JP2001272787A - Image forming material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a negative type image forming material capable of direct recording from digital data of a computer or the like by recording with IR laser and capable of giving a planographic printing plate excellent in image forming property and printing resistance. SOLUTION: The image forming material is obtained by successively disposing a silicate coating, a middle layer containing a silicone compound having a functional group capable of causing an addition reaction under a radical and a photosensitive layer containing (A) an IR absorbent, (B) a radical generating agent, (C) a radical polymerizable compound and (D) a binder polymer on an aluminum base. The middle layer may be disposed by bonding the addition reactive functional group to the surface of the aluminum substrate using the organic silicone compound.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a so-called direct plate-making negative type image forming material which can directly make a plate by scanning an infrared laser based on a digital signal from a computer or the like.

[0002]

2. Description of the Related Art Heretofore, as a system for directly making a plate from digital data of a computer, an electrophotographic system, a photopolymerization system for exposing with a laser emitting blue or green light, and a silver salt on a photosensitive resin are known. Laminated ones, silver salt diffusion transfer methods, and the like have been proposed.

However, in the case of using the electrophotographic method, the processes of image formation such as charging, exposure, and development are complicated, and the apparatus is complicated and large. In the case of the photopolymerization system, since a plate material having high sensitivity to blue or green light is used, handling in a bright room becomes difficult. The methods (1) and (2) have drawbacks in that processing such as development becomes complicated because silver salts are used, and silver is contained in the processing waste liquid.

On the other hand, the development of lasers in recent years has been remarkable, and in particular, solid-state lasers and semiconductor lasers that emit infrared light having a wavelength of 760 nm to 1200 nm have become easily available with high output and small size. These lasers are very useful as a recording light source when making a plate directly from digital data of a computer or the like. However, many photosensitive recording materials that are practically useful have a photosensitive wavelength in the visible light range of 760 nm or less, and therefore cannot record images with these infrared lasers. Therefore, a material that can be recorded by an infrared laser is desired.

As an image recording material recordable by such an infrared laser, there is a recording material comprising an onium salt, a phenol resin and a spectral sensitizer described in US Pat. No. 4,708,925. This image recording material is a positive type image recording material utilizing the effect of suppressing dissolution in a developer, which is exhibited by an onium salt and a phenol resin, and is not a negative type as in the present invention. On the other hand, as a negative type image recording material, a recording material comprising an infrared absorber, an acid generator, a resol resin and a novolak resin is disclosed in US Pat.
0,699. However, such a negative type image recording material requires a heat treatment of heating at 140 to 200 ° C. for about 50 to 120 seconds after laser exposure in order to form an image. It required extensive equipment and energy.
For example, JP-A-8-108621 discloses a negative-type image forming material using a photopolymerizable composition. Here, in order to promote thermal polymerization of a recording layer, heating is performed simultaneously with image exposure. There is a statement to the effect. Simultaneous heating in the exposure process has problems such as heating giving thermal fluctuations to the nearby air, blurring the laser focus, affecting image forming properties, and shortening the life of the laser element due to heat. Is not preferred.

Japanese Patent Publication No. 7-103171 discloses a heat treatment after imagewise exposure comprising a cyanine dye having a specific structure, an iodonium salt and an addition-polymerizable compound having an ethylenically unsaturated double bond. Although a recording material that is not required is described, this image recording material has a problem that polymerization is inhibited by oxygen in the air during a polymerization reaction, resulting in a decrease in sensitivity and an insufficient strength of a formed image portion. was there.

[0007]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to record directly using digital data from a computer or the like by recording using a solid-state laser or a semiconductor laser that emits infrared rays. An object of the present invention is to provide a negative image forming material capable of obtaining a lithographic printing plate having excellent printing durability.

[0008]

Means for Solving the Problems The present inventor paid attention to the physical properties of a negative-type image forming material, and as a result of intensive studies, formed a specific intermediate layer between a support and a photosensitive layer for image formation. The present invention has been found to be able to solve the problem, and the present invention has been completed. That is, the negative-type image forming material of the present invention can be recorded with an infrared laser, has a silicate film on an aluminum support, an intermediate layer containing a silicone compound having a functional group capable of causing an addition reaction by radicals, (A) A photosensitive layer containing an infrared absorber, (B) a radical generator, (C) a radical polymerizable compound, and (D) a binder polymer is sequentially provided.

Although the function of the present invention is not clear, an intermediate layer containing a silicone compound having a functional group capable of causing an addition reaction by radicals after forming an anodic oxide film or a silicate film on an aluminum support by a conventional method. By forming, a thin film having the function of a heat insulating layer is formed between the aluminum support having high thermal conductivity and the photosensitive layer, and the heat generated by the exposure is efficiently used for the curing reaction of the exposed portion. A silicone compound having a functional group capable of causing an addition reaction contained in the intermediate layer and having a functional group capable of causing an addition reaction, and a radical polymerizable compound in the photosensitive layer are formed. Are strongly bound by the interaction and contribute to the improvement of the adhesion of the image area, ie, the printing durability.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The image forming material of the present invention is obtained by subjecting an aluminum substrate to a known surface treatment such as anodic oxidation treatment, forming a silicate film and hydrophilizing the functional group, which can cause an addition reaction by radicals. Characterized in that a photosensitive layer is formed via an intermediate layer containing a silicone compound having the following formula: Before forming this intermediate layer, it is preferable to use an aluminum support which has been subjected to a surface treatment such as a general anodic oxidation treatment on an aluminum substrate and then subjected to a hydrophilization treatment by a silicate treatment. The method of adjusting is briefly described.

[Support] The negative-working image forming material according to the method of the present invention is formed by coating the photosensitive layer on a support. The support that can be used here is not particularly limited as long as it is a dimensionally stable plate-like material. For example, paper, plastic (eg, polyethylene, polypropylene, polystyrene, etc.) laminated paper, metal plate ( For example, aluminum, zinc, copper, etc.), plastic film (for example, cellulose diacetate, cellulose triacetate, cellulose propionate, cellulose butyrate, cellulose acetate butyrate,
Examples thereof include cellulose nitrate, polyethylene terephthalate, polyethylene, polystyrene, polypropylene, polycarbonate, polyvinyl acetal, etc.), and paper or plastic films on which the above-mentioned metals are laminated or vapor-deposited. Preferred supports include a polyester film or an aluminum plate.

As the support used in the image forming material of the present invention, it is preferable to use an aluminum plate which is lightweight and has excellent surface treatment properties, workability and corrosion resistance. Aluminum materials used for this purpose include JIS 1050
Material, JIS 1100 material, JIS 1070 material, Al-
Mg-based alloy, Al-Mn-based alloy, Al-Mn-Mg-based alloy, Al-Zr-based alloy. Al-Mg-Si alloys and the like can be mentioned.

The preferred aluminum plate is a pure aluminum plate or the above-mentioned alloy plate containing aluminum as a main component and a trace amount of a different element, and may be a plastic film on which aluminum is laminated or vapor-deposited. The foreign elements contained in the aluminum alloy include silicon,
There are iron, manganese, copper, magnesium, chromium, zinc, bismuth, nickel and titanium. The content of the foreign element in the alloy is 10% by weight or less. As the aluminum plate, pure aluminum is preferable. However, since pure aluminum is difficult to produce due to refining technology, it may contain a slightly different element. As described above, the composition of the aluminum plate is not specified, and an aluminum plate of a conventionally known and used material can be appropriately used. The thickness of the aluminum plate is preferably about 0.1 to 0.6 mm, and 0.15 to 0.4 mm.
mm is more preferable, and 0.2 to 0.3 mm is particularly preferable.

Prior to roughening the aluminum plate, if necessary, a degreasing treatment with, for example, a surfactant, an organic solvent or an alkaline aqueous solution is performed to remove rolling oil on the surface. The surface roughening treatment of the surface of the aluminum plate is performed by various methods, for example, a method of mechanically roughening the surface, a method of electrochemically dissolving the surface, and a method of selectively dissolving the surface chemically. It is performed by the method of causing. Known mechanical methods such as a ball polishing method, a brush polishing method, a blast polishing method, and a buff polishing method can be used as the mechanical method. Further, as an electrochemical surface roughening method, there is a method of performing an alternating or direct current in a hydrochloric acid or nitric acid electrolyte.

[0015] The aluminum plate thus roughened is
Alkaline etching treatment and neutralization treatment as necessary
After removal, if necessary, the water retention and abrasion resistance of the surface can be increased.
Anodizing treatment is performed for the purpose. Anodizing, by anodizing
1.0 g / m ^TwoThe above is preferred. Anodic acid
1.0 g / m^TwoIf less than, press life
Is insufficient or used as a lithographic printing plate
Indicates that the non-image area is easily scratched and
So-called "scratch stain" that ink adheres to the surface
Sometimes. After being subjected to the anodizing treatment,
The surface of the minium is subjected to a hydrophilization treatment described in detail below.
It is.

Further, such an aluminum support is treated with an organic acid or a salt thereof after anodizing treatment, or
An undercoat layer applied to a photosensitive layer can be applied for use.

After the above-mentioned treatment or undercoating is applied to the surface of the support, a back coat is provided on the back surface of the support, if necessary. As such a back coat, a coating layer comprising a metal oxide obtained by hydrolysis and polycondensation of an organic polymer compound described in JP-A-5-45885 and an organic or inorganic metal compound described in JP-A-6-35174 is used. It is preferably used.

The preferred characteristics of the lithographic printing plate support are center line average roughness of 0.10 to 1.2 μm. If it is less than 0.10 μm, the adhesion to the photosensitive layer is reduced,
Significant reduction in printing durability occurs. If it is larger than 1.2 μm, the stain on printing will be deteriorated. Further, the color density of the support is 0.15 to 0.5 as a reflection density value.
65, and when it is whiter than 0.15, the halation at the time of image exposure is too strong and hinders image formation.
When it is darker than 0.65, the image is difficult to see in the plate inspection work after development, and the plate inspection property is extremely poor.

Here, the hydrophilizing treatment performed after the anodic oxidation treatment is described. Hydrophilic treatment in the present invention is the formation of a silicate coating, silicate coating to 40 mg / m ² as a Si element content, more preferably 4 to 30 mg / m ² formed. The coating amount can be measured by fluorescent X-ray analysis, and the Si element amount can be measured. The above-mentioned hydrophilization treatment is performed, for example, in US Pat.
No. 714,066, No. 3,181,461, No. 3,2
The alkali metal silicate (for example, sodium silicate aqueous solution) method disclosed in JP-A-80,734 and JP-A-3,902,734 can be applied. According to this method, the alkali metal silicate is 1 to 30% by weight, preferably 2 to 15% by weight, and the pH at 25 ° C is 10 to 10% by weight.
The aluminum substrate on which the anodized film is formed is immersed in the aqueous solution of No. 13 at, for example, 15 to 80 ° C. for 0.5 to 120 seconds.

As the alkali metal silicate used in the present invention, sodium silicate, potassium silicate, lithium silicate and the like are used. Hydroxides used to increase the pH of the aqueous alkali metal silicate solution include sodium hydroxide, potassium hydroxide and lithium hydroxide.
In addition, alkaline earth metal salts or IV
A group B metal salt may be blended. Alkaline earth metal salts include nitrates such as calcium nitrate, strontium nitrate, magnesium nitrate and barium nitrate, and water-soluble salts such as sulfates, hydrochlorides, phosphates, acetates, oxalates and borates. No. Group IVB metal salts include titanium tetrachloride, titanium trichloride, potassium titanium fluoride, titanium potassium oxalate, titanium sulfate, titanium tetraiodide, zirconium chloride, zirconium dioxide, zirconium oxychloride, zirconium tetrachloride and the like. Can be. Alkaline earth metal salts or Group IVB metal salts can be used alone or in combination of two or more. The preferred range of these metal salts is 0.01 to 10% by weight, and the more preferred range is 0.05 to 5.0% by weight.

An intermediate layer containing a silicone compound having a functional group capable of causing an addition reaction by radicals (hereinafter referred to as an addition-reactive functional group) is formed on the Al support subjected to such a hydrophilic treatment. However, the formation of the intermediate layer is preferably performed by a method of preparing an intermediate layer coating solution using an organic silicone compound as a raw material and coating the intermediate layer with the support. Specifically, when the addition-reactive functional group is represented by R ¹ , treating an aluminum substrate with an organic silicone compound represented by the following formula (1) (hereinafter referred to as an organic silicone compound (1)): The metal, metal oxide, hydroxide, -OH on the substrate surface
By reacting with a group or a silanol group formed by chemical conversion treatment of the substrate to form a covalent bond with the substrate surface, a functional group represented by the following formula (2) may be bonded (or implanted) to the substrate surface. . R ¹ Si (OR ² ) ₃ (1) wherein —OR ² is a hydrolyzable alkoxy group or —O
Represents a COCH ₃ group.

[0022]

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In the formula, R ³ represents the same or different alkyl group or hydrogen atom as R ² , or a bond to another adjacent Si atom. In the above, the addition reactive functional group (R
¹ ) wherein at least two Si atoms are bonded to the central Si atom,
The organic silicone compounds (1a) and (1b) represented by a) or (1b) can also be used.

[0024]

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Further, when the addition-reactive functional group (R ¹ ) is —O—
When the functional group is bonded to the central Si atom via
Can also be used.

[0026]

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The organic silicone compound (1) has
It is applied to the aluminum substrate when at least one of the four R ¹ bonded to the i atom remains without being hydrolyzed. When the organic silicone compound (1) is applied on an aluminum substrate, it may be used alone or may be used after being diluted with a suitable solvent. Water and / or a catalyst can be added to bind the organosilicone compound (1) more firmly on the aluminum substrate. As the solvent, alcohols such as methanol, ethanol, propanol, isopropanol, ethylene glycol, and hexylene glycol are preferable.As the catalyst, acids such as hydrochloric acid, acetic acid, phosphoric acid, and sulfuric acid, or ammonia, and tetramethylammonium hydroxide and the like Bases can be used.

The amount of addition-reactive functional groups on the aluminum substrate varies depending on the type of addition-reactive functional group to be bonded, ² per generally 0.01 to 400 pieces 100 Å, preferably from 0.05 to 40, still Preferably, it is appropriate to set the number to 0.1 to 5. The amount of the addition reactive functional group is 100
と If the number is less than 0.01 per ^2, it is difficult to obtain a sufficient optical adhesive strength. Organic silicone compounds by overlaying thick painted (1), the amount of addition-reactive functional groups per 100 Å ² is capable of many substantially much additional partake in the reaction exposed on the outermost surface The amount of reactive functional groups is 10
Because it is 0Å ² per sales people 10 or so, wasted will only increase the functional groups which do not participate in the function improved too coating thick. Here, in order to prevent a phenomenon that the hydrophilicity of the non-image portion becomes insufficient when used as a lithographic printing plate after image formation due to an excessive amount of the addition-reactive functional group,
量 The amount of the addition-reactive functional group per ² is preferably 400 or less.

Accordingly, when an addition-reactive functional group is bonded (planted) to the aluminum substrate surface using an organic silicone compound and an intermediate layer is formed, the type and amount of a solvent for diluting the organic silicone compound, the substrate surface The amount of water to add for hydrolysis above (if any), the type and amount of catalyst to promote hydrolysis on the substrate surface (if any),
A method of applying a solution of an organic silicone compound on a substrate,
The process parameters such as the drying atmosphere, the drying temperature, and the drying time after being applied to the substrate are variously changed, and the amount of the addition-reactive functional group retained on the substrate surface can be controlled to be within the above range. is necessary. The amount of the addition-reactive functional group retained on the aluminum substrate surface is measured by an appropriate method such as a fluorescent X-ray analysis method or an infrared absorption method on the substrate surface after the treatment, and the amount of the Si atom on the surface is determined. It can be determined by performing quantification, quantification of the amount of carbon-carbon multiple bonds, and the like.

An anodic oxide film and a silicate film are formed on an aluminum substrate as described above, and an additional reactive functional group is bonded to the surface of the anodic oxide film and the silicate film to form an intermediate layer. When an image forming material is formed using a support having such an intermediate layer formed thereon, when only the organosilicone compound of the above formula (1) is used, printing smear may occur. This means that the organic functional groups of the organosilicone compound are exposed on the surface of the unexposed portion (which becomes a hydrophilic ink-repellent area) after the photosensitive layer is removed with a developer, and these organic functional groups are exposed. It is considered that due to the influence of the ink, the ink easily adheres in addition to the water. Therefore, in order to suppress the influence of such organic functional groups and increase the hydrophilicity, it is necessary to fix a large number of OH groups in addition to the addition-reactive functional groups (R ¹ ) to enhance the hydrophilicity. preferable. Preferably, in addition of the organosilicone compound (1) [R ¹ Si (OR ² ) ₃ ] represented by the formula (1), the addition of the addition-reactive functional group to the surface of the aluminum substrate is represented by the following formula (3). It is preferred that the organic silicone compound represented by the formula (2) is used in combination to bind the reaction site represented by the formula (2) to the substrate surface and, at the same time, bind the hydrophilic site represented by the following formula (4). Si (OR ⁴ ) ₄ (3) wherein —OR ⁴ is a hydrolyzable alkoxy group, alkoxyalkoxy group, aryloxy group or —OCOCH
_{There are three} . R ⁴ may be the same as or different from R ² in the organic silicone compound (1) used in combination.

[0031]

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Here, in the formula (4), R ³ is an alkyl group,
It represents a hydrogen atom or a bond with another adjacent Si atom, and it is most preferable that R ³ is a hydrogen atom from the viewpoint of hydrophilicity. When R ³ is other than a hydrogen atom,
If necessary, the hydrophilicity can be increased by washing the surface with an alkaline solution.

The mixing ratio of the organosilicone compound (1) represented by the formula (1) and the organosilicone compound (3) represented by the formula (3) depends on the properties of the support and the surface of the support. Since the efficiency of binding (planting) to the fluctuates, a suitable range cannot be determined. However, specifically, the support is treated by changing the ratio of the two, and the photo-adhesion based on the addition-reactive functional group R ¹ and the hydrophilicity derived from the partial structure represented by the formula (4) are obtained. Are determined experimentally and used. In any case, the density of the addition-reactive functional group should be within the above range. Specifically, the mixing molar ratio of the organosilicone compound (3) to the organosilicone compound (1) is suitably from 0.05 to 200, preferably from 0.1 to 200.
It is 2-100, more preferably 1-40. Further, within this range, as the amount of the hydrophilic group derived from the organic silicone compound (3) increases, the hydrophilicity of the non-image portion increases. However, even when the density of the hydrophilic group is low, as described above, the density of the hydrophilic group is obtained by hydrophilizing the addition-reactive functional group such as treating the surface of the formed coating film with an alkaline solution. Can be improved.

The bonding of the addition-reactive functional group to the surface of the aluminum substrate to form the intermediate layer according to the present invention can be roughly classified into the above-described methods (hereinafter, referred to as SC method) using an organic silicone compound as it is. In addition, an organic-inorganic composite in which an addition-reactive functional group is fixed to an inorganic polymer having a -Si-O-Si- bond obtained by hydrolyzing and polycondensing an organic silicone compound. (Hereinafter referred to as SG method). When this organic-inorganic composite is applied to an aluminum substrate and dried, the inorganic polymer portion adheres to the substrate, and the addition-reactive functional group remains on the substrate surface as it is.

In the case of the SC method, the bonding position of the addition-reactive functional group on the surface of the aluminum substrate tends to be a position having a specific property on the substrate surface, and it may be difficult to uniformly distribute the functional group on the surface of the substrate. is there. That is, a covalent bond with the Si atom is formed only at a specific acid point or base point, and the distribution of the addition-reactive functional group is likely to be controlled by the distribution of acid points or base points on the aluminum substrate surface. Therefore, unevenness may occur in the optical adhesive strength and the non-image area hydrophilicity. In such situations, it is advantageous to follow the SG method.

In detail, in addition to the SC method and the SG method, in addition to the intermediate methods of both methods, for example, a part or all of the —OR ² group in the organosilicone compound (1) represented by the formula (1) It is also possible to use a treatment in which an organosilicone compound in which two or three molecules are hydrolyzed and bonded is used as a starting material. According to the method of bonding the addition-reactive functional group by the SG method, the organosilicone compound (1) is optionally mixed with the organosilicone compound (3) at a desired mixing ratio, and the mixture is added in a liquid, if necessary, in the presence of a catalyst. And the addition-reactive functional group R ¹
In it causes hydrolysis at the site of -OR ² and -OR ⁴ without causing the reaction to perform the polycondensation reaction, an inorganic polymer Si atoms in the center are connected with -Si-O-Si- bonds A liquid composition containing the composition is applied to the surface of the aluminum substrate and, if necessary, dried to form an intermediate layer bonded by an addition-reactive functional group on the substrate. When the SG method is used, the distribution of the addition-reactive functional group bonded and fixed on the aluminum substrate surface is hardly influenced by the distribution of chemical properties such as acid sites and base sites on the substrate surface. When the organic silicone compound (3) is used in combination with the organic silicone compound (1) as a starting material, the addition-reactive functional group site represented by the above formula (2) and the hydrophilicity represented by the above formula (4) are used. Since the relative ratio to the site is substantially determined by the charged ratio of the organic silicone compound (1) and the compound (3), there is an advantage that the prescription for obtaining the optimum surface can be determined more easily than the SC method.

