JP2005084303A - Plate making method for photopolymerizable photosensitive planographic printing plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plate making method for a photopolymerizable photosensitive planographic printing plate by which even when the photopolymerizable photosensitive planographic printing plate including a photosensitive layer having spectral sensitivity in a wavelength band of at least 360-450 nm is imagewise exposed with relatively low output semiconductor laser light oscillating in a wavelength band of 360-450 nm and developed, a tough image can be formed and high printing durability and excellent fine dot reproducibility can be achieved. <P>SOLUTION: Light exposure for the imagewise exposure is made 4.0 to <10.0 times the minimum light exposure E<SB>G</SB>necessary for image formation obtained from a characteristic curve of the photopolymerizable photosensitive planographic printing plate. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a plate making method of a photopolymerization type photosensitive lithographic printing plate. More specifically, in the present invention, a photopolymerization type photosensitive lithographic printing plate having spectral sensitivity in a wavelength region of at least 360 nm to 450 nm is image-exposed with a relatively low output semiconductor laser light oscillating in a wavelength region of 360 nm to 450 nm. The present invention relates to a plate making method for producing a lithographic printing plate that can form a strong image even when it is developed, and realizes high printing durability and excellent small dot reproducibility.

  Conventionally, as a lithographic printing plate, a PS plate having a configuration in which an oleophilic photosensitive resin layer is provided on a hydrophilic support is widely used. As the plate making method, mask exposure (typically through a lithographic film) After the surface exposure), the desired printing plate was obtained by dissolving and removing the non-image area.

  In recent years, digitization techniques for electronically processing, storing, and outputting image information using a computer have become widespread, and various new image output methods corresponding to the technique have come into practical use. As a result, a computer-to-plate (CTP) technique for scanning a highly directional light such as a laser beam in accordance with digitized image information and directly producing a printing plate without using a lith film is desired. Obtaining a printing plate precursor adapted to this is an important technical issue. As one of the methods for obtaining such a lithographic printing plate capable of scanning exposure, an ink-receptive photosensitive resin layer (hereinafter referred to as a photosensitive layer) provided on a hydrophilic support has been excellent in photosensitive speed. A photopolymerization type photosensitive lithographic printing plate using a photopolymerization composition has been proposed and is already on the market.

In addition, regarding a CTP system using a long wavelength visible light source such as an Ar laser (488 nm) or an FD-YAG laser (532 nm) as an exposure light source, it is hoped that writing is performed at a higher speed in order to increase the productivity of the plate making process. It is rare.
On the other hand, in recent years, for example, semiconductor lasers using an InGaN-based material and capable of continuous oscillation in a 360 nm to 450 nm region are in the practical stage. The scanning exposure system using these short-wave light sources has an advantage that an economical system can be constructed because a semiconductor laser can be manufactured at a low cost because of its structure. Furthermore, the diameter of the spinner mirror used for scanning the laser beam can be smaller than that of a system using a conventional FD-YAG laser or Ar laser, and the air resistance during high-speed rotation of the mirror is small. The upper limit is increased, writing at a higher speed is possible, and productivity is improved. In addition, it is possible to use a light-sensitive material with a short photosensitive area capable of working under a brighter safelight.

  However, the output of the short-wave semiconductor laser is still a fraction of a fraction to a fraction of that of the output of a conventional Ar laser or FD-YAG laser. Even if it was formed, the image strength was weak, and the required printing durability could not be obtained unless the plate material after the development treatment was subjected to heat treatment or post-exposure. Accordingly, it is desired to improve the laser output and the sensitivity of the photosensitive lithographic printing plate.

For example, Patent Document 1 discloses a plate making method for producing a lithographic printing plate by image-exposing and developing a polymerization type photosensitive lithographic printing plate with a semiconductor laser beam oscillating in a wavelength range of 360 to 450 nm. Has been.
Patent Document 1 discloses an inner drum type in which a lithographic printing plate comprising at least (A) an aluminum support and (B) a laser-sensitive recording layer is sequentially used from a semiconductor laser beam in the ultraviolet to visible light region (360 to 450 nm). A plate making method of a lithographic printing plate is disclosed, which is characterized by exposing with a plate setter.
Moreover, the photosensitive composition used suitably for the plate-making method using the said semiconductor laser beam is disclosed by the following patent document 2, for example.
Patent Document 2 reacts with at least one of (i) a sensitizing dye having a specific structure, (ii) a titanocene compound, (iii) a radical and an acid, and changes at least one of its physical and chemical properties. A photosensitive composition containing a compound to be retained is disclosed.
JP 2000-35673 A Japanese Patent Laid-Open No. 2001-100412

  Accordingly, an object of the present invention is to solve the above-mentioned problems of the prior art and to provide a photopolymerization type photosensitive lithographic printing plate containing a photosensitive layer having spectral sensitivity in a wavelength range of at least 360 nm to 450 nm. Even if the image is exposed and developed with a relatively low-power semiconductor laser beam that oscillates in, a strong image can be formed, and high printing durability and excellent dot reproducibility are realized. The present invention also provides a method for making a polymerization type photosensitive lithographic printing plate.

As a result of intensive studies, the present inventors have succeeded in achieving the object with the following configuration.
That is, the present invention is as follows.
(1) A photopolymerization type photosensitive lithographic printing plate containing a photosensitive layer having a spectral sensitivity in a wavelength range of at least 360 nm to 450 nm is image-exposed with a semiconductor laser beam oscillated in a wavelength range of 360 nm to 450 nm, and developed. In the plate making method of a photopolymerization type photosensitive lithographic printing plate for producing a lithographic printing plate, the image exposure amount in the image exposure is necessary for image formation obtained from the characteristic curve of the photopolymerization type photosensitive lithographic printing plate. photopolymerizable photosensitive lithographic printing plate the process for making, wherein a minimum exposure amount is 4.0 times or more to 10.0 times less than the E _G.

(2) The photopolymerization according to (1) above, wherein the photosensitive layer of the photopolymerization type photosensitive lithographic printing plate comprises the following (i), (ii) and (iii): Plate making method of photosensitive type lithographic printing plate.
(I) a sensitizing dye having an absorption maximum in a wavelength range of 360 nm to 450 nm,
(Ii) a photopolymerization initiator, and (iii) an addition polymerizable compound having an ethylenically unsaturated double bond.
(3) The photopolymerization type lithographic printing plate making method as described in (2) above, wherein the photopolymerization initiator is a titanocene compound.

  According to the present invention, a relatively low-power semiconductor laser beam that oscillates a photopolymerizable photosensitive lithographic printing plate containing a photosensitive layer having spectral sensitivity in a wavelength range of at least 360 nm to 450 nm in a wavelength range of 360 nm to 450 nm. A plate-making method for a polymerization type photosensitive lithographic printing plate that can form a strong image even when it is exposed to light and developed, and realizes high printing durability and excellent small dot reproducibility. Is provided.

Hereinafter, embodiments of the present invention will be described in detail.
[Characteristic curve]
In the present invention, as described above, the image exposure amount is determined from the characteristic curve of the photopolymerization type photosensitive lithographic printing plate, minimal exposure E 4.0 times 10.0 times less _G needed for imaging It is characterized by being.
First, the method of obtaining the characteristic curve of the photopolymerization type photosensitive lithographic printing plate and E _G, with reference to the drawings. This characteristic curve and the minimum exposure amount E _G are those determined in the prepress environment.
Figure 1 is a diagram for explaining how to determine the characteristic curve and E _G of the photopolymerization type photosensitive lithographic printing plate.
As for the characteristic curve of the photopolymerization type photosensitive lithographic printing plate, since there is no generally accepted formal standard such as a silver salt film, a known method in the present invention, for example, “Photosensitivity” by Mototaro Nagamatsu and Hideo Inui. "Polymer" Kodansha Scientific, p49-54, or Ao Yamaoka "Basics and Applications of Photopolymer", CMC Publishing Co., Ltd. Prepared according to the method described in p105-113. That is, a desired photopolymerization type photosensitive lithographic printing original plate is subjected to image exposure by sequentially changing the exposure amount in a stepwise manner with a constant exposure amount width, and thereafter developed to form an image, as shown in FIG. In addition, the horizontal axis represents the logarithm of the amount of irradiation light E for image exposure by laser light, Log E, and the vertical axis represents the remaining film amount per unit area of the photopolymerization type photosensitive composition after development processing. Take the percentage (standardized film thickness) divided by the weight of the photosensitive layer. Minimum exposure amount E _G necessary for the image formation is determined as the intersection of the horizontal axis of the characteristic curve (X axis). In the case of FIG. 1, the minimum exposure amount E _G is 11.23 (μJ / cm ² ).

Also, if the photopolymerizable photosensitive lithographic printing plate of the photosensitive layer is colored for image visualization have been made, as a method for determining the simpler E _G, similarly to FIG. 1, the photopolymerization type photosensitive lithographic printing After exposing the image to a plate with a constant width and varying the amount of exposure, developing the image to form an image, measure the reflection density of the image after development, and then standardize the image according to the following formula: and calculate the concentration, the minimum exposure amount E _G, can be determined as the intersection of the horizontal axis of the characteristic curve (X axis).
The reflection density can be easily measured using a commercially available analytical instrument, for example, using a reflection densitometer manufactured by GRETAG-MaCbeth.

