Abstract:
Lithographic printing plate precursor comprising: a) an untreated or pretreated substrate and b) a radiation-sensitive coating comprising: (i) at least one polymeric binder soluble or swellable in aqueous alkaline developers; (ii) at least one free-radical polymerizable monomer and/or oligomer comprising at least one non-aromatic C-C double bond and at least one SH group in the molecule; and (iii) a radiation-sensitive initiator or initiator system for free-radical polymerization, wherein component (ii) has the formula (I) wherein each R 1a , R 1b and R 1c is independently selected from H, C 1 -C 6 alkyl, C 2 -C 8 alkenyl, aryl, halogen, CN and COOR 1d , wherein R id is H, C 1 -C 18 alkyl, C 2 -C 8 alkenyl, C 2 -C 8 alkynyl or aryl; and Z is an aliphatic, heterocyclic or heteroaromatic spacer or a combination of two or more thereof, wherein Z can optionally comprise one or more additional SH groups and/or one or more additional non-aromatic C-C double bonds; and each Z 1 is independently selected from a single bond, formulae (Ia), (Ib), (Ic), (Id), (Ie), (If), (Ig), (Ih), (Ij), (Ik), (Im), (In), (Io), (Ip), (Iq), (Ir), (Is), (It), (Iu), (Iv), wherein R 2a , R 2b and R 2c are independently selected from H, C 1 -C 6 alkyl and aryl, Z 2 is selected from a single bond, O, S and NR 2c , Z 3 is a single bond which is connected to Z, b is an integer from 1 to 10 and c is an integer from 1 to 3.
Abstract:
Radiation-sensitive composition comprising (a) at least one photopolymerizable compound with at least one ethylenically unsaturated group accessible to a free-radical polymerization, wherein the at least one photopolymerizable compound has a molecular weight of 3,000 or less and can be obtained by reacting a diisocyanate with (I) an ethylenically unsaturated compound with a hydroxy group, and at the same time (ii) a saturated organic compound with an NH group and an OH group, wherein the reactants are used in amounts according to the following condition: Number of moles of isocyanate groups ≤ number of moles of OH plus NH groups; (b) at least one sensitizer which absorbs radiation from the wavelength range of 250 to 450 nm of the electromagnetic spectrum and is selected from: dihydropyridines of formula (I) and oxazole derivatives of formula (II): (II) (c) at least one coinitiator capable of forming free radicals together with the sensitizer (b) and selected from 2,2’, 4,4’, 5’5-hexaarylbiimidazoles, compounds with at least one photolytically cleavable trihalogenmethyl group, diaryliodonium salts, triarylsulfonium salts and N-heterocyclic compounds with at least one nitrogen atom in the ring, having an oxy substituent at least one ring nitrogen atom, and mixtures of the above compounds; and (d) optionally one or more components selected from alkali-soluble binders, colorants, exposure indicators, plasticizers, chain transfer agents, leuco dyes, surfactants, inorganic fillers and thermopolymerization inhibitors; with the proviso that the radiation-sensitive composition does not comprise a metallocene.
Abstract:
The invention relates to a process for the production of a heat-sensitive imageable element comprising: (a) providing a substrate, (b) applying a first coating solution, comprising at least one photothermal conversion material, at least one polymer A soluble or swellable in an aqueous alkaline developer and at least one solvent, (c) drying, (d) applying a second coating solution, comprising at least one cross-linkable polyfunctional enolether, at least one polymer B comprising hydroxy groups and/or carboxy groups, and at least one solvent, wherein the polymer used in the first coating solution does not dissolve in this solvent, wherein the second coating solution does not contain a photothermal conversion material, and (e) drying at a temperature of at least 60°C.
Abstract:
The process for gumming lithographic printing plates comprises (a) providing a lithographic printing plate; (b) providing a gumming solution comprising (I) water and (II) at least one component selected from water-soluble starch and water-soluble starch derivatives; (c) applying the gumming solution onto the printing plate provided in step (a), and is characterized in that the gumming solution has a pH value >7.
Abstract:
Infrared absorbing compounds in which the anion is selected from the group consisting of 5-isatinsulfonate, 10-camphorsulfonate, and 4,5-dihydroxy-1,3-benzenedisulfonate are disclosed. Negative-working imageable elements containing these compounds have improved dot stability.
