JPH0269756A - Method for plate-making waterless planographic printing plate - Google Patents

Abstract

PURPOSE:To improve developability and to widen development latitude by exposing a waterless planographic printing plate to image exposing then to a base treatment and full-surface exposing followed by a development processing. CONSTITUTION:The waterless planographic printing plate constituted by providing a photosensitive layer consisting of a material contg. a quinonediazide structure as its constituting component and a silicone rubber layer in this order on a base is subjected to the image exposing then to the base treatment and the full-surface exposing followed by the development processing. Namely, if the part subjected to the image exposing in such a manner that the material contg. the quinonediazide structure is photodecomposed is subjected to the base treatment, the adhesive strength to the silicone rubber layer existing thereon is improved and the solvent resistance thereof is greatly improved. Both the photosensitive layer and the silicone rubber layer, therefore, remain on the base to form a non-image part without allowing the silicone rubber layer existing on the silicone rubber layer to remain even if the printing plate is subjected to the development processing after the full-surface exposing in the post stage. The developability is greatly improved in this way and the development latitude is widened.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for making a waterless lithographic printing plate, and particularly to waterless lithographic printing for positive working using a photosensitive material containing a quinonediazide compound as a photosensitive component. It concerns the method of plate making.

[Prior Art] Various types of waterless lithographic printing plates comprising a photosensitive layer and a silicone rubber layer are known. Among these, negative and positive amphoteric type waterless lithographic printing can be achieved by base-treating an image forming laminate comprising a support, in which a photosensitive layer containing a substance containing a quinonediazide structure and a silicone rubber layer are provided in this order. The method to obtain the plate is published in Japanese Patent Application Laid-open No. 1983.
- As disclosed in No. 17552, the development latitude of waterless lithographic printing plates including image reproducibility, solvent resistance, developability, etc. can be expanded, and negative and positive plates can be made from the same plate material. It has excellent characteristics such as

However, when producing 1q of positive-working waterless lithographic printing plates from the above-mentioned plate material, the development latitude is narrower than when obtaining negative-working waterless lithographic printing plates, and positive working and negative working are the same. It has the disadvantage that it cannot be carried out using a developing solution.

The inventors of the present invention have made extensive studies to improve these problems, and have found that the above problems can be satisfactorily solved by devising a plate-making method, and have arrived at the present invention.

[Problems to be Solved by the Invention] Therefore, an object of the present invention is to be able to significantly expand the development latitude even when obtaining a positive waterless lithographic printing plate, and to perform positive working and negative working in the same development process. It is necessary to provide a method for making a waterless lithographic printing plate that can be performed using a liquid.

[Means for Solving the Problems] It is an object of the present invention to provide a waterless lithographic printing plate comprising a support and a photosensitive layer containing a substance containing a quinonediazide structure and a silicone rubber layer in this order. Shun exposed to light, subjected to base treatment, and then fully exposed to light 1
This is achieved by a method for making a waterless lithographic printing plate, which is characterized by applying a development treatment.

The method for making a waterless lithographic printing plate of the present invention is particularly suitable for obtaining a positive type waterless lithographic printing plate.

The waterless lithographic printing plate used in the present invention is a known type having a photosensitive layer lined with a support and a 92-digit silicone rubber layer on the photosensitive layer.

In order to produce a positive type waterless lithographic printing plate from such a waterless lithographic printing plate, for example, the waterless lithographic printing plate having the above structure is subjected to image exposure using a positive film or a positive original, preferably in the image exposed area. The substance containing the quinonediazide structure in the photosensitive layer is exposed to light in an amount sufficient to photodecompose 5 to 60 mol% of the quinonediazide units, and then subjected to base treatment with an amine compound, etc., and then exposed to light, preferably photosensitive. A positive waterless lithographic printing plate of 1 q is obtained by exposing to light in an amount sufficient to photodecompose 6 to 10.0 mol% of the quinone diazide units containing the quinone diazide structure in the layer, followed by development treatment. I can do it.