Normalized image density = (image density D1 of exposure amount E1−reflection density D0 of support) / (saturated image density−D0)
Here, the saturated image density means a saturated image density when an exposure amount sufficient for image formation is given.

Figure 2 is a diagram for explaining the case of using the normalized image density, a method of obtaining the characteristic curves and E _G of the photopolymerization type photosensitive lithographic printing plate.
As shown in FIG. 2, the logarithm Log E of the irradiation exposure amount is plotted on the horizontal axis, and the normalized image density is plotted on the vertical axis. Minimum exposure amount E _G necessary for the image formation is determined by the intersection of the horizontal axis of the characteristic curve (X axis). For Figure 2, minimum exposure amount E _G is 11.23 (μJ / cm ^2).

[Calculation of appropriate exposure range]
As described above, as long required E _G from the characteristic curve, suitability exposure amount can be selected less than 10 times 4 times more E _G. When the exposure amount of less than 4 times the E _G Highlights is insufficient reproducibility of the reticulum point, the small dot than 2% 175 lines, on the plate after development, disappear There is a case. Further, the printing durability is also lowered. The exposure amount is more than 10 times the E _G, it takes time to image exposure, thereby dropping productivity. Further, due to flare light at the time of laser exposure, there is a case where 95% or more of the shadow portion halftone dot is clogged or the flat halftone portion is uneven. Preferred exposure range five times to 9.5 times the E _G, more preferably 5.5 times to 9.5 times the E _G.

[Photopolymerization type photosensitive lithographic printing plate]
The constitution of the photopolymerization type photosensitive lithographic printing plate (lithographic printing plate precursor) having spectral sensitivity in the wavelength range of 360 nm to 450 nm used in the present invention will be described in order.

[Support]
First, the support for the photopolymerization type photosensitive lithographic printing plate 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. ) And laminated metal, 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 and 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 alloys having 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 Japanese Patent Publication No. 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. Furthermore, electrochemical graining method that electrochemically grains in hydrochloric acid or nitric acid electrolyte solution, 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 of 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 amount of aluminum dissolved 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 an 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, benzene sulfonic 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. A range of 5 to 60 amperes / dm ² , a voltage of 1 to 100 V, and an 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. 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 fluorinated zirconate or phosphate.

  In the present invention, a photopolymerizable photosensitive layer made of, for example, a 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, by applying a protective layer, a photopolymerization type photosensitive lithographic printing plate is formed, but an organic or inorganic undercoat layer may be provided as necessary before coating the photopolymerizable photosensitive layer. Alternatively, 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 performed.

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 phenylphosphonic 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 Hydroxy such as amine hydrochloride -Alanine, and hydrochlorides of amines having a group 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 a method of providing the substrate by drying, 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 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 photopolymerization type photosensitive 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 this inorganic undercoat layer is the same as the organic undercoat layer described above. .

(Photosensitive layer)
The photosensitive layer of the photopolymerization type photosensitive lithographic printing plate used in the present invention has spectral sensitivity in a wavelength region of at least 360 nm to 450 nm. Preferably, it is a photopolymerization type photosensitive lithographic printing plate comprising the following (i) to (iii).
(I) a sensitizing dye having an absorption maximum in a wavelength range of 360 nm to 450 nm,
(Ii) A photopolymerization initiator, preferably a titanocene compound, and (iii) an addition polymerizable compound having an ethylenically unsaturated double bond.

[Sensitizing dye]
The sensitizing dye used in the photopolymerization type photosensitive lithographic printing plate used in the present invention is a sensitizing dye having an absorption maximum in a wavelength range of 360 nm to 450 nm. Examples of such a sensitizing dye include merocyanine dyes represented by the following general formula (2), benzopyrans and coumarins represented by the following general formula (3), and fragrances represented by the following general formula (4). Group ketones, anthracenes represented by the following general formula (5), and the like.

(In the formula, A represents an S atom or NR ₆ , R ₆ represents a monovalent non-metallic atomic group, Y represents a basic nucleus of the dye in cooperation with the adjacent A and the adjacent carbon atom. A non-metallic atomic group, X ₁ and X ₂ each independently represent a monovalent non-metallic atomic group, and X ₁ and X ₂ may combine with each other to form an acidic nucleus of the dye.)

(In the formula, = Z represents a carbonyl group, a thiocarbonyl group, an imino group or an alkylidene group represented by the partial structural formula (1 ′), and X ₁ and X ₂ have the same meanings as in the general formula (2). R _{7 to} R ₁₂ each independently represents a monovalent nonmetallic atomic group.)

(In the formula, Ar ₃ represents an aromatic group or a heteroaromatic group which may have a substituent, and R ₁₃ represents a monovalent nonmetallic atomic group. More preferred R ₁₃ represents an aromatic group or It is a heteroaromatic group, and Ar ₃ and R ₁₃ may be bonded to each other to form a ring.)

(In the formula, X ₃ , X ₄ and R _{14 to} R ₂₁ each independently represent a monovalent non-metallic atomic group, and more preferable X ₃ and X ₄ are electron donating groups having a negative Hammett's substituent constant. .)

