JP5265124B2 - Amorphous cellulose derivative - Google Patents

Description

  The present invention relates to a novel cellulose derivative, and more specifically, has excellent water absorption, water retention, dispersion stability, thixotropic properties, food, medicine / cosmetics, agricultural chemicals, resins, paints, dyeing, papermaking, fibers The present invention relates to carboxymethyl cellulose or salts thereof that can be used in various industrial fields such as civil engineering.

  Microcrystalline cellulose is obtained by hydrolyzing cellulose materials, including natural cellulose such as pulp and linter, with mineral acids such as hydrochloric acid and sulfuric acid to remove non-crystalline parts, and to extract only crystalline parts and purify and dry them. Water-insoluble fine cellulose particles. Microcrystalline cellulose has functions such as water absorption, water retention, shape retention, dispersion stability, and thixotropy, so it is used in the fields of food additives, pharmaceutical excipients, dispersants, fillers, etc. Yes.

  As a method for further improving the performance of microcrystalline cellulose, there is a method in which a carboxymethyl ether group is slightly introduced into the surface to form a water-insoluble cellulose derivative (Patent Documents 1 and 2). However, this method has a practical defect that the crystal part remains in the microcrystalline cellulose particles, so that the water absorption / retention property is still poor, the dispersion stability in water is lowered, and sedimentation easily occurs. . On the other hand, a method using natural cellulose or lignocellulose as a raw material is also disclosed (Patent Document 3), but a product obtained by this method has not yet sufficiently solved the above-mentioned drawbacks.

Japanese Patent Publication No. 45-19438 Japanese Patent Publication No. 3-2881 JP-A-10-251301

  The present invention was devised to solve the problems of the prior art as described above, has excellent water absorption, water retention, dispersion stability, thixotropy, food, medicine / cosmetics, agricultural chemicals, The present invention provides a novel cellulose derivative that can be used in various fields such as resin, paint, dyeing, papermaking, fiber, and civil engineering.

  The present inventors have intensively studied to develop a water-insoluble, water-swellable cellulose derivative exhibiting excellent water absorption, water retention, dispersion stability, and thixotropy. As a result, the carboxymethyl cellulose or its salt, in which the crystal structure of the cellulose is completely destroyed and lightly carboxymethylated, has a carboxymethyl ether group introduced inside, and is excellent in water-insoluble and water-swelling. Showing gender. As a result, it has been found that the desired performance can be satisfied, and the present invention has been made based on this finding.

That is, the present invention provides the following [1] and [2].
[1] A water-insoluble and / or water-swellable carboxymethyl cellulose or a salt thereof, wherein the degree of carboxymethyl substitution per anhydroglucose unit is 0.05 to 0.4 and is amorphous.
[2] The ratio of the value measured using water as a dispersion medium to the value measured using methanol as a dispersion medium is 2.0 or more at a 50% cumulative volume particle diameter measured with a laser diffraction / scattering particle size distribution analyzer. The carboxymethyl cellulose or the salt thereof according to [1], which is characterized in that it exists.

The carboxymethyl cellulose of the present invention or a salt thereof exhibits water insolubility and / or water swellability, and has superior water absorption, water retention, shape retention, touch, and thixotropy compared to conventional carboxymethyl cellulose or a salt thereof. ing. Regarding water absorption, a solution having a high sucrose concentration (about 80%) also exhibits high water absorption, and thus is excellent in preventing stickiness of high sucrose foods and preventing deliquescence of sugar coating. When used in water, it is possible to improve the dispersion stability, redispersibility, emulsification stability and the like of substances and particles that do not dissolve in water. For example, the effect of improving the stability of suspended particles such as hardly dispersible particles such as carbon black and heavy (easy to settle) particles such as barium sulfate is remarkably excellent. In particular, if carbon black can be suspended and stabilized, it can be used as an additive for conductive paints and the like. Furthermore, the stability of the bubble-like substance in the liquid is also excellent.
Therefore, the carboxymethyl cellulose or salt thereof of the present invention can be used in various industrial fields such as foods, pharmaceuticals / cosmetics, agricultural chemicals, resins, paints, dyeing, papermaking, fibers, civil engineering and the like.
For example, prevention of caking of cocoa and powdered drinks; improvement of dripping properties such as sauces, dressings and ketchup; improvement of foamability of whipped cream; improvement of storage stability of foods with sugar coatings (confectionery etc.) An effect can be obtained. In addition, by blending in cosmetics such as face powder and foundation, it is possible to promote the water supply of sweat and to prevent matting when the cosmetic is applied to the face, the effect of preventing makeup removal, and a matting effect. Furthermore, it can be used for improving the stringiness of toothpaste and preventing rashes on adhesive bandages.

