JP7099154B2 - Core paper tube and sheet roll - Google Patents

Description

The present invention relates to a core paper tube and a sheet roll.

Conventionally, sheet rolls made by winding sanitary paper such as toilet paper around a core paper tube to form a roll have been widely used. For example, a toilet roll made by winding toilet paper around a core paper tube is used in a toilet space. It is also known that such a toilet roll is provided with a function of alleviating the odor generated in the tray space.

For example, Patent Document 1 discloses a toilet roll obtained by impregnating the inside of a core paper tube of a toilet roll with a polyphenol-based deodorant. Further, Patent Document 2 describes Ag, Au, Pt, Pd, Ni, Mn, Fe, Ti, and Ag, Au, Pt, Pd, Ni, Mn, Fe, and Ti for oxidized cellulose fibers having a carboxyl group or a carboxylate group on the surface of a roll-shaped sheet cored paper tube. It contains a metal ion-containing cellulose fiber containing ions of one or more metal elements selected from the group of Al, Zn and Cu, and the content of the metal ion with respect to the core paper tube is 0.5 mg / g or more. A core paper tube is disclosed. As described above, it has been studied to alleviate the odor generated in the toilet space by imparting a deodorizing function to the core paper tube.

JP-A-2017-562210 Japanese Unexamined Patent Publication No. 2017-132612

As described above, toilet rolls and core paper tubes having a deodorizing function have been developed. However, in the conventional cored paper tube to which a deodorant is applied, there is a problem that the deodorant may unintentionally fall off when the toilet roll is used, and the deodorizing effect is not sustained. .. Further, when ions of a metal element are used as a deodorant, it is difficult to secure a sufficient amount of the supported amount, and there are cases where a sufficient deodorizing effect is not exhibited.

Therefore, in order to solve the problems of the prior art, the present inventors have proceeded with studies for the purpose of providing a core paper tube and a sheet roll capable of exhibiting an excellent deodorizing function.

As a result of diligent studies to solve the above problems, the present inventors can exhibit an excellent deodorizing function by containing fibrous cellulose having a fiber width of 1000 nm or less in the core paper tube. It has been found that a core paper tube and a sheet roll can be obtained.
Specifically, the present invention has the following configurations.

[1] A core paper tube containing fibrous cellulose having a fiber width of 1000 nm or less.
[2] The core paper tube according to [1], wherein the fibrous cellulose has an anionic group.
[3] The core paper tube according to [2], wherein the anionic group is at least one selected from a carboxyl group, a substituent derived from a carboxyl group, a phosphoric acid group and a substituent derived from a phosphoric acid group.
[4] The core paper tube according to [2] or [3], wherein the anion group is at least one selected from a phosphoric acid group and a substituent derived from the phosphoric acid group.
[5] The core paper tube according to any one of [1] to [4], wherein the fibrous cellulose carries at least one metal component selected from Ag, Au, Pt, Pd, Cu and Zn.
[6] The core paper tube according to any one of [1] to [5], wherein the content of fibrous cellulose is 0.05 to 15 g / m ² .
[7] A sheet roll comprising the core paper tube according to any one of [1] to [6] and a sheet wound around the core paper tube.

According to the present invention, it is possible to obtain a core paper tube and a sheet roll capable of exhibiting an excellent deodorizing function.

FIG. 1 is a perspective view illustrating the configuration of a sheet roll having a cored paper tube. FIG. 2 is a graph showing the relationship between the amount of NaOH dropped and the electrical conductivity with respect to the fiber raw material having a phosphoric acid group. FIG. 3 is a graph showing the relationship between the amount of NaOH dropped and the electrical conductivity with respect to the fiber raw material having a carboxyl group.

Hereinafter, the present invention will be described in detail. The description of the constituent elements described below may be based on typical embodiments and specific examples, but the present invention is not limited to such embodiments.

(Core paper tube)
The present invention relates to a cored paper tube containing fibrous cellulose having a fiber width of 1000 nm or less. The core paper tube is a paper tube for winding a strip-shaped sheet. Examples of the band-shaped sheet include toilet paper and kitchen paper. In the present specification, fibrous cellulose having a fiber width of 1000 nm or less is also referred to as fine fibrous cellulose.

Since the core paper tube of the present invention has the above-mentioned structure, it exhibits an excellent deodorizing function. Specifically, since the cored paper tube contains fibrous cellulose having a fiber width of 1000 nm or less, it is necessary to capture functional substances exhibiting a deodorizing function between the fibers or to support them on the fibers. Can be done. As a result, the dropout of the functional substance exhibiting the deodorizing function is suppressed, and the core paper tube can exhibit the excellent deodorizing function for a long period of time.

Examples of the functional substance exhibiting the deodorizing function include at least one metal component selected from Ag, Au, Pt, Pd, Cu and Zn, and such a metal component is Ag. At least one selected from Cu and Zn is preferable, and Ag is particularly preferable. The fibrous cellulose itself having a fiber width of 1000 nm or less also exerts a deodorizing effect.

Since the core paper tube of the present invention has the above-mentioned structure, it can carry other functional substances in addition to the functional substances exhibiting the deodorizing function. Further examples of other functional substances include aromatic substances, antibacterial substances, substances having an action of inactivating viruses, substances having a moisturizing action, and the like. By containing such a functional substance, various functions can be imparted to the core paper tube in addition to the deodorizing function.

Further, since the core paper tube of the present invention has the above-mentioned structure, the strength of the core paper tube is increased. By containing the fine fibrous cellulose, the tensile strength of the sheet constituting the core paper tube can be increased, and further, the tensile strength at the time of wetting can be increased.

The core paper tube may be formed by using a single-layer sheet, or may be formed by using a multi-layered sheet. When the core paper tube is formed by using a sheet having a multi-layer structure, the fine fibrous cellulose may be contained in any layer, but is preferably contained in the innermost layer. This makes it easier for the deodorant function to be exhibited.

The core paper tube is obtained by forming a sheet containing fibrous cellulose having a fiber width of 1000 nm or less into a tubular shape. The sheet containing the fine fibrous cellulose may be a layer made of the fine fibrous cellulose, but is preferably a layer containing other fibers. Examples of other fibers include at least one selected from natural fibers, synthetic fibers and regenerated fibers. Examples of natural fibers include pulp, cotton, wool, silk and the like. Examples of the synthetic fiber include polyester fiber, polyolefin fiber, nylon fiber, acrylic resin fiber and the like. Examples of the recycled fiber include rayon fiber and acetate fiber. Among them, the sheet containing fine fibrous cellulose preferably contains pulp, and preferably contains coarse pulp fibers having a fiber width of more than 1000 nm.

The content of the fine fibrous cellulose in the core paper tube is preferably 0.05 g / m ² or more, more preferably 0.1 g / m ² or more, and 0.5 g / m ² or more. Is even more preferable. The content of the fine fibrous cellulose is preferably 15 g / m ² or less, more preferably 12 g / m ² or less, and even more preferably 10 g / m ² or less.

When the core paper tube contains pulp fibers, the ratio of the pulp fibers to the fine fibrous cellulose is preferably 1: 0.0001 to 1: 0.1, preferably 1: 0.0005 to 1: 0.05. Is more preferable.

The sheet forming the core paper tube may contain other components in addition to the fibrous cellulose having a fiber width of 1000 nm or less and the other fibers described above. Examples of other components include a binder component and the like. Examples of the binder component include thermoplastic resins and starch. Examples of the binder component include water-soluble polymers, specifically, carboxyvinyl polymer, polyvinyl alcohol, alkyl methacrylate / acrylic acid copolymer, polyvinylpyrrolidone, sodium polyacrylate, polyethylene glycol, diethylene glycol, and the like. Examples thereof include triethylene glycol, polyethylene oxide, propylene glycol, dipropylene glycol, polypropylene glycol, isoprene glycol, hexylene glycol, 1,3-butylene glycol, polyacrylamide and the like.

