摘要:
A lithographic printing plate precursor comprises a substrate, a free radical polymerizable photosensitive layer comprising a light-sensitive composition on the substrate, and a water-soluble overcoat layer on the photosensitive layer, wherein the overcoat layer comprises polyvinyl alcohol, and a further component that is not amphoteric and is poly(1-vinylimidazole) or a copolymer of 1-vinylimidazole and at least one further monomer. The photosensitive layer comprises a free radical polymerizable component and a photoinitiator.
摘要:
A radiation-sensitive composition comprises: (i) at least one component capable of absorbing IR radiation; and (ii) a diazonium polycondensation product soluble in an organic solvent; with the proviso that the composition does not contain components capable of reacting with decomposition products produced from IR radiation exposure of the diazonium polycondensation product. The composition may additionally comprise a polymeric binder of the type useful for conventional negative-working printing plates. The composition is suitable for preparing thermally imageable printing plate precursors and printing plates and may also be used in a method for providing an image on such plate precursors and printing plates.
摘要:
The present invention relates to particular acetal copolymers and radiation-sensitive compositions comprising said copolymers and, inter alia, are excellently suitable for the production of lithographic printing plates. In particular, the invention relates to acetal copolymers containing furylvinylidene, thienylvinylidene or pyrrolylvinylidene.
摘要:
Binders useful in photosensitive compositions contain 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, 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.
摘要:
This invention relates to a binder containing the units A, B, C, D and E, wherein A is present in an amount of 10 to 60 mole % and is of the formula ##STR1## B is present in an amount of 1 to 30 mole % and is of the formula ##STR2## C is present in an amount of 5 to 60 mole % and is of the formula ##STR3## D is present in an amount of 0 to 60 mole % and is of the formula ##STR4## E is present in an amount of 1 to 40 mole % and is of the formula ##STR5## wherein X is an aliphatic, aromatic or araliphatic spacer group, R.sup.1 is hydrogen or an aliphatic, aromatic or araliphatic group, R.sup.2, R.sup.3 and R.sup.4 are hydrogen or alkyl groups with carbon numbers of from 1 to 18 and Y is a saturated or unsaturated chain- or ring-shaped spacer group, and photosensitive compositions containing this binder.
摘要:
The present invention relates to a light-sensitive composition containing: (i) at least one diazonium polycondensation product or at least one system that can be radically polymerized and consists of photoinitiators and unsaturated compounds which can be radically polymerized or at least one hybrid system consisting of a diazonium polycondensation product and a system that can be radically polymerized and consists of photo initiators and unsaturated compounds which can be radically polymerized, (ii) at least one binding agent and optionally one or more exposure indicators, one or more dyes for increasing the image contrast and one or more acids for stabilizing the light-sensitive composition which is characterized in that the binding agent essentially consists of units (A, B, C, D), whereby A corresponds to formula (I), B corresponds to formula (II), C corresponds to formula (III) and D corresponds to formula (IV). The invention also relates to the use thereof for coating printing plates. The invention further relates to printing plates which are coated with said light-sensitive composition.
摘要:
A process for making thermally imageable negative working compositions comprising the steps of: (1) providing a patterning composition layer on a substrate, said patterning composition comprising: (a) at least one thermal-generator acid generator, (b) at least one cross-linking resin or compound; (c) at least one binder resin comprising a polymer containing at least one reactive pendent group selected from the group, consisting of hydroxyl, carboxylic acid, sulfonamide, alkoxymethylamide and mixtures thereof; and (d) at least one infrared absorber; (2) subjecting the patterning composition layer to a two-stage radiation exposure; (a) one stage being a flood UV-exposure; and (b) the other stage being a imagewise infrared exposure stage; (3) treating the exposed patterning composition with heat energy; and (4) developing the heat treated, exposed patterning composition with an aqueous alkaline developer to remove the non-imaged areas of the patterning composition and leaving the imaged areas substantially unaffected.
摘要:
A thermally imageable element, useful as a lithographic printing plate precursor is disclosed. The element comprises a hydrophilic substrate; an underlayer comprising a first polymeric material; and an ink-receptive top layer comprising a second polymeric material and a solubility-suppressing component. The solubility-suppressing component may be a separate dissolution inhibitor compound and/or the second polymeric material may also function as a solubility-suppressing component. On thermal exposure the exposed regions of the top layer becomes more readily soluble in an aqueous developer, allowing the developer to remove the top layer and reveal the surface of the hydrophilic substrate. The lithographic printing plate thus formed has excellent properties, including the absence of sludging of the developer.
摘要:
A heat-sensitive composition, for example a coating on a lithographic printing plate, comprises a carboxylic acid derivative of a cellulosic polymer. The composition may contain a radiation absorbing compound and suitable electromagnetic radiation, preferably infra-red radiation, may be used to heat the composition imagewise. The presence of the cellulosic polymer enhances resistance to certain organic liquids.
摘要:
This invention relates to polyvinyl acetals containing the units A, B, C and D, whereinA is present in an amount of 0.5 to 20 wt.-% and is of the formula ##STR1## B is present in an amount of 15 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 an alkyl group with up to 4 carbons, which is optionally substituted by an acid group, or a phenyl group, to which an acid group is attached, wherein the phenyl group optionally comprises 1 to 2 further substituents selected from halos, amino, methoxy, ethoxy, methyl and ethyl groups, or is a group X--NR.sup.6 --CO--Y--COOH, wherein X is an aliphatic, aromatic or araliphatic spacer group, R.sup.6 is hydrogen or an aliphatic, aromatic or araliphatic moiety and Y is a saturated or unsaturated chain- or ring-shaped spacer group, and this unit C may be contained several times with various moieties R.sup.1 independent of one another, and D is present in an amount of 25 to 70 wt.-% and is of the formula ##STR4## wherein n is an integer from 1 to 3 andR.sup.2 and R.sup.3 are a hydrogen or a methyl group, andR.sup.4 and R.sup.5 independent of one another are alkyl groups having no more than 4 carbons or R.sup.4 and R.sup.5, together with the two carbons they are attached to, represent a 5- or 6-membered carbocyclic ring.In addition, photosensitive compositions containing these polyvinyl acetals are described.