E.i. Dupont De Nemours and Company

Other

Robert W Ashcraft

Robert B Ayrest

John H Bayless, Jr

Jon Gregory Moehlmann

Rusty E Koenigkramer

Gary K Stout

An apparatus for heating of thermally deformable sheet material includes a frame consisting of a pair of end beams extending laterally and a pair of side rails secured longitudinally between the end beams in a rectangular arrangement The side rail channels are oriented with their longitudinal openings extending upwardly. A heating tray assembly extends laterally and includes a pair of quick-release cam clamps disposed at opposed ends thereof to engage the respective side rail in a slidable, releasable fashion, so that the tray may be installed/removed at any location and clamped at that location. A sheet support assembly includes similar cam clamps at each end, and may be installed/removed at any location and translated/clamped at that location to maintain planar support of a workpiece.

Thermoplastic sheet heating appliance

A process is disclosed for applying a preformed photopolymerizable solder mask film and a photosensitive liquid to a printed circuit substrate containing a plurality of holes wherein reduced failure is obtained in photopolymerized areas of the solder mask film above the holes as determined after a soldering operation. The photosensitive liquid contains at least one ethylenically unsaturated compound capable of forming a high polymer by addition polymerization and a first photoinitiator system which has an absorption maximum in a first spectral region. The preformed photopolymerizable film contains at least one ethylenically unsaturated compound capable of forming a high polymer by addition polymerization and a second photoinitiator system, such that the preformed photopolymerizable film has an absorption maximum in a second spectral region and is activated by actinic radiation therein and has an absorption minimum in the first spectral region and transmits actinic radiation therein.

Lamination of a photopolymerizable solder mask layer to a substate

An element suitable for preparing transparencies using an electrostatic plain paper copier is described. This element comprises a polyethylene terephthalate support (polyester), at least one subbing layer coated thereon and coated to the subbing layer a toner receptive layer comprising a mixture of an acrylate binder, a polymeric antistatic agent having carboxylic acid groups, a cross-linking agent, butylmethacrylate modified polymethacrylate beads and submicron polyethylene beads. These elements produce excellent transparencies.

Polyester support for preparing electrostatic transparencies

Use of a photoresist is improved due to increased adhesive to a substrate through an additive in the resist of a condensation polymer of formaldehyde, toluene sulfonamide and either a triazine such as melamine or hydantoin.

Adhesion promotion in photoresist lamination and processing

Process for preparing a positive overlay using an imagewise exposed peel apart photosensitive element comprising a strippable cover sheet, photoadherent layer containing a colorant, a tacky, nonphotosensitive contiguous layer, and a support wherein after peeling apart the element bearing the contiguous layer and complementary colored unexposed areas is adhered to a transparent receptor, and the transparent and colored unexposed image adhered thereto are removed. By repeating the procedure with peel apart elements of different color and overlaying the images in register colored proofs are prepared.

Process for preparing a positive overlay

In preparing an opaque backing layer for a photographic film, superior covering power and coating dispersion stability are obtained by (1) dispersing carbon black in a minor phase of polyvinyl pyrrolidone/vinyl acetate copolymer before addition of a major phase of polyvinyl alcohol, and (2) delaying the addition of surfactant or coating aids until after complete mixing of the polyvinyl alcohol with the solid carbon black dispersion. This coating dispersion is particularly useful for the preparation of a dischargeable opaque backing layer for a diffusion transfer film element.

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Towanda, PA, United States of America

Robert W Ashcraft