WO2022097544A1

WO2022097544A1 - Cleansing preparation

Info

Publication number: WO2022097544A1
Application number: PCT/JP2021/039618
Authority: WO
Inventors: 苑加宮田; 碧坂巻
Original assignee: 日本製紙株式会社
Priority date: 2020-11-05
Filing date: 2021-10-27
Publication date: 2022-05-12
Also published as: JPWO2022097544A1

Abstract

A cleansing preparation containing cellulose nanofibers is provided.

Description

Cleaning fee

The present invention relates to a cleaning agent containing cellulose nanofibers.

Finely divided cellulose fibers are added to cosmetics. For example, in Patent Document 1, a cellulose fiber having an average fiber diameter and a ratio of an average fiber length to an average fiber diameter in a specific range is described. It is described to be used as an additive for cosmetics.

Further, Patent Document 2 describes a cleansing cosmetic containing a modified cellulose fiber as a thickener.

International Publication No. 2014/088034 International Publication No. 2018/186261

However, in Patent Document 2, liquid cleansing cosmetics contain cellulose fibers having a specific substituent to impart appropriate viscosity, and when they are picked up, they do not easily drip from between fingers and spread. The purpose is to provide a cleansing cosmetic having excellent ductility and excellent ejection property when filled in a pump-type container, and no study has been made from the viewpoint of improving detergency.

Therefore, an object of the present invention is to provide a cleaning agent having excellent safety and a high cleaning effect.

As a result of diligent studies to achieve such an object, the present inventor has found that it is effective to blend cellulose nanofibers (CNF), and has completed the present invention.

The present invention provides:
(1) A cleaning agent containing cellulose nanofibers.
(2) The cleaning agent according to (1), which contains the cellulose nanofibers in an amount of 0.05% by mass or more and 5% by mass or less.
(3) The cleaning agent according to (1) or (2), wherein the cellulose nanofibers are carboxymethylated cellulose nanofibers.
(4) The carboxymethylated cellulose nanofiber has a degree of carboxymethyl substitution per anhydrous glucose unit of cellulose of 0.01 to 0.50, and a degree of crystallinity of cellulose type I is 40% or more (3). ) The listed cleaning fee.
(5) The cleaning agent according to any one of (1) to (4), which further contains carboxymethyl cellulose.
(6) The cleaning agent according to any one of (1) to (5), wherein the cleaning agent is a washing pigment, a cleansing cosmetic, soap, shampoo, hand soap or body soap.

According to the present invention, it is possible to provide a cleaning agent having excellent safety and a high cleaning effect.

The observation result using the microscope of the bioskin before the application of pseudo-sebum is shown. The observation results using a microscope of Bioskin after application of pseudo-sebum are shown. The observation result using the microscope of the bioskin after washing with the washing agent 1 of Example 1 is shown. The observation result using the microscope of the bioskin after washing with the washing agent 2 of the comparative example 1 is shown.

Hereinafter, the present invention will be described in detail. In the present invention, "-" includes a fractional value. That is, "X to Y" includes the values X and Y at both ends thereof.

The cleaning agent of the present invention contains cellulose nanofibers as an essential component.

(Cellulose nanofiber)
In the present invention, the cellulose nanofiber (CNF) is a fine fiber in which pulp or the like, which is a raw material for cellulose, is miniaturized to the nanometer level, and the fiber diameter is about 3 to 500 nm. The average fiber diameter and average fiber length of cellulose nanofibers shall be the average of the fiber diameter and fiber length obtained from the results of observing each fiber using an atomic force microscope (AFM) or a transmission electron microscope (TEM). Can be obtained by. Cellulose nanofibers can be obtained by applying mechanical force to the pulp to make it finer, or carboxylated cellulose (also called oxidized cellulose), carboxymethylated cellulose, or cellulose into which a phosphate ester group has been introduced. It can be obtained by chemically modifying cationized cellulose or the like and by defibrating the modified cellulose. In the present invention, it is preferable to use the chemically modified CNF obtained by defibrating the chemically modified cellulose. As the type of chemical modification, carboxyalkylation, carboxylation, and esterification are preferable, and among the carboxyalkylations, those carboxymethylated are more preferable. The average fiber length and average fiber diameter of the fine fibers can be adjusted by a chemical modification treatment or a defibration treatment.

The average aspect ratio of the cellulose nanofibers used in the present invention is not particularly limited, but is usually 25 or more. The upper limit is not particularly limited, but is usually 1000 or less. When the aspect ratio is 25 or more, the fibrous shape gives an effect of improving thixotropic property. The average fiber diameter and average fiber length are 200 randomly selected using an atomic force microscope (AFM) when the diameter is 20 nm or less and a field emission scanning electron microscope (FE-SEM) when the diameter is 20 nm or more. It can be measured by analyzing the fibers of the above and calculating the average. The average aspect ratio can be calculated by the following formula:
Aspect ratio = average fiber length / average fiber diameter

When the carboxymethylated cellulose nanofiber described later is used as the cellulose nanofiber, the average fiber diameter is 3 nm to 500 nm, preferably 3 nm to 150 nm, more preferably 3 nm to 20 nm, still more preferably 5 nm to 19 nm, and further. It is preferably 5 nm to 15 nm. The aspect ratio is not particularly limited, but is preferably 350 or less, more preferably 300 or less, further preferably 200 or less, further preferably 120 or less, and even more preferably 100 or less. It is more preferably 80 or less, and even more preferably 80 or less. The lower limit of the aspect ratio is not particularly limited, but is preferably 25 or more, and more preferably 30 or more. The aspect ratio of the carboxymethylated cellulose nanofibers can be controlled by the mixing ratio of the solvent and water at the time of carboxymethylation, the amount of chemicals added, and the degree of carboxymethylation. Further, the carboxymethylated cellulose nanofiber having an aspect ratio in the above range can be produced, for example, by a production method described later.

