E.i. Dupont De Nemours and Company

Dximaging

Catharine E Looney

Steven P Schmidt

Alan Robert Craig

William A Frey

Michael A Luddy

Alan S Dubin

Charles C Leflar

Graciela Beatriz Blanchet-Fincher

Edward Blair Caruthers

Rolf Dessauer

Curtis R Fincher

Michael L Levin

Dana S Smith

Lawrence K-f Cheung

Process for reversal development of a latent electrostatic image in a layer on a conductive support by developing with an electrostatic developer having electrostatically charged toner particles by

Reversal development of latent electrostatic images on xeroprinting

Process for preparation of high resolution image exposing imagewise a photopolymerizable element having a removable cover sheet and a conductive support or a temporary support which is replaced by a conductive support, stripping the cover sheet and laminating the imagewise exposed photopolymerizable layer to a second exposed photopolymerizable layer on a temporary support, removing the temporary support, charging electrostatically the exposed photopolymerizable layers, developing, e.g., liquid electrostatic developer or dry toner developer, and optionally transferring the developed image to a receptor surface, e.g., paper. The process is useful in preparing multiple copies in more than one version, e.g., logos, headlines, corrections, etc.

High resolution superimposed images from photopolymer electrographic

Process for preparation of a correct reading image comprising

Correct-reading images from photopolymer electrographic master

Photohardenable electrostatic master comprising an electrically conductive substrate, e.g., aluminized polyethylene terephthalate, bearing a layer of a photopolymer comprising an organic polymeric binder, compound having at least one ethylenically unsaturated group, photoinitiator, an aromatic amino compound, as defined, and an acid, e.g., p-toluene sulfonic acid, or an oxidized substituted aromatic amino compound. The photohardenable electrostatic master having improved charge decay and backtransfer is used for electrostatic proofing, etc.

Photohardenable electrostatic master having improved backtransfer and

Novel particle reagents for light scattering immunoassays are provided. The particle reagents are high refractive index shell-core polymers covalently bonded to compounds of biological interest or analogs thereof. A method of measuring unknown concentrations of these compounds of biological interest by measuring changes in turbidity caused by particle agglutination or its inhibition is also provided.

Covalently bonded high refractive index particle reagents and their use

Novel particle reagent for light scattering immunoassays are provided. The particle reagents are high refractive index shell-core polymers covalently bonded to compounds of biological interest. A method of measuring unknown concentrations of these compounds of biological interest by measuring changes in turbidity caused by particle agglutination or its inhibition is also provided.

Flexible filters capable of transmitting radiation in the spectral range of 315 to 380 nm and absorbing radiation in the spectral range of 400 to 550 nm consist essentially of a thin flexible film, e.g., polyethylene terephthalate containing or having coated thereon a dye in a concentration of 15 to 60 mg/dm.sup.2 and optionally, as a component of the coating, a thermoplastic organic binder, e.g., cellulose acetate butyrate, present in the coating with the dye, said dye being of the formula: ##STR1## where R.sub.1 is lower alkyl of 1 to 5 carbon atoms; R.sub.2 and R.sub.3, which may be the same or different, are selected from the group consisting of R.sub.1, 2-cyanoethyl, 2-hydroxyethyl and ##STR2## or form a saturated 5- or 6- membered ring; R.sub.4 is taken from the class consisting of lower alkyl of 1 to 5 carbon atoms, aryl or alkaryl of 6 to 9 carbon atoms, and aralkyl. The filters are useful in exposing dual response photosensitive materials with ultraviolet radiation sources which contain appreciable quantities of visible radiation.

Flexible ultraviolet radiation transmitting filters

Dry leather is dyed with azoic dyes without wetting the leather with water by incorporating into the leather the required diazonium component and any required coupling component in a substantially non-aqueous volatile low-viscosity solvent and incorporating into the leather any other materials required for the coupling reaction in such a solvent or as a vapor. The coupling component can be a natural or synthetic phenolic tanning agent employed in tanning the leather. Dye patterns can be applied to the surface of the leather by using a light-sensitive diazonium component and photo-imaging the surface before effecting coupling. Dry leather is dyed by such processes without significant change in properties.

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Wilmington, DE, United States of America

Catharine E Looney