Process and product of high strength uhmw pe fibers

Abstract

An improved process for solution spinning of ultra-high molecular weight polyethylene (UHMW PE) filaments, wherein the 10 wt % solution of the UHMW PE in mineral oil at 250° C. has a Cogswell extensional viscosity and a shear viscosity within select ranges.

1 - 20 . (canceled) 
     
     
         21 . A solid ultra-high molecular weight polyethylene (UHMW PE) filament produced by a process comprising the steps of:
 a) selecting an UHMW PE having an intrinsic viscosity (IV) from about 5 dl/g to about 45 dl/g when measured in decalin at 135° C., wherein a 10 wt. % solution of the UHMW PE in mineral oil at 250° C. has a Cogswell extensional viscosity (λ) in accordance with the following formula:
   λ≧5,917(IV) 0.8 ;
 
   b) dissolving the UHMW PE in a solvent at elevated temperature to form a solution having a concentration of from about 5 wt. % to about 50 wt. % of UHMW PE;   c) discharging the solution through a spinneret to form solution filaments;   d) cooling the solution filaments to form gel filaments;   e) removing solvent from the gel filaments to form solid filaments containing less than about 5 wt. % of solvent;   f) stretching at least one of the solution filaments, the gel filaments and the solid filaments to a combined stretch ratio of at least 10:1, wherein the solid filaments are stretched to a ratio of at least 2:1. stretch ratio of at least 10:1, wherein at least 2:1 is of the solid filaments.   
     
     
         22 . The solid ultra-high molecular weight polyethylene filament of  claim 21 , wherein the 10 wt. % solution of the UHMW PE in mineral oil at a temperature of 250° C. has an Cogswell extensional viscosity at least 65,000 Pa-s. 
     
     
         23 . The solid ultra-high molecular weight polyethylene filament of  claim 21 , wherein the 10 wt. % solution of the UHMW PE in mineral oil at a temperature of 250° C. has a Cogswell extensional viscosity (λ) in accordance with the following formula:
   λ≧7,282(IV) 0.8 .
 
 
     
     
         24 . The solid ultra-high molecular weight polyethylene filament of  claim 21 , wherein the 10 wt. % solution of the UHMW PE in mineral oil at a temperature of 250° C. has a Cogswell extensional viscosity (λ) in accordance with the following formula:
   λ≧10,924(IV) 0.8 .
 
 
     
     
         25 . The solid ultra-high molecular weight polyethylene filament of  claim 21  wherein the 10 wt. % solution of the UHMW PE in mineral oil at a temperature of 250° C. has a shear viscosity, and the Cogswell extensional viscosity is at least five times the shear viscosity. 
     
     
         26 . The solid ultra-high molecular weight polyethylene filament of  claim 21  wherein a 10 wt. % solution of the UHMW PE in mineral oil at a temperature of 250° C. has an Cogswell extensional viscosity and a shear viscosity such that the Cogswell extensional viscosity is at least eight times the shear viscosity. 
     
     
         27 . The solid ultra-high molecular weight polyethylene filament of  claim 21  wherein a 10 wt. % solution of the UHMW PE in mineral oil at a temperature of 250° C. has an Cogswell extensional viscosity and a shear viscosity such that the Cogswell extensional viscosity is at least eleven times the shear viscosity. 
     
     
         28 . A multi-filament yarn comprising a plurality of the filaments of  claim 21 . 
     
     
         29 . The multi-filament yarn of  claim 28  having a tenacity of at least 40 g/d (36 cN/dtex). 
     
     
         30 . The multi-filament yarn of  claim 28 , wherein the yarn is utilized in an application selected from the group consisting of ballistic articles, composite materials, fishing lines, sails, ropes, sutures and fabrics. 
     
     
         31 . A solid ultra-high molecular weight polyethylene (UHMW PE) filament produced by a process comprising the steps of:
 a) selecting an UHMW PE having an intrinsic viscosity from 5 to 45 dl/g when measured in decalin at 135° C., wherein a 10 wt. % solution of the UHMW PE in mineral oil at 250° C. has a Cogswell extensional viscosity and a shear viscosity such that the Cogswell extensional viscosity is at least eight times the shear viscosity;   b) dissolving the UHMW PE in a solvent to form a solution having a concentration of from about 5 wt. % to about 50 wt. % of UHMW PE;   c) discharging the solution through a spinneret to form solution filaments;   d) cooling the solution filaments to form gel filaments;   e) removing solvent from the gel filaments to form solid filaments containing less than about 5 wt. % of solvent;   f) stretching at least one of the solution filaments, the gel filaments and the solid filaments to a combined stretch ratio of at least 10:1, wherein the solid filaments are stretched to a ratio of at least 2:1.   
     
     
         32 . The solid ultra-high molecular weight polyethylene filament of  claim 31 , wherein the 10 wt % solution of the UHMW PE in mineral oil at 250° C. has a Cogswell extensional viscosity and a shear viscosity such that the Cogswell extensional viscosity is at least eleven times the shear viscosity. 
     
     
         33 . The solid ultra-high molecular weight polyethylene filament of  claim 31 , wherein the 10 wt. % solution of the UHMW PE in mineral oil at 250° C. has a Cogswell extensional viscosity (λ) in accordance with the following formula:
   λ≧5,917(IV) 0.8 .
 
 
     
     
         34 . The solid ultra-high molecular weight polyethylene filament of  claim 31 , wherein the 10 wt. % solution of the UHMW PE in mineral oil at a temperature of 250° C. has an Cogswell extensional viscosity at least 65,000 Pa-s. 
     
     
         35 . The solid ultra-high molecular weight polyethylene filament of  claim 31 , wherein the 10 wt. % solution of the UHMW PE in mineral oil at a temperature of 250° C. has a Cogswell extensional viscosity (λ) in accordance with the following formula:
   λ≧7,282(IV) 0.8 .
 
 
     
     
         36 . The solid ultra-high molecular weight polyethylene filament of  claim 31 , wherein the 10 wt. % solution of the UHMW PE in mineral oil at a temperature of 250° C. has a Cogswell extensional viscosity (λ) in accordance with the following formula:
 λ≧10,924(IV) 0.8 . 
 
     
     
         37 . A multi-filament yarn comprising a plurality of the filaments of  claim 31 . 
     
     
         38 . The multi-filament yarn of  claim 37  having a tenacity of at least 40 g/d (36 cN/dtex). 
     
     
         39 . The multi-filament yarn of  claim 37 , wherein the yarn is utilized in an application selected from the group consisting of ballistic articles, composite materials, fishing lines, sails, ropes, sutures and fabrics.