JP7394171B1 - Developer solution for untreated plates and method for producing developed untreated plates - Google Patents

Abstract

[Problem] The present invention provides an unprocessed plate that can be mounted on the plate cylinder of a printing press to develop image areas without performing on-press development processing (pre-printing work) by supplying dampening water and printing ink. The purpose of the present invention is to provide a developer for unprocessed plates that allows the development state to be checked, that is, to allow development processing to be performed before mounting on the plate cylinder of a printing press and without using dampening water or printing ink. do. [Solution] An unprocessed plate developer for developing an unprocessed plate, characterized by containing ethanol and at least one of an organic acid and a phosphoric acid compound. liquid. [Selection diagram] None

Description

The present invention relates to a developer for untreated plates used in offset printing.

CTP (computer-to-plate) printing plates, which make planographic printing plates based on digital signals from computer information, generally use a laser to directly expose the photosensitive material and use a developer to develop it. It is being carried out according to However, the disposal of waste liquid generated during development processing poses an environmental burden. Recently, there has been a strong demand in the market that emphasizes protection of the global environment, and improvements to printing plate making systems are also strongly desired.

Therefore, many methods have been proposed for making a lithographic printing plate without using a processing liquid in a development process or the like. These are called process-less printing plates because they do not undergo a development process using a liquid.This type of printing plate includes a type in which the image area or non-image area is removed by ablation using laser light, A type in which the image area is formed using an inkjet method, and a type in which the image area is formed using heat-fusible or thermoplastic particles have been proposed. This kind of processless printing plate (untreated plate) is made by attaching the exposed printing plate to the plate cylinder of a printing press and supplying dampening water and ink while rotating the plate cylinder. The development process is completed during the normal printing process by a method called on-press development that removes the image area.

However, the untreated plate has a problem in that it is difficult to visually manage and confirm the image area until it is mounted on the plate cylinder of the printing machine and subjected to development processing (pre-printing work).

In order to solve such problems, Patent Document 1 discloses a printing plate management system that is characterized in that when an unprocessed plate is used in a CTP device, visually visible plate information is directly added to the unprocessed plate. A method has been disclosed, and a method has been proposed in which visible version information can be directly added to an unprocessed version and can be visually confirmed.

However, the information on the unprocessed plate is printed on the back side of the printing plate, and the plate information is input into the printing machine on the other hand, and the information on the printing plate is read using a reading device, and the plate information input into the printing machine on the other hand. This is a printing plate management method for determining whether or not the printing plate matches the actual printing plate, and does not manage or confirm the actual development state (image area state) of the printing plate. Moreover, there is no mention or suggestion thereof.

In addition, in on-press development, printing ink is first supplied completely over the entire surface of the plate, so paper to which printing ink has been transferred during on-press development processing (also called waste paper, waste paper, etc.) must be discarded. Because dampening water is also supplied at the same time, the tackiness of the printing ink transferred from the plate to the blanket can be reduced with low-strength papers (especially newsprint, uncoated paper, lightly coated paper, etc.). (also called tuck) may cause the paper to wrap around the blanket and cause paper to break. For this reason, there is a need to carry out printing operations by loading a printing plate that has been manually developed onto a printing press without undergoing development processing on the printing press.

Patent Document 1 does not describe or suggest a developer or a developing method that allows manual development of the above-mentioned printing ink without using dampening water.

Japanese Patent Application Publication No. 2007-86564

Therefore, the present invention has been developed to develop an image area without performing on-press development processing (pre-printing work) by attaching an unprocessed plate to the plate cylinder of a printing press and supplying dampening water and printing ink. The purpose of the present invention is to provide a developer for unprocessed plates that allows the condition of the plate to be checked, that is, to develop the plate before it is installed on the plate cylinder of a printing press and without using dampening water or printing ink. .

As a result of extensive studies, the present inventors have found that the above object can be achieved by including ethanol and at least one of an organic acid and a phosphoric acid compound, and have completed the present invention.