  The carboxymethyl cellulose of the present invention or a salt thereof has a structure in which a hydroxyl group in a glucose residue constituting cellulose is substituted with a carboxymethyl ether group. The carboxyl cellulose may be in the form of a salt, for example, a metal salt such as carboxymethyl cellulose sodium salt. In the present invention, cellulose means a polysaccharide having a structure in which D-glucopyranose (also simply referred to as “glucose residue” or “anhydroglucose”) is linked by β1-4 bonds. Generally, it is classified into natural cellulose, regenerated cellulose, fine cellulose, microcrystalline cellulose excluding the non-crystalline region, etc. from the origin, production method and the like. Examples of natural cellulose include cellulose produced by microorganisms such as bleached or unbleached wood pulp, refined linters, and acetic acid bacteria. The raw material of bleached or unbleached pulp is not specifically limited, For example, wood, cotton, straw, bamboo, etc. are mentioned. The method for producing bleached or unbleached pulp is not particularly limited, and may be a mechanical method, a chemical method, or a method combining two in the middle, such as mechanical pulp, chemical pulp, groundwood pulp, sulfite pulp. And kraft pulp. Furthermore, in addition to pulp for papermaking, dissolved pulp that is chemically purified and mainly used as a main raw material such as artificial fibers and cellophane, which is mainly dissolved in chemicals, may be used. Examples of the regenerated cellulose include those obtained by dissolving cellulose in some solvent such as a copper ammonia solution, a cellulose xanthate solution, and a morpholine derivative and spinning again. Fine cellulose refers to cellulose-based materials such as the above natural cellulose and regenerated cellulose that have been depolymerized by acid hydrolysis, alkali hydrolysis, enzymatic decomposition, explosion treatment, vibration ball mill treatment, etc. What was processed mechanically is illustrated.

In the present invention, the anhydroglucose unit is a unit of carboxymethyl substitution degree, and means an individual anhydroglucose (glucose residue) constituting cellulose. Further, the degree of carboxymethyl substitution (also called degree of etherification) is the ratio of those substituted with carboxymethyl ether groups (—OCH ₂ COOH) out of hydroxyl groups (—OH) in glucose residues constituting cellulose. Show. The degree of carboxymethyl substitution may be abbreviated as DS. The carboxymethyl cellulose or salt thereof of the present invention needs to have a degree of carboxymethyl substitution per anhydroglucose unit of 0.05 to 0.4. When the degree of carboxymethyl substitution is less than 0.05, the water absorption and swelling part derived from the carboxymethyl ether group is not sufficiently formed, and the water absorption, water retention, dispersion stability, thixotropy and the like characteristic of the present invention are achieved. I can't demonstrate it. On the other hand, when it exceeds 0.4, the water-soluble part increases and the dissolution in water tends to occur, and the characteristics of the present invention cannot be fully exhibited.
The degree of carboxymethyl substitution can be confirmed by measuring the amount of base such as sodium hydroxide required to neutralize carboxymethylcellulose in the sample. In this case, in the case of a carboxymethyl ether salt, it is converted into carboxymethyl cellulose in advance before measurement. In the measurement, an indicator such as back titration using a base and an acid, phenolphthalein and the like can be appropriately combined.

  The carboxymethyl cellulose or salt thereof of the present invention is amorphous. Even if the degree of carboxymethyl substitution satisfies the above range, if it is not amorphous, it exhibits sufficient water absorption and water retention due to the remaining crystalline region with poor chemical reactivity and water absorption. I can't.

