WO2005029187A1 - Photopolymerizable composition. - Google Patents

Photopolymerizable composition. Download PDF

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Publication number
WO2005029187A1
WO2005029187A1 PCT/EP2004/051987 EP2004051987W WO2005029187A1 WO 2005029187 A1 WO2005029187 A1 WO 2005029187A1 EP 2004051987 W EP2004051987 W EP 2004051987W WO 2005029187 A1 WO2005029187 A1 WO 2005029187A1
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WO
WIPO (PCT)
Prior art keywords
composition according
group
printing plate
sensitizer
atom
Prior art date
Application number
PCT/EP2004/051987
Other languages
French (fr)
Inventor
Marc Vandamme
Paul Callant
Original Assignee
Agfa-Gevaert
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Agfa-Gevaert filed Critical Agfa-Gevaert
Priority to DE602004021120T priority Critical patent/DE602004021120D1/en
Priority to EP04766667A priority patent/EP1668417B1/en
Priority to CN2004800340559A priority patent/CN1882879B/en
Priority to US10/573,193 priority patent/US7527916B2/en
Publication of WO2005029187A1 publication Critical patent/WO2005029187A1/en

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Classifications

    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
    • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
    • G03F7/004—Photosensitive materials
    • G03F7/027—Non-macromolecular photopolymerisable compounds having carbon-to-carbon double bonds, e.g. ethylenic compounds
    • G03F7/028—Non-macromolecular photopolymerisable compounds having carbon-to-carbon double bonds, e.g. ethylenic compounds with photosensitivity-increasing substances, e.g. photoinitiators
    • G03F7/031—Organic compounds not covered by group G03F7/029
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F2/00—Processes of polymerisation
    • C08F2/46—Polymerisation initiated by wave energy or particle radiation
    • C08F2/48—Polymerisation initiated by wave energy or particle radiation by ultraviolet or visible light
    • C08F2/50—Polymerisation initiated by wave energy or particle radiation by ultraviolet or visible light with sensitising agents

