JPH0212251A - Photosensitive printing plate - Google Patents

Abstract

PURPOSE:To obtain the resistance to pressing and rubbing and to shorten the time for vacuum contact by incorporating an org. solvent which can dissolve or swell a photosensitive layer into an aq. liquid which is sprayed in such a manner that the content thereof attains <5wt.%. CONSTITUTION:The aq. liquid to be sprayed onto the surface of a photosensitive printing plate contains the org. solvent which can dissolve or swell the photosensitive layer; in addition, said liquid is so formed that the content of said solvent attains <5wt.%. An acrylic resin, a copolymer contg. at least one kind of monomer units having a sulfonic acid group, etc., are used as the resin to be dissolved or dispersed into the above-mentioned aq. soln. Additives such as light absorbents, dyes and pigments for various purposes may be added into the coating liquid. The photosensitive printing plate which has the resistance to pressing and rubbing and is short in vacuum contact time is obtd. in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a photosensitive printing plate. More specifically, the present invention relates to a photosensitive printing plate in which a matte layer provided on a photosensitive layer to shorten vacuum adhesion time does not easily fall off due to pressure, rubbing, or the like.

[Conventional technology]

Conventionally, when exposing a photosensitive printing plate to light through an original image, in order to make the original image completely adhere to the surface of the photosensitive layer of the photosensitive printing plate, the photosensitive printing plate and the
A method was used in which the original paintings were placed one on top of the other, and a vacuum was created between the rubber sheet and the pressure-bonded glass to bring them into close contact.

In order to shorten the time required for this vacuum and close contact, a minute pattern consisting of a coated area and a non-coated area was provided on the photosensitive layer by a method such as that described in JP-A No. 51-96604. Photosensitive printing plates are known.

However, when trying to form a minute pattern on the surfaces of both photosensitive layers of a double-sided photosensitive printing plate in which photosensitive layers are provided on both sides of a support using the method described above, the minute pattern is first coated on one side. After drying, a fine pattern must be applied to the other side and dried, which has the drawback of requiring a fairly large-scale apparatus.

Furthermore, the coated portion of the micropattern provided by the above method is often peeled off or crushed because it is rubbed by the conveyance roller during the process until it is cut to a desired size.

JP-A No. 51-98505 discloses that in order to solve the problem that the coating layer for improving vacuum adhesion stains the original film, a wax-like or finely powdered resin with mold releasability is dispersed in a low-boiling organic solvent. A method of applying with air spray is shown. However, since this coating layer has a weak adhesion to the surface of the photosensitive printing plate, it easily falls off, and there is still the problem as described above. Moreover, it is not preferable to use organic solvents entirely from the viewpoint of safety during production. Furthermore, JP-A-55-12974 discloses a method of powdering a solid powder and fixing it onto a photosensitive printing plate using heat. There is a problem in that the mat layer on one side is crushed when it is transported by rollers after it has been applied and before it is cooled, and on the other hand, it is difficult to transport it without using rollers. Furthermore, in order to make powder, the resin must be crushed and classified, resulting in high costs.

So, the Tokukai Showa 5'? Japanese Patent No. 34558 proposes a photosensitive printing plate which is formed by spraying an aqueous liquid in which a resin is dissolved or dispersed onto the surface of a photosensitive printing plate having a photosensitive layer on a support, and then drying the spray. According to this method, it is certainly possible to provide a matte layer even on double-sided photosensitive printing plates with simple manufacturing equipment, and the applied matte layer is resistant to pressure and rubbing, but When a photosensitive layer and a matte layer are coated and wound up while the body remains a coiled web, the back side of the support on which the pine) II is wound, especially near the winding core of the coil, due to the tension of the winding. If you stack around 1,000 plates cut to a specified size without overlapping the backing paper and try to supply them to the user by applying pressure from above to prevent them from shifting, the matte layer will overlap on top of the plates. This has the drawback that the image may be transferred to the back side of the plate support.

