JPH01192555A - Dry lithography manufacturing method and lithographic materials - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Applicability] The present invention relates to dry lithography, and more particularly to a dry lithographic plate making method and a lithographic material that can be used in this method.

[Conventional technology]

The lithographic printing method is generally popular as the offset printing method. In the normal offset printing method, an oleophilic area and an oleophilic area are formed on the printing surface, and water called dampening water is applied to the hydrophilic area to repel oil-based ink and prevent it from adhering. The ink is applied to the paper, transferred once to the blanket, and then transferred again to the printing material for printing.

With the above printing method, the dampening water management technology is difficult, so
Offset printing methods that do not use dampening water, ie, dry lithographic printing methods, have been developed. This method has many advantages because no dampening solution is used.

A printing plate for dry lithography basically has an oil-repellent portion and a lipophilic portion, and ink adheres only to the lipophilic portion and does not adhere to the oil-repellent portion. This oil-repellent part is generally made of an organic silicone compound or an organic fluorine compound, and a printing plate is manufactured by removing a part of the oil-repellent part by appropriate means to expose the lipophilic part and form an ink receiving part. . As a method to remove the oil-repellent part,
Photochemical means are common. For example, by imparting photosensitivity to the oil-repellent layer and photocuring the exposed portion to form an oil-repellent portion,
On the other hand, there is a method in which the unexposed area is developed and removed using a solvent or the like to form a lipophilic area. In addition, oil repellent layer (silicone rubber layer)
A general photosensitive resin layer such as a diazonium compound is placed on the bottom of the photosensitive resin layer, the exposed areas are cured and preserved, and when the unexposed areas are developed and removed, the oil-repellent area of the upper layer is also removed to expose the lipophilic area. There are also methods. Furthermore, various methods have been proposed for simple printing plates, such as a method of attaching toner using electrophotography, although these methods have not been put to practical use.

Furthermore, a method has also been proposed (Japanese Patent Publication No. 42-21879) in which a silicone layer coated on the entire surface is locally destroyed to expose the substrate surface, and ink is applied to the exposed portion.

[Problems to be Solved by the Invention] The method for producing a printing plate for dry lithography using photochemical means as described above has high resolution and sharpness of image lines in the ink receiving area, and it is possible to obtain high-quality printed matter. However, there is a problem in that the plate-making process requires complicated and expensive equipment and a long plate-making time.

The manufacturing method of dry lithography plates for simple printing plates, which applies electrophotography, is a simple, inexpensive, and quick plate-making method, but it requires an oil-repellent substance to be attached to other substances.
Since this oil-repellent substance essentially has poor affinity with other substances, the toner adhesion (fixation) of the oil-repellent substance is poor.
It is unstable and has poor printing durability.

Further 5. Even the method of locally destroying the silicone layer has the problem of requiring complicated and expensive equipment and plate making time using electron beam or laser beam irradiation, discharge destruction, etc.

The present invention has been made based on the above-mentioned background, and its purpose is to provide a dry lithographic plate that can produce high-quality printed matter with high-resolution and sharp lines in the ink-receiving area. An object of the present invention is to provide a method for manufacturing printing plates simply, inexpensively, and quickly, and a lithographic material that can be used in this method.

[Means to solve the problem]

The above-mentioned problems are solved by the method for producing a dry lithographic plate of the present invention and the lithographic material used therein.

That is, in the method for producing a dry lithographic plate according to the present invention, at least a support, a lipophilic heat-softening material layer, and an oil-repellent material layer are laminated, and a foaming agent is applied to the lipophilic heat-softening material layer and/or the oil-repellent material layer in advance. A heat signal corresponding to the image symbol information is sent to the lithographic material containing the lithographic material, and the heat-softening material layer portion and the corresponding oil-repellent material layer portion of the lithographic material receiving the heat signal are physically and/or chemically It is characterized by forming a lipophilic portion corresponding to the image symbol information on the surface of the planographic material by changing it, that is, by thermal softening and foaming.

In a preferred embodiment of the invention, the thermal signal is transmitted by a thermal recording head having an electrical heating element or by irradiation with energy beams.

