Fluid repellent microporous materials

• US 6,858,290 B2
• Filed: 05/29/2002
• Issued: 02/22/2005
• Est. Priority Date: 05/29/2002
• Status: Expired due to Term

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Jariwala, Chetan P., Mrozinski, James S.
• Primary Examiner(s): Morris, Terrel
• Assistant Examiner(s): CHANG, VICTOR S
• Application Number:
  US10/159,752
• Publication Number:
  US 20030228459A1
• Time in Patent Office: 1,000 Days
• Field of Search: 428/315.5, 428/304.4, 428/315.9, 428/221, 428/357, 428/364, 428/365, 428/395, 424/402, 524/95, 524/425, 524/451, 524/445, 524/449, 525/165, 525/178, 525/199, 525/200
• US Class Current: 428/304.4
• CPC Class Codes: B29C 55/005 characterised by the choice of materials
• CPC Class Codes: B29K 2105/04 cellular or porous
• CPC Class Codes: B29K 2105/16 Fillers
• CPC Class Codes: B32B 5/18 characterised by features of a layer of foamed material
• CPC Class Codes: Y10T 428/249921 Web or sheet containing structurally defined element or component
• CPC Class Codes: Y10T 428/249953 Composite having voids in a component [e.g., porous, cellular, etc.]
• CPC Class Codes: Y10T 428/249978 Voids specified as micro
• CPC Class Codes: Y10T 428/24998 Composite has more than two layers
• CPC Class Codes: Y10T 428/29 Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
• CPC Class Codes: Y10T 428/2913 Rod, strand, filament or fiber
• CPC Class Codes: Y10T 428/2915 including textile, cloth or fabric
• CPC Class Codes: Y10T 428/2969 Polyamide, polyimide or polyester

Abstract

Microporous articles formed by thermally induced phase separation from a diluent in combination with a thermoplastic polymer and a fluorochemical additive providing novel fluid repellent articles. Such articles are useful in clothing, barrier membranes, optical films in electronic devices (such as light reflective and dispersive films), and protective garments.

Claims

1. A microporous article comprising:

(a) a crystallizable olefin polymer component; and

(b) a fluorochemical additive, which is the reaction product of one or more polyfunctional compounds having reactive hydroxy and/or acyl functional groups, and having from 3 to 12 carbon atoms;

with one or more monofunctional fluorochemical compounds of the formula

R_fQZ;

wherein R_f is a fluoroalkyl group having 3 to 12 carbon atoms,

Q is a divalent linking group, and

Z is a co-reactive hydroxyl group or acyl group that reacts with the corresponding reactive group of said polyfunctional compound; and

one or more aliphatic monofunctional compounds of the formula

R_hZ,

wherein R_h is an aliphatic group having from 12 to 72 carbon atoms, and

Z is a co-reactive hydroxyl group or acyl group that reacts with the corresponding reactive group of said polyfunctional compound.

2. The microporous article of claim 1 further comprising a diluent component, said diluent component being miscible with the polymer component at a temperature above the liquid-solid phase separation temperature and able to phase separate from the polymer component through crystallization separation upon cooling below the liquid-solid phase separation temperature.

3. The microporous article of claim 2 comprising:

(a) about 40 to 80 parts by weight of said crystallizable olefin polymer component;

(b) about 20 to 60 parts by weight of said diluent component,; and

(c) at least about 0.5 parts by weight of said fluorochemical additive.

4. The microporous article of claim 1, wherein the amount of said monofunctional fluorochemical compound R_fQZ is sufficient to react with at least 25% of the available reaction functional groups of said polyfunctional compound and the amount of said aliphatic monofunctional compound R_hZ is sufficient to react with at least 25% of the available reaction functional groups of said polyfunctional compound.

5. The microporous article of claim 1, wherein said fluorochemical additive is of the formula:

[R_h(CO₂)]_m—

A—

[(CO₂)—

QR_f]_n

wherein A is the residue of a polyol or polyacid optionally having one or more unreacted hydroxyl or carboxyl functional groups,

R_h is an alkyl group of 12 to 72 carbon atoms,

R_f a fluoroalkyl group having 3 to 12 carbon atoms,

Q is a divalent linking group,

each (CO₂) group is non-directional, and

m and n are each at least 1.

