JPH0327043A - Photosensitive planographic printing plate requiring no dampening water - Google Patents

Abstract

PURPOSE:To improve the adhesion of a primer layer to an Al supporting body by treating the body with an aq. soln. of an alkali metal silicate and/or coating the body with colloidal silica sol and combining a prescribed silane coupling agent with the primer layer. CONSTITUTION:The subject planographic printing plate is formed by successively laminating a primer layer, a photosensitive layer and a silicone rubber layer on the supporting body. An Al sheet treated with an aq. soln. of an alkali metal silicate such as sodium silicate and/or coated with colloidal silica sol is used for the supporting body and the primer layer contains at least one kind of silane coupling agent such as gamma-glycidoxypropyltrimethoxysilane. This printing plate withstands violent rubbing because the primer layer has improved adhesion to the supporting body.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a photosensitive lithographic printing plate that does not require dampening water, and in particular, to a method for improving the adhesion between an aluminum support and a single layer of brimer provided thereon in a wet state during development processing. This invention relates to a photosensitive lithographic printing plate that does not require dampening water and has improved properties.

[Conventional technology]

For photosensitive lithographic printing plates that do not require dampening water and have a silicone rubber layer as a non-image area, for example, Japanese Patent Publication No. 44-23042
No., Special Publication No. 6-1 604 4, Special Publication No. 1982
-26923, JP 61-54222, JP 6
Various methods have already been proposed in No. 3-2, 6, 5, 2, 4, and the like.

Aluminum plates are widely used as supports for these photosensitive lithographic printing plates that do not require dampening water.

The reason is as follows. That is, the support of photosensitive lithographic printing plates that use dampening water, which currently makes up the majority of lithographic printing plates, is an aluminum plate.
Most of the lithographic printing presses currently in operation on the market have a structure suitable for mounting an aluminum plate. Therefore, by using aluminum as a support even in a lithographic printing plate that does not require dampening water, it becomes possible to use the plate mounting device of a printing press without special modification. In addition, workers who handle plates at the plate-making site of lithographic printing plates are familiar with handling printing plates made of aluminum supports, so the strength of aluminum,
For example, maintaining the advantages of an aluminum support, such as resistance to formation of nicks, resistance to deformation due to pressure, etc., dimensional stability before and after development processing, and relatively light weight for a metal support. I strongly desire. The above circumstances are the reasons why aluminum is used as a support even in lithographic printing plates that do not require dampening water.

On the other hand, the main reason for using an aluminum support in conventional photosensitive lithographic printing plates that use dampening water is that its surface is hydrophilic, and it can relatively easily exhibit high water retention through surface treatment.

However, in the photosensitive lithographic printing plate that does not require dampening water according to the present invention, no dampening water is used and the ink repellency of the silicone rubber layer is utilized in the non-image area, so the hydrophilicity of the aluminum surface is not utilized. Therefore, conventionally, when an aluminum plate support is used in a photosensitive lithographic printing plate that does not require dampening water, no special treatment is usually performed other than degreasing the rolling oil mixed in during rolling.

As a method of improving the adhesion between the coating layer placed on the surface of such an aluminum plate and the aluminum support, it has been proposed to include compounds that have various adhesion-improving effects in the coating layer. . For example, JP-A-63-305360 discloses that adhesion can be improved by incorporating a silane coupling agent into a primer layer made of hardened gelatin provided adjacent to a support. .

However, when an aluminum plate having a hydrophilic surface was used as a support, it was not always possible to obtain sufficient adhesion. In particular, JP-A-61-275759
After treatment with a water-based developer as described in the Japanese Patent Publication No. 63-331-40 or a pre-treatment solution for swelling the silicone layer, water or When developing the plate while rubbing it with a brush in a processing solution mainly containing water, depending on conditions such as the temperature of the developer and the rubbing pressure of the brush, the periphery of the plate may
The problem arises that the coating layer peels off from the aluminum surface.

[Problem to be solved by the invention]

Therefore, an object of the present invention is to provide a photosensitive lithographic printing plate that does not require dampening water and has improved adhesion between an aluminum support and a single layer of brimer provided thereon.

