ES2436000T3 - Precursor of lithographic printing plate - Google Patents

Abstract

Precursor of heat sensitive positive lithographic printing plate comprising on a support of granulated and anodised aluminum that has a hydrophilic surface or that is provided with a hydrophilic layer and that has an anodic weight between 1 and 4 g / m2, a coating sensitive to heat and / or light comprising a surfactant, characterized in that the surfactant comprises a polyether block that includes a fluoroalkyl side group and a urethane binding group.

Description

Precursor of lithographic printing plate

5 Field of the invention

The present invention relates to a lithographic printing plate precursor.

Background of the invention

10 Lithographic printing presses use the so-called printing matrix as a printing plate that is mounted on a cylinder of the printing press. The matrix carries a lithographic image on its surface and an impression is obtained by applying ink to said image and then transferring the matrix ink to a receiving material, which is usually paper. In the conventional method, called "wet" lithographic printing,

15 supplies the ink as well as an aqueous wetting solution (also called a wetting liquid) to the lithographic image consisting of oleophilic (or hydrophobic, that is to say they accept ink and repel water) areas as well as hydrophilic (or oleophobic, that is to say that they accept the water and repel the ink). In the so-called driographic printing, the lithographic image consists of areas that accept the ink and do not absorb the ink (repel the ink) and during driographic printing, only ink is supplied to the matrix.

20 Printing matrices are generally obtained by image exposure and the processing of an image forming material called plate precursor. In addition to the well-known photosensitive plates, called presensitized, which are suitable for UV contact exposure through a film mask, in the late 1990s the precursors of

25 heat sensitive printing plate. Such thermal materials offer the advantage of daylight stability and are especially used in the so-called iron-on computer method where the plate precursor is directly exposed, that is, without the use of a film mask. The material is exposed to heat or infrared light and the heat generated triggers chemical (physical) processes, such as ablation, polymerization, insolubilization by crosslinking of a polymer, heat-induced solubilization or coagulation of particles of a polymer latex.

30 thermoplastic.

The most popular thermal plates form an image by the difference in heat-induced solubility in an alkaline developer between the exposed and unexposed areas of the coating. The coating usually comprises an oleophilic binder, for example a phenolic resin, whose dissolution rate in the developer is

35 reduces (process in negative) or increases (process in positive) through image exposure. During processing, differential solubility leads to the removal of the non-image (non-printing) areas of the coating, thereby exposing the hydrophilic support, while the image (printing) areas of the coating remain in support. The usual examples of such plates are described, for example, in EP-A 625728, 823327, 825927, 864420, 894622 and 901902.

Negative process embodiments of such thermal materials often require a preheating stage between exposure and development as described, for example, in EP625,728.

Negative process plate precursors that do not require a preheating stage can

45 contain an image recording layer that works by heat-induced particle coalescence of the particles of a thermoplastic polymer (latex), as described, for example, in EP-As 770 494, 770 495, 770 496 and 770 497. These patents disclose a method of manufacturing a lithographic printing plate comprising the steps of (1) displaying an image forming element comprising hydrophobic thermoplastic polymer particles dispersed in a hydrophilic binder and a

50 compound capable of converting light into heat, (2) and revealing the element exposed by images by applying wet solution and / or ink.

Some of these thermal processes allow the manufacture of plates without wet processing and are based, for example, on the ablation of one or more layers of the coating. In the exposed areas the surface of

An underlying layer having an affinity towards the ink or the wetting solution different from the surface of the unexposed coating.

Other thermal processes that allow the manufacture of plates without wet processing are, for example, processes based on the heat-induced hydrophilic / oleophilic conversion of one or more layers of the coating of

60 so that in the exposed areas an affinity towards the ink or the different humectant is created than on the surface of the unexposed coating.

JP 2006/330670 discloses a printing plate precursor containing a coating that includes a diffusion agent comprising a fluoroalkyl group.

65 Printing plate precursors are susceptible to damage caused by mechanical forces applied to the surface of the coating during transport, mechanical handling and / or manual handling. After coating and drying, the thermal printing plate precursors are cut, stacked and packed in boxes by means of specific packaging equipment. During the transport of packaged printing plate precursors, the plates can move over each other. The degree of this sliding character can be determined by the coefficient of static friction that is measured between two stacked precursors: a low coefficient of static friction between the surface of a printing plate precursor and the separation sheet between parts on top thereof, or between the surface of a printing plate precursor and the aluminum back of the plate on the top thereof, in the case that no separation sheets between parts are used, results in the sliding of the plates. The sliding of the plates not only causes unsafe situations during transport, but also leads to damage to the surface of the plate precursor, such as, for example, the formation of the well-known "chafing". Chafing is unacceptable from an aesthetic point of view, but these coating areas often do not absorb enough ink during printing and result in poor, sometimes unacceptable, print quality. On the other hand, the printing plate precursors characterized by a surface having a high coefficient of static friction will be much less sliding but, in general, the preparation - that is, the coating capacity of such printing plate precursors is difficult in industrial coating and drying conditions. Therefore, a precursor with an irregular and non-uniform surface is obtained - also referred to in the art as a surface with poor coating cosmetics. Therefore, in the industrial coating and drying conditions it is very difficult to obtain a printing plate precursor with a surface characterized by excellent coating cosmetics and at the same time a high coefficient of static friction.

Summary of the invention

An object of the present invention is to provide a printing plate precursor with a heat and / or light sensitive coating having a smooth, regular and uniform surface, and at the same time having a sufficiently high friction coefficient; that is, a coefficient of friction whereby stacked plate precursors do not move easily with each other during handling and / or transport.

This objective is achieved by claim 1, that is, a heat sensitive positive process lithographic printing plate precursor comprising a support having a hydrophilic surface or that is provided with a hydrophilic layer, and a heat sensitive coating and / or in the light comprising a surfactant, characterized in that said surfactant comprises a polyether block that includes a fluoroalkyl side group and a urethane binding group.

It was surprisingly discovered that the surfactants used in the present invention, unlike the prior art surfactants, not only provide a good coating ability to the coating - that is, a good coating cosmetic or a coating with a regular and smooth surface - but at the same time they provide a coating with a coefficient of friction sufficiently high.

Other features, elements, steps, features and advantages of the present invention will be more apparent from the following detailed description of the preferred embodiments of the present invention.

Detailed description of the invention

The lithographic printing plate precursor of the present invention comprises a heat and / or light sensitive coating on a support. The imaging mechanism of such printing plate precursors can be triggered by direct exposure to heat, for example by means of a thermal head, or by light absorption of one or more coating compounds that are capable of converting light, more preferably infrared light, in heat.

The coating comprises a surfactant comprising a polyether block that includes a fluoroalkyl side group and a urethane binding group. The fluoroalkyl group may be linear or branched and includes a unit - (CF2) -and / or - (CHF) -. The number of such units may be 1, ie - (CF3), - (CHF2) or - (CH2F); or more than 1, preferably less than 20; more preferably less than 15 and most preferably between 2 and 10.

In a preferred embodiment, the polyether block includes an alkoxyfluoroalkyl side group. The alkoxyfluoroalkyl group includes a unit - [(CRaRb) g-O- (CRcRd) h-fluoroalkyl] -where Ra, Rb, Rc and Rd independently represent hydrogen, an alkyl or fluoroalkyl group and g and h independently represent an integer number ≥ 0.

The urethane binding group present in the surfactant may be attached to the polyether block which includes the fluoroalkyl group and / or the lateral alkoxyfluoroalkyl group; or it may be attached to another polymer block such as a polyether, polyester, polyurethane or polyvinyl alcohol block optionally present in the surfactant.

The surfactant used in the present invention preferably comprises the structural unit represented by the following formula (I):

5 where a and b independently represent an integer ≥ 0; c represents an integer that varies between 1 and 40, preferably an integer that varies between 2 and 20; Y1 represents a fluoroalkyl group or an alkoxyfluoroalkyl group;

10 Y2 represents hydrogen; an optionally substituted alkyl group such as a methyl, ethyl, propyl, isopropyl, butyl, tertiary butyl or pentyl group, a fluoroalkyl group or an alkoxyfluoroalkyl group; R1 to R4 independently represent hydrogen, fluoride, an optionally substituted alkyl group such as, for example, a methyl, ethyl, propyl, isopropyl, butyl, tertiary butyl or pentyl group; a fluoroalkyl group or an optionally substituted aryl group.

The optional substituents of the alkyl or aryl group may be a halogen such as F, Cl, Br or I; an alkyl group

or a fluoroalkyl group. The fluoroalkyl group and the alkoxyfluoroalkyl group have been defined above.

