JPH03271742A - Production of dampening waterless planographic printing plate - Google Patents

Abstract

PURPOSE:To improve development stability by mixing a hardener with a primer layer compsn. in-line before the application of this compsn. CONSTITUTION:The primer layer 4 is formed by drying the primer layer compsn. contg. gelatin on a base 3 and drying the coating. The hardener is mixed with this compsn. in-line before the application of the primer layer compsn. Namely, the primer layer compsn. contg. the gelatin is supplied to a static mixer 2 from a supply section A and the hardener is supplied to the static mixer 2 from a supply section B. Both are mixed in the static mixer 2 just before the application and the mixture is supplied after mixing to a coating machine 1. The mixture is applied on the base 3 and the primer layer 4 is formed. The development stability is improved in this way.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a method for producing a lithographic printing plate material that does not require dampening water, and more particularly relates to a method for producing a lithographic printing plate material that has stable developability and does not require dampening water. .

(Prior art) A dampening water-free planographic printing plate (hereinafter abbreviated as "plate material J" as necessary) is prepared from a dampening water-free planographic printing plate material (hereinafter abbreviated as "plate material J" as necessary) having a photosensitive layer and a silicone rubber layer on a support. Below, if necessary,
To obtain a printing plate (abbreviated as J), 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. By removing only the photosensitive layer or the silicone rubber layer, it is possible to obtain a printing plate with recessed image areas formed thereon.

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.

JP-A No. 63-305: l [i0] uses gelatin in the primer layer to improve resistance to organic solvents against the coating solvent of the photosensitive layer and skin solvents of the developer, or to improve halftone reproducibility and dyeing properties. Techniques to improve this have been disclosed.

Furthermore, JP-A-1-172834 discloses a technique in which a primer layer containing gelatin as a main component is applied and then a hardening agent is infiltrated into the primer layer.

(Problem to be solved by the invention) However, when gelatin is used in the primer layer as in JP-A-Sho [i:l-305360], in order to improve work efficiency, a coating solution with a molecular weight of about 24 hours is used. Gelatin and a hardening agent were mixed and prepared in advance.When coating using this pre-mixed hatching coating solution, the developability of the resulting plate material can be improved within 4 to 8 hours after the start of coating. It was found that it took a long time to develop in order to obtain a printing plate with a good image when using a coating solution that had been used for 10 to 12 hours. It was found that the optimal development time was different between the plate material obtained by coating after several hours and the plate material obtained by coating after several hours.

In addition, as in JP-A-1-172834, the method of applying a gelatin-based primer layer and then penetrating the primer layer with a hardening agent requires an additional plate manufacturing process, which increases equipment investment costs. This is disadvantageous in terms of production efficiency, and it also has the disadvantage of increasing instability during manufacturing.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a method for producing a lithographic printing plate material that does not require dampening water and can improve the development stability of the resulting printing plate material.

Another object of the present invention is to develop a lithographic printing plate material that does not require dampening water and can reduce equipment investment costs and manufacturing costs and increase production efficiency by shortening the plate manufacturing process and stably manufacturing it. The purpose is to provide a manufacturing method.

(Means for Solving the Problems) The inventors of the present invention have conducted intensive studies to achieve the above-mentioned object, and have thus arrived at the present invention.

That is, in the method for producing a lithographic printing plate material that does not require dampening water according to the present invention, a primer layer composition containing gelatin is coated on a support and dried to form a primer layer, and then a photosensitive layer and a silicone rubber layer or The method for producing a lithographic printing plate material that does not require dampening water and in which a photosensitive silicone rubber layer is sequentially formed is characterized in that a hardening agent is mixed in-line with the composition before applying the primer layer composition.

[Structure of the invention]

The method for producing the lithographic printing plate material that does not require dampening water according to the present invention is as follows.

