Lithographic printing plates and instructions for use

Abstract

The lithographic printing plate precursor has an aluminum-containing substrate prepared using two anodizing processes to provide an inner aluminum oxide layer with an average dry thickness of 300 to 3,000 nm and a large number of inner micropores with an average inner pore diameter of 100 nm or less. The outer aluminum oxide layer has a large number of outer micropores with an average outer pore diameter of 15 to 30 nm and a dry thickness of 30 to 650 nm. The hydrophilic layer has a thickness of 0.0002 to 0.1 g / m². 2 and disposed on the outer aluminum oxide layer by the formula: (1) an ethylenically unsaturated polymerizable group; a compound having an -OM group (wherein M represents hydrogen, sodium, potassium, or an aluminum atom) directly bonded to a phosphorus atom; and (2) one or more hydrophilic polymers having (a) a repeating unit comprising an amide group, and (b) a repeating unit having an -OM' group (wherein M' represents hydrogen, sodium, potassium, or an aluminum atom) directly bonded to a phosphorus atom.

Description

[Technical Field]

[0001] The present invention relates to a lithographic printing plate master comprising an aluminum-containing substrate prepared using at least two distinct anodizing processes to provide different aluminum oxide layers having different structural properties. The aluminum-containing substrate also has a unique hydrophilic layer disposed on the aluminum oxide layer, which comprises at least one unique hydrophilic copolymer as defined below; as well as a compound having an -OM group (defined below) directly bonded to a phosphorus atom and at least one ethylenically unsaturated polymerizable group. The present invention also relates to a method for image-forming and processing such a lithographic printing plate master to obtain a lithographic printing plate. The present invention further relates to a method for producing such a plate of the present invention. [Background technology]

[0002] In lithographic printing, ink-receiving areas, known as image areas, are created on the hydrophilic surface of the substrate. When the printing plate surface is moistened with water and lithographic ink is applied, the hydrophilic areas retain the water and repel the lithographic ink, while the ink-receiving image areas accept the lithographic ink and repel the water. The lithographic ink is transferred from the lithographic plate to the surface of the material on which the image is to be reproduced, possibly using a blanket roller.

[0003] Image-forming elements or lithographic printing plates used to prepare lithographic printing plates typically include one or more radiative image-forming layers placed on the outermost hydrophilic surface of a substrate. After image formation, either the exposed (image-forming) or unexposed (non-image-forming) areas of one or more radiative layers can be removed using a suitable developer to expose the outermost hydrophilic surface of the substrate. If the exposed areas are removable, the lithographic printing plate is considered a positive type. Conversely, if the unexposed areas are removable, the lithographic printing plate is considered a negative type.

[0004] Direct digital (laser) thermal imaging of lithographic printing plates has become increasingly important in the printing industry over the past 30 years due to its stability against ambient light. Such plates are designed to be sensitive to imaging near-infrared radiation of at least 750 nm. However, other very useful lithographic printing plates are still designed to be sensitive to digital imaging by UV or "violet" radiation of at least 250 nm.

[0005] A negative-type lithographic printing plate master useful for preparing lithographic printing plates typically includes a negative-type radiosensitive image-forming layer disposed on the hydrophilic surface of a substrate. A radiosensitive photopolymerizable composition used for a negative-type lithographic printing plate master typically includes a free-radical polymerizable component, one or more radiation absorbers, an initiator composition, and optionally one or more polymer binders different from other described components. Such masters, having polymer intermediate layers on the substrate and beneath the image-forming layer(s), can be developed after image formation using conventional developers in an off-press developing apparatus as described in U.S. Patent Application Publication No. 2012 / 0070779 (Miyamoto et al.).

[0006] For the past several decades, the industry has emphasized simplifying the lithographic plate-making process, including eliminating the pre-development heating step and performing on-press development (DOP) using lithographic inks, dampening solution, or both to remove unwanted (unexposed) image-forming layer material from the lithographic plate master. Such negative-type lithographic plates should be designed by balancing many features within their elemental structure to achieve optimal press life, on-press developability, and scratch resistance. Optimizing all of these features simultaneously has not been an easy task, as chemical composition or structural features that may provide optimal levels in one or two properties may lead to a loss of another.

[0007] Regardless of the type of lithographic printing plate, lithographic printing is generally carried out using metal-containing substrates, which include aluminum alloys of various metal compositions containing up to 10% by weight in total of aluminum or one or more of other metals known in the art for this purpose, for example. The raw aluminum-containing material can be clarified in a “pre-etching” process using a base or surfactant solution to remove oil, grease, and other contaminants from the surface of the raw aluminum-containing material. The clarified surface is then generally roughened by electrochemical or mechanical granulation, followed by a “post-etching” treatment to remove contaminants ("smut") formed during the granulation process. Further industrial details of the preparation of useful substrates for lithographic printing plates can be found in U.S. Patent Application Publication No. 2014 / 0047993 (Hauck et al.).

[0008] Next, after further rinsing, once one or more image-forming layers have formed thereon, the treated surface of the aluminum-containing substrate is anodized once or multiple times to obtain an outermost hydrophilic aluminum oxide coating for the wear resistance and other necessary properties of the resulting lithographic printing plate.

[0009] For example, as described in U.S. Patent No. 4,566,952 (Sprintschnik et al.) and No. 8,783,179 (Kurokawa et al.), U.S. Patent Publication No. 2011 / 0265673 (Tagawa et al.), No. 2012 / 0192742 (Kurokawa et al.), No. 2014 / 0326151 (Namba et al.), and No. 2015 / 0135979 (Tagawa et al.), and European Patent No. 2353,882 (Tagawa et al.), one or more anodic oxidation processes are used in several known methods for producing a master substrate.

[0010] In these known methods for preparing master plates, one or more anodic (aluminum oxide) layers of a specific structure are manufactured, and thus, sulfuric acid, phosphoric acid, or both sulfuric acid and phosphoric acid have been used as electrolytes in combination with various process parameters to achieve specific properties in the resulting master plate. However, lithographic master plates prepared according to these known methods have been found to still be insufficient in one or more properties such as scratch resistance, on-press developability, press life, and toning restart (RST).

[0011] Due to the harmful effects of processing chemicals and waste generated during the lithographic plate-making process, lithographic plates that can be developed on-press after image formation using lithographic inks and / or dampening solutions have become significantly more desirable in the industry. Early commercialized lithographic plates of this type were typically limited to printing applications requiring fewer than 100,000 prints. Such limitations resulted from the technical difficulty of achieving both rapid on-press development and good image durability.

[0012] Advances in the art concerning on-press developable lithographic printing plates include the uniquely anodized substrates described in U.S. Patent No. 1,0828884 (Merka et al.) and U.S. Patent No. 1,0363734 (Merka et al.), both assigned to the assignee of the present invention.

[0013] More recently, aluminum-containing substrates having multilayer anodized oxide structures, as described in these publications, have been developed. Such substrates for on-press developable lithographic printing plates, having an on-press developable image-forming layer, exhibit image durability (good press life) while maintaining rapid on-press developability. In such on-press developable lithographic printing plates, a hydrophilic undercoat layer can be placed between the on-press developable image-forming layer and the multilayer aluminum anodized oxide structure.

[0014] A typical polymer included in this hydrophilic undercoat layer is partially neutralized polyacrylic acid. However, lithographic plates made from such on-press developable lithographic plates have been shown to occasionally experience a problem known as insufficient toning restart (specified herein as RST), in which the background becomes ink-sensitive and requires many prints to become clear when lithographic printing is resumed after a printing interruption or stoppage.

[0015] Therefore, there remains a need to provide lithographic printing plates that can be easily resumed after a printing interruption, with the above-mentioned color resumption problem reduced or eliminated. It is particularly desirable that such lithographic printing plates be derived from on-press developable negative lithographic printing plates without sacrificing press life and on-press developability. [Prior art documents] [Patent Documents]

[0016] [Patent Document 1] U.S. Patent Application Publication No. 2012 / 0070779 Specification [Patent Document 2] U.S. Patent Application Publication No. 2014 / 0047993 [Patent Document 3] U.S. Patent No. 4566952 [Patent Document 4] U.S. Patent No. 8783179 [Patent Document 5] U.S. Patent Application Publication No. 2011 / 0265673 [Patent Document 6] U.S. Patent Application Publication No. 2012 / 0192742 [Patent Document 7] U.S. Patent Application Publication No. 2014 / 0326151 [Patent Document 8] U.S. Patent Application Publication No. 2015 / 0135979 [Patent Document 9] European Patent No. 2353882 [Patent Document 10] U.S. Patent No. 10828884 [Patent Document 11] U.S. Patent No. 10363734 [Overview of the project]

[0017] The present invention comprises a substrate having a surface, A radioactive image-forming layer that can be developed on press and placed on the surface of a substrate A lithographic printing plate original, The circuit board is An aluminum-containing plate having a granulated and etched surface; An inner aluminum oxide layer disposed on a granulated and etched surface, wherein the inner aluminum oxide layer has an average dry thickness (T) of at least 300 nm and 3000 nm or less. i ) has an average inner pore diameter (D) of 100 nm or less. i An inner aluminum oxide layer containing numerous inner micropores having; An outer aluminum oxide layer disposed on an inner aluminum oxide layer, wherein the outer aluminum oxide layer has an average outer micropore diameter (D) of at least 15 nm and 30 nm or less. o It includes numerous outer micropores having ) and an average dry thickness (T) of at least 30 nm and 650 nm or less. o ) having an outer aluminum oxide layer; At least 0.0002 g / m³ 2 and 0.1 g / m 2 A hydrophilic layer disposed on the outer aluminum oxide layer with the following dry coverage, wherein the hydrophilic layer is: (1) Compounds having one or more ethylenically unsaturated polymerizable groups, one or more -OM groups in which at least one of the groups is directly bonded to a phosphorus atom, and a molecular weight of less than 2000 daltons / mol, where M represents a hydrogen, sodium, potassium, or aluminum atom; and (2) Each of them is a repeating unit containing at least (a) an amide group and (b) a repeating unit containing an -OM' group directly bonded to a phosphorus atom, where M' represents a hydrogen, sodium, potassium, or aluminum atom, and contains one or more hydrophilic polymers containing repeating units, and a hydrophilic layer provides a lithographic printing plate precursor containing

[0018] Furthermore, the present invention is a method for providing a lithographic printing plate, comprising the step of imagewise exposing a lithographic printing plate precursor according to any embodiment of the present invention to image-forming radiation to form an imagewise exposed image-forming layer having exposed and unexposed regions; and the step of removing the unexposed regions from the imagewise exposed image-forming layer on-press to form a lithographic printing plate.

[0019] Furthermore, the present invention is a method for preparing a lithographic printing plate precursor, comprising, in order, providing an aluminum-containing plate having an electrochemically or mechanically granulated and etched surface; subjecting the aluminum-containing plate to a first anodic oxidation process to form an outer aluminum oxide layer on the electrochemically or mechanically granulated and etched surface, the outer aluminum oxide layer containing a plurality of outer micropores having an average outer micropore diameter (D o ) of at least 15 nm and 30 nm or less, and having an average dry thickness (T o ) of at least 30 nm and 650 nm or less; rinsing the outer aluminum oxide layer; subjecting the aluminum-containing plate to a second anodic oxidation process to form an inner aluminum oxide layer under the outer aluminum oxide layer, the inner aluminum oxide layer having an average dry thickness (T i ) of at least 300 nm and 3000 nm or less; and containing a plurality of inner micropores having an average inner micropore diameter (D i ) of 100 nm or less; A step of rinsing the outer aluminum oxide layer and the inner aluminum oxide layer; A step of forming an on-press developable radiosensitive image-forming layer on an outer aluminum oxide layer; After rinsing the outer aluminum oxide layer and the inner aluminum oxide layer, a step is to provide a hydrophilic layer on the outer aluminum oxide layer before forming an on-press developable radiosensitive image-forming layer on the outer aluminum oxide layer, wherein the hydrophilic layer is (1) Compounds having one or more ethylenically unsaturated polymerizable groups, one or more -OM groups in which at least one of the groups is directly bonded to a phosphorus atom, and a molecular weight of less than 2000 daltons / mol, where M represents a hydrogen, sodium, potassium, or aluminum atom; and (2) comprising one or more hydrophilic polymers, each comprising a repeating unit comprising at least (a) an amide unit and (b) a repeating unit comprising an -OM' group directly bonded to a phosphorus atom, where M' represents a hydrogen, sodium, potassium, or aluminum atom, The hydrophilic layer has a density of at least 0.0002 g / m 2 and 0.1 g / m 2 The following processes are performed, with the following dry coverage degrees, on the outer aluminum oxide layer: This provides a method that includes [something].

