JPH04268558A - Photosensitive planographic printing plate and production thereof - Google Patents

Abstract

PURPOSE:To simply produce a printing plate and to prevent transfer trouble and the scratch of the photosensitive surface without inserting an overlapping sheet. CONSTITUTION:A wax compd. is incorporated into the outermost layer on one side of a substrate with a photosensitive layer on the other side or the wax compd. is applied and solidified by cooling to form a wax layer. The wax compd. is preferably higher alcohol ester of higher fatty acid or paraffin having 40-200 deg.C m.p.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to a photosensitive lithographic printing plate and a method for manufacturing the same, and more specifically, the present invention relates to a photosensitive lithographic printing plate and a method for manufacturing the same. This invention relates to a lithographic printing plate and its manufacturing method.

0002

BACKGROUND OF THE INVENTION Photosensitive lithographic printing plates are generally used that have a photosensitive layer on a metal plate support such as aluminum, iron or zinc, or a synthetic resin plate support such as a polyester film. When these printing plates are packaged, each printing plate is transported and stacked, and several dozen printing plates are stacked and packaged as one unit. Therefore, during packaging and transportation, friction between the photosensitive surface and the back surface of the support often occurs, resulting in damage to the photosensitive surface.

Various methods for preventing such damage to the photosensitive surface have been proposed for a long time. For example, there is a method of inserting a sheet of soft material between printing plate materials, and
A method of coating a molten film as a protective film on the surface of a photosensitive layer or the back surface of a support, as described in Japanese Patent No. 1-6570, and a method of coating a resin liquid using a solvent on the back surface of a support are proposed. has been done.

0004

[Problems to be Solved by the Invention] However, the method of interposing sheets between printing plate materials requires a step of inserting the sheets when processing the printing plates, and these sheets are soft and difficult to handle. It was extremely inconvenient. In addition, the surface of products coated with fused coating is easily damaged, and
When processing the plate material, it is difficult to slip, resulting in poor conveyance, and if the plate material is coated with a resin liquid, it may come into contact with the photosensitive surface.
During storage, the photosensitive layer may elute or the photosensitive compound may decompose due to the action of the solvent, resulting in deterioration of performance.

[0005]Other patent applications previously filed by the present applicant in 1982
The method of laminating a hydrophobic polymer on the back side of the support of a photosensitive planographic printing plate described in the specification of No. 191356 is still insufficient, and in particular, when coating the hydrophobic polymer, it is necessary to Because the process was carried out at high temperatures, the photosensitive component could thermally decompose during this process, which was not appropriate.

Accordingly, a first object of the present invention is to provide a photosensitive lithographic printing plate which is highly suitable for printing processing robots and which does not cause transportation troubles. A second object of the present invention is to provide a photosensitive lithographic printing plate that does not damage the surface of the photosensitive layer even when printing plates are stacked without inserting interleaving paper, and has storage stability. A third object of the present invention is to provide a method for manufacturing a photosensitive lithographic printing plate in a simple and inexpensive manner.

[0007]

[Means for Solving the Problems] The above objects of the present invention were achieved by the following configuration. 1) A photosensitive lithographic printing plate having a photosensitive layer on one side of a support, characterized in that the outermost layer of the support on the side opposite to the side having the photosensitive layer contains a wax compound. .

2) After heating the wax compound and making it liquid,
1. A method for producing a photosensitive lithographic printing plate, comprising applying the wax compound to the opposite surface of the support to the surface having the photosensitive layer, and solidifying the wax compound by cooling to form a wax layer. The present invention will be explained in more detail below.

The wax compound coated on the uppermost layer on the back side of the support of the photosensitive lithographic printing plate of the present invention has a melting point of 40°C.
Paraffins and higher alcohol ester compounds of higher fatty acids in the range of ~200°C are preferred. In particular, the melting point is 50℃~
A temperature of about 150°C is preferable. Specific compounds include natural wax such as carnauba wax, wood wax, sugar beeswax, spermaceti wax, beeswax, cinnamon wax, lanolin, sheep wax, petroleum wax such as paraffin wax,
Microlithrin, wax, etc., and other montan wax,
Examples include ozolite.