That is, the present invention
(1) A developer for an untreated plate for developing an untreated plate,
Contains ethanol, methanol, and at least one of an organic acid and a phosphoric acid compound ,
A developing solution for unprocessed plates, characterized in that the content ratio of the ethanol and the methanol is ethanol/methanol = 99/1 to 50/50 ;
(2) The untreated product according to (1) , further containing at least one of isopropyl alcohol, normal propyl alcohol, normal butyl alcohol, isobutyl alcohol, sec-butyl alcohol, and tert-butyl alcohol. plate developer,
(3) The organic acid and phosphoric acid compound include formic acid, acetic acid, citric acid, lactic acid, malic acid, phthalic acid, benzoic acid, succinic acid, tartaric acid, oxalic acid, propionic acid , maleic acid , phosphoric acid, and phosphoric acid. The compound according to (1) or (2), characterized in that it contains at least one of acid, phosphinic acid, phytic acid, orthophosphoric acid, pyrophosphoric acid, tripolyphosphoric acid, tetrapolyphosphoric acid, metaphosphoric acid, and ultraphosphoric acid. developer for processing plates,
(4) preparing an unprocessed plate prior to development having an image area and a non-image area;
A step of bringing the developer for the untreated plate according to (1) or (2) into contact with the surface of the untreated plate before development;
A method for producing a developed untreated plate, the method comprising: developing an image area on the surface of the untreated plate;
(5) preparing an unprocessed plate before development having an image area and a non-image area;
A step of contacting the surface of the untreated plate before development with the developer for the untreated plate according to (3);
A method for producing a developed untreated plate, the method comprising: developing an image area on the surface of the untreated plate;
It is.

According to the present invention, it is possible to provide a developer for an unprocessed plate that can be developed without using dampening water or ink before being installed on the plate cylinder of a printing press. Moreover, the untreated plate produced using the developer has printability equivalent to that of conventional untreated plates.

EMBODIMENT OF THE INVENTION Hereinafter, the form for implementing this invention is demonstrated in detail. Note that this embodiment is only one mode for carrying out the present invention, and the present invention is not limited to this embodiment, and various modifications and embodiments may be made without departing from the gist of the present invention. It is possible.

The developing solution for unprocessed plates of the present invention preferably contains ethanol and at least one of an organic acid and a phosphoric acid compound.

The developing solution for unprocessed plates of the present invention preferably contains ethanol. The content of the ethanol is preferably 5 to 80% by mass, more preferably 15 to 60% by mass, and even more preferably 25 to 45% by mass, based on the developer for untreated plates. preferable. When the amount is less than 5% by mass, developability may be reduced, and the photosensitive layer may remain in non-image areas, leading to a risk of reduced visibility. If it exceeds 80% by mass, organic acids and phosphoric acid compounds tend to precipitate, which may reduce the color development of the image area.

Furthermore, it is more preferable that at least one of methanol, isopropyl alcohol, n-propyl alcohol, n-butyl alcohol, isobutyl alcohol, sec-butyl alcohol, and tert-butyl alcohol is included. Among them, methanol is more preferred.

At least one of the methanol, isopropyl alcohol, n-propyl alcohol, n-butyl alcohol, isobutyl alcohol, sec-butyl alcohol, and tert-butyl alcohol may be included, but two or more may be used in combination. The content of these is preferably 0.5 to 20% by mass, more preferably 1.5 to 15% by mass, and 3 to 10% by mass based on the developer for untreated plates. It is even more preferable. If the amount is less than 0.5% by mass, developability may be reduced, and the photosensitive layer may remain in non-image areas, resulting in reduced visibility. If it exceeds 20% by mass, organic acids and phosphoric acid compounds tend to precipitate, and there is a risk that the coloring properties of the image area may deteriorate.

In particular, it is more preferable to use the ethanol and methanol together. When using ethanol and methanol together, the content ratio of ethanol and methanol is preferably ethanol/methanol = 99/1 to 50/50, more preferably 98/2 to 70/30, and 96 More preferably, the ratio is from /4 to 85/15. If the ethanol content exceeds 99, organic acids and phosphoric acid compounds tend to precipitate, which may reduce the color development of the image area. If it is less than 50, the developability will be reduced and the photosensitive layer in the non-image area may remain, leading to a risk of reduced visibility.

