JPS5813906B2 - printing plate material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel printing plate material, and particularly to a printing plate material that is easy to develop after exposure or does not require any development.

The present inventors have developed a printing plate material in which sulfur or a sulfur compound is applied on a substrate such as a metal, either by interposing a water-soluble polymer layer or by dispersing it in a water-soluble polymer. is suggesting.

According to this printing plate material, simply by performing pattern exposure, some change occurs in the surface of the substrate (mainly metal) in the exposed area or in the exposed layer, which becomes hydrophilic and becomes a printing plate. It is something.

The present invention improves practicality by sensitizing such a printing plate material by adding one or both of a photoradical generator and an electron-accepting compound as a sensitizer.

This will be explained in more detail below.

FIG. 1 shows an example of the printing plate material of the present invention. In the figure, the substrate 1 is a copper metal layer, and although it is not clear in the figure, the substrate 1 may constitute a plate-like object by itself. Alternatively, it may be formed by laminating or plating on an arbitrary substrate.

On top of that, sulfur or a sulfur compound is added to the water-soluble polymer layer 2.
Let them coexist inside.

As a means of making them coexist, the most common method is to mix sulfur or sulfur compounds dissolved in a solvent or powdered sulfur or sulfur compounds into an aqueous solution of water-soluble polymers, apply a solution, and dry it. and
In this way, sulfur or a sulfur compound is dispersed in the water-soluble polymer layer 2.

A convenient method for adding a photoradical compound or an electron-accepting compound as a sensitizer is to dissolve or disperse it in the coating solution in the same way as sulfur or sulfur compounds.

FIG. 2 shows a second embodiment of the invention.

According to the figure, a layer 4 of sulfur or a sulfur compound is laminated on a substrate 1 as described above with a water-soluble polymer layer 3 interposed therebetween. is incorporated into the layer 4 of sulfur or sulfur compounds.

A good method for mixing is to dissolve sulfur or sulfur compounds together with a solvent that dissolves sulfur or sulfur compounds, and by applying the resulting solution onto the water-soluble polymer layer 3, the printing material shown in FIG. A plate material is obtained.

Additionally, the thickness of the water-soluble polymer layer 3 affects the sensitivity.

If it is extremely dilute, the dark reaction will proceed, and if it is too thick, the sensitivity will decrease.

A thickness of about 5000A is best.

Sulfur compounds that can be used in the present invention include 2
-(N.N-diethylthiorubamoylthio)penzothiazole, 2-(2'.4'-dinitrophenylthio)
Penzothianol, dibenzothiazyl disulfide, dimethyldithiocarbamate metal salt, tetramethylthiuram monosulfide, tetramethylthiuram disulfide,
Tetraethylthiuram disulfide, tetrabutyltheuram disulfide, dipentamethylenethiuram tetrasulfide, zinc ingropil xanthate, zinc butyl xanthate, N. N-diisoprobyl-2-penzothiazolylsulfenamide and the like can be mentioned.

Chloroform, verchlorethylene, trichloroethane, trichlorethylene, carbon tetrachloride, toluene, etc. can be used as a solvent for these sulfur compounds including sulfur.

Further, examples of water-soluble polymers include xanthan gum, polyethylene oxide, hydroxyethylcellulose, hydroxyglobil cellulose, polyvinylpyrrolidone, gum tragacanth, guar gum, polyvinyl alcohol, carboxynotylcellulose, and the like.

Of course, the above-described sulfur compound, solvent, or water-soluble polymer is just one example, and there are of course others that can be used, and those skilled in the art may select and use them as appropriate.