[0020] The above-mentioned toning restart (RST) problem has been successfully addressed in accordance with the present invention by providing an inherent hydrophilic layer (sometimes known as a "primer" layer) on the multilayer aluminum anodized structure to form an on-press developable lithographic printing plate master of the present invention. Such a hydrophilic layer comprises one or more hydrophilic polymers comprising both (2) repeating units having at least (a) an amide group and (b) repeating units having an -OM' group (wherein M' is a hydrogen, sodium, potassium, or aluminum atom) directly bonded to a phosphorus atom. Furthermore, this hydrophilic layer comprises (1) one or more ethylenically unsaturated polymerizable groups, one or more -OM groups (wherein M is a hydrogen, sodium, potassium, or aluminum atom) with at least one of them directly bonded to a phosphorus atom, and a compound having a molecular weight of less than 2000 daltons / mol. These two components of (1) the compound and (2) one or more hydrophilic polymers comprising at least one hydrophilic copolymer should be used together. Specific details of these essential components used to produce the hydrophilic layer are provided below. Significant improvements in RST are achieved while maintaining acceptable scratch resistance, on-press developability, and long press life. [Modes for carrying out the invention]

[0021] The following discussion relates to various embodiments of the invention, and while some embodiments may be preferable for specific uses, the disclosed embodiments should not be construed as limiting the scope of the invention as claimed below. Furthermore, those skilled in the art will understand that the following disclosures have broader applications than those explicitly described in the discussion of any particular embodiment.

[0022] definition Where used herein to define the various components of the radiosensitive imaging layer formulation (and the resulting dried layer), the anodic oxidation solution, the hydrophilic layer formulation (and the resulting dried layer), and other materials used in the practice of the present invention, unless otherwise indicated, the singular forms "a," "an," and "the" are intended to include one or more components (i.e., include multiple references).

[0023] Each term not expressly defined in this application should be understood to have a meaning generally accepted by those skilled in the art. Where interpretation of a term would render it meaningless or essentially meaningless in its context, the term should be interpreted as having its standard dictionary meaning.

[0024] The use of numerical values ​​within the various ranges specified herein is considered an approximation unless explicitly indicated otherwise, as if the word “approximately” preceded both the minimum and maximum values ​​within the stated range. Thus, slight variations above and below the stated range may be useful in achieving substantially the same results as values ​​within the range. Furthermore, these range disclosures are intended as continuous ranges encompassing all values ​​between the minimum and maximum values, as well as the endpoint of the range.

[0025] Unless otherwise indicated by the context, the terms “negative radiosensitive lithographic printing plate,” “plate,” “radiosensitive plate,” and “lithographic printing plate” as used herein are intended to refer to certain embodiments of the present invention.

[0026] The term “support” is used herein to refer to aluminum-containing or other metal-containing materials (sheets, webs, strips, sheets, foils, or other forms) that can be processed to prepare the “substrate” as will be described in more detail below.

[0027] Average outer pore size (D) in nanometers (nm) oThe outer micropore diameter (D) of the lithographic printing plate can be determined from a top-view SEM image taken from the substrate surface at a magnification of at least 50,000x before the application of any hydrophilic layer and one or more radiosensitive imaging layers. The outer micropore diameter (D) of the lithographic printing plate can be determined by stripping the organic layer with a suitable solvent and, optionally, removing the outer portion of the outer aluminum oxide layer about 20 nm to 80 nm thick using a suitable technique such as argon ion beam sputtering before taking a top-view SEM image. o It is also possible to determine the average value. The average value can be determined by examining more than 200 outer micropores.

[0028] Average inner micropore diameter (D i The ) can be determined from a cross-sectional SEM image at a magnification of at least 50,000x. The cross-section can be generated by bending the lithographic printing plate or its substrate after the image-forming layer and any hydrophilic layer have been removed. During bending, cracks are formed in the aluminum oxide layer, and new surfaces are formed, usually at the weakest locations, which are typically located at the thinnest walls between adjacent inner micropores. Thus, the new surfaces of the cracks provide cross-sectional views of many micropores. In the present invention, the accurate average inner micropore diameter (D) can be determined as long as at least 90% of the exposed micropore cross-sections have a width of less than 15 nm. i There is no need to decide on that.

[0029] Average dry thickness (T) of the outer anodized layer in nanometers (nm) units o ) and the average dry thickness of the inner anodized layer (T i These can each be determined from cross-sectional SEM images at a magnification of at least 50,000 times. The cross-section of the aluminum oxide layer can be revealed through cracks formed by bending the lithographic printing plate or its substrate. The cross-section of the aluminum oxide layer can also be revealed by cutting a slot through the aluminum oxide layer with a focused ion beam (FIB), a technique well known in the art.

[0030] Micropore / μm 2Outer anodic oxide layer pore density (C) o This can be determined from a top-surface SEM image at a magnification of at least 50,000 times by counting the number of micropores in a predetermined area of ​​a square having an area of, for example, 500 nm × 500 nm.

[0031] Porosity of the outer aluminum oxide layer (P o ) can be limited by each of the following formulas: 0.3 ≤ P o ≤ 0.8 or 0.3 ≤ P o ≤0.6 (In the formula, P o is 3.14(C o )(D o 2 (defined as ) / 4000000).

[0032] As used herein, the term “radiation absorber” means a compound or material that absorbs electromagnetic radiation in a defined region, typically a compound or material, or a mixture thereof, that has maximum absorption in the region of at least 250 nm (UV and violet) and up to 1400 nm.

[0033] As used herein, the term “infrared region” refers to radiation having wavelengths of at least 750 nm or greater. In most examples, the term “infrared” is used to refer to the “near-infrared” region of the electromagnetic spectrum, which is defined herein as at least 750 nm and 1400 nm or less. Similarly, infrared radiation absorbers provide sensitivity in the infrared region.

[0034] To clarify the definitions of polymer-related terms, one should refer to the "Glossary of Basic Terms in Polymer Science" published by the International Union of Pure and Applied Chemistry ("IUPAC"), Pure Appl. Chem. 68, 2287-2311 (1996). However, the definitions explicitly set forth herein should be considered to take precedence.

[0035] As used herein, the term “polymer” is used to describe compounds with relatively large molecular weights that are formed by bonding many small reactive monomers. As the polymer chain grows, it folds randomly to form a coiled structure. Depending on the choice of solvent, the polymer may become insoluble as the chain length increases, resulting in polymer particles dispersed in a solvent medium. These particle dispersions are highly stable and can be useful in the radiosensitive imaging layers described for use in the present invention. In the present invention, unless otherwise specified, the term “polymer” refers to non-crosslinked materials. Thus, non-crosslinked polymer particles can dissolve in certain organic solvents with good solvation properties, whereas crosslinked polymer particles do not dissolve in organic solvents, although they may swell in organic solvents because the polymer chains are linked by strong covalent bonds.

[0036] The term "copolymer" refers to a polymer composed of two or more different repeating or iterative units arranged along a copolymer backbone.

[0037] The term "polymer backbone" refers to a chain of atoms in a polymer to which one or more pendant groups can be attached. An example of such a polymer backbone is the "all-carbon" backbone obtained from the polymerization of one or more ethylenically unsaturated polymerizable monomers. When polymers are formed using condensation polymerization with appropriate reactants, some polymer backbones can contain both carbon atoms and heteroatoms.

[0038] The repeating units of polymer binders described herein are derived from corresponding ethylenically unsaturated polymerizable monomers (also referred to herein as “monomers”) commonly used in polymerization processes, which can be obtained from various commercial sources or prepared using known chemical synthesis methods. Repeating units derived from the same ethylenically unsaturated polymerizable monomer are, by definition, identical in composition and molecular weight unless otherwise stated herein.

[0039] As used herein, the term "ethylenically unsaturated polymerizable monomer" refers to a compound containing one or more ethylenically unsaturated (-C=C-) bonds that can be polymerized using free radical or acid-catalyzed polymerization reactions and conditions. This term is not intended to refer to chemical compounds having only unsaturated -C=C- bonds that cannot be polymerized under these conditions.

[0040] Unless otherwise specified, the term "weight %" refers to the amount of an ingredient or material based on the total solids content of a composition, formulation, or dry layer. Unless otherwise specified, the percentage may be the same for the total solids content of either the dry layer or the formulation or composition used to form that dry layer.

[0041] As used herein, the terms “layer” or “coating” may refer to a single arrangement or applied layer, or a combination of several consecutive arrangements or applied layers. Where a layer is considered radiative and negative, it is sensitive to appropriate radiation (e.g., infrared radiation) and negative in the formation of a lithographic printing plate.

[0042] use The lithographic printing plates of the present invention are useful, for example, for forming lithographic printing plates using lithographic inks and dampening solutions. These plates are prepared with the structure and components described below. Furthermore, the lithographic printing plates of the present invention are designed to be negative-type and on-press developable using the appropriate materials and manufacturing procedures described below to provide a negative-type radiosensitive formulation and an image-forming layer.

[0043] Furthermore, the master plates of the present invention are designed to be on-press developable, so that the development of the image-forming master plate can be achieved on press using, for example, dampening solution, lithographic ink, or both dampening solution and lithographic ink. However, if the user desires, it is still possible to develop such master plates off-press using a suitable developer.

[0044] The present invention is also useful for manufacturing such lithographic printing plates that can then be sold to customers for use in image formation and printing.

[0045] The substrate of the present invention The substrates useful in this invention are designed to have important features and properties in order to achieve the above advantages.

[0046] A general description of the manufacture of substrates useful for lithographic printing plates can be found in U.S. Patent Application Publication No. 2014 / 0047993 (above).

[0047] Generally, lithographic printing substrates can be derived from aluminum or other metallic materials, for example, aluminum alloys containing one or more elements, but not limited to, up to 10% by weight, including manganese, silicon, iron, titanium, copper, magnesium, chromium, zinc, bismuth, nickel, and zirconium. The aluminum or aluminum alloy-containing support (or “plate” or “raw material”) can have any further treatable form, including sheets, continuous webs, and coiled strips, as long as it has at least one (substantially flat) surface that can be treated as described below to form a hydrophilic surface on the substrate of the present invention. It is also possible to use polymer films or paper on which layers of pure aluminum or aluminum alloy-containing material have been deposited or laminated.

[0048] The resulting substrate must be thick enough to mechanically withstand the conditions of a modern printing press, but thin enough to be mounted (or wrapped around) the printing cylinder of such a machine. Therefore, the substrate should also possess the appropriate tensile strength, elasticity, crystallinity, and conductivity required for lithographic printing. These properties can be achieved by standard methods such as heat treatment or cold and hot rolling, which are typical for the manufacture of continuous lithographic support strips, webs, or coils. The dry thickness of the resulting substrate of the present invention is generally at least 100 μm and no more than 600 μm.

[0049] The aluminum-containing supports described can be processed using a typical lithographic printing plate manufacturing process that includes pre-etching, rinsing, roughening, rinsing, post-etching, and final rinsing steps, in combination with the first and second anodizing processes described in more detail below.

[0050] A raw material aluminum-containing support is typically subjected to a pre-etching process to remove oil, grease, and metal and other contaminants from or near the surface of the support. As is known in the art, this pre-etching process can be carried out using sodium hydroxide or other alkaline aqueous solutions, or even certain organic solvents, at known concentrations, times, and temperatures. If desired, a separate or additional degreasing process can be performed using an aqueous surfactant solution. Those skilled in the art will be able to find the optimal pre-etching conditions (e.g., optimal solution concentration, residence time, and temperature) through routine experimentation.

[0051] Typically, after a pre-etching process, the etched support is “roughened” by an appropriate method, such as using a known electrochemical or mechanical roughening (or granulation) process. In electrochemical granulation, the etched support can be treated with alternating current in a hydrochloric acid solution of 5–20 g / liter. For this purpose, a solution of nitric acid (e.g., up to 2.5 wt%) or sulfuric acid or a mixture thereof can also be used. Such electrochemical granulation solutions may also contain additives such as corrosion inhibitors and stabilizers, including, but not limited to, metal nitrates, metal chlorides, monoamines, diamines, aldehydes, phosphoric acid, chromic acid, boric acid, lactic acid, acetic acid, and oxalic acid. For example, electrochemical granulation can be carried out using the process described in U.S. Patent Application Publication No. 2008 / 0003411 (Hunter et al.). Since such processes are well known in the art, those skilled in the art will be able to determine the optimal conditions for electrochemical or mechanical granulation by routine experimentation. The mechanical granulation process can be carried out, for example, using a suitable brush alone or in combination with a slurry of abrasive materials such as silica particles or alumina particles. Alternatively, a combination of the mechanical granulation process and the electrochemical granulation process can be used.

[0052] During roughening or granulation, smut may form on the surface of the support, which can be removed by treatment with a highly acidic or highly alkaline solution, for example, at a concentration of 0.01 to 5.0 g / m². 2The smut can be removed in a post-etching process that removes the surface of the support. For example, post-etching can be performed using a solution of sodium hydroxide, trisodium phosphate, or sulfuric acid. The amount of post-etching can be controlled by setting the residence time, concentration, and temperature of the etching solution. The appropriate amount of post-etching also depends on the amount of roughening and the amount of smut formed in that process. The post-etching treatment should be sufficient to remove the smut, but should not destroy too much of the surface structure formed in the roughening process. Therefore, there are many combinations of parameters that a person skilled in the art can consider during routine experiments to find the optimal post-etching conditions.