Definitions

  • the present invention relates to a photopolymerizable composition which is sensitized for the wavelength range from 300 to 450 nm and which comprises an optical brightening agent as sensitizer.
  • the invention also relates to a printing plate precursor comprising said composition and a method for making a printing plate therewith.
  • a so-called printing master such as a printing plate is mounted on a cylinder of the printing press.
  • the master carries a lithographic image on its surface and a printed copy is obtained by applying ink to said image and then tansferring the ink from the master onto a receiver material, which is typically paper.
  • aqueous fountain solution also called dampening liquid
  • ink as well as an aqueous fountain solution are supplied to the lithographic image which consists of oleophilic (or hydrophobic, i.e. ink-accepting, water-repelling) areas as well as hydrophilic (or oleophobic, i.e. water- accepting, ink-repelling) areas.
  • the lithographic image consists of ink-accepting and ink-abhesive (ink-repelling) areas and during driographic printing, only ink is supplied to the master.
  • Printing masters are generally obtained by the so-called computer-to-film (CtF) method wherein various pre-press steps such as typeface selection, scanning, color separation, screening, tapping, layout and imposition are accomplished digitally and each color selection is transferred to graphic arts film using an image-setter.
  • CtF computer-to-film
  • the film can be used as a mask for the exposure of an imaging material called plate precursor and after plate processing, a printing plate is obtained which can be used as a master.
  • CtP computer-to-plate'
  • This method also called 'direct-to-plate', bypasses the creation of film because the digital document is transferred directly to a plate precursor by means of a so-called plate-setter.
  • a plate precursor for CtP is often called a digital plate.
  • Digital plates can roughly be divided in three categories : (i) silver plates, which work according to the silver salt diffusion transfer mechanism; (ii) photopolymer plates which contain a photopolymerizable composition that hardens upon exposure to light and (iii) thermal plates of which the imaging mechanism is triggered by heat or by light-to-heat conversion.
  • Thermal plates are mainly sensitized for infrared lasers emitting at 830 nm or 1064 nm.
  • Typical photopolymer plates are sensitized for visible light, mainly for exposure by an Ar laser (488 nm) or a FD-Y ⁇ G laser (532 nm).
  • Ar laser 488 nm
  • FD-Y ⁇ G laser 532 nm
  • the wide-scale availability of low cost blue or violet laser diodes, originally developed for data storage by means of DVD, has enabled the production of plate-setters operating at shorter wavelength. More specifically, semiconductor lasers emitting from 350 to 450 nm have been realized using an InGaN material. Photopolymer plates sensitized for the wavelength range from 350 to 450 nm have also been described in the prior art.
  • Photopolymer plates generally contain a polymerizable monomer, a binder, a photoinitiator and a sensitizing dye.
  • EP-A 985683 describes a composition comprising a titanocene compound as photoinitiator and specific dyes as sensitizers for the wavelength range from 350 to 450 nm.
  • EP- ⁇ 1035435 discloses a 1,3- dihydro-l-oxo-2H-indene derivative as sensitizing dye.
  • EP- ⁇ s 1048982 and 1070990 also discloses certain dyes in combination with a titanoccne photoinitiator. ⁇ wide range of dyes for the wavelength range from 300 to 1200 nm is disclosed in EP-A 1091247.
  • the sensitizing dyes disclosed in the prior art do not produce sufficient speed (sensitivity) to enable a short exposure time with the commercially available blue or violet laser diodes.
  • Typical low-cost blue or violet laser diodes have a light output characterized by low power.
  • the known photopolymer printing plate precursors are unsatisfactory, because they result in printing plates of minor or even unacceptable quality because of so called pinhole defects, that have an irregular crystal-like shape. Defects called pinholes are areas having lateral dimensions of about 50 to 500 ⁇ m on the processed printing plate, that don't take up ink and therefore result in exposed areas that don't print. This unfavourable effect is particularly noticeable, if the printing plate precursor is stored before exposure and processing thereof.
  • a printing plate precursor according to the present invention is obtained that is sensitive to the wavelength range from 300 to 450 nm.
  • the printing plate precursor of the present invention is a flexographic or lithographic printing plate precursor, the latter being highly preferred. Also a method of making a printing plate wherein said printing plate precursor is exposed with a laser having an emission in the wavelength range from 300 to 450 nm, is an aspect of the present invention.
  • Preferred photopolymer plate precursors according to the present invention can be exposed with an energy density, measured on the surface of the plate of 100 ⁇ J/cm 2 or less.
  • Preferred embodiments of the composition, of the printing plate precursor, of the method of making a printing plate and of the use according to the present invention are defined in the dependent claims.
  • the present invention relates to a composition (photopolymerizable composition) that is photopolymerizable upon absorption of light in the wavelength range from 300 to 450 nm, preferably from 350 to 430 nm and particularly preferred from 360 to 420 nm, the composition comprising a binder, a polymerizable compound, a sensitizer and a photoinitiator, characterized in that the sensitizer is an optical brightening agent having a solubility in methyl ethyl ketone of at least 15 g/kg measured at 20°C.
  • the sensitizer has a great influence on the tendency that pinholes appear, the most important factor being the solubility of the sensitizer in methyl ethyl ketone.
  • a sensitizer having a solubility in methyl ethyl ketone of at least 15 g/kg measured at 20°C only an acceptable amount of pinholes appears, and preferred sensitizers 5 have a solubility in methyl ethyl ketone of from 15 to 250 g/kg measured at 20°C.
  • optical brightening agents are preferred sensitizers for printing plate precursor of the present invention and allow, in combination with the solubility disclosed above, to prepare printing plates that are elichially free from pinholes and even ⁇ o completely free of pinholes.
  • the sensitizing dyes of the present invention have a good compatibility with the other ingredients of the photopolymerisable layer and therefor don't induce the creation of pinholes.
  • a typical optical brightener also known as "fluorescent whitening agenf , is a is colorless to weakly colored organic compound that is capable of absorbing light having a wavelength in the range between 300 and 450 nm and of emitting the absorbed energy as fluorescent light having a wavelength in the range between 400 and 500 nm.
  • suitable optical brightener contain ⁇ -elechon systems comprising a carbocyclic or a heterocyclic nucleus. Suitable representatives of these compounds are e. g.
  • stilbenes distyrylbenzenes, distyrylbiphenyls, divinylstilbenes, triazinylaminostilbenes, stilbenyltriazoles, stilbenylnaphthotriazoles, bis-triazolstilbenes, benzoxazoles, bisphenylbenzoxazoles, stilbenylbenzoxazoles, bis-benzoxazoles, furans, benzofurans, bis- 25 benzimidazoles, diphenylpyrazolines, diphenyloxadiazoles, coumarins, naphthalimides, xanthenes, carbostyrils, pyrenes and 1,3,5-triazinyl-derivatives. More specifically, optical brightening agents having a structure according to one of the following formulae are preferred sensitizers for use in the composition of the present invention :
  • optical brighteners can be used as a single compound or as a mixture of several materials. The overall amount of these compounds ranges from 0.1 to 10 % by weight- preferably 0.5 to 8 % by weight with respect to the total weight of the non-volatile compounds in the composition.
  • Highly preferred optical brighteners include compounds of formulae (III) and/or (IV), and in particular compounds of formulae (Ilia) and/or (Wa):
  • R 1 to R in dependently represent a hydrogen atom, an alkyl group, an alkoxy group, a cyano group or a halogen atom, and at least one of R 1 to R 10 represents an alkoxy group having more than 1 carbon atom;
  • R 15 to R 32 independently represent a hydrogen atom, an alkyl group, an alkoxy group, a is cyano group or a halogen atom, and at least one of R 15 to R 24 represents an alkoxy group having more than 1 carbon atom.
  • the alkyl and alkoxy groups of the present invention can be optionally substituted and their substituent can be selected to adjust the solubility of the sensitizer and may be, for example, p.o halogen, ester, ether, thioether or hydroxy.
  • the alkyl or alkoxy groups may be shaight chain or cyclic, but a branched chain is preferred for the sensitizers of formulae (Ilia) and (IVa).
  • sensitisers of formula (Ilia) wherein R 1 , R 5 , R 6 , R 10 , R 11 , R 12 , R 13 and R 14 independently represent a hydrogen atom, a fluorine atom or a chlorine atom, in particular R 1 , R 5 , R 6 , and R 10 being a hydrogen atom; R 2 to R 4 , R 7 to R 9 , independently are alkoxy groups; and at least two of the alkoxy groups are branched and have from 3 to 15 carbon atoms.
  • sensitizers of formulae (Ilia) as disclosed above wherein R 2 , R 4 , R 7 , R 9 independently represent a methoxy group and R 3 and R 8 independently are branched alkoxy groups having 3 to 15 carbon atoms.
  • sensitizers of formulae (IVa) as disclosed above wherein R 16 , R 18 , R , R independently represent a methoxy group and R andR independently are branched alkoxy groups having 3 to 15 carbon atoms.
  • sensitizers of the present invention are examples of preferred sensitizers of the present invention and their solubility S is given in brackets as g sensitizer/kg methyl ethyl ketone measured at 20°C.
  • sensitizers useful for the present invention can be synthesised by known methods and the synthesis of the highly preferred sensitizers of formulae (Ilia) and ( IVa) can be done in analogy to the synthesis of sensitizer (III-l) as disclosed in the following. Synthesis of intermediate (C-3)
  • C-4 A suitable synthesis for the p-xylylene-bis-phosphonate (C-4) is known from the literature, e.g. from B.P. Lugovkin andB.A. Arbuzov, Doklady Akademii Nauk SSSR (1948), 59, pages 1301 to 1304.
  • the known photopolymerization initiators can be used in the composition of the 5 present invention.
  • Suitable classes include aromatic ketones, aromatic onium salts, organic peroxides, thio compounds, hexaarylbisimidazole compounds, ketooxime ester pounds, borate compounds, azinium compounds, metallocene compounds, active ester compounds and compounds having a carbon-halogen bond.
  • photoinitiators can be found in EP-A 1091247.
  • the best results, in particular the highest sensitivity, can be ⁇ o obtained by the combination of an optical brightener as sensitizer and a hexaarylbisimidazole (HABI, dimer of triaryl-imidazole) as photoinitiator.
  • HABI hexaarylbisimidazole
  • a procedure for the preparation of HABIs is described in DE 1470 154 and their use in photopolymer-izable compositions is documented in EP 24 629, EP 107 792, US 4 410 621, EP 215 453 and DE 3 211 312.
  • Preferred derivatives are e. g.
  • the amount of the HABI photoinitiator typically ranges from 0.01 to 30 % by weight, preferably from 0.5 to 20 % by weight, relative to the total weight of the non volatile
  • the binder can be selected from a wide series of organic polymers. Compositions of different binders can also be used. Useful binders include for example chlorinated polyalkylenes in particular chlorinated polyethylene and chlorinated polypropylene; poly(methacrylic acid) alkyl esters or alkenyl esters in particular poly(methyl (meth)acrylate),
  • binders that are insoluble in water, but on the other hand are soluble or at least swellable in aqueous-alkaline solutions.
  • Further effective binders are polymers that are soluble in common organic coating solvents.
  • Particular suitable for the purpose of the present invention are binders containing carboxyl groups, in particular polymers or copolymers containing monomeric units of ⁇ , ⁇ - unsaturated carboxylic acids and/or monomeric units of ⁇ , ⁇ -unsaturated dicarboxylic acids, preferably acrylic acid, methacrylic acid, crotonic acid, vinylacetic acid, maleic acid or itaconic acid.
  • copolymers are to be understood in the context of the present invention polymers containing units of at least 2 different monomers, thus also terpolymers and higher mixed polymers.
  • Particular useful examples of copolymers are those containing units of (meth)acrylic acid and units of alkyl (meth)acrylates, allyl (meth)acrylates and/or (meth)acrylonitrile as well as copolymers containing units of crotonic acid and units of alkyl (meth)acrylates and/or (meth)acrylonitrile and vinylacetic acid/alkyl (meth)acrylate copolymers.
  • copolymers containing units of maleic anhydride or maleic acid monoalkyl esters are also suitable.
  • copolymers containing units of maleic anhydride and styrene, unsaturated ethers or esters or unsaturated aliphatic hydrocarbons and the esterification products obtained from such copolymers are, for example, copolymers containing units of maleic anhydride and styrene, unsaturated ethers or esters or unsaturated aliphatic hydrocarbons and the esterification products obtained from such copolymers.
  • Further suitable binders are products obtainable from the conversion of hydroxyl-containing polymers with intramolecular dicarboxylic anhydrides.
  • Further useful binders are polymers in which groups with acid hydrogen atoms are present, some or all of which are converted with activated isocyanates. Examples of these polymers are products obtained by conversion of hydroxyl-containing polymers with aliphatic or aromatic sulfonyl isocyanates or phosphinic acid isocyanates.
  • polymers with aliphatic or aromatic hydroxyl groups for example copolymers containing units of hydroxyalkyl (meth)acrylates, ally] alcohol, hydroxystyrene or vinyl 5 alcohol, as well as epoxy resins, provided they carry a sufficient number of free OH groups.
  • the organic polymers used as binders have a typical mean molecular weight M w between 600 and 200 000, preferably between 1 000 and 100 000. Preference is further given to polymers having an acid number between 10 to 250, preferably 20 to 200, or a hydroxyl number between 50 and 750, preferably between 100 and 500.
  • the amount of binder(s) O generally ranges from 10 to 90 % by weight, preferably 20 to 80 % by weight, relative to the total weight of the non-volatile components of the composition.
  • the polymerizable compound can be selected from a wide series of photo-oxidizable compounds. Suitable compounds contain primary, secondary and in particular tertiary amino groups. Radically polymerizable compounds containing at least one urethane and/or urea
  • urea group has to be understood in the context of the present invention a group of the formula >N-CO-N ⁇ , wherein the valences on the nihogen atoms are saturated by hydrogen atoms and hydrocarbon radicals (with the proviso that not more than one valence on either of the two nitrogen atoms is saturated by one hydrogen atom).
  • valence on one of the nihogen atoms are saturated by hydrogen atoms and hydrocarbon radicals (with the proviso that not more than one valence on either of the two nitrogen atoms is saturated by one hydrogen atom).
  • hydrocarbon radicals with the proviso that not more than one valence on either of the two nitrogen atoms is saturated by one hydrogen atom.
  • Particularly suitable compounds are monomers containing photo-oxidizable groups corresponding to the following formula (XVIII):
  • R represents an alkyl group having 2 to 8 carbon atoms ((C 2 - ) alkyl group), a (C 2 -C 8 ) hydroxyalkyl group or a (C 6 -C 1 ) aryl group,
  • Q represents -S-, — N I , — N I E — N I or wherein 5 E represents a divalent saturated hydrocarbon group of 2 to 12 carbon atoms, a divalent 5- to 7-membered, saturated iso- or heterocyclic group, which may contain up to 2 nitrogen, oxygen and/or sulfur atoms in the ring, a divalent aromatic mono- or bicyclic isocyclic group of 6 to 12 carbon atoms or a divalent 5- or 6-membered aromatic heterocyclic group; andO D 1 and D 2 independently represent a saturated hydrocarbon group of 1 to 5 carbon atoms, R 1 and R 2 independently represent a hydrogen atom, an alkyl or alkoxyalkyl group, R 3 represents a hydrogen atom, a methyl or ethyl group, X 1 represents a shaight-chained or branched saturated hydrocarbon group of 1 to 12 carbons atoms, X 2 represents a (c-H)-valent hydrocarbon group in which up to 5 m
