Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from GB848427456Aexternal-prioritypatent/GB8427456D0/en
Priority claimed from GB858512675Aexternal-prioritypatent/GB8512675D0/en
Application filed by Blue Circle Ind PlcfiledCriticalBlue Circle Ind Plc
Priority claimed from EP85307854Aexternal-prioritypatent/EP0181739B1/en
Application grantedgrantedCritical
Publication of ATE63532T1publicationCriticalpatent/ATE63532T1/en