JPS6296501A - Production of alkali metal salt of carboxymethylcellulose - Google Patents

Abstract

PURPOSE:To obtain CMC of a uniform distribution of degrees of substitution, easily and in good efficiency, by using a water-containing organic solvent solution in which part of the chloroacetic acid used is dissolved in the form of an alkali metal salt as an etherifying agent for etherifying an alkali cellulose. CONSTITUTION:Cellulose is reacted with an alkali hydroxide in a water- containing organic solvent (e.g., mixed solvent comprising ethanol and water) to produce an alkali cellulose. This alkali cellulose is etherified by using a water-containing organic solvent solution in which 20-60mol% of the chloroacetic acid used is dissolved in the form of an alkali metal chloroacetate as an etherifying agent to obtain an alkali metal salt of carboxycellulose. In this way, heat generation accompanied by neutralization in etherification can be controlled more easily than when chloroacetic acid is used alone and besides local destruction of an alkali cellulose can be suppressed.

Description

[Detailed description of the invention] Method for producing lithium salt.

3. The method for producing a carboxymethylcellulose alkali according to claim 111'i, wherein the organic solvent:water is a water-containing organic solvent with a weight ratio of 70:30 to 90:10.

Detailed Description of 3 Komei [Industrial Application Field] The present invention relates to a method for producing carboxymethyl cellulose ether alkali salt (hereinafter referred to as CHC).

[Prior art] CHC is made by etherifying cellulosic raw materials such as linter pulp and wood bulbs with alkali hydroxide and chloroacetic acid, and then performing post-processing such as t5) L'+" manufactured by T^. It is an anionic water-based polymer compound that can be obtained.

The industrial method for producing CHC is to prepare alkali cellulose and etherify it with chloroacetic acid as an etherification agent, but this involves a neutralization reaction of chloroacetic acid and a reaction between alkali chloroacetate and alkali cellulose. There is.

At that time, the amount of heat generated during neutralization of chloroacetic acid was 16.
9 kca 11 mol (actual value) and acetic acid 13,6 kca
l is large compared to 1 mole, and when CHC is produced by adding chloroacetic acid to alkali cellulose, the temperature of the system rises due to the heat of neutralization, and if it locally reaches the etherification temperature, Since the etherification reaction proceeds before the etherification agent is uniformly dispersed, resulting in non-uniform substitution, it is no exaggeration to say that the removal of the heat of neutralization influences the production of highly uniform CHC.

Removal of this heat of neutralization becomes an industrially difficult problem when the reaction scale is large and the amount of solvent is at a low magnification.

In addition, the solvent method has recently become mainstream because it has a wide production range in terms of degree of substitution, viscosity, purity, etc., and there are fewer side reactions, and various patent applications have been filed regarding the production of CHC using this method. For example, Japanese Patent Publications No. 32-2496, 32-7349, 44-560, 53-29357, and 1982-45201 are cited.

In Japanese Patent Publication No. 32-2496, sodium chloroacetate is used as the etherification agent, so there is no need to remove the heat of neutralization, but if sodium chloroacetate is used in the form of crystals (powder), However, it is difficult to uniformly dissolve the etherifying agent, and in addition, the rate of dissolution of the etherifying agent is slow in a conventional solvent composition, resulting in a long mixing reaction time. To solve this problem, it is possible to use sodium acetate as a solution, but there are no inexpensive and suitable solvents other than water.

Furthermore, when water is used, the water content in the reaction system increases, which reduces the effective utilization rate of the etherifying agent and reduces the transparency of the product, which is not preferable.

In Japanese Patent Publication No. 32-7349, chloroacetic acid is used as an etherification agent, but since it is difficult to remove the heat of neutralization, the temperature in the reaction system becomes high, and the etherification reaction occurs simultaneously with the neutralization reaction of chloroacetic acid. This is not preferable because the oxidation reaction also proceeds, resulting in a non-uniform CHC in which the alkali cellulose is partially destroyed.

In Japanese Patent Publication No. 44-560, after preparing high-quality alkali cellulose using a large excess of alkali, the large excess of alkali is neutralized with an acid before adding an etherification agent.
In this method, when a low magnification of a solvent is used, there is a lot of heat generated due to the neutralization of a large excess of alkali and chloroacetic acid, resulting in the destruction of alkali cellulose and the generation of water in the reaction system. Good CHC cannot be obtained due to changes in composition.

