JP6504094B2 - Fine fibrous cellulose content - Google Patents

Description

  The present invention relates to a fine fibrous cellulose-containing material excellent in fine particle dispersibility.

  BACKGROUND ART In recent years, materials using renewable natural fibers have attracted attention due to substitution of petroleum resources and heightened environmental awareness. Among natural fibers, fibrous cellulose with a fiber diameter of 10 to 50 μm, particularly fibrous cellulose (pulp) derived from wood, has been widely used mainly as a paper product. In addition, as fibrous cellulose, fine fibrous cellulose having a fiber diameter of 1 μm or less is also known.

  The aqueous suspension or dispersion of fibrous cellulose usually contains several times to several hundreds times as much solvent as fibrous cellulose. Treating such an aqueous suspension or dispersion as it is has the problems of increased storage space and increased storage and transportation costs. Therefore, it has been attempted to prepare cellulose concentrates.

  For example, Patent Document 1 describes a method of treating an aqueous gel of nanofibrillar cellulose by removing water from the aqueous gel using an organic solvent miscible with water. In this method, the aqueous gel is introduced in a controlled manner into an organic solvent so as to maintain the aqueous gel as a separate phase and to form a physical entity comprising nanofibrillar cellulose in the separate phase, exchanging water with the organic solvent , A method of separating physical entities from organic solvents. Patent Document 2 describes a bacterial cellulose concentrate characterized by containing undegraded bacterial cellulose in a range of 10% by weight or more and less than 75% by weight.

  Patent Document 3 discloses a cellulose fiber suspension comprising a cellulose fiber, a polyvalent metal and a volatile base, wherein the cellulose fiber has an average fiber diameter of 200 nm or less and the carboxyl group content of the cellulose is 0.1 to 2 mmol / g. A suspension has been described. Patent Document 4 describes a method for producing a dry solid of anion-modified cellulose nanofibers, which is characterized in that the pH of the aqueous suspension of anion-modified cellulose nanofibers is adjusted to 9 to 11, and then dehydration and drying are performed. It is done.

Japanese Patent Application Publication No. 2014-508228 JP-A-9-316102 JP, 2010-168573, A JP, 2015-134873, A

  As mentioned above, Patent Documents 1 to 4 describe the preparation of a cellulose concentrate. However, when using a concentrate of fine fibrous cellulose, in particular, as a thickener, the inventors of the present invention have a concern that the dispersibility of fine particles (such as titanium oxide) in the aqueous medium containing the fine fibrous cellulose may be reduced. I paid attention. Studies from the above point of view regarding the concentration of fine fibrous cellulose have not been sufficiently conducted so far.

  The present invention has been made in view of the above problems. The problem to be solved by the present invention is to provide a fine fibrous cellulose-containing substance in which the dispersibility of the fine particles in the aqueous medium containing fine fibrous cellulose is good.

  The present inventors diligently studied to solve the above problems. As a result, by setting the mass ratio of the organic solvent content to the water content in the fine fibrous cellulose-containing substance within a predetermined range, the dispersibility of the fine particles in the aqueous medium containing the fine fibrous cellulose is improved. I found that I could do it. The present invention has been completed based on these findings.

That is, according to the present invention, the following inventions are provided.
(1) A fine fibrous cellulose-containing material comprising fine fibrous cellulose, an organic solvent and water, wherein the content of the fine fibrous cellulose is 5% by mass or more, and the content C1 of the organic solvent and the above The fine fibrous cellulose-containing material whose mass ratio C1 / C2 with the content C2 of water is 1 or more and 100 or less.
(2) The fine fibrous cellulose-containing material according to (1), wherein the organic solvent is isopropyl alcohol.
(3) The fine fibrous cellulose containing material as described in (1) or (2) whose said mass ratio C1 / C2 is 1 or more and 20 or less.
(4) The fine fibrous cellulose content thing in any one of (1) to (3) whose content of fine fibrous cellulose is 5 to 98 mass%.
(5) The fine fibrous cellulose-containing substance according to any one of (1) to (4), wherein the fine fibrous cellulose has an ionic substituent.
(6) The fine fibrous cellulose-containing substance according to any one of (1) to (5), wherein the fine fibrous cellulose has a phosphate group.
(7) The fine fibrous cellulose-containing substance according to any one of (1) to (6), wherein the amount of phosphoric acid groups in the fine fibrous cellulose is 0.5 mmol / g or more.
(8) The fine fibrous cellulose-containing material according to any one of (1) to (7), wherein the haze value of the following sample is 20% or less:
However, the said sample is a sample which added the said fine fibrous cellulose containing material in pure water so that solid content concentration might be 0.4 mass%, and was stirred on 1500 rpm and the conditions for 5 minutes by the disperser. .
(9) The fine fibrous cellulose-containing material according to any one of (1) to (8), which is in the form of powdery particles.

  The fine fibrous cellulose-containing substance of the present invention is excellent in the dispersibility of the fine particles in the aqueous medium containing the fine fibrous cellulose.

FIG. 1 shows the relationship between the amount of NaOH added to the fiber material and the electrical conductivity.

  “Parts” and “%” represent proportions based on mass (parts by mass, mass%) unless otherwise specified. Values for the mass of fibers such as cellulose are based on bone dry mass (solids) unless otherwise stated. Also, the numerical range "X to Y" includes the values at both ends, unless otherwise specified. "A or / and B" refers to at least one of A and B unless otherwise specified, and may be A alone or B alone, or both A and B. It means that it may be.

<Fiberous cellulose material>
The fibrous cellulose raw material for obtaining fibrous cellulose is not particularly limited, but it is preferable to use pulp in terms of availability and low cost. The pulp is selected from wood pulp, non-wood pulp and deinked pulp. Examples of wood pulp include hardwood kraft pulp (LBKP), softwood kraft pulp (NBKP), sulfite pulp (SP), soda pulp (AP), unbleached kraft pulp (UKP), oxygen bleached kraft pulp (OKP), and dissolving Chemical pulp, such as pulp (DP), etc. are mentioned. Also, semi-chemical pulp such as semi-chemical pulp (SCP), chemiground wood pulp (CGP), mechanical pulp such as ground pulp (GP), thermo-mechanical pulp (TMP, BCTMP), etc. may be mentioned, but not particularly limited. . Non-wood pulps include cotton-based pulps such as cotton linters and cotton lint, non-wood-based pulps such as hemp, wheat straw and bagasse, celluloses isolated from ascidians and seaweeds, chitin, chitosan and the like . Examples of the deinked pulp include, but not particularly limited to, deinked pulp made from waste paper. The pulp of this embodiment may be used singly or in combination of two or more. Among the above-mentioned pulps, wood pulps containing cellulose and deinked pulps are preferable in terms of availability. Among wood pulps, chemical pulp has a large cellulose ratio, so the yield of fine fibrous cellulose is high at the time of fiber refining (fibrillation), and decomposition of cellulose in the pulp is small, and fine fibers of long fibers having a large axial ratio Although it is preferable at the point from which fibrous cellulose is obtained, it does not specifically limit. Among them, kraft pulp and sulfite pulp are most preferably selected, but are not particularly limited. A sheet containing fine fibrous cellulose of long fibers having a large axial ratio can obtain high strength.

