JPH043164A - Damping waterless planographic printing plate material - Google Patents

Abstract

PURPOSE:To improve both of visible image formability by exposing and visible image formability by developing by incorporating dyes which are increased in absorbance at 400 to 700nm by an acid and are recolored in a developing process into photosensitive layer. CONSTITUTION:The photosensitive layer of the dampening waterless photosensitive planographic printing plate material which has a primer layer, the photosensitive layer and a silicone rubber layer in this order on a base and is processed by an aq. alkaline developer contains the dyes which are increased in absorbance at 400 to 700nm by the acid and are recolored in the developing process. The dyes which are increased in absorbance at 400 to 700nm by the acid and are recolored in the developing process are exemplified by azo dyes, such as pentamethoxy red and metanyl yellow, among which the orange IV and methanyl yellows are more preferable. Both of the visible image formability by exposing and the visible image formability by developing are improved in this way.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a photosensitive lithographic printing plate material that does not require a dampening solution, and more specifically, a photosensitive material that does not require a dampening solution and has excellent exposure visible image properties and development visible image properties. Planographic printing plate materials.

[Background of the invention]

Conventionally, the photosensitive layer contains a compound that generates acid when exposed to light, and a dye that fades with # is used to fade the exposed areas, making it possible to distinguish between the unexposed areas and the exposed areas (exposed visible image). is known to confer gender).

Blue pigments such as Victoria Pure Blue BOH and oil blue are used as pigments that fade with acids.
It provided exposure visibility. When using such a dye that fades with acid, there is a problem in that when developed with an aqueous alkaline developer, the faded color is restored, resulting in poor visible image quality when developed.

SUMMARY OF THE INVENTION An object of the present invention is to provide a photosensitive lithographic printing plate material that does not require dampening water and is excellent in both exposed visible image properties and developed visible image properties.

Means for Solving Problem 1] As a result of intensive studies to achieve the above object, the inventor of the present invention found that when using a dye that develops color with acid and fades with alkali, the visible image quality upon exposure and the visible image quality during development are improved. It was discovered that a good plate material could also be obtained by using this method, leading to the present invention.

Specifically, the photosensitive lithographic printing plate material according to the present invention that does not require dampening water has a primer layer, a photosensitive layer, and a silicone rubber layer in this order on a support, and does not require dampening water and is treated with an aqueous alkaline developer. Achieved by a photosensitive lithographic printing plate material that does not require dampening water, in which the photosensitive layer contains a dye that increases absorption in the 400 to 700 nm range with acid and restores color during the development process. be done.

It has also been found that the above object can be achieved more effectively by including a dye in the primer layer which increases intestinal absorption by 400 to 700 nm with acid and restores color during the development process.

The present invention will be explained in detail below.

The dampening water-free plate material of the present invention has a primer layer on the support,
A photosensitive layer and a silicone rubber layer are formed. The photosensitive layer and the silicone rubber layer are made of one layer of photosensitive silicone rubber.
, a layer, or an adhesive layer may be provided between the photosensitive layer and the silicone rubber layer.

(Photosensitive layer) Dyes that increase the absorption of 400 to 700 tv with acid and recover their color during the development process include pentamethoxy red, methanyl yellow, methyl yellow, orange ■, ethyl orange, naphthyl red, brilliant yellow, α
- Naphthol Orange, α-Naphthol Hensein, P
Examples include azo dyes such as -methyl red, p-aminoazobenzene, and 4-phecolazodiphenylamine, but among these, orange (2) and methanyl yellow are preferred.

The content of the dye is 1 to 20 per 100 parts by weight of the photosensitive layer composition.
The amount is preferably 31 parts by weight, and more preferably 1 to 10 parts by weight.

The structure of the photosensitive layer of the present invention is not particularly limited, and various photosensitive substances can be used. Typical examples will be explained below.

First, quinonediazide-type positive photosensitive materials such as conventionally known 0-naphthoquinonediazide compounds are mentioned.

