JPH0333745A - Planographic printing plate and production thereof - Google Patents

Abstract

PURPOSE:To maintain the ink receptability of a line drawing part and to improve printing resistance by adhering a resin layer having affinity to ink and a cured film layer of organosiloxane respectively onto a substrate. CONSTITUTION:After the line drawing part consisting of the resin layer 5 having affinity to ink is provided on the substrate 1, an organosiloxane soln. having repellency is applied on this line drawing part and is cured to form the non- image part consisting of the cured layer 3 of the organosiloxane. The substrate having pore resistance or the substrate provided with a coating layer contg. inorg. powder is effective to improve the adhesiveness to the cured film layer of the organosiloxane having a poor adhesiveness. The ink receptivity and printing resistance of the image part are improved in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a lithographic printing plate that does not require dampening water and a method for manufacturing the same, and more specifically relates to a lithographic printing plate with extremely high rigidity resistance. The purpose is to provide a version.

<Prior art and its problems> Lithographic printing has many advantages compared to letterpress printing and intaglio printing, and currently occupies the mainstream of printing methods. However, since lithographic printing uses dampening water, there are many problems such as: (1) Emulsification of ink by the dampening water; (2) Variation in printing density; (2) Expansion and contraction of paper due to the dampening water. In order to fundamentally solve these problems related to dampening water, attempts have been made to develop printing plates for lithographic printing that do not use dampening water. Lithographic printing plates that do not use dampening water have high printing density because the ink is not emulsified by the dampening water.

■Color density is stable because there is no need to adjust the amount of dampening water.

■Since no dampening water is used, there is no expansion or contraction of the paper and the paper has a high level of accuracy.

There are other benefits.

However, none of the printing plates for lithographic printing that do not use dampening water known to date have sufficient properties for practical use.

For example, a diazo photosensitive layer made of a diazo type photosensitive &[l acid] and a dimethylpolysiloxane rubber layer are formed on a substrate such as an aluminum plate, and then a positive film is layered on top of the layer and exposed. A method of insolubilizing the diazo photosensitive layer in the exposed areas, removing the diazo photosensitive layer in the non-exposed areas by development treatment, and then peeling off the dimethylpolysiloxane rubber layer in the non-exposed areas (Tokukō Sho 4).
4-23042), or a diazo photosensitive layer, an adhesive layer, and a silicone rubber layer are sequentially formed on a substrate such as an aluminum plate, and then a negative film is superimposed thereon and then exposed to light. A method of obtaining a printing plate for lithographic printing by developing the photosensitive layer using photolysis and then peeling off the silicone rubber layer in the exposed area (
(see Japanese Patent Publication No. 44-23042) is known.

However, in all of these methods, the adhesion between the silicone rubber layer and the photosensitive layer or between the silicone rubber layer and the adhesive layer is extremely poor, and the printing durability of the lithographic printing plate is extremely low. Because there is a non-photosensitive silicone rubber layer between the film and the film, the pattern appearing on the positive or negative film cannot be accurately reproduced, and peeling off the silicone rubber layer requires dissolving the photosensitive layer in a solvent. Since the silicone rubber layer utilizes a change in its properties, the image formed by the silicone rubber layer after being peeled off has a large drawback in that the edges are not sharp and the image is not sharp. Moreover, this manufacturing method produces 2 to 3 J on the substrate!
Since the process involves sequentially overlapping exposure and development, it has the disadvantage of being complicated to operate.

In addition, a method for producing a printing plate for lithographic printing by coating photosensitive silicon on a substrate, then exposing and developing it is described by Kao Inoue and Atsumi Noshiro in the Proceedings of the Japan Society of Printing.

19.19. (1980). This method has the advantage that it is easy to manufacture a printing plate for lithographic printing, but the silicon layer must satisfy both photosensitivity and ink repellency, and it is still difficult to obtain a printing plate for lithographic printing that is suitable for practical use. do not have.

