BACK SHEET FOR PAPER DIAPER

摘要

PURPOSE: To obtain a back sheet for a paper diaper excellent in moisture permeability and having deodorizing action by using a film composed of a specific polyester elastomer having an aromatic polyester unit as a hard segment and a poly(alkylene oxide) glycol unit as a soft segment. CONSTITUTION: A back sheet for a paper diaper is composed of a film of a polyester elastomer having an aromatic polyester unit as a hard segment and a poly(alkylene oxide) glycol unit as a soft segment and satisfying formula 0<(1/d)(1000/F-b)<=0.0125 (wherein b is 0<=b<=0.15). In the formula, d is the thickness (μm) of the film, F is the moisture permeability (g/m<2> .24hr) of the film and b is the permeation constant (m<2> .24hr/g) of the film. The polyester elastomer is obtained by the polycondensation of an aromatic dicarboxylic acid, an alkylene glycol and a poly(alkylene oxide) glycol. This film is excellent in moisture permeability and deodorizing effect.