Provided are a thermosetting resin composition containing polyester amide acid (A), epoxy compound (B) having a fluorene skeleton, epoxy curing agent (C) and colorant (D), and the thermosetting resin composition capable of forming a cured film having an excellent balance of satisfactory hardness and adhesion to glass under high-temperature conditions, and also an application of the thermosetting resin composition.

A hardener composition for epoxy resins includes a dianhydride and one or both of a monoanhydride and a hydroxyl-diterminated poly(phenylene ether). The hardener components can be blended in the substantial absence of solvent to yield a homogeneous composition having a reduced glass transition temperature or melting point that facilitates reduced-temperature blending of the hardener composition with the epoxy resin.

A one-component heat-curing epoxy resin adhesive has at least one epoxy resin having an average of more than one epoxy group per molecule; at least one latent hardener for epoxy resins; and at least one carboxylic acid selected from substituted or unsubstituted adipic acid, substituted or unsubstituted succinic acid, substituted or unsubstituted phthalic acid, substituted or unsubstituted terephthalic acid, substituted or unsubstituted isophthalic acid, substituted or unsubstituted benzenetricarboxylic acid and substituted or unsubstituted nitrobenzoic acid, excluding 2-hydroxysuccinic acid and 2,3-dihydroxysuccinic acid as carboxylic acid, and wherein the epoxy resin adhesive contains 0.0015 to 0.04 mol of the at least one carboxylic acid per 100 g of the epoxy resin adhesive and the epoxy resin adhesive has a viscosity of 500-5000 Pas at 25 C. The epoxy resin adhesive is notable for a very heat-resistant bond on particular metal substrates such as steel having a zinc-magnesium coating.

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 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 are an active ester compound represented by chemical formula (1):

##STR00001## (where in chemical formula (1), Ar.sup.1 is a substituted or unsubstituted first aromatic ring group, and each Ar.sup.2 is independently a substituted or unsubstituted second aromatic ring group, in which at least one of Ar.sup.1 and Ar.sup.2 has an unsaturated bond-containing substituent, and n is an integer of 2 or 3), a curable composition containing the active ester compound, and a cured product thereof.

Provided are an epoxy resin composition and a prepreg, laminated board and printed-circuit board comprising same. The epoxy resin composition comprises the following components: (A) 38-54 parts by weight of an epoxy resin comprising a DCPD structure; (B) 30-36 parts by weight of an active ester curing agent; and (C) 16-32 parts by weight of a cyanate resin, With the mutual cooperation and synergistic facilitation effects of the particular contents of the three essential components, the epoxy resin composition is obtained. Under the premise of having a high resistance to heat and humidity and a high heat resistance at the same time, the prepreg, laminated board and printed-circuit board made of the epoxy resin composition further have a low thermal expansion coefficient, a low water absorption rate and excellent dielectric properties.

A flexible encapsulating material, a method for preparing the flexible encapsulating material, and an encapsulating method using the flexible encapsulating material are provided. The flexible encapsulating material includes an epoxy resin represented by a Formula (1), a curing agent, and a curing accelerator and optionally includes a coupling agent, wherein based on 100 parts by weight of a total usage amount of the epoxy resin (A), the curing agent (B), and the curing accelerator (C), a usage amount of the epoxy resin (A) is 85 parts by weight or more, and based on 100 parts by weight of the usage amount of the epoxy resin (A), a usage amount of the coupling agent (D) is 0 to 5 parts by weight.

##STR00001##

The present invention provides a thermally conductive material having excellent thermal conductivity. Furthermore, the present invention provides a device with a thermally conductive layer that has a thermally conductive layer containing the thermally conductive material and a composition for forming a thermally conductive material that is used for forming the thermally conductive material. The thermally conductive material according to an embodiment of the present invention contains a cured substance of a disk-like compound, which has one or more reactive functional groups selected from the group consisting of a hydroxyl group, a carboxylic acid group, a carboxylic acid anhydride group, an amino group, a cyanate ester group, and a thiol group, and a crosslinking compound which has a group reacting with the reactive functional groups.

The present invention discloses a halogen-free epoxy resin composition having low dielectric loss, comprises: (A) 100 parts by weight of an epoxy resin; (B) 10-30 parts by weight of a DOPO modified curing agent; (C) 1-10 parts by weight of benzoxazine resin; (D) 60-90 parts by weight of an active ester compound; (E) 20-50 parts by weight of a flame retardant; and (F) 0.5-10 parts by weight of a curing accelerator. The halogen-free epoxy resin composition uses active ester as a curing agent of the epoxy resin to ensure that the hardening product has characteristics such as low dielectric constant (Dk), low dielectric loss (Df), high heat resistance, low water absorption, flame retardant and halogen-free. The halogen-free epoxy resin composition of the present invention is used for manufacturing semi-cured prepregs or resin-coated films, and is applied toward manufacturing metal clad laminates and printed circuit boards.

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.