UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 ___________________________________________________________ Form 10-K þ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the Fiscal Year Ended December 31, 2018 o TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number 001-08454 ACCO Brands Corporation (Exact Name of Registrant as Specified in Its Charter) De ...