| 摘要 |
<p>1383985 Polyimide coated films RHONEPOULENC SA 28 April 1972 [30 April 1971] 19903/72 Heading B2E A polyimide or polyamide-imide film has an adhesive coating on at least one side thereof of a polyimide consisting essentially of recurring units of the formula: in which "M" represents an aliphatic, cycloaliphatic aromatic or heterocyclic divalent radical. The coating optionally contains a polar solvent. A list of suitable radicals "M" is given, examples being in example 1 and in examples 2 to 6. The sheet is made of a polymer having the recurring unit: where M is as before, R represents aliphatic, cycloaliphatic, aromatic, or heterocyclic tetravalent organic radical containing at least two carbon atoms, and R' is as R but trivalent. Many precursor anhydrides containing examples of R, R' are listed. Preferred polyamide-imides are the reaction products of trimellitic anhydride with 4, 4'-diisocyanato-diphenyl ether (Examples 1, to 4 and 6) and of pyromellitic acid with 4, 4'-diaminophenyl ether (Example 5). The film is preferably stretched and treated, for example by electrical discharge and/or cleaning, before being coated by soaking, spreading, or spraying, solvent being removed by heating optionally under reduced pressure. Films are useful for bonding printed circuit boards and for wrapping electrical conductors.</p> |
