Patent ID: 9650468
Date: 2017-05-16
CPC Classifications: B01J,C08G

Claim:
1. A method of reducing the propagation of stress, comprising: supplying microcapsules having a total volume and containing an encapsulated mixture of reactant amine compounds comprising at least a primary amine compound and a secondary amine compound wherein said mixture of amine compounds are present in the range of 40% to 80% of said microcapsule total volume, said microcapsules having a size of 1 micron to 200 microns including a shell portion, wherein said shell comprises a polyurea shell of the structure: wherein R is an alkyl group, substituted alkyl group, aromatic group or substituted aromatic group and said polyurea shell has a thickness of less than or equal to 20 microns; distributing said microcapsules in the presence of an epoxy prepolymer in a selected structure wherein said epoxy prepolymer has the following formula: where n may have a value of 0-1000; wherein upon introduction of stress into said structure, said microcapsules release said mixture of reactant amine compounds, such that at least said primary amine compound and secondary amine compound react with said epoxy prepolymer to form a crosslinked epoxy polymer having a tensile strength of at least 12,500 psi and a tensile modulus of 400,000 psi to 4×10