Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41C—PROCESSES FOR THE MANUFACTURE OR REPRODUCTION OF PRINTING SURFACES
  • B41C1/00—Forme preparation
  • B41C1/10—Forme preparation for lithographic printing; Master sheets for transferring a lithographic image to the forme
  • B41C1/1008—Forme preparation for lithographic printing; Master sheets for transferring a lithographic image to the forme by removal or destruction of lithographic material on the lithographic support, e.g. by laser or spark ablation; by the use of materials rendered soluble or insoluble by heat exposure, e.g. by heat produced from a light to heat transforming system; by on-the-press exposure or on-the-press development, e.g. by the fountain of photolithographic materials
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41C—PROCESSES FOR THE MANUFACTURE OR REPRODUCTION OF PRINTING SURFACES
  • B41C1/00—Forme preparation
  • B41C1/10—Forme preparation for lithographic printing; Master sheets for transferring a lithographic image to the forme
  • B41C1/1008—Forme preparation for lithographic printing; Master sheets for transferring a lithographic image to the forme by removal or destruction of lithographic material on the lithographic support, e.g. by laser or spark ablation; by the use of materials rendered soluble or insoluble by heat exposure, e.g. by heat produced from a light to heat transforming system; by on-the-press exposure or on-the-press development, e.g. by the fountain of photolithographic materials
  • B41C1/1016—Forme preparation for lithographic printing; Master sheets for transferring a lithographic image to the forme by removal or destruction of lithographic material on the lithographic support, e.g. by laser or spark ablation; by the use of materials rendered soluble or insoluble by heat exposure, e.g. by heat produced from a light to heat transforming system; by on-the-press exposure or on-the-press development, e.g. by the fountain of photolithographic materials characterised by structural details, e.g. protective layers, backcoat layers or several imaging layers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41C—PROCESSES FOR THE MANUFACTURE OR REPRODUCTION OF PRINTING SURFACES
  • B41C2201/00—Location, type or constituents of the non-imaging layers in lithographic printing formes
  • B41C2201/04—Intermediate layers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41C—PROCESSES FOR THE MANUFACTURE OR REPRODUCTION OF PRINTING SURFACES
  • B41C2201/00—Location, type or constituents of the non-imaging layers in lithographic printing formes
  • B41C2201/14—Location, type or constituents of the non-imaging layers in lithographic printing formes characterised by macromolecular organic compounds, e.g. binder, adhesives
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41C—PROCESSES FOR THE MANUFACTURE OR REPRODUCTION OF PRINTING SURFACES
  • B41C2210/00—Preparation or type or constituents of the imaging layers, in relation to lithographic printing forme preparation
  • B41C2210/02—Positive working, i.e. the exposed (imaged) areas are removed
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41C—PROCESSES FOR THE MANUFACTURE OR REPRODUCTION OF PRINTING SURFACES
  • B41C2210/00—Preparation or type or constituents of the imaging layers, in relation to lithographic printing forme preparation
  • B41C2210/06—Developable by an alkaline solution
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41C—PROCESSES FOR THE MANUFACTURE OR REPRODUCTION OF PRINTING SURFACES
  • B41C2210/00—Preparation or type or constituents of the imaging layers, in relation to lithographic printing forme preparation
  • B41C2210/22—Preparation or type or constituents of the imaging layers, in relation to lithographic printing forme preparation characterised by organic non-macromolecular additives, e.g. dyes, UV-absorbers, plasticisers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41C—PROCESSES FOR THE MANUFACTURE OR REPRODUCTION OF PRINTING SURFACES
  • B41C2210/00—Preparation or type or constituents of the imaging layers, in relation to lithographic printing forme preparation
  • B41C2210/24—Preparation or type or constituents of the imaging layers, in relation to lithographic printing forme preparation characterised by a macromolecular compound or binder obtained by reactions involving carbon-to-carbon unsaturated bonds, e.g. acrylics, vinyl polymers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41C—PROCESSES FOR THE MANUFACTURE OR REPRODUCTION OF PRINTING SURFACES
  • B41C2210/00—Preparation or type or constituents of the imaging layers, in relation to lithographic printing forme preparation
  • B41C2210/26—Preparation or type or constituents of the imaging layers, in relation to lithographic printing forme preparation characterised by a macromolecular compound or binder obtained by reactions not involving carbon-to-carbon unsaturated bonds
  • B41C2210/262—Phenolic condensation polymers, e.g. novolacs, resols

Definitions

• the present invention relates to a positive planographic printing plate precursor whose solubility in an aqueous alkaline solution is improved by infrared ray exposure, and particularly to a positive planographic printing plate precursor that can directly make a plate, that is, capable of so-called "direct plate-making", by scanning with an infrared laser light based on digital signals from a computer or the like.
• a positive planographic printing plate material for use with an infrared laser which uses the aforementioned infrared laser whose light-emitting region is in the infrared region as an exposure light source, is a planographic printing plate material that has a binder resin soluble in an aqueous alkaline solution, an IR dye which absorbs light and generates heat, and the like as essential components.
• the IR dye and the like in the positive planographic printing plate material for use with an infrared laser works as a dissolution inhibitor that substantially reduces the solubility of the binder resin by an interaction with the binder resin.
• the exposed portion because the IR dye and the like absorb light and generate heat, the interaction between the IR dye and the like and the binder resin is weakened. Consequently, during developing, the exposed portion (non-image portion) dissolves in an alkaline developer, thus forming a planographic printing plate.
• JP-A Japanese Patent Application Laid-Open
• US 2002/0086233 A1 discloses a photosensitive resin composition containing a high molecular compound having at least a fluoro aliphatic group, and a group represented by formula -L-P, wherein L represents a divalent organic group connected to the skeleton of the high molecular compound and P represents an aromatic group having a carboxyl group at the ortho-position.
• US 2003/0162126 A1 discloses a positive working, multi-layer, thermally imageable element, the imageable element comprising a substrate having a hydrophilic surface, an underlayer comprising a first polymeric material over the hydrophilic surface, and a top layer comprising a second polymeric material over the underlayer, in which the second polymeric material is crosslinked, the top layer is ink receptive and insoluble in an alkaline developer, the top layer and the underlayer are each removable by the alkaline developer following thermal exposure of the element and the element comprises a photothermal conversion material.
• the object to be attained by the present invention is to overcome the above-mentioned weaknesses of the related art to provide a positive planographic printing plate precursor capable of forming an image using an infrared laser that not only can form a strong film being excellent in chemical resistance and alkaline developer resistance, but has a recording layer whose alkaline developer resistance is rapidly removed by infrared-light exposure, and has superior printing durability and chemical resistance, and excellent discrimination.
• the planographic printing plate precursor of the present invention has a substrate and a positive recording layer prepared on the substrate, the recording layer comprises (A) a polymer having a urea bond in a side chain, (B) a photothermal conversion agent, and (C) an amino compound having a methylol group or an alkoxymethyl group, and the solubility thereof in an alkaline developer is improved by light-exposure or heating.
• a polymer having a urea bond in a side chain, which is contained in the positive recording layer is improved in terms of chemical resistance and strength (hardness) in a non-exposed portion by the properties of the urea bond group introduced in the side chain. Moreover, because the urea bond itself does not act as a group soluble in an aqueous alkaline solution, the alkaline developer resistance of the polymer is not impaired.
• the non-exposed portion of the planographic printing plate precursor having such a positive recording layer maintains a strong film having excellent alkaline developer resistance and chemical resistance.
• the solubility of the exposed portion in the developer is remarkably improved owing to the release of the interaction and the hydrophilicity that the compounds have by nature. It is thought that, therefore, the difference of the solubility of the non-exposed portion and that of the exposed portion in an alkaline developer is large, and thereby the planographic printing plate precursor has excellent image reproducibility and printing durability.
• a strong film having excellent chemical resistance and alkaline developer resistance is formed in the non-exposed portion in the planographic printing plate precursor of the present invention. And, when this non-exposed portion is exposed to infrared light, the solubility of the exposed area to a developer is remarkably improved.
• a positive planographic printing plate precursor for use with an infrared laser that has wide development latitude and has excellent chemical resistance and printing durability can be provided.
• the planographic printing plate precursor of the invention has a substrate and a positive recording layer prepared on the substrate, and the recording layer comprises (A) a polymer having a urea bond in a side chain (hereinafter, it may be referred to as "a specific polymer"), (B) a photothermal conversion agent, and (C) an amino compound having a methylol group or an alkoxymethyl group (hereinafter, it may be referred to as "a specific amino compound”), and the solubility thereof in an alkaline developer is improved by light-exposure or heating.
• a specific polymer a polymer having a urea bond in a side chain
• a photothermal conversion agent a photothermal conversion agent
• an amino compound having a methylol group or an alkoxymethyl group hereinafter, it may be referred to as "a specific amino compound”
• the specific polymer (A) used in the invention is not especially limited as long as it is a polymer having a urea bond in a side chain, among such polymers, it is preferable to use a polymer that is insoluble in water and soluble to aqueous alkaline solution.