Specific examples of the organic silicone compound (1) represented by the above formula (1) used in the present invention include the following.

[0038]

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[0039]

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[0040]

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Specific examples of the organic silicone compound (3) represented by the formula (3) include tetramethoxysilane, tetraethoxysilane, tetraisopropoxysilane, tetra (n-propoxy) silane, tetra (n-butoxy) ) Silane, tetrakis (2-ethylbutoxy) silane, tetrakis (2-ethylhexyloxy) silane, tetrakis (2-methoxyethoxy) silane, tetraphenoxysilane, tetraacetoxysilane, etc., among which tetraethoxysilane is preferable. .

When the SC method is used to form the intermediate layer on the surface of the aluminum substrate, or when the SG method is used, the type of solvent, the method of applying to the substrate, and the method of drying are the same. In the case of the method, it is necessary to prepare an inorganic polymer composition having an addition reactive functional group in advance. Preferred examples are shown below. Solvents that can be used to polycondensate the organosilicone compound (1) and the organosilicone compound (3) together with hydrolysis to obtain a composition suitable for the SG method include methanol, ethanol, propanol, isopropanol, ethylene glycol, and hexylene. Alcohols such as glycols. The amount of the solvent used is generally 0.2 to 500 times, based on the total weight of the organosilicone compounds (1) and (3) used,
Preferably it is 0.5 to 50 times, more preferably 1 to 3 times. If the used amount is less than 0.2 times, the reaction solution is apt to gel over time and becomes unstable, which is not preferable. Also, 500
If it is more than twice, the reaction takes several days, which is not preferable. The amount of water added to hydrolyze the organic silicone compound is generally 0.5 to 1000 mol, preferably 1 to 100 mol, more preferably 1.5 to 10 mol, per 1 mol of the organic silicone compound. When the amount of water is less than 0.5 mol per mol of the organic silicone compound, the progress of the hydrolysis and the subsequent polycondensation reaction becomes very slow, and it takes several days for stable surface treatment to be possible. But not preferred. On the other hand, when the amount of water is
If the amount is more than 1000 moles per mole, when the resulting composition is applied to a metal surface, poor adhesion may occur, and the composition may have poor stability over time and gelate immediately, often stabilizing the coating operation. It becomes difficult to do.

The reaction temperature for preparing a composition suitable for the SG method is usually from room temperature to about 100 ° C., but depending on the type of catalyst described below, a temperature below room temperature or above 100 ° C. may be used. it can. It is also possible to carry out the reaction at a temperature higher than the boiling point of the solvent, and if necessary, a reflux condenser may be provided in the reactor. Examples of the catalyst used as necessary include acids such as hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, acetic acid, malic acid, and oxalic acid, and bases such as ammonia, tetramethylammonium hydroxide, potassium hydroxide, and sodium hydroxide. Can be used. The catalyst is added in an amount of 0.001 to 0.001 mol per mol of the organic silicone compound based on the total amount of the organic silicone compound (1) and the organic silicone compound (3) optionally added.
1 mol, preferably 0.002 to 0.7 mol, more preferably 0.003 to 0.4 mol. Add 1 catalyst
More than a mole does not have a particular economic benefit compared to its additive effect.

When a weak acid such as acetic acid or malic acid is used as a catalyst, the reaction temperature is preferably in the range of 40 ° C. to 100 ° C. However, when a strong acid such as sulfuric acid or nitric acid is used as a catalyst, The range of 10 ° C to 60 ° C is good. When phosphoric acid is used as a catalyst, the reaction can be performed at 10 ° C to 90 ° C. In the process of preparing the composition used in the SG method, and in the process of applying and drying the composition on an aluminum substrate, heat is often applied. However, when a volatile acid is used as a catalyst, the volatile acid volatilizes in peripheral devices. It may adhere and corrode it. When the present method is used in a step mainly using iron as a raw material, it is preferable to use nonvolatile sulfuric acid and / or phosphoric acid as a catalyst.

As described above, the composition comprising the organosilicone compound represented by the formulas (1) and (3), the organic solvent, water, and optionally the catalyst is mixed at an appropriate reaction temperature,
When the reaction is carried out by selecting the reaction time and, in some cases, appropriate stirring conditions, a polycondensation reaction occurs together with the hydrolysis, and Si—O
-A polymer or a colloidal polymer containing a Si bond is generated, and the viscosity of the liquid composition is increased to form a sol. When preparing a sol solution using both the organosilicone compound (1) and the organosilicone compound (3), both the organosilicone compounds may be loaded into the reaction vessel from the beginning of the reaction, or only one of them may be used for hydrolyzing. After the decomposition and polycondensation reactions have proceeded to some extent, the other organosilicone compound may be added to terminate the reaction. When the sol liquid used in the SG method is left at room temperature, the polycondensation reaction may continue to proceed and gel. Therefore, the sol liquid once prepared by the above method is diluted in advance with a solvent to be used for dilution at the time of application to an aluminum substrate, and a method of preventing or delaying the gelation of the sol liquid is adopted. You can also.

In both the SC method and the SG method, in order to bind a desired amount of an organosilicone compound or an addition-reactive functional group to a support, the organic silicone compound or an addition-reactive functional group on the support is required. It is preferable to adjust the concentration by adding a solvent before applying these treatment liquids to the support in order to eliminate the distribution unevenness of the treatment liquid. Alcohols, especially methanol, are preferred as solvents for this purpose, but other solvents, organic compounds,
Inorganic additives, surfactants and the like can also be added. Examples of other solvents include methyl ethyl ketone, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, 2-methoxyethyl acetate, 1-
Methoxy-2-propyl acetate, dimethoxyethane, methyl lactate, ethyl lactate, acetylacetone, ethylene glycol and the like can be mentioned. Examples of organic compounds that can be added include epoxy resins, acrylic resins, butyral resins, urethane resins, novolak resins, pyrogallol-acetone resins, polyvinylpyrrolidone, polyvinyl alcohol, polyvinyl methyl ether, polypropylene glycol, and the like. Examples of the inorganic additive include colloidal silica and colloidal alumina. ethylene glycol,
High-boiling solvents such as ethylene glycol monomethyl ether work to increase the stability of the solution diluted to the concentration applied to the support and ensure the reproducibility of the addition-reactive functional groups bound to the support. . Organic compounds such as a novolak resin and a pyrogallol-acetone resin have the same effect, but have a side effect of reducing the hydrophilicity of the surface of the obtained support, and it is necessary to finely adjust the addition amount.

A sol solution or a liquid composition suitable for the SG method is applied to the surface of an aluminum substrate and then air-dried or heated and dried. Covalently bond. The drying is performed to volatilize the solvent, residual water and optionally the catalyst, but the step can be omitted depending on the purpose of use of the treated substrate. Also in the SC method, this drying step has the meaning of ensuring the close contact between the organosilicone compound and the aluminum substrate in addition to the volatilization of the solvent, residual water and the like. Therefore, depending on the purpose, after the drying is completed, the temperature may be further increased and the heating may be continued. The maximum temperature in the drying and, optionally, subsequent heating is preferably in a range in which the addition-reactive functional group R ¹ does not decompose. Therefore, the drying temperature conditions that can be used are from room temperature to
The temperature is 200 ° C, preferably room temperature to 150 ° C, and more preferably room temperature to 120 ° C. Drying time is generally 30 seconds to 30
Minutes, preferably 45 seconds to 10 minutes, more preferably 1 minute
Minutes to 3 minutes. As a method of applying the liquid composition (organic silicone compound or its solution or sol solution) used in the present invention, various types such as brush coating, dip coating, atomizing, spin coating, doctor blade coating, and the like can be used. The thickness is determined in consideration of the shape of the surface of the aluminum substrate, the required film thickness to be processed, and the like.

By forming an anodized film and a silicate film on an aluminum substrate as described above, and further forming a photosensitive layer described later on a support having an intermediate layer formed thereon,
Although the image forming material of the present invention is obtained, an organic undercoat layer may be provided on the intermediate layer before coating the photosensitive layer. As the organic compound used in the organic undercoat layer, for example, carboxymethyl cellulose, dextrin, gum arabic, phosphonic acids having an amino group such as 2-aminoethylphosphonic acid, phenylphosphonic acid which may have a substituent, Organic phosphonic acids such as naphthylphosphonic acid, alkylphosphonic acid, glycerophosphonic acid, methylenediphosphonic acid and ethylenediphosphonic acid, phenylphosphoric acid which may have a substituent, naphthylphosphoric acid, alkylphosphoric acid and glycerophosphoric acid Organic phosphoric acid, organic phosphinic acid such as phenylphosphinic acid, naphthylphosphinic acid, alkylphosphinic acid and glycerophosphinic acid which may have a substituent, amino acids such as glycine and β-alanine, and hydrochloride of triethanolamine Hydroxy Although selected from such as hydrochloric acid salt of an amine having a group, it may be used as a mixture of two or more thereof.

Such an organic undercoat layer can be provided by the following method. That is, a method in which a solution obtained by dissolving the above organic compound in water or an organic solvent such as methanol, ethanol, or methyl ethyl ketone or a mixed solvent thereof is applied to an aluminum plate and dried to provide water or methanol, ethanol, methyl ethyl ketone, or the like. An aluminum substrate is immersed in a solution obtained by dissolving the above organic compound in an organic solvent or a mixed solvent thereof to adsorb the organic compound, and thereafter, washed with water or the like and dried to form an organic undercoat layer. Is the way. In the former method, 0.005 to 10% by weight of the above organic compound is used.
Can be applied in various ways. For example, any method such as bar coater coating, spin coating, spray coating, and curtain coating may be used. In the latter method, the concentration of the solution is 0.01 to 20% by weight, preferably 0.05 to 5% by weight, and the immersion temperature is 20 to 90 ° C.
Preferably, the temperature is 25 to 50 ° C., and the immersion time is 0.1 second to
20 minutes, preferably 2 seconds to 1 minute. The pH of the solution used for this can be adjusted with a basic substance such as ammonia, triethylamine, potassium hydroxide or the like, or an acidic substance such as hydrochloric acid or phosphoric acid.

The above-mentioned intermediate layer, the photosensitive layer described in detail below, and, if desired, a surface protective layer and a back coat By forming another optional layer such as a layer, the negative image forming material of the present invention can be obtained.