Furthermore, JP-A No. 59-219751 proposes a method in which the matting liquid contains 5% by weight or more of a solvent with a boiling point of 130° C. or more in order to increase the adhesion to the photosensitive layer. If a large amount of high boiling point solvent is contained, the high boiling point solvent will not dry completely and will remain in the mat layer, causing the pine) 11 to become plasticized and soft, making it easier to collapse under pressure and reducing the vacuum adhesion time. become longer. Further, if the aqueous solution contains a large amount of solvent, the flash point of the matte solution will be lowered, resulting in an increase in the cost of manufacturing equipment.

[Problem to be solved by the invention]

The object of the invention is to be resistant to pressure and rubbing;
An object of the present invention is to provide a photosensitive printing plate having a short vacuum adhesion time. Another object of the present invention is to provide a photosensitive printing plate that can be manufactured in a safe manner and with simple manufacturing equipment and that has a short vacuum contact time.

[Means to solve the problem]

As a result of various studies, the present inventors have found that the above object can be achieved by adding a small amount of a specific organic solvent to the aqueous matte liquid to be sprayed, and have completed the present invention. That is, the present invention provides a photosensitive printing plate in which an aqueous liquid in which a resin is dissolved or dispersed is sprayed onto the surface of a photosensitive printing plate having a photosensitive layer on a support, and dried. A photosensitive printing plate characterized in that it contains an organic solvent capable of dissolving or swelling the layer, and the content thereof is less than 5% by weight.

Examples of the resin to be dissolved or dispersed in the aqueous liquid include acrylic resins such as those described in JP-A No. 57-34558, acrylic resins such as those described in JP-A-57-58152, and Copolymers containing at least one type of monomer unit having a sulfonic acid group as described in JP-A-58-182636 are preferred, but in addition to these, polyvinyl alcohol, polyvinyl acetate,
Vinyl polymers such as polyvinylpyrrolidone can also be used.

Resins such as those mentioned above may be less than 5% by weight, preferably 0.0% by weight.
The coating liquid is an aqueous liquid containing an organic solvent of 1 to less than 5%, more preferably 0.05 to less than 5%, particularly preferably 0.1 to less than 5%. The properties of the coating liquid vary depending on the type of resin and the combination of organic solvent, so it cannot be specified, but it can take any form of aqueous liquid such as an aqueous solution, an aqueous dispersion, an aqueous suspension, an aqueous emulsion, etc. In addition to the above-mentioned resin, this coating liquid also contains
Light absorbers, dyes, pigments, ultraviolet absorbers, or diazo compounds, ethylenically unsaturated compounds that have optical absorption in the active light region of the photosensitive layer of a photosensitive printing plate as described in the above publication; and furthermore, carbon dioxide. Various fine powders such as silicon, zinc oxide, titanium oxide, zirconium oxide, glass, alumina, and synthetic resins; pH moderators such as phosphoric acid, phosphorous acid, and oxalic acid; such as sodium sulfate, calcium sulfate, magnesium sulfate, and chloride Additives for various purposes, such as neutral salts such as sodium and calcium chloride to promote the precipitation of the copolymer after coating, are added as appropriate.
You can also add an appropriate amount.