Japanese Patent Publication No. 53-29357 describes a method for arcelization and etherification by adding cellulose, a solvent 211 times or more larger than cellulose, sodium chloroacetate or a neutralized sodium chloroacetate, and sodium hydroxide. In this case, since the sodium chloroacetate is completely dissolved, the heat of neutralization reaction can be removed relatively easily, but since the use of solvent is significantly large, the energy cost for industrial solvent reuse is 1. - is large and the reaction vessel also needs to be relatively large, which is not preferable.

In JP-A No. 58-45201, all of the chloroacetic acid is neutralized in the reaction system, so the heat of neutralization is difficult to remove, and since etherification is carried out in a system with little alkali, CHC partially becomes an acid form. , its sodium salt takes a long time to prepare. Furthermore, if the preparation of the sodium salt of CMC is incomplete, the aqueous solution will gel, which is not preferable.

Japanese Patent Publication No. 40-3965 describes a method for directly cooling the inside of a system by utilizing adiabatic expansion of high-pressure gas.
Since the gas used is air or nitrogen gas, the cooling effect is poor, and the attached equipment is large, expensive, and complicated, which is undesirable.

Furthermore, in Japanese Patent Publication No. 59-52161, a mixed gas such as an inert gas such as nitrogen gas, water vapor, or organic solvent vapor in the system is forcedly circulated, a part of the gas components is liquefied using a fin cooler, etc. A method of directly cooling the system by recirculating it inside the system has been described, but the equipment is complicated and expensive, and since water vapor is present in the gas components, the cooling section is heated to 0°C. If it is less than that, the cooling effect will deteriorate significantly due to freezing, and in extreme cases, the fin portion may become blocked, which is not preferable.

[Problems to be Solved by the Invention] The present invention solves the above-mentioned problems in the production of CHC, and also makes it possible to easily obtain CHC with a uniform degree of substitution compared to conventional CHC. This was done in order to provide a manufacturing method with a high effective utilization rate of the curing agent.

[Means for solving the problem] The present invention is used in the production of CHC obtained by etherifying alkali cellulose obtained by reacting cellulose and alkali hydroxide in a water-containing organic solvent with an etherification agent. The present invention relates to a method for producing carboxymethyl cellulose ether alkali, characterized in that a water-containing organic solvent solution in which 20 to 60 mol% of chloroacetic acid is dissolved as an alkali salt of chloroacetic acid is used as an etherification agent.

[Example] In the present invention, alkali cellulose is obtained by reacting cellulose with alkali hydroxide in a water-containing organic solvent.

The cellulose is commonly used for the production of CHC.
For example, pulverized valves such as linter pulp and wood valves are used.

Examples of the alkali hydroxide include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, and among these, sodium hydroxide is particularly preferred for economical reasons.

The water-containing solvent used in the production of conventional CHC can be used to alcelize and etherify cellulose.

Specific examples include lower alcohols such as methanol, ethanol, propatool, 2-propatool, butyl alcohol, aromatic hydrocarbons such as benzene and toluene, ketones such as acetone and ethyl methyl ketone, and ethylene glycol dimethyl ether. A mixture of water and at least 1 fli of a loaded solvent selected from ethers such as Among these, lower alcohols containing three or more carbon atoms in the molecule, one selected from aromatic hydrocarbons, and a mixture of methanol and/or ethanol with water are preferred. In addition, the water-containing organic solvent phase or organic solvent/water has a mold mouth ratio of 70/3.
It is preferably 0 to 90/10. If the ratio of organic solvent/water in the water-containing loading solvent is less than 70/30, the effective utilization rate of the etherification agent will decrease significantly;
If the ratio exceeds /10, sufficient alkali cellulose cannot be prepared and the etherification reaction becomes non-uniform.

A solution of fatty acid alkali hydroxide dissolved in a water-containing organic solvent was added to cellulose with stirring, and the mixture was heated at 25 to 40°C for 20
It is preferable to add 33 to 5.5 times as much water-containing solvent and alkali hydroxide in an amount of 32 to 5.5 times as much as the alkali cellulose layer and alkali hydroxide in an amount of 32% or more based on the cellulose by arcelization for ~240 minutes.

25 in the alkali cellulose obtained as above.
CHC is obtained by adding an etherifying agent at ~30°C, evaporating the mixture, and etherifying the mixture.

