WO2023071054A1

WO2023071054A1 - Photosensitive negative image type planographic printing plate precursor and lithographic printing plate platemaking method using same

Info

Publication number: WO2023071054A1
Application number: PCT/CN2022/084722
Authority: WO
Inventors: 翁银巧; 高邈; 徐能平; 应作挺; 常士旺; 潘枫; 马显瑶; 金剑臣; 陶烃
Original assignee: 浙江康尔达新材料股份有限公司
Priority date: 2021-10-26
Filing date: 2022-04-01
Publication date: 2023-05-04
Also published as: CN113954502A; CN113954502B

Abstract

Disclosed in the present invention are a photosensitive negative image type planographic printing plate precursor and a lithographic printing plate platemaking method using same. The planographic printing plate precursor comprises: (i) an aluminum plate substrate, a phosphate/fluoride-containing hydrophilic layer covering the surface of the aluminum plate substrate, and the hydrophilic layer containing the following components in parts by mass: 90-99.8 parts of phosphate and 0.2-10 parts of fluoride; and (ii) an imageable coating layer coating the surface of the hydrophilic layer of the aluminum plate substrate, the imageable coating layer containing the following imageable composition in parts by mass: 25-65 parts of a radical polymerizable compound, 0.5-25 parts of a photoinitiator, 10-60 parts of a binder, and 1-20 parts of a development accelerator. The platemaking method comprises the following steps: (1) exposing a planographic printing plate precursor according to a desired image by using a laser, so as to form an exposed region and an unexposed region; and (2) removing the unexposed region from the exposed printing plate precursor by means of a development process to obtain a desired planographic printing plate. The use of the imageable compositions and the platemaking method can implement a flexible development process of "on-press development" or "off-press development", and the obtained printing plate has excellent printing performance.

Description

A photosensitive negative-working lithographic printing plate precursor and a method for making a lithographic printing plate using the precursor

technical field

The invention belongs to the technical field of lithographic printing plate preparation, and in particular relates to a photosensitive negative-type lithographic printing plate precursor and other plate-making methods.

Background technique

The latest developments in the field of lithographic printing plates have benefited from the increasing popularity of digital technologies that process, store, and output image information electronically by computers. Various new image output methods corresponding to such digital technologies have become increasingly popular. Put it into practice. As a result, a computer-to-plate (CTP) technology in which digital image information can be loaded on highly converging radiation such as a laser, and the laser is used to directly scan and expose the original plate of the lithographic printing plate was born. This type of technology has attracted much attention due to the advantage of no longer using traditional film films to manufacture lithographic printing plates, and has become one of the important technical issues in the field of lithographic printing plates.

In the traditional manufacturing process of lithographic printing plates, it is necessary to dissolve and remove the unnecessary photosensitive coating by developer solution after exposure, which causes relatively time-consuming and increased cost. Especially in recent years, due to the consideration of environmental protection, the disposal of the waste liquid discharged along with the development treatment of strong alkaline solution has become a subject of great concern to the entire industry. Therefore, as a matter of pursuing further simplification of the plate-making process and reduction of waste water treatment, various new technologies, including printing plate precursors that can be on-press after exposure without chemical development or that can be off-press with a near-neutral aqueous solution The production process of image development has become a challenging subject of technical research in this field.

As one of the plate-making technologies that meet the above-mentioned challenges, a CTP printing plate precursor called "on-press development" or "process-free" and its plate-making method have been proposed. This lithographic printing plate precursor can The unexposed portions of the image-recording layer are removed by mechanical contact of on-press ink and/or fountain solution by a rotating cylinder to obtain a lithographic printing plate. The treatment-free CTP plate has obvious advantages in energy saving and emission reduction. First of all, the treatment-free CTP plate does not need to use chemical reagents for special treatment, which saves the high cost of washing and saves the cost of purchasing chemical reagents and related instruments. and maintenance costs. Secondly, the treatment-free CTP plate does not need to use chemical medicine to wash the plate, and there is one less processing procedure than the traditional CTP plate, which simplifies the production process, makes the operation easier, and saves production and preparation time.

Another solution to simplify the process and solve the problem of waste liquid is to use a near-neutral aqueous solution for development, also known as "low chemical processing" plate making method. Compared with the above-mentioned "processing-free" technology, the advantage of this method is that it can detect the quality of the image after exposure and before printing on the printing machine, and avoid contamination of the unexposed area caused by the influence of ambient light on the printing plate. EP1342568 discloses a method of making a thermally sensitive CTP lithographic printing plate, allowing a thermographic precursor comprising hydrophobic thermoplastic polymer particles which coalesce when heated to be developed with a protective colloid. EP 1751625 provides a method for making lithographic printing plates from photopolymer CTP printing plate precursors. The exposed plate is a simplified process in which developing and gumming occur simultaneously in a single bath with a protective gum. Since the unexposed areas on the photopolymer printing plate are removed by the gumming step, the exposed plate can be stored in ambient light for a long time before it is installed on the printing press, and before the printing plate is installed on the printing press Can provide visible images. In addition, treatment with protective glue provides better removal than on-press treatment with fountain solution and ink.

After decades of development in the field of CTP lithographic printing plates, two mainstream trends have been formed: thermosensitive and photosensitive. Thermal technology uses near-infrared (wavelength 830nm) laser imaging, while photosensitive technology uses ultraviolet and visible light (wavelength 380- 405nm) laser imaging. Chinese patent document CN106313870B discloses a method for preparing a heat-sensitive negative-working CTP lithographic printing plate. This patent document adopts the method of directly developing and imaging on a printing machine after exposure, or first going through low-chemical development and imaging after exposure, and then applying to a printing press to achieve instant The plate-making method of off-machine development and on-machine development can be realized at the same time, satisfying customers to choose a more practical method according to the actual situation.

At present, the market of chemical-free thermal CTP lithographic printing plates at home and abroad is expanding year by year, but chemical-free photosensitive lithographic printing plates are still limited to the low chemical treatment technology in the field of violet laser (Violet), while photosensitive non-processing lithographic printing plates are in the market. The development of ultraviolet light (UV) field is still blank. The "on-machine development" or "treatment-free" CTP lithographic printing plate in the photosensitive field has not yet been used in the market, and it is seriously behind the heat-sensitive CTP lithographic printing plate technology in the implementation of environmental protection plate making and the development of wastewater discharge control. Therefore, the research and development of chemical-free photosensitive CTP lithographic printing plates is an inevitable trend to adapt to green printing and energy-saving and environmental protection policies, and has very positive significance.

Compared with the heat-sensitive negative-working CTP lithographic printing plate, the ultraviolet light negative-working CTP lithographic printing plate requires less energy for exposure, and the design needs to improve the light for the imageable composition to change from hydrophilic to lipophilic. sensitivity. The present invention adopts polyfunctional urethanized acrylate or polyfunctional urethanized methacrylate containing high crosslink density, through diisocyanate, polyol, hydroxyethyl (meth)acrylate, etc. Condensation reaction of components to prepare free radical polymerizable compounds; use photoinitiators that can quickly produce free radical crosslinking under ultraviolet light radiation and development accelerators with high tolerance to improve photosensitive speed and imaging function; hydrophilic on the substrate The main component of the coating is selected from materials containing phosphate/fluoride, which makes the combination of the photosensitive layer and the base of the digital printing plate more firm after being scanned by the photosensitive plate-making machine, and improves the printing durability and exposure speed of the printing plate. So as to achieve a breakthrough in the technology of ultraviolet light negative pattern free CTP lithographic printing plate.

