Method for preparing bischloroformate compositions

• US 4,601,858 A
• Filed: 06/13/1985
• Issued: 07/22/1986
• Est. Priority Date: 06/13/1985
• Status: Expired due to Fees

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Shannon, Thomas G., Brunelle, Daniel J.
• Primary Examiner(s): NOT, DEFINED
• Application Number:
  US06/744,348
• Time in Patent Office: 404 Days
• Field of Search: 260/463
• US Class Current: 558/281
• CPC Class Codes: C07C 68/02 from phosgene or haloformates
• CPC Class Codes: C07C 69/96 Esters of carbonic or haloformic acids

Abstract

Bischloroformate compositions are prepared by passing gaseous phosgene into an agitated aqueous solution of a di-(alkali metal) salt of an organic dihydroxy compound such as bisphenol A, while maintaining said solution at a temperature within the range of about 0°-50° C. Phosgene passage and agitation are continued until the bischloroformate composition has precipitated. The reaction is typically complete when the pH of the aqueous phase drops below 7.

Claims

1. A method for preparing a composition comprising water-insoluble bischloroformates of organic dihydroxy compounds which comprises passing gaseous phosgene into an agitated solution consisting essentially of water and at least one di-(alkali metal) salt of said organic dihydroxy compound while maintaining said solution at a temperature within the range of about 0°

-50°

C., and continuing passage of said phosgene and agitation until said bischloroformate composition has precipitated.

2. A method according to claim 1 wherein the dihydroxy compound has the formula R¹ (OH)₂, wherein R¹ is a divalent aliphatic, alicyclic or aromatic radical.

3. A method according to claim 2 wherein R¹ has the formula

4. A method according to claim 3 wherein the temperature is in the range of about 0°

-30°

C.

5. A method according to claim 4 wherein the concentration of di-(alkali metal) salt in the solution is about 0.2-1.0 M.

6. A method according to claim 5 wherein the reaction is continued until the pH of the aqueous phase drops below 7.

7. A method according to claim 6 wherein the conditions are coordinated so as to permit phosgene addition to be completed in about 20 minutes or less.

8. A method according to claim 3 wherein A¹ and A² are p-phenylene and Y is isopropylidene.

9. A method according to claim 8 wherein the concentration of di-(alkali metal) salt in the solution is about 0.2-1.0 M.

10. A method according to claim 9 wherein the reaction is continued until the pH of the aqueous phase drops below 7.

11. A method according to claim 10 wherein the conditions are coordinated so as to permit phosgene addition to be completed in about 20 minutes or less.