摘要:
A lithographic printing plate for use on a printing press, with minimal or no additional processing after exposure to actinic radiation, comprises a printing plate substrate, a polymeric resist layer capable of imagewise photodegradation or photohardening, and a plurality of microencapsulated developers capable of blanket-wise promoting the washing out of either exposed or unexposed areas of the polymeric resist. The microencapsulated developers may be integrated into the polymeric resist layer, or may form a separate layer deposited atop the polymeric resist layer, or may be coated onto a separate sheet support capable of being brought into face-to-face contact with conventional printing plates.
摘要:
A lithographic printing plate precursor for use on a printing press, with minimal or no additional processing after exposure to actinic radiation, comprises a printing plate substrate, a polymeric resist layer capable of imagewise photodegradation or photohardening, and a plurality of microencapsulated developers capable of blanket-wise promoting the washing out of either exposed or unexposed areas of the polymeric resist. The microencapsulated developers may be integrated into the polymeric resist layer, or may form a separate layer deposited atop the polymeric resist layer, or may be coated onto a separate sheet support capable of being brought into face-to-face contact with conventional printing plates.
摘要:
The present invention discloses the use of rubber and surfactant to enhance the durability and resolution of on-press developable lithographic printing plates. The rubber is preferably incorporated into a photoresist as discrete particulate rubber. To ensure a uniform and stable dispersion, the rubber is suspended in the photoresist by means of a surfactant having an HLB approximately between 7.0 and 18.0.
摘要:
The present invention discloses the use of rubber and surfactant to enhance the durability and resolution of on-press developable lithographic printing plates. The rubber is preferably incorporated into a photoresist as discrete particulate rubber. To ensure a uniform and stable dispersion, the rubber is suspended in the photoresist by means of a surfactant having an HLB approximately between 7.0 and 18.0.
摘要:
The present invention provides a method for developing a lithographic plate on a printing press without the requirement of bath processing, the printing press equipped with means for delivering ink and aqueous fountain solutions to the plate, the preferred plate having in order (a) a substrate; and (b) a photoresist photohardenable upon imagewise exposure to actinic radiation, the photoresist comprising (i) a macromolecular organic binder; (ii) a photopolymerizable ethylenically unsaturated monomer having at least one terminal ethylenic group capable of forming a high polymer by chain-propagated polymerization, (iii) a polymerization initiator activatable by actinic radiation, and (iv) a disperse hydrophilic microgel. According to a product aspect, the present invention also provides a lithographic plate, configured as indicated, with the further combination therewith of an on-press removable polymeric overcoat.
摘要:
The present invention sets forth the incorporation of a substituted 2-phenyl-4,6-bis (trichloromethyl)-1,3,5-triazine in photoresists of lithographic printing plates for the purpose of promoting their shelf-life, room light stability, and developability. The present invention provides a photocurable composition comprising at least a photopolymerizable ethylenically unsaturated monomer having at least one terminal ethylenic group and capable of forming a polymer upon exposure to actinic radiation; and an s-triazine capable of initiating free radical polymerization of the photopolymerizable ethylenically unsaturated monomer and being represented by the following general formula [I]: ##STR1## wherein R.sub.1 is either OR.sub.4 or NR.sub.5 R.sub.6, wherein R.sub.5 and R.sub.6 may or may not be identical with each other, either R.sub.5 or R.sub.6 may represent hydrogen, and wherein R.sub.4 and at least one of R.sub.5 and R.sub.6 represent a ballast group capable of preventing the substantial volatilization of the s-triazine from the photoresist composition, the ballast group being a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group, the substituted or unsubstituted alkyl group having at least 4 carbon atoms, the substituted or unsubstituted aryl group having at least 6 carbon atoms; R.sub.2 and R.sub.3 may or may not be identical with each other and each represent hydrogen, halogen, phenyl, a substituted or unsubstituted alkyl group, or an alkoxyl group; X and Y may or may not be identical with each other and each represent chlorine or bromine; and m and n may or may not be identical with each other and are each an integer of 0, 1, or 2. Desirable compositions will further comprise at least one photooxidizable leuco triarylmethane dye.
摘要:
The present invention is directed to a method for the on-press development and printing of images. The method generally comprises the steps of providing a lithographic printing plate precursor element comprising a lithographic hydrophilic printing plate substrate, a photohardenable photoresist, and a layer of polymeric protective overcoat; imagewise exposing the precursor element to actinic radiation through said photoresist and overcoat layer sufficiently to photoharden the photoresist in exposed regions and provide a latent image in said photoresist layer; placing the precursor element onto a lithographic printing press; and running the press, whereby printing fluid effects removal of the overcoat and development of said latent image. In particular modes of practices, the method utilizes an overcoat having incorporated therein a water or fountain soluble or dispersible crystalline compound. The overcoat can 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.
摘要:
Described is the use of a plasticizing-permeation enhancing additive in negative-working, on-press developable lithographic printing plates. Briefly, a plasticizer, which is dispersible or soluble in press fountain and ink solutions and soluble in acrylic monomers and oligomers, are incorporated into a plate's photoresist at concentrations sufficient to enhance said resist's permeability to or diffusion by press solutions. Such additives make the photoresist more permeable to fountain solution prior to crosslinking, while being easily extracted with ink and fountain solution after crosslinking. In certain embodiments, a surfactant is added to facilitate the dispersion of hydrophobic remnants of removed resist material in the fountain solution, and thereby reduce scumming. Lithium salts may also be incorporated into the photoresist to disrupt hydrogen bonding of, for example, urethane acrylate polymers which tend to associate by hydrogen bonding.
摘要:
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.
摘要:
An embodiment of the invention provides a focus adjustable apparatus adapted to be disposed on a transparent substrate to modulate a plurality of rays passing through the transparent substrate. The focus adjustable apparatus includes a light modulation device, an eye tracking device, an eyesight status device and a controller. The light modulation device receives the rays from the transparent substrate and adjusts an emergent angle of each ray. The eye tracking device tracks a position of a user and estimates a distance between the user and the focus adjustable apparatus. The eyesight status device obtains an eyesight data of the user. The controller provides a control signal to drive the light modulation device by estimating the emergent angle of the each ray according to the distance between the user and the focus adjustable apparatus and the eyesight data of the user.