WO2016031749A1

WO2016031749A1 - Sanitary thin paper and absorbent article using same

Info

Publication number: WO2016031749A1
Application number: PCT/JP2015/073669
Authority: WO
Inventors: かおり山邊; 金野　晴男; 村田　剛; 克水口
Original assignee: 日本製紙株式会社; 日本製紙クレシア株式会社
Priority date: 2014-08-29
Filing date: 2015-08-24
Publication date: 2016-03-03
Also published as: JPWO2016031749A1; CN106715798A; KR102151693B1; CN106715798B; KR20170035940A; JP6681335B2; KR20190130052A

Abstract

[Problem] To provide a sanitary thin paper having excellent deodorizing function and an absorbent article using same. [Solution] Provided is a sanitary thin paper that contains metal ion-containing cellulose fibers obtained by incorporating ions of at least one type of metal element, selected from among the group consisting of Ag, Au, Pt, Pd, Ni, Mn, Fe, Ti, Al, Zn and Cu, in oxidized cellulose fibers having carboxyl groups or carboxylate groups on the surface thereof.

Description

Sanitary tissue paper and absorbent articles using the same

The present invention relates to a sanitary thin paper having a deodorizing function and an absorbent article using the sanitary thin paper.

種々 Various deodorizing functions are given to sanitary thin paper such as tissue paper, toilet paper, and hand towels. For example, techniques for applying a chemical solution having a deodorizing function to base paper are disclosed (Patent Documents 1 and 2). Further, a technique is disclosed in which zeolite is supported inside cellulose fibers and Ag, Cu, etc. are supported in the zeolite, and paper is made from the cellulose fibers to impart a deodorizing function to the paper itself (trade name). Cellgaia (registered trademark), Patent Document 3).

In addition, recently, there is a very high need for imparting a deodorizing function to absorbent articles such as disposable diapers, light incontinence products and pet sheets. As such an absorbent article, a configuration in which an absorbent core is wrapped with a carrier sheet (core wrap sheet) coated with a deodorant and the whole is wrapped with an outer layer sheet is disclosed (Patent Document 4). And the technique which made the paper of the cellulose fiber of patent document 3 and formed an odor control sheet, and arrange | positioned between the absorption core and back sheet | seat of an absorbent article is disclosed (patent document 5).

JP 2003-325372 A Special table 2010-511806 gazette Japanese Patent No. 4149066 JP 2004-89322 A JP 2008-48775 A

However, when a chemical solution having a deodorizing function is applied to the base paper, the bond between the pulp fibers is weakened, so that paper dust is generated and the original strength, water absorption, texture, etc. of the sanitary thin paper are impaired. May end up. Furthermore, there is a possibility that the chemical solution released or eluted from the sanitary thin paper may irritate the skin.
On the other hand, in the case of the technique described in Patent Document 3, since zeolite is physically supported in cellulose fibers, there is a problem that the zeolite is easily dropped and the deodorizing function is not sufficient. Further, in the case of the technique described in Patent Document 3, the fiber is deformed and damaged due to a reaction when zeolite or the like is supported on the cellulose fiber, resulting in shortening. For this reason, when a core wrap sheet is produced by making paper from this cellulose fiber, the bonds between the fibers are weakened, and the core wrap sheet is likely to be twisted or torn like the above.
Therefore, an object of this invention is to provide the sanitary thin paper which has the outstanding deodorizing function, and an absorbent article using the same.

In order to solve the above-mentioned problems, the sanitary thin paper of the present invention is made of Ag, Au, Pt, Pd, Ni, Mn, Fe, Ti, Al, Zn, and oxidized cellulose fibers having a carboxyl group or a carboxylate group on the surface. Metal ion-containing cellulose fibers containing ions of one or more metal elements selected from the group of Cu are included.

The content of the metal ions with respect to the oxidized cellulose fiber is preferably 10 to 60 mg / g, and particularly preferably 15 to 50 mg / g.

The absorbent article of the present invention includes an absorbent core, a core wrap sheet that covers or is laminated on the absorbent core, and a liquid-permeable outer layer sheet that covers at least one surface of the core wrap sheet. The core wrap sheet is the above-mentioned sanitary thin paper.

