Polyester resin and process for its production

Abstract

A polyester resin characterized in that the content of the copolymerized components other than the terephthalic acid component and the ethylene glycol component, is not more than 4 mol % based on the total dicarboxylic acid component, and when polyester resin is formed into a molded product, the molded product has a specific absorbance.

1 .- 15 . (canceled)  
   
   
       16 . A polyester resin produced by polycondensing a dicarboxylic acid component containing terephthalic acid or its ester-forming derivative as the main component, and a diol component containing ethylene glycol as the main component in the presence of (1) a compound of at least one member selected from the group consisting of titanium group elements in Group 4A of the periodic table, via an esterification reaction or an ester exchange reaction, wherein said polyester resin is obtained by melt polycondensation wherein the intrinsic viscosity ([η 1 ]) ranges from 0.35 to 0.75 dl/g as a value measured at 30° C. in a solution in a mixed solvent of phenol/tetrachloroethane (weight ratio: 1/1) and wherein the melt polycondensation velocity (V 1 ) as a value obtained by dividing the intrinsic viscosity ([η 1 ]) of the resulting polyester resin by the reaction time, is at least 0.15 dl/g/hr.  
   
   
       17 . The polyester resin according to  claim 16 , wherein the temperature-rising crystallization temperature (Tc) of the resin in the molded product after the injection molding at 280° C., is from 150 to 180° C.  
   
   
       18 . The polyester resin according to  claim 16 , wherein the resin before the injection molding is one having an intrinsic viscosity ([η]) of from 0.70 to 0.90 dl/g and a color coordinate value b of the Hunter's color difference formula of not more than 4.  
   
   
       19 . The polyester resin according to  claim 16 , wherein the content of the compound (1) is from 0.002 to 1 mol as the total amount (T) of atoms of the compound (1) per 1 ton of the polyester resin.  
   
   
       20 . The polyester resin according to  claim 19 , which is one polycondensed in the coexistence of (2) a compound of at least one element selected from the group consisting of metal elements of Group Ia of the periodic table, elements of Group IIa of the periodic table, manganese, iron and cobalt, and (3) a phosphorus compound, wherein the content of the compound (2) is from 0.04 to 5 mols as the total amount (M) of atoms of the compound (2) per 1 ton of the polyester resin, and the content of the compound (3) is from 0.02 to 4 mols as the total amount (P) of atoms of the compound (3) per 1 ton of the polyester resin.  
   
   
       21 . The polyester resin according to  claim 20 , wherein the contents of the respective compounds (1), (2) and (3) 
 are from 0.02 to 0.2 mol as the total amount (T) of atoms of the compound (1), from 0.04 to 0.6 mol as the total amount (M) of atoms of the compound (2) and from 0.02 to 0.4 mol as the total amount (P) of atoms of the compound (3), per 1 ton of the polyester resin, the acetaldehyde content (AA 1 ) is not more than 5.0 ppm, the acetaldehyde content (AA 2 ) of the resin in a molded product after injection-molded at 280° C. is not more than 20 ppm, and the haze of a molded product with a thickness of 5 mm after the injection molding at 280° C. is not more than 10%.    
   
   
       22 . The polyester resin according to  claim 16 , wherein the compound (1) is a titanium compound, the compound (2) is a magnesium compound, and the compound (3) is a phosphoric acid ester.  
   
   
       23 . The polyester resin according to  claim 16 , wherein, as a dicarboxylic acid component, from 0.1 to 3 mol % of isophthalic acid or its ester-forming derivative based on the total dicarboxylic acid component, and as a diol component, from 1 to 3 mol % of diethylene glycol based on the total diol component, are copolymerized, respectively.  
   
