WO2012008314A1

WO2012008314A1 - Method for producing carboxymethyl cellulose

Info

Publication number: WO2012008314A1
Application number: PCT/JP2011/065089
Authority: WO
Inventors: 榊原　誠
Original assignee: 花王株式会社
Priority date: 2010-07-15
Filing date: 2011-06-30
Publication date: 2012-01-19
Also published as: JP2012036375A

Abstract

Disclosed is a method for producing carboxymethyl cellulose, in which after starting material pulp is subjected to a crushing treatment using a crusher, cellulose in the material obtained by the crushing treatment is reacted with a monohaloacetic acid or a salt thereof and an alkaline agent at 40 to 100ºC, the method comprising a step of mixing the monohaloacetic acid or a salt thereof and/or the alkaline agent with the starting material pulp before or during the crushing treatment of the starting material pulp. According to this method, carboxymethyl cellulose, the aqueous solution of which has a high viscosity, can be efficiently produced.

Description

Method for producing carboxymethylcellulose

The present invention relates to a method for producing carboxymethyl cellulose.

Carboxymethylcellulose (hereinafter also referred to as “CMC”) is widely used as a thickener, a dispersant, an emulsifier, a protective colloid agent, a stabilizer, and the like. Industrially, this CMC is produced by a solvent method in which cellulose is treated with a large amount of alkaline water to activate it as alkali cellulose (arcelerization), and then dispersed in a water-containing organic solvent and reacted with monohaloacetic acid. Yes.
Patent Document 1 discloses a method for producing carboxymethyl cellulose or a salt thereof, which includes a step of reacting cellulose and alkali at a temperature of 20 to 50 ° C. to produce alkali cellulose, and a reaction of alkali cellulose and monochloroacetic acid to produce carboxy. A carboxymethyl cellulose having a viscosity of 20 to 1000 (mPa · s) in a 1% by weight aqueous solution is disclosed by a method for producing carboxymethyl cellulose or a salt thereof comprising a step of producing methyl cellulose.
Patent Document 2 discloses a method for producing a cellulose derivative, in which a low crystalline powdery cellulose having a crystallinity of 50% or less is reacted with an organic halide compound in the presence of a base.

JP 2000-34301 A International Publication No. 2009/063856 Pamphlet

However, in the methods disclosed in Patent Documents 1 and 2, it is difficult to easily produce carboxymethylcellulose having a high aqueous solution viscosity and useful as a thickener.
The present invention relates to a method for efficiently producing carboxymethyl cellulose having a high aqueous solution viscosity.

The present invention is a method for producing carboxymethyl cellulose, in which raw pulp is pulverized by a pulverizer, and then cellulose in the obtained pulverized product is reacted with monohaloacetic acid or a salt thereof and an alkali agent at 40 to 100 ° C. The present invention relates to a method for producing carboxymethyl cellulose, comprising a step of mixing the monohaloacetic acid or a salt thereof and / or an alkaline agent with the raw material pulp before or during the pulverizing treatment of the raw material pulp.

According to the method of the present invention, carboxymethyl cellulose having a high aqueous solution viscosity can be efficiently produced.

The present invention is a method for producing carboxymethyl cellulose, in which raw pulp is pulverized by a pulverizer, and then cellulose in the obtained pulverized product is reacted with monohaloacetic acid or a salt thereof and an alkali agent at 40 to 100 ° C. By mixing the monohaloacetic acid or a salt thereof and / or an alkali agent with the raw material pulp before or during the pulverization treatment of the raw material pulp, carboxymethyl cellulose having a high aqueous solution viscosity can be produced efficiently and simply. .
This is because monohaloacetic acid or a salt thereof, and / or an alkaline agent is mixed with the raw pulp before or during the grinding treatment of the raw pulp, so that these monohaloacetic acid or a salt thereof and / or an alkaline agent are mixed. Working as a buffering agent for the pulverization impact of raw material pulp, it is possible to pulverize raw material pulp while suppressing a decrease in the degree of polymerization of cellulose constituting the raw material pulp, and as a result, increase the viscosity of the resulting aqueous solution of carboxymethyl cellulose. It is thought that you can. Furthermore, it is considered that the contact rate between the anhydroglucose unit constituting the cellulose constituting the raw pulp and the monohaloacetic acid or a salt thereof and / or the alkali agent can be increased, and the reaction efficiency is also improved.

Although this invention has a process of mixing monohaloacetic acid or its salt, and / or an alkali agent with this raw material pulp before the grinding | pulverization process of a raw material pulp, or during a pulverization process from a viewpoint of manufacturing carboxymethylcellulose with high aqueous solution viscosity. It is preferable to have the following step 1 and step 2.
Step 1: A step of mixing raw pulp with monohaloacetic acid or a salt thereof and pulverizing with a pulverizer (hereinafter also referred to as “pulverizing step”).
Step 2: A step of reacting the cellulose in the pulverized product obtained in Step 1 with monohaloacetic acid or a salt thereof and an alkali agent at 40 to 100 ° C. to obtain carboxymethyl cellulose (hereinafter also referred to as “reaction step”)
Hereinafter, each process of this invention and each component to be used are demonstrated in detail.

