JPH10211771A - Plate material for offset printing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a hydrophilic non-image layer, which is low in price and excellent in plate wearability and non-image properties by a method wherein a hydrophilic layer made of a hydrophilic substance, which contains a specified amount or more of primary amino group and in which a specified amount or more of the primary amino group is converted to a salt of mineral acid, is provided on a base material. SOLUTION: In order to manufacture a hydrophilic substance, which contains 8 milli-equivalent/gr or more of the sum of primary amino group and mineral-acid-salt- converted primary amino group and 70 equivalent % or more of the total sum of the groups is the mineral-acid-salt-converted primary amino group, the use of the following primary amino group-containing hydrophilic polymer is favorable form the view point of the ease of the acquisition of raw material. As primary amino group- containing hydrophilic polymer, polyallyl amine, hydrazide polyacrylate, poly(2- aminoethyl acrylate), polyvinylamine or the like is exampled and as preferable primary amino group-containing hydrophilic polymer, polyallyl amine or hydrazide polyacrylate is exampled. As far as non-image properties are demonstrated by being modified to a mineral acid salt, either primary amino group-containing hydrophilic homopolymer or primary amino group-containing hydrophilic copolymer causes no trouble as the primary amino group-containing hydrophilic polymer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a printing plate used for an offset printing plate.

[0002]

2. Description of the Related Art In general, an offset printing plate receives a hydrophilic non-image portion which receives water from a dampening solution supply means but does not receive oily ink from an ink roll during printing, and receives oily ink from an ink roll. And a lipophilic image section. Various combinations for expressing such a hydrophilic non-image portion and a lipophilic image portion are known, but as a general example, after the surface is degreased, mechanically or chemically roughened, and then anodized. Further, there is known an aluminum sheet having an lipophilic image portion formed on an aluminum sheet which has been subjected to various surface treatments such as a water glass treatment as necessary. Such a method is described in, for example, Teruhiko Yonezawa, "PS Version Overview", Printing Society, 1993, pp. 18-35.
It is also known that steel or stainless steel is roughened instead of aluminum. In the case of the former aluminum sheet, although it is frequently used, there are problems that the production equipment is large and that aluminum as a raw material is expensive. The latter steel is inexpensive but easily rusted, and thus is not suitable for offset printing using water. Also, the workability was not good because it was heavier than the aluminum sheet. Although stainless steel has been improved in terms of rust, it still has problems in terms of weight.

[0003] In addition to metal materials, examples of components constituting a hydrophilic non-image portion include polyvinyl alcohol, starch, and the like.
It is known that a hydrophilic polymer such as hydroxyethylcellulose, carboxymethylcellulose, casein, gelatin, polyvinylpyrrolidone, vinyl acetate-crotonic acid copolymer, styrene-maleic acid copolymer is cross-linked and insolubilized. In this case, if necessary, silica,
Inorganic pigments such as calcium carbonate may be added. In some cases, it is reinforced with a waterproofing agent. These materials have a problem that water resistance is insufficient and printing durability is poor, or printing durability is low but non-image quality is poor.

Further, a surface layer is formed by using zinc oxide, which is known as an electrophotographic offset master, and a binder resin such as an acrylic resin, a silicone resin and an alkyd resin, and the toner is fused by an electrophotographic method. After the image area is formed, the surface on which the toner is not adhered is desensitized with a desensitizing liquid (etching liquid) containing phosphoric acid, phosphate, potassium ferrocyanide, phytic acid, and a surfactant. One that forms a non-image portion by performing the process is known. These prints have poor printing durability in both non-image areas and image areas, and are limited to applications with a small number of print copies such as light printing.

[0005] As a method for solving the problems of the above-mentioned materials forming a non-image portion other than a metal material, various methods using an acrylamide polymer in a non-crosslinked or crosslinked form have been proposed. For example, JP-A-48-83902, JP-A-53-17406, and JP-A-53-17407
JP-A-53-17408, JP-A-54-17408
6602 and JP-A-54-6603. However, these methods have problems such as insufficient water resistance or extremely narrow substrate compatibility. In order to improve this point, a lithographic printing plate comprising a non-image portion using a copolymer containing acrylamide, an addition-polymerizable unsaturated carboxylic acid and an epoxy-containing addition-polymerizable unsaturated compound has been proposed ( JP-A-59-67097
No.). Although this product exhibited printing durability due to crosslinking, the problem of residual acrylamide monomer in the polymer,
Since a carboxyl group and an epoxy group are contained in the same polymer, they have a problem in storage stability that they react to cause polymer insolubilization.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide an offset printing plate material having a hydrophilic non-image layer which is inexpensive and has excellent printing durability and non-image properties.

