Production of non-solid-stated polyester particles having solid-stated properties
View Patent ↗A process for producing non-solid-stated polyester polymer particles having one or more properties similar to polyester polymer particles that have undergone solid-state processing.
1. A bulk of polyethylene terephthalate (PET) particles, wherein said PET particles have the following characteristics:
(a) comprise a shell and a core, wherein said shell substantially surrounds said core, wherein at least a portion of said shell exhibits strain-induced crystallinity and at least a portion of said core exhibits spherulitic crystallinity;
(b) when measured on a first heating DSC scan, said particles have a low melting peak temperature greater than 190° C., and a melting endotherm area greater than the absolute value of 1 J/g; and
(c) a degree of crystallinity less than 44 percent.
2. The particles of claim 1 , wherein at least a portion of said particles are spheroidal.
3. The particles of claim 1 , having an onset-of-melt temperature (T om ) greater than 175° C.
4. The particles of claim 1 , wherein said particles comprise less than 10 ppmw of antimony catalyst.
5. The particles of claim 1 , wherein said particles comprise less than 100 ppmw of one or more acetaldehyde scavengers.
6. The particles of claim 5 , wherein said particles are substantially free of one or more acetaldehyde scavengers.
7. The particles of claim 1 , having an onset-of-melt temperature of greater than 175° C.
8. The particles of claim 1 , having an intrinsic viscosity (It.V.) of at least 0.70 dL/g.
9. A bulk of polyethylene terephthalate (PET) particles, wherein said PET particles have the following characteristics:
(a) comprise a shell and a core, wherein said shell substantially surrounds said core, wherein at least a portion of said shell exhibits strain-induced crystallinity and at least a portion of said core exhibits spherulitic crystallinity;
(b) when measured on a first heating DSC scan, said particles have an onset-of-melting temperature greater than 180° C. and a melting endotherm area greater than the absolute value of 1 J/g; and
(c) a degree of crystallinity less than 44 percent.
10. The particles of claim 9 , wherein at least a portion of said particles are spheroidal.
11. The particles of claim 9 , having a low melting peak temperature greater than 195° C.
12. The particles of claim 9 , wherein said particles comprise less than 10 ppmw of antimony catalyst.
13. The particles of claim 9 , wherein said particles comprise less than 100 ppmw of one or more acetaldehyde scavengers.
14. The particles of claim 13 , wherein said particles are substantially free of one or more acetaldehyde scavengers.
15. The particles of claim 9 , having an intrinsic viscosity (It.V.) of at least 0.70 dL/g.