional plate making apparatus can be applied as appropriate.

[Photopolymerizable planographic printing plate]
Next, the photopolymerizable lithographic printing plate used in the present invention will be described.
The photopolymerizable lithographic printing plate produced in the present invention is not particularly limited as long as it is a photopolymerizable lithographic printing plate having an oxygen blocking layer.
Hereinafter, preferred photopolymerizable lithographic printing plates will be described.

(Oxygen barrier layer)
The oxygen blocking layer is provided as a protective layer in order to prevent the photopolymerizable photosensitive layer from undergoing a polymerization inhibiting action due to oxygen.
A preferable oxygen barrier layer includes a protective layer containing at least polyvinyl alcohol.

  Polyvinyl alcohol includes polyvinyl alcohol and its partial esters, ethers, and acetals (collectively also referred to as polyvinyl alcohol derivatives), or a substantial amount of unsubstituted vinyl that makes them necessary water-soluble. Examples thereof include a copolymer containing an alcohol unit. Examples of polyvinyl alcohol include those having a hydrolysis degree of 71 to 100% and a polymerization degree in the range of 300 to 2400. Specifically, Kuraray Co., Ltd. PVA-105, PVA-110, PVA-117, PVA-117H, PVA-120, PVA-124, PVA-124H, PVA-CS, PVA-CST, PVA-HC, PVA- 203, PVA-204, PVA-205, PVA-210, PVA-217, PVA-220, PVA-224, PVA-217EE, PVA-220, PVA-224, PVA-217EE, PVA-217E, PVA-220E, PVA-224E, PVA-405, PVA-420, PVA-613, L-8, etc. are mentioned. Examples of the copolymer include polyvinyl acetate chloroacetate or propionate hydrolyzed 88 to 100%, polyvinyl formal and polyvinyl acetal and copolymers thereof, polyvinyl alcohol cation-modified with quaternary ammonium salt, sulfonic acid Examples include anion-modified with soda.

In some cases, a vinylpyrrolidone resin may be added.
The vinyl pyrrolidone resin may be a copolymer of vinyl pyrrolidone and other monomer components. Although it does not specifically limit as another monomer component, The thing similar to the compound which has the ethylenically unsaturated bond which can be addition-polymerized in the photopolymerizable photosensitive layer mentioned later is mentioned.
Specific examples of the vinylpyrrolidone-based resin used in the present invention include, for example, Rubitec VA 37E, 37I, 55I, 64P, 64W, 73E, 73W (above, manufactured by BSF Japan).

In the present invention, the vinylpyrrolidone-based resin has a weight average molecular weight of 10,000 to 500,000, preferably 15,000 to 200,000, and more preferably 20,000 to 100,000.
The ratio of the vinyl pyrrolidone resin to the total of the polyvinyl alcohol and the vinyl pyrrolidone resin is 0 to 20% by mass, more preferably 1 to 15% by mass.

As will be described later, the protective layer is provided on the photosensitive layer. Examples of the method for providing the protective layer include coating. In the case of coating, a solvent is generally used. The solvent used for coating is preferably water, but examples thereof include alcohols such as methanol and ethanol, and ketones such as acetone and methyl ethyl ketone mixed with water. The concentration of the solid content in the coating solution is suitably 1 to 20% by mass.
The protective layer of the present invention may further contain known additives such as a surfactant for improving the coating property and a water-soluble plasticizer for improving the physical properties of the film.
Examples of the water-soluble plasticizer include propionamide, cyclohexanediol, glycerin, sorbitol and the like. Further, a water-soluble (meth) acrylic polymer or the like may be added.
The coating amount is suitably in the range of about 0.1 / m ² to about 15 / m ² in terms of the mass after drying. More preferably, it is 1.0 / m ² to about 5.0 / m ² .

Next, the photopolymerizable photosensitive layer constituting the photopolymerizable lithographic printing plate of the present invention will be described. The photopolymerizable photosensitive layer is preferably composed of a photopolymerizable photosensitive layer composition containing the following components i) to iii).
i) At least one compound having addition-polymerizable ethylenically unsaturated bond ii) Photopolymerization initiator iii) Polymer binder

[Compound having an ethylenically unsaturated bond capable of addition polymerization]
The compound having an addition-polymerizable ethylenically unsaturated bond contained in the photopolymerizable photosensitive layer of the present invention has at least one, preferably two or more ethylenically unsaturated double bond groups as photopolymerization terminals. Any one of the compounds can be selected.
For example, it has a chemical form such as a monomer, a prepolymer, that is, a dimer, a trimer and an oligomer, or a mixture thereof and a copolymer thereof.
Examples of monomers and copolymers thereof include esters of unsaturated carboxylic acids (eg, acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid, etc.) with aliphatic polyhydric alcohol compounds, unsaturated Examples include amides of carboxylic acids and aliphatic polyvalent amine compounds.

  Specific examples of the monomer of an ester of an aliphatic polyhydric alcohol compound and an unsaturated carboxylic acid include acrylic acid esters such as ethylene glycol diacrylate, triethylene glycol diacrylate, 1,3-butanediol diacrylate, and tetramethylene glycol. Diacrylate, propylene glycol diacrylate, neopentyl glycol diacrylate, trimethylolpropane triacrylate, trimethylolpropane tri (acryloyloxypropyl) ether, trimethylolethane triacrylate, hexanediol diacrylate, 1,4-cyclohexanediol diacrylate , Tetraethylene glycol diacrylate, pentaerythritol diacrylate, pentaerythritol triacrylate , Pentaerythritol tetraacrylate, dipentaerythritol diacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, sorbitol triacrylate, sorbitol tetraacrylate, sorbitol pentaacrylate, sorbitol hexaacrylate, tri (acryloyloxyethyl) isocyanurate, Examples include polyester acrylate oligomers.

  Methacrylic acid esters include tetramethylene glycol dimethacrylate, triethylene glycol dimethacrylate, neopentyl glycol dimethacrylate, trimethylolpropane trimethacrylate, trimethylolethane trimethacrylate, ethylene glycol dimethacrylate, 1,3-butanediol dimethacrylate, Hexanediol dimethacrylate, pentaerythritol dimethacrylate, pentaerythritol trimethacrylate, pentaerythritol tetramethacrylate, dipentaerythritol dimethacrylate, dipentaerythritol hexamethacrylate, dipentaerythritol pentamethacrylate, sorbitol trimethacrylate, sorbitol tetramethacrylate, bis [p (3-methacryloxy-2-hydroxypropoxy) phenyl] dimethyl methane, bis - [p- (methacryloxyethoxy) phenyl] dimethyl methane.

