JP2009173869A - Method for producing hydroxyethyl cellulose - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a simple and efficient production method for a hydroxyethyl cellulose, simple and efficient also in industrial aspect. <P>SOLUTION: In this production method for the hydroxyethyl cellulose, a powder cellulose of low crystallinity is reacted with an ethylene oxide in the presence of a base catalyst of catalytic amount. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

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

  Hydroxyethyl cellulose is used as a blending composition for dispersants and stabilizers in paints, cosmetics, building materials, thickeners, adhesives, pharmaceuticals, etc., and as a starting material for other cellulose ether derivatives. Many manufacturing methods have been reported (see, for example, Patent Documents 1 and 2).

A general method for producing hydroxyethyl cellulose is not to directly react ethylene with ethylene oxide, which is an etherification agent, but to cellulose, a large amount of water and a large excess of alkali metal hydroxide such as sodium hydroxide are in a slurry state. The cellulose activation treatment called so-called arserization or mercerization is required. In this arserification process, operations such as filtration and squeezing are performed to remove excess alkali and water from the prepared alkali cellulose. However, even if this filtration or squeezing operation is performed, water of the same mass or more remains normally in the alkali cellulose. The alkali cellulose is considered to have an alcoholate in most of the hydroxyl groups in the cellulose molecule. In practice, the alkali cellulose is usually about 1 to 3 mol amount per glucose unit in the cellulose molecule, and at least 1 mol amount of alkali. Is contained.
Hydroxyethyl cellulose can be obtained by adding ethylene oxide to alkali cellulose activated by this arseration, but water of the same mass or more remaining after the arserating treatment described above also reacts with ethylene oxide (hydration). By-products such as ethylene glycol are produced in large quantities.
This reaction with ethylene oxide is also usually carried out in a slurry state. However, in order to carry out the reaction in the slurry state more efficiently, not only water but also various polar solvents may be added.
For example, Patent Documents 1 and 2 disclose a method of adding a polar solvent that is not easily compatible with water, such as tert-butanol or methyl isobutyl ketone, and separating and recovering the solvent from the aqueous phase after the reaction. Yes. However, unless the amount of alkali and the amount of water can be greatly reduced, it is substantially difficult to significantly reduce by-products such as ethylene glycol together with a large amount of neutralized salt.
Therefore, development of a simple and efficient method for producing hydroxyethyl cellulose with little waste, particularly development of an efficient production method by catalytic reaction, was an extremely useful problem from an industrial viewpoint.

JP-A-8-245701 Japanese Patent Laid-Open No. 6-199902

  An object of the present invention is to provide a process for producing hydroxyethyl cellulose that is industrially simple and efficient.

By using powdered cellulose having a reduced crystallinity, the present inventors do not require an activation treatment by arselation, and the reaction with ethylene oxide proceeds favorably and selectively with a catalytic amount of base. I found out.
That is, the present invention is a method for producing hydroxyethyl cellulose, in which low crystalline powdery cellulose is reacted with ethylene oxide in the presence of a catalytic amount of a base catalyst.

  ADVANTAGE OF THE INVENTION According to this invention, it is industrially simple and efficient, and can provide the manufacturing method of hydroxyethyl cellulose which has very few by-products, such as a neutralization salt.

[Preparation of low crystalline powdered cellulose]
In general, cellulose has several known crystal structures, and is defined as the crystallinity from the ratio of the amorphous part and the crystal part present in a part. The “crystallinity” in the present invention is natural. The degree of crystallinity of type I derived from the crystal structure of cellulose is shown, and is defined by the degree of crystallinity represented by the following formula (1) obtained from the powder X-ray crystal diffraction spectrum.

Crystallinity (%) = [(I _22.6 −I _18.5 ) / I _22.6 ] × 100 Formula (1)
[I _22.6 is the diffraction intensity of the lattice plane (002 plane) (diffraction angle 2θ = 22.6 °) in X-ray diffraction, and I _18.5 is the diffraction intensity of the amorphous portion (diffraction angle 2θ = 18.5 °). Show

The “low crystallinity” of the low crystalline powdery cellulose in the present invention indicates a state in which the ratio of the amorphous part is large in the crystal structure of the cellulose, and the crystallinity obtained from the above calculation formula (1) is 0%. Including the case of Preferably, the degree of crystallinity obtained from the above formula (1) is 50% or less and 0% or more.
Since generally known powdered cellulose also has a very small amount of amorphous part, the crystallinity thereof is generally in the range of 60 to 80% according to the above formula (1) used in the present invention. It is so-called crystalline cellulose contained, and its reactivity in cellulose ether synthesis such as hydroxyethyl cellulose synthesis in the present invention is extremely low.

