| 摘要 |
The material based on bitumen, natural or synthetic resins, including thermoplastics, or a mixture of such starting materials is non-self-supporting and contains gas-evolving agents and optionally additionally a filler. Through gas evolution at elevated temperature, the material can be foamed to give a porous, foam-like structure, where at least 20% of the pores formed are preferably closed. For sound deadening of metal sheeting, in particular in bodywork, at the same time as paint baking, sheets or films of this material are expediently coated on the reverse with hot-melt or contact adhesives. The preparation is carried out by mixing the base materials with the gas-evolving agent. After the material has been applied in sheet or film form to the article whose structure-borne sound is to be deadened, the gas is liberated from the gas-evolving agent by warming, optionally in the presence of water. |