[Means to solve the problem]

As a result of various studies, the present inventors found that a primer layer provided adjacent to a support made of an aluminum plate treated with an aqueous alkali metal silicate solution and/or coated with colloidal silica sol. It has been found that the adhesion is dramatically improved by containing at least one type of silane coupling agent, and the above object is achieved, and the present invention has been completed.

That is, the present invention provides a photosensitive lithographic printing plate that does not require dampening water, in which a primer layer, a photosensitive layer, and a silicone rubber layer are provided in this order on a support, wherein the support is treated with an aqueous alkali metal silicate solution and/or Alternatively, it is an aluminum plate coated with colloidal silica sol, and the primer layer contains at least one type of silane coupling agent.

The present invention will be explained in detail below.

Aluminum Support> The aluminum plate used in the present invention is a plate-shaped body made of pure aluminum or an aluminum alloy containing a trace amount of foreign atoms, which mainly contains aluminum. These foreign atoms include silicon, iron, manganese, copper, magnesium, chromium,
These include zinc, bismuth, nickel, and titanium. The alloy composition has a content of at most 10% by weight or less.

Aluminum suitable for the present invention is pure aluminum, but since it is difficult to produce completely pure aluminum due to scouring technology, it is preferable to use aluminum that contains as few foreign atoms as possible.

Further, an anoleminium alloy having the above-mentioned content can be used as a vine material in the present invention. As described above, the aluminum plate applied to the present invention is not limited in its composition, and any conventionally known or publicly used material can be used as appropriate. The thickness of the aluminum plate used in the present invention is approximately 0.1 mm to 0.1 mm. 5
It is about mm.

Such an aluminum plate is treated with, for example, a surfactant or an alkaline aqueous solution in order to remove rolling oil from the surface.

The aluminum plate thus degreased may be anodized if desired.

The conditions for anodic oxidation vary depending on the electrolyte used, so they cannot be definitively specified, but generally speaking, the electrolyte concentration is 1 to 80% by weight solution, the liquid temperature is 5 to 70°C, and the current density is 0.
A range of 5 to 60 A/dm'', a voltage of 1 to 10 volts, and an electrolysis time of 10 seconds to 50 minutes is suitable.

The amount of the anodic oxide film is preferably in the range of 0.01 to 10 g/m', more preferably in the range of 0.1 to 4 g/m'.

After the above-mentioned treatment, washing with water, treatment with aqueous alkali metal silicate solution, or application of colloidal silica sol are performed.

After the treatment with aqueous alkali metal silicate solution, colloidal silica sol may be applied.

Alkali metal silicate aqueous solution treatment> Alkali metal silicate aqueous solution treatment is described in U.S. Patent Nos. 2 and 7.
14. Specification No. 066 and No. 3, 181, 46
As described in Specification No. 1, it is treated with an aqueous solution of sodium silicate, potassium silicate, lithium silicate, etc. As a treatment method, 0.5 to 30% by weight, preferably 1 to 1
In an aqueous solution with a concentration of 5% by weight, at a temperature of 15°C to 90°C, 0.
It may be sprayed or immersed for 5 to 120 seconds and washed with water.

Application of colloidal silica sol> The colloidal silica sol used in the present invention is a colloidal silica liquid obtained by dissolving ultrafine particles of high molecular weight silicic anhydride in a solvent. Those that use water as a solvent are called aqueous silica sol, and those that use a polar organic solvent are called organosols. Silica sol is made from water glass and silicate ester, but for details on the manufacturing method and properties, please refer to "Ceramic Coating".
(Published by Nikkan Kogyo Shimbun in September 1988) Chapter 3,
Inorganic Coating" (July 1980, published by Kindai Shuppansha), Chapter 1. Among these colloidal silica sols, aqueous silica sol and methanol-dispersed silica sol are preferred from the viewpoint of manufacturing method.

Colloidal silica sol generally contains 10 to 50% by weight of 3102 and 0.01 to 2.00% by weight of Na20, and has a particle size of 5 to 30 mμ.