In the general formulas (2) to (5), preferred examples of the monovalent nonmetallic atomic group represented by X ₁ to X ₄ and R ₆ to R ₂₁ are as follows:
Hydrogen atom, alkyl group (for example, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, hexadecyl group, Octadecyl group, eicosyl group, isopropyl group, isobutyl group, s-butyl group, t-butyl group, isopentyl group, neopentyl group, 1-methylbutyl group, isohexyl group, 2-ethylhexyl group, 2-methylhexyl group, cyclohexyl group, Cyclopentyl, 2-norbornyl, chloromethyl, bromomethyl, 2-chloroethyl, trifluoromethyl, methoxymethyl, methoxyethoxyethyl, allyloxymethyl, phenoxymethyl, methylthiomethyl, tolylthiomethyl Group, ethylamino Group, diethylaminopropyl group, morpholinopropyl group, acetyloxymethyl group, benzoyloxymethyl group, N-cyclohexylcarbamoyloxyethyl group, N-phenylcarbamoyloxyethyl group, acetylaminoethyl group, N-methylbenzoylaminopropyl group, 2-oxoethyl group, 2-oxopropyl group, carboxypropyl group, methoxycarbonylethyl group, allyloxycarbonylbutyl group, chlorophenoxycarbonylmethyl group, carbamoylmethyl group, N-methylcarbamoylethyl group, N, N-dipropylcarbamoyl Methyl group, N- (methoxyphenyl) carbamoylethyl group, N-methyl-N- (sulfophenyl) carbamoylmethyl group, sulfobutyl group, sulfonatobutyl group, sulfamoylbutyl N-ethylsulfamoylmethyl group, N, N-dipropylsulfamoylpropyl group, N-tolylsulfamoylpropyl group, N-methyl-N- (phosphonophenyl) sulfamoyloctyl group, phosphonobutyl Group, phosphonatohexyl group, diethylphosphonobutyl group, diphenylphosphonopropyl group, methylphosphonobutyl group, methylphosphonatobutyl group, tolylphosphonohexyl group, tolylphosphonatohexyl group, phosphonooxypropyl group, phosphineoxypropyl group Onatooxybutyl group, benzyl group, phenethyl group, α-methylbenzyl group, 1-methyl-1-phenylethyl group, p-methylbenzyl group, cinnamyl group, allyl group, 1-propenylmethyl group, 2-butenyl group, 2-methylallyl group, 2-methylpropenylmethyl , 2-propynyl group, 2-butynyl group, 3-butynyl group, etc.), aryl group (for example, phenyl group, biphenyl group, naphthyl group, tolyl group, xylyl group, mesityl group, cumenyl group, chlorophenyl group, bromophenyl group) , Chloromethylphenyl group, hydroxyphenyl group, methoxyphenyl group, ethoxyphenyl group, phenoxyphenyl group, acetoxyphenyl group, benzoyloxyphenyl group, methylthiophenyl group, phenylthiophenyl group, methylaminophenyl group, dimethylaminophenyl group Acetylaminophenyl group, carboxyphenyl group, methoxycarbonylphenyl group, ethoxyphenylcarbonyl group, phenoxycarbonylphenyl group, N-phenylcarbamoylphenyl group, phenyl group, cyanophenyl group, sulfophe Group, sulfonatophenyl group, phosphonophenyl group, phosphonatophenyl group, etc.), heteroaryl group (for example, thiophene, thiathrene, furan, pyran, isobenzofuran, chromene, xanthene, phenoxazine, pyrrole, pyrazole, isothiazole) , Isoxazole, pyrazine, pyrimidine, pyridazine, indolizine, isoindolizine, indoir, indazole, purine, quinolidine, isoquinoline, phthalazine, naphthyridine, quinazoline, cinnoline, pteridine, carbazole, carboline, phenanthrine, acridine, perimidine, phenanth Lorin, phthalazine, phenazazine, phenoxazine, furazane, phenoxazine, etc.), alkenyl groups (for example, vinyl group, 1-propenyl group, 1-butenyl group, Cinnamyl group, 2-chloro-1-ethenyl group, etc.), alkynyl group (for example, ethynyl group, 1-propynyl group, 1-butynyl group, trimethylsilylethynyl group, etc.), halogen atom (-F, -Br, -Cl) , -I), hydroxyl group, alkoxy group, aryloxy group, mercapto group, alkylthio group, arylthio group, alkyldithio group, aryldithio group, amino group, N-alkylamino group, N, N-dialkylamino group, N- Arylamino group, N, N-diarylamino group, N-alkyl-N-arylamino group, acyloxy group, carbamoyloxy group, N-alkylcarbamoyloxy group, N-arylcarbamoyloxy group, N, N-dialkylcarbamoyloxy Group, N, N-diarylcarbamoyloxy group, N-alkyl- -Arylcarbamoyloxy group, alkylsulfoxy group, arylsulfoxy group, acylthio group, acylamino group, N-alkylacylamino group, N-arylacylamino group, ureido group, N'-alkylureido group, N ', N '-Dialkylureido group, N'-arylureido group, N', N'-diarylureido group, N'-alkyl-N'-arylureido group, N-alkylureido group, N-arylureido group, N'- Alkyl-N-alkylureido group, N'-alkyl-N-arylureido group, N ', N'-dialkyl-N-alkylureido group, N', N'-dialkyl-N-arylureido group, N'- Aryl-N-alkylureido group, N′-aryl-N-arylureido group, N ′, N′-diaryl- -Alkylureido group, N ', N'-diaryl-N-arylureido group, N'-alkyl-N'-aryl-N-alkylureido group, N'-alkyl-N'-aryl-N-arylureido group , Alkoxycarbonylamino group, aryloxycarbonylamino group, N-alkyl-N-alkoxycarbonylamino group, N-alkyl-N-aryloxycarbonylamino group, N-aryl-N-alkoxycarbonylamino group, N-aryl- N-aryloxycarbonylamino group, formyl group, acyl group, carboxyl group, alkoxycarbonyl group, aryloxycarbonyl group, carbamoyl group, N-alkylcarbamoyl group, N, N-dialkylcarbamoyl group, N-arylcarbamoyl group, N , N-Diarylcarbamoyl group , N-alkyl-N-arylcarbamoyl group, alkylsulfinyl group, arylsulfinyl group, alkylsulfonyl group, arylsulfonyl group, sulfo group (—SO ₃ H) and its conjugate base group (hereinafter referred to as sulfonate group), alkoxy Sulfonyl group, aryloxysulfonyl group, sulfinamoyl group, N-alkylsulfinamoyl group, N, N-dialkylsulfinamoyl group, N-arylsulfinamoyl group, N, N-diarylsulfinamoyl group, N-alkyl -N-arylsulfinamoyl group, sulfamoyl group, N-alkylsulfamoyl group, N, N-dialkylsulfamoyl group, N-arylsulfamoyl group, N, N-diarylsulfamoyl group, N- Alkyl-N-arylsulfamoyl group, phosphor Group (-PO ₃ H ₂₎ and its conjugated base group (hereinafter referred to as phosphonato group), a dialkyl phosphono group (-PO ₃ (alkyl) _2), diaryl phosphono group (-PO ₃ (aryl) _2), Alkylaryl phosphono group (—PO ₃ (alkyl) (aryl)), monoalkyl phosphono group (—PO ₃ H (alkyl)) and its conjugate base group (hereinafter referred to as alkyl phosphonate group), monoaryl phosphine group Phono group (—PO ₃ H (aryl)) and its conjugate base group (hereinafter referred to as aryl phosphonate group), phosphonooxy group (—OPO ₃ H ₂ ) and its conjugate base group (hereinafter referred to as “phosphonateoxy group”) Dialkylphosphonooxy group (—OPO ₃ (alkyl) ₂ ), diarylphosphonooxy group (—OPO ₃ (aryl) ₂ ), alkylarylphosphonooxy group (—OPO ₃ (alkyl) (aryl)) ) Noalkylphosphonooxy group (—OPO ₃ H (alkyl)) and its conjugate base group (hereinafter referred to as alkylphosphonateoxy group), monoarylphosphonooxy group (—OPO ₃ H (aryl)) and its conjugate Examples include a base group (hereinafter referred to as an arylphosphonatooxy group), a cyano group, a nitro group, etc. Among the above substituents, a hydrogen atom, an alkyl group, an aryl group, a halogen atom, an alkoxy group, and an acyl group Particularly preferred.

  In the general formula (2), the basic nucleus of the dye formed together with A adjacent to Y and the adjacent carbon atom includes a 5, 6 or 7-membered nitrogen-containing or sulfur-containing heterocyclic ring. A 5- or 6-membered heterocyclic ring is preferable.

  Examples of nitrogen-containing heterocycles include, for example, the basic nucleus in merocyanine dyes described in LGBrooker et al., J. Am. Chem. Soc., 73, 5326-5358 (1951). Any of those known to be used can be suitably used. Specific examples include thiazoles (for example, thiazole, 4-methylthiazole, 4-phenylthiazole, 5-methylthiazole, 5-phenylthiazole, 4,5-dimethylthiazole, 4,5-diphenylthiazole, 4,5- Di (p-methoxyphenylthiazole), 4- (2-thienyl) thiazole, etc.), benzothiazoles (for example, benzothiazole, 4-chlorobenzothiazole, 5-chlorobenzothiazole, 6-chlorobenzothiazole, 7- Chlorobenzothiazole, 4-methylbenzothiazole, 5-methylbenzothiazole, 6-methylbenzothiazole, 5-bromobenzothiazole, 4-phenylbenzothiazole, 5-phenylbenzothiazole, 4-methoxybenzothiazole, 5-methoxybenzo Cheer , 6-methoxybenzothiazole, 5-iodobenzothiazole, 6-iodobenzothiazole, 4-ethoxybenzothiazole, 5-ethoxybenzothiazole, tetrahydrobenzothiazole, 5,6-dimethoxybenzothiazole, 5,6-di Oxymethylenebenzothiazole, 5-hydroxybenzothiazole, 6-hydroxybenzothiazole, 6-dimethylaminobenzothiazole, 5-ethoxycarbonylbenzothiazole, etc.), naphthothiazoles (for example, naphtho [1,2] thiazole, naphtho [2 , 1] thiazole, 5-methoxynaphtho [2,1] thiazole, 5-ethoxynaphtho [2,1] thiazole, 8-methoxynaphtho [1,2] thiazole, 7-methoxynaphtho [1,2] thiazole, etc.) , Chianafuteno 7 ′, 6 ′, 4,5-thiazole (for example, 4′-methoxythianaphtheno-7 ′, 6 ′, 4,5-thiazole, etc.), oxazole (for example, 4-methyloxazole, 5-methyloxazole) 4-phenyloxazole, 4,5-diphenyloxazole, 4-ethyloxazole, 4,5-dimethyloxazole, 5-phenyloxazole, etc.), benzoxazoles (benzoxazole, 5-chlorobenzoxazole, 5-methylbenzoxazole) 5-phenylbenzoxazole, 6-methylbenzoxazole, 5,6-dimethylbenzoxazole, 4,6-dimethylbenzoxazole, 6-methoxybenzoxazole, 5-methoxybenzoxazole, 4-ethoxybenzoxazole, 5-chloroben Zoxazole, 6-methoxybenzoxazole, 5-hydroxybenzoxazole, 6-hydroxybenzoxazole, etc.), naphthoxazoles (eg, naphtho [1,2] oxazole, naphtho [2,1] oxazole, etc.), selenazoles ( For example, 4-methylselenazole, 4-phenylselenazole, etc.), benzoselenazoles (for example, benzoselenazole, 5-chlorobenzoselenazole, 5-methoxybenzoselenazole, 5-hydroxybenzoselenazole, tetrahydrobenzo Selenazole etc.), naphthoselenazoles (eg naphtho [1,2] selenazole, naphtho [2,1] selenazole etc.), thiazolines (eg thiazoline, 4-methylthiazoline etc.), 2-quinolines (eg Quinoline, 3- Tilquinoline, 5-methylquinoline, 7-methylquinoline, 8-methylquinoline, 6-chloroquinoline, 8-chloroquinoline, 6-methoxyquinoline, 6-ethoxyquinoline, 6-hydroxyquinoline, 8-hydroxyquinoline, etc.), 4 -Quinolines (eg, quinoline, 6-methoxyquinoline, 7-methylquinoline, 8-methylquinoline, etc.), 1-isoquinolines (eg, isoquinoline, 3,4-dihydroisoquinoline, etc.), 3-isoquinolines (eg, , Isoquinoline, etc.), benzimidazoles (eg, 1,3-diethylbenzimidazole, 1-ethyl-3-phenylbenzimidazole, etc.), 3,3-dialkylindolenins (eg, 3,3-dimethylindolenin, 3,3,5-trimethylindolenine, 3,3 7, - trimethyl indolenine, etc.), 2-pyridines (e.g., pyridine, 5-methyl-pyridine, etc.), 4-pyridine (for example, a pyridine, etc.) or the like.

