| 摘要 |
PROBLEM TO BE SOLVED: To provide a fluorine-based magnetic fluid used to enhance the affinity between magnetic fine particles and perfluoropolyether base oil and effectively used as a sealing material for vacuum apparatus. SOLUTION: (A) Micro magnetic particulates are dispersed in (D) perfluoropolyether base oil expressed by a general formula F[CF(CF3 )CF2 O]mRf using (B) perfluoroether(poly)alkylene ether carboxylic acid (salt) expressed by a general formula F[CF(CF3 )CF2 O]n CF (CF3 )s CH2 COOM (R: lower alkylene group, X :-COO- group, -CH2 O group-, n, s: 1 to 100) and perfluoroether carboxylic acid amid compound expressed by a general formula F[CF(CF3 )CF2 O]p CF (CF3 )CONH(CH2 )q NH2 , F[CF(CF3 )CF2 O]p CF (CF3 )CONH(CH2 CH2 NH)r H or F[CF(CF3 )CF2 O]p CF (CF3 )CONH(CH2 CH2 NH)r COCF (CF3 )[OCF2 CF(CF3 )]p F. |
