US Patent 7704900 Artificial leather sheets and method for producing them

Provided is an artificial leather sheet that comprises microfine fibers of an inelastic polymer having a mean fiber diameter of at most 5 μm and an elastic polymer, in which the major portion of the elastic polymer forms a fibrous structure of the entangled nonwoven fabric with the microfine fibers of inelastic polymer throughout the entire layer of the artificial leather sheet in the thickness direction thereof, and a part of the elastic polymer forms a porous layer integrated with the entangled nonwoven fabric structure on at least one face of the artificial leather sheet. The artificial leather sheet does not substantially undergo structure deformation even when repeatedly elongated and deformed. It has good elastic stretchability, and has a soft and dense feel, and its appearance is good not detracting from the drapability of the sheet.