• polymers known polymers can be used.
• vinyl polymerized or condensation polymerized high-molecular compounds having a constitutional unit shown by any of the following formulas of (1-a) to (1-c), or novolac resins having a urea bond in the side chain can be preferably cited.
• R 1 and R 2 indicate independently a hydrogen atom, a halogen atom, an alkyl group, an aryl group, a carboxyl group, or their salts, respectively.
• R 3 indicates a hydrogen atom, a halogen atom, an alkyl group, or an aryl group.
• X indicates a bivalent linkage group, of which suitable examples are an alkylene group, a phenylene group or the like that may have a substituent.
• Y indicates a bivalent aromatic group that may have a substituent, of which suitable examples are a phenylene group, a naphthylene group or the like that may have a substituent.
• the constitutional unit in the copolymer is preferably 10 to 80 mol % in the feed ratio, more preferably 15 to 70 mol %, and in particular preferably 20 to 60 mol%.
• the content is less than 10 mol %, the specific polymer is poor in chemical resistance, and when more than 80 mol %, the solubility to aqueous alkaline solution is low and the sensitivity may be low.
• the method for manufacturing the high-molecular compounds having a constitutional unit shown by any of the formulas of (1-a) to (1-c) is not especially limited, they can be manufactured by various sorts of known methods, for example, a method of polymerizing a polymerizable monomer using a polymerization initiator in a solvent, and the like can be cited.
• the polymerizable monomer is a monomer having one or more urea bonds and one or more polymerizable unsaturated bonds in one molecule, for example, compounds shown by the following formula (1-d) and the like can be suitably cited.
• R 4 indicates a hydrogen atom or an alkyl group.
• X indicates a bivalent linkage group, for example, an alkylene group or a phenylene group that may have a substituent can be cited.
• Y indicates a bivalent aromatic group that may have a substituent, for example, a phenylene group, a naphthylene group or the like that may have a substituent can be cited.
• Compounds shown by the formula (1-d) include, for example, acrylate derivatives such as 1-(N'-(4-hydroxyphenyl) ureido) methyl acrylate, 1-(N'-(3-hydroxyphenyl) ureido) methyl acrylate, 1-(N'-(2-hydroxyphenyl) ureido) methyl acrylate, 1-(N'-(3-hydroxy-4-methylphenyl) ureido) methyl acrylate, 1-(N'-(2-hydroxy-5-methylphenyl) ureido) methyl acrylate, 1-(N'-(5-hydroxynaphthyl) ureido) methyl acrylate, 1-(N'-(2-hydroxy-5-phenylphenyl) ureido) methyl acrylate, 2-(N'-(4-hydroxyphenyl) ureido) ethyl acrylate, 2-(N'-(3-hydroxyphenyl) urei
• the above-mentioned polymerizable monomers have a characteristic absorption band based on the urea bond in the area of 1600 to 1700 cm -1 in their infrared absorption spectrum, they can be identified by the measurement of their infrared absorption spectrums. Moreover, they can be identified by the measurement of their melting points, proton NMR and the like.
• 2-(N'-(4-hydroxyphenyl) ureido) ethyl methacrylate has a melting point of 131 to 133°C, and can be identified by the IR absorption spectrum based on the hydroxyl group and the urea bond.
• polymerizable monomers preferably include, for example, acrylates having an acid group such as 2-(N'-(4-carboxylphenyl) ureido) ethyl acrylate, 2-(N'-(4-sulfamoylphenyl) ureido) ethyl acrylate, 2-(N'-(sulfophenyl) ureido) ethyl acrylate, and 2-(N'-(4-phosphonophenyl) ureido) ethyl acrylate; methacrylates having an acid group such as 2-(N'-(4-carboxylphenyl) ureido) ethyl methacrylate, 2-(N'-(4-sulfamoylphenyl) ureido) ethyl methacrylate, 2-(N'-(4-sulfophenyl)
• 2-(N'-(4-carboxyphenyl) ureido) ethyl methacrylate has a decomposition temperature of 220°C, and can be identified by the absorption of IR spectrum based on the carboxyl group and the urea bond.
• the method for manufacturing the above-mentioned polymerizable monomers is not especially limited.
• the known manufacturing method of reacting an isocyanate compound shown by the following formula (1-e) with an amine compound shown by the following formula (1-f), and the like can be suitably cited.
• R 5 indicates a hydrogen atom or an alkyl group.
• X is the same as that in formula (1-d).
• R 6 indicates a hydrogen atom, or an alkyl group that may have a substituent.
• Y is the same as that in formula (1-d).
• Z indicates a hydroxyl group, a carboxyl group, or a sulfonamide group.
• a polymerizable monomer shown by formula (1-d) can be suitably obtained by the use of a compound of formula (1-e) and a compound of formula (1-f) in which Z is a hydroxyl group and R 6 is a hydrogen atom.
• reaction can be more effectively advanced by excessively using an amine compound shown by formula (1-f) and by slowly adding an isocyanate compound shown by formula (1-e) to the amine compound.
• the above-mentioned solvent is not especially limited as long as it is a known organic solvent.
• solvents suitably include those having no active hydrogen atom, for example, ethylene dichloride, cyclohexanone, methyl ethyl ketone, acetone, methanol, ethanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, 2-methoxyethyl acetate, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, 1-methoxy-2-propanol acetate, 1-methoxy-2-propyl acetate, 1-ethoxy-2-propyl acetate, dimethyl sulfoxide, toluene, ethyl acetate, methyl lactate, ethyl lactate, and dioxane.
• One of these solvents may be used separately, or 2 or more of them may be used at the same time.
• the reaction only has to be performed until the isocyanate compound shown by formula (1-e) runs out, or the amount of the urea bond becomes constant, and the time is usually 15 minutes to 24hours.
• the temperature of the reaction is preferably 0 to 40°C.
• the reaction mixture is neutralized with an acidic compound, including dilute hydrochloric acid, to make the salt of the amine compound shown by formula (1-f), and then water washing, filtering, and vacuum drying of the reaction mixture will make the above-mentioned polymerizable monomer have high purity.
• an acidic compound including dilute hydrochloric acid
• the specific polymer (A) concerned in the invention may be a homopolymer or a copolymer of 2 or more monomers from among the polymerizable monomers, each of which contains the urea bond (for example, monomers shown by formulae (1-a) to (1-c), and the like), the polymer is preferably a copolymer with a compound that has one or more polymerizable unsaturated bond(s) and does not contain a urea bond in view of printing durability.
• the copolymer may be any of a block copolymer, a random copolymer, a graft copolymer and the like.
• the above-mentioned copolymer is preferably copolymerized by use of 10 to 80 mol % of the polymerizable monomer in a total 100 mol % of the polymerizable monomer and a compound that has one or more polymerizable unsaturated bond(s) and does not contain a urea bond.
• the polymerizable compounds that have an unsaturated bond and do not contain a urea bond include, for example, acrylate compounds such as methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, amyl acrylate, ethylhexyl acrylate, octyl acrylate, t-octyl acrylate, chloroethyl acrylate, 2,2-dimethylhydroxypropyl acrylate, 5-hydroxypentyl acrylate, trimethylolpropane monoacrylate, pentaerythritol monoacrylate, glycidyl acrylate, benzyl acrylate, methoxybenzyl acrylate, and tetrahydro acrylate; aryl acrylate compounds such as phenyl acrylate, and furfuryl acrylate; methacrylate compounds such as methyl methacrylate, ethyl methacrylate, propyl
• N-aryl methacrylamide compounds such as N-phenyl methacrylamide, and N-naphthyl methacrylamide; N,N-dialkyl methacrylamide compounds such as N,N-diethyl methacrylamide, N,N-dipropyl methacrylamide, and N,N-dibutyl methacrylamide; N,N-diaryl methacrylamide compounds such as N,N-diphenyl methacrylamide; methacrylamide derivatives such as N-hydroxyethyl-N-methyl methacrylamide, N-methyl-N-phenyl methacrylamide, and N-ethyl-N-phenyl methacrylamide; allyl compounds such as allyl acetate, allyl caproate, allyl caprylate, allyl laurate, allyl palmitate, allyl stearate, allyl benzoate, allyl acetoacetate, allyl lactate, and allyl oxyethanol;
• (meth)acrylate compounds (meth)acrylamide compounds, maleimide compounds, and (meth)acrylonitrile compounds are especially preferable.
• both or any one of acrylate and methacrylate when both or any one of acrylate and methacrylate are indicated, they may be described as (meth)acrylate.
• both or any one of acrylic acid and methacrylic acid may be called as (meth)acrylic acid, both or any one of acrylonitrile and methacrylonitrile as (meth)acrylonitrile, and both or any one of acrylamine and methacrylamide as (meth)acrylamide, respectively.
