JP2000318116A - Offset printing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an offset printing method which satisfies the suitability for simple plate-making not using a developer, the printed image quality backed with the discriminability between an image part and a non-image part of a printing surface and a sufficient resistance to printing altogether. SOLUTION: An original plate for printing which has on the surface a metal having characteristics of high-temperature hydrophilic nature development is made hydrophobic and then the surface is subjected to image-pattern heating at the temperature of the high-temperature hydrophilic nature development, so as to form a hydrophilic/hydrophobic regional image-pattern distribution thereon. A water solution containing a water-soluble compound of a metal having a lower ionization tendency than the metal having the characteristics of the high-temperature hydrophilic nature development is brought into contact with the original plate and a metal thin layer is formed in an image pattern in the hydrophilic region by metal substitution. Moreover, a treatment for giving the hydrophilic nature to the hydrophobic region is executed and the original plate for printing thus treated is brought into contact with ink. Thereby a printing surface having received the ink is formed in the region having the metal thin layer and printing is conducted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to the field of general light printing,
In particular, the present invention relates to offset printing, and particularly to a novel offset printing method and a printing original plate that can easily produce a printing plate. In particular, the present invention relates to an offset printing method and an original plate for printing in which simplicity of a plate making process and printing durability are compatible, and in which printing smear is reduced.

[0002]

2. Description of the Related Art The offset printing method has been widely used especially among the many printing methods due to the simplicity of the printing plate manufacturing process, and is the main printing method at present. This printing technique is based on the immiscibility of oil and water, with the image areas selectively retaining oily material or ink and the non-image areas selectively retaining fountain solution. Therefore, when the surface to be printed is brought into direct contact with the surface to be printed or indirectly through an intermediate called a blanket, the ink in the image area is transferred and printing is performed.

The main method of offset printing is a PS plate having an aluminum substrate as a support and a diazo photosensitive layer coated thereon. In the PS plate, the surface of the aluminum substrate, which is the support, is subjected to graining, anodic oxidation, and other treatments to enhance the ink receiving capacity of the image area and the ink repulsion of the non-image area, thereby improving the printing durability. Then, the printing surface is refined, and a printing image is formed on the surface. Therefore, offset printing has been provided with characteristics such as printing durability and high definition of a printing surface in addition to simplicity.

[0004] While the use of the offset printing method has been widespread and spread in the general printing field due to high definition, further simplification of the offset printing method has been demanded, and many simple printing methods have been proposed.

[0005] From the above background, there has been developed a method of manufacturing a simple printing plate in which a developing step using an alkali developing solution after image exposure is omitted. In the technical field of this simple printing plate, which is also called an unprocessed printing plate because the development step can be omitted, the image formation by thermal destruction of the irradiated portion on the image recording surface mainly by imagewise exposure, Image formation by lipophilicity and lipophilicity of the irradiated part are also based on various principles such as photo-mode curing, changes in surface properties due to photolysis of diazo compounds, and heat mode fusion thermal transfer of image areas. Proposed.

As described above, many simple printing methods which do not require a developing solution for plate making have been devised, but the difference between the lipophilic region and the hydrophilic region is insufficient, and therefore the image quality of the printed image is low. Is poor, the resolution is poor, it is difficult to obtain a printed screen with excellent sharpness, the mechanical strength of the image surface is insufficient and it is easily scratched, and the simplicity is rather impaired by providing a protective film for it. thing,
It is accompanied by at least one of the drawbacks, such as insufficient durability to withstand long-time printing, and indicates that simply eliminating the alkali development step does not involve practicality. In spite of the above-mentioned many improvements, a strong demand for a printing plate preparation method that has various characteristics required for printing and can easily produce a printing plate has not been sufficiently satisfied.

[0007]

Under such circumstances, the present inventor has found a phenomenon in which the degree of hydrophobicity or hydrophilicity of the surface is changed by the action of heat, and development using this property is necessary. A printing method with improved simplicity was devised. However, there is a strong demand in the market for a printing method that satisfies both simplicity, discrimination between an image portion and a non-image portion, and furthermore, printing durability. In particular, further improvement in printing durability is desired.

[0008] In view of the above circumstances, the problem to be solved by the present invention is to provide a simple plate-making suitability without using a developing solution, and a sufficient print quality supported by the discrimination between the image area and the non-image area on the printing surface. An object of the present invention is to provide an offset printing method satisfying both printing durability.

[0009]

SUMMARY OF THE INVENTION The present inventor has further improved the discrimination and printing durability of the above-mentioned simple printing method utilizing the phenomenon that the degree of hydrophobicity or hydrophilicity of the surface changes by the action of heat. Was studied diligently. As a result, this book succeeded in reinforcing the image area of the plate surface by replacing the metal only in the hydrophilic area of the image-like distribution formed by heating, and improving both simplicity, discrimination and printing durability. It has been found that the purpose of the invention is satisfied.

According to the present invention, a printing original plate having a metal having a high-temperature hydrophilicity developing property on its surface is brought into contact with an organic compound or heated to a hydrophobic developing temperature to make the printing original plate surface hydrophobic. Next, the surface is imagewise heated at a high hydrophilicity developing temperature to change the irradiated portion or the heated portion to be hydrophilic, thereby forming an image-like distribution of a hydrophobic region and a hydrophilic region, and forming the image-like distribution. Contacting an aqueous solution containing a water-soluble compound of a metal having a lower ionization tendency than a metal having at least the high-temperature hydrophilicity developing property on a printing original plate having, and by metal replacement, to a hydrophilic region on the printing original plate. A thin metal layer of the metal having a low ionization tendency is formed imagewise, and the hydrophobic area is subjected to a hydrophilic treatment, and the printing plate is brought into contact with ink to form an area having the thin metal layer. I Key to form a printing surface receiving a
This is an offset printing method characterized by performing printing.

The preferred embodiments of the present invention are as follows.

1. The temperature at which the surface of the printing plate becomes hydrophobic
An offset printing method at 0 to 250 [deg.] C., wherein the surface of the printing original plate is heated at a temperature at which hydrophobicity is exhibited to make it hydrophobic.

2. The surface of the printing plate is the third in the periodic table
An offset printing method, wherein the method comprises at least one of a metal selected from elements other than Group 0 and Group VIIA (halogen element).

3. The surface of the printing plate is aluminum,
An offset printing method comprising a metal selected from iron, copper, germanium, nickel, zinc, tin and silicon or at least one of its alloys.

4. Hydrophobicization of the printing original plate surface is performed by exposing the printing original plate to an atmosphere containing an organic compound gas, applying or spraying a liquid organic compound or a liquid containing an organic compound onto the printing original plate, and applying a liquid organic compound to the printing original plate or An offset printing method, which is performed by immersion in an organic compound-containing liquid.

5. An offset printing method, wherein the organic compound is an organic compound having a vapor pressure of at least 10 mmHg at a temperature of 20 ° C.

6. An offset printing method, characterized in that the organic compound is an organic compound that dissolves in at least 5 wt% in at least one organic solvent selected from ethanol, acetone, benzol and 2,2,4-trimethylpentane at a temperature of 20 ° C.

[7] An offset printing method characterized in that the means for making the hydrophobic area of the surface of the printing original plate hydrophilic before the printing is a means selected from heating to a high-temperature hydrophilicity developing temperature and washing the hydrophobic area.

8. An offset printing method, wherein imagewise heating performed at a high temperature at which hydrophilicity is exhibited is performed by a heating means selected from a thermal recording head and a photothermal conversion type radiation.

9. An offset printing method, wherein a printing plate is manufactured from the printing plate while the printing plate is mounted on a printing press, and printing is performed.