In producing a positive waterless planographic printing plate from such a waterless planographic printing plate, base treatment and full surface exposure play an important 190%. In other words, when a base treatment is applied to a portion of a substance containing a quinonediazide structure that has been imagewise exposed so that 5 to 60 mol% of the quinonediazide units are photodecomposed, the adhesive strength with the silicone rubber layer above it is improved. , and its solvent resistance is also significantly improved, so even if the entire surface is exposed in the post-process and then developed, the silicone rubber layer on the photosensitive layer will not be removed and the photosensitive layer and silicone rubber layer will be separated. Both remain on the support and form a non-image area.

In addition, if the parts that were not exposed to image light are treated with a base,
On the contrary, the adhesive strength with the silicone rubber layer on top of the photosensitive layer decreases, and the solvent resistance of the photosensitive layer also decreases.The developability is greatly improved by subsequent full-surface exposure and development processing. The silicone rubber layer on the photosensitive layer or the silicone rubber layer and the photosensitive layer are easily removed to form an image area.

In this way, the difference in adhesive strength and the difference in solvent resistance between the photosensitive layer and the silicone rubber layer in the image-exposed area and the non-image-exposed area become larger, and the developability is greatly improved.
Expands development latitude.

In the present invention, the light source used in the image exposure step and the entire surface exposure step is one that generates abundant ultraviolet light, and examples include a mercury lamp, a carbon arc lamp, a xenon lamp, a metal halide lamp, a chemical lamp, and a fluorescent lamp. .

The support used in the present invention is not particularly limited, and those used in ordinary waterless lithographic printing plates or those that have been proposed can be used.

Examples include metal plates such as aluminum, iron, and zinc; transparent or opaque plastic films such as polyester, polyolefin, and polystyrene; and composites of both. 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. Contains quinonediazides.

Examples of such quinonediazides include esters of benzoquinone-1,2-diazide-4- or -5-sulfonic acid and polyhydroxyphenyl, and naph-1-quinone-1,2-diazide-4- or -5-sulfonic acid. Ester with pyrogallol acetone resin, naphthoquinone-1
, 2-diazide 4- or -5-sulfonic acid and phenol formaldehyde novolak resin or cashew-modified novolak resin. Also, low amounts of quinonediazide compounds (e.g. naphthoquinone-1,2
esters of -diazide-5-sulfonic acid with phenol, talezol, xylenol, catechol, pyrogallol, bisphenol A, etc.) or novolak resins that do not contain photosensitive groups in the resins containing the quinone diazide 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. Examples include 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-Dylene diisocyanate, 4,4'-diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, or their adducts, or polyfunctional epoxy compounds, such as polyethylene glycol diglycidyl ether There are polypropylene glycol diglycidyl ethers, bisphenol A diglycidyl ether, trimethylolpropane triglycidyl ether, etc. These thermal curing ranges within a range that does not cause loss of photosensitivity of the photosensitive material, usually 13
It is preferable to carry out the reaction at a temperature of 0° 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 may be graft-polymerized with a quinonediazide.

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

The thickness of the photosensitive layer is about 0.1 to 100 μm, preferably about 0
．． A suitable value is 5 to 10/m. If it is too thin, defects such as pinholes are likely to occur during coating, while if it 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.

Note that the amount of photodecomposition of quinonediazide units of a substance containing a quinonediazide structure in the above-mentioned image exposure or full-surface exposure treatment is 2200 to 2200, which is derived from the diazide group of quinonediazide in the photosensitive layer, as determined by infrared absorption spectrum (FT-IR-ATR method). The amount of change in absorption intensity (area intensity of absorption spectrum) in the 200 occm region due to exposure, ie, the amount of photodecomposition of diazide groups, was determined based on the value of the unexposed photosensitive layer.

Furthermore, the photodecomposition of quinonediazide referred to herein is generally referred to for quinonediazides, and is the change from quinonediazide to carboxylic acid due to exposure to light. For example, naphthoquinone-1,2-diazido-5-sulfonic acid and phenol formaldehyde novolac resin are indene carboxylic acids.

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

Here, n is an integer of 2 or more, and R and R' have 1 to 10 carbon atoms.
is an alkyl group, alkenyl group, or phenyl group, and those in which 60% or more of R and R' are methyl groups are preferred.

A crosslinking agent is usually added to this linear polysiloxane. As crosslinking agents, acetoxysilane,
There are ketooxime silanes, alkoxysilanes, aminosilanes, amidosilanes, etc., which are usually combined with linear organic polysiloxanes with hydroxyl groups at the ends, to produce one-party acetate type, deoxime type, dealcoholization type, deamine type, respectively.
It becomes a deamidated silicone rubber. A small amount of an organic tin compound or the like may be added as a catalyst to these silicone rubbers.

