JPS58225693A - Photocomposing method - 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] This invention relates to a plate-making method for offset printing.

In the conventional plate-making method for offset printing.

Photosensitive resin plate making is widely used, in which characters, images, etc. are laid out, an original picture is constructed using a photographic method, a photomask or the like is made, and the plate is made by exposing it to ultraviolet light or the like. In recent years, as a plate-making technology that is compatible with speed increases in plate-making speed and automatic layout using computer computers, in place of photography, information transmitted electronically and information stored in storage devices is directly converted into laser optical signals. There is increasing interest in laser plate making technology that performs plate making using laser light. However, when patterning image areas and non-image areas by irradiation with laser light, the sensitivity of printing plate materials to laser light is not necessarily sufficient, and there is a need for improvement.

The inventors of the present invention have conducted extensive studies to meet the above requirements.
We have discovered a simple plate-making method for offset printing using visible or near-infrared lasers, and have arrived at the present invention.

That is, the present invention is applicable to Otsu00~/. A printing plate in which a photosensitive layer consisting of a photosensitive agent that has maximum absorption in the visible light of 200 nm or in the near-infrared region and a heat-meltable resin is formed on a transparent film, and becomes a non-ink receiving layer when wet with water. After bonding with the support, the oscillation wavelength is 0θ~/ through the transparent film.
, by irradiation with 200 nm visible or near-infrared laser light.

This is a plate-making method that consists of thermally melting the irradiated portion of the photosensitive layer and transferring it to a support, and then peeling off and removing the non-irradiated portion along with the transparent film.

The photosensitizer used in the present invention is preferably a compound having maximum absorption at a wavelength of 00 to 200 nm, and has a single molecule extinction coefficient of 10,000 or more at the maximum absorption wavelength, and is roughly classified into S types, that is, aromatic diamine metal complexes. , aliphatic diamine metal complexes.

Aromatic dithiol metal complexes, aliphatic dithiol metal complexes, mercaptophenol metal complexes, and the like can be used.

The aromatic diamine metal complex has the general formula (■) C, where X
is hydrogen, alkyl group, substituted alkyl group.

For halogen groups and nitro groups, In is an integer of /-4.

M is a compound represented by nickel, cobalt, palladium, platinum), among which bis(q-chloro-O-phenylenediamino)nickel (extremely absorbent)
ax gθQ n m, molar specific extinction coefficient ε Otsu Otsu 00
) and bis(gumethyl-〇-phenylenedimethylamino)nickel (containing maX 7951mlε5sioo) are preferred because they are easy to synthesize and have excellent compatibility with resins.

For aliphatic diamino metal complexes, general formula (■) C, where Y
is hydrogen, alkyl group, phenyl group, cyan group, M is nickel, cobalt, palladium.

A compound represented by platinum (representing platinum), especially bis(diiminosuccinonitrilo)platinum (representing max l'
IQ ++m, ε32θ00) and Bi, <(diiminozakudinonitrilo)nickel (input max 700
．． 1n m, ε, 23! ;00) is preferred because it is easy to synthesize and has excellent compatibility with resins.

The aromatic dithiol metal complex has the general formula (III)0, where Z is hydrogen, an argyl group, or a halogen group.

n is an integer from 7 to 1M is nickel or cobalt.

Palladium, platinum, nl is an integer of 1 or -1.

A is a compound represented by (when m is -l, it represents a 7-valent cation; when In is 1, it represents an Ω-valent cation),
Among them, especially bis(/-methyl-3°goutithioferrate)nickel(II)tetra-n-butylammonium (maxgqOnm, ε/f 270) and bis(/, 2,3.gutetrachloro-s). , b-dithioferrate) nickel (■) tetra-n-butylammonium (input max 3 nm, ε/left 700) is preferred because it is easy to synthesize and has excellent compatibility with the resin.

The aliphatic dithiol-based metal complex has the general formula (IV) (wherein E represents hydrogen, an alkyl group, or a phenyl group.

M represents nickel, cobalt, palladium, platinum)
A compound represented by, among which bis[cis/,2
-bis(p-methoxyphenyl)ethylene-/,2-dithiolate]nickel (max q, 2onm, e
3sooo) and bis(cis/, 2-bisphenylethylene-/, , :l-dithiolate)platinum (max.
g QQ nm, t3/Otsu00) is preferred because it is easy to synthesize and has excellent compatibility with resins.

The mercaptophenol metal complex has the general formula c, q
is hydrogen, alkyl group, and halogen group.

M [nickel, cobalt, palladium, platinum.

When m is -) or an integer of -1, when m is 1/1, it represents a heptavalent cation; when 1m is -Ω, it represents a divalent cation), and among them, especially rC bis ( /-mercaptoconaphthlate)nickel(II)tetra-n-butylammonium (max. / /θQnm
, e /, 22900) and bis(/-mercaptocofert) nickel (■) tetra-n-butylammonium (in maX10.2 left nm, ε/270
0) is easy to synthesize.

