Abstract: A radiation-sensitive medium comprises hydrophilic polymer particles, the particles comprising a thermally softenable hydrophobic polymer, a hydrophilic polymer and a bonding compound capable of chemically bonding to the hydrophobic polymer and to the hydrophilic polymer. The radiation-sensitive medium further may comprise a substance capable of converting radiation into heat. The radiation-sensitive medium is aqueous-ineluable when coated and dried, and becomes hydrophobic under the action of heat. The polymer particles are made by polymerization of at least one hydrophobic monomer and at least one bonding compound in the presence of the hydrophilic polymer. The radiation-sensitive medium may be provided as a coatable composition to be applied to substrates to form a processless radiation-imageable lithographic printing precursor, which may further be provided with an aqueous eluable hydrophilic overcoat.

Abstract: A radiation-sensitive medium comprises hydrophilic polymer particles, the particles comprising a thermally softenable hydrophobic polymer, a hydrophilic polymer and a bonding compound capable of chemically bonding to the hydrophobic polymer and to the hydrophilic polymer. The radiation-sensitive medium further may comprise a substance capable of converting radiation into heat. The radiation-sensitive medium is aqueous-ineluable when coated and dried, and becomes hydrophobic under the action of heat. The polymer particles are made by polymerization of at least one hydrophobic monomer and at least one bonding compound in the presence of the hydrophilic polymer. The radiation-sensitive medium may be provided as a coatable composition to be applied to substrates to form a processless radiation-imageable lithographic printing precursor, which may further be provided with an aqueous eluable hydrophilic overcoat.

Abstract: A radiation-sensitive medium comprises hydrophilic polymer particles, the particles comprising a thermally softenable hydrophobic polymer, a hydrophilic polymer and a bonding compound capable of chemically bonding to the hydrophobic polymer and to the hydrophilic polymer. Th radiation-sensitive medium further may comprise a substance capable of converting radiation into heat. The radiation-sensitive medium is aqueous-ineluable when coated and dried, and becomes hydrophobic under the action of heat. The polymer particles are made by polymerization of at least one hydrophobic monomer and at least one bonding compound in the presence of the hydrophilic polymer. The radiation-sensitive medium may be provided as a coatable composition to be applied to substrates to form a processless radiation-imageable lithographic printing precursor.

Abstract: A positive-working radiation-sensitive composition for use with a radiation source comprises one or more polymers capable of being eluted in an alkaline aqueous solution and a development-enhancing compound. The invention provides a positive-working photosensitive composition of good sensitivity for use with one or both of ultra-violet radiation and an infrared laser radiation source. The composition is stable in its state before exposure and has an excellent handling property. The sensitivity of a radiation-sensitive coating based on the composition of this invention is increased without compromising the handling characteristics. Radiation-sensitive elements based on the composition of the invention have good development latitude. A positive-working lithographic printing precursor is based on the radiation-sensitive composition coated on a hydrophilic surface.

Abstract: A gravure printing element is fabricated using a negative-working thermally-imageable coating that is exposed using commercially available diode lasers, the coating being insensitive to ultraviolet light, daylight or visible light, and developable using aqueous media. A gravure etch mask is formed on a printing precursor by applying a coating of thermally-imageable material, curing the coating, imagewise illuminating the cured coating with a laser and removing with a developer the areas of the coating that were not illuminated. The masked precursor is then chemically etched to produce a gravure printing element.

Abstract: A radiation-sensitive medium comprises hydrophilic polymer particles, the particles comprising a thermally softenable hydrophobic polymer, a hydrophilic polymer and a bonding compound capable of chemically bonding to the hydrophobic polymer and to the hydrophilic polymer. Th radiation-sensitive medium further may comprise a substance capable of converting radiation into heat. The radiation-sensitive medium is aqueous-ineluable when coated and dried, and becomes hydrophobic under the action of heat. The polymer particles are made by polymerization of at least one hydrophobic monomer and at least one bonding compound in the presence of the hydrophilic polymer. The radiation-sensitive medium may be provided as a coatable composition to be applied to substrates to form a processless radiation-imageable lithographic printing precursor.

Abstract: An inkjet method is used to make an offset lithographic printing master by imagewise application of droplets of a coalescing agent on a layer of imageable medium comprising hydrophobic polymer particles, pre-coated on a hydrophilic lithographic base. Treatment with a developer removes those areas of the layer that have not been imagewise coalesced, thereby revealing the underlying hydrophilic base to create a lithographic printing master. The combination of imageable media and coalescing agent may be used in the fully on-press fabrication of a negative-working lithographic master, which may optionally also be made on a re-usable base.

Abstract: An inkjet method is used to make a negative working offset lithographic printing master by imagewise application of liquid inkjet droplets that form a mask on a layer of positive-working radiation imageable material pre-coated on a hydrophilic lithographic base. The masked layer is then subjected to a developer and developed. After development, only the masked areas of the positive working imageable material remain. Since this material is hydrophobic the resulting imaged layer on the hydrophilic lithographic base may be employed as a wet offset lithographic master. Since the image that is printed by the printing master coincides directly with the image printed by the inkjetting process on the imageable material, the method is inherently negative-working. By the method of the present invention positive-working radiation imageable media is therefore employed to make a negative-working printing master.

