JPH046939B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a silver salt lithographic printing plate with improved printing durability and plate elongation. (Prior art) As lithographic printing plates using the silver salt diffusion transfer method, Japanese Patent Publications No. 36-10910, No. 46-42453 and No. 48-
30562, a method using a physical development layer provided on a silver halide photographic emulsion layer as an ink receptive layer, or a method described in US Pat.
No. 3511656, specification No. 3557690 and JP-A-57-
As described in Publication No. 44153, a silver halide photographic emulsion layer is provided on the physical development nucleus layer and a printing image is formed by a diffusion transfer method, and then the upper silver halide emulsion layer is removed to form a printing plate. There are known ways to obtain it. Various supports for these lithographic printing plates are used depending on the purpose or use, and examples include aluminum plates, zinc plates, multilayer metal plates, plastic films, and paper materials. These supports are required from the viewpoint of printing durability, or from the viewpoint of printing characteristics, for example, they must be free from white stains during printing, and also have a printing layer (printed image-bearing layer).
An appropriate support is selected depending on needs, such as strong adhesiveness between the support and the support, manufacturing cost, and ease of handling. In recent years, the demand for direct lithographic printing plates that can be easily printed has increased significantly, and the supports for these printing plates are easy to process, such as coating and cutting, and have appropriate flammability from the perspective of waste disposal. Paper is often used as the support material because it is both inexpensive and inexpensive. Further, the moderate rigidity of the paper support makes it compatible with recent automatic plate making machines or automatic printing machines, which is another reason why it is often used. Many lithographic printing plates to which the silver salt diffusion transfer method according to the present invention is applied also use paper supports. The lithographic printing plate is used to photograph and expose the image lines to be printed, and then to transfer and develop with an alkaline processing liquid to form a printed image. Next, the image is subjected to a development stop bath or surface peeling treatment, and then the image is made hydrophobic with a lipophilic liquid, and then printed using an offset printing machine while supplying ink and dampening water. In this way, in the case of lithographic printing plates that use the silver salt diffusion transfer method, they pass through a strong alkaline bath or an acidic bath in the photographic method, and then are constantly immersed in dampening water during printing. be. Therefore, in order to print a large number of clear printed materials, the plate itself is required to have strong physical properties and mechanical sophistication during these processing steps. Particularly during printing, when dampening water permeates into the paper layer, the paper expands and contracts on the plate cylinder of the printing press, causing serious defects such as plate wrinkles and loss of flatness. Therefore, when paper is used as a support for a lithographic printing plate, both sides of the paper are treated to make it waterproof, specifically by coating with a resin or by applying a hydrophobic polymeric substance, such as a polyolefin-based polymeric compound. Until now, so-called resin-coated paper has been widely used. However, with coated paper such as the one described above, it is impossible to completely prevent the penetration of the processing liquid as described above, and as a result, physical problems including printing durability, etc.
It cannot be denied that it is inferior in terms of mechanical strength. In order to improve these drawbacks, the use of plastic film as a support for silver salt lithographic printing plates has been proposed, for example, in JP-A-57-100431. However, using plastic film as a support is not only extremely expensive, but the inventors have found that it is so stiff that it is difficult to attach it to a printing machine, and it is surprisingly difficult to use. In addition to being bombarded with things,
Unlike paper, it cannot be easily incinerated.
Treatment after use becomes a problem. On the other hand, a technique using aluminum foil laminated paper as a support for a lithographic printing plate using electrophotography is disclosed, for example, in Japanese Patent Application Laid-open No. 58-24149.
