申请人:Baker Hughes Incorporated
公开号:US06342647B1
公开(公告)日:2002-01-29
It has been discovered that the polymerization of vinyl aromatic compounds, such as styrene, may be inhibited by the addition of a composition that contains a hindered hydroxylamine, and, optionally, a synergist together with the hindered hydroxylamine. In one embodiment of the invention, the hindered N,N-disubstituted hydroxylamine has the formula:
[(R1R2R3)C]2N—OH
where R1, R2, and R3 are independently selected from the group consisting of hydrogen, straight, branched or cyclic alkyl, aryl, aralkyl, and alkaryl moieties; where no more than two of R1, R2, and R3 on each C can be hydrogen at a time; where one or more of R1, R2, and R3 on one C may be joined to a R1, R2, and R3 on the other C to form a cyclic moiety selected from the group consisting of alkylene, and aralkylene moieties; where any two of the R1, R2, and R3 on any one C may be joined together to form a cycloalkyl; where any of the above definitions of R1, R2, and R3 may contain one or more heteroatoms selected from the group consisting of N, O and S; and where the total number of carbon atoms in the hindered N,N-disubstituted hydroxylamine ranges from 6 to 70. Optional synergists may include alkyl-substituted hydroxyarenes such as 2,5-di-tert-butylhydroquinone, and hydrogen transfer agents such as 1,2,3,4-tetrahydronaphthalene; and the like, and mixtures thereof.
发现可以通过添加含有受阻羟胺的组合物(以及可选的协同剂)来抑制乙烯芳香化合物(例如苯乙烯)的聚合。在发明的一种实施方案中,受阻N,N-二取代羟胺的化学式为:[(R1R2R3)C]2N—OH,其中R1、R2和R3分别选自氢、直链、支链或环烷基、芳香基、芳基烷基和烷基芳基基团,每个C上的R1、R2和R3中最多只能有两个是氢,一个C上的R1、R2和R3中的一个或多个可以与另一个C上的R1、R2和R3结合形成所选的环烷基和芳烷基基团,任何一个C上的R1、R2和R3中的任意两个可以结合形成环烷基,上述R1、R2和R3的任何定义都可以包含从N、O和S中选择的一个或多个杂原子,受阻N,N-二取代羟胺中的碳原子总数范围为6到70。可选的协同剂可以包括烷基取代的羟基芳香烃,例如2,5-二叔丁基对苯二酚,以及氢转移剂,例如1,2,3,4-四氢萘等,以及它们的混合物。