The developing solution for unprocessed plates of the present invention preferably contains at least one of an organic acid and a phosphoric acid compound. Two or more of these may be used in combination.
Preferably, the organic acid includes at least one of formic acid, acetic acid, citric acid, lactic acid, malic acid, phthalic acid, benzoic acid, succinic acid, tartaric acid, oxalic acid, propionic acid, and maleic acid. Among them, citric acid and malic acid are more preferred. Two or more of these may be used in combination.

The content of the organic acid is preferably 1 to 20% by mass, more preferably 3 to 15% by mass, and preferably 5 to 10% by mass, based on the developer for untreated plates. More preferred. If the amount is less than 1% by mass, the coloring properties of the image area may deteriorate. If it exceeds 20% by mass, organic acid crystals tend to precipitate on the plate, resulting in increased stickiness and poor cleaning performance.

Examples of the phosphoric acid compounds include phosphoric acid, phosphonic acid, phosphinic acid, phytic acid, orthophosphoric acid, pyrophosphoric acid, polyphosphoric acid (triphosphoric acid, tetraphosphoric acid, etc.), metaphosphoric acid, ultraphosphoric acid, etc. Phosphoric acid and phytic acid are more preferred. Two or more of these may be used in combination.

The content of the phosphoric acid compound is preferably 1 to 20% by mass, more preferably 3 to 15% by mass, and 5 to 10% by mass based on the developer for untreated plates. It is even more preferable. If the amount is less than 1% by mass, the coloring properties of the image area may deteriorate. If it exceeds 20% by mass, crystals of the phosphoric acid compound tend to precipitate on the plate, resulting in increased stickiness, poor cleaning properties, and poor developability.

When the organic acid and the phosphoric acid compound are used together, the total content of the organic acid and the phosphoric acid compound should be 1 to 20% by mass with respect to the developer for untreated plates. The content is preferably 3 to 15% by mass, more preferably 5 to 10% by mass.

It is preferable that the developer for unprocessed plates of the present invention further contains glycol ether. Glycol ethers include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monoisopropyl ether, ethylene glycol tertiary butyl ether, ethylene glycol monobutyl ether, ethylene glycol monoisobutyl ether, and ethylene glycol monohexyl ether. , ethylene glycol mono-2-ethylhexyl ether, 3-methoxy-3-methyl-1-butanol, ethylene glycol monoallyl ether, ethylene glycol monophenyl ether, ethylene glycol monobenzyl ether, propylene glycol monomethyl ether, propylene glycol monopropyl ether, Propylene glycol monobutyl ether, propylene glycol monophenyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monoisopropyl ether, diethylene glycol monobutyl ether, diethylene glycol monohexyl ether, diethylene glycol monophenyl ether, diethylene glycol monobenzyl ether, dipropylene glycol monomethyl ether, Dipropylene glycol monopropyl ether, dipropylene glycol monobutyl ether, dipropylene glycol monoisobutyl ether, propylene glycol monomethyl ether propionate, triethylene glycol monomethyl ether, triethylene glycol monobutyl ether, tripropylene glycol monomethyl ether, tripropylene glycol mono Examples include butyl ether, polyethylene glycol monomethyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, dipropylene glycol dimethyl ether, triethylene glycol dimethyl ether, diethylene glycol monobutyl ether acetate, etc. Among them, diethylene glycol More preferred are monobutyl ether, 3-methoxy-3-methyl-1-butanol, propylene glycol monobutyl ether, diethylene glycol monobutyl ether, and diethylene glycol monobutyl ether acetate, particularly diethylene glycol monobutyl ether acetate, and 3-methoxy-3-methyl-1-butanol. is even more preferable. Two or more of these may be used in combination.

