JP2900423B2 - Printing plate material - Google Patents

Description

The present invention relates to an improvement in a printing plate. In particular, the present invention relates to an improvement in a lithographic printing plate used as a material for producing a lithographic printing plate using an oil-based ink.

[Conventional technology]

Plates used for letterpress printing are classified into letterpress, planographic, and intaglio. The relief printing plate is a printing plate in which only the area to which the oil-based ink is attached protrudes in a convex shape, and printing is performed only in the protruding area, and is used for general printing. ) Is large. In the lithographic printing plate, the surface of the plate is flat, but only the area where printing is performed is regarded as an oil-sensitive area, oil-based ink adheres only to this area, and the other areas are regarded as non-oil-sensitive areas. The plate is designed so that oil-based ink is prevented from adhering to the region, and printing is performed only by the oil-sensitive region, and has a feature that printing durability is low, but plate making cost is low. The intaglio is a plate in which only the area where printing is performed is a recess, and the recess is filled with oil-based ink, and printing is performed with a large amount of oil-based ink. It has the feature that a printed image can be obtained. As described above, the present invention is an improvement of a printing plate material used as a material for manufacturing a lithographic printing plate using oil-based ink. In the lithographic printing method, a lipophilic area (lipophilic area / ink receiving area) made of a colloid such as aluminum hydroxide and an Arabic rubber are formed on a partial area of a plate material in accordance with a pattern of an image to be printed. And oil-insensitive areas (oil-phobic areas and ink repellent areas) made of silicone rubber, fluororesin, etc. The former uses oil-based printing inks, while the latter repels oil-based printing inks. is there. As described above, in the lithographic printing plate, the printing area is defined as the oil-sensitive area, and the non-printing area is defined as the non-oil-sensitive area. However, this selective area division must be permanent. Typographic printing requires the use of a single plate to perform an extremely large number of prints. The printing durability (number of printable times) is determined by how long a specific area is kept oil-sensitive or non-oil-sensitive for a long time, and is an important evaluation item for evaluating a lithographic plate.
Therefore, the ability to permanently change and maintain a specific region to be oil-sensitive or non-oil-sensitive is a very important property for a lithographic material.

The lithographic printing method was developed from the lithographic printing method,
In the early plate making process, handicraft techniques were mainly used, but the development of photographic technology led to the development of photo plate making methods. Now being used. Hereinafter, a photolithographic method according to the related art will be described with reference to the drawings.

Referring to FIG. 3, reference numeral 5 denotes a metal substrate, for example, a planographic plate of zinc, aluminum or the like is used. Reference numeral 6 denotes a photoreceptor layer baked on the substrate surface by irradiation with ultraviolet light or the like,
In order to form the photoreceptor layer 6, the surface of the substrate 5 is polished and polished with a lapping solution (removal of polishing mud and oxide film, etc.). A non-exposed photoreceptor layer is formed by applying a photosensitive solution mixed and dissolved in a colloid aqueous solution, and an area corresponding to the pattern of the printed image or an unexposed area is exposed, and only the exposed and exposed area is altered, After the development, the photosensitive layer 6 is left only in the exposed area or the unexposed area (the area corresponding to the pattern of the print image). Reference numeral 7 denotes a developing ink layer. Of the developing ink layer 7 which is thinly applied on the entire surface of the substrate 5 after the above-described developing step, the developing ink layer 7 is not washed away by a water washing step as a subsequent step and forms a printed image pattern. This is the developing ink layer remaining in the corresponding area. The area of the developing ink layer 7 is oil-sensitive (lipophilicity / ink acceptability).
It constitutes the area and becomes the receiving layer for the printing ink. Reference numeral 8 denotes a layer of a hydrophilic colloid substance, for example, gum arabic, which has been removed from the photoreceptor layer by the above-described developing step, and further has the developing ink layer removed by the washing step and adsorbed on the exposed metal surface. This region constitutes a non-greasy (lipophobic, ink repellent) region for preventing the adsorption of the fatty printing ink, and serves as a repellent layer of the printing ink.

In order to perform lithographic printing using the lithographic plate manufactured in the above process, first, a fountain solution process is performed on the lithographic printing plate to perform printing with an oil-insensitive (oleophobic, hydrophilic, ink repellent) region. Water is adhered to the surface of the ink repellent layer, and then the ink is adhered only to the surface of the printing ink receiving layer composed of oil-sensitive (hydrophilic / ink-receptive) regions. Third, the ink is applied to paper or the like. Transcribe.

