JPH03284752A - Dampening waterless planographic printing plate material - Google Patents

Abstract

PURPOSE:To improve the halftone reproducibility, plate wear and developing latitude of the printing plate by incorporating an inorg. filler into a primer layer. CONSTITUTION:This printing plate material is formed by successively forming the primer layer, a photosensitive layer and a (photosensitive) silicone rubber layer on the base. The inorg. filler is incorporated into the primer layer. The content of this filler is preferably specified to 10 to 80wt.% and the filler is preferably selected from zinc oxide, aluminum oxide, silica, and silica gel. A copolymer of 2-hydroxyethyl methacrylate and methyl methacrylate may be crosslinked and used in the primer layer and desired assistants may be added thereto.

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 more specifically to a dampening solution that can improve printing durability and development latitude as well as film strength of the primer layer. Concerning unnecessary lithographic printing plate materials.

[Conventional technology]

A dampening water-free lithographic printing plate material C having a photosensitive layer and a silicone rubber layer on a support (hereinafter abbreviated as ``plate material'' as necessary) to a dampening water-free lithographic printing plate (hereinafter referred to as ``plate material'' as necessary)
To obtain a printing plate (abbreviated as "printing plate"), a manuscript, such as a positive film, is vacuum-adhered to the surface of the plate material, exposed to light using, for example, a metal halide lamp, and then developed with a developer. Only the photosensitive layer or the silicone rubber layer is removed, and a printing plate in which recessed image areas are formed can be obtained.

In order to improve the plate-making performance of such printing plates, a primer layer has conventionally been provided between the support and the photosensitive layer.

[Problem to be solved by the invention]

However, when looking at the plate-making performance of conventional printing plates having primer layers, halftone reproducibility and printing durability are not necessarily sufficient, and improvements have been sought.

Further, for example, when the concentration of the developer is doubled, the temperature of the developer is increased, or the development time is tripled, the halftone dot reproducibility decreases significantly and the development latitude performance is low.

Furthermore, when the support is made of metal such as aluminum or iron plate, it is more difficult to improve the adhesive strength between the support and the adhesive layer.

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 and can improve halftone reproducibility, printing durability, development latitude, and film strength of the primer layer.

[Means to solve the problem]

In order to achieve the above-mentioned object, the present inventor has conducted intensive studies and has 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 or a photosensitive silicone rubber layer on a support. It is characterized in that the layer contains an inorganic filler.

Moreover, as a preferred embodiment of the present invention, sa! The content of the filler is 10 to 80% by weight, and the inorganic filler is at least one selected from zinc oxide, aluminum oxide, silica, or silica gel.

[Structure of the invention]

The present invention will be explained in detail below.

The lithographic printing plate material that does not require dampening water of the present invention has a structure in which, on a support,
It has a primer layer, a photosensitive layer, and a silicone rubber layer, and if necessary, it may have an adhesive layer between the photosensitive layer and the silicone rubber layer, and it also has a light-transmitting film layer on the silicone rubber layer. Alternatively, the photosensitive layer and the silicone rubber layer may be a single photosensitive silicone rubber layer.

(Support) 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, as well as chromium and zinc.

Metal plates plated or vapor-deposited with copper, nickel, aluminum, iron, etc. are preferable, and paper, plastic films, glass plates, resin-coated paper, paper covered with metal foil such as aluminum, plastic films treated to make them hydrophilic, etc. It may be.

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 μL, more preferably 100 to 300 JL.

(The Brimer M primer layer contains an inorganic filler. By containing the inorganic filler, it is possible to improve halftone dot reproducibility, stiffness resistance, development latitude, and film strength of the primer layer. Such effects Although this is only speculation, it is thought that the surface hydroxyl groups of the inorganic filler greatly contribute to improving the film strength, which leads to improvements in halftone dot reproducibility, printing durability, and development latitude. 1. It is difficult to achieve the object of the present invention with an organic filler that does not have a hydroxyl group on its surface.

Although JP-A-1-237551 discloses a technique for adding pigments to the primer layer, the purpose of the present invention cannot be achieved only by adding such pigments at random. This is because it also includes pigments.

