JPS60260958A - Lithographic printing plate containing silver salt - Google Patents

Abstract

PURPOSE:To obtain a convenient lithographic printing plate causing no elongation and having superior printing resistance by forming an ionomer resin layer contg. a specified compound on the surface of Al foil having a hydrophilic colloidal layer which supports an ink receptive silver image. CONSTITUTION:When a hydrophilic colloidal layer which supports an ink receptive silver image formed by a silver salt diffusion transfer process is formed on the surface of the Al foil of Al foil laminated paper to obtain a lithographic printing plate contg. a silver salt, an ionomer resin layer contg. a compound represented by the formula (where R<1> is lower alkyl, alkenyl or aryl, each of R<2>- R<4> is lower alkyl, alkoxy, alkylcarboxy, epoxyalkoxy or the like, at least one of R<1>-R<4> has epoxy, vinyl or amino at the terminal, and the others do not have such a group at the terminal) is formed on the surface of the Al foil. Since the ionomer resin layer is formed on the Al foil as an anchoring layer, the elongation of the resulting plate during printing is reduced. The permeation of dampening water into the paper is prevented, the adhesive property of the colloidal layer to the support can be improved, and corona discharge treatment can be eliminated. Accordingly, the printing quality and printing resistance as well as the strength of a coated film are increased.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a silver salt lithographic printing plate with improved printing durability and plate elongation.

(Prior art) As a lithographic printing plate using the silver salt diffusion transfer method,
-10910, 46-42453 and 48-3
A method using a physical development layer provided on a silver halide photographic emulsion layer as an ink receptive layer as described in Japanese Patent No. 0562, or US Pat. No. 3,511,656
No. 3,557,690 and JP-A No. 1987-
As described in Japanese Patent 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, such as aluminum plates, zinc plates, multilayer metal plates, plastic films, paper materials, etc. .

These supports are required from the viewpoint of printing durability, or from the printing characteristics, for example, there should be no wobbling on the white surface during printing, and there is also a risk of Iy adhesion between the printing layer (printed image bearing layer) and the support. The most appropriate supportive care is selected depending on the need, such as material, cost, manufacturing cost, or 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 a support because it is inexpensive and easy to use.

Further, the appropriate rigidity of the paper support makes it compatible with recent automatic plate making machines and 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.

After photographing and exposing both lines to be printed on the lithographic printing plate,
Transfer and develop with an alkaline processing liquid to form a printed image.

Generally, the image is subjected to a development stop bath or a surface peeling treatment, then the image is made hydrophobic with an oleophilic 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 a turbulent bath, etc. in the photographic method, and then undergo a process of being immersed in dampening water during printing. It is something.

Therefore, in order to print a large number of clear printed materials, the plate itself is required to have strong physical properties and mechanical strength 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 wrinkles and loss of flatness.

Therefore, when paper is used as a support for a lithographic printing plate, both sides of the paper are coated with water-resistant treatment, specifically coating with a resin or hydrophobic polymer, such as a polyolefin-based polymer. Until now, so-called resin-coated paper has been widely used.

However, coated paper such as the one described above cannot completely prevent the penetration of the processing liquid as described above, and therefore it is undeniable that it is inferior in terms of physical and mechanical strength, including printing durability. .

In order to improve these drawbacks, the use of a plastic film as a support for a silver salt lithographic printing plate has been proposed, for example, in JP-A-57-100431. However, using a plastic film as a support is an extremely expensive scale, and the inventors have found that it is too rigid, making it difficult to attach it to a printing machine, and is surprisingly inconvenient to use. Moreover, unlike paper, it cannot be easily incinerated, so how to dispose of it 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 in, for example, Japanese Patent Application Laid-Open No. 58-24149, and has also been put to practical use. In this way, printing plates using aluminum foil laminated paper as a support have little plate elongation, are inexpensive, and are said to be 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 stretching. It was hoped that aluminum foil laminated paper would emerge.

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-mentioned printing plate is treated with a strong alkaline processing liquid, the adhesion between the aluminum surface and the hydrophilic binder layer provided thereon is significantly impaired, and the binder layer is easily peeled off, resulting in a toned image. Even if the binder layer does not peel off as described above during processing, slight force A may be applied during the subsequent printing process.
After printing several dozen sheets, the hydrophilic binder layer carrying the silver image may separate 911, and depending on the processing conditions, the aluminum foil layer may be corroded by the alkaline solution.

