JP2002370439A - Lithographic printing method with single-fluid ink - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a printing method, in which a non-ablative process-less image forming material is employed so as to produce a lithographic printing plate giving a high quality print. SOLUTION: Disclosed is a lithographic printing method including the following steps: a step for preparing an image forming material including a support and an image-recording layer or an image-recording surface under the condition that the layer or the surface can not be ablated by a single-fluid ink including ink phase and polar phase; a step for exposing the image forming material by means of heat or light true to the image so as to change-over the affinity to the ink or the ink-repellent fluid of the image-recording layer or surface and consequently making a printing master including a lithographic printing image consisting of a non-exposed region having the affinity on either one of the ink phase and the polar phase and an exposed region having the affinity on the other phase between the ink phase and the polar phase; and a step for supplying the single-fluid ink to the printing master for executing printing. The exposed image-recording layer, which normally emerges the inferior specialization of the hydrophilicity or lipophilicity between the exposed region and the non-exposed region, gives a high quality printing copy in the combination with the single-fluid ink.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

FIELD OF THE INVENTION The present invention exposes an image-forming layer, including a switchable image-recording layer, image-wise, and then supplies a single-fluid ink to the exposed image-recording layer. Lithographic printing method.

[0002]

BACKGROUND OF THE INVENTION Lithographic printing presses use a so-called printing master, such as a printing plate, mounted on a cylinder of the printing press. The master has a lithographic image on its surface, and a print is obtained by applying ink to the image and then transferring the ink from the master onto a receiving material, typically paper. In the case of normal (so-called "wet") lithographic printing, inks and aqueous dampeners (aqueo)
us foundation solution (also called dampening liquid)
Is provided in a lithographic image consisting of lipophilic (or hydrophobic, ie, ink-receptive, water-repellent) areas and hydrophilic (or oleophobic, ie, water-receptive, ink-repellent) areas. . In the case of so-called driographic printing, the lithographic image consists of ink-acceptable and ink-abhesive (ink-repellent) areas, during which only ink is supplied to the master. Is done.

[0003] Print masters are generally known as the so-called computer-to-film method.
In this method, various pre-press steps such as typeface selection, scanning, color separation, screening, trapping, layout and imposition are performed digitally, each color separation being an image-setter. And transferred to graphic arts film. After processing, the film can be used as a mask for exposing the image forming material, called the plate precursor, and after processing the plate, a printing plate is obtained that can be used as a master.

In recent years, so-called direct printing plates (comp)
Uter-to-plate methods have gained much interest. Direct printing plate (direct-to-plat
This method, also called e) method, bypasses the production of the film, since the digital document is transferred directly to the plate precursor by a so-called plate-setter. A special type of direct printing method involves exposing the plate precursor while mounted on a plate cylinder of a printing press by an image-setter incorporated in the printing press. This method is often referred to as "computer-to-pres
s) "and printing presses with an integrated plate-setter are sometimes referred to as digital printing presses. For an overview of digital printing presses, see Proceedings of
the Imaging Science & Tec
hnology's 1997 International
nal Conference on Digital
Printing Technologies (No
n-Impact Printing 13). The direct printing method is described in, for example, EP-A 770.
495, EP-A 770 496, WO 94001
280, EP-A 580394 and EP-A 774
364. In most direct printing methods, so-called thermal or heat mode materials,
That is, a plate precursor or an on-press coatable composition containing a compound that converts absorbed light into heat is used. The heat generated upon image-wise exposure initiates a (physical-) chemical process, such as ablation, polymerization, insolubilization by polymer cross-linking, decomposition or particle coagulation of the thermoplastic polymer latex, and optional processing. Later, a lithographic image is obtained.

[0005] Typical plate materials used in direct printing processes are based on ablation. The problem with ablative plates is that
The generation of debris that is difficult to remove and can disrupt the printing process or contaminate the exposed optics of the integrated image-setter. Other methods require wet processing with chemicals, which can damage or contaminate the electronics and optics of the integrated image-setter and other equipment of the printing press. Therefore, direct printing usually requires the use of a plate material that is not ablative and does not require wet processing. Such non-absorptive process
A known example of a "less" plate material is a so-called "switchable" image-recording layer, i.e., its affinity for ink or ink-ink-repellent fluid when exposed image-wise. From one state to the opposite state, for example from hydrophilic to lipophilic or from ink-receptive to ink-
Contains a layer that can be converted to repellency. Such a material can be converted from a hydrophobic state to a hydrophilic state as per the image (WO 92
/ 09934; EP 652 483) or vice versa (US 4,081,572; EP 200 488;
EP 924 065) switchable polymers which can be converted (eg EP 924 102); heat-induced coalescence of thermoplastic polymer particles in a crosslinked binder (US Pat. No. 3,476,9)
37; EP-A 882 583; Research
Disclosure no. 33303), heat-induced destruction of microcapsules and subsequent reaction of microencapsulated lipophilic compounds with functional groups on cross-linked hydrophilic binders (US 5,569,573; EP
646 476; EP 949 088).

[0006] A major problem with the above-described non-absorptive unprocessed plates is the poor differentiation of lithographic images, ie, exposure and non-
A small difference in the hydrophilicity / lipophilicity of the exposed areas, resulting in poor print quality, is a major reason such materials have not found practical use so far. The poor differentiation is due to the fact that both image and non-image areas are demarcated by the same layer, the image-like conversion of one of the layers from one state to the other being the same in the exposed layer. Are removed by wet processing or ablation, whereby the lower layer has an affinity for the ink or ink-repellent fluid that is very different from the image-recording layer, such as in other plate materials where the support appears. Not.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a printing method in which a non-ablationable unprocessed imaging material is used for making a lithographic printing plate that gives high quality prints. This object is achieved by the preferred embodiments defined in the method of claim 1 and the dependent claims. In the method according to the invention, known switchable materials are combined with so-called single-fluid inks. Single fluid inks are generally understood as emulsions of the polar phase in the polar phase or vice versa. Surprisingly, in the present invention, when a single fluid ink is used instead of the usual ink / fountain mixture, poor differentiation of the lithographic image of the switchable plate material gives high quality prints. Was found. Printing with a single fluid ink is an alternative to the usual offset method in which the ink and aqueous dampening fluid are supplied to the plate. Single-fluid inks allow printing on conventional "wet" offset printing presses without supplying an aqueous dampening solution to the plate. Single fluid inks also allow the use of wet-offset plates in driographic printing presses that do not include a fountain solution supply.

[0008] Further advantages and embodiments of the present invention will become apparent from the following description.

[0009]

DETAILED DESCRIPTION OF THE INVENTION The imaging material used in the method of the present invention comprises a switchable image-recording layer, i.e. an ink or ink-repellent fluid upon exposure to heat or light,
For example, including a layer whose affinity for an aqueous dampening solution can be converted from one state to another. The present invention does not require that the layer be switched over its entire thickness, and it may be sufficient that only the surface of the layer be switched,
Lithographic printing is a surface-dr process
This is because it is an even process. The image-recording layer or surface cannot be removed with the single-fluid ink supplied during the printing step, for example, it is not soluble in the single-fluid ink or does not form an emulsion therein.

