JPH02160240A - Photosensitive planographic printing plate of both positive and negative uses and production of planographic printing plate by using this plate - Google Patents

Abstract

PURPOSE:To provide the plate surface which is resistant to staining and to improve printing resistance by providing a photosensitive layer formed of a photosensitive compsn. which contains an orthoquinone diazide compd., alkali soluble resin and org. dye and contains at least one kind selected from oxazole, isoxazol, etc., on a base. CONSTITUTION:The photosensitive layer formed of the photosensitive compsn. which contains the orthoquinone diazide compd., the alkali soluble resin and the org. dye and contains at least one kind selected from a group consisting of the oxazol, isoxazol, pyrazole, triazole and the deriv. thereof is provided on the base. The content of the orthoquinone diazide compd. is preferably 5 to 60wt.% of the total solid content of the photosensitive compsn. and the content of the alkali soluble resin is preferably 30 to 90wt.% of the total solid content of the photosensitive compsn. The org. dye is preferably incorporated into the compsn. at 0.01 to 5wt.% of the total solid content of the photosensitive compsn. The surface resistant to staining and the excellent printing resistance are obtd. in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a photosensitive lithographic printing plate for both positive and negative types and a method for producing a lithographic printing plate using the same.

[Prior Art 1] In the process of producing a printing plate for printing, it is widely practiced to use two types of photosensitive planographic printing plates, positive type and negative type. However, since the materials forming the photoreceptor are different between the positive-working photosensitive lithographic printing plate and the negative-working photosensitive lithographic printing plate, different developers must be used in the development processing of the two. Therefore, when both a positive type and a negative type are used, it is necessary to replace the developer in the developing device and the associated ttIF! Due to cleaning in step 4, a significant decrease in work efficiency occurs.

A technique is known that allows one type of photosensitive lithographic printing plate to be used for both positive and negative types to solve the above problem. Examples of such technology include, for example, the
A method of forming a negative image by a specific method from a photosensitive lithographic printing plate using a positive photosensitive composition containing orthoquinone diazide as disclosed in Japanese Patent No. 6-14970 is known.

That is, in this method, a photosensitive lithographic printing plate that can be image-wise exposed and then developed to produce a 1:1 positive image is image-wise exposed in the same manner, followed by heat treatment, full-surface exposure, and further. A negative image is obtained by subsequent development with a positive developer.

However, the above-mentioned photosensitive lithographic printing plates that can be used for both positive and negative types lack clarity in distinguishing between exposed and unexposed areas during or after image exposure, so-called exposed visible image quality, and furthermore, such photosensitivity The lithographic printing plate obtained from the lithographic printing plate has the drawback that the plate surface is easily stained during printing, and the printing durability is poor even with the recent increase in the number of print runs in this industry.

[Object of the Invention] An object of the present invention is to provide a photosensitive lithographic printing plate that can be used for both positive and negative types and has improved exposure and visible image properties in the processing process for obtaining negative images.

Another object of the present invention is to provide a photosensitive lithographic printing plate that can be used for both positive and negative types, making it possible to obtain a lithographic printing plate whose plate surface is resistant to staining and whose printing durability is improved.

Another object of the present invention is to provide a method for producing a negative-working lithographic printing plate from a photosensitive lithographic printing plate that normally exhibits a positive action, which provides improved exposure visibility and improved resistance to staining of the plate surface. An object of the present invention is to provide a method for producing a lithographic printing plate that determines printability.

[Structure of the Invention] The above-mentioned object of the present invention is to provide an orthoquinone diazide compound containing an alkali-soluble resin and an organic dye, and selected from the group consisting of oxazole, isoquaternary diazole, pyrazole, triazole, and a conductor thereof. A photosensitive lithographic printing plate for both positive and negative types, characterized in that it has a photosensitive layer formed on a support, made of a photosensitive composition containing at least one type of photosensitive composition, and the photosensitive lithographic printing plate. This has been achieved by providing a method for producing a 119th lithographic plate, which is characterized in that after image exposure, heat treatment is performed, and then the entire photosensitive layer is exposed and then developed with an aqueous alkaline developer.

The present invention will be described in detail below.

