Abstract: Polyurea systems comprising: (a) an amino-functional aspartic ester of the general formula (I) wherein X represents an n-valent organic radical derived from a corresponding n-functional primary amine X(NH2)n, R1 and R2 each independently represent an organic radical having no Zerevitinov active hydrogens and n represents an integer of at least 2; and (b) an isocyanate functional prepolymer having a residual monomer content of less than 1% by weight, the prepolymer prepared by reacting: (b1) an aliphatic isocyante; and (b2) a polyol component having a number average molecular weight of ?400 g/mol and an average OH functionality of 2 to 6, wherein the polyol component comprises one or more constituents selected from the group consisting of polyester polyols, polyester-polyether polyols and mixtures thereof; processes for making the same; postoperative adhesions barriers prepared therewith and dispensing systems for such polyurea systems.
Type:
Grant
Filed:
February 13, 2009
Date of Patent:
April 7, 2015
Assignee:
Medical Adhesive Revolution GmbH
Inventors:
Heike Heckroth, Hartmut Nefzger, Christian Wamprecht
Abstract: An anionic cellulose nitrate derivative is described, which has: (i) a degree of acid group substitution (DS (acid)) in the range of 0.01 to 0.2; and (ii) a nitrogen content of 10.7 wt. % to 12.3 wt. %, based on the weight of cellulose nitrate derivative. The anionic cellulose nitrate derivative is prepared by a process which includes esterifying cellulose nitrate feed material with at least one dicarboxylic acid anhydride (e.g., maleic anhydride). Aqueous dispersions according to the present invention include: (a) at least on anionic cellulose nitrate derivative according to the present invention; and (b) at least one base.
Type:
Grant
Filed:
November 30, 2005
Date of Patent:
July 4, 2006
Assignee:
Wolff Cellulosics GmbH & Co. KG
Inventors:
Carsten Hüttermann, Thomas Wagner, Klaus Nachtkamp