Immediately after image-wise exposure, the image-recording layer is a lithographic plate comprising hydrophilic and oleophilic regions ("wet" offset plates) or ink-receptive and ink-repellent regions (dryographic plates). Contains printed images. In the case of a negative-working embodiment, the image (printing) area, ie the lipophilic or ink-receiving area, corresponds to the exposed area. In the case of the positive-working embodiment, the non-image (non-printing) area, ie the hydrophilic or ink-repellent area, corresponds to the exposed area. In a preferred "wet" offset embodiment, the image-recording layer is hydrophilic prior to exposure and can be switched to a lipophilic state upon exposure. Alternatively, the image-recording layer is lipophilic prior to exposure and can be switched to a hydrophilic state upon exposure. In a preferred positive-working embodiment of the "wet" offset plate used in the present invention, the non-exposed areas receive the ink phase of a single fluid ink and the exposed areas receive the polar phase of a single fluid ink. In a preferred negative-working embodiment of the "wet" offset plate used in the present invention, the exposed areas receive the ink phase of a single fluid ink,
The non-exposed areas receive the polar phase of the single fluid ink.

Before moving on to the preferred composition of such "switchable" image-recording materials, some general features common to all embodiments will first be discussed.

The material can be light or heat sensitive. In a preferred photosensitive embodiment, UV light initiates a photochemical reaction in the image-recording layer, which switches the image-recording layer from one state of affinity for ink or ink-repellent fluid to the opposite state. The material is preferably heat-sensitive, so that the image-wise exposure can be, for example, direct exposure to heat by a thermal head. More preferably, heat-mode exposure is performed by absorption of one or more compounds in the image-recording layer that can convert light, more preferably infrared light to heat. Particularly useful light-to-heat conversion compounds are, for example, dyes,
Pigment, carbon black, metal carbides, borides, nitrides, carbonitrides, bronze-structured oxides and conductive polymer dispersions, for example conductive polymer dispersions based on polypyrrole, polyaniline or polythiophene. Infrared dyes and carbon black are highly preferred.

[0013] Alternatively, the light-to-heat conversion compound can be in a separate layer adjacent to the image-recording layer. Thus, absorption can occur in the image-recording layer itself and / or in another light-to-heat conversion layer. Additional layers between the support and the light-absorbing layer or layers, e.g. so-called primers or primers which promote the adhesion of other layers to the support or dyes which absorb light passing through the light-absorbing layer or layers or There can be an antihalation layer containing a pigment. One or more layers that provide protection against handling or mechanical damage can also be provided over the image-recording layer. One or more such protective top layers must be soluble in the single fluid ink supplied during the printing stage.
Suitable protective top layers include polyvinyl alcohol.

The material is preferably insensitive to daylight. Daylight is understood to be in the wavelength range from about 300 nm to about 750 nm. "Insensitive" means "substantially insensitive", i.e., a conversion of the image-recording layer sufficient to obtain differentiation between exposed and non-exposed areas that produces a visible result on the printed copy. Because it does not cause light exposure,
It should be understood that the material can be handled in daylight without darkroom conditions. More specifically, preferred materials are diazo compounds, photoacids (photoacids).
ds), free of photosensitive components such as photoinitiators or quinonediazides.

[0015]

Support The support used in the method of the present invention comprises an ink and / or an ink, since the image-recording layer remains on the support in the exposed and non-exposed areas after exposure and during the printing stage. It can have any affinity for repellent fluids. In a preferred embodiment, the support has a highly hydrophilic or hydrophobic character and can enhance differentiation between exposed and non-exposed regions.

The support can be a sheet-like material, for example a plate, or it can be mounted on a printing cylinder of the printing press instead of mounted on the printing press as in the case of a conventional printing plate. It can be a cylindrical element such as a slidable sleeve. Preferred supports are plastic sheets or metal plates such as aluminum.

A particularly preferred support is an electrochemically polished and anodized aluminum support. The anodized aluminum support can be treated to increase its surface hydrophilicity. For example, an aluminum support can be silicided by treating its surface with a sodium silicate solution at an elevated temperature, eg, 95 ° C. Alternatively, a phosphating can be performed, which comprises treating the aluminum oxide surface with a phosphating solution, wherein the phosphating solution can further contain inorganic fluoride. Further, the aluminum oxide surface can be rinsed with a citric acid or citrate solution. This treatment can be performed at room temperature or at a slightly elevated temperature of about 30-50 ° C. A further interesting treatment involves rinsing the aluminum oxide surface with a bicarbonate solution. In addition, polyvinyl phosphonic acid, polyvinyl methyl phosphonic acid, polyvinyl alcohol, phosphate ester of polyvinyl alcohol, polyvinyl sulfonic acid, polyvinyl benzene sulfonic acid, polyvinyl alcohol formed by reaction with sulfate ester of sulfonated aliphatic alcohol and sulfonated aliphatic aldehyde. It can be processed using acetal. It is further apparent that one or more of these post-treatments can be performed alone or in combination. A more detailed description of these processes is given in GB-A-1084.
070, DE-A-4 423 140, DE-A-4
417 907, EP-A-659 909, EP-
A-537 633, DE-A-4 001 466,
EP-A-292 801 and EP-A-291 760
And U.S. Pat. No. 4,458,005.

According to another embodiment, the support can be a flexible support, which is preferably provided with a primer layer. The flexible support is, for example, paper, plastic film, thin aluminum or a laminate thereof.
Preferred examples of the plastic film are polyethylene terephthalate film, polyethylene naphthalate film, cellulose acetate film, polystyrene film,
For example, a polycarbonate film. The plastic film support can be opaque or transparent. A particularly suitable primer layer for use in accordance with the present invention is EP
-A-615524, EP-A-620 502 and E
It comprises a hydrophilic binder and a colloidal silica as disclosed in P-A-619 525. Preferably the amount of silica in the adhesion improving layer is 200mg / m ² ~750mg / m ²
It is. Further, the ratio of silica to hydrophilic binder preferably more than 1 and the surface area of the colloidal silica is preferably at least 300 meters ² / gram, more preferably at least 500 meters ² / gram.

In order to improve the hydrophilicity of the support, a so-called base layer can be provided on the support. Preferred base layers are obtained from hydrophilic binders cross-linked with a hardener such as formaldehyde, glyoxal, polyisocyanate or hydrolyzed tetra-alkyl orthosilicate. The latter is particularly preferred. The thickness of the hydrophilic base layer can vary within a range of 0.2 to 25 μm, and is preferably 1 to 10 μm. Hydrophilic binders for use in the base layer include, for example, hydrophilic (co) polymers such as vinyl alcohol, acrylamide, methylol acrylamide, methylol methacrylamide, acrylate acid, methacrylic acid, hydroxyethyl acrylate, Homopolymers and copolymers of hydroxyethyl methacrylate or maleic anhydride / vinyl methyl ether copolymer. The hydrophilicity of the (co) polymer or (co) polymer mixture used is preferably equal to or higher than the hydrophilicity of the polyvinyl acetate hydrolyzed to at least 60% by weight, preferably to the extent of 80% by weight. . The amount of hardener, especially tetraalkyl orthosilicate, is preferably at least 0.2 parts by weight, more preferably 0.5 to 5 parts by weight, most preferably 1 to 3 parts by weight per part by weight of hydrophilic binder. It is.

