DE112010004234B4 - Thermosensitive lithographic printing plate and its printing process - Google Patents

Abstract

A thermosensitive lithographic printing plate having on a waterproof support at least 2 layers of imaging layers containing a water-soluble polymer compound (s), a curing agent and thermoplastic resin (s), and with respect to those of the water-resistant one Carrier farthest imaging layer (B) and an imaging layer (A) closer to the waterproof carrier than the imaging layer (B) satisfies the following requirement i) and / or ii). i) The ratio of the thermoplastic resin (s) with respect to the water-soluble polymer compound (s) in the image-forming layer (A) is higher than the ratio of the thermoplastic resin (s) with respect to the water-soluble polymer compound (en) in the imaging layer (B). ii) The ratio of at least one compound to be selected from the compounds represented by the following general formulas (1) to (4) based on the water-soluble polymer compound (s) in the image-forming layer (A) is higher than the ratio of at least one of compound to be selected from the compounds represented by the following general formulas (1) to (4), based on the water-soluble polymer compound (s) in the image-forming layer (B). [Chemical formula 1] (wherein X 1 represents -O- or -COO-, R 1, R 2 and R 3 each independently represents a hydrogen atom, an alkyl group or an aryl group, or R 1, R 2 and R 3 join together to form an aromatic ring, R 4 R5 and R6 independently of one another each represent a hydrogen atom, an alkyl group or an aryl group, or R4, R5 and R6 connected to each other form an aromatic ring, and n represents an integer of 1 to 10. [Chemical Formula 2]

Description

[Field of technology]

The invention generally relates to a thermosensitive lithographic printing plate having thermally phase change imaging layers, more particularly to a thermosensitive lithographic printing plate that does not require any conventional process for layer removal such as ablation or development in the printing press and its printing method.

Background of the Invention

In recent years, due to the advancement of computers and their peripherals, various methods for printing plate production by means of various digital printers have been proposed. For example, out JP H 6-138719 A and JP H 6-250424 A printing plate production with a xerographic laser printer JP H 9-58144 A printing plate production with an on-demand inkjet printer using hot melt inks and finally off JP S 63-166590 A printing plate production with a thermal printer using thermal transfer ribbons.

The above-mentioned methods for printing plate production are substantially different from the conventional light mode methods using lasers in the visible light range and have the advantage that handling is not subject to a clarity light requirement. And, because of the fact that they no longer require a conventional development process in the conventional light-mode process, the printing plates produced by these printing plate production methods are collectively referred to as processless printing plates.

• 1) Wegen der hydrophilen Bebilderungsschicht ist das Anhaften von Toner oder Tinten nicht ausreichend, so dass es nachteiligerweise zu mangelnder Dichte des übertragenen Tonerbildes oder zur Bildung von Fehlstellen im übertragenen Bild kommt.
• 2) Das übertragene Bild ist nicht hinreichend fixiert; die Drucklebensdauer nimmt nachteiligerweise ab, insbesondere in Teilen von Schriftzeichen in kleinpunktigen Größen oder in niedrig aufgelöst gerasterten Bildern treten Mängel auf.
• 3) Durch unregelmäßige Übertragung kleiner Mengen vom Toner auf die Nichtbildstellen oder durch das Scheuern des Thermotransferfarbbandes tritt nachteiligerweise über die gesamte Fläche leichtes Tonen auf.

However, the above-mentioned processless printing plates, which are all formed by transferring fat-sensitive (ie, accepting lithographic inks) recording images to the surface of the support having a water holding-imparting layer, have the following disadvantages.

• 1) Because of the hydrophilic imaging layer, the adhesion of toner or inks is not sufficient, so that it disadvantageously comes to lack of density of the transferred toner image or formation of defects in the transferred image.
• 2) The transferred image is not sufficiently fixed; the printing life decreases disadvantageously, especially in parts of characters in small sizes or in low-resolution screened images occur deficiencies.
• 3) By irregularly transferring small amounts of the toner to the non-image areas or by rubbing the thermal transfer ribbon, it is disadvantageous that slight cloning occurs over the entire area.

On the other hand, there are also proposed processless printing plates in which a imaging layer containing thermoplastic resin or heat-melting substance is formed on the support and thermally printed with a thermal head or infrared laser, thereby obtaining lipophilic image sites.

So is in JP S 58-199153 A (Patent Document 1) or JP S 59-174395 A (Patent Document 2), a thermosensitive lithographic printing plate is described in which lipophilic image areas are obtained by directly thermally imaging the imaging layer without the use of a thermal transfer ribbon or the like, for example with a thermal head. In JP 2000-190649 A (Patent Document 3) and JP 2000-301846 A (Patent Document 4) thermosensitive lithographic printing plates are described in which lipophilic image sites by the thermal imaging z. B. be obtained with infrared laser. In conventional lithographic printing, water and ink are simultaneously fed to the lipophilic image sites obtained as described above, the image sites accepting the coloring ink, while the other non-image sites, since hydrophilic, selectively accept water, and by the transfer of the assumed in the image ink to the substrate such as B. paper is the print.

However, in these thermosensitive lithographic printing plates, the difference in lipophilic-hydrophilic between the image sites and the non-image sites was usually not large enough, so they had the disadvantages that sharp printed images were difficult to obtain, the press life was sometimes insufficient, and the toning occurred frequently.

A thermosensitive lithographic printing plate in which sharp high image density can be obtained is in the form of the method in which the imaging layer is inorganic pigments, thermoplastic Contains resin and heat-melting substance, in JP S 63-64747 A (Patent Document 5). Incidentally, in the thermosensitive lithographic printing plate according to Patent Document 3 or Patent Document 4 for improving the balance between the lipophilicity of the image sites and the hydrophilicity of the non-image sites, there is also a process in which a lipophilic-developing heat-melting substance having a substance having a specific heat conductivity and a technique for utilizing the chelate reaction by heat to hydrophobize the hydrophilic group of hydrophilic polymer is disclosed. However, in both cases, the reaction is difficult to control, and the difference in lipophilic-hydrophilic between image sites and non-image sites is not large enough, so that the drawbacks of lack of press life and frequent toning still remain unobtrusive.

With regard to the disadvantages such as the press life and toning is in JP H 11-95417 A (Patent Document 6) discloses that the press life and the water holding ability are improved by using hydrophilic resin such as polyvinyl alcohol or carboxylmethyl cellulose crosslinked for the imaging layer using the phase change of the hydrophilic resin itself, so that the degree of image lipophilization is low and the difference lipophilic-hydrophilic was not big enough. Loud JP 2000-75471 A (Patent Document 7), by the use of thermoplastic resin, wax dispersion or water repellent as the hydrophobicity-developing substance and gelatin or polyvinyl alcohol as the hydrophilic substance, especially the water resistance and the print reproduction have been improved, again, the difference is not lipophilic-hydrophilic was big enough.

In JP 2000-238451 A (Patent Document 8), there is provided a technique of increasing the press life by providing on the support an image-forming layer containing a photothermal substance, thermoplastic resin and resin particle-insulating agent, the content of the photothermal substance having a gradient in the direction of the layer thickness , which was not completely satisfactory. Accordingly, a thermosensitive lithographic printing plate having thermally phase change imaging layers has been required which has good printing life and tonelessness and does not require a conventional process for layer removal such as ablation or development in the printing press.

Furthermore, in JP 2006-272941 A (Patent Document 9) A lithographic printing plate having a technique of forming an imaging layer containing a heat-transferable hydrophobicity reactant and a color developing dye upon heating and a hydrophilic layer as the outermost layer to enhance the press life by providing on the support an image-forming layer containing a photothermal substance, thermoplastic resin and resin particle-insulating agent, the content of the photothermal substance having a gradient in the direction of the layer thickness, and JP 2009-255498 A (Patent Document 10) discloses a thermosensitive lithographic printing plate to which certain compounds such as diphenylalkane, benzylnaphthalene, dibenzyl oxalate or diphenoxymethylbenzene are added, respectively, in which case the difference hydrophobic-hydrophilic was not large enough, so that the disadvantages of lack of press life and of the frequently occurring toning remained unobtrusive.

Further, the direct-thermosensitive lithographic printing plates according to said patent documents 1, 2, 9 and 10 are e.g. Example, thermally imaged directly with a thermal head, which is why they had the disadvantages in addition to the tasks described above, that stuck in the thermal imaging by the heat image parts stuck to the thermal head and the image disturbed, so the so-called sticking caused or by the heat and the printing of the thermal head in the course of successive plate production, the heat-melting substance in the imaging layer adheres to the heat-developing portion of the thermal head and prevents heat conduction from the thermal head, thus no longer permitting proper imaging and resulting in printing defects, that is, printing defects because of so mentioned head deposition often causes. Consequently, a thermosensitive lithographic printing plate having thermally phase change imaging layers which has good printing life and tonelessness (water holding capacity), improvements in printing defects due to the head deposit and image disturbance by the sticking phenomenon has been demanded, and no conventional process for layer removal such as ablation or Development in the printing press required. In addition revealed EP 1 902 853 A1 a lithographic printing plate precursor containing a base material (I), a photosensitive layer (II) and a layer (III), the photosensitive layer (II) containing a light-heat converting agent, a water-soluble polymer and a hydrophobic polymer, and the layer (III) covers the photosensitive layer (II).

In addition, the reveals WO 2009/078346 A1 a heat-sensitive lithographic printing plate comprising a water-resistant substrate and an imaging layer formed on the substrate, which contains a thermoplastic resin, a water-soluble polymer compound and at least one of the presently disclosed compounds of the formulas (1) to (4), and a direct-type heat-sensitive lithographic printing plate.
[Patent Document 1] JP S 58-199153 A
[Patent Document 2] JP S 59-174395 A
[Patent Document 3] JP 2000-190649 A
[Patent Document 4] JP 2000-301846 A
[Patent Document 5] JP S 63-64747 A
[Patent Document 6] JP H 11-95417 A
[Patent Document 7] JP 2000-75471 A
[Patent Document 8] JP 2000-28451 A
[Patent Document 9] JP 2006 -272941 A
[Patent Document 10] JP 2009 -255498 A

[Disclosure of Invention]

[Problem underlying the invention]

Thus, the object of the invention is, firstly, to provide a thermosensitive lithographic printing plate having thermally phase change imaging layers which has good printing life and tonelessness (water holding capacity) and does not require a conventional process for layer removal such as ablation or development in the printing press. Secondly, it is to provide a thermosensitive lithographic printing plate which has good printing life and tonelessness (water holding capacity) and brings about improvements in print defects due to the head deposit and image disturbance by the sticking phenomenon.

[Means to solve the problem]

• (1) Thermosensitive lithographische Druckplatte, die auf einem wasserfesten Träger mindestens 2 Schichten von Bebilderungsschichten aufweist, welche (eine) wasserlösliche Polymerverbindung(en), ein Härtungsmittel und (ein) thermoplastische(s) Harz(e) enthalten, und in Bezug auf die von dem wasserfesten Träger am weitesten entfernte Bebilderungsschicht (B) und eine näher am wasserfesten Träger als die Bebilderungsschicht (B) befindliche Bebilderungsschicht (A) die folgende Voraussetzung i) und/oder ii) erfüllt. i) Das Verhältnis des/der thermoplastischen Harze(s) bezogen auf die wasserlösliche(n) Polymerverbindung(en) in der Bebilderungsschicht (A) ist höher als das Verhältnis des/der thermoplastischen Harze(s) bezogen auf die wasserlösliche(n) Polymerverbindung(en) in der Bebilderungsschicht (B). ii) Das Verhältnis mindestens einer aus den durch die folgenden allgemeinen Formeln (1) bis (4) dargestellten Verbindungen auszuwählenden Verbindung bezogen auf die wasserlösliche(n) Polymerverbindung(en) in der Bebilderungsschicht (A) ist höher als das Verhältnis mindestens einer aus den durch die folgenden allgemeinen Formeln (1) bis (4) dargestellten Verbindungen auszuwählenden Verbindung bezogen auf die wasserlöslichen) Polymerverbindung(en) in der Bebilderungsschicht (B).

The object described above has been solved by the following means.

• (1) A thermosensitive lithographic printing plate having on a waterproof base at least 2 layers of imaging layers containing a water-soluble polymer compound (s), a curing agent and a thermoplastic resin (s), and with respect to of the waterproof carrier farthest imaging layer (B) and an imaging layer (A) closer to the waterproof carrier than the imaging layer (B) satisfies the following requirement i) and / or ii). i) The ratio of the thermoplastic resin (s) with respect to the water-soluble polymer compound (s) in the image-forming layer (A) is higher than the ratio of the thermoplastic resin (s) with respect to the water-soluble polymer compound (en) in the imaging layer (B). ii) The ratio of at least one compound to be selected from the compounds represented by the following general formulas (1) to (4) based on the water-soluble polymer compound (s) in the image-forming layer (A) is higher than the ratio of at least one of compound to be selected from the following general formulas (1) to (4) represented by compounds based on the water-soluble polymer compound (s) in the image-forming layer (B).

wobei X₁ -O- oder -C O-O- darstellt,
R₁, R₂ und R₃ unabhängig voneinander jeweils ein Wasserstoffatom, eine Alkylgruppe oder Arylgruppe darstellen- oder- R₁, R₂ und R₃ miteinander verbunden einen aromatischen Ring bilden,
R₄, R₅ und R₆ unabhängig voneinander jeweils ein Wasserstoffatom, eine Alkylgruppe oder Arylgruppe darstellen- oder- R₄, R₅ und R₆ miteinander verbunden einen aromatischen Ring bilden, und
n eine ganze Zahl von 1 bis 10 darstellt. [Chemische Formel 2]

wobei R₇ eine Alkylgruppe, Arylgruppe, Alkylcarbonylgruppe, Arylcarbonylgruppe, Alkylsulfonylgruppe oder Arylsulfonylgruppe darstellt und der Naphthalenring gemäß der allgemeinen Formel (2) weitere Substituenten aufweisen kann. [Chemische Formel 3]

wobei R₈ und R₉ unabhängig voneinander jeweils ein Wasserstoffatom, Halogenatom, eine Alkylgruppe mit einer Kohlenstoffzahl von 1 bis 4 oder Alkoxygruppe mit einer Kohlenstoffzahl von 1 bis 4 darstellen, X₂ eine Einfachbindung oder -O- darstellt und n eine ganze Zahl von 1 bis 4 darstellt. [Chemische Formel 4]

wobei R₁₀, R_10', R₁₁ und R_11' unabhängig voneinander jeweils ein Wasserstoffatom, Halogenatom, eine Alkylgruppe, Arylgruppe, Alkoxygruppe, Alkylcarbonylgruppe, Arylcarbonylgruppe, Alkoxycarbonylgruppe oder Aryloxygruppe darstellen.

