JP2017113428A - Laminated wet sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminated wet sheet which shows less irritation, ensures antibacterial/deodorant effects, and has increased wiping-off performance and textures.SOLUTION: A laminated wet sheet comprises: a paper sheet which includes a metal-ion- containing cellulose fiber containing one or more metal element ions selected from a group comprising Ag, Au, Pt, Pd, Ni, Mn, Fe, Ti, Al, Zn, and Cu on an oxidized cellulose fiber having a carboxyl group or a carboxylate group on its surface and a pulp fiber; and a fiber web which is laminated on a surface side and a rear face side of the paper sheet respectively and comprises a hydrophilic fiber of 50-85 mass% and a thermal bonding fiber of 15-50 mass%. The laminated wet sheet includes 250-400 mass% of a medicinal solution including 99 mass% or more water.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a wet sheet containing a chemical solution that can be suitably used for cleaning human bodies and animals such as pets.

  In order to wipe off dirt and the like of human bodies and animals such as pets, wet sheets containing a chemical solution are used (Patent Documents 1 and 2). In particular, for use in wiping baby babies, a wet sheet that is not only soft, wiping and deodorizing but also safe and less irritating is desired. For this reason, as a chemical | medical solution, the thing with little addition amount of irritating chemicals (preservative etc.) is requested | required.

JP 2003-20597 A JP 2003-79530 A

However, in the case of a conventional wet sheet, there is a problem that if the amount of chemicals added in the chemical solution is reduced, the antibacterial / deodorizing effect of the chemicals and the long-term storage stability of the chemical solution are reduced.
Moreover, when the ratio of the chemical in the chemical solution is increased in order to improve the antibacterial / deodorizing effect, the touch feeling of the wet sheet may be deteriorated as a problem other than safety.
Accordingly, an object of the present invention is to provide a laminated wet sheet that is less irritating and has improved wiping properties and tactile sensation while ensuring an antibacterial / deodorizing effect.

  In order to solve the above-mentioned problems, the laminated wet sheet of the present invention is made of Ag, Au, Pt, Pd, Ni, Mn, Fe, Ti, Al, Zn with respect to oxidized cellulose fibers having a carboxyl group or a carboxylate group on the surface. And a metal ion-containing cellulose fiber containing ions of one or more metal elements selected from the group of Cu and a pulp fiber, and laminated on the paper sheet front side and back side, respectively. A laminated wet sheet having a hydrophilic fiber of 50 to 85% by mass and a heat-adhesive fiber of 15 to 50% by mass, wherein the chemical liquid containing 99% by mass or more of water is added to the laminated wet sheet. Contains 250-400% by mass.

  According to this laminated wet sheet, since the metal ion-containing cellulose fiber itself in the papermaking sheet has antibacterial / deodorizing performance, the amount of the preservative and deodorant in the chemical solution can be reduced. Thereby, the chemical | medical agent which remains on the to-be-wiped surface (human body or animal skin / mucosa) decreases, and irritation can be reduced. Further, by reducing the amount of the preservative and deodorant in the chemical solution, the water content can be increased to 99% by mass or more, and loose stools can be wiped cleanly. If the chemical contains 99.9% by mass or more of water, it is easier to wipe loose stools.

The papermaking sheet preferably contains 2 to 30% by mass of the metal ion-containing cellulose fiber.
The content of the metal ions with respect to the oxidized cellulose fiber is preferably 10 to 60 mg / g.
The basis weight of the laminated wet sheet is preferably 30 to 100 gsm, and the basis weight of the papermaking sheet is preferably 30 to 50% by mass of the whole laminated wet sheet.
The chemical solution preferably contains 99.9% by mass or more of water.

  According to the present invention, a laminated wet sheet with less irritation and improved wiping property and tactile sensation while ensuring an antibacterial / deodorizing effect can be obtained.

It is a figure which shows the transmission electron microscope image of the metal ion containing cellulose fiber used for the Example.

  The laminated wet sheet according to the embodiment of the present invention has a laminated structure having a papermaking sheet to be described later and fiber webs laminated on the front and back of the papermaking sheet, and contains a chemical solution.

<Paper sheet>
The papermaking sheet has at least one selected from the group consisting of Ag, Au, Pt, Pd, Ni, 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 metal element ions and pulp fibers are included. The “papermaking sheet” refers to a sheet of pulp fibers formed by a papermaking method, and is a papermaking sheet if the pulp fibers are intertwined with a microscope.