On the other hand, examples of photoradical generating agents that can improve photosensitivity include carbon tetrabromide, 2-methyl-4,6-di(tribromomethyl)-8-1 riazine, and 1-(tribromomethyl)inquinoline. , hexabromoethane, pentachlorophenol, pentabromoethane 6-nitro 2-(}ribromomethyl)quinoline, tribromomethylphenylsulfone, 2-(toJbromomethyl)penzothiazole, 4
Nitro-1-}ribromomethylbenzene, 2,6-dibromo-4-nitrophenol, trichloromethanesulfonyl chloride, 2.4,6-tri(dibromomethyl)-8-}riazine, tribromoacetophenone ,2
．． 3.4.4-tetrachloro-1.4-dihydronaphthalen-1-one, 3.3.3-}lichloro-2.2-dihydroxyprohionic adi}, 2-(}libromomethyl)quinoline, 2. 4.6-}li(dibromomethylene)trithiane, iodoform, 8-nitro-2-(tribromomethyl)quinoline, 2.4.6-}li(tribromomethyl)-S-}lyazine, 2.2. 3.4.4-pentachloro-1.2.3.4-tetrahydronaphthalen-1-one 4-nitrobenzoyl bromide, etc. can be used, and is separated by light irradiation, thereby removing sulfur compounds. Any material that can be used to separate the molecules and thereby speed up the reaction can be used.

Further, as electron-accepting compounds, P-penzoquinone, nitro-P-penzoquinone, cyano-P-penzoquinone, fluoro-P-penzoquinone, chloro-rp-penzoquinone, bromo-P-penzoquinone, iodo-P-penzoquinone, phenyl-P-penzoquinone, Methylparabenzoquinone, menoxy-P-penzoquinone, 2.3-dichloro-P-penzoquinone, 2.5-dichloro-P-benzoquinone, 2.6-dichloro-P-penzoquinone, 2.3
-) Cyano P-penzoquinone, trichloro P-penzoquinone, 2,3-dichloro-5,6-dicyano P-
penzoquinone, chloranil, bromanil, iodanyl,
0-chlora=k, 0-bromanyl, 1.3-dinitrobenzene, 1.4-dinitrobenzene, 1.3.5-}linitrobenzene, 2.4.7-trinitrofluorenone, 2.4.6- }Linitrofluorenone, 1.3.5-
Tricyanobenzene, 1.2.4.5-tetracyanobenzene, pyromellitic dianhydride, tetrachlorophethene quanhydride, malate quanhydride, dichloromalate quane hydride, tetracyanoethylene, 7.7.8 There are compounds such as .8-tetracyanoquinodimethane, which can change the sulfur compound into a photoactive state and improve the sensitivity of the plate material.

Below, the printing plate material of the present invention will be explained in more detail. Although there are many unknowns about the details of the reaction when the printing plate material of the present invention is exposed to light image, a positive image is formed. In this case, the difference in hydrophilicity and hydrophobicity is formed on the metal surface.

After irradiating the printing plate material with light and applying water to the surface,
When trying to apply ink with an ink roller, if a positive image is formed, the sulfur compound and water-soluble polymer group on the metal are removed, and the ink adheres to the surface of the metal substrate in the unexposed area.

Thereby, there is no need to pass the material through the processor currently used when producing lithographic printing plates, and one of the plate production steps can be omitted.

That is, printing is possible by simply attaching the printing plate of the present invention to a printing machine after exposure and applying water to the surface.

In order to examine the hydrophilic and hydrophobic properties of the surface, the contact angle with water on the untreated copper surface was measured with a goniometer and a contact angle measuring device, and it was 65°, but when the surface was sulfurized, it increased to more than 100°. It can be seen that it becomes lipophilic.

However, for example, if the plate material is made of a three-layer structure of copper substrate - hydroxyethyl cellulose dipentamethylene thiuram tetrasulfide, the pattern is adhered, exposed with a mercury lamp, and then inked after applying water, it is not exposed. The ink adheres only to the exposed area, and the contact angle is 30°.
It changed to

In other words, it changed to hydrophilicity due to light irradiation, which was the opposite of the sulfurization reaction.

