JPH1110827A - Penetrating development photosensitive lithographic printing plate and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a penetrating development photosensitive lithographic printing plate having excellent plate wear, sensitivity and image reproducibility. SOLUTION: A lipophilic photosensitive layer 1A containing a compound having at least one addition polymerizable ethylenic double bond and a photopolymerization initiator is provided on a hydrophilized support 1. In this case, gum tape peel strength of the support 1 is 500 g/cm or less. The method for forming the penetrating development photosensitive lithographic printing plate comprises the steps of exposing an image of the plate, then penetrating the layer after the image is exposed with penetrant for penetrating to an unexposed photosensitive layer to lower adhesive properties of the layer 1A to a surface of the support 1, adding physical stimulus, and removing the unexposed part of the layer in which the properties are lowered by the penetrant from the support 1 to form a photosensitive image.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a permeation-developed photosensitive lithographic printing plate and a method for making the plate. More specifically, the present invention relates to a novel penetratively developed photosensitive lithographic printing plate capable of forming a photocurable photosensitive image without requiring an alkali developing treatment, and a plate making method thereof.

[0002]

2. Description of the Related Art Conventional photosensitive lithographic printing plates are prepared by forming a negative photosensitive layer such as a diazo resin, a photocrosslinkable polymer, a photopolymerizable composition, or a benzoquinonediazide, A positive-type photosensitive layer such as quinonediazide is applied, and a polyvinyl alcohol layer is formed as an oxygen barrier layer on the photosensitive layer, if necessary.

In order to form a photosensitive image on such a photosensitive lithographic printing plate (plate making), after exposing the printing plate imagewise, an inorganic alkali agent such as sodium silicate or sodium carbonate or diethanolamine, triethanolamine or triethanolamine is used. Using an alkaline developer containing an organic alkali agent such as ethanolamine, immersing the printing plate in this developer and applying a physical stimulus such as a brush to the photosensitive layer in the case of a negative photosensitive layer. The exposed portion is dissolved, and in the case of a positive photosensitive layer, the exposed portion is dissolved and removed to obtain a photosensitive image on the support.

When an ink liquid comprising an emulsion of a lipophilic printing ink and a printing dampening solution is supplied to the surface of the printing plate on which an image has been formed as described above, the exposed surface of the hydrophilic support and the photosensitive image are exposed. The printing ink selectively forms on the photosensitive image and the water selectively adheres on the exposed hydrophilic support surface, thereby forming a printing ink image. A printed matter can be obtained by transferring the printing ink image to an image receiving paper.

The alkali developing solution used in the above plate making process usually requires 10 to 20 L (liter) with respect to an automatic developing apparatus in order to obtain a uniform image. Generally, the same developer is repeatedly used for developing a large number of photosensitive lithographic printing plates in order to reduce the amount of the alkaline developer used. Over time, the repeatedly used alkaline developer is degraded by the photosensitive layer composition dissolved in the solution and oxygen in the air with the elapse of time, and is likely to cause poor development. In order to suppress the deterioration of the alkali developer, a complicated operation for additionally replenishing the alkali developer having a high concentration is required. Even when such a high-concentration alkaline developing solution is replenished, it has been necessary to replace it with a new solution once every several weeks in a normal plate making factory.

When the new solution is replaced, the waste solution of the used alkali developer is discharged. However, in recent years, from the viewpoint of protection of the marine environment, it has become difficult to discard the used alkali developer in the ocean. Disposal of alkaline developers has long been an important issue in the printing arts.

For these reasons, development of a photosensitive lithographic printing plate which does not require development with an alkali developing solution has been promoted. Is insufficient, resulting in poor image quality at the time of printing; lipophilic image area has insufficient durability and long-term printing operation is not possible; or hydrophilic image formation The layers were easily scratched and easily worn away;

To solve such a problem, Japanese Patent Application Laid-Open No. 8-48020 discloses an image forming layer having a lipophilic, radiation-absorbing and heat-sensitive layer formed on a support having a porous hydrophilic surface. A technique for making a lithographic printing plate by the following method using the photosensitive lithographic printing plate described above is described.

(1) The photosensitive lithographic printing plate is imagewise exposed, and heat is generated in the exposed area to enhance the adhesiveness between the image forming layer in the exposed area and the support. The layer is peeled off, exposing the porous hydrophilic surface.

(2) In a state where the transfer sheet having the image forming layer and the printing plate support are in close contact with each other, the image forming layer is irradiated with infrared light to be absorbed and converted into heat, and the image forming layer is transferred to the transfer sheet. To a printing plate support. Alternatively, the imagewise layer of the photosensitive lithographic printing plate provided in advance on the printing plate support is similarly irradiated with light and changed to heat to enhance the adhesion between the image forming layer and the printing plate support, The unexposed portion of the image forming layer is peeled off.

[0011]

SUMMARY OF THE INVENTION A photosensitive lithographic printing plate which enhances the adhesion of the image forming layer provided on the printing plate support to the support by the action of heat by exposure and removes unexposed portions. In the plate making method, when a material having a high thermal conductivity such as aluminum is used as a support of the printing plate, the heat generated by the exposure is efficiently diffused, so that the heat of the unexposed portion and the exposed portion of the image forming layer is used. There is a disadvantage that the difference in the adhesive strength to the support is small, and the sensitivity tends to be insufficient.

Further, in the conventional photosensitive lithographic printing plate, since the hydrophilic support portion is exposed, the transport of the lithographic printing plate,
Or, at the time of mounting on a printing machine, by contacting a conveying roller or a finger on the exposed hydrophilic portion,
The portion is contaminated, and as a result, it is likely to become a stain on an image of a printed matter at the time of printing. For this reason, conventionally, in order to prevent the adhesion of such stains and maintain the hydrophilicity of the non-image area, it is necessary to apply a hydrophilic polymer aqueous solution on a printing plate and dry it to provide a protective layer. It has become.

An object of the present invention is to solve the above-mentioned conventional problems and to provide a photosensitive lithographic printing plate which does not require an alkali developing solution and exhibits good sensitivity to ultraviolet to near-infrared light. I do.

Another object of the present invention is to provide a photosensitive lithographic printing plate excellent in printing properties such as ink inking property and printing resistance to printing ink.

Another object of the present invention is to provide a lithographic printing plate in which the non-image portions of the printing plate are protected until printing.

[0016]

Means for Solving the Problems The sensitized lithographic printing plate of the present invention comprises a compound having at least one addition-polymerizable ethylenic double bond on a hydrophilized support and a photopolymerization starter. Development lithographic printing plate provided with a lipophilic photosensitive layer containing a system, wherein the peel strength of the gum tape from the support determined by the peel strength measurement method using a gum tape is 500 g / cm or less. It is characterized by.

In this permeation-developed photosensitive lithographic printing plate,
The peel strength of the photosensitive layer from the support before exposure, determined by the peel strength measurement method using a gum tape, is preferably 0.5 to 2
And the peel strength of the photosensitive layer from the support after exposure is preferably 200 g / cm or more.

According to the method of the present invention, such a penetratively developed photosensitive lithographic printing plate has a photosensitive layer formed by a penetrant using a surfactant or the like or by utilizing the adhesiveness of a cover sheet. The exposed portion can be easily removed, without using an alkali developing solution, and by protecting the hydrophilic surface of the support with the unexposed portion of the photosensitive layer until printing, a clear image can be easily formed. An image can be formed.

The method of making a permeation-developed photosensitive lithographic printing plate according to the present invention comprises the steps of: exposing the photosensitive layer of the permeation-developed photosensitive lithographic printing plate of the present invention to an image by exposing the photosensitive layer with ultraviolet to near infrared light; A plate-making method for forming a photo-cured photosensitive image by removing the unexposed portion of the photosensitive layer from the support after photo-curing the photosensitive layer, A penetrant that reduces the adhesion between the layer and the surface of the support is penetrated into the photosensitive layer after image exposure, and a physical stimulus is applied to the photosensitive layer to reduce the adhesion to the support by the penetrant. Characterized by removing the unexposed portions from the support.

In the present invention, a cover sheet may be provided on the photosensitive layer of the penetrated photosensitive lithographic printing plate before or after image exposure of the penetrated photosensitive lithographic printing plate according to the present invention. When the cover sheet is later peeled off from the photosensitive layer, the unexposed portion is removed from the support by transferring the unexposed portion to the cover sheet side using the adhesiveness of the cover sheet. May be.

In this case, the cover sheet is peeled off from the photosensitive layer after the image exposure, so that a part of the unexposed portion, preferably 0.1 to 50% by weight, remains on the support side so as to remain on the support side. After that, a penetrant that penetrates into the unexposed photosensitive layer and reduces the adhesiveness between the photosensitive layer and the support surface is penetrated into the photosensitive layer after image exposure and physical stimulus is applied. It is preferable to remove from the support the remaining unexposed portion of the photosensitive layer whose adhesiveness to the support has been reduced by the penetrant.

In the present invention, the peel strength (hereinafter, referred to as "gum tape peel strength") of the support subjected to the hydrophilic treatment (hereinafter, referred to as "hydrophilic support") with a gum tape showing the surface adhesion is shown. As shown in FIG.
On the surface of the adhesive tape (SLIONTEC SLION
TAPE) 3 at 25 ° C., 5 kg / cm ² , 50 cm /
After the pressure bonding, the support 1 is fixed on the fixing base 2 and the adhesive tape 3 and the support 1 are rotated in the direction of 180 ° at 30 c / min.
m, the linear tension (g / c) obtained by dividing the force F required to pull the adhesive tape 3 apart by the width of the adhesive tape.
m). Further, as shown in FIG. 1B, the peel strength of the gum tape indicating the adhesion strength of the photosensitive layer to the hydrophilic support is such that the photosensitive layer 1A and the 3 μm-thick polyvinyl alcohol layer 1B are sequentially formed on the surface of the support 1. A laminate tape is formed, and a gum tape (SLION) is formed on the surface of the polyvinyl alcohol layer 1B.
TEC's SLION TAPE) 3 at 25 ℃, 5kg
/ Cm ² , 50 cm / min, the support 1 is fixed on the fixing table 2, and the polyvinyl alcohol layer 1 B and the photosensitive layer 1 A attached to the gum tape 3 and the support 1 are 180
In the direction of °, the adhesive tape 3
Represents the linear tension (g / cm) obtained by dividing the force F required for pulling the tape by the width of the gum tape.