In a more preferred embodiment, the surfactant comprises the structural unit represented by formula (I) 20 where:

a and b independently represent an integer ≥ 0; c represents an integer that varies between 1 and 40, preferably an integer that varies between 2 and 20; Y1 represents a fluoroalkyl group or an alkoxyfluoroalkyl group;

25 Y2 represents hydrogen; an optionally substituted alkyl group such as a methyl, ethyl, propyl, isopropyl, butyl, tertiary butyl or pentyl group; R1 to R4 independently represent hydrogen, fluoride, an optionally substituted alkyl group such as, for example, a methyl, ethyl, propyl, isopropyl, butyl, tertiary butyl or pentyl group; a fluoroalkyl group or an optionally substituted aryl group. The optional substituents of the alkyl or aryl group may be a

Halogen such as F, Cl, Br or I; an alkyl group or a fluoroalkyl group.

The fluoroalkyl group and the alkoxyfluoroalkyl group have been defined above.

In the most preferred embodiment, the surfactant includes a polyether block that includes an alkoxyfluoroalkyl side group and a urethane binding group represented by the formula (II):

where d and e represent an integer ≥ 0;

40 X represents a fluoroalkyl group; Y3 represents hydrogen or an optionally substituted alkyl group such as a methyl, ethyl, propyl, isopropyl, butyl, tertiary butyl or pentyl group; and f represents an integer that varies between 1 and 40, preferably an integer that varies between 2 and 20. The optional substituents of the alkyl or aryl group may be a halogen such as F, Cl, Br or I; an alkyl group

45 or a fluoroalkyl group.

The surfactant used in the present invention may further comprise one or more polyether blocks that are represented by formula (III):

or a fluoroalkyl group.

The structural units represented by formulas (I) and / or (II) may be joined together and / or may be

10, optionally linked through a linking group, to a polyether block represented by formula (III), a polyester, polyurethane or polyvinyl alcohol block forming diblock copolymers. By additional bonding of diblock copolymers, multiblock copolymers can be formed.

Such diblock copolymers can be prepared, for example, by reaction of a polyether terminated in

Monohydroxy comprising a fluoroalkyl or alkoxyfluoroalkyl side group with one, two or more isocyanate functional groups of a mono, di or multiisocyanate compound, optionally followed by the reaction of the remaining isocyanate group or functional groups with a polyether optionally comprising a side group fluoroalkyl or alkoxyfluoroalkyl, a polyester, polyurethane or polyvinyl alcohol. If the hydroxy terminated polyether comprising a fluoroalkyl or alkoxyfluoroalkyl side group contains two or more hydroxy terminal groups, it is

20 obtains triblock or multiblock copolymers by reaction with mono, di and / or multi-isocyanate compounds. These tri or multi-block copolymers may comprise, for example, the following structural units:

25 where independently in each of the above structures m, n, o, p and w independently represent an integer that varies between 1 and 40, preferably an integer that varies between 2 and 20.

Hydroxy-terminated polyethers comprising a fluoroalkyl or alkoxyfluoroalkyl side group can be obtained, for example, by cationic ring opening polymerization of a fluoroalkyl or alkoxyfluoroalkyl substituted oxetane with an alcohol as initiator. The alcohol initiator may be a monofunctional alcohol or a multifunctional alcohol such as a diol, a triol or a tetraalcohol. They can have a low molecular weight (i.e. non-polymeric) or they can be polymeric alcohols such as condensation polymers, for example, polyurethanes, polyesters or mono- or dihydroxy-terminated polyethers or addition polymers, by

5 example, polyvinyl alcohol. When the alcohols are monofunctional, fluoroalkyl and / or alkoxyfluoroalkyl polyethers terminated in monohydroxy are obtained; when the alcohols are multifunctional, fluoroalkyl and / or alkoxyfluoroalkyl polyethers terminated in multihydroxy are obtained, such as, for example, fluoroalkyl and / or alkoxyfluoroalkyl polyethers terminated in bis, tris or tetrahydroxy (star branching).

Oxetanes substituted with fluoroalkyl and alkoxyfluoroalkyl suitable for the preparation of surfactants include:

hexafluoropropylene oxide:

perfluoroisobutene oxide:

Trifluoro (1,1,2,2-tetrafluoroethyl) -oxyran:

6-hydroperfluoro-1,2-epoxyhexane:

trifluoro (nonafluorobutyl) oxirane:

2,2-Difluoro-3-phenyl-3- (trifluoromethyl) -oxyran:

(heptafluoropropyl) -oxyran,

(heptafluoropropyl) -oxyran:

2,2-bis (trifluoromethyl) oxirane:

trifluoromethyloxyran:

[[2,3,3,3-tetrafluoro-2- (heptafluoropropoxy) propoxy] methyl) -oxyran:

[[2,3,3,3-tetrafluoro-2- [1,1,2,3,3,3-hexafluoro-2- (heptafluoropropoxy) propoxy] propoxy] methyl] -oxyran:

3- (2,2,2-trifluoroethoxymethyl) -3-methylxetane:

3-methyl-3 - [(2,2,3,3,3-pentafluoropropoxy) methyl] oxetane:

3-methyl-3 - [[(2,2,3,3,4,4,5,5,6,6,7,7,8,8,8-pentadecafluorooctyl) oxy] methyl] -oxetane:

3,3-bis [(2,2,2-trifluoroethoxy) methyl] -oxetane:

3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctyloxymethyl-3-methylxetane:

3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-heptadecafluorodecyloxymethyl-3-methylxetane:

3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,12,12,12-heneicosafluorododecyloxymethyl-3-methylxetane:

3,3-bis (2,2,3,3,4,4,4-heptafluorobutoxymethyl) -3-oxetane:

3-methyl-3 - [[(3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctyl) oxy] methyl] oxetane:

3,3-bis [[(2,2,3,3,4,4,5,5,6,6,7,7,8,8,8-pentadecafluorooctyl) oxy] methyl] -oxetane:

3- (2,2,3,3,4,4,4-heptafluorobutoxymethyl) -3-methylxetane:

3 - [(2,2,3,3,4,4,4-heptafluorobutoxy) methyl] -3-methylxetane:

3 - [(2,2,3,3,4,4,4-heptafluorobutoxy) methyl] -3-methylxetane:

2,2,3,4-tetrafluoro-4- [1,2,2,2-tetrafluoro-1- [1,1,2,3,3,3-hexafluoro-2- (heptafluoropropoxy) propoxy] ethyl] - 3 (trifluoromethyl) -oxetane:

2,2,3,4-tetrafluoro-4- [1,1,3,4,4,6,7,7,9,10,10,12,12,12-tetradecafluoro-3,6,9-tris (trifluoromethyl) -2,5,8,11-tetraoxadodec-1-yl] -3- (trifluoromethyl) -oxetane:

2,3,3-trifluoro-2- [1,1,2,3,3,3-hexafluoro-2- (heptafluoropropoxy) propoxy] -oxetane:

Suitable isocyanates for the preparation of the surfactants include monofunctional isocyanates such as phenyl isocyanate, stearyl isocyanate, 2- (methacryloxy) ethyl isocyanate, methyl isocyanate, isocyanocyclohexane, ethyl isocyanate, 1- (isocyanatomethyl) benzene, isocyanate -methoxyphenyl, isopropyl isocyanate, m-anisyl isocyanate and 2-tolyl isocyanate; diisocyanates such as 1,6-hexylene diisocyanate, 4,4'-diphenylmethane diisocyanate, isophorone diisocyanate, tolylene diisocyanate, 4,4'-diisocyanaticyclohexylmethane, 1,4-phenylene diisocyanate, tetramethylene isocyanate, dodecylmethane diisocyanate ,

1,5-naphthylene diisocyanate and m-xylylene diisocyanate; or multifunctional isocyanates such as the hexamethylene diisocyanate isocyanurate trimer.

A specific diisocyanate of interest is the following isophorone diisocyanate:

The bonding group that can join the structural units represented by formulas (I), (II) and / or (III) and / or other polymeric blocks such as, for example, polyester, polyurethane or polyvinyl alcohol blocks, can have up to 20 carbon atoms and may contain at least one atom selected from C, H, N, O and S. Preferred binding groups are a linear alkylene group having 1 to 18 carbon atoms, a linear, branched group, or cyclic having 3 to 18 carbon atoms, an alkynylene group having 2 to 18 carbon atoms and a

10 arylene group having 6 to 20 atoms, -O-, -S-, -CO-, -CO-O-, -O-CO-, -CS-, -NRnRo-, -CO-NRn-, - NRn-CO-, -NRn-CO-O-, -O-CO-NRn-, -NRn-CO-NRo-, -NRn-CS-NRo-, a phenylene group, a naphthalene group, an anthracene group, a heterocyclic group, or combinations thereof, where Rn and Ro each independently represent hydrogen or an alkyl, alkenyl, alkynyl, cycloalkyl, heterocyclic, aryl, heteroaryl, aralkyl or optionally substituted heteroaralkyl group. Preferred substituents of the latter groups are an alkoxy group that

15 has up to 12 carbon atoms, a halogen or a hydroxyl group.

