Patent application number | Description | Published |
20080213700 | On-press development of high speed laser sensitive lithographic printing plates - A method of on-press developing a laser sensitive lithographic printing plate with ink and/or fountain solution is described. The printing member comprises on a substrate a photosensitive layer soluble or dispersible in ink and/or fountain solution and capable of hardening upon exposure to a laser. The plate is exposed with a laser and on-press developed with ink and/or fountain solution. The exposure and development are performed with the plate under lightings that contain no or substantially no radiation below a wavelength selected from 400 to 650 nm, or in the dark or substantially dark. | 09-04-2008 |
20080241767 | Deactivating device and method for lithographic printing plate - A device as well as method for deactivating without developing an exposed lithographic printing plate is disclosed. The device comprises a structure for providing a deactivating agent that is capable of deactivating without developing the plate. The plate comprises on a substrate a photosensitive layer capable of hardening upon exposure to a radiation, and becoming incapable of or having reduced rate of hardening after contacting with a deactivating agent. The deactivated plate is safe or has better stability at room lighting, and can be handled under room lighting before and during development. The development can be on press with ink and/or fountain solution or off press with a liquid developer. | 10-02-2008 |
20080271627 | Lithographic printing press and method for on-press imaging laser sensitive lithographic plate - A lithographic printing press having a plate cylinder in a covered compartment suitable for on-press imaging and developing a laser sensitive plate is described. The plate cylinder as well as certain other press parts is covered by non-transparent and/or safe-light-passing-only covers so that no or only limited amount of unsafe light passes onto the plate mounted on the plate cylinder during on-press imaging and development. The plate comprises on a substrate a photosensitive layer soluble or dispersible in ink and/or fountain solution and capable of hardening upon exposure to a laser having a wavelength selected from 200 to 1200 nm. The plate is on-press exposed with the laser, developed with ink and/or fountain solution, and then directly prints inked images to the receiving sheets. | 11-06-2008 |
20080274429 | Aqueous treatment of on-press developable lithographic printing plate - A method of treating an on-press developable lithographic printing plate with an aqueous treating solution after imagewise exposure and before on-press development is described. The plate comprises on a substrate a photosensitive layer developable with ink and/or fountain solution and capable of hardening upon exposure to a radiation. The plate is imagewise exposed with a radiation, overall treated with a treating solution to cause at least one chemical or physical change in the photosensitive layer or on the substrate surface, and then on-press developed with ink and/or fountain solution. Such a treatment allows improvement on the performance of the imagewise exposed plate by, for example, improving the white light stability, forming visible imaging, increasing the hydrophilicity of the substrate, or increasing the developability of the photosensitive layer. | 11-06-2008 |
20080280233 | Method for deactivating on-press developable lithographic printing plate - A method of deactivating an on-press ink and/or fountain solution developable lithographic printing plate is described. The printing member comprises on a substrate a photosensitive layer soluble or dispersible in ink and/or fountain solution and capable of hardening upon exposure to a laser. The plate is exposed with a laser, deactivated, and then on-press developed with ink and/or fountain solution. The deactivation is carried out by overall applying to the plate a deactivating agent, heat, or a radiation that has different wavelength from the laser and does not cause hardening of the photosensitive layer. The deactivation allows the plate to be handled on press under white light or other light that is unsafe for a non-deactivated plate. | 11-13-2008 |
20080280234 | Method of forming visible image for on-press developable lithographic printing plate - A method of forming visible image on an on-press developable lithographic printing plate is described. The plate comprises on a substrate a photosensitive layer developable with ink and/or fountain solution and capable of hardening upon exposure to a radiation. The plate is imagewise exposed with a radiation, overall treated with a discoloring agent to form visible image or enhanced visible image, and then on-press developed with ink and/or fountain solution. The formation of visible image allows easy identification or inspection of the plate by the pressman before mounting on press. | 11-13-2008 |
20090025591 | Process for on-press developing overcoat-free lithographic printing plate - A method of processing an overcoat-free on-press developable lithographic printing plate with ink and/or fountain solution is described. The plate comprises on a substrate a photosensitive layer which is either capable of hardening (negative-working) or solubilization (positive-working) upon exposure to a laser, the non-hardened or solubilized areas of the photosensitive layer being soluble or dispersible in ink and/or fountain solution. The plate is exposed with a laser, heated to an elevated temperature, and then developed with ink and/or fountain solution on a lithographic press. The laser exposed plate is preferably heated by passing through a heating device or while mounted on a lithographic press before on-press development. | 01-29-2009 |