The content of the glycol ether is preferably 5 to 60% by mass, more preferably 10 to 40% by mass, and preferably 20 to 30% by mass, based on the developer for untreated plates. More preferred. When the amount is less than 5% by mass, developability may be reduced, and the photosensitive layer may remain in non-image areas, leading to a risk of reduced visibility. If it exceeds 60% by mass, organic acids and phosphoric acid compounds tend to precipitate, which may reduce the color development of the image area.

It is preferable that the developer for an untreated plate of the present invention contains water. The water is not particularly limited, and tap water, well water, distilled water, ion exchange water, pure water, etc. can be used. Among these, it is more preferable to use distilled water, ion-exchanged water, and pure water.

The water content is the remainder of each component described above, and is preferably 0 to 94% by mass, more preferably 30 to 80% by mass, and 50% by mass, based on the developer for untreated plates. More preferably, it is 70% by mass. If it is less than 10% by mass, organic acids and phosphoric acid compounds tend to precipitate, which may reduce the color development of the image area. If it exceeds 94% by mass, developability may be reduced, resulting in the photosensitive layer remaining in non-image areas, which may reduce visibility.

The developer for unprocessed plates of the present invention may contain a nonionic surfactant as another component. Examples of nonionic surfactants include polyoxyethylene alkyl ethers, polyoxyethylene alkylphenyl ethers, polyoxyethylene fatty acid esters, polyoxypropylene alkyl ethers, polyoxypropylene alkylphenyl ethers, and polyoxypropylene. In addition to fatty acid esters, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, glycerin fatty acid esters, etc., alkyl etherification of polyoxyethylene and polyoxypropylene copolymers, alkylphenyl etherification, fatty acid esterification, sorbitan Examples include active agents that have been converted into fatty acid esters. Among these, polyoxyethylene polyoxypropylene alkyl ether, polyoxyethylene alkyl ethers, polyoxyethylene alkylphenyl ethers, and dialkyl sulfosuccinates are particularly preferred, and polyoxyethylene polyoxypropylene alkyl ether is more preferred. Two or more of these may be used in combination.

The method for producing a developed unprocessed plate of the present invention includes the steps of preparing an unprocessed plate before development having an image area and a non-image area, and adding a layer to the surface of the unprocessed plate before development. It is preferable to include the steps of bringing a developer into contact with the surface of the untreated plate, and developing the image area on the surface of the untreated plate.
Untreated plates are developed using on-press development, which removes the non-image areas of the printing plate by attaching the exposed printing plate to the plate cylinder of the printing press and supplying dampening water and printing ink while rotating the plate cylinder. This is a printing plate designed so that the development process is completed during the normal printing process using a method called .
However, as mentioned above, waste paper and waste paper must be disposed of, and dampening water is also supplied at the same time, so paper with low strength (especially newsprint, uncoated paper, lightly coated paper, etc.) ), the adhesiveness of the printing ink transferred from the plate to the blanket may cause the paper to wrap around the blanket and cause the paper to break. In addition, the development process can be completed manually, and the printing plate thus produced can be loaded into a printing press and printed.

The step of preparing an unprocessed plate before development having an image area and a non-image area may be any process as long as it is a process of preparing a printing plate before development on which a photosensitive layer is formed, which is a commonly performed plate-making process. .

The step of bringing the developer for the unprocessed plate into contact with the surface of the unprocessed plate before development prepared in the preparation step may be any method as long as the developer for the unprocessed plate comes into contact with the photosensitive layer. Commonly used methods include coating with a roller, coating with a rag or sponge, coating with a squeegee or scraper, etc. Among these, it is used to continuously and smoothly develop the image area on the surface of the untreated plate in the next step. Application with a sponge is preferred because it can be easily applied. When applying with a sponge, it is preferable to take a sufficient amount of the unprocessed plate developer, spread it over the photosensitive layer, and apply this evenly over the entire plate surface.

In the step of developing the image area on the surface of the untreated plate, for example, development can be achieved by uniformly applying a developer for the untreated plate over the entire plate surface as described above, and then adding water as needed. In some cases, this includes a step of wiping off excess developer and excess photoresist film in non-image areas with a clean sponge or the like.