[material]
(Raw pulp)
Examples of raw material pulp that can be used in the present invention include cotton linter, rice straw pulp, and wood pulp. Specifically, linter pulp, N-wood pulp mainly composed of softwood, and L mainly composed of hardwood. Pulp and the like can be used.
The shape of the raw material pulp is not particularly limited, but in the production method of the present invention, the higher the degree of polymerization of the raw material pulp, the higher the degree of polymerization of carboxymethyl cellulose can be obtained. On the other hand, the degree of polymerization of the raw material pulp is lowered by processing such as pulverization. Therefore, from the viewpoint of obtaining carboxymethyl cellulose having a high degree of polymerization, the shape of the raw material pulp is preferably a chip shape. In order to change the shape of the raw material pulp into chips, a shredder (for example, manufactured by Meiko Shokai Co., Ltd., trade name: “MSX2000-IVP440F”) or a sheet pelletizer (for example, manufactured by Horai Co., Ltd., trade name: “SGG-220-”). 3X3 ") can be used. The diameter of the chip is preferably 0.6 to 100 mm, more preferably 0.8 to 30 mm, and more preferably 1 to 10 mm in terms of the number average of 100 long diameters (the longest length of one chip). Further preferred.
The average degree of polymerization of cellulose constituting the raw material pulp is preferably 1000 or more, more preferably 1200 or more, and further preferably 1500 or more, from the viewpoint of developing a high aqueous solution viscosity. The upper limit of the average degree of polymerization is not particularly limited, but is preferably 5000 or less from the viewpoint of availability.
In addition, in this invention, the average degree of polymerization of a cellulose means a viscosity average degree of polymerization, and specifically, it measures by the method as described in an Example.

Several crystal structures are known for cellulose, and the crystallinity is generally calculated from the ratio of the crystal part to the total amount of the amorphous part and the crystal part.
In the present invention, the “crystallinity of cellulose” means the crystallinity derived from the type I crystal structure of natural cellulose, and is calculated by the Segal method from the diffraction intensity value by the powder X-ray crystal diffraction spectrum method. , Defined by the following formula (1).
Cellulose crystallinity (%) = [(I _22.6 -I _18.5 ) / I _22.6 ] × 100 (1)
Wherein, I _22.6 represents the diffraction intensity of the lattice plane of cellulose I type crystal (002 plane) (diffraction angle 2 [Theta] = 22.6 °) in the X-ray diffraction, and I _18.5 is amorphous portion (angle of diffraction 2 [Theta] = 18.5 °). ]
Usually, when the treatment for reducing the crystallinity of the pulp is performed, the degree of polymerization is also reduced, so it is difficult to obtain a pulp having a high average degree of polymerization and a low crystallinity. Therefore, the crystallinity of the cellulose constituting the raw pulp is preferably more than 50% and 95% or less, more preferably 60 to 95%, still more preferably 70 to 95%, from the viewpoint of maintaining a high degree of polymerization. More preferably, it is 75 to 95%.

(Alkaline agent)
The alkali agent used in the present invention is preferably an alkali metal hydroxide or an alkaline earth metal hydroxide from the viewpoint of efficiently converting the hydroxyl groups of cellulose molecules constituting the raw material pulp into alcoholates. Specific examples of the alkali metal hydroxide include sodium hydroxide, potassium hydroxide, lithium hydroxide and the like, and specific examples of the alkaline earth metal hydroxide include magnesium hydroxide and calcium hydroxide. Among these, an alkali metal hydroxide is preferable, and sodium hydroxide or potassium hydroxide is more preferable.
There is no limitation on the form of the alkaline agent. When using an alkali metal hydroxide or alkaline earth metal hydroxide as the alkali agent, an aqueous solution is preferably used from the viewpoint of operation.
The concentration in the case of adding the alkaline agent in the form of an aqueous solution is not particularly limited, but since the reaction step described below is affected by the amount of water, the amount of water after the addition of the alkaline agent exceeded the suitable amount of water in the reaction step. In some cases, it is desirable to perform operations such as dehydration. Therefore, the concentration of the alkaline agent aqueous solution is preferably 10% by mass or more. On the other hand, from the viewpoint of easy availability, the concentration of the alkaline agent aqueous solution is preferably 75% by mass or less. From the above viewpoint, the concentration of the alkaline agent aqueous solution is preferably 10 to 75% by mass, more preferably 20 to 65% by mass, and still more preferably 30 to 55% by mass.

When monohaloacetate is used, the molar equivalent ratio of the alkali agent to the anhydroglucose unit of the cellulose constituting the raw pulp (alkali agent / anhydroglucose unit) is preferably 0.3 to 3 from the viewpoint of developing a high aqueous solution viscosity. More preferably 0.5 to 2, still more preferably 0.5 to 1.8, still more preferably 0.5 to 1.5, and still more preferably 0.5 to 1.2. The number of moles of anhydroglucose units can be determined as a value obtained by dividing the dry weight of cellulose by the molecular weight 162 of anhydroglucose units.
Further, when monohaloacetic acid is used, the alkali agent is consumed for neutralization of monohaloacetic acid, so the molar equivalent ratio of the alkali agent to the anhydroglucose unit of the cellulose constituting the raw pulp (alkali agent / anhydroglucose unit) is high. From the viewpoint of developing the aqueous solution viscosity, it is preferably 0.6 to 6, more preferably 1.0 to 4, and still more preferably 1 to 3.

