JP2008272267A - Toilet paper and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide toilet paper attaining the both of prevention of the permeation of water content to a back side and water solubility. <P>SOLUTION: This toilet paper consists of 3 plies, the respective outer layers 11 and 12 contain neither size agent nor water repellent substantially, and an intermediate layer 20 contains alkyl ketene dimer of 0.01-0.2 wt.% in solid content weight relative to pulp dry weight. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to toilet paper and a method for manufacturing the toilet paper. In particular, the present invention relates to a technique for obtaining toilet paper that is excellent in resistance to see-through used in a shower toilet.

In recent years, with the spread of shower toilets, it has become an issue to further prevent moisture from getting through.
Conventionally, the technique for preventing the breakthrough has been set to three plies, and for each ply, the pulp density has been increased mainly by pulverizing the pulp fibers to increase the pulp density.
However, it has been found that clogging problems occur in the toilet drainage system.
On the other hand, Patent Document 1 discloses a three-ply tissue, in which at least one ply has a water repellent (size agent). As an example, FIG. Treatment with an agent). In this example, as shown in FIG. 6, it is assumed that the paper material is ejected from the head box into three layers, and it is not a superposition ply. However, there is no consideration for water disintegration, and there is no disclosure that water disintegration differs depending on the type of sizing agent.
JP-T-2002-519533

  The main problem to be solved by the present invention is to provide a toilet paper that is compatible with prevention of moisture penetration and water disintegration. Another problem is to make the toilet paper bulky and soft. Other issues will become clear from the description below.

The present invention that has solved this problem is as follows.
[Invention of Claim 1]
In toilet paper consisting of 3 plies,
Each outer layer contains substantially no sizing agent or water repellent, and the intermediate layer contains an alkyl ketene dimer in a solid content of 0.01 to 0.2% by weight based on the dry weight of the pulp. Toilet paper.

(Function and effect)
Moisture penetrates through the outer layer. Permeated moisture is hydrophobic because the intermediate layer having an alkyl ketene dimer is hydrophobic, preventing penetration of moisture and preventing back-through through the other outer layer (not always meaning no back-through, normal (It means that it is possible to suppress or prevent the showthrough to the extent that there is no practical problem with respect to the moisture content).
And since an outer layer does not contain a sizing agent or a water repellent substantially, it becomes a thing with a favorable moisture absorption.
Further, the intermediate layer has an alkyl ketene dimer, and its content is 0.01 to 0.2% by weight in terms of solid content with respect to the dry weight of pulp. More preferably, it is 0.05 to 0.15% by weight. Various types of sizing agents are known. However, as shown in Examples and Comparative Examples described later, it has been clarified that sizing agents other than the present invention have a problem in water decomposability. Therefore, according to the present invention, both prevention of moisture penetration and water disintegration are compatible, and this finding is completely unexpected. The principle is not clear.
In addition, when a pattern or the like is printed on the intermediate layer with an oil-based ink and is visible through the outer layer, the intermediate layer contains a lipophilic alkyl ketene dimer, so even a small amount of oil-based ink is good for the intermediate layer. Since it penetrates and the amount of oil-based ink to be used can be reduced, the ink curing volume is reduced, and the softness as toilet paper is increased.

[Invention of Claim 2]
3-ply total basis weight is 30 to 75 g / m ^2, respectively the outer layer 10 to 25 g / m ^2, an intermediate layer according to claim 1, wherein a 10 to 25 g / m ² of toilet paper.

(Function and effect)
With this US tsubo configuration, the water absorbability (absorption amount), moisture back-through prevention and water disintegration are excellent.

[Invention of Claim 3]
The toilet paper according to claim 1 or 2, wherein each ply is made by paper and the plies are overlapped without being bonded.

(Function and effect)
When each ply is made by paper and the plies are superposed without being bonded (including forms such as simply superposed and partially joined by embossing), for example, Compared with the case where the paper stock is jetted from the head box to form three layers, the back-through prevention effect is high and the water disintegration property is also high. This is because moisture tends to stay between the outer layer and the intermediate layer, so that the effect of preventing see-through is enhanced, and when it is flushed to the toilet, moisture quickly enters between the layers and the water disintegration is improved. It is done. Furthermore, it also gives a feeling of bulk.

[Invention of Claim 4]
The toilet paper according to any one of claims 1 to 3, wherein each outer layer has a water absorption rate (TAPPI No. 32: 2000) of 2 to 60 seconds.

(Function and effect)
When the water absorption speed is within this range, the water absorption and water disintegration properties are good, and there is no breakage during wiping.

[Invention of Claim 5]
When manufacturing toilet paper consisting of 3 plies,
(1) A step of papermaking a pulp slurry having a Canadian freeness (csf) of 570 to 610 ml, and obtaining first and second plies for an outer layer substantially containing no sizing agent or water repellent,
(2) An intermediate layer ply containing an alkyl ketene dimer in a pulp slurry having a Canadian freeness (csf) of 550 to 600 ml and a solid content of 0.01 to 0.2% by weight with respect to the dry weight of the pulp is obtained. Process,
(3) A step of superimposing the first ply and the second ply on each outer surface of the intermediate layer ply without bonding each ply;
A method for producing toilet paper, comprising:

(Function and effect)
Since both the outer layer and the intermediate layer are not beaten by pulp fiber fibrillation to increase the pulp density, the toilet paper is bulky and flexible. Further, the above-described effects described with respect to claim 3 are also achieved.

