JP5950012B1 - Method for producing fine fibrous cellulose-containing material - Google Patents

Abstract

An object of the present invention is to provide a fine fibrous cellulose-containing material containing fine fibrous cellulose having excellent fluidity. The present invention includes a step of drying a slurry containing fine fibrous cellulose and a metal component by a spray drying method, and the content of fine fibrous cellulose in the slurry is 0 with respect to the total mass of the slurry. 0.0009 to 5.8% by mass, and the fine fibrous cellulose relates to a method for producing a fine fibrous cellulose-containing product having an ionic substituent. [Selection figure] None

Description

  The present invention relates to a method for producing a fine fibrous cellulose-containing material. Specifically, this invention relates to the manufacturing method of the fine fibrous cellulose containing material including the process of spray-drying with a spray dryer.

  In recent years, materials that use reproducible natural fibers have attracted attention due to the substitution of petroleum resources and the growing environmental awareness. Among natural fibers, fibrous cellulose having a fiber diameter of 10 to 50 μm, particularly fibrous cellulose (pulp) derived from wood has been widely used mainly as a paper product so far.

  As the fibrous cellulose, fine fibrous cellulose having a fiber diameter of 1 μm or less is also known. Sheets and composites containing fine fibrous cellulose significantly increase the tensile strength because the contact points between fibers are remarkably increased. Moreover, transparency is greatly improved because the fiber width is shorter than the wavelength of visible light. For example, Patent Document 1 discloses a fiber-reinforced composite material in which high transparency is maintained without being affected by temperature conditions, wavelengths, and the like, and various functions are imparted by combining fibers and a matrix material. Has been. It is also known that fine fibrous cellulose can be used for applications such as thickeners.

  In the case of using fine fibrous cellulose as a thickener, for example, a liquid in which fine fibrous cellulose is dispersed is transported to a processing factory or the like. However, since the liquid in which fine fibrous cellulose is dispersed contains a large amount of dispersion medium, there is a problem that the cost for transportation is high. For this reason, in order to reduce transportation cost, it is desired to make the liquid in which fine fibrous cellulose is dispersed as concentrated as possible.

  As one of concentrated forms, a powder form is known. Also in the field of pulp materials, a technique for making cellulose into powder is conventionally known. For example, Patent Documents 2 and 3 disclose techniques for producing powdery cellulose using a wood pulp sheet as a raw material and using a roller mill, a cutter mill, or the like. Patent Document 4 discloses a cellulose powder suitable for an excipient for compression molding. Here, it is said that cellulose powder excellent in compression moldability can be obtained by spray drying the cellulose dispersion. Further, Patent Document 5 discloses a method for producing a cellulose fine particle aggregate by spray-drying an aqueous suspension containing fine cellulose particles and a cationic resin.

JP 2008-24788 A JP 2014-88538 A JP 2012-207056 A International Publication WO02 / 02643 JP 2013-173861 A

It is said that the cellulose powder preferably has higher fluidity from the viewpoint of ease of filling at the time of packaging and ease of mixing with other components. In the cellulose powder obtained from cellulose having a conventional fiber diameter of about 10 to 50 μm, attempts have been made to improve fluidity and the like. Moreover, about the granulation method, it is tried to manufacture the cellulose powder which has a desired property by using the spray-drying method.
However, the powder containing fine fibrous cellulose has a problem that the fluidity is remarkably inferior compared with the conventional cellulose powder. This is because fine fibrous cellulose is a fiber whose fiber diameter is refined to the nano order and has different physical properties from normal cellulose fibers such as high water retention. For this reason, improvement of the fluidity | liquidity of the powder containing a fine fibrous cellulose is desired.

  Therefore, in order to solve the problems of the prior art, the present inventors have proceeded with studies for the purpose of providing a powder containing fine fibrous cellulose having excellent fluidity (containing fine fibrous cellulose). It was.

As a result of intensive studies to solve the above problems, the present inventors have made a slurry containing fine fibrous cellulose at a predetermined concentration and containing a metal component into a granular form by a predetermined method. The inventors have found that a fine fibrous cellulose-containing material having excellent fluidity can be obtained.
Specifically, the present invention has the following configuration.

[1] A step including spray drying a slurry containing fine fibrous cellulose and a metal component using a spray dryer, and the content of the fine fibrous cellulose in the slurry is 0.009 to the total mass of the slurry. It is 5.8 mass%, and a fine fibrous cellulose is a manufacturing method of the fine fibrous cellulose containing material which has an ionic substituent.
[2] The method for producing a fine fibrous cellulose-containing material according to [1], wherein the content of the fine fibrous cellulose in the slurry is 0.009 to 2.5% by mass with respect to the total mass of the slurry.
[3] The method for producing a fine fibrous cellulose-containing material according to [1] or [2], wherein the content of the metal component in the slurry is 1 to 20% by mass with respect to the total mass of the fine fibrous cellulose.
[4] The method for producing a fine fibrous cellulose-containing material according to any one of [1] to [3], wherein the ionic substituent is an anionic group.
[5] The method for producing a fine fibrous cellulose-containing material according to [4], wherein the anionic group is at least one selected from a phosphate group, a carboxyl group, and a sulfone group.
[6] The method for producing a fine fibrous cellulose-containing material according to any one of [1] to [5], wherein the fine fibrous cellulose has an ionic substituent of 0.1 to 3.5 mmol / g.
[7] The method for producing a fine fibrous cellulose-containing material according to any one of [1] to [6], wherein the water content of the fine fibrous cellulose-containing material is 20% by mass or less.

  According to the present invention, a fine fibrous cellulose-containing material having excellent fluidity can be obtained. Thus, since the fine fibrous cellulose-containing material of the present invention is excellent in fluidity, it is excellent in handling properties such as easy filling.

FIG. 1 is a schematic diagram illustrating the configuration of a spray dryer that can be used in the present invention. FIG. 2 is a graph showing the relationship between the amount of NaOH dropped on the fiber raw material and the electrical conductivity.

Hereinafter, the present invention will be described in detail. The description of the constituent elements described below may be made based on representative embodiments and specific examples, but the present invention is not limited to such embodiments. In the present specification, a numerical range expressed using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value.
Moreover, the value regarding the mass of fibers, such as a cellulose, is based on the absolute dry mass (solid content) except the case where it describes especially. “A and / or B” means at least one of A and B unless otherwise specified, and may be A alone, B alone, or both A and B. Means it may be.

(Method for producing fine fibrous cellulose-containing material)
The present invention relates to a method for producing a fine fibrous cellulose-containing material including a step of spray drying a slurry containing fine fibrous cellulose and a metal component using a spray dryer. Content of the fine fibrous cellulose of the slurry used with the manufacturing method of this invention is 0.009-5.8 mass% with respect to the total mass of a slurry. Further, the fine fibrous cellulose contained in the slurry has an ionic substituent.

The content of the fine fibrous cellulose in the slurry used in the production method of the present invention may be 0.009 to 5.8% by mass with respect to the total mass of the slurry, and may be 0.009 to 4% by mass. Preferably, it is 0.009-3.5 mass%, More preferably, it is 0.009-2.5 mass%, It is especially preferable that it is 0.009-2.0 mass%.
In this invention, the average particle diameter of the fine fibrous cellulose containing material obtained can be made into an appropriate range by making content of the fine fibrous cellulose of a slurry into the said range. Thereby, fluidity | liquidity can be improved and generation | occurrence | production of dust can also be suppressed. For this reason, in the manufacturing method of this invention, productivity of a fine fibrous cellulose containing material can be improved.
In addition, when there is more content of the fine fibrous cellulose of a slurry than the said upper limit, the average particle diameter of the obtained fine fibrous cellulose containing material becomes large, and there exists a tendency for fluidity | liquidity to fall. In addition, when the content of the fine fibrous cellulose in the slurry is less than the lower limit, the resulting fine fibrous cellulose-containing material becomes too fine particles, due to static electricity, attached to the side wall of the drying furnace, etc. Yield may be reduced. Moreover, there is a tendency that the energy for evaporating the moisture is excessive. Furthermore, since it becomes easy to be affected by static electricity or the like, there is a concern that the fluidity is lowered.