[0053] The above process results in an electrochemically or mechanically granulated (roughened) and etched surface on the aluminum-containing support.

[0054] The following steps, carried out according to the present invention, include at least a first anodizing process and a second anodizing process, both of which are essential to the present invention, forming an outer aluminum oxide layer and an inner aluminum oxide layer, respectively. The method of the present invention does not require additional anodizing processes (i.e., a third or more anodizing processes), however, one or more additional anodizing processes are possible and therefore optional. However, in many embodiments, the first and second anodizing processes described herein are the only anodizing processes.

[0055] The first and second anodizing processes generally use 4 g / m². 2 This can be done using a sulfuric acid or phosphoric acid (electrolyte) solution for a suitable time of at least 1 second and no more than 250 seconds at at least 20°C and no more than 70°C, sufficient to provide the following total dry aluminum oxide coverage (sum of both the outer and inner aluminum oxide layers). The conditions are described below for both the first and second anodizing processes.

[0056] A suitable aluminum-containing plate having an electrochemically or mechanically granulated and etched surface is subjected to a first anodizing process to form an outer aluminum oxide layer on the electrochemically or mechanically granulated and etched surface. For example, the first anodizing process can be carried out using an electrolyte composition containing at least 50 g / liter and 350 g / liter or less of phosphoric acid, or at least 150 g / liter and 300 g / liter or less of sulfuric acid, and an appropriate amount of aluminum, for example, 5 g / liter. The amounts of these solutions can be optimized with respect to the type of acid, acid concentration, aluminum concentration, residence time, and temperature to achieve the desired outer aluminum oxide layer properties described herein. Typical details of such a first anodizing process are illustrated in the examples described below. It is particularly useful to carry out the first anodizing process using phosphoric acid.

[0057] The resulting outer aluminum oxide layer has an average outer pore size (D) of at least 15 nm and 30 nm or less. o It contains numerous outer micropores having ). Furthermore, the average dry thickness (T) of the outer aluminum oxide layer. o The pore density (C) of the outer anodized layer may be at least 30 nm and 650 nm or less, or more likely at least 130 nm or at least 150 nm and 400 nm or less. o Generally, it has at least 500 micropores / μm 2 and 3000 micropores / μm 2 The following are possible:

[0058] Furthermore, the average outer pore size (D) of the outer aluminum oxide layer is measured in nanometers. o ) and micropores / μm 2 Unit pore density (C o ) can be further limited or related according to each of the following formulas: 0.3 ≤ P o ≤ 0.8 or 0.3 ≤ P o ≤0.6 (In the formula, porosity P o (as defined above).

[0059] After the first anodizing process has been carried out for the desired time, the formed outer aluminum oxide layer can be rinsed with a suitable solution such as water at an appropriate temperature and time, if desired, to remove residual acid and aluminum, and the first anodizing process can be stopped.

[0060] Next, a second anodic oxidation process is carried out using a suitable electrolyte composition containing at least 100 g / liter and no more than 350 g / liter of sulfuric acid, or at least 50 g / liter and no more than 350 g / liter of phosphoric acid, and an appropriate amount of aluminum, for example, 5 g / liter, to form an inner aluminum oxide layer beneath the outer aluminum oxide layer. The amounts of these solutions can be optimized with respect to acid concentration, aluminum concentration, residence time, and temperature to achieve the desired inner aluminum oxide layer properties described herein. Details of such a second anodic oxidation process are illustrated in the examples described below.

[0061] The resulting inner aluminum oxide layer, placed on the granulated and etched surface of the substrate, has an average inner micropore size (D) of 100 nm or less. i It contains numerous internal micropores having an average internal micropore diameter (D i ) is 15 nm or less. In such embodiments, D o D i The ratio to can be greater than 1.1:1, or even greater than 1.5:1, and typically greater than 2:1. In other embodiments, the average inner pore size (D i ) is greater than 30 nm, and the average outer pore size (D o ) is greater than. In these latter embodiments, D i D oThe ratio to can be greater than 1.1:1, or even greater than 1.5:1, and typically greater than 2:1. Furthermore, the average dry thickness (T) of the inner aluminum oxide layer i ) may be at least 300 nm or at least 650 nm, and 1500 nm or less, or 3000 nm or less.

[0062] In some embodiments, the outer aluminum oxide layer is directly placed on the inner aluminum oxide layer, and the average micropore size (D) of the inner aluminum oxide layer is such that i The outer aluminum oxide layer has a minimum of 20 nm of fine pore size (D o It is greater than ).

[0063] After the second anodizing process has been carried out for the desired time, both the formed outer aluminum oxide layer and the inner aluminum oxide layer can be rinsed with a suitable solution, such as water, at an appropriate temperature and time, if desired, to remove residual acid and aluminum, and the second anodizing process can be stopped.

[0064] In some embodiments of the present invention, an aluminum-containing support is subjected to an additional anodic oxidation process using a suitable acid or a mixture thereof for a suitable time and temperature to obtain an "intermediate aluminum oxide layer". This additional anodic oxidation process is performed after the first anodic oxidation process and before the second anodic oxidation process. Thus, the intermediate aluminum oxide layer is generally formed between the outer aluminum oxide layer and the inner aluminum oxide layer that is formed later. In such embodiments, the formed intermediate aluminum oxide layer has an average dry thickness (T) of at least 60 nm and 300 nm or less. m ) can have an average intermediate micropore diameter (D) of at least 20 nm and 60 nm or less. m It may contain a number of intermediate micropores having )

[0065] In such embodiments, D m However, D i Larger than D oLarger than T o It may be less than 150 nm.

[0066] After the formation of this intermediate aluminum oxide layer, the outer aluminum oxide layer and the intermediate aluminum oxide layer can be rinsed, as described above only for the outer aluminum oxide layer, before the inner aluminum oxide layer is formed as described above.

[0067] According to the present invention, it is essential to provide a hydrophilic layer disposed on the outer aluminum oxide layer. The hydrophilic layer can be provided from a hydrophilic layer formulation comprising one or more hydrophilic polymers, generally at least 0.0002 g / m². 2 and 0.1 g / m 2 The following or at least 0.005 g / m² 2 and 0.08 g / m 2 The following amounts of hydrophilic layer are applied or placed on the outer aluminum oxide layer to provide dry coverage. Generally, since the hydrophilic layer is placed directly on the outer aluminum oxide layer, there is no intermediate layer. Since the outer aluminum oxide layer contains micropores, a portion of the hydrophilic layer can be present inside these outer micropores and in the micropores beneath the outer aluminum oxide layer.

[0068] The hydrophilic layer used in carrying out the present invention comprises two essential components, namely, a compound defined as follows, having one or more ethylenically unsaturated polymerizable groups, one or more -OM groups (wherein M represents a hydrogen, sodium, potassium, or aluminum atom) with at least one of them directly bonded to a phosphorus atom, and a molecular weight of less than 2000 daltons / mol or less than 1500 daltons / mol; and (2) one or more hydrophilic polymers, each comprising a repeating unit comprising at least (a) an amide group and (b) an -OM' group (wherein M' is a hydrogen, sodium, potassium, or aluminum ion) directly bonded to a phosphorus atom. M and M' may be the same or different atoms in a given hydrophilic layer formulation.

[0069] The essential (1) compound having one or more ethylenically unsaturated polymerizable groups is more specifically defined as follows: At least one of such ethylenically unsaturated polymerizable groups is bonded to a phosphorus atom to which the -OM group is directly bonded. Thus, at least one ethylenically unsaturated group can be bonded to that phosphorus atom directly or via a spacer group as described below.

[0070] Such one or more ethylenically unsaturated polymerizable groups generally contain carbon-carbon double bonds that can be polymerized in the presence of free radicals or cationic initiators, as is known to those skilled in polymer chemistry. More specifically, such groups can be represented by the following formula: -C(R')=CH2 (wherein R' represents a hydrogen atom, or, but not limited to, an unsubstituted linear or branched alkyl group having 1 to 4 carbon atoms, including unsubstituted methyl, ethyl, n-propyl, isobutyl, n-butyl, and t-butyl groups). In most embodiments, R is a hydrogen atom or an unsubstituted methyl group.

[0071] (1) The compound should also contain one or more (typically only one) -OM groups (wherein M represents a hydrogen, sodium, potassium, or aluminum atom). At least one of the one or more -OM groups should be directly bonded to a phosphorus atom in the compound molecule, which may contain one or more phosphorus atoms.

[0072] Furthermore, (1) the compound should have a molecular weight of less than 2000 daltons / mol, or at least 150 daltons / mol and 1000 daltons / mol or less, or 1500 daltons / mol or less.

[0073] Multiple (1) compounds can be present in the hydrophilic layer, and these may have different chemical compositions, including, but not limited to, different M atoms, different molecular weights, or different numbers or compositions of ethylenically unsaturated groups (e.g., different R groups), or combinations thereof.

[0074] As described above, in some embodiments, (1) at least one ethylenically unsaturated polymerizable group in the compound, but not limited to -(-CH2CH2O-) p Spacer groups such as (wherein the formula, the subscript p is an integer less than or equal to 10, but is more likely to be less than or equal to 10 and 6) can be used to bond to the phosphorus atom in the molecule.

[0075] For example, a useful (1) compound has the following structure (I): [ka] (wherein the formula, the subscript m is one or two of the exemplary hydroxyl groups, the subscript n is an integer of at least 1 and 10 for the exemplary ethyleneoxy group, and R is a hydrogen atom or a substituted or unsubstituted methyl group). If desired, mixtures of such (1) compounds having different R groups, different numbers of hydroxyl groups, or different numbers of ethyleneoxy groups can be used.

[0076] One or more of the (1) compounds described herein are present in the hydrophilic layer disposed on the outer aluminum oxide layer in amounts of at least 10% by weight, or at least 20% by weight, and 60% by weight or less, or 80% by weight or less, based on the total weight of the hydrophilic layer.

[0077] Furthermore, the weight ratio of one or more (1) compounds in the hydrophilic layer to one or more hydrophilic polymers (described below) is 1:4 to 4:1, or more likely 1:3.5 to 2:3. Such weight ratios will generally be the same for wet hydrophilic layer formulations.

[0078] Each of the essential (2) hydrophilic polymers in the hydrophilic layer comprises (a) repeating units, each having at least one amide group, which can be derived from one or more corresponding ethylenically unsaturated polymerizable monomers having amide groups, such as methacrylamide, acrylamide, N,N-dimethylacrylamide, N-hydroxyethylmethacrylamide, and N-(methoxymethyl)acrylamide. Using mixtures of two or more of these monomers, a mixture of (a) repeating units of different compositions or molecular weights can be provided, all having at least one amide group in the repeating unit. The amide groups in the monomers generally do not chemically react during the polymerization process to form (a) repeating units in the hydrophilic copolymer.

[0079] Each (2) one or more hydrophilic polymers also comprises (b) repeating units, each of which has an -OM' group (wherein M' represents a hydrogen, sodium, potassium, or aluminum atom) directly bonded to a phosphorus atom. The bond within the -OM' group may be a covalent or ionic bond. The M' atom is typically a hydrogen, sodium, or potassium atom, and more typically a hydrogen atom if it is present in the hydrophilic layer formulation before the hydrophilic copolymer is applied to the surface of the multilayer aluminum oxide structure described above. When the hydrophilic layer formulation is applied, some of the hydrogen, sodium, or potassium atoms are likely to be converted to aluminum ions, thereby facilitating the bonding of the hydrophilic copolymer to the multilayer aluminum oxide structure.

[0080] Such (b) repeating units can be derived from suitable corresponding ethylenically unsaturated polymerizable monomers having an -OM' group directly bonded to a phosphorus atom, or the -OM' group can be formed after polymerization from a suitable “precursor group” such as -OR' in a phosphate ester group (wherein R' is a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms). Such ethylenically unsaturated polymerizable monomers from which (b) repeating units can be derived may have two or more such -OM' groups, as long as at least one such -OM' group is directly bonded to or attached to a phosphorus atom. Useful ethylenically unsaturated polymerizable monomers of this type include, but are not limited to, those represented by structure (II). CH2=CH(R 1 )-XP(=O)(OM')2 (II) (In the formula, R 1 (wherein M' is a hydrogen atom or a linear or branched alkyl group of 1 to 4 carbon atoms, M' is independently a hydrogen, sodium, or potassium ion, and X is a divalent linking group having a single bond or an appropriate number of linked carbon atoms or a combination of linked carbon atoms and oxygen atoms). Useful divalent X groups include, but are not limited to, those represented by the following structure (III). -C(=O)-(OCH2CH2) q -O- (III) (In the formula, the subscript q is an integer between 1 and 10).

[0081] Specific examples of useful ethylenically unsaturated polymerizable monomers according to structure (II) include vinylphosphonic acid, ethylene glycol acrylate phosphate, and ethylene glycol methacrylate phosphate. Using a mixture of such ethylenically unsaturated polymerizable monomers, (b) repeating units can also be formed such that each (b) repeating unit has at least one -OM group bonded to a phosphorus atom, so that the repeating units can have different chemical compositions or molecular weights.