The photosensitive layer provided on the image forming material of the present invention comprises (A) an infrared absorber, (B) a radical generator,
It comprises (C) a radical polymerizable compound and (D) a binder polymer, and is recordable by an infrared laser. Further, it is preferable to form an overcoat layer on the photosensitive layer to prevent polymerization inhibition of the (C) radical polymerizable compound by oxygen and to protect the photosensitive layer.

Here, the photosensitive layer of this negative image forming material will be described. In such an image forming material, the (A) infrared absorbent in the exposed portion undergoes photothermal conversion by imagewise exposure with an infrared laser, and the generated heat decomposes (B) the radical generator to generate radicals. As a result, the photosensitive layer containing the (C) radical polymerizable compound and the (D) binder polymer is cured to form an image area, and the intermediate layer and the radical polymerizable compound in the photosensitive layer are firmly bonded. . Thereafter, by developing with an alkaline developer described later, the uncured unexposed photosensitive layer and the intermediate layer are removed, the hydrophilic silicate film is exposed, and a non-image portion is formed.

Each component of the photosensitive layer will be described sequentially. [(A) Infrared absorbing agent] An object of the present invention is to record an image with a laser emitting infrared rays. To this end, it is essential to use an infrared absorber. The infrared absorbent has a function of converting the absorbed infrared light into heat.
The heat generated at this time decomposes the radical generator to generate radicals. The infrared absorber used in the present invention is a dye or pigment having an absorption maximum at a wavelength of 760 nm to 1200 nm.

As the dye, commercially available dyes and known dyes described in literatures such as “Dye Handbook” (edited by The Society of Synthetic Organic Chemistry, published in 1970) can be used. Specifically, dyes such as azo dyes, metal complex salt azo dyes, pyrazolone azo dyes, naphthoquinone dyes, anthraquinone dyes, phthalocyanine dyes, carbonium dyes, quinone imine dyes, methine dyes, cyanine dyes, squarylium dyes, pyrylium salts, and metal thiolate complexes Is mentioned.

Preferred dyes include, for example, those described in
Cyanine dyes described in JP-A-8-125246, JP-A-59-84356, JP-A-59-202829, JP-A-60-78787, etc .;
No. 96, JP-A-58-181690, JP-A-58-1
No. 94595, etc., methine dyes described in
8-112793, JP-A-58-224793, JP-A-59-48187, JP-A-59-73996,
Naphthoquinone dyes described in JP-A-60-52940 and JP-A-60-63744;
Squarylium dyes described in No. 12792, etc.,
Cyanine dyes described in British Patent 434,875 and the like can be mentioned.

Further, a near infrared absorption sensitizer described in US Pat. No. 5,156,938 is preferably used, and a substituted arylbenzo (thio) described in US Pat. No. 3,881,924 is also preferable. Pyrylium salt, JP-A-57-142645
No. (U.S. Pat. No. 4,327,169) described in JP-A-58-181051, JP-A-58-220143, JP-A-59-41363, and JP-A-59-41363.
Nos. -84248, 59-84249, 59-14
Nos. 6063 and 59-146061, pyranyl compounds, cyanine dyes described in JP-A-59-216146, pentamethinethiopyrylium salts described in U.S. Pat. No. 4,283,475, and the like. Fairness 5-13
Pyrylium compounds disclosed in JP-A-514 and JP-A-5-19702 are also preferably used.

As another preferred example of the dye, US Pat. No. 4,756,993 discloses a compound represented by the formula (I):
Near-infrared absorbing dyes described as (II) can be mentioned.

Among these dyes, particularly preferred are cyanine dyes, squarylium dyes, pyrylium salts, and nickel thiolate complexes. Further, a cyanine dye is preferable, and a cyanine dye represented by the following general formula (I) is most preferable.

[0059]

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In the general formula (I), X ¹ is a halogen atom,
Or an X ² -L ^1. Here, X ² represents an oxygen atom or a sulfur atom, and L ¹ represents a hydrocarbon group having 1 to 12 carbon atoms. R ¹ and R ² each independently represent a hydrocarbon group having 1 to 12 carbon atoms. From the viewpoint of storage stability of a photosensitive layer coating liquid, R ¹ and R ² are preferably a hydrocarbon group having two or more carbon atoms, further, R ¹ and R ²
And particularly preferably combine with each other to form a 5- or 6-membered ring.

Ar ¹ and Ar ² may be the same or different and each represents an aromatic hydrocarbon group which may have a substituent. Preferred aromatic hydrocarbon groups include a benzene ring and a naphthalene ring. Preferred examples of the substituent include a hydrocarbon group having 12 or less carbon atoms, a halogen atom, and an alkoxy group having 12 or less carbon atoms. Y ¹ and Y ² may be the same or different and each represents a sulfur atom or a dialkylmethylene group having 12 or less carbon atoms. R ³ and R ⁴ may be the same or different, and represent a hydrocarbon group having 20 or less carbon atoms which may have a substituent. Preferred substituents include alkoxy groups having 12 or less carbon atoms,
Examples include a carboxyl group and a sulfo group. R ⁵ , R ⁶ , R
⁷ and R ⁸ may be the same or different,
It represents a hydrogen atom or a hydrocarbon group having 12 or less carbon atoms. From the viewpoint of availability of raw materials, a hydrogen atom is preferable. Z ^1- represents a counter anion. However, when any of R ^{1 to} R ⁸ is substituted with a sulfo group, Z ^1- is not required. Preferred Z ¹⁻ is, from the storage stability of the photosensitive layer coating solution, a halogen ion, a perchlorate ion, a tetrafluoroborate ion, a hexafluorophosphate ion,
And sulfonate ions, particularly preferably perchlorate ion, hexafluorophosphate ion and arylsulfonate ion.

In the present invention, specific examples of the cyanine dye represented by the general formula (I) which can be suitably used include paragraph [0] of Japanese Patent Application No. 11-310623.
017] to [0019].

The pigment used in the present invention includes
Commercial Pigment and Color Index (CI) Handbook,
"Latest Pigment Handbook" (edited by Japan Pigment Technical Association, 1977), "Latest Pigment Application Technology" (CMC Publishing, 1986), "Printing Ink Technology" CMC Publishing, 1984)
Can be used.

The types of pigments include black pigment, yellow pigment, orange pigment, brown pigment, red pigment, purple pigment,
Blue pigment, green pigment, fluorescent pigment, metal powder pigment, etc.
Polymer-bound dyes. Specifically, insoluble azo pigments, azo lake pigments, condensation azo pigments, chelate azo pigments, phthalocyanine pigments, anthraquinone pigments,
Perylene and perinone pigments, thioindigo pigments, quinacridone pigments, dioxazine pigments, isoindolinone pigments, quinophthalone pigments, dyeing lake pigments,
Azine pigments, nitroso pigments, nitro pigments, natural pigments, fluorescent pigments, inorganic pigments, carbon black and the like can be used.
Preferred among these pigments is carbon black.

These pigments may be used without being subjected to a surface treatment, or may be used after being subjected to a surface treatment. Examples of the surface treatment include a method of surface coating a resin or wax, a method of attaching a surfactant, and a method of bonding a reactive substance (eg, a silane coupling agent, an epoxy compound, a polyisocyanate, etc.) to the pigment surface. Can be considered. The above surface treatment methods are described in "Properties and Applications of Metallic Soap" (Koshobo),
It is described in "Printing Ink Technology" (CMC Publishing, 1984) and "Latest Pigment Application Technology" (CMC Publishing, 1986).

The particle size of the pigment is preferably in the range of 0.01 μm to 10 μm, more preferably in the range of 0.05 μm to 1 μm, and particularly preferably in the range of 0.1 μm to 1 μm.
Is preferably within the range. Pigment particle size 0.01μ
If it is less than m, the dispersion is not preferred in terms of stability in the coating solution of the image-sensitive layer.

As a method for dispersing the pigment, a known dispersion technique used in the production of ink or toner can be used. Examples of the disperser include an ultrasonic disperser, a sand mill, an attritor, a pearl mill, a super mill, a ball mill, an impeller, a disperser, a KD mill, a colloid mill, a dynatron, a three-roll mill, and a pressure kneader. For details, refer to “Latest Pigment Application Technology” (CMC Publishing, 1
986).

These infrared absorbers may be added to the same layer as other components, or may be added to another layer provided. However, when a negative image forming material is prepared, It is preferable that the optical density of the photosensitive layer at the absorption maximum in the wavelength range of 760 nm to 1200 nm is between 0.1 and 3.0. Outside of this range, sensitivity tends to decrease. Since the optical density is determined by the amount of the infrared absorbing agent added and the thickness of the recording layer, a predetermined optical density can be obtained by controlling both conditions. The optical density of the recording layer can be measured by a conventional method. As a measuring method, for example, on a transparent or white support, a coating layer after drying is formed to a recording layer having a thickness appropriately determined in a range necessary for a lithographic printing plate, and a transmission type optical densitometer is used. Examples include a method of measuring, a method of forming a recording layer on a reflective support such as aluminum, and measuring a reflection density.

[(B) Radical generator] The radical generator used in the present invention refers to a compound which is used in combination with (A) an infrared absorber and generates a radical when irradiated with an infrared laser. Examples of the radical generator include an onium salt, a triazine compound having a trihalomethyl group, a peroxide, an azo-based polymerization initiator, an azide compound, and quinonediazide. An onium salt is preferable because of its high sensitivity. The onium salt that can be suitably used as a radical polymerization initiator in the present invention will be described. Preferred onium salts include iodonium salts, diazonium salts, and sulfonium salts. In the present invention,
These onium salts function not as acid generators but as radical polymerization initiators. Onium salts suitably used in the present invention are onium salts represented by the following general formulas (III) to (V).

[0070]

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In the formula (III), Ar ¹¹ and Ar ¹² each independently represent an aryl group having 20 or less carbon atoms which may have a substituent. When the aryl group has a substituent, preferred substituents include a halogen atom, a nitro group, an alkyl group having 12 or less carbon atoms, an alkoxy group having 12 or less carbon atoms, or a 12 or less carbon atom. Aryloxy groups. Z ^11- represents a counter ion selected from the group consisting of a halogen ion, a perchlorate ion, a tetrafluoroborate ion, a hexafluorophosphate ion, and a sulfonate ion, and is preferably a perchlorate ion or a hexafluorophosphate. And arylsulfonate ions.

