FILM DE POLYESTER BIAXIALEMENT ORIENTE, SON PROCEDE DE PREPARATION ET SON APPLICATION COMME SUPPORT DE BANDE MAGNETIQUE

• Main Author: MARIE-ODILE JACQUIER ET JACQUES BARBEY
• Format: Patent
• Language: French
• Published: 06.01.1984
• Subjects: AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING; INFORMATION STORAGE; INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORDCARRIER AND TRANSDUCER; PERFORMING OPERATIONS; PHYSICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDEDFOR; SHAPING OR JOINING OF PLASTICS; TRANSPORTING; WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE, IN GENERAL

FILM DE POLYESTER BIAXIALEMENT ORIENTE PRESENTANT UNE VISCOSITE INTRINSEQUE DE 0,6-0,75 DLG, UN COEFFICIENT D'ORIENTATION CRISTALLINE SUPERIEUR A 0,78, UN MODULE LONGITUDINAL D'AU MOINS 800 KGMM ET UNE STABILITE DIMENSIONNELLE TRANSVERSALE DE 0-0,5 DE RETRAIT A 105C ET DE 1,5-2,5 DE RETRAIT A 150C.LE FILM EST OBTENU PAR PRECHAUFFAGE D'UN FILM POLYESTER, ETIRAGE TRANSVERSAL SUIVI D'UN TRAITEMENT THERMIQUE, ETIRAGE LONGITUDINAL, THERMOFIXATION DU FILM BIETIRE PUIS RELAXATION.LE FILM PEUT ETRE UTILISE COMME SUPPORT POUR BANDE MAGNETIQUE. Biaxially oriented polyester film with an intrinsic viscosity of 0.6-0.75 dl/g, a crystalline orientation coefficient higher than 0.78, a lengthwise modulus of at least 800 kg/mm and a transverse dimensional stability of 0-0.5 % shrinkage at 105 DEG C and 1.5-2.5 % shrinkage at 150 DEG C. The film is obtained by heating a polyester film, transverse drawing followed by a heat treatment, lengthwise drawing, heat-setting of the biaxially drawn film and then relaxation. The film can be employed as a base for magnetic tape.