PROCESSES FOR PRODUCING ARYL CARBAMATES, ISOCYNATES AND POLYUREAS USING DIARYL CARBONATE
申请人:Dai Shenghong A.
公开号:US20130079542A1
公开(公告)日:2013-03-28
A preparation of aryl carbamates can be achieved readily by carbonylation of an aromatic polyamine compound with diphenyl carbonate (DPC) using a combination of an organic acid and a tertiary amine as a catalyst. Aryl carbamate can be converted into 4,4′-diphenylmethane diisocyanate (MDI) by heating it at about 200 to about 230° C. in a non-polar solvent containing inhibitor such as benzoyl chloride. In another application, trans-ureation of biscarbamates with an amine or mixed amines is found to be extremely facile in a polar solvent such as dimethyl sulfoxide (DMSO) and tetramethylene sulfone (TMS) in absence of any catalyst to make polyurea polymers of high molecular weights. Thus, efficient green-chemistry processes based on biscarbamates in making isocyanate products as well as urea prepolymers, urea elastomers and urea plastics have been developed in all in excellent yields without using reactive phosgene or 4,4′-diphenylmethane diisocyanate separately in the trans-ureation polymerizations.
芳基氨基甲酸酯的制备可通过芳香族多胺化合物与二苯基碳酸酯(DPC)在有机酸和三级胺的催化剂作用下进行羰基化而轻松实现。将芳基氨基甲酸酯加热至约200至230°C,在含有苯甲酰氯等抑制剂的非极性溶剂中,可将其转化为4,4′-二苯甲烷二异氰酸酯(MDI)。在另一个应用中,使用极性溶剂如二甲基亚砜(DMSO)和四甲基砜(TMS)中,通过与胺或混合胺进行双氨基甲酸酯的转尿素化,在无催化剂的情况下制备高分子量的聚脲聚合物是非常容易的。因此,基于双氨基甲酸酯的高效绿色化学过程已经开发出以优异产率制备异氰酸酯产品、尿素预聚合物、尿素弹性体和尿素塑料的方法,而无需在转尿素聚合过程中单独使用反应性的光气或4,4′-二苯甲烷二异氰酸酯。