Copolymer resin composition, molded product, and method of manufacturing a copolymer resin composition

1. A copolymer resin composition comprising:

a lactic acid copolymer, the lactic acid copolymer containing monomer units represented by the following chemical formulas [1], [2], and [3],

wherein

a content of a monomer unit represented by the chemical formula [1] is 4 mol %,

a content of a monomer unit represented by the chemical formula [2] is 1 mol %,

a content of a monomer unit represented by the chemical formula [3] is 95 mol %,

a weight-average molecular weight of the lactic acid copolymer is 20,000 or more and 1,000,000 or less, and

a deflection temperature of the lactic acid copolymer under load is 65° C. or higher and 100° C. or lower at a bending stress of 1.80 MPa; and

the copolymer resin composition further comprising a crystallization nucleating agent,

wherein the crystallization nucleating agent comprises at least one of nucleating agents composed of a metal salt-type material having a phenyl group and benzoyl-type nucleating agents.

2. The copolymer resin composition as described in claim 1 , wherein a thermal decomposition retention rate of the lactic acid copolymer is 80% or more.

3. A molded product, comprising the copolymer resin composition as claimed in claim 1 , wherein the resin composition is molded by a method of injection molding within a mold temperature of 50° C. or higher and 90° C. or lower.

4. A copolymer resin composition comprising:

A lactic acid copolymer, the lactic acid copolymer containing monomer units represented by the following chemical formulas [ 1 ], [ 2 ], and [ 3 ],

a content of a monomer unit represented by the chemical formula [ 3 ] is 50 mol % or more and 95 mol % or less; and

a deflection temperature of the lactic acid copolymer under load is 65° C. or higher and 100° C. or lower at bending stress of 1.80 MPa, and

wherein a molar ratio of a monomer unit represented by the chemical formula [ 1 ] and a monomer unit represented by the chemical formula [ 2 ] in the lactic acid copolymer is in a range of 99:1 to 75:25, and

wherein the weight-average molecular weight of the lactic acid copolymer is 50,000 or higher and 800,000 or less.

5. The copolymer resin composition as described in claim 4 , wherein a thermal decomposition retention rate of the lactic acid copolymer is 80% or more.

6. The copolymer resin composition as described in claim 4 , wherein a monomer unit represented by the chemical formula [ 3 ] is either of an L-lactic acid monomer unit or a D-lactic acid monomer unit.

7. The copolymer resin composition s described in claim 4 , further comprising a crystallization nucleating agent.

8. The copolymer resin composition as described in claim 7 wherein the crystallization nucleating agent is composed of one or more selected from talc-type nucleating agents, nucleating agents composed of a metal salt-type material having a phenyl group, and benzoyl-type nucleating agents.

9. A molded product, comprising the copolymer resin composition as claimed in claim 7 , wherein the resin composition is molded by a method of injection molding within a mold temperature of 50° C. or higher and 90° C. or lower.

10. The copolymer resin composition as described in claim 4 , further comprising a thermal stabilizer and/or an anti-hydrolyzing agent.

11. The copolymer resin composition as described in claim 7 , wherein the thermal stabilizer comprises at least either one of a phenol-type antioxidant and a phosphate-type antioxidant,

12. The copolymer resin composition as described in claim 4 , further comprising a talc-type nucleating agent, a nucleating agent composed of a metal salt-type material having a phenyl group, and a benzoyl-type nucleating agent.

13. The copolymer resin composition as described in claim 4 , further comprising a phenol-type antioxidant and a phosphate-type antioxidant.

14. The copolymer resin composition as described in claim 4 , further comprising a phenol-type antioxidant, a phosphate-type antioxidant, and a carbodiimide compound-type anti-hydrolyzing agent.

15. The copolymer resin composition as described in claim 4 , wherein the weight-average molecular weight of the lactic acid copolymer is 70,000 or higher and 800,000 or less.

16. The copolymer resin composition as described in claim 4 , wherein a content of a monomer unit represented by the chemical formula [ 1 ] is about 4 mol %, a content of a monomer unit represented by the chemical formula [ 2 ] is about 1 mol %, and a content of a monomer unit represented by the chemical formula [ 3 ] is about 95 mol %.