[0020] The hydrophilic base layer can also contain substances that improve the mechanical strength and porosity of the layer. Colloidal silica can be used for this purpose. The colloidal silica used can be in the form of any commercially available aqueous dispersion of colloidal silica having, for example, an average particle size of at most 40 nm, for example 20 nm. In addition, inert particles of larger dimensions than colloidal silica, for example J.I. Colloid and Interf
ace Sci. , Vol. 26, 1968, page
StOeb as described in s 62 to 69
Particles having an average diameter of at least 100 nm can be added, which are silica or alumina particles or particles of titanium dioxide or other heavy metal oxides prepared according to er. The introduction of these particles gives the surface of the hydrophilic base layer a uniform rough texture consisting of microscopic hills and valleys, which serves as a reservoir for water in the background area. Specific examples of suitable hydrophilic base layers for use in accordance with the present invention are disclosed in EP-A-601 240, GB
-P-1 419 512, FR-P-2 300 3
54, US-P-3 971 660 and US-P-4
284 705.

[0021]

Switchable Image-Recording Layer Any switchable image-recording material for making a lithographic printing plate benefits from the solution provided by the present invention. Therefore, it must be understood that the compositions described below are of a preferred type without limiting the invention thereto. "Switching" is a physical mechanism, such as heat-induced polymer particle coagulation, a chemical mechanism, such as a heat- or light-induced bond-splitting or physico-chemical mechanism that leads to functional group elimination, e.g. Due to induced breakdown and release of reactive chemicals from the microcapsules. It is clear from the above that the term "heat-induction" also includes processes in which heat is generated indirectly by the absorption of incident light by the light-to-heat conversion compound, in particular by the absorption of infrared light.

The preferred embodiment of the image-recording layer discussed below is irreversible: after printing, the image-recording layer cannot be reset to its original state, so that new materials must be used. However, completely reversible switchable layers or surfaces are also known, in which an image-wise exposure step switches the layers or surfaces from one state to another, and the plate after printing press operation. Is "reset", i.e., the affinity of the layer or surface for the ink or ink repellent fluid returns to one particular state, thereby erasing the image. The layer or surface can then be re-exposed with a new image. Suitable materials are based on zirconia ceramics, examples being, for example, US 5,870,956; US 5,8
55,173 and US 5,835,248. It should be understood that printing methods for printing such reversible layers or surfaces with a single fluid ink are within the scope of the present invention.

According to a preferred embodiment of the first type, the image-recording layer contains a so-called switchable binder. In one embodiment, the switchable binder is a polymer that undergoes a polar transition from hydrophobic to hydrophilic when exposed to heat or light. The polymer preferably has pendant hydrophobic groups, which are converted to hydrophilic groups under the action of heat. More preferably, the side group is selected from the group comprising t-alkyl carboxylate, t-alkyl carbonate, benzyl carboxylate and alkoxyalkyl esters.

In a more preferred embodiment, the switchable binder undergoes a polar transition from hydrophilic to hydrophobic. Preferably, the switchable binder according to the latter embodiment is a polymer or copolymer containing pendant polar functional groups. These polar functional groups can be carboxylic acids, sulfonic acids, phosphonic acids and phenols or their salts. Sodium, potassium, ammonium or tetraalkylammonium ions can be used as counterions. Trace amounts of alkali, such as trace amounts of triethylamine and pyridine, can also be used. These hydrophilic functional groups readily react with other functional groups under the influence of heat to form a hydrophobic structure.

A more preferred switchable binder according to a preferred embodiment is a maleic acid-containing binder, the binder being hydrophilic and providing a binder containing maleic anhydride under the influence of heat, The binder is hydrophobic. Binders containing fumaric acid, itaconic acid, 3- or 4-vinylphthalic acid, cis-1,2,3,6-tetrahydrophthalic acid or cis-5-norben-endo-2,3-dicarboxylic acid are also described in the present invention. Are more preferred switchable binders. The acids can be mixed in one copolymer. Not only diacids, but also monoalkyl esters and their salts are more preferred. Such a half-
Examples of esters are monobutyl maleate copolymer, mono-isopropyl maleate copolymer,
Butoxyethyl ester copolymer, maleic acid isobutyl ester copolymer and maleic acid isooctyl ester copolymer. These half-esters can be used in combination with the corresponding dicarboxylic acid materials in one copolymer, or they can be mixed with one another or with other dicarboxylic acids or salts to form one copolymer.

Not only copolymers obtained, for example, by copolymerization of maleic acid, but also polymer derivatives, for example, obtained by grafting maleic acid onto unsaturated polyolefins, are very suitable switchable polymers.
Preferably, switchable binders according to the latter embodiment are preferably acrylates, methacrylates, vinyl halides, vinyl esters, vinyl ethers such as n-butyl-, isobutyl- and 2-chloroethyl vinyl ether and olefins such as propylene, isobutylene And 1-octadecene. Compounds selected from the group consisting of methyl vinyl ether copolymer, ethene copolymer and styrene copolymer are more preferred. Most preferably, the binder is a copolymer containing maleic acid and vinyl methyl ether.

The weight ratio of dicarboxylic acid monomer to comonomer is from 100: 0 to 20:80 or that the structure or state (ie, anhydride or other) is sufficient to affect the overall solubility of the top layer. it can. Typically, due to the tendency to alternating copolymerization, the ratio is 50:
It is around 50. The molecular weight is generally 5,000-70,0
00 weight average molecular weight, preferably 10,000-4
0,000 g / mol.

The imaging layer can contain more than one switchable polymer, but that is not preferred.
The imaging layer can also include further binders to enhance the hydrophilicity or hydrophobicity of the layer. As the hydrophilic binder, a hydrophilic (co) polymer such as acrylamide, methylol acrylamide, methylol methacrylamide, acrylic acid, methacrylic acid, hydroxyethyl acrylate, a homopolymer and copolymer of hydroxyethyl methacrylate or a maleic anhydride / vinyl methyl ether copolymer may be used. Can be used. The hydrophilicity of the (co) polymer or (co) polymer mixture used is preferably equal to or higher than the hydrophilicity of the polyvinyl acetate hydrolyzed to at least 60% by weight, preferably to the extent of 80% by weight. . A preferred hydrophilic binder is polyvinyl alcohol.

Water-insoluble polymers such as cellulose esters, copolymers of vinylidene chloride and acrylonitrile, poly (meth) acrylates and polyvinyl chloride can be used as hydrophobic binders. Preferred hydrophobic binders are hydrophobic binders such as those used in conventional positive- or negative-acting PS-plates, such as novolak, polyvinylphenol, carboxy-substituted polymers and the like. A typical example of these polymers is DE
-A-4 007 428, DE-A-4 027 3
01 and DE-A-4 445 820.

Particular examples of switchable image-recording layers suitable for use in this embodiment are EP 924 102; WO
92/09934; EP 652 483; US 4,
081,572; EP 200 488; and EP 9
24 065 can be found.

According to a second type of preferred embodiment, the image-recording layer comprises hydrophobic thermoplastic polymer particles in a cross-linked hydrophilic binder. Preferably, the hydrophilic binder is a homopolymer or copolymer of vinyl alcohol, acrylamide, methylolacrylamide, methylol methacrylamide, acrylic acid, methacrylic acid, hydroxyethyl acrylate, hydroxyethyl methacrylate or a maleic anhydride / vinyl methyl ether copolymer. The hydrophilicity of the (co) polymer or (co) polymer mixture used is preferably equal to or higher than the hydrophilicity of the polyvinyl acetate hydrolyzed to at least 60% by weight, preferably to the extent of 80% by weight. . Polyvinyl alcohol is highly preferred.