   
       24 . A process for producing the polyester resin according to  claim 16 , which comprises polycondensing a dicarboxylic acid component containing terephthalic acid or its ester-forming derivative as the main component, and a diol component containing ethylene glycol as the main component in the presence of (1) a compound of at least one member selected from the group consisting of titanium group elements in Group 4A of the periodic table, (2) a compound of at least one element selected from the group consisting of metal elements of Group Ia of the periodic table, elements of Group IIa of the periodic table, manganese, iron and cobalt, and (3) a phosphorus compound, via an esterification reaction or an ester exchange reaction, characterized in that the amounts of the respective compounds (1), (2) and (3) are such amounts that their contents will be from 0.02 to 0.2 mol as the total amount (T) of atoms of the compound (1), from 0.04 to 0.6 mol as the total amount (M) of atoms of the compound (2) and from 0.02 to 0.4 mol as the total amount (P) of atoms of the compound (3), per 1 ton of the polyester resin.  
   
   
       25 . The process for producing a polyester resin according to  claim 24 , wherein the ratio (P/T) of the total amount (P) of atoms of the compound (3) to the total amount (T) of atoms of the compound (1), is from 0.1 to 10.  
   
   
       26 . The process for producing a polyester resin according to  claim 24 , wherein the ratio (M/T) of the total amount (M) of atoms of the compound (2) to the total amount (T) of atoms of the compound (1), is from 0.1 to 10.  
   
   
       27 . The process for producing a polyester resin according to  claim 24 , wherein the order for addition of the respective compounds (1), (2) and (3) to the reaction system is (3), then (2) and then (1).  
   
   
       28 . The process for producing a polyester resin according to  claim 24 , wherein the compound (1) is a titanium compound, the compound (2) is a magnesium compound, and the compound (3) is a phosphoric acid ester.  
   
   
       29 . The process for producing a polyester resin according to  claim 28 , wherein the titanium compound is added to the reaction system in the form of an ethylene glycol solution having a titanium atom concentration of from 0.01 to 0.3 wt % and a water concentration of from 0.1 to 1 wt %.  
   
   
       30 . The process for producing a polyester resin according to  claim 24 , wherein from 0.1 to 3 mol % of isophthalic acid or its ester-forming derivative is used based on the total dicarboxylic acid component.  
   
   
       31 . A process for producing the polyester resin of  claim 16 , which comprises polycondensing a dicarboxylic acid component containing terephthalic acid or its ester-forming derivative as the main component and a diol component containing ethylene glycol as the main component in the presence of (1) a compound of at least one member selected from the group consisting of titanium group elements in Group 4A of the Periodic Table, via an esterification reaction or an ester exchange reaction, wherein the above compound (1) is added to an esterification reaction tank for a final stage in a multi-stage reaction apparatus or to an esterification reaction or ester exchange reaction product in a stage for transportation to a melt polycondensation step.  
   
   
       32 . The process for producing a polyester resin according to  claim 31  which comprises polycondensing terephthalic acid and ethylene glycol in the presence of (1) a compond of at least one member selected from the group consisting of titanium group elements in Group 4A of the Periodic Table, via an esterification reaction, wherein the above compound (1) is added to an esterification reaction tank for a final stage in a multi-stage reaction apparatus or to an esterification reaction product in a stage for transportation to a melt polycondensation step.  
   
   
       33 . The process for producing a polyester resin according to  claim 31 , wherein the compound (1) is added at such a stage as an esterification rate of an esterification reaction or ester exchange reaction product becomes at least 90%.  
   
   
       34 . The process for producing a polyester resin according to  claim 31 , wherein the compound (1) is added to an esterification reaction product in a stage for transportation to a melt polycondensation step.  
   
   
       35 . The process for producing a polyester resin according to  claim 31 , wherein the polycondensation is carried out in the presence of (2) a compound of at least one member selected from the group consisting of metal elements of Group 1A of the Periodic Table, elements of Group 2A of the Periodic Table, manganese, iron and cobalt and (3) a phosphorus compound.  
   
   
       36 . The process for producing a polyester resin according to  claim 35 , wherein a compound of at least one element selected from the group consisting of metal elements of Group 1A of the Periodic Table, elements of Group 2A of the Periodic Table, manganese, iron and cobalt is added to an esterification reaction tank for a final stage in a multistage reaction apparatus.  
   
   
       37 . The process for producing a polyester resin according to  claim 31 , wherein the compound (1) is a titanium compound.  
   
