JPH04158368A - Processing solution for water-less planography - Google Patents

Abstract

PURPOSE:To improve the processing effect such as the solvent resistance and developing property and extend the life of a processing solution by containing 1,3-dialkyl-2-imidazolidone in the processing solution. CONSTITUTION:A processing solution for water-less planography coated with a photosensitive layer made of a material containing a quinonediazido structure and a silicone rubber in this order on a carrier is mainly made of a solvent and 1,3-dialkyl-2-imidazolidone expressed by the formula I, where R1, R2 are alkyl groups with the carbon number 1-10, they may be the same or different, R3, R4 are the hydrogen atom or alkyl groups with the carbon number 1-10, and they may be the same or different.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a processing liquid for waterless lithography,
More specifically, the present invention relates to a processing liquid for waterless lithography that has excellent processing effects and a long service life.

[Prior Art] Various types of waterless lithographic printing plates comprising a photosensitive layer and a silicone rubber layer are known. In particular, negative and positive amphoteric waterless lithographic plates can be produced by amine-treating an image-forming laminate comprising a support, in which a photosensitive layer containing a substance containing a quinone diazide structure and a silicone rubber layer are provided in this order. As disclosed in JP-A No. 59-17552, a method for obtaining a printing plate widens the development latitude of a waterless lithographic printing plate, including image reproducibility, solvent resistance, developability, etc. It has excellent features such as the fact that positive plates can be made from the same plate material. The base treatment methods described in these patents use amines alone or in a mixture in gas phase or liquid form, and in the case of liquid form, water or a known organic solvent is used as the solvent.

As described above, in waterless lithography processing solutions according to the prior art, amines have been used in particular, and amines have been used to reduce the amine concentration or process the amines, which is thought to be due to their volatility and the formation of carbonates with carbon dioxide in the air. There is a problem of decreased effectiveness, and it has been desired to develop other processing liquids that do not have these drawbacks and have excellent processing effects.

[Problems to be Solved by the Invention] As a result of intensive studies to improve the problems of the prior art, the present inventors found that when using a treatment liquid containing 1,3-dialkyl-2-imidazolidone, The present invention was achieved based on the discovery that the above-mentioned problems and points can be satisfactorily solved while having a treatment effect equivalent to or higher than that obtained when using the above-mentioned amine.

Therefore, an object of the present invention is to provide a waterless lithographic processing solution that has excellent processing effects such as image reproducibility, solvent resistance, and developability, and has a long lifespan without deterioration of processing effects. .

[Means for Solving the Problems] That is, the present invention provides a processing solution for waterless lithographic plate making, which is formed by coating a photosensitive layer containing a substance containing a quinonediazide structure as a constituent component and a silicone rubber layer on a support in this order. A waterless lithographic processing liquid is characterized in that the processing liquid mainly consists of a solvent and a 1,3-dialkyl-2-imidazolidone represented by the following general formula [I].

ζ (Here, R1 and R2 are alkyl groups having 1 to 10 carbon atoms and may be the same or different. R3 and R4 are hydrogen atoms or alkyl groups having 1 to 10 carbon atoms, and may be the same or different. ) The solvents used in the treatment solution of the present invention include water, alcohols (methanol, ethanol, 1-propanol, 2-propanol, 3-methoxybutyl alcohol, 2-methylpene, etc.). Tanol-1, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol,
propylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol), esters (ethyl acetate, ethyl cellosolve acetate, methyl cellosolve acetate, carpitol acetate, etc.), ethers (ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, diethylene glycol) Monoethyl ether, diethylene glycol monobutyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monobutyl ether, polyethylene glycol monomethyl ether,
Propylene glycol monomethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, dipropylene glycol monomethyl ether, tripropylene glycol monomethyl ether, polypropylene glycol monomethyl ether, etc.), ketones (cyclohexanone, acetonyl acetone, diacetone alcohol, etc.) ), and these may be used alone or in combination. Furthermore, an emulsion made with a suitable emulsifier or surfactant can also be used.

The 1,3-dialkyl-2-imidazolidone used in the present invention is represented by general formula (I).

(Here, RI and R2 are alkyl groups having 1 to 10 carbon atoms and may be the same or different. R3 and R4 are hydrogen atoms or alkyl groups having 1 to 10 carbon atoms, and may be the same. C may also be different.) Above-1 general formula (I)
The 1,3-dialkyl-2-imidazolidone represented by the formula has good compatibility with the processing solvent, excellent stability, and low toxicity.

