JP2002321331A - On-press exposure and on-press process of lithographic material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To offer a lithographic method possible to conduct an on-press process together with automatic plate loading and on-press exposure in all the lithographic press. SOLUTION: The method consists of six stages: (i) a web of an imaging material including (1) a soft lithographic base material having a hydrophilic surface and (2) an image recording layer removable with a single-fluid ink or with the single-fluid ink by being exposed to heat and light are rewound from a supply spool, (ii) the imaging material is wounded around a cylinder of a printing press, (iii) the image recording layer is exposed to the heat or the light image-wise, (iv) a printing master is obtained by supplying the single- fluid ink and processing the image recording layer, (v) printing is conducted by supplying the single-fluid ink to the printing master installed in a plate cylinder of the printing press, and (vi) the printing master is taken out of the plate cylinder (preferably by winding up with an uptake spool).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lithographic printing method, and more particularly, to an image forming material.
unwound from a supply roll, wrapped around a cylinder of a printing press, allowed it to be exposed in an image-wise fashion, and made it single-fluid
dink) to be processed.

[0002]

2. Description of the Related Art A lithographic printing press uses a so-called printing master, for example, a printing plate attached to a cylinder of a printing press. The master carries a lithographic image on its surface, and after supplying ink to the image, receives the ink from the master.
printed on a material (which is typically paper). In normal lithographic printing,
An aqueous fountain is added to the lithographic image which is composed of lipophilic (or hydrophobic, i.e., ink-repellent) areas plus hydrophilic (or oleophobic, i.e., water-repellent, ink-repellent) areas Ink is supplied in addition to a solution (also called a dampening liquid). In so-called driographic printing, the lithographic image consists of an ink receiving area and an ink absorptive (a
bhesive) area, and only ink is supplied to the master during driographic printing.

[0003] Print masters are commonly referred to as so-called computer-to-film.
m), in which the various pre-press steps, such as the selection of the type face, scanning, color separation, screening, trapping, layout and assembly, etc., are performed digitally. Achieved, and each of the selected colors is transferred to a graphic arts film on an image-setter. After processing the film, the film can be used as a mask when exposing an imaging material called a plate precursor, and processing the plate to obtain a printing plate, which is used as a master be able to.

In recent years, so-called computer-to-plate (CTP)
The method is gaining great interest. In this method (also called the direct-to-plate method), a digital document is used.
Is called a plate-setter.
The transfer of the film directly to the plate precursor in r) avoids the production of a film. A special type of CTP method is to transfer the plate precursor to the plate cylinder of the printing press.
with exposure to it by an image setting device that is integrally attached to the press. Such a method can be referred to as a "computer-to-press" method, and a printing press with an integrated platesetter is sometimes referred to as a digital press. Digital Press reviews Procee
dings of the Imaging Scie
nce &Technology's 1997 I
internationalConference on
Digital Printing Technology
ogy (Non-Impact Printing 1
It is shown in 3). Computer-to-press methods are described, for example, in EP-A-770495, EP-A-770-496, WO 940.
01280, EP-A-580 394
And EP-A-774 364. European Patent Application Publication No. 640 4
No. 78 includes supply rolls and uptake (uptak)
e) an automatic plate-loading system comprising a roll in a plate cylinder
m) is described.

[0005] A typical plate material used in the computer-to-press method is ablation.
n) is the base version. Ablative
The problem associated with the plate is that debris is formed, which is difficult to remove and disturbs the printing process or exposes the integrated image setting device to an exposure option.
ics). Other methods require wet processing with chemicals, which cause damage or contamination of the electronics and optics of the integrated image set-up and other equipment provided with the press. there is a possibility. Thus, the computer-to-press method, in particular, requires no wet treatment or can be treated with fresh water, ink or fountain, lithographic coating.
s) is desired. WO 900002044, WO
91008108 and EP-A-58
No. 0394 discloses such plates, however, because they are all ablative plates with a multilayer structure, they are not well suited for use in on-press coatings. . U.S. Pat. No. 6,095,048 discloses treating ablation-type materials with a single liquid ink.

[0006] Non-ablative plates that can be processed with fountains and inks
e) is described in EP 770 494. The latter patent describes exposing an image forming material comprising an image recording layer containing a hydrophilic binder, a compound capable of converting light to heat, and hydrophobic thermoplastic polymer particles in an imagewise manner. A method is disclosed for causing the exposed areas to thereby change to a hydrophobic phase, which defines the printing areas of the print master. Since the layer undergoes processing by interaction with the fountain and ink (which are fed to the cylinder during the pressing operation), the pressing operation can be started immediately after exposure without any additional processing. . In this way, the wet chemical treatment of the material is "invisible (h
iden) ", which is achieved during the first operation of the printing press.

[0007] A problem associated with the latter method is that the on-press process is carried out in a step of first supplying the fountain to the plate and then also supplying the ink, which step is easily carried out with a printing press. Can be implemented when the ink roller and the fountain roller can be engaged independently of each other. However,
It is more difficult to optimize the on-press process by adding the fountain and ink simultaneously, which is only an option for printing presses with an integrated ink / fountain supply.

In addition, in the case of a driographic press, it is not possible to treat the plate material used in such a press with a fountain, since only the ink is supplied to the plate. In the Doriographic press, the temperature also needs to be carefully controlled as there is no cooling effect of the aqueous fountain solution.

[0009]

Thus, there is a need for a method that enables on-press processing of an image forming material to be achieved without the supply of an aqueous fountain solution.

[0010]

SUMMARY OF THE INVENTION It is an object of the present invention to perform on-press processing in all lithographic printing presses (and also lithographic printing presses without fountain feed) with automatic plate filling and on-press exposure. To provide a lithographic printing method that enables A fully automatic printing method is obtained that allows all steps of plate filling, exposure and processing in such a method to be performed without human intervention.

This object is achieved by the method according to the first aspect. Using a single liquid ink, on-press processing of an image forming material comprising an image recording layer that is soluble in the single liquid ink or that can become soluble in said single liquid ink by an exposure step Then I found out that excellent results can be obtained. In general, a single liquid ink is understood to be an emulsion in which the ink phase is in the polar phase or vice versa. When a single liquid ink is used, printing can be performed using a normal wet lithographic printing master without using a wetting liquid. The ink phase is adsorbed on the hydrophobic areas of the print master and the polar phase wets the hydrophilic areas, preventing the components of the ink from being adsorbed on the non-printed portions of the lithographic image.

The printing method according to the present invention is a cycle of steps (i) to (vi) as defined in claim 1, and this cycle may be repeated several times.
A web of imaging material present on a supply roll (we
b) Depends on length. Print cycle (print
The number of cycles is preferably greater than 1, more preferably greater than 10, and most preferably greater than 30. Since plate exchange and filling are completely automatic,
Press downtime between print cycles is minimal.