Suitable 0-naphthoquinone diazide compounds include naphthoquinone-(1,2)-diazide=(2)-sulfonic acid chloride and phenol or cresol-formaldehyde resins described in U.S. Pat. No. 3,046,120. There is an ester with. As the 0-naphthoquinone cyacyto compound for the ground fabric, for example, US Pat.
, ester of Piagalo-Ruer heptone resin and 0-naphthoquinonediazide sulfonic acid chloride described in JP-A-55-7B346, JP-A-55-7B346, JP-A-55-7B346, JP-A-55-7B346;
Ester of polyhydroxyphenyl resin and 0-naphthoquinonediazide sulfonic acid chloride described in No. 1044 and No. 56-1045, JP-A-50-11
A homopolymer of p-hydroxystyrene as described in No. 3305 or a copolymer of p-hydroxystyrene with other copolymerizable monomers is subjected to an ester reaction with 0-naphthoquinonediazide sulfonic acid chloride. 49
- A polymer product of a styrene monomer and a phenol derivative as described in No. 17481. - reaction products with quinonediazide sulfonic acid, and esters of polyhydroquinohensiphenone and O-naphthoquinonediazide sulfonic acid chloride.

A binder may be added to a photosensitive composition containing such a quinonediazide type photosensitive substance, if necessary.
For example, suitable examples include Noporafuku resins soluble in aqueous alkaline solutions. Representative examples of such nopolofuku resins include phenol-formaldehyde resin, cresol-formaldehyde resin, P-tert-butylphenol-formaldehyde resin, and phenol-modified xylene resin.

The amount of quinonediazide compound in the photosensitive composition is 10-5
It is 0% by weight, more preferably 20 to 40% by weight. In addition, the amount of the above-mentioned binder is 45 to 45% in the photosensitive composition.
80% by weight, preferably 50-70%! The amount of Ir is %.

Further, as the photosensitive substance, a diazo resin typified by a condensate of an aromatic diazonium salt and formaldehyde is also used.

Particularly preferred are salts of condensates of p-diazodiphenylamine and formaldehyde or acetaldehyde, such as hexafluorophosphates, tetrafluoroborates,
A diazo resin inorganic salt which is a reaction product of a perchlorate or a periodate and the above-mentioned condensate;
Examples include diazo resin organic salts, which are reaction products of the above condensate and sulfonic acids, as described in No. 309. The diazo resin is preferably used together with a binder. Various polymer compounds can be used as such a binder, but monomers 1 having an aromatic hydroxyl group as described in JP-A No. 54-98813, such as t(4-hydroxyphenyl), are preferably used. Copolymer of acrylamide, N-(4-hydroxyphenyl)methacrylamidone, 0-, 0-, or P-hydroxyphenylenemethacrylate, etc. with other monomers, US Pat. No. 4,
Polymers containing hydroxyethyl acrylate units or hydroxyethyl methacrylate units as the main repeating units, as described in No. 123,278;
Natural resins such as Sierra Fuku, Ojin, etc., polyvinyl alcohol 2, polyamide resins described in U.S. Pat. No. 3,751,257, linear polyurethane resins described in U.S. Pat. These include celluloses such as tare resin, epoxy resin condensed from bisphenol A and epichlorohydrin, cellulose acetate, and cellulose acetate phthalate.

-CH= as a photosensitive group in the main chain or side chain of the polymer
Also included are those whose main component is a photosensitive polymer such as polyesters, polyamides, and polycarbonates containing CH-C-. For example, a photosensitive polyester obtained by condensing phenylene diethyl acrylate with hydrogenated bisphenol A and triethylene glycol, as described in JP-A-55-40415;
Examples include photosensitive polyesters derived from (2-properidene) malonic acid compounds such as cinnamylidene malonic acid and difunctional glycols, as described in U.S. Pat. No. 2,956,878. .

Further examples include aromatic azide compounds in which the azide group is bonded to an aromatic ring directly or via a carbonyl group or a sulfonyl group. For example, polyazidostyrenes as described in U.S. Pat. Reaction products of sulfanyl chloride and unsaturated hydrocarbon polymers, and 210 ft.
Examples include polymers containing sulfonyl azide or carbonyl azide, as described in No. 7, No. 44-229, No. 44-22854, and No. 45-24915.