The crosslinker is preferably a tetraalkyl orthosilicate crosslinker, such as hydrolyzed tetraethylorthosilicate and hydrolyzed tetramethylorthosilicate. The amount of the tetraalkyl orthosilicate crosslinking agent is at least 0.2 parts by weight, preferably 0.5 to 5 parts by weight per part by weight of the hydrophilic (co) polymer,
Preferably it is 1.5 parts by weight.

The hydrophilic layer of the thermal recording material preferably also contains substances which improve the mechanical strength and the porosity of the layer. Colloidal silica can be used for this purpose. The colloidal silica used can be in the form of any commercially available water-dispersion of colloidal silica having, for example, an average particle size of at most 40 nm, for example 20 nm. In addition, inert particles of larger dimensions than colloidal silica, for example J.I. Colloid and Interf
ace Sci. , Vol. 26, 1968, page
StOeb as described in s 62 to 69
Particles having an average diameter of at least 100 nm can be added, which are silica or alumina particles or particles of titanium dioxide or other heavy metal oxides prepared according to er. The introduction of these particles gives the surface of the layer a uniform rough texture consisting of microscopic hills and valleys, which serves as a reservoir for water in background areas. Further details on suitable hydrophilic layers for use in connection with this embodiment are described, for example, in GB-P-1419512, FR
-P-2300354, US 3971660, US
4284705, EP-A-405016 and EP-A
-450199.

[0034] The hydrophobic thermoplastic polymer particles preferably have a softening or melting temperature above 30 ° C, more preferably above 40 ° C. There is no particular upper limit on the softening or melting temperature of the thermoplastic hydrophobic polymer particles, but the temperature must be well below the decomposition of the polymer particles.
Preferably the softening or melting temperature is at least 10 ° C below the temperature at which the decomposition of the polymer particles occurs. When the polymer particles are subjected to a temperature above their softening point or melting point, they coagulate to form hydrophobic agglomerates in the hydrophilic layer, and in these parts the hydrophilic layer Will be sufficiently hydrophobic to accept greasy inks in lithographic printing.

Specific examples of hydrophobic polymer particles for use in connection with this embodiment include, for example, polyethylene, polyvinyl chloride, polymethyl (meth) acrylate, polyethyl (meth) acrylate, polyvinylidene chloride, polyacrylonitrile, polyvinyl carbazole Or copolymers thereof. Most preferably used is polystyrene. The molecular weight of the polymer is 5,000 to 1,0
It can be in the range of 00,000. The hydrophobic particles are 0.01 μm to 50 μm, more preferably 0.05 μm
It can have a particle size of from 10 to 10 μm, most preferably from 0.05 to 2 μm. The larger the polymer particles, the lower the resolution of the thermal recording material. US 3,47
The polymer particles can be prepared by the method disclosed in US Pat. The amount of the hydrophobic thermoplastic polymer particles contained in the hydrophilic layer is preferably from 20% by weight to
65% by weight, more preferably 25% to 55% by weight,
Most preferably, it is 30% to 45% by weight.

According to a preferred embodiment of the third class, the image-recording layer is microcapsules capable of releasing lipophilic material which breaks when heated and then preferably reacts with the crosslinked hydrophilic binder. including. Specific examples which are suitable are described in US 5,569,573; EP 646 476.
And EP 949 088.

[0037]

Single Fluid Inks Single fluid inks suitable for use in the method of the present invention are described in US Pat. No. 4,045,232;
981,517 and US 6,140,392. A single-fluid ink is generally understood as an emulsion of the polar phase in the polar phase or vice versa. The ink phase is also called the hydrophobic or lipophilic phase. The polar phase is preferably at least 50
%, More preferably at least 70%, even more preferably at least 90% non-aqueous polar liquid.
In a most preferred embodiment, the polar phase comprises an organic polar liquid and is essentially free of water. The polar liquid is preferably a polyol. A highly preferred single fluid ink is WO
00/32705, the relevant contents of which are reproduced herein below.

The hydrophobic phase preferably comprises a vinyl resin having a carboxyl function. The term "vinyl resin" includes polymers produced by chain reaction polymerization or addition polymerization via carbon-carbon double bonds using vinyl monomers and monomers copolymerizable with vinyl monomers. Typical vinyl monomers include, but are not limited to, vinyl ester, acrylic and methacrylic monomers, and vinyl aromatic monomers including styrene. By including a monomer having two reactive sites in the polymerization reaction, the vinyl polymer can be branched. If the vinyl polymer branches, it remains effectively soluble regardless. By "soluble" it is meant that the polymer can be diluted with one or more solvents. (By contrast, polymers can be cross-linked into an insoluble three-dimensional network that is only swollen by solvent.) The branched vinyl resin retains solvent dilutability despite significant branching.

The carboxyl-functional vinyl polymer is a monomer mixture comprising at least one acid-functional monomer or a group which is converted into an acid group following polymerization, such as at least one monomer having an anhydride group. Can be produced by polymerization. Examples of acid-functional or anhydride-functional monomers are α, β-ethylenically unsaturated monocarboxylic acids containing 3 to 5 carbon atoms, such as acrylic acid, methacrylic acid and crotonic acid; Α, β-ethylenically unsaturated dicarboxylic acids containing 6 carbon atoms and anhydrides and monoesters of these acids,
Examples include, but are not limited to, maleic anhydride and fumaric acid; and acid-functional derivatives of copolymerizable monomers, such as the hydroxyethyl acrylate half-ester of succinic acid.

Acid-functional monomers such as acrylic acid, methacrylic acid or crotonic acid or anhydride monomers which can be hydrated to form acid groups after polymerization, such as maleic anhydride or itaconic anhydride Is preferred. The acid-functional vinyl polymer has an acid number of at least about 3 mg KOH per gram of non-volatiles, preferably about 6 to about 30 mg KOH per gram of non-volatiles, based on the weight of non-volatiles of the vinyl polymer, more preferably It preferably has an acid number of about 8 to about 25 mg KOH per gram of non-volatiles.

In a preferred embodiment, the acid-functional polymer is significantly branched. The ink used in the present invention is:
It preferably comprises a branched but effectively soluble vinyl polymer. Branched vinyl polymers can be diluted rather than swelled by the addition of solvent. Branching can be done in at least two ways. In the first method, a monomer having two or more polymerizable double bonds is included in the polymerization reaction. In the second method, a pair of ethylenically unsaturated monomers each having, in addition to the polymerizable double bond, at least one additional functional group that is reactive with additional functional groups on the other monomer. , In the monomer mixture to be polymerized. Preferably, the reaction of the additional functional groups takes place during the polymerization reaction, but it does not seem to be critical, and the reaction of the additional functional groups can be performed partially or completely before or after the polymerization. A variety of such mutually reactive group pairs are possible. Representative examples of such reactive group pairs include epoxide and carboxyl groups, amine and carboxyl groups, epoxide and amine groups, epoxide and anhydride groups, amine and anhydride groups, hydroxyl and carboxyl or anhydride groups,
Amine and acid chloride groups, alkylene-imine and carboxyl groups, organic alkoxysilanes and carboxyl groups,
Examples include, but are not limited to, isocyanate and hydroxyl groups, cyclic carbonate and amine groups, isocyanate and amine groups, and the like. If carboxyl or anhydride groups are included as one of the reactive groups, they are used in a vinyl resin in a sufficient excess to provide the required carboxyl functionality. Specific examples of such monomers include glycidyl (meth) acrylate and (meth) acrylic acid, N-alkoxymethylated acrylamides (reacting with themselves), such as N-isobutoxymethylated acrylamide, gamma-methacryloxytriamide. Includes, but is not limited to, alkoxysilanes (which react with themselves) and combinations thereof.