Furthermore, there is a method in which an uncured silicon layer is provided on a substrate, a toner image is formed thereon by electrostatic photography, and then the silicon layer is cured (Yamama, Printing Magazine, 60.2.9 (197
In this method, the adhesion between the ink-philic toner and the silicon layer is extremely poor, and the rigidity of the lithographic printing plate is low.

In addition, a metal-containing organosiloxane cured 1 in which a non-image area consisting of an organosiloxane cured film layer and a surface of the organosiloxane cured film layer are metallized in a pattern on the substrate.
A printing plate for lithographic printing (see Japanese Patent Publication No. 61-58822) having an image area consisting of 11 layers is known. This method is considered to be an excellent method since the adhesion between the image area and the non-image area and the interface between the substrate and the silicon layer is good. However, there is little difference between the ink receptivity of the image area made of the metal-containing cured organosiloxane layer and the ink receptivity of the non-image area made of the organosiloxane cured layer, resulting in background smudges and decreased print density of printed matter. In addition to these drawbacks, the metallized cured organosiloxane film peels off between the eyebrows, unevenness occurs on the surface of the N-line portion, and the rigidity is low.

<Problems to be Solved and Attempted by the Invention> The present invention solves the above-mentioned drawbacks of conventional lithographic printing plates that do not use dampening water, that is, maintains ink receptivity in the image area and A printing plate for lithographic printing that can be put to practical use by strengthening the adhesion between the silicon layer forming the image area and the substrate, and between the ink-philic resin layer forming the image area and the substrate and improving the rigidity. This was done for the purpose of providing a manufacturing method.

Means for Solving the Problems> The present invention has been made in view of the above-mentioned current situation, and specifically, the present invention has been made in view of the above-mentioned current situation. This is a printing plate for lithographic printing, which has a non-printing area as shown in FIG.

Furthermore, the present invention provides a method of providing an image area made of an ink-philic resin layer on a substrate, and then applying a repellent organosiloxane solution to the image area and curing it to form a non-image area. After manufacturing a printing plate for lithographic printing and providing a non-image area made of an organosiloxane cured film layer on the substrate, a solution containing a repellent ink-philic resin is applied to the non-image area and then dried. , which is characterized by manufacturing a printing plate for lithographic printing by forming an image area made of an ink-philic resin layer.

<Detailed Description of the Invention> The present invention will be described in more detail below based on the drawings. 1st
2 are partially enlarged sectional views schematically illustrating the bottom of the gutter of the printing plate for lithographic printing of the present invention.

An image area consisting of an ink-philic resin layer (5) and a non-image area consisting of an organosiloxane cured film layer (3) form a substrate (1).
Each is firmly glued to the top. Here, in FIG. 1, the organosiloxane cured film layer (3) is lower in height than the ink-philic resin layer (5), forming a so-called planar relief plate. FIG. 2 shows a gutter bottom in which the ink-philic resin layer (5) and the cured organosiloxane film N (3) are equal in height.

Next, a method for manufacturing a printing plate for lithographic printing according to the present invention will be explained. After providing an image area made of an ink-philic resin layer (5) on the substrate (1), a repellent organosiloxane solution is applied to the image area and then cured to form an organosiloxane cured film layer (3). A non-printing area is formed. In addition, as another manufacturing method, after providing a non-image area made of an organosiloxane cured film layer (3) on the substrate (1), this non-image area contains an ink-repellent ink-philic resin. After the solution is applied, it is dried to form an image area made of a visual ink resin layer (5).

Here, as the substrate (1), substrates used in conventional planographic printing plates, such as polyethylene laminate paper, coated paper, art paper, coated paper, and aluminum foil, which have dimensional stability, can be used. In particular, a porous substrate or a substrate provided with a coating layer containing an inorganic powder is effective in improving the adhesion to the organosiloxane cured film layer, which has poor adhesion. In addition, halogen-substituted alkyl groups, hydroxyl groups, and carboxyl groups can be prepared using silane coupling agents and the like.