6. The microporous article of claim 1 wherein said fluorochemical additive is of the formula:

wherein A′

is the residue of a polyol, optionally having one or more unreacted hydroxyl or carboxyl functional groups,

R_h is an alkyl group of 12 to 72 carbon atoms,

R_f is a fluoroalkyl group of 3 to 12 carbon atoms,

Q′

is a divalent linking group, and

m and n are each at least 1.

7. The microporous article of claim 1 wherein said fluorochemical additive is of the formula:

wherein A″

is the residue of a polyacid optionally having one or more unreacted hydroxyl or carboxyl functional groups,

R_h is an alkyl group of 12 to 72 carbon atoms,

R_f is a fluoroalkyl group having 3 to 12 carbon atoms,

Q″

is a divalent linking group, and

m and n are each at least 1.

8. The microporous article of claim 7 wherein m is 1 to 2, n is 1 to 2 and m+n is about 3.

9. The fluorochemical additive of claim 5, R_f has 3 to 6 carbon atoms, n is at least 1.5, m+n is 3 and Q is —

SO₂NR₁′

(CH₂)_k—

, wherein k is from 2 to 11, and R₁′

is hydrogen, or alkyl of 1 to about 4 carbon atoms.

10. A multilayer microporous film comprising at least one layer of a microporous material according to claim 1.

11. The multilayer film of claim 10 further comprising at least one additional layer selected from the group consisting of non-woven fabric, woven fabric, porous film, and non-porous film.

12. The article of claim 1 wherein the polymer component is a polyolefin, a polyolefin copolymers, a polyolefin blend or a mixture thereof.

13. The article of claim 12, wherein the polyolefin is polypropylene, high density polyethylene, or copolymers of propylene and ethylene.

14. The article of claim 1 wherein said microporous membrane has a moisture vapor transmission rate of at least 2000 g/m²/24 hours when measured at 40°

C. and 50% relative humidity.

15. The article of claim 1 wherein the fluorochemical additive comprises about 1 to 10 weight percent of the article.

16. The article of claim 1 wherein the fluorochemical additive comprises about 1 to 5 weight percent of the article.

17. The article of claim 1 further comprising said microporous membrane material being layered with at least one porous material which does not generally affect prevention of viral pathogen transmission.

18. The article of claim 1 further comprising said microporous membrane material being layered with at least one porous material which does not generally affect the porosity of said microporous membrane.

19. The article of claim 2 wherein said diluent is selected from the group consisting of alkyl phthalate, mineral oil;

mineral spirits;

petroleum jelly, waxes and mixtures and blends thereof.

20. The article of claim 1 comprising a first phase of polymer spherulites inconnected with polymer fibrils creating a network of interconnected micropores, and a second phase comprising the diluent component and fluorochemical additive at least partially coating said spherulites and fibrils.

21. The microporous article of claim 2 wherein said polymer and said diluent are selected from the group consisting of polypropylene with mineral oil, dioctyl phthalate, petroleum jelly, wax or mineral spirits;

polypropylene-polyethylene copolymer with mineral oil;

polyethylene with mineral oil or mineral spirits and mixtures and blends thereof.

22. The microporous article of claim 1 further comprising an inorganic filler.

23. The microporous article of claim 22 wherein said inorganic filler is selected from the group consisting of alkali- or alkaline earth metal carbonates and sulfates.

24. The microporous article of claim 3 comprising 35 to 60 parts by weight of diluent component.

25. The microporous article of claim 3 comprising 65 to 80 parts by weight of polymer component.

26. The microporous article of claim 3 comprising 1 to 10 parts by weight of fluorochemical additive.

27. The microporous article of claim 3 comprising at least 15 weight percent fluorine.

28. A protective garment comprising the microporous article of claim 1.

29. A barrier membrane comprising the microporous article of claim 1.

30. The microporous article of claim 3, further comprising 0.05 to 5 parts by weight of a nucleating agent.

31. The microporous article of claim 1, wherein said polyfunctional compound is citric acid or derivative thereof.