(Monohaloacetic acid or its salt)
The halogen atom in the monohaloacetic acid used in the present invention is preferably an iodine atom, a bromine atom or a chlorine atom, more preferably a bromine atom or a chlorine atom, still more preferably chlorine, for reasons of reactivity, versatility and ease of handling. Is an atom.
The metal capable of forming a salt of monohaloacetic acid is preferably lithium, potassium or sodium, more preferably potassium or sodium, and still more preferably sodium, from the viewpoint of expressing the water solubility of the resulting carboxymethyl cellulose and high aqueous solution viscosity. .
Specific examples of monohaloacetic acid or a salt thereof used in the present invention include monochloroacetic acid, monobromoacetic acid, sodium monochloroacetate, potassium monochloroacetate and the like, and monochloroacetic acid or sodium monochloroacetate is preferable.
Monohaloacetic acid or a salt thereof may be used in the form of a solid (powder) or may be used after being dissolved in water or a hydrophilic organic solvent described later.
The molar equivalent ratio of monohaloacetic acid or a salt thereof to anhydroglucose unit of cellulose constituting the raw pulp (monohaloacetic acid or a salt thereof / anhydroglucose unit) is preferably 0.3 to 3, from the viewpoint of developing a high aqueous solution viscosity, More preferably, it is 0.5 to 2.0, still more preferably 0.5 to 1.6, and still more preferably 0.6 to 1.0.

Said monohaloacetic acid or its salt, and an alkali agent can be used individually or in combination of 2 types or more, respectively.
The molar equivalent ratio of the alkali agent to the monohaloacetic acid used in the present invention (alkali agent / monohaloacetic acid) is preferably 2 to 3, more preferably 2 to 2, for the reason that the reaction is carried out efficiently while suppressing side reactions. 0.5, more preferably 2 to 2.2, and even more preferably 2 to 2.1.
When a salt of monohaloacetic acid is used, the molar equivalent ratio of the alkaline agent to the monohaloacetic acid salt used in the present invention (alkali agent / monohaloacetic acid salt) is because the reaction is carried out efficiently while suppressing side reactions. , Preferably 1 to 2, more preferably 1 to 1.5, still more preferably 1 to 1.1, still more preferably 1 to 1.05.

[Step 1: Crushing step]
In the pulverization process of the present invention, raw pulp and monohaloacetic acid or a salt thereof are mixed and pulverized. In the present invention, preferably, the raw pulp is pulverized by a pulverizer in the presence of monohaloacetic acid or a salt thereof and an alkali agent. More specifically, monohaloacetic acid or a salt thereof and an alkali agent are mixed before pulverization of the raw pulp or during pulverization, and pulverized.
Examples of the mixing and pulverizing method include the following (1) to (4).
(1) A method in which both monohaloacetic acid or a salt thereof and an alkali agent are mixed with a raw material pulp before pulverizing the raw material pulp and then pulverized. (2) Both monohaloacetic acid or a salt thereof and an alkaline agent are used as the raw material pulp. (3) Monohaloacetic acid or a salt thereof is mixed before or during pulverization of raw pulp, and an alkali agent can be obtained after the pulverization is completed. (4) One of monohaloacetic acid or a salt thereof, or an alkali agent is mixed with raw pulp before the raw pulp is pulverized, and the other is being pulverized during the pulverization How to mix with

The mixing and pulverizing method may be any of the above methods (1) to (4), but from the viewpoint of obtaining carboxymethyl cellulose having a high aqueous solution viscosity, the methods (1), (2) and (4), That is, a method having a step of pulverizing raw pulp with a pulverizer in the presence of monohaloacetic acid or a salt thereof and an alkali agent is preferable, and the method (4) is more preferable.
In this case, the order of adding the raw materials and the order of pulverization are not particularly limited. Monohaloacetic acid or a salt thereof may be added to the raw pulp and pulverized, then an alkali agent may be added, and further pulverized. Alternatively, an alkaline agent may be added to the raw pulp and pulverized, and then the monohaloacetic acid or a salt thereof. And may be further pulverized. The raw pulp, monohaloacetic acid or a salt thereof, and an alkali agent may be mixed at the same time and pulverized. Among these, from the viewpoint of obtaining carboxymethylcellulose having a high aqueous solution viscosity, a method in which raw pulp and monohaloacetic acid or a salt thereof are mixed and pulverized, and then an alkali agent is added and further pulverized is preferable.

Examples of the pulverizer used in the present invention include those shown in Tables 16 and 4 on page 843 of “Chemical Engineering Handbook, Revised Sixth Edition” edited by the Chemical Engineering Society. More specific examples include roll mills such as high pressure compression roll mills and roll rotating mills; rigid roller mills such as ring roller mills, roller race mills or ball race mills; rolling ball mills, vibration ball mills, vibration rod mills, vibration tube mills, planets Container drive medium mill such as ball mill or centrifugal fluidization mill; medium agitation mill such as tower pulverizer, stirring tank mill, flow tank mill or annular mill; compaction shear mill such as high speed centrifugal roller mill or ang mill; A mortar, a stone mill, etc. are mentioned.
Among these, from the viewpoint of productivity, a container-driven medium mill or a medium agitating mill is preferable, a container-driven medium mill is more preferable, and a vibration ball mill, a vibration rod mill, or a vibration tube mill is more preferable.
The processing method may be either a batch type or a continuous type.

There is no restriction | limiting in particular as a material of a grinder and / or a medium, For example, iron, stainless steel, an alumina, a zirconia, a silicon carbide, a silicon nitride, glass etc. are mentioned. Among these, iron, stainless steel, zirconia, silicon carbide, and silicon nitride are preferable from the viewpoint of mixing and grinding efficiency, and iron or stainless steel is more preferable from the viewpoint of industrial use.
From the viewpoint of mixing and pulverization efficiency, when the pulverizer used is a vibration mill and the medium is a rod, the outer diameter of the rod is preferably 0.1 to 100 mm, more preferably 0.5 to 50 mm. Range.
The rod filling rate varies depending on the type of vibration mill, but is preferably in the range of 10 to 97%, more preferably 15 to 95%. If the filling rate of the rod is within this range, the contact frequency between the cellulose or the reactant and the rod can be improved, and the grinding efficiency can be improved without hindering the movement of the medium. Here, the rod filling rate refers to the apparent volume of the rod relative to the volume of the stirring section of the vibration mill.

