Method for manufacturing recycled pulp from used sanitary article

Patent metadata

Field	Value
Publication number	US-2017305037-A1
Application number	US-201515516260-A
Country	US
Kind code	A1
Filing date	Sep 28, 2015
Priority date	Oct 15, 2014
Publication date	Oct 26, 2017
Grant date	—

Abstract

The present invention addresses the problem of efficiently manufacturing a recycled pulp from a used sanitary article, said recycled pulp being reusable for sanitary articles and having an ash content and antibacterial properties both meeting the standards for sanitary articles. A method for manufacturing a recycled pulp reusable for sanitary articles by recovering a pulp fiber from a used sanitary article that contains the pulp fiber and a high water-absorbing polymer, said method comprising an ozone treatment step for immersing the used sanitary article or pulp fiber in an ozone-containing aqueous solution and thus disintegrating the high water-absorbing polymer contained in the used sanitary article or sticking to the pulp fiber, characterized in that the used sanitary article or pulp fiber is treated with a cationic antibacterial agent before, after or together with the ozone treatment step.

First claim

1 : A method for manufacturing recycled pulp able to be reused in sanitary articles by recovering pulp fiber from a used sanitary article containing pulp fiber and superabsorbent polymer; wherein, the method comprises an ozone treatment step for decomposing superabsorbent polymer present in the used sanitary article or adhered to the pulp fiber by immersing the used sanitary article or pulp fiber in an ozone-containing aqueous solution, and the used sanitary article or pulp fiber is treated with a cationic antibacterial agent either before, simultaneous to or after the ozone treatment step.

2 : The method according to claim 1 , comprising a decomposition step for decomposing a used sanitary article into pulp fiber and other materials by allowing physical force to act on the used sanitary article in an aqueous solution containing a polyvalent metal ion or an acidic aqueous solution having a pH of 2.5 or lower prior to the ozone treatment step.

3 : The method according to claim 1 , comprising a step for washing a used sanitary article and decomposing the used sanitary article into constituents thereof by agitating the used sanitary article in an aqueous solution containing a disinfectant or in water after the ozone treatment step.

4 : The method according to claim 2 , wherein the aqueous solution containing a polyvalent metal ion or the acidic aqueous solution having a pH of 2.5 or lower contains a cationic antibacterial agent.

5 : The method according to claim 3 , wherein the aqueous solution containing a disinfectant or the water contains a cationic antibacterial agent.

6 : The method according to claim 1 , wherein the ozone-containing aqueous solution contains a cationic antibacterial agent.

7 : The method according to claim 1 , wherein the cationic antibacterial agent is a quaternary ammonium salt.

8 : The method according to claim 1 , wherein the ozone-containing aqueous solution contains an organic acid and the pH of the ozone-containing aqueous solution is 2.5 or lower.

9 : The method according to claim 1 , wherein the concentration of ozone in the ozone-containing aqueous solution is 1 ppm by weight to 50 ppm by weight.

10 : The method according to claim 2 , wherein the polyvalent metal ion is an alkaline earth metal ion.

11 : A recycled pulp obtained according to the method according to claim 1 having an ash content of 0.65% by weight or less.

12 : The recycled pulp according to claim 11 , having an antibacterial activity value of 2.0 or more.

13 : The method according to claim 2 , wherein the ozone-containing aqueous solution contains a cationic antibacterial agent.

14 : The method according to claim 3 , wherein the ozone-containing aqueous solution contains a cationic antibacterial agent.

15 : The method according to claim 4 , wherein the ozone-containing aqueous solution contains a cationic antibacterial agent.

16 : The method according to claim 5 , wherein the ozone-containing aqueous solution contains a cationic antibacterial agent.

17 : The method according to claim 2 , wherein the cationic antibacterial agent is a quaternary ammonium salt.

18 : The method according to claim 3 , wherein the cationic antibacterial agent is a quaternary ammonium salt.

19 : The method according to claim 4 , wherein the cationic antibacterial agent is a quaternary ammonium salt.

20 : The method according to claim 5 , wherein the cationic antibacterial agent is a quaternary ammonium salt.

Assignees

• Unicharm Corp

Inventors

• Konishi Takayoshi
• Hiraoka Toshio

Classifications

• D21C5/02

  Working-up waste paper (mechanical part D21B1/08, D21B1/32) · CPC title

• D21C3/04

  with acids, acid salts or acid anhydrides {(D21C3/003 and D21C3/222 take precedence)} · CPC title

• B29B2017/0289

  Washing the materials in liquids · CPC title

• A61F13/15

  Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators · CPC title

• C08J11/16

  by treatment with inorganic material (C08J11/14 takes precedence) · CPC title