Further objects of the present invention will become clear from the detailed description. Specific features of preferred embodiments of the invention are set out in the dependent claims.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The image forming material used in the present invention comprises a soft lithographic base and an image recording layer. Lithographic Substrate The lithographic substrate comprises a support in the form of a web that is soft enough to be wound on a spool. The support has a hydrophilic surface or is provided with a hydrophilic layer. The flexible support may be made of paper, plastic, thin metal such as aluminum, or a composite or laminate thereof, such as a laminate of plastic and metal. A very suitable example is a PET film laminated to aluminum that is thin enough to be wound on a spool. Preferable examples of the plastic film include a polyethylene terephthalate (PET) film, a polyethylene naphthalate film, a cellulose acetate film, a polystyrene film, a polycarbonate film and the like. The support, which is a plastic film, may be opaque or transparent.

[0015] Particularly suitable lithographic substrates having a hydrophilic surface are subjected to electrochemical granulation.
An aluminum support that is chemically grained and anodized. The anodized aluminum support may be subjected to a treatment to improve the hydrophilicity of its surface. For example, by subjecting the surface of an aluminum support to treatment with a sodium silicate solution at an elevated temperature, for example, 95 ° C., the surface thereof is subjected to a silicon treatment (sil).
icated). Alternatively, it is possible to use a phosphating treatment which involves subjecting the aluminum oxide surface to a treatment with a phosphate solution (which may also contain an inorganic fluoride). Furthermore, it is possible to rinse the aluminum oxide surface with a citric acid or citrate solution. Such treatment can be performed at room temperature or at a slightly elevated temperature of about 30 to 50 ° C.
A further treatment of interest is that which involves rinsing the aluminum oxide surface with a bicarbonate solution. Furthermore, polyvinyl phosphonic acid on the aluminum oxide surface,
It may be subjected to treatment with polyvinyl methylphosphonic acid, polyvinyl alcohol phosphate, polyvinyl sulfonic acid, polyvinyl benzene sulfonic acid, polyvinyl alcohol sulfate, and polyvinyl alcohol acetal (formed by reaction with sulfonated fatty aldehyde). It is possible. Further, it is clear that one or more of such post-treatments may be performed alone or in combination. A more detailed description of such a process is given in GB-A-1 084 070, DE-A-4 423 140, DE-A-4417 907, EP-A-6.
No. 59909, EP-A-5376.
No. 33, German Patent Application No. 4 001 466,
EP-A-292 801; EP-A-291 760 and U.S. Pat.
No. 458 005.

In the case of a support having no hydrophilic surface, it may be provided with a hydrophilic layer (called a base layer). Such a base layer preferably comprises a hydrophilic binder.
A curing agent such as formaldehyde, glyoxal,
It is a crosslinked hydrophilic layer obtained by crosslinking with a polyisocyanate or a hydrolyzate of tetra-alkyl orthosilicate. The latter is particularly preferred. The thickness of such a hydrophilic base layer can vary from 0.2 to 25 μm, but is preferably 1 or 10 μm.

Suitable hydrophilic binders for use in such base layers are, for example, hydrophilic (co) polymers, such as vinyl alcohol, acrylamide, methylolacrylamide, methylolmethacrylamide, acrylic acid, methacrylic acid, acrylic acid Homopolymers and copolymers made from hydroxyethyl, hydroxyethyl methacrylate, and the like, or maleic anhydride / vinyl methyl ether copolymer. The hydrophilicity of the (co) polymer or (co) polymer mixture used is preferably such that polyvinyl acetate is hydrolyzed to a degree of at least 60% by weight, preferably 80% by weight. Same or higher than the indicated hydrophilicity.

Preferably, the amount of curing agent, especially tetraalkyl orthosilicate, is at least 0.2 part by weight, more preferably 0.5 to 5 parts by weight, most preferably 1 part by weight per part by weight of hydrophilic binder. Parts to 3 parts by weight.

Such a hydrophilic base layer can also contain substances which increase the mechanical strength and the porosity of this layer. Colloidal silica may be used for this purpose. The colloidal silica used may be in the form of any commercially available aqueous dispersion containing, for example, colloidal silica having an average particle size of 40 nm or less, for example, 20 nm. In addition, inert particles larger than the size of such colloidal silica, such as Stover, are described in J. Am. Colloid and Interface S
ci. 26, 1968, 62-69, or alumina particles or particles of titanium dioxide or other heavy metal oxides having an average diameter of at least 100 nm. is there. Incorporation of such particles on the surface of the hydrophilic base layer results in a uniform and rough texture composed of microscopic hills and valleys, which acts as a reservoir for water in the background area.

A specific example of a hydrophilic base layer suitable for use in accordance with the present invention is described in EP-A-601 24.
No. 0, British Patent No. 1 419 512, French Patent No. 2300 354, U.S. Pat. No. 3,971 660
And U.S. Pat. No. 4,284,705.

An adhesion improving layer (adhesion impr)
oving layer) [this is also the subbing layer (s
It is particularly preferred to use a film support which has been provided with a film support. Particularly suitable adhesion-enhancing layers for use in accordance with the invention are EP-A-619 524, EP-A-620 502 and EP-A-61.
No. 9525, a layer comprising a hydrophilic binder and colloidal silica. The amount of silica in the adhesion improving layer is preferably from 200 mg / m ² to 750 mg /
m ² range. Further, the ratio of silica to hydrophilic binder is preferably greater than 1 and the surface area of the colloidal silica is preferably at least 300 m ² / gram, more preferably at least 500 m ² / gram. Image forming material The image forming material comprises at least one image recording layer, which is located on the lithographic substrate. Preferably, there is only one layer located on the substrate. This material may be light or heat sensitive, but the latter is preferred because it is more stable in daylight. The image recording layer of the material used in the present invention is preferably non-ablative. The term “non-ablative” is understood as meaning that the image-recording layer is not substantially removed during the exposure phase. This material is positive-wo
The exposed surface of the image recording layer can be removed with the single liquid ink, so that the hydrophilic surface of the lithographic substrate (which reduces the non-printed area of the master). Limit) appears, while the unexposed areas are not removable with the single-part ink, which limits the hydrophobic print area of the master. In a more preferred embodiment, the material is negative-working, ie, the non-exposed areas of the image recording layer are removed with the single liquid ink to reduce the hydrophilic surface of the lithographic substrate (which defines the non-printed areas of the master). While appearing, the exposed areas are not removable with the single-part ink, which limits the hydrophobic printing area of the master. The term "removable" refers to the removal of the image recording layer from the lithographic substrate upon supply of the single liquid ink, for example, the layer dissolves in the single liquid ink or the layer enters the single liquid ink. Indicates that a dispersion or emulsion can be formed and removed.

In a preferred embodiment, the image forming material is negative-working, comprising an image recording layer that is removable with the single liquid ink before exposure but is not removable after exposure. Here, two very preferable embodiments of such a negative image recording layer will be considered.