[0007]

Means for Solving the Problems The present inventors have developed a hydrophilic layer comprising a hydrophilic substance containing a primary amino group in an amount of at least 8 meq / gr and at least 70 equivalent% of the primary amino group is mineralized. It has been found that the above-mentioned problems can be solved by providing a substrate on a substrate, and the present invention has been completed. That is, the present invention is as follows. (1) The hydrophilic non-image layer provided on the base material contains at least 8 meq / gr of the primary amino group and the mineralized primary amino group in total, and A plate material for offset printing, comprising a hydrophilic substance in which 70% by weight or more of the total amount of the primary amino groups is a mineralized primary amino group. (2) The hydrophilic substance according to the above (1), wherein the hydrophilic substance is composed of a mineral acidified primary amino group-containing hydrophilic polymer having a number average molecular weight of 1.5 × 10 ³ to 1 × 10 ^6. Plate material for offset printing. (3) The plate material for offset printing according to the above (1), wherein the primary amino group-containing hydrophilic polymer is any one of polyallylamine and polyacrylic hydrazide. (4) An offset printing plate material comprising an anchor layer between the substrate of the offset printing plate material of (1) and the hydrophilic non-image layer. (5) The offset printing plate material according to the above (1) or (4), wherein the hydrophilic substance forming the hydrophilic non-image layer is crosslinked using a crosslinking agent. (6) a glycidyl compound having a bifunctional or higher crosslinking agent,
The plate material for offset printing according to the above (5), which is at least one selected from compounds belonging to (meth) acrylic compounds and polybasic acid compounds. (7) The offset printing plate material according to the above (5) or (6), wherein the crosslinking agent is a compound containing at least one of each of two types of glycidyl groups and (meth) acryl groups. (8) Compounds each containing at least one of two types of glycidyl group and (meth) acryl group are glycidyl acrylate, glycidyl methacrylate, glycidyl-α-
(7) characterized in that it is chloroacrylate.
Plate material for offset printing.

Hereinafter, the present invention will be described in detail. The printing plate material for offset printing of the present invention is obtained by forming a hydrophilic non-image layer made of a hydrophilic substance on a base material, and the hydrophilic substance contains a primary amino group in an amount of 8 meq / gr or more. obtained by a mineral acid chloride over 70 equivalent percent of the primary amino groups of substances. That is, 8 meq /
The substance containing more than 70 gr of the primary amino group
It is obtained by treating with a mineral acid equivalent to equivalent% or more.

In the present invention, the total content of the primary amino group and the mineralized primary amino group in the hydrophilic substance must be at least 8 meq / gr,
It is preferable to contain 9 meq / gr or more. If the amount is less than 8 meq / gr, the non-image properties will be insufficiently developed depending on the printing conditions. The upper limit of the content may be used within a range that does not hinder adhesion to lipophilic image components by various methods described later, and it depends on the image forming method, but is usually 25 meq / gr or less. It is.

In the present invention, the numerical value of the primary amino group in the hydrophilic substance is 10 ° C. at 40 ° C. under a reduced pressure of less than 1 mmHg.
It is defined by the amino group equivalent per unit solid gr remaining after drying for an hour. The primary amino group can be determined by a known method. For example, chemical techniques such as the Hinsberg test, Kjeldahl method, chemical organic elemental analysis based on pyrolysis gas chromatography, physical elemental analysis such as fluorescent X-ray elemental analysis, and infrared spectroscopy And a combination method of these elemental analysis methods and NMR spectroscopy.

Further, when the hydrophilic substance cannot be decomposed and solubilized, for the purpose of improving the accuracy of chemical analysis, for example,
A method of preparing a calibration curve based on crosslinked polyallylamine, in which the amount of primary amino groups is quantified by the above method, and measuring the amount of primary amino groups of the hydrophilic substance can be used in combination. This method is described in a compendium (eg, Morrison Boyd, translated by Takashi Nakanishi et al., “Morrison Boyd Organic Chemistry (Part 2)” (4th edition), Tokyo Kagaku Dojin (1985)). In addition, the quantitative determination of the mineral acid salt of the primary amino group can be performed by first deoxidizing in the presence of a strong base and using the above method.