Suitable examples of diblock and multiblock surfactants include the following surfactants:

where independently in each of the above structures m, n, o, p, r, s, t, x, y, u, q and v independently represent an integer that varies between 1 and 40, preferably an integer that varies between 2 Y

twenty.

The amount of surfactant in the coating preferably ranges between 0.05% by weight and 5% by weight, more preferably between 0.1% by weight and 3% by weight and most preferably between 0.15% by weight and 1.5% by weight.

The thermal printing plate precursor comprises a heat and / or light sensitive coating and is process positive. Its working mechanism is based on the heat-induced solubilization of an oleophilic resin. The oleophilic resin is preferably a polymer that is soluble in an aqueous developer, more preferably in an aqueous alkaline developer solution with a pH between 7.5 and 14. Preferred polymers are phenolic resins, for example, novolac, resols, polyvinyl phenols and polymers substituted with carboxy. Typical examples of these polymers are described in Patent documents DE 4007428, DE 4027301 and DE 4445820. The amount of phenolic resin present in the coating is preferably at least 50% by weight, preferably at least 80% by weight with with respect to the total weight of all the components present in the coating. The oleophilic resin is preferably a phenolic resin wherein the phenyl group or the hydroxy group is chemically modified with an organic substituent. Phenolic resins that are chemically modified with an organic substituent may exhibit increased chemical resistance against printing chemicals such as wetting solutions or plate treatment liquids such as plate cleaners. Examples of such chemically modified phenolic resins are described in EP 934 822; EP 1 072 432; US 5,641,608; EP 982 123; WO 99/01795; EP 2 102 446, EP 2 102 444; EP 2 102 445; EP 2 102 443; EP 3 102 522; WO04 / 035310; WO04 / 035686; WO04 / 035645; WO04 / 035687

or EP 1 506 858. The modified resins described in EP 2 102 446 are preferred, especially resins where the phenyl group of said phenolic resin is substituted with a group having the structure -N = NQ, where the group -N = N-is covalently bonded to a carbon atom of the phenyl group and where Q is an aromatic group.

Novolac resin or resol resin can be prepared by polycondensation of at least one member selected from aromatic hydrocarbons such as phenol, o-cresol, p-cresol, m-cresol, 2,5-xylenol, 3,5-xylenol, resorcinol , pyrogallol, bisphenol, bisphenol A, trisphenol, o-ethylphenol, p-ethylphenol, propylphenol, n-butylphenol, t-butylphenol, 1-naphthol and 2-naphthol, with at least one aldehyde or ketone selected from aldehydes, such as formaldehyde, glyoxal, acetaldehyde, propionaldehyde, benzaldehyde and furfural and ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone, in the presence of an acid catalyst. Instead of formaldehyde and acetaldehyde, paraformaldehyde and paraldehyde can be used, respectively.

The weight average molecular weight, measured by gel permeation chromatography using universal calibration and polystyrene standards, of the novolac resin is preferably 500 to 150,000 g / mol, more preferably 1,500 to 50,000 g / mol.

The poly (vinylphenol) resin may also be a polymer of one or more hydroxyphenyl-containing monomers such as hydroxystyrenes or hydroxyphenyl (meth) acrylates. Examples of such hydroxystyrenes are o-hydroxystyrene, m-hydroxystyrene, p-hydroxystyrene, 2- (o-hydroxyphenyl) propylene, 2- (m-hydroxyphenyl) propylene and 2- (phydroxyphenyl) propylene. Such hydroxystyrene may have a substituent such as chlorine, bromine, iodine, fluorine or a C1-4 alkyl group, in its aromatic ring. An example of such hydroxyphenyl (meth) acrylate is 2-hydroxyphenyl methacrylate.

The poly (vinylphenol) resin can usually be prepared by polymerization of one or more monomers containing hydroxyphenyl in the presence of a radical initiator or a cationic polymerization initiator. The poly (vinylphenol) resin can also be prepared by copolymerizing one or more of these monomers containing hydroxyphenyl with other monomeric compounds such as acrylate monomers, methacrylate monomers, acrylamide monomers, methacrylamide monomers, vinyl monomers, monomers of aromatic vinyl or diene monomers.

The weight average molecular weight, measured by gel permeation chromatography using universal calibration and polystyrene standards, of the poly (vinylphenol) resin is preferably 1,000 to 200,000 g / mol, more preferably 1,500 to 50,000 g / mol.

Examples of phenolic resins are:

-

ALNOVOL ™ SPN452, 40% by weight of a novolac resin in Dowanol ™ PM, commercially available from CLARIANT GmbH.

-

ALNOVOL ™ SPN400, 44% by weight of a novolac resin in Dowanol ™ PMA, commercially available from CLARIANT GmbH.

-

ALNOVOL ™ HPN100, novolac resin commercially available from CLARIANT GmbH.

-

DURITE ™ PD443, novolac resin commercially available from BORDEN CHEM. INC.

-

DURITE ™ SD423A, novolac resin commercially available from BORDEN CHEM. INC.

5 -DURITE ™ SD126A, novolac resin commercially available at BORDEN CHEM. INC.

-

BAKELITE ™ 6866LB02, novolac resin commercially available from BAKELITE AG.

-

BAKELITE ™ 6866LB03, novolac resin commercially available from BAKELITE AG. 10 -KR 400/8, novolac resin commercially available from KOYO CHEMICALS INC.

-

HRJ 1085, novolac resin commercially available from SCHNECTADY INTERNATIONAL INC.

15 -HRJ 2606, novolac phenol resin commercially available from SCHNECTADY INTERNATIONAL INC.

-

LYNCUR ™ CMM, copolymer of 4-hydroxystyrene and methyl methacrylate commercially available from SIBER HEGNER.

The coating may comprise a second layer comprising a polymer or copolymer (ie (co) polymer) comprising at least one monomer unit comprising at least one sulfonamide group. The layer is located between the layer described above comprising the oleophilic resin and the hydrophilic support. Hereinafter, "a (co) polymer comprising at least one monomer unit comprising at least one sulfonamide group" is also referred to as "a sulfonamide (co) polymer". The (co) polymer

Sulfonamide is preferably soluble in bases. The sulfonamide group is preferably represented by -NR-SO2-, -SO2-NR-or -SO2-NRR 'where R and R' each independently represent hydrogen or an organic substituent.

The surfactant used in the present invention may be present in the first layer, the second layer or in another optional layer. More preferably, the surfactant is present in the layer comprising the oleophilic resin.

The sulfonamide (co) polymers are preferably high molecular weight compounds prepared by homopolymerization of monomer units containing at least one sulfonamide group or by copolymerization of such monomer units and other polymerizable monomer units.

Examples of monomer units that contain at least one sulfonamide group include monomer units that also contain at least one polymerizable unsaturated bond such as an acryloyl, allyl or vinyloxy group. Suitable examples are disclosed in U.S. Patent documents. 5,141,838, EP 1,554,878; EP 909,657, EP 0 894 622 and EP 1,120,246.

Examples of monomeric unions copolymerized with the monomer units containing at least one sulfonamide group include monomer units as disclosed in EP 1,262,318, EP 1,275,498, EP 909,657, EP 1,120,246, EP 0 894 622 and EP 1,400,351.

Suitable examples of (co) sulfonamide polymers and / or their method of preparation are disclosed in EP-A 933 682, EP-A 982 123, EP-A 1,072 432, WO 99/63407 and EP 1,400,351.

