JP2024013544A - Deodorant for liquid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a deodorant for liquids that can be applied to liquids containing ammonia, for example, a hair color agent, a detergent, a medicine for insect bite relief, or a cosmetic preparation, and demonstrates superior deodorant effect while suppressing ammonia volatilization.

SOLUTION: A deodorant for liquids includes cellulose nanofibers, preferably cellulose nanofibers with a carboxyalkyl group or cellulose nanofibers with a carboxy group.

SELECTED DRAWING: None

COPYRIGHT: (C)2024,JPO&INPIT

Description

The present invention relates to a liquid deodorizer that has an excellent deodorizing effect against ammonia and the like.

As deodorants against ammonia, various forms of deodorants using acidic substances such as carboxylic acids or their salts, such as fibers, filters, sprays, sheets, gels, and aqueous solutions, have been studied.

For example, a deodorant composed of an alkali metal salt of carboxyalkylcellulose in the form of an aqueous solution, an aqueous gel, or a film has been proposed (Patent Document 1).

JP2007-268084A

However, in the method of Patent Document 1, the deodorizing effect was insufficient for an aqueous solution containing ammonia.

An object of the present invention is to provide a liquid deodorant that can be applied to liquids containing ammonia, suppresses volatilization of ammonia, and has an excellent deodorizing effect.

As a result of intensive studies to achieve this object, the present inventors found that it is effective to incorporate anion-modified cellulose nanofibers into deodorants, and completed the present invention.

The present invention provides the following.
(1) A liquid deodorant containing cellulose nanofibers.
(2) The liquid deodorant according to (1), wherein the cellulose nanofibers are anion-modified cellulose nanofibers.
(3) The liquid deodorant according to (1) or (2), wherein the anion-modified cellulose nanofiber is a cellulose nanofiber having a carboxyalkyl group or a cellulose nanofiber having a carboxy group.
(4) The liquid deodorant according to (3), which is carboxymethylated cellulose nanofibers in which the degree of carboxymethyl substitution of the anion-modified cellulose nanofibers is within the range of 0.01 to 0.50.
(5) The liquid deodorant according to any one of (1) to (4), further comprising carboxymethylated cellulose.
(6) A hair coloring agent, detergent, insect sting liquid, or cosmetic product containing the liquid deodorant according to any one of (1) to (4).
(7) Hair coloring agents, detergents, insect sting liquids, or cosmetics containing the liquid deodorant described in (5).

The deodorizing agent of the present invention has an excellent deodorizing effect on ammonia when applied to a liquid containing ammonia. It also has a sustained release effect in dispersing ammonia in the liquid into the atmosphere.

Hereinafter, the liquid deodorant of the present invention will be explained. In the present invention, "~" includes extreme values. That is, "X~Y" includes the values X and Y at both ends.

The present invention is a liquid deodorant containing cellulose nanofibers.

(cellulose nanofiber)
In the present invention, cellulose nanofibers (CNF) are obtained by pulverizing pulp, which is a cellulose raw material, to a fiber width on the nanometer level. The fiber width (average fiber diameter) of CNF is usually about 3 nm to several hundred nm, for example about 3 to 500 nm. In the present invention, the average fiber diameter of CNF is preferably about 3 to 100 nm, more preferably about 3 to 20 nm. The aspect ratio is 30 or more, preferably 50 or more, and more preferably 100 or more. The upper limit of the aspect ratio is not limited, but is about 500 or less.

The average fiber diameter and average fiber length of CNFs were randomly selected using atomic force microscopy (AFM) if the diameter was less than 20 nm, and field emission scanning electron microscopy (FE-SEM) if the diameter was 20 nm or more. It can be measured by analyzing 200 fibers and calculating the average. Additionally, the aspect ratio can be calculated using the following formula:
Aspect ratio = average fiber length/average fiber diameter.