The lithographic material of the present invention is a material in which at least a support, a lipophilic heat-softening material layer, and an oil-repellent material layer are laminated, and a foaming agent is blended in the lipophilic heat-softening material layer and/or the oil-repellent material layer. , the heat-softening material layer portion and the corresponding oleophobic material layer portion of the planographic material that received the thermal signal are physically and/or chemically changed to form a lipophilic portion corresponding to the image symbol information on the surface of the planographic material. It is characterized by forming.

In a preferred embodiment of this invention, a heat-resistant film can be easily peeled and laminated on the surface of the oil-repellent material layer.

The invention will be explained in more detail below.

Lithographic Material The lithographic material of the present invention is a material comprising at least a support, a lipophilic heat-softening material layer, and an oil-repellent material layer.

The support that can be used in this invention is a substrate of a plate-making material and has mechanical strength. Examples of such materials include light metals such as aluminum, other metals such as iron and copper, alloys thereof, plastic films such as polyester and polystyrene, paper, cloth, wood, and composite materials thereof. The shape, dimensions, etc. of this support can be selected as appropriate.

The lipophilic heat-softening substance layer used in this invention has a lipophilic (
(Also referred to as ink affinity) and heat softening property (in this specification, heat softening property is a concept that includes heat melting property)
It is a substance that has Specifically, at 40 to 180°C,
Preferably, it is an organic substance that easily softens or melts at 50 to 130°C, such as thermoplastic synthetic resins, natural resins, and waxes, such as spermaceti wax, carnauba wax, and candelilla. Natural waxes such as wax, wood wax, beeswax, montan wax, lanolin wax, paraffin wax, microcrystalline wax, ester wax, oxidized wax, low molecular weight polyethylene wax, synthetic waxes such as chlorinated paraffin, lauric acid, myristic acid, valmitic acid, stearin acids, higher fatty acids such as fromenic acid and behenic acid, higher alcohols such as stearyl alcohol and behenic alcohol, esters such as sucrose fatty acid esters and surbitan fatty acid esters, amides such as stearinamide and oleinamide, and polyamides. Vinyl resins such as vinyl chloride, polyvinylidene chloride, polystyrene, polyvinyl acetate, vinyl chloride-polyvinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-methacrylic acid, ethylene-vinyl acetate copolymer, styrene -Butadiene-
Copolymers such as acrylonitrile copolymer ethylene-α-olefin copolymer elastomer, saponified ethylene-vinyl acetate copolymer, cellulose resins such as ethyl cellulose and cellulose acetate, polyethylene, polypropylene, acid-modified polyolefin, polyamide, polycarbonate , thermoplastic resins such as polysulfone, polyacetal, polymethyl methacrylate, polyphenylene oxide, polyurethane, polyethylene terephthalate, polybutadiene terephthalate, rubbers such as synthetic rubber, chlorinated rubber, natural rubber, etc., epoxy resins, polyurethane resins, Acrylic resin, petroleum resin,
Examples include phenolic resins, polyethylene waxes, montan waxes, partially saponified ester waxes, fischatrobusch waxes, and oil-based waxes.

This heat softening layer may contain a heat transfer material such as graphite, carbon, metal powder, or a light absorbing material in order to improve heat sensitivity.

In the lithographic material of the present invention, the lipophilic heat-softening layer is laminated directly or indirectly on the support, and the layer thickness is 1
~20 μm, preferably 2 to 10 μm, and can be formed by adhering or coating uniformly or non-uniformly and drying.

In the lithographic material of the present invention, the oleophobic substance layer is directly or indirectly laminated on the oleophilic heat-softening layer to form an ink-repellent portion on the lithographic plate. This oil-repellent substance has a small critical surface tension γ (dyne/as), such as polyhexafluoropropylene, polytetrafluoroethylene, polydimethylsiloxane, polytrifluoroethylene, polyvinyl fluoride, polytrifluoroethylene, etc. There are fluorine-based resins such as chlorethylene and silicone-based resins. In addition, materials already used as oil-repellent substances in dryography, such as the silicone rubber resins mentioned above, various silicone resins such as photosensitive silicone resins into which photosensitive groups have been introduced, and fluorine-based resins can also be reused. You can also do that.

In the planographic material of this invention, the layer thickness of the oil-repellent material layer is:
The thinner the thickness, the higher the thermal sensitivity and resolution, but the lower the printing durability, so it can be selected as appropriate depending on the purpose.
The thickness is 0 μm, preferably 1 to 5 μm, and can be formed by adhering or coating uniformly or non-uniformly and drying.

