申请人:Clariant GmbH
公开号:US06359171B1
公开(公告)日:2002-03-19
The invention relates to a process for the preparation of dialkylphosphinic acids and salts thereof, which comprises
a) reacting elemental yellow phosphorus with alkylating agents in the presence of a base to give a mixture which comprises, as principal constituents, the (metal) salts of alkylphosphonous, phosphorous and hypophosphorous acids,
b) esterifying the principal constituents of the mixture from a) to give an ester mixture,
c) isolating the ester of the alkylphosphonous acid from the ester mixture,
d) preparing the corresponding ester of the dialkylphosphinic acid from the ester of the alkylphosphonous acid by free-radical-initiated reaction with olefins,
e) converting the ester of the dialkylphosphinic acid into the free acid or into the dialkylphosphinic acid salts of metals from groups IA, IIA, IIIA, IVA, VA, IIB, IVB, VIIB or VIIIB of the Periodic Table or of cerium.
The invention likewise relates to the use of the dialkylphosphinic acids/salts prepared by this process for the preparation of various products, in particular flame retardants.
本发明涉及一种制备二烷基膦酸及其盐的方法,包括以下步骤:a) 在碱的存在下,将元素黄磷与烷基化试剂反应,得到混合物,其中主要成分为烷基膦酸、亚磷酸和次亚磷酸的(金属)盐,b) 酯化步骤,将混合物中的主要成分酯化,得到酯混合物,c) 从酯混合物中分离烷基膦酸酯,d) 通过自由基引发的与烯烃反应,从烷基膦酸酯制备相应的二烷基膦酸酯,e) 将二烷基膦酸酯转化为自由酸或来自周期表IA、IIA、IIIA、IVA、VA、IIB、IVB、VIIB或VIIIB或铈的金属盐的二烷基膦酸盐。本发明还涉及使用通过该方法制备的二烷基膦酸/盐制备各种产品,特别是阻燃剂。