In the present invention, "a metal having a high-temperature hydrophilic property" is used as a material for a printing original plate.

The term "metal having high-temperature hydrophilicity-imparting properties" means that it becomes hydrophilic when heated to a certain temperature or higher, and this hydrophilicity has a hysteresis and maintains its surface hydrophilicity to some extent even when it is returned to normal temperature. Metal. The temperature at which the hydrophilicity appears is called "high-temperature hydrophilicity-expressing temperature".

Among metals, those whose clean surfaces are inherently hydrophobic to varying degrees, and those whose surfaces are inherently hydrophilic are also referred to as "hydrophobic expression temperatures". The present inventors have found that some exhibit a change from hydrophilic to hydrophobic when heated to temperature. Among these metals, there were also observed metals whose surfaces became hydrophobic again when heated further beyond the temperature at which hydrophobicity was developed. Some of the “metals having high-temperature hydrophilicity-developing properties” exhibit hydrophobicity at such an intermediate heating temperature.

The present invention provides a further discovery that, in addition to the above-mentioned properties of a metal having a high-temperature hydrophilicity developing property, the surface of the above-mentioned metal which is in a hydrophilic state at room temperature has a property of becoming hydrophobic when it comes into contact with an organic compound. It was also made using.

Further, an image-like distribution of a hydrophobic region and a hydrophilic region is formed on a printing original plate, and this surface is formed of a metal having a lower ionization tendency than a metal having a high-temperature hydrophilicity developing characteristic constituting the surface of the printing original plate. They have also found that when they are brought into contact with an aqueous solution containing a water-soluble compound, a metal substitution reaction occurs selectively in a hydrophilic region, and a metal having a low ionization tendency is formed in this region.

The printing method of the present invention is a novel invention achieved by using the physical properties and phenomena described above in combination.

The printing method of the present invention comprises using a "metal having high-temperature hydrophilicity" as a printing plate and performing the following steps.

The first step is to make the surface of the metal printing plate hydrophobic. As a method of making the surface hydrophobic, there are a method of making an organic compound act and a method of heat treatment. The former involves exposing the surface of the printing plate to the vapor of an organic compound, spraying or applying an organic compound in a liquid or solution state to the surface of the printing plate, or applying the printing plate to a liquid organic compound. It is performed by a method such as immersion. The latter is a means that can be applied when the metal having the high-temperature hydrophilicity development characteristics of the printing original plate is a hydrophobicity-expressing metal that becomes hydrophobic by moderate heating. The surface can be hydrophobic.

In the second step, an image-like hydrophilic area is formed on the surface of the printing plate which has been rendered hydrophobic. At this stage, the surface of a printing plate having a metal having a high-temperature hydrophilicity manifesting property on its surface (hereinafter, also simply referred to as “printing plate”) is imagewise heated, and the heated portion is made hydrophilic. By doing so, a hydrophilic region is formed, and a portion that is not heated is formed as a hydrophobic region, whereby an image-like distribution of the hydrophilic region and the hydrophobic region is formed on the surface of the printing original plate.

The third step is a step of imagewise providing a thin metal layer in the hydrophilic region on the printing original plate in which the imagewise distribution of the hydrophilic region and the hydrophobic region has been formed. At this stage, an aqueous solution containing a water-soluble compound containing a metal having a low ionization tendency is brought into direct contact with the printing original plate. This contact causes metal substitution in the imagewise hydrophilic regions, but not in the hydrophobic regions.

Therefore, a metal having a low ionization tendency selectively in the hydrophilic image-like region is replaced with a metal having a high-temperature hydrophilicity developing property, and is deposited on the original printing plate. Is obtained.

The fourth step is an operation for making the hydrophobic region hydrophilic by applying a hydrophilic treatment to the hydrophobic region where the metal substitution has not occurred. The removal is performed by means such as washing and removal, and heating to a high temperature at which hydrophilicity is exhibited.

The fifth step is a printing step. By contacting the printing master with the ink, the imagewise-distributed hydrophobic regions receive the printing ink and form a printing surface.

By performing the above series of operations, a printing plate is made from a printing original plate, and printing is performed using the printing plate.

In the second step, the surface of the metal having the property of exhibiting high-temperature hydrophilicity is changed from hydrophobic to hydrophilic by heating at the temperature at which high-temperature hydrophilicity is exhibited. Due to the hysteresis effect, the hydrophilicity is maintained for a practically sufficient time. Therefore, the effective hydrophilic region on the surface, which has sufficiently promoted the hydrophobicity by contact with the organic compound, is maintained for a practical period of time, so that the above-described third-stage metal substitution has an effect on the hydrophilic region. And a thin metal layer is formed. Since this metal thin layer is more hydrophobic than the metal having the high-temperature hydrophilicity developing property, the hydrophobic region where the metal thin layer was not formed is subjected to a hydrophilic treatment, so that the metal thin layer is formed. The ink can be put on and printed.

According to the present invention, a direct plate-making / printing method that does not require development by utilizing the change in the properties of the hydrophobic to hydrophilic properties of the printing plate surface as described above is possible. Moreover, in addition to the simplicity of the direct plate making, the present invention has the advantage that the printing durability can be improved by reinforcing the plate surface with a thin metal layer.

[0037]

(Printing plate)

(Printing Plate Material) First, a printing plate material that can be used in the present invention will be described.

Next, the "metal having a high-temperature hydrophilic property" which becomes hydrophilic when heated at a high temperature and shows a hysteresis phenomenon will be described. Preferred high temperature hydrophilicity developing metals belong to the third to sixth periods of the periodic table, and are selected from at least one of the metals selected from elements other than group 0 and group VIIA (halogen element). It is configured.

The metal having "high-temperature hydrophilicity-developing property" is
It is found both in single composition metals and in composite compositions or alloys. In the case of an alloy, any of a metal solid solution, an intermetallic compound, and a metal microcrystal mixture may be used. Further, as seen in stainless steel (hereinafter referred to as SUS), a passive oxide film may be formed on the surface. Further, a process of forming an oxide film positively, such as anodic oxidation, may be performed. Further, there is no particular restriction on the purity of a single kind of metal or alloy, and the purity of a single kind of metal or alloy can be applied to the present invention as long as it is used for ordinary general use.

Preferred metals are aluminum, iron, silicon, nickel, zinc, germanium, tin and copper and their alloys. A particularly preferred metal is aluminum. When using aluminum, it is preferable to directly use an aluminum plate, which is a support for a printing original plate described later, and thus enhance the hydrophilicity of the surface by mechanical graining or electrolytic roughening, An anodized aluminum plate is used.

As a form of use of the metal having the property of exhibiting high-temperature hydrophilicity, a metal plate can be used as it is, or an appropriate plastic film or another metal plate is used as a support and electroplating and bonding are performed thereon. It may be provided by such as. The thickness of the metal plate on the support can be any thickness smaller than the support, but the preferred thickness is about 0.01 mm to 0.4 mm, more preferably 0.02 mm to 0.2 mm. .

As described above, most of the metals having the property of exhibiting high-temperature hydrophilicity have the property of exhibiting hydrophobicity by moderate heating at a temperature lower than the temperature of exhibiting high-temperature hydrophilicity. As an alternative, moderate heating may be performed instead of contacting with an organic compound. Further, both means may be used in combination. The temperature at which hydrophobicity is developed varies depending on the metal, but is usually 50 to 250 ° C.

Since the metal having a high-temperature hydrophilicity characteristic that can be used in the present invention must not be excessively dissolved in fountain solution when used as a printing plate, its solubility in water is 10m for 100ml
g or less, preferably 5 mg or less, more preferably 1 mg
It is as follows.

