Stabilized aliphatic polyester compositions

• US 20060111481A1
• Filed: 06/30/2005
• Published: 05/25/2006
• Est. Priority Date: 11/19/2004
• Status: Active Grant

• Current Assignee: Eastman Chemical Company
• Original Assignee: Eastman Chemical Company
• Inventors: Pearson, Jason Clay, Irick, Gether Jr.
• Granted Patent: US 7,582,690 B2
• Time in Patent Office: Days
• US Class Current: 524/100
• CPC Class Codes: C08G 63/199 Acids or hydroxy compounds containing cycloaliphatic rings
• CPC Class Codes: C08K 5/34 Heterocyclic compounds having nitrogen in the ring
• CPC Class Codes: C08K 5/527 Cyclic esters
• CPC Class Codes: C08L 67/02 Polyesters derived from dicarboxylic acids and dihydroxy compounds C08L67/06 takes precedence

Abstract

Disclosed are stabilized aliphatic polyester compositions comprising an aliphatic polyester, a HALS, and a tris-aryl-S-triazine UV absorber that show low embrittlement, haze formation, and discoloration during weathering. Also disclosed are aliphatic polyester compositions comprising aliphatic polyester, a hindered amine light stabilizer, a triazine UV absorber, and a phosphite that exhibit low color prior to weathering but retain good clarity, color, and excellent impact strength after exposure to weathering conditions. The aliphatic polyester compositions may be used prepare shaped articles such as, for example, films, sheets, bottles, tubes, profiles, fibers, and molded articles.

Claims

1. A stabilized, aliphatic polyester composition, comprising:

(A) at least one aliphatic, thermoplastic polyester comprising residues of at least one substituted or unsubstituted, linear or branched, dicarboxylic acid selected from aliphatic dicarboxylic acids containing 2 to 18 carbon atoms and cycloaliphatic dicarboxylic acids containing 5 to 10 carbon atoms; and

residues of at least one, substituted or unsubstituted, linear or branched, diol containing 2 to 18 carbon atoms selected from aliphatic diols, polyalkylene ether glycols, and cycloaliphatic diols;

(B) at least one hindered amine light stabilizer; and

(C) at least one tris-aryl-S-triazine UV-absorber.

2. The polyester composition according to claim 1 wherein said dicarboxylic acid comprises at least one dicarboxylic acid selected from malonic, succinic, glutaric, adipic, pimelic, azelaic, sebacic, fumaric, 2,2-dimethyl glutaric, suberic, 1,3-cyclopentanedicarboxylic, 2,6-decahydronaphthalenedicarboxylic, 1,4-cyclohexanedicarboxylic, 1,12-dodecanedioic, 1,3-cyclohexanedicarboxylic, diglycolic, itaconic, maleic, and 2,5-norbornanedicarboxylic.

3. The polyester composition according to claim 2 wherein said dicarboxylic acid comprises at least one dicarboxylic acid selected from glutaric acid, diglycolic acid, succinic acid, 1,4-cyclohexanedicarboxylic acid, adipic acid, 2,6-decahydronaphthalenedicarboxylic, 1,4-cyclohexanedicarboxylic, 1,3-cyclohexanedicarboxylic, and 2,5-norbornanedicarboxylic.

4. The polyester composition according to claim 3 wherein said dicarboxylic acid comprises 1,4-cyclohexanedicarboxylic acid.

5. The polyester composition according to claim 1 wherein said:

diol comprises at least one diol selected from ethylene glycol, diethylene glycol, 1,3-propanediol, 2,2-dimethyl-1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, poly(ethylene glycol), diethylene glycol, 2,2,4-trimethyl-1,6-hexanediol, thiodiethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, 2,6-decahydronaphthalenedimethanol, 2,2,4,4-tetramethyl-1,3-cyclobutanediol, triethylene glycol, tetraethylene glycol, poly(propylene glycol), 1,4;

3,6-dianhydrosorbitol, and 4,4′

-isopropylidenedicyclohexanol.