Abstract: A positive photosensitive composition for use with a radiation source comprises one or more polymers capable of being dissolved in an alkaline aqueous solution and a compound which, upon being heated, releases gas. The composition is stable in its state before exposure and has an excellent handling property. The sensitivity of a recording layer based on the composition of this invention is increased without compromising the handling characteristics. In addition radiation sensitive-elements based on the composition of the invention have good development latitude.

Abstract: A lithographic printing precursor for lithographic offset printing comprises a layer of imageable medium on a hydrophilic base. The imageable medium comprises hydrophobic polymer particles in an aqueous medium, a substance for converting light into heat, and a coalescence inhibitor. The coalescence inhibitor can comprise an inorganic salt, an organic base, an organic acid and a metal complex. The lithographic printing precursor may be used to make lithographic printing surfaces that obtain long run lengths on lower quality paper and in the presence of press-room chemicals. The lithographic printing precursor can be imaged and developed on-press and the imageable medium can also be sprayed onto a hydrophilic surface to create a printing surface that may be processed wholly on-press. It can also be processed in the more conventional fully off-press fashion.

Abstract: A lithographic printing precursor for lithographic offset printing comprises, a layer of imageable medium on a hydrophilic base. The imageable medium comprises hydrophobic polymer particles in an aqueous medium, a substance for converting light into heat, and a coalescence inhibitor. The lithographic printing precursor may be used to make lithographic printing surfaces that obtain long run lengths on lower quality paper and in the presence of press-room chemicals. The lithographic printing precursor can be imaged and developed on-press and the imageable medium can also be sprayed onto a hydrophilic surface to create a printing surface that may be processed wholly on-press. It can also be processed in the more conventional fully off-press fashion. The hydrophilic surface can be a printing plate substrate or the printing cylinder of a printing press or a sleeve around the printing cylinder of a printing press. The cylinder can be conventional or seamless.

Abstract: The invention provides a method for making a lithographic printing surface using media with coalescence inhibitor. The lithographic printing surface is made on a hydrophilic surface using a radiation sensitive medium that comprises hydrophobic polymer particles in an aqueous medium, a substance for converting light into heat, and a coalescence inhibitor. The lithographic printing surface made by the method of this invention may be used for printing long run lengths on lower quality paper and in the presence of press-room chemicals. The method allows for on-press imaging and development of the lithographic printing surface. The radiation sensitive medium can also be sprayed onto a hydrophilic surface to create a lithographic printing surface that may be processed wholly on-press. It can also be processed in the more conventional fully off-press fashion.

Abstract: A lithographic printing precursor for lithographic offset printing comprises, a layer of imageable medium on a hydrophilic base. The imageable medium comprises hydrophobic polymer particles in an aqueous medium, a substance for converting light into heat, and a non-crosslinkable aqueous-soluble composition. The lithographic printing precursor may be used to make lithographic printing surfaces that obtain long run lengths on lower quality paper and in the presence of press-room chemicals. The lithographic printing precursor can be imaged and developed on-press and the imageable medium can also be sprayed onto a hydrophilic surface to create a printing surface that may be processed wholly on-press. It can also be processed in the more conventional fully off-press fashion. The hydrophilic surface can be a printing plate substrate or the printing cylinder of a printing press or a sleeve around the printing cylinder of a printing press. The cylinder can be conventional or seamless.

Abstract: A gravure printing element is fabricated using a negative-working thermally-imageable coating that is exposed using commercially available diode lasers, the coating being insensitive to ultraviolet light, daylight or visible light, and developable using aqueous media. A gravure etch mask is formed on a printing precursor by applying a coating of thermally-imageable material, curing the coating, imagewise illuminating the cured coating with a laser and removing with a developer the areas of the coating that were not illuminated. The masked precursor is then chemically etched to produce a gravure printing element.

Abstract: Images are formed by the following process:(i) a substrate is treated with a layer of a liquid composition comprising(A) a residue that is polymerizable by means of free radicals, such as an acrylic ester,(B) a radiation-activated polymerization initiator for (A), such as a metallocene or a mixture of a Group IVA organometallic compound with a photoreducible dye.

Abstract: Photopolymerizable compositions for image recording, containing, among other components, addition-polymerizable, ethylenically unsaturated compounds and polymeric binders, wherein at least one of these binders is a copolymer of the formula (I) containing 5 to 50 percent by weight of one or more different structural units C1, C2, or combinations thereof containing carboxyl groups.

Abstract: A layer of a liquid composition containing (A) a compound containing at least one heat-polymerizable, ethylenically-unsaturated group, (B) a photopolymerizable material, and (C) a thermally-activated free radical initiator for polymerization of (A), is heated to solidify the layer, and subsequently it is exposed to actinic radiation in a predetermined pattern and those parts of the layer that have not become photopolymerized are removed by treatment with a suitable solvent.An example of an unsaturated, heat polymerizable compound (A) is butanediol dimethacrylate. An example of a photopolymerizable material (B) is an epoxidized novolak of 2,2-bis(4-hydroxyphenyl)propane with triphenylsulfonium hexafluorophosphate. A typical thermally-activated, free radical initiator (C) is cumene hydroperoxide.The process is suitable for the manufacture of printing plates and printed circuits.