Separator material for forming a separator for a lead-acid accumulator

Patent metadata

Field	Value
Publication number	US-9577234-B2
Application number	US-56054804-A
Country	US
Kind code	B2
Filing date	Jun 11, 2004
Priority date	Jun 13, 2003
Publication date	Feb 21, 2017
Grant date	Feb 21, 2017

Abstract

The invention relates to a separator material ( 6 ) for forming a separator for a lead-acid accumulator, especially in the form of unfinished rolled product, and a method for the production thereof. The inventive separator material ( 6 ) comprises a first layer in the form of a microporous film ( 1 ) and at least one second layer in the form of a planar fleece material ( 7 ). At least one face of the microporous film ( 1 ), which is made of a thermoplastic material, is provided with a number of protrusions ( 2, 2 ′) defining an area with an increased film thickness on a basic film sheet. The fleece material ( 7 ) is welded to the film ( 1 ) by means of ultrasonic welding in such a way that the planar fleece material ( 7 ) is located at least at the level of the surface of the basic film sheet without invading the same in the area of the welded joints ( 8 ).

First claim

The invention claimed is:

1. Separator material for forming a separator for a lead-acid accumulator, wherein the separator material comprises a first layer in the form of a microporous film, and at least one second layer in the form of a planar fleece material, wherein said first layer is made of a thermoplastic polyolefin and has a film base sheet and a number of central ribs having an initial height prior to being welded to said planar fleece material, each rib defining an area of increased film thickness, on at least one face of the film base sheet, said at least one second layer in the form of a planar fleece material being located on a face of said film having said central ribs, wherein said fleece material has a thickness of 0.25 mm or less and comprises glass fibers, polyester fibers or a mixture of glass fibers and polyester fibers and wherein the at least one planar fleece material is bonded to said film by a number of welded joints such that the planar fleece material is located at the level of the surface of the film base sheet in the area of the welded joints and does not penetrate into the film base sheet, said planar fleece material being bonded to at least some of said central ribs of said film by the welded joints, wherein the height of the at least some of the central ribs forming said welded joints is decreased relative to said initial height.

2. Separator material according to claim 1 , wherein the central ribs run vertically.

3. Separator material according to claim 2 , further comprising a plurality of side edge ribs on each side edge area of said film, said side edge ribs being more densely spaced compared to said central ribs, and wherein there is an outermost central rib closest to each innermost side edge rib on each side edge area of said film, said outermost central rib having an initial height prior to being welded to said planar fleece material, and each said outermost central rib is welded to said planar fleece material by welded joints that comprise weld seams which run on each said outermost central rib and wherein the height of each said outermost central rib is decreased relative to said initial height.

4. Separator material according to claim 3 , wherein the outermost central ribs are continuous ribs and said welded joints are continuous weld seams.

5. Separator material according to claim 3 , wherein the outermost central ribs are discontinuous ribs and said welded joints are discontinuous weld seams.

6. Separator material according to claim 1 , wherein the welded joints are spot-welded joints.

7. Separator material according to claim 1 , wherein the polyolefin has a molecular weight of at least 300,000.

8. Separator material according to claim 7 , wherein the polyolefin is polyethylene.

9. Separator material according to claim 8 , wherein the microporous film is produced from polyethylene having a filler content of silica.

10. Separator material according to claim 1 , wherein at least 50% of the pores of the microporous film have a diameter of 0.5 μm or less.

11. Separator material according to claim 1 , wherein the microporous film has a thickness of from 0.1 to 0.6 mm in areas without central ribs.

12. Separator material according to claim 1 , wherein the fleece material substantially consists of polyester fibers.

13. Separator material according to claim 1 , wherein the fleece material comprises a mixture of glass fibers and polyester fibers.

14. Separator material according to claim 13 , wherein the content of glass fibers in the mixture is not more than 70 wt. %.

15. Separator material according to claim 1 , wherein the fleece material has a thickness of from 0.1 to 0.25 mm.

16. Process for the production of a separator material for forming a separator for a lead-acid accumulator, according to claim 1 , with the steps: (a) provision of a microporous film, which is made of a thermoplastic polyolefin and has a film base sheet and a number of elevated height central ribs, each rib defining an area of increased film thickness, on at least one face of the film base sheet, (b) provision of at least one planar fleece material, (c) location of the at least one planar fleece material on a face of the film having said central ribs and (d) welding of the at least one planar fleece material with at least some of the central ribs of the film, such that the planar fleece material is located at the level of the surface of the film base sheet in the area of the welded joints and does not penetrate into the film base sheet.

17. Process according to claim 16 , wherein the welding takes place by means of ultrasonic welding.

18. Process according to claim 16 or claim 17 , wherein at least some of the central ribs of the microporous film have a height of from 0.5 to 0.6 mm and the welding takes place with these central ribs.

19. Process according to one of claims 16 or 17 , wherein said planar fleece material has a thickness of from 0.1 to 0.25 mm.

20. Process according to claim 16 , wherein the step of welding of the at least one planar fleece material with at least some of the central ribs of the film causes at least some of the central ribs to disappear completely during the welding process.

21. Process according to claim 16 , wherein the step of locating the at least one planar fleece material on a face of the film having central ribs comprises gradually laying one of said at least one planar fleece material and said film having central ribs on the other in sections.

22. Process according to claim 16 , wherein the step of locating the at least one planar fleece material on a face of the film having central ribs comprises gradually laying one of said at least one planar fleece material and said film having central ribs on the other continuously.

23. Separator material according to claim 1 , wherein said film has edge areas, and wherein said edge areas of said film are not covered with said planar fleece material.

24. Separator material according to claim 23 , wherein the width of said edge areas is between 5.5 and 9.5 mm.

25. Separator material according to claim 1 , wherein said welded joints are ultrasonic welded joints.

26. Separator material for forming a separator for a lead-acid accumulator, wherein the separator material comprises a first layer in the form of a microporous film, and at least one second layer in the form of a planar fleece material, wherein said first layer is made of a thermoplastic polyolefin and has a film base sheet and a number of central ribs having an initial height prior to being welded to said planar fleece material, each rib defining an area of increased film thickness, on at least one face of the film base sheet, said at least one second layer in the form of a planar fleece material being located on a face of said film having said central ribs, wherein said fleece material has a thickness of 0.25 mm or less and is narrower than said microporous film so as to create edge areas where the microporous film is not covered, and comprises glass fibers, polyester fibers or a mixture of glass fibers and polyester fibers and wherein the at least one planar fleece material is bonded to said film by a number of welded joints such that the height of the central ribs forming said welded joints is decreased relative to said initial height, and such that the planar fleece material is located at the level of the surface of the film base sheet in the area of the welded joints a

Assignees

• Dreyer Daniel
• Caublot Jean-Martial
• Daramic Llc

Inventors

• Dreyer Daniel
• Caublot Jean-Martial

Classifications

• H01M10/06 Primary

  Lead-acid accumulators (semi-lead accumulators H01M10/20) · CPC title

• H01M50/451

  comprising layers of only organic material and layers containing inorganic material · CPC title

• H01M50/454

  comprising a non-fibrous layer and a fibrous layer superimposed on one another · CPC title

• H01M50/417

  Polyolefins · CPC title

• H01M50/434

  Ceramics · CPC title