The etherification agent is a mixture of chloroacetic acid and alkali salt of chloroacetic acid in the water-containing organic solvent. In this case, it is more preferable to use methanol or ethanol, which increases the solubility of the neutralized product of chloroacetic acid, as the water-containing loading solvent.

The chloroacetic acid is used in an amount of 0.6 to 5.0 mol, preferably 0.7 to 25 mol, per 1 mol of anhydroglucose of cellulose, depending on the desired degree of substitution.

The alkali salt of chloroacetic acid can be obtained by neutralizing the chloroacetic acid with, for example, sodium hydroxide, potassium hydroxide, etc. Among these, sodium hydroxide is preferable for reasons of safety.

The etherification agent is 20-6% of the chloroacetic acid used.
0 mol %, preferably 20 to 50 mol %, is neutralized with alkali hydroxide.

This is alkaline cellulose i! A certain amount of alkali is essential for II production, and when it is completely neutralized and alkali is secured to produce suitable alkali cellulose, there will be an excess of alkali during etherification, and conversely, it will be difficult to obtain suitable alkali cellulose. If the amount of alkali is set to 1, the alkaline field is insufficient to obtain good alkali cellulose.

When the temperature of the alkali chloroacetic acid salt is less than 20 mol%, it is almost as unfavorable as when chloroacetic acid M is used alone. This is considered to be because etherification progressed unevenly due to partial destruction of alkali cellulose upon addition of chloroacetic acid.

Furthermore, if the concentration of the alkali chloroacetate exceeds 60 mol %, crystals of sodium chloroacetate will precipitate, resulting in a slurry-like mixture, resulting in non-uniform mixing, which is also unfavorable in terms of properties.

The alkali salt of chloroacetic acid is more preferably a salt obtained by neutralizing chloroacetic acid with an alkali hydroxide in a solvent because it has extremely good solubility.

Further, it is necessary to use an etherifying agent in which the alkali salt of chloroacetic acid and chloroacetic acid do not precipitate at 30°C and are completely dissolved.

The etherification agent has a concentration of 40 to 7 as chloroacetic acid.
A substance containing 0% by weight, preferably 50 to 10% by weight is used. If the concentration as chloroacetic acid is less than 40% by weight, the temperature of the chemical in the system will decrease, and the effective utilization rate of the etherification agent will decrease, and if it exceeds 70%, the etherification agent will not be uniformly dispersed. Moreover, it is not preferable because the alkali cellulose is destroyed and it becomes difficult to uniformly etherify the cellulose.

In addition, the weight [F] ratio of the total amount of water-containing organic solvent to cellulose is 3.5.1 to 7.1 in order to obtain homogeneous CHC.
Prepare so that

: 1 of the above-mentioned water-containing organic medium and cellulose
If the ratio □ 1 is less than 35° 1, there will be insufficient solvent to dissolve the alkali necessary for alcelization, so either reduce the alkali ω or increase the water content in the hydrated solvent. There is a need.

When reducing the amount of alkali, sufficient alkaline:
If cellization cannot be performed or if the purpose is 1.
If the conversion rate is restricted and the water content in the water-containing organic solvent is increased, a suitable solvent composition cannot be maintained.
It is undesirable that the etherification becomes non-uniform and the effective utilization rate of the etherification agent decreases. In addition, if the solvent concentration is low, mechanical stirring becomes difficult and it becomes difficult to obtain homogeneous CHC, which is not preferable.

The CHC obtained by the method of the present invention as described above has a degree of substitution of 0.5 to 1.7, and the viscosity varies slightly depending on the degree of substitution, the degree of polymerization of the cellulose raw material, and the spring thinning operation. , anhydride 11%w3rf1, apparent viscosity is 10
000 milliPascals/second is possible.

Next, the present invention will be explained in more detail using Examples, but the present invention is not limited to these Examples.

Example 1 Sodium hydroxide 1.04 was added to 9.6 kQ of a water-containing organic solvent consisting of 871 ffi% of 2-propertool and 1311% of water.
kg was dissolved to obtain a sodium hydroxide solution for arcelization.

Next obtained sodium hydroxide solution for arcelization and pulverized linter pulp (average degree of polymerization 2400) 3 kg
The mixture was mixed in a kneader and further stirred at 25°C for 90 minutes to perform alcelization and obtain alkali cellulose.