Examples of synthetic waxes include carbowax, low molecular weight polyethylene wax, and chlorinated naphthalene wax. Examples of higher fatty acid esters of hexyl alcohol include palmitic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, and lauric acid. As a higher fatty acid ester of octyl alcohol,
Examples include palmitic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, lauric acid, and the like.

Examples of higher fatty acid esters of cetyl alcohol include palmitic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, and lauric acid. Higher fatty acid esters of stearyl alcohol include palmitic acid, stearic acid, oleic acid, linoleic acid,
Examples include linolenic acid and lauric acid. Examples of higher fatty acid esters of ceryl alcohol include palmitic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, and lauric acid.

[0012] Examples of higher fatty acid esters of myricyl alcohol include palmitic acid, stearic acid, oleic acid,
Examples include linoleic acid, linolenic acid, lauric acid, and the like. Two or more of these waxes may be mixed. In the photosensitive lithographic printing plate of the present invention, a photosensitive component as described below is coated on a support, and then a wax solution obtained by heating and dissolving the wax compound is applied to the surface of the support having a photosensitive layer. Apply to the top layer on the opposite side.

[0013] As this method, conventionally known roll coating, die coating, spray coating, and dip coating methods can be used. After coating on the support, it was cooled to form a layer of the wax compound. The support used in the photosensitive lithographic printing plate of the present invention includes metal plates such as aluminum plates, iron plates, zinc plates, and copper plates, which are generally known for printing plates, or synthetic resin plates such as polyethylene terephthalate supports. used.

Before coating the photosensitive layer on these supports, the following treatment is performed. The grain treatment includes grains obtained by performing a known graining treatment for planographic printing plates for double printing. Examples include grains subjected to ball polishing graining treatment, brush polishing graining treatment, electrolytic polishing graining treatment using a hydrochloric acid bath or nitric acid bath, or graining treatment using a combination of these.

The effect of improving the susceptibility to scratches during the production of photosensitive lithographic printing plates is more pronounced when the plate has a grained surface than when it has a smooth aluminum surface. Further, the effect of the present invention is particularly large on a support having an electrolytically polished grained surface among the grained surfaces. A conventionally known graining method is applied to the electrolytic polishing graining method. For example, after degreasing an aluminum plate, the current density is 20 A/dm2 to 200 A/dm in a nitric acid bath, preferably 5 to 30 g/L, or a hydrochloric acid bath, preferably a solution containing 5 to 25 g/L of hydrogen chloride. dm2, temperature 2
Electrolytic polishing treatment is performed at 0° C. to 30° C. for a time of 10 seconds to 170 seconds.

The effects of the present invention are particularly interesting on surfaces subjected to graining treatment by electrolytic polishing, such as ease of scratching and consequent stains caused by printing. The reason for this is the finely grained surface structure of electrolytic polishing.
Alternatively, it may be caused by a dense grain structure, but the causal relationship is not clear. When such a grained surface is used as a lithographic printing plate material for double printing, it is generally anodized to improve printing durability, ease of printing, water retention, etc. The same applies. For example, concentration of sulfuric acid or linic acid, etc. 10-50%, current density 1 d
Anodizing treatment is performed at m2 to 10 A/dm2.

The photosensitive layer used in the present invention includes those known as photosensitive layers for negative-type and positive-type photosensitive lithographic printing plates. That is, as a photosensitive composition constituting the photosensitive layer, in the case of a positive type, an 0-quinonediazide compound and an alkali-soluble resin, etc., and in the case of a negative type, a diazonium salt, a polymer compound containing a hydroxyl group, a photopolymerizable composition, a photopolymerizable composition, etc. A crosslinking composition or the like is used.

Examples of the 0-quinonediazide compound include 0-naphthoquinonediazide sulfonic acid ester of m-cresol formalin novolac resin, 0-naphthoquinonediazide sulfonic acid ester of pyrogallol acetone resin, 0-naphthoquinonediazide sulfonic acid ester of resorcin benzaldehyde resin, and 0- O-naphthoquinonediazide compounds such as naphthoquinonediazide sulfonic acid cumylphenol ester and alkali-soluble resins such as novolac resins, styrene maleic anhydride resins, acrylic acid resins, p-hydroxystyrene resins, etc. are preferably used.

