Patent ID: 7968003

Claim:
A pyran derivative of the following formula I: Wherein R is H, C 1 ˜C 15 alkyl, C 2 ˜C 15 alkenyl or R 1 O—; R 1 is H, C 1 ˜C 15 alkyl or C 2 ˜C 15 alkenyl group; ring C is ring A and ring B are independently Y 1 is H, F, Cl, CN or CF 3 ; Y 2 is F, Cl, CN or CF 3 ; a 1 and a 2 are independently O or N; Z 1 , Z 2 and Z 3 are independently —(CH 2 ) n — (n is 0 or 2), —C≡C—, —C(═O)O—, —OC(═O)—, —CF 2 O—, —OCF 2 —, —OC(═O)O—, —CH 2 O—, —CH 2 C(═O)—, —OCH 2 — or —C(═O)CH 2 —; X is Cl, F, CF 3 , OCF 3 , OCHF 2 , CHF 2 , CH 2 F, OCF 2 CHF 2 or OCF 2 CHFCH 3 ; L 1 to L 8 are independently H or F; and, j, k, l, and m are independently 0, 1 or 2.