• (2) Thermosensitive lithographische Druckplatte nach dem vorstehenden Punkt (1), bei welcher der Unterschied zwischen dem Verhältnis des/der thermoplastischen Harze(s) bezogen auf die wasserlösliche(n) Polymerverbindung(en) in der oben genannten Bebilderungsschicht (A) und dem Verhältnis des/der thermoplastischen Harze(s) bezogen auf die wasserlösliche(n) Polymerverbindung(en) in der oben genannten Bebilderungsschicht (B) 0,5 oder mehr beträgt.
• (3) Thermosensitive lithographische Druckplatte nach dem vorstehenden Punkt (1) oder (2), bei welcher das Verhältnis des/der thermoplastischen Harze(s) bezogen auf die wasserlösliche(n) Polymerverbindung(en) in der oben genannten Bebilderungsschicht (A) 1 bis 20 beträgt und das Verhältnis des/der thermoplastischen Harze(s) bezogen auf die wasserlösliche(n) Polymerverbindung(en) in der oben genannten Bebilderungsschicht (B) 0,1 bis 3 beträgt.
• (4) Thermosensitive lithographische Druckplatte nach dem vorstehenden Punkt (1), bei welcher das Verhältnis mindestens einer aus den durch die allgemeinen Formeln (1) bis (4) dargestellten Verbindungen auszuwählenden Verbindung bezogen auf die wasserlösliche(n) Polymerverbindung(en) in der oben genannten Bebilderungsschicht (B) 0,5 oder weniger beträgt.
• (5) Thermosensitive lithographische Druckplatte nach dem vorstehenden Punkt (1) oder (4), bei welcher der Unterschied zwischen dem Verhältnis mindestens einer aus den durch die allgemeinen Formeln (1) bis (4) dargestellten Verbindungen auszuwählenden Verbindung bezogen auf die wasserlösliche(n) Polymerverbindung(en) in der oben genannten Bebilderungsschicht (A) und dem Verhältnis mindestens einer aus den durch die allgemeinen Formeln (1) bis (4) dargestellten Verbindungen auszuwählenden Verbindung bezogen auf die wasserlösliche(n) Polymerverbindung(en) in der oben genannten Bebilderungsschicht (B) 1,0 oder mehr beträgt.
• (6) Thermosensitive lithographische Druckplatte nach einem der vorstehenden Punkte (1) bis (5), welche die oben genannten Voraussetzungen i) und ii) erfüllt.
• (7) Thermosensitive lithographische Druckplatte nach einem der vorstehenden Punkte (1) bis (6), welche zwischen der oben genannten Bebilderungsschicht (A) und dem wasserfesten Träger eine Grundierungsschicht aufweist, die Titandioxid, dessen mittlerer Teilchendurchmesser kleiner als die mittlere Trockenfilmdicke der Grundierungsschicht ist, Bindemittelharz und Vernetzungsmittel mindestens enthält.
• (8) Thermosensitive lithographische Druckplatte nach einem der vorstehenden Punkte (1) bis (7), bei welcher die oben genannte Bebilderungsschicht (B) Zinkoxid oder Bariumsulfat enthält.
• (9) Thermosensitive lithographische Druckplatte nach einem der vorstehenden Punkte (1) bis (8), bei welcher die Bebilderungsschichten bezogen auf die Feststoffmenge der in den gesamten Bebilderungsschichten enthaltenen wasserlöslichen Polymerverbindung(en) 5 bis 30 Gew.-% Härtungsmittel enthalten.
• (10) Druckverfahren der thermosensitiven lithographischen Druckplatte, bei welchem die thermosensitive lithographische Druckplatte nach einem der vorstehenden Punkte (1) bis (9) bedruckt wird und anschließend, ohne die Bebilderungsschichten abzutragen, der Druck erfolgt.

[Chemical Formula 1]

where X _{1 represents} -O- or -COO-,
R ₁ , R ₂ and R _3, independently of one another, each represent a hydrogen atom, an alkyl group or an aryl group, or R ₁ , R ₂ and R ₃ together form an aromatic ring,
R ₄ , R ₅ and R ₆ independently of one another each represent a hydrogen atom, an alkyl group or an aryl group; or R ₄ , R ₅ and R ₆ connected to one another form an aromatic ring, and
n represents an integer from 1 to 10. [Chemical formula 2]

wherein R _{7 represents} an alkyl group, aryl group, alkylcarbonyl group, arylcarbonyl group, alkylsulfonyl group or arylsulfonyl group and the naphthalene ring according to the general formula (2) may have further substituents. [Chemical Formula 3]

wherein R ₈ and R ₉ each independently represents a hydrogen atom, halogen atom, an alkyl group having a carbon number of 1 to 4 or alkoxy group having a carbon number of 1 to 4, X _{2 represents} a single bond or -O-, and n represents an integer of 1 to 4 represents. [Chemical formula 4]

wherein R ₁₀ , R _{10 '} , R ₁₁ and R _11' each independently represent a hydrogen atom, halogen atom, an alkyl group, aryl group, alkoxy group, alkylcarbonyl group, arylcarbonyl group, alkoxycarbonyl group or aryloxy group.

• (2) The thermosensitive lithographic printing plate as defined in (1) above, wherein the difference between the ratio of the thermoplastic resin (s) relative to the water-soluble polymer compound (s) in the above-mentioned imaging layer (A) and the above-mentioned Ratio of the thermoplastic resin (s) based on the water-soluble polymer compound (s) in the above-mentioned imaging layer (B) is 0.5 or more.
• (3) The thermosensitive lithographic printing plate according to (1) or (2) above, wherein the ratio of the thermoplastic resin (s) with respect to the water-soluble polymer compound (s) in the above-mentioned imaging layer (A) 1 to 20, and the ratio of the thermoplastic resin (s) based on the water-soluble polymer compound (s) in the above-mentioned imaging layer (B) is 0.1 to 3.
• (4) The thermosensitive lithographic printing plate according to the above item (1), wherein the ratio of at least one compound to be selected from the compounds represented by the general formulas (1) to (4) based on the water-soluble polymer compound (s) in the The above-mentioned imaging layer (B) is 0.5 or less.
• (5) The thermosensitive lithographic printing plate according to (1) or (4) above, wherein the difference between the ratio of at least one compound to be selected from the compounds represented by the general formulas (1) to (4) relative to the water-soluble (n Polymer compound (s) in the above-mentioned imaging layer (A) and the ratio of at least one compound to be selected from the compounds represented by the general formulas (1) to (4) based on the water-soluble polymer compound (s) in the above Imaging layer (B) is 1.0 or more.
• (6) The thermosensitive lithographic printing plate according to any one of (1) to (5) above, which satisfies the above-mentioned conditions i) and ii).
• (7) A thermosensitive lithographic printing plate according to any one of the above items (1) to (6), comprising, between the above-mentioned imaging layer (A) and the waterproof support, a primer layer comprising titanium dioxide whose average particle diameter is smaller than the average dry film thickness of the undercoat layer , Binder resin and crosslinking agent at least.
• (8) The thermosensitive lithographic printing plate according to any one of the above items (1) to (7), wherein the above-mentioned imaging layer (B) contains zinc oxide or barium sulfate.
• (9) The thermosensitive lithographic printing plate according to any one of the above items (1) to (8), wherein the imaging layers contain from 5 to 30% by weight of a hardener based on the amount of solids of the water-soluble polymer compound (s) contained in the entire imaging layers.
• (10) The printing method of the thermosensitive lithographic printing plate, wherein the thermosensitive lithographic printing plate according to any one of (1) to (9) above is printed and then, without removing the Bebilderungsschichten, the printing takes place.

Effect of the Invention

Firstly, the invention can provide a thermosensitive lithographic printing plate having thermally phase change imaging layers which has good printing life and tonelessness (water holding capacity) and which does not require a conventional process for layer removal such as ablation or development in the printing press. Secondly, there can be provided a thermosensitive lithographic printing plate which, in addition to high press life and tonelessness (water holding capacity), brings about improvements in print defects due to the head deposit and image disturbance by the sticking phenomenon.

[Optimal Embodiment of the Invention]

In the following the invention will be explained in detail.

As used in the present specification, the term "alkyl" is to be understood as meaning a saturated straight-chain or branched-chain hydrocarbon group, including, inter alia, methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, 2-butyl, t-butyl , Pentyl, hexyl and decanyl.
The term "alkoxy" is to be understood as meaning a group from the abovementioned saturated straight-chain or branched-chain hydrocarbon groups which are bonded to one another via an oxygen atom.
The term "halogen" is to be understood as meaning chlorine, iodine, fluorine and bromine.
By the term "aryl" is meant a monovalent cyclic aromatic hydrocarbon group of one or two condensed ring (s), at least one of which has the aromatic characteristic, among which are, for example, phenyl, benzyl, naphthyl or biphenyl.

The imaging layers of the thermosensitive lithographic printing plate satisfying condition i) will now be explained. A thermosensitive lithographic printing plate according to i) comprises on a waterproof support at least 2 layers of imaging layers containing a water-soluble polymer compound (s), a curing agent and a thermoplastic resin (s), wherein the ratio of the thermoplastic resin (s) Resin (s) based on the water-soluble polymer compound (s) (ie, the mass of the thermoplastic resin (s) / mass of the water-soluble polymer compound (s)) in the carrier closer to the waterproof carrier than the imaging layer (B) Imaging layer (A) (hereinafter simply referred to as imaging layer (A)) is higher than the ratio of the thermoplastic resin (s) with respect to the water-soluble polymer compound (s) in the imaging layer (B) furthest from the waterproof support. (hereinafter referred to simply as the imaging layer (B)). By forming at least 2 layers of imaging layers in this design, it becomes possible to provide a thermosensitive lithographic printing plate having thermally phase change imaging layers which has good printing life and tonelessness (water retention) and does not require a conventional process for layer removal such as ablation or development in the printing press.

The reason why in the invention the thermosensitive lithographic printing plate satisfying the design of i) achieves good printing life and tonelessness (water holding capacity) has not been clarified, but the following is presumed.

The thermosensitive lithographic printing plate according to i) has imaging layers which use the thermal phase change to change to hydrophobicity. The layer referred to here, which changes to hydrophobicity, is a layer whose parts are exposed to heat melt and change to hydrophobicity, while the parts retain the hydrophilicity of the original layer without the action of heat. Specifically, when changing the heat-melting parts of the imaging layer to hydrophobicity, the thermoplastic resin buried in the water-soluble polymer compound exits to the surface of the layer, thus developing the hydrophobicity. In the non-printed areas, ie the non-image areas, however, the thermoplastic resin remains buried in the water-soluble polymer compound, which is why no hydrophobicity develops. In order to improve the press life and tonelessness (water holding capacity) of the thermosensitive lithographic printing plate, the difference of which is hydrophobic-hydrophilic between the image sites and non-image sites in this manner, it is important to sufficiently maintain this difference even during printing. In the present invention, presumably, a lower ratio of the thermoplastic resin (s) relative to the water-soluble polymer compound (s) in the imaging layer (B) furthest from the waterproof support increases the hydrophilicity of the surface, thus increasing the water holding capacity pressure is further increased, while at the same time the hydrophobicity thereby reduced is overcome by the formation of an imaging layer (A) having a higher ratio of the thermoplastic resin (s) than the imaging layer (B) and closer to the waterproof support , whereby the sufficient release of the thermoplastic resin (s) to the surface in the imaging becomes possible, resulting in that high press life and tonelessness (water holding capacity) can be united.

In the thermosensitive lithographic printing plate according to i), there is no limitation on the method for producing thermosensitive lithographic printing plates characterized in that the ratio of the thermoplastic resin (s) relative to the water-soluble polymer compound (s) in the imaging layer (A) is higher than the corresponding ratio in the imaging layer (B), wherein, for example, a method is conceivable in which first the imaging layer (A) is applied and then the imaging layer (B) of the realms is applied or also a method the slide-hopper process several layers are applied at once.

The ratio of the thermoplastic resin (s) with respect to the water-soluble polymer compound (s) in the image-forming layer (A) can be arbitrarily set so long as it is higher than the corresponding ratio in the image-forming layer (B) between the corresponding ratio in the imaging layer (A) and the corresponding ratio in the imaging layer (B) should preferably be 0.5 or more.

When three layers of imaging layers are formed in the thermosensitive lithographic printing plate of i), an imaging layer (C) may be formed between the imaging layer (A) and the imaging layer (B). The ratio of the thermoplastic resin (s) with respect to the water-soluble polymer compound (s) in the image-forming layer (C) may be higher or lower than the corresponding ratio in the image-forming layer (B), but should preferably be lower than the corresponding one Ratio in the imaging layer (A) and higher than the corresponding ratio in the imaging layer (B).

In the thermosensitive lithographic printing plate of i), a ratio of the thermoplastic resin (s) with respect to the water-soluble polymer compound (s) (the mass of the thermoplastic resin (s) / mass of the water-soluble polymer compound (s) ) in the imaging layer (B) of 0.01 to 10; more preferably 0.1 to 3. Incidentally, a corresponding ratio in the image-forming layer (A) of 0.1 to 50 is advantageous; even more advantageously 1 to 20.

The imaging layers of the thermosensitive lithographic printing plate according to i) contain thermoplastic resin (s). By the thermoplastic resin is meant an organic polymer compound in the solid state, which consists of straight-chain polymers and obtains plasticity by heating. The thermoplastic resin of the present invention is added to the coating composition used for forming imaging layers in the form of an aqueous dispersion of the thermoplastic resin, and is present in the imaging layers after coating and drying the coating composition in the form of thermoplastic resin particles. The most important examples of the thermoplastic resin include synthetic rubber latices such as styrene-butadiene copolymer, acrylonitrile-butadiene copolymer, methyl methacrylate-butadiene copolymer, styrene-acrylonitrile-butadiene copolymer and styrene-methyl methacrylate-butadiene copolymer, and their modifications. Modifications of synthetic rubber latices include amino-modification, polyether-modification, epoxy-modification, fatty acid-modification, carbonyl-modification and carboxy-modification. Other examples of the thermoplastic resin include styrene-maleic anhydride copolymer, methyl vinyl ether-maleic anhydride copolymer, polyacrylic acid copolymer, Polystyrene, styrene / acrylic acid ester copolymer, polyacrylic acid ester, polymethacrylic acid ester, acrylic acid ester / acrylic acid ester copolymer and low melting polyamide resins may also be mentioned. These thermoplastic resins may be used singly or in combination of two or more kinds. Because of the compatibility with the vehicle (binder) of printing inks, the synthetic rubber latices are preferable as the thermoplastic resin, in particular, styrene-butadiene copolymer and its modifications are preferable. The addition amount of the thermoplastic resin (s) in the entire imaging layers should preferably be 5 to 50% by weight based on the solid amount of the entire imaging layers.

Further, in order for the thermal melting and fusion bonding effect to be easily exhibited, a glass transition temperature of the thermoplastic resin of 50 to 150 ° C is advantageous; even more advantageous 55 to 120 ° C. At a glass transition temperature lower than 50 ° C, phase change to liquid state occurs during the manufacturing process, with lipophilicity also developing in the non-image areas, which can cause toning of the prints. At a glass transition temperature higher than 150 ° C, the thermal melting of the polymer is difficult to occur, so that it may be difficult to achieve robust imaging by means of a laser with a relatively small power or a small thermal printer.

The imaging layers of the thermosensitive lithographic printing plate according to i) contain (a) water-soluble polymer compound (s). Examples of suitable water-soluble polymer compounds include polyvinyl alcohol and its modifications (eg, carboxy-modified polyvinyl alcohol, acetoacetyl group-modified polyvinyl alcohol and silanol-modified polyvinyl alcohol), polysaccharides such as hydroxyethyl cellulose, methyl cellulose, carboxymethyl cellulose, pullulan, starch and its derivatives, gelatin, casein, sodium alginate, polyvinylpyrrolidone, styrene Maleic acid copolymer salt, styrene-acrylic acid copolymer salt. These water-soluble polymer compounds may be used singly or in combination of two or more kinds. In particular, because of their rich film formation, gelatin, polyvinyl alcohol and their modifications are favorable for the maintenance of the hydrophilicity of the non-image sites, therefore, they are selected. The addition amount of the water-soluble polymer compound (s) in the entire imaging layers should preferably be 0.5 to 50% by weight based on the total solid amount of the entire imaging layers.