The appropriate thickness of the silicone rubber layer is about 0.5 to 100μ, preferably about 0.5 to 10μ; if it is too thin, problems may occur in terms of printing durability, while if it is too thick, it is not economical. Not only is this disadvantageous, but it is also difficult to remove the silicone rubber pouch during development, 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 extremely important and necessary for basic plate performance such as image reproducibility and printing durability. It is also possible to add adhesion-improving components. 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 plate precursor used in the present invention is produced, for example, as follows. First, coat the support with a conventional coater such as a reverse roll coater, air knife coater, Meyer bar coater, or a rotary coating machine such as a wheller.
Using a device, apply a composition solution to form the photosensitive layer, dry it, and if necessary heat cure it. If necessary, apply an adhesive layer on the photosensitive layer in the same manner, dry it, and then apply silicone gum. The solution is applied on the photosensitive layer or adhesive layer in a similar manner, and then heat-treated for several minutes at a temperature of usually 50 to 130°C.
Fully cure to form a silicone rubber layer. If necessary, cover the silicone rubber layer with a protective film using a laminator or the like.

In the present invention, bases used in the base treatment after image exposure include amine compounds (aliphatic chain amines, aliphatic cyclic amines, aromatic amines, tetracyclic amines, primary, secondary, tertiary amines, and monoamines). , diamine, triamine, tetraamine, polyamine, etc.). For example, ammonia, methylamine, ethylamine, dimethylamine, diethylamine, triethylamine, trimethylamine, propylamine, butylamine, amylamine, dipropylamine, dibutylamine, cyamylamine, tripropylamine, tributylamine, methyldiethylamine, ethylenediamine, trimethylenediamine, tetra Methylenediamine, polyethyleneimine, benzylamine, N,N-dimethylbenzylamine, N,N-diethylbenzylamine, N,N-
Dipropylbenzylamine, 0- or m- or p-
Methoxy or methylbenzylamine, N, N-di(
methoxybenzyl)amine 1, β-phenylethylamine, ε, δ-phenylamylamine, γ-phenylpropylamine, cyclohexylamine, aniline, monomethylaniline, dimethylaniline, toluidine, benzidine, α or β-naphthylamine, O or m- or p-Phenylediamine, pyrrolidine, piperidine, piperazine, morpholine, urothrobin, diazabicycloundecane, pyrrole, pyridine, quinoline, hydrazine, phenylhydrazine, N,N-diphenylhydrazine, hydroxylamine, urea, semicarbazide, thiourea, hydroxylated Tetraalkylammonium, monoethanolamine, N-methylethanolamine, N-ethylethanolamine, N-n-butylethanolamine, jetanolamine, triethanolamine, 2-(
2-aminoethyl) ethanol, 2-amino-2-methyl-1,3-propanediol, 2-amino-1,3-propanediol, 2-amino-2-hydroxymethyl-
1,3-propanediol, 3-hydroxypropylmethylamine, 4-hydroxybutylmethylamine, 3-
Methoxypropylamine, 3-■Toxypropylamine, 3-propoxypropylamine, 3-isopropoxypropylamine, 3-butoxypropylamine, 3-isobutoxypropylamine, 2-ethylhexyloxypropylamine, 2-ethoxy Ethylamine, 2-propoxyethylamine, 2-butoxyethylamine, 2-(
(aminoethoxy) ethanol, etc. are used.

These bases may be used alone or in a mixture, in liquid or gas phase. In liquid form, for example, the base itself,
Alternatively, it is used in the form of a solution.

When used as a solution, the solvent may be water, an organic solvent, or a mixed solution of both.

The processing method is to immerse the plate in a basic processing solution, or use a brush or pad to evenly wet the plate surface with the processing solution.
Alternatively, the plate surface can be wetted using a shower method, such as in an automatic developing machine.

The treatment time is not particularly limited and can be appropriately selected depending on the strength and concentration of the base used, but usually the effect is immediately apparent upon contact with the treatment solution, and there is no change in the effect even if the treatment solution is contacted for a long time. Usually it takes about 10 seconds to 5 minutes.