[0023]

Embodiments of the present invention will be described below in detail.

The hydrophilic support used in the present invention is in a state where the surface is covered with a thin film of water (wet state) by fountain solution supplied at the time of printing. A function of preventing the adhesion of lipophilic ink particles to form a non-image area on a printed material; and, during permeation development, the photosensitive layer applied on the hydrophilized surface is easily converted into a hydrophilic support by permeation of a permeating agent. And a function that is removed from the

The hydrophilic support exhibiting such a function has a gum tape peeling strength of 500 g / cm or less when the gum tape is peeled off from the support, which is determined by the above-mentioned method for measuring the gum tape peel strength. is necessary.

Further, the peel strength of the gum tape when the unexposed photosensitive layer is peeled off from the hydrophilic support is 0.5 to 20.
0 g / cm, especially 1-150 g / cm, especially 2-1
It is preferably 100 g / cm, more preferably 10 to 100 g / cm, and the peel strength of the gum tape when peeling the photosensitive layer after exposure is preferably 150 kg / cm or more, particularly preferably 200 kg / cm or more.

More specifically, examples of the hydrophilic support according to the present invention include the following.

Aluminum plate (synthetic paper, coated paper, art) obtained by roughening (graining) the surface of an aluminum plate (hereinafter referred to as “aluminum plate”) by various methods and hydrophilizing by anodic electrolytic treatment or the like. Various paper boards such as paper,
A metal plate such as an aluminum plate, a copper plate, an iron plate, and a stainless steel plate, a wooden plate, a plastic plate such as a polyethylene terephthalate sheet, a polypropylene sheet, a polyethylene sheet, and the like, and a support having excellent dimensional stability are provided with hydrophilicity or water. The graining of the aluminum plate, provided with a swellable hydrophilic polymer layer, improves the adhesiveness of the photosensitive layer formed on the support and improves the water-accepting properties of the non-image areas of the printing plate. Done in This graining affects both the performance and durability of the printing plate, and the quality of the graining is an important factor in determining the overall quality of the printing plate.
By forming fine and uniform grain without pits,
The resulting printing plate will be given essentially good printing performance.

As such a graining method, mechanical and electric graining methods are well known and widely used in the production of lithographic printing plates. Good results can be obtained by using electrolytic graining, referred to as electrochemical graining or electrochemical roughening.

Numerous electrolytic graining methods have already been proposed for the production of lithographic printing plates, for example, US Pat. Nos. 3,755,116, 3,887,447,
Nos. 3,935,080 and 4,087,341
No. 4,201,836, No. 4,272,34
No. 2, No. 4,294,672, No. 4,301,2
No. 29, No. 4,396,468, No. 4,427,
No. 500, No. 4,468,295, No. 4,47
No. 6,006, No. 4,482,434, No. 4,5
No. 45,875, No. 4,548,683, No. 4,
Nos. 564,429, 4,581,996, 4,618,405, 4,735,696, 4,897,168 and 4,919,774. Are listed.

As the anodic electrolysis treatment after graining, an anodic oxidation treatment using an acid such as sulfuric acid or phosphoric acid is performed, and after the anodic oxidation treatment, it is preferable to use thermal silicate (silicone).
) or an electro-silicate treatment is performed.

[0032] In the anodic oxidation treatment, 0.3 g / m ² or more with respect to the surface of the aluminum plate is particularly preferred to form an anodic oxidation film of 0.5 to 10 g / m ^2. This anodized film is porous, and its pore size depends on the anodizing treatment conditions and can take a wide range of values.
0 °, preferably 10 to 500 °.

As a method for hydrophilizing the surface of an aluminum plate by anodizing and silicate treatment, it is already widely known.

For example, US Pat. No. 2,594,289 discloses a patent relating to a method of anodizing a lithographic printing plate.
No. 2,703,781, No. 3,227,63
No. 9, No. 3,511,661, No. 3,804,7
No. 31, No. 3,915, 811 and No. 3,988,
Nos. 217, 4,022,670 and 4,11
Nos. 5,211 and 4,229,266 and 4,
No. 647,346.

As the coating material used in the surface hydrophilization treatment, polyvinyl phosphonic acid, polyacrylic acid, polyacrylamide, zirconate, titanate can be used in addition to the above silicates. Patents relating to the hydrophilization treatment include US Pat. No. 2,714,066.
No. 3,181,461 and No. 3220,832
No. 3,265,504 and No. 3276,868
No. 3,549,365 and No. 4,090,88
No. 4, No. 4,153,461, No. 4,376,9
No. 14, No. 4,383,987, No. 4,399,
No. 021, No. 4,427,765, No. 4,42
No. 7,766, No. 4,448,647, No. 4,4
No. 52,674, No. 4,458,005, No. 4,
Nos. 492,616, 4,578,156, 4,689,272, 4,935,332 and European Patent 190,643.

The thickness of the hydrophilized aluminum plate thus obtained is 0.1 to 1 mm, particularly 0.15 to 1 mm.
It is preferably 0.5 mm, especially 0.15 to 0.4 mm.

When a hydrophilic polymer layer is provided on the above-mentioned various supports, a hydrophilic binder polymer cured with a crosslinking agent or the like, if necessary, is maintained in the hydrophilic polymer layer in order to maintain hydrophilicity. 5 to 100% by weight, preferably 20 to 95% by weight, more preferably 40 to 90% by weight, based on the total solid content of the hydrophilic polymer layer.

Here, the hydrophilic binder polymer is
As a side chain to a polymer composed of carbon-carbon bonds,
A networked polymer containing one or more hydrophilic functional groups such as a carboxyl group, an amino group, a phosphoric acid group, a sulfonic acid group, or a salt, a hydroxyl group, an amide group, and a polyoxyethylene group, or , Carbon atom, carbon-
Any of the carbon bonds is a carboxyl group, an amino group, a phosphoric acid group, a sulfonic acid group, or a carboxyl group, an amino group, a phosphoric acid group, Salt, a hydroxyl group, an amide group, a polymer containing one or more hydrophilic functional groups such as a polyoxyethylene group, specifically,
Poly (meth) acrylate, polyoxyalkylene, polyurethane, epoxy ring-opening addition polymerization, poly (meth) acrylic acid, poly (meth) acrylamide, polyester, polyamide, polyamine, polyvinyl, etc. Polymers such as saccharides and cellulose derivatives are exemplified. Among these, any one of a hydroxyl group, a carboxyl group or an alkali metal salt thereof, an amino group or a hydrogen halide salt thereof, a sulfonic acid group or an amine thereof, an alkali metal salt, an alkaline earth metal salt, and an amide group is added to the segment side chain. Those having a repetition of a kind or a combination of two or more kinds, and those having a polyoxyethylene group overlapped with a part of the hydrophilic functional group and the main chain segment are preferable because of high hydrophilicity. Further, those having a urethane bond or a urea bond in the main chain or side chain of the hydrophilic binder polymer are more preferable because they have high printing durability in a non-image area as well as hydrophilicity.

Hereinafter, the hydrophilic polymer layer containing the hydrophilic binder polymer of the present invention will be described more specifically. In this specification, “(meth) acrylate” indicates “acrylate and / or methacrylate”, and “(meth) acryl” indicates “acryl and / or methacryl”. In addition, the hydrophilic binder polymer according to the present invention may contain various other components described below as necessary.

In order to form a hydrophilic polymer layer containing the hydrophilic binder polymer according to the present invention, for example, first,
(Meth) acrylic acid or its alkali and amine salts,
Itaconic acid or its alkali, amine salt, 2-hydroxyethyl (meth) acrylate, (meth) acrylamide, N-monomethylol (meth) acrylamide,
N-dimethylol (meth) acrylamide, 3-vinylpropionic acid or an alkali or amine salt thereof, vinylsulfonic acid or an alkali or amine salt thereof, 2-sulfoethyl (meth) acrylate, polyoxyethylene glycol mono (meth) acrylate, 2- Hydroxyl group such as acrylamide-2-methylpropanesulfonic acid, acid phosphooxypolyoxyethylene glycol mono (meth) acrylate, allylamine or its halogenated hydrochloride, carboxyl group or its salt, sulfonic acid group or its salt, phosphoric acid or A hydrophilic homo- or copolymer is synthesized using at least one selected from a hydrophilic monomer having a hydrophilic group such as a salt, an amide group, an amino group, and an ether group.

A hydrophilic binder polymer having a functional group such as a hydroxyl group, a carboxyl group, an amino group or a salt thereof, or an epoxy group utilizes these functional groups to add ethylene such as a vinyl group, an allyl group, and a (meth) acryl group. A polymer containing an unsaturated group into which a polymerizable unsaturated group or a ring-forming group such as a cinnamoyl group, a cinnamylidene group, a cyanosinnamylidene group, or a p-phenylenediacrylate group is introduced is obtained. If necessary, a monofunctional or polyfunctional monomer copolymerizable with the unsaturated group, a polymerization initiator described below, and other components described below are added, and the mixture is dissolved in an appropriate solvent to prepare a coating solution. This is applied on a support and subjected to three-dimensional crosslinking after drying or also as drying.

The hydrophilic binder polymer containing an active hydrogen such as a hydroxyl group, an amino group or a carboxyl group may be used together with an isocyanate compound or a blocked polyisocyanate compound and other components described later together with an active hydrogen such as methyl ethyl ketone, propylene glycol monomethyl ether acetate, cyclohexanone, or the like. A coating solution is prepared by adding the solution to a non-containing solvent, and the solution is coated on a support, and dried or three-dimensionally crosslinked after drying.

