Propylene polymer resins

Abstract

Propylene-based polymer resins and related compositions and processes are disclosed. The propylene polymer resins have high isotacticity and moderately high xylene soluble content. The polymer resins provide extruded sheets suitable for thermo-forming that exhibit both sag resistance and ease of draw.

1 . A propylene polymer resin comprising:
 a. a xylene soluble content greater than 2; and   b. a mesopentad content in the xylene-insoluble fraction greater than 93.5.   
     
     
         2 . The propylene polymer resin of  claim 1 , having a melt flow rate greater than 0.4 g/10 min. 
     
     
         3 . The propylene polymer resin of  claim 1  or  claim 2 , having a M w /M n  greater than 5.5 and a M z /M n  greater than 20. 
     
     
         4 . The propylene polymer resin of  claim 1 , having a critical frequency for onset of shear-thinning, 1/K, less than 1.2 s −1 , where K is a Cross model constant, and a melt strength greater than 15 cN at 190° C. 
     
     
         5 . The propylene polymer resin of  claim 1 , wherein the propylene polymer resin comprises a propylene homopolymer. 
     
     
         6 . The propylene polymer resin of  claim 1 , wherein the propylene polymer resin comprises a copolymer of propylene and ethylene or other alpha-olefin. 
     
     
         7 . An article manufactured from a propylene polymer resin comprising:
 a. a xylene soluble content greater than 2%; and   b. a mesopentad content in the xylene-insoluble fraction greater than 93.5%.   
     
     
         8 . The article of  claim 7 , wherein the propylene polymer resin has a melt flow rate greater than 0.4 g/10 min. 
     
     
         9 . The article of  claim 7  or  claim 8 , wherein the propylene polymer resin has a M w /M n  greater than 5.5 and a M z /M n  greater than 20. 
     
     
         10 . The article of  claim 7 , wherein the propylene polymer resin has a critical frequency for onset of shear-thinning, 1/K, less than 1.2 s −1 , where K is a Cross model constant, and a melt strength greater than 15 cN at 190° C. 
     
     
         11 . An extruded sheet s comprising a propylene polymer resin having:
 a. a melt flow rate greater than 0.4 grams per 10 minutes;   b. a M w /M n  greater than 5.5, and a M z /M n  greater than 20;   c. a critical frequency for onset of shear-thinning, 1/K, less than 1.2 s −1 , where K is a Cross model constant;   d. a melt strength greater than 15 cN at 190° C.;   e. a xylene soluble content greater than 2%;   f. a mesopentad content in the xylene-insoluble fraction greater than 93.5%; and   g. a temperature suitable for forming of at least 290° C.   
     
     
         12 . The extruded sheet of  claim 11 , having width at least 55 cm and thickness between 0.04 and 0.85 inches, which upon heating to the temperature suitable for forming exhibits sag per unit area of less than 0.43 inches −1  when supported only at the edges of the sheet. 
     
     
         13 . The extruded sheet of  claim 11 , having width at least 55 mm and thickness between 0.04 and 0.5 inches, which upon heating to the temperature suitable for forming, sags less than 0.43 inches per unit area when supported only at the edges of the sheet, wherein when the sheet is forced into a mold cavity it requires less than or equal to 3900 psi forming force per inch of sheet thickness. 
     
     
         14 . The extruded sheet of  claim 11 , having width at least 55 mm and thickness between 0.51 and 0.7 inches, which upon heating to the temperature suitable for forming sags less than 0.43 inches per unit area when supported only at the edges of the sheet, wherein when the sheet is forced into a mold cavity it requires less than or equal to 5100 psi forming force per inch of sheet thickness, wherein the force is applied to the upper sheet surface. 
     
     
         15 . The extruded sheet of  claim 11 , having width at least 55 mm and thickness greater than 0.71 inches, which upon heating to the temperature suitable for forming sags less than 0.43 inches per unit area when supported only at the edges of the sheet wherein when the sheet is forced into a mold cavity it requires less than or equal to 4400 psi forming force per inch of sheet thickness, wherein the force is applied to the upper sheet surface. 
     
     
         16 . A thermoformed article formed from the extruded sheet of  claim 11 . 
     
     
         17 . A film comprising the propylene polymer of  claim 1 .