By doing this, the development process is completed without removing the non-image areas of the printing plate by on-press development process, which is installed on the printing press and supplies dampening water and printing ink while rotating the plate cylinder. There is no need to waste paper or waste paper during on-press development processing, and there is no fear of running out of paper. Furthermore, according to the method for producing a non-processing plate using the developer for non-processing plates of the present invention, since the developability and coloring property are excellent, the development state of the printing plate (the state of the image area) can be visually checked, and the printing It becomes easier to manage and check versions.

Below, examples of reference forms will be added.
(1) A developer for an untreated plate for developing an untreated plate,
A developing solution for unprocessed plates, comprising ethanol and at least one of an organic acid and a phosphoric acid compound.
(2) The untreated product according to (1), further containing at least one of methanol, isopropyl alcohol, n-propyl alcohol, n-butyl alcohol, isobutyl alcohol, sec-butyl alcohol, and tert-butyl alcohol. Plate developer.
(3) The developing solution for unprocessed plates according to (2), wherein the content ratio of the ethanol and methanol is ethanol/methanol=99/1 to 50/50.
(4) The organic acid includes at least one of formic acid, acetic acid, citric acid, lactic acid, malic acid, phthalic acid, benzoic acid, succinic acid, tartaric acid, oxalic acid, propionic acid, and maleic acid. The developer for untreated plates according to any one of (1) to (3).
(5) Any of (1) to (3), wherein at least one of the organic acid and phosphoric acid compound is at least one selected from citric acid, malic acid, and phosphoric acid. A developing solution for unprocessed plates described in Kani.
(6) The developer for unprocessed plates according to any one of (1) to (5), further comprising glycol ether.
(7) preparing an unprocessed plate before development having an image area and a non-image area;
A step of contacting the surface of the untreated plate before development with the developer for the untreated plate according to any one of (1) to (6);
A method for producing a developed untreated plate, comprising the step of developing an image area on the surface of the untreated plate.

EXAMPLES Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples. In addition, in the examples, "part" indicates "part by mass", and "%" indicates "% by mass".

[Preparation of developer for untreated plate]
<Example 1>
39 g of Neocol C (manufactured by Nippon Alcohol Sales Co., Ltd.), 10 g of citric acid, and 61 g of ion exchange water were added and stirred to prepare developer solution 1. Similarly, developers 2 to 23 were prepared according to the formulations in Tables 1 to 3.

The materials used are as follows.
Neocol C: Mixed alcohol containing 83.5% ethanol, 3.5% methanol, 6.5% normal propyl alcohol, and 6.5% water, manufactured by Nippon Alcohol Sales Co., Ltd. Neocol R7: 86.2% ethanol, methanol Mixed alcohol containing 2.6%, isopropyl alcohol 1.5%, normal propyl alcohol 9.5%, and water 0.2%, manufactured by Nippon Alcohol Sales Co., Ltd. Neocol ME: ethanol 80.4%, methanol 11.8% %, mixed alcohol containing 7.8% water, manufactured by Nippon Alcohol Sales Co., Ltd. Neocol CP: mixed alcohol containing 82.5% ethanol, 13.6% isopropyl alcohol, and 3.9% water, manufactured by Nippon Alcohol Sales Co., Ltd. ) manufactured by Solmix AP7: mixed alcohol containing 85.597% ethanol, 4.9% isopropyl alcohol, 9.5% normal propyl alcohol, and 0.03% water, manufactured by Nippon Alcohol Sales Co., Ltd. Citric acid: citric acid fuso (anhydrous), manufactured by Fuso Chemical Industries, Ltd. Malic acid: fuso malic acid, manufactured by Fuso Chemical Industries, Ltd. Phosphoric acid: 85% phosphoric acid, manufactured by Katakura Co-op Agri, Ltd. Solfit: 3-methoxy-3-methyl -1-Butanol, manufactured by Kuraray Co., Ltd.

The storage stability, developability, and color development of the developer were evaluated and shown in Table 4.

[Storage stability]
The prepared developer solution was placed in a 200 ml glass bottle and allowed to stand in a refrigerator for one week, and the condition of each developer solution was visually observed and evaluated. Regarding the state of the developer, it was judged that the developer had good storage stability if no separation or precipitation was observed. Separation and precipitation were evaluated in three stages: ○: No change from immediately after preparation, △: Slight separation or precipitation (no practical problem), ×: Complete separation or a large amount of precipitation. . Those whose storage stability was evaluated as "x" were shaken well to obtain a uniformly mixed state, and the following evaluations were performed.

[Developability]
A sponge was soaked with 50 ml of the prepared developer, and the 0 to 100% halftone density gradation area of the photosensitive layer prepared on the untreated plate was wiped, this was repeated several times, and finally the developer and water were wiped off.
The number of times the plate was wiped until the last wipe was recorded, and the state of the non-image area on the plate was observed using a confocal microscope (manufactured by Lasertec Co., Ltd.) to evaluate developability. It was judged that the developability was good when the number of times of wiping was small and the remaining amount of the photosensitive layer in the non-image area was small.
Regarding developability, ◎: Wiped off less than 5 times and no photosensitive layer in the non-image area remains, ○: Wiped off less than 5 times and almost no photosensitive layer remains on the non-image area, △: Wiped off Evaluation was made on a four-point scale: 5 or more times but less than 10 times, the photosensitive layer in the non-image area remains slightly (practical level), ×: wiping is performed 10 times or more, the photosensitive layer in the non-image area remains. .

[Color development]
A sponge was soaked with 50 ml of the prepared developer, and the 0 to 100% halftone density gradation area of the photosensitive layer prepared on the untreated plate was wiped, this was repeated several times, and finally the developer and water were wiped off.
The state of the image area on the printing plate was visually observed and the color development was evaluated. It was judged that the coloring property was good if the photosensitive layer in the image area could be visually confirmed. 3 items have good coloring and the image area can be clearly seen; 2 items have slightly weak coloring but the image area can be clearly seen; 1 item has weak coloring but the image area can be clearly seen. If the image area was difficult to visually confirm, a score of 0 was given, and the number of observers was 5, and the average was taken (rounded to the second decimal place).
Regarding color development, ◎: Average score of 5 observers is 3.0 to 2.6, ○: Average score of 5 observers is 2.4 to 2.0, △: Average score of 5 observers is 3.0 to 2.6. 1.8 to 1.4 (practical level), ×: average score of 5 observers is 1.2 to 0.8, XX: average score of 5 observers is 0.6 to 0. It was evaluated by

Using the developing solutions shown in Tables 1 and 2, hand development was performed according to the following procedure, and a printing test was also conducted to produce printed matter. Incidentally, those with the developability evaluation of "x" were not subjected to manual development.
<Hand development>
Untreated version: SONORA CX2 manufactured by Kodak LLC, thickness 0.3mm

Place the exposed untreated plate on a clean and flat desk, take a sufficient amount of the developer for the untreated plate with a clean sponge, and apply it to the surface of the untreated plate. When the developer is running low, The film was taken up again with a sponge, and this process was repeated for development. Once it was spread evenly, I took an appropriate amount of water on a clean sponge, rubbed the surface of the untreated plate lightly, and wiped off the photoresist film and excess developer in the non-image areas to clean the surface of the untreated plate.
<Printing test>
Printing machine: Komori Corporation System 35S 4-color offset rotary press Printing speed: 600 rpm
Printing ink: Gaia ink, indigo, red, yellow, manufactured by Tokyo Ink Co., Ltd. Paper: Aurora S, manufactured by Nippon Paper Industries, Ltd. Paper thickness: 44 μm, basis weight: 48 g/m ²

The hand-developed untreated plate was mounted on a printing machine, and printing was started. As a reference example, a printing test was also conducted using an untreated plate that had been subjected to on-press development.
In the printing test, suitability for printing at the start of printing, scumming resistance during continuous printing, and printing durability were evaluated, and the results are shown in Table 5.

