Oce-van Der Grinten N.v.

Oce-nederland B.v.

Oce-van De Grinten N.v.

Gerardus J Crommentuyn

Adrianus M Hectors

Marcel L Pennings

Johannes H Kuiper

Wilhelmus H Albrink

Johanna L Kortenoeven-van Den Beuken

Rudolf A Venderbosch

Harm H Heikens

A toner powder for the development of latent electrostatic or magnetic images, the toner powder containing a polyester resin based on an etherified diphenol and a dicarboxylic acid mixed with a reaction product of an epoxy resin and a phenol compound or a carboxylic acid, and the process for forming fixed images on an image receiving material utilizing the above toner powder, the surface of an intermediate medium consisting of material having a lower affinity for the softened toner powder than does the image receiving material and the toner powder being softened by heating before and/or during transit through a pressure zone.

Toner powder for the development of latent electrostatic or magnetic

Colored magnetically attractable toner powder for the development of latent electrostatic or magnetic images consists of particles each comprising a magnetically attractable core, preferably spherical, formed of particulate magnetically attractable material or of a dispersion of such material in a binder, a masking layer enveloping the core and containing binder mixed with light-reflecting pigment of submicron particle size, and coloring material applied in and/or onto the masking layer. Processes for preparing the toner powder are disclosed, and a process for developing electrostatic or magnetic latent image patterns by its use.

Colored magnetically attractable toner powder, its preparation, and

Electrically conductive developer powder for developing electrostatic images by inductive attraction is provided, with avoidance of practical disadvantages of known 'one-component' developer powders, by incorporating finely divided water-insoluble quaternary ammonium salt into thermoplastic resin particles forming the powder, with or without other finely divided additives such as coloring material and/or magnetically attractable material. The specific resistance of the resin particles is lowered to between 10.sup.7 and 10.sup.11 ohm. cm by from 8 to 35% by weight of the quaternary ammonium salt, and can be lowered further by additions of fine conductive material such as carbon black. The resin particles remain sufficiently fusible even when they also contain enough magnetically attractable material, e.g. about 50% by weight, to render them transportable by a magnetic powder-applicator. A further important feature of the invention consists in preparing thermoplastic resin particles of suitable size with the quaternary ammonium salt already finely dispersed in them simply by coagulating an aqueous resin emulsion that contains one of the ions required for forming said salt, in a coagulant liquid containing the other of said ions. When so desired, the other additives can also be finely dispersed in these resin particles via the coagulant liquid.

Electrostatic image one-component electrically conductive thermoplastic

One-component developer powder and process for its preparation

Vinylpyrene (substituted or not) is prepared in a single reaction stage by reacting the corresponding acetylpyrene with a metal alkoxide, e.g. aluminum isopropoxide, in an inert organic solvent, e.g. a xylene, at a temperature above 110.degree. C. which, for some reaction conditions, optimally is between 130.degree. and 150.degree. C. The presence of hydroquinone in the mixture reduces the time and increases the yield of the reaction.

Process for the production of vinylpyrenes

Reproduction elements coated with organic photoconductors are made with improved and/or more widely selectable electrophotographic properties by employing in the photoconductive coating a donor-acceptor complex composed of a known organic electron donor having photo- or semiconductor properties, e.g. a poly-N-vinylcarbazole or polyvinylpyrene, and a N-(fluoren-9-ylidene)-aniline compound as an activating electron acceptor. Especially effective as the electron acceptor are certain new compounds, namely, p- and m-nitro-N-(2,4,7-trinitrofluoren-9-ylidene)-aniline and p-methylsulfonyl-N-(2,4,7-trinitrofluoren-9-ylidene)-aniline.

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Lottum, Netherlands

Gerardus J Crommentuyn