20090061363 | Method for on-press developing laser sensitive lithographic printing plate - A method of on-press developing a high-speed laser sensitive lithographic printing plate with ink and/or fountain solution is described. The plate comprises on a substrate a photosensitive layer soluble or dispersible in ink and/or fountain solution and capable of hardening upon exposure to a laser. The plate is exposed with a laser and on-press developed with ink and/or fountain solution. At least a portion of the on-press development is performed with the plate under a yellow-red light, in substantial darkness, or under a light that is different from the light for printing and does not cause hardening of the photosensitive layer during on-press development. | 03-05-2009 |
20090061364 | Process for on-press developable lithographic printing plate involving preheat - A method of processing an on-press developable lithographic printing plate with ink and/or fountain solution is described. The plate comprises on a substrate a photosensitive layer which is either capable of hardening (negative-working) or solubilization (positive-working) upon exposure to a laser, the non-hardened or solubilized areas of the photosensitive layer being soluble or dispersible in ink and/or fountain solution. The plate is exposed with a laser, heated to an elevated temperature, and then developed with ink and/or fountain solution on a lithographic press. The laser exposed plate is preferably heated by passing through a heating device or while mounted on a lithographic press before on-press development. | 03-05-2009 |
20090130596 | Lithographic printing plate comprising alkaline soluble and alkaline insoluble polymeric binders - Negative lithographic printing plate having on a substrate a photosensitive layer comprising an alkaline soluble polymeric binder, an alkaline insoluble polymeric binder, a polymerizable monomer, and an initiator is described. The photosensitive layer is imagewise exposed with a radiation to cause hardening in the exposed areas, and then developed to remove the non-hardened areas. The combination of both alkaline soluble polymeric binder and alkaline insoluble polymeric hinder in a photosensitive layer can give excellent combined durability, developability, and coatability. | 05-21-2009 |
20090170040 | Treatment of laser exposed lithographic printing plate before development - A method of treating a laser exposed lithographic printing plate with a deactivating solution followed by overall irradiation is described. The plate comprises on a substrate a photosensitive layer capable of photo hardening. The deactivating solution is capable of deactivating the photo hardening capability of the photosensitive layer in the non-hardened areas so that the overall irradiation does not cause hardening of the photosensitive layer in the non-hardened areas. The deactivation and overall irradiation cause one or more chemical or physical changes to the photosensitive layer, such as further hardening of the imaged areas, improved contrast, improved developability, or improved substrate hydrophilicity. The overall irradiated plate is further developed on press with ink and/or fountain solution or off press with a developer. For off-press development, the developer may be used as the deactivating solution. | 07-02-2009 |
20090197207 | Negative laser sensitive lithographic printing plate having specific photosensitive composition - High speed violet or ultraviolet laser sensitive lithographic printing plate comprising on a hydrophilic substrate a specific photosensitive composition is described. The photosensitive layer comprises an alkaline soluble polymeric binder, a multifunctional (meth)acrylate monomer, a free-radical initiator, and a sensitizing dye. The plate is imagewise exposed with a violet or ultraviolet laser at a dosage of less than 300 μJ/cm | 08-06-2009 |
20090208874 | Method of processing on-press developable lithographic printing plate having overcoat - A method of processing an on-press developable lithographic printing plate involving the removal of the overcoat after laser imaging and before on-press development is described. The plate comprises a substrate, an on-press ink and/or fountain solution developable photosensitive layer, and an overcoat. The laser imaged plate is mechanically stripped off the overcoat, and then developed with ink and/or fountain solution on a lithographic press. Such a process allows the use of overcoat to achieve faster photospeed and improved durability of the plate without having various issues as related to overcoat such as contamination to the fountain solution, difficulty to remove of certain overcoat, and limited white light stability. | 08-20-2009 |
20090220891 | Method of on-press developing overcoated lithographic printing plate - A method of processing an on-press developable lithographic printing plate involving the removal of overcoat after imagewise exposure and before on-press development is described. The plate comprises a substrate, an on-press ink and/or fountain solution developable photosensitive layer, and an overcoat. The laser imaged plate is stripped off the overcoat, and then under a white room light mounted on press and developed with ink and/or fountain solution. Here the plate is capable of hardening upon exposure to a laser, has limited white light stability before the removal of the overcoat, and has significantly improved white light stability after the removal of the overcoat. | 09-03-2009 |