<Ionic Substituent>
The fine fibrous cellulose used in the present invention preferably has an ionic substituent, but is not particularly limited thereto.
The ionic substituent may be either an anionic substituent or a cationic substituent, preferably an anionic substituent.

  Although the method to introduce | transduce an anionic substituent into fibrous cellulose is not specifically limited, For example, the oxidation process or the process by the compound which can form a covalent bond with the functional group in cellulose, etc. are mentioned.

  The oxidation treatment is a treatment to convert a hydroxy group in cellulose into an aldehyde group or a carboxy group. Examples of the oxidation treatment include TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl radical) oxidation treatment and treatment with various oxidizing agents (sodium chlorite, ozone and the like). Examples of the oxidation treatment include, but are not particularly limited to, the methods described in Biomacromolecules 8, 2485-2491, 2007 (Saito et al.).

  The treatment with the compound can be carried out by introducing the above-described substituent into the fiber material by mixing the dry or wet fiber material with a compound that reacts with the fiber material. A heating method is particularly effective to promote the reaction upon introduction. Although the heat processing temperature in introduction of a substituent is not specifically limited, It is preferable that it is a temperature zone which thermal decomposition, hydrolysis, etc. of this fiber raw material do not occur easily. For example, from the viewpoint of the thermal decomposition temperature of cellulose, the temperature is preferably 250 ° C. or less, and from the viewpoint of suppressing the hydrolysis of cellulose, the heat treatment is preferably performed at 100 to 170 ° C.

The compound that reacts with the fiber material is not particularly limited as long as fine fibers can be obtained and anionic substituents can be introduced.
When an anionic substituent is introduced, examples of the compound that reacts with the fiber material include a compound having a group derived from phosphoric acid, a compound having a group derived from carboxylic acid, a compound having a group derived from sulfuric acid, and a sulfonic acid-derived compound. The compound etc. which have group are mentioned. Preferred are compounds having at least one selected from the group consisting of a group derived from phosphoric acid, a group derived from carboxylic acid and a group derived from sulfuric acid from the viewpoint of ease of handling and reactivity with fibers. It is more preferable that these compounds form an ester or / and an ether with a fiber, but it is not particularly limited.

  Although the introduction amount (by titration method) of the substituent in the anionic substituent-introduced fiber is not particularly limited, 0.005α to 0.11α is preferable per 1 g (mass) of fiber, and 0.01α to 0.08α is more preferable. When the introduction amount of the substituent is 0.005α or more, the fiber material can be easily miniaturized (fibrillated), and when the introduction amount of the substituent is 0.11α or less, the dissolution of the fiber can be suppressed. Here, α is an amount (unit: mmol / g) in which a functional group to which a compound reactive with the fiber material can react, such as a hydroxyl group or an amino group, is contained per 1 g of the fiber material.

In addition, the measurement of the introduction amount (titration method) of the substituent on the fiber surface can be carried out by the following method, unless otherwise specified:
A fine fiber-containing slurry containing a solid content of about 0.04 g in bone dry mass is fractionated and diluted to about 50 g with ion exchanged water. While stirring this solution, measure the change of the value of electric conductivity when 0.01 N aqueous sodium hydroxide solution is added dropwise, and the amount of 0.01 N aqueous sodium hydroxide solution dropped when the value becomes minimum. , And the dropping amount at the titration end point. The amount of substituents X on the cellulose surface is represented by X (mmol / g) = 0.01 (mol / l) × V (ml) / W (g). Here, V: The dropping amount (ml) of a 0.01 N aqueous solution of sodium hydroxide, and W: solid content (g) contained in the fine fibrous cellulose-containing slurry.

  In conductivity titration, the addition of alkali gives the curve shown in FIG. At the beginning, the electrical conductivity drops sharply (hereinafter referred to as "first region"). Thereafter, the conductivity starts to rise slightly (hereinafter referred to as "the second region"). After that, the increment of conductivity increases (hereinafter, referred to as "third region"). That is, three regions appear. Among them, 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 Become 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, since the amount of strongly acidic groups is the same as the amount of phosphorus atoms regardless of the presence or absence of condensation, the amount of introduction of phosphoric acid groups (or the amount of phosphoric acid groups) or the amount of introduction of substituents (or the amount of substitution groups) When said, it represents the amount of strongly acidic groups.

  When the substituent to be introduced is at least one selected from the group consisting of a group derived from phosphoric acid, a group derived from carboxylic acid, and a group derived from sulfuric acid, the amount of introduced substituent is not particularly limited. It can be set to 001 to 5.0 mmol / g. It is good also as 0.005-4.0 mmol / g, and good also as 0.01-2.0 mmol / g. When the substituent introduced is a phosphate group, the amount of the phosphate group in the fine fibrous cellulose is preferably 0.5 mmol / g or more, and is 0.5 to 5.0 mmol / g. More preferably, 0.5 to 2.0 mmol / g is more preferable.

  When a compound having a group derived from phosphoric acid is used as the compound that reacts with the fiber raw material, it is not particularly limited, but it is composed of phosphoric acid, polyphosphoric acid, phosphorous acid, phosphonic acid, polyphosphonic acid or salts or esters thereof It is at least one selected from the group. Among these, compounds having a phosphoric acid group are preferable because they are low in cost, easy to handle, and can further improve the refining (disintegration) efficiency by introducing a phosphoric acid group into the fiber raw material, but are not particularly limited. .

