PECVD lubricity vessel coating, coating process and apparatus providing different power levels in two phases

• US 9,863,042 B2
• Filed: 03/14/2014
• Issued: 01/09/2018
• Est. Priority Date: 03/15/2013
• Status: Active Grant

• Current Assignee: SiO2 Medical products Inc.
• Original Assignee: SiO2 Medical products Inc.
• Inventors: Jones, Joseph A., Felts, John T., Gresham, James Troy, Lilly, Brian Russell, Fisk, Thomas E.
• Primary Examiner(s): VASISTH, VISHAL V
• Application Number:
  US14/214,030
• Publication Number:
  US 20140274825A1
• Time in Patent Office: 1,397 Days
• Field of Search: 508107, 118697, 118723 R, 427 23, 427578
• CPC Class Codes: A61L 31/088 Other specific inorganic materials not covered by A61L31/084 or A61L31/086
• CPC Class Codes: A61L 31/14 Materials characterised by their function or physical properties , e.g. injectable or lubricating compositions, shape-memory materials, surface modified materials
• CPC Class Codes: A61M 2005/3104 Caps for syringes without needle
• CPC Class Codes: A61M 2005/3131 specially adapted for improving sealing or sliding
• CPC Class Codes: A61M 5/28 Syringe ampoules or carpules, i.e. ampoules or carpules provided with a needle
• CPC Class Codes: A61M 5/3129 Syringe barrels A61M5/3205 and A61M5/50 take precedence
• CPC Class Codes: A61M 5/3134 characterised by constructional features of the distal end, i.e. end closest to the tip of the needle cannula
• CPC Class Codes: A61M 5/3202 Devices for protection of the needle before use, e.g. caps A61M5/50 takes precedence; for infusion spikes A61M5/1626; protectors for sharps A61B50/3001
• CPC Class Codes: C23C 16/32 Carbides
• CPC Class Codes: C23C 16/401 containing silicon
• CPC Class Codes: C23C 16/45523 Pulsed gas flow or change of composition over time
• CPC Class Codes: C23C 16/50 using electric discharges generation and control of plasma in discharge tubes for surface treatment H01J37/32, H01J37/34
• CPC Class Codes: C23C 16/505 using radio frequency discharges
• CPC Class Codes: C23C 16/511 using microwave discharges
• CPC Class Codes: C23C 16/515 using pulsed discharges

Abstract

A method for coating a substrate surface such as a syringe part by PECVD is provided, the method comprising generating a plasma from a gaseous reactant comprising an organosilicon precursor and optionally an oxidizing gas by providing plasma-forming energy adjacent to the substrate, thus forming a coating on the substrate surface by plasma enhanced chemical vapor deposition (PECVD). The plasma-forming energy is applied in a first phase as a first pulse at a first energy level followed by further treatment in a second phase at a second energy level lower than the first energy level. The lubricity, hydrophobicity and/or barrier properties of the coating are set by setting the ratio of the O₂ to the organosilicon precursor in the gaseous reactant, and/or by setting the electric power used for generating the plasma.

Claims

1. A method for preparing a lubricity coating on a plastic substrate, the method comprising:

(a) providing a gas comprising an organosilicon precursor, optionally an oxidizing gas, and an inert gas in the vicinity of the substrate surface;

(b) generating plasma in the gas by applying plasma-forming energy adjacent to the plastic substrate as a first pulse at a first energy level; and

(c) after said step (b), generating plasma in the gas by applying plasma-forming energy adjacent to the plastic substrate as a second pulse at a second energy level lower than the first energy level;

thus forming a coating on the substrate surface by plasma enhanced chemical vapor deposition (PECVD).

2. The method of claim 1, in which the first pulse energy level is from 21 to 100 Watts.

3. The method of claim 1, in which the first pulse is applied for 0.1 to 5 seconds.

4. The method of claim 1, in which the second pulse energy level is from 1 to 10 Watts.

5. The method of claim 1, in which the container size is from 1 to 10 mL.

6. The method of claim 1, in which the lubricity coated container is further treated by post heating it at 50 to 110 degrees C. for a time interval of 1 to 72 hours.