In the formula (IV), Ar ²¹ represents an aryl group having 20 or less carbon atoms which may have a substituent. Preferred substituents include a halogen atom, a nitro group, an alkyl group having 12 or less carbon atoms, an alkoxy group having 12 or less carbon atoms, an aryloxy group having 12 or less carbon atoms, and a 12 or less carbon atom. Alkylamino group, dialkylamino group having 12 or less carbon atoms, 1 carbon atom
An arylamino group having 2 or less or a diarylamino group having 12 or less carbon atoms is exemplified. Z ^{21 -} is Z ^11-
Represents a counter ion having the same meaning as

In the formula (V), R ³¹ , R ³² and R ³³ may be the same or different and represent a hydrocarbon group having 20 or less carbon atoms which may have a substituent. Preferred substituents include a halogen atom, a nitro group, an alkyl group having 12 or less carbon atoms, an alkoxy group having 12 or less carbon atoms, and an aryloxy group having 12 or less carbon atoms. Z ^31- represents a counter ion having the same ^meaning as Z ^11- .

In the present invention, specific examples of onium salts that can be suitably used as a radical generator include:
Paragraph number [003 of Japanese Patent Application No. 11-310623]
0] to [0033].

The radical generator used in the present invention preferably has a maximum absorption wavelength of 400 nm or less, more preferably 360 nm or less. By setting the absorption wavelength in the ultraviolet region, the image forming material can be handled under a white light.

These radical generators are used in an amount of 0.1 to 50% by weight, preferably 0.1 to 50% by weight, based on the total solid content of the coating solution for the photosensitive layer.
It can be added to the photosensitive layer coating solution at a ratio of 5 to 30% by weight, particularly preferably 1 to 20% by weight. If the amount is less than 0.1% by weight, the sensitivity is lowered, and if it exceeds 50% by weight, the non-image area is stained during printing. One of these radical generators may be used alone, or 2
More than one species may be used in combination. In addition, these radical generators may be added to the same layer as other components, or another layer may be provided and added thereto.

[(C) Radical polymerizable compound] The radical polymerizable compound used in the present invention is a radical polymerizable compound having at least one ethylenically unsaturated double bond, and has a terminal ethylenically unsaturated bond. At least one
, Preferably two or more compounds. Such compounds are widely known in the industrial field, and they can be used in the invention without any particular limitation. These have chemical forms such as, for example, monomers, prepolymers, ie, dimers, trimers and oligomers, or mixtures thereof and copolymers thereof. Examples of monomers and copolymers thereof include unsaturated carboxylic acids (eg, acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid, etc.) and esters and amides thereof, and are preferred. As the ester, an ester of an unsaturated carboxylic acid and an aliphatic polyhydric alcohol compound and an amide of an unsaturated carboxylic acid and an aliphatic polyamine compound are used. Further, an unsaturated carboxylic acid ester having a nucleophilic substituent such as a hydroxyl group, an amino group or a mercapto group, an addition reaction product of an amide with a monofunctional or polyfunctional isocyanate, an epoxy, a monofunctional or A dehydration-condensation reaction product with a functional carboxylic acid is also preferably used. Further, an addition reaction product of an unsaturated carboxylic acid ester or amide having an electrophilic substituent such as an isocyanate group or an epoxy group with a monofunctional or polyfunctional alcohol, amine or thiol, and further, halogen A substitution reaction product of an unsaturated carboxylic acid ester or amide having a leaving group such as a group or a tosyloxy group with a monofunctional or polyfunctional alcohol, amine or thiol is also suitable.
As another example, it is also possible to use a group of compounds in which the above unsaturated carboxylic acid is replaced with unsaturated phosphonic acid, styrene or the like.

Specific examples of acrylates, methacrylates, itaconic esters, crotonic esters, isocrotonic esters, and maleic esters which are radically polymerizable compounds which are esters of an aliphatic polyhydric alcohol compound and an unsaturated carboxylic acid For example, Japanese Patent Application No. 11-3
No. 10623, paragraphs [0037] to [004]
2], and these can be applied to the present invention.

Examples of other esters include aliphatic alcohol esters described in JP-B-46-27926, JP-B-51-47334, and JP-A-57-196231, and JP-A-59-5240 and JP-A-59-5240. 59-524
1, those having an aromatic skeleton described in JP-A-2-226149 and those containing an amino group described in JP-A-1-165613 are also preferably used.

Specific examples of the amide monomer of the aliphatic polyamine compound and the unsaturated carboxylic acid include methylene bis-acrylamide, methylene bis-methacrylamide, 1,6-hexamethylene bis-acrylamide, 1,6- Hexamethylene bis-methacrylamide,
Examples include diethylenetriaminetrisacrylamide, xylylenebisacrylamide, xylylenebismethacrylamide, and the like.

Examples of other preferable amide-based monomers include those having a cyclohexylene structure described in JP-B-54-21726.

Further, urethane-based addition-polymerizable compounds produced by an addition reaction between an isocyanate and a hydroxyl group are also suitable.
JP-A-8-41708 discloses a polyisocyanate compound having two or more isocyanate groups in one molecule to which a vinyl monomer having a hydroxyl group represented by the following formula (VI) is added. And vinyl urethane compounds containing at least two polymerizable vinyl groups.

Formula (VI) CH ₂ ＣC (R ⁴¹ ) COOCH ₂ CH (R ⁴² ) OH (where R ⁴¹ and R ⁴² represent H or CH ₃ )

Also, urethane acrylates described in JP-A-51-37193, JP-B-2-32293 and JP-B-2-16765, and
No. 49860, No. 56-17654, No. 62
Urethane compounds having an ethylene oxide skeleton described in JP-B-39417 and JP-B-62-39418 are also suitable.

Further, radical polymerizable compounds having an amino structure or a sulfide structure in the molecule described in JP-A-63-277563, JP-A-63-260909 and JP-A-1-105238 can be used. good.

Another example is disclosed in JP-A-48-641.
No. 83, JP-B-49-43191, JP-B-52-30
No. 490, polyfunctional acrylates and methacrylates such as polyester acrylates and epoxy acrylates obtained by reacting an epoxy resin with (meth) acrylic acid as described in each publication. Also,
JP-B-46-43946, JP-B-1-40337,
Specific unsaturated compounds described in JP-B-1-40336,
Vinyl phosphonic acid compounds described in JP-A-2-25493 can also be mentioned. In some cases, a structure containing a perfluoroalkyl group described in JP-A-61-22048 is preferably used. Furthermore, Japan Adhesion Association Journal vol. 20, No. 7, pages 300-308 (198
(4 years) as photocurable monomers and oligomers can also be used.

For these radical polymerizable compounds,
Details of the method of use, such as what kind of structure is used, whether it is used alone or in combination, and how much is added, can be arbitrarily set in accordance with the final performance design of the recording material. For example, it is selected from the following viewpoints. From the viewpoint of sensitivity, a structure having a large content of unsaturated groups per molecule is preferable, and in many cases, a bifunctional or more functional structure is preferable. In order to increase the strength of the image area, that is, the cured film, a compound having three or more functional groups is preferable, and a compound having a different functional number and a different polymerizable group (for example, an acrylate compound, a methacrylate ester) It is also effective to control both the photosensitivity and the intensity by using a combination of a compound and a styrene compound. Compounds with large molecular weight and compounds with high hydrophobicity are excellent in sensitivity and film strength,
It may not be preferable in terms of development speed and precipitation in a developer. In addition, the selection and use of the radical polymer compound is also an important factor for the compatibility and dispersibility with other components (for example, a binder polymer, an initiator, a colorant, and the like) in the photosensitive layer. Use of low purity compounds, 2
The compatibility may be improved by the combined use of at least one compound. In addition, a specific structure may be selected for the purpose of improving the adhesion of the support, the overcoat layer, and the like. Regarding the compounding ratio of the radical polymerizable compound in the image recording layer, a higher ratio is advantageous in sensitivity, but if the ratio is too large, undesired phase separation occurs or the production process due to the stickiness of the image recording layer. (For example, poor production resulting from transfer of recording layer components and adhesion) and problems such as precipitation from a developer. From these viewpoints, the preferable compounding ratio of the radical polymerizable compound is, in many cases, 5 to 80% by weight, preferably 20 to 80% by weight, based on all components of the composition.
75% by weight. These may be used alone or in combination of two or more. In addition, the method of using the radical polymerizable compound can be arbitrarily selected from the viewpoint of the degree of inhibition of polymerization with respect to oxygen, resolution, fogging, refractive index change, surface tackiness, etc. Depending on the case, a layer structure and a coating method such as undercoating and overcoating may be performed.

[(D) Binder polymer] In the present invention, a binder polymer is further used. It is preferable to use a linear organic polymer as the binder. Any of such “linear organic polymers” may be used. Preferably, a linear organic polymer which is soluble or swellable in water or weakly alkaline water is selected to enable development with water or weakly alkaline water. The linear organic polymer is selected and used not only as a film forming agent for forming a photosensitive layer but also as a developer for water, weakly alkaline water or an organic solvent.
For example, when a water-soluble organic polymer is used, water development becomes possible. Examples of such a linear organic polymer include a radical polymer having a carboxylic acid group in a side chain, for example,
Nos. 9-44615, JP-B-54-34327, JP-B-58-12577, JP-B-54-25957, JP-A-54-92723, JP-A-59-53836, and JP-A-59-71048. Those described, that is, methacrylic acid copolymer, acrylic acid copolymer, itaconic acid copolymer, crotonic acid copolymer, maleic acid copolymer, partially esterified maleic acid copolymer, and the like. Similarly, there is an acidic cellulose derivative having a carboxylic acid group in the side chain. In addition, a polymer obtained by adding a cyclic acid anhydride to a polymer having a hydroxyl group is useful.

Among these, a (meth) acrylic resin having a benzyl group or an allyl group and a carboxyl group in the side chain is particularly preferred because of its excellent balance of film strength, sensitivity and developability.

In addition, Japanese Patent Publication No. 7-12004,
JP-A-120041, JP-B-7-120042, JP-B-8-12424, JP-A-63-287944, JP-A-63-287947, JP-A-1-271174,
The urethane-based binder polymer containing an acid group described in Japanese Patent Application No. 10-116232 is very excellent in strength, and therefore is advantageous in terms of printing durability and low exposure suitability.

Further, as the water-soluble linear organic polymer, polyvinyl pyrrolidone, polyethylene oxide and the like are useful. In order to increase the strength of the cured film, alcohol-soluble nylon, polyether of 2,2-bis- (4-hydroxyphenyl) -propane and epichlorohydrin, and the like are also useful.

The weight average molecular weight of the polymer used in the present invention is preferably at least 5,000, more preferably in the range of 10,000 to 300,000, and the number average molecular weight is preferably at least 1,000, more preferably Ranges from 2000 to 250,000. The polydispersity (weight average molecular weight / number average molecular weight) is preferably 1 or more, and more preferably in the range of 1.1 to 10.

These polymers are random polymers,
Any of a block polymer and a graft polymer may be used, but a random polymer is preferable.