Contents of the invention

Therefore, the technical problem to be solved by the present invention is to overcome the large amount of corrosive developer produced in the plate-making process of photosensitive CTP lithographic printing plates, and solve the single defect of the actual developing process, thereby providing a kind of "off-machine developing" and can be used. The flexible development process of "on-machine development" realizes the photosensitive CTP lithographic printing plate precursor and its plate-making method that meet the actual needs of customers.

A photosensitive negative-working lithographic printing plate precursor provided by the present invention comprises: (i) an aluminum plate substrate covered with a phosphate/fluoride-containing hydrophilic layer on its surface; (ii) An imageable coating is coated on the surface of the hydrophilic layer of the aluminum base.

Wherein, the phosphate/fluoride hydrophilic layer comprises the following components in parts by mass:

Phosphate 90-99.9 parts

Fluoride 0.1-10 parts

Described imageable coating comprises the imageable composition of following mass parts:

25-65 parts of free radical polymerizable compound,

0.5-25 parts of photoinitiator,

10-60 parts of binder,

1-20 parts of developing accelerator.

The lithographic printing plate precursor is sensitive to radiation in the wavelength range of 350nm-450nm.

The aluminum plate base is preferably an aluminum support that is electrochemically ground and anodized with sulfuric acid.

The phosphate in the phosphate/fluoride hydrophilic layer is one or more of alkali metal phosphate, alkali metal hydrogen phosphate, and alkali metal dihydrogen phosphate; the fluoride is alkali metal fluoride Salt, alkali metal fluorophosphate, alkali metal fluoroaluminate, alkali metal fluorotantalate, alkali metal fluoroantimonate, alkali metal fluorozirconate, alkali metal fluoroarsenate, alkali metal fluoroborate one or more of .

Preferably, the phosphate is one or more of potassium dihydrogen phosphate and sodium dihydrogen phosphate; the fluoride is potassium fluoride, sodium fluoride, potassium fluoroaluminate, sodium fluoroaluminate one or more of .

The radical polymerizable compound is a polymerizable monomer and/or oligomer containing at least one ethylenically unsaturated double bond;

The photoinitiator has one or more absorption peaks or absorption shoulders in the UV-violet range;

The binder is a carbon-containing polymer in the main chain;

The development accelerator is a low molecular weight hydrophilic organic compound or a high molecular weight hydrophilic polymer.

Preferably, the polymerized monomer and/or oligomer is acrylate, methacrylate, urethane acrylate, urethane methacrylate, epoxy acrylate or epoxy methacrylate, poly One or more of alcohol acrylates, polyol methacrylates, urethane acrylates, urethane methacrylates, polyether acrylates, and polyether methacrylates.

Preferably, the photoinitiator is one of onium salt, trihalomethyl compound, carbonyl compound, azide compound, coumarin, ketocoumarin, anthraquinone, organoboron compound, oxime ester or phosphine oxide one or more species.

Preferably, the carbon-containing polymer in the main chain is acrylic acid, methacrylic acid, acrylate, methacrylate, acrylamide, methacrylamide, styrene and styrene derivatives, acrylonitrile, methacrylonitrile A polymer derived from at least one of N-substituted cyclic imides and maleic anhydride as repeating units.

Preferably, the average molecular weight of the carbon-containing polymer in the main chain is 5,000-100,000.

Preferably, the low-molecular-weight hydrophilic organic compound used as a developing accelerator is polyhydric alcohol and their ether or ester derivatives, organic amine and their salt, organic sulfonic acid and their salt; The high molecular weight hydrophilic polymers of the accelerator are polyethylene glycol, gum arabic, starch, cellulose, dextrin, polysaccharide, and those containing carboxyl, sulfonic acid, phosphonic acid, amide, vinylpyrrolidone One or more of homopolymers or copolymers.

The present invention also provides a method for making a photosensitive negative-working lithographic printing plate, comprising the following steps:

(1) pattern exposure of a photosensitive negative-working lithographic printing plate precursor, thereby forming exposed areas and unexposed areas;

(2) Remove the unexposed area from the exposed printing plate precursor through a development process to obtain the desired lithographic printing plate. The development process is any one of the following: (i) on-machine development: using a dampening solution and/or lithographic inks are developed on-press; (ii) off-press development: development is performed in a processor off-press using a developer solution.

Wherein, the photosensitive negative-working lithographic printing plate precursor comprises: (i) an aluminum plate substrate covered with a phosphate/fluoride-containing hydrophilic layer on its surface; (ii) An imageable coating is applied to the surface of the hydrophilic layer of the plate base.

Phosphate 90-99.9 parts

Fluoride 0.1-10 parts

25-65 parts of free radical polymerizable compound,

0.5-25 parts of photoinitiator,

10-60 parts of binder,

1-20 parts of developing accelerator.

Wherein, the free radical polymerizable compound is a polymerizable monomer and/or oligomer containing at least one ethylenically unsaturated double bond;

The binder is a carbon-containing polymer in the main chain;

The developing solution used for off-machine development in the plate-making method contains carbonate and/or bicarbonate, and the mass fraction of carbonate and/or bicarbonate in the developing solution is 1-20%, The developer has a pH of 6-11.

Preferably, the carbonate in the developing solution is an alkali metal carbonate; the bicarbonate in the developing solution is an alkali metal bicarbonate.

Further, the alkali metal carbonate is at least one of sodium carbonate, potassium carbonate or lithium carbonate;

The alkali metal bicarbonate is at least one of sodium bicarbonate, potassium bicarbonate or lithium bicarbonate.

Further, the developing solution further includes at least one of surfactant and/or water-soluble polymer compound.

The mass concentration of the surfactant in the developing solution is 0.1-10%;

The mass concentration of the water-soluble polymer compound in the developing solution is 0.1-20%;

The pH value of the developer is preferably 7-10.

In the step (2), before the developing process, a step of preheating the exposed printing plate precursor is also included.

Further, the imageable coating may comprise one or more layers.

The present invention also provides a photosensitive negative-working lithographic printing plate produced by the above-mentioned plate-making method.

Compared with the prior art, the technical solution of the present invention has the following advantages:

1) For the photosensitive negative-working lithographic printing plate precursor provided by the present invention, by regulating the type and content of each component in the aluminum base and the imageable coating, the hydrophilic coating on the base contains phosphate/fluorine The compound material makes the combination of the photosensitive layer and the plate base more firmly after the digital printing plate is scanned by the photosensitive plate-making machine. It adopts multi-functional carbamate-based (meth)acrylate with high cross-linking density, and is selected in the ultraviolet Photoinitiators that can quickly produce free radical crosslinking under light radiation and high-tolerance development accelerators to increase the speed of exposure light and imaging functions, and realize a more environmentally friendly and safer CTP lithographic printing plate-making process in the photosensitive field. Effectively adapt to a variety of development processes, thereby ensuring that customers can flexibly choose development processes according to actual needs, such as "off-machine development" and "on-machine development", and choosing different development processes will not damage the final development effect.

2) In the plate-making method of the photosensitive negative-working lithographic printing plate provided by the present invention, the developer selected in the off-machine development process mainly contains carbonate and bicarbonate, does not contain highly corrosive alkaline substances, and reduces waste. discharge of liquid; and carbonate ions and bicarbonate ions, exhibit a buffer effect and can prevent fluctuations in pH even when the developer is used for a long time. Therefore, deterioration of developing performance caused by fluctuations in pH, occurrence of development scum, and the like are suppressed.

Detailed ways

In order to better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments. This invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete and will fully convey the concept of the invention to those skilled in the art, and the present invention will only be defined by the appended claims.