Examples of the sulfur-containing heterocycle include a dithiol partial structure in dyes described in JP-A-3-296759.
Specific examples include benzodithiols (for example, benzodithiol, 5-t-butylbenzodithiol, 5-methylbenzodithiol, etc.), naphthodithiols (for example, naphtho [1,2] dithiol, naphtho [2,1] Dithiols, etc.), dithiols (for example, 4,5-dimethyldithiols, 4-phenyldithiols, 4-methoxycarbonyldithiols, 4,5-dimethoxycarbonylbenzodithiols, 4,5-ditrifluoromethyldithiols, 4 , 5-dicyanodithiol, 4-methoxycarbonylmethyldithiol, 4-carboxymethyldithiol and the like.

  As mentioned above, for the sake of convenience, the description used in the description of the heterocyclic ring has conventionally used the name of the heterocyclic mother skeleton, but when forming the basic skeleton partial structure of the sensitizing dye, for example, in the case of the benzothiazole skeleton It is introduced as an alkylidene-type substituent with one degree of unsaturation, such as a 3-substituted-2 (3H) -benzothiazolylidene group.

  Of the sensitizing dyes having an absorption maximum in the wavelength range of 360 nm to 450 nm, a dye more preferable from the viewpoint of high sensitivity is a dye represented by the following general formula (1).

(In the general formula (1), A represents an aromatic ring or a hetero ring which may have a substituent, and X represents an oxygen atom, a sulfur atom or N- (R ₃ ). R ₁ , R ₂ and R ₃ each independently represents a hydrogen atom or a monovalent nonmetallic atomic group, and A and R ₁ and R ₂ and R ₃ are bonded to each other to form an aliphatic or aromatic ring. May be.)

The general formula (1) will be described in more detail. R ₁ , R ₂ and R ₃ are each independently a hydrogen atom or a monovalent nonmetallic atomic group, preferably a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, substituted or non-substituted It represents a substituted aryl group, a substituted or unsubstituted aromatic heterocyclic residue, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted alkylthio group, a hydroxyl group, and a halogen atom.

Preferable examples of R ₁ , R ₂ and R ₃ will be specifically described. Examples of preferable alkyl groups include linear, branched, and cyclic alkyl groups having 1 to 20 carbon atoms. Specific examples thereof include a methyl group, an ethyl group, a propyl group, Butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, hexadecyl, octadecyl, eicosyl, isopropyl, isobutyl, s-butyl, Examples thereof include t-butyl group, isopentyl group, neopentyl group, 1-methylbutyl group, isohexyl group, 2-ethylhexyl group, 2-methylhexyl group, cyclohexyl group, cyclopentyl group and 2-norbornyl group. Of these, linear alkyl groups having 1 to 12 carbon atoms, branched alkyl groups having 3 to 12 carbon atoms, and cyclic alkyl groups having 5 to 10 carbon atoms are more preferable.

  As the substituent of the substituted alkyl group, a monovalent nonmetallic atomic group excluding hydrogen is used, and preferred examples include a halogen atom (—F, —Br, —Cl, —I), a hydroxyl group, an alkoxy group, Aryloxy group, mercapto group, alkylthio group, arylthio group, alkyldithio group, aryldithio group, amino group, N-alkylamino group, N, N-dialkylamino group, N-arylamino group, N, N-diarylamino group N-alkyl-N-arylamino group, acyloxy group, carbamoyloxy group, N-alkylcarbamoyloxy group, N-arylcarbamoyloxy group, N, N-dialkylcarbamoyloxy group, N, N-diarylcarbamoyloxy group, N-alkyl-N-arylcarbamoyloxy group, alkylsulfoxy group, Reel sulphoxide group, an acylthio group, an acylamino group, N- alkylacylamino group, N- arylacylamino group, a ureido group, N'- alkylureido group, N ', N'- dialkyl ureido group,

  N'-arylureido group, N ', N'-diarylureido group, N'-alkyl-N'-arylureido group, N-alkylureido group, N-arylureido group, N'-alkyl-N-alkylureido Group, N′-alkyl-N-arylureido group, N ′, N′-dialkyl-N-alkylureido group, N ′, N′-dialkyl-N-arylureido group, N′-aryl-N-alkylureido group Group, N′-aryl-N-arylureido group, N ′, N′-diaryl-N-alkylureido group, N ′, N′-diaryl-N-arylureido group, N′-alkyl-N′-aryl -N-alkylureido group, N'-alkyl-N'-aryl-N-arylureido group, alkoxycarbonylamino group, aryloxycarbonyl Mino group, N-alkyl-N-alkoxycarbonylamino group, N-alkyl-N-aryloxycarbonylamino group, N-aryl-N-alkoxycarbonylamino group, N-aryl-N-aryloxycarbonylamino group, formyl Group, acyl group, carboxyl group,

Alkoxycarbonyl group, aryloxycarbonyl group, carbamoyl group, N-alkylcarbamoyl group, N, N-dialkylcarbamoyl group, N-arylcarbamoyl group, N, N-diarylcarbamoyl group, N-alkyl-N-arylcarbamoyl group, An alkylsulfinyl group, an arylsulfinyl group, an alkylsulfonyl group, an arylsulfonyl group, a sulfo group (—SO ₃ H) and its conjugate base group (hereinafter referred to as a sulfonate group), an alkoxysulfonyl group, an aryloxysulfonyl group, a sulfinamoyl group, N-alkylsulfinamoyl group, N, N-dialkylsulfinamoyl group, N-arylsulfinamoyl group, N, N-diarylsulfinamoyl group, N-alkyl-N-arylsulfinamoyl group, sulfamoyl N-alkylsulfamoyl group, N, N-dialkylsulfamoyl group, N-arylsulfamoyl group, N, N-diarylsulfamoyl group, N-alkyl-N-arylsulfamoyl group, phosphono Group (—PO ₃ H ₂ ) and its conjugate base group (hereinafter referred to as phosphonate group),

Dialkyl phosphono group (—PO ₃ (alkyl) ₂ ), diaryl phosphono group (—PO ₃ (aryl) ₂ ), alkylaryl phosphono group (—PO ₃ (alkyl) (aryl)), monoalkyl phosphono group (—PO ₃ H (alkyl)) and its conjugate base group (hereinafter referred to as alkylphosphonate group), monoarylphosphono group (—PO ₃ H (aryl)) and its conjugate base group (hereinafter referred to as arylphosphonate) Group), phosphonooxy group (—OPO ₃ H ₂ ) and its conjugate base group (hereinafter referred to as phosphonatoxy group), dialkylphosphonooxy group (—OPO ₃ (alkyl) ₂ ), diarylphosphono Oxy group (—OPO ₃ (aryl) ₂ ), alkylaryl phosphonooxy group (—OPO ₃ (alkyl) (aryl)), monoalkyl phosphonooxy group (—OPO ₃ H (alkyl)) and its conjugate base group ( After, referred to as alkyl phosphonophenyl group), monoaryl phosphonooxy group (-OPO ₃ H (aryl)) and its conjugated base group (hereinafter referred to as aryl phosphite Hona preparative group), a cyano group, a nitro group, an aryl Group, heteroaryl group, alkenyl group, alkynyl group.

  Specific examples of the alkyl group in these substituents include the above-described alkyl groups, and specific examples of the aryl group include a phenyl group, a biphenyl group, a naphthyl group, a tolyl group, a xylyl group, a mesityl group, and a cumenyl group. , Chlorophenyl group, bromophenyl group, chloromethylphenyl group, hydroxyphenyl group, methoxyphenyl group, ethoxyphenyl group, phenoxyphenyl group, acetoxyphenyl group, benzoyloxyphenyl group, methylthiophenyl group, phenylthiophenyl group, methylamino Phenyl group, dimethylaminophenyl group, acetylaminophenyl group, carboxyphenyl group, methoxycarbonylphenyl group, ethoxyphenylcarbonyl group, phenoxycarbonylphenyl group, N-phenylcarbamoylphenyl group, phenyl group Cyanophenyl group, sulfophenyl group, sulfonatophenyl group, phosphonophenyl phenyl group, phosphonophenyl phenyl group and the like.

As the preferred heteroaryl group as R ₁ , R ₂ and R ₃ , a monocyclic or polycyclic aromatic ring containing at least one of nitrogen, oxygen and sulfur atoms is used. Examples of particularly preferred heteroaryl groups Is, for example, thiophene, thiathrene, furan, pyran, isobenzofuran, chromene, xanthene, phenoxazine, pyrrole, pyrazole, isothiazole, isoxazole, pyrazine, pyrimidine, pyridazine, indolizine, isoindolizine, indolizine, indazole, indazole, Purine, quinolidine, isoquinoline, phthalazine, naphthyridine, quinazoline, sinoline, pteridine, carbazole, carboline, phenanthrine, acridine, perimidine, phenanthrolin, phthalazine, phenalazine, phenoxazine, flaza And phenoxazine and the like. These may be further benzo-fused and may have a substituent.