(Cellulose raw material)
Cellulose raw materials include plants (eg, wood, bamboo, hemp, jute, kenaf, farmland waste, cloth, pulp (conifer unbleached kraft pulp (NUKP), conifer bleached kraft pulp (NBKP), broadleaf unbleached kraft pulp (NBKP)). LUKP), broadleaf bleached kraft pulp (LBKP), conifer unbleached sulphite pulp (NUSP), conifer bleached sulphite pulp (NBSP) thermomechanical pulp (TMP), recycled pulp, used paper, etc.), animals (eg, squirrels), Those originating from algae, microorganisms (for example, acetic acid bacteria (acetobacter)), microbial products, etc. are known, and any of them can be used in the present invention. Cellulose fibers derived from plants or microorganisms are preferable, and they are derived from plants. Cellulose fibers are more preferred.

As the chemically modified cellulose that is the raw material of the chemically modified CNF, those that maintain at least a part of the fibrous shape even when dispersed in water or a water-soluble organic solvent are used. Nanofibers cannot be obtained if fibrous shapes are not maintained (ie, those that dissolve in a dispersion medium). The fact that at least a part of the fibrous shape is maintained when dispersed means that the fibrous substance can be observed by observing the dispersion of chemically modified cellulose with an electron microscope. Further, chemically modified cellulose capable of observing the peak of cellulose type I crystal when measured by X-ray diffraction is preferable.

(Crystallinity of cellulose type I)
The crystallinity of the chemically modified cellulose as a raw material is preferably 40% or more, and more preferably 50% or more for the crystal type I. When the crystallinity of cellulose type I is as high as 40% or more, the thixotropic property becomes high because the proportion of cellulose that does not dissolve in a solvent such as water and maintains the crystal structure when nanofibers are formed is high. It becomes suitable for viscosity adjustment applications such as thixotropy) and thickeners. Further, when it is contained in the cleaning agent, the foam quality is improved, and there is an advantage that fine and highly elastic foam can be obtained. The upper limit of the crystallinity of cellulose type I of chemically modified cellulose is not particularly limited. In reality, about 90% is considered to be the upper limit.

The crystallinity of cellulose can be controlled by the degree of crystallinity of the raw material cellulose and the degree of chemical denaturation. In order to maintain the crystallinity of cellulose I type preferably 40% or more in the chemically modified cellulose nanofibers, it is preferable to use cellulose having a high crystallinity of cellulose I type as a raw material. The crystallinity of cellulose type I of the raw material cellulose is preferably 70% or more, and more preferably 80% or more.

The method for measuring the crystallinity of cellulose type I of chemically modified cellulose and chemically modified CNF is as follows:
The sample is placed on a glass cell and measured using an X-ray diffraction measuring device (LabX XRD-6000, manufactured by Shimadzu Corporation). The crystallinity is calculated using a method such as Segal, and the diffraction intensity of the 002 surface of 2θ = 22.6 ° and the diffraction intensity of 2θ = 2θ = 22.6 ° with the diffraction intensity of 2θ = 10 ° to 30 ° in the X-ray diffraction diagram as the baseline. It is calculated by the following formula from the diffraction intensity of the amorphous part of 18.5 °.

Xc = (I002c-Ia) / I002c × 100
Xc: Cellulose type I crystallinity (%)
I002c: 2θ = 22.6 °, diffraction intensity of 002 surface Ia: 2θ = 18.5 °, diffraction intensity of amorphous part.

The crystallinity of cellulose in carboxymethylated cellulose, which will be described later, can be controlled by the concentration of the mercerizing agent, the temperature at the time of treatment, and the degree of carboxymethylation. Since a high concentration of alkali is used in mercerization and carboxymethylation, type I crystals of cellulose are easily converted to type II, but they are modified by adjusting the amount of alkali (mercerizing agent) used. By adjusting the degree, the desired crystallinity can be maintained.

The proportion of type I crystals in the chemically modified CNF is usually the same as that in the chemically modified cellulose before the defibration treatment.

(Chemical denaturation)
(Carboxyalkylation)
As the chemically modified cellulose, one in which a carboxyalkyl group such as a carboxymethyl group is introduced into cellulose can be used. The carboxyalkyl group in the present invention means -RCOH (acid type) or -RCOM (salt type). Here, R is an alkylene group such as a methylene group and an ethylene group, and M is a metal ion. The carboxyalkylated cellulose may be obtained by a known method, or a commercially available product may be used. The degree of carboxyalkyl substitution of cellulose per anhydrous glucose unit is preferably 0.50 or less. Further, when the carboxyalkyl group is a carboxymethyl group, the degree of carboxymethyl substitution per anhydrous glucose unit of cellulose is preferably 0.50 or less. If the degree of substitution is greater than 0.50, the crystallinity decreases and the proportion of the dissolved component increases, so that the function as a nanofiber is lost. The lower limit of the carboxyalkyl substitution degree and the carboxymethyl substitution degree is preferably 0.01 or more. Considering operability, the degree of substitution is more preferably 0.02 to 0.50, further preferably 0.05 to 0.50, and even more preferably 0.10 to 0.40. ..

In the present invention, the anhydrous glucose unit means individual anhydrous glucose (glucose residue) constituting cellulose. The degree of carboxymethyl substitution (also referred to as the degree of etherification) is the ratio of hydroxyl groups in the glucose residues constituting cellulose that are substituted with carboxymethyl ether groups (carboxymethyl per glucose residue). The number of ether groups) is shown. The degree of carboxymethyl substitution may be abbreviated as DS.

As an example of the method for producing such a carboxyalkylated cellulose, a method including the following steps can be mentioned. The modification is a modification due to a substitution reaction. Carboxymethylated cellulose will be described as an example.
i) The bottoming material, the solvent and the mercerizing agent are mixed and subjected to mercerization treatment at a reaction temperature of 0 to 70 ° C., preferably 10 to 60 ° C., and a reaction time of 15 minutes to 8 hours, preferably 30 minutes to 7 hours. Process,
ii) Next, a carboxymethylating agent is added in an amount of 0.05 to 10.0 times per glucose residue, and the reaction temperature is 30 to 90 ° C., preferably 40 to 80 ° C., and the reaction time is 30 minutes to 10 hours, preferably. A step of carrying out an etherification reaction for 1 to 4 hours.

