The purpose of the present invention is to provide: a novel curable compound which can be expected to be used as a raw material for photocurable resins and thermosetting resins; a method for synthesizing said compound; a resin composition containing said compound; and a cured product thereof. This compound is an epoxy-oxetane compound represented by a formula, and this compound has a structure in which two epoxycyclohexyl groups (groups in which an oxirane ring and a cyclohexane ring are condensed) are bonded to an oxetane ring via a connector having one ether bond. In formula (I), R.sub.1 to R.sub.3 may be the same as, or different from, each other, and each denote a hydrogen atom or a methyl group. n is 1 or 2. ##STR00001##

A group of polyfunctional oxetane-based compounds having a structure as represented by general formula (I) or a product obtained by a reaction between a compound of general formula (I) and epichlorohydrin, an ester compound, or an isocyanate compound. When these polyfunctional oxetane-based compounds are used as cation polymerizable monomers in combination with an epoxy compound, the curing speed is high, and the cured product has highly excellent hardness, flexibility, adherence, and heat resistance.

A group of polyfunctional oxetane-based compounds having a structure as represented by general formula (I) or a product obtained by a reaction between a compound of general formula (I) and epichlorohydrin, an ester compound, or an isocyanate compound. When these polyfunctional oxetane-based compounds are used as cation polymerizable monomers in combination with an epoxy compound, the curing speed is high, and the cured product has highly excellent hardness, flexibility, adherence, and heat resistance.

A cationic curable composition that generates a silanol group by light irradiation and is cured by heat, the cationic curable composition including: a cationic curable component; porous particles holding an aluminum chelate; and a photodegradable silicon compound that generates a silanol group by photodegradation.

A cured product of a resin composition according to the present invention includes at least silsesquioxane. When the average thermal expansion coefficient of the cured product at 30 to 200 C. is expressed as 1 [K.sup.1], at least one of requirements 1/210 and (12).sup.210.sup.80.4 is satisfied, where a reference value 2 is 35010.sup.6 [K.sup.1] or less. In the cured product, an absorbance derived from a siloxane bond, an absorbance derived from a hydrocarbon group, and an absorbance derived from a hydroxy group are respectively expressed as Ia, Ib, and Ic, the absorbances being determined by attenuated total reflection using a Fourier transform infrared spectrophotometer. In this case, requirements 0.09Ia/Ib3.0 and 0.04Ic/Ib1.0 are satisfied.

A cured product of a resin composition according to the present invention includes at least silsesquioxane. When the average thermal expansion coefficient of the cured product at 30 to 200 C. is expressed as 1 [K.sup.1], at least one of requirements 1/210 and (12).sup.210.sup.80.4 is satisfied, where a reference value 2 is 35010.sup.6 [K.sup.1] or less. In the cured product, an absorbance derived from a siloxane bond, an absorbance derived from a hydrocarbon group, and an absorbance derived from a hydroxy group are respectively expressed as Ia, Ib, and Ic, the absorbances being determined by attenuated total reflection using a Fourier transform infrared spectrophotometer. In this case, requirements 0.09Ia/Ib3.0 and 0.04Ic/Ib1.0 are satisfied.

This invention provides hollow particles having a shell containing at least one layer and having an average particle diameter of 10 to 150 nm, wherein a ratio between absorbance at 908 cm.sup.1 (A908) and absorbance at 1722 cm.sup.1 (A1722) in an infrared absorption spectrum obtained by measuring the hollow particles by ATR-FTIR (absorbance ratio : A908/A1722) is 0.1 or less.

Provided is a monomer composition that has rapid curability and can be cured rapidly, even in the presence of oxygen and/or water, to form a cured product having excellent adhesion to a wide variety of substrates. The monomer composition according to the present invention contains a vinyl ether compound (A). The vinyl ether compound (A) includes a vinyl ether compound (a) having a cyclic ether skeleton. The monomer composition further contains at least one compound selected from the group consisting of a vinyl ether compound (a) having a chain hydrocarbon skeleton, a divinyl ether compound (a-1) having a cyclic hydrocarbon skeleton, an oxetane compound (B), and an epoxy compound (C).

Provided is a monomer composition that has rapid curability and can be cured rapidly, even in the presence of oxygen and/or water, to form a cured product having excellent adhesion to a wide variety of substrates. The monomer composition according to the present invention contains a vinyl ether compound (A). The vinyl ether compound (A) includes a vinyl ether compound (a) having a cyclic ether skeleton. The monomer composition further contains at least one compound selected from the group consisting of a vinyl ether compound (a) having a chain hydrocarbon skeleton, a divinyl ether compound (a-1) having a cyclic hydrocarbon skeleton, an oxetane compound (B), and an epoxy compound (C).

The present invention provides a monomer mixture that rapidly cures even in high humidity environments, and is useful as a raw material for a curable composition that forms a cured product having excellent adhesion to metals and glass, as well as of course to paper and plastic.

The monomer mixture according to an embodiment of the present invention contains two or more types of cationically polymerizable monomers. The monomer mixture contains, as the cationically polymerizable monomers, a compound (A) having a vinyl ether group and a hydroxyl group; a compound (B) having an oxetanyl group and a hydroxyl group; and a compound (C) represented by Formula (c) below. A total content of the compound (A), the compound (B), and the compound (C) is 50 wt. % or greater of the total amount of the monomer mixture, and a content [A] of the compound (A) and a content [B] of the compound (B) satisfy Relationship (1) below.

A/(A+B)0.3(1)

##STR00001##