JPH0364058B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a developer for lithographic printing plate materials (offset PS plates) formed by coating the surface of an aluminum support with a photosensitive composition in advance, and particularly relates to a developer for negative type PS plates (offset PS plates). This relates to a developer for removing the non-image areas of both types of PS plates after exposure (the photosensitive composition is mainly composed of quinone diazide compounds) and positive type PS plates (the photosensitive composition is mainly composed of quinonediazide compounds). [Conventional technology] Almost all PS versions currently on the market are
For negative type PS plates, diazo compounds such as formaldehyde condensates of P-diazophenylamine, and for positive type PS plates, acrylic multi-component copolymers containing quinone diazide compounds and carboxylic acids for the purpose of strengthening image areas. It consists of a photosensitive composition consisting of a photosensitive composition and an aluminum plate whose surface has been imparted with hydrophilic properties. In the process of making lithographic printing plates using such PS plates, the extremely important role of the developer is to quickly dissolve and remove the photosensitive resin layer in the non-image area, and to remove the exposed aluminum surface by development. The purpose is not to reduce hydrophilicity, but rather to enhance it, while not impairing the lipophilicity of the resin layer in the image area cured by actinic rays. [Problems to be Solved by the Invention] However, promoting hydrophilization of non-image areas as a required role of the developer may conversely reduce the lipophilicity of image areas, and the development speed may be reduced. If you try to increase the image area, the image area will also be relatively eluted, causing problems with image reproducibility.
Various measures are required, and in reality, staining of the plate during printing and poor inkling at the start of printing are often caused by the developer. In this way, in consideration of the influence on the plate material, different developers are used for the negative type PS plate and the positive type PS plate, which have already been described. However, using two types of developing solutions differently in this way is complicated in the development work, and is uneconomical as it requires two developing machines to increase work efficiency. While conducting research on our company's offset PS plate developer, we discovered that it can be used for both negative type and positive type PS plates, and that it is perfect in terms of development speed and ability to maintain hydrophilicity of the aluminum surface in non-image areas. We have arrived at the invention of a new developer. [Means and effects for solving the problem] That is, the present invention solves the problem using the general formula R-O-CH ₂ CH ₂ OH
(In the formula, R represents a phenyl group or a benzyl group.) Anionic surfactants, hydroxides of alkali metals belonging to Group 1 A of the Periodic Table, silicic acids, hereinafter referred to as "specific ether compounds" The present invention provides a developer for a photosensitive lithographic printing plate, which is characterized by containing an alkaline substance consisting of three components: a salt and a tetrafolate. More specifically, the specific ether compound in the present invention is ethylene glycol monophenyl ether.

[Formula] and ethylene glycol monobenzyl ether

[Formula] These are organic solvents and are commercially available. Examples of anionic surfactants used in the present invention include fatty acid salts {(R ¹ COO) _o Mm} and alkylbenzene sulfonates.

[Formula] Alkyl sulfonate {(R ¹ −SO ₃ ) _o Mm}, α-olefin sulfonate, {

【formula】 Mm,

Mixture of [formula], etc.}, dialkyl sulfosuccinate

【formula】 α-Sulfonated fatty acid salt

[Formula] N-methyl-N-oleyl taurine

[Formula] Alkyl sulfate {R ¹ OSO ₃ ) _o Mm} Polyoxyethylene alkyl phenyl ether sulfate Alkyl phosphate

[Formula] Polyoxyethylene alkyl ether phosphate

[Formula] Polyoxyethylene alkyl phenyl ether phosphate Naphthalene sulfonate formaldehyde condensate naphthalene sulfonate

