Patent ID: 8029697

Claim:
A naphthalene derivative represented by formula (1) wherein Ar 1 to Ar 6 each represent a substituted or unsubstituted aromatic hydrocarbon cyclic group having 6 to 18 carbon atoms forming a ring, the substituted or unsubstituted aromatic hydrocarbon cyclic group having none of anthracene skeleton, pyrene skeleton, aceanthrylene skeleton and naphthacene skeleton, Ar 1 and Ar 2 each being allowed to be bonded in any position of a benzene skeleton; R 1 to R 3 each represent an alkyl group, a cycloalkyl group, an alkoxy group, a cyano group, a silyl group or a halogen atom, R 1 to R 3 each being allowed to be bonded in any position of a main-chain naphthalene skeleton or a main-chain benzene skeleton; a, b and c each represent an integer in a range of 0 to 4; a represents the number of substituent(s) R 1 directly bonded to the main-chain benzene; b represents the number of substituent(s) R 2 directly bonded to the main-chain naphthalene; c represents the number of substituent(s) R 3 directly bonded to the main-chain benzene; l, m, n and p each represent 0 or 1; R 1 , R 2 and R 3 each are allowed to be mutually the same or different; when a, b and c each are 2 or more, the plurality of R 1 are allowed to be mutually the same or different, the plurality of R 2 are allowed to be mutually the same or different, the plurality of R 3 are allowed to be mutually the same or different or the pluralities of R 1 to R 3 are allowed to be the same as or different from one another; Ar 1 to Ar 6 are allowed to mutually the same or different; when at least either one of l and n is 1, Ar 1 represents neither a benzene skeleton nor a naphthalene skeleton; when at least either one of m and p is 1, Ar 2 represents neither a benzene skeleton nor a naphthalene skeleton; the structure represented by (H—[Ar 5 ] n —[Ar 3 ] l —Ar 1 —) is not the same as the structure represented by (H—[Ar 6 ] p —[Ar 4 ] m —Ar 2 —); when the naphthalene derivative has a structure in which two naphthalene skeletons are consecutively bonded together, the structure of the naphthalene derivative is represented by any one of formulae (1-A), (1-B), (1-C) and (1-D): the naphthalene skeletons represented by the formulae (1-A), (1-B) and (1-C) each are allowed to have a substituent(s) in any suitable position(s) or unsubstituted; R in the formula (1-D) represents a substituent, R representing a single substituent or plural substituents, the single substituent or the plural substituents being allowed to be in any position(s) of the two naphthalene skeletons, the plural substituents when R represents the plural substituents being allowed to be mutually the same or different; when the naphthalene derivative contains a plurality of unsubstituted 9-phenanthrenes, the number of the unsubstituted 9-phenanthrenes is 3 or more; and when Ar 1 to Ar 6 each represent a phenanthrene skeleton, the phenanthrene skeleton is monovalent phenanthrene.