The present invention provides an epoxy resin composition that serves to produce a cured epoxy resin that simultaneously realizes a high heat resistance, a high elastic modulus, and a low color and to produce a molded article having a good appearance without suffering the formation of white spots on the surface thereof when used as matrix resin in a fiber reinforced composite material. The epoxy resin composition includes an epoxy resin as component [A] and an imidazole compound as component [B] and meets certain conditions (a) to (d).

The present invention provides an epoxy resin composition that serves to produce a cured epoxy resin that simultaneously realizes a high heat resistance, a high elastic modulus, and a low color and to produce a molded article having a good appearance without suffering the formation of white spots on the surface thereof when used as matrix resin in a fiber reinforced composite material. The epoxy resin composition includes an epoxy resin as component [A] and an imidazole compound as component [B] and meets certain conditions (a) to (d).

A crosslinking composition includes a compound having at least two functional groups that are each independently represented by Chemical Structure (I):

##STR00001##

X is an oxygen, sulfur, or nitrogen; R.sup.1 is an alkyl group, an aryl group, or an alkylaryl group; R.sup.2, R.sup.3, and R.sup.4 are each independently an alkyl group, an aryl group, an alkylaryl group, or a hydrogen; R.sup.5 is an alkyl group, an aryl group, an alkylaryl group, or a hydrogen; z is 0 when X is oxygen or sulfur and z is 1 when X is nitrogen; and when a double bond is formed between a carbon atom bonded to R.sup.3 and an adjacent nitrogen, m is 0, and when a single bond is formed between the carbon atom bonded to R.sup.3 and the adjacent nitrogen, m is 1.

There is provided an epoxy resin composition containing an epoxy compound, which has a low viscosity and a low dielectric constant, and when added to a general-purpose epoxy resin composition, can lower a viscosity of the composition and can sufficiently lower a dielectric constant of an epoxy resin cured product obtained from the composition. An epoxy resin composition comprising: (a) an epoxy component containing at least an epoxy compound of formula [1]; and (b) a curing agent: ##STR00001##
wherein R.sup.1 to R.sup.3 each independently are a hydrogen atom or methyl group, and L.sup.1 to L.sup.3 each independently are pentamethylene group, hexamethylene group or heptamethylene group.

There is provided an epoxy resin composition containing an epoxy compound, which has a low viscosity and a low dielectric constant, and when added to a general-purpose epoxy resin composition, can lower a viscosity of the composition and can sufficiently lower a dielectric constant of an epoxy resin cured product obtained from the composition. An epoxy resin composition comprising: (a) an epoxy component containing at least an epoxy compound of formula [1]; and (b) a curing agent: ##STR00001##
wherein R.sup.1 to R.sup.3 each independently are a hydrogen atom or methyl group, and L.sup.1 to L.sup.3 each independently are pentamethylene group, hexamethylene group or heptamethylene group.

The present invention relates to a polyester elastomer resin composition containing: (A) a thermoplastic polyester elastomer; (B) a di- or higher functional epoxy compound; (C) an organic carboxylic acid alkali metal salt having 3 to 40 carbon atoms; (D) an inorganic crystal nucleating agent; and (E) a urea compound scavenger having an amine value of 50 eq/t or more, wherein per 100 parts by mass of component (A), component (B) is present in an amount of 0.1 to 5 parts by mass, component (D) is present in an amount of 0 to 3 parts by mass, and component (E) is present in an amount of 0.1 to 5 parts by mass; component (C), on an alkali metal basis, is present in an amount of 50 to 2000 ppm in the polyester elastomer resin composition on a mass basis.

The present invention relates to a polyester elastomer resin composition containing: (A) a thermoplastic polyester elastomer; (B) a di- or higher functional epoxy compound; (C) an organic carboxylic acid alkali metal salt having 3 to 40 carbon atoms; (D) an inorganic crystal nucleating agent; and (E) a urea compound scavenger having an amine value of 50 eq/t or more, wherein per 100 parts by mass of component (A), component (B) is present in an amount of 0.1 to 5 parts by mass, component (D) is present in an amount of 0 to 3 parts by mass, and component (E) is present in an amount of 0.1 to 5 parts by mass; component (C), on an alkali metal basis, is present in an amount of 50 to 2000 ppm in the polyester elastomer resin composition on a mass basis.

Disclosed are compositions relating to optically clear epoxy resin formulations with filler compositions having superior regular transmission of light between 350 nm and 2500 nm, and a low coefficient of thermal expansion, along with optoelectronic devices sealed with the same.

Disclosed are compositions relating to optically clear epoxy resin formulations with filler compositions having superior regular transmission of light between 350 nm and 2500 nm, and a low coefficient of thermal expansion, along with optoelectronic devices sealed with the same.

A curable epoxy composition, comprising: 100 parts by weight of an epoxy resin composition comprising one or more epoxy resins, each independently having an epoxy equivalent weight of at least 2; 30 to 200 parts by weight of an aromatic dianhydride curing agent of formula (1)

##STR00001##

wherein T is O, S, C(O), SO.sub.2, SO, C.sub.yH.sub.2y wherein y is an integer from 1 to 5 or a halogenated derivative thereof, or OZO wherein Z is an aromatic C.sub.6-24 monocyclic or polycyclic moiety optionally substituted with 1 to 6 C.sub.1-8 alkyl groups, 1 to 8 halogen atoms, or a combination comprising at least one of the foregoing, wherein the composition does not contain a catalyst.