JPH03249651A - Dampening-waterless planographic printing plate material - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a lithographic printing plate material that does not require dampening water, and in particular, plate inspection properties (ease of viewing images after dyeing), safelight properties (white color This invention relates to a lithographic printing plate material that does not require dampening water and is easy to handle under light.

[Conventional technology]

Traditionally, negative-working lithographic printing plate materials do not require dampening water.

Generally, a support has a primer layer, a photosensitive layer, and a silicone rubber layer, and a naphthoquinone diazide compound is used as a photodegradable component in the photosensitive layer (Japanese Patent Publication No. 54222/1983, No. 61 54223), 1,2-naphthoquinone-2-diazide-5-sulfonic acid compounds have been used as such naphthoquinone diazide compounds. Such a printing plate material is exposed (baked) and developed to remove the silicone rubber layer and photosensitive layer in the exposed areas, expose the primer layer, and form a printing plate with recessed image areas formed.

These printing plates are further dyed so that the image areas appear clearly.

[Problem to be solved by the invention]

However, when a 1,2-naphthoquinone-2-diazide-5-sulfonic acid compound is used in the photosensitive layer, the photosensitive layer in non-image areas has a strong yellowish tinge. When stained with a blue staining solution commonly used in
The drawback was that it was difficult to see the printed lines on the plate.

In addition, when a photosensitive layer is made using a 1,2-naphthoquinone-2-diazide-5-sulfonic acid compound, the resulting plate material is easily sensitive to white fluorescent light, but white fluorescent light is generally used in the exposure and development work areas. However, when exposed and developed under such a white fluorescent lamp, unnecessary exposure occurs and fogging tends to occur, that is, the safelight property is poor.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a lithographic printing plate material that does not require dampening water, in which image areas after dyeing are easy to see and fogging does not easily occur even when exposed under white fluorescent lamps.

[Means to solve the problem]

As a result of intensive studies to achieve the above object, the inventors have arrived at the present invention.

That is, the dampening water-free lithographic printing plate material according to the present invention has a primer layer, a photosensitive layer, and a silicone rubber layer in this order on a support, in which the photosensitive layer has a thickness of 1.2 -Naphthoquinone-2-diazide-4-sulfonic acid ester compound.

[Effect]

The lithographic printing plate material that does not require dampening water of the present invention uses a 1.2-naphthoquinone-2-diazide-4-sulfonic acid ester compound in the photosensitive layer instead of a 1.2-naphthoquinone-2-diazide-5-sulfonic acid compound. Of the photosensitive layer and silicone rubber layer that remain as non-image areas, the silicone rubber layer is transparent, so the appearance of the non-image areas is the appearance (color) of the photosensitive layer.
ruled by. However, the photosensitive layer containing 1,2-naphthoquinone-2-diazide-4-sulfonic acid ester compound has less yellowish tinge, that is, the appearance of the printing plate itself has less yellowish tinge.Therefore, the image area was dyed blue. In this case, the blue color in the printed area is easy to see due to the appearance of the printing plate itself, and the absorption wavelength of the printing plate is on the short wavelength side, so it is difficult to see the light from white fluorescent lamps.
Therefore, fogging is less likely to occur and safelight properties are improved.

[Structure of the invention]

The present invention will be explained in detail below.

The lithographic printing plate material that does not require dampening water (hereinafter also referred to as a plate material that does not require dampening water or simply a plate material) of the present invention includes, for example, a primer layer, a photosensitive layer, It has a silicone rubber layer, and may have a releasable light-transmitting film layer if necessary.

The support is preferably flexible enough to be set in a normal lithographic printing machine and capable of withstanding the load applied during printing. For example, aluminum is preferable.

Metal plates such as zinc, copper, and steel, metal plates plated or vapor-deposited with chromium, zinc, copper, nickel, aluminum, iron, etc., paper, plastic films, glass plates, resin coated paper, and metal foils such as aluminum. Examples include stretched paper, hydrophilized plastic film, and the like. Among these, aluminum plates are preferred. When an aluminum plate is used, it may be subjected to surface roughening treatment such as grain leveling treatment and anodizing treatment.

The thickness of the support is preferably 50 to 400 μm, more preferably 100 to 300 pm.

A photocurable primer containing a photosensitive resin or a photoreceptor is preferably used for the primer layer. In addition to the photosensitive resin and the photoreceptor, this photocurable primer may contain a binder resin, a white pigment, and a yellow pigment.