That is, in the present invention, an inorganic filler is used, and at least one selected from zinc oxide, aluminum oxide, silica, or silica gel is preferably used as the inorganic filler. Among these, zinc oxide is more preferred.

Further, the content of the inorganic filler is 10 to 80% by weight based on the total amount of the primer layer composition excluding the solvent,
Preferably it is in the range of 20 to 80% by weight. If it is less than 10% by weight, no improvement in performance can be expected by adding filler, and if it exceeds 80% by weight (when applying the primer layer)
It becomes difficult to smooth the surface of the layer. As a result, developability and printing durability are significantly reduced.

Further, the particle size of the inorganic filler is preferably one diameter or less, more preferably 0.3 μm or less. This is because if the thickness exceeds 1 bar, not only will it be difficult to smooth the surface of the layer (when applying the primer layer), but the specific surface area of the filler will become smaller, reducing the additive effect. It is.

It should be noted that the inorganic fillers of the present invention may be used in combination of two or more types, and it is not excluded that organic fillers may be added together with the inorganic fillers of the present invention to the extent that the effects of the present invention are not impaired. .

The primer layer of the present invention includes, for example, polyester resin,
Vinyl chloride-vinyl acetate copolymer, acrylic resin, a!
vinyl resin, polyamide resin, polyvinyl butyral resin, epoxy resin, acrylate copolymer, vinyl acetate copolymer, phenoxy resin, polyurethane resin,
Polycarbonate resin, polyacrylonitrile butadiene, polyvinyl acetate, etc. are used.

Among these, resins obtained by photocrosslinking or thermally crosslinking copolymer resins of (meth)acrylic esters having alcoholic OH groups, such as 2-hydroxyethyl methacrylate, are preferred.

Further, a silane coupling agent, a silicone primer, etc. can be used in the primer layer.

(Photosensitive layer) The structure of the photosensitive layer 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. Other examples of 0-naphthoquinone diazide compounds include 1, for example, U.S. Pat.
．． Ester of pyrogallol-acetone resin and 0-naphthoquinonediazide sulfonic acid chloride described in No. 835.709, JP-A No. 55-78348, No. 5B
Ester of polyhydroxyphenyl resin and 0 to naphthoquinonediazide sulfonic acid chloride described in No. 1044 and No. 5B-1045, JP-A-1983-11
3305, a homopolymer of p-hydroxystyrene or a copolymer of this and other copolymerizable monomers with O-naphthoquinonediazide sulfonic acid chloride, ester-reacted, Japanese Patent Publication No. 411
-174fl1, a reaction product of a polymer product of a styrene monomer and a phenol derivative and 0-quinonediazide sulfonic acid, and an ester of polyhydroxybenzophenone and 0-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 novolac resins soluble in aqueous alkaline solutions. Representative examples of such Nopola 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% in the photosensitive composition.
~80% by weight, preferably 50-70% by weight.

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 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, and U.S. Pat.
Examples include diazo resin organic salts, which are reaction products of the above condensate and sulfonic acids, as described in No. 308. The diazo resin is preferably used together with a binder. Various polymeric compounds can be used as such a binder, but monomers having an aromatic hydroxyl group such as those described in JP-A-54-18613, such as N-(4-hydroxyphenyl ) acrylamide, tho(4-hydroxyphenyl)methacrylamide,
a-, ■-1 or P-hydroxystyrene, o-, m
Copolymer of -1 or p-hydroxyphenyl methacrylate and other monomers, U.S. Pat. No. 4,123,276
Polymers containing hydroxyethyl acrylate units or hydroxyethyl methacrylate units as a main repeating unit, natural resins such as shellac and rosin, polyvinyl alcohol, and U.S. Pat.
, 751,257,
Included are linear polyurethane resins, polyvinyl alcohol phthalate resins, epoxy resins condensed from bisphenol A and epichlorohydrin, celluloses such as cellulose acetate and cellulose acetate phthalate, which are described in U.S. Pat. No. 3, flBO, 0117. .