The orthoquinonediazide compound used in the present invention is a compound having at least one orthoquinonediazide group, preferably an orthobenzoquinonediazide group or an orthonaphthoquinonediazide group, and is a compound having various known structures, such as J, 1< Written by osar [Light -
3cnsitive system cmsJ (J ohn
Wiley & 5ons, Inc., 196
may include compounds described in detail on pages 339 to 353 (published in 2010). Particularly suitable are esters or amides of various hydroxyl compounds or amino compounds with 1,2-quinonediazide-4-sulfonic acid or 1,2-quinonediazide-5-sulfonic acid, including 1,2-quinonediazide-4-sulfonic acid. The Nisder compound of aY is particularly preferred. Preferred hydroxyl compounds for τ include condensation resins of phenols and carbonyl group-containing compounds, particularly resins obtained by condensation in the presence of an acidic catalyst. Examples of the phenols include phenol, resorcinol, cresol, pyrogallol, etc., and examples of the carbonyl group-containing compound include aldehydes such as formaldehyde and benzaldehyde, and ketones such as acetone.

Particularly preferred are phenol-bon, luminaldehyde resin, cresol-formaldehyde resin, pyrogallol-acetone resin, and resorcinol-benzaldehyde resin.

Typical specific examples of the orthoquinone diazide compound used in the present invention include benzoquinone-(1,2)-diazide sulfonic acid or naphthoquinone-(1,2)-diazide sulfonic acid and phenol/formaldehyde resin or cresol/formaldehyde resin. ester with,
Sulfonic acid ester of naphthoquinone-(1,2)-diazide sulfonic acid and pyrogallol acetone resin, naphthoquinone-(1,2)-diazide-(2) described in U.S. Pat. - Condensate of 4-sulfonic acid and resorcin benzaldehyde resin,
Ester compounds of naphthoquinone-(1,2)-diazide-(2)-4-sulfonic acid and resorcinol-pyrogallol-acetone copolycondensates or pyro-acetone copolycondensates, and other useful orthoquinonediazide compounds Examples include esters of a polyester having a hydroxyl group at the terminal and orthonaphthoquinonediazide sulfonic acid, as described in Toku 1FiI No. 117503/1982, and esters of orthonaphthoquinonediazide sulfonic acid as described in JP-A-50-113305. Esters of p-hydroxystyrene homopolymers or copolymers with other heptamers that can be copolymerized with p-hydroxystyrene and ortho-naphthoquinonediazide sulfonic acid, esters of trihydro-4-nidibenzophenone and orthoquinonediazide sulfonic acid, etc. Can be mentioned.

In the present invention, the nail containing these orthoquinone diazide compounds preferably ranges from 5 to 60% by weight, particularly preferably from 10 to 50% by weight, based on the total solid content of the photosensitive composition.

Oxazole, isoxazole used in the present invention,
At least one compound selected from the group consisting of pyrazoles, triazoles, and derivatives thereof (hereinafter referred to as "compounds of the present invention") has the following formulas (1) to
Compounds represented by any of (Vl) (including isomers if they have isomers) are preferred.

General formula (1) General formula (II) General formula (III) General formula (IV) General formula (V) General formula (Vl) General formula (■) (wherein, R1 and R2 are a hydrogen atom and an alkyl group, respectively) , represents an amino group or a 21-1] group.) R1 and R2
Examples of the alkyl group represented by each of these include methyl group, ethyl group, propyl group, isopropyl group, and phenyl group.

Examples of compounds of the invention include pendioquinazole, 2
-Methylbenzoxazole, isomexazole, 5-
MethylisoAquinazole, 3.5-dimethylisoxazole, 3-amino-5methylisoxazole, 2.
4-diphenyloxazole, 2,5-diphenyloxazole, pyrazole, 3-methylpyrazole, 4-methylpyrazole, 3-aminopyrazole, indazole, 5-aminoindazole, 6-nitroindazole,
1,2,4-triazole, 3-nitro-1,2,4-
Examples thereof include triazole, 3-amino-1°2.4-triazole, 1.2.3-benzotriazole, 5-methyl-1-day-benzo I. riazole, and 5-nitrobenzotriazole. These compounds are contained in the photosensitive composition in an amount of 0.2 to 10% by weight, preferably 0.5 to 4 mω%, based on the total solid content.

An alkali-soluble resin is used in the photosensitive planographic printing plate of the present invention. Such a resin is preferably a compound having an alkali-soluble group such as a phenolic hydroxyl group, a carboxyl group, a sulfone MW, or a phosphorus MM. The one obtained by condensation with is preferable. Examples of the phenols include phenol, cresol, and p-substituted phenol. Examples of the aldehydes include acetaldehyde and formaldehyde, with formaldehyde being preferred. Acetone is preferred as the ketone.

