JP4638259B2 - Planographic printing plate making method - Google Patents

Description

  The present invention relates to a method for producing a lithographic printing plate, and in particular, an ink jet capable of producing a lithographic printing plate directly from digital information output from a computer, a facsimile machine or the like without using a film having a negative or positive image. The present invention relates to a direct plate making method using a method.

  In recent years, with the advancement of computer technology, the digitization of information has rapidly progressed in the process from the preparation of the block, which is the upstream process of the printing process, to the preparation of the printing plate. Systems and scanners that directly read images were put into practical use. Accordingly, there is a demand for a direct plate-making method that can produce a lithographic printing plate from digital information output from a computer, a facsimile, or the like without using a plate-making film.

  As such a direct plate-making method, a method of producing a printing plate by forming an image line portion or a non-image line portion directly on a support by an ink jet method is known. The ink jet method is relatively fast as an image output method and does not require a complicated optical system, and thus has a simple structure. Therefore, in this plate making system, it is possible to simplify the apparatus, and the maintenance labor can be greatly reduced, so that the plate making cost can be reduced.

  As an example of a method for producing a printing plate by directly forming an image area or a non-image area on a support by an inkjet method, JP-A-51-84303 and JP-A-56-113456 disclose A plate making method for producing a printing plate by attaching an ink repellent material such as curable silicone to the surface of the support of the printing plate using an inkjet method is disclosed. The printing plate obtained by this method is an intaglio printing plate in which the ink repellent material formed on the support surface is a non-image area. Therefore, the printed image is inferior in the resolution of the shadow part. Furthermore, in this method, since it is necessary to adhere the ink repellent material to the entire non-image area that occupies most of the printing plate surface, a large amount of ink is required, and the plate making process is delayed.

  In JP-A-61-27953, a hydrophobic material that is solid at around room temperature is used as an ink composition by melting with a heating head, and an image area is formed on a support by an ink jet method. Thereafter, a plate making method is disclosed in which the image portion made of the hydrophobic material is solidified by cooling to room temperature again. In general, such a heat-soluble hydrophobic material is waxy and does not have sufficient hardness after solidification at room temperature, so that the obtained printing plate is inferior in printing durability. In JP-A-4-69244, a printing plate is formed using an oleophilic ink having a photocuring component, forming an image by an inkjet method on a recording material that has been subjected to a hydrophilic treatment, and exposing the entire surface with actinic rays. A method is disclosed. In general, the surface of a support used for a lithographic printing plate is subjected to various treatments such as graining, anodization, and hydrophilization in order to improve hydrophilicity and water retention. Therefore, it is necessary to use an ink composition having a very high surface tension in order to form a good image without blurring directly on the surface of the support by an ink jet method. However, on an image line formed with such an ink composition. On the other hand, there is a problem that ink is not sufficiently transferred during printing, and as a result, a good printed matter cannot be obtained.

In order to solve the problem of bleeding due to the ink jet system, Japanese Patent Laid-Open No. 5-204138 (Patent Document 1) uses a hydrophilic polymer as an ink absorbing layer, and ink jets a photopolymerizable ink composition onto a lithographic printing plate coated on a hydrophilic substrate. It has been proposed to print and make a plate using this method. However, when the oil-based ink is driven into the hydrophilic polymer, the ink does not repel or is not completely mixed with the layer, so that sufficient strength cannot be obtained. Similarly, in Japanese Patent Laid-Open No. 10-119230 (Patent Document 2), an ink receiving layer is made of a base as an ink receiving layer in order to make an image part insoluble by ink jet printing and to dissolve a water-soluble non-image part. A method has been proposed in which neutralized acidic polymer is used as a hydrophilic polymer to make it insoluble by printing acid or polyvalent metal. In this case, the ink does not repel due to the aqueous solution being driven into the hydrophilic polymer, but the hydrophilic group of the polymer remains as it is, so there is not sufficient ink acceptance during printing, and a stable printing plate Must not. Japanese Patent Application Laid-Open No. 2004-66816 (Patent Document 3) prints an anionic oleophilic agent on a cationic polymer layer and uses the oleophilic property of the oleophilic agent to ensure ink acceptability. However, the bond between an anion and a cation makes it difficult to obtain a sufficient bond strength, resulting in a problem that a sufficient printing durability cannot be obtained.
Japanese Patent Laid-Open No. 5-204138 (page 5) JP 10-119230 A (page 3) JP-A-2004-66816 (first page)