The above-mentioned cellulose raw material can be used as the bottoming raw material. As the solvent, 3 to 20 times by mass of water or lower alcohol, specifically water, methanol, ethanol, N-propyl alcohol, isopropyl alcohol, N-butanol, isobutanol, tertiary butanol, etc. alone or 2 A mixed medium of seeds or more can be used. When lower alcohols are mixed, the mixing ratio is 60 to 95% by mass. As the mercerizing agent, 0.5 to 20 times mol of alkali metal hydroxide per anhydrous glucose residue of the bottoming material, specifically sodium hydroxide and potassium hydroxide can be used.

As described above, the degree of carboxymethyl substitution per anhydrous glucose unit of cellulose is preferably 0.01 or more and 0.50 or less. By introducing a carboxymethyl substituent into the cellulose, the celluloses electrically repel each other. Therefore, cellulose having a carboxymethyl substituent introduced can be easily nano-deflated. If the carboxymethyl substituent per anhydrous glucose unit is less than 0.01, it is considered that a large amount of energy is required for nanodefibration. The degree of substitution in carboxymethylated cellulose and the degree of substitution in cellulose nanofibers are usually the same.

In the present invention, in the carboxyalkylated cellulose obtained in the above step, the carboxyalkyl group introduced into the cellulose raw material is usually a salt type and is an alkali metal salt such as a sodium salt. Prior to the defibration step, the alkali metal salt of the carboxyalkylated cellulose may be replaced with another cationic salt such as a phosphonium salt, an imidazolinium salt, an ammonium salt or a sulfonium salt. The substitution can be performed by a known method.

In the present specification, "carboxymethylated cellulose", which is a kind of chemically modified cellulose used for preparing cellulose nanofibers, maintains at least a part of the fibrous shape even when dispersed in water. To say. Therefore, it is distinguished from carboxymethyl cellulose, which is a kind of water-soluble polymer. When the aqueous dispersion of "carboxymethylated cellulose" is observed with an electron microscope, a fibrous substance can be observed. On the other hand, even when the aqueous dispersion of carboxymethyl cellulose, which is a kind of water-soluble polymer, is observed, no fibrous substance is observed. In addition, the peak of cellulose I-type crystals can be observed when "carboxymethylated cellulose" is measured by X-ray diffraction, but cellulose I-type crystals are not observed in the water-soluble polymer carboxymethyl cellulose.

(Carboxylation)
Carboxylated (oxidized) cellulose can be used as the chemically modified cellulose. The carboxyl group in the present invention means -COOH (acid type) or -COOM (salt type). Here, M is a metal ion, and examples thereof include sodium and potassium. Carboxylated cellulose (also referred to as "oxidized cellulose") can be obtained by carboxylating (oxidizing) the above-mentioned cellulose raw material by a known method. Although not particularly limited, the amount of carboxyl groups is preferably 0.6 to 3.0 mmol / g, more preferably 1.0 to 2.0 mmol / g, based on the absolute dry mass of the chemically modified cellulose nanofibers. As an example of the carboxylation (oxidation) method, a cellulose raw material is oxidized in water using an oxidizing agent in the presence of an N-oxyl compound and a compound selected from the group consisting of bromide, iodide, and a mixture thereof. You can mention how to do it. By this oxidation reaction, the primary hydroxyl group at the C6 position of the glucopyranose ring on the surface of the cellulose is selectively oxidized, and the cellulose fiber having an aldehyde group and a carboxyl group (-COOH) or a carboxylate group (-COO- ⁾ on the surface. Can be obtained. The concentration of cellulose during the reaction is not particularly limited, but is preferably 5% by mass or less.

The N-oxyl compound is a compound that can generate a nitroxy radical. As the N-oxyl compound, any compound can be used as long as it is a compound that promotes the desired oxidation reaction. For example, 2,2,6,6-tetramethylpiperidine-1-oxy radical (TEMPO) and its derivatives (eg 4-hydroxy TEMPO) can be mentioned. The amount of the N-oxyl compound used is not particularly limited as long as it is a catalytic amount capable of oxidizing the cellulose raw material. For example, 0.01 to 10 mmol is preferable, 0.01 to 1 mmol is more preferable, and 0.01 to 0.5 mmol is further preferable with respect to 1 g of an absolute dry cellulose raw material. Further, about 0.1 to 4 mmol / L is preferable for the reaction system.

Bromide is a compound containing bromine, and examples thereof include alkali metals bromide that can be dissociated and ionized in water. Further, the iodide is a compound containing iodine, and an example thereof includes an alkali metal iodide. The amount of bromide or iodide used can be selected within the range in which the oxidation reaction can be promoted. The total amount of bromide and iodide is, for example, preferably 0.1 to 100 mmol, more preferably 0.1 to 10 mmol, still more preferably 0.5 to 5 mmol with respect to 1 g of an absolute dry cellulose raw material. The modification is a modification due to an oxidation reaction.

As the oxidizing agent, known ones can be used, and for example, halogen, hypohalogenic acid, subhalogenic acid, perhalonic acid or salts thereof, halogen oxide, peroxide and the like can be used. Of these, sodium hypochlorite, which is inexpensive and has a low environmental impact, is preferable. The appropriate amount of the oxidizing agent to be used is, for example, preferably 0.5 to 500 mmol, more preferably 0.5 to 50 mmol, still more preferably 2.5 to 25 mmol with respect to 1 g of the dry dry cellulose raw material. Further, for example, 1 to 40 mol is preferable with respect to 1 mol of the N-oxyl compound.