  Moreover, the slurry used with the manufacturing method of this invention contains a metal component. Here, it is preferable that content of the metal component in a slurry is 1-20 mass% with respect to the total mass of a fine fibrous cellulose, and it is more preferable that it is 3-15 mass%.

In the production method of the present invention, the fine fibrous cellulose obtained by setting the fine fibrous cellulose concentration in the slurry within a predetermined range in the fine fibrous cellulose having an ionic substituent and the metal component. The fluidity of the inclusion (powder) can be increased.
In the present invention, by using fine fibrous cellulose having an ionic substituent, it is possible to prepare a mixed liquid in which the metal component is uniformly dispersed in the slurry. By adding a metal component, a metal component suppresses aggregation of fine fibrous cellulose fibers at the time of drying, and becomes a fine powder. Since it becomes a fine granular material, it becomes a granular material with high fluidity.

Here, the fine fibrous cellulose-containing material is a granular material obtained by spray drying using a spray dryer. The granular material is a powdery and / or granular substance. The powdery substance is smaller than the granular substance. In general, the powdery substance refers to fine particles having a particle diameter of 1 nm or more and less than 0.1 mm, and the granular substance refers to particles having a particle diameter of 0.1 to 10 mm, but is not particularly limited.
The particle diameter of the granular material in the present specification can be measured and calculated using a laser diffraction method. Specifically, the value is measured using a laser diffraction / scattering particle size distribution measuring device (Microtrac 3300 EXII, Nikkiso Co., Ltd.).

(Spray drying process)
The manufacturing method of the fine fibrous cellulose containing material of this invention includes the process of spray-drying the slurry containing a fine fibrous cellulose and a metal component using a spray dryer. A spray dryer is a device that dries a solution such as a slurry in a short time by atomizing the solution with a sprayer such as a disk atomizer or a nozzle to increase the surface area and bringing it into contact with hot air. The spray dryer used in the present invention generally includes a slurry tank, a drying furnace, a sprayer, a hot air generator, and a recovery tank as main components.

  FIG. 1 is a schematic diagram illustrating the configuration of a spray dryer that can be used in the present invention. As shown in FIG. 1, a spray dryer 100 that can be used in the present invention includes a slurry tank 2, a drying furnace 10, a sprayer 20, a hot air generator 30, and a recovery tank 50.

The slurry tank 2 is a tank for holding a slurry containing fine fibrous cellulose and a metal component. Here, the content of the fine fibrous cellulose is 0.009 to 5.8% by mass, preferably 0.009 to 4% by mass, and more preferably 0.009 to 3.5% by mass with respect to the total mass of the slurry. %, More preferably 0.009 to 2.5 mass%, particularly preferably 0.009 to 2.0 mass%.
Moreover, in the slurry tank 2, the content of the metal component is preferably adjusted to 1 to 20% by mass, more preferably 3 to 15% by mass with respect to the total mass of the fine fibrous cellulose.

  Conventionally, in spray drying using a spray dryer, setting the slurry concentration low tends to be avoided. This is because the purpose was to increase the drying concentration by increasing the slurry concentration and to efficiently produce the target granular material. Further, if the slurry concentration is set low, the slurry may not be sufficiently dried and may adhere to the side wall of the drying furnace, and it has been avoided to reduce the slurry concentration. However, in the present invention, fine fibrous cellulose having an ionic substituent is adjusted to a predetermined slurry concentration, and a metal component is added to obtain a high yield of fine particles having good properties even in a low concentration slurry. Can be obtained at a rate.

  The slurry tank 2 is preferably provided with a stirring device, for example, a magnetic stirrer or a vertical axis stirring device is preferably provided.

  The slurry prepared in the slurry tank 2 is transferred by the pump 4 to the sprayer 20 provided in the drying furnace 10. At this time, it is preferable to send air from the pressurized air generator 6 to the sprayer 20. Thereby, the slurry can be made fine particles efficiently.

  The drying furnace 10 includes a sprayer 20, and slurry is sprayed from the sprayer 20 into the drying furnace 10, and at the same time, hot air is sent from the hot air generator 30. In the drying furnace 10, granulation is performed by drying the solvent contained in the slurry in a short time by contacting the slurry atomized by the sprayer with hot air. In this way, a fine fibrous cellulose-containing material (powdered material) is formed.

  The hot air temperature fed into the drying furnace 10 is preferably 150 to 350 ° C, more preferably 180 to 320 ° C, and further preferably 180 to 250 ° C. The hot air temperature sent to the drying furnace is a temperature detected by an inlet temperature sensor 12 provided between the hot air generator 30 and the drying furnace 10. That is, in this invention, it is preferable that the inlet temperature of a hot air is in the said range, and granulation can be performed efficiently by making inlet temperature into the said range. Moreover, generation | occurrence | production of malfunctions, such as discoloration of the fine fibrous cellulose containing material (powder particle | grains) obtained by making entrance temperature in the said range, can be suppressed.

  The sprayer 20 is not particularly limited as long as it can spray the slurry transferred from the slurry tank 2 in the form of fine particles. Examples of the sprayer 20 include a disk type atomizer and a nozzle. A disk-type atomizer sprays slurry using centrifugal force caused by rotation. In addition, there are two types of nozzles: a pressure nozzle that pressurizes liquid with a pump and applies a turning force, and then atomizes after film formation with an orifice, and a two-fluid nozzle that atomizes by shearing high-pressure air. These sprayers are preferably selected according to the particle shape of the granular material and the properties of the slurry. In the present invention, it is preferable to use a disk-type atomizer. Thereby, there exists a tendency which becomes easy to make the particle diameter of a fine fibrous cellulose containing material (powdered material) into a desired range.

  When using a disk type atomizer as the sprayer 20, the rotation speed of the atomizer is preferably 10000 to 30000 rpm, more preferably 15000 to 25000 rpm. By setting the rotation speed of the atomizer within the above range, when the slurry is sprayed, sufficient atomization is possible, and it is easy to obtain a powder having excellent fluidity.

  The water evaporation amount in the drying furnace 10 is preferably 10 to 200 kg / hour, more preferably 20 to 150 kg / hour, and further preferably 30 to 100 kg / hour. By setting the amount of water evaporation in the drying furnace 10 within the above range, it tends to be easy to obtain a granular material having excellent fluidity.

  The fine fibrous cellulose-containing material (powdered material) granulated in the drying furnace 10 is collected by the collector 40. Examples of the collector include a cyclone type collector and a bag filter. Moreover, you may classify by installing a some cyclone. It is preferable that a suction machine or the like (not shown) is connected to the collector 40, and the particulate matter is collected by a suction action.

  The fine fibrous cellulose-containing material (powder) collected by the collector 40 is held in a collection tank 50 connected to the lower part of the collector 40. Classification may be performed, for example, by providing a filter or the like at the connecting portion between the collector 40 and the collection tank 50. The collector 40 and the collection tank 50 are detachably connected, and the powder and particles collected in the collection tank 50 may be appropriately transferred to a filling / storage process or may be transferred to a classification process or the like.

  An outlet temperature sensor 14 may be provided between the drying furnace 10 and the collector 40. The outlet temperature sensor 14 detects the outlet temperature of the drying furnace 10. Here, the outlet temperature is preferably 40 to 200 ° C, and more preferably 60 to 150 ° C. By setting the outlet temperature within the above range, granulation can be performed efficiently.

  The spray dryer used in the present invention is not limited to the structure described above. As the spray dryer, generally available equipment can be used. For example, ODA-25 type manufactured by Okawara Chemical Industries Co., Ltd. can be used.

  The storage temperature of the fine fibrous cellulose-containing material obtained by the production method described above is preferably 4 to 40 ° C, more preferably 4 to 30 ° C. The pressure is preferably stored at normal pressure. The humidity is preferably 70% or less, and more preferably 60% or less.

  In the case of storing the fine fibrous cellulose-containing material, it is preferably added to a bag such as an aluminum pouch or a container that can be sealed, and stored after sealing. Aluminum pouches and sealed containers can be transported as they are.