• the molecular weight of the specific polymer (A) used in the present invention is preferably 2,000 or more in weight-average molecular weight, and more preferably 3,000 to 500,000, while in number-average molecular weight, it is preferably 1,000 or more, and more preferably 2,000 to 400,000.
• the content of the specific polymer (A) used in the present invention in the recording layer is 3 to 97 mass % in the total solid content of the compositions constituting the recording layer, and preferably 10 to 90 mass %, and more preferably 30 to 80 mass %.
• the recording layer used in the present invention needs to contain a photothermal conversion agent (B) in addition to the specific polymer (A).
• a photothermal conversion agent usable in the invention it is possible to use any compound that generates heat by being exposed to a light source used for image forming.
• the planographic printing plate precursor of the present invention can form an image by being exposed to an infrared laser, it is preferable to use an infrared-light absorbing agent that has a light absorption range in the infrared region of 700 nm or more, preferably 750 to 1,200 nm, and that reveals a photothermal conversion function through light in the wavelengths of this range.
• various sorts of dyes or pigments that absorb light in the above-mentioned wavelength band and generate heat.
• dyes such as azo dyes, metal complex salt azo dyes, pyrazolone azo dyes, naphthoquinone dyes, anthraquinone dyes, phthalocyanine dyes, carbonium dyes, quinoneimine dyes, methine dyes, cyane dyes, squarylium pigments, pyrilium salts, metal thiolate complexes, oxomol dyes, diimonium dyes, aminium dyes, and croconium dyes.
• dyes such as azo dyes, metal complex salt azo dyes, pyrazolone azo dyes, naphthoquinone dyes, anthraquinone dyes, phthalocyanine dyes, carbonium dyes, quinoneimine dyes, methine dyes, cyane dyes, squarylium pigments, pyrilium salts, metal thiolate complexes, oxomol dyes, diimonium dyes,
• the dye include cyanine dyes described in JP-A Nos. 58-125246 , 59-84356 , 59-202829 , and 60-78787 ; methine dyes described in JP-A Nos. 58-173696 , 58-181690 , and 58-194595 ; naphthoquinone dyes described in JP-ANos. 58-112793 , 58-224793 , 59-48187 , 59-73996 , 60-52940 , and 60-63744 ; squalirium dyes described in JP-A No. 58-112792 ; and cyanine dyes described in GB Patent No. 434,875 .
• the dye include near infrared absorbing sensitizers described in U.S. Patent No. 5,156,938 ; substituted arylbenzo(thio)pyrylium salts described in U.S. Patent No. 3,881,924 ; trimethinethiapyrylium salts described in JP-ANo. 57-142645 ( U.S. Patent No. 4,327,169 ); pyrylium type compounds described in JP-A Nos. 58-181051 , 58-220143 , 59-41363 , 59-84248 , 59-84249 , 59-146063 , and 59-146061 ; cyanine dyes described in JP-A No.
• JP-B Japanese Patent Application Publication
• the dye include near infrared absorbing dyes represented by formulae (I) and (II) as described in U.S. Patent No. 4,756,993 .
• cyanine dyes particularly preferable are cyanine dyes, phthalocyanine dyes, oxonol dyes, squarylium dyes, pyrylium salts, thiopyrylium dyes, and nickel thiolate complexes.
• Dyes represented by the following general formulae (a) to (e) are also preferable since such dyes are excellent in terms of photothermal conversion efficiency.
• the cyanine dyes represented by the following general formula (a) are most preferable because: when the dyes are used with the image forming material of the invention, they manifest a high degree of interaction with an alkali-soluble resin; and the dyes are excellent in terms of stability and economy.
• X 1 represents a hydrogen atom, a halogen atom, -NPh 2 , X 2 -L 1 (wherein X 2 represents an oxygen atom or a sulfur atom, L 1 represents a hydrocarbon group having 1 to 12 carbon atoms, an aromatic cyclic group having a heteroatom, or a hydrocarbon group containing a heteroatom and having 1 to 12 carbon atoms, and the heteroatom referred to herein is N, S, O, a halogen atom, or Se), or a group represented by the following: wherein Xa - has the same definition as Za - , which will be described at a later time, and R a represents a substituent selected from a hydrogen atom, an alkyl group, an aryl group, a substituted or unsubstituted amino group, or a halogen atom; R 1 and R 2 each independently represents a hydrocarbon group having 1 to 12 carbon atoms, and from the viewpoint of the storage stability of the photo
• Ar 1 and Ar 2 which may be the same or different, each represents an aromatic hydrocarbon group which may have a substituent.
• the aromatic hydrocarbon group include benzene and naphthalene rings.
• the substituent include hydrocarbon groups having 12 or less carbon atoms, halogen atoms, and alkoxy groups having 12 or less carbon atoms.
• Y 1 and Y 2 which may be the same or different, each represents a sulfur atom, or a dialkylmethylene group having 12 or less carbon atoms.
• R 3 and R 4 which may be the same or different, each represents a hydrocarbon group which has 20 or less carbon atoms and may have a substituent.
• substituents include alkoxy groups having 12 or less carbon atoms, a carboxyl group, and a sulfo group.
• R 5 , R 6 , R 7 and R 8 which may be the same or different, each represents a hydrogen atom, or a hydrocarbon group having 12 or less carbon atoms, and since the raw materials thereof can easily be obtained, each preferably represents a hydrogen atom.
• Za - represents a counter anion. However, in a case where the cyanine dye represented by general formula (a) has an anionic substituent in the structure thereof and there is accordingly no need to neutralize electric charges in the dye, Za - is not required.
• Za - is preferably an ion of a halogen, perchlorate, tetrafluroborate, hexafluorophosphate, carboxylate or sulfonate.
• Za - is preferably a halogen ion, or an organic acid ion such as a carboxylic acid ion or sulfonic acid ion, more preferably a sulfonic acid ion, and even more preferably an arylsulfonic acid ion.
• cyanine dye represented by general formula (a) examples include dyes in JP-A No. 2001-133969 (paragraphs [0017] to [0019]), JP-A No. 2002-40638 (paragraphs [0012] to [0038]), and JP-A No. 2002-23360 (paragraphs [0012] to [0023]), as well as dyes illustrated below.
• L represents a methine chain having 7 or more conjugated carbon atoms, and the methine chain may have one or more substituent.
• the substituents may be bonded to each other to form a cyclic structure.
• Zb + represents a counter cation.
• the counter cation include ammonium, iodonium, sulfonium, phosphonium and pyridinium ions, and alkali metal cations (such as Ni + , K + and Li + ).
• R 9 to R 14 and R 15 to R 20 each independently represents a substituent selected from hydrogen atom, halogen atom, and cyano, alkyl, aryl, alkenyl, alkynyl, carbonyl, thio, sulfonyl, sulfinyl, oxy and amino groups; or a substituent obtained by combining two or three among these substituents. Two or three of R 9 to R 14 and R 15 to R 20 may be bonded to each other to form a cyclic structure.
• Y 3 and Y 4 each independently represent an oxygen, sulfur, selenium or tellurium atom;
• M represents a methine chain having 5 or more conjugated carbon atoms;
• R 21 to R 24 and R 25 to R 28 which may be the same or different, each represents a hydrogen or halogen atom, or a cyano, alkyl, aryl, alkenyl, alkynyl, carbonyl, thio, sulfonyl, sulfinyl, oxy or amino group; and
• Za - represents a counter anion, and has the same meaning as Za - in general formula (a).
• R 29 to R 31 each independently represents a hydrogen atom, an alkyl group or an aryl group
• R 33 and R 34 each independently represents an alkyl group, a substituted oxy group, or a halogen atom
• n and m each independently represents an integer of 0 to 4
• R 29 and R 30 , or R 31 and R 32 may be bonded to each other to form a ring, or R 29 and/or R 30 may be bonded to R 33 to form a ring and R 31 and/or R 32 may be bonded to R 34 to form a ring.
• R 33 's and R 34 's are present, R 33 's may be bonded to each other to form a ring, or R 34 's may be bonded to each other to form a ring.
• X 2 and X 3 each independently represents a hydrogen atom, an alkyl group or an aryl group, and at least one of X 2 and X 3 represents a hydrogen atom or an alkyl group.
• Q represents a trimethine group or a pentamethine group which may have a substituent, and may be combined with a bivalent organic group to form a cyclic structure.
• Zc - represents a counter anion and has the same meanings as Za - in general formula (a).
• R 35 to R 50 each independently represents a hydrogen or halogen atom, or a cyano, alkyl, aryl, alkenyl, alkynyl, hydroxyl, carbonyl, thio, sulfonyl, sulfinyl, oxy or amino group, or an onium salt structure, each of which may have a substituent;
• M represents two hydrogen atoms, a metal atom, a halo metal group, or an oxy metal group.
• the metal contained therein include atoms in IA, IIA, IIIB and IVB groups in the periodic table, transition metals in the first, second and third periods therein, and lanthanoid elements.