Further, the imaging layers for increasing the water resistance and the mechanical strength of the non-image sites corresponding to the selected said water-soluble polymer compound contain curing agents (water resistance agents). As the curing agent, there can be used those which impart water resistance by promoting crosslinking of the resin; as such, for example, u. a. Melamine resin, epoxy resin, polyisocyanate compound, aldehyde compound, silane compound, chrome alum, and divinylsulfone. In particular, in gelatin as the water-soluble polymer compound, divinyl sulfone is preferably used as the curing agent, while in the case of polyvinyl alcohol as the water-soluble polymer compound, glyoxal is preferably used as the curing agent. The amount of addition of the curing agent in the entire imaging layers should preferably be 0.01 to 30% by weight based on the solid amount of the water-soluble polymer compound (s) contained in the entire imaging layers, with an addition amount of 5 to 30% by weight being more preferable ,

The imaging layers according to i) may contain a heat-melting substance (s), which is an advantageous form from the viewpoint of press life. As the contained heat-melting substance, an organic compound having a melting point of 50 to 150 ° C is advantageous. At a lower melting point of the heat-melting substance than 50 °, it melts during the manufacturing process, which can cause the toning of the prints. At a higher melting point of the melting substance in heat than 150 °, however, it melts z. B. by the heat transfer from the thermal head difficult so that may develop little lipophilicity. Examples of heat-melting substances which are preferably used are wax such as carnauba wax, microcrystalline wax, paraffin wax and polyethylene wax, fatty acid such as lauric acid, stearic acid, oleic acid, palmitic acid, behenic acid and montanic acid and their esters and amides. In addition, as the heat-melting substance, the compounds to be explained later in detail in the present specification, represented by the general formulas (1) to (4), may be used. Among the compounds represented by the general formulas (1) to (4), among others, preferred compounds are: 1- (1-naphthoxy) -2-phenoxyethane, 1- (2-naphthoxy) -4-phenoxybutane, 1- (2 -isopropylphenoxy) -2- (2-naphthoxy) ethane, 1- (4-methylphenoxy) -3- (2-naphthoxy) propane, 1- (2-methylphenoxy) -2- (2-naphthoxy) ethane, 1- ( 3-methylphenoxy) -2- (2-naphthoxy) ethane, 1- (2-naphthoxy) -2-phenoxyethane, 1- (2-naphthoxy) -6-phenoxyhexane, 1-phenoxy-2- (2-phenylphenoxy) ethane , 1- (2-methylphenoxy) -2- (4-phenylphenoxy) ethane, 1,4- diphenoxybutane, 1,4-bis (4-methylphenoxy) butane, 1,2-di (3,4-dimethylphenoxy) ethane, 1-phenoxy-3- (4-phenylphenoxy) propane, 1- (4-tert-butylphenoxy) 2-phenoxyethane, 1,2-diphenoxyethane, 1- (4-methylphenoxy) -2-phenoxyethane, 1- (2,3-dimethylphenoxy) -2-phenoxyethane, 1- (3,4-dimethylphenoxy) -2-phenoxyethane , 1- (4-ethylphenoxy) -2-phenoxyethane, 1- (4-isopropylphenoxy) -2-phenoxyethane, 1,2-bis (2-methylphenoxy) ethane, 1- (2-methylphenoxy) -2- (4- methylphenoxy) ethane, 1- (4-tert-butylphenoxy) -2- (2-methylphenoxy) ethane, 1,2-bis (3-methylphenoxy) ethane, 1- (3-methylphenoxy) -2- (4-methylphenoxy) ethane, 1- (4-ethylphenoxy) -2- (3-methylphenoxy) ethane, 1,2-bis (4-methylphenoxy) ethane, 1- (2,3-dimethylphenoxy) -2- (4-methylphenoxy) ethane, 1- (2,5-dimethylphenoxy) -2- (4-methylphenoxy) ethane, phenoxyacetic acid 2-naphthyl, 2-naphthoxyacetic acid 4-methylphenyl, 2-naphthoxyacetic acid 3-methylphenyl, 1-benzyloxynaphthalene, 2-benzyloxynaphthalene, 2 p-chlorobenzyloxynaphthalene, 2-p-isopropylbenzyloxynaphthalene, 2-dodecyloxynaphthalene, 2-decanoyl loxynaphthalene, 2-myristoyloxynaphthalene, 2-p-tert-butylbenzoyloxynaphthalene, 2-benzoyloxynaphthalene, 2-benzyloxy-3-N- (3-dodecyloxypropyl) carbamoylnaphthalene, 2-benzyloxy-3-N-octylcarbamoylnaphthalene, 2-benzyloxy-3-dodecyloxycarbonylnaphthalene , 2-benzyloxy-3-p-tert-butylphenoxycarbonylnaphthalene, oxalic acid bisbenzyl, oxalic acid bis (p-methylbenzyl), oxalic acid bis (p-chlorobenzyl), oxalic acid bis (m-methylbenzy1), oxalic acid bis (p- ethylbenzy1), bis (p-methoxybenzyl) oxalic acid, bis (2-phenoxyethyl) oxalic acid, bis (2-o-chlorophenoxyethyl) oxalic acid, bis (2-p-chlorophenoxyethyl) oxalic acid, oxalic acid bis (2-p -ethylphenoxyethyl), oxalic acid bis (2-m-methoxyphenoxyethyl), oxalic acid bis (2-p-methoxyphenoxyethyl), oxalic acid bis (4-phenoxybutyl), 1,2-bisphenoxymethylbenzene, 1,3-bisphenoxymethylbenzene, 1,4 bis (2-methylphenoxymethyl) benzene, 1,4-bis (3-methylphenoxymethyl) benzene, 1,3-bis (4-methylphenoxymethyl) benzene, 1,3-bis (2,4-dimethylphenoxymethyl) benzene, 1,3 bis (2,6-dimethylphenoxymethyl) benzene, 1,4- bis (2-chlorophenoxymethyl) benzene, 1,2-bis (4-chlorophenoxymethyl) benzene, 1,3-bis (4-chlorophenoxymethyl) benzene, 1,2-bis (4-octylphenoxymethyl) benzene, 1,3-bis ( 4-octylphenoxymethyl) benzene, 1,3-bis (4-isopropylphenylphenoxymethyl) benzene and 1,4-bis (4-isopropylphenylphenoxymethyl) benzene.

The above-mentioned heat-melting substances may be used singly or in combination. The amount of addition of the heat-melting substance (s) in the entire imaging layers should preferably be 0.5 to 50% by weight based on the total solid amount of the entire imaging layers. The ratio of the contained heat-melting substance (s) with respect to the water-soluble polymer compound (s) in the image-forming layer (A) should preferably be higher than the corresponding ratio in the image-forming layer (B).

These heat-melting substances are solid at room temperature. In order to increase their ability to react to heat, these heat-melting substances should preferably be used micro-dispersed. The microdispersion can be carried out by the customary in the production of coating compositions Nassdispergierug, for which u. a. a roller mill, colloid mill, ball mill, attritor or bead mill such as sand mill can be used. As beads for the bead mill u. a. Ceramic beads of zirconia, titania or alumina, metal beads of chrome or steel or glass beads can be used. The dispersion particle diameter of the heat-melting substance (s) to be obtained by the micro-dispersion should be advantageously 0.1 to 1.2 μm in median diameter, with a diameter of 0.3 to 0.8 μm being more preferable. Here, the median diameter is defined as the particle diameter at the point where the cumulative curve reaches 50%, which is calculated as 100% from the total volume of a group of particles (cumulative mean diameter), and may be one of the parameters to evaluate the particle size distribution u. a. be determined by means of the laser diffractometry / scattering particle size distribution meter LA920 (manufacturer: Horiba AG).

The imaging layers of the thermosensitive lithographic printing plate according to i) may contain color developers and color formers (electron donating dye precursors), such as phenol derivatives or aromatic carboxylic acid derivatives, which are used in the conventional thermosensitive or pressure-sensitive recording papers to ensure visibility.

Specific examples of the color developer are exemplified: phenolic compounds such as 4-cumylphenol, hydroquinone monobenzyl ether, 4,4'-isopropylidenediphenol, 1,1-bis (4-hydroxyphenyl) cyclohexane, 4,4'-dihydroxydiphenyl-2,2-butane, 4,4'-dihydroxydiphenylmethane, 2,2-bis (4-hydroxyphenyl) -4-methylpentane, 2,2-bis (4-hydroxyphenyl) heptane, bis (4-hydroxyphenylthioethoxy) methane, 1,5-di (4- hydroxyphenylthio) -3-oxapentane, 1,1-bis (4-hydroxyphenyl) -1-phenylethane, 1,4-bis [α-methyl-α- (4'-hydroxyphenyl) ethyl] benzene, 1,3-bis [ α-methyl-α- (4'-hydroxyphenyl) ethyl] benzene, 4,4'-dihydroxydiphenylsulfide, di (4-hydroxy-3-methylphenyl) sulfone, 4-hydroxy-4'-methyldiphenylsulfone, 4-hydroxy-4 ' -isopropoxydiphenylsulfone, 2,4'-dihydroxydiphenylsulfone, 4,4'-dihydroxydiphenylsulfone, bis (3-allyl-4-hydroxyphenyl) sulfone, 4-hydroxyphenyl-4'-benzyloxyphenylsulfone, 4-hydroxy-3 ', 4'-tetramethylenebiphenylsulfone, 3,4-dihydroxyphenyl-p-tolylsulfone, 4,4'- dihydroxybenzophenone, 4-hydroxybenzylbenzoate, N, N'-di-m-chlorophenylthiourea and N- (phenoxyethyl) -4-hydroxyphenylsulfonamide; Zinc salts of the aromatic carboxylic acid such as 4- [3- (p-tolylsulfonyl) propyloxy] zinc salicylate, 4 - [- 2- (p-methoxyphenoxy) ethyloxy] zinc salicylate, 5-methoxyphenoxyethoxy) cumyl] zinc salicylate and p-chlorozincbenzoate; and finally, organic acidic substances such as zinc thiocyanate antipyrine complex

And as concrete examples of the color former (electron-donating dye precursor), u. a. to name: (1) triarylmethane compounds u. a. in the form of 3,3'-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide (crystal violet lactone), 3,3'-bis (p-dimethylaminophenyl) phthalide, 3- (p-dimethylaminophenyl) -3- (1,2- dimethylindol-3-yl) phthalide, 3- (p-dimethylaminophenyl) -3- (2-methylindol-3-yl) phthalide, 3- (p-dimethylaminophenyl) -3- (2-phenylindol-3-yl) phthalide, 3,3-bis (1,2-dimethylindol-3-yl) -5-dimethylaminophthalide, 3,3-bis (1,2-dimethylindol-3-yl) -6-dimethylaminophthalide, 3,3-bis (9- ethylcarbazol-3-yl) -5-dimethylaminophthalide, 3,3-bis (2-phenylindol-3-yl) -5-dimethylaminophthalide and 3-p-dimethylaminophenyl-3- (1-methylpyrrol-2-yl) -6- dimethyl-aminophthalide; (2) diphenylmethane compounds and the like a. in the form of 4,4'-bis-dimethylaminobenzhydrin benzyl ether, N-halophenylleucoauramine and N-2,4,5-trichlorophenylleucoauramine; (3) xanthene compounds and the like a. in the form of rhodamine-B-anilinolactam, rhodamine-Bp-nitroanilinolactam, rhodamine-Bp-chloroanilinolactam, 3-diethylamino-7-dibenzylaminofluoran, 3-diethylamino-7-octylaminofluoran, 3-diethylamino-7-phenylfluoran, 3-diethylamino-7 - (3,4-dichloroanilino) fluoran, 3-diethylamino-7- (2-chloroanilino) fluoran, 3-diethylamino-6-methyl-7-anilinofluoran, 3-dibutylamino-6-methyl-7-anilinofluoran, 3-piperidino-6 -methyl-7-anilinofluoran, 3-ethyl-tolylamino-6-methyl-7-anilinofluoran, 3-ethyl-tolylamino-6-methyl-7-phenethylfluoran and 3-diethylamino-7- (4-nitroanilino) -fluoran; (4) thiazine compounds and the like a. in the form of benzoylleucomethylene blue and p-nitrobenzoylleucomethylene blue; (5) spiro compounds and the like a. in the form of 3-methyl-spiro-dinaphthopyran, 3-ethyl-spiro-dinaphthopyran, 3,3'-dichloro-spiro-dinaphthopyran, 3-benzyl-spiro-dinaphthopyran, 3-methyl-naphtho- (3-methoxy-benzo) - spiropyran and 3-propyl-spiro-dibenzopyran. Incidentally, these may be used singly or in combination of 2 or more varieties.

In addition, the imaging layers may also contain photothermal substances. The photothermal substances contained make writing not only possible with a thermal head but also with an active light such as an infrared laser. As an example of the photothermal substance, a material which absorbs the light with good efficiency and converts it into heat is advantageous. Although it is different depending on the light source used, but in a near-infrared light-emitting semiconductor laser as a light source, for example, a near infrared light absorbing agent having an absorption band in the near infrared is advantageous as the photothermal substance, and as such, for example, organic compounds such as, for example, are mentioned. a. Carbon black, cyanine pigment, polymethine pigment, azulenium pigment, squarylium pigment, thiopyrylium pigment, naphthoquinone pigment and anthraquinone pigment, organometallic phthalocyanine, azo and thioamide complexes or metal compounds, such as. a. Iron powder, graphite powder, iron oxide powder, lead oxide, silver oxide, chromium oxide, iron sulfide and chromium sulfide.

The application amount of the entire imaging layers comprising the thermosensitive lithographic printing plate according to i) should preferably be 0.5 to 30 g / m ² of dry solids from the viewpoints of print life of image areas, water resistance and mechanical strength of non-image sites.

Now, the imaging layers of the thermosensitive lithographic printing plate will be explained, which satisfies the condition ii). A thermosensitive lithographic printing plate according to ii) comprises on a waterproof support at least 2 layers of imaging layers containing water-soluble polymer compound (s) and thermoplastic resin (s), the ratio of at least one of the compound to be selected from the following general formulas (1) to (4), based on the water-soluble polymer compound (s) (ie, the mass of at least one compound selected from the compounds represented by the general formulas (1) to (4)) the mass of the water-soluble polymer compound (s)) in the imaging layer (A) closer to the waterproof support than the imaging layer (B) is higher than the corresponding ratio in the imaging layer (B) furthest from the waterproof support. By forming at least 2 layers of imaging layers in this design, a thermosensitive lithographic printing plate can be provided which, in addition to high press life and tone free (water retention), provides improvements in print defects due to head deposition and the image disturbance by the sticking appearance brings with it.

The reason why the thermosensitive lithographic printing plate according to ii) obtains good printing life and tone-free property (water holding capacity) and also provides a thermosensitive lithographic printing plate which brings about improvements in printing defects due to the head deposit and image disturbance by the sticking phenomenon, is not clear, but the following is suspected.

The thermosensitive lithographic printing plate according to ii) has imaging layers which use the thermal phase change to change to hydrophobicity. The layer referred to here, which changes to hydrophobicity, is a layer whose parts melt under the action of heat and change to hydrophobicity, while the parts retain the hydrophilicity which the original layer has without the action of heat. Specifically, when changing the heat-melting parts of the imaging layer to hydrophobicity, the thermoplastic resin buried in the water-soluble polymer compound exits to the surface of the layer, thus developing the hydrophobicity. In the non-printed areas, d. H. however, the non-image sites remain buried in the water-soluble polymer compound, so that no hydrophobicity develops. In this way, the difference arises hydrophobic-hydrophilic between the image sites and the non-image sites. In order to improve the press life and tonelessness (water holding capacity) of this thermosensitive lithographic printing plate, it is important to maintain this difference sufficiently even during printing. In the invention, apparently, by a lower ratio of the compound (s) represented by the general formulas (1) to (4) with respect to the water-soluble polymer compound (s) in the imaging layer (B) furthest from the waterproof carrier. the hydrophilicity of the surface can be increased, thereby improving the water holding capacity in printing, while at the same time reducing the hydrophobicity in the image areas by the formation of an imaging layer (A) having a higher ratio of those represented by the general formulas (1) to (4) Compound (s) than the imaging layer (B) and is closer to the waterproof carrier is overcome. As a result, presumably, in the heat transfer imaging, the temperature at which the thermoplastic resin in the imaging layer (A) begins to melt is lowered so that it melts with less energy and exits to the surface of the image spots, resulting in high temperatures Pressure life and tone freedom (water retention) can be combined. In addition, in a thermosensitive lithographic printing plate for the direct thermal imaging plate-making process, excellent effects are obtained by adding the compound (s) represented by the general formulas (1) to (4) into the imaging layer at the temperature at which the thermoplastic resin in the imaging layer begins to melt, so as to improve the sticking, and lower ratio of the compound (s) represented by the general formulas (1) to (4) relative to the water-soluble (s) Polymer compound (s) in the imaging layer (B) furthest from the waterproof support which comes into direct contact with the thermal head also provide improvements in image distortion due to head deposition.