(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 a silver salt lithographic plate having a hydrophilic colloid layer supporting an ink-receptive image silver formed on the surface of an aluminum foil layer of an aluminum foil laminated sheet by a silver salt diffusion transfer method. Silver salt lithographic printing characterized in that, in the printing plate, at least an ionomer resin layer of IIN is coated on the surface of the aluminum foil layer, and the resin layer contains a compound represented by the following general formula [■]. Achieved by edition.

General formula [I] However, in the formula, R1 represents a substituted or unsubstituted lower alkyl group, lower alkenyl group or aryl group,
Examples of the substituent include an epoxy group, an amino group, and a vinyl group that have the ability to bond with a reactive group of a hydrophilic colloid.

Further, R2, R3 and R4 represent a lower alkyl group, an alkoxy group, an alkylcarboxy group, an epoxyalkoxy group, an alkenyl group or an aryl group.

However, at least one of R1, R2, R3, and R4, which is centered on a silicon atom, has an epoxy group, vinyl group, or amine group at the end, and at least one of the remaining ones has the above group at the end. I don't have it.

The present invention will be further explained in detail below.

The silver salt lithographic printing plate of the present invention has a support made of a base paper laminated with aluminum foil, and a hydrophilic colloid layer carrying image silver formed by a silver salt diffusion transfer method that has no ink receptivity on the aluminum foil layer image. The feature is that:

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 the anchor as a single layer.

The ionomer resin according to the present invention is produced by crosslinking a copolymer of an unsaturated hydrocarbon such as ethylene or phtadiene with an unsaturated carboxylic acid such as acrylic acid, methacrylic acid, or maleic acid using a metal cation. The obtained resin was used in Japanese Patent Publications No. 39-6810 and No. 42-157
It is stated in the 69th bulletin.

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 DuPont, Mitsui Polychemicals, Mitsui Petrochemicals, and the like. , respectively "Sarlin", "Himilan" or "Chemivar"
It is commercially available under the trade name.

It has already been mentioned above that it is preferable to coat the surface of the aluminum foil layer with such an ionomer resin as an anchor layer, but it is further preferable that the coating is applied while the surface of the aluminum foil layer is less oxidized. ,
The coating amount may be 0.1 to 3.0 g/m<3>, and can be increased or decreased as necessary.

In the present invention, examples of the organic silane compound represented by the general formula [I] contained in the ionomer resin layer include compounds such as the following exemplified compounds. Of course, the compound 1] is not limited to this.

(Exemplary Compounds) These compounds are commercially available and easily available. For example, SH series compounds (Toray Silicon Co., Ltd.)
(manufactured by Chisso Corporation), silane camping agents (manufactured by Chisso Corporation), etc.

It can also be synthesized according to the method described in Japanese Patent Publication No. 48-3565. When using the compound of the general formula [I], it is preferable that water or an organic solvent having an affinity for water be dissolved in methanol, ethanol, acetone, etc. and then added to the ionomer resin coating solution. The amount added is 0.00% per 1g of ionomer resin solid content.
Although the amount is in the range of 0.01 g to 0.5 g, it can be increased or decreased as necessary.

In addition, these compounds according to the present invention may be used alone,
Two or more types may be mixed and used.

In addition to the above-mentioned compounds according to the present invention, a hardening agent for curing the ionomer resin, colloidal silica, a pH adjuster, etc. can be added to the coating solution of the ionomer resin according to the present invention.

As the above-mentioned hardener, in particular, when used in combination with a compound having two or more ezalenimino groups, more favorable results can be obtained in terms of adhesive properties. Typical specific examples of the above-mentioned compounds having two or more ezalenimino groups are described below.

(Exemplary Compounds) The compounds exemplified above are, for example, Japanese Patent Publication No. 53-377
It can be produced by the synthesis method described in Publication No. 0.

The aluminum foil laminated paper used as a support for the printing plate according to the present invention is disclosed in, for example, Japanese Patent Application Laid-Open No. 58-16892.
It can be manufactured by laminating a base paper using an aluminum foil having a thickness of 0.1 micron or more according to the method described in Japanese Patent No. 58-17449 and No. 58-122896.

According to the present invention, the silver salt lithographic printing plate of the present invention is prepared by applying the general formula [■
It can be produced by applying an ionomer resin anchor layer containing the compound represented by ], and further applying a hydrophilic colloid layer of a lithographic printing plate using a silver salt diffusion transfer method in accordance with a conventional method. .

