Water-absorbing composite body

• US 4,966,809 A
• Filed: 12/02/1987
• Issued: 10/30/1990
• Est. Priority Date: 04/02/1986
• Status: Expired due to Fees

• Current Assignee: Showa Denko KK (Resonac Holdings Corp.)
• Original Assignee: Showa Denko KK (Resonac Holdings Corp.)
• Inventors: Nakamura, Akira, Tanaka, Toyoaki, Hashimoto, Akihiro, Kamei, Ryosuke, Ohira, Katuzi
• Primary Examiner(s): SLUBY, PATRICIA
• Application Number:
  US07/155,935
• Time in Patent Office: 1,063 Days
• Field of Search: 428/375, 428/323, 428/372, 428/374, 428/377, 428/395, 428/394, 428/400, 428/401, 428/913
• US Class Current: 428/323
• CPC Class Codes: A61F 13/53 characterised by the absorbing medium A61F13/20 takes precedence
• CPC Class Codes: A61F 13/534 having an inhomogeneous composition through the thickness of the pad A61F13/538, A61F13/539 take precedence; homogeneous cores with tissue wrapping A61F13/53
• CPC Class Codes: A61F 13/539 characterised by the connection of the absorbent layers with each other or with the outer layers
• CPC Class Codes: A61F 2013/530481 having superabsorbent materials, i.e. highly absorbent polymer gel materials
• CPC Class Codes: A61F 2013/53051 being only in particular parts or specially arranged
• CPC Class Codes: A61F 2013/53445 from several sheets
• CPC Class Codes: B32B 27/08 of synthetic resin
• CPC Class Codes: B32B 27/304 comprising vinyl halide (co)polymers, e.g. PVC, PVDC, PVF, PVDF
• CPC Class Codes: B32B 7/027 Thermal properties
• CPC Class Codes: G02B 6/44384 the means comprising water blocking or hydrophobic materials G02B6/4439, G02B6/4479 take precedence
• CPC Class Codes: Y10S 428/913 Material designed to be responsive to temperature, light, moisture
• CPC Class Codes: Y10T 156/1087 Continuous longitudinal slitting
• CPC Class Codes: Y10T 428/25 Web or sheet containing structurally defined element or component and including a second component containing structurally defined particles
• CPC Class Codes: Y10T 428/2927 including structurally defined particulate matter
• CPC Class Codes: Y10T 428/2931 Fibers or filaments nonconcentric [e.g., side-by-side or eccentric, etc.]
• CPC Class Codes: Y10T 428/2933 Coated or with bond, impregnation or core
• CPC Class Codes: Y10T 428/2936 Wound or wrapped core or coating [i.e., spiral or helical]
• CPC Class Codes: Y10T 428/2967 Synthetic resin or polymer
• CPC Class Codes: Y10T 428/2969 Polyamide, polyimide or polyester
• CPC Class Codes: Y10T 428/2978 Surface characteristic
• CPC Class Codes: Y10T 428/298 : Physical dimension

Abstract

Disclosed is a water-absorbing composite body comprising a tape-shaped laminate having at least one layer of a high-melting-point synthetic resin and at least one layer of a low-melting-point synthetic resin, in which at least a part of the low-melting-point synthetic resin layer is exposed to the surface, a split fiber obtained by splitting this tape-shaped laminate or a composite fibrous body having a laminate structure as described above, and a powdery polymeric water absorber fusion-bonded to the outer surface of the low-melting-point synthetic resin layer exposed to the surface. This water-absorbing composite body has a high water-absorbing capacity and retains a good mechanical strength.

Claims

1. A water-absorbing composite body comprising (A) a split yarn obtained by splitting a tape-shaped three-layer laminate composed of a low-melting point synthetic resin layer, a high-melting point synthetic resin layer, and a low-melting point synthetic resin layer, wherein the two low-melting point synthetic resin layers are exposed on the surface of the laminate, and B) a powdery polymeric water-absorber fusion-bonded to the exposed surface of each low-melting point synthetic resin layer.

2. A water-absorbing composite body as set forth in claim 1, wherein the high-melting-point synthetic resin is selected from the group consisting of isotactic polypropylene, high-density polyethylene, a polyester, nylon 6, and nylon 66.

3. A water-absorbing composite body as set forth in claim 1, wherein the low-melting-point synthetic resin is selected from the group consisting of low-density polyethylene, linear low-density polyethylene, high-density polyethylene, an ethylene/vinyl acetate copolymer, a polyolefin graft-modified with an unsaturated carboxylic acid or an anhydride thereof, an ethylene/maleic anhydride/methyl methacrylate terpolymer, an ethylene/acrylic acid copolymer, an ethylene/ethyl acrylate copolymer and an ionomer resin.

4. A water-absorbing composite body as set forth in claim 1, wherein the difference of the melting point between the high-melting-point synthetic resin and the low-melting-point synthetic resin is at least 10°

C.

5. A water-absorbing composite body as set forth in claim 1, wherein the split yarn has a thickness of 500 to 10,000 denier.

6. A water-absorbing composite body as set forth in claim 1, wherein the split yarn has a split width of 0.03 to 0.2 mm.

7. A water-absorbing composite body as set forth in claim 1, wherein the powdery polymeric water absorber has a water absorption ratio of 500 to 1,000.

8. A water-absorbing composite body as set forth in claim 1, wherein the powdery polymeric water absorber is selected from the group consisting of crosslinked poly(sodium acrylate), a saponified acrylic acid/vinyl acetate copolymer, a starch/acrylic acid graft copolymer and an isobutylene/maleic anhydride copolymer.

9. A water-absorbing composite body as set forth in claim 1, wherein the average particle size of the powdery polymeric water absorber is 10 to 500 μ

m.

10. A water-absorbing composite body as set forth in claim 1, wherein the average particle size of the powdery polymeric water absorber is 10 to 300 μ

m.

11. A water-absorbing composite body as set forth in claim 1, wherein the average particle size of the powdery polymeric water absorber is 10 to 50 μ

m.

12. A water-absorbing composite body as set forth in claim 1, wherein the average particle size of the powdery polymeric water absorber is 10 to 30 μ

m.

13. A water-absorbing composite body as set foerth in claim 1, wherein the amount of the fusion-bonded powdery polymeric water absorber is 10 to 60% by weight based on the split yarn before the fusion bonding.

14. A water-absorbing composite body as set forth in claim 1, wherein the split yarn, to which the powdery polymeric water absorber is fusion-bonded, is wound and enclosed with a tape of a water-soluble resin.

15. A water-absorbing composite body as set forth in claim 14, wherein the water-soluble resin is polyvinyl alcohol.