A highly preferred example of a sulfonamide (co) polymer is a homopolymer or copolymer comprising a structural unit represented by the following general formula (IV):

where: R9 represents hydrogen or a hydrocarbon group having up to 12 carbon atoms; preferably R9 represents hydrogen or a methyl group;

X1 represents a single bond or a divalent linking group. The divalent linking group may have up to 20 carbon atoms and may contain at least one atom selected from C, H, N, O and S. Preferred divalent binding groups are a linear alkylene group having 1 to 18 carbon atoms. , a linear, branched, or cyclic group having 3 to 18 carbon atoms, an alkynylene group having 2 to 18 carbon atoms and an arylene group having 6 to 20 atoms, -O-, -S- , -CO-, -CO-O-, -O-CO-, -CS-, -NRnRo-, -CO-NRn, -NRn-CO-, -NRn-CO-O-, -O-CO-NRn -, -NRn-CO-NRo-, -NRn-CS-NRo-, a phenylene group, a naphthalene group, an anthracene group, a heterocyclic group, or combinations thereof, where Rn and Ro each independently represent hydrogen or an optionally substituted alkyl, alkenyl, alkynyl, cycloalkyl, heterocyclic, aryl, heteroaryl, aralkyl or heteroaralkyl group. Preferred substituents of the latter groups are an alkoxy group having up to 12 carbon atoms, a halogen or a hydroxyl group. Preferably X1 is a methylene group, an ethylene group, a propylene group, a butylene group, an isopropylene group, a cyclohexylene group, a phenylene group, a tolylene group or a biphenylene group;

Y4 is a divalent sulfonamide group represented by -NRp-SO2-or -SO2-NRq-where Rp and Rq each independently represent hydrogen, an alkyl, alkanoyl, alkenyl, alkynyl, cycloalkyl, heterocyclic, aryl, heteroaryl, aralkyl or heteroaralkyl group optionally substituted or a group of the formula -C (= N) -NH-R10 where R10 represents hydrogen or an optionally substituted alkyl or aryl group;

Z1 represents a terminal group preferably represented by hydrogen or an optionally substituted linear, branched, or cyclic alkylene or alkyl group having 1 to 18 carbon atoms such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a t-butyl group, an s-butyl group, a pentyl group, a hexyl group, a cyclopentyl group, a cyclohexyl group, an octyl group, an optionally substituted arylene group or an aryl group that it has 6 to 20 carbon atoms; an optionally substituted heteroarylene or heteroaryl group; a linear, branched, or cyclic alkenylene or alkenyl group having from 2 to 18 carbon atoms, a linear, branched, or cyclic alkynylene or alkynyl group having from 2 to 18 carbon atoms or an alkoxy group.

Examples of preferred substituents optionally present in the groups represented by Z1 are an alkyl group having up to 12 carbon atoms, an alkoxy group having up to 12 carbon atoms, a halogen atom or a hydroxyl group.

The structural unit represented by the general formula (IV) preferably has the following groups:

X1 represents an alkylene, cyclohexylene, phenylene or tolylene group, -O-, -S-, -CO-, -CO-O-, -O-CO-, -CS-, -NRnRo, -CO-NRn-, - NRn-CO-, -NRn-CO-O-, -O-CO-NRn-, -NRn-CO-NRo-, -NRn-CS-NRo-, or combinations thereof, and where Rn and Ro represent each one independently hydrogen or an optionally substituted alkyl, alkenyl, alkynyl, cycloalkyl, heterocyclic, aryl, heteroaryl, aralkyl or heteroaralkyl group. Preferred substituents of the latter groups are an alkoxy group having up to 12 carbon atoms, a halogen or a hydroxyl group;

Y4 is a divalent sulfonamide group represented by -NRp-SO2-, -SO2-NRq-where Rp and Rq each independently represent hydrogen, an alkyl, alkanoyl, alkenyl, alkynyl, cycloalkyl, heterocyclic, aryl, heteroaryl, aralkyl or heteroaralkyl group optionally substituted;

Z1 is a terminal group represented by hydrogen, an alkyl group such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a t-butyl group, an s-butyl group, a pentyl group, a hexyl group, a cyclopentyl group, a cyclohexyl group or an octyl group, a benzyl group, an optionally substituted aryl or heteroaryl group, a naphthyl group, an anthracenyl group, a pyridyl group, an allyl group or a group vinyl.

Specific preferred examples of (co) sulfonamide polymers are polymers comprising N- (paminosulfonylphenyl) (meth) acrylamide, N- (m-aminosulfonylphenyl) (meth) acrylamide and / or N- (o-aminosulfonylphenyl) (meth) acrylamide. A particularly preferred sulfonamide (co) polymer is a polymer comprising N- (paminosulfonylphenyl) methacrylamide wherein the sulfonamide group comprises an optionally substituted linear, branched, cyclic or heterocyclic alkyl group, an optionally substituted aryl group or an optionally substituted heteroaryl group.

The layer comprising the sulfonamide (co) polymer may further comprise additional hydrophobic binders such as a phenolic resin (for example, novolac, resols or polyvinyl phenols), a chemically modified phenolic resin or a polymer containing a carboxyl group, a group nitrile or a maleimide group.

The dissolving behavior of the coating can be precisely adjusted using optional solubility control components. More particularly, development accelerators and development inhibitors can be used. In the embodiment in which the coating comprises more than one layer, these ingredients may be added to the first layer, the second layer and / or another optional layer of the coating.

Development accelerators are compounds that act as dissolution promoters because they are capable of increasing the dissolution rate of the coating. For example, anhydrides of cyclic acids, phenols or organic acids can be used to improve the aqueous developing capacity. Examples of cyclic acid anhydrides include phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, 3,6-endoxy-4-tetrahydrophthalic anhydride, tetrachlorophthalic anhydride, maleic anhydride, chloromaleic anhydride, anhydride, alpha-phenyl anhydride, anhydride, anhydride, alpha-phenyl anhydride, anhydride, alpha-phenylecide U.S. Patent document No.

4,115,128. Examples of the phenols include bisphenol A, p-nitrophenol, p-ethoxyphenol, 2,4,4'-trihydroxybenzophenone, 2,3,4trihydroxybenzophenone, 4-hydroxybenzophenone, 4.4 ', 4 "-trihydroxytriphenylmethane, and 4.4' , 3 ", 4" -tetrahydroxy-3,5,3 ', 5'tetramethyltriphenylmethane, and the like. Examples of organic acids include sulfonic acids, sulfinic acids, alkylsulfuric acids, phosphonic acids, phosphates, and carboxylic acids, such as It is described, for example, in JP-A patent documents with numbers 60-88,942 and 2-96,755. Specific examples of these organic acids include p-toluenesulfonic acid, dodecylbenzenesulfonic acid, p-toluenesulfinic acid, ethyl sulfuric acid, phenylphosphonic acid, phenylphosphinic acid, phenyl phosphate, diphenyl phosphate, benzoic acid, isophthalic acid, adipic acid, p-toluic acid, 3,4-dimethoxybenzoic acid, 3,4,5-trimethoxybenzoic acid, 3,4,5-trimethoxycinnamic acid, phthalic acid, terephthalic acid co, 4-cyclohexene-1,2-dicarboxylic acid, erucic acid, lauric acid, n-undecanoic acid, and ascorbic acid. The amount of the anhydride of cyclic acid, phenol, or organic acid contained in the coating is preferably in the range of 0.05 to 20% by weight, with respect to the coating as a whole. Polymeric development accelerators such as phenolic-formaldehyde resins comprising at least 70 mol% of meta-cresol as a recurring monomer unit are also suitable development accelerators.

In a preferred embodiment, the coating also contains developer resistance means, also called development inhibitors, that is to say one or more ingredients that are capable of retarding the dissolution of unexposed areas during processing. The dissolution inhibition effect is preferably reversed by heating, so that the dissolution of the exposed areas is not substantially delayed and thus a large dissolution differential can be obtained between the exposed and unexposed areas. Compounds described, for example, in EP-A 823 327 and WO97 / 3989 are believed to act as dissolution inhibitors due to the interaction, for example by the formation of hydrogen bonds, with the resin or soluble resins in coating bases. Inhibitors of this type usually comprise at least one hydrogen bridge forming group such as nitrogen atoms, onium groups, carbonyl (-CO-), sulfinyl (-SO-) or sulfonyl (-SO2-) groups and a bulky hydrophobic moiety such as one or more aromatic rings. Some of the compounds mentioned above, for example infrared dyes such as cyanines and contrast dyes such as quaternary triaryl methane dyes can also act as dissolution inhibitors.

Other suitable inhibitors improve the resistance to the developer because they retard the penetration of the aqueous alkaline developer in the coating. Such compounds may be present in the first layer and / or, if present, in the second layer as described, for example, in EP-A 950 518, and / or in a developing barrier layer in the upper part of said layer, as described, for example, in EP-A 864 420, EP-A 950 517, WO 99/21725 and WO 01/45958. In the last embodiment, the solubility of the barrier layer in the developer and the penetration capacity of the developer in the barrier layer can be increased by exposure to heat or infrared light.