The pulverization time depends on the pulverization conditions such as the size (volume) of the pulverizer, but is preferably about 3 to 3 hours, more preferably 5 to 60 minutes, from the viewpoint of obtaining carboxymethylcellulose having a high aqueous solution viscosity. Minutes are more preferred.
The temperature during pulverization is preferably 5 ° C. or more and less than 40 ° C., more preferably 5 to 38 ° C., and still more preferably 5 to 35 ° C., from the viewpoint of obtaining carboxymethyl cellulose having a high aqueous solution viscosity. As long as the object of the present invention is not impaired, there may be a portion where the temperature is locally increased during pulverization.

Moreover, it is preferable to further include a step of impregnating the raw pulp with monohaloacetic acid or a salt thereof before the raw pulp is pulverized from the viewpoint of obtaining a carboxymethyl cellulose having a high aqueous solution viscosity by suppressing a decrease in the degree of polymerization.
As an impregnation method, a raw pulp and a solution of monohaloacetic acid or a salt thereof (the solvent is water or a hydrophilic organic solvent liquid) are mixed with a commonly used mixing and stirring device such as a Henschel mixer, an anchor blade, etc. A method for removing the solvent can be used. The solvent can be removed by a general method such as drying under reduced pressure. The drying time under reduced pressure is preferably 6 to 48 hours, more preferably 8 to 24 hours. As the hydrophilic organic solvent, those described later can be used.

(Water content in the grinding process)
In the present invention, the water content in the pulverization treatment step is preferably 10 parts by weight or more with respect to 100 parts by weight of the dry raw material pulp from the viewpoint of suppressing the decrease in the degree of polymerization and obtaining carboxymethyl cellulose having a high aqueous solution viscosity. . On the other hand, the water content is preferably 100 parts by weight or less with respect to 100 parts by weight of the dry raw material pulp from the viewpoint of pulverization efficiency and the water content in the reaction step described later in a suitable range. In view of the above, the water content is preferably 10 to 100 parts by weight, more preferably 10 to 90 parts by weight, further preferably 15 to 80 parts by weight, and more preferably 20 to 60 parts by weight with respect to 100 parts by weight of the dry raw material pulp. Further preferred. By setting the water content in the pulverization process within the above range, aggregation of cellulose can be suppressed, and the subsequent reaction process can be performed while maintaining a good powder state, and further, a decrease in the polymerization degree of the raw material can be suppressed. It becomes possible.

The end point of the pulverization treatment of the raw material pulp is preferably the median diameter of cellulose and / or carboxymethyl cellulose in the pulverized product obtained from the viewpoint of reacting the pulverized product with monohaloacetic acid or a salt thereof and an alkali agent in the next step. As a guide, it can be pulverized to 1 to 800 μm, more preferably 10 to 500 μm, still more preferably 10 to 300 μm, and still more preferably 30 to 250 μm. The method for measuring the median diameter is as described in Examples described later.
The obtained pulverized product is mainly composed of cellulose, but may partially react to become carboxymethylcellulose.

[Step 2: Reaction step]
Next, the cellulose in the obtained pulverized product is reacted with monohaloacetic acid or a salt thereof and an alkali agent at 40 to 100 ° C. to obtain carboxymethylcellulose. Examples of the reaction method include the following (i) to (ii).
(I) When monohaloacetic acid or a salt thereof is mixed before or during pulverization of raw pulp, an alkali agent is added and mixed to the obtained mixed pulverized product, and additional monohalo is added as necessary. A method in which acetic acid or a salt thereof is added and mixed.
(Ii) When monohaloacetic acid or a salt thereof and an alkali agent are mixed before or during the pulverization treatment of the raw pulp, the reaction may be carried out as it is, but if necessary, additional monohaloacetic acid or a salt thereof. And / or an alkali agent can be added and mixed to carry out the reaction.

In the reaction step, it is preferable to use a mixer capable of mixing uniformly. For example, a mixer such as a so-called kneader used for kneading high-viscosity substances such as powders and resins as disclosed in paragraph [0016] of JP-A-2002-114801 is used as the reaction apparatus. Is preferred. Here, the mixer such as a kneader is not particularly limited as long as it can sufficiently stir. For example, the chemical engineering manual edited by “Chemical Engineering Handbook” revised 5th edition (published by Maruzen Co., Ltd.), pages 917 to 919 The mixing machine currently used is mentioned. Specifically, examples of the single-axis kneader include a ribbon mixer, a kneader, a botter, and a screw-type kneader, and examples of the biaxial kneader include a double-arm kneader. It is more preferable that these mixers have a portion where the aqueous base solution can be dropped and dehydrated.
The reaction temperature is from 40 to 100 ° C., preferably from 40 to 80 ° C., more preferably from the viewpoint of allowing the reaction to proceed efficiently while suppressing side reactions and suppressing a decrease in the degree of polymerization of cellulose. ~ 70 ° C.
The reaction atmosphere in the reaction step is preferably carried out in an inert gas atmosphere from the viewpoint of suppressing a decrease in the degree of polymerization of cellulose and expressing a high aqueous solution viscosity. The inert gas is preferably nitrogen, helium or argon, more preferably nitrogen or argon, still more preferably nitrogen.
In the method of the present invention, from the viewpoint of improving the dispersibility of the pulverized product, stirring is preferably performed at 1 to 500 rpm, more preferably 2 to 200 rpm, and still more preferably 5 to 100 rpm.
Although depending on the reaction scale, the reaction time is preferably about 1 to 10 hours, more preferably about 2 to 8 hours.
The end point of the reaction can be taken as a standard when 95% by weight or more of the total amount of monohaloacetic acid or its salt has been consumed, and the progress of the reaction can be confirmed by high performance liquid chromatography (HPLC) or the like. it can.
After completion of the reaction, an aqueous solution of a hydrophilic solvent such as methanol is added to the obtained reaction product, and salts such as NaCl can be removed by filtration after stirring. Carboxymethylcellulose is obtained as a filter cake, and can be washed with acetone and dehydrated efficiently.