The mechanism of action of the image forming layer in the first very preferred embodiment is, for example, EP 770 494, EP
770 495, EP 770 497, EP 77
3112, EP 774 364 and EP 849
090, relies on heat-induced coalescence of hydrophobic thermoplastic polymer particles (preferably dispersed in a hydrophilic binder). The coalesced polymer particles define a hydrophobic print area, which is not easily removed with the single-part ink, while the unexposed layer is easily removable with the single-part ink, and Limit the area. Such thermal coalescence can be induced by direct exposure to heat, for example, a thermal head (the
This can be triggered by using rmal head) or by absorbing the light with one or more compounds capable of converting light, more preferably infrared light into heat. Particularly useful compounds that convert light into heat are, for example, dyes, pigments, carbon black, metal carbides, borides, nitrides, carbonitrides,
Bronze-structured oxides and conductive polymer dispersions such as polypyrrole, polyaniline or polythiophene-based conductive polymer dispersions. Infrared dyes and carbon black are very suitable.

The temperature at which such hydrophobic thermoplastic polymer particles coalesce is preferably above 35 ° C., more preferably above 50 ° C. Solidification can also occur as a result of the thermoplastic polymer particles softening or melting under the influence of heat. There is no particular upper limit on the temperature at which such hydrophobic thermoplastic polymer particles coalesce; however, this temperature must be significantly lower than the decomposition temperature of the polymer particles. The temperature at which the coagulation takes place is preferably at least 10 ° C. lower than the temperature at which the decomposition of the polymer particles takes place. Specific examples of the hydrophobic polymer particles include, for example, polyethylene, polyvinyl chloride, poly (meth) acrylate, poly (meth) acrylate, polyvinylidene chloride, polyacrylonitrile, polyvinylcarbazole, polystyrene, and copolymers thereof. It is. Most preferably, polystyrene is used. The weight average molecular weight of such a polymer is 5,000
To 1,000,000 g / mol. The particle size given to such hydrophobic particles is 0.1.
It may range from 01 μm to 50 μm, more preferably 0.05 μm to 10 μm, most preferably 0.05 μm to 2 μm. The amount of such hydrophobic thermoplastic polymer particles included in the imaging layer is preferably from 20% by weight to 6%.
5% by weight, more preferably 25% to 55% by weight, most preferably 30% to 45% by weight.

Suitable hydrophilic binders include, for example, synthetic homo or copolymers such as polyvinyl alcohol, poly (meth) acrylic acid, poly (meth) acrylamide, hydroxyethyl poly (meth) acrylate, polyvinyl methyl ether, etc. Or natural binders such as gelatin, polysaccharides such as dextran, pullulan, cellulose, gum arabic, alginic acid and the like.

In a very preferred second embodiment, the image-forming layer is hydrophilic prior to exposure and is soluble in the single-part ink but becomes hydrophobic and insoluble after exposure to aryldiazosulfonate homo or This is a layer containing a copolymer. This exposure can be performed by the same means discussed above in connection with the thermal coalescence of the polymer particles. Alternatively, the conversion of the aryldiazosulfonate polymer may be carried out by ultraviolet light, such as UV laser or U.
It is also possible to carry out by exposure to a V lamp.

A preferred example of such an aryldiazosulfonate polymer is to homopolymerize an aryldiazosulfonate monomer or convert it to another aryldiazosulfonate monomer and / or a vinyl monomer such as ( (Meth) acrylic acid or its ester, (meth)
A compound that can be produced by copolymerizing with acrylamide, acrylonitrile, vinyl acetate, vinyl chloride, vinylidene chloride, styrene, α-methylstyrene, and the like. Aryldiazosulfonate polymers suitable for use in the present invention have the formula:

[0028]

Embedded image

Wherein R ⁰ , ¹ and ² are each independently hydrogen, an alkyl group, a nitrile or a halogen such as Cl
And L represents a divalent linking group, and n represents 0 or 1.
A represents an aryl group and M represents a cation. L is, preferably, -X _t -CONR
_{^{3 -, - X t -COO -}} , - X- and -X _t -CO-
(Where t represents 0 or 1, R ³ represents hydrogen, an alkyl group or an aryl group, X represents an alkylene group, an arylene group, an alkyleneoxy group, an aryleneoxy group,
A divalent linking group selected from the group consisting of an alkylenethio group, an arylenethio group, an alkyleneamino group, an aryleneamino group, oxygen, sulfur and an amino group. A is preferably an unsubstituted aryl group, such as an unsubstituted phenyl group, or an aryl group substituted with one or more alkyl, aryl, alkoxy, aryloxy or amino groups. ,
For example, it represents phenyl. M preferably represents a cation such as NH ₄ ⁺ or a metal ion such as a cation of Al, Cu, Zn, alkaline earth metal or alkali metal.

Aryldiazosulfonate monomers suitable for use in forming the above-mentioned polymers are described in EP-A-339393, EP-A-507008 and EP-A-7.
No. 71645. Specific examples are as follows:

[0031]

Embedded image

[0032]

Embedded image

[0033]

Embedded image

[0034]

Embedded image

The image forming material may include other layers in addition to the image recording layer, which are also located on the lithographic substrate. The light absorbing compound is present in another layer located near the layer containing the other materials listed above, such as hydrophobic thermoplastic polymer particles and aryldiazosulfonate polymer. Is also good. Alternatively, a protective top layer (protect) is formed on the image forming material.
an active top layer, such a protective top layer is a layer that provides protection against handling or mechanical damage, which is removable with the single-part ink. A suitable protective top layer is a layer comprising polyvinyl alcohol. Single Liquid Inks Single liquid inks suitable for use in the method of the present invention are described in U.S. Patent Nos. 4,045,232 and 4,981,5.
No. 17 and US Pat. No. 6,140,392. In general, a single liquid ink is understood to be an emulsion in which the ink phase is in the polar phase or vice versa. The ink phase is also called a hydrophobic or lipophilic phase. The polar phase preferably comprises at least 50%, more preferably at least 70%, even more preferably at least 90% of a non-aqueous polar liquid. In the most preferred embodiment, the polar phase is comprised of a polar organic liquid and is essentially free of water. Such a polar liquid is preferably a polyol. A very suitable single liquid ink is WO 00 /
32705, the relevant content of which is reproduced herein below.

The hydrophobic phase preferably comprises a carboxyl-functional vinyl resin. The term "vinyl resin"
Include polymers produced by chain reaction polymerization or addition polymerization with a carbon-carbon double bond using a vinyl monomer and a monomer copolymerizable with the vinyl monomer. Typical vinyl monomers include, but are not limited to, vinyl esters, acrylic and methacrylic monomers, and vinyl aromatic monomers, including styrene. The vinyl polymer can be branched by including a monomer having two reaction sites in the polymerization reaction. When branching this vinyl polymer,
Still so that it remains effectively soluble.
"Soluble" means that the polymer can be diluted with one or more solvents [in contrast, when the polymer is crosslinked to give an insoluble three-dimensional network structure, Such structures only swell with solvent].
Such branched vinyl resins remain dilutable with solvents despite having a significant number of branches.

