Non-volatile plasticizers and flow aids for polyesters

Abstract

The use of a specified molecular weight range of poly(alkylene ether)s, such as poly(ethylene glycol) (PEG), poly(tetramethylene glycol) (PTMG), and poly(propylene glycol) (PPG), and end-capped poly(alkylene ether)s, as plasticizers for polyesters such as poly(ethylene terephthalate) (PET), poly(propylene terephthalate) (PPT), poly(butylene terephthalate) (PBT), poly(ethylene naphthalate) (PEN), and poly(1,4-cyclohexanedimethylene terephthalate) (PCT), that are non-volatile during drying processes as well as during melt processing. Such poly(alkylene ether)s and end-capped poly(alkylene ether)s decrease the melt viscosity of the polymer matrix and depress the glass transition temperature, and thereby improve the processability of polyesters.

What is claimed is:  
     
       1. A method for reducing volatile emissions from polyester blends during drying comprising: 
       a. providing a blend having:  
       i. from about 1 to about 25 weight pphr of a poly(alkylene ether) having a number average molecular weight of from about 800 to about 6000 and represented by the formula:                    
       wherein: 
       m is an integer of from 1 to 3;  
       n is an integer of from 5 to 140;  
       X is selected from the group consisting of hydrogen, hydrocarbon, and amide having 10 carbons or less;  
       A and B are independently selected from the group consisting of alkyl, acyl, and aryl residues having from 1 to 200 carbon atoms; and  
       ii. a semi-crystalline polyester resin having melting point greater than 200° C. selected from the group consisting of poly(ethylene terephthalate), poly(propylene terephthalate), poly(butylene terephthalate), poly(ethylene naphthalate), and poly(1,4-cyclohexanedimethylene terephthalate); and  
       b. drying said polyester blend at a temperature greater than 100° C.  
     
     
       2. The method of claim  1  wherein m is 1. 
     
     
       3. The method of claim  1  wherein n is from about 10 to about 25. 
     
     
       4. The method of claim  1  wherein X is selected from the group consisting of hydrogen, methyl, ethyl, and propyl. 
     
     
       5. The method of claim  1  wherein X is hydrogen. 
     
     
       6. The method of claim  1  wherein the number average molecular weight of A and B summed is greater than about 250. 
     
     
       7. The method of claim  1  wherein A and B are independently the residue of one or more fatty acids having from 10 to 20 carbon atoms. 
     
     
       8. The method of claim  1  wherein said polyester is poly(ethylene terephthalate). 
     
     
       9. The method of claim  1  wherein said polyester is poly(1,4-cyclohexanedimethylene terephthalate). 
     
     
       10. The method of claim  1  wherein said blend further includes a phosphorous compound. 
     
     
       11. The method of claim  1  wherein said blend further includes from about 10 to about 200 pphr of reinforcing additives. 
     
     
       12. The method of claim  1  further comprising molding the polyester blend into a useful article. 
     
     
       13. A method for reducing volatile emissions from polyester blends during drying comprising: 
       a. providing a blend having:  
       i. from about 1 to about 25 weight pphr of a poly(alkylene ether) having a number average molecular weight of from about 900 to about 1600 and represented by the formula:                    
       wherein: 
       m is 1;  
       n is an integer of from 10 to 25;  
       X is selected from the group consisting of hydrogen, methyl, ethyl, and propyl;  
       A and B are independently selected from the group consisting of residues of one or more fatty acids having from 10 to 20 carbon atoms and wherein the number average molecular weight of A and B summed is greater than about 250; and  
       ii. a semi-crystalline polyester resin having melting point greater than 200° C. selected from the group consisting of poly(ethylene terephthalate), and poly(1,4-cyclohexanedimethylene terephthalate); and  
       b. drying said polyester blend at a temperature greater than 100° C.  
     
     
       14. The method of claim  13  wherein X is hydrogen. 
     
     
       15. The method of claim  13  further comprising molding the polyester blend into a useful article.