WO2016194460A1

WO2016194460A1 - Water-disintegrable sheet

Info

Publication number: WO2016194460A1
Application number: PCT/JP2016/060510
Authority: WO
Inventors: 慎也和泉; 朝子田中; 敦子長谷澤; 真平向山; 孝介山崎
Original assignee: 大王製紙株式会社
Priority date: 2015-05-29
Filing date: 2016-03-30
Publication date: 2016-12-08
Also published as: EP3305983A1; KR20180013876A; EP3305983B1; CN107532389A; KR102510363B1; EP3305983A4; US20180146834A1

Abstract

A water-disintegrable sheet that comprises a base paper sheet, said base paper sheet containing a water-soluble binder added thereto, impregnated with a chemical solution, wherein: the base paper sheet is prepared by ply processing multiple sheets of base paper, has a basis weight (metsuke) 30-150 gsm, and has a composition ratio of softwood pulp to hardwood pulp of less than 1/1; the chemical solution contains a crosslinking agent for crosslinking the water-soluble binder and a tri- or higher hydric alcohol; and the base paper sheet is impregnated with 1-20 wt% of the tri- or higher hydric alcohol on the weight basis.

Description

Water disintegratable sheet

The present invention relates to a water disintegratable sheet.

Conventionally, woven cloth cloths that are used repeatedly have been used for cleaning toilets. Instead, disposable wet sheets made of paper have been used in recent years. And this type of wet sheet is preferably provided in a state of being impregnated with a cleaning agent, and can be processed by flowing into a toilet after use.
In such wet sheets, it is required to ensure paper strength that does not break in a wet state impregnated with a cleaning agent at the time of wiping work, and water disintegrability that does not clog piping etc. when flowing into a toilet or the like. However, as one technique for effectively achieving these, it is known to use a hydrolytic paper to which a water-soluble binder containing carboxymethylcellulose (CMC) is added as the base paper (for example, Patent Document 1). reference).

Japanese Patent No. 3865506

By the way, when using a water-decomposable sheet impregnated with a chemical solution containing a cleaning agent as a wipe, in order to exert a cleaning effect in the operation of wiping the object, the water-degradability with suppressed moisture transpiration in the chemical solution. A sheet is desired.

This invention was made in view of the said subject, and it aims at providing the water-decomposable sheet which suppressed the transpiration | evaporation of the water | moisture content in a chemical | medical solution.

To solve the above problem,
The invention according to claim 1 is a water-degradable sheet obtained by impregnating a chemical with a base paper sheet to which a water-soluble binder is added,
The base paper sheet is
It is made by plying multiple sheets of paper and has a basis weight of 30 to 150 gsm.
The mixing ratio of softwood pulp to hardwood pulp is less than 1/1,
The chemical solution includes a crosslinking agent that causes a crosslinking reaction to the water-soluble binder, and a polyhydric alcohol having a valence of 3 or more,
1 to 20% by weight of the trihydric or higher polyhydric alcohol is impregnated with respect to the weight of the base paper sheet.

The invention according to claim 2 is a water-degradable sheet obtained by impregnating a chemical with a base paper sheet to which a water-soluble binder is added,
The base paper sheet is
It is made by plying multiple sheets of paper and has a basis weight of 30 to 150 gsm.
The blending ratio of softwood pulp to hardwood pulp is less than 2/3,
The chemical solution includes a crosslinking agent that causes a crosslinking reaction in the water-soluble binder,
150 to 300% by weight of the chemical solution is impregnated with respect to the weight of the base paper sheet.

The invention according to claim 3 is the water-decomposable sheet according to claim 1 or 2,
The base paper sheet is characterized in that the content of the water-soluble binder is increased from the inner side in the thickness direction of the base paper sheet toward the front and back surfaces.

The invention according to claim 4 is the water-decomposable sheet according to any one of claims 1 to 3,
The emboss is formed on the entire surface.

The invention according to claim 5 is the water-decomposable sheet according to claim 4,
The emboss is
With the first embossing,
It has the 2nd embossing which is arranged around the 1st embossing, and has the shape of the bulging part which differs from the 1st embossing.

The invention according to claim 6 is the water-decomposable sheet according to claim 5,
The first embossing is arranged in a rhombus lattice.

