JPH0723031B2 - Thermal plate making method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention provides at least a metal vapor-deposited layer on a lipophilic support comprising an ink-sensitive layer, and a protective thin film layer on the metal vapor-deposited layer. The present invention relates to a plate-making method using a lithographic printing plate precursor for heat-sensitive plate making, and the purpose thereof is to enable direct plate-making by a simple method using a heat mode recording method, which is clear even with an offset printing machine. It is to provide a printing original plate on which an image can be obtained.

(Prior Art) Conventional lithographic printing plates include PS plates using a photosensitizer and lithographic printing plates for electrophotography using zinc oxide.
However, making these printing plates is not easy and requires special equipment. For example, in the SP plate, it is not possible to print a pattern directly from the original onto the printing plate, and it is necessary to use a photo master plate in the middle. The process of processing this photographic master is complicated, and the chemicals used are often dangerous and may cause contamination. Further, in producing a printing master from a lithographic printing plate for electrophotography, as is well known, the configuration of the stencil plate is such that a vapor-deposited conductive layer of aluminum, chromium, nickel or the like is provided on the upper surface of the lipophilic support, and the upper surface thereof is provided. Although it has a structure in which a semi-conductive layer made of a semi-conductive substance and an adhesive is provided, there is a drawback in that various steps such as exposure, development, and fixing are involved and the apparatus becomes bulky.

(Problems to be Solved by the Invention) The present invention relates to a heat-sensitive material comprising at least three layers in which a metal vapor deposition layer is provided on a lipophilic support comprising an ink oil-sensitive layer, and a protective thin film layer is further provided thereon. The present invention relates to a plate making method, and an object thereof is to a printing original plate capable of obtaining a clear image by an offset printing machine capable of direct plate making by a simple method using a heat mode recording method. The ink-sensitive layer that constitutes the printing plate precursor contains a pigment having an average particle of 1 to 10 μm, a center line average roughness of 0.5 to 1.5 μm, and a melting point of 500 ° C. in a hydrophilic metal vapor deposition layer. The present invention relates to a plate making method for a printing original plate, which is characterized by using the following metals.

(Means for Solving Problems) The lithographic printing plate precursor for heat-sensitive plate making according to the present invention may or may not use a support, but at least metal vapor deposition on the ink oil-sensitive layer. A laminated body having a layer and a protective thin film layer provided thereon, wherein an image is formed by removing the hydrophilic layer portion composed of the protective thin film layer and the metal vapor deposition layer by heat sensitivity. In particular, the ink-sensitive layer contains a pigment having an average particle size of 1 to 10 μm and a center line average roughness of 0.1 to 1.5.
There is provided a heat-sensitive plate making method characterized by having a thickness of μm.

FIG. 1 is a schematic sectional view of a plate-making material used in the present invention. In FIG. 1, an ink oil-sensitive layer 2, a metal vapor deposition layer 3, and a protective thin film layer 4 are sequentially laminated on a support 1. Each layer will be specifically described below.

The support 1 is used as a printing plate, and any one can be used as long as it is mechanically tough and flexible, but it is not essential in the present invention, and the ink-sensitive layer 2 is The separate support 1 can be omitted as long as it has physical properties.

Specific examples of the support 1 include plastic films or sheets of polyethylene terephthalate, polypropylene, polyester, polycarbonate, etc., coated paper, art paper, laminated paper, resin-impregnated paper, and metal plates such as aluminum and zinc. Moreover, what combined those materials suitably is also used.

The ink oil-sensitive layer 2 is a layer in which an image appears by imagewise heating, and the composition thereof is ethyl cellulose, hydroxyethyl cellulose, cellulose acetate propionate, cellulose derivative such as cellulose acetate, polystyrene, poly-α-methylstyrene, or the like. Styrene resin or styrene copolymer resin, homopolymer or copolymer resin of acrylic acid resin or methacrylic acid resin such as polyethyl methacrylate, polybutyl methacrylate, rosin, rosin modified maleic acid resin, rosin ester resin such as polymerized rosin It is a binder of various resins such as polyvinyl acetate, polyvinyl chloride, polyester, polyurethane, and polybutyral resin in which a pigment having an average particle size in the range of 1 to 10 μm, preferably 5 μm or less is present. Appropriate unevenness on the layer Ri, the center line average roughness of 0.5
It is preferably in the range of to 1.5 μm. The center line average roughness of the ink-sensitive layer 2 is in the range of 0.5 to 1.5 μm.
If it is 0.5 μm or less, the adhesion with the metal vapor deposition layer 3 is poor,
Further, when the thickness is 1.5 μm or more, it is easy to obtain a printed matter having a poor gradation property of the formed image. The unevenness of the coated surface is reflected on the metal vapor deposition layer 3 to increase the diffuse reflection of light and reduce the gloss, so that the image formed by the heat mode recording method is easy to see and the adhesion with the metal vapor deposition layer is improved. Become stronger. In offset printing, it also serves as a water retaining surface for dampening water, which has a water retaining effect.

