JPS5971054A - Photosensitive lithographic printing plate - Google Patents

Abstract

PURPOSE:To prevent accumulation of insoluble matter in a washing-out liquid by using a specific copolymer as a resin to be dispersed and incorporated as fine particles into the adjacent hydrophilic colloid on a nonsilver photosensitive layer. CONSTITUTION:A copolymer contg. A, the repetitive unit derived from a monomer selected from acrylic acid and methacrylic acid and B, the repetitive unit derived from a monomer selected from aralkyl acrylate and aralkyl methacrylate is dispersed and incorporated as fine particles into a hydrophilic colloid layer provided adjacently on a nonsilver photosensitive layer (a negative type photosensitive silver halide emulsion layer is directly formed on the nonsilver photosensitive layer. Said emulsion layer in such a case and an intermediate layer if said emulsion layer is formed, via said intermediate layer, on the nonsilver photosensitive layer).

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a photosensitive lithographic printing plate in which a negative photosensitive silver halide emulsion layer is provided on a non-silver photosensitive layer.

U.S. Patent No. G, 26. The specification describes that a non-silver photosensitive layer and a negative or directly positive photosensitive silver halide emulsion layer are formed on a support having a hydrophilic surface such as an aluminum plate. a hydrophilic colo-f layer (
This layer may be the photosensitive silver halide emulsion layer described above. ) discloses a photosensitive lithographic printing plate in which a water-insoluble lipophilic resin is substantially dispersed in the form of fine particles. Preferred specific examples of the lipophilic resin include phenolic resin and hydroxystyrene. Resins containing phenolic hydroxyl groups such as homopolymers or copolymers are mentioned.

The plate-making method using this photosensitive lithographic printing plate basically involves exposing a photosensitive silver halide emulsion layer to light, developing it to form a copper surface (8), fixing it if necessary, and then Using this silver image as a mask image, the entire surface is exposed to light that the non-silver photosensitive layer is sensitive to, the exposed and developed photosensitive silver balogenide emulsion layer is removed with a washing solution, and then the non-silver photosensitive layer is developed. It consists of It has been newly discovered that when a large quantity of photosensitive lithographic printing plates are processed for several weeks to several months by performing such a plate-making process using an automatic processor, several defects occur. To explain more specifically, the first
The disadvantage of this method is that insoluble matter accumulates in the washout solution used to remove the photosensitive silver halide emulsion layer, aggregates, and becomes scum, which stains the conveyance roller and interferes with the subsequent plate-making process. Ta. Second, the above-mentioned agglomerates adhered to the plate, resulting in a lithographic printing plate with spot-like defects.Thirdly, the developer of the non-silver photosensitive layer was exhausted, causing background stains. In the third case, continuous processing over a long period of time tended to slightly reduce the ink receptivity of the image.

As a result of various studies to solve the above-mentioned problems, the present inventors have discovered that a resin that is dispersed and contained in the form of fine particles in a hydrophilic colloid provided on (and adjacent to) the non-silver photosensitive layer. (A) repeating units derived from at least seven monomers selected from acrylic acid and methacrylic acid; and (B) repeating units derived from at least seven monomers selected from aralkyl acrylates and aralkyl methacrylates. It has been found that by using a copolymer containing units, the above-mentioned drawbacks can be overcome.

Hereinafter, the constituent elements of the photosensitive lithographic printing plate of the present invention will be explained in detail.

As the support having a hydrophilic surface used in the present invention, any support used as a support for lithographic printing plates can be used. Details of such supports are described in US Pat. No. 1,2g and '602.

As a non-silver photosensitive layer that can form a lipophilic image and is provided on the support as described above, a photosensitive lithographic printing plate (
It is also called Pre-8 sensitized plate and is abbreviated as 28th edition. ) includes a photosensitive layer suitably used in the above-mentioned "oleophilic image", where the term "oleophilic" means repelling dampening water used during printing and accepting oil-based ink. . The composition constituting such a photosensitive layer includes a composition made of diazo resin,
- A composition comprising a quinonediazide compound, a composition comprising a photosensitive azide compound, a photopolymerizable composition comprising an addition polymerizable unsaturated compound and a polymeric compound as a binder such as a photopolymerization initiator, and the main chain of the polymer 1 or Typical examples include compositions made of polymer compounds containing -CH═CH-C- groups in their side chains, and among these, compositions made of 0-quinonediazide compounds are particularly preferred. Details of these compositions can be found in U.S. Patent No. 47. ．． 26J', t09 specification. The non-silver photosensitive layer is θ.

/~ty/m2.

The negative photosensitive silver halide emulsion used in the present invention is described in US Pat.
What is described in lines 32 to 4th column is applicable. In particular, silver chlorobromide, silver iodobromide, and silver iodochlorobromide emulsions having an average grain size of O0θ/μ to about iμ are used, and these grains are subjected to, for example, sulfur sensitization, reduction sensitization, Ir, Rh, P
Chemical sensitization, such as sensitization with a noble metal salt such as t, or spectral sensitization using a sensitizing dye can be performed.

