JPH0830140B2 - Photosensitive lithographic printing plate - Google Patents

Description

TECHNICAL FIELD The present invention relates to a positive-working photosensitive lithographic printing plate, and more specifically, it contains a positive naphthoquinonediazide compound and is excellent in safelight property and ball-point pen suitability. Type photosensitive lithographic printing plate.

[Background of the Invention and Prior Art] Usually, in a photosensitive layer of a positive type photosensitive lithographic printing plate, an o-quinonediazide compound is used as a photosensitive component, and an alcal-soluble resin is used as a component for enhancing film strength and alkali solubility. It is contained.

When performing so-called "multi-sided printing" in which a plurality of film originals are printed at different positions one after another on a photosensitive lithographic printing plate having a photosensitive layer using such an o-quinonediazide compound, the originals are aligned for alignment between the film originals. Position may be marked on the photosensitive layer. At this time, an oil-based ballpoint pen is usually used as the writing instrument to mark, but when the solvent of the ink of the ballpoint pen is an organic solvent, especially a high-boiling point solvent such as a glycol system, the photosensitive layer of the photosensitive lithographic printing plate is Are eroded and dissolved. When the marked portion is the image portion, if the development processing is performed as it is, the photosensitive layer of the mark trace of the image portion is removed, and this mark trace may be reproduced on the printed matter at the time of printing, which may cause a failure. Therefore, a photosensitive lithographic printing plate having a property of being less likely to be eroded by the ink of the ballpoint pen (hereinafter referred to as "ballpoint pen suitability") is desired.

Further, the photosensitive lithographic printing plate using the o-quinonediazide compound suffers from light fog when the plate making operation is performed under a white fluorescent lamp, and when it is subsequently developed, the photosensitive layer of the image area is eroded. As a result, the film thickness is reduced and the printing durability at the time of printing is often reduced. Therefore, there is a demand for a photosensitive lithographic printing plate having a photosensitive layer with improved resistance to light fog of a white fluorescent lamp (hereinafter referred to as "safelight property").

Further, the developing treatment of the photosensitive lithographic printing plate using the o-quinonediazide compound is usually carried out with a developing solution of an alkaline aqueous solution, but the developing ability of the developing solution is easily changed under various conditions, and fatigue and air oxidation due to a large amount of processing are caused. In some cases, the developing ability is deteriorated due to deterioration due to the above, and the photosensitive layer in the non-image area of the printing plate may not be completely dissolved even if processed. On the other hand, the developing capacity may exceed the specified level due to an excessive amount of replenishment or an increase in bath temperature due to an increase in temperature, and the image portion of the printing plate may be damaged or halftone dots may disappear. For this reason, in particular, the photosensitive lithographic printing plate has a wide development allowance showing the same developability as in the case of processing with a standard developing solution, even if the developing solution has a lower processing capacity or a developing solution having a higher processing capacity than the standard. It is desired to have sex. (Hereinafter, the allowable range of developing ability reduction that gives an adequate development result is defined as "underdevelopment".
That is, the permissible range of the increase in developing ability that can obtain a proper development result is called "over-developing property". With respect to the above problems, JP-A-61-6647 discloses a technique in which two or more kinds of novolac resins having a specific composition are used in combination as a binder to improve the safelight property. In such a photosensitive lithographic printing plate, the suitability for a ballpoint pen was poor, and the safelight property was insufficient. Further, JP-A-61-243446 contains an o-naphthoquinonediazide sulfonic acid ester of pyrogallol-acetone resin, a novolac resin and an o-naphthoquinonediazide sulfonic acid ester of a phenol formaldehyde resin insoluble in a specific amount of an alkaline aqueous solution. It is described that the photosensitive composition described above improves the safelight property and the over-developing property, but the suitability for a ballpoint pen is poor and the sensitivity and the under-developing property are deteriorated. JP 61-205933
The publication describes that a photosensitive composition using a novolac resin having a specific dispersity as a binder improves safelight property, ballpoint pen suitability and development acceptability, but has a safelight property, The suitability for ballpoint pens is still insufficient. Furthermore, JP-A-61-267043
The publication describes that a photosensitive composition using a novolac resin having a specific m-cresol / p-cresol ratio as a binder has improved safelight properties, ballpoint pen suitability, and development acceptability. . However, as in the previous example, the safelight property and the suitability for the ballpoint pen are still insufficient, and there is a drawback that the suitability for the ballpoint pen is greatly deteriorated particularly when treated with a developing solution having a developing ability higher than a prescribed level.

[Object of the Invention] An object of the present invention is to provide a positive-working photosensitive lithographic printing plate having improved safelight property and suitability for a ballpoint pen without deterioration in development acceptability and sensitivity.