Further, as other components, a dry paper strength agent, a wet paper strength agent, a softener, a fragrance and the like can be mentioned. Examples of the dry paper force agent include cationized starch, polyacrylamide (PAM), carboxymethyl cellulose (CMC) and the like. Examples of the wet paper strength agent include polyamide epichlorohydrin, urea, melamine, and heat-crosslinkable polyacrylamide. Examples of the softener include anionic surfactants, nonionic surfactants, cationic surfactants and the like. Examples of the fragrance include essential oils of plants (lavender, rosemary, peppermint, spearmint, eucalyptus, etc.), menthol, citronellol and the like. The above optional components may be used alone or in combination of two or more.

The basis weight of the sheet forming the core paper tube is preferably 100 to 650 g / m ² , more preferably 120 to 500 g / m ² , and even more preferably 120 to 300 g / m ² . .. By setting the basis weight of the sheet forming the core paper tube within the above range, the deodorizing function can be exhibited more effectively.

FIG. 1 is a perspective view illustrating the configuration of a sheet roll 1 having a core paper tube. Here, the configuration of the toilet roll is taken as an example as the seat roll 1. The core paper tube 10 contains fine fibrous cellulose, and toilet paper is wound around the core paper tube 10 as a sheet 20. As described above, the present invention also relates to a sheet roll 1 including a core paper tube 10 and a sheet 20 wound around the core paper tube 10. The sheet 20 may also contain fine fibrous cellulose.

The inner diameter of the core paper tube used for the sheet roll is preferably 50 mm or less, more preferably 45 mm or less. The inner diameter of the core paper tube is preferably 20 mm or more, and more preferably 30 mm or more.
The diameter of the sheet roll is preferably 100 mm or more, more preferably 105 mm or more, and further preferably 110 mm or more. The diameter of the sheet roll is preferably 300 mm or less.

(Fine fibrous cellulose)
The core paper tube contains fibrous cellulose (fine fibrous cellulose) having a fiber width of 1000 nm or less.

The average fiber width of the fibrous cellulose is preferably 2 nm or more and 1000 nm or less, more preferably 2 nm or more and 100 nm or less, further preferably 2 nm or more and 50 nm or less, and particularly preferably 2 nm or more and 10 nm or less. preferable. By setting the average fiber width of the fibrous cellulose to 2 nm or more, it is possible to suppress the dissolution of the cellulose molecule in water and make it easier to exhibit the effects of the fibrous cellulose on improving strength, rigidity and dimensional stability. can. The fibrous cellulose is, for example, monofibrous cellulose.

The average fiber width of fibrous cellulose is measured, for example, using an electron microscope as follows. First, an aqueous suspension of fibrous cellulose having a concentration of 0.05% by mass or more and 0.1% by mass or less is prepared, and this suspension is cast on a hydrophilized carbon film-coated grid to be a sample for TEM observation. And. If it contains wide fibers, an SEM image of the surface cast on the glass may be observed. Next, observation is performed using an electron microscope image at a magnification of 1000 times, 5000 times, 10000 times, or 50,000 times depending on the width of the fiber to be observed. However, the sample, observation conditions and magnification should be adjusted so as to satisfy the following conditions.
(1) A straight line X is drawn at an arbitrary position in the observation image, and 20 or more fibers intersect the straight line X.
(2) A straight line Y that intersects the straight line perpendicularly is drawn in the same image, and 20 or more fibers intersect the straight line Y.
The width of the fiber intersecting the straight line X and the straight line Y is visually read with respect to the observation image satisfying the above conditions. In this way, at least three sets of observation images of surface portions that do not overlap each other are obtained. Next, for each image, the width of the fiber intersecting the straight line X and the straight line Y is read. As a result, at least 20 fibers × 2 × 3 = 120 fibers are read. Then, the average value of the read fiber widths is taken as the average fiber width of the fibrous cellulose.

The fiber length of the fibrous cellulose is not particularly limited, but is preferably 0.1 μm or more and 1000 μm or less, more preferably 0.1 μm or more and 800 μm or less, and further preferably 0.1 μm or more and 600 μm or less. preferable. By setting the fiber length within the above range, it is possible to suppress the destruction of the crystal region of the fibrous cellulose. It is also possible to set the slurry viscosity of the fibrous cellulose in an appropriate range. The fiber length of the fibrous cellulose can be obtained by, for example, image analysis by TEM, SEM, or AFM.

The fibrous cellulose preferably has an I-type crystal structure. Here, the fact that the fibrous cellulose has an I-type crystal structure can be identified in the diffraction profile obtained from the wide-angle X-ray diffraction photograph using CuKα (λ = 1.5418 Å) monochromatic with graphite. Specifically, it can be identified by having typical peaks at two positions, 2θ = 14 ° or more and 17 ° or less and 2θ = 22 ° or more and 23 ° or less.

The ratio of the type I crystal structure to the fine fibrous cellulose is, for example, preferably 30% or more, more preferably 40% or more, still more preferably 50% or more. As a result, even better performance can be expected in terms of heat resistance and the development of a low coefficient of linear thermal expansion. The crystallinity is determined by a conventional method from the X-ray diffraction profile measured and the pattern (Seagal et al., Textile Research Journal, Vol. 29, p. 786, 1959).

The axial ratio (fiber length / fiber width) of the fibrous cellulose is not particularly limited, but is preferably 20 or more and 10000 or less, and more preferably 50 or more and 1000 or less. By setting the axial ratio to the above lower limit value or more, it is easy to form a sheet containing fine fibrous cellulose. By setting the axial ratio to the above upper limit value or less, it is preferable in that handling such as dilution becomes easy when, for example, fibrous cellulose is treated as an aqueous dispersion.

The fibrous cellulose in this embodiment has, for example, both a crystalline region and a non-crystalline region. In particular, fine fibrous cellulose having both a crystalline region and a non-crystalline region and having a high axial ratio is realized by the method for producing fine fibrous cellulose described later.

The fibrous cellulose in this embodiment preferably has an anionic group. Anionic groups include, for example, a phosphate group or a substituent derived from a phosphate group (sometimes simply referred to as a phosphate group), a carboxyl group or a substituent derived from a carboxyl group (sometimes simply referred to as a carboxyl group), and an anion group. It is preferably at least one selected from a sulfone group or a substituent derived from a sulfone group (sometimes simply referred to as a sulfon group), and is preferably a carboxyl group, a substituent derived from the carboxyl group, a phosphoric acid group and a phosphoric acid group. It is more preferably at least one selected from the substituents derived from, and particularly preferably at least one selected from the phosphate group and the substituents derived from the phosphate group. Since the phosphoric acid group has a larger number of anion groups per molecule than the carboxyl group or the like, it can support a larger number of metal components. As a result, it is considered that a more excellent deodorizing effect is exhibited.

The phosphoric acid group is, for example, a divalent functional group obtained by removing a hydroxyl group from phosphoric acid. Specifically, it is a group represented by -PO ₃ H ₂ . Substituents derived from phosphoric acid groups include substituents such as salts of phosphoric acid groups and phosphoric acid ester groups. The substituent derived from the phosphoric acid group may be contained in the fibrous cellulose as a group (for example, a pyrophosphate group) in which the phosphoric acid group is condensed.
The substituent derived from the phosphoric acid group or the phosphoric acid group is, for example, a substituent represented by the following formula (1).

