Process for the preparation of bisphenol bischlorocarbonic acid esters

• US 3,966,785 A
• Filed: 03/04/1975
• Issued: 06/29/1976
• Est. Priority Date: 03/06/1974
• Status: Expired due to Term

• Current Assignee: Bayer AG
• Original Assignee: Bayer AG
• Inventors: Schwarz, Hans-Helmut, Krimm, Heinrich, Schnell, Hermann
• Primary Examiner(s): Brust, Joseph Paul
• Application Number:
  US05/555,148
• Time in Patent Office: 483 Days
• Field of Search: 260/463
• US Class Current: 558/281
• CPC Class Codes: C07C 317/00 Sulfones; Sulfoxides
• CPC Class Codes: C07C 323/00 Thiols, sulfides, hydropolysulfides or polysulfides substituted by halogen, oxygen or nitrogen atoms, or by sulfur atoms not being part of thio groups
• CPC Class Codes: C07C 68/02 from phosgene or haloformates
• CPC Class Codes: C07C 69/96 Esters of carbonic or haloformic acids
• CPC Class Codes: C08G 64/04 Aromatic polycarbonates
• CPC Class Codes: C08G 71/04 Polyurethanes

Abstract

A continuous process for the preparation of a bisphenol bischlorocarbonic acid ester, wherein a hydroquinone or a bisphenol dissolved in excess alkali metal hydroxide solution is reacted with 2.5 to 5.0 mol of phosgene (per mol of the dihydroxy compound) which is dissolved in a suitable solvent for the bischlorocarbonic acid ester formed in the reaction at a pH value of at least 12 and a temperature of 0° to 50°C under vigorous mixing of the reactants and unidirectional flow conditions and the organic layer thus obtained is separated wherefrom the bisphenol bischlorocarbonic acid ester is isolated by distillation and/or crystallization.

Claims

1. A continuous process for the preparation of a bisphenol bischlorocarbonic acid ester which comprises reacting a hydroxy compound which is a hydroquinone or an aromatic dihydroxy compound of the formula ##SPC3##

wherein X is alkylene, alkylidene, cycloalkylene, cycloalkylidene, O, S, SO₂ or ##SPC4##

and R¹ and R², which may be the same or different, are each alkyl, chlorine or bromine, said hydroxy compound being dissolved in excess alkali metal hydroxide solution as the sole acid binding agent, with from 2.5 to 5.0 mol, per mol hydroxy compound, of phosgene which is dissolved in a solvent for the bischlorocarbonic acid ester formed in the reaction, at a pH of above 12 and at a temperature of from 0°

to 50°

C. under vigorous mixing of the reactants and uni-directional flow conditions, separating the organic layer thus obtained and isolating the bisphenol bischlorocarbonic acid ester therefrom by distillation, crystallization or a combination thereof.

2. The process as claimed in claim 1 wherein X is an alkylene or alkylidene having 1 to 6 carbon atoms or cycloalkylene or cycloalkylidene having 5 to 15 carbon atoms.

3. The process as claimed in claim 1 wherein at least one of R¹ and R² is alkyl having 1 to 4 carbon atoms.

4. The process as claimed in claim 1, wherein from 3.5 to 4.0 mol of phosgene are reacted with 1 mol of dihydroxy compound.

5. The process as claimed in claim 1, wherein the hydroquinone or the dihydroxy compound is dissolved in from 4 to 14 mol of a 1 to 30% aqueous alkali metal hydroxide solution.

6. The process as claimed in claim 1, wherein the dihydroxy compound is 2,2-bis-(4-hydroxyphenyl)-propane;

2,2-bis-(3,5-dichloro-4-hydroxyphenyl)-propane;

2,2-bis(3,5-dibromo-4-hydroxyphenyl)-propane;

2,2-bis-(3,5-dimethyl-4-hydroxyphenyl)-propane;

1,1-bis-(4-hydroxyphenyl)-diisopropyl benzene;

hydroquinone;

bis-(4-hydroxyphenyl)-sulphide;

bis-(4-hydroxyphenyl)-sulphone or bis-(4-hydroxyphenyl)-ether.

7. The process as claimed in claim 1, wherein the phosgene is dissolved in an aromatic hydrocarbon or chlorinated hydrocarbon.

8. The process as claimed in claim 7, wherein the solvent is benzene, toluene, xylene, methylene chloride, ethylene chloride, dichloropropane, chloroform, carbon tetrachloride, 1,2-dichloroethane, chlorobenzene or chlorotoluane.

9. The process according to claim 1, wherein the reaction is carried out in a reaction tube which is continuously charged with the solution of said dihydroxy compound and the phosgene solution at the same time and at the same height.