Aug. 2, 2007  24  US 2007/0179263 A  1  wherein X1, X 2 , X 3 , X 4 , X 5 , n3, D 2  and Ry 4  are as defined  in the formula (5), from the viewpoint of excellent homopo› lymerizability and copolymerizability with a fluorine-con› taining ethylenic monomer and also from the point that  oxidation resistance and heat resistance can be imparted  effectively to the obtained polymer.  [0198]  Examples of the aromatic compounds of the for› mula ( 6) are:  CH$_{2}$=CFCF$_{2}$-D $^{2}$-Ry4 ,  CF$_{2}$=CF-D $^{2}$-Ry4 ,  CF$_{2}$=CFCF$_{2}$-D $^{2}$-Ry4 ,  CH$_{2}$=CH-D $^{2}$-Ry4 ,  CH$_{2}$=CHCH$_{2}$-D $^{2}$-Ry4 ,  CH$_{2}$=CFCF$_{2}$0-D $^{2}$-Ry4 ,  CF$_{2}$=CFO-D $^{2}$-Ry4 ,  CF$_{2}$=CFCF$_{2}$0-D $^{2}$-Ry4 ,  CH$_{2}$=CHO-D $^{2}$-Ry4 ,  CH$_{2}$=CHCH$_{2}$0-D $^{2}$-Ry4  and the like, and particularly preferred are:  CH$_{2}$=CFCF$_{2}$-D $^{2}$-Ry4 ,  CF$_{2}$=CF-D $^{2}$-Ry4 ,  CH$_{2}$=CFCF$_{2}$0-D $^{2}$-Ry4 and  CF$_{2}$=CFO-D $^{2}$-Ry4  because polymerizability is high and oxidation resistance  and heat resistance can be effectively imparted to the poly› mer.  [0199]  Also preferred examples of the structure of the  whole aromatic compound of the formula (6) are the same  as those of (1-e), (1-f) and (1-g) among the classified  examples of the aromatic compound of the formula (1 ).  [0200]  The third of the present invention relates to a novel  fluorine-containing polymer which is included in the poly› mers of the formula (M-1) to be used in the ionic liquid type  functional material, and is one of the most preferred ionic  liquid type functional materials.  [0201]  The novel polymer of the present invention is the  fluorine-containing polymer which has a number average  molecular weight of from 500 to 1,000,000 and is repre› sented by the formula (M-3):  -(M3)-(A3)- (M-3)  wherein the structural unit M3 is a structural unit repre› sented by the formula (7):  (7)  wherein X 6 , X 7 , X 9  and X$^{10 }$are the same or different and  each is hydrogen atom or fluorine atom; X $^{8 }$is selected from  hydrogen atom, fluorine atom,  CH$_{3 }$ and  CF$_{3}$ ;  n3 and n4 are  the same or different and each is 0 or 1; D 2  and Ry 4  are as  defined in the formula (5); the structural unit A3 is a  structural unit derived from a monomer being copolymer› izable with the monomer being capable of providing the  structural unit M3, and the structural units M3 and A3 are  contained in amounts of from 1 to 100% by mole and from  0 to 99% by mole, respectively.  [0202]  The polymer of the formula (M-3) is a novel  polymer which is not disclosed in patent publications and  bulletins.  [0203]  The polymer of the formula (M-3) of the present  invention is obtained by polymerizing the aromatic com› pound of the formula (5) having an ethylenic double bond,  and may be a homopolymer containing only the structural  unit M3 or may be a copolymer of the monomer of the  formula (5) being capable of providing M3 and a copoly› merizable monomer.  [0204]  Examples of the structural unit M3 in the polymer  of the formula (M-3) are:  and the like, and particularly preferred as the structural unit  M3 are structural units represented by the formula (8):  (8)  -(CH2CF)› I  CF2-D 2 -Ry4,  -(CF2CF)- -(CF2CF)- I  D 2 -Ry4,  -(CH2CH)- I  I  CF2-D 2 -Ry4,  CH2-D 2 -Ry 4 ,  -(CH2CH)- -(CH2CF)- I  I  D 2 -Ry4,  CF20-D 2 -Ry4,  -(CF2CF)- -(CF2CF)- I  I  O-D 2 -Ry4,  CF20-D 2 -Ry4,  -(CH2CH)- -(CH2CH)- I  I  CF20-D 2 -Ry4,  O-D 2 -Ry4,  -(CF2CF)- -(CF2CF)- I  I  CF2CF2-D 2 -Ry4,  CH2-D 2 -Ry4,  -(CH2CH)- -(CH2CF)- I  I  CF2-D 2 -Ry4,  CO-D 2 -Ry4,  -(CH2CH)- I  co-D 2 -Ry4,  II  0  -(CH2CF)- I  TI-D2-Ry4,  0  CH3  I  -(CH2C)-- I  C-D 2 -Ry4,  II  0  CF3  I  -(CH2C)-- I  C-D $^{2}$-Ry4  II  0  II  0  CH3  I  -(CH2C)-- I  co-D 2 -Ry4,  II  0  -(CH2CH)- I  TI-D2-Ry4,  0  CF3  I  -(CH2C)-- I  co-D 2 -Ry4,  II  0 