| 摘要 |
Adhesives and sealants, based on polyurethane reactants, are provided. The one-component frozen premix material of the invention comprises: (a) up to about 60 vol % of at least one filler; (b) about 0.5 to 5 wt % of a thixotrope comprising hydrophobic fumed silica; and (c) the balance a urethane matrix. The urethane matrix comprises at least one polyol that includes at least one carbon-carbon double bond in its backbone and has less than 20 wt % of ether and ester moieties, at least one aliphatic polyisocyanate in stoichiometric amount relative to the polyol, and about 0.01 to 0.1 wt % of an organo-metallic catalyst. The urethanes of the invention can be stored as one-component, frozen, premix materials for a minimum of three months, and, when thawed, can be applied with a spatula or trowel to form non-sag fillets. The cured elastomers are free of voids, tears, or bubbles.
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