JPH0911655A - Direct drawing type planographic printing plate material and planogrpahic printing plate using the same - Google Patents

Abstract

PURPOSE: To reduce the undulation phenomenon of a plate material as a whole by providing a curable resin layer with specific pencil hardness on at least the single surface of a plastic film. CONSTITUTION: Curable resin layers 3 are provided to both surfaces of a plastic film 2 and an image receiving layer 4 is provided to the surface of either one of the curable resin layers 3. The pencil hardness of the curable resin layers 3 is H or more in JIS-K5400. Since the plastic film 2 is arranged so as to be held between the curable resin layers 3 or the plastic film 2 is fixed on the single surface thereof, even if the plastic film 2 is softened by heat, the plastic film 2 itself can not be deformed and, therefore, the undulation phenomenon of a plate material as a whole can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a thermal transfer printer, PP.
A direct drawing type lithographic printing plate material suitable for plate making by a C copying machine and a printer using an electrophotographic method, and a lithographic printing plate using the same. More specifically, waviness of the entire plate material due to heat is reduced. The present invention relates to a direct drawing type lithographic printing plate material and a lithographic printing plate using the same.

[0002]

2. Description of the Related Art Currently, a lithographic printing plate used in the field of light printing is a direct drawing type in which a hydrophilicity-imparting layer is provided as an image receiving layer on a support, and an image receiving layer is provided on a conductive support. Examples include a wet electrophotographic type having a photoconductive layer, a silver salt photographic type using a silver halide emulsion diffusion transfer method, and a PS plate having a diazo photosensitive layer on a hydrophilic support. Among them, platemaking is easy. Direct drawing type lithographic printing plate materials are widely used in that they are carried out.

Such a direct drawing type planographic printing plate material is prepared by directly drawing on the image receiving layer with a thermal transfer printer, a PPC copying machine, a laser beam printer (a printer using an electrophotographic system) or the like. Aluminum plate, as a support that has been used in printing plates so far,
Paper, plastic film and the like are known.

However, the aluminum plate is expensive and has a difficulty in handling. Although paper is inexpensive, it has a problem in durability. Further, although the plastic film is durable, generally the temperature at which heat deformation starts is not so high. For example, even the most general-purpose polyester film has a temperature at which heat deformation starts at about 120 to 150 ° C. When heated above, the plastic film softens and undergoes thermal deformation. Therefore, when a plate material having a plastic film as a support is used to make a plate by, for example, a PPC copier, the fixing heat causes the plastic film to be thermally deformed, and the entire plate material is output in a very wavy state. . This phenomenon is particularly noticeable in models with a high fixing temperature such as a laser beam printer (hereinafter referred to as LBP) and models with a long fixing time, and the plate material is clogged in the conveyance path inside such a model. It even happened.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem and is for direct drawing type lithographic printing capable of remarkably reducing the corrugation phenomenon of the whole plate material due to heat. It is an object to provide a plate material and a planographic printing plate using the plate material.

[0006]

The direct drawing type planographic printing plate material of the present invention comprises:
It has a curable resin layer having a pencil hardness of H or more according to JIS-K5400, and an image receiving layer on the plastic film or the curable resin layer.

The curable resin layer is a layer formed of at least a photopolymerizable prepolymer, a photopolymerizable monomer and a photopolymerization initiator, and may further contain a matting agent.

The direct drawing type planographic printing plate material of the present invention will be described in detail below.

As shown in FIG. 1, the direct drawing type lithographic printing plate material of the present invention has a curable resin layer 3 on both surfaces of a plastic film 2, and one surface of the curable resin layer 3 is used. 1, which is provided with an image receiving layer 4 on its surface, as shown in FIG. 2, a plastic film 2 having a curable resin layer 3 and an image receiving layer 4 which are provided on one side of the plastic film 11 in sequence, as shown in FIG. , Which has the curable resin layer 3 on one surface of the plastic film 2 and the image receiving layer 4 on the other surface.

