Inventor

HEPWORTH JOHN D

GB4 patents

Patents

4 patents

US4913544AApr 3, 1990

Photochromic articles

PILKINGTON PLC154 citations95

US5520853AMay 28, 1996

Photochromic compounds

PILKINGTON PLC26 citations89

US5446151AAug 29, 1995

Photo reactive spiro-benzoxazine compounds

PILKINGTON PLC20 citations89

US5623005AApr 22, 1997

Photochromic naphthopyran compounds

PILKINGTON PLC49 citations88