The above description of the metals having high-temperature hydrophilicity development properties used in the present invention, particularly the preferred metals, is completed, and then the form of the original printing plate carrying these materials is described. (Form of printing original plate) Various forms can be used for the printing original plate according to the present invention. For example, a method of directly providing a thin layer of a metal having a high-temperature hydrophilic property on a substrate surface of a plate cylinder of a printing press by a method such as vapor deposition, dipping or coating, or having a high-temperature hydrophilic property supported on a support. A method of winding a metal or a thin plate of the above-mentioned metal having no support around a substrate of a plate cylinder, and the like, and a method of forming a printing plate with these printing original plates mounted on a printing machine are preferable.

Of course, in addition to the above-described form of making a plate on a plate cylinder, a form in which the plate is made may be mounted on a rotary-type or flat-bed-type printing machine, as is generally performed. .

When the metal having the property of exhibiting high-temperature hydrophilicity is provided on the support, the support used is a plate which is not thermally decomposed even at the temperature at which high-temperature hydrophilicity develops and is dimensionally stable. , Flexible plastic supports such as polyesters and cellulose esters, supports such as waterproofed paper, polyethylene laminated paper, impregnated paper and supports with an oxide layer provided on the support, flexible (flexible) Metal plates and the like can be mentioned.

As the support material, a metal having a high-temperature hydrophilicity developing property can be used. In this case, the support itself is preferably used as a printing original plate. When a metal having high-temperature hydrophilicity is provided on another metal support, the combination is appropriately optimized.

Specifically, paper, paper laminated with a plastic sheet (eg, a sheet of polyethylene terephthalate, polyimide, etc.), a metal plate (eg, aluminum, zinc, copper, stainless steel, nickel, etc.), plastic film (eg, , Cellulose diacetate, cellulose triacetate, cellulose propionate, cellulose butyrate,
Cellulose acetate butyrate, cellulose nitrate, polyethylene terephthalate, polyimide, polystyrene, polycarbonate, polyvinyl acetal, etc.), metal-laminated or vapor-deposited paper, or plastic film.

A preferred support is a polyester film, a polyimide film, aluminum or a SUS plate which is hardly corroded on a printing plate. Among them, an aluminum plate which has good dimensional stability and is relatively inexpensive, Polyimide films that are highly stable to operation are particularly preferred.

A preferred polyimide film is a polyimide resin film obtained by polymerizing pyromellitic anhydride and m-phenylenediamine and then performing cyclic imidization.
This film is commercially available (for example, “Kapton” manufactured by Dupont Toray) can be mentioned.

Suitable aluminum plates are a pure aluminum plate and an alloy plate containing aluminum as a main component and a trace amount of a different element, and may be a plastic film on which aluminum is laminated or vapor-deposited. The foreign elements contained in the aluminum alloy include silicon, iron, manganese, copper, magnesium, chromium, zinc, bismuth, nickel, and titanium. The content of the foreign element in the alloy is at most 10% by weight or less. Aluminum which is particularly preferred in the present invention is pure aluminum. However, completely pure aluminum is difficult to produce due to refining technology, and therefore may contain a slightly different element. As described above, the composition of the aluminum plate applied to the present invention is not specified, and an aluminum plate of a conventionally known and used material can be appropriately used. The thickness of the metal support used in the present invention is about 0.1 mm to 0.6 mm, preferably 0.15 mm to 0.4 mm, particularly preferably 0.2 mm
The thickness of other supports such as plastic and processed paper is about 0.1 mm to 2.0 mm, preferably 0.2 mm to 1.0 mm.

When an aluminum support is used, it is preferable to use a roughened surface. In this case, if desired, a degreasing treatment with a surfactant, an organic solvent, an alkaline aqueous solution, or the like is performed to remove the rolling oil on the surface prior to the surface roughening.

The surface roughening treatment of the aluminum plate is performed by various methods. For example, a method of mechanically roughening the surface, a method of electrochemically dissolving and roughening the surface, and a method of chemically roughening the surface. Is selectively dissolved. As a mechanical method, a known method such as a ball polishing method, a brush polishing method, a blast polishing method, and a buff polishing method can be used. In addition, as the electrochemical surface roughening method, a known method such as performing an alternating or direct current in a hydrochloric acid or nitric acid electrolyte can be used. Further, the roughened aluminum plate is subjected to an alkali etching treatment and a neutralization treatment as required, and then subjected to an anodic oxidation treatment, if necessary, in order to increase the water retention and abrasion resistance of the surface. The concentration of the anodic oxidation electrolyte is appropriately determined depending on the type of the electrolyte.

The anodizing treatment conditions vary depending on the electrolyte used and cannot be specified unconditionally. However, in general, the concentration of the electrolyte is 1 to 80% by weight, the solution temperature is 5 to 70 ° C.
It is appropriate that the current density is 5 to 60 A / dm ² , the voltage is 1 to 100 V, and the electrolysis time is 10 seconds to 5 minutes.

If the amount of the anodic oxide film is less than 1.0 g / m ² , the printing durability is insufficient, and the non-image area of the lithographic printing plate is easily scratched. The so-called "scratch stain" to which ink adheres easily occurs.

In order to enhance the high-temperature hydrophilicity developing characteristics of the printing original plate, it is effective to provide a heat insulating layer below the image forming layer. When drawing by light-to-heat conversion is performed, a light-to-heat conversion layer may be provided as a lower layer when the functional surface is transparent to the light.

In the above, the material, the support, and the structure of the printing original plate using the metal having high-temperature hydrophilicity used in the printing method of the present invention have been described. Next, a plate making method using this printing original plate will be described in the order of the first to fifth operations. [Plate Making Step] (Entire Hydrophobicity) The first step is to make the metal having the high-temperature hydrophilicity developing properties as described above entirely hydrophobic. The entire surface is rendered hydrophobic by contacting it with an organic compound as described above, or, in the case of a metal having the property of changing to hydrophobic by heating, also by heating the metal to a hydrophobic expression temperature. . In the latter case, it has been found that the presence of an organic compound promotes hydrophobicity. Therefore, it is also preferable to contact the organic compound at a temperature at which hydrophobicity is developed. Further, as described above, the method of bringing the organic compound into contact with the organic compound can be a method such as gas phase contact, coating, spraying, and dipping.

The organic compound used for hydrophobization will be described. Preferred organic compounds having the effect of rendering the surface of the printing original plate hydrophobic are those having a vapor pressure of at least 1 mmHg at a temperature of 400 ° C. and a temperature at which the vapor pressure becomes 1 mmHg. That is, if an organic compound having such a vapor pressure is present in a state in which it can come into contact with the original printing plate, the discrimination between hydrophilicity and hydrophobicity is improved. More preferably, the vapor pressure at a temperature of 300 ° C. is at least 1 mmHg and the vapor pressure is 1
It is a stable organic compound at a temperature of mmHg.
More preferably, it is an organic compound having a boiling point of 30 to 400 ° C. and stable in a temperature range of 30 to 400 ° C., and a particularly preferable boiling point is 50 to 350 ° C.

From another viewpoint, an organic compound having a vapor pressure of at least 10 mmHg at 20 ° C. is preferable.
In the case of solid compounds, ethanol, acetone,
Those which are dissolved in an organic solvent such as benzol or 2,2,4-trimethylpentane are preferable because they can be applied to the original printing plate in the form of a solution. Organic compounds having a boiling point in this temperature range include aliphatic and aromatic hydrocarbons, aliphatic and aromatic carboxylic acids, aliphatic and aromatic alcohols, aliphatic and aromatic esters, aliphatic and aromatic It is found in ethers, organic amines, organic silicon compounds, and various solvents and plasticizers which are not so effective but can be added to printing inks.