Any method can be used to apply the colloidal silica sol, such as a method using a wheeler coater, a roll coater coater, a bar coater coater, etc., or a dipping treatment method.

The coating liquid or treatment liquid can be used by diluting a commercially available colloidal silica sol, and whether the diluting liquid is an aqueous silica sol or an organosol, for example, a mixed solvent of pure water and methanol may be used.

If there is no problem with the stability of the colloidal silica sol, the higher the methanol ratio, the smaller the drying load and the lower the surface tension of the coating solution, allowing for even and uniform coating. The content of Si02 in the coating liquid is 0. 2 to 4.0% by weight of O O is suitable. The coating amount of the colloidal silica sol coating layer is 0. 5 mg/m'~1. Og/m'
It is preferable to set it within the range of .

Particularly preferred is a range of 1 to 500 mg/m'.

0. If the amount is less than 5 mg/m', the adhesion strength will not improve, and 1. If it is more than 0 g, the flexibility of the film will be impaired,
The film tends to crack when handling the plate.

The layer to be formed on the aluminum support obtained in this way depends on the required performance of the photosensitive lithographic printing plate, such as whether it is positive or negative type, and whether the photosensitive layer is removed or not removed during development processing. Although various configurations can be selected, in order to achieve the excellent adhesion to the support of the present invention, it is necessary to include at least one type of primer layer in the primer layer provided adjacent to the support. It is necessary to include a silane coupling agent.

Silane coupling agent> As the silane coupling agent used in the present invention, -1
Things that are known in terms of 1k, such as "Surface" Volume 21,
pp. 157-167 (1983) and B. P. Plüdemann, Silane Coupling Agent, Plenum Press (1982) 1: P1uedde
mann ″Silane Coupling Ag
ents"Plenum Press (1 9 8
2)] can be used.

The silane coupling agent suitable for the present invention is represented by the following general formula. This includes things that can be done.

X Rs-nsiYn Here, R represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms; , Y represents an organic group or a hydroxyl group that is hydrolyzed to produce a hydroxyl group, and n represents 2 or 3.

The alkyl group for X above is preferably a methyl group. In addition, when X is an organic group having a functional group that has affinity for bonding with an organic matrix polymer, examples of the functional group include vinyl group, acryloyl group, amino group, quaternary ammonium group, epoxy group, mercabuto group, chloro The organic group excluding functional groups is preferably an aliphatic hydrocarbon group, and may include an aromatic hydrocarbon group.

Preferred specific examples of organic groups having such functional groups include N-(β-aminoethyl)-T-aminobrobyl group,
T-methacryloyloxyprobyl group, N- (β-(
N-vinylbenzylamino〉ethyl]-r-aminopropyl group, γ-glycidoxypropyl group, γ-mercaptopropyl group, T-chloropropyl group, γ-anilinopropyl group, C1aHsr N(C}l -) * (C
Hz) 3- etc.

In addition, as a group that generates a hydroxyl group by hydrolysis of Y,
Alkoxy group having 1 to 5 carbon atoms (for example, methoxy group is preferred), alkoxyalkoxy group having 3 to 5 carbon atoms (for example, β-methoxyethoxy group is preferred), 2 to 5 carbon atoms
Examples include acyloxy groups (for example, acetyloxy groups are preferred), dialkylamino groups (for example, dimethylamino groups are preferred), chloro groups, trimethylsilylamino groups, and the like.

Typical silane coupling agents useful in the present invention are shown below.

(1) Unsaturated group-containing silane coupling agent: vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris(β-methoxyethoxy)silane, vinyltrichlorosilane, T-(methacrylicoxyprobyl)trimethoxysilane, vinyltriacetoxysilane Such.

(2) Amino group-containing silane coupling agent: N-(β-
aminoethyl)-T-aminobrobyltrimethoxysilane, N-(β-aminoethyl)-T-aminopropylmethyldimethoxysilane, T-aminopropyltriethoxysilane, N-phenyl-T-aminobrobyltrimethoxysilane, etc. .

(3) Epoxy group-containing silane coupling agent: T-glycidoxypropyltrimethoxysilane, T-glycidoxypropylmethyldimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, etc.