The photosensitive resin or photoreceptor used in the photocurable primer is a diazo resin or a photopolymerization initiator and a polymerization polymer.
Combinations of the following can be mentioned.

Examples of the binder resin include polyester, vinyl chloride resin, polyamide resin, polyvinyl butyral resin, epoxy resin, acrylic copolymer, vinyl acetate copolymer, phenoxy resin, polyurethane resin, polycarbonate resin, and synthetic rubber. Among these, acrylic resins, polyurethane resins, and epoxy resins are particularly preferred.

As the white pigment, titanium oxide, zinc oxide, barium sulfate, calcium carbonate, or these pigments surface-treated with a silane coupling agent, a surfactant, etc. can be used.

Although various commercially available pigments can be used as the yellow pigment, benzimidacylon yellow pigments are particularly preferred.

The photosensitive layer is 1,2-naphthoquinone-2-diazide-4-
Sulfonic acid ester compound (hereinafter referred to as "compound of the present invention")
).

The compound of the present invention is a polycondensation resin of phenols and aldehydes or ketones, a partial ester compound of phenols and 1,2-naphthoquinone-2-diazide-4-sulfonic acid, or a polyfunctional ester compound of these partial ester compounds. It is a compound obtained by crosslinking or modification with a monofunctional isocyanate.

Examples of the phenols include monohydric phenols such as phenol, cresol, 3,5-xylenol, carvacrol, and thymol, dihydric phenols such as catechol, resorcinol, and hydroquinone, pyrogallol, and phloroglucin.

Examples of the aldehyde include formaldehyde, benzaldehyde, acetaldehyde, crotonaldehyde, and furfural. Among these, formaldehyde and benzaldehyde are preferred.

Examples of the ketone include acetone and methyl ethyl ketone.

Specific examples of the polycondensation resin include phenol formaldehyde resin, cresol formaldehyde resin, pyrogallol acetone shelf, and the like.

1 for the OH group of the phenol of the compound of the present invention
The condensation rate of 2-naphthoquinone-2-diazido-4-sulfonic acid (reaction*) to COHOH groups is preferably 15 to 80%, more preferably 20 to 60%.

The proportion of the compound of the present invention in the photosensitive layer composition (excluding the solvent) is preferably 5 to 100% by weight, particularly preferably 20 to 95% by weight.

Further, a binder resin can also be used in the photosensitive layer composition. As such binder resin, chlorinated polypropylene, cresol novolac resin, or methacrylic copolymer containing a group consisting of hydroxyphenyl methacrylate as a constituent part can be preferably used. The blending amount of the binder resin is preferably 5 to 95% by weight, more preferably 5 to 80% by weight in the photosensitive layer composition (excluding the solvent).

In the present invention, the photosensitive layer composition may further contain fillers, dyes, dyes, pigments, surfactants for improving coating properties, and other commonly used additives and auxiliaries.

The thickness of the photosensitive layer is preferably 0.1 to 100 mg/da2, more preferably 1 to 50 mg/da2.

The silicone rubber used in the silicone rubber layer is mainly composed of a linear organic polysiloxane having the following repeating units, a molecular weight of several thousand to several hundred thousand, and an OH group in the main chain or at the end of the main chain. Preferably.

(-S+ -0+l+ (where n is an integer of 2 or more, R is an alkyl group having 1 to 10 carbon atoms, a halogenated alkyl group, a vinyl group, an aryl group,
Preferably, it is a silanol group (OH group), and 60% or more of H is a methyl group.

The silanol group (OH group) may be located either in the main chain or at the end of the main chain, but is preferably located at the end.

The silicone rubber useful in the present invention is obtained by a condensation reaction between such a silicone base polymer and a silicone crosslinking agent as listed below.

(1) R-3i (-OR") (2) R-5i (-CIAc) (3) R-5i 1,000ON<R' 2) 2 Here, R has the same meaning as R explained earlier, R' is an alkyl group such as a methyl group or an ethyl group, and AC is an acetyl group.

These silicone rubbers are also available as commercial products, such as YE-3085 manufactured by Toshiba Silicone Corporation.

Other useful silicone rubbers can be produced by reacting the above-mentioned pace polymers with silicone oils having the following repeating units, or by reacting them with silicone base polymers in which about 3% of R is vinyl groups. addition reaction,
Alternatively, it can also be obtained by a reaction between the silicone oils.