Any plastic film 2 can be used as long as it has a function as a support. For example, polyethylene terephthalate, polybutylene terephthalate, polycarbonate, polypropylene, polyethylene, acrylic, acetyl cellulose, vinyl chloride, fluorine. A film or sheet made of resin or the like can be used. Among them, the stretching processing, especially the biaxially stretching processing is preferable because the mechanical strength and the dimensional stability are improved. The thickness can be appropriately selected depending on the applied material, but in general, the range of 25 to 188 μm is preferable,
From the viewpoint of heat resistance and image density, those in the range of 50 to 125 μm are particularly preferable.

The curable resin layer 3 formed on one side or both sides of the plastic film 2 serves to hold and fix the plastic film and prevent deformation due to the influence of heat. It is related to reforming.

Generally, the temperature at which a plastic film begins to thermally deform is not so high. For example, even the most general-purpose polyester film has a temperature at which it begins to thermally deform at about 120 to 150 ° C., so that it is heated above this temperature. Then, it softens and causes thermal deformation, and cannot be used thereafter. This is particularly noticeable in a model such as LBP having a long fixing temperature and a long fixing time, and in such a model, a film jam (jamming) occurs in the transport path inside the machine.

Therefore, in the present invention, a curable resin layer made of a thermosetting or ionizing radiation curable resin is formed on one side or both sides of the plastic film to prevent such thermal deformation.

In order to obtain such performance, the hardness of the curable resin layer is H in terms of pencil hardness according to JIS-K5400.
Above, preferably 2H or more is necessary. The reason why it is set to H or higher is to suppress deformation of the plastic film due to heat.

Further, it is considered that the thermal deformation is also caused by the thickness of the curable resin layer, but it is difficult to determine it in general. Therefore, the thickness of the curable resin layer depends on the type and thickness of the plastic film 2 to be used and the curable resin layer 3.
Will depend on the type of resin used. That is,
When using a plastic film having a low temperature at which thermal deformation starts, or when the plastic film has a large thickness, the thickness of the curable resin layer must be increased. However, if a thick plastic film is used for a model with a relatively short fixing time, heat will not easily be transmitted to the inside of the plastic film and thermal deformation of the film will not easily occur, so even if the curable resin layer is relatively thin. It can be used. Although the thickness of the curable resin layer cannot be generally determined due to such circumstances, for example, in LBP in which thermal fixing is performed at about 200 ° C., the thickness of the curable resin layer is 1
It is about 30 μm, preferably about 3 to 10 μm.

Such a curable resin layer can be formed mainly from a coating material containing a thermosetting resin or an ionizing radiation curable resin. Above all, it is preferable to use an ionizing radiation curable resin from the viewpoints of work environment and productivity.

The ionizing radiation-curable resin is a resin which is cured by irradiation with electron beams or ultraviolet rays, and contains at least a photopolymerizable prepolymer, a photopolymerizable monomer and a photopolymerization initiator. Further, if necessary, a sensitizer, a non-reactive resin, an additive such as a leveling agent, and a solvent can be contained.

The structure, functionality and molecular weight of the photopolymerizable prepolymer are related to the curing of the ionizing radiation-curable resin and determine the properties such as adhesion, hardness and crack resistance of the ionizing radiation-curable resin. is there. The photopolymerizable prepolymer undergoes radical polymerization and / or cationic polymerization when the functional group introduced into the skeleton is irradiated with ionizing radiation. Those cured by radical polymerization are particularly preferred because they have a high curing rate and a high degree of freedom in resin design.

As the photopolymerizable prepolymer, an acrylic prepolymer having an acryloyl group is particularly preferable, which has two or more acryloyl groups in one molecule and has a three-dimensional network structure. As the acrylic prepolymer, urethane acrylate, epoxy acrylate, melamine acrylate, polyester acrylate and the like can be used.

The photopolymerizable monomer is used for diluting the highly viscous photopolymerizable prepolymer to reduce the viscosity and improve workability, and as a cross-linking agent to impart coating strength. .

