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 US06/175,163external-prioritypatent/US4341676A/en
Application filed by Ppg Industries IncfiledCriticalPpg Industries Inc
Application grantedgrantedCritical
Publication of ATE13902T1publicationCriticalpatent/ATE13902T1/de