Ink composition, film using the same, and electrophoretic display device
Embodiments provide an ink composition, a film manufactured using the ink composition, and an electrophoretic display device including the film. The ink composition includes (A) a semiconductor nanorod, and (B) a dispersion medium, wherein the dispersion medium includes: (B1) a compound which has a viscosity at 25° C. of 70 cps or less and has a dielectric constant of 5 or more; (B2) a compound which has a viscosity at 25° C. of 80 cps or more or is a solid and has a dielectric constant of 5 or more; (B3) a compound which has a viscosity at 25° C. of 20 cps or more or is a solid and has a dielectric constant of less than 5; and (B4) a compound which has a viscosity at 25° C. of 12 cps or less or is a solid and has a dielectric constant of 4 to 7.5.
1 . An ink composition comprising:
a semiconductor nanorod; and
a dispersion medium, wherein
the dispersion medium includes:
a compound which has a viscosity at 25° C. equal to or less than about 70 cps and has a dielectric constant equal to or greater than about 5 and includes a compound represented by one of Formulae 1-1 to 1-5;
a compound which has a viscosity at 25° C. equal to or greater than about 80 cps or is a solid and has a dielectric constant equal to or greater than about 5 and includes a compound represented by one of Formulae 2-1 to Formula 2-7;
a compound which has a viscosity at 25° C. equal to or greater than about 20 cps or is a solid and has a dielectric constant of less than about 5 and includes a compound represented by one of Formulae 3-1 to Formula 3-3; and
a compound which has a viscosity at 25° C. equal to or less than about 12 cps or is a solid and has a dielectric constant in a range of about 4 to about 7.5 and includes a compound represented by one of Formulae 4-1 to Formula 4-3,
wherein in Formulae 1-1 to 1-5,
R 1 to R 3 and R 6 are each independently a substituted or unsubstituted C1 to C20 alkyl group,
R 4 is a C1 to C20 alkyl group substituted by a hydroxyl group,
R 5 is a substituted or unsubstituted C2 to C20 alkyl group,
L 1 to L 3 are each independently a substituted or unsubstituted C1 to C20 alkylene group, and
n is an integer from 1 to 10,
wherein in Formulae 2-1 to 2-7,
R 7 , R 8 , and R 11 to R 16 are each independently a substituted or unsubstituted C1 to C20 alkyl group,
R 9 and R 10 are each independently a C1 to C20 alkyl group substituted by a hydroxyl group, and
L 1 , L 2 and L 4 are each independently a substituted or unsubstituted C1 to C20 alkylene group,
wherein in Formulae 3-1 to 3-3,
R 17 to R 19 are each independently a substituted or unsubstituted C1 to C10 alkyl group, and
L 5 to L 7 are each independently a substituted or unsubstituted C1 to C20 alkylene group,
and
wherein in Formulae 4-1 to 4-3,
R 20 to R 23 are each independently of a substituted or unsubstituted C1 to C10 alkyl group, and
L 8 and L 9 are each independently of a substituted or unsubstituted C1 to C20 alkylene group.
2 . The ink composition of claim 1 , wherein the dispersion medium includes, with respect to a total amount of the dispersion medium:
about 10 wt % to about 30 wt % of the compound which has a viscosity at 25° C. equal to or less than about 70 cps and has a dielectric constant equal to or greater than about 5;
about 20 wt % to about 40 wt % of the compound which has a viscosity at 25° C. equal to or greater than about 80 cps or is a solid and has a dielectric constant equal to or greater than about 5;
about 10 wt % to about 30 wt % of the compound which has a viscosity at 25° C. equal to or greater than about 20 cps or is a solid and has a dielectric constant of less than about 5; and
about 20 wt % to about 50 wt % of the compound which has a viscosity at 25° C. equal to or less than about 12 cps or is a solid and has a dielectric constant in a range of about 4 to about 7.5.
3 . The ink composition of claim 1 , wherein
the compound which has a viscosity at 25° C. equal to or less than about 70 cps and has a dielectric constant equal to or greater than about 5 has a viscosity at 50° C. equal to or less than about 50 cps.
