Membranes

Patent metadata

Field	Value
Publication number	US-10035108-B2
Application number	US-201415026979-A
Country	US
Kind code	B2
Filing date	Sep 30, 2014
Priority date	Oct 3, 2013
Publication date	Jul 31, 2018
Grant date	Jul 31, 2018

Abstract

A composite membrane comprising: a) a porous support; b) a gutter layer; and c) a discriminating layer which satisfies Formula (1): wherein: Ø is <4; x is the arithmetic mean of N measurements of the thickness of the discriminating layer and has a value of between 30 and 150 nm; N is at least 100; x low _ meas is the thickness in nm of an individual measurement of thickness within the N measurements; x>x low _ meas >0; and n is the number of individual thickness measurements where x>x row _ meas , >0

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First claim

The invention claimed is:

1. A process for preparing a composite membrane wherein the composite membrane comprises:
a) a porous support;
b) a gutter layer; and
c) a discriminating layer which satisfies Formula (1):

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wherein:
Ø is <4;
x is the arithmetic mean of N measurements of the thickness of the discriminating layer and has a value of between 30 and 150 nm;
N is at least 100;

x low _ meas is the thickness in nm of an individual measurement of thickness within the N measurements;
x >x low _ meas >0; and
n is the number of individual thickness measurements where
x >x low _ meas >0,

the process comprising the step of applying the discriminating layer to a laminate comprising the porous support and the gutter layer, wherein a tension >200 N/m is applied to the laminate when the discriminating layer is applied thereto.

2. The process according to claim 1 wherein Ø is <2.5.

3. The process according to claim 1 wherein the discriminating layer is intermixed with the gutter layer.

4. The process according to claim 1 wherein the discriminating layer comprises a polyimide, cellulose acetate, polyethyleneoxide or polyetherimide.

5. The process according to claim 1 wherein the discriminating layer comprises a polyimide comprising trifluoromethyl groups.

6. The process according to claim 1 wherein the discriminating layer comprises a polyimide comprising groups of the Formula (2):

7. The process according to claim 1 wherein a portion of the gutter layer is present within the support and a portion of the gutter layer is outside of the support and the following conditions are satisfied:
(i) the portion of the gutter layer outside of the support has an average thickness (GL e ) of 10 nm to 900 nm; and
(ii) the portion of the gutter layer present within the support has an average thickness (GL i ) of 10% to 350% of GL e .

8. The process according to claim 7 wherein GL e is 400 to 900 nm.

9. The process according to claim 1 wherein x has a value of 40 to 100 nm.

10. The process according to claim 1 which has a dry thickness of 30 to 200 μm.

11. The process according to claim 1 wherein Ø is <2.5, the discriminating layer is intermixed with the gutter layer and the discriminating layer comprises a polyimide, cellulose acetate, polyethyleneoxide and/or polyetherimide.

12. The process according to claim 1 wherein a portion of the gutter layer is present within the support and a portion of the gutter layer is outside of the support and the following conditions are satisfied:
(i) the portion of the gutter layer outside of the support has an average thickness (GL e ) of 400 nm to 900 nm;
(ii) the portion of the gutter layer present within the support has an average thickness (GL i ) of 10% to 350% of GL e ;
(iii) x has a value of 40 to 100 nm; and
(iv) the composite membrane has a dry thickness of 30 to 200 μm.

13. The process according to claim 1 wherein a portion of the gutter layer is present within the support and a portion of the gutter layer is outside of the support and the following conditions are satisfied:
(i) the portion of the gutter layer outside of the support has an average thickness (GL e ) of 400 nm to 900 nm;
(ii) the portion of the gutter layer present within the support has an average thickness (GL i ) of 10% to 350% of GL e ;
(iii) x has a value of 40 to 100 nm;
(iv) the composite membrane has a dry thickness of 30 to 200 μm;
(v) Ø is <2.5;
(vi) the discriminating layer is intermixed with the gutter layer; and
(vii) the discriminating layer comprises a polyimide, cellulose acetate, polyethyleneoxide and/or polyetherimide.

14. The process according to claim 13 wherein the discriminating layer comprises a polyimide comprising trifluoromethyl groups.

15. The process according to claim 13 wherein the discriminating layer comprises a polyimide comprising groups of the Formula (2):

Assignees

• Fujifilm Mfg Europe Bv
• Fujifilm Corp

Inventors

• Dalwani Mayur
• Itoh Shigehide
• Vermeer Erik
• Meijlink Maarten
• Itami Yujiro

Classifications

• B01D69/12 Primary

  Composite membranes; Ultra-thin membranes · CPC title

• B01D53/228

  characterised by specific membranes · CPC title

• B01D71/64

  Polyimides; Polyamide-imides; Polyester-imides; Polyamide acids or similar polyimide precursors · CPC title

• B01D71/32

  containing fluorine atoms · CPC title

• B01D69/105

  Support pretreatment · CPC title