[0082] (2) If a mixture of hydrophilic polymers is present, it may have different (a) and (b) repeating unit compositions and / or different amounts of (a) and (b) repeating units, or additional repeating units other than (a) and (b) repeating units, as described below.

[0083] (2) Each of the one or more hydrophilic polymers present in the hydrophilic layer may contain at least 60 mol% or at least 80 mol%, and 95 mol% or less or 97 mol% or less of (a) repeating units, based on the total number (or moles) of repeating units in the particular hydrophilic polymer, which all include the sum of (a) repeating units, (b) repeating units, and any other repeating units not defined as (a) and (b) repeating units.

[0084] (2) Each of the one or more hydrophilic polymers present in the hydrophilic layer may contain at least 3 mol% and 25 mol% or less, or 40 mol% or less, of (b) repeating units, based on the total number (or moles) of repeating units in the hydrophilic copolymer, all of which include the sum of (a) repeating units, (b) repeating units, and any other repeating units not defined as (a) and (b) repeating units.

[0085] (2) One or more hydrophilic polymers may contain repeating units that are neither (a) repeating units nor (b) repeating units in amounts of 35 mol% or less, based on the total number (or moles) of repeating units. Those skilled in the art will be able to determine suitable monomers useful for providing these arbitrary repeating units. However, any useful arbitrary repeating unit that is neither (a) repeating units nor (b) repeating units may be a repeating unit containing at least one carboxylic acid group, and all such arbitrary repeating units may be present in amounts typically less than 30 mol%, and more typically less than 20 mol%, based on the total number (or moles) of repeating units in one or more hydrophilic polymers. In some embodiments of the present invention, one or more hydrophilic polymers incorporated into the hydrophilic layer contain only the repeating units (a) and (b) defined above.

[0086] Particularly useful (2) hydrophilic polymers include (a) repeating units derived at least partially from one or more methacrylamides and acrylamides, and (b) repeating units derived at least from vinylphosphonic acid. In some embodiments of the present invention, the (2) hydrophilic polymer includes only such (a) and (b) repeating units.

[0087] Such (2) mixtures of two or more hydrophilic polymers can be used in the hydrophilic layer in any suitable weight combination.

[0088] (2) Ethylene-unsaturated polymerizable monomers useful for preparing one or more hydrophilic polymers can be obtained from various commercial sources or prepared using known ethylenically unsaturated polymerizable monomers and polymerization reaction conditions.

[0089] Furthermore, the hydrophilic layer may include one or more additional hydrophilic homopolymers or copolymers whose composition differs from that of the one or more hydrophilic polymers (2) described above, each having the repeating units (a) and (b). Such additional hydrophilic polymers are known in the art and, if present, generally constitute less than 70% by weight, more typically less than 50% by weight, and even more typically less than 30% by weight, of the total weight of one or more (2) one or more hydrophilic polymers, and such additional hydrophilic polymers can be purchased from known commercial sources or prepared using known starting materials and procedures. The one or more (2) hydrophilic polymers, each having the repeating units (a) and (b) described above, constitute at least 20% by weight or at least 40% by weight of the total weight of the hydrophilic layer, in particular after at least 95% by weight of the coating solvent(s) has been removed from the hydrophilic layer formulation.

[0090] The amount of (2) one or more hydrophilic polymers in the hydrophilic layer can be determined by referring to the amount of (1) compound used and the weight ratio described above.

[0091] As is readily known in the art, hydrophilic layers and hydrophilic layer formulations may contain small amounts of additives, such as inorganic acids (e.g., at least 0.01% by weight of phosphoric acid), salts of inorganic acids, and surfactants. Particularly useful hydrophilic layer formulations and the resulting hydrophilic layers are described below in relation to examples.

[0092] The process used to form the hydrophilic layer is, for example, described in U.S. Patent Application Publication No. 2014 / 0047993 (above).

[0093] ~

[0094] This can be carried out by any suitable method described herein. Alternatively, the post-treatment process can be carried out by directly coating a desired amount of the hydrophilic layer formulation in a suitable solvent such as water onto the outer aluminum oxide layer, and then drying the resulting wet coating. During or after the formation of the hydrophilic layer, it is expected that the -OM and -OM' groups attached to or directly bonded to the phosphorus atoms in (1) the compound and (2) the repeating units (b) of one or more hydrophilic polymers will at least partially react with the surface of the multilayer aluminum oxide structure to form PO-Al bonds.

[0095] After all these essential processes, the substrate of the present invention obtained in any suitable form, such as a flat sheet, continuous web, or coil, is ready for the preparation of a lithographic printing plate according to the present invention.

[0096] Radiosensitive imaging layer and master plate One or more on-press developable radiosensitive imaging layers can be formed or disposed on the hydrophilic layer of the substrate of the present invention in an appropriate manner using suitable on-press developable radiosensitive imaging layer formulations, which are described in more detail below. Such radiosensitive imaging layers generally have negative chemical properties.

[0097] Negative type lithographic printing plate original: The master plate of the present invention can be formed by appropriately applying a negative-type on-press developable radiosensitive composition described below to a suitable substrate of the present invention (above) to form a negative-type radiosensitive image-forming layer on the substrate. Generally, the negative-type radiosensitive composition (and the resulting negative-type radiosensitive image-forming layer) comprises, as essential components, (a) one or more free radical polymerizable components, (b) an initiator composition that provides free radicals when exposed to image-forming radiation (such as infrared radiation as defined herein), and (c) one or more radiation absorbers (such as infrared radiation absorbers), and optionally a polymer binder different from all of (a), (b), and (c), all of which are described in more detail below. Generally, only a single negative-type on-press developable radiosensitive image-forming layer exists in the master plate. This is generally the outermost layer of the master plate, but in some embodiments, an outermost hydrophilic overcoat (also known as a topcoat or oxygen barrier layer) may be present, positioned on top of the single negative-type on-press developable radiosensitive image-forming layer.

[0098] Therefore, the components of the on-press developable radiosensitive imaging layer are designed so that, after image-like exposure, the image-forming plate can be developed on-press using lithographic ink, dampening solution, or a combination of lithographic ink and dampening solution (type and form of chemical compound and their respective amounts). Further details on on-press developability are described below.

[0099] A negative radiosensitive composition (and a radiosensitive imaging layer prepared therefrom) comprises (a) one or more free radical polymerizable components, each containing one or more free radical polymerizable groups (and in some embodiments, two or more such groups) that can be polymerized using a free radical initiation reaction. In some embodiments, the radiosensitive imaging layer comprises two or more free radical polymerizable components, each having the same or different number of free radical polymerizable groups in its molecule.

[0100] Useful free radical polymerizable components may contain one or more free radical polymerizable monomers or oligomers having one or more addition-polymerizable ethylenically unsaturated groups (e.g., two or more such groups). Similarly, crosslinkable polymers having such free radical polymerizable groups can also be used. Oligomers or prepolymers such as urethane acrylates and methacrylates, epoxy acrylates and methacrylates, polyester acrylates and methacrylates, polyether acrylates and methacrylates, and unsaturated polyester resins can be used. In some embodiments, the free radical polymerizable component contains a carboxyl group.

[0101] One or more free-radical polymerizable components have a molecular weight large enough to enhance the mechanical properties of the radiosensitive imaging layer, thereby making the corresponding lithographic printing plate suitable for transport in typical packaging and handling during normal pre-press operations. One or more free-radical polymerizable components having particle sizes of at least 10 nm and 800 nm or less may also be present in the radiosensitive layer as granular material. In such embodiments, a separate non-polymerizable or non-crosslinkable polymer binder (described below) is not required but may be present in the future.

[0102] Free radical polymerizable components include urea urethane (meth)acrylate or urethane (meth)acrylate having multiple (two or more) polymerizable groups. Mixtures of such compounds can be used, where each compound has two or more unsaturated polymerizable groups, and some compounds have three, four or more unsaturated polymerizable groups. For example, free radical polymerizable components can be prepared by reacting DESMODUR® N100 aliphatic polyisocyanate resin (Bayer Corp., Milford, Conn.), based on hexamethylene diisocyanate, with hydroxyethyl acrylate and pentaerythritol triacrylate. Useful free radical polymerizable compounds include NK Ester A-DPH (dipentaerythritol hexaacrylate) available from Kowa American, and Sartomer 399 (dipentaerythritol pentaacrylate), Sartomer 355 (di-trimethylolpropane tetraacrylate), Sartomer 295 (pentaerythritol tetraacrylate), and Sartomer 415 [ethoxylated (20) trimethylolpropane triacrylate] available from Sartomer Company, Inc.

[0103] Numerous other free radical polymerizable components are known in the art and are described in considerable literature, including *Photoreactive Polymers: The Science and Technology of Resists*, A. Reiser, Wiley, New York, 1989, pp. 102–177; *BM Monroe in Radiation Curing: Science and Technology*, edited by S.P.appas, Plenum, New York, 1992, pp. 399–440; and "Polymer Imaging" by A.B.Ohen and P. Walker, *Imaging Processes and Material*, edited by J.M. Sturge et al., Van Nostrand Reinhold, New York, 1989, pp. 226–262. For example, a useful free radical polymerizable component is described in European Patent No. 1,182,033 (Fujimaki et al.).

[0104] It is described in paragraphs beginning with, as well as in U.S. Patent No. 6,309,792 (Hauck et al.), No. 6,569,603 (Furukawa), and No. 6,893,797 (Munnelly et al.). Other useful free radical polymerizable components include those described in U.S. Patent Application Publication No. 2009 / 0142695 (Baumann et al.), which contain a 1H-tetrazole group.

[0105] The above-mentioned useful free-radical polymerizable components can be readily obtained from various commercial sources or prepared using known starting materials and synthesis methods.

[0106] (a) One or more free radical polymerizable components are generally present in the negative radiosensitive imaging layer in amounts of at least 10% and 70% or less by weight, or typically at least 20% and 50% or less by weight, based on the total dry weight of the negative radiosensitive imaging layer.

[0107] The on-press developable radiosensitive imaging layer used in the present invention also comprises (b) an initiator composition that provides free radicals in the presence of a suitable radiation absorber when the on-press developable radiosensitive imaging layer is exposed to suitable imaging radiation to initiate polymerization of one or more free radical polymerizable components. The initiator composition may be a single compound or a combination or system of several compounds.

[0108] Suitable initiator compositions include, but are not limited to, aromatic halogenated sulfonyls; trihalogenoalkyl sulfones; trihalogenoaryl sulfones; imides (such as N-benzoyloxyphthalimide); diazosulfonates; 9,10-dihydroanthracene derivatives; N-aryl, S-aryl, or O-aryl polycarboxylic acids having at least two carboxyl groups, with at least one of which is bonded to a nitrogen, oxygen, or sulfur atom of the aryl moiety; oxime esters and oxime ethers; α-hydroxy- or α-aminoacetophenones; benzoin ethers and esters; peroxides; hydroperoxides; azo compounds; 2,4,5-triarylimidazolyl dimers (such as "HABI"); trihalomethyl-substituted triazines; boron-containing compounds; organoborates, e.g., those described in U.S. Patent No. 6,562,543 (Ogata et al.); and onium salts.

[0109] In particular, for infrared radiation-sensitive compositions and initiator compositions useful for image-forming layers, but not limited to, the following is described in U.S. Patent Application Publication No. 2014 / 0047993 (above)

[0110] This includes onium salts such as ammonium, iodonium, sulfonium, and phosphonium compounds, which are described in detail in the references cited therein. Examples of onium salts include triphenylsulfonium, diphenyliodonium, diphenyldiazonium, and derivatives obtained by introducing one or more substituents to the benzene ring of these compounds. Suitable substituents include, but are not limited to, alkyl, alkoxy, alkoxycarbonyl, acyl, acyloxy, chloro, bromo, fluoro, and nitro groups.

[0111] Examples of anions in onium salts are not limited to these, but include, for example, the halogen anion ClO4 described in U.S. Patent No. 7,524,614 (Tao et al.). - PF6 - BF4 - SbF6 - CH3SO3 - CF3SO3 - , C6H5SO3 - CH3C6H4SO3 - HOC6H4SO3 - ClC6H4SO3 - Examples include the boron anion.

[0112] Onium salts can be obtained by combining an onium salt containing sulfonium or iodonium in its molecule with an onium salt in its molecule. Onium salts can be polyvalent onium salts having at least two onium ion atoms in the molecule bonded through covalent bonds. Among polyvalent onium salts, those containing at least two onium ion atoms in the molecule are useful, and those containing sulfonium or iodonium cations in the molecule are particularly useful. Representative polyvalent onium salts are represented by the following formulas (6) and (7): [ka]

[0113] Furthermore, the specification of Japanese Patent Publication No. 2002-082429 [or U.S. Patent Application Publication No. 2002-0051934 (Ippei et al.)]

[0114] ~

[0115] The onium salts described in the paragraph, or the iodonium borate complexes described in U.S. Patent No. 7,524,614 (above), can also be used in the present invention.

[0116] In some embodiments, the initiator composition may include a combination of iodonium salts, such as a combination of initiator compounds including compound A and compound B as shown below.

