JP2006124529A5 - - Google Patents

Description

The polyethylene terephthalate of the present invention can be suitably obtained by heating polyethylene terephthalate containing 500 ppm or more of ethylene glycol at a temperature of 150 ° C. or more for 30 minutes or more. The ethylene glycol to be contained may contain a part of a condensate such as diethylene glycol.

(Raw materials used)
Polyethylene terephthalate according to the present invention is produced and terephthalic acid and ethylene glycol as raw materials. Terephthalic acid may be an ester-forming derivative such as an ester or acid anhydride with monoalcohol, and ethylene glycol may be an ester-forming derivative such as an ester with monobasic acid or a dehydration condensate. . Hereinafter, ethylene glycol may be abbreviated as EG.

Further, the ethylene glycol, Application Benefits glycol, propylene glycol, tetramethylene glycol, neopentyl glycol, hexamethylene glycol, aliphatic diols, such as dodecamethylene glycol; alicyclic glycols such as cyclohexanedimethanol; bisphenol, hydroquinone, 2 , Aromatic diols such as 2-bis (4-β-hydroxyethoxyphenyl) propanes can be used as raw materials.
Furthermore, in this invention, polyfunctional compounds, such as a trimesic acid, a trimethylol ethane, a trimethylol propane, a trimethylol methane, a pentaerythritol, can be used as a raw material.

In such a slurry, 1.005 to 1.4 mol, preferably 1.01 to 1.3 mol of ethylene glycol or an ester-forming derivative thereof is usually used with respect to 1 mol of terephthalic acid or an ester-forming derivative thereof. included.
The esterification reaction is carried out continuously or batchwise, and may be one stage or multistage. The esterification reaction is preferably carried out using an apparatus in which two or more esterification reactors are connected in series under conditions where ethylene glycol is refluxed while removing water generated by the reaction from the system using a rectification column.

  The polycondensation reaction may be performed in one stage or may be performed in a plurality of stages. For example, when the polycondensation reaction is performed in a plurality of stages, the first stage polycondensation reaction has a reaction temperature of 250 to 290 ° C., preferably 260 to 280 ° C., and a pressure of 0.07 to 0.003 MPa ( 500 to 20 Torr), preferably 0.03 to 0.004 MPa (200 to 30 Torr). The final stage polycondensation reaction is performed at a reaction temperature of 265 to 300 ° C, preferably 270 to 295 ° C, pressure Is carried out under conditions of 1 to 0.01 kPa (10 to 0.1 Torr), preferably 0.7 to 0.07 kPa (5 to 0.5 Torr).

Claims (4)

A treatment method in which polyethylene terephthalate containing 500 ppm or more of ethylene glycol is heated at a temperature of 150 ° C. or more for 30 minutes or more. Intrinsic viscosity is 0.70 dl / g or more,
The ethylene glycol content is 40 ppm or more, the ethylene trimer and terephthalic acid linear trimer (I) content is 80 ppm or more, the linear dimer (II) content is 80 ppm or more, bis Polyethylene terephthalate having a (2-hydroxyethyl) terephthalate (III) content of 60 ppm or more and a cyclic trimer content (IV) content of 0.40 wt% or less.

Furthermore, the linear trimer (I) content is 110 ppm or less, the linear dimer (II) content is 140 ppm or less, and the bis (2-hydroxyethyl) terephthalate (III) content is 140 ppm or less. The polyethylene terephthalate according to claim 2 . The molded object which consists of a polyethylene terephthalate of Claim 2 or 3 .