It is preferred because it has excellent compatibility with the resin.

The heat-meltable resin used in the present invention is used in combination with the above-mentioned photosensitizer, but in general, any conventional thermoplastic resin or slightly crosslinked resin can be used, based on the principle r(d- Either of these can be used. However, it is necessary that the ink does not attack during offset printing, so it is necessary to cure it by a thermosetting reaction during laser irradiation, or to apply heat or ultraviolet rays after transferring it to the printing plate support. It can be cross-linked. Examples include acrylic ester copolymers, polystyrene, vinyl acetate copolymer resins, natural rubber, polybutene, polybutadiene, polyisoprene, SBR, NBH, and alkyd resins.

polyester resin, polyurethane resin, epoxy resin,
A polymer resin that melts when heated, such as a cellulose acetate resin, is used, and a resin component such as an aminoformaldehyde resin, a polyvalent vinyl resin, or an isocyanate oligomer, which serves as a crosslinking agent, may be used in combination.

The above photosensitizer and resin components are usually dissolved in an organic solvent, then coated on a transparent film, and the solvent is removed by drying to form a photosensitive layer with a thickness of generally 3 to 30 μm. It is also possible to melt-mix the photosensitizer and resin component, form a film by extrusion, and then form a multilayer film with a transparent film.

The transparent film used in the present invention is a smooth film that transmits laser light, such as polyester film, cellulose acetate film, polyethylene film, polypropylene film, polycarbonate film, vinyl chloride film, vinylidene chloride film, polyacrylic acid ester film, etc. can be given. In the method of the invention.

In order to control the adhesive force between the photosensitive layer and the transparent film when the photosensitive layer irradiated with laser light is transferred to the sheet-like support and the non-irradiated area of the photosensitive layer is peeled off together with the transparent film. .

It is also possible to use a transparent film coated with an adhesive resin composition that contributes to increasing adhesive strength, or a silicone-based release property imparting composition that conversely contributes to decreasing adhesive strength.

The printing plate support used in the present invention to which the photosensitive layer is transferred is as follows:
An aluminum plate that absorbs water when wet with soaking water and becomes a non-receptive layer for offset printing ink.

Metal, although anodized plates are the most common.

Materials such as plastic and paper treated with hydrophilic resin are also used, and the shape is usually sheet-like or cylindrical.

The printing plate support is pressed against the photosensitive layer surface of a transparent film having a photosensitive layer using vacuum suction or a laminator, and the transparent film is exposed to laser light.

The laser used in the present invention is a visible or near-infrared laser that emits an oscillation wavelength of to[theta]~/2[theta] Onm, such as various semiconductor lasers, helium/neon lasers, YAG lasers, and the like. The laser light is
Transmitted information or stored information is converted from electrical signals to laser light signals, and the laser light corresponding to one drawing area is optically narrowed down to a spot beam of usually 7 to 70 θμ and scanned.

The photosensitive layer is irradiated through a transparent film. In the area irradiated with the laser beam, the photosensitizer absorbs the laser beam and rapidly generates heat, so the temperature of the photosensitive layer in the area irradiated with the laser beam instantly reaches 100 to 5,000 degrees Celsius, and the resin in the photosensitive layer melts, making the print. Only the portion of the plate support that is hit by the laser beam is fused. Generally, immediately after laser light irradiation, the photosensitive layer surface and the printing plate support are pressed together using a pressure roll or the like, and then when the transparent film having the photosensitive layer is peeled off from the printing plate support, the photosensitive layer irradiated with the laser light is removed. Only the layer portions are transferred to the surface of the printing plate support to obtain an offset printing plate.

In order to achieve the plate-making method of the present invention with high accuracy, it is desirable that the following adhesive force relationship be established between the transparent film, the photosensitive layer, and the printing plate support to which the photosensitive layer is transferred. .

f] (A, B) Adhesive force fl between the transparent film and the photosensitive layer in the area not irradiated with the laser beam fl (BC) Adhesive force fz between the photosensitive layer and the sheet support in the area not irradiated with the laser beam fz (Al1) In the area irradiated with the laser beam Adhesive force between the transparent film and the photosensitive layer fz (BC) Adhesive force between the photosensitive layer in the laser beam irradiated area and the sheet support fl (AB) > fl (BC) fz (Al1) < fz (BC) Such adhesive force to adjust the balance.

The transparent film material, the resin component for the photosensitive layer, and the sheet-like support as described above are appropriately combined and used. Further, the transfer of the photosensitive layer or the printing plate support is heated or irradiated with ultraviolet rays, electron beams, infrared rays, microwaves, etc. to cause a crosslinking reaction in the photosensitive layer.

It is also preferable to increase the strength of the photosensitive layer that becomes the ink-receiving layer.

The above method r (thus, the offset plate made by plate making is.

1 line by offset printing using a conventional offset printing machine in the normal operating manner.

It is possible to obtain high-quality printed matter with clear boundaries in non-image areas and no background stains.

