An electrical device includes at least one cross-linked layer obtained from a polymer composition that has: at least one polymer comprising one or more epoxy function(s), and at least one cross-linking agent. The cross-linking agent is selected from: a non-aromatic cyclic amine, an imidazole of formula (I)

##STR00001##

where R.sub.1 and R.sub.2 independently represent a hydrogen atom or a hydrocarbon group, R.sub.3 and R.sub.4 independently represent a hydrogen atom or a hydrocarbon group, or R.sub.3 and R.sub.4 form, together with the carbon atoms of the imidazole ring to which they are attached, a ring, with the imidazole being associated with a cross-linking co-agent having at least one reactive function capable of reacting with the epoxy function of said polymer, and, a mixture thereof.

A curable composition comprises a) at least one epoxide compound E having at least two epoxide groups; b) at least one amine A having at least two amine hydrogens; and c) at least one acrylic ester U; wherein the epoxide compound E comprises at least one epoxide compound E, the amine A comprises at least one amine A, and the acrylic ester U comprises at least one acrylic ester U whose Hansen solubility parameters for the dipole forces .sub.p and for the specific interactions .sub.h satisfy the following conditions: $\sqrt{{\left({}_{p\left(U^{}\right)}-{}_{p\left(E^{}\right)}\right)}^2+{\left({}_{h\left(U^{}\right)}-{}_{h\left(E^{}\right)}\right)}^2}1.5$

A curable composition comprises a) at least one epoxide compound E having at least two epoxide groups; b) at least one amine A having at least two amine hydrogens; and c) at least one acrylic ester U; wherein the epoxide compound E comprises at least one epoxide compound E, the amine A comprises at least one amine A, and the acrylic ester U comprises at least one acrylic ester U whose Hansen solubility parameters for the dipole forces .sub.p and for the specific interactions .sub.h satisfy the following conditions: $\sqrt{{\left({}_{p\left(U^{}\right)}-{}_{p\left(E^{}\right)}\right)}^2+{\left({}_{h\left(U^{}\right)}-{}_{h\left(E^{}\right)}\right)}^2}1.5$

An epoxy-functionalized polyorganosiloxane toughener providing toughening properties for thermosetting resins is described. The epoxy-functionalized polyorganosiloxane toughener is an epoxy-functionalized siloxane polyether with a siloxane backbone, at least one epoxy-containing alkyl chain, and at least one alkoxyl polyether chain, each said at least one epoxy-containing alkyl chain and at least one alkoxyl polyether chain grafted to the siloxane backbone. Also disclosed is a thermosetting resin-based composition comprising the epoxy-functionalized polyorganosiloxane toughener of claim 1 and at least one of an epoxy resin, a hardener, and an accelerator.

An insulating heat dissipation coating composition including a coating layer-forming component including a subject resin, and an insulating heat dissipation filler. Therefore, the coating composition may have excellent thermal conductivity and excellent thermal emissivity, and therefore an insulating heat dissipation coating layer which exhibits excellent heat dissipation performance and has insulating property may be formed. In addition, the heat dissipation coating layer formed thereby has a very excellent adhesive strength to a surface to be coated so as to significantly prevent peeling of the coating layer during use, and to maintain durability of the coating layer even against a physical or chemical stimulus such as external heat, organic solvent, moisture or shock, which is generated after the coating layer is formed.

A resin composition for a printed circuit board includes an epoxy resin; an active ester hardening agent configured to react with the epoxy resin; and a cyanate ester hardening agent.

A resin composition for a printed circuit board includes an epoxy resin; an active ester hardening agent configured to react with the epoxy resin; and a cyanate ester hardening agent.

Provided is a resin composition that has satisfactory impregnability into reinforcing fibers due to low viscosity and small viscosity increase even in an impregnation process performed for a long time. The resin composition being suitable as a matrix resin for a fiber-reinforced composite material for producing a cured molded article that has toughness and fatigue resistance. The resin composition for a fiber-reinforced composite material includes an epoxy resin, an acid anhydride-based curing agent, an imidazole-based curing accelerator, a radically polymerizable monomer, and a radical polymerization initiator as essential components, has a viscosity at 25 C. that falls within a range of 50 mPa.Math.s to 800 mPa.Math.s as measured by an E-type viscometer, and exhibits a viscosity increase ratio of 200% or less after 8 h at 25 C., wherein 50% by mass or more of the acid anhydride-based curing agent is an alicyclic acid anhydride having no olefinic unsaturated bond.

Provided is a resin composition that has satisfactory impregnability into reinforcing fibers due to low viscosity and small viscosity increase even in an impregnation process performed for a long time. The resin composition being suitable as a matrix resin for a fiber-reinforced composite material for producing a cured molded article that has toughness and fatigue resistance. The resin composition for a fiber-reinforced composite material includes an epoxy resin, an acid anhydride-based curing agent, an imidazole-based curing accelerator, a radically polymerizable monomer, and a radical polymerization initiator as essential components, has a viscosity at 25 C. that falls within a range of 50 mPa.Math.s to 800 mPa.Math.s as measured by an E-type viscometer, and exhibits a viscosity increase ratio of 200% or less after 8 h at 25 C., wherein 50% by mass or more of the acid anhydride-based curing agent is an alicyclic acid anhydride having no olefinic unsaturated bond.

A curing agent composition comprising anhydride and approximately equimolar amount of tertiary amine or imidazole and carboxylic acid, the amine being 1-piperidinylethanol (N-hydroxyethyl-piperidine, NHEP) represented by the structure below or an imidazole represented by the structure below:

##STR00001##

where R.sub.1=H, a C1-C20 straight chain or branched alkyl, or a monocyclic aryl; R.sub.2=a C1-C20 straight chain or branched alkyl, or a monocyclic aryl. The carboxylic acid is represented by RCOOH; R=a C1-C20 straight chain or branched alkyl, or a monocyclic aryl. The composition comprises a lower ratio of epoxy resin to anhydride (1:0.4-0.6) than typically used (1:0.8-1.1). In addition, it uses a higher loading of the hindered latent tertiary amine or the imidazole in combination with the carboxylic acid (wt % ratio of combined amine and carboxylic acid to anhydride 10%). With this composition a full cure can be achieved in less than 2 hr at a significantly lower temperature (100 C.).