JPH02123361A - Photosensitive planographic printing plate - Google Patents

Abstract

PURPOSE:To improve sensitivity and printing resistance by providing a photosen sitive layer consisting of a negative effect diazo resin layer as an intermediate adhesive layer and a polymer which has a maleimide group in the side chain and allows photo-network formation onto a base having a hydrophilic surface. CONSTITUTION:The negative effect diazo resin layer is provided between the base subjected to a hydrophilicity impartation treatment and the photosensitive layer consisting of the polymer which has the maleimide group in the side chain and allows the photo-network formation. The resin layer is then subjected to image exposing by using a light source of ample UV rays and is processed by a processing soln. to remove the unexposed part of the photosensitive layer; finally a gum liquid is applied on the resin layer to form the planographic printing plate. The planographic printing plate having the excellent printing performance while maintaining the excellent sensitivity of the polymer which has the maleimide group in the side chain and allows the photo-network forma tion is obtd. in this way.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a photosensitive lithographic printing plate.

More specifically, the present invention relates to a photosensitive lithographic printing plate provided with a photosensitive layer made of a photoreticulable polymer that has improved adhesion to a support having a hydrophilic surface.

[Conventional technology]

Photocrosslinkable materials that crosslink through cycloaddition reactions are well known, and many of these are used as main components of photosensitive compositions used in the production of photosensitive lithographic printing plates and the like.

Among these crosslinked materials, photocrosslinkable polymers with maleimide groups in their side chains are highly sensitive and useful as photoresists, but they have the problem of poor adhesion to supports and other layers. It has not been put into practical use.

If the adhesion is poor, the image may peel off or be damaged by brushes during development, making it impossible to obtain sufficient printing durability. Furthermore, at low exposure times, this tendency is noticeable, resulting in lower sensitivity.

An attempt to improve adhesiveness was made in JP-A-62-785.
44, an attempt was made to add a negative-acting diazo resin to the photosensitive layer, and as described in JP-A-62-85255, an anodized film formed on an aluminum support was used. Attempts are known to widen the bore and obtain adhesive strength through a physical anchor effect.

However, addition of the diazo resin to the photosensitive layer has problems such as lowering the sensitivity and impairing the stability of the pigment (coloring material) in the state of a coating solution. Furthermore, the method of enhancing the anchoring effect on the surface of the support has the disadvantage that non-image areas tend to receive ink during printing, resulting in printing stains and smudges.

[Problem to be solved by the invention]

Therefore, it is an object of the present invention to provide a photosensitive lithographic printing plate that maintains the excellent sensitivity of a photoreticulable polymer having a maleimide group in its side chain and provides a lithographic printing plate with excellent printing performance. do.

[Means to solve the problem]

The present invention proposes that the above object can be achieved by providing a negative working diazo resin layer between a hydrophilic support and a photosensitive layer comprising a photoreticulable polymer having a maleimide group in its side chain. This was done based on knowledge.

That is, the present invention provides, on a support having a hydrophilic surface,
This is a photosensitive lithographic printing plate characterized by being provided with a negative working diazo resin layer as an intermediate adhesive layer and a photosensitive layer containing a photoreticulable polymer having a maleimide group in its side chain.