(Hydrophilic organic solvent)
From the viewpoint of improving the mixing property of monohaloacetic acid or a salt thereof and raw pulp, a hydrophilic organic solvent may be used in the pulverization treatment step and / or the reaction step.
The hydrophilic organic solvent is preferably one that dissolves 100 g or more in 100 g of water at 25 ° C. from the viewpoint of the reactivity between the raw material pulp and monohaloacetic acid or a salt thereof. The hydrophilic organic solvent that can be used in the method of the present invention is preferably a secondary or tertiary lower alcohol such as isopropanol or tert-butanol; diglyme such as 1,4-dioxane, ethylene glycol dimethyl ether or diethylene glycol dimethyl ether; Examples include ether solvents such as triglyme; hydrophilic polar solvents such as dimethyl sulfoxide, more preferably secondary or tertiary lower alcohols such as isopropanol and tert-butanol, and more preferably isopropanol and tert-butanol.
Said hydrophilic organic solvent can be used individually or in combination of 2 or more types.

The amount of the hydrophilic organic solvent used in the reaction in the present invention is preferably 200 parts by weight or less, more preferably 150 parts by weight or less, still more preferably 100 parts by weight or less, and still more preferably with respect to 100 parts by weight of the dry raw material pulp. Is 50 parts by weight or less, more preferably 30 parts by weight or less. By setting the amount of the hydrophilic organic solvent in the above range, aggregation can be suppressed, the reaction can be allowed to proceed efficiently while maintaining a good powder state, and carboxymethylcellulose having a high aqueous solution viscosity can be obtained.

(Moisture content in the reaction process)
In the present invention, the water content in the reaction step is preferably 100 with respect to 100 parts by weight of the dry raw material pulp from the viewpoint of efficiently alcoholating the hydroxyl groups of the cellulose molecules with an alkali agent and suppressing the aggregation of the pulverized product. The amount is not more than parts by weight, more preferably 10 to 90 parts by weight, still more preferably 15 to 80 parts by weight, still more preferably 20 to 60 parts by weight. By setting the water content in the reaction step within the above range, aggregation of cellulose can be suppressed, the reaction can be efficiently advanced while maintaining a good powder state, and the handleability of the product is excellent.

[Carboxymethylcellulose]
By the method of the present invention, carboxymethylcellulose having a high aqueous solution viscosity is obtained. The obtained carboxymethyl cellulose may be a salt, and the salt is preferably an alkali metal salt such as sodium, potassium or lithium or an alkaline earth metal salt such as magnesium or calcium.
The viscosity of a 1% by weight aqueous solution of carboxymethylcellulose obtained by the method of the present invention (100 mol% neutralized product with sodium salt) (25 ° C.) is preferably 500 mPa · s or more, more preferably from the viewpoint of developing high viscosity. Is at least 700 mPa · s, more preferably at least 800 mPa · s, even more preferably at least 1000 mPa · s, even more preferably at least 1100 mPa · s, even more preferably at least 1750 mPa · s, even more preferably at least 1800 mPa · s. is there. Although there is no particular upper limit, it is preferably 10,000 mPa · s or less and more preferably 5000 mPa · s or less from the viewpoint of handleability. The measuring method of the aqueous solution viscosity is as described in Examples described later. In order to obtain carboxymethylcellulose having a high viscosity, it is preferable to use a raw material pulp containing cellulose having a high degree of polymerization.
Carboxymethyl cellulose obtained by the method of the present invention is useful as a thickener for cosmetics and the like.

Measurement of crystallinity, average polymerization degree and water content of chip-like pulp and cellulose obtained in Production Example, particle size of pulverized product of chip-like pulp, and degree of substitution and aqueous solution viscosity of carboxymethylcellulose obtained in Examples Was carried out by the following method. “%” Is “% by weight”.

(1) Calculation of crystallinity The crystallinity of cellulose in raw pulp or pulverized material is measured using the raw pulp or pulverized material as a sample, and the X-ray diffraction intensity of the sample is determined by “Rigaku RINT 2500VC X” manufactured by Rigaku Corporation. -RAY diffractometer "(trade name) was measured under the following conditions and calculated based on the formula (1).
The measurement conditions were X-ray source: Cu / Kα-radiation, tube voltage: 40 kV, tube current: 120 mA, measurement range: diffraction angle 2θ = 5 to 45 °. The measurement sample was prepared by compressing a pellet having an area of 320 mm ² × thickness of 1 mm. The X-ray scan speed was measured at 10 ° / min.