The term "off-press development" in the present invention refers to the step of removing the image-recording layer of a lithographic printing plate precursor by contact with a liquid (usually a developer solution) in a device (usually an automatic plate processor), The surface of the hydrophilic substrate is thus exposed; the term "on-press development" refers to the step of removing the image-recording layer of a lithographic printing plate precursor by contact with ink and/or fountain solution on-press, thereby exposing The surface of a hydrophilic substrate; the term "treatment-free" refers to a process of platemaking that does not require any mechanical or chemical treatment after exposure and prior to printing, unless otherwise specified.

Hereinafter, the CTP lithographic printing plate precursor and its plate-making method of the present invention will be described in detail. First, after describing the development process which is the most characteristic step, other steps will be described.

, Developing process:

The plate-making method of the lithographic printing plate of the present invention comprises: with or without a preheating step, the said exposed printing plate precursor is removed through a developing process to remove the said unexposed area, said developing process is as follows Any one of: (i) on-machine development: use fountain solution and/or lithographic printing ink to carry out the development process on the printing press; (ii) off-machine development: use neutral or weakly alkaline developer to print The developing process is carried out in a plate processor outside the machine, and the developing solution includes carbonate and/or bicarbonate.

a. On-machine development:

The printing plate precursors of the present invention are "on-press developable", i.e., the printing plate precursors are mounted directly on the printing press and the plate cylinders are rotated while fountain solution and/or ink are supplied to the printing plate precursors on the imageable coating. The non-exposed areas of the imageable coating are removed from the support after a number of revolutions of the plate cylinder, preferably less than 50 revolutions, by passing a suitable fountain solution, lithographic ink, or a combination of both during printing in any order Unexposed areas of the imageable coating are removed.

In a preferred embodiment, only the fountain solution is supplied to the printing plate when the printing press is first started, and then after a few revolutions of the apparatus, the ink is supplied.

In another alternative embodiment, the supply of fountain solution and ink can be started at the same time when the printing press is first started, or only the ink can be supplied to the printing plate at the beginning, and then after a few revolutions of the equipment, it can be started. Start supplying fountain solution.

In yet another alternative embodiment, a single fluid ink may be supplied to the plate for on-press processing. Single-fluid inks consist of an ink phase (also known as a hydrophobic or lipophilic phase) and a polar phase, which replaces the aqueous fountain solution used in conventional offset printing. Examples of suitable single fluid inks are described in US Patent 4,045,232; US Patent 4,981,517 and US Patent 6,140,392. In a most preferred embodiment, the single fluid ink comprises an ink phase and a polyol phase as described in WO 00/32705.

This type of development process avoids the use of traditional alkaline developers and the use of separate development equipment.

, Off-camera development:

The off-machine developing process of the present invention is not particularly limited, and it may be developed by a known method. Development can be accomplished using so-called "manual" development, "immersion" development, or processing with automatic development equipment (usually a processor). In the case of "manual" development, development is performed by abrading the entire imaged element with a sponge or cotton pad thoroughly soaked with a suitable developer (described below), followed by rinsing with water. "Dip" development involves immersing the imaged element in an agitated tank or pan containing a suitable developer for 10-60 seconds (especially 20-40 seconds), followed by rinsing with water, with or without a sponge or Cotton pad sanding. The application of automatic developing equipment is well known and generally involves pumping developer into a developing tank and spraying it from spray nozzles. The imaged element is contacted with the developer in a suitable manner. The apparatus may also include suitable sanding means such as brushes or rollers and a suitable number of delivery rollers. Some developing equipment includes a laser exposure device and the equipment is divided into an imaging section and a developing section. For example, the processing solution (or developer) can be applied to the imaged element by grinding, spraying, jetting, dipping, immersing, slot die coating (see, e.g., U.S. Patent 6,478 to Maruyama et al., Figures 1 and 2 of 483) or reverse roll coating (as described in Figure 4 of Kurui et al. US Pat. break pad or applicator contact. For example, the imaging element can be brushed with the rinse solution, or it can be poured onto the imaging surface or spray nozzle systems such as those described in EP 1,788,431 and U.S. Patent 6,992,688 (Shimazu et al.) The imaged surface is developed by spraying with force sufficient to remove the unexposed areas. Likewise, the imaged element can be dipped in a processing solution and abraded manually or with equipment.

Suitable off-press development equipment has at least one roller for sanding or brushing the imaged element while applying the developer solution. By using such a processing device, it is possible to more completely and rapidly remove the unexposed areas of the imaging layer of the printing plate. Residual developer can be removed (eg, using a squeegee or roller) or left on the resulting printing plate without any rinsing steps. Excess developer can be collected in the tank and used several times, replenished if necessary from the reservoir. The developer replenisher can be of the same concentration as the developer used in processing, or it can be provided in concentrated form and diluted with water at an appropriate time. The developing process may always use fresh liquid, but it is preferable to circulate the developing liquid after the developing process through a filter so as to be reused. As the filter for filtering the developing solution used in the above-mentioned developing step, any filter can be used as long as it can filter foreign matter mixed in the developing solution. As the material of the filter, polyester resin, polypropylene resin, polyethylene resin, cellulose resin, cotton, and the like are preferably used. The mesh diameter of the filter is preferably 5 to 500 μm, more preferably 10 to 200 μm, and still more preferably 20 to 100 μm.

The off-machine developing step of the present invention is preferably carried out by an automatic processor equipped with a rubbing member, wherein the image-exposed lithographic printing plate precursor is rubbed while being transported; such as U.S. Patent Nos. 5,148,746 and 5,568, 768 and British Patent 2,297,719 are particularly preferred automatic processors that use a rotating brush roller as the friction member. As the rotary brush roller, a known rotary brush roller manufactured by inserting a brush material in a plastic or metal roller can be used. As a material for the brush, plastic fibers (e.g. polyester-based, e.g. polyethylene terephthalate or polybutylene terephthalate, polyamide-based, e.g. nylon 6.6 or nylon 6.10) can be used. , polyacrylic bases, such as polyacrylonitrile or polyalkyl(meth)acrylates, and polyolefinic bases, such as polypropylene or polystyrene). For example, a brush material having a fiber bristle diameter of 20 to 400 μm and a bristle length of 5 to 30 mm can be preferably used. The outer diameter of the rotating brush roller is preferably 30 to 200 mm, and the peripheral speed of the brush on the rubbing plate is preferably 0.1 to 5 m/sec.

The direction of rotation of the rotating brush rollers may be the same direction or the opposite direction with respect to the conveying direction of the lithographic printing plate precursor, but when two or more rotating brush rollers are used, it is preferable that at least one of them rotates relative to the conveying direction. The brushrolls rotate in the same direction, while at least one rotating brushroll rotates in the opposite direction. With such a configuration, the non-image area of the photosensitive layer is more stably removed.

In the plate-making method of the planographic printing plate of the present invention, can adopt conventional three-bath development system,

The three-bath development system is a method for sequentially performing the three processing steps of the off-machine developing step, the water washing step, and the gluing step, and the processing solutions in the respective baths are used to carry out the respective processing steps, that is, the developing process with at least three processing baths. system. In the plate-making method of the lithographic printing plate of the present invention, the water washing step and the gumming step are not performed before and after the above-mentioned off-machine developing step, and only the developing step using the above-mentioned developing solution is used as a processing step, that is, a single processing bath is required. (also known as single-bath processing).

After off-press development processing, the resulting lithographic printing plate can be placed on a cylinder of a printing press and printed by applying ink and fountain solution to the printing side of the imaged and developed element.

In addition, in this invention, you may provide a drying process arbitrarily after a developing process. In particular, it is preferable to install it in the last process of an automatic processing machine.