In the thermosensitive lithographic printing plate of (ii), there is no limitation on the method of producing thermosensitive lithographic printing plates characterized by the ratio of the compound (s) represented by the general formulas (1) to (4) with respect to water-soluble polymer compound (s) in the image-forming layer (A) is higher than the corresponding ratio in the image-forming layer (B), for example, a method of first applying the image-forming layer (A) and then applying the image-forming layer (B) is applied to the rich or a method in which several layers are applied at once in the slide-hopper process.

wobei X₁ -O- oder -C -O-O- darstellt,
R₁, R₂ und R₃ unabhängig voneinander jeweils ein Wasserstoffatom, eine Alkylgruppe oder Arylgruppe darstellen- oder- R₁, R₂ und R₃ miteinander verbunden einen aromatischen Ring bilden können,
R₄, R₅ und R₆ unabhängig voneinander jeweils ein Wasserstoffatom, eine Alkylgruppe oder Arylgruppe darstellen- oder- R₄, R₅ und R₆ miteinander verbunden einen aromatischen Ring bilden können und
n eine ganze Zahl von 1 bis 10 darstellt.The imaging layers of the thermosensitive lithographic printing plate according to ii) contain at least one compound to be selected from the compounds represented by the general formulas (1) to (4). In the following, the compounds represented by the general formula (1) will be explained. [Chemical formula 5]

where X _{1 represents} -O- or -C-O-,
R ₁ , R ₂ and R _3, independently of one another, each represent a hydrogen atom, an alkyl group or an aryl group, or R ₁ , R ₂ and R ₃ can form an aromatic ring connected to one another,
R ₄ , R ₅ and R _6, independently of one another, each represent a hydrogen atom, an alkyl group or an aryl group, or R ₄ , R ₅ and R _{6, joined} together, can form an aromatic ring and
n represents an integer from 1 to 10.

In a preferred embodiment of the invention, the compound represented by the general formula (1) represents a compound in which X _{1 is} -O-. In a more preferred embodiment of the present invention, the compound represented by the general formula (1) represents a compound wherein R ₁ and R _{6 are} a hydrogen atom or an alkyl group having a carbon number of 1 to 4, R ₂ , R ₃ , R ₄ and R ₅ are a hydrogen atom and n is an integer from 1 to 4.

• (1) 1-(1-naphthoxy)-2-phenoxyethan;
• (2) 1-(2-naphthoxy)-4-phenoxybutan;
• (3) 1-(2-isopropylphenoxy)-2-(2-naphthoxy)ethan;
• (4) 1-(4-methylphenoxy)-3-(2-naphthoxy)propan;
• (5) 1-(2-methylphenoxy)-2-(2-naphthoxy)ethan;
• (6) 1-(3-methylphenoxy)-2-(2-naphthoxy)ethan;
• (7) 1-(2-naphthoxy)-2-phenoxyethan;
• (8) 1-(2-naphthoxy)-6-phenoxyhexan;
• (9) 1-phenoxy-2-(2-phenylphenoxy)ethan;
• (10) 1-(2-methylphenoxy)-2-(4-phenylphenoxy)ethan;
• (11) 1,4-diphenoxybutan;
• (12) 1,4-bis(4-methylphenoxy)butan;
• (13) 1,2-di(3,4-dimethylphenoxy)ethan;
• (14) 1-phenoxy-3-(4-phenylphenoxy)propan;
• (15) 1-(4-tert-butylphenoxy)-2-phenoxyethan;
• (16) 1,2-diphenoxyethan;
• (17) 1-(4-methylphenoxy)-2-phenoxyethan;
• (18) 1-(2,3-dimethylphenoxy)-2-phenoxyethan;
• (19) 1-(3,4-dimethylphenoxy)-2-phenoxyethan;
• (20) 1-(4-ethylphenoxy)-2-phenoxyethan;
• (21) 1-(4-isopropylphenoxy)-2-phenoxyethan;
• (22) 1,2-bis(2-methylphenoxy)ethan;
• (23) 1-(2-methylphenoxy)-2-(4-methylphenoxy)ethan;
• (24) 1-(4-tert-butylphenoxy)-2-(2-methylphenoxy)ethan;
• (25) 1,2-bis(3-methylphenoxy)ethan;
• (26) 1-(3-methylphenoxy)-2-(4-methylphenoxy)ethan;
• (27) 1-(4-ethylphenoxy)-2-(3-methylphenoxy)ethan;
• (28) 1,2-bis(4-methylphenoxy)ethan;
• (29) 1-(2,3-dimethylphenoxy)-2-(4-methylphenoxy)ethan;
• (30) 1-(2,5-dimethylphenoxy)-2-(4-methylphenoxy)ethan;
• (31) Phenoxyessigsäure-2-naphthyl;
• (32) 2-naphthoxyessigsäure-4-methylphenyl; und
• (33) 2-naphthoxyessigsäure-3-methylphenyl.

As the corresponding compounds represented by the general formula (1), inter alia, the following compounds are exemplified without the invention being restricted thereto:

• (1) 1- (1-naphthoxy) -2-phenoxyethane;
• (2) 1- (2-naphthoxy) -4-phenoxybutane;
• (3) 1- (2-isopropylphenoxy) -2- (2-naphthoxy) ethane;
• (4) 1- (4-methylphenoxy) -3- (2-naphthoxy) propane;
• (5) 1- (2-methylphenoxy) -2- (2-naphthoxy) ethane;
• (6) 1- (3-methylphenoxy) -2- (2-naphthoxy) ethane;
• (7) 1- (2-naphthoxy) -2-phenoxyethane;
• (8) 1- (2-naphthoxy) -6-phenoxyhexane;
• (9) 1-phenoxy-2- (2-phenylphenoxy) ethane;
• (10) 1- (2-methylphenoxy) -2- (4-phenylphenoxy) ethane;
• (11) 1,4-diphenoxybutane;
• (12) 1,4-bis (4-methylphenoxy) butane;
• (13) 1,2-di (3,4-dimethylphenoxy) ethane;
• (14) 1-phenoxy-3- (4-phenylphenoxy) propane;
• (15) 1- (4-tert-butylphenoxy) -2-phenoxyethane;
• (16) 1,2-diphenoxyethane;
• (17) 1- (4-methylphenoxy) -2-phenoxyethane;
• (18) 1- (2,3-dimethylphenoxy) -2-phenoxyethane;
• (19) 1- (3,4-dimethylphenoxy) -2-phenoxyethane;
• (20) 1- (4-ethylphenoxy) -2-phenoxyethane;
• (21) 1- (4-isopropylphenoxy) -2-phenoxyethane;
• (22) 1,2-bis (2-methylphenoxy) ethane;
• (23) 1- (2-methylphenoxy) -2- (4-methylphenoxy) ethane;
• (24) 1- (4-tert-butylphenoxy) -2- (2-methylphenoxy) ethane;
• (25) 1,2-bis (3-methylphenoxy) ethane;
• (26) 1- (3-methylphenoxy) -2- (4-methylphenoxy) ethane;
• (27) 1- (4-ethylphenoxy) -2- (3-methylphenoxy) ethane;
• (28) 1,2-bis (4-methylphenoxy) ethane;
• (29) 1- (2,3-dimethylphenoxy) -2- (4-methylphenoxy) ethane;
• (30) 1- (2,5-dimethylphenoxy) -2- (4-methylphenoxy) ethane;
• (31) phenoxyacetic acid 2-naphthyl;
• (32) 2-naphthoxyacetic acid 4-methylphenyl; and
• (33) 2-Naphthoxyacetic acid 3-methylphenyl.

wobei R₇ eine Alkylgruppe, Arylgruppe, Alkylcarbonylgruppe, Arylcarbonylgruppe, Alkylsulfonylgruppe oder Arylsulfonylgruppe darstellt. Dabei kann der Naphthalenring gemäß der Formel weitere Substituenten aufweisen, wobei als Beispiele der bevorzugten Substituenten u. a. eine Alkylgruppe, Arylgruppe, Halogenatom, Hydroxygruppe, Alkoxygruppe, Aryloxygruppe, Alkyloxycarbonylgruppe, Alkoxycarbonylgruppe, Aryloxycarbonylgruppe, Carbamoylgruppe und Sulfamoylgruppe zu nennen sind.Now, the compounds represented by the general formula (2) will be explained. [Chemical formula 6]

wherein R _{7 represents} an alkyl group, aryl group, alkylcarbonyl group, arylcarbonyl group, alkylsulfonyl group or arylsulfonyl group. Here, the naphthalene ring according to the formula may have further substituents, examples of preferred substituents being, inter alia, an alkyl group, aryl group, halogen atom, hydroxy group, alkoxy group, aryloxy group, alkyloxycarbonyl group, alkoxycarbonyl group, aryloxycarbonyl group, carbamoyl group and sulfamoyl group.

In a preferred embodiment of the invention, the compound represented by the above-mentioned general formula (2) represents a compound wherein R _{7 is} an alkyl group having a carbon number of 4 to 20, an aryl group having a carbon number of 4 to 24, an alkylcarbonyl group having a carbon number of 2 to 20 or arylcarbonyl group having a carbon number of 7 to 20. In a more preferred embodiment of the present invention, the compound represented by the above-mentioned general formula (2) represents a compound in which the substituent which the naphthalene ring may additionally have is a halogen atom, alkyl group having a carbon number of 1 to 10, alkyloxycarbonyl group having a carbon number from 2 to 20, aryloxycarbonyl group having a carbon number of 7 to 20 or carbamoyl group having a carbon number of 2 to 25.

• (1) 1-benzyloxynaphthalen;
• (2) 2-benzyloxynaphthalen;
• (3) 2-p-chlorbenzyloxynaphthalen;
• (4) 2-p-isopropylbenzyloxynaphthalen;
• (5) 2-dodecyloxynaphthalen;
• (6) 2-decanoyloxynaphthalen;
• (7) 2-myristoyloxynaphthalen;
• (8) 2-p-tert-Butylbenzoyloxynaphthalen;
• (9) 2-benzoyloxynaphthalen;
• (10) 2-benzyloxy-3-N-(3-dodecyloxypropyl)carbamoylnaphthalen;
• (11) 2-benzyloxy-3-N-octylcarbamoylnaphthalen;
• (12) 2-benzyloxy-3-dodecyloxycarbonylnaphthalen; und
• (13) 2-benzyloxy-3-p-tert-butylphenoxycarbonylnaphthalen.

As the corresponding compounds represented by the general formula (2), inter alia, the following compounds are exemplified without the invention being restricted thereto:

• (1) 1-benzyloxynaphthalene;
• (2) 2-benzyloxynaphthalene;
• (3) 2-p-chlorobenzyloxynaphthalene;
• (4) 2-p-isopropylbenzyloxynaphthalene;
• (5) 2-dodecyloxynaphthalene;
• (6) 2-decanoyloxynaphthalene;
• (7) 2-myristoyloxynaphthalene;
• (8) 2-p-tert-butylbenzoyloxynaphthalene;
• (9) 2-benzoyloxynaphthalene;
• (10) 2-benzyloxy-3-N- (3-dodecyloxypropyl) carbamoylnaphthalene;
• (11) 2-benzyloxy-3-N-octylcarbamoylnaphthalene;
• (12) 2-benzyloxy-3-dodecyloxycarbonylnaphthalene; and
• (13) 2-benzyloxy-3-p-tert-butylphenoxycarbonylnaphthalene.

wobei R₈ und R₉ unabhängig voneinander jeweils ein Wasserstoffatom, Halogenatom, eine Alkylgruppe mit einer Kohlenstoffzahl von 1 bis 4 oder Alkoxygruppe mit einer Kohlenstoffzahl von 1 bis 4 darstellen,
X₂ eine Einfachbindung oder -O- darstellt und
n eine ganze Zahl von 1 bis 4 darstellt.Now, the compounds represented by the general formula (3) will be explained. [Chemical formula 7]

wherein R ₈ and R ₉ independently of one another each represent a hydrogen atom, halogen atom, an alkyl group having a carbon number of 1 to 4 or alkoxy group having a carbon number of 1 to 4,
X _{2 represents} a single bond or -O- and
n represents an integer from 1 to 4.

• (1) Oxalsäure-bisbenzyl;
• (2) Oxalsäure-bis(p-methylbenzyl);
• (3) Oxalsäure-bis(p-chlorbenzyl);
• (4) Oxalsäure-bis(m-methylbenzyl);
• (5) Oxalsäure-bis(p-ethylbenzyl);
• (6) Oxalsäure-bis(p-methoxybenzyl);
• (7) Oxalsäure-bis(2-phenoxyethyl);
• (8) Oxalsäure-bis(2-o-chlorphenoxyethyl);
• (9) Oxalsäure-bis(2-p-chlorphenoxyethyl);
• (10) Oxalsäure-bis(2-p-ethylphenoxyethyl);
• (11) Oxalsäure-bis(2-m-methoxyphenoxyethyl);
• (12) Oxalsäure-bis(2-p-methoxyphenoxyethyl); und
• (13) Oxalsäure-bis(4-phenoxybutyl).

As the corresponding compounds represented by the general formula (3), inter alia, the following compounds are exemplified without the invention being restricted thereto:

• (1) oxalic bisbenzyl;
• (2) oxalic-bis (p-methylbenzyl);
• (3) oxalic-bis (p-chlorobenzyl);
• (4) oxalic-bis (m-methylbenzyl);
• (5) bis (p-ethylbenzyl) oxalic acid;
• (6) oxalic bis (p-methoxybenzyl);
• (7) oxalic acid bis (2-phenoxyethyl);
• (8) oxalic acid bis (2-o-chlorophenoxyethyl);
• (9) oxalic acid bis (2-p-chlorophenoxyethyl);
• (10) oxalic acid bis (2-p-ethylphenoxyethyl);
• (11) oxalic acid bis (2-m-methoxyphenoxyethyl);
• (12) oxalic acid bis (2-p-methoxyphenoxyethyl); and
• (13) oxalic acid bis (4-phenoxybutyl).

As specific preferable examples among these exemplified compounds are oxalic bisbenzyl, bis (p-methylbenzyl) oxalic acid, bis (p-chlorobenzyl) oxalic acid, bis (m-methylbenzyl) oxalic acid, bis (p-ethylbenzyl) oxalic acid, and bis To call oxalic acid bis (p-methoxybenzyl).

wobei R₁₀, R_10', R₁₁ und R_11' unabhängig voneinander jeweils ein Wasserstoffatom, Halogenatom, eine Alkylgruppe, Arylgruppe, Alkoxygruppe, Alkylcarbonylgruppe, Arylcarbonylgruppe, Alkoxycarbonylgruppe oder Aryloxygruppe darstellen.In the following, the compounds represented by the general formula (4) will be explained. [Chemical formula 8]

wherein R ₁₀ , R _{10 '} , R ₁₁ and R _11' each independently represent a hydrogen atom, halogen atom, an alkyl group, aryl group, alkoxy group, alkylcarbonyl group, arylcarbonyl group, alkoxycarbonyl group or aryloxy group.