Preferred aliphatic hydrocarbons are those having 8 to 3 carbon atoms.
0, more preferably an aliphatic hydrocarbon having 8 to 20 carbon atoms, and a preferred aromatic hydrocarbon has 6 to 40 carbon atoms.
And more preferably an aromatic hydrocarbon having 6 to 20 carbon atoms. Preferred aliphatic alcohols have 2 to 30 carbon atoms.
Are more preferably aliphatic alcohols having 2 to 18 carbon atoms, and preferred aromatic alcohols are those having 6 to 30 carbon atoms.
And more preferably an aromatic alcohol having 6 to 18 carbon atoms. Preferred aliphatic carboxylic acids have 2 to 24 carbon atoms.
Aliphatic carboxylic acid, more preferably having 2 to 2 carbon atoms
Preferred are aliphatic monocarboxylic acids having 20 and aliphatic polycarboxylic acids having 4 to 12 carbon atoms, and preferred aromatic carboxylic acids are those having 6 to 30 carbon atoms, and more preferably having 6 to 30 carbon atoms.
18 aromatic carboxylic acids. Preferred aliphatic esters have 2 to 30 carbon atoms, more preferably 2 to 1 carbon atoms.
And preferred aromatic esters are those having 8 to 30 carbon atoms, more preferably 8 to 18 carbon atoms.
Is an aromatic carboxylate. Preferred aliphatic ethers are those having 8 to 36 carbon atoms, more preferably 8 carbon atoms.
To 18 aliphatic ethers, and preferred aromatic ethers are those having 7 to 30 carbon atoms, more preferably 7 to 1 carbon atoms.
8 aromatic ethers. In addition, carbon number 7-30
And more preferably an aliphatic or aromatic amide having 7 to 18 carbon atoms.

Specific examples include 2,2,4-trimethylpentane (isooctane), n-nonane, n-decane,
Aliphatic hydrocarbons such as n-hexadecane, octadecane, eicosane, methylheptane, 2,2-dimethylhexane and 2-methyloctane; aromatic hydrocarbons such as benzene, toluene, xylene, cumene, naphthalene, anthracene and styrene; dodecyl Monohydric alcohols such as alcohol, octyl alcohol, n-octadecyl alcohol, 2-octanol and lauryl alcohol; polyhydric alcohols such as propylene glycol, triethylene glycol, tetraethylene glycol, glycerin, hexylene glycol, dipropylene glycol; benzyl alcohol , 4-hydroxytoluene, phenethyl alcohol, 1-naphthol, 2-naphthol, catechol, aromatic alcohols such as phenol; acetic acid, propionic acid, butyric acid, Prong acid, acrylic acid, crotonic acid, capric acid, stearic acid, aliphatic monocarboxylic acids such as oleic acid; oxalic acid, succinic acid, adipic acid, maleic acid, polyvalent aliphatic carboxylic acids such as glutaric acid;
Aromatic carboxylic acids such as benzoic acid, 2-methylbenzoic acid and 4-methylbenzoic acid; ethyl acetate, isobutyl acetate,
Aliphatic esters such as n-butyl acetate, methyl propionate, ethyl propionate, methyl butyrate, methyl acrylate, dimethyl oxalate, dimethyl succinate and methyl crotonate; and methyl benzoate and methyl 2-methylbenzoate Aromatic carboxylic esters; organic amines such as imidazole, triethanolamine, diethanolamine, cyclohexylamine, hexamethylenetetramine, triethylenetetramine, aniline, octylamine, aniline, and phenethylamine; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and benzophenone , Methoxybenzene, ethoxybenzene,
Examples include ethers such as methoxytoluene, lauryl methyl ether, and stearyl methyl ether, and amides such as stearyl amide, benzoyl amide, and acetamide.

Also, oils and fats such as linseed oil, soybean oil, poppy oil, safflower oil, etc., which are components of the printing ink, tributyl phosphate, tricresyl phosphate, dibutyl phthalate,
Plasticizers such as butyl laurate, dioctyl phthalate, and paraffin wax are also included.

In addition, organic solvents such as ethylene glycol monoethyl ether, cyclohexanone, methyl cellosolve, butyl cellosolve, cellosolve acetate, 1,4-dioxane, dimethylformamide and acrylonitrile having a boiling point in the above preferred range can also be used.

Preferred organosilicon compounds are organopolysiloxane compounds typified by dimethyl silicone oil, methylphenyl silicone oil and the like, especially organopolysiloxanes having a polymerization degree of 12 or less. These preferred organopolysiloxanes have one to two organic groups attached per siloxane bond unit,
The organic group includes an alkyl group and an alkoxy group having 1 to 18 carbon atoms, an alkenyl group and an alkynyl group having 2 to 18 carbon atoms, an aryl group having 6 to 18 carbon atoms, and a carbon atom having 7 to 18 carbon atoms.
An aralkyl group of 18 and an alicyclic group having 5 to 20 carbon atoms. Further, these organic substituents may be further substituted with a halogen atom, a carboxyl group, or a hydroxy group.
Further, the above-mentioned aryl group, aralkyl group and alicyclic group may be further substituted with a lower alkyl group such as a methyl group, an ethyl group or a propyl group within the above-mentioned carbon number range.

Specific examples of preferred organosilicon compounds that can be used in the present invention are the following compounds, but the present invention is not limited thereto.

Preferred polyorganosiloxanes include a dialkylsiloxane group having an alkyl group having 1 to 5 carbon atoms, a dialkoxysiloxane group having an alkoxy group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms and phenyl. A repeating unit containing at least one of an alkoxyphenylsiloxane group having a group and an ethoxymethoxysiloxane group or a methoxyethoxysiloxane group, and having a degree of polymerization of 2 to 12, more preferably 2
10 to 10 polyorganosiloxanes. The terminal group is an alkyl group having 1 to 5 carbon atoms, an amino group, a hydroxy group, a hydroxyalkyl group having 1 to 5 carbon atoms or an alkoxy group having 1 to 5 carbon atoms. More preferred terminal groups are methyl, ethyl, isopropyl, n-propyl, n-butyl, t-butyl, methoxy and ethoxy.

Among them, preferred siloxane compounds are
Dimethylpolysiloxane having a polymerization degree of 2 to 10, dimethylsiloxane having a polymerization degree of 2 to 10-methylphenylsiloxane copolymer, dimethylsiloxane having a polymerization degree of 2 to 8
A diphenylsiloxane copolymer, a dimethylsiloxane-monomethylsiloxane copolymer having a degree of polymerization of 2 to 8, and the terminal of these polysiloxane compounds is a trimethylsilane group. In addition, 1,3-bis (3-aminopropyl) tetramethyldisiloxane, 1,5-bis (3-aminopropyl) hexamethyltrisiloxane,
Dibutyl-1,1,3,3-tetramethyldisiloxane, 1,5-dibutyl-1,1,3,3,5,5-hexaethyltrisiloxane, 1,1,3,3,5,5- Hexaethyl-1,5-dichlorotrisiloxane, 3-
(3,3,3-trifluoropropyl) -1,1,3
3,5,5,5-heptamethyl-trisiloxane, decamethyltetrasiloxane and the like.

As particularly preferred siloxane compounds, there are commercially available so-called silicone oils, and dimethyl silicone oil (a commercially available product such as silicone KF96
(Manufactured by Shin-Etsu Chemical Co., Ltd.), methylphenyl silicone oil (commercially available, for example, silicone KF50 (manufactured by Shin-Etsu Chemical Co., Ltd.)), and methyl hydrogen silicone oil (commercially available, for example, silicone KF99 (Shin-Etsu Chemical Co., Ltd.) Co., Ltd.).

