Method for producing hydrogel microcapsules, kit for producing capsules, and use therefor

A method for producing a hydrogel capsule including (i) a core containing an ionically-bonded polymer and (ii) a shell containing a thermoresponsive polymer,

• said method comprising:
• (a) cooling a suspension so as to gel the thermoresponsive polymer and form the shell, the suspension being obtained by suspending, in a first oil phase, a sol (aqueous phase) of the thermoresponsive polymer including a core at least a surface of which is formed from a gel of the ionically-bonded polymer,
• oil, contained in the first oil phase, having a hydrophobicity, as measured by an octanol-water partition coefficient (LogPow), of not less than 3 and having a specific gravity and a viscosity that satisfy the following formula:
• ρ
• p
• -
• ρ
• f
• ≤
• 18
• ⁢
• (
• 100
• -
• x
• )
• ⁢
• L
• 100
• ⁢
• tD
• p
• 2
• ⁢
• g
• ⁢
• η
• wherein ρp represents an average specific gravity [kg/m3] of an ionically-bonded polymer gel and a thermoresponsive polymer sol;
• πr represents an oil specific gravity [kg/m3];
• x represents a yield [%] obtained in a step of producing the hydrogel capsule;
• L represents a depth [m] of the suspension that is contained in a vessel;
• t represents a gelling time [s] of the thermoresponsive polymer;
• Dp represents a diameter [m] of the hydrogel capsule;
• g represents gravitational acceleration [m/s2];
• and n represents an oil viscosity [Pa·s].