According to this invention, a sanitary thin paper having an excellent deodorizing function and an absorbent article using the sanitary thin paper can be obtained.

It is a perspective view which shows the external appearance of the absorbent article which concerns on embodiment of this invention. FIG. 2 is a cross-sectional view taken along line AA in FIG.

The sanitary thin paper according to the embodiment of the present invention is selected from the group of Ag, Au, Pt, Pd, Mn, Fe, Ti, Al, Zn and Cu with respect to the oxidized cellulose fiber having a carboxyl group or a carboxylate group on the surface. Metal ion-containing cellulose fibers containing ions of one or more metal elements.
This metal ion-containing cellulose fiber can be obtained by bringing a metal compound aqueous solution into contact with an oxidized cellulose fiber having a carboxyl group or a carboxylate group introduced on the surface of the cellulose fiber. In addition, as a method for producing sanitary thin paper according to an embodiment of the present invention, in addition to a method of bringing the metal compound aqueous solution into contact with a sheet made of a raw material containing oxidized cellulose fibers, metal oxides are previously contained in oxidized cellulose fibers, A method for producing a raw material containing the metal ion-containing cellulose fiber can be exemplified.

The oxidized cellulose fiber can be produced by oxidizing cellulose fiber such as wood pulp using an N-oxyl compound as a catalyst. By this oxidation reaction, the primary hydroxyl group at the C6 position of the glucopyranose ring on the cellulose surface is selectively oxidized, and an oxidized cellulose fiber having a carboxyl group or a carboxylate group on the surface is obtained. The raw material cellulose is preferably natural cellulose. The oxidation reaction is preferably performed in water. Although the density | concentration of the cellulose fiber in reaction is not specifically limited, 5 mass% or less is preferable. The amount of the N-oxyl compound may be about 0.1 to 4 mmol / L with respect to the reaction system. A known cooxidant may be used for the reaction. Examples of the co-oxidant include dihalous acid or a salt thereof. The amount of the co-oxidant is preferably 1 to 40 mol with respect to 1 mol of the N-oxyl compound.
The reaction temperature is preferably 4 to 40 ° C., more preferably room temperature. The pH of the reaction system is preferably 8-11. The degree of oxidation can be appropriately adjusted depending on the reaction time, the amount of N-oxyl compound, and the like.
The oxidized cellulose fiber thus obtained has acid groups on the surface and almost no acid groups inside. This is presumably because the cellulose fiber is crystalline, so that the oxidant hardly diffuses into the fiber.

The carboxyl group refers to a group represented by —COOH, and the carboxylate group refers to a group represented by —COO 2 ^— . The counter ion of the carboxylate group in producing the oxidized cellulose fiber is not particularly limited. Then, metal ions to be described later are ion-bonded to the carboxylate group replacing the counter ions. In addition, the carboxyl group seems to coordinate with a metal ion such as a copper ion. The carboxyl group or carboxylate group is also referred to as an “acid group”.
The content of acid groups can be measured by the method disclosed in paragraph 0021 of JP-A-2008-001728. That is, 60 mL of a 0.5 to 1 mass% slurry is prepared using a precisely weighed dry cellulose sample, and the pH is adjusted to about 2.5 with a 0.1 mol / L hydrochloric acid aqueous solution. Then, 0.05 mol / L sodium hydroxide aqueous solution is dripped and electrical conductivity measurement is performed. The measurement is continued until the pH is about 11. From the amount (V) of sodium hydroxide consumed until the neutralization step of the weak acid, where the change in electrical conductivity shows a gradual change, the acid group amount X1 is determined using the following equation.
X1 (mmol / g) = V (mL) × 0.05 / mass of cellulose (g)

The amount of acid groups in the cellulose fiber is preferably 0.2 to 2.2 mmol / g. When the amount of acid groups is less than 0.2 mmol / g, the amount of metal ions present on the surface of the cellulose fiber is not sufficient, and the deodorizing function may be inferior. If the amount of acid groups exceeds 2.2 mmol / g, the freeness of the sanitary thin paper may be deteriorated and the dehydration load may be increased.