In the oxidation process of the cellulose raw material, the reaction can proceed efficiently even under relatively mild conditions. Therefore, the reaction temperature is preferably 4 to 40 ° C, and may be room temperature of about 15 to 30 ° C. As the reaction progresses, a carboxyl group is generated in the cellulose, so that the pH of the reaction solution decreases. In order to allow the oxidation reaction to proceed efficiently, it is preferable to add an alkaline solution such as an aqueous sodium hydroxide solution to the reaction system at any time to maintain the pH of the reaction solution at 9 to 12, preferably about 10 to 11. Water is preferable as the reaction medium because it is easy to handle and side reactions are unlikely to occur. The reaction time in the oxidation reaction can be appropriately set according to the degree of progress of oxidation, and is usually about 0.5 to 6 hours, for example, about 0.5 to 4 hours.

Further, the oxidation reaction may be carried out in two stages. For example, by oxidizing the oxidized cellulose obtained by filtration after the completion of the first-stage reaction again under the same or different reaction conditions, the cellulose is not inhibited by the salt produced as a by-product in the first-stage reaction. A carboxyl group can be efficiently introduced into the raw material.

The amount of the carboxyl group of the oxidized cellulose can be adjusted by controlling the reaction conditions such as the amount of the oxidizing agent added and the reaction time described above. The amount of carboxyl groups in cellulose oxide and the amount of carboxyl groups in the case of cellulose nanofibers are usually the same.

In the present invention, in the oxidized cellulose obtained in the above step, the carboxyl group introduced into the cellulose raw material is usually a salt type and is an alkali metal salt such as a sodium salt. Prior to the defibration step, the alkali metal salt of cellulose oxide may be replaced with other cationic salts such as phosphonium salt, imidazolinium salt, ammonium salt and sulfonium salt. The substitution can be performed by a known method.

(Esterification)
Esterified cellulose can also be used as the chemically modified cellulose. Examples thereof include a method of mixing a powder or an aqueous solution of a phosphoric acid-based compound A with a cellulose raw material, a method of adding an aqueous solution of a phosphoric acid-based compound A to a slurry of a cellulose raw material, and the like. Examples of the phosphoric acid-based compound A include phosphoric acid, polyphosphoric acid, phosphite, phosphonic acid, polyphosphonic acid, and esters thereof. These may be in the form of salts. Among the above, a compound having a phosphoric acid group is preferable because it is low in cost, easy to handle, and the phosphoric acid group can be introduced into the cellulose of the pulp fiber to improve the defibration efficiency. Compounds having a phosphoric acid group include phosphoric acid, sodium dihydrogen phosphate, disodium hydrogen phosphate, trisodium phosphate, sodium pyrophosphate, sodium metaphosphate, potassium dihydrogen phosphate, dipotassium hydrogen phosphate, and phosphorus. Examples thereof include tripotassium acid, potassium pyrophosphate, potassium metaphosphate, ammonium dihydrogen phosphate, diammonium hydrogen phosphate, triammonium phosphate, ammonium pyrophosphate, ammonium metaphosphate and the like. These can be used alone or in combination of two or more to introduce a phosphate group. Of these, phosphoric acid, sodium salt of phosphoric acid, potassium salt of phosphoric acid, and phosphoric acid from the viewpoint of high efficiency of introduction of phosphoric acid group, easy defibration in the following defibration step, and easy industrial application. Ammonium salt is preferred. In particular, sodium dihydrogen phosphate and disodium hydrogen phosphate are preferable. Further, it is desirable to use the phosphoric acid-based compound A as an aqueous solution because the reaction can proceed uniformly and the efficiency of introducing the phosphoric acid group is high. The pH of the aqueous solution of the phosphoric acid-based compound A is preferably 7 or less because the efficiency of introducing the phosphoric acid group is high, but the pH is preferably 3 to 7 from the viewpoint of suppressing the hydrolysis of the pulp fiber.

The following methods can be mentioned as examples of the method for producing phosphoric acid esterified cellulose. A phosphoric acid-based compound A is added to a suspension of a cellulosic raw material having a solid content concentration of 0.1 to 10% by mass with stirring to introduce a phosphoric acid group into the cellulose. When the cellulose raw material is 100 parts by mass, the amount of the phosphoric acid compound A added is preferably 0.2 to 500 parts by mass and more preferably 1 to 400 parts by mass as the amount of the phosphorus element. When the ratio of the phosphoric acid-based compound A is at least the above lower limit value, the yield of the fine fibrous cellulose can be further improved. However, if the upper limit is exceeded, the effect of improving the yield will reach a plateau, which is not preferable from the viewpoint of cost.

In addition to the phosphoric acid-based compound A, a powder or an aqueous solution of compound B may be mixed. The compound B is not particularly limited, but a nitrogen-containing compound showing basicity is preferable. "Basic" here is defined as the aqueous solution exhibiting a pink to red color in the presence of a phenolphthalein indicator, or the pH of the aqueous solution being greater than 7. The basic nitrogen-containing compound used in the present invention is not particularly limited as long as the effect of the present invention is exhibited, but a compound having an amino group is preferable. For example, urea, methylamine, ethylamine, trimethylamine, triethylamine, monoethanolamine, diethanolamine, triethanolamine, pyridine, ethylenediamine, hexamethylenediamine and the like can be mentioned. Of these, urea, which is low in cost and easy to handle, is preferable. The amount of compound B added is preferably 2 to 1000 parts by mass, more preferably 100 to 700 parts by mass, based on 100 parts by mass of the solid content of the cellulose raw material. The reaction temperature is preferably 0 to 95 ° C, more preferably 30 to 90 ° C. The reaction time is not particularly limited, but is about 1 to 600 minutes, more preferably 30 to 480 minutes. When the conditions of the esterification reaction are within these ranges, it is possible to prevent the cellulose from being excessively esterified and easily dissolved, and the yield of the phosphate esterified cellulose becomes good. After dehydrating the obtained phosphoric acid esterified cellulose suspension, it is preferable to heat-treat it at 100 to 170 ° C. from the viewpoint of suppressing hydrolysis of cellulose. Further, it is preferable to heat at 130 ° C. or lower, preferably 110 ° C. or lower while water is contained in the heat treatment, remove water, and then heat-treat at 100 to 170 ° C.