In the present invention, the total amount of the primary amino group and the mineralized primary amino group is 8 meq / gr or more, and 70 equivalent% or more of the total amount thereof is the mineralized primary amino group. For the production of a certain hydrophilic substance, it is usually convenient to use a primary amino group-containing hydrophilic polymer described below from the viewpoint of obtaining raw materials. Examples of the primary amino group-containing hydrophilic polymer include polyallylamine, polyacrylic hydrazide, poly (2-aminoethyl acrylate), and polyvinylamine. From the viewpoint of obtaining raw materials, polyallylamine and polyacrylic hydrazide are preferred. There is no problem whether the primary amino group-containing hydrophilic polymer is a homopolymer or a copolymer as long as it is modified into a mineral acid salt and exhibits non-image properties.

The number-average molecular weight of the primary amino group-containing hydrophilic polymer used in the present invention is 1.5 × 10 5 from the viewpoint of ease of use when treated with a polymer or a coating composition and printing durability when formed into a lithographic printing plate. The range of ³ to 1 × 10 ⁶ is preferred. From the viewpoint of ease of use, the range of 5 × 10 ^{3 to} 5 × 10 ⁵ is more preferable. Here, the number average molecular weight is a reduced molecular weight determined by the GPC method, and details of the measuring method are described in Examples. Usually, this measurement is performed on the polymer before the mineralization treatment.

In the present invention, at least immediately before printing, 70 equivalent% or more of the primary amino groups contained in the primary amino group-containing hydrophilic polymer as the raw material must be mineralized. When the mineralization ratio is lower than 70 equivalent%, non-image properties may not be exhibited depending on printing conditions. In order to maintain stable non-image properties, 80 equivalent% or more is preferable.

The acidification of a primary amino group is performed by mineralizing a primary amino group-containing hydrophilic polymer as a raw material, or
A predetermined amount of a monomer as a raw material for polymer synthesis is subjected to mineralization and polymerization.Furthermore, after a hydrophilic layer comprising a primary amino group-containing hydrophilic polymer as a raw material is provided on a substrate, mineralization is performed before or after crosslinking. You can do it. Examples of mineral acids used for mineralization include ordinary mineral acids such as hydrochloric acid, sulfuric acid, nitric acid, and phosphoric acid.

The hydrophilic substance forming the hydrophilic non-image layer of the present invention is usually preferably crosslinked immediately before printing in order to secure printing durability. When used only for low-durability printing, crosslinking is not necessary. It is convenient and preferable to carry out crosslinking using a primary amino group. As the cross-linking agent, a compound having two or more (meth) acrylic groups, glycidyl groups or carboxyl groups in the compound can be used, and one or more glycidyl groups and (meth) acrylic groups in the compound can be used. Those containing are preferred. When a compound having only an acrylic group or a glycidyl group is used as a cross-linking agent, and before mixing with a hydrophilic layer, for example, when mixed with a primary amino group-containing hydrophilic polymer solution, the reaction with the amino group is fast, so that gelation is prevented. For the purpose, it is necessary to cool the mixed solution on ice or to mix immediately before the application and apply immediately. When a compound having a methacrylic group is used as a crosslinking agent, it is stable for several hours at room temperature even when mixed. It is preferable to heat and cure after application in order to accelerate the crosslinking reaction. It is sufficient that the heating is performed within a range of several minutes to one hour in the range of 60 to 120 ° C. When a compound having only a carboxyl group as a crosslinkable group is used, the amide forming reaction is performed at a high temperature of 100 ° C. or higher.

As the (meth) acryl group-containing compound which can be used as a crosslinking agent, those having a predetermined number of the above functional groups can be used from known monomers and oligomers described in the following publications. For example, supervision of Kato Kiyomi: Advances in UV curing technology; p423-p465, General Technology Center (1
993), Integrated Technology Center Publishing Division: UV / EB curing technology; p142-p151, Integrated Technology Center (19
83), supervised by Kiyoshi Akamatsu: Practical technology of new photosensitive resin; p1
01-p144, CMC (1987).

