Flame retardant copolyester compositions

Abstract

The present invention relates to the combination of halogen-free flame retardant additives in a copolyester to improve the flame retardant properties of the copolyester composition while retaining clarity and impact properties, methods of making the copolyester composition and articles made from the copolyester composition. More specifically, the present invention relates to the use of a polymeric sulfonyl and phosphonate containing flame retardant compound in copolyester compositions to improve the flame retardant properties while retaining clarity, glass transition temperature, impact properties, methods of making said copolyester compositions and articles therefrom.

We claim: 
     
         1 . A copolyester composition comprising:
 (a) from greater than about 90 to about 98 wt % of the copolyester comprising
 (i) a diacid component comprising
 from 70 to 100 mole % residues of terephthalic acid, 
 from 0 to 30 mole % residues of a modifying aromatic diacid having from 8 to 12 carbon atoms, and 
 from 0 to 10 mole % residues of an aliphatic dicarboxylic acid; and 
 
 (ii) a glycol component comprising
 from 1 to 65 mole % cyclohexanedimethanol residues and 
 from 35 to 99 mole % of a modifying glycol having 2 to 20 carbon atoms; 
 
   (b) from about 2 to about 10 wt % of a flame retardant comprising a polymer comprising a sulfonyl moiety and a phenyl phosphonate moiety,   wherein the copolyester composition has a UL 94 V-0 rating, wherein the energy at maximum load is greater than about 15 Joules according to ASTM D3763;   wherein the copolyester composition has less than about 10% haze according to ASTM D1003,   wherein the wt % is based on the weight of the copolyester, wherein the total mole % of the dicarboxylic acid component is 100 mole % and the total mole % of the glycol component is 100 mole %.   
     
     
         2 . The copolyester composition according to  claim 1  wherein the copolyester composition further comprises a drip suppressant or an impact modifier or mixtures thereof. 
     
     
         3 . A method of making a copolyester composition, the method comprising blending:
 (a) from greater than about 90 to about 98 wt % of the copolyester comprising
 (i) a diacid component comprising
 from 70 to 100 mole % residues of terephthalic acid, 
 from 0 to 30 mole % residues of a modifying aromatic diacid having from 8 to 12 carbon atoms, and 
 from 0 to 10 mole % residues of an aliphatic dicarboxylic acid; and 
 
 (ii) a glycol component comprising
 from 1 to 65 mole % cyclohexanedimethanol residues and 
 from 35 to 99 mole % of a modifying glycol having 2 to 20 carbon atoms; 
 
   (b) from about 2 to about 10 wt % of a flame retardant comprising a polymer comprising a sulfonyl moiety and a phenyl phosphonate moiety,   wherein the copolyester composition has a UL 94 V-0 rating, wherein the energy at maximum load is greater than about 15 Joules according to ASTM D3763;   wherein the copolyester composition has less than about 10% haze according to ASTM D1003,   wherein the wt % is based on the weight of the copolyester, wherein the total mole % of the dicarboxylic acid component is 100 mole % and the total mole % of the glycol component is 100 mole %.   
     
     
         4 . The method of making a copolyester composition according to  claim 3 , wherein (a) the copolyester is from about 93 to about 95 wt %; and (b) the flame retardant from about 5 to about 7 wt %, wherein the copolyester composition has a UL 94 V-0 rating, and wherein the energy at maximum load is greater than about 23 Joules according to ASTM D3763. 
     
     
         5 . The method of making a copolyester composition according to  claim 3 , wherein (a) the copolyester is from about 90 to about 95 wt %; and (b) the flame retardant from about 5 to about 10 wt %, wherein the copolyester composition has a UL 94 V-0 rating, and wherein the energy at maximum load is greater than about 23 Joules according to ASTM D3763. 
     
     
         6 . The method of making a copolyester composition according to  claim 3 , wherein the copolyester composition has less than about 5% haze. 
     
     
         7 . The method of making a copolyester composition according to  claim 3 , wherein the flame retardant comprises polysulfonyldiphenylene phenyl phosphonate. 
     
     
         8 . The method of making a copolyester composition according to  claim 3 , wherein the blending comprises at least one of twin screw compounding, two-rotor continuous compounding, Banbury® batch mixer or a combination thereof. 
     