By polymerizing a monomer mixture containing at least one acid-functional monomer or at least one monomer having a group that changes to an acid group after polymerization, such as an anhydride group, A vinyl polymer having a carboxyl function can be produced. Examples of monomers having acid functionality or anhydride functionality include, but are not limited to, α, β-ethylenically unsaturated monocarboxylic acids having 3 to 5 carbon atoms, such as acrylic acid, methacrylic acid. Α, having 4 to 6 carbon atoms, such as acids and crotonic acids,
β-ethylenically unsaturated dicarboxylic acids and anhydrides and monoesters of such acids, such as maleic anhydride and fumaric acid, and acid-functional derivatives of copolymerizable monomers, such as hydroxyethyl acrylate or succinic acid And the like.

Include acid-functional monomers such as acrylic acid, methacrylic acid or crotonic acid, or anhydride monomers which can produce acid groups by hydrolysis after polymerization, such as maleic anhydride or itaconic anhydride. Is preferred.
Non-volatile weight of acid-functional vinyl polymer (nonvolat)
acid value based on ile weight) is non-volatile 1
At least about 3 mg KOH per gram, preferably about 6 to about 30 mg KO per gram non-volatile
H, more preferably acid-functional vinyl polymers having an acid number of about 8 to about 25 mg KOH per gram of non-volatiles.

The acid-functional polymer in a preferred embodiment is a significantly branched polymer. In the ink used in the present invention,
Preferably, it contains a branched but effectively soluble vinyl polymer. Such branched vinyl polymers can be diluted rather than swelled when a solvent is added thereto. Such branching can be achieved in at least two ways: In the first method, a monomer having two or more polymerizable double bonds is included in a polymerization reaction. In the second method, a pair of ethylenically unsaturated groups each having, in addition to the polymerizable double bond, at least one additional functionality that is reactive to the additional functionality of the other monomer. Saturated monomers are included in the monomer mixture to be polymerized. Preferably, the reaction of such additional functional groups occurs during the polymerization reaction, but this is not considered critical and some or all of the reaction of such additional functional groups may be performed before or after polymerization. It is also possible to wake up. Such pairs of interactive groups may be present in a variety of ways. Illustrative examples of such paired reactive groups include:
Although not limited to these, epoxide and carboxyl group, amine and carboxyl group, epoxide and amine group, epoxide and anhydride group, amine and anhydride group, hydroxyl and carboxyl or anhydride group, amine and acid chloride group, alkylene -Imine and carboxyl group, organic alkoxysilane and carboxyl group, isocyanate and hydroxyl group, cyclic carbonate and amine group, isocyanate and amine group, and the like. If a carboxyl or anhydride group is included as one such reactive group, it is used in an excess sufficient to allow the vinyl resin to have the required carboxyl functionality. Specific examples of such monomers include, but are not limited to,
Glycidyl (meth) acrylate and (meth) acrylic acid,
Includes N-alkoxymethylated acrylamide, which reacts with itself, such as N-isobutoxymethylated acrylamide, gamma-methacryloxy trialkoxysilane, which reacts with itself, and combinations thereof.

The polymerization of such a vinyl resin is preferably carried out with at least one polymer having two or more polymerizable ethylenically unsaturated bonds, particularly preferably two to about four polymerizable ethylenically unsaturated bonds. This is performed using a monomer. Illustrative examples of monomers having two or more ethylenically unsaturated moieties include, but are not limited to, (meth) acrylates of polyols, such as di (meth) acryl of 1,4-butanediol. Acid ester, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, tetramethylolmethane tetra (meth) acrylate Acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate
Acrylates, di (meth) acrylates of alkylene glycols and di (meth) acrylates of polyalkylene glycols, such as di (meth) acrylates of ethylene glycol, di (meth) acrylates of butylene glycol, Divinyl benzene, allyl methacrylate, such as di (meth) acrylate of diethylene glycol, di (meth) acrylate of triethylene glycol, and di (meth) acrylate of polyethylene glycol;
Includes diallyl phthalate, diallyl terephthalate and the like, which can be used alone or in combination of two or more. Among them, divinylbenzene, dimethacrylate of butylene glycol, dimethacrylate of butanediol, triacrylate of trimethylolpropane and tetraacrylate of pentaerythritol are very preferred, and divinylbenzene is even more highly preferred. It is suitable for.

In the polymerization of such a branched vinyl polymer,
Preferably, at least two polymerizable ethylenically unsaturated bonds are present.
At least about 0.008 equivalents per 100 grams of monomers to be polymerized, or at least one monomer having two reactive groups in addition to the polymerizable ethylenically unsaturated bond. Is used in an amount of 0.004 equivalent per 100 g of the monomer to be polymerized. In the polymerization of such a branched vinyl polymer, one or more polyfunctional monomers having at least two polymerizable ethylenically unsaturated bonds or one polymerizable bond is preferably added. From about 0.012 to about 0.08 per 100 grams of monomer to be polymerized.
Equivalents, more preferably about 0.016 to about 0.064 equivalents are used.

The number of polymerizable ethylenically unsaturated bonds of one or more such polyfunctional monomers is preferably 2 to 4, more preferably the number of polymerizable ethylenically unsaturated bonds is 2. In one embodiment, from about 0.5% to about 6%, more preferably from about 1.2% to about 6%, and even more preferably from about 0.5% to about 6%, based on the total weight of the monomers from which divinylbenzene is polymerized. 1.2% to about 4%, even more preferably about 1.
It is preferred to polymerize a monomer mixture containing from 5% to about 3.25% to produce a branched vinyl resin [commercial grade divinylbenzene is a monofunctional material and / or Contains materials that do not have. In the case of such commercial materials, it is necessary to calculate the amount required to obtain said percentage. For example, in the case of a material having 80% by weight of divinylbenzene and 20% by weight of a monofunctional monomer, 5% by weight of this material means that the fraction of divinylbenzene is 4% by weight].

The polymerization mixture contains (1) divinylbenzene or another monomer having at least two polymerizable ethylenically unsaturated bonds or (2) a pair of monomers having a polymerizable group and an additional interactive group. The optimum amount of monomer is, to some extent, based on individual reaction conditions, such as the rate of addition of the monomer added during polymerization, the solubility of the resulting polymer in the selected reaction medium, and the reaction medium. Depends on the amount of monomer selected, the half-life of the initiator selected at the reaction temperature, and the amount of initiator relative to the weight of the monomer, which can be determined by simple tests.