The polymer used in the present invention can be synthesized by a conventionally known method. As a solvent used in the synthesis, for example, tetrahydrofuran, ethylene dichloride, cyclohexanone, methyl ethyl ketone, acetone, methanol, ethanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, 2-methoxyethyl acetate, diethylene glycol dimethyl ether, 1-methoxy -2-propanol, 1-methoxy-2-propyl acetate, N, N-
Dimethylformamide, N, N-dimethylacetamide, toluene, ethyl acetate, methyl lactate, ethyl lactate,
Dimethyl sulfoxide, water and the like. These solvents are used alone or in combination of two or more. As the radical polymerization initiator used for synthesizing the polymer used in the present invention, known compounds such as an azo initiator and a peroxide initiator can be used.

The binder polymer used in the present invention may be used alone or as a mixture. These polymers are 20 to 95% by weight based on the total solid content of the photosensitive layer coating solution,
Preferably, it is added to the photosensitive layer at a ratio of 30 to 90% by weight. When the addition amount is less than 20% by weight, the strength of the image portion is insufficient when an image is formed. 95% by weight
If the number exceeds, no image is formed. The weight ratio of the radical polymerizable compound having an ethylenically unsaturated double bond and the linear organic polymer is preferably in the range of 1/9 to 7/3.

[Other Components of Photosensitive Layer] In the present invention, various compounds other than these may be further added, if necessary. For example, a dye having a large absorption in the visible light region can be used as a colorant for an image. In particular,
Oil Yellow # 101, Oil Yellow # 103, Oil Pink # 312, Oil Green BG, Oil Blue BOS, Oil Blue # 603, Oil Black B
Y, oil black BS, oil black T-505
(Orient Chemical Co., Ltd.), Victoria Pure Blue, Crystal Violet (CI4255)
5), methyl violet (CI42535), ethyl violet, rhodamine B (CI145170B),
Malachite green (CI42000), methylene blue (CI52015), etc., and JP-A-62-29324
No. 7 can be mentioned. Also, pigments such as phthalocyanine pigments, azo pigments, carbon black, and titanium oxide can be suitably used.

It is preferable to add these colorants since the image area and the non-image area can be easily distinguished after image formation. The addition amount is based on the total solid content of the photosensitive layer coating solution.
The ratio is 0.01 to 10% by weight.

In the present invention, a small amount of thermal polymerization inhibitor is used to prevent unnecessary thermal polymerization of a compound having a radically polymerizable ethylenically unsaturated double bond during preparation or storage of a photosensitive layer coating solution. It is desirable to add an agent. Hydroquinone, as a suitable thermal polymerization inhibitor,
p-methoxyphenol, di-t-butyl-p-cresol, pyrogallol, t-butylcatechol, benzoquinone, 4,4'-thiobis (3-methyl-6-t-butylphenol), 2,2'-methylenebis (4 -Methyl-6-t-butylphenol), N-nitroso-N-phenylhydroxylamine aluminum salt and the like. The addition amount of the thermal polymerization inhibitor is preferably about 0.01% to about 5% by weight based on the weight of the whole composition. If necessary, a higher fatty acid derivative such as behenic acid or behenic acid amide may be added to prevent polymerization inhibition by oxygen, and may be unevenly distributed on the surface of the photosensitive layer in a drying process after coating. . The amount of the higher fatty acid derivative to be added is about 0.1% of the total composition.
1% to about 10% by weight is preferred.

The photosensitive layer coating solution of the present invention may contain a nonionic solvent such as described in JP-A-62-251740 and JP-A-3-208514 in order to increase the stability of processing under development conditions. Surfactant, JP-A-59
An amphoteric surfactant as described in JP-A-121044 and JP-A-4-13149 can be added.

Specific examples of the nonionic surfactant include sorbitan tristearate, sorbitan monopalmitate, sorbitan triolate, stearic acid monoglyceride, polyoxyethylene nonyl phenyl ether and the like.

Specific examples of the amphoteric surfactant include alkyl di (aminoethyl) glycine, alkyl polyaminoethyl glycine hydrochloride, 2-alkyl-N-carboxyethyl-N-hydroxyethylimidazolinium betaine, N-tetradecyl-N , N-betaine type (for example,
(Trade name: Amogen K, manufactured by Dai-ichi Kogyo Co., Ltd.). The proportion of the nonionic surfactant and amphoteric surfactant in the photosensitive layer coating solution is preferably 0.05 to 15% by weight, more preferably 0.1 to 5% by weight.

Further, a plasticizer is added to the coating solution for the photosensitive layer according to the present invention, if necessary, for imparting flexibility to the coating film. For example, polyethylene glycol, tributyl citrate, diethyl phthalate, dibutyl phthalate, dihexyl phthalate, dioctyl phthalate, tricresyl phosphate, tributyl phosphate, trioctyl phosphate, tetrahydrofurfuryl oleate, and the like are used.

In order to produce the image-forming material according to the present invention, the above-mentioned components necessary for the coating solution for the photosensitive layer are usually dissolved in a solvent and coated on a suitable support. What is necessary is just to apply a coating liquid for a coat layer. Examples of the solvent used for the photosensitive layer coating solution include ethylene dichloride, cyclohexanone, methyl ethyl ketone, methanol, ethanol, propanol, ethylene glycol monomethyl ether, 1-methoxy-2-propanol, 2-methoxyethyl acetate, and 1-methoxy-2.
-Propyl acetate, dimethoxyethane, methyl lactate, ethyl lactate, N, N-dimethylacetamide,
N-dimethylformamide, tetramethylurea, N-
Examples include, but are not limited to, methylpyrrolidone, dimethylsulfoxide, sulfolane, γ-butyllactone, toluene, water, and the like. These solvents are used alone or as a mixture. The concentration of the above components (total solids including additives) in the solvent is preferably 1 to 5
0% by weight.

The coating amount (solid content) of the photosensitive layer obtained after coating and drying varies depending on the application, but generally 0.5 to 5.0 g / m ² is preferable for the image forming material. Various methods can be used as the method of coating, and examples thereof include bar coater coating, spin coating, spray coating, curtain coating, dip coating, air knife coating, blade coating, and roll coating. As the coating amount decreases, the apparent sensitivity increases, but the film characteristics of the photosensitive layer that performs the function of image recording deteriorate.

The photosensitive layer coating solution according to the present invention may contain a surfactant for improving coating properties, for example, JP-A-62-17.
No. 0950 can be added. The preferable addition amount is 0.01 to 1% by weight, more preferably 0.05 to 0.5% by weight, based on the solid content of the material of the entire photosensitive layer.

In the negative type image recording material of the present invention,
The energy of the irradiated infrared laser or the like is converted into heat by the infrared absorbent (A), and the radical generator (B) generates radicals by the heat. By the action of the radical, the radical polymerizable compound (C) and the binder polymer (D) accelerate the polymerization and curing reaction, thereby performing image recording, that is, plate making of the recording material.
However, in the air, water, bases, acids, which trap radicals generated during exposure in the photosensitive layer and inhibit the polymerization reaction,
Compounds such as oxygen are floating. Since these suspended matters inhibit the above-mentioned polymerization reaction due to heat, it is preferable to provide an overcoat layer in the negative image forming material to which the method of the present invention is applied.

[Overcoat layer] The overcoat layer according to the present invention is particularly transparent as long as it is transparent to actinic rays, that is, rays used for image exposure, and has a certain degree of adhesiveness to an adjacent photosensitive layer. There is no limitation, and known ones can be selected and used. Such an overcoat layer is provided in order to inhibit the compound in the photosensitive layer and the compound generated by exposure to actinic light from being affected by the outside air. Therefore, it is preferable that the low molecular compound existing in the air and the low molecular compound generated in the photosensitive layer have low permeability. That is, the overcoat layer is formed of a substance that traps a compound generated during exposure in the photosensitive layer, or a compound such as water, a base, an acid or oxygen that exists in the air that inhibits a reaction that occurs in the photosensitive layer. Any material can be used as long as it can be prevented from being mixed into the photosensitive layer and the overcoat layer in the non-image area can be removed before or during development. That is, a film having low gas permeability or a film is preferable.

Specific examples of the compound forming the overcoat layer include polyvinyl alcohol, polyvinylidene chloride, poly (meth) acrylonitrile, polysulfone, acetylcellulose, polyvinyl chloride, polyvinyl acetate, and ethylene-vinyl alcohol copolymer. Coalescence, polyethylene, polycarbonate, polystyrene, polyethylene, polyamide, cellophane, acrylic resin, gelatin,
Gum arabic and the like. These can be used alone or
You may use together. More preferably, water-soluble polymers such as polyvinyl alcohol, water-soluble acrylic resin, polyvinylpyrrolidone, gelatin, and gum arabic can be mentioned from the viewpoint of ease of removal during development and ease of coating.
Still more preferably, polyvinyl alcohol, which can be coated with water as a solvent and can be removed with an aqueous developer,
Polyvinylpyrrolidone, gelatin, and gum arabic are preferred, and in order to improve their removability, these water-soluble polymers include a nitrogen-containing water-soluble polymer having a partial structure such as an amine, and a water-soluble polymer having an acid group such as sulfonic acid. You may use together.

The polyvinyl alcohol used in the overcoat layer of the present invention can be partially substituted with an ester, ether or acetal as long as it contains a substantial amount of unsubstituted vinyl alcohol units having the required water solubility. May be. In addition, similarly, a part thereof may contain another copolymerization component. As specific examples of polyvinyl alcohol,
71-100% hydrolyzed, polymerization degree 300-240
And those in the range of 0. Specifically, Kuraray Co., Ltd. (trade name) PVA-105, PvA-11
0, PVA-117, PVA-117H, PVA-12
0, PVA-124, PVA-124H, PVA-C
S, PVA-CST, PVA-HC, PVA-203,
PVA-204, PVA-205, PVA-210, P
VA-217, PVA-220, PVA-224, PV
A-217EE, PVA-220, PVA-224, P
VA-217EE, PVA-217E, PVA-220
E, PVA-224, PVA-405, PVA-42
0, PVA-613, L-8 and the like. The above-mentioned copolymers include polyvinyl acetate chloroacetate or propionate, polybierformal and polybieracetal hydrolyzed 88 to 100%, and copolymers thereof. Other useful polymers include polyvinylpyrrolidone, gelatin and gum arabic, which may be used alone or in combination.

As a solvent used for applying the overcoat layer, pure water is preferable, but alcohols such as methanol and ethanol, and ketones such as acetone and methyl ethyl ketone may be mixed with the pure water. The concentration of the solid content in the coating solution is suitably from 1 to 20% by weight.

The overcoat layer may further contain known additives such as a surfactant for improving coating properties and a water-soluble plasticizer for improving physical properties of the film. Examples of the water-soluble plasticizer include propionamide, cyclohexanediol, glycerin, and sorbitol. Further, a water-soluble (meth) acrylic polymer or the like may be added.