It has also been put into practical use. In this way, printing plates using aluminum foil laminated paper as a support are
It is said that there is little plate elongation, and it is also inexpensive and easy to use. Therefore, silver halide lithographic printing plates, which have sharper images, better halftone reproducibility, and better printing durability than electrostatic printing plates, are being used as supports for inexpensive printing plates without plate elongation. The appearance of aluminum foil laminated paper was desired. Nevertheless, no example has yet been found in which the above laminated paper has been applied to a silver salt lithographic printing plate. The reason for this is thought to be that the silver salt lithographic printing plate is processed in a strongly alkaline processing solution. That is, when the above printing plate is treated with a strong alkaline treatment liquid, the aluminum surface and
The adhesion with the hydrophilic binder layer provided thereon is severely impaired and the binder layer is easily peeled off, rendering the silver image unusable for printing, and even during processing as described above. Even if the binder layer does not peel off, the hydrophilic binder layer carrying the silver image may peel off after printing just a few dozen sheets in the subsequent printing process, and the processing conditions may also cause the hydrophilic binder layer to peel off. In some cases, the aluminum foil layer may be corroded by the alkaline treatment liquid. (Object of the Invention) Therefore, an object of the present invention is to provide a silver salt lithographic printing plate that is free from plate elongation, is inexpensive, and is easy to use. (Structure of the Invention) The object of the present invention is to provide an ink-receptive image formed on the surface of an aluminum foil layer of aluminum foil laminated paper by a silver salt diffusion transfer method.A silver salt lithographic printing plate having a hydrophilic colloid layer carrying silver. In this step, at least one
Achieved by a silver salt lithographic printing plate coated with an ionomer resin layer, the resin layer containing a compound having two or more epoxy groups and/or a compound having two or more ethyleneimino groups. I can do it. Hereinafter, the present invention will be explained in further detail. The silver salt lithographic printing plate of the present invention includes a support in which aluminum foil is laminated onto a base paper, and a hydrophilic colloid layer supporting an image silver formed by an ink-receptive silver salt diffusion transfer method is provided on the surface of the aluminum foil layer. It is composed of the following characteristics. According to the present invention, at least one ionomer resin layer is coated on the surface of the aluminum foil layer. The ionomer resin according to the present invention may be mixed in the hydrophilic colloid layer in one embodiment, but it may be provided directly on the aluminum foil layer in the form of an intermediate layer between the hydrophilic colloid layer and the aluminum foil layer. It is preferable to apply it as an anchor layer. The ionomer resin according to the present invention is produced by crosslinking a copolymer of a vibration-saturated hydrocarbon such as ethylene or butadiene with an unsaturated carboxylic acid such as acrylic acid, methacrylic acid, or maleic acid using a metal cation. The obtained resin was used as a special public
No. 6810 and No. 42-15769. The ionomer resin preferably used in the present invention is a copolymer of ethylene and methacrylic acid with a metal cation bonded to it, and is available from, for example, DuPont, Mitsui Polychemicals, Mitsui Petrochemicals, etc. , are commercially available under trade names such as "Surlyn,""Himilan," or "Chemipearl," respectively. It has already been mentioned above that it is preferable to apply such an ionomer resin as an anchor layer directly to the aluminum foil layer, but it is further preferable to apply the ionomer resin while the surface of the aluminum foil layer is in a state where it is less likely to be oxidized. , its application amount is 0.1~
The amount may be 2.0 g/m ² and can be increased or decreased as necessary. Next, according to the present invention, a compound having two or more epoxy groups and/or a compound having two or more ethyleneimino groups is contained in the ionomer resin layer. Typical specific examples of the above-mentioned compounds having two or more epoxy groups are described below. The compounds according to the above examples are manufactured by Nagase Sangyo Co., Ltd.