4 . The ink composition of claim 1 , wherein
the compound which has a viscosity at 25° C. equal to or greater than about 80 cps or is a solid and has a dielectric constant equal to or greater than about 5 has a viscosity at 50° C. equal to or less than about 10 cps or is a solid.
5 . The ink composition of claim 1 , wherein
the compound which has a viscosity at 25° C. equal to or greater than about 20 cps or is a solid and has a dielectric constant of less than about 5 has a viscosity at 50° C. equal to or greater than about 5 cps.
6 . The ink composition of claim 1 , wherein
the compound which has a viscosity at 25° C. equal to or less than about 12 cps or is a solid and has a dielectric constant in a range of about 4 to about 7.5 has a viscosity at 50° C. equal to or greater than about 1 cps.
7 . The ink composition of claim 1 , wherein the semiconductor nanorod has a diameter in a range of about 300 nm to about 900 nm.
8 . The ink composition of claim 1 , wherein the semiconductor nanorod has a length in a range of about 3.5 μm to about 5 μm.
9 . The ink composition of claim 1 , wherein the semiconductor nanorod includes a GaN-based compound, an InGaN-based compound, or a combination thereof.
10 . The ink composition of claim 1 , wherein the semiconductor nanorod has a surface coated with a metal oxide.
11 . The ink composition of claim 10 , wherein the metal oxide includes alumina, silica, or a combination thereof.
12 . The ink composition of claim 1 , wherein an amount of the semiconductor nanorod is in a range of about 0.01 wt % to about 10 wt % with respect to the total amount of the ink composition.
13 . The ink composition of claim 1 , further comprising:
malonic acid, 3-amino-1,2-propanediol, a silane-based coupling agent, a leveling agent, a fluorine-based surfactant, or a combination thereof.
14 . A film manufactured using the ink composition of claim 1 .
15 . An electrophoretic display device comprising the film of claim 14 .
16 . An ink composition comprising:
a semiconductor nanorod; and
a dispersion medium, wherein
the dispersion medium includes:
a compound which has a viscosity at 25° C. equal to or less than about 70 cps and has a dielectric constant equal to or greater than about 5 and includes a compound represented by Formula 1-1;
a compound which has a viscosity at 25° C. equal to or greater than about 80 cps or is a solid and has a dielectric constant equal to or greater than about 5 and includes a compound represented by Formula 2-7;
a compound which has a viscosity at 25° C. equal to or greater than about 20 cps or is a solid and has a dielectric constant of less than about 5 and includes a compound represented by Formula 3-2; and
a compound which has a viscosity at 25° C. equal to or less than about 12 cps or is a solid and has a dielectric constant in a range of about 4 to about 7.5 and includes a compound represented by Formula 4-1,
wherein in Formula 1-1,
R 1 to R 3 are each independently a substituted or unsubstituted C1 to C20 alkyl group, and
L 1 to L 2 are each independently a substituted or unsubstituted C1 to C20 alkylene group,
wherein in Formula 2-7,
R 15 and R 16 are each independently a substituted or unsubstituted C1 to C20 alkyl group,
wherein in Formula 3-2,
R 17 to R 19 are each independently a substituted or unsubstituted C1 to C10 alkyl group,
and
wherein in Formulae 4-1,
R 20 to R 21 are each independently of a substituted or unsubstituted C1 to C10 alkyl group, and
L 8 is a substituted or unsubstituted C1 to C20 alkylene group.
17 . The ink composition of claim 16 , wherein an amount of the semiconductor nanorod is in a range of about 0.01 wt % to about 10 wt % with respect to the total amount of the ink composition.
18 . The ink composition of claim 16 , further comprising:
malonic acid, 3-amino-1,2-propanediol, a silane-based coupling agent, a leveling agent, a fluorine-based surfactant, or a combination thereof.
19 . A film manufactured using the ink composition of claim 16 .
20 . An electrophoretic display device comprising the film of claim 19 .