(4) Mercapto group-containing silane coupling agent: T-mercaptopropyltrimethoxysilane, T-mercaptopropylmethyldimethoxysilane, etc.

(5) Chloro group-containing silane coupling agent: T-chloropropyltrimethoxysilane, T-chloropropylmethyldimethoxysilane, methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, etc.

Primer layer> As a primer layer suitable for the present invention, JP-A-62-1
94255, which is based on epoxy resin, a layer of hardened gelatin as disclosed in JP-A No. 63-305360, and a blazer made of hardened gelatin as disclosed in Japanese Patent Application No. 63-185130. A primer layer mainly containing casein, soybean protein, and albumin, gelatin as disclosed in Japanese Patent Application No. 1-62875,
A protein/rubber composite primer layer consisting of a latex dispersion of a natural protein such as casein, soybean protein, or albumin and a diene rubber, crosslinked with a sulfur compound and/or a divalent metal salt, peroxide, or the like. Examples include a primer layer made of modified or unmodified diene rubber, a water-soluble urethane polymer, a water-dispersible urethane polymer, a primer layer mainly made of a urethane elastomer, and the like.

The above-mentioned silane coupling agent dissolved in a suitable solvent is added to these primer layer coating solutions, followed by coating and drying.

The amount of silane coupling agent added is 0.1% to 10% by weight, preferably 0.5% by weight of the amount of binder resin.
to 5% by weight.

Photosensitive layer〉 The photosensitive resin layer used in the present invention is one in which exposure to light causes a difference in solubility in a developer or changes in adhesiveness at the interface with the upper silicone rubber layer. You can use whatever you have. It may be an image type, a negative type, or a positive type.

Compounds or compositions constituting such a photosensitive layer include the following.

(^) Photopolymerizable photosensitive composition: (1) A monomer or oligomer having an olefinically unsaturated double bond group, (2) A polymeric compound having a film-forming ability, which is used as necessary, and (3) A photopolymerizable photosensitive material containing a photopolymerization initiator.

In the photosensitive resin layer containing the above components (1) to (3), a certain amount is a polymer compound in which (1) and (2) are bonded together, i.e., the side chain is photopolymerizable or photocrosslinkable and A photosensitive resin layer containing a polymer compound having an olefinic unsaturated double bond group and a film-forming ability is also suitable for use in the present invention. Further, a photosensitive resin layer in which a certain amount of the monomer or oligomer of (1) is further added to a compound in which components (1) and (2) are combined is more suitable.

The composition for the photosensitive resin layer as described above is disclosed in Japanese Patent Application No. 6, 1983, for example.
Those described in No. 3-40194 can be preferably used.

(B) Photodimerizable photosensitive composition: In the main chain or side chain of the polymer (R, SR. each represents an alkyl group, R1 and R
(2 and 2 may form a 5- or 6-membered ring), or (R: an alkyl group having 1 to 10 carbon atoms).

For example, those containing photosensitive polymers such as esters, polyamides, and polycarbonates as photosensitive groups (R: alkyl group having 1 to 10 carbon atoms) in the main chain or side chain of the polymer, for example, US patents. No. 3, 030,
No. 208, same No. 3. 707. No. 373 and No. 3
．． 453, 237); mainly photosensitive polyesters derived from (2-properidene) malonic acid compounds such as cinnamylidene malonic acid and difunctional glycols; (e.g., photopolymers as described in U.S. Pat. Nos. 2,956,878 and 3,173,787); borivinyl alcohol, starch, cellulose and Cinnamate esters of hydroxyl-containing polymers such as their analogs (e.g., U.S. Pat. No. 2.69
0. No. 966, same No. 2. 752. 372, Nos. 2, 732, 301, etc.), as well as in JP-A-58-25302 and JP-A-59-17550. Included are the polymers and the like described.

(C) A composition comprising a photocurable diazo resin or azide resin, a photosensitizer if necessary, and some filler additives: As the photocurable diazo resin, paradiazodiphenylamine, paradiazo Examples include zinc chloride double salts of condensates of formaldehyde and diazo amines such as monoethylaniline and paradiazobenzylethylaniline.