(Fine fibrous cellulose)
The slurry used in the production method of the present invention contains fine fibrous cellulose.
Although it does not specifically limit as a fibrous cellulose raw material for obtaining a fine fibrous cellulose, It is preferable to use a pulp from the point of being easy to acquire and cheap. Examples of the pulp include wood pulp, non-wood pulp, and deinked pulp. Examples of wood pulp include hardwood kraft pulp (LBKP), softwood kraft pulp (NBKP), sulfite pulp (SP), dissolved pulp (DP), soda pulp (AP), unbleached kraft pulp (UKP), oxygen bleached craft Chemical pulps such as pulp (OKP) are listed. Moreover, semi-chemical pulps such as semi-chemical pulp (SCP) and chemi-ground wood pulp (CGP), mechanical pulps such as ground wood pulp (GP), thermomechanical pulp (TMP, BCTMP) and the like can be mentioned, but are not particularly limited. Non-wood pulp includes cotton pulp such as cotton linter and cotton lint, non-wood pulp such as hemp, straw and bagasse, cellulose isolated from sea squirts and seaweed, chitin, chitosan, etc., but is not particularly limited. . The deinking pulp includes deinking pulp made from waste paper, but is not particularly limited. The pulp of this embodiment may be used alone or in combination of two or more. Among the above pulps, wood pulp containing cellulose and deinked pulp are preferable in terms of availability. Among wood pulps, chemical pulp has a large cellulose ratio, so the yield of fine fibrous cellulose during fiber refinement (defibration) is high, and the degradation of cellulose in the pulp is small, and the fineness of long fibers with a large axial ratio is high. It is preferable at the point from which fibrous cellulose is obtained. Of these, kraft pulp and sulfite pulp are most preferably selected. Sheets containing long fibrous fine fibrous cellulose having a large axial ratio tend to provide high strength.

  The average fiber width of the fine fibrous cellulose is 1000 nm or less as observed with an electron microscope. The average fiber width is preferably 2 to 1000 nm, more preferably 2 to 100 nm, more preferably 2 to 50 nm, and still more preferably 2 to 10 nm, but is not particularly limited. When the average fiber width of the fine fibrous cellulose is less than 2 nm, the physical properties (strength, rigidity, dimensional stability) as the fine fibrous cellulose tend to be difficult to be expressed because the cellulose molecules are dissolved in water. . The fine fibrous cellulose is monofilamentous cellulose having a fiber width of 1000 nm or less, for example.

  Measurement of the average fiber width of the fine fibrous cellulose by observation with an electron microscope is performed as follows. An aqueous suspension of fine fibrous cellulose having a concentration of 0.05 to 0.1% by mass is prepared, and this suspension is cast on a carbon film-coated grid subjected to a hydrophilic treatment to obtain a sample for TEM observation. When a wide fiber is included, an SEM image of the surface cast on glass may be observed. Observation with an electron microscope image is performed at a magnification of 1000 times, 5000 times, 10000 times, or 50000 times depending on the width of the constituent fibers. However, the sample, observation conditions, and magnification are adjusted to satisfy the following conditions.

(1) One straight line X is drawn at an arbitrary location in the observation image, and 20 or more fibers intersect the straight line X.
(2) A straight line Y perpendicular to the straight line is drawn in the same image, and 20 or more fibers intersect the straight line Y.

  The width of the fiber that intersects with the straight line X and the straight line Y is visually read from the observation image that satisfies the above conditions. In this way, at least three sets of images of the surface portion that do not overlap each other are observed, and the width of the fiber intersecting with the straight line X and the straight line Y is read for each image. Thus, at least 20 × 2 × 3 = 120 fiber widths are read. The average fiber width (sometimes simply referred to as “fiber width”) of fine fibrous cellulose is an average value of the fiber widths read in this way.

  The fiber length of the fine fibrous cellulose is not particularly limited, but is preferably 0.1 to 1000 μm, more preferably 0.1 to 800 μm, and particularly preferably 0.1 to 600 μm. By making the fiber length within the above range, the destruction of the crystalline region of the fine fibrous cellulose can be suppressed, and the slurry viscosity of the fine fibrous cellulose can be made an appropriate range. Note that the fiber length of the fine fibrous cellulose can be determined by image analysis using TEM, SEM, or AFM.

The fine fibrous cellulose preferably has an I-type crystal structure. Here, the fact that the fine fibrous cellulose has a type I crystal structure can be identified in a diffraction profile obtained from a wide-angle X-ray diffraction photograph using CuKα (λ = 1.5418Å) monochromatized with graphite. Specifically, it can be identified by having typical peaks at two positions near 2θ = 14-17 ° and 2θ = 22-23 °.
The proportion of the I-type crystal structure in the fine fibrous cellulose is preferably 30% or more, more preferably 50% or more, and further preferably 70% or more.

  The ratio of the crystal part contained in the fine fibrous cellulose is not particularly limited in the present invention, but it is preferable to use cellulose having a crystallinity obtained by an X-ray diffraction method of 60% or more. The degree of crystallinity is preferably 65% or more, more preferably 70% or more. In this case, further excellent performance can be expected in terms of heat resistance and low linear thermal expansion. The degree of crystallinity is obtained by measuring an X-ray diffraction profile and determining the crystallinity by a conventional method (Seagal et al., Textile Research Journal, 29, 786, 1959).

<Chemical treatment>
Fine fibrous cellulose can be obtained by defibrating a cellulose raw material. Moreover, in this invention, it is preferable to perform a chemical process to a cellulose raw material and to add an ionic substituent to a fine fibrous cellulose before a fibrillation process. The ionic substituent is preferably an anionic group, and examples of the anionic group include at least one substituent selected from a phosphate group, a carboxyl group, and a sulfone group. Among them, the fine fibrous cellulose preferably has a phosphate group.

  The fine fibrous cellulose used in the present invention preferably has an ionic substituent of 0.1 to 3.5 mmol / g. The fine fibrous cellulose having the above-described ionic substituents in the above ratio is preferable in that it can be ultrafine due to the electrostatic repulsion effect. Moreover, the fine fibrous cellulose having an ionic substituent is preferable in that it does not aggregate in water due to the electrostatic repulsion effect and is stable.

<General chemical treatment>
The method of chemical treatment of the cellulose raw material is not particularly limited as long as it is a method capable of obtaining fine fibers. Examples of chemical treatment include acid treatment, ozone treatment, TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl radical) oxidation treatment, enzyme treatment, or sharing with functional groups in cellulose or fiber raw materials. And treatment with a compound capable of forming a bond. In addition, it is preferable that the fine fibrous cellulose used by this invention has a phosphoric acid group or a carboxyl group. For this reason, as a chemical treatment method, treatment with a compound having a phosphate group or a carboxyl group and / or a salt thereof is preferably performed.

Examples of acid treatment include Otto van den Berg; Jeffrey R. Capadona; Christoph Weder;
The method described in Biomacromolecules 2007, 8, 1353-1357. Can be mentioned. Specifically, the fine fibrous cellulose is hydrolyzed with sulfuric acid, hydrochloric acid, or the like. Those produced by high-concentration acid treatment are almost decomposed in non-crystalline regions and have short fibers (also called cellulose nanocrystals), which are also included in fine fibrous cellulose.

  As an example of the ozone treatment, a method described in JP 2010-254726 A can be exemplified, but it is not particularly limited. Specifically, after the fiber is treated with ozone, it is dispersed in water, and the resulting aqueous suspension of the fiber is pulverized.

  An example of TEMPO oxidation includes the method described in Saito T & al. Homogeneous suspensions of individualized microfibrils from TEMPO-catalyzed oxidation of native cellulose. Biomacromolecules 2006, 7 (6), 1687-91. Specifically, after the fiber is subjected to TEMPO oxidation treatment, it is dispersed in water, and the aqueous suspension of the obtained fiber is pulverized.

  As an example of the enzyme treatment, the method described in WO2013 / 176033 (all contents described in WO2013 / 176033 shall be cited in the present specification) can be mentioned, but is not particularly limited. . Specifically, the fiber raw material is treated with an enzyme at least under a condition where the ratio of the enzyme EG activity to the CBHI activity is 0.06 or more.

  The treatment with a compound capable of forming a covalent bond with a functional group in cellulose or a fiber raw material is described in International Publication WO2013 / 073652 (PCT / JP2012 / 079743) “an oxo acid containing a phosphorus atom in its structure, And a method using at least one compound selected from polyoxoacids or salts thereof.