   
       38 . A polyester resin produced by polycondensing a dicarboxylic acid component containing terephthalic acid or its ester-forming derivative as the main component, and a diol component containing ethylene glycol as the main component in the presence of (1) a compound of at least one member selected from the group consisting of titanium group elements in Group 4A of the periodic table, via an esterification reaction or an ester exchange reaction, wherein said polyester resin is obtained by solid phase polycondensation is wherein the intrinsic viscosity ([η 2 ]) ranges from 0.70 to 0.90 dl/g as a value measured at 30° C. in a solution in a mixed solvent of phenol/tetrachloroethane (weight ratio: 1/1) and wherein the solid phase polycondensation velocity (V 2 ) as a value obtained by dividing the difference ([η 2 ]−[η 1 ]) between the intrinsic viscosity ([η 2 ]) of the obtainable solid phase polycondensation resin and the intrinsic viscosity ([η 1 ]) of the melt polycondensation resin, by the reaction time, ranges from 0.008 to 0.015 dl/g/hr.  
   
   
       39 . The polyester resin according to  claim 38 , wherein the temperature-rising crystallization temperature (Tc) of the resin in the molded product after the injection molding at 280° C., is from 150 to 180° C.  
   
   
       40 . The polyester resin according to  claim 38 , wherein the resin before the injection molding is one having an intrinsic viscosity ([η]) of from 0.70 to 0.90 dl/g and a color coordinate value b of the Hunter's color difference formula of not more than 4.  
   
   
       41 . The polyester resin according to  claim 38 , wherein the content of the compound (1) is from 0.002 to 1 mol as the total amount (T) of atoms of the compound (1) per 1 ton of the polyester resin.  
   
   
       42 . The polyester resin according to  claim 41 , which is one polycondensed in the coexistence of (2) a compound of at least one element selected from the group consisting of metal elements of Group Ia of the periodic table, elements of Group IIa of the periodic table, manganese, iron and cobalt, and (3) a phosphorus compound, wherein the content of the compound (2) is from 0.04 to 5 mols as the total amount (M) of atoms of the compound (2) per 1 ton of the polyester resin, and the content of the compound (3) is from 0.02 to 4 mols as the total amount (P) of atoms of the compound (3) per 1 ton of the polyester resin.  
   
   
       43 . The polyester resin according to  claim 42 , wherein the contents of the respective compounds (1), (2) and (3) 
 are from 0.02 to 0.2 mol as the total amount (T) of atoms of the compound (1), from 0.04 to 0.6 mol as the total amount (M) of atoms of the compound (2) and from 0.02 to 0.4 mol as the total amount (P) of atoms of the compound (3), per 1 ton of the polyester resin, the acetaldehyde content (AA 1 ) is not more than 5.0 ppm, the acetaldehyde content (AA 2 ) of the resin in a molded product after injection-molded at 280° C. is not more than 20 ppm, and the haze of a molded product with a thickness of 5 mm after the injection molding at 280° C. is not more than 10%.    
   
   
       44 . The polyester resin according to  claim 38 , wherein the compound (1) is a titanium compound, the compound (2) is a magnesium compound, and the compound (3) is a phosphoric acid ester.  
   
   
       45 . The polyester resin according to  claim 38 , wherein, as a dicarboxylic acid component, from 0.1 to 3 mol % of isophthalic acid or its ester-forming derivative based on the total dicarboxylic acid component, and as a diol component, from 1 to 3 mol % of diethylene glycol based on the total diol component, are copolymerized, respectively.  
   
   
       46 . A process for producing the polyester resin according to  claim 38 , which comprises polycondensing a dicarboxylic acid component containing terephthalic acid or its ester-forming derivative as the main component, and a diol component containing ethylene glycol as the main component in the presence of (1) a compound of at least one member selected from the group consisting of titanium group elements in Group 4A of the periodic table, (2) a compound of at least one element selected from the group consisting of metal elements of Group Ia of the periodic table, elements of Group IIa of the periodic table, manganese, iron and cobalt, and (3) a phosphorus compound, via an esterification reaction or an ester exchange reaction, characterized in that the amounts of the respective compounds (1), (2) and (3) are such amounts that their contents will be from 0.02 to 0.2 mol as the total amount (T) of atoms of the compound (1), from 0.04 to 0.6 mol as the total amount (M) of atoms of the compound (2) and from 0.02 to 0.4 mol as the total amount (P) of atoms of the compound (3), per 1 ton of the polyester resin.  
   