The invention according to claim 7 is the water-decomposable sheet according to

claim

5 or 6,
The second embossing is arranged between the two first embossings.

The invention according to claim 8 is the water-decomposable sheet according to any one of claims 5 to 7,
The first embossing and the second embossing are in contact with each other to form an embossing.

According to the present invention, it is possible to provide a water-decomposable sheet that suppresses the transpiration of moisture in the chemical solution.

It is a top view which shows an example of the toilet cleaner which concerns on this embodiment. It is the enlarged view and sectional drawing of the embossed part of a toilet cleaner. It is the enlarged view and sectional drawing of the embossed part of a toilet cleaner. It is the enlarged view and sectional drawing of the embossed part of a toilet cleaner. It is explanatory drawing which shows an example of the contact area of embossing. It is explanatory drawing which shows an example of the contact area of embossing. It is a flowchart which shows the manufacturing method of the toilet cleaner which concerns on this embodiment. It is a schematic diagram which shows an example of the manufacturing equipment (solution provision equipment) of the toilet cleaner which concerns on this embodiment. It is a schematic diagram which shows an example of the manufacturing equipment (processing equipment) of the toilet cleaner which concerns on this embodiment. It is a top view which shows another example of the toilet cleaner which concerns on this embodiment. It is a top view which shows another example of the toilet cleaner which concerns on this embodiment. It is the elements on larger scale of A of FIG. FIG. 10 is a BB end view of FIG. 9. FIG. 10 is a CC end view of FIG. 9.

Hereinafter, a water-decomposable sheet that is an embodiment of the present invention will be described in detail with reference to the drawings. However, the scope of the invention is not limited to the illustrated examples.

In the water-decomposable sheet according to the present invention, the water-decomposable sheet will be described using the toilet cleaner 100 as an example, but the water-decomposable sheet according to the present invention is a wet tissue impregnated with a chemical solution for wiping purposes other than the toilet cleaner. Is also included. Further, the paper conveyance direction at the time of manufacturing the toilet cleaner 100 will be described as the Y direction (vertical direction), and the direction orthogonal to the conveyance direction will be described as the X direction (lateral direction).

[Composition of toilet cleaner 100]
First, the configuration of the toilet cleaner 100 will be described.
The toilet cleaner 100 is obtained by plying (stacking) a plurality of (for example, two) base papers, and is impregnated with a predetermined chemical solution. Moreover, as shown in FIG. 1, two types of embossing EM11 and EM12 are given to the whole sheet | seat surface of the toilet cleaner 100 by embossing. The contact area between the two embossing EM11 and such cleaning object caused by EM12 is, 100 mm ² per ^is preferably 15 mm 2 ~ 30 mm ² approximately.

For example, by arranging the embossed EM11 to be a rhombus lattice, it is possible to reduce wiping unevenness as compared with the case where the embossed EM11 is disposed in a square lattice or a rectangular lattice. Further, the embossing EM12 is disposed between the embossing EM11.

Also, the toilet cleaner 100 is folded in half at the center in the longitudinal direction (Y direction) by being folded. Then, it is stored in a folded plastic case, packaging film, etc. in a folded state, and is expanded and used as needed during use. Note that the method of folding the toilet cleaner 100 is not limited to two, and may be, for example, four or eight.

Also, the toilet cleaner 100 of the present embodiment is composed of a water-decomposable fiber assembly so that it can be discarded as it is in a toilet bowl after the toilet is cleaned.

As the fiber assembly, mixed fibers of hardwood bleached kraft pulp (LBKP) and softwood bleached kraft pulp (NBKP) are used. As a suitable raw material fiber, the component ratio of the hardwood bleached kraft pulp exceeds 50% by weight, that is, the blending ratio of the softwood bleached kraft pulp to the hardwood bleached kraft pulp is less than 1/1. Can be given. As a more suitable raw material fiber, the component ratio of the hardwood bleached kraft pulp exceeds 60% by weight, that is, the blending ratio of the softwood bleached kraft pulp to the hardwood bleached kraft pulp is less than 2/3. Things can be raised. By increasing the blending ratio of hardwood bleached kraft pulp compared to softwood bleached kraft pulp, it is possible to reduce the gap between fibers and suppress the transpiration of moisture in the chemical solution. In order to improve the strength of the base paper sheet that is the base material of the toilet cleaner 100, carboxymethyl cellulose (CMC) is applied to the base paper sheet as a paper strength enhancer. More specifically, it is applied so that the content of CMC increases from the inner side in the thickness direction of the base paper sheet toward the front and back surfaces.