It is commercially available under the trade name "Denacol" or is known in the photographic industry. Next, typical examples of the compounds having two or more ethyleneimino groups according to the present invention will be described below. The compounds exemplified above are, for example,
It can be produced by the synthesis method described in Japanese Patent No. 3770. The compound having two or more epoxy groups and/or the compound having two or more ethyleneimino groups according to the present invention can be dissolved in water or an organic solvent miscible with water, such as methanol, ethanol, fluorinated alcohol, etc. After that, it is preferably added to the coating solution of the ionomer resin, and the amount added is 0.02 g per 1 g of solid ionomer resin, preferably in the range of 0.05 g to 0.3 g, but the amount can be increased as necessary. can. Further, these compounds according to the present invention may be used alone or in combination of two or more. Furthermore, in addition to the above-mentioned compound according to the present invention, a hardening agent, colloidal silica, a pH adjuster, etc. can be added to the coating solution of the ionomer resin according to the present invention. The aluminum foil laminated paper used as the support for the printing plate according to the present invention is, for example,
It can be manufactured by laminating a base paper with an aluminum foil having a thickness of 0.1 micron or more by the method described in Japanese Patent No. 16892, No. 58-17449, and No. 58-122896. According to the present invention, the silver salt lithographic printing plate of the present invention comprises:
On the above aluminum foil laminated paper support,
An ionomer resin anchor layer containing a compound having two or more epoxy groups and/or a compound having two or more ethyleneimino groups is coated, and a lithographic printing plate is further coated thereon using a silver salt diffusion transfer method. It can be manufactured by coating a hydrophilic colloid layer according to a conventional method. In the present invention, the compound having two or more epoxy groups or the compound having two or more ethyleneimino groups is added to the hydrophilic colloid layer, and the lower layer of the colloid layer is added at the time of coating or thereafter. It is also possible to use an addition method in which the ionomer is diffused into the ionomer layer present in the ionomer layer. The back surface of the aluminum foil laminated paper according to the present invention, that is, the surface opposite to the aluminum foil layer, may be subjected to a commonly used water-resistant treatment. The main resins used for water resistance treatment are:
The following are listed, and these are 0.1 micron ~
Preferably it is applied as a 10 micron layer. For example, polyethylene terephthalate, polyimide, polycarbonate, polyacrylate, polymethyl methacrylate, polyvinyl fluoride, polyvinyl chloride, polyvinyl acetate, polystyrene, styrene-butadiene copolymer, polymethacrylate, silicone resin, chlorinated rubber, epoxy resin, pure and modified Alkyd resin, polyethyl methacrylate, poly-n-butyl methacrylate, cellulose acetate, ketone resin, polyethylene, polypropylene, polyacrylonitrile, rosin derivative, polyvinylidene chloride, nitrocellulose, phenol-formaldehyde resin, methacrisol formaldehyde resin, styrene-anhydride Maleic acid copolymer, polyallylic acid-polyacrylamide copolymer, ethylene glycol fumarate copolymer, methyl vinyl ether-maleic anhydride copolymer, acryloylglycine-vinyl acetate copolymer, polyvinylpyrrolidone, polyvinyl alcohol, Polyamide, halogenated styrene, etc. are used. Further, the water-resistant layer can be given matte properties by adding inorganic or organic fine powder. Printed image using the silver salt diffusion transfer method according to the present invention The hydrophilic colloid layer supporting silver refers to a photosensitive silver halide emulsion layer, a physical development nucleus layer, an antihalation layer, an intermediate layer, and the like. The most preferred form of the layer structure is one with an intermediate layer consisting of a hydrophilic colloid layer between the ionomer resin layer and a physical development nucleus layer that provides ink receptivity necessary for printing, or one with an intermediate layer consisting of a hydrophilic colloid layer, or one with an ionomer resin layer and a physical development nucleus layer that provides ink receptivity necessary for printing. In this form, an antihalation layer is coated between a physical development nucleus layer that provides the ink receptivity necessary for this, and a silver halide emulsion layer is coated on top of the antihalation layer. The antihalation layer refers to a layer containing dye, pigment, or carbon black. As the hydrophilic colloid (binder) of the constituent layer according to the present invention, various types of gelatin treated with acid or lime are preferable, and a part of the gelatin can be used with other hydrophilic polymer compounds such as polyvinyl ether, polyacrylamide, etc. It can be replaced with poly-N-vinylpyrrolidone, polyvinyl alcohol, carboxymethylcellulose, alginic acid, maleic anhydride-ethylene copolymer, and the like. The type of photosensitive silver halide emulsion used in the present invention is selected from commonly used silver chloride, silver bromide, silver iodide, silver chlorobromide, silver chloroiodobromide, silver iodobromide, etc. . The type of emulsion may be either negative type or positive type, and it may be a special type described in JP-A-54-48544, which uses photosensitive silver halide and non-photosensitive silver halide that has been rendered difficult to dissolve. Good too. These silver halide emulsions can also be chemically or spectrally sensitized as required. Further, the photosensitive