  It can be confirmed by measurement by X-ray diffraction that carboxymethylcellulose or a salt thereof is amorphous. Specifically, if it is confirmed as a result of the X-ray diffraction measurement that a diffraction peak derived from the crystalline region other than the diffraction peak of 2θ = 18.5 ° derived from the amorphous region does not occur, non-crystalline It can be said that. For example, in cellulose I type crystal, a peak derived from the diffraction intensity of the 002 plane occurs at 2θ = 22.6 ° as measured by X-ray diffraction. On the other hand, in the case of carboxymethyl cellulose or a salt thereof of the present invention, it is necessary that the diffraction peak at 2θ = 22.6 ° disappears even when microcrystalline cellulose is used as a raw material.

The carboxymethylcellulose or salt thereof of the present invention exhibits water insolubility and / or water swellability. That is, it is necessary to show at least one of water insolubility and water swellability, preferably both.
Water-insoluble means that it is not soluble in water at all. For example, if the sample is added to water in an amount of 1 to 2% by weight and the state after stirring for 3 to 6 hours is visually judged and insoluble, it can be judged as insoluble in water.
On the other hand, water swellability indicates that the volume increases (swells) when immersed in water or the like. For example, the ratio of the value measured with water as the dispersion medium to the value measured with methanol as the dispersion medium (measured with water as the dispersion medium) at a 50% cumulative volume particle size measured with a laser diffraction / scattering particle size distribution meter Value / value measured using methanol as a dispersion medium), and the numerical value is preferably 2.0 or more. If it is less than 2.0, water absorption and swelling are insufficient, and there is a possibility that excellent water absorption, water retention, dispersion stability in water and thixotropy cannot be exhibited. The upper limit is not particularly limited as long as carboxymethyl cellulose or a salt thereof is in a range showing water insolubility. The laser diffraction / scattering particle size distribution meter is not particularly limited as long as it can measure water and methanol as dispersion media. For example, Microtrac Model-9220-SRA (manufactured by Nikkiso Co., Ltd.) Etc. can be used.

In producing the carboxymethyl cellulose or a salt thereof of the present invention, a known method for producing carboxymethyl cellulose or a salt thereof can be applied. That is, after processing raw material cellulose with a mercerizing agent (alkali) to prepare mercerized cellulose (alkali cellulose), the carboxymethyl cellulose of the present invention or a salt thereof is produced by adding an etherifying agent and causing an etherification reaction. can do.
As the raw material cellulose, any cellulose can be used as long as it is the above-mentioned cellulose, but those having high cellulose purity are preferable, and it is particularly preferable to use dissolved pulp and linter. By using these, highly pure amorphous carboxymethylcellulose or a salt thereof can be obtained.

  As the mercerizing agent, alkali metal hydroxide salts such as sodium hydroxide and potassium hydroxide can be used. As the etherifying agent, monochloroacetic acid, sodium monochloroacetate or the like can be used.

  The molar ratio of mercerizing agent to etherifying agent in the production method of water-soluble general carboxymethylcellulose (DS 0.5 or more) is 2.00 to 2.45 when monochloroacetic acid is used as the etherifying agent. Generally adopted. The reason is that if it is 2.00 or less, the etherification reaction becomes insufficient, so that unreacted monochloroacetic acid remains and waste occurs, and if it is 2.45 or more, an excessive mercerizing agent and monochloroacetic acid. This is uneconomical because an alkali metal glycolate salt is produced by the side reaction due to.

  However, in order to obtain the carboxymethyl cellulose or a salt thereof of the present invention, it is necessary to introduce a carboxymethyl ether group very lightly. Therefore, if the number of moles of the etherifying agent to be added is lowered, the number of moles of the mercerizing agent to be added is reduced at a generally employed molar ratio. As a result, mercerization inside the cellulose, particularly in the crystal portion with poor chemical reactivity, becomes insufficient, and the crystal structure may not be completely destroyed.