  As described above, if necessary, according to the present invention, it is possible to provide toilet paper that is compatible with prevention of moisture penetration and water disintegration. In addition, the toilet paper can be made bulky and soft.

Next, an embodiment of the present invention will be described.
As schematically shown in FIG. 1, the toilet paper of the present invention is composed of three plies of a first ply 11, a second ply 12, and an intermediate layer 20 forming an outer layer. Each outer layer 11 and 12 is mainly composed of pulp fibers that do not substantially contain a sizing agent or water repellent. In the intermediate layer 20, the pulp fiber contains 0.01 to 0.2% by weight of an alkyl ketene dimer (referred to as “AKD”) based on the dry weight with respect to the pulp.

If the AKD is small, the prevention of the back-through of the present invention is not sufficient. On the other hand, if it is excessively large, the water may be repelled without passing water.
The present inventors have used many water repellents and sizing agents, but have found that AKD has what satisfies the required water decomposability. In addition, the effect of preventing the breakthrough is high. By adding AKD, the intermediate layer becomes hydrophobic.
As a method for adding AKD, it is desirable to add it to the pulp fiber slurry at the paper making stage. AKD may be spray-coated on the surface of the pulp fiber layer, but it tends to reduce water disintegration.
Further, a pattern or the like can be printed on the intermediate layer 20 with oil-based ink so that it can be seen through the outer layer.

Three-ply total weight (measured in accordance with JIS P 8124 under the conditions specified in JIS P 8111) is 30 to 75 g / m ² , each outer layer 11 and 12 is 10 to 25 g / m ² , respectively. layer 20 is preferably a 10 to 25 g / m ^2. If the outer layers 11 and 12 have a low rice floor, the water absorption (absorption amount) is not sufficient, and if the intermediate layer 20 has a low rice floor, a cause of back-through is caused. At an excessively high US tsubo, it becomes thicker than necessary, causing clogging of piping.
The paper thickness (measured by using Ozaki Dial Thickness Gauge “PEACOCK G type” under the conditions of JIS P 8111) is preferably 110 to 205 μm per ply.
It is desirable that each ply is made by paper and the plies are overlapped without being bonded. In addition to simply superposed ones, they may be partially joined by embossing. When emboss bonding is used, there is an advantage that bulkiness can be imparted.

However, it does not exclude joining each ply in the form of dots, for example, with a water-decomposable adhesive component such as PVA (polyvinyl alcohol) or CMC (carboxymethylcellulose). Further, as disclosed in Japanese Patent Application Laid-Open No. 2007-75510 previously proposed by the present applicant, a coloring adhesive containing a pigment is attached to the convex portion of the embossing roll so that the design such as a pattern can be visually recognized. It is also possible to carry out emboss bonding. Even if this type of adhesive is used, there is no effect on water disintegration.
It is desirable that the water absorption rate (TAPPI No. 32: 2000) of each outer layer is 2 to 60 seconds. If the water absorption rate is slow, the water absorption is not sufficient. On the other hand, if it is too fast, it will break when wiping.

  In the production, (1) a pulp slurry having a Canadian freeness (csf) of 570 to 610 ml is made, and first and second plies 11 and 12 for the outer layer substantially free of sizing agent or water repellent are obtained. Step (2) An intermediate layer ply containing alkyl ketene dimer in a pulp slurry having a Canadian freeness (csf) of 550 to 600 ml in an amount of 0.01 to 0.2% by weight based on the dry weight of the pulp. 20, and (3) the first ply and the second plies 11 and 12 are superposed on each outer surface of the intermediate layer ply 20 without being bonded to each other.

  As the pulp fiber in the present invention, for example, wood pulp, non-wood pulp, synthetic pulp, waste paper pulp, and the like, more specifically, groundwood pulp (GP), stone grand pulp (SGP), refiner ground pulp (RGP). ), Pressurized groundwood pulp (PGW), thermomechanical pulp (TMP), chemithermomechanical pulp (CTMP), bleached chemithermomechanical pulp (BCTMP) and other mechanical pulp (MP), chemical mechanical pulp (CGP), semi Kraft pulp (KP) such as chemical pulp (SCP), hardwood bleached kraft pulp (LBKP), softwood bleached kraft pulp (NBKP), soda pulp (AP), sulfite pulp (SP), dissolved pulp (DP), etc. Chemical pulp (CP), nylon, rayon, polyester, polyester Synthetic pulp made from vinyl alcohol (PVA), deinked pulp (DIP), waste pulp such as waist pulp (WP), ground pulp (TP), cotton, flax, hemp, jute, manila hemp, ramie, etc. One or several kinds of rag pulp, straw pulp, esparto pulp, bagasse pulp, bamboo pulp, kenaf pulp, and other auxiliary pulps such as bast pulp can be selected and used. This is preferably wood pulp, and it is desirable to use hardwood bleached kraft pulp (LBKP) or softwood bleached kraft pulp (NBKP). It is desirable that it is 100% wood pulp that does not contain waste paper pulp.