  The present invention solves the above-mentioned conventional problems, and the object of the present invention is to provide a lithographic plate having good resolving power and printing durability without using a plate-making film from digital information output from a computer or facsimile. An object of the present invention is to provide a direct plate making method capable of easily producing a printing plate.

The above-mentioned problem is characterized in that an image is formed by printing a composition containing a crosslinking agent for polyallylamine on a lithographic printing plate having a layer containing at least one polyallylamine on a support using an inkjet method. This can be solved by using a lithographic printing plate making method.

  According to the present invention, a plate making method of a lithographic printing plate having good resolution and printing durability can be provided.

In the present invention, an image forming layer is provided on a support. The image-forming layer needs to absorb the composition containing the crosslinking agent and quickly absorb the composition containing the crosslinking agent and react quickly in order to obtain a lithographic printing plate excellent in resolution and printing durability. Otherwise it cannot be used practically. For this reason, the image forming layer contains at least one primary amine polymer. As the primary amine polymer, polyallylamine or a polymer containing allylamine, for example, a copolymer of allylamine and diallylamine, a copolymer of allylamine and acrylamide, or chitosan can be used. These have primary amines. Among these primary amine polymers, polyallylamine is used. It is also possible to use a mixture of a plurality of these primary amine polymers. The molecular weight of the primary amine polymer is preferably 5000 or more, more preferably 10,000 to 100,000.

  In the image forming layer in the present invention, a known water-soluble polymer can be used in addition to the primary amine polymer. Since polyallylamine, which is the most preferred primary amine polymer, cannot form a dry film by itself, it is necessary to use another water-soluble polymer in this case. As the water-soluble polymer, it is preferable to use a cationic or nonionic polymer. Examples of these water-soluble polymers are polyvinyl alcohol (PVA), polyvinyl pyrrolidone, polyacrylamide, methylcellulose, hydroxyethylcellulose, hydroxylpropylmethylcellulose, casein, gelatin, agar, dextrin, starch, water-soluble polyurethane, water-soluble nylon, polydiallyldimethyl. Ammonium chloride, polyethyleneimine, polyvinylimidazole, polydiallylamine, polymethyldiallylamine, diallyldimethylammonium chloride and acrylamide copolymer, diandianamide and diethylenetriamine copolymer, diallyldimethylammonium chloride and sulfur dioxide copolymer, diallylamine and sulfur dioxide Examples include copolymers. Among these, a polymer having a group capable of reacting with a crosslinking agent for a primary amine polymer, for example, a polymer having a hydroxyl group, a secondary amine, etc., alone does not sufficiently crosslink, but does not achieve the object of the present invention, but has an auxiliary function. It is preferable to use a polymer that can be used. In addition, it is also preferable from the viewpoint of ink acceptability when performing lithographic printing to use a polymer having kraft polymerization of these water-soluble polymers and having increased hydrophobicity.

In the present invention, the total amount of the water-soluble polymer in the image forming layer is preferably 0.1 to 5 g / m ² , and preferably 0.5 to 3 g / m ² . Among these, the primary amine polymer is contained in an amount of 1 to 100% by mass, preferably 5 to 60% by mass. In order not to aggregate the primary amine polymer of the coating layer, the film surface pH is preferably 9 or more, preferably 10 or more, or 3.5 or less, preferably 2 or less.

