The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 25, 1981
Filed:
Sep. 05, 1978
Adrianus M Hectors, Tegelen, NL;
Gerardus J Crommentuyn, Lottum, NL;
Oce-van der Grinten N.V., Venlo, NL;
Abstract
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.