Next, 1.35 kg of chloroacetic acid was added to 1.35 kg of a water-containing organic solvent consisting of 871% 2-propertool and 13% water.
kg, and then add 0.248 ko of 50% sodium hydroxide aqueous solution (neutralization rate 21.
6 mol%) was added dropwise and completely dissolved while keeping the liquid temperature below 30°C.
It was added to the alkali cellulose while keeping the temperature below C. (
Cooling was achieved with 7°C brine during the addition. ) Next, the temperature was raised to 70°C over about 20 minutes, and etherification was further performed at 70°C for 90 minutes. After the etherification was completed, it was neutralized with acetic acid and diluted with 751% methanol aqueous solution 8041.
After being purified twice, it was dried and ground to obtain CHC.

The physical properties of the obtained CHC, such as degree of substitution, viscosity, clarity of aqueous solution, glucose production, amount of free fiber pseudo and gelled material, were measured by the following methods.

The results are shown in Table 1.

+a+ Li substitution degree HC (anhydride) 1 (lI) was accurately weighed, placed in a porcelain crucible, incinerated at 560-600°C, and 0.IN sulfuric acid aqueous solution was added to the sodium oxide produced by iodization, Using phenolphthalein as an indicator, excess FiIM was
Back titrate with an aqueous IN potassium hydroxide solution and determine the degree of substitution from the following formula.

162X (B-A)f (degree of substitution) -□ 10.000-80x fB-A)f (where A is 0. Titration of IN potassium hydroxide aqueous solution f
fi (at'), f is the titer of 0.1N potassium hydroxide aqueous solution, and B is the titration ff1(d) of 0.1N potassium hydroxide aqueous solution in a blank test. )+b+viscosity CHC (anhydrous) 2.2g was accurately weighed and the inner diameter was 55IIl.
ffi, prepare and dissolve a 1% aqueous solution using pure water in a container with a depth of N51ffl, and rotate for 3 minutes at a rotation speed of 6 Orpm using an 88 type viscometer in a constant temperature water bath at 25 ± 0.2 ° C. Determine the viscosity of the viscosity.

+c+ Transparency of aqueous solution Transparency is the visibility of a 1% CHC aqueous solution under a constant light source, expressed in terms of the height of the liquid column. This method is a method commonly used in the art, and if the reaction is non-uniform, the transparency will decrease due to unreacted cellulose, undissolved parts, swollen gel bodies, etc., and the transparency value will become small. Therefore, the higher the uniformity of the reaction, the higher the solution transparency.

(d+glucose production C) Weigh out 0.5 g of Ic (anhydride), add about 50 g of water.
1d! After adding and dissolving, add vinegar 'Ili of pH 4.5.
Add 10 d of salt buffer solution and water to 100 In! ! What should I do? Add cellulase (Cellulase AP manufactured by Ohno Pharmaceutical) aqueous solution to this aqueous solution 4IR1 and add cellulase 5 ma/CHC1.
After adding the equivalent of 2.0 g of water and mixing thoroughly, the mixture was hydrolyzed at 40±0.2° C. for 72 hours. The produced glucose G was extracted by the Nelson-Somogyi method.

The unit is 1.00 anhydroglucose units of cellulose.
Indicated by 0. Glucose production m by enzymatic hydrolysis is said to be a measure of the substituent distribution of cellulose ethers, including CHC.

That is, it is said that this second cellulase is hydrolyzed and glucose is produced when there are three or more consecutive unconverted anhydroglucose units. (H, G, Reilick. Journal of Bolimar Science 8. Part A-16, p. 1705, p. 1965, (published in 1968) (H, G, 14 irick, J, Poly.

Sci,, PART A-1, 6, 1705, 1965
(1968)), the smaller the number of glucose molecules produced, the more uniform the substituent distribution.

(e) Accurately weigh 10 g of free fiber Satsuma CHC (anhydrous), dissolve it in water to a concentration of 10%, and dissolve the acetate! ! After adjusting the pH to 4.5 with liquid solution, add cellulase 5mg/CH to the aqueous solution of hillase.
After adding an amount equivalent to Cl Q and mixing well, the temperature was 40±0.
Hydrolyze for 72 hours at 2°C. The solution is filtered through a G-4 glass filter, thoroughly washed and dried, the glass filter is accurately weighed, and the free fiber content is determined by the following formula.