Other monomers that may 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: Although not limited to these, α, having 3 to 5 carbon atoms,
Esters of β-ethylenically unsaturated monocarboxylic acids, such as esters of acrylic acid, methacrylic acid and crotonic acid, α, β-ethylenically unsaturated dicarboxylic acids having 4 to 6 carbon atoms and of such acids. Includes anhydrides, monoesters and diesters, vinyl esters, vinyl ethers, vinyl ketones, and aromatic or heterocyclic aliphatic vinyl compounds. Representative examples of suitable acrylates, methacrylates, and crotonic esters include, but are not limited to, the reaction of the acid with saturated aliphatic and cycloaliphatic alcohols having 1 to 20 carbon atoms. The resulting esters such as methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, t-butyl, 2-ethylhexyl, lauryl, stearyl, cyclohexyl, trimethylcyclohexyl, tetrahydrofurfuryl, stearyl, sulfoethyl and isobornyl acrylate, methacrylate And crotonates, and acrylates and methacrylates of polyalkylene glycols. Representative examples of other polymerizable ethylenically unsaturated monomers include:
Anhydrides of fumaric acid, maleic acid and itaconic acid, including but not limited to monoesters and diesters made from alcohols such as methanol, ethanol, propanol, isopropanol, butanol, isobutanol and t-butanol And the like. Representative examples of polymerizable vinyl monomers include, but are not limited to, vinyl acetate,
Included are compounds such as vinyl propionate, vinyl ethers such as vinyl ethyl ether, vinyl halides and vinylidene halides, and vinyl ethyl ketone. Representative examples of aromatic or heterocyclic aliphatic vinyl compounds include, but are not limited to, compounds such as styrene, α-methylstyrene, vinyltoluene, t-butylstyrene, and 2-vinylpyrrolidone. The selection of such a monomer is determined by the ink varnish (in
k varnishes), based on various factors that are normally considered when producing the ink composition, including such factors as the desired glass transition temperature of the resulting polymer and the solvent of the ink composition. Or the desired dilutability in the solvent system
ty).

The preparation of suitable vinyl polymers can be carried out using conventional techniques, and is preferably semi-batch (semi)
-Batch) method. For example, in a semi-batch method, a suitable reaction vessel may be charged with a solvent, heated and fed with monomer, one or more initiators, and any chain transfer agent at a controlled feed rate. Typical sources of free radicals are organic peroxides, such peroxides such as dialkyl peroxides such as di-t-butyl peroxide and dicumyl peroxide, such as peroxides. Diacyls such as peroxycarbonates and peroxydicarbonates, such as t-butyl octylate and t-butyl perpivalate, e.g., t-butylperoxyisopropyl carbonate, di-2-ethylhexylperoxydicarbonate and dicyclohexylperoxydicarbonate. Hydroperoxides such as peroxides, such as dibenzoyl peroxide and dilauroyl peroxide; ketone peroxides, such as cumene hydroperoxide and t-butyl hydroperoxide S, for example, cyclohexanone peroxide and methyl isobutyl ketone peroxide, and peroxy ketals, such as 1,1-bis (t-butylperoxy) -
3,5,5-trimethylcyclohexane and 1,1-
Not only bis (t-butylperoxy) cyclohexane and the like, but also azo compounds such as 2,2′-azobis (2
-Methylbutanenitrile), 2,2'-azobis (2-
Methyl) propionitrile and 1,1′-azobis (cyclohexanecarbonitrile). Organic peroxides are preferred. Particularly, t-butyl peroxyisopropyl carbonate is preferred. It is also possible to use chain transfer agents in the polymerization. Typical chain transfer agents are mercaptans, such as octyl mercaptan,
thiosalicylic acid, mercaptocarboxylic acids, such as mercaptoacetic acid and mercaptopropionic acid, such as n- or t-dodecylmercaptan, and esters thereof; and mercaptoethanol, halogen-substituted compounds, and dimers of α-methylstyrene. Preferably, no chain transfer agent is included, since its inclusion causes odor 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.
From about 300 ° C, preferably from about 150 ° C to about 200 ° C,
More preferably, it is carried out in a solution at a temperature of from about 160 ° C to about 165 ° C. The polymerization is preferably carried out at about the same reaction temperature using the same initiator or initiators throughout. The choice of the initiator should be such that it exhibits a half-life at the reaction temperature of preferably only about 30 minutes, particularly preferably only about 5 minutes and even more preferably only about 2 minutes. Particularly preferred are initiators that exhibit a half-life of less than about 1 minute at a temperature of about 150 ° C to about 200 ° C. In general, the shorter the half-life of the initiator and / or the higher the amount of initiator used, the greater the possibility of incorporating the branching monomer. When such vinyl polymer vehicles are used in inks, they preferably have little or no residual (unreacted) monomer. Particularly preferably, such a vinyl medium is substantially free of residual monomers, i.e., the amount of residual monomers is about 0.5 to about 0.5% based on the total weight of polymerized monomers. %, Even more preferably the amount of residual monomer is less than about 0.1% by weight.

In the semi-batch process, the monomers and initiator are added to the polymerization reactor over a period of time, preferably at a constant addition rate. This addition time is typically from about 1 to about 10 hours, with addition times of about 3 to about 5 hours being typical. Typically, the longer the addition time, the lower the number average molecular weight. The number average molecular weight can also be reduced by increasing the solvent to monomer ratio or by using a strong solvent for the resulting polymer.

When a branched vinyl polymer is used in an ink
In general, the polymer generally has a low number average molecular weight and a wide
Shows high polydispersity
To do. Number average molecule of vinyl resin used in this ink
Weight and weight average molecular weight are well accepted
According to the polystyrene standards (this is a 6 million weight average
Gel permeation chromatograph using
It can be measured by torography. Polydispersity is M_w/ M_nof
Defined as a ratio. Vinyl polymerization in a preferred embodiment
Number average molecular weight (M_n) Is at least about 1000
More preferably, it is at least about 2000. Also, the number average
The molecular weight is also preferably less than about 15,000, more preferably about
Less than 10,000, even more preferably less than about 8500
is there. M _nA preferred range is from about 1000 to about 10,000
0 and M_nA more preferred range is from about 2000 to about 8
500, and an even more preferred range is from about 4000 to about
8000. The weight average molecular weight is at least about 30,
000, preferably at least about 100,000
Must. Weight average molecular weight (M_w) Is preferably heavy
GPC using available standards with a weight average molecular weight of 6 million
Less than about 60 million based on measurements. M_wSuitable range of
Is from about 30,000 to about 55 million, and M_wBetter than
A suitable range is from about 100,000 to about 1 million, and even more.
A more preferred range is from about 100,000 to about 300,000.
It is. M_wRanges from about 100,000 to about 300,
000, preferably a very high molecular weight (about 45
(Over 10,000) Shoulder (can be confirmed by GPC)
Avoid using the indicated resins. This polydispersity, M_w/ M_n
Is about 10,000 or less, preferably about 1000 or less
It may be. This polydispersity is preferably at least about
15, particularly preferably at least 50.
This polydispersity preferably ranges from about 15 to about 1000
And more preferably in the range of about 50 to about 800
To enter.

The theoretical glass transition temperature can be adjusted through the selection and ratio of copolymerizing monomers, according to methods well known in the art. In a preferred embodiment, the theoretical T
_g is above room temperature, preferably the theoretical T _g is at least 60 ° C, more preferably at least 70 ° C. Preferably, in the methods and compositions of the present invention, the T _g is from about 50 ° C. to about 125 ° C., more preferably about 6 ° C.
A vinyl polymer at 0 ° C. to about 100 ° C., even more preferably about 70 ° C. to about 90 ° C. is used.

