Spheroidal polyester polymer particles

Abstract

Spheroidal polyester polymer particles, as well as preforms and stretch blow molded bottles made from the spheroidal particles, are provided which have: A) an It.V. of at least 0.72 dL/g, and either B) at least two melting peaks (on a DSC first heating scan), wherein one of said at least two melting peaks is a low peak melting point having a peak temperature within a range of 140° C. to 220° C. and having a melting endotherm area of at least the absolute value of 1 J/g, or C) a low degree of crystallinity within a range of at least 20% and a maximum degree of crystallinity T cmax defined by the equation: T cmax =50%−CA−OH where CA is the total mole % of all carboxylic acid residues other than terephthalic acid residues, based on 100 mole % of carboxylic acid residues in the polyester polymer, and OH is the total mole % of hydroxyl functional compound residues other than ethylene glycol residues, based on 100 mole % of the hydroxyl functional compounds residues; or both B) and C); and optionally but preferably D) 10 ppm or less of residual acetaldehyde.

1 . A bulk comprising polyester polymer spheroids having: 
 A) an average It.V. of at least 0.72 dL/g, and either ‘B) melting points characterized by: 
 a. at least two melting peaks, wherein one of said at least two melting peaks when measured on a first DSC scan is a low peak melting point having a peak temperature within a range of 140° C. to 220° C. and having a melting endotherm area of at least the absolute value of 1 J/g, or  
 b. having one or more melting points which, when measured on a DSC first heating scan, has a heating curve departing from a baseline in the endothermic direction at a temperature of less than or equal to 200° C., or  
   C) a low degree of crystallinity within a range of at least 20% and a maximum degree of crystallinity T cmax  defined by the equation:        T   cmax =50%−CA−OH    where CA is the total mole % of all carboxylic acid residues other than terephthalic acid residues, based on 100 mole % of carboxylic acid residues in the polyester polymer, and OH is the total mole % of hydroxyl functional compound residues other than ethylene glycol residues, based on 100 mole % of the hydroxyl functional compounds residues; or both B) and C).    
   
   
       2 . The bulk of  claim 1 , wherein the bulk comprises at least 75% virgin polyester polymer.  
   
   
       3 . The bulk of  claim 2 , wherein the bulk has a residual acetaldehyde level of 10 ppm or less.  
   
   
       4 . The bulk of  claim 1 , wherein the spheroids have an angle of repose of less than 34.0° measured by a gate test with an actual pellet temperature of 165° C. after 5 hours.  
   
   
       5 . The bulk of  claim 4 , wherein the angle of repose is less than 32°.  
   
   
       6 . The bulk of  claim 5 , wherein the angle of repose is less 31° or less.  
   
   
       7 . The bulk of  claim 1 , wherein the spheroids have a roundness distribution, and the mode of the distribution is less than 1.4.  
   
   
       8 . The bulk of  claim 5 , wherein the mode of the roundness distribution is 1.2 or less.  
   
   
       9 . The bulk of  claim 1 , wherein the spheroids are characterized by both B) and C).  
   
   
       10 . The bulk of  claim 1 , wherein the polyester polymer spheroids comprise: 
 (a) a carboxylic acid component comprising at least 80 mole % of the residues of terephthalic acid or derivatives of terephthalic acid, or mixtures thereof, and    (b) a hydroxyl component comprising at least 80 mole % of the residues of ethylene glycol,    based on 100 mole percent of carboxylic acid component residues and 100 mole percent of hydroxyl component residues in the polyester polymer.    
   
   
       11 . The bulk of  claim 10 , wherein the polyester polymer spheroids comprise: 
 (a) a carboxylic acid component comprising at least 90 mole % of the residues of terephthalic acid and/or derivatives of terephthalic acid, and    (b) a hydroxyl component comprising at least 90 mole % of the residues of ethylene glycol,    based on 100 mole percent of the carboxylic acid component residues and 100 mole percent of the hydroxyl component residues in the polyester polymer.    
   
   
       12 . The bulk of  claim 1 , wherein the spheroids have a low peak melting point within a range of 160° C. to 210° C., a degree of crystallinity ranging from 25% to 45%, the number average weight of the spheroids is at least 1.0 grams per 100 particles and does not exceed 100 grams per 100 particles, and the residual acetaldehyde content is 7 ppm or less.  
   
   
       13 . The bulk of  claim 12 , wherein the spheroids have an It.V. ranging from 0.75 dL/g up to about 1.1 dL/g, and contain 2 ppm or less of residual acetaldehyde.  
   
   
       14 . The bulk of  claim 1 , wherein the spheroids have a low peak melting point shoulder.  
   
   
       15 . The bulk of  claim 1 , wherein the It.V. of the spheroids ranges from 0.78 dL/g to 1.1 dL/g.  
   
   
       16 . The bulk of  claim 1 , wherein the It.V. of the spheroids ranges from 0.81 dL/g to 1.2 dL/g.  
   
   
       17 . The bulk of  claim 1 , wherein the spheroids are contained in a shipping container, and the spheroids are not solid state polymerized.  
   
   
       18 . The bulk of  claim 1 , wherein the spheroids are obtained by underwater cutting the polyester polymer.  
   
   
       19 . The bulk of  claim 1 , wherein the spheroids have a degree of crystallinity obtained by thermal crystallization of the spheroids in a liquid medium comprising water at a temperature above the T g  of the polyester polymer.  
   