  Itaconic acid esters include ethylene glycol diitaconate, propylene glycol diitaconate, 1,3-butanediol diitaconate, 1,4-butanediol diitaconate, tetramethylene glycol diitaconate, pentaerythritol diitaconate And sorbitol tetritaconate.

Examples of crotonic acid esters include ethylene glycol dicrotonate, tetramethylene glycol dicrotonate, pentaerythritol dicrotonate, and sorbitol tetradicrotonate.
Examples of isocrotonic acid esters include ethylene glycol diisocrotonate, pentaerythritol diisocrotonate, and sorbitol tetraisocrotonate.
Examples of maleic acid esters include ethylene glycol dimaleate, triethylene glycol dimaleate, pentaerythritol dimaleate, and sorbitol tetramaleate.
Furthermore, the mixture of the above-mentioned ester monomer can also be mention | raise | lifted.

Specific examples of amide monomers of aliphatic polyvalent amine compounds and unsaturated carboxylic acids include methylene bis-acrylamide, methylene bis-methacrylamide, 1,6-hexamethylene bis-acrylamide, 1,6-hexamethylene bis. -Methacrylamide, diethylenetriamine trisacrylamide, xylylene bisacrylamide, xylylene bismethacrylamide and the like.
As another example, the polyisocyanate compound having two or more isocyanate groups in one molecule described in JP-B-48-41708 contains a hydroxyl group represented by the following general formula (A). Examples thereof include a vinyl urethane compound containing two or more polymerizable vinyl groups in one molecule to which a vinyl monomer is added.
CH ₂ = C (Q ¹ ) COOCH ₂ CH (Q ² ) OH (A)
(However, Q ¹ and Q ² independently represent H or CH _3. )

  Further, urethane acrylates such as those described in JP-A-51-37193, JP-A-48-64183, JP-B-49-43191, JP-B-52-30490 are described. Polyfunctional acrylates and methacrylates such as polyester acrylates and epoxy acrylates obtained by reacting an epoxy resin with (meth) acrylic acid can be used. Furthermore, Journal of Japan Adhesion Association Vol. 20, no. 7, pages 300 to 308 (1984), those introduced as photocurable monomers and oligomers can also be used.

  Specifically, NK oligo U-4HA, U-4H, U-6HA, U-108A, U-1084A, U-200AX, U-122A, U-340A, U-324A, UA-100 (above, new Nakamura Chemical Co., Ltd.), UA-306H, AI-600, UA-101T, UA-101I, UA-306T, UA-306I (above, manufactured by Kyoeisha Yushi), Art Resin UN-9200A, UN-3320HA, UN-3320HB , UN-3320HC, SH-380G, SH-500, SH-9832 (manufactured by Negami Kogyo Co., Ltd.) and the like.

  In addition, the usage-amount of the compound which has these ethylenically unsaturated double bonds is 5-90 mass% of all the components of a photopolymerization photosensitive layer, Preferably it is used in the range of 10-80 mass%.

(Photopolymerization initiator)
Next, the photopolymerization initiator contained in the photopolymerizable photosensitive layer of the present invention will be described.
As the photopolymerization initiator contained in the photopolymerizable photosensitive layer of the photosensitive lithographic printing plate of the present invention, various photopolymerization initiators known in patents, literatures, etc., depending on the wavelength of the light source used, or 2 A combined system (photopolymerization initiation system) of two or more kinds of photopolymerization initiators can be appropriately selected and used. In the present invention, a system using a photopolymerization initiator used alone or two or more photopolymerization initiators is collectively referred to simply as a photopolymerization initiator or a photoinitiator.
For example, when light near 400 nm is used as a light source, benzyl, benzoyl ether, Michler's ketone, anthraquinone, thioxanthone, acridine, phenazine, benzophenone, and the like are widely used.

  Various photoinitiators have also been proposed in the case of using visible light of 400 nm or more, Ar laser, second harmonic of a semiconductor laser, or SHG-YAG laser as a light source, for example, US Pat. No. 2,850. 445, a certain photoreducible dye, such as rose bengal, eosin, erythrosine, or the like, or a combination of a dye and a photoinitiator, such as a complex initiator system of a dye and an amine (Japanese Patent Publication No. 44). -20189), a combination system of hexaarylbiimidazole, a radical generator and a dye (Japanese Patent Publication No. 45-37377), a system of hexaarylbiimidazole and p-dialkylaminobenzylidene ketone (Japanese Patent Publication No. 47-2528, No. 54-155292), a system of a cyclic cis-α-dicarbonyl compound and a dye (Japanese Patent Laid-Open No. 48-84183) Cyclic triazine and merocyanine dye systems (Japanese Patent Laid-Open No. 54-151024), 3-ketocoumarin and activator systems (Japanese Patent Laid-Open Nos. 52-111261, 58-15503), biimidazole, styrene derivatives, thiols System (Japanese Patent Laid-Open No. 59-140203), organic peroxide and dye system (Japanese Patent Laid-Open Nos. 59-1504, 59-140203, 59-189340, 62-62) No. 174203, Japanese Patent Publication No. 62-1641, US Pat. No. 4,766,055), dyes and active halogen compounds (Japanese Patent Laid-Open Nos. 63-178105, 63-258903, and 2-63054). Etc.), dye and borate compound systems (JP-A-62-143044, JP-A-62-1050242, JP-A-64-13140, JP-A-64-13141) JP-A-64-13142, JP-A-64-13143, JP-A-64-13144, JP-A-64-17048, JP-A-1-229003, JP-A-1-298348, JP-A-1 138204), dyes having a rhodanine ring and radical generators (Japanese Patent Laid-Open Nos. 2-179643 and 2-244050), titanocene and 3-ketocoumarin dyes (Japanese Patent Laid-Open No. 63-221110) , Titanocenes and xanthene dyes, and systems comprising addition-polymerizable ethylenically unsaturated compounds containing amino groups or urethane groups (JP-A-4-221958, JP-A-4-219756), systems of titanocene and specific merocyanine dyes (Japanese Patent Laid-Open No. 6-295061), a dye system having a titanocene and a benzopyran ring (Japanese Patent Laid-Open No. 8-3344897), etc. It can be mentioned.

A preferred photoinitiator is a combination using a cyanine-based, merocyanine-based, xanthene-based, ketocoumarin-based, or benzopyran-based pigment as the pigment, and a titanocene compound or a triazine compound as the initiator.
Preferred cyanine dyes include those having the following structure, but are not particularly limited.