(2) Measurement of average degree of polymerization (copper-ammonia method)
((I) Preparation of measurement solution)
After adding 0.5 g of cuprous chloride and 20-30 mL of 25% aqueous ammonia to a volumetric flask (100 mL) and completely dissolving, add 1.0 g of cupric hydroxide and 25% aqueous ammonia, and add a volumetric flask. The amount up to one inch before the marked line. This was stirred for 30-40 minutes to completely dissolve. Thereafter, precisely weighed pulp (dried under reduced pressure at 105 ° C. and 20 kPa for 12 hours) was added, and the ammonia water was filled up to the marked line of the volumetric flask. It sealed so that air might not enter, and it stirred with the magnetic stirrer for 12 hours, and melt | dissolved. Similarly, measurement solutions with different concentrations were prepared by changing the amount of pulp to be added in the range of 20 to 500 mg.
((Ii) Measurement of viscosity average degree of polymerization)
Put the measurement solution (copper ammonia aqueous solution) obtained in (i) above into an Ubbelohde viscometer and let it stand in a constant temperature bath (20 people 0.1 ° C) for 1 hour, then measure the flow rate of the liquid. did. From the flow time (t (seconds)) of the copper ammonia solution having various pulp concentrations (g / dL) and the flow time (t ₀ (seconds)) of the copper ammonia aqueous solution without addition of the pulp, The reduced viscosity (η _sp / c) was determined from the following formula.
η _sp / c = (t / t ₀ −1) / c
(Where c is the pulp concentration (g / dL))
Further, the reduced viscosity was extrapolated to c = 0 to determine the intrinsic viscosity [η] (dL / g), and the viscosity average degree of polymerization (DP _v ) was determined from the following equation.
DP _v = 2000 × [η]
(In the formula, 2000 is a coefficient specific to cellulose.)

(3) Measurement of moisture content The moisture content in the pulp was measured at 150 ° C using a halogen moisture meter (trade name: “HG53” manufactured by METTLER TOLEDO Co., Ltd.). A 2 g sample was used, and the point at which the weight change rate for 50 seconds was 1 mg or less was taken as the end point of the measurement.
(4) Measurement of particle size of pulverized product The particle size was measured using a laser diffraction / scattering particle size distribution measuring device (manufactured by Horiba, Ltd., trade name: “LA-950V2”). The measurement conditions were ultrasonic treatment for 1 minute before particle size measurement, water was used as a dispersion medium during measurement, and the volume-based median diameter was measured at a temperature of 25 ° C. The refractive index used is 1.6.

(5) Measurement of degree of substitution of carboxymethylcellulose A carboxymethylcellulose sample was subjected to wet decomposition with sulfuric acid-hydrogen peroxide using a microwave wet ashing apparatus (product name: “A-300” manufactured by PROLABO), and then atomized. The Na content (%) was measured by atomic absorption method using a light absorption device (manufactured by Hitachi, Ltd., trade name: “Z-6100 type”), and the degree of substitution was calculated by the following formula (2).
Degree of substitution (DS) = (162 × Na content (%)) / (2300−80 × Na content (%)) (2)
The degree of substitution means the average number of carboxymethyl groups per anhydroglucose unit constituting the cellulose skeleton of carboxymethylcellulose.

(6) Measurement of aqueous solution viscosity A 1% aqueous solution of carboxymethyl cellulose (100 mol% neutralized with sodium salt) was prepared, and a B-type viscometer (manufactured by Toki Sangyo Co., Ltd., trade name: “TVB-10M”) was used. 25 ° C., rotor: No. 3 (for measurement of 200 to 2000 mPa · s), 30 rpm, and 3 minutes. In addition, No. When the viscosity is less than 200 mPa · s when measured in No. 3, rotor: No. 1 and exceeding 2000 mPa · s, rotor: No. 4 is used.

Production Example 1
(Manufacture of chip-like pulp)
A commercially available cotton linter pulp sheet (manufactured by Shandong Takamitsu Chemical Co., Ltd., trade name: “PCS2400”, crystallinity 94%, water content 7.5% by weight) is used as a sheet pelletizer (manufactured by Horai Co., Ltd., trade name: “SGG- 220-3X3 ") to form 3 mm square chips (average number of 100 pieces of long diameter (longest length of one chip)), and chip-like pulp (crystallinity 94%, average polymerization degree 2358, A water content of 7.3% by weight) was obtained.
Production Example 2
(Manufacture of chip-like pulp)
A commercially available wood pulp sheet (manufactured by Tenbeck, trade name: “Biofloc HV +”, crystallinity 74%, water content 6.7% by weight) is a sheet pelletizer (manufactured by Horai Co., Ltd., trade name: “SGG-220-3X3”). )) To form chips of 3 mm square (average number of 100 pieces of long diameter (the longest length of one piece)), and chip-like pulp (crystallinity 74%, average polymerization degree 1506, water content 6) 0.7% by weight).