Developer:

The developing solution used in the plate-making method of the lithographic printing plate of the present invention is a neutral or slightly alkaline aqueous solution or aqueous dispersion containing at least carbonate, bicarbonate or a combination of both. In view of the presence of carbonate ions and bicarbonate ions, a buffer effect is exhibited and fluctuations in pH can be prevented even when the developer is used for a long time. Therefore, deterioration of developing performance caused by fluctuations in pH, occurrence of development scum, and the like are suppressed. In order to have both carbonate ions and bicarbonate ions present in the developer, the present invention preferably uses a combination of carbonate and bicarbonate, or carbonic acid can be generated by adding carbonate to the developer and subsequently adjusting the pH ions and bicarbonate ions. The carbonate or bicarbonate used is not particularly limited, and alkali metal salts thereof are preferred. As alkali metal salts, lithium carbonate, lithium bicarbonate, sodium carbonate, sodium bicarbonate, potassium carbonate, and potassium bicarbonate are exemplified; sodium carbonate, sodium bicarbonate, potassium carbonate, and potassium bicarbonate are preferred, and sodium carbonate and sodium hydrogen. The alkali metal salts may be used alone or in combination of two or more thereof.

The total amount of carbonate and bicarbonate is preferably 1 to 20% by weight, more preferably 3 to 15% by weight, based on the weight of the developing aqueous solution.

The developer solution of the present invention may also contain a surfactant (eg, anionic, nonionic, cationic or amphoteric surfactant).

Examples of anionic surfactants include ricinoleate (aliphates), rosin esters, hydroxyalkane sulfonates, alkane sulfonates, dialkyl sulfosuccinates, linear alkylbenzene sulfonates, branched Salts of alkylbenzene sulfonates, alkylnaphthalene sulfonates, alkylphenoxypolyoxyethylene propylsulfonates, polyoxyethylene alkylsulfophenyl ethers, N-methyl-N-oil Sodium Taurate, Disodium Monoamide N-Alkyl Sulfosuccinate, Petroleum Sulfonate, Sulfated Castor Oil, Sulfated Tallow, Sulfate Salts of Aliphatic Alkyl Esters, Salts of Alkyl Sulfates , sulfate esters of polyoxyethylene alkyl ethers, sulfate ester salts of aliphatic monoglycerides, sulfate ester salts of polyoxyethylene alkylphenyl ethers, sulfate ester salts of polyoxyethylene styrylphenyl ethers, alkyl Salts of phosphoesters, phosphoester salts of polyoxyethylene alkyl ethers, phosphoester salts of polyoxyethylene alkylphenyl ethers, partially saponified compounds of styrene-maleic anhydride copolymers, olefin-maleic anhydride copolymers Partially saponified compound, and naphthalenesulfonate formalin condensate. Among these anionic surfactants, particularly preferred are dialkyl sulfosuccinates and alkylnaphthalene sulfonates.

Specific examples of suitable anionic surfactants include sodium salts of alkylated naphthalenesulfonates, disodium methylene-binaphthalene-disulfonates, sodium alkylbenzenesulfonates, alkylphenoxybenzenedisulfonates sodium sulfonate, sulfonated alkyl-diphenyl ether, ammonium or potassium perfluoroalkyl sulfonate and sodium dioctyl-sulfosuccinate.

Suitable examples of nonionic surfactants include polyoxyethylene alkyl ethers, polyoxyethylene alkyl aryl ethers, where the aryl group can be phenyl, naphthyl or aromatic heterocyclic groups, polyoxyethylene polystyrene Phenyl ether, polyoxyethylene polyoxypropylene alkyl ether, polyoxyethylene polyoxypropylene block polymer, partial ester of glycerol fatty acid, partial ester of sorbitan fatty acid, partial ester of pentaerythritol fatty acid Esters, Propylene glycol mono fatty acid esters, Partial esters of sucrose fatty acids, Partial esters of polyoxyethylene sorbitan fatty acids, Partial esters of polyoxyethylene sorbitan fatty acids, Polyethylene glycol fatty esters, Partial esters of polyglycerol fatty acids, polyoxyethylated castor oil, partial esters of polyoxyethylene glycerol fatty acids, fatty diethanolamides, N,N-bis-2-hydroxyalkylamines, polyoxyethylene Alkylamines, triethanolamine fatty esters, and trialkylamine oxides. Among these nonionic surfactants, particularly preferred are polyoxyethylene alkylphenyl ethers, polyoxyethylene alkylnaphthyl ethers and polyoxyethylene-polyoxypropylene block polymers.

Specific examples of suitable nonionic surfactants include ethylene oxide adducts of sorbitol and/or sorbitan fatty acid esters, polypropylene glycol ethylene oxide adducts, dimethylsiloxane-ethylene oxide alkane block copolymers, dimethylsiloxane-(propylene oxide-ethylene oxide) block copolymers, and fatty acid esters of polyols.

The cationic surfactant is not particularly limited, and conventionally known cationic surfactants can be used. For example, alkylamine salts, quaternary ammonium salts, polyoxyethylene alkylamine salts and polyethylene polyamine derivatives.

The amphoteric surfactant usable in the present invention is not particularly limited, and conventionally known amphoteric surfactants can be used. Examples thereof include amino acid-based, betaine-based, and amine oxide-based amphoteric surfactants.

In addition, ethylene oxide adducts of acetylenic diols or acetylenic alcohols, or fluorine-based, silicon-based, and other surfactants can also be used.

Two or more of the above surfactants may be used in combination. For example, a combination of two or more different anionic surfactants or a combination of anionic surfactants and nonionic surfactants may be preferred. The amount of such a surfactant is not particularly limited, but is preferably 0.1 to 10% by weight, more preferably 0.1 to 5% by weight.

The developer solution of the present invention may also contain a water-soluble polymer compound, exemplified by soybean polysaccharide, modified starch, gum arabic, dextrin, cellulose derivatives (for example, carboxymethyl cellulose, carboxyethyl cellulose or methyl Cellulose) and its modified products, pullulan, polyvinyl alcohol and its derivatives, polyvinylpyrrolidone, polyacrylamide, acrylamide copolymer, vinyl methyl ether/maleic anhydride copolymer, vinyl acetate /maleic anhydride copolymer, styrene/maleic anhydride copolymer, etc.

Among the water-soluble polymer compounds, soybean polysaccharide, modified starch, gum arabic, dextrin, carboxymethylcellulose, polyvinyl alcohol and the like are particularly preferable.

The water-soluble polymer compounds may be used in combination of two or more. The content of the water-soluble polymer compound in the developer is preferably 0.1 to 20% by weight, more preferably 0.5 to 10% by weight.

The developer in the present invention may contain defoamers, organic acids, inorganic acids, inorganic salts and the like in addition to the above-mentioned components.

As the antifoaming agent, it is preferable to use a conventional silicone-based self-emulsifying type or emulsifying type antifoaming agent, and it is preferable to use a silicone antifoaming agent. Any of emulsification dispersion type, dissolution type, etc. may be used. The content of the antifoaming agent is preferably 0.001 to 1.0% by weight.

As the organic acid, ethylenediaminetetraacetic acid, citric acid, acetic acid, oxalic acid, malonic acid, salicylic acid, octanoic acid, tartaric acid, malic acid, lactic acid, levulinic acid, p-toluenesulfonic acid, xylenesulfonic acid, Phytic acid, organic phosphonic acid, etc. Organic acids can also be used in the form of alkali metal or ammonium salts, such as disodium ethylenediaminetetraacetic acid. The content of the organic acid is preferably 0.1 to 5% by weight.

