JP2009178454A - Water soluble sanitary tissue paper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide water soluble sanitary tissue paper in which appearance and water solubility are enhanced. <P>SOLUTION: In the water soluble sanitary tissue paper constituted by superimposing at least two sheets of tissue paper, at least one sheet of tissue paper has emboss and is adhered to the adjacent tissue paper by an adhesive applied to top portions of the convex portions of the emboss, and the adhesive used for adhering the tissue paper each other is one constituted by coloring the aqueous adhesive base material by an aqueous coloring agent. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a sanitary thin paper, particularly a water-decomposable sanitary thin paper excellent in design and texture.

In sanitary thin paper such as toilet paper, a ply structure is often formed by laminating a plurality of sheets in order to prevent slip-through and provide a hand feeling when wiping.
In addition, in sanitary thin paper, embossing and pattern printing are often performed to improve the design, and in particular, those having a ply structure as described above are embossed on a single thin paper constituting the ply. A technique is known in which a colored embossed pattern is formed to enhance design by applying a pigment ink to the top surface of the convex portion and laminating and bonding a plurality of sheets with the ink (Patent Document 1).
The sanitary thin paper obtained by applying pigment ink to the top surface of the embossed convex portion and bonding the thin papers to each other is extremely excellent in design due to the synergistic effect of the embossed unevenness and coloring with the pigment ink. Moreover, the texture and texture of the hand are excellent due to the unevenness of the emboss.

However, this sanitary thin paper having a colored embossed pattern (hereinafter also referred to as a colored embossed sanitary thin paper) has an oily resin component in the pigment ink as an adhesive component, so that it has a general embossed pattern with respect to water disintegration. Inferior.
Moreover, the uneven portion of the emboss is a portion where the density of the paper is high and it is inherently difficult to disintegrate, and this is even more because the portion is further solidified with resin.

In recent years, the thickness of sanitary thin paper tends to be thick due to the spread of shower toilets and the like, and there is also a tendency to increase the embossed area and the colored area for customer appeal by giving a sense of quality. Therefore, improvement of the factor that deteriorates water disintegration is a highly desirable technique.
Furthermore, in the manufacture of sanitary thin paper, the waste paper generated in the manufacturing process is dissolved again with a pulper. However, sanitary thin paper using pigment ink is inferior in water decomposability and requires a long time for dissociation. In particular, in the colored embossed sanitary thin paper, the uneven portions of the emboss remained in the form of particles without being dissolved, which hindered the regeneration of the damaged paper.
Here, there are various techniques for improving the water disintegration property of sanitary thin paper. For example, a technique (Patent Document 2) for appropriately adjusting the longitudinal strength and dry tensile strength of the thin paper of each layer constituting the ply is known. However, this does not fundamentally solve the decrease in water disintegrability caused by applying a pigment ink to the top surface of the convex portion.
JP2007-75510A JP2007-75523

  Then, the main subject of this invention is providing the sanitary thin paper which is very excellent in the designability which has the colored embossed pattern, and also has no difficulty in water decomposability.

The present invention that has solved the above-described problems and the effects thereof are as follows.
<Invention of Claim 1>
In the water-degradable sanitary thin paper that is made by stacking two or more thin papers,
At least one thin paper has an emboss, and is adhered to an adjacent thin paper by an adhesive applied to the top of the convex portion of the emboss,
The water-degradable sanitary thin paper, wherein the adhesive used for adhering the thin papers is obtained by coloring an aqueous adhesive base with an aqueous colorant.

(Function and effect)
Since the water-decomposable sanitary thin paper of the present invention is provided with a colored adhesive on the top surface of the embossed convex part, the embossed uneven part and the coloring are integrated into a peripheral area and partitioned. It appears as a clear embossed pattern, and is extremely excellent in design.
And since the adhesive that bonds the thin papers is an aqueous adhesive base colored with an aqueous colorant, it is highly water-degradable. For example, in addition to disposal performance when using toilet paper, recycled paper The melting work efficiency is greatly improved.

<Invention of Claim 2>
The water-degradable sanitary thin paper according to claim 1, wherein the aqueous adhesive base is a cellulosic adhesive.