  The low crystalline powdery cellulose used in the present invention can be prepared very easily from a sheet-like or roll-like pulp having a high cellulose purity obtained as a general-purpose raw material. The method for preparing the low-crystalline powdery cellulose is not particularly limited. For example, JP-A-62-236801, JP-A-2003-64184, JP-A-2004-331918, etc. Mention may be made of the preparation methods described.

Moreover, for example, the method of preparing by processing the chip-like pulp obtained by roughly pulverizing the sheet-like pulp with an extruder and further with a ball mill can also be mentioned.
As the extruder used in this method, a single-screw or twin-screw extruder can be used, and from the viewpoint of applying a strong compressive shear force, a so-called kneading disk portion is provided in any part of the screw. There may be. Although there is no restriction | limiting in particular as a processing method using an extruder, The method of throwing chip-like pulp into an extruder and processing continuously is preferable.
As the ball mill, a known vibration ball mill, medium stirring mill, rolling ball mill, planetary ball mill, or the like can be used. There is no restriction | limiting in particular in the material of the ball | bowl used as a medium, For example, iron, stainless steel, an alumina, a zirconia etc. are mentioned. The outer diameter of the ball is preferably 0.1 to 100 mm from the viewpoint of efficiently amorphizing the cellulose. As the medium, it is possible to use a rod-shaped or tube-shaped medium in addition to the ball.
Moreover, since the crystallinity degree of a cellulose can be reduced efficiently, as processing time of a ball mill, 5 minutes-72 hours are preferable. In this treatment, the treatment is preferably performed at a temperature of 250 ° C. or lower, preferably 5 to 200 ° C., in order to minimize the denaturation and deterioration due to the generated heat. Furthermore, it is preferable to perform the treatment under an inert gas atmosphere such as nitrogen as necessary.
If the method as described above is used, the molecular weight can be controlled. That is, although it is generally difficult to obtain powdered cellulose having a high degree of polymerization and low crystallinity, the degree of polymerization is preferably 100 to 2000, more preferably 100 to 1000. .

  The crystallinity of the low crystalline powdery cellulose used in the present invention is preferably 50% or less as the crystallinity obtained from the calculation formula (1). If this crystallinity is 50% or less, the addition reaction of ethylene oxide proceeds very well. In this respect, 40% or less is more preferable, and 30% or less is still more preferable. In particular, in the present invention, it is most preferable to use a so-called amorphous cellulose that is completely amorphous, that is, the degree of crystallinity obtained from the calculation formula (1) is almost 0%.

  The average particle size of the low crystalline powdered cellulose is not particularly limited as long as it can maintain a good fluidity as a powder, but is preferably 300 μm or less, more preferably 150 μm or less, and even more preferably 50 μm or less. . However, from the viewpoint of operability when carried out industrially, it is preferably 20 μm or more, more preferably 25 μm or more.

[Production of hydroxyethyl cellulose]
In the present invention, the low crystalline powdery cellulose obtained above can be reacted with ethylene oxide in the presence of a catalytic amount of a base catalyst to obtain hydroxyethyl cellulose.
In the present invention, the reaction with ethylene oxide proceeds catalytically, but since the reaction selectivity to cellulose is extremely high, the substitution degree as a hydroxyethyl group per glucose unit in the cellulose molecule is the reaction of ethylene oxide. Depending on the amount, the desired degree of substitution can be achieved. However, when hydroxyethyl cellulose is used as a starting material for the above-described dispersant or cellulose ether derivative, the preferred degree of substitution is from 0.01 to 3.0, and the more preferred degree of substitution is from 0.1 to 2.6.
The amount of ethylene oxide used in the present invention is preferably in the range of 0.001 to 20 mole times per glucose unit in the cellulose molecule, more preferably in the range of 0.005 to 10 mole times, particularly preferably 0.01. ˜5 mole times. When the amount of ethylene oxide used is within this range, the reaction efficiency of ethylene oxide with respect to cellulose is extremely high, so that hydroxyethyl cellulose having a desired substitution degree can be obtained.
If ethylene oxide is reacted 3 moles or more per glucose unit in the cellulose molecule, polyoxyethylene groups can be efficiently introduced onto the cellulose molecule.