Preferably two or more polymerizable ethylenically unsaturated bonds, particularly preferably 2 to about 4
The vinyl resin is polymerized using at least one monomer having two polymerizable ethylenically unsaturated bonds. 2
Representative examples of monomers having one or more ethylenically unsaturated moieties include (meth) acrylate esters of polyols alone or in combination of two or more such as 1,4-butanediol di ( (Meth) acrylate, 1.6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, tetramethylolmethanetetra (meth) acrylate, pentaerythritol tetra (meth) acrylate Dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, alkylene glycol di (meth) acrylate and polyalkylene glycol di (meth) acrylate, for example, ethyl Glycol di (meth) acrylate, butylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate and polyethylene glycol di (meth) acrylate; divinylbenzene, allyl methacrylate, diallyl phthalate, diallyl terephthalate Includes, but is not a limitation. Of these, divinylbenzene, butylene glycol dimethacrylate, butanediol dimethacrylate, trimethylolpropane triacrylate and pentaerythritol tetra-acrylate are highly preferred, and divinylbenzene is even more highly preferred.

Preferably, 100 of the monomers to be polymerized
At least about 0.008 equivalents per gram of at least one monomer having at least two ethylenically unsaturated polymerizable bonds or 10
The branched vinyl polymer is polymerized using 0.004 equivalents per gram of each of two monomers having mutually reactive groups in addition to the ethylenically unsaturated polymerizable linkage. Preferably about 0.012 to about 0.08 equivalents, more preferably about 0.016 to about 0.064 equivalents of multifunctional monomer or at least two ethylenically unsaturated polymerizable linkages per 100 grams of monomer to be polymerized. Having one or more polymerized bonds and additional one
Using a pair of monomers having two mutually reactive groups,
The branched vinyl polymer is polymerized.

The monofunctional or polyfunctional monomers preferably have 2 to 4 ethylenically unsaturated polymerizable bonds, more preferably 2 ethylenically unsaturated polymerizable bonds. In one embodiment, about 0.5% to about 6%, more preferably about 1.2% to about 6%, and more preferably about 1.2%, based on the total weight of the monomers to be polymerized.
It is preferred to produce a branched vinyl resin by polymerizing a mixture of monomers containing from about 5% to about 4%, and even more preferably from about 1.5% to about 3.25% divinylbenzene. (Commercial brand divinylbenzene is one-
It includes functional and / or non-functional materials. The amount of commercial material required to give the indicated percentage must be calculated. For example, 5% by weight of a material that is 80% by weight divinylbenzene / 20% monofunctional monomer would give a rate of 4% by weight divinylbenzene. And b) a combination of (1) divinylbenzene or another monomer having at least two polymerizable ethylenically unsaturated bonds or (2) a monomer having a polymerizable group and a monomer having an additional mutually reactive group contained in the polymerization mixture. The optimal amount will depend on the particular reaction conditions, such as the rate of monomer addition during polymerization,
The solubility of the resulting polymer in the selected reaction medium, the amount of monomer relative to the reaction medium, the half-life of the selected initiator at the reaction temperature and the weight of the monomer (by weight of the monomer)
rs) depends to some extent on the amount of initiator, and can be determined by straightforward testing.

Other monomers that can be polymerized together with the polyfunctional monomer and the acid-functional monomer (or a monomer having a group that can be subsequently converted to an acid group) include 3-5 carbon atoms. Esters of α, β-ethylenically unsaturated monocarboxylic acids, such as acrylic acid,
Esters of methacrylic acid and crotonic acid; α, β-ethylenically unsaturated dicarboxylic acids containing 4 to 6 carbon atoms and anhydrides, monoesters and diesters of these acids; vinyl esters, vinyl ethers, vinyl ketones and aromatic or Heterocyclic aliphatic vinyl compounds are included, but are not limited. Representative examples of suitable esters of acrylic acid, methacrylic acid and crotonic acid include 1-20
Esters from the reaction with saturated aliphatic and cycloaliphatic alcohols containing 10 carbon atoms, such as methyl, ethyl, propyl acrylic acid, methacrylic acid and crotonic acid,
Examples include, but are not limited to, isopropyl, n-butyl, isobutyl, tert-butyl, 2-ethylhexyl, lauryl, stearyl, cyclohexyl, trimethylcyclohexyl, tetrahydrofurfuryl, stearyl, sulfoethyl and isobornyl; and polyalkylene glycol acrylates and methacrylates. Representative examples of other ethylenically unsaturated polymerizable monomers include monoesters with alcohols such as fumaric acid, maleic acid and itaconic anhydride, methanol, ethanol, propanol, isopropanol, butanol, isobutanol and tert-butanol. And compounds such as, but not limited to, diesters. Representative examples of polymerized vinyl monomers include, but are not limited to, compounds such as vinyl acetate, vinyl propionate, vinyl ethers such as vinyl ethyl ether, vinyl and vinylidene halides, and vinyl ethyl ketone. Representative examples of aromatic or heterocyclic aliphatic vinyl compounds include styrene, α
Including but not limited to compounds such as -methylstyrene, vinyltoluene, tert-butylstyrene and 2-vinylpyrrolidone. The choice of monomer is made based on various factors commonly considered in the manufacture of ink varnishes, including the desired glass transition temperature and the desired dilutability of the resulting polymer in the solvent or solvent system in the ink composition. .

Preferred vinyl polymers can be prepared by using radical polymerization in a conventional manner, preferably in a semi-batch process. For example, in a semi-batch process, the monomer, initiator or initiators, and chain transfer agent can be fed at a controlled rate into a suitable heated reactor charged with a solvent. Typical radical sources are dialkyl peroxides such as di-tert-butyl peroxide and dicumyl peroxide, peroxyesters such as tertiary peroxy-2-ethylhexanoate.
t-butyl and tert-butyl peroxypivalate;
Peroxycarbonates and peroxydicarbonates such as tert-butylperoxyisopropylcarbonate, di-2-ethylhexylperoxydicarbonate and dicyclohexylperoxydicarbonate; diacyl peroxides such as dibenzoyl peroxide and dilauroyl peroxide; hydroperoxides such as cumene hydroperoxide and tert-butyl hydroperoxide; ketone peroxides such as cyclohexanone peroxide and methyl isobutyl ketone peroxide; and peroxyketals such as 1,1-bis (tert-butylperoxy) -3,5,5-trimethylcyclohexane and 1,1-bis ( organic peroxides containing tert-butylperoxy) cyclohexane; and azo compounds, eg Ba 2,2'-azobis (2-methyl butane nitrile), 2,2'-azobis (2-methyl) propionitrile and 1,1'-azobis (cyclohexanecarbonitrile). Organic peroxides are preferred. Particularly preferred is tert-butyl peroxyisopropyl carbonate. Chain transfer agents can also be used in the polymerization. Typical chain transfer agents are mercaptans, such as octyl mercaptan, n- or t-
tert-dodecyl mercaptan, thiosalicylic acid, mercaptocarboxylic acids such as mercaptoacetic acid and mercaptopropionic acid and their esters and mercaptoethanol; halogenated compounds; and α-methylstyrene dimer. It is preferably free of chain transfer agents because of odors and other known disadvantages. The particular initiator and amount of initiator used will depend on factors known to those skilled in the art, such as reaction temperature, amount and type of solvent (for solution polymerization), half-life of the initiator, and the like.