  The compound having a phosphoric acid group is not particularly limited, but includes phosphoric acid, lithium dihydrogen phosphate which is a lithium salt of phosphoric acid, dilithium hydrogen phosphate, trilithium phosphate, lithium pyrophosphate and lithium polyphosphate . Furthermore, sodium dihydrogen phosphate, disodium hydrogen phosphate, trisodium phosphate, sodium pyrophosphate and sodium polyphosphate which are sodium salts of phosphoric acid can be mentioned. Furthermore, potassium dihydrogen phosphate, dipotassium hydrogen phosphate, tripotassium phosphate, potassium pyrophosphate and potassium polyphosphate which are potassium salts of phosphoric acid can be mentioned. Furthermore, ammonium dihydrogen phosphate, diammonium hydrogen phosphate, triammonium phosphate, ammonium pyrophosphate, ammonium polyphosphate and the like which are ammonium salts of phosphoric acid can be mentioned.

  Among these, phosphoric acid, a sodium salt of phosphoric acid, a potassium salt of phosphoric acid, and an ammonium salt of phosphoric acid are preferable from the viewpoint of high efficiency of phosphoric acid group introduction and industrially easy application, sodium dihydrogenphosphate And disodium hydrogen phosphate are more preferable, but not particularly limited.

  Moreover, although it is preferable to use a compound as aqueous solution from the uniformity of reaction, and the introduction | transduction efficiency of group derived from phosphoric acid being high, it is not specifically limited. The pH of the aqueous solution of the compound is not particularly limited, but is preferably 7 or less because the efficiency of introducing a phosphoric acid group is high. Although the pH of 3 to 7 is particularly preferable from the viewpoint of suppressing the hydrolysis of fibers, it is not particularly limited.

  When a compound having a group derived from a carboxylic acid is used as a compound which reacts with a fiber material, it is not particularly limited, but a compound having a carboxy group, an acid anhydride of a compound having a carboxy group and derivatives thereof It is at least one selected.

  The compound having a carboxy 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. .

  The acid anhydride of the compound having a carboxy 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, itaconic anhydride and the like. Be

  Although it does not specifically limit as a derivative of the compound which has a carboxy group, The imidate of the acid anhydride of the compound which has a carboxy group, The derivative of the acid anhydride of the compound which has a carboxy group is mentioned. Although it does not specifically limit as an imide of the acid anhydride of the compound which has a carboxy group, The imidate of dicarboxylic acid compounds, such as maleimide, a succinimide, and a phthalimide, is mentioned.

  The acid anhydride derivative of the compound having a carboxy group is not particularly limited. For example, at least a part of hydrogen atoms of an acid anhydride of a compound having a carboxy group such as dimethylmaleic anhydride, diethylmaleic anhydride, diphenylmaleic anhydride and the like have a substituent (for example, an alkyl group, a phenyl group, etc. And the like.

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

  When a compound having a group derived from sulfuric acid is used as the compound that reacts with the fiber raw material, it is not particularly limited, but it is at least one selected from the group consisting of sulfuric anhydride, sulfuric acid and salts and esters thereof. Among these, sulfuric acid is preferable because it is low in cost and sulfuric acid is introduced into the fiber raw material to further improve the refining (disintegration) efficiency, although not particularly limited.

  When a cationic substituent is introduced, examples of the compound that reacts with the fiber raw material include compounds having a group derived from an onium salt such as ammonium salt, phosphonium salt, sulfonium salt and the like. Specifically, compounds having a group containing ammonium such as primary ammonium salt, secondary ammonium salt, tertiary ammonium salt, quaternary ammonium salt and the like, phosphonium and sulfonium can be mentioned. Groups derived from quaternary ammonium salts and groups derived from phosphonium salts can be mentioned because of ease of handling and reactivity with fibers. The measurement of the introduction amount of the cationic substituent can be performed, for example, using elemental analysis or the like.

In the present embodiment, a cationic substituent can be introduced into the fiber material, for example, by adding a cationizing agent and an alkali compound to the fiber material and causing a reaction. As the cationizing agent, one having a quaternary ammonium group and a group that reacts with the hydroxy group of cellulose can be used. Examples of the group that reacts with the hydroxy group of cellulose include an epoxy group, a functional group having a halohydrin structure, a vinyl group, a halogen group and the like.
Specific examples of the cationizing agent include glycidyl trialkyl ammonium halides such as glycidyl trimethyl ammonium chloride, 3-chloro-2-hydroxypropyl trimethyl ammonium chloride, and compounds of the halohydrin type thereof.

  The alkali compound used in the cationization step contributes to the promotion of the cationization reaction. The alkali compound may be an inorganic alkali compound or an organic alkali compound.

As an inorganic alkali compound, an alkali metal hydroxide or an alkaline earth metal hydroxide, an alkali metal carbonate or an alkaline earth metal carbonate, an alkali metal phosphate or an alkaline earth metal phosphate Salt is mentioned.
Examples of hydroxides of alkali metals include lithium hydroxide, sodium hydroxide and potassium hydroxide. Calcium hydroxide is mentioned as a hydroxide of alkaline-earth metal.
Examples of carbonates of alkali metals include lithium carbonate, lithium hydrogen carbonate, potassium carbonate, potassium hydrogen carbonate, sodium carbonate and sodium hydrogen carbonate. Examples of carbonates of alkaline earth metals include calcium carbonate and the like.
Examples of the alkali metal phosphate include lithium phosphate, potassium phosphate, trisodium phosphate, and disodium hydrogen phosphate. Examples of the alkaline earth metal phosphate include calcium phosphate and calcium hydrogen phosphate.

Examples of the organic alkali compound include ammonia, aliphatic amines, aromatic amines, aliphatic ammonium, aromatic ammonium, heterocyclic compounds and their hydroxides, carbonates and phosphates, and the like. Can be mentioned.
Ammonia, hydrazine, methylamine, ethylamine, diethylamine, triethylamine, propylamine, dipropylamine, butylamine, diaminoethane, diaminopropane, diaminobutane, diaminopentane, diaminohexane;
Cyclohexylamine, aniline, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, benzyltrimethylammonium hydroxide;
Pyridine, N, N-dimethyl-4-aminopyridine;
Ammonium carbonate, ammonium hydrogencarbonate, diammonium hydrogen phosphate etc.
The above-mentioned alkali compounds may be used alone or in combination of two or more.

  Among the above-mentioned alkali compounds, sodium hydroxide and potassium hydroxide are preferable because the cationization reaction is more likely to occur and the cost is low. The amount of the alkali compound varies depending on the type of the alkali compound, but is, for example, in the range of 1 to 10% by mass with respect to the dry-pulp mass.