[0117] Compound A can be represented by the structure (IV) shown below, and one or more compounds collectively known as Compound B can be represented below by either structure (V) or (VI): [ka]

[0118] In these structures (IV), (V), and (VI), R1, R2, R3, R4, R5, and R6 are independently substituted or unsubstituted alkyl groups or substituted or unsubstituted alkoxy groups, each of which has 2 to 9 carbon atoms (or particularly 3 to 6 carbon atoms). These substituted or unsubstituted alkyl and alkoxy groups can be linear or branched. In many useful embodiments, R1, R2, R3, R4, R5, and R6 are independently substituted or unsubstituted alkyl groups, for example, independently selected substituted or unsubstituted alkyl groups having 3 to 6 carbon atoms.

[0119] Furthermore, at least one of R3 and R4 can be different from R1 or R2; the difference between the total number of carbon atoms of R1 and R2 and the total number of carbon atoms of R3 and R4 is 0 to 4 (i.e., 0, 1, 2, 3, or 4); the difference between the total number of carbon atoms (in total) of R1 and R2 and the total number of carbon atoms (in total) of R5 and R6 is 0 to 4 (i.e., 0, 1, 2, 3, or 4); X1, X2, and X3 are the same or different anions.

[0120] Useful anions include, but are not limited to, ClO4 - , PF6 - , BF4 - , SbF6 - , CH3SO3 - , CF3SO3 - [[ID=1M]], C6H5SO3 - , CH3C6H4SO3 - , HOC6H4SO3 - , ClC6H4SO3 - , and borate anions represented by the following structure (VII): B-(R 1 )(R 2 )(R 3 )(R 4 )<o000647>(VII) (wherein, R 1 , R 2 , R 3 , and R 4 independently represent substituted or unsubstituted alkyl, substituted or unsubstituted aryl (including halogen-substituted aryl groups), substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted cycloalkyl, or substituted or unsubstituted heterocyclic groups, or two or more of R 1 , R 2 , R 3 , and R 4 can combine together to form a substituted or unsubstituted heterocyclic ring containing a boron atom, such a ring having a maximum of 7 carbon, nitrogen, oxygen, or nitrogen atoms) is included. R 1 , R 2 , R 3 , and R 4 It should be noted that there is a possible error in the original text where "C6H5SO3" is written as "C6H4SO3" in the translation process. Please check the original text for accuracy. Also, "<o000647>" should be " " for correct representation.Any of the above substituents can include chloro, fluoro, nitro, alkyl, alkoxy, and acetoxy groups. In some embodiments, R 1 , R 2 , R 3 , and R 4 All of these groups are either the same or different substituted or unsubstituted aryl groups, for example, substituted or unsubstituted phenyl groups, or more likely, all of these groups are unsubstituted phenyl groups. In many embodiments, at least one of X1, X2, and X3 is a tetraarylborate anion containing the same or different aryl groups, or in particularly useful embodiments, one or more are tetraphenylborate anions, or each of X1, X2, and X3 is a tetraphenylborate anion.

[0121] If desired, a mixture of compound B, which is the compound represented by structure (V) or (VI), may be used. Many useful compounds represented by structures (IV), (V), and (VI) can be obtained from commercial sources such as Sigma-Aldrich, or can be prepared using known synthetic methods and readily available starting materials.

[0122] The components useful for the above initiator compositions can be obtained from various commercial sources or prepared using known synthetic methods and starting materials.

[0123] Generally, an initiator composition sufficient to provide one or more polymerization initiators in an amount of at least 0.5% and 20% or less by weight, or typically at least 2% and 15% or less by weight, or even at least 4% and 12% or less by weight, based on the total dry weight of all on-press developable radiosensitive imaging layers, is present in the on-press developable radiosensitive imaging layer.

[0124] Furthermore, the on-press developable radiosensitive imaging layer also comprises (c) one or more radioactive absorbers that provide desired radiosensitivity, or convert radiation into heat, or both. In some embodiments, the on-press developable radiosensitive layer comprises one or more different infrared radioactive absorbers so that the lithographic printing plate can be imaged using an infrared emitting laser, for example, in response to digital information. The present invention is also applicable to lithographic printing plates designed to be imaged with visible lasers such as a violet laser having an emission peak at about 405 nm, a laser having an emission peak at about 488 nm or 532 nm, or UV radiation having a significant emission peak below 400 nm. In such embodiments, the radioactive absorbers may be selected to suit the radiation source, and many useful examples are known in the art and are sometimes called “sensitizers”. Useful radioactive absorbers of this type are described, for example, in paragraph 11 (lines 10-43) of U.S. Patent No. 7,285,372 (Baumann et al.).

[0125] In most embodiments of the present invention, an on-press developable negative-type radiosensitive image-forming layer comprises one or more infrared radiation absorbers to provide desired infrared radiation sensitivity. Useful infrared radiation absorbers may be pigments or infrared radiation absorbing dyes. Suitable dyes may also be described, for example, in U.S. Patent No. 5,208,135 (Patel et al.), No. 6,153,356 (Urano et al.), No. 6,309,792 (Hauck et al.), No. 6,569,603 (Furukawa), No. 6,797,449 (Nakamura et al.), No. 7,018,775 (Tao), No. 7,368,215 (Munnelly et al.), No. 8,632,941 (Balbinot et al.), and U.S. Patent Application Publication No. 2007 / 056457 (Iwai et al.). In some infrared radiation-sensitive embodiments, it is desirable that at least one infrared radiation absorber in the infrared radiation-sensitive imaging layer be a cyanine dye containing a tetraaryl borate anion, such as a tetraphenyl borate anion. An example of such a dye is described in U.S. Patent Application Publication No. 2011 / 003123 (Simpson et al.).

[0126] In addition to low molecular weight IR absorption dyes, IR dye chromophores bound to polymers can also be used. Furthermore, IR dye cations can also be used; that is, the cation is the IR absorption moiety of a dye salt that ionically interacts with a polymer containing a carboxy, sulfo, phospho, or phosphono group in its side chain.

[0127] The above-mentioned useful radioactive absorbers can be readily obtained from various commercial sources or prepared using known starting materials and synthesis methods.

[0128] The total amount of one or more radiative absorbers in an on-press developable radiosensitive imaging layer is at least 0.5% and 30% or less by weight, or typically at least 1% and 15% or less by weight, based on the total dry weight of the on-press developable radiosensitive imaging layer.

[0129] In many embodiments, the on-press developable radiosensitive imaging layer may, but is preferable, further contain one or more (d) polymer binders (or materials acting as polymer binders) for all of the materials in the described layer. Such polymer binders are distinct from all of the (a), (b), and (c) materials described above. These polymer binders are generally non-crosslinkable and non-polymerizable.

[0130] Such (d) polymer binders can be selected from several polymer binder materials known in the art, including polymers comprising repeating units having side chains containing polyalkylene oxide segments, such as those described in U.S. Patent No. 6,899,994 (Huang et al.). Other useful (d) polymer binders comprise two or more repeating units having different side chains containing polyalkylene oxide segments, such as those described in International Publication No. 2015-156065 (Kamiya et al.). Some of these (d) polymer binders may further comprise repeating units having pendant cyano groups, such as those described in U.S. Patent No. 7,261,998 (Hayashi et al.).

[0131] Some useful (d) polymer binders can exist in particulate form, i.e., in the form of discrete, non-aggregated particles. Such discrete particles may have an average particle size of at least 10 nm and 1500 nm or less, or typically at least 80 nm and 600 nm or less, and are generally uniformly distributed within an on-press developable radiosensitive imaging layer. For example, one or more useful (d) polymer binders may exist in the form of particles having an average particle size of at least 50 nm and 400 nm or less. The average particle size can be determined by various known methods, including measuring particles in electron scanning microscope images and averaging a set number of measurements.

[0132] In some embodiments, (d) the polymer binder exists in the form of particles having an average particle size smaller than the average dry thickness (t) of the on-press developable radiosensitive imaging layer. The average dry thickness (t) in micrometers (μm) is calculated by the following formula: t = w / r (In the formula, w is g / m 2 The dry coating coverage of an on-press developable radiosensitive imaging layer in units of r, where r is 1 g / cm². 3 (i.e.) For example, in such embodiments, (d) the polymer binder may constitute at least 0.05% and 80% or less, or more likely at least 10% and 50% or less, of the on-press developable radiosensitive imaging layer.

[0133] (d) The polymer binder may also have a skeleton comprising a plurality of (at least two) urethane moieties, as well as a pendant group comprising a polyalkylene oxide segment.

[0134] Other useful (d) polymer binders may include polymerizable groups such as acrylate esters, methacrylate esters, vinylaryl and allyl groups, as well as alkali-soluble groups such as carboxylic acids. Some of these useful (d) polymer binders are described in U.S. Patent Application Publication No. 2015 / 0099229 (Simpson et al.) and U.S. Patent No. 6916595 (Fujimaki et al.).

[0135] Useful (d) polymer binders generally have a weight-average molecular weight (Mw) of at least 2,000 and 500,000 or less, or at least 20,000 and 300,000 or less, as measured by gel permeation chromatography (polystyrene standard).

[0136] Useful (d) polymer binders can be obtained from various commercial sources or prepared using known procedures and starting materials, for example, as described in the publications above.

[0137] The total (d) polymer binder may be present in the on-press developable radiosensitive imaging layer in an amount of at least 10% and 70% or less by weight, or more likely at least 20% and 50% or less by weight, based on the total dry weight of the on-press developable radiosensitive imaging layer.

[0138] Other polymer materials known in the art (different from polymer binders (d)) can be present in the on-press developable radiosensitive imaging layer, and such polymer materials are generally more hydrophilic or hydrophobic than polymer binders (d) described above. Examples of such hydrophilic polymer binders include, but are not limited to, cellulose derivatives, e.g., hydroxypropylcellulose, carboxymethylcellulose, and polyvinyl alcohols with various degrees of saponification. More hydrophobic polymer binders are less developable than polymer binders (d) described above and typically have an acid value of less than 20 mg KOH / g for all acidic groups with a pKa of less than 7 and their corresponding salts. Such hydrophobic polymer binders typically contain less than 10% by weight, more typically less than 5% by weight, of segments selected from the group consisting of hydroxyl groups, -(CH2CH2-O)-, and -C(=O)NH2, which contribute to the hydrophilicity of the binder. Examples of such hydrophobic polymer binders, though not limited to these, include poly(methyl methacrylate), poly(benzyl methacrylate), and polystyrene.

[0139] Any additional additives to the on-press developable radiosensitive imaging layer may include organic dyes or organic dye precursors and chromogens known in the art. Useful organic dyes or organic dye precursors include, but are not limited to, phthalides and fluoranleuco dyes having a lactone skeleton having an acid-dissociable lactone skeleton, e.g., those described in U.S. Patent No. 6,858,374 (Yanaka). Any such additives can be used as printout colorants and may be present in amounts of at least 1% and no more than 10% by weight, based on the total dry weight of the on-press developable radiosensitive imaging layer. Other useful printout colorants are known in the art and may include, for example, azo dyes, triarylmethane dyes, cyanine dyes, and spirolactone or spirolactam colorants, e.g., those described in U.S. Patent Application Publication No. 2009 / 0047599 (Horne et al.).

[0140] The on-press developable radiosensitive imaging layer may include, for example, cross-linked polymer particles having an average particle size of at least 2 μm, or at least 4 μm, and no more than 20 μm, as described in U.S. Patent No. 8,383319 (Huang et al.), U.S. Patent No. 8,105751 (Endo et al.), and U.S. Patent No. 9,366962 (Kamiya et al.). Such cross-linked polymer particles may be present only in the on-press developable radiosensitive imaging layer, only in the hydrophilic overcoat (described below) if present, or in both the on-press developable radiosensitive imaging layer and the hydrophilic overcoat if present.

[0141] On-press developable radiosensitive imaging layers may also include a variety of other optional additives, including, but not limited to, conventional amounts, dispersants, humectants, biocides, plasticizers, surfactants for coating or other properties, viscosity modifiers, pH adjusters, desiccants, defoamers, preservatives, antioxidants, developing aids, rheological modifiers, or combinations thereof, or any other additives commonly used in the lithographic field. On-press developable radiosensitive imaging layers may also include phosphate (meth)acrylates generally having a molecular weight greater than 250, as described in U.S. Patent No. 7,429,445 (Munnelly et al.).

[0142] Hydrophilic overcoat: In some embodiments of negative-type lithographic printing plates, the on-press developable radiosensitive image-forming layer is the outermost layer with no layers placed on top of it, but the plate can be designed with a hydrophilic layer (also known in the art as a hydrophilic overcoat, oxygen barrier layer, or topcoat) placed on (or immediately above) the on-press developable radiosensitive image-forming layer (without an intermediate layer between these two layers). If present, this hydrophilic overcoat is generally the outermost layer of the plate.