The addition polymerization is usually carried out at about 20 ° C. to about 300 ° C., preferably at about 150 ° C. to about 200 ° C., more preferably at about 1 ° C.
It is carried out in solution at a temperature of from 60C to about 165C.
The polymerization is preferably carried out at approximately the same reaction temperature throughout and using the same initiator or initiators. The initiator preferably has a half-life at the reaction temperature of about 30
Minutes or less, particularly preferably less than about 5 minutes, and even more preferably less than about 2 minutes. Particularly preferred are initiators having a half-life of less than about 1 minute at a temperature of about 150C to about 200C. In general,
If the half life of the disclosed agent is shorter and / or if more initiator is used, more branched monomer (b
(Ranching monomer). The vinyl polymer vehicle used in the ink preferably has little or no residual (unreacted) monomer content. In particular, the vinyl vehicle is preferably substantially free of residual monomers, i.e., less than about 0.5% by weight residual monomers, even more preferably less than about 0.1% by weight, based on the total weight of polymerized monomers. Has monomers.

In a semi-batch process, the monomers and initiator are added to the polymerization reactor over time, preferably at a constant rate. Typically, the addition time is from about 1 to about 10 hours, with addition times of from about 3 to about 5 hours being common. Longer addition times typically result in lower number average molecular weights. Lower number average molecular weights can also be produced by increasing the solvent to monomer ratio or by using stronger solvents for the resulting polymer.

In general, the branched vinyl polymers used in the ink have a low number average molecular weight and a wide polydispersity. The number average molecular weight and weight average molecular weight of the vinyl resin used in the ink can be determined by gel permeation chromatography using polystyrene standards according to well accepted methods, with polystyrene standards up to a weight average molecular weight of 6 million. Is available. Polydispersity is defined as the ratio of M _w / M _n . In a preferred embodiment, the vinyl polymer has a number average molecular weight ( _Mn ) of at least about 1000, more preferably at least about 2000.
Having. The number average molecular weight is preferably about 15,000.
It is less than 0, more preferably less than about 10,000, and even more preferably less than about 8500. Preferred range for M _n is from about 1000 to about 10,000, M _n
A more preferred range for is from about 2000 to about 8500, and an even more preferred range is from about 4000 to about 80
00. The weight average molecular weight is at least about 30,00
It should be 0, preferably at least about 100,000. The weight average molecular weight (M _w ) is preferably at most about 60 million based on GPC determination using available standards having a weight average molecular weight of 6 million. A preferred range for M _w is from about 30,000 to about 55 million, and a more preferred range for M _w is about 100,000.
To about one million, and an even more preferred range is about 10
It is between 000 and about 300,000. Ultra-high shoulders known by GPC
molecular weight shoulde
rs) (greater than about 45 million) has about 1
In the case of 00,000～ about 300,000 of M _W range, preferably avoided. The polydispersity or M _w / M _n ratio is
It can be up to about 10,000, preferably up to about 1000. The polydispersity is preferably at least about 15, particularly preferably at least about 50. The polydispersity is preferably comprised between about 15 and about 1000,
More preferably, it falls within the range of about 50 to about 800.

According to methods well known in the art, the selection and assignment of comonomers (appratio)
the theoretical glass transition temperature can be adjusted via the In a preferred embodiment, the theoretical T _g is above room temperature, preferably the theoretical T _g is at least about 60
° C, more preferably at least about 70 ° C. The methods and compositions of the present invention are preferably at about 50 ° C to about 125 ° C,
More preferably from about 60 ° C. ~ about 100 ° C., even more preferably to use a vinyl polymer having a T _g of about 70 ° C. ~ about 90 ° C..

In one embodiment of the single fluid ink, an acid-functional vinyl polymer, which can be a branched vinyl polymer, is combined with another resin in the ink composition. Examples of other suitable resins that can be combined with the acid-functional vinyl polymer include polyester and alkyd resins, phenolic resins, rosins, cellulosic materials and derivatives thereof, such as rosin-modified phenolic materials, phenolic Materials-modified rosin, hydrocarbon-modified rosin, maleic acid modified rosin, fumaric acid modified rosin; hydrocarbon resins, other acrylic or vinyl resins,
A polyamide resin or the like is included, but is not limited. Such resins or polymers can be included in amounts up to about 6 parts to about 1 part by weight of the acid-functional vinyl polymer, based on the weight of the non-volatiles of the resin.

[0052] In addition to the acid-functional vinyl resin and the optional second resin, the ink composition preferably contains one or more solvents. In a preferred embodiment of the single fluid ink, the branched vinyl resin forms a solution or an apparent solution having no pronounced turbidity in the solvent or solvents of the ink preparation. The particular solvent and amount of solvent included is determined by the desired viscosity, body, and tack of the ink. Generally, for inks that will come into contact with rubber parts such as rubber rollers during the lithographic printing process, one or more inks having low Kauri-Butanol (KB) values are used to avoid affecting the rubber. A non-oxygenated solvent is used. Suitable solvents for the inks that will come into contact with the rubber parts include, but are not limited to, aliphatic hydrocarbons, such as petroleum distillates with limited aromaticity and normal and isoparaffinic solvents. For example, petroleum middle distillate (petroleum middle distillate)
tile fractions), such as Pen
nsylvania Refining Compan
y, Franklin Park, Ill. A subsidiary of Magie Bros. Available under the trade name Magie Sol available from the Oil Company, Exxon C under the trade name ExxPrint
chemicalCo. , Houston, Tex. And GoldenBear Oil available from
Specialties, Oildale, Cali
f. , Total Petroleum Inc. , D
ever, Colo. And Calumet Lubr
icants Co. , Indianapolis, I
nd. Can be used. Additionally or alternatively, soybean oil or other vegetable oils may be included.

When a non-oxygenated solvent such as these is used, generally at least one having a substantial affinity for the aliphatic solvent in an amount sufficient to obtain the desired solvency of the preferred branched vinyl polymer. Need to be included. For this purpose, acrylic ester monomers or styrene or alkylated styrene, such as tert-butylstyrene, generally having at least 6 carbons in the alcohol portion of the ester, may be included in the polymerized monomer. In a preferred embodiment, the non-
The ink composition using the oxygenated solvent has at least about 20
%, Preferably about 20% to about 40%, more preferably about 20% to about 25%, of a monomer that promotes aliphatic solubility;
Stearyl methacrylate is a preferred such monomer, for example, comprising a branched vinyl resin polymerized from a monomer mixture containing stearyl methacrylate or t-butylstyrene. At least about 55% styrene,
Preferably, it also contains about 55% to about 80% styrene, more preferably about 60% to about 70%. If necessary, methyl methacrylate or other monomers can be used to reduce solvent tolerance in aliphatic solvents. All percentages are by weight based on the total weight of the monomer mixture to be polymerized. Among the preferred monomer compositions for vinyl polymers for lithographic printing inks, (meth) acrylates of alcohols having 8 to 20 carbon atoms, such as stearyl methacrylate, styrene, divinylbenzene and (meth) acrylic Some contain acids. In a preferred embodiment, the branched vinyl for the lithographic printing ink has about 1
5, preferably about 20 to about 30, preferably about 25 weight percent of (meth) acrylates of alcohols having 8 to 20 carbon atoms, especially stearyl methacrylate; about 50, preferably about 60 to about 80, Preferably about 75 weight percent of the styrenic monomer, especially styrene itself; divinylbenzene in the amounts indicated above; and about 0.5, preferably about 2.5 to about 5, preferably about 4 weight percent of acrylic acid or More preferably, it is made using methacrylic acid.