In the present invention, the image forming layer preferably contains a latex in order to enhance ink acceptability when performing lithographic printing. As the latex, various known latexes such as SBR type, NBR type, MBR type, polyether type urethane, polyester type urethane, polyester type and acrylic type can be used, but it is preferable to use non-self-crosslinking type latex. As content, 0.1-3 g / m < ² > is preferable as solid content, and the ratio of the solid content is 10-300 mass% with respect to the water-soluble polymer in an image forming layer, Preferably 20-200 mass% is contained. .

  In the present invention, the image forming layer includes a pigment such as silica for improving the absorbability of the composition containing a crosslinking agent when printing by an inkjet method for image formation, and a mat for adjusting the surface roughness of the image forming layer. Materials, surfactants, antistatic agents, coloring materials such as dyes and pigments, and antifoaming agents can be contained.

  As the support of the lithographic printing plate of the present invention, paper, or a synthetic or semi-synthetic polymer film, a metal plate such as aluminum or iron, etc. that can withstand lithographic printing can be used. It is preferable to use. Further, the surface of the support can be coated on one or both sides with one or more polymer films or metal thin films. The surface of these supports can be surface-treated in order to improve the adhesion with the coating layer. Further, for example, an undercoat layer described in JP-A-5-100430 can be provided between the support and the image forming layer, and the image forming layer can be provided thereon.

  When aluminum is used as the support of the lithographic printing plate of the present invention, degreasing treatment, roughening treatment, anodizing treatment, etc., which are usually used in this technical field, are performed. A support in which the oxidation treatment is performed in this order is preferable.

  The aluminum plate used in the present invention is degreased to remove fatty substances from the surface. Degreasing treatment includes solvent degreasing such as trichrene and thinner, emulsion degreasing, acid degreasing, and alkaline degreasing mixed with surfactant, kerosene, triethanolamine and sodium hydroxide.

  The aluminum plate used in the present invention is subjected to a surface roughening treatment in order to improve the adhesion to the image forming layer and improve the water retention. The roughening treatment method includes mechanical treatment, chemical treatment, and electrochemical treatment. These treatments are carried out alone or in combination, but it is particularly preferable to combine mechanical polishing in view of cost. The shape of the surface is generally represented by a roughness meter, and its size is suitably a center line average roughness; Ra value of 0.3 to 1.0 μm.

  A ball grain method, a nylon brush method, a buff polishing method, a blast polishing method, or the like can be used as the mechanical surface roughening treatment. Chemical roughening includes a method of chemically dissolving aluminum with chloride, fluoride or the like.

  The electrochemical roughening treatment method is preferably used because it can finely control the shape and surface roughness of the grain according to the electrolyte composition and electrolysis conditions as compared with other methods. The electrochemical surface roughening treatment can be performed by direct current, alternating current or a combination of both. Examples of the AC wave include a single-phase or three-phase commercial AC, or a sine wave, a rectangular wave, a trapezoidal wave, etc. in the range of 10 to 300 Hz including these.

The electric power supplied to the aluminum plate varies depending on the composition of the electrolytic solution, the temperature, the distance between the electrodes, etc., but in order to obtain a suitable grain for a printing plate, generally 1 to 60 A / dm ² for current and 50 for electric quantity. Used in the range of ~ 4000C. The distance between the electrode and the aluminum plate is preferably in the range of 1 to 10 cm.

  As the electrolytic solution, nitric acid or a salt thereof, hydrochloric acid or a salt thereof, or an aqueous solution of one kind or a mixture of two or more kinds thereof can be used. In addition, sulfuric acid, phosphoric acid, chromic acid, boric acid, organic acids or their salts, ammonium salts, amines, surfactants, other corrosion inhibitors, corrosion accelerators, and stabilizers are added as necessary. You can also

  The concentration of the electrolytic solution is preferably from 0.1 to 10% by mass, and the concentration of aluminum ions in the electrolytic solution is maintained in the range of 0 to 10 g / L. The temperature of the electrolytic solution is preferably 0 to 60 ° C.