In this invention, a blowing agent is kneaded and blended into the lipophilic heat-softening material layer and/or the oil-repellent material layer. An example of this blowing agent is dinitrosopentamethylenetetramine (1
90-205°C, abbreviation DPT), N,N'-dimethyl-N,N'-dinitrosoterephthalamide (105
°C), penzenesulfonyl hydrazide (90-95 °C,
Abbreviation BSH), p-toluenesulfonyl hydrazide (
110°C, abbreviation TSH),) luene-2,4-disulfonylhydrazide (150°C), p-toluenesulfonylhydraxine (135°C), toluene-2,4-disulfonylhydraxine (145°C), 4. 4'-oxybis(benzenesulfonyl hydrazide (140-16
0℃), azobisisobutyronitrile (100-115
°C), azodicarbonamide (175-200 °C, abbreviation AZC), diazoaminobenzene (97-103 °C,
In addition to these, there are foaming auxiliaries that lower the foaming temperature, such as urea-based auxiliaries, and organic acid-based auxiliaries such as salicylic acid, phthalic anhydride, stearic acid, and lauric acid. .

The amount of the above-mentioned blowing agent can be selected and changed as appropriate depending on the use, purpose, and type.

Embodiments of the lithographic material of the present invention will be explained with reference to the drawings.

FIG. 1 shows a cross-sectional view of an example of one embodiment of a lithographic material.

In the planographic material 1 of this embodiment, a thermally softened layer 3 is formed on the support 4, and an oil-repellent layer 2 is further laminated thereon. Variations are possible. For example, as shown in FIG. 2, in addition to the support 4, the heat-softening layer 3, and the oil-repellent layer 2, a slipping film 5 and a protective layer 6 can be laminated on the surface of the oil-repellent layer 2. The sliding film 5 of this embodiment can ensure slippage with the head when a thermal head is used to send out thermal signals, and the protective layer 6 can ensure slippage with the thermal head when the sliding film 5 with poor heat resistance is used. Contributes to imparting heat resistance and slipperiness.

The layer thickness of the sliding film may be, for example, 1 to 10 μm. The layer thickness of the protective layer 6 may be, for example, 1 to 2 μm.

Examples of materials for the above-mentioned slip film and protective layer include polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, polystyrene, ethylene-acrylic acid copolymer, ethylene-methacrylic acid, ethylene-vinyl acetate copolymer, ethylene- Saponified vinyl acetate copolymer, ethylene-α-olefin copolymer elastomer,
acid-modified polyolefin, styrene-butadiene-acrylonitrile copolymer, polyamide, polycarbonate,
Polysulfone, polyacetal, polymethyl methacrylate, polyphenylene oxide, polyurethane, polyethylene terephthalate, polybutadiene terephthalate, nylon, polyimide and other plastics, paper such as capacitor paper, cloth, nonwoven fabrics, and these alone or in combination (coextrusion) films, etc.), composites, and laminates.

If the above-mentioned film lacks heat resistance or slippage is unsatisfactory, a heat-resistant slip agent having a thickness of 1 to 2 μm may be applied to the film. This layer can contain a three-dimensional structure heat-resistant resin such as acrylic resin, and a slip agent such as microsilica.

Method for manufacturing dry lithography The method for manufacturing dry lithography of the present invention involves transmitting a thermal signal corresponding to image symbol information to the lithographic material detailed above, and detecting the heat-softening substance layer portion of the lithographic material that received the thermal signal and the corresponding portion of the lithographic material. By physically or/chemically changing the oil-repellent material layer,
That is, the oil-repellent layer is destroyed or removed by thermal softening or thermal melting of a thermally softening substance, and foaming of a foaming agent, or
The method includes roughening the surface of the oil-repellent layer to form a lipophilic portion corresponding to image symbol information on the surface of the planographic material.

In this invention, the transmission of the thermal signal corresponding to the image symbol information is carried out from the oil-repellent layer side or the support side using a suitable device.

In this invention, the thermal signal can be transmitted by a thermal recording head (thermal head) having an electric heating element or by irradiation with energy rays.

When a thermal recording head is used, the heating element of the thermal head is brought into contact with the oil-repellent layer in the embodiment shown in FIG. 1, or with the protective layer in the embodiment shown in FIG. It can also send out heat signals.

