Rohm and Haas Company

F Thomas Sanderson

David R Gehman

Disclosed are contact adhesives, containing aqueous polymeric latexes, particularly acrylic latexes. Contact adhesives are adhesives which dry to a non-tacky state but which will adhere to another surface of the same dried adhesive. A unique feature of the adhesives is that the polymer used therein has an extremely wide range of molecular weights with substantial proportions of the product having a low molecular weight and substantial portions having a very high molecular weight, preferably with fairly uniform progression from low molecular weight to high molecular weight. However, blends of a low molecular weight fraction and a high molecular weight polymer may also be used. The preferred procedure is to prepare an emulsion polymer by reacting part of the material in the reactor in such a way as to obtain a high molecular weight product and to react at least one other portion of the monomer in the same reactor in such a way as to obtain at least one low molecular weight fraction. The adhesives preferably contain an aminoplast or a phenoplast as a tackifier and crosslinker and may contain a thickening agent such as polyvinyl alcohol. Also disclosed are articles of manufacture laminated by means of the adhesives and methods of preparing the same.

Growing community of inventors

Warminster, PA, United States of America

F Thomas Sanderson