Free fiber N in CHC (tllU/100g
CHC) = (B-A)/Cx 100,000 (where A and B are 1 glass filter after filtration ((1
), C indicates CHC sample content (g). ) (Free fibers are unreacted cellulose parts, and the less hanging free fibers are, the better. Cellulase^P has so-called ``CHCase'' activity (activity to hydrolyze CHC) and ``Avicelase'' activity (highly crystalline cellulose). Cellulase has a high activity of hydrolyzing water-soluble cellulose derivatives such as CHC, but has a low activity of hydrolyzing water-soluble cellulose derivatives such as CHC), and under the above conditions, it is a cellulase that has a higher activity of hydrolyzing CHC than cellulose.) <h Amount of gelled material Take a 1% CMC aqueous solution into a centrifuge tube and spin at 15,000 rpm.
After centrifuging for 90 minutes, the gel part is taken out, dry weighed, and the f part area fraction relative to the dry matter is determined.

The lower this value is, the more uniformly the reaction progressed.

Aqueous solution transparency, glucose production M, free fiber M, and gelled product M are considered to be properties for evaluating the uniformity of the etherification reaction, and it is desirable that these four are in a well-balanced form.

Example 2 1.04 kg of sodium hydroxide was dissolved in 12 kQ of a water-containing organic solvent consisting of 60% by weight of ethanol, 25% by weight of benzene, and 15% by weight of water to obtain a sodium hydroxide solution for arcelization.

Next obtained sodium hydroxide solution for arcelization and pulverized linter pulp (average degree of polymerization 2400) 3k
A was mixed in a kneader and further stirred at 25° C. for 90 minutes to effect arcelization and obtain alkali cellulose.

Next, 1.35 k of a water-containing organic solvent consisting of 60 m% of ethanol, 25 weight Q% of benzene, and 1% of water (1.35 k of chlorovine vinegar was dissolved in 1.358 k of water, and then a portion of it was neutralized. to 50% sodium hydroxide aqueous solution 0.24
8 ka (neutralization rate 21.6 mol%) was added dropwise, and the liquid temperature was lowered to 3.
The etherification agent obtained by completely dissolving the agent at 0° C. or lower was added to the alkali cellulose while maintaining the system temperature at 30° C. or lower. (During the addition, the mixture was cooled with 7° C. brine.) Next, the temperature was raised to about 68° C. over about 20 minutes, and etherification was further carried out at this temperature for 90 minutes. After etherification, neutralize with acetic acid and add 80 Jl of 75% methanol aqueous solution.
After fa production three times, CHC was obtained by drying and pulverizing.

i The physical properties of the obtained CMC were measured in the same manner as in Example 1.

The results are shown in Table 1.

Example 3 2-proper tool used in Example 1 81% mold mouth, water 13
9. Water-containing organic solvent consisting of % by weight. 2 instead of ekg
- Propatool 841mm%, methanol 3x 1
%, water 13f1!1! 12 directions of a water-containing organic solvent consisting of I%,
・*13tt'fM%#=8 water-containing solution W 1.3
CHC was obtained in the same manner as in Example 1, except that 0.74 kg of a water-containing organic solvent consisting of 85 weight percent methanol and 15 weight percent water was used instead of 5 kQ.

The physical properties of the obtained CHC were measured in the same manner as in Example 1.

The results are shown in Table 1.

□ 1 Example 4 Ethanol 60% by weight, benzene 25711%, water 15%
A sodium hydroxide solution for arcelization was prepared by dissolving 1.56 kg of sodium hydroxide in a water-containing organic solvent 12 consisting of 18%.

Next, the obtained sodium hydroxide solution for arcelization and the crushed linter pulp (average degree of polymerization 2400) 3k (
+ were mixed in a kneader and further stirred at 25°C for 90 minutes to perform alcelization and obtain alkali cellulose.

Next, 2.2111 chloroacetic acid was dissolved in 1.50 kQ of a water-containing organic solvent consisting of 85% by weight of ethanol and 15% by weight of water, and in order to partially neutralize it, a 50% aqueous sodium hydroxide solution (o, e54ka) was dissolved. Neutralization rate 34.9 mol%)
was added dropwise, and the etherifying agent was completely dissolved while keeping the liquid temperature below 30°C. The resulting etherifying agent was added to the alkali cellulose while keeping the internal temperature below 30°C. (During the addition, the mixture was cooled with brine at 7°C.) Next, the temperature was raised to 68°C over about 20 minutes, and etherification was further carried out at 68°C for 90 minutes. After the etherification was completed, it was neutralized with acetic acid, purified three times with 80 η of a 75% methanol aqueous solution, dried and ground to obtain CHC.