Further, the toilet cleaner 100 of the present embodiment is impregnated with a predetermined chemical solution. Specifically, in addition to an aqueous cleaning agent, a fragrance, an antiseptic, a disinfectant, a paper strength enhancer, an organic solvent, and the like. A predetermined chemical solution containing an auxiliary agent is impregnated. The chemical solution is preferably impregnated in an amount of 150 to 300% by weight based on the weight of the base paper sheet that is the base material of the toilet cleaner 100.

As the chemical solution, an appropriate one can be used. For example, as the aqueous cleaning agent, a surfactant or a lower or higher (aliphatic) alcohol can be used. As a fragrance | flavor, 1 type or several types can be suitably selected and used out of oil-based fragrance | flavors, such as orange oil other than an aqueous | water-based fragrance | flavor. As the preservative, for example, parabens such as methyl paraben, ethyl paraben, propyl paraben and the like can be used. As a disinfectant, for example, benzalkonium chloride, chlorhexidine gluconate, popidone iodine, ethanol, benzilium cetyl oxide, triclosan, chlorxylenol, isopropylmethylphenol and the like can be used. As the paper strength enhancer (crosslinking agent), boric acid, various metal ions, and the like can be used. As the organic solvent, polyhydric alcohols such as glycol (divalent), glycerin (trivalent), and sorbitol (tetravalent) can be used. In the toilet cleaner 100 of the present embodiment, at least a trihydric or higher polyhydric alcohol such as glycerin or sorbitol is used as the organic solvent. Thereby, the viscosity of the chemical | medical solution impregnated to a base paper sheet can be raised, and the evaporation of the water | moisture content in a chemical | medical solution can be suppressed. The trihydric or higher polyhydric alcohol is preferably impregnated in an amount of 1 to 20% by weight based on the weight of the base paper sheet. The upper limit of the content is set to 20% by weight in order to suppress a decrease in yield due to excessive increase in the viscosity of the chemical solution.

Further, the above-mentioned adjuvants for the components of the chemical solution can be appropriately selected, and components that perform other functions may be included in the chemical solution as necessary.

In the embossed EM11, as shown in FIG. 2A, the bulging portion PR21 has a curved shape.

Further, as shown in FIG. 2B, the embossing EM12 has a bulged portion PR22 having a planar shape.

And since the embossing EM12 is arrange | positioned between the embossing EM11, the bulging part PR21 of embossing EM11 and the bulging part PR22 of EM12 adjoin and closely_contact | adhere, as shown to FIG. Will be formed.
Moreover, the case where the bulging part PR21 of the embossing EM11 and the bulging part PR22 of the embossing EM12 are only close to each other and may not be continuous may be used.

Since the two types of embosses EM11 and EM12 formed in this way can increase the contact area with the object to be cleaned, the hardness of the toilet cleaner 100 is reduced and the wiping performance is improved.

That is, by forming the embossed EM11 whose bulged portion PR21 is a curved surface and the embossed EM12 whose bulged portion PR22 is a flat surface on the entire sheet surface of the toilet cleaner 100, the toilet cleaner 100 is powered during wiping work. When each emboss is deformed, the contact area is increased for the first time. Therefore, the contact area is increased, and the flexibility is improved due to the deformation of each emboss.

For example, as shown in FIG. 3A, in the case of a single emboss EM11, the contact area CN31 generated by the deformation of the emboss EM11 due to the force applied to the toilet cleaner 100 during the wiping operation occurs discretely in the vicinity of the emboss EM11. . On the other hand, when two types of embossing EM11 and EM12 are combined, as shown in FIG. 3B, the contact area CN32 generated by the deformation of the embossing EM11 and EM12 due to the force applied to the toilet cleaner 100 during the wiping operation is It can be seen that the contact area CN31 of FIG. 3A increases.

Moreover, two types of embossing EM11 and EM12 can obtain the effect of normal embossing similarly, and can improve the texture, absorbability, bulkiness, etc. of a toilet cleaner. Furthermore, the continuous embossing EM21 can also obtain the effect of the appearance by giving embossing similarly to normal embossing.

