JPH081517B2 - Photosensitive lithographic printing plate - Google Patents

Description

TECHNICAL FIELD The present invention relates to a photosensitive lithographic printing plate, and more specifically,
The present invention relates to a photosensitive lithographic printing plate in which plates are stacked without sandwiching interleaving paper at a temperature of room temperature or higher and the plates do not stick to each other even after a long time under pressure.

<Prior Art> Conventionally, the photosensitive lithographic printing plate is sandwiched by a slip sheet.
It was often packaged in units of 20 to 50 and supplied to users in a case, but for users who use a large amount at one time, stack 500 to 1000 sheets without sandwiching interleaving paper. In recent years, it has been increasingly supplied in the form of packaging that is applied with sufficient pressure from the top so that the cargo will not fall apart. If it is placed in a high temperature place for a long time in such a packaging form, the surface of the photosensitive layer and the back surface of the plates stacked on top of it stick to each other, and it can be transported by an automatic plate making machine. There was a problem that it was lost and the workability was significantly impaired.

On the other hand, it is known to include a fluorine-based surfactant in the photosensitive composition, and for example, in JP-A-54-135004, a photosensitive composition dissolved or dispersed in an organic solvent is applied and dried. In this case, in order to provide a uniform photosensitive layer on the support, it is disclosed that the photosensitive composition contains a fluorine-based surfactant. However, the fluorinated surfactants used here do not contain any substituent containing a phosphorus atom, and even when such a surfactant is used, the sticking between the plates described above may occur. It cannot be solved. Further, in JP-A-59-222843,
A method for producing a negative type fountain solution-free lithographic printing plate characterized by coating a photosensitive composition containing a fluorosurfactant and a quinonediazide compound on a support, and coating a silicone rubber layer on the photosensitive composition. Is disclosed. In this invention, the fluorine-containing surfactant is added in order to prevent the occurrence of coating unevenness, pinholes, cissing, etc. when the photosensitive layer coating liquid is applied and dried on the support. It is not intended to eliminate the plate-to-plate sticking problem described above. In such a photosensitive lithographic printing plate, a silicone rubber layer is further formed on the photosensitive composition layer.
Alternatively, since a laminate layer of polypropylene film or the like is further provided, the photosensitive composition layer is not exposed at all on the surface of the photosensitive lithographic printing plate, and the releasability of the surface is very good. This is because the problem of sticking with the original does not exist. However, in such a photosensitive lithographic printing plate without an overcoat layer, or a photosensitive lithographic printing plate in which a dot-shaped mat layer is further provided on the photosensitive composition layer in order to shorten the vacuum adhesion time, Since at least a part of the photosensitive composition layer is exposed on the surface of the photosensitive lithographic printing plate, at least a part of the surface of the photosensitive composition layer when the plates are stacked without interposing the interleaving paper, It comes into contact with the backside of the plates stacked on top of it, causing the plate-to-plate sticking problem described above. When 50% or more of the surface area of the photosensitive composition layer is exposed on the surface of the photosensitive lithographic printing plate, the above-mentioned problem of sticking between the plate and the plate is particularly remarkable.

<Object of the Invention> An object of the present invention is to prevent the plates from sticking to each other even after a long time under pressure with the plates stacked by sandwiching interleaving paper at a temperature of room temperature or higher. It is to provide a photosensitive lithographic printing plate.

<Structure of the Invention> As a result of various studies, the inventors of the present invention obtained a photosensitive lithographic printing plate containing a surfactant having a substituent containing a perfluoroalkyl group and a phosphorus atom in the photosensitive composition. The inventors have found that the above objects can be achieved and have reached the present invention.

The surfactant used in the present invention is characterized by having both a perfluoroalkyl group and a substituent containing a phosphorus atom, and if these two substituents are present, there are no other restrictions such as molecular weight. However, a surfactant having only one of the substituents does not sufficiently achieve the above object. The term "perfluoroalkyl group" as used herein refers to a group in which 50% or more of hydrogen atoms bonded to carbon atoms of a hydrophobic group of a normal surfactant are substituted with fluorine atoms.

Hereinafter, typical specific examples of the surfactant of the present invention will be described.

C ₈ F ₁₇ SO ₂ N (C ₂ H ₅ ) CH ₂ CH ₂ OPO (OH) ₂ C ₈ F ₁₇ SO ₂ N (C ₃ H ₇ ) CH ₂ CH ₂ OPO (ONa) ₂ CHF ₂ (CF ₂ ) ₉ CH ₂ OPO (ONa) ₂ CHF ₂ (CF ₂ ) ₇ PO (OH) ₂ (C ₈ F ₁₇ SO ₂ N (C ₂ H ₅ ) CH ₂ CH ₂ O) ₂ POONH ₄ C ₈ F ₁₇ SO ₂ N (C ₂ H ₅ ) CH ₂ CH ₂ OP (OCOC ₆ H ₅ ) ₂ Minnesota Mining Manufacturing is a commercially available surfactant.
ufacturing) (3M) FC-161, Dainippon Ink Co., Ltd.
Made Megafac F-191, Asahi Glass Co., Ltd. Surflon S
-112 and the like.