  • Aryl radicals R are in general mononuclear or binuclear, preferably however mononuclear, and may be substituted with ( -C 5 ) alkyl or (C1-C 5 ) alkoxy groups. If R 1 and R 2 are alkyl or alkoxy groups, they preferably contain 1 to 5 carbon atoms. R 3 is preferably a hydrogen atom or a methyl group. X 1 is preferably a straight-chained or 5 branched aliphatic and/or cycloaliphatic radical of preferably 4 to 10 carbon atoms.
  • X 2 contains 2 to 15 carbon atoms and is in particular a saturated, straight-chained or branched aliphatic and or cycloaliphatic radical containing this amount of carbon atoms. Up to 5 methylene groups in these radicals may have been replaced by oxygen atoms; in the case of X 2 being composed of pure carbon chains, the radical generally has 2 to O 12 carbon atoms, preferably 2 to 6 carbon atoms. X 2 can also be a cycloaliphatic group of 5 to 10 carbon atoms, in particular a cyclohexane diyl group.
  • the saturated heterocyclic ring formed by D 1 , D 2 and both nitrogen atoms generally has 5 to 10 ring members in particular 6 ring members.
  • the heterocyclic ring is preferably a piperazine and the radical derived therefrom a piperazine- 1 ,4-diyl radical.
  • radical E is an alkane diyl group which normally contains about 2 to 6 carbon atoms.
  • the divalent 5- to 7-membered, saturated, isocyclic group E is a cyclohexane diyl group, in particular a cyclohexane- 1 ,4-diyl group.
  • the divalent, isocyclic, aromatic group E is preferably an ortho-, meta- or para-phenylene group.
  • the divalent 5- or 6-membered aromatic heterocyclic group E finally, contains preferably nihogen and/or sulphur atoms in the heterocyclic ring, c is
  • each radical in the square bracket generally contains only one polymerizable group, in particular only one (meth)acryloyloxy-group.
  • triethanolamine tris(2-hydroxypropyl)amine, tris(2-hydroxybutyl)amine and alkyl-bis- hydroxyalkylamines.
  • the hydroxy-containing esters used are preferably hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate and hydroxyisopropyl (meth)acrylate.
  • a preferred isocyanate-containing ester is isocyanoto-ethyl (meth)acrylate.
  • Further polymerizable compounds comprising photooxidisable groups suitable for the purpose of the invention are compounds according to the following formula (XIX):
  • Q' represents — > Ij , D 3 wherein D 1 and D 2 indepently represent a saturated hydrocarbon group of 1 to 5 carbon atoms and D 3 represents a saturated hydrocarbon group of 4 to 8 carbon atoms, which together with the nihogen atom forms a 5- or 6-membered heterocyclic ring;
  • X 1 represents -CjH 2 i- or
  • X 2 represents a divalent hydrocarbon group in which up to 5 methylene groups may be replaced by oxygen atoms.
  • index a is preferably 0 or 1 and i preferably represents a number between 2 and 10.
  • the amount of polymerizable compound comprising photooxidisable groups generally ranges from 5 to 75 % by weight, preferably from 10 to 65 % by weight, relative to the total weight of the non volatile compounds of the photopolymerizable composition.
  • the composition can contain polyfunctional (meth)acrylate or alkyl(meth)acrylate compounds as crosslinking agents.
  • Such compounds contain more than 2, preferably between 3 and 6 (meth)acrylate and/or alkyl(meth)acrylate groups and include in particular (meth)acrylates of saturated aliphatic or alicyclic trivalent or polyvalent alcohols such as trimethylol ethane, himethylol propane, pentaerythritol or dipentaeiythritol.
  • the total amount of polymerizable compounds generally ranges from about 10 to 90 % by weight, preferably from about 20 to 80 % by weight, relative to the total weight of the non volatile components of the photopolymerizable composition of the present invention.
  • the following specific example is also a suitable polymerizable compound :
  • a radical chain transfer agent as described in EP 107 792 to the photopolymerizable composition of the present invention.
  • the preferred chain t ⁇ nsfer agents are sulfur containing compounds, especially thiols like e. g. 2-mercaptobenzothiazole, 2-mercaptobenzoxazole or 2-mercapto- benzimidazole.
  • the amount of chain transfer agent generally ranges from 0.01 to 10 % by weight, preferably from 0.1 to 2 % by weight, relative to the total weight of the non volatile components of the photopolymerizable composition.
  • pigments e.g. predispersed phthalocyanine pigments
  • Their amount generally ranges from about 1 to 15 % by weight, preferably from about 2 to 7 % by weight related to the total weight of the non volatile components of the composition.
  • Particularly suitable predispersed phthalocyanine pigments are disclosed in DE
  • the present invention also relates to a photopolymer printing plate precursor comprising a layer (photopolymerizable layer) containing the photopolymerizable composition of the present invention on a support.
  • the photopolymerizable composition according to the present invention is applied to the support by processes which are known per se to the person skilled in the art.
  • the components of the photopolymerizable composition are dissolved or dispersed in an organic solvent or solvent mixture, the solution or dispersion is applied to the intended support by pouring on, spraying on, emersion, roll application or in a similar and the solvents are removed during the subsequent drying.
  • the known supports can be used for the photopolymer printing plate of the present invention, like e. g. foils, tapes or plates made of metal or plastics and in the case of screen- printing also of Perlon gauze.
  • Preferred metals are aluminium, aluminium alloys, steel and zinc, aluminium and aluminium alloys being particularly preferred.
  • Preferred plastics are polyester and cellulose acetates, polyethylcneterephthalate (PET) being particularly preferred.
  • PET polyethylcneterephthalate
  • the most preferred support to be used for the present invention is made of aluminium or an aluminium alloy, its surface is electrochemically roughened, thereafter anodize and optionally heated with a hydrophilizing agent like e. g. poly(vinylphosphonic acid).
  • the printing plate precursors of the present invention preferably have a protective layer (overcoat layer) provided on top of the photopolymerizable layer.
  • Said protective layer may contain the ingredients known in the art, in particular water soluble polymers like poly(vinyl alcohols) or poly(vinyl pyrrolidone), surface wetting agents, coloring agents, complexants and biocides. Among said complexants, ethoxylated ethylene diamine compounds have been found to be particularly preferred for the present invention.
  • the protective overcoat according to the present invention comprises at least one type of poly(vinyl alcohol), wherein the mean degree of saponification is less than 93 mol-%. The degree of saponification is related to the production of poly(vinyl alcohols).
  • poly(vinyl alcohol) As 5 the monomer of poly(vinyl alcohol), vinyl alcohol, is nonexistent, only indirect methods are available for the production of poly(vinyl alcohol). The most important manufacturing process for poly(vinyl alcohol) is the polymerization of vinyl esters or ethers, with subsequent saponification or transesterification.
  • the preferred starting material for the poly (vinyl alcohol) of the present invention is a vinyl alcohol esterified by a mono carboxylic acid and in
  • the degree of saponification as defined for the present invention is the molar degree of hydrolysis irrespective of the process used for the hydrolysis.
  • Pure poly (vinyl alcohol) has e. g. a degree of saponification of 100 mol-%, but commercial products often have a degree of saponification of 98 mol-%.
  • the poly(vinyl alcohol) has e. g. a degree of saponification of 100 mol-%, but commercial products often have a degree of saponification of 98 mol-%.
  • J5 alcohols) as preferably used for the present invention contain mainly 1,3-diol units, but may also contain small amounts of 1,2-diol units.
  • the ester or the ether group can be distributed statistically or blockwise.
  • Preferred partially saponified poly(vinyl alcohols) of the present invention have a viscosity of a 4 % aqueous solution at 20°C of 4 to 60 mPa » s, preferably of 4 to 20 mPa » s and in particular of 4 to 10
  • Mowiol 8 - 88 or Mowiol 8/88 mean a poly(vinyl alcohol) having as 4 % aqueous solution at 20°C a viscosity
  • poly(vinyl alcohols) differing in viscosity as defined above and/or in saponification degree are combined.
  • Particularly preferred are mixture of poly(vinyl alcohols) that differ in viscosity of their 4 % aqueous solutions at 20°C for at least 2 mPa»s or that differ in saponification degree for at least 5 mol-%.
  • the overall mean saponification degree of all poly(vinyl alcohols) used in the protective layer has to be less than 93 mol-%.
  • said overall mean saponification degree ranges from 71 mol-% to less than 93 mol-% and in particular from 80 mol-% to 92,9 mol-%.
  • the overall mean saponification degree of the poly(vinyl alcohols) used in the protective overcoat of a printing plate precursor can be determined experimentally via 13 C- NMR.
  • To measure the I3 C-NMR spectra approximately 200 mg of the protective overcoat are O dissolved in 1.0 ml DMSO and from this solution a 75 MHz 13 C-NMR spectrum is taken, whose resonances can easily be interpreted and allow to calculate the degree of saponification (experimental values).
  • a good correlation is obtained between said experimental values and the values known from the product specification of the poly(vinyl alcohols).
  • the latter values are hereinafter called theoretical values of the mean saponification degree and can easily be
  • poly(vinyl alcohol) of the present invention is used in 50 to 99.9 weight percent (wt.%) relative to the total weight of the non- volatile compounds of the protective overcoat.
  • water soluble polymers can be added to the layer such as poly(vinyl pyrrolidonc), poly(ethylene oxide), gelatin, gum arabic, oxygen binding polymers
  • aliphatic amine groups known from EP 352 630 Bl , methyl vinylcthcr/maleic anhydride copolymers, poly(carboxylic acids), copolymers of ethylene oxide and poly(vinyl alcohol), carbon hydrates, hydroxy ethyl cellulose, acidic cellulose, cellulose, poly(arylic acid) and mixtures of these polymers.
  • the ⁇ oly(vinyl pyrrolidone) is only used in small quantities compared to the
  • poly(vinyl alcohol) is used from 0 to 10 parts by weight of the poly(vinyl alcohol) used, from 0 to 3 parts by weight being particularly preferred. Most preferred no poly(vinyl pyrrolidone)compounds are used.
  • poly(vinyl alcohol) of the present invention and the optional
  • the protective layer has to be transparent for actinic light and preferably has a dry thickness of 0.2 to 10 g/m 2 , 1.0 to 5 g m 2 beeing particularly preferred.
  • it is homogeneous, substantially impermeable to oxygen, waterpermeable, and can be washed off preferably with the conventional developer solutions used to form a printing relief after imagewise exposure of the photosensitive layer.
  • Said photopolymerizable layer is removed imagewise, whereas the protective layer is removable over the entire area of the element created.
  • the wash-off of the protective layer can be done in a separate step, but can be done during the development step as well.
  • the protective layer can be coated on the photosensitive layer with known techniques and the coating solution preferably contains water or a mixture of water and an organic solvent. To allow a better wetting, the coating solution preferably contains, related to the solid content, up to 10 wt.%, and particular preferred up to 5 wt.% of a surface active agent.
  • Suitable representatives of surface active agents comprise anionic, cationic and nonionic surface active agents like sodium alkylsulfates and -sulfonates having 12 to 18 carbon atoms, an example of which is sodium dodecylsulfate, N-cetyl- and C-cetyl betaine, alkylaminocarboxylate and -dicarboxylate, and polyethylene glycols with a mean molar weight up to 400.
  • further functions can be added to the protective layer. For example, it can be possible to improve the safelight suitability without decreasing the sensitivity of the layer by adding a coloring agent, e. g.
  • the present invention also relates to a method of making a lithographic printing plate comprising the steps of providing a photopolymer printing plate precursor of the present invention, exposing said printing plate precursor with a laser having an emission wavelength in the range from 300 to 450 nm and processing the printing plate precursor in an aqueous alkaline developer.
  • the exposure is done with a laser having an emission wavelenth in the range from 380 to 430 nm, in particular in the range from 390 to 420 nm, and the exposure is carried out at an energy density, measured on the surface of the plate, of 100 ⁇ J/cm 2 or less.
  • the processing of the printing plate precursor of the present invention is done in the usual manner. After image-wise exposure a pre-heat step is performed to improve the crosslinking of the photosensitive layer. Usually the pre-heat step is then followed by the development step, wherein the complete overcoat layer and the unexposed part of the photosensitive layer are removed.
  • the removal (wash-off) of the overcoat layer and the development of the photosensitive layer can be done in two seperate steps in this order, but can also be done in one step simultaneously.
  • the overcoat layer is washed-off with water before the development step. What remains on the support after the development step are the exposed and thereby photopolymerized parts of the photosensitive layer.
  • the developer solution used for the development of the exposed printing plate precursors of the present invention preferably is an aqueous alkaline solution having a pH of at least 11, a pH from 11.5 to 13.5 being particularly preferred.
  • the developer solution can contain a small percentage, preferably less than 5 wt.%, of an organic, water-miscible solvent.
  • an alkali hydroxide is preferably used.
  • additional ingredients of the developer solution comprise alone or in combination alkali phosphates, alkali carbonates, alkali bicarbonates, an organic amine compound, alkali silicates, buffering agents, complexants, defoamers, surface active agents and dyes, but the suitable ingredients are not limited to the preferred examples and further ingredients can be used.
  • the method of development employed is not particularly limited, and may be conducted by soaking and shaking the plate in a developer, physically removing non-image portions while being dissolved in a developer by means of e. g. a brush, or spraying a developer onto the plate so as to remove non-image portions.
  • the time for development is selected depending upon the above method used so that the non-image portions can adequately by removed, and is optionally selected within a range of 5 seconds to 10 minutes.
  • the plate After the development, the plate my be subjected to a hydrophilic treatment by means of, e. g., gum arabic optionally applied to the printing plate as the case requires (gumming step).
  • Examples 1 to 6 and comparative examples 1 and 2 Solubility test in methyl ethyl ketone 1.5 g of the sensitiser is dissolved in 100 g of methyl ethyl ketone and allowed to stir at room temperature (20°C) for a maximum of 24 hours. If the sensitiser is completely dissolved in the methyl ethyl ketone, the sensitiser passes the solubility test and is considered as a preferred sensitiser according to the present invention.
  • This composition was coated on an electrochemically roughened and anodically oxidized aluminum sheet, the surface of which has been rendered hydrophilic by treatment with an aqueous solution of polyvinyl phosphonic acid (oxide weight 3 g/m 2 ) and dried for 2 minutes at 110 °C (circulation oven). The resulting thickness of the layer is 1.4 g/m 2 .
  • Components (D) to (F) are various optical brighteners according to the present invention. All the sensitisers are used in equimolar concentrations. Two levels of concentration are 5 evaluated for each sensitiser.
  • Table 1 Composition of the coating solutions (amounts expressed as parts per weight), layer thickness and presence of crystal like pinholes
  • (G) Heliogene blue D 7490® dispersion (9.9 wt.%, viscosity 7.0 mm 2 /s at 25 °C), trade name of BASF AG.
  • H 2,2'-Bis(2-chlorophenyl)-4,4',5,5'-tetraphenyl- 1 ,2-bisimidazole.
  • II 2-Mercaptobenzothiazole.