  When preparing the carboxymethyl cellulose or a salt thereof of the present invention, it is necessary to destroy the crystal structure of the inside of the cellulose, particularly a crystal part having poor chemical reactivity, and to carboxymethylate very lightly. Accordingly, it is preferable to add a sufficient mercerizing agent to completely destroy the crystal structure in order to sufficiently form a mercerization inside the cellulose, and to add a small number of moles of the etherifying agent. The addition amount of the mercerizing agent can be adjusted to usually 1.0 to 4.0 mol, preferably 1.2 to 3.0 mol, per anhydroglucose unit of the raw material cellulose. The addition amount of the mercerizing agent is usually excessive with respect to the etherifying agent that can be added in the present invention. Excess mercerizing agent causes side reactions during the etherification reaction and is uneconomical. Therefore, before adding the etherifying agent, the molar ratio of the mercerizing agent remaining in the reaction system to the etherifying agent to be added (merceling agent / etherifying agent) is 2.0 to 3.0, preferably 2 It is preferable that the mercerizing agent is removed by squeezing and draining in advance so as to be 2 to 2.8, or neutralized with a mineral acid, an organic acid or the like.

  A lower alcohol can be mentioned as a solvent used for manufacture of the cellulose derivative of this invention. Specifically, methanol, ethanol, n-propyl alcohol, isopropyl alcohol, n-butanol, isobutanol, tertiary butanol or the like alone or a mixture medium of two or more and water are used. Generally the usage-amount of a solvent can be 3-20 weight times with respect to raw material cellulose. In addition, the ratio of the lower alcohol with respect to the sum total of a lower alcohol and water can be 60 to 95 weight%.

  The mercerization treatment can be performed by mixing raw material cellulose, a solvent, and a mercerizing agent. Under the present circumstances, reaction temperature is 0-70 degreeC normally, Preferably it is 10-60 degreeC. The reaction time is usually 15 minutes to 4 hours, preferably 30 minutes to 2 hours. Thereafter, an etherification treatment is carried out. Before that, if necessary, excess mercerizing agent may be removed by squeezing and draining, or neutralized with a mineral acid or an organic acid. In the etherification treatment, an etherification agent is added to the raw material cellulose to perform an etherification reaction. The properties of the obtained carboxymethyl cellulose or a salt thereof, particularly the degree of carboxymethyl substitution, varies depending on the type of raw cellulose, the solvent composition of the reaction system of the etherification reaction, mechanical conditions, reaction temperature and reaction time, and other factors. Therefore, it is necessary to adjust the reaction conditions, particularly the addition amount of the etherifying agent, so that the degree of substitution is in the range of 0.05 to 0.4. In general, the addition amount of the etherifying agent in the substitution degree can be 0.05 to 1.0 mol per anhydroglucose unit. The reaction temperature of the etherification reaction is usually 50 to 90 ° C, preferably 60 to 80 ° C. The reaction time is usually 30 minutes to 6 hours, preferably 1 hour to 3 hours.

  After completion of the reaction, the remaining alkali metal salt is neutralized with a mineral acid or an organic acid. If necessary, by-product inorganic salts, organic acid salts and the like are removed by washing with water-containing methanol, dried, pulverized and classified to obtain the carboxymethyl cellulose of the present invention or a salt thereof. In particular, when dry pulverization or wet pulverization is performed, more refined carboxymethyl cellulose or a salt thereof can be obtained. Furthermore, the dispersion stability and the thixotropy are further improved, and this is preferable in that the feeling of foreign matter when added to food is drastically improved. Examples of the apparatus used in the dry pulverization include impact mills such as a hammer mill and a pin mill, medium mills such as a ball mill and a tower mill, and jet mills. Examples of the apparatus used in the wet pulverization include apparatuses such as a homogenizer, a mass collider, and a pearl mill.

  Since the carboxymethyl cellulose or salt thereof of the present invention destroys the crystal structure of cellulose and introduces a carboxymethyl ether group not only into the cellulose surface but also into the interior, the hydrophilicity in the interior is also increased. Can easily penetrate into the interior, and exhibits very high water absorption and water retention. In addition, the carboxymethyl cellulose of the present invention or a salt thereof does not dissolve in water, and absorbs and swells to form a gel material having a high volume ratio. Therefore, the dispersion stability in water is extremely high, and a hard cake even when settled. It is easily redispersed without forming.

  Furthermore, carboxymethyl ether groups and cellulose hydroxyl groups are present on the surface of the water-absorbed and swollen gel particles, and gel particles are formed by electrostatic repulsion between anions derived from carboxymethyl ether groups and hydrogen bonding between cellulose hydroxyl groups. The formation of a stable three-dimensional network structure in water also contributes to the development of high dispersion stability.