In one embodiment of the single-part ink, an acid-functional vinyl polymer, which may be a branched vinyl polymer, is combined with other resins included in the ink composition.
Examples of other suitable resins that can be combined with the acid-functional vinyl polymer include, but are not limited to, polyester and alkyd resins, phenolic resins, rosin,
Cellulosics and their derivatives, such as rosin-modified phenolic resins (phen)
lics), phenol-modified rosin, hydrocarbon-modified rosin, maleic acid-modified rosin, fumaric acid-modified rosin, etc., hydrocarbon resins and other acrylics
Alternatively, a vinyl resin, a polyamide resin, or the like is included.
Such resins or polymers may be included in amounts from about 1 part to about 6 parts by weight of the acid-functional vinyl polymer, based on the non-volatile weight of such resins.

The ink composition preferably contains at least one solvent in addition to the acid-functional vinyl resin and the optional second resin. In a preferred embodiment of the single liquid ink, a solvent 1 containing the branched vinyl resin in the ink formulation is used.
Either in the seed or in two or more to produce a solution or to produce an apparently cloudy apparent solution. The particular solvent and amount of solvent to include is determined by the desired ink viscosity, body, and tack. If one or more solvents are used in the ink that may come into contact with rubber parts, such as rubber rollers, during lithographic processing, generally, such rubbers are not affected,
Not oxidized (non-oxygenate
d) One or more solvents exhibiting low Kauri-butanol (KB) values are used. Solvents suitable for use in inks that may come into contact with rubber parts include, but are not limited to, aliphatic hydrocarbons, such as petroleum fractions and normal and isoparaffinic solvents exhibiting limited aroma properties. And so on. For example, petroleum middle distillates such as Pennsylvania Refinin
g Company (Franklin Park, I
ll. ), A subsidiary of Magie Bros. Oil
A fraction available from the Company under the trademark Magie Sol, Exxon Chemical Co.
(Houston, Tex) Trademark ExxPrint
Fractions available under the Golden Bear
Oil Specialties (Oildale,
Calif. ), Total Petroleum I
nc. (Denver, Colo.) And Calum.
et Lubricants Co. (Indiana
polis, Ind. ) May be used. Additionally or alternatively, soybean oil or other vegetable oils can be included.

When a solvent which has not undergone such oxidation is used, generally at least one of the solvents having a substantial affinity for the aliphatic solvent is used in order to obtain the desired solubility of the suitable branched vinyl polymer. Must be included in a sufficient amount. For this purpose, generally, the monomer to be polymerized is an acrylate ester monomer (having at least 6 carbon atoms in the alcohol portion of the ester) or styrene or an alkyl-substituted styrene such as t-butylstyrene. May be included. In a preferred embodiment, a monomer that promotes the solubility of an aliphatic, such as stearyl methacrylate or t-butylstyrene (such as stearyl methacrylate, etc.) is added to an ink composition using a solvent that has not undergone oxidation. Is a preferred monomer) of at least about 20
%, Preferably about 20% to about 40%, more preferably about 2%.
It contains a branched vinyl resin polymerized from a monomer mixture containing from 0% to about 25%. It is also preferred to include at least 55% styrene, preferably about 55% to about 80% styrene, more preferably about 6% styrene.
Include from 0% to about 70%. Also, if desired, solvent tolerable amounts for aliphatic solvents (solvent to
It is also possible to use methyl methacrylate or other monomers for the purpose of lowering the lance. All percentages are weight percentages based on the total weight of the monomer mixture to be polymerized. Suitable monomer compositions for vinyl polymers used in lithographic inks include, among others, (meth) acrylates made from alcohols having 8-20 carbon atoms, such as stearyl methacrylate, styrene and divinylbenzene. And (meth) acrylic acid. In a preferred embodiment, the number of carbon atoms is 8-2.
About 15, preferably about 20 to about 30, preferably about 25, weight percent of a (meth) acrylate ester, especially stearyl methacrylate, made from 0 alcohols, and a styrenic monomer Body, especially styrene itself, in an amount of from about 50, preferably from about 60 to about 80, preferably about 75, percent by weight of divinylbenzene as indicated above, acrylic acid or more preferably Acrylic acid is added to about 0.
5, preferably from about 2.5 weight percent to about 5, preferably about 4 weight percent, to produce a branched vinyl polymer suitable for use in lithographic inks.

The boiling point of such a solvent or mixture of solvents is preferably at least about 100 ° C. to preferably about 55 ° C.
Keep below 0 ° C. In the offset printing ink, a solvent having a boiling point exceeding about 200 ° C. may be used. Newsprint inks are typically formulated using from about 20 to about 85 weight percent of a solvent such as mineral oil, vegetable oil and high boiling petroleum fraction. The amount of the solvent will also depend on the type of ink composition (i.e., whether the ink is for newspaper, heat setting, sheetfed, etc.), the particular solvent used, and other known in the art. Depends on the factors. In the case of lithographic inks, the solvent content is typically less than about 60% and oil is added to the solvent package (s).
The information may be included as a part of an event package. Lithographic inks generally contain at least about 35 solvents.
% To be present. When the varnishes or media (including branched vinyl resins) are used in the formulation of a suitable single-part ink composition, they are typically clear and apparently a solution.

In general, a pigment is added to such an ink composition.
More than one species is contained. The number and type of pigments will depend on the type of ink to be formulated. The pigments included in newspaper ink compositions are typically only one type or only a few types, such as carbon black, but the pigments included in gravure inks can be more complex pigment packages and have special effects. Color, for example, pearlescent
and any number of colors, including colors exhibiting metallic or metallic effects. Lithographic inks are typically used as four colors, magenta, yellow, black and cyan, but can also be formulated to achieve a pearlescent or metallic effect. In the ink composition of the present invention, any of ordinary inorganic and organic pigments can be used. Alternatively, the composition can be used as a top lacquer or varnish. Overlay lacquers (air dried) or varnishes (cured) are intended to be clear or transparent and thus do not include opaque pigments.

The lithographic ink composition used in the present invention is preferably a single liquid ink having a continuous phase based on an oil containing the acid-functional vinyl medium and a discontinuous polyol phase containing a liquid polyol. It is compounded as. The vinyl polymer phase is relatively stable to the polyol phase. Such stability is such that the two phases do not separate in the fountain. However, while the ink is being applied, the emulsion breaks and the polyol comes to the surface, moistening the plate areas that do not accept the ink. Inks that are stable in the fountain but break quickly and separate on the plate are toning
Even without g) it gives clean prints and shows consistent transfer properties. Appropriate stability may also depend on the particular acid-functional vinyl polymer and the particular polyol selected. The acid value and molecular weight may be adjusted to obtain the desired stability.