As the developer, those commonly proposed for waterless lithographic printing plates can be used. For example, water, the following polar solvents, and a mixture of water and the following polar solvents are suitable.

Alcohols (methanol, ethanol, etc.), ethers (ethyl cellosorbitol, butyl carpitol esters (cellosolve acetate, carpitol acetate, etc.).

[Example] The present invention will be specifically explained below using Examples.

Example 1, Comparative Example 1 Thickness Q. The following primer composition was applied to a 3 mm aluminum plate (manufactured by Sumitomo Light Metal Co., Ltd.) and heat treated at 200'C for 2 minutes to form a 5 μm thick primer layer.

■Polyurethane resin (Sunbren LQ-T1331, manufactured by Sanyo Chemical Industries, Ltd.) 100 parts by weight ■Blocked isocyanate (Takenate B8301, manufactured by Takeda Pharmaceutical Co., Ltd.)
20 parts by weight Epoxy phenol urea resin (SJ9372, manufactured by Kansai Paint Co., Ltd.) 8 parts dimethylformamide 725 parts by weight Subsequently, the following photosensitive layer composition was applied thereon using a bar coater. It was dried in hot air at 110° C. for 1 minute to form a photosensitive layer with a thickness of 2 μm.

■Partial ester of naphthoquinone-1,2-diazide-5-sulfonic acid and phenol formaldehyde novolac resin (Nisumilite Resin PR50622 manufactured by Sumitomo Durez) (degree of esterification 25% by elemental analysis method)
100 parts by weight ■ 40 parts by weight of 4,4°-diphenylmethane diisocyanate ■ 0.2 parts by weight of dibutyltin diacetate ■ 5 parts by weight of 4,4-diethylaminobenzophenone ■ P-toluenesulfone I O. 8 parts by weight - 800 parts by weight of tetrahydrofuran Next, a silicone rubber composition having the following composition was spin-coated onto the photosensitive layer and cured with moist heat at 115°C, dew point 30°C for 3.5 minutes to obtain a silicone rubber of 2.3 μm. Layers were set up.

■Polydimethylsiloxane (molecule old approx. 25, OOO, terminal OH group > 100 parts by weight ■Vinyltri(
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 10 μm thick polypropylene film “Trif 1” (manufactured by Toshiku Co., Ltd.) to the laminate obtained as above.
were laminated using a calendar roller to obtain a waterless lithographic printing original plate.

A positive film with a halftone image of 150 lines/inch was vacuum-adhered to the thus obtained waterless lithographic printing plate, and a chemical lamp (manufactured by Toko, Master Printer A3) was applied.
with an illuminance of 2.5 mW/Cm2 (U manufactured by Oak Seisakusho).
Image exposure was carried out for 30 seconds using a V meter (using a light measure type UV-402A).

Next, this plate was immersed in a base treatment solution consisting of "Isopar" H/butylcarpitol/ethyl cellosolve/N-methylethanolamine-871515/3 (weight ratio). After 1 minute, only the exposed areas turn brown.

Next, the plate was taken out from the processing solution, and after removing the base processing solution with a rubber squeegee, it was heated to 2.5 m using the chemical lamp mentioned above.
The entire surface was exposed for 2 minutes at an illuminance of W/cm2. Next, this plate was immersed for 1 minute in a developer consisting of water/butyl calpitol/2-ethylbutyric acid/crystalline violet = 70/30/210.2 (weight ratio), and rubbed lightly with a developing pad, resulting in image exposure. The silicone rubber layer in the unexposed areas is removed and the surface of the photosensitive layer is exposed to form an image area, but the silicone rubber layer in the image-exposed areas remains uncorroded by the developer and becomes a non-image area. A 1q print version of the image faithful to the original film was released.

This printing plate was printed on an offset printing machine (Hamada Star 500C).
DA) and printed using "Toyo King Ultra TKU Aquares G Eye PL II" manufactured by Toyo Ink Co., Ltd., and evaluated halftone dot reproducibility. 3 to 97% of halftone dots at 150 lines/inch were reproduced. A printed product with an extremely good image was obtained.

