JP3756664B2 - Method for producing support for lithographic printing plate - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing a lithographic printing plate support. In particular, the present invention relates to a method for producing a negative lithographic printing plate support capable of direct plate making using a photopolymerizable composition having high sensitivity to light in the visible light region and good tone reproducibility.
[0002]
[Prior art]
Conventionally, negative lithographic printing plates are widely known, and there are various types of photosensitive layers. For example, there are a diazo resin-containing type, a photopolymerization type, a photocrosslinking type, and the like. In order to prepare such a lithographic printing plate, it is common to place a transparent negative film manuscript (lith film) on these lithographic printing plates and to expose the image using ultraviolet rays. There was a gap between hands.
[0003]
In recent years, with the development of image forming technology, a photopolymer having high photosensitivity to light in the visible region has been demanded. For example, it is a photosensitive material suitable for non-contact type projection exposure plate making, visible light laser plate making and the like, and a photopolymerization system is most promising because of its highest sensitivity. As the visible light laser, 488 and 514.5 nm light of Ar laser, second harmonic light (SHG-LD, 350 to 600 nm) of semiconductor laser, 532 nm light of SHG-YAG laser, and the like are promising.
[0004]
Therefore, by using a kind of high-sensitivity photopolymerizable photosensitive layer in the photosensitive layer, a laser beam with a narrow beam focused is scanned on the plate surface, and a character document, an image document, etc. are directly formed on the plate surface. Direct plate-making is possible without using a manuscript. For example, by using the photosensitive composition described in JP-B-61-9621, JP-A-63-17805, JP-A-2-244050, etc., direct plate-making is possible without using a film original.
[0005]
However, since such conventional high-sensitivity photopolymerizable printing plates do not necessarily have a strong adhesion between the photosensitive layer and the support, solid images may be lost or fine lines or highlight areas may be lost when used for printing large numbers at high speed. This causes a problem of flying.
[0006]
Therefore, in the high-sensitivity photopolymerization system, the adhesiveness between the support and the photosensitive layer is an important factor, and many studies and developments have been made.
[0007]
For example, in Japanese Patent Application Laid-Open No. 7-159983, a functional group capable of causing an addition reaction due to radicals is planted on the surface of a support by a covalent bond so as to have an adhesive force with the photopolymerizable photosensitive layer.
[0008]
In order to further strengthen the adhesion between the photosensitive layer and the support, it is known to use a phosphoric acid anodized film as a surface treatment of the support for the purpose of enhancing the anchor effect of the photosensitive layer. Certainly, this method improves highlight adhesion, but at the same time, removes ink (the number of lost paper until the ink is completely removed when the ink on the non-image area is removed during printing). There is a fault that deteriorates.
[0009]
On the other hand, it is also conceivable to roughen the rough surface of the support. Certainly, this improves the adhesion and improves the durability of the image. However, on the other hand, it is easy to be affected by abrasion of the photosensitive layer at the time of printing, and the hydrophilic surface of aluminum tends to appear on the surface, resulting in a defective printed matter, or the hydrophilicity of the non-image area is lowered, and the printing is stained. Result.
[0010]
If stains occur during printing, the plate surface is wiped with a plate cleaner on the printing machine to remove the ink. If the adhesion between the photosensitive layer and the support is weak, there is no problem with the alkaline plate cleaner, but there is a problem that the highlight part will fly off with the acidic plate cleaner. Therefore, several kinds of plate cleaners for printing had to be prepared depending on the printing plate used by the user. Further, when the number of printed sheets is large, there is a problem that if the adhesive force between the photosensitive layer and the support is weak, fine lines and highlights gradually fly as in the case where the plate surface is wiped with an acidic plate cleaner.
[0011]
However, as a recent market trend, there is a strong demand for shortening the exposure time for improving productivity and for using the laser at a low output for extending the life of the laser. High sensitivity is an eternal issue. However, the adhesive strength between the photosensitive layer and the support is sufficiently exerted, and even if the printing plate surface is wiped with a plate cleaner or the like or even when printing several hundred thousand sheets, the tone reproducibility is the same as the printed matter at the start, and A further highly sensitive photopolymerizable lithographic printing plate that was not soiled was in a very difficult situation.
[0012]
[Problems to be solved by the invention]
Therefore, the present invention is more sensitive due to the adhesion between the strong photosensitive layer and the support, and even if the ink on the printing plate is removed with an acid plate cleaner or a large amount of printing is performed, fine lines and highlights do not fly, An object of the present invention is to provide a method for producing a support for a negative photopolymerizable lithographic printing plate which is excellent in printing durability and can be directly laser-written without being stained.
[0013]
[Means for Solving the Problems]
As a result of diligent research to solve the above problems, the inventor has roughened the aluminum plate and anodized the surface as the first stage, and then the micropores of the first stage anodized film as the second stage. This object can be achieved by the method for producing a lithographic printing plate support by anodizing again under the condition that the pore diameter is reduced.
[0014]
The purpose of this is to make the first stage anodization treatment with a sulfuric acid bath by making the amount of the first stage anodized film equal to or less than the amount of the second stage film. The film is dissolved by treating with an alkaline aqueous solution to expand the micropores present in the film, and then the second stage anodizing treatment is performed with a sulfuric acid bath, and the first stage is a phosphoric acid bath or oxalic acid bath. It can be more preferably achieved by the anodizing treatment according to, and the second step being anodizing treatment with a sulfuric acid bath.
[0015]
The lithographic printing plate support obtained in this way has a lithographic printing plate obtained by forming a photosensitive layer capable of forming an image directly on the plate surface by laser beam scanning without using a film original, without causing deterioration of ink removal. The adhesiveness of the photosensitive layer can be improved.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail.
[0017]
[Aluminum support]
The aluminum support used in the present invention is a metal mainly composed of dimensionally stable aluminum and is made of aluminum or an aluminum alloy. In addition to a pure aluminum plate, an alloy plate containing aluminum as a main component and containing a trace amount of foreign elements, or a plastic film or paper laminated or vapor-deposited with aluminum (alloy) is selected. Furthermore, a composite sheet in which an aluminum sheet is bonded to a polyethylene terephthalate film as described in Japanese Patent Publication No. 48-18327 may be used.
[0018]
In the following description, the above-described plates made of aluminum or aluminum alloy are collectively referred to as aluminum plates. The foreign elements contained in the aluminum alloy include silicon, iron, manganese, copper, magnesium, chromium, zinc, bismuth, nickel, titanium, etc., and the content of the foreign elements in the alloy is 10% by weight or less. In the present invention, a pure aluminum plate is suitable. However, since pure aluminum is difficult to manufacture in terms of smelting technology, it may contain a slightly different element. Thus, the composition of the aluminum plate applied to the present invention is not specified, and conventionally known and used materials such as JIS A 1050, JIS A 1100, JIS A 3103, JIS A 3005, etc. It can be used as appropriate.
[0019]
Further, the aluminum plate used in the present invention is usually processed while continuously running in a web shape, and the width is about 400 mm to 2000 mm, and the thickness is about 0.1 mm to 0.6 mm. The thickness can be changed as appropriate according to the size of the printing press, the size of the printing plate, and the desire of the user.
[0020]
The aluminum plate is appropriately subjected to substrate surface treatment described later.
[0021]
[Graining process]
Examples of the graining method include mechanical graining, chemical etching, and electrolytic grain as disclosed in JP-A-56-28893. Furthermore, electrochemical graining method that electrochemically grains in hydrochloric acid or nitric acid electrolyte, and wire brush grain method that scratches aluminum surface with metal wire, and ball grain method that graines aluminum surface with abrasive balls and abrasives Further, a mechanical graining method such as a brush grain method in which the surface is grained with a nylon brush and an abrasive can be used, and the above graining methods can be used alone or in combination.
[0022]
Among them, the method of making the surface roughness usefully used in the present invention is an electrochemical method of graining chemically in a hydrochloric acid or nitric acid electrolyte, and a suitable amount of electricity is 50 to 400 C / dm.², Preferably 100 to 300 C / dm²Range. More specifically, in an electrolytic solution containing 0.01 to 50 wt%, preferably 0.5 to 10 wt% hydrochloric acid or nitric acid, the temperature is 20 to 100 ° C, preferably 30 to 70 ° C, and the time is 1 second to 1 second. 30 minutes, preferably 2 seconds to 1 minute, current density 100 to 400 A / dm², Preferably 10-50A / dm²It is preferable to perform electrolysis under these conditions.