Specific examples of polyfunctional (meth) acrylates and polyfunctional glycidyl compounds which are crosslinking agents usable in the present invention, and compounds having both functional groups are shown below. Ethylene glycol diglycidyl ether (meth) acrylic acid 2 mol adduct, propylene glycol diglycidyl ether (meth) acrylic acid 2 mol adduct, tripropylene glycol diglycidyl ether (meth) acrylic acid adduct, 1,6 A (meth) acrylic acid adduct of hexanediol diglycidyl ether, a (meth) acrylic acid 2 mol adduct of glycerin diglycidyl ether,
Tetraethylene glycol diglycidyl ether (meth) acrylic acid 2 mol adduct, polyethylene glycol diglycidyl ether (meth) acrylic acid 2 mol adduct, bisphenol A diglycidyl ether (meth)
Epoxy (meth) acrylates such as acrylic acid 2 mol adduct; glycerin di (meth) acrylate hexamethylene diisocyanate urethane oligomer, glycerin (meth) acrylate isophorone diisocyanate urethane oligomer, glycerin di (meth) acrylate tolylene diisocyanate urethane oligomer, pentaerythritol Urethane (meth) acrylate such as tri (meth) acrylate hexamethylene diisocyanate urethane oligomer; oligoester (meth) acrylate such as tetramethylolmethane tri (meth) acrylate adipate; ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate ) Acrylate, diethylene glycol di (meth) acrylate, dipropylene glycol (Poly) ether (meth) acrylates such as (meth) acrylate, triethylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, and polypropylene glycol di (meth) acrylate; 1 , 6-hexanediol di (meth) acrylate, trimethylolpropane di (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolpropane ethylene oxide adduct triacrylate, dimethylol tricyclodecane di (meth) acrylate, 2,2-bis [4
-(Methacryloxyethoxy) phenyl] propane,
2,2-bis [4- (methacryloxydiethoxy) phenyl] propane, 2,2-bis [4- (methacryloxypolyethoxy) phenyl] propane or its acrylate, tris (2-acryloxyethyl) isocyanurate or its Methacryl body, ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, dipropylene glycol diglycidyl ether, triethylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol di Glycidyl ether, neopentyl glycol diglycidyl ether, trimethylolpropane triglycidyl ether Polyfunctional diglycidyl compounds such as Le; glycidyl (meth) acrylate, acrylic acid 9,
10-epoxidized oleyl, (3,4-epoxycyclohexyl) methyl (meth) acrylate, (3,4-epoxycyclohexyl) ethyl (meth) acrylate,
(3,4-epoxycyclohexyl) propyl (meth)
Compounds containing a glycidyl group and a (meth) acryl group in the same molecule, such as acrylate and glycidyl-α-chloro (meth) acrylate.

The amount of the crosslinking agent to be added may be determined in accordance with the printing durability required for use within a range that does not fall below the required amino group content of the entire hydrophilic substance. Usually, it is used at not more than 40% by weight of the hydrophilic polymer containing primary amino groups. A small amount of a monomer having a carboxyl group or a sulfonic acid group can be used in combination for the purpose of further enhancing non-image properties. Such monomers include, for example, acrylic acid, methacrylic acid, itaconic acid and its half esters, sulfoethyl acrylate,
Sulfoethyl methacrylate, vinyl sulfonic acid and the like can be mentioned.

In addition, known monofunctional monomers other than those described above can be used in a small amount for the purpose of improving affinity, adhesion, and water resistance with a lipophilic image component described later. Specific examples include known (meth) acrylates, itanconates, (meth) acrylamides and derivatives thereof listed in the above publications. Specifically, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, (meth) acryloylmorpholine, N-methyl (meth) acrylamide, N, N-
Dimethyl (meth) acrylamide, N, N-dimethylaminopropyl (meth) acrylamide, N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, N, N-dimethylaminoneopentyl ( Meth) acrylate, N-vinyl-2-pyrrolidone, diacetone acrylamide, N
-Methylol (meth) acrylamide, methoxytriethylene glycol (meth) acrylate, methoxytetraethylene glycol (meth) acrylate, methoxypolyethylene glycol (meth) acrylate (PEG
Number average molecular weight 400), methoxypolyethylene glycol (meth) acrylate (PEG number average molecular weight 10
00), butoxyethyl (meth) acrylate, phenoxyethyl (meth) acrylate, phenoxydiethylene glycol (meth) acrylate, phenoxypolyethylene glycol (meth) acrylate, nonylphenoxyethyl (meth) acrylate, β- (meth) acryloyloxyethyl hydrogen Phthalate, β-
(Meth) acryloyloxyethylhadogen succinate, polyethylene or polypropylene glycol mono (meth) acrylate, 3-chloro-2-hydroxypropyl (meth) acrylate, isobornyl (meth)
Acrylate, lauryl (meth) acrylate, tridecyl (meth) acrylate, stearyl (meth) acrylate, isodecyl (meth) acrylate, cyclohexyl (meth) acrylate, tetrafurfuryl (meth)
Acrylate, benzyl (meth) acrylate, mono (2-acryloyloxyethyl) acid phosphate or its methacrylic body, glycerin monoacrylate, N- (meth) acryloxyoxysuccinimide and the like can be mentioned.