This photosensitive resin layer is essentially different from the photosensitive resin layer mentioned in (A) in that it does not contain a compound having a photopolymerizable unsaturated double bond group.

Examples of the photocurable azide resin include azidophthalate ester of polyvinyl alcohol, azidobenzoate ester, ester of styrene-maleic anhydride copolymer, and aromatic azido alcohol such as β-(4-azidophenol)ethanol. can be given.

(D) Set consisting of o-quinonediazide compounds: Particularly preferred o-quinonediazide compounds. - naphthoquinone diazide compounds, e.g. U.S. Pat.
．． No. 118, No. 2.767,092, No. 2. 7
7 2. 9 7 No. 2, No. 2.859,112, No. 2. 9 0 7. 6 6 No. 5, same No. 3,0
No. 46,110, No. 3.046.111, No. 3,
No. 046,115, No. 3.046.118, No. 3
．． 0 4 6. 1 1 9, 3.046, 1
No. 20, No. 3.046.121, No. 3,046,
No. 122, No. 3.046.123, No. 3. 0
6 1. 430, same No. 3. 1 0 2. 8
0 9, 3.106,465, 3.63
5.709, same No. 3. It is described in numerous publications including the specifications of Nos. 647 and 443, and these can be suitably used. Among these,
Particularly preferred are 0-naphthoquinonediazide sulfonic acid ester or 0-naphthoquinonediazidecarboxylic acid ester of an aromatic hydroxy compound, and 0-naphthoquinonediazide sulfonic acid amide or 0-naphthoquinonediazidecarboxylic acid amide of an aromatic amine compound.

Silicone Rubber Layer> The silicone comb layer preferably used in the present invention is a linear or partially crosslinked polydiluganosiloxane and has the following repeating units.

Here, R represents an alkyl group, an aryl group, an alkenyl group, or a combination thereof; It may have a functional group such as a group. In addition, silicone rubber may contain fine powders of inorganic substances such as silica, calcium carbonate, and titanium oxide, adhesion aids for the above-mentioned silane coupling agents, titanate coupling agents, and aluminum coupling agents, and light. A polymerization initiator may also be added.

High molecular weight polymer whose main skeleton is the above-mentioned polysiloxane (
Polysiloxane, which has a molecular weight of several tens of thousands to several hundred thousand and has a functional group at the end, is used as a raw material for silicone rubber.
This is crosslinked and cured in the following manner to obtain a silicone rubber layer. Specifically, a silane crosslinking agent represented by the following general formula is mixed into the polysiloxane having a hydroxyl group at both ends or only at one end, and if necessary, an organometallic compound such as an organotin compound is added. A catalyst such as an inorganic acid or an amine is added, and the polysiloxane and the silane crosslinking agent are heated or condensed and cured at room temperature.

R. SiX 4-n Here, n is an integer of 1 to 3, R is the same substituent as R shown above, and X represents a substituent such as -○H or 10R2. Here, R2 and R3 have the same meaning as R described above, and R2 and R3 may be the same or different. Moreover, Ac represents an acetyl group.

Other organopolysiloxanes with hydroxyl groups at the ends,
The hydrodiene polysiloxane crosslinking agent and, if necessary, the above-mentioned silane crosslinking agent are condensed and cured.

In addition, an addition-type silicone rubber layer crosslinked by an addition reaction between an S i H group and a -CH═CH group is also useful. The addition-type silicone rubber layer has the advantage that it is relatively unaffected by humidity during curing, can be crosslinked at high speed, and can easily obtain certain physical properties.

In the case of a condensation type silicone rubber layer, if carboxylic acid is present in the photosensitive resin layer, curing failure may occur depending on the crosslinking agent used, whereas with an addition type silicone rubber layer, curing is sufficient even in the presence of carboxylic acid. happens. Since carboxylic acid can be present in the photosensitive resin layer in this way, it is possible to easily design a photosensitive printing plate that can be developed with a developer mainly containing water or alkaline water.