Specific examples of 1,3-dialkyl-2-imidazolidones that can be used in the present invention include, but are not limited to, the following.

1,3-dimethyl-2-imidazolidone, 1゜3-diethyl-2-imidazolidone, 1,3-dipropyl-2-
imidazolidone, 1,3-dibutyl-2-imidazolidone, 1,3-dioctyl-2-imidazolidone, 1,3
．． 4-1-limethyl-2-imidazolidone, 1,3-dimethyl-4-ethyl-2-imidazolidone, 1.3.4.
5-tetramethyl-2-imidazolidone, 1.3.4°5-tetraethyl-2-imidazolidone.

The treatment liquid of the present invention can be prepared by adding at least one type of 1,3-dialkyl-2-imidazolidone to the above-described treatment liquid solvent or a mixed solvent thereof.

The amount of 1,3-dialkyl-2-imidazolidone to be blended into the treatment liquid is not particularly limited, but from the viewpoint of treatment effect and economical efficiency, it is 0.000% based on the total amount of the treatment liquid. It is preferably added in an amount of 1 to 70% by weight, more preferably 0.
．． It is 3 to 45% by weight.

When used as a treatment liquid, a surfactant may be added to the treatment liquid to improve wettability.

In addition, when developing as is with a processing solution, dyes such as Neptune Blue Base 627 (manufactured by BASF), Eisen Victoria Blue BH1 Eisen Marine RNX (manufactured by Hodogaya Chemical Co., Ltd.) are used to improve plate inspection. can also be added to the processing solution.

Furthermore, aliphatic hydrocarbons (hexane, heptane, gasoline, kerosene, "Isopar" (manufactured by Exxon Chemical), etc.) may be added to the treatment liquid.

The supports used in the present invention are those used in ordinary waterless lithographic printing plates, or those that have been proposed.
For example, metal plates such as aluminum, iron, and zinc; transparent or opaque plastic films such as polyester, polyolefin, and polystyrene;
Alternatively, a complex of both may be mentioned. It is also possible to further coat these sheets with a resin layer or the like for antihalation purposes or other purposes to form a support.

The photosensitive layer referred to in the present invention is composed of a substance containing a known quinonediazide structure, and the substance containing a quinonediazide structure is one that is normally used in positive-working PS plates, Wibon plates, photoresists, etc. They are quinonediazides.

Examples of such quinonediazides include esters of benzoquinone-1,2-diazide-4- or -5-sulfonic acid and polyhydroxyphenyl, naphthoquinone-1
, ester of 2-diazide-4- or -5-sulfonic acid and pyrogallolacetone resin, naphthoquinone-1,
Esters of 2-diazide-4- or -5-sulfonic acid and phenol formaldehyde novolac resins or cashew-modified novolak resins may be mentioned. Also, low amounts of quinonediazide compounds (e.g. naphthoquinone-1,2
esters of -diazide-5-sulfonic acid with phenol, cresol, xylenol, catechol, pyrogallol, bisphenol A, etc.) or novolak resins that do not contain photosensitive groups in the resins containing the quinonediazide group (e.g., phenol, A soluble resin obtained by condensing phenols such as cresol, xylenol, catechol, and pyrogallol with formaldehyde in the presence of an acidic catalyst may be simply mixed. Furthermore, there may be mentioned a photoreleasable photosensitive layer in which quinone diazides are crosslinked with a polyfunctional compound as proposed in JP-A-56-80046.

As a crosslinking agent, polyfunctional isocyanates such as
paraphenylene diisocyanate, 2°4- or 2.
6-) lylene diisocyanate, 4,4'-diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate or adducts thereof, or polyfunctional epoxy compounds such as polyethylene glycol diglycidyl ethers,
Examples include polypropylene glycol diglycidyl ethers, bisphenol A diglycidyl ether, and trimethylolpropane tricidyl ether. These thermal curing temperatures are within a range that does not cause loss of photosensitivity of the photosensitive material, usually 1
It is preferable to carry out the reaction at a temperature of 30° C. or lower, and therefore a catalyst or the like is usually used in combination.

