High strength biodegradable co-polyester resin containing cyclic aliphatic monomer and preparing method of the same

1 . A co-polyester resin comprising dicarboxylic acid,

wherein the co-polyester resin includes C 2-5 aliphatic diol and isosorbide in an amount of 70 mol to 97.5 mol and 2.5 mol to 30 mol, respectively, based on 100 mol of the dicarboxylic acid, and

the dicarboxylic acid includes C 2-6 aliphatic dicarboxylic acid and cyclic aromatic dicarboxylic acid,

wherein the co-polyester resin comprises a compound represented by formula 1 below:

(wherein in above formula 1,

x is 49 to 95, y is 2.5 to 21, and z is 2.5 to 21,

l is 2.5 to 21, m is 0.05 to 9, and n is 0.05 to 9, and

a sum of x, y, z, l, m, and n is 100).

2 . The co-polyester resin of claim 1 , wherein biodegradability is increased as a content of the C 2-5 aliphatic diol and/or the C 2-6 aliphatic dicarboxylic acid is increased.

3 . The co-polyester resin of claim 1 , wherein mechanical strength is increased as a content of the isosorbide and/or the cyclic aromatic dicarboxylic acid is increased.

4 . The co-polyester resin of claim 3 , wherein the isosorbide is comprised in an amount of greater than 3 mol to less than 10 mol.

5 . The co-polyester resin of claim 1 , wherein the dicarboxylic acid comprises the C 2-6 aliphatic dicarboxylic acid and the cyclic aromatic dicarboxylic acid at a molar ratio of 70:2.5 to 97.5:30.

6 . A biodegradable film comprising a co-polyester resin according to claim 1 .

7 . A polyester fiber comprising a co-polyester resin according to claim 1 .

8 . A method for preparing a co-polyester resin, the method comprising:

mixing C 2-5 aliphatic diol, isosorbide and dicarboxylic acid to perform an esterification reaction; and

adding a catalyst and a thermal stabilizer to a compound produced in the esterification reaction to perform a condensation reaction,

wherein the co-polyester resin comprises a compound represented by formula 1 below:

(wherein in above formula 1, x is 49 to 95, y is 2.5 to 21, and z is 2.5 to 21, l is 2.5 to 21, m is 0.05 to 9, and n is 0.05 to 9, and sum of x, y, z, l, m, and n is 100).

9 . The method of claim 8 , wherein the catalyst comprises titanium alkoxide.

10 . The method of claim 8 , wherein the thermal stabilizer is selected from the group consisting of phosphorous acid, phosphoric acid, phosphorous ester, phosphate ester, and combinations thereof.

11 . The method of claim 8 , wherein the esterification reaction is performed in a pressure range of 1.5 atm to 2.5 atm.

12 . The method of claim 8 , wherein the esterification reaction is performed in a temperature range of 180° C. to 210° C.

13 . The method of claim 8 , wherein the condensation reaction is performed in a pressure range of 0.5 torr to 1 torr.

14 . The method of claim 8 , wherein the condensation reaction is performed in a temperature range of 230° C. to 260° C.