(Function and effect)
Because it is made of cellulose-based adhesive, it has a high affinity with pulp fibers, can improve the adhesion of the fibers, is easily dissolved in water, and effectively secures the adhesiveness and water disintegration during drying. .

<Invention of Claim 3>
The water-decomposable sanitary thin paper according to claim 1 or 2, wherein the water-decomposable sanitary thin paper has a paper thickness of 100 to 450 µm and a rice basis of each thin paper is 11 to 25 g / m ² .

(Function and effect)
Water disintegration is further increased.

<Invention of Claim 4>
The water-degradable sanitary thin paper according to any one of claims 1 to 3, wherein the dry tensile strength in the longitudinal direction per sheet of the thin paper is 100 to 800 cN / 25 mm, and the dry tensile strength in the transverse direction is 50 to 350 cN / 25 mm. .

(Function and effect)
The risk of tearing or breaking during use is significantly reduced.

<Invention of Claim 5>
The water-degradable sanitary thin paper according to any one of claims 1 to 4, wherein the aqueous colorant is an aqueous dye, and the aqueous adhesive base contains 10% by weight or less of the aqueous dye.

(Function and effect)
If it is a water-based dye, it will color sufficiently even at a low concentration of 10% by weight or less as compared with the conventional one, and exhibits a desirable design. Thereby, it can manufacture at low cost. Moreover, even if it is a low concentration, it can be colored evenly compared with the pigment.

<Invention of Claim 6>
The water-degradable sanitary thin paper according to any one of claims 1 to 5, wherein the aqueous adhesive base is polyvinyl alcohol or carboxymethyl cellulose, and the coating amount is 0.001 to 0.02 g / m ² in terms of solid content.

(Function and effect)
Use of these water-based adhesive bases makes it particularly excellent in water decomposability.

  As described above, according to the present invention, there is provided a sanitary thin paper having a colored embossed pattern, excellent in design properties, and having no difficulty in water disintegration.

Hereinafter, embodiments of the present invention will be described in detail.
〔Construction〕
The water-decomposable sanitary thin paper according to the present invention takes a form in which at least two thin papers (hereinafter also referred to as base paper sheets) are stacked. The number of base paper sheets to be stacked is not particularly limited, and can be appropriately changed to, for example, 2, 3, 4, or more. In particular, the effect when embossing two or three sheets is remarkable and desirable.

Hereinafter, the structure will be described in more detail with an example in which two base paper sheets are stacked. However, the present invention is not limited to this form.
In the water-decomposable thin paper of this embodiment, design embossing arranged so as to draw a predetermined pattern is given to each of the two base paper sheets stacked. The specific design, size, shape and the like of the design emboss are not particularly limited, and a design such as a logo mark, a number, a character, a geometric pattern, and an appropriate size can be selected. Further, the pattern embossed pattern arranged on each base paper sheet is not necessarily the same.

The area per unit emboss constituting the design emboss is preferably about 0.002 to 0.05 cm ² . If it exceeds 0.05 cm ² , water disintegration deteriorates, and if it is less than 0.002 cm ² , coloring is difficult to recognize. The design embossing should have an embossing density of 3 to 20 pieces / cm ² . When the number is less than 3 / cm ^{2, the} thin papers are not sufficiently bonded to each other, and when the number is more than 20 / cm ^2, there is a high possibility that water disintegration is lowered.

  Each base paper sheet of this water-degradable sanitary thin paper is arranged so that the convex surfaces of the design emboss of each base paper sheet face each other, and the adhesion of the color different from the ground color of the base paper sheet applied to the top surface of the convex portion of the emboss Both base paper sheets are bonded together by the agent. Although details of the adhesive will be described later, this adhesive is obtained by coloring an aqueous adhesive base with an aqueous dye or an aqueous pigment, an oily pigment and an oily dye, and an oily dispersant for dispersing and dissolving the oily pigment or oily dye. What does not contain an oily solvent is used.

