Copolyetherester compositions and articles made from these

Abstract

Copolyetherester compositions comprising a melt-mixed blend of one or more copolyetherester(s) comprising a multiplicity of recurring long chain ester units and short chain ester units joined head-to-tail through ester linkages, and (b) about 0.25 to about 15 weight percent of one or more polyhydric alcohols having more than two hydroxyl groups; wherein all weight percentages are based on the total weight of the copolyetherester composition. Molded or extruded thermoplastic articles formed from the copolyetherester compositions, wherein 2 mm test bars prepared from said copolyetherester composition, and exposed at a test temperature of 150° C. for a test period of about 120 hours, in an atmosphere of air, and tested according to according to ISO 527-2/5A method have, on average, a retention of tensile strain at break of at least 50 percent as compared with an unexposed control having identical composition and shape.

1 . A process for improving the heat resistance of a copolyetherester composition comprising the steps
 (A) adding to a melt mixer a composition comprising
 (1) a polymeric component comprising one or more copolyetherester(s) comprising a multiplicity of recurring long chain ester units and short chain ester units joined head-to-tail through ester linkages, said long chain ester units being represented by formula (I) 
   
       
         
           
           
               
               
           
         
         
           
             and said short chain ester units being represented by formula (II): 
           
         
       
       
         
           
           
               
               
           
         
         
           
             where 
             G is a divalent radical remaining after the removal of terminal hydroxy groups from a poly(alkylene oxide)glycol that has a number average molecular weight of about 400 to about 6000; 
             R is a divalent radical remaining after removal of carboxyl groups from a dicarboxylic acid that has a molecular weight of less than 300; and 
             D is a divalent radical remaining after removal of hydroxyl groups from a diol that has a molecular weight of less than 250; 
           
           wherein said copolyetherester(s) contain from about 15 to about 99 weight percent short-chain ester units and about 1 to about 85 weight percent long-chain ester units; and 
           (2) about 0.25 to about 15 weight percent of at least one polyhydric alcohol component, based on the total weight of said composition; 
         
         (B) melt mixing said composition to disperse the polyhydric alcohol component (2) in the polymeric component (1) to form a polymer compound, and 
         (C) cooling the polymer compound of step (B) to form a solid copolyetherester composition wherein 2 mm test bars made from said solid copolyetherester composition, exposed in an atmosphere of air at a test temperature of 150° C. for a test period of 120 hours, and tested according to ISO 527-2/5A have, on average, a retention of tensile strain at break of at least 50 percent compared to that of a copolyetherester composition having identical composition and shape but which has been exposed to an atmosphere of air at a test temperature of 25° C. and tested according to ISO 527-2/5A. 
       
     
     
         2 . The process of  claim 1  wherein the polyhydric alcohol is selected from the group consisting of pentaerythritol, dipentaerythritol, tripentaerythritol, di-trimethylolpropane, D-mannitol, D-sorbitol and xylitol. 
     
     
         3 . The process of  claim 1 , wherein at least 50 mole percent of the diradicals represented by R in Formula (I) and (II) are 1,4-phenylene radicals. 
     
     
         4 . The process of  claim 1 , wherein at least about 70 mole percent of the groups represented by D in Formula (II) are 1,4-butylene radicals. 
     
     
         5 . The process of  claim 1  wherein the copolyetherester composition is prepared from esters or mixtures of esters of terephthalic acid and isophthalic acid, 1,4-butanediol and poly(alkylene oxide)glycols selected from the group consisting of poly(tetramethylene oxide)glycol, poly(trimethylene oxide)glycol, ethylene oxide-capped poly(propylene oxide)glycol, and mixtures of these. 
     
     
         6 . The process of  claim 5  wherein said poly(alkylene oxide)glycol comprises poly(tetramethylene oxide)glycol. 
     
     
         7 . The process of  claim 1  wherein the composition that is added to the melt mixer comprises about 0.1 to 30 weight percent, based on the total weight of said composition of one or more additives selected from the group consisting of colorants, carbon black, nucleating agents, mold release agents, lubricants, viscosity modifiers, impact modifiers, fillers, reinforcing agents, polyester polymers, flame retardants, and combinations thereof. 
     
     
         8 . A thermoplastic article comprising a copolyetherester composition produced by the process of  claim 1 . 
     
     
         9 . A composition prepared by the process of  claim 1 , wherein the polyhydric alcohol is free of substituents selected from the group consisting of ether, carboxylic acid, carboxylic acid amide and carboxylic acid ester groups. 
     
     
         10 . A composition prepared by the process of  claim 1  wherein the polyhydric alcohol is selected from the group consisting of pentaerythritol, dipentaerythritol, tripentaerythritol, di-trimethylolpropane, D-mannitol, D-sorbitol, and xylitol. 
     
     
         11 . A thermoplastic article of  claim 8 , wherein at least 50 mole percent diradicals represented by R in Formula (I) and (II) are 1,4-phenylene radicals. 
     
     
         12 . A thermoplastic article of  claim 8  wherein at least about 70 mole percent of the groups represented by D in Formula (II) are 1,4-butylene radicals. 
     
     
         13 . A thermoplastic article of  claim 8 , wherein the copolyetheresters are prepared from esters or mixtures of esters of terephthalic acid and isophthalic acid, 1,4-butanediol and poly(alkylene oxide)glycols selected from the group consisting of poly(tetramethylene oxide)glycol, poly(trimethylene oxide)glycol, ethylene oxide-capped poly(propylene oxide)glycol, and mixtures of these. 
     
     
         14 . A thermoplastic article of  claim 13 , wherein the poly(alkylene oxide) glycol is poly(tetramethylene ether)glycol. 
     
     
         15 . A thermoplastic article of  claim 8 , wherein the copolyetherester composition comprises about 0.1 to 30 weight percent, based on the total weight of the copolyetherester composition of one or more additives selected from the group consisting of colorants, carbon black, nucleating agents, mold release agents, lubricants, viscosity modifiers, impact modifiers, fillers, reinforcing agents, polyester polymers, flame retardants and combinations thereof. 
     
     
         16 . A process of  claim 1  wherein the melt mixer is an extruder.