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Abstract

A composition that is photopolymerizable upon absorption of light in the wavelength range from 300 to 450 nm, the composition comprising a binder, a polymerizable compound, a sensitizer and a photoinitiator, characterized in that the sensitizer is an optical brightening agent having a solubility in methyl ethyl ketone of at least 15 g/kg measured at 20°C, allows to produce printing plates without pinhole defects, even if the printing plate precursor is stored before exposure and processing.

Description

Photopolymcrizablc composition
FIELD OF THE INVENTION
The present invention relates to a photopolymerizable composition which is sensitized for the wavelength range from 300 to 450 nm and which comprises an optical brightening agent as sensitizer. The invention also relates to a printing plate precursor comprising said composition and a method for making a printing plate therewith.
BACKGROUND OF THE INVENTION
In lithographic printing, a so-called printing master such as a printing plate is mounted on a cylinder of the printing press. The master carries a lithographic image on its surface and a printed copy is obtained by applying ink to said image and then tansferring the ink from the master onto a receiver material, which is typically paper. In conventional, so-called "wet" lithographic printing, ink as well as an aqueous fountain solution (also called dampening liquid) are supplied to the lithographic image which consists of oleophilic (or hydrophobic, i.e. ink-accepting, water-repelling) areas as well as hydrophilic (or oleophobic, i.e. water- accepting, ink-repelling) areas. In so-called "driographic" printing, the lithographic image consists of ink-accepting and ink-abhesive (ink-repelling) areas and during driographic printing, only ink is supplied to the master. Printing masters are generally obtained by the so-called computer-to-film (CtF) method wherein various pre-press steps such as typeface selection, scanning, color separation, screening, tapping, layout and imposition are accomplished digitally and each color selection is transferred to graphic arts film using an image-setter. After processing, the film can be used as a mask for the exposure of an imaging material called plate precursor and after plate processing, a printing plate is obtained which can be used as a master. Since about 1995, the so-called 'computer-to-plate' (CtP) method has gained a lot of interest. This method, also called 'direct-to-plate', bypasses the creation of film because the digital document is transferred directly to a plate precursor by means of a so-called plate-setter. A plate precursor for CtP is often called a digital plate. Digital plates can roughly be divided in three categories : (i) silver plates, which work according to the silver salt diffusion transfer mechanism; (ii) photopolymer plates which contain a photopolymerizable composition that hardens upon exposure to light and (iii) thermal plates of which the imaging mechanism is triggered by heat or by light-to-heat conversion. Thermal plates are mainly sensitized for infrared lasers emitting at 830 nm or 1064 nm. Typical photopolymer plates are sensitized for visible light, mainly for exposure by an Ar laser (488 nm) or a FD-YΛG laser (532 nm). The wide-scale availability of low cost blue or violet laser diodes, originally developed for data storage by means of DVD, has enabled the production of plate-setters operating at shorter wavelength. More specifically, semiconductor lasers emitting from 350 to 450 nm have been realized using an InGaN material. Photopolymer plates sensitized for the wavelength range from 350 to 450 nm have also been described in the prior art. Photopolymer plates generally contain a polymerizable monomer, a binder, a photoinitiator and a sensitizing dye. EP-A 985683 describes a composition comprising a titanocene compound as photoinitiator and specific dyes as sensitizers for the wavelength range from 350 to 450 nm. EP-Λ 1035435 discloses a 1,3- dihydro-l-oxo-2H-indene derivative as sensitizing dye. EP-Λs 1048982 and 1070990 also discloses certain dyes in combination with a titanoccne photoinitiator. Λ wide range of dyes for the wavelength range from 300 to 1200 nm is disclosed in EP-A 1091247. The sensitizing dyes disclosed in the prior art do not produce sufficient speed (sensitivity) to enable a short exposure time with the commercially available blue or violet laser diodes. Typical low-cost blue or violet laser diodes have a light output characterized by low power. The known photopolymer printing plate precursors are unsatisfactory, because they result in printing plates of minor or even unacceptable quality because of so called pinhole defects, that have an irregular crystal-like shape. Defects called pinholes are areas having lateral dimensions of about 50 to 500 μm on the processed printing plate, that don't take up ink and therefore result in exposed areas that don't print. This unfavourable effect is particularly noticeable, if the printing plate precursor is stored before exposure and processing thereof. SUMMARY OF THE INVENTION
It is an object of the present invention, to provide a high-speed composition that is photopolymerizable upon absorption of light in the wavelength range between 300 and 450 nm and that enables to produce imaging materials, such as printing plates or photoresist materials, which don't have pinhole defects. That object is surprinsingly realized by a photopolymerizable composition, wherein a sensitizer having a solubility in methyl ethyl ketone of at least 15 g/kg measured at 20°C is used. When said composition is coated on a suitable support, a printing plate precursor according to the present invention is obtained that is sensitive to the wavelength range from 300 to 450 nm. The printing plate precursor of the present invention is a flexographic or lithographic printing plate precursor, the latter being highly preferred. Also a method of making a printing plate wherein said printing plate precursor is exposed with a laser having an emission in the wavelength range from 300 to 450 nm, is an aspect of the present invention. Preferred photopolymer plate precursors according to the present invention can be exposed with an energy density, measured on the surface of the plate of 100 μJ/cm2 or less. Preferred embodiments of the composition, of the printing plate precursor, of the method of making a printing plate and of the use according to the present invention are defined in the dependent claims.
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to a composition (photopolymerizable composition) that is photopolymerizable upon absorption of light in the wavelength range from 300 to 450 nm, preferably from 350 to 430 nm and particularly preferred from 360 to 420 nm, the composition comprising a binder, a polymerizable compound, a sensitizer and a photoinitiator, characterized in that the sensitizer is an optical brightening agent having a solubility in methyl ethyl ketone of at least 15 g/kg measured at 20°C. When searching for the reason, why the known printing plate precursors result in printing plates with pinhole defects, it was surprisingly found, that the sensitizer has a great influence on the tendency that pinholes appear, the most important factor being the solubility of the sensitizer in methyl ethyl ketone. When using a sensitizer having a solubility in methyl ethyl ketone of at least 15 g/kg measured at 20°C, only an acceptable amount of pinholes appears, and preferred sensitizers 5 have a solubility in methyl ethyl ketone of from 15 to 250 g/kg measured at 20°C. But also the structure has been found to be of importance for the appearance of pinholes and it has been found, that optical brightening agents are preferred sensitizers for printing plate precursor of the present invention and allow, in combination with the solubility disclosed above, to prepare printing plates that are essantially free from pinholes and even ι o completely free of pinholes. Although not knowing about the mechanism, it is thought, that the sensitizing dyes of the present invention have a good compatibility with the other ingredients of the photopolymerisable layer and therefor don't induce the creation of pinholes. A typical optical brightener, also known as "fluorescent whitening agenf , is a is colorless to weakly colored organic compound that is capable of absorbing light having a wavelength in the range between 300 and 450 nm and of emitting the absorbed energy as fluorescent light having a wavelength in the range between 400 and 500 nm. A description of the physical principle and the chemistry of optical brighteners is given in Ullmann's Encyclopedia of Industrial Chemistry, Sixth Edition, Electronic Release, Wiley- VCH 1998. 20 Basically, suitable optical brightener contain π-elechon systems comprising a carbocyclic or a heterocyclic nucleus. Suitable representatives of these compounds are e. g. stilbenes, distyrylbenzenes, distyrylbiphenyls, divinylstilbenes, triazinylaminostilbenes, stilbenyltriazoles, stilbenylnaphthotriazoles, bis-triazolstilbenes, benzoxazoles, bisphenylbenzoxazoles, stilbenylbenzoxazoles, bis-benzoxazoles, furans, benzofurans, bis- 25 benzimidazoles, diphenylpyrazolines, diphenyloxadiazoles, coumarins, naphthalimides, xanthenes, carbostyrils, pyrenes and 1,3,5-triazinyl-derivatives. More specifically, optical brightening agents having a structure according to one of the following formulae are preferred sensitizers for use in the composition of the present invention :
Figure imgf000006_0001
Figure imgf000006_0002
Figure imgf000006_0004
Figure imgf000006_0005
Figure imgf000007_0001
Figure imgf000007_0002
Figure imgf000007_0003
Figure imgf000007_0004
Figure imgf000007_0005
Figure imgf000007_0006
Figure imgf000008_0001
Figure imgf000008_0002
Figure imgf000008_0003
wherein X is one of the following groups, * denoting the position of attachment in the above formulae :
Figure imgf000009_0001
Figure imgf000009_0002
and wherein one or more of the nuclei in each of the above formulae (in) to (XVII) may be independently substituted by one or more groups selected from alkyl, alkoxy, alkylthio, cyano, halogeno, alkylcarbonyl, alkoxycarbonyl, acyloxy, carboxyl, nitrile, amino, hydroxyl, alkylsulfonyl and aminosulfonyl. The optical brighteners can be used as a single compound or as a mixture of several materials. The overall amount of these compounds ranges from 0.1 to 10 % by weight- preferably 0.5 to 8 % by weight with respect to the total weight of the non-volatile compounds in the composition. Highly preferred optical brighteners include compounds of formulae (III) and/or (IV), and in particular compounds of formulae (Ilia) and/or (Wa):
Figure imgf000010_0001
wherein R1 to R in dependently represent a hydrogen atom, an alkyl group, an alkoxy group, a cyano group or a halogen atom, and at least one of R1 to R10 represents an alkoxy group having more than 1 carbon atom;
wherein
R15 to R32 independently represent a hydrogen atom, an alkyl group, an alkoxy group, a is cyano group or a halogen atom, and at least one of R15 to R24 represents an alkoxy group having more than 1 carbon atom. The alkyl and alkoxy groups of the present invention can be optionally substituted and their substituent can be selected to adjust the solubility of the sensitizer and may be, for example, p.o halogen, ester, ether, thioether or hydroxy. The alkyl or alkoxy groups may be shaight chain or cyclic, but a branched chain is preferred for the sensitizers of formulae (Ilia) and (IVa). Particular advantages with respect to the pinhole defects .ire achieved with sensitisers of formula (Ilia), wherein R1, R5, R6, R10, R11, R12, R13 and R14 independently represent a hydrogen atom, a fluorine atom or a chlorine atom, in particular R1, R5, R6, and R10 being a hydrogen atom; R2 to R4, R7 to R9, independently are alkoxy groups; and at least two of the alkoxy groups are branched and have from 3 to 15 carbon atoms. Especially preferred for the present invention are sensitizers of formulae (Ilia) as disclosed above, wherein R2, R4, R7, R9 independently represent a methoxy group and R3 and R8 independently are branched alkoxy groups having 3 to 15 carbon atoms. Particular advantages with respect to the pinhole defects are also achieved with sensitisers of formula (IVa), wherein R15, R19, R20, R24, R25 to R32, independently represent a hydrogen atom, a fluorine atom or a chlorine atom, in particular R15, R19, R20, R24 being a hydrogen atom; R16 to R18, R21 to R23, independently are alkoxy groups; and at least two of the alkoxy groups are branched and have from 3 to 15 carbon atoms. Especially preferred for the present invention are sensitizers of formulae (IVa) as disclosed above, wherein R16, R18, R , R independently represent a methoxy group and R andR independently are branched alkoxy groups having 3 to 15 carbon atoms.