  In the present invention, it is preferable to perform a desmut treatment between the roughening treatment and the anodizing treatment. Desmutting refers to a chemical etching process performed between roughening and anodizing. Desmutting can be performed using an acid or an alkali, but acid treatment is preferred. As the acid, nitric acid, phosphoric acid, chromic acid, sulfuric acid, hydrochloric acid, hydrofluoric acid and the like can be used alone or in combination. As the alkali desmut, sodium hydroxide, sodium carbonate, potassium hydroxide, potassium carbonate, tribasic potassium phosphate, sodium aluminate, sodium silicate and the like can be used alone or in combination. In addition, the concentration of the desmut solution and the treatment time must be such that the smut can be completely removed. Since the amount of smut generated depends on the roughening treatment method in the previous stage, the required degree of desmutting depends on the roughening method. However, since the degree of removal of the smut can be easily observed with a scanning microscope, the degree of desmut from which the smut is completely removed can be easily determined by observing the surface of the treated aluminum. Actually, there is a relationship with the treatment of waste liquid, and the total of acid or alkali is about 5 to 40%, and the treatment time is preferably 30 seconds to 2 minutes. The treatment temperature is preferably 40-60 ° C.

  In the present invention, the desmutting step can be divided into two or more times. In this case, it is possible to combine an acid desmut and an alkali desmut, but it is preferable to use the alkali desmut first.

  After performing such roughening treatment and desmut treatment, anodization treatment is performed. As the electrolytic solution for anodic oxidation, sulfuric acid, phosphoric acid, oxalic acid, chromic acid, organic acid (for example, sulfamic acid, benzenesulfonic acid, etc.) or a mixture thereof is preferable, and an acid with low solubility of the generated oxide film is particularly preferable. .

Since the anodic oxide film is formed only on the anode, a direct current is usually used. As anodizing conditions, the liquid concentration is 1 to 40%, the current density is 0.1 to 10 A / dm ² , and the voltage is 10 to 100V. The thickness of the anodic oxide film is changed by the current density and time, it is adjusted appropriately by printing grade of the printing plate, 3 g / m ² or less, preferably ^{2.8g / m 2 ~1g / m 2} , more preferably preferably the 2.3g / m ² ~1g / m ² required. The temperature affects the hardness of the anodic oxide film, and the hardness is high at low temperatures, but is inferior in flexibility and is usually processed at a temperature near room temperature. The amount of these anodized films can be measured based on JIS H86807 “film mass method”.

  Further, after the anodizing treatment, a post-treatment can be performed as necessary. As the post-treatment, methods known to those skilled in the art, for example, post-treatment with inorganic salts such as silicate treatment and hydrofluoric zirconate treatment, organic polymer treatment such as gum arabic, polyvinyl phosphonic acid and polyvinyl sulfonic acid, hydration There is a sealing treatment.

  The lithographic printing plate material of the present invention is provided with a conductive layer, an antistatic layer, a curl prevention layer for preventing curling of the support, a curl accelerating layer for imparting a desired curl, etc., if necessary, in addition to the image forming layer. Can do.

  The composition containing the crosslinking agent used in the present invention contains a crosslinking agent for the primary amine polymer. The crosslinking reaction itself is mechanically the same as the crosslinking reaction for lysine, which is a primary amine. Accordingly, the amount of monomer units in the polymer is small and not included in the present invention, but is a crosslinking agent for gelatin containing lysine and reacting with this lysine, such as “The theory of Photographic Process” 4th edition (Eastman Kodak Company). (1977 TH James)) The amine crosslinking agent described in Chapter 2 can be used. Specific examples of the crosslinking agent include, for example, formaldehyde, N-methylol compounds (for example, N-methylol urea, N-methylol melamine, N-methylol ethylene urea, and initial contractions thereof), dialdehydes (for example, glyoxal, glutaraldehyde). , Succinaldehyde etc.), various epoxy compounds (eg glycerol polyglycidyl ether, sorbitol polyglycidyl ether), activated vinyl compounds (eg bis (vinylsulfonyl) methane, bis (vinylsulfonylmethyl) ether etc.), quinones (eg p-quinone etc.), s-triazine (eg 2,4-dichloro-6-hydroxy-striazine etc.) and the like. Among these, it is preferable to use formaldehyde, dialdehydes, and epoxy compounds.