The photoreticulable polymer having a maleimide group in the side chain used in the present invention 1 is described in Japanese Patent Application Laid-Open No. 52-988 (corresponding U.S. Pat. No. 4,079,041), German Patent No. 2,
No. 626.769, European Patent No. 21.019
No. 3.552 specification, European Patent No. 3.552 specification and D.
・Angebandute Macromolecule φ Chemie (D
ie Angewandte Makromoleku
16 of lareChemie) 115 (1983)
The following general formula (I) described on pages 3 to 181 (
where R and R1 each independently represent an alkyl group having up to 4 carbon atoms, or R and R3 may together form a 5- or 6-membered carbocycle) Polymers having a maleimide group in the side chain represented by
No. 49-128993, No. 50-5376, No. 50
-5377, 50-5379, 50-5378
No. 50-5380, No. 53-5298, No. 5'
No. 3-5299, No. 53-5300, No. 50-501
No. 07, No. 51-47940, No. 52-13907, No. 50-45076, No. 52-121700, No. 50-10884, No. 50-45087, No. 2,349.948, No. 2.616,276, represented by the following general formula (II) (wherein R2 represents an aromatic group and R8 represents a hydrogen atom, a halogen atom, an alkyl group, or a cyano group) Examples include polymers having a maleimide group in a side chain. The average molecular weight of these polymers is 10
00 or more, preferably 30,000 to 40,000. Furthermore, these polymers have an average of two or more maleimide groups per molecule in their side chains. Among these polymers having a maleimide group in a side chain, a polymer having an acid group in particular is advantageous from the viewpoint of preventing pollution since alkaline water can be used during development. The acid value of the maleimide group polymer having an acid group is preferably in the range of 20 to 250, more preferably in the range of 50 to 150. In particular, among the polymers with these acid values, D-
Angebandute Macromolecule Chemie (Di
e Angev+andte! , Iakromole
kulareChemie) 128 (1984
) as described on pages 71 to 91 of N-(2-
Copolymers of (methacryloyloxy)ethyl)-2,3-dimethylmaleimide and methacrylic acid or acrylic acid are useful. Furthermore, during the synthesis of this copolymer, a third
By copolymerizing the component vinyl monomers, it is possible to easily synthesize a multi-component copolymer depending on the purpose. For example, flexibility can be imparted to the copolymer by using, as the third component vinyl monomer, an alkyl methacrylate or alkyl acrylate whose homopolymer has a glass transition point below room temperature.

The photosensitizer used as necessary in the present invention is 30
Preference is given to triplet sensitizers having an absorption maximum that allows practically sufficient light absorption in the range of 0 nm or more. Examples of such sensitizers include thioxane, thioxanthone derivatives, such as 2-chlorothioxatone, 2-isopropylthioxanthone, dimethylthioxanthone, methylthioxanthone-1-ethylcarboxylate, and 5-nitroacenaphthene. I can do it. In addition, JP-A-59-2
Electron-accepting compounds such as 1,2-dicyanobenzene and chloraninope-2,3-dichloro-5,6-dicyanobenzenone described in Japanese Patent No. 06425 are also effective. The amount of these sensitizers added is 1 to 20% by weight, more preferably 3 to 10% by weight of the total composition.

In addition to the above, it is preferable to further add an antioxidant to the photosensitive layer, such as di-t-butyl-p-cresol,
Benzoquinone, 4,4'-thiobis(3-methyl-6-
t-butylphenol), 2-mercaptobenzimidazole, etc. are useful, and in some cases, dyes or pigments are used for the purpose of coloring the photosensitive layer, and photoacid generators (e.g., triazine-based, oxazole-based Torino) are useful as printing agents.
romethyl compound), a pH indicator, an azide compound, a leuco dye, a spiropyran compound, etc.

The photosensitive composition as described above is prepared in a suitable solvent such as, for example, 2-methoxyethanol, 2-methoxyethyl acetate, propylene glycol monomethyl ether, 3-methoxypropanol, 3-methoxypropyl acetate, methyl ethyl ketone, ethylene dichloride, etc. They are dissolved in a mixed solvent alone or in an appropriate combination and coated on a support. The amount of coverage is approximately 0.0% by weight after drying.
A range of 1 g/11' to about 10 g/m2 is suitable, more preferably 0.5 to 5 g/m2.

The support having a hydrophilic surface used in the present invention is
It is desirable that it be a dimensionally stable plate-like object. Such dimensionally stable plate-like materials include those conventionally used as supports for printed matter, and they can be suitably used in the present invention.

Such supports include paper, paper laminated with plastics (eg, polyethylene, polypropylene, polystyrene, etc.), plates of metals such as aluminum (including aluminum alloys), zinc, copper, etc., cellulose diacetate, triacetate, etc. cellulose acetate, cellulose propionate,
Films of plastics such as cellulose acetate, cellulose acetate butyrate, cellulose nitrate, polyethylene terephthalate, polyethylene, polystyrene, polypropylene, polycarbonate, polyvinyl acetal, etc., and paper or plastic films laminated or vapor-deposited with the above metals are included. Among these supports, aluminum plates are preferred because they are extremely dimensionally stable, inexpensive, and have particularly good adhesion to the composition of the present invention. In addition, the special public official 1832-1832
Also preferred is a composite sheet in which an aluminum sheet is bonded onto a polyethylene terephthalate film as described in Japanese Patent No. 7.