Hereinafter, the plate-making method of the present invention will be specifically explained with reference to Examples.

Example/ On a polyester film with a thickness of S0μ, 100 f of a 30% methyl ethyl ketone solution of methyl methacrylate and ethyl acrylate copolymer and bis □IC/, 2,
3. Gutetrachloro-3, O-dithioferlate)
A solution prepared by mixing and dissolving nickel (II) tetra-n-butylammonium (input max g g 5 n rn ) 3 f was applied using a reverse roll coater, and go'
In step (a), the solvent was removed by heating for 20 minutes to form a photosensitive layer of J warp Sμ.

The thickness of the polyester film having this photosensitive layer is θ, 2
Layer it on my friend's alumite plate (so that the photosensitive layer surface and the alumite plate are in contact), apply suction through the air, and make a close contact. rn, output cuff 0 mW) was scanned with an optical r (diameter, !θμ) spot beam, and then the polyester film was peeled off from the alumite plate. The laser beam irradiated portion of the photosensitive layer was transferred to the alumite.

A printing plate was obtained in which the non-irradiated area was peeled off together with the polyester film.

When this printing plate was attached to an ordinary offset rotary press and offset printing was performed using soaking water, a printed matter with clear image areas without background fog was obtained.

Example λ Hydroxyl group-containing polyester resin 30#.

A 50% butanol solution of butylated methylolmelamine resin! Ot and bis(iminosuccinonitrilo)platinum (
A photosensitive agent 3i containing max l'i Qnm) was dissolved in a solvent of 3 toluene and 36 tons of tetrahydrofuran, and this solution was coated on a cross-linked polyethylene film with a thickness of 0 μ using a bath roll coater and coated with 1 g of 3
After drying for θ minutes, the solvent was removed to form a photosensitive layer with a thickness of 7 μm.

The thickness of the crosslinked polyethylene film having this photosensitive layer is θ
, and two alumite plates (so that the photosensitive layer and the alumite plate are in contact with each other), vacuum suction is applied to bring them into close contact, and a helium-neon laser (oscillation wavelength 33 nm, output / □ m W ) was optically focused and scanned with a spot beam having a diameter of 20 μm, and then the polyethylene film was peeled off from the alumite plate. The laser beam irradiated areas of the photosensitive layer were transferred to the alumite, and the non-irradiated areas were peeled off together with the polyethylene film. The alumite plate on which the photosensitive layer was transferred was heated in a hot air dryer to /5Q'O for 30 minutes to obtain a printing plate with the photosensitive layer crosslinked.

When this printing plate was attached to an ordinary offset rotary press and offset printing was performed using soaking water, a printed matter with clear image areas without background fog was obtained.

Example 3 Ethyl acrylate-styrene co-TE combination 30#.

Trimethylolpropane triacrylate sit.

Benzine ethyl ether 0. ! ;f and (j bis C)-
Mercapto-2-naphtholate) Nickel(II) Tetra-n-butylammonium (max. / / 00
Photosensitizer 31 of Ryu M) was dissolved in ethylene glycol monomethyl ether Otsu 02, and this solution was coated with a reverse roll coater on a 30μ thick polycarbonate film coated with a releasable silicone film, and dried at /θ0C for 30 minutes. , the solvent was removed to form a photosensitive layer with a thickness of 3 lt.

The polycarbonate film with this photosensitive layer is made into a film with a thickness of 0.
．． Layer the alumite plate of 2 Dragons (so that the photosensitive layer and the alumite plate are in contact), apply vacuum suction to bring them into close contact, and apply a YAG laser (oscillation wavelength 10) over the polycarbonate film.
The polycarbonate film was peeled off from the alumite plate after scanning with a spot beam having a diameter of 20 μm by optically focusing the beam (Q n m , output/QmW). The laser beam irradiated areas of the photosensitive layer were transferred to alumite, and the non-irradiated areas were peeled off together with the polycarbonate film. The alumite plate on which the photosensitive layer had been transferred was exposed to ultraviolet light by passing it under a gOW/c1n high-pressure mercury lamp to obtain a printing plate in which the photosensitive layer was photocured.

This printing plate was used for offset printing in the same manner as in Example 1 to obtain printed matter having clear image areas without background blemishes.

patent applicant Mitsui Toatsu Chemical Co., Ltd.

Claims (1)

[Claims] (1) A photosensitive layer consisting of a photosensitizer that has maximum absorption in the visible light or near infrared wavelength region of AOθ~20θnm and a heat-meltable resin is formed on a transparent film, and when it gets wet with water, the ink does not disappear. After being pressure-bonded to the printing plate support that will become the receiving layer, the oscillation wavelength is 0~/, 20 through the transparent film.
A plate making process characterized by irradiating visible or near-infrared laser light of Q+1m to thermally melt the irradiated part of the photosensitive layer and transferring it to a support, and then peeling off and removing the non-irradiated part together with a transparent film. Method.