In addition, this sensor is irradiated with light and then washed to remove the hydroxyethyl cellulose-sulfur compound layer.
After drying this, it is immersed in a sulfur toluene solution to sulfurize the surface, and the unexposed areas to which the ink will adhere will be sulfurized.

However, the exposed portion with the hydrophilic layer was not sulfurized, indicating that the hydrophilic layer prevents sulfurization.

From the above results, it is thought that water-soluble polymers are involved in the reaction, rather than a simple photosulfurization reaction on the copper substrate.

The photosensitivity of the above-mentioned photoreaction resulting in the formation of a positive image was improved by containing a photoradical generator and/or an electron-accepting compound in the sulfur compound.

Figure 3 is a graph showing the improvement in photosensitivity, with the horizontal axis representing the exposure amount (Joule/cr!) and the vertical axis representing the contact angle (degrees) of water on the copper substrate. .

According to this example carbon tetrabromide (CBr4) as a sensitizer
It can be seen that the sensitivity increases by about 10 times or more in the case where 10V and 15g of ions are added as compared to the case where no addition is made.

However, the printing plate material in this case consists of the following coating solution: Coating solution chloroform (solvent)...110g Dipentamethylenethiuram tetrasulfide 51 carbon tetrabromide...Xi (X=o, 10, 15) is a three-layer type product in which a polymer layer of hydroxyethyl cellulose is previously formed on a copper substrate.

Furthermore, Figure 4 shows the synergistic effect when both a photoradical generator (in this case, carbon tetrabromide) and an electron-accepting compound (in this case, trinitrofluorein) are added as photosensitizers. be.

According to the figure, carbon tetrabromide (CBr4) alone (5g added)
and trinitrofluorenone (TNF) alone (0.5
Compared to the one (with P added), the one in which the same amounts of both were added showed an increase in sensitivity of about 8 to 10 times.

However, the printing plate material in this case is prepared by adding 2.4.7-}linitrofluorenone and carbon tetrabromide, either alone or in combination, to a solution of dipentamethylenethiuramte}7 sulfide 5z-chloroform 1101. The obtained photosensitive liquid was dispersed in a 5% aqueous hydroxyethyl cellulose solution at a ratio of 1=3, and this dispersion was applied onto a copper base plate.

The printing plate of the present invention is as described above, and by adding a photoradical generator or an electron-accepting compound, a remarkable sensitizing effect can be obtained, and the sensitivity may be equivalent to that of commercially available PS plates. 《 could be used as a printing plate material with even higher sensitivity.

This makes it possible to shorten the exposure time, and in combination with the simplicity of the development process, it becomes a printing plate material with an extremely simple plate-making process, making it possible to provide a highly practical printing plate material.

In addition, according to the printing plate material of the present invention, rather than immediately applying a photosensitive coating liquid prepared by dissolving a sulfur compound and a sensitizer in a solvent to a plate substrate, it is possible to apply the photosensitive coating liquid for a certain period of time, e.g. A phenomenon was observed in which sensitivity increased when used after being stored for about one month.

Examples of the present invention will be described below.

Example 1 A printing plate material was prepared by applying a coating solution in which 15F of CBr4 was added to dipentamethylenethiuram tetrasulfide 51-chloroform 11IQ photosensitive solution and dispersed in a 5% hydroxyethyl cellulose solution onto a surface-cleaned copper plate. OB
The sensitivity was about 15 times higher than that applied without adding r4.

Example 2 A copper plate was surface-cleaned, and a 3% aqueous solution of Natrosol (trade name) from Hercules was applied thereon and dried.

On top of this, dipentamethylenethiuram tetrasulfide 5
? - A printing plate material coated with 5 tons of tribromophenylmethylsulfon added to a chloroform solution was about 10 times more sensitive than one coated without the addition.

