Expandable, thermally hardenable composition, useful for injection molding to produce ductile structural foams, is based on epoxy resin, phenolic compound and polyether-amine

摘要

An expandable, thermally hardenable composition (I) contains (a) epoxy resin(s), (b) phenolic compound(s), solid at room temperature, (c) polyether-amine(s), (d) blowing agent(s), (e) hardener(s) and (f) filler(s). Independent claims are included for: (1) the preparation of (I), by: (i) blending components (a)-(f) at less than 110 (preferably 80-95)[deg] C; (ii) extruding at less than 110 (preferably 80-95)[deg] C, optionally onto a cooled metal belt, to form granules; (iii) cooling the granules and optionally storing (specifically in containers, big bags, casks or sacks); (iv) supplying the granules to an injection molding machine, (v) melting at less than 110[deg] C and injecting the melt into a mold; and (vi) cooling and demolding the obtained article of (I); (2) a variant of the method, in which the mixture of (a)-(d) is extruded to a shaped intermediate product (rather than granules), which is optionally stored (specifically in shelving or casks) before supply to the injection molding machine; (3) injection moldings obtained by the methods; and (4) structural foams (II) (preferably obtained by expansion and thermal hardening of (I)) showing a compression strength of at least 15 MPa on deformation of a test piece by 10-15 % at -20[deg] C und no significant reduction in force level on deformation of a test piece by 50% at -20[deg] C (ASTM D 1621).