Patent DE-102010011192-A1 (DE)
Title: Surface-treatment of substrate made of glass/glass ceramic by atmospheric pressure plasma, comprises performing treatment of partial areas of substrate surface in plasma treatment zone and treating fixed point of substrate during treatment
Inventor: BICKER MATTHIAS DR
IPC: C03C23/00
Filed: 2010-03-11
Abstract: The surface-treatment method comprises carrying out a treatment of partial areas of a surface of the substrate in a treatment zone of a plasma, and treating a fixed point of the substrate during the treatment using an increased energy density (epsilon 1) for a period (t 1) in first step, using an increased energy density (epsilon 2) for a period (t 2) in second step and using a decreased energy density (epsilon 3) for a period (t 3) in third step, where the energy density (epsilon 2) lies above a threshold value of (epsilon s). The method for the surface-treatment of the substrates made of glass or glass ceramic using an atmospheric pressure plasma, comprises carrying out a treatment of partial areas of a surface of the substrate in a treatment zone of a plasma, and treating a fixed point of the substrate during the treatment using an increased energy density (epsilon 1) for a period (t 1) in a first step, using an increased energy density (epsilon 2) for a period (t 2) in a second step and using a decreased energy density (epsilon 3) for a period (t 3) in a third step, where the energy density (epsilon 2) lies above a threshold value of (epsilon s) that is equal to epsilon /2, where epsilon /2 is an energy density averaged over a reaction zone. A flat and partially curved hollow body is used as substrate. The substrate and the treatment zone of the plasma are moved relative to each other during the surface treatment, where the substrate or the treatment zone or both are moved. The substrate and the treatment zone of the plasma are led in a rotational motion and/or a translational motion. A speed of the relative movement is 0.05-4 m/s. The atmospheric pressure plasma is a dielectric hindered barrier discharge in the form of a filamented or homogeneous barrier discharge or a remote-plasma with a separate reactive plasma zone. The substrate to be treated forms a part of the dielectric barrier with the use of dielectric hindered barrier discharge. A process gas is used, in which the collision frequency is 10-200 GHz and which has a species-atom of exciting atoms, ions or molecules having an inner radius of less than 3 Å . The tubes with an external diameter of 2-70 mm are surface-treated as substrate, where the partial areas of the inner side of the tubes are treated. The treatment zone of the plasma is cuboid, has a height of H 1, a width of B 1and a length of L 1, is cylindrically symmetric, and has an inner diameter of (D i 2), an outer diameter of (D a 2) and a length of L 2, where H 1is 0.1-30 mm, B 1is 1-1000 mm, L 1is 1-1000 mm, the difference between D i 2and D a 2is delta 2that is 0.1-30 mm and L 2is less than alpha A m a x, where alpha is 0.05 and A m a xcomprises the maximum substrate dimension from the dimensions of height, width and length. The plasma is regulated by an electrode arrangement comprising cathode and anode, where the electrode arrangement is adapted to the substrate geometry, so that plane-parallel or slightly curved 2D-electrodes are used in flat substrates, a cylindrical or cylindrical-like electrode arrangement is used in tubular or cylindrically-symmetrical substrates with an inner electrode in the tube and an outer electrode around the tube and rectangular electrodes are used in angular hollow body. The electrode distance to the flat substrate is selected with curved or plane geometry of less than 2mm. A gap dimension (S a) between the outer electrode and the outer side of the substrate is used in cylindrically-symmetrical substrates with S aless than D a/10, where D ais the outer diameter of the tube. The plasma zone is guided in relation to the substrate surface, where the guidance takes place by the movement of a plasma source or the electrodes and the guidance runs vertical to the axis of the substrate movement. Two plasma sources are used for the surface treatment. The substrate is heated by treating at a temperature below a glass transition temperature of maximum 20[deg] C. The surface treatment is carried out as inline-process and directly takes place at tube puller as continuous process. A coating is applied in connection to the surface treatment using plasma process and using homogeneous dielectric hindered barrier discharge or filamented barrier discharge. An independent claim is included for a glass- or glass ceramic product.