Preferred examples of inhibitors that retard the penetration of the aqueous alkaline developer in the coating include the following:

(a) A polymeric material that is insoluble in or impenetrable by the developer, for example a hydrophobic or water-repellent polymer or copolymer such as acrylic polymers, polystyrene, styrene acryl copolymers, polyesters, polyamides, polyureas, polyurethanes, nitrocellulosics and epoxy resins ; or polymers comprising siloxane units (silicones) and / or perfluoroalkyl. (b) Difunctional compounds such as surfactants comprising a polar group and a hydrophobic group such as a long chain hydrocarbon group, a poly or oligosiloxane and / or a perfluorinated hydrocarbon group. A common example is Megafac F-177, a perfluorinated surfactant available from Dainippon Ink & Chemicals, Inc. A suitable amount of such components is between 10 and 100 mg / m2, more preferably between 50 and 90 mg / m2.

(c) Difunctional block copolymers comprising a polar block such as a poly or oligo (alkylene oxide) and a hydrophobic block such as a long chain hydrocarbon group, a poly or oligosiloxane and / or a perfluorinated hydrocarbon group. A suitable amount of such compounds is between 0.5 and 25 mg / m2, preferably between 0.5 and 15 mg / m2 and most preferably between 0.5 and 10 mg / m2. A suitable copolymer comprises about 15 to 25 siloxane units and 50 to 70 alkylene oxide groups. Preferred examples include copolymers comprising phenylmethylsiloxane and / or dimethylsiloxane as well as ethylene oxide and / or propylene oxide, such as Tego Glide 410, Tego Wet 265, Tego Protect 5001 or Silikophen P50 / X, all commercially available in Tego Chemie, Essen, Germany. Said poly or oligosiloxane may be a linear, cyclic or complex cross-linking polymer or copolymer. The term "polysiloxane compound" will include any compound that contains more than one siloxane group -Si (R, R ') - O-, where R and R' are optionally substituted alkyl or aryl groups. Preferred siloxanes are phenylalkyl siloxanes and dialkylsiloxanes. The number of siloxane groups in the polymer or oligomer is at least 2, preferably at least 10, more preferably at least 20. It may be less than 100, preferably less than 60.

5 It is believed that during coating and drying, the inhibitor of the types (b) and (c) mentioned above tends to position itself, due to its difunctional structure, at the interface between the coating and the air, and thus forms an upper separation layer even when applied as an ingredient of the coating solution of the first layer and / or the optional second layer. Simultaneously, surfactants also act as agents

10 diffusion that improve the quality of the coating. The upper separation layer formed in this way appears to be capable of acting as the barrier layer mentioned above that retards the penetration of the developer into the coating.

Alternatively, the inhibitor of types (a) to (c) can be applied in a separate solution, coated on the

15 upper part of the first layer, the optional second layer and / or other layers of the coating. In that embodiment, it may be advantageous to use a solvent in the separate solution that is not capable of dissolving the ingredients present in the other layers so that a highly concentrated water-repellent or hydrophobic phase is obtained at the top of the coating that is capable to act as the developing barrier layer mentioned above.

In addition, the first or second optional layer and / or the other layers may comprise polymers that further improve the length of the run and / or the chemical resistance of the plate. Examples thereof are polymers comprising imido side groups (-CO-NR-CO-), where R is hydrogen, optionally substituted alkyl or optionally substituted aryl, such as the polymers described in EP-A 894 622, EP

25 A 901 902, EP-A 933 682 and WO 99/63407.

The coating of the heat sensitive printing plate precursor also preferably contains an infrared light absorbing dye or pigment which, in the embodiment in which the coating comprises more than one layer, may be present in the first layer, and / or in the second layer, and / or another optional layer.

Preferred IR absorbing dyes are cyanine dyes, merocyanine dyes, indoaniline dyes, oxonol dyes, pyrilium dyes and squaril dyes. Examples of suitable IR dyes are described, for example, in EP-As 823327, 978376, 1029667, 1053868, 1093934; WO 97/39894 and 00/29214. A preferred compound is the following cyanine dye:

The concentration of the IR dye in the coating is preferably between 0.25 and 15.0% by weight, more preferably between 0.5 and 10.0% by weight, most preferably between 1.0 and a 7.5% by weight with respect to the coating as a whole.

The coating may further comprise one or more dyes such as dyes or pigments that stimulate a visible color in the coating and that remain in the coating in the image areas that are not removed during the processing stage. In this way a visible image is formed and inspection of the lithographic image on the disclosed printing plate is made possible. Such dyes are often referred to as dyes of

45 contrast or indicator dyes. Preferably, the dye has a blue color and a maximum absorption in the wavelength range between 600 nm and 750 nm. Typical examples of such contrast dyes are tri or diarylmethane dyes substituted with amino, for example crystal violet, methyl violet, pure victoria blue, flexoblau 630, basonilblau 640, auramine and malachite green. Suitable dyes that are discussed in depth in EP 400 706 are also suitable contrast dyes. Dyes which, combined with specific additives, color only lightly coated but become intensely colored after exposure can also be used as colorants , as described, for example, in WO2006 / 005688.

In order to protect the surface of the coating of printing plate precursors sensitive to heat and / or light, in particular from mechanical damage, a protective layer can also be optionally applied. The protective layer generally comprises at least one water soluble binder, such as polyvinyl alcohol, polyvinyl pyrrolidone, partially hydrolyzed polyvinyl acetates, gelatin, carbohydrates or hydroxyethyl cellulose, and can be produced in any known manner such as from a solution or dispersion. aqueous that may contain, if necessary, small amounts - that is, less than 5% by weight based on the total weight of the coating solvents in the protective layer - of organic solvents. The thickness of the protective layer may suitably be any amount, advantageously up to 5.0 µm, preferably 0.1 to 3.0 µm, particularly preferably 0.15 to 1.0 µm.

Optionally, the coating may also contain additional ingredients such as additional surfactants, silicon or titanium dioxide particles or polymer particles such as anti-slip agents and spacers.

Any coating method can be used for the application of two or more coating solutions to the hydrophilic surface of the support. The multilayer coating can be applied by coating / drying each layer consecutively or by simultaneously coating several coating solutions at the same time. In the drying stage, volatile solvents are removed from the coating until the coating is self-supporting and dry to the touch. However, it is not necessary (and may not even be possible) to remove any solvent in the drying stage. In fact, the residual solvent content can be contemplated as an additional variable composition by means of which the composition can be optimized. Drying is typically carried out by blowing hot air over the coating, usually at a temperature of at least 70 ° C, suitably 80-150 ° C and especially 90-140 ° C. You can also use infrared lamps. The drying time can usually be 15-600 seconds.

Between coating and drying, or after the drying stage, a heat treatment and subsequent cooling can provide additional benefits, as described in WO99 / 21715, EP-A 1074386, EP-A 1074889, WO00 / 29214, and WO / 04030923, WO / 04030924, WO / 04030925.

The support of the lithographic printing plate precursor can be a sheet-like material such as an iron or it can be a cylindrical element such as a sleeve that can slide around a printing cylinder of a printing press.

The lithographic support is a granulated and anodized aluminum support. The aluminum support usually has a thickness of approximately 0.1-0.6 mm. However, this thickness can be appropriately changed depending on the size of the printing plate used and / or the size of the plate recorders on which the printing plate precursors are exposed. The aluminum is preferably granulated by electrochemical granulation, and anodized by means of anodizing techniques employing phosphoric acid or a mixture of sulfuric acid / phosphoric acid. The methods of both granulating and anodizing aluminum are very well known in the art.

Through the granulation (or increased roughness) of the aluminum support, both the adhesion of the printing image and the wetting characteristics of the non-image areas are improved. By varying the type and / or concentration of the electrolyte and the voltage applied in the granulation stage, different types of grain can be obtained. The surface roughness is often expressed as the arithmetic mean roughness from the center line Ra (ISO 4287/1 or DIN 4762) and can vary between 0.05 and 1.5 µm. The aluminum substrate of the present invention preferably has a Ra value of less than 0.45 µm, more preferably less than 0.40 µm and most preferably less than 0.30 µm. The lower limit of the value of Ra is preferably about 0.1 µm. More details concerning the preferred Ra values of the surface of the granulated and anodized aluminum support are described in EP 1 356 926.

By anodizing the aluminum support, its abrasion resistance and hydrophilic nature are improved. The microstructure as well as the thickness of the Al2O3 layer are determined by the anodizing step; The anodic weight (g / m2 of Al2O3 formed on the aluminum surface) varies between 1 and 4 g / m2, preferably between 1 and 3.5 g / m2. The anodic weight is preferably ≥ 3 g / m2, more preferably ≥ 3.5 g / m2.