The following structures are examples of preferred sensitizers of the present invention and their solubility S is given in brackets as g sensitizer/kg methyl ethyl ketone measured at 20°C.
Figure imgf000011_0001
Figure imgf000012_0001
Figure imgf000012_0002
Figure imgf000012_0003
Figure imgf000013_0001
Figure imgf000013_0002
Figure imgf000014_0001
Most sensitizers useful for the present invention can be synthesised by known methods and the synthesis of the highly preferred sensitizers of formulae (Ilia) and ( IVa) can be done in analogy to the synthesis of sensitizer (III-l) as disclosed in the following. Synthesis of intermediate (C-3)
Figure imgf000015_0001
To a mixture of 8.365 kg (45.0 mol) syringaldehyde (C-1) and 1.494 kg (9.0 mol) potassium iodide is added 20.25 L sulfolane at room temperature. After heating up this mixture to 30°C under nihogen, 3.12 kg (47.25 mol) of KOH and 2.80 kg (20.25 mol) K2CO3 are added. After warming the reaction mixture to 75°C, 12.78 kg (90.0 mol) 2-bromo butane (C-2) is added over a period of 30 minutes. Heating at 75°C is continued for 24 hours, followed by cooling to 25°C. Then 25 L Water is added and the reaction product is extracted
J O with 18 L methyl t-butyl ether (MTBE). The organic phase is consecutively a) two times washed with 6.0 L of a 7.5 wt.% K2CO3 solution in water respectively, b) two times washed with 13.5 L of pure water respectively and finally, c) two times washed with 4.5 kg of a 20 wt.% NaCl solution in water respectively. The solvent (MTBE) is removed by distillation under reduced pressure of 50 mBar at 75°C and thereby are obtained 7.845 kg (theoretical
15 yield of 75 %) of the crude intermediate (C-3) as a yellow oil, that is used in the synthesis of (III-l) without further purification.
P0 Synthesis of sensitizer (III-l)
Figure imgf000016_0001
Figure imgf000016_0002
To a mixture of 9.63 kg (25.46 mol) p-xylylene-bis-phosphonate (C-4) and 12.13 kg (50.92 mol) of the crude intermediate (C-3) in 20 L THF, 4.70 kg (71.3 mol) of KOH is added at room temperature. After heating the stirred reaction mixture at reflux for 3.5 hours, the reaction product is precipitated by adding a mixture of 25.2 kg methanol and 9.9 kg water, followed by further cooling to 20°C. The crystalline product (III-l) is filtered off, washed with several portions of methanol/water on the filter and dried at 50°C. The yield is 9.05 kg (theoretical yield of 67 %) of (III-l) having a melting point of 154°C. A suitable synthesis for the p-xylylene-bis-phosphonate (C-4) is known from the literature, e.g. from B.P. Lugovkin andB.A. Arbuzov, Doklady Akademii Nauk SSSR (1948), 59, pages 1301 to 1304. The known photopolymerization initiators can be used in the composition of the 5 present invention. Suitable classes include aromatic ketones, aromatic onium salts, organic peroxides, thio compounds, hexaarylbisimidazole compounds, ketooxime ester pounds, borate compounds, azinium compounds, metallocene compounds, active ester compounds and compounds having a carbon-halogen bond. Many specific examples of such photoinitiators can be found in EP-A 1091247. The best results, in particular the highest sensitivity, can be ιo obtained by the combination of an optical brightener as sensitizer and a hexaarylbisimidazole (HABI, dimer of triaryl-imidazole) as photoinitiator. A procedure for the preparation of HABIs is described in DE 1470 154 and their use in photopolymer-izable compositions is documented in EP 24 629, EP 107 792, US 4 410 621, EP 215 453 and DE 3 211 312. Preferred derivatives are e. g. 2,4,5,2',4',5'-hexaphenylbisimidazole, 2,2'-bis(2-chlorophenyl)- i5 4,5,4',5'-tetraphenylbisimidazole, 2,2'-bis(2-bromophenyl)-4,5,4',5'-tetraphenylbisimidazole, 2,2'-bis(2,4-dichlorophenyl)-4,5,4',5'-tetaphenylbisimidazole, 2,2'-bis(2-chlorophenyl)- 4,5,4',5'-tetrakis(3-methoxyphenyl)bisimidazole, 2,2'-bis(2-chlorophenyl)-4,5,4',5'- tetrakis(3,4,5-himethoxyphenyl)-bisimidazole, 2,5,2',5'-tetrakis(2-chlorophenyl)-4,4'-bis(3,4- dimethoxyphenyl)bisimidazole, 2,2'-bis(2,6-dichlorophenyl)-4,5,4',5'-
20 tetraphenylbisimidazole, 2,2,-bis(2-nitrophenyl)-4,5,4l,5'-tetraphenyIbisimidazole, 2,2'-di-o- tolyl-4,5,4',5'-tehaphenylbisimidazole, 2,2'-bis(2-ethoxyphenyl)-4,5,4',5'- tetraphenylbisimidazole and 2,2l-bis(2,6-difluorophenyl)-4,5,4,,5'-tetaphenylbisimidazole. The amount of the HABI photoinitiator typically ranges from 0.01 to 30 % by weight, preferably from 0.5 to 20 % by weight, relative to the total weight of the non volatile
25 components of the photopolymerizable composition. The binder can be selected from a wide series of organic polymers. Compositions of different binders can also be used. Useful binders include for example chlorinated polyalkylenes in particular chlorinated polyethylene and chlorinated polypropylene; poly(methacrylic acid) alkyl esters or alkenyl esters in particular poly(methyl (meth)acrylate),
3o ρoly(ethyl (meth)acrylate), poly(butyl (meth)acrylate), poly(isobutyl (mefh)acrylate), poly(hexyl (meth)acrylate), poly((2-ethylhexyl) (meth)acrylate) and poly(alkyl (meth)acrylate); copolymers of (meth)acrylic acid alkyl esters or alkenyl esters with other copolymerizable monomers, in particular with (meth)acrylonitrile, vinyl chloride, vinylidene chloride, styrene and/or butadiene; poly(vinyl chloride) (PVC); vinylchloride/(meth)acrylonitrile copolymers; poly(vinylidene chloride) (PVDC); vinylidene chloride/(meth)acrylonitrile copolymers; poly(vinyl acetate); poly(vinyl alcohol); poly (meth)acrylonitrile; (meth)acrylonitrile/styrene copolymers; (meth)acrylamide/alkyl (meth)acrylate copolymers; (meth)acrylonitrile/butadiene/styrene (ABS) terpolymers; polystyrene; poly(α-methylstyrene); polyamides; polyurethanes; polyesters; cellulose or cellulose compounds like methyl cellulose, ethyl cellulose, acetyl cellulose, hydroxy-(Cι_4- alkyl)cellulose, carboxymethyl cellulose; poly(vinyl formal) and poly(vinyl butyral).
Particularly suitable are binders that are insoluble in water, but on the other hand are soluble or at least swellable in aqueous-alkaline solutions. Further effective binders are polymers that are soluble in common organic coating solvents. Particular suitable for the purpose of the present invention are binders containing carboxyl groups, in particular polymers or copolymers containing monomeric units of α,β- unsaturated carboxylic acids and/or monomeric units of α,β-unsaturated dicarboxylic acids, preferably acrylic acid, methacrylic acid, crotonic acid, vinylacetic acid, maleic acid or itaconic acid. By the term "copolymers" are to be understood in the context of the present invention polymers containing units of at least 2 different monomers, thus also terpolymers and higher mixed polymers. Particular useful examples of copolymers are those containing units of (meth)acrylic acid and units of alkyl (meth)acrylates, allyl (meth)acrylates and/or (meth)acrylonitrile as well as copolymers containing units of crotonic acid and units of alkyl (meth)acrylates and/or (meth)acrylonitrile and vinylacetic acid/alkyl (meth)acrylate copolymers. Also suitable are copolymers containing units of maleic anhydride or maleic acid monoalkyl esters. Among those are, for example, copolymers containing units of maleic anhydride and styrene, unsaturated ethers or esters or unsaturated aliphatic hydrocarbons and the esterification products obtained from such copolymers. Further suitable binders are products obtainable from the conversion of hydroxyl-containing polymers with intramolecular dicarboxylic anhydrides. Further useful binders are polymers in which groups with acid hydrogen atoms are present, some or all of which are converted with activated isocyanates. Examples of these polymers are products obtained by conversion of hydroxyl-containing polymers with aliphatic or aromatic sulfonyl isocyanates or phosphinic acid isocyanates. Also suitable are polymers with aliphatic or aromatic hydroxyl groups, for example copolymers containing units of hydroxyalkyl (meth)acrylates, ally] alcohol, hydroxystyrene or vinyl 5 alcohol, as well as epoxy resins, provided they carry a sufficient number of free OH groups. The organic polymers used as binders have a typical mean molecular weight Mw between 600 and 200 000, preferably between 1 000 and 100 000. Preference is further given to polymers having an acid number between 10 to 250, preferably 20 to 200, or a hydroxyl number between 50 and 750, preferably between 100 and 500. The amount of binder(s) O generally ranges from 10 to 90 % by weight, preferably 20 to 80 % by weight, relative to the total weight of the non-volatile components of the composition. The polymerizable compound can be selected from a wide series of photo-oxidizable compounds. Suitable compounds contain primary, secondary and in particular tertiary amino groups. Radically polymerizable compounds containing at least one urethane and/or urea
J5 group and/or a tertiary amino group are particularly preferred. By the term "urea group" has to be understood in the context of the present invention a group of the formula >N-CO-N<, wherein the valences on the nihogen atoms are saturated by hydrogen atoms and hydrocarbon radicals (with the proviso that not more than one valence on either of the two nitrogen atoms is saturated by one hydrogen atom). However, it is also possible for one valence on one
20 nitrogen atom to be bonded to a carbamoyl (-CO-NH-) group, producing a biuret structure. Also suitable are compounds containing a photo-oxidizable amino, urea or thio group, which may be also be a constituent of a heterocyclic ring. Compounds containing photo- oxidizable enol groups can also be used. Specific examples of photo-oxidizable groups are triethanolamino, triphenylamino, thiourea, imidazole, oxazole, thiazole, acetylacetonyl, N-
25 phenylglycine and ascorbic acid groups. Particularly suitable compounds are monomers containing photo-oxidizable groups corresponding to the following formula (XVIII):
R{m.n)Q[(-CH2-CR1R2-O)a-CO-NH-(X1-NH-CO-O)b-X2-(O-CO-CR3=CH2)c]n (XVIII)
30 wherein R represents an alkyl group having 2 to 8 carbon atoms ((C2- ) alkyl group), a (C2-C8) hydroxyalkyl group or a (C6-C1 ) aryl group,
Q represents -S-, — N I , — N I E — N I or
Figure imgf000020_0001
wherein 5 E represents a divalent saturated hydrocarbon group of 2 to 12 carbon atoms, a divalent 5- to 7-membered, saturated iso- or heterocyclic group, which may contain up to 2 nitrogen, oxygen and/or sulfur atoms in the ring, a divalent aromatic mono- or bicyclic isocyclic group of 6 to 12 carbon atoms or a divalent 5- or 6-membered aromatic heterocyclic group; andO D1 and D2 independently represent a saturated hydrocarbon group of 1 to 5 carbon atoms, R1 and R2 independently represent a hydrogen atom, an alkyl or alkoxyalkyl group, R3 represents a hydrogen atom, a methyl or ethyl group, X1 represents a shaight-chained or branched saturated hydrocarbon group of 1 to 12 carbons atoms, X2 represents a (c-H)-valent hydrocarbon group in which up to 5 methylene groups may have been replaced by oxygen atoms, a is an integer from 0 to 4, b is 0 or 1 ,O c is an integer from 1 to 3, m is an integer from 2 to 4 and n is an integer from 1 to m. Compounds of this nature and processes for their preparation are described in EP 287 818. If a compound of general formula (XVIII) contains several radicals R or several radicals5 according to the structure indicated between square brackets, i. e. if (n-m) > 1 and n>l , these radicals can be identical or different from one another. Compounds according to formula (XVIII) wherein n = m are particularly preferred. In this case, all radicals contain polymerizable groups. Preferably, the index a is 1 ; if several radicals are present, a cannot be 0 in more than one radical. If R is an alkyl or hydroxyalkyl group, R generally contains 2 to 6, particularly 2 to 4 carbon atoms. Aryl radicals R are in general mononuclear or binuclear, preferably however mononuclear, and may be substituted with ( -C5) alkyl or (C1-C5) alkoxy groups. If R1 and R2 are alkyl or alkoxy groups, they preferably contain 1 to 5 carbon atoms. R3 is preferably a hydrogen atom or a methyl group. X1 is preferably a straight-chained or 5 branched aliphatic and/or cycloaliphatic radical of preferably 4 to 10 carbon atoms. In a preferred embodiment, X2 contains 2 to 15 carbon atoms and is in particular a saturated, straight-chained or branched aliphatic and or cycloaliphatic radical containing this amount of carbon atoms. Up to 5 methylene groups in these radicals may have been replaced by oxygen atoms; in the case of X2 being composed of pure carbon chains, the radical generally has 2 to O 12 carbon atoms, preferably 2 to 6 carbon atoms. X2 can also be a cycloaliphatic group of 5 to 10 carbon atoms, in particular a cyclohexane diyl group. The saturated heterocyclic ring formed by D1, D2 and both nitrogen atoms generally has 5 to 10 ring members in particular 6 ring members. In the latter case the heterocyclic ring is preferably a piperazine and the radical derived therefrom a piperazine- 1 ,4-diyl radical. In a preferred embodiment, radical E is an alkane diyl group which normally contains about 2 to 6 carbon atoms. Preferably the divalent 5- to 7-membered, saturated, isocyclic group E is a cyclohexane diyl group, in particular a cyclohexane- 1 ,4-diyl group. The divalent, isocyclic, aromatic group E is preferably an ortho-, meta- or para-phenylene group. The divalent 5- or 6-membered aromatic heterocyclic group E, finally, contains preferably nihogen and/or sulphur atoms in the heterocyclic ring, c is