[0143] Such hydrophilic overcoats may contain one or more film-forming water-soluble polymer binders in amounts of at least 60% and 100% or less by weight, based on the total dry weight of the hydrophilic overcoat. Such film-forming water-soluble (or hydrophilic) polymer binders may include modified or unmodified poly(vinyl alcohol) with a degree of saponification of at least 30%, at least 75%, at least 90%, and 99.9% or less.

[0144] Furthermore, one or more acid-modified poly(vinyl alcohols) can be used as film-forming water-soluble (or hydrophilic) polymer binders in hydrophilic overcoats. For example, at least one modified poly(vinyl alcohol) may be modified with an acid group selected from the group consisting of carboxylic acid, sulfonic acid, sulfuric acid ester, phosphonic acid, and phosphate ester groups. Examples of such materials, but not limited to these, include sulfonic acid-modified poly(vinyl alcohol), carboxylic acid-modified poly(vinyl alcohol), quaternary ammonium salt-modified poly(vinyl alcohol), glycol-modified poly(vinyl alcohol), or combinations thereof.

[0145] The hydrophilic overcoat may also include crosslinked polymer particles having an average particle size of at least 2 μm, such as those described in U.S. Patent No. 8383319 (Huang et al.) and U.S. Patent No. 8105751 (Endo et al.).

[0146] The hydrophilic overcoat must contain at least 0.1 g / m² 2 and 4g / m 2 The following dry coating coverages are typically at least 0.15 g / m². 2 and 2.5 g / m 2 The following dry coating coverages may be provided. In some embodiments, the dry coating coverage is 0.1 g / m², such that the hydrophilic overcoat is relatively thin. 2 and low and 1.5 g / m 2 The following, or at least 0.1 g / m 2 and 0.9 g / m 2 The following applies:

[0147] The hydrophilic overcoat may optionally include organic wax particles dispersed in one or more film-forming water-soluble (or hydrophilic) polymer binders, as described, for example, in U.S. Patent Application Publication No. 2013 / 0323643 (Balbinot et al.).

[0148] Preparation of lithographic printing plates The radiosensitive lithographic printing plates of the present invention can be provided in the following ways: A radiosensitive imaging layer formulation containing the above materials (for either negative or positive chemistry) can be applied to a substrate of the present invention, usually a continuous substrate roll or web, using any suitable apparatus and procedure such as spin coating, knife coating, gravure coating, die coating, slot coating, bar coating, wire rod coating, roller coating, or extrude hopper coating. The radiosensitive imaging layer formulation can also be applied onto a suitable substrate by spraying. Typically, once the radiosensitive imaging layer formulation is applied to a suitable wet coverage, it is dried by a suitable method known in the art to obtain the desired dry coverage described below, thereby obtaining a radiosensitive continuous article that can be in any suitable form, such as a web, from which individual plates can be prepared using known manufacturing processes.

[0149] The manufacturing method typically involves mixing various components required for a particular radiosensitive imaging layer chemistry in a suitable organic solvent or a mixture thereof [such as methyl ethyl ketone (2-butanone), methanol, ethanol, 1-methoxy-2-propanol, isopropyl alcohol, acetone, γ-butyrolactone, n-propanol, tetrahydrofuran, and others readily known in the art, as well as mixtures thereof], applying the resulting radiosensitive imaging layer formulation to a continuous substrate web, and removing the solvent(s) by evaporation under suitable drying conditions. Further details of such manufacturing features are described in U.S. Patent Application Publication No. 2014 / 0047993 (above).

[0150] After proper drying, the dry coverage of the negative-type on-press developable radiation-sensitive image-forming layer (particularly infrared radiation-sensitive) on the substrate of the present invention is generally at least 0.1 g / m². 2 and 4g / m 2 The following, or at least 0.4 g / m² 2 and 2g / m 2The following are the values, but other dry coverage values ​​can be used if desired.

[0151] As described above, in some negative plate embodiments, a suitable aqueous hydrophilic overcoat formulation can be applied to a dried, on-press developable radiosensitive image-forming layer using known coating and drying conditions, apparatus, and procedures.

[0152] Under actual manufacturing conditions, the result of these coating operations is a continuous web or roll of radiosensitive lithographic plate material having an on-press developable radiosensitive image-forming layer and any of the above layers disposed on the substrate of the present invention.

[0153] Individual rectangular lithographic printing plates are formed from this resulting continuous radiative-sensitive web or roll by slitting it to form multiple longitudinal strips, each having a width equal to one dimension of the rectangular lithographic printing plate. A length adjustment process is used to create transverse cuts across each strip at intervals equal to the other dimensions of the rectangular lithographic printing plate, thereby forming individual plates having a square or rectangular shape.

[0154] Image formation (exposure) conditions During use, the radiosensitive lithographic printing plate of the present invention can be exposed on-press to a suitable exposure radiation source depending on the radiation absorber (or sensitizer) present in one or more radiosensitive imaging layers. For example, a negative lithographic printing plate containing an infrared radiation absorber can be imaged with an infrared laser emitting significant radiation in the range of at least 750 nm and 1400 nm or less, or at least 800 nm and 1250 nm or less. However, some on-press developable negative lithographic printing plates can be imaged in the UV, violet, or visible regions of the electromagnetic spectrum using a suitable imaging radiation source (e.g., 250 nm to less than 750 nm). The result of such image-like exposure is to provide exposed and unexposed regions within one or more on-press developable radiosensitive imaging layers.

[0155] Image formation or exposure radiation can be performed using image-forming or exposure radiation from an emitting laser (or an array of such lasers). If desired, multiple wavelengths of image-forming radiation can be used simultaneously, for example, to perform image formation using multiple infrared radiation wavelengths. The laser used to expose the master plate is usually a diode laser due to the reliability and low maintenance of the diode laser system, but other lasers such as gas or solid-state lasers can also be used. Combinations of power, intensity, and exposure time for radiative imaging will be readily apparent to those skilled in the art.

[0156] The imaging apparatus can be configured as a flatbed recorder or a drum recorder, with the radiation-sensitive lithographic printing plate mounted on the inner or outer cylindrical surface of the drum. Useful examples of infrared imaging apparatuses are available as models of the Kodak® Trendsetter platesetter (Eastman Kodak Company) and the NEC AMZISetter X series (NEC Corporation, Japan), which include laser diodes that emit radiation at a wavelength of approximately 830 nm. Other suitable infrared imaging apparatuses include the Screen PlateRite 4300 series or 8600 series platesetters (Screen USA, available from Chicago, Illinois) that operate at a wavelength of 810 nm, or thermal CTP platesetters from Panasonic Corporation (Japan).

[0157] The infrared radiation imaging energy is at least 30 mJ / cm², depending on the sensitivity of the infrared radiation-sensitive imaging layer. 2 and 500 mJ / cm 2 The following are typically at least 50 mJ / cm² 2 and 300 mJ / cm 2 The following is possible:

[0158] Useful UV and "purple" imaging systems include Prosetter (Heidelberger Druckmaschinen, Germany), Luxel V8 / V6 series (Fuji, Japan), Python (Highwater, UK), MakoNews, Mako 2, and Mako 8 (ECRM, USA), Micro (Screen, Japan), Polaris and Advantage (AGFA, Belgium), LS Jet (Multiformat) and Smart"n"Easy Jet (Krause, Germany), as well as the VMAX series (DotLine, Germany) and Imagesetter.

[0159] Image formation in the electromagnetic spectrum from UV to visible region, particularly in the UV region (250 nm to 450 nm), requires at least 0.5 kW / cm². 3 and 50 kW / cm² 3 At least 0.01 mJ / cm² with the following power densities 2 and 0.5 mJ / cm 2 This can be done using the following energy sources.

[0160] Processing (developing) and printing After image exposure, an exposed negative-type on-press developable radiosensitive lithographic printing plate, having exposed and unexposed regions in an on-press developable radiosensitive image-forming layer, can be processed in an appropriate manner to remove the unexposed regions and any hydrophilic overcoats present, leaving the cured exposed regions intact.

[0161] For example, the negative type lithographic printing plate of the present invention can be developed on press using lithographic ink, dampening solution, or a combination of lithographic ink and dampening solution. In such embodiments, the image-forming radiosensitive lithographic printing plate of the present invention can be mounted on a printing press, and then the printing operation is initiated. Unexposed areas of the radiosensitive image-forming layer are removed by appropriate dampening solution, lithographic ink, or a combination thereof when the first print is produced. Typical components of aqueous dampening solution include pH buffers, desensitizers, surfactants and wetting agents, humectants, low-boiling solvents, biocides, defoamers, and metal ion chelating agents. A typical example of dampening solution is Varn Litho Etch 142W + Varn PAR (alcohol sub) (available from Varn International, Addison, IL).

[0162] In a typical start-up of a sheet-fed printing press, the dampening roller is first engaged to supply dampening water to the mounted image-forming plate, swelling the exposure-radiosensitive image-forming layer in at least the unexposed areas. After a few rotations, the ink roller is engaged to supply lithographic ink to cover the entire printing surface of the lithographic plate. Typically, within 5 to 20 rotations after the ink roller is engaged, the printing sheet is fed, and the formed ink-dampening water emulsion is used to remove the unexposed areas of the radiosensitive image-forming layer from the lithographic plate, as well as any material on the blanket cylinder, if present. The present invention provides at least the following embodiments, individually or in any suitable combination:

[0163] 1. A substrate having a surface, A radioactive image-forming layer that can be developed on press and placed on the surface of a substrate A lithographic printing plate original, The circuit board is An aluminum-containing plate having a granulated and etched surface; An inner aluminum oxide layer disposed on a granulated and etched surface, wherein the inner aluminum oxide layer has an average dry thickness (T) of at least 300 nm and 3000 nm or less.i ) has an average inner pore diameter (D) of 100 nm or less. i An inner aluminum oxide layer containing numerous inner micropores having; An outer aluminum oxide layer disposed on an inner aluminum oxide layer, wherein the outer aluminum oxide layer has an average outer micropore diameter (D) of at least 15 nm and 30 nm or less. o It includes numerous outer micropores having ) and an average dry thickness (T) of at least 30 nm and 650 nm or less. o ) having an outer aluminum oxide layer; At least 0.0002 g / m³ 2 and 0.1 g / m 2 A hydrophilic layer disposed on the outer aluminum oxide layer with the following dry coverage, wherein the hydrophilic layer is: (1) Compounds having one or more ethylenically unsaturated polymerizable groups, one or more -OM groups in which at least one of the groups is directly bonded to a phosphorus atom, and a molecular weight of less than 2000 daltons / mol, where M represents a hydrogen, sodium, potassium, or aluminum atom; and (2) A hydrophilic layer comprising one or more hydrophilic polymers, each comprising repeating units, each containing at least (a) an amide group and (b) an -OM' group directly bonded to a phosphorus atom, where M' represents a hydrogen, sodium, potassium, or aluminum atom. A lithographic printing plate, including the original plate.

[0164] 2. The hydrophilic layer has a density of at least 0.005 g / m 2 and 0.08 g / m 2 A lithographic printing plate according to Embodiment 1, arranged on an outer aluminum oxide layer with the following dry coverage.

[0165] 3. The outer aluminum oxide layer has at least 500 micropores / μm 2 and 3000 micropores / μm 2 The following micropore density (C o ) has a porosity (P) of 0.3 to 0.8. o ) has P o3.14(C o )(D o 2 A lithographic printing plate according to Embodiment 1 or 2, defined as ) / 4000000.

[0166] 4. The outer aluminum oxide layer has at least 500 micropores / μm 2 and 3000 micropores / μm 2 The following micropore density (C o ) has a porosity (P) of 0.3 to 0.5. o ) has P o 3.14(C o )(D o 2 A lithographic printing plate according to any one of Embodiments 1 to 3, defined as ) / 4000000.

[0167] 5. The outer aluminum oxide layer has an average dry thickness of at least 130 nm (T o ) has an outer aluminum oxide layer directly placed on top of the inner aluminum oxide layer; the average dry thickness of the inner aluminum oxide layer (T i The ) is at least 650 nm, and the average inner pore size (D i ) is 15 nm or less, and the average outer pore size (D o A lithographic printing plate according to any one of Embodiments 1 to 4, which is less than ).

[0168] 6.D o D i A lithographic printing plate according to any one of embodiments 1 to 5, wherein the ratio to is greater than 1.1:1.

[0169] 7.T i A lithographic printing plate according to any one of Embodiments 1 to 6, wherein the wavelengths are at least 650 nm and 1500 nm or less.

[0170] 8. The substrate further includes an intermediate aluminum oxide layer disposed between the inner aluminum oxide layer and the outer aluminum oxide layer, wherein the intermediate aluminum oxide layer has an average dry thickness (T) of at least 60 nm and 300 nm or less.m ) has an average intermediate micropore diameter (D) of at least 20 nm and 60 nm or less. m It contains numerous intermediate micropores having D m However, D i Larger than D o Larger than the average dry thickness of the outer aluminum oxide layer (T o A lithographic printing plate according to any one of Embodiments 1 to 7, wherein the n-f is less than 150 nm.

[0171] 9. The outer aluminum oxide layer is directly placed on the inner aluminum oxide layer, and the average micropore size (D) of the inner aluminum oxide layer is i The outer aluminum oxide layer has a minimum of 20 nm of fine pore size (D o A lithographic printing plate according to any one of embodiments 1 to 8, which is larger than ).