Abstract:
Heat-sensitive element comprising a) an optionally pretreated substrate; b) a positive working coating comprising (i) at least 40 wt.-%, based on the dry weight of the coating, of at least one polymer soluble in aqueous alkaline developer selected from novolak resins, functionalized novolak resins, polyvinylphenol resins, polyvinyl cresols and poly(meth)acrylates with phenolic and/or sulfonamide side groups, (ii) 01-20 wt.-%, based on the dry weight of the coating, of at least one (C 4 -C 20 alkyl)phenol novolak resin insoluble in aqueous alkaline developer, and (iii) optionally at least one further component selected from polymer particles, surfactants, contrast dyes and pigments, inorganic fillers, antioxidants, print-out dyes, carboxylic acid derivatives of cellulose polymers, plasticizers and substances capable of absorbing radiation of a wavelength from the range of 650 to 1,300 nm and converting it into heat.
Abstract:
Radiation-sensitive element comprising: (a) one or more types of monomers each comprising at least one ethylenically unsaturated group accessible to a free-radical polymerization, (b) at least one sensitizer, (c) at least one coinitiator capable of forming free radicals together with the sensitizer (b) and selected from the following classes of compounds: metallocenes; 1,3,5-triazine derivatives with one to three CX3 groups, wherein X represents chlorine or bromine; peroxides; hexaarylbiimidazoles; oxime ethers; oxime esters; N-aryl glycines and derivatives thereof; thiol compounds; N-aryl, S-aryl and O-aryl polycarboxylic acids with at least 2 carboxyl groups of which at least one is bonded to the N, S or O atom of the aryl unit; alkyltriarylborates; benzoin ethers; benzoin esters; trihalogenomethylarylsulfones; amines; N,N-dialkylaminobenzoic acid esters; aromatic sulfonyl halides; trihalogenomethylsulfones; imides; diazosulfonates; 9,10-dihydroanthracene derivatives; a-hydroxy and a-amino acetophenones; and (d) optionally one or more components selected from alkali-soluble binders, colorants, exposure indicators, plasticizers, chain transfer agents, leuco dyes, surfactants, inorganic fillers and thermopolymerization inhibitors characterized in that the at least one sensitizer is an oxazole derivative of the formula (I), wherein each R , R and R is independently selected from a halogen atom, an optionally substituted alkyl group, an optionally substituted aryl group, which may also be fused, an optionally substituted aralkyl group, a group -NR R and a group - , wherein R and R are independently selected from a hydrogen atom, an alkyl, aryl or ralkyl group, R is an alkyl, aryl or aralkyl group or a hydrogen atom and k, m and n are independently 0 or an integer from 1 to 5.
Abstract:
A technique for profiling a color printing device employs a modified Neugebauer color mixing model. The modeling technique makes use of a variable dot gain value and "n factor." The variable dot gain adjustment value may vary according to the particular tristimulus channel under evaluation. In addition, the variable dot gain value may vary according to the particular Neugebauer primary over which a halftone dot is printed. Accordingly, the technique may rely on an array of different dot gain values and n factors that correspond to different combinations of color channels and overprint conditions. As a further feature, the techniques may rely on a dot gain formula that relates halftone dot variation, i.e., fringe thickness, to the size of the halftone dot. This relationship tends to produce a dot gain model that more closely resembles the actual dot gain behavior on a printing press.
Abstract:
A radiation-sensitive patterning composition comprising: (1) at least one acid generating compound selected from compounds of formula (I) and formula (II) wherein: R1, R2, R3, R4, R5, and R6, are independently selected from the group consisting of hydrogen, nitro, hydroxyl, carbonyl, halogen, cyano, unsubstituted and substituted alkyl groups, unsubstituted and substituted cycloalkyl groups; unsubstituted and substituted alkoxy groups, and unsubstituted and substituted aryl groups; wherein: X is an onium ion selected from the group consisting of diazonium, iodonium, sulfonium, phosphonium, bromonium, chloronium, oxysulfoxonium, oxysulfonium, sulfoxonium, selenium, tellurium and arsenium; and n is an integer from 4 to 100; (2) at least one cross-linking agent cross-linkable by an acid; (3) at least one polymer compound capable of reacting with the cross-linking agent; and (4) at least one infrared absorbing compound.
Abstract:
Techniques for providing accurate output measurement and calibration in soft proofing systems incorporate one or more features to promote controlled viewing conditions. For example, a soft proofing system is described in which an administator can control the proofing process by limiting or restricting the ability to view an image until acceptable viewing conditions have been met. For example, the ability to view the image can be restricted until the viewing station has been calibrated using a calibration device known to support calibration of the viewing station to less than or equal to a maximum of error. With controlled viewing conditions and, more particularly, controlled calibration conditions, the soft proof reviewers obtain more uniform output. In this manner, the system can provide safeguards to ensure that the images viewed at the viewing station have acceptable color accuracy.