(In the formula, Z ¹ and Z ² represent a group of nonmetallic atoms necessary for forming a benzimidazole or naphthimidazole ring, and may be the same or different. R ²⁴ , R ²⁵ , R ²⁶ and R ²⁷ represent Each represents an optionally substituted alkyl group, X ⁻ represents a counter anion, and n is 0 or 1.)

  Table 1 below shows specific examples of cyanine dyes.

  The merocyanine dye preferably has the following structure, but is not particularly limited.

(Wherein Z ¹ and Z ² each represent a nonmetallic atom group necessary for forming a 5-membered ring and / or a 6-membered nitrogen-containing heterocycle usually used in a cyanine dye. R ²⁸ and R ²⁹ are Each represents an alkyl group, wherein Q ¹ and Q ² are combined to form a 4-thiazolidinone ring, a 5-thiazolidinone ring, a 4-imidazolidinone ring, a 4-oxazolidinone ring, a 5-oxazolidinone ring, a 5-imidazolidinone ring, or A group of atoms necessary to form a 4-dithiolanone ring, L ¹ , L ² , L ³ , L ⁴ and L ⁵ each represents a methine group, m represents 1 or 2, i and h each represents 0 or .j represents .l is representing one or 2 1, k represents each 0, 1, 2 or 3 .X ^- represents a counter anion).

Wherein R ³⁰ and R ³¹ are each independently a hydrogen atom, alkyl group, substituted alkyl group, alkenyl group, substituted alkenyl group, alkynyl group, substituted alkynyl group, alkoxycarbonyl group, aryl group, substituted aryl group or aralkyl group. A represents an oxygen atom, a sulfur atom, a selenium atom, a tellurium atom, an alkyl or aryl-substituted nitrogen atom, or a dialkyl-substituted carbon atom, and X is necessary to form a nitrogen-containing hetero five-membered ring. Y represents a substituted phenyl group, an unsubstituted or substituted polynuclear aromatic ring, or an unsubstituted or substituted heteroaromatic ring, and Z represents a hydrogen atom, an alkyl group, a substituted alkyl group, an aryl Group, substituted aryl group, aralkyl group, alkoxy group, alkylthio group, arylthio group, substituted amino group An acyl group or an alkoxycarbonyl group,, Y and may be bonded to each other to form a ring.)

  Specific examples of merocyanine dyes are shown below.

  Examples of the xanthene dye include rhodamine B, rhodamine 6G, ethyl eosin, alcohol-soluble eosin, pyronin Y, and pyronin B.

  Ketocoumarin dyes preferably include those having the following structure, but are not particularly limited.

(In the formula, R ³² , R ³³ and R ³⁴ each represent a hydrogen atom, a halogen atom, an alkyl group or an alkoxy group, and R ³⁵ and R ³⁶ each represent an alkyl group, at least one of which has 4 to 16 carbon atoms. R ³⁷ represents a hydrogen atom, an alkyl group, an alkoxy group, an acyl group, a cyano group, a carboxyl group, or a group of an ester derivative or an amide derivative thereof; R ³⁸ represents a total number of carbon atoms of 3 to 3; Represents 17 heterocyclic residues -CO-R ³⁹ , R ³³ and R ³⁴ , R ³⁵ and R ³⁶ may be bonded to each other to form a ring, wherein R ³⁹ is a group shown below; .)

  Specific examples of ketocoumarin dyes are shown below.

  Preferred benzopyran dyes include those having the following structure, but are not particularly limited.

(In the formula, R ^{3 to} R ⁵ each independently represent a hydrogen atom, a halogen atom, an alkyl group, an aryl group, a hydroxyl group, an alkoxy group, or an amino group. Also, R ^{3 to} R ⁵ are bonded to each other. You may form the ring which consists of a nonmetallic atom with the carbon atom which can be formed.
R ⁷ represents a hydrogen atom, an alkyl group, an aryl group, a heteroaromatic group, a cyano group, an alkoxy group, a carboxy group, or an alkenyl group. R ⁵ is a group represented by R ⁷ or —Z—R ⁷ , and Z represents a carbonyl group, a sulfonyl group, a sulfinyl group or an arylene carbonyl group. R ⁷ and R ⁸ may both form a ring composed of a nonmetallic atom.
A represents O, S, NH, or a nitrogen atom having a substituent.
B is a group

G ₁ and G ₂ may be the same or different, and are a hydrogen atom, cyano group, alkoxycarbonyl group, aryloxycarbonyl group, acyl group, arylcarbonyl group, alkylthio group, arylthio group, alkylsulfonyl group, aryl Represents a sulfonyl group or a fluorosulfonyl group. However, G ₁ and G ₂ do not become hydrogen atoms at the same time. G ₁ and G ₂ may form a ring composed of a nonmetallic atom together with a carbon atom. )

  Specific examples of benzopyran dyes are shown below.

  Examples of the triazine compound as a photopolymerization initiator include compounds represented by the following formula.

(In the formula, Hal represents a halogen atom. Y ² represents —C (Hal) ₃ , —NH ₂ , —NHR ²¹ , —N (R ²¹ ) ₂ , —OR ²¹ , where R ²¹ represents an alkyl group. And a substituted alkyl group, an aryl group, and a substituted aryl group, and R ²⁰ represents —C (Hal) ₃ , an alkyl group, a substituted alkyl group, an aryl group, a substituted aryl group, and a substituted alkenyl group. .

  Specific examples of the triazine compound are shown below.

Moreover, a titanocene compound is mentioned as a preferable photoinitiator.
As the titanocene compound, for example, known compounds described in JP-A Nos. 59-152396 and 61-151197 can be appropriately selected and used.

  More specifically, di-cyclopentadienyl-Ti-di-chloride, di-cyclopentadienyl-Ti-bis-phenyl, di-cyclopentadienyl-Ti-bis-2,3,4,5 , 6-pentafluorophen-1-yl (hereinafter referred to as A-1), di-cyclopentadienyl-Ti-bis-2,3,5,6-tetrafluorophen-1-yl, di-cyclopenta Dienyl-Ti-bis-2,4,6-trifluorophen-1-yl, di-cyclopentadienyl-Ti-bis-2,6-difluorophen-1-yl, di-cyclopentadienyl- Ti-bis-2,4-difluorophen-1-yl, di-methylcyclopentadienyl-Ti-bis-2,3,4,5,6-pentafluorophen-1-yl (hereinafter referred to as A-2) ), Di-methyl Pentadienyl-Ti-bis-2,3,5,6-tetrafluorophen-1-yl, di-methylcyclopentadienyl-Ti-bis-2,4-difluorophen-1-yl, bis (cyclopentadi And enyl) -bis (2,6-difluoro-3- (pyridinyl) phenyl) titanium (hereinafter referred to as A-3).

