POLYLACTIC ACID COMPOSITION AND MOLDED ARTICLE THEREOF

• US 20110263762A1
• Filed: 11/02/2009
• Published: 10/27/2011
• Est. Priority Date: 11/05/2008
• Status: Abandoned Application

• Current Assignee: Teijin Chemicals Ltd. (Teijin Limited), Teijin Limited
• Original Assignee: Teijin Chemicals Ltd. (Teijin Limited), Teijin Limited
• Inventors: Oda, Jitsuo, Matsuno, Yuichi, Shibata, Yoshitaka, Iwai, Masahiro, Kitamura, Takuro, Doteguchi, Mitsuru, Mitsunaga, Masaki, Toyohara, Kiyotsuna
• Application Number:
  US13/127,661
• Publication Number:
  US 20110263762A1
• Time in Patent Office: Days
• US Class Current: 524/95
• CPC Class Codes: C08K 5/0091 Complexes with metal-heteroatom-bonds
• CPC Class Codes: C08K 5/13 Phenols; Phenolates
• CPC Class Codes: C08K 5/372 Sulfides , e.g. R-(S)x-R'
• CPC Class Codes: C08K 5/524 Esters of phosphorous acids, e.g. of H3PO3
• CPC Class Codes: C08K 5/527 Cyclic esters
• CPC Class Codes: C08K 5/5333 Esters of phosphonic acids
• CPC Class Codes: C08K 5/5393 Phosphonous compounds, e.g. R—P(OR')2
• CPC Class Codes: C08K 5/5399 Phosphorus bound to nitrogen
• CPC Class Codes: C08L 2666/02 Organic macromolecular compounds, natural resins, waxes or and bituminous materials
• CPC Class Codes: C08L 67/04 Polyesters derived from hydroxycarboxylic acids, e.g. lactones C08L67/06 takes precedence

Abstract

A composition comprising polylactic acid and having excellent heat stability, especially moist heat stability, and a molded article thereof.

The composition comprises 100 parts by weight of a resin component (component A) which is composed of 5 to 100 wt % of polylactic acid (component A-α) and 95 to 0 wt % of a thermoplastic resin (component A-β), 0.001 to 5 parts by weight of a phosphono-fatty acid ester (component B), 0.01 to 5 parts by weight of a phosphate metal salt (component C), 0.001 to 2 parts by weight of at least one antioxidant (component D) selected from the group consisting of a phosphite-based compound, a phosphonite-based compound, a hindered phenol-based compound and a thioether-based compound, and 0.001 to 10 parts by weight of an end-sealing agent (component E).

Claims

1. A composition comprisingparts by weight of a resin component (component A) which is composed of 5 to 100 wt % of polylactic acid (component A-α

) and 95 to 0 wt % of a thermoplastic resin (component A-β

),

0.001 to 5 parts by weight of a phosphono-fatty acid ester (component B),

0.01 to 5 parts by weight of a phosphate metal salt (component C),

0.001 to 2 parts by weight of at least one antioxidant (component D) selected from the group consisting of a phosphite-based compound, a phosphonite-based compound, a hindered phenol-based compound and a thioether-based compound, and

0.001 to 10 parts by weight of an end-sealing agent (component E).

2. The composition according to claim 1 which further comprises 0.01 to 0.3 part by weight of a hydrotalcite (component F) based on 100 parts by weight of the resin component (component A).

3. The composition according to claim 1 which further comprises 2 to 100 parts by weight of an impact modifier (component G) based on 100 parts by weight of the resin component (component A).

4. The composition according to claim 1 which further comprises at least one flame retardant (component H) selected from the group consisting of a phosphorus-based flame retardant (component H-1), a nitrogen-based flame retardant (component H-2) and a metal hydroxide compound-based flame retardant (component H-3) based on 100 parts by weight of the resin component (component A).

5. The composition according to claim 1 which further comprises 0.05 to 100 parts by weight of an inorganic filler (component I) based on 100 parts by weight of the resin component (component A).

6. The composition according to claim 1, wherein the polylactic acid (component A-α

) comprises poly-L-lactic acid (component A-α

-1) essentially composed of an L-lactic acid unit and poly-D-lactic acid (component A-α

-2) essentially composed of a D-lactic acid unit, and the weight ratio of the component A-α

-1 to the component A-α

-2 is 10;

90 to 90;

10.

7. The composition according to claim 6, wherein the poly-L-lactic acid (component A-α

-1) contains not less than 90 mol % of the L-lactic acid unit and the poly-D-lactic acid (component A-α

-2) contains not less than 90 mol % of the D-lactic acid unit.

8. The composition according to claim 1, wherein the polylactic acid (component A-α

) has a ratio of the total area consolidated melting peaks detected at the temperature zone of higher than 195°

C. to the total area of all the peaks detected during DSC measurement, to be not less than 80%.

9. The composition according to claim 1, wherein the phosphono-fatty acid ester (component B) is represented by the following formula (1).

10. The composition according to claim 1, wherein the phosphate metal salt (component C) is represented by the following formula (2) or (3).

11. The composition according to claim 1, wherein the antioxidant (component D) is a combination of a phosphite-based compound and a hindered phenol-based compound.

12. The composition according to claim 1, wherein the end-sealing agent (component E) is at least one member selected from the group consisting of a carbodiimide compound, an epoxy compound, an oxazoline compound and an oxazine compound.

13. The composition according to claim 1, wherein the thermoplastic resin (component A-β

) is at least one resin selected from the group consisting of an aromatic polyester resin (A-β

-1), a polyolefin resin (component A-β

-2), a methacrylic resin (component A-β

-3), an aromatic polycarbonate resin (component A-β

-4) and a polyacetal resin (component A-β

-5).

14. A method of producing the composition of claim 1, comprising the steps of:

(i) melt kneading together composition-1 which comprises 100 parts by weight of poly-L-lactic acid (component A-α

-1) and 0.001 to 3 parts by weight of a phosphono-fatty acid ester (component B) and composition-2 which comprises 100 parts by weight of poly-D-lactic acid (component A-α

-2) and 0.001 to 3 parts by weight of a phosphono-fatty acid ester (component B) in the presence of 0.01 to 5 parts by weight of a phosphate metal salt (component C) based on 100 parts by weight of the total of the composition-1 and the composition-2 to prepare stereocomplex polylactic acid; and

(ii) melt kneading together 100 parts by weight of a resin component (component A) which is composed of 5 to 100 wt % of the obtained stereocomplex polylactic acid (component A-α

) and 95 to 0 wt % of a thermoplastic resin (component A-β

), 0.001 to 2 parts by weight of at least one antioxidant (component D) selected from the group consisting of a phosphite-based compound, a phosphonite-based compound, a hindered phenol-based compound and a thioether-based compound and 0.001 to 10 parts by weight of an end-sealing agent (component E).

15. A molded article of the composition of claim 1.

16. The composition according to claim 2 which further comprises 2 to 100 parts by weight of an impact modifier (component G) based on 100 parts by weight of the resin component (component A).