Industrial Technology Research Institute

Jih-Chen Huang

I-Min Tseng

Tung-Ying Kuo

Wen-Chuan Shu

Chien-Shiun Liao

Wen-Fa Lin

Yu-Wen Chen

Chyuan Juang

Hsueh-Ying Chen

Long-Shuen Jean

The present invention provides a method for preparing polypropylene terephthalate/polyethylene terephthalate (PPT/PET) copolyester, which comprises a group of processes from (a) to (e). Process (a) comprises subjecting bis-2-hydroxyethyl terephthalate (BHET), pure terephthalic acid (PTA) and 1,3-propanediol (1,3-PDO) to undergo esterification reaction to produce BHET and bis-2-hydroxypropyl terephthalate (BHPT), and then subjecting BHET and BHPT to undergo copolymerization reaction. Process (b) comprises subjecting PTA and 1,3-PDO to undergo esterification reaction to produce BHPT, adding BHET, and then subjecting BHET and BHPT to undergo copolymerization reaction. Process (c) comprises subjecting BHET and BEPT to undergo copolymerization reaction. Process (d) comprises subjecting PTA, ethylene glycol (EG) and 1,3-PDO to undergo esterification reaction to produce BHET and BHPT, and then subjecting BHET and BHPT to undergo copolymerization reaction. Process (e) comprises subjecting BHPT, PTA and EG to undergo esterification reaction to produce BHPT and BHET, and then subjecting BHET and BHPT to undergo copolymerization reaction. The obtained preferred PPT/PET copolyester of the present invention has the following properties: intrinsic viscosity (IV)>0.6 dl/g, acid value (&mdash;COOH amount)<40 meq/kg, melting point&equals;190&deg; C.-250&deg; C., L*>60, and b*<12. Therefore, the PPT/PET copolyester of the present invention is suitable for use as fiber and engineering plastic.

Method for preparing polypropylene terephthalate/polyethylene terephtalate copolyester

The present invention provides a polyester fiber of easy dyeability. The propylene chain of polypropylene terephthalte (PPT) of easy dyeability is incorporated into the main chain of polyethylene terephthalate (PET), and a PPT/PET copolyester having both ethylene and propylene groups can thus be formed. The PPT/PET copolyester is then spun into a copolyester fiber. The copolyester fiber of the present invention can be successfully dyed with a disperse dye at a temperature below 100&deg; C. in the absence of a dye carrier.

Polyester fiber of easy dyeability

The present invention provides a novel poly(1,3-propylene terephthalate), which is prepared from reacting terephthalic acid and 1,3-propanediol in the presence of an effective catalytic amount of ethylene glycol titanate to undergo esterification to form a monomer; and polymerizing the monomer in the presence of an effective catalytic amount of antimony acetate to obtain poly(1,3-propylene terephthalate). The obtained poly(1,3-propylene terephthalate) (PPT) has an intrinsic viscosity (IV) of 0.65-0.91 dl/g, acid number (--COOH amount) of less than 40 meq/kg, and L*&gt;60. Without adding a pigment, the yellowness b* of PPT is below 9, even below 5. The yellowness b* of PPT even reaches below 3 when a pigment is incorporated.

Poly(1,3-propylene therephthalate)

A method for preparing polyether glycol is disclosed. An ester end-capped polyalkylene ether and an alcohol are subjected to alcoholysis at a temperature of 35.degree.-150.degree. C. and a pressure of 1-10 atm in the presence of a mixed metal oxide as a catalyst. The mixed metal oxide includes an alkaline earth metal oxide and at least one component selected from alumina, silica, and zinc oxide.

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Hsinchu, Taiwan

Jih-Chen Huang