Further, in the case of a support made of metal, particularly aluminum, it is preferable that the support be subjected to surface treatment such as graining treatment or anodizing treatment.

Furthermore, in order to increase the hydrophilicity of the surface, it is preferable to perform an immersion treatment in an aqueous solution of sodium silicate, potassium fluorozirconate, phosphate, or the like.

As described in U.S. Patent No. 2,714,066, an aluminum plate is grained and then immersed in an aqueous sodium silicate solution; as described in Japanese Patent Publication No. 47-5125; A material obtained by anodizing and then immersing in an aqueous solution of an alkali metal silicate is also suitably used.

Also effective is silicate electrodeposition as described in U.S. Pat. No. 3,658,662.

Furthermore, Japanese Patent Publication No. 46-27481, Japanese Patent Publication No. 52-5
Also useful is a surface treatment that combines a support coated with electrolytic grains with the above-mentioned anodic oxidation treatment and sodium silicate treatment as disclosed in JP-A-8602 and JP-A-52-30503.

Furthermore, it is also preferable to use brush grain, electrolytic grain, anodic oxidation treatment, and sodium silicate treatment as disclosed in JP-A-56-28893. Furthermore, after these treatments, it is also suitable to apply an undercoat with a water-soluble resin such as polyvinylphosphonic acid, a polymer or copolymer having a sulfonic acid group in the side chain, polyacrylic acid, or the like.

These hydrophilic treatments are performed not only to make the surface of the support hydrophilic, but also to prevent harmful reactions with the photosensitive composition provided thereon, and to improve the adhesion with the photosensitive layer. This is done for the purpose of improving.

It is something.

Various known negative-acting diazo resins can be used as the intermediate adhesive layer. Such diazo resins include 4-diazo-diphenylamine and 1-diazo-diphenylamine.
4-N,N-dimethylaminobenzene, 1"A7'
4 N, N-diethylaminobenzene, 1-diazo-4-N-ethyl-N-hydroxyethylaminobenzene, l-diazo-4-N-methyl-N-hydroxyethylaminebenzene, 1-diazo-2,5-jethoxy -4-Benzoylaminobenzene, l-diazo-4-
N-benzylaminobenzene, 1''azo-4-N
, N-dimethylaminobenzene, 1-diazo-4-morpholinobenzene, 1-diazo-2゜5-dimethoxy-4-p-tolylmercaptobenzene, 1-diazo-2
-ethoxy-4-N,N-dimethylaminobenzene, p
-Diazo-dimethylaniline, 1-diazo-2,5-dibutoxy-4-morpholinobenzene, l'''Azo2,5-jetoxy-4-morpholinobenzene, 1
-Diazo-2,5-dimethoxy-4-morpholinobenzene, 1-diazo-2,5-jethoxy-4-morpholinobenzene, ■-Diazo2. 5-jetoxy-4
-p-tolylmercaptobenzene, 1-diazo-3-nitoxy-4-N-methyl-N-benzylaminobenzene, 1-diazo-3-chloro 4-N,N-diethylaminobenzene, l-diazo-3- Methyl-4-pyrrolidinobenzene, 1-diazo-2-chloro-4-N, N-dimethylamino-5-methoxybenzene, 1-diazo-3-
Methoxy-4-pyrrolidinobenzene, 3-methoxy-4
- diazo monomers such as diazodiphenylamine, 3-ethoxy-4-diazodiphenylamine, 3-(n-propoxy)-4-diazodiphenylamine, 3-impropoxy-4-diazodiphenylamine, formaldehyde, acetaldehyde, propionaldehyde, butyl A condensing agent such as acetaldehyde, isobutyraldehyde, or benzaldehyde in a molar ratio of 1
:1-1:0.5, preferably l:o, 8-1:0.6
An example is a reaction product of a condensate obtained by condensing this by a conventional method and an anion.

