| 摘要 |
FIELD: chemistry. ^ SUBSTANCE: invention relates to a polyethylene moulding composition for pressure casting finished parts, for example bottle tops and bottles, and to a method of preparing said moulding composition. The composition has polymodal molecular weight distribution and contains an ethylene homopolymer (A) with low molecular weight, an ethylene copolymer (B) with high molecular weight an ethylene copolymer (C) with ultrahigh molecular weight. At temperature 23C, the moulding composition has density of 0.948-0.957 g/cm3, melt flow rate MFR (190C/2.16 kg) of 1-2.7 dg/min and coefficient of viscosity VN3 of the mixture of ethylene homopolymer A, copolymer B and ethylene copolymer C, measured in accordance with ISO/R 1191 in decalin at temperature 135C ranging from 150 to 240 cm3/g. ^ EFFECT: besides processability, the moulding composition has high mechanical strength and rigidity, excellent organoleptic properties and high cracking resistance under the effect of the surrounding medium. ^ 12 cl, 2 tbl, 2 ex |