[Manufacturing method of toilet cleaner 100]
Next, a method for manufacturing the toilet cleaner 100 will be described.
FIG. 4 is a flowchart showing a method for manufacturing the toilet cleaner 100. FIG. 5 is a schematic diagram of a solution application facility that applies a binder solution containing a water-soluble binder to the base paper sheet of the toilet cleaner 100. FIG. 6 is a schematic diagram of a processing facility for processing the base paper sheet to which the binder solution is applied by the solution application facility shown in FIG.

In the manufacturing method of the toilet cleaner 100, as shown in FIG. 4, first, a paper making process (S1) for making a paper as a base paper is performed by a paper machine (not shown).

Next, as shown in FIG. 4 and FIG. 5, in the solution application facility, continuous dry base paper 1 </ b> A fed out from a plurality of (for example, two) primary raw rolls 1, 1 each wound up a base paper that has been made, A ply processing step (S2) for plying 1A to form a ply continuous sheet 1B, a solution application step (S3) for applying a binder solution to the ply continuous sheet 1B to form a continuous sheet 1C, and drying the continuous sheet 1C A drying process (S4) and a slit / winding process (S5) for slitting and winding the dried continuous water-decomposable sheet 1D are performed. The number of primary rolls can be changed as long as there are two or more. However, in the following description, an example of using two primary rolls will be described.

Next, as shown in FIGS. 4 and 6, in the processing facility, the continuous water-decomposable sheet 1 </ b> D fed from the secondary raw roll 11 wound in the slit / winding step (S <b> 5) is embossed. An embossing process (S6) and a finishing process (S7) for finishing the embossed sheet 1E that has been embossed are performed. Details of each process will be described later.

[Paper making process]
The paper making process according to the present invention will be described. In the papermaking process of the present invention, for example, a raw paper sheet is formed by papermaking using a known wet papermaking technique. That is, after making the papermaking raw material into a wet paper state, it is dried by a dryer or the like to form a base paper sheet such as thin paper or crepe paper.
As a raw material of the base paper sheet, for example, known virgin pulp, waste paper pulp and the like can be used, and at least pulp fibers are included. As the pulp used as the raw material, a blend of LBKP and NBKP in an appropriate ratio is particularly suitable. In addition, rayon fiber, synthetic fiber, etc. may contain as fibers other than a pulp fiber.
The base paper sheet of the present invention contains an anionic acrylamide polymer (hereinafter referred to as “anionic PAM”) as a flocculant. An anionic PAM is a polymer obtained by copolymerizing an acrylamide monomer and an anionic monomer.
Examples of the acrylamide monomer include acrylamide alone or a mixture of acrylamide and the following nonionic monomer copolymerizable with acrylamide. Nonionic monomers copolymerizable with acrylamide include methacrylamide, N, N-dimethylacrylamide, N, N-diethylacrylamide, N-isopropylacrylamide, N-isopropylacrylamide, N-hydroxyethylacrylamide, diacetone. Examples include acrylamide, acryloylmorpholine, N-acryloylpyrrolidine, N-acryloylpiperidine, N-vinylrolidone, N-vinylformamide, and N-vinylacetamide. These may be used alone or in combination of two or more.
Examples of the anionic monomer include acrylic acid, methacrylic acid, acrylamido-2-methylpropanesulfonic acid, itaconic acid, maleic acid, fumaric acid, and neutralized salts thereof.
A monomer such as styrene, acrylonitrile, (meth) acrylic acid ester, or the like may be blended as long as the water solubility of the anionic PAM is not impaired.
The addition amount of the anionic PAM is preferably about 10 to 1000 ppm. By making paper using such an anionic flocculant having the same charge as pulp, the aggregation of the base paper sheet can be reduced, and the water disintegrability can be improved by capillary action.
In addition to the above-described pulp and flocculant, papermaking chemicals such as a wet paper strength agent, an adhesive, and a release agent may be appropriately used for the base paper sheet.