Next, an aqueous solution containing the metal compound is brought into contact with the oxidized cellulose fiber, and metal ions derived from the metal compound form an ionic bond with the carboxylate group. The carboxyl group is ionized and ionically bonds with the metal ion via the carboxylate group, or is coordinated with the metal ion as described above.
The metal compound aqueous solution is an aqueous solution of a metal salt. Examples of metal salts include complexes (complex ions), halides, nitrates, sulfates, and acetates. The metal salt is preferably water-soluble.
With regard to the method of contacting the metal compound, a cellulose fiber dispersion prepared in advance and a metal compound aqueous solution may be mixed, and a dispersion containing cellulose fibers is applied onto a substrate to form a film, and the metal compound is applied to the film. An aqueous solution may be added and impregnated. At this time, the film may remain fixed on the substrate or may be peeled from the substrate.
The concentration of the aqueous metal compound solution is not particularly limited, but is preferably 0.2 to 2.2 mmol and more preferably 0.4 to 1.8 mmol with respect to 1 g of cellulose fiber.
You may adjust suitably the time which a metal compound is made to contact. The temperature at the time of contact is not particularly limited, but 20 to 40 ° C. is preferable. Further, the pH of the liquid at the time of contacting is not particularly limited. However, when the pH is low, it becomes difficult for metal ions to bind to the carboxyl group, so 7 to 13 is preferable and pH 8 to 12 is particularly preferable.

The fact that the oxidized cellulose fiber contains (coordinates) metal ions can be confirmed by a scanning electron microscopic image and ICP emission analysis of the extract with a strong acid. That is, the presence of metal ions cannot be confirmed in the scanning electron microscope image, while it can be confirmed that the metal ions are contained in the ICP emission analysis. On the other hand, for example, when the metal is reduced from ions and exists as metal particles, the metal particles can be confirmed by a scanning electron microscope image, so the presence or absence of metal ions can be determined. The presence or absence of metal ions can also be determined by scanning electron microscope images and element mapping. That is, metal ions cannot be confirmed in a scanning electron microscope image, but the presence of metal ions can be confirmed by elemental mapping.
By using one or more ions selected from the group consisting of Ag and Cu as metal ions, an antibacterial function is imparted. On the other hand, metal particles do not have to be bonded to all of the acid groups of the cellulose fiber, and the remaining acid groups can neutralize odorous components such as ammonia and exhibit a deodorizing function.

Sanitary thin paper is made from papermaking raw materials containing cellulose fibers. As a papermaking raw material other than the cellulose fiber, for example, virgin pulp such as softwood pulp (NBKP) or hardwood pulp (LBKP), or used paper pulp regenerated from used paper can be used. These pulps are appropriately blended in predetermined types and blending ratios according to the required quality of sanitary paper. Various chemicals may be added (internally added) to the papermaking raw material for the required quality and stable operation. These chemicals include softeners, bulking agents, dyes, dispersants, wet paper strength enhancers, and drying agents. Examples thereof include paper strength agents, drainage improvers, pitch control agents, yield improvers, and the like.
The content ratio of the metal ion-containing cellulose fibers in the sanitary thin paper is preferably 3 to 30 wt%, and more preferably 5 to 15 wt%.
When the content of the metal ion-containing cellulose fiber is less than 3 wt%, the amount of metal particles present on the surface of the cellulose fiber is not sufficient, and the deodorizing function may be inferior. The sanitary thin paper may be composed only of the metal ion-containing cellulose fibers, but the dehydration load during paper making may increase.

The basis weight of the obtained sanitary thin paper can be set to 7 to 40 g / m ² , for example. Further, as the strength of the sanitary thin paper, the GMT value {(DMD × DCD) ^1/2 } can be set to 60 to 420 (N / m).
DMD and DCD are the tensile strengths in the MD direction and CD direction when drying sanitary thin paper, respectively, and are measured according to JIS P8113. However, the sample width at the time of measurement is 25 mm, and the unit of DMD and DCD is “N / m”.

