Polypropylene thin film and preparation method thereof

[0017]The preparation method of the polypropylene film provided by the present invention comprises mixing polypropylene and self-lubricating microparticles uniformly, feeding them into an extruder for melting and kneading, extruding and granulating to obtain a raw material for a smooth surface layer; The raw material and polypropylene are sent to extrusion casting equipment with a multi-layer co-extrusion structure for extrusion casting to obtain a smooth surface layer comprising a polypropylene core layer and at least one side surface attached to the polypropylene core layer Polypropylene film; the smooth surface layer is a polypropylene layer dispersed with self-lubricating particles; the polypropylene in the polypropylene core layer and the smooth surface layer has a melt index greater than 5g / 10min at 230°C and 2.16kg and less than or equal to 20g / 10min; the self-lubricating particles are polymer particles with a melting temperature greater than or equal to 250°C and a coe

[0026] This example is used to illustrate the preparation of the polypropylene film provided by the present invention.

[0027] In this embodiment, the polypropylene forming the polypropylene core layer and the smooth surface layer is purchased from Sinopec Shanghai Petrochemical Co., Ltd., with a melt index of 6 g / 10 minutes at 230 ° C and a temperature of 2.16 kg, and a melting temperature of 156 ° C .

[0028] (1) Preparation of smooth surface layer raw materials:

[0029] The polypropylene is dried in a hot air oven, wherein the drying method is continuous blowing with dry hot air at 80° C. for 8 hours. Add 99.5 parts by weight of dried polypropylene and 0.5 parts by weight of polytetrafluoroethylene particles (particle diameter is 2-4 microns) into the mixer and stir evenly at 25 ° C. The mixer first mixes at a low speed of 100 rpm About 7 minutes, then mix at 200 rpm for 8 minutes at high speed;

[0030] Send the above-mentioned uniformly stirred mixture into a twin-sc

[0034] This example is used to illustrate the preparation of the polypropylene film provided by the present invention.

[0035] In this embodiment, the polypropylene core layer and the smooth surface layer are purchased from Singapore TPC Company, with a melt index of 20 g / 10 minutes and a melting temperature of 146° C. at 230° C. and 2.16 kg.

[0036] (1) Preparation of smooth surface layer raw materials:

[0037] The polypropylene is dried in a hot air oven, wherein the drying method is continuous blowing with dry hot air at 80° C. for 8 hours. Add 97 parts by weight of dried polypropylene and 3 parts by weight of polytetrafluoroethylene particles (with a particle diameter of 5-10 microns) into a mixer and stir evenly at 25°C. The mixer first mixes at a low speed of 120 rpm About 5 minutes, then mix at 180 rpm for 6 minutes at high speed;

[0038] Send the above-mentioned uniformly stirred mixture into a twin-screw extruder, adjust the screw speed to 150 rpm, and control th