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: The photosensitive composite of the present invention is obtained by including a nonsubstitutional or substitutional benzyl radical in the phenol side chain of polyvinylphenol. The photosensitive composites have not only excellent heat resistivity, RIE resistivity, and resolving power but also have a wide tolerance for the variations in the development temperature and developer concentration at the time of development. Therefore, it is possible to obtain resist patterns with fine structure.

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 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: There is disclosed a photo-curable epoxy resin composition comprising an epoxy resin and a combination of an organic aluminum compound and a silicon compound having an o-nitrobenzyloxy group as a catalyst.The compositions of the present invention are suitable for electrical uses in electrical application.

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

Abstract: Disclosed is a photocurable silicon compound composition which comprises a silicon compound having a silicon atom to which directly bonded is an o-nitrobenzyloxy group represented by the following formula: ##STR1## wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 may be same or different and each represents a hydrogen atom, a halogen atom, a nitro group, a cyano group, a substituted or unsubstituted alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, a substituted or unsubstituted aryl group, an aryloxy group, an acyloxy group having 1 to 5 carbon atoms, a hydroxy group, a mercapto group, an acetyl group or an allyl group,and optionally a silanol-condensing catalyst.

Abstract: A photopolymerizable composition based on an epoxy compound contains as a curing catalyst a combination of an .alpha.-ketosilyl compound with an aluminum compound having at least one organic radical directly bonded to the aluminum atom, and further contains as a photosensitizer a benzophenone compound and/or a thioxanthone compound.

Abstract: An electrically insulated coil is composed of a coil and a mica tape containing a first resinous composition, wound upon the coil; the resinous composition containing a maleimide compound, an epoxy resin, a curing catalyst consisting of an aluminum compound, and a curing accelerator selected from the group consisting of a silane compound having a hydroxyl group and a polysiloxane compound having a hydroxyl group; the curing catalyst and the curing accelerator each being in an amount of about 0.0001 to 5% by weight based on the total amount of the maleimide compound and the epoxy resin; and the resinous composition being cured by heating after the mica tape is wound around the coil.The electrically insulated coil may further contain a second resinous composition comprising an epoxy resin and an acid anhydride, the second resinous composition impregnating the mica tape after the mica tape is wound around the coil, and being heat-cured together with the first resinous composition.

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.