The preferred range of use of these surfactants of the present invention is such that the active ingredient is 0.05 to 10% by weight of the photosensitive composition, and
1-2% by weight is particularly preferred. 0.05% by weight of surfactant
If it is less than the above range, the effects of the present invention are not sufficiently exerted, and if it is more than 10% by weight, printing performance such as inking property and printing durability is adversely affected.

The photosensitive composition used in the present invention may be one whose solubility or swelling property in a developer changes before and after exposure, and for example, -CH = is present in the main chain or side chain in the molecule.
Polyester having a photo-crosslinkable group such as CHCO- group, one composed of a photosensitive resin such as polycarbonate or polysulfonate, one containing an o-quinonediazite compound, one containing an azide compound and an organic polymer carrier, diazo Examples thereof include those containing a compound and an organic polymer binder, addition-polymerizable unsaturated compounds, photosensitive compositions comprising a photopolymerization initiator and an organic polymer binder, and among these, diazo compounds and organic polymer binders. A photosensitive composition containing is particularly preferable. These photosensitive compositions are dissolved in a suitable solvent and coated on a support so that the coating amount after drying is 0.1 to 5 g / m ² .

The support used in the present invention is an aluminum support. The aluminum support is preferably subjected to surface treatment such as graining treatment, anodic oxidation treatment, immersion treatment in an aqueous solution of sodium silicate, potassium fluorozirconate, phosphate or the like. Also, U.S. Pat.No. 2,714,06
As described in No. 6, aluminum plate that has been grained and then immersed in an aqueous sodium silicate solution, as described in U.S. Pat.No. 3,181,461, after anodizing treatment. Those obtained by sequentially performing two or more kinds of surface treatments such as an aluminum plate immersed in an aqueous solution of an alkali metal silicate are also suitably used.

As a plate-making method for producing a lithographic printing plate from the photosensitive lithographic printing plate of the present invention, a conventionally used method can be used as it is. That is, exposure through a transparent original having a line image and / or a halftone image and then processing with a developing solution removes the photosensitive layer in the non-image area. A mercury lamp, a xenon lamp, a chemical lamp, a metal halide lamp, a strobe, etc. are used as a suitable light source used at the time of exposure. As the developing solution, an appropriate one may be used according to the composition of the photosensitive layer.For example, for a photosensitive layer composed of a diazo compound and an organic polymer binder, U.S. Pat.Nos. 3,475,171 and 3,669,660, 4th,
An aqueous alkaline developer described in, for example, No. 186,006 is used.

<Example> Hereinafter, the present invention will be described in detail based on examples,
This does not limit the embodiments of the present invention. The percentages in the examples are% by weight unless otherwise specified.

Example 1 An aluminum plate having a thickness of 0.3 mm was immersed in a 7% aqueous solution of sodium triphosphate (solution temperature 60 ° C.) for 3 minutes for degreasing,
After washing with water, while pouring the water in which the pumice was suspended on the surface, it was rubbed with a nylon brush to make grain. Then washed with water, and immersed for 30 to 60 seconds in a 5% aqueous solution of sodium silicate _{(SiO 2 / Na 2 O =} 3.1~3.3 ( molar ratio)) (liquid temperature 70 ° C.). Then, it was washed thoroughly with water and dried.

A photosensitive solution (I) having the following composition was applied to this aluminum plate and dried to obtain a photosensitive lithographic printing plate A.

Photosensitive liquid (I) 2-hydroxyethyl methacrylate copolymer (I)
(The one described in Example 1 in U.S. Pat. No. 4,123,276.) 5.00 g of 2-methoxy-4-hydroxy-5-benzoylbenzene, a condensate of p-diazodiphenylamine and paraformaldehyde. Sulfonate: 0.50g "Oil Blue # 603" (blue dye from Orient Chemical Industry Co., Ltd.) 0.10g Phosphorous acid: 0.05g 3M FC-161: 0.05g 2-methoxyethanol ... 100 g The dry coating amount of the photosensitive layer was 2.5 g / m ² .

For comparison, a photosensitive solution obtained by removing the surfactant FC-161 from the photosensitive solution (I) was applied and dried in the same manner as above to obtain a photosensitive lithographic printing plate (a).

The photosensitive lithographic printing plates A and (a) thus obtained were stacked 1000 sheets each without interposing interleaving paper, left at a temperature of 45 ° C for 7 days under a pressure of 300 kg / cm ² , and then Fuji Photo When a high-speed plate-making device FNR401 type made by Film Co., Ltd. was used to make a plate, the photosensitive lithographic printing plate (a) had a surface of the photosensitive layer and a back surface of the plates stacked thereon which were in contact with it. Although it was impossible to perform automatic plate making, the photosensitive planographic printing plate A could be automatically made without any problems. In addition, the printing performance of the lithographic printing plate obtained by developing these samples with a developer having the composition shown below hardly changed.

Developer solution composition Benzyl alcohol 30 g Triethanolamine 10 g Sodium tert-butylnaphthalene sulfonate 10 g Sodium sulfite 2 g Water 1000 g Example 2 An aluminum plate was immersed in a 20% sodium phosphate aqueous solution for degreasing and electrolytic etching, and then sulfuric acid. The solution was anodized in the solution, and then sealed with an aqueous solution of sodium metasilicate.