  The pattern embossed pattern given to each base paper sheet is the same, and the embossed convex top surfaces of each corresponding emboss are bonded to each other in a so-called Tip to Tip form. However, the water-decomposable sanitary thin paper of the present invention is not limited to this Tip to Tip form, and the top surface of the convex portion of one base paper sheet is bonded to a portion other than the embossed convex portion of the other base paper sheet. Also good.

The application amount of the adhesive can be appropriately increased or decreased depending on the use of the water-degradable sanitary thin paper, but is preferably 0.01 to 2.0 g / m ² . When it exceeds 2.0 g / m ² , it becomes stiff, and when it is less than 0.01 g / m ² , adhesion between the base paper sheets becomes insufficient.

  In the water-decomposable sanitary thin paper of this embodiment, the adhesive is visually recognized from the front and back surfaces of the water-decomposable sanitary thin paper through the base paper sheet, so that the design embossed color is visually recognized.

  Here, in the present invention, since the adhesive is visually recognized from the front and back surfaces of the water-decomposable sanitary thin paper, it constitutes a design. Therefore, the adhesive is sufficiently clear from the front and back surfaces of the water-decomposable sanitary thin paper. The opacity of the base paper sheet based on JIS P 8149 is preferably 30 to 80%, and preferably 60 to 70%. With this level of opacity, the color of the adhesive is clearly visible from the front and back surfaces of the water-degradable sanitary thin paper.

  Here, in the present invention and the present specification, “a color different from the base color of the base paper sheet” means that the hue of the base paper sheet is different, only the saturation and the lightness are different, and the base color of the base paper sheet and the color of the colored paste application portion are different. Includes the case where and form a gradation pattern.

  On the other hand, it is desirable that the difference ΔL * in the L * value in the L * a * b * color system between the adhesive-applied portion and the non-adhesive portion is 3.0 or more. The measurement of the L * value can be performed using, for example, a measurement device “PF-10” manufactured by Nippon Denshoku Industries Co., Ltd. The measurement is made by placing a base paper sheet having one adhesive application portion on a sheet in which 10 or more non-adhesive base paper sheets are stacked so that the adhesive application portion is the inner surface. The L * values of the adhesive-applied portion and the non-adhesive portion are measured from the surface of the test piece on which the adhesive-applied sheet is placed.

On the other hand, in the water-degradable sanitary thin paper of this embodiment, each base paper sheet is not recognized as a pattern, and does not substantially contribute to the adhesion of each sheet. The density is higher than the design embossing and the embossing depth is shallow. Embossing is formed. In addition, the term “substantially” here means that micro embosses may be bonded to each other in a portion where design embosses are superimposed on micro embosses, but this is not taken into consideration. .
In this embodiment, as a preferred embodiment, the micro embossed convex portions of each base paper sheet face each other in close proximity.

As for the micro embossing, the area per unit embossing is desirably about 0.002 to 0.004 cm ² . It is preferable that the emboss density is 30 to 100 pieces / cm ² and the emboss depth is 0.05 to 2.0 mm. About the shape of the unit emboss of a micro emboss, it can be set as an appropriate shape.

〔Production method〕
In producing the water-decomposable sanitary thin paper of this embodiment as described above, for example, it can be performed as follows. First, the base paper sheet is micro embossed by a known micro embossing roll device over a substantially entire area of preferably 60% or more, more preferably 90% or more, from the viewpoint of improving touch.

Next, each base paper sheet is subjected to a design embossing roll through a design embossing roll that nips a pair of a metal convex embossing roll having a pattern formed on the surface and a rubber restraining roll for providing design embossing. .
After the base paper sheet passes between the design embossing rolls and is embossed, it is separated from the rubber restraining rolls, guided and moved along the metal convex embossing rolls, and the embossing convex top surface part, An adhesive in which a dye is dissolved in advance is applied by a glue unit using a doctor chamber method, and finally transferred and applied by a transfer roll.

Next, the two base paper sheets are overlapped and bonded by the overlapping roll so that the convex surface of the design emboss faces each other.
Thus, a water-degradable sanitary thin paper with an unprecedented design in which the color of the adhesive is visually recognized from the front and back surfaces of the water-decomposable sanitary thin paper, and the design based on the coloring of the adhesive and the embossed pattern is formed. Is manufactured.

