W. R. Grace Co.-conn.

Polyfibron Technologies, Inc.

Macdermid Graphic Arts, Inc.

Ronald J Kumpfmiller

Truc-Chi T Huynh-Tran

Martin Lewis Carter

Cynthia Louise Ebner

David A Recchia

Srinivas K Mirle

Arthur L Berrier

Michael W Yang

William Krebs Goss

Jung H Tsao

Butadiene-polyether prepolymers which can be used in photopolymer resins are prepared by reacting butadiene homopolymer with a stoichiometric excess of isocyanate and then reacting the product with polyether diol. Thereafter the composition is reacted with hydroxyalkyl(meth)acrylate and alkyldialkanolamine. Flexographic printing plates may be prepared using photopolymer resin comprising butadiene-polyether prepolymers.

Aqueous developable photosensitive polyurethane-methacrylate

The present invention relates to methods for off-contact imaging solid relief printing plates and, in particular, to methods for imaging solid photocurable elements through a negative, where there is a gap between the solid photocurable element and the negative. The present invention also relates to printing plates produced by these methods.

Methods for off-contact imaging solid printing plates

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

A photopolymer useful in preparing water-developable, solid printing plates is prepared by preparing a urethane prepolymer by reacting polyoxyalkylene diols or polyester diols, or a mixture thereof, with an excess of diisocyanate, followed by chain extending the resulting prepolymer mixture with an alkyldialkanolamine, then reacting the chain-extended product with a hydroxyalkyl(meth)acrylate. The resulting photopolymer is suitably formulated with additional photoactive (meth)acrylate monomers or oligomers and photoinitiator for casting or extrusion on a substrate to form a flexographic printing plate. Following UV exposure of the plate through a negative, unexposed areas can be removed by washing with a slightly acidic aqueous medium, to give a plate with a desirable relief image. The use of the aqueous washout solution as opposed to organic solvents minimizes pollution problems.

Aqueous developable photosensitive polyurethane-(meth)acrylate

A method useful for stereolithography that yields enhanced photospeed, as well as a photocurable polymer composition well adapted for use with same, are disclosed. A preferred combination includes 1,2-dimethoxy-2-phenyl acetophenone, benzophenone, and triphenyl phosphine combined with a polyurethane (meth)acrylate oligomer.

Photosensitive compositions useful in three-dimensional part-building

An aqueous-developable article is made from a photoprepolymer made by reacting a maleated polyalkadienyl homo- or copolymer (e.g., polybutadiene) with an olefinically unsaturated compound capable of opening anhydride rings (e.g., hydroxyethyl methacrylate) with simultaneous chain extension using a polyalkadienyl polyol, followed by hydrolysis and neutralization with Li--, Na--, or K-containing base. When formulated with unsaturated monomers and photoinitiators, the photoprepolymer is particularly useful in making photopolymer-based flexographic printing plates.

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Marietta, GA, United States of America

Ronald J Kumpfmiller