  Examples of the base used as a catalyst in the present invention include alkali metal hydroxides such as sodium hydroxide, potassium hydroxide and lithium hydroxide, alkaline earth metal hydroxides such as magnesium hydroxide and calcium hydroxide, trimethylamine and triethylamine. And tertiary amines having low reactivity such as triethylenediamine. Of these, alkali metal hydroxides are preferred, and sodium hydroxide and potassium hydroxide are particularly preferred. These base catalysts can be used alone or in combination of two or more.

As a method for adding these base catalysts, particularly when the base is an alkali metal hydroxide, a high concentration aqueous solution is added, or after adding a dilute solution, the excess water amount is removed and the reaction is allowed to proceed. Is possible. Furthermore, it is also possible to add in a solid state using, for example, a ball mill as a mixer.
In the present invention, since the reaction proceeds catalytically, the amount of the base catalyst used is sufficient to use a catalytic amount with respect to cellulose or ethylene oxide. Specifically, glucose units in cellulose molecules are used. It is preferable to use an amount corresponding to 0.01 to 0.5 mol times, and more preferably to use an amount corresponding to 0.05 to 0.3 mol times.
The reaction state between cellulose and ethylene oxide in the present invention is not a slurry state with swelling, a high viscosity state, or an agglomerated state, and is maintained in a sufficiently dispersed state in a fluid powder state. Is preferred. From such a viewpoint, when the base is added with the dilute aqueous solution described above, the amount of water is preferably adjusted to 100% by mass or less based on cellulose.

The reaction with ethylene oxide in the present invention is preferably performed while maintaining the state in which the powder is dispersed as described above, but can also be performed in a dispersed state using a non-aqueous solvent as a dispersion medium other than water. is there. Among these, as non-aqueous polar solvents, secondary or tertiary lower alcohols such as isopropanol and tert-butanol which are generally used in the process of arseling, 1,4-dioxane, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, Examples thereof include ether solvents such as diglyme and triglyme such as diethylene glycol diethyl ether, diethylene glycol dibutyl ether and triethylene glycol dimethyl ether, and hydrophilic polar solvents such as dimethyl sulfoxide.
On the other hand, it is also possible to carry out the reaction in a dispersed state using a non-aqueous low polarity or non-polar solvent such as toluene, xylene, benzene, hexane, cyclohexane or other hydrocarbon oil.
When reacting in a dispersed state using these solvents, it is necessary to use an amount that can be well dispersed without causing aggregation in the solvent. However, if it is used in a large amount, a base such as an alkali that uses only a catalytic amount is diluted more than necessary, so that the reaction rate is remarkably reduced. Accordingly, the amount of these non-aqueous solvents used is desirably 20 times by mass or less, more preferably 10 times by mass or less, relative to the powdered cellulose.

  In the present invention, low-crystalline powdery cellulose and a base catalyst are dispersed in a reaction vessel capable of reacting with ethylene oxide such as an autoclave using the solvent described above, and the inside of the reaction vessel is sufficiently filled with an inert gas such as nitrogen. After the substitution, the reaction can be carried out by adding a predetermined amount of ethylene oxide and reacting. As a reaction vessel, a pressure gauge or the like is connected to a kneader-type mixer used for kneading resins as described in JP-A-2002-114801, and further, the airtightness, pressure resistance of the kneader-type mixer By using a kneader-type reactor that can improve the performance and perform the reaction under pressure, it is not always necessary to use a solvent, and cellulose can be mixed and reacted with ethylene oxide in a uniform and fluid powder state. ,preferable.

The kneader-type reactor is not particularly limited as long as stirring can be sufficiently performed. For example, the kneader-type reactor is described in Chemical Engineering Association edited by "Chemical Engineering Handbook" revised edition (published by Maruzen Co., Ltd.), pages 917 to 919. As described above, 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.
In the production method of the present invention, the reaction proceeds in a powder state. However, in the powder state, the fluidity is poorer than that in the slurry state. May exist. In order to improve this point, by changing the angle formed by the reaction vessel drive shaft and the horizontal of the kneader-type reactor, the contents adhering to the inner wall surface of the reaction vessel are dropped, and the contents are reduced. It is desirable to be stirred. Preferable examples of such a variable angle kneader type reactor include a variable angle ribbon mixer, a kneader, a single screw kneader, and a double-arm kneader. Specific examples of the variable angle ribbon mixer type reaction apparatus are shown in FIGS. 1 and 2, but the apparatus used for the reaction in the present invention is not limited to the apparatus shown in FIGS.
In the case of carrying out a reaction in a powder state using a double-arm kneader type reactor, it is preferable to use a ribbon-type, paddle-type, or blade-type stirring blade. The kneader type reactor may be a batch type or a continuous type.