As the photopolymerizable monomer, monofunctional acrylic monomers such as 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate and butoxyethyl acrylate, 1,6
-Bifunctional acrylic monomers such as hexadiol acrylate, neopentyl glycol diacrylate, hydroxypivalic acid ester neopentyl glycol acrylate, dipentaerythritol hexaacrylate,
One or more of polyfunctional acrylic monomers such as trimethylpropane triacrylate and pentaerythritol triacrylate are used.

Further, since the coating film becomes harder than necessary when the amount of the photopolymerizable monomer mixed is increased, a thermosetting resin, a thermoplastic acrylic resin, an epoxy resin or an epoxy resin is used so as to obtain a desired hardness or a desired flexibility. The hardness can be adjusted by appropriately mixing a non-reactive resin such as a resin. The mixing ratio may be appropriately selected.

The photopolymerization initiator is added in order to start the reaction of the acryloyl group by irradiation of ionizing radiation in a short time and accelerate the reaction, and has a catalytic action. The photopolymerization initiator is required particularly when curing is performed by ultraviolet irradiation, and may not be required when irradiating a high energy electron beam. As the kind of the photopolymerization initiator, there are radical polymerization by cleavage, radical polymerization by abstracting hydrogen, and cationic polymerization by generating ions.

The photopolymerization initiator can be appropriately selected.
For example, benzoin ether type, ketal type, acetophenone type, thioxanthone type radical photopolymerization initiators, diazonium salts, diaryliodonium salts, triarylsulfonium salts, triarylpyrylium salts,
Examples thereof include benzylpyridinium thiocyanate, dialkylphenacylsulfonium salt, dialkylhydroxyphenylsulfonium salt, dialkylhydroxyphenylphosphonium salt, and complex cationic photopolymerization initiators, and one or more of these can be used. The photopolymerization initiator is used in a mixture of 2 to 10% by weight, preferably 3 to 6% by weight, based on the resin solid content.

The curable resin layer preferably contains a matting agent in order to improve the adhesion to the image receiving layer described later.

As the matting agent, inorganic particles such as silica, clay, alumina, calcium carbonate and barium sulfate, acrylic resin particles, silicone resin particles, nylon resin particles, styrene resin particles, polyethylene resin particles, benzoguanamine resin particles, urethane resin Organic particles such as particles can be used.

The matting agent is added in an amount of 10 to 10% of the resin solid content.
It is in the range of 200% by weight, preferably 30 to 100% by weight. If it is less than 10% by weight, the effect of addition cannot be obtained, and if it exceeds 200% by weight, the hardness of the curable resin layer becomes weak and it becomes difficult to sandwich the plastic film.

To cure the ionizing radiation curable resin,
Irradiate with electron beam or ultraviolet ray. When irradiating an electron beam, use a scanning or curtain type electron beam accelerator,
Acceleration voltage 1000 keV or less, preferably 100-30
It can be performed by irradiating with an electron beam having an energy of 0 keV and a wavelength region of 100 nm or less.

When irradiating with ultraviolet rays, an ultrahigh pressure mercury lamp, a high pressure mercury lamp, a low pressure mercury lamp, a carbon arc, a metal halide lamp or the like is used, and the wavelength is 100 to 400 nm, preferably 2 nm.
50 to 300 kcal in the wavelength region of 00 to 400 nm
Irradiate with ultraviolet light having an energy of / mol.

When the curable resin layer is cured by irradiating it with an electron beam or an ultraviolet ray, the presence of oxygen and the thickness of the coating film are closely related to the curing. Radicals generated by irradiation with ionizing radiation supplement oxygen, thereby suppressing curing.
Therefore, when the thickness of the coating film is thin, the surface area occupied by the coating film volume is large, and the oxygen in the air is likely to impede curing. Further, when the coating film is thick, ionizing radiation does not easily penetrate to the inside, and even if the surface is cured, internal curing is not sufficient and the uncured portion of the coating interface exists, so that the curing resin layer and Poor adhesion of the plastic film will occur. In order to prevent such curing inhibition and uncuring, particularly in the case of electron beam irradiation, irradiation can be performed under an inert gas such as N ₂ gas. Further, it is possible to prevent curing inhibition by adjusting the thickness of the coating film, selecting a photopolymerizable prepolymer or a photopolymerizable monomer having a fast curing rate, and increasing the mixing amount of the photopolymerization initiator.