As the pigment, zinc oxide, titanium oxide, calcium carbonate, silica, clay, carbon black, inorganic pigments such as activated clay, crosslinked polystyrene, polystyrene beads, organic transparent or white pigments such as silicon beads,
Colored pigments such as lead white, ultramarine blue, titanium yellow, and reddish yellow lead, organic pigments such as permanent orange GTR, brilliant scarlet G, permanent red F5R, green gold, and rhodamine chelate are used. If added, the hydrophilic layer is destroyed and removed by heating so that a positive image can be exposed on the original plate.

Further, a plasticizer, a stabilizer, a wax, a curing agent, a dispersant, a dye and the like can be blended in the ink-sensitive layer, if necessary.

The metal vapor deposition layer 3 has both functions as a heat-sensitive recording layer and a hydrophilic layer, and it is preferable to vapor deposit a hydrophilic metal having a low melting point. A metal having a melting point of 500 ° C. or lower is desirable, and examples of this metal include metals such as Sn, Pb, and Zn or alloys thereof, and vapor deposition of Sn is most suitable. The thickness of the deposited layer is 100Å to 1 micron, preferably about 500 to 1000Å. After the steps of heat-sensitive plate making, washing with water and desensitizing treatment (etching), the surface of the metal vapor deposition layer can be rendered hydrophilic by a desensitizing treatment.

Further, the protective thin film layer 4 is provided to protect the surface of the metal vapor deposition layer of the heat-sensitive plate of the present invention, and can prevent fingerprints from sticking to the vapor deposition surface and sticking of the thermal head.

In order to form such a protective layer, carboxymethyl cellulose, hydroxyethyl cellulose, cellulose derivatives such as methyl cellulose, polyvinyl alcohol, polyvinylpyrrolidone, casein, gum arabic, starch and the like which can easily remove the unheated portion by washing with water and starch A hydrophilic resin solution such as a derivative is applied on the metal deposition layer at 0.1 to 2.0 g / m ²
It may be applied.

This lithographic printing plate is made by destroying the selected portion of the metal vapor deposition layer and the protective thin film layer overlapping the portion with a heat source such as a thermal head and laser light, and after making the plate, the surface protective layer is rinsed off with a solvent etc. The metal vapor-deposited layer 3 is exposed to expose the metal vapor-deposited layer, and the metal vapor-deposited layer is hydrophilized to form a lithographic original plate, and a printed matter is obtained from the lithographic original plate. There is no support for image formation by the heat mode recording method. Since the lithographic original plate obtained by the present invention has the above-mentioned constitution, a printed matter having excellent gradation can be obtained.

(Examples) The features of the present invention will be further described below with reference to Examples and Comparative Examples.

Example 1 The following layers were sequentially laminated on a milk-white polyethylene terephthalate film having a thickness of 188 μm to obtain a lithographic printing plate precursor for heat-sensitive plate making.

(1) Ink oil sensitive layer Linear saturated polyester resin solution 20g Byron Co., Ltd. Byron 240 Solid content 40% Carbon black 1g Fine powder silica 1g Tokuyama Soda Co., Ltd. Fineseal 70 Average particle size 2.0μm Methyl ethyl ketone 10g Toluene 8g The drying temperature was 110 ° C., and the coating amount was 3.5 g / m ² in terms of dry weight.

SE-3AK made by Kosaka Laboratory for the center line average roughness of the ink-sensitive layer
When measured with a three-dimensional roughness measuring machine, the center line average roughness is
It was 0.60 μm.

(2) Metal vapor deposition layer Tin was vapor-deposited by a vacuum vapor deposition method so as to have a film thickness of 600 Å when measured by a film thickness measurement method using a crystal oscillator.

(3) Protective thin film layer 50 g of a carboxyl-modified polyvinyl alcohol 10% solution was applied at a drying temperature of 110 ° C. and a dry weight of an application amount of 1 g / m ² .

