NEW YORK--(BUSINESS WIRE)--The following statement is being issued by Robbins Geller Rudman & Dowd LLP regarding the ShengdaTech Inc. Securities Litigation: UNITED STATES DISTRICT COURTSOUTHERN DISTRICT OF NEW YORK       In re SHENGDATECH, INC. SECURITIES ) Master No. 1:11-cv-01918-LGS LITIGATION )   ) CLASS ACTION This Document Relates To: )   ALL ACTIONS. )   SUMMARY NOTICE TO: ALL PERSONS WHO PURCHASED THE COMMON STOCK OF SHENGDATECH, INC. (“SHENGDATECH” OR THE “COMPANY”) BETWEEN MAY 6,