  The cross-linking agent in the composition containing the cross-linking agent in the present invention can be used alone or dissolved in an aqueous solution or alcohol solution, or can be used after being solubilized with a surfactant such as polyoxyethylene nonylphenol ether. If the viscosity is not set to 20 mPa · s or less, preferably 5 mPa · s or less, and more preferably 2 mPa · s or less, the ink jet nozzle is clogged. The preferred concentration of the crosslinking agent varies depending on the kind of the crosslinking agent from the viewpoint of storage stability and viscosity, but is generally 0.1 to 40% by mass, more preferably 1 to 15%.

  The composition containing a cross-linking agent used in the present invention includes a volatilization inhibitor, if necessary, in order to suppress evaporation of the ink solvent in the ink jet nozzle and prevent clogging of the nozzle due to precipitation of dissolved components. Is added. Specific examples include dihydric alcohols such as ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, dipropylene glycol, and polyethylene glycol, trihydric alcohols such as glycerin, and polyhydric alcohols. Glycerin is particularly preferred. Two or more of these polyhydric alcohols may be used in combination. The volatilization inhibitor is used in the composition containing the photopolymerizable crosslinking agent of the present invention in an amount ranging from 0.5 to 40% by mass, preferably from 1 to 20% by mass. When the content of the volatilization inhibitor is less than 0.5% by mass, a sufficient volatilization prevention effect may not be obtained. If it exceeds 40% by mass, the physical properties of the composition containing the photopolymerizable crosslinking agent after curing are lowered, so that the obtained printing plate is inferior in printing durability.

  In order to adjust the surface tension of the composition containing the crosslinking agent so as to adjust the size of the droplets of the composition containing the crosslinking agent ejected from the ink jet nozzle so that a high-resolution image area is formed, or the support In order to prevent bleeding and repellency that may occur when the image area is formed on the surface, a surfactant may be further added to the composition containing the crosslinking agent of the present invention. The surfactant may be any surfactant that can arbitrarily adjust the surface tension of the composition containing the crosslinking agent, and is not limited to any one of nonionic, cationic, and anionic. However, when a continuous jet type is used as an inkjet image forming apparatus, a composition containing a cross-linking agent is charged at the tip of an inkjet nozzle, and the charged ink droplet is forced to pass through the formed electric field. Therefore, it is preferable to use a nonionic surfactant.

  Examples of such surfactants include polyethylene glycol lauryl ether, polyethylene glycol alkyl ether or alkyl phenyl ether such as polyethylene glycol nonyl phenyl ether, fatty acid diethanolamide, sodium alkyl naphthalene sulfonate, polyethylene glycol nonyl phenyl ether sulfate, Polyethylene glycol lauryl ether triethanolamine sulfate, polyethylene glycol alkyl ether or alkyl phenyl ether phosphate, or combinations thereof are used. The amount of these surfactants contained in the composition containing the crosslinking agent is sufficiently effective when the content is 0.1% by mass or more, and even if the content is increased, the surface tension does not fall below a certain value. Therefore, about 5 mass% is suitable.

  The composition containing a crosslinking agent in the present invention preferably contains a pigment or a dye in order to facilitate plate inspection after image formation by inkjet. As the dye used in the present invention, known dyes such as acid dyes, direct dyes, basic dyes and reactive dyes described in the color index can be used. As the pigment, known pigments such as those described in JP-A-6-16983 can be used. The amount of these dyes and pigments used is not particularly limited, but generally a range of 0.1 to 15% by mass with respect to the total weight of the ink is preferable, and more preferably 0.1 to 15% by mass. 10% by mass.

