Modifiers based on ethylenes or amorphous olefin elastomers for reducing the surface tack of amorphous polypropylenes
AssigneeBorealis AG
InventorsMarkus Gahleitner, Hermann Heinemann, Norbert Hafner, Christian Paulik
Life of this patent
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Abstract
Modifiers based on high-pressure polyethylenes or low-pressure ethylene copolymers or highly amorphous olefin elastomers or mixtures of these with polyethylenes or isotactic polypropylenes are added to highly amorphous polypropylenes to reduce their surface tack.
Claims8
A method for reducing surface tack which comprises using a modifier selected from the following classes of materials:
- a) high-pressure uncatalyzed ethylene homopolymers or ethylene-higher-x-olefin copolymers with a proportion of more than 90 mol % of ethylene and with a density of not more than 0.92 g/cm3 (LDPE),
- b) low-pressure catalyzed ethylene-higher-α-olefin copolymers with a proportion of more than 75 mol % of ethylene and with a density of not more than 0.93 g/cm3 (LLDPE), and
- c) highly amorphous olefin elastomers with an enthalpy of fusion of not more than 15 J/g, composed of copolymers of ethylene and propylene (EPR) or of terpolymers of ethylene, propylene and dienes (EPDM) having a density of not more than 0.88 9/cm3, or else mixtures of these olefin elastomers with polyethylenes or with isotactic polypropylenes, where the proportion of the olefin elastomer by weight is in each case more than 50%,
- as a component for adding to a highly amorphous polypropylene (base polymer) with an enthalpy of fusion of not more than 40 J/g and a melt flow index of from 0.1 to 50 g/10 min, where the highly amorphous polypropylene is a homopolymer of propylene or a copolymer of propylene with one or more α-olefins and has a proportion of at least 80 mol % of propylene.
A process for reducing the surface tack of highly amorphous polypropylene (base polymer) with an enthalpy of fusion of not more than 40 J/g and a melt flow index of from 0.1 to 50 g/10 min, where the highly amorphous polypropylene is a propylene homopolymer or a copolymer of propylene with one or more α-olefins and has a proportion of not less than 80 mol % of propylene, which comprises admixing modifiers selected from the following classes of materials:
- a) high-pressure uncatalyzed ethylene homopolymers or ethylene-higher-a-olefin copolymers with a proportion of more than 90 mol % of ethylene and with a density of not more than 0.92 g/cm3 (LDPE),
- b) low-pressure catalyzed ethylene-higher-u-olefin copolymers with a proportion of more than 75 mol % of ethylene and with a density of not more than 0.93 g/cm3 (LLDPE), and
- c) highly amorphous olefin elastomers with an enthalpy of fusion of not more than 15 J/g, composed of copolymers of ethylene and propylene (EPR) or of terpolymers of ethylene, propylene and dienes (EPDM) having a density of not more than 0.88 g/cm3, or else mixtures of these olefin elastomers with polyethylenes or with isotactic polypropylenes, where the proportion of the olefin elastomer by weight is in each case more than 50%
- into the highly amorphous polypropylenes.
Dependencies are inferred from the claim text.