The addition-type silicone rubber layer used here is obtained by the reaction of a polyhydrogen organopolysiloxane and a polysiloxane compound having two or more one CH=CH bonds in one molecule, and is preferably made of the following: Ingredients: (1) 100 parts by weight of polysiloxane having at least two alkenyl groups (preferably vinyl groups) directly bonded to silicon atoms in one molecule (2) At least 2 St {bonds) in one molecule Organohydrogenpolysiloxane 0.1-1
000 parts by weight (3) Addition catalyst 0. 0 0 0 0 1~1
It is obtained by curing and crosslinking a composition consisting of 0 parts by weight. The alkenyl group in part (1) may be located either at the end or in the middle of the molecular chain, and organic groups other than the alkenyl group include substituted or unsubstituted alkyl groups and aryl groups. Part (1) may optionally have a trace amount of hydroxyl group. Part (2) reacts with part (1) to form a silicone rubber layer, but also plays the role of imparting adhesiveness to the photosensitive resin layer. The hydrogen group in Part (2) may be located either at the end or in the middle of the molecular chain, and as an organic group other than hydrogen, Part (1)
Selected from similar items. The organic groups of Bokubun (1) and Abunbu (2) account for 60% of the total number of groups in terms of improving ink repellency.
It is preferable that the above group is a methyl group. The molecular structure of Part (1) and Part (2) may be straight, cyclic, or branched, and the molecular weight of at least one of them is 1. O
It is preferable that the molecular weight of the precept (1) exceeds 1.0 from the viewpoint of rubber physical properties. It is preferable that it exceeds 0 0 0.

Part (1) is exemplified by α,ω-divinylborodimethylsiloxane, (methylvinylsiloxane) (dimethylsiloxane) copolymer with methyl groups at both ends, and part (2) is exemplified by based polydimethylsiloxane, α. Examples include ω-dimethylpolymethylhydrodienesiloxane, a (methylhydrodienesiloxane)(dimethylsiloxane) copolymer having methyl groups at both ends, and cyclic polymethylhydrodienesiloxane.

The addition catalyst (3) may be arbitrarily selected from known ones, but platinum-based compounds are particularly preferred, and examples thereof include simple platinum, platinum chloride, chloroplatinic acid, and olefin-coordinated platinum. For the purpose of controlling the curing rate of these compositions, vinyl group-containing organoborisiloxanes such as tetracyclo(methylvinyl)siloxane, carbon-carbon triple bond-containing alcohols, acetone, methyl ethyl ketone,
It is also possible to add crosslinking inhibitors such as methanol, ethanol, propylene glycol monomethyl ether.

These compositions undergo an addition reaction and begin to cure when three parts are mixed, but the curing rate has the characteristic of rapidly increasing as the reaction temperature increases. Therefore, in order to lengthen the pot life of the kumikaimono until it turns into rubber and shorten the curing time on the photosensitive resin layer, the curing conditions for the kumikai are set such that the characteristics of the substrate and the photosensitive resin layer do not change. From the viewpoint of stability of adhesive force with the photosensitive resin layer, it is preferable to maintain the temperature within a range of temperature conditions and at a high temperature until completely cured.

In addition to these compositions, known adhesion promoters such as alkenyltrialkoxysilanes may be added, or organoborisiloxanes containing hydroxyl groups, silanes containing hydrolyzable functional groups (or It is also optional to add siloxane), and it is also optional to add a known filler such as silica for the purpose of improving the rubber strength.

The silicone rubber layer in the present invention serves as a printing ink repellent layer, and if the thickness is small, the ink repellency decreases,
If there are problems such as easy scratches and the thickness is large,
The thickness should be 0.5 μm because the developability will deteriorate.
5 μm is preferable.

In the photosensitive lithographic printing plate that does not require dampening water as described herein, it is optional to further coat various silicone rubber layers on the silicone rubber layer, and the adhesion between the photosensitive resin layer and the silicone rubber layer is also optional. It is also optional to provide an adhesive layer between the photosensitive resin layer and the silicone rubber layer for the purpose of increasing the strength or preventing poisoning of the catalyst in the silicone rubber composition. For surface protection of silicone rubber layer,
On the silicone rubber layer, a transparent film such as polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polyethylene terephthalate, cellophane, etc. may be laminated or a polymer coating may be applied.

