| 摘要 |
A film is disclosed, containing 40-100 weight percent polyimide. The polyimide is derived from a dianhydride component and a diamine component. The dianhydride component is at least 3,3′,4,4′-biphenyl tetracarboxylic dianhydride (BPDA), and optionally is also pyromellitic dianhydride (PMDA) in a mole ratio of 50-100:50-0 (BPDA:PMDA). The diamine component comprises 1,5-naphthalenediamine (1,5-ND) and 1,4-diaminobenzene (PPD) and/or meta phenylene diamine (MPD) in a mole ratio of 15-95:85-5 (1,5-ND:PPD+MPD). The films have exceptional high temperature storage modulus (elastic modulus) and exceptionally low high temperature creep (eplast).
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