The present invention deals with a process for producing a coated pipe. The process comprises (i) homopolymerising ethylene or copolymerising ethylene and an -olefin comonomer in a first polymerisation step in the presence of a polymerisation catalyst to produce a first ethylene homo- or copolymer having a density of from 940 to 980 kg/m.sup.3 and a melt flow rate MFR.sub.2 of from 1 to 2000 g/10 min; (ii) homopolymerising ethylene or copolymerising ethylene and an -olefin comonomer in a second polymerisation step in the presence of a first ethylene homo- or copolymer to produce a first ethylene polymer mixture comprising the first ethylene homo- or copolymer and a second ethylene homo- or copolymer, said first ethylene polymer mixture having a density of from 940 to 980 kg/m.sup.3 and a melt flow rate MFR.sub.2 of from 10 to 2000 g/10 min; (iii) copolymerising ethylene and an -olefin comonomer in a third polymerisation step in the presence of the first ethylene polymer mixture to produce a second ethylene polymer mixture comprising the first ethylene polymer mixture and a third ethylene copolymer, said second ethylene polymer mixture having a density of from 915 to 965 kg/m.sup.3, preferably from 930 to 955 kg/m.sup.3 and a melt flow rate MFR.sub.5 of from 0.2 to 10 g/10 min; (iv) providing a pipe having an outer surface layer; (v) applying a coating composition onto the pipe outer surface layer to form a top coat layer, wherein the coating composition comprises the second ethylene polymer mixture.

The present invention deals with a process for producing a coated pipe. The process comprises (i) homopolymerising ethylene or copolymerising ethylene and an -olefin comonomer in a first polymerisation step in the presence of a polymerisation catalyst to produce a first ethylene homo- or copolymer having a density of from 940 to 980 kg/m.sup.3 and a melt flow rate MFR.sub.2 of from 1 to 2000 g/10 min; (ii) homopolymerising ethylene or copolymerising ethylene and an -olefin comonomer in a second polymerisation step in the presence of a first ethylene homo- or copolymer to produce a first ethylene polymer mixture comprising the first ethylene homo- or copolymer and a second ethylene homo- or copolymer, said first ethylene polymer mixture having a density of from 940 to 980 kg/m.sup.3 and a melt flow rate MFR.sub.2 of from 10 to 2000 g/10 min; (iii) copolymerising ethylene and an -olefin comonomer in a third polymerisation step in the presence of the first ethylene polymer mixture to produce a second ethylene polymer mixture comprising the first ethylene polymer mixture and a third ethylene copolymer, said second ethylene polymer mixture having a density of from 915 to 965 kg/m.sup.3, preferably from 930 to 955 kg/m.sup.3 and a melt flow rate MFR.sub.5 of from 0.2 to 10 g/10 min; (iv) providing a pipe having an outer surface layer; (v) applying a coating composition onto the pipe outer surface layer to form a top coat layer, wherein the coating composition comprises the second ethylene polymer mixture.

New ethylene polymers having low levels of long chain branching are disclosed. Films and film layers made form these polymers have good hot tack strength over a wide range of temperatures, making them good materials for packaging applications.

New ethylene polymers having low levels of long chain branching are disclosed. Films and film layers made form these polymers have good hot tack strength over a wide range of temperatures, making them good materials for packaging applications.

Disclosed herein is a cast film comprising a polyethylene composition comprising the reaction product of ethylene and optionally one or more alpha-olefin comonomers, wherein said polyethylene composition is characterized by the following properties: a melt index, I2, measured according to ASTM D1238 (2.16 kg, 190 C.), of from 1 to 20 g/10 min; a density (measured according to ASTM D792) of from 0.935 to 0.970 g/cm3; a melt flow ratio, I.sub.10/I.sub.2, wherein I.sub.10 is measured according to ASTM D1238 (10 kg, 190 C.) of from 5.5 to 7.0; a molecular weight distribution (Mw/Mn) of from 2.2 to 3.5; and a vinyl unsaturation of greater than 0.12 vinyls per one thousand carbon atoms present in the backbone of the composition.

Disclosed herein is a cast film comprising a polyethylene composition comprising the reaction product of ethylene and optionally one or more alpha-olefin comonomers, wherein said polyethylene composition is characterized by the following properties: a melt index, I2, measured according to ASTM D1238 (2.16 kg, 190 C.), of from 1 to 20 g/10 min; a density (measured according to ASTM D792) of from 0.935 to 0.970 g/cm3; a melt flow ratio, I.sub.10/I.sub.2, wherein I.sub.10 is measured according to ASTM D1238 (10 kg, 190 C.) of from 5.5 to 7.0; a molecular weight distribution (Mw/Mn) of from 2.2 to 3.5; and a vinyl unsaturation of greater than 0.12 vinyls per one thousand carbon atoms present in the backbone of the composition.

A crack-resistant article comprising a diene terpolymer, the diene terpolymer comprising (or consisting essentially of) from 0.01 wt % to 10.0 wt % diene derived units, and 1.0 wt % to 20 wt % of C.sub.4 to C.sub.10 -olefin derived units based on the weight of the diene terpolymer, wherein the diene terpolymer: a) has a g.sub.vis of less than 0.90; b) has an Mw within a range of from 100,000 g/mol to 500,000 g/mol; c) has an Mw/Mn within the range of from 3.5 to 12.0; and d) an Mz/Mn of greater than 7.0. Inventive articles comprise a blend of a relatively high density linear polyethylene and the diene terpolymer.

A crack-resistant article comprising a diene terpolymer, the diene terpolymer comprising (or consisting essentially of) from 0.01 wt % to 10.0 wt % diene derived units, and 1.0 wt % to 20 wt % of C.sub.4 to C.sub.10 -olefin derived units based on the weight of the diene terpolymer, wherein the diene terpolymer: a) has a g.sub.vis of less than 0.90; b) has an Mw within a range of from 100,000 g/mol to 500,000 g/mol; c) has an Mw/Mn within the range of from 3.5 to 12.0; and d) an Mz/Mn of greater than 7.0. Inventive articles comprise a blend of a relatively high density linear polyethylene and the diene terpolymer.

A polyethylene composition for producing blow-molded hollow articles, having the following features: 1) density from 0.940 to 0.955 g/cm.sup.3, determined according to ISO 1183 at 23 C.; 2) ratio MIF/MIP from 12 to 40; 3) Mz from 500,000 to 3,500,000 g/mol; 4) .sub.0.02 from 80,000 to 300,000 Pa.Math.s; 5) HMWcopo index from 1 to 15; and 6) Mz/Mw*LCBI lower than 6.4.

A foamable or foamed article comprising a diene terpolymer, the diene terpolymer comprising (or consisting essentially of) from 0.01 wt % to 10.0 wt % diene derived units, and 1.0 wt % to 20 wt % of C.sub.4 to C.sub.10 -olefin derived units based on the weight of the diene terpolymer, wherein the diene terpolymer: a) has a g.sub.vis of less than 0.90; b) has an Mw within a range of from 100,000 g/mol to 500,000 g/mol; c) has an Mw/Mn within the range of from 3.5 to 12.0; and d) an Mz/Mn of greater than 7.0. Inventive articles comprise a blend of a relatively high density linear polyethylene and the diene terpolymer.