The present invention aims to provide a means by which a cured product to be obtained has a low dielectric loss tangent and higher heat resistance. Specifically, provided is an active ester resin that is a reaction product of a first aromatic compound having two or more phenolic hydroxy groups, a second aromatic compound having a phenolic hydroxy group, and a third aromatic compound having two or more carboxy groups and/or an acid halide thereof or an esterified compound thereof, in which at least one of the first aromatic compound, the second aromatic compound, and the third aromatic compound and/or the acid halide thereof or the esterified compound thereof has an unsaturated bond-containing substituent.

The present teachings contemplate a method that includes a step of providing a first amount of esterified reaction product of an acid and an epoxy-based material. The esterified reaction product may be further reacted an epoxy resin to form a polymeric epoxy. The resulting material may have a generally linear backbone, foaming and curing capability and flame retardant properties.

A crosslinkable composition containing: a liquid monocyclic olefin ring-opened polymer (A) having a reactive group at a polymer chain end thereof and a weight-average molecular weight (Mw) of 1,000 to 50,000; and a crosslinkable compound (B) having, in the molecule, two or more functional groups reactive with the reactive group at the polymer chain end of the monocyclic olefin ring-opened polymer (A).

The invention relates to a potting paste composition for honeycomb reinforcement having improved fire retardancy characteristics. The potting paste composition comprises (a) a curable polymer; (b) a curing agent for the curable polymer; (c) a fire retardant comprising an ammonium polyphosphate in combination with an ingredient selected from the group consisting of metal hydroxides, expandable graphites, liquid phosphate esters, phosphorous organic compounds or salts thereof, and zeolites; and(d) a filler selected from the group consisting of polymeric microspheres, hollow glass microspheres, and thixotropic fillers; wherein the potting paste has an uncured density determined by the method according to EN ISO 1183 of not more than 0.7100 g/cm.sup.3, preferably of at most 0.680 g/cm.sup.3, more preferably of at most 0.673 g/cm.sup.3, still more preferably of at most 0.660 g/cm.sup.3, even more preferably of at most 0.658 g/cm.sup.3, yet more preferably of at most 0.653 g/cm.sup.3 and in particular of at most 0.620 g/cm.sup.3; and wherein the total content of the fire retardant is at least 5.0 wt.-%, preferably at least 10 wt.-%, more preferably at least 15 wt.-%, relative to the total weight of the potting paste composition.

The present disclosure relates to a method for manufacturing an ultra-low-temperature, fast-curable epoxy resin and a powder coating composition comprising a resin manufactured thereby and, specifically, to a method for manufacturing an ultra-low-temperature, fast-curable epoxy resin and a powder coating composition comprising a resin manufactured thereby, wherein the epoxy resin is curable in conditions of 110-130° C./10 min and thus can be used even in a material, of which the temperature is difficult to raise or which is sensitive to heat.

Provided is a thermosetting resin composition including an epoxy resin and thermally conductive particles. A thermal conductivity λ.sub.200 at 200° C. of a cured product obtained by heating the thermosetting resin composition at 200° C. for 90 minutes is 12 W/(m.Math.K) or higher. In addition, a volume resistivity R.sub.200 of the cured product at 200° C. is preferably 1.0×10.sup.10 Ω.Math.m or more. In addition, a resin sheet using this thermosetting resin composition is provided. Furthermore, a metal base substrate using this thermosetting resin composition is provided.

A sheet molding compound which is a thickened material of an epoxy resin composition, including a component (A), a component (B), and a component (C), in which the component (A) is an epoxy resin staying at a liquid state at 25° C., the component (B) is an acid anhydride, the component (C) is an epoxy resin curing agent, and in the thickened material, at least some of epoxy groups of the component (A) and at least some of carboxy groups derived from the component (B) form ester.

Epoxy curing agents are disclosed having an epoxy curing agent comprising at least one room temperature ionic liquid salt, the room temperature ionic liquid salt being a reaction product of (a) at least one polyalkylene polyamine compound represented by formula (I):

##STR00001##

wherein x, y, and z are integers of 2 and 3, m and n and integers of 1-3; and (b) an organic acid having pKa (the negative of the logarithm of the acid dissociation constant) less than 6. The liquid salt is a stable liquid at a temperature greater than 15° C. Curable epoxy-based compositions including the curing agent and articles formed by the curable epoxy-based compositions are also disclosed.

Epoxy curing agents are disclosed having an epoxy curing agent comprising at least one room temperature ionic liquid salt, the room temperature ionic liquid salt being a reaction product of (a) at least one polyalkylene polyamine compound represented by formula (I):

##STR00001##

wherein x, y, and z are integers of 2 and 3, m and n and integers of 1-3; and (b) an organic acid having pKa (the negative of the logarithm of the acid dissociation constant) less than 6. The liquid salt is a stable liquid at a temperature greater than 15° C. Curable epoxy-based compositions including the curing agent and articles formed by the curable epoxy-based compositions are also disclosed.

A resin producing method is a method of producing a resin with which an insulating structure formed on an outer peripheral portion of a conductor is impregnated, the method including: a filler mixing step of mixing a nanofiller at a ratio of 15 wt % or more with an epoxy resin to form a mixture; a shear mixing step of causing the mixture to be subjected to shear mixing; a diluent mixing step of mixing a reactive diluent that reduces a viscosity of the epoxy resin, with the mixture after the shear mixing step; and a curing agent mixing step of mixing an acid anhydride curing agent with the mixture after the diluent mixing step.