[Continuous dry base paper]
As physical properties of the continuous dry base paper 1A, the basis weight is preferably about 15 to 75 gsm. The basis weight of the ply-processed sheet containing the water-soluble binder (continuous water-decomposable sheet 1D) is about 30 to 150 gsm. The basis weight is based on JIS P 8124.
The continuous dry base paper 1A becomes a ply-processed hydrolyzed paper through a ply processing step (S2), a solution application step (S3), a drying step (S4), and a slit / winding step (S5), which will be described later. The toilet cleaner 100 is processed through an embossing process (S6) and a finishing process (S7).

[Ply processing process]
Next, the ply processing step (S2) of this embodiment will be described. In the ply processing step (S2), as shown in FIG. 5, the continuous

dry base papers

1A and 1A continuously fed from the raw roll 1 are ply processed along the continuous direction to form a ply continuous sheet 1B. It is supplied to the mating unit 2. The overlapping portion 2 is composed of a pair of rolls, and plies each

continuous base paper

1A, 1A to form a ply continuous sheet 1B subjected to ply processing. In addition, when the continuous

dry base papers

1A and 1A are overlapped, the continuous

dry base papers

1A and 1A may be lightly fastened with pin embossing (contact embossing) so that they are not easily displaced.

[Binder solution]
Next, the binder solution will be described. The binder solution contains carboxymethyl cellulose (CMC) as a water-soluble binder. The concentration of carboxymethylcellulose in the binder solution is 1 to 30% by weight, preferably 1% by weight or more and less than 4% by weight.

On the other hand, the degree of etherification of CMC is desirably 0.6 to 2.0, particularly 0.9 to 1.8, and more preferably 1.0 to 1.5. The expression of water disintegration and wet paper strength is very good.

Moreover, CMC can use a water swelling thing. This demonstrates the function of tying together the fibers constituting the sheet while remaining unswelled by crosslinking of specific metal ions in the chemical solution, and can exhibit strength as a wiping sheet that can withstand cleaning and wiping operations.

Ingredients other than carboxymethylcellulose in the binder solution include polyvinyl alcohol, starch or derivatives thereof, hydroxypropylcellulose, sodium alginate, tolton gum, guar gum, xanthan gum, gum arabic, carrageenan, galactomannan, gelatin, casein, albumin, pull plan, poly Examples thereof include binder components such as ethylene oxide, viscose, polyvinyl ethyl ether, polyacrylic acid soda, polymethacrylic acid soda, polyacrylamide, hydroxylated derivatives of polyacrylic acid, and polyvinylpyrrolidone / vinylpyrrolidone vinyl acetate copolymer.

It is preferable to use a water-soluble binder having a carboxyl group from the viewpoint of good water decomposability and a point at which wet strength can be expressed by a crosslinking reaction.
The water-soluble binder having a carboxyl group is an anionic water-soluble binder that easily forms a carboxylate in water. Examples thereof include polysaccharide derivatives, synthetic polymers, and natural products. Examples of the polysaccharide derivative include a salt of carboxymethyl cellulose, carboxyethyl cellulose or a salt thereof, carboxymethylated denven or a salt thereof, and an alkali metal salt of carboxymethyl cellulose is particularly preferable.

Examples of the synthetic polymer include a polymer or copolymer salt of an unsaturated carboxylic acid, a salt of a copolymer of an unsaturated carboxylic acid and a monomer copolymerizable with the unsaturated carboxylic acid, and the like. Examples of the unsaturated carboxylic acid include acrylic acid, methacrylic acid, itaconic acid, crotonic acid, maleic anhydride, maleic acid, and fumaric acid. Examples of monomers that can be copolymerized with these include esters of these unsaturated carboxylic acids, vinyl acetate, ethylene, acrylamide, and vinyl ether. Particularly preferred synthetic polymers are those using acrylic acid or methacrylic acid as the unsaturated carboxylic acid. Specifically, polyacrylic acid, polymethacrylic acid, acrylic acid-methacrylic acid copolymer salt, acrylic acid or methacrylic acid. Examples thereof include a salt of a copolymer of an acid and an alkyl acrylate or an alkyl methacrylate. Examples of natural products include sodium alginate, xanthan gum, gellan gum, tarragant gum, pectin and the like.

