Polyester resin compositions, polyester film, and magnetic recording medium

Abstract

A polyester composition produced without using an antimony compound as a polycondensation catalyst and including (I) a composition containing, on a weight basis, 30 ppm or less of antimony, 0.5 to 50 ppm of titanium, and 0.1 to 100 ppm of phosphorus, in which the number density of titanium-containing particles, the equivalent circular diameter of which is 1 μm or more, is less than 100/0.02 mg; and (II) a composition containing, on a weight basis, antimony, titanium and phosphorous as defined above, in which organic polymer particles are contained in amount of 0.1 to 5 wt %, the organic polymer particles having an average particle diameter determined by dynamic light scattering of 0.05 to 3 μm and containing 0.01% or less of coarse particles relative to the total number of the particles, the coarse particles having a diameter at least twice the average particle diameter.

1 - 19 . (canceled) 
     
     
         20 . A polyester resin composition comprising, on a weight basis, 30 ppm or less of antimony, 0.5 to 50 ppm of titanium, and 0.1 to 100 ppm of phosphorus, wherein organic polymer particles are contained in amount of 0.1 to 5 wt %, the organic polymer particles having an average particle diameter determined by dynamic light scattering of 0.05 to 3 μm and containing 0.01% or less of coarse particles relative to the total number of the particles, the coarse particles having a diameter at least twice the average particle diameter. 
     
     
         21 . The polyester resin composition according to  claim 20 , wherein a titanium compound is used as a polymerization catalyst. 
     
     
         22 . The polyester resin composition according to  claim 20 , comprising a titanium oxide. 
     
     
         23 . The polyester resin composition according to  claim 22 , comprising a complex oxide of titanium and silicon. 
     
     
         24 . The polyester resin composition according to  claim 20 , comprising a titanium compound having at least one substituent selected from the group consisting of functional groups represented by formulae 1 to 6 below: 
       
         
           
           
               
               
           
         
       
       (wherein R 1  to R 9  each represent hydrogen or a C 1 -C 30  hydrocarbon group). 
     
     
         25 . The polyester resin composition according to  claim 24 , wherein at least one of R 1  to R 9  in formulae 1 to 6 is a C 1 -C 30  hydrocarbon group having an alkoxy group, a hydroxyl group, a carbonyl group, an acetyl group, a carboxyl group, an ester group, or an amino group. 
     
     
         26 . The polyester resin composition according to  claim 25 , wherein at least one of R 1  to R 6  in formulae 1 to 3 is a C 1 -C 30  hydrocarbon group having a hydroxyl group, a carbonyl group, an acetyl group, a carboxyl group, or an ester group. 
     
     
         27 . The polyester resin composition according to  claim 25 , wherein at least one of R 1  to R 3  in formula 1 is a C 1 -C 30  hydrocarbon group having a carboxyl group or an ester group. 
     
     
         28 . The polyester resin composition according to  claim 25 , wherein R 7  in formula 4 is a C 1 -C 30  hydrocarbon group. 
     
     
         29 . The polyester resin composition according to  claim 28 , wherein R 7  in formula 4 represents a C 1 -C 30  hydrocarbon group having a hydroxyl group, a carbonyl group, an acetyl group, a carboxyl group, or an ester group. 
     
     
         30 . The polyester resin composition according to  claim 20 , comprising at least one phosphorus-based compound selected from the group consisting of a phosphoric acid-based compound, a phosphorous acid-based compound, a phosphonic acid-based compound, a phosphinic acid-based compound, a phosphine oxide-based compound, a phosphonous acid-based compound, a phosphinous acid-based compound, and a phosphine-based compound. 
     
     
         31 . The polyester resin composition according to  claim 30 , comprising phosphoric acid and/or a phosphate compound. 
     
     
         32 . The polyester resin composition according to  claim 30 , comprising a phosphonic acid compound and/or a phosphonate compound. 
     
     
         33 . The polyester resin composition according to  claim 32 , wherein the phosphorus-based compound is ethyl diethylphosphonoacetate. 
     
     
         34 . The polyester resin composition according to  claim 20 , wherein the molar ratio of titanium to phosphorus (Ti/P) is in the range of 0.1 to 20. 
     
     
         35 . The polyester resin composition according to  claim 20 , further comprising 5 to 100 ppm of an alkaline earth metal element on a weight basis. 
     
     
         36 . The polyester resin composition according to  claim 35 , comprising 15 to 60 ppm of magnesium on a weight basis. 
     
     
         37 . The polyester resin composition according to  claim 20 , wherein the organic polymer particles have a degree of cross-linking of at least 50%. 
     
     
         38 . The polyester resin composition according to  claim 20 , wherein the organic polymer particles are a vinylbenzene-divinylbenzene copolymer. 
     
     
         39 . The polyester resin composition according to  claim 20 , wherein 0.1 to 5 wt % of a water-soluble polymer relative to the organic polymer particles is contained. 
     
     
         40 . The polyester resin composition according to  claim 39 , wherein the water-soluble polymer has a pyrrolidone residue. 
     
     
         41 . The polyester resin composition according to  claim 20 , wherein the specific volume resistivity is in the range of 1×10 6  to 1×10 9  Ω·cm when melted. 
     
     
         42 . A polyester film comprising the polyester resin composition according to  claim 20 . 
     
     
         43 . A laminated polyester film comprising a plurality of layers at least one of which comprises the polyester resin composition according to  claim 20 . 
     
     
         44 . A magnetic recording medium, comprising the laminated polyester film according to  claim 43 . 
     
     
         45 - 52 . (canceled)