As the diazonium salt compound, p-diazodiphenylamine organic sulfonate or hexaph
Inorganic salts such as fluorophosphoric acid, organic sulfonates or inorganic salts of 3-methoxy-4-diazodiphenylamine, and photosensitive compositions containing hydroxy groups include homopolymers such as hydroxyethyl methacrylate and hydroxymethyl acrylate. Alternatively, copolymers with other monomers such as acrylonitrile and acrylic acid are preferably used.

Regarding photosensitive compositions containing these diazonium salts, the occurrence of stains, which is thought to be caused by the adhesion of condensed water due to a sudden increase in temperature, differs markedly depending on the presence or absence of a coating layer, which is an interesting phenomenon. The photopolymerizable composition and photocrosslinking composition used in this photosensitive layer include polyesters containing α,β-unsaturated ketones, polyamides, polycarbonates, acrylic acids such as polyazidostyrene, polyvinyl-p-azidobenzoate, etc. Examples include photosensitive azide compounds such as.

The photosensitive composition is dissolved in a suitable solvent such as methyl cellosolve, ethyl cellosolve, cellosolve acetate, dioxane, acetone, ethylene dichloride, dimethyl formamide, dimethyl sulfoxide, etc., and coated with a conventional coating device such as a roll. A photosensitive lithographic printing plate is manufactured by applying and drying by coating, die coating, spray coating, etc., and then applying a wax compound by the method described above.

As the positive-type or negative-type photosensitive lithographic printing plate, a positive-type or negative-type photosensitive lithographic printing plate that does not require dampening water can also be used. In the case of unnecessary photosensitive lithographic printing plates, epoxy resin,
A photopolymerized photosensitive layer, a silicone rubber layer, and a cover film are coated on the support.In the case of a negative type photosensitive lithographic printing plate that does not require dampening water, an epoxy resin and a σ-naphthoquinonediazide photosensitive layer are coated on the support. , coated with a silicone rubber layer and a cover film.

[0023]

[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. Example 1 After degreasing an aluminum plate with a thickness of 0.24 mm, a 0.24 mm thick aluminum plate was degreased.
In a 5M aqueous hydrochloric acid solution, temperature: 25°C, current density:
Electrolytic polishing was performed at 60 A/dm2 and treatment time: 30 seconds. Then, after desmutting with a 5% aqueous sodium hydroxide solution,

[0024] The aluminum plate was anodized in a sulfuric acid bath, and finally sealed with hot water at 90°C to obtain a grained aluminum plate. The amount of anodic oxide film obtained was 20 mg/d.
It was m2. Subsequently, the following photosensitive solution was applied onto the grained aluminum support using a roll coater and dried at 90° C. for 6 minutes to obtain a photosensitive lithographic printing plate.

[Photosensitive liquid A] Ester compound of naphthoquinone-(1,2)-diazide-(2)-5-sulfonic acid chloride and pyrogallol acetone resin (weight average molecular weight: 1600)
(Condensation rate: 33 mol%)

17g Cresol formalin novolac resin (m-cresol/p-cresol = 6/4 weight ratio)

65
Condensate of gp-cresol formalin novolac resin and naphthoquinone-(1,2)-diazide-(2)-5-sulfonyl chloride
1g

2-Trichloromethyl-5-(p-butoxystyryl)
-1,3,4-oxadiazole

1g
Victoria Pure Blue BOH (manufactured by Hodogaya Chemical Co., Ltd.) 0.9g Rheodol TWO-1
20 (manufactured by Kao Corporation)
0.5g diethylene glycol dimethyl ether 600ml methoxybutanol
400
ml

[0027] The weight of the coating after drying is 22m.
g/dm2. Next, powder of ethyl methacrylate/methacrylic acid (10:1, molar ratio) (average particle size 8μ) was powdered on the photosensitive layer, and then
Heat fusion was performed using a heated roller at ℃. Subsequently, cetyl stearate was thermally melted (70° C.) and then coated on the back side of the photosensitive planographic printing plate using a gravure coater. After cooling, the film hardens and has a film thickness of 522 mg/dm.
A protective layer of 2 was obtained.

