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Priority claimed from US06/162,225external-prioritypatent/US4297261A/en
Priority claimed from US06/162,224external-prioritypatent/US4294741A/en
Application filed by Ppg Industries, Inc.filedCriticalPpg Industries, Inc.
Priority claimed from EP19810104172external-prioritypatent/EP0042502B1/de
Application grantedgrantedCritical
Publication of ATE7704T1publicationCriticalpatent/ATE7704T1/de