The degree of phosphate group substitution per glucose unit of the phosphate-esterified cellulose is preferably 0.001 or more and less than 0.40. By introducing a phosphate group substituent into cellulose, the celluloses electrically repel each other. Therefore, cellulose having a phosphate group introduced can be easily nano-deflated. If the degree of phosphate substitution per glucose unit is less than 0.001, nano-defibration cannot be sufficiently performed. On the other hand, if the degree of phosphate substitution per glucose unit is larger than 0.40, it may not be obtained as nanofibers because it swells or dissolves. In order to efficiently perform defibration, it is preferable that the phosphoric acid esterified cellulose raw material obtained above is washed by boiling and then washing with cold water. These esterification modifications are substitution reaction modifications. The degree of substitution in phosphoric acid esterified cellulose and the degree of substitution in the case of cellulose nanofibers are usually the same.

In the present invention, in the phosphoric acid esterified cellulose obtained in the above step, the phosphoric acid group introduced into the cellulose raw material is usually a salt type and is an alkali metal salt such as a sodium salt. Prior to the defibration step, the alkali metal salt of the phosphate esterified cellulose may be replaced with another cationic salt such as a phosphonium salt, an imidazolinium salt, an ammonium salt or a sulfonium salt. The substitution can be performed by a known method.

(Dissolution into nanofibers)
By defibrating the chemically modified cellulose obtained by the above method, it can be converted into cellulose nanofibers having a nanoscale fiber diameter.

At the time of defibration, prepare a dispersion of chemically modified cellulose obtained by the above method. Water is preferable as the dispersion medium because of its ease of handling. The concentration of the chemically modified cellulose in the dispersion at the time of defibration is preferably 0.01 to 10% (w / v) in consideration of the efficiency of defibration and dispersion.

The device used for defibrating chemically modified cellulose is not particularly limited, but a device such as a high-speed rotary type, a colloid mill type, a high-pressure type, a roll mill type, or an ultrasonic type can be used. At the time of defibration, it is preferable to apply a strong shearing force to the dispersion of chemically modified cellulose. In particular, in order to efficiently defibrate, it is preferable to use a wet high-pressure or ultra-high pressure homogenizer capable of applying a pressure of 50 MPa or more to the dispersion and applying a strong shearing force. The pressure is more preferably 100 MPa or more, still more preferably 140 MPa or more. Further, prior to the defibration and dispersion treatment with a high-pressure homogenizer, the dispersion may be pretreated, if necessary, using a known mixing, stirring, emulsifying, and dispersing device such as a high-speed shear mixer. ..

A high-pressure homogenizer is a pump that pressurizes (high pressure) the fluid and ejects it from a very delicate gap provided in the flow path, so that it is emulsified and dispersed by the total energy such as collision between particles and shearing force due to pressure difference. , A device for crushing, crushing, and ultra-fine particles.

In the present invention, the chemically modified cellulose nanofibers may be used in the state of a dispersion, or may be dried (removed of the dispersion medium), pulverized, and classified and used as a powder.

When the chemically modified cellulose nanofiber used in the present invention is used as a powder, it may contain other components, if necessary. For example, when producing a powder, it is preferable to allow a water-soluble polymer to coexist with a dispersion of chemically modified cellulose nanofibers before drying because the redispersibility is improved. The reason why the water-soluble polymer improves the redispersibility is not clear, but the water-soluble polymer covers the low charge density portion of the surface of the chemically modified cellulose nanofibers and suppresses the formation of hydrogen bonds during drying. It is presumed that this is to prevent the aggregation of the nanofibers.

(Water-soluble polymer)
When chemically modified cellulose nanofibers are used as powder, examples of the water-soluble polymer that can coexist during the production of the powder include cellulose derivatives (carboxymethyl cellulose, methyl cellulose, hydroxypropyl cellulose, ethyl cellulose), xanthan gum, xylolcan, and the like. Dextrin, dextran, carrageenan, locust bean gum, alginic acid, alginate, purulan, starch, shavings, debris, processed starch (cationized starch, phosphorylated starch, phosphoric acid cross-linked starch, phosphoric acid monoesterified phosphoric acid cross-linked starch, hydroxypropyl starch) , Hydroxypropylated Phosphate Crosslinked Starch, Acetylated Adipic Acid Crosslinked Starch, Acelated Phosphoric Acid Crossed Starch, Acetylized Oxidized Starch, Sodium Octenyl Succinate, Acetate Starch, Oxidized Starch), Corn Starch, Arabic Gum, Locust Bean Gum, Gellan Gum, Poly Dextrose, starch, chitin, water-soluble chitin, chitosan, casein, albumin, soybean protein solution, peptone, polyvinyl alcohol, polyacrylamide, sodium polyacrylic acid, polyvinylpyrrolidone, vinylacetate, polyamino acid, polylactic acid, polyapple 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 cross-linked polymer, poly Includes acrylates, starch polyacrylic acid copolymers, tamarind gum, guar gum and colloidal silica and mixtures thereof. Among these, cellulose derivatives are preferable from the viewpoint of affinity with chemically modified cellulose nanofibers, and carboxymethyl cellulose and salts thereof are particularly preferable. It is considered that water-soluble polymers such as carboxymethyl cellulose and its salts penetrate between chemically modified cellulose nanofibers and widen the distance between the nanofibers to improve redispersibility.