The photosensitive lithographic printing plate thus obtained was subjected to printing plate processing using the following printing plate baking processing robot. Equipment: PS-300 (with bending device) manufactured by Dainippon Screen Co., Ltd. Developer: SDR-1 (manufactured by Konica Corporation)

On the other hand, after 1,000 sheets were packed (without the backing paper), they were transported by truck, opened, and observed for the presence or absence of scratches on the photosensitive layer. Furthermore, the photosensitive printing plate was stored under thermostatement (55°C
, 7 days) and plate making was performed in the same manner. Subsequently, printing was performed under the following conditions, and the presence or absence of stains was observed and printing durability was evaluated.

[Printing Conditions] Printing machine: Heidel GTO Printing ink: Mark Five (manufactured by Toyo Ink Co., Ltd.) Printing paper: High quality paper The results are shown in Table 2.

Examples 2 to 7 Photosensitive lithographic printing plates were produced in the same manner as in Example 1, except that the cetyl stearate in Example 1 was changed to the compounds shown in Table 1. The results are shown in Table 2.

Examples 8 to 10 The sealing solution for the grained aluminum plate of Example 1 was changed from hot water to a 1% (by weight) solution of sodium metasilicate.
Also, change the photosensitive solution to the next photosensitive solution B, and change the developer to SDN-21 (
The production was carried out in the same manner as in Example 1, except that the material was changed to (manufactured by Konica Corp.). Note that the wax compounds shown in Table 1 were used. The results are shown in Table-2.

[Photosensitive liquid-B] Copolymer (acid
value = 60, weight average molecular weight = 55000)
50
Hexafluorophosphate of gp-diazodiphenylamine/paraformaldehyde condensate (weight average molecular weight = 2200)
5g

Julimar AC-10L (manufactured by Nippon Pure Chemical Industries, Ltd.)
0.5g Victoria Pure Blue BOH (manufactured by Hodogaya Chemical Co., Ltd.)
0.5g methyl cellosolve

The film thickness of the photosensitive layer of the photosensitive lithographic printing plate (1) obtained in 1000 ml was 18 mg/dm2.

Comparative Example 1 On the back side of the photosensitive lithographic printing plate of Example 1,
Production was carried out in the same manner as in Example 1, except that molten polyethylene was applied at 280° C. in the same manner as described in Example 1 of Japanese Patent No. 570. The results are shown in Table-2. Comparative Example 2, Comparative Example 3 On the back side of the photosensitive lithographic printing plate of Example 1, JP-A-60-7
Coating was carried out in the same manner as in Examples 1 and 2 of Publication No. 3538.

Comparative Example 2 A 20% aqueous solution of a polymer of methyl methacrylate/ethyl acrylate/sodium acrylate (55/30/15 parts by weight) was applied using an electrostatic spray gun and dried for 1 minute at 100°C. Comparative Example 3 2-hydroxyethyl methacrylate copolymer
A 15% by weight solution dissolved in methoxyethanol was applied using a bar coater and dried at 110°C for 2 minutes. Comparative Example 4 A printing plate was obtained in the same manner as in Example 1, except that no treatment was applied to the back surface.

[0037]

[Table 1]

[0038]

[Table 2]

Example 11 A primer solution of the following composition was placed on a degreased aluminum plate using a bubble homogenizer disperser (pressure: 200 kg/c).
m2, manufactured by APV Manton-Gaulin), coated with a wire bar coater, and then coated at 100℃ for 4 hours.
Dry for a minute. The thickness of the primer layer after drying is 14
It was 0 mg/dm2. Subsequently, this primer layer was irradiated for 8 seconds with a high-pressure mercury lamp (1 J/cm2) to cure it.