As mentioned above, traditional lithographic printing methods were based on the use of water, so some process disadvantages were unavoidable. The lithographic printing method developed to remedy this drawback is the so-called waterless lithographic printing method or dry lithographic printing method, which is a lithographic printing method using no dampening solution. In the waterless lithographic printing method, there was a pantone process that used the ink repellency of amalgam in the old days, but now the ink repellency of silicone rubber ink developed independently by Dai Nippon Printing Co., Ltd. and Toray Co., Ltd. There is known a waterless lithographic printing method utilizing the property. In the former, the silicone rubber itself has photosensitivity, and in the latter, photo-adhesion by a photopolymer is applied to image formation. In addition, recently, at Print '80 held in Chicago in 1980, 3M used a “Dry Duplicating System” using fluororesin as an ink repellent substance.
m "has been announced.

[Problems to be solved by the invention]

As described above, the lithographic printing method started from the lithographic printing method, and has been developed to the photolithographic printing method. Improvements in printing accuracy, simplification of the printing process, and the like have been achieved, and great progress has been made. However, as described above, the photosensitive solution used in the lithographic manufacturing process according to the prior art is mainly composed of an aqueous colloidal solution of an organic substance, and its particles are large, and the resolution of a printed image is not always satisfactory. In addition, silicone rubber or fluororesin is used as a material constituting a non-greasy (lipophobic, ink repellent) area of a lithographic plate used in a so-called waterless lithographic printing method or a dry lithographic printing method. In spite of the fact that it should not be done, unless the material forming the ink repellent area is improved, it is inevitable that there is little possibility of technical development for further improving the characteristics. Therefore, in order to further reduce the price of the plate material, further simplify the printing process, further improve the resolution and accuracy, and remove the limits of technical development to further improve the characteristics, a technology different from the technical idea on which the conventional technology relies The development of lithographic materials based on ideas was desired.

An object of the present invention is to meet this demand and to provide a lithographic printing plate that relies on a technical idea different from the technical idea on which the prior art relies.

[Means for solving the problem]

The present invention utilizes the property that when polysilane is exposed to ultraviolet light having a wavelength of 300 to 400 nm, it permanently changes from a lipophilic substance to a non-liposensitive substance and is permanently held in that state. Is a printing plate material in which a polysilane film (2) is formed on a substrate (1). The printing plate material is formed by using the above-mentioned polysilane film (2) by using ultraviolet rays of 300 to 400 nm. ) Is used as a material for producing a lithographic plate for printing using oil-based inks, that is, as an intermediate, by partially exposing the exposed area to a non-oil-sensitive area from an oil-sensitive area. It is.

The polysilane, which is a material of the photoreceptor layer constituting the printing plate material according to the present invention, is generally represented by a polymer, particularly by the following formula. Includes homopolymers, copolymers, or terpolymers.

However, in the formula, R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , and R ₆ are selected from the group consisting of an alkyl group, an aryl group, a substituted alkyl group, a substituted aryl group, and an alkoxy group. , M, n, and p are numbers (mol%: hereinafter abbreviated as%) indicating the proportion of each monomer unit in the whole polymer composition, and the sum of m + n + p is equal to 100%; Or p can each be 0-100%. Each of the monomer units of the polysilane is randomly distributed throughout the polymer, or has a block shape with a variable amount. The weight average molecular weight of this polysilane is preferably 1,
000 or more, more preferably, the lower limit is 1,000 as described above.
, But the upper limit is 2,000,000.

Examples of the alkyl group in the substituent represented by R in the above general formula include linear or linear groups having 1 carbon atom to about 24 carbon atoms, preferably 1 to 8 carbon atoms. A branched alkyl group, for example, a methyl group, an ethyl group,
Propyl group, butyl group, amyl group, hexyl group, octyl group, nonyl group, decyl group, pentadecyl group, stearyl group, or unsaturated alkyl group including allyl group,
And there are other similar substituted alkyl groups. Particularly preferred alkyl groups are a methyl group, an ethyl group, a propyl group, and a butyl group. Aryl substituents have from 6 to about 24 carbon atoms and include phenyl, naphthyl, and anthryl. These alkyl and aryl groups can be substituted with alkyl groups, aryl groups, halogen groups, nitro groups, amino groups, alkoxy groups, cyano groups, and other related substituents.