A primer layer composition solution is applied onto a support using a coating machine and then dried to form a primer layer. Next, apply a photosensitive layer composition solution 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 on the adhesive layer in the same manner. The silicone rubber layer is formed by applying the silicone rubber layer using the method described above and heat-treating it for several minutes, usually at a temperature of In to 120°C, to fully cure the silicone rubber layer. Next, a light-transmitting film is laminated onto the silicone rubber layer.

The dampening water-free lithographic printing plate material obtained by the production method of the present invention basically has a fryer layer, a photosensitive layer, and a silicone rubber layer on a support. Those with an adhesive layer between the silicone rubber layer and the silicone rubber layer, those with a light-transmitting film layer on the silicone rubber layer, and those with a photosensitive layer and silicone rubber layer integrated into a photosensitive silicone rubber layer. It may be a combination of the following.

(Support) The support is preferably one that has the flexibility to be set in a normal lithographic printing machine and can handle the load applied during printing, such as aluminum zinc, metal plates such as JO1 steel, chromium, Metal plates plated or vapor-deposited with zinc, copper, nickel, aluminum, iron, etc. are preferred, and paper, plastic films and glass plates, resin coated paper, paper covered with metal foil such as aluminum, and wood-treated It may also be a plastic film or the like.

Among these, preferred is an aluminum plate. When an aluminum plate is used, it may be subjected to surface roughening treatment such as graining treatment or anodizing treatment.

The thickness of the support is preferably 50 to 400 p or m,
More preferably 100 to 300 p, m.

(Primer layer) The primer layer is formed by coating and drying a primer layer composition containing gelatin on a support, or in the present invention, a hardening agent is applied in-line before coating the primer layer composition. It is characterized by being mixed into the composition.

In the present invention, "mixing the hardener in-line before coating" means adding the hardener to the line that supplies gelatin to the coating machine, preferably adding and mixing it immediately before coating. That's true.

Hereinafter, an example of the method for forming a primer layer of the present invention will be explained based on the drawings.

FIG. 1 is an explanatory diagram showing the state in which a primer layer is formed by a coating machine, and in the figure, 1 is a coating machine, and 2 is a mixing means installed near the coating machine 1, such as a static It's a mixer.

The primer layer composition containing gelatin is supplied from supply section A to static mixer 2, and the hardener is supplied from supply section B to static mixer 2, where the two are mixed immediately before coating. . After mixing, the mixture is supplied to a coating machine 1 and coated on a support 3 to form a primer layer 4.

As a coating machine, a conventional coater such as a reverse roll coater, an air knife coater, a Meyer coater, or a rotary coating device such as a Whaler is used.

In the present invention, a silane coupling agent, a silicone primer, an organic titanate, etc. may be used in the primer layer.

The gelatin contained in the primer layer is mainly
So-called photographic gelatin obtained from cow bones and hides by acid treatment or alkali treatment, gelatin derivatives, tallaf polymers of gelatin and other polymers, proteins, sugar derivatives, cellulose derivatives, single or copolymers The object of the present invention can also be achieved by using wood-philic colloids such as synthetic hydrophilic polymeric substances such as the following.

(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, quinone diaside type positive photosensitive substances such as the conventionally known 0-naphthoquinone cyacyto compound can be mentioned.

Suitable 0-naphthoquinone diacid compounds include naphthoquinone-(1,2)-diazide-(2)-sulfonic acid chloride and phenol or cresol-formaldehyde as described in U.S. Pat. No. 3,046,120. There are esters with resins. Other 0-naphthoquinone cyacyto compounds include, for example, U.S. Pat.
, 635,709. -Ester of naphthoquinone siasitosulfonic acid chloride, JP-A-55-76346, JP-A-55-55
Ester of polyhydroxyphenyl resin and O-naphthoquinone cyacytosulfonic acid chloride described in No. 1044 and No. 56-1045, JP-A No. 50-11
A homobomber of p-hydroxystyrene as described in No. 3305 or a copolymer of this and other copolymerizable monomers is ester-reacted with O-naphthoquinone cyasitosulfonic acid chloride, Japanese Patent Publication No. 491
7481, a reaction product of a polymer product of a styrene monomer and a phenol derivative and O-quinonediacidosulfonic acid, and a reaction product of polyhydroxybenzophenone and O-
Examples include esters of naphthoquinone cyanosulfonic acid chloride.