On the plastic film 2 or the curable resin layer 3 on the side opposite to the image receiving layer side, which will be described later,
A curl-preventing layer (not shown) formed of nitrocellulose or the like, which has a role of holding the plate material smooth, or an ionizing radiation curable resin, etc., and a function of curling the plate material on the side opposite to the image receiving layer surface. It may be provided with a curl promoting layer (not shown). It is preferable to provide such a curl preventing layer or a curl promoting layer because the workability of attaching to the plate cylinder at the time of offset printing after preparing the printing plate is improved.

Further, an image receiving layer 4 as a hydrophilicity-imparting layer is formed on the curable resin layer 3 or the plastic film 2.

The image receiving layer 4 can be composed of at least a hydrophilicity-imparting agent such as zinc oxide, titanium oxide, clay and alumina silicate and a polymer binder. However, it is preferable to form the image-receiving layer via a conductive layer for adjusting the surface resistance value on the image-receiving layer, because bleeding of the toner image can be prevented.

The direct drawing type planographic printing plate material of the present invention is coated with a curable resin layer coating material on one or both sides of a plastic film by a conventional coating method such as bar, blade, gravure, spin or spray coating. Can be applied by irradiating with an electron beam or an ultraviolet ray to form a curable resin layer, and the coating solution for an image receiving layer can be applied and formed on one surface by a similar coating method.

When a conductive layer is formed, a conductive layer coating solution is applied and formed on one side of a plastic film having the curable resin layer on one side or both sides by the same coating method as described above, and It can be prepared by applying the above-mentioned coating liquid for the image receiving layer on the above by a similar coating method.

The direct drawing type planographic printing plate material having such a structure has almost no waviness even when a toner image is formed by a PPC copying machine or LBP. It is considered that this heat wave phenomenon is suppressed because the temperature at which the curable resin layer begins to thermally deform is high and the hardness is high. That is, because the plastic film is placed so that a specific curable resin layer is sandwiched between them, or because the plastic film is fixed on one side, the plastic film itself deforms even if the plastic film softens due to heat. Because you cannot do it. It is also considered that this structure makes it difficult for heat to be conducted to the plastic film, which also acts to suppress this phenomenon.

In addition, an adhesive layer or the like may be interposed between the respective layers as required, or a plastic film may be subjected to an easy-adhesion treatment.

[0038]

In the plate material for direct drawing type lithographic printing of the present invention, since the specific curable resin layer is provided, the corrugation phenomenon of the entire plate material can be remarkably reduced even if the plastic film is heated. Therefore, a lithographic printing plate without thermal deformation can be obtained.

[0039]

EXAMPLES Examples of the present invention will be shown below.

Example 1 A curable resin layer coating composition having the following composition was prepared on both sides of a 100 μm-thick polyester film having both sides subjected to easy adhesion treatment, and applied by a bar coating method, followed by high pressure. A curable resin layer having a thickness of 7.0 μm and a pencil hardness of 2H according to JIS-K5400 was provided by irradiating ultraviolet rays with a mercury lamp for 1 to 2 seconds.

