PROCESS FOR PREPARING A CAP OR CLOSURE

    公开(公告)号:US20220227030A1

    公开(公告)日:2022-07-21

    申请号:US17607059

    申请日:2020-04-28

    Applicant: BOREALIS AG

    Abstract: A process for producing a cap or closure comprising obtaining a polypropylene composition by sequential polymerization comprising the steps: A) polymerizing in a first reactor, preferably a slurry reactor, in the presence of a Ziegler-Natta catalyst monomers comprising propylene and optionally one or more comonomers selected from ethylene and C4-C10 alpha-olefins, to obtain a first propylene polymer fraction having a comonomer content in the range of 0.0 to 1.8 wt %, and a MFR2 in the range of from 12.0 to 40.0 g/10 min, as measured according to ISO 1133 at 230° C. under a load of 2.16 kg; B) polymerizing in a second reactor, preferably a first gas-phase reactor, monomers comprising propylene and one or more comonomers selected from ethylene and C4-C10 alpha-olefins, in the presence of the first propylene polymer fraction, to obtain a second propylene polymer fraction, wherein the polypropylene composition comprising said first and second propylene polymer fractions has an MFR2 in the range of from 12.0 to 60.0 g/10 min, as measured according to ISO 1133 at 230° C. under a load of 2.16 kg, has a comonomer content in the range of from 2.2 to 5.0 wt % and wherein the ratio of the comonomer content of component A) to the comonomer content of the polypropylene composition is 0.35 or less, C) melting, extruding and moulding the polypropylene composition in the presence of at least one nucleating agent to prepare a cap or closure; and D) exposing the cap or closure obtained in step (C) to a cooling rate of 50 K/s or more.

    HIGH SPEED CROSS-LINKING OF GRAFTED PLASTOMERS

    公开(公告)号:US20220315716A1

    公开(公告)日:2022-10-06

    申请号:US17276275

    申请日:2019-09-26

    Applicant: BOREALIS AG

    Abstract: The present invention discloses a process for providing a cross-linked composition, the process comprising the steps of (a) providing an ethylene-α-olefin plastomer having—a density of from 850 kg/m3 to 900 kg/m3; and—an melt flow rate (ISO 1133, 2.16 kg, 190° C.) of 0.3 to 50 g/10 min; (b) grafting the ethylene-α-olefin plastomer with silane crosslinker such that the content of silane crosslinker is in the range of 0.1 to 10.0 wt.-% with respect to the grafted ethylene-α-olefin plastomer; (c) contacting said grafted ethylene-α-olefin plastomer with 2 to 8 wt.-% of a tin-free silane crosslinking catalyst with respect to the resulting mixture of grafted ethylene-α-olefin plastomer and tin-freesilane crosslinking catalyst, wherein said tin-free catalyst comprises a Brönsted acid at 23° C. and 50% relative humidity for at least 15 minutes thus forming a cross-linked composition, wherein gel content of said cross-linked composition after 15 min is at least 60%.

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