Curable resin composition
Disclosed is a structural material-bonding adhesive capable of bonding materials other than iron, and maintaining the bonding ability in an environment at a high temperature and a low temperature, while maintaining performance similar to that of a structural material adhesive used as an adhesive for bonding iron materials. A curable resin composition contains an epoxy resin, blocked urethane, and an amine-based latent curing agent, wherein the blocked urethane is obtained by reacting a urethane polymer having a terminal isocyanate group with a blocking agent, the urethane polymer being obtained by reacting a polyisocyanate, a diol, and a branching agent containing at least three groups that react with an isocyanate group.
1. A curable resin composition comprising an epoxy resin (A), blocked urethane (C), and an amine-based latent curing agent (D),
wherein the blocked urethane (C) is obtained by reacting a urethane polymer having a terminal isocyanate group with a blocking agent (C-4), the urethane polymer being obtained by reacting a polyisocyanate (C-1), a diol (C-2), and a branching agent (C-3) containing at least three groups that react with an isocyanate group,
the ratio (number of NCO groups/number of NCO reactive groups) between the number of moles of isocyanate groups in the component (C-1) (number of NCO groups) and the total number of moles of hydroxyl groups in the component (C-2) and groups that react with an isocyanate group in the component (C-3) (number of NCO reactive groups) is from 1.4 to 1.6, and
the proportion of the number of moles of groups that react with an isocyanate group in the component (C-3) is from 10 to 41% of the total number of moles of hydroxyl groups in the component (C-2) and groups that react with an isocyanate group in the component (C-3), and
wherein the component (C-3) is at least one member selected from the group consisting of a propylene oxide adduct of glycerin and a propylene oxide adduct of trimethylolpropane.
2. The curable resin composition according to claim 1 , further comprising a rubber component (B).
3. The curable resin composition according to claim 1 , wherein the diol (C-2) is at least one selected from the group consisting of a propylene oxide using water or propylene glycol as an addition polymer initiator, and a polytetramethylene glycol.
4. A structural material-bonding adhesive comprising the curable resin composition according to claim 1 .
5. A cured material obtained by curing the curable resin composition according to claim 1 .
6. The curable resin composition according to claim 2 , wherein the diol (C-2) is at least one selected from the group consisting of a propylene oxide using water or propylene glycol as an addition polymer initiator, and a polytetramethylene glycol.
7. A structural material-bonding adhesive comprising the curable resin composition according to claim 2 .
8. A structural material-bonding adhesive comprising the curable resin composition according to claim 3 .
9. A cured material obtained by curing the curable resin composition according to claim 2 .
10. A cured material obtained by curing the curable resin composition according to claim 3 .