Two years ago, Larry Weissman was hired by Shamrock Technologies owner Bill Neuberg to become the company’s new CEO and president. Mr. Weissman had followed the same path taken by Jack Gallagher, who had left Elementis after it had purchased Rheox six months earlier to become vice president of worldwide sales.      Mr. Weissman had an enviable track record at Rheox. Under his leadership, the company expanded its product line from 62 to 155 offerings, and changed its primarily solvent-based off...