  The cationizing agent and the alkali compound are preferably made into a solution because they can be easily added to the pulp. The solvent to be used for solution may be either water or an organic solvent, but a polar solvent (a polar organic solvent such as water or alcohol) is preferable, and an aqueous solvent containing at least water is more preferable.

  In the present production method, it is preferable to set the amount of solvent per 1 g of pulp absolute dry weight at the start of the cationization reaction to 5 to 150 mmol. The amount of substance of the solvent is more preferably 5 to 80 mmol, further preferably 5 to 60 mmol. In order to make the content of the pulp at the time of cationization reaction into the above-mentioned range, for example, a pulp having a high content (that is, a small amount of water) may be used. In addition, it is preferable to reduce the amount of solvent contained in the solution of the cationizing agent and the alkali compound.

  The reaction temperature in the cationization step is preferably in the range of 20 to 200 ° C., and more preferably in the range of 40 to 100 ° C. If the reaction temperature is above the lower limit value, sufficient reactivity can be obtained, and if it is below the upper limit value, the reaction can be easily controlled. It also has the effect of suppressing the coloration of the pulp after reaction. The time of the cationization reaction varies depending on the type of pulp and cationizing agent, the pulp content, the reaction temperature and the like, but is usually in the range of 0.5 to 3 hours.

  The cationization reaction may be carried out in a closed system or in an open system. In addition, the solvent may be evaporated during the reaction, and the amount of the solvent per 1 g of pulp absolute dry weight at the end of the reaction may be lower than that at the start of the reaction.

  By introducing an ionic substituent into the fiber material, the dispersibility of the fiber in the solution can be improved, and the disaggregation efficiency can be enhanced.

<Fine treatment of fibrous cellulose>
A fine fibrous cellulose slurry can be produced by subjecting fibrous cellulose to a refining (fibrillation) treatment.

During the micronization treatment, fibrous cellulose is dispersed in a solvent.
Specific examples of the solvent include water, an organic solvent alone, and a mixture of water and an organic solvent. The organic solvent is not particularly limited as long as the intended relative dielectric constant can be secured. For example, alcohols, polyhydric alcohols, ketones, ethers, dimethylsulfoxide (DMSO), dimethylformamide (DMF), dimethylacetamide (DMAc) and the like can be mentioned. Examples of alcohols include methanol, ethanol, n-propanol, isopropanol, n-butanol, t-butyl alcohol and the like. Examples of polyhydric alcohols include ethylene glycol and glycerin. Examples of ketones include acetone and methyl ethyl ketone. As ethers, diethyl ether, tetrahydrofuran, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono n-butyl ether, ethylene glycol mono t-butyl ether, etc. may be mentioned. The organic solvent may be used alone or in combination of two or more. Among the above, preferably, the solvent is water.

  The dispersion concentration of fibrous cellulose in the solvent is preferably 0.1 to 20% by mass, and more preferably 0.5 to 10% by mass. If the dispersion concentration is 0.1% by mass or more, the efficiency of the defibration treatment is improved, and if it is 20% by mass or less, clogging in the defibration treatment apparatus can be prevented.

  The defibration treatment apparatus is not particularly limited. For example, high-speed fibrillation machines, grinders (miller mills), high-pressure homogenizers and ultra-high pressure homogenizers, Creamix, high-pressure collision mills, ball mills, bead mills, disc refiners, conical refiners, etc. may be mentioned. In addition, a twin-screw kneader, a vibration mill, a homomixer under high-speed rotation, an ultrasonic dispersion machine, a beater, an apparatus for wet grinding, and the like can be appropriately used.

  By the refining treatment, a fine fibrous cellulose slurry is obtained. The average fiber width of the obtained fine fibrous cellulose is not particularly limited, but may be, for example, 1 to 1000 nm, preferably 2 to 1000 nm, more preferably 2 to 500 nm, and still more preferably 3 to 100 nm. When the average fiber width of the fine fiber is 1 nm or more, the dissolution of molecules in water is suppressed, so that the physical properties (strength, rigidity, and dimensional stability) as the fine fiber are sufficiently expressed. On the other hand, when the average fiber width is 1000 nm or less, the characteristics (high transparency, high elastic modulus, low linear expansion coefficient, flexibility) as fine fibers are easily exhibited. In addition, although the obtained fine fibrous cellulose dispersion liquid may contain fibrous cellulose whose fiber width | variety exceeds 1000 nm, it is more preferable not to contain fibrous cellulose whose fiber width | variety exceeds 1000 nm. The fine fibrous cellulose is, for example, monofibrillar cellulose having a fiber width of 1000 nm or less.

  In applications where transparency is required for fine fibers, if the average fiber width is 30 nm or less, it approaches 1/10 of the wavelength of visible light, and when combined with a matrix material, refraction and scattering of visible light occur at the interface. There is a tendency to be hard to produce and to obtain a highly transparent one. Therefore, the average fiber width is not particularly limited, but 2 nm to 30 nm is preferable, and 2 to 20 nm is more preferable. Composites obtained from such fine fibers as described above generally have high strength because they form a compact structure, and high transparency can also be obtained because there is little scattering of visible light.

The average fiber width is measured as follows. A fine fiber-containing slurry having a concentration of 0.05 to 0.1% by mass is prepared, and the slurry is cast on a hydrophilized carbon film-coated grid to obtain a sample for TEM observation. In the case of containing wide fibers, 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, 20000 times or 50000 times depending on the width of the fiber to be constructed. However, the sample, observation conditions and magnification are adjusted to satisfy the following conditions.
(1) One straight line X is drawn at an arbitrary position in the observation image, and 20 or more fibers cross the straight line X.
(2) Draw a straight line Y intersecting perpendicularly with the straight line in the same image, and 20 or more fibers cross the straight line Y.
With respect to the observation image satisfying the above conditions, the width of the fiber intersecting with the straight line X and the straight line Y is visually read. Thus, three or more sets of images of at least non-overlapping surface portions are observed, and for each image, the width of the fiber intersecting the straight line X and the straight line Y is read. Thus, a fiber width of at least 20 x 2 x 3 = 120 is read. The average fiber width is the average value of the fiber widths read in this manner.