In equation (1), a, b and n are natural numbers (where a = b × m). Of α ¹ , α ² , ..., α ⁿ and α', a is O ⁻ , and the rest is either R or OR. It is also possible that all of each αn and α'are O ⁻ . R is a hydrogen atom, a saturated-linear hydrocarbon group, a saturated-branched chain hydrocarbon group, a saturated-cyclic hydrocarbon group, an unsaturated-linear hydrocarbon group, and an unsaturated-branched chain hydrocarbon, respectively. A hydrogen group, an unsaturated-cyclic hydrocarbon group, an aromatic group, or an inducing group thereof.

Examples of the saturated-linear hydrocarbon group include, but are not limited to, a methyl group, an ethyl group, an n-propyl group, an n-butyl group and the like. Examples of the saturated-branched chain hydrocarbon group include an i-propyl group and a t-butyl group, but the group is not particularly limited. Examples of the saturated-cyclic hydrocarbon group include, but are not limited to, a cyclopentyl group, a cyclohexyl group and the like. Examples of the unsaturated-linear hydrocarbon group include, but are not limited to, a vinyl group, an allyl group and the like. Examples of the unsaturated-branched chain hydrocarbon group include an i-propenyl group and a 3-butenyl group, but the group is not particularly limited. Examples of the unsaturated-cyclic hydrocarbon group include, but are not limited to, a cyclopentenyl group, a cyclohexenyl group and the like. Examples of the aromatic group include, but are not limited to, a phenyl group, a naphthyl group and the like.

Further, as the inducing group in R, a functional group in which at least one of functional groups such as a carboxyl group, a hydroxyl group, or an amino group is added or substituted with respect to the main chain or side chain of the above-mentioned various hydrocarbon groups. The group is mentioned, but is not particularly limited. The number of carbon atoms constituting the main chain of R is not particularly limited, but is preferably 20 or less, and more preferably 10 or less. By setting the number of carbon atoms constituting the main chain of R to the above range, the molecular weight of the phosphate group can be set to an appropriate range, the penetration into the fiber raw material is facilitated, and the yield of the fine cellulose fiber is increased. You can also do it.

β ^{b +} is a monovalent or higher cation composed of an organic substance or an inorganic substance. Examples of monovalent or higher cations composed of organic substances include aliphatic ammonium or aromatic ammonium, and examples of monovalent or higher valent cations composed of inorganic substances include ions of alkali metals such as sodium, potassium, and lithium. Examples thereof include cations of divalent metals such as calcium and magnesium, hydrogen ions and the like, but the present invention is not particularly limited. These may be applied alone or in combination of two or more. The monovalent or higher cation composed of an organic substance or an inorganic substance is preferably sodium or potassium ion which is hard to yellow when the fiber raw material containing β is heated and is easily industrially used, but is not particularly limited.

The amount of anionic groups introduced into the fibrous cellulose is, for example, preferably 0.10 mmol / g or more, more preferably 0.20 mmol / g or more, and 0.50 mmol / g per 1 g (mass) of the fibrous cellulose. The above is more preferable, and 1.00 mmol / g or more is particularly preferable. The amount of anionic groups introduced into the fibrous cellulose is, for example, preferably 3.65 mmol / g or less, more preferably 3.50 mmol / g or less, and 3.00 mmol / g per 1 g (mass) of the fibrous cellulose. It is more preferably / g or less. By setting the amount of the anion group introduced within the above range, it is possible to facilitate the miniaturization of the fiber raw material and enhance the stability of the fibrous cellulose.
Here, the unit mmol / g indicates the amount of substituents per 1 g of mass of fibrous cellulose when the counter ion of the anionic group is a hydrogen ion (H ⁺ ).

The amount of anionic groups introduced into the fibrous cellulose can be measured, for example, by a conductivity titration method. In the measurement by the conductivity titration method, the introduction amount is measured by determining the change in conductivity while adding an alkali such as an aqueous sodium hydroxide solution to the obtained slurry containing fibrous cellulose.

FIG. 2 is a graph showing the relationship between the amount of NaOH dropped and the electrical conductivity with respect to the fibrous cellulose having a phosphoric acid group. The amount of phosphoric acid group introduced into the fibrous cellulose is measured, for example, as follows. First, the slurry containing fibrous cellulose is treated with a strongly acidic ion exchange resin. If necessary, the same defibration treatment as the defibration treatment step described later may be performed on the measurement target before the treatment with the strong acid ion exchange resin. Next, the change in electrical conductivity is observed while adding an aqueous sodium hydroxide solution to obtain a titration curve as shown in FIG. As shown in FIG. 2, the electrical conductivity drops sharply at first (hereinafter referred to as "first region"). After that, the conductivity begins to increase slightly (hereinafter referred to as "second region"). After that, the increment of conductivity increases (hereinafter referred to as "third region"). The boundary point between the second region and the third region is defined by the point where the second derivative value of the conductivity, that is, the amount of change in the increment (slope) of the conductivity is maximized. Thus, three regions appear on the titration curve. Of these, the amount of alkali required in the first region is equal to the amount of strongly acidic groups in the slurry used for titration, and the amount of alkali required in the second region is equal to the amount of weakly acidic groups in the slurry used for titration. Will be equal. When the phosphoric acid group causes condensation, the weakly acidic group is apparently lost, and the amount of alkali required for the second region is smaller than the amount of alkali required for the first region. On the other hand, the amount of strongly acidic groups is consistent with the amount of phosphorus atoms regardless of the presence or absence of condensation. Therefore, when the term simply refers to the amount of phosphoric acid group introduced (or the amount of phosphoric acid group) or the amount of substituted group introduced (or the amount of substituent), it means the amount of strongly acidic group. Therefore, the value obtained by dividing the amount of alkali (mmol) required in the first region of the titration curve obtained above by the solid content (g) in the slurry to be titrated is the amount of phosphate group introduced (mmol / mmol /). g).

FIG. 3 is a graph showing the relationship between the amount of NaOH dropped and the electrical conductivity with respect to the fibrous cellulose having a carboxyl group. The amount of the carboxyl group introduced into the fibrous cellulose is measured, for example, as follows. First, the slurry containing fibrous cellulose is treated with a strongly acidic ion exchange resin. If necessary, the same defibration treatment as the defibration treatment step described later may be performed on the measurement target before the treatment with the strong acid ion exchange resin. Next, the change in electrical conductivity is observed while adding an aqueous sodium hydroxide solution to obtain a titration curve as shown in FIG. In the titration curve, as shown in FIG. 3, after the electric conductivity decreases, the first region until the increase (slope) of the conductivity becomes almost constant, and then the increase (slope) of the conductivity increases. It is divided into the second area. The boundary point between the first region and the second region is defined by the point where the second derivative value of the conductivity, that is, the amount of change in the increment (slope) of the conductivity is maximized. The value obtained by dividing the amount of alkali (mmol) required in the first region of the titration curve by the solid content (g) in the fine fibrous cellulose-containing slurry to be titrated is the amount of carboxyl group introduced (the amount of carboxyl group introduced). mmol / g).

The above-mentioned amount of carboxyl group introduced (mmol / g) is the amount of substituents per 1 g of mass of fibrous cellulose when the counter ion of the carboxyl group is hydrogen ion (H ⁺ ) (hereinafter, the amount of carboxyl group (acid). Type)) is shown. On the other hand, when the counter ion of the carboxyl group is replaced with an arbitrary cation C so as to have a charge equivalent, the denominator is converted to the mass of the fibrous cellulose when the cation C is a counter ion. Therefore, the amount of carboxyl groups (hereinafter, the amount of carboxyl groups (C type)) possessed by the fibrous cellulose in which the cation C is a counter ion can be obtained.
That is, the amount of carboxyl group introduced is calculated by the following formula.
Carboxyl group introduction amount (C type) = Carboxyl group amount (acid type) / {1 + (W-1) x (carboxyl group amount (acid type)) / 1000}
W: Formulated amount of cation C per valence (for example, Na is 23, Al is 9).

