| 摘要 |
2088244 9202585 PCTABS00010 Heat curable adhesive compositions which include liquid polybutadiene polymer, powdered sulfur, organic accelerators and inert fillers are improved by adding blocked polyisocyanates or capped polyisocyanates. The addition improves resistance to "popping" of the cured or uncured adhesive when exposed to high temperatures, e.g., spot-welding. The addition does not alter the beneficial flow properties and rheological properties of the adhesive. The adhesive is particularly useful on zinc coated steel, both electroplated zinc and hot-dip galvanized zinc coatings. Inclusion of zinc borate will activate the cure accelerators and retard the "popping" phenomenon at welding temperatures.
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