JPH087432B2 - Photosensitive composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a photosensitive composition, and in particular, it is excellent in photocrosslinking property, and has high sensitivity and high printing durability. The present invention relates to a photosensitive composition suitable for use in a lithographic printing plate.

[Conventional technology]

The majority of those used as photosensitive substances in printing materials that have been previously made photosensitive are diazonium compounds, and the most commonly used of these are diazo resins represented by formaldehyde condensation products of p-diazodiphenylamine. is there.

The composition of the photosensitive layer of the photosensitive lithographic printing plate using a diazo resin, for example, as described in U.S. Pat.No. 2,714,066, the diazo resin alone, that is, without a binder, for example, As described in JP-A-50-30604, it can be classified into a mixture of a binder and a diazo resin, but in recent years, most of photosensitive lithographic printing plates using a diazonium compound have It is composed of a diazonium compound and a polymer that serves as a binder to provide high printing durability.

Heretofore, with respect to polymers serving as these binders, attempts have been made to firmly cure the photosensitive layer after exposure by containing a hydroxyl group or a nitrile group in the polymer and increasing the photocrosslinking property with the diazonium compound. It was As such an example, for example, JP-A-60-
Polymers such as those described in 198742 and JP-A-62-123453 can be mentioned.

However, these polymers also have the drawback that they do not have sufficient sensitivity and printing durability because the efficiency of the binder to crosslink with the diazonium compound during exposure is not sufficient.

[Problems to be Solved by the Invention]

The object of the present invention is to overcome the above-mentioned drawbacks, to provide a lithographic printing plate which is excellent in photocrosslinking property between a binder and a diazonium compound, has high sensitivity, and can provide a lithographic printing plate having high printing durability. To provide a sex composition.

[Means for solving the problem]

As a result of intensive studies to achieve the above objects, the present inventors have found that by using a thiocarboxyl group- and / or dithiocarboxyl group-containing polymer compound as a binder,
The inventors have found that these objects are achieved and have reached the present invention.

That is, the present invention provides a photosensitive composition containing a diazonium compound and a polymer compound having at least one thiocarboxy group and / or dithiocarboxyl group.

Examples of the diazonium compound used in the present invention include diazonium compounds described in U.S. Pat.No. 3867147, diazonium compounds described in U.S. Pat. The diazo resin represented by the condensate of this is useful. Preferred diazo resins include, for example, hexafluorophosphate, tetrafluoroborate and phosphate of a condensate of p-diazodiphenylamine and formaldehyde or acetaldehyde. In addition, sulfonates of a condensate of p-diazodiphenylamine and formaldehyde as described in U.S. Pat. No. 3,300,309 (for example, p-toluenesulfonate, dodecylbenzenesulfonate, 2-methoxy-4-). Hydroxy-5-benzoylbenzenesulfonate, etc.), phosphinate (eg, benzenephosphinate), hydroxy group-containing compound salt (eg,
2,4-dihydroxybenzophenone salt and the like, organic carboxylate and the like are also preferable.

Furthermore, as shown in JP-A-58-27141, 3-
Also suitable is a mesitylene sulfonate obtained by condensing methoxy-4-diazo-diphenylamine with 4,4'-bis-methoxy-methyl-diphenyl ether.

The content of these diazonium compounds in the photosensitive composition is 0.5 to 50% by weight, preferably 3 to 20% by weight.
If necessary, two or more diazonium compounds may be used in combination.

On the other hand, the polymer compound used in the present invention is a polymer compound having at least one thiocarboxyl group and / or dithiocarboxyl group.

This thiocarboxyl group and / or dithiocarboxyl group may be contained in the main chain of the polymer compound used in the present invention, or may be contained in the side chain.

Preferred examples of the polymer compound used in the present invention include those represented by the general formula (I) or (II).

In the formula, R ¹ is a trivalent organic group which may have a substituent (preferably an aliphatic hydrocarbon group, an aromatic hydrocarbon group,
Heterocyclic group) or a nitrogen atom, and R ² is a divalent organic group which may have a single bond or a substituent (preferably an aliphatic hydrocarbon group, an aromatic hydrocarbon group, a heterocyclic group). Or
A group containing a nitrogen atom, an oxygen atom or a sulfur atom is shown. X represents an oxygen atom or a sulfur atom.

Represents a main chain or side chain of a polymer compound which may contain a thiocarboxyl group and / or a dithiocarboxyl group.