[0023]
The grained aluminum plate is chemically etched with acid or alkali. When an acid is used as an etching agent, it takes time to destroy the fine structure, which is disadvantageous when the present invention is applied industrially, but it can be improved by using an alkali as the etching agent.
[0024]
As the alkali agent suitably used in the present invention, caustic soda, sodium carbonate, sodium aluminate, sodium metasilicate, sodium phosphate, potassium hydroxide, lithium hydroxide, and the like, and preferred ranges of concentration and temperature are 1 to 50 respectively. % By weight, especially 2 to 20% by weight, 20 to 100 ° C., particularly 30 to 70 ° C., and the amount of dissolved Al is 0.1 to 20 g / m², Especially 0.3-2g / m²The conditions are as follows.
[0025]
Pickling is performed to remove dirt (smut) remaining on the surface after etching. As the acid used, nitric acid, sulfuric acid, phosphoric acid, chromic acid, hydrofluoric acid, borohydrofluoric acid and the like are used. In particular, as a method for removing smut after the electrochemical surface roughening treatment, contact with 15 to 65% by weight sulfuric acid at a temperature of 50 to 90 ° C. as described in JP-A-53-12739 is preferable. And the alkali etching method described in Japanese Patent Publication No. 48-28123.
[0026]
[First stage anodizing]
The aluminum plate treated as described above is subjected to anodizing treatment. The anodizing treatment can be performed by a method conventionally used in this field. Specifically, an aqueous solution of sulfuric acid, phosphoric acid, oxalic acid or the like is mainly used as an electrolytic bath. In some cases, chromic acid, sulfamic acid, benzenesulfonic acid and the like, or an aqueous solution or a non-aqueous solution combining two or more of these may be used. When direct current or alternating current is applied to aluminum in the electrolytic bath as described above, an anodized film can be formed on the surface of the aluminum support.
[0027]
The conditions for anodizing treatment vary depending on the electrolyte used, and thus cannot be determined unconditionally. In general, however, the concentration of the electrolyte is 1 to 80% by weight, preferably 5 to 20%, and the solution temperature is 5 to 5. 70 ° C, preferably 10-60 ° C, current density 0.5-60 A / dm², Preferably 1-30 A / dm²A voltage of 1 to 100 V, preferably 5 to 50 V, and an electrolysis time of 1 to 100 seconds, preferably 5 to 60 seconds are appropriate.
[0028]
Among these anodizing treatments, a method for anodizing at a high current density in sulfuric acid and U.S. Pat. No. 3,511,661, particularly described in British Patent 1,412,768. A method of anodizing the described phosphoric acid as an electrolytic bath is preferred.
[0029]
In the present invention, the first stage anodized film is 0.1 to 5 g / m.²Preferably 0.2 to 2 g / m²It is. Many dents (pores) are formed on the surface of the anodized film. This pore is 10^Five-10⁷Piece / mm²The depth is about 0.1 to 2 μm. The average pore diameter is about 1 to 50 nm, usually about 4 to 20 nm.
[0030]
After the first stage anodizing treatment, the micropores can be expanded by alkali treatment in some cases. The alkali treatment condition is 0.1 to 0.5 g / m of the first stage micropore with an aqueous solution of pH 11 to 13.²Any conditions can be used as long as they can be dissolved. For example, after adjusting to pH = 11-13 with sodium hydroxide, potassium hydroxide, lithium hydroxide or the like, 10 to 70 ° C., preferably 20 to 50 ° C., 1 to 300 It is appropriate to process for 2 seconds, preferably 5 to 100 seconds. At this time, the alkali treatment liquid may contain a metal salt of a polyvalent weak acid such as carbonate, borate or phosphate. The diameter of the micropores expanded by this treatment is about 5 to 200 nm on average, usually about 10 to 100 nm. The diameter of the micropore in the first stage, which serves as a reference in the second stage, is washed with water after alkali treatment.
[0031]
[Second stage anodizing treatment]
After the alkali treatment as described above or without the alkali treatment, the second stage anodizing treatment is performed. The type, concentration, liquid temperature, current density, voltage, electrolysis time, etc. of the electrolytic bath may be basically the same as in the first stage, but the micropore diameter of the anodized film formed in the second stage is the first. The conditions are smaller than those of the stage. That is, the pore diameter is decreased by increasing the concentration and liquid temperature of the electrolytic bath and decreasing the current density. This is because if the micropores in the second stage are larger than the micropores in the first stage, there is a problem that the non-image area is easily smeared during printing. Many pores are also formed in the oxide film in the second stage. The number of pores is 10^Five-10⁷Piece / mm²The depth is about 0.2 to 5 μm. The diameter of the micropore is preferably about 80% to 5%, particularly about 60% to 10% of the diameter of the first stage micropore. Further, since the adhesion improvement effect is lost when the amount of the first stage film is larger than the amount of the second stage film, the amount of the first stage film is equal to or less than the amount of the second stage film. It is preferable that the coating amount at the stage is equal to or more than the coating amount at the first stage. A preferable amount of the film in the second stage is about 1 to 100 times, particularly about 1 to 10 times that of the first stage.
[0032]
In addition, the total amount of the anodic oxide film including the first stage and the second stage is 0.5 to 10 g / m.², Preferably 1 to 5 g / m²It is. Then, it is washed with water and dried by hot air (50 to 200 ° C.) or a cold air natural drying method.
[0033]
An adhesive layer described later may be provided on the support formed as described above, if necessary. Thereafter, a photopolymerizable lithographic printing plate targeted by the present invention is formed by forming a photosensitive layer made of a photopolymerizable composition, which will be described later. An adhesive layer is formed before coating the photosensitive layer. In this case, an organic undercoat layer may be provided as necessary before or after the formation of the adhesive layer. Water-soluble resins such as polyvinyl phosphonic acid, polymers and copolymers having sulfonic acid groups in the side chain, polyacrylic acid, water-soluble metal salts (for example, zinc borate) or yellow dyes, amine salts, etc. Is also suitable.
[0034]
Examples of the organic compound used in the organic undercoat layer include phosphonic acids having an amino group such as carboxymethylcellulose, dextrin, gum arabic, 2-aminoethylphosphonic acid, phenylphosphonic acid optionally having a substituent, Organic phosphonic acids such as naphthyl phosphonic acid, alkyl phosphonic acid, glycero phosphonic acid, methylene diphosphonic acid and ethylene diphosphonic acid, organic such as phenyl phosphoric acid, naphthyl phosphoric acid, alkyl phosphoric acid and glycerophosphonic acid which may have a substituent Phosphoric acid, optionally substituted phenylphosphinic acid, naphthylphosphinic acid, alkylphosphinic acid and organic phosphinic acids such as glycerophosphinic acid, amino acids such as glycine and β-alanine, and triethanolamine hydrochloride Hydroxy Although selected from such as hydrochloric acid salt of an amine having a group it may be used as a mixture of two or more.
[0035]
This organic undercoat layer can be provided by the following method. That is, a method in which water or an organic solvent such as methanol, ethanol, methyl ethyl ketone, or a mixed solvent thereof is dissolved and applied on an aluminum plate and dried, and water, methanol, ethanol, methyl ethyl ketone, etc. The organic compound is dissolved in an organic solvent or a mixed solvent thereof, and the organic compound is adsorbed by immersing the aluminum substrate in the solution, and then washed with water or the like to dry the organic solution in various ways. Can be applied. For example, any method such as bar coater coating, spin coating, spray coating, or curtain coating may be used. In the latter method, the concentration of the solution is 0.01 to 20% by weight, preferably 0.05 to 5% by weight, the immersion temperature is 20 to 90 ° C., preferably 25 to 50 ° C., and the immersion time. Is 0.1 second to 20 minutes, preferably 2 seconds to 1 minute.
