Abstract: A negative-working lithographic printing plate precursor can be imaged with infrared radiation and processed in a single step using a single processing solution having a pH of from about 3 to 11. The precursor has a primary polymeric binder that comprises recurring units derived from one or more N-alkoxymethyl(meth)acrylamides, provided that such recurring units are present in the primary polymeric binder in an amount of at least 10% based on the total dry primary polymeric binder weight. In addition, the primary polymeric binder is present in an amount of from about 12 to about 70% based on total imageable layer dry weight. The imaged precursor can be processed off-press or on-press.

Abstract: A negative-working lithographic printing plate precursor can be imaged with infrared radiation and processed in a single step using a single processing solution having a pH of from about 3 to 11. The precursor has a primary polymeric binder that comprises recurring units derived from one or more N-alkoxymethyl(meth)acrylamides, provided that such recurring units are present in the primary polymeric binder in an amount of at least 10% based on the total dry primary polymeric binder weight. In addition, the primary polymeric binder is present in an amount of from about 12 to about 70% based on total imageable layer dry weight. The imaged precursor can be processed off-press or on-press.

Abstract: The present invention provides an imageable member having an imageable layer including a heat-sensitive ionomer characterized by a net positive or negative charge, and a photothermal conversion material. The photothermal conversion material includes carbonaceous particles having thereon both an organic moiety including an ionic substituent having like charge as the ionomer, and a group represented by the formula —X-[NIon]p-Rterminal; wherein X represents an aromatic group or an alkyl group, NIon represents a non-ionic, non-ionizable group, Rterminal represents hydrogen, an aromatic group, an alkoxy group, or an alkyl group, and p is an integer from 1 to about 500. The heat-sensitive ionomer and modified carbonaceous particles can be formulated in water or water-miscible solvents without agglomeration.

Abstract: A negative-working radiation-sensitive composition includes a polymeric binder comprising a polymer backbone and having attached thereto a carbazole derivative represented by the following Structure (I): wherein Y is a direct bond or a linking group, and R1 to R8 are independently hydrogen, or an alkyl, alkenyl, aryl, halo, cyano, alkoxy, acyl, acyloxy, or carboxylate groups, or any adjacent R1 through R8 groups can together form a carbocyclic or heterocyclic group or a fused aromatic ring. The composition can be sensitive to radiation having a maximum wavelength of from about 150 to about 1500 nm, and can be used to prepare negative-working imageable elements that be imaged and developed as lithographic printing plates.

Abstract: A method for reducing start up blinding in no-process lithographic printing plates is disclosed. An imageable element, comprising an imageable layer over a substrate, is thermally imaged. The imageable layer comprises a thermally sensitive polymer that comprises quaternary ammonium salts of carboxylic acids. Following imaging, the surface of the imaged imageable is contacted with an aqueous solution comprising 0.05 wt % to about 5 wt % of an added organic acid having a pKa of about 1 to about 6. This reduces the amount of waste produced by the printing process by reducing the number of unusable sheets produced during the “make ready” process.

Abstract: An imaging member, such as a negative-working printing plate or on-press cylinder, can be prepared using a hydrophilic imaging layer comprising a hydrophilic heat-sensitive polymer containing a crosslinking agent comprising ionic groups and epoxy groups. This polymer may comprise quaternary ammonium carboxylate groups which may include at least one substituted-alkylene(C1-C3)-phenyl group. The imaging member also includes an infrared radiation sensitive material to provide added sensitivity to heat that can be supplied by laser irradiation in the IR region. The heat-sensitive polymer may be “switchable” in response to heat, and provides a lithographic image without wet processing.

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: The present invention relates to printing plate coating compositions comprising: (a) a carbon pigment dispersible in water; (b) at least one polymer comprising at least one ionomeric polymer subunit; and (c) at least one high molecular weight thickening agent which shows pseudoplastic behavior. The printing plate precursor of this invention is prepared by coating a printing plate substrate with the coating composition.

Abstract: A direct-to-press imaging method comprises:

Abstract: An imaging member, such as a negative-working printing plate or on-press cylinder, can be prepared using a hydrophilic imaging layer comprising a hydrophilic heat-sensitive polymer containing a crosslinking agent comprising ionic groups and epoxy groups. This polymer may comprise quaternary ammonium carboxylate groups which may include at least one substituted-alkylene(C1-C3)-phenyl group. The imaging member also includes an infrared radiation sensitive material to provide added sensitivity to heat that can be supplied by laser irradiation in the IR region. The heat-sensitive polymer may be “switchable” in response to heat, and provides a lithographic image without wet processing.

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: The present invention relates to printing plate coating compositions comprising: (a) a carbon pigment dispersible in water; (b) at least one polymer comprising at least one ionomeric polymer subunit; and (c) at least one high molecular weight thickening agent which shows pseudoplastic behavior. The printing plate precursor of this invention is prepared by coating a printing plate substrate with the coating composition.

Abstract: A direct-to-press imaging method comprises: