TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preparation (disclosed): Dihalogenated aryl compound of formula: X1-Q-X2 is reacted with halogenated difluoro ethyl acetate of formula: X3CF2CO2R in presence of copper, and the obtained halogenated difluoro acetate of formula: RO2CF2OC-Q-CF2CO2R is hydrolyzed to obtain fluorine-containing dicarboxylic acid derivative of formula: HO2CF2C-Q-CF2CO2H.X1-X4=halo;andR=1-6C alkyl or 6-10C aryl.    TECHNOLOGY FOCUS - POLYMERS - Preferred Compounds: The high molecular compound of formula (II) is obtained by polycondensing acid derivative (I) with diamine compound of formula: H2N-R2-NH2 (III). The high molecular compound of formula (IV) is obtained by polycondensing acid derivative (I) with diamino diol compound of formula: H2N-R3(-NH2)(-OH)-OH (V). The high molecular compound of formula (VI) is obtained by carrying out dehydration ring closure of high molecular compound (IV). The high molecular compound of formula (VII) is obtained by polycondensing acid derivative (I) with diamino diol substituted with hexafluoro isopropanol of formula (VIII). The high molecular compound of formula (IX) is obtained by carrying out dehydration ring closure of high molecular compound (VII). The high molecular compound of formula (X) is obtained by polycondensing acid derivative (I) with diol compound of formula: HO-R1-OH (XI)R1,R2=divalent organic group containing alicyclic ring, aromatic ring or heterocyclic ring, each having fluoro, chloro, oxygen atom, sulfur atom or nitrogen atom, where H of divalent organic group is optionally substituted by fluoro, chloro, alkyl, fluoroalkyl, carboxy, hydroxy or cyano, and carbon atom of divalent organic group is optionally substituted by oxygen atom, sulfur atom, nitrogen atom, carbonyl or sulfonyl;m=positive integer;andR3,R4=tetravalent organic group containing alicyclic ring, aromatic ring or heterocyclic ring, each having fluoro, chloro, oxygen atom, sulfur atom or nitrogen atom, where H of tetravalent organic group is optionally substituted by fluoro, chloro, alkyl, fluoroalkyl, carboxy, hydroxy or cyano, and carbon atom of tetravalent organic group is optionally substituted by oxygen atom, sulfur atom, nitrogen atom, carbonyl or sulfonyl. Preferred Definitions:    Q=group of formula (i) or (ii), preferably group chosen from groups of formulae (iii)-(vii);    Ar1,Ar2=aromatic ring optionally substituted by fluoro, chloro, hydroxy, amino, nitro, cyano, hydroxycarbonyl, 1-6C alkyl (optionally substituted by hydroxy or fluoro), monovalent group having aromatic ring, 1-6C alkoxy or 1-6C alkoxycarbonyl;    Y1,Y2=single bond or bivalent group chosen from CH2, CH2CH2, CH2CH2CH2, O, S, C(CH3)2, C(CF3)2, SO2, CO, NH, ester group and CONH;and    p=0-3.    EXAMPLE - Dicarboxylic acid (in g) (49) and acetonitrile (50 mL) were added to glass flask, thionyl chloride (50) was dripped, stirred, and reacted at room temperature for 18 hours, to obtain ( alpha ),( alpha 4),( beta ),( beta 4)-tetrafluoro-1,4-benzene diacetyl chloride. 2,2-Bis(4-hydroxyphenyl)-propane(bisphenol A) (2.28) and N-methyl-2-pyrrolidone (20) were added to three-necked flask, stirred under nitrogen atmosphere, ( alpha ),( alpha 4),( beta ),( beta 4)-tetrafluoro-1,4-benzene diacetyl chloride (3.03) was dripped for 10 minutes, stirred for 1 hour and neutralized. The lithium carbonate (0.7) was added to generated hydrogen chloride, obtained viscous solution is added to methanol (500 mL), and vacuum-dried at 80 degrees C, to obtain polymer (4.13).