Poly(ester-carbonates) from dicarboxylic acid chlorides
First Claim
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.
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Abstract
A process for poly(ester-carbonates) from dihydric phenols, especially bisphenol A; aromatic or cycloaliphatic dicarboxylic acids, especially terephthalic acid; and phosgene as carbonate precursor wherein a reaction of the acid and phosgene is carried out in a first stage forming dicarboxylic acid chloride; and then phosgene and bisphenol A are added in separate streams, simultaneously during most of the second or condensation stage. Thereby only one kettle is required for carrying out the complete polymer production.
251 Citations
5 Claims
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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 Dependent Claims (2, 3, 4, 5)
- 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;
Specification