Less than 5% by weight in the above aqueous liquid, preferably 0.01-5%
The organic solvent to be contained in an amount of less than 0.05%, more preferably less than 0.05% to less than 5%, particularly preferably less than 0.1% to 5% is not particularly limited as long as it can dissolve or swell the photosensitive layer on which the matte layer is provided. To determine whether the photosensitive layer can be dissolved or swelled, approximately 0.5 In1 drop of an organic solvent is added onto the photosensitive layer.
By leaving it at room temperature for a minute, washing it with water, drying it, and then observing the photosensitive layer with the naked eye, you can easily determine whether there are any changes in appearance such as fading of the dye or peeling of the photosensitive layer film. can. Generally speaking, such organic solvents include methyl alcohol, ethyl alcohol, n-propyl alcohol, iso-propyl alcohol, nibutyl alcohol, acetone, methyl ethyl ketone, benzene, cyclohexane, methyl acetate, ethyl acetate, and isoacetate. -propyl, ethyl formate, propyl formate, isobutyl formate, methyl propionate, dipropionate. chill 1,
Chloroform, carbon tetrachloride, methylene dichloride, ethylene dichloride, 1.1.1-)lichloroethane,
Isopropyl ether, tetrahydrofuran, tetrahydropyran, ethylene glycol dimethyl ether, n
-butyl alcohol, iso-butyl alcohol, methyl n-propyl ketone, methyl n-butyl ketone, methyl iso-butyl ketone, diethyl ketone, toluene, m-
xylene, p-xylene, n-propyl acetate, n-acetate
Butyl, isobutyl acetate, nibutyl acetate, n-formate
Butyl, amyl formate, methyl butyrate, ethyl butyrate, monochlorobenzene, dioxane, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol diethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, methyl-n-amyl ketone, methyl n-hexyl ketone, ethyl n-butyl ketone, di-n-
Propyl ketone, diiso-butyl ketone, acetylacetone, cyclohexanone, methylcyclohexanone, diacetone alcohol, acetonylacetone, o-xylene, n-amyl acetate, in-amyl acetate, methyliso-amyl acetate, methoxybutyl acetate, sec-hexyl acetate,
2-Ethylbutyl acetate, cyclohexyl acetate, methyl acetoacetate, ethyl acetoacetate, n-butyl propionate, n-butyl butyrate, isoamyl butyrate, n-butyl ether, 2-ethoxytetrahydropyran, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl Ether acetate, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monoiso-butyl ether, ethylene, glycol cyphthyl ether, ethylene glycol monobutyl ether acetate, ethylene glycol isoamyl ether, ethylene glycol monohexyl ether, ethylene glycol mono Acetate, ethylene glycol diacetate, methoxymethoxyethanol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol diethyl ether, diethylene glycol monoisopropyl ether, propylene glycol, propylene glycol monomethyl ether acetate, propylene Glycol monoethyl ether acetate, propylene glycol monobutyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, cyfropylene glycol dimethyl ether, dipropylene glycol methyl ethyl ether, dipropylene glycol diethyl ether, hexylene glycol, 3-methoxy- 3-methoxybutanol, N,N-dimethylformamide, dimethyl sulfoxide, T-butyrolactone, γ-valerolactone, ethylene glycol monophenyl ether, ethylene glycol monophenyl ether acetate, ethylene glycol butyric acid diester, ethylene glycol butyric acid monoester, ethylene glycol Propionate diester, ethylene glycol butyrate diester, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether, diethylene glycol monoisobutyl ether, diethylene glycol monobutyl ether acetate, diethylene glycol dibutyl ether, diethylene glycol monoacetate, diethylene glycol diacetate, dipropylene glycol monoacetate Ethyl ether acef-),) diethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monobutyl ether, triethylene glycol dimethyl ether, triglycol dichloride, 1-butoxyethoxypropanol, tripropylene glycol monomethyl ether, tetraethylene glycol dimethyl ether You can mention things like,
It may be selected as appropriate depending on the type of photosensitive layer to be applied. Further, two or more of these can be used in combination as long as the total amount does not exceed 5% by weight.

The aqueous liquid may be produced by first preparing a resin solution and then adding an organic solvent, or by mixing them simultaneously.

The concentration of the resin sprayed onto the surface of the photosensitive layer in the aqueous liquid is preferably in the range of 5 to 30% by weight.

In order to spray such an aqueous resin liquid onto the surface of the photosensitive layer, a known method such as an air spray method, an airless spray method, an electrostatic air spray method, or an electrostatic atomization electrostatic coating method can be used. can.