  In addition, if the metal embossing roll which has two or more types of embossing patterns from which an embossing depth (it is also height) differs is used, it is possible to give two or more types of embossing from which height differs. In this case, as can be seen immediately from the transfer system, the adhesive can be applied only to the embossment with a high embossing height, and the embossed convex top portion where the adhesive is applied and the embossing where the adhesive is not applied A convex top part can be formed.

  In the above embodiment, the design emboss of the two base paper sheets is the same design, and both base paper sheets are overlapped so that the design embosses overlap each other, but design embosses of different designs are given to each base paper sheet. In addition, the design embossing may not be overlapped with each other, and a form of a water-decomposable sanitary thin paper in which base paper sheets are bonded to each other can also be used.

[About adhesive]
Next, the characteristic adhesive of the present invention will be described. Here, the adhesive is a colored adhesive that is applied to the top surface of the convex portion of the design emboss of the base paper sheet to bond the base paper sheets together.

The adhesive of the present invention is characteristically obtained by coloring an aqueous adhesive base with an aqueous colorant. Specifically, it is colored by dissolving or dispersing an aqueous dye or aqueous pigment in an aqueous adhesive base.
Specific examples of the water-based adhesive substrate include PVA (polyvinyl alcohol), CMC (carboxymethylcellulose) and the like. A particularly preferred aqueous adhesive base is a cellulose-based aqueous adhesive base, and a specific example thereof is CMC.

On the other hand, known aqueous dyes can be used as the aqueous dye. Examples of the dye include phthalocyanine dyes and azo metal complex dyes. As the aqueous pigment, known aqueous pigments can be used. Examples thereof include aluminum hydroxide, kaolin, talc, calcium carbonate, titanium dioxide, clay, and zinc oxide.
The specific colors of these water-based dyes and water-based pigments may be determined as appropriate in relation to the pattern by design embossing, and are not particularly limited.
In addition, the water-based dye and the water-based pigment can be used in combination within a possible range. For example, in addition to the combined method of simultaneously mixing in the adhesive base and coloring the adhesive base, if the base paper sheet is bonded using a plurality of color adhesives, one is colored with an aqueous pigment, the other May be properly used depending on the adhesion part, such as an adhesive colored with an aqueous dye. In this case, it can be appropriately selected in consideration of the cost of the pattern and the dye, color developability, and the like.

  The adhesive of the present invention does not use a water-insoluble solvent, an oil pigment using a dispersant, or an oil dye for dispersion / dissolution. These deteriorate water disintegrability when used as an adhesive. Of course, the pigment ink itself is not the adhesive of the present invention.

  The water-decomposable sanitary thin paper of the present invention is superior in water-decomposability and reusability of damaged paper compared to conventional oil-based pigments, especially those using oil-based ink, by constituting the adhesive with an aqueous material. It is greatly improved.

  In addition, with regard to use in toilet paper that is assumed to be a shower toilet, unintended solubility and colorant outflow, together with the design of the base paper sheet to be described later, the content ratio of the aqueous dye to the adhesive base is 15% by weight or less Preferably, it is 10% by weight or less, and particularly preferably 2 to 10% by weight. If it is less than 2% by weight, the color becomes light and it is difficult to develop a good appearance.

  Furthermore, particularly suitable as the adhesive of the present invention is one using an aqueous dye rather than one using an aqueous pigment. Both water-based pigments and water-based dyes have advantages compared to the case of using oil-based pigments in terms of water decomposability, and there is no difference in that respect.

However, water-based dyes are excellent in the following points. First, soluble dyes are superior to insoluble pigments in terms of bleaching properties when recycling waste paper. Insoluble pigments with soluble dyes are said to be excellent in color developability, but with relatively low basis weight paper such as water-degradable sanitary thin paper, the amount of pigment applied per unit area may increase. Since it is not possible, the good color developability of the pigment is not very advantageous compared to the case of using a dye. In this regard, there is no difference even when water-based dyes are compared with oil-based inks having the highest color developability. Rather, since the pigment is not dissolved in the base material, if the pigment content per unit area is small, the color of the design emboss becomes partially mottled, which in turn affects the partial adhesion. Such a problem does not occur when a dye is used. Therefore, it is possible to form an embossed design colored in a very light color.
For this reason, in the water-decomposable sanitary thin paper of the present invention, among water-based colorants, it is preferable to use a dye rather than a pigment.

