Receptacle comprising a formulation containing at least one organic semiconductor

Abstract

The present invention relates to vessels comprising a formulation including at least one organic semiconductor, wherein the formulation is in contact with at least one absorption material. The invention further describes a process for producing the vessel and for the use thereof.

Claims

1. An ink reservoir vessel comprising a formulation including one or more organic semiconductors dissolved or dispersed in a solvent or dispersant, wherein the formulation is in contact with at least one absorption material.

2. The ink reservoir vessel according to claim 1, wherein the absorption material can bind oxygen, water and/or hydroxide ions or can react with these substances.

3. The ink reservoir vessel according to claim 1, wherein the absorption material is selected from alkali metals or alkaline earth metals.

4. The ink reservoir vessel according to claim 1, wherein the absorption material takes the form of a film, a powder, a granular material, having particle sizes in the range from 1 m to 5 mm, and/or of a shaped body.

5. The ink reservoir vessel according to claim 1, wherein the absorption material is porous or particulate.

6. The ink reservoir vessel according to claim 1, wherein the absorption material is in direct contact with the formulation.

7. The ink reservoir vessel according to claim 1, wherein the absorption material has been embedded into a polymer material.

8. The ink reservoir vessel according to claim 7, wherein the polymer film surrounds the absorption material, such that the polymer film forms a pouch, container or shell within which the absorption material is present.

9. The ink reservoir vessel according to claim 7, wherein the polymer material or polymer film contains the absorption material in such a way that polymer material and absorption material are in a mixture and the absorption material is homogeneously distributed in the polymer film or polymer material.

10. The ink reservoir vessel according to claim 7, wherein the polymer material is a polymer film which has a permeability with respect to oxygen, water and/or hydroxide ions of at least 0.001 g/(m.sup.2 d) (grams per square metre and day), measured by means of diffusion measurement.

11. The ink reservoir vessel according to claim 7, wherein the weight ratio of absorption material to polymer material, preferably polymer film, is in the range from 500:1 to 1:500.

12. The ink reservoir vessel according to claim 1, wherein the vessel is a printer cartridge.

13. The ink reservoir vessel according to claim 12, wherein the printer cartridge has a housing into which there has been introduced an inner pouch within which the formulation including at least one organic semiconductor is present.

14. The ink reservoir vessel according to claim 13, wherein the inner pouch is formed from a multilayer film impermeable to oxygen, water, carbon dioxide and/or hydroxide ions.

15. The ink reservoir vessel according to claim 12, wherein a layer comprising an absorption material has been applied at least to part of the inner surface of the inner pouch and/or the absorption material has been introduced into an inner layer of the inner pouch.

16. The ink reservoir vessel according to claim 12, wherein the printer cartridge has a valve, with the absorption material fixed close to the valve.

17. The ink reservoir vessel according to claim 1, wherein the organic semiconductor is selected from host materials, matrix materials, electron transport materials, electron injection materials, hole conductor materials, hole injection materials, electron blocker materials and hole blocker materials.

18. A process for producing the ink reservoir vessel according to claim 1, wherein a vessel is filled with a formulation comprising at least one organic semiconductor and contacted with at least one absorption material.

19. The ink reservoir vessel according to claim 1, wherein the absorption material is selected from aluminum oxide, titanium oxide, zirconium oxide, silicon oxide, zeolites, silica gels or aluminosilicates; or zirconium, vanadium, cobalt, iron, manganese, copper or zinc, or the oxides thereof, and combinations, mixtures or alloys of these materials.

Description

EXAMPLE 1

(1) Modified Printer Cartridge for the Printing of OLED Materials:

(2) For the printing of OLED components, inkjet methodology is used. For the printing of the individual layers of the desired component, a commercially available industrial inkjet printer from Dimatix is used. The ink is supplied using industry-standard printer cartridges. The cartridges used consist of an outer plastic vessel within which a multilayer film pouch containing the printer ink has been embedded. The multilayer film pouch consists of an inner polyethylene film having a thickness of 100 micrometres, to which a thin aluminium layer of 15 micrometres has been applied, and an outer PET film having layer thickness 40 micrometres, and interlayers to bind the films. A valve in the film pouch can be used to introduce the ink and withdraw it for operation of the printer. The printer cartridges available as industry standard are optimized for the utilization of water-based printing inks and are therefore inadequate to assure the quality of the sensitive materials dissolved in organic solvents for the production of OLED components.

(3) According to the invention, the printer cartridge is modified as follows. In the production of the multilayer film pouch present within the printer cartridge, a metal strip of calcium or lithium or a combination of the two is incorporated. In the preferred execution, a calcium metal strip of thickness 50 m and width 2 cm is incorporated by lamination between the aluminium layer and the inner PE film of the inner pouch of the cartridge in a dry atmosphere. The film pouch is then manufactured from the film thus processed, in such a way that the calcium strip with the PE film thereon is directed to the inside of the film pouch. The film pouch used had a capacity of 100 milliliters. This film pouch is then, in the customary manner, provided with the valve and incorporated into the printer cartridge and filled with ink.

(4) The cartridge thus modified, filled with an ink mixture, was used to conduct storage tests compared to storage in an unmodified cartridge. For this purpose, two ink mixtures which are utilized for the production of OLED components were used (MHL3-0119 and MBL3-6620 from Merck). Storage was effected at room temperature for 14 months.

