Abstract:
Lithographic printing is accomplished using wet lithographic printing plates that include a protective layer providing protection against handling and environmental damage, extension of plate shelf life, and entrainment of debris generated by ablation. The layer washes away during the printing make-ready process, effectively cleaning the plate and disappearing without the need for a separate removal process.
Abstract:
A laser imageable direct write printing member for use with a laser producing laser radiation comprising a flexible sheet of plastic having first and second surfaces serving as a film substrate. A vacuum-deposited laser ablative coating is carried by said first surface formed of a metal selected from a group consisting of titanium, zirconium, aluminum hafnium and alloys thereof.
Abstract:
A waterless or driographic printing plate which can be thermally imaged by an infrared laser is composed of a substrate; a thermal imaging layer containing a photothermal conversion material, such as an infrared absorbing material, and a thermoplastic polyurethane with pendent allyl groups; and a crosslinked silicone polymer top layer. It was discovered that when the imaging layer contains an allyl functional polyurethane mixed with an infrared absorbing dye or pigment, the polymeric layer will have enhanced solubility in certain solvents when exposed to infrared radiation. In addition, the polymeric layer continues to exhibit excellent adhesion to the silicone in unexposed areas so that the infrared absorbing layer can endure development with a suitable organic solvent, or a solvent mixture. Mild brushing or rubbing with the developing solvent readily removes laser-struck portions of the infrared imaging layer while unexposed areas remain firmly intact.
Abstract:
The present invention provides a quenching overcoat useful for application onto a lithographic printing plate, the overcoat having incorporated therein a water or fountain soluble or dispersible crystalline compound. The overcoat may be used as an oxygen barrier and/or to provide a non-tacky surface on the printing plate. By the incorporation of the crystalline compound, on-press removability of the overcoat is facilitated.
Abstract:
A lithographic element comprises a support and a hydrophilic layer. The hydrophilic layer contains fine particles of silicon dioxide dispersed in gelatin. The particles have an average particle size in the range of 0.1 to 10 .mu.m. The particles are contained in the layer in an amount of not more than 2 g per m.sup.2. The gelatin has an average molecular weight in the range of 10,000 to 300,000.
Abstract:
Apparatus and methods for imaging lithographic plates using laser devices that emit in the near-infrared region, and plates suitable for imaging with the apparatus and methods. Laser output either ablates one or more plate layers or physically transforms a surface layer, in either case resulting in an imagewise pattern of features on the plate. The image features exhibit an affinity for ink or an ink-abhesive fluid that differs from that of unexposed areas.
Abstract:
Lithographic printing plates suitable for imaging by means of laser devices that emit in the near-infrared region. Laser output ablates a titanium layer sandwiched between an oleophobic or hydrophilic layer and a polyester layer, resulting in an imagewise pattern of features on the plate. The image features exhibit an affinity for ink or an ink-abhesive fluid that differs from that of unexposed areas.
Abstract:
A heat mode recording material comprising a support and a heat sensitive layer positioned on the support, the heat sensitive layer comprising: (a) an ionomer resin obtained by ionically cross-linking with at least one metal ion, a copolymer comprising an alpha-olefin and an alpha-methylene aliphatic monocarboxylic acid; and (b) a hydrophilic binder. A method for recording image information using the above material is also disclosed and claimed.
Abstract:
1,177,527. Photo-sensitive materials. GAF CORP. April 14, 1967 [April 15, 1966; July 5, 1966], No. 17346/67. Heading G3C. A photo-sensitive material comprises a metal support coated with an alkali-soluble intermediate layer consisting of a copolymer with 80-99% mole per cent of acrylate units and 1-20% of acrylic acid units, and with a layer containing a quinone diazide and a water-insoluble, alkali-resistant polymer. Specified polymers are polyvinyl acetate, polymethyl acrylate or methacrylate, cellulose ethers and esters and phenolmodified coumarone-indene resins. The support may be aluminium, copper, coated aluminium or chromium copper-aluminium. The material is imagewise exposed and developed with a polyhydric alcohol to remove the un-exposed areas to produce a negative printing plate; the copolymer layer being hydrophilic. If the developer contains an amine, the copolymer and light-sensitive layers are removed in the exposed areas and the bared metal surface etched to produce either a positive or a negative printing plate.