[Suitability for printing]
During the above printing test, the number of sheets printed from the start of printing until reaching the main paper (printed matter that can be evaluated as OK) was evaluated. It was judged that the printability was good when the number of printed sheets was small. The printing performance was evaluated in four stages: ◎: less than 500 sheets, ○: 500 sheets or more and less than 1000 sheets, Δ: 1000 sheets or more and less than 3000 sheets, ×: 3000 sheets or more.

[Screen resistance]
During the above printing test, the state of the printed matter was visually observed after 80,000 copies were continuously printed after printing was started, and the degree of staining in the non-image area was evaluated. Prints with less staining in non-image areas were judged to have good scumming resistance. Regarding background smudge resistance, there are three levels: ○: No stains in non-image areas, △: Slight stains in non-image areas (practical level), ×: Stains in non-image areas are clearly visible. evaluated.

[Printing durability]
During the above printing test, after the start of printing, the condition of the printed matter was visually observed after 80,000 copies were continuously printed, and the degree of fading (defects) in the image area was evaluated. It was judged that printed matter with less blurring (defects) in the image area had less influence on the image development area of the untreated plate and had good printing durability. Regarding printing durability, ○: No effect on the image development area at all, △: Effect on the image development area is partially seen (practical level), ×: Fading is observed throughout the image development area. Evaluated in stages.

From Table 4, it is clear that the unprocessed plate developers of Examples 1 to 18 have good storage stability, developability, and color development. It is clear that the ethanol-free developers of Comparative Examples 1 to 3 have poor developability and color development, the photosensitive layer in the non-image area tends to remain, and the photosensitive layer in the image area cannot be confirmed. It is clear that the developing solution containing neither the organic acid nor the phosphoric acid compound of Comparative Example 4 also has poor developability and color development. It is clear that in Comparative Example 5, which uses another alcohol and does not contain either an organic acid or a phosphoric acid compound, not only the developability and coloring property are poor, but also the storage stability is poor.
From Table 5, which is the result of the actual printing test, the untreated plates developed by hand using the developing solutions for untreated plates of Examples 1 to 18 are different from the untreated plates (reference example) that were subjected to conventional on-press development processing. It is clear that the printability is equivalent or better.

Claims (5)

A developer for a non-processed plate for developing a non-processed plate,
Contains ethanol, methanol, and at least one of an organic acid and a phosphoric acid compound ,
A developing solution for an unprocessed plate, characterized in that the content ratio of the ethanol and the methanol is ethanol/methanol=99/1 to 50/50 . The development for an untreated plate according to claim 1 , further comprising at least one of isopropyl alcohol, normal propyl alcohol, normal butyl alcohol, isobutyl alcohol, sec-butyl alcohol, and tert-butyl alcohol. liquid. The organic acids and phosphoric acid compounds include formic acid, acetic acid, citric acid, lactic acid, malic acid, phthalic acid, benzoic acid, succinic acid, tartaric acid, oxalic acid, propionic acid, maleic acid , phosphoric acid, phosphonic acid, and phosphine. The developing solution for unprocessed plates according to claim 1 or 2, characterized in that it contains at least one of acid, phytic acid, orthophosphoric acid, pyrophosphoric acid, tripolyphosphoric acid, tetrapolyphosphoric acid, metaphosphoric acid, and ultraphosphoric acid. . preparing an unprocessed plate prior to development having an image area and a non-image area;
A step of bringing the developer for an untreated plate according to claim 1 or 2 into contact with the surface of the untreated plate before development;
A method for producing a developed untreated plate, comprising the step of developing an image area on the surface of the untreated plate. preparing an unprocessed plate prior to development having an image area and a non-image area;
A step of contacting the surface of the untreated plate before development with the developer for the untreated plate according to claim 3;
A method for producing a developed untreated plate, comprising the step of developing an image area on the surface of the untreated plate.