   
       20 . A method for drying and melt processing polyester polymer spheroids comprising: 
 A) drying polyester polymer spheroids in a drying zone to produce dried spheroids;    B) introducing the dried spheroids into a melting processing zone;    C) melting the polyester polymer spheroids in the melt processing zone, and    D) forming an article from the molten polymer;    wherein the polyester polymer spheroids introduced into the drying zone are not solid state polymerized.    
   
   
       21 . The method of  claim 20 , wherein the residual acetaldehyde level of the spheroids introduced into the drying zone is 10 ppm or less.  
   
   
       22 . The method of  claim 20 , wherein the spheroids have degree of crystallinity ranging from 25% to 45%.  
   
   
       23 . The method of  claim 20 , wherein the spheroids have one or more melting point characterized by: 
 a. at least two melting peaks, wherein one of said at least two melting peaks when measured on a DSC first heating scan is a low peak melting point having a peak temperature within a range of 140° C. to 220 ° C. and having a melting endotherm area of at least the absolute value of 1 J/g, or    b. having one or more melting points which, when measured on a DSC first heating scan, has a heating curve departing from a baseline in the endothermic direction at a temperature of less than or equal to 200° C.    
   
   
       24 . The method of  claim 20 , wherein the spheroids introduced into the drying zone have: 
 A) an average It.V. of at least 0.72 dL/g, and either    B) melting points characterized by: 
 (i) at least two melting peaks, wherein one of said at least two melting peaks when measured on a DSC first heating scan is a low peak melting point having a peak temperature within a range of 140° C. to 220° C. and having a melting endotherm area of at least the absolute value of 1 J/g, or  
 (ii) having one or more melting points which, when measured on a DSC first heating scan, has a heating curve departing from a baseline in the endothermic direction at a temperature of less than or equal to 200° C.,  
   or    C) a low degree of crystallinity within a range of at least 20% and a maximum degree of crystallinity T cmax  defined by the equation:        T   cmax =50%−CA−OH    where CA is the total mole % of all carboxylic acid residues other than terephthalic acid residues, based on 100 mole % of carboxylic acid residues in the polyester polymer, and OH is the total mole % of hydroxyl functional compound residues other than ethylene glycol residues, based on 100 mole % of the hydroxyl functional compounds residues; and    D) a residual acetaldehyde level of 10 ppm or less.    
   
   
       25 . The method of  claim 20 , wherein the spheroids introduced into the drying zone comprise at least 75% virgin polyester polymer.  
   
   
       26 . The method of  claim 20 , wherein the spheroids introduced into the drying zone comprise have an angle of repose of less than 34.0° measured by a gate test with an actual pellet temperature of 165° C. after 5 hours.  
   
   
       27 . The method of  claim 26 , wherein the angle of repose is less than 32°.  
   
   
       28 . The method of  claim 20 , wherein the spheroids introduced into the drying zone have a roundness distribution, and the mode of the distribution is less than 1.4.  
   
   
       29 . The method of  claim 20 , wherein the mode is 1.2 or less.  
   
   
       30 . The method of  claim 20 , wherein the spheroids introduced into the drying zone comprise: 
 (a) a carboxylic acid component comprising at least 80 mole % of the residues of terephthalic acid or derivatives of terephthalic acid, or mixtures thereof, and    (b) a hydroxyl component comprising at least 80 mole % of the residues of ethylene glycol,    based on 100 mole percent of carboxylic acid component residues and 100 mole percent of hydroxyl component residues in the polyester polymer.    
   
   
       31 . The method of  claim 20 , wherein the spheroids introduced into the drying zone comprise: 
 (a) a carboxylic acid component comprising at least 90 mole % of the residues of terephthalic acid and/or derivatives of terephthalic acid, and    (b) a hydroxyl component comprising at least 90 mole % of the residues of ethylene glycol,    based on 100 mole percent of the carboxylic acid component residues and 100 mole percent of the hydroxyl component residues in the polyester polymer.    
   
   
       32 . The method of  claim 20 , wherein the spheroids introduced into the drying zone have a low peak melting point within a range of 160° C. to 210° C., a degree of crystallinity ranging from 25% to 45%, the number average weight of the spheroids is at least 1.0 grams per 100 particles and does not exceed 100 grams per 100 particles, and the residual acetaldehyde content is 7 ppm or less.  
   
   
       33 . The method of  claim 20 , wherein the spheroids introduced into the drying zone have an It.V. within the range of 0.78 dL/g to 1.1 dL/g.  
   
   
       34 . The method of  claim 20 , wherein the spheroids introduced into the drying zone are obtained by underwater cutting the polyester polymer.  
   
   
       35 . The method of  claim 20 , wherein the spheroids have a degree of crystallinity obtained by thermal crystallization of the spheroids in a liquid medium comprising water at a temperature above the T g  of the polyester polymer.  
   
   
       36 . A preform obtained by the method of  claim 20 .  
   
   
       37 . A stretch blow molded bottle obtained by the method of  claim 20 .  
   
   
       38 . A perform obtained by the method of  claim 24 .  
   
   
       39 . A stretch blow molded bottle obtained by the method of  claim 24 .  
   
   
       40 . A perform obtained from the bulk of  claim 1 .  
   
   
       41 . A stretch blow molded bottle obtained from the bulk of  claim 1 .  
   
   
       42 . The method of  claim 20 , wherein the article is a sheet.  
   
   
       43 . The method of  claim 24 , wherein the article is a sheet.  
   
   
       44 . A sheet obtained from the bulk of  claim 1.