  The fiber length is not particularly limited, but is preferably 0.1 μm or more. If the fiber length is 0.1 μm or more, it is preferable in that the tear strength of the sheet is sufficient when the sheet described later is manufactured. The fiber length can be determined from image analysis of TEM, SEM, AFM. The said fiber length is a fiber length which occupies 30 mass% or more of a fine fiber.

  The axial ratio of fibers (fiber length / fiber width) is not particularly limited, but is preferably in the range of 20 to 10,000. An axial ratio of 20 or more is preferable in that the fine fiber-containing sheet is easily formed. If the axial ratio is 10000 or less, it is preferable in that the slurry viscosity is lowered.

  By the refining treatment, a fine fibrous cellulose slurry is obtained. The concentration of the fine fibrous cellulose here is, for example, 0.1 to 20% by mass, and may be 0.2 to 10% by mass, or may be 0.5 to 10% by mass.

<Dehydration>
By subjecting the fine fibrous cellulose slurry obtained above to dehydration treatment, it is possible to prepare a fine fibrous cellulose-containing substance having a content of fine fibrous cellulose of 5% by mass or more according to the present invention. That is, according to the present invention, the step of gelling a diluent containing fine fibrous cellulose, and the step of obtaining a concentrate containing fine fibrous cellulose from the gelled product obtained above, the fine fibrous form of the present invention Also provided is a method of producing a cellulose content. If desired, the step of heating the concentrate may be provided after the step of obtaining the concentrate containing fine fibrous cellulose from the gelled product.

  The above-mentioned gelation step can be performed by adding an organic solvent to the diluted solution containing fine fibrous cellulose, but is not particularly limited. Specific examples of the organic solvent used here will be described later. The step of obtaining a concentrate containing fine fibrous cellulose from the gelled product can be carried out by squeezing after filtering the gelled product, but it is not particularly limited. Although the process of heating a concentrate can be performed by heating by oven etc., it is not specifically limited.

  In the present invention, it is preferable to carry out a filtration treatment after gelation by adding a solvent to the diluted solution containing fine fibrous cellulose, but it is not particularly limited. Moreover, although it is preferable to perform a compression process after a filtration process process, it is not specifically limited. By providing the compression step, the water content in the concentrate can be adjusted to a preferable range.

As a device for squeezing, a general press device such as a belt press, a screw press, a filter press can be used, and the device is not particularly limited.
The filter medium to be used is not particularly limited, but stainless steel, filter paper, polypropylene, nylon, polyethylene, polyester or the like can be used. It is preferably made of polypropylene because an acid may be used.
The lower the air permeability of the filter medium, the higher the yield. Therefore, it is 30 cm 3 / cm 2 · sec or less, more preferably 10 cm 3 / cm 2 · sec or less, still more preferably 1 cm 3 / cm 2 · sec or less.
If the concentration of the raw material to be subjected to the squeezing step is low, the dehydration filtrate increases and the dehydrating step takes longer, so that it is 0.5% or more, preferably 1% or more, more preferably 2% or more. .
The pressure at the time of pressing is 0.2 MPa or more, more preferably 0.4 MPa or more.

  In the present invention, a drying step may be further provided. The drying step is preferably an oven drying step, and for example, drying is preferably performed in an oven set at 30 to 70 ° C. for 1 to 60 minutes.

<Fine fibrous cellulose content>
The fine fibrous cellulose-containing material of the present invention is a fine fibrous cellulose-containing material comprising fine fibrous cellulose, an organic solvent and water, wherein the content of the fine fibrous cellulose is 5% by mass or more, The mass ratio C1 / C2 of the content C1 of the organic solvent and the content C2 of the water is 1 or more and 100 or less.

The above mass ratio C1 / C2 is preferably 1 or more and 50 or less, more preferably 1 or more and 30 or less, and still more preferably 1 or more and 20 or less.
The above mass ratio C1 / C2 can be controlled, for example, by appropriately adjusting the method of concentrating fine fibrous cellulose. In the present embodiment, the above mass ratio can be adjusted, for example, by adjusting the amount of the organic solvent added in the dehydration step, but is not particularly limited.

The ratio of the amount of water to the amount of organic solvent in gelation by adding an organic solvent to a diluted solution containing fine fibrous cellulose in water is the ratio of the organic solvent in the fine fibrous cellulose-containing material of the present invention It corresponds to the mass ratio C1 / C2 of the content C1 and the content C2 of water.
The mass ratio of the fine fibrous cellulose-containing substance is not particularly limited, and for example, the following method can be used. The fine fibrous cellulose content is dried, and the bone dry weight is measured to determine the total amount A of water and organic solvent. Next, the fine fibrous cellulose-containing substance is dispersed in water, then sodium chloride is added, and a gas phase obtained by bubbling nitrogen gas in a water bath at 85 ° C. The methyl solution is absorbed, and the absorption liquid is subjected to GC / MS-SIM to quantify the amount of organic solvent C1. The water content C2 is calculated from A-C1.

  In the present invention, by setting the mass ratio C1 / C2 of the content C1 of the organic solvent to the content C2 of the water with respect to the fine fibrous cellulose-containing substance to 1 or more and 100 or less, in the aqueous medium containing the fine fibrous cellulose Succeeded in improving the dispersibility of fine particles in

  In the present invention, the content of the fine fibrous cellulose is 5% by mass or more. The upper limit of the content of the fine fibrous cellulose is not particularly limited, but the content of the fine fibrous cellulose is preferably 99% by mass or less, more preferably 98% by mass or less. The content of the fine fibrous cellulose may be 90% by mass or less, 80% by mass or less, 70% by mass or less, 60% by mass or less, 50% by mass or less, or 40% by mass or less. The content of the fine fibrous cellulose may be 10% by mass or more, 15% by mass or more, or 20% by mass or more.

  The fine fibrous cellulose-containing substance of the present invention contains the organic solvent by using the organic solvent or the mixture of the organic solvent and water in the dehydration treatment. Examples of the organic solvent include, but are not particularly limited to, alcohols, polyhydric alcohols, ketones, ethers, dimethylsulfoxide (DMSO), dimethylformamide (DMF), dimethylacetamide (DMAc) and the like. As alcohols, methanol, ethanol, n-propanol, isopropanol, n-butanol, t-butyl alcohol etc. are mentioned. Examples of polyhydric alcohols include ethylene glycol and glycerin. Examples of ketones include acetone and methyl ethyl ketone. As ethers, diethyl ether, tetrahydrofuran, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono n-butyl ether, ethylene glycol mono t-butyl ether, etc. may be mentioned. The organic solvent may be used alone or in combination of two or more. Among the above, the solvent is preferably an alcohol or a mixture of an alcohol and water. The solvent is more preferably isopropyl alcohol.