The reaction temperature in the present invention is preferably in the range of 0 to 100 ° C, more preferably in the range of 10 to 80 ° C. Further, the reaction pressure is not particularly limited, but it is desirable that the reaction is performed in a pressure range of 0.001 to 1.0 MPa depending on the amount of ethylene oxide used, but if necessary, an inert gas such as nitrogen. It is also possible to carry out under a slight pressure while circulating the mixed gas diluted in step by step.
In the present invention, after completion of the reaction, after removing unreacted ethylene oxide, the base catalyst is neutralized with an acid, and if necessary, washed with hydrous isopropanol, hydrous acetone solvent or the like. By drying, hydroxyethyl cellulose can be obtained.

In addition, since the selectivity of the reaction from ethylene oxide is very good, the present invention reacts with a cationizing agent such as glycidyltrimethylammonium chloride as it is without performing an operation of removing the base catalyst as a neutralized salt after completion of the reaction. Further derivatization is possible, such as synthesis of cationized hydroxyethyl cellulose.
That is, if the present invention is used, various cellulose ether derivatives starting from hydroxyethyl cellulose can be synthesized from cellulose in one pot.

  In the present invention, the produced hydroxyethyl group may be bonded to a hydroxyl group at any position in the glucose unit in the cellulose molecule, but it can be adjusted to a desired substitution degree per glucose unit. Therefore, hydroxyethyl cellulose is widely used as a blending component for dispersants, stabilizers, etc. in paints, cosmetics, building materials, thickeners, adhesives, pharmaceuticals, etc., and as a starting material for other cellulose ether derivatives. Can do.

(1) Water content with respect to cellulose The water content with respect to cellulose was measured at 150 ° C. using an infrared moisture meter “FD-610” manufactured by Kett Scientific Laboratory.
In order to confirm the optimal moisture content of cellulose in the present invention in performing the reaction with ethylene oxide in the present invention, after adding a predetermined amount of water to the amorphous cellulose obtained in Production Example 1 described later, The agglomerated state was repeatedly observed visually by stirring and shaking.
As a result, although the produced low crystalline powdery cellulose contains at least 5% by mass of water, in order to react the cellulose in a fluid powder state, the water content is set to 100% by mass or less. Therefore, it was determined that the content was more preferably 80% by mass or less, most preferably 50% by mass or less, and even more preferably 30% by mass or less.

(2) Calculation of crystallinity The crystallinity of cellulose is calculated according to the above formula from the peak intensity of the diffraction spectrum measured under the following conditions using “Rigaku RINT 2500VC X-RAY diffractometer” manufactured by Rigaku Corporation. It was.
X-ray source: Cu / Kα-radiation, tube voltage: 40 kv, tube current: 120 mA, measurement range: 2θ = 5-45 °, measurement sample: produced by compressing pellets with an area of 320 mm ² × thickness of 1 mm,
X-ray scanning speed: 10 ° / min

(3) Measurement of degree of polymerization of powdered cellulose The degree of polymerization of powdered cellulose was measured by the copper ammonia method described in ISO-4312 method.
(4) Calculation of degree of substitution The degree of substitution as a hydroxyethyl group indicates the average number of moles of hydroxyethyl group introduced per glucose unit in cellulose, and is described in Macromol. Biosci., 5, 58 (2005). Using the method, the product was acetylated and confirmed from its various NMR (apparatus; Varian, Unity Inova 300) spectra.
(5) Measurement of average particle diameter of powdered cellulose The average particle diameter of powdered cellulose was measured using a laser diffraction / scattering particle size distribution measuring apparatus “LA-920” manufactured by Horiba, Ltd. The refractive index used is 1.2.

