Matsushita Electric Works, Ltd.

Yukio Hatta

Yoshihiko Nakamura

Masahiro Matsumura

Yasuo Fukuhara

Narimasa Iwamoto

Hidetsugu Motobe

Masaharu Yamamoto

Takayuki Fukuda

Kiyohiro Nagao

Makizi Miyao

Shigekazu Takanohashi

Akihiro Atsumi

Hiroshi Toshima

An epoxy resin composition featured in containing, in a matrix of an epoxy resin having more than two epoxy groups in each molecule, a phenolic hardening agent having more than two phenolic hydroxyl groups in each molecule, an organobis(N-dialkylurea) hardening promotion agent, a solvent for the hardening promotion agent, and a guanamine compound, and capable of obtaining a prepreg excellent in the preservation stability and, less causing a solvency errosion (halo phenomenon) due to an infiltration of plating solution along boundaries between a printed copper circuit formed in an inner-layered circuit board and a resin forming the prepreg, is realized.

Prepreg of epoxy resin, hardener, and organodialkyurea promotor

In a process for manufacturing a prepreg for use as an electrically insulating material, a main epoxy resin composition and a subsidiary resin composition containing a hardener which have been separately filtered and metered are quickly mixed into a mixture resin composition, a reinforcing member is coated with a uniformly thin film of the mixture resin composition by a die coater under specific temperature, average residence time and low shear conditions, the coated reinforcing member is heated in non-contact manner by an infrared ray heater to have the member impregnated with the resin composition of the film, the member is further heated in non-contact manner by a floating dryer to have the resin composition semi-hardened, and the member is unified through compaction rolls, whereby the prepreg in the form of a sheet-shaped fiber reinforced composite material is continuously manufactured.

Process for manufacturing prepregs for use as electric insulating

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Kadoma, Japan

Yukio Hatta