| 摘要 |
1,165,983. Epoxy resins. DOW CHEMICAL CO. 21 Nov., 1967 [21 Nov., 1966], No. 52965/67. Heading C3B. Synthetic resins which pass through a " B- stage," i.e. a partially cured stage at which they are still softened by heating (especially epoxy resins) are stretched whilst still in the " B-stage " before curing to a rigid infusible state. The stretching which may be monodirectional or biaxial may be achieved by applying sufficient pressure, e.g. fluid pressure, to cause the partially cured resin to flow and maintaining such pressure until the body no longer flows or deforms. The resin may be first applied to a film of synthetic resin, e.g. polyethylene terephthalate, before stretching. |