The amount used is required that the hydrophilic non-image layer provided on the substrate contains at least 8 meq / gr of the primary amino group and the mineralized primary amino group in total. In addition, it is limited to a range that does not hinder non-image expression. Therefore, the amount of addition cannot be uniformly defined, but is generally about 20% by weight or less based on the total weight of the primary amino group-containing hydrophilic polymer and the crosslinking agent.

When a polyfunctional methacrylic compound (regardless of monomer, oligomer or polymer) is used as a crosslinking agent, crosslinking is carried out at room temperature and in a short time by using not only a crosslinking reaction by Michael addition but also a crosslinking by radical polymerization. It can also be implemented. As the radical polymerization initiator used at this time, a known polymerization initiator such as a thermal polymerization initiator such as an azo initiator, a peroxide initiator, and a redox initiator, and a photopolymerization initiator can be used. Examples of these are detailed in the initiator-related description part of the publication. Among them, it is preferable to use a photopolymerization initiator from the viewpoint of easy control. Specifically, benzoin, benzoin isobutyl ether, benzoin isopropyl ether, benzophenone, Michler's ketone, xanthone, thioxanthone, chloroxanthone, acetophenone, 2,2-
Dimethoxy-2-phenylacetophenone, benzyl,
2,2-dimethyl-2-hydroxyacetophenone,
(2-acryloyloxyethyl) (4-benzoylbenzyl) dimethylammonium bromide, (4-benzoylbenzyl) trimethylammonium chloride, 2- (3-dimethylamino-2-hydroxypropoxy) -3,4-
Dimethyl-9H-thioxanthon-9-one mesochloride, 4- (2-hydroxyethoxy) phenyl (2
-Hydroxy-2-propyl) ketone, 1-phenyl-
1,2-propanedione-2- (O-benzoyl) oxime, thiophenol, 2-benzothiazole thiol, 2-benzoxazole thiol, 2-benzimidazole thiol, diphenyl sulfide, decyl phenyl sulfide, di-n-butyl disulfide , Dibenzyl sulfide, dibenzoyl disulfide, diacetyl disulfide, dibornyl disulfide dimethoxyxanthogen disulfide, tetramethyl thiuram monosulfide, tetramethyl thiuram tetrasulfide, benzyl dimethyl dithiocarbamate quinoxaline, 1,
Examples thereof include 3-dioxolan and N-laurylpyridinium. From these, what has absorption in the wavelength region of the light source used in the manufacturing process and dissolves or disperses in the solvent used when preparing the dope may be appropriately selected. Usually, those that dissolve in the solvent used are preferred because of their high reaction efficiency.

Examples of the thermal polymerization initiator include methyl ethyl ketone peroxide, cyclohexanone peroxide,
n-butyl 4,4-bis (t-butylperoxy) valerate, 1,1-bis (t-butylperoxy) cyclododecane, 2,2-bis (t-butylperoxy) butane, cumene hydroperoxide , P-menthane hydroperoxide, di-t-butyl peroxide,
t-butylcumyl peroxide, dicumyl peroxide, t-butylperoxylaurate, t-butylperoxyisopropyl carbonate, t-hexylperoxybenzoate, t-butylperoxybenzoate, t-butylperoxyacetate, etc. Azo initiators such as azobisisobutyronitrile and azobisvaleronitrile.

The amount used is 0.01% by weight or more and 10% by weight or less, preferably 0.1% by weight or more,
% By weight or less. As the actinic ray source, known ones such as a metal halide lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, and a chemical lamp can be used. Examples of the heat source include an infrared lamp, a normal nichrome heater, and hot air. The plate material for offset printing of the present invention is provided with a mixture of the above-mentioned primary amino group-containing hydrophilic polymer, crosslinking agent and other additives on a base material to a certain thickness according to a known method, It is obtained by providing a mixture with a crosslinking agent and other additives on a base material to a certain thickness, which is a known method, using a primary amino group-containing hydrophilic polymer obtained by salification or mineralization. .
Specifically, the mixture solution or dispersion liquid is coated on a substrate by a coating method such as roll coating, blade coating, spray coating, bar coating, curtain coating, or provided by forming a film on the substrate by a casting method. There is a method.