Example 1
In a mortar, 100.0 g of pulp chips obtained in Production Example 1 as a dry weight (0.617Mol, anhydroglucose unit conversion) were charged, to which 30% sodium monochloroacetate (ClCH _₂ CO ₂ Na, hereinafter "SMCA Also, 167.8 g (0.432 mol) of an aqueous solution was added and mixed with stirring. After the mixture was dried at 60 ° C. under a nitrogen stream under reduced pressure conditions (about 70 kPa) for 12 hours, 20.0 g of ion-exchanged water was added and mixed to adjust the water content. It is put into a pot of a vibrating rod mill (Chuo Kako Co., Ltd., trade name: “MB-1”) with 13 circular rods having a cross section of 30 mm in diameter, with a vibration frequency of 1200 cpm, an amplitude of 8 mm, and a grinding time of 9 minutes. The mixture was pulverized under the conditions. Further, 48.6% (0.475 mol) of a 49.2% aqueous sodium hydroxide solution was added and mixed and ground for 9 minutes. The particle size of the obtained pulverized product was 125 μm, and the temperature of the pulverized product was about 35 ° C.
The mixed pulverized product obtained above was charged into a 1 L kneader (trade name: “PNV-1 type” manufactured by Irie Shokai Co., Ltd.), the inside of the kneader was decompressed (about 50 kPa), and then returned to normal pressure with nitrogen. Performed 3 times and replaced with nitrogen. Then, it heated up at 60 degreeC and stirred for 3 hours. The total amount of water derived from cellulose and other raw materials was 40 parts by weight with respect to 100 parts by weight of the dry raw material pulp.
After confirming that 98% by weight or more of the added SMCA had been consumed, the product was cooled to room temperature and the product was removed from the kneader. Next, after the product was dispersed in 1000 mL of 70% aqueous methanol, 2.6 g of acetic acid was added to neutralize excess sodium hydroxide. Next, 3000 mL of 70% aqueous methanol solution was added and stirred to elute by-product salts, unreacted substances, and the like. The obtained slurry was filtered (trade name: “Qualitative filter paper No. 2” manufactured by Toyo Roshi Kaisha, Ltd.), and the filter cake was washed with 1000 mL of acetone and dried to obtain 117 g of carboxymethyl cellulose. The degree of substitution of the obtained carboxymethyl cellulose per anhydroglucose unit was 0.47, and the 1% aqueous solution viscosity (25 ° C.) was 1961 mPa · s. The results are shown in Table 1.

Example 2
Thirteen round rods with a diameter of 30 mm are placed in a pot of a vibrating rod mill (manufactured by Chuo Kako Co., Ltd., trade name: “MB-1”), and the chip-like pulp obtained in Production Example 1 is dried by weight. 100.0 g (0.617 mol, anhydroglucose unit conversion), ion-exchanged water 12.2 g, and SMCA powder 50.3 g (0.432 mol) were added under the conditions of a frequency of 1200 cpm, an amplitude of 8 mm, and a grinding time of 6 minutes. Mixed and pulverized. Further, 48.6 g (0.475 mol) of a 49.3% aqueous sodium hydroxide solution was added and mixed and ground for 6 minutes. The particle size of the obtained pulverized product was 189 μm, and the temperature of the pulverized product was about 35 ° C. The total amount of water derived from cellulose and other raw materials in the obtained pulverized product was 40 parts by weight with respect to 100 parts by weight of the dry raw material pulp.
Subsequent operations were performed in the same manner as in Example 1 to obtain carboxymethylcellulose. The degree of substitution per unit of anhydroglucose of the obtained carboxymethylcellulose was 0.46, and the 1% aqueous solution viscosity (25 ° C.) was 1120 mPa · s. The results are shown in Table 1.

Example 3
Carboxymethylcellulose was obtained in the same manner as in Example 2 except that the pulverization time after addition of the SMCA powder was 12 minutes and that pulverization was not performed after the addition of the aqueous sodium hydroxide solution. The degree of substitution per unit of anhydroglucose of the obtained carboxymethyl cellulose was 0.46, and the 1% aqueous solution viscosity (25 ° C.) was 539 mPa · s. The results are shown in Table 1.
Example 4
40 weights with respect to 100 parts by weight of dry raw material pulp, using the chip-like pulp obtained in Production Example 2 as the chip-like pulp, and the total amount of water derived from cellulose and other raw materials in the pulverized product after mixing and pulverization In order to obtain parts, carboxymethylcellulose was obtained in the same manner as in Example 2 except that the amount of ion-exchanged water added before mixing and grinding was changed to 13.2 g. The degree of substitution of the obtained carboxymethylcellulose per anhydroglucose unit was 0.50, and the 1% aqueous solution viscosity (25 ° C.) was 801 mPa · s. The results are shown in Table 1.
Example 5
12.1 g of ion-exchanged water, 107.8 g (0.926 mol) of SMCA powder, 39.4 g (0.486 mol) of 49.3% sodium hydroxide aqueous solution as an alkali agent, and beaded sodium hydroxide (Tosoh Corporation) Carboxymethylcellulose was obtained in the same manner as in Example 2 except that 21.4 g (0.535 mol) manufactured by the company and trade name “Tosoh Pearl” was used. The degree of substitution of the obtained carboxymethyl cellulose per anhydroglucose unit was 0.79, and the viscosity of a 1% aqueous solution (25 ° C.) was 750 mPa · s. The results are shown in Table 1.

Example 6
Thirteen round rods with a diameter of 30 mm are placed in a pot of a vibrating rod mill (manufactured by Chuo Kako Co., Ltd., trade name: “MB-1”), and the chip-like pulp obtained in Production Example 1 is dried by weight. 100.0 g (0.617 mol, converted to anhydroglucose unit) and 49.3% sodium hydroxide aqueous solution 38.6 g (0.475 mol) were added and mixed under conditions of a vibration frequency of 1200 cpm, an amplitude of 8 mm, and a pulverization time of 6 minutes. Crushed. Further, 12.2 g of ion-exchanged water and 50.3 g (0.432 mol) of SMCA powder were added and mixed and ground for 6 minutes. The total amount of water derived from cellulose and other raw materials in the obtained pulverized product was 40 parts by weight with respect to 100 parts by weight of the dry raw material pulp.
Subsequent operations were performed in the same manner as in Example 1 to obtain carboxymethylcellulose. The degree of substitution of the obtained carboxymethyl cellulose per anhydroglucose unit was 0.55, and the 1% aqueous solution viscosity (25 ° C.) was 891 mPa · s. The results are shown in Table 1.