In addition, silane compounds such as n-decyltrimethoxysilane, n-decyltri-t-butoxysilane, n-octadecyltrimethoxysilane, n-octadecyltriethoxysilane and dimethoxydiethoxysilane can also be mentioned. .

Among the above organic compounds, particularly preferred compounds are silicone oil, fatty acids, glycerin esters and amides thereof, and aliphatic alcohols having 6 or more carbon atoms.

From another viewpoint, the organicity in the organic conceptual diagram is from 80 to 1200 (per polymer in the case of a polymer), preferably from 100 to 600, and the organic / inorganic ratio is from 0.1 to 600. Organic compounds falling within the range of 8 to infinity (that is, having an inorganic property of 0), preferably 1.0 to 10. For the concept of organic concept, see Yoshio Tanaka's “Organic concept” (Sankyo Shuppansha, first edition published in 1983).
It is detailed on the page. It is unknown why the organic compounds in the above range on the organic conceptual diagram have the effect of promoting hydrophobicity, but the compounds in this range have moderate polarity and are relatively organic compounds. Yes, its moderate polarity,
It is presumed that it provides an adsorption force to the printing original plate, and its relatively large organic property makes the adsorption surface of the printing original plate hydrophobic.

A preferred method for bringing the organic compound into contact with the surface of the printing plate is, in the case of a low-boiling organic compound, by providing a jacket for vapor aeration and placing the compound-filled container therein,
The vapor of the organic compound may be present in the mantle so that the printing plate in the mantle is exposed to the vapor. Further, paper, cloth, zeolite, diatomaceous earth, or the like impregnated with an organic compound may be inserted into the mantle.

When the organic compound is a liquid, a device for applying, spraying or dipping the liquid of the organic compound is provided in the above-mentioned mantle to bring the organic compound into direct contact with the surface of the printing original plate. In the case of a solid organic compound, a suitable organic solvent,
For example, methanol, acetone, benzol, 2, 2,
A liquid may be selected from 4-trimethylpentane or the above-mentioned preferred organic compound of the present invention, dissolved therein, and contacted as a solution by the above-described method.

Specific examples of the method of contacting these organic compounds with the original printing plate are shown in Examples.

Certain metals having high-temperature hydrophilicity, such as silicon and zinc, have the property of becoming hydrophobic when heated appropriately. The hydrophobic expression temperature is usually 50 to 250 ° C., which is lower than the hydrophilic expression temperature. Instead of the hydrophobic method in which an organic compound is present, a hydrophobic method in which heating is performed at a temperature at which hydrophobicity is exhibited may be used. In that case, an organic compound may be present to promote hydrophobicity.

The description of the method and operation of the hydrophobicization is completed above, and the next step, that is, the application of the hydrophilic region to the surface of the hydrophobicized printing plate by imagewise heating at a high temperature at which the hydrophilicity is developed, that is, Next, the image-forming hydrophilicity will be described. (Improving image-like hydrophilicity) A printing original plate made of a metal having high-temperature hydrophilicity-imparting properties is subjected to imagewise heating at a high-temperature hydrophilicity-imparting temperature to impart a hydrophilic region to a hydrophobic printing original plate surface. .

The heating means includes, for example, a solid-state laser emitting infrared light, a semiconductor laser emitting infrared or visible light, an infrared lamp, a xenon discharge lamp, and flash light generated by discharging from a large-capacity condenser. A light heating method such as a light / heat conversion drawing mechanism that emits light and a contact heating method such as a thermal recording head using a thermal melting type and sublimation type thermal dye transfer are used as the other.

In order to adjust the heating temperature to the range of the high-temperature hydrophilicity developing temperature, a method such as controlling the intensity of light used for heating or controlling the power supplied to the heating head for thermal recording is adopted. .

In the present invention, the temperature of the surface of the printing plate at the time of forming an image-like distribution on the surface of the printing plate must be higher than the hydrophobic expression temperature of a metal having high-temperature hydrophilicity. Although it depends on the physical properties of the metal having the high-temperature hydrophilic property, the hydrophobic property temperature is 50 to 300 ° C.
Is usually 100 to 300 ° C., preferably 15 to 300 ° C.
The range is 0 to 250 ° C.

The image heating by the light heating method may be any of a surface exposure method and a scanning method. In the former case, an infrared irradiation method or a method in which high-intensity short-time light from a xenon discharge lamp is irradiated onto a printing original plate through a mask image to generate heat by light-heat conversion. When a surface exposure light source such as an infrared lamp is used, the preferable exposure amount varies depending on the illuminance, but usually, the surface exposure intensity before being modulated with a print image is 0.1 to 10 J / cm ² . It is preferably in the range, more preferably in the range of 0.3 to 1 J / cm ² . When the support is transparent, exposure can be performed through the support and the mask image from the back side of the support. The exposure time is preferably selected so that the above-mentioned exposure intensity can be obtained by irradiation of 0.01 μsec to 10 msec, preferably 0.1 μsec to 1 msec. When the irradiation time is long, it is necessary to increase the exposure intensity due to the competition between the heat energy generation rate and the generated heat energy diffusion rate.

In the latter case, that is, in the case of the scanning system, a system is used in which an infrared laser light source is used to modulate a laser beam with an image and scan the original printing plate. Examples of the laser light source include a semiconductor laser, a gas laser, a helium cadmium laser, and a YAG laser having many components of near infrared rays and infrared rays. Irradiation can be performed with a laser having a laser output of 0.1 to 300 W. When a pulse laser is used, it is preferable to irradiate a laser having a peak output of 1000 W, preferably 2000 W. When the support is transparent, exposure can be performed through the support from the back side of the support.

When heating with light, for example, a light-to-heat conversion layer may be provided on a printing original plate, and the layer may absorb light energy to generate heat. Alternatively, it is also possible to heat the metal itself having high-temperature hydrophilicity characteristics by absorbing light and generating heat by itself.

Examples of the light-to-heat conversion layer include a layer containing carbon black, a cyan dye, a pyrylium dye, and the like.

In the contact heating method, any known contact-type thermal recording apparatus, for example, a thermal recording head of a thermal melting type and a sublimation type thermal dye transfer method is used. These include a method in which a single thermal recording element is driven two-dimensionally, a method in which an array of linearly arranged thermal recording elements is scanned in a perpendicular direction and drawing, or a high-speed drawing method using a two-dimensionally arranged recording element. A known thermal recording element can be used.

The second operation procedure of the printing method of the present invention has been described above.
The formation of the imagewise hydrophilic region, which is the stage, has been described. Since the image-wise distribution of the hydrophilic region and the hydrophobic region was formed by the operations of the first and second stages, printing can be performed as a printing plate also at this stage. In addition, a metal thin layer is further provided by adding the following steps after metal replacement to improve the ink receiving ability (that is, prevent ink smear) and the printing durability, which are the objects of the invention. is there. (Formation of imagewise thin metal layer) The third step is a step of forming a thin metal layer on a hydrophilic region on a printing plate in which hydrophobic regions and hydrophilic regions are formed imagewise. <Overview of Operation> An aqueous solution containing a metal having a lower ionization tendency than a metal having a high-temperature hydrophilicity developing property is brought into contact with the surface of a printing original plate having a distribution of hydrophobic and hydrophilic regions imagewise formed.

The contact method is not particularly limited as long as a metal substitution reaction takes place between a metal having a high-temperature hydrophilicity developing property in the hydrophilic region and a metal having a low ionization tendency. Any may be used.

The conditions of the metal substitution reaction are appropriately optimized, and the contact time of the aqueous solution is usually 3 hours at room temperature.
It is from 0 seconds to 10 minutes, preferably from 1 to 5 minutes. The temperature of the aqueous solution is usually 10 to 90 ° C., preferably 2 to 90 ° C.
The range is from 0 to 40 ° C. The thickness of the thin metal layer formed by the metal substitution reaction is usually 0.01 to 5 μm,
It is preferably about 1 μm.