6. The polyester composition according to claim 5 wherein said diol comprises at least one diol selected from 1,4-butanediol;

1,3-propanediol;

ethylene glycol;

1,6-hexanediol;

diethylene glycol;

1,3-cyclohexanedimethanol;

1,4-cyclohexanedimethanol;

2,6-decahydronaphthalenedimethanol; and

2,2,4,4-tetramethyl-1,3-cyclobutanediol.

7. The polyester composition according to claim 1 wherein said polyester comprises about 80 to 100 mole percent, based on the total moles of dicarboxylic acid residues, of the residues of 1,4-cyclohexanedicarboxylic acid;

1,3-cyclohexanedicarboxylic acid, or a mixture thereof; and

about 10 to 100 mole percent, based on the total moles of diol residues, of the residues of 1,4-cyclohexanedimethanol;

ethylene glycol;

diethylene glycol;

1,3-cyclohexanedimethanol;

1,4-butanediol;

2,2,4,4-tetramethyl-1,3-cyclobutanediol, or mixtures thereof.

8. The polyester composition according to claim 7 wherein said aliphatic polyester comprises about 95 to 100 mole percent, based on the total moles of dicarboxylic acid residues, of the residues of 1,4-cyclohexanedicarboxylic acid;

and about 95 to 100 mole percent, based on the total moles of diol residues, of the residues of 1,4-cyclohexanedimethanol.

9. The polyester composition according to claim 7 wherein said aliphatic polyester comprises at least one polyester selected from poly(1,3 cyclohexylenedimethylene-1,3-cyclohexanedicarboxylate), poly(1,4 cyclohexylenedimethylene-1,4-cyclohexanedicarboxylate), and poly(2,2,4,4-tetramethyl-1,3-cyclobutylene-1,4-cyclohexanedicarboxylate).

10. The polyester composition according to claim 1 which comprises about 0.05 to about 2 weight percent of said hindered amine light stabilizer, wherein said hindered amine light stabilizer is selected from one or more compounds having formulas (1-4):

11. The polyester composition according to claim 10 which comprises about 0.1 to about 1 weight percent said hindered amine light stabilizer.

12. The polyester composition according to claim 10 wherein said hindered amine light stabilizer comprises at least one compound having formula (1), wherein

R₃, R₄, R₅, and R₆ are methyl groups;

R₇ is methyl, C₈H₁₇O—

, or hydrogen; and

L₂ is C₈ alkylene.

13. The polyester composition according to claim 12 wherein R₇ is hydrogen.

14. The polyester composition according to claim 12 wherein R₇ is C₈H₁₇O—

.

15. The polyester composition according to claim 12 wherein R₇ is methyl.

16. The polyester composition according to claim 10 wherein said hindered amine light stabilizer comprises a compound having formula (2), wherein

R₃, R₄, R₅, and R₆ are methyl;

R₈ is methyl or hydrogen;

(R₉)N(R₁₀) collectively represents a morpholino group; and

L₂ is C₆ alkylene.

17. The polyester composition according to claim 10 wherein said hindered amine light stabilizer comprises a compound having formula (2), wherein

R₃, R₄, R₅, and R₆ are methyl;

R₈ and R₉ are hydrogen;

R₁₀ is 2,4,4-trimethyl-2-pentyl; and

L₂ is C₆ alkylene.

18. The polyester composition according to claim 10 wherein said hindered amine light stabilizer comprises a compound having formula (3), wherein

R₃, R₄, R₅, R₆, and R₈ are methyl;

and

R₁₁ is radical A.

19. The polyester composition according to claim 10 wherein said hindered amine light stabilizer comprises a compound having formula (4), wherein

R₃, R₄, R₅, and R₆ are methyl;

and

R₇ is hydrogen or methyl.

20. The polyester composition according to claim 1 which comprises about 0.1 to about 6 weight percent, based on the total weight of said composition, of said tris-aryl-S-triazine UV-absorber, wherein said tris-aryl-S-triazine UV-absorber comprises at least one compound represented by formula (5):

21. The polyester composition according to claim 20 wherein

R₁₃, R₁₄, R₁₅, R₁₆, R₁₇, and R₁₈ are hydrogen;

and

R₁₉ is —

OC₆H₁₃.

