CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a national phase entry under 35 U.S.C. § 371 of International Application No. PCT/KR2018/004787 filed Apr. 25, 2018, which claims priority from Korean Patent Application No. 10-2017-0066039 filed May 29, 2017, all of which are incorporated herein by reference.

TECHNICAL FIELD

The present specification relates to an ink composition comprising a solvent containing a ketone group; and a charge transferring material or a light emitting material, and a method for manufacturing an organic light emitting device formed using the ink composition.

BACKGROUND ART

Attempts to manufacture an organic light emitting device through a solution process have been ongoing, and manufacturing an organic light emitting device using an inkjet printing process that is economical and stable has received attention as precise pattern formation has been required with minimizing material consumption, smaller devices or increased display resolution.

An ink composition used in an inkjet printing process needs to be stably discharged, needs to have no phase separation between a functional material such as a charge transfer material or a light emitting material and a solvent, and needs to form a uniform film when forming a film.

Ether-based solvents or hydrocarbon-based solvents having relatively low polarity have been much used in the ink composition in the art, and for example, solvents such as phenoxytoluene or cyclohexylbenzene have been used. However, using the above-mentioned solvent as a main solvent has had a limit in increasing a solid content of the ink due to low solubility for a functional material, which leads to a problem in that a process takes a long time, and a stable film is not able to be formed with phase separation occurring when drying. In addition, when a solvent has low solubility for a functional material, the amount of the functional material capable of being dissolved in the ink is limited, and in order to obtain a target thickness, the number of drops that need to be dropped on pixels increases, and as a result, it is difficult to obtain a flat profile, and a target thickness.

In addition, even when having high solubility for a functional material, a solvent used in an ink composition needs to have a high boiling point in order to prevent a problem of a nozzle unit being dried. For example, cyclohexanone is considered as a solvent having favorable solubility, but has a low boiling point, and therefore, is not suited in an inkjet process since a nozzle unit is dried when used in an ink composition.

Accordingly, development of an ink composition comprising a solvent having excellent solubility for functional materials and having a high boiling point has been required in the art.

DISCLOSURE

Technical Problem

The present specification is directed to providing an ink composition usable in an organic light emitting device, and a method for manufacturing an organic light emitting device using the same.

Technical Solution

One embodiment of the present specification provides an ink composition comprising a solvent comprising one or more types of the following Chemical Formulae 1 to 4; and a charge transferring material or a light emitting material.



In Chemical Formulae 1 to 4,

A1 to A10 are the same as or different from each other, and each independently hydrogen; deuterium; a hydroxyl group; a carbonyl group; an ester group; a substituted or unsubstituted alkyl group; a substituted or unsubstituted cycloalkyl group; a substituted or unsubstituted cycloalkenyl group; a substituted or unsubstituted alkoxy group; a substituted or unsubstituted aryl group; or a substituted or unsubstituted amine group, and at least one of A1 to A10 is a hydroxyl group; a carbonyl group; an ester group; a substituted or unsubstituted alkyl group; a substituted or unsubstituted cycloalkyl group; a substituted or unsubstituted cycloalkenyl group; a substituted or unsubstituted alkoxy group; a substituted or unsubstituted aryl group; or a substituted or unsubstituted amine group,

B1 to B8 are the same as or different from each other, and each independently hydrogen; deuterium; a hydroxyl group; a carbonyl group; an ester group; a substituted or unsubstituted alkyl group; a substituted or unsubstituted cycloalkyl group; a substituted or unsubstituted cycloalkenyl group; a substituted or unsubstituted alkoxy group; a substituted or unsubstituted aryl group; or a substituted or unsubstituted amine group,

C1 to C5 are the same as or different from each other, and each independently hydrogen; deuterium; a substituted or unsubstituted alkyl group; a substituted or unsubstituted cycloalkyl group; a substituted or unsubstituted cycloalkenyl group; a substituted or unsubstituted alkoxy group; or a substituted or unsubstituted aryl group,

C6 is a substituted or unsubstituted alkyl group; a substituted or unsubstituted cycloalkyl group; a substituted or unsubstituted cycloalkenyl group; a substituted or unsubstituted alkoxy group; or a substituted or unsubstituted aryl group, and

D1 is a substituted or unsubstituted aliphatic heterocyclic structure.

Another embodiment of the present specification provides a method for manufacturing an organic light emitting device comprising preparing a substrate; forming a cathode or an anode on the substrate; forming one or more organic material layers on the cathode or the anode; and forming an anode or a cathode on the organic material layers, wherein the forming of the organic material layers comprises forming one or more organic material layers using the ink composition.

Advantageous Effects

An ink composition according to one embodiment of the present specification has high solvent solubility for a functional material, and therefore, a content of the functional material can be increased in the ink composition, and as a result, an effect of shortening a process time is obtained since the number of ink drops can be reduced.

In addition, the ink composition of the present disclosure has a high boiling point, and functional material precipitation or phase separation when forming a film does not occur, and a uniform film can be formed since discharge can be stable.

