Ink composition for organic electroluminescent device and production method thereof

1. An ink for organic EL devices comprising:

a polymer organic EL material prepared by a coupling reaction between a halogenated aromatic compound and an aromatic boron compound in the presence of a palladium catalyst or a nickel catalyst;

an organic solvent;

an aromatic carboxylic acid having a boiling point of 200-270° C.; and

an ester derivative of the aromatic carboxylic acid,

wherein the aromatic carboxylic acid and the ester derivative are contained in an amount of 0.01-1 wt % based on the total amount of the organic solvent, the aromatic carboxylic acid and the ester derivative.

2. A manufacturing method of an organic EL device comprising:

applying the ink according to claim 1 on a pixel electrode or either a hole injection/transport layer or an intermediate layer deposited on the pixel electrode; and

drying the ink applied.

3. A manufacturing method of an organic EL device comprising: preparing an ink by applying an electric field to a composition containing

i. a polymer organic EL material prepared by a coupling reaction between a halogenated aromatic compound and an aromatic boron compound in the presence of a palladium catalyst or a nickel catalyst;

ii. an organic solvent; and

iii. an aromatic carboxylic acid, the aromatic carboxylic acid being contained in an amount of 0.01-1 wt % based on the total amount of the organic solvent and the aromatic carboxylic acid

in a container equipped with a pair of electrodes;

applying the prepared ink with an applicator on a pixel electrode or either a hole injection/transport layer or an intermediate layer deposited on the pixel electrode; and

drying the applied ink.

4. The method according to claim 3 , wherein the intensity of the electric field is 3-10 kV/mm.

5. The method according to claim 3 , wherein the polymer organic EL material is a polymer material containing a repeating unit having the following General Formula (a1):

where R denotes a hydrogen atom or an alkyl group having 1-4 carbon atoms, and R 1 denotes a hydrogen atom, an alkyl group having 1-4 carbon atoms, an aryl group, or an alkylaryl group.

6. The method according to claim 3 , wherein the aromatic carboxylic acid is a compound having the following General Formula (c10) or General Formula (c11):

where R 10 s independently denote a hydrogen atom, an alkyl group having 1-12 carbon atoms, an alkoxy group having 1-12 carbon atoms, alkoxyalkyl group having 1-12 carbon atoms, or a 5- to 7-membered heterocyclic ring;

where Ar 10 denotes an aryl group or an alkylaryl group, and X denotes a single bond, an alkylene group having 1-3 carbon atoms, or —CH 2 —O—CH 2 —.

7. The method according to claim 3 , wherein the aromatic carboxylic acid has a boiling point of 200-270° C.

8. The method according to claim 3 , further comprising loading the prepared ink in the applicator prior to applying the prepared ink.