22. The polyester composition according to claim 20 wherein

R₁₅ and R₁₆, are hydrogen;

R₁₃, R₁₄, R₁₇, and R₁₈ are methyl; and

R₁₉ is —

OC₈H₁₇.

23. The polyester composition according to claim 20 wherein said polyester comprises about 80 to 100 mole percent, based on the total moles of dicarboxylic acid residues, of the residues of 1,4-cyclohexanedicarboxylic acid;

1,3-cyclohexanedicarboxylic acid, or a mixture thereof; and

about 10 to 100 mole percent, based on the total moles of diol residues, of the residues of 1,4-cyclohexanedimethanol;

ethylene glycol;

diethylene glycol;

1,3-cyclohexanedimethanol;

1,4-butanediol;

2,2,4,4-tetramethyl-1,3-cyclobutanediol, or mixtures thereof; and

said hindered amine light stabilizer comprises a compound having formula (2)

24. The polyester composition according to claim 23 wherein said-polyester comprises poly(1,4 cyclohexylenedimethylene-1,4-cyclohexanedicarboxylate), poly(2,2,4,4-tetramethyl-1,3-cyclobutylene-1,4-cyclohexanedicarboxylate), or mixtures thereof.

25. A stabilized, aliphatic polyester composition, comprising:

(A) at least one aliphatic, thermoplastic polyester comprising residues of at least one substituted or unsubstituted, linear or branched, dicarboxylic acid selected from aliphatic dicarboxylic acids containing 2 to 18 carbon atoms and cycloaliphatic dicarboxylic acids containing 5 to 10 carbon atoms; and

residues of at least one, substituted or unsubstituted, linear or branched, diol containing 2 to 18 carbon atoms selected from aliphatic diols, polyalkylene ether glycols, and cycloaliphatic diols;

(B) at least one hindered amine light stabilizer selected from one or more compounds having formulas (1) and (3);

wherein

R₃, R₄, R₅ and R₆ are C₁-C₂₂ alkyl;

R₇ and R₈ are independently selected from hydrogen, C₁-C₂₂ alkyl, and C₁-C₂₂ alkoxy;

Y₁ is —

O—

;

L₁ is the divalent linking group —

C(O)-L₂-C(O)—

;

L₂ is C₁-C₂₂ alkylene; and

R₁₁ is selected from hydrogen, C₁-C₂₂ alkyl, substituted C₁-C₂₂alkyl, and radical A, wherein radical A has the following structure;

wherein * designates the position of attachment;

(C) at least one tris-aryl-S-triazine UV-absorber; and

(D) at least one pentaerythritol diphosphite.

26. The polyester composition according to claim 25 which comprises about 0.1 to about 2 weight percent, based on the total weight of said composition, of said pentaerythritol diphosphite, wherein said pentaerythritol diphosphite comprises at least one compound having formula (6):

27. The polyester composition according to claim 26 wherein R₁ and R₂ are each isodecyl, octadecyl, or 2,4-di-tert-butylphenyl.

28. The polyester composition according to claim 27 wherein R₁ and R₂ are each octadecyl.

29. The polyester composition according to claim 26 where said dicarboxylic acid comprises at least one dicarboxylic acid selected from glutaric acid, diglycolic acid, succinic acid, 1,4-cyclohexanedicarboxylic acid, adipic acid, 2,6-decahydronaphthalenedicarboxylic, 1,4-cyclohexanedicarboxylic, 1,3-cyclohexanedicarboxylic, and 2,5-norbornanedicarboxylic.

30. The polyester composition according to claim 29 wherein said dicarboxylic acid comprises 1,4-cyclohexanedicarboxylic acid.

31. The polyester composition according to claim 26 wherein said diol comprises at least one diol selected from ethylene glycol, diethylene glycol, 1,3-propanediol, 2,2-dimethyl-1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, poly(ethylene glycol), diethylene glycol, 2,2,4-trimethyl-1,6-hexanediol, thiodiethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, 2,6-decahydronaphthalenedimethanol, 2,2,4,4-tetramethyl-1,3-cyclobutanediol, triethylene glycol, tetraethylene glycol, poly(propylene glycol), 1,4:

3,6-dianhydro-sorbitol, and 4,4′

-isopropylidenedicyclohexanol.