[0054] Preferably, the solvent or solvent mixture will have a boiling point of at least about 100 ° C and preferably no more than about 550 ° C. Offset printing ink is about 200
Solvents having a boiling point above ℃ can be used. Newsprint inks typically contain about 20 to about 85 weight percent mineral oil,
It is prepared using solvents such as vegetable oils and high boiling petroleum distillates. The amount of solvent depends on the type of ink composition (i.e., the ink is in newsprint, heatset, sheetfeet).
d), etc.), the particular solvent used and other factors known in the art. Typically, the solvent content for lithographic printing inks is up to about 60%, which is
Oil may be included as part of the vent package. Usually at least about 35% of the solvent is present in the lithographic printing ink. When used to prepare a preferred single fluid ink composition, these varnishes or vehicles containing the branched vinyl resin are typically clear, apparently solutions.

[0055] The ink composition will usually contain one or more pigments. The number and type of pigments will depend on the type of ink being prepared. Newsprint ink compositions will typically contain only one or only a few pigments, such as carbon black, but gravure inks can include more complex pigment packages, such as pearl essence or metal. It can be prepared in many colors, including those with special effects such as sexual effects. Lithographic printing inks are typically used in four colors--magenta, yellow, black, and cyan and can be prepared for pearl essence or metallic effects. Any of the usual inorganic and organic pigments can be used in the ink compositions of the present invention. Alternatively, the composition can be used as an overprint lacquer or varnish. The overprint lacquer (air-drying) or varnish (curing) is clear or transparent (t
is intended to be
Thus, opaque pigments are not included.

The lithographic printing ink composition used in the present invention is preferably prepared as a single fluid ink having a continuous phase based on oil containing an acid-functional vinyl vehicle and a discontinuous polyol phase containing a liquid polyol. Is done. The vinyl polymer phase is relatively stable with respect to the polyol phase. Stability is that the two phases are
in such a way that they do not separate in the same manner. However, during the application of the ink, the emulsion breaks and the polyol comes to the surface and wets the areas of the plate that should not accept the ink. Inks that are stable in the sump but break and break off quickly on the plate are toning
Prints cleanly and gives consistent transfer properties. Suitable stability may also depend on the particular acid-functional vinyl polymer chosen and the particular polyol. The acid value and molecular weight can be adjusted to give the desired stability.

While relatively high acid number vinyl resins can be used in relatively small amounts, the acid number cannot be too high or the vinyl polymer will not be sufficiently soluble in hydrocarbon solvents. There will be. In general, it appears that an increase in the acid number of the acid-functional vinyl resin must be accompanied by a decrease in the amount of such resin contained in the hydrophobic phase.

Polyethylene glycol oligomers such as diethylene glycol, triethylene glycol and tetraethylene glycol and ethylene glycol, propylene glycol and dipropylene glycol are examples of preferred liquid polyols for the polyol phase of the single fluid inks used in the present invention. is there. Of course, the polyol phase can include a mixture of various liquid polyols. Generally, lower acid number vinyl or acrylic polymers are used with higher molecular weight polyols. The polyol phase may further comprise another material. A weak acid, such as citric acid, tartaric acid or tannic acid, or a weak base, such as triethanolamine, can be included in an amount from about 0.01 weight percent to about 2 weight percent of the ink composition. Certain salts, such as magnesium nitrate, may help protect the plate and extend the life of the plate, for example, from about 0.01 to about 0.5 weight percent, preferably about 0.1 to about 0.5 weight percent, based on the weight of the ink composition. 08 to about 1.5 weight percent. To aid the wetting of the plate, wetting agents such as polyvinylpyrrolidone can be added. From about 0.5 weight percent to about 1.% based on the weight of the ink composition.
Contains 5 weight percent polyvinylpyrrolidone.

From about 5% to about 50%, preferably from about 10% to about 35% by weight based on the total weight of the ink composition.
By weight, particularly preferably from about 20% to about 30% by weight of the polyol phase, a single fluid ink can be prepared. If no other means for cooling is provided, there is preferably a sufficient amount of polyol in the ink composition to keep the plate at a low temperature at which it can work. The amount of polyol phase required to achieve good toning and printing results depends on the type of plate being used and can be determined by straightforward testing. Up to about 4 or 5% by weight of water can be included in the polyol phase mixture to help dissolve or homogenize the components of the polyol phase.

It will be appreciated by those skilled in the art that such additives may be included in the ink compositions used in the present invention, as long as other additives known in the art do not significantly reduce the benefits of the present invention. You will understand. Representative examples of these include pour point depressants, surfactants, wetting agents, waxes, emulsifiers and dispersants, defoamers, antioxidants, UV absorbers, desiccants (for preparations containing vegetable oils, for example). ), Fluidizing agent (f
These include, but are not limited to, low agents and other rheology modifiers, gloss enhancers and anti-settling agents. If included,
Additives typically comprise at least about 0.0% of the ink composition.
It may be included in an amount of about 01% by weight and may be included in an amount of about 7% by weight or more of the ink composition.

The above compositions are used in heatset inks, newsprint inks and sheetfed inks.
It is particularly suitable for use in lithographic printing applications, including but not limited to k). Offset printing methods that can use inks are well known in the art and have been described in many publications.

[0062]

[Exposure Step] The image forming material used in the present invention is exposed to heat or light by, for example, a thermal head, LEDs or a laser head. Preferably, one or more lasers such as a He / Ne laser, an Ar laser or a violet laser diode are used. The light used for the exposure is not visible light, for example U.S.A., so that most preferably a daylight-stable material can be used.
A laser emitting V (laser) light or near-infrared light having a wavelength in the range of about 700 to about 1500 nm, such as a semiconductor laser diode, Nd: YAG or N
d: A YLF laser is used. The required laser output is the sensitivity of the image-recording layer, spot diameter (1/1 of the maximum intensity)
A typical value of the setter - modern plate in e ^2:
The pixel dwell time of the laser beam, the scan speed and the resolution of the exposure device (i.e., the addressable (add) units of the linear distance, often expressed as dots per inch or dpi) as determined by the
resable) number of pixels; typical values: 1000-
4000 dpi).

Two types of laser-exposure devices: internal (I
TD) and external drum (XTD) plate-setters are commonly used. Thermal plate (thermal
ITD plate-setters for plates are characterized by very high scan speeds, typically up to 500 m / s, and may require several watts of laser power. About 2
XTD plate-setters for thermal plates with typical laser powers from 00 mW to about 1 W work at lower scan speeds, for example from 0.1 to 10 m / s.

As the off-press exposure device in the present invention, a known plate-setter can be used.
This is because of the press down-time.
time). The XTD plate-setter arrangement can also be used for more favorable on-press exposure, providing the benefits of direct registration in a multi-color press. More technical details of the on-press exposure device are described, for example, in US Pat.
163,368.

