| (19) |
 |
|
(11) |
EP 0 824 970 A3 |
| (12) |
EUROPEAN PATENT APPLICATION |
| (88) |
Date of publication A3: |
|
07.08.2002 Bulletin 2002/32 |
| (43) |
Date of publication A2: |
|
25.02.1998 Bulletin 1998/09 |
| (22) |
Date of filing: 19.08.1997 |
|
|
| (84) |
Designated Contracting States: |
|
AT BE CH DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE |
| (30) |
Priority: |
19.08.1996 GB 9617368
|
| (71) |
Applicant: AIR PRODUCTS AND CHEMICALS, INC. |
|
Allentown, PA 18195-1501 (US) |
|
| (72) |
Inventors: |
|
- Paterson, Alan John Francis
Crewe, Cheshire CW3 0LB (GB)
- Irven, John
High Wycombe, Buckinghamshire HP15 6JS (GB)
- Obadun, Segun Lateef
Birmingham, West Midlands B21 8BU (GB)
|
| (74) |
Representative: Burford, Anthony Frederick |
|
W.H. Beck, Greener & Co. 7 Stone Buildings Lincoln's Inn
London WC2A 3SZ
London WC2A 3SZ (GB) |
|
| |
|
| (54) |
Coated gas cylinders |
(57) A gas cylinder is coated on its internal, gas-contacting surface with a polar film-forming
polymer, such as poly(vinyl alcohol), whereby non-polar organic molecules will not
adhere to the polymer film. The coating greatly increases the stability of gases stored
in the cylinder, which is particularly useful in storing gas mixtures used for gas
calibration methods.