The aqueous resin sprayed onto the surface of the photosensitive layer is then dried. Drying is usually carried out at room temperature to about 100° C. for 3 to 60 seconds, but it can also be carried out, for example, by blowing hot air.

After drying, the resin attached to the surface of the photosensitive layer has a height of 1 to 20 μm and a size (width) of 20 to 200 μm.
, the number is 1 to 1000 pieces/mm2, preferably 5 to 500 pieces/mm2.
pieces/mm' and ranges from 0.01 to 0.5 g/mm'.
m', preferably in the range 0.02-0.4 g/m'', most preferably 0.04-0.3 g/m''.

By setting it within such a range, the vacuum adhesion time can be shortened and it becomes stable against rubbing pressure.

A photosensitive printing plate, which is the object to which a resin is attached as described above, basically has a photosensitive layer provided on a support. In the case of a lithographic printing plate, the effects of the present invention are significantly exhibited. Various supports for such photosensitive lithographic printing plates are known, and details thereof can be found in British Patent Publication No. 2030.
It is written in Meitosho No. 309A. Further, the photosensitive layer may be made of a diazo resin, an 0-quinonediazide compound, a photosensitive azide compound, a photopolymerizable composition, or a photosensitive resin. These details are also explained in detail in the above-mentioned publication.

Further, when the photosensitive layer contains a diazo resin and a polymer binder, the photosensitive diazo resin is a diazo resin typified by a condensate of an aromatic diazonium salt and an active carbonyl group-containing compound, such as formaldehyde. In particular, organic solvent-soluble diazo (sealing resin) is preferably used.

Examples of the diazo resin include organic solvent-soluble diazo resin inorganic salts, which are reaction products of p-diazodiphenylamine, formaldehyde or acetaldehyde condensate, and hexafluorophosphate or tetrafluoroborate; The condensate and sulfonic acid salts as described in Japanese Patent No. 1167, such as P-)luenesulfonic acid or its salt, propylnaphthalenesulfonic acid or its salt, butylnaphthalenesulfonic acid or its salt, dodecylbenzenesulfonic acid or the salt,
Examples include organic solvent-soluble diazo resin organic salts that are reaction products with 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid or its salts, dioctylnaphthalenesulfonic acid or its salts, or mixtures thereof.

Further, 3-methoxy-4-diazo-diphenylamine as shown in JP-A No. 58-27141, 4.
Mesitylene sulfonate obtained by condensation with 4'-bis-methoxy-methyl-diphenyl ether is also suitable.

In this case, the polymeric binder is preferably one that can be dissolved or swelled in an alkaline aqueous developer and that can be photocured by the photosensitive diazo resin.

Particularly suitable organic polymer binders include acrylic acid,
A copolymer containing methacrylic acid, crotonic acid or maleic acid as an essential component, such as 2-hydroxyethyl acrylate or 2-hydroxyethyl methacrylate, acrylonitrile or methacrylonitrile as described in Japanese Patent Publication No. 52-7364. , a multicomponent copolymer of acrylic acid or methacrylic acid and optionally other copolymerizable monomers, JP-A-53-12090
Acrylic acid or methacrylic acid, acrylic acid, which has a hydroxyl group at the end and is esterified with a group containing a dicarboxylic acid ester residue, as described in Publication No. 3.
or a multi-component copolymer of methacrylic acid and other copolymerizable hetamines as necessary, Japanese Patent Publication No. 57-4.389
A monomer having an aromatic hydroxyl group at the end as described in Publication No. 0 (for example, N-(4-hydroxyphenyl)
acrylic acid or methacrylic acid and optionally other copolymerizable monomers, alkyl acrylates, acrylonitrile or methacrylic acid as described in JP-A-56-4144. Multi-component copolymer consisting of lonitrile and unsaturated carboxylic acid, JP-A-61-267042, JP-A-61-1
Modified polyvinyl acecool resin as described in No. 28123 and No. 62-58242, JP-A-62-1
No. 23452, No. 62-123453, Patent Application No. 1982-
Polyurethane resins such as those described in No. 121666 can be mentioned.