• preferable are copper, magnesium, iron, zinc, cobalt, aluminum, titanium, and vanadium.
• the pigment used as the infrared absorbent in the invention may be a commercially available pigment or a pigment described in publications such as Color Index (C.I.) Handbook, "Latest Pigment Handbook” (edited by Japan Pigment Technique Association, and published in 1977 ), “ Latest Pigment Applied Technique” (by CMC Publishing Co., Ltd. in 1986 ), and “ Printing Ink Technique” (by CMC Publishing Co., Ltd. in 1984 ).
• C.I. Color Index
• the pigment examples include black pigments, yellow pigments, orange pigments, brown pigments, red pigments, purple pigments, blue pigments, green pigments, fluorescent pigments, metal powder pigments, and polymer-bonded dyes.
• insoluble azo pigments azo lake pigments, condensed azo pigments, chelate azo pigments, phthalocyanine pigments, anthraquinone pigments, perylene and perynone pigments, thioindigo pigments, quinacridone pigments, dioxazine pigments, isoindolinone pigments, quinophthalone pigments, dyeing lake pigments, azine pigments, nitroso pigments, nitro pigments, natural pigments, fluorescent pigments, inorganic pigments, and carbon black.
• carbon black is preferable.
• These pigments may be used with or without surface treatment.
• surface treatment include a method of coating the surface of the pigments with resin or wax; a method of adhering a surfactant onto the surface; and a method of bonding a reactive material (such as a silane coupling agent, an epoxy compound, or a polyisocyanate) to the pigment surface.
• a reactive material such as a silane coupling agent, an epoxy compound, or a polyisocyanate
• a particle diameter of pigments is preferably in a range of 0.01 ⁇ m to 10 ⁇ m, further preferably in a range of 0.05 ⁇ m to 1 ⁇ m, particularly preferably in a range of 0.1 ⁇ m to 1 ⁇ m.
• the method for dispersing the pigment may be a known dispersing technique used to produce ink or toner.
• a dispersing machine which can be used, include an ultrasonic disperser, a sand mill, an attriter, a pearl mill, a super mill, a ball mill, an impeller, a disperser, a KD mill, a colloid mill, a dynatron, a three-roll mill, and a pressing kneader. Details are described in " Latest Pigment Applied Technique” (by CMC Publishing Co., Ltd. in 1986 ).
• the pigment or dye can be added to the recording layer in a ratio of 0.01 to 50%, preferably 0.1 to 10%, and more preferably 0.5 to 10% in the case of dye and 0.1 to 10% in the case of pigment by mass, relative to the total solid contents of the recording layer.
• the recording layer needs to contain (C) an amino compound having a methylol group or an alkoxymethyl group (the specific amino compound) together with the (A) the specific polymer and (B) a photothermal conversion agent.
• the specific amino compound is preferably an amino compound having at least 2 groups selected from the group comprising of methylol groups and alkoxymethyl groups.
• the specific amino compound in the present invention is an amino compound containing the structure shown by the following formula (I).
• T 1 and T 2 independently indicate a hydrogen atom, an alkyl group, an alkenyl group, an acyl group, and an acetyl group, respectively.
• T 1 and T 2 in formula (I) are alkyl groups
• the number of carbon atoms in the alkyl group is preferably 1 to 8, and more preferably 1 to 4.
• a methyl group, an ethyl group, an isopropyl group, a tertiary butyl group, and the like are preferable.
• T 1 and T 2 are alkenyl groups
• the number of carbon atoms in the alkenyl group is preferably 2 to 18, and more preferably 2 to 4.
• T 1 and T 2 are acyl groups
• the number of carbon atoms in the acyl group is preferably 2 to 18, and more preferably 2 to 4.
• Concrete examples of the structure shown by the formula (I) include a methoxymethylolamine group, a dimethoxymethylamino group, a dimethylolamino group (a dihydroxyamino group), and a diethoxymethylamino group.
• amino compounds shown by the following formula (II) are preferable.
• R 1 to R 6 independently indicate a hydrogen atom, an alkyl group, an alkenyl group, an acyl group, and an acetyl group, respectively.
• a hydrogen atom, an alkyl group, an alkenyl group, an acyl group, and an acetyl group in R 1 to R 6 of the formula (II) have the same meaning as a hydrogen atom, an alkyl group, an alkenyl group, an acyl group, and an acetyl group in T 1 and T 2 of formula (I).
• the specific amino compound in the present invention is preferably added by 0.5 to 30 mass % in the total solid content constituting the recording layer in view of printing durability and chemical resistance, and more preferably added by the ratio of 1 to 10 mass %.
• any of the other resins soluble in an aqueous alkaline solution can be contained in the recording layer if needed.
• other resins soluble in an aqueous alkaline solution are not particularly limited, but general-purpose novolac resins are preferable.
• novolac resins for example, phenol-formaldehyde resin, m-cresol-formaldehyde resin, p-cresol-formaldehyde resin, m-/p-mixed cresol-formaldehyde resin, phenol/cresol (any of m-, p-, o-, m-/p-mixed, m-/o-mixed, and o-/p-mixed may be accepted) mixed formaldehyde resin can be cited.
• One of these compounds may be used separately, and 2 or more may be used at the same time.
• novolac resins those with weight-average molecular weight of 1,500 or more and number-average molecular weight of 300 or more are preferable, and those with weight-average molecular weight of 3,000 to 300,000, number-average molecular weight of 500 to 250,000 and the degree of dispersion (weight-average molecular weight/number-average molecular weight) of 1.1 to 10 are more preferable.
• resins which are soluble in an aqueous alkaline solution and can be used with the essential components (A) to (C) resins having any of the acidic groups shown in the following (1) to (6) in the principal chain and/or a side chain of the polymer can be cited.
• Ar represents a divalent aryl linking group that may be substituted
• R represents a hydrogen atom or a hydrocarbon group that may be substituted
• alkali-soluble resins having acidic groups selected from the (1) to (6) alkali-soluble resins having (1) a phenol group, (2) a sulfonamide group and (3) an active imide group are preferable.
• alkali-soluble resins having (1) a phenol group or (2) a sulfone amide group are most preferable from a viewpoint of sufficient solubility in an alkaline developer, developing latitude, and film strength.
• alkali-soluble resin comprising the acidic group selected from the above-mentioned (1) to (6)
• the following can be exemplified.
• X 1 and X 2 each represents, independently, -O-or -NR 7 - R 1 and R 4 each represents, independently, a hydrogen atom or -CH 3 .
• R 2 , R 5 , R 9 , R 12 and R 16 each represents, independently, an alkylene group of a carbon number of 1 to 12 optionally having a substituent, a cycloalkylene group, an arylene group or an aralkylene group.
• R 3 , R 7 and R 13 each represents, independently, a hydrogen atom, an alkyl group of a carbon number of 1 to 12 optionally having a substituent, a cycloalkyl group, an aryl group or an aralkyl group.
• R 6 and R 17 each represents, independently, an alkyl group of a carbon number of 1 to 12 optionally having a substituent, a cycloalkyl group, an aryl group, or an aralkyl group.
• R 8 , R 10 and R 14 each represents, independently, a hydrogen atom or -CH 3 .
• R 11 and R 15 each represents, independently, a single bond, or an alkylene group of a carbon number of 1 to 12 optionally having a substituent, a cycloalkylene group, an arylene group or an aralkylene group.
• Y 1 and Y 2 each represents, independently, a single bond or -CO-.
• m-aminosulfonylphenyl methacrylate, N-(p-aminosulfonylphenyl)methacrylamide, and N-(p-aminosulfonylphenyl)acrylamide can be suitably used.
• alkali-soluble resin having an active imide group in the item (3) examples include a polymer having as the main component a minimum structural unit derived from a compound having an active imide group.
• examples of such a compound include a compound having in the molecule thereof one or more active imide groups represented by the following structural formula and one or more unsaturated groups which can be polymerized with the active imide group(s):
• N-(p-toluenesulfonyl)methacrylamide, N-(p-toluenesulfonyl)acrylamide and others can be preferably used.
• Examples of the monomer having a carboxylic acid group in the item (4) include compounds each having in the molecule thereof one or more carboxylic acid groups and one or more unsaturated groups which can be polymerized with the carboxylic acid group(s).
• Examples of the monomer having a sulfonic acid group in the item (5) include compounds each having in the molecule thereof one or more sulfonic acid groups and one or more unsaturated groups which can be polymerized with the sulfonic acid group(s).
• Examples of the monomer having a phosphoric acid group in the item (6) include compounds each having in the molecule thereof one or more phosphoric acid group and one or more unsaturated groups which can be polymerized with the phosphoric acid group(s).
• the minimum constituent unit comprising acidic group selected from (1) to (6) is not necessarily limited to one particular unit, but can be those obtained by copolymerizing two or more types of minimum constituent units comprising the same acidic group or two or more types of minimum constituent units comprising different acidic groups.