  In addition, the carboxymethylcellulose of the present invention or a salt thereof develops a structural viscosity resulting from the formation of a three-dimensional network structure in water. The structure is easily destroyed by the share of stirring and the like, and the viscosity rapidly decreases. However, when the stirring is stopped, the structure quickly recovers and thickens, that is, exhibits excellent thixotropic properties.

  Furthermore, in the carboxymethyl cellulose or a salt thereof of the present invention, the crystal structure of cellulose is completely destroyed, and carboxymethyl ether groups are introduced not only on the cellulose surface but also inside. Therefore, it shows high hydrophilicity. Therefore, it absorbs and swells in water to form a gel-like substance with a high volume ratio, and often does not absorb or swell in an organic solvent such as methanol. This change is noticeable when the ratio of the value measured with water as the dispersion medium and the value measured with methanol as the dispersion medium is 2.0 or more when measured with a laser diffraction / scattering particle size distribution analyzer. is there.

  Hereinafter, the embodiments of the present invention will be described by way of examples, but the present invention is not limited thereto. The “parts” indicating the blending amounts all represent “parts by weight”.

Example 1
Add 522 parts of isopropyl alcohol (IPA) and 30 parts of sodium hydroxide in 58 parts of water to a biaxial kneader whose rotational speed is adjusted to 100 rpm, and add commercially available dissolving pulp (NDPS, manufactured by Nippon Paper Chemicals Co., Ltd.) 100 parts were completely dried. After stirring and mixing at 30 ° C. for 90 minutes to prepare mercerized cellulose, 26 parts of acetic acid is added to neutralize excess mercerizing agent. Further, 11 parts of monochloroacetic acid dissolved in 45 parts of 90% IPA was added with stirring, and the mixture was heated to 70 ° C. and subjected to etherification reaction for 90 minutes. After completion of the reaction, neutralization, liquid removal, drying and pulverization were carried out to obtain sodium carboxymethyl cellulose having a degree of carboxymethyl substitution (DS) of 0.16 per anhydroglucose unit.

Example 2
Add 522 parts of isopropyl alcohol (IPA) and 33 parts of sodium hydroxide in 58 parts of water to a biaxial kneader whose rotational speed is adjusted to 100 rpm, and add commercially available dissolving pulp (NDPS, manufactured by Nippon Paper Chemicals Co., Ltd.) 100 parts were completely dried. After stirring and mixing at 30 ° C. for 90 minutes to prepare mercerized cellulose, 16 parts of acetic acid is added to neutralize excess mercerizing agent. Further, 19 parts of monochloroacetic acid dissolved in 45 parts of 90% IPA was added with stirring, and the mixture was heated to 70 ° C. and subjected to an etherification reaction for 90 minutes. After completion of the reaction, the solution was neutralized, drained, dried and pulverized to obtain a sodium carboxymethylcellulose having a DS of 0.28.

Example 3
Add 522 parts of isopropyl alcohol (IPA) and 38 parts of sodium hydroxide in 58 parts of water to a biaxial kneader whose rotational speed is adjusted to 100 rpm, and add commercially available dissolving pulp (NDPS, manufactured by Nippon Paper Chemicals Co., Ltd.) 100 parts were completely dried. After stirring and mixing at 30 ° C. for 90 minutes to prepare mercerized cellulose, 13 parts of acetic acid is added to neutralize excess mercerizing agent. Further, 26 parts of monochloroacetic acid dissolved in 45 parts of 90% IPA was added with stirring, and the mixture was heated to 70 ° C. and subjected to an etherification reaction for 90 minutes. After completion of the reaction, the solution was neutralized, drained, dried and pulverized to obtain a sodium carboxymethyl cellulose having a DS of 0.38.