Preferred alkali-soluble resins include, for example, phenol-formaldehyde resin, cresol-formaldehyde resin, phenol-cresol-formaldehyde copolycondensate resin as described in JP-A-55-57841@, and JP-A-55-57841@. Copolycondensate resins of p-substituted phenol and phenol or cresol and formaldehyde, as described in Japanese Patent No. 127553, resorcinol-benzaldehyde resins, biloga 0-rubenzaldehyde resins, and other polyhydric phenols and benzaldehyde. Examples thereof include condensates, copolycondensates of polyhydric phenol and acetone such as bigallol-resorcinol-Uton resin, and xylenol-formaldehyde resins. The content m of these alkali-soluble resins is preferably 30 to 90% by weight based on the total solid content of the photosensitive composition, particularly 5% by weight.
0 to 85% by weight is preferred.

Moreover, the photosensitive composition according to the present invention can contain an organic dye. Preferred organic dyes include, for example, Victoria Pure Blue BOH [Hodogaya Chemical Co., Ltd.] (CI 42
595), Oil Blue 9603 [Orient Chemical Industry Co., Ltd. 1, Patent Pure Blue [Sumitomo Mikuni Chemical Co., Ltd.] (
CI 42045), Crystal Violet (C
I 42555), Brilliant Green (CI 42555), Brilliant Green (CI 42555)
42040), ethyl violet, methyl violet (Cl 42535), methyl green (C
, 145285), Engineering IJ SuO? /nB (CI
45430), Pesic Tsuksin (C142510)
, Malachite Green (CI 42000), Oi/LzL/7F (C160505), lτ Cresol Purple, 0-Damine B (CI 45170)
, auramine (CI 41000), 4-D-diethylaminophenylimino naphthoquinone, triphenylmethane type represented by cyano-p-diethylaminophenylacetanilide, etc., diphenylmethane type, oxazine type, oxatene type, iminodef 1-quinone type, azomethine type and anthraquinone dyes.

The organic dye is preferably used in an amount of 0.01 to 5% by weight, more preferably 0.1 to 3 mm, based on the total solid content of the photosensitive composition.
Contained in % m.

In addition to the materials described above, the photosensitive composition used in the photosensitive lithographic printing plate of the present invention can also contain the following additives, if necessary.

That is, various low-molecular compounds (e.g. phthalates, triphenyl phosphates, maleate esters, etc.) as plasticizers, surfactants (e.g. fluorosurfactants, ethyl cell 0- nonionic activators typified by polyalkylene ethers, etc.), acid anhydrides and the like as sensitizers for positive photosensitive compositions. Furthermore, a compound that generates acid or free tJIM upon exposure to light and interacts with an organic dye such as those described above to change the color tone of the dye may be included as a printout for forming a visible FM image upon exposure to light. can. Examples of compounds that generate acids or free radicals upon exposure to light include 0 described in JP-A No. 50-36209.
-Naphthoquinonediazide-4-sulfonic acid halide, trihalomethyl-2-pyone and trihalomethyl-triazine described in JP-A-53-36223, ortho-naphthoquinonediazide as described in JP-A-55-6244. Ester compounds of 4-sulfonic acid chloride and phenols or anilines having electron-withdrawing substituents, halomethyl-vinyl-oxadiazole compounds and di7zoni-1cum salts described in JP-A-55-77742, etc. can be mentioned. These compounds vary depending on their type, but generally the amount during addition is 0.01 to 20% by weight, preferably 0.0% by weight based on the total solid content of the photosensitive composition.
5 to 10% by weight is suitable.