CNF can be obtained by applying mechanical force to a cellulose raw material such as pulp, which will be described later, to make it fine (fibrillated). As the cellulose raw material, unmodified cellulose, pulp for paper making, etc., which will be described later, may be used, or chemically modified cellulose, which is obtained by further chemically modifying pulp for paper making, etc. may be used. Examples of chemically modified cellulose include, but are not limited to, anion-modified cellulose in which an anionic group is introduced into the cellulose chain, and it is preferable to use anion-modified cellulose. Anion-modified CNF can be obtained by defibrating anion-modified cellulose to have an average fiber diameter of less than 1 μm. The defibration method is not particularly limited, and any known defibration device such as a high-speed rotation type, colloid mill type, high pressure type, roll mill type, or ultrasonic type may be used. Among these, it is preferable to use a wet high pressure or ultra high pressure homogenizer. Examples of anion-modified CNF include carboxyalkylated CNF in which a carboxyalkyl group having an anion-modifying group capable of forming a salt with ammonium ion (NH ₄ ⁺ ) dissolved in water is introduced, and carboxylated CNF in which a carboxyl group is introduced. Examples include CNF, phosphoric acid esterified CNF into which a phosphoric acid group has been introduced, and sulfate esterified CNF into which a sulfuric acid group has been introduced. Among these, CNF having a carboxyalkyl group (carboxyalkylated CNF) or CNF having a carboxyl group (carboxylated CNF) is preferred.

(cellulose raw material)
Cellulose, which is a raw material for CNF, is known to originate from plants, animals (e.g., ascidians), algae, microorganisms (e.g., acetic acid bacteria), microbial products, etc. Either can be used. Plant-derived materials include, for example, wood, bamboo, hemp, jute, kenaf, agricultural residue, cloth, pulp (softwood unbleached kraft pulp (NUKP), softwood bleached kraft pulp (NBKP), hardwood unbleached kraft pulp ( LUKP), hardwood bleached kraft pulp (LBKP), softwood unbleached sulfite pulp (NUSP), softwood bleached sulfite pulp (NBSP), thermomechanical pulp (TMP), recycled pulp, waste paper, etc.). In the present invention, cellulose fibers derived from plants or microorganisms are preferred, and cellulose fibers derived from plants are more preferred. The cellulosic raw material may be chemically modified as described below. Chemically modified CNF such as CNF or anion-modified CNF can be obtained by refining the fiber width of the above-mentioned cellulose raw material or cellulose raw material that has undergone chemical modification such as anion modification (chemically modified cellulose) to the nanometer level. can.

(CNF having a carboxyalkyl group (carboxyaalkylated CNF))
An example of anion-modified CNF is carboxyalkylated CNF having a carboxyalkyl group. In this specification, the carboxyalkyl group refers to -RCOOH (acid type) and -RCOOM (metal salt type). Here, R is an alkylene group such as a methylene group or an ethylene group, and M is a metal ion. Among these, CM-modified CNF having a CM group in which R is a methylene group is most preferred. Carboxyalkylated CNF is obtained by obtaining carboxyalkylated cellulose using a known method of treating a cellulose raw material with a mercerizing agent and then treating it with a carboxyalkylating agent to introduce a carboxyalkyl group, and then defibrating it. Obtainable.

The degree of carboxyalkyl substitution per anhydroglucose unit of the carboxyalkylated CNF is preferably 0.50 or less. Further, the lower limit of the degree of carboxyalkyl substitution is preferably 0.01 or more. In consideration of operability, the degree of substitution is preferably 0.02 or more and 0.40 or less, more preferably 0.02 or more and 0.35 or less, and preferably 0.10 or more and 0.35 or less. It is more preferably 0.15 or more and 0.35 or less, even more preferably 0.15 or more and 0.30 or less. Note that anhydroglucose units mean individual anhydroglucoses (glucose residues) that constitute cellulose, and carboxyalkyl substitution degree refers to carboxyalkyl substitution among hydroxyl groups (-OH) in glucose residues that constitute cellulose. The proportion (number of carboxyalkyl groups per glucose residue) of those substituted with groups (-ORCOOH or -ORCOOM) is shown. The degree of carboxyalkyl substitution can be adjusted by controlling reaction conditions such as the amount of mercerizing agent and reaction time. The degree of CM substitution per glucose unit can be measured by the following method:
Accurately weigh approximately 2.0 g of CM-modified CNF (absolutely dry) and place it in a 300 mL Erlenmeyer flask with a stopper. Add 100 mL of a solution prepared by adding 100 mL of special grade concentrated nitric acid to 900 mL of methanol, and shake for 3 hours to convert salt-type CM-ized CNF to hydrogen-type CM-ized CNF. Accurately weigh 1.5 g to 2.0 g of hydrogen-type CM-formed CNF (absolutely dry) and place it in a 300 mL Erlenmeyer flask with a stopper. The hydrogenated CM-ized CNF is moistened with 15 mL of 80% by mass methanol, 100 mL of 0.1N NaOH is added, and the mixture is shaken at room temperature for 3 hours. Excess NaOH is back-titrated with 0.1N H ₂ SO ₄ using phenolphthalein as indicator. The degree of CM substitution (DS) is calculated by the following formula:
A=[(100×F'-(0.1N H ₂ SO ₄ )(mL)×F)×0.1]/(absolute dry mass (g) of hydrogen-type CM-modified CNF)
DS=0.162×A/(1-0.058×A)
A: Amount of 1N NaOH required to neutralize 1g of hydrogen-type CM-modified CNF (mL)
F: Factor of 0.1N H ₂ SO ₄ F': Factor of 0.1N NaOH