〔Example〕

The present invention will be explained in more detail below with reference to Examples. Example 1 Commercially available positive type PS plate (Ulstar PS) and negative type PS plate (Ulstar NS) manufactured by Nippon Seifuku Co., Ltd.
The positive and negative image films are layered on top of each other.
Exposure for 40 seconds from a distance of 1 m using a 4KW ultra-high pressure mercury lamp, and develop at room temperature (20℃) using a developer with the following composition.
After dipping for 20 seconds, the unexposed areas were removed by washing with water to obtain a lithographic printing plate. Ethylene glycol monophenyl ether 10g Sodium alkylnaphthalene sulfonate 60g Sodium hydroxide 5g Water glass (No. 3, solid content 50%) 5g Sodium tetraphorate 0.5g Water 919.5g This printing plate was printed on a Heidel KORD printing machine on high-quality paper. When printing was performed, more than 50,000 copies could be printed without any problems with both the lithographic printing plates obtained from the negative type PS plate and the positive type PS plate. In addition, each PS after the exposure using the above developer
The plate was developed at 20°C for 60 seconds using an automatic processing machine called Auto Processor 600E (manufactured by Fuji Photo Film Co., Ltd.), and the development processing capacity at that time was investigated ^.
That's all. Negative type with conventional developer
The limit was 10 m ² for the PS version and 3 m ² for the positive type PS version, but compared to these, the processing capacity was extremely high. Especially positive type PS
With regard to plates, the throughput was approximately five times greater, a dramatic effect unparalleled by commercially available positive type developers. Example 2 The development speed of the commercially available PS plate shown below was measured at room temperature (20°C) using the following commercially available developer and the developer of the present invention. As shown in Tables 1 and 2, the results showed that the development speed was comparable, and the commercially available
It showed excellent developability that can be applied to all PS plates.

[Table] The development speed in the table is as follows: Pour 100 ml of developer into a stainless steel vat with bottom dimensions of 15 x 18 cm, insert a PS plate (green plate) with dimensions of 10 x 10 cm, and immerse it every 10 seconds. The plate was taken out, washed with water, and the surface of the plate was wiped with protect ink, and the immersion time was measured when no stains were observed.

【table】

[Table] Example 3 100 ml of each developer of the present invention and commercially available developers was poured into the vat for measuring development speed used in Example 2, and then left at 40°C for 18 hours. Next, to the residue in each vat, water was added in an amount reduced by the above-mentioned standing to make 100 ml, and the developing speed was measured in the same manner as in Example 2 using these developing solutions. The results are shown in Tables 3 and 4, and in the case of the present invention, there was almost no deterioration in the developing effect due to leaving the developer.

【table】

[Table] Examples 4 to 18 Positive and negative image films were applied to the commercially available positive type PS plate (Ulster PS) and negative type PS plate (Ulster NS) manufactured by Nippon Foil Co., Ltd. used in Example 1, respectively. After exposure for 30 seconds from a distance of 1 m using a 4KW ultra-high pressure mercury lamp, a lithographic printing plate was obtained using the developer shown in Table 5 below.

【table】

〔Effect of the invention〕

Until now, there was no developer that could be commonly applied to PS plates from various companies, and there was
Since there was no developer that could be commonly applied to all plates,
Offset lithography printers have been forced to replace the developer depending on the use of the PS plate, but replacing the developer can easily cause various mistakes and the work itself is complicated. However, the developer according to the present invention exhibits good development effects on PS plates made by various companies, and also shows good development effects on both types of PS plates, negative type PS plates and positive type PS plates. The above problems can be solved because of this. Therefore, it can be said that the present invention has remarkable effects and has high industrial applicability.

Claims (1)

[Scope of Claims] 1. An ether compound represented by the general formula R-O-CH ₂ CH ₂ OH (wherein R represents a phenyl group or a benzyl group), an anionic surfactant, and a member of Group 1 of the Periodic Table. A developer for a photosensitive lithographic printing plate commonly used for negative-type PS plates and positive-type PS plates, characterized in that it contains an alkaline substance consisting of three components: an alkali metal hydroxide, a silicate, and a tetraphorate belonging to group A. 2. A developer for a photosensitive lithographic printing plate that can be used for negative-type PS plates and positive-type PS plates according to claim 1, wherein the anionic surfactant is an alkylnaphthalene sulfonate.