In addition, methods for modifying quinonediazides by reacting them with monofunctional compounds to make them poorly soluble or insoluble in developing solutions include esterifying, amidating, or urethanizing the active groups of the quinonediazides. Can be mentioned. The compound to be reacted with the active group of the quinonediazide may be a low-molecular compound or a relatively high-molecular compound, or a monomer may be graft-polymerized to the quinonediazide.

Particularly preferable photosensitive layers for use in the present invention are:
It is obtained by crosslinking or modifying a partially esterified product of naphthoquinone-1,2-diazide-5-sulfonic acid and phenol formaldehyde novolak resin with a polyfunctional or monofunctional isocyanate.

The thickness of the photosensitive layer is approximately 0. 1-100μ, preferably about 0
．． 5 to 10μ is appropriate. If the blade is too thin, defects such as pinholes are likely to occur during coating, and if the blade is too thick, it is disadvantageous from an economic standpoint. Further, it is possible to add other components to the photosensitive layer for the purpose of improving coating film forming properties and adhesion to the support within a range that does not impair the effects of the present invention.

The silicone rubber layer used in the present invention is preferably one whose main component is a linear organic polysiloxane having the following repeating units and having a molecular weight of several thousand to several hundred thousand.

Shizu-I-8iO@□・・・・・・1111, □□, ;□;
-■ Here, n is an integer of 2 or more, and R1 and R2 have 1 to 10 carbon atoms.
is an alkyl group, alkenyl group or phenyl group, and preferably 60% or more of the sum of RI and R2 is a methyl group.

A crosslinking agent is usually added to this linear organic polysiloxane. Examples of crosslinking agents used in so-called room temperature (low temperature) curing silicone rubber include acetoxysilane,
There are ketooxime silanes, alkoxysilanes, aminosilanes, amidosilanes, etc., which are usually linear organopolysiloxanes in combination with terminal or hydroxyl groups to produce acetate-removed type, oxime-eliminated type, alcoholic type, deamined type, and deamidated type, respectively. It becomes the silicone rubber of the mold. A small amount of an organic tin compound or the like may be added as a catalyst to these silicone rubbers.

The thickness of the silicone rubber layer is about 0.5-100μ, preferably about 0.5μ. A thickness of 5 to 10 μm is appropriate; if the blade is too thin, problems may occur in terms of printing durability, and if the blade is too thick, it is not only economically disadvantageous, but also makes it difficult to remove the silicone rubber layer during development. This makes it difficult, resulting in a decrease in image reproducibility.

In the printing plate used in the present invention, a support, a photosensitive layer,
Adhesion between the photosensitive layer and the silicone rubber layer is very important for basic plate performance such as image reproducibility and printing durability. It is possible to sip with the addition of improving ingredients. In particular, it is effective to provide a known silicone primer or silane coupling agent layer between the layers, or to add a silicone primer or silane coupling agent to the silicone rubber layer or photosensitive layer, in order to increase the adhesive strength between the photosensitive layer and the silicone rubber layer. be.

A thin protective film can also be laminated on the surface of the waterless lithographic printing original plate constructed as described above.

The waterless lithographic printing original plate used in the present invention is manufactured, for example, as follows. First, the composition to constitute the primer layer is applied onto the support using a normal coater such as a reverse roll coater, an air knife coater, a Meyer bar coater, or a rotary coating device such as a wheller, and then dried and coated as necessary. It is heat cured to form a primer layer. A photosensitive layer composition for forming a photosensitive layer is applied onto the primer layer, dried, and if necessary, thermally cured to form a photosensitive layer.

After forming an adhesive layer on the photosensitive layer, an uncured silicone rubber composition is applied, and the adhesive layer is usually 50 to 130 %.
It is heat-treated at a temperature of 0.degree. C. for several minutes to fully cure and form a silicone rubber layer.

If necessary, cover the silicone rubber layer with a protective film using a laminator or the like.

When the waterless lithographic printing original plate thus obtained is subjected to image exposure using a positive film, a positive original image, or a negative film or a negative original image, and then developed, a waterless lithographic printing plate is obtained.

Examples of the plate-making method for such a waterless lithographic printing original plate include the following. For example, when used as a positive waterless lithographic printing original plate, 5 to 60 of the quinonediazide units of the substance containing the quinonediazide structure in the photosensitive layer are exposed to actinic light through a vacuum-adhered positive film or positive original.
Image exposure is given such that mol% of the solvent and 1
, 3-dialkyl-2-indasilidone, and simultaneously development, a waterless lithographic printing plate can be obtained.