Examples of preferable alkenyl groups as R ₁ , R ₂ and R ₃ include vinyl group, 1-propenyl group, 1-butenyl group, cinnamyl group, 2-chloro-1-ethenyl group and the like, and alkynyl Examples of the group include ethynyl group, 1-propynyl group, 1-butynyl group, trimethylsilylethynyl group and the like. Examples of G ₁ in the acyl group (G ₁ CO—) include hydrogen and the above alkyl groups and aryl groups. Among these substituents, even more preferred are halogen atoms (—F, —Br, —Cl, —I), alkoxy groups, aryloxy groups, alkylthio groups, arylthio groups, N-alkylamino groups, N, N— Dialkylamino group, acyloxy group, N-alkylcarbamoyloxy group, N-arylcarbamoyloxy group, acylamino group, formyl group, acyl group, carboxyl group, alkoxycarbonyl group, aryloxycarbonyl group, carbamoyl group, N-alkylcarbamoyl group N, N-dialkylcarbamoyl group, N-arylcarbamoyl group, N-alkyl-N-arylcarbamoyl group, sulfo group, sulfonate group, sulfamoyl group, N-alkylsulfamoyl group, N, N-dialkylsulfamoyl group Group, N-arylsulfa Yl group, N-alkyl-N-arylsulfamoyl group, phosphono group, phosphonate group, dialkyl phosphono group, diaryl phosphono group, monoalkyl phosphono group, alkyl phosphonate group, monoaryl phosphono group, aryl phosphine group Examples include an onato group, a phosphonooxy group, a phosphonateoxy group, an aryl group, and an alkenyl group.

  On the other hand, examples of the alkylene group in the substituted alkyl group include divalent organic residues obtained by removing any one of the hydrogen atoms on the alkyl group having 1 to 20 carbon atoms. Can include linear alkylene groups having 1 to 12 carbon atoms, branched chains having 3 to 12 carbon atoms, and cyclic alkylene groups having 5 to 10 carbon atoms.

Specific examples of preferable substituted alkyl groups as R ₁ , R ₂ and R ₃ obtained by combining the substituent and the alkylene group include chloromethyl group, bromomethyl group, 2-chloroethyl group, trifluoromethyl group, methoxy Methyl group, methoxyethoxyethyl group, allyloxymethyl group, phenoxymethyl group, methylthiomethyl group, tolylthiomethyl group, ethylaminoethyl group, diethylaminopropyl group, morpholinopropyl group, acetyloxymethyl group, benzoyloxymethyl group, N -Cyclohexylcarbamoyloxyethyl group, N-phenylcarbamoyloxyethyl group, acetylaminoethyl group, N-methylbenzoylaminopropyl group, 2-oxoethyl group, 2-oxopropyl group, carboxypropyl group, methoxycarbo Nylethyl group, allyloxycarbonylbutyl group, chlorophenoxycarbonylmethyl group, carbamoylmethyl group, N-methylcarbamoylethyl group, N, N-dipropylcarbamoylmethyl group, N- (methoxyphenyl) carbamoylethyl group, N-methyl- N- (sulfophenyl) carbamoylmethyl group,

  Sulfobutyl group, sulfonatobutyl group, sulfamoylbutyl group, N-ethylsulfamoylmethyl group, N, N-dipropylsulfamoylpropyl group, N-tolylsulfamoylpropyl group, N-methyl-N- (phosphono Phenyl) sulfamoyloctyl group, phosphonobutyl group, phosphonatohexyl group, diethylphosphonobutyl group, diphenylphosphonopropyl group, methylphosphonobutyl group, methylphosphonatobutyl group, tolylphosphonohexyl group, tolylphosphine group Onatohexyl group, phosphonooxypropyl group, phosphonatoxybutyl group, benzyl group, phenethyl group, α-methylbenzyl group, 1-methyl-1-phenylethyl group, p-methylbenzyl group, cinnamyl group, allyl group, 1-propenylmethyl group, 2- Thenyl group, 2-methylallyl group, 2-methyl propenyl methyl group, 2-propynyl group, 2-butynyl, 3-butynyl, and the like.

Specific examples of preferred aryl groups as R ₁ , R ₂ and R ₃ include those in which 1 to 3 benzene rings form a condensed ring, and those in which a benzene ring and a 5-membered unsaturated ring form a condensed ring. Specific examples include a phenyl group, a naphthyl group, an anthryl group, a phenanthryl group, an indenyl group, an acenaphthenyl group, and a fluorenyl group. Among these, a phenyl group and a naphthyl group are more preferable. .

Specific examples of preferred substituted aryl groups as R ₁ , R ₂ and R ₃ include those having a monovalent non-metallic atomic group excluding hydrogen as a substituent on the ring-forming carbon atom of the aryl group described above. . Examples of preferred substituents include the aforementioned alkyl groups, substituted alkyl groups, and those previously shown as substituents in the substituted alkyl group. Preferred examples of such a substituted aryl group include biphenyl group, tolyl group, xylyl group, mesityl group, cumenyl group, chlorophenyl group, bromophenyl group, fluorophenyl group, chloromethylphenyl group, trifluoromethylphenyl group. Hydroxyphenyl group, methoxyphenyl group, methoxyethoxyphenyl group, allyloxyphenyl group, phenoxyphenyl group, methylthiophenyl group, tolylthiophenyl group, ethylaminophenyl group, diethylaminophenyl group, morpholinophenyl group, acetyloxyphenyl group, Benzoyloxyphenyl group, N-cyclohexylcarbamoyloxyphenyl group, N-phenylcarbamoyloxyphenyl group,

  Acetylaminophenyl group, N-methylbenzoylaminophenyl group, carboxyphenyl group, methoxycarbonylphenyl group, allyloxycarbonylphenyl group, chlorophenoxycarbonylphenyl group, carbamoylphenyl group, N-methylcarbamoylphenyl group, N, N-di Propylcarbamoylphenyl group, N- (methoxyphenyl) carbamoylphenyl group, N-methyl-N- (sulfophenyl) carbamoylphenyl group, sulfophenyl group, sulfonatophenyl group, sulfamoylphenyl group, N-ethylsulfamoyl Phenyl group, N, N-dipropylsulfamoylphenyl group, N-tolylsulfamoylphenyl group, N-methyl-N- (phosphonophenyl) sulfamoylphenyl group, phosphonophenyl group, phos Onatophenyl group, diethylphosphonophenyl group, diphenylphosphonophenyl group, methylphosphonophenyl group, methylphosphonatophenyl group, tolylphosphonophenyl group, tolylphosphonatophenyl group, allyl group, 1-propenylmethyl group, 2 -Butenyl group, 2-methylallylphenyl group, 2-methylpropenylphenyl group, 2-propynylphenyl group, 2-butynylphenyl group, 3-butynylphenyl group and the like can be mentioned.

Next, A in the general formula (1) will be described. A represents an aromatic ring or a hetero ring which may have a substituent. Specific examples of the aromatic ring or hetero ring which may have a substituent include R ₁ and R in the general formula (1). similar to those described in ₂ and R ₃ can be exemplified.

  The sensitizing dye represented by the general formula (1) of the present invention includes an acidic nucleus as shown above, an acidic nucleus having an active methylene group, a substituted or unsubstituted aromatic ring or heterocyclic ring. These can be synthesized by referring to Japanese Patent Publication No. 59-28329.

  Preferred specific examples (D1) to (D38) of the compound represented by the general formula (1) are shown below. In addition, an isomer with a double bond connecting an acidic nucleus and a basic nucleus is not limited to either isomer.

  These sensitizing dyes are preferably used in the range of 1.0 to 10.0% by mass of the total components of the photosensitive layer.

(Photopolymerization initiator)
Subsequently, the photoinitiator contained in the photosensitive layer used by this invention is demonstrated. As the photopolymerization initiator contained in the photosensitive layer used in the present invention, various photopolymerization initiators known in patents, literatures, etc., or a combination system of two or more photopolymerization initiators (photopolymerization initiation) System) can be appropriately selected and used. In the present invention, a photopolymerization initiator used alone and a system in which two or more photopolymerization initiators are used in combination are collectively referred to as a photopolymerization initiator.
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.

Also, various photopolymerization initiators have been proposed when using visible light of 400 nm or more as a light source. For example, some photoreductive properties described in US Pat. No. 2,850,445 are described. Dyes, such as rose bengal, eosin, erythrosine, etc., or a combination of a dye and a photopolymerization initiator, such as a complex initiation system of a dye and an amine (Japanese Patent Publication No. 44-20189), hexaarylbiimidazole and a radical A combination system of a generator and a dye (Japanese Patent Publication No. 45-37377), a system of hexaarylbiimidazole and p-dialkylaminobenzylidene ketone (Japanese Patent Publication Nos. 47-2528 and 54-155292), Cyclic cis-α-dicarbonyl compound and dye system (Japanese Patent Laid-Open No. 48-84183), cyclic triazine and merocyanine dye System (Japanese Patent Laid-Open No. 54-151024), a system of 3-ketocoumarin and an activator (Japanese Patent Laid-Open Nos. 52-112681, 58-15503), a system of biimidazole, styrene derivative, thiol ( JP-A-59-140203), organic peroxide and dye system (JP-A-59-1504, JP-A-59-140203, JP-A-59-189340, JP-A-62-174203) JP-B-62-1641, U.S. Pat. No. 4,766,055), dyes and active halogen compounds (JP-A 63-178105, JP-A 63-258903, JP-A 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- No. 138204, etc.), a dye having a rhodanine ring and a radical generator (JP-A-2-17943, JP-A-2-244050).
Furthermore, 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.