The granulated and anodized aluminum support can be subjected to a treatment called post-anodic to improve the hydrophilic surface properties. For example, the aluminum support can be "silicated" by surface treatment with a solution of sodium silicate at elevated temperature, for example 95 ° C. Alternatively, a phosphate treatment can be applied which involves the treatment of the surface of the aluminum oxide with a phosphate solution that can also contain an inorganic fluoride. In addition, the surface of the aluminum oxide can be rinsed with a solution of citric acid or citrate. This treatment can be carried out at room temperature or it can be carried out at a slightly elevated temperature of about 30 to 50 ° C. An additional interesting treatment involves rinsing the surface of the aluminum oxide with a bicarbonate solution. In addition, the surface of the aluminum oxide can be treated with polyvinyl phosphonic acid, polyvinylmethylphosphonic acid, polyvinyl alcohol phosphoric acid esters, polyvinyl sulfonic acid, polyvinylbenzenesulfonic acid, polyvinyl alcohol sulfuric acid esters, and polyvinyl alcohol acetals formed by reaction with a sulfonated aliphatic aldehyde.

Another useful post-anodic treatment can be carried out with a solution of polyacrylic acid or a polymer comprising at least 30 mol% of monomer units of acrylic acid, for example GLASCOL E15, a polyacrylic acid, commercially available at Ciba Specialty Chemicals.

The support can also be a flexible support, which can be provided with a hydrophilic layer, referred to as "base layer" hereinafter. The flexible support is, for example, paper, plastic film or aluminum. Preferred examples of plastic film are polyethylene terephthalate film, polyethylene naphthalate film, cellulose acetate film, polystyrene film, polycarbonate film, etc. The plastic film support can be opaque or transparent.

The base layer is preferably a crosslinked hydrophilic layer obtained from a crosslinked hydrophilic binder with a hardening agent such as formaldehyde, glyoxal, polyisocyanate or a hydrolyzed tetraalkyl orthosilicate. The latter is particularly preferred. The thickness of the hydrophilic base layer may vary in the range of 0.2 to 25 µm and is preferably 1 to 10 µm. More details of preferred embodiments of the base layer can be found in, for example, EP-A 1 025 992.

The heat sensitive plate precursor can be exposed by images directly with heat, for example by means of a thermal head, or indirectly by infrared light, preferably near infrared light. Infrared light is preferably converted to heat by an IR light absorbing compound as discussed above. Preferably, the heat sensitive lithographic printing plate precursor is not sensitive to visible light, that is, no substantial effect on the dissolution rate of the coating in the developer is induced by exposure to visible light. More preferably, the coating is not sensitive to ambient daylight.

The printing plate precursor can be exposed to infrared light by means of, for example, LEDs or a laser. More preferably, the light used for exposure is a laser that emits near-infrared light that has a wavelength in the range of about 750 to about 1,500 nm, more preferably 750 to 1,100 nm, such as a semiconductor laser diode , an Nd: YAG laser or an Nd: YLF laser. The laser power required depends on the sensitivity of the plate precursor, the residence time per pixel of the laser beam, which is determined by the point diameter (the typical value of modern recorders is 1 / e2 of the maximum intensity : 5-25 µm), the scanning speed and resolution of the exposure apparatus (i.e. the number of addressable pixels per unit of linear distance, often expressed in dots per inch or dpi; usual value: 1,000-4,000 dpi)

Two types of laser exposure devices are commonly used: internal drum recorders (ITD) and external drum recorders (XTD). ITD recorders for thermal plates are usually characterized by a very high scanning speed of up to 500 m / s and may require a laser power of several watts. XTD recorders for thermal plates that have a usual laser power of approximately 200 mW to approximately 1 W operate at a lower scan speed, for example 0.1 to 10 m / s. An XTD recorder equipped with one or more laser diodes emitting in the wavelength range between 750 and 850 nm is a particularly preferred embodiment of the method of the present invention.

Recorders known as out-of-press display devices can be used, which offers the advantage of reducing press downtime. XTD recorder configurations can also be used for press exposure, offering the advantage of immediate registration in a multicolored press. More technical details of press exposure apparatus are described, for example, in US Pat.

5,174,205 and US 5,163,368.

After exposure, the precursor is preferably revealed by immersing the precursor in a developing solution; This can be combined with a mechanical scrub, for example using a rotating brush. During development, the non-image areas of the coating are preferably removed with an aqueous alkaline developer solution. The developer solution preferably has a pH greater than 10, more preferably greater than 12. During the development stage, any water soluble layer present is also preferably removed. The development step is preferably carried out in a temperature range between 20 and 40 ° C in automated processing units as is customary in the art.

More details concerning the development step can be found, for example, in EP 1614538, EP 1614539, EP 1614540 and WO / 2004071767.

The developing solution preferably contains a buffer such as, for example, a silicate-based buffer or a phosphate buffer. The concentration of the buffer in the developer preferably ranges from 3 to 14% by weight. Advantageous are silicate-based developers that have a silicon dioxide ratio with respect to the alkali metal oxide of at least 1, because they ensure that the alumina layer of the substrate (if present) is not damaged. Preferred alkali metal oxides include Na2O and K2O, and mixtures thereof. A particularly preferred silicate-based developer solution is a developer solution comprising sodium or potassium metasilicate, that is, a silicate in which the ratio of silicon dioxide to alkali metal oxide is 1.

The developing solution may optionally contain additional components that are known in the art: other buffer substances, chelating agents, surfactants, complexes, inorganic salts, inorganic alkaline agents, organic alkaline agents, antifoaming agents, organic solvents in small amounts, that is, preferably in less than 10% by weight and more preferably in less than 5% by weight, non-reducing sugars, glycosides, colorants and / or hydrotropic agents. These components can be used alone or in combination.

To ensure stable processing with the developer solution for a long time, it is of particular importance to control the concentration of the ingredients in the developer. Therefore, a regenerating solution is often added to the developing solution, also referred to as the regenerator hereinafter. More than one regenerating solution containing different ingredients and / or different amounts of ingredients may be added to the developer solution. Alkali metal silicate solutions having alkali metal contents of 0.6 to 2.0 mol / l may be suitably used. These solutions may have the same silica / alkali metal oxide ratio as the developer (however, it is generally lower) and also optionally contain additional additives. It is advantageous that the (co) polymer of the present invention be present in the regenerator or regenerators; preferably in a concentration of at least 0.5 g / l, more preferably in a concentration ranging between 1 and 50 g / l, most preferably between 2 and 30 g / l.

The regenerating solution preferably has a pH value of at least 10, more preferably at least 11, most preferably at least 12.

The development stage may be followed by a rinse stage, a gumming stage, a drying stage and / or a post-baking stage.

Heat-sensitive printing plates can be used for conventional printing called wet offset printing, in which ink and an aqueous wetting liquid are applied to the plate. Another suitable printing method uses the so-called single fluid ink without wetting liquid. Suitable single fluid inks have been described in US 4,045,232; US 4,981,517 and US 6,140,392. In the most preferred embodiment, the single fluid ink comprises an ink phase, also referred to as a hydrophobic or oleophilic phase, and a polyol phase, as described in WO 00/32705.

The printing plate precursor of the present invention can also be used for heat-resistant treatment, for example in a PCB application (printed circuit board) as described in US 2003/0003406 A1.

Examples

1. Preparation of lithographic support.

A 0.30 mm thick aluminum sheet was degreased by immersing the sheet in an aqueous solution containing 34 g / l of sodium hydroxide at 70 ° C for 6 seconds and rinsing with demineralized water for 3.6 seconds. The sheet was then electrochemically granulated for 8 seconds using an alternating current in an aqueous solution containing 15 g / l of HCl, 15 g / l of SO42-ions and 5 g / l of Al3 + at a temperature of 37 ° C and a current density of 100 A / dm2. The aluminum foil was then stripped by etching with an aqueous solution containing 145 g / l of sulfuric acid at 80 ° C for 5 seconds and rinsing with demineralized water for 4 seconds. The sheet was subsequently subjected to anodic oxidation for 10 seconds in an aqueous solution containing 145 g / l of sulfuric acid at a temperature of 57 ° C and a current density of 25 A / dm2, then washed with demineralized water for 7 seconds and subsequently treated for 4 seconds with a solution containing 2.2 g / l of polyvinylphosphonic acid at 70 ° C, rinsed with demineralized water for 3.5 seconds and dried at 120 ° C for 7 seconds.

The support thus obtained was characterized by a surface roughness Ra of 0.35-0.40 µm (measured with an NT1100 interferometer) and an anodic weight of 3.0 g / m2.

2. Printing plate precursors PPP-1 to PPP-16.

2.1. First layer.

A first layer was coated on an aluminum substrate (described above) with a first coating solution with the composition defined in Table 1 with a wet coating thickness of 20 µm.