• the above-mentioned copolymer contains the compound having the acidic group selected from (1) to (6) to be copolymerized in an amount preferably 10% by mole or more, more preferably 20% by mole or more. If it is less than 10% by mole, the development latitude tends to be improved insufficiently.
• monomer components which are copolymerized with the polymerizable monomers having a phenolic hydroxyl group, a sulfonamide group, or an activated imide group for example, monomers shown in the following (m 1) to (m 12) can be used, though the monomer components should not be limited to them.
• the homopolymers or copolymers of the above-mentioned polymerizable monomers having a phenolic hydroxyl group or an activated imide group are preferable, and the homopolymers or copolymers of the polymerizable monomers having a sulfonamide group such as m-aminosulfonylphenyl methacrylate, N-(p-aminosulfonylphenyl) methacrylamide, N-(p-aminosulfonylphenyl) acrylamide, or the like are especially preferable.
• those with a weight-average molecular weight of 2,000 or more and a number-average molecular weight of 500 or more are preferable, and those with a weight-average molecular weight of 5,000 to 300,000 and a number-average molecular weight of 800 to 250,000 and a degree of dispersion (weight-average molecular weight/number-average molecular weight) of 1.1 to 10 are more preferable.
• One of these resins soluble in an aqueous alkaline solution may be used respectively, or two or more types thereof may be used in combination.
• the amount of these resins to be added is 5 to 90 mass % in the total solid amount of the above-mentioned recording layer, preferably 10 to 85 mass %, and in particular preferably 15 to 80 mass %. If the amount added of a resin soluble in an aqueous alkaline solution is insufficient, when using the resin as the recording layer in a planographic printing plate precursor, the durability of the recording layer is deteriorated. If the amount is too much, the content of "a specific polymer (A)" as an essential component in the invention is relatively reduced, whereby it is difficult to obtain the effect of the present invention. Both states of which are not preferable.
• a so-called dissolution inhibitor that enhances the effect of inhibiting dissolution of the alkaline solution-soluble polymer (alkaline soluble resin) in the developer when added, such as other onium salts, aromatic sulfone compounds, aromatic sulfonate ester compounds, polyfunctional amine compounds, or the like.
• a substance that is heat-decomposing and substantially lowers the solubility of the alkaline soluble resin in an un-decomposed state such as onium salts, o-quinonediazide compounds, alkyl sulfonate ester, and the like is preferable for the aim of improving the solubility inhibiting property of the image area with regard to the developer.
• onium salt used in the invention include diazonium salts described in S. I. Schlesinger, Photogr. Sci. Eng., 18, 387 (1974 ), T. S. Bal et al., Polymer, 21, 423 (1980 ), and JP-ANo. 5-158230 ; ammonium salts described in U.S. Patent Nos. 4,069,055 and 4,069,056 , and JP-A No. 3-140140 ; phosphonium salts described in D. C. Necker et al., Macromolecules, 17, 2468 (1984 ), C. S. Wen et al., Teh, Proc. Conf. Rad.
• diazonium salts and quaternary ammonium salts are especially preferable.
• diazonium salts the diazonium salts shown by the formula (I) described in JP-A No. 5-158230 and the diazonium salts shown by the formula (1) described in JP-ANo. 11-143064 are preferable, and diazonium salts which have a small absorption wavelength in the visible radiation region and shown by the formula (1) described in JP-A No. 11-143064 are most preferable.
• quaternary ammonium salts quaternary ammonium salts described as (1) to (10) in [Formula 5] and [Formula 6] in JP-ANo. 2002-229186 are preferable.
• Examples of the counter ion of the onium salt include tetrafluoroboric acid, hexafluorophosphoric acid, triisopropylnaphthalenesulfonic acid, 5-nitro-o-toluenesulfonic acid, 5-sulfosalicylic acid, 2,5-dimethylbenzenesulfonic acid, 2,4,6-trimethylbenzenesulfonic acid, 2-nitrobenzenesulfonic acid, 3-chlorobenzenesulfonic acid, 3-bromobenzenesulfonic acid, 2-fluorocaprylnaphthalenesulfonic acid, dodecylbenzenesulfonic acid, 1-naphthol-5-sulfonic acid, 2-methoxy-4-hydroxy-5-benzoyl-benzenesulfonic acid, and p-toluenesulfonic acid.
• hexafluorophosphoric acid, and alkylaromatic sulfonic acids such as triisopropylnaphthalenesulfonic acid and 2,5-dimethylbezenesulfonic acid are particularly preferable.
• the quinonediazide is preferably an o-quinonediazide compound.
• the o-quinonediazide compound used in the invention is a compound having at least one o-quinonediazide group and having an alkali-solubility increased by being thermally decomposed.
• the compound may be any one of compounds having various structures.
• the o-quinonediazide compound assists the solubility of the photosensitive material both from the viewpoint of the effects of being thermally decomposed, and thereby losing the function of suppressing the dissolution of the binder, and the effect that the o-quinonediazide itself is changed into an alkali-soluble material.
• o-quinonediazide compound used in the invention include compounds described in J. Coser, "Light-Sensitive Systems” (John Wiley & Sons. Inc.), pp. 339-352 .
• Particularly preferable are sulfonic acid esters or sulfonamides of o-quinonediazide made to react with various aromatic polyhydroxy compounds or with aromatic amino compounds.
• esters made from benzoquinone-(1,2)-diazidesulfonic acid chloride or naphthoquinone-(1,2)-diazide-5-sulfonic acid chloride and pyrogallol-acetone resin, as described in JP-B No. 43-28403 ; and an ester made from benzoquinone-(1,2)-diazidesulfonic acid chloride or naphthoquinone-(1,2)-diazide-5-sulfonic acid chloride and phenol-formaldehyde resin as in described in US 3,046,120 and US 3,188,210 .
• Additional preferable examples include an ester made from naphthoquinone-(1,2)-diazide-4-sulfonic acid chloride and phenol-formaldehyde resin or cresol-formaldehyde resin; and an ester made from naphthoquinone-(1,2)-diazide-4-sulfonic acid chloride and pyrogallol-acetone resin.
• the amount of onium salts and/or o-quinone diazide compounds that is added, which are decomposable dissolution inhibitors is preferable in the range of 1 to 10 mass % in the total solid content of the recording layer, is further preferably in the range of 1 to 5 mass %, and especially preferably in the range of 1 to 2 mass %. Though these compounds can be used alone, they may be used as a mixture of several of these compounds.
• the amount added of additives other than o-quinone diazide compounds that is added is preferably 0.1 to 5 mass %, further preferably 0.1 to 2 mass %, and in particular preferably 0.1 to 1.5 mass %.
• the additives and binders in the present invention are preferably contained in the same layer.
• a dissolution inhibitor not having resolvability may be used at the same time.
• Preferable dissolution inhibitors include compounds described in detail in JP-A No. 10-268512 such as sulfonates, phosphates, aromatic carboxylates, aromatic disulfones, carboxylic acid anhydrides, aromatic ketones, aromatic aldehydes, aromatic amines, and aromatic ethers, compounds similarly described in detail in JP-A No. 11-190903 such as acid coloring dyestuffs having a lactone skeleton, a N,N-diaryl amide skeleton, and diaryl methylimino skeleton and combining a coloring agent, and nonionic surfactants similarly described in detail in JP-ANo. 2000-105454 .
• cyclic acid anhydrides, phenol compounds, organic acids and the like can be cited in view of improving sensitivity.
• surfactants, image coloring agents and plasticizers, which will be described later, can be also used as an additive in the positive recording layer.
• cyclic acid anhydride examples include phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, 3,6-endooxy- ⁇ 4-tetrahydrophthalic anhydride, tetrachlorophthalic anhydride, maleic anhydride, chloromaleic anhydride, ⁇ -phenylmaleic anhydride, succinic anhydride, and pyromellitic anhydride which are described in U.S. Patent No. 4,115,128 .
• phenolic compound examples include bisphenol A, p-nitrophenol, p-ethoxyphenol, 2,4,4'-trihydroxybenzophenone, 2,3,4-trihydroxybenzophenone, 4-hydroxybenzophenone, 4,4',4"-trihydroxytriphenylmethane, and 4,4',3",4"-tetrahydroxy-3,5,3',5'-tetramethyltriphenylmethane.
• organic acid examples include sulfonic acids, sulfinic acids, alkylsulfuric acids, phosphonic acids, phosphates, and carboxylic acids, which are described in JP-A No. 60-88942 or 2-96755 .
• the ratio thereof in the recording layer is preferably from 0.05 to 20%, more preferably from 0.1 to 15%, and even more preferably from 0.1 to 10% by mass.
• an epoxy compound may be appropriately added to the composition, depending on the objective: an epoxy compound; a vinyl ether; a phenol compound having a hydroxymethyl group and a phenol compound having an alkoxymethyl group, described in JP-A No. 8-276558 ; and a cross-linkable compound having an effect of suppressing dissolution in an alkali, described in JP-A No. 11-160860 , and which was previously proposed by the present inventors.