A binder may be added to a photosensitive composition containing such a quinonediaside type photosensitive substance, if necessary.

For example, suitable examples include novolac resins soluble in aqueous alkaline solutions. Representative examples of such novolak 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
Preferably 0% by weight, more preferably 20-40% by weight
It is. Further, the amount of the above-mentioned binder added is 4% in the photosensitive composition.
5 to 80% by weight is preferable, more preferably 50 to 70% by weight.
Weight%.

Further, as the photosensitive substance, a diazo resin typified by a condensate of an aromatic diazonium salt and formaldehyde can also be 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, 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. 309. Furthermore, the cyan resin is preferably used together with a binder. Various polymeric compounds can be used as such a binder, but preferred are those described in JP-A-54-98613.
Monomers with aromatic hydroxyl groups 1 such as N-(4-hydroxyphenyl)acrylamide, N-(4-hydroxyphenyl)methacrylamide, O-, S-1 or p-hydroxy styrene, o
-21, or copolymer of p-hydroxyphenyl methacrylate, etc. and other monomers, U.S. Pat. No. 4.123,2
Polymers containing hydroxyethyl acrylate units or hydroxyethyl methacrylate units as a main repeating unit as described in US Pat. No. 76, natural resins such as shellac and rosin, polyvinyl alcohol, Boriacto resin, U.S. Patent No. 3.660. (These include linear polyurethane resins described in No. 197, phthalated polyvinyl alcohol resins, epoxy resins condensed from bisphenol A and epichlorohydrin, celluloses such as cellulose acetate and cellulose acetate phthalate.

Also included are those whose main component is a photosensitive polymer such as a photosensitive group or polycarbonate as a photosensitive group in the main chain or side chain of the polymer. For example, a photosensitive polyester obtained by condensing phenylene diethyl acrylate with hydrogenated bisphenol A and triethylene glycol as described in JP-A No. 55-40415; Photosensitive polyesters derived from (2-probeliden) malonic acid compounds such as cinnamylidene malonic acid and difunctional glycols, as described, and the like.

Further examples include aromatic acid compounds in which the azide group is bonded directly or via a carbonyl or sulfonyl group to an aromatic ring. For example, boriasitostyrene as described in U.S. Pat. No. 3,096,311 Polyvinyl-p-acidobenzoate, polyvinyl-p-azidobenzal, the reaction product of azidoarylsulfanyl chloride and unsaturated hydrocarbon polymer described in Japanese Patent Publication No. 45-96I3, and Japanese Patent Publication No. 43-21067, No. 44-229, No. 44-22954 and No. 45-2
Examples include polymers containing sulfonyl azide or carbonyl azide, as described in No. 4915.

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 mm, more preferably 0.1 to 2 #LII.

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 may be included.

(Silicone Rubber Layer) The silicone rubber used for the silicone rubber layer is a linear polyester resin having a molecular weight of several thousand to several hundred thousand and having an OH group in the main chain or at the end of the main chain, as shown below. It is preferable to use siloxane as the main component.

(-3i -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,
It is preferable that it is a silanol group (Kano group), and that 50% or more of the total amount 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, and is preferably located at the end.

Silicone rubbers useful in the present invention are those obtained by condensation reactions of such silicone paste polymers with primary silicone crosslinking agents.

(1) R-si(-oR') (2) R5i(-OAc) (3) RS! (-ON=CR'a)*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.

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

Other silicone rubbers for skin use are produced by reacting the base bombers listed above with silicone oils having the following repeating units, or by reacting silicone base polymers with about 3% H or vinyl groups. addition reaction,
Alternatively, it can also be obtained by a reaction between the silicone oils.