The amount of the coating is about 0.1 / m 2 after drying.
A range from ² to about 15 / m ² is suitable. More preferably, it is 1.0 / m ² to about 5.0 / m ² .

In the method of the present invention, this image forming material is
Image recording is performed with an infrared laser. Also, thermal recording with an ultraviolet lamp or a thermal head is possible. In the present invention, it is preferable that the image is exposed by a solid-state laser or a semiconductor laser that emits infrared rays having a wavelength of 760 nm to 1200 nm. The output of the laser is preferably 100 mW or more, and in order to shorten the exposure time, it is preferable to use a multi-beam laser device. Further, the exposure time per pixel is preferably within 20 μsec.
The energy applied to the recording material is 10 to 300 mJ /
cm ² is preferred.

The image forming material is exposed by an infrared laser and then developed with a developing solution to obtain a lithographic printing plate.

As a base of the developing solution and the replenishing solution used in the image forming method of the present invention, a conventionally known aqueous alkali solution can be used. It is preferable to use a weak alkaline aqueous solution in the range of 12, and more preferably a weak alkaline aqueous solution having a pH of about 8 to 10. The conventional general-purpose developer has a pH of 12.5 to 13.5, but according to the method of the present invention, only the curing of the image area is promoted without affecting the unexposed area. Even if a weak alkaline aqueous solution is used, there is no concern that a residual film is generated, and there is also an advantage that good development can be performed without impairing the printing durability of the image area.

As a developing solution, a so-called “silicate developing solution” using an alkali silicate and containing silicon dioxide,
A non-reducing sugar and a base, or a surfactant and a base,
There are "non-silicate developers" that are substantially free of silicon dioxide. Here, “substantially” means that the presence of trace amounts of silicon dioxide as unavoidable impurities and by-products is allowed. In the developing step of the image forming material of the present invention, any of the above-mentioned developing solutions can be applied, but from the viewpoint of the effect of suppressing the generation of scratches, it is preferable to use a non-silicate developing solution.

First, the "silicate developer" will be described. The alkali silicate exhibits alkalinity when dissolved in water, and examples thereof include alkali metal silicates such as sodium silicate, potassium silicate, and lithium silicate, and ammonium silicate. The alkali silicate may be used alone or in combination of two or more. The aqueous alkali solution contains silicon oxide SiO _{2 as} a component of silicate and alkali oxide M ₂ O (M
Represents an alkali metal or ammonium group. ) Can be easily adjusted by adjusting the mixing ratio and the concentration, for example, an alkali metal described in JP-A-54-62004 and JP-B-57-7427. Silicates are used effectively. Among the alkali aqueous solutions, those having a mixing ratio (SiO ₂ / M ₂ O: molar ratio) of the silicon oxide SiO ₂ and the alkali oxide M ₂ O of 0.5 to 3.0 are preferable, and 1.0 to 3.0. 2.
0 is more preferred. When the SiO ₂ / M ₂ O is 0.
If it is less than 5, the alkali strength increases,
When a general-purpose aluminum plate or the like is etched as a support for a lithographic printing original plate, a bad effect may occur, and when it exceeds 3.0, developability may be reduced.

The concentration of the alkali silicate in the developer is 1 to 10% by weight based on the weight of the aqueous alkali solution.
Is preferably 3 to 8% by weight, and most preferably 4 to 7% by weight. If the concentration is less than 1% by weight, the developability and the processing capacity may be reduced. If the concentration is more than 10% by weight, precipitates and crystals are easily formed. And it may interfere with waste liquid treatment.

Next, the “non-silicate developer” will be described. Non-silicate developers suitable for the method of the present invention include:
As described above, a non-reducing sugar is composed of a non-reducing sugar and a base.Here, the non-reducing sugar means a saccharide having no reducing property because it has no free aldehyde group or ketone group, Trehalose-type oligosaccharides in which reducing groups are bonded to each other, glycosides in which a reducing group of a saccharide is bonded to a non-saccharide, and sugar alcohols obtained by hydrogenating and reducing saccharides are classified. In the present invention, any of these can be suitably used.

The trehalose-type oligosaccharides include, for example, saccharose and trehalose, and the glycosides include, for example, alkyl glycosides, phenol glycosides, and mustard oil glycosides. Examples of the sugar alcohol include D, L-arabit, ribit, xylit, D, L-sorbit, D, L-annit,
D, L-idit, D, L-talit, zuricit, allozurcit and the like. Further, maltitol obtained by hydrogenation of a disaccharide, a reductant (reduced starch syrup) obtained by hydrogenation of an oligosaccharide, and the like can also be preferably mentioned.

Among the non-reducing sugars, sugar alcohols and saccharose are preferred, and D-sorbitol, saccharose, and reduced starch syrup are more preferred because they have a buffering action in an appropriate pH range. These non-reducing sugars may be used alone or in combination of two or more, and the ratio in the developer is preferably 0.1 to 30% by weight,
1-20% by weight is more preferred.

Among the non-reducing sugars, sugar alcohols and saccharose are preferred, and D-sorbitol, saccharose, and reduced starch syrup are more preferred because they have a buffering action in an appropriate pH range. These non-reducing sugars may be used alone or in combination of two or more, and the ratio in the developer is preferably 0.1 to 30% by weight,
1-20% by weight is more preferred.

The alkali silicate or the non-reducing sugar can be combined with an alkali agent as a base by appropriately selecting it from conventionally known ones. Examples of the alkaline agent include sodium hydroxide, potassium hydroxide,
Lithium hydroxide, trisodium phosphate, tripotassium phosphate, triammonium phosphate, disodium phosphate, dipotassium phosphate, diammonium phosphate, sodium carbonate, potassium carbonate, ammonium carbonate, sodium bicarbonate, potassium bicarbonate And inorganic alkali agents such as ammonium bicarbonate, sodium borate, potassium borate and ammonium borate, potassium citrate, tripotassium citrate and sodium citrate. In addition, monomethylamine, dimethylamine, trimethylamine,
Monoethylamine, diethylamine, triethylamine, monoisopropylamine, diisopropylamine,
Organic alkali agents such as triisopropylamine, n-butylamine, monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanol amici, ethyleneimine, ethylenediamine, and pyridine can also be suitably mentioned. These alkaline agents may be used alone or in combination of two or more.

Of these, sodium hydroxide and potassium hydroxide are preferred. The reason is that adjusting the amount of addition to the non-reducing sugar enables pH adjustment in a wide pH range. Also, trisodium phosphate,
Tripotassium phosphate, sodium carbonate, potassium carbonate, and the like are also preferable because they themselves have a buffering action.

The non-silicate developer which can be suitably used in the present invention further includes a weakly alkaline aqueous solution of a surfactant and a base having a pH of 7 to 12. Preferred surfactants that can be used in this developer include polyoxyethylene alkyl ethers,
Polyoxyethylene alkyl phenyl ethers, polyoxyethylene polystyryl phenyl ethers, polyoxyethylene polyoxypropylene alkyl ethers, glycerin fatty acid partial esters, sorbitan fatty acid partial esters, pentaerythritol fatty acid partial esters, propylene glycol monofatty acid Esters, sucrose fatty acid partial esters, polyoxyethylene sorbitan fatty acid partial esters, polyoxyethylene sorbitol fatty acid partial esters, polyethylene glycol fatty acid esters, polyglycerin fatty acid partial esters, polyoxyethylenated castor oil, polyoxyethylene Glycerin fatty acid partial esters, fatty acid diethanolamides, N, N-bis-2-hydroxyalkylamines, Polyoxyethylene alkyl amines,
Nonionic surfactants such as triethanolamine fatty acid esters and trialkylamine oxides, fatty acid salts, abietic acid salts, hydroxyalkanesulfonic acid salts, alkanesulfonic acid salts, dialkylsulfosuccinic acid ester salts, linear alkylbenzenesulfonic acid salts , Branched-chain alkylbenzenesulfonates, alkylnaphthalenesulfonates, alkylphenoxypolyoxyethylenepropylsulfonates, polyoxyethylenealkylsulfophenylether salts, N-methyl-N-oleyltaurine sodium salt, N-alkylsulfosuccinic acid Monoamide disodium salts, petroleum sulfonates, sulfated castor oil, sulfated tallow oil, sulfates of fatty acid alkyl esters, alkyl sulfates, polyoxy Tylene alkyl ether sulfates, fatty acid monoglyceride sulfates, polyoxyethylene alkyl phenyl ether sulfates, polyoxyethylene styryl phenyl ether sulfates, alkyl phosphates, polyoxyethylene alkyl ethers phosphates, Anions such as polyoxyethylene alkyl phenyl ether phosphates, partially saponified styrene-maleic anhydride copolymers, partially saponified olefin-maleic anhydride copolymers, and naphthalene sulfonate formalin condensates Surfactants,

Cationic surfactants such as alkylamine salts, quaternary ammonium salts, polyoxyethylene alkylamine salts, and polyethylenepolyamine derivatives;
Examples include amphoteric surfactants such as carboxybetaines, aminocarboxylic acids, sulfobetaines, aminosulfates, and imidazolines. Among the surfactants mentioned above, those with polyoxyethylene can be read as polyoxyalkylenes such as polyoxymethylene, polyoxypropylene, and polyoxybutylene, and these surfactants are also included. You.

Preferred bases include carbonates, bicarbonates, and amines. Suitable carbonates and bicarbonates include alkali metal carbonates and bicarbonates, alkaline earth metal carbonates and bicarbonates, ammonium carbonates and bicarbonates, and the like. Particularly preferred are sodium carbonate, sodium hydrogen carbonate, potassium carbonate, potassium hydrogen carbonate and the like. These carbonates and bicarbonates may be anhydrous or hydrated. Further, two or more kinds of carbonates and bicarbonates can be used as a mixture. Preferred amines include the amines described above.

The developer used in the method of the present invention may contain, if necessary, known additives in a range not to impair the effects of the present invention. Examples of such additives include surfactants, reducing agents such as sodium salts and potassium salts of inorganic acids such as hydroquinone, resorcinol, sulfurous acid and bisulfite, organic carboxylic acids, organic solvents such as benzyl alcohol, and defoaming agents. And water softeners.

When developing using an automatic developing machine, an aqueous solution (replenisher) having a higher alkali strength than the developing solution is added to the developing solution, so that the developing solution in the developing tank can be replaced for a long time without replacement. It is known that large quantities of lithographic printing plates can be processed. In the present invention, this replenishment method is preferably applied.
It is preferably in the range of 12.

