Abstract Poly(ester/carbonates) are produced by adding phosgene to a reaction mixture of bisphenol A and terephthalic acid as ester-forming reactants, at mole ratios in the range between 2.0:0.8 and 2.0:1.3, in which the reaction medium consists essentially of pyridine, the concentration of bisphenol A plus terephthalic acid is in the range between 5 and 50 grams per 100 ml of pyridine; and the phosgene is added under agitation at a rate of at least 0.07 gm-mmole/liter.sec. The process is carried out at temperature in the range between 50 DEG C. and 115 DEG C. and not below the temperature given by the Arrhenius equation: 1nU=10-12/0.001987 T where U is phosgene feed rate in gram-moles/liter.second and T is absolute temperature of the reaction mixture (degrees Kelvin). Preferred phosgene feed rates are at least 0.13 gram-millimoles/liter.second; and preferred temperatures of the reaction mixture are between 60 DEG C. and 80 DEG C.
Inventors
👤 Robert S. Cooke
👤 Josefina T. Baker
👤 Stylianos Sifniades
Bibliographic Details
Application Number—
JurisdictionUS
Data Sourcegoogle_patents
Last Synchronized2026-10-31 07:27
CPC Classifications
C; C08; C08G; C08G63/00; C08G63/64
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
172 words
In a process for production of poly(ester/carbonate) by adding phosgene to a reaction mixture of bisphenol A ie. 2,2-bis-(4-hydroxyphenyl)propane) and terephthalic acid wherein the bisphenol A and terephthalic acid are at mole ratios in the range between 2.0:0.8 and 2.0:1.3; the reaction medium consists essentially of pyridine; the concentration of the bisphenol A plus terephthalic acid is in the range between about 5 and about 50 grams/100 milliliters of pyridine; and the phosgene reactant is added to said reaction mixture under agitation, at a rate of at least 0.07 gram-millimole/liter.second: the improvement which comprises maintaining said reaction mixture at temperature in the range between 50° C. and 115° C. and not below the temperature given by the relation with phosgene feed rate: 1nU=C-E/RT, where U is phosgene feed rate in gram-moles/liter.second, C is a constant=10, E=12 kilocalories/mole is the activation energy in the Arrhenius equation for the specific second order rate constant of the reaction of bisphenol A with terephthalic anhydride, and R=0.001987 is the gas constant in units of kilocalories/gram-mole·degree Kelvin.
Claim 2
Dependent Claim
172 words
In a process for production of poly(ester/carbonate) by adding phosgene to a reaction mixture of bisphenol A ie. 2,2-bis-(4-hydroxyphenyl)propane) and terephthalic acid wherein the bisphenol A and terephthalic acid are at mole ratios in the range between 2.0:0.8 and 2.0:1.3; the reaction medium consists essentially of pyridine; the concentration of the bisphenol A plus terephthalic acid is in the range between about 5 and about 50 grams/100 milliliters of pyridine; and the phosgene reactant is added to said reaction mixture under agitation, at a rate of at least 0.07 gram-millimole/liter.second: the improvement which comprises maintaining said reaction mixture at temperature in the range between 50° C. and 115° C. and not below the temperature given by the relation with phosgene feed rate: 1nU=C-E/RT, where U is phosgene feed rate in gram-moles/liter.second, C is a constant=10, E=12 kilocalories/mole is the activation energy in the Arrhenius equation for the specific second order rate constant of the reaction of bisphenol A with terephthalic anhydride, and R=0.001987 is the gas constant in units of kilocalories/gram-mole·degree Kelvin.
Claim 3
Dependent Claim
27 words
Process of claim 1 wherein temperature is in the range between about 60° C. and about 80° C. and phosgene feed rate is at least 0.13 gram-millimole/liter.second.