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Priority claimed from US06/465,703external-prioritypatent/US4452930A/en
Priority claimed from US06/465,704external-prioritypatent/US4452681A/en
Priority claimed from US06/465,702external-prioritypatent/US4452963A/en
Application filed by Ppg Industries IncfiledCriticalPpg Industries Inc
Priority claimed from EP19840101168external-prioritypatent/EP0118743B1/de
Application grantedgrantedCritical
Publication of ATE27809T1publicationCriticalpatent/ATE27809T1/de