TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preparation (Claimed): 2 Equivalence of hydrocarbon compound of formula: X-Ar1-(A-Ar2)p-X is made to react with respect to 1 equivalent of aromatic-ring containing compound of formula: Y'-(Ar"-A)m-((CH)h(-R3)-(Z)i-(CH)j(-R4))k-(O)q-R5 (a1), to obtain azomethine oligomer (I).X = aldehyde or amino;Ar", Ar1, Ar2 = optionally substituted bivalent aromatic group;p = 0-5;Y' =amino when X is aldehyde, or aldehyde when X is amino;m, i, q = 0 or 1;R3, R4 = H, 1-20C alkyl, or halo;Z = bivalent group which has oxygen atom or sulfur atom, or cycloalkylene;h, j = 0-12;k = 1-10; andR5 = 1-20C alkyl.(i) When Z is an oxygen atom or a sulfur atom, h and j are 1 or more;(ii) when k is 2 or more, -(CHR1)h-(Z)i-(CHR2)j- may be the same or different; and(iii) when q is 0 or 1, R3 is 1-20C alkyl and the carbon number in -(CHR3)h-(Z)i-(CHR4)j-)k-(O)q-R5 is 2-512.Preferred Properties: The molecular weight of the azomethine oligomer is 150-15000.The azomethine oligomer has 0.1 g of solubility with respect to co-solvents chosen from cresol, toluene, tetrahydrofuran, cyclopentyl methyl ether, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, chloroform, dichloromethane, carbon tetrachloride, chlorobenzene, carbon disulfide, ethyl acetate, butyl acetate and methyl lactate at 25 degrees C, and 100 g of solubility with respect to solvent chosen from methanol, ethanol, isopropyl alcohol, benzyl alcohol, n-butanol, t-butanol, pentyl alcohol, ethylene glycol, propylene glycol, propylene glycol monomethyl ether, pyridine, N-methyl-2-pyrrolidone, sulfuric acid, formic acid, acetic acid, hydrochloric acid, lactic acid, triethylamine and dibutyl amine at 25 degrees C.Preferred Components: The bivalent aromatic groups are chosen from 71 groups e.g. groups of formulae (VIII)-(XII).The aromatic-ring containing compound (a1) is chosen from 97 compounds e.g. of formulae (III)-(VII).The hydrocarbon compound is chosen from 12 compounds e.g. compound of formulae: Y'-(CH2)t-CH3, Y'-CH2-CH2-CH2-CH(-CH3)-CH2, CH3-CH2-CH2-CH(-CH3)-CH2-Y', Y'-CH2-CH2-O-CH2-CH2-O-CH2-CH3 or Y'-CH2-CH2-O-CH2-CH2-O-CH2-CH2-O-CH2-CH3.t = 5-11. EXAMPLE - (In g) 1,4-phenylene diamine (2.7), m-cresol (5) and toluene (30) were added to nitrogen-substituted flask, heated at 70 degrees C and stirred. The solution obtained by dissolving p-amino benzaldehyde (1.21) in toluene (30) was dripped to obtained solution for more than 3 hours, volatile solvent was removed and concentrate was vacuum-dried, to obtain aromatic ring-containing compound (1.67) as pale yellow oil. Undecanal (4.26), m-cresol (5) and toluene (30) were added to nitrogen-substituted flask, heated at 70 degrees C and stirred. The solution obtained by dissolving aromatic ring-containing compound (3.4) in toluene (30) was dripped to obtained solution for more than 3 hours, volatile solvent was removed and concentrate was vacuum-dried, to obtain azomethine oligomer (3.09) as pale yellow solid.