Interfacial polycarbonate preparation by adding additional solvent

Claim 2

In an interfacial process for the production of a polycarbonate resin having improved optical properties wherein a dihydric phenol or a mixture of dihydric phenols is first reacted with phosgene in contact with an organic solvent for said resin to generate polycarbonate oligomers by a phosgenation reaction and an interfacial polymerization catalyst is added to generate a polycarbonate resin by a polycondensation reaction of said oligomers, the improvement which comprises adding 25 to 125 percent by volume additional solvent based on the original amount of said solvent to the reaction after said phosgenation reaction and before said polycondensation reaction.

Claim 3

The process of claim 1 wherein the amount of said additional solvent is in the range from 40 to 100 percent by volume.

Claim 4

A process for the preparation of a polycarbonate resin having improved optical properties which comprises (A) reacting 1.1 to 1.3 moles of phosgene with a mixture of one mole of a dihydric phenol or a mixture of dihydric phenols, an aqueous alkali metal hydroxide solution, about 0 to 30% of an effective amount of an interfacial catalyst, and an organic solvent for said resin to form a reaction mixture containing polycarbonate oligomers, (B) adding to said reaction mixture 25 to 125 percent by volume additional solvent based on the original amount of said solvent, (C) adding about 70 to 100% of an effective amount of an interfacial polymerization catalyst, (D) stirring the reaction mixture containing an aqueous layer and a solvent layer for 5 to 60 minutes at a temperature in the range from 10° to 40° C. to complete the polymerization reaction, and (E) recovering the polycarbonate solution from which the polycarbonate resin is recovered.

Claim 5

A process for the preparation of a polycarbonate resin having improved optical properties which comprises (A) reacting 1.1 to 1.3 moles of phosgene with a mixture of one mole of a dihydric phenol or a mixture of dihydric phenols, an aqueous alkali metal hydroxide solution, about 0 to 30% of an effective amount of an interfacial catalyst, and an organic solvent for said resin to form a reaction mixture containing polycarbonate oligomers, (B) adding to said reaction mixture 25 to 125 percent by volume additional solvent based on the original amount of said solvent, (C) adding about 70 to 100% of an effective amount of an interfacial polymerization catalyst, (D) stirring the reaction mixture containing an aqueous layer and a solvent layer for 5 to 60 minutes at a temperature in the range from 10° to 40° C. to complete the polymerization reaction, and (E) recovering the polycarbonate solution from which the polycarbonate resin is recovered.

Claim 6

The process as set forth in claim 3 wherein the amount of additional solvent added is 40 to 100 percent by volume.

Claim 7

The process as set forth in claim 3 wherein the amount of the interfacial polymerization catalyst used is 0.05 to 5 percent by weight based on the dihydric phenol.

Claim 8

In an interfacial process for the production of a polycarbonate resin having improved optical properties wherein a dihydric phenol or a mixture of dihydric phenols is first reacted with phosgene in contact with an halogenated solvent for said resin to generate polycarbonate oligomers by a phosgenation reaction and an interfacial polymerization catalyst is added to generate a polycarbonate resin by a polycondensation reaction, the improvement which comprises adding 25 to 125 percent by volume additional solvent based on the original amount of said solvent to the reaction after said phosgenation reaction and before said polycondensation reaction.

Claim 9

In an interfacial process for the production of a polycarbonate resin having improved optical properties wherein a dihydric phenol or a mixture of dihydric phenols is first reacted with phosgene in contact with an halogenated solvent for said resin to generate polycarbonate oligomers by a phosgenation reaction and an interfacial polymerization catalyst is added to generate a polycarbonate resin by a polycondensation reaction, the improvement which comprises adding 25 to 125 percent by volume additional solvent based on the original amount of said solvent to the reaction after said phosgenation reaction and before said polycondensation reaction.

Claim 10

The process of claim 6 wherein the amount of said additional solvent is in the range from 40 to 100 percent by volume of the original amount of solvent used

Claim 11

The process of claim 6 wherein the halogenated solvent is selected from the group consisting of 1,1,2,2-tetrachloroethane, methylene chloride, 1,2-dichloroethylene, trichloromethane, and 1,1,2-trichloroethane.