20090246697 | Method of processing overcoated lithographic printing plate - A method of processing an on-press developable lithographic printing plate involves the removal of overcoat by brushing or rubbing while in contact with water or an aqueous solution after imagewise exposure and before on-press development. The plate comprises a substrate, an on-press ink and/or fountain solution developable photosensitive layer, and a water soluble or dispersible overcoat. Preferably, the overcoat is incapable of being completely removed with ink and/or fountain solution on a lithographic press during roll up. Such a method allows the use of more durable overcoat for on-press developable plate. | 10-01-2009 |
20090290140 | Deactivating device and method for lithographic plate - A device as well as method for deactivating without developing an exposed lithographic printing plate is disclosed. The device comprises a structure for providing a deactivating agent that is capable of deactivating without developing the plate. The plate comprises on a substrate a photosensitive layer capable of hardening upon exposure to a radiation, and becoming incapable of or having reduced rate of hardening after contacting with a deactivating agent. The deactivated plate is safe or has better stability at room lighting, and can be handled under room lighting before and during development. The development can be on press with ink and/or fountain solution or off press with a liquid developer. | 11-26-2009 |
20090291396 | Process for on-press developing high speed laser sensitive lithographic printing plate - A method of on-press developing a high-speed laser sensitive lithographic printing plate with ink and/or fountain solution is described. The printing member comprises on a substrate a photosensitive layer soluble or dispersible in ink and/or fountain solution and capable of hardening upon exposure to a laser. The plate is exposed with a laser and on-press developed with ink and/or fountain solution. At least a portion of the on-press development is performed with the plate under a yellow-red light or in substantial darkness, and at least a portion of the lithographic printing is performed under white light. | 11-26-2009 |
20090297984 | Method for on-press developing high speed laser sensitive lithographic plate - A method of on-press developing a high-speed laser sensitive lithographic printing plate with ink and/or fountain solution is described. The printing member comprises on a substrate a photosensitive layer soluble or dispersible in ink and/or fountain solution and capable of hardening upon exposure to a laser. The plate is exposed with a laser and on-press developed with ink and/or fountain solution. At least a portion of the on-press development is performed with the plate under a yellow-red light or in substantial darkness. | 12-03-2009 |
20100055614 | Lithographic printing plate having specific polymeric binders - Negative lithographic printing plate having on a substrate a photosensitive layer comprising an alkaline soluble polymeric binder, an alkaline insoluble polymeric binder, a polymerizable monomer, and an initiator is described. The photosensitive layer is imagewise exposed with a radiation to cause hardening in the exposed areas, and then developed to remove the non-hardened areas. The combination of both alkaline soluble polymeric binder and alkaline insoluble polymeric binder in a photosensitive layer can give excellent combined durability, developability, and coatability. | 03-04-2010 |
20100147173 | On-press development of lithographic plate utilizing plate holder for exposed plate - A method of on-press developing a lithographic printing plate with ink and/or fountain solution involving the utilization of a plate holder for transferring the exposed plate from the imager to the lithographic press is described. The plate comprises on a substrate a photosensitive layer capable of hardening or solubilization upon exposure to a laser, and the non-hardened or solubilized areas of the photosensitive layer are soluble or dispersible in ink and/or fountain solution. The plate is exposed with the laser on an imager and placed in a plate holder to transfer to the press for development with ink and/or fountain solution and lithographic printing. The plate holder is preferably light-tight so that the plate in the plate holder is shielded from the room light. | 06-17-2010 |
20100216074 | Method for on-press developable lithographic plate utilizing light-blocking material - A method for applying a light-blocking material onto an imagewise exposed lithographic printing plate is disclosed. The exposed plate comprises on a substrate a photosensitive layer having hardened areas and non-hardened areas (for negative plate) or solubilized areas and non-solubilized areas (for positive plate). The non-hardened or solubilized areas of said photosensitive layer are removable with ink and/or fountain solution on a lithographic press. The light-blocking material is applied to the plate preferably from a solution or dispersion containing such material. The application of the light-blocking material prevents at least a portion of the room light in a certain wavelength (such as ultraviolet) range from reaching the photosensitive layer, thus allowing improved room light stability of the exposed plate. | 08-26-2010 |