Abstract: There is described a method of preparing a positive working water-less lithographic plate which comprises a support having an oleophilic surface, there being coated on the support a mixture which comprises as one component an ink-repellant and water-repellant polymer or a mixture of such polymers or polymer precursors, and as the other essential component of the mixture an infra-red or heat sensitive composition selected from (a) an organic solvent soluble diazo compound and an infra-red absorbing compound, (b) a photopolymer and an infra-red absorbing dye, or (c) a mixture of a free-radically polymerisable ethylenically unsaturated compound or compounds together with either a photoinitiator which is infra-red sensitive or an initiator which is heat sensitive together with an infra-red absorbing compound, the ratio of ink-repellant polymer to infra-red or heat sensitive composition (a), (b) or (c) in the mixture being from 20-80 ink repellant polymer to 80-20 infra-red or heat sensitive composition by weight,

Abstract: An imaging member is prepared by applying to a support a heat-sensitive imaging layer which comprises at least one heat-sensitive polymer capable of undergoing transformation from a hydrophilic to hydrophobic state or hydrophobic to hydrophilic state, wherein the transformation occurs such that the activation energy Ea and the Arrhenius pre-exponential factor A associated with the transformation simultaneously fulfill the relationships: ln (A).gtoreq.0.4 Ea+8.84 and ln (A).ltoreq.1.69 Ea-14.37. The imaging member is useful in processless thermal lithographic printing.

Abstract: An aqueous alkaline composition comprising at least one phosphonic acid, at least one polyglycol derivative and at least one glycol. The composition can be used as either a developer or a replenisher for either positive-working or negative-working alkaline developable lithographic printing plates, including thermal plates.

Abstract: A planographic printing plate includes a radiation sensitive layer which may comprise a rubber material. Application of heat causes exposed areas to be vulcanized. The plate may be developed by applying a force to the radiation sensitive layer, for example by rubbing, thereby to remove non-exposed areas.

Abstract: A precursor element for making a lithographic printing plate is composed of a support, an ink receptive thermal conversion inner layer and a sol-gel, ink repellent outer layer. The outer sol-gel layer containes crosslinked colloids derived from certain metal oxides or hydroxides. The plates produced from the ellements are long-running plates that require no post-imaging processing.

Abstract: The present invention is directed to a system and a method for illuminating imaging radiant energy from a laser source onto a spatial modulator. It comprises means or a step of focusing the radiant energy from the laser source at a focal point. There is further provided a mixing means mixing the radiant energy substantially at or downstream the focal point, the mixing means having an input, a plurality of reflecting surfaces and an output, wherein the reflecting surfaces are arranged so that upon entry of the radiant energy into the input of the mixing means the radiant energy is subjected to multiple reflections and at the output the distribution of the radiant energy is substantially uniform.

Abstract: A method for preparing a waterless lithographic plate is disclosed. A mixture that contains a water-repellant release material and a compound that becomes aqueous developable on heating is coated on a support, heated imagewise, and developed to produce the printing plate. Preferred water-repellant release materials are acrylic and methacrylic polymers with fluorinated side chains and silicone containing polymers, especially organo functional siloxanes. Preferred compounds that become aqueous developable on heating are phenolic resins as well as complexes of phenolic resins with quinolinium compounds, benzothiazolium compounds, pyridinium compounds, and imidazoline compounds.

Abstract: An infrared imaging composition contains two essential components, a non-basic infrared radiation absorbing material (such as carbon black), and a phenolic resin that is either mixed or reacted with an o-diazonaphthoquinone derivative. These compositions are useful in positive-working or negative-working imaging elements such as lithographic printing plates that can be adapted to direct-to-plate imaging procedures.

Abstract: A method for making a lithographic printing plate comprising exposing a support, a melonophilic layer and a melonophobic layer, the latter containing crosslinked colloids to a laser beam having an intensity greater than 0.1 mW/.mu..sup.2 for a time sufficient to give a total exposure of about 200 milliJoules/cm.sup.2 or greater. Good printing steps and long running plates are produced.