  Specifically, di-cyclopentadienyl-Ti-di-chloride, di-cyclopentadienyl-Ti-bis-phenyl, di-cyclopentadienyl-Ti-bis-2,3,4,5, 6-pentafluorophen-1-yl, di-cyclopentadienyl-Ti-bis-2,3,5,6-tetrafluorophen-1-yl, di-cyclopentadienyl-Ti-bis-2, 4,6-trifluorophen-1-yl, di-cyclopentadienyl-Ti-bis-2,6-difluorophen-1-yl, di-cyclopentadienyl-Ti-bis-2,4-difluoro Phen-1-yl, di-methylcyclopentadienyl-Ti-bis-2,3,4,5,6-pentafluorophen-1-yl, di-methylcyclopentadienyl-Ti-bis-2, 3, 5, 6 Tetrafluorophen-1-yl, di-methylcyclopentadienyl-Ti-bis-2,4-difluorophen-1-yl, bis (cyclopentadienyl) -bis (2,6-difluoro-3- ( Pyrid-1-yl) phenyl) titanium and the like.

  In addition, it is preferable that these photoinitiators are used in 0.5-10.0 mass% of the total component of a photosensitive layer.

[Addition polymerizable compound having an ethylenically unsaturated double bond]
The addition-polymerizable compound having an ethylenically unsaturated double bond contained in the photosensitive layer used in the present invention can be selected from compounds having at least one ethylenically unsaturated double bond group, preferably two or more. 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 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.

  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.

  The amount of the addition polymerizable compound having an ethylenically unsaturated double bond is preferably in the range of 5 to 90% by mass, more preferably in the range of 10 to 80% by mass with respect to the total components of the photosensitive layer.

[Polymer binder]
In the present invention, a polymer binder (binder polymer) can be contained in the photosensitive layer.
As the polymer binder, an organic polymer that is soluble or swellable in alkaline water is used because it needs to be dissolved in an alkali developer as well as a film forming agent for the photosensitive layer.
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 monomers 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 photosensitive layer. However, if it exceeds 90% by mass, it may not give favorable results in terms of formed image strength, etc. Is 10 to 90% by mass, more preferably 30 to 80% by mass.
In addition, the use ratio of the addition polymerizable compound having an ethylenically unsaturated double bond and the polymer binder is preferably in the range of 1/9 to 9/1, more preferably 2/8 to 8/2, and most preferably 3/7 to 7/3.

  Further, in the photosensitive layer used in the present invention, in addition to the above basic components, ethylenic unsaturation during the production or storage of the composition for forming the photosensitive layer (photopolymerizable photosensitive composition). In order to prevent unnecessary thermal polymerization of the addition polymerizable compound having a double 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 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 coloring agent may be added for the purpose of coloring the 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. The addition amount of the dye and the pigment is preferably about 0.5% by mass to about 5% by mass of the total components of the photopolymerizable photosensitive composition.
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.
Further, a surfactant can be added to the composition for forming the photosensitive layer in order to improve the coating surface quality. Suitable surfactants include, for example, fluorine-based nonionic surfactants.

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 photosensitive layer in the photopolymerizable lithographic plate used in 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 .

In general, an oxygen-blocking protective layer (overcoat layer) is provided on the photosensitive layer in order to prevent the action of inhibiting the polymerization of oxygen.
The coating weight of the protective layer in the present invention is preferably in the range of 0.7~3.0g / m ^2. If it is less than 0.7 g / m ² , the sensitivity may decrease, and if it exceeds 3.0 g / m ² , the burden on the treatment process may increase.
Examples of the water-soluble vinyl polymer contained in the oxygen-blocking protective layer include polyvinyl alcohol and partial esters, ethers, and acetals thereof, or a substantial amount of unsubstituted vinyl alcohol units that make them necessary water-soluble. And a copolymer thereof. Examples of polyvinyl alcohol include those that are 71-100% hydrolyzed and have a degree of polymerization in the range of 300-2400. 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-217E, PVA-220E, PVA-224E, PVA-405, PVA-420, PVA-613, L-8 etc. are mentioned. Examples of the copolymer include 88-100% hydrolyzed polyvinyl acetate chloroacetate or propionate, polyvinyl formal and polyvinyl acetal, and copolymers thereof. Other useful polymers include polyvinyl pyrrolidone, gelatin and gum arabic, and these may be used alone or in combination.

As the solvent used for coating the oxygen-blocking protective layer in the photosensitive lithographic printing plate of the present invention, pure water is preferable, but alcohols such as methanol and ethanol, and ketones such as acetone and methyl ethyl ketone are mixed with pure water. May be. The concentration of the solid content in the coating solution is suitably 1 to 20% by mass. In the oxygen-blocking protective layer of the present invention, known additives such as a surfactant for improving coating properties and a water-soluble plasticizer for improving physical properties of the film may be added. Examples of the water-soluble plasticizer include propionamide, cyclohexanediol, glycerin, sorbitol and the like. A water-soluble (meth) acrylic polymer may be added. The coating amount is suitably in the range of about 0.1 g / m ² to about 15 g / m ² in terms of the mass after drying. More preferably, it is 1.0 g / m ² to about 5.0 g / m ² .

[Plate making process]
Next, the plate making method of the photosensitive lithographic printing plate of the present invention will be described in detail. In the exposure method of the photosensitive lithographic printing plate described above, an AlGaInN semiconductor laser (commercially available InGaN-based semiconductor laser 5 to 30 mW) is suitable as a light source in terms of wavelength characteristics and cost.

  The exposure mechanism may be any of an internal drum system, an external drum system, a flat bed system, and the like. Moreover, the photosensitive layer component of the photosensitive lithographic printing plate of the present invention can be made soluble in neutral water or weak alkaline water by using a highly water-soluble component. The planographic printing plate can be loaded on a printing press and then subjected to a method such as exposure-development on the press. After the image exposure, the entire surface may be heated between exposure and development as necessary. By such heating, an image forming reaction in the photosensitive layer is promoted, and advantages such as improvement in sensitivity and printing durability and stabilization of sensitivity may occur. Further, for the purpose of improving the image strength and printing durability, it is also effective to carry out whole surface post-heating or whole surface exposure on the developed image. Usually, heating before development is preferably performed under mild conditions of 150 ° C. or less. If the temperature is too high, problems such as covering the non-image area occur. Very strong conditions are used for heating after development. Usually, it is the range of 200-500 degreeC. If the temperature is low, sufficient image strengthening action cannot be obtained. If the temperature is too high, problems such as deterioration of the support and thermal decomposition of the image area occur.

(Developer)
The developer used in the plate making method of the lithographic printing plate is not particularly limited. For example, a developer containing an inorganic alkali salt and a nonionic surfactant and having a pH of 11.0 to 12.5 is preferably used. The
The inorganic alkali salt can be used as appropriate. For example, sodium hydroxide, potassium, ammonium, lithium, sodium silicate, potassium, ammonium, lithium, tribasic sodium phosphate, potassium, ammonium Inorganic alkaline agents such as sodium carbonate, potassium, ammonium, sodium hydrogen carbonate, potassium, ammonium, sodium borate, potassium, and ammonium. These may be used alone or in combination of two or more.

When silicate is used, developability is achieved by adjusting the mixing ratio and concentration of silicon oxide SiO ₂ and alkali oxide M ₂ O (M represents an alkali metal or ammonium group), which is a component of silicate. Can be easily adjusted. Among the alkaline aqueous solutions, those having a mixing ratio (SiO ₂ / M ₂ O: molar ratio) of silicon oxide SiO ₂ and alkali oxide M ₂ O of 0.5 to 3.0 are preferred, and those of 1.0 to 2.0 are preferred. When the SiO ₂ / M ₂ O is less than 0.5, it is preferably 1 to 10% by mass, more preferably 3 to 8% by mass, and most preferably 4 to 7% by mass with respect to the mass of the alkaline aqueous solution. If this concentration is 1% by mass or more, developability and processing capacity do not decrease, and if it is 10% by mass or less, it becomes difficult to form precipitates and crystals, and further, it becomes difficult to gel during neutralization in waste liquid, Does not interfere with waste liquid treatment.

  In addition, an organic alkali agent may be supplementarily used for the purpose of finely adjusting the alkali concentration and assisting the solubility of the photosensitive layer. Examples of the organic alkali agent include monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine, triethylamine, monoisopropylamine, diisopropylamine, triisopropylamine, n-butylamine, monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, Examples thereof include diisopropanolamine, ethyleneimine, ethylenediamine, pyridine, tetramethylammonium hydroxide and the like. These alkali agents are used alone or in combination of two or more.