The photosensitive lithographic printing plate of the present invention can be obtained by dissolving the photosensitive composition described above in a suitable solvent and coating the solution on a support. Examples of solvents used include ethylene glycol, ethylene glycol monomethyl needles, ethylene glycol monomethyl ether acetate, ethylene glycol isopropyl needles, ethylene glycol monobutyl ether, diethylene glycol, diethylene glycol monomethyl needles, diethylene glycol monoethyl ether, propylene glycol, Preferred examples include ethers of polyhydric alcohols such as propylene glycol motsubutyl ether, brobylene glycol monomer, thyl ether acetate, propylene glycol monoethyl ether, propylene glycol heptanoethyl ether acetate, and propylene glycol motsubutyl ether; In addition, ethers such as dioxane, dihydrofuran, and tetrahydrobilane; methyl ethyl ketone, methyl propyl carbon, methyl butyl carbon, methyl amyl carbon, diethyl ketone, diacetic alcohol, cyclopentanone, cyclohexanone, etc. Ketones: methanol, ethanol,
Propatool, Isopropatool, n-butanol, 5
Alcohols such as ec-butanol, tert-butanol, n-pentanol, isopentanol, n-hekylinol, isohexanol: ethyl acetate, propyl acetate, butyl acetate, amyl acetate, hexyl acetate, ethyl propionate, Esters such as butyl propionate can also be used.

Examples of the support used in the photosensitive lithographic printing plate of the present invention include aluminum plates, metal plates such as salivary lead, copper, and iron, paper on which metals are vapor-deposited, and Plus Deck films. Most preferred. Particularly preferred is an aluminum 1Kum board that has been subjected to surface treatments such as graining, anodizing, and, if necessary, sealing.

The coating m of the photosensitive composition on the support varies depending on the use, but is 0.5 to 3.0 m as solid content in the shell.
5 (J/f range is appropriate.

From the photosensitive lithographic printing plate obtained as described above, a positive image can be obtained by developing with a positive developer after image exposure. Further, a negative image can be obtained by performing heat treatment after image exposure, and further exposing the entire surface of the photosensitive layer to light, and then developing with an aqueous alkaline developer.

Image exposure of the photosensitive lithographic printing plate in the present invention includes, for example,
The image-formed translucent film is brought into close contact with a photosensitive lithographic printing plate as an original, and exposed to a fluorescent tube, xenon lamp,
This can be carried out by various commonly used methods, such as using a publicly available light source such as a high-pressure mercury lamp charged with a metal halide or a carbon arc lamp.

Further, in the present invention, the heat treatment following the image exposure is preferably carried out at a temperature in the range of 80 to 200°C, preferably 90 to 160°C, for 1 to 30 minutes, preferably 3 to 15 minutes. If the heating temperature is too low, there will be problems such as the photosensitive layer dissolving in the developer during development, and if the heating temperature is not too high, problems such as the entire surface of the photosensitive layer will be cured. There is.

Such heat treatment is generally carried out by leaving the photosensitive lithographic printing plate in heated air for the above-mentioned period of time after image exposure; It is also possible to do so.

The entire surface exposure performed after the heat treatment can be performed using the same apparatus as the image exposure.

In addition, in the method of the present invention, the following developers can be mentioned as the aqueous alkaline developer used for developing the photosensitive lithographic printing plate. .

However, it is related to the present invention. The developer is an alkaline aqueous solution, and the alkaline agent used is preferably potassium silicate, lithium silicate, sodium silicate, sodium hydroxide, potassium hydroxide, lithium hydroxide, tribasic sodium phosphate, diphosphoric acid. Examples include sodium, tribasic potassium phosphate, dibasic potassium phosphate, thorium carbonate, potassium carbonate, and the like. Among these, a developer containing an alkali silicate such as potassium silicate, lithium silicate, or sodium silicate is preferable because it has good development gradation.
] / [M] = 0.5 ~ 1.5 (here [Si 0
2] and [M] indicate the molar concentration of 3i02 and the molar concentration of total alkali metals, respectively. ) and a developer containing 0.8 to 8% by weight of 5102 is preferably used. Of this alkali silicate composition, especially in molar ratio [Si
02 ] / [M] = 0.5 to 0.75,
A developer containing 0.8 to 4% SiO2 is preferably used because it has a low fJ degree and can easily neutralize the developer waste.
On the other hand, the molar ratio is more than 0.15 and up to 1.3, and S
A developer having an iO2 content of 1 to 8% by weight is preferably used because it has a high buffering power and a high throughput.

In addition, it is preferable that the alkali silicate contains 20 mol% or more of potassium as the alkali metal in the total alkali metals, since the generation of insoluble matter in the reaction liquid is small, and more preferably 90 mol% or more of potassium. Most preferably, the potassium content is 100 mol%.

The tIH value of the developer preferably used in the present invention is 25°C.
is 12 or more, preferably 12.5 to 14.
It is 0.