<Manufacturing process of fine fibrous cellulose>
Fine fibrous cellulose is produced from a fiber raw material containing cellulose. The fiber raw material containing cellulose is not particularly limited, but it is preferable to use pulp because it is easily available and inexpensive. Examples of pulp include wood pulp, non-wood pulp, and deinked pulp. The wood pulp is not particularly limited, but is, for example, broadleaf kraft pulp (LBKP), coniferous kraft pulp (NBKP), sulfite pulp (SP), dissolved pulp (DP), soda pulp (AP), and unbleached kraft pulp (UKP). ) And chemical pulp such as oxygen bleached kraft pulp (OKP), semi-chemical pulp such as semi-chemical pulp (SCP) and chemiground wood pulp (CGP), crushed wood pulp (GP) and thermomechanical pulp (TMP, BCTMP), etc. Examples include mechanical pulp. The non-wood pulp is not particularly limited, and examples thereof include cotton pulp such as cotton linter and cotton lint, and non-wood pulp such as hemp, straw and bagasse. The deinking pulp is not particularly limited, and examples thereof include deinking pulp made from used paper. As the pulp of this embodiment, one of the above may be used alone, or two or more of them may be mixed and used.
Among the above pulps, for example, wood pulp and deinked pulp are preferable from the viewpoint of availability. Further, among wood pulps, it is possible to obtain long-fiber fine fibrous cellulose having a large cellulose ratio and a high yield of fine fibrous cellulose during defibration treatment, and having a small decomposition of cellulose in the pulp and a large axial ratio. From the viewpoint, for example, chemical pulp is more preferable, and kraft pulp and sulfite pulp are further preferable.

As the fiber raw material containing cellulose, for example, cellulose contained in ascidians and bacterial cellulose produced by acetic acid bacteria can also be used. Further, instead of the fiber raw material containing cellulose, a fiber formed by a linear nitrogen-containing polysaccharide polymer such as chitin or chitosan can also be used.

<Phosphate group introduction process>
When the fine fibrous cellulose has a phosphoric acid group, the step of producing the fine fibrous cellulose includes a step of introducing a phosphoric acid group. In the phosphoric acid group introduction step, at least one compound (hereinafter, also referred to as “compound A”) selected from compounds capable of introducing a phosphoric acid group by reacting with a hydroxyl group contained in a fiber raw material containing cellulose is introduced into cellulose. It is a step of acting on a fiber raw material containing. By this step, a phosphate group-introduced fiber can be obtained.

In the phosphoric acid group introduction step according to the present embodiment, the reaction between the fiber raw material containing cellulose and the compound A is carried out in the presence of at least one selected from urea and its derivatives (hereinafter, also referred to as “compound B”). You may. On the other hand, the reaction of the fiber raw material containing cellulose with the compound A may be carried out in the absence of the compound B.

As an example of the method of allowing the compound A to act on the fiber raw material in the coexistence with the compound B, there is a method of mixing the compound A and the compound B with the fiber raw material in a dry state, a wet state or a slurry state. Of these, since the reaction uniformity is high, it is preferable to use a fiber raw material in a dry state or a wet state, and it is particularly preferable to use a fiber raw material in a dry state. The form of the fiber raw material is not particularly limited, but is preferably cotton-like or thin sheet-like, for example. Examples of the compound A and the compound B include a method of adding the compound A and the compound B to the fiber raw material in the form of powder, in the form of a solution dissolved in a solvent, or in a state of being heated to a melting point or higher and melted. Of these, since the reaction uniformity is high, it is preferable to add the solution in the form of a solution dissolved in a solvent, particularly in the state of an aqueous solution. Further, the compound A and the compound B may be added to the fiber raw material at the same time, may be added separately, or may be added as a mixture. The method for adding the compound A and the compound B is not particularly limited, but when the compound A and the compound B are in the form of a solution, the fiber raw material may be immersed in the solution to absorb the liquid and then taken out, or the fiber raw material may be added. The solution may be dropped into the water. Further, a required amount of compound A and compound B may be added to the fiber raw material, or an excess amount of compound A and compound B may be added to the fiber raw material, respectively, and then the surplus compound A and compound B may be added by pressing or filtering. It may be removed.

Examples of the compound A used in this embodiment include phosphoric acid or a salt thereof, dehydration-condensed phosphoric acid or a salt thereof, anhydrous phosphoric acid (diphosphorus pentoxide), and the like, but the present invention is not particularly limited. As the phosphoric acid, those having various puritys can be used, and for example, 100% phosphoric acid (normal phosphoric acid) or 85% phosphoric acid can be used. The dehydration-condensed phosphoric acid is one in which two or more molecules of phosphoric acid are condensed by a dehydration reaction, and examples thereof include pyrophosphoric acid and polyphosphoric acid. Examples of the phosphate and the dehydration-condensed phosphate include lithium salts, sodium salts, potassium salts and ammonium salts of phosphoric acid or dehydration-condensed phosphate, which can have various degrees of neutralization. Of these, from the viewpoints of high efficiency of introduction of phosphoric acid group, easy improvement of defibration efficiency in the defibration process described later, low cost, and easy industrial application, phosphoric acid and phosphoric acid A sodium salt, a potassium salt of phosphorus, or an ammonium salt of phosphorus is preferable, and phosphoric acid, sodium dihydrogen phosphate, disodium hydrogen phosphate, or ammonium dihydrogen phosphate is more preferable.

The amount of compound A added to the fiber raw material is not particularly limited, but for example, when the amount of compound A added is converted to the phosphorus atomic weight, the amount of phosphorus atom added to the fiber raw material (absolute dry mass) is 0.5% by mass or more. It is preferably 100% by mass or less, more preferably 1% by mass or more and 50% by mass or less, and further preferably 2% by mass or more and 30% by mass or less. By setting the amount of phosphorus atom added to the fiber raw material within the above range, the yield of fine fibrous cellulose can be further improved. On the other hand, by setting the addition amount of the phosphorus atom to the fiber raw material to be equal to or less than the above upper limit value, the effect of improving the yield and the cost can be balanced.

The compound B used in this embodiment is at least one selected from urea and its derivatives as described above. Examples of the compound B include urea, biuret, 1-phenylurea, 1-benzylurea, 1-methylurea, 1-ethylurea and the like.
From the viewpoint of improving the uniformity of the reaction, compound B is preferably used as an aqueous solution. Further, from the viewpoint of further improving the uniformity of the reaction, it is preferable to use an aqueous solution in which both compound A and compound B are dissolved.

The amount of the compound B added to the fiber raw material (absolute dry mass) is not particularly limited, but is preferably 1% by mass or more and 500% by mass or less, and more preferably 10% by mass or more and 400% by mass or less. It is more preferably 100% by mass or more and 350% by mass or less.

In the reaction between the fiber raw material containing cellulose and compound A, for example, amides or amines may be contained in the reaction system in addition to compound B. Examples of the amides include formamide, dimethylformamide, acetamide, dimethylacetamide and the like. Examples of amines include methylamine, ethylamine, trimethylamine, triethylamine, monoethanolamine, diethanolamine, triethanolamine, pyridine, ethylenediamine, hexamethylenediamine and the like. Among these, triethylamine in particular is known to act as a good reaction catalyst.

In the phosphoric acid group introduction step, it is preferable to add or mix the compound A or the like to the fiber raw material and then heat-treat the fiber raw material. As the heat treatment temperature, it is preferable to select a temperature at which the phosphate group can be efficiently introduced while suppressing the thermal decomposition and hydrolysis reaction of the fiber. The heat treatment temperature is, for example, preferably 50 ° C. or higher and 300 ° C. or lower, more preferably 100 ° C. or higher and 250 ° C. or lower, and further preferably 130 ° C. or higher and 200 ° C. or lower. In addition, equipment having various heat media can be used for the heat treatment, for example, a stirring drying device, a rotary drying device, a disk drying device, a roll type heating device, a plate type heating device, a fluidized layer drying device, and an air stream. A drying device, a vacuum drying device, an infrared heating device, a far infrared heating device, and a microwave heating device can be used.

