The Dow-Polysar ‘No-Gel’ Latex Foam Rubber Litigation

The litigation fought in the Chancery Division of the High Court in London between Dow Chemical AG/Ludlow Corporation as Plaintiffs and Spence Bryson & Company Limited/Polysar (UK) Limited as Defendants over the matter of the manufacture and sale of so-called ‘no-gel’ latex foam rubber is described. The technical background to the dispute is reviewed. Central to the dispute was the validity of a British patent, owned by the first Defendant, which claims a process for the manufacture of ‘no-gel’ latex foam rubber. This patent had been widely ignored by the manufacturers of no-gel latex foam, principally because it was believed that the fundamental idea of the process had been anticipated by earlier patents. These earlier patents are reviewed, and their relevance to the dispute discussed, as are some of the technical issues explored during the hearing. The outcome following the High Court hearing was partial victory for the Defendants. The overall judgement in favour of the Defendants was considerably strengthened following appeal by the Plaintiffs.