[0036]
The solution used for this can be used in a pH range of 1 to 12 by adjusting the pH with a basic substance such as ammonia, triethylamine or potassium hydroxide, or an acidic substance such as hydrochloric acid or phosphoric acid. A yellow dye can also be added to improve the tone reproducibility of the photopolymerizable lithographic printing plate.
[0037]
The coating amount of the organic undercoat layer after drying is 2 to 200 mg / m²Is suitable, preferably 5 to 100 mg / m²It is. The above coating amount is 2 mg / m²If it is less, sufficient printing durability cannot be obtained. 200 mg / m²It is the same even if it is larger.
[0038]
Further, the aluminum support may be further subjected to surface treatment such as immersion treatment in an aqueous solution of potassium fluorinated zirconate, phosphate or the like.
[0039]
[Adhesive layer]
After the pore-wide treatment after the anodizing treatment, an adhesive layer containing a silicone compound having a functional group capable of causing an addition reaction by radicals (hereinafter referred to as an addition-reactive functional group) is further coated on the surface as necessary. Also good.
[0040]
The layer containing the silicone compound having an addition reactive functional group is preferably applied by a method using an organic silicone compound as a raw material. Specifically, the addition-reactive functional group is R¹The following formula (1):
R¹Si (OR²)_Three        (1)
(Where, -OR²Is a hydrolyzable alkoxy group or -OCOCH_ThreeIt is a group. By treating the aluminum substrate with the organosilicone compound (1) represented by), the substrate surface metal, metal oxide, hydroxide, -OH group, silanol group formed by chemical conversion treatment of the substrate, etc. To form a covalent bond with the substrate surface, and the following formula (2):
(R^ThreeO)₂(R¹) Si- (2)
The functional group represented by can be bonded (or planted) to the substrate surface. Where R^ThreeIs R²Represents a bond with the same or different alkyl group or hydrogen atom, or another adjacent Si atom.
[0041]
In the above, addition-reactive functional group (R¹) Are bonded to the central Si atom by the following formula (1a) or (1b):
(R¹)₂Si (OR²)₂        (1a)
(R¹)_ThreeSiOR²              (1b)
It is also possible to use organic silicone compounds (1a) and (1b) represented by
[0042]
In addition, addition-reactive functional groups (R¹) Is a functional group bonded to the central Si atom via —O—,
(R¹)_FourSi (1c)
It is also possible to use an organic silicone compound (1c) represented by
[0043]
Organosilicone compound (1) consists of 4 R bonded to the central Si atom.¹When at least one of these remains unhydrolyzed, it is applied to a lithographic printing plate support.
[0044]
When the organosilicone compound (1) is coated on a lithographic printing plate support, it may be used alone or diluted with an appropriate solvent. Water and / or a catalyst can be added to bind the organosilicone compound (1) more firmly on the lithographic printing plate support. As the solvent, alcohols such as methanol, ethanol, propanol, isopropanol, ethylene glycol and hexylene glycol are preferable, and as the catalyst, acids such as hydrochloric acid, acetic acid, phosphoric acid and sulfuric acid, or ammonia, tetramethylammonium hydroxide, etc. A base can be used. The amount of the addition-reactive functional group on the lithographic printing plate support varies depending on the type of the addition-reactive functional group to be bonded, but is 10 nm.²In general, it is appropriate to set the number to 0.01 to 1000, preferably 0.05 to 200, and more preferably 0.1 to 50. Additive functional group amount is 10nm²When the number is less than 0.01 per unit, it is difficult to obtain sufficient photoadhesive strength. By thickly coating the organic silicone compound (1), 10 nm²It is possible to increase the amount of the addition-reactive functional group per unit substantially, but the amount of the addition-reactive functional group that makes a face on the outermost surface is 10 nm.²Since there are at most 10 pieces per hit, it is useless even if it is applied too thickly. In order that the amount of addition-reactive functional groups is excessive and the hydrophilicity of the non-image area when used as a PS plate is not insufficient, 10 nm²The amount of the addition-reactive functional group per hit is preferably 1000 or less.
[0045]
Therefore, when an addition-reactive functional group is bonded (planted) to the surface of a lithographic printing plate support using an organosilicone compound, the type and amount of the solvent for diluting the organosilicone compound, for hydrolysis on the substrate surface The amount of water added to the support (if added), the type and amount of catalyst to promote hydrolysis on the support surface (if added), the method of applying the organosilicone compound solution on the support, and the support It is necessary to change the process parameters such as drying atmosphere after application, drying temperature, drying time, etc., and control the amount of additional reactive functional groups retained on the support surface to be within the above range. It is.
[0046]
The amount of the addition-reactive functional group retained on the lithographic printing plate support surface is determined by measuring the surface of the support after the treatment by an appropriate method such as a fluorescent X-ray analysis method or an infrared absorption method. It is possible to determine by determining the amount of Si atoms in the substrate, determining the amount of carbon-carbon multiple bonds, and the like.
[0047]
However, when a PS plate is formed using this support (addition-reactive support), printing stains are generated only by treating the support for a lithographic printing plate using only the organosilicone compound of formula (1). There is a case. That is, a photopolymerizable photosensitive composition is coated on a support formed by adding an addition-reactive functional group to provide a photosensitive layer, and imagewise exposure is performed on this to cause interfacial photoadhesion according to the image. By removing the unexposed portion with a developer, a photopolymerization adhesion film according to the light pattern remains on the support. And when ink and water are applied to this, the ink adheres to the imagewise exposed part that has been photopolymerized and adhered, and water adheres to the unexposed part to form a printing plate, but when the organosilicone compound is used alone, In some cases, an excessive organic functional group may be present in an unexposed portion where water should adhere, and ink may adhere to the printed matter in addition to water and may be observed as a stain on the printed matter.
[0048]
Therefore, in order to prevent this printing stain, an addition-reactive functional group (R) is formed on the surface of the lithographic printing plate support.¹In addition to the above, it is preferable to increase the hydrophilicity by fixing many OH groups.
[0049]
Preferably, in the attachment of the addition-reactive functional group to the support surface, the formula (1): R¹Si (OR²)_ThreeIn addition to the organic silicone compound (1) represented by formula (3): Si (OR^Four)_Four(Where, -OR^FourIs a hydrolyzable alkoxy group, alkoxyalkoxy group, aryloxy group or -OCOCH_ThreeR^FourIs R²May be the same or different. The organic silicone compound (3) represented by the formula (2) is used in combination with the reaction site represented by the above formula (2) on the substrate surface, and at the same time, the formula (4):
(R^ThreeO)₂(OH) Si- (4)
It is preferable to bind a hydrophilic site represented by Where R^ThreeRepresents an alkyl group, a hydrogen atom, or a bond with another adjacent Si atom,^ThreeIs most preferably a hydrogen atom from the viewpoint of hydrophilicity. R^ThreeWhen is other than a hydrogen atom, the hydrophilicity can be enhanced by washing the surface with an alkaline solution as necessary.
[0050]
The mixing ratio of the organosilicone compound (1) of the formula (1) and the organosilicone compound (3) of the formula (3) varies depending on the properties of the support. Therefore, a suitable range cannot be determined in general. However, specifically, the support treatment is performed by changing the ratio of the two in various ways, and the addition-reactive functional group R¹The conditions under which both the photoadhesive property based on the formula and the hydrophilicity derived from the partial structure represented by the formula (4) are experimentally determined are used. In any case, the density of the addition-reactive functional group may be set within the above range. Specifically, the mixing molar ratio of the organic silicone compound (3) to the organic silicone compound (1) is suitably 0.05 to 500, preferably 0.2 to 200, more preferably 1 to 100. .
[0051]
Within this range, the hydrophilicity of the non-image area increases as the amount of the hydrophilic group derived from the organosilicone compound (3) of the formula (3) is increased.
[0052]
However, even when the density of the hydrophilic group is low, the density of the hydrophilic group can be improved by hydrophilizing the addition-reactive functional group.
[0053]
In addition to the above-mentioned method (hereinafter referred to as the SC method) which consists of using an organic silicone compound as it is, the organic silicone compound can be broadly classified for bonding an addition-reactive functional group to the surface of a lithographic printing plate support. A method comprising using an organic-inorganic composite in a form in which an addition-reactive functional group is fixed to an inorganic polymer containing a —Si—O—Si— bond obtained by hydrolyzing and polycondensing a compound , SG method).
