摘要 |
<p>This invention relates to a novel, environmentally acceptable blowing agent and blowing agent blends and a process for producing thermalplastic, and particularly polyolefin foams using the environmentally acceptable blowing agent(s). The blowing agents of the present invention comprise difluoromethane and optionally a second blowing agent component which is nonflammable and possesses good blowing agent properties. Polyolefin foam is made by mixing a polyolefin resin and the blowing agent and introducing the resin/blowing agent mixture into a zone of lower pressure.</p> |