In this case, the thermal signal can be sent using a thermal head in an output device such as a normal personal computer, facsimile, or word processor.

On the other hand, the thermal signal can be transmitted by irradiating energy rays such as infrared rays, ultraviolet rays, visible light, X-rays, and electron beams. This energy ray irradiation can be carried out, for example, by overlaying a mask plate such as a halftone photographic original plate or a metal original plate on the oil-repellent layer surface of the lithographic material and irradiating the entire surface with the energy rays. It can be performed by focusing a laser beam, a He-Cd laser beam, etc. narrowly and repeatedly turning ON-OFF scanning. That is, an appropriate image may be used as a light-shielding mask to perform flash exposure, and further drawing may be performed using a high-power laser beam.

Next, an embodiment of the method for producing a dry lithographic plate according to the present invention will be described.
This will be explained in detail using the accompanying drawings. FIG. 3 is a sectional view showing each step of the embodiment.

In this embodiment, a planographic material 1 consisting of a support 4, a thermally softened layer 3, and an oil-repellent layer 2 is prepared, and a thermal head 7 is brought into contact with or close to the surface of the oil-repellent layer 2, and image symbol information is processed from this head 7. The thermally softened layer is thermally melted and foamed via the oil-repellent layer 2 (FIG. 3A). the result,
Due to the change in the heat-softened layer, the corresponding part of the oil-repellent layer 2 above it is destroyed, the lipophilic part of the heat-softened layer is exposed, and the surface is roughened to form the ink receiving part 8, and the remaining oil-repellent layer becomes ink repulsion #9 (Figure 3B).

FIG. 3C shows another aspect of the change. In this embodiment, the oil-repellent layer is relatively thick or has good film properties, and in this case, the surface of the corresponding portion of the oil-repellent layer is roughened.

The method for producing a dry lithographic plate according to the present invention is not limited to the above example, and various modifications are possible. For example, as shown in FIG. 4, a mask plate such as a dotted photographic original plate or a metal original plate, that is, a transparent original plate 10 is used as an oil-repellent layer of a planographic material 1 consisting of a support 4, a heat-softening layer 3, and an oil-repellent layer 2. By superimposing it on the surface of 2 and applying xenon flash or infrared exposure 11,
A thermal signal is sent out to physically and/or chemically change the thermally softened layer via the oil-repellent layer 2 (FIG. 4A).

As a result, due to changes in the thermally softened layer, the oil repellent layer 2 on top of it changes.
The corresponding part of the heat-softening layer is destroyed, the lipophilic part of the heat-softening layer is exposed and its surface is roughened, and the ink-receiving part 8 is formed, and the remaining oil-repellent layer becomes the ink-repelling part 9 (Fig. 4). B)
.

Note that when a protective film or the like is laminated on the oil-repellent layer, this protective film is peeled off after recording.

The obtained dry lithography plate can be used as an original plate in a normal dry lithography method.

[For production]

This invention configured as described above operates as follows.

For example, when a thermal head is brought into contact with or in close proximity to the surface of the oil-repellent layer of the lithographic material and a signal corresponding to image symbol information is sent from this head, heat reaches the thermally softened layer through the oil-repellent layer, and this heat The softened layer part softens or melts,
It also deforms due to the contact pressure of the head. Moreover, since the foaming agent is blended in the lipophilic heat-softening material layer and/or the oil-repellent material layer, the foaming agent is decomposed by heat, causing the heat-softening material layer and/or the oil-repellent material layer to foam. As a result, the corresponding portion of the oil-repellent layer supported by the heat-softened layer is destroyed, the lipophilic portion of the heat-softened layer is exposed, and its surface is roughened. In some cases, the oil-repellent layer remains, but the corresponding portions of the oil-repellent layer are locally foamed and roughened, and the rough surface portions exhibit ink receptivity. In this way, an ink receiving part is formed, and the remaining oil-repellent layer becomes an ink repelling part. This pattern corresponds to the transmitted image symbol information, and the obtained dry planographic plate can be used to perform dry planographic printing.