When carboxymethyl cellulose or a salt thereof is used as the water-soluble polymer, it is preferable to use carboxymethyl cellulose having a degree of carboxymethyl substitution per anhydrous glucose unit of 0.55 to 1.6, preferably 0.55 to 1.1. Those of 0.65 to 1.1 are more preferable, and those of 0.65 to 1.1 are further preferable. Further, a molecule having a long molecule (high viscosity) is preferable because it has a high effect of widening the distance between nanofibers. The B-type viscosity of carboxymethyl cellulose in a 1% by mass aqueous solution at 25 ° C. and 60 rpm is preferably 3 mPa · s to 14000 mPa · s, more preferably 7 mPa · s to 14000 mPa · s, and 1000 mPa · s to 8000 mPa · s. More preferred. Since the "carboxymethyl cellulose or a salt thereof" as the water-soluble polymer referred to here is completely soluble in water, the fiber shape can be confirmed in the above-mentioned water. Distinguished from fiber.

The blending amount of the water-soluble polymer is preferably 5% by mass to 300% by mass, more preferably 20% by mass to 300% by mass, and 25% by mass with respect to the chemically modified cellulose nanofiber (absolute dry solid content). % To 200% by mass is more preferable, and 25% by mass to 60% by mass is further preferable. When a water-soluble polymer is blended in an amount of 5% by mass or more, the effect of improving redispersibility can be obtained. On the other hand, if the blending amount of the water-soluble polymer exceeds 300% by mass, problems such as viscosity characteristics such as thixotropy characteristic of chemically modified cellulose nanofibers and deterioration of dispersion stability may occur. When the blending amount of the water-soluble polymer is 25% by mass or more, particularly excellent redispersibility can be obtained, which is preferable. Further, considering the thixotropy property, it is preferably 200% by mass or less, and particularly preferably 60% by mass or less.

(Dry)
A dry solid containing chemically modified cellulose nanofibers by drying (removing the dispersion medium) a dispersion of chemically modified cellulose nanofibers or, in some cases, a dispersion of chemically modified cellulose nanofibers mixed with a water-soluble polymer. To get. At this time, it is preferable to adjust the pH of the dispersion to 9 to 11 and then dry it because the redispersibility is further improved.

As the drying method, a known method can be used and is not particularly limited. For example, spray drying, squeezing, air drying, hot air drying, and vacuum drying can be mentioned. The drying device is not particularly limited, but is a continuous tunnel drying device, a band drying device, a vertical drying device, a vertical turbo drying device, a multi-stage disk drying device, an aeration drying device, a rotary drying device, an air flow drying device, and a spray. Dryer dryer, spray dryer, cylindrical dryer, drum dryer, belt dryer, screw conveyor dryer, rotary dryer with heating tube, vibration transport dryer, batch type box dryer, aeration dryer, vacuum A box-type drying device, a stirring drying device, or the like can be used alone or in combination of two or more.

Among these, by using a device that forms a thin film and performs drying, heat energy can be uniformly directly supplied to the object to be dried, and the drying process can be performed more efficiently and in a short time, so that energy efficiency is achieved. It is preferable from the point of view. Further, an apparatus for forming a thin film and drying it is preferable because the dried product can be immediately recovered by a simple means such as scraping the thin film. Furthermore, it was also found that the redispersibility was further improved when the thin film was formed and then dried. Examples of the device for forming and drying a thin film include a drum drying device and a belt drying device for forming a thin film on a drum or a belt with a blade, a die, or the like and drying the thin film. The film thickness of the thin film when the thin film is formed and dried is preferably 50 μm to 1000 μm, more preferably 100 μm to 300 μm. When it is 50 μm or more, it is easy to scrape after drying, and when it is 1000 μm or less, the effect of further improving the redispersibility can be seen.

The residual water content after drying is preferably 2% by mass to 15% by mass with respect to the entire dried product.

(Crushing)
The pulverization method is not particularly limited, and a known method can be used, and examples thereof include a dry pulverization method in which treatment is performed in the form of powder and a wet pulverization method in which treatment is performed in the state of being dispersed or dissolved in a liquid. When wet pulverization is performed, it may be performed before the above-mentioned drying.

The device used in the dry pulverization method is not limited to these, and examples thereof include a cutting type mill, an impact type mill, an air flow type mill, and a medium type mill. These can be processed individually or in combination, and in several stages with the same model. Of these, the airflow type mill is preferable. Cutting mills include mesh mills (Horai Co., Ltd.), Atoms (Yamamoto Hyakuba Co., Ltd.), knife mills (Palman Co., Ltd.), granulators (Hellbolt Co., Ltd.), and rotary cutter mills (Nara Co., Ltd.). (Made by Machinery Manufacturing Co., Ltd.), etc. are exemplified. Impact mills include Palperizer (manufactured by Hosokawa Micron Co., Ltd.), Fine Impact Mill (manufactured by Hosokawa Micron Co., Ltd.), Supermicron Mill (manufactured by Hosokawa Micron Co., Ltd.), Sample Mill (manufactured by Seishin Co., Ltd.), and Bantam Mill (manufactured by Seishin Co., Ltd.). Examples include Seishin Co., Ltd.), Atomizer (Seishin Co., Ltd.), Tornado Mill (Nikkiso Co., Ltd.), Turbo Mill (Turbo Industry Co., Ltd.), Bevel Impactor (Aikawa Iron Works Co., Ltd.), and the like. Airflow type mills include CGS type jet mill (manufactured by Mitsui Mine Co., Ltd.), jet mill (manufactured by Misho Industry Co., Ltd.), Ebara Jet Micronizer (manufactured by Ebara Corporation), and selenium mirror (Masuyuki Sangyo Co., Ltd.). (Manufactured by Nippon Pneumatic Industries Co., Ltd.), supersonic jet mill (manufactured by Nippon Pneumatic Industries Co., Ltd.), etc. are exemplified. Examples of the medium mill include a vibration ball mill and the like. Examples of the apparatus used in the wet pulverization method include a mass colloider (manufactured by Masuyuki Sangyo Co., Ltd.), a high-pressure homogenizer (manufactured by Sanmaru Kikai Kogyo Co., Ltd.), and a medium mill. As the medium mill, a bead mill (manufactured by IMEX Co., Ltd.) and the like can be exemplified.

