Alkaline battery separator and method for producing same

Patent metadata

Field	Value
Publication number	US-11936067-B2
Application number	US-201917418542-A
Country	US
Kind code	B2
Filing date	Dec 13, 2019
Priority date	Dec 26, 2018
Publication date	Mar 19, 2024
Grant date	Mar 19, 2024

Abstract

An alkaline battery separator containing an alkali resistant fiber and a binder, wherein the alkaline battery separator has two surfaces which are a surface A that is smoother comparing with the other surface and has an arithmetic mean surface roughness Ra (A), and a surface B that is rougher and has an arithmetic mean surface roughness Ra (B), the amount of the binder is 5 to 20% by mass based on the total mass of the separator, a value obtained by dividing the arithmetic mean surface roughness Ra (A) by the arithmetic mean surface roughness Ra (B) [Ra (A)/Ra (B)] is 0.700 or more and 0.980 or less, and the arithmetic mean surface roughness Ra (B) of the surface B is 3.0 μm or more and 10 μm or less.

First claim

The invention claimed is:

1. An alkaline battery separator, comprising:
an alkali resistant fiber and
a binder,
wherein the alkaline battery separator has two surfaces: a surface A and a surface B,
the surface A is smoother comparing with the surface B and has an arithmetic mean surface roughness Ra (A),
the surface B is rougher and has an arithmetic mean surface roughness Ra (B),
the alkaline battery separator comprises the binder in an amount of from 5 to 20% by mass based on a total mass of the alkaline battery separator,
a value obtained by dividing the arithmetic mean surface roughness Ra (A) by the arithmetic mean surface roughness Ra (B) [Ra (A)/Ra (B)] is from 0.700 to 0.980, and
the arithmetic mean surface roughness Ra (B) of the surface B is from 3.0 μm to 10 μm.

2. The alkaline battery separator according to claim 1 , wherein the binder is a polyvinyl alcohol-based binder.

3. The alkaline battery separator according to claim 1 , wherein at least a part of the alkali resistant fiber is a polyvinyl alcohol-based fiber.

4. The alkaline battery separator according to claim 1 , wherein at least a part of the alkali resistant fiber is a cellulose fiber.

5. The alkaline battery separator according to claim 1 , having an air permeability of 50 cc/cm2/sec or less.

6. The alkaline battery separator according to claim 1 , having a tensile strength in a vertical direction of 2 kg/15 mm or more.

7. A method of producing the alkaline battery separator according to claim 1 , the method comprising:
obtaining wet paper by a wet papermaking method; and
drying the wet paper using a contact dryer,
wherein the drying comprises applying a pressure, in a thickness direction, to the wet paper having a water content of from 65 to 75% by mass.

8. An alkaline battery, comprising the alkaline battery separator according to claim 1 .

Assignees

• Kuraray Co

Inventors

• Hayakawa Tomohiro
• Mitsumori Haruna
• Kusunoki Toshimichi
• Kawai Hiroyuki

Classifications

• H01M50/446 Primary

  Composite material consisting of a mixture of organic and inorganic materials · CPC title

• H01M50/406

  Moulding; Embossing; Cutting · CPC title

• H01M50/409

  Separators, membranes or diaphragms characterised by the material · CPC title

• H01M50/414 Primary

  Synthetic resins, e.g. thermoplastics or thermosetting resins · CPC title

• H01M50/44

  Fibrous material · CPC title