In order to obtain silicone rubber by such a crosslinking reaction, In addition to the above ingredients, organic carboxylates of metals such as tin, zinc, cobalt, lead, calcium, and manganese, such as dibutyltin laurate, tin (II) octoate, cobalt naphthenate, etc., or chloroplatinic acid, etc. 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,
It is also possible to mix fillers. 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 preferable to obtain a silicone rubber membrane, RT
Disversions of V or LTV silicone rubber are preferably used. An example of this is Syl Off 23.5RX-257°5H manufactured by Toray Silicone.
There are silicone rubber dispersions for paper coating such as 237.

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 a photosensitizer may 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) 82NCR2C)1. NFICCH2CH1C
H2Si(OCI(1):+(b) CHzCHCHz
O(CHz)3sI(OCHz)z\1 (c) H3(CHa)*5i(OCH:+)+(d)
CHt-CH81 (OCOC island): l(f) CH2-C
H3I (OCHtCHz) x (g) HJCH2CI
The thickness of the IJH(CL)isi(OCHi)2(CL)(h) 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, the photosensitive layer may not be provided, and such a photosensitive silicone rubber may include γ-methacryloxypropyltrimethoxysilane or monocinnamoyljetoxy 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-acidobenzoate.

A light-transmissive film layer is provided on the silicone rubber layer as necessary, and the resin used for the film 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 a printing plate using a plate material obtained by the mold making method of the present invention will be explained.

The original positive film is placed in vacuum contact with the plate surface and exposed to light.The light source used for this exposure is a mercury lamp, carbon arc lamp, xenon lamp, metal halide lamp, fluorescent lamp, etc., which generate abundant ultraviolet light.'' When the light-transmitting film is peeled off and developed with a developer, only the silicone rubber layer and the photosensitive layer or the silicone rubber layer in the unexposed areas are removed.As described above, the recessed image area is formed. You can get a printed version.

(Effect of the invention) According to the invention, development stability can be improved,
Moreover, by shortening the plate manufacturing process and stably manufacturing, equipment investment costs and manufacturing costs can be reduced and production efficiency can be increased.

(Examples) Hereinafter, the present invention will be explained in further detail by giving examples of the present invention.The present invention is not limited by these examples. Unless otherwise specified, "parts by weight" are meant.

Example 1 The following brimer layer composition and hardening solution were prepared for 12 hours on a smooth aluminum plate that had been degreased in a conventional manner.

As shown in Fig. 1, the same amount of the hardening solution was added and mixed with a static mixer in the composition supply line just before coating, and the mixture was coated at 90°C. The mixture was heated for 3 minutes and dried. This was left to stand at 20°C for 1 day to form a primer layer.

Primer Layer Composition>"The primer layer coated and hardened with 2000 parts of pure water (hardener) did not dissolve even when immersed in the following aqueous developer.

<Developer> Next, the following silicone rubber composition was spread on the photosensitive layer at a dry weight of 1.7 g/m'' and dried.
A silicone rubber layer was obtained.

<Silicone rubber composition> On the aluminum plate coated with the above primer layer, 1.0% of the following photosensitive composition was applied by dry weight. It was coated to a concentration of Og/m'' and dried.

<Photosensitive composition> A single-sided matted polypropylene film having a thickness of 12 μm was laminated on the surface of the silicone rubber layer obtained as described above to obtain a photosensitive lithographic printing plate material 1 that does not require dampening water.

As shown in FIG. 1, the above composition and hardening solution, each of which has been aged for 12 hours, are coated by adding and mixing the same amount of the hardening solution with a static mixer in the group I & material supply line immediately before coating.
A dampening water-free photosensitive lithographic printing plate material-2 was obtained in the same manner as above, except that a primer layer was formed by heating and drying at 0°C for 3 minutes.

A positive film is layered on each of these plate materials 1 and 2, vacuum-adhered, and imagewise exposed using a normal exposure device.Then, the laminated film is peeled off, and the film is immersed in the aqueous developer described above for 1 minute, and developed. I patted it and rubbed it for 1-2 minutes.

