Biodegradable molded articles, biodegradable polyester resin compositions, and biodegradable polyester films

Abstract

The example includes a polyester resin containing a diol, an aromatic dicarboxylic acid, and an aliphatic dicarboxylic acid, and provides a biodegradable molded article with a wet hardness reduction rate of 12% to 25%. The biodegradable molded article is processed into a polyester block having a thickness of 2.5 mm, and the initial hardness of the polyester block and the wet hardness after the polyester block is immersed in water at 30 ° C for 1 hour are measured. The wet hardness reduction rate is a value obtained by dividing the difference between the initial hardness and the wet hardness by the initial hardness.

Claims

1. The material contains a biodegradable polyester resin containing diol residues, aromatic dicarboxylic acid residues, and aliphatic dicarboxylic acid residues. The wet hardness reduction rate is 12% to 25%. The biodegradable polyester resin further comprises at least one selected from the group consisting of ester polyols, polycaprolactone diols, or branching agents. The branching agent comprises at least one selected from the group consisting of trivalent or higher alcohols, anhydrides, or trivalent or higher carboxylic acids. The aforementioned wet hardness reduction rate is measured by the following measurement method: Biodegradable molded products. [Measurement method] The biodegradable molded product is processed into a polyester block having a thickness of 2.5 mm, and the initial hardness of the polyester block and the wet hardness after the polyester block has been immersed in water at 30°C for 1 hour are measured. The wet hardness reduction rate is the value obtained by dividing the difference between the initial hardness and the wet hardness by the initial hardness.

2. Further containing metal salts, The biodegradable molded article according to claim 1.

3. The polyester resin contains diol residues, aromatic dicarboxylic acid residues, and aliphatic dicarboxylic acid residues. The wet hardness reduction rate is 12% to 25%. The polyester resin further comprises at least one selected from the group consisting of ester polyols, polycaprolactone diols, or branching agents. The branching agent comprises at least one selected from the group consisting of trivalent or higher alcohols, anhydrides, or trivalent or higher carboxylic acids. The aforementioned wet hardness reduction rate is measured by the following measurement method: Biodegradable polyester resin composition. [Measurement method] The biodegradable polyester resin composition is dried at a temperature of 80°C, placed in a stainless steel frame, and compressed at a temperature of 210°C and a pressure of 10 MPa for 3 minutes to produce a polyester block having a thickness of 2.5 mm. The initial hardness of the polyester block and the wet hardness after the polyester block has been immersed in 30°C water for 1 hour are measured, and the wet hardness reduction rate is the difference between the initial hardness and the wet hardness divided by the initial hardness.

4. The initial hardness is 30 to 45 on the Shore D hardness scale. The aforementioned wet hardness is 25 to 40 on the Shore D hardness scale. The biodegradable polyester resin composition according to claim 3.

5. The aforementioned wet hardness reduction rate is 13% to 22%. The biodegradable polyester resin composition according to claim 3.

6. The nitrogen content is 0.1 ppm to 100 ppm based on the weight of the total composition. The biodegradable polyester resin composition according to claim 3.

7. The water contact angle of the surface of the polyester block is 65° to 90°. The biodegradable polyester resin composition according to claim 3.

8. The polarity of the surface of the polyester block is 4 mN / m to 7 mN / m. The biodegradable polyester resin composition according to claim 7.

9. The polyester resin has a ratio of 0.3 to 0.7 in which the diol is bonded between the aromatic dicarboxylic acid and the aliphatic dicarboxylic acid. The biodegradable polyester resin composition according to claim 3.

10. The proportion of the diols bonded between the aromatic dicarboxylic acids is 0.2 to 0.

3. The biodegradable polyester resin composition according to claim 9.

11. The degree of hydrolysis after one week was 35% to 60%. The degree of hydrolysis after 3 weeks is 85% or higher. The degree of hydrolysis after one week and the degree of hydrolysis after three weeks are measured by the following measurement method. The biodegradable polyester resin composition according to claim 3. [Measurement method] The degree of hydrolysis after one week is the rate of decrease in molecular weight compared to the initial value when the biodegradable polyester resin composition is left for one week under high temperature and high humidity conditions of 80°C and 100% humidity. The degree of hydrolysis after three weeks is the rate of decrease in molecular weight compared to the initial state when the biodegradable polyester resin composition is left for three weeks under high temperature and high humidity conditions of 80°C and 100% humidity.

12. The difference between the wet hardness after immersion in 30°C water for 1 hour and the wet hardness after immersion in 30°C water for 20 hours is 10% or less, based on the initial hardness. The biodegradable polyester resin composition according to claim 3.

13. The difference between the wet hardness after immersion in 30°C water for 1 hour and the wet hardness after immersion in 70°C water for 1 hour is 10% or less, based on the initial hardness. The biodegradable polyester resin composition according to claim 3.

14. The polyester resin contains diol residues, aromatic dicarboxylic acid residues, and aliphatic dicarboxylic acid residues. The first weight swelling rate is 15% or less. The polyester resin further comprises at least one selected from the group consisting of ester polyols, polycaprolactone diols, or branching agents. The branching agent comprises at least one selected from the group consisting of trivalent or higher alcohols, anhydrides, or trivalent or higher carboxylic acids. The first weight swelling rate is measured by the following measurement method: Biodegradable polyester resin composition. [Measurement method] The biodegradable polyester resin composition is dried at a temperature of 80°C, placed in a stainless steel frame, and compressed at a temperature of 210°C and a pressure of 10 MPa for 3 minutes to produce a polyester sheet having a thickness of 300 μm. The initial weight of the polyester sheet and the weight after the polyester sheet has been immersed in acetone at room temperature for 24 hours are measured, and the first weight swelling rate is the value obtained by dividing the difference between the weight after immersion and the initial weight by the initial weight.

15. The first volume swelling rate is 25% or less. The first volume swelling rate is measured by the following measurement method: The biodegradable polyester resin composition according to claim 14. [Measurement method] The initial volume of the polyester sheet and the volume of the polyester sheet after immersion in acetone at room temperature for 24 hours are measured, and the first volume swelling rate is the value obtained by dividing the difference between the volume after immersion and the initial volume by the initial volume.

16. The second weight swelling rate is 20% or less. The second weight swelling rate is measured by the following measurement method: The biodegradable polyester resin composition according to claim 14. [Measurement method] The initial weight of the polyester sheet and the weight of the polyester sheet after immersion in acetonitrile at room temperature for 24 hours are measured, and the second weight swelling rate is the value obtained by dividing the difference between the weight after immersion and the initial weight by the initial weight.

17. The second volume swelling rate is 25% or less. The second volume swelling rate is measured by the following measurement method: The biodegradable polyester resin composition according to claim 16. [Measurement method] The initial volume of the polyester sheet and the volume of the polyester sheet after immersion in acetonitrile at room temperature for 24 hours are measured, and the second volume swelling rate is the value obtained by dividing the difference between the volume after immersion and the initial volume by the initial volume.

18. The aforementioned weight swelling rate is less than 12%. The biodegradable polyester resin composition according to claim 14.

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