Production of plastic foams, preferably rigid foams containing urethane groups or urethane and isocyanurate groups, and blowing agent-containing emulsions for this purpose

A process for the production of plastic foams which comprises mixing a resin selected from the group consisting of polyolefin phenolic, plyurethane and polyisocyanurate with at least one vinylfluoroalkane of the formula

• CH.sub.2 .dbd.CH--C.sub.n F.sub.2n+1
• in which --C.sub.n F.sub.2n+1 is linear or branched perfluoroalkyl and n is an integer from 3 to 6, as blowing agent and/or insulating gas, with the proviso that, if the vinylfluoroalkane is vinylperfluoro-n-butane, it is not employed in admixture with dichloroethylene or in admixture with more than 90% of 1,1-dichloro-1-fluoroethane and thereafter foaming said mixture with the application of heat.

A process for the production of plastic foams which comprises mixing a resin selected from the group consisting of polyolefin, polystyrene or polyvinylchloride, with at least one vinylfluoroalkane of the formula

• CH.sub.2 .dbd.CH--C.sub.n F.sub.2n+1
• in which --C.sub.n F.sub.2+1 is linear or branched perfluoroalkyll and n is an integer from 1 to 3, as blowing agent and/or insulating gas and thereafter foaming said mixture with the application of heat.

In a process for the production of phenolic foams, which comprises reacting co-reactants which make up a phenolic resin in the presence of a blowing agent, the improvement which consists of using at least one vinylfluoroalkane of the formula

• CH.sub.2 .dbd.CH--C.sub.n F.sub.2n+1
• in which --C.sub.n F.sub.2n+1 is linear or branched perfluoroalkyl and n is an integer from 3 to 6, as blowing agent and/or insulating gas, with the proviso that, if the vinylflluoroalkane is vinylperfluoro-n-butane, it is not employed in admixture with dichloroethylene or in admixture with more than 90% of 1,1-dichloro-1-fluoroethane and thereafter foaming said mixture with the application of heat.