Superabsorbent coated fibers and method for their preparation

• US 4,888,238 A
• Filed: 09/16/1987
• Issued: 12/19/1989
• Est. Priority Date: 09/16/1987
• Status: Expired due to Term

• Current Assignee: BBA Nonwovens Simpsonville Inc (Signature Aviation US Topco LLC)
• Original Assignee: James River Corporation (KOCH Industries Incorporated)
• Inventors: Hollenberg, David H., Katz, Leon
• Primary Examiner(s): Lusignan, Michael
• Application Number:
  US07/097,179
• Time in Patent Office: 825 Days
• Field of Search: 427/212, 427/389.9, 427/392, 428/378, 604/371, 604/372, 604/374, 604/375
• US Class Current: 428/378
• CPC Class Codes: A61L 15/60 Liquid-swellable gel-forming materials, e.g. super-absorbents
• CPC Class Codes: D06M 11/17 Halides of elements of Groups 3 or 13 of the Periodic Table
• CPC Class Codes: D06M 11/28 Halides of elements of Groups 8, 9, 10 or 18 of the Periodic Table
• CPC Class Codes: D06M 11/76 with carbon oxides or carbonates D06M11/75 takes precedence; with percarbonic acids or their salts D06M11/50; with urea D06M13/432
• CPC Class Codes: D06M 13/188 Monocarboxylic acids; Anhydrides, halides or salts thereof D06M13/1845 takes precedence
• CPC Class Codes: D06M 15/263 of unsaturated carboxylic acids; Salts or esters thereof
• CPC Class Codes: Y10T 428/2938 Coating on discrete and individual rods, strands or filaments

Abstract

Superabsorbent synthetic fibers are prepared by a method wherein segments of synthetic fibers are coated with a solution of (a) a hydrophilic, uncomplexed polymer and (b) a complexing agent, and the coated fibers are fluff or flash dried causing the polymer to complex and to form a superabsorbent coating on the synthetic fibers in situ.

Claims

1. A method of preparing superabsorbent synthetic fibers coated with a water absorbent polymer which comprises (1) preparing an aqueous solution of an anionic polyelectrolyte and a polyvalent metal salt, said anionic polyelectrolyte being maintained water-soluble in the presence of said polyvalent metal salt by the addition of a neutralizing agent, (2) adding synthetic fibers to the polymeric solution to coat said fibers therewith, and (3) fluff drying said coated synthetic fibers to form a complex of said polyelectrolyte thereon in situ.

2. The method of claim 1 wherein said anionic polyelectrolyte is polyacrylic acid or poly (methyl vinyl ether/maleic anhydride copolymer).

3. The method of claim 1 wherein said polyvalent metal salt is selected from aluminum acetate, ammonium zirconium carbonate, chromium acetate, zirconium acetate, aluminum acetate, aluminum chloride and ferric chloride.

4. The method of claim 1 wherein said polyvalent metal salt is aluminum acetate or ammonium zirconium carbonate.

5. The method of claim 1 wherein said polyvalent metal salt is present in solution in an amount of 0.5 to 10% by weight.

6. The method of claim 1 wherein the synthetic fibers are cellulose acetate, polyester, polyolefin, polyacrylonitrile, polyamide, dacron, nylon or a bicomponent fiber.

7. The method of claim 1 wherein the polyelectrolyte solution is maintained at a pH between 7 and 9 by the addition of ammonium carbonate, ammonium hydroxide or a mixture thereof to the solution.

8. The method of claim 6 wherein the polyelectrolyte solution is maintained at a pH between 7.5 and 8.

9. The method of claim 1 wherein the fibers are dried by suspending the fibers in a stream of hot air at a temperature between 60°

and 100°

C.

10. The method of claim 7, wherein the fibers are dried in a stream of air at room temperature.

11. The method of claim 1 wherein the synthetic fibers have a denier of 0.9 to 3.

12. The method of claim 1 wherein the synthetic fibers have a length of 1/8 to 3/4 inches.

13. A coated fiber produced by the method of claim 12.

14. A coated fiber produced by the method of claim 11.

15. A coated fiber produced by the method of claim 10.

16. A coated fiber produced by the method of claim 9.

17. A coated fiber produced by the method of claim 8.

18. A coated fiber produced by the method of claim 7.

19. A coated fiber produced by the method of claim 6.

20. A coated fiber produced by the method of claim 5.

21. A coated fiber produced by the method of claim 4.

22. A coated fiber produced by the method of claim 3.

23. A coated fiber produced by the method of claim 2.

24. A superabsorbent material consisting of a synthetic fiber coated with a substantially dry water-absorbent polymer which comprises a hydrophilic polymer crosslinked with a polyvalent metal salt.

25. A superabsorbent material according to claim 24 wherein the synthetic fiber is cellulose acetate, polyester, polyolefin, polyacrylonitrile, polyamide, dacron, nylon, rayon, or a bicomponent fiber.

26. A superabsorbent material according to claim 24 wherein the hydrophilic polymer is an anionic polyelectrolyte selected from polyacrylic acid and poly (methyl vinyl ether/maleic anhydride copolymer) and is crosslinked in situ with a polyvalent metal salt selected from aluminum acetate, ammonium zirconium carbonate, chromium acetate, zirconium acetate, aluminum acetate, aluminum chloride and ferric chloride.