• (1) 1,2-bisphenoxymethylbenzen
• (2) 1,3-bisphenoxymethylbenzen:
• (3) 1,4-bis(2-methylphenoxymethyl)benzen;
• (4) 1,4-bis(3-methylphenoxymethyl)benzen;
• (5) 1,3-bis(4-methylphenoxymethyl)benzen;
• (6) 1,3-bis(2,4-dimethylphenoxymethyl)benzen;
• (7) 1,3-bis(2,6-dimethylphenoxymethyl)benzen;
• (8) 1,4-bis(2-chlorphenoxymethyl)benzen;
• (9) 1,2-bis(4-chlorphenoxymethyl)benzen;
• (10) 1,3-bis(4-chlorphenoxymethyl)benzen;
• (11) 1,2-bis(4-octylphenoxymethyl)benzen;
• (12) 1,3-bis(4-octylphenoxymethyl)benzen;
• (13) 1,3-bis(4-isopropylphenylphenoxymethyl)benzen; und
• (14) 1,4-bis(4-isopropylphenylphenoxymethyl)benzen.

As the corresponding compounds represented by the general formula (4), inter alia, the following compounds are exemplified without the invention being restricted thereto:

• (1) 1,2-bisphenoxymethylbenzene
• (2) 1,3-bisphenoxymethylbenzene:
• (3) 1,4-bis (2-methylphenoxymethyl) benzene;
• (4) 1,4-bis (3-methylphenoxymethyl) benzene;
• (5) 1,3-bis (4-methylphenoxymethyl) benzene;
• (6) 1,3-bis (2,4-dimethylphenoxymethyl) benzene;
• (7) 1,3-bis (2,6-dimethylphenoxymethyl) benzene;
• (8) 1,4-bis (2-chlorophenoxymethyl) benzene;
• (9) 1,2-bis (4-chlorophenoxymethyl) benzene;
• (10) 1,3-bis (4-chlorophenoxymethyl) benzene;
• (11) 1,2-bis (4-octylphenoxymethyl) benzene;
• (12) 1,3-bis (4-octylphenoxymethyl) benzene;
• (13) 1,3-bis (4-isopropylphenylphenoxymethyl) benzene; and
• (14) 1,4-bis (4-isopropylphenylphenoxymethyl) benzene.

As specific preferable examples among these exemplified compounds are 1,2-bisphenoxymethylbenzene, 1,4-bis (2-methylphenoxymethyl) benzene, 1,4-bis (3-methylphenoxymethyl) benzene and 1,4-bis (2-chlorophenoxymethyl) to name benzen. The addition amount of the compound (s) represented by the general formulas (1) to (4) in the entire imaging layers should preferably be 30 to 130% by weight based on the amount of the thermoplastic resin (s) in the entire imaging layers. These compounds can either be used alone or combined with other heat-melting substances.

The compounds represented by the above-mentioned general formulas (1) to (4) are in the solid state at room temperature. In order to increase their ability to react to heat, these compounds should preferably be used in a microdispersed manner. The microdispersion can be carried out by the customary in the production of coating compositions Nassdispergierug, for which u. a. a roller mill, colloid mill, ball mill, attritor or bead mill such as sand mill can be used. As beads for the bead mill u. a. Ceramic beads of zirconia, titania or alumina, metal beads of chrome or steel or glass beads can be used. The dispersion particle diameter of the compound (s) to be obtained by the microdispersion should be advantageously 0.1 to 1.2 μm in median diameter, with a diameter of 0.3 to 0.8 μm being more preferable. Here, the median diameter is defined as the particle diameter at the point where the cumulative curve reaches 50%, which is calculated as 100% from the total volume of a group of particles (cumulative mean diameter), and may be one of the parameters to evaluate the particle size distribution u. a. be determined by means of the laser diffractometry / scattering particle size distribution meter LA920 (manufacturer: Horiba AG).

The ratio of the compound (s) represented by the general formulas (1) to (4) with respect to the water-soluble polymer compound (s) (the mass of the compound (s) represented by the general formulas (1) to (4) the mass of the water-soluble polymer compound (s)) in the imaging layer (B) furthest from the waterproof support should preferably be 0 to 0.5. The ratio of the compound (s) represented by the general formulas (1) to (4) with respect to the water-soluble polymer compound (s) (the mass of the compound (s) represented by the general formulas (1) to (4) the mass of the water-soluble polymer compound (s)) in the imaging layer (A) closer to the waterproof carrier should preferably be 1.0 or more.

In the thermosensitive lithographic printing plate according to ii), the ratio of the compound (s) represented by the general formulas (1) to (4) relative to the water-soluble polymer compound (s) in the image-forming layer (A) can be arbitrarily set as long as it is higher is as the corresponding ratio in the imaging layer (B), and the difference between the corresponding ratio in the imaging layer (A) and the corresponding ratio in the imaging layer (B) should preferably be 1.0 or more.

When three layers of imaging layers are formed in the thermosensitive lithographic printing plate of (ii), an imaging layer (C) may be formed between the imaging layer (A) and the imaging layer (B). The ratio of the compound (s) represented by the general formulas (1) to (4) relative to the water-soluble polymer compound (s) in the image-forming layer (C) may be higher or lower than the corresponding ratio in the image-forming layer (B ), but should preferably be lower than the corresponding ratio in the imaging layer (A) and higher than the corresponding ratio in the imaging layer (B).

The imaging layers of the thermosensitive lithographic printing plate of (ii) include thermoplastic resin (s). As the thermoplastic resin, mention may be made of the same resins as the corresponding thermoplastic resins mentioned above in the present specification which contain the imaging layers of the thermosensitive lithographic printing plate of i). These thermoplastic resins may be used singly or in combination of two or more kinds. Because of the compatibility with the vehicle (binder) of printing inks, the synthetic rubber latices are preferable as the thermoplastic resin, in particular, styrene-butadiene copolymer and its modifications are preferable. The addition amount of the thermoplastic resin (s) in the entire imaging layers should preferably be 5 to 50% by weight based on the solid amount of the entire imaging layers.

Further, in order for the thermal melting and fusion bonding effect to be easily exhibited, a glass transition temperature of the thermoplastic resin of 50 to 150 ° C is advantageous; even more advantageous 55 to 120 ° C. At a glass transition temperature lower than 50 ° C, the phase change to liquid state occurs during the manufacturing process, whereby the hydrophobicity also develops in the non-image areas, which can cause the toning of the prints. At a glass transition temperature higher than 150 ° C, the thermal melting of the polymer is difficult to occur, so that it may be difficult to achieve robust imaging by means of a laser with a relatively small power or a small thermal printer.

The imaging layers of the thermosensitive lithographic printing plate according to ii) contain (a) water-soluble polymer compound (s). As the water-soluble polymer compound, mention is made of the same compounds as the water-soluble polymer compounds containing the imaging layers of the thermosensitive lithographic printing plate of i). The water-soluble polymer compounds may be used singly or in combination of two or more kinds. In particular, because of their rich film formation, gelatin, polyvinyl alcohol and their modifications are favorable for the maintenance of the hydrophilicity of the non-image sites, therefore, they are selected. The addition amount of the water-soluble polymer compound (s) in the entire imaging layers should preferably be 0.5 to 50% by weight based on the total solid amount of the entire imaging layers.

Further, the imaging layers for increasing the water resistance and the mechanical strength of the non-image sites corresponding to the selected said water-soluble polymer compound contain curing agents (water resistance agents). As the curing agent to be used, there are the same agents as the above-mentioned curing agents containing the imaging layers of the thermosensitive lithographic printing plate according to i). For gelatin as the water-soluble polymer compound, divinyl sulfone is preferably used as the curing agent, while polyvinyl alcohol is used as the water-soluble one Polymer compound preferably glyoxal is used as a curing agent. The amount of addition of the curing agent in the entire imaging layers should preferably be 0.01 to 30% by weight based on the solid amount of the water-soluble polymer compound (s) contained in the entire imaging layers, with an addition amount of 5 to 30% by weight being more preferable ,

The imaging layers comprising the thermosensitive lithographic printing plate of (ii) may contain heat-melting substance (s) besides the compound (s) represented by the general formulas (1) to (4). As the heat-melting substances, organic compounds having a melting point of 50 to 150 ° C are advantageous, for example, wax such as carnauba wax, microcrystalline wax, paraffin wax and polyethylene wax, fatty acid such as lauric acid, stearic acid, oleic acid, palmitic acid, behenic acid and montanic acid and their esters or amides can be used. The amount of addition of the heat-melting substance (s) in the entire imaging layers should preferably be 0.5 to 50% by weight based on the total solid amount of the imaging layers.

The thermosensitive lithographic printing plate according to ii), to ensure visibility color developer and color former (electron-donating dye precursors) such as phenol derivatives or aromatic carboxylic acid derivatives used in the conventional thermosensitive or pressure-sensitive recording papers are used. As the color developer or color former to be used, mention may be made of the same agents as the above-mentioned color developers or color formers which contain the imaging layers of the thermosensitive lithographic printing plate according to i).

In addition, photo-thermal substances may be added to the imaging layers comprising the thermosensitive lithographic printing plate of (ii). By using photothermal substances, writing is possible not only with a thermal head but also with an active light such as infrared laser. As examples of the photothermal substance, mention may be made of the same substances as the above-mentioned photothermal substances containing the imaging layers of the thermosensitive lithographic printing plate according to i).

The application amount of the entire imaging layers comprising the thermosensitive lithographic printing plate according to (ii) should preferably be from 0.5 to 30 g / m ² of dry solids from the viewpoints of print life of image areas, water resistance and mechanical strength of non-image sites.

The imaging layer (B) furthest from the waterproof support of the above-described thermosensitive lithographic printing plate satisfying the requirement i) and / or ii) may contain zinc oxide or barium sulfate. Thereby, a thermosensitive lithographic printing plate can be provided, in which the printing life and the tone freedom (water retention capacity) are balancedly improved.

<Zinc oxide>

Zinc oxide is classified according to its production process in dry and wet process, wherein there are the French and the American process under the dry process, while under the wet process u. a. the German method is widely known. The French process is a process in which high-purity metallic zinc is heated and the resulting zinc vapor is burned in an oxidative atmosphere, forming zinc oxide. In contrast, in the American process, zinc ore (Franknit) is roasted with the addition of reducing agents, such as coke, and zinc oxide is formed by the air oxidation of the resulting zinc vapor. And under the wet process, there is the process with the pyrolysis of zinc salt such. Zinc carbonate, the method of precipitating zinc oxide directly in an alkaline solution of zinc salt which is neutralized with acid, and the method of precipitating zinc oxide directly in an acidic solution of zinc salt which is neutralized in alkali. In general, the preparation is carried out by the reaction of the acidic solution of zinc salt (zinc sulfate or zinc chloride solution) with alkali such as calcined soda, washing-filter-drying and subsequent firing and crushing. Zinc oxide produced by these methods is e.g. a. from Seido Chemical Industry AG, Sakai Chemical AG, Hakusui-Tech AG, Honjo Chemical AG and Toho Zinc AG and can be used in the invention.

<Barium sulfate>

Of barium sulfate, there are elutriation barium sulfate (barite powder) obtained by crushing, deicing, washing and elutriation of barite, and precipitating barium sulfate which is chemically precipitated by the addition of aqueous sulfate solution in barium chloride solution. Barium sulfate, which is produced by these methods, for example u. a. from Sakai Chemical AG, Takehara Kagaku Kogyo AG and HakusuiTech AG and can be used in the invention. In addition, barium sulfate may be subjected to particle formation in an after-treatment of the organic polymer treatment or surface treatment with a hydroxide or oxide of one of the metallic elements Al, Si and Zr or with a phosphate of one of the metallic elements Mg, Ca, Sr and Ba.

If the average particle diameter of zinc oxide or barium sulfate is too large, the contact area may be unfavorably reduced by the direct contact of the thermal head on the imaging layer (B). The reduction of the contact area leads to the decrease of the thermal efficiency and can bring about the reduction of the press life. On the other hand, if the average particle diameter of zinc oxide or barium sulfate is too small, it will lower the effect of press life and freedom from toning (water holding capacity), and if the contact area is excessively increased depending on the particle diameter of zinc oxide or barium sulfate, it may deteriorate the peel behavior, which may lead to less resistance to sticking. It follows that the average particle diameter of the zinc oxide or barium sulfate to be used in the invention should advantageously be in the range of 0.1 to 1.0 μm, with 0.2 to 0.5 μm being more advantageous.

The form of the zinc oxide or barium sulfate to be used in the invention may be amorphous, plate-shaped, rod-shaped or granular, but should preferably be amorphous.

The content of the zinc oxide or barium sulfate contained in the image-forming layer (B) should preferably be 8 to 26% by weight based on the amount of the thermoplastic resin (s) contained in the image-forming layer (B). As a result, the pressure life and freedom from sound (water retention) can be combined at a higher level. Further, zinc oxide or barium sulfate based on the total amount of the thermoplastic resin (s) contained in the imaging layers (A) and (B) should desirably be used in the range of at most 5% by weight.

<Primer layer>

According to the invention, between the imaging layer (A) and the waterproof carrier, a primer layer containing at least titanium dioxide whose average particle diameter is smaller than the average dry film thickness of the undercoat layer, binder resin and crosslinking agent may be formed. This can provide a thermosensitive lithographic printing plate whose scratch resistance is improved without compromising image quality or printing life, and which does not require the so-called debris removal during ablation or development in the printing press.

The scratch resistance in the invention is effective not only against scratch marks in the surface of the manufacturing process and the image forming process, but also against the deterioration due to scratch marks generated during printing. The scratch marks generated during printing occur because the slight unevenness formed on the blanket roll causes localized changes in the compressive stress and, as a result, scratches the plate surface, resulting in printability impairments. In this case, these local changes of the compressive stress occur at the fold of the blanket in the vicinity of the insertion point in the cylinder of the printing press particularly frequently, which is visible on the printed paper at the front tip and the rear end as pollution. As used in the present specification, these contaminants are referred to as "blanket scrapers" and resistance to these contaminants is also referred to as "blanket scratch resistance".

Titanium dioxide used for the primer layer may be in both rutile and anatase form. Incidentally, its production method is not limited to the sulfate method or the chloride method, which may be used singly or mixedly. Furthermore, from the viewpoints of dispersion stability and other functionalities, titanium dioxides having various surface treatments can be selectively used. For the surface treatment composition, alumina, silica, zinc oxide and zirconia are common. As commercially offered Titanium dioxide includes, for example, SR-1, R-650, R-5N, R-7E, R-3L, A-110, and A-190 from Sakai Chemical Industry AG, including Tipaque R-580, where R-930 where A -100, where A-220 and where CR-58 of Ishihara Sangyo AG, including Kronos KR-310, where KR-380, where KA-10 and where KA-20 of Titan Kogyo AG, including Titanix JR-301, where JR -600A, where JR-800 and where JR-701 from Tayca AG and ua Ti-Pure R-900 and where to call R-931 from Du Pont AG.

The average particle diameter of the titanium dioxide to be used in the invention should preferably be smaller than the average dry film thickness of the undercoat layer. Titanium dioxide usually occurs in the form of secondary and tertiary particles of aggregated primary particles. The average particle diameter of the titanium dioxide should preferably be adjusted accordingly, that in the with a dispersing agent such as. B polycarboxylic acid, fatty acid amine, sulfonic acid amide, ε-caprolactone, hydrostearic acid or polyesteramine admixed dispersion medium titanium dioxide is added and dispersed by means of a media mill such as ball mill, bead mill or sand mill, a pressure dispersing machine such as high pressure homogenizer or ultrahigh pressure homogenizer, a Ultraschalldispergiermaschine or Dünnschichtrotationsdispergiermaschine. The average titanium dioxide particle diameter in the undercoat layer should advantageously be 0.1 to 1.5 μm, with 0.3 to 1.0 μm being more advantageous. In this case, the average particle diameter of titanium dioxide can be determined by means of a particle size distribution meter according to the laser scattering method (eg LA920 from the manufacturer Horiba AG) in the form of a number-median diameter.

The titanium dioxide content in the primer layer of the present invention may be broad, but should preferably be 200 to 1000 wt% based on 100 parts by mass of the solid content of the binder resin contained in the undercoat layer, and 400 to 600 wt% is more preferable. If the titanium dioxide content is too low, it may happen that the water retention capacity is reduced or no effect on the scratch resistance becomes apparent. In an excessive use of titanium dioxide, it may happen that, for example, the stability of the coating composition decreases, the increase in bulk density due to irregular aggregation o. The like. The surface roughness is increased or the printing ability is reduced.

