Formulation of an organic functional material

Patent metadata

Field	Value
Publication number	US-11603479-B2
Application number	US-201917252376-A
Country	US
Kind code	B2
Filing date	Jun 12, 2019
Priority date	Jun 15, 2018
Publication date	Mar 14, 2023
Grant date	Mar 14, 2023

Abstract

The present invention relates to a formulation containing at least one organic functional material and at least three different organic solvents, selected from at least two different organic solvents A and at least one organic solvent B, wherein at least one organic solvent A has a boiling point in the range from 250 to 350° C. and a viscosity of ≥15 mPas, the at least one organic solvent B has a boiling point in the range from 200 to 350° C. and a viscosity of ≤10 mPas, and the solubility of the at least one organic functional material in the second organic solvent B is ≥5 g/l; as well as to electroluminescent devices prepared by using these formulations.

First claim

The invention claimed is:

1. A formulation containing at least one organic functional material and at least three different organic solvents, selected from at least two different organic solvents A and at least one organic solvent B, wherein
at least two of the organic solvents A have a viscosity of ≥15 mPas, and wherein at least two of the organic solvents A is selected from naphthalene derivatives, partially hydrogenated naphthalene derivatives, and fully hydrogenated naphthalene derivatives,
the organic solvent B has a viscosity of ≤10 mPas,
wherein at least two of the organic solvents A have a boiling point in the range from 300° C. to 350° C. and the organic solvent B has a boiling point in the range from 200° C. to 300° C., and
the solubility of the at least one organic functional material in the organic solvent B is ≤5 g/l.

2. The formulation according to claim 1 , wherein the total content of the at least two organic solvents A is in the range from 0.1 to 50 vol.-%, based on the total amount of solvents in the formulation.

3. The formulation according to claim 1 , wherein at least one of the organic solvents A has a boiling point in the range from 300 to 340° C.

4. The formulation according to claim 1 , wherein at least one of the organic solvents A has a viscosity of ≥20 mPas.

5. The formulation according to claim 1 , wherein the content of the at least one organic solvent B is in the range from 50 to 99.9 vol.-%, based on the total amount of solvents in the formulation.

6. The formulation according to claim 1 , wherein the at least one organic solvent B has a boiling point in the range from 225 to 300° C.

7. The formulation according to claim 1 , wherein formulation comprises at least one organic solvent C, which is different from the at least two organic solvents A and the at least one organic solvent B.

8. The formulation according to claim 7 , wherein the boiling point of the at least one solvent C is lower than the boiling point of the at least one organic solvent B.

9. The formulation according to claim 1 , wherein the formulation has a surface tension in the range from 10 to 70 mN/m.

10. The formulation according to claim 1 , wherein the formulation has a viscosity in the range from 0.8 to 50 mPas.

11. The formulation according to claim 1 , wherein the content of the at least one organic functional material in the formulation is in the range from 0.001 to 20 weight-%, based on the total weight of the formulation.

12. The formulation according to claim 1 , wherein the at least one organic functional material is selected from the group consisting of organic conductors, organic semiconductors, organic fluorescent compounds, organic phosphorescent compounds, organic light-absorbent compounds, organic light-sensitive compounds, organic photosensitisation agents and other organic photoactive compounds such as organometallic complexes of transition metals, rare earths, lanthanides, and actinides.

13. The formulation according to claim 12 , wherein the at least one organic functional material is selected from the group consisting of fluorescent emitters, phosphorescent emitters, host materials, matrix materials, exciton-blocking materials, electron-transport materials, electron-injection materials, hole-conductor materials, hole-injection materials, n-dopants, p-dopants, wide-band-gap materials, electron-blocking materials, and hole-blocking materials.

14. The formulation according to claim 13 , wherein the at least one organic functional material is an organic semiconductor selected from the group consisting of hole-injecting, hole-transporting, emitting, electron-transporting and electron-injecting materials.

15. The formulation according to claim 14 , wherein the at least one organic semiconductor is selected from the group consisting of hole-injecting, hole-transporting, and emitting materials.

16. The formulation according to claim 14 , wherein the hole-injecting and hole-transporting material is a polymeric compound or a blend of a polymeric compound and a non-polymeric compound.

17. The formulation according to claim 14 , wherein the at least one emitting material is a mixture of two or more different compounds having a low molecular weight.

18. A process for the preparation of a formulation according to claim 1 , wherein the at least one organic functional material and the at least three different solvents are mixed.

19. A process for the preparation of an electroluminescent device, wherein at least one layer of the electroluminescent device is prepared in that a formulation according to claim 1 is deposited on a surface and subsequently dried.

Assignees

• Merck Patent Gmbh
• Merck Kgaa

Inventors

• Béalle Gaëlle
• Leonhard Christoph
• Tseng Hsin-Rong
• Hamburger Manuel
• Wucherer-Plietker Margarita

Classifications

• H10K71/135

  using ink-jet printing · CPC title

• H10K50/17

  Carrier injection layers · CPC title

• C09D11/52

  Electrically conductive inks · CPC title

• C09D11/36 Primary

  based on non-aqueous solvents · CPC title

• H10K71/15

  characterised by the solvent used · CPC title