Method of manufacturing highly-airtightened porous paper, highly-airtightened porous paper manufactured by the method, and non-aqueous battery using the paper

Abstract

Paper that has minute pores, denseness, a high degree of airtightness and is made from cellulose which has superior heat and chemical resistance and is reproducible natural resources. Further, a non-aqueous battery which is improved to a higher level with regards to various characteristics, e.g., heat resistance, electrical characteristics such as ion transmissivity or liquid-holding characteristics, or prevention of an internal short circuit, through use of, as a separator for electronically separating a positively active substance from a negatively active substance, a novel porous highly-airtightened separator which is made from cellulose and has pores and denseness. The separator is manufactured from highly-airtightened porous paper having minute pores made by forming wet paper web from minute cellulose having a fiber diameter of 1 &mgr;m or less, and drying the wet paper web while voids in the wet paper web are maintained. The separator is used in a non-aqueous battery or electrolytic capacitor. More specifically, cellulose whose fibers are beaten to a JIS-CSF value of 200 ml or less (where the JIS-CSF value is measured in accordance with JIS P8121) or cellulose whose fibers are beaten to a value of 700 ml or less measured by modified CSF (wherein 3 g of a sample is measured as 0.3 g of a sample by the method specified in JIS P8121) is used as the minute cellulose.