(In the formula, R has the same meaning as R above, ■ is an integer of 2 or more, and n is O or an integer of 1 or more.) In order to obtain silicone rubber by such a crosslinking reaction, the above-mentioned In addition to the ingredients, organic carboxylates of metals such as tin, zinc, cobalt, lead, calcium, manganese, etc., such as dibutyltin laurate, tin(n) octoate, cobalt naphthenate, etc., or catalysts such as chloroplatinic acid. is added.

In addition, in order to improve the strength of silicone rubber and obtain silicone rubber that can withstand the frictional forces generated during printing operations,
Fillers can also be mixed. Silicone rubber premixed with fillers is commercially available as silicone rubber stock or silicone rubber dispersion.

In the present invention, condensation and crosslinking type silicone rubber can be used.

In the present invention, in addition to the above-mentioned components, a small amount of photosensitizer can be included in the silicone rubber layer.

Preferably, the silicone rubber layer further contains a silane coupling agent to improve adhesion to the photosensitive layer.

Examples of silane coupling agents include the following.

(a) H2NC:H2CH2NHCC:H2CH2C
H2S1(OCH3)3(b) CH2CHCH20(
CHzhSi(QC)I3h\1 (c) H5(C:H2)3Si(OCH3h(d)
CH2 禦CH31(OCOCH3)3(e) CH2
=C-C00(GHz)3Si(OCH3hH3 (f) GHz<H5i(OCOCH3h(g)H2C
H2CH2S1(CHzhSi(OCH3)2((:H
3) The thickness of the chlorosilane silicone rubber layer (h) is preferably 0.1 to 10 JLm, more preferably 0.5 to 2 #Lm.

Examples of resins used in the light-transmitting film layer include polyolefins such as polypropylene, polyethylene, polymethylpentene, and ethylene-butene copolymers, polystyrene, fluororesins, polyethylene terephthalate, nylon, polyvinyl alcohol, polycarbonate, polymethyl methacrylate, and polyimide. , polyacrylonitrile, etc. can be used.

The thickness of the light-transmitting film layer is preferably 0.5 to 20 mm, more preferably 3 to 8 mm.

Next, an example of a method for producing a dampening water-free plate material of the present invention will be explained.

A primer layer composition solution is applied onto the support using a normal coater such as a reverse roll coater, an air knife coater, a Mayer percoater, or a rotary coating device such as a Whaler, and then dried to form a primer layer. A photosensitive layer composition solution is applied thereon in the same manner and dried to form a photosensitive layer.Next, if necessary, an adhesive layer is formed on the photosensitive layer in the same manner, and a silicone rubber solution is applied on top of this. is applied in the same manner, usually 100 to 1
Heat treatment is performed at a temperature of 20° C. for several minutes to fully cure the silicone rubber layer. Then, a light-transmitting film is laminated on the silicone rubber layer.

A method for manufacturing a printing plate that does not require dampening water from the above-mentioned plate material will be explained.

The original negative film is vacuum-adhered to the plate surface and exposed.

After exposure, the light-transmissive film is peeled off and developed with a developer to remove the silicone rubber layer and photosensitive layer in the exposed areas.
The primer layer is exposed in the image area. In this way, a printing plate in which a recessed image portion is formed can be obtained.

Furthermore, staining is performed so that the image area appears clearly. The staining liquid used here is usually a blue staining liquid in order to make the printed area easier to see.

〔Effect of the invention〕

According to the present invention, instead of the conventionally used 1,2-naphthoquinone-2-diazide-5-sulfonic acid compound,
1. Since the photosensitive layer contains a 2-naphthoquinone-2-diazide-4-sulfonic acid ester compound, the printing plate obtained by development and exposure has less yellowish tinge, and the image after dyeing is easy to see, that is, plate inspection properties are improved. In addition, since the absorption wavelength of the printing plate material is on the short wavelength side, it is less sensitive to light from white fluorescent lamps and fogging is less likely to occur, that is, safelight properties are improved.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples.

The degreased and cleaned aluminum plate was anodized in a 40 wt% sulfuric acid aqueous solution at 30°C and 1.5 A/drn' for 2 minutes, washed with water, and then anodized in a 1 wt% sodium silicate aqueous solution at 85°C for 25 seconds. The substrate was treated with sodium silicate and then washed with water to obtain Substrate-1.