[Structure of the Invention] The above objects of the present invention include (A) an o-quinonediazide compound, (B) a condensation resin of a substituted phenol represented by the following general formula [I] and an aldehyde, and / or o- of the resin. It is achieved by providing a photosensitive lithographic printing plate characterized by containing a naphthoquinone diazide sulfonic acid ester compound and (C) a fluorosurfactant.

General formula [I] (In the formula, R ₁ and R ₂ each represent a hydrogen atom, an alkyl group or a halogen atom, and R ₃ represents an alkyl group having 3 to 8 carbon atoms or a cycloalkyl group having 3 to 8 carbon atoms.) The present invention will be described in more detail.

In the present invention, R ₁ in the above general formula [I] and
Each R ₂ includes a hydrogen atom, an alkyl group (including those having 1 to 3 hydrogen atoms, an alkyl group having 1 to 2 carbon atoms is particularly useful) or a halogen atom (eg, fluorine, chlorine, bromine). Or iodine, particularly preferably chlorine or bromine), and R ₃ represents an alkyl group having 3 to 8 carbon atoms or a cycloalkyl group having 3 to 8 carbon atoms.

Examples of the substituted phenols represented by the above general formula [I] include isopropylphenol, tert-butylphenol, tert-amylphenol, hexylphenol, tert-octylphenol, cyclohexylphenol, 3-methyl-4-chloro-5-tert. -Butylphenol, isopropylcresol, tert-butylcresol, tert-amylcresol, hexylresole,
tert-octyl cresol, cyclohexyl cresol and the like, of which tert-o-octylphenol and tert-butylphenol are particularly preferable.

Further, examples of aldehydes used in the present invention include formaldehyde, benzaldehyde, acetaldehyde, acrolein, crotonaldehyde, aliphatic aldehydes such as furfural, or aromatic aldehydes,
Including those having 1 to 6 carbon atoms. Of these, formaldehyde and benzaldehyde are preferred.

The condensation resin of the substituted phenol and the aldehyde in the present invention is synthesized by polycondensing the substituted phenol represented by the general formula [I] and the aldehyde in the presence of an acidic catalyst. The acidic catalyst used is an inorganic or organic acid such as hydrochloric acid, oxalic acid, sulfuric acid, phosphoric acid, etc., and the mixing ratio of the substituted phenols and the aldehydes is 1 part by mole of the substituted phenols. Kind is 0.
It is used in an amount of 7 to 1.0 mol. The reaction solvent is alcohols,
Acetone, water, tetrahydrofuran, etc. are used.

Specified temperature (-5 to 120 ° C), prescribed time (3 to 48 hours)
After the reaction, the reaction product is obtained by heating under reduced pressure, washing with water and dehydration, or by water precipitation.

The o-naphthoquinone diazide sulfonic acid ester compound of the polymerized resin of the substituted phenols and aldehydes of the present invention is prepared by dissolving the condensation resin in a suitable solvent such as dioxane, and adding o-naphthoquinone diazide sulfonic acid chloride thereto. Is added, and the mixture is heated and stirred, and an alkali such as an alkali carbonate is added dropwise to the equivalent point to effect esterification.

In the esterified product, the condensation rate of o-naphthoquinonediazide sulfonic acid chloride with respect to the hydroxyl groups of phenols (reaction rate% with respect to one hydroxyl group) is 5 to 80%.
Is preferred, more preferably 20-70%, and even more preferably
30-60%. The condensation rate is calculated by obtaining the sulfur atom content of the sulfonyl group by elemental analysis.

Condensation resins of the substituted phenols represented by the above general formula [I] and aldehydes in the photosensitive composition of the present invention and o-naphthoquinonediazide sulfonic acid ester compounds of the resins (hereinafter, these are referred to as “the present invention. The amount of "sensitizer" is preferably 0.05 to 15% by weight, particularly preferably 0.5 to 1.5% by weight.

The oil sensitizer of the present invention has a weight average molecular weight Mw of preferably 5.0 × 10 ^{2 to} 5.0 × 10 ³ , and more preferably
The range is 7.0 × 10 ^{2 to} 3.0 × 10 ³ . Its number average molecular weight Mn
Is preferably in the range of 3.0 × 10 ^{2 to} 2.5 × 10 ³ , and more preferably in the range of 4.0 × 10 ^{2 to} 2.0 × 10 ³ .

The molecular weight of the sensitizer is measured by GPC (gel permeation method).
Chromatography method). The number average molecular weight Mn and the weight average molecular weight Mw are calculated by Morio Tsuge and Tatsuya Miyabayashi. Tanaka Masayuki, “Chemical Society of Japan”, pp. 800-805 (1972
Year), the peaks in the oligomer region are leveled (the peaks and valleys of the peaks are connected).