As a solvent for dissolving or dispersing the mixture, most solvents such as water, toluene, ethyl acetate, methyl ethyl ketone, tetrahydrofuran, acetonitrile, and mixed solvents mainly containing these can be used unless they have a high boiling point. it can. Water is preferred for application in a dissolved state. Even when water is used, a small amount of a solvent having solubility in water may be added for controlling the evaporation rate. When applying in a dispersed state, a known surfactant such as a nonyl or octylphenol ethylene oxide adduct, sodium linear alkylbenzene sulfonate, or a pluronic detergent may be used in a small amount in order to stabilize the dispersion. Although the polymer thickness is not particularly limited, a range of 0.01 μm to 100 μm is applied. Usually, it is in the range of 0.5 μm to 10 μm.

As the base material, a sheet such as steel, aluminum, plastic, or water-resistant paper provided with an anchor layer as necessary for obtaining a printing durability or a polymer film having a uniform thickness is used. The anchor layer can be provided by applying an adhesive of acrylic type, urethane type, cellulose type, polyallylamine type or the like. The thickness of the anchor layer is not particularly limited as long as it is provided uniformly, but it is sufficient that the anchor layer is applied in the range of 0.1 to 3 μm on average. Usually, it is applied at about 1 μm.

To the hydrophilic substance forming the hydrophilic non-image layer of the present invention, known additives such as dyes, silica gels and pigments such as magnesium carbonate can be added as long as the non-image properties are not impaired. Since the amount of addition differs depending on the primary amino group-containing hydrophilic substance and the crosslinking agent used, it cannot be specified unconditionally. However, the hydrophilic substance is composed of 8 meq / gr. The content may be set as long as the content is contained and the image is printed under the actually used printing conditions and the non-image property is maintained.

The total content of the hydrophilic substance, the cross-linking agent, the additives, and the like in the coating solution containing them is determined based on the substrate to be coated or the substrate provided with the anchor layer (hereinafter, referred to as a support).
In general, the amount is suitably in the range of 0.5 to 80% by weight, although it depends on the coating method. The coating solution thus prepared is applied to a substrate, dried, and subsequently subjected to the crosslinking treatment.
The cross-linking treatment may be performed at any stage before printing, and can be set in accordance with the coordination with the coating device and the image forming unit. Usually, after coating and drying, a crosslinking treatment is performed. When thermal crosslinking is employed, drying and heating can be performed after application.

The offset printing plate material of the present invention comprises a lipophilic image portion formed on the hydrophilic layer of the offset printing plate material,
On the other hand, by forming the hydrophilic non-image portion with a hydrophilic layer, it is used as an offset printing plate. When an offset printing plate material that is not cross-linked is used, the cross-linking treatment is performed at any stage before printing as described above. Hereinafter, a method of forming an lipophilic image portion on an offset printing plate material to produce an offset printing plate will be described. 1) A known photosensitive layer of a positive type (a region irradiated with light is solubilized) or a negative type (a region irradiated with light is insolubilized) is provided on a hydrophilic layer provided on a base material, and image forming exposure is performed through an image carrier film. Or direct exposure and drawing with a laser based on digital data, removing the photosensitive layer dissolved with a developing solution, exposing the hydrophilic layer, and forming a hydrophilic non-image portion. The photosensitive layer not removed by the development process forms an oleophilic image area. Thus, an offset printing plate is created. 2) A thermosetting lipophilic thermosensitive layer is provided on the hydrophilic layer provided on the base material, and image drawing exposure is performed with a laser, an uncured portion is washed out and removed, and the hydrophilic layer is exposed to form a non-image portion. The cured layer becomes the lipophilic image area. Thus, an offset printing plate is created. 3) A lipophilic layer is provided on the hydrophilic layer provided on the base material, and a non-image equivalent region is formed by drawing on the lipophilic layer with a laser and ablating the lipophilic layer with a laser to expose the lower hydrophilic layer. I do. The area that has not been abraded becomes the lipophilic image area. Using a photocurable lipophilic layer, reduce the energy required for abrasion by exposing the entire surface after abrasion without cross-linking before abrasion, and improving the mechanical strength of the lipophilic layer by exposure after drawing You can do it.
Thus, an offset printing plate is created. 4) An lipophilic image portion can be formed by directly drawing, printing, transferring, and typing on the hydrophilic layer provided on the base material using ink or paint, and an offset printing plate can be prepared. More specifically, there are a method of drawing an image by an ink jet method, and a method of performing thermal transfer with a laser or a thermal head via a tape or sheet as a transfer layer using a sublimable material or a heat-fusible material. When a photosensitive material is used as the heat-fusible material, the image portion can be reinforced by exposing the transferred portion over the entire surface, and the printing durability can be significantly improved. 5) An offset printing plate can be formed by forming a lipophilic image portion by heat-sealing a toner by electrophotography on a hydrophilic layer provided on a base material.