   
       47 . The process for producing a polyester resin according to  claim 46 , wherein the ratio (P/T) of the total amount (P) of atoms of the compound (3) to the total amount (T) of atoms of the compound (1), is from 0.1 to 10.  
   
   
       48 . The process for producing a polyester resin according to  claim 46 , wherein the ratio (M/T) of the total amount (M) of atoms of the compound (2) to the total amount (T) of atoms of the compound (1), is from 0.1 to 10.  
   
   
       49 . The process for producing a polyester resin according to  claim 46 , wherein the order for addition of the respective compounds (1), (2) and (3) to the reaction system is (3), then (2) and then (1).  
   
   
       50 . The process for producing a polyester resin according to  claim 46 , wherein the compound (1) is a titanium compound, the compound (2) is a magnesium compound, and the compound (3) is a phosphoric acid ester.  
   
   
       51 . The process for producing a polyester resin according to  claim 50 , wherein the titanium compound is added to the reaction system in the form of an ethylene glycol solution having a titanium atom concentration of from 0.01 to 0.3 wt % and a water concentration of from 0.1 to 1 wt %.  
   
   
       52 . The process for producing a polyester resin according to  claim 46 , wherein from 0.1 to 3 mol % of isophthalic acid or its ester-forming derivative is used based on the total dicarboxylic acid component.  
   
   
       53 . A process for producing the polyester resin of  claim 38 , which comprises polycondensing a dicarboxylic acid component containing terephthalic acid or its ester-forming derivative as the main component and a diol component containing ethylene glycol as the main component in the presence of (1) a compound of at least one member selected from the group consisting of titanium group elements in Group 4A of the Periodic Table, via an esterification reaction or an ester exchange reaction, wherein the above compound (1) is added to an esterification reaction tank for a final stage in a multi-stage reaction apparatus or to an esterification reaction or ester exchange reaction product in a stage for transportation to a melt polycondensation step.  
   
   
       54 . The process for producing a polyester resin according to  claim 53  which comprises polycondensing terephthalic acid and ethylene glycol in the presence of (1) a compond of at least one member selected from the group consisting of titanium group elements in Group 4A of the Periodic Table, via an esterification reaction, wherein the above compound (1) is added to an esterification reaction tank for a final stage in a multi-stage reaction apparatus or to an esterification reaction product in a stage for transportation to a melt polycondensation step.  
   
   
       55 . The process for producing a polyester resin according to  claim 53 , wherein the compound (1) is added at such a stage as an esterification rate of an esterification reaction or ester exchange reaction product becomes at least 90%.  
   
   
       56 . The process for producing a polyester resin according to  claim 53 , wherein the compound (1) is added to an esterification reaction product in a stage for transportation to a melt polycondensation step.  
   
   
       57 . The process for producing a polyester resin according to  claim 53 , wherein the polycondensation is carried out in the presence of (2) a compound of at least one member selected from the group consisting of metal elements of Group 1A of the Periodic Table, elements of Group 2A of the Periodic Table, manganese, iron and cobalt and (3) a phosphorus compound.  
   
   
       58 . The process for producing a polyester resin according to  claim 57 , wherein a compound of at least one element selected from the group consisting of metal elements of Group 1A of the Periodic Table, elements of Group 2A of the Periodic Table, manganese, iron and cobalt is added to an esterification reaction tank for a final stage in a multistage reaction apparatus.  
   
   
       59 . The process for producing a polyester resin according to  claim 53 , wherein the compound (1) is a titanium compound.  
   