The negative photosensitive silver halide emulsion layer is preferably provided directly on the above-mentioned non-silver photosensitive layer, but may be provided via an intermediate layer made of a hydrophilic colloid.

Hydrophilic colloids used in this case include polyvinylpyrrolidone, polyvinylimidazole, polyvinyl alcohol, polyacrylic acid amide, copolymers thereof, in particular gelatin or gelatin derivatives, such as US Pat. No. 2, A/47 .

Octopus No. 2,743. +3rd issue, same number 3゜//l
? , 7g No. 6, same No. 3. /3 pieces, 9 pieces! No. and Tokko Showa 3rd generation! No. 314, No. 412-e2! ;J■! Preferably, those listed in the No.

In the present invention, a hydrophilic colloid layer provided adjacent to a non-silver photosensitive layer (i.e., directly on the non-silver photosensitive layer (if a two-type photosensitive silver halide emulsion layer is provided, the emulsion layer In addition, in the case where a negative photosensitive silver halide emulsion layer is provided on the non-silver photosensitive layer via the above-mentioned intermediate layer, the intermediate layer) contains (A) at least seven seven-silicon compounds selected from acrylic acid and methacrylic acid. A copolymer containing a repeating unit derived from Zimmer and (B) a repeating unit derived from at least seven monomers selected from aralgyl acrylates and aralkyl methacrylates is finely ground (
It is dispersed and contained in the form of particles. As a result, not only the above-mentioned drawbacks do not occur, but also the hydrophilic coro-f layer firmly adheres to the lipophilic surface (in most cases, the water-repellent surface) of the non-silver photosensitive layer. Moreover, the hydrophilic colloid layer can be uniformly provided with a uniform thickness, and even more surprisingly, the lithographic printing plate obtained after platemaking has a &ij ('1
In addition to exhibiting excellent ink receptivity, it also has high printing durability.

Repeating unit (B) of the copolymer used in the present invention
Specific examples of aralkyl acrylates and aralkyl methacrylates include benzyl acrylate, benzyl methacrylate, pheo-thyl acrylate, pheo-thyl methacrylate, 3-phenylpropyl acrylate, and 3-phenylpropyl methacrylate. Repeating unit in the copolymer The content of (A) is suitably 70 to JO molar, more preferably!
, t~3 tamorti. Also, the molecular weight of the copolymer is approximately 1
A range of 0°θθθ to about /, θθθ, Oθθ is suitable.

The above copolymer is dispersed and contained as fine particles in a hydrophilic colloid layer provided on (two adjacent to) the non-silver photosensitive layer. The hydrophilic colloids are dissolved in an organic solvent under heavy weight and dispersed in an aqueous solution ('-dispersed) with the help of anionic surfactants such as sodium alkylbenzenesulfonates, taurine derivatives and funnel oil, during which tricresyl High boiling point plasticizers such as phosphate, dioctyl butyrate, and dodecyl succinate can be used together.

Preferably, the copolymer is dispersed in the hydrophilic colloid with a particle size of θ, oiμ to /θμ. Therefore, the amount used can be from about 0.7 parts by weight to about 20 parts by weight based on the photosensitive/% silver halide emulsion - 70 parts by weight of hydrophilic colloid, and is preferably (or 1 to 70 parts by weight, most preferably 1 to 1 part by weight.

In this way, the copolymer is dispersed and contained, and the hydrophilic colloid aqueous solution is coated and dried on the non-silver photosensitive layer.

It is advantageous to apply and dry by the method described in No. 6 Theta.

The method and process for making a lithographic printing plate using the photosensitive lithographic printing plate according to the present invention are as follows. Expose the image first, then
A latent image is formed on silver 110 in a photosensitive layer containing silver halide. Next;: No. 10 Silver Genide Current ($
Immediately after processing with a fixing solution, it is exposed to active light including ultraviolet rays. sex/
After removing the mJ layer, the silver halide layer is removed, followed by a second development process (a process in which only the J and image areas of the non-silver sensitive layer are dissolved and removed to expose the hydrophilic surface of the support, and the printing plate is formed. It is.

The specific (= preferable composition) of the developer used in the first development is described in detail in British Patent No. 20t9/l. It is preferable to use an aqueous solution of proteolytic enzymes, as described in 299.9/2.

The processing solution used for development requires a processing solution that selectively dissolves only the non-image areas of the non-silver photosensitive layer. For example, when the non-silver photosensitive layer is a layer consisting of an O-quinonediazide compound, the developer described in U.S. Pat. Aqueous solutions of alkali metal silicates such as sodium silicate are used.

Surface smoothing treatments such as gumming and inking, which are normally used in the plate-making process using 28 plates, can be used.

Already known processing liquid replenishment systems can also be used.

EXAMPLES The present invention will be explained in detail below with reference to Examples.

Note that unless otherwise specified, "person in charge" refers to the person in charge of weight.