A monomer having a glycidyl group such as glycidyl (meth) acrylate and a carboxyl group such as (meth) acrylic acid can be used in combination as a copolymer component of the hydrophilic binder polymer. Is a hydrophilic binder polymer having a glycidyl group as a crosslinking agent, α, X-alkane or alkenedicarboxylic acid such as 1,2-ethanedicarboxylic acid or adipic acid, 1,2,3-propanetricarboxylic acid, Polycarboxylic acids such as merit acid, 1,2-ethanediamine, diethylenediamine, diethylenetriamine, polyamine compounds such as α, X-bis- (3-aminopropyl) -polyethylene glycol ether, ethylene glycol, propylene glycol, diethylene glycol, tetraethylene A polyhydroxy compound such as oligoalkylene or polyalkylene glycol such as tylene glycol, trimethylolpropane, glycerin, pentaerythritol and sorbitol can be used, and three-dimensional cross-linking can be carried out using a ring opening reaction with these.

The hydrophilic binder polymer having a carboxyl group or an amino group may be used as a crosslinking agent such as ethylene or propylene glycol diglycidyl ether, polyethylene or polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether,
Three-dimensional crosslinking can be performed using an epoxy ring-opening reaction using a polyepoxy compound such as 1,6-hexanediol diglycidyl ether and trimethylolpropane triglycidyl ether.

Polysaccharides such as cellulose derivatives, polyvinyl alcohol or partially saponified products thereof, glycidol homo- or copolymers, or hydrophilic binder polymers based on these are used for the above-mentioned functional groups capable of undergoing a cross-linking reaction by utilizing the hydroxyl groups contained therein. Groups can be introduced and three-dimensionally cross-linked by the methods described above.

A polyol or polyamine containing a hydroxyl group or an amino group at the polymer terminal, such as polyoxyethylene glycol, and 2,4-tolylene diisocyanate;
Using a polymer in which an ethylene addition polymerizable unsaturated group or a ring-forming group is introduced into a hydrophilic polyurethane precursor synthesized from a polyisocyanate such as 2,6-tolylene diisocyanate, 1,6-hexamethylene diisocyanate, or isophorone diisocyanate. Three-dimensional crosslinking can be performed by the method described above.

Here, when the synthesized hydrophilic polyurethane precursor has an isocyanate group terminal, glycerol mono (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, N -Monomethylol (meth) acrylamide, N-dimethylol (meth) acrylamide,
(Meth) acrylic acid, cinnamic acid, a compound having an active hydrogen such as cinnamic alcohol, and having a hydroxyl group or amino group terminal, (meth) acrylic acid, glycidyl (meth) acrylate, 2-isocyanatoethyl ( (Meth) acrylate and the like.

Further, after applying a polybasic acid and a polyol or a polybasic acid and a polyamine, a three-dimensional crosslinking is carried out by heating, or a water-soluble colloid-forming compound such as casein, glue or gelatin is three-dimensionally crosslinked by heating. A hydrophilic binder polymer having a structure may be formed.

In addition, hydroxyl or amino groups such as homo- or copolymers synthesized from hydroxyl-containing monomers such as 2-hydroxyethyl (meth) acrylate and vinyl alcohol and allylamine, polysaccharides such as partially saponified polyvinyl alcohol and cellulose derivatives, and glycidol homo or copolymers; There is also a method of forming a three-dimensionally crosslinked hydrophilic binder polymer by reacting a group-containing hydrophilic polymer with a polybasic acid anhydride having two or more acid anhydride groups in one molecule.

Here, polybasic acid anhydrides include ethylene glycol bis anhydro trimellitate, glycerol tris anhydro trimellitate,
3,3a, 4,5,9b hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-C] furan-1,3-dione, 3,3 ′,
4,4'-diphenylsulfonetetracarboxylic dianhydride, 1,2,3,4-butanetetracarboxylic dianhydride and the like are exemplified.

An active hydrogen-containing compound such as a polyamine or a polyol having an isocyanate group at the end thereof and an active hydrogen-containing compound such as a polyamine or a polyol are dissolved or dispersed in a solvent and coated on a support to remove the solvent. Can be cured at a temperature at which they do not break down to form a three-dimensional crosslink. In this case, hydrophilicity may be imparted by introducing a hydrophilic functional group into either or both segments and side chains of the polyurethane or the active hydrogen-containing compound. The segment expressing hydrophilicity and the functional group may be appropriately selected from those described above.

Here, the polyisocyanate compounds that can be used include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, and 4,4 ′
-Diphenylmethane diisocyanate, 1,5-naphthalenediisocyanate, tolidine diisocyanate,
Examples thereof include 1,6-hexamethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, lysine diisocyanate, triphenylmethane triisocyanate, and bicycloheptane triisocyanate.

In some cases, it is preferable to block (is mask) the isocyanate group by a known method in order to prevent the isocyanate group from changing during handling before and after the coating step. In this case, for example, Keiji Iwata, "Plastic Materials Course Polyurethane Resin"
Sodium acid sulfite, aromatic secondary according to Nikkan Kogyo Shimbun (1974), pp. 51-52, "Polyurethane Resin Handbook" by Keiji Iwata, Nikkan Kogyo Shimbun (1987), pp. 98, 419, 423, 499, etc. Masking agents such as amines, tertiary alcohols, amides, phenols, lactams, heterocyclic compounds, and ketoxime can be used. Of these, isocyanate regeneration temperature is particularly low and hydrophilic is preferable, and examples thereof include sodium acid sulfite.

An addition-polymerizable unsaturated group may be introduced into any of the above-mentioned unblocked or blocked polyisocyanates and used for strengthening crosslinking or reacting with a lipophilic component. The degree of the degree of cross-linking, such as the average molecular weight between cross-links, varies depending on the type of segment used, the type and amount of the associative functional group, and the like, but may be determined according to the required printing durability. Normal,
The average molecular weight between crosslinks is set in the range of 500 to 50,000.
If this value is shorter than 500, it tends to be brittle. If it is longer than 50,000, it may be unfavorable because it swells with fountain solution and printing durability is impaired. On the balance between printing durability and hydrophilicity, the average molecular weight between crosslinks is 800 to 30,000, particularly 1000.
About 10,000 is practical.

The hydrophilic binder polymer of the present invention includes:
Further, the following monofunctional monomers and polyfunctional monomers may be used in combination.

That is, Shinzo Yamashita and Tosuke Kaneko, "Crosslinking Agent Handbook", Taiseisha Publishing Co., Ltd. (1981), Kiyomi Kato, "Ultraviolet Curing System", published by Sogo Gijutsu Center (1989), Kiyomi Kato, "UV / EB Curing". Handbook (raw material edition) "Polymer Publishing Association (1985), supervised by Kiyoshi Akamatsu," Practical technology of new photosensitive resin ", CMC, pp. 102-114 (198)
7), N, N'-methylenebisacrylamide, (meth) acryloylmorpholine, vinylpyridine, N-methyl (meth) acrylamide, N, N-
Dimethyl (meth) acrylamide, N, N-dimethylaminopropyl (meth) acrylamide, N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, N, N-dimethylaminoneopentyl ( Meth) acrylate, N-vinyl-2-pyrrolidone, diacetone acrylamide, N
-Methylol (meth) acrylamide, p-styrene sulfonic acid and its salt, methoxytriethylene glycol (meth) acrylate, methoxy tetraethylene glycol (meth) acrylate, methoxy polyethylene glycol (meth) acrylate (number average molecular weight of PEG 4
00), methoxypolyethylene glycol (meth) acrylate (PEG number average molecular weight 1000), butoxyethyl (meth) acrylate, phenoxyethyl (meth) acrylate, phenoxydiethylene glycol (meth) acrylate, phenoxypolyethylene glycol (meth) acrylate, nonylphenoxy Ethyl (meth) acrylate, dimethylol tricyclodecane di (meth) acrylate, polyethylene glycol di (meth) acrylate (PEG having a number average molecular weight of 40
0), polyethylene glycol di (meth) acrylate (number average molecular weight of PEG 600), polyethylene glycol di (meth) acrylate (number average molecular weight of PEG 1)
000), polypropylene glycol di (meth) acrylate (number average molecular weight of PEG 400), 2,2-bis [4- (methacryloxyethoxy) phenyl] propane, 2,2-bis [4- (methacryloxy diethoxy) phenyl ] Propane, 2,2-bis [4- (methacryloxypolyethoxy) phenyl] propane or an acrylate thereof, β- (meth) acryloyloxyethyl hydrogendiene phthalate, β- (meth) acryloyloxyethyl hydrogen succinate, polyethylene Or polyphenylene glycol mono (meth) acrylate, 3-chloro-2-hydroxypropyl (meth)
Acrylate, 1,3-butylene glycol di (meth)
Acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, trimethylolpropanetri (meth) acrylate, tetramethylolmethanetri (meth) acrylate, tetramethylolmethanetetra (meth) acrylate, Isobornia (meth) acrylate, lauryl (meth) acrylate, tridecyl (meth) acrylate,
Stearyl (meth) acrylate, isodecyl (meth)
Acrylate, cyclohexyl (meth) acrylate,
Tetrafurfuryl (meth) acrylate, benzyl (meth) acrylate, mono (2-acryloyloxyethyl) acid phosphate or its methacrylic body, glycerin mono- or di (meth) acrylate, tris (2-
(Acryloxyethyl) isocyanurate or its methacrylic body, N-phenylmaleimide, N- (meth) acryloxysuccinimide, N-vinylcarbazole, divinylethyleneurea, divinylpropyleneurea and the like.

The hydrophilic polymer layer used in the present invention has a particle diameter of 1 to improve the water retention of the dampening solution.
0-40 nm colloidal silica, particle size 10-100 n
m of colloidal alumina, acetic acid, formic acid, citric acid, tartaric acid, malic acid, carboxylic acid such as itaconic acid or a carboxylate alone or a mixture thereof with respect to the total solid content of the hydrophilic polymer layer is 0 to 90% by weight, preferably 0 to 80% by weight can be contained.

Further, in the hydrophilic polymer layer,
For the purpose of improving the coating properties of the photosensitive layer, a suitable surfactant is added to the total solid content of the hydrophilic polymer layer coating solution.
It can be contained at a blending ratio of 0.01 to 10% by weight.

The thickness of the hydrophilic polymer layer used in the present invention is 0.1 to 100 μm, preferably 0.2 to 50 μm.
m, more preferably 0.5 to 20 μm. In addition, the thickness of the various supports forming such a hydrophilic polymer layer is 25 μm to 1 mm, particularly 50 to 500 μm,
In particular, the thickness is preferably 50 to 300 μm.