The sanitary paper according to the embodiment of the present invention can be manufactured by a known papermaking method. First, a papermaking raw material obtained by appropriately mixing metal ion-containing cellulose fibers (or oxidized cellulose fibers before containing metal ions) and pulp is supplied from a raw material tank, and further diluted with white water to prepare a paper stock. . This debris is degassed for screening and sent to the stock inlet with a fan pump. The stock inlet supplies paper with a proper concentration, speed, and angle over the entire wire width of the paper machine, with a uniform, floc-free (small lump), and well-dispersed fiber so as not to cause flow streaks. To do. As the stock inlet, there are a head box, a pressurization type, a hydraulic type, etc. which are installed in a high place with the atmosphere open, and any of them may be adopted. Then, a stock is jetted from the stock inlet between the wire and the felt to form a sheet (web, wet paper) on the felt.

The web formed between the wire and the felt is closely transferred to the Yankee dryer by a pressure roll. Next, the web is dried by a Yankee dryer and a Yankee dryer hood, peeled off from the Yankee dryer while being creped by a creping doctor, and wound on a reel via a reel drum. A Yankee dryer is a drum made of cast iron or cast steel for drying a web, and its outer diameter is generally 2.4 to 6 m.
Here, creping is a method in which a paper is mechanically compressed in the longitudinal direction (machine traveling direction) to form a wavy wrinkle called crepe, and the bulk (feeling of bulk), softness, water absorption on sanitary paper. Properties, surface smoothness, aesthetics (crepe shape) and the like. Then, a crepe is formed by the creping doctor due to the speed difference between the Yankee dryer and the reel (reel speed ≦ yankee dryer speed). Although the crepe characteristics depend on the speed difference, if the basis weight of the base paper on the Yankee dryer is 7 to 40 g / m ² , the basis weight on the reel is approximately 9 to 50 g / m ² . It becomes larger than the above basis weight.
The crepe rate based on the speed difference between the Yankee dryer and the reel is defined by the following equation.
Crepe rate (%) = 100 x (Yankee dryer speed (m / min)-reel speed (m / min)) ÷ reel speed (m / min)
The quality of the crepe and the operability of the creping are substantially determined by the crepe rate. In the present invention, the crepe rate is preferably in the range of 10 to 50%.

Next, the absorbent article which concerns on embodiment of this invention is demonstrated.
FIG. 1 is an external view of an absorbent article (pants-type paper diaper) 200 according to the first embodiment of the present invention. The absorbent article 200 includes a water absorbent article main body 20 having water absorption, and an exterior body 100 that holds the water absorbent article main body 20 inside and forms a pants shape.
The exterior body 100 can be made of a nonwoven fabric made of a thermoplastic resin such as polypropylene, polyester, or polyethylene and manufactured by a spunbond or air-through manufacturing method. The exterior body 100 is preferably configured by laminating two or more sheets having at least an exterior sheet and an interior sheet.
The water-absorbent article main body 20 is elongated, the width near the center in the longitudinal direction is slightly narrower, and is disposed between the crotch of the absorbent article 200.

FIG. 2 is a cross-sectional view of the water absorbent article main body 20 taken along the line AA in FIG. The water absorbent article main body 20 includes a liquid-permeable hydrophilic surface sheet (top sheet, outer layer sheet) 2 that forms a body contact side surface (upper surface in FIG. 2), a liquid-impermeable back sheet 6, and a hydrophilic It arrange | positions between the surface sheet 2 and the backsheet 6, and is comprised including the

absorption cores

4a and 4b which have a highly water-absorbent resin and an adhesive agent. The

absorbent cores

4a and 4b are covered with

core wrap sheets

10a and 10b, respectively. Further, both side portions of the water absorbent article main body portion 20 stand up as a three-dimensional gather 30 composed of a water-repellent side sheet to prevent side leakage of urine and the like.
In the present embodiment, the

absorbent cores

4a and 4b respectively covered with the

core wrap sheets

10a and 10b are laminated so that the absorbent core 4a faces the hydrophilic surface sheet 2 side, and the width of the absorbent core 4a. The width of the absorbent core 4b is about ½ compared to FIG.
One absorbent core and one core wrap sheet for wrapping the absorbent core may be provided for each water absorbent article main body 20.