The plate material for offset printing of the present invention can be used for short-run printing and also for proof printing in addition to ordinary offset printing. The proof printing plate preparation includes an analog exposure method through an image carrier film and a method of directly drawing image data as a digital signal. Recently, a direct digital system that does not output a film has attracted attention. The offset printing plate material of the present invention is also effective in this method.

[0031]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described more specifically with reference to examples. Unless otherwise noted, parts are parts by weight and% is weight &. The number average molecular weight of the primary amino group-containing hydrophilic polymer used in the present invention was measured by the GPC method as follows. Equipment: TRI-ROTARVI manufactured by JASCO, Column: SB-804HQ
One, Guard column: One SB-G, Eluent: Na
NO ₃ 50 mM aqueous solution, column temperature: 30 ° C., flow rate:
0.5 ml / min, detector: RI, calibration curve preparation standard: PEG-PEO.

[0032]

Example 1 (1) Preparation of Coating Solution In a separable flask, a polyallylamine aqueous solution (PAA manufactured by Nitto Boseki Co., Ltd.) was used as a primary amino group-containing hydrophilic polymer.
-10C, 10% aqueous solution) 151.7 gr, glycidyl methacrylate (hereinafter abbreviated as GMA) as a crosslinking agent
3.8 gr was added and stirred at 40 ° C. for 2 hours. The number average molecular weight of polyallylamine was about 7 × 10 ³ . It was confirmed that residual GMA was not detected by gas chromatography. Next, 36% hydrochloric acid was added in an amount required to neutralize 80 equivalent% of amino groups, followed by stirring. As a photopolymerization initiator, a coating solution was prepared by adding (2-acryloyloxyethyl) (4-benzoylbenzyl) dimethylammonium bromide (hereinafter abbreviated as ABQ) in an amount of 5% based on the solid content and a small amount of acetone. . The content of primary amino groups and primary amino groups hydrochlorinated determined by the Kjeldahl method is about 9.2.
It was meq / g of solids. (2) Preparation of Plate Material The coating solution having the above composition was applied to a degreased aluminum plate having a thickness of 0.24 mm with a bar coater and dried at 50 ° C. for 30 minutes. Then, ultraviolet exposure under a nitrogen atmosphere (exposure amount:
7 J / cm ² ) A plate material for offset printing was prepared (thickness of coating layer: 3 μm). (3) Preparation and printing of a printing plate A glycidyl methacrylate was added to a polyacrylic acid-styrene copolymer produced according to Example 1 described in JP-B-49-34041 by 68 mol% based on a carboxyl group. 100 parts of an acrylic resin having an unsaturated group in the side chain obtained as described above, 25 parts of tetramethylolmethanetetramethacrylate as a monomer, 0.9 part of 1,2-benzanthraquinone as a photopolymerization initiator, and 0.1 part of benzoin methyl ether. The photosensitive resin consisting of (2)
Was applied using a bar coater so that the thickness after dry application was 1.5 g / m ² to provide a photosensitive layer. Next, a negative film was brought into close contact with the surface of the photosensitive layer, and exposed to a water-cooled high-pressure mercury lamp at a distance of about 1 m for 90 seconds.
Developing with a developing solution consisting of 10 parts of methanol and 100 parts of water, removing the unexposed portion of the photosensitive layer, forming a hydrophilic non-image portion and a lipophilic image portion to prepare an offset printing plate. The obtained printing plate is transferred to an offset printing machine (HAMADA 611XL).
A) and attached to a fountain solution (Fuji Photo Film Co., Ltd.)
U-3, 100-fold dilution) and ink (GEOS-G, manufactured by Dainippon Ink and Chemicals, Incorporated, GEOS-G) were used to print on high quality paper. done.