The higher the acid number of the vinyl resin, the less it can be used, but the acid number must not be excessively high, or such vinyl polymers may be made of hydrocarbons. It will not show sufficient solubility in the solvent. It is believed that the higher the acid number of the acid-functional vinyl resin, the less generally such resin will penetrate into the hydrophobic phase.

Polyethylene glycol oligomers such as diethylene glycol, triethylene glycol and tetraethylene glycol as well as ethylene glycol, propylene glycol and dipropylene glycol are examples of liquid polyols suitable for the polyol phase of the single liquid ink used in the present invention. It is an example. Of course, it is also possible to include in the polyol phase a mixture of various liquid polyols. Generally, a polyol having a higher molecular weight is used as the acid value of the vinyl polymer or acrylic polymer used is lower. Additional materials can be included in the polyol phase. A weak acid, such as citric acid, tartaric acid or tannic acid, or a weak base, such as triethanolamine, may be included in an amount from about 0.01 weight percent to about 2 weight percent or less of the ink composition. To help protect the plate and extend the life of the plate, certain salts, such as magnesium nitrate, may be used in an amount of from about 0.01% to about 0.5% by weight, preferably about 0.5% by weight, based on the weight of the ink composition. 0.
08 to about 1.5 weight percent.
Wetting agent to help wet the plate
t), for example, polyvinylpyrrolidone or the like may be added. When the polyvinylpyrrolidone is included, it is included in an amount from about 0.5 weight percent to about 1.5 weight percent, based on the weight of the ink composition.

The polyol phase may comprise from about 5% to about 50%, preferably about 10% by weight, based on the total weight of the ink composition.
Single-part inks may be formulated using from about 20% to about 35% by weight, particularly preferably from about 20% to about 30% by weight.
In the absence of a separate cooling means, the amount of polyol included in the ink composition is preferably sufficient to maintain a low temperature at which the plate can work. The amount of polyol phase required to achieve good toning and printing results depends on the type of plate used, but can be determined by simple tests. Water may be included in the polyol phase mixture in an amount up to about 4 or 5% by weight to aid in dissolving or homogenizing the materials included in such a polyol phase.

Those skilled in the art will recognize that other additives known in the art may be included in the ink compositions used in the present invention unless such additives greatly reduce the advantages of the present invention. You will understand what is good. Typical examples thereof include, but are not limited to, pour point depressants, surfactants, wetting agents, waxes, emulsifiers and dispersants, defoamers, antioxidants, UV absorbers, desiccants. Glidants and other rheological rheology modifiers, gloss improvers and anti-settling agents are included (for example, if the formulation contains vegetable oils). When additives are included, their content will typically be at least about 0.001% of the ink composition, and it may be up to about 7% by weight or more of the ink composition. Supply Roll The material is automatically fed to the cylinder of a printing press by unwinding the imaging material from a supply spool or supply roll, ie, by rewinding the web of imaging material wound on the supply spool. The unwound imaging material is wrapped around a press cylinder, which is preferably a plate cylinder that holds the print master during printing. Said supply roll is preferably located in a plate cylinder as described in EP-A-640 478. Alternatively, the supply roll can be located outside the cylinder, in which case the unwound material is wrapped around the cylinder and is preferably automatically wound off of the web wound on the supply roll. Cut out. After printing, the used material is wound up, preferably on an uptake roll or spool, which is also preferably integrated into a cylinder. The technical details of a preferred embodiment of such an integral supply roll and uptake roll as well as the associated drive and tension adjustment mechanisms are described in EP-A-6 620.
No. 40 478. Exposure Step The imaging material used in the present invention is exposed on-press to heat or light, i.e., the material is mounted on a cylinder of a press, preferably a plate cylinder that holds a print master during printing. Exposed. The exposure can be performed by, for example, a thermal head, an LED or a laser head. Preferably, one or more lasers, for example He / Ne
A laser, an Ar laser, a violet laser diode, or the like is used. Most preferably, the light used in this exposure is light that is not visible, such as ultraviolet (laser) light, so that daylight stable materials can be used, or has a wavelength of about 700 to about 1500 nm. A laser emitting near-infrared light in the range of, for example, a semiconductor laser diode, an Nd: YAG or Nd: YLF laser, or the like is used. The required laser power is determined by the sensitivity of the image recording layer and the pixel dwell time of the laser beam.
ll time) [this is the spot diameter (typical value of a modern platesetter with a maximum intensity of 1 / e ² : 10
-25 μm)], scan speed and resolution of the exposure device [ie, the number of addressable pixels per linear distance unit (often expressed in dots per inch or dpi); Value: 1000-4
000 dpi]. More technical details of on-press exposure equipment are described, for example, in US Pat. Nos. 5,174,205 and 5,163,368. Processing Step The processing of the image recording layer after exposure is preferably performed by an inking roller provided in a press.
ers) (which supplies the ink to the plate cylinder). Preferably, the single liquid ink used in this processing step and the single liquid ink used in the next printing step are the same. In such an embodiment, the processing step and the printing step are part of the same operation, i.e., the printing process is started by supplying a single liquid ink to the material after exposure, and the print cylinder is printed.
After the first rotation of the cyinder (typically less than 20 rotations, more preferably less than 10 rotations), the imaging layer is completely processed and then of high quality throughout the pressing operation. Get a printed copy. During the processing step, as described above, the areas of the image recording layer which are soluble in the single liquid ink or which can be dissolved in the single liquid ink by the exposing step are removed. The removed components are preferably transferred to printing paper.

It is also possible to provide an optional step before the processing of the image-forming material with a single liquid ink, such that the preceding optional step does not substantially remove the image recording layer. The image recording layer is wetted or swollen by first supplying water or an aqueous liquid in such a manner.

[0061]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Vinyl varnish (Vinyl Varn)
Preparation of ish) A stirrer, a nitrogen inlet, a condenser for total reflux and a monomer inlet were attached to a glass reactor, and Ketr was added thereto.
ul 220 (middle distillate of petroleum, Total Petro
leum, Inc. Is available in an amount of 44.19 parts by weight. This solvent is replaced with a nitrogen blanket (blanc)
Heat to 160 ° C. with stirring under ket). In this reactor, 36.01 parts by weight of styrene, 12.27 parts by weight of stearyl methacrylate and 2.27 parts by weight of divinylbenzene were added.
A monomer mixture of 62 parts by weight, 1.89 parts by weight of methacrylic acid and 2.79 parts by weight of t-butyl peroxyisopropyl carbonate (75% solution in mineral spirits) is added over 3 hours. After the addition of the monomer is completed, 0.23 parts by weight of t-butyl peroxyisopropyl carbonate is added over 15 minutes. 160 temperature
C. for a further 2 hours causes complete conversion of the monomer to polymer.