32. The polyester composition according to claim 31 wherein said diol comprises at least one diol selected from 1,4-butanediol;

1,3-propanediol;

ethylene glycol;

1,6-hexanediol;

diethylene glycol;

1,3-cyclohexanedimethanol;

1,4-cyclohexanedimethanol;

2,6-decahydronaphthalenedimethanol; and

2,2,4,4-tetramethyl-1,3-cyclobutanediol.

33. The polyester composition according to claim 26 wherein said polyester comprises about 80 to 100 mole percent, based on the total moles of dicarboxylic acid residues, of the residues of 1,4-cyclohexanedicarboxylic acid;

1,3-cyclohexanedicarboxylic acid, or a mixture thereof; and

about 10 to 100 mole percent, based on the total moles of diol residues, of the residues of 1,4-cyclohexanedimethanol;

ethylene glycol;

diethylene glycol;

1,3-cyclohexanedimethanol;

1,4-butanediol;

2,2,4,4-tetramethyl-1,3-cyclobutanediol, or mixtures thereof.

34. The polyester composition according to claim 33 wherein said aliphatic polyester comprises about 95 to 100 mole percent, based on the total moles of dicarboxylic acid residues, of the residues of 1,4-cyclohexanedicarboxylic acid;

and about 95 to 100 mole percent, based on the total moles of diol residues, of the residues of 1,4-cyclohexanedimethanol.

35. The polyester composition according to claim 33 wherein said aliphatic polyester comprises at least one polyester selected from poly(1,3 cyclohexylenedimethylene-1,3-cyclohexanedicarboxylate), poly(1,4 cyclohexylenedimethylene-1,4-cyclohexanedicarboxylate), and poly(2,2,4,4-tetramethyl-1,3-cyclobutylene-1,4-cyclohexanedicarboxylate).

36. The polyester composition according to claim 25 which comprises about 0.1 to about 1 weight percent of said hindered amine light stabilizer, based on the total weight of said composition.

37. The polyester composition according to claim 36 wherein said hindered amine light stabilizer comprises at least one compound having formula (1), wherein

R₃, R₄, R₅, and R₆ are methyl groups;

R₇ is methyl, C₈H₁₇O—

, or hydrogen; and

L₂ is C₈ alkylene.

38. The polyester composition according to claim 37 wherein R₇ is hydrogen.

39. The polyester composition according to claim 37 wherein R₇ is C₈H₁₇O—

.

40. The polyester composition according to claim 37 wherein R₇ is a methyl group.

41. The polyester composition according to claim 25 wherein said hindered amine light stabilizer comprises a compound having formula (3), wherein

R₁₁ is radical A;

and

R₃, R₄, R₅, R₆, and R₈ are methyl;

42. The polyester composition according to claim 25 which comprises about 0.1 to about 6 weight percent, based on the total weight of said composition, of said tris-aryl-S-triazine UV-absorber, wherein said tris-aryl-S-triazine UV-absorber comprises at least one compound having formula (5):

43. The polyester composition according to claim 42 wherein

R₁₃, R,₁₄, R₁₅, R₁₆, R₁₇, and R₁₈are hydrogen;

and

R₁₉ is —

OC₆H₁₃.

44. The polyester composition according to claim 42 wherein

R₁₅ and R₁₆, are hydrogen;

R₁₃, R₁₄, R₁₇, and R₁₈ are methyl; and

R₁₉ is —

OC₈H₁₇.

48. A shaped article comprising the polyester composition of claim 25.

49. The shaped article according to claim 48 which comprises a sheet, film, tube, bottle, fiber, profile, or molded object.