The fluorine-based surfactant used in the present invention, a hydrogen atom bonded to the carbon atom of the hydrophobic group of the surfactant,
Some or all of them are substituted with fluorine atoms, and any of the following anion type, cation type, nonion type, amphoteric type and polymer type can be used. preferable.

1) Anionic fluorosurfactant As a hydrophilic group, -COOM, -OSO ₃ M, -SO ₃ M, Such as RfCOOM, RfSO ₂ N (R ′) ₂ CH ₂ COOM, RfBNR′C ₂ H ₄ OSO ₃ M, RfSO ₃ M, RfCH ₂ OCmH _2m SO ₃ M, Etc.

(In the formula, Rf is a fluorocarbon group in which a part or all of the hydrogen atoms of the alkyl group are replaced by fluorine atoms (having 2 carbon atoms).
To 20), B represents CO and SO ₂ , R'represents a hydrogen atom or a lower alkyl group, and M represents a hydrogen atom, an alkali metal or an alkaline earth metal. ) 2) Cationic fluorosurfactant As hydrophilic group Containing, for example, Etc.

(In the formula, R ″ represents a hydrogen atom or a lower alkyl group, X represents a halogen acid radical, and HX represents an acid. Rf,
B and R'have the same meanings as Rf, B and R'in the anionic fluorosurfactant, respectively.

3) Amphoteric fluorosurfactants such as RfBNH (C₂H_Four) N (R ')₂C_mH_2mCOO  RfBNHC_mH_2mN (R ')₃Cl   (In the formula, Rf, B, and R'are anionic type surfactants, respectively.
It has the same meaning as Rf, B and R'in the sex agent. ) 4) Nonionic fluorinated surfactant containing -OH, -SH, -O-, etc. as a hydrophilic group
And, for example, RfOH, RfSH, Rf-A- (C₂H_FourO) nR, etc.
Can be

(In the formula, A is CH _{2 m} SO ₂ NR ₁ −, CH _{2 m} O−, CH
_{2 m} CONR ₂ −, −SO ₃ −, −CO ₂ −, and −SO ₂ N (R ₃ ) C
Is a group selected from the group consisting of H ₂ CO ₂ —, and n is 0 to 2
An integer of 0, m represents an integer of 0 to 5, R ₁ , R ₂ and R ₃ each represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or CH ₂ CH ₂ O _x R ₄ , and R ₁ , R ₂ and R ₃ are the same or different. x represents an integer of 1 to 20,
R ₄ represents an alkyl group having 1 to 6 carbon atoms. ) 5) Polymeric fluorosurfactant Polymer compounds containing the structural unit of

Preferred specific examples of the nonionic fluorine-based surfactant are shown below.

[Exemplified Compound] (1) CF ₃ (CF ₂ ) ₇ · (CH ₂ CH ₂ O) ₁₀ H (2) CF ₃ (CF ₂ ) ₇ SO ₂ N (C ₂ H ₅ ) (CH ₂ CH ₂ O) ₁₄ H (3) CF ₃ (CF ₂ ) ₇ SO ₂ N (C ₂ H ₅ ) CH ₂ COO (CH ₂ CH ₂ O) ₁₀ H (4) CF ₃ (CF ₂ ) ₇・ (CF ₂ ) ₃・CON (CH ₃ ) (CH ₂ CH ₂ O) ₁₀ H (5) CF ₃ (CF ₂ ) ₇ SO ₂ N (C ₂ H ₅ ) C ₂ H ₄ (OC ₃ H ₆ ) ₅ OH Used in the present invention The amount of the fluorinated surfactant in the photosensitive composition is preferably 0.05 to 20% by weight, more preferably 0.1 to 1% by weight.

It is generally known that the coating property is improved in the preparation of a photosensitive lithographic printing plate by including a fluorine-based surfactant in the photosensitive composition, but the oil-sensitizing agent of the present invention is used in combination. It is surprising that the present inventors have found that the safelight property and the suitability for a ballpoint pen, which are the objects of the present invention, can be improved.

In the photosensitive composition of the present invention, o-
Contains a quinonediazide compound. The o-quinonediazide compound is preferably an ester compound of a polycondensation resin of o-naphthoquinonediazide sulfonic acid, a phenol and an aldehyde or a ketone.

Examples of the phenols include phenol and o-
Cresol, m-cresol, p-cresol, 3,5
Examples include monohydric phenols such as xylenol, carvacrol and thymol, dihydric phenols such as catechol, resorcinol and hydroquinone, and trihydric phenols such as pyrogallol and phloroglucin. Of these, preferred is monohydric phenol. Examples of the aldehyde include formaldehyde, benzaldehyde, acetaldehyde, crotonaldehyde, furfural and the like. Of these, formaldehyde and benzaldehyde are preferred. Further, examples of the ketone include acetone and methyl ethyl ketone.