20 preferably 1, i. e. each radical in the square bracket generally contains only one polymerizable group, in particular only one (meth)acryloyloxy-group. The compounds of formula (XVIII) wherein b = 1 , which accordingly contain two urethane groups in each of the radicals indicated in the square brackets, can be produced in a known way by conversion of acrylic esters or alkacrylic esters which contain free hydroxyl
P5 groups with equimolar amounts of diisocyanates. Excess isocyanate groups are then, for example, reacted with tris(hydroxyalkyl)amines, N,N'-bis(hydroxyalkyl) piperazines or N,N,N',N'-tetrakis(hydroxyalkyl)alkylenediamines, in each of which individual hydroxyalkyl groups may have been replaced by alkyl or aryl groups R. If a = 0, the result is a urea grouping. Examples of the hydroxyalkylamine starting materials are diethanolamine,
30 triethanolamine, tris(2-hydroxypropyl)amine, tris(2-hydroxybutyl)amine and alkyl-bis- hydroxyalkylamines. Examples of suitable diisocyanates are hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 1 ,4-cyclohexylene diisocyanate (= 1,4- diisocyanatocyclohexane) and l,l,3-trimethyl-3-isocyanatomethyl-5-isocyanatocyclohexane. The hydroxy-containing esters used are preferably hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate and hydroxyisopropyl (meth)acrylate. The polymerizable compounds of formula (XVIII) wherein b = 0 are prepared convertir the above-described hydroxyalkylamino compounds with isocyanate-containing acrylic or alkacrylic esters. A preferred isocyanate-containing ester is isocyanoto-ethyl (meth)acrylate. Further polymerizable compounds comprising photooxidisable groups suitable for the purpose of the invention are compounds according to the following formula (XIX):
R(m.n)Q[(-CH2-CR1R -O)a -(CH2-CH[CH2-O-CO-CR3=CH2]-O)b-H]n (XIX)
wherein a' and b' independently represent integers from 1 to 4 and Q, R1, R , R , n and m have the same meaning as above and Q can also be a group of the formula >N-E'-N< wherein the radical E' corresponds to the following formula (XX):
-CH2-CH(OH)-CH2-[O-(p)C6H4-C(CH3) -(p)C6H4-CH2-CH(OH)-CH2-]c (XX)
wherein c has the same meaning as in formula (I) and (p)C6H represents para-phenylene. The compounds of formula (XIX) are prepared analogously to those of formula
(XVIII), except that the conversion products of hydroxyalkyl acrylates or alkacrylates and diisocyanates are replaced by the corresponding acrylic and alkacrylic glycide esters.
Compounds of formula (XX) and processes to their preparation are disclosed in EP 316 706. Further useful polymerizable compounds containing photooxidisable groups are acrylic and alkacrylic esters of the following formula (XXI) :
Figure imgf000023_0001
wherein
Q' represents — > Ij , D3
Figure imgf000023_0002
wherein D1 and D2 indepently represent a saturated hydrocarbon group of 1 to 5 carbon atoms and D3 represents a saturated hydrocarbon group of 4 to 8 carbon atoms, which together with the nihogen atom forms a 5- or 6-membered heterocyclic ring; X1 represents -CjH2i- or
"CiH21-1 O-CO-NH(-X1-NH-CO-O)b-X2-O-CO-CR3=CH2;
Z represents a hydrogen atom or a radical of the following formula: -CkH2k-O-CO-NH(-X1 -NH-CO-O)b-X2-O-CO-CR3=CH2 ; i,k independently represent integers from 1 to 12; n' represents an integer from 1 to 3; and a is 0 or 1 ; provided that a is 0 in at least one of the radicals bonded to Q; X1, R3, a and b have the same meaning as given in the above formula (Vϋl); and
X2 represents a divalent hydrocarbon group in which up to 5 methylene groups may be replaced by oxygen atoms. In formula (XXI) index a is preferably 0 or 1 and i preferably represents a number between 2 and 10. Preferred radicals Q are piperazine- 1 ,4-diyl (D1 =D2 = CH2-CR2), piperidine-1-yl (D3 = (CH2)5, Z = H) and 2-(2-hydroxyethyl)-piperidine-l-yl (D3 = (CH )5, Z
= CH2CH2OH). Of the compounds of formula (XXI), those which apart from a urea group contain at least one urethane group are preferred. Here again, by the term "urea group" has to be understood the group of formula >N-CO-N< already mentioned above. Compounds of formula (XXI) and processes for their preparation are disclosed in EP 355 387. Also suitable polymerizable compounds are reaction products of mono- or diisocyanates with multifunctional alcohols, in which the hydroxy groups are partly or completely esterified with (meth)acrylic acid. Preferred compounds are materials, which are synthesized by the reaction of hydroxyalkyl-(meth)acrylates with diisocyanates. Such compounds are basically known and for instance described in DE 28 22 190 and DE 20 64079. The amount of polymerizable compound comprising photooxidisable groups generally ranges from 5 to 75 % by weight, preferably from 10 to 65 % by weight, relative to the total weight of the non volatile compounds of the photopolymerizable composition. Moreover, the composition can contain polyfunctional (meth)acrylate or alkyl(meth)acrylate compounds as crosslinking agents. Such compounds contain more than 2, preferably between 3 and 6 (meth)acrylate and/or alkyl(meth)acrylate groups and include in particular (meth)acrylates of saturated aliphatic or alicyclic trivalent or polyvalent alcohols such as trimethylol ethane, himethylol propane, pentaerythritol or dipentaeiythritol. The total amount of polymerizable compounds generally ranges from about 10 to 90 % by weight, preferably from about 20 to 80 % by weight, relative to the total weight of the non volatile components of the photopolymerizable composition of the present invention. The following specific example is also a suitable polymerizable compound :
Figure imgf000025_0001
In order to achieve a high sensitivity, it is advantageous to add a radical chain transfer agent as described in EP 107 792 to the photopolymerizable composition of the present invention. The preferred chain tønsfer agents are sulfur containing compounds, especially thiols like e. g. 2-mercaptobenzothiazole, 2-mercaptobenzoxazole or 2-mercapto- benzimidazole. The amount of chain transfer agent generally ranges from 0.01 to 10 % by weight, preferably from 0.1 to 2 % by weight, relative to the total weight of the non volatile components of the photopolymerizable composition.
J O Optionally pigments, e.g. predispersed phthalocyanine pigments, can be added to the composition of the present invention for dyeing the composition and the layers produced therewith. Their amount generally ranges from about 1 to 15 % by weight, preferably from about 2 to 7 % by weight related to the total weight of the non volatile components of the composition. Particularly suitable predispersed phthalocyanine pigments are disclosed in DE
75 199 15 717 and DE 199 33 139. Preference is given to metal-free phthalocyanine pigments. In order to adjust the photopolymerizable composition according to the present invention to specific needs, thermal inhibitors or stabilizers for preventing thermal polymerization may be added. Furthermore additional hydrogen donors, dyes, colored or colorless pigments, color formers, indicators and plasticisers may be present. These additives are convieniently selected so that they absorb as little as possible in the actinic range of the imagewise applied radiation. The present invention also relates to a photopolymer printing plate precursor comprising a layer (photopolymerizable layer) containing the photopolymerizable composition of the present invention on a support. The photopolymerizable composition according to the present invention is applied to the support by processes which are known per se to the person skilled in the art. In general, the components of the photopolymerizable composition are dissolved or dispersed in an organic solvent or solvent mixture, the solution or dispersion is applied to the intended support by pouring on, spraying on, emersion, roll application or in a similar and the solvents are removed during the subsequent drying. The known supports can be used for the photopolymer printing plate of the present invention, like e. g. foils, tapes or plates made of metal or plastics and in the case of screen- printing also of Perlon gauze. Preferred metals are aluminium, aluminium alloys, steel and zinc, aluminium and aluminium alloys being particularly preferred. Preferred plastics are polyester and cellulose acetates, polyethylcneterephthalate (PET) being particularly preferred. In most cases it is preferred, to heat the surface of the support mechanically and/or chemically and/or elechochcmically to optimally adjust the adherence between the support and the photosensitive coating and/or to reduce the reflection of the imagewise exposed radiation on the surface of the support (antihalation). The most preferred support to be used for the present invention is made of aluminium or an aluminium alloy, its surface is electrochemically roughened, thereafter anodize and optionally heated with a hydrophilizing agent like e. g. poly(vinylphosphonic acid). The printing plate precursors of the present invention preferably have a protective layer (overcoat layer) provided on top of the photopolymerizable layer. Said protective layer may contain the ingredients known in the art, in particular water soluble polymers like poly(vinyl alcohols) or poly(vinyl pyrrolidone), surface wetting agents, coloring agents, complexants and biocides. Among said complexants, ethoxylated ethylene diamine compounds have been found to be particularly preferred for the present invention. Preferably the protective overcoat according to the present invention comprises at least one type of poly(vinyl alcohol), wherein the mean degree of saponification is less than 93 mol-%. The degree of saponification is related to the production of poly(vinyl alcohols). As 5 the monomer of poly(vinyl alcohol), vinyl alcohol, is nonexistent, only indirect methods are available for the production of poly(vinyl alcohol). The most important manufacturing process for poly(vinyl alcohol) is the polymerization of vinyl esters or ethers, with subsequent saponification or transesterification. The preferred starting material for the poly (vinyl alcohol) of the present invention is a vinyl alcohol esterified by a mono carboxylic acid and in
70 particular vinyl acetate, but derivatives of vinyl acetate, vinyl esters of di carboxylic acids, vinyl ethers and the like can also be used. The degree of saponification as defined for the present invention is the molar degree of hydrolysis irrespective of the process used for the hydrolysis. Pure poly (vinyl alcohol) has e. g. a degree of saponification of 100 mol-%, but commercial products often have a degree of saponification of 98 mol-%. The poly(vinyl
J5 alcohols) as preferably used for the present invention contain mainly 1,3-diol units, but may also contain small amounts of 1,2-diol units. In the partially saponified poly(vinyl alcohols) the ester or the ether group can be distributed statistically or blockwise. Preferred partially saponified poly(vinyl alcohols) of the present invention have a viscosity of a 4 % aqueous solution at 20°C of 4 to 60 mPa»s, preferably of 4 to 20 mPa»s and in particular of 4 to 10