As the inorganic acid or inorganic salt, there are exemplified phosphoric acid, metaphosphoric acid, ammonium dihydrogen phosphate, diammonium hydrogen phosphate, sodium dihydrogen phosphate, disodium hydrogen phosphate, potassium dihydrogen phosphate, dipotassium hydrogen phosphate, sodium tripolyphosphate, pyrophosphate Potassium phosphate, sodium hexametaphosphate, magnesium nitrate, sodium nitrate, potassium nitrate, ammonium nitrate, sodium sulfate, potassium sulfate, ammonium sulfate, sodium sulfite, ammonium sulfite, sodium bisulfate, nickel sulfate, etc. The content of the inorganic salt is preferably 0.1 to 5% by weight.

The pH of the developer in the present invention is not particularly limited as long as it is a pH exhibiting a buffering effect, and is preferably in the range of 6 to 11. And it is particularly preferably in the range of 7 to 10.

Printing plate precursors:

The lithographic printing plate precursor used in the present invention is characterized in that it has a negative-type image forming ability, that is, the region after the image exposure is cured to form an image part, and the unexposed part is removed by the development treatment as described above, Thus, a non-image portion is formed.

Base:

The substrate used in the lithographic printing plate precursor of the present invention is composed of an aluminum plate support, and its production method includes grinding and roughening by physical (mechanical) grinding, electrochemical grinding or chemical grinding, followed by acidic Anodized for treatment. The preferred hydrophilic lithographic printing plate substrate of the present invention is an electrochemically grained and sulfuric acid anodized aluminum plate support.

Sulfuric acid anodization of aluminum supports typically produces 1.5-5 g/m ² , more usually 2.5-4 g/m ² oxide (coverage) on the aluminum surface. When anodized with sulfuric acid, higher oxide weights (at least 3 g/m ² ) can provide longer print life.

The anodized aluminum plate support can be further coated with a phosphate/fluoride containing material to improve hydrophilicity. The present invention preferably covers a hydrophilic layer containing sodium dihydrogen phosphate and sodium fluoride, wherein the hydrophilic layer comprises the following components in parts by mass: 90-99.9 parts of sodium dihydrogen phosphate and 0.1 parts of sodium fluoride -10 copies.

The thickness of the substrate can vary but should be sufficient to withstand the wear and tear of printing and flexible enough to be rolled. Commonly used thicknesses are 0.1 mm up to and including 0.7 mm treated aluminum foil.

In addition, the base substrate can also be a cylindrical surface having an imageable layer thereon, such as part of a printing press. The use of such an imaging cylinder has been described in US Patent 5,713,287 (Gelbart).

Imageable Coatings:

The imageable coatings of the present invention comprise at least an imageable composition of a free radical polymerizable compound, a photoinitiator, a binder, and a development accelerator. In addition, in the present invention, "coating an imageable coating on the surface of the hydrophilic layer of the aluminum plate base" means that the coating of the radiation-sensitive composition can be placed on the base in a direct contact manner, or can be Arrangement of other layers between the substrate and the radiation-sensitive coating or on top of the radiation-sensitive coating does not negate any layers, such as protective layers, undercoats, intermediate layers, backcoats, etc., which are arranged as desired in the lithographic printing plate precursor The presence.

Free Radical Polymerizable Compounds :

Free radically polymerizable compounds are well known to those skilled in the art and have been described in considerable literature, including: "Photoreactive Polymers: The Science and Technology of Resists", A. Reiser, Wiley, New York, 1989, 102- 177 pages, B.M. Monroe; "Radiation Curing: Science and Technology", S.P. Pappas, Ed., Plenum, New York, 1992, 399-440 pages; "Polymer Imaging", A.B. Cohen and P. Walker; "Imaging Processes a Material ", I.M. Sturge et al., Van Nostrand Reinhold, New York, 1989, pp. 226-262. Additionally, useful free radically polymerizable components are also described in European Patent 1,182,033 (Fujimaki et al.).

According to the invention, the radically polymerizable compound is a polymerized monomer or oligomer containing at least one ethylenically unsaturated double bond, which may preferably be selected from the group consisting of acrylates of polyols, methacrylates of polyols, urethane acrylates, One or more of urethane methacrylate, epoxy acrylate, epoxy methacrylate, polyurethane acrylate, polyurethane methacrylate, polyether acrylate, polyether methacrylate.

Suitable free radically polymerizable monomers may include, for example, polyfunctional acrylate monomers or polyfunctional methacrylate monomers (e.g., ethylene glycol, trimethylolpropane, pentaerythritol, ethoxylated ethylene glycol, Ethoxylated Trimethylolpropane Acrylate, Ethoxylated Trimethylolpropane Methacrylate, Multifunctional Urethane Acrylate, Multifunctional Urethane acrylates, epoxidized acrylates, and epoxidized methacrylates), and oligomeric amine diacrylates. In addition to acrylate groups, methacrylate groups, acrylic monomers or methacrylic monomers may also have further double bonds or epoxide groups. The acrylic or methacrylic monomers may also contain acid (eg carboxylic acid) or base (eg amine) functionality. Useful free radically polymerizable compounds include multifunctional urethane acrylates, urethane acrylates, pentaerythritol tetraacrylate, and other polymerizable monomers apparent to those skilled in the art.

The free radically polymerizable component is present in the composition in an amount sufficient to render the UV radiation sensitive composition insoluble in the aqueous developer after radiation exposure. This is generally 25-65% by weight, usually 30-60% by weight, based on the dry weight of the radiation-sensitive composition.

Photoinitiator :

The free radical photoinitiators used in the present invention exhibit one or more absorption bands in the UV-violet range, and at least one of these bands extends into the visible range of the electromagnetic spectrum shown, or in the visible The range has a shoulder or one or more other minor bands. For example, one or more of onium salts, trihalomethyl compounds, carbonyl compounds, azide compounds, coumarins, ketocoumarins, anthraquinones, organoboron compounds, oxime esters or phosphine oxides.

Suitable onium salts include sulfonium salts, oxysulfoxide onium salts, oxonium salts, sulfoxide onium salts, phosphonium salts, diazonium salts, halonium salts such as iodonium salts. Specific examples include diphenyliodonium chloride, diphenyliodonium hexafluorophosphate, (4-methylphenyl)[4-(2-methylpropyl)-phenyl]iodonium hexafluorophosphate, hexafluorophosphate Bis(4-tert-butylphenyl)iodonium fluorophosphate, diphenyliodonium hexafluoroantimonate, diphenyliodonium octylsulfate, diphenyliodonium octylthiosulfate, diphenyliodonium 2-carboxylate Phenyliodonium, N-methoxy-a-methylpyridinium p-toluenesulfonate, 4-methoxybenzene-diazonium tetrafluoroborate, 2-cyanoethyl-triphenylphosphonium chloride , bis-[4-diphenylsulfonium phenyl] sulfide hexafluorophosphate, bis-4-dodecylphenyl iodonium hexafluoroantimonate, triphenylsulfonium hexafluoroantimonate, tetrafluoro Triphenylsulfonium borate, triphenylsulfonium octylsulfate, phenoxyphenyl diazonium hexafluoroantimonate, and anilinophenyl diazonium hexafluoroantimonate.