  The surfactant can be used as appropriate, for example, nonionic surfactants having a polyoxyalkylene ether group, polyoxyethylene alkyl esters such as polyoxyethylene stearate, sorbitan monolaurate, sorbitan monostearate, Nonionic surfactants such as sorbitan alkyl esters such as sorbitan distearate, sorbitan monooleate, sorbitan sesquioleate and sorbitan trioleate, monoglyceride alkyl esters such as glycerol monostearate and glycerol monooleate; dodecylbenzenesulfonic acid Alkylbenzene sulfonates such as sodium, sodium butyl naphthalene sulfonate, sodium pentyl naphthalene sulfonate, sodium hexyl naphthalene sulfonate Anion interfaces such as alkyl naphthalene sulfonates such as sodium and sodium octyl naphthalene sulfonate, alkyl sulfates such as sodium lauryl sulfate, alkyl sulfonates such as sodium dodecyl sulfonate, and sulfosuccinate esters such as sodium dilauryl sulfosuccinate Activators: Alkyl betaines such as lauryl betaine and stearyl betaine, amphoteric surfactants such as amino acids, and the like can be mentioned. Particularly preferred are nonionic surfactants having a polyoxyalkylene ether group.

As the surfactant containing a polyoxyalkylene ether group, those having the structure of the following general formula (I) are preferably used.
R ⁴⁰ −O− (R ⁴¹ -O) _p H (I)

In the formula, R ⁴⁰ has an optionally substituted alkyl group having 3 to 15 carbon atoms, an optionally substituted aromatic hydrocarbon group having 6 to 15 carbon atoms, or a substituent. A C4-C15 heteroaromatic cyclic group (wherein the substituent is a C1-C20 alkyl group, a halogen atom such as Br, Cl, I, etc., a C6-C15 aromatic hydrocarbon) group, an aralkyl group having from 7 to 17 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an alkoxycarbonyl group having 2 to 20 carbon atoms, and an acyl group having from 2 to 15 carbon atoms.) indicates, R ⁴¹ is An alkylene group having 1 to 100 carbon atoms which may have a substituent (in addition, examples of the substituent include an alkyl group having 1 to 20 carbon atoms and an aromatic hydrocarbon group having 6 to 15 carbon atoms). P represents an integer of 1 to 100.

  In the definition of the above formula (I), specific examples of the “aromatic hydrocarbon group” include a phenyl group, a tolyl group, a naphthyl group, an anthryl group, a biphenyl group, a phenanthryl group, and the like, and a “heteroaromatic ring”. Specific examples of the “group” include furyl group, thionyl group, oxazolyl group, imidazolyl group, pyranyl group, pyridinyl group, acridinyl group, benzofuranyl group, benzothionyl group, benzopyranyl group, benzooxazolyl group, benzoimidazolyl group, and the like. It is done.

In addition, the part of (R ⁴¹ —O) _{p in} formula (I) may be two or three groups within the above range. Specific examples include random or block combinations of ethyleneoxy and propyleneoxy groups, ethyleneoxy and isopropyloxy groups, ethyleneoxy and butyleneoxy groups, ethyleneoxy groups and isobutylene groups, and the like. . In the present invention, the surfactant having a polyoxyalkylene ether group is used alone or in a composite system, and it is effective to add 1 to 30% by mass, preferably 2 to 20% by mass in the developer. If the addition amount is small, the developability is deteriorated. On the other hand, if the amount is too large, the development damage becomes strong and the printing durability of the printing plate is lowered.

Examples of the nonionic surfactant having a polyoxyalkylene ether group represented by the above formula (I) include polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene cetyl ether, and polyoxyethylene stearyl ether. Polyoxyethylene aryl ethers such as polyoxyethylene phenyl ether and polyoxyethylene naphthyl ether, polyoxyethylene alkyl aryl ethers such as polyoxyethylene methyl phenyl ether, polyoxyethylene octyl phenyl ether and polyoxyethylene nonyl phenyl ether Kind.
These surfactants can be used alone or in combination. Further, the content of these surfactants in the developer is preferably in the range of 0.1 to 20% by mass in terms of active ingredients.

The pH of the developer used for the plate making of the photosensitive lithographic printing plate of the present invention is not particularly limited, but is preferably 11.0 to 12.7, more preferably 11.5 to 12.5. If it is 11.0 or more, image formation can be ensured, and if it is 12.7 or less, over-development is not caused, and no damage is caused by development in the exposed portion.
The conductivity of the developer is preferably 3 to 30 mS / cm. If it is 3 mS / cm or more, the photopolymerizable photosensitive layer on the surface of the aluminum support can be surely eluted, and there is no stain on printing, and if it is 30 mS / cm or less, the salt concentration does not become too high. The elution rate of the photopolymerizable photosensitive layer does not become extremely slow, and no remaining film is formed in the unexposed area. Particularly preferred conductivity is in the range of 5-20 mS / cm.

The development of the photosensitive lithographic printing plate in the present invention is carried out according to a conventional method, for example, by immersing the exposed photosensitive lithographic printing plate in a developer at a temperature of about 0 to 60 ° C., preferably about 15 to 40 ° C. For example, rubbing with.
Further, when developing using an automatic developing machine, the developing solution becomes fatigued according to the amount of processing, so that the processing capability may be restored by using a replenishing solution or a fresh developing solution.
The photosensitive lithographic printing plate thus developed is washed with water and surface active as described in JP-A-54-8002, JP-A-55-115045, JP-A-59-58431, etc. It is post-treated with a rinsing solution containing an agent and the like, a desensitizing solution containing gum arabic, starch derivatives and the like. In the present invention, these treatments can be used in various combinations for the post-treatment of the photosensitive lithographic printing plate.
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.
The planographic printing plate obtained by such processing is loaded on an offset printing machine and used for printing a large number of sheets.

EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to these.
[Example of support]
(Support 1: Anodized aluminum support)
An aluminum plate made of material 1S having a thickness of 0.30 mm was used with a No. 8 nylon brush and an aqueous suspension of 800 mesh Pamiston, and its surface was grained and washed thoroughly with water. After etching by immersing in 10% sodium hydroxide at 70 ° C. for 60 seconds, washed with running water, neutralized with 20% HNO ₃ and washed with water. This was subjected to an electrolytic surface roughening treatment in a 1% nitric acid aqueous solution with a galvanostatic quantity of 300 coulomb / dm ² using a sinusoidal alternating current under the condition of V _A = 12.7V. When the surface roughness was measured, it was 0.45 μm (Ra indication). Next, after dipping in a 30% H ₂ SO ₄ aqueous solution and desmutting at 55 ° C. for 2 minutes, a cathode was placed on the grained surface in 33 ° C., 20% H ₂ SO ₄ aqueous solution to obtain a current density. When anodized at 5 A / dm ² for 50 seconds, the thickness was 2.6 g / m ² . This was designated as Support 1.

(Support 2)
A solution of the following polymer (P1) was applied to the support (1) using a bar coater so that the dry coating amount was 2 mg / m ^2, and dried at 80 ° C. for 20 seconds.

[Undercoat liquid]
Polymer (P1) 0.3g
60.0g of pure water
Methanol 939.7g

    Structural formula of polymer (P1)

[Photopolymerizable photosensitive composition P-1]
A photosensitive composition (1) having the following composition was coated on the support (2) using a bar coater and then dried at 100 ° C. for 1 minute. The mass of the photosensitive composition after drying was 1.3 g / m ² .

Ethylenically unsaturated bond-containing compound (A1) 1.5 parts by weight Polymer binder (B1) 1.6 parts by weight Sensitizing dye (D29) 0.15 parts by weight Photopolymerization initiator (C1) 0.12 parts by weight ε -Phthalocyanine (F1) dispersion 0.02 parts by mass Sensitization aid (G1) 0.5 parts by mass Fluorine nonionic surfactant Megafac F-780F
(Dai Nippon Ink Chemical Co., Ltd.) 0.02 parts by mass Methyl ethyl ketone 26.0 parts by mass Propylene glycol monomethyl ether 26.3 parts by mass

  The ethylenically unsaturated bond-containing compound (A1), polymer binder (B1), photopolymerization initiator (C1), and ε-phthalocyanine (F1) used in the photopolymerizable photosensitive composition P-1 ), The sensitization aid (G1) was a compound of the following chemical formula. As the sensitizing dye, (D29) shown in the specific example was used.

On this photosensitive layer,
Polyvinyl alcohol (saponification degree 98 mol%, polymerization degree 500) 5.0 parts by mass
EMALEX 710 (Nonionic surfactant manufactured by Nippon Emulsifier Co., Ltd.) 0.09 parts by mass Pure water 94.91 parts by mass A protective layer aqueous solution was applied with a bar coater so that the dry coating mass was 2.5 g / m ^2. And dried at 120 ° C. for 1 minute to obtain a photosensitive lithographic printing plate.