Table 1: Composition of the first coating solution.

Composition of the first coating solution

g

Dowanol PM (1)

270.98

THF (2)

576.55

Binder-01 (25% by weight) (3)

53.75

Crystal violet (1% by weight) (4)

58.24

Tegoglide 410 (1% by weight) (5)

5.82

(1) Propylene glycol monomethyl ether (1-methoxy-2-propanol) commercially available from Dow Chemical Company; (2) THF is tetrahydrofuran; (3) Binder-01: see preparation 2.2; (4) 1% by weight solution of Crystal Violet in Dowanol PM, Crystal Violet is commercially available from Ciba-Geigy GmbH; (5) 1% by weight solution of Tegoglide 410 in Dowanol PM; Tegoglide 410 is a copolymer of polysiloxane and poly (alkylene oxide), commercially available from Tego Chemie Service GmbH.

5 The total dry weight of the coating amounts to 0.671 g / m2. The dry weight of the ingredients in the first coating is shown in Table 2.

Table 2: Dry weight of the first coating.

Dry weight of the first coating *

mg / m2

Binder-01

660

Crystal violet

10

Tegoglide 410

one

* ingredients defined in Table 1.

2.2. Binder Preparation-01.

In a 250 ml reactor, 162 mmol of Monomer-01 (see structure below), 21.3 g (132 mmol) of benzyl acrylamide, 0.43 g (6 mmol) of acrylic acid and 103 g were added of gamma-butyrolactone and the mixture was heated to 140 ° C, while stirring at 200 rpm. A constant flow of nitrogen was passed through the reactor. After dissolution of all components, the reactor was cooled to 100 ° C. 0.35 ml of Trigonox ™ DC50 was added,

15 commercially available from AKZO NOBEL, followed by the addition of 1.39 ml of Trigonox ™ 141, commercially available from AKZO NOBEL, in 3.43 ml of butyrolactone. Polymerization was started and the reactor was heated at 140 ° C for 2 hours while 1.75 ml of Trigonox ™ DC50 was dosed. The mixture was stirred at 400 rpm and polymerization was allowed to continue for 2 hours at 140 ° C. The reaction mixture was cooled to 120 ° C and the agitator speed increased to 500 rpm. 85.7 ml of 1-methoxy-2-propanol was added and the reaction mixture was allowed to cool

20 at room temperature. Binder-01 was analyzed by 1 H NMR spectroscopy and size exclusion chromatography, using 0.21% dimethyl acetamide / LiCl as eluent in a 3x mixed column and with respect to polystyrene standards.

Mn

Mw P.S.

Binder-01

23,500 67,000 2.84

The reaction mixture was cooled to 40 ° C and the resulting 25% by weight polymer solution was collected in a drum.

Monomer-01:

2.3. Second layer.

A second coating solution was coated on the first layer with the composition defined in Table 3 (coating solutions 1 to 16) with a wet coating thickness of 16 µm resulting in the printing plate precursors PPP- 01 to PPP-16.

Table 3: Composition of the second coating solutions Table 3, continued: Composition of the second coating solutions.

Composition of the second coating solution

1ref. 2comp. 3comp. 4comp. 5comp. 6comp. 7comp. 8comp.

g

g

g

g

g

g

g

g

Dowanol PM

306.76 306.76 306.76 306.76 306.76 306.76 306.76 306.76

MEK

473.35 473.35 473.35 473.35 473.35 473.35 473.35 473.35

Alnovol SPN4 02 (1)

106.33 106.33 106.33 106.33 106.33 106.33 106.33 106.33

TMCA (2)

40.12 40.12 40.12 40.12 40.12 40.12 40.12 40.12

Adagio (3)

1.79 1.79 1.79 1.79 1.79 1, 79 1.79 1.79

Crystal Violet (4)

71.65 71.65 71.65 71.65 71.65 71.65 71.65 71.65

Tegoglide 410 (5)

- 35.85 - - - - - -

PolyFox PF-636 (6)

- - 35.85 71.65 - - - -

PolyFox PF-6520 (7)

- - - - 35.85 71.65 - -

PolyFox-PF656 (8)

- - - - - - 35.85 71.65

PolyFox-PF6320 (9)

- - - - - - - -

PolyFox-PF159N (10)

- - - - - - - -

PolyFox-PF652 (11)

- - - - - - - -

PolyFox-PF651 (12)

- - - - - - - -

Composition of the second coating solution

9comp. 10comp. 11comp. 12comp. 13inv. 14inv. 15inv. 16inv.

g

g

g

g

g

g

g

g

Dowanol PM

306.76 306.76 306.76 306.76 306.76 306.76 306.76 306.76

MEK

473 .35 473.35 473.35 473.35 473.35 473.35 473.35 473.35

Alnovol SPN4 02 (1)

106.33 106.33 106.33 106.33 106.33 106.33 106.33 106.33

TMCA (2)

40.12 40.12 40.12 40.12 40.12 40.12 40.12 40.12

Adagio (3)

1.79 1.79 1.79 1.79 1.79 1.79 1.79 1.79

Crystal Violet (4)

71.65 71.65 71.65 71.65 71.65 71.65 71.65 71.65

Tegoglide 410 (5)

- - - - - -

PolyFox PF-63 6 (6)

- - - - - - - -

PolyFox PF-6520 (7)

- - - - - - - -

PolyFox-PF656 (8)

- - - - - - - -

PolyFox-PF632 0 (9)

35.85 71.56 - - - - - -

PolyFox-PF159N (10)

_ - 35.85 71.65 - - - -

PolyFox-PF652 (11)

- - - - 35.85 71.85 - -

PolyFox-PF651 (12)

- - - - - - 35.85 71.85

1) Alnovol SPN402 is a 44.3% solution by weight of novolac resin in Dowanol PM commercially available

at Clariant GmbH.

2) 10% by weight solution of TMCA (3,4,5-trimethoxy cinnamic acid) in Dowanol PM.

3) Adagio is an IR adsorbent cyanine dye, commercially available from FEW CHEMICALS, with the

5 chemical structure IR-1 (see above).

4) 1% by weight solution of Crystal Violet in Dowanol PM, commercially available from Ciba-Geigy GmbH.

5) 1% by weight solution of Tegoglide 410 in Dowanol PM., Copolymer of polysiloxane and poly (alkylene oxide),

commercially available from TEGO Chemie Service GmbH. 6) 1% by weight solution of PolyFox PF-636 in Dowanol PM, commercially available from Omnova Solutions Inc. 10 and containing the following chemical structure:

with an average degree of polymerization in t + u number equal to approximately 6.

15 7) Solution by weight% PolyFox PF-6520 in Dowanol PM, commercially available from Omnova Solutions Inc. and containing the following chemical structure:

with an average degree of polymerization in number s + r equal to approximately 20. 8) 1% by weight solution of PolyFox PF-656 in Dowanol PM, commercially available from Omnova Solutions Inc. 20 and containing the following chemical structure :

with an average degree of polymerization in number s + r equal to approximately 6.

9) 1% by weight solution of PolyFox PF-6320 in Dowanol PM, commercially available from Omnova Solutions 25 Inc. and containing the following chemical structure:

with an average degree of polymerization in t + u number equal to approximately 20.

10) 1% by weight solution of PolyFox PF-159N in Dowanol PM, commercially available from Omnova Solutions Inc. and containing the following chemical structure:

11) 1% by weight solution of PolyFox PF-652 in Dowanol PM, commercially available from Omnova Solutions Inc. as a 50% solution in isopropanol, PolyFox PF-652 containing the following chemical structure:

5 with an average degree of polymerization in number x + and equal to approximately 10 and an average degree of polymerization in number p + q equal to approximately 17.8.

12) 1% by weight solution of PolyFox PF-651 in Dowanol PM, commercially available from Omnova Solutions Inc. 10 as a 50% solution in isopropanol containing the following chemical structure:

with an average degree of polymerization in number n equal to approximately 10 and with an average degree of polymerization in number m equal to approximately 8.9.

The total dry weight of the coating of the second coatings and their respective ingredients are shown in Table 4.

Table 4: Dry coating weight of the second coating.

Dry weight of the second coating *

mg / m2

Alnovol SPN402

653.0

TMCA

56.0

Adage

25.0

Crystal violet

10.0

Perfluoro Surfactant

5.0 or 10.0

Total:

749 or 754

* The dry coating weight of the second PPP-01 coating totaled only 744 mg / m2; The coating ingredients are defined in Table 3.

