High molecular weight polyethylene composition, product and process of making same

Abstract

This disclosure relates to a novel type of high molecular weight polyethylene composition, and product made from said composition, with industrially useful properties, and the process of making said composition and product.

1 . A composition comprising:
 i) a first virgin polyethylene resin, having a bimodal molecular weight distribution which is high molecular weight (HMW), having a high load melt index measured according ASTM D-1238 (HLMI) of from about 1 to 6 g/10 min; and comprising a particle size distribution of less than about 50 μm and a weight average molecular weight of about 100,000 to 500,000;   ii) a second virgin polyethylene resin, an HLMI from about 20-70 g/10 min, a melt flow index measured according ASTM D-1238 (MFI) of from about 0.20-0.60 g/10 min, and comprising a particle size distribution of less than about 50 μm, and a weight average molecular weight of about 60,000 to 100,000;   iii) a first post-consumer polyethylene resin, having a MFI of from about 0.10-0.70 g/10 min, and a weight average molecular weight of about 40,000 to 120,000;   iv) a second post-consumer polyethylene resin, which is HMW, and having a HLMI of from about 4-8 g/10 min, and a weight average molecular weight of about 80,000 to 500,000; and   v) a polyethylene antioxidant.   
     
     
         2 . The composition of  claim 1 , further comprising one or more additives. 
     
     
         3 . The composition of  claim 2 , wherein said one or more additives is comprising a dye, a heat stabilizer, a UV absorber, a plasticizer, an opacifier, a nucleating agent, a clarifier, a diluent, or a fillers, or a combination thereof. 
     
     
         4 . The composition of  claim 1 , wherein said first virgin polyethylene resin, has a density of from about 0.948 to 0.955 g/cm 3 , said second virgin polyethylene resin, has a density of from about 0.950 to 0.960 g/cm 3 , said first post-consumer polyethylene resin has a density of from about 0.955 to 0.970 g/cm 3 , and said second post-consumer polyethylene resin has a density of from about 0.952 to 0.958 g/cm 3 . 
     
     
         5 . The composition of  claim 1 , wherein a weight ratio of the total of said first and second virgin polyethylene resin: the total of said first and second post-consumer polyethylene resin in the composition is from about 0.8-1.2:1.2-0.8. 
     
     
         6 . The composition of  claim 1 , wherein a weight ratio of the first virgin polyethylene resin to the second virgin polyethylene resin is from about 0.8-1.2 and a weight ratio of the first post-consumer polyethylene resin to the second post-consumer polyethylene resin is from about 0.8-1.2:1.2-0.8. 
     
     
         7 . A polyethylene product comprising a composition comprising:
 i) a first virgin polyethylene resin, having a bimodal molecular weight distribution which is high molecular weight (HMW), having a high load melt index measured according ASTM D-1238 (HLMI) of from about 1 to 6 g/10 min; and comprising a particle size distribution of less than about 50 μm, and a weight average molecular weight of about 100,000 to 500,000;   ii) a second virgin polyethylene resin, an HLMI from about 20-70 g/10 min, a melt flow index measured according ASTM D-1238 (MFI) of from about 0.20-0.60 g/10 min, and comprising a particle size distribution of less than about 50 μm, and a weight average molecular weight of about 60,000 to 100,000;   iii) a first post-consumer polyethylene resin, having a MFI of from about 0.10-0.70 g/10 min, and a weight average molecular weight of about 40,000 to 120,000;   iv) a second post-consumer polyethylene resin, which is HMW, and having a HLMI of from about 4-8 g/10 min, and a weight average molecular weight of about 80,000 to 500,000; and   v) a polyethylene antioxidant.   
     
     
         8 . The product of  claim 7 , further comprising one or more additives. 
     
     
         9 . The product of  claim 7 , wherein said one or more additives is comprising a dye, a heat stabilizer, a UV absorber, a plasticizer, an opacifier, a nucleating agent, a clarifier, a diluent, or a fillers, or a combination thereof. 
     