Comparative Example 1
Add 522 parts of isopropyl alcohol (IPA) and 30 parts of sodium hydroxide in 58 parts of water to a biaxial kneader whose rotational speed is adjusted to 100 rpm, and add commercially available dissolving pulp (NDPS, manufactured by Nippon Paper Chemicals Co., Ltd.) 100 parts were completely dried. After stirring and mixing at 30 ° C. for 90 minutes to prepare mercerized cellulose, 9 parts of monochloroacetic acid dissolved in 45 parts of 90% IPA was added with further stirring, and the mixture was heated to 70 ° C. and subjected to an etherification reaction for 90 minutes. After completion of the reaction, the solution was neutralized, drained, dried and pulverized to obtain a sodium carboxymethyl cellulose having a DS of 0.03.

Comparative Example 2
Add 522 parts of isopropyl alcohol (IPA) and 49 parts of sodium hydroxide in 78 parts of water to a biaxial kneader whose rotational speed is adjusted to 100 rpm, and add commercially available dissolving pulp (NDPS, manufactured by Nippon Paper Chemicals Co., Ltd.) 100 parts were completely dried. After stirring and mixing at 30 ° C. for 90 minutes to prepare mercerized cellulose, 37 parts of monochloroacetic acid dissolved in 45 parts of 90% IPA was further added while stirring, and the mixture was heated to 70 ° C. and subjected to an etherification reaction for 90 minutes. After completion of the reaction, the solution was neutralized, drained, dried and pulverized to obtain a sodium carboxymethyl cellulose having a DS of 0.45.

Comparative Example 3
Add 522 parts of isopropyl alcohol (IPA) and 23 parts of sodium hydroxide in 58 parts of water to a biaxial kneader whose rotational speed is adjusted to 100 rpm, and add commercially available dissolving pulp (NDPS, manufactured by Nippon Paper Chemicals Co., Ltd.) 100 parts were completely dried. After stirring and mixing at 30 ° C. for 90 minutes to prepare mercerized cellulose, 23 parts of monochloroacetic acid dissolved in 45 parts of 90% IPA was added with further stirring, and the mixture was heated to 70 ° C. and subjected to an etherification reaction for 90 minutes. After completion of the reaction, the solution was neutralized, drained, dried and pulverized to obtain a sodium carboxymethylcellulose having a DS of 0.34.

[Measurement of degree of carboxymethyl substitution (DS) per anhydroglucose unit]
About 2.0 g of the sample was precisely weighed and placed in a 300 ml Erlenmeyer flask with a stopper. 100 ml of methanol nitric acid (a solution obtained by adding 100 ml of special concentrated nitric acid to 1 L of anhydrous methanol) was added and shaken for 3 hours to convert sodium carboxymethylcellulose (Na-CMC) to carboxymethylcellulose (H-CMC). The absolute dry H-CMC 1.5-2.0 g was precisely weighed and put into a 300 ml Erlenmeyer flask with a stopper. H-CMC was moistened with 15 ml of 80% methanol, 100 ml of 0.1N NaOH was added, and the mixture was shaken at room temperature for 3 hours. As an indicator, using phenolphthalein was back titrated excess NaOH with 0.1N-H ₂ SO _4. DS was calculated by substituting the amount (ml) of 0.1N—H ₂ SO ₄ required for titration into the following equation.
A = ((100 × F′−0.1N—H ₂ SO ₄ (ml) × F) × 0.1) / absolute dry weight of H-CMC (g)
DS = 0.162 × A / (1-0.058 × A) (mol / C 6)
A: Amount of 1N NaOH required to neutralize 1 g of H-CMC (ml)
F: factor of 0.1N—H ₂ SO ₄
F ′: 0.1N-NaOH factor

[Measurement of crystallinity]
The crystallinity of cellulose type I was determined by measuring the X-ray diffraction of the sample. The X-ray diffraction was measured by placing the sample on a glass cell and using an X-ray diffraction measurement apparatus (RAD-2C system, manufactured by Rigaku Corporation). The crystallinity is calculated by the method of Seagel et al. (L. Seagel, JJ Greery et al, Text. Res. J., 29, 786, 1959) and the method of Kamide et al. (K. Kamide, et al, polymer J., 17, 909, 1985), with the diffraction intensity of 2θ = 4 ° to 32 ° of the X-ray diffraction diagram as the baseline, the diffraction intensity of the 002 plane of 2θ = 22.6 ° and 2θ = It calculated from the following formula from the diffraction intensity of the amorphous portion at 18.5 °.
χ _C = (I _002C −I _a ) / I _002C × 100
χ _C = Crystallinity of cellulose type I (%)
I _002C : 2θ = 22.6 °, diffraction intensity of 002 plane I _a : 2θ = 18.5 °, diffraction intensity of amorphous part

