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US 6,548,628 B2Granted
Process for producing a film or layer
AssigneeBasell Polyolefine GmbH
InventorsAndreas Winter, Ernst Hofmann, Gerhard Wieners, Bernd Bachmann
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AssigneeBasell Polyolefine GmbH
InventorsAndreas Winter, Ernst Hofmann, Gerhard Wieners, Bernd Bachmann
Estimating the term…
The present invention relates to single- or multilayer films and one or more layers comprising at least one polyolefin molding composition containing at least one polyolefin derived from at least one olefin having at least 2 carbon atoms, of the formula Ra—CH═CH—Rb, in which Ra and Rb are identical or different and are a hydrogen atom or a straight-chain or branched C1-C15-alkyl radical, or Ra and Rb, together with the atoms connecting them, form a ring or ring system, and the polyolefin has been prepared by means of metallocene catalysts. The present invention furthermore relates to a process for the production of films and layers in which a polyolefin molding composition having a particle size of from 20 μm to 5000 μm is used or prepared. The shaped polyolefin molding composition is melt-mixed with at least one additive and shaped. The melt-mixed and shaped material is melted at a temperature of from 150° C. to 300° C. The molten material is cooled and at the same time shaped to give a film or layer. Finally, the present invention also relates to the use of films and layers for the production of articles such as bags, composite materials and laminates.
A process for producing a film or a layer comprising the steps of:
Dependencies are inferred from the claim text.
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From the US filing history. Foreign family members aren’t listed.
Comprising polyolefins : comprising polyolefins obtained by a metallocene or single-site catalyst
Producing flat articles, e.g. films or sheets: films or sheets
Layered products comprising a layer of synthetic resin: as the main or only constituent of a layer, which is next to another layer of the same or…
Layered products comprising a layer of synthetic resin: comprising polyolefins
Term ended 20 Dec 2016 (estimated)
USPTO file history isn’t available for this patent, so only indexed dates are shown.
The present invention relates to films and layers of relatively high rigidity and strength, improved transparency and high gloss. The present invention furthermore relates to an economical and environmentally friendly process for the production of films and layers.
EP-A 484 816 and EP-A 484 817 disclose heat-sealable packaging films. The films described consist of a polypropylene base layer and at least one top layer of a propylene polymer, where the base layer is built up from an isotactic polypropylene and the top layer is built up from a copolymer of an α-olefin having 2 to 8 carbon atoms and syndiotactic propylene.
EP-A 589 213 discloses a heat-sealable multilayer polypropylene film, a process for the production thereof, and the use thereof. The multilayer film includes at least one base layer predominantly comprising polypropylene, and at least one top layer. The top layer is sealable and comprises an isotactic homopolymer of an olefin.
The sole FIGURE (FIG. 1) of the Drawing is a flow chart illustrating a novel process carried out according to this invention in which films and layers are produced from propylene homopolymer or propylene copolymer and articles are produced from these materials.
The polyolefin molding composition has an MFR (230/2.16) of from 0.3 to 260 g/10 min, or an MFR (230/5) of from 1 to 750 g/10 min. The MFR (230/2.16) is preferably from 1 to 150 g/10 min, particularly preferably 1.5 to 50 g/10 min. The MFR (230/5) is preferably from 3 to 450 g/10 min, particularly preferably from 4.5 to 150 g/min.
The molar mass is from 100,000 to 500,000 g/mol, preferably from 110,000 to 400,000 g/mol, particularly preferably from 120,000 to 340,000 g/mol. The polydispersity Mw/Mn is from 1.5 to 10, preferably from 2 to 5, particularly preferably <3. The viscosity number is from 100 to 450 cm3/g, preferably from 110 to 350 cm3/g, particularly preferably from 120 to 300 cm3/g.
The melting point is from 120 to 165° C., preferably from 130 to 162° C., particularly preferably from 140 to 160° C. The content of atactic polyolefin (ether-extractable content) is <2% by weight, preferably <1% by weight, particularly preferably <0.5% by weight, very particularly preferably <0.3% by weight. The residual catalyst content with respect to chlorine is <70 ppm, preferably <30 ppm, particularly preferably <20 ppm and with respect to transition metals is <50 ppm, preferably <20 ppm, particularly preferably <10 ppm.