| abstract |
A pumpable, thermoplastic desiccated mastic capable of desiccating a sealed insulating glass unit. The disclosed compositions comprise: A) a resin component consisting essentially of: i) 4-75 % by weight of the resin component of a film former, the film former including a member selected from the group consisting of: a) a homogeneous substantially linear ethylene/α-olefin interpolymer; b) a linear, Y block or star block copolymer rubber; c) a liquid polybutene polymer; or d) mixtures of a, b, and/or c; alone, or combination with one or more polymers selected from the group consisting of: e) a polyisobutylene polymer having a weight average molecular weight of about 35,000 or more; and f) a butyl rubber having a weight average molecular weight of up to about 500,000, said butyl rubber, if present, representing less than 50 % of the film former component; ii) 25-96 % by weight of the resin component of an alkylene polymer component consisting of a member selected from the group consisting of: a) a non-crystalline homopolymer, copolymer, terpolymer or graft copolymer comprising a monomeric unit of propylene; b) a homogeneous substantially linear ethylene/α-olefin interpolymer; and c) mixtures thereof; iii) 0-20 % by weight of the resin component of a low volatile UV stable tackifier compatible with the film former and alkylene components; and a dessicant/adsorbent component comprising: i) at least 20 % by weight of the composition of a desiccant or moisture and volatile organic chemical adsorbing material; and ii) 0-10 % by weight of the composition of an adsorbent of volatile organic compounds, said desiccant/adsorbent component being present in an amount less than the level which will cause the composition when tested as set forth in ASTM D-1238, Procedure B using a 1100 gram load and an 8 gram sample at 190 °C to provide a melt flow time for a piston travel of 2.54 cm (1 inch) of more than 60 seconds. |