×

Poly(ester-carbonates) from dicarboxylic acid chlorides

  • US 4,194,038 A
  • Filed: 01/25/1979
  • Issued: 03/18/1980
  • Est. Priority Date: 01/25/1979
  • Status: Expired due to Term
First Claim
Patent Images

1. In a process for production of poly(ester-carbonate) of dihydric phenol and of aromatic or cycloaliphatic dicarboxylic acid from a reaction mixture containing dichloride of at least one such acid, dissolved in a chlorinated hydrocarbon solvent inert under the reaction conditions having from 1 to 6 carbon atoms and from 1 to 4 chlorine atoms, said process employing a tertiary nitrogen base, having pKb in aqueous solution at 25°

  • C. in the range 7-11, to catalyze condensation of such dihydric phenol with said dichloride and with phosgene employed as carbonate precursor, and to serve as HCl acceptor for the HCl generated in said condensation reactions;

    the improvement which comprises;

    (1) Feeding at least one such dihydric phenol into said dichloride solution at temperature in the range 0°

    -100°

    C., said dichloride solution containing at the start of said condensation reaction, phosgene in the range between 10% and 50% of the stoichiometric proportion of phosgene;

    total dihydric phenol required for formation of the poly(ester-carbonate) final product with the desired mol ratio in the range 1.00;

    0.05 up to 1.00;

    0.70 of dihydric phenol;

    dichloride residues;

    (2) Concurrently with the feeding of dihydric phenol, agitating the reaction mixture and feeding phosgene in a separate stream thereto, until all dihydric phenol for the reaction has been added and at least 80% but not over 97% of the stoichiometrically required phosgene for reaction with all hydroxyl groups has been added;

    (3) Maintaining during the feeding of dihydric phenol, at least a 10% molar excess of tertiary nitrogen base over that required by stoichiometry;

    (4) Then allowing time for the condensation reaction forming poly(ester-carbonate) to come essentially to completion while the phosgene added is being brought at least to the stoichiometrically required quantity for reaction with all hydroxyl groups.

View all claims
  • 0 Assignments
Timeline View
Assignment View
    ×
    ×