The fine fibrous cellulose-containing material of the present invention is added to pure water so that the solid concentration becomes 0.4 mass%, and the haze value of a sample stirred at 1500 rpm for 5 minutes with a disperser is 20% It is preferable that it is the following. It is not particularly limited. The lower limit of the haze value is not particularly limited, but is preferably 0.1% or more, more preferably 0.2% or more, and still more preferably 0.5% or more.
The disperser is not particularly limited as long as it is a common disperser, and a stirrer such as a homomixer or a three-one motor is used.

  The form of the fine fibrous cellulose-containing substance of the present invention is not particularly limited, but is preferably in the form of powder. Particulate refers to what consists of a powdery substance and / or a granular substance. Powdered substances are those smaller than particulate substances. Generally, the powdery substance refers to fine particles having a particle size of 1 nm or more and less than 0.1 mm, and the particulate substance refers to particles having a particle size of 0.1 to 10 mm, but is not particularly limited. In addition, powdery particles are not necessarily spherical. The particle diameter of the powdery particles in the present specification is a value measured using a laser diffraction scattering particle size distribution measuring device (Microtrac 3300 EXII, Nikkiso Co., Ltd.).

In the fibrillar cellulose-containing product of the present invention, the pH of the following sample is preferably 7 or more and 11 or less, more preferably the pH of the following sample is 8 or more and 10.5 or less, but it is not particularly limited. The said sample is a sample which added the said fine fibrous cellulose containing substance in pure water so that solid content concentration might be 0.4 mass%, and was stirred on 1500 rpm and the conditions for 5 minutes by the disperser.
When the pH of the sample is 7 or more, the counter ion of the functional group of the fine fibrous cellulose becomes a sodium ion, and the fine fibrous celluloses electrostatically repel each other to be easily dispersed in the solvent.
By setting the pH of the sample to 11 or less, the alkali concentration in the system can be suppressed, and the dispersibility of the fine fibrous cellulose in the solvent due to electrostatic repulsion can be improved.

<Redispersion of fine fibrous cellulose content>
A fine fibrous cellulose redispersion can be obtained by resuspending the fine fibrous cellulose content of the present invention in a solvent.

  The type of solvent used to obtain the fine fibrous cellulose inclusion is not particularly limited. Specific examples of the solvent include water, an organic solvent alone, and a mixture of water and an organic solvent. Examples of the organic solvent include alcohols, polyhydric alcohols, ketones, ethers, dimethylsulfoxide (DMSO), dimethylformamide (DMF), dimethylacetamide (DMAc) and the like. As alcohols, methanol, ethanol, n-propanol, isopropanol, n-butanol, t-butyl alcohol etc. are mentioned. Examples of polyhydric alcohols include ethylene glycol and glycerin. Examples of ketones include acetone and methyl ethyl ketone. As ethers, diethyl ether, tetrahydrofuran, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono n-butyl ether, ethylene glycol mono t-butyl ether, etc. may be mentioned. The organic solvent may be used alone or in combination of two or more. Among the above, the solvent is preferably a mixture of alcohols and water, a mixture of ethers and water, or a mixture of DMSO and water.

  Redispersion of the fine fibrous cellulose can be carried out by a conventional method. For example, the above-described solvent is added to the fine fibrous cellulose-containing substance of the present invention to prepare a solution containing fine fibrous cellulose, and the fine fibrous cellulose in the solution containing the fine fibrous cellulose Redispersion can be performed by the dispersing step.

  When adding a solvent to the fine fibrous cellulose-containing substance of the present invention to prepare a solution containing fine fibrous cellulose, the content of the fine fibrous cellulose is 0.1% by mass to 10% by mass with respect to the whole solution It is preferable to More preferably, the content of the fine fibrous cellulose is 0.2% by mass to 3% by mass with respect to the fine fibrous cellulose-containing liquid. If the content is 0.1% by mass or more, the dispersion stability of the fine fibrous cellulose will be high, and if the content is 10% by mass or less, the viscosity of the fine fibrous cellulose will not be too high, and the handling will be It becomes relatively easy. The fine fibrous cellulose content can be adjusted by the addition amount of the solvent, and the fine fibrous cellulose content decreases as the addition amount of the solvent increases.

  As a dispersion apparatus used for the process to which fine fibrous cellulose is disperse | distributed, the thing similar to the disintegration processing apparatus described in said <fine-ization processing of fibrous cellulose> can be used.

  The fine fibrous cellulose redispersion obtained as described above preferably has a fine fibrous cellulose concentration of 0.1% by mass or more, more preferably 0.5% by mass or more, and more preferably 1% by mass. % Or more, more preferably 3% by mass or more. Although the upper limit of the concentration of fine fibrous cellulose is not particularly limited, it is generally 10% by mass or less. When the concentration of the fine fibrous cellulose is in the above range, the handling at the time of coating becomes good, and the dispersion stability is excellent. The dispersibility can be evaluated by performing dispersion treatment with a homodisper or the like, visually observing the liquid immediately after that, and judging whether or not precipitation is observed.

<Other ingredients>
The fine fibrous cellulose-containing substance of the present invention may contain a surfactant. By including the surfactant, the surface tension can be reduced to improve the wettability to the process substrate, and the fine fibrous cellulose-containing sheet can be formed more easily.

  As surfactant, nonionic surfactant, anionic surfactant, and cationic surfactant can be used. When cellulose is anionic, nonionic surfactants and anionic surfactants are preferable, and when cellulose is cationic, nonionic surfactants and cationic surfactants are preferable.

