Layered resin molding and multilayered molded article

A production method of a multilayer molded article having an at least two-layer structure comprising

• a layer (A) formed by melt extrusion of a polyamide-based resin composition having a functional group, in addition to an amide group, selected from the group consisting of hydroxyl group, carboxyl group, ester group and sulfonamide group in a total amount of 0.05 to 80 equivalent percent relative to the amide group, and
• a layer (B) formed by melt extrusion of a fluorine-containing ethylenic polymer having 3 to 1,000 carbonyl groups, in total, per 1×106 main chain carbon atoms and laminated to said layer (A),
• which comprises molding a resin laminate having said layer (A) and said layer (B) by melt extrusion to form a multilayer molding and subjecting the thus-formed multilayer molding to heat treatment for 0.01 to 10 hours at a temperature lower than the lowest melting point among melting points of the resins constituting said molding to obtain the multilayer molded article.

A method of reducing permeability, against a liquid agent, of a laminated resin molding comprising a layer (I) and a layer (II) laminated to said layer (I),

• which comprises incorporating, in said layer (I), a compound having high affinity for said liquid agent and capable of being prevented, by said layer (II), from migrating to said liquid agent,
• said layer (I) comprising a polyamide-based resin composition, and
• said layer (II) comprising a fluorine-containing ethylenic polymer.

A production method of a laminated resin molding having low liquid agent permeability and comprising a layer (I) and a layer (II) laminated to said layer (I),

• which comprises incorporating, in a polyamide-based resin composition constituting said layer (I), a compound having high affinity for said liquid agent and capable of being prevented, by said layer (II), from migrating to said liquid agent and subjecting the resulting composition to lamination,
• said layer (I) comprising the polyamide-based resin composition, and
• said layer (II) comprising a fluorine-containing ethylenic polymer.