| 摘要 |
PURPOSE:To avoid the increase of viscosity or the coagulation of magnetic powder owing to the progress of hardening reaction caused by a stay, by mixing a magnetic coating material and a hardener by a prescribed amount at a mixing part to send them to a coating part and at the same time sending the mixture partially back to the mixing part before coating to stir it consecutively. CONSTITUTION:A magnetic coating material containing the magnetic powder, a binder, a dispersant, etc. is sent to a tank 13 from a disperser 11. A hardener (precursor) is put into a tank 15 and stirred consecutively. Both the coating material and the hardener are sent consecutively to a static mixer 24 of a mixing part by a prescribed amount from tanks 13 and 15 by pumps 17 and 18 via flow-meters 19 and 20 respectively. The mixture is supplied from the mixing part to a coating part 29 via a quantitative pump 26, a disperser 27 and a filter 28. Then flow rate/viscosity measuring devices 31 and 32 are provided at the outlet part of the mixer 24 and the part 29 respectively. A circulating pipe 35 is set between the inlet and outlet parts of the mixer 24 to always send a part of the mixture 24. Thus a flowing state is kept. In such a way, the fixed physical properties can be maintained with the mixture. Thus it is possible to obtain a magnetic recording medium which has always fixed characteristics. |