<Introduction of anionic substituent>
The fine fibrous cellulose preferably has an anionic group. Among these, the anionic group is preferably at least one selected from a phosphate group (sometimes referred to as a phosphate ester group), a carboxyl group, and a sulfone group, and at least selected from a phosphate group and a carboxyl group. One type is more preferable, and a phosphate group is particularly preferable.

<Introduced amount of substituent>
The amount of ionic substituent introduced is not particularly limited, but is preferably 0.1 to 3.5 mmol / g, more preferably 0.14 to 2.5 mmol / g, per 1 g (mass) of fine fibrous cellulose. 0.2 to 2.0 mmol / g is more preferable, and 0.2 to 1.8 mmol / g is particularly preferable. By making the introduction amount of the ionic substituent within the above range, the fiber raw material can be easily refined, and the stability of the fine fibrous cellulose can be enhanced. Moreover, the viscosity of the slurry of fine fibrous cellulose can be adjusted to an appropriate range by setting the introduction amount of the ionic substituent within the above range.

<Introduction of phosphate group>
In the present invention, the fine fibrous cellulose preferably has a substituent derived from phosphoric acid such as a phosphate group (sometimes simply referred to as a phosphate group).

<Phosphate group introduction process>
The phosphoric acid group introduction step can be performed by reacting a fiber material containing cellulose with a compound having a phosphoric acid group and / or a salt thereof (hereinafter referred to as “compound A”). This reaction may be performed in the presence of urea and / or a derivative thereof (hereinafter referred to as “compound B”), whereby a phosphate group can be introduced into the hydroxyl group of the fine fibrous cellulose. .

  The phosphate group introduction step necessarily includes a step of introducing a phosphate group into cellulose, and may include an alkali treatment step described later, a step of washing excess reagent, and the like as desired.

  As an example of a method for causing compound A to act on a fiber raw material in the presence of compound B, a method of mixing powder or an aqueous solution of compound A and compound B with a dry or wet fiber raw material can be mentioned. Another example is a method in which powders and aqueous solutions of Compound A and Compound B are added to the fiber raw material slurry. Among these, since the uniformity of the reaction is high, a method of adding an aqueous solution of Compound A and Compound B to a dry fiber material, or a powder or an aqueous solution of Compound A and Compound B to a wet fiber material The method is preferred. Moreover, the compound A and the compound B may be added simultaneously, or may be added separately. Moreover, you may add the compound A and the compound B first used for reaction as aqueous solution, and remove an excess chemical | medical solution by pressing. The form of the fiber raw material is preferably cotton or thin sheet, but is not particularly limited.

Compound A used in this embodiment is a compound having a phosphate group and / or a salt thereof.
Examples of the compound having a phosphate group include, but are not limited to, phosphoric acid, lithium salt of phosphoric acid, sodium salt of phosphoric acid, potassium salt of phosphoric acid, ammonium salt of phosphoric acid, and the like. Examples of the lithium salt of phosphoric acid include lithium dihydrogen phosphate, dilithium hydrogen phosphate, trilithium phosphate, lithium pyrophosphate, and lithium polyphosphate. Examples of the sodium salt of phosphoric acid include sodium dihydrogen phosphate, disodium hydrogen phosphate, trisodium phosphate, sodium pyrophosphate, and sodium polyphosphate. Examples of the potassium salt of phosphoric acid include potassium dihydrogen phosphate, dipotassium hydrogen phosphate, tripotassium phosphate, potassium pyrophosphate, and potassium polyphosphate. Examples of the ammonium salt of phosphoric acid include ammonium dihydrogen phosphate, diammonium hydrogen phosphate, triammonium phosphate, ammonium pyrophosphate, and ammonium polyphosphate.

  Among these, phosphoric acid, sodium phosphate, from the viewpoint of high phosphate group introduction efficiency, easy defibration efficiency in the defibration process described later, low cost, and easy industrial application. A salt, or a potassium salt of phosphoric acid or an ammonium salt of phosphoric acid is preferable. Sodium dihydrogen phosphate or disodium hydrogen phosphate is more preferable.

  In addition, compound A is preferably used as an aqueous solution because the uniformity of the reaction is increased and the efficiency of introduction of phosphate groups is increased. The pH of the aqueous solution of Compound A is not particularly limited, but is preferably 7 or less because the efficiency of introduction of phosphoric acid groups is high, and more preferably 3 to 7 from the viewpoint of suppressing hydrolysis of pulp fibers. The pH of the aqueous solution of Compound A may be adjusted by, for example, using a phosphoric acid group-containing compound that exhibits acidity and an alkalinity, and changing the amount ratio thereof. You may adjust pH of the aqueous solution of the compound A by adding an inorganic alkali or an organic alkali to the thing which shows acidity among the compounds which have a phosphoric acid group.

  The amount of compound A added to the fiber raw material is not particularly limited, but when the amount of compound A added is converted to a phosphorus atomic weight, the amount of phosphorus atom added to the fiber raw material is preferably 0.5 to 100% by weight, and 1 to 50% by weight. % Is more preferable, and 2 to 30% by mass is most preferable. If the amount of phosphorus atoms added to the fiber raw material is within the above range, the yield of fine fibrous cellulose can be further improved. When the addition amount of phosphorus atoms with respect to the fiber raw material exceeds 100% by mass, the effect of improving the yield reaches a peak and the cost of the compound A to be used increases. On the other hand, a yield can be raised by making the addition amount of the phosphorus atom with respect to a fiber raw material more than the said lower limit.

  Examples of the compound B used in this embodiment include urea, thiourea, biuret, phenylurea, benzylurea, dimethylurea, diethylurea, tetramethylurea, benzoleinurea, and hydantoin. Among these, urea is preferable because it is easy to handle at low cost and easily forms a hydrogen bond with a fiber raw material having a hydroxyl group.

  Compound B is preferably used as an aqueous solution in the same manner as Compound A. Moreover, since the uniformity of reaction increases, it is preferable to use the aqueous solution in which both compound A and compound B are dissolved. The amount of compound B added to the fiber raw material is preferably 1 to 300% by mass.

  In addition to Compound A and Compound B, amides or amines may be included in the reaction system. Examples of 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 is known to work as a good reaction catalyst.

<Introduction amount of phosphate group>
The amount of phosphate groups introduced is preferably 0.1 to 3.5 mmol / g, more preferably 0.14 to 2.5 mmol / g, and more preferably 0.2 to 2 per 1 g (mass) of fine fibrous cellulose. 0.0 mmol / g is more preferable, 0.2 to 1.8 mmol / g is more preferable, 0.4 to 1.8 mmol / g is particularly preferable, and 0.6 to 1.8 mmol / g is most preferable. By making the introduction amount of the phosphoric acid group within the above range, the fiber raw material can be easily refined, and the stability of the fine fibrous cellulose can be enhanced. Moreover, the viscosity of the slurry of a fine fibrous cellulose can be adjusted to an appropriate range by making the introduction amount of phosphoric acid groups within the above range.

  The amount of phosphate group introduced into the fiber material can be measured by a conductivity titration method. Specifically, by performing the defibration process step, after treating the resulting fine fibrous cellulose-containing slurry with an ion exchange resin, by determining the change in electrical conductivity while adding an aqueous sodium hydroxide solution, The amount introduced can be measured.

  In conductivity titration, when an alkali is added, the curve shown in FIG. 2 is given. Initially, the electrical conductivity rapidly decreases (hereinafter referred to as “first region”). Thereafter, the conductivity starts to increase slightly (hereinafter referred to as “second region”). Thereafter, the conductivity increment increases (hereinafter referred to as “third region”). That is, three areas appear. Among 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 the amount of weakly acidic groups in the slurry used for titration. Will be equal. When the phosphoric acid group undergoes condensation, apparently weakly acidic groups are lost, and the amount of alkali required in the second region is reduced compared to the amount of alkali required in the first region. On the other hand, the amount of strongly acidic groups coincides with the amount of phosphorus atoms regardless of the presence or absence of condensation, so that the amount of phosphate groups introduced (or the amount of phosphate groups) or the amount of substituent introduced (or the amount of substituents) is simply When said, it represents the amount of strongly acidic group.

<Introduction of carboxyl group>
In the present invention, when the fine fibrous cellulose has a carboxyl group, it is possible to introduce a carboxyl group by using a compound having a group derived from a carboxylic acid in the above-described <phosphate group introduction step>. it can.

