Abstract: A hollow fiber membrane of a cellulose ester for dialysis of body liquids, such as blood, and a method are described. The membrane, which has a membrane thickness of less than 20.mu., and a yield strength S.sub.b (g/filament) after heat-treatment at 80.degree. C. for 20 hours satisfies the following formula (I):0.90.ltoreq.S.sub.b /S.sub.a .ltoreq.1.10 (I)wherein S.sub.a represents the yield strength (g/filament) of the hollow fiber membrane which is measured before heat treatment. The membrane has excellent dialysis performance while keeping excellent storage stability and excellent UFR retention during storage and during hemodialysis. A spinning solution of a cellulose ester is extruded through cyclic slits around an inner tube of a spinneret while a core solution is simultaneously extruded through the inner tube of the spinneret.

Abstract: A hollow fiber membrane of a cellulose ester for dialysis which has a membrane thickness of less than 20.mu., and a yield strength S.sub.b (g/filament) after heat-treatment at 80.degree. C. for 20 hours satisfying the following formula (I):0.90.ltoreq.S.sub.b /S.sub.a .ltoreq.1.10 (I)wherein S.sub.a represents the yield strength (g/filament) of the hollow fiber membrane which is measured before heat treatment, which is suitable for dialysis of body liquids, particularly for dialysis of blood, because it has excellent dialysis performance while keeping excellent storage stability and excellent UFR retention during storage and during the hemodialysis.

Abstract: A photosensitive resin composition which comprises a polyester having a nitrogen atom in the ammonium salt form in the main or side chain representable by the formula: ##STR1## wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are each a hydrogen atom or a substituted or unsubstituted hydrocarbon group, at least one of R.sub.1 to R.sub.4 representing a polymeric chain, and X is an anion to be paired with the ammonium ion, a photopolymerizable unsaturated monomer and a photosensitizer.