After coating the ionomer resin anchor layer, heat treatment or the like may be performed as necessary to increase the strength.

Furthermore, a conventional surfactant may be added to the ionomer resin coating solution in order to obtain uniformity of coating.

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 include the following, and these are preferably applied as a layer of 0.1 micron to 10 micron.

Examples include polyethylene prephthalate, polyimide, polycarbonate, polyacrylate, polymethyl methacrylate, polyhinyl fluorite, polyvinyl chloride. Trihinyl acetate, polystyrene, styrene-butadiene copolymer, polymethacrylate, silicone resin, chlorinated rubber, epoxy resin, pure and modified alkyd resin polyethyl methacrylate, poly-n-phthyl methacrylate, cellulose acetate, ketone resin, polyethylene , polypropylene, polyacrylonitrile, rosin derivatives, polyvinylidene chloride, nitrocellulose, phenol-formaldehyde resin, metacresol formaldehyde resin, styrene-maleic anhydride copolymer,
Polyacrylic acid-polyacrylic acid amide copolymer, ethylene glycol fumarate copolymer, methyl vinyl ether-maleic anhydride copolymer, acryloylglycic acid-
Vinyl acetate copolymer, polyhinylhydrolidone, polyvinyl alcohol, polyamide, halogenated styrene, etc. are used.

Furthermore, the water-resistant layer can also be given matte properties by adding fine inorganic or organic powder.

Printed images 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, etc. 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 flux.

As the water-extensible colloid (binter) of the structural layer according to the present invention, various types of seratin treated with acid or lime are preferable, and some of them may be mixed with other hydrophilic polymer compounds,
For example, it can be replaced with polyhinyl ether, polyacrylamide, 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 or positive, and it may be of a special type described in JP-A-94-48544, which uses photosensitive silver halide and non-photosensitive silver halide that has been rendered insoluble. Good too. These silver halide emulsions can also be chemically or spectrally sensitized as required.

Further, the photosensitive emulsion may be stabilized with azaindenes. For the hydrophilic colloid, hardening agents commonly used in the art can be used alone or in combination, and aldehyde hardening agents, such as formalin, glyoxal, N-methylol compounds such as ethylene urea, etc. is sometimes preferable.

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 gold,
Colloids such as silver, water-soluble salts such as palladium and zinc, and metal sulfides containing sulfides can be used. For details and manufacturing methods, see, for example, W. F. Berg, ed., Photographic SilverHalid
e Diffusion Processes 197
2. Focal Press.

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. In advance,
When a developer is contained in the plate material, only an alkaline treatment bath is required, or the developer may be included in some cases.

In these alkaline treatment baths, caustic sorter, caustic potassium, sodium carbonate, sodium carbonate, etc. can be used as alkaline agents, and the pH of the treatment bath is preferably between 8 and 14.

Silver halide solvents in the alkaline treatment bath include sulfites such as sodium sulfite, sodium thiosulfate,
Examples include thiosulfates such as ammonium thiosulfate, thiocyanates such as sodium thiocyanate, amino acids such as cystine and cysdine, thioureas, thioethers, and the like.

As described above, the present invention is a lithographic printing plate using a silver salt diffusion transfer method using aluminum foil laminated paper, and the advantages of the present invention are 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] Since the adhesiveness between the support and the hydrophilic colloid layer is excellent, the physical and mechanical strength of the coating film is improved.

[4] There is no need for corona discharge treatment, which is done with conventional resin-coated paper.

EXAMPLES 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/m2 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/m2. , curing was performed by heating. The resin composition of this anchor layer and the added compounds are as described in Table 1.

Next, a polyethylene terephthalate solution was applied to the opposite side of the aluminum laminated paper (coating layer: 5 g/m2) to make it waterproof.

An antihalation layer containing carbon black and then a light-sensitive silver halide emulsion layer were simultaneously coated onto the single layer of the aluminum laminated paper anchor.

However, as an antihalation layer, carbon black (manufactured by Toyo Ink, FX-
4236) is dispersed in gelatin, and in addition, fine silica powder (Fuji Tepison Co., Ltd. Thyroid 30) is used as a matting agent.
8) Apply a coating solution containing hydroquinone and dimazone as developing agents and formalin as a hardening agent, adding sodium octylsulfosuccinate as a coating aid, and adjusting the pH to 47 so that the amount of gelatin is 40 g/m3. did.