  The compound having a carboxyl group is not particularly limited, and examples thereof include dicarboxylic acid compounds such as maleic acid, succinic acid, phthalic acid, fumaric acid, glutaric acid, adipic acid and itaconic acid, and tricarboxylic acid compounds such as citric acid and aconitic acid. It is done.

  The acid anhydride of the compound having a carboxyl group is not particularly limited, but examples thereof include acid anhydrides of dicarboxylic acid compounds such as maleic anhydride, succinic anhydride, phthalic anhydride, glutaric anhydride, adipic anhydride, and itaconic anhydride. It is done.

  Although it does not specifically limit as a derivative of the compound which has a carboxyl group, The derivative of the acid anhydride of the compound which has a carboxyl group and the acid anhydride imidation of a compound which has a carboxyl group are mentioned. Although it does not specifically limit as an acid anhydride imidation thing of a compound which has a carboxyl group, Imidation thing of dicarboxylic acid compounds, such as maleimide, succinic acid imide, and phthalic acid imide, is mentioned.

  The acid anhydride derivative of the compound having a carboxyl group is not particularly limited. For example, at least some of the hydrogen atoms of the acid anhydride of the compound having a carboxyl group, such as dimethylmaleic anhydride, diethylmaleic anhydride, diphenylmaleic anhydride, etc. are substituted (for example, alkyl group, phenyl group, etc. ) Are substituted.

  Among the compounds having a group derived from a carboxylic acid, maleic anhydride, succinic anhydride, and phthalic anhydride are preferred because they are easily applied industrially and easily gasified, but are not particularly limited.

<Cationic substituent introduction>
In this embodiment, a cationic substituent may be introduced into the fine fibrous cellulose as an ionic substituent. For example, a cationic substituent can be introduced into the fiber raw material by adding a cationizing agent and an alkali compound to the fiber raw material and causing the fiber raw material to react.
As the cationizing agent, one having a quaternary ammonium group and a group that reacts with a hydroxyl group of cellulose can be used. Examples of the group that reacts with the hydroxyl group of cellulose include an epoxy group, a functional group having a halohydrin structure, a vinyl group, and a halogen group. Specific examples of the cationizing agent include glycidyltrialkylammonium halides such as glycidyltrimethylammonium chloride and 3-chloro-2-hydroxypropyltrimethylammonium chloride or halohydrin type compounds thereof.
The alkali compound contributes to the promotion of the cationization reaction. Alkali compounds include alkali metal hydroxides or alkaline earth metal hydroxides, alkali metal carbonates or alkaline earth metal carbonates, alkali metal phosphates or alkaline earth metal phosphates, etc. Organic alkali compounds such as ammonia, aliphatic amines, aromatic amines, aliphatic ammoniums, aromatic ammoniums, heterocyclic compounds and their hydroxides, carbonates, phosphates, etc. It may be. The introduction amount of the cationic substituent can be measured using, for example, elemental analysis.

<Alkali treatment>
In the case of producing fine fibrous cellulose, alkali treatment can be performed between the substituent introduction step and the defibration treatment step described later. Although it does not specifically limit as a method of an alkali treatment, For example, the method of immersing a phosphate group introduction | transduction fiber in an alkaline solution is mentioned.
The alkali compound contained in the alkali solution is not particularly limited, but may be an inorganic alkali compound or an organic alkali compound. The solvent in the alkaline solution may be either water or an organic solvent. The solvent is preferably a polar solvent (polar organic solvent such as water or alcohol), and more preferably an aqueous solvent containing at least water.
Of the alkaline solutions, a sodium hydroxide aqueous solution or a potassium hydroxide aqueous solution is particularly preferred because of its high versatility.

Although the temperature of the alkali solution in an alkali treatment process is not specifically limited, 5-80 degreeC is preferable and 10-60 degreeC is more preferable.
Although the immersion time in the alkaline solution in the alkali treatment step is not particularly limited, it is preferably 5 to 30 minutes, and more preferably 10 to 20 minutes.
Although the usage-amount of the alkaline solution in an alkali treatment is not specifically limited, It is preferable that it is 100-100000 mass% with respect to the absolute dry mass of a phosphate group introduction | transduction fiber, and it is more preferable that it is 1000-10000 mass%.

  In order to reduce the amount of alkaline solution used in the alkali treatment step, the phosphate group-introduced fiber may be washed with water or an organic solvent before the alkali treatment step. After the alkali treatment, in order to improve the handleability, it is preferable to wash the alkali-treated phosphate group-introduced fiber with water or an organic solvent before the defibrating treatment step.

<Defibration processing>
The ionic substituent-introduced fiber is defibrated in the defibrating process. In the defibrating process, the fiber is usually defibrated using a defibrating apparatus to obtain a fine fibrous cellulose-containing slurry, but the processing apparatus and the processing method are not particularly limited.
As the defibrating apparatus, a high-speed defibrator, a grinder (stone mill type pulverizer), a high-pressure homogenizer, an ultra-high pressure homogenizer, a high-pressure collision type pulverizer, a ball mill, a bead mill, or the like can be used. Alternatively, as a defibrating apparatus, a device for wet grinding such as a disk type refiner, a conical refiner, a twin-screw kneader, a vibration mill, a homomixer under high-speed rotation, an ultrasonic disperser, or a beater should be used. You can also. The defibrating apparatus is not limited to the above. Preferable defibrating treatment methods include a high-speed defibrator, a high-pressure homogenizer, and an ultra-high pressure homogenizer that are less affected by the grinding media and less worried about contamination.

  In the defibrating process, it is preferable to dilute the fiber raw material with water and an organic solvent alone or in combination to form a slurry, but there is no particular limitation. As the dispersion medium, in addition to water, a polar organic solvent can be used. Preferable polar organic solvents include alcohols, ketones, ethers, dimethyl sulfoxide (DMSO), dimethylformamide (DMF), dimethylacetamide (DMAc), and the like, but are not particularly limited. Examples of alcohols include methanol, ethanol, n-propanol, isopropanol, n-butanol, and t-butyl alcohol. Examples of ketones include acetone and methyl ethyl ketone (MEK). Examples of ethers include diethyl ether and tetrahydrofuran (THF). The dispersion medium may be one type or two or more types. Further, the dispersion medium may contain a solid content other than the fiber raw material, such as urea having hydrogen bonding property.

  In the present invention, the fibrillation treatment may be performed after the fine fibrous cellulose is concentrated and dried. In this case, the concentration and drying methods are not particularly limited, and examples thereof include a method of adding a concentrating agent to a slurry containing fine fibrous cellulose, a generally used dehydrator, a press, and a method using a dryer. Moreover, a well-known method, for example, the method described in WO2014 / 024876, WO2012 / 107642, and WO2013 / 121086 can be used. Further, the concentrated fine fibrous cellulose may be formed into a sheet. The sheet can be pulverized to perform a defibrating process.

  The equipment used for pulverization of fine fibrous cellulose includes high-speed fibrillators, grinders (stone mill type pulverizers), high-pressure homogenizers, ultra-high pressure homogenizers, high-pressure collision type pulverizers, ball mills, bead mills, disk type refiners, and conicals. An apparatus for wet pulverization, such as a refiner, a twin-screw kneader, a vibration mill, a homomixer under high-speed rotation, an ultrasonic disperser, and a beater can be used, but is not particularly limited.

  The fine fibrous cellulose obtained by the above-described method becomes a slurry used for spray drying by diluting with water so as to have a desired concentration. This slurry is spray-dried using a spray dryer to produce a fine fibrous cellulose-containing material.

<Other ingredients>
The slurry containing fine fibrous cellulose may contain other components. Examples of other components include water-soluble polymers and surfactants. Examples of water-soluble polymers include synthetic water-soluble polymers (for example, carboxyvinyl polymer, polyvinyl alcohol, alkyl methacrylate / acrylic acid copolymer, polyvinyl pyrrolidone, sodium polyacrylate, polyethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, Dipropylene glycol, polypropylene glycol, isoprene glycol, hexylene glycol, 1,3-butylene glycol, polyacrylamide, etc.), thickening polysaccharides (eg, xanthan gum, guar gum, tamarind gum, carrageenan, locust bean gum, quince seed, alginic acid , Pullulan, carrageenan, pectin, etc.), cellulose derivatives (eg, carboxymethylcellulose, methylcellulose) Such as hydroxyethyl cellulose), cationized starch, raw starch, oxidized starch, etherified starch, esterified starch, starch such as amylose, glycerol such as glycerin, diglycerin, polyglycerin, etc., hyaluronic acid, hyaluronic acid A metal salt etc. can be mentioned. Moreover, as a surfactant, a nonionic surfactant, an anionic surfactant, and a cationic surfactant can be used.