The degree of substitution of carboxyalkyl groups other than CM groups can also be measured by the same method as above.

In this specification, "CM-modified cellulose" which is a type of anion-modified cellulose used for the preparation of CM-modified cellulose and "CM-modified CNF" obtained by defibrating CM-modified cellulose are It also refers to something that retains at least part of its fibrous shape. Therefore, "CM-modified cellulose" and "CM-modified CNF" are distinguished from carboxymethyl cellulose (hereinafter referred to as "CMC"), which is a type of water-soluble polymer. When an aqueous dispersion of "CM cellulose" is observed under an electron microscope, fibrous substances can be observed. On the other hand, when observing an aqueous dispersion of CMC, which is a type of water-soluble polymer, no fibrous substance is observed. In addition, when measuring "CM-modified cellulose" and "CM-modified CNF" by X-ray diffraction, a peak of cellulose type I crystals can be observed, but cellulose type I crystals are not observed in CMC, a water-soluble polymer. do not have.

(CNF having a carboxyl group (carboxylated CNF))
An example of anionic CNF is carboxylated CNF having a carboxyl group. In this specification, the carboxyl group refers to -COOH (acid type) and -COOM (metal salt type) (wherein M is a metal ion), or -COO ^{2 -} . Carboxylated CNF can be obtained by obtaining carboxylated cellulose using a known method of oxidizing the hydroxyl group of the pyranose ring of cellulose into a carboxyl group, and then defibrating it. As a method for oxidizing cellulose, for example, oxidation is performed in the presence of an N-oxyl compound such as 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO) and bromide and/or iodide. Examples include a method of oxidizing cellulose in water using an oxidizing agent, and a method of oxidizing cellulose by bringing it into contact with a cellulose raw material using a gas containing ozone as an oxidizing agent.

The amount of carboxyl groups in carboxylated CNF is preferably 0.4 to 3.0 mmol/g, more preferably 0.6 to 2.0 mmol/g, and more preferably 1.0 to 2.0 mmol/g, based on the absolute dry mass of carboxylated CNF. 2.0 mmol/g is more preferable, and 1.1 to 2.0 mmol/g is even more preferable. The amount of carboxyl groups in carboxylated CNF can be adjusted by controlling reaction conditions such as the amount of oxidizing agent added and reaction time. The amount of carboxyl groups can be measured by the following method:
60 ml of 0.5% by mass slurry (aqueous dispersion) of carboxylated CNF was prepared, and after adding 0.1M hydrochloric acid aqueous solution to adjust the pH to 2.5, 0.05N sodium hydroxide aqueous solution was added dropwise to adjust the pH to 11. The electrical conductivity is measured until the electrical conductivity changes, and the amount of sodium hydroxide (a) consumed during the neutralization stage of the weak acid, where the electrical conductivity changes slowly, is calculated using the following formula:
Amount of carboxy groups [mmol/g carboxylated CNF] = a [ml] x 0.05/mass of carboxylated CNF [g].

