Single resin polybutadiene and polyisoprene thermosetting compositions and method of manufacture thereof
US5858887A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 1, 1996 |
| Grant date | Jan 12, 1999 |
| Priority date | — |
| Expiry date | Aug 1, 2016 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T442/3455
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
An electrical substrate material is presented comprising a thermosetting matrix of polybutadiene or polyisoprene in an amount of 25 to 50 volume %; a woven glass fabric in an amount of 10 to 40 volume %; a particulate, preferably ceramic filler, in an amount of from 5 to 60 volume %; and a flame retardant. Importantly, the composition comprises only a single resin, i.e., polybutadiene or polyisoprene. A peroxide cure initiator and/or crosslinking agent may optionally be added. The presence of a very high surface area particulate filler, preferably fumed silica, is also preferred, in that its presence results in a prepreg which has very little tackiness and can therefore be easily handled by operators. This low tackiness feature allows for the use of conventional automated layup processing, including foil cladding, using one or more known roll laminators. While the prepreg of this invention is tack-free enough to be handled relatively easily by hand, it is also tacky enough to be tacked to itself using a roll laminator (e.g., nip roller) at room temperature. The composition of this invention is particularly well suited for making electrical circuit substrates for microwave and digit…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.