Next, a primer layer composition having the following composition was applied onto this substrate using a wire bar, and dried at 80° C. for 2 minutes to provide a primer layer. Weight after drying is 60g/d
It was rrf.

(Primer layer composition) ■2-hydroxy methacrylate/methyl methacrylate (80/20) copolymer 100
Part ■ PF6 salt of condensate of p-diazodiphecolamine and formaldehyde 10 parts ■ Seiryoku Fast Yellow) 17055 5 parts ■ Methyl cellosolve 1000 parts The obtained primer layer was coated with 400 layers using a metal halide lamp.
It was irradiated with ultraviolet light of /cm' and photocured.

A photosensitive liquid having the following composition-1 was applied onto the primer layer using a wire bar and dried at 90°C for 2 minutes.

(Photosensitive liquid composition-1) ■33%1 of cresol novolak resin (MW900)
．． 2-naphthoquinone-2-diazide-4-sulfonic acid ester 100 parts ■ 4,4°-diphecolmethane diisocyanate 20 parts ■ Methyl cellosolve 1100 parts ■ Victoria Pure Blue BOH 5 parts After drying, 12
A photosensitive layer having a thickness of 5 parts g/d was formed by heat treatment at 0° C. for 2 minutes.

Furthermore, photosensitive solutions of Groups I & -2 below were applied onto the same brimer layer using a wire bar and dried at 90° C. for 2 minutes to form a photosensitive layer having a thickness of 5 parts g/dd.

(Photosensitive liquid composition-2) ■33% of cresol nopolar 2 resin (MW900)
1.2-naphthoquinone-2-diazide-4-sulfonic acid ester compound 25 parts ■Chlorinated polypropylene (manufactured by Dezumi Kokusaku Pulp Co., Ltd.) 75 parts■Dioxane 900 parts■
Victoria Pure Blue BO) 4 parts After applying a silicone rubber layer having the following composition on the two types of photosensitive layers obtained and drying it at 80°C for 5 minutes, a polypropylene strength bar film (thick) with corona treatment on one side was applied. Sa6
4m ) was laminated and further dried at 55° C. for 24 hours to prepare photosensitive lithographic printing plate samples A and B that do not require dampening water. (A is photosensitive liquid composition -1, B is photosensitive liquid composition -2) (Silicone rubber layer composition liquid) ■YF-3807 (manufactured by Toshiba Silicone Corporation) ■Triacetoxymethylsilane ■Dibutyltin dilaurate ■Isoper E (manufactured by Exxon Corporation) ) 100 parts 10 parts 0.8 parts 2000 parts In addition, in photosensitive liquid compositions 1 and 2, 1,2-naphthoquinone-2-diazide-5-sulfonic acid ester of Talesol novolak resin (MW900) was used. Comparative sample C (photosensitive liquid composition-1) was prepared using a photosensitive liquid with exactly the same composition.
A comparative sample D (photosensitive liquid composition-2) was prepared.

(Evaluation of safelight property) The obtained sample was exposed to a 400 lux white fluorescent lamp for 10 minutes. Then, after soaking in n-hebutane for 5 minutes,
I rubbed it lightly with gauze.

For samples A and B, the silicone rubber layer in the image area was completely peeled off.
I was able to develop it completely. However, in comparative samples C and D, the silicone layer did not peel off partially and was exposed to light from a white fluorescent lamp.

(Evaluation of plate inspection properties) Negative film was applied to the obtained samples A, B, C, and D under vacuum, and exposed with a metal halide lamp.Then, the polypropylene cover film was peeled off, and the samples were soaked in n-hebutane for 5 minutes. After immersion, it was rubbed lightly with gauze and developed, and then the image area was stained blue.

Was it easy to see the blue color in the image area for samples A and B? Comparative sample C
, D used to have a yellowish color in the non-printed areas, and the blue color in the printed areas was difficult to see due to the yellowish color.

teenager Reason Man

Claims (1)

[Claims] In a lithographic printing plate material that does not require dampening water and has a primer layer, a photosensitive layer and a silicone rubber layer in this order on a support,
The photosensitive layer is 1,2-naphthoquinone-2-diazide-4-
A lithographic printing plate material that does not require dampening water and is characterized by containing a sulfonic acid ester compound.