The invention claimed is:
1. A blocked isocyanate comprising a latent isocyanate group, which is an isocyanate group blocked with a blocking agent,
wherein the blocked isocyanate comprises a first latent isocyanate group that is an isocyanate group blocked with a first blocking agent and a second latent isocyanate group that is an isocyanate group blocked with a second blocking agent,
the first latent isocyanate group and the second latent isocyanate group are both present in one molecule, or are present separately in different molecules in which only the first latent isocyanate group is present in one molecule and only the second latent isocyanate group is present in another molecule,
the first blocking agent is represented by general formula (1) below,
a dissociation temperature at which the first blocking agent and the second blocking agent in the blocked isocyanate comprising the first latent isocyanate group and the second latent isocyanate group are dissociated is lower than a dissociation temperature at which the second blocking agent in a blocked isocyanate comprising only the second latent isocyanate group and not comprising the first latent isocyanate group is dissociated, and
1 mol % or more and 30 mol % or less of the first latent isocyanate group is contained relative to a total mol of the first latent isocyanate group and the second latent isocyanate group:
(where R1 to R3 represent a hydrocarbon group having 1 to 12 carbon atoms or a hydrogen atom, and at least one of R1 to R3 represents a hydrogen atom, and R1 and R3 are optionally bonded to each other to form a heterocycle; R4 represents an atomic group represented by —NR 5 R 6 (R5 and R6 represent a hydrocarbon group having 1 to 12 carbon atoms, and R5 and R1 are optionally bonded to each other to form a heterocycle and R6 and R3 are optionally bonded to each other to form a heterocycle)).
2. The blocked isocyanate according to claim 1 , wherein the dissociation temperature of the second blocking agent is 130° C. or less.
3. The blocked isocyanate according to claim 1 , wherein the first latent isocyanate group and the second latent isocyanate group are both present in one molecule.
4. The blocked isocyanate according to claim 1 , wherein the second blocking agent is at least one selected from the group consisting of an amine compound, a pyrazole compound and an imidazole compound.
5. The blocked isocyanate according to claim 1 , wherein the blocked isocyanate is modified with a hydrophilic compound containing an active hydrogen group.
6. The blocked isocyanate according to claim 5 ,
wherein the blocked isocyanate is a reaction product of
a hydrophilic group-containing polyisocyanate in which a portion of the isocyanate group is allowed to react with the active hydrogen group of the hydrophilic compound, and also the remaining portion of the isocyanate group is in free-state, and
the first blocking agent and the second blocking agent; and
the hydrophilic compound is a polyoxyethylene compound having at least three continuous ethylene oxide groups; and
7 mass % or more and 30 mass % or less of the ethylene oxide groups is contained in the hydrophilic group-containing polyisocyanate.
7. A coating composition comprising a blocked isocyanate,
wherein the blocked isocyanate is a blocked isocyanate containing a latent isocyanate group, which is an isocyanate group blocked with a blocking agent,
the blocked isocyanate comprises a first latent isocyanate group that is an isocyanate group blocked with a first blocking agent and a second latent isocyanate group that is an isocyanate group blocked with a second blocking agent,
the first latent isocyanate group and the second latent isocyanate group are both present in one molecule, or are present separately in different molecules in which only the first latent isocyanate group is present in one molecule and only the second latent isocyanate group is present in another molecule,
the first blocking agent is represented by general formula (1) below,
a dissociation temperature at which the first blocking agent and the second blocking agent in the blocked isocyanate comprising the first latent isocyanate group and the second latent isocyanate group are dissociated is lower than a dissociation temperature at which the second blocking agent in a blocked isocyanate comprising only the second latent isocyanate group and not comprising the first latent isocyanate group is dissociated, and
1 mol % or more and 30 mol % or less of the first latent isocyanate group is contained relative to a total mol of the first latent isocyanate group and the second latent isocyanate group:
(where R1 to R3 represent a hydrocarbon group having 1 to 12 carbon atoms or a hydrogen atom, and at least one of R1 to R3 represents a hydrogen atom, and R1 and R3 are optionally bonded to each other to form a heterocycle; R4 represents an atomic group represented by —NR 5 R 6 (R5 and R6 represent a hydrocarbon group having 1 to 12 carbon atoms, and R5 and R1 are optionally bonded to each other to form a heterocycle and R6 and R3 are optionally bonded to each other to form a heterocycle)).
8. An adhesive composition comprising a blocked isocyanate,
wherein the blocked isocyanate is a blocked isocyanate containing a latent isocyanate group, which is an isocyanate group blocked with a blocking agent,
the blocked isocyanate comprises a first latent isocyanate group that is an isocyanate group blocked with a first blocking agent and a second latent isocyanate group that is an isocyanate group blocked with a second blocking agent,
the first latent isocyanate group and the second latent isocyanate group are both present in one molecule, or are present separately in different molecules in which only the first latent isocyanate group is present in one molecule and only the second latent isocyanate group is present in another molecule,
the first blocking agent is represented by general formula (1) below,
a dissociation temperature at which the first blocking agent and the second blocking agent in the blocked isocyanate comprising the first latent isocyanate group and the second latent isocyanate group are dissociated is lower than a dissociation temperature at which the second blocking agent in a blocked isocyanate comprising only the second latent isocyanate group and not comprising the first latent isocyanate group is dissociated, and
1 mol % or more and 30 mol % or less of the first latent isocyanate group is contained relative to a total mol of the first latent isocyanate group and the second latent isocyanate group:
(where R1 to R3 represent a hydrocarbon group having 1 to 12 carbon atoms or a hydrogen atom, and at least one of R1 to R3 represents a hydrogen atom, and R1 and R3 are optionally bonded to each other to form a heterocycle; R4 represents an atomic group represented by —NR 5 R 6 (R5 and R6 represent a hydrocarbon group having 1 to 12 carbon atoms, and R5 and R1 are optionally bonded to each other to form a heterocycle and R6 and R3 are optionally bonded to each other to form a heterocycle)).
9. An article coated with a coating composition,
wherein the coating composition comprises a blocked isocyanate,
the blocked isocyanate is a blocked isocyanate containing a latent isocyanate group, which is an isocyanate group blocked with a blocking agent,
the blocked isocyanate comprises a first latent isocyanate group that i