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.

New C.sub.2C.sub.3 random copolymer (RACO), which shows improved sealing behaviour due to low sealing initiation temperature (SIT) and high hot tack force. In addition, the inventive C.sub.2C.sub.3 random copolymer (RACO) shows an excellent sterilization behaviour, i.e. retention of low haze level after sterilization. The present invention is furthermore related to the manufacture of said C.sub.2C.sub.3 random copolymer (RACO) and to its use.

A polyethylene composition having a high flow index and a bimodal composition provides an outstanding combination of environmental stress crack resistance (ESCR) and ductility in rotomolded articles. The composition is easy to process/mold.

The invention provides a multimodal propylene butene random copolymer having a melt flow rate (MFR2) of 1.0 to 20.0 g/10 min and a butene content of 1.5 to 8.0 wt %, wherein said copolymer is prepared using a single site catalyst and wherein said copolymer comprises (i) 30 to 70 wt % of a propylene butene copolymer (A) having an MFR2 of 0.5 to 20.0 g/10 min and a butene content of 0.5 to 10.0 wt %; and (ii) 70 to 30 wt % of a propylene butene copolymer (B) having an MFR2 of 0.5 to 20.0 g/10 min and a butene content of 1.0 to 8.0 wt %; wherein copolymers (A) and (B) are different.

The invention provides a multimodal propylene butene random copolymer having a melt flow rate (MFR.sub.2) of 1.0 to 20.0 g/10 min and a butene content of 5.0 to 20.0 wt %, wherein said copolymer is prepared using a single site catalyst and wherein said copolymer comprises: (i) 30 to 70 wt % of a propylene butene copolymer (A) having an MFR.sub.2 of 0.5 to 20.0 g/10 min and a butene content of 2.0 to 10.0 wt %; and (ii) 70 to 30 wt % of a propylene butene copolymer (B) having an MFR.sub.2 of 0.5 to 20.0 g/10 min and a butene content of 4.0 to 20.0 wt %; wherein copolymers (A) and (B) are different.

The invention relates to a polypropylene composition comprising: (A) a first polypropylene which is a metallocene-catalyzed homopolymer, or a metallocene-catalyzed random copolymer of propylene and of a co-monomer having at most 0.5% by weight of co-monomer content, relative to the total weight of the random copolymer, as determined by .sup.13C NMR analysis; and (B) a second polypropylene which is a metallocene-catalyzed random copolymer of propylene and of a co-monomer;
wherein said polypropylene composition is as defined in claim 1.

The present invention also relates to a process for the preparation of said polypropylene composition. The present invention also relates to an article comprising said polypropylene composition.

A polyethylene composition includes a first polyethylene which is an ethylene copolymer having a weight average molecular weight of from 70,000 to 250,000 and a molecular weight distribution Mw/Mn of <2.3, a second polyethylene which is an ethylene copolymer or homopolymer having a weight average molecular weight of from 15,000 to 100,000 and a molecular weight distribution Mw/Mn of <2.3, and a third polyethylene which is an ethylene copolymer or homopolymer having a weight average molecular weight of from 70,000 to 250,000 and a molecular weight distribution Mw/Mn of >2.3, where the first polyethylene has more short chain branching than the second polyethylene or the third polyethylene. The polyethylene composition has a soluble fraction in a CEF analysis of at least 10 weight percent. Film made from the polyethylene composition may have a machine direction 1% secant modulus of □190 MPa (at a film thickness of about 1 mil), a seal initiation temperature (SIT) of ≤100° C. (at a film thickness of about 2 mil), an area of hot tack window (AHTW) of ≥160 Newtons.Math.C° (at a film thickness of about 2 mil) and an oxygen transmission rate (OTR) of ≥650 cm3 per 100 inch2 per day (at a film thickness of about 1 mil).

The present disclosure provides formulation. The formulation contains a high density polyethylene composition containing (i) a high molecular weight component including an ethylene/a-olefin copolymer, the high molecular weight component having a density from 0.924 to 0.930 g/cc and a high load melt index (121) from 0.3 to 0.9 g/10 min; and (ii) a low molecular weight component including an ethylene-based polymer selected from the group consisting of an ethylene homopolymer and an ethylene/a-olefin copolymer. The high density polyethylene composition has (a) a density from 0.950 to 0.956 g/cc; (b) a high load melt index (121) from 15 to 28 g/10 min; (c) an 121/12 of at least 85; (d) a notched constant tensile load failure time at 35% yield stress of greater than 90 hours; and (e) an environmental stress crack resistance (ESCR) F0 value, according to ASTM D1693—condition B (100% IGEPAL), of greater than 2,000 hours.

A polyethylene composition includes a first polyethylene which is an ethylene copolymer having a weight average molecular weight of from 70,000 to 250,000 and a molecular weight distribution M.sub.w/M.sub.n of <2.3, a second polyethylene which is an ethylene copolymer or homopolymer having a weight average molecular weight of from 15,000 to 100,000, a molecular weight distribution M.sub.w/M.sub.n of >2.3, and a third polyethylene which is an ethylene copolymer or homopolymer having a weight average molecular weight of from 70,000 to 250,000 and a molecular weight distribution M.sub.w/M.sub.n of >2.3, where the first polyethylene has more short chain branching than the second polyethylene or the third polyethylene. The polyethylene composition has a soluble fraction in a CEF analysis of at least 10 weight percent. Film made from the polyethylene composition may have a machine direction 1% secant modulus of 200 ≥MPa (at a film thickness of about 1 mil), a seal initiation temperature (SIT) of ≤90° C. (at a film thickness of about 2 mil), an area of hot tack window (AHTW) of ≥160 Newtons.Math.C° (at a film thickness of about 2 mil) and an oxygen transmission rate (OTR) of ≥600 cm.sup.3 per 100 inch per day (at a film thickness of about 1 mil).

The invention relates to a process for producing a polypropylene composition by sequential polymerization the polypropylene composition having an improved balanced combination of high flowability, high stiffness and impact, and high level of optical properties.