Patent ID: 7138202

Claim:
A method of forming seals in an electrochemical cell assembly comprising a plurality of separate elements, the method comprising injecting a curable seal material into a groove network within the fuel cell assembly, the curable seal material comprising: (a) 100 parts by weight of a polydiorganosiloxane containing two or more silicon-atom-bonded alkenyl groups in each molecule; (b) 5–50 parts by weight of a reinforcing filler; (c) 1–20 parts by weight of an oxide or hydroxide of an alkaline earth metal with an atomic weight of 40 or greater; (d) an organohydrogensiloxane containing three or more silicon-atom-bonded hydrogen atoms in each molecule, the hydrogen atoms being present in an amount providing a molar ratio of silicon-atom-bonded hydrogen atoms in component (d) to silicon-atom-bonded alkenyl groups in component (a) which is in a range of 0.4:1 to 5:1; and (e) a platinum-type metal catalyst in an amount providing 0.1–500 parts by weight of platinum-type metal per one million parts by weight of component (a); wherein at least portions of the groove network within the electrochemical cell assembly are defined solely by the elements of the electrochemical cell assembly and the method comprises using the curable seal material to form a seal including a seal between at east two adjacent elements of the electrochemical cell assembly that define a chamber for a fluid for operation of the electrochemical cell assembly.