  The concentration of these photopolymerization initiators in the photopolymerization layer of the photosensitive lithographic printing plate of the present invention is usually slight. Further, when the amount is inappropriately large, an unfavorable result such as blocking of an effective ray is produced. The amount of the photopolymerization initiator in the present invention is preferably used in the range of 0.01% by mass to 70% by mass with respect to the total of the binder component and the addition polymerizable monomer component. More preferably, good results are obtained at 1% to 50% by weight.

  Further, auxiliary agents such as amine compounds and thiol compounds may be added to the initiator, and particularly preferred are amine compounds and amino acids represented by the following general formula.

(In the formula, R ^{8 to} R ¹⁸ each represents an alkyl group.)

(In the formula, R ^{19 to} R ²² represent alkyl or alkoxy, R ²¹ and R ²² may form a ring, and R ²³ represents a heterocycle or alkylthio.)

(Wherein R ²⁸ and R ²⁹ are the same or different and each represents a hydrocarbon group which may have a substituent and may contain an unsaturated bond, or a heterocyclic group.
R ²⁶ and R ²⁷ are the same or different and are each a hydrogen atom, a hydrocarbon group which may have a substituent and may contain an unsaturated bond, a heterocyclic group, a hydroxyl group, a substituted oxy group, a mercapto group, a substituted group Represents a thio group. R ²⁶ and R ²⁷ are bonded to each other to form a ring, and —O—, —NR ²⁴ —, —O—CO—, —NH—CO—, —S—, and / or —SO ₂ — Represents an alkylene group having 2 to 8 carbon atoms, which may be contained in the main chain of the ring.
R ²⁴ and R ^{25 each} represents a hydrogen atom, a hydrocarbon group which may have a substituent and may contain an unsaturated bond, or a substituted carbonyl group. )

  In addition, dialkylbenzoic acid esters such as ethyl p-diethylaminobenzoate, bisaminobenzophenones such as 4,4′-bis (dimethylamino) benzophenone, bisaminobenzyl such as 4,4′-bis (diethylamino) benzyl,

N-phenylglycine, N-phenylglycine sodium salt can be mentioned.

[Polymer binder]
Next, the polymer binder contained in the photopolymerizable photosensitive layer of the present invention will be described.
The polymer binder contained in the photopolymerizable photosensitive layer of the present invention is soluble or swellable in alkaline water because it needs to be dissolved in an alkaline developer as well as a film-forming agent for the photosensitive layer. An organic polymer is used.
Examples of the organic polymer include various polymers. When water development is desired, for example, a water-soluble organic polymer is used. Examples of such an organic polymer include addition polymers having a carboxylic acid group in the side chain, such as JP 59-44615, JP-B 54-34327, JP-B 58-12577, JP-B 54-. No. 25957, JP 54-92723, JP 59-53836, JP 59-71048, ie, methacrylic acid copolymer, acrylic acid copolymer, itacon Cyclic acid anhydrides for acid copolymers, crotonic acid copolymers, maleic acid copolymers, partially esterified maleic acid copolymers, acidic cellulose derivatives having a carboxylic acid group in the side chain, and addition polymers having a hydroxyl group Products, polyvinyl pyrrolidone, polyethylene oxide, and alcohol-soluble polyamide or 2,2-bis- (4-hydride) that can increase the strength of the cured film Kishifeniru) - and a polyether of propane and epichlorohydrin.
Among these, [benzyl (meth) acrylate / (meth) acrylic acid / other addition polymerizable vinyl monomer as required] copolymer and [allyl (meth) acrylate / (meth) acrylic acid / as required Other addition polymerizable vinyl monomers] copolymers are particularly preferred.
Furthermore, JP-B-7-120040, JP-B-7-120041, JP-B-7-120042, JP-B-8-12424, JP-A-63-287944, JP-A-63-287947, JP-A-1 Polyurethane resins described in JP-A Nos. -271741 and JP-A No. 11-352691 can also be used in the application of the present invention.

  These polymer polymers can improve the strength of the cured film by introducing a radical reactive group into the side chain. Examples of functional groups capable of undergoing addition polymerization include ethylenically unsaturated bond groups, amino groups, and epoxy groups, and examples of functional groups that can become radicals upon irradiation with light include mercapto groups, thiol groups, halogen atoms, and triazines. Structure, onium salt structure and the like, and polar groups include a carboxyl group and an imide group. The functional group capable of addition polymerization is particularly preferably an ethylenically unsaturated bond group such as an acryl group, a methacryl group, an allyl group, or a styryl group, but an amino group, a hydroxy group, a phosphonic acid group, a phosphoric acid group, or a carbamoyl group. A functional group selected from a group, an isocyanate group, a ureido group, a ureylene group, a sulfonic acid group, and an ammonio group can also be used.

In order to maintain the developability of the photopolymerizable photosensitive layer, the polymer binder used preferably has an appropriate molecular weight and acid value, and has a weight average molecular weight of 5000 to 300,000 and an acid value of 20 to 200. Molecular polymers are particularly preferred.
These polymer binders can be contained in an arbitrary amount in the photopolymerizable photosensitive layer. However, when the content exceeds 90% by mass, there may be cases where favorable results are not obtained in terms of image strength to be formed. Therefore, Preferably it is 10-90 mass%, More preferably, it is 30-80 mass%.
Further, the use ratio of the compound having an ethylenically unsaturated double bond capable of addition polymerization and the polymer binder is preferably in the range of 1/9 to 9/1, more preferably 2/8. ˜8 / 2, most preferably 3/7 to 7/3.