(Phosphate esterified CNF)
An example of anionic CNF is phosphoric acid esterified CNF. Phosphoric acid esterified CNF is produced by mixing phosphoric acid compound powder or aqueous solution with the cellulose raw material mentioned above, or by adding an aqueous solution of phosphoric acid compound to a slurry of cellulose raw material. It can be obtained by introducing an acidic group into cellulose to obtain phosphoric acid esterified cellulose, which is then defibrated. Examples of phosphoric acid compounds include phosphoric acid, polyphosphoric acid, phosphorous acid, hypophosphorous acid, phosphonic acid, polyphosphonic acid, and esters or salts thereof. Specifically, for example, but not limited to, phosphoric acid, sodium dihydrogen phosphate, disodium hydrogen phosphate, trisodium phosphate, sodium phosphite, potassium phosphite, sodium hypophosphite, the following: Potassium phosphite, sodium pyrophosphate, sodium metaphosphate, potassium dihydrogen phosphate, dipotassium hydrogen phosphate, tripotassium phosphate, potassium pyrophosphate, potassium metaphosphate, ammonium dihydrogen phosphate, diammonium hydrogen phosphate, Examples include triammonium phosphate, ammonium pyrophosphate, ammonium metaphosphate, and the like. A phosphoric acid group derived from a phosphoric acid compound can be introduced into cellulose by using one type or a combination of two or more of these. In this specification, phosphoric acid groups derived from phosphoric acid compounds include phosphoric acid groups, phosphorous acid groups, hypophosphorous acid groups, pyrophosphoric acid groups, metaphosphoric acid groups, polyphosphoric acid groups, phosphonic acid groups, and polyphosphonic acid groups. Phosphate-esterified cellulose and phosphate-esterified CNF include those in which one or more of these phosphate groups are introduced into the molecular chain of cellulose. When reacting a cellulose raw material with a phosphoric acid compound, it is preferable to use the phosphoric acid compound as an aqueous solution because the reaction can proceed uniformly and the efficiency of introducing the above groups is increased. The pH is preferably 3 to 7. Further, a nitrogen-containing compound such as urea may be added.

The degree of substitution of a phosphate group per glucose unit in the phosphoric acid esterified CNF (hereinafter simply referred to as "degree of phosphate group substitution") is preferably 0.001 or more and less than 0.40. The degree of phosphate group substitution per glucose unit can be measured by the following method:
A slurry of phosphoric acid esterified CNF having a solid content of 0.2% by mass is prepared. To the slurry, 1/10 of the volume of strongly acidic ion exchange resin (Amber Jet 1024; manufactured by Organo, preconditioned) was added, and after shaking for 1 hour, the resin was poured onto a mesh with an opening of 90 μm. By separating the CNF and the slurry, hydrogen-type phosphated CNF is obtained. Next, 50 μL of a 0.1 N aqueous sodium hydroxide solution is added to the slurry treated with the ion exchange resin once every 30 seconds, and the change in the electrical conductivity value of the slurry is measured. Among the measurement results, by dividing the amount of alkali (mmol) required in the region where the electrical conductivity suddenly decreases by the solid content (g) in the titration target slurry, the amount per gram of hydrogen-type phosphated CNF can be calculated. Calculate the amount of phosphate groups (mmol/g). Furthermore, the degree of phosphoryl substitution (DS) per glucose unit of phosphorylated CNF is calculated by the following formula:
DS=0.162×A/(1-0.079×A)
A: Amount of phosphate groups per 1 g of hydrogen-type phosphate-esterified CNF (mmol/g).

(Sulfate esterified CNF)
An example of anionic CNF is sulfate-esterified CNF. Sulfate-esterified CNF can be obtained by reacting the above-mentioned cellulose raw material with a sulfate-based compound to introduce a sulfate-based group derived from the sulfate-based compound into cellulose to obtain sulfate-esterified cellulose, and then fibrillating this. Can be done. Examples of sulfuric acid compounds include sulfuric acid, sulfamic acid, chlorosulfonic acid, sulfur trioxide, and esters or salts thereof. Among these, it is preferable to use sulfamic acid because the solubility of cellulose is low and the acidity is low.

For example, when sulfamic acid is used as the sulfuric acid compound, the amount of sulfamic acid used can be adjusted as appropriate, taking into consideration the amount of anionic groups introduced into the cellulose chain. For example, it can be used preferably in an amount of 0.01 to 50 mol, more preferably 0.1 to 3.0 mol, per mol of glucose unit in the cellulose molecule.