Specific examples of the polycondensation resin include phenol
Examples thereof include formaldehyde resin, m-cresol / formaldehyde resin, m-, p-mixed cresol / formaldehyde resin, resorcin / benzaldehyde resin, pyrogallol / acetone resin.

The condensation rate of o-naphthoquinonediazide sulfonic acid with respect to the OH group of the phenol of the o-naphthoquinonediazide compound (reaction rate with respect to one OH group) is preferably 15 to 80%, more preferably 20 to 45%.

The proportion of the o-naphthoquinonediazide compound in the photosensitive composition is preferably 5 to 60% by weight, particularly preferably 10 to 50% by weight.

The photosensitive composition of the present invention preferably contains an alkali-soluble resin. As an alkali-soluble resin,
Novolak resins, vinyl-based copolymers having a phenolic hydroxyl group as described in JP-B-50-8658 and carboxyl groups as described in JP-A-58-122533 and the carboxyl groups thereof. An acrylic copolymer having a unit having an ester group in the molecular structure is preferable. As the novolac resin, a resin obtained by copolycondensing at least one selected from phenol, m-cresol, o-cresol, and p-cresol with formaldehyde is used. Among them, phenol / m-
Cresol / p-cresol / formaldehyde resin,
Preference is given to m-cresol / p-cresol / formaldehyde resins. The above alkali-soluble resins may be used alone or in combination of two or more.

The photosensitive composition of the present invention may contain other additives, if necessary, in addition to the materials described above. Examples of the plasticizer include various low molecular weight compounds such as phthalic acid esters, triphenyl phosphates and maleic acid esters, and printout materials for forming a visible image by exposure. The printout material is composed of a compound that generates an acid or a free radical upon exposure to light and an organic dye that changes its color tone by interacting with the compound. Examples of the compound that generates an acid or a free radical upon exposure to light include O-naphthoquinonediazide-4-sulfonic acid halogenide described in JP-A-50-36209, trihalomethyl-2-pyrone and trihalomethyl-triazine described in JP-A-53-36223, An ester compound of a chloride of o-naphthoquinonediazide-4-sulfonic acid and a phenol or an aniline having an electron-withdrawing substituent described in JP-A-55-6244, described in JP-A-55-77742. And halomethyl-vinyl-oxadiazole compounds and diazonium salts.

Among these, a halomethyl-vinyl-oxadiazole compound is preferable, and a heterocyclic group containing oxygen such as a benzofuryl group described in JP-A-60-138539 is directly or through a vinyl group. A 2-halomethyl-1,3,4-oxadiazole compound having a 5-position is more preferable.

Examples of the organic dye include Victoria Pure Blue BOH [Hodogaya Kagaku], Oil Bull- # 603
[Orient Chemistry], Patent Pure Blue [Sumitomo Sangoku Chemical], Crystal Violet, Brilliant Green, Ethyl Violet, Methyl Green, Erythrosin B, Basic Fuchsin, Malachite Green,
Triphenylmethane series represented by oil red, m-cresol purple, rhodamine B, auramine, 4-p-diethylaminophenyliminonaphthoquinone, cyano-p-diethylaminophenylacetanilide, and the like,
Examples thereof include diphenylmethane-based, oxazine-based, xanthene-based, iminonaphthoquinone-based, azomethine-based or anthraquinone-based dyes. Of these, triphenylmethane dyes are preferable.

Also, a sensitizer for improving sensitivity can be added to the photosensitive composition of the present invention. Examples of such sensitizers include gallic acid derivatives described in JP-A-57-118237. 5-membered cyclic acid anhydrides such as those described in JP-A-52-80022, for example, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, maleic anhydride, succinic anhydride, pyrometic acid, itaconic acid And 6-membered cyclic acid anhydrides such as those described in JP-A-58-11932, such as glutaric anhydride and its derivatives. Of these, cyclic acid anhydrides are preferable, and 6-membered cyclic acid anhydrides are particularly preferable.

A positive photosensitive lithographic printing plate can be formed by dissolving the photosensitive composition of the present invention in a solvent that dissolves each of the above components, and coating and drying this on a suitable support surface. Examples of the solvent that can be used include cellosolves such as methyl cellosolve, methyl cellosolve acetate, ethyl cellosolve, and ethyl cellosolve acetate, dimethylformamide, dimethylsulfoxide, dioxane, acetone, cyclohexanone, trichloroethylene, and methylethylketone. These solvents may be used alone or in admixture of two or more.

As the coating method, conventionally known methods such as spin coating, wire bar coating, dip coating, air knife coating, roll coating, blade coating and curtain coating can be used.

As a support for providing a photosensitive layer using the photosensitive composition of the present invention, a metal plate such as aluminum, zinc, copper, steel, and chromium, zinc, copper, nickel, aluminum, iron, etc. are plated or vapor-deposited. Examples thereof include a metal plate, paper, a plastic film and a resin-coated paper, a paper covered with a metal foil such as aluminum, and a hydrophilized plastic film. Of these, the aluminum plate is preferable. When an aluminum plate is used as the support, it is preferable that surface treatment such as graining treatment, anodizing treatment and, if necessary, sealing treatment is performed. A known method can be applied to these treatments.

The positive-working photosensitive lithographic printing plate to which the photosensitive composition of the present invention is applied can be used in the same manner as conventionally used. For example, through a transparent positive film, it is exposed by a light source such as an ultra-high pressure mercury lamp, a metal halide lamp, a xenon lamp, a tungsten lamp, and then developed with an alcal developer, and only the unexposed portion remains on the surface of the support, and a positive-positive type A relief image of

Examples of the alkaline developer include sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate,
Examples thereof include aqueous solutions of alkali metal salts such as sodium metasilicate, potassium metasilicate, dibasic sodium phosphate, and tribasic sodium phosphate. Alkali metal salt concentration is 0.1
~ 10 wt% is preferred. If necessary, an anionic surfactant, an amphoteric surfactant, or an organic solvent such as alcohol can be added to the developer.

Examples The present invention will be described in more detail below with reference to Examples, but the present invention is not limited to these embodiments.

Example 1 [Synthesis of Oil Sensitizer] Novolak resin (weight average molecular weight Mw =) which is a polycondensation product of p-tert-octylphenol and formaldehyde.
1300) 20 g was dissolved in 240 ml of dioxane, 12.4 g of o-naphthoquinonediazide-5-sulfonyl chloride was added, and after dissolution, a potassium carbonate aqueous solution prepared by dissolving 3.84 g in 25 ml of water was added dropwise at 40-50 ° C. A condensation reaction was performed for a minute.
After the reaction, the reaction solution was poured into diluted hydrochloric acid (1.2 ml of concentrated hydrochloric acid was diluted with 500 ml of water), and the precipitated resin was collected by filtration and dried.

Thus, 29 g of o-naphthoquinonediazide sulfonic acid ester compound of p-tert-octylphenol-formaldehyde resin was obtained. As a result of the analysis, the condensation rate of OH groups was 50%.

Hereinafter, the ester compound will be referred to as "sensitizer [I]".

[Preparation of photosensitive lithographic printing plate] An aluminum plate having a thickness of 0.24 mm was degreased in a 5% by weight sodium hydroxide aqueous solution and then in a 0.5 molar hydrochloric acid aqueous solution at a temperature of 25 ° C and a current density of 60 A / dm. ^2. The electrolytic etching treatment was performed under the treatment time of 30 seconds. Then, after performing desmutting treatment with a 5 wt% sodium hydroxide aqueous solution, anodizing treatment was performed in a sulfuric acid solution. The amount of anodized film was 20 mg / dm ² . Next, it was immersed in a hot aqueous solution at 90 ° C. to perform a sealing treatment.

Subsequently, a photosensitive coating solution having the following composition was applied to the aluminum support using a spin coater and dried at 100 ° C. for 4 minutes to obtain a photosensitive lithographic printing plate (A).

(Composition of photosensitive coating solution) -Ester compound of naphthoquinone- (1,2) -diazide- (2) -5-sulfonic acid chloride and pyrogallol-acetone resin (described in Synthesis Example 2 of JP-A-60-143345) Compound) 1.88g ・ Copolycondensation resin of phenol, m-, p-mixed cresol and formaldehyde (the molar ratio of phenol, m-cresol and p-cresol at the time of synthesis was 20: 4).
8:32, weight average molecular weight Mw = 7400, number average molecular weight Mn = 140
0) 6.32g-Fluorosurfactant (Exemplified compound (2)) 0.0164g-Sensitizer [I] (condensation rate = 50 mol%, weight average molecular weight Mw = 1700) 0.08
2 g-Victoria Pure Blue BOH [Hodogaya Chemical Co., Ltd.] 0.072 g-Ethyl cellosolve 80 ml-Methyl cellosolve 20 ml The coating weight after drying was about 22 mg / dm ² .

On the photosensitive lithographic printing plate (A) thus obtained, a step tablet for sensitivity measurement (manufactured by Eastman Kodak Company)
No.2, in close contact gray scale) of each density difference 0.15 21 steps, the conditions of 2KW metal halide lamp [Iwasaki Electric Co., Ltd. idle fins 2000] 8.0mW / cm ² as a light source, 7
It was exposed for 0 seconds.