Furthermore, a photopolymerizable composition comprising an addition polymerizable unsaturated compound may also be mentioned.

In the present invention, the photosensitive material may further include fillers, dyes and dyes other than the present invention, surfactants for improving coating properties, and other commonly used additives, as long as they do not impair the purpose of the present invention. It may contain auxiliary agents.

The thickness of the photosensitive layer is preferably 0.05 to 10μ, more preferably 0.0μ. i~2 μm.

(Support) The support is preferably one that is flexible enough to be set in a normal lithographic printing machine and that can withstand the load applied during printing, such as aluminum, zinc tricopper, etc. Metal plates such as steel, metal plates plated or vapor-deposited with chromium, zinc copper, nickel, aluminum, iron, etc., paper, plastic films and glass plates, resin coated paper, paper covered with metal foil such as aluminum, Examples include plastic films that have been treated with wood. Among these, aluminum plates are preferred. When using an aluminum plate. Surface roughening treatment such as graining treatment and wA polar acid oxidation treatment may be performed.

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

(Primer layer) The primer layer preferably contains a resin, a curing agent if necessary, various additives, a silane coupling agent, and an organic titanate agent.

As the resin, for example, polyester resin, vinyl chloride
Vinyl acetate copolymer, acrylic resin, vinyl chloride resin,
Examples include polyamide resin, polyvinyl butyral resin, epoxy resin, acrylate copolymer, vinyl acetate copolymer, phenoxy resin polyurethane resin, polycarbonate resin, polyacrylonitrile butadiene, polyvinyl acetate, and the like.

In the primer layer used in the present invention, it is preferable to crosslink it in order to improve the solvent resistance to the coating solvent of the photosensitive layer and the organic solvent in the developer. Preferably, it is more preferably cured by light.

As the component to be crosslinked, polyvalent isocyanate compounds, diazo resins, polyvalent epoxy compounds, compounds having two or more polymerizable ethylenically unsaturated double bonds, and the like are used. Examples of polyvalent incyanate compounds include 1, for example, diphenylmethane-4,4'-diisocyanate, hexamethylene diisocyanate, coronate E, )IL,
E)+ (manufactured by Nippon Polyurethane Kogyo Co., Ltd., polyvalent incyanate compound), and the like.

The diazo resins include 4-diazodifecolamine, hexafluorophosphate-formaldehyde resin, 3-methoxy-diphenylamine-4-diazonium salt and 4.4'-
Examples include mesitylene sulfonate salt of a condensate of bis-methoxymethyl-diphenyl ether.

Examples of the polyvalent epoxy compound include bisphenol epoxy resin, bisphenol F diglycidyl ether, novolac glycidyl ether, hexahydrophthalic acid glycidyl ether, triglycidyl isocyanurate, and the like.

Examples of the compound having two or more polymerizable ethylenically unsaturated double bonds include trimethylolpropane triacrylate, tetramethylolmethane triacrylate, allyl acrylate, and 1,4-butanediol dimethacrylate. In addition, when using a compound having an ethylenically unsaturated double bond, a polymerization initiator or a photopolymerization initiator is used together.

(Silicone Rubber Layer) The silicone rubber used in the silicone rubber layer is 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, the main component is

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 R is a methyl group.

The silanol group (0) 1 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 the condensation reaction of this unique silicone haze polymer with the following silicone crosslinking agent.

(1) R-Si(-OR') (2) R-Si%0Ac) (3)! ? -5Yi-(1-ON-C:R'2)2 Here, R has the same meaning as R explained above, R' is an alkyl group such as a methyl group or an ethyl group, and AC is an acetyl group. It is.

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 base polymers listed above with silicone oils having the following repeating units, or by reacting 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.