Abstract: A method for preparing a substrate for a planographic printing plate is disclosed. A liquid that contains water; a soluble alkali metal silicate, preferably sodium silicate; and a dispersed particulate material is coated on a substrate, preferably aluminum or an aluminum alloy, to produce a hydrophilic layer on the substrate. A layer of image material may be coated over the substrate to produce a planographic printing plate. In one embodiment the liquid contains a mixture of two particulate materials: alumina and titanium dioxide.

Abstract: Coated paper stocks for electrostatic imaging comprising a substrate coated on at least one surface with a resin layer comprised of olefinic material and a pin-hole free, continuous coating layer over said resin layer. The continuous layer has a glass transition temperature above 100.degree. C. and is comprised of one or more natural or synthetic film forming polymers. As a single layer this continuous coating layer functions as both a heat protective and imaging layer. In an alternate embodiment two separate coating layers are provided with separate heat protective and imaging functionalities.

Abstract: An improved lithographic printing plate made by coating a support web with a coextensive ink receptive photothermal conversion layer and then overcoating with a ink repellent layer comprising a crosslinked polymeric matrix containing a colloid of an oxide or a hydroxide of a metal selected from the group consisting of beryllium, magnesium, aluminum, silicon, gadolinium, germanium, arsenic, indium, tin, antimony, tellurium, lead, bismuth, a transition metal and combinations thereof, along with a photothermal conversion material.

Abstract: A positive-working lithographic printing plate is used to provide a positive image without a post-exposure baking step and without any floodwise exposure steps. The printing plate includes a layer that is imageable using an infrared radiation laser. This layer consists essentially of a phenolic resin, an infrared radiation absorbing compound, and a dissolution inhibitor that is non-photosensitive and is capable of providing sites for hydrogen bonding with the phenolic moieties of the binder resin.

Abstract: 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.

Abstract: There is described a method of preparing a water-less lithographic plate by coating a positive working photosensitive composition onto an oleophilic base imagewise exposing the plate and developing it to remove the areas of the photosensitive composition which have been light exposed, coating overall the surface of the plate with a layer of a composition which is ink-releasing or when cured becomes ink releasing, then either as a separate step or as a combined step curing the ink-releasing composition or drying the ink-releasing composition and light exposing overall the plate, then redeveloping the plate to remove the photosensitive composition remaining after the first development and any ink-releasing composition overlying the photosensitive composition.

Abstract: A lithographic imaging member, such as a printing plate, has a support having thereon an ink-accepting melanophilic layer and an ink-rejecting siloxane surface melanophobic layer. Within the printing plate is a photothermal conversion material capable of converting irradiation, such as IR radiation, to heat in exposed regions. Also within one of the layers is a compound that upon imaging releases a moiety that facilitates degradation of the surface melanophobic layer. The released moiety can be fluoride ion or a fluoride ion-containing compound. In some imaging members, a barrier layer may be interposed between the two other layers. Such imaging members can be digitally imaged and used for printing without post-imaging processing.

Abstract: There is described a water-less lithographic plate precursor which comprises on an aluminium plate a light-sensitive composition which comprises a polymer with hydroxy functional groups, an acid generator which when light exposed yields an acid together with a silyl ether of general formula (I), where Rf is a fluoroaliphatic group having 3 to 10 carbon atoms, Y is oxygen, SO.sub.2, carbonyl or a direct link, X is N R.sub.4 where R.sub.4 is hydrogen or lower alkyl having up to six carbon atoms or is a direct link, each of R.sub.1, R.sub.2 and R.sub.3 are lower alkyl groups having up to six carbon atoms and R.sub.5 is a lower alkyl group having up to six carbon atoms.

Abstract: A lithographic printing plate precursor comprising on a support a radiation sensitive composition which comprises (1) a novolac resin, (2) a condensing agent for the novolac resin which is either a methylol polyvinyl phenol compound or a bishydroxymethyl compound, (3) a radiation sensitive latent acid generating compound, and (4) an infra-red sensitizing dye.

Abstract: This subject invention relates to novel hydrazide compounds useful as dot-promoting agents in photographic image systems, methods for making them, and to photographic materials which comprise these compounds.

Abstract: A positive-working lithographic printing plate is used to provide a positive image without a post-exposure baking step and without any floodwise exposure steps. The printing plate includes an imaging layer that is imageable using an infrared radiation laser. The imaging layer consists essentially of a phenolic resin and an infrared radiation absorbing compound.