This sample was treated with a 4 wt% potassium metasilicate aqueous solution at 25 ° C.
After development for 45 seconds, the non-image area was completely removed to obtain a lithographic printing plate. When the sensitivity was measured with the gray scale of the step tablet, the 41 / 2th stage was completely developed (clear).

Next, in order to examine the development acceptability (development latitude), a developer having a more concentrated alcal concentration than the standard 4% by weight potassium metasilicate aqueous solution and a developer having a higher alkali concentration are prepared. Using the sample exposed for 70 seconds, the developing property for a developing solution having a lowered developing ability (under developing property) and the developing property for a developing solution having an excessive developing ability (over developing property) were examined.
In the examination of under-development property, the solubility of non-image area was judged by developing with 1.9 wt% and 1.7 wt% potassium metasilicate aqueous solution at 25 ° C. for 45 seconds, respectively. The better the underdeveloping property is, the more the photosensitive layer in the non-image area is dissolved by the diluted developer. In the study of over-developing property, a 6.0 wt% potassium metasilicate aqueous solution was used at 25 ° C for 60 seconds and 7.2 wt%.
Each is developed with an aqueous solution of potassium metasilicate at 25 ° C. for 90 seconds, and the solid step number (the minimum step number in which the photosensitive layer is completely left in the gray scale of the step tablet) is measured. The difference from the number of solid steps at the time of development (4 wt% potassium metasilicate aqueous solution, 25 ° C., 45 seconds) was determined. The smaller the difference in the number of solid steps and the closer to standard development, the less the erosion of the unexposed area and the better the over-developing property. Good development tolerance means that both underdeveloping property and overdeveloping property are good.

Further, in order to examine the safelight property, before exposing and developing the photosensitive lithographic printing plate (A), it is exposed to a white fluorescent lamp (310 lux) for 15 minutes to cause optical fog. The standard development processing was performed and the film reduction rate of the photosensitive layer was measured. The film reduction rate is a value that indicates how much the film thickness decreases when developed with light fog with respect to the film thickness of the photosensitive layer of a photosensitive lithographic printing plate developed without light fog. The smaller the value, the better the safelight property. In order to examine the reduction in printing durability due to light fog, the above-mentioned photosensitive lithographic printing plate (A) was exposed by adhering a positive original film as described above, and then exposed by a white fluorescent lamp as described above. After fog was generated, standard development processing was performed to obtain a lithographic printing plate [I]. On the other hand, another lithographic printing plate [II] was processed in the same way as the other processing without giving light fog.
Was produced. The two lithographic printing plates [I] and [II] were placed side by side on an offset printing machine (Hamaduster 900CDX) to perform printing. The end point of the printing durability was determined when the solid portion of the image area was peeled off and printing could not be performed.

Next, in order to examine the suitability for a ballpoint pen, a ballpoint pen (I) [ZEBRAN5100 black manufactured by Zebra Corp.], a ballpoint pen (II) [Dragon Pencil ( Co., Ltd., GOLF Blue] and ballpoint pen (III) [Pilot Fountain Pen Co., Ltd., BS-
A line was drawn by using three ballpoint pens of [Blue] with a writing pressure of 20 g and left for 1 minute, and then developed under the above-mentioned over-developing conditions (6.0%, 25 ° C., 60 seconds) without exposure. To evaluate the suitability for a ballpoint pen, the degree of erosion of the photosensitive layer after handwriting was judged in 3 ranks.

Table 1 shows the examination results of the sensitivity, the developability, the safelight property, and the suitability for a ball-point pen obtained above.

Comparative Example 1 A photosensitive lithographic printing plate (B) was prepared by removing the surfactant of Exemplified Compound (2) from the photosensitive coating liquid of Example 1 on the same support as in Example 1 and drying the same. Got

The coating weight after drying was about 22 mg / dm ² .

Using the photosensitive lithographic printing plate (B), the sensitivity, the development acceptability, the safelight property and the ballpoint pen suitability were evaluated in the same manner as in Example 1. Table 1 shows the results.

Comparative Example 2 The photosensitive coating liquid of Example 1 from which the oil sensitizer [I] was removed was coated on the same support as in Example 1 and dried to give a photosensitive lithographic printing plate (C). Obtained.

The coating weight after drying was about 22 mg / dm ² .

Using the photosensitive lithographic printing plate (C), the sensitivity, the development acceptability, the safelight property, and the ballpoint pen suitability were evaluated in the same manner as in Example 1. Table 1 shows the results.