  In the present invention, it is preferable that the plate is heat-treated after image printing by the ink jet method. The heating temperature is 50 to 120 ° C., preferably 80 to 120 ° C., and the time is heated for several seconds to several minutes, preferably 5 to 30 seconds. Gases and the like may be generated with heating, and it is preferable to take necessary measures such as exhausting the heated portion and destroying harmful exhaust gas with a photocatalyst or the like.

  In the present invention, the water-soluble polymer in the non-image area can be removed by washing the planographic printing plate with water before printing after image printing by the inkjet method. The washing treatment is achieved by using a method of spraying a washing solution of 25 to 35 ° C. by a jet method or a method of peeling an emulsion layer with a scrub roller while spraying the washing solution. The washing solution may always be poured with fresh water, or it may be circulated using pumped water. In the latter case, it is preferable to contain an antifoaming agent, a precipitating agent, etc. in the water washing solution and to circulate and reuse the washing water while filtering it with a filter or the like.

  The non-image area exposed by the water washing treatment is preferably subjected to a treatment with a finishing solution in order to increase the hydrophilicity of each and to protect the plate surface. In the present invention, the finishing solution contains arabic gum, dextrin, sodium alginate, propylene glycol ester of alginic acid, hydroxyethyl starch, carboxymethylcellulose, hydroxyethylcellulose, polyvinyl for the purpose of protecting the anodized layer in the non-image area and improving hydrophilicity. It is preferable to contain protective colloids such as pyrrolidone, polystyrene sulfonic acid, and polyvinyl alcohol.

  Even if the non-image portion is not eluted before printing in the present invention, on-press plate-making is performed using the methods described in JP-A-2004-322511, JP-A-2004-223833, and JP-A-2004-284223. You can also.

  EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples. In addition,% shows the mass% unless there is a notice.

A 1050 aluminum plate is degreased with a 4% aqueous sodium hydroxide solution at 50 ° C. for 1 minute, washed with water, then polished with a rotating nylon brush using a 400 mesh pumiston suspension, and a 2.5% aqueous hydrochloric acid solution. Electrolytic surface roughening treatment was performed for 60 seconds at an AC density of 50 A / dm ² at 20 ° C., and desmutted with 20% phosphoric acid at 50 ° C. for 1 minute. Thereafter, an anodization treatment was performed in a 25% sulfuric acid solution at a temperature of 20 ° C., a current density of 3 A / dm ² , and a treatment time of 45 seconds to produce an aluminum support. As shown in Table 1, the following image forming layer was applied to the anodized surface and dried to prepare a lithographic printing plate. An attempt was made to prepare a sample of polyallylamine PAA10C alone, but no film could be formed.

<Image forming layer A>
PVA235 (polyvinyl alcohol: manufactured by Kuraray Co., Ltd .: solid content) 1.2 g / m ²
PAA10C (polyallylamine: manufactured by Nitto Boseki Co., Ltd .: solid content) 0.3 g / m ²
Smartex PA 9281 (SBR latex: manufactured by Japan A & L Co., Ltd .: aqueous dispersion)
1.0 g / m ²

<Image forming layer B>
Alkali-treated gelatin (Nippi Gelatin Co., Ltd .: solid content) 1.2 g / m ²
PAA10C 0.3g / m ²
Smartex PA 9281 1.0 g / m ²

<Image forming layer C>
PVPK90 (polyvinylpyrrolidone: made by ISP Co., Ltd .: solid content) 1.2 g / m ²
PAA10C 0.3g / m ²
Smartex PA 9281 1.0 g / m ²

<Image forming layer D>
Chitosan (manufactured by Kimitsu Chemical Co., Ltd .: solid content) 1.5 g / m ²
Smartex PA 9281 1.0 g / m ²

<Image forming layer E>
PAA-D11 (polyallylamine / polydiallylamine copolymer: manufactured by Nittobo Co., Ltd .: solid content) 0.3 g / m ²
PVA235 1.2 g / m ²
Smartex PA 9281 1.0 g / m ²