An image was recorded on the thermal recording medium thus prepared with a thermal head at a pulse width of 2.5 msec and an applied energy of 0.6 W. As a result, a thermal black plate having a clear black image was obtained against a silver-white background. The unheated part of the obtained heat-sensitive plate-making product is washed with water to remove the hydrophilic protective thin film layer, and then sodium silicate, phosphoric acid, etc. are soaked in a sponge and thinly applied to treat the metal surface, Etching was performed using a commercially available ordinary etching solution and printing was performed using an offset printing machine, and it was possible to obtain a stable and clear printed matter of 1000 sheets or more.

Example 2 The following layers were sequentially laminated on a milky-white polyethylene terephthalate film having a thickness of 188 μm to obtain a lithographic printing plate precursor for heat-sensitive plate making.

(1) Ink oil-sensitive layer Aqueous polyurethane resin solution 24 g Hydran AP-40 manufactured by Dainippon Ink Co., Ltd. Solid content 23% Carbon water dispersion 1.6 g Toyo Ink Co., Ltd. EM-K-14, 0.9 μm Solid content 35 % Calcium carbonate 5.0 μm 2.0 g 1% aqueous solution of sodium dodecylbenzene sulfonate 1.0 g Trimethylolpropane-tri-β-azirinyl propionate 0.2 g Drying temperature 110 ° C, coating amount 4.2 g / m ² dry weight Applied.

SE-3AK made by Kosaka Laboratory for the center line average roughness of the ink-sensitive layer
When measured with a three-dimensional roughness measuring machine, the center line average roughness is
It was 0.8 μm.

(2) Metal vapor deposition layer The same metal vapor deposition layer as in Example 1 was provided.

(3) Protective thin film layer The same protective thin film layer as in Example 1 was provided.

When the produced thermal recording medium was subjected to thermal plate making, surface treatment and etching treatment in the same manner as in Example 1 to perform printing, the same results as in Example 1 were obtained.

Example 3 The following layers were sequentially laminated on a milk-white polyethylene terephthalate film having a thickness of 188 μm to obtain a lithographic printing plate precursor for heat-sensitive plate making.

(1) Ink oil-sensitive layer The same ink oil-sensitive layer as in Example 1 was provided.

(2) Metal vapor deposition layer By the vacuum vapor deposition method, zinc was vapor deposited so as to have a film thickness of 600 Å when measured by the film thickness measurement method using a crystal oscillator.

(3) Protective thin film layer The same protective thin film layer as in Example 1 was provided.

When the produced thermal recording medium was subjected to thermal plate making, surface treatment and etching treatment in the same manner as in Example 1 to perform printing, the same results as in Example 1 were obtained.

Comparative Example Except that a protective thin film layer is not provided on the metal vapor deposition layer,
In the same manner as in Example 1, a lithographic printing plate precursor for heat-sensitive plate making for comparison was prepared. When the obtained original plate was used for plate making with a thermal head, sticking occurred and plate making was impossible.

(Effect of the Invention) Since the low melting point metal of the metal vapor deposition layer serves as the image forming layer, the lithographic printing plate precursor for heat-sensitive plate making of the present invention is used as a plate making plate by easily forming an image by the heat mode recording method. Even with a general-purpose thermal facsimile, there is an advantage that a plate-making process such as an electro-fax communication image or a word processor image can be made without a master plate, and a printed matter with good gradation can be obtained.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a plate-making material used in the present invention. 1; Support, 2; Ink oil-sensitive layer 3; Metal deposition layer, 4; Protective thin film layer

 ─────────────────────────────────────────────────── --- Continuation of the front page (72) Inventor Takeshi Suzuki 3-1, No. 1, Somune-cho, Shizuoka-shi, Shizuoka Pref., Technical Research Institute, Tomagawa Paper Mill Co., Ltd. (72) Koichi Aoyama, Soume-cho, Shizuoka-shi, Shizuoka No. 3 in Tomagawa Paper Mill Technical Research Institute

Claims (3)

[Claims] 1. A laminate comprising at least a metal vapor deposition layer provided on an ink oil-sensitive layer and a protective thin film layer provided thereon, the hydrophilic body comprising a protective thin film layer and a metal vapor deposition layer by heat sensitivity. A heat-sensitive plate-making method comprising plate-making by removing a layer portion. 2. The ink-sensitive layer has an average particle size of 1 to 10 μm.
The heat-sensitive plate-making method according to claim 1, characterized in that the center line average roughness is 0.5 to 1.5 µm. 3. The heat-sensitive plate-making method according to claim 1, wherein the metal layer is a metal having a melting point of 500 ° C. or lower.