In addition, there are also those whose main component is a photosensitive polymer such as polycarbonate, which has a photosensitive group in the main chain or side chain of the polymer. (2- Examples include photosensitive polyesters derived from malonic acid compounds (properiden) and difunctional glycols.

Further examples include aromatic azide compounds in which the azide group is bonded directly or via a carbonyl or sulfonyl group to an aromatic ring. For example, polyazidostyrene as described in U.S. Pat. No. 3,096,311; Polyvinyl-p-azidobenzoate, polyvinyl-P-azidobenzal, the reaction product of azidoarylsulfanyl chloride and unsaturated hydrocarbon polymer described in Japanese Patent Publication No. 45-9613, and Japanese Patent Publication No. 43-21087, No. 44-229, No. 4422954 and No. 45-24
Examples include polymers having sulfonyl azide and carbonyl azide, as described in No. 915.

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

The thickness of the photosensitive layer is preferably 0.05 to 10 ILm, more preferably (1,1 to 2 #Lm).

In the present invention, the photosensitive material further includes an inorganic filler,
Dyes, dyes, pigments, surfactants for improving coating properties and other conventional additives and auxiliaries can be contained.

(Silicone Rubber Layer) The silicone rubber used in the silicone rubber layer is a linear organic polysiloxane having primary 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

(-9i -0+1 where n is an integer of 2 or more, R is a C1-C10 furkyl group, 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.

Silicone rubbers useful in the present invention are those obtained by condensation reactions between such silicone base polymers and primary silicone crosslinking agents.

(1) R-Si+OR') (2) R-5i-fOAc) (3) R-Si÷0N-CR'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 A
C 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 include the reaction of base polymers such as those listed above with silicone oils having repeating units such as the first order.

Alternatively, it can be obtained by an addition reaction with a silicone base polymer in which about 3% of R is a vinyl group, or 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, tin and zinc.

Organic carboxylates of metals such as cobalt, lead, calcium, manganese, etc., such as dibutyltin laurate, tin (
n) Catalysts such as octoate, cobalt naphthenate, etc. or chloroplatinic acid are 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 fillers is commercially available as silicone rubber stock or silicone rubber dispersion, and as in the present invention, by coating,
If it is preferred to obtain a silicone rubber film, RT
V! Alternatively, dispersion of LTV silicone rubber is preferably used. An example of this is )-Lyshi!
, l=+-N Syl ON 23.5RX-257
There are silicone rubber dispersions for paper coating such as , 58237.

In the present invention, it is preferable to use condensation and crosslinking type silicone rubber.

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) H2NCH2CH2NHCCHC:H2CH2
S1(QC)I3)3(b) CH2CH2H20(C
HzhSi(OCH3)+\1 (c) HS(CHzhSi(OClhh(d) CH
2H2CH21COCH3) 3(e) GHz<-C:
00(CHzhSi(OCH3hH3 (f) CH2=CH5i(OCOCH3)3(g)
H2NCH2CH2NH (CHzhSi(QC:HS)
The thickness of the 2(CH3)(h) chlorosilane silicone rubber layer is preferably 0.1 to +07 mm, more preferably 0.5 to 2 mm.

Note that in the case of forming a photosensitive silicone rubber layer, the photosensitive layer may not be provided, and such a photosensitive silicone rubber may include γ-methacryloxypropyltrimethoxysilane or 100-nocinnamoyldiethoxysilane at the terminal OH group of dimethylpolysiloxane. Examples include compounds obtained by dealcoholization condensation of silane, compounds obtained by adding a bisazide compound to polydiorganosiloxane, or compounds obtained by reacting acryloyl chloride or p-azidobenzoate.

A light-transmissive film layer is provided on the silicone rubber layer as necessary, and the resin used for the film layer includes polyolefins such as polypropylene, polyethylene, polymethylpentene, and ethylene-butene copolymer. , polystyrene, fluororesin, polyethylene terephthalate, nylon, polyvinyl alcohol, polycarbonate, polymethyl methacrylate, polyimide, polyacrylonitrile, and the like.

Next, a method for manufacturing the plate material of the present invention will be explained.