The physical properties of the obtained CHC were measured in the same manner as in Example 1.

The results are shown in Table 1.

Example 5 2-Water-containing organic solvent consisting of 81 weight percent 2-propanol and 13 weight percent water 18. (1.6 sodium hydroxide per ikg)
5 kg was dissolved to obtain a sodium hydroxide solution for arcelization.

Next, the obtained sodium hydroxide solution for arcelization and the crushed linter valve (average [degree of polymerization 2400)] 3
The mixture was mixed in a kneader and further stirred at 25°C for 90 minutes to achieve 11 times alkelization, yielding alkali cellulose.

Next, 2-Propatool 84wt 1%, methanol 3wt 1%
]%, water-containing organic solvent 1.5k (J
After dissolving 2.211 kg of chloroacid in
50% aqueous sodium hydroxide solution to neutralize some
．． 474KO (neutralization rate 25.3 mol%) was added, and the liquid;
The etherification agent obtained by completely dissolving n at 30°C was added to the alkali cellulose while keeping the system temperature below 30'C. (During the addition, the mixture was cooled with 7°C brine.) Next, the temperature was raised to 70°C over about 20 minutes, and etherification was further carried out at 70°C for 90 minutes. After completion of etherification, neutralize with acetic acid to give 75rl! i1% methanol aqueous solution 801
After purification three times, CHC was obtained by drying and grinding.

The physical properties of the obtained CHC were measured in the same manner as in Example 1.

The results are shown in Table 1.

Example 6 Ethanol 60 weight 121%, benzene 25 weight %, water 1
A sodium hydroxide solution for arcelization was obtained by dissolving 1.69 kg of sodium hydroxide in 15 kg of a water-containing solvent consisting of 1% by weight.

Next, the sodium hydroxide solution for arcelization and the crushed lintal bulb (average degree of polymerization 2400) 3k
(1) were mixed in a kneader and further stirred at 25° C. for 90 minutes to perform alcelization to obtain alkali cellulose.

Next, 2632 kg of chloroacetic acid was dissolved in 2.63 kg of a water-containing organic solvent consisting of 85% by weight of ethanol and 15% by weight of water. 48.3 mol%) was added,
The completely dissolved etherification agent was added to the alkali cellulose while maintaining the system temperature at 30° C. or lower. (During the addition, the mixture was cooled with 7°C brine.) Next, the temperature was raised to 68°C over about 20 minutes, and etherification was further carried out at 68°C for 90 minutes. After the etherification was completed, it was neutralized with acetic acid and diluted with 75% methanol aqueous solution 80.0%.
After purification twice, it was dried and ground to obtain CHC.

The physical properties of the obtained CHC were measured in the same manner as in Example 1.

The results are shown in Table 1.

Actual tM Example 7 2-A hydrous organic solution consisting of 871% by weight of propatool and 13% by weight of water! Sodium hydroxide 1.04 to 112゜Okg
kg was dissolved to obtain a sodium hydroxide solution for arcelization.

Next obtained sodium hydroxide solution for arcelization and pulverized linter pulp (average degree of polymerization 2400) 3k
(I) was mixed in a kneader and further stirred at 25°C for 90 minutes to perform alcelization to obtain alkali cellulose.

Next, 1.35 k of chloroacetic acid was added to 1.35 k of a water-containing organic solvent consisting of 87@m% of 2-propanol and 13% by weight of water.
After dissolving 58 kg, 50 kg was added to partially neutralize it.
% sodium hydroxide aqueous solution 0.248k (] (neutralization rate 2
186 mol %) was added dropwise and completely dissolved while keeping the liquid temperature below 30'C, and the obtained etherifying agent was added to the alkali cellulose while keeping the internal temperature below 30'C. (During the addition, the mixture was cooled with brine at 7°C.) Next, the temperature was raised to 10°C over about 20 minutes, and etherification was further carried out at 70°C for 90 minutes. After the etherification was completed, it was neutralized with acetic acid, purified three times with a 15% methanol aqueous solution 80j, dried and pulverized to obtain CHC.

The physical properties of the obtained CHC were measured in the same manner as in Example 1.

The results are shown in Table 1.