In a substrate into which a functional group that can be polycondensed with an amino group ring organosiloxane is introduced, the above-mentioned functional group and the organosiloxane are polycondensed, and the adhesiveness with the cured organosiloxane film layer is improved. Alternatively, by treating the substrate with a surfactant such as a silicone surfactant, the wettability between the substrate and the organosiloxane is improved, and the adhesion between the substrate and the organosiloxane cured film layer is improved.

In addition, as a method for producing the image area made of the ink-philic resin layer (5), conventionally proposed methods for producing printing plates for lithographic printing can be applied, such as a method using a photosensitive resin or a transfer method. A method using an electrophotographic method is effective. In the method using a photosensitive resin, the resin is uniformly coated onto the substrate (1) to a thickness of about 5 to 30 μm, and then patterned by exposure and development. The photosensitive resin used here is
Conventionally known cinnamic acid photosensitive resins (TRP manufactured by Tokyo Ohka Co., KPR manufactured by Kodak, etc.), cyclized rubber photosensitive resins (OMR manufactured by Tokyo Ohka Co., Ltd., etc.), diazo photosensitive resins (
Commercially available photosensitive resins such as AZ manufactured by Supre, OFMRP manufactured by Tokyo Ohka, etc., or photosensitive materials capable of forming a film are used.

In addition, the method of forming by a transfer method is to apply the above-mentioned photosensitive resin to an olefin resin film, fluororesin film, silicone coated film, etc., then expose and develop the pattern, and then transfer the entire surface to the substrate (1). There is a method of forming the ink-philic resin layer (5), or a method of forming the ink-philic resin layer (5) with a thermal head or the like using a transfer ribbon coated with an ink-philic resin on a film. The ink-philic resin used must have good ability to accept printing ink, and is determined by the type and characteristics of the ink used for printing, but acrylic acid resins, methacrylic acid resins,
Known resins such as urethane resins, rubber resins, copolymers and polymer blends of these resins are used. Furthermore, as a method for applying organosiloxane, if necessary, after diluting with an appropriate diluting solvent such as benzene, toluene, n-hexane, etc., spin coater method, reverse coater method, slide coater method, bar coater method, etc.
There are dipping methods, screen printing methods, etc., and by applying these methods and heating, the organosiloxane cured film layer (3) is obtained. The organosiloxane used here is
It has good adhesion to the substrate (1) mentioned above, compared to the ink-friendly resin layer (5) mentioned above! The substrate (1) and the ink-philic resin layer (5) must have a property and have strong ink repellency.
For example, various heat-curing silicones containing dimethylpolysiloxane as the main component are preferable.Thermosetting silicones include -molded and two-component types; Curing is -3l-OH, -31-O
It is based on a crosslinking reaction by dehydration condensation, dehydrogenation condensation, addition polymerization, etc. of organosiloxanes having reactive groups such as R, -5i-H, -S 1-CH-CH, etc. In addition, - hardening by mold-making reacts with moisture in the air, resulting in deacetic acid and deoxidized ξ
type.

This is a curing reaction by dealcoholization type, deoxime type, etc.

More specifically, after coating and curing, the organosiloxane that crosslinks and cures at room temperature or by heating to become an ink-repellent silicone rubber elastic body, and forms the organosiloxane cured film layer (3), is 90% or more of the groups have methyl groups, both ends of the molecular chain are hydroxyl groups, and contain methylhydrodiene polysiloxane or ethyl polysilicate as a crosslinking agent and an organic metal salt as a condensation catalyst.

■ More than 90% of all organic groups bonded to silicon atoms have methyl groups and also contain vinyl groups, and as a crosslinking agent,
Contains methylhydrodiene polysiloxane and a platinum-based catalyst as an addition reaction catalyst.

is particularly suitable. In addition, the organic group other than the methyl group bonded to the above-mentioned silicon atom is a phenyl group, an alkyl group other than the methyl group, a halogen-substituted alkyl group, an aryl group, etc. at -a.

In addition, it is possible to improve the repulsion of the ink by adding ordinary diorganopolysiloxane, such as dimethylorganosiloxane, to the extent that it does not have a negative effect on the cured film, and to add a small amount of silica etc. It is also possible to add inorganic powder to increase rigidity resistance. Additionally, organometallic peroxides.