In the heat treatment according to the present embodiment, for example, a method of adding compound A to a thin sheet-shaped fiber raw material by a method such as impregnation and then heating, or a method of kneading or stirring the fiber raw material and compound A with a kneader or the like is performed. Can be adopted. This makes it possible to suppress uneven concentration of the compound A in the fiber raw material and more uniformly introduce the phosphoric acid group onto the surface of the cellulose fiber contained in the fiber raw material. This is because when the water molecules move to the surface of the fiber raw material due to drying, the dissolved compound A is attracted to the water molecules by the surface tension and also moves to the surface of the fiber raw material (that is, the concentration unevenness of the compound A is caused. It is considered that this is due to the fact that it can be suppressed.

Further, the heating device used for the heat treatment always keeps water retained by the slurry and water generated by the dehydration condensation (phosphate esterification) reaction between the compound A and the hydroxyl group contained in the cellulose or the like in the fiber raw material. It is preferable that the device can be discharged to the outside of the device system. Examples of such a heating device include a ventilation type oven and the like. By constantly discharging the water in the apparatus system, in addition to being able to suppress the hydrolysis reaction of the phosphate ester bond, which is the reverse reaction of phosphate esterification, it is also possible to suppress the acid hydrolysis of sugar chains in the fiber. can. Therefore, it is possible to obtain fine fibrous cellulose having a high axial ratio.

The heat treatment time is preferably 1 second or more and 300 minutes or less, more preferably 1 second or more and 1000 seconds or less, and 10 seconds or more and 800 seconds or less after the water is substantially removed from the fiber raw material. Is more preferable. In the present embodiment, the amount of the phosphoric acid group introduced can be within a preferable range by setting the heating temperature and the heating time within appropriate ranges.

The phosphoric acid group introduction step may be performed at least once, but may be repeated twice or more. By performing the phosphoric acid group introduction step two or more times, many phosphoric acid groups can be introduced into the fiber raw material. In the present embodiment, as an example of a preferable embodiment, there is a case where the phosphoric acid group introduction step is performed twice.

<Carboxyl group introduction process>
When the fine fibrous cellulose has a carboxyl group, the step of producing the fine fibrous cellulose includes a step of introducing a carboxyl group. The carboxyl group introduction step has an oxidation treatment such as ozone oxidation, oxidation by the Fenton method, TEMPO oxidation treatment, a compound having a group derived from carboxylic acid or a derivative thereof, or a group derived from carboxylic acid with respect to the fiber raw material containing cellulose. This is done by treating with an acid anhydride of the compound or a derivative thereof.

The compound having a group derived from a carboxylic acid is not particularly limited, and for example, a dicarboxylic acid compound such as maleic acid, succinic acid, phthalic acid, fumaric acid, glutaric acid, adipic acid, and itaconic acid, citric acid, aconitic acid and the like. Examples include tricarboxylic acid compounds. The derivative of the compound having a group derived from a carboxylic acid is not particularly limited, and examples thereof include an acid anhydride derivative of a compound having a carboxyl group and an acid anhydride derivative of a compound having a carboxyl group. The imide of the acid anhydride of the compound having a carboxyl group is not particularly limited, and examples thereof include an imide of a dicarboxylic acid compound such as maleimide, succinic acidimide, and phthalic acidimide.

The acid anhydride of the compound having a group derived from carboxylic acid is not particularly limited, but for example, a dicarboxylic acid compound such as maleic anhydride, succinic anhydride, phthalic anhydride, glutaric anhydride, adipic anhydride, and itaconic anhydride. Acid anhydride is mentioned. The derivative of the acid anhydride of the compound having a group derived from carboxylic acid is not particularly limited, but for example, a compound having a carboxyl group such as dimethylmaleic acid anhydride, diethylmaleic acid anhydride, diphenylmaleic acid anhydride and the like. Examples thereof include those in which at least a part of the hydrogen atom of the acid anhydride is substituted with a substituent such as an alkyl group or a phenyl group.

When the TEMPO oxidation treatment is carried out in the carboxyl group introduction step, it is preferable to carry out the treatment under the condition that the pH is 6 or more and 8 or less. Such a treatment is also referred to as a neutral TEMPO oxidation treatment. The neutral TEMPO oxidation treatment includes, for example, sodium phosphate buffer (pH = 6.8), pulp as a fiber raw material, TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl) as a catalyst, and the like. This can be done by adding a nitroxy radical and sodium hypochlorite as a sacrificial reagent. Further, by coexisting with sodium chlorite, the aldehyde generated in the oxidation process can be efficiently oxidized to the carboxyl group.

Further, the TEMPO oxidation treatment may be carried out under the condition that the pH is 10 or more and 11 or less. Such a treatment is also referred to as an alkaline TEMPO oxidation treatment. The alkaline TEMPO oxidation treatment can be performed, for example, by adding a nitroxy radical such as TEMPO as a catalyst, sodium bromide as a co-catalyst, and sodium hypochlorite as an oxidizing agent to pulp as a fiber raw material. ..

<Washing process>
In the method for producing fine fibrous cellulose in the present embodiment, a washing step can be performed on the anion group-introduced fiber as needed. The cleaning step is performed, for example, by cleaning the anion group-introduced fibers with water or an organic solvent. Further, the cleaning step may be performed after each step described later, and the number of cleaning steps performed in each cleaning step is not particularly limited.

<Alkaline treatment process (neutralization process)>
In the case of producing fine fibrous cellulose, an alkali treatment may be performed on the fiber raw material between the anion group introduction step and the defibration treatment step described later. The alkaline treatment method is not particularly limited, and examples thereof include a method of immersing the phosphate group-introduced fiber in an alkaline solution.

The alkaline compound contained in the alkaline solution is not particularly limited, and may be an inorganic alkaline compound or an organic alkaline compound. In this embodiment, it is preferable to use, for example, sodium hydroxide or potassium hydroxide as the alkaline compound because of its high versatility. Further, the solvent contained in the alkaline solution may be either water or an organic solvent. Among them, the solvent contained in the alkaline solution is preferably a polar solvent containing water, a polar organic solvent exemplified by alcohol, and the like, and more preferably an aqueous solvent containing at least water. As the alkaline solution, for example, an aqueous solution of sodium hydroxide or an aqueous solution of potassium hydroxide is preferable because of its high versatility.

The temperature of the alkaline solution in the alkaline treatment step is not particularly limited, but is preferably 5 ° C. or higher and 80 ° C. or lower, and more preferably 10 ° C. or higher and 60 ° C. or lower. The immersion time of the phosphoric acid group-introduced fiber in the alkaline solution in the alkaline treatment step is not particularly limited, but is preferably 5 minutes or more and 30 minutes or less, and more preferably 10 minutes or more and 20 minutes or less. The amount of the alkaline solution used in the alkaline treatment is not particularly limited, but is preferably 100% by mass or more and 100,000% by mass or less, and 1000% by mass or more and 10,000% by mass or less, for example, with respect to the absolute dry mass of the phosphate group-introduced fiber. Is more preferable.

In order to reduce the amount of the alkaline solution used in the alkali treatment step, the anion group-introduced fiber may be washed with water or an organic solvent after the anion group introduction step and before the alkali treatment step. After the alkali treatment step and before the defibration treatment step, it is preferable to wash the alkali-treated anion group-introduced fibers with water or an organic solvent from the viewpoint of improving handleability.

