摘要:
An insulation system for winding of electric rotating machines having thermal resistance of class H or more and excellent adhesiveness between a conductor and an insulating layer and resistance to thermal stress can be produced by wrapping a plurality of layers of an insulating tape or sheet having thermal resistance of class H or more around a winding conductor, impregnating the thus treated winding conductor with a solventless varnish consisting essentially of 1 equivalent of an epoxy compound containing at least two vicinal epoxy groups, more than one equivalent of an organic polyisocyanate, and then heating the inpregnated winding conductor at a temperature above 60.degree. C. for a time sufficient to form and cure a resin containing as recurring units at least two isocyanurate rings directly bonded to one another through the residue of the polyisocyanate and two oxazolidone rings directly bonded to each other through the residue of the polyepoxide in the presence of 0.01-10% by weight of a catalyst which forms the isocyanurate rings and oxazolidone rings based on the total amount of the polyepoxide and polyisocyanate.
摘要:
A thermosetting resin composition comprising a polyfunctional epoxy compound such as diglycidyl ether of bisphenol A, a polyfunctional isocyanate such as diphenylmethane diisocyanate, a curing agent and polybutadiene type polymer having terminal hydroxyl groups can produce cured articles excellent in heat resistance and crack resistance.
摘要:
A thermosettable, polymerizable resin composition comprising a polyepoxide and a polyisocyanate which is normally catalyzed by a basic curing catalyst for forming oxazolidone rings and isocyanurate rings or uredione rings is remarkably stabilized at low temperatures by incorporating a small amount of an organic electron acceptor, such as, picric acid, quinone, chloranil, or cyanoacetate ester into the composition. Since the specific electron acceptors effectively inhibit the polymerization of the reactive components in the composition at low temperatures, a shelf life of the composition is remarkably prolonged.
摘要:
A novel thermosetting resin can be obtained by mixing 1 equivalent or more of a polyfunctional isocyanate per 1 equivalent of a polyfunctional epoxide and then carrying out a polymerization reaction of the mixture in the presence of the catalyst which forms isocyanurate rings and oxazolidone rings so as to enable the mixture to form 2 or more isocyanurate rings directly connected with oxazolidone rings through an isocyanate residues.The resulting thermosetting resin has excellent electrical, chemical and impact resistances and excellent self-extinguishing properties. Said resin is used as an electric insulating material.
摘要:
Electric windings comprising an electric conductor and a plurality of cured insulating layers wrapping around the conductor, said cured insulating layers being obtained by bonding two or more insulating materials with a binder solution containing a mixture of a condensation polymerization type silicone resin containing hydroxyl groups in the molecule and an addition polymerization type silicone resin to form a composite insulating material, wrapping the composite insulating material around the conductor, impregnating the wrapped composite insulating material with an impregnating varnish of an epoxy-isocyanate resin and curing the impregnated composite insulating material, have excellent water resistance in addition to excellent thermal resistance, and mechanical properties.
摘要:
The present invention provides a thermosetting resin composition comprising(a) a prepolymer of a poly-p-hydroxystyrene derivative represented by the general formula ##STR1## wherein A is a halogen group, R.sub.1 is an alkenyl or alkenoyl group of 2 to 4 carbon atoms, 4 carbon atoms, m denotes a number of 1 to 4 and n denotes a number of 1 to 100,(b) an epoxy-modified polybutadiene, and(c) an aromatic maleimide compound, and a prepreg and a laminated sheet which use said resin composition.
摘要:
The present invention provides a thermosetting resin composition comprising(a) a prepolymer of a poly(p-hydroxystyrene) derivative represented by the general formula ##STR1## wherein A is a halogen group, R.sub.1 is an alkenyl or alkenoyl group of 2 to 4 carbon atoms, m denotes a number of 1 to 4 and n denotes a number of 1 to 100,(b) an epoxy-modified polybutadiene, and(c) an aromatic maleimide compound, and a prepreg and a laminated sheet which use said resin composition.
摘要:
A thermosetting resin composition comprising a special poly(p-hydroxystyrene) derivative resin and a radical polymerization initiator, and if necessary an epoxy modified polybutadiene, can provide prepregs and laminates having a low dielectric constant, a shorter signalling delay time, good heat resistance and flame retardancy and thus being suitable for producing multilayer printed circuit boards.
摘要:
The thermosetting resin composition of the present invention is prepared by mixing an aromatic cyanamide compound with a cyclic ester compound and/or a cyclic amide compound. Although a solventless type composition is preferable, the present invention is not limited thereto. The cured product of the present invention can be prepared by heating and curing said thermosetting resin composition. The obtained cured product of the present invention usually contains melamine rings, isomelamine rings and linear polyester and/or a linear polyamide units.
摘要:
A crosslinkable compound obtained by reacting an aromatic hydrocarbon-formaldehyde resin with an .alpha.,.beta.-unsaturated monocarboxylic acid or an ester thereof has no odor or very slight odor. Said crosslinkable compound can be radical polymerized at a low temperature to give a cured article having excellent electrical insulating properties. Said crosslinkable compound can also be used as one component of a resin composition containing an unsaturated polyester resin or a polybutadiene resin modified with acrylic or methacrylic acid to give an odorless or low-odor resin composition suitable for producing reinforced plastics, paints and varnishes, adhesives, electrical parts, etc.