2o mPa's. Poly(vinyl alcohols) preferred for the present invention are commercially available e. g. under the tradename Mowiol. Those products are characterised by two appended numbers, meaning the viscosity and the degree of saponification. For example, Mowiol 8 - 88 or Mowiol 8/88 mean a poly(vinyl alcohol) having as 4 % aqueous solution at 20°C a viscosity
25 of ca 8 mPa»s and a degree of saponification of 88 mol-%. It is further preferred to use a mixture of two or more compounds. Preferably poly(vinyl alcohols) differing in viscosity as defined above and/or in saponification degree are combined. Particularly preferred are mixture of poly(vinyl alcohols) that differ in viscosity of their 4 % aqueous solutions at 20°C for at least 2 mPa»s or that differ in saponification degree for at least 5 mol-%. Most preferred
30 are mixtures comprising at least 3 types of poly(vinyl alcohols), wherein at least two compounds differ in viscosity as defined above for at least 2 mPa«s and at least two compounds differ in saponification degree for at least 5 mol-%. Preferably the overall mean saponification degree of all poly(vinyl alcohols) used in the protective layer has to be less than 93 mol-%. In a further preferred embodimend of the 5 present invention said overall mean saponification degree ranges from 71 mol-% to less than 93 mol-% and in particular from 80 mol-% to 92,9 mol-%. The overall mean saponification degree of the poly(vinyl alcohols) used in the protective overcoat of a printing plate precursor can be determined experimentally via 13C- NMR. To measure the I3C-NMR spectra, approximately 200 mg of the protective overcoat are O dissolved in 1.0 ml DMSO and from this solution a 75 MHz 13C-NMR spectrum is taken, whose resonances can easily be interpreted and allow to calculate the degree of saponification (experimental values). A good correlation is obtained between said experimental values and the values known from the product specification of the poly(vinyl alcohols). The latter values are hereinafter called theoretical values of the mean saponification degree and can easily be
J5 calculated, when mixture of poly(vinyl alcohols) are used. Preferably the poly(vinyl alcohol) of the present invention is used in 50 to 99.9 weight percent (wt.%) relative to the total weight of the non- volatile compounds of the protective overcoat. Additionally other water soluble polymers can be added to the layer such as poly(vinyl pyrrolidonc), poly(ethylene oxide), gelatin, gum arabic, oxygen binding polymers
2o with aliphatic amine groups known from EP 352 630 Bl , methyl vinylcthcr/maleic anhydride copolymers, poly(carboxylic acids), copolymers of ethylene oxide and poly(vinyl alcohol), carbon hydrates, hydroxy ethyl cellulose, acidic cellulose, cellulose, poly(arylic acid) and mixtures of these polymers. Preferably the ρoly(vinyl pyrrolidone) is only used in small quantities compared to the
P5 poly(vinyl alcohol). In a preferred embodiment of the present invention poly(vinyl pyrrolidone) is used from 0 to 10 parts by weight of the poly(vinyl alcohol) used, from 0 to 3 parts by weight being particularly preferred. Most preferred no poly(vinyl pyrrolidone)compounds are used. In addition to the poly(vinyl alcohol) of the present invention and the optional
30 watersoluble polymers disclosed above, the known ingredients of protective layers can be used. The protective layer has to be transparent for actinic light and preferably has a dry thickness of 0.2 to 10 g/m2, 1.0 to 5 g m2 beeing particularly preferred. Preferably it is homogeneous, substantially impermeable to oxygen, waterpermeable, and can be washed off preferably with the conventional developer solutions used to form a printing relief after imagewise exposure of the photosensitive layer. Said photopolymerizable layer is removed imagewise, whereas the protective layer is removable over the entire area of the element created. The wash-off of the protective layer can be done in a separate step, but can be done during the development step as well. The protective layer can be coated on the photosensitive layer with known techniques and the coating solution preferably contains water or a mixture of water and an organic solvent. To allow a better wetting, the coating solution preferably contains, related to the solid content, up to 10 wt.%, and particular preferred up to 5 wt.% of a surface active agent. Suitable representatives of surface active agents comprise anionic, cationic and nonionic surface active agents like sodium alkylsulfates and -sulfonates having 12 to 18 carbon atoms, an example of which is sodium dodecylsulfate, N-cetyl- and C-cetyl betaine, alkylaminocarboxylate and -dicarboxylate, and polyethylene glycols with a mean molar weight up to 400. In addition, further functions can be added to the protective layer. For example, it can be possible to improve the safelight suitability without decreasing the sensitivity of the layer by adding a coloring agent, e. g. a water-soluble dye, that has excellent hansmission to the light having a wavelength of 300 to 450 nm and that absorbs the light having a wavelength of 500 nm or more. This principle can easily be varied for different wavelengths to adjust the effective spectral sensitivity distribution of the printing plate precursor as needed. The present invention also relates to a method of making a lithographic printing plate comprising the steps of providing a photopolymer printing plate precursor of the present invention, exposing said printing plate precursor with a laser having an emission wavelength in the range from 300 to 450 nm and processing the printing plate precursor in an aqueous alkaline developer. In preferred embodiment of the process of the present invention the exposure is done with a laser having an emission wavelenth in the range from 380 to 430 nm, in particular in the range from 390 to 420 nm, and the exposure is carried out at an energy density, measured on the surface of the plate, of 100 μJ/cm2 or less. The processing of the printing plate precursor of the present invention is done in the usual manner. After image-wise exposure a pre-heat step is performed to improve the crosslinking of the photosensitive layer. Usually the pre-heat step is then followed by the development step, wherein the complete overcoat layer and the unexposed part of the photosensitive layer are removed. The removal (wash-off) of the overcoat layer and the development of the photosensitive layer can be done in two seperate steps in this order, but can also be done in one step simultaneously. Preferably the overcoat layer is washed-off with water before the development step. What remains on the support after the development step are the exposed and thereby photopolymerized parts of the photosensitive layer. The developer solution used for the development of the exposed printing plate precursors of the present invention preferably is an aqueous alkaline solution having a pH of at least 11, a pH from 11.5 to 13.5 being particularly preferred. The developer solution can contain a small percentage, preferably less than 5 wt.%, of an organic, water-miscible solvent. To adjust the pH of the solution, an alkali hydroxide is preferably used. Examples of preferred, additional ingredients of the developer solution comprise alone or in combination alkali phosphates, alkali carbonates, alkali bicarbonates, an organic amine compound, alkali silicates, buffering agents, complexants, defoamers, surface active agents and dyes, but the suitable ingredients are not limited to the preferred examples and further ingredients can be used. The method of development employed is not particularly limited, and may be conducted by soaking and shaking the plate in a developer, physically removing non-image portions while being dissolved in a developer by means of e. g. a brush, or spraying a developer onto the plate so as to remove non-image portions. The time for development is selected depending upon the above method used so that the non-image portions can adequately by removed, and is optionally selected within a range of 5 seconds to 10 minutes. After the development, the plate my be subjected to a hydrophilic treatment by means of, e. g., gum arabic optionally applied to the printing plate as the case requires (gumming step). EXAMPLES
Examples 1 to 6 and comparative examples 1 and 2 Solubility test in methyl ethyl ketone 1.5 g of the sensitiser is dissolved in 100 g of methyl ethyl ketone and allowed to stir at room temperature (20°C) for a maximum of 24 hours. If the sensitiser is completely dissolved in the methyl ethyl ketone, the sensitiser passes the solubility test and is considered as a preferred sensitiser according to the present invention.
In the table below the results of the solubility tests are given for the different sensitisers
Figure imgf000031_0001
These results demonstrate the low solubility of component C that is used in the comparative examples 1 and 2.
Test of sensitiser compatibility in the layer composition A. Preparation (coating) of the photosensitive layer
A composition was prepared (pw = parts per weight; wt.% = weight percentage) by mixing the components (A) to (M) as specified in table 1. This composition was coated on an electrochemically roughened and anodically oxidized aluminum sheet, the surface of which has been rendered hydrophilic by treatment with an aqueous solution of polyvinyl phosphonic acid (oxide weight 3 g/m2) and dried for 2 minutes at 110 °C (circulation oven). The resulting thickness of the layer is 1.4 g/m2. Components (D) to (F) are various optical brighteners according to the present invention. All the sensitisers are used in equimolar concentrations. Two levels of concentration are 5 evaluated for each sensitiser.
Table 1: Composition of the coating solutions (amounts expressed as parts per weight), layer thickness and presence of crystal like pinholes
Figure imgf000032_0001
J 0 (A) : A solution containing 32.4 wt.% of a methacrylate/ methacrylic acid copolymer (ratio methylmethacrylate: methacrylic acid of 4:1 by weight; acid number: 1 10 g KOH/g) in 2-butanone (viscosity 105 mm2/s at 25°C). (B) : A solution containing 88.2 wt.% of a reaction product from 1 mole of 2,2,4- trimethyl-hexamethylenediisocyanate and 2 moles of hydroxyethylmethacrylate (viscosity 3.30 mmVs at 25°C). (C) : l,4-distyryl-3,4,5-trimethoxybenzene.
(D) : l,4-distyryl-(3,5-trimethoxy, 4-(2-butyl)oxy)benzene. (E) : l,4-distyryl-(3,5-trimethoxy, 4-(2-pentyl)oxy)benzene.
(F) : l,4-distyryl-(3,5-trimethoxy, 4-(l-(2-ethyl)hexyl)oxy)benzene.
(G) : Heliogene blue D 7490® dispersion (9.9 wt.%, viscosity 7.0 mm2/s at 25 °C), trade name of BASF AG. (H) : 2,2'-Bis(2-chlorophenyl)-4,4',5,5'-tetraphenyl- 1 ,2-bisimidazole. (I) : 2-Mercaptobenzothiazole.
(J) : Edaplan LA 411 ® (1 % in Dowanol PM®, trade mark of Dow Chemical Company). (K) : 2-Butanone.
(L) : Propyleneglycol-monomethylether (Dowanol PM®, hade mark of Dow Chemical Company).
B. Preparation (coating) of the top coat layer
On top of the photo layer a solution in water containing 4.9 wt.% of the following composition was coated and dried for 2 minutes at 110 °C :
1.0 pw of partially hydrolyzed polyvinylalcohol (degree of hydrolysis 87.7 %, viscosity 8 mPa«s in a solution of 4 wt.% at 20 °C), 1.0 pw of fully hydrolyzed polyvinylalcohol (degree of hydrolysis 98.4 %, viscosity 4 mPa«s in a solution of 4 wt.% at 20 °C) and 0.5 pw of polyvinylpyrrolidone (k-value 30). The top coat had a dry thickness of 2.0 g/m2. C. Evaluation of the appearance of pinholes 5 Next the plates were stored for 2 days in an environment at 57°C and 34% relative humidity. After this storage test the plates were imaged with an experimental violet platesetter device (flat bed system) equipped with a violet laser diode emitting between 392 - 417 nm. The following imaging conditions were used : JO Scanning speed : 1000 m/sec Image plane power : 10.5 mW Spot diameter : 20 μm Addressability : 1270 dpi As test file a solid of 10 cm x 10 cm was imaged.
J5 After imaging the plate was processed in a Agfa VSP85 processor at a speed of 1.2 m/min. First the plate was heated (pre-heat) to a temperature at the back of the plate of 104°C. Next the overcoat was washed off and finally the photolayer was processed in a water based alkaline developer (Agfa EN 231C) at 28 °C. After a water rinsing and gumming step a solid 2o image of 10 cm x 10 cm was obtained. This image was inspected on 'crystal-like' pinhole defects and the results are summarised in table 1. With the results it is clearly shown, that the sensitizers of the present invention allow to prepare printing plate precursors, that even after storage result in printing plates without pinhole defects.
25

