Method for producing microcapsules, microcapsules, recording material, and heat-sensitive recording material
View Patent ↗A microcapsule produced by a method involving a primary dispersed particle and a secondary dispersed particle, the capsule formation occurring at the interface of the secondary dispersed particle. A microcapsule containing a diazonium salt represented by a specific formula. A recording material utilizing the microcapsule.
1. A method for producing a microcapsule containing a core substance, the method comprising:
adding an oil phase solution including the core substance to an aqueous phase medium to form a first mixture;
forming a first emulsion including a primary dispersed particle by emulsifying the first mixture;
adding a wall material solution including a capsule wall material to the first emulsion so as to form a second mixture;
forming a secondary dispersed particle by emulsifying the second mixture; and
forming a capsule wall at an interface of the secondary dispersed particle.
2. A method for producing a microcapsule containing a core substance, the method comprising:
adding a wall material solution including a capsule wall material to an aqueous phase medium to form a first mixture;
forming a first emulsion including a primary dispersed particle by emulsifying the first mixture;
adding an oil phase solution including the core substance to the first emulsion so as to form a second mixture;
forming a secondary dispersed particle by emulsifying the second mixture; and
forming a capsule wall at an interface of the secondary dispersed particle.
3. The method for producing a microcapsule containing a core substance according to claim 2 , wherein the core substance includes a diazonium salt represented by the following formula (I) or (II):
wherein in the formula (I): R 1 and R 2 each independently represent an alkyl group, an alkoxy group, an alkylthio group, an arylthio group or an alkylamino group; R 3 to R 6 each independently represent a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, an aryl group, an aryloxy group, an alkylthio group, an arylthio group, an alkylamino group or a —N 2 + X − group; at least one of R 3 to R 6 represents a —N 2 + X − group; X − represents a monovalent counter anion; and Y 1 represents a sulfur atom, an oxygen atom, or a nitrogen atom bound to an alkyl group,
wherein in the formula (II): R 7 and R 8 each independently represent a hydrogen atom, an alkyl group, an alkoxy group, an aryl group, an alkylthio group, an arylthio group or an alkylamino group; R 7 and R 8 may be bound to each other to form a nitrogen-containing ring; R 9 to R 12 each independently represent a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, an aryl group, an aryloxy group, an alkylthio group, an alkylamino group or a —N 2 + X − group; at least one of R 9 to R 12 represents a —N 2 + X − group; X − represents a monovalent counter anion; and Y 2 represents a sulfur atom, an oxygen atom, or a nitrogen atom bound to an alkyl group.
4. A method for producing a microcapsule containing a core substance, the method comprising:
adding an oil phase solution including the core substance to a first aqueous phase medium to form a first mixture;
forming a first emulsion including a first primary dispersed particle of the core substance by emulsifying the first mixture;
adding a wall material solution including a capsule wall material to a second aqueous phase medium to form a second mixture;
forming a second emulsion including a second primary dispersed particle of the capsule wall material by emulsifying the second mixture;
mixing the first emulsion and the second emulsion to form a third mixture;
forming a secondary dispersed particle by emulsifying the third mixture; and
forming a capsule wall at an interface of the secondary dispersed particle,
wherein the core substance includes a diazonium salt represented by the following formula (I) or (II):
wherein in the formula (I): R 1 and R 2 each independently represent an alkyl group, an alkoxy group, an alkylthio group, an arylthio group or an alkylamino group; R 3 to R 6 each independently represent a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, an aryl group, an aryloxy group, an alkylthio group, an arylthio group, an alkylamino group or a —N 2 + X − group; at least one of R 3 to R 6 represents a —N 2 + X − group; X − represents a monovalent counter anion; and Y 1 represents a sulfur atom, an oxygen atom, or a nitrogen atom bound to an alkyl group,
wherein in the formula (II): R 7 and R 8 each independently represent a hydrogen atom, an alkyl group, an alkoxy group, an aryl group, an alkylthio group, an arylthio group or an alkylamino group; R 7 and R 8 may be bound to each other to form a nitrogen-containing ring; R 9 to R 12 each independently represent a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, an aryl group, an aryloxy group, an alkylthio group, an alkylamino group or a —N 2 + X − group; at least one of R 9 to R 12 represents a —N 2 + X − group; X − represents a monovalent counter anion; and Y 2 represents a sulfur atom, an oxygen atom, or a nitrogen atom bound to an alkyl group.