• a printing-out agent for obtaining a visible image immediately after the photosensitive composition of the invention has been heated by exposure to light or a dye or pigment as an image coloring agent.
• a typical example of a printing-out agent is a combination of a compound which is heated by exposure to light, thereby emitting an acid (an optically acid-generating agent), and an organic dye which can form salts (salt formable organic dye).
• JP-A Nos. 50-36209 and 53-8128 examples thereof include combinations of an o-naphthoquinonediazide-4-sulfonic acid halogenide with a salt-formable organic dye, described in JP-A Nos. 50-36209 and 53-8128 ; and combinations of a trihalomethyl compound with a salt-formable organic dye, described in each of JP-A Nos. 53-36223 , 54-74728 , 60-3626 , 61-143748 , 61-151644 and 63-58440 .
• the trihalomethyl compound is classified into an oxazol compound or a triazine compound. Both of the compounds provide excellent in stability over the passage of time and produce a vivid printed-out image.
• a dye different from the above-mentioned salt-formable organic dye may be used.
• a dye, and of the salt-formable organic dye include oil-soluble dyes and basic dyes.
• Oil yellow #101, Oil Yellow #103, Oil Pink #312, Oil Green BG, Oil Blue BOS, Oil Blue #603, Oil Black BY, Oil Black BS, and Oil Black T-505 each of which is manufactured by Orient Chemical Industries Ltd.
• Dyes described in JP-A No. 62-293247 are particularly preferable. These dyes may be added to the photosensitive composition at a ratio of 0.01 to 10% by mass, and preferably 0.1 to 3% by mass, relative to the total solid contents therein.
• a plasticizer may be added to the uppermost layer of the recording layer of the planographic printing plate precursor of the invention to give flexibility to a coating film.
• the plasticizer include oligomers and polymers of butyl phthalyl, polyethylene glycol, tributyl citrate, diethyl phthalate, dibutyl phthalate, dihexyl phthalate, dioctyl phthalate, tricresyl phosphate, tributyl phosphate, trioctyl phosphate, tetrahydrofurfuryl oleate, and acrylic acid and methacrylic acid.
• the planographic printing plate precursor of the present invention can be formed in such a way that the above-mentioned constituent in the recording layer is dissolved in a solvent and the solution is applied on a suitable substrate. Moreover, a protective layer, a intermediate resin layer, a backcoating layer and the like, which are provided in the planographic printing plate precursor according to the purpose and will be described later, can also be formed similarly.
• Examples of a solvent which can be used in the present invention include, though not limited thereto, ethylene dichloride, cyclohexanone, methyl ethyl ketone, methanol, ethanol, propanol, ethylene glycol monomethyl ether, 1-methoxy-2-propanol, 2-methoxyethyl acetate, 1-methoxy-2-propyl acetate, dimethoxyethane, methyl lactate, ethyl lactate, N,N-dimethylacetamide, N,N-dimethylformamide, tetramethylurea, N-methylpyrrolidone, dimethylsulfoxide, sulfolane, ⁇ -butyrolactone and toluene. These solvents may be used either singly or in combination.
• the concentration of the above components (total solid content including the additives) in the solvent is preferably 1 to 50 mass%.
• the recording layer in the planographic printing plate precursor of the present invention can be used in any of a single layer structure, a phase separation structure, or a multilayer structure.
• the recording layer can use a single layer type recording layer, for example, in the photosensitive layers described in JP-A No. 7-285275 and International Publication No. 97/39894 pamphlet, as a phase separation type recording layer, for example, in the photosensitive layer described in JP-A No. 11-44956 , or as a multilayer type recording layer, for example, in the photosensitive layers described in JP-A No. 11-218914 , U.S. Patent Nos. 6352812B1 , 6352811B1 , 6358669B1 and 6534238B1 , and European Patent Application No. 864420B1 , but is not limited to them.
• the components (A) to (C), which are essential components in the present invention may be contained in any layer without being limited to being in a lower layer or the top layer, but are preferably in the lower layers in view of their effect.
• the coated amount of the recording layer (solid content) on the substrate obtained after coating and drying is different according to the use, but generally, the amount of film after drying (the total amount in the case of a multilayer structure) is preferably 0.5 to 5.0 g/m 2 , and more preferably 0.6 to 2.0 g/m 2 .
• the support used in the planographic printing plate precursor of the present invention is a plate having dimensional stability.
• a plate satisfying required physical properties such as strength and flexibility can be used without any restriction.
• Examples thereof include paper, plastic (such as polyethylene, polypropylene or polystyrene)-laminated papers, metal plates (such as aluminum, zinc and copper plates), plastic films (such as cellulose biacetate, cellulose triacetate, cellulose propionate, cellulose lactate, cellulose acetate lactate, cellulose nitrate, polyethylene terephthalate, polyethylene, polystyrene, polypropylene, polycarbonate, and polyvinyl acetate films), and papers or plastic films on which, as described above, a metal is laminated or vapor-deposited.
• plastic such as polyethylene, polypropylene or polystyrene
• metal plates such as aluminum, zinc and copper plates
• plastic films such as cellulose biacetate, cellulose triacetate, cellulose propionate, cellulose lactate, cellulose
• the support is preferably a polyester film or an aluminum plate, and more preferably an aluminum plate, since an aluminum plate is superior in terms of dimensional stability and is also relatively inexpensive.
• the aluminum plate include a pure aluminum plate and alloy plates made of aluminum as a main component with a very small amount of other elements.
• a plastic film on which aluminum is laminated or vapor-deposited may also be used.
• a particularly preferable aluminum plate in the present invention is a pure aluminum plate; however, since from the viewpoint of refining a completely pure aluminum cannot be easily produced, a very small amount of other elements may also be contained in the plate.
• the aluminum plate used as the support is not specified in terms of the composition thereof. Thus, aluminum plates which are conventionally known can be appropriately used.
• the thickness of the aluminum plate used in the present invention is from about 0.1 to 0.6 mm, preferably from 0.15 to 0.4 mm, and more preferably from 0.2 to 0.3 mm.
• the aluminum plate may optionally be subjected to degreasing treatment, in order to remove rolling oil or the like on the surface, with a surfactant, an organic solvent, an aqueous alkaline solution or the like.
• the surface-roughening treatment of the aluminum surface can be performed by various methods such as a mechanical surface-roughening method, a method of dissolving and roughening the surface electrochemically, and a method of dissolving the surface selectively in a chemical manner.
• Mechanical surface-roughening methods which can be used may be known methods, such as a ball polishing method, a brush polishing method, a blast polishing method or a buff polishing method.
• An electrochemical surface-roughening method may be a method of performing surface-roughening in an electrolyte of hydrochloric acid or nitric acid, by use of an alternating current or a direct current. As disclosed in JP-A No. 54-63902 , a combination of the two kinds of methods may be used.
• An aluminum plate whose surface is roughened as described above is if necessary subjected to alkali-etching treatment and neutralizing treatment. Thereafter, an anodizing treatment is optionally applied in order to improve the water holding capacity and wear resistance of the surface.
• the electrolyte used in the anodizing treatment of the aluminum plate is any one selected from various electrolytes which can form a porous oxide film. Among which in general use are electrolytes of sulfuric acid, phosphoric acid, oxalic acid, chromic acid, or a mixed acid thereof. The concentration of the electrolyte may be appropriately decided depending on the kind of electrolyte selected.
• Treatment conditions for anodization cannot be specified as a general rule since conditions vary depending on the electrolyte used; however, the following range of conditions are generally suitable: an electrolyte concentration of 1 to 80% by mass, a solution temperature of 5 to 70°C, a current density of 5 to 60 A/dm 2 , a voltage of 1 to 100 V, and an electrolyzing time of 10 seconds to 5 minutes. If the amount of anodic oxide film is less than 1.0 g/m 2 , printing resistance is inadequate or non-image portions of the planographic printing plate tend to become easily damaged and the so-called "blemish stains", resulting from ink adhering to damaged portions at the time of printing, are easily generated.
• hydrophilicity treatment may be an alkali metal silicate (for example, an aqueous sodium silicate solution) method, as disclosed in U.S. Patent Nos. 2,714,066 , 3,181,461 , 3,280,734 , and 3,902,734 .
• the support is subjected to an immersing treatment or an electrolyzing treatment with an aqueous sodium silicate solution.
• the following methods may also be used: a method of treating the support with potassium fluorozirconate, as disclosed in JP-B No. 36-22063 , or with polyvinyl phosphonic acid, as disclosed in U.S. Patent Nos. 3,276,868 , 4,153,461 , and 4,689,272 .
• an undercoat layer may further be disposed, when required, between the support and the recording layer (lower layer).
• the undercoat layer offers the benefit that: the undercoat layer functions as a heat-insulating layer between the support and the lower layer so that the heat generated by the exposure of the infrared laser does not diffuse into the support, thus providing higher sensitivity due to the efficient use of the heat.
