PET Polymer with Improved Properties

Abstract

Polyester compositions having desirable injection molding properties and that retain good crystallization rates and natural stretch ratio characteristics are described. These polyesters are suitable for the manufacture of beverage containers, bulk continuous filaments, and other articles that can benefit from such improved properties.

1 . A polyester comprising:
 i) a carboxylic acid component comprising at least 90 mol % terephthalic acid residues and from 0 to 10 mol % of carboxylic acid comonomer residues;   ii) a hydroxyl component comprising from 90 to 95 mol % ethylene glycol residues and additional hydroxyl residues in an amount from 5 to 10 mol %; wherein the additional hydroxyl residues are chosen from a) diethylene glycol residues and b) mixtures of diethylene glycol residues and hydroxyl comonomer residues;   based on 100 mol % of carboxylic acid component residues and 100 mol % of hydroxyl component residues in the polyester;   wherein at least one of the carboxylic acid and hydroxyl components comprises comonomer residues, the molar ratio of the total comonomer residues to diethylene glycol residues being 1.3:1.0 or greater; and   wherein the polyester comprises less than 2.3 mol % of diethylene glycol and has an intrinsic viscosity greater than 0.40 dL/g and less than 0.80 dL/g   
     
     
         2 . A polyester according to  claim 1 ,
 wherein the carboxylic acid comonomer is chosen from phthalic acid, isophthalic acid, (C 1 -C 4 ) dialkyl esters of isophthalic acid, naphthalene-2,6-dicarboxylic acid, (C 1 -C 4 ) dialkyl esters of naphthalene 2-6-dicarboxylic acid, cyclohexanedicarboxylic acid, cyclohexanediacetic acid, diphenyl-4,4′-dicarboxylic acid, succinic acid, glutaric acid, adipic acid, azelaic acid, and sebacic acid; or   wherein the hydroxyl comonomer is chosen from triethylene glycol, 1,4-cyclohexanedimethanol, propane-1,3-diol, butane-1,4-diol, pentane-1,5-diol, hexane-1,6-diol, 3-methylpentanediol-(2,4), 2-methylpentanediol-(1,4), 2,2,4-trimethylpentane-diol-(1,3), 2,5-ethylhexanediol-(1,3), 2,2-diethyl propane-diol-(1,3), hexanediol-(1,3), 1,4-di-(hydroxyethoxy)-benzene, 2,2-bis-(4-hydroxycyclohexyl)-propane, 2,4-dihydroxy-1,1,3,3-tetramethyl-cyclobutane, 2,2-bis-(3-hydroxyethoxyphenyl)-propane, and 2,2-bis-(4-hydroxypropoxyphenyl)-propane.   
     
     
         3 . A polyester according to  claim 2 , wherein the carboxylic acid comonomer is chosen from isophthalic acid and naphthalene 2-6-dicarboxylic acid; or wherein the hydroxyl comonomer is cyclohexane dimethanol. 
     
     
         4 . A polyester according to  claim 1 , wherein the polyester comprises less than 2.0 mol % of diethylene glycol. 
     
     
         5 . A polyester according to  claim 1 , wherein the polyester has an intrinsic viscosity greater than 0.65 dL/g and less than 0.77 dL/g. 
     
     
         6 . A polyester according to  claim 1 , wherein the polyester has an intrinsic viscosity greater than 0.65 dL/g and less than 0.76 dL/g. 
     
     
         7 . A polyester according to  claim 1 , comprising:
 i) a carboxylic acid component comprising at least 90 mol % terephthalic acid residues and up to 10 mol % of carboxylic acid comonomer residues;   ii) a hydroxyl component comprising from 90 to 95 mol % ethylene glycol residues and additional hydroxyl residues in an amount from 5 to 10 mol %%; wherein the additional hydroxyl residues are chosen from a) diethylene glycol residues and b) mixtures of diethylene glycol residues and hydroxyl comonomer residues;   based on 100 mol % of carboxylic acid component residues and 100 mol % of hydroxyl component residues in the polyester;   wherein at least one of the carboxylic acid and hydroxyl components comprises comonomer residues, the molar ratio of the total comonomer residues to diethylene glycol residues being 1.5:1.0 or greater; and   wherein the polyester comprises less than 1.6 mol % of diethylene glycol and has an intrinsic viscosity of less than 0.76 dL/g.   
     
     
         8 . A polymer blend comprising a polyester as claimed in  claim 1  and one or more additional polymers. 
     
     
         9 . A composition comprising a polyester as claimed in  claim 1  and one or more additives. 
     
     
         10 . A composition according to  claim 9 , wherein the one or more additives are chosen from colorants, pigments, glass fibers, impact modifiers, antioxidants, surface lubricants, denesting agents, UV light absorbing agents, metal deactivators, fillers, nucleating agents, stabilizers, flame retardants, reheat aids, crystallization aids, acetaldehyde reducing compounds, recycling release aids, oxygen scavenging materials, platelet particles, and mixtures thereof. 
     
     
         11 . An article comprising a polyester as claimed in  claim 1 . 
     
     
         12 . An article according to  claim 11 , wherein the article is a molded, extruded, or a thermoformed article. 
     
     
         13 . An article according to  claim 11 , wherein the article is a beverage container or a beverage container preform. 
     
     
         14 . An article according to  claim 12 , wherein the article is a bottle. 
     
     
         15 . A process for producing an container comprising:
 feeding crystallized particles comprising a polyester as claimed in  claim 1  to an extrusion zone;   melting the particles;   forming a sheet or molded part from the molten extruded polyester; and   processing the sheet or molded part to make a container.   
     
     
         16 . A polyester according to  claim 1 , comprising:
 i) a carboxylic acid component comprising 100 mol % terephthalic acid residues;   ii) a hydroxyl component comprising from 90 to 95 mol % ethylene glycol residues and additional hydroxyl residues in an amount from 5 to 10 mol %; wherein the additional hydroxyl residues are diethylene glycol residues and hydroxyl comonomer residues;   based on 100 mol % of carboxylic acid component residues and 100 mol % of hydroxyl component residues in the polyester;   wherein the molar ratio of the hydroxyl comonomer residues to diethylene glycol residues being 1.5:1.0 or greater; and   wherein the polyester comprises less than 1.6 mol % of diethylene glycol and has an intrinsic viscosity of less than 0.76 dL/g.