Morton International, Inc.

Rutgerswerke Aktiengesellschaft

Raymond Robinson

Timothy C Lee

George B Lowe

Lothar Hockenberger

Karl Ruehl

Peter Endruscheit

Ernst Scherp

Franz-Josef Bergmann

A one-part polysulfide sealant composition comprises a mercaptan-terminated liquid polysulfide, an oxidising agent to cure the catalyst a desiccant such as a molecular sieve, to keep the composition dry and thus prevent premature activation of the catalyst, and a cure accelerator having an acrylate or methacrylate functionality of 2 or more, preferably an acrylated liquid polysulfide or a polyfunctional methacrylate monomer. The use of this accelerator avoids the need for toxic amounts of barium oxide desiccant and substantially shortens the tack-free time on curing.

Single-component polysulphide based sealant compositions

Curing of polysulphides

Polysulfide sheeting is prepared by mixing a curable polysulfide oligomer or polymer, carbon black, and manganese dioxide as a hardening catalyst; forming the composition into a sheet; and curing the sheet at an elevated temperature. The sheeting has unusually high short-term heat resistance, so it will not lose its watertightness when coated with hot-laid asphalt at 240.degree. C. It has better resistance to ultraviolet light than conventional polysulfide sheeting, and good penetration and compression set resistance. The sheeting can be laminated to a reinforcing layer, if desired. A continuous waterproofing layer can be formed by laying pieces of the sheeting in overlapping relation, placing an uncured polysulfide rope between the overlapping edges of adjacent pieces of sheeting, and curing the rope, thus joining the pieces to form an integral sheet. Such waterproof layers can be incorporated into paving for bridges, roofs, and other structures.

Polysulfide sheeting

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Wyken, United Kingdom

Raymond Robinson