[0065]

EXAMPLE Production of a heat-set single fluid ink Production of vinyl varnish Ketrul 220 (Tot) in an amount of 44.19 parts by weight
al Petroleum, Inc. From a petroleum middle distillate fraction available from Stirling, Inc., nitrogen inlet, total reflux condensers
er) and a glass reactor equipped with a monomer inlet. Remove the solvent while stirring under a blanket of nitrogen.
Heat to 60 ° C. 36.01 parts by weight of styrene, 1
2.27 parts by weight of stearyl methacrylate, 2.62
A monomer mixture of parts by weight of divinylbenzene, 1.89 parts by weight of methacrylic acid and 2.79 parts by weight of t-butylperoxyisopropyl carbonate (75% solution in mineral spirits) is added to the reactor over 3 hours.
After the monomer addition is complete, 0.23 parts by weight of t-butyl peroxyisopropyl carbonate are added over 15 minutes. The temperature is kept at 160 ° C. for a further 2 hours, allowing complete conversion of the monomer to polymer.

The measured amount of the non-volatile substance (NVM) is 55%
It is. NV divided by percent of total weight of monomer
The percent conversion measured as M is 100.1. The acid value on solution is 12.0 mg KOH per gram. The viscosity is 30 Stokes (bubble tube, 54.4 ° C.). Solvent tolerance is 2
30% and the NVM at the cloud point is 16.7%. 2. Preparation of Single Fluid Ink 58.0 grams of the following mixture A are added to 142.0 grams of the following mixture B with stirring. The vortex is maintained and the disperser is maintained at a temperature of less than 60 ° C.
The ink composition is mixed for 20 minutes on a sator). The ink composition has a weight of 14-17
Single fall time in seconds
time) having a Laray. Mixture A : 181.0 grams of diethylene glycol,
8.0 grams of water, 0.4 grams of citric acid and 0.4
Mix grams of magnesium nitrate in a glass beaker until clear. Add 191.2 grams of diethylene glycol and mix until uniform. Mixture B : 46.0 g of the above vinyl varnish, 4.0 g of Blue Flush 1 using a high speed mixer.
2-FH-320 (CDR Corporation,
Elizabethtown, Ky. Available from
1.0 gram of industrial grade soybean oil (Cargill, C
higo, Ill. And 0.6 grams of antioxidant. While mixing, 34.4 grams of the hydrocarbon resin solution (EXX-Print 283D)
60% LX-2600, available from Neville, 27.0 grams of carbon black (Cabo)
tCorp. CSX-156) and 1.
0 grams of polytetrafluoroethylene wax (Pi
nnacle 9500D, Carroll Science
(available from ticic). Mix at high speed at 149 ° C. for 30 minutes. Slow mixing speed, 27.
0 grams of EXX-Print 588D (Exxon
(Available from). The pre-mix is placed in a shot mill at a suitable grind (gri).
mill until nd).

Mixture B contains 180-240 poise Lar.
ay viscosity and a yield of 800-1200 (test method ASTM D4040)
According to: Power Law-3K, 1.5K, 0.7
K, 0.3K). Mixture B at 1200 rpm for 1 minute,
Test on Inkometer to obtain 25-29 units of measurement (for a measured resu)
lt of 25 to 29 units). Imaging Material 1 0.35 g of GANTREZ AN 139 BF (copolymer of vinyl methyl ether, maleic acid and maleic anhydride, commercially available from GAF, USA) and 0.0365 g of IR-absorbing dye IR-1 ( The following formula is dissolved in 4.5 g of a solvent mixture consisting of 44% THF, 34% methoxypropanol and 22% methyl ethyl ketone. The solution was coated on an aluminum support to a wet coating thickness of 16 μm and after drying a dry layer having a thickness of 1.15 g / m ² was obtained. This image forming element is designated CREO 3244 Tre
ndsetter (trade name of CREO, Canada)
Exposure was performed at 2400 dpi above, operating at a drum speed of 40 rpm and a laser power of 12 watts.

[0068]

Embedded image

Image forming material 2 15.7% TiO ₂ , 15.7% polyvinyl alcohol, 31.3% polyethylene latex (average particle size 0.15 μm and molecular weight 18000 g / mol), 31.
By coating a layer containing 3% hydrolyzed tetramethyl orthosilicate and 6% carbon black on a polyester support (containing a hydrophilic adhesive layer) at 30 ° C. to a dry coating thickness of 3 μm And an image forming material. The resulting material was treated with an argon ion laser (488 nm line, 225 m
W output, 70 μm spot size, scanning speed 0.1
(25 m / s). Printing Results Both exposed materials are combined with a Heidelberg GT equipped with a Dahlgren built-in ink supply / fountain system
It was mounted on the printing cylinder of an O52 printing press. Start the printing press,
The single fluid ink described above was applied to the image-recording layer. No dampening solution was supplied. A clear print with no ink absorption in the non-image areas was obtained.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03F 7/004 505 G03F 7/004 505 4J039 521 521 (72) Inventor Giyoan Belmercille Belgium B 2640 Malt cell septes trato 27 Agfa-Gevert Nurse Frozen F-note (F) (reference) AA03 AA04 AA05 BA06 BC10 DA41 DA48 DA52 FA43 FA44 2H114 AA05 AA22 AA23 AA24 BA01 BA06 BA10 DA41 DA48 DA51 DA74 DA79 EA01 EA04 EA08 GA01 GA29 4J039 AD08 BC07 CA06 GA02

Claims (10)

[Claims] An image-forming material comprising a support and an image-recording layer or image-recording surface is provided, wherein said layer or surface is removed using a single fluid ink containing an ink phase and a polar phase. Not exposing the image-forming material image-wise to heat or light without substantially ablating the image-recording layer or surface;
Thereby switching the affinity of the image-recording layer or surface for the ink or ink-repellent fluid, and thereby the unexposed areas having an affinity for one of the ink phase and the polar phase and the ink phase and Making a printing master containing a lithographic image consisting of exposed areas having an affinity for the other of the polar phases; a lithographic printing method comprising supplying a single fluid ink to the printing master for printing. 2. The method according to claim 1, wherein the image-recording layer or surface is switched from lipophilic to hydrophilic by exposure. 3. The method according to claim 1, wherein the image-recording layer or surface is switched from a hydrophilic state to a lipophilic state by exposure. 4. The method according to claim 1, wherein the imaging material is a reversible switchable material whose lithographic image is erased after a printing step. 5. The method according to claim 1, wherein the imaging material comprises an infrared absorbing compound and is exposed to infrared light. 6. The method according to claim 1, wherein the imaging material is exposed to ultraviolet light. 7. The method according to claim 1, wherein the imaging element is insensitive to daylight. 8. The method according to claim 1, wherein the exposing step is performed while the imaging material is being loaded on the printing press. 9. Switching of the affinity of the image-recording layer or surface for the ink or ink-repellent fluid-heat-induced polymer particle coagulation or-heat- or light-induced coupling leading to functional group elimination. A method according to any of claims 1 to 8, which is due to fission or-heat-induced destruction of the microcapsules. 10. The method according to claim 1, wherein the single fluid ink is an emulsion comprising: a continuous ink phase comprising an acid-functional vinyl resin; and a discontinuous polar phase comprising a liquid polyol.