Method for coating a surface of a component

Abstract

The invention relates to a method for coating a surface (44), in particular a microstructured surface, of a component (55) comprising different materials, in particular glass and silicon, wherein the surface (44) is first activated and then coated, wherein an oxidising solution, a basic solution or an acid-oxidising solution is used to activate the surface (44).

Claims

1. A method for preparing a nebulizer, the method comprising: coating a microstructured surface within a component comprising glass and silicon, wherein the component consists of a plate of glass and a plate of silicon firmly joined together and at least one of the plates has one or more microstructured channels, wherein the surface is first activated and then coated, characterized in that: an oxidizing solution, a basic solution or an acid-oxidizing solution is used to activate the surface, before the activation the surface is cleaned, and coating the surface comprises: applying a reaction solution to coat the microstructured channels, the reaction solution comprising functional silanes in non-polar, aprotic or polar-protic solvents, and treating the microstructured surface with ultrasound during application of the reaction solution, wherein the ultrasound treatment causes flow of the reaction solution into the microstructured channels; and incorporating the component into a medical device configured to nebulize a liquid medicament passed through the one or more microstructured channels.

2. The method according to claim 1, characterized in that the coated component is washed.

3. The method according to claim 1, wherein the oxidizing solution which is used for activating the surface is a solution consisting of water, ammonia solution, containing 25% ammonia, and hydrogen peroxide solution, containing 30% hydrogen peroxide, in the ratio 5:1:1.

4. The method according to claim 1, wherein a piranha solution is used as an acid-oxidizing solution for activating the surface.

5. The method according to claim 1, wherein before the activation the surface is cleaned using isopropanol and water.

6. The method according to claim 1, wherein for coating the surface, perfluoroalkylsilanes or alkylsilanes are used.

7. The method according to claim 6, wherein for coating the surface perfluoroalkl silanes or trialkoxysilanes are used.

8. The method according to claim 1, wherein for coating the surface, trihalosilanes, monohalodimethylsilanes or trialkoxysilanes are used.

9. The method according to claim 8, wherein dimethylmonochlorosilanes in dry non-polar, aprotic solvents are used for coating.

10. The method according to claim 9, wherein for coating the component is immersed in a solution of dimethylmonochlorosilanes and then dried in a nitrogen current.

11. The method according to claim 8, wherein a solution of trialkoxysilanes is used for coating.

12. The method according to claim 11, wherein a 0.1 to 1% solution of functional triethoxysilanes in 2-ropanol/water/hydrochloric acid is stirred for about five hours and the component with its activated surfaces is then immersed in the solution.

13. The method according to claim 11, wherein after the component has been taken out of the solution, the excess solution is removed from the component by allowing it to drip.

14. The method according to claim 11, wherein the trialkoxysilanes used are trimethoxysilanes or triethoxysilanes.

15. The method according to claim 1, wherein after the coating the component is heat-treated.

16. The method according to claim 15, wherein after the coating the component is heat-treated for 1 to 2 hours at 120 C.

17. The method according to claim 1, wherein the reaction solution forms a coating layer on the one or more microstructured channels, and wherein the coating layer inhibits accumulation of a liquid medicament within the one or more microstructured channels.

Description

(1) The invention is hereinafter described in more detail by means of an embodiment by way of example, by reference to the attached drawings, wherein:

(2) FIG. 1 is a longitudinal section through a nebuliser according to the invention with a tensioned spring,

(3) FIG. 2 is a longitudinal section through the nebuliser according to FIG. 1 with the spring relaxed,

(4) FIG. 3 is a perspective view of a component according to the invention,

(5) FIG. 4 is a front view of the component according to FIG. 3 and

(6) FIG. 5 is a magnified partial representation of the component according to FIG. 3.

(7) An upper housing part 51 of the nebuliser comprises a pump housing 52 on the end of which is mounted a holder 53 for a nebuliser nozzle. In the holder 53 is a recess 54 that widens outs and the component 55 in the form of a nozzle body. A hollow piston fixed in a power take-off flange 56 of a locking clamping mechanism projects partly into a cylinder of the pump housing 52. At its end the hollow piston 57 carries a valve body 58. The hollow piston 57 is sealed off by a gasket 59. Inside the upper housing part 51 is a stop 60 of the power take-off flange 56 on which a compression spring 68 rests. After the tensioning of the compression spring 68 a locking member 62 slides between a stop 61 on the power take-off flange 56 and a support 63 in the upper housing part 51. An actuating button 64 is connected to the locking member 62. The upper housing part 51 ends in a mouthpiece 65 and is closed off by a removable protective cap 66.

(8) A spring housing 67 with the compression spring 68 is rotatably mounted on the upper housing part 51 by means of snap-fit lugs 69 and a rotary bearing. A lower housing part 70 is pushed over the spring housing 67 and inside the spring housing 67 is a storage container 71 for fluid 72 which is to be nebulised. The storage container 71 is closed off by a stopper 73 through which the hollow piston 57 projects into the storage container 71 and dips its end into the fluid 72, i.e. the supply of active substance solution.

(9) A spindle 74 for a mechanical counter (optional) is provided in an outer surface of the spring housing 67. A drive pinion 75 is located at the end of the spindle 74 facing the upper housing part 51. On the spindle 74 is a slider 76.

(10) The component 55a so-called uniblockcomprises two plates 40, 41 firmly joined together, of which one plate 40 is made of silicon and has a microstructure 42 for forming a channel or filter system and an adjacent nozzle opening 43. The silicon plate 40 is firmly attached to the glass plate 41 on the side having the microstructure 42.

(11) At least the surface 44 of the microstructure 42 has a coating consisting of functional silanes which prevents any interaction of ingredients and particles of the formulation expelled through the nozzle opening 43 with the interfaces of the component 55. During the use of the nebuliser comprising the component 55, the material residues are expelled from the component 55 and the coated component 55 is self-cleaning thanks to the use of the monomolecular, covalently bound non-stick coating.

(12) The surfaces 44 of the component 55, particularly the microstructure 42, are first cleaned by dipping the component 5 first into isopropanol for five minutes and then into water for five minutes. Then the component 55 is bathed for about 20 minutes in an aqueous 3% hydrofluoric acid solution (HF).

(13) The activation of the surface 44 itself is carried out using a cell cleaner, particularly the cell or glass cleaner known by the brand name Hellmanex solution and produced by Hellma GmbH & Co. KG, of Mllheim, Germany, as an aqueous 2% solution, at 70 C. for 220 minutes in an ultrasound bath.

(14) For functionalisation, 1H,1H,2H,2H-perfluorooctyltriethoxysilane is used, for example, which is marketed for example under the brand name Dynasylan by Evonik AG of Dsseldorf. After the component 55 has been exposed for about two hours to a solution containing the functional silane under the effect of ultrasound, the excess solution is allowed to drip off the component 55 and the component is treated for about one to two hours at 120 C. in an oven. After the heat treatment any excess and non-covalently bound residues are washed off the component 55 using isopropanol and water.