Porous hollow-fiber membrane and production process therefor

A porous hollow-fiber membrane comprising a fluororesin-based polymer, wherein

• the porous hollow-fiber membrane has a columnar texture oriented in a longitudinal direction thereof,
• a molecular chain in the columnar texture is oriented in the longitudinal direction of the porous hollow-fiber membrane, and
• the molecular chain has an average value v of a Raman orientation parameter being from 1.5 to 4.0:
• Raman orientation parameter =(I1270/I840) parallel/(I1270/I840) perpendicular (1),
• wherein
• parallel condition:
• the longitudinal direction of the porous hollow-fiber membrane is parallel to a polarization direction;
• perpendicular condition:
• the longitudinal direction of the porous hollow-fiber membrane is orthogonal to the polarization direction;
• I1270 parallel:
• the intensity of Raman band at 1,270 cm−1 under the parallel condition;
• I1270 perpendicular:
• the intensity of Raman band at 1,270 cm−1 under the perpendicular condition;
• I840 parallel:
• the intensity of Raman band at 840 cm−1 under the parallel condition;
• and
• I840 perpendicular:
• the intensity of Raman band at 840 cm−1 under the perpendicular condition.