50. The shaped article according to claim 49 wherein said article comprises one or more layers.

45. A stabilized, aliphatic polyester composition, comprising:

(A) at least one thermoplastic, aliphatic polyester comprising about 80 to 100 mole percent, based on a total of 100 mole percent dicarboxylic acid residues, of the residues of at least one dicarboxylic acid selected from 1,4-cyclohexanedicarboxylic acid and 1,3-cyclohexanedicarboxylic acid and about 10 to 100 mole percent, based on a total of 100 mole percent diol residues, of the residues of at least one diol selected from 1,4-cyclohexanedimethanol;

ethylene glycol;

diethylene glycol;

1,3-cyclohexanedimethanol;

1,4-butanediol; and

2,2,4,4-tetramethyl-1,3-cyclobutanediol,;

(B) about 0.1 to about 2 weight percent, based on the total weight of said composition, of at least one hindered amine light stabilizer selected from compounds having formula (1)

wherein

R₃, R₄, R₅, and R₆ are methyl groups;

R₇ is methyl, C₈H₁₇O—

, or hydrogen;

Y₁ is —

O—

;

L₁ is the divalent linking group —

C(O)-L₂-C(O)—

; and

L₂ is C₈ alkylene;

(C) about 0.1 to about 6 weight percent, based on the total weight of said composition, of at least one tris-aryl-S-triazine UV-absorber selected from compounds having formula (5);

wherein

R₁₅ and R₁₆, are hydrogen;

R₁₃, R₁₄, R₁₇, and R₁₈ are hydrogen or methyl; and

R₁₉ is —

OC₆H₁₃ or —

OC₈H₁₇; and

(D) about 0.1 to about 2 weight percent, based on the total weight of said composition, of at least one pentaerythritol diphosphite selected from compounds having formula (6);

wherein

R₁ and R₂ are each isodecyl, octadecyl, or 2,4-di-tert-butylphenyl.

46. The polyester composition according to claim 45 wherein said aliphatic polyester comprises at least one polyester selected from poly(1,3 cyclohexylenedimethylene-1,3-cyclohexanedicarboxylate), poly(1,4 cyclohexylenedimethylene-1,4-cyclohexanedicarboxylate), and poly(2,2,4,4-tetramethyl-1,3-cyclobutylene-1,4-cyclohexanedicarboxylate).

47. The polyester composition according to claim 46 wherein said aliphatic polyester comprises poly(1,4 cyclohexylenedimethylene-1,4-cyclohexanedicarboxylate) and R₁ and R₂ are each octadecyl.

51. A process for the preparation of a stabilized aliphatic polyester composition, comprising blending:

(A) at least one aliphatic, thermoplastic polyester comprising residues of at least one substituted or unsubstituted, linear or branched, dicarboxylic acid selected from aliphatic dicarboxylic acids containing 2 to 18 carbon atoms and cycloaliphatic dicarboxylic acids containing 5 to 10 carbon atoms; and

residues of at least one, substituted or unsubstituted, linear or branched, diol containing 2 to 18 carbon atoms selected from aliphatic diols, polyalkylene ether glycols, and cycloaliphatic diols;

(B) about 0.1 to about 2 weight percent, based on the total weight of said composition, of at least one hindered amine light stabilizer selected from compounds having formula (1)

wherein

R₃, R₄, R₅, and R₆ are methyl groups;

R₇ is methyl, C₈H₁₇O—

, or hydrogen;

Y₁ is —

O—

;

L₁ is the divalent linking group —

C(O)-L₂-C(O)—

; and

L₂ is C₈ alkylene;

(C) about 0.1 to about 6 weight percent, based on the total weight of said composition, of at least one tris-aryl-S-triazine UV-absorber selected from compounds having formula (5);

wherein

R₁₅ and R₁₆, are hydrogen;

R₁₃, R₁₄, R₁₇, and R₁₈ are hydrogen or methyl; and

R₁₉ is —

OC₆H₁₃ or —

OC₈H₁₇; and

(D) about 0.1 to about 2 weight percent, based on the total weight of said composition, of at least one pentaerythritol diphosphite selected from compounds having formula (6);

wherein

R₁ and R₂ are each isodecyl, octadecyl, or 2,4-di-tert-butylphenyl.

52. The process according to claim 51 wherein said blending is by melt-blending.