Polyester resin and resin composition for molding, and formed product thereof

Abstract

In a saturated polyester resin or a composition with the saturated polyester resin as the main component for molding, the melt viscosity at 200° C. is at least 5 dPa·s and not more than 1000 dPa·s, and the product a×b is at least 500 where a (N/cm 2 ) is the tensile breaking strength and b (%) is the tensile breaking elongation of a film shape formed product. Preferably, the polyester resin has a glass transition temperature of not more than −10° C., a melting point of at least 70° C. and not more than 200° C., and an ester group concentration of at least 1000 equivalents/10 6 g and not more than 8000 equivalents/10 6 g. A material superior in water resistance, electrical insulation, durability, working environment and productivity as a molding material for an electric electronic component having a sophisticated configuration is provided.

What is claimed is:  
     
         1 . A saturated polyester resin for molding, wherein a melt viscosity at 200° C. is at least 5 dPa·s and not more than 1000 dPa·s, and a product a×b is at least 500 where a (N/cm 2 ) is a tensile breaking strength and b (%) is a tensile breaking elongation of a film shaped formed product  
     
     
         2 . A saturated polyester resin for molding, wherein a glass transition temperature is not more than −10° C. and a melting point is at least 70° C. and not more than 200° C.  
     
     
         3 . A saturated polyester resin for molding, wherein an ester group concentration of a polyester is at least 1000 equivalents/10 6  g and not more than 8000 equivalents/10 6  g.  
     
     
         4 . A saturated polyester resin for molding, wherein at least 2 mole % of a diol component of a polyester is a polyalkylene glycol when total amounts of a diol component of the polyester is 100 mole %.  
     
     
         5 . The saturated polyester resin for molding according to  claim 4 , wherein said polyalkylene glycol is a polytetramethylene glycol having a number-average molecular weight of at least 400 and not more than 10000.  
     
     
         6 . A saturated polyester resin for molding, wherein at least 2 mole % of a diol component of a polyester is an aliphatic and/or alicyclic diol having at least 10 carbon atoms when total amounts of a diol component of the polyester is 100 mole %.  
     
     
         7 . A saturated polyester resin for molding, wherein at least 2 mole % of a dicarboxylic acid component of a polyester is an aliphatic and/or alicyclic dicarboxylic acid having at least 10 carbon atoms when total amounts of a dicarboxylic acid component of the polyester is 100 mole %.  
     
     
         8 . The saturated polyester resin for molding according to any of claims  1 - 7  wherein at least 60 mole % of a dicarboxylic acid component is terephthalic acid and/or naphthalene dicarboxylic acid, and at least 40 mole % of a diol component is 1,4-butanediol and/or ethylene glycol when respective total amounts of a dicarboxylic acid component and a diol component of the polyester are 100 mole %.  
     
     
         9 . A polyester resin composition for molding, including at least 50% by weight of a saturated polyester resin defined in any of claims  1 - 7  with respect to the entire composition.  
     
     
         10 . A polyester resin composition for molding, including a saturated polyester resin defined in any of claims  1 - 7  and an antioxidant.  
     
     
         11 . A polyester resin composition for molding, wherein a retention of a melt viscosity after a heat treatment test at 121° C. and 0.2 MPa for 100 hours is at least 70% to the melt viscosity before being subjected to the heat treatment test.  
     
     
         12 . A polyester resin composition for molding, wherein a melt viscosity at 200° C. is 5 to 1000 dPa·s, and a product a x b is at least 500 where a (N/cm 2 ) is a tensile breaking strength and b (%) is a tensile breaking elongation of a film shaped formed product.  
     
     
         13 . A formed product using a saturated polyester resin for molding defined in any of claims  1 - 7 .  
     
     
         14 . A formed product using a polyester resin composition for molding defined in  claim 9 .  
     
     
         15 . A formed product using a polyester resin composition for molding defined in  claim 10 .  
     
     
         16 . A formed product using a polyester resin composition for molding defined in  claim 11  or  12 .