  In each layer or any one of the layers, if necessary, an appropriate agent such as a dispersant, caustic soda, a pH adjuster, an antifoaming agent, an antiseptic, a fluorescent dye, a mold release agent, a water resistant agent, a flow modifier, a yield improver, etc. Chemicals can be added.

Next, effects of the present invention will be clarified by examples and comparative examples.
Using hardwood bleached kraft pulp (LBKP) and softwood bleached kraft pulp (NBKP) as a paper stock with a pulp slurry having a weight ratio of 7/3, each layer was obtained, and these three plies were overlapped for the experiment. The superposition pressure is 4.2 kgf, and pressure is applied for 5 minutes with a flat press.
When the test of the item shown in Table 2 was performed on the conditions shown in Table 1, the result shown in Table 2 was obtained. “Blank” means that no additive is added to the intermediate layer. The drug A is a cationic substance mainly composed of a fatty acid derivative, and is considered to have a low size effect. The drug B is a cationic compound obtained by adding a fatty acid derivative exhibiting a higher size effect to the drug A. Chemical C is a nonionic fatty acid derivative (which also has a surfactant effect) as a main component, and Drug D is a cationic fatty acid derivative as a main component which has a flexible effect and a size effect (model number “ PT8104 "), both of which are manufactured by Seiko PMC (however, not commercial products but prototypes), and prototypes were repeated while selecting from the viewpoint of size effect.

The test method is as follows.
“Water-disintegration test”: Executed based on JIS P 4501.
“Penetration number test”: 1 ml of water is spread on a 300 mm × 400 mm plastic plate so as to spread over the entire surface. A sheet of 10 plies of 3 ply toilet paper with a size of 114 mm x 114 mm is placed on the water, and then a weight of 650 g is placed on the top and removed for about 1 second. Count the number of penetrated. This is done 5 times and an average value is taken.
“Drop test”: The test equipment uses the actual toilet equipment shown in FIG. 2 (toilet bowl: CS22BP manufactured by Totoki Co., Ltd., tank: SH32BAK manufactured by Totoki Co., Ltd.). That is, a circular acrylic drainage pipe (diameter 75 mm) 32 made to be visible from the outside having a drop length of 70 cm, a horizontal length of 20 m and a gradient of 1% is connected to the toilet 30, and drained by a drain cock 31 in the tank. Use what you want. In addition, since the distance from a general house to a sewage tank is 20 m and the road slope is 1% or 2%, the length of the drain pipe in this test was set to 20 m and the slope was set to 1%. In the test, toilet paper (3-ply product) is cut to a length of 1.1 m (width 114 mm) and folded so as to be a square with a side of 114 mm according to the width. Three of these same ones (3.3 m) are put into the toilet bowl at a time and water is flowed once (8 liters of washing water). This is set as one set, and is repeated at intervals of 60 seconds, and the number of times that the water must be poured before the fourth set flows 20 m is measured. Washing water having a pH of 7.5 and an electrical conductivity of 100 mS / m was used.
“Dry cut length”: Measured based on JIS P 8113.
“Wet line break length”: Measured according to JIS P 8135.
“Softness”: According to the handle ohm method (JIS L-1096 E method).

It is sectional drawing which shows typically the structure of the toilet paper of this invention. It is explanatory drawing of a drop test facility.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... 1st ply (outer layer), 12 ... 2nd ply (outer layer), 20 ... intermediate layer, 30 ... toilet bowl, 31 ... drain cock, 32 ... circular water pipe.

Claims (5)

In toilet paper consisting of 3 plies,
Each outer layer contains substantially no sizing agent or water repellent, and the intermediate layer contains an alkyl ketene dimer in a solid content of 0.01 to 0.2% by weight based on the dry weight of the pulp. Toilet paper. 3-ply total basis weight is 30 to 75 g / m ^2, respectively the outer layer 10 to 25 g / m ^2, an intermediate layer according to claim 1, wherein a 10 to 25 g / m ² of toilet paper.   The toilet paper according to claim 1 or 2, wherein each ply is made by paper and the plies are overlapped without being bonded.   The toilet paper according to any one of claims 1 to 3, wherein the water absorption speed (TAPPI No. 32: 2000) of each outer layer is 2 to 60 seconds. When manufacturing toilet paper consisting of 3 plies,
(1) A step of papermaking a pulp slurry having a Canadian freeness (csf) of 570 to 610 ml, and obtaining first and second plies for an outer layer substantially containing no sizing agent or water repellent,
(2) An intermediate layer ply containing an alkyl ketene dimer in a pulp slurry having a Canadian freeness (csf) of 550 to 600 ml and a solid content of 0.01 to 0.2% by weight with respect to the dry weight of the pulp is obtained. Process,
(3) A step of superimposing the first ply and the second ply on each outer surface of the intermediate layer ply without bonding each ply;
A method for producing toilet paper, comprising:

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