  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 a wet sheet 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 obtained by making a raw material containing oxidized cellulose fibers, metal oxides are previously contained in the 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 the 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—. 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 the copper ion as a metal 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 JP2008-001728A. That is, using a precisely weighed dry cellulose sample, 60 mL of a 0.5 to 1 mass% slurry is prepared, 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 of 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. When the amount of acid groups exceeds 2.2 mmol / g, the freeness of paper during wet papermaking may deteriorate and the dehydration load may increase.

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.
Although the density | concentration of metal compound aqueous solution is not specifically limited, 10-80 mass parts is preferable with respect to 100 mass parts of cellulose fibers, and 30-60 mass parts is more preferable.
You may adjust suitably the time which a metal compound is made to contact. Although the temperature at the time of making it contact is not specifically limited, 20-40 degreeC is preferable. In addition, 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, and thus 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 as a metal particle and is present as a metal particle, the metal particle can be confirmed by a scanning electron microscope image or a transmission electron microscope image. Can be judged. 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.

As the pulp 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 a predetermined kind and blending ratio according to the required quality.
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 papermaking sheet preferably contains 2 to 30% by mass of metal ion-containing cellulose fibers.
When the blending ratio of the metal ion-containing cellulose fibers is less than 2% by mass, the antibacterial / deodorant performance due to the metal ion-containing cellulose fibers in the papermaking sheet is lowered, and the amount of preservatives and deodorants in the chemical solution is reduced. Can be difficult.
If the blending ratio of metal ion-containing cellulose fibers exceeds 30% by mass, the pulp fiber ratio in the papermaking sheet will decrease, making it difficult to keep the chemical solution firmly in the papermaking sheet and reducing the ability to wipe loose stools cleanly. There are things to do.

In the metal ion-containing cellulose fiber, the content of metal ion with respect to the oxidized cellulose fiber is preferably 10 to 60 mg / g.
If the metal ion content is less than 10 mg / g, the antibacterial / deodorant performance due to the metal ion-containing cellulose fibers in the papermaking sheet will be reduced, making it difficult to reduce the amount of preservatives and deodorants in the chemical solution. May be.
Producing a metal ion content exceeding 60 mg / g leads to a decrease in the yield of metal ion-containing cellulose fibers, resulting in an increase in cost.

<Fiber web>
The fiber web consists of 50 to 85% by mass of hydrophilic fibers and 15 to 50% by mass of heat-adhesive fibers. The fiber web is obtained by the dry card method, in which short fibers having a length of about 15 to 100 mm are intertwined, and when viewed with a microscope, the fiber length is completely different from that of the above papermaking sheet.
Examples of hydrophilic fibers include natural fibers such as cotton, viscose rayon, and lyocell fibers.
Examples of the heat-bonding fiber include PE fiber, PE / PP composite fiber, PE / PET composite fiber, and low melting point PET / PET composite fiber.
Furthermore, other fibers may be blended to adjust the texture and the like. Examples of other fibers include polyester fibers, and the fiber web sheet is bulky and soft.

<Laminated wet sheet>
The laminated wet sheet has a laminated structure in which a papermaking sheet is interposed between two layers of nonwoven fabric, and the nonwoven fabric on the surface gives a soft touch. Further, since the internal papermaking sheet contains pulp fibers, the water content is high, and it has a function of firmly holding a chemical solution containing 99% by mass or more of water to be described later and wiping loose stool cleanly.
The laminated wet sheet can be integrated by laminating a papermaking sheet between two layers of non-woven fabric, and entangle the whole fiber by, for example, spunlace, and the fibers of each layer by a high-pressure water stream.

<Chemical solution>
The chemical solution contains 99% by mass or more of water in the chemical solution. Since the metal ion-containing cellulose fiber itself in the papermaking sheet has antibacterial / deodorant performance, the amount of the preservative and deodorant in the chemical solution can be reduced. Thereby, the chemical | medical agent which remains on the to-be-wiped surface (human body or animal skin / mucosa) decreases, and irritation can be reduced. Further, by reducing the amount of the preservative and deodorant in the chemical solution, the water content can be increased to 99% by mass or more, and soft stools can be wiped cleanly as described above. If the chemical contains 99.9% by mass or more of water, it is easier to wipe loose stools.
The chemical solution can contain a preservative and a deodorant. Preservatives mainly provide long-term storage stability of chemicals, and deodorants provide antibacterial / deodorant effects.
In addition, since the metal ion-containing cellulose fiber itself in the papermaking sheet has antibacterial / deodorizing performance, it is preferable that the chemical solution does not contain a deodorant and the preservative is contained in an amount of 0.1% by mass or less in the chemical solution.
Preservatives include: benzalkonium chloride; paraoxybenzoate and its sodium salt; benzoic acid and its salts; sorbic acid and its salts; dehydroacetic acid and its salts; phenoxyethanol, phenol, resorcin, benzoic acid pantothenyl ethyl ether , Isopropylmethyphenol, cetylpyridinium chloride, chlorhexidine hydrochloride, orthophenylphenol, chlorhexidine gluconate, chlorxylenol, chlorhexidine, alkylisokilinium bromide, thymol, trichlorocarbanilide, halocarban, hinokitiol, polyaminopropyl biguanide, etc. Can be mentioned.