Examples of anions include tetrafluoroboric acid, hexafluorophosphoric acid, triisopropylnaphthalenesulfonic acid, 5-nitroortho-toluenesulfonic acid, 5-sulfosalicylic acid, 2,
5-dimethylbenzenesulfone M, 2.4.6-)dimethylbenzenesulfocitro-nitrobenzenesulfone!
, 3-chlorobenzenesulfonic acid, 3-bromobenzenesulfonic acid, 2-fluorocaprylnaphthalenesulfonic acid, dodecylbenzenesulfonic acid, 1-naphthol-5
-sulfonic acid, 2-methoxy-4-hydroxy-5-benzoyl-benzenesulfonic acid, and para-toluenesulfonic acid Y22nCβ2. Among these, alkyl aromatic sulfonic acids such as hexafluorophosphoric acid, triisopropylnaphthalenesulfonic acid and 2,5-dimethylbenzenesulfonic acid are particularly suitable.

The thickness of this diazo resin layer can be varied over a wide range;
It must be thick enough to undergo a uniform bond-forming reaction with the upper photosensitive layer when exposed to light.

Usually, a dry solid coating rate of 1 to 50 mg/m2 is good.
5 to 20 mg/m' is particularly good.

Furthermore, phosphoric acid, phosphorous acid, tartaric acid, citric acid, malic acid, dipicolinic acid, polynuclear aromatic sulfonic acid and its salts, sulfosalicylic acid, etc. are added as stabilizers for the diazo resin in the diazo resin layer and photosensitive layer. It can be added as needed.

The photosensitive lithographic printing plate of the present invention is imagewise exposed using a light source rich in ultraviolet rays such as a metal halide lamp or a high-pressure mercury lamp, and treated with a developer to remove unexposed areas of the photosensitive layer.
Finally, a lithographic printing plate is prepared by applying a gum liquid.

In order to further increase stiffness resistance, post-exposure may be performed after development. Preferred as the developer are benzyl alcohol,
It is an alkaline aqueous solution containing a small amount of an organic solvent such as 2-phenoxyethanol or 2-butoxyshetanol, for example, U.S. Patent Nos. 3,475.17-1 and 3.6.
Examples include those described in No. 15,480. Furthermore, JP-A No. 50-26601, JP-A No. 56-
The developers described in Patent Publications No. 39464 and No. 56-42860 are also excellent as developers for the photosensitive lithographic printing plate of the present invention.

〔Effect of the invention〕

The photosensitive lithographic printing plate of the present invention has high sensitivity and provides a lithographic printing plate with excellent printing durability.

〔Example〕

Hereinafter, it will be explained in more detail based on examples.

Example 1 The surface of an aluminum plate having a thickness of 0.30 +++ m was grained using a nylon brush and a water suspension of 400 mesh pumice stone, and then thoroughly washed with water.

After etching by immersing in 10% sodium hydroxide at 70°C for 60 seconds, washing with running water and 20% HNO.

Neutralized and washed with water. This is VA = 12.7 v
Electrolytic surface roughening treatment was carried out in a 1% nitric acid aqueous solution using a sinusoidal alternating waveform current under the conditions of 160 corons/dm" of anode special electricity. When the surface roughness was measured, 0
．． It was 6 μ (expressed as Ra). Continuing to 30% H
After immersing in 2SO, aqueous solution and desmutting for 2 minutes at 55°C, 20%) I2SO, in aqueous solution, current density 2
A/dm" and anodized for 2 minutes to a thickness of 2.7 g/m2. Thereafter, it was immersed in a 2.5% aqueous solution of sodium silicate at 70° C. for 1 minute, washed with water, and dried.

Next, the following diazo resin liquid was prepared.

This liquid was applied onto the previous substrate using a spin coater so that the weight after drying would be IOfl1g/[11''.

Then, it was dried at 80° C. for 1 minute.

Next, the following photosensitive composition (2) was prepared.

