On September 15th, Czarnetzky & Son, Inc. ("Czarnetzky & Son") borrowed money from Equipment Finance Corp. ("Equipment") and granted Equipment a security interest in all equipment then owned and thereafter acquired. A proper security agreement was executed by the parties, and a proper financing statement filed in the appropriate office. On October 15th, after the retirement of Bill Czarnetzky, Sr., Czarnetzky & Son changed its name to Czarnetzky Equipment, Inc ("Czarnetzky Equipment"). On that same date, Czarnetzky Equipment borrowed money from Small Bank and granted Small Bank a security interest in all equipment then owned and thereafter acquired. On December 15th, and then three months later on March 15, Czarnetzky Equipment purchased some equipment from Del Mar Co.. Five days later, Czarnetzky Equipment went into liquidation proceeding. 

Who has priority in the equipment purchased on December 15th and March 15th, and why?