<Amount of chemical>
The chemical solution is contained in an amount of 250 to 400% by mass based on the laminated wet sheet. The amount (% by mass) of the chemical solution is calculated by (wet mass-dry mass) / dry mass × 100 of the laminated wet sheet.
When the content of the chemical solution is less than 250% by mass with respect to the laminated wet sheet, the amount of water in the chemical solution decreases, and the function of wiping loose stool cleanly is inferior. When the content of the chemical liquid exceeds 400% by mass with respect to the laminated wet sheet, the sheet contains too much water and becomes difficult to handle.
The chemical solution is preferably contained in an amount of 280 to 400% by mass with respect to the laminated wet sheet.

The basis weight of the laminated wet sheet is preferably 30 to 100 gsm, and the basis weight of the papermaking sheet is preferably 30 to 50% by mass of the entire laminated wet sheet.
If the basis weight of the laminated wet sheet is less than 30 gsm, the strength is lowered, and the moisture retention amount per sheet may be reduced, which may make it difficult to remove dirt. If the basis weight of the laminated wet sheet exceeds 100 gsm, the thickness will increase, and it may be difficult to wipe off dirt between fine wrinkles or increase the cost.
If the basis weight of the papermaking sheet is less than 30% by mass of the entire laminated wet sheet, the chemical solution may not be sufficiently retained, and it may be difficult to wipe off loose stool cleanly. You may not be able to get a good touch.
The basis weight is measured by washing the laminated wet sheet and then drying it.

  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.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated concretely, this invention is not limited to these examples of course.

<Production of metal ion-containing cellulose fibers>
After dispersing 5.00 g dry softwood bleached kraft pulp, 39 mg 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) and 514 mg sodium bromide in 500 ml water, The reaction was started by adding 15 mass% sodium hypochlorite aqueous solution so that the amount of sodium hypochlorite was 5.5 mmol with respect to 1 g of pulp (absolutely dry). During the reaction, a 3M NaOH aqueous solution was added dropwise to maintain the pH at 10.0. When the pH no longer changes, the reaction is considered to be complete, the reaction product is filtered through a glass filter, washed with a sufficient amount of water and filtered twice to impregnate water with a solid content of 15% by mass. TEMPO oxidized cellulose fibers were obtained.
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.

Next, the obtained TEMPO oxidized cellulose fibers (which do not contain metal ions at this time) are defibrated (beaten), and the pH and concentration shown in Table 1 are obtained with respect to the obtained TEMPO oxidized cellulose fibers. An aqueous metal salt solution (per gram of TEMPO-oxidized cellulose fiber) was added and stirred. As a result, metal ions were supported on the TEMPO oxidized cellulose fiber.
In addition, in FIG. 1, the transmission electron microscope image of the metal ion containing cellulose fiber used for the Example is shown.

<Laminated wet sheet>
The said metal ion containing cellulose fiber and pulp (NBKP and LBKP) were mix | blended with the compounding ratio shown in Table 2, the pulp slurry was prepared, and the papermaking sheet | seat was made.
Next, the fiber shown in Table 2 was blended to form a fiber web by the dry card method, this fiber web was laminated on the front and back surfaces of the papermaking sheet, and the whole was integrated by a spunlace to produce a laminated wet sheet. . In addition, the rayon fiber was used for the hydrophilic fiber, and the PE / PP composite fiber was used for the thermal bonding fiber. Polyester fibers were used for the other fibers.
<Impregnation of chemicals>
Next, the chemicals having the components shown in Table 2 were impregnated at a ratio shown in Table 2 with respect to the dry laminated wet sheet. As the deodorant, green tea extract (epigallocatechin gallate) was used, and as the preservative, benzalkonium chloride 50% solution was used.

