Method for manufacturing quantum dot film comprising encapsulated quantum dots uniformly dispersed therein, quantum dot film manufactured thereby and wavelength conversion sheet and display comprising same
The present invention relates to a method of manufacturing a quantum-dot film having encapsulated quantum dots dispersed therein, in which quantum dots are uniformly dispersed in a matrix resin to thus increase quantum yield and in which deterioration of the quantum dots can be prevented through encapsulation, a quantum-dot film manufactured thereby, and a wavelength conversion sheet and a display including the same.
1. A method of manufacturing a quantum-dot film, suitable for manufacturing a quantum-dot film in which encapsulated particles obtained by encapsulating quantum dots with an encapsulation resin are dispersed in a matrix resin, the method comprising sequential steps of:
(a) preparing a curable emulsion composition comprising an inner phase, comprising an encapsulation resin in liquid state and quantum dots dispersed in the encapsulation resin, and an outer phase in liquid state, comprising a photocurable polymerization compound and a photoinitiator, the inner phase being dispersed in a droplet form in the outer phase; and then
(b) independently performing encapsulation of the inner phase and curing of the outer phase using the curable emulsion composition,
wherein the encapsulation resin is a thermally curable resin or a wax-based compound, and
wherein the step (b) is performed in a manner in which the inner phase is first cured or solidified and then the outer phase is cured, or the outer phase is first cured and then the inner phase is cured or solidified.
2. The method of claim 1 , wherein the encapsulation resin is a thermally curable resin, and
the quantum dots of the inner phase are encapsulated with the encapsulation resin by applying heat, and then the photocurable polymerization compound of the outer phase is cured through light irradiation.
3. The method of claim 1 , wherein the encapsulation resin is a thermally curable resin, and
the photocurable polymerization compound of the outer phase is cured through light irradiation, and then the quantum dots of the inner phase are encapsulated with the encapsulation resin by applying heat.
4. The method of claim 1 , wherein the encapsulation resin is a wax-based compound, and
a temperature of the curable emulsion composition is lowered to a temperature equal to or lower than a melting point of the wax-based compound so that the quantum dots of the inner phase are encapsulated with the encapsulation resin, and the photocurable polymerization compound of the outer phase is cured through light irradiation.
5. The method of claim 4 , wherein the curable emulsion composition is prepared in a manner in which the quantum dots and the encapsulation resin are mixed at a temperature equal to or higher than the melting point of the wax-based compound to afford an inner phase, and the inner phase and the outer phase are mixed at a temperature equal to or higher than the melting point of the wax-based compound.
6. The method of claim 1 , wherein the thermally curable resin is a liquid resin that remains liquid at room temperature.
7. The method of claim 1 , wherein the thermally curable resin comprises at least one selected from the group consisting of a silicone-based resin, an epoxy resin, a petroleum resin, a phenol resin, a urea resin, a melamine resin, an unsaturated polyester resin, an amino resin, butyl rubber, isobutylene rubber, acrylic rubber, and urethane rubber.
8. The method of claim 1 , wherein the wax-based compound is at least one selected from the group consisting of petroleum wax, natural animal wax, natural vegetable wax, and synthetic wax.
9. The method of claim 1 , wherein the photocurable polymerization compound is any one selected from the group consisting of an acrylic oligomer, an acrylic monomer and combinations thereof.
10. The method of claim 1 , wherein the photoinitiator is at least one selected from the group consisting of a benzoin photoinitiator, a hydroxyketone photoinitiator, an aminoketone photoinitiator, and a phosphine oxide photoinitiator.
11. The method of claim 1 , wherein at least one of the inner phase and the outer phase in the curable emulsion composition further comprises any one selected from the group consisting of ceramic nanoparticles, a crosslinking agent, a catalyst, a surfactant, and a solvent.
12. The method of claim 11 , wherein the ceramic nanoparticles are at least one selected from the group consisting of silica, alumina, titania, zirconia, tungsten oxide, zinc oxide, and Si3N4.
13. The method of claim 1 , wherein the quantum dots are further subjected to primary coating with any one encapsulation resin selected from among a thermally curable resin and a wax-based compound.