Photoinitiators also include trichloromethyltriazine-type initiation systems, as described in U.S. Patent 4,997,745; diaryliodonium salts and photosensitizers, as described in U.S. Patent 5,546,258; spectral sensitizers for visible light activation and Trichloromethyltriazines, as described in U.S. Patent No. 5,599,650; 3-ketocoumarins and polycarboxylic acid co-initiators for UV and visible light activation, such as anilino-N,N-diacetic acid and Dicoinitiators, as described in U.S. Patent No. 5,942,372; cyanine dyes, diaryliodonium salts, and carboxylic acid groups having a methylene group attached to an N, O, or S group directly attached to an aromatic ring. Coinitiators, as described in US Patent No. 5,368,990. Suitable free radical initiators include, for example, 2-(4-methoxyphenyl)-4,6-bis(trichloromethyl)-2-triazine, 2-(4-methoxy-1-naphthalene base)-4,6-bis(trichloromethyl)-1,3,5-triazine, anilino-N,N-diacetic acid, 2,2-dimethoxy-2-phenylethylphthalein , 2-methyl-l-[4-(methylthio)phenyl-2-morpholinopropan-l-one, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, 3-Benzoyl-7-methoxycoumarin, ketone coumarin 93, benzylethanolone or alkyl substituted anthraquinone, tert-butylammonium butyl borate triphenyl and triphenyl (n-butyl ) Tetraethylammonium borate.

The initiator composition comprising one or more initiator compounds is present in the radiation-sensitive composition in an amount of 0.5-25%, preferably at least 1% and up to and including 20%, based on the radiation-sensitive composition The total solids of the article or the dry weight of the coated imageable layer.

Binder :

The binder of the present invention is a polymer containing carbon in the main chain, and any one or any of binder polymers known in the art to be used in the photosensitive layer of a negative-working lithographic printing plate precursor can be used without limitation. Two or more.

Useful polymeric binders may be homogeneous, i.e. dissolved in the coating solvent, or may be present as discrete particles and include, but are not limited to, acrylic acid, methacrylic acid, acrylate-derived polymers, methacrylate-derived polymers, polyvinyl acetals, phenolic resins, polymers derived from styrene and its derivatives, acrylonitrile, methacrylonitrile, N-substituted cyclic imides or maleic anhydride, such as Those described in European Patent 1,182,033 (noted above) and US Patent 6,309,792 (noted above), US Patent 6,569,603 (noted above) and US Patent 6,893,797 (Munnelly et al.). Also useful are the vinyl carbazole polymers described in US Patent 7,175,949 (Tao et al.).

Alternatively, useful polymeric binders are particulate polymers that are distributed (usually uniformly) throughout the imageable layer. These polymers have an average particle size in the range of 10-10,000 nm (usually 20-800 nm) in particle diameter. Usually the polymeric binder is solid at room temperature and is typically a non-elastomeric thermoplastic. The polymeric binder contains both hydrophilic and hydrophobic regions, which are believed to be important for enhancing the difference between exposed and unexposed areas by promoting developability, the presence of the discrete particles tending to promote the unexposed areas. Developing ability. Specific examples of polymeric binders of this embodiment are described in U.S. Patent 6,899,994 (noted above), WO2009/030279 (Andriessen et al.), U.S. Patent 7,261,998 (Hayashi et al.), U.S. Pat. Patent 7,659,046 (Munnelly et al.) and European Patent 1,614,540 (Vermeersch et al.)

In addition to the polymeric binders of the above embodiments, the imageable layer may optionally contain one or more co-binders. Typical co-binders are, for example, cellulose derivatives, polyvinyl alcohol, polyacrylic acid, polymethacrylic acid, polyvinylpyrrolidone, polylactide, polyvinylphosphonic acid, synthetic copolymers such as alkoxy Polyethylene glycol acrylate copolymer, alkoxy polyethylene glycol methacrylate copolymer.

Polymers used as binders typically have an average molecular weight of 2,000-500,000, preferably 5,000-100,000. The total amount of all binder polymers used is usually 10-60% by weight, preferably 20-60% by weight, relative to the total weight of the non-volatile components of the composition.

Development Accelerator :

In order to allow the imageable coating to achieve the effects of "off-machine development" and "on-machine development" at the same time, the development accelerator used in the imageable coating of the present invention is a low-molecular-weight hydrophilic organic compound or a high-molecular-weight hydrophilic organic compound. permanent polymer.

The low-molecular-weight hydrophilic organic compound used as a development accelerator is one or more of polyhydric alcohols and their ether or ester derivatives, organic amines and their salts, organic sulfonic acids and their salts. Examples include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol and tripropylene glycol, glycerin, pentaerythritol and tris(2-hydroxyethyl)isocyanurate, triethanolamine, diethanolamine and Monoethanolamine, toluenesulfonic acid, sodium dodecylbenzenesulfonate, sodium dibutylnaphthalenesulfonate, sodium dioctylsuccinatesulfonate,

10L-45, emulsifier OS,

3B2,

ABL.

The high-molecular-weight hydrophilic polymer used as a development accelerator is polyethylene glycol, gum arabic, starch, cellulose, dextrin, polysaccharide, and a group containing carboxyl, sulfonic acid, phosphonic acid, amide group , one or more of homopolymers or copolymers of vinylpyrrolidone monomers.

The addition amount of the development accelerator is 1-20% by weight, preferably 1-15% by weight relative to the weight of the total solid content of the imageable coating.

In addition, the composition described in the present invention can also include various additives in conventional amounts, such as surfactants, colored dyes, adhesion promoters, contrast dyes, polymerization inhibitors, antioxidants or combinations thereof, Or any other add-on commonly used in lithographic techniques.

Formation of printing plate precursors:

The present invention can form a printing plate precursor having an imageable coating by suitably applying the above-described imageable composition to the above-described aluminum plate substrate. Specifically, the imageable composition is dispersed or dissolved in a suitable coating solvent to form a mixed solution, and is coated with suitable equipment and procedures such as spin coating, knife coating, gravure coating, die coating, and slot coating. Cloth, rod, wire rod, roll or extruder hopper coating, the mixed solution is applied to the surface of the substrate support, also by spraying onto a suitable support such as a printing cylinder of a printing machine The composition is applied, and then dried in an oven at 70° C. to 160° C. to remove the coating solvent to obtain the lithographic printing plate precursor.

The choice of solvent used herein depends on the nature of the polymeric binder and other non-polymeric components in the composition, typically coating solvents used under conditions and techniques well known in the art, Examples include: acetone, cyclohexanone, methanol, ethanol, propanol, butanol, methyl ethyl ketone, methyl isobutyl ketone, tetrahydrofuran, 1-methoxy-2-propanol, 2-ethoxy -Ethanol, 2-methoxyethyl acetate, 1-methoxy-2-propyl acetate, dimethoxyethane, methyl lactate, ethyl lactate, N,N-dimethyl Formamide, N,N-dimethylacetamide, tetramethylurea, N-methylpyrrolidone, dimethylsulfoxide, γ-butyrolactone, etc., but not limited to these solvents. A solvent can be used individually by 1 type or in mixture of 2 or more types.

The coat weight of the imageable layer after drying is generally at least 0.1-5 g/m ² , preferably 0.5-3 g/m ² .

