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US4680377A Expired / Lapsed US ⏱️ 0.0 years remaining

Polyimide prepolymer composition from unsaturated bisimide and diamine containing unreacted reactants

Assignee: Panasonic Electric Works Co Ltd
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Filing: 1985-12-05
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Granted: 1987-07-14
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Expires: 2005-12-05
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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

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-05 19:22
CPC Classifications
C; C08; C08G; C08G73/00; C08G73/06; C08G73/10; C08G73/12; C08G73/121; C08J; C08J5/00; C08J5/24; C08J5/241; C08J5/244; C08L; C08L79/00; C08L79/04; C08L79/08; C08J2379/00; C08J2379/04; C08J2379/08; H; H05; H05K; H05K1/00; H05K1/02; H05K1/03; H05K1/0313; H05K1/032; H05K1/0346

Claims Analysis

Total Claims: 5
Claim 1
Independent Claim 61 words
A polyimide prepolymer composition of addition reaction obtained by reacting an unsaturated bisimide with a diamine; said composition consisting 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 and wherein the molecular weight is measured by Gel Permeation Chromatography Analysis.
Claim 2
Dependent Claim 61 words
A polyimide prepolymer composition of addition reaction obtained by reacting an unsaturated bisimide with a diamine; said composition consisting 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 and wherein the molecular weight is measured by Gel Permeation Chromatography Analysis.
Claim 3
Dependent Claim 29 words
A polyimide prepolymer as set forth in claim 1, wherein the molar ratio of the unsaturated bisimide remaining unreacted to the diamine remaining unreacted is between 1.7 to 2.5.
Claim 4
Dependent Claim 139 words
A prepreg produced by the following steps of: reacting an unsaturated bisimide with a diamine so as to prepare a polyimide prepolymer composition of addition reaction consisting 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 with the molecular weight measured by Gel Permeation Chromatography Analysis; dissolving the resulting prepolymer composition in a solvent to form a solution; impregnating a suitable substrate with the solution to prepare resin impregnated substrate; and partially curing the resin impregnated substrate to such an extent that resin content thereof consists essentially of 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.
Claim 5
Dependent Claim 139 words
A prepreg produced by the following steps of: reacting an unsaturated bisimide with a diamine so as to prepare a polyimide prepolymer composition of addition reaction consisting 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 with the molecular weight measured by Gel Permeation Chromatography Analysis; dissolving the resulting prepolymer composition in a solvent to form a solution; impregnating a suitable substrate with the solution to prepare resin impregnated substrate; and partially curing the resin impregnated substrate to such an extent that resin content thereof consists essentially of 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.

References Cited (Backward Citations)

US3562223A Cited
US3658764A Cited

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

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