ALKALINE BATTERY SEPARATOR AND ALKALINE PRIMARY BATTERY

• US 20090017385A1
• Filed: 02/23/2006
• Published: 01/15/2009
• Est. Priority Date: 02/25/2005
• Status: Active Grant

• Current Assignee: Kuraray Company Limited
• Original Assignee: Kuraray Company Limited
• Inventors: Kawai, Hiroyuki, Harada, Toshimitsu, Nishiyama, Masakazu, Nagi, Hisashi
• Granted Patent: US 8,097,366 B2
• Time in Patent Office: Days
• US Class Current: 429/255
• CPC Class Codes: H01M 50/4295 Natural cotton, cellulose or wood
• CPC Class Codes: H01M 50/44 Fibrous material
• CPC Class Codes: H01M 50/446 Composite material consisting of a mixture of organic and inorganic materials
• CPC Class Codes: H01M 50/494 Tensile strength
• CPC Class Codes: H01M 6/06 Dry cells, i.e. cells wherein the electrolyte is rendered non-fluid

Abstract

An alkaline battery separator comprising an alkali-resistance synthetic fiber, a fibrillated organic solvent-spun cellulose fiber having a Canadian standard freeness value of 10 to 280 ml, and a mercerized pulp having a Canadian standard freeness value of not less than 550 ml is prepared. In the separator, the proportion of the alkali-resistance synthetic fiber, the proportion of the fibrillated organic solvent-spun cellulose fiber, and the proportion of the mercerized pulp relative to the total amount of the separator are respectively 25 to 62% by mass, 5 to 25% by mass, and 33 to 50% by mass, provided that the total amount of the separator is 100% by mass. The alkali-resistance synthetic fiber may comprise a polyvinyl alcohol-series fiber having an average fiber fineness of not more than 1 dtex. The alkaline battery separator may further comprise a polyvinyl alcohol-series binder in a proportion of 3 to 20% by mass relative to the total amount of the separator. The alkaline battery separator of the present invention may have a shrinkage by the area of not more than 3.5% after immersing in an aqueous solution of potassium hydroxide having a concentration of 40% by mass at 80° C. for 24 hours and a stiffness strength of not less than 2 N.

Claims

1. An alkaline battery separator comprising an alkali-resistance synthetic fiber, a fibrillated organic solvent-spun cellulose fiber having a Canadian standard freeness value of 10 to 280 ml, and a mercerized pulp having a Canadian standard freeness value of not less than 550 ml, wherein the proportion of the alkali-resistance synthetic fiber, the proportion of the fibrillated organic solvent-spun cellulose fiber, and the proportion of the mercerized pulp relative to the total amount of the separator are respectively 25 to 62% by mass, 5 to 25% by mass, and 33 to 50% by mass,

provided that the total amount of the separator is 100% by mass.

2. An alkaline battery separator according to claim 1, wherein the alkali-resistance synthetic fiber comprises a polyvinyl alcohol-series fiber having an average fiber fineness of not more than 1 dtex.

3. An alkaline battery separator according to claim 1, wherein the mercerized pulp comprises a mercerized product of at least one pulp selected from the group consisting of a hardwood pulp, a softwood pulp, a eucalyptus pulp, a Manila hemp pulp, a sisal fiber pulp, and a cotton linter pulp.

4. An alkaline battery separator according to claim 1, which further comprises a polyvinyl alcohol-series binder in a proportion of 3 to 20% by mass relative to the total amount of the separator.

5. An alkaline battery separator according to claim 1, which comprises a wet-laid nonwoven fabric.

6. An alkaline battery separator according to claim 1, which has a shrinkage by the area of not more than 3.5% after immersing in an aqueous solution of potassium hydroxide having a concentration of 40% by mass at 80°

C. for 24 hours and a stiffness strength of not less than 2 N.

7. An alkaline primary battery comprising a separator recited in claim 1.