The polymer compound serving as the main chain (matrix) of the polymer compound of the present invention may be any compound that can be mixed with a diazonium compound and used as a photosensitive composition, and examples thereof include polyvinyl acetal, polyvinyl alcohol, and acrylic. Examples thereof include acid-based polymers, methacrylic acid-based polymers, polystyrene-based polymers, polyesters, polyamides, polyurethanes, polyureas, polythioamides, polythiourethanes, and epoxy resins, and preferably polyvinyl acetals, acrylic acid-based polymers, methacrylic acid-based polymers. , Polyurethane, and more preferably,
Polyurethane can be used in terms of abrasion resistance.

Further, the polymer compound used in the present invention, in order to make the photosensitive composition soluble in an aqueous alkaline developer,
It is desirable to have an acidic group. Here, as the acidic group, for example, a carboxyl group, a thiocarboxyl group, a dithiocarboxyl group, a phenolic hydroxyl group, a phenolic mercapto group, an N-sulfonylamide group, an N-sulfonylureido group, an N-aminosulfonylamide group, N-
Examples thereof include an acylamide group and an N-acylureido group.

Specific examples of the polymer compound used in the present invention include:
Examples of the polymer compound have the following structures.

The content of the thiocarboxyl group and / or dithiocarboxyl group in the polymer compound used in the present invention is
Expressed in terms of the content of sulfur atoms by elemental analysis, it is preferably about 0.1 weight percent or more, more preferably about 0.5-.
32 weight percent, most preferably about 2 to 16 weight percent.

The acid value of the polymer compound used in the present invention is preferably about 0.01 meq / g or more, more preferably about 0.3 to 5 meq / g,
Most preferably, it is about 0.5-2.5 meq / g.

The molecular weight of the polymer compound used in the present invention is preferably 1,000 or more on a weight average basis, more preferably 5,000 or more,
Most preferably, it is in the range of 20,000 to 200,000.

The molecular weight dispersion (w / n) is preferably about 1.1 or more, more preferably about 1.5-50, most preferably about 2-10.

These polymer compounds may be used alone or in combination. The content of these polymer compounds contained in the photosensitive composition is about 50 to 99.5% by weight, preferably about 55 to
It is 95% by weight.

In the photosensitive composition of the present invention,
Other resins can be mixed in in amounts up to 50% by weight.
Examples of the mixed resin include polyamide resin, epoxy resin, polyacetal resin, acrylic resin, methacrylic resin, polystyrene resin, novolac type phenol resin, polyurethane resin, polyester resin, and polyurea resin.

If necessary, a dye, a pigment, a stabilizer, a filler, a surfactant, a plasticizer and the like may be added to the photosensitive composition of the present invention to improve the performance. Suitable dyes include oil-soluble dyes such as CI26105 (Oil Red RR), C.I.
I.21260 (Oil Scarlet # 308), CI74350 (Oil Blue), CI52015 (Methylene Blue), CI425
Includes 55 (Chrysle Violet) and CI42595 (Victoria Pure Blue).

As a stabilizer, phosphoric acid, phosphorous acid, oxalic acid, p-
Toluenesulfonic acid, dipicolinic acid, malic acid, tartaric acid, 2-methoxy-4-hydroxy-5-benzoyl-
Benzenesulfonic acid, butylnaphthalenesulfonic acid, p
-Hydroxybenzenesulfonic acid, and the like.

The photosensitive composition of the present invention is usually used after being dissolved in a solvent, applied on a suitable support and dried. The coating amount is about 0.1 to 5 g / m ² , preferably 0.3 to 3 g / m ² by dry weight.

Examples of such a solvent include methanol, ethanol, isopropanol, n-butanol, t-butanol, 2-methoxyethanol, 1-methoxy-2-propanol, 2-ethoxyethanol, 2-methoxyethyl acetate, ethylene glycol, tetrahydrofuran, dioxane. , Dimethyl sulfoxide, N, N-dimethylformamide, N, N-dimethylacetamide, acetone, methyl ethyl ketone, methyl lactate, etc. and mixtures thereof.