emulsion may be stabilized with adendenes. For the hydrophilic colloid layer, hardening agents commonly used in the art may be used alone or in combination, including aldehyde hardening agents, such as formalin, glyoxal, or N-methylol compounds such as ethylene urea. etc. are particularly preferred. Furthermore, the addition of a silane capturing agent provides even more favorable results in terms of adhesion. Examples of the above-mentioned silane coupling agents are listed below. (3-3) _CH2 =CH−Si−( _OCOCH3 ) ₃ (3-5) H ₂ NCH ₂ CH ₂ NH(CH ₂ ) ₃ Si(OCH ₃ ) ₃ The compounds exemplified above are commercially available from, for example, Toray Silicon Co., Ltd. and the like. After image exposure, the lithographic printing plate in the present invention is developed with a silver halide developing agent. As the developing agent, polyhydroxybenzenes and 3-pyrazolidinones are preferable, and these agents may be used in the form of a so-called agent-containing type, which is contained in the constituent layers of the plate material. The physical development nuclei of the physical development nucleus layer in the present invention may be those used in the known silver salt diffusion transfer method, such as colloids such as gold and silver, palladium,
Metal sulfides, which are a mixture of water-soluble salts such as zinc and sulfides, can be used. For details and manufacturing methods, see, for example, edited by WFBerg, Photographic
Silver Halide Diffusion Processes 1972.Focal
Press may be referred to. After image exposure, the lithographic printing plate according to the present invention is processed in an alkaline processing bath in the presence of a silver halide developer. When a developer is included in the plate material in advance, only an alkaline treatment bath is required, or the developer may be included in some cases. These alkaline treatment baths can use caustic soda, caustic potassium, sodium carbonate, potassium carbonate, etc. as alkaline agents, and the pH of the treatment bath is 8.
It is preferable to use between 14 and 14. Silver halide bath agents in the alkaline treatment bath include sulfites such as sodium sulfite, thiosulfates such as sodium thiosulfate and ammonium thiosulfate, thiocyanates such as sodium thiocyanate, amino acids such as cystine and cysteine, Examples include thiourea type and thioether type. As described above, the present invention is a lithographic printing plate using a silver salt diffusion transfer method using aluminum foil laminated paper.The advantages of the present invention can be summarized as follows. [1] Since the elongation of the plate during printing is reduced, high-quality printed matter can be obtained. [2] Since various processing liquids during plate making or dampening water during printing do not penetrate into the paper layer, printing durability is improved as a support for silver salt lithographic printing. [3] The physical and mechanical strength of the coating film is improved due to the excellent attachment properties between the support and the hydrophilic colloid layer. [4] There is no need for corona discharge treatment, which is done with conventional resin-coated paper. Hereinafter, the present invention will be explained in more detail with reference to Examples. Example 1 An anchor layer with a solid content of 1.0 g/m ² was applied to the surface of an aluminum laminated paper obtained by laminating a 10 micron thick aluminum foil onto a base paper weighing 130 g/m ² . did. The resin composition of this anchor layer and the added compounds are as described in Table 1. Next, a liquid having the following composition was applied to the opposite side of the aluminum laminated paper (coating amount: 5 g/m ² ) to make it waterproof. On the anchor layer of the obtained aluminum laminated paper, an antihalation layer containing carbon black and then a photosensitive silver halide emulsion layer were simultaneously coated in a multilayer manner. However, as an antihalation layer, the transmission density is
A gelatin aqueous solution in which carbon black (FX-4236 manufactured by Toyo Ink) is dispersed in an amount of 1.5 or more,
In addition, fine silica powder (Fuji Davison Co., Ltd., Cyroid 308) was added as a matting agent, hydroquinone and dimedone as developing agents, formalin as a hardening agent, sodium octylsulfosuccinate was added as a coating aid, and the pH was adjusted to 4.7. A coating solution was applied so that the amount of gelatin was 4.0 g/m ² . A photosensitive silver halide emulsion is prepared by chemically sensitizing a silver chloride emulsion prepared by the usual double jet method, chemically sensitizing it with sulfur, and orthosensitizing it using a photosensitive dye, and adding 4-hydroxy-6-methyl- as a stabilizer.
A suitable amount of 1,3,3a,7-tetracindene is added, and fine silica powder and sodium isoamyl-n-decylsulfosuccinate as a coating aid are added to adjust the pH to 4.7. The amount of silver coated was 1.0 g/m ² . Next, a palladium sulfide colloidal solution prepared from palladium chloride and sodium sulfide as physical development nuclei was applied onto the emulsion layer by an air knife method after adding the same coating aid as above, and a sample of the lithographic printing plate was prepared. Obtained. 40 samples obtained above
After being left for 5 days under conditions of ℃ and RH 50%, immersed in fresh water at 30℃ and a strong alkaline (2.5% potassium hydroxide) aqueous solution for 30 seconds,
The adhesion between each coating constituent layer and the support was examined. For measurement, each sample was immersed in fresh water or a strong alkaline aqueous solution, then scratched with a knife, rubbed with a cotton cloth under a certain load, and evaluated based on the amount of load required to peel the coated layer from the support. . The obtained results are shown in Table 1 below.