  The fine fibrous cellulose-containing material of the present invention can also be prepared by mixing at least one or more types of fibers other than fine fibrous cellulose (hereinafter referred to as "additional fibers"). Examples of the additional fibers include, but are not particularly limited to, inorganic fibers, organic fibers, synthetic fibers and the like, semi-synthetic fibers, and regenerated fibers. Examples of inorganic fibers include, but are not limited to, glass fibers, rock fibers, metal fibers and the like. Examples of organic fibers include, but are not limited to, fibers derived from natural products such as cellulose, carbon fibers, pulp, chitin, chitosan and the like. Examples of synthetic fibers include, but are not limited to, nylon, vinylon, vinylidene, polyester, polyolefin (eg, polyethylene, polypropylene etc.), polyurethane, acrylic, polyvinyl chloride, aramid etc. Semi-synthetic fibers include, but are not limited to, acetate, triacetate, promix, and the like. Examples of the regenerated fiber include, but not limited to, rayon, cupra, polynozic rayon, lyocell, tencel and the like. The additional fibers can be subjected to treatments such as chemical treatment and defibration treatment as required. When the additional fiber is treated with chemical treatment or defibration treatment, it may be mixed with the fine fiber and then treated with chemical treatment, defibration treatment or the like, or the additional fiber may be chemically treated with disintegration treatment. It can be mixed with the fine fiber after being subjected to a treatment such as treatment. When the additional fiber is mixed, the addition amount of the additional fiber in the total amount of the fine fiber and the additional fiber is not particularly limited, but is preferably 50% by mass or less, more preferably 40% by mass or less, further preferably 30 It is less than mass%. Particularly preferably, it is at most 20% by mass.

  A hydrophilic polymer may be added to the fine fibrous cellulose-containing substance of the present invention. The hydrophilic polymer is not particularly limited. For example, polyethylene glycol, cellulose derivatives (hydroxyethyl cellulose, carboxyethyl cellulose, carboxymethyl cellulose etc.), casein, dextrin, starch, modified starch etc. may be mentioned. In addition, polyvinyl alcohol and modified polyvinyl alcohol (acetoacetylated polyvinyl alcohol and the like) can be mentioned. Furthermore, polyethylene oxide, polyvinyl pyrrolidone, polyvinyl methyl ether, polyacrylates, polyacrylamide, alkyl acrylate copolymer, urethane copolymer and the like can be mentioned.

  Also, instead of hydrophilic polymers, hydrophilic low molecular weight compounds can also be used. The hydrophilic low molecular weight compound is not particularly limited. For example, glycerin, erythritol, xylitol, sorbitol, galactitol, mannitol, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, butylene glycol and the like can be mentioned. The addition amount in the case of adding a hydrophilic polymer or a hydrophilic low molecular weight compound is not particularly limited. For example, the amount is 1 to 200 parts by mass, preferably 1 to 150 parts by mass, more preferably 2 to 120 parts by mass, and still more preferably 3 to 100 parts by mass with respect to 100 parts by mass of the solid content of the fine fiber.

<Use>
The use of the fine fibrous cellulose-containing material according to the present invention is not particularly limited. As an example, it can be formed into a film using a fine fibrous cellulose redispersion slurry, and can be used as various films. As another example, the fine fibrous cellulose redispersion slurry can be used as a thickener for various applications (eg, additives to food, cosmetics, cement, paint, ink, etc.). Furthermore, it can be used as a reinforcing material by mixing with a resin or an emulsion.

  The present invention will be more specifically described by the following examples, but the scope of the present invention is not limited by the following examples.

Production Example 1: Production of fine fibrous cellulose (CNF) A phosphorylation reagent is prepared by dissolving 100 g of urea, 55.3 g of sodium dihydrogen phosphate dihydrate, and 41.3 g of disodium hydrogen phosphate in 109 g of water. did.
The dried softwood bleached kraft pulp pickup sheet was treated with a cutter mill and a pin mill to give flocculent fibers. 100 g of this cotton-like fiber was taken at bone dry mass, and a phosphation reagent was evenly sprayed with a spray, and then it was mixed by hand to obtain a drug-impregnated pulp.

The resulting chemical-impregnated pulp was heated for 160 minutes with a damper-equipped air drier heated to 140 ° C. to obtain a phosphorylated pulp.
100 g of the resulting phosphorylated pulp is taken, and 10 L of ion exchanged water is poured, stirred and uniformly dispersed, and then filtered and dewatered to obtain a dewatered sheet, which is repeated twice. The dewatering sheet obtained here is referred to as dewatering sheet A.

  Next, the dehydrated sheet obtained above was diluted with 10 L of ion exchanged water, and while stirring, a 1N aqueous solution of sodium hydroxide was added little by little to obtain a pulp slurry having a pH of 12 to 13.

Thereafter, the pulp slurry is dewatered to obtain a dewatered sheet, and then 10 L of ion-exchanged water is poured, and after stirring and uniformly dispersing, the step of dewatering by filtration is repeated twice to obtain the dewatered sheet.
After diluting with ion exchange water to a concentration of 0.5% by mass, disaggregation is carried out for 30 minutes under conditions of 21500 rotations / min using a disintegration processor (Clarix-2.2S manufactured by Emtechnics Co., Ltd.) It was processed to obtain CNF1, a fine fibrous cellulose.

-Amount of introduced substituent The introduced amount of phosphoric acid group was measured for the above-mentioned dehydrated sheet A by the following titration method.
[Measurement of amount of introduced substituent (amount of introduced phosphoric acid group)]
The substituent introduction amount is the introduction amount of the phosphate group to the fiber material, and the larger the value, the more phosphate groups are introduced. The amount of introduced substituent was measured by diluting the target fine fibrous cellulose with ion exchange water so that the content would be 0.2% by mass, and then treating with an ion exchange resin and titration using an alkali. In the treatment with ion exchange resin, 1/10 strongly acidic ion exchange resin (Amberjet 1024; Organo Corporation, conditioned) is added to a 0.2% by mass fibrous cellulose-containing slurry and shaken for 1 hour Did. Then, it poured on the mesh of 90 micrometers of openings, and the resin and the slurry were isolate | separated. In the titration using an alkali, the change in the value of electric conductivity exhibited by the slurry was measured while adding a 0.1 N aqueous solution of sodium hydroxide to the fibrous cellulose-containing slurry after ion exchange. That is, the amount of alkali (mmol) required in the first region of the curve shown in FIG. 1 was divided by the solid content (g) in the slurry to be titrated to obtain a substituent introduction amount (mmol / g).
The phosphoric acid group introduction amount was 1.54 mmol / g.

<Measurement of fiber width>
The fiber width of CNF1 was measured by the following method.
The supernatant liquid of the fibrillated pulp slurry was diluted with water to a concentration of 0.01 to 0.1% by mass and dropped onto a hydrophilized carbon grid film. After drying, it was stained with uranyl acetate and observed with a transmission electron microscope (JEOL-2000EX, manufactured by JEOL Ltd.). It was confirmed that CNF1 was a fine fibrous cellulose having a width of about 4 nm.