  In addition, in the photopolymerizable photosensitive layer of the photopolymerizable lithographic printing plate of the present invention, in addition to the above basic components, an ethylenic polymer capable of addition polymerization during the production or storage of the composition for the photopolymerizable photosensitive layer. In order to prevent unnecessary thermal polymerization of a compound having an unsaturated bond, it is desirable to add a small amount of a thermal polymerization inhibitor. Suitable thermal polymerization inhibitors include hydroquinone, p-methoxyphenol, di-t-butyl-p-cresol, pyrogallol, t-butylcatechol, benzoquinone, 4,4'-thiobis (3-methyl-6-t- Butylphenol), 2,2'-methylenebis (4-methyl-6-t-butylphenol), N-nitrosophenylhydroxylamine cerium salt, N-nitrosophenylhydroxylamine aluminum salt and the like. The addition amount of the thermal polymerization inhibitor is preferably about 0.01% by mass to about 5% by mass of the total components of the photopolymerizable photosensitive composition. Also, if necessary, in order to prevent polymerization inhibition by oxygen, higher fatty acid derivatives such as behenic acid and behenamide are added and unevenly distributed on the surface of the photopolymerizable photosensitive layer in the process of drying after coating. You may let them. The amount of the higher fatty acid derivative added is preferably about 0.5% by mass to about 10% by mass of the total components of the photopolymerizable photosensitive composition.

Further, a colorant may be added for the purpose of coloring the photopolymerizable photosensitive layer. Examples of the colorant include phthalocyanine pigments (CI Pigment Blue 15: 3, 15: 4, 15: 6, etc.), azo pigments, pigments such as carbon black and titanium oxide, ethyl violet, crystal violet, There are azo dyes, anthraquinone dyes, and cyanine dyes. About 0.1 mass%-about 10 mass% of all the components of a photopolymerizable photosensitive composition are preferable, and, as for the addition amount of dye and a pigment, 0.5-5 mass% is more preferable.
In addition, in order to improve the physical properties of the cured film, an additive such as an inorganic filler or a plasticizer such as dioctyl phthalate, dimethyl phthalate, or tricresyl phosphate may be added. These additives are preferably 10% by mass or less based on the total components of the photopolymerizable photosensitive composition.
In addition, a surfactant can be added to the photopolymerizable photosensitive composition in order to improve the coating surface quality.

In the present invention, the photopolymerizable photosensitive composition is applied onto a support that has been subjected to various surface treatments as desired, which will be described in detail later. When coated on top, it is dissolved in various organic solvents for use. Solvents that can be used here include acetone, methyl ethyl ketone, cyclohexane, ethyl acetate, ethylene dichloride, tetrahydrofuran, toluene, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol dimethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether. , Acetylacetone, cyclohexanone, diacetone alcohol, ethylene glycol monomethyl ether acetate, ethylene glycol ethyl ether acetate, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether acetate, 3-methoxypropanol, methoxymethoxyethanol, diethylene glycol monomethyl ether , Diethylene glycol monoethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, 3-methoxypropyl acetate, N, N-dimethylformamide, dimethyl sulfoxide, γ-butyrolactone, methyl lactate, lactic acid There are ethyl and the like. These solvents can be used alone or in combination. In addition, 1-50 mass% is suitable for solid content concentration in a coating solution.
The coverage of the photopolymerizable photosensitive layer in the photopolymerizable planographic printing plate of the present invention, is suitably ranges from about 0.1 g / m ² ~ about 10 g / m ² in weight after coating and drying, and more preferably 0 .3 to 5 g / m ² , more preferably 0.5 to 3 g / m ² .

[Support]
Next, the support used in the present invention will be described.
As the support that can be used in the present invention, any material can be used as long as the surface is hydrophilic, but a dimensionally stable plate-like material is preferable, for example, paper, plastic (for example, polyethylene, polypropylene, polystyrene, etc. ) Laminated paper, and also metals such as aluminum (including aluminum alloys), zinc, copper etc. or alloys thereof (eg silicon, copper, manganese, magnesium, chromium, zinc, lead, bismuth, nickel Alloy) plates, and plastics such as cellulose diacetate, cellulose triacetate, cellulose propionate, cellulose butyrate, cellulose butyrate acetate, cellulose nitrate, polyethylene terephthalate, polyethylene, polystyrene, polypropylene, polycarbonate, polyvinyl acetal, etc. the film The above-described metal or alloy include laminated or vapor-deposited paper or plastic films. Of these supports, the aluminum plate is particularly preferred because it is dimensionally remarkably stable and inexpensive. Further, a composite sheet in which an aluminum sheet is bonded on a polyethylene terephthalate film as described in JP-B-48-18327 is also preferable. Usually, the thickness is about 0.05 mm to 1 mm.

Further, in the case of a support having a surface of metal, particularly aluminum, surface treatment such as graining treatment described later, immersion treatment in an aqueous solution of sodium silicate, potassium fluoride zirconate, phosphate or the like, or bipolar oxidation treatment, etc. It is preferable that
[Graining process]
Examples of the graining method include mechanical graining, chemical etching, and electrolytic grain as disclosed in JP-A-56-28893. Further, electrochemical graining method that electrochemically grains in hydrochloric acid or nitric acid electrolyte, and wire brush grain method that scratches aluminum surface with metal wire, and ball grain method that graines aluminum surface with polishing ball and abrasive. Further, a mechanical graining method such as a brush grain method in which the surface is grained with a nylon brush and an abrasive can be used, and the above graining methods can be used alone or in combination.
Among them, the method for making the surface roughness usefully used in the present invention is an electrochemical method in which the surface roughness is chemically ground in hydrochloric acid or nitric acid electrolyte, and a suitable current density is 100 C / dm ^{2 to} 400 C. / Dm ² range. More specifically, in the electrolytic solution containing from 0.1 to 50% hydrochloric acid or nitric acid, the temperature 20 to 100 ° C., for 1 second to 30 minutes, electrolysis at a current density of 100C / dm ² ~400C / dm ² It is preferable to carry out.

The grained aluminum support is chemically etched with acid or alkali. When an acid is used as an etching agent, it takes time to destroy the fine structure, which is disadvantageous when the present invention is applied industrially, but it can be improved by using an alkali as the etching agent.
Examples of the alkali agent suitably used in the present invention include caustic soda, sodium carbonate, sodium aluminate, sodium metasilicate, sodium phosphate, potassium hydroxide, lithium hydroxide and the like. The conditions are 50%, 20 to 100 ° C., and the aluminum dissolution amount is 5 to 20 g / m ³ .
After etching, pickling is performed to remove dirt (smut) remaining on the surface. Examples of the acid used include nitric acid, sulfuric acid, phosphoric acid, chromic acid, hydrofluoric acid, and borohydrofluoric acid. In particular, as a method for removing smut after the electrochemical surface roughening treatment, contact with 15 to 65 mass% sulfuric acid at a temperature of 50 to 90 ° C. as described in JP-A-53-12739 is preferable. And the alkali etching method described in Japanese Patent Publication No. 48-28123.
In addition, the surface roughness (Ra) of the aluminum support preferable in the present invention is 0.3 to 0.7 μm.

