Aluminum chelate latent curing agent
A novel aluminum chelate latent curing agent that can cure a glycidyl ether epoxy compound at a lower temperature and more quickly than an aluminum chelate latent curing agent produced by emulsification and interfacial polymerization of a polyfunctional isocyanate in the presence of both a radical polymerizable monomer, such as divinyl benzene, and a radical polymerization initiator, is micro-encapsulated in a core-shell form, wherein an aluminum chelate curing agent and a cationic polymerizable compound are included in a capsule formed from an interfacial polymerization product of a polyfunctional isocyanate.
1. A micro-encapsulated aluminum chelate latent curing agent in a core-shell form, comprising:
a microcapsule wall, formed from an interfacial polymerization product of a polyfunctional isocyanate; and
an aluminum chelate curing agent and a cationic polymerizable compound encapsulated by the microcapsule wall,
wherein a radical polymerizable compound and a silanol compound are not encapsulated by the microcapsule wall.
2. The micro-encapsulated aluminum chelate latent curing agent according to claim 1 , wherein the cationic polymerizable compound is a cyclic ether compound.
3. The micro-encapsulated aluminum chelate latent curing agent according to claim 2 , wherein the cyclic ether compound is an alicyclic epoxy compound and/or an oxetane compound.
4. The micro-encapsulated aluminum chelate latent curing agent according to claim 1 , wherein the microcapsule wall is subjected to an impregnation treatment of an aluminum chelate curing agent solution.
5. The micro-encapsulated aluminum chelate latent curing agent according to claim 1 , wherein the cationic polymerizable compound is encapsulated by the microcapsule wall in an amount of 10 to 300 parts by mass with respect to 100 parts by mass of the aluminum chelate curing agent.
6. The micro-encapsulated aluminum chelate latent curing agent according to claim 1 , wherein the aluminum chelate curing agent and the cationic polymerizable compound are encapsulated by the microcapsule wall in a total amount of 100 to 2,000 parts by mass with respect to 100 parts by mass of the microcapsule wall.
7. A production method of the micro-encapsulated aluminum chelate latent curing agent according to claim 1 , comprising:
dissolving the polyfunctional isocyanate, the aluminum chelate curing agent and the cationic polymerizable compound in a volatile organic solvent in an aqueous phase containing water, a dispersant, and a surfactant to form an oil phase;
emulsifying the oil phase; and
subjecting the polyfunctional isocyanate to interfacial polymerization while maintaining the emulsified state, to allow the aluminum chelate curing agent and the cationic polymerizable compound to be encapsulated by the microcapsule wall formed from the interfacial polymerization product of the polyfunctional isocyanate.
8. The production method according to claim 7 , wherein a ratio of an amount of the volatile organic solvent in the oil phase is from 1 to 50 parts by mass with respect to 100 parts by mass of a total amount of the aluminum chelate curing agent, the polyfunctional isocyanate compound, and the cationic polymerizable compound.
9. A thermosetting epoxy resin composition, comprising the micro-encapsulated aluminum chelate latent curing agent according to claim 1 , a glycidyl ether epoxy compound, and a silanol compound represented by the formula (A),
(Ar) m Si(OH) n (A)
wherein m is 2 or 3, the sum of m and n is 4, and Ar represents an optionally substituted aryl group.
10. The thermosetting epoxy resin composition according to claim 9 , wherein the silanol compound is triphenylsilanol or diphenylsilanol.
11. The thermosetting epoxy resin composition according to claim 9 , wherein a content ratio of the silanol compound to a total amount of the silanol compound and the glycidyl ether epoxy resin in the thermosetting epoxy resin composition is from 5 to 30 mass %.
12. The thermosetting epoxy resin composition according to claim 9 , wherein the glycidyl ether epoxy compound is a bisphenol A epoxy compound and/or a bisphenol F epoxy compound.
13. The thermosetting epoxy resin composition according to claim 9 , further comprising an oxetane compound.
14. An anisotropic conductive adhesive, comprising the thermosetting epoxy resin composition according to claim 9 , and a conductive particle dispersed in the composition.
15. A film comprising the anisotropic conductive adhesive according to claim 14 .