[Solution application process]
Next, the solution application step (S3) of this embodiment will be described. In the solution application step (S3), as shown in FIG. 5, two fluids are formed on both outer surfaces of the ply continuous sheet 1B (the surfaces where the continuous

dry base papers

1A and 1A do not face each other when the continuous

dry base papers

1A and 1A are plyed). The above-mentioned binder solution is sprayed by the

spray nozzles

3 and 3 of the system. Thereby, the water-soluble binder contained in a binder solution can be added to the ply continuous sheet 1B.
In addition, as a spraying method of the binder solution, for example, with respect to the outer surfaces (surfaces where the sheets do not face each other) of the continuous

dry base papers

1A and 1A fed out from the primary raw rolls 1 and 1 described above, respectively. You may make it produce | generate the sheet | seat equivalent to the above-mentioned continuous sheet 1C by spraying the above-mentioned binder solution from each spray nozzle of a fluid system, and plying the said continuous

dry base paper

1A and 1A immediately after.

The two-fluid spray nozzle 3 is a spray nozzle that mixes and sprays compressed air and liquid divided into two systems, compared to a one-fluid spray nozzle that sprays compressed liquid alone, The liquid can be sprayed finely and uniformly.
When a two-fluid spray nozzle is used in the present embodiment, a binder solution (viscosity 400 to 1200 MPa.s) is applied to each outer surface of the ply-processed ply continuous sheet 1B with a high pressure (injection pressure of 1.5 MPa or more). Since it is applied, it is easy to impregnate the binder solution in the thickness direction of the sheet.
On the other hand, when a one-fluid spray nozzle is used in this embodiment, a binder solution (viscosity 400 to 1200 MPa.s) is applied to the outer surface of each ply-processed ply continuous sheet 1B at an injection pressure of 1.5 MPa or less. Thus, the binder solution is easily impregnated in the thickness direction of the sheet, and the binder solution is easily applied uniformly on the sheet surface.

[Drying process]
Next, the drying step (S4) of this embodiment will be described. In the drying step (S4), as shown in FIG. 5, in the drying equipment 4, the insoluble liquid in the binder solution of the continuous sheet 1C is evaporated to fix the active ingredient, particularly CMC, to the fibers. .
Here, the amount of penetration of the binder solution decreases from the outer surface (front surface and back surface) of the continuous sheet 1C toward the inner side in the thickness direction, so that the fixing amount of CMC decreases toward the inner side in the thickness direction. Will be. Therefore, when the chemical solution is impregnated in the finishing step (S7) described later, the cross-linking reaction hardly occurs as it goes inward in the thickness direction, and since there are many voids, the chemical solution is confined inside the sheet. be able to. Thereby, the toilet cleaner 100 obtained can be made hard to dry. In addition, since many CMC cross-linking reactions occur in the vicinity of the outer surface of the continuous sheet 1C, the surface strength of the obtained toilet cleaner 100 can be strengthened.
As the drying equipment 4, a hooded dryer equipment that blows hot air on the continuous sheet 1C to dry it can be used. In order to make the sheets more closely contact each other, a press roll or a turn roll may be installed, and the continuous sheet 1C may be passed through the press roll or the turn roll before the drying step (S4).

Moreover, an infrared irradiation facility may be used as the drying facility. In this case, a plurality of infrared irradiation units are arranged in parallel in the conveying direction of the continuous sheet 1C, and drying is performed by irradiating the continuous sheet 1C to be conveyed with infrared rays. Since moisture is generated by infrared rays and dried, uniform drying is possible as compared with a dryer using hot air, and wrinkles can be prevented from occurring in the subsequent slit / winding process.

[Slit and winding process]
Next, the slit / winding step (S5) of this embodiment will be described. In the slit / winding step (S5), in order to use the ply-processed continuous water-decomposable sheet 1D with an off-line processing machine, it is dried in the above-described drying step (S4) and the CMC is fixed. The illustrated continuous water-decomposable sheet 1D is slit to a predetermined width by the slitter 5 while adjusting the tension, and wound by the winder facility 6. The winding speed is appropriately determined in consideration of the ply processing step (S2), the solution application step (S3), and the drying step (S4). Note that if it is too early, the sheet will break, and if it is too late, wrinkles will occur.
In the slit / winding step (S5), the continuous water-decomposable sheet 1D subjected to the ply process is pressure-bonded, whereby the continuous water-decomposable sheet 1D is more integrated and becomes a sheet corresponding to one sheet.