A composition solution to form a brimer layer is applied onto a 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 Whaler, and is dried to form a brimer layer. Next, apply a composition solution to form a photosensitive layer in the same manner and dry to form a photosensitive layer. Next, if necessary, apply an adhesive layer on the photosensitive layer in the same manner, and after drying, apply a silicone rubber solution. was applied onto the adhesive layer using a method similar to rW1.

It is usually heat treated at a temperature of 100-120° C. for several minutes to fully cure and form a silicone rubber layer.

Next, a light-transmitting film is laminated onto the silicone rubber layer.

Next, a method for producing a printing plate using the plate material of the present invention will be explained.

A positive film, which is the manuscript, is vacuum-adhered to the surface of the plate 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, the light-transmissive film is peeled off and developed with a developer to remove only the silicone rubber layer and photosensitive layer or silicone rubber layer in the unexposed areas.

A printing plate in which the recessed image portion is formed can be obtained as described above.

〔Effect of the invention〕

According to the first aspect of the invention, it is possible to provide a lithographic printing plate material that does not require dampening water and can improve halftone dot reproducibility, printing durability, development latitude, and film strength of the primer layer.

Further, according to the invention according to claim 2 or 3, halftone reproducibility,
It is possible to provide a lithographic printing plate material that does not require dampening water and has further improved printing durability, development latitude, and film strength of the primer layer.

〔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. In the following description, "parts" refers to "parts by weight". means.

Example-1 (Synthesis of diazo resin-1) p-diazodiphenylamine sulfate 14.5g (50
mmol) was dissolved in 40, sg concentrated sulfuric acid under ice-cooling.

Add 1.35 to this reaction solution. (45 mmol) of paraformaldehyde was added slowly such that the reaction temperature did not exceed 10°C.

This reaction mixture was added dropwise to 5001 ethanol under water cooling, and the resulting precipitate was filtered. After washing with ethanol, this precipitate was dissolved in 1001 pure water, and to this solution was added a cold concentrated aqueous solution in which 8.8 g of molded summer lead was dissolved. The resulting precipitate was filtered, washed with ethanol, and dissolved in 1501 pure water. To this liquid was added a cold concentrated aqueous solution in which 8 g of ammonium hexafluorophosphate was dissolved. The resulting precipitate was filtered, washed with water, and then dried to obtain diazo resin-1.

(Manufacture of aluminum plate a) An aluminum plate with a thickness of 0.24 mm is immersed in a 3% aqueous sodium hydroxide solution to degrease it, washed with water, and then immersed in a 32% aqueous sulfuric acid solution at a temperature of 30°C and a condition of 5 A/dm''. 1
It was anodized for 0 seconds, washed with water, immersed in a 2% sodium metasilicate aqueous solution at a temperature of 85°C for 37 seconds, and further immersed in water (pH 8.5) at a temperature of 80°C for 25 seconds.

Wash with water, dry, and remove aluminum plate A.

A primer layer composition having the composition shown below was dispersed and coated on an aluminum plate a, and after drying at 85°C for 3 minutes, the entire surface was exposed to light at 1000 J/ctn' using a 3KW ultra-high pressure mercury lamp. It was further dried at 100°C for 4 minutes to a thickness of 0.8.
A primer layer (2) was formed.

Primer layer composition〉 Silicone rubber composition〉 Next, a photosensitive composition having the following composition was coated on the primer layer and dried at 100°C for 2 minutes to form a photosensitive layer with a thickness of 0.3 mm. was formed.

Photosensitive Composition> Next, the following silicone rubber composition was coated on the photosensitive layer at a dry weight of 1.8 g/g, and heated at 90°C for 10
Dry for a minute.

Next, a one-sided matted polypropylene film having a thickness of 0.5 mm was laminated on the silicone rubber layer to obtain a plate material.

After vacuum-adhering the positive film to the top surface of the above plate material,
After exposure using a metal halide lamp as a light source and immersing it in the following developer solution-1 (27°C) for 1 minute,
By rubbing the surface of the plate material with a pad impregnated with a developer, the unexposed silicone rubber layer and photosensitive layer are removed, resulting in a printing plate with well-reproduced halftone dots (as shown in Table 1).
A printing plate) was obtained.