Production Example 1 (Production of Amorphized Powdered Cellulose)
A wood pulp sheet (Bolleguard's pulp sheet, crystallinity 74%) was shredded (manufactured by Meiko Shokai Co., Ltd., “MSX2000-IVP440F”) into a chip shape.
Next, the obtained chip-like pulp was charged at 2 kg / hr into a twin-screw extruder ("EA-20" manufactured by Suehiro EPM Co., Ltd.) equipped with a kneading disk at the center of the screw, and a shear rate of 660 sec. ^-1 and powdered by one pass treatment with cooling water flowing from outside under the condition of screw rotation speed of 300 rpm.
Next, the powdered cellulose thus obtained was charged into a batch-type medium agitating ball mill (“Attritor” manufactured by Mitsui Mining Co., Ltd .: container volume 800 mL, 6 mmφ steel ball 1400 g filled, stirring blade diameter 65 mm) in the powdery cellulose 100 g Was introduced. While passing cooling water through the container jacket, pulverization was performed at a stirring rotational speed of 600 rpm for 3 hours to obtain powdered cellulose (crystallinity 0%, polymerization 600, average particle size 40 μm). For the reaction of the powdered cellulose, an unsieved product (90% of the input amount) with a sieve having an opening of 32 μm was used.
In addition, the powder cellulose from which each crystallinity differs was prepared by changing the processing time in a ball mill process.

Example 1
In a reactor equipped with a measuring tank for ethylene oxide (1.5 L autoclave manufactured by Nitto High Pressure Co., Ltd.), 50 g and 20 of amorphous cellulose (crystallinity 0%, polymerization degree 600) obtained in Production Example 1 above. 10 g of a mass% aqueous sodium hydroxide solution (NaOH amount 0.06 mol) was added, 450 g (510 ml) of diethylene glycol dibutyl ether was added as a dispersion solvent, the inside of the reaction vessel was replaced with nitrogen, and the mixture was stirred as it was for 1 hour. Next, 50 g (1.14 mol) of ethylene oxide was charged, and the temperature was raised to 70 ° C. while stirring. The inside of the container initially showed 0.17 MPa. When stirred for 12 hours at 70 ° C., the pressure in the container decreased to 0.10 MPa. Thereafter, unreacted ethylene oxide was removed from the system, and the product was taken out from the reaction vessel. After neutralizing with acetic acid, it was washed with water-containing isopropanol (water content 15% by mass) and acetone, and dried under reduced pressure to obtain hydroxyethyl cellulose as 75 g of a white solid. The degree of substitution as a hydroxyethyl group was 2.0 per glucose unit in the cellulose molecule, and the reaction selectivity of ethylene oxide to cellulose was 96%.

Example 2
The reaction was carried out in the same manner as in Example 1 except that the stirring was continued until the pressure in the vessel became 0.01 MPa or less, but it took 24 hours as the reaction time, but ethylene oxide was completely consumed, Hydroxyethyl cellulose was obtained as a white solid of 98 g (theoretical amount: 100 g). The degree of substitution as a hydroxyethyl group was 3.8 per glucose unit, and the reaction selectivity of ethylene oxide to cellulose was 96%.

Example 3
The reaction was conducted in the same manner as in Example 1 except that 450 g of a mixed solvent of tert-butanol / water (mixing ratio 9: 1) was used as a dispersion solvent. As a result, hydroxyethyl cellulose was obtained as 73 g of a white solid. The degree of substitution as a hydroxyethyl group was 1.9 per glucose unit, and the reaction selectivity of ethylene oxide to cellulose was 78%.

Example 4
In the 1.5 L autoclave described in Example 1, 150 g of the non-crystalline cellulose (crystallinity 0%, polymerization degree 600) obtained in Production Example 1 and 7.4 g of powdered sodium hydroxide were added and reacted with nitrogen. After replacing the inside of the container, the temperature was raised to 70 ° C. with stirring. Next, 100 g of ethylene oxide was injected into the container over 4 hours while maintaining the pressure in the container at 0.10 MPa. When the mixture was stirred as it was at 70 ° C. for 1 hour, the pressure inside the container decreased to 0.06 MPa. Thereafter, unreacted ethylene oxide was removed from the system, and the product was taken out from the reaction vessel. After neutralizing with acetic acid, it was washed with water-containing isopropanol (water content 15% by mass) and acetone, and dried under reduced pressure to obtain 209 g of a yellowish white solid. The degree of substitution as a hydroxyethyl group was 1.5 per glucose unit in the cellulose molecule, and the reaction selectivity of ethylene oxide to cellulose was 75%.