(Metal component)
The slurry used in the production method of the present invention contains a metal component. The metal component includes, for example, at least one of a metal and a metal oxide. Examples of the metal component include metals exemplified by titanium, zinc, iron, zirconium, tungsten, aluminum, and calcium, and titanium oxide, zinc oxide, iron oxide, zirconium oxide, tungsten oxide, aluminum oxide, and calcium oxide. Examples thereof include fine particles composed of metal oxides exemplified in the above. Among these, it is preferable to use a metal oxide, and it is particularly preferable to use titanium oxide.

The primary average particle diameter of the metal component is preferably 3 to 2000 nm, more preferably 5 to 500 nm, and still more preferably 5 to 50 nm. The specific surface area by BET method of the metal components is preferably 20 to 500 m ² / g, more preferably 30 to 400 m ² / g, more preferably from 50 to 300 m ² / g. By setting the primary average particle diameter and specific surface area of the metal component within the above ranges, the fluidity of the fine fibrous cellulose-containing material can be more effectively increased.

In the present invention, the metal component is preferably a hydrophobic metal oxide. The hydrophobic metal oxide is preferably a metal oxide having a carbon atom content of 1.0% by mass or more, and more preferably a metal oxide having a hydrophobic group. The carbon atom content in the hydrophobic metal oxide is preferably 1.5 to 10% by mass or more, and more preferably 1.5 to 7% by mass or more.
Examples of the hydrophobic group include a group having a hydrocarbon group that does not have a polar group. Examples of the group having a hydrocarbon group include an alkyl group and a phenyl group. Examples of the group having a hydrocarbon group include an alkylsilyl group and a group having a siloxane bond. Examples of the alkylsilyl group include a trimethylsilyl group, a triethylsilyl group, and a triisopropylsilyl group. Examples of the group having a siloxane bond include a dimethylpolysiloxane group.

  Especially, it is preferable that a metal component is a titanium oxide, and it is more preferable that it is a hydrophobic titanium oxide. The hydrophobic titanium oxide is preferably a titanium oxide having a hydrophobic group, and examples of the hydrophobic group include the groups described above.

  Hydrophobicity may be imparted by performing a surface treatment on the metal component using a surface treatment agent. Preferred surface treatment agents include, for example, silane coupling agents, silylating agents, silane coupling agents having an alkyl fluoride group, organic titanate coupling agents, aluminum coupling agents, silicone oils, modified silicone oils, and the like. Can be mentioned.

(Fine fibrous cellulose content)
The present invention may relate to a fine fibrous cellulose-containing material produced by the above-described method for producing a fine fibrous cellulose-containing material. The fine fibrous cellulose-containing material produced by the method for producing a fine fibrous cellulose-containing material has excellent fluidity, and has preferable properties as a granular material.

  The water content in the fine fibrous cellulose-containing material is preferably 20% by mass or less, more preferably 15% by mass or less, and more preferably 10% by mass or less, based on the total mass of the fine fibrous cellulose-containing material. More preferably. By setting the water content within the above range, the fluidity of the fine fibrous cellulose-containing material can be more effectively increased.

The cumulative median diameter of the fine fibrous cellulose-containing material is preferably 100 to 1350 μm, more preferably 200 to 1300 μm, and even more preferably 500 to 1200 μm.
By setting the cumulative median diameter of the fine fibrous cellulose-containing material within the above range, the fluidity can be improved. By setting the cumulative median diameter of the fine fibrous cellulose-containing material to the above lower limit value or more, powdering can be suppressed and loss of the manufacturing process can be reduced. In addition, by setting the cumulative median diameter of the fine fibrous cellulose-containing material to the above lower limit value or more, it is possible to suppress unintended aggregation of the particles in the fine fibrous cellulose-containing material, and to improve fluidity. Can be increased.

The cumulative median diameter of the fine fibrous cellulose-containing material can be measured and calculated using a laser diffraction method. Specifically, the particle size is measured using a laser diffraction scattering type particle size distribution measuring device (Microtrac 3300 EXII, Nikkiso Co., Ltd.). Next, the cumulative curve is obtained by setting the total volume of the fine fibrous cellulose-containing material group as 100%, and the particle diameter at the point where the cumulative curve becomes 50% is calculated.

  The angle of repose of the fine fibrous cellulose-containing material is preferably 4 to 50 °, more preferably 5 to 45 °, still more preferably 5 to 40 °, and more preferably 10 to 40 °. Particularly preferred. The angle of repose is a parameter related to the fluidity of the fine fibrous cellulose-containing material. As the angle of repose is smaller, the fluidity (feed property) of the fine fibrous cellulose-containing material tends to increase. However, when it is set to a certain value or less, powdering occurs and the fluidity (feed property) tends to deteriorate. That is, it is preferable that the angle of repose of the fine fibrous cellulose-containing material is within the above range, whereby the fluidity of the fine fibrous cellulose-containing material can be effectively increased.

  The angle of repose of the fine fibrous cellulose-containing material is measured using an angle of repose measuring instrument (As One). Specifically, 100 ml of fine fibrous cellulose-containing material is charged into a chute of an angle of repose measuring instrument, and the chute is opened to drop the fine fibrous cellulose-containing material downward. Then, the angle formed by the slope of the fine fibrous cellulose-containing material after dropping and the horizontal plane is measured, and the angle of repose of the fine fibrous cellulose-containing material is determined.

  The bulk density of the fine fibrous cellulose-containing material is preferably 0.1 to 0.7 g / ml, more preferably 0.2 to 0.7 g / ml, and 0.2 to 0.5 g / ml. More preferably, it is ml. The larger the bulk density, the smaller the particle size of the particles constituting the fine fibrous cellulose-containing material. For this reason, a contact area with dispersion media, such as water, can be enlarged. On the other hand, if the bulk density is too large, particles in the fine fibrous cellulose-containing material may unintentionally aggregate, which is not preferable. On the other hand, if the bulk density is too small, the shape of the particles becomes non-uniform and the particle size tends to increase, so that the fluidity (feedability) is deteriorated. That is, the bulk density of the fine fibrous cellulose-containing material is preferably within the above range, and thereby the fluidity of the fine fibrous cellulose-containing material can be effectively increased.

The bulk density of the fine fibrous cellulose-containing material is measured using an angle of repose measuring instrument (As One). Specifically, 100 ml of fine fibrous cellulose-containing material is charged into the repose angle measuring device chute, the chute is opened, the fine fibrous cellulose-containing material is dropped to the lower part, and a container placed underneath (full volume vessel) = 50 ml). Next, the raised portion of the swelled fine fibrous cellulose-containing material is horizontally cut to fill the volume. The mass of the fine fibrous cellulose-containing material remaining in the container is weighed, and the bulk density (g / ml) is calculated from the following formula.
Bulk density (g / ml) = Mass of powder (g) / Volume of powder (ml)

(Other ingredients)
The fine fibrous cellulose-containing material may further contain other components. When the fine fibrous cellulose-containing material contains other components, the other components may be added to and mixed with the fine fibrous cellulose-containing material obtained after spray drying, or may be contained in the slurry before spray drying. Good.

  Examples of other components include a hygroscopic agent. Examples of the hygroscopic agent include silica gel, zeolite, alumina, carboxymethyl cellulose, polyvinyl alcohol water-soluble cellulose acetate, polyethylene glycol, sepiolite, calcium oxide, diatomaceous earth, activated carbon, activated clay, white carbon, calcium chloride, magnesium chloride, potassium acetate. , Dibasic sodium phosphate, sodium citrate and water-absorbing polymer.