The photosensitive halogenated steel emulsion is made by chemically sensitizing a silver chloride emulsion prepared by the usual tuuffle jet method, chemically sensitizing it with sulfur, ortho-sensitizing it with a photosensitive dye, and adding 4-4 as a stabilizer.
Added an appropriate amount of hydroxy-6-methyl-1,3,3a,7-tetrazaindene, and further added fine silica powder and sodium inamyl-n-decylsulfosuccinate as a coating aid to adjust the pH to 47. The amount of silver coated was 1.0 g/m3 in terms of silver.

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 lithographic printing plate sample was obtained. I got it. The sample obtained above was left for 50 minutes at 40°C and 50% RH.
After immersion in a 5% potassium hydroxide aqueous solution for 30 seconds, the adhesion between each coating layer and the support was examined.

Measurements are made by immersing the sample in fresh water or a strong alkaline water bath, then scratching each sample with a knife, rubbing with a cotton cloth under a certain load, and evaluating by the amount of load required to peel the coated layer from the support. did. The obtained results are shown in Table 1 below.

Details of the resin composition in the above table are as follows.

(A) Sample No. It was prepared using an acrylic acid ester copolymer emulsion manufactured by Hoechst's Movinyl 987 resin No. 2 according to the technique disclosed in the Examples of JP-A No. 58-36494.

(B) Sample No. The resin mixture of No. 4 was coated with the following composition according to the formulation disclosed in the Examples of JP-A-57-176063.

(C) Sample No. 5~No. 11 Chemipearl resin A product name of Mitsui Petrochemical Industries, Ltd., various symbols are attached depending on the type of metal cation, particle size, viscosity, etc.
% to 40% aqueous dispersion.

In addition, the symbols representing adhesiveness in the table are as follows.

As shown in the results in Table 1 above, the silver salt lithographic printing plate sample of the present invention, in which the ionomer resin layer on the aluminum foil layer contains the exemplified compound according to the present invention, was treated not only with fresh water but also with a strong alkaline aqueous solution. It can be seen that the adhesion between the support and the hydrophilic colloid layer is excellent even after the test.

Example 2 Sample No. prepared in Example 1. 4.No. 7.No. 9
, No. 11 and no. In addition to No. 7, there is a new No. Sample No. 7 was prepared by adding 20 mg of exemplified compound (1-1) per 1 g of gelatin to the antihalation layer of No. 7. 12 was prepared,
Each of the above samples was processed using an automatic plate making machine (IPA-3 manufactured by ITEC Corporation).
Image exposure, development, and stabilization processing were performed using 00). The composition of the treatment liquid used is as follows.

After wiping off a lipophilic liquid (composition below) on the plate surface of the plate material obtained in this way, it is applied to an offset printing machine (Gestettner 200, manufactured by Gestettner), and printing is performed by supplying dampening water. Ta.

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 and wrinkling of the printed image layer when printing continuously.

As is clear from the above table, silver halide lithographic printing plate sample No. 1 according to the present invention. 7.No. 9, No. 11, No. 12
It can be seen that all of these have excellent printing durability, and in particular, when used in combination with a compound having two or more ethyleneimine groups, the printing durability is even more excellent.

(Effects of the Invention) A silver background 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.

Agent Patent Attorney No 1) Parent-in-law

Claims (1)

[Claims] On the aluminum foil surface of the aluminum foil laminated paper,
In a silver salt lithographic printing plate having a hydrophilic colloid layer supporting an ink-receptive image steel formed by a silver salt diffusion transfer method, at least one ionomer resin layer is coated on the surface of the aluminum foil layer, A silver salt lithographic printing plate, wherein the resin layer contains a compound represented by the following general formula [I]. General formula [I] R2 [wherein R1 represents a substituted or unsubstituted lower alkyl group, lower alkenyl group or aryl group. R2, R3 and R2' are lower alkyl groups, alkoxy groups, alkylcarboxy groups, epoxyalkoxy groups,
Represents an alkenyl group or an aryl group. However, R1, R2, R3 and R4 centered on silicon atoms
At least one of them has an epoxy group, a vinyl group, or an amino group at its terminal, and at least one of the remaining ones does not have the above-mentioned group at its terminal. ]