Method for producing water-disintegrable paper

Abstract

To provide a method of producing water-disintegrable paper capable of addressing a disadvantage of adhesion of a base-paper sheet to an embossing apparatus when the base-paper sheet impregnated with a water-soluble binder is embossed, achieving simple manufacturing and low manufacturing cost, and minimizing the likelihood of paper powder remaining on a dry surface of a cleaned object after use. To produce water-disintegrable paper, a base-paper sheet 2 in a non-wet state before a water-soluble binder is impregnated is embossed in order to form a bulking unit 17 , made up of a plurality of uneven elements 12 , on the base-paper sheet 2 ; a water-soluble binder solution 5 is sprayed to the base-paper sheet 2 having the bulking unit 17 formed, from outside of a face of the base-paper sheet 2 to impregnate the water-soluble binder solution 5 into the base-paper sheet 2 ; the base-paper sheet 2 impregnated with the water-soluble binder solution 5 is dried; the base-paper sheet 2 is folded after the drying; and an aqueous chemical solution is sprayed to the base-paper sheet 2 thus being folded to impregnate the aqueous chemical solution into the base-paper sheet 2.

1 - 4 . (canceled) 
     
     
         5 : A method for producing a water-disintegrable sheet, the method comprising:
 applying pulp to a belt conveyer;   creating at least one layer of pulp on the belt conveyor;   applying pressure to the at least one layer of pulp with a roller;   applying a wet water-soluble binder to the at least one layer of pulp only after applying pressure to the at least one layer of pulp with the roller;
 wherein the water-soluble binder is applied to a first surface of the at least one layer of pulp to impregnate the at least one layer of pulp with the water-soluble binder; 
 wherein the water-soluble binder is applied to a second surface of the at least one layer of pulp to impregnate the at least one layer of pulp with the water-soluble binder; and 
   drying the at least one layer of pulp.   
     
     
         6 : The method for producing a water-disintegrable sheet according to  claim 5 , further comprising:
 folding the at least one layer of pulp; and   cutting the at least one layer of pulp into predetermined dimensions.   
     
     
         7 : The method for producing a water-disintegrable sheet according to  claim 6 , further comprising:
 supplying an aqueous chemical to the at least one layer of pulp to impregnate the aqueous chemical into the at least one layer of pulp.   
     
     
         8 : The method for producing a water-disintegrable sheet according to  claim 5 , wherein the roller is an embossing roller. 
     
     
         9 : The method for producing a water-disintegrable sheet according to  claim 8 , further comprising:
 forming a plurality of uneven elements on the at least one layer of pulp with the embossing roller.   
     
     
         10 : The method for producing a water-disintegrable sheet according to  claim 5 , further comprising:
 applying a crosslinker to the at least one layer of pulp.   
     
     
         11 : The method for producing a water-disintegrable sheet according to  claim 10 , wherein the crosslinker is applied to the at least one layer of pulp after the application of the water-soluble binder and before a folding of the at least one layer of pulp. 
     
     
         12 : The method for producing a water-disintegrable sheet according to  claim 10 , wherein the crosslinker is calcium chloride. 
     
     
         13 : The method for producing a water-disintegrable sheet according to  claim 5  wherein the pulp comprises softwood pulp. 
     
     
         14 : The method for producing a water-disintegrable sheet according to  claim 5 , wherein the binder comprises carboxymethylcellulose. 
     
     
         15 : The method for producing a water-disintegrable sheet according to  claim 5 , wherein the crying of the at least one layer of pulp is performed with through-flow drying. 
     
     
         16 : The method for producing a water-disintegrable sheet according to  claim 5 , wherein the water-soluble binder applied to the first surface penetrates partway through the at least one layer of pulp towards the second surface. 
     
     
         17 : A water-disintegrable sheet, comprising:
 at least one pressed and dried layer of pulp;
 wherein a roller applied pressure to the at least one pressed and dried layer of pulp; and, 
 comprised within the at least one pressed and dried layer of pulp, a water-soluble binder, 
 wherein the water-soluble binder when wet had been applied to the at least one pressed and dried layer of pulp only after applying pressure to the at least one pressed and dried layer of pulp with the roller; 
 wherein the water-soluble binder was applied to at least a first surface of the at least one pressed and dried layer of pulp to impregnate the at least one pressed and dried layer of pulp with the water-soluble binder; and wherein the at least one pressed and dried layer of pulp impregnated with the water-soluble binder was dried in a dryer. 
   
     
     
         18 : The water-disintegrable sheet according to  claim 17 , further comprising:
 an aqueous chemical impregnated into the at least one pressed and dried layer of pulp.   
     
     
         19 : The water-disintegrable sheet according to  claim 17 , wherein the roller is an embossing roller and a plurality of uneven elements is present in the at least one pressed and dried layer of pulp, formed by the embossing roller on the at least one layer of pulp. 
     
     
         20 : The water-disintegrable sheet according to  claim 17 , wherein the dryer is a through-flow dryer. 
     
     
         21 : The water-disintegrable sheet according to  claim 17 , further comprising:
 a crosslinker applied to the at least one pressed and dried layer of pulp.   
     
     
         22 : The water-disintegrable sheet according to  claim 21 , wherein the crosslinker is calcium chloride. 
     
     
         23 : The water-disintegrable sheet according to  claim 17 , wherein the pulp comprises softwood pulp. 
     
     
         24 : The water-disintegrable sheet according to  claim 17 , wherein the binder comprises carboxymethylcellulose.