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:
Oct. 21, 2008
Filed:
Dec. 28, 2005
Laurentius Cornelius Josephus Hesselmans, 's-Hertogenbosch, NL;
Andries Johannes Derksen, Nijmegen, NL;
Jacob Christiaan Munneke, Kaatsheuvel, NL;
Laurentius Cornelius Josephus Hesselmans, 's-Hertogenbosch, NL;
Andries Johannes Derksen, Nijmegen, NL;
Jacob Christiaan Munneke, Kaatsheuvel, NL;
Stahl International B.V., Waalwijk, NL;
Abstract
A process for the preparation of stable aqueous polycarbodiimide dispersions, to be used as crosslinking agent, which are free of organic solvents is described. Sid process is characterized in: reacting a polyisocyanate in the presence of a carbodiimide catalyst to form a polycarbodiimide, terminating and/or chain extending the polycarbodiimide chain by the addition of formation dispersion of the resulting compound in water, wherein pH is adjusted to a value between 9 and 14 by the addition of a base and/or a buffer to the water used for the dispersion and/or to the obtained aqueous dispersion. According to the present process said terminating or chain extending with the compound containing a hydrophylic group and one or more amine functions may also occur during or after the dispersion of the polycarboiimide in water. The preferred pH of the polycarbodiimide dispersions is between 11 and 13. Furthermore the invention related to a coating mixture comprising the polycarbodiimide dispersions obtained by the invention as crosslinking agent and an aqueous resin containing carboxylic acid functions. Finally the invention comprises cured material obtained by applying said coating mixture to a substrate, and evaporating the water.