Visbreaking process

Abstract

A process for increasing MFR2 of a polyethylene copolymer or an ethylene plastomer or elastomer comprising: (I) extruding a copolymer of polyethylene copolymer having a density of 910 to 970 kg/m3 and an MFR2 of 1 and 100 g/10 min or an ethylene plastomer or elastomer having a density of 855 to 910 kg/m3 and an MFR2 of 0.5 and 100 g/10 min in the presence of 0.1 to 2 wt % of a non-peroxide radical initiator so as to produce a polyethylene copolymer having an MFR2 of 200 g/10 min or more, or an ethylene plastomer or elastomer having a MFR2 of 200 g/10 min or more.

1 . (canceled) 
     
     
         2 . The method of  claim 12 , wherein the radical initiator decomposes at a temperature greater than 200° C. 
     
     
         3 . The method of  claim 12 , wherein the extruding is performed by an extruder operated with a screw speed of from 300 to 1400 rpm. 
     
     
         4 . The method of  claim 12 , wherein the produced polyethylene copolymer or ethylene plastomer or elastomer has an MFR2 which is 200 g/10 min or more higher than the MFR 2  before extrusion. 
     
     
         5 . The method of  claim 12 , wherein the MFR2 of the polyethylene copolymer or ethylene plastomer or elastomer after extrusion is at least 500 g/10 min. 
     
     
         6 . The method of  claim 12 , wherein the MFR2 of the polyethylene copolymer or ethylene plastomer or elastomer before extrusion is from 1 to 10 g/10 min. 
     
     
         7 . The method of  claim 12 , wherein the extruding is performed by an extruder comprising a barrel, wherein heat is applied to the barrel at a maximum temperature of at least 300° C. 
     
     
         8 . The method of  claim 3 , wherein the screw speed in the extruder is from 300 to 1200 rpm. 
     
     
         9 . The method of  claim 3 , wherein the extruder provides a specific energy input SEI of 0.15 kWh/kg or more. 
     
     
         10 . The method of  claim 12 , wherein all of the radical initiator is added at the start of the extrusion 
     
     
         11 . (canceled) 
     
     
         12 . A method of use of a product of a the process as a hot melt adhesive or in spunbond or melt blown applications, wherein the product comprises a polyethylene copolymer or ethylene plastomer or elastomer made by a process for increasing the MFR 2  of a polyethylene copolymer or an ethylene plastomer or elastomer, the process comprising:
 extruding a copolymer of polyethylene having a density of from 910 to 970 kg/m 3  and an MFR2 of from 1 to 100 g/10 min in the presence of from 0.1 to 2 wt % of a radical initiator so as to produce a polyethylene copolymer having an MFR2 of 200 g/10 min or more, or   extruding an ethylene plastomer or elastomer having a density of from 855 to 910 kg/m 3  and an MFR2 of from 0.5 to 100 g/10 min in the presence of 0.1 to 2 wt % of a an ethylene plastomer or elastomer having an MFR2 of 200 g/10 min or more,   wherein the radical initiator comprises a non-peroxide radical initiator, a radical initiator which decomposes at a temperature greater than 200° C., or a combination thereof.   
     
     
         13 . (canceled) 
     
     
         14 . A visbroken composition comprising:
 a visbroken polyethylene copolymer having a density of from 910 to 940 kg/m 3  and an MFR2 of 200 g/l0 min or more or   a visbroken ethylene plastomer or elastomer having a density of from 855 to 910 kg/m 3  and an MFR2 of 200 g/l0 min or more;   said polyethylene copolymer or ethylene plastomer or elastomer having:   a crosslinking degree measured as XHU of less than 0.50 wt %; and   an Mw/Mn of from 1.5 to 4;   and a compound of formula R1R2R3CH and/or R4RSR6CH,   wherein each of Ri, R3, R4 and R6 independently is selected from the group consisting of hydrogen, substituted and unsubstituted straight, branched, and cyclic, hydrocarbons with 1 to 12 C-atoms and substituted and unsubstituted aromatic hydrocarbons with 6 to 12 C atoms, and   wherein each of R2 and Rs independently is selected from the group consisting of substituted and unsubstituted straight, branched, and cyclic hydrocarbons with 1 to 12 C-atoms and substituted and unsubstituted aromatic hydrocarbons with 6 to 12 C-atoms and   wherein at least one of R 1 , R 2 , R 3 , R 4 , R 5  and R 6  is a substituted or unsubstituted aromatic hydrocarbon with 6 to 12 C-atoms.   
     
     
         15 . The visbroken polyethylene copolymer composition of  claim 14 , wherein the visbroken polyethylene copolymer or ethylene plastomer or elastomer has a viscosity eta0.05 (measured according to ISO 6721-1 and 10 at 0.05 rad/s and at 190° C.) of from 10 Pa·s to 40 Pa·s. 
     
     
         16 . A hot melt adhesive comprising
 A) 10 to 100 wt % of the visbroken composition of  claim 14 ;   (B) one or more tackifiers in an amount of 0 to 70 wt %; and   (C) one or more plasticizers in an amount of 0 to 60 wt %, one or more waxes in an amount of 0 to 10 wt %, or a combination thereof.