[Embossing process]
Next, the embossing process (S6) of this embodiment will be described. In the embossing step (S6), as shown in FIG. 6, the embossing roll 12 has an embossing process that forms a predetermined shape on the entire surface of the continuous water-decomposable sheet 1D fed from the secondary raw roll 11 by the embossing roll 12. Applied. This embossing is performed for the purpose of improving the strength, bulkiness, wiping property and the like of the sheet, as well as the design.

[Finishing process]
Next, the finishing process (S7) of this embodiment will be described. In the finishing process (S7), as shown in FIG. 6, in the finishing equipment 13, the embossed sheet 1E is cut, the cut sheets are folded, and the chemicals are applied to the folded sheets. Impregnation and packaging of each sheet impregnated with the chemical solution are performed in a series of flows. Here, when CMC is used as the water-soluble binder, the cross-linking agent contained in the chemical solution is preferably a polyvalent metal ion. In particular, the use of one or more polyvalent metal ions selected from the group consisting of alkaline earth metals, manganese, zinc, cobalt, and nickel allows the fibers to be sufficiently bonded to withstand use. It is preferable from the standpoint that strength is developed and water disintegration is sufficient. Of these metal ions, it is particularly preferable to use ions of calcium, strontium, barium, zinc, cobalt, and nickel.
The toilet cleaner 100 is manufactured through the above steps.

As described above, according to the present embodiment, the blending ratio of softwood bleached kraft pulp with respect to hardwood bleached kraft pulp is less than 1/1, and by increasing the blending ratio of hardwood bleached kraft pulp as compared with softwood bleached kraft pulp It is possible to reduce the gap between the fibers and suppress the transpiration of moisture in the chemical solution. In addition, since 1 to 20% by weight of a polyhydric alcohol having a valence of 3 to 20% by weight is impregnated with respect to the weight of the base paper sheet, the sheet can be made to be viscous and water evaporation in the chemical solution can be further suppressed. Can do.
Furthermore, since the base paper sheet (continuous sheet 1C) is in a state in which the content of CMC is increased from the inner side in the thickness direction of the base paper sheet toward the front and back surfaces, the base paper sheet is impregnated with a chemical solution containing a crosslinking agent. When this is done, the cross-linking reaction hardly occurs as it goes inward in the thickness direction, and there are many voids, so that the chemical solution can be confined inside the sheet. Thereby, the toilet cleaner 100 obtained can be made hard to dry. In addition, since many CMC cross-linking reactions occur in the vicinity of the outer surface of the base paper sheet, the surface strength of the obtained toilet cleaner 100 can be strengthened.

As mentioned above, although this invention was concretely demonstrated based on embodiment, this invention is not limited to the said embodiment, It can change in the range which does not deviate from the summary.
In describing the embodiment of the present invention, the embossed EM11 in which the bulging part PR21 has a curved shape and the embossing EM12 in which the bulging part PR22 has a flat shape are illustrated. It is not necessarily limited to this shape, for example, the bulging part of embossing EM11 and embossing EM12 may be a planar shape from which height differs. Further, for example, the bulging portion of the emboss EM 11 may be a flat shape, and the bulging portion of the emboss EM 12 may be a curved shape.

In other words, there are two types of embossing (first embossing and second embossing) in which the shape of the bulging part is not the same shape, and the second embossing is arranged around the first embossing. If it exists, the shape of the bulging portion of each emboss may be any shape.

In the description of the embodiment of the present invention, the embossed EM12 having a flat bulge is disposed between the embossed EM11 having a curved bulge, but the embossed EM11 intersects each other. Also good.

In the description of the embodiment of the present invention, all the embosses EM11 and EM12 are convex toward the front side of the drawing in FIG. Alternatively, the concave embosses EM11 and EM12 may be alternately arranged.

For example, as shown in FIG. 7, embosses EM11 and EM12 (solid line portions) convex in the front direction of FIG. 7 and embossments EM11 and EM12 (broken line portions) concave in the front direction of FIG. Thus, it is possible to increase the surface strength of household thin paper by embossing and to provide household thin paper having high wiping performance on both sides of the toilet cleaner 100.

In the description of the embodiment of the present invention, the bulging portion PR21 of the emboss EM11 and the bulging portion PR22 of the EM12 are formed as a continuous embossing EM21 by closely adhering to each other. The bulging portion PR21 and the bulging portion PR22 of the EM 12 may be close to each other but not closely attached.