The support to which the photosensitive composition of the present invention is applied is, for example, paper, paper laminated with plastics (for example, polyethylene, polypropylene, polystyrene, etc.), for example, aluminum (including aluminum alloy), zinc, and the like. Plates of metal such as copper, plastics such as cellulose diacetate, cellulose triacetate, cellulose propionate, cellulose butyrate, cellulose acetate butyrate, cellulose nitrate, polyethylene terephthalate, polyethylene, polystyrene, polypropylene, polycarbonate, polyvinyl acetal, etc. Film, a paper or plastic film on which the above metal is laminated, or vapor-deposited. Among these supports, the aluminum plate is particularly preferable because it is dimensionally remarkably stable and inexpensive. Furthermore,
A composite sheet in which an aluminum sheet is bonded onto a polyethylene terephthalate film as described in JP-B-48-18327 is also preferable.

Further, in the case of a support having a surface of a metal, particularly aluminum, mechanical or electrochemical surface roughening treatment, immersion treatment in an aqueous solution of sodium silicate, potassium fluorozirconate, phosphate or the like, or anodization Surface treatment such as treatment is preferably performed. In addition, U.S. Pat.
As described in Japanese Patent No. 066, an aluminum plate immersed in an aqueous solution of sodium silicate, Japanese Patent Publication No. 47125
Aluminum plate after anodizing treatment as described in U.S. Pat. No. 4,476,006; mechanical surface roughening and electrolysis as described in U.S. Pat.No. 4,476,006. Aluminum supports treated with a combination of roughening are also preferably used. Examples of the mechanical roughening treatment method include a ball polishing method, a brush polishing method, a liquid honing polishing method, and a buff polishing method. As a method of electrochemically roughening the surface, a method of electrolytically etching with an alternating current using an aqueous solution containing hydrochloric acid, nitric acid or a mixture thereof as an electrolytic solution can be mentioned. Further, the anodizing treatment, for example, an inorganic acid such as phosphoric acid, chromic acid, sulfuric acid, boric acid, or an organic acid such as oxalic acid, sulfamic acid or an aqueous solution or a non-aqueous solution of a salt thereof, or two or more kinds thereof. It is carried out by passing an electric current using an aluminum plate as an anode in the combined electrolytic solution.

It is also preferable that after the graining treatment, the anodic oxidation, and the sealing treatment are performed. Such sealing treatment is performed by immersion in an aqueous solution of sodium silicate, hot water and a hot aqueous solution containing an inorganic salt or an organic salt, and a steam bath.

Further, silicate electrodeposition as described in US Pat. No. 3,658,662 is also effective.

The photosensitive composition of the present invention coated on a support is exposed through a transparent original image having a line image, a halftone image, etc., and then developed with an aqueous developer or an organic solvent-based developer to give an original image. And give a relief image of the negative.

Light sources used for exposure include carbon arc lamps, mercury lamps, xenon lamps, tungsten lamps, metal halide lamps and the like.

〔The invention's effect〕

It has excellent solubility in an organic coating solvent when the photosensitive composition of the present invention is applied on a support, and after coating, drying and image exposure, the unexposed portion is treated with an alkaline developer or an organic solvent-based developer. It has excellent developability during development and high sensitivity. The obtained relief image has good abrasion resistance, oil sensitivity and adhesiveness to a support, and when used as a printing plate, a large number of excellent printed matters can be obtained.

"Examples" Hereinafter, the present invention will be described in more detail with reference to Synthesis Examples and Examples, but the contents of the present invention are not limited thereto.

Synthesis Example 1 20 g of Denka Butyral # 4000-2 (Polyvinyl butyral manufactured by Denki Kagaku Kogyo Co., Ltd.) was placed in a 500 ml three-necked round bottom flask equipped with a condenser and a stirrer, and 200 ml of N, N-dimethylformamide was added. Dissolved. To this was added 6.90 g (0.0682 mole) of triethylamine, 0.93 g (0.076 mole) of 4-N, N-dimethylaminopyridine and 12.4 g (0.0758 mole) of thiophthalic anhydride, and the mixture was heated at 60 ° C. for 3 hours with stirring. After adding 100 ml of acetic acid to the reaction solution, the mixture was poured into 4 l of water while stirring to precipitate a white polymer.
This polymer was separated by filtration, washed with water, and dried under reduced pressure to obtain 28 g of a polymer.