  On the other hand, the viscosity of the adhesive of the present invention is preferably 1 to 100 mpa · s, particularly 5 to 30 mpa · s.

[Regarding the base paper sheet]
The raw material pulp of the base paper sheet constituting the water-decomposable sanitary paper according to the present invention is not particularly limited. An appropriate raw material pulp can be selected and used according to the use of the water-degradable sanitary thin paper. Examples of the raw material pulp include wood pulp, non-wood pulp, synthetic pulp, and waste paper pulp. More specifically, ground pulp (GP), stone grand pulp (SGP), refiner ground pulp (RGP), and pressure type Ground pulp (PGW), thermomechanical pulp (TMP), chemithermomechanical pulp (CTMP), bleached chemithermomechanical pulp (BCTMP) and other mechanical pulp (MP), chemical mechanical pulp (CGP), semi-chemical pulp ( Chemical pulp (SCP), kraft pulp (KP) such as hardwood bleached kraft pulp (LBKP), softwood bleached kraft pulp (NBKP), soda pulp (AP), sulfite pulp (SP), dissolved pulp (DP), etc. CP), nylon, rayon, polyester, polyvinyl alcohol Synthetic pulp made from (PVA), deinked pulp (DIP), waste paper pulp such as waist pulp (WP), ground pulp (TP), cotton, flax, hemp, jute, manila hemp, ramie, etc. One or several types can be appropriately selected and used from rag pulp, straw pulp, esparto pulp, bagasse pulp, bamboo pulp, kenaf pulp, and other auxiliary pulps such as bast pulp.

  In particular, if the raw material pulp is toilet paper or tissue paper, a mixture of NBKP and LBKP is preferable. Waste paper pulp may be blended as appropriate, but in terms of texture and the like, it is preferably composed only of NBKP and LBKP. In this case, the blending ratio is NBKP: LBKP = 30: 70 to 50:50. In particular, NBKP: LBKP = 40: 60 is particularly desirable.

  Raw materials such as pulp fibers are used as a base paper through, for example, a known papermaking process, specifically, a wire part, a press part, a dryer part, a size press, a calendar part, and the like.

  In this papermaking, for example, suitable chemicals such as a dispersant, caustic soda, aqueous ammonia and other pH adjusters, antifoaming agents, preservatives, fluorescent dyes, mold release agents, water resistance agents, flow modifiers, yield improvers, etc. Can be added.

On the other hand, the base paper sheet is not limited to white, and may be light pink or blue, for example, in order to obtain the effect of clearly showing the design embossing or the effect of making the overall appearance look high-class. The thing of the color of the pulp itself which is not colored may appear.
The adjustment of the base color of the base paper sheet can be achieved by a known technique such as making paper using a papermaking raw material colored according to the technique.

[US tsubo]
On the other hand, the rice tsubo of the water-decomposable sanitary paper according to the present invention can be appropriately adjusted according to its use, but is preferably 11 to 25 g / m ^{2 for} each layer. Preferably, a 11~20g / m ^2. This is because if it is less than 11 g / m ² , it is preferable from the viewpoint of improving softness, but the strength cannot be ensured properly. On the other hand, if it exceeds 25 g / m ² , it becomes too hard and the touch is poor. This range is particularly suitable when toilet paper or tissue paper is used as a water-degradable sanitary thin paper. In addition, the US tsubo is based on the JIS P 8124 US tsubo measurement method.

[Paper thickness]
Paper thickness is 50 to 450 μm. The paper thickness also depends on the use of the water-degradable sanitary thin paper, but in the case of toilet paper, it is preferably 100 to 300 μm. The paper thickness referred to here is not the paper thickness of the base paper sheet, but the paper thickness of the water-degradable sanitary thin paper. When the paper thickness is less than 50 μm, it is preferable from the viewpoint of improving the softness, but the strength as toilet paper cannot be ensured properly. On the other hand, if it exceeds 450 μm, the toilet paper becomes too hard and the touch of the toilet paper is not only deteriorated, but also a feeling of tingling is generated during use. Note that it is not necessary to unify all the thicknesses of the base paper sheets constituting each layer.

