PROCESS FOR MAKING FOAM RESINS

摘要

Process for making foam resins starting from a first composition, which is polymerizable through a radicalic mechanism, contained in a reservoir (1) and by a second polymerizable composition, for example an epoxy resin and an anhydride, which at room temperature is in the liquid state, contained in a reservoir (2). In particular, the first composition contains a catalyst for triggering polymerization in the second composition and the second composition comprises a catalyst for triggering polymerization in the first composition. In particular, the first composition comprises a polyester, a vinylester or an acrylic compound. In particular, the second composition comprises an epoxy resin, for example a mono-glycidyl-ether, a di-glycidyl-ether or a tri-glycidyl- ether and by an anhydride that can be: phthalic anhydride, tetra-hydro-phtalic anhydride, HET anhydride, methyl-nadic anhydride. Through a pressurized duct (11 or 13) a determined amount of a swelling gas is added, for example CO<SUB>2</SUB> or N<SUB>2</SUB>, in two respective reservoirs (1 or 2), then the compositions and the swelling dissolved gas are sent by means of volumetric pumps (20) to a mixer (3) in which they are mixed and some process parameters are controlled, in particular viscosity. The mixture obtained is then brought to an expansion head (35) in which a controlled expansion is achieved of the mixture that causes a pressure reduction and causes a gas solubility decrease in the liquid that expands in the liquid mass forming bubbles.