In the description of the embodiment of the present invention, the shape of the emboss EM 11 is exemplified as a circular shape or an elliptical shape, but the emboss shape may be any shape such as a square or a polygon.

Further, the heights HT21 and HT22 of the bulging portions of the embosses EM11 and EM12 in FIG. 2 are preferably 0.40 mm to 0.75 mm, for example. For example, the surface is 3D measured with a digital microscope manufactured by Keyence, and the heights HT21 and HT22 of the bulges of the embosses EM11 and EM12 are measured.

For example, if the height is less than 0.40 mm, the friction at the time of wiping becomes strong and difficult to wipe, and if the height exceeds 0.75 mm, the shapes of the embosses EM11 and EM12 are liable to break during packaging. It looks bad.

Further, the emboss pattern is not limited to the above-mentioned pattern, and may be an emboss pattern as shown in FIGS. As shown in FIGS. 8 to 10, the concave portion e2 has a shape obtained by inverting the convex portion e1. The convex portions e1 and the concave portions e2 are alternately arranged as an example, and this row forms an emboss pattern in which the rows are arranged in multiple rows and the convex portions e1 and the concave portions e2 in adjacent rows are shifted from each other by a half pitch. . As described above, the convex portions e1 and the concave portions e2 are alternately formed both in the vertical direction and in the horizontal direction, so that the wiping property of dirt is improved compared to the embossed pattern in which the convex portions and the concave portions are arranged in a line. Can be made. In addition, the shape of the convex part e1 and the recessed part e2 is not specifically limited, Circular, an ellipse, a polygon etc. are used. It is good also as what combined each shape.

The present invention can be suitably used in the field of manufacturing a water-decomposable sheet.

DESCRIPTION OF SYMBOLS 100 Toilet cleaner 1 Primary raw material roll 1A Continuous dry base paper 1B Ply continuous sheet 1C Continuous sheet 1D Continuous water-decomposable sheet 1E Embossed sheet 2 Superposition part 3 Spray nozzle 4 First drying equipment 5 Slitter 6 Winder equipment 11 Secondary raw material Anti-roll 12 Embossing roll 13 Finishing equipment EM11 Embossing EM12 Embossing EM13 Embossing PR21 Swelling part PR22 Swelling part

Claims

A water-degradable sheet obtained by impregnating a chemical with a base paper sheet to which a water-soluble binder is added,
The base paper sheet is
It is made by plying multiple sheets of paper and has a basis weight of 30 to 150 gsm.
The mixing ratio of softwood pulp to hardwood pulp is less than 1/1,
The chemical solution includes a crosslinking agent that causes a crosslinking reaction to the water-soluble binder, and a polyhydric alcohol having a valence of 3 or more,
A water-decomposable sheet, which is impregnated with 1 to 20% by weight of the trihydric or higher polyhydric alcohol based on the weight of the base paper sheet.
A water-degradable sheet obtained by impregnating a chemical with a base paper sheet to which a water-soluble binder is added,
The base paper sheet is
It is made by plying multiple sheets of paper and has a basis weight of 30 to 150 gsm.
The blending ratio of softwood pulp to hardwood pulp is less than 2/3,
The chemical solution includes a crosslinking agent that causes a crosslinking reaction in the water-soluble binder,
A water-decomposable sheet which is impregnated with 150 to 300% by weight of the chemical solution based on the weight of the base paper sheet.
The water-decomposable sheet according to claim 1 or 2, wherein the base paper sheet is in a state in which the content of the water-soluble binder is increased from the inside in the thickness direction of the base paper sheet toward the front and back surfaces.
The water-decomposable sheet according to any one of claims 1 to 3, wherein an emboss is formed on the entire surface.
The emboss is
With the first embossing,
5. The water-decomposable sheet according to claim 4, further comprising: a second emboss disposed around the first emboss and having a shape of a bulging portion different from the first emboss.
The water-decomposable sheet according to claim 5, wherein the first embosses are arranged in a rhombus lattice.
The water-decomposable sheet according to claim 5 or 6, wherein the second emboss is arranged between the two first embosses.
The water-decomposable sheet according to any one of claims 5 to 7, wherein the first emboss and the second emboss are in contact with each other to form an emboss.