Originally, the high-temperature hydrophilic region and the aqueous solution can be brought into contact with each other to replace the metal having a low ionization tendency with a metal, and the thin layer is formed on the surface of the printing original plate to be ink-receptive. On the other hand, even if the image-like hydrophobic area is in contact with the aqueous solution, the metal ion does not move and exchange reaction because it is hydrophobic, and remains as it is.

Therefore, when the hydrophobic region is subjected to a hydrophilic treatment by removing an organic compound in the next fourth step, this region is more hydrophilic than the substituted metal region.
Therefore, the ink becomes repellent.

The aqueous solution used for the contact treatment is as follows:
Any aqueous solution containing a water-soluble compound of a metal having a lower ionization tendency than the metal having high-temperature hydrophilicity constituting the printing plate may be used. As the water-soluble compound, preferred metal compounds include the following. . -A water-soluble compound suitable when the metal having high-temperature hydrophilicity constituting the printing original plate is aluminum cupric ion, cuprous ion, silver ion, stannic ion, stannous ion, hexavalent chromium Aqueous compounds containing ions such as ions, trivalent chromium ions and the like, for example, hydrochlorides and salts thereof, such as halogenates, nitrates, sulfates, oxalates, aminopolycarboxylic acid complexes, ammonia complexes, amine complexes and the like. But more preferably cupric chloride and sulfuric acid
Copper, cuprous chloride, copper (II) ammonia complex, copper (I
I) EDTA complex, copper (II) PDTA complex, silver nitrate,
Silver ammonia complex salts and the like can be mentioned. -A water-soluble compound suitable when the metal having high-temperature hydrophilicity constituting the printing plate is iron (including SUS) Aqueous solution compound containing ions such as cupric ion, cuprous ion and silver ion, for example, , Hydrochlorides and other halogenates (complexes in the case of silver ions), nitrates, sulfates, ammonia complexes, amine complexes, and the like. More preferred are cupric chloride, cupric sulfate, and chloride. Copper (I), copper (II)
Ammonia complex, copper (II) EDTA complex, copper (II)
PDTA complex salts, silver nitrate, silver ammonia complex salts, silver / ethylenediamine complex salts and the like are exemplified. -A water-soluble compound suitable when the metal having high-temperature hydrophilicity constituting the printing plate is copper is exemplified by silver nitrate, silver ammonia complex salt, silver / ethylenediamine complex salt and the like.

The metal concentration of the water-soluble compound varies depending on the metal having a high-temperature hydrophilicity-expressing property of the metal and the printing plate, the coexisting components of the aqueous solution, and the pH. Mol / liter, preferably 0.1 to
It is appropriately selected from 5 mol / l, more preferably 0.1 to 3 mol / l.

A preferred combination of a metal having the property of exhibiting high-temperature hydrophilicity (the former described below) and a water-soluble compound of a metal having a lower ionization tendency (the latter described below) is as follows.
Copper chloride, silver nitrate and tin chloride for aluminum; copper chloride, silver nitrate and tin chloride for zinc; copper chloride and silver nitrate for iron; silver nitrate for copper.

An aqueous solution containing a metal water-soluble compound having a low ionization tendency may be used to stabilize the water-soluble compound, adjust the pH to an appropriate value, maintain the pH value of the solution in a buffer, or the like. Various substances may be included for various purposes, for example, sulfuric acid, phosphoric acid, boric acid, nitric acid, hydrochloric acid,
Acids such as oxalic acid, formic acid, acetic acid, citric acid, tartaric acid, carbonic acid,
And alkali metal salts and ammonium salts thereof. Specific examples thereof include calcium hydroxide, magnesium hydroxide, sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, ammonium hydroxide, ammonium carbonate, and phosphorus. Examples thereof include trisodium acid, sodium dihydrogen phosphate, disodium hydrogen phosphate, tripotassium phosphate, potassium dihydrogen phosphate, dipotassium hydrogen phosphate, borax, sodium metaborate, and potassium metaborate. In addition, alkalis such as water-soluble amines, ammonium hydroxide, sodium hydroxide, and potassium hydroxide are exemplified.

Further, a complexing agent can be added as needed for accelerating the metal substitution reaction. Preferred complexing agents include aminopolycarboxylic acids, amines, hydroxycarboxylic acids, polycarboxylic acids, thiocyanates,
Examples thereof include halogen acids.

Among the above complexing agents, preferred aminopolycarboxylic acids include, for example, ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid, cis-cyclohexanediaminetetraacetic acid, ethylenediamine-N, N'-disuccinic acid, ethylenediamine-N , N'-Diglutamic acid,
Ethylenediamine-N, N'-dimalonic acid, 1,3-propylenediamine-N, N'-disuccinic acid, 1,3-propylenediamine-N, N'-dimalonic acid, N, N'-di (carboxylate ) -L-Glutamic acid, transsilohexanediaminetetraacetic acid, 1,2-diaminopropanetetraacetic acid, 1,4-butylenediaminetetraacetic acid, o-xylenediaminetetraacetic acid, ethylenediamine-N, N'-bis-orthohydroxyphenyl Acetic acid, diethylenethioetherdiaminetetraacetic acid, N, N'-bis (2-hydroxybenzyl) ethylenediamine-N, N'-diacetic acid, ethylenediamine-N, N'-di (2-acetamido) diacetic acid, and the like, Monoamino polycarboxylates include iminodiacetic acid, methyliminodiacetic acid, β-alanine diacetate, nitrilotriacetic acid and the like. It is.

Particularly preferred complex salts are ethylenediaminetetraacetic acid, ethylenediamine-N, N'-disuccinic acid and ethylenediamine-N, N'-diglutamic acid.

These aminopolycarboxylates may be used in combination of two or more as necessary.

In the present specification, the description of aminopolycarboxylic acid does not describe the form of a salt of a carboxyl group in the molecule, but in any case, the carboxyl group has an alkali metal salt, an ammonium salt or a salt thereof. Any of the non-salt forms in which the hydrogen atom remains as it is may be used. Therefore, the description of the form of these salts is omitted in the following description.

The preferred concentration of the aminopolycarboxylate in the aqueous solution depends on the combination of the metal of interest.
Preferably 0.01 to 1.5 mol per liter of aqueous solution,
More preferably, it is 0.05 to 1.0 mol, particularly preferably 0.10 to 0.5 mol.

An aminopolycarboxylic acid is obtained by reacting an amino acid with a dihaloalkane. For example, the reaction of aspartic acid with dibromoalkane to obtain ethylenediamine disuccinic acid JANeal, Inorganic Chemistry, v
ol. 7 (11), 2405, the method described in WO 96-01803 in which dichloroethane and aspartic acid are reacted in the presence of an alkali metal hydroxide, in the presence of an alkali metal hydroxide and an alkali metal bromide. To react dichloroethane with aspartic acid by the method described in JP-A-10-175930. The (S, S) form of ethylenediaminedisuccinic acid and ethylenediaminediglutamic acid can be prepared by the above synthesis method using L-succinic acid or L-glutamic acid as a starting amino acid, for example, the method described in JP-A-10-175930. Can be used to synthesize.

In the above complexing agents, the amines include aliphatic primary amines such as ethylenediamine, octylamine and ethanolamine, and aliphatic secondary amines such as triethylenetetramine, tetraethylenepentamine and the like. Examples thereof include didipropylamine and diethanolamine, and further include triethanolamine and imidazole. Examples of imidazole include 1-methylimidazole, 2-methylimidazole, 4- (2-aminoethyl) imidazole, 2- (2-hydroxyethyl) imidazole, 2-ethylimidazole, 4-propylimidazole, imidazole and the like.

