A flux resin composition includes an epoxy resin, an imidazole compound, a thixo agent, and an activator. The epoxy resin includes at least one resin selected from the group consisting of naphthalene epoxy resins, biphenyl aralkyl epoxy resins, trisphenol methane epoxy resins, biphenyl epoxy resins, and dicyclopentadiene epoxy resins. The content of the at least one resin is equal to or greater than 20% by weight with respect to a total weight of the epoxy resin.

The present disclosure provides a resin composition for a metal substrate, and a resin varnish and a metal base copper-clad laminate comprising the same. The resin composition comprises 5-40% of a main resin and 60-95% of a thermally conductive filler when the total weight of the resin composition is calculated as 100%, wherein the main resin comprises 60-90% of a flexible epoxy resin having a structure as shown in Formula I and 10-40% of a phenoxy resin when the total weight of the main resin is calculated as 100%. The resin composition provided by the present disclosure has a low modulus, can alleviate the stress generated by thermal shocks and can withstand more than 1000 thermal cycles.

An epoxy resin, which is obtained by reacting at least a compound having one or more epoxy groups and a compound having a functional group that reacts with the epoxy groups, satisfies conditions (I) and/or (II): (I) the compound having a functional group that reacts with the epoxy groups includes a trihydric or higher phenol compound and/or a compound including a trifunctional or higher polyisocyanate; (II) the epoxy resin has an average degree of polyfunctionalization (X1) per molecule, as expressed by Formula (1), of 0.30 or more:

Average degree of polyfunctionalization (X1)=number of ends per molecule of epoxy resin−2.  Formula (1):

An object of the present invention is to provide an epoxy amine adduct, a curing catalyst, a resin composition, a sealing material, an adhesive agent, and a cured product, which have good characteristics. There is prepared an epoxy amine adduct in which a value of (melting onset temperature at a temperature increasing rate of 50° C./min)/(melting onset temperature at a temperature increasing rate of 10° C./min) in differential scanning calorimetry (DSC) is 1.00 or more and 1.10 or less. There are prepared a curing catalyst for epoxy resin containing the epoxy amine adduct, a resin composition containing the curing catalyst, a sealing material or an adhesive agent each containing the resin composition, and a cured product obtained by curing the resin composition.

An object of the present invention to provide an adhesive for an endoscope and a cured product of the adhesive, and an endoscope and a method for producing the endoscope. The adhesive is able to maintain sufficient adhesive strength even when exposed to high temperature for a long time in a state of being used for fixation of a member or subjected to powerful sterilization treatment with ozone water or the like and is suitable for use in fixing a member constituting the endoscope. The adhesive for an endoscope includes an epoxy resin, an epoxy resin curing component, and a radical scavenger.

A copolymer is formed by reacting a composition I, which includes (a) a first epoxy compound having a chemical structure of

##STR00001##

wherein R.sup.1 is single bond, —O—,

##STR00002##

(b) a second epoxy compound that is different from (a) the first epoxy compound, and (c) a curing agent. The copolymer can be mixed with inorganic powder to form a composite material.

Provided are a white heat-curable epoxy resin composition capable of yielding a cured product that is tough and superior in initial reflection rate and heat resistance; and a semiconductor device with a light receiving element and other semiconductor elements being encapsulated by such cured product. The white heat-curable epoxy resin composition contains: (A) a prepolymer as a molten mixture of (A-1) an epoxy resin: a triazine derivative epoxy resin and/or an alicyclic epoxy compound having an epoxy group and an alicyclic structure in one molecule and being non-fluid at 25° C., (A-2) an acid anhydride having no carbon-carbon double bond and (A-3) an acrylic resin-based modifier having an epoxy group and a weight-average molecular weight of 1,000 to 30,000; (B) a white pigment containing a titanium oxide; (C) an inorganic filler; (D) a curing accelerator; and (E) an antioxidant.

An epoxy adhesive composition having a higher level (at or above 5 wt %) of a blocked tertiary amine catalyst, a urethane toughener, an epoxy resin modified with liquid rubber, a core shell rubber toughener and a combination of liquid and solid epoxy resins and the making thereof.

Provided is a curable epoxy composition capable of forming a cured product having excellent heat resistance even in a high temperature environment. A first curable epoxy composition includes an alicyclic epoxy compound (A) having an alicyclic structure and an epoxy group in a molecule, an acid anhydride-based curing agent (B), and an imidazole-based curing accelerator (C), and is liquid at 25° C. and to be used for a rotary electric machine. A second curable epoxy composition includes an alicyclic epoxy compound (A) having an alicyclic structure and an epoxy group in a molecule, an acid anhydride-based curing agent (B), an imidazole-based curing accelerator (C), and a polyester polyol (D), and is to be used for a rotary electric machine.

This invention relates to a composition comprising a semisolid epoxy resin containing a curative dispersed therein. The curative has a particle size such that at least 90% of the particles have a size below 25 pm at ambient temperature of 21° C., wherein the composition further comprises a diluent containing a particulate filler. The composition is used as matrix in prepregs. The use of the diluent increases peel strength of the composition when brought into contact with metal or wood substrate.