Comparative Example 3 On the support of Example 1, the following photosensitive coating liquid was applied and dried in the same manner as in Example 1 to obtain a photosensitive lithographic printing plate (D).

(Composition of photosensitive coating liquid) -Ester compound of naphthoquinone- (1,2) -diazide- (2) -5-sulfonic acid chloride and pyrogallol-acetone resin (described in JP-A-61-243446, Synthesis Example 2) Compound) 1 g ・ Copolycondensation resin of phenol, m-, p-mixed cresol and formaldehyde (Mn = 1.25 × 10 ³ , Mw = 1.03 × 1
0 ⁴ , the molar ratio of phenol to cresol is 4: 6 3.5 g 2-Trichloromethyl-5- [β- (2'-benzofuryl) vinyl] -1,3,4-oxadiazole 0.03 g-Victoria Pure Blue BOH p (manufactured by Hodogaya Chemical Co., Ltd.) 0.1 g-Sensitizer [I] 0.17 g-Methyl cellosolve 50 ml The coating weight after drying was about 22 mg / dm ² .

Using this photosensitive lithographic printing plate (D), the sensitivity, development acceptability, safelight property, and ball-point pen suitability were evaluated in the same manner as in Example 1. Table 1 shows the results.

Comparative Example 4 The photosensitive coating liquid was applied and dried on the support of Example 1 in the same manner as in Example 1 to obtain a photosensitive lithographic printing plate (E).

(Photosensitive coating liquid composition) -Ester compound of naphthoquinone- (1,2) -diazide- (2) -5-sulfonic acid chloride and pyrogallol-acetone resin (described in Example 1 of US Pat. No. 3,635,709) Compound) 1.7 g-co-polycondensation resin of phenol, m-, p-mixed cresol and formaldehyde (SK-102 manufactured by Sumitomo Durez Co., Ltd.) (described in Example 1 of JP-A-61-6647). Compound)
4.42g ・ Copolycondensation resin of phenol, m-, p-mixed cresol and formaldehyde (SK-105 manufactured by Sumitomo Dures Co., Ltd.) (Compound described in Example 1 of JP-A No. 61-6647)
2.08g-Sensitizer [I] 0.082 g-Victoria Pure Blue BOH (Hodogaya Chemical Co., Ltd.) 0.072 g-Ethyl cellosolve 80 ml-Methyl cellosolve 20 ml The coating weight after drying was about 22 mg / dm ² . .

Using this photosensitive lithographic printing plate (E), the sensitivity, development acceptability, safelight property and ballpoint pen suitability were evaluated in the same manner as in Example 1. Table 1 shows the results.

Comparative Example 5 The following photosensitive coating liquid was applied onto the support of Example 1 and dried in the same manner as in Example 1 to obtain a photosensitive lithographic printing plate (F).

(Photosensitive coating liquid composition) -Ester compound of naphthoquinone- (1,2) -diazide- (2) -5-sulfonic acid chloride and pyrogallol-acetone resin (Mn = 1500, Mw = 1700, condensation rate 50 mol% )
1.67 g-Copolycondensation resin of phenol, m-, p-mixed cresol and formaldehyde (Mw = 9300, dispersity = 6.2) (resin described in Example 1 of JP-A-61-205933) 6.53 g Sensitizer [I] 0.082 g-Victoria Pure Blue BOH [manufactured by Hodogaya Chemical Co., Ltd.] 0.072 g-Ethyl cellosolve 80 ml-Methyl cellosolve 20 ml The coating weight after drying was about 22 mg / dm ² .

Using this photosensitive lithographic printing plate (F), the sensitivity, development acceptability, safelight property and ballpoint pen suitability were evaluated in the same manner as in Example 1. Table 1 shows the results.

Comparative Example 6 A photosensitive coating solution was applied and dried on the support of Example 1 in the same manner as in Example 1 to obtain a photosensitive lithographic printing plate (G).

(Composition of photosensitive coating liquid) -Ester compound of naphthoquinone- (1.2) -diazide- (2) -5-sulfonic acid chloride and pyrogallol-acetone resin (Mn = 16 of pyrogallol-acetone resin)
40, Mw = 3010) (Compound described in JP-A No. 61-267043, Example 2) 1.88 g-co-polycondensation resin of m-cresol, p-cresol and formaldehyde (m-cresol at the time of synthesis) The weight ratio of p-cresol is 75:25) (resin described in JP-A-61-267043, Example 2) 6.32 g-sensitizer [I] 0.082 g-Victoria Pure Blue BOH [Hodogaya Chemical ( Co., Ltd.] 0.072 g-methyl cellosolve 60 ml-methyl cellosolve 40 ml The coating weight after drying was about 22 mg / dm ² .

