Abstract: A photo-curable epoxy resin type composition which comprises (a) an epoxy resin, (b) at least one compound selected from the group consisting of (i) a compound having a group, other than an imido group, which is represented by the formula --CONH and (ii) an aromatic amine, (c) an organic metal compound, where said metal is selected from the group consisting of titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, aluminum and zirconium; and (d) an organic silicon compound having at least one group selected from the group consisting of a peroxysilyl group and an o-nitrobenzyloxy group capable of forming a silanol group by irradiation with light. The photo-curable epoxy resin type composition according to this invention is capable of readily curing by light (ultraviolet ray in particular) and also capable of heat curing at a temperature of 150.degree. C.

Abstract: An ultrasonic coupling agent of low viscosity which comprises at least one aqueous solution selected from an aqueous ethyl alcohol solution and an aqueous glycerin solution, and 75 to 0.1% by weight based on the total weight of the agent of silicone-based oil which is substantially soluble in the aqueous solution. The ethyl alcohol solution is preferably included in the ultrasonic coupling agent in an amount sufficient to invest the agent with a disinfection effect.

Abstract: A photopolymerizable epoxy resin composition comprising (a) an epoxy resin and (b) a heteropoly-acid aromatic sulfonium salt or a heteropoly-acid aromatic iodonium salt as a photocuring catalyst exhibits rapid photopolymerization, with the cured product being great in hardness, the corrosive action being weak, and the electrical properties being excellent. The industrial utility of the composition is therefore substantial.

Abstract: A photocurable composition comprising (1) an epoxy compound having at least one epoxy group and at least one unsaturated double bond in the same molecule; (2) a metal compound present in an amount ranging from 0.001 to 10 wt. %, based on the epoxy compound; and (3) a silicon compound which is capable of forming a silanol group when irradiated with light and which is present in an amount ranging from 0.1 to 20 wt. %, based on the epoxy compound, is characterized by a particularly rapid curing rate.

Abstract: Disclosed are photocurable compositions which comprise(A) a compound having at least one epoxy group and at least one photocurable unsaturated ethylenic double bond within the same molecule;(B) an organometallic compound and(C) a silicon compound capable of generating silanol group by irradiation of light, or comprise(A) a compound having at least one epoxy group and at least one photocurable unsaturated ethylenic double bond within the same molecule;(E) an epoxy compound;(F) an organic phosphorus compound; and(G) a photosensitizer.The compositions of the present invention have excellent film characteristics such as good adhesion property, light resistance, heat resistance and weathering resistance.

Abstract: There is disclosed a photo-curable epoxy resin type composition comprising an epoxy resin, an aluminum compound, a silicon compound having a peroxysilyl group and a photosensitizer.The compositions of the present invention can suitably be used for wide varieties of electrical applications.

Abstract: There is disclosed a resin composition comprising(A) a spiro ortho ester compound and/or a spiro ortho carbonate compound;(B) an aluminum compound; and(C) a silanol compound or a silicon compound which is capable of generating a silanol group;the amounts of components (B) and (C) being within the range of 0.001 to 10% by weight and 0.1 to 20% by weiht, based on the amount of component (A), respectively.The resin composition of this invention is excellent in volumetric shrinkage performance at curing operation and is good in storability. Therefore, the cured product can be used for a wide variety of industrially valuable applications, such as an ink, a coating, an adhesive, a surface coating, an encapsulation and an electrical insulating material.

Abstract: Disclosed is a magnetic recording medium, characterized in that 5 to 100 parts by weight of hexagonal ferrite particles having an average particle diameter of 0.01 to 0.2 .mu.m and 100 parts by weight of ferromagnetic particles having a saturation magnetization of 72 to 220 emu/g and an average particle diameter larger than that of the hexagonal ferrite particles are dispersed in a resinous binder.

Abstract: Disclosed is a magnetic recording medium comprising substrate and a resinous composition containing magnetic particles of uniaxially-anisotropic hexagonal crystals having particle diameters of 0.01.about.0.3 .mu.m and coated on said substrate; the ratio of remanent magnetization to saturation magnetization on the magnetization curve corrected to demagnetizing field which is measured in a direction vertical to the surface of the recording medium, ranging from 0.3 to 0.7. This magnetic recording medium requires no orientation treatment for its production.

Abstract: An epoxy resin-based compositions contain epoxy resins and a catalytic amount of curing catalysts which comprise organosilicon compounds having at least one hydroxyl group directly bonded to silicon atom and a compound having organic groups of aluminum, iron or vanadium.

Abstract: An epoxy resin-based composition contains epoxy resins and a catalytic amount of latent curing catalysts which comprise organosilicon compounds having hydrolyzable groups and aluminum compound having organic groups.

Abstract: A thermosetting resin composition containing as essential resin components (a) a maleimide compound modified with furfuryl alcohol, (b) an epoxy resin and (c) a polyvinyl formal, and a latent curing agent or a curing accelerator which is at least one compound selected from the group consisting of dicyandiamide, boron trifluoride-amine complexes, metal chelate compounds, and silicone compounds and organo-silane compounds having at least one hydroxyl group bonded directly to silicon atom, is found to be capable of B-staging with good storage stability and provides a heat-resistant resin composition having excellent electric characteristics at high temperatures after curing. The composition can suitably be coated on a glass cloth or a mica tape to give a pre-preg tape which can maintain its flexibility for a long time.

Abstract: A semiconductor device sealed in a resin composition, wherein the resin composition contains the prescribed percentages of inorganic fillers having extremely small amounts of impurities, epoxy resin having an epoxy equivalent of 250 or less and a softening point of 120.degree. C. or less, hardening agent, hardening promoter and low melting paraffins.

Abstract: A heat-resistant resin composition having for its essential components (A) at least one maleimide compound obtained by reacting a condensation product of aniline, a phenolic compound and formaldehyde with an acid anhydride reactant containing at least 40 mole percent of maleic anhydride and (B) at least one compound selected from the group consisting of polyallyl phenyl ether compounds and polyallylphenolic compounds each having at least two allyl radicals.

Abstract: Resin compositions comprising maleimide compounds obtained by reacting maleic anhydride with mixed polyamines produced by reaction between aniline and formaldehyde; diallylbisphenol compounds; and epoxy resins. The compositions display prominent heat resistance when hardened.

Abstract: An unsaturated polyester resin composition comprises a mixture of a particular unsaturated polyester, an unsaturated monomer copolymerizable with the unsaturated polyester and polystyrene having a certain particle size in specific amounts. The unsaturated polyester is a reaction product of a dicarboxylic acid component containing .alpha.,.beta.-unsaturated dicarboxylic acid with a glycol component containing certain amounts of neopentyl glycol and 2,2-bis(4-hydroxycyclohexyl) propane. The resin composition exhibits favorable properties such as low shrinkage upon curing, good colorability and good storage stability, and is useful particularly in formulating premixed molding compounds.