When the molecular weight was measured by gel permeation chromatography (GPC), the weight average (polystyrene standard) was 190,000. The acid value measured by titration was 1.99 meq / g. The sulfur content measured by elemental analysis was 6.49 weight percent. In addition,
The structure and composition of the polymer were determined by elemental analysis, NMR, IR and acid number. (Polymer compound No. 1 of the present invention) Synthesis Example 2 In a 300 ml three-necked round bottom flask equipped with a condenser and a stirrer, 16.0 g of m-xylylene diisocyanate (0.1
00mole), 2,2-bis (hydroxymethyl) thiopropionic acid 7.51g (0.0500mole), diethylene glycol 5.3
1 g (0.0500 mole) and 100 ml of 1,4-dioxane were added,
The mixture was heated under reflux for 5 hours with stirring.

After adding 50 ml of methanol to this, the mixture was poured into 4 l of water while stirring to precipitate a white polymer. This polymer was separated by filtration, washed with water, and dried under reduced pressure to obtain 27 g of a polymer.

The weight average molecular weight (polystyrene standard) measured by GPC was 63,000. Acid value by titration is 1.68meq
It was / g. The sulfur content by elemental analysis was 5.48 weight percent. The structure and composition of the polymer were confirmed by elemental analysis, NMR, IR and acid value.

(Polymer compound No. 14 of the present invention) Example An aluminum plate having a thickness of 0.24 mm and a nylon brush and 400
The surface was sand-grained with an aqueous suspension of pumicestone and washed thoroughly with water. This was immersed in a 10% aqueous solution of sodium hydroxide at 70 ° C. for 60 seconds for etching, washed with running water, neutralized with 20% nitric acid, and then washed with a light emitting device of JP-A-53-67.
No. 507, the electrochemical surface roughening method, that is, V _A = 12.7 V,
Using a sinusoidal alternating wave current of V _C = 9.1 V, electrolytic surface roughening treatment was performed in a 1% aqueous nitric acid solution with an electric quantity at the anode of 160 Coulomb / dm ² . Continue to soak in 30% sulfuric acid aqueous solution at 55 ℃
After desmutting for 2 minutes, it was anodized in a 7% sulfuric acid aqueous solution so that the coating amount of aluminum oxide was 2.0 g / m ² . Then, it was immersed in a 3% aqueous solution of sodium silicate at 70 ° C. for 1 minute, washed with water and dried. The following photosensitive liquids (I) to (V) were added to the aluminum plate obtained as described above.
Was applied using a wheeler and dried at 80 ° C. for 2 minutes. The dry weight was 2.0 g / m ² .

The polymer compounds of the present invention using the photosensitive liquids (I) to (V) are shown in Table 1.

(Photosensitive liquid) Next, as comparative examples, photosensitive liquids (VI) and (VII) using the following polymeric compounds A and B, respectively, instead of the polymeric compound of the present invention in the photosensitive liquid were similarly applied and dried. The dry weight was 2.0 g / m ² .

(Polymer compound A used in Comparative Example) It is a polymer compound having a structure of a / b / c in a molar ratio of 30 /
It was 50/20.

The weight average molecular weight (polystyrene standard) is 65,0.
It was 00.

It is a high molecular compound with a composition of a / b in a molar ratio of 60/40.
Met.

The weight average molecular weight (polysterene standard) is 45,0.
It was 00.

Each of the photosensitive lithographic printing plates (I) to (VII) obtained using the photosensitive liquids (I) to (VII) was image-exposed with a PS light manufactured by Fuji Photo Film Co., Ltd. for 1 minute from a distance of 1 m, After immersing in the following developer at room temperature for 1 minute, the surface was lightly rubbed with absorbent cotton to remove the unexposed area, and planographic printing plates (I) to (VII) having bright blue images were obtained. Also, at this time, using the PS step guide P manufactured by Fuji Photo Film Co., Ltd.,
The number of solid steps on the plate was examined.

(Developer) Each of the printing plates was used to print on high-quality paper with a commercially available ink using a KOR type printer manufactured by Heidelberg. When the final printing number of planographic printing plates (I) to (VII) was examined,
It was as shown in the table.

From Table 1, lithographic printing plates (I) to (V) using the photosensitive composition containing the thiocarboxyl group- and / or dithiocarboxyl group-containing polymer compound of the present invention were compared with Comparative Examples (VI) and (VI). It can be seen that it has higher sensitivity than VII), has a large number of printed sheets, and has excellent printing durability.

Claims (1)

[Claims] 1. A photosensitive composition comprising a diazonium compound and a polymer compound having at least one thiocarboxyl group and / or dithiocarboxyl group.