Examples of alkoxy groups are those having 1 to about 10 carbon atoms, such as methoxy, ethoxy, propoxy, butoxy, and other similar substituents.

It is effective as a material of the photoreceptor layer constituting the printing plate material according to the present invention, and specific examples of the polysilane included in the above general formula include poly (methylphenyl) silane and poly (methylphenylsilylene- Polysilane having a phenyl group, such as co-dimethyl) silane, poly (phenylethyl) silane, poly (p-tolylmethyl) silane, poly (diphenylsilylene-co-phenylmethyl) silane, poly (cyclohexylmethyl) silane, poly (tercia) L-butylmethyl) silane, poly (n-propylmethyl)
Silane, poly (cyclotrimethylene) silane, poly (cyclotetramethylene) silane, poly (cyclopentamethylene) silane, poly (di-t-butylsilylene-co-dimethyl) silane, poly (cyanoethylmethyl) silane,
Poly (2-acetoxyethylmethyl) silane, poly (2
(Carbomethoxyethylmethyl) silane and the like, and a polysilane having a phenyl group is particularly preferred.

These polysilanes can be synthesized by a known method (for example, RCWest, Comprehensive Organic Che
mistry, Vol.2, Chapter 9.4, P. 365-387 (1982), edited
by G. Wilkinson et al., Pergamon Press, New York).

A lithographic plate manufactured using the printing plate material according to the present invention is:
Of course, it can be used in a normal lithographic printing method using a dampening solution, but has the advantage that it can also be used in a so-called waterless lithographic printing method or a dry lithographic printing method.

Further, the following materials may be mentioned as materials of the photoconductor layer that can function similarly to the photoconductor layer constituting the printing plate material according to the present invention.

I. Polyvinyl carbazole b. Amine derivative For example, a triphenylamine derivative having the following structural formula C. Hydrazone derivatives For example, hydrazone derivatives having the following structural formula D. Pyrazoline derivative For example, a pyrazoline derivative having the following structural formula Any of these photoreceptor layer materials can be synthesized by a known method.

It has been experimentally confirmed that, even when any of the above materials is used, effects substantially similar to the effects specific to the printing plate material according to the present invention can be obtained. Has been confirmed. Further, each material may be used alone or in combination. Further, 2,4,7-trinitro-9-fluorenone, m-dicyanobenzene, tetracyanoethylene and the like can be further contained in these materials as secondary agents. The content of these secondary agents is preferably 50% or less, more preferably 20%
It is as follows.

These photoreceptor layers can be formed by a known method even when any of the above materials is used. For example, a roll coating method or the like can be used.

Regardless of which material is used, the thickness of the photoreceptor layer constituting the printing plate having these photoreceptor layers is preferably several μm to several tens μm.

Further, as a substrate constituting these printing plate materials,
Paper, polyester, polyimide, etc. can be used.

[Action]

According to the present invention, when the polysilane is irradiated with ultraviolet light of 300 to 400 nm, the region irradiated with the ultraviolet light has permanent oil-sensitivity (lipophilicity and oil-based ink receptivity) to non-lipid-sensitive (lipophilicity and oil-based ink repellency). It uses a newly discovered law of nature that changes dynamically. The discovery of this law of nature has been confirmed based on a huge number of experimental results,
Regarding the chemical mechanism that changes from lipophilicity (lipophilicity and ink receptivity) to insensitivity (oleophobicity and ink repellency), despite the intensive research at present,
Unfortunately, it is not always clear.

A lithographic plate manufactured using the printing plate material according to the present invention is:
Of course, it can be used in a normal lithographic printing method using a dampening solution, but has the advantage that it can also be used in a so-called waterless lithographic printing method or a dry lithographic printing method.

Similar characteristics have been experimentally confirmed for materials such as polyvinyl carbazole, amine derivatives, hydrazone derivatives, and pyrazoline derivatives in addition to polysilanes.

〔Example〕

Hereinafter, a printing plate according to an embodiment of the present invention will be described with reference to the drawings.

