Polyester container and manufacturing method therefor
The present invention relates to a polyester container. The polyester container is formed from a polyester resin containing a particular content of diol moieties derived from isosorbide and diethylene glycol, and thus can show high transparency in spite of a great wall thickness thereof.
1. A polyester container made of a polyester resin that is polymerized with a dicarboxylic acid including terephthalic acid or a derivative thereof and a diol including isosorbide and ethylene glycol, thereby having an alternating structure of an acid moiety derived from the dicarboxylic acid or a derivative thereof and a diol moiety derived from the diol,
wherein the polyester resin includes 6 mol % to 12 mol % of a diol moiety derived from isosorbide, 2 mol % to 5 mol % of a diol moiety derived from diethylene glycol, and remainder of a diol moiety derived from ethylene glycol, based on the total diol moieties derived from the diol,
wherein the polyester resin is prepared by a polycondensation reaction and a solid phase polymerization such that the intrinsic viscosity after the solid phase polymerization, which is measured at 35° C. after dissolving the polymer in orthochlorophenol at a concentration of 1.2 g/dl at 150° C. for 15 minutes, reaches a value of 0.25 dl/g to 0.40 dl/g higher than the intrinsic viscosity of the resin obtained by the polycondensation reaction,
wherein the intrinsic viscosity of the resin obtained by the polycondensation reaction is 0.60 dl/g to 0.75 dl/g, and the intrinsic viscosity after the solid phase is polymerization 0.85 dl/g to 1.0 dl/g,
wherein a melting point exists during the first scan through a differential scanning calorimetry (DSC),
wherein a haze is 1.5% or less as measured according to ASTM D1003-97 for a specimen having a thickness of 6 mm obtained from the polyester resin, and
wherein the polyester resin has a weight average molecular weight of 70,000 g/mol to 150,000 g/mol.
2. The polyester container of claim 1 , wherein the dicarboxylic acid or a derivative thereof is a dicarboxylic acid or a derivative thereof other than terephthalic acid or a derivative thereof, which includes at least one selected from the group consisting of an aromatic dicarboxylic acid having 8 to 14 carbon atoms or a derivative thereof and an aliphatic dicarboxylic acid having 4 to 12 carbon atoms or a derivative thereof in an amount of 0 to 50 mol % based on the total dicarboxylic acids or derivatives thereof.
3. The polyester container of claim 1 , wherein the polyester container is made of the polyester resin having a number average molecular weight of 15,000 to 50,000 g/mol.
4. The polyester container of claim 1 , wherein the polyester container is made of the polyester resin having a molecular weight distribution of 2.5 to 4.0.
5. The polyester container of claim 1 , wherein the polyester container is made of the polyester resin having a melting point of 200° C. to 250° C. as measured during the first scan through a differential scanning calorimetry (DSC).
6. The polyester container of claim 1 , wherein the polyester container is made of the polyester resin having a glass transition temperature of 85° C. or more.
7. The polyester container of claim 1 , wherein the polyester container is used for a bottle, a hot fill jar or a high-pressure vessel.
8. The polyester container of claim 1 , having a wall thickness of 4.5 mm or more.
9. The polyester container of claim 1 , wherein the polyester container is molded from a preform having a wall thickness of 4.5 mm or more.