     
         9 . An article comprising a copolyester composition comprising:
 (a) from greater than about 90 to about 98 wt % of the copolyester comprising
 (i) a diacid component comprising
 from 70 to 100 mole % residues of terephthalic acid, 
 from 0 to 30 mole % residues of a modifying aromatic diacid having from 8 to 12 carbon atoms, and 
 from 0 to 10 mole % residues of an aliphatic dicarboxylic acid; and 
 
 (ii) a glycol component comprising
 from 1 to 65 mole % cyclohexanedimethanol residues and 
 from 35 to 99 mole % of a modifying glycol having 2 to 20 carbon atoms; 
 
   b) from about 2 to about 10 wt % of a flame retardant comprising a polymer comprising a sulfonyl moiety and a phenyl phosphonate moiety,   wherein the copolyester composition has a UL 94 V-0 rating, wherein the energy at maximum load is greater than about 15 Joules according to ASTM D3763;   wherein the copolyester composition has less than about 10% haze according to ASTM D1003,   wherein the wt % is based on the weight of the copolyester, wherein the total mole % of the dicarboxylic acid component is 100 mole % and the total mole % of the glycol component is 100 mole %.   
     
     
         10 . The copolyester composition according to  claim 1  or  9 , wherein the copolyester composition comprises:
 (a) from 90 to 96 wt % of the copolyester; and 
 b) from 4 to 10 wt % of the flame retardant, 
 wherein the copolyester composition has a UL 94 V-0 rating. 
 
     
     
         11 . The copolyester composition according to  claim 1  or  9 , wherein the copolyester composition comprises:
 (a) from 92 to 98 wt % of the copolyester; and 
 b) from 2 to 8 wt % of the flame retardant, 
 wherein the copolyester composition has a UL 94 V-0 rating. 
 
     
     
         12 . The copolyester composition according to  claim 1  or  9 , wherein the copolyester composition comprises:
 (a) from 92 to 96 wt % of the copolyester; and 
 b) from 4 to 8 wt % of the flame retardant, 
 wherein the copolyester composition has a UL 94 V-0 rating. 
 
     
     
         13 . The copolyester composition according to  claim 1  or  9 , wherein the copolyester composition comprises:
 (a) from about 93 to about 98 wt % of the copolyester; and 
 b) from about 5 to about 7 wt % of the flame retardant, 
 wherein the copolyester composition has a UL 94 V-0 rating. 
 
     
     
         14 . The copolyester composition according to  claim 1  or  9 , wherein the flame retardant comprises polysulfonyldiphenylene phenyl phosphonate. 
     
     
         15 . The copolyester composition according to  claim 1  or  9 , wherein the copolyester composition has less than about 5% haze. 
     
     
         16 . The copolyester composition according to  claim 1  or  9 , wherein the energy at maximum load is greater than about 23 Joules according to ASTM D3763. 
     
     
         17 . The article according to  claim 9 , wherein the article is produced by extrusion, extrusion blow molding, injection molding, blown film process or calendering. 
     
     
         18 . The article according to  claim 17 , wherein the article is a film, sheet or profile. 
     
     
         19 . A film comprising a copolyester composition comprising:
 (a) from greater than about 90 to about 98 wt % of the copolyester comprising
 (i) a diacid component comprising
 from 70 to 100 mole % residues of terephthalic acid, 
 from 0 to 30 mole % residues of a modifying aromatic diacid having from 8 to 12 carbon atoms, and 
 from 0 to 10 mole % residues of an aliphatic dicarboxylic acid; and 
 
 (ii) a glycol component comprising
 from 1 to 65 mole % cyclohexanedimethanol residues and 
 from 35 to 99 mole % of a modifying glycol having 2 to 20 carbon atoms; 
 
   (b) from about 2 to about 10 wt % of a flame retardant comprising a polymer comprising a sulfonyl moiety and a phenyl phosphonate moiety,   wherein the film has a thickness of 1-10 mils and has a VTM-0 or VTM-2 rating, and wherein the film has less than about 10% haze according to ASTM D1003,   wherein the wt % is based on the weight of the copolyester, wherein the total mole % of the dicarboxylic acid component is 100 mole % and the total mole % of the glycol component is 100 mole %.