In addition, acidic polyvinyl alcohol derivatives and acidic cellulose derivatives are also useful. Also useful is a polymer compound described in British Patent No. 1370316 in which polyvinyl acecool is solubilized with an alkali.

The thickness of the photosensitive layer is generally 0.1 to 7 g dry weight per side.
/ m', preferably 0.5-3 g/mj.

〔Effect of the invention〕

By employing the configuration of the present invention, a photosensitive printing plate that is resistant to pressure and rubbing and has a short vacuum adhesion time can be obtained. Also, in the manufacturing process, coating can be performed using safe and simple equipment.

Examples of the present invention will be specifically shown below, but the present invention is not limited thereto.

Example L 2 and Comparative Examples 1 to 4 Aluminum plate with a thickness of 0.3+na+ (JIS A1
The surface of the 050 material) was grained using a nylon brush and an aqueous suspension of 400 mesh pumice stone, and then thoroughly washed with water. This was etched by immersing it in a 10% aqueous sodium hydroxide solution at 70°C for 60 seconds, then washed with running water, and after neutralizing with 20% nitric acid, JP-A-53-67
Electrochemical surface roughening method described in No. 507, that is, va=t
Electrolytic surface roughening treatment was carried out in a 1% nitric acid aqueous solution using a sinusoidal alternating waveform current of 2.7 V, Vc = 9.1 V, and an electric charge of 160 corons/dm2 at intervals. Continued 30%
It was immersed in a sulfuric acid aqueous solution and desmutted for 2 minutes at 55°C, and then anodized in a 7% sulfuric acid aqueous solution to a thickness of 2.0 g/m. % aqueous solution for 1 minute, washed with water and dried.

The following photosensitive solution was applied to the aluminum plate obtained as described above using a wheeler and dried at 80° C. for 2 minutes. The coating overlap was 1.5 g/rn'
＼ Photosensitive liquid polymer (a) Malic acid 5.0 g O,05 g 1-methoxy-2-propatol 60 g
Methanol 20 g Methyl ethyl ketone 20 g Polymer (a) is a polyurethane resin having carboxyl groups and hydroxyl groups synthesized in the same manner as Synthesis Example 9 of JP-A-62-123453.

Next, at room temperature, 75.8 g of pure water, 4 g of 1-methoxy-2-propanol, 20 g of polymer (b),
0.2 g of tartrazine was added in this order and stirred for 1 hour to obtain an aqueous matte liquid.

In the same manner, matte liquid B shown in Table 1 was prepared. Furthermore, as a matte liquid for comparison, matte liquid C- shown in Table 1 was used.
E was prepared similarly. Here, the polymer (b) is 2-acrylic sodium 2-methylpropanesulfonate/ethyl acrylate/methyl acrylate=15/
It is a copolymer of 30155 mol%.

Incidentally, all matte liquids were in the form of a solution.

The above water-based matte liquids A and B were applied to the surface of the photosensitive lithographic printing plate obtained earlier at a solid concentration of 20% by weight using electrostatic air spray, and dried at 60° C. for 5 seconds. Examples 1 and 2 were used.

Similarly, Comparative Examples 1 to 3 were prepared using matte liquid C-E.

The amount of matte liquid applied is 0.15g/m", 50~
There were 100 7 mm" droplets, and the height of the matte layer after drying was 2 to 6 μm, and the width was 20 to 150 μm. In addition, a photosensitive lithographic printing plate without a matte layer was prepared as Comparative Example 4. did.

In addition, about 0.0
．． Dissolution of the photosensitive layer was observed with the naked eye by dropping 5 d of the solution, leaving it at room temperature for 1 minute, washing with water, and drying.However, even when a similar test was performed using ethylene glycol, no photosensitive layer was observed with the naked eye. No change was observed in the layer.