<Defibration processing>
Fine fibrous cellulose can be obtained by defibrating the anion-introduced fiber in the defibration treatment step. In the defibration processing step, for example, a defibration processing apparatus can be used. The defibration processing device is not particularly limited, but is, for example, a high-speed defibrator, a grinder (stone mill type crusher), a high-pressure homogenizer or an ultra-high pressure homogenizer, a high-pressure collision type crusher, a ball mill, a bead mill, a disc type refiner, a conical refiner, and a twin shaft. A kneader, a vibration mill, a homomixer under high speed rotation, an ultrasonic disperser, or a beater can be used. Among the above-mentioned defibration processing devices, it is more preferable to use a high-speed defibrator, a high-pressure homogenizer, and an ultra-high-pressure homogenizer, which are less affected by pulverized media and have less risk of contamination.

In the defibration treatment step, for example, it is preferable to dilute the phosphate group-introduced fiber with a dispersion medium to form a slurry. As the dispersion medium, one or more selected from water and an organic solvent such as a polar organic solvent can be used. The polar organic solvent is not particularly limited, but for example, alcohols, polyhydric alcohols, ketones, ethers, esters, aprotonic polar solvents and the like are preferable. Examples of alcohols include methanol, ethanol, isopropanol, n-butanol, isobutyl alcohol and the like. Examples of polyhydric alcohols include ethylene glycol, propylene glycol and glycerin. Examples of the ketone include acetone, methyl ethyl ketone (MEK) and the like. Examples of ethers include diethyl ether, tetrahydrofuran, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monon-butyl ether, propylene glycol monomethyl ether and the like. Examples of the esters include ethyl acetate, butyl acetate and the like. Examples of the aprotonic polar solvent include dimethyl sulfoxide (DMSO), dimethylformamide (DMF), dimethylacetamide (DMAc), N-methyl-2-pyrrolidinone (NMP) and the like.

The solid content concentration of the fine fibrous cellulose during the defibration treatment can be appropriately set. Further, the slurry obtained by dispersing the phosphoric acid group-introduced fiber in a dispersion medium may contain a solid content other than the phosphoric acid group-introduced fiber such as urea having a hydrogen bond property.

(Metal component)
The fine fibrous cellulose preferably carries at least one metal component selected from Ag, Au, Pt, Pd, Cu and Zn. Such a metal component is preferably at least one selected from Ag, Cu and Zn, and is particularly preferably Ag. The above-mentioned metal component is supported by, for example, a coordination bond, a hydrogen bond, or an ionic bond with a phosphoric acid group contained in fine fibrous cellulose having a phosphoric acid group. Such a bonding state can be analyzed by, for example, X-ray photoelectron spectroscopy or infrared spectroscopy.

The content of the metal ion contained in 1 g of the fine fibrous cellulose is preferably 1.0 to 100 mg, more preferably 5.0 to 80 mg.

<Supporting metal components>
As a method of supporting the metal component on the fine fibrous cellulose, a method of contacting the fine fibrous cellulose having an anionic group with an aqueous metal compound can be mentioned. For example, an aqueous solution of a metal compound may be added to a dispersion of fine fibrous cellulose having an anionic group, or an aqueous solution of a metal compound may be added dropwise to a fiber layer containing fine fibrous cellulose having an anionic group. It may be impregnated. As the aqueous solution of the metal compound, for example, a metal salt or an aqueous solution of an organometallic compound can be used. Metal salts include, for example, metal component complexes (complex ions), halides, nitrates, sulfates, and acetates. The metal salt is preferably water-soluble.

The concentration of the aqueous metal compound solution is not particularly limited, but is preferably 10 parts by mass or more and 80 parts by mass or less, and more preferably 30 parts by mass or more and 60 parts by mass or less with respect to 100 parts by mass of fine fibrous cellulose having an anionic group. The contact time of the metal compound may be appropriately adjusted. The temperature at the time of contact is not particularly limited, but is preferably 20 ° C. or higher and 40 ° C. or lower. Further, the pH of the liquid at the time of contact is preferably 2.5 or more and pH 13 or less.

After contacting the aqueous metal compound with the fine fibrous cellulose having an anionic group, a step of reducing the metal compound bonded to the fine fibrous cellulose having an anionic group may be provided. As a result, metal components such as metal particles obtained by reduction are supported on the surface of the cellulose fiber. The reduction reaction may be carried out by a known method, but it is preferable to carry out the reduction reaction while reducing the metal compound so as not to cleave the bond between the metal compound and the anionic group. In the present embodiment, the reduction treatment can be carried out by, for example, a gas phase reduction method using hydrogen or a liquid phase reduction method using a reducing agent such as an aqueous solution of sodium borohydride. Conditions such as time and temperature in the gas phase reduction are appropriately adjusted, and for example, the reaction can be carried out at 50 ° C. or higher and 60 ° C. or lower for about 1 hour or more and 3 hours or less. The reaction temperature in the liquid phase reduction is, for example, preferably 4 ° C. or higher and 40 ° C. or lower, more preferably room temperature. In this embodiment, it is not necessary to carry out the treatment for reducing the metal compound.

Further, a cleaning step may be provided after the aqueous metal compound is brought into contact with the fine fibrous cellulose having an anionic group. For example, when a nitrate aqueous solution is used as the metal compound aqueous solution, nitrate ions and the like can be removed by providing a cleaning step.

The core paper tube may contain, as an optional component, a metal compound, an inorganic compound, or the like that is not supported on the fine fibrous cellulose. Such optional components include, for example, silicon dioxide (SiO ₂ ), aluminum oxide (Al ₂ O ₃ ), iron oxide (Fe ₂ O), yttrium oxide (Y ₂ O ₃ ), indium trioxide (InO), and the like. Magnesium oxide (MgO), Titanium dioxide (TIO ₂ ), Cerium dioxide (CeO ₂ ), Trimanganese tetroxide (Mn ₃ O ₄ ), Niobide pentoxide (Nb ₂ O ₅ ), Silicon carbide (SiC), Boron carbide (SiC) Examples thereof include B4 C), aluminum nitride ₍ AlN), titanium borohydride (TiB ₂ ), zeolite, hydroxyapatite, and nanoplatinum-silica particles in which metal nanoparticles are bonded to silica. Examples of the metal nanoparticles include gold, silver, copper, aluminum, nickel, cobalt, iron, platinum, ruthenium, zinc, panadium, rhodium, palladium, osmium, and iridium.

(Manufacturing method of core paper tube)
The method for producing a cored paper tube preferably includes a step of obtaining a paper tube containing fine fibrous cellulose carrying a metal component.

The step of obtaining the paper tube containing the fine fibrous cellulose carrying the metal component preferably includes a step of bringing the paper tube or the sheet-shaped base paper of the paper tube into contact with the fine fibrous cellulose-containing slurry carrying the metal component. Examples of such a step include a step of spraying a fine fibrous cellulose-containing slurry carrying a metal component, a step of coating the slurry, and a step of impregnating the slurry with a paper tube or a paper tube base paper. Can be done. When the step of containing the fine fibrous cellulose-containing slurry carrying the metal component is the step of spraying the slurry, the solid content of the fine fibrous cellulose-containing slurry carrying the metal component after drying is 0.1 g / m. It is preferably sprayed so as to be ² or more, more preferably 0.5 g / m ² or more, further preferably 1 g / m ² or more, and 2 g / m ² or more. It is particularly preferable to spray so as to be as described above. The upper limit of the spray amount of the fine fibrous cellulose-containing slurry carrying the metal component is not particularly limited, but it is preferably sprayed so as to be, for example, 50 g / m ² . The solid content concentration of the fine fibrous cellulose-containing slurry carrying the metal component to be sprayed is preferably 0.1% by mass or more and 10% by mass or less.

It is preferable to provide a drying step after the above steps (spraying, coating or impregnation step), and the drying method is not particularly limited. The drying step can be performed, for example, by allowing the product to stand in an environment of 23 ° C. and a relative humidity of 50% for 1 hour or longer.