Comparative Example 1
Thirteen round rods with a diameter of 30 mm are placed in a pot of a vibrating rod mill (manufactured by Chuo Kako Co., Ltd., trade name: “MB-1”), and the chip-like pulp obtained in Production Example 1 is dried by weight. 100.0 g (0.617 mol, converted into anhydroglucose unit) was added, and the mixture was pulverized under conditions of a vibration frequency of 1200 cpm, an amplitude of 8 mm, and a pulverization time of 12 minutes, and powdered cellulose (crystallinity 78%, average polymerization degree 1216, The amount of water was 7.3% by weight and the particle size was 100 μm).
To 1 L kneader (manufactured by Irie Shokai Co., Ltd., trade name: “PNV-1 type”), the powdered cellulose obtained above, 12.2 g of ion-exchanged water, and 50.3 g (0.432 mol) of SMCA powder were added. For 1.5 hours. Thereto, 38.6 g (0.475 mol) of a 49.3% aqueous sodium hydroxide solution was added dropwise over 1 hour, and the mixture was further stirred for 30 minutes. The inside of the kneader was depressurized (about 50 kPa), and then the operation of returning to normal pressure with nitrogen was performed three times to perform nitrogen substitution. Then, it heated up at 60 degreeC and stirred for 3 hours. The total amount of water derived from cellulose and other raw materials was 40 parts by weight with respect to 100 parts by weight of dry powdered cellulose.
Subsequent operations were carried out in the same manner as in Example 1, such as neutralization and washing, to obtain carboxymethylcellulose. The degree of substitution of the obtained carboxymethylcellulose per anhydroglucose unit was 0.44, and the 1% aqueous solution viscosity (25 ° C.) was 343 mPa · s. The results are shown in Table 1.

The carboxymethyl cellulose of Comparative Example 1 obtained by adding monohaloacetic acid or a salt thereof and an alkali agent to the powdered cellulose obtained by pulverizing the raw material pulp and reacting it had a low aqueous solution viscosity. In contrast, the carboxymethyl cellulose of Examples 1 to 6 obtained by reacting a pulverized product obtained by adding monohaloacetic acid or a salt thereof and an alkaline agent before or during pulverization of the raw pulp was an aqueous solution. It has a high viscosity and is useful as a thickener.

The carboxymethyl cellulose having a high aqueous solution viscosity obtained by the method of the present invention is useful as a thickener for cosmetics and the like.

Claims

A process for producing carboxymethyl cellulose, wherein cellulose in a pulverized product obtained is pulverized by a pulverizer and then reacted with monohaloacetic acid or a salt thereof and an alkali agent at 40 to 100 ° C. Or the manufacturing method of carboxymethylcellulose which has the process of mixing the salt and / or alkali agent with this raw material pulp before the grinding | pulverization process of this raw material pulp, or during a grinding process.
2. The method for producing carboxymethyl cellulose according to claim 1, wherein an average degree of polymerization of cellulose constituting the raw pulp before pulverization is 1000 to 5000.
The method for producing carboxymethyl cellulose according to claim 1, comprising a step of mixing raw material pulp and monohaloacetic acid or a salt thereof and pulverizing the mixture.
The method for producing carboxymethyl cellulose according to any one of claims 1 to 3, wherein the raw pulp and monohaloacetic acid or a salt thereof are mixed and pulverized, and then an alkali agent is added and further pulverized.
The method for producing carboxymethyl cellulose according to any one of claims 1 to 4, further comprising a step of impregnating the raw pulp before pulverization with monohaloacetic acid or a salt thereof.
6. The molar equivalent ratio of monohaloacetic acid or a salt thereof (monohaloacetic acid or a salt thereof / anhydroglucose unit) to anhydroglucose unit of cellulose constituting the raw pulp is 0.3 to 3. Of producing carboxymethylcellulose.
The method for producing carboxymethyl cellulose according to any one of claims 1 to 6, wherein the pulverizer is a container-driven medium mill.
The carboxymethyl cellulose according to any one of claims 1 to 7, wherein when the ground product is reacted with monohaloacetic acid or a salt thereof and an alkali agent, the water content is 100 parts by weight or less with respect to 100 parts by weight of the dry raw material pulp. Production method.
The method for producing carboxymethyl cellulose according to any one of claims 1 to 8, wherein the monohaloacetic acid or a salt thereof is sodium monochloroacetate or potassium monochloroacetate.
The method for producing carboxymethyl cellulose according to any one of claims 1 to 9, wherein the alkali agent is an alkali metal hydroxide or an alkaline earth metal hydroxide.
The method for producing carboxymethyl cellulose according to any one of claims 1 to 8 and 10, wherein the molar equivalent ratio of the alkali agent to monohaloacetic acid (alkali agent / monohaloacetic acid) is 2 to 3.
The method for producing carboxymethyl cellulose according to any one of claims 1 to 10, wherein the molar equivalent ratio of the alkali agent to the monohaloacetate (alkali agent / monohaloacetate) is 1 to 2.
13. The method for producing carboxymethyl cellulose according to claim 1, wherein the viscosity (25 ° C.) of the obtained 1% by weight aqueous solution of carboxymethyl cellulose is 500 to 5000 mPa · s.