[Measurement of swelling degree]
In a cumulative volume of 50% particle diameter (average particle diameter) measured by a laser diffraction / scattering particle size distribution analyzer (Microtrac Model-9220-SRA, manufactured by Nikkiso Co., Ltd.), water as a swelling solvent is used as a dispersion medium. The ratio of the measured value to the value measured using methanol, which is a non-swelling solvent, as the dispersion medium was defined as the degree of swelling.
[Solubility test]
2 g of sodium carboxymethylcellulose of Examples 1 to 3 and Comparative Examples 1 to 3 was added to 100 ml of water, and after stirring for 3 hours with a stirrer, the state was visually determined. The evaluation was determined as follows. If any part of the sample shows insolubility, the part can be separated, extracted, etc., and used as insoluble carboxymethylcellulose or a salt thereof. Therefore, in the following evaluations, samples with “Δ” in addition to “x” can be judged to show water insolubility.
◯: Dissolved, Δ: Partially dissolved, ×: Insoluble In addition, the carboxymethyl cellulose sodium of Examples 1 to 3 and Comparative Examples 1 to 3 is hereinafter referred to as a sample.

[Water retention test]
The sample dispersion (1% by weight of the sample dispersed in water) is suction filtered through a suitable filtration container called a centrifugal cup, and the whole container is placed in a centrifuge tube of a centrifuge, and 3,000 G, 15 Centrifugal dehydration for minutes. The sample after dehydration was taken out and weighed, and then dried at 105 ° C. to obtain the absolute dry weight. The water retention was calculated from the following equation.
Water retention = (A−B) / B × 100 (%)
A: Sample weight after centrifugal dehydration B: Sample weight after absolutely dry

[Dispersion stability test]
Add 270 g of water to 30 g of the sample, and stir at 8,000 rpm for 5 minutes. 100 ml of this was placed in a 100 ml graduated cylinder and allowed to stand for 24 hours, and then the volume (ml) of the generated supernatant was measured. The smaller the supernatant volume, the higher the dispersion stability.

  As is clear from Table 1, the sodium carboxymethyl cellulose of Examples 1 to 3 showed a high degree of swelling and water retention. Further, in the dispersion stability test, even after 24 hours, there was almost no supernatant liquid, and the dispersion was uniformly dispersed, indicating high dispersion stability. In addition, since the carboxymethylcellulose sodium of Comparative Example 2 was completely dissolved in water, the degree of swelling, water retention, and dispersion stability could not be measured.

[Dispersion stability test of various suspended particles]
1. Dispersion stability of carbon black Carbon black was suspended in water to 1% by weight, and sodium carboxymethylcellulose of Example 2 was added to the suspension so as to have an addition rate shown in Table 2 to prepare a suspension. did. The suspension was placed in a 500 ml graduated cylinder, and immediately after preparation, the dispersion state of carbon black after 10 minutes, 3 days later was judged visually, and evaluated in the following three stages.
○: good dispersion state, Δ: partial sedimentation, x: solid-liquid separation Table 3 shows the results. Moreover, the dispersion state of each sample after 3 days is shown in FIG.

  As apparent from Table 3 and FIG. 1, in the sample to which sodium carboxymethyl cellulose of Example 2 was added, the dispersion state was good even after 3 days, and the effect of improving the stability of suspended particles of carbon black was obtained. confirmed.

2. Dispersion stability of barium sulfate Barium sulfate, water, and sodium carboxymethyl cellulose of Example 2 were added so as to have the addition ratios shown in Table 4 to prepare a suspension. The suspension was placed in a 500 ml graduated cylinder, and immediately after preparation, the dispersion state of barium sulfate 10 minutes later and 5 days later was judged visually, and evaluated in the following three stages.
○: good dispersion state, Δ: partial sedimentation, x: solid-liquid separation Table 5 shows the results. Moreover, the dispersion state of each sample after 5 days is shown in FIG.