[0054]
When this organic-inorganic composite is applied to an aluminum substrate and dried, the inorganic polymer portion adheres to the support, and the addition-reactive functional group remains on the support surface as it is.
[0055]
In the case of the SC method, the bonding position of the addition-reactive functional group on the lithographic printing plate support surface is likely to have a specific property on the support surface, and it is difficult to uniformly distribute it on the support surface. There are cases. That is, a covalent bond between Si atoms is formed only at specific acid points and base points, and the distribution of addition-reactive functional groups is likely to be governed by the distribution of acid points and base points on the surface of the lithographic printing plate support. . Therefore, unevenness may occur in photoadhesive strength and non-image area hydrophilicity. In such a situation, it is advantageous to follow the SG method. If it looks closely, in addition to SC method and SG method, it is an intermediate aspect, for example, organosilicone compound (1) of formula (1): R¹Si (OR²)_ThreeOR inside²A treatment using an organosilicone compound in which two or three molecules are bonded by hydrolysis of a part or all of these as starting materials is also possible.
[0056]
According to the addition method of the addition reactive functional group by the SG method, the organosilicone compound (1) of the formula (1) is optionally mixed with the organosilicone compound (3) of the formula (3) in a desired mixing ratio, In the liquid, if necessary in the presence of a catalyst, the addition-reactive functional group R¹-OR without causing a reaction²And -OR^FourAs a liquid composition containing an inorganic polymer in which Si atoms at the center are connected by —Si—O—Si— bonds, the resultant is applied to the surface of a lithographic printing plate support by hydrolysis and polycondensation. The addition-reactive functional group is bonded onto the support by optionally drying.
[0057]
When the SG method is used, the distribution of addition-reactive functional groups bonded and immobilized on the surface of a lithographic printing plate support depends on the distribution of chemical properties such as acid points and base points on the support surface. Few. Further, when the organic silicone compound (3) is used in addition to the organic silicone compound (1) as a starting material, the addition-reactive functional group site represented by the above formula (2) and the hydrophilicity represented by the above formula (4). Since the relative ratio to the site is almost determined by the charging ratio of the organic silicone compound (1) and the compound (3), there is an advantage that the route for determining the prescription for obtaining the optimum surface is more orderly than the SC method.
[0058]
Specific examples of the organic silicone compound (1) represented by the above formula (1) used in the present invention include the following.
[0059]
CH₂= CH-Si (OCOCH_Three)_Three
CH₂= CH-Si (OC₂H_Five)_Three
CH₂= CH-Si (OCH_Three)_Three
CH₂= CHCH₂-Si (OC₂H_Five)_Three
CH₂= CHCH₂NH (CH₂)_Three-Si (OCH_Three)_Three
CH₂= CHCOO- (CH₂)_Three-Si (OCH_Three)_Three
CH₂= CHCOO- (CH₂)_Three-Si (OC₂H_Five)_Three
CH₂= C (CH_Three) COO- (CH₂)_Three-Si (OCH_Three)_Three
CH₂= C (CH_Three) COO- (CH₂)_Three-Si (OC₂H_Five)_Three
CH₂= C (CH_Three) COO- (CH₂)_Four-Si (OCH_Three)_Three
CH₂= C (CH_Three) COO- (CH₂)_Five-Si (OCH_Three)_Three
CH₂= CHCOO- (CH₂)_Four-Si (OCH_Three)_Three
(CH₂= C (CH_Three) COO- (CH₂)_Three)₂-Si (OCH_Three)₂
CH₂= C (CH = CH₂) -Si (OCH_Three)_Three
CH₂= CH-SO₂NH- (CH₂)_Three-Si (OCH_Three)_Three
CH₂= CH-ph-O-Si (OCH_Three)_Three
CH₂= CH-ph-CONH- (CH₂)_Three-Si (OCH_Three)_Three
CH₂= CH-ph-CH₂NH- (CH₂)_Three-Si (OCH_Three)_Three
ph: indicates a benzene ring
HC≡C-Si (OC₂H_Five)_Three
CH_ThreeC≡C-Si (OC₂H_Five)_Three
[Chemical 1]
CH₂= CHCH₂O-Si (OCH_Three)_Three
(CH₂= CHCH₂O)_FourSi
HO-CH₂-C≡C-Si (OC₂H_Five)_Three
CH_ThreeCH₂CO-C≡C-Si (OC₂H_Five)_Three
CH₂= CHS- (CH₂)_Three-Si (OCH_Three)_Three
CH₂= CHCH₂O- (CH₂)₂-SCH₂-Si (OCH_Three)_Three
CH₂= CHCH₂S- (CH₂)_Three-S-Si (OCH_Three)_Three
(CH_Three)_ThreeCCO-C≡C-Si (OC₂H_Five)_Three
(CH₂= CH)₂N- (CH₂)₂-SCH₂-Si (OCH_Three)_Three
CH_ThreeCOCH = C (CH_Three) -O-Si (OCH_Three)_Three
[0060]
Specific examples of the organic silicone compound (3) represented by the formula (3) include tetramethoxysilane, tetraethoxysilane, tetraisopropoxysilane, tetra (n-propoxy) silane, tetra (n-butoxy) silane, and tetrakis. (2-Ethylbutoxy) silane, tetrakis (2-ethylhexyloxy) silane, tetrakis (2-methoxyethoxy) silane, tetraphenoxy silane, tetraacetoxy silane and the like can be mentioned, among which tetraethoxy silane is preferable.
[0061]
Although the SC method and the SG method are used to bind the addition-reactive functional group to the lithographic printing plate support surface, the type of solvent, the application method to the support, the drying method, etc. are common. In the case of the SG method, it is necessary to prepare an inorganic polymer composition retaining an addition-reactive functional group in advance. The preferable specific example is shown below.
[0062]
Solvents that can be used to polycondense the organosilicone compounds (1) and (3) represented by the formulas (1) and (3) together with hydrolysis into a composition suitable for the SG method are methanol, ethanol, propanol , Alcohols such as isopropanol, ethylene glycol and hexylene glycol.
[0063]
The amount of the solvent used is generally 0.2 to 500 times, preferably 0.5 to 100 times, more preferably 1 to 20 times, based on the total weight of the organic silicone compounds (1) and (3) used. is there. If the amount used is less than 0.2 times, the reaction solution tends to gel with time and becomes unstable, which is not preferable. On the other hand, if it exceeds 500 times, the reaction takes several days, which is not preferable.
[0064]
The amount of water added to hydrolyze the organosilicone compound is generally from 0.1 to 1000 mol, preferably from 0.5 to 200 mol, more preferably from 1.5 to 100 mol, per mol of the organosilicone compound. When the amount of water is less than 0.1 mol per 1 mol of the organosilicone compound, the hydrolysis and subsequent polycondensation reaction proceeds very slowly, and it takes several days until stable surface treatment is possible. It is not preferable. On the other hand, when the amount of water is more than 1000 moles per mole of the organic silicone compound, when the composition formed is applied to the metal surface, adhesion failure occurs, and the composition is poorly stable over time and immediately gels. In many cases, the coating operation is difficult to be performed stably.
[0065]
The reaction temperature for preparing a composition suitable for the SG method is usually room temperature to about 100 ° C., but depending on the type of catalyst described below, a temperature of room temperature or lower or 100 ° C. or higher can also be used. The reaction can be carried out at a temperature higher than the boiling point of the solvent, and a reflux condenser is preferably attached to the reactor as necessary.
[0066]
Catalysts used as necessary include acids such as hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, acetic acid, malic acid, and oxalic acid, or bases such as ammonia, tetramethylammonium hydroxide, potassium hydroxide, and sodium hydroxide. Can be used.
[0067]
The addition amount of the catalyst is 0.001 to 1 mol, preferably 0.002 to 1 mol per mol of the organic silicone compound, based on the total amount of the organic silicone compound (1) and optionally added organic silicone compound (3). The amount is 0.7 mol, more preferably 0.003 to 0.4 mol. Even if the addition amount of the catalyst is more than 1 mol, there is no particular economic advantage compared to the addition effect.
