| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a perfluoropolyether oil improved in thermal oxidation resistance in the presence of a metal, while substantially keeping a combination of rheological characteristics of a high viscosity index and a low fluid point brought about by an oil having formula (A): R<SB>f</SB>O(C<SB>2</SB>F<SB>4</SB>O)<SB>p</SB>(CF<SB>2</SB>O)<SB>q</SB>R<SB>f'</SB>. <P>SOLUTION: A linear perfluoropolyether is expressed by formula (I): T-O(CF<SB>2</SB>O)<SB>n</SB>(CF<SB>2</SB>CF<SB>2</SB>O)<SB>m</SB>(CF<SB>2</SB>CF<SB>2</SB>CF<SB>2</SB>O)<SB>r</SB>(CF<SB>2</SB>CF<SB>2</SB>CF<SB>2</SB>CF<SB>2</SB>O)<SB>s</SB>-T<SB>1</SB>[m, n, r, and s are each such an integer as satisfying that a number-average molecular weight of the perfluoropolyether is in a range of 700 to 100,000 and that a ratio of n/(n+m+r+s) is in a range of 0.05 to 0.40]. A method for producing the perfluoropolyether expressed by formula (I) comprises adding a peroxidized perfluoropolyether having a PO of 1.8-4 and expressed by formula (III): T<SB>4</SB>-O(CF<SB>2</SB>O)<SB>n'</SB>(CF<SB>2</SB>CF<SB>2</SB>O)<SB>m'</SB>(O)<SB>h</SB>-T<SB>5</SB>to the perfluoropolyether oil which is preliminarily heated at a temperature between 150°C and 250°C, and then thoroughly fluorinating a compound obtained in the above reaction. <P>COPYRIGHT: (C)2004,JPO&NCIPI</p> |