As the binder resin contained in the primer layer of the present invention, gelatin such as u. a. lime-treated gelatin, acid-treated gelatin and enzyme-treated gelatin, and water-soluble polymers such as e.g. a. Polysaccharide, polyvinyl alcohol and polyvinylpyrrolidone are used, wherein the use of gelatin is particularly advantageous.

As the crosslinking agent contained in the primer layer of the present invention, for example, u. a. Melamine resin, epoxy resin, polyisocyanate compound, aldehyde compound, silane compound, chrome alum and divinylsulfone are used with good suitability, wherein in gelatin as a binder resin, the particularly advantageous crosslinking agent is divinyl sulfone. The amount of addition of the crosslinking agent in the undercoat layer should preferably be 1 to 30% by weight based on the solid amount of said binder, with 2 to 15% by weight being more preferable. For the addition of the crosslinking agent, there are u. a. the possibility of adding in the preparation of the coating composition for the primer layer or the addition in the running process immediately before application; Any of these approaches can be used.

<water-resistant carrier>

As the waterproof carrier to be used for the thermosensitive lithographic printing plate of the present invention, u. a. Plastic film, resin-coated paper and waterproof paper are used. Specifically, plastic film can u. a. Polyolefin such as polyethylene and polypropylene, polyethersulfone, polyester, poly (meth) acrylate, polycarbonate, polyamide and polyvinyl chloride; coated or coated, resin-coated papers with these plastics on the surface; and with wet strength agents such as u. a. Melaminformaldehydharz, urea-formaldehyde resin and epoxidized polyamide resin waterproofed papers are used with good suitability.

Now, the plate-making method with the above-described thermosensitive lithographic printing plate according to the present invention will be explained. The thermosensitive lithographic printing plate according to the invention has thermosensitive imaging layers. When photothermal substance is contained in the imaging layers of the present invention in the thermosensitive lithographic printing plate, image formation can be performed, for example, by irradiation with a light containing infrared light between 760 nm and 1200 nm. It should preferably by a solid state laser or Semiconductor laser, the infrared beam emitted, the formation of the image sites done. In particular, the laser exposure allows direct image recording from the digital information on the computer. Further, in the thermosensitive lithographic printing plate of the present invention, by means of a thermal head or heating block, the imaging layers can be directly thermally imaged to form the image positions. The thermal head allows direct image recording from the digital information on the computer. The thermosensitive lithographic printing plate printed in this way according to the invention can then be used for printing, without the need for ablating the imaging layers as a result of the ablation or development in the printing press.

When using a thermal head, among others, a line printer with a thick-film or thin-film line head or a serial printer with a thin-film series head can be used. The energy density of the recording should preferably be 10 to 100 mJ / mm ² . Incidentally, for image output of relatively high quality, the image recording density of the head should be 300 dpi or more.

Moreover, in the thermosensitive lithographic printing plate of the present invention, any of the known surface treatment agents used in the conventional lithographic printing plates of good suitability can make the change to the ink accepting or improve the assumption. The printing process or lipophobicating agent, dampening solution or the like, which are used, can also be applied by generally known methods.

[Embodiments]

In the following, the invention will be explained with reference to exemplary embodiments. Incidentally, in the following explanations, "%" and "parts" refer to wt% or parts by mass unless otherwise specified.

(Embodiment 1)

On one side of a polyethylene-coated paper laminated on both sides, about 180 μm thick, were the coating compositions for the first layer (imaging layer (A)) and the second layer (imaging layer (B)), which in the following formulation are imaging layer application compound a according to Table 1 were simultaneously applied by the slide-hopper coating method at a wet application rate of 30 g / m ² for the 1st layer and 10 g / m ² for the 2nd layer, respectively, and then dried to prepare the imaging layers, thus rendering the thermosensitive lithographic Printing plates with the sample no. 1 to 13 were obtained. <Imaging layer application mass a> Water-soluble polymer compound: gelatin X kg (on solids) Thermoplastic substance: Carboxylated SBR resin: Lacster 7132C ^® (manufactured by DIC Ltd., aqueous dispersion with solids content 45%) Y kg (solids) Surfactant: Nikkol OTP-75 ^® (manufactured by Nikko Chemicals AG) 0.25 kg (on solids) Curing agent: 1,3-bis (vinylsulfonyl) -2-propanol 0.15 kg (on solids) Color former mixed slurry 2.1 kg (on solids) With water to a total of 50 kg: filled up.

The color former mixed slurry for the above-described imaging layer coating compound a was previously prepared in the following composition.

<Preparation of color former mixed slurry>

• Material a: 1,2-bis (3-methylphenoxy) ethane (Manufacturer: Sanko AG, KS-232)
• Material b: 4-hydroxy-4'-isopropoxydiphenylsulfone (Manufacturer: Nippon Soda AG, D-8)
• Material c: 3-dibutylamino-6-methyl-7-anilinofluoran (Manufacturer: Yamamoto Chemicals AG, ODB2)

The materials a, b and c were micro-dispersed individually in advance in a small DYNO-MILL (bead mill) with zirconia beads to a corresponding particle diameter, and each one adjusted to a solids concentration of 30% liquid dispersion a, b. or c made. To each 3 parts of the dispersions a and b, 1 part of the dispersion c was mixed at room temperature, whereby the color former mixed slurry was prepared. Sample ^no. 1st layer of the imaging layer (A) 2nd layer of imaging layer (B) Waterless polymer X (kg) Thermoplastic resin Y (kg) relationship Water-soluble polymer X (kg) Thermoplastic resin Y (kg) relationship 1 1.50 2.70 1.80 2.00 0.10 0.05 2 1.50 2.70 1.80 2.00 0.30 0.15 3 1.50 2.70 1.80 2.00 1.35 0.68 4 1.50 15.00 10.00 2.00 1.35 0.68 5 1.50 15.00 10.00 2.00 4.00 2.00 6 1.50 15.00 10.00 2.00 8.00 4.00 7 1.50 1.00 0.67 2.00 0.30 0.15 8th 1.50 2.00 1.33 2.00 0.30 0.15 9 1.50 27.00 18,00 2.00 1.35 0.68 10 1.50 33,00 22.00 2.00 1.35 0.68 11 1.50 2.70 1.80 2.00 3.00 1.50 12 1.50 2.70 1.80 2.00 2.00 1.00 13 2.00 1.35 0.68 1.50 2.70 1.80 * Ratio refers to the ratio (mass ratio) of the thermoplastic resin with respect to the water-soluble polymer compound.
(Heat Melting Resin (Y) / Water Soluble Polymer Compound (X))

For comparison, on one side of a laminated on both sides, about 180 microns thick polyethylene-coated paper, the coating composition prepared in the following formulation Bebilderungsschichtauftragmasse b applied by the slide-hopper coating method at a wet application rate of 60 g / m ² and then dried, making the thermosensitive lithographic printing plate with the sample no. 14 was obtained. <Imaging layer application mass b> Water-soluble polymer compound: gelatin 1.25 kg (on solids) Thermoplastic substance: Carboxylated SBR resin: Lacster ^® 7132C (manufactured by DIC Ltd., aqueous dispersion with solids content 45%) 1.8 kg (on solids) Surfactants: NIKKOI ^® OTP-75 (manufactured by Nikko Chemicals AG) 0.25 kg (on solids) Curing agent: 1,3-bis (vinylsulfonyl) -2-propanol 0.15 kg (on solids) Color former mixed slurry 2.1 kg (on solids) Filled with water to a total of 50 kg.

The thermosensitive lithographic printing plates, which were manufactured in this way were a direct thermal printer (manufactured by Toshiba Tec AG, Barcode Printer B-433 ^®: line thermal head 300 dpi) in the test print mode (print speed 2 inch / sec, applied energy 18.6 mJ / mm ² ) images were recorded, with which the printing plates were manufactured.

For printing in terms of printing life, the printing machine HAMADAH234C ^® (an offset printing machine brand manufacturer Hamada Printing Press AG) was used with the ink New Champion F-Gloss ink N (a brand of the manufacturer DIC AG) and the dampening solution in the form of a 12% aqueous solution of SLM- ^OD® (a fountain solution brand of the manufacturer: Mitsubishi Paper Mills AG), where before the start of printing, the printing area was completely wiped and moistened with the dampening solution, whereupon for evaluation under the forced conditions between the plate cylinder and the plate Substrate film of 0.1 mm placed and thus under increased compressive stress of the pressure was started. The number of prints at which defects in the image of the print occurred and no further printing was possible was evaluated according to the following criteria.

<Press Life>

• ⌾: 5,000 prints or more
• ⌾: 3,000 or more but less than 5,000 prints
• Δ: 1,000 or more but less than 3,000 prints
• x: Less than 1,000 prints

The results are shown in Table 2.

For pressure evaluation on from tone (water retention), the printing press Ryobi32000D ^® was (a trademark of the manufacturer Ryobi Imagics AG) with the ink New Champion Violet 68N ^® sodium in the form of a 2% aqueous (an ink mark of the manufacturer DIC AG) and the dampening solution Solution of SLM- ^OD® (a dampening solution brand of the manufacturer: Mitsubishi Paper Mills AG), wherein before the start of printing, the printing surface was completely wiped and moistened with the dampening solution and then the pressure was started. The number of prints in which the non-image areas of the print were soiled (toned) was evaluated according to the following criteria.

<Tone freedom (water holding capacity)>

• ⌾: 2,000 prints or more
• O: 1,500 or more but less than 2,000 prints
• Δ: 1,000 or more but less than 1,500 prints
• x: Less than 1,000 prints

The results are shown in Table 2. [Table 2] Sample No. Press life Tone freedom (water retention capacity) invention 1 O ⌾ invention 2 ⌾ ⌾ invention 3 ⌾ ⌾ invention 4 ⌾ ⌾ invention 5 ⌾ ⌾ invention 6 ⌾ O invention 7 O ⌾ invention 8th ⌾ ⌾ invention 9 ⌾ ⌾ invention 10 ⌾ O invention 11 ⌾ Δ invention 12 ⌾ ⌾ Comparative Examples 13 Δ x Comparative Examples 14 Δ x

As can be seen from the results shown in Table 2, it can be seen that by a higher ratio of the thermoplastic resin to the water-soluble polymer compound in the imaging layer (A) closer to the waterproof carrier than the corresponding ratio in the farthest from the waterproof carrier Bebilderungsschicht (B) good printing life and tone freedom (water retention) can be obtained.

(Embodiment 2)

*Verhältnis bezieht sich auf das Verhältnis (Massenverhältnis) des thermoplastischen Harzes bezogen auf die wasserlösliche Polymerverbindung.
(Bei Hitze schmelzendes Harz (Y)/Wasserlösliche Polymerverbindung (X)) [Tabelle 4] Probe Nr. Drucklebensdauer Tonfreiheit (Wasserhaltevermögen) Erfindung 15 O ⌾ Erfindung 16 ⌾ ⌾ Erfindung 17 ⌾ ⌾ Erfindung 18 O O Vergleichsbeispiele 14 Δ x On one side of a laminated on both sides, about 180 microns thick polyethylene-coated paper, the coating composition for the first layer (imaging layer (A)) prepared in the following formulation imaging layer coating composition c according to Table 3 by the slide-hopper coating process at a wet application rate of 20 g / m ² applied and then dried, also applied in the following formulation Bebilderungsschichtauftragmasse c prepared according to Table 3 coating material for the second layer (imaging layer (C)) by the slide-hopper coating method at a wet application rate of 20 g / m ² and then dried and finally applied in the following formulation Bebilderungsschichtauftragmasse c prepared according to Table 3 for the 3rd layer (imaging layer (B)) by the slide-hopper coating process at a wet application rate of 20 g / m ² and then dried for production of the Imaging layers, with which the thermosensitive lithographic printing plates with the sample no. 15 to 18 were obtained. The color former mixed slurry used was the same as in the above-described sample No.. 1. For comparison, the above-described thermosensitive lithographic printing plate having the sample no. 14 used. The thus-fabricated thermosensitive lithographic printing plates were used and evaluated as in Embodiment 1 for printing. The results are shown in Table 4. <Imaging layer application compound c> Water-soluble polymer compound: gelatin X kg (on solids) Thermoplastic substance: Carboxylated SBR resin: Lacster ^® 7132C (manufactured by DIC Ltd., aqueous dispersion with solids content 45%) Y kg (solids) Thermoplastic substance: Montansäureesterwachs: Hydrin ^® J-537 (manufacturer: Chukyo Yushi Ltd., aqueous dispersion with solids content 30%) 0.45 kg (on solids) Surfactants: Nikkol ^® OTP-75 (manufactured by Nikko Chemicals AG) 0.25 kg (on solids) Curing agent: 1,3-bis (vinylsulfonyl) -2-propanol 0.15 kg (on solids) Color former mixed slurry 2.1 kg (on solids) Filled with water to a total of 50 kg. [Table 3]

* Ratio refers to the ratio (mass ratio) of the thermoplastic resin with respect to the water-soluble polymer compound.
(Heat-melting resin (Y) / water-soluble polymer compound (X)) [Table 4] Sample No. Press life Tone freedom (water retention capacity) invention 15 O ⌾ invention 16 ⌾ ⌾ invention 17 ⌾ ⌾ invention 18 O O Comparative Examples 14 Δ x

As can be seen from the results shown in Table 4, even when 3 layers of imaging layers are formed, it is apparent from the higher ratio of the thermoplastic resin to the water-soluble polymer compound in the imaging layer (A) closer to the waterproof support than the corresponding ratio in the above Good printing life and tone freedom (water retention capacity) are obtained from the waterproof support furthest away from the imaging layer (B).

(Embodiment 3)

On one side of a laminated on both sides, about 180 microns thick polyethylene-coated paper, the coating compositions for the 1st layer (imaging layer (A)) and the 2nd layer (imaging layer (B)), in the following formulation imaging layer application mass d according to Table 5 were simultaneously applied by the slide-hopper coating method at a wet application rate of 30 g / m ² for the 1st layer and 10 g / m ² for the 2nd layer, respectively, and then dried to prepare the imaging layers, thus rendering the thermosensitive lithographic Printing plates with the sample no. 19 to 25 were obtained. The compound represented by general formulas (1) to (4), the color developer and the color former were previously individually in a small DYNO-MILL ^® (bead mill) microdispersed with zirconia beads at a solids concentration of 30% in each case used in the state of the liquid dispersion , <Imaged coating layer d> Water-soluble polymer compound: Gelatin: IK3000 ^® (Hesteller: Nippi AG) X kg (on solids) Thermoplastic substance: Carboxylated SBR resin: Lacster ^® 7132C (manufactured by DIC Ltd., aqueous dispersion with solids content 45%) 1.45 kg (on solids) Surfactants: NIKKOI ^® OTP-75 (manufactured by Nikko Chemicals AG) 0.3 kg (on solids) Curing agent: 1,3-bis (vinylsulfonyl) -2-propanol 0.15 kg (on solids) Compound according to the general formulas (1) to (4): 1,2-bis (3-methylphenoxy) ethane Y kg (solids) Color developer: 4-hydroxy-4'-isopropoxydiphenylsulfone (manufacturer: Nippon Soda AG) 1.00 kg (on solids) Color former: 3-dibutylamino-6-methyl-7-anilinofluoran (manufacturer: Yamamoto Chemicals AG) 0.30 kg (on solids) Heat fusible substance: Montansäureesterwachs: hydrin ^® J-537 (manufactured by Chukyo Yushi AG) 0.40 kg (on solids) Filled with water to a total of 40 kg. [Table 5] Sample No. 1st layer: lower layer of the imaging layer (A) 2nd layer: upper layer of imaging layer (B) Differences between the ratio of the 1st layer and the ratio of the 2nd layer Water-soluble polymer compound X (kg) Compound of the general formulas (1) to (4) Y (kg) Ratio (Y / X) Water-soluble polymer compound X (kg) Compound of the general formulas (1) to (4) Y (kg) Ratio (Y / X) 19 0.79 1.18 1.49 0.26 0.16 0.61 0.88 20 0.79 1.35 1.71 0.26 0.16 0.61 1.10 21 0.79 1.35 1.71 0.26 0.1 0.38 1.33 22 0.79 1.47 1.86 0.26 0 0.00 1.86 23 0.79 1.4 1.77 0.26 0.02 0.08 1.70 24 0.79 0.85 1.08 0.26 0.02 0.08 1.00 25 0.79 0.75 0.95 0.26 0.02 0.08 0.87 26 1.05 0.95 0.90 - - - - 27 1.05 0 0.00

For comparison, the coating composition prepared according to Table 5 was further coated by the slide-hopper coating method at a wet application rate of 40 g / m ² and then dried to obtain the comparative samples (the thermosensitive lithographic printing plates having Sample Nos. 26 and 27) were.