As a comparative example, a similar test was conducted on a printing plate made without only full-surface exposure, and the halftone reproducibility was 10~10.
The score was 85%, which was poor. Moreover, the developability was poor, and the development time was as long as 5 minutes, resulting in scratches on the silicone rubber layer in the non-image area.

Example 2, Comparative Example 2 Phenol formaldehyde novolak resin (Nisumilite Resin PR5, manufactured by Sumitomo Bakelite Co., Ltd.) 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,
After applying a 4% by weight dioxane solution (the degree of esterification was determined from an IR spectrum), it was dried at 60° C. for 3 minutes to obtain a photosensitive layer with a thickness of 1.8 μm. On top of this photosensitive layer, a silicone gum composition having the following composition: 7% "isopar+t"
In solution E, T-aminopropyltriethoxysilane (manufactured by UCC: A110
0) was added, stirred uniformly, and then coated with a Whaler. After drying, heat cure at 120℃, dew point 25℃ for 4 minutes to a thickness of 2.
．． A 2 μm silicone rubber layer was obtained.

■100 parts by weight of polydimethylsiloxane (approx. ao, ooo between molecules, OH groups at both ends) ■5 parts by weight of ethyltriacetoxysilane ■0.2 parts by weight of dibutyltin diacetate Waterless planographic printing obtained as above A positive film having a halftone image of 150 lines/inch was vacuum-adhered to the original plate, and imagewise exposed for 60 seconds using the chemical lamp used in Example 1 at an illuminance of 2.5 mw/cm 2 . The exposed plate is immersed in a base treatment solution consisting of propatool/monoethanolamine-9515 (weight ratio), and after the image-exposed area turns brown, the base treatment solution is removed and the plate is exposed to the chemical lamp described above. 2.5mW/cm2
The entire surface was exposed to light for 3 minutes at an illuminance of .

Next, when the developing pad is soaked with a developer (ethanol) and the plate surface is lightly rubbed, the silicone rubber layer and photosensitive layer in the areas that were not exposed to the image are removed, exposing the aluminum surface and forming the image area, but the area that has not been exposed to the image is removed. The silicone rubber layer in the exposed areas was strongly adhered and remained, resulting in non-image areas.

This printing plate was attached to the same offset printing machine as in Example 1, and the “Toyo King Ultra TKU” manufactured by Toyo Ink Co., Ltd.
When printed using “Aquares G iPL”,
Prints with good images were obtained in which 5 to 95% of the halftone dots at 150 lines/inch were reproduced.

As a comparative example, when a similar test was conducted on a printed matter that was plate-made without only full-surface exposure, the halftone reproducibility was 10~10.
It was 80% bad. Moreover, the developing time was as long as 7 minutes.

Reference Example This reference example shows that negative working can be carried out using the same developer as that used in positive working in Example 1.

That is, using the chemical lamp used in Example 1, the waterless lithographic printing plate obtained in Example 1 was heated at 2°5 mw/cm2.
The entire surface was exposed to light for 15 seconds at an illuminance of . Next, a negative film with a halftone image of 150 lines/inch was vacuum-adhered,
Exposure was performed for 2 minutes using a chemical lamp at an illuminance of 2.5 mW/cm2.

Subsequently, after immersing the plate in the basic processing solution used in Example 1 for 1 minute, the plate was taken out, and after removing the basic processing solution with a rubber squeegee, it was immersed in the developing solution used in Example 1 and rubbed lightly with a development pad to form an image. The exposed portions of the silicone rubber layer were removed to expose the surface of the photosensitive layer. On the other hand, the silicone rubber layer remained firmly in the portions that were not imagewise exposed, and a negative working image was obtained.

This printing plate was printed in the same manner as in Example 1, and the halftone dot reproducibility was evaluated.
~97% was reproduced.

[Effects of the Invention] The plate-making method according to the present invention has the advantage of good developability and wide development latitude even when applied to positive working. Further, practical effects such as being able to process positive working and negative working with the same developer can be expected.

Patent applicant: Toshi Co., Ltd.

Claims (1)

[Claims] (1) A waterless lithographic printing plate consisting of a support, in which a photosensitive layer containing a substance containing a quinonediazide structure and a silicone rubber layer are provided in this order, is subjected to image exposure, then subjected to base treatment, and then subjected to full-surface exposure. A method for making a waterless lithographic printing plate, which comprises performing a development treatment after the application.