| 摘要 |
PURPOSE:To obtain the title polyester which can give a wet process high- strength nonwoven fabric, especially, paper, comprising a specified acid component and a specified glycol component, having a polymer structure which can give a solubility constant higher than a specified value and having a strength at break of film lower than a specified value. CONSTITUTION:A polyester for binder, comprising a terephthalic acid component containing at least 75mol.% terephthalic acid component and at least 10mol.% metalosulfoisophthalic acid component and a glycol component containing at least 50mol.% pentamethylene glycol component, having a polymer structure which can give a solubility constant S>=95 and having a strength at break of film >=5kg/mm. Said solubility constant S is determined by feeding 5g of a ground polyester in 200cc of boiling water, filtering the mixture after 15min, measuring the weight of the cake, Wg, and calculating S according to S=(5-W)/5X100 and, the strength at break of films is determined by forming polyester pellets into a film (2cmX10cm), measuring the strength at break of this film at a tensile speed of 30cm/min and converting the measurement into a value per mm of thickness. |