Example Day 2 - 1.04 kg of sodium hydroxide in 12.0 kQ of a water-containing organic solvent consisting of 68% by weight of propatool and 32% by weight of water.
kg was dissolved to obtain a sodium hydroxide solution for arcelization.

Next obtained sodium hydroxide solution for arcelization and pulverized linter pulp (average degree of polymerization 2400) 3ka
The mixture was mixed in a kneader and further stirred at 25°C for 90 minutes to perform alcelization and obtain alkali cellulose.

Next, 1.35 k of a water-containing organic solvent consisting of 68% by weight of 2-propanol and 1% by weight of water (1.3% by weight of chloroacetic acid per liter) was added.
After dissolving 58kQ, add 50% to partially neutralize it.
Sodium hydroxide aqueous solution 0.248kG (neutralization rate 21
．． 6 mol%) was added dropwise and completely dissolved while keeping the liquid temperature below 30°C.
It was added to alkali cellulose while maintaining the following. (During the addition, the mixture was cooled with brine at 7°C.) Next, the temperature was raised to 70°C for about 20 minutes, and etherification was further carried out at 70°C for 90 minutes. After the etherification was completed, it was neutralized with acetic acid, purified three times with 75% by weight methanol aqueous solution 8ON, dried and pulverized to obtain CHC.

The physical properties of the obtained CHC were measured in the same manner as in Example 1.

The results are shown in Table 1.

Example 9 2-Water-containing organic solvent consisting of 92% by weight of propatool and 8% by weight of water 12. Sodium hydroxide 1.04 k in OkQ
g was dissolved to obtain a sodium hydroxide solution for arcelization.

Next, the obtained sodium hydroxide solution for arcelization and the crushed linter pulp (average degree of polymerization 2400) 3k (
J was mixed in a kneader and further stirred at 25° C. for 90 minutes to perform alcelization and obtain alkali cellulose.

□ Next, 2-proper tool 92% by weight, water 8% by weight□
After dissolving 1,358 kfJ of chloroacetic acid in 1.35 k (l) of a water-containing organic solvent, 0.248 kfJ of a 50% aqueous sodium hydroxide solution was added to partially neutralize the solution. 21
．． 6 mol %) was added dropwise and completely dissolved while keeping the liquid temperature below 30°C.
[1[10°C″′1″′″51. '5 f;E t
fi'z7)Ltj3')t:
Added to lulose. (During addition, 7℃ Bligh 1
Cooled in a tube. ) :: 1 Next, the temperature was raised to 70°C over about 20 minutes, and etherification was further carried out at 70:1°C for 90 minutes. Etherification
After completion, neutralize with acetic acid, 75% by weight methanol/water:1 solution 80! After preparing the product three times using J, it was dried and ground to obtain CHC.

The physical properties of the obtained CHC were measured in the same manner as in Example 1.

The results are shown in Table 1.

Comparative Example 1 2-propatool 87 @ suspension%, water-containing organic solvent 12.0k (] consisting of 13% water and 1% by weight) and 1.16% sodium hydroxide
4kQ was dissolved to obtain a sodium hydroxide solution for arcelization.

Next, the obtained sodium hydroxide solution for arcelization and the crushed linter bulb (average degree of polymerization 2400) 3
k! II was mixed in a kneader and further stirred at 25° C. for 90 minutes to effect arcelization, thereby obtaining alkali cellulose.

Next, 2-A combined organic solution consisting of 87% propatool and 13% water! Chloroacetic acid 1.3 in s1.35 ka
sakg was dissolved. The etherification agent obtained by completely dissolving the liquid temperature at 30'C or below is heated to 30'C or less.
It was added to alkali cellulose while keeping the temperature below 0°C.

(During the addition, the mixture was cooled with brine at 7°C.) Next, the temperature was raised to 70°C over about 20 minutes, and etherification was further carried out at 70°C for 90 minutes. After etherification, neutralize with acetic acid and add 75% methanol aqueous solution 80% by weight. 3 in J
After being purified twice, it was dried and ground to obtain CHC.

The physical properties of the obtained CHC were measured in the same manner as in Example 1.

The results are shown in Table 1.

Comparative Example 2 1.10 kg of sodium hydroxide was dissolved in 12.0 kl of a water-containing organic solvent consisting of 87% by weight of 2-propertool and 13ffl of water to obtain a sodium hydroxide solution for arcelization.