<Development> The photosensitive lithographic printing plate that does not require dampening water according to the present invention is exposed to light through the original image and then treated with a developer that dissolves or swells part or all of the photosensitive resin layer in the image area, or that swells the silicone rubber layer. Developed with a compatible developer. In this case, there are cases in which the photosensitive resin layer in the image area and the silicone rubber layer thereon are removed, and cases in which only the silicone rubber layer in the image area is removed, and this can be controlled by the strength of the developer.

As the developer used in the present invention, those known as developers for photosensitive lithographic printing plates that do not require dampening water can be used. For example, aliphatic hydrocarbons (hexane, heptane,
"Isovar E, H.G" (trade name of aliphatic hydrocarbons manufactured by Esso Chemical ■, gasoline, kerosene, etc.), aromatic hydrocarbons (toluene, xylene, etc.), or halogenated hydrocarbons (triclene, etc.) The following polar solvents can be added to the solvent, or the polar solvent itself can be used.

Alcohols (methanol, ethanol, probanol, benzyl alcohol, ethylene glycol monophenyl ether, 2-methoxyethanol, 2-ethoxyethanol, carbitol monoethyl ether, carbitol monomethyl ether, triethylene glycol monoethyl ether, propylene glycol monomethyl ether) , propylene glycol monoethyl ether, dipropylene glycol monomethyl ether, polyethylene glycol monomethyl ether, propylene glycol, polypropylene glycol, triethylene glycol, tetraethylene glycol) Ketones (acetone, methyl ethyl ketone) Esters (ethyl acetate, methyl lactate, ethyl lactate) , butyl lactate,
propylene glycol monomethyl ether acetate,
Carbitol acetate, dimethyl phthalate, jetyl phthalate) Others (triethyl phosphate, tricresidyl phosphate) Also, as a developer suitable for the present invention, water may be added to the above organic solvent-based developer, or the above organic solvent may be added to the interface. Solubilized in water using an activator, etc., or an alkali agent such as sodium carbonate, monoethanolamine, diethanolamine, triethanolamine, sodium silicate, potassium silicate, sodium hydroxide, potassium hydroxide. , sodium borate, or the like, or in some cases, tap water or alkaline water can be used as the developer.

Furthermore, dyes such as crystal violet and astrazone red can be added to the developer to dye the image area simultaneously with development.

Development can be carried out by a known method, such as rubbing the printing plate with a developing pad containing a developer as described above, or pouring the developer onto the printing plate and then rubbing it with a developing brush in water. This removes the silicone rubber layer and photosensitive resin layer in the image area and exposes the surface of the primer layer, which becomes the ink receiving area, or removes only the silicone rubber layer in the image area and exposes the photosensitive layer. The bottom part becomes the ink receiving part.

<Effects of the Invention> According to the present invention, strong adhesion can be obtained between the aluminum support and the coating layer provided thereon, and the advantage is that it can withstand strong rubbing with an organic solvent-based or aqueous developer. is obtained. In particular, it has excellent water resistance, which makes it safer than organic solvent-based developers, and it can also be rubbed strongly in water-based developers, which is also advantageous in terms of the design of automatic processors. This has the advantage that even fine points and fine lines can be reproduced well.

〔Example〕

The present invention will be further explained below with reference to Examples, but the present invention is not limited to these Examples.

Preparation of aluminum substrate Thickness: 0. 10% by weight of 24 mm aluminum plate
After performing a degreasing/cleaning treatment by immersing it in a sodium hydroxide aqueous solution at 50° C. for 20 seconds, it was washed with water, and then neutralized with a 10% by weight nitric acid aqueous solution and washed with water. This aluminum plate will be referred to as substrate 8.

Substrate A was added to a 3% sodium silicate aqueous solution at 70°C for 20 minutes.
It was immersed for a second, washed with water, and dried. This aluminum plate will be referred to as substrate B.