Photosensitive composition ■ Methyl methacrylate/N(2-(meccryloyloxy)ethyl E-2.3-dimethylmaleimide/methacrylic acid = 15/65/20 (weight ratio) copolymer
5g・Sensitizer represented by the following structural formula・Propylene glycol monomethyl ether 0g・Methyl ethyl ketone 50g・Megafac F-177 (manufactured by Dainippon Ink, fluorine-based nonionic surfactant) 0.03g・Copper phthalocyanine pigment (CI) Pigment Blue 15) 10% plasticizer dispersion 1.0 g of this photosensitive composition was applied onto the substrate provided with the diazo resin using a spin coater, and the weight after drying was 1.5 g/m2. It was applied so that

Then, it was dried at 80° C. for 2 minutes.

The printing plate thus obtained is referred to as A.

(Comparative Example) On the same substrate as in Example 1, without providing a diazo resin layer, this photosensitive liquid was applied to a dry weight of 1.5 g/m 2 and dried to obtain printing plate B.

A step wedge (density step of 0.15
, 15 density steps) and exposed for 10 counts using a printer (2K''vV metal halide lamp) manufactured by Nuark, USA. After exposure, development was performed at 25° C. for 1 minute with the following developer to obtain a printing plate.

Developer solution Benzyl alcohol 4.5g Isopropylnaphthalene sulfonic acid 38% aqueous solution of IJium salt 4.5g Triethanolamine 1.5g Monoethanolamine 0.1g Sodium sulfite 0.3g Pure water
100g (Results) Printing plate A of the present invention has a solid image and high sensitivity, but printing plate B has poor adhesion to the substrate, so not only is the sensitivity low, but the image area was slightly rubbed during development. It had countless scratches from time.

When these printing plates were attached to a Heidel SOR printing machine and printed, A was able to obtain 50,000 prints, but B
The number of copies printed was 1,000, and only samples with poor tone reproducibility were obtained because the details were missing, and friction occurred on the entire image after 10,000 copies were printed.

[Example 2] The following diazo resin liquid was applied to the same substrate as used in Example 1 and dried. The dry weight was adjusted to 10 mg/m2.

Next, the following photosensitive solution (2) was prepared.

Photosensitive liquid■ ON-[:2-(methacryloyloxyethyl]-2,
3-dimethylmaleimide/methacrylic acid = 85/15
(Weight ratio) Copolymer 5g ○ The following sensitizer ○ ○ Megafac F-177 (manufactured by Dainippon Ink, fluorine-based nonionic surfactant) 0.03g Copper phthalocyanine pigment (CI Pigment Blue 15) plasticizer 10 % dispersion 1.0g methyl ethyl ketone
50g○ Propylene glycol monomethyl ether 0g This photosensitive composition was applied to the substrate coated with the diazo resin using a spin coating machine, and the weight after drying was 1.5 g/
It was applied so that it became m2. This printing plate was designated as C.

(Comparative Example 2) A photosensitive solution (2) was prepared by adding 0.2 g of PFs salt, which is a composite of P-diazodiphenylamine and formaldehyde, to the photosensitive solution (H).

The substrate used in Example 1 was coated with diazo (without a sealing layer).
A photosensitive solution (■) was applied and dried. Dry weight is 1.5g/m”
Met. This printing plate was designated as D.

Furthermore, when this photosensitive solution (2) was left indoors overnight, pigment sedimentation was observed at the bottom.

(result) Similarly to Example 1, the results of exposure and development are shown.

It also shows the number of printed sheets obtained during printing.

The printing plate C of the present invention is more High sensitivity, High durability It showed stiffness.

or, Excellent stability of coating liquid there was.

Procedural amendment 1, indication of the case 1988 Patent Application No. 277-103 4, agent 5, date of amendment order 6, column 7 for detailed explanation of the invention in the specification to be amended, description of the contents of the amendment On page 7, line 19, "tojite thioxane" is corrected to "tojite thioxanthone."

Claims (1)

[Claims] A photosensitive material comprising a support having a hydrophilic surface, a negative working diazo resin layer as an intermediate adhesive layer, and a photosensitive layer having a photoreticulable polymer having a maleimide group in its side chain. Lithographic printing plate.