POLYOLEFIN MICROPOROUS FILM, SEPARATOR FOR BATTERY AND SECONDARY BATTERY

• Main Authors: NAKAJIMA RYUTA, OKURA MASATOSHI, TOYODA NAOKI, SAKAMOTO MITSUTAKA, KUMAN TAKUYA
• Format: Patent
• Language: English; Japanese
• Published: 07.10.2022
• Subjects: AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F,C08G; BASIC ELECTRIC ELEMENTS; CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES ORLIGHT-SENSITIVE DEVICES, OF THE ELECTROLYTIC TYPE; CHEMISTRY; COMPOSITIONS BASED THEREON; ELECTRICITY; GENERAL PROCESSES OF COMPOUNDING; METALLURGY; ORGANIC MACROMOLECULAR COMPOUNDS; PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSIONOF CHEMICAL INTO ELECTRICAL ENERGY; THEIR PREPARATION OR CHEMICAL WORKING-UP; WORKING-UP

To provide a polyolefin microporous film having both mechanical strength and shutdown temperature by restraining a change of orientation at room and high temperatures, and to provide a separator for battery using the microporous film.SOLUTION: There is disclosed, a polyolefin microporous film characterized in that either one of orientation parameter values (fMH) and (fTH) measured at 130°C in MD and TD directions, calculated bybelow-mentioned formulae (1) and (2) using a Raman spectrum device, is larger than 1.5 and the other is 1.5 or less. Formula (1) is fMH=Ia(MD,130°C)/Ib(MD,130°C) and formula (2) is fTH=Ia(TD,130°C)/Ib(TD,130°C) (herein, Ia is maximum mechanical strength of Raman band in 1100-1170 cm-1; Ib is maximum strength of the above band in 1040-1090 cm-1; Ia(MD,130°C) and Ib(MD,130°C) are maximum strengths at 130°C in the MD direction; and Ia(TD,130°C) and Ib(TD,130°C) are maximum strengths at 130°C in the TD direction).SELECTED DRAWING: None 【課題】室温と高温での配向変化抑制することで機械的強度およびシャットダウン温度を両立したポリオレフィン微多孔膜及び電池用セパレータを提供する。【解決手段】ラマン分光から下記（１）、（２）式により算出される１３０℃で測定したＭＤ方向の配向パラメータ値（ｆＭＨ）とＴＤ方向の配向パラメータ値（ｆＴＨ）のいずれか一方が１．５より大きく、もう一方が１．５以下であることを特徴とする。ｆＭＨ＝Ｉａ（ＭＤ、１３０℃）/Ｉｂ（ＭＤ、１３０℃）・・・（１）式ｆＴＨ＝Ｉａ（ＴＤ、１３０℃）/Ｉｂ（ＴＤ、１３０℃）・・・（２）式Iａは１１００～１１７０ｃｍ－１におけるラマンバンドの最大強度、Ｉｂは１０４０～１０９０ｃｍ－１におけるラマンバンドの最大強度、Ｉａ（ＭＤ、１３０℃）、Ｉｂ（ＭＤ、１３０℃）は１３０℃でのＭＤ方向の最大強度、Ｉａ（ＴＤ、１３０℃）、Ｉｂ（ＴＤ、１３０℃）は１３０℃でのＴＤ方向の最大強度。【選択図】なし