[0068]
When a weak acid such as acetic acid or malic acid is used as a catalyst, the reaction temperature is advantageously in the range of 40 ° C. to 100 ° C., but when a strong acid such as sulfuric acid or nitric acid is used as a catalyst, 10 ° C. to A range of 60 ° C. is preferable. When phosphoric acid is used as a catalyst, the reaction can be carried out at 10 to 90 ° C.
[0069]
In the step of preparing the composition used in the SG method and the step of applying and drying the composition on an aluminum substrate, heat is often applied. However, if a volatile acid is used as a catalyst, it will volatilize in the surrounding equipment. It may adhere and corrode it. When this method is used mainly in a process using iron as a raw material, it is preferable to use non-volatile sulfuric acid and / or phosphoric acid as a catalyst.
[0070]
As described above, a composition comprising the organic silicone compound represented by the formulas (1) and (3), an organic solvent, water, and optionally a catalyst, can be prepared at an appropriate reaction temperature, reaction time, and in some cases. When the stirring conditions are selected and reacted, a polycondensation reaction occurs along with hydrolysis to produce a polymer or a colloidal polymer containing Si—O—Si bonds, and the viscosity of the liquid composition is increased to form a sol.
[0071]
When preparing a sol solution using both organosilicone compounds represented by formulas (1) and (3), both organosilicone compounds may be loaded into the reaction vessel from the beginning of the reaction, or only one of them. After the hydrolysis and polycondensation reaction have proceeded to some extent, the other organosilicone compound may be added to terminate the reaction.
[0072]
When the sol solution used in the SG method is allowed to stand at room temperature, the polycondensation reaction may continue to cause gelation. Therefore, once the sol solution prepared by the above method is diluted in advance with a solvent to be used for dilution when applied to the aluminum substrate, gelation of the sol solution can be prevented or delayed. .
[0073]
In both the SC method and the SG method, in order to bond a target amount of an organosilicone compound or an addition-reactive functional group on a support, and uneven distribution of the organosilicone compound or the addition-reactive functional group on the support. In order to prevent this, it is preferable to adjust the concentration by adding a solvent before applying these treatment liquids to the support. As the solvent used for this purpose, alcohols, particularly methanol, are suitable, but other solvents, organic compounds, inorganic additives, surfactants and the like can also be added.
[0074]
Examples of other solvents include methyl ethyl ketone, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, 2-methoxyethyl acetate, 1-methoxy-2-propyl acetate, dimethoxyethane, methyl lactate, ethyl lactate, acetylacetone, ethylene glycol, etc. Can be mentioned.
[0075]
Examples of organic compounds that can be added include epoxy resins, acrylic resins, butyral resins, urethane resins, novolac resins, pyrogallol-acetone resins, polyvinyl pyrrolidone, polyvinyl alcohol, polyvinyl methyl ether, and polypropylene glycol.
[0076]
Examples of inorganic additives include colloidal silica and colloidal alumina.
[0077]
High-boiling solvents such as ethylene glycol and ethylene glycol monomethyl ether increase the stability of the liquid diluted to the concentration applied to the support and guarantee the reproducibility of the additional reactive functional groups attached to the support. There is work. Organic compounds such as novolak resin and pyrogallol-acetone resin also have the same effect, but have the side effect of reducing the hydrophilicity of the surface of the obtained support, and the addition amount needs to be finely adjusted.
[0078]
A sol solution or liquid composition suitable for the SG method is coated on the surface of a lithographic printing plate support and then air-dried or heated to dry, and simultaneously, the inorganic polymer comprising Si—O—Si bonds gels and the substrate surface. Covalently bond with Drying is performed to volatilize the solvent, residual water, and optionally the catalyst, but the process can be omitted depending on the purpose of use of the substrate after the treatment. Also in the SC method, this drying step has the meaning of ensuring adhesion with the support for an organic silicone compound lithographic printing plate, in addition to the meaning of volatilization of solvent, residual water and the like.
[0079]
Therefore, depending on the purpose, heating may be continued even after drying is completed.
[0080]
The maximum temperature in drying and optionally subsequent heating is the addition-reactive functional group R¹Is preferably in a range that does not decompose. Accordingly, usable drying temperature conditions are room temperature to 200 ° C, preferably room temperature to 150 ° C, and more preferably room temperature to 120 ° C.
[0081]
The drying time is generally 1 second to 30 minutes, preferably 5 seconds to 10 minutes, more preferably 10 seconds to 3 minutes.
[0082]
Various methods such as brush coating, dip coating, atomizing, spin coating, doctor blade coating, etc. can be used as the method of applying the liquid composition (organosilicone compound or solution or sol solution) used in the present invention. The thickness is determined in consideration of the shape of the lithographic printing plate support surface, the required film thickness, and the like.
[0083]
[Photopolymerizable photosensitive layer]
The main component of the photopolymerizable photosensitive layer provided on the support of the present invention is a compound containing an ethylenic double bond capable of addition polymerization, a photopolymerization initiator, an organic polymer binder, and the like. Various compounds such as a colorant, a plasticizer, and a thermal polymerization inhibitor are added.
[0084]
The compound containing a double bond capable of addition polymerization can be arbitrarily selected from compounds having at least one, preferably two or more terminal ethylenically unsaturated bonds.
[0085]
For example, those having chemical forms such as monomers, prepolymers, that is, dimers, trimers and oligomers, or mixtures thereof and copolymers thereof.
[0086]
Examples of monomers and copolymers thereof include esters of unsaturated carboxylic acids (eg, acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid, etc.) with aliphatic polyhydric alcohol compounds, unsaturated Examples include amides of carboxylic acids and aliphatic polyvalent amine compounds.
[0087]
Specific examples of an ester monomer of an aliphatic polyhydric alcohol compound and an unsaturated carboxylic acid include acrylic acid esters such as ethylene glycol diacrylate, triethylene glycol diacrylate, 1,3-butanediol diacrylate, and tetramethylene. Glycol diacrylate, propylene glycol diacrylate, neopentyl glycol diacrylate, trimethylolpropane triacrylate, trimethylolpropane tri (acryloyloxypropyl) ether, trimethylolethane triacrylate, hexanediol diacrylate, 1,4-cyclohexanediol di Acrylate, Tetraethylene glycol diacrylate, Pentaerythritol diacrylate, Pentaerythritol triacrylate , Pentaerythritol tetraacrylate, dipentaerythritol diacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, sorbitol triacrylate, sorbitol tetraacrylate, sorbitol pentaacrylate, sorbitol hexaacrylate, tri (acryloyloxyethyl) isocyanurate, polyester Examples include acrylate oligomers.
[0088]
Methacrylic acid esters include tetramethylene glycol dimethacrylate, triethylene glycol dimethacrylate, neopentyl glycol dimethacrylate, trimethylolpropane trimethacrylate, trimethylolethane trimethacrylate, ethylene glycol dimethacrylate, 1,3-butanediol dimethacrylate, Hexanediol dimethacrylate, pentaerythritol dimethacrylate, pentaerythritol trimethacrylate, pentaerythritol tetramethacrylate, dipentaerythritol dimethacrylate, dipentaerythritol hexamethacrylate, dipentaerythritol pentamethacrylate, sorbitol trimethacrylate, sorbitol tetramethacrylate, bis [ - (3-methacryloxy-2-hydroxypropoxy) phenyl] dimethyl methane, bis - [p-(methacryloxyethoxy) phenyl] dimethyl methane.
[0089]
Itaconic acid esters include ethylene glycol diitaconate, propylene glycol diitaconate, 1,3-butanediol diitaconate, 1,4-butanediol diitaconate, tetramethylene glycol diitaconate, pentaerythritol diitaconate And sorbitol tetritaconate.
[0090]
Examples of crotonic acid esters include ethylene glycol dicrotonate, tetramethylene glycol dicrotonate, pentaerythritol dicrotonate, and sorbitol tetradicrotonate.
[0091]
Examples of isocrotonic acid esters include ethylene glycol diisocrotonate, pentaerythritol diisocrotonate, and sorbitol tetraisocrotonate.