  The paper thickness is measured using a dial thickness gauge (thickness measuring instrument) “PEACOCK G type” (manufactured by Ozaki Seisakusho) under the conditions of JIS P8111. Specifically, confirm that there is no dust, dust, etc. between the plunger and the measuring table, lower the plunger on the measuring table, move the memory of the dial thickness gauge to adjust the zero point, and then Then, raise the plunger and place a sample (eg, toilet paper) on the test table, slowly lower the plunger and read the gauge at that time. At this time, only the plunger is placed. The paper thickness is an average value obtained by performing measurement 10 times.

  The tensile strength of the water-decomposable sanitary thin paper according to the present invention is performed according to the tensile test method of JIS P8113. Among them, it is cut into a width of 25 mm in the vertical direction and the horizontal direction under the standard conditions defined in JIS P8111.

[Water disintegration]
As for the water decomposability of the water decomposable sanitary thin paper according to the present invention, it is possible to secure a result of at least 80 seconds in the test method for ease of loosening defined by JIS P 4501. Usually, if it exceeds 80 seconds, the water disintegration property is slow, and there is a possibility that the drain pipe is clogged when discarded in a flush toilet, for example. In particular, with the water-decomposable sanitary thin paper according to the present invention, it is possible to achieve 35 seconds or less, which is difficult with the use of pigments.

[Ply peel strength]
Bonded with an adhesive. The ply peel strength [cN / 50 mm] of the base paper sheet is preferably 5 to 100 cN / 50 mm. The reason why the lower limit is defined as 5 cN / 50 mm is that when the thickness is less than 5 cN / 50 mm, the base paper sheets S1 and S2 cannot be properly bonded to each other. Moreover, the reason why the upper limit is defined as 100 cN / 50 mm is that when it exceeds 100 cN / 50 mm, it becomes too hard as a water-degradable sanitary thin paper, and the touch is deteriorated. The ply peel strength is measured according to the tensile test method of JIS P 8113. Among them, it shall be cut into a width of 50 mm in the vertical direction under the standard conditions specified in JIS P8111. After cutting, the sample is peeled in the vertical direction, and the peeled load cell (TG200N, manufactured by Minebea) is fixed to the upper gripping tool and the other to the lower gripping tool. The interval is 8 cm. Next, the film is pulled at a rate of 100 mm / min in the vertical direction and further peeled by 5 cm, and the strength at that time is measured.

Next, the results of evaluating the water decomposability, bleachability and appearance of Examples, Comparative Examples and Conventional Examples of the present invention will be described.
Examples of the present invention use a cellulosic water-based adhesive (JW-5612 manufactured by Sekisui Fuller Co., Ltd.) as an adhesive and an anionic liquid dye (Kayafect Turquoise GT Liquid manufactured by Nippon Kayaku Co., Ltd.) as an aqueous dye. What was mixed in the medium ratio was used.

Further, two thin paper sheets were stacked (2 plies), and the embossed convex portions were bonded to each other with the adhesive to form a sample.
The density of the pattern embossing in the sample was 16 pieces / cm ^2, and the coating amount of the adhesive was 0.05 g / m ² . The thin paper was composed of 100% virgin pulp (LBKP: NBKP = 3: 7).

A comparative example uses the adhesive which mixed the oil-based pigment ink (The coloring component which mainly has a copper phthalocyanine is disperse | distributed in the hydrophobic organic solvent) in the ratio in the table | surface in the cellulose adhesive base, The raw material of the thin paper was the same as in the example.
The conventional example uses an oil-based pigment ink (in which a coloring component mainly composed of copper phthalocyanine is dispersed in a hydrophobic organic solvent) as an adhesive.