On the other hand, when used as a negative waterless lithographic printing plate,
Through vacuum sealed negative film or negative original image,
After applying normal imagewise exposure to actinic light (imagewise exposure so as to photodecompose more than 60 mol% of the quinonediazide units of the substance containing the quinonediazide structure in the photosensitive layer), the solvent and 1,3-dialkyl-2 - Processing with a processing solution containing indasilidone and then developing, processing with a processing solution containing a solvent and 1,3-dialkyl-2-imidazolidone and developing at the same time, or developing and then developing with a solvent and 1,3-dialkyl-2-imidazolidone.
A waterless lithographic printing plate is obtained by treatment with a treatment solution containing dialkyl-2-imidazolidone.

The light source used in this exposure process is one that generates abundant ultraviolet light, and can be a mercury lamp, a carbon arc lamp, a xenon lamp, a metal halide lamp, a fluorescent lamp, or the like. Furthermore, in addition to ultraviolet rays, laser light and the like can also be used.

Examples of the treatment method using the treatment liquid of the present invention include the following methods.

A, negative type (1) Whole surface exposure → image exposure - treatment with a processing solution containing a solvent and 1,3-dialkyl-2-imidazolidone → development (2) image exposure → whole surface exposure → solvent and 1,3-dialkyl-2-imidazolidone - Treatment with a processing solution containing imidazolidone → Development (3) Full-surface exposure → Image exposure → At the same time as development, the solvent and 1°3
- Treatment with a processing solution containing dialkyl-2-imidazolidone (4) Image exposure → full-scale exposure → development and simultaneously with a solvent at 1°3
- Treatment with a processing solution containing dialkyl-2-imidazolidone (5) Full-surface exposure → Image exposure → Development → Processing with a processing solution containing a solvent and 1,3-dialkyl-2-imidazolidone (6) Image exposure → Full-surface exposure → Development - Processing with a processing liquid containing a solvent and 1,3-dialkyl-2-imidazolidone ■ Image exposure → Development → Full-surface exposure → Processing with a processing liquid containing a solvent and 1,3-dialkyl-2-imidazolidone (8) Image exposure - Development - solvent and 1,3-dialkyl-2
- Treatment with a processing solution containing imidazolidone (9) Image exposure → Treatment with a processing solution containing a solvent and 1,3-dialkyl-2-imidazolidone → Development (g) Image exposure → At the same time as development, a solvent and 1,3-dialkyl- Treatment B with a processing solution containing 2-imidazolidone, positive type (1) image exposure → solvent and treatment with a processing solution containing 1,3-dialkyl-2-imidazolidone → development (2) image exposure → development and simultaneously with the solvent and 1 , 3-dialkyl-2-imidazolidone can be carried out by uniformly wetting the plate surface with the processing solution of the present invention using, for example, a brush or a pad.

The treatment time is not particularly limited, and 1,3-dialkyl-2-
The imidazolidone compound can be appropriately selected depending on the strength and concentration of the imidazolidone compound and the temperature of the processing solution, but usually the effect appears immediately upon contact with the processing solution, and there is no change in the effect even if the imidazolidone compound is in contact for a long time. Usually it takes about 10 seconds to 15 minutes.

As the developer used in the present invention, those commonly proposed for waterless lithographic printing plates can be used.

For example, water and water with the following polar solvent added are suitable.

Alcohols (methanol, ethanol, etc.) Ethers (dioxane, ethyl cellosolve, methyl cellosolve,
(butyl cellosolve, methyl calpitol, ethyl calpitol, butyl calpitol, etc.) Esters (ethyl acetate, ethyl cellosolve acetate, methyl cellosolve acetate, carpitol acetate, etc.) It is also possible to directly develop with the processing solution of the present invention.

[Examples] The present invention will be explained in more detail by Examples below, but the present invention is not limited thereto.

Example 1.2, Comparative Example 1 The following primer composition was applied to a 0.3 mm thick aluminum plate (manufactured by Sumitomo Light Metal Co., Ltd.), and heat treated at 200°C for 2 minutes to form a 5μ thick primer layer. .