RR (In the formula, R has the same meaning as R above, 1M is an integer of 2 or more, and n is an integer of 0 or 1 or more.) In order to obtain a silicone rubber by such a crosslinking reaction, In addition to the above two ingredients, organic carboxylic acid salts of metals such as tin, zinc cobalt, calcium, manganese, etc., such as dibutyltin laurate, tin(IT) octoate, cobalt naphthenate, etc., or chloroplatinic acid, etc. A catalyst 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 pre-mixed with filler is commercially available as silicone rubber stock or silicone rubber dispersion, and when it is preferable to obtain a silicone rubber film by coating as in the present invention,
RT V or +i L T V silicone rubber dispersions are preferably used. An example of this is Syl Off 23.5R manufactured by h-Resilicone.
There are silicone rubber dispersions for Haha coating such as X-257SH237.

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) IbNC:H2CToN)Ice)I2OH2
CH2Si(OCIbb(b) C)12cHcH20
(Cfb'hSi(OCH3)3(c) HS(GHz
)3si(OCH3)x(d) C)Iy=CHSi(
QC:0fll:H3h(e) CTo=(knee C00
(C)lz)3Si(OCH3):+H3 (f) CHr<)ISi(OGToCHx)a(g)
)12NcH2cH2NH(OH2)xSi(QC)
lx)2(C)I3)(h) The thickness of the chlorosilane silicone rubber layer is preferably 0.1 to 10 μm, more preferably 0.5 to 2 μm.

Note that in the case of forming a photosensitive silicone rubber layer, a photosensitive layer is not necessary, and as such a photosensitive silicone rubber, γ-methacryloxypropyltrimethoxysilane or monocinnamoyljetoxysilane is added to the terminal OH group of dimethylpolysiloxane. Examples include compounds obtained by dealcoholization condensation of , or compounds obtained by adding a bisazide compound to polydiocasiloxane, or reacting acryloyl chloride or p-azidobenzoate.

A light-transmissive film layer can be formed on the silicone rubber layer. Here, light transmittance refers to, for example, active light (wavelength 30
A light transmittance of 50% or more with respect to 0 nm to 500 nm).

Examples of resins used in the light-transmitting film layer include polyolefins such as polypropylene-4-polyethylene, polymethylpentene, and ethylene-butene copolymers, polystyrene, fluororesins, polyethylene tyrephthalate, nylon, polyvinyl alcohol, polycarbonate, and polyethylene. Examples include methyl methacrylate, polyimide, polyacrylonitrile, and the like.

The light-transmissive film layer may be a single layer of the resin film described above, or may be a laminated film of two or more layers.

The thickness of one layer of the light-transmitting film layer is 0.5-204
m is preferred, and more preferably 3 to 8 nights.

The light-transmitting film layer is preferably matted.

Next, a method for manufacturing the above plate material will be explained.

A composition solution to form a primer layer is applied onto a support using a conventional coater such as a reverse roll coater, an air knife coater, a Meyer bar coater, or a rotary coating device such as a Whaler, and then dried. Apply a composition solution on top of the photosensitive layer and dry it. 6. Next, if necessary, apply an adhesive layer on the photosensitive layer in the same manner. After drying, 5. Apply a silicone rubber solution on the adhesive layer in the same manner. The silicone rubber layer is then coated and heat treated at a temperature of usually 100 to 120° C. for several minutes to fully cure the silicone rubber layer.6 A light-transmitting film is then laminated onto the silicone rubber layer.

Next, a method for manufacturing a printing plate that does not require dampening water using the plate material of the present invention will be described.

An original, for example, a positive film, is aligned with the surface of the plate material that does not require dampening water, is vacuum-adhered, and exposed. As a light source for this exposure, a mercury lamp, a carbon arc lamp, a xenon lamp, a metal halide lamp, a fluorescent lamp, etc., which generate abundant ultraviolet light, are used. After exposure, when the light-transmitting film is peeled off and developed with an aqueous alkaline developer, only the silicone rubber layer and the photosensitive layer or the silicone rubber layer in the unexposed areas are removed, forming a concave image area as shown in 0 or more. You can obtain a printed version.

The aqueous alkaline developer used in the present invention preferably has a pH of 12 or higher.

As the alkaline agent, silicates and other alkaline agents are used.

