Disclosed is a polyurethane-modified epoxy resin composition capable of satisfying both high toughness and high elasticity. This epoxy resin composition is an epoxy resin composition, in which (A) a polyurethane-modified epoxy resin having a polycarbonate structure in the molecule and having a urethane modification rate of 20 to 60% by weight, (B) a non-polyurethane-modified epoxy resin that is liquid at 30° C., (C) a solid epoxy resin having a glass transition temperature or melting point of 50° C. or higher and (D) an amine-based curing agent that is dicyandiamide or a derivative thereof are as essential components, and 20.0 to 50.0% by weight of (A), 0.1 to 50.0% by weight of (B) and 0.1 to 50.0% by weight of (C) are contained relative to the total of (A) to (D).

Disclosed is a polyurethane-modified epoxy resin composition capable of satisfying both high toughness and high elasticity. This epoxy resin composition is an epoxy resin composition, in which (A) a polyurethane-modified epoxy resin having a polycarbonate structure in the molecule and having a urethane modification rate of 20 to 60% by weight, (B) a non-polyurethane-modified epoxy resin that is liquid at 30° C., (C) a solid epoxy resin having a glass transition temperature or melting point of 50° C. or higher and (D) an amine-based curing agent that is dicyandiamide or a derivative thereof are as essential components, and 20.0 to 50.0% by weight of (A), 0.1 to 50.0% by weight of (B) and 0.1 to 50.0% by weight of (C) are contained relative to the total of (A) to (D).

Polyamide and amidoamine curing agents comprising a selectively modified amine. The selectively modified amine is formed by a substitution reaction between a polyamine and an epoxide, resulting in a multifunctional amine having a hydroxyl substituent. The curing agents are used to form epoxy resins having improved properties when cured.

Polyamide and amidoamine curing agents comprising a selectively modified amine. The selectively modified amine is formed by a substitution reaction between a polyamine and an epoxide, resulting in a multifunctional amine having a hydroxyl substituent. The curing agents are used to form epoxy resins having improved properties when cured.

The present invention provides a two-part thermal conductive epoxy adhesive composition with high bonding strength and low modulus. The present invention also provides a preparing method and use thereof.

A curing composition is useful for a multi-component epoxy resin compound and includes at least one first polyamine, at least one second polyamine, and at least one polyphenol from the group of bisphenols and novolac resins as an accelerator. Upon contact with atmospheric oxygen, the curing composition discolors within a few days and therefore leakages can be visually identified.

A curing composition is useful for a multi-component epoxy resin compound and includes at least one first polyamine, at least one second polyamine, and at least one polyphenol from the group of bisphenols and novolac resins as an accelerator. Upon contact with atmospheric oxygen, the curing composition discolors within a few days and therefore leakages can be visually identified.

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.

Provided is a curing agent for a water-based epoxy resin, which contains the following component (A) and component (B): (A); at least one selected from the group consisting of a polyamide amine-based curing agent (a1), a reaction product (a2) of a polyamine compound and a polyepoxy compound, and a Mannich reaction product (a3) of a polyamine compound, a phenol compound, and an aldehyde compound; (B): at least one selected from the group consisting of a reaction product (b1) of styrene and an amine compound represented by the following formula (1), and a reaction product (b2) of epichlorohydrin and an amine compound represented by the following formula (1);
H.sub.2N—CH.sub.2-A-CH.sub.2—NH.sub.2  (1) wherein A is a 1,2-phenylene group, a 1,3-phenylene group, or a 1,4-phenylene group.