| 主权项 |
1. A method for accelerating an injection moulding process of a polymer composition, the method comprising a step of mixing an additive into a polymer P0 to form the polymer composition, the additive is used in amount of 1 to 20% by weight of the polymer composition, the polymer P0 is selected from the group consisting of a homopolymer of polyethylene (PE), a homopolymer of polypropylene (PP), and a PP-PE copolymer consisting of PP and PE monomers, the method further comprising performing a shaping to form a molded body by injection moulding in which the polymer composition is used, wherein the additive is a premix based on a polymer mixture, the polymer mixture comprising:
at least one first polymer P1 having a weight average molecular weight Mw>20,000 g/mol, wherein the first polymer P1 comprises at least one block of at least 10 monomer units M1 each individually selected from the group consisting of ethylene and propylene, the first polymer P1 is selected from the group consisting of a homopolymer of PE, a homopolymer of PP, and a PE-PP copolymer consisting of PP and PE monomers, the MFI of the at least one first polymer P1 is 1-50 g per 10 min at 190° C. and at 2.16 kg, and at least one second polymer P2 having a viscosity of <200 mPas measured at a temperature of 10° C. above the melting point of the first polymer P1 and which comprises at least one block of at least 10 monomer units M1, the monomers M1 constituting the second polymer P2 are the same as the monomers M1 constituting the first polymer P1, the second polymer P2 selected from the group consisting of PE wax and PP wax, the difference in the crystallization temperatures of the polymer P1 and the polymer P2 is less than 15° C., these crystallization temperatures being measured as onset temperatures by DSC at a cooling rate of 20° C./min, wherein the ratio of the polymer P2 based on the polymer P1 and P2, in % by weight, is in the range >B and <F, wherein the value of B is 49 for an MFI of 1 g/10 min of the polymer P1, is 45 for an MFI of 10 g/10 min of the polymer P1, is 44 for an MFI of 20 g/10 min of the polymer P1, and is 43 for an MFI of 50 g/10 min of the polymer P1, and wherein the value B for an MFI of the polymer P1 not given is obtained from the above values by linear interpolation or extrapolation, wherein the value of F is 78 for an MFI of 1 g/10 min of the polymer P1, is 75 for an MFI of 10 g/10 min of the polymer P1, is 74 for an MFI of 20 g/10 min of the polymer P1, and is 73 for an MFI of 50 g/10 min of the polymer P1, and wherein the value F for an MFI of the polymer P1 not given is obtained from the above values by linear interpolation or extrapolation, the additive has a proportion of particulate components which are insoluble in the polymer mixture of 0% by weight or <20% by weight based on the polymers P1 and P2, the additive has an MFI of 8 to 200 g per 10 min and the melting point of the additive is less than or equal to 7° C. higher than the melting point of the polymer P1, and the polymer in the polymer composition consist of (i) the polymer P0, (ii) the at least one first polymer P1, and (iii) the at least one second polymer P2. |