As a result, for both plate materials 1 and 2, the photosensitive layer in the unexposed area and the silicone layer thereon were removed, and the entire surface of the printing plate was covered.
A printing plate that faithfully reproduces the positive film image was obtained.

In addition, even when Plate Materials 1 and 2 are developed very strongly with the same developer, the image on the positive film can be faithfully reproduced without any image distortion, and the development latitude is sufficiently wide for water-based developers. I was able to confirm that I have it.

When I rubbed the obtained printing plate with the following dyeing solution,
Only the exposed portion of the primer layer, which is the image area, was stained a clear blue color.

<Staining solution> Comparative example-1 Three aluminum plates used in Example-1 are prepared.

If the primer layer composition and hardener of Example-1 were mixed in advance at a ratio of 1:1 and applied using an actual molding line, the amount of application would be equivalent to 12 hours. The liquid was prepared.

After preparation, primer layers were formed on each of the three aluminum plates by (1) applying the coating solution that had been used for 1 hour, (2) applying the coating solution that had been used for 8 hours, and (2) applying the coating solution that had been used for 12 hours.

Thereafter, a comparative plate material-1°2.3 was obtained and developed in the same manner as in Example-1.

With the comparative plate materials-1 and 2 obtained, it was possible to obtain printing plates that faithfully reproduced images, as in Example-1.

However, the developability of Comparative Plate Material-3 changed significantly, and in order to obtain a printing plate with good image reproduction, it required twice as much development time as that of the Plate Material of Example-1.

In this manner, it was found that in coating by hatching, the developability of the obtained plate material differs significantly between the initial and final coating.

Example 2 Fountain water-free photosensitive lithographic printing plate materials 3 and 4 were obtained in the same manner as in Example 1, except that the hardening solution in Example 1 was changed as follows.

Hardener> The coated and hardened primer layer did not dissolve even when immersed in the same aqueous developer as in Example-1.

The obtained plates 3 and 4 were subjected to image exposure in the same manner as in Example-1.
When development was carried out, the unexposed areas of the photosensitive layer and silicone layer were removed, and a printing plate that faithfully reproduced the image was obtained.

Furthermore, even when this printing plate was developed very strongly with the same developer, the image did not collapse, confirming that it had a wide development latitude.

When the obtained printing plate was rubbed with the staining solution of Example-1, only the image area was clearly dyed.

Comparative example-2 Three aluminum plates used in Example-1 are prepared.

The brimer layer composition of Example 2 and the hardener were mixed in advance at a ratio of 1:1, rather than in-line, to prepare a coating solution for 12 hours.

After mixing, the coating solution that had been used for 01 hours was applied to each of the three aluminum plates.

■Apply the coating solution after 8 hours, ■Apply the coating solution after 12 hours. A primer layer was formed for each.

Thereafter, a comparative plate material-4°5.6 was obtained and developed in the same manner as in Example-2.

Using the obtained comparative plates 4 and 5, it was possible to obtain printing plates that faithfully reproduced one image in the same manner as in Example 2.

However, Comparative Plate Material-6 had a significant change in developability, and in order to obtain a printing plate with good image reproduction, it required approximately three times as much development time as the Plate Material of Example-1.

As described above, it has been found that in coating by hatching, the developability of the obtained plate material differs significantly between the initial and final coating.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing a state in which a primer layer is formed by a coating machine. 1: Coating machine 2: Mixing means 3: Support 4 Nib primer layer A, primer layer composition supply section B: Hardener supply section

Claims (1)

[Claims] Coating a primer layer composition containing gelatin on the support.
In a method for producing a lithographic printing plate material that does not require dampening water, in which a primer layer is formed by drying, and then a photosensitive layer and a silicone rubber layer or a photosensitive silicone rubber layer are sequentially formed, an in-line method is provided before applying the primer layer composition. A method for producing a lithographic printing plate material that does not require dampening water, characterized in that a hardening agent is mixed into the composition.