Example 1:
CNF1 was diluted to 0.4% by mass. To 100 mL of the diluted solution, 200 mL of isopropanol (IPA) was added to gel CNF1, filtered off, and squeezed with filter paper for 2 minutes to obtain a concentrate. The obtained concentrate was treated and milled for 1 minute with a mixer (BM-RE08-HA, manufactured by ZOJI).

Example 2:
CNF1 was diluted to 0.4% by mass. To 100 mL of the diluted solution, 100 mL of isopropanol was added to gel CNF1, filtered off, and squeezed with filter paper for 2 minutes to obtain a concentrate. The obtained concentrate was treated and milled for 1 minute with a mixer (BM-RE08-HA, manufactured by ZOJI).

Example 3:
A concentrate was obtained and milled as in Example 1 except that 2000 mL of isopropanol was added.

Example 4:
A concentrate was obtained and milled as in Example 1 except that 5000 mL of isopropanol was added.

Example 5:
A concentrate was obtained and milled as in Example 1 except that 10000 mL of isopropanol was added.

Example 6:
CNF1 was diluted to 0.4% by mass. To 100 mL of the diluted solution, 200 mL of isopropanol (IPA) was added to gel the CNF 1 and filtered off to obtain a concentrate. The obtained concentrate was treated and milled for 1 minute with a mixer (BM-RE08-HA, manufactured by ZOJI).

Example 7:
A concentrate was obtained and crushed in the same manner as in Example 1 except that the pressing time was 1 minute.

Example 8:
CNF1 was diluted to 0.4% by mass. To 100 mL of the diluted solution, 200 mL of isopropanol was added to gel the CNF 1 and filtered off with filter paper. The filtered gel was dried at 60 ° C. for 20 minutes to obtain high solids CNF. The obtained concentrate was treated and milled for 1 minute with a mixer (BM-RE08-HA, manufactured by ZOJI).

Example 9:
CNF1 was diluted to 0.4% by mass. To 100 mL of the diluted solution, 200 mL of isopropanol was added to gel the CNF 1 and filtered off with filter paper. The filtered gel was dried at 60 ° C. for 30 minutes to obtain CNF1 of high solid content. The obtained concentrate was treated and milled for 1 minute with a mixer (BM-RE08-HA, manufactured by ZOJI).

Example 10:
CNF1 was diluted to 0.4% by mass. To 100 mL of the diluted solution, 200 mL of isopropanol was added to gel the CNF, and filtered off with filter paper. The filtered gel was dried at 60 ° C. for 60 minutes to obtain high solids CNF1. The obtained concentrate was treated and milled for 1 minute with a mixer (BM-RE08-HA, manufactured by ZOJI).

Example 11:
CNF1 was diluted to 0.4% by mass. To 100 mL of the diluted solution, 5000 mL of isopropanol was added to gelate CNF 1 and filtered off with filter paper. The filtered gel was dried at 60 ° C. for 60 minutes to obtain high solids CNF. The obtained concentrate was treated and milled for 1 minute with a mixer (BM-RE08-HA, manufactured by ZOJI).

Comparative Example 1:
CNF1 was diluted to 0.4% by mass. After adding 80 mL of isopropanol to 100 mL of the diluted solution, the mixture was dried at 60 ° C. for 60 minutes to obtain 22.2% of CNF1. The obtained concentrate was treated and milled for 1 minute with a mixer (BM-RE08-HA, manufactured by ZOJI).

Comparative example 2:
CNF1 was diluted to 0.4% by mass. To 100 mL of the diluted solution, 20000 mL of isopropanol was added, CNF1 was gelled, filtered through filter paper, and squeezed with filter paper for 2 minutes to obtain a concentrate. The obtained concentrate was treated and milled for 1 minute with a mixer (BM-RE08-HA, manufactured by ZOJI).

The results obtained by performing the following measurements and evaluations on the concentrates prepared in the examples and the comparative examples are shown in the following table.

(Measurement of haze value)
The concentrate prepared in each Example and each Comparative Example is added to 100 mL of ion-exchanged water, and stirred at 1500 rpm for 5 minutes with Disparser (stirred TK Robotics, manufactured by Tokushu Kika Kogyo), 0.4 mass% An aqueous solution (also called redispersion) was prepared.
The haze of the 0.4% by mass aqueous solution was measured using a haze meter ("HM-150" manufactured by Murakami Color Research Laboratory, Inc.) according to JIS Standard K7136.

(Dispersibility evaluation)
The concentrate prepared in each Example and each Comparative Example was added to 100 mL of ion-exchanged water, and stirred at 1500 rpm for 5 minutes to prepare a 0.4% by mass aqueous solution (also referred to as a redispersion liquid).
After adding 1.0 mass% of hydrophobized titanium oxide (STV-455, manufactured by Titanium Kogyo Co., Ltd.) to 100 mL of the 0.4 mass% aqueous solution, stirring was performed for 5 minutes at a rotation number of 4,000 rpm using a homomixer. The mixture was allowed to stand for 30 minutes to observe whether the hydrophobized titanium oxide separated from the aqueous layer.
◎: The hydrophobized titanium oxide is not separated at all, maintaining uniformity.
:: A slightly separated hydrophobized titanium oxide is present, but the uniformity is maintained as a whole.
×: hydrophobized titanium oxide particles are present in the precipitate or water surface and separated from the water layer.

Claims (5)

A fine fibrous cellulose-containing material comprising fine fibrous cellulose, an alcohol and water, wherein the content of the fine fibrous cellulose is 5% by mass or more, and the content C1 of the alcohol and the content C2 of the water A fine fibrous cellulose-containing material, wherein the mass ratio C1 / C2 thereof is 1 or more and 100 or less, and the fine fibrous cellulose has a phosphoric acid group. The fine fibrous cellulose-containing material according to claim 1, which is in the form of powdery particles. The fine fibrous cellulose containing material of Claim 1 or 2 whose said mass ratio C1 / C2 is 1 or more and 20 or less. The fine fibrous cellulose-containing substance according to any one of claims 1 to 3, wherein the content of the fine fibrous cellulose is 5% by mass or more and 98% by mass or less. The fine fibrous cellulose containing material as described in any one of Claims 1-4 whose quantity of the phosphoric acid group in the said fine fibrous cellulose is 0.5 mmol / g or more.

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