In the lithographic printing plate precursors of the present invention, in order to prevent contamination by fat, oil, dust or oxidation and damage by scratching, it is also preferable to provide a protective coating comprising one or more surface protective compounds on the imageable coating. layer. As a material that can be used for the protective layer, any one of water-soluble polymers and water-insoluble polymers can be appropriately selected and used, and two or more kinds can be used in combination as necessary. Specifically, for example, gum arabic, pullulan, cellulose derivatives such as carboxymethylcellulose, carboxyethylcellulose or methylcellulose, dextrin, cyclodextrin, vinyl alcohol, polyvinyl alcohol , Vinylpyrrolidone, polyvinylpyrrolidone, polysaccharides, homopolymers and copolymers of acrylic acid, methacrylic acid or acrylamide, etc. Among them, it is preferable to use a water-soluble polymer compound with relatively excellent crystallinity. Specifically, when polyvinyl alcohol is used as the main component, it can bring the best results for basic properties such as oxygen barrier properties and development removability. .

exposure:

For embodiments of the present invention, the lasers used to expose the lithographic printing plate precursors of the present invention may be carbon arc lamps, high pressure mercury lamps, xenon lamps, metal halide lamps, fluorescent lamps, tungsten lamps, halogen lamps, helium cadmium lamps, Laser, argon ion laser, FD-YAG laser, helium-neon laser, semiconductor laser (350nm-450nm) perform image exposure on the photosensitive layer. The high-performance lasers or laser diodes used in currently commercially available image digital platesetters emit at 405nm, and the imaging device can be configured as a flatbed recorder or a drum recorder, where the imageable element is mounted to the inside or outside of the drum Cylindrical surface. Suitable exposure equipment, for example: CTCP/UV imaging machines of CRON (Korei) and AMSKY (Paulite), Xeikon UV device of BasysPrint, Xpose UV machine of Liischer, Nautilius equipment of ECRM. Depending on the sensitivity of the radiation-sensitive layer, the imaging is generally performed with an energy of 30 mJ/cm2 to 500 mJ/cm2, preferably 50 mJ/cm2 to 300 mJ/cm2.

After exposure and before development, the printing plate precursor can be treated with or without preheating as desired. Generally speaking, the printing plate that has been preheated before development can more or less improve its printing durability. Finally, the imaged lithographic printing plate produced by the aforementioned development process is mounted on a printing press, coated with printing ink and a fountain solution for printing, wherein the fountain solution is filled with non-imaged areas (hydrophilic groups revealed by the imaging and processing steps). surface of the substrate) and the ink is absorbed by areas of the imaging layer (not removed). The ink is then transferred to a suitable receiving material such as cloth, paper, metal, glass or plastic to provide the desired imprint of the image thereon. If desired, an intermediate "transfer roll" can be used to transfer the ink from the imaging member to the receiver material.

The plate-making method of the lithographic printing plate provided by the present invention will be described in detail below in conjunction with specific embodiments. Unless otherwise specified below, most of the component compounds in the examples were obtained from Aldrich Chemical Company (Milwaukee, WI).

Some specific components and materials used in the following examples are as follows:

Binder A is a polymer dispersion of 90% by weight styrene and 10% by weight polyethylene glycol methyl ether methacrylate in propanol/water (80/20 by volume) with a solids content of 23.7% .

Binder B is a solution of a polymer containing 80% by weight methyl methacrylate and 20% by weight methacrylic acid in 2-butanone at a concentration of 33%.

Binder C is a polymer dispersion containing 92% by weight methyl methacrylate and 8% by weight polyethylene glycol methyl ether methacrylate in propanol/water (80/20 by volume), solids content was 24.0%.

Binder D is a polymer containing 20% by weight styrene, 70% by weight cyanoethyl acrylate and 10% by weight polyethylene glycol methyl ether methacrylate in propanol/water (80/20 by volume) Dispersion with a solids content of 23.8%.

Binder E is a polymer solution containing 90% by weight of allyl methacrylate and 10% by weight of polyethylene glycol methyl ether methacrylate in 2-butanone, with a solid content of 10%.

Free-radically polymerizable compound A: reaction product of 1,6-hexamethylene diisocyanate with hydroxyethyl acrylate and pentaerythritol triacrylate (polymer solution in 2-butanone, solids content 80%).

Sartomer 355 is a multifunctional acrylic monomer available from Sartomer Co., Inc.

PI-18 is 2-(4-methoxy-1-naphthyl)-4,6-bis(trichloromethyl)-1,3,5-triazine, available from DKSH Group (Zurich, Switzerland) .

250 is (4-methoxyphenyl)[4-(2-methylpropyl)phenyl]iodonium hexafluorophosphate, commercially available from Ciba Specialty Chemicals (Tarrytown, NY).

PI-0591 is an iodonium salt initiator, which can be purchased from Tokyo Chemical Industry Co., Ltd., Japan.

BYK-341 organic silicon surface additive can be purchased from German BYK company.

TMSPMA stands for 3-(methacryloyloxy)-propyltrimethoxysilane.

The aluminum plate base A is prepared by the following steps: the aluminum plate is degreased in an alkaline solution, electrochemically roughened in an acidic solution, neutralized in an alkaline solution, anodized in an acidic solution, and The aqueous solution is post anodized and finally hot air dried. In an embodiment, this step comprises washing the aluminum plate at 65°C with an aqueous alkaline solution containing sodium hydroxide (3.85 g/l) and sodium gluconate (0.95 g/l) to remove any organic oil from its surface and grease; followed by neutralization using, for example, aqueous hydrochloric acid (2.0 g/l); and finally washed with water to remove excess hydrochloric acid solution. Subsequently, the aluminum plates were subjected to electrolytic roughening using carbon electrodes at 25° C. in an aqueous electrolyte containing aqueous hydrochloric acid (8.0 g/l) and acetic acid (16 g/l). The current and charge density can be 38.OA/dm2 and 70.0C/dm2 respectively. After roughening, the aluminum plates were deashed with aqueous sodium hydroxide solution (2.5 g/l) to remove unwanted impurities prior to anodization, thereafter neutralized with aqueous sulfuric acid solution (2 g/l); and washed with water to Remove excess acid. Subsequently, the aluminum plate undergoes anodization, whereby an aluminum oxide layer is produced. Anodization can take place at 25°C in an aqueous electrolyte containing sulfuric acid (140 g/l); the current and charge density are adjusted to produce an aluminum oxide layer with a thickness between about 2.5 and about 3.5 g/m ² . Subsequently, the base plate was washed with water and treated with an aqueous solution containing sodium dihydrogen phosphate (50 g/l) and sodium fluoride (0.8 g/l) at 75 ° C to enhance the hydrophilicity of its surface, and finally washed with water at 50 ° C. After cleaning and drying with hot air, the required aluminum plate base is obtained.

Developer solution A is a solution prepared as follows: in 750 g of deionized water, dissolve successively under stirring: 13 g of sodium carbonate and 7 g of sodium bicarbonate; 50 g of sodium dodecylbenzenesulfonate; 25 g of gum arabic; 50 g of ethylene glycol Monophenyl ether; 20g p-toluenesulfonic acid; 0.1g

47 Defoamer; deionized water was further added to 1000 g. The pH of developer A was 8.9.

Developer solution B is a solution prepared as follows: in 750 g of deionized water, dissolve successively under stirring: 25 g of sodium bicarbonate and 5 g of sodium carbonate; 50 g of sodium n-butylnaphthalene sulfonate; 3.0 g of disodium edetate ;0.1g

47 Defoamer; deionized water was further added to 1000 g. The pH of developer solution B was 7.4.

Example 1

The imageable composition described in this embodiment includes the following weight percentages:

The above-mentioned components were dissolved in a mixed solvent of 20.2g of 1-methoxy-2-propanol, 9.5g of water and 16.5g of 2-butanone, and the solution was covered by electrochemical coarse On the aluminum plate substrate A obtained by oxidation, anodic oxidation, and phosphate/fluoride hydrophilic layer treatment, and then dried in an oven at 110°C for 2 minutes, that is, before the lithographic printing plate with a coating weight of 1.2g/ ^m2 was prepared body.

The lithographic printing plate precursor obtained in this way can use a 405nm laser on the UVP-820G+ CTcP plate-making machine of CRON (Kolei), the drum rotation speed is 500rpm, and the laser power is 45mW. Developer A is rinsed by MASTER VIEW developing machine for 35s to obtain a good image; you can also choose to directly expose the lithographic printing plate precursor through a UV printing machine, and then directly install it on the printing machine to print more than 500 prints with good quality .