The hydroxycarboxylic acid and polycarboxylic acid used in the complexing agent may include the following hydroxycarboxylic acids and polycarboxylic acids. Specific examples of polycarboxylic acids include glycolic acid,
Citric acid, tartaric acid, glyceric acid, lactic acid, succinic acid, maleic acid. These may be used in combination of two or more compounds.

If necessary, other compounds such as known interfaces such as 1,5-naphthalenedisulfonic acid, 1,4-butynediol, saccharin, ethylene cyanohydrin, glucose, dextrin, thiourea and derivatives thereof, and triethanolamine. Activators and leveling agents can also be added.

The concentration of the above amines is about the same as that of aminopolycarboxylic acids, and other compounds are about half or less. (Hydrophilization of Hydrophobic Area) The third step in which the image-wise formation of a thin metal layer is performed in the hydrophilic area on the original printing plate in accordance with the selective metal replacement has been described above. Next, in the fourth stage, that is, in the third stage, a description will be given of the process of making the hydrophobic region (hereinafter also referred to as “non-substituted region”) hydrophilic in which the metal substitution has not been performed.

Since this unsubstituted region remains hydrophobic in the first step, it must be converted to hydrophilic, and this conversion is performed in the fourth step.

In the third stage, two kinds of metals, a metal forming a thin metal layer in a metal-substituted hydrophilic region (hereinafter also referred to as a “metal-substituted region”) and a metal in a non-substituted region, are used. Of these, the relatively hydrophobic side is the ink-accepting region, but the metal having a low ionization tendency that forms the thin metal layer is more hydrophobic than the metal in the non-substituted region and becomes ink-receptive. However, since this non-substituted region is a hydrophobic region, it is necessary to perform a hydrophilic treatment.

That is, in the fourth step, the area which has been rendered hydrophobic in the first step is made hydrophilic by any means of washing and removing the organic compound and heating to a high-temperature hydrophilicity-expressing temperature, and the ink repellency is improved. It is a stage to do.

Hydrophobicization by washing is carried out with water, methanol,
A method of washing the hydrophobic region with a mixed solution of water, a mixed solution of methanol, acetone and water, or the like to remove a layer of an organic compound presumably present on the surface can also be used. However, the organic / inorganic mixed aqueous solution used for this purpose must be a sufficiently water-soluble organic liquid which does not itself have a hydrophobizing effect.

The hydrophilicization by heating to a high-temperature hydrophilicity-expressing temperature is basically the same as the hydrophilicity-imparting means used in the second stage, except that the hydrophilic region is imaged in the second stage. However, at this stage, it is only necessary to make the non-substituted region uniformly hydrophilic. Therefore, it is easy to perform the entire surface heating to a high-temperature hydrophilic expression temperature by an infrared lamp or electric heating. It is. The reason that the hydrophobic region of the printing original plate changes to hydrophilic by this heating is that the organic component adsorbed on the surface and contributing to the hydrophobicity is desorbed or decomposed by the excitation of the molecular vibration level by heating. It is estimated that.

By the operation of the fourth step, the non-substituted area which has been made hydrophobic for metal replacement while being an area on the original printing plate to receive the dampening solution is restored to its original hydrophilicity. In addition, the metal-substituted region has a high physical strength, and in many cases, a printing plate having a high discriminating ability from the recovered hydrophilic non-substituted region is formed.

After this stage, the printing original plate can be sent to the next printing step. [Printing] The non-image portion (that is, the non-substituted region) of the lithographic printing plate prepared by the above-described processing is sufficiently hydrophilic, but may contain washing water, a surfactant, and the like, if desired. A post-treatment may be performed with a rinse solution, a desensitizing solution containing gum arabic or a starch derivative. As the post-processing when the printing original plate processed according to the present invention is used as a printing plate material, these processings can be used in various combinations.

[0112] As a method for this, a sponge or absorbent cotton impregnated with the surface conditioning liquid is applied onto a lithographic printing plate,
A method in which a printing plate is immersed in a vat filled with a surface-conditioning solution and applied, or an automatic coater is used. Further, it is more preferable that the application amount is made uniform by using a squeegee or a squeegee roller after the application. The application amount of the surface conditioning liquid is generally 0.03 to
0.8 g / m ² (dry weight) is appropriate.

The lithographic printing plate obtained by such a process is applied to an offset printing press or the like, or is processed on a printing plate by processing a printing plate according to the present invention, and is used for printing a large number of sheets.

As described above, the printing method of the present invention has advantages such as high discrimination between hydrophilicity and hydrophobicity, and improved durability of the printing plate. . As a result, a printing plate excellent in printing quality and printing durability can be easily manufactured with good reproducibility.

[0115]

EXAMPLES Examples of the present invention will be described below, but the present invention is not limited to these examples. [Example 1] Copper was added to 99.5% by weight of aluminum in the presence of copper.
A 0.30 mm thick JISA1050 aluminum sheet containing 01% by weight, 0.03% by weight of titanium, 0.3% by weight of iron, and 0.1% by weight of silicon is 400 mesh pumice stone (manufactured by Kyoritsu Ceramics) The surface was sand-grained using a 20% by weight aqueous suspension and a rotating nylon brush (6,10-nylon), and then thoroughly washed with water.

This was immersed in a 15% by weight aqueous sodium hydroxide solution (containing 4.5% by weight of aluminum) and etched so that the amount of aluminum dissolved was 5 g / m ² .
It was washed with running water. Further, the mixture was neutralized with 1% by weight of nitric acid, and then, in an aqueous solution of 0.7% by weight of nitric acid (containing 0.5% by weight of aluminum), the voltage at the time of anode was 10.5 volts and the voltage at the time of cathode was 9.
3 volt square wave alternating waveform voltage (current ratio r = 0.90,
The electrolytic surface roughening treatment was carried out at an anode charge of 160 clones / dm ² using the current waveform described in Examples of JP-B-58-5796. After washing with water, it was immersed in a 10% by weight aqueous solution of sodium hydroxide at 35 ° C., etched so that the amount of aluminum dissolved was 1 g / m ² , and then washed with water. Next, it was immersed in a 30% by weight aqueous sulfuric acid solution at 50 ° C., desmutted, and washed with water.

Further, a porous anodic oxide film forming treatment was carried out in a 20% by weight aqueous sulfuric acid solution (containing 0.8% by weight of aluminum) at 35 ° C. using a direct current. That is, electrolysis was performed at a current density of 13 A / dm ² , and the anodic oxide film weight was adjusted to 2.7 g / m ² by adjusting the electrolysis time.

After the support was washed with water, it was immersed in a 3% by weight aqueous solution of sodium silicate at 70 ° C. for 30 seconds, washed with water and dried.

The aluminum support obtained as described above had a reflection density of 0.30 and a center line average roughness of 0.58 μm as measured by a Macbeth RD920 reflection densitometer.

This was wound around the substrate of the plate cylinder 1 shown in FIG. 1 to obtain a printing original plate for on-press printing.

Subsequently, the printing plate was subjected to a hydrophobic treatment.

FIG. 1 shows a hydrophobizing unit used in the present embodiment, in which a liquid organic compound or a solution in which an organic compound is dissolved is applied to the surface of a printing original plate wound around a plate cylinder 1. This is a hydrophobizing unit assembled to form a coating film of an organic compound. Inside the mantle 40 of the processing unit, a container 41 filled with the organic compound liquid 27, a dip roller 42 whose lower part is immersed in the liquid filled in the container to attach and remove the liquid, and oppose the dip roller Reverse roller 43, reverse roller 4 for receiving an appropriate amount of the taken-out liquid
3 comprises a coating roller 44 for transferring the liquid adhering to 3 and transferring it onto the surface of the printing original plate. The surface of each roller is provided with a liquid-absorbing coating so that an appropriate amount of liquid can be held.