  Moreover, the fine fibrous cellulose-containing material of the present invention may further contain other components. Examples of other components include water-soluble polymers and surfactants. Examples of water-soluble polymers include synthetic water-soluble polymers (for example, carboxyvinyl polymer, polyvinyl alcohol, alkyl methacrylate / acrylic acid copolymer, polyvinyl pyrrolidone, sodium polyacrylate, polyethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, Dipropylene glycol, polypropylene glycol, isoprene glycol, hexylene glycol, 1,3-butylene glycol, polyacrylamide, etc.), thickening polysaccharides (eg, xanthan gum, guar gum, tamarind gum, carrageenan, locust bean gum, quince seed, alginic acid , Pullulan, carrageenan, pectin, etc.), cellulose derivatives (eg, carboxymethylcellulose, methylcellulose) Such as hydroxyethyl cellulose), cationized starch, raw starch, oxidized starch, etherified starch, esterified starch, starch such as amylose, glycerol such as glycerin, diglycerin, polyglycerin, etc., hyaluronic acid, hyaluronic acid A metal salt etc. can be mentioned. Moreover, as a surfactant, a nonionic surfactant, an anionic surfactant, and a cationic surfactant can be used.

(Redistribution)
The fine fibrous cellulose-containing material obtained in the above-described process is preferably used by being redispersed in a solvent such as water. Although the kind of solvent used in order to obtain such a redispersion slurry is not specifically limited, Water, an organic solvent, and the mixture of water and an organic solvent can be mentioned. Examples of the organic solvent include alcohols, polyhydric alcohols, ketones, ethers, dimethyl sulfoxide (DMSO), dimethylformamide (DMF), dimethylacetamide (DMAc), and the like. Examples of alcohols include methanol, ethanol, n-propanol, isopropanol, n-butanol, and t-butyl alcohol. Examples of polyhydric alcohols include ethylene glycol and glycerin. Examples of ketones include acetone and methyl ethyl ketone. Examples of ethers include diethyl ether, tetrahydrofuran, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono n-butyl ether, and ethylene glycol mono t-butyl ether.

  As the dispersing device used in the step of dispersing the fine fibrous cellulose in the liquid containing the fine fibrous cellulose-containing material, the same device as the defibrating treatment device described in the above <defibrating treatment> may be used. .

(Use)
The use of the fine fibrous cellulose-containing material of the present invention is not particularly limited. The fine fibrous cellulose-containing material is preferably used as a thickener, for example. In this case, the re-dispersed slurry of the fine fibrous cellulose-containing material can be used as a thickener for various purposes (for example, additives to foods, cosmetics, cement, paints, inks, etc.). Moreover, it can also mix with resin and emulsion and can also be used for the use as a reinforcing material. Furthermore, it can form into a film using fine fibrous cellulose redispersion slurry, and can also be used as various films.

  The features of the present invention will be described more specifically with reference to examples and comparative examples. The materials, amounts used, ratios, processing details, processing procedures, and the like shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the specific examples shown below.

[Production Example 1]
Production of Fine Fibrous Cellulose 1 (CNF1) 100 g of urea, 55.3 g of sodium dihydrogen phosphate dihydrate, and 41.3 g of disodium hydrogen phosphate were dissolved in 109 g of water to prepare a phosphorylating reagent.
The dried softwood bleached kraft pulp paper was processed with a cutter mill and a pin mill to form cotton-like fibers. 100 g of this cotton-like fiber was taken in absolute dry mass, and the phosphorylating reagent was sprayed evenly with a spray, and then kneaded by hand to obtain a chemical-impregnated pulp.
The obtained chemical-impregnated pulp was heat-treated for 160 minutes in a blower dryer with a damper heated to 140 ° C. to obtain phosphorylated pulp.

The obtained phosphorylated pulp was fractionated by 100 g, and 10 L of ion-exchanged water was poured, stirred and dispersed uniformly, and then subjected to filtration and dehydration to obtain a dehydrated sheet, which was repeated twice. Next, the obtained dehydrated sheet was diluted with 10 L of ion-exchanged water, and a 1N sodium hydroxide aqueous solution was added little by little while stirring to obtain a pulp slurry having a pH of 12 to 13. Thereafter, the pulp slurry was dehydrated to obtain a dehydrated sheet, and then 10 L of ion exchange water was added. The step of stirring and dispersing uniformly, followed by filtration and dehydration to obtain a dehydrated sheet was repeated twice. An infrared absorption spectrum of the obtained dehydrated sheet was measured by FT-IR. As a result, absorption based on phosphate groups was observed at 1320 to 1290 cm ⁻¹ , confirming the addition of phosphate groups. Therefore, the obtained dehydrated sheet (phosphoric acid oxyacid-introduced cellulose) was one in which a part of the hydroxyl group of cellulose was substituted with the functional group of the following structural formula (1).

In the formula, a, b, m and n each independently represent a natural number (where a = b × m). α ¹ , α ² ,..., α ⁿ and α ′ each independently represent R or OR. R represents a hydrogen atom, a saturated-linear hydrocarbon group, a saturated-branched hydrocarbon group, a saturated-cyclic hydrocarbon group, an unsaturated-linear hydrocarbon group, an unsaturated-branched hydrocarbon group. , Aromatic groups, and any of these derived groups. β is a monovalent or higher cation composed of an organic substance or an inorganic substance.

Ion exchange water was added to the obtained phosphorylated cellulose to prepare a 0.5 mass% slurry. This slurry was defibrated for 30 minutes under a condition of 21500 rotations / minute using a defibrating apparatus (Cleamix-2.2S, manufactured by M Technique Co., Ltd.) to obtain a cellulose 1 suspension.
This cellulose 1 suspension was further treated once with a wet atomizer ("Ultimizer" manufactured by Sugino Machine Co., Ltd.) at a pressure of 245 MPa to obtain fine fibrous cellulose 1 (CNF1). By X-ray diffraction, fine fibrous cellulose 1 (CNF1) maintained a cellulose type I crystal.

(Measurement of phosphate group introduction amount (substituent amount))
The amount of substituent introduction is the amount of phosphate groups introduced into the fiber material, and the larger this value, the more phosphate groups are introduced. The amount of substituent introduced was measured by diluting the target fine fibrous cellulose with ion-exchanged water so that the content was 0.2% by mass, and then treating with ion-exchange resin and titration with alkali. In the treatment with an ion exchange resin, 1/10 by volume of a strongly acidic ion exchange resin (Amberjet 1024; Organo Co., Ltd., conditioned) is added to the 0.2 mass% fibrous cellulose-containing slurry and shaken for 1 hour. Went. Thereafter, the mixture was poured onto a mesh having an opening of 90 μm to separate the resin and the slurry. In titration using an alkali, a change in the value of electrical conductivity exhibited by the slurry was measured while adding a 0.1N sodium hydroxide aqueous solution to the fibrous cellulose-containing slurry after ion exchange. That is, the alkali amount (mmol) required in the first region of the curve shown in FIG. 2 was divided by the solid content (g) in the titration target slurry to obtain the substituent introduction amount (mmol / g).

[Production Example 2]
Production of fine fibrous cellulose 2 (CNF2) Undried softwood bleached kraft pulp equivalent to a dry mass of 200 g, TEMPO 2.5 g, and sodium bromide 25 g were dispersed in 1500 ml of water. Then, 13 mass% sodium hypochlorite aqueous solution was added so that the quantity of sodium hypochlorite might be set to 5.0 mmol with respect to 1.0 g of pulp, and reaction was started. During the reaction, a 0.5 M aqueous sodium hydroxide solution was added dropwise to maintain the pH at 10 to 11, and the reaction was terminated when no change in pH was observed.
Thereafter, the pulp slurry was dehydrated to obtain a dehydrated sheet, and then 10 L of ion exchange water was added. Next, after stirring and uniformly dispersing, the process of dewatering by filtration to obtain a dehydrated sheet was repeated twice. An infrared absorption spectrum of the obtained dehydrated sheet was measured by FT-IR. As a result, absorption based on a carboxyl group was observed at 1730 cm ⁻¹ , confirming the addition of a carboxyl group. Using this dehydrated sheet (TEMPO oxidized cellulose), fine fibrous cellulose was prepared.