Example 2

The above-mentioned components are dissolved in a mixed solvent of 20.2g of 1-methoxy-2-propanol, 9.5g of water and 16.5g of 2-butanone, and the solution is covered by the electrochemical coarse On the aluminum plate substrate A obtained by oxidation, anodic oxidation, and phosphate/fluoride hydrophilic layer treatment, and then dried in an oven at 110°C for 2 minutes, that is, before the lithographic printing plate with a coating weight of 1.2g/ ^m2 was prepared body.

Example 3

The above-mentioned components are dissolved in a mixed solvent of 20.2g of 1-methoxy-2-propanol, 9.5g of water and 16.5g of 2-butanone, and the solution is covered by the electrochemical coarse on the aluminum plate substrate A obtained by oxidation, anodic oxidation, and phosphate/fluoride hydrophilic layer treatment, and then dried in an oven at 110° C. for 2 minutes, and the weight of the first coating obtained was 1.2 g/m ² . Then cover the top of the first coating layer with a solution of gum arabic (3.0g) and water (94.0g), and then dry it in an oven at 110°C for 2 minutes to prepare a lithographic plate with a total weight of double coating of about 2.2g/ ^m2 Printing plate precursors.

The lithographic printing plate precursor obtained in this way can use a 405nm laser on the UVP-820G+ CTcP plate-making machine of CRON (Kolei), the drum rotation speed is 500rpm, and the laser power is 45mW. Developer B is rinsed by MASTER VIEW developing machine for 35s to obtain a good image; you can also choose to directly expose the lithographic printing plate precursor through a UV printing machine, and then directly install it on the printing machine to print more than 500 prints with good quality .

Example 4

Example 5

The above-mentioned components are dissolved in a mixed solvent of 20.2g of 1-methoxy-2-propanol, 9.5g of water and 16.5g of 2-butanone, and the solution is covered by the electrochemical coarse on the aluminum plate substrate A obtained by oxidation, anodic oxidation, and phosphate/fluoride hydrophilic layer treatment, and then dried in an oven at 110° C. for 2 minutes, and the weight of the first coating obtained was 1.2 g/m ² . Then cover the top of the first layer with a solution of polyvinyl alcohol (3.0g) and water (94.0g), and then dry it in an oven at 110°C for 2 minutes to prepare a double coating with a total weight of about 2.1g/ ^m2. Lithographic printing plate precursors.

The lithographic printing plate precursor obtained in this way can use a 405nm laser on the UVP-820G+ CTcP plate-making machine of CRON (Kolei), the rotating speed of the drum is 500rpm, and the laser power is 45mW. Developer A is rinsed by MASTER VIEW developing machine for 35s to obtain a good image; you can also choose to directly expose the lithographic printing plate precursor through a UV printing machine, and then directly install it on the printing machine to print more than 500 prints with good quality .

Apparently, the above-mentioned embodiments are only examples for clear description, rather than limiting the implementation. For those of ordinary skill in the art, other changes or changes in different forms can be made on the basis of the above description. It is not necessary and impossible to exhaustively list all the implementation manners here. And the obvious changes or changes derived therefrom are still within the scope of protection of the present invention.

Claims

A photosensitive negative-type lithographic printing plate precursor is characterized in that it comprises: (i) an aluminum plate substrate covered with a phosphate/fluoride-containing hydrophilic layer on its surface; (ii) the An imageable coating is applied to the surface of the hydrophilic layer of the aluminum plate base;

Wherein, the phosphate/fluoride hydrophilic layer comprises the following components in parts by mass:

Phosphate 90-99.9 parts;

Fluoride 0.1-10 parts;

Described imageable coating comprises the imageable composition of following mass parts:

25-65 parts of free radical polymerizable compound;

0.5-25 parts of photoinitiator;

10-60 parts of binder;

1-20 parts of developing accelerator.
The lithographic printing plate precursor according to claim 1, characterized in that it is sensitive to radiation with a wavelength in the range of 350nm-450nm.
The lithographic printing plate precursor according to claim 1, characterized in that: the aluminum plate base is an aluminum support that is electrochemically grained and treated by sulfuric acid anodic oxidation.
The lithographic printing plate precursor according to claim 1, characterized in that: the phosphate in the phosphate/fluoride hydrophilic layer is alkali metal phosphate, alkali metal hydrogen phosphate, alkali metal dihydrogen phosphate One or more of them; the fluoride is alkali metal fluoride, alkali metal fluorophosphate, alkali metal fluoroaluminate, alkali metal fluorotantalate, alkali metal fluoroantimonate, alkali metal fluorozirconate One or more of salt, alkali metal fluoroarsenate, alkali metal fluoroborate.
The lithographic printing plate precursor according to claim 1, characterized in that:

The radically polymerizable compound is a polymerizable monomer and/or oligomer containing at least one ethylenically unsaturated double bond;

The photoinitiator has one or more absorption peaks or absorption shoulders in the UV-violet range;

The binder is a carbon-containing polymer in the main chain;

The development accelerator is a low molecular weight hydrophilic organic compound or a high molecular weight hydrophilic polymer.
The lithographic printing plate precursor according to claim 5, wherein the polymerizable monomer and/or oligomer is acrylate, methacrylate, urethane acrylate, urethane methacrylate, Epoxy acrylate or epoxy methacrylate, polyol acrylate, polyol methacrylate, urethane acrylate, urethane methacrylate, polyether acrylate, polyether methacrylate one or more of .
The lithographic printing plate precursor according to claim 5, wherein the photoinitiator is onium salt, trihalomethyl compound, carbonyl compound, azide compound, coumarin, ketocoumarin, anthracene One or more of quinones, organoboron compounds, oxime esters or phosphine oxides.
The lithographic printing plate precursor according to claim 5, wherein the polymer containing carbon in the main chain is acrylic acid, methacrylic acid, acrylate, methacrylate, acrylamide, methacrylamide, benzene A polymer derived from at least one of ethylene and styrene derivatives, acrylonitrile, methacrylonitrile, N-substituted cyclic imides, and maleic anhydride as repeating units.
The lithographic printing plate precursor according to claim 5, characterized in that: the average molecular weight of the carbon-containing polymer in the main chain is 5,000-100,000.
According to the lithographic printing plate precursor described in claim 5, it is characterized in that: the low-molecular-weight hydrophilic organic compound used as a development accelerator is polyhydric alcohol and their ether or ester derivatives, organic amine and their Salt, organic sulfonic acid and their salts; The high molecular weight hydrophilic polymer used as development accelerator is polyethylene glycol, gum arabic, starch, cellulose, dextrin, polysaccharide, and containing carboxyl, sulfonic acid group, phosphonic acid group, amide group, homopolymer or copolymer of vinylpyrrolidone monomer.
A plate-making method of a photosensitive negative-working lithographic printing plate, characterized in that it comprises the following steps:

(1) any photosensitive negative-type lithographic printing plate precursor described in claims 1-10 by patterned exposure, thereby forming an exposed area and an unexposed area;

(2) Remove the unexposed area of the exposed printing plate precursor through a development process to obtain the desired lithographic printing plate, characterized in that: the development process is any one of the following: (i) On-machine development: Development is performed on-press using fountain solutions and/or lithographic inks; (ii) off-press development: development is performed in a processor off-press using a developer solution.
The plate-making method according to claim 11, characterized in that: said developing solution for off-machine development comprises carbonate and/or bicarbonate, carbonate and/or bicarbonate in said developing solution The mass fraction of the salt is 1-20%, and the pH value of the developing solution is 6-11.
The plate making method according to claim 12, characterized in that: the carbonate in the developing solution is an alkali metal carbonate; the bicarbonate in the developing solution is an alkali metal bicarbonate.