The thermosensitive lithographic printing plates, which were manufactured in this way were a direct thermal printer (manufactured by Toshiba Tec AG, Barcode Printer B-433 ^®: line thermal head 300 dpi) in the test print mode (print speed 2 inch / sec, applied energy 18.6 mJ / mm ² ) images were recorded, with which the printing plates were manufactured.

In order to evaluate the improvement in head deposition, 50 plates were prepared in sequence with diagonally printed one-dot images to visually inspect the 1st and 50th plates prepared according to the following criteria; the results are given in Table 6.

<Head deposit-improvement>

• o: No difference in image quality between the 1st and the 50th plates.
• x: difference in picture quality between the 1st and the 50th plate can be seen.

<Print>

With respect to the press life, under the above plate-making conditions, the plates were prepared with the print evaluation images which served as samples for printing in the printing test. When the printing press was HAMADA DU342C ^® (an offset printing machine the manufacturer Hamada Printing Press AG) with the ink New Champion F Gloss Ink ^® 85N (manufactured by DIC Ltd.) and the fountain solution in the form of a 3% aqueous solution of SLM OD30 ^® (a fountain solution to the manufacturer Mitsubishi Paper Mills Ltd.), where completely wiped before the start of printing, the printing surface with a 10% aqueous solution of SLM-OD30 ^® (a fountain solution to the manufacturer Mitsubishi Paper Mills Ltd.) and wetted and then the print was started. In order to evaluate the improvement in sticking appearance, it was determined whether there were white stripes appearing in the black solid areas of the prints perpendicular to the printing direction in plate making and evaluated according to the following criteria. In addition, to evaluate the press life, the number of prints at which defects in the image of the print occurred and no further printing was possible was evaluated according to the following criteria.

<Sticking appearance enhancement>

• O: No white stripe recognizable.
• x: white stripes recognizable.

<Press Life>

• ⌾: 5,000 prints or more
• O: 3,000 or more but less than 5,000 prints
• Δ: 1,000 or more but less than 3,000 prints
• x: Less than 1,000 prints

The results are shown in Table 6.

With respect to the tonelessness (water holding capacity), under the above plate-making conditions, plates were prepared with the print evaluation images which served as samples for printing in the printing test. When the printing press was Ryobi3200CD ^® (manufacturer: Ryobi Imagics AG) with the ink New Champion F Gloss Purple 68N ^® (manufactured by DIC Ltd.) and the fountain solution in the form of a 2% aqueous solution of SLM-OD ^® (a dampening of the manufacturer Mitsubishi Paper Mills Ltd.) to give completely wiped before the start of printing, the printing surface with a 20% aqueous solution of SLM-OD30 ^® (a fountain solution to the manufacturer Mitsubishi Paper Mills Ltd.) and wetted and then started the pressure , The number of prints in which the non-image areas of the print were soiled (toned) was evaluated according to the following criteria.

<Tone freedom (water holding capacity)>

• ⌾: 2,000 prints or more
• O: 1,500 or more but less than 2,000 prints
• Δ: 1,000 or more but less than 1,500 prints
• x: Less than 1,000 prints

The results are shown in Table 6. [Table 6] Sample No. Head Deposit improvement Sticking Specter improvement Tone freedom (water retention capacity) Press life invention 19 O O Δ O invention 20 O O Δ ⌾ invention 21 O O ⌾ ⌾ invention 22 O O ⌾ ⌾ invention 23 O O ⌾ ⌾ invention 24 O O ⌾ O invention 25 O ⌾ ⌾ Δ Comparative Examples 26 x O x Δ Comparative Examples 27 O x x x

As can be seen from the results shown in Table 6, it can be seen that by a higher ratio of the compound represented by the general formulas (1) to (4) with respect to the water-soluble polymer compound in the imaging layer (A) closer to the waterproof support than that shown in FIG corresponding ratio in the waterproofing carrier furthest removed imaging layer (B) thermosensitive lithographic printing plates are obtained, which in addition to high pressure life and Tonfreiheit (water retention) improvements in printing defects due to the head deposition and image disturbance by the sticking phenomenon with them.

(Embodiment 4)

Except for the compound represented by the general formulas (1) to (4) in the embodiment 3, which was replaced by 2-benzyloxynaphthalene, the tests were carried out in the same manner and the results were the same as in the embodiment 3.

(Embodiment 5)

Except for the compound represented by the general formulas (1) to (4) in Embodiment 3, which was replaced by oxalic acid bis (p-methylbenzyl), the tests were carried out in the same manner and the same results as in the embodiment were obtained third

(Embodiment 6)

Except for the compound represented by the general formulas (1) to (4) in Embodiment 3, which was replaced by 1,2-bisphenoxymethylbenzene, the tests were carried out in the same manner and the results were the same as in the embodiment 3.

(Embodiment 7)

With regard to the Bebilderungsschichtauftragmasse the Bebilderungsschichtauftragmasse of the embodiment 3 was 0.25 kg of solid carbon black: added, but otherwise in the same manner, the samples and comparative samples were manufactured: SD9020 ^® (DIC AG manufacturer). With a semiconductor laser (wavelength 830 nm, power 500 mw) took place in a resolution of 1200 dpi, the exposure, and the same pressure ratings as in the embodiment 3 were performed, resulting in the same printing results as in the embodiment 3.

(Embodiment 8)

[Tabelle 8] Probe Nr. KopfablagerungVerbesserung Sticking-Erscheinung-Verbesserung Tonfreiheit (Wasserhaltevermögen Drucklebensdauer Erfindung 28 O O ⌾ O Erfindung 29 O O ⌾ ⌾ Erfindung 30 O O ⌾ ⌾ Erfindung 31 O O O ⌾ Vergleichsbeispiele 26 x 0 x Δ Vergleichsbeispiele 27 0 x x x On one side of a laminated on both sides, about 180 microns thick polyethylene-coated paper, the coating composition for the first layer (imaging layer (A)) prepared in the above described formulation imaging layer d according to Table 7 by the slide-hopper coating method at a wet application rate of 20 g / m ² applied and then dried, also applied in the formulation Bebilderungsschichtauftragmasse d prepared according to Table 7 for the second layer (imaging layer (C)) by the slide-hopper coating method at a wet application rate of 10 g / m ² and then dried and finally the applied in the formulation Bebilderungsschichtauftragmasse d prepared according to Table 7 for the 3rd layer (imaging layer (B)) by the slide-hopper coating process at a wet application rate of 10 g / m ² and then applied dried to prepare the imaging layers, whereby the thermosensitive lithographic printing plates with the sample no. 28 to 31 were obtained. The compound according to the general formulas (1) to (4), the color developer and the color former in advance separately as in Embodiment 3 by means of a small DYNO-MILL ^® (bead mill) microdispersed with zirconia beads at a solids concentration of 30% and in each case in the state the liquid dispersion used. Further, for comparison, the above-described thermosensitive lithographic printing plates having the sample no. 26 and 27 used. The thus-fabricated thermosensitive lithographic printing plates were evaluated as in Embodiment 3. The results are shown in Table 8. [Table 7]

[Table 8] Sample No. Head deposition improvement Sticking appearance improvement Tone freedom (water retention capacity Press life invention 28 O O ⌾ O invention 29 O O ⌾ ⌾ invention 30 O O ⌾ ⌾ invention 31 O O O ⌾ Comparative Examples 26 x 0 x Δ Comparative Examples 27 0 x x x

As can be seen from the results shown in Table 8, it also shows that 3 layers of imaging layers formed by a higher ratio of the compound represented by the general formulas (1) to (4) relative to the water-soluble polymer compound in the closer to the waterproof carrier the imaging layer (A) as the corresponding ratio in the waterproofing carrier farthest imaging layer (B) thermosensitive lithographic printing plates are obtained, which in addition to high printing life and Tonfreiheit (water retention) improvements in printing defects due to the head deposit and image disturbance by the sticking Appearance.

(Embodiment 9)

On one side of a laminated on both sides, about 180 microns thick polyethylene-coated paper, the application rates for the primer layer, imaging layer (A) and Bebilderungsschicht (B) described below by the slide-hopper coating process at a wet application rate of 15 g / m ² for the Primer coat application mass a, 30 g / m ² for the imaging layer (A) application mass e or 10 g / m ² for the imaging layer (B) application mass f from the side of the support in the order primer layer, imaging layer (A) and Bebilderungsschicht (B) (the top layer) applied in three layers simultaneously. <Primer layer coating compound a> Binder resin: gelatin 0.8 parts Titanium dioxide: TISR1 ^® (manufactured by Sakai Chemical AG, rutile form, alumina treated) 4.0 parts Acrylic acid copolymer metal salt (dispersant, 10% solution) 0.2 parts Surfactant (0.5% solution) 0.05 parts Crosslinking agent: divinyl sulfone (5% solution) 1.0 parts Filled with water to a total of 15 parts. <Imaging Layer (A) Apply Mass e> Water-soluble polymer compound: gelatin 0.7 parts Water-soluble polymer compound: polyvinyl alcohol 0.07 parts Thermoplastic substance: Carboxylated SBR resin: Lacster ^® 7132C (manufactured by DIC Ltd., aqueous dispersion with 45% solids content, anionic, Tg: 60 ° C) 3.0 parts Surfactant (0.5% solution) 0.4 parts Hardener: divinyl sulfone hardener (5% solution) 2.0 parts Color former mixed slurry 7.0 parts Filled with water to a total of 30 parts. <Imaging Layer (B) application mass f> Water-soluble polymer compound: gelatin 0.3 parts Thermoplastic substance: Carboxylated SBR resin: Lacster ^® 7132C (manufactured by DIC Ltd., aqueous dispersion with 45% solids content, anionic, Tg: 60 ° C) 0.6 parts Surfactant (0.5% solution) 0.2 parts Montanic acid ester wax emulsion (heat-melting resin: n-octacosanoic acid (carbon number 28), solid content 30%) 0.1 parts Curing Agent: divinyl sulfone curing agent (5% solution) 0.8 parts Color former mixed slurry 0.3 parts Made up with water to a total of 10 parts.

The above-described primer layer coating composition a was prepared by adding titanium dioxide into water added with the dispersant and high-speed microdispersion by means of a Homo-Mixer for 30 minutes, followed by sequentially mixing gelatin, the surfactant and divinylsulfone. In this case, a part of this primer layer coating material was removed, diluted and with a particle size distribution meter according to the laser scattering method (manufacturer: Horiba Ltd., LA920 ^®) the average particle diameter of titanium dioxide measured, from the value of 0.7 microns resulted.

The color former mixed slurries for the above-described imaging layer (A) coating composition e and imaging layer (B) application composition f were previously prepared by the following preparation method.

<Preparation of color former mixed slurry>

• Material a: 1,2-bis (3-methylphenoxy) ethane (Manufacturer: Sanko AG, KS-232)
• Material b: 4-hydroxy-4'-isopropoxydiphenylsulfone (Manufacturer: Nippon Soda AG, D-8)
• Material c: 3-dibutylamino-6-methyl-7-anilinofluoran (Manufacturer: Yamamoto Chemicals AG, ODB2)

The materials above a, b and c were previously individually in a DYNO-MILL ^® (bead mill) with zirconia beads microdispersed up to an appropriate particle diameter, and in each case an adjusted to a solids concentration of 30% liquid dispersion of a, b. or c made. To each 3 parts of the dispersions a and b, 1 part of the dispersion c was mixed at room temperature, whereby the color former mixed slurry was prepared.

After the simultaneous three-coat application at the above-mentioned wet application amounts of the application film was immediately gelled with cold wind of 3 ° C and then dried with warm wind of 30 ° C. By the 7-day heating by means of an air conditioner set to 40 ° C / 40% humidity after drying, the thermosensitive lithographic printing plate with the sample no. 32 received. A sectional area of the obtained thermosensitive lithographic printing plate was examined by a scanning electron microscope, and the average of 10 arbitrary locations was found to be the average dry film thickness of the undercoat layer; the result was 1.5 μm. The mean dry film thickness of the imaging layers including the A and B layers was about 5.0 μm.

Except for the in the production of the thermosensitive lithographic printing plate with the sample no. 32 undercoat layer coating composition used in a given titanium dioxide TISR1 which ^® by Tipaque R-580 (manufactured by Ishihara Sangyo Ltd., rutile form alumina-treated) was replaced, in the same manner as the heat-sensitive lithographic printing plate with the sample number. 32, the thermosensitive lithographic printing plate with the sample no. 33 received. The mean dry film thickness of the undercoat layer was 1.5 μm, while the average particle diameter of titanium dioxide was 0.9 μm.

Except for the in the production of the thermosensitive lithographic printing plate with the sample no. 33 undercoat layer coating composition used in a given titanium dioxide (Tipaque R-580 ^®), the addition amount thereof was changed from 4 parts to 3 parts, as well as the Gelatinmenge, which was also changed from 0.8 parts to 0.6 parts, was obtained in the same manner as the thermosensitive lithographic printing plate with the sample no. 33, the thermosensitive lithographic printing plate with the sample no. 34 received. The average dry film thickness of the undercoat layer was 1.2 μm, while the average particle diameter of titanium dioxide was 0.9 μm.

The thermosensitive lithographic printing plates having the sample No. manufactured as described above. 32 to 34 were measured with a CTP thermal digital printer (manufactured by Mitsubishi Paper Mills Ltd., thermal Digiplater TDP-459 ^®: 1200 dpi / 120 lpi) imaged (energy density of the recording 70 to 100 mJ / mm ^2, electric capacity 330 W), thus the printing plates were made.

The printing plates produced in this way were mounted in the offset printing machine without further treatment and subjected to pressure surface etching with the following dampening solution, whereupon the printing took place. <Dampening solution> citric acid 15 g Phosphoric acid (85%) 5 g propylene glycol 100 g Colloidal Silica (20% Fluid) 80 g Filled with water to a total of 2 liters.

For printing, the offset printing machine (manufacturer: Heidelberg, QM46 ^® ) with the printing ink Fusion G ink N of the manufacturer DIC AG and the dampening solution described above was used.

<Image quality evaluation>

• O: Gar keine Fehlstellen in 1Q-Schriften, scharfe Reproduktion.
• Δ: Zum Teil fehlende Stellen in 1Q-Schriften, leicht mangelnde Schärfe.
• x: Großteil der 1Q-Schriften fehlt.

The reproduction of fonts from thin lines in size 1Q (Quarter) was checked with a 25x magnifying glass and evaluated according to the following criteria. These results are shown in Table 9.

• O: No flaws in 1Q fonts, sharp reproduction.
• Δ: Partly missing parts in 1Q fonts, slightly lacking in sharpness.
• x: Most of the 1Q fonts are missing.

<Press Life>

• O: 3.000 Drucke oder mehr
• Δ: 2.000 oder mehr aber weniger als 3.000 Drucke
• x: Weniger als 2.000 Drucke

Until the reproduction of thin-line fonts in size 1Q (quarter) on the printed paper was no longer possible, the print was repeated and evaluated according to the following criteria. These results are shown in Table 9.