[Anodic oxidation treatment]
The aluminum support treated as described above is further anodized.
The anodizing treatment can be performed by a method conventionally performed in this technical field. Specifically, sulfuric acid, phosphoric acid, chromic acid, oxalic acid, sulfamic acid, benzenesulfonic acid, etc., or a combination of two or more of these, and when direct current or alternating current is applied to aluminum in an aqueous solution or non-aqueous solution, aluminum is supported. An anodized film can be formed on the body surface.
The conditions of the anodizing treatment cannot be determined unconditionally because they vary depending on the electrolytic solution used. In general, the concentration of the electrolytic solution is 1 to 80%, the liquid temperature is 5 to 70 ° C., the current density is 0.00. The range of 5 to 60 amperes / dm ² , voltage of 1 to 100 V, and electrolysis time of 10 to 100 seconds is appropriate.
Among these anodizing treatments, in particular, the method of anodizing at high current density in sulfuric acid described in British Patent 1,412,768, and US Pat. No. 3,511,661. A method of anodizing phosphoric acid described in the book as an electrolytic bath is preferred.
In the present invention, the anodized film is preferably from ^{1~10g / m 2, 1g / m} 2 less than the plate to easily enter the wound to be, requires significant power production exceeds 10 g / m ² It is economically disadvantageous. Preferably, it is 1.5-7 g / m < ² >, More preferably, it is 2-5 g / m < ² >.

  Furthermore, in the present invention, the support may be subjected to a sealing treatment after graining treatment and anodizing. Such sealing treatment is performed by immersing the substrate in a hot aqueous solution containing hot water and an inorganic salt or an organic salt, a steam bath, or the like. Further, the support used in the present invention may be subjected to a surface treatment such as a treatment other than a silicate treatment with an alkali metal silicate, for example, an immersion treatment in an aqueous solution of potassium fluoride zirconate, phosphate or the like.

  In the present invention, a photopolymerizable photosensitive layer comprising the above-mentioned photopolymerizable photosensitive composition is coated on a support (in the case of aluminum, aluminum that has been appropriately surface-treated as described above is preferable). Then, a protective layer is applied to form a photopolymerizable lithographic printing plate, but an organic or inorganic undercoat layer may be provided as necessary before applying the photopolymerizable photosensitive layer. Then, a sol-gel treatment in which a functional group capable of causing an addition reaction by a radical is disclosed as disclosed in JP-A-7-159983 may be applied.

Substances forming the organic undercoat layer include water-soluble resins such as polyvinylphosphonic acid, polymers and copolymers having sulfonic acid groups in the side chain, polyacrylic acid, water-soluble metal salts (for example, zinc borate) or , Yellow dyes, amine salts and the like.
More specifically, examples of the organic compound used in the organic undercoat layer may include phosphonic acids having an amino group such as carboxymethylcellulose, dextrin, gum arabic, and 2-aminoethylphosphonic acid, and a substituent. Organic phosphonic acids such as phenylphosphonic acid, naphthylphosphonic acid, alkylphosphonic acid, glycerophosphonic acid, methylenediphosphonic acid and ethylenediphosphonic acid, optionally substituted phenylphosphoric acid, naphthylphosphonic acid, alkylphosphoric acid and Organic phosphoric acids such as glycerophosphoric acid, optionally substituted phenylphosphinic acid, naphthylphosphinic acid, organic phosphinic acids such as alkylphosphinic acid and glycerophosphinic acid, amino acids such as glycine and β-alanine, and triethanol Has hydroxyl group such as amine hydrochloride -Alanine, and hydrochlorides of amines that may be used as a mixture of two or more.

This organic undercoat layer can be provided by the following method. That is, a method in which water or an organic solvent such as methanol, ethanol, methyl ethyl ketone or the like, or a mixed solvent thereof is dissolved on the support and dried, and water, methanol, ethanol, methyl ethyl ketone, etc. The organic compound is dissolved in a solution of the above organic compound or a mixed solvent thereof to immerse the support so that the organic compound is adsorbed, and then washed with water and dried to provide an organic undercoat layer. Is the method. In the former method, a solution having a concentration of 0.005 to 10% by mass of the above organic compound can be applied by various methods. For example, any method such as bar coater coating, spin coating, spray coating, or curtain coating may be used. In the latter method, the concentration of the solution is 0.01 to 20% by mass, preferably 0.05 to 5% by mass, the immersion temperature is 20 to 90 ° C., preferably 25 to 50 ° C., and the immersion time. Is 0.1 second to 20 minutes, preferably 2 seconds to 1 minute.
The solution used for this can be used in a pH range of 1 to 12 by adjusting the pH with a basic substance such as ammonia, triethylamine or potassium hydroxide, or an acidic substance such as hydrochloric acid or phosphoric acid. A yellow dye can also be added to improve the tone reproducibility of the photopolymerizable lithographic printing plate.
The coating amount after drying of the organic undercoat layer is suitably ² to 200 mg / m ² , preferably 5 to 100 mg / m ² . If the coating amount is less than 2 mg / m ² , sufficient printing durability cannot be obtained. It is the same even if it is larger than 200 mg / m ² .

  Examples of the material used for the inorganic undercoat layer include inorganic salts such as cobalt acetate, nickel acetate, and potassium fluorotitanate. The method of providing the inorganic undercoat layer is the same as the organic undercoat layer described above. .

[Exposure method]
The exposure of the photopolymerizable lithographic printing plate is performed using Ar laser, second harmonic of a semiconductor laser (SHG-LD, 350 to 600 nm), semiconductor laser (350 to 1000 nm), particularly 405 nm, 630, 650, 680, 785, 830. 860 nm, Ar laser 488, 514.5 nm, YAG laser 532 nm (second harmonic), 355 nm (third harmonic), 266 nm (fourth harmonic), He—Ne laser 543, 633 nm, etc.

[Development method]
As a developing solution used in the development processing, a conventionally known alkaline aqueous solution can be used. For example, sodium silicate, potassium, tribasic sodium phosphate, potassium, ammonium, dibasic sodium phosphate, potassium, ammonium, sodium carbonate, potassium, ammonium, sodium bicarbonate, potassium Examples include inorganic alkali agents such as ammonium, sodium borate, potassium, ammonium, sodium hydroxide, ammonium, potassium, and lithium. Moreover, monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine, triethylamine, monoisopropylamine, diisopropylamine, triisopropylamine, n-butylamine, monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, An organic alkali agent such as ethyleneimine, ethylenediamine, or pyridine may be used in combination.
These alkali agents are used alone or in combination of two or more.

Further, other surfactants described below may be added to the developer.
Examples of other surfactants include polyoxyethylene lauryl ether, polyoxyethylene cetyl ether, polyoxyethylene alkyl ethers such as polyoxyethylene stearyl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene nonyl phenyl ether, and the like. Polyoxyethylene alkyl allyl ethers, polyoxyethylene alkyl esters such as polyoxyethylene stearate, sorbitan monolaurate, sorbitan monostearate, sorbitan distearate, sorbitan monooleate, sorbitan sesquioleate, sorbitan trioleate Monoglyceride alkyl esters such as sorbitan alkyl esters such as glycerol, glycerol monostearate and glycerol monooleate Nonionic surfactants such as alkylbenzenes; alkylbenzene sulfonates such as sodium dodecylbenzenesulfonate; alkylnaphthalene sulfonates such as sodium butylnaphthalenesulfonate, sodium pentylnaphthalenesulfonate, sodium hexylnaphthalenesulfonate, sodium octylnaphthalenesulfonate Anionic surfactants such as alkyl sulfates such as sodium lauryl sulfate, alkyl sulfonates such as sodium dodecyl sulfonate, sulfosuccinic acid ester salts such as sodium dilauryl sulfosuccinate; alkyl betaines such as lauryl betaine and stearyl betaine; Amphoteric surfactants such as amino acids can be used, but anionic surfactants such as alkylnaphthalene sulfonates, alkyls are particularly preferable. Tines such a nonionic surfactant having a polyoxyalkylene ether group represented by the formula (1).

R ¹ —O— (R ² —O) n H (1)

In Formula (1), R ¹ represents an alkyl group having 3 to 15 carbon atoms which may have a substituent, an aromatic hydrocarbon group having 6 to 15 carbon atoms which may have a substituent, or a substituent. C4-C15 heteroaromatic ring group which may have (the substituent is a C1-C20 alkyl group, a halogen atom such as Br, Cl, I, etc., a C6-C15 aromatic carbonization A hydrogen group, an aralkyl group having 7 to 17 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an alkoxy-carbonyl group having 2 to 20 carbon atoms, and an acyl group having 2 to 15 carbon atoms), and R ^2. Represents an optionally substituted alkylene group having 1 to 10 carbon atoms (the substituent includes an alkyl group having 1 to 20 carbon atoms and an aromatic hydrocarbon group having 6 to 15 carbon atoms). , N represents an integer of 1 to 100.
In addition, the (R ² —O) n portion of the formula (1) may be two or three groups within the above range. Specific examples include random or block combinations of ethyleneoxy group and propyleneoxy group, ethyleneoxy group and isopropyloxy group, ethyleneoxy group and butyleneoxy group, ethyleneoxy group and isobutylene group, and the like.

  These surfactants can be used alone or in combination. Further, the content of these surfactants in the developer is preferably from 0.1 to 20% by weight in terms of active ingredients.

  In the present invention, in addition to the above components, the following components can be used in combination in the developer as required. For example, benzoic acid, phthalic acid, p-ethylbenzoic acid, pn-propylbenzoic acid, p-isopropylbenzoic acid, pn-butylbenzoic acid, pt-butylbenzoic acid, p-2-hydroxyethylbenzoic acid Organic carboxylic acids such as acid, decanoic acid, salicylic acid, 3-hydroxy-2-naphthoic acid; organic solvents such as isopropyl alcohol, benzyl alcohol, ethyl cellosolve, butyl cellosolve, phenyl cellosolve, propylene glycol, diacetone alcohol; Agents, reducing agents, dyes, pigments, water softeners, preservatives, antifoaming agents and the like. The pH of the developer in the present invention is generally from 10 to 13, preferably from 11 to 12.8, more preferably from 11.2 to 12.5.

The development of the photopolymerizable lithographic printing plate of the present invention with the developer is usually 0 to 60 ° C., preferably about 15 to 40 ° C., more preferably 20 to 30 ° C. according to a conventional method, for example, exposure treatment. The photopolymerizable lithographic printing plate is immersed in a developer and rubbed with a brush.
Furthermore, in the developing process using an automatic developing machine, the developing solution becomes fatigued according to the processing amount. Therefore, the replenishing solution or a fresh developing solution may be used to restore the processing capability.
In the present invention, a protective layer is provided on the photopolymerizable photosensitive layer. However, the above-described developer may be used to remove the protective layer and remove the unexposed portion of the photosensitive layer at the same time. Alternatively, the protective layer may be removed first with water or warm water, and then the unexposed photosensitive layer may be removed with a developer. These water or warm water can contain, for example, a preservative described in JP-A-10-10754, an organic solvent described in JP-A-8-278636, and the like.

The photopolymerizable lithographic printing plate thus developed is washed with water as described in JP-A Nos. 54-8002, 55-11545, 59-58431, and the like. It is post-treated with a desensitizing solution containing a rinsing solution containing a surfactant or the like, gum arabic or a starch derivative. These treatments can be used in various combinations for the post-treatment of the photopolymerizable lithographic printing plate of the present invention.
The printing plate obtained by the above treatment can be improved in printing durability by post-exposure treatment or heating treatment such as burning according to the method described in JP-A-2000-89478.
Next, the lithographic printing plate obtained by the above processing is loaded on an offset printing machine and used for printing a large number of sheets.

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

[Preparation of polymerizable photosensitive lithographic printing plate]
An aluminum plate of material 1S having a thickness of 0.30 mm was used with a No. 8 nylon brush and an 800 mesh Bamiston water suspension, and the surface was grained and washed thoroughly with water. After being etched by being immersed in 10% by mass sodium hydroxide at 70 ° C. for 60 seconds, washed with running water, neutralized with 20% by mass HNO ₃ and washed with water. This was subjected to an electrolytic surface-roughening treatment in a 1% by mass nitric acid aqueous solution using a sinusoidal alternating waveform current under the condition of VA = 12.7 V at an anode time electricity of 300 coulomb / dm ² . When the surface roughness was measured, it was 0.45 μm (Ra indication). Subsequently, it was immersed in a 30% by mass H ₂ SO ₄ aqueous solution, desmutted at 55 ° C. for 2 minutes, and then placed on a grained surface in a 33 ° C., 20% by mass H ₂ SO ₄ aqueous solution. When anodized for 50 seconds at a current density of 5 A / dm ² , the thickness was 2.7 g / m ² .

