| US 7,615,605 B2 | ||
| Monomer solution for producing polycarbonate | ||
| Hans-Peter Brack, Herrliberg (Switzerland); Maarten Antoon Jan Campman, Churra-Murcia (Spain); Yohana Perez de Diego, Murcia (Spain); and Dennis James Patrick Maria Willemse, Standdaarbuiten (Netherlands) | ||
| Assigned to Sabic Innovative Plastics IP B.V., Bergen op Zoom (Netherlands) | ||
| Filed on Sep. 19, 2008, as Appl. No. 12/234,243. | ||
| Application 12/234243 is a continuation in part of application No. 12/055453, filed on Mar. 26, 2008. | ||
| Prior Publication US 2009/0247726 A1, Oct. 01, 2009 | ||
| Int. Cl. C08G 64/00 (2006.01); C08G 63/02 (2006.01) | ||
| U.S. Cl. 528—196 [422/56; 422/57; 422/62; 422/75; 436/75; 436/79; 436/85; 436/95; 436/106; 438/111; 528/198] | 35 Claims |
| 1. A method of forming a non-reactive monomer mixture suitable for use in a melt transesterification reaction to form polycarbonate,
the method comprising the steps of:
(i) selecting a first monomer compound and a second monomer compound, wherein the melting point of the second monomer compound
is greater than the melting point of the first monomer compound,
(ii) adjusting the temperature of the first monomer compound to a first temperature that is:
equal to or above the melting point of the first monomer compound, and less than the melting point of the second monomer compound;
(iii) adding the second monomer compound to the first monomer compound,
wherein the first temperature is selected such that the second monomer compound added to the first monomer compound is dispersed
in the first monomer compound to produce a non-reactive monomer mixture, and
(iv) performing a monomer conditioning step selected from the group consisting of:
(a) testing the first and second monomer compounds for the presence of alkali metal, and if said alkali metal is present in
either or both of the first and second monomer compounds, performing a step selected from the group consisting of:
(I) treating the monomer compounds which have said alkali metal present to reduce the level of said alkali metal to an amount
of less than 600 ppb,
(II) adding an acid stabilizer to the monomer compounds which have said alkali metal present, and
(III) a combination of steps (I) and (II), and
(b) treating the first and the second monomer compounds with a step selected from the group of:
(I) treating the monomer compounds to reduce the level of said alkali metal to an amount of less than 600 ppb,
(II) adding an acid stabilizer to the monomer compounds, and
(III) a combination of steps (I) and (II)
thereby forming a non-reactive monomer mixture.
|