Next, in the present invention, a compound having at least one addition-polymerizable ethylenic double bond contained in the photosensitive layer formed on the hydrophilic support (hereinafter referred to as "ethylenic compound"). ) Will be described.

The ethylenic compound is a monomer having an ethylenically unsaturated bond such that it undergoes addition polymerization and cures by the action of a photopolymerization initiation system. , Is a concept opposite to the so-called polymer, therefore, in addition to monomers in a narrow sense, dimers,
It also includes trimers and oligomers. ), A high film strength that penetrates into the unevenness or pores on the surface of the hydrophilic support and enhances the adhesiveness between the photosensitive layer and the hydrophilic support by light curing during exposure, and resists physical stimulation during development. On the other hand, before photo-curing, on the other hand, the adhesiveness to the hydrophilic support is relatively small, and the adhesive tape has the peel strength specified in the present invention, and therefore, in the unexposed portion of the photosensitive layer, Is required to be easily removed from the hydrophilic support by the penetration of a penetrating agent during development so that the hydrophilic surface of the support can be exposed.

Further, this ethylenic compound has a peel strength of 0.5 to 200 g / cm, preferably 1 to 15 g / cm, when peeled from the hydrophilic support in an unexposed state.
When the photosensitive layer adjusted to 0 g / cm, more preferably 2 to 100 g / cm, and still more preferably 10 to 100 g / cm, is exposed to light, the light-exposed portion of the photosensitive layer is Gum tape peel strength is 150g / cm
As described above, a function of preferably greater than 200 g / cm is desired.

If the unexposed photosensitive layer has a remarkably low peel strength, the photosensitive layer is peeled from the hydrophilic support when the photosensitive lithographic printing plate is handled.
On the other hand, when the temperature is extremely high, a defect during development (remaining film in the non-image portion) occurs.

Furthermore, if the peel strength of the exposed portion of the hydrophilic support is extremely low, the sensitivity is lowered. If the peel strength is extremely low, no photocured image is formed.

Accordingly, for the purpose of satisfying the above-mentioned required characteristics, in the present invention, as the ethylenic compound, an ethylenic compound having a urethane skeleton having the following specific structure, phosphoric acid and a compound containing a (meth) acryloyl group, It is preferable to use one or more of an esterified product of the above or hydroxy (mono / or poly) alkyleneoxy (meth) acrylate (hereinafter, these three types of ethylenic compounds are referred to as “specific ethylenic compounds”). ").)

The ethylenic compound having a urethane skeleton is characterized by having a urethane skeleton in the molecule, and has a function of exhibiting high adhesion to a support and high film strength. Among them, those having a partial structure represented by the following general formula (I) are preferably used.

[0067]

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(In the general formula (I), Y ¹ and Y ² each independently represent an acryloyl group or a methacryloyl group. X represents an integer of 0 to 2, y represents an integer of 0 to 3, and z represents an integer of 0 to 3. Represents an integer of 0 to 3, provided that y + zx = 1, and A ³ represents an alkylene group having 1 to ³ carbon atoms or a direct bond.) It has a partial structure represented by the general formula (I). As the compound, a urethane compound obtained by reacting an organic diisocyanate compound or a trimer thereof with a (meth) acryloyl group-containing hydroxy compound is usually used.

Here, examples of the organic diisocyanate compound include aliphatic diisocyanates such as hexamethylene diisocyanate and trimethylhexamethylene diisocyanate, alicyclic diisocyanates such as cyclohexane diisocyanate and isophorone diisocyanate, and aromatic diisocyanates such as tolylene diisocyanate and diphenylmethane diisocyanate. Is mentioned. Also,
Examples of the (meth) acryloyl group-containing hydroxy compound to be reacted with these organic diisocyanate compounds or trimers thereof include those represented by the following general formula (II).

[0070]

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(In the formula, x, z, y, and A ³ have the same meanings as those in the formula (I).) Examples of such a (meth) acryloyl group-containing hydroxy compound include the following. .

[0072]

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Representative urethane compounds obtained by reacting the above-mentioned organic diisocyanate compound or its trimer with a (meth) acryloyl group-containing hydroxy compound are represented by the following general formulas (III) to (VI). Show.

[0074]

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[0075]

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[0076]

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Preferred examples of the ethylenic compound having a urethane skeleton used in the present invention include the following compound E-
1 to E-11.

[0078]

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[0079]

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[0080]

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[0081]

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These ethylenic compounds having a urethane skeleton are used singly or as a mixture of two or more, and are usually used in an amount of 10 to 9 relative to the total solid content of the photosensitive layer.
0% by weight, preferably 20 to 70% by weight. If the compounding ratio is less than 10% by weight, the printing durability is reduced, and if it is more than 90% by weight, the developing property of the unexposed photosensitive layer due to the penetrant tends to decrease, and in any case, it is not preferable.

The phosphoric ester of the (meth) acryloyl group-containing compound among the specific ethylenic compounds is not particularly limited as long as it is an ester of phosphoric acid and the (meth) acryloyl group-containing compound. Examples of such compounds include compounds represented by the following general formula (VII). Such compounds are effective in improving the sensitivity and printing durability, and in enhancing the peeling-off property of unexposed portions during development.

[0084]

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Among the compounds represented by the general formula (VII), those having n of 1 to 10 are particularly preferable in terms of improving the printing durability and the removability of the non-image area. Preferred specific examples of the compound represented by the general formula (VII) include methacryloxyethyl phosphate, bis (methacryloxyethyl) phosphate and the like.

[0086] Such a phosphoric ester compound is as follows.
The seeds are used alone or as a mixture of two or more kinds, and the content is usually 0.1 to 30% by weight, preferably 0.2 to 25% by weight of the total solids of the photosensitive layer. If the proportion is less than 0.1% by weight, the adhesiveness to the support and the developability of the unexposed photosensitive layer are inferior. If it exceeds 30% by weight, the sensitivity may be deteriorated.

Further, hydroxy (mono / poly) alkyleneoxy (meth) acrylate as a specific ethylenic compound has a function of improving adhesiveness, sensitivity, and developability of an unexposed photosensitive layer. , The following general formula (V
Those represented by III) are preferred.

[0088]

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(In the general formula (VIII), R ⁹ represents a hydrogen atom or a methyl group, A ⁶ represents an optionally branched alkylene group having 1 to 6 carbon atoms which may be substituted by halogen, p represents an integer of 2 or more.) In the general formula (VIII), A ⁶ is preferably an alkylene group having 2 to 4 carbon atoms which may be branched, and the alkylene group may be substituted with halogen. In such a case, the substituent is preferably a chlorine atom. More preferably, A ⁶ is unsubstituted and has 2 carbon atoms.
Or three alkylene groups which may be branched, that is, polyethylene glycol mono (meth) acrylate or polypropylene glycol mono (meth) acrylate are preferred. In the general formula (VIII), p is not a problem as long as it is an integer of 2 or more. In particular, it is most preferable that p is 5 to 50 in terms of adhesion to a support, sensitivity, and developability. ,preferable.

Such hydroxy (mono / poly)
The alkyleneoxy (meth) acrylate is used singly or as a mixture of two or more, and the content thereof is not particularly limited, but is usually 0.1 to 10% based on the total solid content of the photosensitive layer. 30% by weight, preferably 0.2 to
It is 25% by weight, more preferably 0.3 to 20% by weight. When the compounding ratio is less than 0.1% by weight, the adhesiveness to the support and the developability of the unexposed photosensitive layer are inferior.
If the amount is more than the percentage by weight, the sensitivity tends to deteriorate.

The phosphoric ester of the (meth) acryloyl group-containing compound and the hydroxy (mono / poly) alkyleneoxy (meth) acrylate compound as the specific ethylenic compound have effective functions. On the other hand, the phosphoric acid ester of a (meth) acryloyl group-containing compound should be applied to a grained grain that has not been subjected to hydrophilization of silicate and an aluminum plate that has only been subjected to anodic oxidation, as a hydrophilic support. Preferably, the hydroxy (mono / poly) alkyloxy (meth) acrylate compound is applied to a grained and anodized aluminum plate that has been subjected to a hydrophilization treatment with silicate as a hydrophilic support.

In the present invention, an ethylenic compound other than the above specific ethylenic compound may be used in combination.
In particular, it is desirable to use a polyfunctional ethylenic compound having two or more ethylenic double bonds together with the above specific ethylenic compound.

Examples of such polyfunctional ethylenic compounds include, for example, an ester of an aliphatic polyhydroxy compound and an unsaturated carboxylic acid, an ester of an aromatic polyhydroxy compound and an unsaturated carboxylic acid, an aliphatic polyhydroxy compound, and an aromatic polyhydroxy compound. And esters obtained by an esterification reaction of a polyvalent hydroxy compound such as an aromatic polyhydroxy compound with an unsaturated carboxylic acid and a polyvalent carboxylic acid.

Here, the ester of the aliphatic polyhydroxy compound and the unsaturated carboxylic acid is not particularly limited, but ethylene glycol diacrylate, triethylene glycol diacrylate, trimethylolpropane triacrylate, trimethylolethane triacrylate, Acrylic esters of aliphatic polyhydroxy compounds such as pentaerythritol diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, glycerol acrylate, and these exemplified compounds Methacrylates instead of acrylates, and itaconates Instead itaconic acid esters, maleic acid esters, and the like was replaced with crotonic acid ester or maleate was replaced crotonate.

Examples of the ester of the aromatic polyhydroxy compound and the unsaturated carboxylic acid include hydroquinone diacrylate, hydroquinone dimethacrylate, resorcin diacrylate, resorcin dimethacrylate,
Acrylic esters and methacrylic esters of aromatic polyhydroxy compounds such as pyrogallol triacrylate.

The ester obtained by the esterification reaction of the unsaturated carboxylic acid, polycarboxylic acid and polyhydroxy compound is not necessarily a single substance, but typical examples include acrylic acid and phthalic acid. Examples thereof include condensates of acid and ethylene glycol, condensates of acrylic acid, maleic acid and diethylene glycol, condensates of methacrylic acid, terephthalic acid and pentaerythritol, condensates of acrylic acid, adipic acid, butanediol and glycerin.