     
         10 . The product of  claim 7 , wherein said product is an extruded film, sheet, or pellet, or an injection molded product. 
     
     
         11 . The product of  claim 7 , wherein said product has at least one property selected from a density of about 0.94-0.96 g/cm 3 , a MFI of about 0.05-0.15 g/10 min, a HLMI of about 9-11 gr/10 min, a notched Izod impact factor of >8 ft-lb/in assessed according to ASTM D256, a Flexural Modulus at 2% strain of about 950-1200 Mpa assessed according to ASTM D790 and Tensile Yield of greater than about 25 Mpa assessed according to ASTM D638. 
     
     
         12 . The product of  claim 7 , wherein said first virgin polyethylene resin, has a density of from about 0.948 to 0.955 g/cm 3 , said second virgin polyethylene resin, has a density of from about 0.950 to 0.960 g/cm 3 , said first post-consumer polyethylene resin has a density of from about 0.955 to 0.970 g/cm 3 , and said second post-consumer polyethylene resin has a density of from about 0.952 to 0.958 g/cm 3 . 
     
     
         13 . The product of  claim 7 , wherein a weight ratio of the total of said first and second virgin polyethylene resin: the total of said first and second post-consumer polyethylene resin in the composition is from about 0.8-1.2:1.2-0.8. 
     
     
         14 . The product of  claim 7 , wherein a weight ratio of the first virgin polyethylene resin to the second virgin polyethylene resin is from about 0.8-1.2 and a weight ratio of the first post-consumer polyethylene resin to the second post-consumer polyethylene resin is from about 0.8-1.2:1.2-0.8. 
     
     
         15 . A process for preparing an polyethylene product, said process comprising the steps of:
 (a) providing:   i) a first virgin polyethylene resin, having a bimodal molecular weight distribution which is high molecular weight (HMW), having a high load melt index measured according ASTM D-1238 (HLMI) of from about 1 to 6 g/10 min; and comprising a particle size distribution of less than about 50 μm, and a weight average molecular weight of about 100,000 to 500,000;   ii) a second virgin polyethylene resin, an HLMI of from about 20-70 g/10 min, a melt flow index measured according ASTM D-1238 (MFI) of from about 0.20-0.60 g/10 min, and comprising a particle size distribution of less than about 50 μm, and a weight average molecular weight of about 60,000 to 100,000;   iii) a first post-consumer polyethylene resin, having a MFI of from about 0.10-0.70 g/10 min, and a weight average molecular weight of about 40,000 to 120,000;   iv) a second post-consumer polyethylene resin, which is HMW, and having a HLMI of from about 4-8 g/10 min, and a weight average molecular weight of about 80,000 to 500,000; and   v) a polyethylene antioxidant;   (b) blending i) to v) from step (a); and   (c) melting and shaping the blend from step (b) to obtain said polyethylene product.   
     
     
         16 . The process of  claim 15 , comprising mixing the antioxidant with the first, second or both of the virgin polyethylene resin. 
     
     
         17 . The process of  claim 15 , wherein said shaping the blend from step (b) is comprising extruding or injection molding of said blend. 
     
     
         18 . The process of  claim 15 , wherein said first virgin polyethylene resin, has a density of from about 0.948 to 0.955 g/cm 3 , said second virgin polyethylene resin, has a density of from about 0.950 to 0.960 g/cm 3 , said first post-consumer polyethylene resin has a density of from about 0.955 to 0.970 g/cm 3 , said second post-consumer polyethylene resin has a density of from about 0.952 to 0.958 g/cm 3 . 
     
     
         19 . The process of  claim 15 , wherein a weight ratio of the total of said first and second virgin polyethylene resin: the total of said first and second post-consumer polyethylene resin in the composition is from about 0.8-1.2:1.2-0.8. 
     
     
         20 . The process of  claim 15 , wherein a weight ratio of the first virgin polyethylene resin to the second virgin polyethylene resin is from about 0.8-1.2 and a weight ratio of the first post-consumer polyethylene resin to the second post-consumer polyethylene resin is from about 0.8-1.2:1.2-0.8.