Abstract:
Lithographic printing plates are provided by imagewise exposing negative-working lithographic printing plate precursors having a negative-working radiation-sensitive imageable layer, followed by contacting with a processing solution that has a pH of at least 7 and up to and including 11. This processing solution also includes component (1) that is a nitrogen-containing base having an atmospheric pressure melting point of at least 40° C.; component (2) that is a non-ionic surfactant that independently has an atmospheric pressure melting point, glass transition temperature, or pour point of at least 40° C.; component (3) that is a hydroxy-containing solution promoter; and component (4) that is a hydrophilic surface protective compound. The method is carried out in a manner such that the exposed and processed precursor is not further treated with any liquid (such as gumming or rinsing solution) between processing and mounting onto a printing press.
Abstract:
Negative-working imageable element can be used to provide lithographic printing plates. The imageable element has a suitable radiation-sensitive imageable layer and a water-soluble overcoat disposed on the imageable layer. This overcoat comprises at least one poly(vinyl alcohol) having a saponification degree of at least 90%, an alkoxylation product of an alkanol, and either a 2-sulfonato succinic acid dialkylester or an alkoxylation product of a 1,4-butanediol.
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 R1, R2 and R3 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 —NR4R5 and a group —OR6, wherein R4 and R5 are independently selected from a hydrogen atom, an alkyl, aryl or ralkyl group, R6 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:
The present invention relates to binders and photosensitive compositions comprising said binders. The binder comprises units A, B, C and D, wherein A is present in an amount of 0.5 to 15 wt. % and is of the formula ##STR1## B is present in an amount of 10 to 35 wt. % and is of the formula ##STR2## C is present in an amount of 10 to 50 wt. % and is of the formula ##STR3## wherein R.sup.1 is methyl, ethyl, propyl or isopropyl, and D is present in an amount of 25 to 70 wt. % and is of the formula ##STR4## wherein n is an integer of from 1 to 3 and R.sup.2, R.sup.3 are hydrogen or methyl and R.sup.4 is alkyl, aralkyl or aryl.
Abstract:
A lithographic printing plate precursor comprises an imagable layer comprising a free radically polymerizable component, an initiator composition capable of generating free radicals upon exposure to imaging infrared radiation, an infrared radiation absorbing dye comprising an infrared radiation absorbing cation and a counter anion, and a polymeric binder. The salt formed between the infrared radiation absorbing cation and a tetraphenyl borate has solubility in 2-methoxy propanol at 20° C. that is greater than or equal to 3.5 g/l. The use of these infrared radiation absorbing dyes in the imagable layers provides a reduced tendency of these dyes to crystallize in the presence of tetraaryl borate counter anions.
Abstract:
Lithographic printing plate precursor comprising (a) a lithographic substrate with a hydrophilic surface and (b) a radiation-sensitive coating on the hydrophilic surface comprising (i) one or more types of monomers and/or oligomers and/or polymers, each comprising at least one ethylenically unsaturated group accessible to a free radical polymerization, (ii) at least one sensitizer, and at least one coinitiator capable of forming free radicals together with the sensitizer (ii); characterized in that the at least one sensitizer is an oligomeric or polymeric compound comprising the following structural unit (Formula (I)), wherein π1 is an aromatic or heteroaromatic unit or a combination of the two so that a conjugated n-system is present between the two groups Z in structure (I), each Z independently represents a heteroatom, each R1 and R2 is independently selected from a halogen atom, an alkyl, aryl, alkylaryl or aralkyl group, a group —NR3R4 and a group —OR5, each R3, R4 and R5 is independently selected from an alkyl, aryl, alkylaryl and aralkyl group, a and b independently represent 0 or an integer from 1 to 4, n has a value of >1 and AS is an aliphatic spacer.
Abstract translation:该平版印刷版原版包括(a)具有亲水表面的平版印刷基材和(b)亲水表面上的辐射敏感涂层,其包含(i)一种或多种类型的单体和/或低聚物和/或聚合物, 至少一种可自由基聚合的烯键式不饱和基团,(ii)至少一种敏化剂和至少一种能够与敏化剂(ii)一起形成自由基的共引发剂; 其特征在于所述至少一种敏化剂是包含以下结构单元(式(I))的低聚或聚合化合物,其中p1是芳族或杂芳族单元或两者的组合,使得共轭的n体系存在于 结构(I)中的两个基团Z,每个Z独立地表示杂原子,每个R 1和R 2独立地选自卤素原子,烷基,芳基,烷基芳基或芳烷基,基团-NR 3 R 4和基团-OR 5,各自 R 3,R 4和R 5独立地选自烷基,芳基,烷基芳基和芳烷基,a和b独立地表示0或1-4的整数,n的值> 1,AS是脂肪族间隔基。
Abstract:
An apparatus and related method for preparing a lithographic web during manufacturing by incorporating a cleaning device cleaning device capable of being in contact with one or more web rollers. The cleaning device including a cleaning applicator to apply the cleaning solution such that the cleaning solution connected to the cleaning applicator, and a controller to move the applicator from an operational mode to a self-cleaning mode.
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:
Radiation-sensitive element comprising (a) a substrate with at least one hydrophilic surface and (b) a radiation-sensitive coating on at least one hydrophilic surface of the substrate, wherein the coating comprises: (i) at least one free-radical polymerizable monomer and/or oligomer and/or polymer with at least one ethylenically unsaturated group each, (ii) at least one absorber selected from photoinitiators and sensitizers, which is capable of absorbing radiation of a wavelength in the range of 250 to 1,200 nm and (iii) at least one stabilizer comprising in its molecule at least one group capable of inhibiting free-radical polymerization, and at least one other group capable of sorption at the hydrophilic surface of the substrate.
Abstract:
Radiation-sensitive elements are described whose radiation-sensitive coating comprises both a photopolymerizable oligomer with a biuret structural unit and a photopolymerizable phosphazene oligomer.