[0033]

Example 2 (1) Preparation of Coating Solution Polyacrylic acid hydrazide (manufactured by Otsuka Chemical, PAH-L, containing 40 mol% of acrylamide units) as a primary amino group-containing hydrophilic polymer in a separable flask containing 100 gr of water. 16 gr was added and dissolved by stirring. The number average molecular weight of polyacrylic hydrazide was about 3 × 10 ³ . Then, 36% hydrochloric acid was added to neutralize more than 90 equivalent% of primary amino groups. Thereafter, the periphery of the flask was cooled with ice water, 1.8 g of diglycidyl ether of PEG400 was added as a crosslinking agent, and the mixture was rapidly stirred to obtain a coating solution. The content of primary amino groups and hydrochloric acid-converted primary amino groups determined by the Kjeldahl method is about 9.6 meq /
The solid content was 1 gr. (2) Preparation of plate material The cooling coating solution obtained in (1) was applied on a 100 μm-thick polyester sheet having been subjected to corona discharge treatment with a bar coater, air-dried at room temperature, and further dried at 50 ° C. for 1 hour.
The plate was cured to prepare an offset printing plate (thickness of a coating layer: 2.0 μm). (3) Preparation and printing of printing plate The offset printing plate material obtained in (2) was attached to a thermal printer using a hot-melt transfer ribbon, and an image was drawn. In this way, an offset printing plate was prepared in which the area drawn with the hot-melt transfer material formed an oleophilic image area and the area not drawn formed a hydrophilic non-image area. When the obtained printing plate was printed under the printing conditions used in Example 1, a printed matter without background smear was obtained. In the non-image area, no background dirt was generated even after 10,000 copies.

[0034]

Comparative Example 1 (1) Production of Polymer In a separable flask, a polyallylamine aqueous solution (manufactured by Nitto Boseki, PAA) was used as a primary amino group-containing hydrophilic polymer.
-10C, 10% aqueous solution) 151.7 gr, GMA 3.8 gr as a cross-linking agent, and glycidol 9 gr were added, and 40
C. and stirred for 2 hours. GM remaining by gas chromatography
A, it was confirmed that glycidol was not detected. Next, 36% hydrochloric acid was added in an amount required to neutralize 80 equivalent% of amino groups, followed by stirring. (2-acryloyloxyethyl) (4-benzoylbenzyl) dimethylammonium bromide (hereinafter abbreviated as ABQ) as a photopolymerization initiator 5% of the solid content and a small amount of acetone were added to obtain a coating solution. The content of primary amino groups and hydrochloric acid-converted primary amino groups determined by the Kjeldahl method was about 3.5 meq / g of solids. (2) Preparation of printing plate material, printing plate and printing Using the polymer obtained in (1), an offset plate material was prepared in the same manner as in Example 1, and then an image was formed to prepare a printing plate. From 100 copies or less, background stains occurred in the non-image portion, and the printing durability of the non-image portion was insufficient.

[0035]

The offset printing plate prepared by using the offset printing plate material of the present invention has excellent ink repellency and is comparable to an anodized aluminum support usually used as a non-image portion in offset printing. Demonstrate the non-image performance of printing durability. In particular, excellent ink repellency is exhibited not only in the printing field using ordinary kneading ink but also in printing using ink having much lower viscosity than kneading ink such as offset ink for newspaper.

Claims (8)

[Claims] Claims: 1. A hydrophilic non-image layer provided on a substrate,
The total amount of the primary amino group and the mineralized primary amino group is 8 meq / gr or more, and 70% by weight or more of the total amount of the primary amino group and the mineralized primary amino group is mineralized. A plate material for offset printing, comprising a hydrophilic substance that is a primary amino group. 2. The method according to claim 1, wherein the hydrophilic substance is mineralized and number averaged.
Child size is 1.5 × 10 ^Three~ 1 × 10⁶Contains primary amino group
A contractor characterized by being composed of a hydrophilic polymer
The plate material for offset printing according to claim 1. 3. The offset printing plate material according to claim 2, wherein the primary amino group-containing hydrophilic polymer is any one of polyallylamine and polyacrylic hydrazide. 4. An offset printing plate material, comprising an anchor layer between the substrate of the offset printing plate material of claim 1 and a hydrophilic non-image layer. 5. The offset printing plate material according to claim 1, wherein the hydrophilic substance forming the hydrophilic non-image layer is cross-linked using a cross-linking agent. 6. The offset printing plate according to claim 5, wherein the crosslinking agent is at least one compound selected from glycidyl compounds, (meth) acrylic compounds, and polybasic acid compounds having two or more functional groups. Wood. 7. The printing plate material for offset printing according to claim 5, wherein the crosslinking agent is a compound containing at least one of two types of glycidyl group and (meth) acryl group. 8. A glycidyl group and a (meth) acryl group
8. The printing plate material for offset printing according to claim 7, wherein the compound containing at least one kind group is glycidyl acrylate, glycidyl methacrylate, or glycidyl-α-chloroacrylate.