Using this photosensitive lithographic printing plate (G), the sensitivity, development acceptability, safelight property and ballpoint pen suitability were evaluated in the same manner as in Example 1. Table 1 shows the results.

Comparative Example 7 A composition obtained by removing the oil-sensitizing agent [I] and the fluorinated surfactant of the exemplified compound (2) from the photosensitive coating liquid of Example 1 was used.
The same support as in Example 1 was applied and dried in the same manner to obtain a photosensitive lithographic printing plate (H).

The coating weight of the photosensitive layer after drying was about 22 mg / dm ² .

Using this photosensitive lithographic printing plate (H), the sensitivity, development acceptability, safelight property and ballpoint pen suitability were evaluated in the same manner as in Example 1. Table 1 shows the results.

The results of measurement of sensitivity, development tolerance, safelight property, and ballpoint pen suitability performed for Example 1 and Comparative Examples 1 to 7 are summarized in Table 1.

In the suitability for the ballpoint pen of Table 1, the mark A has little erosion in the image area.

As for the mark B, erosion was observed as above, and the grain of the support under the photosensitive layer was slightly exposed.

As for the C mark, erosion was remarkably observed, and the grains of the support below the photosensitive layer were completely exposed.

Means that.

 In the under-developing property, the mark ◯ indicates that the photosensitive layer in the non-image area is completely dissolved and removed.

The part marked with Δ remains as above.

The mark x is almost the same as above, but not dissolved.

Means that.

In the over-developing property, the numerical value means the difference in the number of solid steps from the standard development, and the-mark means that the erosion of the image area is remarkable and the over-developing property is so poor that the solid step number cannot be determined.

The following is clear from the results of the above Examples and Comparative Examples.

That is, from the comparison between Example 1 and Comparative Example 1 or 2,
Without the fluorine-based surfactant, the safelight property, the ball-point pen suitability and the over-developing property are inferior. It can be seen that a photosensitive lithographic printing plate excellent in all of the above properties can be obtained by including both the surface active agent and the oil sensitizer of the present invention. The photosensitive lithographic printing plate (D) of Comparative Example 3 is excellent in safelight property and over-developing property, but is largely inferior in sensitivity, under-developing property and ballpoint pen suitability. The photosensitive lithographic printing plate (E) of Comparative Example 4 was improved in safelight property, and the photosensitive lithographic printing plates (F) and (G) of Comparative Examples 5 and 6 were improved in ballpoint pen suitability and safelight property. However, when evaluated under the above-mentioned experimental conditions, both the ballpoint pen suitability and the safelight property are poor.
Further, comparison between Comparative Examples 1, 2 and 7 and Example 1 reveals that the combination of the exemplified compound (2) which is a fluorosurfactant and the oil sensitizer [I] of the present invention makes it possible to improve over-developing property and ballpoint pen. A synergistic effect is observed in aptitude and safelight property.

The performance of the photosensitive lithographic printing plate cannot be evaluated by only one characteristic. Some characteristics must be comprehensively evaluated. Photosensitive lithographic printing plate (A) of Example 1
Photosensitive lithographic printing plates (B) to (H) of Comparative Examples 1 to 7 other than
Has a major drawback in at least one of the properties shown in Table 1, or is inferior to the photosensitive lithographic printing plate (A) in ballpoint pen suitability and safelight property.
The photosensitive lithographic printing plate (A) of the present invention is excellent in over-developing property and under-developing property and has a wide development tolerance, and is also excellent in sensitivity, ballpoint pen suitability and safelight property as a whole. Is.

[Effects of the Invention] As described above, by using the photosensitive composition of the present invention, a photosensitive lithographic printing plate improved in safelight property and suitability for ballpoint pen without deterioration in sensitivity and development acceptability. was gotten.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Norito Suzuki, No. 1 Sakura-cho, Hino-shi, Tokyo, Konishi Roku Photo Industrial Co., Ltd. Industrial Research Institute, Inc. (72) Inventor, Yoshiko Kobayashi, 1000, Kamoshida-cho, Midori-ku, Yokohama, Kanagawa Sanryo Kasei Industry Co., Ltd. (56) Reference JP-A-58-105143 (JP, A)

Claims (1)

[Claims] 1. An (A) O-quinonediazide compound, (B)
Containing a condensed resin of a substituted phenol represented by the following general formula [I] and an aldehyde, and / or an O-naphthoquinonediazide sulfonic acid ester compound of the resin and (C) a fluorine-based surfactant. And a photosensitive lithographic printing plate. General formula [I] (In the formula, R ₁ and R ₂ each represent a hydrogen atom, an alkyl group or a halogen atom, and R ₃ represents an alkyl group having 3 to 8 carbon atoms or a cycloalkyl group having 3 to 8 carbon atoms.)