See FIG. 1. On the surface of paper 1 having a thickness of 1 mm serving as a plate material substrate, polymerized using metallic sodium in toluene using the method of West et al., Which uses methylphenyldichlorosilane as a raw material. A lithographic plate obtained by dissolving the obtained polysilane having a weight average molecular weight of about 10,000 in benzene, applying the solution using a roll coating method, and then drying it to form a photoreceptor layer 2 having a thickness of 10 μm. Plate material was manufactured.

Referring to FIG. 2, a photo master 3 representing a print image is opposed to the photoreceptor layer 2 of the lithographic printing plate materials 1 and 2 manufactured as described above. 4
(Wavelength: 300 to 400 nm) to convert the irradiated area of the photoreceptor layer 2 from lipophilic (lipophilic, ink receptive) to non-lipid (lipophobic, ink repellent) to produce a lithographic plate. . In the figure, reference numeral 21 denotes an oil-sensitive (lipophilic / ink-accepting) region representing a region not exposed in the above-described ultraviolet irradiation step (black region of the printed image pattern);
Are areas that have been exposed to light in the above-described ultraviolet irradiation step and have been converted into oil-insensitive (oleophobic, ink repellent) areas (areas where white paper remains in the printing step).

This lithographic printing plate can be used in a normal lithographic printing method using a dampening solution, but has the advantage that it can be used in a so-called waterless lithographic printing method or a dry lithographic printing method.

As described above, as a material for the photoreceptor layer 2, a printing plate material is prepared by replacing polysilane such as methylphenyldichlorosilane with polyvinylcarbazole, a triphenylamine derivative which is one kind of amine derivative, hydrazone derivative and the like. It has been confirmed that the same operation and effect are obtained in both cases, regardless of whether they are manufactured.

Among the above, some of the above become hydrophilic and ink-receptive by ultraviolet irradiation, but do not necessarily show excellent oleophobicity and ink repellency. Although they can be used satisfactorily as plate materials, they do not always provide satisfactory results as lithographic plate materials without water. But,
All of the above have been experimentally proven to be sufficiently usable as a lithographic printing plate having at least a fountain solution step.

〔The invention's effect〕

As described above, the printing plate material according to the present invention is a planographic printing plate material in which a polysilane photoconductor layer having a film thickness of several μm to several tens μm is formed on a substrate such as paper. Is a plate material that relies on a completely different technical concept from the printing plate material according to the above. By simply irradiating an energy beam such as ultraviolet light with a photomask facing the plate material, a non-greasy (lipophobic, ink-repellent, (Repulsion) region, and as a result, a lithographic plate can be realized. The plate material price is low. The printing process is simple, c. The resolution has been improved. It is possible to provide a printing plate material that is highly likely to be improved in the future. A lithographic plate manufactured using this printing plate material can be used for a normal lithographic printing method using a dampening solution, but can also be used for a so-called waterless lithographic printing method or a dry lithographic printing method. There is a benefit that you can do.

Incidentally, instead of polysilane as a material of the photoreceptor layer according to the gist of the printing plate material according to the present invention, polyvinyl carbazole, triphenylamine derivative which is one kind of amine derivative, hydrazone derivative, etc. Oops,
It has been confirmed that there is a similar effect.

[Brief description of the drawings]

FIG. 1 is a sectional view of a lithographic printing plate according to one embodiment of the present invention. FIG. 2 is an explanatory view of a step of irradiating a lithographic plate material according to one embodiment of the present invention with ultraviolet rays to form an ink repellent layer in an ink receiving layer corresponding to a print image pattern. is there. FIG. 3 is a sectional view of a planographic plate according to the prior art. 1 ... substrate for plate material made of paper, 2 ... photoreceptor layer, 21 ...
Oil-sensitive (lipophilic / ink-receptive) area, 22 ... Insensitive (oil-phobic / ink-repellent) area, 3 ... photomask,
4 ... ultraviolet light, 5 ... metal substrate, 6 ... baked photoreceptor layer, 7 ... developing ink, 8 ... hydrophilic colloid substance (for example, gum arabic).

Claims (1)

(57) [Claims] 1. A polysilane film (2) is formed on a substrate (1). The polysilane film (2) is partially exposed to light, and the exposed areas are shifted from oil-sensitive areas to non-oil-sensitive areas. A printing plate material used as a material for manufacturing a lithographic printing plate made using oil-based ink, which is converted into a domain.