The amount of sulfate groups per glucose unit (hereinafter simply referred to as "sulfate group amount") in the sulfate-esterified CNF is preferably 0.1 to 3.0 mmol/g. The amount of sulfate groups per glucose unit can be measured by the following method:
The aqueous dispersion of sulfated CNF is subjected to solvent replacement with ethanol and t-butanol in this order, and then freeze-dried. Add 15 ml of ethanol and 5 ml of water to 200 mg of the obtained sample, and stir for 30 minutes. Then, 10 ml of 0.5N aqueous sodium hydroxide solution was added, stirred at 70°C for 30 minutes, and further stirred at 30°C for 24 hours. Next, add phenolphthalein as an indicator, titrate with hydrochloric acid, and calculate using the following formula:
Sulfate group amount [mmol/g sample] = (5-(0.1 x hydrochloric acid titration [ml] x 2))/0.2.

(Powder containing CNF)
In the production method of the present invention, a CNF aqueous suspension is produced using the above-mentioned CNF-containing powder. In the present invention, "powder" refers to a dry solid obtained by drying until the moisture content becomes 0 to 15% by mass. Preferably, the water content is 0 to 10% by mass. Normally, it tends to be difficult to redisperse CNF when dried to such a moisture content, but the method of the present invention improves redispersibility and makes it possible to use a stirrer with a low rotation speed. The amount of gel particles remaining can be reduced even if the gel particles remain. The moisture content in the powder can be calculated using the mass after drying the powder at 105° C. for 3 hours or more (absolutely dry mass) and the mass before drying.

The shape of the dry solid "powder" is preferably fine and homogeneous, considering ease of suspension, but it is preferable that some of the powder aggregates to form lumps. It may be in any shape or in granule form.

A powder containing CNF can be produced, for example, but not limited to, by drying the above-mentioned dispersion containing CNF. The dispersion medium in the dispersion to be dried is not particularly limited, but is preferably water, a hydrophilic organic solvent, a hydrophobic organic solvent, or a mixed solvent thereof; More preferred. The device used for drying is not particularly limited. For example, a vacuum drum dryer, a normal pressure drum dryer, a spray dryer, a hot air dryer, a warm air dryer, etc. can be used.

The "CNF-containing powder" to be suspended in the present invention may contain other components in addition to CNF. For example, water-soluble polymer powder may be included to improve redispersibility. Examples of water-soluble polymers include cellulose derivatives (carboxymethylcellulose (CMC), methylcellulose, hydroxypropylcellulose, ethylcellulose), xanthan gum, xyloglucan, dextrin, dextran, carrageenan, locust bean gum, alginic acid, alginate, pullulan, and starch. , Katakuri flour, arrowroot flour, modified starch (cationized starch, phosphorylated starch, phosphoric acid cross-linked starch, phosphoric acid monoesterified phosphoric acid cross-linked starch, hydroxypropyl starch, hydroxypropylated phosphate cross-linked starch, acetylated adipic acid cross-linked starch) , acetylated phosphate cross-linked starch, acetylated oxidized starch, sodium starch octenylsuccinate, starch acetate, oxidized starch), corn starch, gum arabic, gellan gum, polydextrose, pectin, chitin, water-soluble chitin, chitosan, casein, albumin, soybean Protein solution, peptone, polyvinyl alcohol, polyacrylamide, polyacrylate, polyvinylpyrrolidone, polyvinyl acetate, polyamino acid, polylactic acid, polymalic acid, polyglycerin, latex, rosin-based sizing agent, petroleum resin-based sizing agent, urea Resin, melamine resin, epoxy resin, polyamide resin, polyamide/polyamine resin, polyethyleneimine, polyamine, vegetable gum, polyethylene oxide, hydrophilic crosslinked polymer, starch polyacrylic acid copolymer, tamarind gum, guar gum, colloidal silica, or these Mixtures of one or more of these may be mentioned. Among these, cellulose derivatives are preferred from the viewpoint of compatibility with CNF, and CMC and its salts are particularly preferred. It is thought that water-soluble polymers such as CMC and its salts penetrate between the CNF fibers and increase the distance between the fibers, thereby improving redispersibility.