(Classification)
After pulverizing the chemically modified cellulose nanofibers, classification is performed to adjust the particle size to a specific size. The classification method is not particularly limited, but can be performed, for example, by passing through a mesh (sieve) having a predetermined opening. As the mesh, preferably 20 to 400 mesh, more preferably 40 to 300 mesh, still more preferably 60 to 200 mesh can be used, and these may be used in a multi-stage system. The median diameter of the finally obtained powder is 10.0 μm to 150.0 μm, preferably 30.0 μm to 130.0 μm, and more preferably 50.0 μm to 120.0 μm.

(Cleaning fee)
The components other than the cellulose nanofibers used in the cleaning agent of the present invention can be used without particular limitation as long as they are components generally used in the cleaning agent. Examples of the main agent of the detergency component that can be used in the cleaning agent of the present invention include potash ken substrate, fatty acid sodium, fatty acid potassium, alpha sulfo fatty acid ester sodium, linear alkylbenzene sulfonate sodium, alkyl sulfate ester sodium, and alkyl. Sodium ether sulfate, sodium alphaolefin sulfonate, sodium alkylsulfonate, sucrose fatty acid ester, glycerin fatty acid ester, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, fatty acid alkanolamide, polyoxyethylene alkyl ether, polyoxyethylene alkyl Examples thereof include those containing surface active substances such as phenyl ether, sodium alkylamino fatty acid, alkyl betaine, alkylamine oxide, alkyltrimethylammonium salt, dialkyldimethylammonium salt, and polyglyceryl-4 lauryl ether. Examples of the auxiliary agent include sodium carbonate, sodium silicate, zeolite, citric acid and its salt, EDTA (ethylenediaminetetraacetic acid) and its salt, hydroxyethanephosphonic acid, L-aspartate diacetic acid (ASDA), L-. Examples thereof include glutamate diacetic acid (GLDA) and sodium sulfate. Further, the cleaning agent of the present invention may contain, for example, glycerin, propanediol, polyethylene glycol, thickener, preservative, moisturizer, oil, fragrance, water, ethanol and the like, if necessary.

In the present invention, the content of the cellulose nanofibers is preferably 0.05% by mass or more and 5% by mass or less, and more preferably 0.05% by mass or more and 3% by mass or less in terms of solid content, based on the total cleaning agent. .. If it is 0.05% by mass or less, the function of CNF is not sufficiently exhibited, and if it is 5% by mass or more, the viscosity is high and the workability is deteriorated.

The cleaning agent of the present invention can be used as, for example, a washing pigment, a cleansing cosmetic, a soap, a shampoo, a hand soap or a body soap. The shape that the cleaning agent of the present invention can take is not particularly limited, and it does not matter whether it is in the form of powder, solid, cream, gel, or liquid. For the cleaning agent of the present invention, raw materials and the like can be appropriately selected depending on the intended use and dosage form, and the blending ratio and addition amount can be changed.

Since the cleaning agent of the present invention contains cellulose nanofibers, it has an excellent cleaning effect. The reason why this effect can be obtained with respect to the cleaning agent of the present invention is not clear, but it is because the finer foam makes it easier to absorb and adsorb skin stains, and the elasticity of the foam improves the cleaning efficiency. It is speculated that there is no such thing.

(Manufacturing method of cleaning agent)
The cleaning agent of the present invention is produced by a method in which cellulose nanofibers and components that can be used in the above-mentioned cleaning agent are weighed and mixed at a ratio according to the intended use. As the manufacturing equipment and manufacturing conditions, known manufacturing equipment and manufacturing conditions can be adopted depending on the properties of the cleaning agent and the intended use.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited thereto.

(Measurement method of carboxymethyl substitution)
1) About 2.0 g of carboxymethylated cellulose fiber (absolutely dried) was precisely weighed and placed in a 300 mL Erlenmeyer flask with a stopper.
2) 100 mL of a solution prepared by adding 100 mL of special grade concentrated nitric acid to 1000 mL of methanol nitrate was added, and the mixture was shaken for 3 hours to change the carboxymethyl cellulose salt (CM-modified cellulose) into hydrogen-type CM-modified cellulose.
3) 1.5 to 2.0 g of hydrogen-type CM-formed cellulose (absolutely dried) was precisely weighed and placed in a 300 mL Erlenmeyer flask with a stopper.
4) The hydrogen-type CM-formed cellulose was moistened with 15 mL of 80% methanol, 100 mL of 0.1 N NaOH was added, and the mixture was shaken at room temperature for 3 hours.
5) Excess NaOH was back titrated with 0.1 N H ₂ SO ₄ using phenolphthalein as an indicator.
6) The degree of carboxymethyl substitution (DS) was calculated by the following equation:
A = [(100 x F'-(0.1 N H ₂ SO ₄ ) (mL) x F) x 0.1] / (absolute dry mass (g) of hydrogen-type CM-formed cellulose)
DS = 0.162 x A / (1-0.058 x A)
A: 1N NaOH amount (mL) required to neutralize 1 g of hydrogen-type CM-formed cellulose
F': 0.1N H ₂ SO ₄ factor F: 0.1N NaOH factor

(Measuring method of average fiber diameter and aspect ratio)
The average fiber diameter and average fiber length of CNF were analyzed for 200 randomly selected fibers using an atomic force microscope (AFM). The aspect ratio was calculated by the following formula.
Aspect ratio = average fiber length / average fiber diameter

(Example 1)
(Manufacturing of carboxymethylated cellulose nanofibers)
To a 5 L biaxial kneader whose rotation speed was adjusted to 100 rpm, 1089 parts of isopropanol (IPA) and 31 parts of sodium hydroxide dissolved in 121 parts of water were added, and hardwood pulp (manufactured by Nippon Paper Industries, Ltd.). LBKP) was charged in 200 parts by the dry mass when dried at 100 ° C. for 60 minutes. Mercerized cellulose was prepared by stirring and mixing at 30 ° C. for 60 minutes. After further stirring, 117 parts of monochloroacetate sodium was added, and the mixture was stirred at 30 ° C. for 30 minutes, then heated to 70 ° C. over 30 minutes, and carboxymethylated 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 completion of the reaction, the reaction was neutralized, washed with 65% hydrous methanol, deflated, dried and pulverized, and the sodium salt of carboxymethylated cellulose having a carboxymethyl substitution degree of 0.27 and a cellulose type I crystallinity of 64%. Got The method for measuring the degree of carboxymethyl substitution and the degree of crystallization of cellulose type I is as described above.