The container 41 for an organic compound shown in FIG. 1 is filled with benzylamine (organic 140, inorganic 85 in the organic conceptual diagram) as the organic compound liquid 27, and the thickness of the liquid film is reduced to 0.1 by a coating roller. Benzylamine was applied to the surface of the printing plate under the condition of micron size to form a hydrophobic surface. Contact Angle Meter CA-D (Kyowa Interface Science Co., Ltd.)
The contact angle of the surface with water was measured by the aerial water drop method using the method described in U.S. Pat.

Next, a 150 μm thick sialon wear-resistant protective layer was provided on the Ta—SiO 2 heating resistor in the high-temperature thermal recording section.
Using a heating element array in which thermal heads of x150 μm were arranged at intervals of 250 μm, the prints were heated by bringing them into contact with the surface of the original printing plate. The used thermal head is 2ms
The temperature reaches 220 ° C. by ec current supply and reaches 490 ° C. by 5 msec current supply. However, when the surface of the anodic oxide film having low thermal conductivity is continuously energized while scanning at 2.5 m / sec, the surface becomes almost 480 °. It was confirmed that the temperature was maintained at C by separately performing temperature measurement. The recording speed is 2.5m /
sec. The contact angle of the printing plate surface to water after printing with the thermal head
r The contact angle of the surface with water was measured by CA-D (manufactured by Kyowa Interface Science Co., Ltd.) by the aerial water droplet method.

Next, aqueous solutions (a) to (d) of the following composition containing a water-soluble compound of a metal having a lower ionization tendency than aluminum, which is a metal having a high-temperature hydrophilicity-imparting property, were prepared on the printing plate. By contacting with a device having the same coating function as the device shown in FIG. 1, a metal replacement reaction was performed on the printed portion at room temperature for 2 to 4 minutes.

Aqueous solution (a) (composition (g / l)) AgNO ₃ 21.6 EDTA · 4Na 30 NaNO ₃ 15 temperature (° C.): 20-30 aqueous solution (b) (composition (g / l)) AgNO ₃ 36 NaNO ₃ 15 temperature (° C.): 20 to 30 aqueous solution (c) (composition (g / l)) CuSO ₄ .5H ₂ O 200 H ₂ SO ₄ 50 temperature (° C.): 25 to 50 aqueous solution (d) (composition ( g / l)) CuSO ₄ 200 ammonia water (12N) 50ml After the above-mentioned contact treatment for carrying out the metal substitution reaction, the aqueous solution is flowed off, and the surface of the printing original plate is mixed with a 5N methanol / water mixed solution of 0.05N hydrochloric acid. Was washed. After cleaning, the contact angle of the unsubstituted portion of the printing plate
When the contact angle of the surface with water was measured by an e-water drop method using e Meter CA-D (manufactured by Kyowa Interface Science Co., Ltd.),
It was between 10 degrees, indicating that washing restored hydrophilicity.

The plate cylinder is used for a single-sided printing machine of Oliver 52 manufactured by Sakurai Co., Ltd., and the dampening water is supplied to the ink / fountain solution supply section 3 by pure water and the ink is supplied by New Japan Ink Chemical Industry Co., Ltd.
Offset printing was performed on 5000 sheets using ampion F gloss 85 ink. A printing surface was formed in which the ink was received in the metal-substituted area and the dampening solution was received in the non-substituted area, and a clear print was obtained from the start to the end, and no damage to the plate cylinder was observed. [Example 2] Iron was used in place of aluminum of the printing original plate used in Example 1, and as an aqueous solution,
Except for using the aqueous solution (a), the aqueous solution (b) or the following aqueous solution (e), the same processing as in Example 1 was performed to prepare a printing plate, and printing was performed in the same manner as in Example 1. The result was obtained.

Aqueous solution (e) (composition (g / l)) CuSO ₄ 70 H ₂ SO ₄ (1N) 5 ml EDTA · 4Na 15 sodium citrate 5 pH: 3.5, temperature (° C.): 40-70 Example 3] A printing plate was prepared in the same manner as in Example 2 except that SUS was used in place of iron of the printing plate used in Example 2 and the aqueous solution (c) was used as the aqueous solution. When printing was performed in the same manner, the same results as in Example 1 were obtained. Example 4 A printing plate was prepared in the same manner as in Example 3, except that zinc was used in place of SUS of the printing plate used in Example 3 and aqueous solution (f) was used as the aqueous solution. And
When printing was performed in the same manner, the same result as in Example 1 was obtained.

Aqueous solution (f) (composition (g / l)) AgNO ₃ 22 aqueous ammonia (12N) 40 ml gelatin 1 g

[0130]

According to the present invention, the surface of a printing original plate having a metal having the property of exhibiting high-temperature hydrophilicity of the present invention as an image forming layer is made hydrophobic, and the surface is heated imagewise at a high-temperature hydrophilicity-presenting temperature to obtain hydrophilicity. Form an imagewise distribution of hydrophobicity, and use an aqueous solution containing a metal that has a lower ionization tendency than a metal with high-temperature hydrophilicity to form a thin metal layer imagewise on the original printing plate by a metal substitution reaction. The printing method of creating a printing plate does not require processing such as development, and can directly create a printing plate.After printing is completed, remove the ink from the printing plate and regenerate the printing plate to repeat. Can be used.
In this method, since the mechanical strength of the printing plate is enhanced by the thin metal layer, both printing quality and printing durability can be improved.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of one embodiment of a hydrophobic treatment unit provided with a supply and application unit of an organic compound.

FIG. 2 is a diagram showing a configuration of one embodiment of a hydrophobic treatment unit provided with a means for supplying and applying an organic compound vapor.

[Explanation of symbols]

 Reference Signs List 1 plate cylinder 2 hydrophobizing unit 24 air intake 25 cock 26 evaporation chamber 27 organic compound 29 organic compound supply means 30 electric heater 32 temperature sensor 33 temperature sensor 34 temperature control unit 40 jacket 41 container 42 dip roller 43 reverse roller 44 Coating roller

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takashi Nakamura 798, Miyadai, Kaisei-cho, Ashigara-gun, Kanagawa Prefecture F-Term (in reference) 2H084 AA13 AA32 BB02 BB16 CC05 2H096 AA06 BA13 DA01 DA04 EA04 FA05 FA10 GA60 2H114 AA04 AA22 AA24 BA05 DA04 DA08 DA73 DA78 EA01 EA03 FA16 GA09 GA22

Claims (1)

[Claims] 1. A printing plate having a metal having a high-temperature hydrophilicity developing property on its surface is brought into contact with an organic compound or heated to a hydrophobicity developing temperature to make the printing plate surface hydrophobic, The surface is heated imagewise at a high hydrophilicity-expressing temperature to change the heated portion to be hydrophilic, thereby forming an image-like distribution of a hydrophobic region and a hydrophilic region, on a printing plate having the image-like distribution. Contacting an aqueous solution containing a water-soluble compound of a metal having a lower ionization tendency than at least the metal having the high-temperature hydrophilicity-developing property, and by the metal replacement, the ionization tendency is low in the hydrophilic region on the printing original plate. A thin metal layer of metal was formed imagewise, and the hydrophobic area was subjected to a hydrophilic treatment, and the printing plate was brought into contact with ink to receive the ink in the area having the thin metal layer. To form a printing surface, an offset printing method and performing printing.