| 摘要 |
The description relates to a process for producing hard polyurethane foams with low heat conductivity from polyols and polyisocynates, foaming agents and possibly foaming auxiliaries, in which the hard polyurethane foam is obtained by reacting: A. a polyol component containing 1. at least one polyester polyol of a molecular weight of 100 to 30,000 g/mol with at least two hydrogen atoms reactive to isocyanates, 2. at least two hydrogen atoms reactive to isocyanates and compounds containing at least one tertiary nitrogen atom and with a molecular weight of 150 to 12,500 g/mol, 3. compounds containing at least two hydrogen atoms reactive to isocyanates with a molecular weight of 150 to 12,500 g/mol, 4. catalysts, 5. water, 6. foaming agents and 7. possibly auxiliaries and/or additives; with: B. an organic and/or modified organic polyisocyanate with an NCO content of 20 to 48 % wt. In addition, cyclopentaneblown hard foams with low heat conductivity and their use as intermediate layers for composite components and for foam-filling hollow spaces are described.
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