| 摘要 |
PURPOSE: To provide a method for melt-mixing a high molecular weight ethylene polymer and a low molecular weight ethylene polymer by a two-stage method. CONSTITUTION: In the first stage, a high molecular weight ethylene polymer at least about 50,000 poise in viscosity and a low molecular weight ethylene polymer below about 3000 poise in viscosity are melt-mixed to form the first polymer blend. Next, in the second stage, the additional low molecular weight ethylene polymer is melt-mixed with the first polymer blend to form the second polymer blend. The melt-mixing is carried out at the highest melting point of the polymers and at a temperature higher by about 200 deg.C than the highest melting point. In order to improve compatibility, an intermediate molecular weight polymer is also used as the third component, and the a film produced from the final polymer blend has a low gel content (fish eye) and is applicable to another thermoplastic resin. |