Other polyfunctional ethylenic compounds used in the present invention include epoxy acrylates such as an addition product of a diepoxy compound and hydroxyethyl acrylate, acrylamides such as ethylenebisacrylamide, and allyls such as diallyl phthalate. Esters and vinyl group-containing compounds such as divinyl phthalate are effective.

Among the ethylenic compounds, polymers having an ethylenic double bond in the main chain include, for example, polyesters obtained by a polycondensation reaction between an unsaturated divalent carboxylic acid and a dihydroxy compound, and unsaturated divalent carboxylic acids. And polyamides obtained by a polycondensation reaction between amides and diamines. Polymers having an ethylenic double bond in the side chain are divalent carboxylic acids having a double bond in the side chain, for example, condensation of itaconic acid, propylidene succinic acid, ethylidene malonic acid and the like with a dihydroxy compound or a diamine compound. There are polymers. Further, a polymer having a functional group having a reactive activity such as a hydroxy group or a methyl halide group in a side chain, for example, polyvinyl alcohol, poly (2-hydroxyethyl methacrylate), polyepichlorohydrin, etc., and acrylic acid, methacrylic acid, crotonic acid A polymer obtained by a polymer reaction with an unsaturated carboxylic acid such as described above can also be suitably used.

The mixing ratio of such an ethylenic compound is from 5 to 98% by weight, especially 20% by weight, based on the total solid content of the photosensitive layer.
It is preferably from 80 to 80% by weight, particularly preferably from 20 to 70% by weight.

Next, the photopolymerization initiation system contained in the photosensitive layer according to the present invention will be described.

As the photopolymerization initiation system, any one can be used as long as it can initiate the polymerization of the above-mentioned ethylenic compound. Among them, particularly those which are sensitive to light in the ultraviolet to near infrared region. Those having properties are preferably used.

In the present invention, examples of the photopolymerization initiation system which absorbs ultraviolet light to generate radicals include dialkyl described in Fine Chemicals, March 1, 1991, Vol 20, No. 4, pages 16 to 26. Acetophenone type, benzyl dialkyl ketal type, benzoin, benzoin alkyl ether type, thioxanthone derivative, acylphosphine oxide type, etc., and JP-A-58-4030.
No. 2, JP-B-45-37377, hexaarylbiimidazoles, s-trihalomethyltriazines, and titanocenes described in JP-A-59-152396 can be used.

Examples of the photopolymerization initiation system sensitive to visible light from ultraviolet to 550 nm include, for example, a system of hexaarylbiimidazole, a radical generator and a dye (Japanese Patent Publication No.
JP-A-37377), a system of hexaarylbiimidazole and (p-dialkylaminobenzylidene) ketone (JP-A-47-2528, JP-A-54-155292).
JP-A-48-15184, a system of a cyclic cis-α-dicarbonyl compound and a dye (JP-A-48-84183), and a system of a substituted triazine and a merocyanine dye (JP-A-54-151024).
JP-A-52-1), a system of ketocoumarin and an activator (JP-A-52-1)
12681, JP-A-58-15503, JP-A-60-15
-88005), a system of a substituted triazine and a sensitizer (JP-A-58-29803, JP-A-58-40302).
JP-A-59-56403), a system of biimidazole, styrene derivative, and thiol (JP-A-59-56403), a sensitizer containing a dialkylaminophenyl group and a biimidazole (JP-A-2-69, JP-A-57-57). 168880, JP-A-5-107761, JP-A-5-210240,
JP-A-4-288818, JP-A-59-140203, JP-A-59-1
No. 89340), titanocene-based systems (Japanese Unexamined Patent Publication No.
No. 152396, JP-A-61-151197, JP-A-63-10602, JP-A-63-41484, JP-A-2-291, JP-A-3-12403, JP-A-3-103
20293, JP-A-3-27393, JP-A-3-5
2050), a system combining a titanocene and a xanthene dye and an addition-polymerizable ethylenically saturated double bond-containing compound having an amino group or a urethane group (JP-A-4-221958, JP-A-4-219756) ) And the like.

Preferable examples of the photopolymerization initiation system sensitive to light of ultraviolet to 550 nm include a sensitizing dye having an absorption at a wavelength of 400 to 500 nm, and 2,2′-bis (o-chlorophenyl) -4,4 ′. , 5,5'-Tetraphenylbiimidazole, 2,2'-bis (o-chlorophenyl) -4,
4 ′, 5,5′-tetra (p-carbethoxyphenyl) biimidazole, 2,2′-bis (o-chlorophenyl) -4,4 ′, 5,5′-tetra (p-bromophenyl) biimidazole Hexaarylbiimidazoles such as 2,2'-bis (o-chlorophenyl) -4,4 ', 5,5'-tetra (o, p-dichlorophenyl) biimidazole, and 2-mercaptobenzthiazole;
A composite photopolymerization initiator comprising an organic thiol compound such as 2-mercaptobenzoxazole or 2-mercaptobenzimidazole, or a sensitizing dye having an absorption at a wavelength of 400 to 500 nm and dicyclopentadienyl-Ti-bis-2, 6-difluoro-3- (pyrrol-1-yl)
-Phenyl-1-yl, dicyclopentadienyl-Ti
-Bis-2,3,5,6-tetrafluorophenyl-1
-Yl, di-cyclopentadienyl-Ti-bis-2,
Titanocene compounds such as 3,4,5,6-pentafluorophenyl-1-yl and the like, and further, a complex photopolymerization initiator comprising a dialkylaminophenyl compound such as ethyl p-diethylaminobenzoate and Michler's ketone are exemplified.

The above dyes for sensitizing hexabiimidazole include, for example, JP-A-2-69, JP-A-57-168088, and JP-A-5-107761.
JP, JP-A 5-210240, JP-A 6-1
Sensitizing dyes described in JP-A-16313 can be mentioned.

Examples of dyes for sensitizing titanocene include, for example, JP-A-6-295061 and JP-A-6-29506.
No. 301208, Japanese Unexamined Patent Publication No. 7-219223,
Sensitizing dyes described in JP-A-7-281434 and JP-A-8-6245 can be exemplified.

The photopolymerization initiation system sensitive to visible to near-infrared light of 550 nm or more includes, for example, a system of a substituted triazine and a squarium salt dye (Japanese Patent Publication No. 8-2073).
No. 4, JP-A-2-306247), a system of a substituted triazine and a cyanine dye (JP-A-2-189548), and a system of an azinium compound and a cyanine dye or a squarium salt dye (JP-A-63-142346). Gazette).

The proportion of such a photopolymerization initiation system is from 0.1 to 50% by weight, especially from 0.2 to 40% by weight, especially from 0.5 to 30% by weight, based on the total solid content of the photosensitive layer. It is preferred that

In the photopolymerization initiation system, a sensitizer is used in an amount of 0.01 to 20.
% By weight, in particular from 0.05 to 10% by weight, and preferably from 0.1 to 80% by weight, in particular from 0.5 to 50% by weight, of the active agent.

In the photosensitive layer according to the present invention, in addition to the ethylenic compound and the photopolymerization initiation system, an organic binder may be further used as a binder for modifying the photosensitive layer and improving physical properties after photocuring. It preferably contains a molecular substance (hereinafter, referred to as “polymer binder”).

In this case, the polymer binder to be used can be selected according to the compatibility, the film-forming property, the adhesion and the purpose of improvement.

As specific examples of the polymer binder, for example,
(Meth) acrylic acid, (meth) acrylic acid ester,
(Meth) acrylamide, maleic acid, (meth) acrylonitrile, styrene, vinyl acetate, vinylidene chloride,
Examples thereof include homo- or copolymers of maleimide and the like, polyethylene oxide, polyvinyl pyrrolidone, polyamide, polyurethane, polyester, polyether, polyethylene terephthalate, acetyl cellulose, and polyvinyl butyral. Among them, a copolymer containing at least one (meth) acrylic acid ester and (meth) acrylic acid as a copolymer component is preferable. The preferred acid value of the polymer binder having a carboxyl group in the molecule is 10 to 250, and the preferred weight average molecular weight (hereinafter abbreviated as “Mw”) is 5,000 to 500,000.

It is desirable that these polymer binders have an unsaturated bond in a side chain, and particularly, those represented by the following general formulas (IXa) to (IXa).
It preferably has at least one type of unsaturated bond represented by Xc).

[0114]

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(Wherein, R ¹⁰ represents a hydrogen atom or a methyl group. R ^{11 to} R ¹⁵ each independently represent a hydrogen atom, a halogen atom, an amino group, a dialkylamino group, a carboxyl group, an alkoxycarbonyl group, Having a sulfo group, a nitro group, a cyano group, an alkyl group which may have a substituent, an aryl group which may have a substituent, an alkoxy group which may have a substituent, and a substituent An aryloxy group which may be substituted, an alkylamino group which may have a substituent, an arylamino group which may have a substituent, an alkylsulfonyl group which may have a substituent, or a substituent An arylsulfonyl group optionally having
Represents an oxygen atom, a sulfur atom, an imino group, or an alkylimino group. The substituent such as the alkyl group which may have the substituent is not particularly limited as long as the reactivity of the carbon-carbon double bond is not extremely reduced.
It is selected from a halogen atom, an alkyl group, a phenyl group, a cyano group, a nitro group, an alkoxy group, an alkylthio group, a dialkylamino group, and the like.