The obtained sodium salt of carboxymethylated cellulose was dispersed in water to obtain a 1% (w / v) aqueous dispersion. This was treated three times with a high-pressure homogenizer at 150 MPa 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.

(Manufacturing of CNF powder 1)
The obtained carboxymethyl cellulose nanofibers were made into a dispersion having a solid content of 0.7% by mass with water, and carboxymethyl cellulose (manufactured by Nippon Paper Co., Ltd., trade name: F350HC-4, viscosity (1% by mass, 25 ° C.), 60 rpm) about 3000 mPa · s, carboxymethyl substitution degree about 0.90) is 40% by mass with respect to the carboxymethylated cellulose nanofiber (that is, when the solid content of the carboxymethyl cellulose nanofiber is 100 parts by mass). The solid content of carboxymethyl cellulose was 40 parts by mass), and the mixture was stirred with a TK homomixer (12,000 rpm) for 60 minutes.

After adding 0.5% by mass of an aqueous sodium hydroxide solution to this dispersion and adjusting the pH to 9, it was applied to 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 the dried product was pulverized at a rate of 10 kg per hour using an impact mill to obtain a dried product having a water content of 5% by mass. The obtained pulverized product was classified using 30 mesh to obtain a powder containing carboxymethylated cellulose nanofibers and carboxymethyl cellulose (CNF powder 1).

(Manufacturing of cleaning fee)
Cleaning agents were prepared according to the formulations shown in Table 1. Specifically, the CNF powder 1 obtained above was dispersed with propanediol. Next, the aqueous layer containing the propanediol dispersion of CNF powder 1 and the oil layer were each heated to 80 ° C. The aqueous layer and the oil layer were mixed and stirred using a homomixer at 5000 rpm for 1 minute. Potassium stone Ken substrate was added to this, and manual stirring was performed. Finally, K hydroxide was added to form a ken, and the mixture was cooled with stirring until the temperature became 40 ° C. or lower to obtain Cleaning Agent 1.

(Comparative Example 1)
Cleaning agents were prepared according to the formulations shown in Table 2. Specifically, the cleaning agent 2 was obtained in the same manner as in Example 1 except that the CNF powder 1 was not used and the aqueous layer containing propanediol was used.

The cleaning rates obtained in the examples and comparative examples were evaluated by the following method. The results are shown in Table 3.

(Washing rate)
Apply pseudo-sebum (composition: tri (caprylic acid / caprylic acid / myristic acid / stearic acid) glyceryl = 99.0%, black iron oxide = 1.0%) evenly to Bioskin manufactured by Bulux Co., Ltd. with your fingers. Then, it was leveled with warm air. The cleaning agent was diluted to 10% with purified water, stirred by hand, and then whipped with a vortex mixer. A lathered cleaning agent was placed on the pseudo-sebum, rubbed with a fingertip, and then rinsed with running water.
Using a color difference meter, the L * value (brightness) before, after applying the pseudo-sebum, and after washing with running water was measured, and the cleaning rate was determined by the following formula.
Cleaning rate (%) = (BC) ÷ (BA) x 100
Here, A to C indicate the following values.
A: L * value before application of pseudo-sebum B: L * value after application of pseudo-sebum C: L * value after washing with running water Note that the L * values before applying pseudo-sebum and after washing with running water can be changed in different places. The average value measured three times was used. The L * value after application of pseudo-sebum is prepared for measurement after application separately from for cleaning, and the average value measured 5 times at different locations is used to calculate the cleaning rate of cleaning charges 1 and 2. board. Further, the larger the L * value, the brighter the image.

(Observation using a microscope)
At the time of evaluation of the cleaning rate, the surface of the bioskin was also observed. The observation was carried out using a microscope manufactured by KEYENCE CORPORATION under the condition of a magnification of 100 times. The result before application of pseudo-sebum is shown in FIG. 1, the result after application of pseudo-sebum is shown in FIG. 2, the result after washing with running water using the cleaning agent 1 of Example 1 is shown in FIG. 3, and the cleaning agent 2 of Comparative Example 1 is shown. The results after washing with running water used are shown in FIG. 4, respectively. Each observation was performed 4 times at different observation locations.

As shown in Table 3, the cleaning agent containing the cellulose nanofibers of Example 1 had a higher cleaning rate and an excellent cleaning effect as compared with the cleaning agent containing no cellulose nanofibers of Comparative Example 1. In addition, from the observation results using a microscope, when the cleaning agent containing cellulose nanofibers of Example 1 was used, the pseudo-sebum was compared with the case of using the cleaning agent containing no cellulose nanofibers of Comparative Example 1. It was confirmed that the effect of removing stains on the surface was very high.

Claims

Cleaning agent containing cellulose nanofibers.
The cleaning agent according to claim 1, which contains the cellulose nanofibers in an amount of 0.05% by mass or more and 5% by mass or less.
The cleaning agent according to claim 1 or 2, wherein the cellulose nanofibers are carboxymethylated cellulose nanofibers.
The third aspect of claim 3, wherein the carboxymethylated cellulose nanofibers have a degree of carboxymethyl substitution per anhydrous glucose unit of cellulose of 0.01 to 0.50 and a degree of crystallinity of cellulose type I of 40% or more. Cleaning fee.
The cleaning agent according to any one of claims 1 to 4, further containing carboxymethyl cellulose.
The cleaning agent according to any one of claims 1 to 5, wherein the cleaning agent is a washing pigment, a cleansing cosmetic, soap, shampoo, hand soap or body soap.