Heat curable epoxy resin composition with water as foaming agent
AssigneeSika Technology AG
InventorsJürgen Finter, Elyes Jendoubi
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Abstract
Heat-curable epoxy resin compositions and the use thereof, for example, in motor vehicle construction and sandwich panel construction, are disclosed. Exemplary heat-curable epoxy resin compositions include, in addition to epoxy resin components A1, optionally A2, a hardener component B, a carboxylic acid C and a hydroxyalkylamide or hydroxyalkylurea H, an accelerator E for activation of the conversion of components A1, A2 and B. The compositions and the structural foams produced therefrom are notable for high mechanical strength, high glass strength and good adhesion capacity on metallic and nonmetallic substrates, and it is possible at the same time to dispense with the use of toxic or inflammable blowing agents.
Claims20
A heat-curable epoxy resin composition, comprising:
- (a) at least one solid epoxy resin A1 having an average of more than one epoxide group per molecule;
- (b) at least one hardener B for epoxy resins which is activated by elevated temperature;
- (c) at least one carboxylic acid C;
- (d) at least one hydroxyalkylamide or hydroxyalkylurea H;
- and
- (e) optionally at least one liquid epoxy resin A2 with an average of more than one epoxide group per molecule,
- wherein the heat-curable epoxy resin composition further comprises at least one accelerator E based on a urea derivative for activating a reaction of components A1, and optionally A2, with B, and
- wherein a proportion of the accelerator E is selected such that an onset temperature of a reaction of the hydroxyalkylamide or hydroxyalkylurea H with the carboxylic acid C, measured by DSC, is at least 20° C. higher than an onset temperature of the reaction between the solid epoxy resin A1, optionally liquid epoxy resin A2 and hardener B.
Dependencies are inferred from the claim text.