Furthermore, water-soluble sulfite M salts such as potassium sulfite, potassium sulfite, lithium sulfite, and magnesium sulfite can be added to the current flil solution. The preferred content m of sulfite in the developer is 0.05 to 4 wt M%, more preferably 0.1 to 1 wt M%.

In addition, anionic surfactants such as those described in JP-A-50-51324, amphoteric surfactants A3, and JP-A-59-75255 and JP-A-Sho 6 may be added to the developer.
By containing at least one of the nonionic surfactants as described in JP-A No. 0-111246 and JP-A No. 60-213943, or by including at least one of the nonionic surfactants described in JP-A-55-95946 and JP-A-55-95946, It is preferable to include a Hatake molecular electrolyte as described in Japanese Patent No. 142,528, etc., because it can improve wettability to the photosensitive composition and further improve gradation. The amount of such surfactant added is not particularly limited, but it is preferably 0.003 to 3% by weight, particularly preferably 0.00 to 1% by weight.

Furthermore, the developer used in the present invention can contain an antifoaming agent. Suitable antifoaming agents include organosilane compounds.

Various conventionally known methods can be used to develop the photosensitive lithographic printing plate of the present invention which has been imagewise exposed with the above developer. Specifically, for example, a method of immersing the image-exposed photosensitive lithographic printing plate in a developer, a method of jetting a developer from a number of nozzles onto the photosensitive layer of the photosensitive lithographic printing plate, and a method of ejecting a developer from a number of nozzles; Examples include a method of wiping the photosensitive layer of the photosensitive lithographic printing plate with a sponge moistened with a sponge, and a method of rolling a developer onto the surface of the photosensitive layer of the photosensitive lithographic printing plate. Further, after applying the developer to the photosensitive layer of the photosensitive lithographic printing plate in this manner, the surface of the photosensitive layer may be lightly rubbed with a brush or the like. The developing conditions can be appropriately selected depending on the developing method. - For example, in the development method by immersion, a method of immersing in a developing solution at about 10 to 40° C. for about 10 to 80 seconds is selected.

[Examples] The present invention will be explained below with reference to Examples, but the present invention is not limited thereto.

Example 1 A photosensitive liquid having the following composition was prepared and coated on a grained aluminum plate using a roll coater to reduce the solid content to 1.8.
(After coating to give a coating m of J/l', it was dried to obtain photosensitive lithographic printing plate sample 1.

(Photosensitive liquid composition) ・1~lyhydroxybenzophenone and naphthoquinone (1
, 2) 2.3 parts by weight of ester compound (QD-1) with diazide-4-sulfonic acid chloride, phenol, m-, p-n co-condensation resin of resol and formaldehyde (phenol, -1) ,p-
Molar ratio of mixed cresol is 48:32:20)
0.7 parts by weight・Novolac resin synthesized from paraoctylphenol and formalin 0.9 type assembly・2-trichlordel-
5-(β-Benzofurylvinyl)-1,3,4-oxadiazole 0.05 jlifl 1 part, isoxazole 0.07 weight d part, Victoria Pure Blue BOH 0.07ml 1 part, ethylene glycol monomethyl ether type 8 part - Ethylene glycol heptanoethyl ether 37 parts by weight In the above photosensitive liquid composition, isoxazole or QD-
Photosensitive lithographic printing plate samples 2 to 8 were prepared in the same manner as sample 1 except that 1 was replaced with the compounds shown in Table 1.

Each of Samples 1 to 8 obtained above was cut into two pieces, one of which was prepared by exposing the positive original image to light, and then adding 0.1% of sodium benzenesulfonate to a 4% solution of sodium metasilicate, which contained an organic solvent. The sample was immersed in a developer solution at 27° C. for 20 seconds and developed to obtain a clear positive image. For exposure, the positive original formed on a transparent film was tightly placed on the printing plate, and a 2KW metal halide lamp (Archiwa Electric (Idol Fin 2000 made by Kiki) was used.
The exposure was carried out for 70 seconds at a light intensity of 8.0 mW/(, f) using a light source of Image and step tablet (
Eastman Kodak Company No. 2. am degree difference 0.15
1 after exposure (according to 21 steps of gray scale)
The film was left in an air constant temperature bath maintained at 40° C. for 5 minutes, and after cooling, it was exposed under the same conditions as the image exposure without using the original image. Next, development was performed under the same conditions as those used to obtain the positive image to obtain a clear positive image.

Hereinafter, the positive image obtained by this method will be referred to as a negative-positive image.

