Polyester resin, production method for said polyester resin, and polyester resin composition

Abstract

There is provided a polyester resin including a 2,5-furandicarboxylic acid unit and a cyclohexanedimethanol unit in a main chain, in which the polyester resin is high in molecular weight, has heat resistance and hydrolysis resistance, and is excellent in mechanical properties and melt heat stability. There is also provided a method for producing a polyester resin having the above characteristics. A polyester resin including a 2,5-furandicarboxylic acid unit and a 1,4-cyclohexanedimethanol unit as main constituent components, wherein the following (I) and (II) are satisfied: (I) the reduced viscosity (ηsp/c) is 0.7 dL/g or more; and (II) the sum of a cyclovinylidene terminal and a methylcyclohexene terminal is 80 μeq/g or less.

1 . A polyester resin, comprising:
 a constituent unit derived from 2,5-furandicarboxylic acid; and   a constituent unit derived from a diol having 2-10 carbon atoms,   wherein the polyester resin comprises 0.5 to 1000 ppm of an alkali metal.   
     
     
         2 . The polyester resin according to  claim 1 , wherein the polyester resin has a reduced viscosity (ηsp/c) of 0.7 dL/g or more. 
     
     
         3 . The polyester resin according to  claim 1 , wherein the polyester resin has a carboxylic acid terminal of 30 μeq/g or less. 
     
     
         4 . The polyester resin according to  claim 1 , wherein the polyester resin comprises 1 ppm to 250 ppm of an alkali metal. 
     
     
         5 . A polyester resin composition, comprising:
 the polyester resin of  claim 1 .   
     
     
         6 . The polyester resin composition according to  claim 5 , further comprising:
 at least one compound selected from the group consisting of a phosphorus-based compound, a sulfur-based compound and a phenol-based compound.   
     
     
         7 . The polyester resin composition according to  claim 5 , further comprising:
 at least one compound selected from the group consisting of an epoxy-based compound, an isocyanate-based compound and a carbodiimide-based compound.   
     
     
         8 . The polyester resin composition according to  claim 5 , further comprising:
 a filler.   
     
     
         9 . A polyester resin composition, comprising:
 the polyester resin of  claim 2 .   
     
     
         10 . A polyester resin composition, comprising:
 the polyester resin of  claim 3 .   
     
     
         11 . A polyester resin composition, comprising:
 the polyester resin of  claim 4 .   
     
     
         12 . A method for producing the polyester resin of  claim 1  by melt polymerization using a dicarboxylic acid and/or a dicarboxylic acid ester, and a diol,
 wherein the dicarboxylic acid and/or the dicarboxylic acid ester comprise(s) 2,5-furandicarboxylic acid and/or 2,5-furandicarboxylic acid ester, and 
 the method comprises the following (IV) and (V): 
 (IV) performing an esterification or transesterification reaction; and thereafter, 
 (V) performing polycondensation under reduced pressure at a temperature (t1) represented by the following expression (3):
     Tm≤t 1 ≤Tm+ 15° C.   (3)
 
 
 Tm: melting point of polyester resin. 
 
     
     
         13 . The method according to  claim 12 , further comprising the following (VI):
 (VI) performing solid phase polymerization at a temperature (t2) represented by the following expression (4), after melt polymerization:
   t2≤Tm   (4)
 
   Tm: melting point of polyester resin.