[0116] Of these, those represented by the general formula (IXa), R ¹⁰ is a hydrogen atom or a methyl group, R ¹¹
And R ¹² are more preferably each independently a hydrogen atom, a lower alkyl group, an alkoxy group, a dialkylamino group, or a cyano group, and those represented by the general formula (IXb) include R ¹¹ and R ¹² Are each independently a hydrogen atom, a halogen atom, a lower alkyl group, a carboxyl group, an alkoxycarbonyl group or a cyano group, and R ¹³ is a hydrogen atom, a halogen atom, a lower alkyl group, a carboxyl group, an alkoxycarbonyl group, or a cyano group. It is more preferred that R ¹⁴ and R ¹⁵ are each independently a hydrogen atom, a halogen atom, or a lower alkyl group, and those represented by general formula (IXc) include R ¹¹ , R ¹² and R More preferably, each of ¹³ is independently a hydrogen atom, a halogen atom, a lower alkyl group, a carboxyl group, an alkoxycarbonyl group, or a cyano group. Further, from the easiness of the addition reaction of the carbon-carbon double bond in the general formulas (IXa) to (IXc), the general formula (IX
In a) at least two hydrogen atoms of R ¹⁰ to R ^12, in the general formula (IXb) and (IXc) R ¹¹ ~
Those in which at least two of R ¹³ are hydrogen atoms are particularly preferred.

The methods for synthesizing these compounds are roughly classified into the following two methods.

(Synthesis Method 1) An inert organic solvent solution of a polymer binder having a carboxyl group in the molecule (for example, alcohol, ester, aromatic hydrocarbon, aliphatic hydrocarbon, etc.). A method of reacting an unsaturated compound having an epoxy group with an epoxy group under a reaction condition of about 80 to 120 ° C. for about 1 to 50 hours.

The ratio of the carboxyl group to be reacted with the epoxy group-containing unsaturated compound is not particularly limited as long as the effect of the present invention can be achieved. It is preferably from 20 to 80 mol%, more preferably from 30 to 70 mol%. Within the above range, the developing property is good and the adhesive property is good.

The unsaturated epoxy group-containing compound used in the production of the ethylenic polymer binder having an unsaturated group in the side chain includes:
A compound having at least one addition-polymerizable unsaturated bond and an epoxy group in one molecule.

Examples of the unsaturated compound containing an epoxy group include glycidyl (meth) acrylate, allyl glycidyl ether, α-ethyl glycidyl acrylate, crotonyl glycidyl ether, glycidyl crotonate, glycidyl isocrotonate, monoalkyl itaconate monoglycidyl ester And aliphatic epoxy group-containing unsaturated compounds such as monoalkyl fumarate monoglycidyl ester, monoalkyl maleate monoglycidyl ester, and the following structural formulas (Xa) to (Xn)
And an alicyclic epoxy group-containing unsaturated compound represented by the formula:

[0122]

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[0123]

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(In each formula, R ¹⁶ , R ¹⁷ and R ¹⁸ each independently represent a hydrogen atom or a methyl group. R ¹⁹ , R ²⁰ and R ²¹ each independently represent a divalent group having 1 to 6 carbon atoms. of .q showing a divalent hydrocarbon group .R ^22, R ²³ is 1 to 10 carbon atoms each independently of an aliphatic saturated hydrocarbon group, r represents an integer of 0.) the epoxy Specific examples of preferred compounds containing a group-containing unsaturated compound include glycidyl methacrylate, allyl glycidyl ether, 3,4-epoxycyclohexylmethyl acrylate, and the like. Among these, particularly preferred compounds are allyl glycidyl ether and 3,
4-epoxycyclohexylmethyl acrylate.

(Synthesis Method 2) The above general formulas (IXb) and (IXc)
Copolymerization of an unsaturated carboxylic acid with a compound having at least two types of unsaturated bonds of at least one type of unsaturated bonds having low reactivity and at least one type of unsaturated bonds having higher reactivity as shown in How to combine.

Specific examples of the compound having an unsaturated group represented by the general formula (IXb) include allyl (meth) acrylate, 3-allyloxyethyl (meth) acrylate,
-Allyloxy-2-hydroxypropyl (meth) acrylate, N, N-diallyl (meth) acrylamide,
Cinnamyl (meth) acrylate, crotonyl (meth)
Acrylate, methacryl (meth) acrylate and the like can be mentioned. Of these, allyl (meth) acrylate is particularly preferred.

Specific examples of the compound having an unsaturated group represented by the general formula (IXc) include vinyl (meth) acrylate, vinyl crotonate, 1-propenyl (meth) acrylate, 1-chlorovinyl (meth) acrylate, 2
-Phenyl vinyl (meth) acrylate, vinyl (meth) acrylamide and the like. Of these, vinyl (meth) acrylate is particularly preferred.

By copolymerizing these monomers with an unsaturated carboxylic acid, preferably acrylic acid or methacrylic acid, a copolymer having the unsaturated group is obtained. As the monomer to be copolymerized, another monomer may be copolymerized in addition to the unsaturated carboxylic acid, and examples thereof include alkyl acrylate, alkyl methacrylate, acrylonitrile, and styrene. The proportion of the compound having the structure of the general formulas (IXb) and (IXc) to be copolymerized with respect to the total components of the polymer is preferably 10 to 90 mol%, more preferably 30 to 80 mol%.
Mol%. If it is less than this range, the sensitivity and printing durability are poor, and if it is too large, the image reproducibility deteriorates.

The compounding ratio of such a polymer binder is from 0 to 90% by weight, especially from 20 to 90% by weight, based on the total solid content of the photosensitive layer.
It is preferably 80% by weight, particularly preferably 30 to 70% by weight.

In order to form a photosensitive layer according to the present invention using the above-mentioned ethylenic compound, photopolymerization initiator and polymer binder, a photopolymerizable composition obtained by mixing these materials is used without solvent. To form a photosensitive layer, or by dissolving in a suitable solvent and applying as a solution to the hydrophilic support, followed by drying to form a photosensitive layer. When using a solvent,
Examples of the solvent include methyl ethyl ketone, cyclohexanone, butyl acetate, amyl acetate, ethyl propionate, toluene, xylene, monochlorobenzene, carbon tetrachloride, trichloroethylene, trichloroethane, dimethylformamide, methyl cellosolve, ethyl cellosolve, tetrahydrofuran, benzoquinone, and propylene glycol monomethyl. Ether, N-methylpyrrolidone, and the like can be used, and these can be used alone or in combination of two or more.

The photopolymerizable composition for forming the photosensitive layer may further contain, if necessary, other additives such as hydroquinone, p-methoxyphenol, 2,6-di-t-butyl-p- Thermal polymerization inhibitors such as cresol, coloring agents composed of organic or inorganic dyes and pigments, dioctyl phthalate, didodecyl phthalate, plasticizers such as tricresyl phosphate, sensitivity characteristics improvers such as tertiary amines and thiols,
Other additives such as a dye precursor may be added.

In this case, the preferable compounding amount of these various additives is such that the thermal polymerization inhibitor 2 based on the total solid content of the photosensitive layer.
% By weight, colorants such as dyes and pigments, 40% by weight or less, plasticizers, 10% by weight or less, sensitivity characteristic improvers, 20% by weight or less,
The content of the dye precursor is 30% by weight or less.

As a method for applying the photopolymerizable composition to the hydrophilic support, known methods such as dip coating, coating rod, spinner coating, splat coating, and roll coating can be employed. The drying temperature after application is usually about 50 to 150 ° C. for about 0.5 to 10 minutes.

The photosensitive layer formed as described above is
It has no tackiness at room temperature (25 ° C.) and is treated as a one-layer type photosensitive lithographic printing plate having only a photosensitive layer coated on a hydrophilic support without providing a protective layer on the photosensitive layer. It is preferable that it can be.

However, on the photosensitive layer, the purpose of preventing the polymerization inhibition action by oxygen or the pretreatment for peeling off the unexposed portion of the photosensitive layer with a penetrant and physical stimulus is used. A cover sheet can be provided by lamination or coating for the purpose of peeling and removing the exposed portion.

Among the cover sheets, examples of the coating type oxygen blocking layer include water-soluble materials such as polyvinyl alcohol, polyvinylpyrrolidone, gelatin, polyethylene oxide, cellulose, water-soluble modified nylon, polyacrylic acid, polyacrylonitrile, and starch. Polymers, especially those made of polyvinyl alcohol, are excellent. Since the oxygen blocking effect appears when the coating film thickness is 0.1 μm or more, it is usually 0.2 to 10 μm, preferably 0.5 to 5 μm.
m, more preferably 0.5 to 4 μm. The thin film is peeled and removed together with the unexposed portion of the photosensitive layer when the unexposed portion of the photosensitive layer is peeled and removed by physical stimulation.

On the other hand, by peeling off the cover sheet, the adhesiveness between the cover sheet and the photosensitive layer is utilized.
As a cover sheet having a function of peeling and removing only the unexposed portion of the photosensitive layer from the support, those coated with a thick film to withstand the physical force applied at the time of peeling the coating type oxygen barrier layer, Specifically, a film having a thickness of 1 to 100 μm, preferably 2 to 50 μm, more preferably 3 to 30 μm is preferable.

When the cover sheet is provided by lamination, the cover sheet is laminated on the photosensitive layer under such a temperature condition that the photosensitive layer exhibits tackiness, and the cover sheet is separated from the photosensitive layer at room temperature. Some peel off.

In this case, as a material of the cover sheet,
Polyesters such as polyethylene terephthalate, polypropylene, polyolefins such as polyethylene, cellophane, celluloid, various plastic sheets such as polyvinyl alcohol, paper, cloth, wood board, aluminum, metal plates such as copper and the like can be mentioned. Is usually 5
It is 300 μm, preferably 5 to 150 μm, more preferably 10 to 100 μm.

Of these, a transparent cover sheet can be used after laminating the photosensitive layer before or after image exposure, while an opaque cover sheet can be laminated after image exposure. It is limited to the method of doing.

In general, the cover sheet for lamination preferably has an appropriate oxygen blocking effect.

Further, when the cover sheet is provided on the photosensitive layer by lamination, an adhesive layer for enhancing the adhesiveness between the cover sheet and the photosensitive layer is applied on the photosensitive layer or the cover sheet in advance, and then the laminate is laminated. You can also. In this case, it is possible to perform lamination without using the adhesiveness of the photosensitive layer, and therefore, by lowering the lamination temperature.
In this case, it is preferable to provide the adhesive layer on the photosensitive layer, because the adhesive layer material enters the unevenness on the surface of the photosensitive layer and the anchor effect is generated, so that the unexposed photosensitive layer can be effectively peeled off.