• the recording layer is situated still at the exposure surface or near thereat and thus the sensitivity to the infrared laser can be favorably maintained.
• the recording layer itself is impervious to the alkaline developer and functions as a protective layer for the undercoat layer, the stability of image development is improved while images of excellent discrimination are formed and the stability over time can be ensured.
• the undercoat layer itself, which exists adjacent to the support, is an alkaline soluble polymer having favorable solubility in the developer, and thus is rapidly dissolved without generating a residual film even if a developer with lowered activity is used, contributing the improvement of the developability. That is, the undercoat layer is useful.
• various organic compounds can be used as components of the undercoat layer.
• examples thereof include carboxymethylcellulose, dextrin, gum arabic, phosphonic acids having an amino group, such as 2-aminoethylphosphonic acid, organic phosphonic acids which may have a substituent, such as phenyl phosphonic acid, naphthylphosphonic acid, alkylphosphonic acid, glycerophosphonic acid, methylenediphosphonic acid and ethylenediphosphonic acid, organic phosphoric acids which may have a substituent, such as phenylphosphoric acid, naphthylphosphoric acid, alkylphosphoric acid and glycerophosphoric acid, organic phosphinic acids which may have a substituent, such as phenylphosphinic acid, naphthylphosphinic acid, alkylphosphinic acid and glycerophosphinic acid, amino acids such as glycine and ⁇ -alanine, and hydrochlorides of amines having
• the appropriate coated amount of undercoat layer is from 2 to 200 mg/m 2 , and preferably from 5 to 100 mg/m 2 .
• the coating amount is less than 2 mg/m 2 , sufficient printing endurance cannot be obtained.
• an image is formed with heat.
• Concrete methods for forming the image include direct image-like recording by a thermal recording head and the like, scanning exposure by an infrared laser, high illumination flash exposure by a xenon discharge lamp and the like, and infrared lamp exposure, but it is preferable to use exposure with solid high-energy infrared lasers such as a semiconductor laser, YAG laser, or the like which emit infrared rays of 700 to 1200 nm wavelength.
• the output power of a laser is preferably 100 mW or more, and it is preferable to use a multibeam laser device to shorten the exposure time. Furthermore, the exposure time per pixel is preferably within 20 ⁇ s and energy radiated onto a recording material is preferably 10 to 500 mJ/cm 2 .
• the developer which can be used for the planographic printing plate precursor of the invention is a developer having a pH of 9.0 to 14.0, preferably 12.0 to 13.5.
• the developer the category of which includes not only developer but also replenisher hereinafter, may be an aqueous alkaline solution that has been known so far.
• Examples thereof include aqueous solutions of inorganic alkali salts such as sodium silicate, potassium silicate, sodium triphosphate, potassium triphosphate, ammonium triphosphate, sodium biphosphate, potassium biphosphate, ammonium biphosphate, sodium carbonate, potassium carbonate, ammonium carbonate, sodium hydrogencarbonate, potassium hydrogencarbonate, ammonium hydrogencarbonate, sodium borate, potassium borate, ammonium borate, sodium hydroxide, ammonium hydroxide, potassium hydroxide and lithium hydroxide; and organic alkali agents such as monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine, triethylamine, monoisopropylamine, diisopropylamine, ethyleneimine, ethylenediamine, and pyridine.
• inorganic alkali salts such as sodium silicate, potassium silicate, sodium triphosphate, potassium triphosphate, ammonium triphosphate, sodium biphosphate, potassium biphosphate, ammonium biphosphate,
• one preferable developer which exhibits the effects of the invention effectively, is an aqueous solution having a pH of 12 or more and comprising alkali silicate as a base or alkali silicate obtained by mixing a base with a silicon compound.
• the aqueous solution is the so-called "silicate developer”.
• Another preferable developer is the so-called “non-silicate developer", which does not comprise any alkali silicate but comprises a nonreducing sugar (organic compound having a buffer effect) and a base.
• the developing power of aqueous solution of alkali metal silicate can be adjusted by adjusting the ratio between silicon oxide SiO 2 and alkali metal oxide M 2 O, which are components of the silicate, (generally, the mole ratio of [SiO 2 ]/[M 2 O]), and the concentration of the alkali metal silicate.
• the ratio between silicon oxide SiO 2 and alkali metal oxide M 2 O, which are components of the silicate (generally, the mole ratio of [SiO 2 ]/[M 2 O])
• concentration of the alkali metal silicate concentration of the alkali metal silicate.
• the following is preferably used: an aqueous solution of sodium silicate wherein the mole ratio of SiO 2 /Na 2 O ([SiO 2 [/[Na 2 O]] is from 1.0 to 1.5 and the content by percentage of SiO 2 is from 1 to 4% by mass, as disclosed in JP-A No.
• an aqueous solution of alkali metal silicate wherein the mole ratio of SiO 2 /M is from 0.5 to 0.75 (that is, the mole ratio of SiO 2 /M 2 O is from 1.0 to 1.5), the content by percentage of SiO 2 is from 1 to 4% by mass, and the content by percentage of potassium in all alkali metals is 20% by gram atom, as disclosed in JP-B No. 57-7427 .
• non-silicate developer which does not comprise any alkali silicate but comprises a nonreducing sugar and a base, is also preferable for being used to develop the first and second planographic printing plate precursors of the invention.
• this developer is used to develop any one of the planographic printing plate precursors, ink-adsorbing power of the recording layer can be kept better without deteriorating the surface of the recording layer.
• a planographic printing plate material generally has a narrow development latitude and experiences a large change in scanning width and the like depending on the pH value of the developer
• a non-silicate developer contains a non-reducing sugar having a buffering property to suppress the pH fluctuation
• use of a non-silicate developer is advantageous, as compared with using a developing liquid containing a silicate.
• a non-reducing sugar is unlikely to contaminate a conductivity sensor, a pH sensor, or the like which control the liquid activity, as compared with a silicate, a non-silicate developer is more advantageous than a silicate developer in this regard, as well.
• the discrimination-improving effect of a non-silicate developer is remarkable in the planographic printing plate material of the present invention. It is assumed that such a good discrimination-improving effect is obtained because contact with the developer (permeation), which is an important aspect in the present invention, is made moderate and the difference between the exposed areas and the non-exposed areas can be expressed more easily.
• the aforementioned non-reducing sugar belongs to sugars which do not have free aldehyde groups or ketone groups and show a non-reducing property; these sugars are classified into trehalose-type oligo-saccharides in which reducing groups are bonded to each other, glucosides in which reducing group of sugars and non-sugar material are bonded, and sugar alcohols formed by reducing sugars with hydrogenation, each of which can be used suitably in the present invention.
• non-reducing sugars described in Japanese Patent Application Laid-Open No. 8-305039 can be used suitably.
• Examples of the trehalose type oligosaccharides include saccharose and trehalose.
• Examples of the glucosides include alkylglucosides, phenolglucosides, and mustard seed oil glucoside.
• Examples of the sugar alcohols include D, L-arabitol, ribitol, xylitol, D, L-sorbitol, D, L-mannitol, D, L-iditol, D, L-talitol, dulcitol, and allodulcitol.
• maltitol obtained by hydrogenating maltose that is a disaccharide
• a reductant obtained by hydrogenating an oligosaccharide i.e., reduced starch syrup
• sugar alcohol and saccharose are more preferable.
• D-sorbitol, saccharose, and reduced starch syrup are even more preferable since they have buffer effect within an appropriate pH range and are inexpensive.
• non-reducing sugars may be used alone or two or more may be used in combination.
• the content of the non-reducing sugar in the non-silicate developer is preferably from 0.1 to 30 mass% and, more preferably, from 1 to 20 mass%. When the content is less than 0.1 mass%, a sufficient buffering effect may not be obtained. When the content exceeds 30 mass%, making high concentrations may become difficult, resulting in higher cost of the materials.
• the base combined with the nonreducing sugar(s) may be an alkali agent that has been known so far.
• alkali agent examples thereof include inorganic alkali agents such as sodium hydroxide, potassium hydroxide, lithium hydroxide, trisodium phosphate, tripotassium phosphate, triammonium phosphate, disodium phosphate, dipotassium phosphate, diammonium phosphate, sodium carbonate, potassium carbonate, ammonium carbonate, sodium hydrogencarbonate, potassium hydrogencarbonate, ammonium hydrogencarbonate, sodium borate, potassium borate and ammonium borate; and organic alkali agents such as monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine, triethylamine, monoisopropylamine, diisopropylamine, triisopropylamine, n-butylamine, monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine,
• the bases may be used each alone or two or more may be used in combination.
• sodium hydroxide or potassium hydroxide is preferred.
• a non-silicate developer whose main component is an alkaline metal salt of a non-reducing sugar.
