A method for producing flexographic printing plates, using as starting material a photopolymerizable flexographic printing element which at least comprises, arranged one atop another, a dimensionally stable support, and at least one photopolymerizable, relief-forming layer, at least comprising an elastomeric binding, an ethylenically unsaturated compound, and a photoinitiator, a digitally imagable layer, and the method comprises at least the following steps (a) producing a mask by imaging the digitally imagable layer, (b) exposing the photopolymerizable, relief-forming layer through the mask with actinic light, and photopolymerizing the image regions of the layer, and (c) developing the photopolymerized layer by washing out the unphotopolymerized regions of the relief-forming layer with an organic solvent, or by thermal development, characterized in that step (b) comprises two or more exposure cycles (b 1) to (b n) with actinic light with an intensity of 100 to 5000 mW/cm.sup.2 from a plurality of UV-LEDs, the energy input into the photopolymerizable, relief-forming layer per exposure cycle being 0.1 to 5 J/cm.sup.2.

A resist underlayer film composition for use in a multilayer resist method, containing one or more compounds shown by formula (1), and an organic solvent,

WX).sub.n   (1)

W represents an n-valent organic group having 2 to 50 carbon atoms. X represents a monovalent organic group shown by formula (1X). “n” represents an integer of 1 to 10,

##STR00001##

The dotted line represents a bonding arm. R.sup.01 represents an acryloyl or methacryloyl group. Y represents a single bond or a carbonyl group. Z represents a monovalent organic group having 1 to 30 carbon atoms. A resist underlayer film composition can be cured by high energy beam irradiation and form a resist underlayer film having excellent filling and planarizing properties and appropriate etching resistance and optical characteristics in a fine patterning process by a multilayer resist method in the semiconductor apparatus manufacturing process.

The invention pertains to a photosensitive element, particularly a photopolymerizable printing form precursor; a method of preparing the photosensitive element to form a printing form for use in relief printing; and, a process of making the photosensitive element. The printing form precursor includes a layer of a photosensitive composition, a digital layer that is adjacent to a side of the photosensitive layer, and a cell pattern layer that is disposed between the photosensitive layer and the digital layer. The cell pattern layer includes a plurality of features in which each feature an area between 5 to 750 square microns and is composed of an ink that is opaque to actinic radiation and transparent to infrared radiation. Since the cell pattern layer is integral with the printing form precursor, digital imaging can occur rapidly with relatively low resolution optics to form a mask without needing to also form a microcell pattern of the digital layer. The printing form precursor having the integrated cell pattern layer facilitates the preparation of relief printing forms to have a print surface suitable for printing solids with uniform, dense coverage of ink.

A finished flexo plate with printing dots and non-printing indicia. The printing dots have an elevation above the plate floor sufficient to transfer ink to a substrate in a printing step, whereas the non-printing indicia are configured for persistent readability relative to the plate floor but have a height relative to the plate floor insufficient to transfer ink to the substrate in the printing step. The non-printing indicia define a pattern of alphanumeric characters, non-text graphics, or a combination thereof, and are disposed on the plate floor in the form of areas of presence and absence of polymer defined by structures formed of microdots, each microdot having an elevation relative to the plate floor lower than a printing height.

A resist composition comprising a polymer is provided, the polymer comprising repeat units derived from a sulfonium or iodonium salt having a nitro-substituted benzene ring in a linker between a polymerizable unsaturated bond and a fluorosulfonic acid site. The resist composition has a high sensitivity and forms a pattern with improved LWR or CDU, independent of whether it is of positive or negative tone.

A mask element for flexographic printing can include: a substrate; a polymeric layer on the substrate and having a first infrared absorbing material; a non-silver halide thermally-ablatable imaging layer on the polymeric layer and having a second infrared absorbing material and an ultraviolet absorbing material in an thermally-ablatable polymeric binder; and a particulate-treated protective topcoat on the non-silver halide thermally-ablatable imaging layer and having a thermally-ablatable polymer containing inorganic particles of from about 0.25% to about 20% by dry weight of the particulate-treated protective topcoat. The inorganic particles include silicon dioxide or metal dioxide or combinations thereof. The inorganic particles can be thermally-ablatable particles, such as iron oxide, or be not thermally ablatable particles, such as silica, titanium dioxide, zinc oxide, or combinations thereof. the inorganic particles are present from about 0.5% to 10%. The inorganic particles have a size range from 0.05 microns to 1 micron.

Post exposure bake methods are provided. In one example, a method includes placing a workpiece having a photoresist layer on a workpiece support disposed in a processing chamber. The method includes exposing the photoresist to photons of a wavelength through a photomask. The method includes performing a post exposure bake heating process on the workpiece with the photoresist heating layer. The post exposure bake heating process can include heating the workpiece with both a radiant heat source and a second heat source disposed in the workpiece support until a temperature of the workpiece reaches a post exposure bake setpoint temperature.

An ablation layer for a photosensitive resin for a relief printing plate, the ablation layer containing at least an acid-modified polymer and an infrared-absorbing agent and having a layer acid value as defined below of 2 mg KOH/g or more and 400 mg KOH/g or less, and a neutralized salt ratio as defined below of 0.9 or less, wherein the Layer acid value=(Acid value of the acid-modified polymer)×(Mass ratio of the acid-modified polymer to an entire ablation layer); and wherein the Neutralized salt ratio=(Number of moles of polymer wherein acid in the acid-modified polymer exists in neutralized salt state)/(Total number of moles of the acid-modified polymer).

An ablation layer for a photosensitive resin for a relief printing plate, the ablation layer containing at least an acid-modified polymer and an infrared-absorbing agent and having a layer acid value as defined below of 2 mg KOH/g or more and 400 mg KOH/g or less, and a neutralized salt ratio as defined below of 0.9 or less, wherein the Layer acid value=(Acid value of the acid-modified polymer)×(Mass ratio of the acid-modified polymer to an entire ablation layer); and wherein the Neutralized salt ratio=(Number of moles of polymer wherein acid in the acid-modified polymer exists in neutralized salt state)/(Total number of moles of the acid-modified polymer).

Flexographic printing members amenable to aqueous (or organic) development do not exhibit the deleterious effects on printing performance characteristic of some conventional alternatives. Embodiments of the invention utilize a photopolymerizable layer comprising, consisting of, or consisting essentially of a photopolymerization initiator and a water-dilutable (but not water-soluble) monomer.