• O: 3,000 prints or more
• Δ: 2,000 or more but less than 3,000 prints
• x: Less than 2,000 prints

<Blanket scratch resistance>

• O: Überhaupt keine örtliche Teilverschmutzungen oder ungleichmäßige Verschmutzungen erkennbar.
• Δ: Geringfügige örtliche Teilverschmutzungen oder ungleichmäßige Verschmutzungen erkennbar.
• x: Deutlich örtliche Teilverschmutzungen oder ungleichmäßige Verschmutzungen erkennbar.

The normal plate-blanket pressure during printing was increased approximately twice and thus the pressure was carried out; at 500th printing, the front and back of the printed paper were inspected for particulate contamination and rated according to the following criteria. These results are shown in Table 9.

• O: No local partial dirt or uneven contamination recognizable.
• Δ: Minor local soil or uneven soil can be detected.
• x: Significant local partial dirt or uneven contamination visible.

<Resistance to scratch marks>

By scratching Intensity TESTER: HEIDON-18 ^® from the manufacturer HEIDON the obtained heat-sensitive lithographic printing plates were prepared by the 60-second-ended immersion in 23 ° C-strength water under the conditions-sapphire needle of 0.2 mm, scratch speed is 10 mm / sec. - evaluated, wherein the assessment was made in accordance with the load [g], which resulted in scratch marks on the surface of the printing plate. These results are shown in Table 9. [Table 9] ^Sample No. picture quality Press life Blanket scratch resistance Strength against scratch marks annotation 32 O O O 250 to 300 invention 33 O O O 250 to 300 invention 34 O O O 200 to 250 invention

As apparent from the results shown in Table 9, it is found that by forming a primer layer containing titanium dioxide whose average particle diameter is smaller than the average dry film thickness of the undercoat layer, at least binder resin and crosslinking agent, between the closer to the waterproof carrier located imaging layer (A) and the waterproof carrier thermosensitive lithographic printing plates are obtained, the scratch resistance is improved, without affecting the image quality or the press life.

(Embodiment 10)

On one side of a two-sided laminated, about 180 microns thick polyethylene resin coated paper, the primer layer coating composition b, the imaging layer (A) application mass g and the imaging layer (B) application mass h in the following composition by the slide-hopper coating method of the side of the support in the order of primer layer, imaging layer (A) and imaging layer (B) (the uppermost layer) applied simultaneously in three layers. In this case, the amount of wet application in the primer coat application compound was set to 15 g / m ² , in the imaging layer (A) application composition g to 30 g / m ² and in the imaging layer (B) application composition h to 10 g / m ² . <Primer coat compound b> Binder resin: gelatin (bovine bone, alkali-treated, decalcified) 0.8 parts Titanium dioxide: TISR1 ^® converted to solid amount (manufactured by Sakai Chemical AG, rutile, primary particle diameter = 0.3 micron, alumina-treated) 4.0 parts Pigment dispersant (acrylic acid copolymer metal salt, 10% solution) 0.2 parts Surfactant (ethylhexyl sulfosuccinate, 0.5% solution) 0.05 parts Crosslinking agent: divinyl sulfone (5% solution) 2.0 parts Filled with water to a total of 15 parts. <Imaging Layer (A) Apply Mass g> Water-soluble polymer compound: gelatin (bovine bone, alkali-treated, decalcified) 0.8 parts Water-soluble polymer compound: Polyvinyl alcohol: PVA505 ^® (manufacturer: Kuraray Ltd., saponification = 73.5 mol%, polymerization degree 500) 0.07 parts Thermoplastic substance: Carboxylated SBR resin: Lacster ^® 7132C (manufactured by DIC Ltd., aqueous dispersion with 45% solids content, anionic, Tg: 60 ° C) 3.0 parts Color developer mixed slurry 8.0 parts Color former: (3-dibutylamino-6-methyl-7-anilinofluoran, 30% slurry) 0.7 parts Surfactant (ethylhexyl sulfosuccinate, 0.5% solution) 0.4 parts Hardener: divinyl sulfone hardener (5% solution) 2.0 parts Filled with water to a total of 30 parts. Imaging Layer (B) application mass h> Water-soluble polymer compound: gelatin (bovine bone, alkali-treated, decalcified) 0.4 parts Water-soluble polymer compound: Water-soluble polysaccharide: pullulan ^® (manufacturer: Hayashiharashoji AG, a food additive) 0.01 parts Thermoplastic substance: Carboxylated SBR resin: Lacster ^® 7132C (manufactured by DIC Ltd., aqueous dispersion with 45% solids content, anionic, Tg: 60 ° C) 3.0 parts Bariumsulfataufschlämmung: Bariace ^® B-35, converted to solid amount (manufactured by Sakai Chemical Industry Ltd., average particle diameter = 0.3 micron) 0.03 parts Pigment dispersant (acrylic acid copolymer metal salt, 10% solution) 0.002 parts Color former: (3-dibutylamino-6-methyl-7-anilinofluoran, 30% slurry) 0.3 parts Heat-melting substance: Aqueous wax: (n-octacosanoic acid (carbon number 28), solid content 30%) 0.3 parts Surfactant (ethylhexyl sulfosuccinate, 0.5% solution) 0.2 parts Hardener: divinyl sulfone hardener (5% solution) 1.0 parts Made up with water to a total of 10 parts.

In the production of the titania slurry for the above-described primer layer coating compound b and the barium sulfate slurry for the imaging layer (A) coating composition g, acrylic acid copolymer metal salt is used as the pigment dispersant in both cases. Their production can be carried out by adding titanium dioxide or barium sulfate gradually in water mixed with the pigment dispersant with constant stirring and high-speed microdispersion by means of a homo-mixer for 30 minutes. The slurries were made immediately prior to preparation of the application masses.

Further, the color developer mixed slurry for the above-described imaging layer (A) coating composition g was previously prepared and prepared from the following compositional chemicals.

<Color Chemical Compound Slurry> Composition Chemicals>

• Material a: KS-232® (Manufacturer: Sanko AG, sensitizer, 1,2-bis (3-methylphenoxy) ethane)
• Material b: D- ^8® (manufacturer: Nippon Soda AG, color developer, 4-hydroxy-4'-isopropoxydiphenylsulfone)
• Material c: Polymaron ^® 1318 (manufacturer: Arakawa Chemical Industries AG, dispersing agents, anionic styrene resin, 15% aqueous solution)

In offset with 0.7 parts of said material, c water the materials a and b, whereby the color developer were mixed 1 part each, and then to a particle diameter corresponding micro-dispersed in a small DYNO-MILL ^® (bead mill) with zirconia beads under constant agitation, Mixed slurry was obtained. The materials a, b and c were adjusted so that their total solids concentration is approx. 35%.

In the case of other chemicals, apart from water dilution, no special adjustment was made except for the hydrophilic polymers such as gelatin, polyvinyl alcohol and finally water-soluble ones Polysaccharides which were dissolved in water with heating. However, care was taken in the color developer mixed slurry described above from the preparation phase and the color former throughout the processes of its handling that the temperature did not exceed 45 ° C.

After the simultaneous three-coat application at the above-mentioned wet application rates, the application film was immediately gelled with cold wind of 1 to 3 ° C and then dried with set at 30 ° C warm wind. By the 7-day heating by means of an air conditioner set to 40 ° C / 40% humidity after drying, the thermosensitive lithographic printing plate with the sample no. 35 received.

Except for the in the production of the thermosensitive lithographic printing plate with the sample no. Barium sulfate containing Imaging Layer (B) load h used, which was replaced with zinc oxide (manufactured by Sakai Chemical Industry AG, microfine zinc oxide, average particle diameter = 0.29 μm), was treated with the same as the thermosensitive lithographic printing plate sample no. 35 the thermosensitive lithographic printing plate with the sample no. 36 received.

Except for in the in the manufacture of the thermosensitive lithographic printing plate with the sample no. In the same manner as the thermosensitive lithographic printing plate having the sample No. used, the barium sulfate slurry containing the amount of the image-forming layer (B) h used was changed from 0.03 part to 0.06 part. 35 the thermosensitive lithographic printing plate with the sample no. 37 received.

Except for in the in the manufacture of the thermosensitive lithographic printing plate with the sample no. In the same manner as the thermosensitive lithographic printing plate having the Sample No. used, the barium sulfate slurry containing Imaging Layer (B) coating composition h changed from 0.03 part to 0.08 part was used. 35 the thermosensitive lithographic printing plate with the sample no. 38 received.

Except for in the in the manufacture of the thermosensitive lithographic printing plate with the sample no. In the same manner as the thermosensitive lithographic printing plate having the sample No. used, the barium sulfate slurry containing the amount of the image-forming layer (B) h used was changed from 0.03 part to 0.0135 part. 35 the thermosensitive lithographic printing plate with the sample no. 39 received.

The thermosensitive lithographic printing plates having the sample No. manufactured as described above. 35 to 39 were measured with a CTP thermal digital printer (manufactured by Mitsubishi Paper Mills Ltd., thermal Digiplater TDP-459 ^®: 1200 dpi / 120 lpi) imaged (energy density of the recording 70 to 100 mJ / mm ^2, electric capacity 330 W), thus the printing plates were made. With these printing plates, printability was evaluated by the following method.

<Press Life>

When the printing press, the offset sheet printing press Heidelberg QM46 ^® was used with the printing ink Fusion G ink N ^® manufacturer Dainippon Ink and Chemicals AG and the fountain solution diluted in the form of a 10% solution of SLM-OD of the manufacturer Mitsubishi Paper Mills AG, whereby when the etching solution was the same fountain solution as it was used and the printing was done. To evaluate the printing life of the printed paper at the start of the printed paper at 5,000. Pressure, with the rates of reduction of the 20% and 50% halftone dots checked with a 25x magnifying glass and evaluated according to the following criteria. These results are shown in Table 10.
⌾: Hardly any changes at both 20% and 50% halftone dots
O: No changes at 50% halftone dots, but 20% halftone dots show a decrease
Δ: decrease visible at both 20% and 50% halftone dots
x: 50% or more decrease visible at 20% halftone dots
xx: At 20% halftone dots, 90% or more decrease visible

<Tone freedom (water holding capacity)>

When the printing press, the offset sheet printing press Heidelberg QM46 has also been used with the printing ink Fusion G Ink S ^® manufacturer Dainippon Ink and Chemicals AG and the fountain solution diluted in the form of a 0.5% solution of Astromark III ^® manufacturer Nikken Chemical Laboratory AG , wherein without etching the pressure was started. To evaluate the tonal freedom, the printed paper was evaluated according to the following criteria at 2,000 times after the start of printing. These results are shown in Table 10.
⌾: From 1 to 2,000. Pressure no toning occurred
O: From the 1st to the 1500th. Pressure no toning occurred
Δ: From the 1st to the 1,000th. Pressure no toning occurred
x: contamination at print startup (up to a maximum of 5 prints) or under 1,000 print toning occurred
xx: contamination at print start (from 6 prints) occurred [Table 10] Sample No. Press life Tonfreihei (water retention capacity) annotation 35 ⌾ ⌾ invention 36 ⌾ ⌾ invention 37 ⌾ ⌾ invention 38 O ⌾ invention 39 O O invention

As can be seen from the results shown in Table 10, it is found that by containing the zinc oxide or barium sulfate most distant from the waterproof support (B), thermosensitive lithographic printing plates are obtained in which the press life and tonelessness (water retention) are obtained. balanced are improved.

Claims (10)

A thermosensitive lithographic printing plate having on a waterproof support at least 2 layers of imaging layers containing a water-soluble polymer compound (s), a curing agent and thermoplastic resin (s), and with respect to those of the water-resistant one Carrier farthest imaging layer (B) and an imaging layer (A) closer to the waterproof carrier than the imaging layer (B) satisfies the following requirement i) and / or ii). i) The ratio of the thermoplastic resin (s) with respect to the water-soluble polymer compound (s) in the image-forming layer (A) is higher than the ratio of the thermoplastic resin (s) with respect to the water-soluble polymer compound (en) in the imaging layer (B). ii) The ratio of at least one compound to be selected from the compounds represented by the following general formulas (1) to (4) based on the water-soluble polymer compound (s) in the image-forming layer (A) is higher than the ratio of at least one of compound to be selected from the compounds represented by the following general formulas (1) to (4), based on the water-soluble polymer compound (s) in the image-forming layer (B). [Chemical Formula 1]

(wherein X _{1 represents} -O- or -COO-, R ₁ , R ₂ and R ₃ are each independently a hydrogen atom, an alkyl group or aryl group represent- or R ₁ , R ₂ and R ₃ connected together form an aromatic ring R ₄ , R ₅ and R ₆ independently of one another each represent a hydrogen atom, an alkyl group or an aryl group; or R ₄ , R ₅ and R ₆ together form an aromatic ring, and n represents an integer from 1 to 10.) [Chemical formula 2]

(wherein R _{7 represents} an alkyl group, aryl group, alkylcarbonyl group, arylcarbonyl group, alkylsulfonyl group or arylsulfonyl group, and the naphthalene ring according to the general formula (2) may have further substituents.) [Chemical Formula 3]

(wherein R ₈ and R ₉ each independently represents a hydrogen atom, halogen atom, an alkyl group having a carbon number of 1 to 4 or an alkoxy group having a carbon number of 1 to 4, X represents a single bond or n represents an integer of 1 to 4). [Chemical formula 4]

(wherein R ₁₀ , R ₁₀ , R ₁₁ and R ₁₁ each independently represent a hydrogen atom, halogen atom, an alkyl group, aryl group, alkoxy group, alkylcarbonyl group, arylcarbonyl group, alkoxycarbonyl group or aryloxy group.) A thermosensitive lithographic printing plate according to claim 1, wherein the difference between the ratio of the thermoplastic resin (s) with respect to the water-soluble polymer compound (s) in said imaging layer (A) and the ratio of the thermoplastic resin (s ) based on the water-soluble polymer compound (s) in said imaging layer (B) is 0.5 or more. A thermosensitive lithographic printing plate according to claim 1 or 2, wherein the ratio of the thermoplastic resin (s) relative to the water-soluble polymer compound (s) in said imaging layer (A) is 1 to 20 and the ratio of the thermoplastic resin (s) Resins (s) based on the water-soluble polymer compound (s) in said imaging layer (B) is 0.1 to 3. A thermosensitive lithographic printing plate according to claim 1, wherein the ratio of at least one compound to be selected from the compounds represented by the general formulas (I) to (4) relative to the water-soluble polymer compound (s) in said imaging layer (B) is 0, 5 or less. A thermosensitive lithographic printing plate according to claim 1 or 4, wherein the difference between the ratio of at least one compound to be selected from the compounds represented by the general formulas (1) to (4) relative to the water-soluble polymer compound (s) in said imaging layer (A) and the ratio of at least one compound to be selected from the compounds represented by the general formulas (1) to (4) relative to the water-soluble polymer compound (s) in said image-forming layer (B) is 1.0 or more. Thermosensitive lithographic printing plate according to one of claims 1 to 5, which satisfies said conditions i) and ii). A thermosensitive lithographic printing plate according to any one of claims 1 to 6, which has, between said imaging layer (A) and the waterproof support, a primer layer containing titanium dioxide whose average particle diameter is smaller than the average dry film thickness of the primer layer, at least binder resin and crosslinking agent. Thermosensitive lithographic printing plate according to one of claims 1 to 7, characterized in that said imaging layer (B) contains zinc oxide or barium sulfate. A thermosensitive lithographic printing plate according to any one of claims 1 to 8, wherein the imaging layers contain from 5 to 30% by weight of hardener based on the amount of solids of the water-soluble polymer compound (s) contained in the entire imaging layers. A printing method of the thermosensitive lithographic printing plate, wherein the thermosensitive lithographic printing plate according to any one of claims 1 to 9 is printed and then, without removing the Bebilderungsschichten, the printing takes place.