Water-absorbent sheet structure

Patent metadata

Field	Value
Publication number	US-9233519-B2
Application number	US-201013521376-A
Country	US
Kind code	B2
Filing date	Dec 27, 2010
Priority date	Jan 13, 2010
Publication date	Jan 12, 2016
Grant date	Jan 12, 2016

Abstract

A water-absorbent sheet structure comprises a structure in which an absorbent layer containing a water-absorbent resin (A) and a water-absorbent resin (B) is sandwiched with fibrous webs from an upper side and a lower side of the absorbent layer, characterized in that the water-absorbent resin (A) and the water-absorbent resin (B) are contained in a total amount of from 100 to 1,000 g/m 2 , and that the water-absorbent resin (A) and the water-absorbent resin (B) have the following properties: (1) the water-absorbent resin (A) having a water-retention capacity of saline solution (Ra) from 15 to 55 g/g; (2) the water-absorbent resin (B) having a water-retention capacity of saline solution (Rb) from 10 to 50 g/g; and (3) Ra and Rb mentioned above satisfies the relationship of the following formula: Ra−Rb≧(g/g). The water-absorbent sheet structure of the present invention exhibits some effects that a water-absorbent sheet structure has excellent shape retaining ability even when the structure is thin, so that the water-absorbent sheet structure does not undergo deformation of the form before liquid absorption or after the absorption, and is capable of sufficiently exhibiting absorbent properties.

First claim

The invention claimed is:

1. A water-absorbent sheet structure comprising a structure in which an absorbent layer comprising a water-absorbent resin composition comprising a water-absorbent resin (A) and a water-absorbent resin (B) is sandwiched with fibrous webs from an upper side and a lower side of the absorbent layer, wherein the water-absorbent resin (A) and the water-absorbent resin (B) are contained in a total amount of from 100 to 1,000 g/m 2 , and that the water-absorbent resin (A) and the water-absorbent resin (B) have the following properties:
(1) the water-absorbent resin (A) having a water-retention capacity of saline solution (Ra) from 25 to 55 g/g;
(2) the water-absorbent resin (B) having a water-retention capacity of saline solution (Rb) from 20 to 24 g/g; and
(3) Ra and Rb satisfy the relationship: Ra−Rb≧5 (g/g)
wherein the water-absorbent resin (A) and the water-absorbent resin (B) are in a mass ratio, the water-absorbent resin (A): the water-absorbent resin (B), of from 90:10 to 80:20.

2. The water-absorbent sheet structure of claim 1 , wherein the water-absorbent resin (B) has a water-absorption capacity of saline solution under load of 4.14 kPa of 15 mL/g or more.

3. The water-absorbent sheet structure of claim 1 , wherein the fibrous webs are nonwoven fabrics comprising at least one fiber selected from the group consisting of rayon fibers, polyolefin fibers, and polyester fibers.

4. The water-absorbent sheet structure of claim 1 , wherein the water-absorbent sheet structure satisfies properties (4) to (6):
(4) a thickness of 5 mm or less, in a dry state;
(5) a total permeation rate of 120 seconds or less; and
(6) a leakage index of 150 or less.

5. An absorbent article, comprising:
the water-absorbent sheet structure of claim 1 , sandwiched between a liquid-permeable sheet and a liquid-impermeable sheet.

6. The water-absorbent sheet of claim 1 , wherein the water-absorbent resin (A) and the water-absorbent resin (B) are contained in a total amount of from 150 to 800 g/m 2 .

7. The water-absorbent sheet of claim 1 , wherein the water-absorbent resin (A) and the water-absorbent resin (B) are contained in a total amount of from 200 to 700 g/m 2 .

8. The water-absorbent sheet of claim 1 , wherein the water-absorbent resin (A) and the water-absorbent resin (B) are contained in a total amount of from 220 to 600 g/m 2 .

9. The water-absorbent sheet of claim 1 , wherein the water-absorbent resin (A) has a water-retention capacity of saline solution (Ra) of from 20 to 55 g/g.

10. The water-absorbent sheet of claim 1 , wherein the water-absorbent resin (A) has a water-retention capacity of saline solution (Ra) of from 25 to 55 g/g.

11. The water-absorbent sheet of claim 1 , wherein the water-absorbent resin (A) has a water-retention capacity of saline solution (Ra) of from 30 to 50 g/g.

12. The water-absorbent sheet structure of claim 1 , wherein the water-absorbent resin (B) has a water-absorption capacity of saline solution under load of 4.14 kPa of from 20 to 40 ml/g.

13. The water-absorbent sheet structure of claim 1 , said the water-absorbent resin composition consists of a water-absorbent resin (A), a water-absorbent resin (B) and an adhesive.

Assignees

• Yamaguchi Kiyoshi
• Tsuno Syuji
• Inaba Haruka
• Handa Masayoshi
• Sumitomo Seika Chemicals

Inventors

• Yamaguchi Kiyoshi
• Tsuno Syuji
• Inaba Haruka
• Handa Masayoshi

Classifications

• A61F2013/15463

  Absorbency · CPC title

• A61F2013/530737

  by the absorbent capacity · CPC title

• B32B2262/0276

  Polyester fibres · CPC title

• A61F2013/530554

  and being fixed to a web · CPC title

• B32B2262/04

  Cellulosic plastic fibres, e.g. rayon · CPC title