3. Exposure of printing plate precursors 1 to 16.

The image was formed on the printing plate precursors PPP-01 to PPP-16 on a Creo TrendSetter with a 40 W image formation head (commercially available in Kodak) at 140 rpm and 2,400 dpi and at

5 was then revealed on an Agfa Autolith TP105 processor (commercially available on Agfa Graphics NV) with Agfa Energy Elite developer (commercially available on Agfa Graphics NV) in the developer section (temperature 23 ° C, residence time 25 s ) and running water (room temperature) in the finishing section.

4. Evaluation of printing plate precursors 1 to 16. 10

4.1. Evaluation of the coefficient of friction.

The coefficient of static friction of the surface of the precursors was measured. A value of at least 0.45 is required to prevent the plates from moving over each other during transport, leading to defects in

15 "chafing".

The coefficient of static friction was measured in accordance with ASTM D 1894. The following experimental setup was used:

where

a: meter that measures the frictional force between d and g;

b: pulley; 25 c: nylon thread;

d: part of a usual piece separation paper (Pleiderer Pergo-Tec 37 g / m2);

e: stainless steel block;

f: support;

g: printing plate precursor with the photosensitive layer facing up.

30 The coefficient of static friction is defined as the maximum force (N) needed to move the stainless steel block e, divided by the weight of the stainless steel block.

This evaluation was carried out 5 times for each of the printing plate precursors 1 to 16. The result of this evaluation (mean value and standard deviation) is shown in Table 5.

4.2. Evaluation of the coating capacity (cosmetic).

To evaluate the strength of each of the second coating solutions with respect to the conditions of

Coating and drying, ie the coating capacity, an additional coating test was carried out on the aluminum support described in 1 with each of the coating solutions 1-16 described in 2.3 , but using very critical drying conditions:

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step 1: drying for 30 seconds under the conditions described below; 45-stage 2: drying in a hot air oven (convection) for 3 minutes at 135 ° C.

Drying conditions used in stage 1:

where a is a hair dryer (WIGO Taifun 110ch, power 1,000 W, commercially available on WIGO) used with the 5 maximum available setting of air blowing capacity 2. b is the precursor of printing plate.

After coating and drying under the conditions described above, the precursors obtained were visually evaluated for coating uniformity using the following qualitative scale:

10 1 = strongly cloudy coating 2 = cloudy coating 3 = slightly cloudy coating 4 = almost homogeneous coating

15 5 = perfectly homogeneous coating

A value of at least 4 of the cosmetic or surface coating capacity is required to be able to coat the layer with sufficient flexibility under industrial conditions.

20 4.3. Evaluation of sensitivity to correct exposure.

The correct exposure sensitivity (RE) is the energy density value (in mJ / cm2) in which the 1 x 1 checkerboard pattern of the plate after processing reads 52% (Gretag-MacBeth D19C densitometer, automatic color filter adjustment).

25 The results of the evaluations of sensitivity to correct exposure (RE), cosmetic level / coating capacity and friction coefficient are given in Table 5.

Table 5: Results of static friction coefficient and sensitivity.

Print Plate Precursor

Sensitivity to "RE" (mJ / cm2) Coefficient of static friction * Coating Cosmetics ** Dry weight of surfactant coating (mg / m2)

PPP 1; reference

111 0.60 ∀ 0.008 2 -

PPP 2; comparative

109 0.16 ∀ 0.009 5 5.0

PPP 3; comparative

na na one 5.0

PPP 4; comparative

na na one 10.0

PPP 5; comparative

98 0.36 ∀ 0.019 4 5.0

PPP 6; comparative

84 0.31 ∀ 0.010 4,5 10.0

PPP 7; comparative

na na 3 5.0

PPP 8; comparative

na na 3 10.0

PPP 9; comparative

83 0.46 ∀ 0.023 one 5.0

Print Plate Precursor

Sensitivity to "RE" (mJ / cm2) Coefficient of static friction * Coating Cosmetics ** Dry weight of surfactant coating (mg / m2)

PPP 10; comparative

101 0.33 ∀ 0.016 one 10.0

PPP 11; comparative

na na one 5.0

PPP 12; comparative

na na one 10.0

PPP 13; invention

97 0.58 ∀ 0.002 5 5.0

PPP 14; invention

88 0.57 ∀ 0.004 4 10.0

PPP 15; invention

108 0.56 ∀ 0.008 4,5 5.0

PPP 16; invention

99 0.48 ∀ 0.008 4 10.0

na = data not available; * determined as described above; ** coating uniformity visually evaluated using the following qualitative scale 1 = strongly cloudy coating 2 = cloudy coating 3 = slightly cloudy coating 4 = almost homogeneous coating 5 = perfectly homogeneous coating

The results in Table 5 show that comparative printing plates have poor coating capacity results (i.e. coating cosmetic level of 1 to 3), or, when the coating capacity is acceptable, that is, A coating cosmetic level of at least 4, the coefficient of static friction is not high enough (less than 0.45).

The printing plate precursors of the present invention comprising the surfactants PolyFox PF652 and PolyFox PF-651, PPP-13 to PPP-16, have a good coating capacity - that is a level of

10 cosmetic coating at least 4 - and at the same time a coefficient of static friction sufficiently high - that is a coefficient of static friction of at least 0.45. PolyFox PF-652 has the additional characteristic that it shows a very consistent behavior throughout the concentration range used.

15 Sensitivity results are comparable for all PPP-1 to PPP printing plate precursors

16.

Claims (11)

1. Precursor of lithographic printing plate in heat-sensitive positive process comprising on a support of granulated and anodized aluminum having a hydrophilic surface or which is provided with a layer 5 hydrophilic and having an anodic weight between 1 and 4 g / m2, a heat and / or light sensitive coating comprising a surfactant, characterized in that the surfactant comprises a polyether block that includes a fluoroalkyl side group and a group urethane binding. 2. Printing plate precursor according to claim 1 wherein the anodic weight is between 1 and 3.5 10 g / m2. 3. Printing plate precursor according to any of the preceding claims wherein the fluoroalkyl group is an alkoxyfluoroalkyl group. 4. Printing plate precursor according to any of the preceding claims wherein the surfactant comprises the following structural unit: 20 where a and b independently represent an integer ≥ 0; c represents an integer that varies between 1 and 40; Y1 represents a fluoroalkyl group or an alkoxyfluoroalkyl group; Y2 represents hydrogen, an optionally substituted alkyl group, a fluoroalkyl group or an alkoxyfluoroalkyl group; R1 to R4 independently represent hydrogen, fluoride, a fluoroalkyl group, an alkyl group optionally substituted or an optionally substituted aryl group. 5. Precursor according to any of the preceding claims wherein the surfactant comprises the following structural unit: where d and e represent an integer ≥ 0; X represents a fluoroalkyl group; Y3 represents hydrogen or an optionally substituted alkyl group; and f represents an integer that varies between 1 and 40. 6. Printing plate precursor according to any of the preceding claims wherein the surfactant comprises the following structural unit: where R5 represents hydrogen; an optionally substituted alkyl group or an optionally substituted aryl, aralkyl or heteroalkyl group; and k represents an integer that varies between 1 and 40. 7. Printing plate precursor according to any of the preceding claims wherein the surfactant comprises the following structural unit: I where m, n, o and p in each of the compounds independently represent an integer that varies between 1 and 40. 8. Printing plate precursor according to any of the preceding claims wherein the surfactant is one of the following compounds: where m, n, o, p, x, y, q and v in each of the compounds independently represent an integer that varies between 1 and 40. 9. Printing plate precursor according to any of the preceding claims wherein the surfactant is present in the coating in an amount ranging from 0.1% by weight to 3% by weight. 10. Printing plate precursor according to any of the preceding claims wherein the coating comprises at least two layers

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a layer comprising an oleophilic resin;

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another layer comprising a sulfonamide binder, which is located between the support and said layer comprising the oleophilic resin;

and where the surfactant is present in the layer comprising the oleophilic resin. 11. Printing plate precursor according to claim 10 wherein the sulfonamide binder is represented by 5 where R9 represents hydrogen or a hydrocarbon group having up to 12 carbon atoms; X1 represents a single bond or a divalent linking group; Y4 is a divalent sulfonamide group; 10 and Z1 represents a terminal group. 12. Method for manufacturing a lithographic printing plate precursor according to any of the preceding claims comprising the steps of 15 - applying a coating as defined in any of the preceding claims; -dry the precursor. 13. Method for the manufacture of a lithographic printing plate comprising the steps of 20 - providing a printing plate precursor according to any of the preceding claims; - exposing said precursor to heat and / or infrared light; - reveal the exposed precursor with an aqueous alkaline solution.