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Flame retardant polycarbonate compositions, method of manufacture thereof, and articles therefrom

  • US 8,691,902 B2
  • Filed: 12/08/2009
  • Issued: 04/08/2014
  • Est. Priority Date: 12/08/2008
  • Status: Active Grant
First Claim
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1. A thermoplastic polycarbonate composition comprising, based on the total weight of the thermoplastic polycarbonate composition:

  • (a) greater than 10 to less than 30 wt % of a reinforcing mineral filler, wherein the reinforcing mineral filler consists of talc; and

    (b) greater than 60 to less than 90 wt. % of a polymer component, comprising, based on the weight of the polymer component,68 to 99.9 wt. % of an aromatic polycarbonate,0.1 to 2 wt. % of a fluorinated polymer,0.1 to 5 wt. % of a silicone oil,optionally, 0.1 to 25 wt. % of an impact modifier; and

    optionally, 0.1 to 5 wt. % of an additive composition comprising an antioxidant, a mold release agent, and a stabilizer;

    wherein a molded sample of the thermoplastic polycarbonate composition hasno drips when measured in accordance with NF P 92-505 at a thickness of 1.5 mm,a smoke density index of less than 10, determined in accordance with the formula;


    SDI=(Ds max/100)+(VOF4/30)whereinSDI is the smoke density index;

    Ds max is the maximum smoke density; and

    VOF4 is the average smoke density measured over the first four minutes, and is calculated in accordance with the formula;


    ½

    Ds0+Ds1+Ds2+Ds3+½

    Ds4;

    whereinDs0 is the smoke density at 0 minutes,Ds1 is the smoke density at 1 minute,Ds2 is the smoke density at 2 minutes,Ds3 is the smoke density at 3 minutes, andDs4 is the smoke density at 4 minutes; and

    Ds max, Ds0, Ds1, Ds2, Ds3, and Ds4 are measured in accordance with NF X 10-702 at a thickness of 3 mm, and100% ductility in a multi-axial impact test at 23°

    C., measured in accordance with ISO 6603.

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