In these examples, comparative examples, and conventional examples, the basis weight of the thin paper and the ratio of the dye or the pigment to the adhesive base were changed, and water decomposability, bleachability and appearance were evaluated for each. The composition of basis weight and the results of evaluation in each example are as shown in Table 1 below.
In addition, the water disintegration property was measured based on a test method for ease of loosening defined by JIS P 4501. The score was evaluated in three stages: “Inferior to conventional example: −1”, “Same as conventional example: ± 0”, and “Excellent than conventional example: +1”. In the table, those with a score of + are indicated by ◎, those with ± 0 are indicated by ○, and those with − are indicated by ×.
The bleaching property was subjected to a bleaching operation using hypochlorous acid after hydrolyzing for a predetermined time, and the bleaching property was observed.
The appearance and feeling of use were made by comparison with a conventional example. Scores were made in three stages: “Inferior to conventional example: −1”, “Similar to conventional example: ± 0”, “Excellent than conventional example: +1”, and evaluated by the total of 20 subjects. In the table, those with a score of + are indicated by ◎, those with ± 0 are indicated by ○, and those with − are indicated by ×. In addition, in the test subjects, the appearance was evaluated comprehensively from the viewpoints of the cosmetics, color developability, and feeling of use, and the touch and softness.

From the results shown in Table 1, the examples of the present invention are much better in terms of water disintegration than the comparative examples and the conventional examples. In particular, the basis weight of 25 g / m ² was less than 35 seconds, and the result of hydrolysis in about half the time of the conventional example using the ink pigment was obtained.
Furthermore, in the examples, although the amount of the colorant used relative to the base is low, the evaluation is higher than that of the conventional example and the comparative example in terms of appearance. It is presumed that a difference between a pigment that exhibits a coloring function by dispersion in the base and a dye that exhibits a coloring function by dissolving in the base appears.
In addition, the usability was not different from the conventional example in the range of the rice tsubo in the examples, or more results were obtained.
Furthermore, as for the bleaching property, in the examples, because it was excellent in water decomposability and fibers etc. were easily dispersed, it could be bleached with a small amount of bleach (hypochlorous acid), whereas the comparative example and the conventional example were It was observed that the bonded part remained in a ball shape and was not sufficiently bleached in that part. In calculation, if the water disintegrability of the examples of the present invention is taken into consideration, it is considered that the bleaching operation can be performed even at a low concentration of 1/50 to 1/10 times the conventional one.
From the evaluation of the above examples, comparative examples, and conventional examples, according to the present invention, a sanitary thin paper having a colored embossed pattern, extremely excellent in design properties and having no difficulty in water disintegration is provided.

  The thin paper of the present invention can be used as a water-decomposable sanitary thin paper used for sanitary applications, in particular, as toilet paper or tissue paper.

Claims (6)

In the water-degradable sanitary thin paper that is made by stacking two or more thin papers,
At least one thin paper has an emboss, and is adhered to an adjacent thin paper by an adhesive applied to the top of the convex portion of the emboss,
The water-degradable sanitary thin paper, wherein the adhesive used for adhering the thin papers is obtained by coloring an aqueous adhesive base with an aqueous colorant.   The water-degradable sanitary thin paper according to claim 1, wherein the aqueous adhesive base is a cellulosic adhesive. The water-decomposable sanitary thin paper according to claim 1 or 2, wherein the water-decomposable sanitary thin paper has a paper thickness of 100 to 450 µm and a rice basis of each thin paper is 11 to 25 g / m ² .   The water-decomposable sanitary thin paper according to any one of claims 1 to 3, wherein a dry tensile strength in the longitudinal direction per sheet of the thin paper is 100 to 800 cN / 25 mm, and a dry tensile strength in the transverse direction is 50 to 350 cN / 25 mm. .   The water-degradable sanitary thin paper according to any one of claims 1 to 4, wherein the aqueous colorant is an aqueous dye, and the aqueous adhesive base contains 10% by weight or less of the aqueous dye. The water-decomposable sanitary thin paper according to any one of claims 1 to 5, wherein the aqueous adhesive base is polyvinyl alcohol or carboxymethyl cellulose, and the coating amount is 0.001 to 0.02 g / m ² in terms of solid content.