The exposure visibility was evaluated for each negative-positive image produced. In addition, each of the obtained lithographic printing plates was used to perform printing under the following printing conditions, and the staining of the plate surface and printing durability were evaluated.

(Printing conditions) Printing machine: Heidel GTO Printing ink: Toyo King New Bright Red (manufactured by Toyo Ink Co., Ltd.) Paper: High quality paper Printing speed: 8000 sheets/hour Evaluation of plate surface stains Humidity 62
% printing room, and the supply of dampening water was cut by 20% at a certain point during printing, and printing was carried out with the number of sheets that could produce stain-free prints.

Further, the printing durability was evaluated based on the number of sheets at the time when the ink stopped adhering to the image area.

Comparative Example 1 Sample 9 was prepared in the same manner as Sample 1 except that isoxazole was removed from the photosensitive liquid composition of Example 1.
Also, from the composition of the photosensitive liquid, Victoria Pure Blue B
Sample 10 was prepared in the same manner as Sample 1 except that OH was removed, and Sample 11 was prepared in the same manner as Trial 1 except that Isoxalur and Victoria Pure Blue BOH were removed from the composition of the photosensitive liquid. Each of these samples 9 to 11 was treated and evaluated in the same manner as Example 1 of actual pus.

For trials 9 and 10, clear positive-positive images and negative-positive images could be obtained.

Regarding sample 11, a clear positive-positive image was obtained, but a stable negative-positive image was not obtained. The evaluation results are shown in Table-1.

Comparative Example 2 Cresol formaldehyde resin and 71-quinone-(1
,2)-diazide-5-sulfonic acid (QD
-3), imidazole was used instead of isoxazole, and sample 12 was prepared in the same manner as sample 1 except that Victoria Pure Blue was removed. Sample 13 was prepared in the same manner as Sample 1 except that -3 was used, and jetanolamine was used instead of isookyrisyl, and QD-3 was used instead of QD-1 in the photosensitive liquid composition of Example 1.
1'3',3' instead of isoox 1 nozole
Sample 14 was prepared in the same manner as Sample 1 except that -trimethyl-6'-nitrospiro[2H-1-benzopyran-2,2'-indoline] was used and Victoria Pure Blue was removed. Example 1 for these samples 12-14, -''1. ':,! ′! Book I QD-2: Pyrogallol acetone resin and naphthoquinone (1,2
)-Ester compound with diazide-4-sulfonic acid D-ride Book 2 QD-3; Cresol formaldehyde resin and naphthoquinone-(
Ester with 1,2)-diazido-5-sulfonic acid *3 Exposure visible image quality evaluation Δ: 8≧O, 17 B: 0.15≦ΔQ<0.17 C: 0.12≦ΔQ<0. 15 [): 0.09≦ΔQ<0.12 E: ΔQ<0.09 where ΔD represents the density difference between the exposed area and the unexposed area.

As is clear from Table 1, samples Nos. 001 to 8 of the present invention containing the compound of the present invention all had excellent exposed visible image properties, and the lithographic printing plates obtained from each sample The plate surface is less stained and has improved printing durability.

[Effects of the Invention] According to the present invention, a positive-working/negative printing plate which has improved exposure visibility through negative processing, has a plate surface that is resistant to stains, and has improved printing durability. A dual-purpose photosensitive lithographic printing plate is provided.

Patent applicant: Konica Corporation (and one other person) Representative: Patent attorney Miyahito Ichinose':”:”, IL・-・yl [,te

Claims (2)

[Claims] (1) A photosensitive composition containing an orthoquinone diazide compound, an alkali-soluble resin, and an organic dye, and containing at least one member selected from the group consisting of oxazole, isoxazole, pyrazole, triazole, and derivatives thereof. A photosensitive lithographic printing plate for both positive and negative types, characterized by having a photosensitive layer on a support. (2) Formed from a photosensitive composition containing an orthoquinone diazide compound, an alkali-soluble resin, and an organic dye, and containing at least one member selected from the group consisting of oxazole, isoxazole, pyrazole, triazole, and derivatives thereof. A lithographic printing plate comprising a photosensitive lithographic printing plate having a photosensitive layer on a support, which is subjected to imagewise exposure and then subjected to heat treatment, and then the entire surface of the photosensitive layer is exposed and then developed with an aqueous alkaline developer. Fabrication method.