The hydrophilic surface sheet 2 is made of a non-woven fabric and comes into contact with the wearer's skin. As the hydrophilic surface sheet 2, an air-through nonwoven fabric, a point bond nonwoven fabric, a spunbond nonwoven fabric, a spunlace nonwoven fabric, or the like made of a synthetic fiber such as polypropylene, polyethylene, or polyester can be used. In particular, an air-through nonwoven fabric with a small liquid return amount is suitable.
The back sheet 6 only needs to be formed from a liquid-impermeable material having a waterproof property so that liquid or the like held in the water-absorbent article main body 20 does not leak into the underwear, such as a breathable polyethylene film. A thin plastic film. Moreover, a moisture-permeable film may be used as the back sheet 6 to reduce stuffiness.

The

absorbent cores

4a and 4b can be formed by mixing hydrophilic fibers (fluff) such as wood fluff pulp and particles of super absorbent polymer (SAP). Moreover, you may use what is called a SAP sheet which made SAP a sheet form. As the hydrophilic fiber, synthetic fiber, polymer fiber, or the like may be used instead of the wood pulp fluff. Moreover, you may mix | blend antimicrobial fiber as a hydrophilic fiber.

Next, the

core wrap sheets

10a and 10b will be described. In the absorbent article which concerns on embodiment of this invention, it has the outstanding deodorizing function by using the sanitary paper of this invention mentioned above for the

core wrap sheets

10a and 10b. Moreover, since the

core wrap sheets

10a and 10b have sufficient strength, an absorbent article in which the core wrap sheet is less likely to be twisted or torn is obtained.

It goes without saying that the present invention is not limited to the above-described embodiments, and extends to various modifications and equivalents included in the spirit and scope of the present invention.
An absorptive article is not restricted to the above-mentioned underpants type paper diaper, for example, it is a long and slender piece like a sanitary napkin, and the type which hits a local part may be sufficient. In the above-described embodiment, the liquid-permeable outer layer sheet 2 covers only one surface (body contact side surface) of the absorbent core 4a. However, both surfaces of the absorbent core are covered with the liquid-permeable outer layer sheet, and the absorbent article. It may be possible to absorb urine and the like from both the front and back surfaces.
The core wrap sheet is not limited to the one covering the absorbent core, and may be used by being laminated on the surface of the absorbent core. When a plurality of absorbent cores are stacked, a core wrap sheet may be interposed between the absorbent cores.
Moreover, the absorbent article which concerns on embodiment of this invention can also be applied to the sheet | seat (pet sheet) for pets.

Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples.

<Experiment A: Production of metal ion-containing cellulose fiber>
Softwood bleached kraft pulp is used as the raw material pulp. To this, 0.2 g of 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) is added with 2 g of sodium hypochlorite as a co-oxidant. The mixture was stirred at room temperature for 2 hours to carry out an oxidation reaction to obtain a dispersion of oxidized cellulose fibers (TEMPO oxidized cellulose fibers). This TEMPO oxidized cellulose fiber has a carboxyl group or a carboxylate group on its surface. Table 1 shows the acid group amount (per gram of oxidized cellulose fiber) of the TEMPO oxidized cellulose fiber before containing metal ions.
A metal salt (CuCl ₂ ) aqueous solution having a pH and concentration (per gram of oxidized cellulose fiber) shown in Table 1 was added to the TEMPO oxidized cellulose fiber obtained by the above operation and stirred. Thereby, Cu ions were contained in the oxidized cellulose fiber and washed to remove unreacted metal salts. Table 1 shows the content of metal ions with respect to the oxidized cellulose fiber. In Example 9, an AgNO ₃ aqueous solution was used as the metal salt aqueous solution, and Ag was contained instead of Cu ions.
Thus, it was confirmed in Examples 1 to 9 that metal ion-containing cellulose fibers can be produced.