   
       60 . A polyester resin produced by polycondensing a dicarboxylic acid component containing terephthalic acid or its ester-forming derivative as the main component, and a diol component containing ethylene glycol as the main component in the presence of (1) a compound of at least one member selected from the group consisting of titanium group elements in Group 4A of the periodic table, via an esterification reaction or an ester exchange reaction, wherein said polyester resin is produced via melt polycondensation and solid phase polycondensation, and wherein 
 wherein the intrinsic viscosity ([η 1 ]) of the melt polycondensation resin ranges from 0.35 to 0.75 dl/g as a value measured at 30° C. in a solution in a mixed solvent of phenol/tetrachloroethane (weight ratio: 1/1) and wherein the melt polycondensation velocity (V 1 ) as a value obtained by dividing the intrinsic viscosity ([η 1 ]) of the resulting polyester resin by the reaction time, is at least 0.15 dl/g/hr, and    wherein the intrinsic viscosity ([η 2 ]) of the solid phase polycondensation ranges from 0.70 to 0.90 dl/g as a value measured at 30° C. in a solution in a mixed solvent of phenol/tetrachloroethane (weight ratio: 1/1) and wherein the solid phase polycondensation velocity (V 2 ) as a value obtained by dividing the difference ([η 2 ]-[η 1 ]) between the intrinsic viscosity ([η 2 ]) of the obtainable solid phase polycondensation resin and the intrinsic viscosity ([η 1 ]) of the melt polycondensation resin, by the reaction time, ranges from 0.008 to 0.015 dl/g/hr.    
   
   
       61 . The polyester resin according to  claim 60 , wherein the temperature-rising crystallization temperature (Tc) of the resin in the molded product after the injection molding at 280° C., is from 150 to 180° C.  
   
   
       62 . The polyester resin according to  claim 60 , wherein the resin before the injection molding is one having an intrinsic viscosity ([η]) of from 0.70 to 0.90 dl/g and a color coordinate value b of the Hunter's color difference formula of not more than 4.  
   
   
       63 . The polyester resin according to  claim 60 , wherein the content of the compound (1) is from 0.002 to 1 mol as the total amount (T) of atoms of the compound (1) per 1 ton of the polyester resin.  
   
   
       64 . The polyester resin according to  claim 63 , which is one polycondensed in the coexistence of (2) a compound of at least one element selected from the group consisting of metal elements of Group Ia of the periodic table, elements of Group IIa of the periodic table, manganese, iron and cobalt, and (3) a phosphorus compound, wherein the content of the compound (2) is from 0.04 to 5 mols as the total amount (M) of atoms of the compound (2) per 1 ton of the polyester resin, and the content of the compound (3) is from 0.02 to 4 mols as the total amount (P) of atoms of the compound (3) per 1 ton of the polyester resin.  
   
   
       65 . The polyester resin according to  claim 64 , wherein the contents of the respective compounds (1), (2) and (3) 
 are from 0.02 to 0.2 mol as the total amount (T) of atoms of the compound (1), from 0.04 to 0.6 mol as the total amount (M) of atoms of the compound (2) and from 0.02 to 0.4 mol as the total amount (P) of atoms of the compound (3), per 1 ton of the polyester resin, the acetaldehyde content (AA 1 ) is not more than 5.0 ppm, the acetaldehyde content (AA 2 ) of the resin in a molded product after injection-molded at 280° C. is not more than 20 ppm, and the haze of a molded product with a thickness of 5 mm after the injection molding at 280° C. is not more than 10%.    
   
   
       66 . The polyester resin according to  claim 60 , wherein the compound (1) is a titanium compound, the compound (2) is a magnesium compound, and the compound (3) is a phosphoric acid ester.  
   
   
       67 . The polyester resin according to  claim 60 , wherein, as a dicarboxylic acid component, from 0.1 to 3 mol % of isophthalic acid or its ester-forming derivative based on the total dicarboxylic acid component, and as a diol component, from 1 to 3 mol % of diethylene glycol based on the total diol component, are copolymerized, respectively.  
   
   
       68 . A process for producing the polyester resin according to  claim 60 , which comprises polycondensing a dicarboxylic acid component containing terephthalic acid or its ester-forming derivative as the main component, and a diol component containing ethylene glycol as the main component in the presence of (1) a compound of at least one member selected from the group consisting of titanium group elements in Group 4A of the periodic table, (2) a compound of at least one element selected from the group consisting of metal elements of Group Ia of the periodic table, elements of Group IIa of the periodic table, manganese, iron and cobalt, and (3) a phosphorus compound, via an esterification reaction or an ester exchange reaction, characterized in that the amounts of the respective compounds (1), (2) and (3) are such amounts that their contents will be from 0.02 to 0.2 mol as the total amount (T) of atoms of the compound (1), from 0.04 to 0.6 mol as the total amount (M) of atoms of the compound (2) and from 0.02 to 0.4 mol as the total amount (P) of atoms of the compound (3), per 1 ton of the polyester resin.  
   