The step of obtaining the paper tube containing the fine fibrous cellulose carrying the metal component is a step of contacting the metal compound aqueous solution after the step of obtaining the paper tube base paper containing the fine fibrous cellulose and the step of obtaining the paper tube base paper. May be provided. In this case, in the step of obtaining the paper tube base paper containing the fine fibrous cellulose, for example, the pulp fiber-containing slurry and the fine fibrous cellulose-containing slurry can be mixed to make the paper tube base paper containing the fine fibrous cellulose.

As a method for producing a tubular paper tube from a sheet-shaped base paper, a conventional method can be adopted. For example, the paper tube can be produced by the following procedure.
(1) The first paper tube base paper (strip-shaped elongated paper: width 70 to 85 mm) is diagonally transferred to a rotating mandrel shaft (cylindrical mandrel) and wound on the mandrel shaft.
(2) Place the second paper tube base paper (strip-shaped elongated paper: width 70 to 85 mm) on the wound first paper tube base paper so that the position of the second paper tube base paper partially overlaps with the first paper tube base paper. The first paper tube base paper and the second paper tube base paper are bonded together to produce a spiral long paper tube.
(3) A long paper tube is cut to a length suitable for the length of the roll (product) to manufacture a paper tube (final product).

The features of the present invention will be described in more detail below with reference to manufacturing examples. The materials, amounts used, ratios, treatment contents, treatment procedures, etc. shown in the following production examples can be appropriately changed as long as they do not deviate from the gist of the present invention. Therefore, the scope of the present invention should not be construed as limiting by the specific examples shown below.

(Example 1)
<Preparation of fine fibrous cellulose>
[Phosphorylation]
As raw material pulp, softwood kraft pulp made by Oji Paper (solid content 93% by mass, basis weight 208 g / m ² sheets, separated and measured according to JIS P 8121, Canadian standard drainage degree (CSF) is 700 ml) It was used. The raw material pulp was subjected to phosphorylation treatment as follows. First, a mixed aqueous solution of ammonium dihydrogen phosphate and urea is added to 100 parts by mass (absolute dry mass) of the raw material pulp to obtain 45 parts by mass of ammonium dihydrogen phosphate, 120 parts by mass of urea, and 150 parts by mass of water. To obtain a chemical-impregnated pulp. Then, the obtained chemical-impregnated pulp was dried in a dryer at 105 ° C. to evaporate the water content and pre-dried. Then, it was heated for 10 minutes with a blower dryer set at 140 ° C., and a phosphoric acid group was introduced into the cellulose in the pulp to obtain phosphorylated pulp.
Then, the obtained phosphorylated pulp was washed. The cleaning treatment is carried out by repeating the operation of pouring 10 L of ion-exchanged water into 100 g (absolute dry mass) of phosphorylated pulp, stirring the pulp dispersion liquid so that the pulp is uniformly dispersed, and then filtering and dehydrating the pulp. gone. When the electrical conductivity of the filtrate became 100 μS / cm or less, the washing end point was set.
The phosphorylated pulp after washing was further subjected to the phosphorylation treatment and the washing treatment once in this order.

[Neutralization treatment]
Next, the phosphorylated pulp after washing was neutralized as follows. First, the washed phosphorylated pulp was diluted with 10 L of ion-exchanged water, and then a 1N aqueous sodium hydroxide solution was added little by little with stirring to obtain a phosphorylated pulp slurry having a pH of 12 or more and 13 or less. .. Next, the phosphorylated pulp slurry was dehydrated to obtain a phosphorylated pulp that had been neutralized.

Next, the phosphorylated pulp after the neutralization treatment was subjected to the above washing treatment.
The infrared absorption spectrum of the phosphorylated pulp thus obtained was measured using FT-IR. As a result, absorption based on the phosphate group was observed near 1230 cm ^-1 , and it was confirmed that the phosphate group was added to the pulp.
Further, when the obtained phosphorylated pulp was tested and analyzed by an X-ray diffractometer, it was found at two positions, 2θ = 14 ° or more and 17 ° or less and 2θ = 22 ° or more and 23 ° or less. A typical peak was confirmed, and it was confirmed that it had cellulose type I crystals.

[Defibration processing]
Ion-exchanged water was added to the obtained phosphorylated pulp to prepare a slurry having a solid content concentration of 2% by mass. This slurry was treated twice with a wet atomizer (Sugino Machine Limited, Starburst) at a pressure of 200 MPa to obtain a fine fibrous cellulose dispersion liquid (1) containing fine fibrous cellulose. By X-ray diffraction, it was confirmed that this fine fibrous cellulose maintained the cellulose type I crystal. Moreover, when the fiber width of the fine fibrous cellulose was measured using a transmission electron microscope, it was 4 nm. The amount of phosphoric acid group (strong acid group amount) measured by the measuring method described later was 1.00 mmol / g.

[Measurement of fiber width]
The fiber width of the fine fibrous cellulose was measured by the following method.
The supernatant of the fine fibrous cellulose dispersion (1) obtained by treatment with a wet atomizing device is adjusted so that the concentration of the fine fibrous cellulose is 0.01% by mass or more and 0.1% by mass or less. It was diluted with water and added dropwise to the hydrophilized carbon grid film. After drying this, it was stained with uranyl acetate and observed with a transmission electron microscope (JEOL-2000EX, manufactured by JEOL Ltd.).

[Measurement of phosphate group amount]
The amount of phosphoric acid group of the fine fibrous cellulose is prepared by diluting the fine fibrous cellulose dispersion (1) containing the target fine fibrous cellulose with ion-exchanged water so that the content is 0.2% by mass. The fibrous cellulose-containing slurry was treated with an ion exchange resin and then titrated with an alkali.
For the treatment with the ion exchange resin, a strongly acidic ion exchange resin (Amberjet 1024; Organo Co., Ltd., conditioned) with a volume of 1/10 is added to the fibrous cellulose-containing slurry, and the mixture is shaken for 1 hour. This was done by pouring onto a mesh with an opening of 90 μm to separate the resin and the slurry.
For titration using alkali, a 0.1 N sodium hydroxide aqueous solution is added to the fibrous cellulose-containing slurry treated with an ion exchange resin once every 30 seconds by 50 μL, and the electrical conductivity shown by the slurry is shown. This was done by measuring the change in the value of. For the amount of phosphoric acid group (mmol / g), the amount of alkali (mmol) required in the region corresponding to the first region shown in FIG. 2 of the measurement results is divided by the solid content (g) in the slurry to be titrated. Calculated.

[Ion exchange treatment and metal ion support]
The obtained fine fibrous cellulose dispersion (1) was diluted with ion-exchanged water so that the content was 0.2% by mass, and then treated with an ion-exchange resin. In the treatment with an ion exchange resin, a strongly acidic ion exchange resin (Amberjet 1024: Organo Co., Ltd., conditioned) with a volume ratio of 1/10 was added to a 0.2% by mass fine fibrous cellulose dispersion for 1 hour. Shaking was performed. Then, it was poured onto a mesh having an opening of 90 μm, and the resin and the slurry were separated. Next, silver nitrate (I) was added so as to be twice the amount of the phosphoric acid group introduced, and the mixture was stirred for 30 minutes to obtain a fine fibrous cellulose-containing slurry (1) carrying silver ions as a metal component. ..