■Polyurethane resin (“Sunbren” LQ-71331
, manufactured by Sanyo Chemical Industries, Ltd.) 100 parts by weight ■Blocked isocyanate (“Takenate” B2S3
, manufactured by Shikinichi Yakuhin Co., Ltd.) 20 parts by weight ■Epoxy/phenol/urea resin (SJ9372, manufactured by Kansai Paint Co., Ltd.) 8 parts by weight ■Dimethylformamide
Subsequently, 725 parts by weight of the photosensitive layer composition shown below was coated thereon using a bar coater and dried for 1 minute in hot air at 110° C. to form a photosensitive layer having a thickness of 2 μm.

■Partial ester of naphthoquinone-1,2-diazide-5-sulfonic acid and phenol formaldehyde novolac resin (Sumitomo Durez: “Sumilight Resin” PH10622) (degree of esterification 25% by elemental analysis)
100 parts by weight■4,4'-diphenylmethane diisocyanate 40 parts by weight■Dibutyl pan diacetate 0.2 parts by weight■4,4'
- Diethylaminobenzophenone 5 parts by weight ■ P-toluenesulfonic acid 0.8 parts by weight ■ Tetrahydrofuran 800 parts by weight Next, a silicone rubber composition having the following composition was spin-coated on the photosensitive layer, and the temperature was 115°C, dew point 30°C, A 2.3 micron silicone rubber layer was provided by moist heat curing for 3.5 minutes.

■Polydimethylsiloxane (number average molecular weight 2, o, o
oo, terminal OH group) 100 parts ■ Vinyl tris (methyl ethyl ketoxime) silane
8 parts by weight ■ Dibutyltin diacetate 0.1 part by weight ■ γ-aminopropyltrimethoxysilane 0.5 parts by weight ■ "Isopar" E (manufactured by Exxon Chemical Co., Ltd.) 1400
Part by weight: Add a polypropylene film “Torefane” (manufactured by Toshiku Co., Ltd.) with a thickness of 1゜μ to the laminate obtained as above.
were laminated using a calendar roller to obtain a waterless lithographic printing original plate.

A metal halide lamp ("Idolfin" 2000, manufactured by Iwasaki Electric Co., Ltd.) was used for the original printing plate, and a U meter (manufactured by Oak Manufacturing Co., Ltd., light measure type UV402) was used.
In A), the entire surface was exposed for 6 seconds at an illuminance of 11 mw/car.

A negative film having a halftone image of 150 lines/inch was vacuum-adhered to the printing original plate obtained as described above, and imagewise exposed for 60 seconds from a distance of 1 m using the metal halide lamp described above.

Next, the "Trephan" of the above-mentioned exposure suit was peeled off and placed in a flat vat filled with processing solutions of various compositions listed in Table 1.
Immerse for 1 minute at a liquid temperature of 25°C. After dipping, use a rubber squeegee to remove the processing liquid adhering to the plate surface and back surface, and then apply developer solution (water/butyl calpitol/2-ethylbutyric acid/crystal violet = 70/
30/210.2 (weight ratio) was poured and the printing plate was lightly rubbed with a developing pad to remove the image-exposed silicone rubber layer and expose the surface of the photosensitive layer. On the other hand, the silicone rubber layer remained firmly in the area where only the entire surface was exposed, and an image faithfully reproducing the negative film was obtained. This printing plate was attached to an offset printing machine, and printing was performed using "Toyo King Ultra TKU Aquares G Eye PL" manufactured by Toyo Ink Co., Ltd., and halftone dot reproducibility was evaluated. Table 1 shows the halftone reproducibility.

As is clear from Table 1, Examples 1 and 2 based on the present invention exhibit good halftone dot reproducibility.

On the other hand, with the processing liquid used in Comparative Example 1, the halftone reproducibility was extremely poor, and due to insufficient processing, dot-like and scratch-like defects occurred in the non-image areas (solid white areas) of the printed matter.

Example 3, Comparative Example 2 The processing solutions listed in Table 2 were processed using a waterless lithographic automatic processor (TWL-
18 liters of water was put into a pre-treatment tank (manufactured by 1160 Toshi ■), and 40 liters of water was put into a developing tank. Pretreatment liquid temperature 45
℃, development water temperature of 25℃, and conveyance speed of 40 cm/min, the waterless lithographic printing original plate obtained in Example 1 was subjected to full-surface exposure and image exposure in the same manner as in Example 1. I peeled off the "Fan" and sent it to an automatic developing machine to develop it. Kikuzen version mail order sampled the processing solution at the 250th, 500th, and 1000th sheet, measured the concentration of amine and 1,3-dialkyl-2-imidazolidone, and evaluated halftone reproducibility. This was also carried out in the same manner as in Example 1.