   
       69 . The process for producing a polyester resin according to  claim 68 , wherein the ratio (P/T) of the total amount (P) of atoms of the compound (3) to the total amount (T) of atoms of the compound (1), is from 0.1 to 10.  
   
   
       70 . The process for producing a polyester resin according to  claim 68 , wherein the ratio (M/T) of the total amount (M) of atoms of the compound (2) to the total amount (T) of atoms of the compound (1), is from 0.1 to 10.  
   
   
       71 . The process for producing a polyester resin according to  claim 68 , wherein the order for addition of the respective compounds (1), (2) and (3) to the reaction system is (3), then (2) and then (1).  
   
   
       72 . The process for producing a polyester resin according to  claim 68 , wherein the compound (1) is a titanium compound, the compound (2) is a magnesium compound, and the compound (3) is a phosphoric acid ester.  
   
   
       73 . The process for producing a polyester resin according to  claim 72 , wherein the titanium compound is added to the reaction system in the form of an ethylene glycol solution having a titanium atom concentration of from 0.01 to 0.3 wt % and a water concentration of from 0.1 to 1 wt %.  
   
   
       74 . The process for producing a polyester resin according to  claim 68 , wherein from 0.1 to 3 mol % of isophthalic acid or its ester-forming derivative is used based on the total dicarboxylic acid component.  
   
   
       75 . A process for producing the polyester resin of  claim 60 , which comprises polycondensing a dicarboxylic acid component containing terephthalic acid or its ester-forming derivative as the main component and a diol component containing ethylene glycol as the main component in the presence of (1) a compound of at least one member selected from the group consisting of titanium group elements in Group 4A of the Periodic Table, via an esterification reaction or an ester exchange reaction, wherein the above compound (1) is added to an esterification reaction tank for a final stage in a multi-stage reaction apparatus or to an esterification reaction or ester exchange reaction product in a stage for transportation to a melt polycondensation step.  
   
   
       76 . The process for producing a polyester resin according to  claim 75 , which comprises polycondensing terephthalic acid and ethylene glycol in the presence of (1) a compond of at least one member selected from the group consisting of titanium group elements in Group 4A of the Periodic Table, via an esterification reaction, wherein the above compound (1) is added to an esterification reaction tank for a final stage in a multi-stage reaction apparatus or to an esterification reaction product in a stage for transportation to a melt polycondensation step.  
   
   
       77 . The process for producing a polyester resin according to  claim 75 , wherein the compound (1) is added at such a stage as an esterification rate of an esterification reaction or ester exchange reaction product becomes at least 90%.  
   
   
       78 . The process for producing a polyester resin according to  claim 75 , wherein the compound (1) is added to an esterification reaction product in a stage for transportation to a melt polycondensation step.  
   
   
       79 . The process for producing a polyester resin according to  claim 75 , wherein the polycondensation is carried out in the presence of (2) a compound of at least one member selected from the group consisting of metal elements of Group 1A of the Periodic Table, elements of Group 2A of the Periodic Table, manganese, iron and cobalt and (3) a phosphorus compound.  
   
   
       80 . The process for producing a polyester resin according to  claim 79 , wherein a compound of at least one element selected from the group consisting of metal elements of Group 1A of the Periodic Table, elements of Group 2A of the Periodic Table, manganese, iron and cobalt is added to an esterification reaction tank for a final stage in a multistage reaction apparatus.  
   
   
       81 . The process for producing a polyester resin according to  claim 75 , wherein the compound (1) is a titanium compound.  
   
   
       82 . The polyester resin according to  claim 60 , wherein the ratio (V 2 /V 1 ) of this solid phase polycondensation velocity to the melt polycondensation velocity is within a range of from 0.04 to 0.07.