(5) The following results were achieved compared to the starting values:

(6) TABLE-US-00001 Ink mixture Cartridge/storage Oxygen content Water content MHL3-0119 after production 100% 100% 14 months, 150% 204% unmodified cartridge 14 months, 110% 111% cartridge modified with Ca film MBL3-6620 after production 100% 100% 14 months, 250% 166% unmodified cartridge 14 months, 140% 108% cartridge modified with Ca film

(7) After storage for 14 months at room temperature, the starting values for oxygen content and water content are distinctly exceeded in the unmodified printer cartridge. The modification of the cartridge in accordance with the invention causes the rise in oxygen and water content to be much smaller.

EXAMPLE 2

(8) Modified Reservoir Vessels for Inks in Organic Electronics and for Organic Solar Cells:

(9) In the production of components in organic electronics or solar cells, containers of the Nowpak brand (Entegris) have become established. The containers are metal flasks provided with an inliner film pouch made of PTFE. Such a flask is modified in accordance with the invention in such a way that an absorber material is introduced into the interspace between the inner wall of the metal flask and the PTFE film pouch. The amount of the absorber material should be about 1% by weight of the contents of the vessel. The absorption material is produced by vigorously mixing a commercially available dried silica gel with a calcium powder in a ratio of 10:1 in a dry atmosphere in a glovebox. Immediately after production, the absorber material thus produced is introduced under a dry atmosphere into the interspace between the metal wall and inliner pouch of the flask to be modified. In the example, a flask having a capacity of 1000 ml (flask of the Nowpak brand from Entegris) was used.

(10) The flask that has been modified in this way, prior to filling, is stored in a dry atmosphere in a glovebox and then filled with the desired ink in the customary manner and examined. The flask thus modified can then be used in a customary manner in unchanged form for the production of components for organic electronics, of OLED components or organic solar cells, for example by means of spin-coating.

(11) In the example, an ink consisting of a hole transport material (HTM-081, Merck) dissolved in a concentration of 5 grams per litre in toluene was used. The mixture was produced in a dry atmosphere in a glovebox and, after production, had an oxygen content of <4 ppm and a water content of <200 ppm, measured by Karl Fischer titration.

(12) After the filling of the flask modified by means of absorbers with 1000 ml of ink solution, the flask was first stored outside the glovebox at room temperature for one week and then for 2 months. One week after the filling, the water content measured in the samples fell by 10-20%. The oxygen content remained below the detection limit of 4 ppm. After storage for a further two months, no detectable rise in respect of water and oxygen content was observable.

EXAMPLE 3

(13) Supply Vessel for the Printing of Organic Functional Inks and OLED Inks

(14) For use in large production plants, for the supply of inks, a stainless steel vessel having a vessel volume of 1 to 200 litres or even greater was used. As an example, a 30 litre stainless steel vessel was used. The vessel has a lid screwed onto the vessel with a seal. This lid has been provided not only with a safety valve and optionally measurement devices but also with two pipe leadthroughs each having a diameter of 10 mm in the example, equipped with stainless steel pipes. One pipe reaches to just above the base of the vessel and serves for withdrawal of the liquid from the vessel. The second pipe ends just below the lid and allows the filling of the vessel. The two pipes are each sealed with a valve above the lid and are provided with connections which can be attached to the standard filling or withdrawal devices. According to the invention, an absorber material is introduced into this supply vessel. In Example 3a), the absorber material is introduced into a porous PTFE pouch. The maximum pore size of the PTFE used for the pouch should be 100 nm. The pouch is filled with the absorber material in a dry atmosphere and sealed, and, after the cleaning and drying of the supply vessel, inserted into the vessel in the dry state, before the lid of the vessel is mounted together with the filling and withdrawal pipe. Thereafter, the ink is introduced and thus comes into direct contact with the pouch comprising the absorber material and can also penetrate the latter because of its porosity. Thus, the absorber material comes into direct contact with the printing ink introduced.

(15) In Example 3b), the absorber material is introduced in another way. The absorber material is introduced into a stainless steel pipe which, after being filled, is sealed with a membrane filter at either end. The pipe comprising the absorber material is connected to the filling tube in the vessel in the dry state, such that the ink flows into the tube comprising the absorber material during the filling at first via the filling pipe and the first of the two membrane filters, in order then to pass through the second filter into the remaining inner volume of the vessel. During the filling, the ink introduced flows all the way around the pipe comprising the absorber material, and the pipe remains in contact with the ink during the storage and transport. Membrane filters used are commercially available membrane filters from Entegris. The absorber material used is ultrapure alumina, for example in an amount of 8% by weight, based on the fill volume of the vessel. The vessel is filled with a hole conductor ink as used for the production of OLEDs or else for components for organic electronics. In the example, a Merck ink with the name MHL3-0119 was used. After preparation of the vessels as described in Examples 3a) and 3b), the vessels were each filled with 30 litres of the ink.

(16) After the filling and after a storage time of 2 months, the water content of the ink was determined and compared to the starting value. The following results were achieved:

(17) TABLE-US-00002 Water content in the Water content in the vessel according to vessel according to Storage time Example 3a) Example 3b) Before filling 120 ppm 120 ppm Immediately after filling not determined 40 ppm One week after filling 52 ppm not determined After storage time of 2 60 ppm 57 ppm months

(18) After a prolonged storage time of up to 6 months, no significant rise in the water content beyond the measurement accuracy of the Karl Fischer test method used was observed.