The image-forming material which has been developed using the above-described developing solution and replenishing solution may be, if desired, a washing water, a rinsing solution containing a surfactant or the like, or a desensitizing solution containing gum arabic or a starch derivative. After post-processing, it is used as a lithographic printing plate.

In recent years, in the plate making / printing industry, automatic developing machines for printing plate materials have been widely used in order to rationalize and standardize plate making operations. This automatic developing machine generally includes a developing section and a post-processing section, and includes a device for transporting a printing plate material, each processing solution tank, and a spray device. The developing process is performed by spraying each pumped processing liquid from a spray nozzle. Recently, a method is also known in which a printing plate material is immersed and conveyed by a submerged guide roll or the like into a processing liquid tank filled with a processing liquid to perform processing. In such automatic processing,
Processing can be performed while replenishing each processing solution with a replenisher according to the processing amount, operating time, and the like. In addition, the electric conductivity can be detected by a sensor and replenished automatically. Further, a so-called disposable processing method in which processing is performed with a substantially unused processing liquid can also be applied.

The lithographic printing plate obtained as described above can be subjected to a printing step after applying a desensitized gum if desired. Is subjected to a burning process.

In the case of burning a lithographic printing plate, prior to burning, Japanese Patent Publication Nos. 61-2518 and 55-280.
No. 62, JP-A-62-131859 and JP-A-61-1596.
It is preferable to treat with a surface-regulating liquid as described in each of the publications No. 55.

[0134] As a method for this, a sponge or absorbent cotton impregnated with the surface conditioning liquid is applied onto a lithographic printing plate,
A method in which a printing plate is immersed in a vat filled with a surface conditioning liquid to apply the printing plate, an application using an automatic coater, or the like is applied. Further, it is preferable to make the application amount uniform with a squeegee or a squeegee roller after the application. The application amount of the surface conditioning liquid is generally 0.03 to 0.8 g / m ^2.
(Dry weight) is appropriate.

The lithographic printing plate to which the surface conditioning liquid has been applied is dried, if necessary, and then burned by a burning processor (for example,
It is heated to a high temperature by a burning processor (BP-1300) sold by Fuji Photo Film Co., Ltd. The heating temperature and time in this case depend on the type of the component forming the image, but may be 1 to 180 ° C. to 300 ° C.
A range of up to 20 minutes is preferred.

The burn-processed lithographic printing plate can be subjected to a conventional treatment such as washing with water or gumming, if necessary. However, a surface conditioning solution containing a water-soluble polymer compound or the like can be used. When is used, so-called desensitizing treatment such as gumming can be omitted.

A lithographic printing plate obtained by exposing and developing the image forming material of the present invention is applied to an offset printing machine or the like, and used for printing a large number of sheets.

[0138]

The present invention will be described in detail with reference to the following examples, but the present invention is not limited to these examples. (Example 1) [Preparation of support] An aluminum plate of material 1S having a thickness of 0.30 mm was grained with a No. 8 nylon brush and an aqueous suspension of 800 mesh pumistone, and the surface thereof was grained. And washed. 6% in 10% sodium hydroxide at 70 ° C
After immersion for 0 seconds and etching, washing with running water,
The resultant was neutralized and washed with% HNO ₃ and water. VA = 12.7
Under a condition of V, an electrolytic surface roughening treatment was performed in a 1% nitric acid aqueous solution using an alternating current of a sine wave at an anode electricity of 300 coulomb / dm ² . The surface roughness was measured.
It was 45 μ (Ra indication). 30% H
_After immersion in a ₂ SO ₄ aqueous solution and desmutting at 55 ° C. for 2 minutes, a cathode was placed on the grained surface in a 20% H ₂ SO ₄ aqueous solution at 33 ° C., and a cathode was placed at a current density of 5 A / dm ² . After anodizing for 2 seconds, the thickness was 2.7 g / m ² . No. 3 sodium silicate (SiO ₂ = 28-30)
%, Na ₂ O = 9-10%, Fe = 0.02% or less), 2.5% by weight, pH = 11.2, 70 ° C. for various times, followed by washing with water and drying, A silicate-treated substrate was obtained.

[Formation of Intermediate Layer] Next, S
A liquid composition (sol solution) of Method G was prepared. The following composition was weighed into a beaker and stirred at 25 ° C. for 20 minutes. Si (OC ₂ H ₅ ) ₄ 38 g 3-methacryloxypropyltrimethoxysilane 13 g 85% phosphoric acid aqueous solution 12 g ion-exchanged water 15 g methanol 100 g

The above solution was transferred to a three-necked flask, fitted with a reflux condenser, and the three-necked flask was immersed in an oil bath at room temperature. The contents of the three-necked flask were heated to 50 ° C. in 30 minutes while stirring with a magnetic stirrer. While maintaining the bath temperature at 50 ° C, the reaction was further performed for 1 hour to obtain a liquid composition (sol liquid). This sol solution was diluted with methanol / ethylene glycol = 20/1 (weight ratio) so as to be 0.5% by weight, applied with a wheeler to the silicate-treated substrate, and dried at 100 ° C. for 1 minute. The coating amount at that time is 4
mg / m ² . The amount of the Si element was also determined by the fluorescent X-ray analysis method, and this amount was used as the amount of the Si coating.

[Photosensitive layer] Next, the following photosensitive layer coating solution [P]
The intermediate layer was formed, and the coated intermediate layer was coated on a pre-coated aluminum plate using a wire bar, and dried at 115 ° C. for 45 seconds in a hot-air drying apparatus to form a photosensitive layer. An original plate [P-1] was obtained, and this was designated as Example 1. The coating amount after drying was in the range of 1.2 to 1.3 g / m ^2.

<Coating solution for photosensitive layer [P]> • Infrared absorber [IR-6] 0.08 g • Onium salt [OI-6] 0.30 g • Dipentaerythritol hexaacrylate 1.00 g • Allyl methacrylate and methacrylic acid Copolymer having a molar ratio of 80:20 (weight average molecular weight 120,000) 1.00 g ・ Victoria pure blue naphthalene sulfonate 0.04 g ・ Fluorine surfactant 0.01 g・ Methyl ethyl ketone 9.0g ・ Methanol 10.0g ・ 1-Methoxy-2-propanol 8.0g

[0143]

Embedded image

Comparative Example 1 A negative-type lithographic printing plate was prepared by forming a photosensitive layer directly on a silicate-treated support in the same manner as in Example 1 except that the intermediate layer was not provided. An original plate [P-2] was obtained and used as Comparative Example 1.

[Exposure] The obtained negative type lithographic printing plate precursors [P-1] and [P-2] were prepared by using a Trendset with Creo Corporation equipped with a water-cooled 40 W infrared semiconductor laser.
With r3244VFS, the plate surface energy is 20 to 200
Exposure was performed while changing the conditions in the range of mJ / cm ² .

[Development processing] After exposure, development processing was carried out using an automatic developing machine Stublon 900N manufactured by Fuji Photo Film Co., Ltd. As a developing solution, a developing solution [1] (pH at 9.9 at 25 ° C.) having the following formulation was used for both the charging solution and the replenishing solution. The temperature of the developing bath was 30 ° C. Also, the finisher
A 1: 1 aqueous dilution of FN-6 manufactured by Fuji Photo Film Co., Ltd. was used. The pH of the developing solution shown below was 25
The result measured at ° C is shown.

<Developing solution [1]>-Sodium carbonate monohydrate 10 g-Potassium hydrogen carbonate 10 g-Sodium isopropylnaphthalenesulfonate 15 g-Sodium dibutylnaphthalenesulfonate 15 g-Sodium salt of ethylene glycol mononaphthyl ether monosulfate 10g ・ Sodium sulfite 1g ・ Ethylenediaminetetraacetic acid tetrasodium 0.1g ・ Ion exchange water 938.9g

[Evaluation of Sensitivity] Under the above exposure conditions, the minimum plate surface energy at which an image was formed was defined as the sensitivity. In the negative type lithographic printing plate [P-1] of Example 1, an image was formed at a plate surface energy of 50 mJ / cm ² , but in the lithographic printing plate [P-2] of Comparative Example 1, 80 mJ / cm was required to form an image.
Needed ^two . As a result, it was confirmed that the sensitivity of Example 1 was higher than that of Comparative Example 1. This is probably because the intermediate layer having a function as a heat insulating layer was formed in Example 1, and the heat generated by the exposure was efficiently used for the curing reaction of the photosensitive layer.

[Evaluation of Printing Durability, Chemical Resistance, and Dirt]
The plate printing plates [P-1] and [P-2] were converted to plate energy 1
00mJ / cm ^TwoExposure under the conditions of
Created a printing plate. Using the obtained printing plate, Komori Ko
Printing using Lislon printing machine manufactured by
Was. As ink, Geos G (N) manufactured by Dainippon Ink and Chemicals, Inc.
It was used. Acidic PS as a plate cleaner
Using a multi-cleaner (Fuji Photo Film Co., Ltd.)
Was. Multi-cleaner on 5000th sheet from the start of printing
Into the printing sponge, wipe the halftone dots
The ink was washed. 50,000th sheet after every 5,000 sheets
Wash the ink on the printing plate with the multi-cleaner
Was. Remove the printed matter every 5,000 sheets and use a multi-cleaner
The halftone dots that washed the plate surface and the halftone dots that were not washed were evaluated.
In addition, the printed matter is visually observed, and stains on the image area and the non-image area are observed.
Was evaluated.

As a result, in Example 1, 50,000 good prints were obtained, but in Comparative Example 1, only 20,000 prints were obtained. Further, no stain was observed on the non-image portion of the obtained printed matter. Comparative Example 1 in which no intermediate layer was formed
It was found that, when washed with a multi-plate cleaner, the dots of highlights were flying quickly, but in Example 1, the jump of dots was not observed. As a result, the formation of the intermediate layer improves the adhesion of the photosensitive layer, thereby improving the chemical resistance to acidic plate cleaners, preventing dot and thin lines from jumping and blurring, and improving printing durability. I found out.

[0151]

According to the present invention, recording is performed using a solid-state laser and a semiconductor laser that emit infrared light.
An image forming material suitable for a lithographic printing plate which can be directly recorded from digital data of a computer or the like and has excellent image forming properties and printing durability can be provided.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H025 AA04 AA12 AB03 AC08 AD01 BC13 BC31 CB00 CC11 DA18 DA35 DA36 DA40 FA10 2H096 AA06 BA05 CA05 EA04 EA23

Claims (1)

[Claims] 1. An aluminum support, a silicate film, an intermediate layer containing a silicone compound having a functional group capable of causing an addition reaction by radicals, (A) an infrared absorber, (B) a radical generator, and (C) A) a negative-type image forming material in which a photosensitive layer containing a radically polymerizable compound and a binder polymer (D) is sequentially provided.