When using CMC as a water-soluble polymer, the carboxymethyl group substitution degree of CMC is preferably in the range of 0.55 to 1.60, more preferably 0.55 to 1.10, and more preferably 0.65 to 1.10. 1.10 is more preferred. Note that since CMC having such a degree of carboxymethyl group substitution dissolves in water, it does not maintain the shape of cellulose-derived fibers in water. As mentioned above, "CMC" as a water-soluble polymer is distinguished from "carboxymethylated cellulose" which maintains a fibrous shape in water. Further, "carboxymethylated CNF" obtained by defibrating "carboxymethylated cellulose" to have an average fiber diameter of less than 1 μm is also distinguished from "CMC".

When blending a water-soluble polymer into a powder containing CNF, the amount of water-soluble polymer blended is preferably 5 to 300 mass%, and 20 to 300 mass% based on CNF (bone dry solid content). It is more preferably 25 to 200% by mass, even more preferably 25 to 60% by mass.

In addition, the powder containing CNF may contain components other than CNF and water-soluble polymers, such as trace amounts of metal components, as long as the effects of the present invention are not impaired.

The deodorant of the present invention may optionally contain a masking agent (fragrance, etc.), a photocatalytic compound (for example, titanium oxide, zinc oxide, ferric oxide, etc.), an antibacterial agent, a fungicide, a preservative, and a pH adjustment agent. Agents, surfactants, colorants, adsorbent deodorizers (activated carbon, etc.), etc. may be used in combination.

The deodorant of the present invention can be applied to hair coloring agents, detergents, insect sting liquids, cosmetics, etc. containing ammonia.

EXAMPLES Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited thereto.

(Method for measuring degree of carboxymethyl substitution)
1) Accurately weigh about 2.0 g of carboxymethylated cellulose fiber (absolutely dry) and place it in a 300 mL Erlenmeyer flask with a stopper.
2) Add 100 mL of a solution obtained by adding 100 mL of special grade concentrated nitric acid to 1000 mL of methanol nitric acid, and shake for 3 hours to convert carboxymethylcellulose salt (CM-modified cellulose) into hydrogen-type CM-modified cellulose.
3) Accurately weigh 1.5 to 2.0 g of hydrogenated CM cellulose (absolutely dry) and place it in a 300 mL Erlenmeyer flask with a stopper.
4) Wet the hydrogenated CM cellulose with 15 mL of 80% methanol, add 100 mL of 0.1N NaOH, and shake at room temperature for 3 hours.
5) Back titrate excess NaOH with 0.1N H ₂ SO ₄ using phenolphthalein as indicator.
6) Calculate the degree of carboxymethyl substitution (DS) by the following formula:
A = [(100 x F' - (0.1N H ₂ SO ₄ ) (mL) x F) x 0.1] / (absolute dry mass (g) of hydrogenated CM cellulose)
DS=0.162×A/(1-0.058×A)
A: Amount of 1N NaOH required to neutralize 1g of hydrogenated CM cellulose (mL)
F': 0.1N H ₂ SO ₄ factor F: 0.1N NaOH factor (Method for measuring average fiber diameter and aspect ratio)
The average fiber diameter and average fiber length of CNF were analyzed using an atomic force microscope (AFM) for 200 randomly selected fibers. The aspect ratio was calculated using the following formula.
Aspect ratio = average fiber length / average fiber diameter

[Example 1]
(Production of carboxymethylated cellulose nanofibers)
1089 parts of isopropanol (IPA) and 31 parts of sodium hydroxide dissolved in 121 parts of water were added to a 5L twin-screw kneader whose rotational speed was adjusted to 100 rpm, and hardwood pulp (manufactured by Nippon Paper Industries, Ltd.) was added. LBKP) was charged at a dry weight of 200 parts when dried at 100° C. for 60 minutes. The mixture was stirred and mixed at 30° C. for 60 minutes to prepare mercerized cellulose. Further, while stirring, 117 parts of sodium monochloroacetate was added, and after stirring at 30°C for 30 minutes, the temperature was raised to 70°C over 30 minutes, and a carboxymethylation reaction was carried out at 70°C for 60 minutes. The proportion of water in the reaction medium during the mercerization reaction and the carboxymethylation reaction is 10% by mass. After the reaction is completed, it is neutralized, washed with 65% aqueous methanol, dehydrated, dried, and pulverized to obtain sodium salt of carboxymethylated cellulose with a degree of carboxymethyl substitution of 0.27 and a crystallinity of cellulose I type 64%. I got it. The method for measuring the degree of carboxymethyl substitution and the crystallinity of cellulose I type is as described above.
The obtained sodium salt of carboxymethylated cellulose was dispersed in water to form a 1% (w/v) aqueous dispersion. This was treated three times with a 150 MPa high-pressure homogenizer to obtain a dispersion of carboxymethylated cellulose nanofibers. The obtained carboxymethylated cellulose nanofibers had an average fiber diameter of 3.2 nm and an aspect ratio of 40.