<Image forming layer F>
PAS-92 (Polydiallylamine / Sulfur Dioxide heavy product: Nitto Boseki Co., Ltd .: solid content)
1.5 g / m ²
Smartex PA 9281 1.0 g / m ²

<Image forming layer G>
PVA235 1.5 g / m ²
Smartex PA 9281 1.0 g / m ²

<Image forming layer H>
Gelatin 1.5g / m ²
Smartex PA 9281 1.0 g / m ²

  Using PM-700C manufactured by Seiko Epson Corporation as an ink jet printer, the ink was refilled with a composition containing the following crosslinked product, and an image was printed on the resulting lithographic printing plate. After printing, the sample was placed in a dryer heated to 120 ° C. for 10 seconds and heat-treated, and then a printing test was conducted with a HAMADAH234c printer. The dampening solution used was a 2% aqueous solution of Astro Mark III (manufactured by Nikken Chemical Co., Ltd.), and the ink used was Value G cyan H type (manufactured by Dainippon Ink & Chemicals, Inc.).

<Composition I containing a crosslinking agent>
Glyoxal (40% aqueous solution) 25g
Glycerin 2g
Nissan Nonion K-230 (Surfactant: manufactured by NOF Corporation) 5g
Food color blue 1 0.1g
Dissolved in water to 100 g.

<Composition B containing a crosslinking agent>
Glutaraldehyde (25% aqueous solution) 40g
Glycerin 2g
Nissan Nonion K-230 5g
Food color blue 1 0.1g
Dissolved in water to 100 g.

<Composition C containing a crosslinking agent>
Denacol EX313 (epoxy compound: manufactured by Nagase ChemteX Corporation) 10g
Glycerin 2g
Nissan Nonion K-230 5g
Food color blue 1 0.1g
Dissolved in water to 100 g.

<Composition containing cross-linking agent>
Denacol EX614 (epoxy compound: manufactured by Nagase ChemteX Corporation) 10g
Glycerin 2g
Nissan Nonion K-230 5g
Dissolve in ethanol to 100 g.

<Composition E with Crosslinking Agent>
Bis (vinylsulfonyl) propanol 10g
Glycerin 2g
Nissan Nonion K-230 5g
Food color blue 1 0.1g
Dissolved in water to 100 g.

<To composition containing crosslinking agent>
2,4-dichloro-6-hydroxy-striazine 10 g
Glycerin 2g
Nissan Nonion K-230 5g
Food color blue 1 0.1g
Dissolved in water to 100 g.

<Composition containing a crosslinking agent>
Aluminum sulfate 14-18 hydrate) 10g
Glycerin 2g
Nissan Nonion K-230 5g
Food color blue 1 0.1g
Dissolved in water to 100 g.

  The results are shown in Table 2. As for blur, after printing with IJ, the image portion was markedly blurred by x, slightly blurred by Δ, and completely unmarked by ○. The image quality was evaluated by the width of the thinnest negative-positive thin line that can be reproduced on the 100th printed sheet. The printing durability was evaluated based on the number of sheets where blurring occurred in the image area.

  From Table 2, it can be seen that the use of the primary amine polymer in the image forming layer provides good printing durability and image quality, and further better use of polyallylamine. Particularly preferred image quality was obtained when dialdehydes and epoxies were used as the crosslinking agent.

  Similar to Example 1 except that the plates 1 to 5 of Example 1 were used, and the composition containing the crosslinking agent of Example 1 was used as the composition containing the crosslinking agent, and no post-printing heat treatment was performed by the ink jet method. As a result, the results shown in Table 3 below were obtained. Comparing the results shown in Table 3 with Example 1, it can be seen that better heat resistance and image quality can be obtained with heat treatment.

Claims (1)

Lithographic printing characterized in that an image is formed by printing a composition containing a crosslinking agent for polyallylamine on a lithographic printing plate having a layer containing at least one polyallylamine on a support using an ink jet method. Plate making method.