Indicator on body fluid absorbent article

• US 20040138633A1
• Filed: 12/24/2003
• Published: 07/15/2004
• Est. Priority Date: 12/27/2002
• Status: Active Grant

• Current Assignee: Unicharm Corporation
• Original Assignee: Unicharm Corporation
• Inventors: Nakajima, Kaiyo, Mishima, Yoshitaka, Takai, Hisashi
• Granted Patent: US 7,154,019 B2
• Time in Patent Office: Days
• US Class Current: 604/361
• CPC Class Codes: A61F 13/42 with wetness indicator or alarm

Abstract

An indicator interposed between a liquid-impervious sheet and an absorbent core of a body fluid absorbent article includes a water-absorbent sheet and indication elements held in close contact with the water-absorbent sheet. The water-absorbent sheet is preferably formed from porous thermoplastic films having a total luminous transmittance of 40% or lower in a dry state and 60% or higher in a wet state.

Claims

1. In a body fluid absorbent article comprising:

a liquid-pervious sheet;

a liquid-impervious sheet;

a body fluid absorbent core interposed therebetween;

an indicator interposed between said liquid-impervious sheet and said core and comprising a water-absorbent sheet which allows said core in a wet state to be visually perceived from outside said liquid-impervious sheet and indication elements temporarily concealed by said water-absorbent sheet;

said water-absorbent sheet comprising a porous thermoplastic film having an inner surface facing said core and an outer surface facing said liquid-impervious sheet;

said film having a total luminous transmittance of 40% or lower in a dry state and 60% or higher in a wet state; and

said indication elements being held in close contact with said inner surface.

2. The indicator according to claim 1, wherein said thermoplastic film exhibits a Klemm'"'"'s water-absorbency in a range of 1 to 10 mm.

3. The indicator according to claim 1, wherein said thermoplastic film contains 20 to 80 wt % of inorganic particles each having a particle diameter in a range of 0.1 to 10μ

.

4. The indicator according to claim 1, wherein said thermoplastic film contains 0.5 to 5 wt % of modifier for hydrophilicity.

5. The indicator according to claim 4, wherein said inorganic particles are coated with at least a part of said modifier for hydrophilicity.

6. The indicator according to claim 1, wherein said thermoplastic film is obtained by extruding thermoplastic containing said inorganic particles to form a starting film and then monoaxially or biaxially stretching said starting film at a ratio of 100 to 300%.

7. The indicator according to claim 1, wherein said indication elements comprise layers of print ink or other coating materials intermittently formed on an inner surface of said water-absorbent sheet.

8. The indicator according to claim 1, wherein said indication elements is defined by said core itself.

9. The indicator according to claim 1, wherein said thermoplastic film has a water-absorption in a range of 5 to 100 wt %.