[0092]
Examples of maleic acid esters include ethylene glycol dimaleate, triethylene glycol dimaleate, pentaerythritol dimaleate, and sorbitol tetramaleate.
[0093]
Furthermore, the mixture of the above-mentioned ester monomer can be mention | raise | lifted.
[0094]
Specific examples of amide monomers of aliphatic polyvalent amine compounds and unsaturated carboxylic acids include methylene bis-acrylamide, methylene bis-methacrylamide, 1,6-hexamethylene bis-acrylamide, 1,6-hexamethylene bis. -Methacrylamide, diethylenetriamine trisacrylamide, xylylene bisacrylamide, xylylene bismethacrylamide and the like.
[0095]
As another example, the polyisocyanate compound having two or more isocyanate groups in one molecule described in JP-B-48-41708 contains a hydroxyl group represented by the following general formula (A). Examples thereof include a vinyl urethane compound containing two or more polymerizable vinyl groups in one molecule to which a vinyl monomer is added.
CH₂= C (R^Five) COOCH₂CH (R⁶) OH (A)
(However, R^FiveAnd R⁶Is H or CH_ThreeIndicates. )
[0096]
Further, as described in JP-A-51-37193, urethane acrylates, JP-A-48-64183, JP-B-49-43191, JP-B-52-30490, etc. And polyfunctional acrylates and methacrylates such as polyester acrylates and epoxy acrylates obtained by reacting an epoxy resin with (meth) acrylic acid. Furthermore, what is introduced as a photocurable monomer and oligomer in Japan Adhesive Association Journal vol. 20, No. 7, pages 300 to 308 (1984) can also be used. In addition, the usage-amount of these is 5-70 weight% (henceforth%) with respect to all the components, Preferably it is 10-50%.
[0097]
Depending on the wavelength of the light source used, various photoinitiators known in patents, literature, etc., or a combination system of two or more photoinitiators (photoinitiation system) are appropriately selected and used as the photopolymerization initiator can do.
[0098]
For example, when light near 400 nm is used as a light source, benzyl, benzoin ether, Michler's ketone, anthraquinone, thioxanthone, acridine, phenazine, benzophenone, and the like are widely used.
[0099]
Also, various photoinitiating systems have been proposed in the case of using visible light of 400 nm or more, Ar laser, second harmonic of a semiconductor laser, or SHG-YAG laser as a light source, for example, US Pat. No. 2,850. 445, certain photoreducible dyes such as rose bengal, eosin, erythrosine, etc., or a combination of a dye and an initiator, such as a complex initiator system of a dye and an amine (Japanese Patent Publication No. 44-20189). No.), a combination system of hexaarylbiimidazole, a radical generator and a dye (Japanese Patent Publication No. 45-37377), a system of hexaarylbiimidazole and p-dialkylaminobenzylidene ketone (Japanese Patent Publication No. 47-2528, JP-A-54-155292), a system of a cyclic cis-α-dicarbonyl compound and a dye (JP-A-48-84) 183), a system of cyclic triazine and merocyanine dye (Japanese Patent Laid-Open No. 54-151024), a system of 3-ketocoumarin and an activator (Japanese Patent Laid-Open No. 52-112682, Japanese Patent Laid-Open No. 58-15503) , Biimidazole, styrene derivative, thiol system (JP 59-140203 A), organic peroxide and dye system (JP 59-1504 A, JP 59-140203 JP, JP JP-A-59-189340, JP-A-62-174203, JP-B-62-1641, US Pat. No. 4,766,055), system of dye and active halogen compound (JP-A-63-1718105, JP-A JP-A 63-258903, JP-A 2-63054, etc.) Dye and borate compound systems (JP-A-62-143044, JP-A 62-62) No. 50242, JP-A No. 64-13140, JP-A No. 64-13141, JP-A No. 64-13142, JP-A No. 64-13143, JP-A No. 64-13144, JP-A 64-17048, JP-A-1-229003, JP-A-1-298348, JP-A-1-138204, etc.) A system comprising a dye having a rhodanine ring and a radical generator (JP-A-2-179634) No. 2, JP-A-2-244050), titanocene and 3-ketocoumarin dye systems (JP-A 63-221110), titanocene and xanthene dyes, addition-polymerizable ethylenic monomers containing amino groups or urethane groups. Systems combining saturated compounds (JP-A-4-221958, JP-A-4-219756), titanocene and System constant merocyanine dye (JP-A-6-295061), and the like can be given dye system with titanocene and benzopyran ring (Japanese Patent Application No. 7-164583).
[0100]
The amount of these photopolymerization initiators used is 0.05 to 100 parts by weight, preferably 0.1 to 70 parts by weight, more preferably 0.2 to 50 parts by weight, based on 100 parts by weight of the ethylenically unsaturated compound. It can be used in the range.
[0101]
The photopolymerizable composition usually contains an organic polymer as a binder, and as such an organic polymer, an organic compound compatible with a photopolymerizable ethylenically unsaturated compound is used. Any polymer can be used as long as it is a high molecular weight polymer. Preferably, an organic high molecular weight polymer that is water-soluble or weakly alkaline water-soluble or swellable is selected. The organic polymer is selected and used not only as a film-forming agent for the composition but also according to its use as water, weak alkaline water or an organic solvent developer. For example, when a water-soluble organic polymer is used, water development is possible. Examples of such an organic polymer include addition polymers having a carboxylic acid group in the side chain, such as JP 59-44615, JP-B 54-34327, JP-B 58-12577, JP-B 54-. No. 25957, JP 54-92723, JP 59-53836, JP 59-71048, ie, methacrylic acid copolymer, acrylic acid copolymer, itaconic acid Examples include copolymers, crotonic acid copolymers, maleic acid copolymers, and partially esterified maleic acid copolymers.
[0102]
Similarly, there is an acidic cellulose derivative having a carboxylic acid group in the side chain. In addition, a product obtained by adding a cyclic acid anhydride to an addition polymer having a hydroxyl group is useful. Among these, [benzyl (meth) acrylate / (meth) acrylic acid / other addition-polymerizable vinyl monomers as required] copolymer and [allyl (meth) acrylate (meth) acrylic acid / as needed Other addition polymerizable vinyl monomers] copolymers are preferred. In addition, polyvinyl pyrrolidone, polyethylene oxide, and the like are useful as the water-soluble organic polymer. In order to increase the strength of the cured film, alcohol-soluble polyamide, polyether of 2,2-bis- (4-hydroxyphenyl) -propane and epichlorohydrin, and the like are also useful. These organic high molecular polymers can be mixed in an arbitrary amount in the whole composition. However, when it exceeds 90% by weight, a favorable result is not given in terms of the strength of the formed image. Preferably it is 10 to 90%, More preferably, it is 30 to 80%. The photopolymerizable ethylenically unsaturated compound and the organic polymer are preferably in the range of 1/9 to 9/1 by weight. A more preferable range is 2/8 to 8/2, still more preferably 3/7 to 7/3.
[0103]
In the present invention, in addition to the above basic components, a small amount of a thermal polymerization inhibitor is added to prevent unnecessary thermal polymerization of the ethylenically unsaturated compound that can be polymerized during the production or storage of the photosensitive composition. It is desirable to do. Suitable thermal polymerization inhibitors include haloid quinone, p-methoxyphenol, di-t-butyl-p-cresol, pyrogallol, t-butylcatechol, benzoquinone, 4,4'-thiobis (3-methyl-6-t-butylphenol ) 2,2′-methylenebis (4-methyl-6-tert-butylphenol), N-nitrosophenylhydroxylamine cerium salt, N-nitrosophenylhydroxylamine aluminum salt and the like. The amount of the thermal polymerization inhibitor added is preferably about 0.01% to about 5% based on the weight of the total composition. If necessary, a higher fatty acid derivative such as behenic acid or behenic acid amide may be added to prevent polymerization inhibition due to oxygen, and it may be unevenly distributed on the surface of the photosensitive layer in the course of drying after coating. . The amount of the higher fatty acid derivative added is preferably about 0.5% to about 10% of the total composition.