(Exposure, plate making and characteristic curve creation)
The above-described photosensitive lithographic printing original plate is loaded into a Violet semiconductor laser setter Vx9600 (InGaN-based semiconductor laser 405 nm ± 10 nm emission / output 30 mW) manufactured by FUJIFILM Electronic Imaging Ltd. Solid exposure at a resolution of 2438 dpi with an exposure amount of 90 μJ / cm ² Went. Subsequently, the exposure dose was reduced to 1 / √2 of the initial exposure dose, 63.64 μJ / cm ² , and then the exposure of 1 / √2 = 45 μJ / cm ² , followed by 10 times in 10 steps. Exposure was performed. The minimum exposure was 3.98 μJ / cm ² (the third decimal place was rounded off).
The plate after exposure is automatically sent to the connected automatic processor LP1250PLX, heated at 100 ° C. for 10 seconds, the PVA protective layer is washed away with water, and subsequently developed at 28 ° C. for 20 seconds. The developer was prepared by diluting a developer DV-2 manufactured by Fuji Photo Film Co., Ltd. five times with water. The developed plate was rinsed in a rinse bath, sent to a gumming bath, and a solution obtained by diluting a gum solution FP-2W manufactured by Fuji Photo Film Co., Ltd. with water twice. The plate after gumming is discharged after hot air drying.

The density of the image formed by changing the exposure amount of the plate after plate making in 10 steps is measured with a reflection densitometer made by GRETAG-MaCbeth, and the characteristic curve created by the above method is shown in FIG. Show.
From FIG. 3, it is calculated as E _G = 11.20 μJ / cm ² .

Examples 1-3, Comparative Examples 1-2
(Exposure amount and plate performance calculated from characteristic curve)
From the obtained characteristic curve above, using the same light-sensitive lithographic printing plate as in Example 1, 110μJ / cm ^2: 9.8 times E _G, 90μJ / cm ² as a second embodiment: the E _G 8 2 times, Example 3 as 65 μJ / cm ² : 5.8 times E _G , Comparative Example 1 as 40 μJ / cm ² : E _G 3.6 times, Comparative Example 2 as 140 μJ / cm ² : E _G 12 An image containing a halftone dot image test chart from 1% to 99% of 175 lines was formed by applying an exposure of 5 times. The exposure and development were performed using a Violet semiconductor laser setter Vx9600 manufactured by FUJIFILM Electronic Imaging Ltd and an LP1250PLX automatic developing machine in the same manner as when the characteristic curve was obtained.

(Evaluation of halftone dot reproducibility and printing durability)
The obtained halftone image was visually confirmed with 2 × highlight dot using a 50 × magnifying glass and the opening of 98% halftone dot in the shadow portion. Those with 2% halftone dots were marked with ◯, and those without images were marked with x. Similarly, with respect to the shadow part 98%, the open one was marked with ◯, and the collapsed one was marked with x. In the portion evaluated as x, halftone dot%, in which a predetermined halftone dot was reproduced as a reference, was entered. These results are summarized in Table 1.

  Further, the plates of Examples 1 to 3 and Comparative Examples 1 and 2 were printed using a DIC-GEOS (N) black ink manufactured by Dainippon Ink & Chemicals, Inc. using a Lithlon 26 printer manufactured by Komori Corporation. The printing durability was evaluated based on the number of printed sheets when it was visually confirmed that the density of the solid image started to become thin. The results are also summarized in Table 1.

Examples 4-10, Comparative Examples 3-8
The sensitizing dye in the photopolymerization type photosensitive composition P-1 of the photosensitive lithographic printing plate used in Examples 1 to 3 was changed as shown in Table 1, and photosensitive compositions P-2 to 4 were obtained. , using a photopolymerization type photosensitive lithographic printing plate which is provided as a photosensitive layer which, in the same manner as in example 1-3 to obtain the E _G, and set the exposure amount based thereon platemaking. The performance evaluation results are shown in Table-1.

Examples 11-13, Comparative Examples 9-10
<Liquid composition 2 for undercoat>
The following sol solution was applied and dried on the support 1 used in Examples 1 to 10.
(Support 3)
The SG method liquid composition (sol solution) was prepared by the following procedure.
The following composition was weighed in a beaker and stirred at 25 ° C. for 20 minutes.
Si (OC ₂ H ₅ ) ₄ 38 g
3-Methacryloxypropyltrimethoxysilane 13g
85% phosphoric acid aqueous solution 12g
Ion exchange water 15g
Unichemical Co., Ltd. Phosmer PE 15.2g
Methanol 100g

The solution having the above composition was transferred to a three-necked flask, and the three-necked flask equipped with a reflux condenser was immersed in an oil bath at room temperature. While stirring the contents of the three-necked flask with a magnetic stirrer, the temperature was raised to 50 ° C. in 30 minutes. While maintaining the bath temperature at 50 ° C., the mixture was further reacted for 1 hour to obtain a liquid composition (sol solution). The obtained sol solution was diluted with methanol / ethylene glycol = 20/1 (mass ratio) to 0.5 mass%, applied with a bar, and dried at 80 ° C. for 1 minute. The coating amount at that time was 4 mg / m ² . This coating amount was obtained by obtaining the amount of Si element by fluorescent X-ray analysis and using it as the coating amount. This support is referred to as support 3.

[Photopolymerizable photosensitive composition P-5]
Using a bar coater on the support (3), the ethylenically unsaturated bond-containing compound (A1) and the polymer binder (B1) of the photopolymerizable composition P-4 of Examples 8 to 10 above. The photosensitive composition P-5 having the following composition, which was changed to the following A2 and B2, respectively, was applied, followed by drying at 120 ° C. for 1 minute. The mass of the photosensitive composition after drying was 1.3 g / m ² .

(Photopolymerizable photosensitive composition P-5)
Ethylenically unsaturated bond-containing compound (A2) 0.16 parts by mass Polymer binder (B2) 0.15 parts by mass Photopolymerization initiator (C1) 0.15 parts by mass Sensitizing dye (D29) 0.24 parts by mass Increase Sensitizing dye (D32) 0.06 parts by mass Sensitization aid (G1) 0.50 parts by mass Fluorosurfactant 0.02 parts by mass (Megafac F-780F manufactured by Dainippon Ink & Chemicals, Inc.)
Thermal polymerization inhibitor 0.01 parts by mass (N-nitrosohydroxylamine aluminum salt)
ε-type copper phthalocyanine dispersion (F1) 0.2 parts by mass Methyl ethyl ketone 26.0 parts by mass Propylene glycol monomethyl ether 26.3 parts by mass

On this photosensitive layer,
Polyvinyl alcohol (saponification degree 98 mol%, polymerization degree 500) 5.0 parts by mass
EMALEX 710 (Nonionic surfactant manufactured by Nippon Emulsifier Co., Ltd.) 0.09 parts by mass Pure water 94.91 parts by mass An aqueous solution was applied with a bar coater so that the dry coating mass was 2.5 g / m ^2. It was dried at 0 ° C. for 1 minute to obtain a photosensitive lithographic printing plate.

Using the resulting photopolymerizable photosensitive lithographic printing plate in the same manner as in Example 1-3 to obtain the E _G, and setting an exposure amount based thereon. From the obtained characteristic curve, it was found that E _G = 10.50 μJ / cm ² . Using the same light-sensitive lithographic printing plate, as an example 11, 100μJ / cm ^2: 9.5 times E _G, 80μJ / cm ² as in Example 12: 7.6 times E _G, 60μJ as Example 13 / cm ^2: 5.7 times E _G, 40μJ / cm ² Comparative example 7: 3.8 times E _G, as a comparative example 8, 120μJ / cm ^2: giving 11.4 times the exposure E _G Thus, an image including a halftone dot image test chart of 100% 1% to 99% was formed. Table 2 shows the printing plates made and their performance evaluation results.

As is apparent from Table, be minimized exposure 10.0 times less than 4.0 times or more E _G necessary for image formation was determined image exposure amount from the characteristic curve of the photopolymerization type photosensitive lithographic printing plate Thus, it can be seen that high printing durability and excellent small dot reproducibility can be realized.

It is a diagram for explaining how to determine the characteristic curve and E _G of the photopolymerization type photosensitive lithographic printing plate. In the case of using the normalized image density is a diagram for explaining how to determine the characteristic curve and E _G of the photopolymerization type photosensitive lithographic printing plate. It is a characteristic curve of the photopolymerization type photosensitive lithographic printing plate produced in the Example.

Claims (3)

A photopolymerization type photosensitive lithographic printing plate containing a photosensitive layer having a spectral sensitivity in a wavelength range of at least 360 nm to 450 nm is image-exposed with a semiconductor laser beam oscillating in a wavelength range of 360 nm to 450 nm, developed, and processed into a lithographic plate. In the plate making method of a photopolymerization type photosensitive lithographic printing plate for producing a printing plate, the image exposure amount in the image exposure is determined from the characteristic curve of the photopolymerization type photosensitive lithographic printing plate, and is the minimum exposure necessary for image formation photopolymerizable photosensitive lithographic printing plate making method of which is a 4.0-fold to 10.0-fold less than the amount E _G. 2. The photopolymerizable photosensitive lithographic plate according to claim 1, wherein the photosensitive layer of the photopolymerizable photosensitive lithographic printing plate comprises the following (i), (ii) and (iii): How to make a printing plate.
(I) a sensitizing dye having an absorption maximum in a wavelength range of 360 nm to 450 nm,
(Ii) a photopolymerization initiator, and (iii) an addition polymerizable compound having an ethylenically unsaturated double bond. 3. The plate making method of a photopolymerization type photosensitive lithographic printing plate according to claim 2, wherein the photopolymerization initiator is a titanocene compound.

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