7. The method of claim 6, in which the post heating step is carried out under at least partial vacuum.

8. The method of claim 1, wherein the organosilicon precursor comprises a linear or monocyclic siloxane.

9. The method according to claim 1, wherein the oxidizing gas comprises O₂ present in a volume-volume ratio to the organosilicon precursor of from 0.01:

1 to 0.5;

1.

10. The method according to claim 1, wherein Ar is present as the inert gas.

11. The method according to claim 1, wherein the gas comprises from 1 to 6 standard volumes of the organosilicon precursor, from 1 to 100 standard volumes of the inert gas, and from 0.1 to 2 standard volumes of O₂.

12. The method according to claim 1, wherein both Ar and O₂ are present.

13. The method according to claim 1, wherein the resulting coating has a roughness when determined by AFM and expressed as RMS of from 7 to 20 nm.

14. The method according to claim 1, additionally comprising a step for preparing a barrier coating on the substrate before the lubricity coating is applied, the additional step comprising:

(a) providing a gas comprising an organosilicon precursor and an oxidizing gas in the vicinity of the substrate surface; and

(b) generating plasma from the gas, thus forming an SiO_x barrier coating on the substrate surface by plasma enhanced chemical vapor deposition (PECVD).

15. The method according to claim 14 wherein in the step for preparing a barrier coating

(i) the plasma is generated with electrodes powered with sufficient power to form an SiO_x barrier coating on the substrate surface;

and

(ii) the ratio of the electrode power to the plasma volume is equal or more than 5 W/ml; and

/or

(iii) the oxidizing gas comprises O₂ in a volume;

volume ratio of from 1;

1 to 100;

1 in relation to the silicon containing precursor.

16. The method according to claim 1, wherein the substrate is a polymer selected from the group consisting of a polycarbonate, an olefin polymer, a cyclic olefin copolymer (COC), a cyclic olefin polymer (COP), and a polyester.

17. The method according to claim 1, wherein the plasma is generated with RF energy.

18. The method according to claim 1, wherein the plasma-forming energy reduces the breakout force, F_i, of the syringe, compared to the breakout force of a similar syringe that has only been treated at the second energy level.

19. The method according to claim 1, wherein the resulting lubricity coating has an atomic ratio Si_wO_xC_y or Si_wN_xC_y wherein w is 1, x is from about 0.5 to about 2.4, y is from about 0.6 to about 3.

20. A coated substrate coated with a lubricity coating made by the method according to claim 1.

21. The coated substrate of claim 20, wherein the lubricity coating has a lower frictional resistance than the uncoated surface by at least 25%.

22. A syringe comprising a barrel made according to claim 1.

23. The syringe according to claim 22 which contains in its lumen a medicament.

24. The syringe of claim 22, wherein the plunger initiation force F_i is from 2.5 to 15 N and the plunger maintenance force F_m is from 2.5 to 25 N after 1 week.

25. The method of claim 1 wherein the lubricity coating has the atomic ratio Si_wO_xC_y wherein w is 1, x is from about 0.5 to about 2.4, y is from about 0.6 to about 3.

26. The method of claim 1, wherein the plastic substrate is COP, wherein the gas in step (a) comprises octamethylcyclotetrasiloxane, O₂ and Ar, and wherein the power for generating the plasma is from 6 W/ml to 0.1 W/ml in relation to the volume of the syringe lumen.

28. The method of claim 1, in which the first pulse is applied for 0.1 to 5 seconds and the first pulse energy level is from 21 to 100 Watts.

27. A method for preparing a lubricity coating on a plastic substrate, the method comprising:

(a) providing plasma enhanced chemical vapor deposition (PECVD) equipment;

(b) in the plasma enhanced chemical vapor deposition (PECVD) equipment, providing a gas comprising an organosilicon precursor, optionally an oxidizing gas, and an inert gas in the vicinity of the substrate surface;

(c) in the plasma enhanced chemical vapor deposition (PECVD) equipment, generating plasma in the gas by providing plasma-forming energy adjacent to the plastic substrate as a first pulse at a first energy level; and

(d) after step (c), in the same plasma enhanced chemical vapor deposition (PECVD) equipment, without breaking vacuum, generating plasma in the gas by providing plasma-forming energy adjacent to the plastic substrate as a second pulse at a second energy level lower than the first energy level;

thus forming a coating on the substrate surface by plasma enhanced chemical vapor deposition (PECVD).