A photosensitive solution (II) having the following composition was applied to the aluminum plate so that the dry weight was 2 g / m ^2, and a photosensitive layer was formed to obtain a photosensitive lithographic printing plate B.

Photosensitive liquid (II) N- (4-hydroxyphenyl) methacrylamide / 2-
Hydroxyethyl methacrylate / acrylonitrile /
Ethyl methacrylate / methacrylic acid (= 15: 5: 30: 43: 7
Molar ratio) Copolymer (average molecular weight 60,000) …… 5.0 g Hexafluorophosphate of condensate of 4-diazodiphenylamine and formaldehyde …… 0.5 g Malic acid …… 0.05 g Victoria Pueble-BOH (Hodogaya Chemical Co., Ltd.) 0.1 g Dainippon Ink Co., Ltd. Megafac F-191 …… 0.05 g 2-methoxyethanol ··· 100 g For comparison, the photosensitive solution (II) was used to add surfactant F A photosensitive solution except for -191 was applied and dried in the same manner as above to obtain a photosensitive lithographic printing plate (b).

When these samples were tested in the same manner as in Example 1, the photosensitive lithographic printing plate (b) could not be automatically plate-made because the plates were stuck to each other, whereas the photosensitive lithographic printing plate B was automatically printed without any problem. I made the plate. The printing performance of the lithographic printing plate obtained by developing these was almost unchanged.

Examples 3 to 4 Surfactant S-112 manufactured by Asahi Glass Co., Ltd. was used instead of the surfactant FC-161 of Example 1 to prepare a photosensitive lithographic printing plate C, and a surfactant having the following structure was used to form a photosensitive composition. A planographic printing plate D was obtained.

CHF ₂ (CF ₂ ) ₃ CH ₂ OPO (ONa) ₂ These photosensitive lithographic printing plates were tested in the same manner as in Example 1, and as a result, automatic platemaking could be performed without any problems.

Example 5 An aluminum plate having a thickness of 0.3 mm was immersed in a 7% aqueous solution of sodium triphosphate (solution temperature 60 ° C.) for 3 minutes for degreasing,
After washing with water, while pouring the water in which the pumice was suspended on the surface, it was rubbed with a nylon brush to make grain. Then washed with water, and immersed for 30 to 60 seconds in a 5% aqueous solution of sodium silicate _{(SiO 2 / Na 2 O =} 3.1~3.3 ( molar ratio)) (liquid temperature 70 ° C.). Then, it was washed thoroughly with water and dried.

To this aluminum plate, apply a photosensitive solution having the following composition,
It was dried to obtain a photosensitive lithographic printing plate.

Photosensitive liquid 2-hydroxyethyl methacrylate copolymer (I)
(Described in Example 1 in U.S. Pat. No. 4,123,276.) ... 5.00 g 2-methoxy-4-hydroxy-5-benzoylbenzenesulfonic acid, a condensate of p-diazodiphenylamine and paraformaldehyde. Salt …… 0.50g “Oil Blue # 603” (Blue dye from Orient Chemical Industry Co., Ltd.) …… 0.10g Phosphorous acid …… 0.05g 3M FC-430 …… 0.10g Table 1 Surfactant ...... 0.05 g 2-methoxyethanol ...... 100 g The dry coating amount of the photosensitive layer was 2.5 g / m ² .

The photosensitive lithographic printing plates thus obtained were stacked one by one without sandwiching interleaving paper, and under pressure of 300 kg / cm ² , 45
After leaving it in a place of ℃ for 7 days, Fuji Photo Film Co., Ltd.
Plate making was carried out with high speed plate making equipment FNR401 type.

At this time, the surface of the photosensitive layer and the back surface of the plate stacked on it contacted with each other and the automatic plate making could not be done ×, and the one that could be automatically made without any problem was marked as ○. The results are shown in Table 1.

In addition, the printing performance of the lithographic printing plate obtained by developing these samples with a developer having the composition shown below hardly changed.

Developer composition Benzyl alcohol 30g Triethanolamine 10g Sodium tert-butylnaphthalenesulfonate 10g Sodium sulfite 2g Water 1000g The above results show a specific effect that only the fluorosurfactant having both the perfluoroalkyl group and the substituent containing a phosphorus atom of the present invention has no sticking and the automatic plate making suitability of the PS plate is improved. Clearly shows that.

<Effects of the Invention> The photosensitive lithographic printing plate of the present invention can be stacked at a temperature of room temperature or higher without sandwiching interleaving paper and stored for a long time under pressure,
Plates do not stick to each other, and therefore automatic plate making is possible, and workability and handling are excellent.

Claims (1)

[Claims] 1. A photosensitive lithographic printing plate having a photosensitive composition layer provided on an aluminum support, wherein at least a part of the photosensitive composition layer is exposed on the surface. 2. The photosensitive lithographic printing plate as described in the above item 1, wherein the photosensitive composition layer contains a surfactant having a substituent containing a perfluoroalkyl group and a phosphorus atom.