[Table] Details of the resin composition in the above table are as follows. (A) Sample No. 2 Movinyl 987 resin This was prepared using an acrylic ester copolymer emulsion manufactured by Hoechst in accordance with the technique disclosed in the Examples of JP-A-58-36494. (B) Resin mixture of sample No. 4 The following composition was applied according to the formulation disclosed in the Examples of JP-A-57-176063. Polyvinyl alcohol (10% aqueous solution)
500 parts by weight Exemplary compound (2-7) 10 SBR latex (solid content 50%) 300 Kaolin clay (50% water dispersion) 250 (C) Chemipearl resin of samples No. 5 to No. 14 Mitsui It is a product name of Petrochemical Industry Co., Ltd., and various symbols are attached depending on the type of metal cation, particle size, viscosity, etc., and it is used as a 25% to 40% aqueous dispersion. The symbols representing adhesive properties in the table are as follows. XX indicates that peeling occurs under a load of 300 g or less × 〃 1 kg 〃 ○ indicates that peeling does not occur under a load of 2 kg As shown in the results in Table 1 above, the ionomer resin layer on the aluminum foil layer is an example of the present invention. It can be seen that the silver salt lithographic printing plate sample of the present invention containing the compound has excellent adhesion between the support and the hydrophilic colloid layer not only in fresh water but also after treatment with a strong alkaline aqueous solution. Example 2 Samples No. 4, No. 7, No. 10, and No. prepared in Example 1.
In addition to No. 12, sample No. 15 was prepared by adding 25 mg of exemplified compound (3-1) per 1 g of gelatin to the antihalation layer of No. 12. -300) image exposure,
Development and stabilization treatments were performed. The composition of the treatment liquid used is as follows. (Alkali activation bath) Caustic potash 25g Anhydrous sodium sulfite 50g Sodium thiosulfate 3g 2-Mercapto-5-methyl-oxadiazole 0.1g Finish to 1 with water. (Stabilization bath) Citric acid 15g Sodium citric acid 30g Add water to make 1. After wiping off a lipophilic liquid (composition below) on the plate surface of the plate material obtained in this way, an offset printing machine (Gestettner 200, manufactured by Gestettner) was applied.
Then, printing was carried out by supplying dampening water. (Lophophilic liquid composition) 2-Mercapro-5-n-octyloxadiazole 0.1g Ethyl alcohol 30ml Finish up to 100ml with water. The printability obtained is as shown in Table 2 below, and the printing evaluation in the table was determined by the following method. Printing durability: Evaluate from peeling, wrinkles, etc. of the printed image layer when printing continuously. ◎: More than 8000 sheets can be printed ○: 5000 to 6000 sheets can be printed ×: More than 1000 sheets cannot be printed

[Table] As is clear from the above table, silver halide lithographic printing plate samples No. 7, No. 10, No. 12, and No. 15 according to the present invention all have excellent printing durability, especially in halation. Sample No. 15, in which a silane coupling agent was added to the prevention layer,
It can be seen that the printing durability is even better. (Effect of the invention) A silver salt lithographic printing plate in which an aluminum foil laminated paper is used as a support, an ionomer resin layer is provided on the upper layer, and the compound according to the present invention is added to the resin layer has hydrophilic properties with the support. It was revealed that it has excellent adhesion to the colloid layer and also has excellent printing durability.

Claims (1)

[Claims] 1. An ink-receptive image formed on the surface of the aluminum foil layer of aluminum foil laminated paper by a silver salt diffusion transfer method.In a silver salt lithographic printing plate having a hydrophilic colloid layer supporting silver, at least A silver salt flat plate coated with one ionomer resin layer, the resin layer containing a compound having two or more epoxy groups and/or a compound having two or more ethyleneimino groups. Print version.