Claim 12

A process for the preparation of a polycarbonate resin having improved optical properties which (A) reacting 1.1 to 1.3 moles of phosgene with a mixture of one mole of a dihydric phenol or a mixture of dihydric phenols, an aqueous alkali metal hydroxide solution, and a halogenated solvent for said resin to form a reaction mixture containing polycarbonate oligomers, (B) adding to said reacting mixture 25 to 125 percent by volume additional halogenated solvent based on the original amount of said solvent, (C) adding an effective amount of an interfacial polymerization catalyst, (D) stirring the reaction mixture containing an aqueous layer and a solvent layer for 5 to 60 minutes at a temperature in the range from 10° to 40° C. to complete the polymerization reaction, and (E) recovering the polycarbonate solution from which the polycarbonate resin is recovered.

Claim 13

A process for the preparation of a polycarbonate resin having improved optical properties which (A) reacting 1.1 to 1.3 moles of phosgene with a mixture of one mole of a dihydric phenol or a mixture of dihydric phenols, an aqueous alkali metal hydroxide solution, and a halogenated solvent for said resin to form a reaction mixture containing polycarbonate oligomers, (B) adding to said reacting mixture 25 to 125 percent by volume additional halogenated solvent based on the original amount of said solvent, (C) adding an effective amount of an interfacial polymerization catalyst, (D) stirring the reaction mixture containing an aqueous layer and a solvent layer for 5 to 60 minutes at a temperature in the range from 10° to 40° C. to complete the polymerization reaction, and (E) recovering the polycarbonate solution from which the polycarbonate resin is recovered.

Claim 14

The process as set forth in claim 9 wherein the amount of additional solvent added is 40 to 100 percent by volume.

Claim 15

The process as set forth in claim 9 wherein the amount of the interfacial polymerization catalyst used is 0.05 to 5 percent by weight based on the dihydric phenol.

Claim 16

The process as set forth in claim 9 wherein the halogenated solvent is selected from the group consisting of 1,1,2,2-tetrachloroethane, methylene chloride, 1,2-dichloroethylene, trichloromethane, and 1,1,2-trichloroethane.

Claim 17

A process for the preparation of a polycarbonate resin having improved optical properties which comprises (A) reacting 1.1 to 1.3 moles of phosgene with a mixture of one mole of a dihydric phenol or a mixture of dihydric phenols, an aqueous alkali metal hydroxide solution, about 0 to 30% of an effective amount of an interfacial catalyst, and an organic solvent for said resin to form a solvent-water reaction mixture containing about 5 to about 60 percent by weight of polycarbonate oligomers in the solvent phase, (B) adding to said reaction mixture 25 to 125 percent by volume additional solvent based on the original amount of said solvent, (C) adding about 70 to 100% of an effective amount of an interfacial polymerization catalyst, (D) stirring the reaction mixture for 5 to 60 minutes at a temperature in the range from 10° to 40° C. to complete the polymerization reaction, and (E) recovering the polycarbonate solution from which the polycarbonate resin is recovered.

Claim 18

A process for the preparation of a polycarbonate resin having improved optical properties which comprises (A) reacting 1.1 to 1.3 moles of phosgene with a mixture of one mole of a dihydric phenol or a mixture of dihydric phenols, an aqueous alkali metal hydroxide solution, about 0 to 30% of an effective amount of an interfacial catalyst, and an organic solvent for said resin to form a solvent-water reaction mixture containing about 5 to about 60 percent by weight of polycarbonate oligomers in the solvent phase, (B) adding to said reaction mixture 25 to 125 percent by volume additional solvent based on the original amount of said solvent, (C) adding about 70 to 100% of an effective amount of an interfacial polymerization catalyst, (D) stirring the reaction mixture for 5 to 60 minutes at a temperature in the range from 10° to 40° C. to complete the polymerization reaction, and (E) recovering the polycarbonate solution from which the polycarbonate resin is recovered.

Claim 19

The process as set forth in claim 13 wherein the amount of additional solvent added is 40 to 100 percent by volume.

Claim 20

The process as set forth in claim 13 wherein the amount of the interfacial polymerization catalyst used is 0.05 to 5 percent by weight based on the dihydric phenol.

Claim 21

The process of claim 13 wherein the solvent is selected from the group consisting of 1,1,2,2-tetrachloroethane, methylene chloride, 1,2-dichloroethylene, trichloromethane, and 1,1,2-trichloroethane.