Provided is a polysulfide-based sealant that allows to obtain a highly reliable molded product (cured material) with reduced formation and growth of air bubbles. A sealant sheet formed in a sheet shape is provided. The sealant sheet comprises a polysulfide polymer (A), a thiol compound (B) having two or more thiol groups per molecule, an allyl compound (C) having two or more allyl groups per molecule, and a photo-radical generator (D).

A dual-curable sealant composition includes a polysulfide having an SH group, a metal oxide catalyst, and an alkyl-borane amine catalyst. A cured sealant is also formed from the dual-curable sealant composition. Moreover, a dual-cured sealant is formed that includes the polymerization product of the polysulfide reacted in the presence of the metal oxide catalyst and the alkylborane amine catalyst. Further, a dual-curable sealant system includes a first component including the polysulfide and the alkylborane amine catalyst and a second component including the metal oxide catalyst. An article is formed that includes a substrate and the cured sealant disposed on the substrate. Even further, a method of forming the dual-curable sealant composition includes the steps of providing the polysulfide, the alkylborane amine catalyst, and the metal oxide catalyst, and combining the polysulfide, the alkylborane amine catalyst, and the metal oxide catalyst to form the dual-curable composition.

The resin composition for molding includes: a sulfur atom-containing epoxy resin; a curing agent; a release agent; an inorganic filler; and a copolymer of a C5-30 -olefin and at least one of maleic anhydride and a maleic anhydride derivative.