Abstract: The retardation film according to the present invention is characterized by: including a polymer material that includes at least one cellulose derivative which includes specific monomer units: having an in-plane retardation Re(550) of 105-160 nm, reverse wavelength dispersion property, Re(450)/Re(550), of 0.80-0.89, and a thickness of 20-50 ?m; and containing inorganic particles. In particular, the present invention exhibits the effect of reducing the photoelastic coefficient.

Abstract: The present invention has its object to provide a resin composition excellent in gas barrier properties, mechanical strength and elasticity and further showing only a slight extent of gravity deformation under high temperature conditions. The invention relates to a resin composition which comprises an isobutylene-based polymer (A), an isobutylene-based block copolymer (B) comprising a polymer block (b1) the constituent monomer(s) of which is(are) an aromatic vinyl compound(s) and a polymer block (b2) the constituent monomer(s) of which is(are) isobutylene, and a filler (C). This composition can be used as a sealant, in particular as a hot melt sealant for double glazing units, and as a hot melt spacer material for double glazing units.