(Manufacture of CNF powder)
The obtained carboxymethylated cellulose nanofibers were made into a dispersion with solid content of 0.7% by mass in water, and carboxymethylcellulose (manufactured by Nippon Paper Industries Co., Ltd., trade name: F350HC-4, viscosity (1% by mass, 25°C, 60 rpm) about 3000 mPa・s, carboxymethyl substitution degree of about 0.90) to 40% by mass of carboxymethylated cellulose nanofibers (i.e., when the solid content of carboxymethylated cellulose nanofibers is 100 parts by mass) The solid content of carboxymethylcellulose was 40 parts by mass) and stirred for 60 minutes using a TK homomixer (12,000 rpm).
After adding 0.5% by mass of an aqueous sodium hydroxide solution to this dispersion and adjusting the pH to 9, the dispersion was applied onto the drum surface of a drum dryer D0405 (manufactured by Katsuragi Kogyo Co., Ltd.) and dried at 140° C. for 1 minute. The obtained dried product was scraped off, and then pulverized using an impact mill at a rate of 10 kg per hour to obtain a dry pulverized product with a moisture content of 5% by mass. The obtained pulverized product was classified using 30 mesh to obtain a powder (CNF powder) containing carboxymethylated cellulose nanofibers and carboxymethyl cellulose.

(Preparation of mixed aqueous solution containing ammonia)
CNF powder was added to a 0.25% aqueous solution of ammonia to a concentration of 1%, and mixed and stirred for 5 minutes in a sealed container to prepare a mixed aqueous solution. Thereafter, the mixed aqueous solution was transferred to an open container, and the amount of ammonia volatilization (ammonia concentration in the gas layer at the top of the container) and the pH of the mixed aqueous solution were measured over time. To measure the amount of ammonia volatilization, a detector tube type gas meter (GV100S manufactured by Gastech) was used to measure the ammonia concentration at a height of 15 cm from the liquid level in the open container. The results are shown in Table 1.

[Comparative example 1]
A mixed aqueous solution was prepared in the same manner as in Example 1, except that no CNF powder was added, and the ammonia concentration and pH of the mixed aqueous solution were measured over time. The results are shown in Table 1.

[Comparative example 2]
Example 1 except that methyl cellulose (trade name: Methyl Cellulose (7000-10000 mPa・s 2% in Water at 20°C), manufactured by Tokyo Kasei Kogyo) was added to a concentration of 1.3% instead of CNF powder. A mixed aqueous solution was prepared in the same manner, and the ammonia concentration and pH of the mixed aqueous solution were measured over time. The results are shown in Table 1.

As shown in Table 1, by adding carboxymethylated cellulose nanofibers to the ammonia aqueous solution, the amount of ammonia volatilization was suppressed and the decrease in pH was also suppressed. Furthermore, the amount of ammonia volatilized after 24 hours was greater than that in Comparative Examples 1 and 2, and a sustained release effect was also observed.

Claims (7)

A liquid deodorant containing cellulose nanofiber. The liquid deodorant according to claim 1, wherein the cellulose nanofibers are anion-modified cellulose nanofibers. 3. The liquid deodorant according to claim 1, wherein the anion-modified cellulose nanofiber is a cellulose nanofiber having a carboxyalkyl group or a cellulose nanofiber having a carboxy group. The liquid deodorant according to claim 3, which is carboxymethylated cellulose nanofibers in which the degree of carboxymethyl substitution of the anion-modified cellulose nanofibers is within the range of 0.01 to 0.50. The liquid deodorant according to any one of claims 1 to 4, further comprising carboxymethylated cellulose. A hair coloring agent, detergent, insect bite liquid, or cosmetic product comprising the liquid deodorant according to any one of claims 1 to 4. A hair coloring agent, detergent, insect sting liquid, or cosmetic product comprising the liquid deodorant according to claim 5.