Examples of the material used for forming the adhesive layer include:
Examples include thermosetting urethane-based adhesives, epoxy-based adhesives, emulsion-type adhesives having a low softening point such as polyvinyl acetate, and uncured room-temperature adhesives. Is usually 0.1 to 100 μm, preferably 0.3 to 50 μm, more preferably 0.5 to 30 μm.
It is formed to a thickness of μm.

The above-mentioned coating type cover sheet and laminate type cover sheet may be used in combination in order to combine their functions and features.

When the unexposed portion of the photosensitive layer is peeled off by the cover sheet, only a part of the unexposed portion of the photosensitive layer is peeled off and the photosensitive layer is removed from the support so that the remaining portion remains on the support. Is preferably removed. As a result, the remaining photosensitive layer has an effect of protecting the hydrophilic surface of the support, and it is possible to prevent adhesion of dirt due to contact with a transport roller or a finger during transport of the sample. In addition, since the remaining film of the photosensitive layer left on the support is thin, oxygen can easily pass therethrough, and the photosensitivity of the remaining film is significantly reduced. This also has the effect of making it possible.

Next, a method of making a permeation-developed photosensitive lithographic printing plate of the present invention will be described.

The photosensitive lithographic printing plate of the present invention can be obtained by a method comprising: bringing a silver salt mask film for printing plate making into close contact with a photosensitive layer, and exposing the photosensitive lithographic printing plate through the mask film;
Alternatively, without using a mask film, image exposure is performed by a method of scanning and exposing a light beam spot obtained by condensing a light beam from a light source, and the exposed portion of the photosensitive layer is light-cured.

The exposure light source is not particularly restricted but includes, for example, carbon arc, high pressure mercury lamp, xenon lamp,
A metal halide lamp, a fluorescent lamp, a tungsten lamp, a halogen lamp, a helium cadmium laser, an argon ion laser, a YAG laser, a helium neon laser, a visible to near-infrared semiconductor laser, and the like can be particularly preferably used.

Next, a penetrant is applied onto the image-exposed photosensitive lithographic printing plate, and the penetrant is penetrated into the unexposed photosensitive layer, so that the adhesive property between the unexposed photosensitive layer and the hydrophilic support is adjusted. And the unexposed photosensitive layer is removed by applying a physical stimulus such as cloth, cotton, sponge, brush, spray or the like.

The penetrable photosensitive lithographic printing plate of the present invention has a gum support having a peel strength of not more than 500 g / cm on the hydrophilic support, preferably having a peel strength of 0.5 to 200 g / cm between the unexposed photosensitive layer and the support. As soon as the penetrant penetrates the photosensitive layer and reaches the interface between the photosensitive layer and the hydrophilic support, the unexposed photosensitive layer is short-circuited from the hydrophilic support. A state of adhesion with the support is reached which is so low that it can be easily removed in time. Therefore, if there is a small amount of penetrant solution that allows the penetrant to sufficiently penetrate into the photosensitive layer, the above-described development processing can be performed.

On the other hand, the conventional photosensitive lithographic printing plate for alkali developing treatment has a relatively high adhesiveness between the unexposed photosensitive layer and the support, and has a peel strength of 200 g of gum tape.
/ Cm, it is necessary to swell and dissolve the photosensitive layer with a large amount of alkali developing solution and to dissolve it in a large amount of alkali developing solution without utilizing the change in the adhesion between the photosensitive layer and the support. . For this reason, in the conventional alkali developing treatment, a large amount of an alkali developing solution and a long swelling, dissolving, and eluting time are required.

The penetrating agent used in the present invention has a function of permeating the unexposed photosensitive layer according to the present invention to reduce the adhesiveness between the unexposed photosensitive layer and the support. Examples of the penetrant exhibiting such a function include an aqueous solution or an organic solution containing a surfactant, an organic solvent, an alkali agent, and the like.

[0153] Surfactants suitable as penetrants include:
Nonionic surfactants such as polyoxyethylene alkylene ethers, polyoxyethylene alkyl aryl ethers, polyoxyethylene alkyl esters, sorbitan alkyl esters, monoglyceride alkyl esters; alkyl benzene sulfonates, alkyl naphthalene sulfonates, Anionic surfactants such as alkyl sulfates, alkyl sulfonates and sulfosuccinate salts; and amphoteric surfactants such as alkyl betaines and amino acids.

Suitable alkaline agents include sodium silicate, potassium silicate, sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium tertiary phosphate, dibasic sodium phosphate, sodium carbonate, potassium carbonate, and bicarbonate. Inorganic alkaline agents such as sodium, and organic amine compounds such as trimethylamine, diethylamine, isopropylamine, n-butylamine, monoethanolamine, diethanolamine, and triethanolamine, and the like.Examples of the organic solvent include isopropyl alcohol, Examples include benzyl alcohol, ethyl cellosolve, butyl cellosolve, phenyl cellosolve, propylene glycol, diacetone alcohol and the like.

The above-mentioned surfactants, organic solvents, and alkalis can be used alone or in combination of two or more. However, in recent years, there has been an increase in awareness of disposal of alkalis, and in view of odor and working environment. Therefore, a penetrant using a surfactant is preferable.

Preferred penetrants are surfactants: 0.05 to 70% by weight, especially 0.1 to 40%.
% By weight Organic solvent: 0.05 to 70% by weight, especially 0.1 to 40% by weight Alkaline agent: 0.05 to 10% by weight, especially 0.1 to 5% by weight aqueous solution containing one or more kinds Or an organic solution.

The development processing of the permeation-developed photosensitive lithographic printing plate of the present invention is carried out specifically by using a cloth, cotton,
Using a sponge or the like, the photosensitive layer after image exposure is wiped off, thereby penetrating the photosensitive layer penetrant to significantly reduce the adhesiveness of the unexposed portion of the photosensitive layer to the support, It can be carried out by applying a stimulus to peel off and remove the unexposed photosensitive layer.

The photosensitive lithographic printing plate on which an image has been formed by the above-mentioned penetration development can be used as it is for printing. However, in order to remove a penetration agent remaining on the photosensitive layer, cloth, cotton,
It is preferable to wipe it off using a sponge or the like, or to perform a water washing treatment.

[0159] Further, other plate making methods include the purpose of significantly lowering the photosensitivity of the unexposed portions of the exposed photosensitive lithographic printing plate, making the handling environment of the exposed photosensitive lithographic printing plate a bright room, and the purpose of penetration development. In order to reduce the unexposed photosensitive layer to be removed from the support and shorten the development time, most of the unexposed photosensitive layer of the image-exposed photosensitive lithographic plate is peeled off before performing the penetration development. You can also.

In this case, as a method of peeling and removing the unexposed portion of the photosensitive layer, a cover sheet as described above is provided, and by peeling the cover sheet, only the unexposed portion of the photosensitive layer is placed on the cover sheet side. A method of peeling and transferring and removing is preferable. At this time, since the unexposed portion of the photosensitive layer is completely removed from the hydrophilic layer of the support, 0.1 to 50% by weight based on the total solid content of the unexposed portion of the photosensitive layer remains on the support side. It is preferable to peel off and remove it.

The cover sheet may be peeled at room temperature. However, if necessary, the unexposed portion can be easily transferred by peeling the cover sheet at a temperature of 30 to 120 ° C. .

[0162]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples unless it exceeds the gist thereof. In the following, “%” indicates “% by weight” unless otherwise specified.

The following examples and comparative examples used:
The hydrophilic support, the ethylenic compound and the polymer binder are as follows.

Hydrophilic support-1 An aluminum plate having a thickness of 0.2 mm was degreased with 3% sodium hydroxide, and was degreased in a 18.0 g / L nitric acid bath at 25 ° C and 80 ° C.
Electrolytic etching was performed at a current density of A / dm ² for 15 seconds, followed by desmutting with a 1% aqueous sodium hydroxide solution at 50 ° C. for 5 seconds, and then neutralizing with a 10% aqueous nitric acid solution at 25 ° C. for 5 seconds. After washing in a 30% sulfuric acid bath, 30 ° C, 10A / d
Anodizing was performed for 16 seconds under the conditions of m ² , washed with water, and dried to obtain an aluminum plate for a lithographic printing plate (“support-1”). The formed anodized film is 2.1 g / m ² .

Hydrophilic support-2 Support-1 was further subjected to a hydrophilization treatment at 85 ° C. for 30 seconds using a 1% aqueous sodium orthosilicate solution, washed with water and dried to obtain an aluminum plate for a lithographic printing plate (“Support”). -2 ").

Hydrophilic support-3 An aluminum plate for a lithographic printing plate ("Support-3") was obtained in the same manner as in the production of Support-1, except that phosphoric acid was used instead of sulfuric acid. The formed anodized film is 1.8 g / m ² .

Hydrophilic support-4 Water developing type negative type lithographic printing plate manufactured by AGF: HYDRO
The PRINT photosensitive layer was removed by washing with water to obtain a polyethylene terephthalate support for lithographic printing plates (“Support-4”). This polyethylene terephthalate support is obtained by forming a hydrophilic polymer layer having a thickness of several μm on a surface-roughened polyethylene terephthalate having a thickness of 180 μm.

Ethylenic compound-1 "PM-2" manufactured by Nippon Kayaku Co., Ltd. (structural formula is as follows) Ethylenic compound-2 "UA-306H" manufactured by Shin-Nakamura Chemical Co., Ltd. (structure The formula is as follows.) Ethylenic compound-3 "ABPE-4" manufactured by Shin-Nakamura Chemical Co., Ltd. (the structural formula is as follows) Ethylenic compound-4 Ethylenic compound of the following structural formula

[0169]

Embedded image

Polymer binder-1 Methyl methacrylate / isobutyl methacrylate / isobutyl acrylate / methacrylic acid = 35/20/1
0/35 mol% (charge ratio) of copolymer (Mw 70,000) polymer binder- 3-allyloxy-2-hydroxy in a 3 L four-necked flask equipped with a stir bar with two blades, reflux cooling, and a nitrogen tube 80 g of propyl methacrylate, 20 g of methacrylic acid and 1.6 L of ethanol as a reaction solvent were added, and the mixture was heated and stirred in a 90 ° C. oil bath. 1.6 g of azobisisobutyronitrile dissolved in 400 mL of ethanol was added to this solution. After heating and stirring for 3 hours, the nitrogen tube was removed, 0.04 g of p-methoxyphenol and 400 mL of propylene glycol monomethyl ether acetate were added, the bath temperature was raised to 100 ° C, and heating and stirring were continued for 1 hour. Finally, ethanol was distilled off to remove ethylenic polymer binder-2 (M
w, 300,000).