Table 2 shows the results.

As is clear from Table 2, based on the present invention, in the case of Example 3, the halftone reproducibility did not deteriorate even after printing 1000 Kikuzen plates, and moreover, It can be seen that there is little change in concentration and that the treatment liquid can be used for a long period of time.

On the other hand, in the case of Comparative Example 2, good halftone dot reproducibility is shown when 250 sheets of the Kikuzen plate are passed, but the halftone dot reproducibility decreases when 500 sheets are passed. In addition, it is thought that the concentration of monoethanolamine, which is a base component, sharply decreases, resulting in a significant decrease in the base treatment effect, and it can be used only about 1/3 compared to when using the treatment liquid of the present invention. The life of the treatment liquid was extremely short.

Example 4 Phenol formaldehyde novolac resin (Sumitomo Durez Co., Ltd.: “Sumilight Resin” PR5) with a degree of esterification of 44% was applied to a chemically treated aluminum plate (manufactured by Sumitomo Light Metal Co., Ltd.)
0235) naphthoquinone-1,2-diazide-5-sulfonic acid ester (ethanol soluble component 9.7% by weight)
, the degree of esterification is 3% by weight (quantified from IR spectrum)
After applying the dioxane solution, it was dried at 60° C. for 3 minutes to obtain a photosensitive layer with a thickness of 1.2 μm. On top of this photosensitive layer is a 7% "Isopar" E silicone rubber composition having the following composition:
γ-Aminopropyltriethoxysilane (manufactured by UCC ■: AO800) was added to the solution in an amount of 4% by weight based on the silicone composition.
) was added and uniformly coated after stirring. 120°C after drying
A silicone rubber layer having a thickness of 2.2 μm was obtained by heating and curing at a dew point of 25° C. for 4 minutes.

■100 parts by weight of polydimethylsiloxane (approx. intermolecular so, ooo, OH groups at both ends) ■5 parts by weight of ethyltriacetoxysilane ■0.2 parts by weight of dibutyltin diacetate Waterless lithographic printing obtained as above A grandeur John negative film having halftone dots of 2% to 98% at 150 lines/inch was vacuum-adhered to the original plate according to a conventional method, and the film was vacuum-adhered to the original plate using the same metallization lamp used in Example 1 at a distance of 1 m. U used in
Image exposure was performed for 60 seconds at an illuminance of 11 mw/cnf using a V meter. Furthermore, the grandeur negative film was removed and the entire surface was exposed for 10 seconds (a light intensity at which 25 mol % of the quinone diazide in the photosensitive layer was photodecomposed to produce a carboxylic acid component).

Next, it is immersed in the treatment liquid of Example 1 at a liquid temperature of 25° C. for 1 minute. After dipping, use a rubber squeegee to remove the processing liquid adhering to the plate surface and back surface, and add ethanol/"Isopar" E.
= 80/20 (weight ratio) When rubbed with a developing pad impregnated with a developer, 5% to 95% halftone dots are reproduced, the silicone rubber layer in the non-image area is not damaged at all, and 1 ,3
The fixing effect of the -dialkyl-2-imidazolidone treatment was sufficient.

[Effects of the Invention] The waterless lithographic processing liquid of the present invention has the following properties as described above.
Because it contains 3-dialkyl-2-imidazolidone, it has extremely excellent processing effects such as image reproducibility, solvent resistance, and developability (A, and it also reduces the amount of active ingredients in the processing solution like amines). As a result, the life of the processing liquid is significantly extended, and significant practical effects such as a reduction in the number of replacements of the processing liquid and a reduction in the amount used can be achieved.

Patent applicant: Toshi Co., Ltd.

Claims (1)

[Scope of Claims] 1. A processing solution for waterless lithographic plate making, in which a photosensitive layer containing a substance containing a quinonediazide structure and a silicone rubber layer are coated on a support in this order, wherein the processing solution is a solvent and a silicone rubber layer. A processing liquid for waterless lithographic plate making, characterized in that it mainly consists of 1,3-dialkyl-2-imidazolidone represented by the following general formula [I]. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (I) (Here, R_1 and R_2 are alkyl groups having 1 to 10 carbon atoms and may be the same or different. R_3, R_4
is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms,
They may be the same or different. )