  As apparent from Table 5 and FIG. 2, when the carboxymethylcellulose sodium of Example 2 was added, the dispersion state was good even after 5 days, and the effect of improving the stability of suspended particles of barium sulfate was confirmed. .

[Redispersibility test]
A cocoa beverage was prepared according to the formulation shown in Table 6, and after 24 hours, the redispersibility after shaking up, down, once, twice, and three times was visually judged and evaluated in the following three stages.
○: Completely dispersed Δ: Some solid content remains on the bottom surface ×: Most solid content remains on the bottom surface Table 7 shows the results.

  As is clear from Table 7, the sample added with sodium carboxymethylcellulose of Example 2 has no caking and completely disperses when shaken several times. Therefore, it is possible to prevent caking and improve dispersibility of powdered drinks including cocoa. The effect was confirmed.

[Water absorption test at high sucrose concentration]
Sucrose aqueous solutions with sucrose concentrations of 0%, 20%, 40%, and 60% (all adjusted with w / w) were prepared. The sucrose aqueous solution adjusted to 30 ° C. was added little by little to 4 g of sodium carboxymethylcellulose of Example 2. Water absorption was measured with the end point where the water solution that was not absorbed absorbs water and the CMC begins to flow. The amount of water absorption was determined by measuring the amount of water absorbed by the aqueous sucrose solution per gram of sodium carboxymethylcellulose powder. The results are shown in Table 8.

  As is apparent from the results in Table 8, it was found that even a high concentration sucrose solution has a water absorption comparable to that of water and retains the water in sodium carboxymethylcellulose. From this, it is clear that by adding the carboxymethyl cellulose of the present invention or a salt thereof to sugar coating, water can be retained in the sugar coating, and as a result, water does not come out on the surface of the sugar coating, thus preventing stickiness. It is.

FIG. 1 is a graph showing the results of dispersion stability of carbon black in Examples. FIG. 2 is a graph showing the results of dispersion stability of barium sulfate in Examples.

Claims (6)

After adding a mercerizing agent to the raw cellulose and treating the raw cellulose with 1.0 to 4.0 moles of mercerizing agent per anhydroglucose unit to prepare mercerized cellulose , neutralize the mercerizing agent. from obtained by by etherification reaction added et ether agent as mercerized agent and the molar ratio of etherification agent remaining in the reaction system becomes 2.0 to 3.0, per anhydroglucose unit The degree of carboxymethyl substitution is 0.05 to 0.4, and the diffraction peak derived from the crystalline region does not occur other than the diffraction peak of 2θ = 18.5 ° derived from the amorphous region as measured by X-ray diffraction. A water-insoluble and / or water-swellable carboxymethyl cellulose or a salt thereof.   The ratio of the value measured using water as a dispersion medium to the value measured using methanol as a dispersion medium is 2.0 or more at a 50% cumulative volume particle diameter measured by a laser diffraction / scattering particle size distribution meter. The carboxymethyl cellulose or a salt thereof according to claim 1, After adding a mercerizing agent to the raw cellulose and treating the raw cellulose with 1.0 to 4.0 moles of mercerizing agent per anhydroglucose unit to prepare mercerized cellulose , neutralize the mercerizing agent. from then by etherification reaction added et ether agent such that the molar ratio of mercerized agent and etherification agent remaining in the reaction system becomes 2.0 to 3.0, more of claims 1 or 2 A method for producing the water-insoluble and / or water-swellable carboxymethyl cellulose or a salt thereof according to claim 1. An agent for improving the dispersion stability, redispersibility, or emulsion stability of a substance that does not dissolve in water, comprising the water-insoluble and / or water-swellable carboxymethylcellulose or a salt thereof according to claim 1 or 2 as an active ingredient. An agent for improving the storage stability of a food or pharmaceutical product having a sugar coating comprising the water-insoluble and / or water-swellable carboxymethylcellulose or a salt thereof according to claim 1 or 2 as an active ingredient. A foamability improver or a spinnability improver comprising the water-insoluble and / or water-swellable carboxymethylcellulose or salt thereof according to claim 1 or 2 as an active ingredient.