Production of extruded styrene resin foams which are excellent in
environmental compatibility and retain highly efficient thermal insulation
property and have appropriate strength properties is disclosed which is
characterized by using as a blowing agent a blowing agent comprising
mainly 40% by weight or more and 85% by weight or less, based on the whole
amount of the blowing agent, of at least one ether selected from the group
consisting of dimethyl ether, methyl ethyl ether and diethyl ether, and
15% by weight or more and 60% by weight or less, based on the whole amount
of the blowing agent, of at least one saturated hydrocarbon selected from
the group consisting of saturated hydrocarbons having 3 to 5 carbon atoms.
The production is further characterized by providing a more desirable cell
structure such as a specified shape of cells or the presence of larger and
smaller cells.