The measured amount of non-volatiles (NVM) is 55%. The percent conversion, determined by dividing NVM by the total weight percent of the monomers, is 100.1. The acid value of the solution is 12.0 mg KOH per gram.
The viscosity is 30 stokes [bubble tube (bubb
le tube), 54.4 ° C]. Solvent tolerance is 23
0% and the NVM at the cloud point is 16.7%. 2. Preparation of Single Liquid Ink While stirring 142.0 grams of the following mixture B, 58.0 grams of the following mixture A is added thereto. The mixing of the ink composition is performed for 20 minutes while maintaining the vortex while maintaining the temperature at 60 ° C. or lower using a disperser. The time for dropping this ink composition once at 30 ° C. through Laray in an amount of 500 grams is 1
4 to 17 seconds. Mixture A: 1 diethylene glycol in a glass beaker
81.0 grams, 8.0 grams of water, 0.4 parts of citric acid
Gram and 0.4 gram of magnesium nitrate and mix them until clear. Add 191.2 grams of diethylene glycol and mix until uniform. Mixture B: Using a high speed mixer, 46.0 grams of the vinyl varnish and 4.0 grams of Blue Flush.
12-FH-320 [CDR Corporation]
n (available from Elizabethtown, Ky)] and 1.0 gram of industrial quality soybean oil [Cargill
(Available from Chicago, Ill.)] And 0.6
Mix grams of antioxidant. While mixing, add 3 parts of a hydrocarbon resin solution [60% LX-2600 in EXX-Print 283D (available from Neville)].
4.4 grams, carbon black (Cabot Cor)
p. 27.0 grams of CSX-156 available from Carr Inc. and polytetrafluoroethylene wax (Carr
ol Pinna available from Scientific
cle 9600D). High speed mixing is performed at 149 ° C. for 30 minutes. EXXX-
Print 588D (available from Exxon)
Add 7.0 grams. This premix (premi
x) is ground with a shot mill to a suitable grind.

Mixture B had a Laray viscosity of 180
To 240 poise and a Lalay yield of 800
To 1200 (Test Method ASTM D4040:
Power Law-3k, 1.5k, 0.7k, 0.
3k). When the mixture B was subjected to a test using an Inkometer at 1200 rpm for 1 minute, the measurement result was 25 to 29 units. 3. Lithographic substrate A pH of 4 is applied to a PET web with a thickness of 0.175 mm.
One-layer coating with a 3.6% coating aqueous solution was applied so that the film thickness in a wet state became 50 μm. After cooling this layer at 10 ° C. for 30 seconds, the water content is 4 g / m
Dry with air of ³ at a temperature of 50 ° C. for at least 3 minutes. The resulting hydrophilic base layer is a ^{_{TiO 2 8990mg / m 2, SiO}} 2 and ^{900mg / m 2, 990mg / m} 2 of polyvinyl alcohol, Saponin
(Trademark) 81.6 mg / m ² , HOSTAPON T
(TM) and 36.8 mg / m ² and FT248 (TM) contained 605 mg / m ^2.

SAPONIN is a nonionic surfactant mixture composed of an ester and a polyglycoside, which is commercially available from Merck. H
OSTAPON T is an anionic surfactant commercially available from Hoechst AG. FT248
Is an anionic perfluorosurfactant commercially available from Bayer AG.

The TiO ₂ and SiO ₂ described above were added to the coating solution as a dispersion of these in polyvinyl alcohol. The average particle size of the TiO ₂ dispersion ranged from 0.3 to 0.5 μm. The polyvinyl alcohol is a hydrolyzate of polyvinyl acetate, which is available from Wacker Chemie Gm.
It is commercially available from bH (Germany) under the trademark POLYVIOL WX ^™ . The above-mentioned SiO ₂ was added as a dispersion in a hydrolyzate of tetramethyl orthosilicate. 4. Image recording layer A 2.61% by weight solution in water was produced by mixing polystyrene latex, a heat absorbing compound and a hydrophilic binder. This solution was coated on the hydrophilic base layer of the PET support described above. The thickness of this image recording layer after drying was 0.83 μm, which was 75% by weight of polystyrene latex, 10% by weight of infrared dye IR-1 and polyacrylic acid (N.
V. Allied Colloids Belgium
Glascol E15) commercially available from
The content was 5% by weight.

[0066]

Embedded image

5. Evaluation Quickmaster DI 46-, a dolographic digital press equipped with an infrared laser diode exposure device integrated with the supply spool and uptake pool located inside the plate cylinder.
4 [Heidelberger Druckmash
inen (Germany)] was filled with the imaging material. After the exposure, the press was started to supply the single liquid ink described above to the image recording layer. After 10 revolutions the processing step was completed and the unexposed areas obtained a clean print without absorbing the ink.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Giosef Bander Ah Belgium 2640 Maltcell Septes Trat 27 Agfa-Gevert na Mrose Fennoutjapp・ B 2640 Malt cell septestrat 27 ・ Agfa-Gevert ・ Na Mrose ・ Fennoutjap F-term (reference) 2H025 AB03 AC01 AC08 AD01 AD03 BA03 BH03 BJ03 CB54 2H084 AA14 AE05 BB02 BB04 CC05 2H0909 AA06 BA12 AA23 AA28 BA02 DA08 DA25 DA34 DA48 DA51 DA52 EA01

Claims (10)

[Claims] 1. A lithographic printing method comprising: (i) (1) a soft lithographic substrate having a hydrophilic surface and (2) removable with a single liquid ink or by exposure to heat or light. Rewinding a web of imaging material comprising an image recording layer that can be removed with a single liquid ink from a supply spool;
(Ii) wrapping the imaging material around a cylinder of a printing press, (iii) exposing the image recording layer to heat or light in an image-wise manner, and (iv) supplying a single liquid ink. Processing the image recording layer to obtain a printing master, (v) performing printing by supplying a single liquid ink to the printing master attached to the plate cylinder of the printing press, and (vi) performing the printing. Removing the print master from the plate cylinder. 2. A non-abrasive, wherein said image recording layer is removable with said single liquid ink prior to exposure to heat or light and becomes non-removable upon exposure to heat or light. The method according to claim 1, which is a non-ablative image recording layer. 3. The method according to claim 2, wherein said image recording layer comprises hydrophobic thermoplastic polymer particles. 4. The method of claim 3, wherein said image recording layer further comprises a hydrophilic binder. 5. The method of claim 2, wherein said image recording layer comprises an aryldiazosulfonate polymer. 6. The method according to claim 1, wherein the supply spool is located in the plate cylinder. 7. The method according to claim 1, wherein step (vi) is performed by winding the print master around an uptake pool located in the plate cylinder. 8. The method according to claim 1, wherein the soft lithographic substrate comprises a plastic support, a thin aluminum support or a laminate of plastic and thin aluminum. 9. The method of claim 1, wherein the single liquid ink is an emulsion comprising: a continuous phase comprising an acid functional vinyl resin; and a discontinuous phase comprising a liquid polyol. . 10. The method according to claim 10, wherein the vinyl resin has a content of about 1000 to about 1
A number average molecular weight in the range of 5000 and at least about 1000
The process according to claim 9, which is an acid-functional branched vinyl resin having a weight average molecular weight of 00.