The vacuum adhesion time of these photosensitive planographic printing plates was determined under the conditions of plate size 1003 x 800 111 111% and film size 550 x 650 ohm.P manufactured by Fuji Photo Film Co., Ltd.
The results measured using S light are shown in [Table 1]. Furthermore, after stacking 1,000 of these photosensitive lithographic printing plates without a mount, placing a 200 kg weight on top, and leaving them in a room for 30 minutes, what percent by weight of the matte layer on the bottom plate was immediately determined? Table 1 shows the results of measuring transfer to the back surface of the support of the upper plate using a weight.

From Table 1, it can be seen that Comparative Example 4 without mat 1 takes a long time for vacuum adhesion. In addition, in Comparative Example 3, a large amount (20% by weight) of a high boiling point solvent (diethylene glycol monomethyl ether, boiling point 194°C) was added to the matte liquid, making the matte layer soft and easily crushed by pressure.
The vacuum adhesion time is longer than those coated with A-D matte liquid. Comparative Example 1.2, in which no organic solvent that would dissolve or swell the photosensitive layer was added, had a high matte transfer rate, whereas the photosensitive lithographic printing plates coated with matte liquids A and B of the present invention had It can be seen that both the vacuum adhesion time and the matte transfer rate are excellent.

Examples 3 to 5 Polymer (C) was used instead of polymer (C) in Example 1.
) A photosensitive lithographic printing plate was prepared in the same manner as in Example 1 except that the following was used. However, polymer (C) is
This is a modified polyvinyl butyral resin synthesized in the same manner as No. 28123 Synthesis Example 4. An aqueous matte solution having the composition shown in Table 2 was applied to this photosensitive planographic printing plate by electrostatic air spray in the same manner as in Example 1, and then dried.

When 1-methoxy-2-propatol, dimethylformamide, and ethylene glycol diethyl ether were tested in the same manner as in Example 1, it was observed that all of them clearly dissolved the photosensitive layer.

When the transfer rate of the matte onto the back surface of the support of these photosensitive planographic printing plates was measured in the same manner as in Example 1, it was 1% by weight or less in all cases, and there was very little matte removal. In addition, there were no problems in plate making and printing, and good results were obtained.

Examples 6 to 9 and Comparative Example 5 Aluminum plate with a thickness of 0.24 mm (JIS A105
Both sides of the material (0 material) were treated in the same manner as in Example 1. However, no treatment with sodium silicate was performed.

The following photosensitive solution was applied to this support one side at a time and dried to prepare a double-sided photosensitive lithographic printing plate. The dry coating weight of the photosensitive layer was 1.8 g/m'' per side.

"Oil Blue #603" ・0.02 g Methyl ethyl ketone ・8 g 2-methoxyethyl acetate ・ ・15 g Matte liquids ■ to L having the composition shown in Table 3 were applied by electrostatic air spray to both sides of this photosensitive lithographic printing plate. Examples 6 to 9 were obtained by drying at ℃ for 5 seconds. Similarly, Comparative Example 5 was prepared using matte liquid M that did not contain an organic solvent.

As a result of the same test as in Example 1, it was observed that methyl cellosolve, methyl cellosolve acetate, dimethyl sulfoxide, and phenyl cellosolve easily dissolved the photosensitive layer.

Table 3 shows the stains on the transport roll when these samples were brought into repeated contact with the transport roll.

From the above examples, the photosensitive printing plate of the present invention has a matte layer that adheres extremely firmly to the photosensitive layer, so it does not fall off due to pressure or rubbing, and it can be manufactured using safe and simple equipment. It can be seen that it is possible and extremely excellent.

Claims (1)

[Claims] In a photosensitive printing plate formed by spraying an aqueous liquid in which a resin is dissolved or dispersed onto the surface of a photosensitive printing plate having a photosensitive layer on a support and drying, the aqueous liquid dissolves or disperses the photosensitive layer. 1. A photosensitive printing plate comprising a swellable organic solvent, the content of which is less than 5% by weight.