• an alkaline buffer solution comprising a weak acid and a strong base other than the non-reducing sugar can be used in combination as the non-silicate developer.
• the weak acid those having a dissociation constant (pKa) of 10.0 to 13.2 are preferred, and can be selected from among those described, for example, in " Ionization Constants of Organic Acids in Aqueous Solution” published by Pergamon Press , or the like.
• various surfactants or organic solvents can be added to the developer and a replenisher as required.
• the surfactant anionic, cationic, nonionic, and amphoteric surfactants are preferred.
• organic solvent reducing agents such as hydroquinone, resorcin, and sodium salts or potassium salts of inorganic acids such as sulfurous acid or hydrogen sulfurous acid, and further, organic carboxylic acids, defoamers, softening agents for hard water, can be added to the developer and the replenisher.
• planographic printing plate developed using the developer and the replenisher described above is post-treated with washing water, a rinsing solution containing a surfactant or the like, and a desensitizing solution containing gum arabic or starch derivative. Various combinations of these can be used for the post-treatment.
• anionic, cationic, nonionic and amphoteric surfactants can be exemplified.
• reducing agents of such as hydroquinone, resorcin, sodium salt or potassium salt of inorganic acids such as sulfurous acid, hydrogen sulfurous acid, and further organic carboxylic acid, defoaming agents, and water hardening or softening agents may be added.
• the printing plate treated by using the developer or the replenisher is washed with water and post-treated with rinsing solutions containing the surfactants or the like, and desensitizing solutions containing gum arabic and starch derivatives.
• the post-treatment of the image recording material of the invention can be carried out by using these treatments in combinations.
• An automatic developing apparatuses generally comprise a development section and a post-treatment section. More specifically, an automatic developing apparatus includes a unit for transferring the printing plates, tanks for respective treatment solutions, and a spraying apparatus. The automatic developing apparatus transfers the exposed printing plates horizontally and at the same time carries out development treatment by spraying the respective treatment solutions pumped up by pumps, to the printing plate, through spray nozzles. Recently, there is also known a method for carrying out treatment by transporting the printing plates by under-solution guide rolls while the printing plates are immersed in the treatment solution tanks filled with the treatment solutions. In such automatic treatment, the replenishers may be replenished to the respective treatment solutions depending on the treatment quantity, operation times, and the like. Alternatively, so-called disposable treatment method in which treatment is carried out using substantially unused treatment solutions can be employed.
• the planographic printing plate precursor of the present invention is imagewise exposed, developed, washed with water and/or rinsed and/or gum-coated to obtain a planographic printing plate. If unnecessary image portions (e.g. film edge trace of a master film) are present in the planographic printing plate, the unnecessary image portions are erased. Such erasing is preferably carried out by a method of applying an erasing solution as described in JP-B No. 2-13293 to the unnecessary image portions and washing with water after a prescribed duration. A method of radiating active light beam led through optical fibers to the unnecessary image portions and then carrying out development as described in JP-A No. 59-174842 may also be employed.
• unnecessary image portions e.g. film edge trace of a master film
• Such erasing is preferably carried out by a method of applying an erasing solution as described in JP-B No. 2-13293 to the unnecessary image portions and washing with water after a prescribed duration.
• planographic printing plate produced in such a manner is coated with a desensitizing gum if necessary and supplied to printing steps.
• baking treatment is optionally carried out.
• the baking treatment of the planographic printing plate it is preferable to treat, prior to the baking treatment, the planographic printing plate with surface conditioning solutions described in JP-B Nos. 61-2518 and 55-28062 and JP-A Nos. 62-31859 and 61-159655 .
• Examples of a method for effecting such a pre-baking treatment include a method of applying the surface conditioning solutions to the planographic printing plate by sponge or degreased cotton doped with the solutions, a method of immersing the printing plate in a vat filled with the surface conditioning solutions, a method of applying the surface conditioning solutions using automatic coaters. In a case where after application the amount of solution applied is made uniform with a squeegee or a squeegee roller, a better result can be obtained.
• the amount of surface-adjusting solution applied is suitably from 0.03 to 0.8 g/m 2 (dry mass).
• the planographic printing plate onto which the surface-adjusting solution is applied can be dried, and then the plate is heated to a high temperature by means of a baking processor (for example, a baking processor (BP-1300) sold by Fuji Photo Film Co., Ltd.) or the like.
• a baking processor for example, a baking processor (BP-1300) sold by Fuji Photo Film Co., Ltd.
• the heating temperature and the heating time which depend on the kind of components forming the image, are preferably from 180 to 300°C and from 1 to 20 minutes, respectively.
• a planographic printing plate subjected to a baking treatment can be subjected to treatments which have been conventionally conducted, such as a water-washing treatment and gum coating.
• treatments which have been conventionally conducted such as a water-washing treatment and gum coating.
• the so-called desensitizing treatment for example, gum coating
• the so-called desensitizing treatment can be omitted.
• planographic printing plate precursor of the present invention is processed into a planographic printing plate. This planographic printing plate is then placed on an offset printing machine and the like, and used for printing large quantities of sheets.
• the planographic printing plate precursor of the present invention has the advantages of excellent chemical resistance and printing endurance in the image area, wide image development latitude, and excellent image reproducibility.
• Polymer 2 was synthesized in the same way as the synthesis of the high molecular compound containing a polymerizable monomer in Synthesis example 1, except for the use of 15.5 g of methacrylol oxyethyl isocyanate, 12.0 g of 4-aminophenol, and 140 g of dioxane solvent, such that 25.0 g of 2-(N'-(4-hydroxyphenyl)ureido) ethyl methacrylate having the following constituent unit was obtained.
• Mw weight-average molecular weight
• Mw weight-average molecular weight
• n 1 to 15
• the Ph within the parenthesis is a benzene ring.
• the plate was etched using a liquid with a caustic soda concentration of 30 g/l and an aluminum ion concentration of 10 g/l at 40°C for 10 seconds, and washed with flowing water. Then, the plate was subjected to desmutting treatment in sulfuric acid solution of 15 mass % concentration at a temperature of 30°C, and was rinsed in water. Furthermore, the plate was anodized in sulfuric acid aqueous solution of 10 mass % concentration at the temperature of 20°C under the condition of a direct current density of 6A/dm 2 so that the amount of anodic oxide film was 2.5 g/m 2 , and then rinsed in water and dried. After that, the plate was treated with a sodium silicate aqueous solution of 1.0 mass % concentration at 30°C for 10 seconds to manufacture a hydrophilic substrate (a).
• the average center line roughness of this substrate (a), (Ra), was measured using a needle of 2 ⁇ m diameter, and the result was 0.43 ⁇ m.
• the substrate (a) thus obtained was coated with the following primer coat liquid and then dried at 80°C for 30 seconds to prepare a primer layer.
• the dried coated amount of the primer layer was 17 mg/m 2 .
• the substrate having the primer layer obtained in the above-mentioned manner was coated with a coating liquid for a positive recording layer and dried at 150°C for 1 minute in an oven to give a positive photosensitive planographic printing plate having a positive recording layer of 1.5 g/m 2 in dried coating amount.
• polymers 1 to 6 having a urea bond in a side chain in the present invention which are described in the following Table 1, was described in the above-mentioned synthesis examples, and (C) a specific amino compound is indicated by the exemplary compounds prefixed with "C" described above.
• a test pattern was drawn as an image on the obtained photosensitive planographic printing plate precursor using a Trendsetter® manufactured by Creo Co., Ltd. at a beam intensity of 9 W and a drum rotation speed of 150 rpm.
• planographic printing plate precursor was developed using a PS processor 900H® (trade name, manufactured by Fuji Photo Film Co., Ltd.), into which an alkaline developer having the following composition had been fed, while the temperature of the developer was kept at 30°C with a developing time of 20 seconds.
• the image in the obtained planographic printing plate was printed using a Lithron printing machine manufactured by Komori Corporation using DIC-GEOS (N)® (trade name) black ink manufactured by Dainippon Ink And Chemicals, Inc., and the printing durability was evaluated by the number of printed sheets until the point in time when it was visually recognized that the density of the solid image began to become low. The result was shown in the following Table 2.
• Exposure and development were performed on the obtained photosensitive planographic printing plate precursor in the same method as the above-mentioned evaluation method for printing durability and chemical resistance.
• the conductivity of the developer was raised by a constant value by suitably adding a potassium hydroxide aqueous solution of 3 mass % to the developer, development operations were carried out using the developer of each conductivity value.
• the conductivity of the developer was lowered by a constant value by blowing carbon dioxide gas into the alkaline developer and several developers having low conductivity (that is, developers with low activity) were prepared, development operations were carried out using the developer of each conductivity value.
• planographic printing plate precursors in Examples 1 to 12 were good also in usual printing durability and development latitude compared with Comparative Examples 1 to 6.

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• 2005
  • 2005-03-22 JP JP2005082770A patent/JP4404792B2/ja not_active Expired - Fee Related
• 2006
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