The preferred one is Kei 11! 1! It, and the composition of silicon salt is [5iOz] / [M] = 0.5-1.
5 and has 0.8 to 8% of 5i02.

Here, [5i02] is the molar concentration of 5iOz, and [M] is the molar concentration of the total alkali metal.

Examples of the silicates include potassium silicate, sodium silicate, sodium metasilicate, potassium metasilicate, ammonium silicate, and lithium silicate.

Alkali agents other than silicates include potassium trihydroxide, sodium hydroxide, sodium phosphate, sodium diphosphate, potassium phosphate, potassium diphosphate, ammonium tertiary phosphate, and diphosphate. Inorganic alkaline agents such as ammonium acid, sodium bicarbonate, sodium carbonate, potassium carbonate, ammonium carbonate, etc., mono-, di- or triethanolamine, and tetraalkyl hydroxide. It can contain an activator, an organic solvent, and an organic carboxylic acid.

〔Effect of the invention〕

According to the present invention, it is possible to provide a photosensitive lithographic printing plate material that does not require dampening water and is excellent in both visible imageability upon exposure and visible imageability during development.

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

A primer solution having the following composition was applied onto an anodized aluminum plate treated with sodium silicate so that the film thickness after drying was 5 cm.

(Brimer composition) PF6 salt of condensate of p-diazodiphenylamine and formaldehyde 10g 2-hydroxyethyl methacrylate/methyl methacrylate (
50150 molar ratio) copolymer
100g zinc oxide
20g Get Yellow 402
1.0g Methyl lactate 80
After coating and drying, the primer was cured by irradiating ultraviolet light of 300 s+J/cm' with a high-pressure mercury lamp to form a primer history.

Next, a photosensitive solution having the following composition was applied to the primer layer so that the film thickness after drying was 0.4 gm, and dried to form a photosensitive layer.

(Photosensitive liquid composition) PF6j, a condensate of p-diazodiphenylamine and formaldehyde! ? lQg 2-hydroxyethyl methacrylate/4-hydroxyphenyl methacrylate/methyl methacrylate (30150/20
molar ratio) copolymer tag
Pigments of the present invention (listed in Table 1) 0.5 g Methyl lactate 480 g
The film thickness after drying of the silicone rubber liquid with the following composition is 2uL.
After coating in a uniform manner, a polypropylene film was laminated to prepare a plate material sample.

(Silicone rubber liquid composition) Polydimethylsiloxane with hydroxyl groups at both ends (molecular weight: 37
,000) 9g triacetoxysilane 0.9g dibutyltin laurate 0.07g Isopar E (manufactured by Ekun) 90g The obtained plate sample was drawn with a 4kV metal halide lamp! After exposure, the plate was immersed in 5DR-1 (Konica Hoso) diluted 6 times with water for 40 seconds, and developed by rubbing it with radiation to prepare a printing plate.

Next, the density of the image area (east exposed area) and non-image area (exposed area) after exposure was measured using a densitometer (Konica PI A-65) using an orange filter.The results are shown in Table 1. Ta. After development, dye the image area (primer layer) with the following staining solution.
Table 1 shows the results of staining and measuring the density of one image area and non-image area.

Table 1 (Staining solution m1!?) Victoria Pure Blue BOH 1 part by weight Turfitz (manufactured by Kuraray Sonoregi Chemical) 20 parts by weight Leodor TWO-120 (Made by Hanasen) 0.5 parts by weight benzyl alcohol 5 parts by weight water 100 parts by weight

Claims (2)

[Claims] (1) A photosensitive lithographic printing plate material that does not require dampening water and is treated with an aqueous alkaline developer and has a primer layer, a photosensitive layer, and a silicone rubber layer in this order on a support, in which the photosensitive layer is A photosensitive lithographic printing plate material that does not require dampening water and is characterized by containing a dye that increases absorption in the wavelength range of up to 700 nm and restores color during the development process. (2) The dampening water-free photosensitive lithographic printing plate material according to claim 1, wherein the primer layer contains a dye whose absorption in the wavelength range of 400 to 700 nm increases with acid and which restores color during the development process.