Abstract: A composition with improved storage viscosity is provided. The composition contains a (meth)acrylic-based copolymer (A?) and an epoxy compound (C). A molecule of the (meth)acrylic-based copolymer (A?) includes an XY diblock structure or an XYX triblock structure therein. A number of repeating units which are derived from a (meth)acrylic ester monomer having an alkoxysilyl group and are included in an X block is 1.0 or more on average; an amount of repeating units which are derived from a (meth)acrylic ester monomer having an alkoxysilyl group and are included in a Y block is 0% by weight to 3% by weight, with respect to a weight of all repeating units included in the Y block. A molecular weight distribution (Mw/Mn) of the (meth)acrylic-based copolymer (A?) is 1.8 or less.

Abstract: The invention has its object to provide a curable composition having improved compatibility of a high-molecular-weight polyether polymer and a vinyl polymer and excellent in mechanical properties. The invention uses a curable composition which comprises a polyether polymer (I) having at least one crosslinkable functional group and a number average molecular weight of 10,000 or higher, and a vinyl polymer (II) having at least one crosslinkable functional group at a polymer terminus and compatible with the polyether polymer (I). As the vinyl polymer (II), a poly(n-butyl acrylate/ethyl acrylate/octadecyl acrylate) copolymer may be mentioned, for example.

Abstract: A composition comprising a vinyl polymer having a crosslinkable silyl group may suffer from a delay in curing after the storage. The present invention relates to the following items. A curable composition comprising, as an essential component, (I) a vinyl polymer, which has at least one crosslinkable silyl group at the terminus and also has a monomer containing a methyl ester group as a constituent unit. A sealant, a liquid gasket, and an adhesive, wherein the above curable composition is used. A polymer has at least one crosslinkable functional group at the terminus and also has a vinyl polymer as a main chain thereof, wherein 2% to 80% by weight of monomers based on the total monomers constituting the main chain is methyl acrylate. A curable composition with improved storage stability, which comprises the following two components as essential components: (a) a vinyl polymer having at least one crosslinkable silyl group; and (b) a compound having a methyl ester group other than the compound (a).