In addition, when transmitting a thermal signal by irradiating energy rays such as infrared rays, ultraviolet rays, visible light, X-rays, and electron beams, when the oil-repellent layer is transparent, it directly reaches the heat-softening layer and undergoes light/thermal conversion. Then, the heat-softened layer portion softens or melts and foams in the same manner as described above. In addition, if the oil-repellent layer is not transparent, the oil-repellent layer may be exposed to light.
Through heat conversion, the heat-softened layer portion softens or melts and foams in the same manner as described above.

〔Effect of the invention〕

The following effects can be obtained by this invention.

Judging from the above structure and operation, and as demonstrated by the following examples, a dry lithographic printing plate that can produce high-quality printed matter with image lines in the ink receiving area having good resolution and sharpness. A version can be manufactured easily, inexpensively, and quickly using an existing word processor or the like.

〔Example〕

This invention will be specifically explained by the following examples.

Example 1 A heat-sensitive melting layer (melting temperature: 70 to 100°C) having the following composition was applied to a thickness of 5 μm on a polyester film having a thickness of 0.2i+m.

Heat-sensitive melting layer composition Ethylene-vinyl acetate copolymer (manufactured by Sumitomo Chemical)...9
g Carnauba wax (manufactured by Kato Yoko) ...38g Barafil 155F (manufactured by Nippon Seiro) ...38g carbon black ...10g4.4
′-oxybis(benzenesulfonyl hydrazide
...5g Silicone rubber was then applied to a thickness of 1 to 3 μm and dried to prepare a lithographic material.

16 dots/ma+ on the silicone surface of the obtained lithographic material
When characters from a word processor were printed using a thermal recording head (a commercially available thermal recording printer), the silicone rubber surface was destroyed and the wax layer was exposed.

The obtained lithographic printing plate is set on a light offset printing machine,
Printing was performed using a commercially available dryography ink.

The obtained printed matter had good resolution and sharpness.

Example 2 A photographic film with black and white letters was brought into close contact with the silicone surface of the lithographic material used in Example 1, and the film was successively irradiated several times with an IKW xenon flash. Next, when this photographic film was peeled off, the silicone rubber surface portion corresponding to the transparent portion was destroyed, and a lithographic printing plate was obtained.

The obtained lithographic printing plate is set on a light offset printing machine,
Printing was performed using a commercially available ink for dryography.

The obtained printed matter had good resolution and clarity.

Example 3 A thin polyester film of 3 μm was uniformly stretched on the silicone surface of the lithographic material used in Example 1.
It was squeezed and crimped at 0°C. When characters from a word processor were printed on the film surface using a thermal recording head (a commercially available thermal recording printer), the thermal recording head ran extremely smoothly and stable recording operations were possible. When the polyester film was peeled off after recording, the silicone rubber surface was destroyed and the wax layer was exposed. Since the polyester film was thin, the resolution of recording was not impaired.

The obtained lithographic printing plate is set on a light offset printing machine,
Printing was performed using a commercially available dryography ink.

The resulting printed matter had good resolution and sharpness.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an example of a planographic material according to the present invention, and FIG.
The figure is a cross-sectional view showing another example of a planographic material, FIG. 3 is a cross-sectional view showing each step of one embodiment of the manufacturing method of the present invention, and FIG. 4 is a cross-sectional view showing each step of another embodiment of the manufacturing method of the present invention. FIG. DESCRIPTION OF SYMBOLS 1... Lithographic material, 2... Oil-repellent layer, 3... Heat softening layer, 4... Support, 5... Sliding film, 6... Protective layer, 7... Thermal head, 8... Ink receiving part, 9... Ink repelling part, 1G... Transparent original plate, 11...
··flash. Applicant's agent Mr. Sato

Claims (1)

[Scope of Claims] 1. A lithographic plate in which at least a support, a lipophilic heat-softening material layer, and an oil-repellent material layer are laminated, and a foaming agent is blended in the lipophilic heat-softening material layer and/or the oil-repellent material layer. In the material,
Sending out a thermal signal corresponding to the image symbol information and physically and/or chemically changing the heat-softening material layer portion and the corresponding oil-repellent material layer portion of the planographic material that received the thermal signal,
A method for producing a dry lithographic plate, characterized in that a lipophilic portion corresponding to image symbol information is formed on the surface of a lithographic material. 2. A material in which at least a support, a lipophilic heat-softening material layer and an oil-repellent material layer are laminated, and a foaming agent is blended in the lipophilic heat-softening material layer and/or the oil-repellent material layer. lithographic material.