Example 5
In an angle variable ribbon mixer type reactor having a pressure resistance of 1.1 L shown in FIG. 2, 100 g of amorphous cellulose (crystallinity 0%, polymerization degree 600) obtained in Production Example 1 and powder After adding 5.0 g of sodium hydroxide and replacing the inside of the reaction vessel with nitrogen, the temperature was raised to 50 ° C. with stirring. Next, 71 g of ethylene oxide was injected into the container over 4 hours while maintaining the pressure in the container at 0.10 MPa. Thereafter, the mixture was stirred and aged at 50 ° C. for 1 hour. From the start of charging to the end of aging, once every 30 minutes, the angle formed between the drive axis of the reaction vessel (line (a) in FIG. 2) and the horizontal is 45 ° → 0 ° → −45 ° → 0 ° → 45 °. And changed. Thereafter, unreacted ethylene oxide was removed from the system, and the product was taken out from the reaction vessel. After neutralizing with acetic acid, it was washed with water-containing isopropanol (water content 15% by mass) and acetone, and dried under reduced pressure to obtain hydroxyethyl cellulose as 170 g of a white solid. The degree of substitution as a hydroxyethyl group was 2.6 per glucose unit in the cellulose molecule, and the reaction selectivity of ethylene oxide to cellulose was 95%.

Comparative Example 1
In a 1 L flask, 50 g of highly crystalline powdered cellulose (Nippon Paper Chemical Co., Ltd. cellulose powder KC Flock W-400G; crystallinity 74%, polymerization degree 500) was placed, and a 20% by mass sodium hydroxide aqueous solution in a nitrogen atmosphere. 1000 ml was added and immersed for 1 day. Furthermore, after stirring for 5 hours with a stirrer at room temperature, an excess aqueous sodium hydroxide solution was removed by filtration and squeezed to obtain about 100 g of alkali cellulose. The obtained alkali cellulose contained 18 g (0.45 mol) of alkali as the amount of NaOH.
The total amount of the obtained alkali cellulose was transferred to the autoclave used in Example 3, and tert-butanol and water were further added. The same solvent ratio as in Example 3 (tert-butanol-water mixture ratio = 9: 1, total mass) To 450 g). Thereafter, 50 g (1.14 mol) of ethylene oxide was charged, and the temperature was raised to 70 ° C. while stirring. When the reaction was carried out at 70 ° C. for 12 hours, all the ethylene oxide was consumed. Thereafter, the product was taken out from the reaction vessel, neutralized with acetic acid, washed with water-containing isopropanol (water content 15% by mass) and acetone, and dried under reduced pressure to obtain hydroxyethyl cellulose as 68 g of a light brown white solid. The substitution degree as a hydroxyethyl group was 1.45 per glucose unit, the reaction selectivity of ethylene oxide to cellulose was 39%, and the reaction selectivity was extremely low as compared with Examples 1-5.

It is the schematic which shows the whole kneader-type reaction apparatus, (a) is a front view, (b) is a right view. 6 is a schematic view of a reaction vessel portion of a ribbon mixer type reactor used in Example 5. FIG. Although FIG. 2 shows a batch-type reaction apparatus, it can be a continuous type in which the reaction product is extracted from the extraction port 8.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1; Reaction container 2; Reaction container support part 3; Reaction container angle control part 4; Stirring blade 5; Stirring blade drive shaft 6; Raw material charging port 7; Ethylene oxide charging port 8; Ethylene oxide extraction port 9; 10; Heat medium outlet 11; Motor

Claims (6)

  A process for producing hydroxyethyl cellulose, comprising reacting low crystalline powdered cellulose with ethylene oxide in the presence of a catalytic amount of a base catalyst.   The method for producing hydroxyethyl cellulose according to claim 1, wherein the crystallinity of the low crystalline powdery cellulose is 50% or less.   The manufacturing method of the hydroxyethyl cellulose of Claim 1 or 2 whose water content with respect to low crystalline powdery cellulose is 100 mass% or less.   The manufacturing method of the hydroxyethyl cellulose in any one of Claims 1-3 using the nonaqueous solvent 20 mass times or less with respect to low crystalline powdered cellulose.   The manufacturing method of the hydroxyethyl cellulose in any one of Claims 1-4 which uses an alkali metal hydroxide as a base.   The method for producing hydroxyethyl cellulose according to any one of claims 1 to 5, wherein a kneader-type reactor is used.

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