Claims

1. A composition that is photopolymerizable upon absoφtion of light in the wavelength range from 300 to 450 nm, the composition comprising a binder, a polymerizable compound, a sensitizer and a photoinitiator, characterized in that the sensitizer is an optical brightening agent having a solubility in methyl ethyl ketone of at least 15 g kg measured at 20°C.
2. A composition according to claim 1, wherein the sensitizer has a structure according to JO one of the following formulae (III) to (XVII):
Figure imgf000035_0001
Figure imgf000036_0001
Figure imgf000037_0001
wherein X is one of the following groups, * denoting the position of attachment in the above formulae:
Figure imgf000037_0002
Figure imgf000037_0003
and wherein one or more of the nuclei in each of the above formulae (III) to (XVII) may be independently substituted by one or more groups selected from alkyl, alkoxy, alkylthio, cyano, halogeno, alkylcarbonyl, alkoxycarbonyl, acyloxy, carboxyl, nihile, amino, hydroxyl, alkylsulfonyl and aminosulfonyl.
3. A composition according to claim 2, wherein the sensitizer has a structure according to one of the following formulae (Ilia) and/or (TV a):
Figure imgf000038_0001
wherein
R1 to R14 in dependently represent a hydrogen atom, an alkyl group, an alkoxy group, a
? o cyano group or a halogen atom, and at least one of R1 to R10 represents an alkoxy group having more than 1 carbon atom;
Figure imgf000038_0002
5 wherein
R15 to R32 independently represent a hydrogen atom, an alkyl group, an alkoxy group, a cyano group or a halogen atom, 0 and at least one of R15 to R24 represents an alkoxy group having more than 1 carbon atom.
4. A composition according to claim 3, wherein the sensitizer has a structure according to formula (Ilia), wherein R1, R5, R6, R10, R , R12, R13 and R14 independently represent a hydrogen atom, a fluorine atom or a chlorine atom, 5 R2 to R4 and R7 to R9 independently represent alkoxy groups, and at least two of the alkoxy groups are branched and have from 3 to 15 carbon atoms.
5. A composition according to claim 4, wherein R1, R5, R6, R10 represent a hydrogen atom,
JO R2, R4, R7, R9 independently represent a methoxy group, and R3 and R8 independently are branched alkoxy groups having 3 to 15 carbon atoms.
6. A composition according to claim 3, wherein the sensitizer has a structure according to formula (IVa), wherein
J5 R15, R19, R20, R24, R25 to R32, independently represent a hydrogen atom, a fluorine atom or a chlorine atom, R16 to R18 and R21 to R23, independently are alkoxy groups, and at least two of the alkoxy groups are branched and have from 3 to 15 carbon atoms.
2o 7. A composition according to claim 6, wherein R15, R19, R20, R24 represent a hydrogen atom, R , R , R , R independantly represent a methoxy group, and R17 and R22 independently are branched alkoxy groups having 3 to 15 carbon atoms.
25 8. A composition according to any of the preceding claims wherein the photoinitiator is a hexaarylbisimidazole.
9. A composition according to any of the preceding claims wherein the binder is a polymer or copolymer containing monomeric units of an α,β-unsaturated carboxylic acid and/or an 30 α,β-unsaturated dicarboxylic acid.
10. A composition according to any of the preceding claims further comprising a polyfunctional (meth)acrylate or alkyl(meth)acrylate as a crosslinking agent.
11. A composition according to any of the preceding claims wherein the polymerizable 5 compound contains an urethane and/or urea group and/or a tertiary amino group.
12. A composition according to any of the preceding claims further comprising a radical chain transfer agent.
JO 13. A composition according to claim 12 wherein the radical chain transfer agent is a sulfur containing compound.
14. A composition according any of the preceding claims wherein the wavelength range is between 350 and 430 nm.
J5 15. A photopolymer printing plate precursor comprising a photosensitive coating, the coating comprising a composition according to any of the preceding claims.
16. A method of making a lithographic printing plate comprising the steps of providing a
20 photopolymer printing plate precursor according to claim 15, exposing said printing plate precursor with a laser having an emission wavelength in the range from 300 to 450 nm and processing the lithographic printing plate precursor in an aqueous alkaline developer.
17. A method according to claim 16, wherein the laser has an emission wavelength in the 25 range from 380 to 430 nm.
18. Method as defined in claims 14, 15 or 16 wherein the exposure of the lithographic printing plate precursor is carried out at an energy density, measured on the plate surface, of less than 100 μJ/cm2.
30
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CN2004800340559A CN1882879B (en) 2003-09-22 2004-09-01 Photopolymerizable composition
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Publication number Priority date Publication date Assignee Title
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US20070224543A1 (en) * 2004-05-06 2007-09-27 Agfa-Gevaert Photopolymer Printing Plate Precursor
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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0730201A1 (en) * 1995-02-28 1996-09-04 Eastman Kodak Company Sensitized photopolymerizable compositions and use thereof in lithographic printing plates
EP0741333A1 (en) * 1995-05-05 1996-11-06 Bayer Corporation Photopolymerizable compositions
WO1997035232A1 (en) * 1996-03-19 1997-09-25 Minnesota Mining And Manufacturing Company Uv-curable compositions comprising an acyl phosphine oxide and an optical brightener
DE19907957A1 (en) * 1998-02-27 1999-09-02 Ciba Geigy Ag Pigmented photopolymerizable compositions based on ethylenically unsaturated compounds
EP1349006A1 (en) * 2002-03-28 2003-10-01 AGFA-GEVAERT naamloze vennootschap Photopolymerizable composition sensitized for the wavelength range from 300 to 450 nm.

Family Cites Families (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL296772A (en) 1962-03-21
US4088498A (en) 1970-12-28 1978-05-09 Hoechst Aktiengesellschaft Photopolymerizable copying composition
CH559757A5 (en) * 1971-09-01 1975-03-14 Ciba Geigy Ag
DE2822190A1 (en) 1978-05-20 1979-11-22 Hoechst Ag PHOTOPOLYMERIZABLE MIXTURE
US4252887A (en) 1979-08-14 1981-02-24 E. I. Du Pont De Nemours And Company Dimers derived from unsymmetrical 2,4,5-triphenylimidazole compounds as photoinitiators
US4459349A (en) 1981-03-27 1984-07-10 Toyo Boseki Kabushiki Kaisha Photosensitive resin composition
JPS5956403A (en) 1982-09-27 1984-03-31 Mitsubishi Chem Ind Ltd Photomerizable composition
US4622286A (en) 1985-09-16 1986-11-11 E. I. Du Pont De Nemours And Company Photoimaging composition containing admixture of leuco dye and 2,4,5-triphenylimidazolyl dimer
DE3824903A1 (en) 1988-07-22 1990-02-01 Hoechst Ag PHOTOPOLYMERIZABLE MIXTURE AND RECORDING MATERIAL MADE THEREOF
US5273862A (en) 1988-07-29 1993-12-28 Hoechst Aktiengesellschaft Photopolymerizable recording material comprising a cover layer substantially impermeable to oxygen, binds oxygen and is soluble in water at 20°C.
EP0985683A1 (en) 1998-09-09 2000-03-15 Fuji Photo Film Co., Ltd. Photosensitive composition and method for manufacturing lithographic printing plate
JP4130030B2 (en) 1999-03-09 2008-08-06 富士フイルム株式会社 Photosensitive composition and 1,3-dihydro-1-oxo-2H-indene derivative compound
DE19915717A1 (en) 1999-04-08 2000-10-12 Agfa Gevaert Ag Recording material with pigment-colored radiation-sensitive layer
US6335144B1 (en) 1999-04-27 2002-01-01 Fuji Photo Film Co., Ltd. Photopolymerizable composition for short wavelength semiconductor laser exposure
DE19933139A1 (en) 1999-07-19 2001-01-25 Agfa Gevaert Ag Stable pigment dispersion and radiation-sensitive recording material made with it
JP2001033961A (en) 1999-07-23 2001-02-09 Fuji Photo Film Co Ltd Photosensitive composition and method for forming lithographic printing plate
JP4037015B2 (en) 1999-09-22 2008-01-23 富士フイルム株式会社 Photopolymerizable composition, image forming material and planographic printing plate
US20030186165A1 (en) 2002-03-28 2003-10-02 Agfa-Gevaert Photopolymerizable composition sensitized for the wavelength range from 300 to 450 nm

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0730201A1 (en) * 1995-02-28 1996-09-04 Eastman Kodak Company Sensitized photopolymerizable compositions and use thereof in lithographic printing plates
EP0741333A1 (en) * 1995-05-05 1996-11-06 Bayer Corporation Photopolymerizable compositions
WO1997035232A1 (en) * 1996-03-19 1997-09-25 Minnesota Mining And Manufacturing Company Uv-curable compositions comprising an acyl phosphine oxide and an optical brightener
DE19907957A1 (en) * 1998-02-27 1999-09-02 Ciba Geigy Ag Pigmented photopolymerizable compositions based on ethylenically unsaturated compounds
EP1349006A1 (en) * 2002-03-28 2003-10-01 AGFA-GEVAERT naamloze vennootschap Photopolymerizable composition sensitized for the wavelength range from 300 to 450 nm.

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WO2007146209A2 (en) * 2006-06-09 2007-12-21 Dentsply International Inc. Photopolymerizable compositions
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