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:
Sep. 20, 1983
Filed:
May. 20, 1981
Herbert Greinecker, Hallein, AT;
Gerhard Stern, Linz, AT;
Abstract
A filler for paper, card or board which has a good retention and consists of an inert core material and a hydrophilic coating, which consists of polyacrylamide having a molecular weight of 10.sup.5 to 10.sup.7 or of a mixture of this polyacrylamide with a urea-formaldehyde condensation resin. The filler is prepared by suspending the inert core material in an aqueous solution of a polyacrylamide having a molecular weight of 10.sup.5 to 10.sup.7 or in an aqueous solution of such a polyacrylamide and a urea-formaldehyde condensation resin, and drying this suspension by spray drying or in a stream of hot air. This crosslinks the initially water-soluble polymer and forms a coating, adhering to the core, which is insoluble in water but is hydrophilic and swells, and becomes tacky, in the presence of water.