Example 3 Dipentamethylenethiuram tetrasulfide 5 on a copper plate
1. A photoreceptor coated with a chloroform ILOP photosensitive solution with CBr415F added and dispersed in a 5% polyvinyl alcohol aqueous solution has an increase in sensitivity of about 10 to 15 times compared to one coated without CBr4 added. Ta.

(In Example M, instead of the above 5% polyvinyl alcohol aqueous solution, 3% hydroxyglobil cellulose aqueous solution,
A similar increase in sensitivity was obtained even if any one of carboxymethyl cellulose 5% aqueous solution, xanthan gum 3% aqueous solution, polyethylene oxide 3% aqueous solution, tragacanth gum 5% aqueous solution, or guar gum 5% aqueous solution was substituted.

Example 4 Dipentamethylene thiuram tetrasulfide 5? -OB
After storing a photosensitive solution of 110y of r45P-chloroform in a room for one month, it was dispersed in a 5% hydroxyethyl cellulose aqueous solution at a ratio of 1 = 3 and applied on a copper plate. The sensitivity is 1
Example 5 A photosensitive solution in which 415 t of OBr was added to a 3.8N tetraethylthiuram disulfide-chloroform 1101 solution was dispersed in a 5% polyvinylpyrrolidone solution, and the printing plate material was coated on a copper plate with OBr, The sensitivity was about 15 times higher than that produced without the addition of .

Example 6 Dipentamethylenethiuram 51-chloroform 110I
A printing plate material was prepared by adding 0.21% of 2.5 dichloro-P-benzoquinone to the solution and dispersing it in a 5% hydroxyethyl cellulose aqueous solution at a ratio of 1=3 and coating it on a copper plate. It had the same level of sensitivity.

Example 7 A photosensitive solution prepared by adding 0.51 of 2.4.7-}linitrofluorenone to a 5% solution of dipentamethylenethiuram tetrasulfide and 110y of chloroform was added to a 5% aqueous solution of hydroxyethyl cellulose in a ratio of 1=3. The printing plate material dispersed in OBr, 5? It had the same level of sensitivity as the one created by adding this.

Example 8 Dipentamethylene thiuram tetrasulfide 5i-Quo
o$#mu110? @Liquid K2.4.7-} A photosensitive solution prepared by adding linitrofluorenone 0.51 and CBr45'I at the same time was dispersed in a 5% hydroxyethyl cellulose aqueous solution at a ratio of 1 = 3 and applied on a copper plate. The printing plate material used was 2.4.7-trinitrofluorenone CB.
r. The sensitivity was higher than when each was added alone.

Example 9 Tetraethylthiuram disulfide 3.75P and OBr
A printing plate prepared by dispersing a photosensitive liquid consisting of 415S in a 5% aqueous solution of hydroxyethylcellulose and coating it on a copper plate had higher sensitivity than one prepared by dispersing tetraethylthiuram disulfide alone.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the printing plate material of the present invention, FIG. 2 is a sectional view showing an embodiment of the printing plate material of the present invention, and
The figure is a graph diagram showing the sensitization state of the printing plate material of the present invention, and FIG. 4 is a graph diagram showing the sensitization state when two types of sensitizers are added. DESCRIPTION OF SYMBOLS 1... Substrate, 2... Water-soluble polymer layer containing sulfur or a sulfur compound, 3... Water-soluble polymer layer, 4...
A layer of sulfur or sulfur compounds.

Claims (1)

[Claims] 1 Hydroxyethylcellulose, hydroxypropyl cellulose, polyvinyl pyrrolidone, polyvinyl alcohol, carboxymethyl cellulose, xanthan gum, polyethylene oxide, tragacanth gum,
A water-soluble polymer layer of one type selected from guar gum is provided, and a layer of sulfur or a sulfur compound is further provided thereon, or the above-mentioned water-soluble polymer is provided with a layer of sulfur or a sulfur compound dispersed on a copper layer. A printing plate material comprising a layered printing plate material to which one or both of an exchange radical generator and an electron-accepting compound is added.