Granted Patent B2

US 9,289,729 · App. 13/844,839 · Granted Mar 22, 2016

Abstract

Claims (26)

1. A method for making a composite polyamide membrane comprising a porous support and a thin film polyamide layer, wherein the method comprises the step of applying a polyfunctional amine monomer and polyfunctional acid halide monomer to a surface of the porous support and interfacially polymerizing the monomers to form a thin film polyamide layer,

wherein the method is characterized by applying a coating solution to the surface of the porous support comprising:

i) a hydrocarbon solvent:

ii) greater than 0.01 weight percent of an additional monomer comprising a carboxylic acid monomer comprising an aliphatic or aromatic moiety substituted with single carboxylic acid functional group and at least one acyl halide functional group and comprising equal to or less than 30 carbon atoms, and

iii) a tri-hydrocarbyl phosphate compound represented by Formula (I):

wherein R 1 , R 2 and R 3 are independently selected from hydrogen and hydrocarbyl groups comprising from 1 to 10 carbon atoms, with the proviso that no more than one of R 1 , R 2 and R 3 are hydrogen,

wherein the interfacial polymerization is conducted in the presence of the carboxylic acid monomer and tri-hydrocarbyl phosphate compound.

2. The method of claim 1 wherein the coating solution further comprises the polyfunctional acyl halide monomer.

3. The method of claim 2 wherein the coating solution further comprises the polyfunctional acyl halide monomer.

4. The method of claim 2 wherein the carboxylic acid monomer and tri-hydrocarbyl phosphate compound are provided in the coating solution in a molar ratio of from 1:1000 to 2:1.

5. The method of claim 2 wherein the carboxylic acid monomer and tri-hydrocarbyl phosphate compound are provided in the coating solution in a molar ratio of from 1:100 to 1:1.

6. The method of claim 1 wherein the carboxylic acid monomer is present in the coating solution at a concentration greater than its solubility limit in the hydrocarbon solvent but less than its solubility limit in the coating solution.

7. The method of claim 1 wherein the carboxylic acid monomer is present in the coating solution at a concentration greater than 0.02 weight percent.

8. The method of claim 1 wherein the carboxylic acid monomer is a mono-hydrolyzed analog of the polyfunctional monomer.

9. The method of claim 1 wherein the carboxylic acid monomer is formed in-situ within a coating solution prepared by combining water with the polyfunctional acyl halide monomer, tri-hydrocarbyl phosphate compound and a hydrocarbon solvent.

10. The method of claim 9 wherein the coating solution comprises:

i) water at a concentration of less than 1 wt %,

ii) the polyfunctional acyl halide monomer at a concentration of less than 10 wt % and

iii) the tri-hydrocarbyl phosphate compound at a concentration of less than 10 wt %.

11. The method of claim 9 wherein the coating solution comprises:

i) water at a concentration of less than 0.5 wt %,

ii) the polyfunctional acyl halide monomer at a concentration of less than 5 wt %, and

iii) the tri-hydrocarbyl phosphate compound at a concentration of less than 5 wt %.

12. The method of claim 9 wherein the coating solution comprises the polyfunctional acyl halide monomer at a molar ratio with water from 1:2 to 100:1.

13. The method of claim 9 wherein the coating solution comprises the tri-hydrocarbyl phosphate compound at a molar ratio with the polyfunctional acyl halide monomer of 100:1 to 1:1000.

14. The method of claim 9 wherein the coating solutions comprises at least 80 v/v % of the hydrocarbon solvent.

Assignments (7)