摘要 |
This invention relates to an improved polyimide resin and to a method of its production. The improved polyimide resin is made from phenanthrene which is converted via a 9, 10-diol to oligomers of diphenic anhydride units linked by keto bridges. The oligomers are reacted with from 0.1 to 0.6 of an equivalent quantity of an aromatic primary diamine. The remaining anhydride groups are reacted with a monofunctional amine to give a polyimide of low cross-link density. The resin will find use for instance in forming glasscloth laminates. |