Polyetherester

1 . A flame-retardant polymer composition comprising:

(1) at least one polymer comprising copolyetherester;

(2) aluminium diethylphosphinate;

(3) zinc diethylphosphinate; and

(4) 2 to 20 wt % of phosphite, wherein the phosphite is selected from an aluminium salt of phosphorous acid, a zinc salt of phosphorous acid, and a mixture of these,

wherein the weight percentages are based on the total weight of the composition, wherein the composition has an LOI of 20 or greater when measured according to test method ISO 4589-1/-2, using test bars in the shape of rectangular bars of dimension 125 mm long by 13 mm wide and having an average thickness of about 1.7±0.1 mm.

2 . The composition of claim 1 , wherein the copolyetherester is made by reacting a C 2 -C 6 diol with an aromatic diacid moiety and a poly(alkyleneoxide)diol.

3 . The composition of claim 1 , wherein the copolyetherester is made using a poly(alkyleneoxide)diol selected from poly(ethyleneoxide)diol, poly(propyleneoxide)diol, poly(tetramethyleneoxide)diol and mixtures of two or more of these.

4 . The composition of claim 1 , wherein the copolyetherester is made using a C 2 -C 6 diol selected from ethylene glycol, propylene glycol, butylene glycol, and mixtures of two or more of these.

5 . The composition of claim 1 , wherein the copolyetherester is made using an aromatic diacid selected from terephthalate, iso-terephthalate, and mixtures of these.

6 . The composition of claim 1 , wherein the total of aluminium diethylphosphinate and zinc diethylphosphinate is 5 to 40 wt % based on the total weight of the composition.

7 . The composition of claim 1 , comprising Al phosphite, Zn phosphite, or a mixture of these.

8 . The composition of claim 1 , comprising:

(1) at least one copolyetherester;

(2) 5 to 20 wt % aluminium diethylphosphinate;

(3) 5 to 20 wt % zinc diethylphosphinate;

(4) 2 to 10 wt % of phosphite, wherein the phosphite is selected from Al phosphite, Zn phosphite, and mixtures of these.

9 . The composition of claim 1 , wherein the ratio of LOI of the composition to LOI of the composition without the metal phosphite(s) is 0.75 or greater when measured according to test method ISO 4589-1/-2, using test bars in the shape of rectangular bars of dimension 125 mm long by 13 mm wide and having an average thickness of about 1.7±0.1 mm.

10 . The composition of claim 1 , having a D s,max /mass retained in g measured according to ISO 5659 test standard and using plaques having an area of 75 mm×75 mm and thickness of 2 mm, of not greater than 40.

11 . The composition of claim 1 , wherein the ratio of D s,max , ret of the composition to D s,max , ret of the composition without metal phosphite(s) measured according to ISO 5659 test standard and using plaques having an area of 75 mm×75 mm and thickness of 2 mm, is not greater than 0.81.

12 . The composition of claim 1 , additionally comprising (2′) 0.2 to 16 wt % of aluminum salts of ethylbutylphosphinic acid, dibutylphosphinic acid, ethylhexylphosphinic acid, butylhexylphosphinic acid, dihexylphosphinic acid, or mixtures of two or more of these.

13 . The composition of claim 1 , wherein the aluminium diethylphosphinate, the zinc diethylphosphinate, the phosphite(s), or a combination thereof has a D95 (volume %, measured using laser diffraction technology with a Malvern Mastersizer 2000 particle size analyser instrument, in acetone) of ≤10 microns.

14 . The composition of claim 1 , comprising zinc phosphite having particle sizes from 0.1 to 100 micron.

15 . The composition of claim 1 , additionally comprising at least one nitrogen-containing synergist and/or a phosphorus-containing flame retardant and/or a nitrogen-containing flame retardant.

16 . The composition of claim 1 , comprising melamine pyrophosphate.

17 . A shaped article made from the composition of claim 1 .

18 . A cable comprising a light or electrical conducting core and a sheath made from a flame-retardant composition according to claim 1 .