[Primer liquid formulation] 2-hydroxyethyl methacrylate/methyl methacrylate copolymer (weight average molecular weight: 40,000
, Charge molar ratio: 50/50
100 parts by weight fine zinc white (manufactured by Sakai Chemical Co., Ltd., white pigment)
20 parts by weight Kett Yellow 402 (manufactured by Dainippon Ink Co., Ltd., yellow pigment) 10 parts by weight Pentaerythritol tetraacrylate
100 parts by weight

DETX (manufactured by Nippon Kayaku Co., Ltd., photopolymerization initiator)
5 parts by weight EPA (manufactured by Nippon Kayaku Co., Ltd., photopolymerization initiator)
5 parts by weight emulsified methyl

860 parts by weight cyclohexane

Next, 100 parts by weight of the photosensitive solution shown below was coated on the primer layer using a wire bar coater and dried at 80° C. for 4 minutes. The thickness of the photosensitive layer after drying was 5 mg/dm2.

[Photosensitive liquid formulation] 4-hydroxyphenyl methacrylamide/2-hydroxyethyl methacrylate/methyl methacrylate copolymer (weight average molecular weight: 40,000, preparation
Molar ratio: 20/50/30)
100 parts by weight p
-Hexafluorophosphate of paraformaldehyde condensate of diazodiphenylamine

50 parts by weight Orange IV

5 parts by weight methyl lactate

2000 parts by weight of silicone rubber liquid with the following composition was applied to a coating weight of 20 m after drying.
It was coated so that it was applied at a concentration of g/dm2.

[Silicone rubber liquid formulation] Dimethylpolysiloxane having hydroxyl groups at both ends (weight average molecular weight: 40,000)

100 parts by weight triacetoxymethylsilane
1
0 parts by weight dibutyltin laurate

0.8 parts by weight Isopar E (manufactured by Esso Chemical Co., Ltd.)
900 parts by weight

Next, a single-sided matted polypropylene film having a thickness of 6 μm was laminated on the silicone rubber layer to prepare a sample of a photosensitive lithographic printing plate that did not require dampening water. Next, in the same manner as in Example 1, a wax compound was applied to the back surface of the aluminum plate. After a positive film was vacuum-adhered to the upper surface of the above plate material, it was exposed to light at 230 mJ/cm2 using a metal halide lamp as a light source.

The plate material thus obtained was developed at 30°C using the following developer and the following automatic developing machine.
The unexposed portions of the silicone rubber layer and the photosensitive layer were removed, and a printing plate with well-reproduced halftone dots was obtained. The image area of the above printing plate could be vividly dyed by applying a dyeing solution of the following composition to a cloth, lightly rubbing the plate, and then washing with water.

[Developer-1] β-anilinoethanol
0
．． 5 parts by weight propylene glycol

1.0 parts by weight p-tert-butylbenzoic acid
1.0 parts by weight potassium hydroxide
1.
0 parts by weight

Polyoxyethylene lauryl ether
0.1 parts by weight Potassium sulfite

2.0 parts by weight Potassium metasilicate

3.0 parts by weight water


91 parts by weight Automatic developing machine: PS plate automatic developing machine PSK-
910 (manufactured by Konica Corporation)

[Staining solution] Solfit (manufactured by Clarei Soprene Chemical Co., Ltd., solvent)
20 parts by weight Rheodor TW-01
20 (manufactured by Kao Corporation, surfactant) 0
．． 5 parts by weight benzyl alcohol

5.0 Part by weight Victoria Pure Blue BOH
1.0 parts by weight water

1
00 parts by weight Also, there were no transportation troubles in the automatic developing machine during the above-mentioned work.

[0049]

Effects of the Invention Since the photosensitive lithographic printing plate of the present invention is constructed as described above, even when the finished printing plate is processed by a printing material robot, it has good smoothness, so there is no trouble in conveyance, and it is easy to stack. It can be packaged. In addition, even if stored in a stacked state, the wax layer does not use a solvent and is applied at low temperatures.
It does not elute or decompose photosensitive components and has excellent storage stability.

Claims (2)

[Claims] 1. A photosensitive lithographic printing plate having a photosensitive layer on one side of a support, characterized in that the outermost layer of the support on the side opposite to the side having the photosensitive layer contains a wax compound. Print version. [Claim 2] After heating the wax compound and making it liquid,
1. A method for producing a photosensitive lithographic printing plate, comprising applying the wax compound to the opposite surface of the support to the surface having the photosensitive layer, and solidifying the wax compound by cooling to form a wax layer.