0000950131-99-001909 DEF 14A 1 19990511 19990330 STEPAN CO 0000094049 2840 361823834 DE 1231 DEF 14A 34 001-04462 99578270 EDENS & WINNETKA RDS NORTHFIELD IL 60093 7084467500 EDENS & WINNETKA ROAD NORTHFIELD IL 60093 STEPAN CHEMICAL CO /DE/ 19840108 DEF 14A 1 000095013199001909-001-seq1-def-14a.txt DEFINITIVE NOTICE AND PROXY STATEMENT