For substrate B, commercially available S+02 30% by weight methanol colloidal silica, "Methanol Silica Sol" (manufactured by Nissan Chemical Industries, Ltd.) was diluted with a mixed solution of methanol/water = 60% by weight/40% by weight to 1.0% by weight. Apply the coating solution using a Wheeler coating machine so that the dry coating amount is 25cm/m2.
It was dried with hot air at 100°C for 1 minute. This substrate will be referred to as substrate C.

On the other hand, a commercially available aqueous colloidal silica (rcataloid-S-20LJ manufactured by Catalyst Kakai Kogyo Co., Ltd., Si0
220% by weight> was diluted with a mixed solution of methanol/water = 60% by weight/40% by weight to make a coating solution of 1.0% by weight, and a coating solution was prepared using a Wheeler coating machine so that the dry coating amount was 25cm/ml. It was dried with hot air at 100°C for 1 minute.

This substrate will be referred to as substrate D.

<Examples 1 to 3> Using substrates A to D, Example 1 and Comparative Example 1 were applied on these substrates.
A brimer layer shown in Figure 1 was applied and hardened by heating at 120°C for 3 minutes.

Example 1 I A solution consisting of a primer layer was heated to 70°C, and while stirring, the following casein powder was added and dissolved.

Next, the following ingredients were mixed into this aqueous casein solution to prepare a composition for a primer layer.

Comparative Example 1 Primer layer Example 1 A brimer layer having the same composition as the primer layer of Example 1, except that T-glycidoxypropyltrimethoxysilane was not added to the brimer layer.

Next, a photosensitive layer consisting of the following portion was coated on all of these primer layers at a dry weight of 3.0 g/m'' and dried at 100° C. for 1 minute.

Photosensitive Composition A composition for a silicone rubber layer according to the following composition was applied onto the obtained photosensitive layer at a dry weight of 2.0 g/m',
It was dried at 140°C for 2 minutes to obtain a cured silicone rubber layer.

I crushed it, rubbed it strongly with a developing pad, and developed it. The results are shown in Table-1.

A single-sided matted polypropylene film having a thickness of 9 μm was laminated on the surface of the silicone rubber layer obtained as described above to obtain a photosensitive lithographic printing plate that did not require dampening water.

A positive film was layered on this printing plate, and the film was vacuum-adhered to the Nuark FT26V UDNS ULTRA-PLUS.
After 30 counts of exposure using FLIP-TOPPLATE M8κBH, the laminate film was peeled off and 12 parts by weight of benzyl alcohol, 5 parts by weight of sodium isobrobylnaphthalene sulfonate, and 1 part by weight of triethanolamine were added.
Example 4: Immersion for 1 minute in a developer consisting of parts by weight and 82 parts by weight of water> The following was applied to the substrate C1 and substrate A shown in Example 2 and Comparative Example 2 so that the dry film thickness was 10 μm. A composition for a brimer layer was applied and cured by heating at 120° C. for 5 minutes.

The next photosensitive layer is placed on this primer layer with a dry weight of 2.5g.
/m'' and dried at 100°C for 3 minutes.

Then, add 8 parts by weight of an adhesive layer having the following composition on this photosensitive layer in a dry coating amount of 0.
．． It was coated at a concentration of 0.4 g/m' and dried at 120° C. for 1 minute.

were laminated to obtain a photosensitive lithographic printing plate that does not require dampening water. A film having a negative image was layered on this printing plate and imagewise exposed in the same manner as in Example 1, and then developed by rubbing with a developing pad impregnated with a liquid mixture consisting of 65 parts by weight of alcohol and 35 parts by weight of Isovar E. The results are shown in Table-2.

Next, on this adhesive layer, a silicone rubber layer assembly having the following composition was applied to a dry weight of 3 g/m''.
It was dried at 0° C. for 3.5 minutes to obtain a cured silicone rubber layer.

Claims (1)

[Scope of Claims] A photosensitive lithographic printing plate that does not require dampening water, in which a primer layer, a photosensitive layer, and a silicone rubber layer are provided in this order on a support, wherein the support is treated with an aqueous alkali metal silicate solution. and/or an aluminum plate coated with colloidal silica sol, wherein the primer layer contains at least one silane coupling agent.