A silicon compound having a vinyl group such as vinyl methyl silicone rubber, a crosslinking agent such as a reactive silane or siloxane such as SiH, 5jOH, 5iOC□H1, or an acid,
Catalysts such as alkalis, amines, and organic acid salts are also added as necessary.

Effect> The printing plate for lithographic printing according to the present invention has an ink-philic resin layer that forms the image area and an organosiloxane cured film layer that forms the non-image area, each of which is adhered to the substrate, so that it does not require the conventional method. There is no need for the substrate to have the ink receptivity required for the substrate of a lithographic printing plate, and in addition, the ink-philic resin layer required for a lithographic printing plate that does not use conventional dampening water can be used. Since adhesiveness with the organosiloxane cured film layer is not required, materials, shapes, etc. can be selected freely. Therefore, it is possible to select a cured organosiloxane film layer with high ink repellency, an ink-philic resin layer with high ink receptivity, and a substrate that has high adhesiveness with the cured organosiloxane film layer and the ink-philic resin layer, and has good printability and A printing plate for lithographic printing with extremely high printing durability can be obtained.

<Example> This will be explained in detail below using examples.

Example 1゜Thickness: 150 mm made porous by anodizing the surface
A cyclized rubber-based photosensitive resin (TOKYO OHKA, OMR) was coated onto a substrate made of a hard aluminum plate having a thickness of 8 μm and dried. A positive original was brought into close contact with the photosensitive resin, exposed, and then developed to form an image area made of an ink-philic resin layer.

95 parts of dimethylsilanediol and 5 parts of dimethyldichlorosilane were polycondensed using a methanol-water system and a hydrochloric acid catalyst to obtain an organosiloxane with an average degree of polymerization of 760 (in terms of styrene). After dissolving 10 parts of this organosiloxane in n-hexane, zirconium phosphate and benzoyl peroxide were added, and after coating using a bar coater on the substrate on which the image area made of the above-mentioned ink-friendly resin layer was formed, heating was performed. A non-image area consisting of an organosiloxane cured film layer was then formed, and a printing plate for lithographic printing was manufactured.

This printing plate for lithographic printing had a rigidity resistance of 50,000 sheets.

Example 2 35 parts of vinyl chloride-vinyl acetate copolymer containing 8 parts of fine silica powder (average particle size 0.03 μm), 65 parts of urethane resin, and diisocyanate as a crosslinking agent were added to a corona-treated 30 μm P-thickness T film. The coating solution containing the coating solution was applied and dried to obtain a substrate.

15μ of thermosetting styrene-acrylic acid ester resin
A transfer ribbon made of a 3 μm PET film coated with a thickness of m was transferred onto the substrate using a thermal head to form an image portion made of an ink-philic resin layer.

95 parts of dimethylsilanediol, 5 parts of dimethyldichlorosilane, and 5 parts of diphenylsilane were polycondensed using a methanol-water system and a hydrochloric acid catalyst to obtain an organosiloxane with an average degree of polymerization of 540 (in terms of styrene). After dissolving 10 parts of this organosiloxane in a mixed solvent of n-hexane-toluene, zinc octylate was added, and after coating by screen printing on the substrate on which the image area made of the above-mentioned ink-friendly resin layer was formed, the mixture was heated. A non-image area consisting of an organosiloxane cured film layer was formed to produce a printing plate for lithographic printing. Here, the organosiloxane cured product remaining on the image area had no adhesive property with the ink-philic resin layer and could be easily separated by 211 degrees.

This lithographic printing plate had a printing durability of 50,000 sheets.

Example 3 A 150 tI conductive base material (conductive carbon paper) was prepared with 12 parts of zinc oxide, 5 parts of copper phthalocyanine, and 30 parts of acrylic acid ester, methyl ethyl ketone, toluene, and isobrobyl alcohol. A coating liquid dispersed in a solvent was applied and dried to obtain a substrate which is an organic photoreceptor for electrophotography.