  In addition, when the papermaking sheet | seat was observed with the scanning electron microscope among the lamination | stacking wet sheets of each Example, only the fiber of paper was confirmed. In addition, each papermaking sheet of each example was subjected to ICP ((high frequency inductively coupled plasma) emission analysis of the extract after dissolving with strong acid, and it was confirmed that all contained metal. It can be seen that the papermaking sheet of the laminated wet sheet of each example contains metal ions in the oxidized cellulose fiber.

The following evaluation was performed about the obtained lamination wet sheet.
<Deodorant>
Insert a saturated gas of aqueous ammonia (ammonia water 2mL: water 2mL) into the gas bag with a cock containing 4 pieces of 5cm x 5cm laminated wet sheet test pieces with a 1.2mL syringe, and then add 1.5L of air with an air pump. Filled. 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 the 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 density | concentration in the gas bag 50 minutes after filling with air was measured, and the following references | standards evaluated.
◎: Residual concentration is 1/5 or less of initial ○ ○: Residual concentration exceeds 1/5 of initial and 1/4 or less △: Residual concentration exceeds 1/4 of initial and 1/3 or less ×: Residual concentration is initial More than 1/3 Further, after adding purified water dropwise at a rate of 5 g to 1 g of the laminated wet sheet test piece to make it wet, the deodorizing property was similarly evaluated.
If each evaluation is A or B, there is no practical problem.

<Storage stability>
The laminated wet sheet was packaged in a predetermined packaging bag, unopened and stored at 40 ° C. for 6 months, and then opened. The presence or absence of bacterial growth on the laminated wet sheet was visually evaluated according to the following criteria.
○: No discoloration or odor due to bacterial growth ×: Discoloration or odor due to bacterial growth was observed <Irritation>
According to the 24-hour human closed patch test, the skin of the 20 subjects was wiped off with a laminated wet sheet, and the presence or absence of skin irritation was evaluated according to the following criteria.
○: Negative and pure negative ×: Semi-positive and positive <Wipeability>
The artificial stool was wiped off and evaluated according to the following criteria. What is necessary is just evaluation (circle) and (triangle | delta).
○: Extremely easy to wipe △: Easy to wipe ×: Difficult to wipe <tactile sense>
Evaluation was performed by sensory evaluation (n = 20 persons). What is necessary is just evaluation (circle) and (triangle | delta).
○: Extremely good tactile sensation △: Good tactile sensation ×: Poor tactile sensation

  The obtained results are shown in Tables 1 and 2.

As is clear from Table 2, in each example, the irritation was low, and the antibacterial / deodorant effect and tactile sensation were ensured.
On the other hand, in the case of the comparative example 1 which does not contain a metal ion containing cellulose fiber in a papermaking sheet | seat, in order to improve an antibacterial effect and to provide storage stability, it mix | blended more than 0.1 mass% with the chemical | medical solution. As a result, the irritation and tactile sensation were inferior, and the deodorant was also inferior because no deodorant was contained.
In the case of Comparative Example 2 in which the metal ion content relative to the oxidized cellulose fiber is less than 10 mg / g and the preservative is only 0.1% by mass in the chemical solution, the deodorizing effect due to the metal ion-containing cellulose fiber is reduced. In addition, since the amount of the deodorant is small, the storage stability is also inferior.
In the case of Comparative Example 3 in which the preservative was not added to the chemical solution, the storage stability was inferior.
In each example in which the chemical solution contained 99.9% by mass or more of water, the wiping property was further improved as compared with the comparative example.

Claims (5)

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 A paper sheet containing metal ion-containing cellulose fibers and pulp fibers,
A laminated wet sheet having a fiber web composed of 50 to 85% by mass of hydrophilic fibers and 15 to 50% by mass of thermal adhesive fibers, respectively laminated on the front side and the back side of the papermaking sheet,
A laminated wet sheet comprising 250 to 400% by mass of a chemical solution containing 99% by mass or more of water with respect to the laminated wet sheet.   The laminated wet sheet according to claim 1, wherein the papermaking sheet contains 2 to 30% by mass of the metal ion-containing cellulose fibers.   The laminated wet sheet according to claim 1 or 2, wherein the content of the metal ions with respect to the oxidized cellulose fiber is 10 to 60 mg / g.   The laminated wet sheet according to any one of claims 1 to 3, wherein the basis weight of the laminated wet sheet is 30 to 100 gsm, and the basis weight of the papermaking sheet is 30 to 50% by mass of the whole laminated wet sheet.   The laminated wet sheet according to any one of claims 1 to 4, wherein the chemical solution contains 99.9% by mass or more of water.