Ion exchange water was added to the TEMPO-oxidized cellulose to which the carboxyl group was added as described above to prepare a slurry of 0.5% by mass. This slurry was defibrated for 30 minutes at 21500 rpm using a defibrating apparatus (Cleamix-2.2S, manufactured by MTechnic Co., Ltd.) to obtain a cellulose 2 suspension.
This cellulose 2 suspension was further treated 10 times at a pressure of 245 MPa with a wet atomizer (“Ultimizer” manufactured by Sugino Machine Co., Ltd.) to obtain fine fibrous cellulose 2 (CNF2). By X-ray diffraction, fine fibrous cellulose 2 (CNF2) maintained the cellulose I type crystal.

<Measurement of fiber width>
The fiber width of the fine fibrous cellulose 1 and 2 was measured by the following method.
The supernatant liquid of the defibrated pulp slurry was diluted with water to a concentration of 0.01 to 0.1% by mass and dropped onto a hydrophilic carbon grid membrane. After drying, it was stained with uranyl acetate and observed with a transmission electron microscope (JEOL-2000EX, manufactured by JEOL Ltd.). In Production Examples 1 and 2, it was confirmed that the fine fibrous cellulose had a width of about 4 nm.

  About the crystallinity degree of the fine fibrous cellulose 1 and 2, it measured using the X-ray-diffraction apparatus and calculated | required from the following formula. The “crystallization index” in the formula below is also referred to as “crystallinity”.

Cellulose type I crystallization index (%) = [(I22.6-I18.5) /I22.6] × 100 (1)
[I22.6 is the diffraction intensity of the grating plane (002 plane) (diffraction angle 2θ = 22.6 °) in X-ray diffraction, and I18.5 is the diffraction of the amorphous part (diffraction angle 2θ = 18.5 °). Indicates strength. ]
0.45 ≦ αω (m · rad / sec) (2)
[Α represents a half amplitude (m), and ω represents an angular velocity (rad / sec). ].

  The amount of substituents and crystallinity of the fine fibrous celluloses 1 and 2 are shown in Table 1.

<Example 1>
CNF1 was dispersed in water so that the solid content concentration was 0.01% by mass. To this dispersion, hydrophobic titanium oxide (STV-455, manufactured by Titanium Industry Co., Ltd.) was added so as to be 10% by mass with respect to the total mass of CNF1, and stirred until uniform. The obtained dispersion was spray-dried using a spray dryer (Okawara Kakoki Co., Ltd .: ODA-25 type). The spray dryer has a drying furnace to which hot air is sent, and the inlet temperature of the drying furnace to which hot air is sent is 200 ° C. and the outlet temperature is 90 ° C. The amount of water evaporated in the drying furnace was 50 kg / hour. The spray dryer has an atomizer for spraying the dispersion, and the rotation speed of the atomizer was set to 17000 rpm. Thus, the fine fibrous cellulose containing material of Example 1 was obtained. The water content of the fine fibrous cellulose-containing material was 5% by mass or less.

<Example 2>
A fine fibrous cellulose-containing material of Example 2 was obtained in the same manner as in Example 1 except that CNF1 was dispersed in water so that the solid content concentration was 0.1% by mass.

<Example 3>
A fine fibrous cellulose-containing material of Example 3 was obtained in the same manner as in Example 1 except that CNF1 was dispersed in water so that the solid content concentration was 0.2% by mass.

<Example 4>
A fine fibrous cellulose-containing material of Example 4 was obtained in the same manner as in Example 1 except that CNF1 was dispersed in water so that the solid content concentration was 0.5% by mass.

<Example 5>
A fine fibrous cellulose-containing material of Example 5 was obtained in the same manner as in Example 1 except that CNF1 was dispersed in water so that the solid content concentration was 1.0% by mass.

<Example 6>
A fine fibrous cellulose-containing material of Example 6 was obtained in the same manner as in Example 1 except that CNF1 was dispersed in water so that the solid content concentration was 2.0% by mass.

<Example 7>
A fine fibrous cellulose-containing material of Example 7 was obtained in the same manner as in Example 1 except that CNF1 was dispersed in water so that the solid content concentration was 3.0% by mass.

<Example 8>
A fine fibrous cellulose-containing material of Example 8 was obtained in the same manner as in Example 1 except that CNF1 was dispersed in water so that the solid content concentration was 4.0% by mass.

<Example 9>
A fine fibrous cellulose-containing material of Example 9 was obtained in the same manner as Example 1, except that CNF1 was dispersed in water so that the solid content concentration was 5.0% by mass.

<Example 10>
A fine fibrous cellulose-containing material of Example 10 was obtained in the same manner as Example 3 except that CNF1 was changed to CNF2.

<Comparative Example 1>
A fine fibrous cellulose-containing material of Comparative Example 1 was obtained in the same manner as in Example 1 except that CNF1 was dispersed in water so that the solid content concentration was 6.0% by mass.

<Comparative example 2>
A fine fibrous cellulose-containing material of Comparative Example 2 was obtained in the same manner as in Example 1 except that CNF1 was dispersed in water so that the solid content concentration was 0.008% by mass.

<Comparative Example 3>
CNF1 was dispersed in water so that the solid content concentration was 0.2% by mass. This dispersion was poured into a Teflon (registered trademark) petri dish and dried in an oven set at 60 ° C. for 120 minutes.

(Evaluation)
(Evaluation of feed properties)
The fine fibrous cellulose-containing material obtained in Examples and Comparative Examples was charged into a beaker (volume: 100 ml), and the mass W1 (g) was weighed. The beaker was gently rotated 180 ° C. downward to drop the powder. The mass W2 (g) of the fallen fine fibrous cellulose-containing material was weighed. The ratio of the mass of the fine fibrous cellulose-containing material dropped to the mass of the fine fibrous cellulose-containing material charged was calculated by the following formula, and the feed property was evaluated according to the following evaluation criteria. In addition, in this-application specification, that feed property is favorable means that it is excellent in the fluidity | liquidity of a fine fibrous cellulose containing material.
Feedability (%) = W2 / W1 × 100
<Feeding evaluation criteria>
◎: 95% or more ○: 80% or more, less than 95% ×: less than 80%

  The fine fibrous cellulose-containing material obtained in the examples was excellent in feedability. On the other hand, it can be seen that the fine fibrous cellulose-containing material obtained in the comparative example has poor feedability and does not have preferable properties. In Comparative Example 1, the average particle size of the obtained fine fibrous cellulose-containing material was large, and the feed property was inferior. Moreover, in the comparative example 2, the obtained fine fibrous cellulose containing material refined | miniaturized and feed property was inferior. Comparing Comparative Example 3 and Examples, it can be seen that the method of the fine fibrous cellulose-containing material granulated by the spray drying method is excellent in feed property.

  In this invention, the fine fibrous cellulose containing material excellent in fluidity | liquidity (feed property) can be manufactured.

2 Slurry tank 4 Pump 6 Pressurized air generator 10 Drying furnace 12 Inlet temperature sensor 14 Outlet temperature sensor 20 Sprayer 30 Hot air generator 40 Collector 50 Recovery tank 100 Spray dryer

Claims (6)

A step of dispersing a fine fibrous cellulose and a metal component in water to obtain a slurry;
The slurry includes a step of spray drying using a spray drier,
Content of the said fine fibrous cellulose in the said slurry is 0.009-5.8 mass% with respect to the total mass of the said slurry,
The microfibrous cellulose possess an ionic substituent,
Content of the said metal component in the said slurry is a manufacturing method of the fine fibrous cellulose containing material which is 1-20 mass% with respect to the total mass of the said fine fibrous cellulose .   The method for producing a fine fibrous cellulose-containing material according to claim 1, wherein the content of the fine fibrous cellulose in the slurry is 0.009 to 2.5 mass% with respect to the total mass of the slurry. The method for producing a fine fibrous cellulose-containing material according to claim 1 or 2 , wherein the ionic substituent is an anionic group. The method for producing a fine fibrous cellulose-containing material according to claim 3 , wherein the anionic group is at least one selected from a phosphoric acid group, a carboxyl group, and a sulfone group. Production method of the fine fibrous cellulose, fine fibrous cellulose-containing product according to any one of claims 1 to 4 having an ionic substituent 0.1~3.5mmol / g. The water content of the said fine fibrous cellulose containing material is 20 mass% or less, The manufacturing method of the fine fibrous cellulose containing material of any one of Claims 1-5 .

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