[0104]
Further, a colorant may be added for the purpose of coloring the photosensitive layer. Examples of the colorant include phthalocyanine pigments (C.I. Pigment Blue 15: 3, 15: 4, 15: 6, etc.), azo pigments, pigments such as carbon black and titanium oxide, ethyl violet, crystal violet, There are azo dyes, anthraquinone dyes, and cyanine dyes. The amount of dye and pigment added is preferably from about 0.5% to about 20% of the total composition.
[0105]
In addition, in order to improve the physical properties of the cured film, an additive such as an inorganic filler or a plasticizer such as dioctyl phthalate, dimethyl phthalate, or tricresyl phosphate may be added.
[0106]
These addition amounts are preferably 10% or less of the total composition.
[0107]
When the photopolymerizable composition of the present invention is applied on a support, it is dissolved in various organic solvents and used. Solvents used here include acetone, ethyl ethyl ketone, cyclohexane, ethyl acetate, ethylene dichloride, tetrahydrofuran, toluene, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol dimethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl. Ether, acetylacetone, cyclohexanone, diacetone alcohol, ethylene glycol monomethyl ether acetate, ethylene glycol ethyl ether acetate, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether acetate, 3-methoxypropanol, methoxymethoxyethanol, diethylene glycol monomethyl ether, Ethylene glycol monoethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, 3-methoxypropyl acetate, N, N-dimethylformamide, dimethyl sulfoxide, γ-butyrolactone, methyl lactate, lactic acid Ethyl and so on. These solvents can be used alone or in combination. The solid content in the coating solution is suitably 1 to 50% by weight.
[0108]
A surfactant can be added to the photopolymerizable composition in the present invention in order to improve the coating surface quality.
[0109]
The coating amount is about 0.1 g / m in weight after drying.²~ About 10g / m²The range of is appropriate. More preferably 0.3 to 5 g / m²It is. More preferably 0.5-3 g / m²It is.
[0110]
[Oxygen barrier protective layer]
In the present invention, after providing the photosensitive layer on the support, an oxygen-blocking protective layer is provided thereon as necessary. Examples of the water-soluble vinyl polymer contained in the oxygen-blocking protective layer include polyvinyl alcohol and its partial esters, ethers, and acetals, or a substantial amount of unsubstituted vinyl alcohol that makes them necessary water-soluble. Examples thereof include copolymers containing units. Examples of polyvinyl alcohol include those having a hydrolysis degree of 71 to 100% and a polymerization degree in the range of 300 to 2400. Specifically, Kuraray Co., Ltd. PVA-105, PVA-110, PVA-117, PVA-117H PVA-120, PVA-124, PVA-124H, PVA-CS, PVA-CST, PVA-HC, PVA-203 , PVA-204, PVA-205, PVA-210, PVA-217, PVA-220, PVA-224, PVA-217EE, PVA-220, PVA-224, PVA-217EE, PVA-217E, PVA-220E, PVA -224E, PVA-405, PVA-420, PVA-613, L-8 and the like. Examples of the copolymer include 88-100% hydrolyzed polyvinyl acetate chloroacetate or propionate, polyvinyl formal and polyvinyl acetal, and copolymers thereof. Other useful polymers include polyvinyl pyrrolidone, gelatin and gum arabic, and these may be used alone or in combination.
[0111]
The solvent used when applying the oxygen-blocking protective layer of the present invention is preferably pure water, but alcohols such as methanol and ethanol, and ketones such as acetone and methyl ethyl ketone may be mixed with pure water. The concentration of the solid content in the coating solution is suitably 1 to 20% by weight.
[0112]
The oxygen barrier protective layer of the present invention may further contain known additives such as a surfactant for improving the coating property and a water-soluble plasticizer for improving the physical properties of the film.
[0113]
Examples of the water-soluble plasticizer include propionamide, cyclohexanediol, glycerin, sorbitol and the like. Further, a water-soluble (meth) acrylic polymer may be added.
[0114]
The amount of clothing is about 0.1 / m in weight after drying.²~ 15 / m²The range of is appropriate. More preferably 1.0 / m²~ About 5.0 / m²It is.
[0115]
The photosensitive lithographic printing plate thus obtained is directly exposed to an Ar laser, a second harmonic of a semiconductor laser (SHG-LD, 350 to 600 nm), and a YAG-SHG laser, and then developed.
[0116]
A conventionally known alkaline aqueous solution can be used as the developer used in such development processing. For example, sodium silicate, potassium, tribasic sodium phosphate, potassium, ammonium, dibasic sodium phosphate, potassium, ammonium, sodium carbonate, potassium, ammonium, sodium bicarbonate, potassium Examples include inorganic alkaline agents such as ammonium, sodium borate, potassium, ammonium, sodium hydroxide, ammonium, potassium, and lithium. In addition, monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine, triethylamine, monoisopropylamine, diisopropylamine, triisopropylamine, n-butylamine, monoethanolamine, diethanolamine, triethanolamine, monoisopropanolan, diisopropanolamine, Organic alkali agents such as ethyleneimine, ethylenediamine, and pyridine are also used.
[0117]
These alkali agents are used alone or in combination of two or more.
[0118]
Among the above-mentioned alkaline aqueous solutions, a developing solution that exhibits the effect of the present invention is an aqueous solution containing alkali metal silicate and having a pH of 12 or more. The aqueous solution of alkali metal silicate is silicon oxide SiO which is a component of silicate.₂And alkali metal oxide M₂O ratio (generally [SiO₂] / [M₂The development property can be adjusted by adjusting the concentration and the concentration of O], for example, as disclosed in Japanese Patent Application Laid-Open No. 54-62004.₂/ Na₂The molar ratio of O is 1.0 to 1.5 (ie [SiO₂] / [Na₂O] is 1.0 to 1.5, and SiO₂An aqueous solution of sodium silicate having a content of 1 to 4% by weight, or [SiO 2 as described in Japanese Patent Publication No. 57-7427.₂] / [M] is 0.5 to 0.75 (ie, [SiO₂] / [M₂O] is 1.0 to 1.5), and SiO₂An alkali metal silicate having a concentration of 1 to 4% by weight and the developer containing at least 20% potassium, based on gram atoms of all alkali metals present therein Are preferably used.
[0119]
Further, when the photosensitive lithographic printing plate is developed using an automatic developing machine, an aqueous solution (replenisher) having a higher alkali strength than the developer is added to the developer, so that the developer in the developer tank for a long time. It is known that a large amount of photosensitive lithographic printing plate can be processed without replacing the plate. This replenishment method is also preferably applied in the present invention. For example, the developer [SiO 2 as disclosed in JP-A-54-62004 is disclosed.₂] / [Na₂The molar ratio of O] is 1.0 to 1.5 (that is, [SiO₂] / [Na₂O] is 1.0 to 1.5), and SiO₂An aqueous solution of sodium silicate having a content of 1 to 4% by weight is used, and the SiO 2 is continuously or intermittently changed depending on the processing amount of the positive photosensitive lithographic printing plate.₂/ Na₂The molar ratio of O is 0.5 to 1.5 (ie [SiO₂] / [Na₂A method of adding an aqueous solution of sodium silicate (replenisher) having an O] of 0.5 to 1.5) to the developer, and further disclosed in Japanese Patent Publication No. 57-7427,₂] / [M] is 0.5 to 0.75 (ie, [SiO₂] / [M₂O] is 1.0 to 1.5), and SiO₂An alkali metal silicate developer having a concentration of 1 to 4% by weight is used, and the alkali metal silicate [SiO 2 used as a replenisher is used.₂] / [M] is 0.25 to 0.75 (ie, [SiO₂] / [M₂O] is 0.5 to 1.5) and both the developer and the replenisher contain at least 20% potassium, based on gram atoms of all alkali metals present therein. A development method consisting of the above is preferably used.
[0120]
The photosensitive lithographic printing plate thus developed is washed with water, surface active as described in JP-A Nos. 54-8002, 55-1115045 and 59-58431. It is post-treated with a desensitizing solution containing a rinse solution containing an agent and the like, gum arabic and starch derivatives. These treatments can be used in various combinations for the post-treatment of the photosensitive lithographic printing plate of the present invention.
