W. R. Grace Co.

Polyfibron Technologies, Inc.

W. R. Grace Co.-conn.

Michael W Yang

Paul R Hein

Rustom Sam Kanga

Arthur D Ketley

Ronald J Kumpfmiller

Alvin Varnard Randall

Martin Lewis Carter

Robert A Irvin

William Krebs Goss

William K Goss

James A Evans

Roland L Orem

Steven E Bauer

Jung H Tsao

Multilayer printing plates having layers with differing moduli are made by exposing through a photographic negative a plurality of layers comprising a solid photocurable cap and al least one liquid photocurable layer.

Solid-capped liquid photopolymer printing elements

Laser-imageable flexographic printing plates and a method of making same are disclosed. A thin polymeric film doped with a UV absorber is laminated to a photopolymer layer. The film is ablated from the photopolymer using a laser operating at a selected wavelength to create an in situ negative. The resulting negative can be subjected to typical UV flood exposure and development.

Method of making laser imaged printing plates utilizing ultraviolet

Photocurable elements which are useful for preparing flexographic printing plates are provided which comprise a printing layer and a contiguous base layer, the printing layer comprising about 40 to 95 parts by weight of an elastomeric block copolymer, about 5 to 60 parts by weight of a second elastomeric polymer which is incompatible with the block copolymer, a photopolymerizable monomer, and a photoinitiator. The printing layer preferably also comprises an actinic radiation scattering and absorbing pigment. Also provided are relief printing plates prepared from the photocurable elements. The printing plates have a tack-free surface having excellent ink transfer properties, abrasion resistance, and solvent resistance. A high level of exposure latitude may also be provided in the photocurable elements of the invention.

Photocurable elements having two photocurable layers

A relief producing laminate having an over-lamina comprised of an unsaturated natural-like rubber composition characterized by relief differentiation in response to patterned radiation exposure and an under-lamina comprised of a resilient composition and adhered to the over-lamina. The term 'natural-like rubber' as used herein includes both natural and synthetic rubbers which exhibit creep as a result of stress relaxation after being cast or formed. The over-lamina is preferably a butadiene homopolymer or copolymer resin composition, more preferably a halogenated butadiene composition and most preferably a neoprene composition. The composition preferably includes a thiol, a monomer and a photoinitiator. The under-lamina composition may be a woven textile or a polymer and is preferably a monoalkenyl aromatic-diene block copolymer resin composition. It is preferably radiation cured and preferably includes a monomer and a photoinitiator. The under-lamina preferably comprises at least three juxtaposed layers, each layer being less highly cured than the juxtaposed under-layer and the over-lamina preferably comprises at least three juxtaposed layers with at least the layer closest to the under-lamina being more highly cured than the over-layers. The invention also includes the stabilized plastic printing plate produced from the laminate and the method of radiation curing the laminate to produce the printing plate.

Radiation responsive relief imageable plastic laminate

Curable composition characterizing by its containing (1) 10 to 97% by weight of a material chosen from the group consisting of C--C unsaturated polymers exemplified by monoalkenyl aromatic diene copolymers, halogen substituted butadienes, acrylonitriles and acrylurethanes and C--C saturated polymeric binders such as the polyvinylpyrolidones, cellulose acetate butyrates and cellulose acetate succinates; (2) at least 1% by weight of material (1) of at least one monomer substantially compatible with material (1) and having at least one cross-linkable C--C double bond; (3) 0.1 to 35% by weight of material (1) of thiol exemplified by polythiols; and optionally (4) a curing agent. The disclosure is directed primarily at printing plate production with a composition containing 0.01 to 10% by weight of material (1) of a photoinitiator and a monomer that is an addition photopolymerizable ethylenically unsaturated acrylic or methacrylic acid ester containing two or more acrylate or methacrylate groups per molecule or mixtures thereof. In an alternate form low molecular weight liquid rubber polymer may be included in the composition. Other materials such as stabilizers may also be present.

Polythiol effect curable polymeric composition

This invention relates to a liquid radiation curable composition useful for coating and imaging which comprises (1) an acrylic or methacrylic terminated, urethane containing polyene, (2) a non-water soluble vinyl monomer diluent, preferably an acrylate or methacrylate monomer diluent, (3) a polythiol containing at least two thiol groups per molecule and (4) a photoinitiator. The composition on exposure to radiation, e.g., a U.V. light source, cures to a solid polythioether.

Growing community of inventors

Marietta, GA, United States of America

Michael W Yang