[Washing and slurry preparation]
Next, the obtained slurry (1) was filtered and washed to remove nitrate ions remaining in the system. Specifically, a PTFE membrane filter having a pore size of 1.0 μm is placed on a glass filter, the filter is moistened with IPA, the slurry is poured, and the pressure is reduced at a reduced pressure of −0.09 MPa (absolute vacuum degree of 10 kPa). Filtration was performed. After confirming that a deposit of fine fibrous cellulose carrying silver ions was formed on the PTFE membrane filter, the same amount of water as the original slurry was poured and the process of vacuum filtration was repeated twice. .. The obtained fine fibrous cellulose deposit carrying silver ions was diluted with ion-exchanged water so that the content was 1.0% by mass, and the washed fine fibrous cellulose-containing slurry carrying silver ions ( 1) was obtained.

<Making a paper tube>
A paper tube (inner diameter 38 mm, length 114 mm) was prepared by spirally laminating two sheets of paper tube base paper (width 75 mm, basis weight 150 g / m ² , thickness 230 μm). The fine fibrous cellulose-containing slurry (1) carrying silver ions was applied to the inside of the paper tube so that the solid content after drying was 0.1 g / m ² . It was allowed to stand and air-dried to obtain a paper tube containing fine fibrous cellulose.

(Example 2)
A paper tube was prepared in the same manner as in Example 1 except that the fine fibrous cellulose-containing slurry (1) carrying silver ions was sprayed so that the solid content after drying was 0.5 g / m ² .

(Example 3)
A paper tube was prepared in the same manner as in Example 1 except that the fine fibrous cellulose-containing slurry (1) carrying silver ions was sprayed so that the solid content after drying was 1.0 g / m ² .

(Example 4)
A paper tube was prepared in the same manner as in Example 1 except that the fine fibrous cellulose-containing slurry (1) carrying silver ions was sprayed so that the solid content after drying was 5.0 g / m ² .

(Example 5)
A paper tube was prepared in the same manner as in Example 1 except that the fine fibrous cellulose-containing slurry (1) carrying silver ions was sprayed so that the solid content after drying was 10.0 g / m ² .

(Example 6)
A paper tube was produced in the same manner as in Example 1 except that the fine fibrous cellulose-containing slurry (1) carrying silver ions was not applied.

(evaluation)
(Odor)
The filter paper was placed in a plastic bag (10 L), and the filter paper was impregnated with 1 ml of 10% ammonia water. Next, a paper tube was put in the plastic bag so as not to come into contact with the filter paper in the plastic bag, and the plastic bag was sealed. Five minutes after sealing, the plastic bag was opened, and the odor in the plastic bag was evaluated in the following five stages. The evaluation was performed by 10 subjects, and the average value of the 10 subjects was used as the evaluation value. The results are shown in Table 1.
5: No odor was felt 4: Almost no odor was felt 3: Slight odor was felt 2: Smell was felt 1: Strong odor was felt

(Example 7)
[TEMPO Oxidation]
10000 parts by mass of undried coniferous bleached kraft pulp equivalent to 100 parts by mass of dry mass, 1.6 parts by mass of 2,2,6,6-tetramethylpiperidin-1-oxyl (TEMPO) and 10 parts by mass of sodium bromide It was dispersed in parts by mass. Then, a 13 mass% sodium hypochlorite aqueous solution was added to 1.0 g of pulp so as to be 3.8 mmol, and the reaction was started. During the reaction, a 0.5 M aqueous sodium hydroxide solution was added dropwise to keep the pH at 10 or more and 10.5 or less, and the reaction was considered to be completed when no change was observed in the pH.

Then, the obtained TEMPO oxide pulp was washed. The washing treatment is carried out by dehydrating the pulp slurry after TEMPO oxidation to obtain a dehydrated sheet, pouring 5000 parts by mass of ion-exchanged water, stirring and uniformly dispersing the pulp slurry, and then repeating the operation of filtration and dehydration. rice field. When the electrical conductivity of the filtrate became 100 μS / cm or less, the washing end point was set. Using the obtained carboxyl group-modified cellulose fiber, mechanical treatment was performed in the same manner as in Example 1 to obtain fine fibrous cellulose (2). The average fiber width of the fine fibrous cellulose contained in the fine fibrous cellulose dispersion liquid (2) was 4 nm. The amount of carboxyl groups measured by the measuring method described later was 1.01 mmol / g.

[Measurement of carboxyl group amount]
The amount of carboxyl group of the fine fibrous cellulose was prepared by diluting the fine fibrous cellulose dispersion (2) containing the target fine fibrous cellulose with ion-exchanged water so that the content was 0.2% by mass. The fibrous cellulose-containing slurry was treated with an ion-exchange resin and then titrated with an alkali for measurement.
For the treatment with the ion exchange resin, a strongly acidic ion exchange resin (Amberjet 1024; Organo Co., Ltd., conditioned) with a volume of 1/10 is added to the fibrous cellulose-containing slurry, and the mixture is shaken for 1 hour. This was done by pouring onto a mesh with an opening of 90 μm to separate the resin and the slurry.
In the titration using alkali, a 0.1 N sodium hydroxide aqueous solution is added to the fibrous cellulose-containing slurry treated with an ion exchange resin once every 30 seconds by 50 μL, and the electric conductivity of the slurry is exhibited. This was done by measuring the change in value. For the amount of carboxyl group (mmol / g), the amount of alkali (mmol) required in the region corresponding to the first region shown in FIG. 3 of the measurement results is divided by the solid content (g) in the slurry to be titrated. Calculated.

[Ion exchange treatment and metal ion support]
The obtained fine fibrous cellulose dispersion (2) was subjected to ion exchange treatment and metal ion support in the same manner as in Example 1. In addition, washing was carried out in the same manner as in Example 1 to prepare a fine fibrous cellulose-containing slurry (2) carrying silver ions.

<Making a paper tube>
A paper tube (inner diameter 38 mm, length 114 mm) was prepared by spirally laminating two sheets of paper tube base paper (width 75 mm, basis weight 150 g / m ² , thickness 230 μm). The fine fibrous cellulose-containing slurry (2) carrying silver ions was applied to the inside of the paper tube so that the solid content after drying was 0.1 g / m ² . It was allowed to stand and air-dried to obtain a paper tube containing fine fibrous cellulose.

(Example 8)
A paper tube was prepared in the same manner as in Example 7 except that the fine fibrous cellulose-containing slurry (2) carrying silver ions was sprayed so that the solid content after drying was 0.5 g / m ² .

(Example 9)
A paper tube was prepared in the same manner as in Example 7 except that the fine fibrous cellulose-containing slurry (2) carrying silver ions was sprayed so that the solid content after drying was 1.0 g / m ² .

(Example 10)
A paper tube was prepared in the same manner as in Example 7 except that the fine fibrous cellulose-containing slurry (2) carrying silver ions was sprayed so that the solid content after drying was 5.0 g / m ² .

(Example 11)
A paper tube was prepared in the same manner as in Example 7 except that the fine fibrous cellulose-containing slurry (2) carrying silver ions was sprayed so that the solid content after drying was 10.0 g / m ² .

(evaluation)
Examples 7 to 11 were evaluated by the above-mentioned odor evaluation method.

It was confirmed that the paper tube containing fine fibrous cellulose exerts a deodorizing effect. In particular, in Examples 1 to 5, a paper tube containing fine fibrous cellulose having a phosphoric acid group exhibited a high deodorizing effect.

1 sheet roll 10 roll core paper tube 20 sheet

Claims (4)

A core paper tube containing fibrous cellulose having a fiber width of 1000 nm or less .
The fibrous cellulose is a core paper tube having at least one selected from a phosphoric acid group and a substituent derived from a phosphoric acid group . The core paper tube according to claim 1 , wherein the fibrous cellulose carries at least one metal component selected from Ag, Au, Pt, Pd, Cu and Zn. The core paper tube according to claim 1 or 2 , wherein the content of the fibrous cellulose is 0.05 to 15 g / m ² . The core paper tube according to any one of claims 1 to 3 and the core paper tube.
A sheet roll comprising a sheet wound around the core paper tube.

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