Composition of curable resin layer coating composition (solid content: 23
%) ・ UV-curable acrylic resin 13.0 parts by weight (UniDic 17-806: Dainippon Ink and Chemicals, Inc.) ・ Photopolymerization initiator 0.3 parts by weight (IrgaCure 651: Ciba Geigy) ・ Silica 4.5 parts by weight Parts (Sylysia 445: Fuji Silysia Chemical Ltd.)-Silica 0.8 parts by weight (Aerosil R-202: Nippon Aerosil Co., Ltd.)-Methyl ethyl ketone 18.0 parts-Toluol 23.0 parts-Butyl acetate 10.0 parts

Further, the following coating solution for image receiving layer was applied by bar coating on one surface of the polyester film on which the curable resin layer was formed and dried at 150 ° C. for 60 seconds to obtain an image receiving layer having a thickness of 7 μm. A direct drawing type planographic printing plate material having

"Coating liquid for image receiving layer" -Conductive zinc oxide 45 parts by weight (SAZEX # 2000: Sakai Chemical Co., Ltd.)-Acrylic resin (solid content 50%) 14 parts by weight (Acridic 167: Dainippon Ink and Chemicals)・ Synthetic silica (average particle size 7 μm) 2 parts by weight (Sylysia 770: Fuji Silysia Chemical Ltd.) ・ Toluol 45 parts by weight [Example 2] 100 μm in thickness with easy adhesion treatment on both sides
A curable resin layer similar to that in Example 1 was provided on one surface of the polyester film of m.

Further, Example 1 was formed on the curable resin layer.
An image receiving layer similar to the above was provided to obtain a direct drawing type planographic printing plate material.

Example 3 A curable resin layer similar to that of Example 1 was provided on one surface of a 100 μm-thick polyester film having both surfaces subjected to easy adhesion treatment.

Further, an image receiving layer similar to that of Example 1 was provided on the opposite surface of the polyester film having the curable resin layer formed thereon, to obtain a direct drawing type planographic printing plate material.

Comparative Example An image receiving layer similar to that of Example 1 was formed on a polyester film having a thickness of 100 μm,
A direct drawing type planographic printing plate material was obtained.

LBP (fixing temperature about 180 ° C. TN7270) was applied on the direct drawing type planographic printing plates of Examples 1 to 3 and Comparative Example.
PS1: Toshiba Corp.) was used to output a toner image to obtain a lithographic printing plate. As a result, in the example product, no waviness was observed at all as in the case before the output, but in the comparative example product, the plate material was clogged during the output in the conveying path after the toner fixing portion in the printer. For this reason, when 5 cm of carrier paper was adhered to the leading end of the material and output was performed, the output was output without causing clogging of the plate material.
Many waviness with a height of mm or more was generated.

As is clear from this result, it was confirmed that the product of Example did not cause the corrugation phenomenon due to heat and could prevent the deterioration of the flatness due to heat.

[0050]

EFFECT OF THE INVENTION Since the plate material for direct drawing type lithographic printing plate of the present invention is provided with a specific curable resin layer on the plate material having a plastic film as a support, thermal deformation of the plastic film as a support starts. Even if the plate material is heated to a temperature higher than the temperature, the wavy phenomenon of the entire plate material hardly occurs, and good flatness can be maintained.

Further, according to the direct drawing type planographic printing plate material of the present invention, it is possible to obtain a planographic printing plate which is free from thermal deformation.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a sectional view showing an embodiment of the present invention.

FIG. 3 is a sectional view showing one embodiment of the present invention.

[Explanation of symbols]

 1, 11, 12 ... Plate material for direct drawing lithographic printing 2 ... Plastic film 3 ... Curable resin layer 4 ... Image receiving layer

Claims (4)

[Claims] 1. A plastic film having a curable resin layer having a pencil hardness of H or more according to JIS-K5400 on at least one side, and an image receiving layer on the plastic film or the curable resin layer. Direct drawing type lithographic printing plate material. 2. The direct drawing type lithographic printing according to claim 1, wherein the curable resin layer is a layer formed by at least a photopolymerizable prepolymer, a photopolymerizable monomer and a photopolymerization initiator. Plate material. 3. The direct-drawing type lithographic printing plate material according to claim 1, wherein the curable resin layer contains a matting agent. 4. A lithographic printing plate having a toner image on the image receiving layer of the lithographic printing plate material of claim 1.