Furthermore, the image area of the printing plate could be vividly dyed by applying a dyeing liquid having the composition shown below to a cloth, lightly rubbing the plate, and then washing with water.

Developer solution-1> In addition, in the above experiment, in order to evaluate the development latitude, (1) when a developer with twice the concentration of the developer was used, (2) when the developer temperature was changed to 35°C, ■An experiment was conducted in the case where the developing time was tripled. Table 1 shows the results.
Shown below.

Table 1 also shows the results of evaluating the printing durability of the printing plates.

Dyeing Solution Example 2 A plate material was obtained in the same manner as in Example 1, except that the primer composition of Example 1 was changed as follows.

Primer Composition> Next, a printing plate was obtained in the same manner as in Example 1, and the development latitude and printing durability of the printing plate were evaluated, and the results shown in Table 1 were obtained.

Example-3 A plate material was obtained in the same manner as in Example-1 except that the primer composition of Example-1 was changed as follows.

Primer Composition> Next, a printing plate was obtained in the same manner as in Example 1, and the development latitude and printing durability of the printing plate were evaluated, and the results shown in Table 1 were obtained.

Example 4 (Reference Example) A plate material was obtained in the same manner as in Example 1, except that the primer composition of Example 1 was changed as follows.

Primer Composition> Next, a printing plate was obtained in the same manner as in Example 1, and the development latitude and printing durability of the printing plate were evaluated, and the results shown in Table 1 were obtained.

Example-5 A plate material was obtained in the same manner as in Example-1 except that the primer composition of Example-1 was changed as follows.

Primer Composition> Comparative Example-1 A plate material was obtained in the same manner as in Example-1 except that the primer layer composition of Example-1 was changed as follows.

Primer Composition> Next, a printing plate was obtained in the same manner as in Example 1, and the development latitude and stiffness resistance of the printing plate were evaluated.

The results shown in Table 1 were obtained.

Next, a printing plate was obtained in the same manner as in Example 1, and the development latitude and stiffness resistance of the printing plate were evaluated, and the results shown in Table 1 were obtained.

Comparative Example 2 A dampening water-free photosensitive lithographic printing plate was obtained in the same manner as in Example 1, except that the primer composition of Example 1 was changed as follows.

Printer Composition> Next, a printing plate was obtained in the same manner as in Example 1, and the development latitude and printing durability of the printing plate were evaluated, and the results shown in Table 1 were obtained.

Comparative Example-3 A plate material was prepared in the same manner as in Example-1, except that the amount of fine zinc white, which is the primer composition of Example-1, was changed to 9 parts J (8.3% by weight). Obtained.

Next, a printing plate was obtained in the same manner as in Example 1, and the development latitude and printing durability of the printing plate were evaluated, and the results shown in Table 1 were obtained.

Comparative Example-4 A plate material was obtained in the same manner as in Example-1, except that the amount of fine zinc white, which is the brimer composition of Example-1, was changed to "500 parts" (83% by weight). .

Next, a printing plate was obtained in the same manner as in Example 1, and the development latitude and printing durability of the printing plate were evaluated, and the results shown in Table 1 were obtained.

Comparative Example-5 A plate material was obtained in the same manner as in Example-1 except that the brimer composition of Example-1 was changed as follows.

Primer Composition> Next, a printing plate was obtained in the same manner as in Example 1, and the development latitude and printing durability of the printing plate were evaluated, and the results shown in Table 1 were obtained.

Claims (1)

[Scope of Claims] 1. A dampening water-free lithographic printing plate material having a primer layer, a photosensitive layer, and a silicone rubber layer or a photosensitive silicone rubber layer on a support, wherein the primer layer contains an inorganic filler. A lithographic printing plate material that does not require dampening water. 2. The lithographic printing plate material that does not require dampening water according to claim 1, wherein the content of the inorganic filler is 10 to 80% by weight. 3. The dampening water-free lithographic printing plate material according to claim 1 or 2, wherein the inorganic filler is at least one selected from zinc oxide, aluminum oxide, silica, and silica gel.