Water-proof air-permeable filter and use of the same

Patent metadata

Field	Value
Publication number	US-9636616-B2
Application number	US-201514638659-A
Country	US
Kind code	B2
Filing date	Mar 4, 2015
Priority date	Jun 16, 2010
Publication date	May 2, 2017
Grant date	May 2, 2017

Abstract

A water-proof air-permeable filter ( 1 ) includes: a resin film ( 2 ) having formed therein a plurality of through pores ( 21 ); and a treated layer ( 3 ) having hydrophobicity and oil repellency, and formed on at least one of both surfaces in the thickness direction of the resin film ( 2 ) such that the treated layer ( 3 ) has openings ( 31 ) at positions corresponding to the through pores ( 21 ). The through pores ( 21 ) each have a predetermined size larger than or equal to 0.01 μm and smaller than or equal to 10 μm, and are uniformly distributed such that a density of the through pores falls within specific limits included in a range from 10 to 1×10 8 pores/mm 2 .

First claim

The invention claimed is:

1. A water-proof air-permeable filter for ensuring ventilation and also preventing entry of water, the water-proof air-permeable filter comprising:
a non-porous resin film having opposed first and second surfaces spaced from each other in a thickness direction, the resin film having formed therein a plurality of through pores extending through the resin film in the thickness direction of the resin film; and
a treated layer having hydrophobicity and oil repellency, and formed on at least one of the first and second surfaces of the resin film such that the treated layer has openings at positions corresponding to the plurality of through pores,
wherein a ratio of a standard deviation of a size of the through pores relative to an average of the size of the through pores is 10% or less.

2. The water-proof air-permeable filter according to claim 1 ,
wherein the treated layer coats an inner surface of the through pores so as to form an inner part of the treated layer located inside the through pores.

3. The water-proof air-permeable filter according to claim 2 ,
wherein the plurality of the through pores are a plurality of straight pores.

4. The water-proof air-permeable filter according to claim 1 ,
wherein a material forming the treated layer is different from a material forming the resin film.

5. The water-proof air-permeable filter according to claim 1 ,
wherein the plurality of the through pores are a plurality of straight pores,
the treated layer coats an inner surface of the through pores so as to form an inner part of the treated layer located inside the through pores,
the inner part extends from the first surface to the second surface, and
air passages extending through the resin film are formed in the inner part.

6. A water-proof air-permeable filter for ensuring ventilation and also preventing entry of water, the water-proof air-permeable filter comprising:
a non-porous resin film having opposed first and second surfaces spaced from each other in a thickness direction, the resin film having formed therein a plurality of through pores extending through the resin film in the thickness direction of the resin film; and
a treated layer having hydrophobicity and oil repellency, and formed on at least one of the first and second surfaces of the resin film such that the treated layer has openings at positions corresponding to the plurality of through pores,
wherein a degree of variability of air permeation of the water-proof air-permeable filter is 7.7% or less, the degree of variability being obtained by measuring a degree of air permeation of the water-proof air-permeable filter at 20 spots in accordance with JIS P8117, calculating an average value of the 20 measurements and a standard deviation of the 20 measurements, dividing the standard deviation by the average value to calculate a resultant value, and multiplying the resultant value by 100 to calculate the degree of variability.

7. The water-proof air-permeable filter according to claim 6 ,
wherein the treated layer coats an inner surface of the through pores so as to form an inner part of the treated layer located inside the through pores.

8. The water-proof air-permeable filter according to claim 7 , wherein the plurality of the through pores are a plurality of straight pores.

9. The water-proof air-permeable filter according to claim 6 ,
wherein a material forming the treated layer is different from a material forming the resin film.

10. The water-proof air-permeable filter according to claim 6 ,
wherein the plurality of the through pores are a plurality of straight pores,
the treated layer coats an inner surface of the through pores so as to form an inner part of the treated layer located inside the through pores,
the inner part extends from the first surface to the second surface, and
air passages extending through the resin film are formed in the inner part.

11. A water-proof air-permeable filter for ensuring ventilation and also preventing entry of water, the water-proof air-permeable filter comprising:
a non-porous resin film having opposed first and second surfaces spaced from each other in a thickness direction, the resin film having formed therein a plurality of through pores extending through the resin film in the thickness direction of the resin film; and
a treated layer having hydrophobicity and oil repellency, and formed on at least one of the first and second surfaces of the resin film such that the treated layer has openings at positions corresponding to the plurality of through pores,
wherein an average value of a degree of air permeation of the water-proof air-permeable filter is 3.7 seconds/100 mL or less, the average value being obtained by measuring a degree of air permeation of the water-proof air-permeable filter at 20 spots in accordance with JIS P8117, and averaging the 20 measurements to calculate the average value.

12. The water-proof air-permeable filter according to claim 11 ,
wherein the treated layer coats an inner surface of the through pores so as to form an inner part of the treated layer located inside the through pores.

13. The water-proof air-permeable filter according to claim 12 , wherein the plurality of the through pores are a plurality of straight pores.

14. The water-proof air-permeable filter according to claim 11 ,
wherein a material forming the treated layer is different from a material forming the resin film.

15. The water-proof air-permeable filter according to claim 11 ,
wherein a standard deviation of the air permeation of the water-proof air-permeable filter is 0.284 sec/100 mL or less, the standard deviation of the air permeation being obtained by measuring the degree of the air permeation of the water-proof air-permeable filter at 20 spots in accordance with JIS P8117,and calculating a standard deviation of the 20 measurements to obtain the standard deviation of the air permeation.

16. The water-proof air-permeable filter according to claim 11 ,
wherein the plurality of the through pores are a plurality of straight pores,
the treated layer coats an inner surface of the through pores so as to form an inner part of the treated layer located inside the through pores,
the inner part extends from the first surface to the second surface, and
air passages extending through the resin film are formed in the inner part.

17. A method for producing a water-proof air-permeable filter, the method comprising steps of:
forming a plurality of through pores in a non-porous resin film by irradiation of ion beam and etching with an etching treatment liquid; and
applying a hydrophobic oil repellent agent onto the non-porous resin film having therein the plurality of the through pores,
wherein the plurality of the through pores are a plurality of straight pores, and
the hydrophobic oil repellent agent is applied so as to coat an inner surface of the plurality of the through pores in the step of applying the hydrophobic oil repellent agent.

18. The method for producing a water-proof air-permeable filter according to claim 17 ,
wherein the inner surface is a surface that has been subjected to the etching with the etching treatment liquid.

19. The method for producing a water-proof air-permeable filter according to claim 17 , wherein
the resin film has opposed first and second surfaces spaced from each other in a thickness direction, and
an area of the inner surface to which the hydrophobic oil repellent agent is applied extends from the first surface to the second surface s

Assignees

• Nitto Denko Corp

Inventors

• Furuyama Satoru
• Nagai Yozo
• Moriyama Junichi

Classifications

• B01D2325/04

  Characteristic thickness · CPC title

• B01D69/02

  characterised by their properties · CPC title

• H05K5/068

  having a pressure compensation device, e.g. membrane (venting means H05K5/0213) · CPC title

• B01D2279/35

  for venting arrangements · CPC title

• B32B2307/7265

  Non-permeable · CPC title