[0121]
The planographic printing plate obtained by such processing is loaded on an offset printing machine and used for printing a large number of sheets.
[0122]
As a plate cleaner used for removing stains on the plate during printing, a conventionally known plate plate cleaner for PS plate is used. For example, CL-1, CL-2, CP, CN-4, CG-1, PC-1, SR, IC (made by Fuji Photo Film Co., Ltd.) and the like.
[0123]
EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples.
[0124]
【Example】
An aluminum plate made of material 1S having a thickness of 0.30 mm was used with a No. 8 nylon brush and an aqueous suspension of 800 mesh Pamiston, and its surface was grained and washed thoroughly with water. After being immersed in a 10% aqueous sodium hydroxide solution at 70 ° C. for 60 seconds for etching, washed with running water, neutralized with a 20% aqueous nitric acid solution, and washed with water. This was 300 coulomb / dm in 1% nitric acid aqueous solution using a sinusoidal alternating waveform current under the condition of VA = 12.7V.²Electrolytic surface roughening treatment was performed with the amount of electricity at the time of anode. The surface roughness measured was 0.45 μ (Ra indication). Subsequently, it was immersed in a 30% aqueous nitric acid solution and desmutted at 55 ° C. for 2 minutes, and then the first and second stage anodizing treatments were performed as shown in Table 1.
[0125]
Next, a SG method liquid composition (sol solution) was prepared by the following procedure.
[0126]
The following composition was weighed in a beaker and stirred at 25 ° C. for 20 minutes.
Si (OC₂H_Five)_Four                              38g
3-Methacryloxypropyltrimethoxysilane 13g
85% phosphoric acid aqueous solution 12g
Ion exchange water 15g
Methanol 100g
[0127]
The solution was transferred to a three-necked flask, a reflux condenser was attached, and the three-necked flask was immersed in an oil bath at room temperature. While stirring the contents of the three-necked flask with a magnetic stirrer, the temperature was raised to 50 ° C. in 30 minutes. While maintaining the bath temperature at 50 ° C., the mixture was further reacted for 1 hour to obtain a liquid water composition (sol solution).
[0128]
  This sol solution was diluted with methanol / ethylene glycol = 20/1 (weight ratio) to 0.5 wt%, applied to an aluminum plate with a wheeler, and dried at 100 ° C. for 1 minute. The coating amount at that time is 4 mg / m²Met. The amount of Si was also determined by the fluorescent X-ray analysis method and used as the amount of coating.
[0129]
A high-sensitivity photopolymerizable composition 1 having the following composition was dried on the aluminum plate thus treated with a dry coating weight of 1.5 / m.²And a photosensitive layer was formed by drying at 100 ° C. for 1 minute.
[0130]
Photopolymer composition 1
Tetramethylol methane tetraacrylate 1.5g
Linear organic polymer (B1) 2.0g
[Chemical formula 2]
Sensitizer (C1) 0.15 g
[Chemical Formula 3]
(Λmax THF 479 nm, ε = 6.9 × 10^Four)
Photoinitiator (D1) 0.2g
[Formula 4]
IRGACURE 907 (E1) (Ciba-Geigy) 0.4g
[Chemical formula 5]
ε-phthalocyanine / (B1) dispersion 0.2 g
Fluorine nonionic surfactant Megafac F177 0.03g
(Dainippon Ink Chemical Co., Ltd.)
Methyl ethyl ketone 9.0g
Propylene glycol monomethyl ether acetate 7.5g
Toluene 11.0g
[0131]
A dry coating weight of 2.5 g / m of an aqueous solution of 3% by weight of polyvinyl alcohol (saponification degree: 98 mol%, polymerization degree: 500) was applied on the photosensitive layer.²And dried at 120 ° C. for 3 minutes to obtain a photopolymerizable lithographic printing plate.
[0132]
These plates were exposed to 2 to 1 to 99% in increments of 1% under conditions of 4000 dpi and 175 lines / inch using XLP4000 (Ar laser 75 mW, 488 nm) manufactured by Optronics. Thereafter, it was exposed to 120 ° C. for 20 seconds and subjected to post-heating treatment.
[0133]
Development was performed by immersing in the following developer at 25 ° C. for 30 seconds.
(Developer)
1K potassium silicate 30g
Potassium hydroxide 15g
The following compound 3g
[Chemical 6]
1000g of water
[0134]
Next, GU-7 (manufactured by Fuji Photo Film Co., Ltd.) gum solution was diluted twice with water to treat the plate surface.
[0135]
For printing evaluation, SORKZ manufactured by Heidelberg was used as a printing machine, and Kraf G (N) manufactured by Dainippon Ink was used as ink. As the plate cleaner, acidic PS plate cleaner CL-2 (manufactured by Fuji Photo Film Co., Ltd.) was used. CL-2 was soaked into a printing sponge on the 5000th sheet from the start of printing, and the halftone dot portion was wiped to wash the ink on the printing plate surface. Thereafter, the ink on the printing plate was similarly cleaned with CL-2 for every 10,000 sheets up to the 195,000th sheet, and 150,000 sheets were printed. The reproducibility of highlights was visually evaluated on the obtained printed matter. Each sample was exposed and developed and printed, and the stain (inking) property of the non-image area was also visually evaluated. Further, the dissolution amount of the anodized film was calculated from the change in the weight of the printing plate support, while the pore diameter of the micropores was accelerating with a scanning electron microscope S-900 manufactured by Hitachi, Ltd. The broken surface of the anodized film was observed to determine the average pore diameter of the micropores. The results are shown in Table 1.
[0136]
[Table 1]
[0137]
【The invention's effect】
As described above, according to the present invention, the photosensitive layer and the support are firmly adhered to each other, and it is a highlight even if the ink on the printing plate is removed with a high sensitivity and acidic plate cleaner or a large amount of printing is performed. It is possible to provide a laser-writable photopolymerizable lithographic printing plate that does not fly, has excellent shadow reproducibility, has printing durability, and does not become dirty even when forced to age.

Claims (10)

The roughened aluminum plate, without anodized by or alkali treatment after the alkali treatment as a first step, the pore diameter than the micropores on the anodized film of the first step as a second step obtained but a small diameter of 80% to 5% Ri, and anodic oxidation coating weight of the first stage is again treated anodized in a second stage of the anodized film weight equivalent amount or less and Do that conditions than A support for a lithographic printing plate having an anodized film on the surface The roughened aluminum plate was anodized As a first step, subsequently again anodized at reduced conditions in the radial pore diameter is 80% to 5% than the micropores of the first stage as the second step A method for producing a support for a lithographic printing plate, characterized in that the anodized film is not removed after the treatment The roughened aluminum plate was anodized as a first step, after expanding the micropores present in said coating is dissolved by the anodic oxide film of the first stage is treated with an alkaline aqueous solution, said micropores A method for producing a support for a lithographic printing plate, characterized in that the second stage anodizing treatment is performed under conditions where the pore diameter is smaller than The method for producing a lithographic printing plate support according to claim 3, wherein the anodized film is not removed after the second stage anodizing treatment. The method for producing a lithographic printing plate support according to any one of claims 2 to 4, wherein the first stage anodizing treatment is carried out in an aqueous solution of sulfuric acid, phosphoric acid or oxalic acid.   The method for producing a lithographic printing support according to claim 2, wherein the first stage anodizing treatment is carried out in an aqueous solution of phosphoric acid or oxalic acid, and the second stage anodizing treatment is carried out in an aqueous solution of sulfuric acid.   4. The method for producing a lithographic printing plate support according to claim 3, wherein the first stage anodizing treatment is carried out in an aqueous solution of sulfuric acid, and the second stage anodizing treatment is carried out in an aqueous solution of sulfuric acid. The lithographic printing plate support obtained by the method of any of the lithographic printing plate support according to claim 2-7, photosensitive lithographic printing plate obtained by laminating a photopolymerizable composition as the photosensitive layer The photosensitive lithographic printing plate according to claim 8, further comprising an oxygen-blocking protective layer laminated on the photosensitive layer. 9. The photosensitive lithographic printing plate according to claim 8, which is laser writable.