Next obtained sodium hydroxide solution for arcelization and pulverized linter pulp (average degree of polymerization 2400) 3kl
; I was mixed in a kneader and further stirred at 25° C. for 90 minutes to effect arcelization, thereby obtaining alkali cellulose.

Next, 1.35 k of a water-containing organic solvent consisting of 81 wt ω% of 2-propanol and 13 wt% of water (1.3 wt.
After dissolving Ω in 58, add 50 to partially neutralize it.
% sodium hydroxide aqueous solution 0.128ko (neutralization rate 1
11 mol%) was added dropwise, and the etherification agent was completely dissolved by keeping the liquid temperature below 30°C.
It was added to the alkali cellulose while keeping the temperature below C. (
The inside of the additive was cooled with 7°C brine. ) Next, the temperature was raised to 70°C in about 20 minutes, and then further raised to 70°C.
Etherification was carried out for 90 minutes. After etherification,
Neutralize with acetic acid and add 75% methanol aqueous solution 80% by weight. After purification with J for three times, it was dried and ground to obtain CHC.

The physical properties of the obtained CHC were measured in the same manner as in Example 1.

The results are shown in Table 1.

Comparative Example 3 A water-containing organic solvent consisting of 25% by weight of benzene, 60% by weight of ethanol, and 15% by weight of water 12. 1.14 kg of sodium hydroxide was dissolved in Okg to obtain a sodium hydroxide solution for arcelization.

Next, the obtained sodium hydroxide solution for arcelization and the crushed linter pulp (average degree of polymerization 2400) 3k (
I was mixed in a kneader and further stirred at 25°C for 90 minutes to effect arcelization and obtain alkali cellulose.

Next, 2.211 kg of chloroacetic acid was dissolved in 1.50 kg of a water-containing organic solvent consisting of 25% by weight of benzene, 60% by weight of ethanol, and 151m% of water, and then sodium hydroxide was added to partially neutralize the mixture. 0.747kg (neutralization rate 7
9.8 mol%) was added. When the solution was kept at a temperature of 30° C. or lower and allowed to stand, salt precipitated.

The obtained etherification agent was added to the arcelization reaction solution while maintaining the system internal temperature at 30° C. or lower. (During the addition, the mixture was cooled with brine at 7°C.) Next, the temperature was raised to 70°C over about 20 minutes, and etherification was further carried out at 70°C for 120 minutes. After etherification,
After neutralization with acetic acid and purification three times with 80 fJ of a 75% methanol aqueous solution, it was dried and pulverized to obtain CHC.

The physical properties of the obtained CHC were measured in the same manner as in Example 1.

1985 [12f Revised Application No. 146214 2 Name of the name Cal Small-1-dimethyl cellulose manufacturing method] Relationship with J3 correction person 1'1 1! Applicant's Address: 55 Nishishichijo Higashikubo-cho, Shimogyo-ku, Kyoto City Name:
(350) Daiichi Kogyo Seiyaku Co., Ltd. 5 Subject of amendment (1) Contents of amendment in section 6 for detailed explanation of sales in the specification (1) Statement of specification page 26, line 2, r 12. Okg. J wor3
0. Correct OklJ.

[Effects of the Invention] According to the method for producing CHC of the present invention, in particular, a solution in which chloroacetic acid containing 20 to 60 mol % of an alkali chloroacetic acid salt is completely dissolved in a water-containing organic solvent is used as an etherification agent. This makes it easier to suppress heat generation due to neutralization than when using chloroacetic acid alone, and also suppresses local destruction of alkali cellulose, making it easier to produce CHC with a uniform degree of substitution distribution. It has the effect of being able to be used.

Claims (1)

[Claims] 1. A chloromethane used in the production of a carboxymethylcellulose ether alkali salt obtained by etherifying an alkali cellulose obtained by reacting cellulose with an alkali hydroxide in a water-containing organic solvent with an etherification agent. A method for producing a carboxymethyl cellulose ether alkali salt, characterized in that a water-containing organic solvent solution in which 20 to 60 mol% of acetic acid is dissolved as an alkali chloroacetic acid salt is used as an etherification agent. 2 The weight ratio of water-containing organic solvent and cellulose is 3.5:1 ~
A method for producing a carboxymethylcellulose ether alkali salt according to claim 1, wherein the ratio is 7:1. 3. The method for producing a carboxymethyl cellulose alkali salt according to claim 1, wherein the organic solvent is a water-containing organic solvent with a weight ratio of 70:30 to 90:10.