Polymer binder—3 g of 4-necked flask equipped with a stir bar equipped with three blades, reflux cooling, and a nitrogen tube were charged with 107 g of allyl methacrylate, 13 g of methacrylic acid, and 1.6 L of ethanol as a reaction solvent. And heated and stirred in an oil bath. 1.6 g of azobisisobutyronitrile dissolved in 400 mL of ethanol was added to this solution. After heating and stirring for 3 hours, the nitrogen tube was removed, and 0.04 g of p-methoxyphenol and 400 m of propylene glycol monomethyl ether acetate were removed.
L was added, the bath temperature was raised to 100 ° C., and the heating and stirring were continued for 1 hour. Finally, ethanol was distilled off to obtain a 20% solution of ethylenic polymer binder-3 (Mw 180,000).

Polymer binder-4 200 parts by weight of the above polymer binder-1, 75 parts by weight of the following alicyclic epoxy-containing unsaturated compound, 2.5 parts by weight of p-methoxyphenol, 8 parts by weight of tetrabutylammonium chloride , 800 parts by weight of propylene glycol monomethyl ether acetate were added to a reaction vessel,
Stirring reaction in air at 24 ° C. for 24 hours, unsaturated groups are present in 60% of the methacrylic acid component of the ethylenic polymer binder-4 (Mw 75,000, acid value 60, polymer binder-1). Reacted) to give a 25% solution.

[0173]

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Examples 1 to 6 and Comparative Example 1 A coating solution of the photopolymerizable composition having the following formulation-1 was prepared, and the coating solution was coated with a bar coater so as to have a dry film thickness of 2 g / m ^2. The composition was applied to the support shown in No. 1 and dried. Further, an aqueous solution of polyvinyl alcohol was applied and dried using a bar coater to a thickness of 3 μm at a dry film weight of 3 g / m ² to prepare a photosensitive lithographic printing plate. The following items were evaluated for the obtained photosensitive lithographic printing plate, and the results are shown in Table 1.

Formulation of coating liquid for photopolymerizable composition-1 (parts by weight) Ethylene monomer shown in Table 1: 55 Polymer binder ^{* 1)} shown in Table 1: 45 The following structural formula (A-1) Compound: 2.0 Titanocene compound of the following structural formula (B-1): 10 2-mercaptobenzothiazole: 5.0 N, N-dimethylbenzoic acid ethyl ester: 10 Copper phthalocyanine pigment: 3.0 Cyclohexanone: 1090 * 1 ) The solid component of the polymer binder solution and the solvent in the polymer binder solution are used as a coating solvent.

[0176]

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Evaluation Items <Peeling Strength> The peeling strength of the gum tape of the unexposed photosensitive layer, the exposed (photocured) photosensitive layer, and the hydrophilic support was measured according to the above-mentioned measuring method (shown in FIG. 1). The peel strength of the gum tape of the support is the peel strength when peeling the gum tape adhered to the support on which the photosensitive layer is not formed.

<Sensitivity> A diffractive spectral irradiation apparatus (“RM-2 manufactured by Narumi”) for irradiating the photosensitive lithographic printing plate with light so that the irradiation light wavelength decreases in the horizontal direction and the light intensity decreases logarithmically in the vertical direction.
3)), and a gum tape ("SLIONTA" manufactured by SLIONTEC) on the polyvinyl alcohol layer.
PE "), and then the gum tape was peeled from the sample and most of the unexposed portions of the photosensitive layer of the sample were peeled off from the support. Subsequently, the surface of the image of the photosensitive layer of the sample was exposed to a penetrant (sodium alkylnaphthalenesulfonate type surfactant (“Perex N13” manufactured by Kao Corporation).
L ")) was wiped off with a waste cloth (old cloth) impregnated with a 30% by weight aqueous solution of the photosensitive layer to remove a residual film on an unexposed portion of the photosensitive layer, thereby forming a photocured image.

The sample was mounted on a plate cylinder on a printing machine (lithographic printing machine “Dia F-2” manufactured by Mitsubishi Heavy Industries, Ltd.), and printing was performed.
The light energy required for photocuring with a light beam of 488 nm was determined from the height of the printed image on the 100th printed material obtained in the vertical direction. F in the table indicates that an unexposed portion was not removed and no image was formed.

<Printing durability> The photosensitive lithographic printing plate was air-cooled with an argon laser (“PI-” manufactured by Dainippon Screen Co., Ltd.).
R)), and scanning exposure was performed at an exposure amount of 100 μJ / cm ² , and penetration development was performed in the same manner as in the evaluation of sensitivity. Printing was performed using the obtained printing plate, and the number of printed sheets until the image area (120 lines, 4% small point) jumped was indicated as printing durability. F in the table indicates that it was not evaluated.

<Image Reproducibility> UGR was applied to the photosensitive lithographic printing plate.
After the A-plate control wedge was exposed in close contact with a high-pressure mercury lamp, penetration development was performed in the same manner as in the sensitivity evaluation. The image reproducibility was evaluated based on the remaining state of the positive fine line image of the circular patch on the printed matter (the thinner the finer the line, the better the image reproducibility). F in the table indicates that it was not evaluated.

[0182]

[Table 1]

Examples 7 to 9 and Comparative Example 2 The same operation as in Examples 1 to 6 and Comparative Example 1 was carried out except that the following composition 2 was used as the coating liquid for the photopolymerizable composition. , Sensitivity, image reproducibility and peel strength were evaluated, and the results are shown in Table 2.

Photopolymerizable composition coating liquid formulation-2 (parts by weight) Ethylenic monomer shown in Table 2: 55 Polymer binder shown in Table 2: 45 Compound of the following structural formula (A-2): 2 2.0 2,2'-bis (o-chlorophenyl) -4,4 ', 5,5'-tetra (o, p-dichlorophenyl) biimidazole: 10 2-mercaptobenzothiazole: 5.0 N, N- Dimethyl benzoic acid ethyl ester: 10 Copper phthalocyanine pigment: 3.0 Cyclohexanone: 1090

[0185]

Embedded image

[0186]

[Table 2]

Example 10 A photosensitive lithographic printing plate was prepared in the same manner as in Example 1 except that the cover sheet layer of polyvinyl alcohol was not provided, and this photosensitive lithographic printing plate was treated with the photosensitive surface side of the printing plate. When put in a transparent container and subjected to image exposure in the same manner as in Example 1 in a state where the inside of the container was depressurized, a high-quality printed image was obtained and the sensitivity was 75 μJ / c.
m ² .

[0188]

As described above in detail, according to the present invention, it is possible to provide a permeation-developed photosensitive lithographic printing plate excellent in printing durability, sensitivity and image reproducibility.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a method for measuring a peel strength of a gum tape.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Support 1A Photosensitive layer 1B Polyvinyl alcohol layer 2 Fixed base 3 Gum tape

Claims (7)

[Claims] A penetrating development comprising a support having been subjected to a hydrophilization treatment and a lipophilic photosensitive layer containing a compound having at least one addition-polymerizable ethylenic double bond and a photopolymerization initiation system provided on a support subjected to a hydrophilic treatment. A photosensitive lithographic printing plate, wherein the peel strength of the gum tape from the support determined by a method of measuring the peel strength with a gum tape is 500 g / cm or less. 2. The penetrative photosensitizer according to claim 1, wherein the peel strength of the photosensitive layer from the support before exposure, determined by a peel strength measuring method using a gum tape, is 0.5 to 200 g / cm. Sexographic printing plate. 3. The lithographic photosensitive lithographic printing plate according to claim 1, wherein the peel strength of the photosensitive layer from the support after exposure determined by the peel strength measuring method using a gum tape is greater than 200 g / cm. Print version. 4. The image-wise exposing of the photosensitive layer of the lithographic printing plate according to any one of claims 1 to 3 by imagewise exposing the photosensitive layer with ultraviolet to near-infrared light. A plate-making method for forming a photo-cured photosensitive image by removing an unexposed portion of the photosensitive layer from the support after photo-curing, wherein the plate is penetrated into the unexposed photosensitive layer to support the photosensitive layer. A penetrating agent that reduces the adhesiveness to the body surface is penetrated into the photosensitive layer after image exposure, and a physical stimulus is applied to the photosensitive layer. A method of making a permeation-developed photosensitive lithographic printing plate comprising removing a portion from a support. 5. The photosensitive layer of the lithographic printing plate for permeation development according to claim 1, wherein the photosensitive layer is imagewise exposed to light of ultraviolet to near-infrared to form an imagewise image. After photo-curing, a plate-making method for forming a photo-cured photosensitive image by removing an unexposed portion of the photosensitive layer from the support, wherein the permeation-developed photosensitive lithographic printing plate before or after image exposure. Providing a cover sheet on the photosensitive layer of the permeation-developed photosensitive lithographic printing plate, when peeling the cover sheet from the photosensitive layer after image exposure, utilizing the adhesiveness of the cover sheet, the unexposed portion Wherein the unexposed portions are removed from the support by transferring the lithographic printing plate to the cover sheet side. 6. The image forming apparatus according to claim 5, wherein the cover sheet is peeled off from the photosensitive layer after the image exposure to remove a part of the unexposed portion from the support, and then penetrate into the unexposed photosensitive layer. Then, a penetrating agent that reduces the adhesiveness between the photosensitive layer and the surface of the support is penetrated into the photosensitive layer after image exposure, and a physical stimulus is applied. A method for making a permeation-developed photosensitive lithographic printing plate, comprising removing the remaining unexposed portion of the photosensitive layer from the support. 7. The unexposed portion according to claim 6, wherein the cover sheet is peeled off from the photosensitive layer after image exposure so that 0.1 to 50% by weight of the unexposed portion remains on the support. A method for making a permeation-developed photosensitive lithographic printing plate, characterized by removing lithographic printing plates.