Polyimide prepolymer composition from unsaturated bisimide and diamine containing unreacted reactants
Abstract
Abstract Superior polyimide prepolymers particularly suitable for fabrication of multi-layer printed boards are produced by reacting unsaturated bisimides with diamines to consist essentially of 41-55% of unreacted reactants, 39-54% of components having a molecular weight of between 400 and 15,000, and 3.0-6.8% of components having a molecular weight of more than 15,000. The resulting prepolymers enable the preparation of their solution having enough working life for successfully impregnating a given substrate therewith in the preparation of prepregs. The prepregs, prepared from the above prepolymers in such a way as to contain within the resin content thereof 29-35% of unreacted reactants, 51-65% of the components having a molecular weight of between 400 and 15,000, and 5-14% of the components having a molecular weight of more than 15,000, allow the fabrication of laminate products with remarkable dimension stability under a low molding pressure to eliminate the presence of voids in the products, in addition to that the prepregs ensure a high bond strength as well as elongated working life which is responsible for prevention of a blister in the finished laminate and for easy control of the laminate forming process.
Inventors
- 👤 Masahiro Matsumura
- 👤 Kenzi Ogasawara
- 👤 Atsuhiro Nakamoto
- 👤 Yoshihisa Sugawa
Bibliographic Details
Claims Analysis
Total Claims: 5References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-07-13 | 1991-01-12 | 1991-07-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-07-13 | 1995-01-12 | 1995-07-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-07-13 | 1999-01-12 | 1999-07-14 | $7700.00 | Window Closed / Lapsed |