  On the aluminum plate thus treated, an undercoat layer was provided by the following procedure.

(Liquid composition for undercoat 1)
The following compound Mw = about 50,000 Acid value 1.00 meq / g 0.19 mass part

メタノール ５５０質量部
水 ３５質量部

Methanol 550 parts by weight Water 35 parts by weight

This coating solution was applied onto the treated aluminum plate with a No. 4 bar coater so as to be ² mg / m ^2, and dried at 100 ° C. for 10 seconds.
On the undercoat layer thus obtained, a polymerizable photosensitive composition 1 having the following composition was applied so that the dry coating mass was 1.4 g / m ^2, and dried at 95 ° C. for 50 seconds to obtain a photosensitive layer. Formed.

(Polymerizable photosensitive composition 1)
NK ester A-TMMT (tetramethylol methane tetraacrylate,
Shin-Nakamura Chemical Co., Ltd.) 1.7 parts by mass / binder (molecular weight 130,000)
1.9 parts by mass

Sensitizer (C1 below) 0.15 parts by weight Polymerization initiator (D1 below) 0.13 parts by weight Sensitizer (E1 below) 0.53 parts by weight Colorant Below 3 types of dispersion 1 0.7 part by mass ε-phthalocyanine 15% by mass (F1 below) / 10% by mass of the following binder (molecular weight 100,000) / 75% by mass of propylene glycol monomethyl ether acetate

・ Fluoro-based nonionic surfactant Megafac F176 0.06 parts by mass (Dainippon Ink Chemical Co., Ltd.)
・ Polymerization inhibitor Cuperon AL (Wako Pure Chemical Industries) 10 mass% plasticizer, dispersion of tricresyl phosphate (TCP) 90 mass% 0.06 mass parts

・ Solvent Methyl ethyl ketone 20.0 mass parts ・ Solvent Propylene glycol monomethyl ether acetate 20.0 mass parts

(Polymerizable photosensitive composition 2)
It was prepared in the same manner as the polymerizable photosensitive composition 1 except that the following Dye1 was used instead of the sensitizing dye C1.

(Oxygen barrier protective layer composition)
Polyvinyl alcohol (PVA-105, manufactured by Kuraray Co., Ltd. (saponification degree 98 mol%, polymerization degree 500) 6.0 parts by mass EMALEX 710 (manufactured by Nippon Emulsion Co., Ltd., surfactant) 0.1 parts by mass Polyvinylpyrrolidone K30 0.2 parts by mass · Rubitech VA64 (6: 4 ratio copolymer of vinyl pyrrolidone and vinyl acetate manufactured by BASF) 0.2 parts by mass · water 100.0 parts by mass It apply | coated so that it might become 5 g / m < ² >, and it was dried at 100 degreeC for 90 second.

[Prepress conditions]
Version size: 80x103cm
[Evaluation image]
2540 dpi, 175 lines / inch, 3% halftone dot image

[Exposure condition 1]
Using a Luxe Plate Setter P-9600CTP manufactured by Fuji Photo Film Co., Ltd. equipped with an FD-YAG laser (532 nm), exposure was performed at 0.2 mJ / cm ² . The time required for exposure only is 80 seconds.
[Exposure condition 2]
Exposure is performed at 90 μJ / cm ² using Luxel V9600CTP manufactured by Fuji Photo Film Co., Ltd. equipped with a semiconductor laser of 405 nm. The time required only for exposure is 70 seconds.

[Buffer part]
As shown in Fig. 2, a device that transports a plate from a setter to an automatic machine by a belt conveyor driven by a motor in a light-shielded box of length 100 x width 180 x height 30 cm. A sequence of sending a signal to the setter body by attaching a combination of sensor head LV-H42 (650 nm, output 3 mW) and amplifier unit LV-21A having a light projecting unit and a light receiving unit in one head. Assembled. The transport motor detects a sensitive material with a sensor by a timer, and has a circuit that stops for a certain time and then drives again.
When the lithographic printing plate was continuously moved from the exposure section to the development section without stopping for a certain period of time in the buffer section, it took 25 seconds from the end of exposure to entering the heating section.

[Development condition 1]
Using an automatic processor LP1250PII manufactured by Fuji Photo Film Co., Ltd., post-heating is performed so that the plate surface temperature becomes 100 ° C. at the center of the back surface of the plate in the preheating portion, and oxygen is added at about 23 ° C. water in the pre-washing tank. The blocking protective layer was removed by washing with water. Thereafter, development was performed at 28 ° C. for 19 seconds using a developer DV-2: water = 1: 4 (pH 11.95 at 28 ° C.) manufactured by Fuji Photo Film Co., Ltd. in a developing tank. After that, it was washed with water in a water tank, finished in a gum tank with Fuji Photo Film Co., Ltd. finishing gum FP-2W: water = 1: 1, and heated at 50 ° C. in the heating section. Dried.

[Evaluation of polymerizable lithographic printing plate]
[Small point reproducibility]
The printing plate was divided into approximately 20 × 20 cm with Ccdot manufactured by Centurfax, and 20 dot areas were measured.

  It can be seen that the dispersion is remarkably small and stable when the buffer portion is stopped for 10 seconds or longer and the time from the completion of latent image formation by the plate making method of the present invention to the time of the heat treatment being 30 seconds or longer.

It is the schematic of the plate-making apparatus used by this invention. It is the schematic of the buffer part in the plate-making apparatus used by this invention. It is explanatory drawing which shows one form of the automatic processor which has a heating part used by this invention.

Claims (2)

Develop the exposure part that forms a latent image by irradiating the photopolymerizable lithographic printing plate, the heating part that heats the photopolymerizable lithographic printing plate after the latent image formation is completed, and develops the photopolymerizable lithographic printing plate after the heat treatment A plate making apparatus having a developing unit for processing is provided with a buffer unit for controlling heat treatment in a heating unit after 30 seconds or more after the completion of latent image formation on a photopolymerizable lithographic printing plate by light irradiation. A plate making device. The buffer unit includes a feed mechanism that transports the photopolymerizable lithographic printing plate after the completion of latent image formation from the exposure unit to the heating unit, and light irradiation is performed by stopping transport and / or increasing or decreasing the transport speed in the feed mechanism. 2. The plate making apparatus according to claim 1, wherein a heat treatment in the heating unit is controlled after 30 seconds or more after the completion of latent image formation on the photopolymerizable lithographic printing plate.

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