A liquid toner containing a thermosetting styrene-acrylate resin as a main component was transferred and fixed onto the substrate by electrophotography to form an image area made of an ink-philic resin layer.

40 parts of dimethylsilanediol, 50 parts of dimethylsilane, 5 parts of dimethyldichlorosilane, 10 parts of diphenylsilane
Part was polycondensed using a methanol-water system and a hydrochloric acid catalyst to obtain an organosiloxane having an average degree of polymerization toso <styrene equivalent. After dissolving 8 parts of this organosiloxane, 0, -5 parts of butyl ester siloxane, and 1 part of dimethylsiloxane in a toluene solvent, dibutyltin laurylate was added to the substrate on which the image area made of the above-mentioned ink-friendly resin layer was formed. After coating by screen printing, it was heated to form a non-image area consisting of an organosiloxane cured film layer to produce a printing plate for lithographic printing. Here, the organosiloxane cured product remaining on the image area had no adhesive property with the ink-philic resin layer and could be easily peeled off.

This printing plate for lithographic printing had a rigidity resistance of 50,000 sheets.

Example 4: Thickness: 150 mm made porous by anodizing the surface
T! 10 parts of polydimethylsiloxane having a vinyl group at the end of the molecular chain,
A mixed solution of 90 parts of polydimethylsiloxane and a bisazide compound was applied and dried using a spin coater, and a positive original was brought into close contact and exposed, and then developed to form a non-image area consisting of an organosiloxane cured film layer. A methyl ethyl ketone solution of thermosetting acrylic acid ester-based ink-friendly resin is coated on the substrate on which the non-image area made of the above-mentioned organosiloxane cured film layer is formed using a bar coater, and then heated and dried to form the ink-friendly resin layer. A printing plate for lithographic printing was manufactured by forming an image area consisting of the following.

This printing plate for lithographic printing had a rigidity resistance of 50,000 sheets.

<Effects of the Invention> The present invention is as described above, and the obtained lithographic printing plate has good ink receptivity in the image area, good ink repulsion in the non-image area, and has good printing durability. It is highly effective as a printing plate for lithographic printing.

Further, according to the manufacturing method of the present invention, since the ink-philic resin layer and the organosiloxane cured film layer are mutually repellent, if one layer is selectively formed, the other layer can be used to form a barcode. By carrying out such an entire surface coating operation, a film can be selectively formed on areas where one layer is not formed.

In addition, the ink-philic resin layer and the like can be formed not only by a photosensitive material but also by transfer.

Furthermore, there is no need to remove the silicone rubber layer by friction with a cloth, which is necessary in the conventional waterless planographic development process.

[Brief explanation of drawings]

FIG. 1 and FIG. 2 are cross-sectional views schematically showing an embodiment of a printing plate for lithographic printing of the present invention. l...Substrate 3...Organosiloxane cured film layer/ink-philic resin layer Patent Applicant: Toppan Printing Co., Ltd. Representative: Kazuo Suzuki

Claims (5)

[Claims] (1) The substrate has an image area made of an ink-friendly resin layer and a non-image area made of an organosiloxane cured film layer, and the ink-friendly resin layer and the organosiloxane cured film layer are each adhered to the substrate. A printing plate for lithographic printing. (2) After providing an image area made of an ink-philic resin layer on the substrate, a repellent organosiloxane solution is applied to the image area and then cured to form a non-image area. A method for manufacturing a printing plate for lithographic printing. (3) The method for producing a printing plate for lithographic printing according to claim (2), wherein the image area made of the ink-philic resin layer is formed using a photosensitive resin. (4) The method for producing a printing plate for lithographic printing according to claim (2), wherein the image portion made of the ink-philic resin layer is formed by transfer. (5) After providing a non-image area made of an organosiloxane cured film layer on the substrate, a solution containing an ink-repellent ink-philic resin is applied to the non-image area, and then dried to form an ink-philic resin layer. 1. A method for producing a printing plate for lithographic printing, the method comprising forming an image area consisting of: