Abstract:
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 acid generator which is sensitive to UV radiation; (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 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.
Abstract:
A method of producing a printing plate comprises: (a) providing a printing plate precursor comprising a topmost etchable first layer and a second layer located below the first layer, wherein the first and second layers have different affinities for at least one printing liquid; (b) imagewise providing atomized fluid particles in an interaction zone located above the surface of the first layer; and (c) imagewise directing laser energy into the interaction zone, wherein the laser energy has a wavelength which is substantially absorbed by the atomized fluid particles in the interaction zone, and the absorption of the laser energy causes the atomized fluid particles to imagewise impart kinetic energy to and etch the first layer. Lithographic and flexographic printing plates may be prepared according to this method, including waterless plates, negative-and positive-working plates, and processless plates.
Abstract:
The present invention includes an imageable element, which can be: (a) an imageable element comprising an imaging layer which comprises: an aromatic diazonium salt containing compound having an alkoxy substituent and an aromatic diazonium salt containing compound free of an alkoxy substituent; a polyvinyl acetal binder; and a sheet substrate; or (b) an imageable element comprising an imaging layer which comprises: an aromatic diazonium salt containing compound having an alkoxy substituent and an aromatic diazonium salt containing compound free of an alkoxy substituent; and a sheet substrate. The imaging layer includes a total aromatic diazonium salt containing compound content of at least 10 weight percent. The molar ratio of the aromatic diazonium salt containing compound having an alkoxy substituent to the aromatic diazonium salt containing compound that is free of an alkoxy substituent is from about 1.0:1 to 70:1. Upon imagewise exposure and development, an imaged element is obtained.
Abstract:
A method for manufacturing a microporous film comprising the steps of: (a) providing a first polymer which is a hydrophobic thermoplastic polymer and a second polymer which is a hydrophilic polymer or copolymer of N-vinylpyrrolidone; (b) dissolving said first and second polymers in a solvent system which is compatible with both polymers, said solvent system comprising a blend of an aprotic organic solvent and an alcohol; (c) coating the resulting solution on a support; (d) effecting at least a partial drying of the resulting coating; and (e) washing the coating in an aqueous medium so as to extract at least 50% by weight of the said second polymer. Image accepting members comprising a microporous film made by the above method, and preferably comprising a support which is also microporous.
Abstract:
A polyvinyl acetal copolymer compound comprises the units A, B, C and D, wherein A is present in an amount of 0.5 to 30 wt.-% and is of the formula 1 wherein R is hydrogen, C1-C6 alkyl, nullCHnullCHCOOH or 2 B is present in an amount of 5 to 35 wt.-% and is of the formula 3 C is present in an amount of 10 to 55 wt.-% and is of the formula 4 wherein R1 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 halogen atoms, amino, methoxy, ethoxy, methyl and ethyl groups, or is a group ZnullNR2nullCOnullYnullCOOH, wherein Z is an aliphatic, aromatic or araliphatic spacer group, R2 is hydrogen or an aliphatic, aromatic or araliphatic moiety and Y is a saturated or unsaturated chain- or ring-shaped spacer group, and unit C may have one or more occurrences in the copolymer with various moieties R1 independent of one another; and D is present in an amount of 10 to 40 wt.-% and is of the formula 5 wherein X is C1-C6 alkylene, a 5 or 6 membered saturated carbocyclic moiety optionally substituted with one or more substituents selected from the group consisting of C1-C4 alkyl, C1-C4 alkoxy or halogen, a 5 or 6 membered saturated heterocyclic moiety which comprises in the nucleus one or more heteroatoms selected from oxygen, nitrogen and sulfur, or a group of the formula I 6 wherein n is an integer from 0 to 4 and each R3 is independently selected from the group consisting of C1-C4 alkyl, halogen or C1-C4 alkoxy. A radiation-sensitive composition useful in a lithographic printing plate comprises (i) the above-described polyvinyl acetal copolymer; and (ii) a light-to-heat transformer compound.
Abstract:
The present invention provides an aluminum alloy support body for a presensitized plate in which the uniformity of the grained surface due to electrochemical etching is further improved, and a method of producing the same. The aluminum alloy support body for the presensitized plate according to the present invention has a composition comprising 0.1 to 0.7% by weight of Fe; 0.01 to 0.2% by weight of Si; 0.005 to 1.0% by weight of one or more rare earth elements; and the balance of Al and unavoidable impurities. In the present invention, the aluminum alloy support body may further contain 0.005 to 0.1% by weight of Ni and 0.005 to 0.3% by weight of one or more rare earth elements. One or more elements of Ce, La and Nd can be selected as the rare earth elements.
Abstract:
An optical head having a laser source of beams at an input end and image forming beams at an output end and a plurality of optical components arranged along the beams between the input and output ends to obtain an image on a photosensitive printing plate from the beams. The optical components include reflecting surfaces adapted to fold the beams several times between the input and output ends times in such a way as to reduce the width and height of the optical head. The folded beams are located in a plurality of parallel surfaces perpendicular to the image formed on the photosensitive printing plate. The optical head further includes optical components adapted to adjust the width, location, orientation and intensity of the image from the beams.
Abstract:
A direct-to-press imaging method comprises: (a) applying an imageable coating to a printing cylinder, wherein the imageable coating comprises a composition such as a thermally switchable polymer which changes affinity for a printing fluid upon exposure to imaging radiation such as infrared radiation delivered imagewise via a laser, and the imageable coating is substantially insoluble in the printing fluid; (b) imagewise exposing the imageable coating to actinic radiation to obtain an imaged coating; (c) printing a plurality of copies of an image from the imaged coating; and (d) reapplying the imageable coating as desired by repeating steps (a) through (c) at least once without substantially removing the prior imaged coating before reapplying the imageable coating.
Abstract:
A precursor that may be imaged by heat is made up of a substrate, for example a copper board, and a composite layer structure composed of two layers. Preferably, the first layer is composed of an aqueous developable polymer mixture containing a photothermal conversion material, which is contiguous to the substrate. The second layer of the composite is composed of one or more non-aqueous soluble polymers, which are soluble or dispersible in a solvent which does not dissolve the first layer. The precursor is exposed with an infrared laser or a thermal print head, and upon aqueous development, the exposed regions are removed, revealing regions of the substrate surface able to be etched or otherwise treated. The second layer may also contain a photothermal conversion material. Alternatively, the composite layer may be free of photothermal conversion material when thermal imaging is carried out using a thermal print head. The precursor may be used, for example, as a mask precursor or electronic part precursor.
Abstract:
A thermally imagable article comprises a substrate on which is coated a positive working heat-sensitive composition comprising a hydroxyl group-containing polymer and a heat-labile moiety which decreases the developer solubility of the composition as compared to the developer solubility of the composition without the heat-labile moiety, wherein the heat-sensitive composition does not comprise an acid generating moiety. The invention also provides novel positive working compositions comprising heat-labile moieties, and imagable articles comprising said compositions.