[0172] 10. (1) At least one ethylenically unsaturated polymerizable group in the compound is bonded to a phosphorus atom to which the -OM group is bonded, and the spacer group is of the formula -(-CH2CH2O-) p A lithographic printing plate according to any one of embodiments 1 to 9, represented by -(wherein the formula, the subscript p is an integer of at least 1 and less than or equal to 10).

[0173] 11. (1) A lithographic printing plate according to any one of Embodiments 1 to 10, wherein the compound has a molecular weight of at least 100 daltons / mol and 1500 daltons / mol or less.

[0174] 12. (1) The compound is of formula: -C(R')=CH2 A lithographic printing plate according to any one of Embodiments 1 to 11, having at least one ethylenically unsaturated polymerizable group represented by R', where R' represents a hydrogen atom or an unsubstituted linear or branched alkyl group having 1 to 4 carbon atoms.

[0175] 13. The lithographic printing plate according to Embodiment 12, wherein R is a hydrogen atom or an unsubstituted methyl group.

[0176] 14. A lithographic printing plate according to any one of Embodiments 1 to 13, wherein the compound (1) is present in amounts of at least 10% by weight and 80% by weight or less, based on the total weight (solid) of the hydrophilic layer, or the weight ratio of one or more of the (1) compounds in the hydrophilic layer to one or more of the hydrophilic polymers (2) is 1:4 to 4:1.

[0177] 15. A lithographic printing plate according to any one of Embodiments 1 to 14, wherein the compound (1) is present in amounts of at least 10% by weight and 80% by weight or less, based on the total weight (solid) of the hydrophilic layer, or the weight ratio of one or more of the (1) compounds in the hydrophilic layer to one or more of the hydrophilic polymers (2) is 1:3.5 to 2:3.

[0178] 16. (1) The compound has the following structure (I) [ka] A lithographic printing plate according to any one of Embodiments 1 to 15, represented by, where the subscript m is 1 or 2, the subscript n is an integer of at least 1 and 10 or less, and R is a hydrogen atom or a substituted or unsubstituted methyl group.

[0179] 17. A lithographic printing plate according to any one of Embodiments 1 to 16, wherein, based on the total number (or moles) of repeating units in one or more hydrophilic polymers, (a) repeating units are present in the hydrophilic polymer in amounts of at least 60 mol% and 97 mol% or less, and (b) repeating units are present in the hydrophilic polymer in amounts of at least 3 mol% and 40 mol% or less.

[0180] 18.(a) A lithographic printing plate according to any one of Embodiments 1 to 17, wherein the repeating unit is derived from one or more of methacrylamide, acrylamide, N,N-dimethylacrylamide, N-hydroxyethylmethacrylamide, and N-(methoxymethyl)acrylamide.

[0181] 19. (b) The repeating unit has the following structure (II) CH2=CH(R 1 )-XP(=O)(OM')2 (II) Derived from one or more ethylenically unsaturated polymerizable monomers represented by R 1 A lithographic printing plate according to any one of Embodiments 1 to 18, wherein M' is a hydrogen atom or a linear or branched alkyl group of 1 to 4 carbon atoms, M' is independently a hydrogen, sodium, or potassium ion, and X is a divalent linking group having a single bond or an appropriate number of linked carbon atoms or a combination of linked carbon atoms and oxygen atoms.

[0182] 20. The divalent group has the following structure (III) -C(=O)-(OCH2CH2) q -O- (III) A lithographic printing plate according to Embodiment 19, represented by , where the subscript q is an integer from 1 to 10.

[0183] 21. The radiosensitive image-forming layer that can be developed on press is of the negative type. (a) one or more free radical polymerizable components; (b) an initiator composition that provides free radicals when a radiosensitive imaging layer is exposed to imaging radiation; (c) One or more radiation absorbers; optionally, (d) A polymer binder different from all of (a), (b), and (c) and A lithographic printing plate according to any one of embodiments 1 to 20, including the above.

[0184] 22. A lithographic printing plate according to any one of Embodiments 1 to 21, wherein (2) one or more hydrophilic copolymers in the hydrophilic layer comprises (a) repeating units derived from at least one or more methacrylamides and acrylamides, or (b) repeating units derived from at least vinylphosphonic acid.

[0185] 23. A lithographic printing plate according to any one of Embodiments 1 to 22, wherein the on-press developable radiosensitive image-forming layer is negative, sensitive to infrared radiation, and comprises one or more infrared radiation absorbers.

[0186] 24. A lithographic printing plate according to any one of embodiments 21 to 23, further comprising (d) a polymer binder in the form of particles, wherein the on-press developable negative-type radiosensitive layer.

[0187] 25. A method for providing a lithographic printing plate, To form an image-like exposure image-forming layer having exposed and unexposed regions, the process involves exposing a lithographic printing plate according to any one of Embodiments 1 to 24 to image-like exposure with image-forming radiation, A method for forming a lithographic printing plate, comprising the step of removing an unexposed area from an image-like exposure image-forming layer on a machine.

[0188] 26. The method according to Embodiment 25, wherein the lithographic printing plate original comprises one or more infrared radiation absorbers, and the image-like exposure is performed using infrared radiation.

[0189] 27. A method for preparing a lithographic printing plate according to any one of Embodiments 1 to 24, wherein, in order: A process for providing an aluminum-containing plate having an electrochemically or mechanically granulated and etched surface; A step of subjecting an aluminum-containing plate to a first anodizing process in order to form an outer aluminum oxide layer on an electrochemically or mechanically granulated and etched surface, wherein the outer aluminum oxide layer has an average outer pore size (D) of at least 15 nm and 30 nm or less. o It includes numerous outer micropores having ) and an average dry thickness (T) of at least 30 nm and 650 nm or less. o ) a process having; The process of rinsing the outer aluminum oxide layer; A process of subjecting an aluminum-containing plate to a second anodization process to form an inner aluminum oxide layer under an outer aluminum oxide layer, wherein the inner aluminum oxide layer has an average dry thickness (T i ) of at least 300 nm and 3000 nm or less; and includes a number of inner micropores having an average inner micropore diameter (D i ) of 100 nm or less; A step of rinsing the outer aluminum oxide layer and the inner aluminum oxide layer; A step of forming an on-press-developable radiation-sensitive image-forming layer on the outer aluminum oxide layer; A step of providing a hydrophilic layer on the outer aluminum oxide layer after rinsing the outer aluminum oxide layer and the inner aluminum oxide layer and before forming an on-press-developable radiation-sensitive image-forming layer on the outer aluminum oxide layer, wherein the hydrophilic layer is (1) A compound having one or more ethylenically unsaturated polymerizable groups, at least one of which is one or more -OM groups directly bonded to a phosphorus atom, and a molecular weight of less than 2000 daltons / mol, where M represents a hydrogen, sodium, potassium, or aluminum atom; and (2) One or more hydrophilic polymers including repeating units each including at least (a) an amide unit and (b) a repeating unit including an -OM' group directly bonded to a phosphorus atom, where M' represents a hydrogen, sodium, potassium, or aluminum atom, The hydrophilic layer is disposed on the outer aluminum oxide layer with a dry coating degree of at least 0.0002 g / m 2 and 0.1 g / m 2 or less. The method includes the above steps.

[0190] The following examples are provided to illustrate the implementation of the present invention and are not intended to be limiting in any way.

[0191] Examples of the Invention | 1 - 3 | and Comparative Examples | 1 - 8: Aluminum-containing substrates A and B, used to prepare the negative type lithographic printing plates used in the embodiment of the invention and the comparative embodiment, were prepared according to the general process described above.

[0192] Type 1 support: Using this aluminum-containing support, the original plates for Invention Examples 1, 2, and 5-7, as well as Comparative Examples 1-5, were prepared. Hydro 1052 aluminum alloy strips or webs with a thickness of 0.28 mm (available from Norsk Hydro ASA, Norway) were used as the aluminum-containing "plate" stock or support. Both pre-etching and post-etching steps were performed in an alkaline solution under known conditions. These etched aluminum supports were roughened (or granulated) by electrochemical means in a hydrochloric acid solution at approximately 23°C to obtain an arithmetic mean roughness (Ra) of 0.5 μm on the surface of the aluminum-containing supports. The aluminum-containing supports were then subjected to two individual anodizing processes as described in U.S. Patent No. 10828884 (above). The first anodizing process was performed using phosphoric acid as the electrolyte to obtain an average micropore size (D o )19 nm and average dry thickness (T o An outer aluminum oxide layer with a pore size of 190 nm was formed. Then, a second anodic oxidation process was carried out using sulfuric acid as the electrolyte to obtain an average pore size (D i ) Less than 10 nm and average dry thickness (T i An inner aluminum oxide layer with a wavelength of 800 nm was formed. These two anodizing steps were carried out in a continuous process on a typical manufacturing line used to produce lithographic printing plates.

[0193] Type 2 support: Using this support, the original plate for Invention Example 3 was prepared. A 0.28 mm thick Hydro 1052 aluminum alloy strip or web (Norsk Hydro ASA, available from Norway) was used as the aluminum-containing "plate" stock or support. Both pre-etching and post-etching steps were performed in an alkaline solution under known conditions. The etched aluminum support was roughened (or granulated) by electrochemical means in a hydrochloric acid solution at approximately 23°C to obtain an arithmetic mean roughness (Ra) of 0.5 μm on the surface of the aluminum-containing support. Subsequently, the aluminum-containing substrate was subjected to two individual anodizing processes. The first anodizing process was performed using phosphoric acid as the electrolyte to obtain an average pore size (D o )19 nm and average dry thickness (T o An outer aluminum oxide layer with a 60 nm pore size was formed. Then, a second anodic oxidation process was carried out using phosphoric acid as the electrolyte to achieve an average pore size (D i ) 70 nm and average dry thickness (T i An inner aluminum oxide layer with a 500 nm wavelength was formed. These two anodizing steps were carried out in a continuous process on a typical manufacturing line used to produce lithographic printing plates.

[0194] Type 3 support: Using this support, the original plate for Invention Example 4 was prepared. A 0.28 mm thick Hydro 1052 aluminum alloy strip or web (Norsk Hydro ASA, available from Norway) was used as the aluminum-containing "plate" stock or support. Both pre-etching and post-etching steps were performed in an alkaline solution under known conditions. The etched aluminum support was roughened (or granulated) by electrochemical means in a hydrochloric acid solution at approximately 23°C to obtain an arithmetic mean roughness (Ra) of 0.5 μm on the surface of the aluminum-containing support. The aluminum-containing substrate was then subjected to two separate anodizing processes as described in U.S. Patent No. 10828884 (Merka et al.) and U.S. Patent No. 11117423 (Merka, Mueller, Kemmling, and Blum), both assigned to the assignees of the present invention. The first anodizing process was performed using phosphoric acid as the electrolyte to obtain the average micropore size (D o )19 nm and average dry thickness (T o An outer aluminum oxide layer with a 60 nm pore size was formed. Then, a second anodic oxidation process was carried out using phosphoric acid as the electrolyte to achieve an average pore size (D m )23 nm and average dry thickness (T m An intermediate aluminum oxide layer having a pore size of 160 nm was formed. A third anodic oxidation process was carried out using sulfuric acid as the electrolyte to obtain an average pore size (D i ) Less than 10 nm and average dry thickness (T i An inner aluminum oxide layer with a wavelength of 800 nm was formed. These three anodizing steps were carried out in a continuous process on a typical manufacturing line used to produce lithographic printing plates.

[0195] Preparation of hydrophilic layer formulations: Hydrophilic layer formulations HL-1 to HL-10, evaluated below, were prepared using the materials and quantities shown in Tables I and II below.

[0196] [Table 1]

[0197] [Table 2]

[0198] Each hydrophilic layer formulation shown in Table I is coated onto one of the Type 1, Type 2, or Type 3 supports using a re-wound coating bar, dried at 70°C for 2 minutes, cooled to 20-27°C to obtain a hydrophilic layer on the outer aluminum oxide layer, and subsequently dried to obtain a hydrophilic layer of 0.03 g / m² on a Type 1, Type 2, or Type 3 substrate. 2 The degree of hydrophilic layer coverage was obtained.

[0199] Preparation of negative-type on-press developing plates: A coating formulation for an infrared radiation-sensitive imaging layer, which is developable on press in a negative format, was prepared using a bar coater with the components and amounts shown in Tables III and IV below, dried at 50°C for 60 seconds, and then coated at 0.9 g / m². 2 The dry coating weight was obtained.

[0200] The raw materials identified below in Tables III and IV can be obtained from one or more commercial sources of chemicals, or were prepared using known synthetic methods and starting materials.

[0201] [Table 3]

[0202] [Table 4]

[0203] The invention examples and comparative examples were prepared according to the above general process. After granulating the hydrophilic layer formulation and applying it to an aluminum-containing support that was etched and anodized two or three times, the infrared radiation-sensitive image recording layer was prepared as described above. Table V below identifies each of these examples.