<Experiment B: Production of sanitary thin paper and core wrap sheet>
Next, the metal ion-containing cellulose fiber of Example 1 and pulp (NBKP and LBKP) were blended at a blending ratio shown in Table 2 to prepare a pulp slurry, and paper making was performed, and sanitary thin paper of Examples B1 to B4. (Tissue paper, toilet paper, paper towel) and the core wrap sheets of Examples B1 to B6 were produced. The sanitary thin paper and the core wrap sheet of Examples B1 to B4 have the same composition.
As Comparative Example 1, the sanitary thin paper sheet of Example B1 (oxidized cellulose fiber containing Cu ions) was further impregnated with 200 ppm of a reducing agent solution, and the filter paper was overlaid to remove excess aqueous solution. It dried with the ventilation dryer for 15 minutes, Cu ion in a sanitary thin paper sheet was reduce | restored into Cu particle | grains, and the tissue paper and the core wrap sheet | seat were manufactured.
As Comparative Example 2, a commercially available metal (Cu and Ag) -containing metal-supported zeolite high-density crystallized pulp (trade name Sergaia (registered trademark)) was blended with NBKP at a ratio shown in Table 2, and paper was made to make tissue paper. And a core wrap sheet was manufactured.

When the sanitary thin paper and core wrap sheet of each of Examples B1 to B6 were observed with a scanning electron microscope, only the fibers of the paper were confirmed. On the other hand, in Comparative Example 1, it was confirmed that metal particles were supported between paper fibers.
Further, the sanitary thin paper and the core wrap sheet of each of Examples B1 to B6 and Comparative Example 1 were subjected to ICP ((High Frequency Inductively Coupled Plasma) emission analysis of the extract after dissolving with strong acid, and both contained metal. From the above, the sanitary thin paper and core wrap sheet of Examples B1 to B6 contain metal ions in the oxidized cellulose fiber, while the sanitary thin paper and core wrap sheet of Comparative Example 1 It can be seen that the metal ions contained in the oxidized cellulose fiber were reduced to metal particles.

The obtained sanitary thin paper and core wrap sheet were evaluated as follows.
<Basis weight>
The basis weight of the obtained sanitary thin paper and core wrap sheet was measured according to JIS P 8124.
<Paper thickness>
The paper thickness (mm / 10 sheets) when the obtained sanitary thin paper and the core wrap sheet were overlapped 10 plies (sheets) was measured with a peacock type paper thickness gauge (trade name). The measurement pressure was 3.7 kPa.
<Tensile strength>
The tensile strength of MD direction and CD direction at the time of drying of the obtained sanitary thin paper and core wrap sheet was measured according to JIS P8113. The sample width was 25 mm. In addition, the tensile strength of MD direction and CD direction at the time of drying is represented by DMD and DCD, respectively.
Further, the tensile strength (WMN) in the MD direction when the obtained sanitary thin paper and core wrap sheet were wet was measured according to JIS P8135. The sample width was 25 mm. In the case of toilet paper, measurement was performed with four samples stacked.

<Water absorption speed>
Measured according to JIS S3104 6.5 (former JIS).
First, a pipette adjusted so that the drop amount of one drop was 0.1 ml was prepared. The test piece was attached to a holding frame, and 0.1 ml of distilled water having a temperature of 20 ± 1 ° C. was dropped from a height of 10 mm on the test piece. The time from when the water droplets reached the test piece until the specular reflection of water completely disappeared was measured with a stopwatch in units of 0.1 second. The test was performed 5 times, and the average value was evaluated as the water absorption rate (seconds).

<Lint (dropping fine powder such as paper powder)>
Dust tests on sanitary thin paper and core wrap sheets were performed according to JIS B9923 (tumbling method), and measurement was performed with a particle counter (product name “KC-01D1” manufactured by Rion). Evaluation was made according to the following criteria. The better the evaluation, the smaller the fall of fine powder such as paper powder and zeolite.
◎: Very good ○: Normal ×: Poor <Deodorizing effect>
A saturated gas of an aqueous ammonia solution (2 mL of ammonia water: 2 mL of water) was inserted into a gas bag with a cock containing four test pieces of 5 cm × 5 cm with a 1.2 mL syringe, and 1.5 L of air was filled with an air pump. The saturated gas was collected from the gas phase in a sealed container containing an aqueous ammonia solution. The ammonia gas concentration in the gas bag after filling with saturated gas and air was 80 to 90 ppm. Next, the suction tube and the rubber tube were connected to the detection tube, and the rubber tube was connected to the gas bag. And the ammonia gas concentration in the gas bag 50 minutes after filling with air was measured.
◎: Very good residual concentration is less than 1/4 of the initial value ○: Normal Residual concentration is less than 1/3 of the initial value and more than 1/4 ×: Bad The residual concentration is more than 1/3 of the initial value

The obtained results are shown in Table 1, Table 2, and Table 3. Table 2 shows the results of sanitary thin paper (tissue paper, toilet paper, paper towel), and Table 3 shows the results of the core wrap sheet.

