sentences:  In 1880 he founded the Beiersdorf Company, a Hamburg pharmaceutical operation where he had close business ties to dermatologist Paul Gerson Unna.In 1882 Beiersdorf developed and patented a new type of medical plaster called "Guttaperchapflastermulle" (gutta-percha plaster gauze).The date of patent specification, 28 March 1882, is considered to be the founding date of Beiersdorf AG.