[0204]

Table 5

[0205] Each of the above invention originals and comparative originals was evaluated for press life, on-press developability, ink-water balance (toning restart or RST test), and storage life using the following test methods, and the results of these evaluations are shown in Table VI below.

[0206] On-press developability (DOP): To evaluate on-press developability, each lithographic printing plate original (both invention and comparison) was exposed using a Trendsetter 800 III Quantum (available from Eastman Kodak Company) at 50 mJ / cm 2 ~300 mJ / cm 2Image-like exposures were performed in different energy segments between , and then mounted on a Heidelberg Speedmaster SM 74 printing press (available from Heidelberg) without any development process in between. In other words, each image-forming plate was developed on-press using this press, which was operated with Varn Supreme 6038 + Par dampening solution and OF Kodak Kreide black lithographic ink (Janecke + Schneemann Druckfarben GmbH). Each resulting lithographic plate was used for an on-press developability print test of up to 1000 prints. For the first 10 rotations, the press was operated with dampening solution only, and then lithographic ink was supplied to the lithographic plate and printing paper was fed into the machine. During the on-press development process, the unexposed areas of the infrared radiation-sensitive image recording layer first transferred the lithographic ink to the printing sheet. On-press developability was evaluated by counting the number of printed sheets required to obtain a clear background, and one of the following qualitative values ​​was given based on the number of printed sheets: (++) Development was completed with 5 sheets or less of paper; (+) Development was completed with more than 5 but no more than 10 photos; (0) Development was completed with more than 10 but no more than 15 images; (-) Development was completed with more than 15 but 30 or fewer photos; and (--)The development was completed with more than 30 sheets but less than or equal to 50 sheets of paper.

[0207] Shelf life: To evaluate the shelf life, the same image-like exposure conditions as described above for the on-press developability test were used, except that each lithographic printing plate (both the invention plate and the comparison plate) was subjected to accelerated degradation by being stored for 5 days at 40°C and 80% relative humidity after coating, prior to image-like exposure. Each plate was then imaged and used for printing on the printing press described above for the on-press developability printing test, with the same scoring as below: (++) Development was completed with 5 sheets or less of paper; (+) Development was completed with more than 5 but no more than 10 photos; (0) Development was completed with more than 10 but no more than 15 images; (-) Development was completed with more than 15 but 30 or fewer photos; and (--)The development was completed with more than 30 sheets but less than or equal to 50 sheets of paper.

[0208] Press lifespan: To evaluate the press life, each lithographic printing plate (both invention and comparison) was subjected to 120 mJ / cm². 2 The plates were image-likely exposed using a Trendsetter 800 III Quantum (available from Eastman Kodak Company) and then mounted on a Heidelberg Speedmaster SM 74 press (available from Heidelberg) without any intermediate development process. In other words, each image-forming plate was developed on-press using this press, which was operated with Varn Supreme 6038 + Par dampening solution and OF Kodak Kreide black lithographic ink (Janecke + Schneemann Druckfarben GmbH). Press life printing tests were performed with up to 150,000 prints using each obtained lithographic plate. As printing progressed, the lithographic plates gradually wore down. The press life of each lithographic plate was defined as the number of printed sheets achieved before the tonal value of the paper printed with a 50% FM20 screen fell below 70% of the tonal value obtained on the 1000th sheet. For measuring color values, a Techkon Spectro Densitometer was used, and the results were scored as follows: (++) Over 80,000 copies; (+) 60,000 to less than 80,000 sheets; (0) 40,000 or more but less than 60,000 sheets; (-)20,000 or more but less than 40,000; and (--) Less than 20,000 copies.

[0209] Resume toning (RST): To evaluate toning restart, the same exposure conditions described for the press life test were applied. Samples of each image-exposed lithographic plate (both invention and comparison) were mounted on a SpeedMaster SX 52 press and developed on-press using Bottcher fount S-3021 dampening solution and OF Kodak Kreide black lithographic ink (Janecke+Schneemann Druckfarben GmbH). After 3000 prints, the press was stopped without post-dampening. After 15 minutes, each lithographic plate was tested for toning restart (RST) without pre-dampening. For the toning restart test, the water content was manipulated near the bleeding limit to enhance the distinction in toning restart. Printed sheets were evaluated using a large scanner, and then the luminance of specific areas was analyzed. Non-image areas and a 20 μm checkerboard were analyzed. When the luminance of a specific area reached its maximum value, the plate was evaluated as clear, and the results were scored as follows: (++) Less than 20 sheets; (+)20 or more but less than 30 sheets; (0) 30 or more but less than 40 sheets; (-)40 sheets or more but less than 50 sheets; and (--) More than 50 sheets.

[0210] Table VI below shows the DOP, shelf life, press life, and RST test results for each embodiment of the invention and comparative embodiment, based on the evaluations specified above.

[0211] [Table 6]

[0212] The results indicate that (1) the compound and (2) one or more hydrophilic polymers must be used together to achieve overall improvements in several key characteristics of on-press developable lithographic printing plates, such as rapid DOP, good shelf life, long operating time, and good toning restart behavior. The best embodiment of the present invention provided improvements in multiple characteristics without unnecessarily reducing other characteristics.

Claims

1. A substrate having a surface, A radioactive image-forming layer that can be developed on press and disposed on the surface of the substrate, A lithographic printing plate original, The aforementioned substrate is An aluminum-containing plate having a granulated and etched surface; An inner aluminum oxide layer disposed on the granulated and etched surface, wherein the inner aluminum oxide layer has an average dry thickness (T) of at least 300 nm and 3000 nm or less. i ) has an average inner pore diameter (D) of 100 nm or less. i An inner aluminum oxide layer containing numerous inner micropores having; An outer aluminum oxide layer disposed on the inner aluminum oxide layer, wherein the outer aluminum oxide layer has an average outer micropore diameter (D) of at least 15 nm and 30 nm or less. o It includes numerous outer micropores having ) and an average dry thickness (T) of at least 30 nm and 650 nm or less. o Having an outer aluminum oxide layer; At least 0.0002 g / m³ 2 and 0.1 g / m 2 A hydrophilic layer disposed on the outer aluminum oxide layer with the following dry coverage: (1) Compounds having one or more ethylenically unsaturated polymerizable groups, one or more -OM groups in which at least one of the groups is directly bonded to a phosphorus atom, and a molecular weight of less than 2000 daltons / mol, where M represents a hydrogen, sodium, potassium, or aluminum atom; and (2) One or more hydrophilic polymers comprising repeating units, each comprising at least (a) a repeating unit comprising an amide group and (b) a repeating unit comprising an -OM' group directly bonded to a phosphorus atom, where M' represents a hydrogen, sodium, potassium, or aluminum atom. Includes, The (1) compound is present in an amount of at least 10% by weight and 80% by weight or less based on the total weight (solid) of the hydrophilic layer, or the weight ratio of one or more (1) compounds in the hydrophilic layer to one or more of the (2) hydrophilic polymers is 1:4 to 4:1, and A lithographic printing plate, including the original plate.

2. The outer aluminum oxide layer has at least 500 micropores / μm 2 and 3000 micropores / μm 2 and has the following micropore density (C o ), and has a porosity (P o ) of 0.3 or more and 0.8 or less, and P o is defined as 3.14 (C o )(D o 2 ) / 4000000, the original lithographic printing plate according to claim 1.

3. The outer aluminum oxide layer has an average dry thickness of at least 130 nm (T o ) and the outer aluminum oxide layer is directly disposed on the inner aluminum oxide layer; the average dry thickness (T) of the inner aluminum oxide layer i ) is at least 650 nm, and the average inner micropore diameter (D i ) is 15 nm or less, and the average outer pore diameter (D o A lithographic printing plate according to claim 1 or 2, which is less than )

4. The substrate further includes an intermediate aluminum oxide layer disposed between the inner aluminum oxide layer and the outer aluminum oxide layer, wherein the intermediate aluminum oxide layer has an average dry thickness (T) of at least 60 nm and 300 nm or less. m ) has an average intermediate micropore diameter (D) of at least 20 nm and 60 nm or less. m It contains numerous intermediate micropores having ) and D m However, D i Larger than D o Larger than the average dry thickness (T) of the outer aluminum oxide layer. o A lithographic printing plate according to any one of claims 1 to 3, wherein the n-f(n) is less than 150 nm.

5. The outer aluminum oxide layer is directly disposed on the inner aluminum oxide layer, and the average micropore size (D) of the inner aluminum oxide layer i The outer aluminum oxide layer has a minimum of 20 nm of fine pore size (D o A lithographic printing plate according to any one of claims 1 to 3, which is larger than )

6. (1) At least one ethylenically unsaturated polymerizable group in the compound is bonded to the phosphorus atom to which the -OM group is bonded, and the spacer group is of the formula -(-CH 2 CH 2 O-) p A lithographic printing plate according to any one of claims 1 to 5, represented by -, where the subscript p is at least an integer between 1 and 10.

7. A substrate having a surface, A radioactive image-forming layer that can be developed on press and disposed on the surface of the substrate, A lithographic printing plate original, The aforementioned substrate is An aluminum-containing plate having a granulated and etched surface; An inner aluminum oxide layer disposed on the granulated and etched surface, wherein the inner aluminum oxide layer has an average dry thickness (Ti) of at least 650 nm and 3000 nm or less, and contains a number of inner micropores having an average inner micropore diameter (Di) of 15 nm or less; An outer aluminum oxide layer disposed on the inner aluminum oxide layer, wherein the outer aluminum oxide layer includes a number of outer micropores having an average outer micropore diameter (Do) of at least 15 nm and 30 nm or less, has an average dry thickness (To) of at least 130 nm and 650 nm or less, and the average inner micropore diameter (Di) is less than the average outer micropore diameter (Do); A hydrophilic layer disposed on the outer aluminum oxide layer with a dry coverage of at least 0.0002 g / m² and 0.1 g / m² or less, (1) Compounds having one or more ethylenically unsaturated polymerizable groups, one or more -OM groups in which at least one of the groups is directly bonded to a phosphorus atom, and a molecular weight of less than 2000 daltons / mol, where M represents a hydrogen, sodium, potassium, or aluminum atom; and (2) One or more hydrophilic polymers comprising repeating units, each comprising at least (a) a repeating unit comprising an amide group and (b) a repeating unit comprising an -OM' group directly bonded to a phosphorus atom, where M' represents a hydrogen, sodium, potassium, or aluminum atom. A hydrophilic layer including A lithographic printing plate, including the original plate.

8. The lithographic printing plate according to any one of claims 1 to 7, wherein the on-press developable radiosensitive image-forming layer is of negative type, sensitive to infrared radiation, and comprises one or more infrared radiation absorbers.

9. A method for providing a lithographic printing plate, To form an image-like exposure image-forming layer having an exposed region and an unexposed region, a step of exposing a lithographic printing plate according to any one of claims 1 to 8 to image-like radiation, A method for forming a lithographic printing plate, comprising the step of removing the unexposed region from the image-like exposure image forming layer on a machine.

10. A method for preparing a lithographic printing plate according to any one of claims 1 to 8, wherein, in order, A step of preparing an aluminum-containing plate having an electrochemically or mechanically granulated and etched surface; A step of subjecting the aluminum-containing plate to a first anodizing process in order to form an outer aluminum oxide layer on the electrochemically or mechanically granulated and etched surface, wherein the outer aluminum oxide layer has an average outer micropore size (D) of at least 15 nm and 30 nm or less. o It includes numerous outer micropores having ) and an average dry thickness (T) of at least 30 nm and 650 nm or less. o ) a process having; The process of rinsing the outer aluminum oxide layer; A step of subjecting the aluminum-containing plate to a second anodizing process in order to form an inner aluminum oxide layer beneath the outer aluminum oxide layer, wherein the inner aluminum oxide layer has an average dry thickness (T) of at least 300 nm and 3000 nm or less. i ) has an average inner pore diameter (D) of 100 nm or less. i A process including a number of internal micropores having; A step of rinsing the outer aluminum oxide layer and the inner aluminum oxide layer; The step of forming an on-press developable radiosensitive image-forming layer on the outer aluminum oxide layer; After rinsing the outer aluminum oxide layer and the inner aluminum oxide layer, and before forming the on-press developable radiosensitive image forming layer on the outer aluminum oxide layer, a hydrophilic layer is prepared on the outer aluminum oxide layer, wherein the hydrophilic layer is (1) Compounds having one or more ethylenically unsaturated polymerizable groups, one or more -OM groups in which at least one of the groups is directly bonded to a phosphorus atom, and a molecular weight of less than 2000 daltons / mol, where M represents a hydrogen, sodium, potassium, or aluminum atom; and (2) comprising one or more hydrophilic polymers, each comprising a repeating unit having at least (a) an amide unit and (b) a repeating unit having an -OM' group directly bonded to a phosphorus atom, where M' represents a hydrogen, sodium, potassium, or aluminum atom. The hydrophilic layer has a density of at least 0.0002 g / m 2 and 0.1 g / m 2 A method comprising the step of arranging on the outer aluminum oxide layer with the following dry coverage.

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