Example 1 Mechanically grained according to the method of JP-A-Sho'It-33-77. 2S [An aluminum machine was immersed in a 2-stage sodium hydroxide aqueous solution maintained at 0°C for 1 minute to corrode a part of the surface. After washing with water, it was immersed in a sulfuric acid-chromic acid solution for about 7 minutes to expose the pure aluminum surface. 3θ0C
Immersed in sulfuric acid with Ωθ maintained at +2, DC voltage i, sV,
After anodizing for 2 minutes at a current density of 3 A/dm2, it was washed with water and dried. Next, a photosensitive solution with the following composition was coated on a roll coater so that the dry weight was about λ/m2.
A non-silver photosensitive layer was provided by continuous coating using a silica film.

Acetone-pyroga [J-Rin naphthoquinone-/, 2-diazide (2)-J--sulfonic acid ester (synthesis method is according to the method of U.S. Patent No. 3.3.!t, No. 70, Example/ ), 2. jt cresol-bormaldehyde resin! , θ2 methyl ethyl ketone 7! Tanklohexanone
Next, a photosensitive solution having the following composition was continuously coated so that the dry weight was approximately 7 m2, and the film was dried with hot air at a final temperature of //θ0C. This sample JK/
shall be.

Copolymer of benzyl methacrylate and methacrylic acid (benzyl methacrylate) 70wt% methacrylic acid 3
owt%) 727 dissolved in ethyl acetate/J"41f, gelatin 1 oz6 aqueous solution, 27 Tsukuda 73, an anionic surfactant dispersed as a dispersion medium to create an emulsion.
・・・・・・・・・ J'7θV negative-working silver halide emulsion (silver chlorobromide with a concentration of 30 moles of silver bromide, average grain size
...0.2μ, emulsion/Kf per lysericeratin 2,
Silver halide θ, Fj mole content)
....../θθor/, 3-diethyl-t-
[,2-(3-(3-nulfopropyl)benzoxazo-A-,2-ylidene)ethylidene]thiohydantoin sodium salt o, i0! y Methanol solution...
... 50ml Cu-hydroxy-6-methyl-/
+ j + Jar7-o, s% alkaline aqueous solution of chitrazaindene... 10 ml λ, 2% aqueous solution of kujiklo (1-g-hydroxy-5-) riazine... 3 ml the other benzyl methacrylate A photosensitive solution having the same composition as the above except that it contains a dispersion of a phenol formaldehyde resin instead of a dispersion of a copolymer of methacrylic acid and a copolymer of This sample was designated as A and 2.

Sample A/and Sample A2 were left at room temperature for one week, and then plate-made as follows. about//! The transparent negative film obtained by photographing the character print lines was exposed to 7θ seconds sample/and λ at 3 times magnification using an enlarger with a 30θ lux light source.

Next, the following processing was performed using a roller conveyance type automatic developing machine.

A developer (I) having the composition shown below was run at 32°C for 2θ seconds, and a fixer (I) shown below was run at xo'C for 70 seconds. Next is the ultraviolet exposure section consisting of three reflector-type mercury lamps/! It takes a few seconds to pass through, and at the washing part it is <10~as
Dip in 0c warm water, rub with a brush, pass through a squeeze roller, and develop in 3θ at 30°C with a developer with the following composition (...)
A lithographic printing plate was obtained by gumming for a second.

Composition of developer (1) Water 20θml
Metol 3. θ2 Sodium sulfite...pt, θ2 Hydroquinone.../2. θ2 Sodium carbonate (/
water salt)... ♂o, oy potassium bromide
, add 2f water/l
This stock solution is diluted (/:, 2) with water and used.

Developer (If) JI8/No. Sodium silicate... 100fl Sodium metasilicate... SOt pure water
.../l! ? θ0m1J fixer (1) Water 700
ml ammonium thiosulfate...2.24
tf Sodium sulfite θ1 Add water to make /l.

This process was repeated for sample A/, and while replenishing each processing solution, development processing was carried out at θm2 per liter of mother liquor. The treated plates were printed using a printing press, and all of these samples were printed with 5 sheets, yielding about 70,000 copies of good quality prints.

Moreover, no stains such as adhesion of residue were observed in the automatic developing machine after processing at 20 m2/l.

Next, after cleaning each tank of the automatic developing machine and charging a new processing solution, sample/I62 was exposed and the same development process (8) was repeated, resulting in a development process of 20 m2 per liter of mother liquor.

Washing section of automatic developing machine after 10m2/l processing tff-
When the color was observed, a large number of black spot-like residues were observed.

Also, when treated with :zom2/l, there is a diameter of 0 on the printing plate,
．． Several spot-like debris of 1 mm to θ, j mm were attached. When this printing plate was printed using a printing press, 30 copies were required.

Claims (1)

[Claims] A support having a hydrophilic surface, which has a non-silver photosensitive layer and a negative photosensitive silver halide emulsion layer capable of forming a lipophilic image in this order, and which is provided adjacent to the non-silver photosensitive layer. In a photosensitive lithographic printing plate comprising fine particulate resin dispersed in a sexual colloid layer, the resin contains (A) at least 7 acrylic acids selected from acrylic acid and methacrylic acid.
and (B) a repeating unit derived from at least seven monomers selected from aralkyl acrylates and aralkyl methacrylates. .