As is clear from Tables 2 and 3, in each Example, there was little drop of fine powder such as paper powder, and it had an excellent deodorizing function. In particular, in Examples B5 and B6 in which the content of metal ion-containing cellulose fibers in the sanitary thin paper was 5 to 15 wt%, the evaluation of paper powder dropping and deodorizing function was further superior to the other examples. It was.
On the other hand, in the case of Comparative Example 1 in which Cu ions in the oxidized cellulose fiber were reduced to Cu particles, the deodorizing function was slightly lower than in each Example.
In the case of Comparative Example 2 in which paper was made by blending a metal-supported zeolite high-density crystallized pulp (trade name Sergaia (registered trademark)), the fall of fine powder such as paper powder was remarkable.

<Experiment C: Tensile strength and tear length of core wrap sheet>
A pulp slurry using NBKP, which is a general pulp (cellulose fiber), Cu ion-containing cellulose fiber of Example 1 and the metal-supported zeolite high-density crystallized pulp (trade name Sergaia (registered trademark)), respectively, is square. Sheets 1 to 3 having a basis weight of 18 ± 0.5 g / m 2 were prepared by paper making with a hand machine. The paper strength enhancer was not added.
Sheets 1 and 2 were made with NBKP and Cu ion-containing cellulose fibers as 100%. Sheet 3 was paper-made with the same mixing ratio of metal-supported zeolite high-density crystallized pulp (trade name Sergaia (registered trademark)) and pulp (NBKP) as in Comparative Example 2.
For each of the obtained sheets, the basis weight, paper thickness, and tensile strength were measured in the same manner as in Experiment B. The density was calculated from the basis weight and the paper thickness, and the breaking length was calculated from the basis weight and the tensile strength. The tensile strength was measured with a sample width of 25 mm, and the breaking length was determined from the following equation. Further, since the strength of the sheet 1 is low, the tensile strength was measured by stacking three sheets, and the tensile strength per sheet was converted by dividing by 3. Table 4 shows the obtained results.
Breaking length (km) = tensile strength (kgf) × 1000 / {weighing (g / m ² ) × sample width (mm)}

As apparent from Table 4, the sheet 2 has higher strength than the sheet 1. This is presumably because an action like beating treatment works in the production process of metal ion-containing cellulose fibers. Accordingly, the strengths of Examples B1 to B4, in which papermaking raw materials obtained by mixing general pulp (NBKP or the like) and metal ion-containing cellulose fibers are made, are the same as those obtained when general pulp is made.
On the other hand, in the case of the sheet 3 containing 10 wt% of zeolite-supporting cellulose fibers, the strength was reduced by about 20% compared to the sheet 1. This is presumably because the zeolite was crystallized in the cellulose fiber, so that the fiber expanded, obstructing the flattening of the cellulose fiber, and the hydrogen bonds between the fibers decreased. It is also considered that the zeolite-supporting cellulose fibers contain a large amount of short fibers.

2 Outer layer sheet (hydrophilic surface sheet)
4a, 4b Absorbent core 20 Water-absorbent article

main body

10a, 10b Core wrap sheet 200 Water-absorbent article

Claims

Ion of one or more metal elements selected from the group of Ag, Au, Pt, Pd, Ni, Mn, Fe, Ti, Al, Zn and Cu with respect to oxidized cellulose fibers having a carboxyl group or a carboxylate group on the surface Sanitary thin paper containing metal ion-containing cellulose fibers.
The sanitary thin paper according to claim 1, wherein the content of the metal ions with respect to the oxidized cellulose fiber is 10 to 60 mg / g.
An absorbent article having an absorbent core, a core wrap sheet that covers or is laminated on the absorbent core, and a liquid-permeable outer layer sheet that covers at least one surface of the core wrap sheet. And
The said core wrap sheet | seat is an absorptive article which is the sanitary thin paper of Claim 1 or 2.